Revert "[Sanitizers] UBSan unreachable incompatible with ASan in the presence of `noreturn` calls"

This reverts commit r352690. This causes clang to crash. Sent reproducer to the
author in the orginal commit.

llvm-svn: 352755

2 files changed, 2 insertions, 15 deletions

diff --git a/clang/lib/CodeGen/CGCall.cpp b/clang/lib/CodeGen/CGCall.cpp
index 655c75c01f6..893a6f2f902 100644
--- a/clang/lib/CodeGen/CGCall.cpp
+++ b/clang/lib/CodeGen/CGCall.cpp
@@ -4398,23 +4398,10 @@ RValue CodeGenFunction::EmitCall(const CGFunctionInfo &CallInfo,
 
     // Strip away the noreturn attribute to better diagnose unreachable UB.
     if (SanOpts.has(SanitizerKind::Unreachable)) {
-      // Also remove from function since CI->hasFnAttr(..) also checks attributes
-      // of the called function.
       if (auto *F = CI->getCalledFunction())
         F->removeFnAttr(llvm::Attribute::NoReturn);
       CI->removeAttribute(llvm::AttributeList::FunctionIndex,
                           llvm::Attribute::NoReturn);
-
-      // Avoid incompatibility with ASan which relies on the `noreturn`
-      // attribute to insert handler calls.
-      if (SanOpts.has(SanitizerKind::Address)) {
-        SanitizerScope SanScope(this);
-        Builder.SetInsertPoint(CI);
-        auto *FnType = llvm::FunctionType::get(CGM.VoidTy, /*isVarArg=*/false);
-        auto *Fn = CGM.CreateRuntimeFunction(FnType, "__asan_handle_no_return");
-        EmitNounwindRuntimeCall(Fn);
-        Builder.SetInsertPoint(CI->getParent());
-      }
     }
 
     EmitUnreachable(Loc);
diff --git a/clang/lib/CodeGen/CodeGenFunction.h b/clang/lib/CodeGen/CodeGenFunction.h
index 575a500c29d..a989a0e46ca 100644
--- a/clang/lib/CodeGen/CodeGenFunction.h
+++ b/clang/lib/CodeGen/CodeGenFunction.h
@@ -4084,8 +4084,8 @@ public:
   /// passing to a runtime sanitizer handler.
   llvm::Constant *EmitCheckSourceLocation(SourceLocation Loc);
 
-  /// Create a basic block that will either trap or call a handler function in
-  /// the UBSan runtime with the provided arguments, and create a conditional
+  /// Create a basic block that will call a handler function in a
+  /// sanitizer runtime with the provided arguments, and create a conditional
   /// branch to it.
   void EmitCheck(ArrayRef<std::pair<llvm::Value *, SanitizerMask>> Checked,
                  SanitizerHandler Check, ArrayRef<llvm::Constant *> StaticArgs,