[Sema][ObjC] Warn about 'performSelector' calls with selectors

that return record or vector types

The performSelector family of methods from Foundation use objc_msgSend to
dispatch the selector invocations to objects. However, method calls to methods
that return record types might have to use the objc_msgSend_stret as the return
value won't find into the register. This is also supported by this sentence from
performSelector documentation: "The method should not have a significant return
value and should take a single argument of type id, or no arguments". This
commit adds a new warning that warns when a selector which corresponds to a
method that returns a record type is passed into performSelector.

rdar://12056271

Differential Revision: https://reviews.llvm.org/D30174

llvm-svn: 297019

1 files changed, 4 insertions, 2 deletions

diff --git a/clang/lib/Basic/IdentifierTable.cpp b/clang/lib/Basic/IdentifierTable.cpp
index af424cd9..5caa8a6 100644
--- a/clang/lib/Basic/IdentifierTable.cpp
+++ b/clang/lib/Basic/IdentifierTable.cpp
@@ -487,8 +487,10 @@ ObjCMethodFamily Selector::getMethodFamilyImpl(Selector sel) {
     if (name == "self") return OMF_self;
     if (name == "initialize") return OMF_initialize;
   }
- 
-  if (name == "performSelector") return OMF_performSelector;
+
+  if (name == "performSelector" || name == "performSelectorInBackground" ||
+      name == "performSelectorOnMainThread")
+    return OMF_performSelector;
 
   // The other method families may begin with a prefix of underscores.
   while (!name.empty() && name.front() == '_')