[Bug bootstrap/46810] New: [4.6 regression] sparc64-linux bootstrap fails with "C++ preprocessor "/lib/cpp" fails sanity check"

[Bug bootstrap/46810] New: [4.6 regression] sparc64-linux bootstrap fails with "C++ preprocessor "/lib/cpp" fails sanity check"

[mikpe at it dot uu.se]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=46810

           Summary: [4.6 regression] sparc64-linux bootstrap fails with
                    "C++ preprocessor "/lib/cpp" fails sanity check"
           Product: gcc
           Version: 4.6.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: bootstrap
        AssignedTo: unassigned@gcc.gnu.org
        ReportedBy: mikpe@it.uu.se


Attempting to bootstrap 4.6-20101204 with C++ enabled on sparc64-linux fails
with:

checking how to run the C++ preprocessor... /lib/cpp
configure: error: in `/mnt/scratch/objdir46/gcc':
configure: error: C++ preprocessor "/lib/cpp" fails sanity check
See `config.log' for more details.
make[2]: *** [configure-stage1-gcc] Error 1
make[2]: Leaving directory `/mnt/scratch/objdir46'
make[1]: *** [stage1-bubble] Error 2
make[1]: Leaving directory `/mnt/scratch/objdir46'
make: *** [bootstrap] Error 2

gcc/config.log shows:

...
configure:8444: checking how to run the C++ preprocessor
configure:8471: g++ -E  conftest.cpp
/mnt/scratch/gcc-4.6-20101204/gcc/configure: line 2478: g++: command not found
...
configure:8471: g++ -E  conftest.cpp
/mnt/scratch/gcc-4.6-20101204/gcc/configure: line 2478: g++: command not found
...
configure:8471: /lib/cpp  conftest.cpp
cpp: error trying to exec 'cc1plus': execvp: No such file or directory
...

For the record, my bootstrap compiler only supports C and Ada, not C++.  (C++
should not require C++ for bootstrap, right?)

The previous weekly snapshot gcc-4.6-20101127 did not have this problem.

Configuration:
/mnt/scratch/gcc-4.6-20101204/configure --prefix=/mnt/scratch/install
--with-gmp=/home/mikpe/pkgs/linux-sparc64/gmp-4.3.2
--with-mpfr=/home/mikpe/pkgs/linux-sparc64/mpfr-2.4.2
--with-mpc=/home/mikpe/pkgs/linux-sparc64/mpc-0.8.2 --with-cpu=v8
--enable-multilib --disable-plugin --disable-lto --disable-nls
--enable-threads=posix --enable-checking=release --disable-libmudflap
--enable-languages=c,c++,objc,obj-c++,java,fortran

[Bug bootstrap/46810] [4.6 regression] sparc64-linux bootstrap fails with "C++ preprocessor "/lib/cpp" fails sanity check"

[rguenth at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=46810

Richard Guenther <rguenth at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
           Keywords|                            |build
   Target Milestone|---                         |4.6.0

--- Comment #1 from Richard Guenther <rguenth at gcc dot gnu.org> 2010-12-05 22:08:37 UTC ---
Correct.  A C++ host compiler is not required.

[Bug bootstrap/46810] [4.6 regression] sparc64-linux bootstrap fails with "C++ preprocessor "/lib/cpp" fails sanity check"

[jakub at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=46810

--- Comment #2 from Jakub Jelinek <jakub at gcc dot gnu.org> 2010-12-06 11:37:29 UTC ---
Created attachment 22652
  --> http://gcc.gnu.org/bugzilla/attachment.cgi?id=22652
gcc46-pr46810.patch

Wouldn't something like this fix this?  If neither --enable-build-with-cxx is
given, nor --enable-languages contains go, then we shouldn't require C++
compiler and in that case AC_LANG_PUSH(C++) is wrong.

[Bug bootstrap/46810] [4.6 regression] sparc64-linux bootstrap fails with "C++ preprocessor "/lib/cpp" fails sanity check"

[redi at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=46810

--- Comment #3 from Jonathan Wakely <redi at gcc dot gnu.org> 2010-12-06 11:59:26 UTC ---
would that also address PR 40950 ?

[Bug bootstrap/46810] [4.6 regression] sparc64-linux bootstrap fails with "C++ preprocessor "/lib/cpp" fails sanity check"

[pinskia at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=46810

--- Comment #4 from Andrew Pinski <pinskia at gcc dot gnu.org> 2010-12-06 18:11:49 UTC ---
(In reply to comment #2)
> Created attachment 22652 [details]
> gcc46-pr46810.patch
> 
> Wouldn't something like this fix this?  If neither --enable-build-with-cxx is
> given, nor --enable-languages contains go, then we shouldn't require C++
> compiler and in that case AC_LANG_PUSH(C++) is wrong.

Go should not require a C++ compiler for the first stage either ....

[Bug bootstrap/46810] [4.6 regression] sparc64-linux bootstrap fails with "C++ preprocessor "/lib/cpp" fails sanity check"

[ian at airs dot com]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=46810

Ian Lance Taylor <ian at airs dot com> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |ian at airs dot com

--- Comment #5 from Ian Lance Taylor <ian at airs dot com> 2010-12-06 20:12:27 UTC ---
I must say it's exceptionally lame that autoconf doesn't handle this correctly.
 It should just fail the tests if there is no C++ compiler.  I will see if
there is a simple way to make the configure script do that.

[Bug bootstrap/46810] [4.6 regression] sparc64-linux bootstrap fails with "C++ preprocessor "/lib/cpp" fails sanity check"

[ian at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=46810

--- Comment #6 from ian at gcc dot gnu.org <ian at gcc dot gnu.org> 2010-12-07 21:04:36 UTC ---
Author: ian
Date: Tue Dec  7 21:04:33 2010
New Revision: 167572

URL: http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=167572
Log:
    PR bootstrap/46810
    * configure.ac: Disable AC_MSG_ERROR while looking for the C++
    preprocessor.
    * configure: Rebuild.

Modified:
    trunk/gcc/ChangeLog
    trunk/gcc/configure
    trunk/gcc/configure.ac

[Bug bootstrap/46810] [4.6 regression] sparc64-linux bootstrap fails with "C++ preprocessor "/lib/cpp" fails sanity check"

[ian at airs dot com]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=46810

Ian Lance Taylor <ian at airs dot com> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |RESOLVED
         Resolution|                            |FIXED

--- Comment #7 from Ian Lance Taylor <ian at airs dot com> 2010-12-07 21:08:43 UTC ---
This should be fixed now.  Thanks for reporting it.

Note that we are considering shifting gcc to be built using C++ by default,
which will fail on your system until you install a C++ compiler (e.g., by
installing an earlier version of gcc).

This does not fix PR 40950, which must be fixed in some other way.