[Bug libfortran/55601] New: libgfortran build fails with --disable-libquadmath

[Bug libfortran/55601] New: libgfortran build fails with --disable-libquadmath

[danglin at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=55601

             Bug #: 55601
           Summary: libgfortran build fails with --disable-libquadmath
    Classification: Unclassified
           Product: gcc
           Version: 4.8.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: libfortran
        AssignedTo: unassigned@gcc.gnu.org
        ReportedBy: danglin@gcc.gnu.org
              Host: hppa2.0w-hp-hpux11.00
            Target: hppa2.0w-hp-hpux11.00
             Build: hppa2.0w-hp-hpux11.00


libtool: compile:  /xxx/gnu/gcc/objdir/./gcc/xgcc -B/xxx/gnu/gcc/objdir/./gcc/
-
B/opt/gnu/gcc/gcc-4.8/hppa2.0w-hp-hpux11.00/bin/
-B/opt/gnu/gcc/gcc-4.8/hppa2.0w
-hp-hpux11.00/lib/ -isystem /opt/gnu/gcc/gcc-4.8/hppa2.0w-hp-hpux11.00/include
-
isystem /opt/gnu/gcc/gcc-4.8/hppa2.0w-hp-hpux11.00/sys-include -DHAVE_CONFIG_H
-
I. -I../../../gcc/libgfortran -iquote../../../gcc/libgfortran/io
-I../../../gcc/
libgfortran/../gcc -I../../../gcc/libgfortran/../gcc/config -I../.././gcc
-I../.
./../gcc/libgfortran/../libgcc -I../libgcc -std=gnu99 -Wall -Wstrict-prototypes 
-Wmissing-prototypes -Wold-style-definition -Wextra -Wwrite-strings
-fcx-fortran
-rules -g -O2 -MT fmain.lo -MD -MP -MF .deps/fmain.Tpo -c
../../../gcc/libgfortr
an/fmain.c  -fPIC -DPIC -o .libs/fmain.o
In file included from ../../../gcc/libgfortran/fmain.c:4:0:
../../../gcc/libgfortran/libgfortran.h:61:29: fatal error: quadmath_weak.h: No
s
uch file or directory
 #  include "quadmath_weak.h"
                             ^
compilation terminated.

# ./xgcc -B./ -v
Reading specs from ./specs
COLLECT_GCC=./xgcc
COLLECT_LTO_WRAPPER=./lto-wrapper
Target: hppa2.0w-hp-hpux11.00
Configured with: ../gcc/configure --with-gnu-as --with-as=/opt/gnu/bin/as
--enable-shared --with-local-prefix=/opt/gnu --prefix=/opt/gnu/gcc/gcc-4.8
--with-gmp=/opt/gnu/gcc/gmp --enable-debug=no --disable-nls --disable-lto
--disable-libquadmath --enable-threads=posix
--enable-languages=c,c++,objc,fortran,ada,obj-c++
Thread model: posix
gcc version 4.8.0 20121202 (experimental) [trunk revision 194060] (GCC)

[Bug libfortran/55601] libgfortran build fails with --disable-libquadmath

[burnus at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=55601

Tobias Burnus <burnus at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |burnus at gcc dot gnu.org

--- Comment #1 from Tobias Burnus <burnus at gcc dot gnu.org> 2012-12-05 08:52:25 UTC ---
If you don't want libgfortran to use libquadmath, you should also disable the
READ(16) support in the frontend by configuring with:

  --disable-libquadmath-support


I think the proper solution for this PR is to add a libgfortran configure check
which fails with:

  "Cannot find libquadmath but the compiler has been compiled with REAL(16)
   support. Ensure that libquadmath is available or configure GCC with
   --disable-libquadmath-support"

[Bug libfortran/55601] libgfortran build fails with --disable-libquadmath

[pinskia at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=55601

Andrew Pinski <pinskia at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |NEW
   Last reconfirmed|                            |2012-12-09
     Ever Confirmed|0                           |1

[Bug libfortran/55601] libgfortran build fails with --disable-libquadmath

[burnus at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=55601

--- Comment #2 from Tobias Burnus <burnus at gcc dot gnu.org> 2012-12-10 08:41:36 UTC ---
Hmm, seemingly, the check ignores --disable-libquadmath-support by only testing
for C's __float support, cf. libgfortran/acinclude.m4's LIBGFOR_CHECK_FLOAT128.

gfortran itself is checked via libgfortran/acinclude.m4's
LIBGFOR_WORKING_GFORTRAN.

One probably should augment the C test by a Fortran "REAL(16)" test.
Additionally, one could directly honour --disable-libquadmath-support, which I
think is also passed to libgfortran's configure.


Regarding the --disable-libquadmath combined with --enable-libquadmath-support:
Some warning would be useful, but the question is how to trigger it.

[Bug libfortran/55601] libgfortran build fails with --disable-libquadmath

[brooks at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=55601

Brooks Moses <brooks at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |brooks at gcc dot gnu.org

--- Comment #3 from Brooks Moses <brooks at gcc dot gnu.org> ---
Why doesn't --disable-libquadmath imply --disable-libquadmath-support unless
it's explicitly enabled?  That really seems like the right thing here.