From 9d8ac61fec65b20472a4e6ad9b17472828029971 Mon Sep 17 00:00:00 2001
From: Akira Hatanaka <ahatanaka@apple.com>
Date: Wed, 17 Feb 2016 21:09:50 +0000
Subject: [PATCH] [CodeGen] Fix an assert in
 CodeGenFunction::EmitFunctionEpilog

The assert is triggered because isObjCRetainableType() is called on the
canonicalized return type that has been stripped of the typedefs and
attributes attached to it. To fix this assert, this commit gets the
original return type from CurCodeDecl or BlockInfo and uses it instead
of the canoicalized type.

rdar://problem/24470031

Differential Revision: http://reviews.llvm.org/D16914

llvm-svn: 261151
---
 clang/lib/CodeGen/CGCall.cpp                  | 20 ++++++++++-
 .../auto-release-result-assert.mm             | 35 +++++++++++++++++++
 2 files changed, 54 insertions(+), 1 deletion(-)
 create mode 100644 clang/test/CodeGenObjCXX/auto-release-result-assert.mm

diff --git a/clang/lib/CodeGen/CGCall.cpp b/clang/lib/CodeGen/CGCall.cpp
index 61b2fe78db73..281292f764c1 100644
--- a/clang/lib/CodeGen/CGCall.cpp
+++ b/clang/lib/CodeGen/CGCall.cpp
@@ -14,6 +14,7 @@
 
 #include "CGCall.h"
 #include "ABIInfo.h"
+#include "CGBlocks.h"
 #include "CGCXXABI.h"
 #include "CGCleanup.h"
 #include "CodeGenFunction.h"
@@ -2462,9 +2463,26 @@ void CodeGenFunction::EmitFunctionEpilog(const CGFunctionInfo &FI,
     // In ARC, end functions that return a retainable type with a call
     // to objc_autoreleaseReturnValue.
     if (AutoreleaseResult) {
+#ifndef NDEBUG
+      // Type::isObjCRetainabletype has to be called on a QualType that hasn't
+      // been stripped of the typedefs, so we cannot use RetTy here. Get the
+      // original return type of FunctionDecl, CurCodeDecl, and BlockDecl from
+      // CurCodeDecl or BlockInfo.
+      QualType RT;
+
+      if (auto *FD = dyn_cast<FunctionDecl>(CurCodeDecl))
+        RT = FD->getReturnType();
+      else if (auto *MD = dyn_cast<ObjCMethodDecl>(CurCodeDecl))
+        RT = MD->getReturnType();
+      else if (isa<BlockDecl>(CurCodeDecl))
+        RT = BlockInfo->BlockExpression->getFunctionType()->getReturnType();
+      else
+        llvm_unreachable("Unexpected function/method type");
+
       assert(getLangOpts().ObjCAutoRefCount &&
              !FI.isReturnsRetained() &&
-             RetTy->isObjCRetainableType());
+             RT->isObjCRetainableType());
+#endif
       RV = emitAutoreleaseOfResult(*this, RV);
     }
 
diff --git a/clang/test/CodeGenObjCXX/auto-release-result-assert.mm b/clang/test/CodeGenObjCXX/auto-release-result-assert.mm
new file mode 100644
index 000000000000..044dc9d7d99c
--- /dev/null
+++ b/clang/test/CodeGenObjCXX/auto-release-result-assert.mm
@@ -0,0 +1,35 @@
+// RUN: %clang_cc1 -triple x86_64-apple-darwin10 -emit-llvm -fblocks -fobjc-arc -o - %s | FileCheck %s
+
+// CHECK-LABEL: define %struct.S1* @_Z4foo1i(
+// CHECK: %[[CALL:[a-z0-9]+]] = call %struct.S1* @_Z4foo0i
+// CHECK: ret %struct.S1* %[[CALL]]
+
+// CHECK-LABEL: define %struct.S1* @_ZN2S22m1Ev(
+// CHECK: %[[CALL:[a-z0-9]+]] = call %struct.S1* @_Z4foo0i
+// CHECK: ret %struct.S1* %[[CALL]]
+
+// CHECK-LABEL: define internal %struct.S1* @Block1_block_invoke(
+// CHECK: %[[CALL:[a-z0-9]+]] = call %struct.S1* @_Z4foo0i
+// CHECK: ret %struct.S1* %[[CALL]]
+
+struct S1;
+
+typedef __attribute__((NSObject)) struct __attribute__((objc_bridge(id))) S1 * S1Ref;
+
+S1Ref foo0(int);
+
+struct S2 {
+  S1Ref m1();
+};
+
+S1Ref foo1(int a) {
+  return foo0(a);
+}
+
+S1Ref S2::m1() {
+  return foo0(0);
+}
+
+S1Ref (^Block1)(void) = ^{
+  return foo0(0);
+};