Re: [RFC] sigsetjmp/siglongjmp on cygwin

[Andrew Cagney <ac131313 at cygnus dot com>]

Ben,

Since you know a thing or two about autoconf 
(http://sources.redhat.com/autobook/ ;-) would you mind giving an 
opinion on the below.

The full thread is at:

http://sources.redhat.com/ml/gdb-patches/2001-08/msg00012.html

	Andrew


> Hi,
> 
> I would like to discuss what to do about siglongjmp/sigsetjmp. These
> functions were recently added to configure.in:
> 
> 2001-07-12  Mark Kettenis  <kettenis@gnu.org>
> 
> * configure.in: Add check for sigsetjmp.
> 
> To make a long story short, I spent a lot of time trying to track this
> down. The crux of it is that sigsetjmp/siglongjmp _do_ exist on cygwin,
> but they are not reliable. I don't know why, but they are not.
> 
> Until the above change, cygwin used setjmp/longjmp, and this patch will
> force gdb to use them again.
> 
> I'm open to better ways of dealing with this.
> Keith
> 
> Possible ChangeLog
> 2001-08-01  Keith Seitz  <keiths@redhat.com>
> 
> * configure.in: Don't use sigsetjmp/siglongjmp on
> 	cygwin, even if it is available: it doesn't work.
> 	* configure: Regenerate.
> 
> Possible Patch
> Index: configure.in
> ===================================================================
> RCS file: /cvs/src/src/gdb/configure.in,v
> retrieving revision 1.66
> diff -u -p -r1.66 configure.in
> --- configure.in	2001/07/12 13:48:45	1.66
> +++ configure.in	2001/08/01 21:01:29
> @@ -137,11 +137,16 @@ AC_FUNC_ALLOCA
> 
>  # Check if sigsetjmp is available.  Using AC_CHECK_FUNCS won't do
>  # since sigsetjmp might only be defined as a macro.
> +# Cygwin has sigsetjmp/siglongjmp, but it doesn't seem to work...
>  AC_CACHE_CHECK([for sigsetjmp], gdb_cv_func_sigsetjmp,
>  [AC_TRY_COMPILE([
>  #include <setjmp.h>
> ], [sigjmp_buf env; while (! sigsetjmp (env, 1)) siglongjmp (env, 1);],
> -gdb_cv_func_sigsetjmp=yes, gdb_cv_func_sigsetjmp=no)])
> +[case "${host}" in
> +  *cygwin*) gdb_cv_func_sigsetjmp=no ;;
> +  *) gdb_cv_func_sigsetjmp=yes ;;
> +esac
> +], gdb_cv_func_sigsetjmp=no)])
>  if test $gdb_cv_func_sigsetjmp = yes; then
>    AC_DEFINE(HAVE_SIGSETJMP, 1, [Define if sigsetjmp is available. ])
>  fi
> 
> 
> 
>