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-rw-r--r--clang/lib/CodeGen/CodeGenModule.cpp12
1 files changed, 12 insertions, 0 deletions
diff --git a/clang/lib/CodeGen/CodeGenModule.cpp b/clang/lib/CodeGen/CodeGenModule.cpp
index c5eb14e..1085f45 100644
--- a/clang/lib/CodeGen/CodeGenModule.cpp
+++ b/clang/lib/CodeGen/CodeGenModule.cpp
@@ -83,6 +83,7 @@ static llvm::cl::opt<bool> LimitedCoverage(
llvm::cl::desc("Emit limited coverage mapping information (experimental)"));
static const char AnnotationSection[] = "llvm.metadata";
+static constexpr auto ErrnoTBAAMDName = "llvm.errno.tbaa";
static CGCXXABI *createCXXABI(CodeGenModule &CGM) {
switch (CGM.getContext().getCXXABIKind()) {
@@ -1583,6 +1584,17 @@ void CodeGenModule::Release() {
}
}
}
+
+ // Emit `!llvm.errno.tbaa`, a module-level metadata that specifies the TBAA
+ // for an int access. This allows LLVM to reason about what memory can be
+ // accessed by certain library calls that only touch errno.
+ if (TBAA) {
+ TBAAAccessInfo TBAAInfo = getTBAAAccessInfo(Context.IntTy);
+ if (llvm::MDNode *IntegerNode = getTBAAAccessTagInfo(TBAAInfo)) {
+ auto *ErrnoTBAAMD = TheModule.getOrInsertNamedMetadata(ErrnoTBAAMDName);
+ ErrnoTBAAMD->addOperand(IntegerNode);
+ }
+ }
}
void CodeGenModule::EmitOpenCLMetadata() {