[Bug libstdc++/48811] New: error in compiling libstdc++ with -std=gnu++0x

[Bug libstdc++/48811] New: error in compiling libstdc++ with -std=gnu++0x

[vincenzo.innocente at cern dot ch]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=48811

           Summary: error in compiling libstdc++ with -std=gnu++0x
           Product: gcc
           Version: 4.6.1
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: libstdc++
        AssignedTo: unassigned@gcc.gnu.org
        ReportedBy: vincenzo.innocente@cern.ch


I tried to compile gcc with a subset of the  CXXFLAGS I use in my project
echo $CXXFLAGS 
-O2 -std=gnu++0x -ftree-vectorize -Wall -fvisibility-inlines-hidden
-fpermissive
I got this compilation error that may be worth fixing
libtool: compile: 
/home/data/newsoft/gcc-4.6-20110422/host-x86_64-unknown-linux-gnu/gcc/xgcc
-shared-libgcc
-B/home/data/newsoft/gcc-4.6-20110422/host-x86_64-unknown-linux-gnu/gcc
-nostdinc++
-L/home/data/newsoft/gcc-4.6-20110422/x86_64-unknown-linux-gnu/libstdc++-v3/src
-L/home/data/newsoft/gcc-4.6-20110422/x86_64-unknown-linux-gnu/libstdc++-v3/src/.libs
-B/usr/local/x86_64-unknown-linux-gnu/bin/
-B/usr/local/x86_64-unknown-linux-gnu/lib/ -isystem
/usr/local/x86_64-unknown-linux-gnu/include -isystem
/usr/local/x86_64-unknown-linux-gnu/sys-include
-I/home/data/newsoft/gcc-4.6-20110422/libstdc++-v3/../gcc
-I/home/data/newsoft/gcc-4.6-20110422/x86_64-unknown-linux-gnu/libstdc++-v3/include/x86_64-unknown-linux-gnu
-I/home/data/newsoft/gcc-4.6-20110422/x86_64-unknown-linux-gnu/libstdc++-v3/include
-I/home/data/newsoft/gcc-4.6-20110422/libstdc++-v3/libsupc++
-fno-implicit-templates -Wall -Wextra -Wwrite-strings -Wcast-qual
-fdiagnostics-show-location=once -ffunction-sections -fdata-sections -O2
-std=gnu++0x -ftree-vectorize -Wall -fvisibility-inlines-hidden -fpermissive
-D_GNU_SOURCE -c ../../.././libstdc++-v3/libsupc++/eh_ptr.cc  -fPIC -DPIC -o
eh_ptr.o
In file included from
/home/data/newsoft/gcc-4.6-20110422/libstdc++-v3/libsupc++/exception:154:0,
                 from ../../.././libstdc++-v3/libsupc++/eh_ptr.cc:31:
/home/data/newsoft/gcc-4.6-20110422/x86_64-unknown-linux-gnu/libstdc++-v3/include/bits/exception_ptr.h:128:16:
error: expected type-specifier before '__safe_bool'
../../.././libstdc++-v3/libsupc++/eh_ptr.cc:45:51: error: expected constructor,
destructor, or type conversion before '(' token
../../.././libstdc++-v3/libsupc++/eh_ptr.cc:125:47: error: expected
type-specifier before '__safe_bool'
make[4]: *** [eh_ptr.lo] Error 1

[Bug libstdc++/48811] error in compiling libstdc++ with -std=gnu++0x

[paolo.carlini at oracle dot com]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=48811

--- Comment #1 from Paolo Carlini <paolo.carlini at oracle dot com> 2011-04-28 19:51:56 UTC ---
Currently the library itself, its *.cc files, are not meant to be all built in
c++0x mode (the Makefile carefully builds some in c++03 mode and some in c++0x
mode). Thus, even if somehow one of these days it apparently works please do
*not* trust what you get, at minimum the abi compatibility could be broken.
Maybe that could change, but not soon, I'm sorry, the priority of the task is
quite low (compared to the other)

[Bug libstdc++/48811] error in compiling libstdc++ with -std=gnu++0x

[redi at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=48811

--- Comment #2 from Jonathan Wakely <redi at gcc dot gnu.org> 2011-04-30 19:24:45 UTC ---
Building like that is completely unsupported.  If anything is worth fixing here
it would be to strip any -std option from the library build flags, to ensure
the library is built as it's supposed to be built.

[Bug libstdc++/48811] error in compiling libstdc++ with -std=gnu++0x

[paolo.carlini at oracle dot com]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=48811

Paolo Carlini <paolo.carlini at oracle dot com> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |jwakely.gcc at gmail dot
                   |                            |com

--- Comment #3 from Paolo Carlini <paolo.carlini at oracle dot com> 2011-04-30 19:51:12 UTC ---
Good point Jon, we should do that, at least for the time being, to avoid
possible confusions (eg, people may in totally good faith believe that testing
the behavior of the c++0x front-end on the *.cc files either helps testing the
front-end or the correctness of the *.cc files themselves, without realizing
that the *.cc files and the Makefile are very carefully crafted to create a
shared and static library (suited for both C++03 and C++0x user-code builds)
without abi breakages).

Anyway, do you think it would be simple to implement that kind of 'stripping'?

[Bug libstdc++/48811] error in compiling libstdc++ with -std=gnu++0x

[redi at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=48811

--- Comment #4 from Jonathan Wakely <redi at gcc dot gnu.org> 2011-04-30 20:00:39 UTC ---
I don't know, but we also want to strip -pipe from the testsuite flags for PR
48565 so we need to figure out some way to do it :)

[Bug libstdc++/48811] error in compiling libstdc++ with -std=gnu++0x

[paolo.carlini at oracle dot com]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=48811

Paolo Carlini <paolo.carlini at oracle dot com> changed:

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

--- Comment #5 from Paolo Carlini <paolo.carlini at oracle dot com> 2011-04-30 23:20:45 UTC ---
Let's bother a bit Ralf, just in case he encountered already this kind of
issue...

[Bug libstdc++/48811] error in compiling libstdc++ with -std=gnu++0x

[paolo.carlini at oracle dot com]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=48811

Paolo Carlini <paolo.carlini at oracle dot com> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |RESOLVED
         Resolution|                            |FIXED
   Target Milestone|---                         |4.7.0

--- Comment #6 from Paolo Carlini <paolo.carlini at oracle dot com> 2011-05-23 15:48:46 UTC ---
Jason committed to mainline a tweak which avoids the compilation error. Note,
however, that building the whole set of *.cc files with -std=gnu++0x is still
unsupported and experimental, may work, may not work, you are on your own.