Import LLVM 10.0.0 release including clang, lld and lldb.

ok hackroom
tested by plenty

1 files changed, 511 insertions, 0 deletions

diff --git a/gnu/llvm/clang/lib/StaticAnalyzer/Checkers/UnixAPIChecker.cpp b/gnu/llvm/clang/lib/StaticAnalyzer/Checkers/UnixAPIChecker.cpp
new file mode 100644
index 00000000000..f4e225d836f
--- /dev/null
+++ b/gnu/llvm/clang/lib/StaticAnalyzer/Checkers/UnixAPIChecker.cpp
@@ -0,0 +1,511 @@
+//= UnixAPIChecker.h - Checks preconditions for various Unix APIs --*- C++ -*-//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+//
+// This defines UnixAPIChecker, which is an assortment of checks on calls
+// to various, widely used UNIX/Posix functions.
+//
+//===----------------------------------------------------------------------===//
+
+#include "clang/StaticAnalyzer/Checkers/BuiltinCheckerRegistration.h"
+#include "clang/Basic/TargetInfo.h"
+#include "clang/StaticAnalyzer/Core/BugReporter/BugType.h"
+#include "clang/StaticAnalyzer/Core/Checker.h"
+#include "clang/StaticAnalyzer/Core/CheckerManager.h"
+#include "clang/StaticAnalyzer/Core/PathSensitive/CheckerContext.h"
+#include "llvm/ADT/Optional.h"
+#include "llvm/ADT/STLExtras.h"
+#include "llvm/ADT/SmallString.h"
+#include "llvm/Support/raw_ostream.h"
+
+using namespace clang;
+using namespace ento;
+
+enum class OpenVariant {
+  /// The standard open() call:
+  ///    int open(const char *path, int oflag, ...);
+  Open,
+
+  /// The variant taking a directory file descriptor and a relative path:
+  ///    int openat(int fd, const char *path, int oflag, ...);
+  OpenAt
+};
+
+namespace {
+
+class UnixAPIMisuseChecker : public Checker< check::PreStmt<CallExpr> > {
+  mutable std::unique_ptr<BugType> BT_open, BT_pthreadOnce;
+  mutable Optional<uint64_t> Val_O_CREAT;
+
+public:
+  DefaultBool CheckMisuse, CheckPortability;
+
+  void checkPreStmt(const CallExpr *CE, CheckerContext &C) const;
+
+  void CheckOpen(CheckerContext &C, const CallExpr *CE) const;
+  void CheckOpenAt(CheckerContext &C, const CallExpr *CE) const;
+  void CheckPthreadOnce(CheckerContext &C, const CallExpr *CE) const;
+
+  void CheckOpenVariant(CheckerContext &C,
+                        const CallExpr *CE, OpenVariant Variant) const;
+
+  void ReportOpenBug(CheckerContext &C,
+                     ProgramStateRef State,
+                     const char *Msg,
+                     SourceRange SR) const;
+
+};
+
+class UnixAPIPortabilityChecker : public Checker< check::PreStmt<CallExpr> > {
+public:
+  void checkPreStmt(const CallExpr *CE, CheckerContext &C) const;
+
+private:
+  mutable std::unique_ptr<BugType> BT_mallocZero;
+
+  void CheckCallocZero(CheckerContext &C, const CallExpr *CE) const;
+  void CheckMallocZero(CheckerContext &C, const CallExpr *CE) const;
+  void CheckReallocZero(CheckerContext &C, const CallExpr *CE) const;
+  void CheckReallocfZero(CheckerContext &C, const CallExpr *CE) const;
+  void CheckAllocaZero(CheckerContext &C, const CallExpr *CE) const;
+  void CheckAllocaWithAlignZero(CheckerContext &C, const CallExpr *CE) const;
+  void CheckVallocZero(CheckerContext &C, const CallExpr *CE) const;
+
+  bool ReportZeroByteAllocation(CheckerContext &C,
+                                ProgramStateRef falseState,
+                                const Expr *arg,
+                                const char *fn_name) const;
+  void BasicAllocationCheck(CheckerContext &C,
+                            const CallExpr *CE,
+                            const unsigned numArgs,
+                            const unsigned sizeArg,
+                            const char *fn) const;
+};
+
+} //end anonymous namespace
+
+static void LazyInitialize(const CheckerBase *Checker,
+                           std::unique_ptr<BugType> &BT,
+                           const char *name) {
+  if (BT)
+    return;
+  BT.reset(new BugType(Checker, name, categories::UnixAPI));
+}
+
+//===----------------------------------------------------------------------===//
+// "open" (man 2 open)
+//===----------------------------------------------------------------------===/
+
+void UnixAPIMisuseChecker::checkPreStmt(const CallExpr *CE,
+                                        CheckerContext &C) const {
+  const FunctionDecl *FD = C.getCalleeDecl(CE);
+  if (!FD || FD->getKind() != Decl::Function)
+    return;
+
+  // Don't treat functions in namespaces with the same name a Unix function
+  // as a call to the Unix function.
