Re: [commit: ghc] master: define own version of PRIdPTR on platform where its not available (71f7ab6)

On Fri, Nov 9, 2012 at 10:20 AM, Karel Gardas <[email protected]> wrote:
> On 11/ 9/12 11:34 AM, Gabriel Dos Reis wrote:
>>>
>>> commit 71f7ab6a05448e48a3b5741bb8a5ef57701e9c70
>>> Author: Karel Gardas<[email protected]>
>>> Date:   Thu Nov 8 22:04:44 2012 +0100
>>>
>>>      define own version of PRIdPTR on platform where its not available
>>>
>>>      Note that PRIdPTR is considered as linux-ism so it's not available
>>> on platforms
>>>      like Solaris, although some other free Unix(-like) OSes apparently
>>> supports
>>>      it too.
>>
>>
>> The log comment is not correct.
>> In fact, it is ISO C99 standard; some old proprietary C system headers
>> not have it (13 years later) but it is not linux-ism.
>
>
> Hello,
>
> I've analyzed the issue and it looks like, Solaris is defining PRIdPTR in
> sys/int_fmtio.h, this file is thorough sys/inttypes.h included into
> inttypes.h when !defined(_XOPEN_SOURCE) || defined(_XPG6) ||
> defined(__EXTENSIONS__) -- unfortunately GHC's PosixSource.h which is
> included before inttypes.h in mkDerivedconstants.c defines _XOPEN_SOURCE for
> Solaris which means PRdPTR is not defined as the sys/int_fmtio.h is not
> included under such conditions.
>
> Now, I'm not expert in C nor in C99, but what does it mean? That Solaris is
> strict and does not consider _XOPEN_SOURCE to be C99?

yes.

>
> Small test:
>
> #define _XOPEN_SOURCE
>
> #include <stdio.h>
> #include <inttypes.h>
>
> int
> main()
> {
> printf("%s\n", PRIdPTR);
> return 0;
> }
>
> reveals that it cannot be compiled with gcc -std=c99 test.c due to following
> error:
> In file included from /usr/include/stdio.h:15:0,
>                  from test.c:3:
> /usr/include/sys/feature_tests.h:354:2: error: #error "Compiler or options
> invalid for pre-UNIX 03 X/Open applications  and pre-2001 POSIX
> applications"
> test.c: In function ‘main’:
> test.c:9:16: error: ‘PRIdPTR’ undeclared (first use in this function)
> test.c:9:16: note: each undeclared identifier is reported only once for each
> function it appears in
>
> and of course it cannot be compiled with simple gcc test.c due to:
>
> test.c: In function ‘main’:
> test.c:9:16: error: ‘PRIdPTR’ undeclared (first use in this function)
> test.c:9:16: note: each undeclared identifier is reported only once for each
> function it appears in
>
>
> When I remove _XOPEN_SOURCE definition, then the compilation with or without
> -std=c99 goes fine. To me it looks like _XOPEN_SOURCE is kind of in conflict
> with C99 -- at least on Solaris. The question is if Solaris team is right
> here or wrong here and how other platforms use/support this...
>
> But most important question is to undefine _XOPEN_SOURCE or define either
> _XPG6 or __EXTENSION__ just on Solaris? What's the most cleanest solution?
>
> Thanks for any idea!
> Karel

Include <inttypes.h> before all other standard headers.

-- Gaby