1 files changed, 244 insertions, 0 deletions
diff --git a/gnu/llvm/lib/Support/Windows/Memory.inc b/gnu/llvm/lib/Support/Windows/Memory.inc
new file mode 100644
index 00000000000..7eab9ff3afd
--- /dev/null
+++ b/gnu/llvm/lib/Support/Windows/Memory.inc
@@ -0,0 +1,244 @@
+//===- Win32/Memory.cpp - Win32 Memory Implementation -----------*- C++ -*-===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This file provides the Win32 specific implementation of various Memory
+// management utilities
+//
+//===----------------------------------------------------------------------===//
+
+#include "llvm/Support/DataTypes.h"
+#include "llvm/Support/ErrorHandling.h"
+#include "llvm/Support/Process.h"
+#include "llvm/Support/WindowsError.h"
+
+// The Windows.h header must be the last one included.
+#include "WindowsSupport.h"
+
+namespace {
+
+DWORD getWindowsProtectionFlags(unsigned Flags) {
+  switch (Flags) {
+  // Contrary to what you might expect, the Windows page protection flags
+  // are not a bitwise combination of RWX values
+  case llvm::sys::Memory::MF_READ:
+    return PAGE_READONLY;
+  case llvm::sys::Memory::MF_WRITE:
+    // Note: PAGE_WRITE is not supported by VirtualProtect
+    return PAGE_READWRITE;
+  case llvm::sys::Memory::MF_READ|llvm::sys::Memory::MF_WRITE:
+    return PAGE_READWRITE;
+  case llvm::sys::Memory::MF_READ|llvm::sys::Memory::MF_EXEC:
+    return PAGE_EXECUTE_READ;
+  case llvm::sys::Memory::MF_READ |
+         llvm::sys::Memory::MF_WRITE |
+         llvm::sys::Memory::MF_EXEC:
+    return PAGE_EXECUTE_READWRITE;
+  case llvm::sys::Memory::MF_EXEC:
+    return PAGE_EXECUTE;
+  default:
+    llvm_unreachable("Illegal memory protection flag specified!");
+  }
+  // Provide a default return value as required by some compilers.
+  return PAGE_NOACCESS;
+}
+
+size_t getAllocationGranularity() {
+  SYSTEM_INFO  Info;
+  ::GetSystemInfo(&Info);
+  if (Info.dwPageSize > Info.dwAllocationGranularity)
+    return Info.dwPageSize;
+  else
+    return Info.dwAllocationGranularity;
+}
+
+} // namespace
+
+namespace llvm {
+namespace sys {
+
+//===----------------------------------------------------------------------===//
+//=== WARNING: Implementation here must contain only Win32 specific code
+//===          and must not be UNIX code
+//===----------------------------------------------------------------------===//
+
+MemoryBlock Memory::allocateMappedMemory(size_t NumBytes,
+                                         const MemoryBlock *const NearBlock,
+                                         unsigned Flags,
+                                         std::error_code &EC) {
+  EC = std::error_code();
+  if (NumBytes == 0)
+    return MemoryBlock();
+
+  // While we'd be happy to allocate single pages, the Windows allocation
+  // granularity may be larger than a single page (in practice, it is 64K)
+  // so mapping less than that will create an unreachable fragment of memory.
+  // Avoid using one-time initialization of static locals here, since they
+  // aren't thread safe with MSVC.
+  static volatile size_t GranularityCached;
+  size_t Granularity = GranularityCached;
+  if (Granularity == 0) {
+    Granularity = getAllocationGranularity();
+    GranularityCached = Granularity;
+  }
+
+  const size_t NumBlocks = (NumBytes+Granularity-1)/Granularity;
+
+  uintptr_t Start = NearBlock ? reinterpret_cast<uintptr_t>(NearBlock->base()) +
+                                NearBlock->size()
+                           : 0;
+
+  // If the requested address is not aligned to the allocation granularity,
+  // round up to get beyond NearBlock. VirtualAlloc would have rounded down.
