Merge pull request #762 from vedantk/ubsan-20190619

[ubsan] Null-check and adjust TypeLoc before using it

Author: fredriss

clang/lib/CodeGen/CGCall.cpp

@@ -2996,7 +2996,7 @@ void CodeGenFunction::EmitReturnValueCheck(llvm::Value *RV) {
  } else {
 if (auto *DD = dyn_cast<DeclaratorDecl>(CurCodeDecl))
 if (auto *TSI = DD->getTypeSourceInfo())
-if (auto FTL = TSI->getTypeLoc().castAs<FunctionTypeLoc>())
+if (auto FTL = TSI->getTypeLoc().getAsAdjusted<FunctionTypeLoc>())
  AttrLoc = FTL.getReturnLoc().findNullabilityLoc();
  CheckKind = SanitizerKind::NullabilityReturn;
  Handler = SanitizerHandler::NullabilityReturn;

clang/test/CodeGenObjCXX/ubsan-nullability-return-notypeloc.mm

@@ -0,0 +1,19 @@
+// RUN: %clang_cc1 -fsanitize=nullability-return -emit-llvm %s -o - -triple x86_64-apple-macosx10.10.0 | FileCheck %s
+
+// CHECK: [[ATTR_LOC:@[0-9]+]] = {{.*}} global { {{.*}} i32 15, i32 38
+
+// CHECK-LABEL: define i8* @_Z3foov()
+// CHECK: [[CALL:%.*]] = call i8* @_Z6helperv()
+// CHECK: icmp ne i8* [[CALL]]
+// CHECK: call void @__ubsan_handle_nullability_return_v1_abort({{.*}}[[ATTR_LOC]]
+
+structS {
+using PtrTy = id;
+};
+
+#pragma clang assume_nonnull begin
+__attribute__((ns_returns_retained)) S::PtrTy foo(void) {
+extern S::PtrTy helper(void);
+returnhelper();
+}
+#pragma clang assume_nonnull end