arc-objc++: Issue an arc specific diagnostic when overload resolution

fails because of lifetime differences of parameter and argument type.
// rdar://9790531

llvm-svn: 135593

clang/include/clang/Basic/DiagnosticSemaKinds.td

@@ -1595,6 +1595,17 @@ def note_ovl_candidate_bad_conv : Note<"candidate "
     "%select{%ordinal5 argument|object argument}4; "
     "%select{|dereference the argument with *|"
     "take the address of the argument with &}6">;
+def note_ovl_candidate_bad_arc_conv : Note<"candidate "
+    "%select{function|function|constructor|"
+    "function |function |constructor |"
+    "constructor (the implicit default constructor)|"
+    "constructor (the implicit copy constructor)|"
+    "constructor (the implicit move constructor)|"
+    "function (the implicit copy assignment operator)|"
+    "function (the implicit move assignment operator)|"
+    "constructor (inherited)}0%1"
+    " not viable: cannot implicitly convert argument of type %2 to %3 for "
+    "%select{%ordinal5 argument|object argument}4 under ARC">;
 def note_ovl_candidate_bad_addrspace : Note<"candidate "
     "%select{function|function|constructor|"
     "function |function |constructor |"

clang/lib/Sema/SemaOverload.cpp

@@ -6981,8 +6981,21 @@ void DiagnoseBadConversion(Sema &S, OverloadCandidate *Cand, unsigned I) {
     return;
   }
 
+  if (isa<ObjCObjectPointerType>(CFromTy) &&
+      isa<PointerType>(CToTy)) {
+      Qualifiers FromQs = CFromTy.getQualifiers();
+      Qualifiers ToQs = CToTy.getQualifiers();
+      if (FromQs.getObjCLifetime() != ToQs.getObjCLifetime()) {
+        S.Diag(Fn->getLocation(), diag::note_ovl_candidate_bad_arc_conv)
+        << (unsigned) FnKind << FnDesc
+        << (FromExpr ? FromExpr->getSourceRange() : SourceRange())
+        << FromTy << ToTy << (unsigned) isObjectArgument << I+1;
+        MaybeEmitInheritedConstructorNote(S, Fn);
+        return;
+      }
+  }
+  
   // TODO: specialize more based on the kind of mismatch
-
   // Emit the generic diagnostic and, optionally, add the hints to it.
   PartialDiagnostic FDiag = S.PDiag(diag::note_ovl_candidate_bad_conv);
   FDiag << (unsigned) FnKind << FnDesc

clang/test/SemaObjCXX/arc-overloading.mm

@@ -173,3 +173,22 @@ void test_f9() {
   const __autoreleasing id& ar3 = unsafe_unretained_a;
   const __autoreleasing id& ar4 = weak_a;
 }
+
+// rdar://9790531
+void f9790531(void *inClientData); // expected-note {{candidate function not viable: cannot implicitly convert argument of type 'MixerEQGraphTestDelegate *const __strong' to 'void *' for 1st argument under ARC}}
+void f9790531_1(struct S*inClientData); // expected-note {{candidate function not viable}}
+void f9790531_2(char * inClientData); // expected-note {{candidate function not viable}}
+
+@class UIApplication;
+
+@interface MixerEQGraphTestDelegate
+- (void)applicationDidFinishLaunching;
+@end
+
+@implementation MixerEQGraphTestDelegate
+- (void)applicationDidFinishLaunching {
+    f9790531(self); // expected-error {{no matching function for call to 'f9790531'}}
+    f9790531_1(self); // expected-error {{no matching function for call to 'f9790531_1'}}
+    f9790531_2(self); // expected-error {{no matching function for call to 'f9790531_2'}}
+}
+@end