Re: 24.0.50; gnulib defines intmax_t to int64_t on OSX, causes warnings and confusion.

[Jan Djärv]

Paul Eggert skrev 2011-07-09 12.01:
> [Following up<http://debbugs.gnu.org/cgi/bugreport.cgi?bug=9025>
> and cc'ing to bug-gnulib:]
>
> Jan Djärv writes:
>
> > Somewhere in gnulib, intmax_t gets defined to int64_t thus causing
> > compiler warnings and general confusion (the code says intmax_t but is
> > really int64_t).  AFAIK, all versions of OSX have intmax_t.
>
> Thanks for reporting this.  I assume that intmax_t is 'long long'
> whereas int64_t is 'long'?  If not, what are those two types defined
> to in the system? and by gnulib?

/usr/include/stdint.h:

typedef long long            int64_t;

and

#ifndef _INTMAX_T
#define _INTMAX_T
#ifdef __INTMAX_TYPE__
typedef __INTMAX_TYPE__             intmax_t;
#else /* __INTMAX_TYPE__ */
typedef long long                intmax_t;
#endif /* __INTMAX_TYPE__ */
#endif /* _INTMAX_T */

I don't know where __INTMAX_TYPE__ is defined, but looking at preprocessed 
output gives:

typedef long int intmax_t;


> Which compiler and OS version are you using?

% gcc -v
Using built-in specs.
Target: i686-apple-darwin10
Configured with: /var/tmp/gcc/gcc-5664~89/src/configure --disable-checking 
--enable-werror --prefix=/usr --mandir=/share/man 
--enable-languages=c,objc,c++,obj-c++ 
--program-transform-name=/^[cg][^.-]*$/s/$/-4.2/ --with-slibdir=/usr/lib 
--build=i686-apple-darwin10 --program-prefix=i686-apple-darwin10- 
--host=x86_64-apple-darwin10 --target=i686-apple-darwin10 
--with-gxx-include-dir=/include/c++/4.2.1
Thread model: posix
gcc version 4.2.1 (Apple Inc. build 5664)

OSX 10.6.8.


> Does the following (untested) patch to lib/stdint.in.h fix your problem?

Yes it does.

        Jan D.

> diff --git a/lib/stdint.in.h b/lib/stdint.in.h
> index c44401f..0dd60b9 100644
> --- a/lib/stdint.in.h
> +++ b/lib/stdint.in.h
> @@ -270,6 +270,11 @@ typedef unsigned long int gl_uintptr_t;
>   /* Note: These types are compiler dependent. It may be unwise to use them in
>      public header files. */
>
> +/* If the system defines INTMAX_MAX, assume that intmax_t works, and
> +   similarly for UINTMAX_MAX and uintmax_t.  This avoids problems with
> +   assuming one type where another is used by the system.  */
> +
> +#ifndef INTMAX_MAX
>   #undef intmax_t
>   #if @HAVE_LONG_LONG_INT@&&  LONG_MAX>>  30 == 1
>   typedef long long int gl_intmax_t;
> @@ -280,7 +285,9 @@ typedef long long int gl_intmax_t;
>   typedef long int gl_intmax_t;
>   # define intmax_t gl_intmax_t
>   #endif
> +#endif
>
> +#ifndef UINTMAX_MAX
>   #undef uintmax_t
>   #if @HAVE_UNSIGNED_LONG_LONG_INT@&&  ULONG_MAX>>  31 == 1
>   typedef unsigned long long int gl_uintmax_t;
> @@ -291,6 +298,7 @@ typedef unsigned long long int gl_uintmax_t;
>   typedef unsigned long int gl_uintmax_t;
>   # define uintmax_t gl_uintmax_t
>   #endif
> +#endif
>
>   /* Verify that intmax_t and uintmax_t have the same size.  Too much code
>      breaks if this is not the case.  If this check fails, the reason is likely
> @@ -431,8 +439,8 @@ typedef int _verify_intmax_size[sizeof (intmax_t) == sizeof 
> (uintmax_t)
>
>   /* 7.18.2.5. Limits of greatest-width integer types */
>
> +#ifndef INTMAX_MAX
>   #undef INTMAX_MIN
> -#undef INTMAX_MAX
>   #ifdef INT64_MAX
>   # define INTMAX_MIN  INT64_MIN
>   # define INTMAX_MAX  INT64_MAX
> @@ -440,13 +448,15 @@ typedef int _verify_intmax_size[sizeof (intmax_t) == 
> sizeof (uintmax_t)
>   # define INTMAX_MIN  INT32_MIN
>   # define INTMAX_MAX  INT32_MAX
>   #endif
> +#endif
>
> -#undef UINTMAX_MAX
> +#ifndef UINTMAX_MAX
>   #ifdef UINT64_MAX
>   # define UINTMAX_MAX  UINT64_MAX
>   #else
>   # define UINTMAX_MAX  UINT32_MAX
>   #endif
> +#endif
>
>   /* 7.18.3. Limits of other integer types */