import of libc++abi 6.0.0

26 files changed, 4041 insertions, 1750 deletions

diff --git a/lib/libcxxabi/src/CMakeLists.txt b/lib/libcxxabi/src/CMakeLists.txt
index b851b4ac777..240f6d0d103 100644
--- a/lib/libcxxabi/src/CMakeLists.txt
+++ b/lib/libcxxabi/src/CMakeLists.txt
@@ -1,22 +1,29 @@
 # Get sources
 set(LIBCXXABI_SOURCES
-  abort_message.cpp
+  # C++ABI files
   cxa_aux_runtime.cpp
   cxa_default_handlers.cpp
   cxa_demangle.cpp
   cxa_exception_storage.cpp
   cxa_guard.cpp
   cxa_handlers.cpp
-  cxa_new_delete.cpp
   cxa_unexpected.cpp
   cxa_vector.cpp
   cxa_virtual.cpp
-  exception.cpp
+  # C++ STL files
+  stdlib_exception.cpp
+  stdlib_stdexcept.cpp
+  stdlib_typeinfo.cpp
+  # Internal files
+  abort_message.cpp
+  fallback_malloc.cpp
   private_typeinfo.cpp
-  stdexcept.cpp
-  typeinfo.cpp
 )
 
+if (LIBCXXABI_ENABLE_NEW_DELETE_DEFINITIONS)
+  list(APPEND LIBCXXABI_SOURCES stdlib_new_delete.cpp)
+endif()
+
 if (LIBCXXABI_ENABLE_EXCEPTIONS)
   list(APPEND LIBCXXABI_SOURCES cxa_exception.cpp)
   list(APPEND LIBCXXABI_SOURCES cxa_personality.cpp)
@@ -24,7 +31,7 @@ else()
   list(APPEND LIBCXXABI_SOURCES cxa_noexception.cpp)
 endif()
 
-if (UNIX AND NOT (APPLE OR CYGWIN))
+if (LIBCXXABI_ENABLE_THREADS AND UNIX AND NOT (APPLE OR CYGWIN))
   list(APPEND LIBCXXABI_SOURCES cxa_thread_atexit.cpp)
 endif()
 
@@ -45,24 +52,32 @@ if (LIBCXXABI_HAS_CXA_THREAD_ATEXIT_IMPL)
   add_definitions(-DHAVE___CXA_THREAD_ATEXIT_IMPL)
 endif()
 
-# Generate library list
-set(libraries ${LIBCXXABI_CXX_ABI_LIBRARIES})
-
 if (LIBCXXABI_ENABLE_THREADS)
-  append_if(libraries LIBCXXABI_HAS_PTHREAD_LIB pthread)
+  add_library_flags_if(LIBCXXABI_HAS_PTHREAD_LIB pthread)
 endif()
 
-append_if(libraries LIBCXXABI_HAS_C_LIB c)
-
+add_library_flags_if(LIBCXXABI_HAS_C_LIB c)
 if (LIBCXXABI_USE_LLVM_UNWINDER)
-  list(APPEND libraries unwind)
+  # Prefer using the in-tree version of libunwind, either shared or static. If
+  # none are found fall back to using -lunwind.
+  # FIXME: Is it correct to prefer the static version of libunwind?
+  if (NOT LIBCXXABI_ENABLE_STATIC_UNWINDER AND (TARGET unwind_shared OR HAVE_LIBUNWIND))
+    list(APPEND LIBCXXABI_LIBRARIES unwind_shared)
+  elseif (LIBCXXABI_ENABLE_STATIC_UNWINDER AND (TARGET unwind_static OR HAVE_LIBUNWIND))
+    list(APPEND LIBCXXABI_LIBRARIES unwind_static)
+  else()
+    list(APPEND LIBCXXABI_LIBRARIES unwind)
+  endif()
 else()
-  append_if(libraries LIBCXXABI_HAS_GCC_S_LIB gcc_s)
+  add_library_flags_if(LIBCXXABI_HAS_GCC_S_LIB gcc_s)
+endif()
+if (MINGW)
+  # MINGW_LIBRARIES is defined in config-ix.cmake
+  list(APPEND LIBCXXABI_LIBRARIES ${MINGW_LIBRARIES})
 endif()
 
 # Setup flags.
-append_if(LIBCXXABI_COMPILE_FLAGS LIBCXXABI_HAS_FPIC_FLAG -fPIC)
-append_if(LIBCXXABI_LINK_FLAGS LIBCXXABI_HAS_NODEFAULTLIBS_FLAG -nodefaultlibs)
+add_link_flags_if_supported(-nodefaultlibs)
 
 set(LIBCXXABI_SHARED_LINK_FLAGS)
 
@@ -82,58 +97,108 @@ if ( APPLE )
   endif()
 endif()
 
-string(REPLACE ";" " " LIBCXXABI_COMPILE_FLAGS "${LIBCXXABI_COMPILE_FLAGS}")
-string(REPLACE ";" " " LIBCXXABI_LINK_FLAGS "${LIBCXXABI_LINK_FLAGS}")
-string(REPLACE ";" " " LIBCXXABI_SHARED_LINK_FLAGS "${LIBCXXABI_SHARED_LINK_FLAGS}")
+split_list(LIBCXXABI_COMPILE_FLAGS)
+split_list(LIBCXXABI_LINK_FLAGS)
+split_list(LIBCXXABI_SHARED_LINK_FLAGS)
+
+# FIXME: libc++abi.so will not link when modules are enabled because it depends
+# on symbols defined in libc++.so which has not yet been built.
+if (LLVM_ENABLE_MODULES)
+  string(REPLACE "-Wl,-z,defs" "" CMAKE_SHARED_LINKER_FLAGS "${CMAKE_SHARED_LINKER_FLAGS}")
+endif()
 
 # Add a object library that contains the compiled source files.
 add_library(cxxabi_objects OBJECT ${LIBCXXABI_SOURCES} ${LIBCXXABI_HEADERS})
-
 set_target_properties(cxxabi_objects
-  PROPERTIES
-    COMPILE_FLAGS "${LIBCXXABI_COMPILE_FLAGS}"
-  )
+                      PROPERTIES
+                        CXX_EXTENSIONS
+                          OFF
+                        CXX_STANDARD
+                          11
+                        CXX_STANDARD_REQUIRED
+                          ON
+                        COMPILE_FLAGS
+                          "${LIBCXXABI_COMPILE_FLAGS}"
+                        POSITION_INDEPENDENT_CODE
+                          ON)
 
 set(LIBCXXABI_TARGETS)
 
 # Build the shared library.
 if (LIBCXXABI_ENABLE_SHARED)
   add_library(cxxabi_shared SHARED $<TARGET_OBJECTS:cxxabi_objects>)
-  target_link_libraries(cxxabi_shared ${libraries})
+  target_link_libraries(cxxabi_shared ${LIBCXXABI_LIBRARIES})
   set_target_properties(cxxabi_shared
-    PROPERTIES
-      LINK_FLAGS    "${LIBCXXABI_LINK_FLAGS} ${LIBCXXABI_SHARED_LINK_FLAGS}"
-      OUTPUT_NAME   "c++abi"
-      VERSION       "1.0"
-      SOVERSION     "1"
-    )
+                        PROPERTIES
+                          CXX_EXTENSIONS
+                            OFF
+                          CXX_STANDARD
+                            11
+                          CXX_STANDARD_REQUIRED
+                            ON
+                          LINK_FLAGS
+                            "${LIBCXXABI_LINK_FLAGS} ${LIBCXXABI_SHARED_LINK_FLAGS}"
+                          OUTPUT_NAME
+                            "c++abi"
+                          POSITION_INDEPENDENT_CODE
+                            ON
+                          SOVERSION
+                            "1"
+                          VERSION
+                            "1.0")
   list(APPEND LIBCXXABI_TARGETS "cxxabi_shared")
 endif()
 
 # Build the static library.
 if (LIBCXXABI_ENABLE_STATIC)
-  add_library(cxxabi_static STATIC $<TARGET_OBJECTS:cxxabi_objects>)
-  target_link_libraries(cxxabi_static ${libraries})
+  set(cxxabi_static_sources $<TARGET_OBJECTS:cxxabi_objects>)
+  if (LIBCXXABI_USE_LLVM_UNWINDER AND LIBCXXABI_ENABLE_STATIC_UNWINDER)
+    if (TARGET unwind_static OR HAVE_LIBUNWIND)
+      list(APPEND cxxabi_static_sources $<TARGET_OBJECTS:unwind_objects>)
+    endif()
+  endif()
+  add_library(cxxabi_static STATIC ${cxxabi_static_sources})
+  target_link_libraries(cxxabi_static ${LIBCXXABI_LIBRARIES})
   set_target_properties(cxxabi_static
-    PROPERTIES
-      LINK_FLAGS    "${LIBCXXABI_LINK_FLAGS}"
-      OUTPUT_NAME   "c++abi"
-  )
+                        PROPERTIES
+                          CXX_EXTENSIONS
+                            OFF
+                          CXX_STANDARD
+                            11
+                          CXX_STANDARD_REQUIRED
+                            ON
+                          LINK_FLAGS
+                            "${LIBCXXABI_LINK_FLAGS}"
+                          OUTPUT_NAME
+                            "c++abi"
+                          POSITION_INDEPENDENT_CODE
+                            ON)
   list(APPEND LIBCXXABI_TARGETS "cxxabi_static")
 endif()
 
 # Add a meta-target for both libraries.
 add_custom_target(cxxabi DEPENDS ${LIBCXXABI_TARGETS})
 
-install(TARGETS ${LIBCXXABI_TARGETS}
-  LIBRARY DESTINATION lib${LIBCXXABI_LIBDIR_SUFFIX} COMPONENT libcxxabi
-  ARCHIVE DESTINATION lib${LIBCXXABI_LIBDIR_SUFFIX} COMPONENT libcxxabi
-  )
+if (LIBCXXABI_INSTALL_LIBRARY)
+  install(TARGETS ${LIBCXXABI_TARGETS}
+    LIBRARY DESTINATION ${LIBCXXABI_INSTALL_PREFIX}lib${LIBCXXABI_LIBDIR_SUFFIX} COMPONENT cxxabi
+    ARCHIVE DESTINATION ${LIBCXXABI_INSTALL_PREFIX}lib${LIBCXXABI_LIBDIR_SUFFIX} COMPONENT cxxabi
+    )
+endif()
 
-if (NOT CMAKE_CONFIGURATION_TYPES)
-  add_custom_target(install-libcxxabi
+if (NOT CMAKE_CONFIGURATION_TYPES AND LIBCXXABI_INSTALL_LIBRARY)
+  add_custom_target(install-cxxabi
     DEPENDS cxxabi
     COMMAND "${CMAKE_COMMAND}"
-            -DCMAKE_INSTALL_COMPONENT=libcxxabi
+            -DCMAKE_INSTALL_COMPONENT=cxxabi
             -P "${LIBCXXABI_BINARY_DIR}/cmake_install.cmake")
+  add_custom_target(install-cxxabi-stripped
+    DEPENDS cxxabi
+    COMMAND "${CMAKE_COMMAND}"
+            -DCMAKE_INSTALL_COMPONENT=cxxabi
+            -DCMAKE_INSTALL_DO_STRIP=1
+            -P "${LIBCXXABI_BINARY_DIR}/cmake_install.cmake")
+
+  # TODO: This is a legacy target name and should be removed at some point.
+  add_custom_target(install-libcxxabi DEPENDS install-cxxabi)
 endif()
diff --git a/lib/libcxxabi/src/abort_message.cpp b/lib/libcxxabi/src/abort_message.cpp
index 5e25c0f3472..7a2a9f835bd 100644
--- a/lib/libcxxabi/src/abort_message.cpp
+++ b/lib/libcxxabi/src/abort_message.cpp
@@ -22,8 +22,6 @@ extern "C" void android_set_abort_message(const char* msg);
 #endif // __ANDROID_API__ >= 21
 #endif // __BIONIC__
 
-#pragma GCC visibility push(hidden)
-
 #ifdef __APPLE__
 #   if defined(__has_include) && __has_include(<CrashReporterClient.h>)
 #       define HAVE_CRASHREPORTERCLIENT_H
@@ -31,10 +29,10 @@ extern "C" void android_set_abort_message(const char* msg);
 #   endif
 #endif
 
-__attribute__((visibility("hidden"), noreturn))
 void abort_message(const char* format, ...)
 {
     // write message to stderr
+#if !defined(NDEBUG) || !defined(LIBCXXABI_BAREMETAL)
 #ifdef __APPLE__
     fprintf(stderr, "libc++abi.dylib: ");
 #endif
@@ -43,6 +41,7 @@ void abort_message(const char* format, ...)
     vfprintf(stderr, format, list);
     va_end(list);
     fprintf(stderr, "\n");
+#endif
 
 #if defined(__APPLE__) && defined(HAVE_CRASHREPORTERCLIENT_H)
     // record message in crash report
@@ -77,5 +76,3 @@ void abort_message(const char* format, ...)
 
     abort();
 }
-
-#pragma GCC visibility pop
diff --git a/lib/libcxxabi/src/abort_message.h b/lib/libcxxabi/src/abort_message.h
index 2c5cb204664..e8f9571cb56 100644
--- a/lib/libcxxabi/src/abort_message.h
+++ b/lib/libcxxabi/src/abort_message.h
@@ -10,24 +10,18 @@
 #ifndef __ABORT_MESSAGE_H_
 #define __ABORT_MESSAGE_H_
 
-#include <stdio.h>
-
-#pragma GCC visibility push(hidden)
+#include "cxxabi.h"
 
 #ifdef __cplusplus
 extern "C" {
 #endif
 
-__attribute__((visibility("hidden"), noreturn))
-       void abort_message(const char* format, ...) 
-            __attribute__((format(printf, 1, 2)));
-
+_LIBCXXABI_HIDDEN _LIBCXXABI_NORETURN void
+abort_message(const char *format, ...) __attribute__((format(printf, 1, 2)));
 
 #ifdef __cplusplus
 }
 #endif
 
-#pragma GCC visibility pop
-
 #endif
 
diff --git a/lib/libcxxabi/src/cxa_aux_runtime.cpp b/lib/libcxxabi/src/cxa_aux_runtime.cpp
index bb7c9f1255c..878d3bd034d 100644
--- a/lib/libcxxabi/src/cxa_aux_runtime.cpp
+++ b/lib/libcxxabi/src/cxa_aux_runtime.cpp
@@ -16,7 +16,7 @@
 
 namespace __cxxabiv1 {
 extern "C" {
-_LIBCXXABI_FUNC_VIS LIBCXXABI_NORETURN void __cxa_bad_cast(void) {
+_LIBCXXABI_FUNC_VIS _LIBCXXABI_NORETURN void __cxa_bad_cast(void) {
 #ifndef _LIBCXXABI_NO_EXCEPTIONS
   throw std::bad_cast();
 #else
@@ -24,7 +24,7 @@ _LIBCXXABI_FUNC_VIS LIBCXXABI_NORETURN void __cxa_bad_cast(void) {
 #endif
 }
 
-_LIBCXXABI_FUNC_VIS LIBCXXABI_NORETURN void __cxa_bad_typeid(void) {
+_LIBCXXABI_FUNC_VIS _LIBCXXABI_NORETURN void __cxa_bad_typeid(void) {
 #ifndef _LIBCXXABI_NO_EXCEPTIONS
   throw std::bad_typeid();
 #else
@@ -32,7 +32,7 @@ _LIBCXXABI_FUNC_VIS LIBCXXABI_NORETURN void __cxa_bad_typeid(void) {
 #endif
 }
 
-_LIBCXXABI_FUNC_VIS LIBCXXABI_NORETURN void
+_LIBCXXABI_FUNC_VIS _LIBCXXABI_NORETURN void
 __cxa_throw_bad_array_new_length(void) {
 #ifndef _LIBCXXABI_NO_EXCEPTIONS
   throw std::bad_array_new_length();
diff --git a/lib/libcxxabi/src/cxa_default_handlers.cpp b/lib/libcxxabi/src/cxa_default_handlers.cpp
index 09350e7721a..f2e36b4bc83 100644
--- a/lib/libcxxabi/src/cxa_default_handlers.cpp
+++ b/lib/libcxxabi/src/cxa_default_handlers.cpp
@@ -12,8 +12,8 @@
 #include <stdexcept>
 #include <new>
 #include <exception>
+#include <cstdlib>
 #include "abort_message.h"
-#include "config.h" // For __sync_swap
 #include "cxxabi.h"
 #include "cxa_handlers.hpp"
 #include "cxa_exception.hpp"
@@ -22,7 +22,7 @@
 static const char* cause = "uncaught";
 
 __attribute__((noreturn))
-static void default_terminate_handler()
+static void demangling_terminate_handler()
 {
     // If there might be an uncaught exception
     using namespace __cxxabiv1;
@@ -78,12 +78,19 @@ static void default_terminate_handler()
 }
 
 __attribute__((noreturn))
-static void default_unexpected_handler() 
+static void demangling_unexpected_handler()
 {
     cause = "unexpected";
     std::terminate();
 }
 
+#if !defined(LIBCXXABI_SILENT_TERMINATE)
+static std::terminate_handler default_terminate_handler = demangling_terminate_handler;
+static std::terminate_handler default_unexpected_handler = demangling_unexpected_handler;
+#else
+static std::terminate_handler default_terminate_handler = std::abort;
+static std::terminate_handler default_unexpected_handler = std::terminate;
+#endif
 
 //
 // Global variables that hold the pointers to the current handler
diff --git a/lib/libcxxabi/src/cxa_demangle.cpp b/lib/libcxxabi/src/cxa_demangle.cpp
index 25aa741299a..9cfd99607bf 100644
--- a/lib/libcxxabi/src/cxa_demangle.cpp
+++ b/lib/libcxxabi/src/cxa_demangle.cpp
@@ -7,15 +7,20 @@
 //
 //===----------------------------------------------------------------------===//
 
-#define _LIBCPP_EXTERN_TEMPLATE(...)
+// FIXME: (possibly) incomplete list of features that clang mangles that this
+// file does not yet support:
+//   - enable_if attribute
+//   - decomposition declarations
+//   - C++ modules TS
+
 #define _LIBCPP_NO_EXCEPTIONS
 
 #include "__cxxabi_config.h"
 
 #include <vector>
 #include <algorithm>
-#include <string>
 #include <numeric>
+#include <cstdio>
 #include <cstdlib>
 #include <cstring>
 #include <cctype>
@@ -42,75 +47,1685 @@ enum
     success
 };
 
