From: Fariborz Jahanian <fjahanian@apple.com>
Date: Thu, 26 Jan 2012 00:45:38 +0000 (+0000)
Subject: objc: allow block pointer matching 'id' type when
X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=e7cff2c00c3d74e38984a4db5c48d7e303d3ab8e;p=clang

objc: allow block pointer matching 'id' type when
they show up as argument types of two block pointers.
// rdar://10734265


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@149007 91177308-0d34-0410-b5e6-96231b3b80d8
---

diff --git a/lib/AST/ASTContext.cpp b/lib/AST/ASTContext.cpp
index 27bbc72e88..5a7a73d3e8 100644
--- a/lib/AST/ASTContext.cpp
+++ b/lib/AST/ASTContext.cpp
@@ -5933,7 +5933,11 @@ QualType ASTContext::mergeTypes(QualType LHS, QualType RHS,
       if (ETy->getDecl()->getIntegerType() == LHSCan.getUnqualifiedType())
         return LHS;
     }
-
+    // allow block pointer type to match an 'id' type.
+    if (OfBlockPointer && !BlockReturnType &&
+        LHS->isObjCIdType() && RHS->isBlockPointerType())
+      return LHS;
+    
     return QualType();
   }
 
diff --git a/test/SemaObjC/block-id-as-block-argtype.m b/test/SemaObjC/block-id-as-block-argtype.m
new file mode 100644
index 0000000000..1b71a5c87b
--- /dev/null
+++ b/test/SemaObjC/block-id-as-block-argtype.m
@@ -0,0 +1,21 @@
+// RUN: %clang_cc1 %s -fsyntax-only -verify -fblocks
+// rdar://10734265
+
+@class NSObject;
+typedef void (^block1_t)(int arg);
+typedef void (^block2_t)(block1_t arg);
+typedef void (^block3_t)(NSObject *arg);
+typedef void (^block4_t)(id arg);
+
+void fn(block4_t arg); // expected-note {{passing argument to parameter 'arg' here}}
+
+int main() {
+    block1_t b1;
+    block2_t b2;
+    block3_t b3;
+    block3_t b4;
+    fn(b1);  // expected-error {{incompatible block pointer types passing 'block1_t' (aka 'void (^)(int)') to parameter of type 'block4_t' (aka 'void (^)(id)')}}
+    fn(b2);  // must succeed: block1_t *is* compatible with id
+    fn(b3);  // succeeds: NSObject* compatible with id
+    fn(b4);  // succeeds: id compatible with id
+}