[ubsan] Diagnose noreturn functions which return
Diagnose 'unreachable' UB when a noreturn function returns.
1. Insert a check at the end of functions marked noreturn.
2. A decl may be marked noreturn in the caller TU, but not marked in
the TU where it's defined. To diagnose this scenario, strip away the
noreturn attribute on the callee and insert check after calls to it.
Testing: check-clang, check-ubsan, check-ubsan-minimal, D40700
rdar://33660464
Differential Revision: https://reviews.llvm.org/D40698
llvm-svn: 321231
diff --git a/clang/lib/CodeGen/CGBuiltin.cpp b/clang/lib/CodeGen/CGBuiltin.cpp
index 01cc0187..d67f2fe 100644
--- a/clang/lib/CodeGen/CGBuiltin.cpp
+++ b/clang/lib/CodeGen/CGBuiltin.cpp
@@ -1432,14 +1432,7 @@
case Builtin::BI__debugbreak:
return RValue::get(EmitTrapCall(Intrinsic::debugtrap));
case Builtin::BI__builtin_unreachable: {
- if (SanOpts.has(SanitizerKind::Unreachable)) {
- SanitizerScope SanScope(this);
- EmitCheck(std::make_pair(static_cast<llvm::Value *>(Builder.getFalse()),
- SanitizerKind::Unreachable),
- SanitizerHandler::BuiltinUnreachable,
- EmitCheckSourceLocation(E->getExprLoc()), None);
- } else
- Builder.CreateUnreachable();
+ EmitUnreachable(E->getExprLoc());
// We do need to preserve an insertion point.
EmitBlock(createBasicBlock("unreachable.cont"));