-template <class C>
-    const char* parse_type(const char* first, const char* last, C& db);
-template <class C>
-    const char* parse_encoding(const char* first, const char* last, C& db);
-template <class C>
-    const char* parse_name(const char* first, const char* last, C& db,
-                           bool* ends_with_template_args = 0);
-template <class C>
-    const char* parse_expression(const char* first, const char* last, C& db);
-template <class C>
-    const char* parse_template_args(const char* first, const char* last, C& db);
-template <class C>
-    const char* parse_operator_name(const char* first, const char* last, C& db);
-template <class C>
-    const char* parse_unqualified_name(const char* first, const char* last, C& db);
-template <class C>
-    const char* parse_decltype(const char* first, const char* last, C& db);
-
-template <class C>
-void
-print_stack(const C& db)
+class StringView {
+  const char *First;
+  const char *Last;
+
+public:
+  template <size_t N>
+  StringView(const char (&Str)[N]) : First(Str), Last(Str + N - 1) {}
+  StringView(const char *First_, const char *Last_) : First(First_), Last(Last_) {}
+  StringView() : First(nullptr), Last(nullptr) {}
+
+  StringView substr(size_t From, size_t To) {
+    if (To >= size())
+      To = size() - 1;
+    if (From >= size())
+      From = size() - 1;
+    return StringView(First + From, First + To);
+  }
+
+  StringView dropFront(size_t N) const {
+    if (N >= size())
+      N = size() - 1;
+    return StringView(First + N, Last);
+  }
+
+  bool startsWith(StringView Str) const {
+    if (Str.size() > size())
+      return false;
+    return std::equal(Str.begin(), Str.end(), begin());
+  }
+
+  const char &operator[](size_t Idx) const { return *(begin() + Idx); }
+
+  const char *begin() const { return First; }
+  const char *end() const { return Last; }
+  size_t size() const { return static_cast<size_t>(Last - First); }
+};
+
+bool operator==(const StringView &LHS, const StringView &RHS) {
+  return LHS.size() == RHS.size() &&
+         std::equal(LHS.begin(), LHS.end(), RHS.begin());
+}
+
+// Stream that AST nodes write their string representation into after the AST
+// has been parsed.
+class OutputStream {
+  char *Buffer;
+  size_t CurrentPosition;
+  size_t BufferCapacity;
+
+  // Ensure there is at least n more positions in buffer.
+  void grow(size_t N) {
+    if (N + CurrentPosition >= BufferCapacity) {
+      BufferCapacity *= 2;
+      if (BufferCapacity < N + CurrentPosition)
+        BufferCapacity = N + CurrentPosition;
+      Buffer = static_cast<char *>(std::realloc(Buffer, BufferCapacity));
+    }
+  }
+
+public:
+  OutputStream(char *StartBuf, size_t Size)
+      : Buffer(StartBuf), CurrentPosition(0), BufferCapacity(Size) {}
+
+  OutputStream &operator+=(StringView R) {
+    size_t Size = R.size();
+    if (Size == 0)
+      return *this;
+    grow(Size);
+    memmove(Buffer + CurrentPosition, R.begin(), Size);
+    CurrentPosition += Size;
+    return *this;
+  }
+
+  OutputStream &operator+=(char C) {
+    grow(1);
+    Buffer[CurrentPosition++] = C;
+    return *this;
+  }
+
+  // Offset of position in buffer, used for building stream_string_view.
+  typedef unsigned StreamPosition;
+
+  // StringView into a stream, used for caching the ast nodes.
+  class StreamStringView {
+    StreamPosition First, Last;
+
+    friend class OutputStream;
+
+  public:
+    StreamStringView() : First(0), Last(0) {}
+
+    StreamStringView(StreamPosition First_, StreamPosition Last_)
+        : First(First_), Last(Last_) {}
+
+    bool empty() const { return First == Last; }
+  };
+
+  OutputStream &operator+=(StreamStringView &s) {
+    size_t Sz = static_cast<size_t>(s.Last - s.First);
+    if (Sz == 0)
+      return *this;
+    grow(Sz);
+    memmove(Buffer + CurrentPosition, Buffer + s.First, Sz);
+    CurrentPosition += Sz;
+    return *this;
+  }
+
+  StreamPosition getCurrentPosition() const {
+    return static_cast<StreamPosition>(CurrentPosition);
+  }
+
+  StreamStringView makeStringViewFromPastPosition(StreamPosition Pos) {
+    return StreamStringView(Pos, getCurrentPosition());
+  }
+
+  char back() const {
+    return CurrentPosition ? Buffer[CurrentPosition - 1] : '\0';
+  }
+
+  bool empty() const { return CurrentPosition == 0; }
+
+  char *getBuffer() { return Buffer; }
+  char *getBufferEnd() { return Buffer + CurrentPosition - 1; }
+  size_t getBufferCapacity() { return BufferCapacity; }
+};
+
+// Base class of all AST nodes. The AST is built by the parser, then is
+// traversed by the printLeft/Right functions to produce a demangled string.
+class Node {
+public:
+  enum Kind : unsigned char {
+    KDotSuffix,
+    KVendorExtQualType,
+    KQualType,
+    KConversionOperatorType,
+    KPostfixQualifiedType,
+    KNameType,
+    KAbiTagAttr,
+    KObjCProtoName,
+    KPointerType,
+    KLValueReferenceType,
+    KRValueReferenceType,
+    KPointerToMemberType,
+    KArrayType,
+    KFunctionType,
+    KTopLevelFunctionDecl,
+    KFunctionQualType,
+    KFunctionRefQualType,
+    KLiteralOperator,
+    KSpecialName,
+    KCtorVtableSpecialName,
+    KQualifiedName,
+    KEmptyName,
+    KVectorType,
+    KTemplateParams,
+    KNameWithTemplateArgs,
+    KGlobalQualifiedName,
+    KStdQualifiedName,
+    KExpandedSpecialSubstitution,
+    KSpecialSubstitution,
+    KCtorDtorName,
+    KDtorName,
+    KUnnamedTypeName,
+    KLambdaTypeName,
+    KExpr,
+  };
+
+  const Kind K;
+
+private:
+  // If this Node has any RHS part, potentally many Nodes further down.
+  const unsigned HasRHSComponent : 1;
+  const unsigned HasFunction : 1;
+  const unsigned HasArray : 1;
+
+public:
+  Node(Kind K_, bool HasRHS_ = false, bool HasFunction_ = false,
+       bool HasArray_ = false)
+      : K(K_), HasRHSComponent(HasRHS_), HasFunction(HasFunction_),
+        HasArray(HasArray_) {}
+
+  bool hasRHSComponent() const { return HasRHSComponent; }
+  bool hasArray() const { return HasArray; }
+  bool hasFunction() const { return HasFunction; }
+
+  void print(OutputStream &s) const {
+    printLeft(s);
+    if (hasRHSComponent())
+      printRight(s);
+  }
+
+  // Print the "left" side of this Node into OutputStream.
+  virtual void printLeft(OutputStream &) const = 0;
+
+  // Print the "right". This distinction is necessary to represent C++ types
+  // that appear on the RHS of their subtype, such as arrays or functions.
+  // Since most types don't have such a component, provide a default
+  // implemenation.
+  virtual void printRight(OutputStream &) const {}
+
+  virtual StringView getBaseName() const { return StringView(); }
+
+  // Silence compiler warnings, this dtor will never be called.
+  virtual ~Node() = default;
+};
+
+class NodeArray {
+  Node **Elements;
+  size_t NumElements;
+
+public:
+  NodeArray() : NumElements(0) {}
+  NodeArray(Node **Elements_, size_t NumElements_)
+      : Elements(Elements_), NumElements(NumElements_) {}
+
+  bool empty() const { return NumElements == 0; }
+  size_t size() const { return NumElements; }
+
+  void printWithSeperator(OutputStream &S, StringView Seperator) const {
+    for (size_t Idx = 0; Idx != NumElements; ++Idx) {
+      if (Idx)
+        S += Seperator;
+      Elements[Idx]->print(S);
+    }
+  }
+};
+
+class DotSuffix final : public Node {
+  const Node *Prefix;
+  const StringView Suffix;
+
+public:
+  DotSuffix(Node *Prefix_, StringView Suffix_)
+      : Node(KDotSuffix), Prefix(Prefix_), Suffix(Suffix_) {}
+
+  void printLeft(OutputStream &s) const override {
+    Prefix->print(s);
+    s += " (";
+    s += Suffix;
+    s += ")";
+  }
+};
+
+class VendorExtQualType final : public Node {
+  const Node *Ext;
+  const Node *Ty;
+
+public:
+  VendorExtQualType(Node *Ext_, Node *Ty_)
+      : Node(KVendorExtQualType), Ext(Ext_), Ty(Ty_) {}
+
+  void printLeft(OutputStream &S) const override {
+    Ext->print(S);
+    S += " ";
+    Ty->printLeft(S);
+  }
+
+  void printRight(OutputStream &S) const override { Ty->printRight(S); }
+};
+
+enum Qualifiers {
+  QualNone = 0,
+  QualConst = 0x1,
+  QualVolatile = 0x2,
+  QualRestrict = 0x4,
+};
+
+void addQualifiers(Qualifiers &Q1, Qualifiers Q2) {
+  Q1 = static_cast<Qualifiers>(Q1 | Q2);
+}
+
+class QualType : public Node {
+protected:
+  const Qualifiers Quals;
+  const Node *Child;
+
+  void printQuals(OutputStream &S) const {
+    if (Quals & QualConst)
+      S += " const";
+    if (Quals & QualVolatile)
+      S += " volatile";
+    if (Quals & QualRestrict)
+      S += " restrict";
+  }
+
+public:
+  QualType(Node *Child_, Qualifiers Quals_)
+      : Node(KQualType, Child_->hasRHSComponent(), Child_->hasFunction(),
+             Child_->hasArray()),
+        Quals(Quals_), Child(Child_) {}
+
+  QualType(Node::Kind ChildKind_, Node *Child_, Qualifiers Quals_)
+      : Node(ChildKind_, Child_->hasRHSComponent(), Child_->hasFunction(),
+             Child_->hasArray()),
+        Quals(Quals_), Child(Child_) {}
+
+  void printLeft(OutputStream &S) const override {
+    Child->printLeft(S);
+    printQuals(S);
+  }
+
+  void printRight(OutputStream &S) const override { Child->printRight(S); }
+};
+
+class ConversionOperatorType final : public Node {
+  const Node *Ty;
+
+public:
+  ConversionOperatorType(Node *Ty_) : Node(KConversionOperatorType), Ty(Ty_) {}
+
+  void printLeft(OutputStream &S) const override {
+    S += "operator ";
+    Ty->print(S);
+  }
+};
+
+class PostfixQualifiedType final : public Node {
+  const Node *Ty;
+  const StringView Postfix;
+
+public:
+  PostfixQualifiedType(Node *Ty_, StringView Postfix_)
+      : Node(KPostfixQualifiedType), Ty(Ty_), Postfix(Postfix_) {}
+
+  void printLeft(OutputStream &s) const override {
+    Ty->printLeft(s);
+    s += Postfix;
+  }
+
+  void printRight(OutputStream &S) const override { Ty->printRight(S); }
+};
+
+class NameType final : public Node {
+  const StringView Name;
+
+public:
+  NameType(StringView Name_) : Node(KNameType), Name(Name_) {}
+
+  StringView getName() const { return Name; }
+  StringView getBaseName() const override { return Name; }
+
+  void printLeft(OutputStream &s) const override { s += Name; }
+};
+
+class AbiTagAttr final : public Node {
+  const Node* Base;
+  StringView Tag;
+public:
+  AbiTagAttr(const Node* Base_, StringView Tag_)
+      : Node(KAbiTagAttr), Base(Base_), Tag(Tag_) {}
+
+  void printLeft(OutputStream &S) const override {
+    Base->printLeft(S);
+    S += "[abi:";
+    S += Tag;
+    S += "]";
+  }
+};
+
+class ObjCProtoName : public Node {
+  Node *Ty;
+  Node *Protocol;
+
+  friend class PointerType;
+
+public:
+  ObjCProtoName(Node *Ty_, Node *Protocol_)
+      : Node(KObjCProtoName), Ty(Ty_), Protocol(Protocol_) {}
+
+  bool isObjCObject() const {
+    return Ty->K == KNameType &&
+           static_cast<NameType *>(Ty)->getName() == "objc_object";
+  }
+
+  void printLeft(OutputStream &S) const override {
+    Ty->printLeft(S);
+    S += "<";
+    Protocol->printLeft(S);
+    S += ">";
+  }
+};
+
+class PointerType final : public Node {
+  const Node *Pointee;
+
+public:
+  PointerType(Node *Pointee_)
+      : Node(KPointerType, Pointee_->hasRHSComponent()), Pointee(Pointee_) {}
+
+  void printLeft(OutputStream &s) const override {
+    // We rewrite objc_object<SomeProtocol>* into id<SomeProtocol>.
+    if (Pointee->K != KObjCProtoName ||
+        !static_cast<const ObjCProtoName *>(Pointee)->isObjCObject()) {
+      Pointee->printLeft(s);
+      if (Pointee->hasArray())
+        s += " ";
+      if (Pointee->hasArray() || Pointee->hasFunction())
+        s += "(";
+      s += "*";
+    } else {
+      const auto *objcProto = static_cast<const ObjCProtoName *>(Pointee);
+      s += "id<";
+      objcProto->Protocol->print(s);
+      s += ">";
+    }
+  }
+
+  void printRight(OutputStream &s) const override {
+    if (Pointee->K != KObjCProtoName ||
+        !static_cast<const ObjCProtoName *>(Pointee)->isObjCObject()) {
+      if (Pointee->hasArray() || Pointee->hasFunction())
+        s += ")";
+      Pointee->printRight(s);
+    }
+  }
+};
+
+class LValueReferenceType final : public Node {
+  const Node *Pointee;
+
+public:
+  LValueReferenceType(Node *Pointee_)
+      : Node(KLValueReferenceType, Pointee_->hasRHSComponent()),
+        Pointee(Pointee_) {}
+
+  void printLeft(OutputStream &s) const override {
+    Pointee->printLeft(s);
+    if (Pointee->hasArray())
+      s += " ";
+    if (Pointee->hasArray() || Pointee->hasFunction())
+      s += "(&";
+    else
+      s += "&";
+  }
+  void printRight(OutputStream &s) const override {
+    if (Pointee->hasArray() || Pointee->hasFunction())
+      s += ")";
+    Pointee->printRight(s);
+  }
+};
+
+class RValueReferenceType final : public Node {
+  const Node *Pointee;
+
+public:
+  RValueReferenceType(Node *Pointee_)
+      : Node(KRValueReferenceType, Pointee_->hasRHSComponent()),
+        Pointee(Pointee_) {}
+
+  void printLeft(OutputStream &s) const override {
+    Pointee->printLeft(s);
+    if (Pointee->hasArray())
+      s += " ";
+    if (Pointee->hasArray() || Pointee->hasFunction())
+      s += "(&&";
+    else
+      s += "&&";
+  }
+
+  void printRight(OutputStream &s) const override {
+    if (Pointee->hasArray() || Pointee->hasFunction())
+      s += ")";
+    Pointee->printRight(s);
+  }
+};
+
+class PointerToMemberType final : public Node {
+  const Node *ClassType;
+  const Node *MemberType;
+
+public:
+  PointerToMemberType(Node *ClassType_, Node *MemberType_)
+      : Node(KPointerToMemberType, MemberType_->hasRHSComponent()),
+        ClassType(ClassType_), MemberType(MemberType_) {}
+
+  void printLeft(OutputStream &s) const override {
+    MemberType->printLeft(s);
+    if (MemberType->hasArray() || MemberType->hasFunction())
+      s += "(";
+    else
+      s += " ";
+    ClassType->print(s);
+    s += "::*";
+  }
+
+  void printRight(OutputStream &s) const override {
+    if (MemberType->hasArray() || MemberType->hasFunction())
+      s += ")";
+    MemberType->printRight(s);
+  }
+};
+
+class NodeOrString {
+  const void *First;
+  const void *Second;
+
+public:
+  /* implicit */ NodeOrString(StringView Str) {
+    const char *FirstChar = Str.begin();
+    const char *SecondChar = Str.end();
+    if (SecondChar == nullptr) {
+      assert(FirstChar == SecondChar);
+      ++FirstChar, ++SecondChar;
+    }
+    First = static_cast<const void *>(FirstChar);
+    Second = static_cast<const void *>(SecondChar);
+  }
+
+  /* implicit */ NodeOrString(Node *N)
+      : First(static_cast<const void *>(N)), Second(nullptr) {}
+  NodeOrString() : First(nullptr), Second(nullptr) {}
+
+  bool isString() const { return Second && First; }
+  bool isNode() const { return First && !Second; }
+  bool isEmpty() const { return !First && !Second; }
+
+  StringView asString() const {
+    assert(isString());
+    return StringView(static_cast<const char *>(First),
+                      static_cast<const char *>(Second));
+  }
+
+  const Node *asNode() const {
+    assert(isNode());
+    return static_cast<const Node *>(First);
+  }
+};
+
+class ArrayType final : public Node {
+  Node *Base;
+  NodeOrString Dimension;
+
+public:
+  ArrayType(Node *Base_, NodeOrString Dimension_)
+      : Node(KArrayType, true, false, true), Base(Base_), Dimension(Dimension_) {}
+
+  // Incomplete array type.
+  ArrayType(Node *Base_) : Node(KArrayType, true, false, true), Base(Base_) {}
+
+  void printLeft(OutputStream &S) const override { Base->printLeft(S); }
+
+  void printRight(OutputStream &S) const override {
+    if (S.back() != ']')
+      S += " ";
+    S += "[";
+    if (Dimension.isString())
+      S += Dimension.asString();
+    else if (Dimension.isNode())
+      Dimension.asNode()->print(S);
+    S += "]";
+    Base->printRight(S);
+  }
+};
+
+class FunctionType final : public Node {
+  Node *Ret;
+  NodeArray Params;
+
+public:
+  FunctionType(Node *Ret_, NodeArray Params_)
+      : Node(KFunctionType, true, true), Ret(Ret_), Params(Params_) {}
+
+  // Handle C++'s ... quirky decl grammer by using the left & right
+  // distinction. Consider:
+  //   int (*f(float))(char) {}
+  // f is a function that takes a float and returns a pointer to a function
+  // that takes a char and returns an int. If we're trying to print f, start
+  // by printing out the return types's left, then print our parameters, then
+  // finally print right of the return type.
+  void printLeft(OutputStream &S) const override {
+    Ret->printLeft(S);
+    S += " ";
+  }
+
+  void printRight(OutputStream &S) const override {
+    S += "(";
+    Params.printWithSeperator(S, ", ");
+    S += ")";
+    Ret->printRight(S);
+  }
+};
+
+class TopLevelFunctionDecl final : public Node {
+  const Node *Ret;
+  const Node *Name;
+  NodeArray Params;
+
+public:
+  TopLevelFunctionDecl(Node *Ret_, Node *Name_, NodeArray Params_)
+      : Node(KTopLevelFunctionDecl, true, true), Ret(Ret_), Name(Name_),
+        Params(Params_) {}
+
+  void printLeft(OutputStream &S) const override {
+    if (Ret) {
+      Ret->printLeft(S);
+      if (!Ret->hasRHSComponent())
+        S += " ";
+    }
+    Name->print(S);
+  }
+
+  void printRight(OutputStream &S) const override {
+    S += "(";
+    Params.printWithSeperator(S, ", ");
+    S += ")";
+    if (Ret)
+      Ret->printRight(S);
+  }
+};
+
+enum FunctionRefQual : unsigned char {
+  FrefQualNone,
+  FrefQualLValue,
+  FrefQualRValue,
+};
+
+class FunctionRefQualType : public Node {
+  Node *Fn;
+  FunctionRefQual Quals;
+
+  friend class FunctionQualType;
+
+public:
+  FunctionRefQualType(Node *Fn_, FunctionRefQual Quals_)
+      : Node(KFunctionRefQualType, true, true), Fn(Fn_), Quals(Quals_) {}
+
+  void printQuals(OutputStream &S) const {
+    if (Quals == FrefQualLValue)
+      S += " &";
+    else
+      S += " &&";
+  }
+
+  void printLeft(OutputStream &S) const override { Fn->printLeft(S); }
+
+  void printRight(OutputStream &S) const override {
+    Fn->printRight(S);
+    printQuals(S);
+  }
+};
+
+class FunctionQualType final : public QualType {
+public:
+  FunctionQualType(Node *Child_, Qualifiers Quals_)
+      : QualType(KFunctionQualType, Child_, Quals_) {}
+
+  void printLeft(OutputStream &S) const override { Child->printLeft(S); }
+
+  void printRight(OutputStream &S) const override {
+    if (Child->K == KFunctionRefQualType) {
+      auto *RefQuals = static_cast<const FunctionRefQualType *>(Child);
+      RefQuals->Fn->printRight(S);
+      printQuals(S);
+      RefQuals->printQuals(S);
+    } else {
+      Child->printRight(S);
+      printQuals(S);
+    }
+  }
+};
+
+class LiteralOperator : public Node {
+  const Node *OpName;
+
+public:
+  LiteralOperator(Node *OpName_) : Node(KLiteralOperator), OpName(OpName_) {}
+
+  void printLeft(OutputStream &S) const override {
+    S += "operator\"\" ";
+    OpName->print(S);
+  }
+};
+
+class SpecialName final : public Node {
+  const StringView Special;
+  const Node *Child;
+
+public:
+  SpecialName(StringView Special_, Node *Child_)
+      : Node(KSpecialName), Special(Special_), Child(Child_) {}
+
+  void printLeft(OutputStream &S) const override {
+    S += Special;
+    Child->print(S);
+  }
+};
+
+class CtorVtableSpecialName final : public Node {
+  const Node *FirstType;
+  const Node *SecondType;
+
+public:
+  CtorVtableSpecialName(Node *FirstType_, Node *SecondType_)
+      : Node(KCtorVtableSpecialName), FirstType(FirstType_),
+        SecondType(SecondType_) {}
+
+  void printLeft(OutputStream &S) const override {
+    S += "construction vtable for ";
+    FirstType->print(S);
+    S += "-in-";
+    SecondType->print(S);
+  }
+};
+
+class QualifiedName final : public Node {
+  // qualifier::name
+  const Node *Qualifier;
+  const Node *Name;
+
+  mutable OutputStream::StreamStringView Cache;
+
+public:
+  QualifiedName(Node *Qualifier_, Node *Name_)
+      : Node(KQualifiedName), Qualifier(Qualifier_), Name(Name_) {}
+
+  StringView getBaseName() const override { return Name->getBaseName(); }
+
+  void printLeft(OutputStream &S) const override {
+    if (!Cache.empty()) {
+      S += Cache;
+      return;
+    }
+
+    OutputStream::StreamPosition Start = S.getCurrentPosition();
+    if (Qualifier->K != KEmptyName) {
+      Qualifier->print(S);
+      S += "::";
+    }
+    Name->print(S);
+    Cache = S.makeStringViewFromPastPosition(Start);
+  }
+};
+
+class EmptyName : public Node {
+public:
+  EmptyName() : Node(KEmptyName) {}
+  void printLeft(OutputStream &) const override {}
+};
+
+class VectorType final : public Node {
+  const Node *BaseType;
+  const NodeOrString Dimension;
+  const bool IsPixel;
+
+public:
+  VectorType(NodeOrString Dimension_)
+      : Node(KVectorType), BaseType(nullptr), Dimension(Dimension_),
+        IsPixel(true) {}
+  VectorType(Node *BaseType_, NodeOrString Dimension_)
+      : Node(KVectorType), BaseType(BaseType_), Dimension(Dimension_),
+        IsPixel(false) {}
+
+  void printLeft(OutputStream &S) const override {
+    if (IsPixel) {
+      S += "pixel vector[";
+      S += Dimension.asString();
+      S += "]";
+    } else {
+      BaseType->print(S);
+      S += " vector[";
+      if (Dimension.isNode())
+        Dimension.asNode()->print(S);
+      else if (Dimension.isString())
+        S += Dimension.asString();
+      S += "]";
+    }
+  }
+};
+
+class TemplateParams final : public Node {
+  NodeArray Params;
+
+  mutable OutputStream::StreamStringView Cache;
+
+public:
+  TemplateParams(NodeArray Params_) : Node(KTemplateParams), Params(Params_) {}
+
+  void printLeft(OutputStream &S) const override {
+    if (!Cache.empty()) {
+      S += Cache;
+      return;
+    }
+
+    OutputStream::StreamPosition Start = S.getCurrentPosition();
+
+    S += "<";
+    Params.printWithSeperator(S, ", ");
+    if (S.back() == '>')
+      S += " ";
+    S += ">";
+
+    Cache = S.makeStringViewFromPastPosition(Start);
+  }
+};
+
+class NameWithTemplateArgs final : public Node {
+  // name<template_args>
+  Node *Name;
+  Node *TemplateArgs;
+
+public:
+  NameWithTemplateArgs(Node *Name_, Node *TemplateArgs_)
+      : Node(KNameWithTemplateArgs), Name(Name_), TemplateArgs(TemplateArgs_) {}
+
+  StringView getBaseName() const override { return Name->getBaseName(); }
+
+  void printLeft(OutputStream &S) const override {
+    Name->print(S);
+    TemplateArgs->print(S);
+  }
+};
+
+class GlobalQualifiedName final : public Node {
+  Node *Child;
+
+public:
+  GlobalQualifiedName(Node *Child_) : Node(KGlobalQualifiedName), Child(Child_) {}
+
+  StringView getBaseName() const override { return Child->getBaseName(); }
+
+  void printLeft(OutputStream &S) const override {
+    S += "::";
+    Child->print(S);
+  }
+};
+
+class StdQualifiedName final : public Node {
+  Node *Child;
+
+public:
+  StdQualifiedName(Node *Child_) : Node(KStdQualifiedName), Child(Child_) {}
+
+  StringView getBaseName() const override { return Child->getBaseName(); }
+
+  void printLeft(OutputStream &S) const override {
+    S += "std::";
+    Child->print(S);
+  }
+};
+
+enum class SpecialSubKind {
+  allocator,
+  basic_string,
+  string,
+  istream,
+  ostream,
+  iostream,
+};
+
+class ExpandedSpecialSubstitution final : public Node {
+  SpecialSubKind SSK;
+
+public:
+  ExpandedSpecialSubstitution(SpecialSubKind SSK_)
+      : Node(KExpandedSpecialSubstitution), SSK(SSK_) {}
+
+  StringView getBaseName() const override {
+    switch (SSK) {
+    case SpecialSubKind::allocator:
+      return StringView("allocator");
+    case SpecialSubKind::basic_string:
+      return StringView("basic_string");
+    case SpecialSubKind::string:
+      return StringView("basic_string");
+    case SpecialSubKind::istream:
+      return StringView("basic_istream");
+    case SpecialSubKind::ostream:
+      return StringView("basic_ostream");
+    case SpecialSubKind::iostream:
+      return StringView("basic_iostream");
+    }
+    _LIBCPP_UNREACHABLE();
+  }
+
+  void printLeft(OutputStream &S) const override {
+    switch (SSK) {
+    case SpecialSubKind::allocator:
+      S += "std::basic_string<char, std::char_traits<char>, "
+           "std::allocator<char> >";
+      break;
+    case SpecialSubKind::basic_string:
+    case SpecialSubKind::string:
+      S += "std::basic_string<char, std::char_traits<char>, "
+           "std::allocator<char> >";
+      break;
+    case SpecialSubKind::istream:
+      S += "std::basic_istream<char, std::char_traits<char> >";
+      break;
+    case SpecialSubKind::ostream:
+      S += "std::basic_ostream<char, std::char_traits<char> >";
+      break;
+    case SpecialSubKind::iostream:
+      S += "std::basic_iostream<char, std::char_traits<char> >";
+      break;
+    }
+  }
+};
+
+class SpecialSubstitution final : public Node {
+public:
+  SpecialSubKind SSK;
+
+  SpecialSubstitution(SpecialSubKind SSK_)
+      : Node(KSpecialSubstitution), SSK(SSK_) {}
+
+  StringView getBaseName() const override {
+    switch (SSK) {
+    case SpecialSubKind::allocator:
+      return StringView("allocator");
+    case SpecialSubKind::basic_string:
+      return StringView("basic_string");
+    case SpecialSubKind::string:
+      return StringView("string");
+    case SpecialSubKind::istream:
+      return StringView("istream");
+    case SpecialSubKind::ostream:
+      return StringView("ostream");
+    case SpecialSubKind::iostream:
+      return StringView("iostream");
+    }
+    _LIBCPP_UNREACHABLE();
+  }
+
+  void printLeft(OutputStream &S) const override {
+    switch (SSK) {
+    case SpecialSubKind::allocator:
+      S += "std::allocator";
+      break;
+    case SpecialSubKind::basic_string:
+      S += "std::basic_string";
+      break;
+    case SpecialSubKind::string:
+      S += "std::string";
+      break;
+    case SpecialSubKind::istream:
+      S += "std::istream";
+      break;
+    case SpecialSubKind::ostream:
+      S += "std::ostream";
+      break;
+    case SpecialSubKind::iostream:
+      S += "std::iostream";
+      break;
+    }
+  }
+};
+
+class CtorDtorName final : public Node {
+  const Node *Basename;
+  const bool IsDtor;
+
+public:
+  CtorDtorName(Node *Basename_, bool IsDtor_)
+      : Node(KCtorDtorName), Basename(Basename_), IsDtor(IsDtor_) {}
+
+  void printLeft(OutputStream &S) const override {
+    if (IsDtor)
+      S += "~";
+    S += Basename->getBaseName();
+  }
+};
+
+class DtorName : public Node {
+  const Node *Base;
+
+public:
+  DtorName(Node *Base_) : Node(KDtorName), Base(Base_) {}
+
+  void printLeft(OutputStream &S) const override {
+    S += "~";
+    Base->printLeft(S);
+  }
+};
+
+class UnnamedTypeName : public Node {
+  const StringView Count;
+
+public:
+  UnnamedTypeName(StringView Count_) : Node(KUnnamedTypeName), Count(Count_) {}
+
+  void printLeft(OutputStream &S) const override {
+    S += "'unnamed";
+    S += Count;
+    S += "\'";
+  }
+};
+
+class LambdaTypeName : public Node {
+  NodeArray Params;
+  StringView Count;
+
+public:
+  LambdaTypeName(NodeArray Params_, StringView Count_)
+      : Node(KLambdaTypeName), Params(Params_), Count(Count_) {}
+
+  void printLeft(OutputStream &S) const override {
+    S += "\'lambda";
+    S += Count;
+    S += "\'(";
+    Params.printWithSeperator(S, ", ");
+    S += ")";
+  }
+};
+
+// -- Expression Nodes --
+
+struct Expr : public Node {
+  Expr() : Node(KExpr) {}
+};
+
+class BinaryExpr : public Expr {
+  const Node *LHS;
+  const StringView InfixOperator;
+  const Node *RHS;
+
+public:
+  BinaryExpr(Node *LHS_, StringView InfixOperator_, Node *RHS_)
+      : LHS(LHS_), InfixOperator(InfixOperator_), RHS(RHS_) {}
+
+  void printLeft(OutputStream &S) const override {
+    // might be a template argument expression, then we need to disambiguate
+    // with parens.
+    if (InfixOperator == ">")
+      S += "(";
+
+    S += "(";
+    LHS->print(S);
+    S += ") ";
+    S += InfixOperator;
+    S += " (";
+    RHS->print(S);
+    S += ")";
+
+    if (InfixOperator == ">")
+      S += ")";
+  }
+};
+
+class ArraySubscriptExpr : public Expr {
+  const Node *Op1;
+  const Node *Op2;
+
+public:
+  ArraySubscriptExpr(Node *Op1_, Node *Op2_) : Op1(Op1_), Op2(Op2_) {}
+
+  void printLeft(OutputStream &S) const override {
+    S += "(";
+    Op1->print(S);
+    S += ")[";
+    Op2->print(S);
+    S += "]";
+  }
+};
+
+class PostfixExpr : public Expr {
+  const Node *Child;
+  const StringView Operand;
+
+public:
+  PostfixExpr(Node *Child_, StringView Operand_)
+      : Child(Child_), Operand(Operand_) {}
+
+  void printLeft(OutputStream &S) const override {
+    S += "(";
+    Child->print(S);
+    S += ")";
+    S += Operand;
+  }
+};
+
+class ConditionalExpr : public Expr {
+  const Node *Cond;
+  const Node *Then;
+  const Node *Else;
+
+public:
+  ConditionalExpr(Node *Cond_, Node *Then_, Node *Else_)
+      : Cond(Cond_), Then(Then_), Else(Else_) {}
+
+  void printLeft(OutputStream &S) const override {
+    S += "(";
+    Cond->print(S);
+    S += ") ? (";
+    Then->print(S);
+    S += ") : (";
+    Else->print(S);
+    S += ")";
+  }
+};
+
+class MemberExpr : public Expr {
+  const Node *LHS;
+  const StringView Kind;
+  const Node *RHS;
+
+public:
+  MemberExpr(Node *LHS_, StringView Kind_, Node *RHS_)
+      : LHS(LHS_), Kind(Kind_), RHS(RHS_) {}
+
+  void printLeft(OutputStream &S) const override {
+    LHS->print(S);
+    S += Kind;
+    RHS->print(S);
+  }
+};
+
+class EnclosingExpr : public Expr {
+  const StringView Prefix;
+  const Node *Infix;
+  const StringView Postfix;
+
+public:
+  EnclosingExpr(StringView Prefix_, Node *Infix_, StringView Postfix_)
+      : Prefix(Prefix_), Infix(Infix_), Postfix(Postfix_) {}
+
+  void printLeft(OutputStream &S) const override {
+    S += Prefix;
+    Infix->print(S);
+    S += Postfix;
+  }
+};
+
+class CastExpr : public Expr {
+  // cast_kind<to>(from)
+  const StringView CastKind;
+  const Node *To;
+  const Node *From;
+
+public:
+  CastExpr(StringView CastKind_, Node *To_, Node *From_)
+      : CastKind(CastKind_), To(To_), From(From_) {}
+
+  void printLeft(OutputStream &S) const override {
+    S += CastKind;
+    S += "<";
+    To->printLeft(S);
+    S += ">(";
+    From->printLeft(S);
+    S += ")";
+  }
+};
+
+class SizeofParamPackExpr : public Expr {
+  NodeArray Args;
+
+public:
+  SizeofParamPackExpr(NodeArray Args_) : Args(Args_) {}
+
+  void printLeft(OutputStream &S) const override {
+    S += "sizeof...(";
+    Args.printWithSeperator(S, ", ");
+    S += ")";
+  }
+};
+
+class CallExpr : public Expr {
+  const Node *Callee;
+  NodeArray Args;
+
+public:
+  CallExpr(Node *Callee_, NodeArray Args_) : Callee(Callee_), Args(Args_) {}
+
+  void printLeft(OutputStream &S) const override {
+    Callee->print(S);
+    S += "(";
+    Args.printWithSeperator(S, ", ");
+    S += ")";
+  }
+};
+
+class NewExpr : public Expr {
+  // new (expr_list) type(init_list)
+  NodeArray ExprList;
+  Node *Type;
+  NodeArray InitList;
+  bool IsGlobal; // ::operator new ?
+  bool IsArray;  // new[] ?
+public:
+  NewExpr(NodeArray ExprList_, Node *Type_, NodeArray InitList_, bool IsGlobal_,
+          bool IsArray_)
+      : ExprList(ExprList_), Type(Type_), InitList(InitList_), IsGlobal(IsGlobal_),
+        IsArray(IsArray_) {}
+
+  void printLeft(OutputStream &S) const override {
+    if (IsGlobal)
+      S += "::operator ";
+    S += "new";
+    if (IsArray)
+      S += "[]";
+    if (!ExprList.empty()) {
+      S += "(";
+      ExprList.printWithSeperator(S, ", ");
+      S += ")";
+    }
+    Type->print(S);
+    if (!InitList.empty()) {
+      S += "(";
+      InitList.printWithSeperator(S, ", ");
+      S += ")";
+    }
+  }
+};
+
+class DeleteExpr : public Expr {
+  Node *Op;
+  bool IsGlobal;
+  bool IsArray;
+
+public:
+  DeleteExpr(Node *Op_, bool IsGlobal_, bool IsArray_)
+      : Op(Op_), IsGlobal(IsGlobal_), IsArray(IsArray_) {}
+
+  void printLeft(OutputStream &S) const override {
+    if (IsGlobal)
+      S += "::";
+    S += "delete";
+    if (IsArray)
+      S += "[] ";
+    Op->print(S);
+  }
+};
+
+class PrefixExpr : public Expr {
+  StringView Prefix;
+  Node *Child;
+
+public:
+  PrefixExpr(StringView Prefix_, Node *Child_) : Prefix(Prefix_), Child(Child_) {}
+
+  void printLeft(OutputStream &S) const override {
+    S += Prefix;
+    S += "(";
+    Child->print(S);
+    S += ")";
+  }
+};
+
+class FunctionParam : public Expr {
+  StringView Number;
+
+public:
+  FunctionParam(StringView Number_) : Number(Number_) {}
+
+  void printLeft(OutputStream &S) const override {
+    S += "fp";
+    S += Number;
+  }
+};
+
+class ExprList : public Expr {
+  NodeArray SubExprs;
+
+public:
+  ExprList(NodeArray SubExprs_) : SubExprs(SubExprs_) {}
+
+  void printLeft(OutputStream &S) const override {
+    S += "(";
+    SubExprs.printWithSeperator(S, ", ");
+    S += ")";
+  }
+};
+
+class ConversionExpr : public Expr {
+  NodeArray Expressions;
+  NodeArray Types;
+
+public:
+  ConversionExpr(NodeArray Expressions_, NodeArray Types_)
+      : Expressions(Expressions_), Types(Types_) {}
+
+  void printLeft(OutputStream &S) const override {
+    S += "(";
+    Expressions.printWithSeperator(S, ", ");
+    S += ")(";
+    Types.printWithSeperator(S, ", ");
+    S += ")";
+  }
+};
+
+class ThrowExpr : public Expr {
+  const Node *Op;
+
+public:
+  ThrowExpr(Node *Op_) : Op(Op_) {}
+
+  void printLeft(OutputStream &S) const override {
+    S += "throw ";
+    Op->print(S);
+  }
+};
+
+class BoolExpr : public Expr {
+  bool Value;
+
+public:
+  BoolExpr(bool Value_) : Value(Value_) {}
+
+  void printLeft(OutputStream &S) const override {
+    S += Value ? StringView("true") : StringView("false");
+  }
+};
+
+class IntegerCastExpr : public Expr {
+  // ty(integer)
+  Node *Ty;
+  StringView Integer;
+
+public:
+  IntegerCastExpr(Node *Ty_, StringView Integer_) : Ty(Ty_), Integer(Integer_) {}
+
+  void printLeft(OutputStream &S) const override {
+    S += "(";
+    Ty->print(S);
+    S += ")";
+    S += Integer;
+  }
+};
+
+class IntegerExpr : public Expr {
+  StringView Type;
+  StringView Value;
+
+public:
+  IntegerExpr(StringView Type_, StringView Value_) : Type(Type_), Value(Value_) {}
+
+  void printLeft(OutputStream &S) const override {
+    if (Type.size() > 3) {
+      S += "(";
+      S += Type;
+      S += ")";
+    }
+
+    if (Value[0] == 'n') {
+      S += "-";
+      S += Value.dropFront(1);
+    } else
+      S += Value;
+
+    if (Type.size() <= 3)
+      S += Type;
+  }
+};
+
+template <class Float> struct FloatData;
+
+template <class Float> class FloatExpr : public Expr {
+  const StringView Contents;
+
+public:
+  FloatExpr(StringView Contents_) : Contents(Contents_) {}
+
+  void printLeft(OutputStream &s) const override {
+    const char *first = Contents.begin();
+    const char *last = Contents.end() + 1;
+
+    const size_t N = FloatData<Float>::mangled_size;
+    if (static_cast<std::size_t>(last - first) > N) {
+      last = first + N;
+      union {
+        Float value;
+        char buf[sizeof(Float)];
+      };
+      const char *t = first;
+      char *e = buf;
+      for (; t != last; ++t, ++e) {
+        unsigned d1 = isdigit(*t) ? static_cast<unsigned>(*t - '0')
+                                  : static_cast<unsigned>(*t - 'a' + 10);
+        ++t;
+        unsigned d0 = isdigit(*t) ? static_cast<unsigned>(*t - '0')
+                                  : static_cast<unsigned>(*t - 'a' + 10);
+        *e = static_cast<char>((d1 << 4) + d0);
+      }
+#if __BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__
+      std::reverse(buf, e);
+#endif
+      char num[FloatData<Float>::max_demangled_size] = {0};
+      int n = snprintf(num, sizeof(num), FloatData<Float>::spec, value);
+      s += StringView(num, num + n);
+    }
+  }
+};
+
+class BumpPointerAllocator {
+  struct BlockMeta {
+    BlockMeta* Next;
+    size_t Current;
+  };
+
+  static constexpr size_t AllocSize = 4096;
+  static constexpr size_t UsableAllocSize = AllocSize - sizeof(BlockMeta);
+
+  alignas(16) char InitialBuffer[AllocSize];
+  BlockMeta* BlockList = nullptr;
+
+  void grow() {
+    char* NewMeta = new char[AllocSize];
+    BlockList = new (NewMeta) BlockMeta{BlockList, 0};
+  }
+
+  void* allocateMassive(size_t NBytes) {
+    NBytes += sizeof(BlockMeta);
+    BlockMeta* NewMeta = reinterpret_cast<BlockMeta*>(new char[NBytes]);
+    BlockList->Next = new (NewMeta) BlockMeta{BlockList->Next, 0};
+    return static_cast<void*>(NewMeta + 1);
+  }
+
+public:
+  BumpPointerAllocator()
+      : BlockList(new (InitialBuffer) BlockMeta{nullptr, 0}) {}
+
+  void* allocate(size_t N) {
+    N = (N + 15u) & ~15u;
+    if (N + BlockList->Current >= UsableAllocSize) {
+      if (N > UsableAllocSize)
+        return allocateMassive(N);
+      grow();
+    }
+    BlockList->Current += N;
+    return static_cast<void*>(reinterpret_cast<char*>(BlockList + 1) +
+                              BlockList->Current - N);
+  }
+
+  ~BumpPointerAllocator() {
+    while (BlockList) {
+      BlockMeta* Tmp = BlockList;
+      BlockList = BlockList->Next;
+      if (reinterpret_cast<char*>(Tmp) != InitialBuffer)
+        delete[] reinterpret_cast<char*>(Tmp);
+    }
+  }
+};
+
+template <class T, size_t N>
+class PODSmallVector {
+  static_assert(std::is_pod<T>::value,
+                "T is required to be a plain old data type");
+
+  T* First;
+  T* Last;
+  T* Cap;
+  T Inline[N];
+
+  bool isInline() const { return First == Inline; }
+
+  void clearInline() {
+    First = Inline;
+    Last = Inline;
+    Cap = Inline + N;
+  }
+
+  void reserve(size_t NewCap) {
+    size_t S = size();
+    if (isInline()) {
+      auto* Tmp = static_cast<T*>(std::malloc(NewCap * sizeof(T)));
+      std::copy(First, Last, Tmp);
+      First = Tmp;
+    } else
+      First = static_cast<T*>(std::realloc(First, NewCap * sizeof(T)));
+    Last = First + S;
+    Cap = First + NewCap;
+  }
+
+public:
+  PODSmallVector() : First(Inline), Last(First), Cap(Inline + N) {}
+
+  PODSmallVector(const PODSmallVector&) = delete;
+  PODSmallVector& operator=(const PODSmallVector&) = delete;
+
+  PODSmallVector(PODSmallVector&& Other) : PODSmallVector() {
+    if (Other.isInline()) {
+      std::copy(Other.begin(), Other.end(), First);
+      Last = First + Other.size();
+      Other.clear();
+      return;
+    }
+
+    First = Other.First;
+    Last = Other.Last;
+    Cap = Other.Cap;
+    Other.clearInline();
+  }
+
+  PODSmallVector& operator=(PODSmallVector&& Other) {
+    if (Other.isInline()) {
+      if (!isInline()) {
+        std::free(First);
+        clearInline();
+      }
+      std::copy(Other.begin(), Other.end(), First);
+      Last = First + Other.size();
+      Other.clear();
+      return *this;
+    }
+
+    if (isInline()) {
+      First = Other.First;
+      Last = Other.Last;
+      Cap = Other.Cap;
+      Other.clearInline();
+      return *this;
+    }
+
+    std::swap(First, Other.First);
+    std::swap(Last, Other.Last);
+    std::swap(Cap, Other.Cap);
+    Other.clear();
+    return *this;
+  }
+
+  void push_back(const T& Elem) {
+    if (Last == Cap)
+      reserve(size() * 2);
+    *Last++ = Elem;
+  }
+
+  void pop_back() {
+    assert(Last != First && "Popping empty vector!");
+    --Last;
+  }
+
+  void dropBack(size_t Index) {
+    assert(Index <= size() && "dropBack() can't expand!");
+    Last = First + Index;
+  }
+
+  T* begin() { return First; }
+  T* end() { return Last; }
+
+  bool empty() const { return First == Last; }
+  size_t size() const { return static_cast<size_t>(Last - First); }
+  T& back() {
+    assert(Last != First && "Calling back() on empty vector!");
+    return *(Last - 1);
+  }
+  T& operator[](size_t Index) {
+    assert(Index < size() && "Invalid access!");
+    return *(begin() + Index);
+  }
+  void clear() { Last = First; }
+
+  ~PODSmallVector() {
+    if (!isInline())
+      std::free(First);
+  }
+};
+
+// Substitution table. This type is used to track the substitutions that are
+// known by the parser.
+template <size_t Size>
+class SubstitutionTable {
+  // Substitutions hold the actual entries in the table, and PackIndices tells
+  // us which entries are members of which pack. For example, if the
+  // substitutions we're tracking are: {int, {float, FooBar}, char}, with
+  // {float, FooBar} being a parameter pack, we represent the substitutions as:
+  // Substitutions: int, float, FooBar, char
+  // PackIndices:     0,             1,    3
+  // So, PackIndicies[I] holds the offset of the begin of the Ith pack, and
+  // PackIndices[I + 1] holds the offset of the end.
+  PODSmallVector<Node*, Size> Substitutions;
+  PODSmallVector<unsigned, Size> PackIndices;
+
+public:
+  // Add a substitution that represents a single name to the table. This is
+  // modeled as a parameter pack with just one element.
+  void pushSubstitution(Node* Entry) {
+    pushPack();
+    pushSubstitutionIntoPack(Entry);
+  }
+
+  // Add a new empty pack to the table. Subsequent calls to
+  // pushSubstitutionIntoPack() will add to this pack.
+  void pushPack() {
+    PackIndices.push_back(static_cast<unsigned>(Substitutions.size()));
+  }
+  void pushSubstitutionIntoPack(Node* Entry) {
+    assert(!PackIndices.empty() && "No pack to push substitution into!");
+    Substitutions.push_back(Entry);
+  }
+
+  // Remove the last pack from the table.
+  void popPack() {
+    unsigned Last = PackIndices.back();
+    PackIndices.pop_back();
+    Substitutions.dropBack(Last);
+  }
+
+  // For use in a range-for loop.
+  struct NodeRange {
+    Node** First;
+    Node** Last;
+    Node** begin() { return First; }
+    Node** end() { return Last; }
+  };
+
+  // Retrieve the Nth substitution. This is represented as a range, as the
+  // substitution could be referring to a parameter pack.
+  NodeRange nthSubstitution(size_t N) {
+    assert(PackIndices[N] <= Substitutions.size());
+    // The Nth parameter pack starts at offset PackIndices[N], and ends at
+    // PackIndices[N + 1].
+    Node** Begin = Substitutions.begin() + PackIndices[N];
+    Node** End;
+    if (N + 1 != PackIndices.size()) {
+      assert(PackIndices[N + 1] <= Substitutions.size());
+      End = Substitutions.begin() + PackIndices[N + 1];
+    } else
+      End = Substitutions.end();
+    assert(Begin <= End);
+    return NodeRange{Begin, End};
+  }
+
+  size_t size() const { return PackIndices.size(); }
+  bool empty() const { return PackIndices.empty(); }
+  void clear() {
+    Substitutions.clear();
+    PackIndices.clear();
+  }
+};
+
+struct Db
 {
-    fprintf(stderr, "---------\n");
-    fprintf(stderr, "names:\n");
-    for (auto& s : db.names)
-        fprintf(stderr, "{%s#%s}\n", s.first.c_str(), s.second.c_str());
-    int i = -1;
-    fprintf(stderr, "subs:\n");
-    for (auto& v : db.subs)
+    // Name stack, this is used by the parser to hold temporary names that were
+    // parsed. The parser colapses multiple names into new nodes to construct
+    // the AST. Once the parser is finished, names.size() == 1.
+    PODSmallVector<Node*, 32> Names;
+
+    // Substitution table. Itanium supports name substitutions as a means of
+    // compression. The string "S42_" refers to the 42nd entry in this table.
+    SubstitutionTable<32> Subs;
+
+    // Template parameter table. Like the above, but referenced like "T42_".
+    // This has a smaller size compared to Subs and Names because it can be
+    // stored on the stack.
+    SubstitutionTable<4> TemplateParams;
+
+    Qualifiers CV = QualNone;
+    FunctionRefQual RefQuals = FrefQualNone;
+    unsigned EncodingDepth = 0;
+    bool ParsedCtorDtorCV = false;
+    bool TagTemplates = true;
+    bool FixForwardReferences = false;
+    bool TryToParseTemplateArgs = true;
+
+    BumpPointerAllocator ASTAllocator;
+
+    template <class T, class... Args> T* make(Args&& ...args)
     {
-        if (i >= 0)
-            fprintf(stderr, "S%i_ = {", i);
-        else
-            fprintf(stderr, "S_  = {");
-        for (auto& s : v)
-            fprintf(stderr, "{%s#%s}", s.first.c_str(), s.second.c_str());
-        fprintf(stderr, "}\n");
-        ++i;
+        return new (ASTAllocator.allocate(sizeof(T)))
+            T(std::forward<Args>(args)...);
     }
-    fprintf(stderr, "template_param:\n");
-    for (auto& t : db.template_param)
+
+    template <class It> NodeArray makeNodeArray(It begin, It end)
     {
-        fprintf(stderr, "--\n");
-        i = -1;
-        for (auto& v : t)
-        {
-            if (i >= 0)
-                fprintf(stderr, "T%i_ = {", i);
-            else
-                fprintf(stderr, "T_  = {");
-            for (auto& s : v)
-                fprintf(stderr, "{%s#%s}", s.first.c_str(), s.second.c_str());
-            fprintf(stderr, "}\n");
-            ++i;
-        }
+        size_t sz = static_cast<size_t>(end - begin);
+        void* mem = ASTAllocator.allocate(sizeof(Node*) * sz);
+        Node** data = new (mem) Node*[sz];
+        std::copy(begin, end, data);
+        return NodeArray(data, sz);
     }
-    fprintf(stderr, "---------\n\n");
-}
 
-template <class C>
-void
-print_state(const char* msg, const char* first, const char* last, const C& db)
-{
-    fprintf(stderr, "%s: ", msg);
-    for (; first != last; ++first)
-        fprintf(stderr, "%c", *first);
-    fprintf(stderr, "\n");
-    print_stack(db);
-}
+    NodeArray popTrailingNodeArray(size_t FromPosition)
+    {
+        assert(FromPosition <= Names.size());
+        NodeArray res = makeNodeArray(
+            Names.begin() + (long)FromPosition, Names.end());
+        Names.dropBack(FromPosition);
+        return res;
+    }
+};
+
+const char* parse_type(const char* first, const char* last, Db& db);
+const char* parse_encoding(const char* first, const char* last, Db& db);
+const char* parse_name(const char* first, const char* last, Db& db,
+                       bool* ends_with_template_args = 0);
+const char* parse_expression(const char* first, const char* last, Db& db);
+const char* parse_template_args(const char* first, const char* last, Db& db);
+const char* parse_operator_name(const char* first, const char* last, Db& db);
+const char* parse_unqualified_name(const char* first, const char* last, Db& db);
+const char* parse_decltype(const char* first, const char* last, Db& db);
 
 // <number> ::= [n] <non-negative decimal integer>
 
@@ -140,30 +1755,30 @@ parse_number(const char* first, const char* last)
 }
 
 template <class Float>
-struct float_data;
+struct FloatData;
 
 template <>
-struct float_data<float>
+struct FloatData<float>
 {
     static const size_t mangled_size = 8;
     static const size_t max_demangled_size = 24;
     static constexpr const char* spec = "%af";
 };
 
-constexpr const char* float_data<float>::spec;
+constexpr const char* FloatData<float>::spec;
 
 template <>
-struct float_data<double>
+struct FloatData<double>
 {
     static const size_t mangled_size = 16;
     static const size_t max_demangled_size = 32;
     static constexpr const char* spec = "%a";
 };
 
-constexpr const char* float_data<double>::spec;
+constexpr const char* FloatData<double>::spec;
 
 template <>
-struct float_data<long double>
+struct FloatData<long double>
 {
 #if defined(__mips__) && defined(__mips_n64) || defined(__aarch64__) || \
     defined(__wasm__)
@@ -177,55 +1792,34 @@ struct float_data<long double>
     static constexpr const char* spec = "%LaL";
 };
 
-constexpr const char* float_data<long double>::spec;
+constexpr const char* FloatData<long double>::spec;
 
-template <class Float, class C>
+template <class Float>
 const char*
-parse_floating_number(const char* first, const char* last, C& db)
+parse_floating_number(const char* first, const char* last, Db& db)
 {
-    const size_t N = float_data<Float>::mangled_size;
-    if (static_cast<std::size_t>(last - first) > N)
+    const size_t N = FloatData<Float>::mangled_size;
+    if (static_cast<std::size_t>(last - first) <= N)
+        return first;
+    last = first + N;
+    const char* t = first;
+    for (; t != last; ++t)
     {
-        last = first + N;
-        union
-        {
-            Float value;
-            char buf[sizeof(Float)];
-        };
-        const char* t = first;
-        char* e = buf;
-        for (; t != last; ++t, ++e)
-        {
-            if (!isxdigit(*t))
-                return first;
-            unsigned d1 = isdigit(*t) ? static_cast<unsigned>(*t - '0') :
-                                        static_cast<unsigned>(*t - 'a' + 10);
-            ++t;
-            unsigned d0 = isdigit(*t) ? static_cast<unsigned>(*t - '0') :
-                                        static_cast<unsigned>(*t - 'a' + 10);
-            *e = static_cast<char>((d1 << 4) + d0);
-        }
-        if (*t == 'E')
-        {
-#if __BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__
-            std::reverse(buf, e);
-#endif
-            char num[float_data<Float>::max_demangled_size] = {0};
-            int n = snprintf(num, sizeof(num), float_data<Float>::spec, value);
-            if (static_cast<std::size_t>(n) >= sizeof(num))
-                return first;
-            db.names.push_back(typename C::String(num, static_cast<std::size_t>(n)));
-            first = t+1;
-        }
+        if (!isxdigit(*t))
+            return first;
+    }
+    if (*t == 'E')
+    {
+        db.Names.push_back(
+            db.make<FloatExpr<Float>>(StringView(first, t)));
+        first = t + 1;
     }
     return first;
 }
 
-// <source-name> ::= <positive length number> <identifier>
-
-template <class C>
+// <positive length number> ::= [0-9]*
 const char*
-parse_source_name(const char* first, const char* last, C& db)
+parse_positive_integer(const char* first, const char* last, size_t* out)
 {
     if (first != last)
     {
@@ -240,15 +1834,53 @@ parse_source_name(const char* first, const char* last, C& db)
                 if (++t == last)
                     return first;
             }
-            if (static_cast<size_t>(last - t) >= n)
-            {
-                typename C::String r(t, n);
-                if (r.substr(0, 10) == "_GLOBAL__N")
-                    db.names.push_back("(anonymous namespace)");
-                else
-                    db.names.push_back(std::move(r));
-                first = t + n;
-            }
+            *out = n;
+            first = t;
+        }
+    }
+    return first;
+}
+
+// extension
+// <abi-tag-seq> ::= <abi-tag>*
+// <abi-tag>     ::= B <positive length number> <identifier>
+const char*
+parse_abi_tag_seq(const char* first, const char* last, Db& db)
+{
+    while (first != last && *first == 'B' && first+1 != last)
+    {
+        size_t length;
+        const char* t = parse_positive_integer(first+1, last, &length);
+        if (t == first+1)
+            return first;
+        if (static_cast<size_t>(last - t) < length || db.Names.empty())
+            return first;
+        db.Names.back() = db.make<AbiTagAttr>(
+            db.Names.back(), StringView(t, t + length));
+        first = t + length;
+    }
+    return first;
+}
+
+// <source-name> ::= <positive length number> <identifier> [<abi-tag-seq>]
+const char*
+parse_source_name(const char* first, const char* last, Db& db)
+{
+    if (first != last)
+    {
+        size_t length;
+        const char* t = parse_positive_integer(first, last, &length);
+        if (t == first)
+            return first;
+        if (static_cast<size_t>(last - t) >= length)
+        {
+            StringView r(t, t + length);
+            if (r.substr(0, 10) == "_GLOBAL__N")
+                db.Names.push_back(db.make<NameType>("(anonymous namespace)"));
+            else
+                db.Names.push_back(db.make<NameType>(r));
+            first = t + length;
+            first = parse_abi_tag_seq(first, last, db);
         }
     }
     return first;
@@ -265,9 +1897,8 @@ parse_source_name(const char* first, const char* last, C& db)
 // <substitution> ::= So # ::std::basic_ostream<char,  std::char_traits<char> >
 // <substitution> ::= Sd # ::std::basic_iostream<char, std::char_traits<char> >
 
