[Bug bootstrap/46650] New: r167010 breaks --enable-build-with-cxx

[Bug bootstrap/46650] New: r167010 breaks --enable-build-with-cxx

[howarth at nitro dot med.uc.edu]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=46650

           Summary: r167010 breaks --enable-build-with-cxx
           Product: gcc
           Version: 4.6.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: bootstrap
        AssignedTo: unassigned@gcc.gnu.org
        ReportedBy: howarth@nitro.med.uc.edu


On x86_64-apple-darwin10 (and likely any target using an older g++), the
poisoning of strerror in system.h breaks the bootstrap when using
-enable-build-with-cxx. These failures are of the form...

g++ -c  -g -DIN_GCC   -W -Wall -Wwrite-strings -Wcast-qual
-Wmissing-format-attribute -pedantic -Wno-long-long -Wno-variadic-macros
-Wno-overlength-strings -fno-common  -DHAVE_CONFIG_H -I. -I.
-I../../gcc-4.6-20101124/gcc -I../../gcc-4.6-20101124/gcc/.
-I../../gcc-4.6-20101124/gcc/../include
-I../../gcc-4.6-20101124/gcc/../libcpp/include -I/sw/include -I/sw/include 
-I../../gcc-4.6-20101124/gcc/../libdecnumber
-I../../gcc-4.6-20101124/gcc/../libdecnumber/dpd -I../libdecnumber
-I/sw/include  -I/sw/include -DCLOOG_INT_GMP -DCLOOG_ORG -I/sw/include
../../gcc-4.6-20101124/gcc/c-lang.c -o c-lang.o
g++ -c  -g -DIN_GCC   -W -Wall -Wwrite-strings -Wcast-qual  -fno-common 
-DHAVE_CONFIG_H -I. -Ic-family -I../../gcc-4.6-20101124/gcc
-I../../gcc-4.6-20101124/gcc/c-family -I../../gcc-4.6-20101124/gcc/../include
-I../../gcc-4.6-20101124/gcc/../libcpp/include -I/sw/include -I/sw/include 
-I../../gcc-4.6-20101124/gcc/../libdecnumber
-I../../gcc-4.6-20101124/gcc/../libdecnumber/dpd -I../libdecnumber
-I/sw/include  -I/sw/include -DCLOOG_INT_GMP -DCLOOG_ORG -I/sw/include
../../gcc-4.6-20101124/gcc/c-family/stub-objc.c -o c-family/stub-objc.o
In file included from
/usr/include/c++/4.2.1/i686-apple-darwin10/x86_64/bits/c++locale.h:48,
                 from /usr/include/c++/4.2.1/iosfwd:45,
                 from /sw/include/gmp.h:24,
                 from ../../gcc-4.6-20101124/gcc/double-int.h:24,
                 from ../../gcc-4.6-20101124/gcc/tree.h:31,
                 from ../../gcc-4.6-20101124/gcc/c-family/stub-objc.c:26:
/usr/include/c++/4.2.1/cstring:75:8: error: attempt to use poisoned "strerror"
/usr/include/c++/4.2.1/cstring:95:11: error: attempt to use poisoned "strerror"

when using...

 ../gcc-4.6-20101124/configure --prefix=/sw --prefix=/sw/lib/gcc4.6
--mandir=/sw/share/man --infodir=/sw/lib/gcc4.6/info
--enable-languages=c,c++,fortran,objc,obj-c++,java --with-gmp=/sw
--with-libiconv-prefix=/sw --with-ppl=/sw --with-cloog=/sw --with-mpc=/sw
--with-system-zlib --x-includes=/usr/X11R6/include --x-libraries=/usr/X11R6/lib
--program-suffix=-fsf-4.6 --enable-checking=yes --enable-cloog-backend=isl
--enable-build-with-cxx

[Bug bootstrap/46650] r167010 breaks --enable-build-with-cxx

[howarth at nitro dot med.uc.edu]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=46650

--- Comment #1 from Jack Howarth <howarth at nitro dot med.uc.edu> 2010-11-25 01:41:33 UTC ---
The simplest fix for this issue would be to change the behavior of
--enable-build-with-cxx such that only stage2 and stage3 are built with the c++
compiler and stage 1 remains built with the c compiler.

