[Build, Patch, libquadmath] PR 46520 Do not call AC_CHECK_LIB for gcc_no_link

[Ralf Wildenhues]

Hi Tobias,

* Tobias Burnus wrote on Sat, Dec 18, 2010 at 11:17:16AM CET:
> The title says all. I am not sure whether this patch is sufficient
> but it is the next step to fix the build. (The symbol-versioning
> check might still fail on bare irons.)
> 
> OK for the trunk?

Is the usage of the two HAVE_* defines for optimization only?
Then the patch is OK.  But you might still consider adding a case
statement in the gcc_no_link branch seeding the correct defines
or the respective configure cache variables (ac_cv_lib_m_cbrtl etc)
for targets where the functions are known to be available.

For configure choices that are not just used for optimization,
of course that becomes required procedure.

Thanks,
Ralf

> 2010-12-18  Tobias Burnus  <burnus@net-b.de>
> 
> 	PR fortran/46520
> 	* configure.ac: Do not call AC_CHECK_LIB for gcc_no_link.
> 	* configure: Regenerate
> 
> diff --git a/libquadmath/configure.ac b/libquadmath/configure.ac
> index 56b1fcb..603d2c1 100644
> --- a/libquadmath/configure.ac
> +++ b/libquadmath/configure.ac
> @@ -109,8 +109,10 @@ esac
>  AC_SUBST(toolexecdir)
>  AC_SUBST(toolexeclibdir)
>  
> -AC_CHECK_LIB([m],[sqrtl],[AC_DEFINE([HAVE_SQRTL],[1],[libm includes sqrtl])])
> -AC_CHECK_LIB([m],[cbrtl],[AC_DEFINE([HAVE_CBRTL],[1],[libm includes cbrtl])])
> +if test x$gcc_no_link != xyes; then
> +  AC_CHECK_LIB([m],[sqrtl],[AC_DEFINE([HAVE_SQRTL],[1],[libm includes sqrtl])])
> +  AC_CHECK_LIB([m],[cbrtl],[AC_DEFINE([HAVE_CBRTL],[1],[libm includes cbrtl])])
> +fi
>  
>  # Check for symbol versioning (copied from libssp).
>  AC_MSG_CHECKING([whether symbol versioning is supported])