diff options
Diffstat (limited to 'clang/lib')
| -rw-r--r-- | clang/lib/CodeGen/CGExpr.cpp | 12 |
1 files changed, 11 insertions, 1 deletions
diff --git a/clang/lib/CodeGen/CGExpr.cpp b/clang/lib/CodeGen/CGExpr.cpp index 265ef27a46b..b5d6c659e9e 100644 --- a/clang/lib/CodeGen/CGExpr.cpp +++ b/clang/lib/CodeGen/CGExpr.cpp @@ -533,6 +533,15 @@ bool CodeGenFunction::sanitizePerformTypeCheck() const { SanOpts.has(SanitizerKind::Vptr); } +/// Check if a runtime null check for \p Ptr can be omitted. +static bool canOmitPointerNullCheck(llvm::Value *Ptr) { + // Note: do not perform any constant-folding in this function. That is best + // left to the IR builder. + + // Pointers to alloca'd memory are non-null. + return isa<llvm::AllocaInst>(Ptr->stripPointerCastsNoFollowAliases()); +} + void CodeGenFunction::EmitTypeCheck(TypeCheckKind TCK, SourceLocation Loc, llvm::Value *Ptr, QualType Ty, CharUnits Alignment, @@ -554,7 +563,8 @@ void CodeGenFunction::EmitTypeCheck(TypeCheckKind TCK, SourceLocation Loc, bool AllowNullPointers = TCK == TCK_DowncastPointer || TCK == TCK_Upcast || TCK == TCK_UpcastToVirtualBase; if ((SanOpts.has(SanitizerKind::Null) || AllowNullPointers) && - !SkippedChecks.has(SanitizerKind::Null)) { + !SkippedChecks.has(SanitizerKind::Null) && + !canOmitPointerNullCheck(Ptr)) { // The glvalue must not be an empty glvalue. llvm::Value *IsNonNull = Builder.CreateIsNotNull(Ptr); |
