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




git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@132868 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 3 insertions, 0 deletions

diff --git a/lib/AST/DeclObjC.cpp b/lib/AST/DeclObjC.cpp
index 24d281e8b6..e2c4f38ff9 100644
--- a/lib/AST/DeclObjC.cpp
+++ b/lib/AST/DeclObjC.cpp
@@ -339,12 +339,14 @@ ObjCMethodDecl *ObjCMethodDecl::Create(ASTContext &C,
                                        bool isSynthesized,
                                        bool isDefined,
                                        ImplementationControl impControl,
+                                       bool HasRelatedResultType,
                                        unsigned numSelectorArgs) {
   return new (C) ObjCMethodDecl(beginLoc, endLoc,
                                 SelInfo, T, ResultTInfo, contextDecl,
                                 isInstance,
                                 isVariadic, isSynthesized, isDefined,
                                 impControl,
+                                HasRelatedResultType,
                                 numSelectorArgs);
 }
 
@@ -446,6 +448,7 @@ ObjCMethodFamily ObjCMethodDecl::getMethodFamily() const {
   case OMF_release:
   case OMF_autorelease:
   case OMF_retainCount:
+  case OMF_self:
     if (!isInstanceMethod())
       family = OMF_None;
     break;