-template <class C>
 const char*
-parse_substitution(const char* first, const char* last, C& db)
+parse_substitution(const char* first, const char* last, Db& db)
 {
     if (last - first >= 2)
     {
@@ -276,34 +1907,39 @@ parse_substitution(const char* first, const char* last, C& db)
             switch (first[1])
             {
             case 'a':
-                db.names.push_back("std::allocator");
+                db.Names.push_back(
+                    db.make<SpecialSubstitution>(
+                        SpecialSubKind::allocator));
                 first += 2;
                 break;
             case 'b':
-                db.names.push_back("std::basic_string");
+                db.Names.push_back(
+                    db.make<SpecialSubstitution>(SpecialSubKind::basic_string));
                 first += 2;
                 break;
             case 's':
-                db.names.push_back("std::string");
+                db.Names.push_back(
+                    db.make<SpecialSubstitution>(
+                        SpecialSubKind::string));
                 first += 2;
                 break;
             case 'i':
-                db.names.push_back("std::istream");
+                db.Names.push_back(db.make<SpecialSubstitution>(SpecialSubKind::istream));
                 first += 2;
                 break;
             case 'o':
-                db.names.push_back("std::ostream");
+                db.Names.push_back(db.make<SpecialSubstitution>(SpecialSubKind::ostream));
                 first += 2;
                 break;
             case 'd':
-                db.names.push_back("std::iostream");
+                db.Names.push_back(db.make<SpecialSubstitution>(SpecialSubKind::iostream));
                 first += 2;
                 break;
             case '_':
-                if (!db.subs.empty())
+                if (!db.Subs.empty())
                 {
-                    for (const auto& n : db.subs.front())
-                        db.names.push_back(n);
+                    for (Node* n : db.Subs.nthSubstitution(0))
+                        db.Names.push_back(n);
                     first += 2;
                 }
                 break;
@@ -327,10 +1963,10 @@ parse_substitution(const char* first, const char* last, C& db)
                     if (t == last || *t != '_')
                         return first;
                     ++sub;
-                    if (sub < db.subs.size())
+                    if (sub < db.Subs.size())
                     {
-                        for (const auto& n : db.subs[sub])
-                            db.names.push_back(n);
+                        for (Node* n : db.Subs.nthSubstitution(sub))
+                            db.Names.push_back(n);
                         first = t+1;
                     }
                 }
@@ -373,96 +2009,95 @@ parse_substitution(const char* first, const char* last, C& db)
 //                ::= Dn   # std::nullptr_t (i.e., decltype(nullptr))
 //                ::= u <source-name>    # vendor extended type
 
-template <class C>
 const char*
-parse_builtin_type(const char* first, const char* last, C& db)
+parse_builtin_type(const char* first, const char* last, Db& db)
 {
     if (first != last)
     {
         switch (*first)
         {
         case 'v':
-            db.names.push_back("void");
+            db.Names.push_back(db.make<NameType>("void"));
             ++first;
             break;
         case 'w':
-            db.names.push_back("wchar_t");
+            db.Names.push_back(db.make<NameType>("wchar_t"));
             ++first;
             break;
         case 'b':
-            db.names.push_back("bool");
+            db.Names.push_back(db.make<NameType>("bool"));
             ++first;
             break;
         case 'c':
-            db.names.push_back("char");
+            db.Names.push_back(db.make<NameType>("char"));
             ++first;
             break;
         case 'a':
-            db.names.push_back("signed char");
+            db.Names.push_back(db.make<NameType>("signed char"));
             ++first;
             break;
         case 'h':
-            db.names.push_back("unsigned char");
+            db.Names.push_back(db.make<NameType>("unsigned char"));
             ++first;
             break;
         case 's':
-            db.names.push_back("short");
+            db.Names.push_back(db.make<NameType>("short"));
             ++first;
             break;
         case 't':
-            db.names.push_back("unsigned short");
+            db.Names.push_back(db.make<NameType>("unsigned short"));
             ++first;
             break;
         case 'i':
-            db.names.push_back("int");
+            db.Names.push_back(db.make<NameType>("int"));
             ++first;
             break;
         case 'j':
-            db.names.push_back("unsigned int");
+            db.Names.push_back(db.make<NameType>("unsigned int"));
             ++first;
             break;
         case 'l':
-            db.names.push_back("long");
+            db.Names.push_back(db.make<NameType>("long"));
             ++first;
             break;
         case 'm':
-            db.names.push_back("unsigned long");
+            db.Names.push_back(db.make<NameType>("unsigned long"));
             ++first;
             break;
         case 'x':
-            db.names.push_back("long long");
+            db.Names.push_back(db.make<NameType>("long long"));
             ++first;
             break;
         case 'y':
-            db.names.push_back("unsigned long long");
+            db.Names.push_back(db.make<NameType>("unsigned long long"));
             ++first;
             break;
         case 'n':
-            db.names.push_back("__int128");
+            db.Names.push_back(db.make<NameType>("__int128"));
             ++first;
             break;
         case 'o':
-            db.names.push_back("unsigned __int128");
+            db.Names.push_back(db.make<NameType>("unsigned __int128"));
             ++first;
             break;
         case 'f':
-            db.names.push_back("float");
+            db.Names.push_back(db.make<NameType>("float"));
             ++first;
             break;
         case 'd':
-            db.names.push_back("double");
+            db.Names.push_back(db.make<NameType>("double"));
             ++first;
             break;
         case 'e':
-            db.names.push_back("long double");
+            db.Names.push_back(db.make<NameType>("long double"));
             ++first;
             break;
         case 'g':
-            db.names.push_back("__float128");
+            db.Names.push_back(db.make<NameType>("__float128"));
             ++first;
             break;
         case 'z':
-            db.names.push_back("...");
+            db.Names.push_back(db.make<NameType>("..."));
             ++first;
             break;
         case 'u':
@@ -478,39 +2113,39 @@ parse_builtin_type(const char* first, const char* last, C& db)
                 switch (first[1])
                 {
                 case 'd':
-                    db.names.push_back("decimal64");
+                    db.Names.push_back(db.make<NameType>("decimal64"));
                     first += 2;
                     break;
                 case 'e':
-                    db.names.push_back("decimal128");
+                    db.Names.push_back(db.make<NameType>("decimal128"));
                     first += 2;
                     break;
                 case 'f':
-                    db.names.push_back("decimal32");
+                    db.Names.push_back(db.make<NameType>("decimal32"));
                     first += 2;
                     break;
                 case 'h':
-                    db.names.push_back("decimal16");
+                    db.Names.push_back(db.make<NameType>("decimal16"));
                     first += 2;
                     break;
                 case 'i':
-                    db.names.push_back("char32_t");
+                    db.Names.push_back(db.make<NameType>("char32_t"));
                     first += 2;
                     break;
                 case 's':
-                    db.names.push_back("char16_t");
+                    db.Names.push_back(db.make<NameType>("char16_t"));
                     first += 2;
                     break;
                 case 'a':
-                    db.names.push_back("auto");
+                    db.Names.push_back(db.make<NameType>("auto"));
                     first += 2;
                     break;
                 case 'c':
-                    db.names.push_back("decltype(auto)");
+                    db.Names.push_back(db.make<NameType>("decltype(auto)"));
                     first += 2;
                     break;
                 case 'n':
-                    db.names.push_back("std::nullptr_t");
+                    db.Names.push_back(db.make<NameType>("std::nullptr_t"));
                     first += 2;
                     break;
                 }
@@ -521,27 +2156,27 @@ parse_builtin_type(const char* first, const char* last, C& db)
     return first;
 }
 
-// <CV-qualifiers> ::= [r] [V] [K]
+// <CV-Qualifiers> ::= [r] [V] [K]
 
 const char*
-parse_cv_qualifiers(const char* first, const char* last, unsigned& cv)
+parse_cv_qualifiers(const char* first, const char* last, Qualifiers& cv)
 {
-    cv = 0;
+    cv = QualNone;
     if (first != last)
     {
         if (*first == 'r')
         {
-            cv |= 4;
+            addQualifiers(cv, QualRestrict);
             ++first;
         }
         if (*first == 'V')
         {
-            cv |= 2;
+            addQualifiers(cv, QualVolatile);
             ++first;
         }
         if (*first == 'K')
         {
-            cv |= 1;
+            addQualifiers(cv, QualConst);
             ++first;
         }
     }
@@ -551,9 +2186,8 @@ parse_cv_qualifiers(const char* first, const char* last, unsigned& cv)
 // <template-param> ::= T_    # first template parameter
 //                  ::= T <parameter-2 non-negative number> _
 
-template <class C>
 const char*
-parse_template_param(const char* first, const char* last, C& db)
+parse_template_param(const char* first, const char* last, Db& db)
 {
     if (last - first >= 2)
     {
@@ -561,19 +2195,17 @@ parse_template_param(const char* first, const char* last, C& db)
         {
             if (first[1] == '_')
             {
-                if (db.template_param.empty())
-                    return first;
-                if (!db.template_param.back().empty())
+                if (!db.TemplateParams.empty())
                 {
-                    for (auto& t : db.template_param.back().front())
-                        db.names.push_back(t);
+                    for (Node *t : db.TemplateParams.nthSubstitution(0))
+                        db.Names.push_back(t);
                     first += 2;
                 }
                 else
                 {
-                    db.names.push_back("T_");
+                    db.Names.push_back(db.make<NameType>("T_"));
                     first += 2;
-                    db.fix_forward_references = true;
+                    db.FixForwardReferences = true;
                 }
             }
             else if (isdigit(first[1]))
@@ -585,20 +2217,21 @@ parse_template_param(const char* first, const char* last, C& db)
                     sub *= 10;
                     sub += static_cast<size_t>(*t - '0');
                 }
-                if (t == last || *t != '_' || db.template_param.empty())
+                if (t == last || *t != '_')
                     return first;
                 ++sub;
-                if (sub < db.template_param.back().size())
+                if (sub < db.TemplateParams.size())
                 {
-                    for (auto& temp : db.template_param.back()[sub])
-                        db.names.push_back(temp);
+                    for (Node *temp : db.TemplateParams.nthSubstitution(sub))
+                        db.Names.push_back(temp);
                     first = t+1;
                 }
                 else
                 {
-                    db.names.push_back(typename C::String(first, t+1));
+                    db.Names.push_back(
+                        db.make<NameType>(StringView(first, t + 1)));
                     first = t+1;
-                    db.fix_forward_references = true;
+                    db.FixForwardReferences = true;
                 }
             }
         }
@@ -608,9 +2241,8 @@ parse_template_param(const char* first, const char* last, C& db)
 
 // cc <type> <expression>                               # const_cast<type> (expression)
 
-template <class C>
 const char*
-parse_const_cast_expr(const char* first, const char* last, C& db)
+parse_const_cast_expr(const char* first, const char* last, Db& db)
 {
     if (last - first >= 3 && first[0] == 'c' && first[1] == 'c')
     {
@@ -620,13 +2252,14 @@ parse_const_cast_expr(const char* first, const char* last, C& db)
             const char* t1 = parse_expression(t, last, db);
             if (t1 != t)
             {
-                if (db.names.size() < 2)
+                if (db.Names.size() < 2)
                     return first;
-                auto expr = db.names.back().move_full();
-                db.names.pop_back();
-                if (db.names.empty())
+                auto from_expr = db.Names.back();
+                db.Names.pop_back();
+                if (db.Names.empty())
                     return first;
-                db.names.back() = "const_cast<" + db.names.back().move_full() + ">(" + expr + ")";
+                db.Names.back() = db.make<CastExpr>(
+                    "const_cast", db.Names.back(), from_expr);
                 first = t1;
             }
         }
@@ -636,9 +2269,8 @@ parse_const_cast_expr(const char* first, const char* last, C& db)
 
 // dc <type> <expression>                               # dynamic_cast<type> (expression)
 
-template <class C>
 const char*
-parse_dynamic_cast_expr(const char* first, const char* last, C& db)
+parse_dynamic_cast_expr(const char* first, const char* last, Db& db)
 {
     if (last - first >= 3 && first[0] == 'd' && first[1] == 'c')
     {
@@ -648,13 +2280,14 @@ parse_dynamic_cast_expr(const char* first, const char* last, C& db)
             const char* t1 = parse_expression(t, last, db);
             if (t1 != t)
             {
-                if (db.names.size() < 2)
+                if (db.Names.size() < 2)
                     return first;
-                auto expr = db.names.back().move_full();
-                db.names.pop_back();
-                if (db.names.empty())
+                auto from_expr = db.Names.back();
+                db.Names.pop_back();
+                if (db.Names.empty())
                     return first;
-                db.names.back() = "dynamic_cast<" + db.names.back().move_full() + ">(" + expr + ")";
+                db.Names.back() = db.make<CastExpr>(
+                    "dynamic_cast", db.Names.back(), from_expr);
                 first = t1;
             }
         }
@@ -664,9 +2297,8 @@ parse_dynamic_cast_expr(const char* first, const char* last, C& db)
 
 // rc <type> <expression>                               # reinterpret_cast<type> (expression)
 
-template <class C>
 const char*
-parse_reinterpret_cast_expr(const char* first, const char* last, C& db)
+parse_reinterpret_cast_expr(const char* first, const char* last, Db& db)
 {
     if (last - first >= 3 && first[0] == 'r' && first[1] == 'c')
     {
@@ -676,13 +2308,14 @@ parse_reinterpret_cast_expr(const char* first, const char* last, C& db)
             const char* t1 = parse_expression(t, last, db);
             if (t1 != t)
             {
-                if (db.names.size() < 2)
+                if (db.Names.size() < 2)
                     return first;
-                auto expr = db.names.back().move_full();
-                db.names.pop_back();
-                if (db.names.empty())
+                auto from_expr = db.Names.back();
+                db.Names.pop_back();
+                if (db.Names.empty())
                     return first;
-                db.names.back() = "reinterpret_cast<" + db.names.back().move_full() + ">(" + expr + ")";
+                db.Names.back() = db.make<CastExpr>(
+                    "reinterpret_cast", db.Names.back(), from_expr);
                 first = t1;
             }
         }
@@ -692,9 +2325,8 @@ parse_reinterpret_cast_expr(const char* first, const char* last, C& db)
 
 // sc <type> <expression>                               # static_cast<type> (expression)
 
-template <class C>
 const char*
-parse_static_cast_expr(const char* first, const char* last, C& db)
+parse_static_cast_expr(const char* first, const char* last, Db& db)
 {
     if (last - first >= 3 && first[0] == 's' && first[1] == 'c')
     {
@@ -704,11 +2336,12 @@ parse_static_cast_expr(const char* first, const char* last, C& db)
             const char* t1 = parse_expression(t, last, db);
             if (t1 != t)
             {
-                if (db.names.size() < 2)
+                if (db.Names.size() < 2)
                     return first;
-                auto expr = db.names.back().move_full();
-                db.names.pop_back();
-                db.names.back() = "static_cast<" + db.names.back().move_full() + ">(" + expr + ")";
+                auto from_expr = db.Names.back();
+                db.Names.pop_back();
+                db.Names.back() = db.make<CastExpr>(
+                    "static_cast", db.Names.back(), from_expr);
                 first = t1;
             }
         }
@@ -718,9 +2351,8 @@ parse_static_cast_expr(const char* first, const char* last, C& db)
 
 // sp <expression>                                  # pack expansion
 
-template <class C>
 const char*
-parse_pack_expansion(const char* first, const char* last, C& db)
+parse_pack_expansion(const char* first, const char* last, Db& db)
 {
     if (last - first >= 3 && first[0] == 's' && first[1] == 'p')
     {
@@ -733,18 +2365,18 @@ parse_pack_expansion(const char* first, const char* last, C& db)
 
 // st <type>                                            # sizeof (a type)
 
-template <class C>
 const char*
-parse_sizeof_type_expr(const char* first, const char* last, C& db)
+parse_sizeof_type_expr(const char* first, const char* last, Db& db)
 {
     if (last - first >= 3 && first[0] == 's' && first[1] == 't')
     {
         const char* t = parse_type(first+2, last, db);
         if (t != first+2)
         {
-            if (db.names.empty())
+            if (db.Names.empty())
                 return first;
-            db.names.back() = "sizeof (" + db.names.back().move_full() + ")";
+            db.Names.back() = db.make<EnclosingExpr>(
+                "sizeof (", db.Names.back(), ")");
             first = t;
         }
     }
@@ -753,18 +2385,18 @@ parse_sizeof_type_expr(const char* first, const char* last, C& db)
 
 // sz <expr>                                            # sizeof (a expression)
 
-template <class C>
 const char*
-parse_sizeof_expr_expr(const char* first, const char* last, C& db)
+parse_sizeof_expr_expr(const char* first, const char* last, Db& db)
 {
     if (last - first >= 3 && first[0] == 's' && first[1] == 'z')
     {
         const char* t = parse_expression(first+2, last, db);
         if (t != first+2)
         {
-            if (db.names.empty())
+            if (db.Names.empty())
                 return first;
-            db.names.back() = "sizeof (" + db.names.back().move_full() + ")";
+            db.Names.back() = db.make<EnclosingExpr>(
+                "sizeof (", db.Names.back(), ")");
             first = t;
         }
     }
@@ -773,60 +2405,50 @@ parse_sizeof_expr_expr(const char* first, const char* last, C& db)
 
 // sZ <template-param>                                  # size of a parameter pack
 
-template <class C>
 const char*
-parse_sizeof_param_pack_expr(const char* first, const char* last, C& db)
+parse_sizeof_param_pack_expr(const char* first, const char* last, Db& db)
 {
     if (last - first >= 3 && first[0] == 's' && first[1] == 'Z' && first[2] == 'T')
     {
-        size_t k0 = db.names.size();
+        size_t k0 = db.Names.size();
         const char* t = parse_template_param(first+2, last, db);
-        size_t k1 = db.names.size();
-        if (t != first+2)
+        size_t k1 = db.Names.size();
+        if (t != first+2 && k0 <= k1)
         {
-            typename C::String tmp("sizeof...(");
-            size_t k = k0;
-            if (k != k1)
-            {
-                tmp += db.names[k].move_full();
-                for (++k; k != k1; ++k)
-                    tmp += ", " + db.names[k].move_full();
-            }
-            tmp += ")";
-            for (; k1 != k0; --k1)
-                db.names.pop_back();
-            db.names.push_back(std::move(tmp));
+            Node* sizeof_expr = db.make<SizeofParamPackExpr>(
+                db.popTrailingNodeArray(k0));
+            db.Names.push_back(sizeof_expr);
             first = t;
         }
     }
     return first;
 }
 
-// <function-param> ::= fp <top-level CV-qualifiers> _                                     # L == 0, first parameter
-//                  ::= fp <top-level CV-qualifiers> <parameter-2 non-negative number> _   # L == 0, second and later parameters
-//                  ::= fL <L-1 non-negative number> p <top-level CV-qualifiers> _         # L > 0, first parameter
-//                  ::= fL <L-1 non-negative number> p <top-level CV-qualifiers> <parameter-2 non-negative number> _   # L > 0, second and later parameters
+// <function-param> ::= fp <top-level CV-Qualifiers> _                                     # L == 0, first parameter
+//                  ::= fp <top-level CV-Qualifiers> <parameter-2 non-negative number> _   # L == 0, second and later parameters
+//                  ::= fL <L-1 non-negative number> p <top-level CV-Qualifiers> _         # L > 0, first parameter
+//                  ::= fL <L-1 non-negative number> p <top-level CV-Qualifiers> <parameter-2 non-negative number> _   # L > 0, second and later parameters
 
-template <class C>
 const char*
-parse_function_param(const char* first, const char* last, C& db)
+parse_function_param(const char* first, const char* last, Db& db)
 {
     if (last - first >= 3 && *first == 'f')
     {
         if (first[1] == 'p')
         {
-            unsigned cv;
+            Qualifiers cv;
             const char* t = parse_cv_qualifiers(first+2, last, cv);
             const char* t1 = parse_number(t, last);
             if (t1 != last && *t1 == '_')
             {
-                db.names.push_back("fp" + typename C::String(t, t1));
+                db.Names.push_back(
+                    db.make<FunctionParam>(StringView(t, t1)));
                 first = t1+1;
             }
         }
         else if (first[1] == 'L')
         {
-            unsigned cv;
+            Qualifiers cv;
             const char* t0 = parse_number(first+2, last);
             if (t0 != last && *t0 == 'p')
             {
@@ -835,7 +2457,8 @@ parse_function_param(const char* first, const char* last, C& db)
                 const char* t1 = parse_number(t, last);
                 if (t1 != last && *t1 == '_')
                 {
-                    db.names.push_back("fp" + typename C::String(t, t1));
+                    db.Names.push_back(
+                        db.make<FunctionParam>(StringView(t, t1)));
                     first = t1+1;
                 }
             }
@@ -846,18 +2469,18 @@ parse_function_param(const char* first, const char* last, C& db)
 
 // sZ <function-param>                                  # size of a function parameter pack
 
-template <class C>
 const char*
-parse_sizeof_function_param_pack_expr(const char* first, const char* last, C& db)
+parse_sizeof_function_param_pack_expr(const char* first, const char* last, Db& db)
 {
     if (last - first >= 3 && first[0] == 's' && first[1] == 'Z' && first[2] == 'f')
     {
         const char* t = parse_function_param(first+2, last, db);
         if (t != first+2)
         {
-            if (db.names.empty())
+            if (db.Names.empty())
                 return first;
-            db.names.back() = "sizeof...(" + db.names.back().move_full() + ")";
+            db.Names.back() = db.make<EnclosingExpr>(
+                "sizeof...(", db.Names.back(), ")");
             first = t;
         }
     }
@@ -867,9 +2490,8 @@ parse_sizeof_function_param_pack_expr(const char* first, const char* last, C& db
 // te <expression>                                      # typeid (expression)
 // ti <type>                                            # typeid (type)
 
-template <class C>
 const char*
-parse_typeid_expr(const char* first, const char* last, C& db)
+parse_typeid_expr(const char* first, const char* last, Db& db)
 {
     if (last - first >= 3 && first[0] == 't' && (first[1] == 'e' || first[1] == 'i'))
     {
@@ -880,9 +2502,10 @@ parse_typeid_expr(const char* first, const char* last, C& db)
             t = parse_type(first+2, last, db);
         if (t != first+2)
         {
-            if (db.names.empty())
+            if (db.Names.empty())
                 return first;
-            db.names.back() = "typeid(" + db.names.back().move_full() + ")";
+            db.Names.back() = db.make<EnclosingExpr>(
+                "typeid(", db.Names.back(), ")");
             first = t;
         }
     }
@@ -891,18 +2514,17 @@ parse_typeid_expr(const char* first, const char* last, C& db)
 
 // tw <expression>                                      # throw expression
 
-template <class C>
 const char*
-parse_throw_expr(const char* first, const char* last, C& db)
+parse_throw_expr(const char* first, const char* last, Db& db)
 {
     if (last - first >= 3 && first[0] == 't' && first[1] == 'w')
     {
         const char* t = parse_expression(first+2, last, db);
         if (t != first+2)
         {
-            if (db.names.empty())
+            if (db.Names.empty())
                 return first;
-            db.names.back() = "throw " + db.names.back().move_full();
+            db.Names.back() = db.make<ThrowExpr>(db.Names.back());
             first = t;
         }
     }
@@ -911,9 +2533,8 @@ parse_throw_expr(const char* first, const char* last, C& db)
 
 // ds <expression> <expression>                         # expr.*expr
 
-template <class C>
 const char*
-parse_dot_star_expr(const char* first, const char* last, C& db)
+parse_dot_star_expr(const char* first, const char* last, Db& db)
 {
     if (last - first >= 3 && first[0] == 'd' && first[1] == 's')
     {
@@ -923,11 +2544,12 @@ parse_dot_star_expr(const char* first, const char* last, C& db)
             const char* t1 = parse_expression(t, last, db);
             if (t1 != t)
             {
-                if (db.names.size() < 2)
+                if (db.Names.size() < 2)
                     return first;
-                auto expr = db.names.back().move_full();
-                db.names.pop_back();
-                db.names.back().first += ".*" + expr;
+                auto rhs_expr = db.Names.back();
+                db.Names.pop_back();
+                db.Names.back() = db.make<MemberExpr>(
+                    db.Names.back(), ".*", rhs_expr);
                 first = t1;
             }
         }
@@ -937,9 +2559,8 @@ parse_dot_star_expr(const char* first, const char* last, C& db)
 
 // <simple-id> ::= <source-name> [ <template-args> ]
 
-template <class C>
 const char*
-parse_simple_id(const char* first, const char* last, C& db)
+parse_simple_id(const char* first, const char* last, Db& db)
 {
     if (first != last)
     {
@@ -949,11 +2570,12 @@ parse_simple_id(const char* first, const char* last, C& db)
             const char* t1 = parse_template_args(t, last, db);
             if (t1 != t)
             {
-                if (db.names.size() < 2)
+                if (db.Names.size() < 2)
                     return first;
-                auto args = db.names.back().move_full();
-                db.names.pop_back();
-                db.names.back().first += std::move(args);
+                auto args = db.Names.back();
+                db.Names.pop_back();
+                db.Names.back() =
+                    db.make<NameWithTemplateArgs>(db.Names.back(), args);
             }
             first = t1;
         }
@@ -967,9 +2589,8 @@ parse_simple_id(const char* first, const char* last, C& db)
 //                   ::= <decltype>
 //                   ::= <substitution>
 
-template <class C>
 const char*
-parse_unresolved_type(const char* first, const char* last, C& db)
+parse_unresolved_type(const char* first, const char* last, Db& db)
 {
     if (first != last)
     {
@@ -978,18 +2599,18 @@ parse_unresolved_type(const char* first, const char* last, C& db)
         {
         case 'T':
           {
-            size_t k0 = db.names.size();
+            size_t k0 = db.Names.size();
             t = parse_template_param(first, last, db);
-            size_t k1 = db.names.size();
+            size_t k1 = db.Names.size();
             if (t != first && k1 == k0 + 1)
             {
-                db.subs.push_back(typename C::sub_type(1, db.names.back(), db.names.get_allocator()));
+                db.Subs.pushSubstitution(db.Names.back());
                 first = t;
             }
             else
             {
                 for (; k1 != k0; --k1)
-                    db.names.pop_back();
+                    db.Names.pop_back();
             }
             break;
           }
@@ -997,9 +2618,9 @@ parse_unresolved_type(const char* first, const char* last, C& db)
             t = parse_decltype(first, last, db);
             if (t != first)
             {
-                if (db.names.empty())
+                if (db.Names.empty())
                     return first;
-                db.subs.push_back(typename C::sub_type(1, db.names.back(), db.names.get_allocator()));
+                db.Subs.pushSubstitution(db.Names.back());
                 first = t;
             }
             break;
@@ -1014,10 +2635,11 @@ parse_unresolved_type(const char* first, const char* last, C& db)
                     t = parse_unqualified_name(first+2, last, db);
                     if (t != first+2)
                     {
-                        if (db.names.empty())
+                        if (db.Names.empty())
                             return first;
-                        db.names.back().first.insert(0, "std::");
-                        db.subs.push_back(typename C::sub_type(1, db.names.back(), db.names.get_allocator()));
+                        db.Names.back() =
+                            db.make<StdQualifiedName>(db.Names.back());
+                        db.Subs.pushSubstitution(db.Names.back());
                         first = t;
                     }
                 }
@@ -1031,9 +2653,8 @@ parse_unresolved_type(const char* first, const char* last, C& db)
 // <destructor-name> ::= <unresolved-type>                               # e.g., ~T or ~decltype(f())
 //                   ::= <simple-id>                                     # e.g., ~A<2*N>
 
-template <class C>
 const char*
-parse_destructor_name(const char* first, const char* last, C& db)
+parse_destructor_name(const char* first, const char* last, Db& db)
 {
     if (first != last)
     {
@@ -1042,9 +2663,9 @@ parse_destructor_name(const char* first, const char* last, C& db)
             t = parse_simple_id(first, last, db);
         if (t != first)
         {
-            if (db.names.empty())
+            if (db.Names.empty())
                 return first;
-            db.names.back().first.insert(0, "~");
+            db.Names.back() = db.make<DtorName>(db.Names.back());
             first = t;
         }
     }
@@ -1059,9 +2680,8 @@ parse_destructor_name(const char* first, const char* last, C& db)
 //                        ::= dn <destructor-name>                       # destructor or pseudo-destructor;
 //                                                                         # e.g. ~X or ~X<N-1>
 
-template <class C>
 const char*
-parse_base_unresolved_name(const char* first, const char* last, C& db)
+parse_base_unresolved_name(const char* first, const char* last, Db& db)
 {
     if (last - first >= 2)
     {
@@ -1075,11 +2695,13 @@ parse_base_unresolved_name(const char* first, const char* last, C& db)
                     first = parse_template_args(t, last, db);
                     if (first != t)
                     {
-                        if (db.names.size() < 2)
+                        if (db.Names.size() < 2)
                             return first;
-                        auto args = db.names.back().move_full();
-                        db.names.pop_back();
-                        db.names.back().first += std::move(args);
+                        auto args = db.Names.back();
+                        db.Names.pop_back();
+                        db.Names.back() =
+                            db.make<NameWithTemplateArgs>(
+                                db.Names.back(), args);
                     }
                 }
             }
@@ -1101,11 +2723,13 @@ parse_base_unresolved_name(const char* first, const char* last, C& db)
                     first = parse_template_args(t, last, db);
                     if (first != t)
                     {
-                        if (db.names.size() < 2)
+                        if (db.Names.size() < 2)
                             return first;
-                        auto args = db.names.back().move_full();
-                        db.names.pop_back();
-                        db.names.back().first += std::move(args);
+                        auto args = db.Names.back();
+                        db.Names.pop_back();
+                        db.Names.back() =
+                            db.make<NameWithTemplateArgs>(
+                                db.Names.back(), args);
                     }
                 }
             }
@@ -1118,9 +2742,8 @@ parse_base_unresolved_name(const char* first, const char* last, C& db)
 
 // <unresolved-qualifier-level> ::= <simple-id>
 
-template <class C>
 const char*
-parse_unresolved_qualifier_level(const char* first, const char* last, C& db)
+parse_unresolved_qualifier_level(const char* first, const char* last, Db& db)
 {
     return parse_simple_id(first, last, db);
 }
@@ -1135,9 +2758,8 @@ parse_unresolved_qualifier_level(const char* first, const char* last, C& db)
 //                                                                       # T::N::x /decltype(p)::N::x
 //  (ignored)        ::= srN <unresolved-type>  <unresolved-qualifier-level>+ E <base-unresolved-name>
 
-template <class C>
 const char*
-parse_unresolved_name(const char* first, const char* last, C& db)
+parse_unresolved_name(const char* first, const char* last, Db& db)
 {
     if (last - first > 2)
     {
@@ -1153,9 +2775,10 @@ parse_unresolved_name(const char* first, const char* last, C& db)
         {
             if (global)
             {
-                if (db.names.empty())
+                if (db.Names.empty())
                     return first;
-                db.names.back().first.insert(0, "::");
+                db.Names.back() =
+                    db.make<GlobalQualifiedName>(db.Names.back());
             }
             first = t2;
         }
@@ -1171,41 +2794,44 @@ parse_unresolved_name(const char* first, const char* last, C& db)
                 t1 = parse_template_args(t, last, db);
                 if (t1 != t)
                 {
-                    if (db.names.size() < 2)
+                    if (db.Names.size() < 2)
                         return first;
-                    auto args = db.names.back().move_full();
-                    db.names.pop_back();
-                    db.names.back().first += std::move(args);
+                    auto args = db.Names.back();
+                    db.Names.pop_back();
+                    db.Names.back() = db.make<NameWithTemplateArgs>(
+                        db.Names.back(), args);
                     t = t1;
                     if (t == last)
                     {
-                        db.names.pop_back();
+                        db.Names.pop_back();
                         return first;
                     }
                 }
                 while (*t != 'E')
                 {
                     t1 = parse_unresolved_qualifier_level(t, last, db);
-                    if (t1 == t || t1 == last || db.names.size() < 2)
+                    if (t1 == t || t1 == last || db.Names.size() < 2)
                         return first;
-                    auto s = db.names.back().move_full();
-                    db.names.pop_back();
-                    db.names.back().first += "::" + std::move(s);
+                    auto s = db.Names.back();
+                    db.Names.pop_back();
+                    db.Names.back() =
+                        db.make<QualifiedName>(db.Names.back(), s);
                     t = t1;
                 }
                 ++t;
                 t1 = parse_base_unresolved_name(t, last, db);
                 if (t1 == t)
                 {
-                    if (!db.names.empty())
-                        db.names.pop_back();
+                    if (!db.Names.empty())
+                        db.Names.pop_back();
                     return first;
                 }
-                if (db.names.size() < 2)
+                if (db.Names.size() < 2)
                     return first;
-                auto s = db.names.back().move_full();
-                db.names.pop_back();
-                db.names.back().first += "::" + std::move(s);
+                auto s = db.Names.back();
+                db.Names.pop_back();
+                db.Names.back() =
+                    db.make<QualifiedName>(db.Names.back(), s);
                 first = t1;
             }
             else
@@ -1218,25 +2844,28 @@ parse_unresolved_name(const char* first, const char* last, C& db)
                     t1 = parse_template_args(t, last, db);
                     if (t1 != t)
                     {
-                        if (db.names.size() < 2)
+                        if (db.Names.size() < 2)
                             return first;
-                        auto args = db.names.back().move_full();
-                        db.names.pop_back();
-                        db.names.back().first += std::move(args);
+                        auto args = db.Names.back();
+                        db.Names.pop_back();
+                        db.Names.back() =
+                            db.make<NameWithTemplateArgs>(
+                                db.Names.back(), args);
                         t = t1;
                     }
                     t1 = parse_base_unresolved_name(t, last, db);
                     if (t1 == t)
                     {
-                        if (!db.names.empty())
-                            db.names.pop_back();
+                        if (!db.Names.empty())
+                            db.Names.pop_back();
                         return first;
                     }
-                    if (db.names.size() < 2)
+                    if (db.Names.size() < 2)
                         return first;
-                    auto s = db.names.back().move_full();
-                    db.names.pop_back();
-                    db.names.back().first += "::" + std::move(s);
+                    auto s = db.Names.back();
+                    db.Names.pop_back();
+                    db.Names.back() =
+                        db.make<QualifiedName>(db.Names.back(), s);
                     first = t1;
                 }
                 else
@@ -1247,33 +2876,37 @@ parse_unresolved_name(const char* first, const char* last, C& db)
                     t = t1;
                     if (global)
                     {
-                        if (db.names.empty())
+                        if (db.Names.empty())
                             return first;
-                        db.names.back().first.insert(0, "::");
+                        db.Names.back() =
+                            db.make<GlobalQualifiedName>(
+                                db.Names.back());
                     }
                     while (*t != 'E')
                     {
                         t1 = parse_unresolved_qualifier_level(t, last, db);
-                        if (t1 == t || t1 == last || db.names.size() < 2)
+                        if (t1 == t || t1 == last || db.Names.size() < 2)
                             return first;
-                        auto s = db.names.back().move_full();
-                        db.names.pop_back();
-                        db.names.back().first += "::" + std::move(s);
+                        auto s = db.Names.back();
+                        db.Names.pop_back();
+                        db.Names.back() = db.make<QualifiedName>(
+                            db.Names.back(), s);
                         t = t1;
                     }
                     ++t;
                     t1 = parse_base_unresolved_name(t, last, db);
                     if (t1 == t)
                     {
-                        if (!db.names.empty())
-                            db.names.pop_back();
+                        if (!db.Names.empty())
+                            db.Names.pop_back();
                         return first;
                     }
-                    if (db.names.size() < 2)
+                    if (db.Names.size() < 2)
                         return first;
-                    auto s = db.names.back().move_full();
-                    db.names.pop_back();
-                    db.names.back().first += "::" + std::move(s);
+                    auto s = db.Names.back();
+                    db.Names.pop_back();
+                    db.Names.back() =
+                        db.make<QualifiedName>(db.Names.back(), s);
                     first = t1;
                 }
             }
@@ -1284,9 +2917,8 @@ parse_unresolved_name(const char* first, const char* last, C& db)
 
 // dt <expression> <unresolved-name>                    # expr.name
 
-template <class C>
 const char*
-parse_dot_expr(const char* first, const char* last, C& db)
+parse_dot_expr(const char* first, const char* last, Db& db)
 {
     if (last - first >= 3 && first[0] == 'd' && first[1] == 't')
     {
@@ -1296,13 +2928,13 @@ parse_dot_expr(const char* first, const char* last, C& db)
             const char* t1 = parse_unresolved_name(t, last, db);
             if (t1 != t)
             {
-                if (db.names.size() < 2)
+                if (db.Names.size() < 2)
                     return first;
-                auto name = db.names.back().move_full();
-                db.names.pop_back();
-                if (db.names.empty())
+                auto name = db.Names.back();
+                db.Names.pop_back();
+                if (db.Names.empty())
                     return first;
-                db.names.back().first += "." + name;
+                db.Names.back() = db.make<MemberExpr>(db.Names.back(), ".", name);
                 first = t1;
             }
         }
@@ -1312,51 +2944,31 @@ parse_dot_expr(const char* first, const char* last, C& db)
 
 // cl <expression>+ E                                   # call
 
-template <class C>
 const char*
-parse_call_expr(const char* first, const char* last, C& db)
+parse_call_expr(const char* first, const char* last, Db& db)
 {
     if (last - first >= 4 && first[0] == 'c' && first[1] == 'l')
     {
         const char* t = parse_expression(first+2, last, db);
-        if (t != first+2)
+        if (t == last || t == first + 2 || db.Names.empty())
+            return first;
+        Node* callee = db.Names.back();
+        db.Names.pop_back();
+        size_t args_begin = db.Names.size();
+        while (*t != 'E')
         {
-            if (t == last)
-                return first;
-            if (db.names.empty())
-                return first;
-            db.names.back().first += db.names.back().second;
-            db.names.back().second = typename C::String();
-            db.names.back().first.append("(");
-            bool first_expr = true;
-            while (*t != 'E')
-            {
-                const char* t1 = parse_expression(t, last, db);
-                if (t1 == t || t1 == last)
-                    return first;
-                if (db.names.empty())
-                    return first;
-                auto tmp = db.names.back().move_full();
-                db.names.pop_back();
-                if (!tmp.empty())
-                {
-                    if (db.names.empty())
-                        return first;
-                    if (!first_expr)
-                    {
-                        db.names.back().first.append(", ");
-                        first_expr = false;
-                    }
-                    db.names.back().first.append(tmp);
-                }
-                t = t1;
-            }
-            ++t;
-            if (db.names.empty())
+            const char* t1 = parse_expression(t, last, db);
+            if (t1 == last || t1 == t)
                 return first;
-            db.names.back().first.append(")");
-            first = t;
+            t = t1;
         }
+        if (db.Names.size() < args_begin)
+            return first;
+        ++t;
+        CallExpr* the_call = db.make<CallExpr>(
+            callee, db.popTrailingNodeArray(args_begin));
+        db.Names.push_back(the_call);
+        first = t;
     }
     return first;
 }
@@ -1367,9 +2979,8 @@ parse_call_expr(const char* first, const char* last, C& db)
 // [gs] na <expression>* _ <type> <initializer>         # new[] (expr-list) type (init)
 // <initializer> ::= pi <expression>* E                 # parenthesized initialization
 
