HUGE_VAL on Solaris (was: Re: On dropping -D_REENTRANT -D_THREAD_SAFE)

[Simon Josefsson]

Albert Chin <gnutls-dev at mlists.thewrittenword.com> writes:

> On Mon, Jan 07, 2008 at 10:12:13PM +0100, Simon Josefsson wrote:
>> Florian Weimer <fweimer at bfk.de> writes:
>> 
>> > * Simon Josefsson:
>> >
>> >> gcc -std=gnu99 -DHAVE_CONFIG_H -I. -I..  -I../includes -I../includes -I../lgl -I../lgl -I../gl -I../gl -I./cfg  -pipe -I/tmp/jas//include -g -O2 -MT shared.o -MD -MP -MF .deps/shared.Tpo -c -o shared.o `test -f 'cfg/shared.c' || echo './'`cfg/shared.c
>> >> cfg/shared.c: In function `store_single_arg':
>> >> cfg/shared.c:727: error: wrong type argument to unary plus
>> >> cfg/shared.c:727: error: wrong type argument to unary minus
>> >>
>> >> The line reads:
>> >>
>> >> 			if (double_val == +HUGE_VAL || double_val == -HUGE_VAL)
>> >
>> > Looks like a GCC bug to me.  I can't reproduce this with:
>> >
>> > gcc (GCC) 4.1.2 20061115 (prerelease) (Debian 4.1.1-21)
>> > gcc (GCC) 4.2.3 20071123 (prerelease) (Debian 4.2.2-4)
>> 
>> This was gcc 3.4.x and 4.0.3 on solaris 5.10, but on a machine that I
>> suspect doesn't have enough administrative TLC to have properly
>> installed tools.  So unless someone else reports the same issue, let's
>> ignore it.
>
> We see it with gcc-3.4.4 on Solaris 10/SPARC.

Indeed the problem seems real, however it seems to be a gcc bug:

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=19933

A patch for gcc back-ported to 3.4.x is:

http://gcc.gnu.org/ml/gcc-patches/2005-05/msg02123.html

I can't test the patch, but it seems to address the problem.

Does any of the suggested work-arounds work for you?  I.e., add the
following before the line containing "cfg+.h" in src/cfg/shared.c:

#define HUGE_VAL (__builtin_huge_val())

This work-around appears to work on the solaris 5.10 I have access to.

I'm not sure if we can detect this brokenness in a clean way, but
patches are welcome.  Otherwise, perhaps this message can serve as
sufficient documentation to work around this gcc problem.

/Simon