+  const DeclContext *NamespaceCtx = FD->getEnclosingNamespaceContext();
+  if (NamespaceCtx && isa<NamespaceDecl>(NamespaceCtx))
+    return;
+
+  StringRef FName = C.getCalleeName(FD);
+  if (FName.empty())
+    return;
+
+  if (FName == "open")
+    CheckOpen(C, CE);
+
+  else if (FName == "openat")
+    CheckOpenAt(C, CE);
+
+  else if (FName == "pthread_once")
+    CheckPthreadOnce(C, CE);
+}
+void UnixAPIMisuseChecker::ReportOpenBug(CheckerContext &C,
+                                         ProgramStateRef State,
+                                         const char *Msg,
+                                         SourceRange SR) const {
+  ExplodedNode *N = C.generateErrorNode(State);
+  if (!N)
+    return;
+
+  LazyInitialize(this, BT_open, "Improper use of 'open'");
+
+  auto Report = std::make_unique<PathSensitiveBugReport>(*BT_open, Msg, N);
+  Report->addRange(SR);
+  C.emitReport(std::move(Report));
+}
+
+void UnixAPIMisuseChecker::CheckOpen(CheckerContext &C,
+                                     const CallExpr *CE) const {
+  CheckOpenVariant(C, CE, OpenVariant::Open);
+}
+
+void UnixAPIMisuseChecker::CheckOpenAt(CheckerContext &C,
+                                       const CallExpr *CE) const {
+  CheckOpenVariant(C, CE, OpenVariant::OpenAt);
+}
+
+void UnixAPIMisuseChecker::CheckOpenVariant(CheckerContext &C,
+                                            const CallExpr *CE,
+                                            OpenVariant Variant) const {
+  // The index of the argument taking the flags open flags (O_RDONLY,
+  // O_WRONLY, O_CREAT, etc.),
+  unsigned int FlagsArgIndex;
+  const char *VariantName;
+  switch (Variant) {
+  case OpenVariant::Open:
+    FlagsArgIndex = 1;
+    VariantName = "open";
+    break;
+  case OpenVariant::OpenAt:
+    FlagsArgIndex = 2;
+    VariantName = "openat";
+    break;
+  };
+
+  // All calls should at least provide arguments up to the 'flags' parameter.
+  unsigned int MinArgCount = FlagsArgIndex + 1;
+
+  // If the flags has O_CREAT set then open/openat() require an additional
+  // argument specifying the file mode (permission bits) for the created file.
+  unsigned int CreateModeArgIndex = FlagsArgIndex + 1;
+
+  // The create mode argument should be the last argument.
+  unsigned int MaxArgCount = CreateModeArgIndex + 1;
+
+  ProgramStateRef state = C.getState();
+
+  if (CE->getNumArgs() < MinArgCount) {
+    // The frontend should issue a warning for this case, so this is a sanity
+    // check.