-template <class C>
 const char*
-parse_new_expr(const char* first, const char* last, C& db)
+parse_new_expr(const char* first, const char* last, Db& db)
 {
     if (last - first >= 4)
     {
@@ -1386,31 +2997,18 @@ parse_new_expr(const char* first, const char* last, C& db)
             t += 2;
             if (t == last)
                 return first;
-            bool has_expr_list = false;
-            bool first_expr = true;
+            size_t first_expr_in_list = db.Names.size();
+            NodeArray ExprList, init_list;
             while (*t != '_')
             {
                 const char* t1 = parse_expression(t, last, db);
                 if (t1 == t || t1 == last)
                     return first;
-                has_expr_list = true;
-                if (!first_expr)
-                {
-                    if (db.names.empty())
-                        return first;
-                    auto tmp = db.names.back().move_full();
-                    db.names.pop_back();
-                    if (!tmp.empty())
-                    {
-                        if (db.names.empty())
-                            return first;
-                        db.names.back().first.append(", ");
-                        db.names.back().first.append(tmp);
-                        first_expr = false;
-                    }
-                }
                 t = t1;
             }
+            if (first_expr_in_list > db.Names.size())
+                return first;
+            ExprList = db.popTrailingNodeArray(first_expr_in_list);
             ++t;
             const char* t1 = parse_type(t, last, db);
             if (t1 == t || t1 == last)
@@ -1421,65 +3019,25 @@ parse_new_expr(const char* first, const char* last, C& db)
             {
                 t += 2;
                 has_init = true;
-                first_expr = true;
+                size_t init_list_begin = db.Names.size();
                 while (*t != 'E')
                 {
                     t1 = parse_expression(t, last, db);
                     if (t1 == t || t1 == last)
                         return first;
-                    if (!first_expr)
-                    {
-                        if (db.names.empty())
-                            return first;
-                        auto tmp = db.names.back().move_full();
-                        db.names.pop_back();
-                        if (!tmp.empty())
-                        {
-                            if (db.names.empty())
-                                return first;
-                            db.names.back().first.append(", ");
-                            db.names.back().first.append(tmp);
-                            first_expr = false;
-                        }
-                    }
                     t = t1;
                 }
-            }
-            if (*t != 'E')
-                return first;
-            typename C::String init_list;
-            if (has_init)
-            {
-                if (db.names.empty())
+                if (init_list_begin > db.Names.size())
                     return first;
-                init_list = db.names.back().move_full();
-                db.names.pop_back();
+                init_list = db.popTrailingNodeArray(init_list_begin);
             }
-            if (db.names.empty())
+            if (*t != 'E' || db.Names.empty())
                 return first;
-            auto type = db.names.back().move_full();
-            db.names.pop_back();
-            typename C::String expr_list;
-            if (has_expr_list)
-            {
-                if (db.names.empty())
-                    return first;
-                expr_list = db.names.back().move_full();
-                db.names.pop_back();
-            }
-            typename C::String r;
-            if (parsed_gs)
-                r = "::";
-            if (is_array)
-                r += "[] ";
-            else
-                r += " ";
-            if (has_expr_list)
-                r += "(" + expr_list + ") ";
-            r += type;
-            if (has_init)
-                r += " (" + init_list + ")";
-            db.names.push_back(std::move(r));
+            auto type = db.Names.back();
+            db.Names.pop_back();
+            db.Names.push_back(
+                db.make<NewExpr>(ExprList, type, init_list,
+                                  parsed_gs, is_array));
             first = t+1;
         }
     }
@@ -1489,18 +3047,19 @@ parse_new_expr(const char* first, const char* last, C& db)
 // cv <type> <expression>                               # conversion with one argument
 // cv <type> _ <expression>* E                          # conversion with a different number of arguments
 
-template <class C>
 const char*
-parse_conversion_expr(const char* first, const char* last, C& db)
+parse_conversion_expr(const char* first, const char* last, Db& db)
 {
     if (last - first >= 3 && first[0] == 'c' && first[1] == 'v')
     {
-        bool try_to_parse_template_args = db.try_to_parse_template_args;
-        db.try_to_parse_template_args = false;
+        bool TryToParseTemplateArgs = db.TryToParseTemplateArgs;
+        db.TryToParseTemplateArgs = false;
+        size_t type_begin = db.Names.size();
         const char* t = parse_type(first+2, last, db);
-        db.try_to_parse_template_args = try_to_parse_template_args;
+        db.TryToParseTemplateArgs = TryToParseTemplateArgs;
         if (t != first+2 && t != last)
         {
+            size_t expr_list_begin = db.Names.size();
             if (*t != '_')
             {
                 const char* t1 = parse_expression(t, last, db);
@@ -1513,41 +3072,30 @@ parse_conversion_expr(const char* first, const char* last, C& db)
                 ++t;
                 if (t == last)
                     return first;
-                if (*t == 'E')
-                    db.names.emplace_back();
-                else
+                if (*t != 'E')
                 {
-                    bool first_expr = true;
                     while (*t != 'E')
                     {
                         const char* t1 = parse_expression(t, last, db);
                         if (t1 == t || t1 == last)
                             return first;
-                        if (!first_expr)
-                        {
-                            if (db.names.empty())
-                                return first;
-                            auto tmp = db.names.back().move_full();
-                            db.names.pop_back();
-                            if (!tmp.empty())
-                            {
-                                if (db.names.empty())
-                                    return first;
-                                db.names.back().first.append(", ");
-                                db.names.back().first.append(tmp);
-                                first_expr = false;
-                            }
-                        }
                         t = t1;
                     }
                 }
                 ++t;
             }
-            if (db.names.size() < 2)
+            if (db.Names.size() < expr_list_begin ||
+                type_begin > expr_list_begin)
                 return first;
-            auto tmp = db.names.back().move_full();
-            db.names.pop_back();
-            db.names.back() = "(" + db.names.back().move_full() + ")(" + tmp + ")";
+            NodeArray expressions = db.makeNodeArray(
+                db.Names.begin() + (long)expr_list_begin, db.Names.end());
+            NodeArray types = db.makeNodeArray(
+                db.Names.begin() + (long)type_begin,
+                db.Names.begin() + (long)expr_list_begin);
+            auto* conv_expr = db.make<ConversionExpr>(
+                types, expressions);
+            db.Names.dropBack(type_begin);
+            db.Names.push_back(conv_expr);
             first = t;
         }
     }
@@ -1556,9 +3104,8 @@ parse_conversion_expr(const char* first, const char* last, C& db)
 
 // pt <expression> <expression>                    # expr->name
 
-template <class C>
 const char*
-parse_arrow_expr(const char* first, const char* last, C& db)
+parse_arrow_expr(const char* first, const char* last, Db& db)
 {
     if (last - first >= 3 && first[0] == 'p' && first[1] == 't')
     {
@@ -1568,12 +3115,12 @@ parse_arrow_expr(const char* first, const char* last, C& db)
             const char* t1 = parse_expression(t, last, db);
             if (t1 != t)
             {
-                if (db.names.size() < 2)
+                if (db.Names.size() < 2)
                     return first;
-                auto tmp = db.names.back().move_full();
-                db.names.pop_back();
-                db.names.back().first += "->";
-                db.names.back().first += tmp;
+                auto tmp = db.Names.back();
+                db.Names.pop_back();
+                db.Names.back() = db.make<MemberExpr>(
+                    db.Names.back(), "->", tmp);
                 first = t1;
             }
         }
@@ -1586,9 +3133,8 @@ parse_arrow_expr(const char* first, const char* last, C& db)
 
 // <function-type> ::= F [Y] <bare-function-type> [<ref-qualifier>] E
 
-template <class C>
 const char*
-parse_function_type(const char* first, const char* last, C& db)
+parse_function_type(const char* first, const char* last, Db& db)
 {
     if (first != last && *first == 'F')
     {
@@ -1602,16 +3148,19 @@ parse_function_type(const char* first, const char* last, C& db)
                     return first;
             }
             const char* t1 = parse_type(t, last, db);
-            if (t1 != t)
+            if (t1 != t && !db.Names.empty())
             {
+                Node* ret_type = db.Names.back();
+                db.Names.pop_back();
+                size_t params_begin = db.Names.size();
                 t = t1;
-                typename C::String sig("(");
-                int ref_qual = 0;
+                FunctionRefQual RefQuals = FrefQualNone;
                 while (true)
                 {
                     if (t == last)
                     {
-                        db.names.pop_back();
+                        if (!db.Names.empty())
+                          db.Names.pop_back();
                         return first;
                     }
                     if (*t == 'E')
@@ -1626,45 +3175,30 @@ parse_function_type(const char* first, const char* last, C& db)
                     }
                     if (*t == 'R' && t+1 != last && t[1] == 'E')
                     {
-                        ref_qual = 1;
+                        RefQuals = FrefQualLValue;
                         ++t;
                         continue;
                     }
                     if (*t == 'O' && t+1 != last && t[1] == 'E')
                     {
-                        ref_qual = 2;
+                        RefQuals = FrefQualRValue;
                         ++t;
                         continue;
                     }
-                    size_t k0 = db.names.size();
+                    size_t k0 = db.Names.size();
                     t1 = parse_type(t, last, db);
-                    size_t k1 = db.names.size();
-                    if (t1 == t || t1 == last)
+                    size_t k1 = db.Names.size();
+                    if (t1 == t || t1 == last || k1 < k0)
                         return first;
-                    for (size_t k = k0; k < k1; ++k)
-                    {
-                        if (sig.size() > 1)
-                            sig += ", ";
-                        sig += db.names[k].move_full();
-                    }
-                    for (size_t k = k0; k < k1; ++k)
-                        db.names.pop_back();
                     t = t1;
                 }
-                sig += ")";
-                switch (ref_qual)
-                {
-                case 1:
-                    sig += " &";
-                    break;
-                case 2:
-                    sig += " &&";
-                    break;
-                }
-                if (db.names.empty())
+                if (db.Names.empty() || params_begin > db.Names.size())
                     return first;
-                db.names.back().first += " ";
-                db.names.back().second.insert(0, sig);
+                Node* fty = db.make<FunctionType>(
+                    ret_type, db.popTrailingNodeArray(params_begin));
+                if (RefQuals)
+                    fty = db.make<FunctionRefQualType>(fty, RefQuals);
+                db.Names.push_back(fty);
                 first = t;
             }
         }
@@ -1674,9 +3208,8 @@ parse_function_type(const char* first, const char* last, C& db)
 
 // <pointer-to-member-type> ::= M <class type> <member type>
 
-template <class C>
 const char*
-parse_pointer_to_member_type(const char* first, const char* last, C& db)
+parse_pointer_to_member_type(const char* first, const char* last, Db& db)
 {
     if (first != last && *first == 'M')
     {
@@ -1686,21 +3219,13 @@ parse_pointer_to_member_type(const char* first, const char* last, C& db)
             const char* t2 = parse_type(t, last, db);
             if (t2 != t)
             {
-                if (db.names.size() < 2)
+                if (db.Names.size() < 2)
                     return first;
-                auto func = std::move(db.names.back());
-                db.names.pop_back();
-                auto class_type = std::move(db.names.back());
-                if (!func.second.empty() && func.second.front() == '(')
-                {
-                    db.names.back().first = std::move(func.first) + "(" + class_type.move_full() + "::*";
-                    db.names.back().second = ")" + std::move(func.second);
-                }
-                else
-                {
-                    db.names.back().first = std::move(func.first) + " " + class_type.move_full() + "::*";
-                    db.names.back().second = std::move(func.second);
-                }
+                auto func = std::move(db.Names.back());
+                db.Names.pop_back();
+                auto ClassType = std::move(db.Names.back());
+                db.Names.back() =
+                    db.make<PointerToMemberType>(ClassType, func);
                 first = t2;
             }
         }
@@ -1711,9 +3236,8 @@ parse_pointer_to_member_type(const char* first, const char* last, C& db)
 // <array-type> ::= A <positive dimension number> _ <element type>
 //              ::= A [<dimension expression>] _ <element type>
 
-template <class C>
 const char*
-parse_array_type(const char* first, const char* last, C& db)
+parse_array_type(const char* first, const char* last, Db& db)
 {
     if (first != last && *first == 'A' && first+1 != last)
     {
@@ -1722,11 +3246,9 @@ parse_array_type(const char* first, const char* last, C& db)
             const char* t = parse_type(first+2, last, db);
             if (t != first+2)
             {
-                if (db.names.empty())
+                if (db.Names.empty())
                     return first;
-                if (db.names.back().second.substr(0, 2) == " [")
-                    db.names.back().second.erase(0, 1);
-                db.names.back().second.insert(0, " []");
+                db.Names.back() = db.make<ArrayType>(db.Names.back());
                 first = t;
             }
         }
@@ -1738,11 +3260,11 @@ parse_array_type(const char* first, const char* last, C& db)
                 const char* t2 = parse_type(t+1, last, db);
                 if (t2 != t+1)
                 {
-                    if (db.names.empty())
+                    if (db.Names.empty())
                         return first;
-                    if (db.names.back().second.substr(0, 2) == " [")
-                        db.names.back().second.erase(0, 1);
-                    db.names.back().second.insert(0, " [" + typename C::String(first+1, t) + "]");
+                    db.Names.back() =
+                        db.make<ArrayType>(db.Names.back(),
+                                            StringView(first + 1, t));
                     first = t2;
                 }
             }
@@ -1755,15 +3277,13 @@ parse_array_type(const char* first, const char* last, C& db)
                 const char* t2 = parse_type(++t, last, db);
                 if (t2 != t)
                 {
-                    if (db.names.size() < 2)
+                    if (db.Names.size() < 2)
                         return first;
-                    auto type = std::move(db.names.back());
-                    db.names.pop_back();
-                    auto expr = std::move(db.names.back());
-                    db.names.back().first = std::move(type.first);
-                    if (type.second.substr(0, 2) == " [")
-                        type.second.erase(0, 1);
-                    db.names.back().second = " [" + expr.move_full() + "]" + std::move(type.second);
+                    auto base_type = std::move(db.Names.back());
+                    db.Names.pop_back();
+                    auto dimension_expr = std::move(db.Names.back());
+                    db.Names.back() =
+                        db.make<ArrayType>(base_type, dimension_expr);
                     first = t2;
                 }
             }
@@ -1775,9 +3295,8 @@ parse_array_type(const char* first, const char* last, C& db)
 // <decltype>  ::= Dt <expression> E  # decltype of an id-expression or class member access (C++0x)
 //             ::= DT <expression> E  # decltype of an expression (C++0x)
 
-template <class C>
 const char*
-parse_decltype(const char* first, const char* last, C& db)
+parse_decltype(const char* first, const char* last, Db& db)
 {
     if (last - first >= 4 && first[0] == 'D')
     {
@@ -1789,9 +3308,10 @@ parse_decltype(const char* first, const char* last, C& db)
                 const char* t = parse_expression(first+2, last, db);
                 if (t != first+2 && t != last && *t == 'E')
                 {
-                    if (db.names.empty())
+                    if (db.Names.empty())
                         return first;
-                    db.names.back() = "decltype(" + db.names.back().move_full() + ")";
+                    db.Names.back() = db.make<EnclosingExpr>(
+                        "decltype(", db.Names.back(), ")");
                     first = t+1;
                 }
             }
@@ -1808,9 +3328,8 @@ parse_decltype(const char* first, const char* last, C& db)
 // <extended element type> ::= <element type>
 //                         ::= p # AltiVec vector pixel
 
-template <class C>
 const char*
-parse_vector_type(const char* first, const char* last, C& db)
+parse_vector_type(const char* first, const char* last, Db& db)
 {
     if (last - first > 3 && first[0] == 'D' && first[1] == 'v')
     {
@@ -1828,33 +3347,36 @@ parse_vector_type(const char* first, const char* last, C& db)
                     const char* t1 = parse_type(t, last, db);
                     if (t1 != t)
                     {
-                        if (db.names.empty())
+                        if (db.Names.empty())
                             return first;
-                        db.names.back().first += " vector[" + typename C::String(num, sz) + "]";
+                        db.Names.back() =
+                            db.make<VectorType>(db.Names.back(),
+                                                 StringView(num, num + sz));
                         first = t1;
                     }
                 }
                 else
                 {
                     ++t;
-                    db.names.push_back("pixel vector[" + typename C::String(num, sz) + "]");
+                    db.Names.push_back(
+                        db.make<VectorType>(StringView(num, num + sz)));
                     first = t;
                 }
             }
         }
         else
         {
-            typename C::String num;
+            Node* num = nullptr;
             const char* t1 = first+2;
             if (*t1 != '_')
             {
                 const char* t = parse_expression(t1, last, db);
                 if (t != t1)
                 {
-                    if (db.names.empty())
+                    if (db.Names.empty())
                         return first;
-                    num = db.names.back().move_full();
-                    db.names.pop_back();
+                    num = db.Names.back();
+                    db.Names.pop_back();
                     t1 = t;
                 }
             }
@@ -1863,11 +3385,17 @@ parse_vector_type(const char* first, const char* last, C& db)
                 const char* t = parse_type(t1, last, db);
                 if (t != t1)
                 {
-                    if (db.names.empty())
+                    if (db.Names.empty())
                         return first;
-                    db.names.back().first += " vector[" + num + "]";
+                    if (num)
+                        db.Names.back() =
+                            db.make<VectorType>(db.Names.back(), num);
+                    else
+                        db.Names.back() =
+                            db.make<VectorType>(db.Names.back(), StringView());
                     first = t;
-                }
+                } else if (num)
+                    db.Names.push_back(num);
             }
         }
     }
@@ -1883,7 +3411,7 @@ parse_vector_type(const char* first, const char* last, C& db)
 //        ::= <template-template-param> <template-args>
 //        ::= <decltype>
 //        ::= <substitution>
-//        ::= <CV-qualifiers> <type>
+//        ::= <CV-Qualifiers> <type>
 //        ::= P <type>        # pointer-to
 //        ::= R <type>        # reference-to
 //        ::= O <type>        # rvalue reference-to (C++0x)
@@ -1897,9 +3425,8 @@ parse_vector_type(const char* first, const char* last, C& db)
 // <objc-name> ::= <k0 number> objcproto <k1 number> <identifier>  # k0 = 9 + <number of digits in k1> + k1
 // <objc-type> := <source-name>  # PU<11+>objcproto 11objc_object<source-name> 11objc_object -> id<source-name>
 
-template <class C>
 const char*
-parse_type(const char* first, const char* last, C& db)
+parse_type(const char* first, const char* last, Db& db)
 {
     if (first != last)
     {
@@ -1909,51 +3436,30 @@ parse_type(const char* first, const char* last, C& db)
             case 'V':
             case 'K':
               {
-                unsigned cv = 0;
+                Qualifiers cv = QualNone;
                 const char* t = parse_cv_qualifiers(first, last, cv);
                 if (t != first)
                 {
                     bool is_function = *t == 'F';
-                    size_t k0 = db.names.size();
+                    size_t k0 = db.Names.size();
                     const char* t1 = parse_type(t, last, db);
-                    size_t k1 = db.names.size();
+                    size_t k1 = db.Names.size();
                     if (t1 != t)
                     {
                         if (is_function)
-                            db.subs.pop_back();
-                        db.subs.emplace_back(db.names.get_allocator());
+                            db.Subs.popPack();
+                        db.Subs.pushPack();
                         for (size_t k = k0; k < k1; ++k)
                         {
-                            if (is_function)
-                            {
-                                size_t p = db.names[k].second.size();
-                                if (db.names[k].second[p-2] == '&')
-                                    p -= 3;
-                                else if (db.names[k].second.back() == '&')
-                                    p -= 2;
-                                if (cv & 1)
-                                {
-                                    db.names[k].second.insert(p, " const");
-                                    p += 6;
-                                }
-                                if (cv & 2)
-                                {
-                                    db.names[k].second.insert(p, " volatile");
-                                    p += 9;
-                                }
-                                if (cv & 4)
-                                    db.names[k].second.insert(p, " restrict");
-                            }
-                            else
-                            {
-                                if (cv & 1)
-                                    db.names[k].first.append(" const");
-                                if (cv & 2)
-                                    db.names[k].first.append(" volatile");
-                                if (cv & 4)
-                                    db.names[k].first.append(" restrict");
+                            if (cv) {
+                                if (is_function)
+                                    db.Names[k] = db.make<FunctionQualType>(
+                                        db.Names[k], cv);
+                                else
+                                    db.Names[k] =
+                                        db.make<QualType>(db.Names[k], cv);
                             }
-                            db.subs.back().push_back(db.names[k]);
+                            db.Subs.pushSubstitutionIntoPack(db.Names[k]);
                         }
                         first = t1;
                     }
@@ -1975,77 +3481,69 @@ parse_type(const char* first, const char* last, C& db)
                         t = parse_array_type(first, last, db);
                         if (t != first)
                         {
-                            if (db.names.empty())
+                            if (db.Names.empty())
                                 return first;
                             first = t;
-                            db.subs.push_back(typename C::sub_type(1, db.names.back(), db.names.get_allocator()));
+                            db.Subs.pushSubstitution(db.Names.back());
                         }
                         break;
                     case 'C':
                         t = parse_type(first+1, last, db);
                         if (t != first+1)
                         {
-                            if (db.names.empty())
+                            if (db.Names.empty())
                                 return first;
-                            db.names.back().first.append(" complex");
+                            db.Names.back() = db.make<PostfixQualifiedType>(
+                                db.Names.back(), " complex");
                             first = t;
-                            db.subs.push_back(typename C::sub_type(1, db.names.back(), db.names.get_allocator()));
+                            db.Subs.pushSubstitution(db.Names.back());
                         }
                         break;
                     case 'F':
                         t = parse_function_type(first, last, db);
                         if (t != first)
                         {
-                            if (db.names.empty())
+                            if (db.Names.empty())
                                 return first;
                             first = t;
-                            db.subs.push_back(typename C::sub_type(1, db.names.back(), db.names.get_allocator()));
+                            db.Subs.pushSubstitution(db.Names.back());
                         }
                         break;
                     case 'G':
                         t = parse_type(first+1, last, db);
                         if (t != first+1)
                         {
-                            if (db.names.empty())
+                            if (db.Names.empty())
                                 return first;
-                            db.names.back().first.append(" imaginary");
+                            db.Names.back() = db.make<PostfixQualifiedType>(
+                                db.Names.back(), " imaginary");
                             first = t;
-                            db.subs.push_back(typename C::sub_type(1, db.names.back(), db.names.get_allocator()));
+                            db.Subs.pushSubstitution(db.Names.back());
                         }
                         break;
                     case 'M':
                         t = parse_pointer_to_member_type(first, last, db);
                         if (t != first)
                         {
-                            if (db.names.empty())
+                            if (db.Names.empty())
                                 return first;
                             first = t;
-                            db.subs.push_back(typename C::sub_type(1, db.names.back(), db.names.get_allocator()));
+                            db.Subs.pushSubstitution(db.Names.back());
                         }
                         break;
                     case 'O':
                       {
-                        size_t k0 = db.names.size();
+                        size_t k0 = db.Names.size();
                         t = parse_type(first+1, last, db);
-                        size_t k1 = db.names.size();
+                        size_t k1 = db.Names.size();
                         if (t != first+1)
                         {
-                            db.subs.emplace_back(db.names.get_allocator());
+                            db.Subs.pushPack();
                             for (size_t k = k0; k < k1; ++k)
                             {
-                                if (db.names[k].second.substr(0, 2) == " [")
-                                {
-                                    db.names[k].first += " (";
-                                    db.names[k].second.insert(0, ")");
-                                }
-                                else if (!db.names[k].second.empty() &&
-                                          db.names[k].second.front() == '(')
-                                {
-                                    db.names[k].first += "(";
-                                    db.names[k].second.insert(0, ")");
-                                }
-                                db.names[k].first.append("&&");
-                                db.subs.back().push_back(db.names[k]);
+                                db.Names[k] =
+                                    db.make<RValueReferenceType>(db.Names[k]);
+                                db.Subs.pushSubstitutionIntoPack(db.Names[k]);
                             }
                             first = t;
                         }
@@ -2053,34 +3551,16 @@ parse_type(const char* first, const char* last, C& db)
                       }
                     case 'P':
                       {
-                        size_t k0 = db.names.size();
+                        size_t k0 = db.Names.size();
                         t = parse_type(first+1, last, db);
-                        size_t k1 = db.names.size();
+                        size_t k1 = db.Names.size();
                         if (t != first+1)
                         {
-                            db.subs.emplace_back(db.names.get_allocator());
+                            db.Subs.pushPack();
                             for (size_t k = k0; k < k1; ++k)
                             {
-                                if (db.names[k].second.substr(0, 2) == " [")
-                                {
-                                    db.names[k].first += " (";
-                                    db.names[k].second.insert(0, ")");
-                                }
-                                else if (!db.names[k].second.empty() &&
-                                          db.names[k].second.front() == '(')
-                                {
-                                    db.names[k].first += "(";
-                                    db.names[k].second.insert(0, ")");
-                                }
-                                if (first[1] != 'U' || db.names[k].first.substr(0, 12) != "objc_object<")
-                                {
-                                    db.names[k].first.append("*");
-                                }
-                                else
-                                {
-                                    db.names[k].first.replace(0, 11, "id");
-                                }
-                                db.subs.back().push_back(db.names[k]);
+                                db.Names[k] = db.make<PointerType>(db.Names[k]);
+                                db.Subs.pushSubstitutionIntoPack(db.Names[k]);
                             }
                             first = t;
                         }
@@ -2088,27 +3568,17 @@ parse_type(const char* first, const char* last, C& db)
                       }
                     case 'R':
                       {
-                        size_t k0 = db.names.size();
+                        size_t k0 = db.Names.size();
                         t = parse_type(first+1, last, db);
-                        size_t k1 = db.names.size();
+                        size_t k1 = db.Names.size();
                         if (t != first+1)
                         {
-                            db.subs.emplace_back(db.names.get_allocator());
+                            db.Subs.pushPack();
                             for (size_t k = k0; k < k1; ++k)
                             {
-                                if (db.names[k].second.substr(0, 2) == " [")
-                                {
-                                    db.names[k].first += " (";
-                                    db.names[k].second.insert(0, ")");
-                                }
-                                else if (!db.names[k].second.empty() &&
-                                          db.names[k].second.front() == '(')
-                                {
-                                    db.names[k].first += "(";
-                                    db.names[k].second.insert(0, ")");
-                                }
-                                db.names[k].first.append("&");
-                                db.subs.back().push_back(db.names[k]);
+                                db.Names[k] =
+                                    db.make<LValueReferenceType>(db.Names[k]);
+                                db.Subs.pushSubstitutionIntoPack(db.Names[k]);
                             }
                             first = t;
                         }
@@ -2116,23 +3586,25 @@ parse_type(const char* first, const char* last, C& db)
                       }
                     case 'T':
                       {
-                        size_t k0 = db.names.size();
+                        size_t k0 = db.Names.size();
                         t = parse_template_param(first, last, db);
-                        size_t k1 = db.names.size();
+                        size_t k1 = db.Names.size();
                         if (t != first)
                         {
-                            db.subs.emplace_back(db.names.get_allocator());
+                            db.Subs.pushPack();
                             for (size_t k = k0; k < k1; ++k)
-                                db.subs.back().push_back(db.names[k]);
-                            if (db.try_to_parse_template_args && k1 == k0+1)
+                                db.Subs.pushSubstitutionIntoPack(db.Names[k]);
+                            if (db.TryToParseTemplateArgs && k1 == k0+1)
                             {
                                 const char* t1 = parse_template_args(t, last, db);
                                 if (t1 != t)
                                 {
-                                    auto args = db.names.back().move_full();
-                                    db.names.pop_back();
-                                    db.names.back().first += std::move(args);
-                                    db.subs.push_back(typename C::sub_type(1, db.names.back(), db.names.get_allocator()));
+                                    auto args = db.Names.back();
+                                    db.Names.pop_back();
+                                    db.Names.back() = db.make<
+                                        NameWithTemplateArgs>(
+                                        db.Names.back(), args);
+                                    db.Subs.pushSubstitution(db.Names.back());
                                     t = t1;
                                 }
                             }
@@ -2149,29 +3621,30 @@ parse_type(const char* first, const char* last, C& db)
                                 const char* t2 = parse_type(t, last, db);
                                 if (t2 != t)
                                 {
-                                    if (db.names.size() < 2)
+                                    if (db.Names.size() < 2)
                                         return first;
-                                    auto type = db.names.back().move_full();
-                                    db.names.pop_back();
-                                    if (db.names.back().first.substr(0, 9) != "objcproto")
+                                    auto type = db.Names.back();
+                                    db.Names.pop_back();
+                                    if (db.Names.back()->K != Node::KNameType ||
+                                        !static_cast<NameType*>(db.Names.back())->getName().startsWith("objcproto"))
                                     {
-                                        db.names.back() = type + " " + db.names.back().move_full();
+                                        db.Names.back() = db.make<VendorExtQualType>(type, db.Names.back());
                                     }
                                     else
                                     {
-                                        auto proto = db.names.back().move_full();
-                                        db.names.pop_back();
-                                        t = parse_source_name(proto.data() + 9, proto.data() + proto.size(), db);
-                                        if (t != proto.data() + 9)
+                                        auto* proto = static_cast<NameType*>(db.Names.back());
+                                        db.Names.pop_back();
+                                        t = parse_source_name(proto->getName().begin() + 9, proto->getName().end(), db);
+                                        if (t != proto->getName().begin() + 9)
                                         {
-                                            db.names.back() = type + "<" + db.names.back().move_full() + ">";
+                                            db.Names.back() = db.make<ObjCProtoName>(type, db.Names.back());
                                         }
                                         else
                                         {
-                                            db.names.push_back(type + " " + proto);
+                                            db.Names.push_back(db.make<VendorExtQualType>(type, proto));
                                         }
                                     }
-                                    db.subs.push_back(typename C::sub_type(1, db.names.back(), db.names.get_allocator()));
+                                    db.Subs.pushSubstitution(db.Names.back());
                                     first = t2;
                                 }
                             }
@@ -2183,9 +3656,9 @@ parse_type(const char* first, const char* last, C& db)
                             t = parse_name(first, last, db);
                             if (t != first)
                             {
-                                if (db.names.empty())
+                                if (db.Names.empty())
                                     return first;
-                                db.subs.push_back(typename C::sub_type(1, db.names.back(), db.names.get_allocator()));
+                                db.Subs.pushSubstitution(db.Names.back());
                                 first = t;
                             }
                         }
@@ -2197,17 +3670,22 @@ parse_type(const char* first, const char* last, C& db)
                                 first = t;
                                 // Parsed a substitution.  If the substitution is a
                                 //  <template-param> it might be followed by <template-args>.
-                                t = parse_template_args(first, last, db);
-                                if (t != first)
+                                if (db.TryToParseTemplateArgs)
                                 {
-                                    if (db.names.size() < 2)
-                                        return first;
-                                    auto template_args = db.names.back().move_full();
-                                    db.names.pop_back();
-                                    db.names.back().first += template_args;
-                                    // Need to create substitution for <template-template-param> <template-args>
-                                    db.subs.push_back(typename C::sub_type(1, db.names.back(), db.names.get_allocator()));
-                                    first = t;
+                                    t = parse_template_args(first, last, db);
+                                    if (t != first)
+                                    {
+                                        if (db.Names.size() < 2)
+                                            return first;
+                                        auto template_args = db.Names.back();
+                                        db.Names.pop_back();
+                                        db.Names.back() = db.make<
+                                          NameWithTemplateArgs>(
+                                              db.Names.back(), template_args);
+                                        // Need to create substitution for <template-template-param> <template-args>
+                                        db.Subs.pushSubstitution(db.Names.back());
+                                        first = t;
+                                    }
                                 }
                             }
                         }
@@ -2219,14 +3697,14 @@ parse_type(const char* first, const char* last, C& db)
                             {
                             case 'p':
                               {
-                                size_t k0 = db.names.size();
+                                size_t k0 = db.Names.size();
                                 t = parse_type(first+2, last, db);
-                                size_t k1 = db.names.size();
+                                size_t k1 = db.Names.size();
                                 if (t != first+2)
                                 {
-                                    db.subs.emplace_back(db.names.get_allocator());
+                                    db.Subs.pushPack();
                                     for (size_t k = k0; k < k1; ++k)
-                                        db.subs.back().push_back(db.names[k]);
+                                        db.Subs.pushSubstitutionIntoPack(db.Names[k]);
                                     first = t;
                                     return first;
                                 }
@@ -2237,9 +3715,9 @@ parse_type(const char* first, const char* last, C& db)
                                 t = parse_decltype(first, last, db);
                                 if (t != first)
                                 {
-                                    if (db.names.empty())
+                                    if (db.Names.empty())
                                         return first;
-                                    db.subs.push_back(typename C::sub_type(1, db.names.back(), db.names.get_allocator()));
+                                    db.Subs.pushSubstitution(db.Names.back());
                                     first = t;
                                     return first;
                                 }
@@ -2248,16 +3726,16 @@ parse_type(const char* first, const char* last, C& db)
                                 t = parse_vector_type(first, last, db);
                                 if (t != first)
                                 {
-                                    if (db.names.empty())
+                                    if (db.Names.empty())
                                         return first;
-                                    db.subs.push_back(typename C::sub_type(1, db.names.back(), db.names.get_allocator()));
+                                    db.Subs.pushSubstitution(db.Names.back());
                                     first = t;
                                     return first;
                                 }
                                 break;
                             }
                         }
-                        // drop through
+                        _LIBCPP_FALLTHROUGH();
                     default:
                         // must check for builtin-types before class-enum-types to avoid
                         // ambiguities with operator-names
@@ -2271,9 +3749,9 @@ parse_type(const char* first, const char* last, C& db)
                             t = parse_name(first, last, db);
                             if (t != first)
                             {
-                                if (db.names.empty())
+                                if (db.Names.empty())
                                     return first;
-                                db.subs.push_back(typename C::sub_type(1, db.names.back(), db.names.get_allocator()));
+                                db.Subs.pushSubstitution(db.Names.back());
                                 first = t;
                             }
                         }
@@ -2338,11 +3816,11 @@ parse_type(const char* first, const char* last, C& db)
 //                   ::= rs    # >>            
 //                   ::= rS    # >>=           
 //                   ::= v <digit> <source-name>        # vendor extended operator
-
-template <class C>
+//   extension       ::= <operator-name> <abi-tag-seq>
 const char*
-parse_operator_name(const char* first, const char* last, C& db)
+parse_operator_name(const char* first, const char* last, Db& db)
 {
+    const char* original_first = first;
     if (last - first >= 2)
     {
         switch (first[0])
@@ -2351,20 +3829,20 @@ parse_operator_name(const char* first, const char* last, C& db)
             switch (first[1])
             {
             case 'a':
-                db.names.push_back("operator&&");
+                db.Names.push_back(db.make<NameType>("operator&&"));
                 first += 2;
                 break;
             case 'd':
             case 'n':
-                db.names.push_back("operator&");
+                db.Names.push_back(db.make<NameType>("operator&"));
                 first += 2;
                 break;
             case 'N':
-                db.names.push_back("operator&=");
+                db.Names.push_back(db.make<NameType>("operator&="));
                 first += 2;
                 break;
             case 'S':
-                db.names.push_back("operator=");
+                db.Names.push_back(db.make<NameType>("operator="));
                 first += 2;
                 break;
             }
@@ -2373,29 +3851,30 @@ parse_operator_name(const char* first, const char* last, C& db)
             switch (first[1])
             {
             case 'l':
-                db.names.push_back("operator()");
+                db.Names.push_back(db.make<NameType>("operator()"));
                 first += 2;
                 break;
             case 'm':
-                db.names.push_back("operator,");
+                db.Names.push_back(db.make<NameType>("operator,"));
                 first += 2;
                 break;
             case 'o':
-                db.names.push_back("operator~");
+                db.Names.push_back(db.make<NameType>("operator~"));
                 first += 2;
                 break;
             case 'v':
                 {
-                    bool try_to_parse_template_args = db.try_to_parse_template_args;
-                    db.try_to_parse_template_args = false;
+                    bool TryToParseTemplateArgs = db.TryToParseTemplateArgs;
+                    db.TryToParseTemplateArgs = false;
                     const char* t = parse_type(first+2, last, db);
-                    db.try_to_parse_template_args = try_to_parse_template_args;
+                    db.TryToParseTemplateArgs = TryToParseTemplateArgs;
                     if (t != first+2)
                     {
-                        if (db.names.empty())
+                        if (db.Names.empty())
                             return first;
-                        db.names.back().first.insert(0, "operator ");
-                        db.parsed_ctor_dtor_cv = true;
+                        db.Names.back() =
+                            db.make<ConversionOperatorType>(db.Names.back());
+                        db.ParsedCtorDtorCV = true;
                         first = t;
                     }
                 }
@@ -2406,23 +3885,23 @@ parse_operator_name(const char* first, const char* last, C& db)
             switch (first[1])
             {
             case 'a':
-                db.names.push_back("operator delete[]");
+                db.Names.push_back(db.make<NameType>("operator delete[]"));
                 first += 2;
                 break;
             case 'e':
-                db.names.push_back("operator*");
+                db.Names.push_back(db.make<NameType>("operator*"));
                 first += 2;
                 break;
             case 'l':
-                db.names.push_back("operator delete");
+                db.Names.push_back(db.make<NameType>("operator delete"));
                 first += 2;
                 break;
             case 'v':
-                db.names.push_back("operator/");
+                db.Names.push_back(db.make<NameType>("operator/"));
                 first += 2;
                 break;
             case 'V':
-                db.names.push_back("operator/=");
+                db.Names.push_back(db.make<NameType>("operator/="));
                 first += 2;
                 break;
             }
@@ -2431,15 +3910,15 @@ parse_operator_name(const char* first, const char* last, C& db)
             switch (first[1])
             {
             case 'o':
-                db.names.push_back("operator^");
+                db.Names.push_back(db.make<NameType>("operator^"));
                 first += 2;
                 break;
             case 'O':
-                db.names.push_back("operator^=");
+                db.Names.push_back(db.make<NameType>("operator^="));
                 first += 2;
                 break;
             case 'q':
-                db.names.push_back("operator==");
+                db.Names.push_back(db.make<NameType>("operator=="));
                 first += 2;
                 break;
             }
@@ -2448,11 +3927,11 @@ parse_operator_name(const char* first, const char* last, C& db)
             switch (first[1])
             {
             case 'e':
-                db.names.push_back("operator>=");
+                db.Names.push_back(db.make<NameType>("operator>="));
                 first += 2;
                 break;
             case 't':
-                db.names.push_back("operator>");
+                db.Names.push_back(db.make<NameType>("operator>"));
                 first += 2;
                 break;
             }
@@ -2460,7 +3939,7 @@ parse_operator_name(const char* first, const char* last, C& db)
         case 'i':
             if (first[1] == 'x')
             {
-                db.names.push_back("operator[]");
+                db.Names.push_back(db.make<NameType>("operator[]"));
                 first += 2;
             }
             break;
@@ -2468,7 +3947,7 @@ parse_operator_name(const char* first, const char* last, C& db)
             switch (first[1])
             {
             case 'e':
-                db.names.push_back("operator<=");
+                db.Names.push_back(db.make<NameType>("operator<="));
                 first += 2;
                 break;
             case 'i':
@@ -2476,23 +3955,24 @@ parse_operator_name(const char* first, const char* last, C& db)
                     const char* t = parse_source_name(first+2, last, db);
                     if (t != first+2)
                     {
-                        if (db.names.empty())
+                        if (db.Names.empty())
                             return first;
-                        db.names.back().first.insert(0, "operator\"\" ");
+                        db.Names.back() =
+                            db.make<LiteralOperator>(db.Names.back());
                         first = t;
                     }
                 }
                 break;
             case 's':
-                db.names.push_back("operator<<");
+                db.Names.push_back(db.make<NameType>("operator<<"));
                 first += 2;
                 break;
             case 'S':
-                db.names.push_back("operator<<=");
+                db.Names.push_back(db.make<NameType>("operator<<="));
                 first += 2;
                 break;
             case 't':
-                db.names.push_back("operator<");
+                db.Names.push_back(db.make<NameType>("operator<"));
                 first += 2;
                 break;
             }
@@ -2501,23 +3981,23 @@ parse_operator_name(const char* first, const char* last, C& db)
             switch (first[1])
             {
             case 'i':
-                db.names.push_back("operator-");
+                db.Names.push_back(db.make<NameType>("operator-"));
                 first += 2;
                 break;
             case 'I':
-                db.names.push_back("operator-=");
+                db.Names.push_back(db.make<NameType>("operator-="));
                 first += 2;
                 break;
             case 'l':
-                db.names.push_back("operator*");
+                db.Names.push_back(db.make<NameType>("operator*"));
                 first += 2;
                 break;
             case 'L':
-                db.names.push_back("operator*=");
+                db.Names.push_back(db.make<NameType>("operator*="));
                 first += 2;
                 break;
             case 'm':
-                db.names.push_back("operator--");
+                db.Names.push_back(db.make<NameType>("operator--"));
                 first += 2;
                 break;
             }
@@ -2526,23 +4006,23 @@ parse_operator_name(const char* first, const char* last, C& db)
             switch (first[1])
             {
             case 'a':
-                db.names.push_back("operator new[]");
+                db.Names.push_back(db.make<NameType>("operator new[]"));
                 first += 2;
                 break;
             case 'e':
-                db.names.push_back("operator!=");
+                db.Names.push_back(db.make<NameType>("operator!="));
                 first += 2;
                 break;
             case 'g':
-                db.names.push_back("operator-");
+                db.Names.push_back(db.make<NameType>("operator-"));
                 first += 2;
                 break;
             case 't':
-                db.names.push_back("operator!");
+                db.Names.push_back(db.make<NameType>("operator!"));
                 first += 2;
                 break;
             case 'w':
-                db.names.push_back("operator new");
+                db.Names.push_back(db.make<NameType>("operator new"));
                 first += 2;
                 break;
             }
@@ -2551,15 +4031,15 @@ parse_operator_name(const char* first, const char* last, C& db)
             switch (first[1])
             {
             case 'o':
-                db.names.push_back("operator||");
+                db.Names.push_back(db.make<NameType>("operator||"));
                 first += 2;
                 break;
             case 'r':
-                db.names.push_back("operator|");
+                db.Names.push_back(db.make<NameType>("operator|"));
                 first += 2;
                 break;
             case 'R':
-                db.names.push_back("operator|=");
+                db.Names.push_back(db.make<NameType>("operator|="));
                 first += 2;
                 break;
             }
@@ -2568,27 +4048,27 @@ parse_operator_name(const char* first, const char* last, C& db)
             switch (first[1])
             {
             case 'm':
-                db.names.push_back("operator->*");
+                db.Names.push_back(db.make<NameType>("operator->*"));
                 first += 2;
                 break;
             case 'l':
-                db.names.push_back("operator+");
+                db.Names.push_back(db.make<NameType>("operator+"));
                 first += 2;
                 break;
             case 'L':
-                db.names.push_back("operator+=");
+                db.Names.push_back(db.make<NameType>("operator+="));
                 first += 2;
                 break;
             case 'p':
-                db.names.push_back("operator++");
+                db.Names.push_back(db.make<NameType>("operator++"));
                 first += 2;
                 break;
             case 's':
-                db.names.push_back("operator+");
+                db.Names.push_back(db.make<NameType>("operator+"));
                 first += 2;
                 break;
             case 't':
-                db.names.push_back("operator->");
+                db.Names.push_back(db.make<NameType>("operator->"));
                 first += 2;
                 break;
             }
@@ -2596,7 +4076,7 @@ parse_operator_name(const char* first, const char* last, C& db)
         case 'q':
             if (first[1] == 'u')
             {
-                db.names.push_back("operator?");
+                db.Names.push_back(db.make<NameType>("operator?"));
                 first += 2;
             }
             break;
@@ -2604,19 +4084,19 @@ parse_operator_name(const char* first, const char* last, C& db)
             switch (first[1])
             {
             case 'm':
-                db.names.push_back("operator%");
+                db.Names.push_back(db.make<NameType>("operator%"));
                 first += 2;
                 break;
             case 'M':
-                db.names.push_back("operator%=");
+                db.Names.push_back(db.make<NameType>("operator%="));
                 first += 2;
                 break;
             case 's':
-                db.names.push_back("operator>>");
+                db.Names.push_back(db.make<NameType>("operator>>"));
                 first += 2;
                 break;
             case 'S':
-                db.names.push_back("operator>>=");
+                db.Names.push_back(db.make<NameType>("operator>>="));
                 first += 2;
                 break;
             }
@@ -2627,37 +4107,31 @@ parse_operator_name(const char* first, const char* last, C& db)
                 const char* t = parse_source_name(first+2, last, db);
                 if (t != first+2)
                 {
-                    if (db.names.empty())
+                    if (db.Names.empty())
                         return first;
-                    db.names.back().first.insert(0, "operator ");
+                    db.Names.back() =
+                        db.make<ConversionOperatorType>(db.Names.back());
                     first = t;
                 }
             }
             break;
         }
     }
+
+    if (original_first != first)
+        first = parse_abi_tag_seq(first, last, db);
+
     return first;
 }
 
