When suggesting a typo correction for an @implementation without a

corresponding @interface, provide a note showing which interface we're
referring to. This note has the fix-it hint on it.

Also, don't automatically apply fix-it hints for notes. They're meant
to express fix-its that would change semantics.

llvm-svn: 92870

clang/lib/Frontend/FixItRewriter.cpp

@@ -115,6 +115,9 @@ void FixItRewriter::HandleDiagnostic(Diagnostic::Level DiagLevel,
 
     if (!AcceptableLocation)
       return;
+  } else if (DiagLevel == Diagnostic::Note) {
+    // Don't apply fix-it modifications in notes.
+    return;
   }
 
   // Make sure that we can perform all of the modifications we

clang/lib/Sema/SemaDeclObjC.cpp

@@ -701,11 +701,17 @@ Sema::DeclPtrTy Sema::ActOnStartClassImplementation(
     LookupResult R(*this, ClassName, ClassLoc, LookupOrdinaryName);
     if (CorrectTypo(R, TUScope, 0) &&
         (IDecl = R.getAsSingle<ObjCInterfaceDecl>())) {
-      // Suggest the (potentially) correct interface name. However, don't
+      // Suggest the (potentially) correct interface name. However, put the
+      // fix-it hint itself in a separate note, since changing the name in 
+      // the warning would make the fix-it change semantics.However, don't
       // provide a code-modification hint or use the typo name for recovery,
       // because this is just a warning. The program may actually be correct.
       Diag(ClassLoc, diag::warn_undef_interface_suggest)
         << ClassName << R.getLookupName();
+      Diag(IDecl->getLocation(), diag::note_previous_decl)
+        << R.getLookupName()
+        << CodeModificationHint::CreateReplacement(ClassLoc,
+                                               R.getLookupName().getAsString());
       IDecl = 0;
     } else {
       Diag(ClassLoc, diag::warn_undef_interface) << ClassName;

clang/test/SemaObjC/undef-superclass-1.m

@@ -13,7 +13,8 @@
 @interface INTF2 : INTF1
 @end
 
-@interface INTF3 : Y // expected-error {{cannot find interface declaration for 'Y', superclass of 'INTF3'}}
+@interface INTF3 : Y // expected-error {{cannot find interface declaration for 'Y', superclass of 'INTF3'}} \
+                     // expected-note{{'INTF3' declared here}}
 @end
 
 @interface INTF1  // expected-error {{duplicate interface definition for class 'INTF1'}}