+    return;
+  } else if (CE->getNumArgs() == MaxArgCount) {
+    const Expr *Arg = CE->getArg(CreateModeArgIndex);
+    QualType QT = Arg->getType();
+    if (!QT->isIntegerType()) {
+      SmallString<256> SBuf;
+      llvm::raw_svector_ostream OS(SBuf);
+      OS << "The " << CreateModeArgIndex + 1
+         << llvm::getOrdinalSuffix(CreateModeArgIndex + 1)
+         << " argument to '" << VariantName << "' is not an integer";
+
+      ReportOpenBug(C, state,
+                    SBuf.c_str(),
+                    Arg->getSourceRange());
+      return;
+    }
+  } else if (CE->getNumArgs() > MaxArgCount) {
+    SmallString<256> SBuf;
+    llvm::raw_svector_ostream OS(SBuf);
+    OS << "Call to '" << VariantName << "' with more than " << MaxArgCount
+       << " arguments";
+
+    ReportOpenBug(C, state,
+                  SBuf.c_str(),
+                  CE->getArg(MaxArgCount)->getSourceRange());
+    return;
+  }
+
+  // The definition of O_CREAT is platform specific.  We need a better way
+  // of querying this information from the checking environment.
+  if (!Val_O_CREAT.hasValue()) {
+    if (C.getASTContext().getTargetInfo().getTriple().getVendor()
+                                                      == llvm::Triple::Apple)
+      Val_O_CREAT = 0x0200;
+    else {
+      // FIXME: We need a more general way of getting the O_CREAT value.
+      // We could possibly grovel through the preprocessor state, but
+      // that would require passing the Preprocessor object to the ExprEngine.
+      // See also: MallocChecker.cpp / M_ZERO.
+      return;
+    }
+  }
+
+  // Now check if oflags has O_CREAT set.
+  const Expr *oflagsEx = CE->getArg(FlagsArgIndex);
+  const SVal V = C.getSVal(oflagsEx);
+  if (!V.getAs<NonLoc>()) {
+    // The case where 'V' can be a location can only be due to a bad header,
+    // so in this case bail out.
+    return;
+  }
+  NonLoc oflags = V.castAs<NonLoc>();
+  NonLoc ocreateFlag = C.getSValBuilder()
+      .makeIntVal(Val_O_CREAT.getValue(), oflagsEx->getType()).castAs<NonLoc>();
+  SVal maskedFlagsUC = C.getSValBuilder().evalBinOpNN(state, BO_And,
+                                                      oflags, ocreateFlag,
+                                                      oflagsEx->getType());
+  if (maskedFlagsUC.isUnknownOrUndef())
+    return;
+  DefinedSVal maskedFlags = maskedFlagsUC.castAs<DefinedSVal>();
+
+  // Check if maskedFlags is non-zero.
+  ProgramStateRef trueState, falseState;
+  std::tie(trueState, falseState) = state->assume(maskedFlags);
+
+  // Only emit an error if the value of 'maskedFlags' is properly
+  // constrained;
+  if (!(trueState && !falseState))
+    return;
+
+  if (CE->getNumArgs() < MaxArgCount) {
+    SmallString<256> SBuf;
+    llvm::raw_svector_ostream OS(SBuf);
+    OS << "Call to '" << VariantName << "' requires a "
+       << CreateModeArgIndex + 1
+       << llvm::getOrdinalSuffix(CreateModeArgIndex + 1)
+       << " argument when the 'O_CREAT' flag is set";
+    ReportOpenBug(C, trueState,
+                  SBuf.c_str(),
+                  oflagsEx->getSourceRange());
+  }
+}
+
+//===----------------------------------------------------------------------===//
+// pthread_once
+//===----------------------------------------------------------------------===//
+
+void UnixAPIMisuseChecker::CheckPthreadOnce(CheckerContext &C,
+                                      const CallExpr *CE) const {
+
+  // This is similar to 'CheckDispatchOnce' in the MacOSXAPIChecker.
+  // They can possibly be refactored.
+
+  if (CE->getNumArgs() < 1)
+    return;
+
+  // Check if the first argument is stack allocated.  If so, issue a warning
+  // because that's likely to be bad news.