-template <class C>
 const char*
-parse_integer_literal(const char* first, const char* last, const typename C::String& lit, C& db)
+parse_integer_literal(const char* first, const char* last, StringView lit, Db& db)
 {
     const char* t = parse_number(first, last);
     if (t != first && t != last && *t == 'E')
     {
-        if (lit.size() > 3)
-            db.names.push_back("(" + lit + ")");
-        else
-            db.names.emplace_back();
-        if (*first == 'n')
-        {
-            db.names.back().first += '-';
-            ++first;
-        }
-        db.names.back().first.append(first, t);
-        if (lit.size() <= 3)
-            db.names.back().first += lit;
+        db.Names.push_back(
+            db.make<IntegerExpr>(lit, StringView(first, t)));
         first = t+1;
     }
     return first;
@@ -2670,9 +4144,8 @@ parse_integer_literal(const char* first, const char* last, const typename C::Str
 //                ::= L <type> <real-part float> _ <imag-part float> E   # complex floating point literal (C 2000)
 //                ::= L <mangled-name> E                                 # external name
 
-template <class C>
 const char*
-parse_expr_primary(const char* first, const char* last, C& db)
+parse_expr_primary(const char* first, const char* last, Db& db)
 {
     if (last - first >= 4 && *first == 'L')
     {
@@ -2691,11 +4164,11 @@ parse_expr_primary(const char* first, const char* last, C& db)
                 switch (first[2])
                 {
                 case '0':
-                    db.names.push_back("false");
+                    db.Names.push_back(db.make<BoolExpr>(0));
                     first += 4;
                     break;
                 case '1':
-                    db.names.push_back("true");
+                    db.Names.push_back(db.make<BoolExpr>(1));
                     first += 4;
                     break;
                 }
@@ -2838,9 +4311,10 @@ parse_expr_primary(const char* first, const char* last, C& db)
                             ;
                         if (n != t && n != last && *n == 'E')
                         {
-                            if (db.names.empty())
+                            if (db.Names.empty())
                                 return first;
-                            db.names.back() = "(" + db.names.back().move_full() + ")" + typename C::String(t, n);
+                            db.Names.back() = db.make<IntegerCastExpr>(
+                                db.Names.back(), StringView(t, n));
                             first = n+1;
                             break;
                         }
@@ -2857,65 +4331,22 @@ parse_expr_primary(const char* first, const char* last, C& db)
     return first;
 }
 
-template <class String>
-String
-base_name(String& s)
+Node* maybe_change_special_sub_name(Node* inp, Db& db)
 {
-    if (s.empty())
-        return s;
-    if (s == "std::string")
-    {
-        s = "std::basic_string<char, std::char_traits<char>, std::allocator<char> >";
-        return "basic_string";
-    }
-    if (s == "std::istream")
-    {
-        s = "std::basic_istream<char, std::char_traits<char> >";
-        return "basic_istream";
-    }
-    if (s == "std::ostream")
+    if (inp->K != Node::KSpecialSubstitution)
+        return inp;
+    auto Kind = static_cast<SpecialSubstitution*>(inp)->SSK;
+    switch (Kind)
     {
-        s = "std::basic_ostream<char, std::char_traits<char> >";
-        return "basic_ostream";
-    }
-    if (s == "std::iostream")
-    {
-        s = "std::basic_iostream<char, std::char_traits<char> >";
-        return "basic_iostream";
-    }
-    const char* const pf = s.data();
-    const char* pe = pf + s.size();
-    if (pe[-1] == '>')
-    {
-        unsigned c = 1;
-        while (true)
-        {
-            if (--pe == pf)
-                return String();
-            if (pe[-1] == '<')
-            {
-                if (--c == 0)
-                {
-                    --pe;
-                    break;
-                }
-            }
-            else if (pe[-1] == '>')
-                ++c;
-        }
-    }
-    if (pe - pf <= 1)
-      return String();
-    const char* p0 = pe - 1;
-    for (; p0 != pf; --p0)
-    {
-        if (*p0 == ':')
-        {
-            ++p0;
-            break;
-        }
+    case SpecialSubKind::string:
+    case SpecialSubKind::istream:
+    case SpecialSubKind::ostream:
+    case SpecialSubKind::iostream:
+        return db.make<ExpandedSpecialSubstitution>(Kind);
+    default:
+        break;
     }
-    return String(p0, pe);
+    return inp;
 }
 
 // <ctor-dtor-name> ::= C1    # complete object constructor
@@ -2926,12 +4357,11 @@ base_name(String& s)
 //                  ::= D1    # complete object destructor
 //                  ::= D2    # base object destructor
 //   extension      ::= D5    # ?
-
-template <class C>
+//   extension      ::= <ctor-dtor-name> <abi-tag-seq>
 const char*
-parse_ctor_dtor_name(const char* first, const char* last, C& db)
+parse_ctor_dtor_name(const char* first, const char* last, Db& db)
 {
-    if (last-first >= 2 && !db.names.empty())
+    if (last-first >= 2 && !db.Names.empty())
     {
         switch (first[0])
         {
@@ -2942,11 +4372,15 @@ parse_ctor_dtor_name(const char* first, const char* last, C& db)
             case '2':
             case '3':
             case '5':
-                if (db.names.empty())
+                if (db.Names.empty())
                     return first;
-                db.names.push_back(base_name(db.names.back().first));
+                db.Names.back() =
+                    maybe_change_special_sub_name(db.Names.back(), db);
+                db.Names.push_back(
+                    db.make<CtorDtorName>(db.Names.back(), false));
                 first += 2;
-                db.parsed_ctor_dtor_cv = true;
+                first = parse_abi_tag_seq(first, last, db);
+                db.ParsedCtorDtorCV = true;
                 break;
             }
             break;
@@ -2957,11 +4391,13 @@ parse_ctor_dtor_name(const char* first, const char* last, C& db)
             case '1':
             case '2':
             case '5':
-                if (db.names.empty())
+                if (db.Names.empty())
                     return first;
-                db.names.push_back("~" + base_name(db.names.back().first));
+                db.Names.push_back(
+                    db.make<CtorDtorName>(db.Names.back(), true));
                 first += 2;
-                db.parsed_ctor_dtor_cv = true;
+                first = parse_abi_tag_seq(first, last, db);
+                db.ParsedCtorDtorCV = true;
                 break;
             }
             break;
@@ -2970,16 +4406,14 @@ parse_ctor_dtor_name(const char* first, const char* last, C& db)
     return first;
 }
 
-// <unnamed-type-name> ::= Ut [ <nonnegative number> ] _
+// <unnamed-type-name> ::= Ut [<nonnegative number>] _ [<abi-tag-seq>]
 //                     ::= <closure-type-name>
 // 
 // <closure-type-name> ::= Ul <lambda-sig> E [ <nonnegative number> ] _ 
 // 
 // <lambda-sig> ::= <parameter type>+  # Parameter types or "v" if the lambda has no parameters
-
-template <class C>
 const char*
-parse_unnamed_type_name(const char* first, const char* last, C& db)
+parse_unnamed_type_name(const char* first, const char* last, Db& db)
 {
     if (last - first > 2 && first[0] == 'U')
     {
@@ -2988,101 +4422,64 @@ parse_unnamed_type_name(const char* first, const char* last, C& db)
         {
         case 't':
           {
-            db.names.push_back(typename C::String("'unnamed"));
             const char* t0 = first+2;
             if (t0 == last)
-            {
-                db.names.pop_back();
                 return first;
-            }
+            StringView count;
             if (std::isdigit(*t0))
             {
                 const char* t1 = t0 + 1;
                 while (t1 != last && std::isdigit(*t1))
                     ++t1;
-                db.names.back().first.append(t0, t1);
+                count = StringView(t0, t1);
                 t0 = t1;
             }
-            db.names.back().first.push_back('\'');
             if (t0 == last || *t0 != '_')
-            {
-                db.names.pop_back();
                 return first;
-            }
+            db.Names.push_back(db.make<UnnamedTypeName>(count));
             first = t0 + 1;
+            first = parse_abi_tag_seq(first, last, db);
           }
             break;
         case 'l':
           {
-            db.names.push_back(typename C::String("'lambda'("));
+            size_t begin_pos = db.Names.size();
             const char* t0 = first+2;
+            NodeArray lambda_params;
             if (first[2] == 'v')
             {
-                db.names.back().first += ')';
                 ++t0;
             }
             else
             {
-                const char* t1 = parse_type(t0, last, db);
-                if (t1 == t0)
-                {
-                    if(!db.names.empty())
-                        db.names.pop_back();
-                    return first;
-                }
-                if (db.names.size() < 2)
-                    return first;
-                auto tmp = db.names.back().move_full();
-                db.names.pop_back();
-                db.names.back().first.append(tmp);
-                t0 = t1;
                 while (true)
                 {
-                    t1 = parse_type(t0, last, db);
+                    const char* t1 = parse_type(t0, last, db);
                     if (t1 == t0)
                         break;
-                    if (db.names.size() < 2)
-                        return first;
-                    tmp = db.names.back().move_full();
-                    db.names.pop_back();
-                    if (!tmp.empty())
-                    {
-                        db.names.back().first.append(", ");
-                        db.names.back().first.append(tmp);
-                    }
                     t0 = t1;
                 }
-                if(db.names.empty())
-                  return first;
-                db.names.back().first.append(")");
+                if (db.Names.size() < begin_pos)
+                    return first;
+                lambda_params = db.popTrailingNodeArray(begin_pos);
             }
             if (t0 == last || *t0 != 'E')
-            {
-              if(!db.names.empty())
-                db.names.pop_back();
                 return first;
-            }
             ++t0;
             if (t0 == last)
-            {
-                if(!db.names.empty())
-                  db.names.pop_back();
                 return first;
-            }
+            StringView count;
             if (std::isdigit(*t0))
             {
                 const char* t1 = t0 + 1;
                 while (t1 != last && std::isdigit(*t1))
                     ++t1;
-                db.names.back().first.insert(db.names.back().first.begin()+7, t0, t1);
+                count = StringView(t0, t1);
                 t0 = t1;
             }
             if (t0 == last || *t0 != '_')
-            {
-                if(!db.names.empty())
-                  db.names.pop_back();
                 return first;
-            }
+            db.Names.push_back(db.make<LambdaTypeName>(lambda_params, count));
             first = t0 + 1;
           }
             break;
@@ -3096,9 +4493,8 @@ parse_unnamed_type_name(const char* first, const char* last, C& db)
 //                    ::= <source-name>   
 //                    ::= <unnamed-type-name>
 
-template <class C>
 const char*
-parse_unqualified_name(const char* first, const char* last, C& db)
+parse_unqualified_name(const char* first, const char* last, Db& db)
 {
     if (first != last)
     {
@@ -3143,9 +4539,8 @@ parse_unqualified_name(const char* first, const char* last, C& db)
 //                 ::= St <unqualified-name>   # ::std::
 // extension       ::= StL<unqualified-name>
 
-template <class C>
 const char*
-parse_unscoped_name(const char* first, const char* last, C& db)
+parse_unscoped_name(const char* first, const char* last, Db& db)
 {
     if (last - first >= 2)
     {
@@ -3163,9 +4558,10 @@ parse_unscoped_name(const char* first, const char* last, C& db)
         {
             if (St)
             {
-                if (db.names.empty())
+                if (db.Names.empty())
                     return first;
-                db.names.back().first.insert(0, "std::");
+                db.Names.back() =
+                    db.make<StdQualifiedName>(db.Names.back());
             }
             first = t1;
         }
@@ -3175,18 +4571,18 @@ parse_unscoped_name(const char* first, const char* last, C& db)
 
 // at <type>                                            # alignof (a type)
 
-template <class C>
 const char*
-parse_alignof_type(const char* first, const char* last, C& db)
+parse_alignof_type(const char* first, const char* last, Db& db)
 {
     if (last - first >= 3 && first[0] == 'a' && first[1] == 't')
     {
         const char* t = parse_type(first+2, last, db);
         if (t != first+2)
         {
-            if (db.names.empty())
+            if (db.Names.empty())
                 return first;
-            db.names.back().first = "alignof (" + db.names.back().move_full() + ")";
+            db.Names.back() =
+                db.make<EnclosingExpr>("alignof (", db.Names.back(), ")");
             first = t;
         }
     }
@@ -3195,57 +4591,55 @@ parse_alignof_type(const char* first, const char* last, C& db)
 
 // az <expression>                                            # alignof (a expression)
 
-template <class C>
 const char*
-parse_alignof_expr(const char* first, const char* last, C& db)
+parse_alignof_expr(const char* first, const char* last, Db& db)
 {
     if (last - first >= 3 && first[0] == 'a' && first[1] == 'z')
     {
         const char* t = parse_expression(first+2, last, db);
         if (t != first+2)
         {
-            if (db.names.empty())
+            if (db.Names.empty())
                 return first;
-            db.names.back().first = "alignof (" + db.names.back().move_full() + ")";
+            db.Names.back() =
+                db.make<EnclosingExpr>("alignof (", db.Names.back(), ")");
             first = t;
         }
     }
     return first;
 }
 
-template <class C>
 const char*
-parse_noexcept_expression(const char* first, const char* last, C& db)
+parse_noexcept_expression(const char* first, const char* last, Db& db)
 {
     const char* t1 = parse_expression(first, last, db);
     if (t1 != first)
     {
-        if (db.names.empty())
+        if (db.Names.empty())
             return first;
-        db.names.back().first =  "noexcept (" + db.names.back().move_full() + ")";
+        db.Names.back() =
+            db.make<EnclosingExpr>("noexcept (", db.Names.back(), ")");
         first = t1;
     }
     return first;
 }
 
-template <class C>
 const char*
-parse_prefix_expression(const char* first, const char* last, const typename C::String& op, C& db)
+parse_prefix_expression(const char* first, const char* last, StringView op, Db& db)
 {
     const char* t1 = parse_expression(first, last, db);
     if (t1 != first)
     {
-        if (db.names.empty())
+        if (db.Names.empty())
             return first;
-        db.names.back().first =  op + "(" + db.names.back().move_full() + ")";
+        db.Names.back() = db.make<PrefixExpr>(op, db.Names.back());
         first = t1;
     }
     return first;
 }
 
-template <class C>
 const char*
-parse_binary_expression(const char* first, const char* last, const typename C::String& op, C& db)
+parse_binary_expression(const char* first, const char* last, StringView op, Db& db)
 {
     const char* t1 = parse_expression(first, last, db);
     if (t1 != first)
@@ -3253,22 +4647,14 @@ parse_binary_expression(const char* first, const char* last, const typename C::S
         const char* t2 = parse_expression(t1, last, db);
         if (t2 != t1)
         {
-            if (db.names.size() < 2)
+            if (db.Names.size() < 2)
                 return first;
-            auto op2 = db.names.back().move_full();
-            db.names.pop_back();
-            auto op1 = db.names.back().move_full();
-            auto& nm = db.names.back().first;
-            nm.clear();
-            if (op == ">")
-                nm += '(';
-            nm += "(" + op1 + ") " + op + " (" + op2 + ")";
-            if (op == ">")
-                nm += ')';
+            auto op2 = db.Names.back();
+            db.Names.pop_back();
+            auto op1 = db.Names.back();
+            db.Names.back() = db.make<BinaryExpr>(op1, op, op2);
             first = t2;
         }
-        else if(!db.names.empty())
-            db.names.pop_back();
     }
     return first;
 }
@@ -3313,9 +4699,8 @@ parse_binary_expression(const char* first, const char* last, const typename C::S
 //                                                                       # objectless nonstatic member reference
 //              ::= <expr-primary>
 
-template <class C>
 const char*
-parse_expression(const char* first, const char* last, C& db)
+parse_expression(const char* first, const char* last, Db& db)
 {
     if (last - first >= 2)
     {
@@ -3405,10 +4790,10 @@ parse_expression(const char* first, const char* last, C& db)
                     const char* t1 = parse_expression(t+2, last, db);
                     if (t1 != t+2)
                     {
-                        if (db.names.empty())
+                        if (db.Names.empty())
                             return first;
-                        db.names.back().first = (parsed_gs ? typename C::String("::") : typename C::String()) +
-                                          "delete[] " + db.names.back().move_full();
+                        db.Names.back() = db.make<DeleteExpr>(
+                            db.Names.back(), parsed_gs, /*is_array=*/true);
                         first = t1;
                     }
                 }
@@ -3426,10 +4811,10 @@ parse_expression(const char* first, const char* last, C& db)
                     const char* t1 = parse_expression(t+2, last, db);
                     if (t1 != t+2)
                     {
-                        if (db.names.empty())
+                        if (db.Names.empty())
                             return first;
-                        db.names.back().first = (parsed_gs ? typename C::String("::") : typename C::String()) +
-                                          "delete " + db.names.back().move_full();
+                        db.Names.back() = db.make<DeleteExpr>(
+                            db.Names.back(), parsed_gs, /*is_array=*/false);
                         first = t1;
                     }
                 }
@@ -3498,16 +4883,17 @@ parse_expression(const char* first, const char* last, C& db)
                     const char* t2 = parse_expression(t1, last, db);
                     if (t2 != t1)
                     {
-                        if (db.names.size() < 2)
+                        if (db.Names.size() < 2)
                             return first;
-                        auto op2 = db.names.back().move_full();
-                        db.names.pop_back();
-                        auto op1 = db.names.back().move_full();
-                        db.names.back() = "(" + op1 + ")[" + op2 + "]";
+                        auto op2 = db.Names.back();
+                        db.Names.pop_back();
+                        auto op1 = db.Names.back();
+                        db.Names.back() =
+                            db.make<ArraySubscriptExpr>(op1, op2);
                         first = t2;
                     }
-                    else if (!db.names.empty())
-                        db.names.pop_back();
+                    else if (!db.Names.empty())
+                        db.Names.pop_back();
                 }
             }
             break;
@@ -3571,9 +4957,10 @@ parse_expression(const char* first, const char* last, C& db)
                     const char* t1 = parse_expression(first+2, last, db);
                     if (t1 != first+2)
                     {
-                        if (db.names.empty())
+                        if (db.Names.empty())
                             return first;
-                        db.names.back() = "(" + db.names.back().move_full() + ")--";
+                        db.Names.back() =
+                            db.make<PostfixExpr>(db.Names.back(), "--");
                         first = t1;
                     }
                 }
@@ -3661,9 +5048,10 @@ parse_expression(const char* first, const char* last, C& db)
                     const char* t1 = parse_expression(first+2, last, db);
                     if (t1 != first+2)
                     {
-                        if (db.names.empty())
+                        if (db.Names.empty())
                             return first;
-                        db.names.back() = "(" + db.names.back().move_full() + ")++";
+                        db.Names.back() =
+                            db.make<PostfixExpr>(db.Names.back(), "++");
                         first = t1;
                     }
                 }
@@ -3690,26 +5078,27 @@ parse_expression(const char* first, const char* last, C& db)
                         const char* t3 = parse_expression(t2, last, db);
                         if (t3 != t2)
                         {
-                            if (db.names.size() < 3)
+                            if (db.Names.size() < 3)
                                 return first;
-                            auto op3 = db.names.back().move_full();
-                            db.names.pop_back();
-                            auto op2 = db.names.back().move_full();
-                            db.names.pop_back();
-                            auto op1 = db.names.back().move_full();
-                            db.names.back() = "(" + op1 + ") ? (" + op2 + ") : (" + op3 + ")";
+                            auto op3 = db.Names.back();
+                            db.Names.pop_back();
+                            auto op2 = db.Names.back();
+                            db.Names.pop_back();
+                            auto op1 = db.Names.back();
+                            db.Names.back() =
+                                db.make<ConditionalExpr>(op1, op2, op3);
                             first = t3;
                         }
                         else
                         {
-                            if (db.names.size() < 2)
+                            if (db.Names.size() < 2)
                               return first;
-                            db.names.pop_back();
-                            db.names.pop_back();
+                            db.Names.pop_back();
+                            db.Names.pop_back();
                         }
                     }
-                    else if (!db.names.empty())
-                        db.names.pop_back();
+                    else if (!db.Names.empty())
+                        db.Names.pop_back();
                 }
             }
             break;
@@ -3782,7 +5171,7 @@ parse_expression(const char* first, const char* last, C& db)
                 first = parse_typeid_expr(first, last, db);
                 break;
             case 'r':
-                db.names.push_back("throw");
+                db.Names.push_back(db.make<NameType>("throw"));
                 first += 2;
                 break;
             case 'w':
@@ -3811,9 +5200,8 @@ parse_expression(const char* first, const char* last, C& db)
 //                ::= J <template-arg>* E                                # argument pack
 //                ::= LZ <encoding> E                                    # extension
 
-template <class C>
 const char*
-parse_template_arg(const char* first, const char* last, C& db)
+parse_template_arg(const char* first, const char* last, Db& db)
 {
     if (first != last)
     {
@@ -3864,57 +5252,52 @@ parse_template_arg(const char* first, const char* last, C& db)
 // <template-args> ::= I <template-arg>* E
 //     extension, the abi says <template-arg>+
 
-template <class C>
 const char*
-parse_template_args(const char* first, const char* last, C& db)
+parse_template_args(const char* first, const char* last, Db& db)
 {
     if (last - first >= 2 && *first == 'I')
     {
-        if (db.tag_templates)
-            db.template_param.back().clear();
+        if (db.TagTemplates)
+            db.TemplateParams.clear();
         const char* t = first+1;
-        typename C::String args("<");
+        size_t begin_idx = db.Names.size();
         while (*t != 'E')
         {
-            if (db.tag_templates)
-                db.template_param.emplace_back(db.names.get_allocator());
-            size_t k0 = db.names.size();
-            const char* t1 = parse_template_arg(t, last, db);
-            size_t k1 = db.names.size();
-            if (db.tag_templates)
-                db.template_param.pop_back();
-            if (t1 == t || t1 == last)
-                return first;
-            if (db.tag_templates)
+            if (db.TagTemplates)
             {
-                db.template_param.back().emplace_back(db.names.get_allocator());
+                auto TmpParams = std::move(db.TemplateParams);
+                size_t k0 = db.Names.size();
+                const char* t1 = parse_template_arg(t, last, db);
+                size_t k1 = db.Names.size();
+                db.TemplateParams = std::move(TmpParams);
+
+                if (t1 == t || t1 == last || k0 > k1)
+                    return first;
+                db.TemplateParams.pushPack();
                 for (size_t k = k0; k < k1; ++k)
-                    db.template_param.back().back().push_back(db.names[k]);
-            }
-            for (size_t k = k0; k < k1; ++k)
-            {
-                if (args.size() > 1)
-                    args += ", ";
-                args += db.names[k].move_full();
+                    db.TemplateParams.pushSubstitutionIntoPack(db.Names[k]);
+                t = t1;
+                continue;
             }
-            for (; k1 > k0; --k1)
-                if (!db.names.empty())
-                    db.names.pop_back();
+            size_t k0 = db.Names.size();
+            const char* t1 = parse_template_arg(t, last, db);
+            size_t k1 = db.Names.size();
+            if (t1 == t || t1 == last || k0 > k1)
+              return first;
             t = t1;
         }
+        if (begin_idx > db.Names.size())
+            return first;
         first = t + 1;
-        if (args.back() != '>')
-            args += ">";
-        else
-            args += " >";
-        db.names.push_back(std::move(args));
-        
+        TemplateParams* tp = db.make<TemplateParams>(
+            db.popTrailingNodeArray(begin_idx));
+        db.Names.push_back(tp);
     }
     return first;
 }
 
-// <nested-name> ::= N [<CV-qualifiers>] [<ref-qualifier>] <prefix> <unqualified-name> E
-//               ::= N [<CV-qualifiers>] [<ref-qualifier>] <template-prefix> <template-args> E
+// <nested-name> ::= N [<CV-Qualifiers>] [<ref-qualifier>] <prefix> <unqualified-name> E
+//               ::= N [<CV-Qualifiers>] [<ref-qualifier>] <template-prefix> <template-args> E
 // 
 // <prefix> ::= <prefix> <unqualified-name>
 //          ::= <template-prefix> <template-args>
@@ -3929,39 +5312,35 @@ parse_template_args(const char* first, const char* last, C& db)
 //                   ::= <template-param>
 //                   ::= <substitution>
 
-template <class C>
 const char*
-parse_nested_name(const char* first, const char* last, C& db,
+parse_nested_name(const char* first, const char* last, Db& db,
                   bool* ends_with_template_args)
 {
     if (first != last && *first == 'N')
     {
-        unsigned cv;
+        Qualifiers cv;
         const char* t0 = parse_cv_qualifiers(first+1, last, cv);
         if (t0 == last)
             return first;
-        db.ref = 0;
+        db.RefQuals = FrefQualNone;
         if (*t0 == 'R')
         {
-            db.ref = 1;
+            db.RefQuals = FrefQualLValue;
             ++t0;
         }
         else if (*t0 == 'O')
         {
-            db.ref = 2;
+            db.RefQuals = FrefQualRValue;
             ++t0;
         }
-        db.names.emplace_back();
+        db.Names.push_back(db.make<EmptyName>());
         if (last - t0 >= 2 && t0[0] == 'S' && t0[1] == 't')
         {
             t0 += 2;
-            db.names.back().first = "std";
+            db.Names.back() = db.make<NameType>("std");
         }
         if (t0 == last)
-        {
-            db.names.pop_back();
             return first;
-        }
         bool pop_subs = false;
         bool component_ends_with_template_args = false;
         while (*t0 != 'E')
@@ -3976,17 +5355,18 @@ parse_nested_name(const char* first, const char* last, C& db,
                 t1 = parse_substitution(t0, last, db);
                 if (t1 != t0 && t1 != last)
                 {
-                    auto name = db.names.back().move_full();
-                    db.names.pop_back();
-                    if (db.names.empty())
+                    if (db.Names.size() < 2)
                         return first;
-                    if (!db.names.back().first.empty())
+                    auto name = db.Names.back();
+                    db.Names.pop_back();
+                    if (db.Names.back()->K != Node::KEmptyName)
                     {
-                        db.names.back().first += "::" + name;
-                        db.subs.push_back(typename C::sub_type(1, db.names.back(), db.names.get_allocator()));
+                        db.Names.back() = db.make<QualifiedName>(
+                            db.Names.back(), name);
+                        db.Subs.pushSubstitution(db.Names.back());
                     }
                     else
-                        db.names.back().first = name;
+                        db.Names.back() = name;
                     pop_subs = true;
                     t0 = t1;
                 }
@@ -3997,15 +5377,16 @@ parse_nested_name(const char* first, const char* last, C& db,
                 t1 = parse_template_param(t0, last, db);
                 if (t1 != t0 && t1 != last)
                 {
-                    auto name = db.names.back().move_full();
-                    db.names.pop_back();
-                    if (db.names.empty())
+                    if (db.Names.size() < 2)
                         return first;
-                    if (!db.names.back().first.empty())
-                        db.names.back().first += "::" + name;
+                    auto name = db.Names.back();
+                    db.Names.pop_back();
+                    if (db.Names.back()->K != Node::KEmptyName)
+                        db.Names.back() =
+                            db.make<QualifiedName>(db.Names.back(), name);
                     else
-                        db.names.back().first = name;
-                    db.subs.push_back(typename C::sub_type(1, db.names.back(), db.names.get_allocator()));
+                        db.Names.back() = name;
+                    db.Subs.pushSubstitution(db.Names.back());
                     pop_subs = true;
                     t0 = t1;
                 }
@@ -4018,15 +5399,16 @@ parse_nested_name(const char* first, const char* last, C& db,
                 t1 = parse_decltype(t0, last, db);
                 if (t1 != t0 && t1 != last)
                 {
-                    auto name = db.names.back().move_full();
-                    db.names.pop_back();
-                    if (db.names.empty())
+                    if (db.Names.size() < 2)
                         return first;
-                    if (!db.names.back().first.empty())
-                        db.names.back().first += "::" + name;
+                    auto name = db.Names.back();
+                    db.Names.pop_back();
+                    if (db.Names.back()->K != Node::KEmptyName)
+                        db.Names.back() =
+                            db.make<QualifiedName>(db.Names.back(), name);
                     else
-                        db.names.back().first = name;
-                    db.subs.push_back(typename C::sub_type(1, db.names.back(), db.names.get_allocator()));
+                        db.Names.back() = name;
+                    db.Subs.pushSubstitution(db.Names.back());
                     pop_subs = true;
                     t0 = t1;
                 }
@@ -4037,12 +5419,13 @@ parse_nested_name(const char* first, const char* last, C& db,
                 t1 = parse_template_args(t0, last, db);
                 if (t1 != t0 && t1 != last)
                 {
-                    auto name = db.names.back().move_full();
-                    db.names.pop_back();
-                    if (db.names.empty())
+                    if (db.Names.size() < 2)
                         return first;
-                    db.names.back().first += name;
-                    db.subs.push_back(typename C::sub_type(1, db.names.back(), db.names.get_allocator()));
+                    auto name = db.Names.back();
+                    db.Names.pop_back();
+                    db.Names.back() = db.make<NameWithTemplateArgs>(
+                        db.Names.back(), name);
+                    db.Subs.pushSubstitution(db.Names.back());
                     t0 = t1;
                     component_ends_with_template_args = true;
                 }
@@ -4058,15 +5441,16 @@ parse_nested_name(const char* first, const char* last, C& db,
                 t1 = parse_unqualified_name(t0, last, db);
                 if (t1 != t0 && t1 != last)
                 {
-                    auto name = db.names.back().move_full();
-                    db.names.pop_back();
-                    if (db.names.empty())
+                    if (db.Names.size() < 2)
                         return first;
-                    if (!db.names.back().first.empty())
-                        db.names.back().first += "::" + name;
+                    auto name = db.Names.back();
+                    db.Names.pop_back();
+                    if (db.Names.back()->K != Node::KEmptyName)
+                        db.Names.back() =
+                            db.make<QualifiedName>(db.Names.back(), name);
                     else
-                        db.names.back().first = name;
-                    db.subs.push_back(typename C::sub_type(1, db.names.back(), db.names.get_allocator()));
+                        db.Names.back() = name;
+                    db.Subs.pushSubstitution(db.Names.back());
                     pop_subs = true;
                     t0 = t1;
                 }
@@ -4075,9 +5459,9 @@ parse_nested_name(const char* first, const char* last, C& db,
             }
         }
         first = t0 + 1;
-        db.cv = cv;
-        if (pop_subs && !db.subs.empty())
-            db.subs.pop_back();
+        db.CV = cv;
+        if (pop_subs && !db.Subs.empty())
+            db.Subs.popPack();
         if (ends_with_template_args)
             *ends_with_template_args = component_ends_with_template_args;
     }
@@ -4126,9 +5510,8 @@ parse_discriminator(const char* first, const char* last)
 //              := Z <function encoding> E s [<discriminator>]
 //              := Z <function encoding> Ed [ <parameter number> ] _ <entity name>
 