+  if (Start && Start % Granularity != 0)
+    Start += Granularity - Start % Granularity;
+
+  DWORD Protect = getWindowsProtectionFlags(Flags);
+
+  void *PA = ::VirtualAlloc(reinterpret_cast<void*>(Start),
+                            NumBlocks*Granularity,
+                            MEM_RESERVE | MEM_COMMIT, Protect);
+  if (PA == NULL) {
+    if (NearBlock) {
+      // Try again without the NearBlock hint
+      return allocateMappedMemory(NumBytes, NULL, Flags, EC);
+    }
+    EC = mapWindowsError(::GetLastError());
+    return MemoryBlock();
+  }
+
+  MemoryBlock Result;
+  Result.Address = PA;
+  Result.Size = NumBlocks*Granularity;
+
+  if (Flags & MF_EXEC)
+    Memory::InvalidateInstructionCache(Result.Address, Result.Size);
+
+  return Result;
+}
+
+  std::error_code Memory::releaseMappedMemory(MemoryBlock &M) {
+  if (M.Address == 0 || M.Size == 0)
+    return std::error_code();
+
+  if (!VirtualFree(M.Address, 0, MEM_RELEASE))
+    return mapWindowsError(::GetLastError());
+
+  M.Address = 0;
+  M.Size = 0;
+
+  return std::error_code();
+}
+
+  std::error_code Memory::protectMappedMemory(const MemoryBlock &M,
+                                       unsigned Flags) {
+  if (M.Address == 0 || M.Size == 0)
+    return std::error_code();
+
+  DWORD Protect = getWindowsProtectionFlags(Flags);
+
+  DWORD OldFlags;
+  if (!VirtualProtect(M.Address, M.Size, Protect, &OldFlags))
+    return mapWindowsError(::GetLastError());
+
+  if (Flags & MF_EXEC)
+    Memory::InvalidateInstructionCache(M.Address, M.Size);
+
+  return std::error_code();
+}
+
+/// InvalidateInstructionCache - Before the JIT can run a block of code
+/// that has been emitted it must invalidate the instruction cache on some
+/// platforms.
+void Memory::InvalidateInstructionCache(
+    const void *Addr, size_t Len) {
+  FlushInstructionCache(GetCurrentProcess(), Addr, Len);
+}
+
+
+MemoryBlock Memory::AllocateRWX(size_t NumBytes,
+                                const MemoryBlock *NearBlock,
+                                std::string *ErrMsg) {
+  MemoryBlock MB;
+  std::error_code EC;
+  MB = allocateMappedMemory(NumBytes, NearBlock,
+                            MF_READ|MF_WRITE|MF_EXEC, EC);
+  if (EC != std::error_code() && ErrMsg) {
+    MakeErrMsg(ErrMsg, EC.message());
+  }
+  return MB;
+}
+
+bool Memory::ReleaseRWX(MemoryBlock &M, std::string *ErrMsg) {
+  std::error_code EC = releaseMappedMemory(M);
+  if (EC == std::error_code())
+    return false;
+  MakeErrMsg(ErrMsg, EC.message());
+  return true;
+}
+
+static DWORD getProtection(const void *addr) {
+  MEMORY_BASIC_INFORMATION info;
+  if (sizeof(info) == ::VirtualQuery(addr, &info, sizeof(info))) {
+    return info.Protect;
+  }
+  return 0;
+}
+
+bool Memory::setWritable(MemoryBlock &M, std::string *ErrMsg) {
+  if (!setRangeWritable(M.Address, M.Size)) {
+    return MakeErrMsg(ErrMsg, "Cannot set memory to writeable");
+  }
+  return true;
+}
+
+bool Memory::setExecutable(MemoryBlock &M, std::string *ErrMsg) {
+  if (!setRangeExecutable(M.Address, M.Size)) {
+    return MakeErrMsg(ErrMsg, "Cannot set memory to executable");
+  }
+  return true;
+}
+
+bool Memory::setRangeWritable(const void *Addr, size_t Size) {
+  DWORD prot = getProtection(Addr);
+  if (!prot)
+    return false;
+
+  if (prot == PAGE_EXECUTE || prot == PAGE_EXECUTE_READ) {
+    prot = PAGE_EXECUTE_READWRITE;
+  } else if (prot == PAGE_NOACCESS || prot == PAGE_READONLY) {
+    prot = PAGE_READWRITE;
+  }
+
+  DWORD oldProt;
+  Memory::InvalidateInstructionCache(Addr, Size);
+  return ::VirtualProtect(const_cast<LPVOID>(Addr), Size, prot, &oldProt)
+            == TRUE;
+}
+
+bool Memory::setRangeExecutable(const void *Addr, size_t Size) {
+  DWORD prot = getProtection(Addr);
+  if (!prot)
+    return false;
+
+  if (prot == PAGE_NOACCESS) {
+    prot = PAGE_EXECUTE;
+  } else if (prot == PAGE_READONLY) {
+    prot = PAGE_EXECUTE_READ;
+  } else if (prot == PAGE_READWRITE) {
+    prot = PAGE_EXECUTE_READWRITE;
+  }
+
+  DWORD oldProt;
+  Memory::InvalidateInstructionCache(Addr, Size);
+  return ::VirtualProtect(const_cast<LPVOID>(Addr), Size, prot, &oldProt)
+            == TRUE;
+}
+
+} // namespace sys
+} // namespace llvm