Implement Objective-C Related Result Type semantics.

Related result types apply Cocoa conventions to the type of message
sends and property accesses to Objective-C methods that are known to
always return objects whose type is the same as the type of the
receiving class (or a subclass thereof), such as +alloc and
-init. This tightens up static type safety for Objective-C, so that we
now diagnose mistakes like this:

t.m:4:10: warning: incompatible pointer types initializing 'NSSet *'
with an
      expression of type 'NSArray *' [-Wincompatible-pointer-types]
  NSSet *array = [[NSArray alloc] init];
         ^       ~~~~~~~~~~~~~~~~~~~~~~
/System/Library/Frameworks/Foundation.framework/Headers/NSObject.h:72:1:
note: 
      instance method 'init' is assumed to return an instance of its
      receiver
      type ('NSArray *')
- (id)init;
^

It also means that we get decent type inference when writing code in
Objective-C++0x:

  auto array = [[NSMutableArray alloc] initWithObjects:@"one",  @"two",nil];
  //    ^ now infers NSMutableArray* rather than id

llvm-svn: 132868

1 files changed, 1 insertions, 0 deletions

diff --git a/clang/lib/AST/DumpXML.cpp b/clang/lib/AST/DumpXML.cpp
index 12806aad1d7..dfe0119f597 100644
--- a/clang/lib/AST/DumpXML.cpp
+++ b/clang/lib/AST/DumpXML.cpp
@@ -848,6 +848,7 @@ struct XMLDumper : public XMLDeclVisitor<XMLDumper>,
     setFlag("variadic", D->isVariadic());
     setFlag("synthesized", D->isSynthesized());
     setFlag("defined", D->isDefined());
+    setFlag("related_result_type", D->hasRelatedResultType());
   }
   void visitObjCMethodDeclChildren(ObjCMethodDecl *D) {
     dispatch(D->getResultType());