-template <class C>
 const char*
-parse_local_name(const char* first, const char* last, C& db,
+parse_local_name(const char* first, const char* last, Db& db,
                  bool* ends_with_template_args)
 {
     if (first != last && *first == 'Z')
@@ -4140,9 +5523,10 @@ parse_local_name(const char* first, const char* last, C& db,
             {
             case 's':
                 first = parse_discriminator(t+1, last);
-                if (db.names.empty())
+                if (db.Names.empty())
                     return first;
-                db.names.back().first.append("::string literal");
+                db.Names.back() = db.make<QualifiedName>(
+                    db.Names.back(), db.make<NameType>("string literal"));
                 break;
             case 'd':
                 if (++t != last)
@@ -4155,18 +5539,18 @@ parse_local_name(const char* first, const char* last, C& db,
                                         ends_with_template_args);
                         if (t1 != t)
                         {
-                            if (db.names.size() < 2)
+                            if (db.Names.size() < 2)
                                 return first;
-                            auto name = db.names.back().move_full();
-                            db.names.pop_back();
-                            if (db.names.empty())
+                            auto name = db.Names.back();
+                            db.Names.pop_back();
+                            if (db.Names.empty())
                                 return first;
-                            db.names.back().first.append("::");
-                            db.names.back().first.append(name);
+                            db.Names.back() =
+                                db.make<QualifiedName>(db.Names.back(), name);
                             first = t1;
                         }
-                        else if (!db.names.empty())
-                            db.names.pop_back();
+                        else if (!db.Names.empty())
+                            db.Names.pop_back();
                     }
                 }
                 break;
@@ -4178,17 +5562,17 @@ parse_local_name(const char* first, const char* last, C& db,
                     {
                         // parse but ignore discriminator
                         first = parse_discriminator(t1, last);
-                        if (db.names.size() < 2)
+                        if (db.Names.size() < 2)
                             return first;
-                        auto name = db.names.back().move_full();
-                        db.names.pop_back();
-                        if (db.names.empty())
+                        auto name = db.Names.back();
+                        db.Names.pop_back();
+                        if (db.Names.empty())
                             return first;
-                        db.names.back().first.append("::");
-                        db.names.back().first.append(name);
+                        db.Names.back() =
+                            db.make<QualifiedName>(db.Names.back(), name);
                     }
-                    else if (!db.names.empty())
-                        db.names.pop_back();
+                    else if (!db.Names.empty())
+                        db.Names.pop_back();
                 }
                 break;
             }
@@ -4205,9 +5589,8 @@ parse_local_name(const char* first, const char* last, C& db,
 // <unscoped-template-name> ::= <unscoped-name>
 //                          ::= <substitution>
 
-template <class C>
 const char*
-parse_name(const char* first, const char* last, C& db,
+parse_name(const char* first, const char* last, Db& db,
            bool* ends_with_template_args)
 {
     if (last - first >= 2)
@@ -4241,20 +5624,22 @@ parse_name(const char* first, const char* last, C& db,
             {
                 if (t1 != last && *t1 == 'I')  // <unscoped-template-name> <template-args>
                 {
-                    if (db.names.empty())
+                    if (db.Names.empty())
                         return first;
-                    db.subs.push_back(typename C::sub_type(1, db.names.back(), db.names.get_allocator()));
+                    db.Subs.pushSubstitution(db.Names.back());
                     t0 = t1;
                     t1 = parse_template_args(t0, last, db);
                     if (t1 != t0)
                     {
-                        if (db.names.size() < 2)
+                        if (db.Names.size() < 2)
                             return first;
-                        auto tmp = db.names.back().move_full();
-                        db.names.pop_back();
-                        if (db.names.empty())
+                        auto tmp = db.Names.back();
+                        db.Names.pop_back();
+                        if (db.Names.empty())
                             return first;
-                        db.names.back().first += tmp;
+                        db.Names.back() =
+                            db.make<NameWithTemplateArgs>(
+                                db.Names.back(), tmp);
                         first = t1;
                         if (ends_with_template_args)
                             *ends_with_template_args = true;
@@ -4272,13 +5657,15 @@ parse_name(const char* first, const char* last, C& db,
                     t1 = parse_template_args(t0, last, db);
                     if (t1 != t0)
                     {
-                        if (db.names.size() < 2)
+                        if (db.Names.size() < 2)
                             return first;
-                        auto tmp = db.names.back().move_full();
-                        db.names.pop_back();
-                        if (db.names.empty())
+                        auto tmp = db.Names.back();
+                        db.Names.pop_back();
+                        if (db.Names.empty())
                             return first;
-                        db.names.back().first += tmp;
+                        db.Names.back() =
+                            db.make<NameWithTemplateArgs>(
+                                db.Names.back(), tmp);
                         first = t1;
                         if (ends_with_template_args)
                             *ends_with_template_args = true;
@@ -4343,12 +5730,13 @@ parse_call_offset(const char* first, const char* last)
 //                    # base is the nominal target function of thunk
 //                ::= GV <object name> # Guard variable for one-time initialization
 //                                     # No <type>
+//                ::= TW <object name> # Thread-local wrapper
+//                ::= TH <object name> # Thread-local initialization
 //      extension ::= TC <first type> <number> _ <second type> # construction vtable for second-in-first
 //      extension ::= GR <object name> # reference temporary for object
 
-template <class C>
 const char*
-parse_special_name(const char* first, const char* last, C& db)
+parse_special_name(const char* first, const char* last, Db& db)
 {
     if (last - first > 2)
     {
@@ -4363,9 +5751,10 @@ parse_special_name(const char* first, const char* last, C& db)
                 t = parse_type(first+2, last, db);
                 if (t != first+2)
                 {
-                    if (db.names.empty())
+                    if (db.Names.empty())
                         return first;
-                    db.names.back().first.insert(0, "vtable for ");
+                    db.Names.back() =
+                        db.make<SpecialName>("vtable for ", db.Names.back());
                     first = t;
                 }
                 break;
@@ -4374,9 +5763,10 @@ parse_special_name(const char* first, const char* last, C& db)
                 t = parse_type(first+2, last, db);
                 if (t != first+2)
                 {
-                    if (db.names.empty())
+                    if (db.Names.empty())
                         return first;
-                    db.names.back().first.insert(0, "VTT for ");
+                    db.Names.back() =
+                        db.make<SpecialName>("VTT for ", db.Names.back());
                     first = t;
                 }
                 break;
@@ -4385,9 +5775,10 @@ parse_special_name(const char* first, const char* last, C& db)
                 t = parse_type(first+2, last, db);
                 if (t != first+2)
                 {
-                    if (db.names.empty())
+                    if (db.Names.empty())
                         return first;
-                    db.names.back().first.insert(0, "typeinfo for ");
+                    db.Names.back() =
+                        db.make<SpecialName>("typeinfo for ", db.Names.back());
                     first = t;
                 }
                 break;
@@ -4396,9 +5787,10 @@ parse_special_name(const char* first, const char* last, C& db)
                 t = parse_type(first+2, last, db);
                 if (t != first+2)
                 {
-                    if (db.names.empty())
+                    if (db.Names.empty())
                         return first;
-                    db.names.back().first.insert(0, "typeinfo name for ");
+                    db.Names.back() =
+                        db.make<SpecialName>("typeinfo name for ", db.Names.back());
                     first = t;
                 }
                 break;
@@ -4414,9 +5806,11 @@ parse_special_name(const char* first, const char* last, C& db)
                 t = parse_encoding(t1, last, db);
                 if (t != t1)
                 {
-                    if (db.names.empty())
+                    if (db.Names.empty())
                         return first;
-                    db.names.back().first.insert(0, "covariant return thunk to ");
+                    db.Names.back() =
+                        db.make<SpecialName>("covariant return thunk to ",
+                                              db.Names.back());
                     first = t;
                 }
               }
@@ -4432,20 +5826,44 @@ parse_special_name(const char* first, const char* last, C& db)
                         const char* t1 = parse_type(++t0, last, db);
                         if (t1 != t0)
                         {
-                            if (db.names.size() < 2)
+                            if (db.Names.size() < 2)
                                 return first;
-                            auto left = db.names.back().move_full();
-                            db.names.pop_back();
-                            if (db.names.empty())
+                            auto left = db.Names.back();
+                            db.Names.pop_back();
+                            if (db.Names.empty())
                                 return first;
-                            db.names.back().first = "construction vtable for " +
-                                                    std::move(left) + "-in-" +
-                                                    db.names.back().move_full();
+                            db.Names.back() = db.make<CtorVtableSpecialName>(
+                                left, db.Names.back());
                             first = t1;
                         }
                     }
                 }
                 break;
+            case 'W':
+                // TW <object name> # Thread-local wrapper
+                t = parse_name(first + 2, last, db);
+                if (t != first + 2) 
+                {
+                    if (db.Names.empty())
+                        return first;
+                    db.Names.back() =
+                        db.make<SpecialName>("thread-local wrapper routine for ",
+                                              db.Names.back());
+                    first = t;
+                }
+                break;
+            case 'H':
+                //TH <object name> # Thread-local initialization
+                t = parse_name(first + 2, last, db);
+                if (t != first + 2) 
+                {
+                    if (db.Names.empty())
+                        return first;
+                    db.Names.back() = db.make<SpecialName>(
+                        "thread-local initialization routine for ", db.Names.back());
+                    first = t;
+                }
+                break;
             default:
                 // T <call-offset> <base encoding>
                 {
@@ -4455,16 +5873,20 @@ parse_special_name(const char* first, const char* last, C& db)
                 t = parse_encoding(t0, last, db);
                 if (t != t0)
                 {
-                    if (db.names.empty())
+                    if (db.Names.empty())
                         return first;
                     if (first[1] == 'v')
                     {
-                        db.names.back().first.insert(0, "virtual thunk to ");
+                        db.Names.back() =
+                            db.make<SpecialName>("virtual thunk to ",
+                                                  db.Names.back());
                         first = t;
                     }
                     else
                     {
-                        db.names.back().first.insert(0, "non-virtual thunk to ");
+                        db.Names.back() =
+                            db.make<SpecialName>("non-virtual thunk to ",
+                                                  db.Names.back());
                         first = t;
                     }
                 }
@@ -4480,9 +5902,10 @@ parse_special_name(const char* first, const char* last, C& db)
                 t = parse_name(first+2, last, db);
                 if (t != first+2)
                 {
-                    if (db.names.empty())
+                    if (db.Names.empty())
                         return first;
-                    db.names.back().first.insert(0, "guard variable for ");
+                    db.Names.back() =
+                        db.make<SpecialName>("guard variable for ", db.Names.back());
                     first = t;
                 }
                 break;
@@ -4491,9 +5914,11 @@ parse_special_name(const char* first, const char* last, C& db)
                 t = parse_name(first+2, last, db);
                 if (t != first+2)
                 {
-                    if (db.names.empty())
+                    if (db.Names.empty())
                         return first;
-                    db.names.back().first.insert(0, "reference temporary for ");
+                    db.Names.back() =
+                        db.make<SpecialName>("reference temporary for ",
+                                              db.Names.back());
                     first = t;
                 }
                 break;
@@ -4528,17 +5953,18 @@ public:
 //            ::= <data name>
 //            ::= <special-name>
 
-template <class C>
 const char*
-parse_encoding(const char* first, const char* last, C& db)
+parse_encoding(const char* first, const char* last, Db& db)
 {
     if (first != last)
     {
-        save_value<decltype(db.encoding_depth)> su(db.encoding_depth);
-        ++db.encoding_depth;
-        save_value<decltype(db.tag_templates)> sb(db.tag_templates);
-        if (db.encoding_depth > 1)
-            db.tag_templates = true;
+        save_value<decltype(db.EncodingDepth)> su(db.EncodingDepth);
+        ++db.EncodingDepth;
+        save_value<decltype(db.TagTemplates)> sb(db.TagTemplates);
+        if (db.EncodingDepth > 1)
+            db.TagTemplates = true;
+        save_value<decltype(db.ParsedCtorDtorCV)> sp(db.ParsedCtorDtorCV);
+        db.ParsedCtorDtorCV = false;
         switch (*first)
         {
         case 'G':
@@ -4550,96 +5976,72 @@ parse_encoding(const char* first, const char* last, C& db)
             bool ends_with_template_args = false;
             const char* t = parse_name(first, last, db,
                                        &ends_with_template_args);
-            unsigned cv = db.cv;
-            unsigned ref = db.ref;
+            if (db.Names.empty())
+                return first;
+            Qualifiers cv = db.CV;
+            FunctionRefQual ref = db.RefQuals;
             if (t != first)
             {
                 if (t != last && *t != 'E' && *t != '.')
                 {
-                    save_value<bool> sb2(db.tag_templates);
-                    db.tag_templates = false;
+                    save_value<bool> sb2(db.TagTemplates);
+                    db.TagTemplates = false;
                     const char* t2;
-                    typename C::String ret2;
-                    if (db.names.empty())
+                    if (db.Names.empty())
                         return first;
-                    const typename C::String& nm = db.names.back().first;
-                    if (nm.empty())
+                    if (!db.Names.back())
                         return first;
-                    if (!db.parsed_ctor_dtor_cv && ends_with_template_args)
+                    Node* return_type = nullptr;
+                    if (!db.ParsedCtorDtorCV && ends_with_template_args)
                     {
                         t2 = parse_type(t, last, db);
                         if (t2 == t)
                             return first;
-                        if (db.names.size() < 2)
-                            return first;
-                        auto ret1 = std::move(db.names.back().first);
-                        ret2 = std::move(db.names.back().second);
-                        if (ret2.empty())
-                            ret1 += ' ';
-                        db.names.pop_back();
-                        if (db.names.empty())
+                        if (db.Names.size() < 1)
                             return first;
-
-                        db.names.back().first.insert(0, ret1);
+                        return_type = db.Names.back();
+                        db.Names.pop_back();
                         t = t2;
                     }
-                    db.names.back().first += '(';
+
+                    Node* result = nullptr;
+
                     if (t != last && *t == 'v')
                     {
                         ++t;
+                        if (db.Names.empty())
+                            return first;
+                        Node* name = db.Names.back();
+                        db.Names.pop_back();
+                        result = db.make<TopLevelFunctionDecl>(
+                            return_type, name, NodeArray());
                     }
                     else
                     {
-                        bool first_arg = true;
+                        size_t params_begin = db.Names.size();
                         while (true)
                         {
-                            size_t k0 = db.names.size();
                             t2 = parse_type(t, last, db);
-                            size_t k1 = db.names.size();
                             if (t2 == t)
                                 break;
-                            if (k1 > k0)
-                            {
-                                typename C::String tmp;
-                                for (size_t k = k0; k < k1; ++k)
-                                {
-                                    if (!tmp.empty())
-                                        tmp += ", ";
-                                    tmp += db.names[k].move_full();
-                                }
-                                for (size_t k = k0; k < k1; ++k) {
-                                    if (db.names.empty())
-                                        return first;
-                                    db.names.pop_back();
-                                }
-                                if (!tmp.empty())
-                                {
-                                    if (db.names.empty())
-                                        return first;
-                                    if (!first_arg)
-                                        db.names.back().first += ", ";
-                                    else
-                                        first_arg = false;
-                                    db.names.back().first += tmp;
-                                }
-                            }
                             t = t2;
                         }
+                        if (db.Names.size() < params_begin)
+                            return first;
+                        NodeArray params =
+                            db.popTrailingNodeArray(params_begin);
+                        if (db.Names.empty())
+                            return first;
+                        Node* name = db.Names.back();
+                        db.Names.pop_back();
+                        result = db.make<TopLevelFunctionDecl>(
+                            return_type, name, params);
                     }
-                    if (db.names.empty())
-                        return first;
-                    db.names.back().first += ')';
-                    if (cv & 1)
-                        db.names.back().first.append(" const");
-                    if (cv & 2)
-                        db.names.back().first.append(" volatile");
-                    if (cv & 4)
-                        db.names.back().first.append(" restrict");
-                    if (ref == 1)
-                        db.names.back().first.append(" &");
-                    else if (ref == 2)
-                        db.names.back().first.append(" &&");
-                    db.names.back().first += ret2;
+                    if (ref != FrefQualNone)
+                        result = db.make<FunctionRefQualType>(result, ref);
+                    if (cv != QualNone)
+                        result = db.make<FunctionQualType>(result, cv);
+                    db.Names.push_back(result);
                     first = t;
                 }
                 else
@@ -4656,12 +6058,12 @@ parse_encoding(const char* first, const char* last, C& db)
 // _block_invoke<decimal-digit>+
 // _block_invoke_<decimal-digit>+
 
-template <class C>
 const char*
-parse_block_invoke(const char* first, const char* last, C& db)
+parse_block_invoke(const char* first, const char* last, Db& db)
 {
     if (last - first >= 13)
     {
+        // FIXME: strcmp?
         const char test[] = "_block_invoke";
         const char* t = first;
         for (int i = 0; i < 13; ++i, ++t)
@@ -4682,9 +6084,11 @@ parse_block_invoke(const char* first, const char* last, C& db)
             while (t != last && isdigit(*t))
                 ++t;
         }
-        if (db.names.empty())
+        if (db.Names.empty())
             return first;
-        db.names.back().first.insert(0, "invocation function for block in ");
+        db.Names.back() =
+            db.make<SpecialName>("invocation function for block in ",
+                                  db.Names.back());
         first = t;
     }
     return first;
@@ -4693,15 +6097,15 @@ parse_block_invoke(const char* first, const char* last, C& db)
 // extension
 // <dot-suffix> := .<anything and everything>
 
-template <class C>
 const char*
-parse_dot_suffix(const char* first, const char* last, C& db)
+parse_dot_suffix(const char* first, const char* last, Db& db)
 {
     if (first != last && *first == '.')
     {
-        if (db.names.empty())
+        if (db.Names.empty())
             return first;
-        db.names.back().first += " (" + typename C::String(first, last) + ")";
+        db.Names.back() =
+            db.make<DotSuffix>(db.Names.back(), StringView(first, last));
         first = last;
     }
     return first;
@@ -4713,9 +6117,8 @@ parse_dot_suffix(const char* first, const char* last, C& db)
 // <mangled-name> ::= _Z<encoding>
 //                ::= <type>
 
-template <class C>
 void
-demangle(const char* first, const char* last, C& db, int& status)
+demangle(const char* first, const char* last, Db& db, int& status)
 {
     if (first >= last)
     {
@@ -4758,216 +6161,10 @@ demangle(const char* first, const char* last, C& db, int& status)
         if (t != last)
             status = invalid_mangled_name;
     }
-    if (status == success && db.names.empty())
+    if (status == success && db.Names.empty())
         status = invalid_mangled_name;
 }
 
-template <std::size_t N>
-class arena
-{
-    static const std::size_t alignment = 16;
-    alignas(alignment) char buf_[N];
-    char* ptr_;
-
-    std::size_t 
-    align_up(std::size_t n) noexcept
-        {return (n + (alignment-1)) & ~(alignment-1);}
-
-    bool
-    pointer_in_buffer(char* p) noexcept
-        {return buf_ <= p && p <= buf_ + N;}
-
-public:
-    arena() noexcept : ptr_(buf_) {}
-    ~arena() {ptr_ = nullptr;}
-    arena(const arena&) = delete;
-    arena& operator=(const arena&) = delete;
-
-    char* allocate(std::size_t n);
-    void deallocate(char* p, std::size_t n) noexcept;
-
-    static constexpr std::size_t size() {return N;}
-    std::size_t used() const {return static_cast<std::size_t>(ptr_ - buf_);}
-    void reset() {ptr_ = buf_;}
-};
-
-template <std::size_t N>
-char*
-arena<N>::allocate(std::size_t n)
-{
-    n = align_up(n);
-    if (static_cast<std::size_t>(buf_ + N - ptr_) >= n)
-    {
-        char* r = ptr_;
-        ptr_ += n;
-        return r;
-    }
-    return static_cast<char*>(std::malloc(n));
-}
-
-template <std::size_t N>
-void
-arena<N>::deallocate(char* p, std::size_t n) noexcept
-{
-    if (pointer_in_buffer(p))
-    {
-        n = align_up(n);
-        if (p + n == ptr_)
-            ptr_ = p;
-    }
-    else
-        std::free(p);
-}
-
-template <class T, std::size_t N>
-class short_alloc
-{
-    arena<N>& a_;
-public:
-    typedef T value_type;
-
-public:
-    template <class _Up> struct rebind {typedef short_alloc<_Up, N> other;};
-
-    short_alloc(arena<N>& a) noexcept : a_(a) {}
-    template <class U>
-        short_alloc(const short_alloc<U, N>& a) noexcept
-            : a_(a.a_) {}
-    short_alloc(const short_alloc&) = default;
-    short_alloc& operator=(const short_alloc&) = delete;
-
-    T* allocate(std::size_t n)
-    {
-        return reinterpret_cast<T*>(a_.allocate(n*sizeof(T)));
-    }
-    void deallocate(T* p, std::size_t n) noexcept
-    {
-        a_.deallocate(reinterpret_cast<char*>(p), n*sizeof(T));
-    }
-
-    template <class T1, std::size_t N1, class U, std::size_t M>
-    friend
-    bool
-    operator==(const short_alloc<T1, N1>& x, const short_alloc<U, M>& y) noexcept;
-
-    template <class U, std::size_t M> friend class short_alloc;
-};
-
-template <class T, std::size_t N, class U, std::size_t M>
-inline
-bool
-operator==(const short_alloc<T, N>& x, const short_alloc<U, M>& y) noexcept
-{
-    return N == M && &x.a_ == &y.a_;
-}
-
-template <class T, std::size_t N, class U, std::size_t M>
-inline
-bool
-operator!=(const short_alloc<T, N>& x, const short_alloc<U, M>& y) noexcept
-{
-    return !(x == y);
-}
-
-template <class T>
-class malloc_alloc
-{
-public:
-    typedef T value_type;
-    typedef T& reference;
-    typedef const T& const_reference;
-    typedef T* pointer;
-    typedef const T* const_pointer;
-    typedef std::size_t size_type;
-    typedef std::ptrdiff_t difference_type;
-
-    malloc_alloc() = default;
-    template <class U> malloc_alloc(const malloc_alloc<U>&) noexcept {}
-
-    T* allocate(std::size_t n)
-    {
-        return static_cast<T*>(std::malloc(n*sizeof(T)));
-    }
-    void deallocate(T* p, std::size_t) noexcept
-    {
-        std::free(p);
-    }
-
-    template <class U> struct rebind { using other = malloc_alloc<U>; };
-    template <class U, class... Args>
-    void construct(U* p, Args&&... args)
-    {
-        ::new ((void*)p) U(std::forward<Args>(args)...);
-    }
-    void destroy(T* p)
-    {
-        p->~T();
-    }
-};
-
-template <class T, class U>
-inline
-bool
-operator==(const malloc_alloc<T>&, const malloc_alloc<U>&) noexcept
-{
-    return true;
-}
-
-template <class T, class U>
-inline
-bool
-operator!=(const malloc_alloc<T>& x, const malloc_alloc<U>& y) noexcept
-{
-    return !(x == y);
-}
-
-const size_t bs = 4 * 1024;
-template <class T> using Alloc = short_alloc<T, bs>;
-template <class T> using Vector = std::vector<T, Alloc<T>>;
-
-template <class StrT>
-struct string_pair
-{
-    StrT first;
-    StrT second;
-
-    string_pair() = default;
-    string_pair(StrT f) : first(std::move(f)) {}
-    string_pair(StrT f, StrT s)
-        : first(std::move(f)), second(std::move(s)) {}
-    template <size_t N>
-        string_pair(const char (&s)[N]) : first(s, N-1) {}
-
-    size_t size() const {return first.size() + second.size();}
-    StrT full() const {return first + second;}
-    StrT move_full() {return std::move(first) + std::move(second);}
-};
-
-struct Db
-{
-    typedef std::basic_string<char, std::char_traits<char>,
-                              malloc_alloc<char>> String;
-    typedef Vector<string_pair<String>> sub_type;
-    typedef Vector<sub_type> template_param_type;
-    sub_type names;
-    template_param_type subs;
-    Vector<template_param_type> template_param;
-    unsigned cv;
-    unsigned ref;
-    unsigned encoding_depth;
-    bool parsed_ctor_dtor_cv;
-    bool tag_templates;
-    bool fix_forward_references;
-    bool try_to_parse_template_args;
-
-    template <size_t N>
-    Db(arena<N>& ar) :
-        names(ar),
-        subs(0, names, ar),
-        template_param(0, subs, ar)
-    {}
-};
-
 }  // unnamed namespace
 
 extern "C" _LIBCXXABI_FUNC_VIS char *
@@ -4978,56 +6175,44 @@ __cxa_demangle(const char *mangled_name, char *buf, size_t *n, int *status) {
             *status = invalid_args;
         return nullptr;
     }
+
     size_t internal_size = buf != nullptr ? *n : 0;
-    arena<bs> a;
-    Db db(a);
-    db.cv = 0;
-    db.ref = 0;
-    db.encoding_depth = 0;
-    db.parsed_ctor_dtor_cv = false;
-    db.tag_templates = true;
-    db.template_param.emplace_back(a);
-    db.fix_forward_references = false;
-    db.try_to_parse_template_args = true;
+    Db db;
     int internal_status = success;
     size_t len = std::strlen(mangled_name);
     demangle(mangled_name, mangled_name + len, db,
              internal_status);
-    if (internal_status == success && db.fix_forward_references &&
-           !db.template_param.empty() && !db.template_param.front().empty())
+
+    if (internal_status == success && db.FixForwardReferences &&
+        !db.TemplateParams.empty())
     {
-        db.fix_forward_references = false;
-        db.tag_templates = false;
-        db.names.clear();
-        db.subs.clear();
+        db.FixForwardReferences = false;
+        db.TagTemplates = false;
+        db.Names.clear();
+        db.Subs.clear();
         demangle(mangled_name, mangled_name + len, db, internal_status);
-        if (db.fix_forward_references)
+        if (db.FixForwardReferences)
             internal_status = invalid_mangled_name;
     }
+
     if (internal_status == success)
     {
-        size_t sz = db.names.back().size() + 1;
-        if (sz > internal_size)
+        if (!buf)
         {
-            char* newbuf = static_cast<char*>(std::realloc(buf, sz));
-            if (newbuf == nullptr)
-            {
-                internal_status = memory_alloc_failure;
-                buf = nullptr;
-            }
-            else
-            {
-                buf = newbuf;
-                if (n != nullptr)
-                    *n = sz;
-            }
+            internal_size = 1024;
+            buf = static_cast<char*>(std::malloc(internal_size));
         }
-        if (buf != nullptr)
+
+        if (buf)
         {
-            db.names.back().first += db.names.back().second;
-            std::memcpy(buf, db.names.back().first.data(), sz-1);
-            buf[sz-1] = char(0);
+            OutputStream s(buf, internal_size);
+            db.Names.back()->print(s);
+            s += '\0';
+            if (n) *n = s.getCurrentPosition();
+            buf = s.getBuffer();
         }
+        else
+            internal_status = memory_alloc_failure;
     }
     else
         buf = nullptr;
diff --git a/lib/libcxxabi/src/cxa_exception.cpp b/lib/libcxxabi/src/cxa_exception.cpp
index 50d1a468cea..d5230cdc7d9 100644
--- a/lib/libcxxabi/src/cxa_exception.cpp
+++ b/lib/libcxxabi/src/cxa_exception.cpp
@@ -11,17 +11,17 @@
 //  
 //===----------------------------------------------------------------------===//
 
-#include "config.h"
 #include "cxxabi.h"
 
 #include <exception>        // for std::terminate
-#include <cstdlib>          // for malloc, free
 #include <cstring>          // for memset
-#if !LIBCXXABI_HAS_NO_THREADS
-#  include <pthread.h>      // for fallback_malloc.ipp's mutexes
-#endif
 #include "cxa_exception.hpp"
 #include "cxa_handlers.hpp"
+#include "fallback_malloc.h"
+
+#if __has_feature(address_sanitizer)
+extern "C" void __asan_handle_no_return(void);
+#endif
 
 // +---------------------------+-----------------------------+---------------+
 // | __cxa_exception           | _Unwind_Exception CLNGC++\0 | thrown object |
@@ -36,8 +36,6 @@
 
 namespace __cxxabiv1 {
 
-#pragma GCC visibility push(default)
-
 //  Utility routines
 static
 inline
@@ -68,12 +66,16 @@ cxa_exception_from_exception_unwind_exception(_Unwind_Exception* unwind_exceptio
     return cxa_exception_from_thrown_object(unwind_exception + 1 );
 }
 
-static
-inline
-size_t
-cxa_exception_size_from_exception_thrown_size(size_t size)
-{
-    return size + sizeof (__cxa_exception);
+// Round s up to next multiple of a.
+static inline
+size_t aligned_allocation_size(size_t s, size_t a) {
+    return (s + a - 1) & ~(a - 1);
+}
+
+static inline
+size_t cxa_exception_size_from_exception_thrown_size(size_t size) {
+    return aligned_allocation_size(size + sizeof (__cxa_exception),
+                                   alignof(__cxa_exception));
 }
 
 static void setExceptionClass(_Unwind_Exception* unwind_exception) {
@@ -104,20 +106,6 @@ static inline  int decrementHandlerCount(__cxa_exception *exception) {
     return --exception->handlerCount;
 }
 
-#include "fallback_malloc.ipp"
-
-//  Allocate some memory from _somewhere_
-static void *do_malloc(size_t size) {
-    void *ptr = std::malloc(size);
-    if (NULL == ptr) // if malloc fails, fall back to emergency stash
-        ptr = fallback_malloc(size);
-    return ptr;
-}
-
-static void do_free(void *ptr) {
-    is_fallback_ptr(ptr) ? fallback_free(ptr) : std::free(ptr);
-}
-
 /*
     If reason isn't _URC_FOREIGN_EXCEPTION_CAUGHT, then the terminateHandler
     stored in exc is called.  Otherwise the exceptionDestructor stored in 
@@ -137,7 +125,7 @@ exception_cleanup_func(_Unwind_Reason_Code reason, _Unwind_Exception* unwind_exc
     __cxa_decrement_exception_refcount(unwind_exception + 1);
 }
 
-static LIBCXXABI_NORETURN void failed_throw(__cxa_exception* exception_header) {
+static _LIBCXXABI_NORETURN void failed_throw(__cxa_exception* exception_header) {
 //  Section 2.5.3 says:
 //      * For purposes of this ABI, several things are considered exception handlers:
 //      ** A terminate() call due to a throw.
@@ -149,6 +137,28 @@ static LIBCXXABI_NORETURN void failed_throw(__cxa_exception* exception_header) {
     std::__terminate(exception_header->terminateHandler);
 }
 
+// Return the offset of the __cxa_exception header from the start of the
+// allocated buffer. If __cxa_exception's alignment is smaller than the maximum
+// useful alignment for the target machine, padding has to be inserted before
+// the header to ensure the thrown object that follows the header is
+// sufficiently aligned. This happens if _Unwind_exception isn't double-word
+// aligned (on Darwin, for example).
+static size_t get_cxa_exception_offset() {
+  struct S {
+  } __attribute__((aligned));
+
+  // Compute the maximum alignment for the target machine.
+  constexpr size_t alignment = std::alignment_of<S>::value;
+  constexpr size_t excp_size = sizeof(__cxa_exception);
+  constexpr size_t aligned_size =
+      (excp_size + alignment - 1) / alignment * alignment;
+  constexpr size_t offset = aligned_size - excp_size;
+  static_assert((offset == 0 ||
+                 std::alignment_of<_Unwind_Exception>::value < alignment),
+                "offset is non-zero only if _Unwind_Exception isn't aligned");
+  return offset;
+}
+
 extern "C" {
 
 //  Allocate a __cxa_exception object, and zero-fill it.
@@ -156,19 +166,30 @@ extern "C" {
 //  object. Zero-fill the object. If memory can't be allocated, call
 //  std::terminate. Return a pointer to the memory to be used for the
 //  user's exception object.
-_LIBCXXABI_FUNC_VIS void *__cxa_allocate_exception(size_t thrown_size) throw() {
+void *__cxa_allocate_exception(size_t thrown_size) throw() {
     size_t actual_size = cxa_exception_size_from_exception_thrown_size(thrown_size);
-    __cxa_exception* exception_header = static_cast<__cxa_exception*>(do_malloc(actual_size));
-    if (NULL == exception_header)
+
+    // Allocate extra space before the __cxa_exception header to ensure the
+    // start of the thrown object is sufficiently aligned.
+    size_t header_offset = get_cxa_exception_offset();
+    char *raw_buffer =
+        (char *)__aligned_malloc_with_fallback(header_offset + actual_size);
+    if (NULL == raw_buffer)
         std::terminate();
+    __cxa_exception *exception_header =
+        static_cast<__cxa_exception *>((void *)(raw_buffer + header_offset));
     std::memset(exception_header, 0, actual_size);
     return thrown_object_from_cxa_exception(exception_header);
 }
 
 
 //  Free a __cxa_exception object allocated with __cxa_allocate_exception.
-_LIBCXXABI_FUNC_VIS void __cxa_free_exception(void *thrown_object) throw() {
-    do_free(cxa_exception_from_thrown_object(thrown_object));
+void __cxa_free_exception(void *thrown_object) throw() {
+    // Compute the size of the padding before the header.
+    size_t header_offset = get_cxa_exception_offset();
+    char *raw_buffer =
+        ((char *)cxa_exception_from_thrown_object(thrown_object)) - header_offset;
+    __aligned_free_with_fallback((void *)raw_buffer);
 }
 
 
@@ -177,7 +198,7 @@ _LIBCXXABI_FUNC_VIS void __cxa_free_exception(void *thrown_object) throw() {
 //  Otherwise, it will work like __cxa_allocate_exception.
 void * __cxa_allocate_dependent_exception () {
     size_t actual_size = sizeof(__cxa_dependent_exception);
-    void *ptr = do_malloc(actual_size);
+    void *ptr = __aligned_malloc_with_fallback(actual_size);
     if (NULL == ptr)
         std::terminate();
     std::memset(ptr, 0, actual_size);
@@ -188,7 +209,7 @@ void * __cxa_allocate_dependent_exception () {
 //  This function shall free a dependent_exception.
 //  It does not affect the reference count of the primary exception.
 void __cxa_free_dependent_exception (void * dependent_exception) {
-    do_free(dependent_exception);
+    __aligned_free_with_fallback(dependent_exception);
 }
 
 
@@ -218,7 +239,7 @@ handler, _Unwind_RaiseException may return. In that case, __cxa_throw
 will call terminate, assuming that there was no handler for the
 exception.
 */
-_LIBCXXABI_FUNC_VIS LIBCXXABI_NORETURN void
+void
 __cxa_throw(void *thrown_object, std::type_info *tinfo, void (*dest)(void *)) {
     __cxa_eh_globals *globals = __cxa_get_globals();
     __cxa_exception* exception_header = cxa_exception_from_thrown_object(thrown_object);
@@ -232,6 +253,12 @@ __cxa_throw(void *thrown_object, std::type_info *tinfo, void (*dest)(void *)) {
     globals->uncaughtExceptions += 1;   // Not atomically, since globals are thread-local
 
     exception_header->unwindHeader.exception_cleanup = exception_cleanup_func;
+
+#if __has_feature(address_sanitizer)
+    // Inform the ASan runtime that now might be a good time to clean stuff up.
+    __asan_handle_no_return();
+#endif
+
 #ifdef __USING_SJLJ_EXCEPTIONS__
     _Unwind_SjLj_RaiseException(&exception_header->unwindHeader);
 #else
@@ -251,9 +278,8 @@ The adjusted pointer is computed by the personality routine during phase 1
 
   Requires:  exception is native
 */
-_LIBCXXABI_FUNC_VIS
 void *__cxa_get_exception_ptr(void *unwind_exception) throw() {
-#if LIBCXXABI_ARM_EHABI
+#if defined(_LIBCXXABI_ARM_EHABI)
     return reinterpret_cast<void*>(
         static_cast<_Unwind_Control_Block*>(unwind_exception)->barrier_cache.bitpattern[0]);
 #else
@@ -262,12 +288,11 @@ void *__cxa_get_exception_ptr(void *unwind_exception) throw() {
 #endif
 }
 
-#if LIBCXXABI_ARM_EHABI
+#if defined(_LIBCXXABI_ARM_EHABI)
 /*
 The routine to be called before the cleanup.  This will save __cxa_exception in
 __cxa_eh_globals, so that __cxa_end_cleanup() can recover later.
 */
-_LIBCXXABI_FUNC_VIS
 bool __cxa_begin_cleanup(void *unwind_arg) throw() {
     _Unwind_Exception* unwind_exception = static_cast<_Unwind_Exception*>(unwind_arg);
     __cxa_eh_globals* globals = __cxa_get_globals();
@@ -345,7 +370,7 @@ asm (
     "	bl	abort\n"
     "	.popsection"
 );
-#endif  // LIBCXXABI_ARM_EHABI
+#endif  // defined(_LIBCXXABI_ARM_EHABI)
     
 /*
 This routine can catch foreign or native exceptions.  If native, the exception
@@ -405,7 +430,7 @@ __cxa_begin_catch(void* unwind_arg) throw()
             globals->caughtExceptions = exception_header;
         }
         globals->uncaughtExceptions -= 1;   // Not atomically, since globals are thread-local
-#if LIBCXXABI_ARM_EHABI
+#if defined(_LIBCXXABI_ARM_EHABI)
         return reinterpret_cast<void*>(exception_header->unwindHeader.barrier_cache.bitpattern[0]);
 #else
         return exception_header->adjustedPtr;
@@ -439,7 +464,7 @@ For a foreign exception:
 * If it has been rethrown, there is nothing to do.
 * Otherwise delete the exception and pop the catch stack to empty.
 */
-_LIBCXXABI_FUNC_VIS void __cxa_end_catch() {
+void __cxa_end_catch() {
   static_assert(sizeof(__cxa_exception) == sizeof(__cxa_dependent_exception),
                 "sizeof(__cxa_exception) must be equal to "
                 "sizeof(__cxa_dependent_exception)");
@@ -516,7 +541,7 @@ _LIBCXXABI_FUNC_VIS void __cxa_end_catch() {
 // Note:  exception_header may be masquerading as a __cxa_dependent_exception
 //        and that's ok.  exceptionType is there too.
 //        However watch out for foreign exceptions.  Return null for them.
-_LIBCXXABI_FUNC_VIS std::type_info *__cxa_current_exception_type() {
+std::type_info *__cxa_current_exception_type() {
 //  get the current exception
     __cxa_eh_globals *globals = __cxa_get_globals_fast();
     if (NULL == globals)
@@ -541,7 +566,7 @@ If the exception is native:
   Note:  exception_header may be masquerading as a __cxa_dependent_exception
          and that's ok.
 */
-_LIBCXXABI_FUNC_VIS LIBCXXABI_NORETURN void __cxa_rethrow() {
+void __cxa_rethrow() {
     __cxa_eh_globals* globals = __cxa_get_globals();
     __cxa_exception* exception_header = globals->caughtExceptions;
     if (NULL == exception_header)
@@ -586,7 +611,7 @@ _LIBCXXABI_FUNC_VIS LIBCXXABI_NORETURN void __cxa_rethrow() {
 
