Wrong Objective-C diagnostic (incompatible pointer types)

[llvmbot]

Bugzilla Link	2707
Resolution	FIXED
Resolved on	Mar 12, 2010 00:57
Version	unspecified
OS	MacOS X
Attachments	test case
Reporter	LLVM Bugzilla Contributor
CC	@efriedma-quic,@tkremenek

Extended Description

Processing -fsyntax-only on the attached source code, I get the following wrong diagnostic:

---

thomas$ clang -fsyntax-only MyClass.m
MyClass.m:21:29: warning: incompatible pointer types sending 'CGColorRef', expected 'NSColor *'
[object setBackgroundColor:color];
^~~~~
1 diagnostic generated.

Clang seems to be confused by CGColorRef and NSColor *.
Using LLVM and Clang rev 55175.

Thomas

[efriedma-quic]

Likely my fault, but I can't reproduce on my computer. Could someone reduce a testcase that doesn't depend on Cocoa.h?

[tkremenek]

reduced test case

[tkremenek]

Likely my fault, but I can't reproduce on my computer. Could someone reduce a
testcase that doesn't depend on Cocoa.h?

The reduced test case I attached is self-contained (used delta-debugging to reduce cocoa.h)

[efriedma-quic]

Before I try to look at this further, a couple questions:

1. Should a declaration like the following affect diagnostics, even if it's never referenced?

@​class NSColor;
@​interface NSCell {}

• (void)setBackgroundColor:(NSColor *)color;
  @​end

2. Does clang currently have Sema support for @​property?

[efriedma-quic]

(My best guess is that this is a bug in the implementation of @​property... however, it's hard for me to check because I don't have a version of gcc that supports ObjC 2.0.)

[llvmbot]

I will take this one, it should be solved by work I am currently doing on properties.

In response to your questions Eli:

1. Should a declaration like the following affect diagnostics, even if it's
   never referenced?

@​class NSColor;
@​interface NSCell {}

• (void)setBackgroundColor:(NSColor *)color;
  @​end

Yes. Objective-C messages sends search the global scope of known method signatures when doing type resolution.

2. Does clang currently have Sema support for @​property?

No, it is incomplete, and that is the root problem (which I will fix soon hopefully).

• Daniel

[llvmbot]

This has been fixed (although I lost track of revision).