[UBSan] Add !nosanitize metadata to the code generated by UBSan.

This is used to mark the instructions emitted by Clang to implement
variety of UBSan checks. Generally, we don't want to instrument these
instructions with another sanitizers (like ASan).

Reviewed in http://reviews.llvm.org/D4544

llvm-svn: 213291

1 files changed, 3 insertions, 2 deletions

diff --git a/clang/lib/CodeGen/CGBuiltin.cpp b/clang/lib/CodeGen/CGBuiltin.cpp
index 4bdc87e2d42..4f68b347dbf 100644
--- a/clang/lib/CodeGen/CGBuiltin.cpp
+++ b/clang/lib/CodeGen/CGBuiltin.cpp
@@ -447,11 +447,12 @@ RValue CodeGenFunction::EmitBuiltinExpr(const FunctionDecl *FD,
     return RValue::get(Builder.CreateCall(F));
   }
   case Builtin::BI__builtin_unreachable: {
-    if (SanOpts->Unreachable)
+    if (SanOpts->Unreachable) {
+      SanitizerScope SanScope(this);
       EmitCheck(Builder.getFalse(), "builtin_unreachable",
                 EmitCheckSourceLocation(E->getExprLoc()),
                 ArrayRef<llvm::Value *>(), CRK_Unrecoverable);
-    else
+    } else
       Builder.CreateUnreachable();
 
     // We do need to preserve an insertion point.