     Requires:  If thrown_object is not NULL, it is a native exception.
 */
-_LIBCXXABI_FUNC_VIS void
+void
 __cxa_increment_exception_refcount(void *thrown_object) throw() {
     if (thrown_object != NULL )
     {
@@ -603,7 +628,7 @@ __cxa_increment_exception_refcount(void *thrown_object) throw() {
 
     Requires:  If thrown_object is not NULL, it is a native exception.
 */
-_LIBCXXABI_FUNC_VIS void
+void
 __cxa_decrement_exception_refcount(void *thrown_object) throw() {
     if (thrown_object != NULL )
     {
@@ -627,7 +652,7 @@ __cxa_decrement_exception_refcount(void *thrown_object) throw() {
     been no exceptions thrown, ever, on this thread, we can return NULL without 
     the need to allocate the exception-handling globals.
 */
-_LIBCXXABI_FUNC_VIS void *__cxa_current_primary_exception() throw() {
+void *__cxa_current_primary_exception() throw() {
 //  get the current exception
     __cxa_eh_globals* globals = __cxa_get_globals_fast();
     if (NULL == globals)
@@ -713,6 +738,4 @@ __cxa_uncaught_exceptions() throw()
 
 }  // extern "C"
 
-#pragma GCC visibility pop
-
 }  // abi
diff --git a/lib/libcxxabi/src/cxa_exception.hpp b/lib/libcxxabi/src/cxa_exception.hpp
index 6e68f985389..c8b0fb1678e 100644
--- a/lib/libcxxabi/src/cxa_exception.hpp
+++ b/lib/libcxxabi/src/cxa_exception.hpp
@@ -15,19 +15,17 @@
 #define _CXA_EXCEPTION_H
 
 #include <exception> // for std::unexpected_handler and std::terminate_handler
-#include <cxxabi.h>
+#include "cxxabi.h"
 #include "unwind.h"
 
 namespace __cxxabiv1 {
 
-#pragma GCC visibility push(hidden)
-
 static const uint64_t kOurExceptionClass          = 0x434C4E47432B2B00; // CLNGC++\0
 static const uint64_t kOurDependentExceptionClass = 0x434C4E47432B2B01; // CLNGC++\1
 static const uint64_t get_vendor_and_language     = 0xFFFFFFFFFFFFFF00; // mask for CLNGC++
 
-struct __cxa_exception {
-#if defined(__LP64__) || LIBCXXABI_ARM_EHABI
+struct _LIBCXXABI_HIDDEN __cxa_exception {
+#if defined(__LP64__) || defined(_LIBCXXABI_ARM_EHABI)
     // This is a new field to support C++ 0x exception_ptr.
     // For binary compatibility it is at the start of this
     // struct which is prepended to the object thrown in
@@ -45,7 +43,7 @@ struct __cxa_exception {
 
     int handlerCount;
 
-#if LIBCXXABI_ARM_EHABI
+#if defined(_LIBCXXABI_ARM_EHABI)
     __cxa_exception* nextPropagatingException;
     int propagationCount;
 #else
@@ -56,21 +54,20 @@ struct __cxa_exception {
     void *adjustedPtr;
 #endif
 
-#if !defined(__LP64__) && !LIBCXXABI_ARM_EHABI
+#if !defined(__LP64__) && !defined(_LIBCXXABI_ARM_EHABI)
     // This is a new field to support C++ 0x exception_ptr.
     // For binary compatibility it is placed where the compiler
     // previously adding padded to 64-bit align unwindHeader.
     size_t referenceCount;
 #endif
-
     _Unwind_Exception unwindHeader;
 };
 
 // http://sourcery.mentor.com/archives/cxx-abi-dev/msg01924.html
 // The layout of this structure MUST match the layout of __cxa_exception, with
 // primaryException instead of referenceCount.
-struct __cxa_dependent_exception {
-#if defined(__LP64__) || LIBCXXABI_ARM_EHABI
+struct _LIBCXXABI_HIDDEN __cxa_dependent_exception {
+#if defined(__LP64__) || defined(_LIBCXXABI_ARM_EHABI)
     void* primaryException;
 #endif
 
@@ -83,7 +80,7 @@ struct __cxa_dependent_exception {
 
     int handlerCount;
 
-#if LIBCXXABI_ARM_EHABI
+#if defined(_LIBCXXABI_ARM_EHABI)
     __cxa_exception* nextPropagatingException;
     int propagationCount;
 #else
@@ -94,31 +91,25 @@ struct __cxa_dependent_exception {
     void *adjustedPtr;
 #endif
 
-#if !defined(__LP64__) && !LIBCXXABI_ARM_EHABI
+#if !defined(__LP64__) && !defined(_LIBCXXABI_ARM_EHABI)
     void* primaryException;
 #endif
-
     _Unwind_Exception unwindHeader;
 };
 
-struct __cxa_eh_globals {
+struct _LIBCXXABI_HIDDEN __cxa_eh_globals {
     __cxa_exception *   caughtExceptions;
     unsigned int        uncaughtExceptions;
-#if LIBCXXABI_ARM_EHABI
+#if defined(_LIBCXXABI_ARM_EHABI)
     __cxa_exception* propagatingExceptions;
 #endif
 };
 
-#pragma GCC visibility pop
-#pragma GCC visibility push(default)
-
-extern "C" __cxa_eh_globals * __cxa_get_globals      ();
-extern "C" __cxa_eh_globals * __cxa_get_globals_fast ();
-
-extern "C" void * __cxa_allocate_dependent_exception ();
-extern "C" void __cxa_free_dependent_exception (void * dependent_exception);
+extern "C" _LIBCXXABI_FUNC_VIS __cxa_eh_globals * __cxa_get_globals      ();
+extern "C" _LIBCXXABI_FUNC_VIS __cxa_eh_globals * __cxa_get_globals_fast ();
 
-#pragma GCC visibility pop
+extern "C" _LIBCXXABI_FUNC_VIS void * __cxa_allocate_dependent_exception ();
+extern "C" _LIBCXXABI_FUNC_VIS void __cxa_free_dependent_exception (void * dependent_exception);
 
 }  // namespace __cxxabiv1
 
diff --git a/lib/libcxxabi/src/cxa_exception_storage.cpp b/lib/libcxxabi/src/cxa_exception_storage.cpp
index a39b6db005f..c641e0225f8 100644
--- a/lib/libcxxabi/src/cxa_exception_storage.cpp
+++ b/lib/libcxxabi/src/cxa_exception_storage.cpp
@@ -13,9 +13,9 @@
 
 #include "cxa_exception.hpp"
 
-#include "config.h"
+#include <__threading_support>
 
-#if LIBCXXABI_HAS_NO_THREADS
+#if defined(_LIBCXXABI_HAS_NO_THREADS)
 
 namespace __cxxabiv1 {
 extern "C" {
@@ -44,28 +44,27 @@ extern "C" {
 
 #else
 
-#include <pthread.h>
-#include <cstdlib>          // for calloc, free
 #include "abort_message.h"
+#include "fallback_malloc.h"
 
-//  In general, we treat all pthread errors as fatal.
+//  In general, we treat all threading errors as fatal.
 //  We cannot call std::terminate() because that will in turn
 //  call __cxa_get_globals() and cause infinite recursion.
 
 namespace __cxxabiv1 {
 namespace {
-    pthread_key_t  key_;
-    pthread_once_t flag_ = PTHREAD_ONCE_INIT;
+    std::__libcpp_tls_key key_;
+    std::__libcpp_exec_once_flag flag_ = _LIBCPP_EXEC_ONCE_INITIALIZER;
 
-    void destruct_ (void *p) {
-        std::free ( p );
-        if ( 0 != ::pthread_setspecific ( key_, NULL ) ) 
+    void _LIBCPP_TLS_DESTRUCTOR_CC destruct_ (void *p) {
+        __free_with_fallback ( p );
+        if ( 0 != std::__libcpp_tls_set ( key_, NULL ) )
             abort_message("cannot zero out thread value for __cxa_get_globals()");
         }
 
     void construct_ () {
-        if ( 0 != pthread_key_create ( &key_, destruct_ ) )
-            abort_message("cannot create pthread key for __cxa_get_globals()");
+        if ( 0 != std::__libcpp_tls_create ( &key_, destruct_ ) )
+            abort_message("cannot create thread specific key for __cxa_get_globals()");
         }
 }   
 
@@ -77,11 +76,11 @@ extern "C" {
     //  If this is the first time we've been asked for these globals, create them
         if ( NULL == retVal ) {
             retVal = static_cast<__cxa_eh_globals*>
-                        (std::calloc (1, sizeof (__cxa_eh_globals)));
+                        (__calloc_with_fallback (1, sizeof (__cxa_eh_globals)));
             if ( NULL == retVal )
                 abort_message("cannot allocate __cxa_eh_globals");
-            if ( 0 != pthread_setspecific ( key_, retVal ) )
-               abort_message("pthread_setspecific failure in __cxa_get_globals()");
+            if ( 0 != std::__libcpp_tls_set ( key_, retVal ) )
+               abort_message("std::__libcpp_tls_set failure in __cxa_get_globals()");
            }
         return retVal;
         }
@@ -92,10 +91,10 @@ extern "C" {
     // libc++abi.
     __cxa_eh_globals * __cxa_get_globals_fast () {
     //  First time through, create the key.
-        if (0 != pthread_once(&flag_, construct_))
-            abort_message("pthread_once failure in __cxa_get_globals_fast()");
+        if (0 != std::__libcpp_execute_once(&flag_, construct_))
+            abort_message("execute once failure in __cxa_get_globals_fast()");
 //        static int init = construct_();
-        return static_cast<__cxa_eh_globals*>(::pthread_getspecific(key_));
+        return static_cast<__cxa_eh_globals*>(std::__libcpp_tls_get(key_));
         }
     
 }
diff --git a/lib/libcxxabi/src/cxa_guard.cpp b/lib/libcxxabi/src/cxa_guard.cpp
index 72e868f787e..f4c2a184dc5 100644
--- a/lib/libcxxabi/src/cxa_guard.cpp
+++ b/lib/libcxxabi/src/cxa_guard.cpp
@@ -10,11 +10,8 @@
 #include "__cxxabi_config.h"
 
 #include "abort_message.h"
-#include "config.h"
+#include <__threading_support>
 
-#if !LIBCXXABI_HAS_NO_THREADS
-#  include <pthread.h>
-#endif
 #include <stdint.h>
 
 /*
@@ -22,9 +19,9 @@
     which will turn around and try to call __cxa_guard_acquire reentrantly.
     For this reason, the headers of this file are as restricted as possible.
     Previous implementations of this code for __APPLE__ have used
-    pthread_mutex_lock and the abort_message utility without problem.  This
-    implementation also uses pthread_cond_wait which has tested to not be a
-    problem.
+    std::__libcpp_mutex_lock and the abort_message utility without problem. This
+    implementation also uses std::__libcpp_condvar_wait which has tested
+    to not be a problem.
 */
 
 namespace __cxxabiv1
@@ -34,39 +31,43 @@ namespace
 {
 
 #ifdef __arm__
-
 // A 32-bit, 4-byte-aligned static data value. The least significant 2 bits must
 // be statically initialized to 0.
 typedef uint32_t guard_type;
 
-// Test the lowest bit.
-inline bool is_initialized(guard_type* guard_object) {
-    return (*guard_object) & 1;
-}
-
 inline void set_initialized(guard_type* guard_object) {
     *guard_object |= 1;
 }
-
 #else
-
 typedef uint64_t guard_type;
 
-bool is_initialized(guard_type* guard_object) {
+void set_initialized(guard_type* guard_object) {
     char* initialized = (char*)guard_object;
-    return *initialized;
+    *initialized = 1;
 }
+#endif
 
-void set_initialized(guard_type* guard_object) {
+#if defined(_LIBCXXABI_HAS_NO_THREADS) || (defined(__APPLE__) && !defined(__arm__))
+#ifdef __arm__
+
+// Test the lowest bit.
+inline bool is_initialized(guard_type* guard_object) {
+    return (*guard_object) & 1;
+}
+
+#else
+
+bool is_initialized(guard_type* guard_object) {
     char* initialized = (char*)guard_object;
-    *initialized = 1;
+    return *initialized;
 }
 
 #endif
+#endif
 
-#if !LIBCXXABI_HAS_NO_THREADS
-pthread_mutex_t guard_mut = PTHREAD_MUTEX_INITIALIZER;
-pthread_cond_t  guard_cv  = PTHREAD_COND_INITIALIZER;
+#ifndef _LIBCXXABI_HAS_NO_THREADS
+std::__libcpp_mutex_t guard_mut = _LIBCPP_MUTEX_INITIALIZER;
+std::__libcpp_condvar_t guard_cv = _LIBCPP_CONDVAR_INITIALIZER;
 #endif
 
 #if defined(__APPLE__) && !defined(__arm__)
@@ -111,9 +112,10 @@ set_lock(uint64_t& x, lock_type y)
 
 typedef bool lock_type;
 
-inline
-lock_type
-get_lock(uint64_t x)
+#if !defined(__arm__)
+static_assert(std::is_same<guard_type, uint64_t>::value, "");
+
+inline lock_type get_lock(uint64_t x)
 {
     union
     {
@@ -123,9 +125,7 @@ get_lock(uint64_t x)
     return f.lock[1] != 0;
 }
 
-inline
-void
-set_lock(uint64_t& x, lock_type y)
+inline void set_lock(uint64_t& x, lock_type y)
 {
     union
     {
@@ -135,10 +135,10 @@ set_lock(uint64_t& x, lock_type y)
     f.lock[1] = y;
     x = f.guard;
 }
+#else // defined(__arm__)
+static_assert(std::is_same<guard_type, uint32_t>::value, "");
 
-inline
-lock_type
-get_lock(uint32_t x)
+inline lock_type get_lock(uint32_t x)
 {
     union
     {
@@ -148,9 +148,7 @@ get_lock(uint32_t x)
     return f.lock[1] != 0;
 }
 
-inline
-void
-set_lock(uint32_t& x, lock_type y)
+inline void set_lock(uint32_t& x, lock_type y)
 {
     union
     {
@@ -161,38 +159,37 @@ set_lock(uint32_t& x, lock_type y)
     x = f.guard;
 }
 
-#endif  // __APPLE__
+#endif // !defined(__arm__)
+
+#endif  // __APPLE__ && !__arm__
 
 }  // unnamed namespace
 
 extern "C"
 {
 
-#if LIBCXXABI_HAS_NO_THREADS
-_LIBCXXABI_FUNC_VIS int __cxa_guard_acquire(guard_type *guard_object) {
-    return !is_initialized(guard_object);
-}
-
-_LIBCXXABI_FUNC_VIS void __cxa_guard_release(guard_type *guard_object) {
-    *guard_object = 0;
-    set_initialized(guard_object);
-}
-
-_LIBCXXABI_FUNC_VIS void __cxa_guard_abort(guard_type *guard_object) {
-    *guard_object = 0;
-}
-
-#else // !LIBCXXABI_HAS_NO_THREADS
-
+#ifndef _LIBCXXABI_HAS_NO_THREADS
 _LIBCXXABI_FUNC_VIS int __cxa_guard_acquire(guard_type *guard_object) {
     char* initialized = (char*)guard_object;
-    if (pthread_mutex_lock(&guard_mut))
+    if (std::__libcpp_mutex_lock(&guard_mut))
         abort_message("__cxa_guard_acquire failed to acquire mutex");
     int result = *initialized == 0;
     if (result)
     {
 #if defined(__APPLE__) && !defined(__arm__)
-        const lock_type id = pthread_mach_thread_np(pthread_self());
+        // This is a special-case pthread dependency for Mac. We can't pull this
+        // out into libcxx's threading API (__threading_support) because not all
+        // supported Mac environments provide this function (in pthread.h). To
+        // make it possible to build/use libcxx in those environments, we have to
+        // keep this pthread dependency local to libcxxabi. If there is some
+        // convenient way to detect precisely when pthread_mach_thread_np is
+        // available in a given Mac environment, it might still be possible to
+        // bury this dependency in __threading_support.
+        #ifdef _LIBCPP_HAS_THREAD_API_PTHREAD
+           const lock_type id = pthread_mach_thread_np(std::__libcpp_thread_get_current_id());
+        #else
+           #error "How do I pthread_mach_thread_np()?"
+        #endif
         lock_type lock = get_lock(*guard_object);
         if (lock)
         {
@@ -201,7 +198,7 @@ _LIBCXXABI_FUNC_VIS int __cxa_guard_acquire(guard_type *guard_object) {
                 abort_message("__cxa_guard_acquire detected deadlock");
             do
             {
-                if (pthread_cond_wait(&guard_cv, &guard_mut))
+                if (std::__libcpp_condvar_wait(&guard_cv, &guard_mut))
                     abort_message("__cxa_guard_acquire condition variable wait failed");
                 lock = get_lock(*guard_object);
             } while (lock);
@@ -213,40 +210,55 @@ _LIBCXXABI_FUNC_VIS int __cxa_guard_acquire(guard_type *guard_object) {
             set_lock(*guard_object, id);
 #else  // !__APPLE__ || __arm__
         while (get_lock(*guard_object))
-            if (pthread_cond_wait(&guard_cv, &guard_mut))
+            if (std::__libcpp_condvar_wait(&guard_cv, &guard_mut))
                 abort_message("__cxa_guard_acquire condition variable wait failed");
         result = *initialized == 0;
         if (result)
             set_lock(*guard_object, true);
 #endif  // !__APPLE__ || __arm__
     }
-    if (pthread_mutex_unlock(&guard_mut))
+    if (std::__libcpp_mutex_unlock(&guard_mut))
         abort_message("__cxa_guard_acquire failed to release mutex");
     return result;
 }
 
 _LIBCXXABI_FUNC_VIS void __cxa_guard_release(guard_type *guard_object) {
-    if (pthread_mutex_lock(&guard_mut))
+    if (std::__libcpp_mutex_lock(&guard_mut))
         abort_message("__cxa_guard_release failed to acquire mutex");
     *guard_object = 0;
     set_initialized(guard_object);
-    if (pthread_mutex_unlock(&guard_mut))
+    if (std::__libcpp_mutex_unlock(&guard_mut))
         abort_message("__cxa_guard_release failed to release mutex");
-    if (pthread_cond_broadcast(&guard_cv))
+    if (std::__libcpp_condvar_broadcast(&guard_cv))
         abort_message("__cxa_guard_release failed to broadcast condition variable");
 }
 
 _LIBCXXABI_FUNC_VIS void __cxa_guard_abort(guard_type *guard_object) {
-    if (pthread_mutex_lock(&guard_mut))
+    if (std::__libcpp_mutex_lock(&guard_mut))
         abort_message("__cxa_guard_abort failed to acquire mutex");
     *guard_object = 0;
-    if (pthread_mutex_unlock(&guard_mut))
+    if (std::__libcpp_mutex_unlock(&guard_mut))
         abort_message("__cxa_guard_abort failed to release mutex");
-    if (pthread_cond_broadcast(&guard_cv))
+    if (std::__libcpp_condvar_broadcast(&guard_cv))
         abort_message("__cxa_guard_abort failed to broadcast condition variable");
 }
 
-#endif // !LIBCXXABI_HAS_NO_THREADS
+#else // _LIBCXXABI_HAS_NO_THREADS
+
+_LIBCXXABI_FUNC_VIS int __cxa_guard_acquire(guard_type *guard_object) {
+    return !is_initialized(guard_object);
+}
+
+_LIBCXXABI_FUNC_VIS void __cxa_guard_release(guard_type *guard_object) {
+    *guard_object = 0;
+    set_initialized(guard_object);
+}
+
+_LIBCXXABI_FUNC_VIS void __cxa_guard_abort(guard_type *guard_object) {
+    *guard_object = 0;
+}
+
+#endif // !_LIBCXXABI_HAS_NO_THREADS
 
 }  // extern "C"
 
diff --git a/lib/libcxxabi/src/cxa_handlers.cpp b/lib/libcxxabi/src/cxa_handlers.cpp
index 3f781313df8..2881a2a65fe 100644
--- a/lib/libcxxabi/src/cxa_handlers.cpp
+++ b/lib/libcxxabi/src/cxa_handlers.cpp
@@ -14,7 +14,6 @@
 #include <new>
 #include <exception>
 #include "abort_message.h"
-#include "config.h"
 #include "cxxabi.h"
 #include "cxa_handlers.hpp"
 #include "cxa_exception.hpp"
@@ -32,7 +31,6 @@ get_unexpected() _NOEXCEPT
 //  return __cxa_unexpected_handler.load(memory_order_acq);
 }
 
-__attribute__((visibility("hidden"), noreturn))
 void
 __unexpected(unexpected_handler func)
 {
@@ -57,7 +55,6 @@ get_terminate() _NOEXCEPT
 //  return __cxa_terminate_handler.load(memory_order_acq);
 }
 
-__attribute__((visibility("hidden"), noreturn))
 void
 __terminate(terminate_handler func) _NOEXCEPT
 {
@@ -104,7 +101,9 @@ terminate() _NOEXCEPT
 
 // In the future this will become:
 // std::atomic<std::new_handler>  __cxa_new_handler(0);
-extern "C" _LIBCXXABI_DATA_VIS new_handler __cxa_new_handler = 0;
+extern "C" {
+new_handler __cxa_new_handler = 0;
+}
 
 new_handler
 set_new_handler(new_handler handler) _NOEXCEPT
diff --git a/lib/libcxxabi/src/cxa_handlers.hpp b/lib/libcxxabi/src/cxa_handlers.hpp
index ce567ec1471..14c0e10119d 100644
--- a/lib/libcxxabi/src/cxa_handlers.hpp
+++ b/lib/libcxxabi/src/cxa_handlers.hpp
@@ -13,16 +13,18 @@
 #ifndef _CXA_HANDLERS_H
 #define _CXA_HANDLERS_H
 
+#include <__cxxabi_config.h>
+
 #include <exception>
 
 namespace std
 {
 
-__attribute__((visibility("hidden"), noreturn))
+_LIBCXXABI_HIDDEN _LIBCXXABI_NORETURN
 void
 __unexpected(unexpected_handler func);
 
-__attribute__((visibility("hidden"), noreturn))
+_LIBCXXABI_HIDDEN _LIBCXXABI_NORETURN
 void
 __terminate(terminate_handler func) _NOEXCEPT;
 
@@ -31,9 +33,9 @@ __terminate(terminate_handler func) _NOEXCEPT;
 extern "C"
 {
 
-extern void (*__cxa_terminate_handler)();
-extern void (*__cxa_unexpected_handler)();
-extern void (*__cxa_new_handler)();
+_LIBCXXABI_DATA_VIS extern void (*__cxa_terminate_handler)();
+_LIBCXXABI_DATA_VIS extern void (*__cxa_unexpected_handler)();
+_LIBCXXABI_DATA_VIS extern void (*__cxa_new_handler)();
 
 /*
 
diff --git a/lib/libcxxabi/src/cxa_noexception.cpp b/lib/libcxxabi/src/cxa_noexception.cpp
index e45ceff0165..adda552b89f 100644
--- a/lib/libcxxabi/src/cxa_noexception.cpp
+++ b/lib/libcxxabi/src/cxa_noexception.cpp
@@ -13,7 +13,6 @@
 
 // Support functions for the no-exceptions libc++ library
 
-#include "config.h"
 #include "cxxabi.h"
 
 #include <exception>        // for std::terminate
@@ -22,8 +21,6 @@
 
 namespace __cxxabiv1 {
 
-#pragma GCC visibility push(default)
-
 extern "C" {
 
 void
@@ -55,6 +52,4 @@ __cxa_uncaught_exceptions() throw() { return 0; }
 
 }  // extern "C"
 
-#pragma GCC visibility pop
-
 }  // abi
diff --git a/lib/libcxxabi/src/cxa_personality.cpp b/lib/libcxxabi/src/cxa_personality.cpp
index 85b6df2393a..7f857faf78f 100644
--- a/lib/libcxxabi/src/cxa_personality.cpp
+++ b/lib/libcxxabi/src/cxa_personality.cpp
@@ -18,7 +18,6 @@
 #include <typeinfo>
 
 #include "__cxxabi_config.h"
-#include "config.h"
 #include "cxa_exception.hpp"
 #include "cxa_handlers.hpp"
 #include "private_typeinfo.h"
@@ -317,7 +316,7 @@ call_terminate(bool native_exception, _Unwind_Exception* unwind_exception)
     std::terminate();
 }
 
-#if LIBCXXABI_ARM_EHABI
+#if defined(_LIBCXXABI_ARM_EHABI)
 static const void* read_target2_value(const void* ptr)
 {
     uintptr_t offset = *reinterpret_cast<const uintptr_t*>(ptr);
@@ -328,7 +327,7 @@ static const void* read_target2_value(const void* ptr)
     // deferred to the linker. For bare-metal they turn into absolute
     // relocations. For linux they turn into GOT-REL relocations."
     // https://gcc.gnu.org/ml/gcc-patches/2009-08/msg00264.html
-#if LIBCXXABI_BAREMETAL
+#if defined(LIBCXXABI_BAREMETAL)
     return reinterpret_cast<const void*>(reinterpret_cast<uintptr_t>(ptr) +
                                          offset);
 #else
@@ -348,14 +347,17 @@ get_shim_type_info(uint64_t ttypeIndex, const uint8_t* classInfo,
         call_terminate(native_exception, unwind_exception);
     }
 
-    assert(ttypeEncoding == DW_EH_PE_absptr && "Unexpected TTypeEncoding");
+    assert(((ttypeEncoding == DW_EH_PE_absptr) ||  // LLVM or GCC 4.6
+            (ttypeEncoding == DW_EH_PE_pcrel) ||  // GCC 4.7 baremetal
+            (ttypeEncoding == (DW_EH_PE_pcrel | DW_EH_PE_indirect))) &&  // GCC 4.7 linux
+           "Unexpected TTypeEncoding");
     (void)ttypeEncoding;
 
     const uint8_t* ttypePtr = classInfo - ttypeIndex * sizeof(uintptr_t);
     return reinterpret_cast<const __shim_type_info *>(
         read_target2_value(ttypePtr));
 }
-#else // !LIBCXXABI_ARM_EHABI
+#else // !defined(_LIBCXXABI_ARM_EHABI)
 static
 const __shim_type_info*
 get_shim_type_info(uint64_t ttypeIndex, const uint8_t* classInfo,
@@ -391,7 +393,7 @@ get_shim_type_info(uint64_t ttypeIndex, const uint8_t* classInfo,
     classInfo -= ttypeIndex;
     return (const __shim_type_info*)readEncodedPointer(&classInfo, ttypeEncoding);
 }
-#endif // !LIBCXXABI_ARM_EHABI
+#endif // !defined(_LIBCXXABI_ARM_EHABI)
 
 /*
     This is checking a thrown exception type, excpType, against a possibly empty
@@ -402,7 +404,7 @@ get_shim_type_info(uint64_t ttypeIndex, const uint8_t* classInfo,
     the list will catch a excpType.  If any catchType in the list can catch an
     excpType, then this exception spec does not catch the excpType.
 */
-#if LIBCXXABI_ARM_EHABI
+#if defined(_LIBCXXABI_ARM_EHABI)
 static
 bool
 exception_spec_can_catch(int64_t specIndex, const uint8_t* classInfo,
@@ -415,7 +417,10 @@ exception_spec_can_catch(int64_t specIndex, const uint8_t* classInfo,
         call_terminate(false, unwind_exception);
     }
 
-    assert(ttypeEncoding == DW_EH_PE_absptr && "Unexpected TTypeEncoding");
+    assert(((ttypeEncoding == DW_EH_PE_absptr) ||  // LLVM or GCC 4.6
+            (ttypeEncoding == DW_EH_PE_pcrel) ||  // GCC 4.7 baremetal
+            (ttypeEncoding == (DW_EH_PE_pcrel | DW_EH_PE_indirect))) &&  // GCC 4.7 linux
+           "Unexpected TTypeEncoding");
     (void)ttypeEncoding;
 
     // specIndex is negative of 1-based byte offset into classInfo;
@@ -928,7 +933,7 @@ _UA_CLEANUP_PHASE
         Else a cleanup is not found: return _URC_CONTINUE_UNWIND
 */
 
-#if !LIBCXXABI_ARM_EHABI
+#if !defined(_LIBCXXABI_ARM_EHABI)
 _LIBCXXABI_FUNC_VIS _Unwind_Reason_Code
 #ifdef __USING_SJLJ_EXCEPTIONS__
 __gxx_personality_sj0
@@ -1035,7 +1040,7 @@ static _Unwind_Reason_Code continue_unwind(_Unwind_Exception* unwind_exception,
 }
 
 // ARM register names
-#if !LIBCXXABI_USE_LLVM_UNWINDER
+#if !defined(LIBCXXABI_USE_LLVM_UNWINDER)
 static const uint32_t REG_UCB = 12;  // Register to save _Unwind_Control_Block
 #endif
 static const uint32_t REG_SP = 13;
@@ -1071,7 +1076,7 @@ __gxx_personality_v0(_Unwind_State state,
     bool native_exception = (unwind_exception->exception_class & get_vendor_and_language) ==
                             (kOurExceptionClass & get_vendor_and_language);
 
-#if !LIBCXXABI_USE_LLVM_UNWINDER
+#if !defined(LIBCXXABI_USE_LLVM_UNWINDER)
     // Copy the address of _Unwind_Control_Block to r12 so that
     // _Unwind_GetLanguageSpecificData() and _Unwind_GetRegionStart() can
     // return correct address.
@@ -1188,7 +1193,7 @@ __cxa_call_unexpected(void* arg)
         u_handler = old_exception_header->unexpectedHandler;
         // If std::__unexpected(u_handler) rethrows the same exception,
         //   these values get overwritten by the rethrow.  So save them now:
-#if LIBCXXABI_ARM_EHABI
+#if defined(_LIBCXXABI_ARM_EHABI)
         ttypeIndex = (int64_t)(int32_t)unwind_exception->barrier_cache.bitpattern[4];
         lsda = (const uint8_t*)unwind_exception->barrier_cache.bitpattern[2];
 #else
diff --git a/lib/libcxxabi/src/cxa_thread_atexit.cpp b/lib/libcxxabi/src/cxa_thread_atexit.cpp
index 7962e28af70..49d15d6b145 100644
--- a/lib/libcxxabi/src/cxa_thread_atexit.cpp
+++ b/lib/libcxxabi/src/cxa_thread_atexit.cpp
@@ -7,20 +7,134 @@
 //
 //===----------------------------------------------------------------------===//
 
+#include "abort_message.h"
 #include "cxxabi.h"
+#include <__threading_support>
+#include <cstdlib>
 
 namespace __cxxabiv1 {
+
+  using Dtor = void(*)(void*);
+
+  extern "C"
+#ifndef HAVE___CXA_THREAD_ATEXIT_IMPL
+  // A weak symbol is used to detect this function's presence in the C library
+  // at runtime, even if libc++ is built against an older libc
+  _LIBCXXABI_WEAK
+#endif
+  int __cxa_thread_atexit_impl(Dtor, void*, void*);
+
+#ifndef HAVE___CXA_THREAD_ATEXIT_IMPL
+
+namespace {
+  // This implementation is used if the C library does not provide
+  // __cxa_thread_atexit_impl() for us.  It has a number of limitations that are
+  // difficult to impossible to address without ..._impl():
+  //
+  // - dso_symbol is ignored.  This means that a shared library may be unloaded
+  //   (via dlclose()) before its thread_local destructors have run.
+  //
+  // - thread_local destructors for the main thread are run by the destructor of
+  //   a static object.  This is later than expected; they should run before the
+  //   destructors of any objects with static storage duration.
+  //
+  // - thread_local destructors on non-main threads run on the first iteration
+  //   through the __libccpp_tls_key destructors.
+  //   std::notify_all_at_thread_exit() and similar functions must be careful to
+  //   wait until the second iteration to provide their intended ordering
+  //   guarantees.
+  //
+  // Another limitation, though one shared with ..._impl(), is that any
+  // thread_locals that are first initialized after non-thread_local global
+  // destructors begin to run will not be destroyed.  [basic.start.term] states
+  // that all thread_local destructors are sequenced before the destruction of
+  // objects with static storage duration, resulting in a contradiction if a
+  // thread_local is constructed after that point.  Thus we consider such
+  // programs ill-formed, and don't bother to run those destructors.  (If the
+  // program terminates abnormally after such a thread_local is constructed,
+  // the destructor is not expected to run and thus there is no contradiction.
+  // So construction still has to work.)
+
+  struct DtorList {
+    Dtor dtor;
+    void* obj;
+    DtorList* next;
+  };
+
+  // The linked list of thread-local destructors to run
+  __thread DtorList* dtors = nullptr;
+  // True if the destructors are currently scheduled to run on this thread
+  __thread bool dtors_alive = false;
+  // Used to trigger destructors on thread exit; value is ignored
+  std::__libcpp_tls_key dtors_key;
+
+  void run_dtors(void*) {
+    while (auto head = dtors) {
+      dtors = head->next;
+      head->dtor(head->obj);
+      std::free(head);
+    }
+
+    dtors_alive = false;
+  }
+
+  struct DtorsManager {
+    DtorsManager() {
+      // There is intentionally no matching std::__libcpp_tls_delete call, as
+      // __cxa_thread_atexit() may be called arbitrarily late (for example, from
+      // global destructors or atexit() handlers).
+      if (std::__libcpp_tls_create(&dtors_key, run_dtors) != 0) {
+        abort_message("std::__libcpp_tls_create() failed in __cxa_thread_atexit()");
+      }
+    }
+
+    ~DtorsManager() {
+      // std::__libcpp_tls_key destructors do not run on threads that call exit()
+      // (including when the main thread returns from main()), so we explicitly
+      // call the destructor here.  This runs at exit time (potentially earlier
+      // if libc++abi is dlclose()'d).  Any thread_locals initialized after this
+      // point will not be destroyed.
+      run_dtors(nullptr);
+    }
+  };
+} // namespace
+
+#endif // HAVE___CXA_THREAD_ATEXIT_IMPL
+
 extern "C" {
 
+  _LIBCXXABI_FUNC_VIS int __cxa_thread_atexit(Dtor dtor, void* obj, void* dso_symbol) throw() {
 #ifdef HAVE___CXA_THREAD_ATEXIT_IMPL
+    return __cxa_thread_atexit_impl(dtor, obj, dso_symbol);
+#else
+    if (__cxa_thread_atexit_impl) {
+      return __cxa_thread_atexit_impl(dtor, obj, dso_symbol);
+    } else {
+      // Initialize the dtors std::__libcpp_tls_key (uses __cxa_guard_*() for
+      // one-time initialization and __cxa_atexit() for destruction)
+      static DtorsManager manager;
+
+      if (!dtors_alive) {
+        if (std::__libcpp_tls_set(dtors_key, &dtors_key) != 0) {
+          return -1;
+        }
+        dtors_alive = true;
+      }
+
+      auto head = static_cast<DtorList*>(std::malloc(sizeof(DtorList)));
+      if (!head) {
+        return -1;
+      }
 
-_LIBCXXABI_FUNC_VIS int __cxa_thread_atexit(void (*dtor)(void *), void *obj,
-                                            void *dso_symbol) throw() {
-  extern int __cxa_thread_atexit_impl(void (*)(void *), void *, void *);
-  return __cxa_thread_atexit_impl(dtor, obj, dso_symbol);
-}
+      head->dtor = dtor;
+      head->obj = obj;
+      head->next = dtors;
+      dtors = head;
 
-#endif // HAVE__CXA_THREAD_ATEXIT_IMPL
+      return 0;
+    }
+#endif // HAVE___CXA_THREAD_ATEXIT_IMPL
+  }
 
 } // extern "C"
 } // namespace __cxxabiv1
diff --git a/lib/libcxxabi/src/cxa_unexpected.cpp b/lib/libcxxabi/src/cxa_unexpected.cpp
index f6e6b6ab97e..7d4ef80c39e 100644
--- a/lib/libcxxabi/src/cxa_unexpected.cpp
+++ b/lib/libcxxabi/src/cxa_unexpected.cpp
@@ -8,20 +8,16 @@
 //===----------------------------------------------------------------------===//
 
 #include <exception>
-#include <cxxabi.h>
+#include "cxxabi.h"
 #include "cxa_exception.hpp"
 
 namespace __cxxabiv1
 {
 
-#pragma GCC visibility push(default)
-
 extern "C"
 {
 
 }
 
-#pragma GCC visibility pop
-
 }  // namespace __cxxabiv1
 
diff --git a/lib/libcxxabi/src/cxa_virtual.cpp b/lib/libcxxabi/src/cxa_virtual.cpp
index ac81ad39d07..f59fa7ee2c6 100644
--- a/lib/libcxxabi/src/cxa_virtual.cpp
+++ b/lib/libcxxabi/src/cxa_virtual.cpp
@@ -12,12 +12,12 @@
 
 namespace __cxxabiv1 {
 extern "C" {
-_LIBCXXABI_FUNC_VIS LIBCXXABI_NORETURN
+_LIBCXXABI_FUNC_VIS _LIBCXXABI_NORETURN
 void __cxa_pure_virtual(void) {
   abort_message("Pure virtual function called!");
 }
 