+  ProgramStateRef state = C.getState();
+  const MemRegion *R = C.getSVal(CE->getArg(0)).getAsRegion();
+  if (!R || !isa<StackSpaceRegion>(R->getMemorySpace()))
+    return;
+
+  ExplodedNode *N = C.generateErrorNode(state);
+  if (!N)
+    return;
+
+  SmallString<256> S;
+  llvm::raw_svector_ostream os(S);
+  os << "Call to 'pthread_once' uses";
+  if (const VarRegion *VR = dyn_cast<VarRegion>(R))
+    os << " the local variable '" << VR->getDecl()->getName() << '\'';
+  else
+    os << " stack allocated memory";
+  os << " for the \"control\" value.  Using such transient memory for "
+  "the control value is potentially dangerous.";
+  if (isa<VarRegion>(R) && isa<StackLocalsSpaceRegion>(R->getMemorySpace()))
+    os << "  Perhaps you intended to declare the variable as 'static'?";
+
+  LazyInitialize(this, BT_pthreadOnce, "Improper use of 'pthread_once'");
+
+  auto report =
+      std::make_unique<PathSensitiveBugReport>(*BT_pthreadOnce, os.str(), N);
+  report->addRange(CE->getArg(0)->getSourceRange());
+  C.emitReport(std::move(report));
+}
+
+//===----------------------------------------------------------------------===//
+// "calloc", "malloc", "realloc", "reallocf", "alloca" and "valloc"
+// with allocation size 0
+//===----------------------------------------------------------------------===//
+
+// FIXME: Eventually these should be rolled into the MallocChecker, but right now
+// they're more basic and valuable for widespread use.
+
+// Returns true if we try to do a zero byte allocation, false otherwise.
+// Fills in trueState and falseState.
+static bool IsZeroByteAllocation(ProgramStateRef state,
+                                 const SVal argVal,
+                                 ProgramStateRef *trueState,
+                                 ProgramStateRef *falseState) {
+  std::tie(*trueState, *falseState) =
+    state->assume(argVal.castAs<DefinedSVal>());
+
+  return (*falseState && !*trueState);
+}
+
+// Generates an error report, indicating that the function whose name is given
+// will perform a zero byte allocation.
+// Returns false if an error occurred, true otherwise.
+bool UnixAPIPortabilityChecker::ReportZeroByteAllocation(
+                                                    CheckerContext &C,
+                                                    ProgramStateRef falseState,
+                                                    const Expr *arg,
+                                                    const char *fn_name) const {
+  ExplodedNode *N = C.generateErrorNode(falseState);
+  if (!N)
+    return false;
+
+  LazyInitialize(this, BT_mallocZero,
+                 "Undefined allocation of 0 bytes (CERT MEM04-C; CWE-131)");
+
+  SmallString<256> S;
+  llvm::raw_svector_ostream os(S);
+  os << "Call to '" << fn_name << "' has an allocation size of 0 bytes";
+  auto report =
+      std::make_unique<PathSensitiveBugReport>(*BT_mallocZero, os.str(), N);
+
+  report->addRange(arg->getSourceRange());
+  bugreporter::trackExpressionValue(N, arg, *report);
+  C.emitReport(std::move(report));
+
+  return true;
+}
+
+// Does a basic check for 0-sized allocations suitable for most of the below
+// functions (modulo "calloc")
+void UnixAPIPortabilityChecker::BasicAllocationCheck(CheckerContext &C,
+                                                     const CallExpr *CE,
+                                                     const unsigned numArgs,
+                                                     const unsigned sizeArg,
+                                                     const char *fn) const {
+  // Sanity check for the correct number of arguments
+  if (CE->getNumArgs() != numArgs)
+    return;
+
+  // Check if the allocation size is 0.
+  ProgramStateRef state = C.getState();
+  ProgramStateRef trueState = nullptr, falseState = nullptr;
+  const Expr *arg = CE->getArg(sizeArg);
+  SVal argVal = C.getSVal(arg);
+
+  if (argVal.isUnknownOrUndef())
+    return;
+
+  // Is the value perfectly constrained to zero?
+  if (IsZeroByteAllocation(state, argVal, &trueState, &falseState)) {
+    (void) ReportZeroByteAllocation(C, falseState, arg, fn);
+    return;
+  }
+  // Assume the value is non-zero going forward.
