[C2hs] Syntax error with __restrict symbol in regex.h

[Duncan Coutts]

On Fri, 2006-04-28 at 20:26 -0400, Manuel M T Chakravarty wrote:
> Thanks for the report.  One more gcc extension we need to cover.

We do have some support for restrict/__restrict but it obviously didn't
cover this case. The restrict keyword is in C99 I believe so it's no
longer just a 'gcc'ism.

>From a quick glance over the grammar I couldn't obviously see why it
wasn't parsing this example.

Duncan

> Will Thompson:
> > Ahoy,
> > 
> > I am writing bindings for a library which includes regex.h from libc6
> > (version 2.6.3-3 in Debian). c2hs 0.14.5 refuses to parse regex.h as
> > follows:
> > 
> >     % c2hs Regex.chs
> >     c2hs: Error in C header file.
> > 
> >     /usr/include/regex.h:570: (column 125) [FATAL]
> >       >>> Syntax error!
> >       The symbol `restrict' does not fit here.
> > 
> > where Regex.chs contains:
> > 
> >     module Regex
> >     where
> >     #include <regex.h>
> > 
> > The offending section of regex.h is:
> > 
> >     /* GCC 2.95 and later have "__restrict"; C99 compilers have
> >        "restrict", and "configure" may have defined "restrict".  */
> >     #ifndef __restrict
> >     # if ! (2 < __GNUC__ || (2 == __GNUC__ && 95 <= __GNUC_MINOR__))
> >     #  if defined restrict || 199901L <= __STDC_VERSION__
> >     #   define __restrict restrict
> >     #  else
> >     #   define __restrict
> >     #  endif
> >     # endif
> >     #endif
> >     /* gcc 3.1 and up support the [restrict] syntax.  */
> >     #ifndef __restrict_arr
> >     # if __GNUC__ > 3 || (__GNUC__ == 3 && __GNUC_MINOR__ >= 1)
> >     #  define __restrict_arr __restrict
> >     # else
> >     #  define __restrict_arr
> >     # endif
> >     #endif
> > 
> >     /* POSIX compatibility.  */
> >     extern int regcomp _RE_ARGS ((regex_t *__restrict __preg,
> >                                   const char *__restrict __pattern,
> >                                   int __cflags));
> > 
> >     extern int regexec _RE_ARGS ((const regex_t *__restrict __preg,
> >                                   const char *__restrict __string, size_t __nmatch,
> >                                   regmatch_t __pmatch[__restrict_arr],
> >                                   int __eflags));
> > 
> > which, according to c2hs -k, is transformed by cpp on my system to:
> > 
> >     # 566 "/usr/include/regex.h" 3 4
> >     extern int regcomp (regex_t *__restrict __preg, const char *__restrict __pattern, int __cflags);
> > 
> > 
> > 
> >     extern int regexec (const regex_t *__restrict __preg, const char *__restrict __string, size_t __nmatch, regmatch_t __pmatch[__restrict], int __eflags);
> > 
> > `c2hs --cppopts="-D__restrict=" ...` works around the problem, so this
> > is irritating rather than a showstopper. I spoke to Duncan about this on
> > IRC yesterday: this is still present with 0.14.5:
> > 
> >     % c2hs --version
> >     C->Haskell Compiler, version 0.14.5 Travelling Lightly, 12 Dec 2005
> >       build platform is "i686-pc-linux-gnu" <1, True, True, 1>
> > 
> > If I can provide any more information, let me know.
> > 
> > Will
> > _______________________________________________
> > C2hs mailing list
> > C2hs at haskell.org
> > http://www.haskell.org/mailman/listinfo/c2hs
> 
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