[Bug bootstrap/46650] r167010 breaks --enable-build-with-cxx

[howarth at nitro dot med.uc.edu]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=46650

--- Comment #2 from Jack Howarth <howarth at nitro dot med.uc.edu> 2010-11-25 01:47:47 UTC ---
Note that Richard Guenther suggested the approach from Comment 1 in
http://gcc.gnu.org/ml/gcc-patches/2010-11/msg01605.html.

[Bug bootstrap/46650] r167010 breaks --enable-build-with-cxx

[joseph at codesourcery dot com]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=46650

--- Comment #3 from joseph at codesourcery dot com <joseph at codesourcery dot com> 2010-11-25 02:03:29 UTC ---
On Thu, 25 Nov 2010, howarth at nitro dot med.uc.edu wrote:

> In file included from
> /usr/include/c++/4.2.1/i686-apple-darwin10/x86_64/bits/c++locale.h:48,
>                  from /usr/include/c++/4.2.1/iosfwd:45,
>                  from /sw/include/gmp.h:24,
>                  from ../../gcc-4.6-20101124/gcc/double-int.h:24,
>                  from ../../gcc-4.6-20101124/gcc/tree.h:31,
>                  from ../../gcc-4.6-20101124/gcc/c-family/stub-objc.c:26:
> /usr/include/c++/4.2.1/cstring:75:8: error: attempt to use poisoned "strerror"
> /usr/include/c++/4.2.1/cstring:95:11: error: attempt to use poisoned "strerror"

Given that including gmp.h itself in system.h is probably a bad idea 
(might cause unwanted libgmp library dependencies for executables that 
otherwise don't need it), my inclination is to include just the problem 
<cstring> header from system.h.  That is:

#ifdef __cplusplus
#include <cstring>
#else
/* Existing code including <string.h> or <strings.h>.  */
#endif

I think it's reasonable for system.h to include C++ system headers when 
building as C++, and in general for it to use the C++ versions of C 
headers that have standard C++ versions (but hopefully it only needs to do 
so right now for <cstring>).

[Bug bootstrap/46650] r167010 breaks --enable-build-with-cxx

[howarth at nitro dot med.uc.edu]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=46650

--- Comment #4 from Jack Howarth <howarth at nitro dot med.uc.edu> 2010-11-25 04:12:47 UTC ---
Created attachment 22524
  --> http://gcc.gnu.org/bugzilla/attachment.cgi?id=22524
patch tested on x86_64-apple-darwin10

[Bug bootstrap/46650] r167010 breaks --enable-build-with-cxx

[howarth at nitro dot med.uc.edu]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=46650

--- Comment #5 from Jack Howarth <howarth at nitro dot med.uc.edu> 2010-11-26 17:28:08 UTC ---
Patch posted at http://gcc.gnu.org/ml/gcc-patches/2010-11/msg02567.html and
tested at http://gcc.gnu.org/ml/gcc-testresults/2010-11/msg02099.html.

[Bug bootstrap/46650] r167010 breaks --enable-build-with-cxx

[ian at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=46650

--- Comment #6 from ian at gcc dot gnu.org <ian at gcc dot gnu.org> 2010-12-13 18:34:48 UTC ---
Author: ian
Date: Mon Dec 13 18:34:45 2010
New Revision: 167764

URL: http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=167764
Log:
    PR bootstrap/46650
    * system.h: Include cstring for cxx bootstrap.

Modified:
    trunk/gcc/ChangeLog
    trunk/gcc/system.h

[Bug bootstrap/46650] r167010 breaks --enable-build-with-cxx

[howarth at nitro dot med.uc.edu]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=46650

Jack Howarth <howarth at nitro dot med.uc.edu> changed:

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

--- Comment #7 from Jack Howarth <howarth at nitro dot med.uc.edu> 2010-12-20 18:20:04 UTC ---
Fixed at r167764.