+  assert(trueState);
+  if (trueState != state)
+    C.addTransition(trueState);
+}
+
+void UnixAPIPortabilityChecker::CheckCallocZero(CheckerContext &C,
+                                                const CallExpr *CE) const {
+  unsigned int nArgs = CE->getNumArgs();
+  if (nArgs != 2)
+    return;
+
+  ProgramStateRef state = C.getState();
+  ProgramStateRef trueState = nullptr, falseState = nullptr;
+
+  unsigned int i;
+  for (i = 0; i < nArgs; i++) {
+    const Expr *arg = CE->getArg(i);
+    SVal argVal = C.getSVal(arg);
+    if (argVal.isUnknownOrUndef()) {
+      if (i == 0)
+        continue;
+      else
+        return;
+    }
+
+    if (IsZeroByteAllocation(state, argVal, &trueState, &falseState)) {
+      if (ReportZeroByteAllocation(C, falseState, arg, "calloc"))
+        return;
+      else if (i == 0)
+        continue;
+      else
+        return;
+    }
+  }
+
+  // Assume the value is non-zero going forward.
+  assert(trueState);
+  if (trueState != state)
+    C.addTransition(trueState);
+}
+
+void UnixAPIPortabilityChecker::CheckMallocZero(CheckerContext &C,
+                                                const CallExpr *CE) const {
+  BasicAllocationCheck(C, CE, 1, 0, "malloc");
+}
+
+void UnixAPIPortabilityChecker::CheckReallocZero(CheckerContext &C,
+                                                 const CallExpr *CE) const {
+  BasicAllocationCheck(C, CE, 2, 1, "realloc");
+}
+
+void UnixAPIPortabilityChecker::CheckReallocfZero(CheckerContext &C,
+                                                  const CallExpr *CE) const {
+  BasicAllocationCheck(C, CE, 2, 1, "reallocf");
+}
+
+void UnixAPIPortabilityChecker::CheckAllocaZero(CheckerContext &C,
+                                                const CallExpr *CE) const {
+  BasicAllocationCheck(C, CE, 1, 0, "alloca");
+}
+
+void UnixAPIPortabilityChecker::CheckAllocaWithAlignZero(
+                                                     CheckerContext &C,
+                                                     const CallExpr *CE) const {
+  BasicAllocationCheck(C, CE, 2, 0, "__builtin_alloca_with_align");
+}
+
+void UnixAPIPortabilityChecker::CheckVallocZero(CheckerContext &C,
+                                                const CallExpr *CE) const {
+  BasicAllocationCheck(C, CE, 1, 0, "valloc");
+}
+
+void UnixAPIPortabilityChecker::checkPreStmt(const CallExpr *CE,
+                                             CheckerContext &C) const {
+  const FunctionDecl *FD = C.getCalleeDecl(CE);
+  if (!FD || FD->getKind() != Decl::Function)
+    return;
+
+  // Don't treat functions in namespaces with the same name a Unix function
+  // as a call to the Unix function.
+  const DeclContext *NamespaceCtx = FD->getEnclosingNamespaceContext();
+  if (NamespaceCtx && isa<NamespaceDecl>(NamespaceCtx))
+    return;
+
+  StringRef FName = C.getCalleeName(FD);
+  if (FName.empty())
+    return;
+
+  if (FName == "calloc")
+    CheckCallocZero(C, CE);
+
+  else if (FName == "malloc")
+    CheckMallocZero(C, CE);
+
+  else if (FName == "realloc")
+    CheckReallocZero(C, CE);
+
+  else if (FName == "reallocf")
+    CheckReallocfZero(C, CE);
+
+  else if (FName == "alloca" || FName ==  "__builtin_alloca")
+    CheckAllocaZero(C, CE);
+
+  else if (FName == "__builtin_alloca_with_align")
+    CheckAllocaWithAlignZero(C, CE);
+
+  else if (FName == "valloc")
+    CheckVallocZero(C, CE);
+}
+
+//===----------------------------------------------------------------------===//
+// Registration.
+//===----------------------------------------------------------------------===//
+
+#define REGISTER_CHECKER(CHECKERNAME)                                          \
+  void ento::register##CHECKERNAME(CheckerManager &mgr) {                      \
+    mgr.registerChecker<CHECKERNAME>();                                        \
+  }                                                                            \
+                                                                               \
+  bool ento::shouldRegister##CHECKERNAME(const LangOptions &LO) {              \
+    return true;                                                               \
+  }
+
+REGISTER_CHECKER(UnixAPIMisuseChecker)
+REGISTER_CHECKER(UnixAPIPortabilityChecker)