GCC 4.5.0 Reports invalid warning

[Dave Korn]

On 16/07/2010 01:21, J Decker wrote:

> Now it's happy, why can't it just define 'struct a' as an appropriate
> name as it used to, the strucutre still isn't defined.

  That's just the way that C works, I'm afraid.

> (okay every other compiler I mention is MSVC, OpenWatcom, lcc, and gcc
> before now)

  Nah, gcc-4.3.4 also doesn't like it:

> $ gcc -c pa.c  -Wall -W
> pa.c:3: warning: 'struct a' declared inside parameter list
> pa.c:3: warning: its scope is only this definition or declaration, which is prob
> ably not what you want
> pa.c:8: error: conflicting types for 'f'
> pa.c:3: error: previous declaration of 'f' was here
> pa.c:8: warning: unused parameter 'a'

  Nor does gcc-3.4.4:

> $ gcc-3 -c pa.c  -Wall -W
> pa.c:3: warning: "struct a" declared inside parameter list
> pa.c:3: warning: its scope is only this definition or declaration, which is prob
> ably not what you want
> pa.c:8: warning: unused parameter 'a'

  Even MSVC more-or-less spots it, if you turn up the default warning level:

> $ cl /c /W4 pa.c
> Microsoft (R) 32-bit C/C++ Optimizing Compiler Version 12.00.8804 for 80x86
> Copyright (C) Microsoft Corp 1984-1998. All rights reserved.
> 
> pa.c
> pa.c(3) : warning C4115: 'a' : named type definition in parentheses
> pa.c(8) : warning C4100: 'a' : unreferenced formal parameter

    cheers,
      DaveK