From 70133b5b4ad863f7d73fabfaf799b2f4e30d98ec Mon Sep 17 00:00:00 2001
From: John McCall <rjmccall@apple.com>
Date: Wed, 8 May 2013 03:34:22 +0000
Subject: [PATCH] In block enum-return inference, don't die on loads of enum
 lvalues.

More of rdar://13200889.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@181390 91177308-0d34-0410-b5e6-96231b3b80d8
---
 lib/Sema/SemaLambda.cpp |  7 ++++---
 test/SemaObjC/blocks.m  | 10 ++++++++++
 2 files changed, 14 insertions(+), 3 deletions(-)

diff --git a/lib/Sema/SemaLambda.cpp b/lib/Sema/SemaLambda.cpp
index c7ba3cc822..24388dd0f5 100644
--- a/lib/Sema/SemaLambda.cpp
+++ b/lib/Sema/SemaLambda.cpp
@@ -275,11 +275,12 @@ static EnumDecl *findEnumForBlockReturn(Expr *E) {
   //   - it is an implicit integral conversion applied to an
   //     enumerator-like expression of type T or
   if (ImplicitCastExpr *ICE = dyn_cast<ImplicitCastExpr>(E)) {
-    // We can only see integral conversions in valid enumerator-like
-    // expressions.
+    // We can sometimes see integral conversions in valid
+    // enumerator-like expressions.
     if (ICE->getCastKind() == CK_IntegralCast)
       return findEnumForBlockReturn(ICE->getSubExpr());
-    return 0;
+
+    // Otherwise, just rely on the type.
   }
 
   //   - it is an expression of that formal enum type.
diff --git a/test/SemaObjC/blocks.m b/test/SemaObjC/blocks.m
index b523e4c916..65434698a8 100644
--- a/test/SemaObjC/blocks.m
+++ b/test/SemaObjC/blocks.m
@@ -86,9 +86,11 @@ typedef enum CStyleEnum (^cse_block_t)();
 
 void testCStyleEnumInference(bool arg) {
   cse_block_t a;
+  enum CStyleEnum value;
 
   // No warnings here.
   a = ^{ return getCSE(); };
+  a = ^{ return value; };
 
   a = ^{ // expected-error {{incompatible block pointer types assigning to 'cse_block_t' (aka 'enum CStyleEnum (^)()') from 'int (^)(void)'}}
     return 1;
@@ -102,6 +104,7 @@ void testCStyleEnumInference(bool arg) {
   // No warnings here.
   a = ^{ if (arg) return CSE_Value; else return getCSE();  };
   a = ^{ if (arg) return getCSE();  else return CSE_Value; };
+  a = ^{ if (arg) return value;     else return CSE_Value; };
 
   // These two blocks actually return 'int'
   a = ^{ // expected-error {{incompatible block pointer types assigning to 'cse_block_t' (aka 'enum CStyleEnum (^)()') from 'int (^)(void)'}}
@@ -118,6 +121,13 @@ void testCStyleEnumInference(bool arg) {
       return 1;
   };
 
+  a = ^{ // expected-error {{incompatible block pointer types assigning to 'cse_block_t' (aka 'enum CStyleEnum (^)()') from 'int (^)(void)'}}
+    if (arg)
+      return 1;
+    else
+      return value; // expected-error {{return type 'enum CStyleEnum' must match previous return type 'int'}}
+  };
+
   // rdar://13200889
   extern void check_enum(void);
   a = ^{
-- 
2.40.0