-_LIBCXXABI_FUNC_VIS LIBCXXABI_NORETURN
+_LIBCXXABI_FUNC_VIS _LIBCXXABI_NORETURN
 void __cxa_deleted_virtual(void) {
   abort_message("Deleted virtual function called!");
 }
diff --git a/lib/libcxxabi/src/fallback_malloc.cpp b/lib/libcxxabi/src/fallback_malloc.cpp
new file mode 100644
index 00000000000..336ad31b017
--- /dev/null
+++ b/lib/libcxxabi/src/fallback_malloc.cpp
@@ -0,0 +1,252 @@
+//===------------------------ fallback_malloc.cpp -------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is dual licensed under the MIT and the University of Illinois Open
+// Source Licenses. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+#include "fallback_malloc.h"
+
+#include <__threading_support>
+
+#include <cstdlib> // for malloc, calloc, free
+#include <cstring> // for memset
+
+//  A small, simple heap manager based (loosely) on
+//  the startup heap manager from FreeBSD, optimized for space.
+//
+//  Manages a fixed-size memory pool, supports malloc and free only.
+//  No support for realloc.
+//
+//  Allocates chunks in multiples of four bytes, with a four byte header
+//  for each chunk. The overhead of each chunk is kept low by keeping pointers
+//  as two byte offsets within the heap, rather than (4 or 8 byte) pointers.
+
+namespace {
+
+// When POSIX threads are not available, make the mutex operations a nop
+#ifndef _LIBCXXABI_HAS_NO_THREADS
+_LIBCPP_SAFE_STATIC
+static std::__libcpp_mutex_t heap_mutex = _LIBCPP_MUTEX_INITIALIZER;
+#else
+static void* heap_mutex = 0;
+#endif
+
+class mutexor {
+public:
+#ifndef _LIBCXXABI_HAS_NO_THREADS
+  mutexor(std::__libcpp_mutex_t* m) : mtx_(m) {
+    std::__libcpp_mutex_lock(mtx_);
+  }
+  ~mutexor() { std::__libcpp_mutex_unlock(mtx_); }
+#else
+  mutexor(void*) {}
+  ~mutexor() {}
+#endif
+private:
+  mutexor(const mutexor& rhs);
+  mutexor& operator=(const mutexor& rhs);
+#ifndef _LIBCXXABI_HAS_NO_THREADS
+  std::__libcpp_mutex_t* mtx_;
+#endif
+};
+
+static const size_t HEAP_SIZE = 512;
+char heap[HEAP_SIZE] __attribute__((aligned));
+
+typedef unsigned short heap_offset;
+typedef unsigned short heap_size;
+
+struct heap_node {
+  heap_offset next_node; // offset into heap
+  heap_size len;         // size in units of "sizeof(heap_node)"
+};
+
+static const heap_node* list_end =
+    (heap_node*)(&heap[HEAP_SIZE]); // one past the end of the heap
+static heap_node* freelist = NULL;
+
+heap_node* node_from_offset(const heap_offset offset) {
+  return (heap_node*)(heap + (offset * sizeof(heap_node)));
+}
+
+heap_offset offset_from_node(const heap_node* ptr) {
+  return static_cast<heap_offset>(
+      static_cast<size_t>(reinterpret_cast<const char*>(ptr) - heap) /
+      sizeof(heap_node));
+}
+
+void init_heap() {
+  freelist = (heap_node*)heap;
+  freelist->next_node = offset_from_node(list_end);
+  freelist->len = HEAP_SIZE / sizeof(heap_node);
+}
+
+//  How big a chunk we allocate
+size_t alloc_size(size_t len) {
+  return (len + sizeof(heap_node) - 1) / sizeof(heap_node) + 1;
+}
+
+bool is_fallback_ptr(void* ptr) {
+  return ptr >= heap && ptr < (heap + HEAP_SIZE);
+}
+
+void* fallback_malloc(size_t len) {
+  heap_node *p, *prev;
+  const size_t nelems = alloc_size(len);
+  mutexor mtx(&heap_mutex);
+
+  if (NULL == freelist)
+    init_heap();
+
+  //  Walk the free list, looking for a "big enough" chunk
+  for (p = freelist, prev = 0; p && p != list_end;
+       prev = p, p = node_from_offset(p->next_node)) {
+
+    if (p->len > nelems) { //  chunk is larger, shorten, and return the tail
+      heap_node* q;
+
+      p->len = static_cast<heap_size>(p->len - nelems);
+      q = p + p->len;
+      q->next_node = 0;
+      q->len = static_cast<heap_size>(nelems);
+      return (void*)(q + 1);
+    }
+
+    if (p->len == nelems) { // exact size match
+      if (prev == 0)
+        freelist = node_from_offset(p->next_node);
+      else
+        prev->next_node = p->next_node;
+      p->next_node = 0;
+      return (void*)(p + 1);
+    }
+  }
+  return NULL; // couldn't find a spot big enough
+}
+
+//  Return the start of the next block
+heap_node* after(struct heap_node* p) { return p + p->len; }
+
+void fallback_free(void* ptr) {
+  struct heap_node* cp = ((struct heap_node*)ptr) - 1; // retrieve the chunk
+  struct heap_node *p, *prev;
+
+  mutexor mtx(&heap_mutex);
+
+#ifdef DEBUG_FALLBACK_MALLOC
+  std::cout << "Freeing item at " << offset_from_node(cp) << " of size "
+            << cp->len << std::endl;
+#endif
+
+  for (p = freelist, prev = 0; p && p != list_end;
+       prev = p, p = node_from_offset(p->next_node)) {
+#ifdef DEBUG_FALLBACK_MALLOC
+    std::cout << "  p, cp, after (p), after(cp) " << offset_from_node(p) << ' '
+              << offset_from_node(cp) << ' ' << offset_from_node(after(p))
+              << ' ' << offset_from_node(after(cp)) << std::endl;
+#endif
+    if (after(p) == cp) {
+#ifdef DEBUG_FALLBACK_MALLOC
+      std::cout << "  Appending onto chunk at " << offset_from_node(p)
+                << std::endl;
+#endif
+      p->len = static_cast<heap_size>(
+          p->len + cp->len); // make the free heap_node larger
+      return;
+    } else if (after(cp) == p) { // there's a free heap_node right after
+#ifdef DEBUG_FALLBACK_MALLOC
+      std::cout << "  Appending free chunk at " << offset_from_node(p)
+                << std::endl;
+#endif
+      cp->len = static_cast<heap_size>(cp->len + p->len);
+      if (prev == 0) {
+        freelist = cp;
+        cp->next_node = p->next_node;
+      } else
+        prev->next_node = offset_from_node(cp);
+      return;
+    }
+  }
+//  Nothing to merge with, add it to the start of the free list
+#ifdef DEBUG_FALLBACK_MALLOC
+  std::cout << "  Making new free list entry " << offset_from_node(cp)
+            << std::endl;
+#endif
+  cp->next_node = offset_from_node(freelist);
+  freelist = cp;
+}
+
+#ifdef INSTRUMENT_FALLBACK_MALLOC
+size_t print_free_list() {
+  struct heap_node *p, *prev;
+  heap_size total_free = 0;
+  if (NULL == freelist)
+    init_heap();
+
+  for (p = freelist, prev = 0; p && p != list_end;
+       prev = p, p = node_from_offset(p->next_node)) {
+    std::cout << (prev == 0 ? "" : "  ") << "Offset: " << offset_from_node(p)
+              << "\tsize: " << p->len << " Next: " << p->next_node << std::endl;
+    total_free += p->len;
+  }
+  std::cout << "Total Free space: " << total_free << std::endl;
+  return total_free;
+}
+#endif
+} // end unnamed namespace
+
+namespace __cxxabiv1 {
+
+struct __attribute__((aligned)) __aligned_type {};
+
+void* __aligned_malloc_with_fallback(size_t size) {
+#if defined(_WIN32)
+  if (void* dest = _aligned_malloc(size, alignof(__aligned_type)))
+    return dest;
+#elif defined(_LIBCPP_HAS_NO_ALIGNED_ALLOCATION)
+  if (void* dest = std::malloc(size))
+    return dest;
+#else
+  if (size == 0)
+    size = 1;
+  void* dest;
+  if (::posix_memalign(&dest, alignof(__aligned_type), size) == 0)
+    return dest;
+#endif
+  return fallback_malloc(size);
+}
+
+void* __calloc_with_fallback(size_t count, size_t size) {
+  void* ptr = std::calloc(count, size);
+  if (NULL != ptr)
+    return ptr;
+  // if calloc fails, fall back to emergency stash
+  ptr = fallback_malloc(size * count);
+  if (NULL != ptr)
+    std::memset(ptr, 0, size * count);
+  return ptr;
+}
+
+void __aligned_free_with_fallback(void* ptr) {
+  if (is_fallback_ptr(ptr))
+    fallback_free(ptr);
+  else {
+#if defined(_WIN32)
+    ::_aligned_free(ptr);
+#else
+    std::free(ptr);
+#endif
+  }
+}
+
+void __free_with_fallback(void* ptr) {
+  if (is_fallback_ptr(ptr))
+    fallback_free(ptr);
+  else
+    std::free(ptr);
+}
+
+} // namespace __cxxabiv1
diff --git a/lib/libcxxabi/src/fallback_malloc.h b/lib/libcxxabi/src/fallback_malloc.h
new file mode 100644
index 00000000000..d6f471483a2
--- /dev/null
+++ b/lib/libcxxabi/src/fallback_malloc.h
@@ -0,0 +1,29 @@
+//===------------------------- fallback_malloc.h --------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is dual licensed under the MIT and the University of Illinois Open
+// Source Licenses. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef _FALLBACK_MALLOC_H
+#define _FALLBACK_MALLOC_H
+
+#include "__cxxabi_config.h"
+#include <cstddef> // for size_t
+
+namespace __cxxabiv1 {
+
+// Allocate some memory from _somewhere_
+_LIBCXXABI_HIDDEN void * __aligned_malloc_with_fallback(size_t size);
+
+// Allocate and zero-initialize memory from _somewhere_
+_LIBCXXABI_HIDDEN void * __calloc_with_fallback(size_t count, size_t size);
+
+_LIBCXXABI_HIDDEN void __aligned_free_with_fallback(void *ptr);
+_LIBCXXABI_HIDDEN void __free_with_fallback(void *ptr);
+
+} // namespace __cxxabiv1
+
+#endif
diff --git a/lib/libcxxabi/src/include/refstring.h b/lib/libcxxabi/src/include/refstring.h
new file mode 100644
index 00000000000..bc131aeb5ae
--- /dev/null
+++ b/lib/libcxxabi/src/include/refstring.h
@@ -0,0 +1,131 @@
+//===------------------------ __refstring ---------------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is dual licensed under the MIT and the University of Illinois Open
+// Source Licenses. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+// FIXME: This file is copied from libcxx/src/include/refstring.h. Instead of
+// duplicating the file in libc++abi we should require that the libc++ sources
+// are available when building libc++abi.
+
+#ifndef _LIBCPPABI_REFSTRING_H
+#define _LIBCPPABI_REFSTRING_H
+
+#include <__config>
+#include <stdexcept>
+#include <cstddef>
+#include <cstring>
+#ifdef __APPLE__
+#include <dlfcn.h>
+#include <mach-o/dyld.h>
+#endif
+
+_LIBCPP_BEGIN_NAMESPACE_STD
+
+namespace __refstring_imp { namespace {
+typedef int count_t;
+
+struct _Rep_base {
+    std::size_t len;
+    std::size_t cap;
+    count_t     count;
+};
+
+inline _Rep_base* rep_from_data(const char *data_) noexcept {
+    char *data = const_cast<char *>(data_);
+    return reinterpret_cast<_Rep_base *>(data - sizeof(_Rep_base));
+}
+
+inline char * data_from_rep(_Rep_base *rep) noexcept {
+    char *data = reinterpret_cast<char *>(rep);
+    return data + sizeof(*rep);
+}
+
+#if defined(__APPLE__)
+inline
+const char* compute_gcc_empty_string_storage() _NOEXCEPT
+{
+    void* handle = dlopen("/usr/lib/libstdc++.6.dylib", RTLD_NOLOAD);
+    if (handle == nullptr)
+        return nullptr;
+    void* sym = dlsym(handle, "_ZNSs4_Rep20_S_empty_rep_storageE");
+    if (sym == nullptr)
+        return nullptr;
+    return data_from_rep(reinterpret_cast<_Rep_base *>(sym));
+}
+
+inline
+const char*
+get_gcc_empty_string_storage() _NOEXCEPT
+{
+    static const char* p = compute_gcc_empty_string_storage();
+    return p;
+}
+#endif
+
+}} // namespace __refstring_imp
+
+using namespace __refstring_imp;
+
+inline
+__libcpp_refstring::__libcpp_refstring(const char* msg) {
+    std::size_t len = strlen(msg);
+    _Rep_base* rep = static_cast<_Rep_base *>(::operator new(sizeof(*rep) + len + 1));
+    rep->len = len;
+    rep->cap = len;
+    rep->count = 0;
+    char *data = data_from_rep(rep);
+    std::memcpy(data, msg, len + 1);
+    __imp_ = data;
+}
+
+inline
+__libcpp_refstring::__libcpp_refstring(const __libcpp_refstring &s) _NOEXCEPT
+    : __imp_(s.__imp_)
+{
+    if (__uses_refcount())
+        __sync_add_and_fetch(&rep_from_data(__imp_)->count, 1);
+}
+
+inline
+__libcpp_refstring& __libcpp_refstring::operator=(__libcpp_refstring const& s) _NOEXCEPT {
+    bool adjust_old_count = __uses_refcount();
+    struct _Rep_base *old_rep = rep_from_data(__imp_);
+    __imp_ = s.__imp_;
+    if (__uses_refcount())
+        __sync_add_and_fetch(&rep_from_data(__imp_)->count, 1);
+    if (adjust_old_count)
+    {
+        if (__sync_add_and_fetch(&old_rep->count, count_t(-1)) < 0)
+        {
+            ::operator delete(old_rep);
+        }
+    }
+    return *this;
+}
+
+inline
+__libcpp_refstring::~__libcpp_refstring() {
+    if (__uses_refcount()) {
+        _Rep_base* rep = rep_from_data(__imp_);
+        if (__sync_add_and_fetch(&rep->count, count_t(-1)) < 0) {
+            ::operator delete(rep);
+        }
+    }
+}
+
+inline
+bool __libcpp_refstring::__uses_refcount() const {
+#ifdef __APPLE__
+    return __imp_ != get_gcc_empty_string_storage();
+#else
+    return true;
+#endif
+}
+
+_LIBCPP_END_NAMESPACE_STD
+
+#endif //_LIBCPPABI_REFSTRING_H
diff --git a/lib/libcxxabi/src/private_typeinfo.cpp b/lib/libcxxabi/src/private_typeinfo.cpp
index df03596e8b6..ef9466ef610 100644
--- a/lib/libcxxabi/src/private_typeinfo.cpp
+++ b/lib/libcxxabi/src/private_typeinfo.cpp
@@ -55,12 +55,7 @@
 #include <string.h>
 #endif
 
-namespace __cxxabiv1
-{
-
-#pragma GCC visibility push(hidden)
-
-inline
+static inline
 bool
 is_equal(const std::type_info* x, const std::type_info* y, bool use_strcmp)
 {
@@ -73,6 +68,8 @@ is_equal(const std::type_info* x, const std::type_info* y, bool use_strcmp)
 #endif
 }
 
+namespace __cxxabiv1
+{
 
 // __shim_type_info
 
@@ -171,8 +168,12 @@ __pointer_to_member_type_info::~__pointer_to_member_type_info()
 // catch (D2& d2) : adjustedPtr == &d2  (d2 is base class of thrown object)
 // catch (D2* d2) : adjustedPtr == d2
 // catch (D2*& d2) : adjustedPtr == d2
-// 
+//
 // catch (...) : adjustedPtr == & of the exception
+//
+// If the thrown type is nullptr_t and the caught type is a pointer to
+// member type, adjustedPtr points to a statically-allocated null pointer
+// representation of that type.
 
 // Handles bullet 1
 bool
@@ -228,7 +229,7 @@ __class_type_info::can_catch(const __shim_type_info* thrown_type,
     if (thrown_class_type == 0)
         return false;
     // bullet 2
-    __dynamic_cast_info info = {thrown_class_type, 0, this, -1, 0};
+    __dynamic_cast_info info = {thrown_class_type, 0, this, -1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,};
     info.number_of_dst_type = 1;
     thrown_class_type->has_unambiguous_public_base(&info, adjustedPtr, public_path);
     if (info.path_dst_ptr_to_static_ptr == public_path)
@@ -337,12 +338,11 @@ __vmi_class_type_info::has_unambiguous_public_base(__dynamic_cast_info* info,
     }
 }
 
-// Handles bullets 1 and 4 for both pointers and member pointers
+// Handles bullet 1 for both pointers and member pointers
 bool
 __pbase_type_info::can_catch(const __shim_type_info* thrown_type,
                              void*&) const
 {
-    if (is_equal(thrown_type, &typeid(std::nullptr_t), false)) return true;
     bool use_strcmp = this->__flags & (__incomplete_class_mask |
                                        __incomplete_mask);
     if (!use_strcmp) {
@@ -367,7 +367,13 @@ bool
 __pointer_type_info::can_catch(const __shim_type_info* thrown_type,
                                void*& adjustedPtr) const
 {
-    // bullets 1 and 4
+    // bullet 4
+    if (is_equal(thrown_type, &typeid(std::nullptr_t), false)) {
+      adjustedPtr = nullptr;
+      return true;
+    }
+
+    // bullet 1
     if (__pbase_type_info::can_catch(thrown_type, adjustedPtr)) {
         if (adjustedPtr != NULL)
             adjustedPtr = *static_cast<void**>(adjustedPtr);
@@ -381,8 +387,10 @@ __pointer_type_info::can_catch(const __shim_type_info* thrown_type,
     // Do the dereference adjustment
     if (adjustedPtr != NULL)
         adjustedPtr = *static_cast<void**>(adjustedPtr);
-    // bullet 3B
-    if (thrown_pointer_type->__flags & ~__flags)
+    // bullet 3B and 3C
+    if (thrown_pointer_type->__flags & ~__flags & __no_remove_flags_mask)
+        return false;
+    if (__flags & ~thrown_pointer_type->__flags & __no_add_flags_mask)
         return false;
     if (is_equal(__pointee, thrown_pointer_type->__pointee, false))
         return true;
@@ -419,7 +427,7 @@ __pointer_type_info::can_catch(const __shim_type_info* thrown_type,
         dynamic_cast<const __class_type_info*>(thrown_pointer_type->__pointee);
     if (thrown_class_type == 0)
         return false;
-    __dynamic_cast_info info = {thrown_class_type, 0, catch_class_type, -1, 0};
+    __dynamic_cast_info info = {thrown_class_type, 0, catch_class_type, -1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,};
     info.number_of_dst_type = 1;
     thrown_class_type->has_unambiguous_public_base(&info, adjustedPtr, public_path);
     if (info.path_dst_ptr_to_static_ptr == public_path)
@@ -468,7 +476,22 @@ bool __pointer_type_info::can_catch_nested(
 
 bool __pointer_to_member_type_info::can_catch(
     const __shim_type_info* thrown_type, void*& adjustedPtr) const {
-    // bullets 1 and 4
+    // bullet 4
+    if (is_equal(thrown_type, &typeid(std::nullptr_t), false)) {
+      // We assume that the pointer to member representation is the same for
+      // all pointers to data members and for all pointers to member functions.
+      struct X {};
+      if (dynamic_cast<const __function_type_info*>(__pointee)) {
+        static int (X::*const null_ptr_rep)() = nullptr;
+        adjustedPtr = const_cast<int (X::**)()>(&null_ptr_rep);
+      } else {
+        static int X::*const null_ptr_rep = nullptr;
+        adjustedPtr = const_cast<int X::**>(&null_ptr_rep);
+      }
+      return true;
+    }
+
+    // bullet 1
     if (__pbase_type_info::can_catch(thrown_type, adjustedPtr))
         return true;
 
@@ -476,7 +499,9 @@ bool __pointer_to_member_type_info::can_catch(
         dynamic_cast<const __pointer_to_member_type_info*>(thrown_type);
     if (thrown_pointer_type == 0)
         return false;
-    if (thrown_pointer_type->__flags & ~__flags)
+    if (thrown_pointer_type->__flags & ~__flags & __no_remove_flags_mask)
+        return false;
+    if (__flags & ~thrown_pointer_type->__flags & __no_add_flags_mask)
         return false;
     if (!is_equal(__pointee, thrown_pointer_type->__pointee, false))
         return false;
@@ -510,9 +535,6 @@ bool __pointer_to_member_type_info::can_catch_nested(
 #pragma clang diagnostic pop
 #endif
 
-#pragma GCC visibility pop
-#pragma GCC visibility push(default)
-
 #ifdef __clang__
 #pragma clang diagnostic push
 #pragma clang diagnostic ignored "-Wmissing-field-initializers"
@@ -592,13 +614,11 @@ bool __pointer_to_member_type_info::can_catch_nested(
 // If there is a public path from (dynamic_ptr, dynamic_type) to
 //    (static_ptr, static_type), then return dynamic_ptr.
 // Else return nullptr.
-extern "C"
-void*
-__dynamic_cast(const void* static_ptr,
-               const __class_type_info* static_type,
-               const __class_type_info* dst_type,
-               std::ptrdiff_t src2dst_offset)
-{
+
+extern "C" _LIBCXXABI_FUNC_VIS void *
+__dynamic_cast(const void *static_ptr, const __class_type_info *static_type,
+               const __class_type_info *dst_type,
+               std::ptrdiff_t src2dst_offset) {
     // Possible future optimization:  Take advantage of src2dst_offset
     // Currently clang always sets src2dst_offset to -1 (no hint).
 
@@ -613,7 +633,7 @@ __dynamic_cast(const void* static_ptr,
     //    be returned.
     const void* dst_ptr = 0;
     // Initialize info struct for this search.
-    __dynamic_cast_info info = {dst_type, static_ptr, static_type, src2dst_offset, 0};
+    __dynamic_cast_info info = {dst_type, static_ptr, static_type, src2dst_offset, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,};
 
     // Find out if we can use a giant short cut in the search
     if (is_equal(dynamic_type, dst_type, false))
@@ -653,8 +673,8 @@ __dynamic_cast(const void* static_ptr,
             info.path_dynamic_ptr_to_static_ptr == unknown)
         {
             syslog(LOG_ERR, "dynamic_cast error 2: One or more of the following type_info's "
-                            " has hidden visibility.  They should all have public visibility.  "
-                            " %s, %s, %s.\n", static_type->name(), dynamic_type->name(),
+                            "has hidden visibility.  They should all have public visibility.  "
+                            "%s, %s, %s.\n", static_type->name(), dynamic_type->name(),
                     dst_type->name());
             // Redo the search comparing type_info's using strcmp
             info = {dst_type, static_ptr, static_type, src2dst_offset, 0};
@@ -689,9 +709,6 @@ __dynamic_cast(const void* static_ptr,
 #pragma clang diagnostic pop
 #endif
 
-#pragma GCC visibility pop
-#pragma GCC visibility push(hidden)
-
 // Call this function when you hit a static_type which is a base (above) a dst_type.
 // Let caller know you hit a static_type.  But only start recording details if
 // this is (static_ptr, static_type) -- the node we are casting from.
@@ -1274,6 +1291,4 @@ __base_class_type_info::search_below_dst(__dynamic_cast_info* info,
                                   use_strcmp);
 }
 
-#pragma GCC visibility pop
-
 }  // __cxxabiv1
diff --git a/lib/libcxxabi/src/private_typeinfo.h b/lib/libcxxabi/src/private_typeinfo.h
index ef98c3ae60b..3922ae6ef56 100644
--- a/lib/libcxxabi/src/private_typeinfo.h
+++ b/lib/libcxxabi/src/private_typeinfo.h
@@ -16,7 +16,6 @@
 #include <cstddef>
 
 namespace __cxxabiv1 {
-#pragma GCC visibility push(hidden)
 
 class _LIBCXXABI_TYPE_VIS __shim_type_info : public std::type_info {
 public:
@@ -67,7 +66,7 @@ enum
 
 class _LIBCXXABI_TYPE_VIS __class_type_info;
 
-struct __dynamic_cast_info
+struct _LIBCXXABI_HIDDEN __dynamic_cast_info
 {
 // const data supplied to the search:
 
@@ -153,7 +152,7 @@ public:
   has_unambiguous_public_base(__dynamic_cast_info *, void *, int) const;
 };
 
-struct __base_class_type_info
+struct _LIBCXXABI_HIDDEN __base_class_type_info
 {
 public:
     const __class_type_info* __base_type;
@@ -206,7 +205,22 @@ public:
     __volatile_mask = 0x2,
     __restrict_mask = 0x4,
     __incomplete_mask = 0x8,
-    __incomplete_class_mask = 0x10
+    __incomplete_class_mask = 0x10,
+    __transaction_safe_mask = 0x20,
+    // This implements the following proposal from cxx-abi-dev (not yet part of
+    // the ABI document):
+    //
+    //   http://sourcerytools.com/pipermail/cxx-abi-dev/2016-October/002986.html
+    //
+    // This is necessary for support of http://wg21.link/p0012, which permits
+    // throwing noexcept function and member function pointers and catching
+    // them as non-noexcept pointers.
+    __noexcept_mask = 0x40,
+
+    // Flags that cannot be removed by a standard conversion.
+    __no_remove_flags_mask = __const_mask | __volatile_mask | __restrict_mask,
+    // Flags that cannot be added by a standard conversion.
+    __no_add_flags_mask = __transaction_safe_mask | __noexcept_mask
   };
 
   _LIBCXXABI_HIDDEN virtual ~__pbase_type_info();
@@ -233,8 +247,6 @@ public:
   _LIBCXXABI_HIDDEN bool can_catch_nested(const __shim_type_info *) const;
 };
 
-#pragma GCC visibility pop
-
 }  // __cxxabiv1
 
 #endif  // __PRIVATE_TYPEINFO_H_
diff --git a/lib/libcxxabi/src/stdlib_exception.cpp b/lib/libcxxabi/src/stdlib_exception.cpp
new file mode 100644
index 00000000000..a8f71ab0ecc
--- /dev/null
+++ b/lib/libcxxabi/src/stdlib_exception.cpp
@@ -0,0 +1,103 @@
+//===---------------------------- exception.cpp ---------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is dual licensed under the MIT and the University of Illinois Open
+// Source Licenses. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+#define _LIBCPP_BUILDING_LIBRARY
+#define _LIBCPP_BUILDING_NEW
+#include <new>
+#include <exception>
+
+namespace std
+{
+
+// exception
+
+exception::~exception() _NOEXCEPT
+{
+}
+
+const char* exception::what() const _NOEXCEPT
+{
+  return "std::exception";
+}
+
+// bad_exception
+
+bad_exception::~bad_exception() _NOEXCEPT
+{
+}
+
+const char* bad_exception::what() const _NOEXCEPT
+{
+  return "std::bad_exception";
+}
+
+
+//  bad_alloc
+
+bad_alloc::bad_alloc() _NOEXCEPT
+{
+}
+
+bad_alloc::~bad_alloc() _NOEXCEPT
+{
+}
+
+const char*
+bad_alloc::what() const _NOEXCEPT
+{
+    return "std::bad_alloc";
+}
+
+// bad_array_new_length
+
+bad_array_new_length::bad_array_new_length() _NOEXCEPT
+{
+}
+
+bad_array_new_length::~bad_array_new_length() _NOEXCEPT
+{
+}
+
+const char*
+bad_array_new_length::what() const _NOEXCEPT
+{
+    return "bad_array_new_length";
+}
+
+// bad_array_length
+
+#ifndef _LIBCPP_BAD_ARRAY_LENGTH_DEFINED
+
+class _LIBCPP_EXCEPTION_ABI bad_array_length
+    : public bad_alloc
+{
+public:
+    bad_array_length() _NOEXCEPT;
+    virtual ~bad_array_length() _NOEXCEPT;
+    virtual const char* what() const _NOEXCEPT;
+};
+
+#endif  // _LIBCPP_BAD_ARRAY_LENGTH_DEFINED
+
+bad_array_length::bad_array_length() _NOEXCEPT
+{
+}
+
+bad_array_length::~bad_array_length() _NOEXCEPT
+{
+}
+
+const char*
+bad_array_length::what() const _NOEXCEPT
+{
+    return "bad_array_length";
+}
+
+
+}  // std
diff --git a/lib/libcxxabi/src/stdlib_new_delete.cpp b/lib/libcxxabi/src/stdlib_new_delete.cpp
new file mode 100644
index 00000000000..0e85f6ad299
--- /dev/null
+++ b/lib/libcxxabi/src/stdlib_new_delete.cpp
@@ -0,0 +1,264 @@
+//===--------------------- stdlib_new_delete.cpp --------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is dual licensed under the MIT and the University of Illinois Open
+// Source Licenses. See LICENSE.TXT for details.
+//
+//
+// This file implements the new and delete operators.
+//===----------------------------------------------------------------------===//
+
+#define _LIBCPP_BUILDING_NEW
+#define _LIBCPP_BUILDING_LIBRARY
+#include "__cxxabi_config.h"
+#include <new>
+#include <cstdlib>
+
+#if !defined(_THROW_BAD_ALLOC) || !defined(_NOEXCEPT) || !defined(_LIBCXXABI_WEAK)
+#error The _THROW_BAD_ALLOC, _NOEXCEPT, and _LIBCXXABI_WEAK libc++ macros must \
+       already be defined by libc++.
+#endif
+// Implement all new and delete operators as weak definitions
+// in this shared library, so that they can be overridden by programs
+// that define non-weak copies of the functions.
+
+_LIBCXXABI_WEAK
+void *
+operator new(std::size_t size) _THROW_BAD_ALLOC
+{
+    if (size == 0)
+        size = 1;
+    void* p;
+    while ((p = ::malloc(size)) == 0)
+    {
+        // If malloc fails and there is a new_handler,
+        // call it to try free up memory.
+        std::new_handler nh = std::get_new_handler();
+        if (nh)
+            nh();
+        else
+#ifndef _LIBCXXABI_NO_EXCEPTIONS
+            throw std::bad_alloc();
+#else
+            break;
+#endif
+    }
+    return p;
+}
+
+_LIBCXXABI_WEAK
+void*
+operator new(size_t size, const std::nothrow_t&) _NOEXCEPT
+{
+    void* p = 0;
+#ifndef _LIBCXXABI_NO_EXCEPTIONS
+    try
+    {
+#endif  // _LIBCXXABI_NO_EXCEPTIONS
+        p = ::operator new(size);
+#ifndef _LIBCXXABI_NO_EXCEPTIONS
+    }
+    catch (...)
+    {
+    }
+#endif  // _LIBCXXABI_NO_EXCEPTIONS
+    return p;
+}
+
+_LIBCXXABI_WEAK
+void*
+operator new[](size_t size) _THROW_BAD_ALLOC
+{
+    return ::operator new(size);
+}
+
+_LIBCXXABI_WEAK
+void*
+operator new[](size_t size, const std::nothrow_t&) _NOEXCEPT
+{
+    void* p = 0;
+#ifndef _LIBCXXABI_NO_EXCEPTIONS
+    try
+    {
+#endif  // _LIBCXXABI_NO_EXCEPTIONS
+        p = ::operator new[](size);
+#ifndef _LIBCXXABI_NO_EXCEPTIONS
+    }
+    catch (...)
+    {
+    }
+#endif  // _LIBCXXABI_NO_EXCEPTIONS
+    return p;
+}
+
+_LIBCXXABI_WEAK
+void
+operator delete(void* ptr) _NOEXCEPT
+{
+    if (ptr)
+        ::free(ptr);
+}
+
+_LIBCXXABI_WEAK
+void
+operator delete(void* ptr, const std::nothrow_t&) _NOEXCEPT
+{
+    ::operator delete(ptr);
+}
+
+_LIBCXXABI_WEAK
+void
+operator delete(void* ptr, size_t) _NOEXCEPT
+{
+    ::operator delete(ptr);
+}
+
+_LIBCXXABI_WEAK
+void
+operator delete[] (void* ptr) _NOEXCEPT
+{
+    ::operator delete(ptr);
+}
+
+_LIBCXXABI_WEAK
+void
+operator delete[] (void* ptr, const std::nothrow_t&) _NOEXCEPT
+{
+    ::operator delete[](ptr);
+}
+
+_LIBCXXABI_WEAK
+void
+operator delete[] (void* ptr, size_t) _NOEXCEPT
+{
+    ::operator delete[](ptr);
+}
+
+#if !defined(_LIBCPP_HAS_NO_ALIGNED_ALLOCATION)
+
+_LIBCXXABI_WEAK
+void *
+operator new(std::size_t size, std::align_val_t alignment) _THROW_BAD_ALLOC
+{
+    if (size == 0)
+        size = 1;
+    if (static_cast<size_t>(alignment) < sizeof(void*))
+      alignment = std::align_val_t(sizeof(void*));
+    void* p;
+#if defined(_LIBCPP_WIN32API)
+    while ((p = _aligned_malloc(size, static_cast<size_t>(alignment))) == nullptr)
+#else
+    while (::posix_memalign(&p, static_cast<size_t>(alignment), size) != 0)
+#endif
+    {
+        // If posix_memalign fails and there is a new_handler,
+        // call it to try free up memory.
+        std::new_handler nh = std::get_new_handler();
+        if (nh)
+            nh();
+        else {
+#ifndef _LIBCXXABI_NO_EXCEPTIONS
+            throw std::bad_alloc();
+#else
+            p = nullptr; // posix_memalign doesn't initialize 'p' on failure
+            break;
+#endif
+        }
+    }
+    return p;
+}
+
+_LIBCXXABI_WEAK
+void*
+operator new(size_t size, std::align_val_t alignment, const std::nothrow_t&) _NOEXCEPT
+{
+    void* p = 0;
+#ifndef _LIBCXXABI_NO_EXCEPTIONS
+    try
+    {
+#endif  // _LIBCXXABI_NO_EXCEPTIONS
+        p = ::operator new(size, alignment);
+#ifndef _LIBCXXABI_NO_EXCEPTIONS
+    }
+    catch (...)
+    {
+    }
+#endif  // _LIBCXXABI_NO_EXCEPTIONS
+    return p;
+}
+
+_LIBCXXABI_WEAK
+void*
+operator new[](size_t size, std::align_val_t alignment) _THROW_BAD_ALLOC
+{
+    return ::operator new(size, alignment);
+}
+
+_LIBCXXABI_WEAK
+void*
+operator new[](size_t size, std::align_val_t alignment, const std::nothrow_t&) _NOEXCEPT
+{
+    void* p = 0;
+#ifndef _LIBCXXABI_NO_EXCEPTIONS
+    try
+    {
+#endif  // _LIBCXXABI_NO_EXCEPTIONS
+        p = ::operator new[](size, alignment);
+#ifndef _LIBCXXABI_NO_EXCEPTIONS
+    }
+    catch (...)
+    {
+    }
+#endif  // _LIBCXXABI_NO_EXCEPTIONS
+    return p;
+}
+
+_LIBCXXABI_WEAK
+void
+operator delete(void* ptr, std::align_val_t) _NOEXCEPT
+{
+    if (ptr)
+#if defined(_LIBCPP_WIN32API)
+        ::_aligned_free(ptr);
+#else
+        ::free(ptr);
+#endif
+}
+
+_LIBCXXABI_WEAK
+void
+operator delete(void* ptr, std::align_val_t alignment, const std::nothrow_t&) _NOEXCEPT
+{
+    ::operator delete(ptr, alignment);
+}
+
+_LIBCXXABI_WEAK
+void
+operator delete(void* ptr, size_t, std::align_val_t alignment) _NOEXCEPT
+{
+    ::operator delete(ptr, alignment);
+}
+
+_LIBCXXABI_WEAK
+void
+operator delete[] (void* ptr, std::align_val_t alignment) _NOEXCEPT
+{
+    ::operator delete(ptr, alignment);
+}
+
+_LIBCXXABI_WEAK
+void
+operator delete[] (void* ptr, std::align_val_t alignment, const std::nothrow_t&) _NOEXCEPT
+{
+    ::operator delete[](ptr, alignment);
+}
+
+_LIBCXXABI_WEAK
+void
+operator delete[] (void* ptr, size_t, std::align_val_t alignment) _NOEXCEPT
+{
+    ::operator delete[](ptr, alignment);
+}
+
+#endif // !_LIBCPP_HAS_NO_ALIGNED_ALLOCATION
diff --git a/lib/libcxxabi/src/stdlib_stdexcept.cpp b/lib/libcxxabi/src/stdlib_stdexcept.cpp
new file mode 100644
index 00000000000..e3b7cd40658
--- /dev/null
+++ b/lib/libcxxabi/src/stdlib_stdexcept.cpp
@@ -0,0 +1,48 @@
+//===------------------------ stdexcept.cpp -------------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is dual licensed under the MIT and the University of Illinois Open
+// Source Licenses. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+#include "include/refstring.h"
+#include "stdexcept"
+#include "new"
+#include <cstdlib>
+#include <cstring>
+#include <cstdint>
+#include <cstddef>
+
+static_assert(sizeof(std::__libcpp_refstring) == sizeof(const char *), "");
+
+namespace std  // purposefully not using versioning namespace
+{
+
+logic_error::~logic_error() _NOEXCEPT {}
+
+const char*
+logic_error::what() const _NOEXCEPT
+{
+    return __imp_.c_str();
+}
+
+runtime_error::~runtime_error() _NOEXCEPT {}
+
+const char*
+runtime_error::what() const _NOEXCEPT
+{
+    return __imp_.c_str();
+}
+
+domain_error::~domain_error() _NOEXCEPT {}
+invalid_argument::~invalid_argument() _NOEXCEPT {}
+length_error::~length_error() _NOEXCEPT {}
+out_of_range::~out_of_range() _NOEXCEPT {}
+
+range_error::~range_error() _NOEXCEPT {}
+overflow_error::~overflow_error() _NOEXCEPT {}
+underflow_error::~underflow_error() _NOEXCEPT {}
+
+}  // std
diff --git a/lib/libcxxabi/src/stdlib_typeinfo.cpp b/lib/libcxxabi/src/stdlib_typeinfo.cpp
new file mode 100644
index 00000000000..9313be04a39
--- /dev/null
+++ b/lib/libcxxabi/src/stdlib_typeinfo.cpp
@@ -0,0 +1,53 @@
+//===----------------------------- typeinfo.cpp ---------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is dual licensed under the MIT and the University of Illinois Open
+// Source Licenses. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+#include <typeinfo>
+
+namespace std
+{
+
+// type_info
+
+type_info::~type_info()
+{
+}
+
+// bad_cast
+
+bad_cast::bad_cast() _NOEXCEPT
+{
+}
+
+bad_cast::~bad_cast() _NOEXCEPT
+{
+}
+
+const char*
+bad_cast::what() const _NOEXCEPT
+{
+  return "std::bad_cast";
+}
+
+// bad_typeid
+
+bad_typeid::bad_typeid() _NOEXCEPT
+{
+}
+
+bad_typeid::~bad_typeid() _NOEXCEPT
+{
+}
+
+const char*
+bad_typeid::what() const _NOEXCEPT
+{
+  return "std::bad_typeid";
+}
+
+}  // std