The following patch adds __attribute__((no_address_safety_analysis)) which will allow to disable

address safety analysis (such as e.g. AddressSanitizer or SAFECode) for a specific function.

When building with AddressSanitizer, add AddressSafety function attribute to every generated function
except for those that have __attribute__((no_address_safety_analysis)).

With this patch we will be able to
1. disable AddressSanitizer for a particular function
2. disable AddressSanitizer-hostile optimizations (such as some cases of load widening) when AddressSanitizer is on.

llvm-svn: 148842

1 files changed, 8 insertions, 0 deletions

diff --git a/clang/lib/CodeGen/CodeGenModule.cpp b/clang/lib/CodeGen/CodeGenModule.cpp
index c54b904abcb..67059016f7d 100644
--- a/clang/lib/CodeGen/CodeGenModule.cpp
+++ b/clang/lib/CodeGen/CodeGenModule.cpp
@@ -1019,6 +1019,14 @@ CodeGenModule::GetOrCreateLLVMFunction(StringRef MangledName,
   if (ExtraAttrs != llvm::Attribute::None)
     F->addFnAttr(ExtraAttrs);
 
+  if (Features.AddressSanitizer) {
+    // When AddressSanitizer is enabled, set AddressSafety attribute
+    // unless __attribute__((no_address_safety_analysis)) is used.
+    const FunctionDecl *FD = cast_or_null<FunctionDecl>(D.getDecl());
+    if (!FD || !FD->hasAttr<NoAddressSafetyAnalysisAttr>())
+      F->addFnAttr(llvm::Attribute::AddressSafety);
+  }
+
   // This is the first use or definition of a mangled name.  If there is a
   // deferred decl with this name, remember that we need to emit it at the end
   // of the file.