C++11 / Ubuntu 12.04

[OrpheeGT]

Hello,

I'm currently using Ubuntu 12.04 with GCC 4.6.4.

If I'm right, there is no support of C++11 with GCC 4.6.4

There is no GCC 4.8 on Ubuntu 12.04, only a PPA 4.8.1 with the following bug : https://gcc.gnu.org/bugzilla/show_bug.cgi?id=57899

So I tried to compile GCC 4.8.3 directly from sources... (I probably did something wrong...)

Default GCC :

/svn/git/libtorrent$ gcc -v
Using built-in specs.
COLLECT_GCC=gcc
COLLECT_LTO_WRAPPER=/usr/lib/gcc/x86_64-linux-gnu/4.6/lto-wrapper
Target: x86_64-linux-gnu
Configured with: ../src/configure -v --with-pkgversion='Ubuntu/Linaro 4.6.4-1ubuntu112.04' --with-bugurl=file:///usr/share/doc/gcc-4.6/README.Bugs --enable-languages=c,c++,fortran,objc,obj-c++ --prefix=/usr --program-suffix=-4.6 --enable-shared --enable-linker-build-id --with-system-zlib --libexecdir=/usr/lib --without-included-gettext --enable-threads=posix --with-gxx-include-dir=/usr/include/c++/4.6 --libdir=/usr/lib --enable-nls --with-sysroot=/ --enable-clocale=gnu --enable-libstdcxx-debug --enable-libstdcxx-time=yes --enable-gnu-unique-object --enable-plugin --enable-objc-gc --disable-werror --with-arch-32=i686 --with-tune=generic --enable-checking=release --build=x86_64-linux-gnu --host=x86_64-linux-gnu --target=x86_64-linux-gnu
Thread model: posix
gcc version 4.6.4 (Ubuntu/Linaro 4.6.4-1ubuntu1~12.04)

Default G++ :

/svn/git/libtorrent$ g++ -v
Using built-in specs.
COLLECT_GCC=g++
COLLECT_LTO_WRAPPER=/usr/lib/gcc/x86_64-linux-gnu/4.6/lto-wrapper
Target: x86_64-linux-gnu
Configured with: ../src/configure -v --with-pkgversion='Ubuntu/Linaro 4.6.4-1ubuntu112.04' --with-bugurl=file:///usr/share/doc/gcc-4.6/README.Bugs --enable-languages=c,c++,fortran,objc,obj-c++ --prefix=/usr --program-suffix=-4.6 --enable-shared --enable-linker-build-id --with-system-zlib --libexecdir=/usr/lib --without-included-gettext --enable-threads=posix --with-gxx-include-dir=/usr/include/c++/4.6 --libdir=/usr/lib --enable-nls --with-sysroot=/ --enable-clocale=gnu --enable-libstdcxx-debug --enable-libstdcxx-time=yes --enable-gnu-unique-object --enable-plugin --enable-objc-gc --disable-werror --with-arch-32=i686 --with-tune=generic --enable-checking=release --build=x86_64-linux-gnu --host=x86_64-linux-gnu --target=x86_64-linux-gnu
Thread model: posix
gcc version 4.6.4 (Ubuntu/Linaro 4.6.4-1ubuntu1~12.04)

I built 4.8.3 and installed it, and updated alternatives :

GCC 4.8.3 :
~/svn/git/libtorrent$ gcc -v
Utilisation des specs internes.
COLLECT_GCC=gcc
COLLECT_LTO_WRAPPER=/usr/lib/gcc/x86_64-linux-gnu/4.8.3/lto-wrapper
Target: x86_64-linux-gnu
Configuré avec: ../configure -v --enable-languages=c,c++,fortran,objc,obj-c++ --prefix=/usr --program-suffix=-4.8.3 --enable-shared --enable-linker-build-id --with-system-zlib --libexecdir=/usr/lib --without-included-gettext --enable-threads=posix --with-gxx-include-dir=/usr/include/c++/4.8.3 --libdir=/usr/lib --enable-nls --with-sysroot=/ --enable-clocale=gnu --enable-libstdcxx-debug --enable-libstdcxx-time=yes --enable-gnu-unique-object --enable-plugin --enable-objc-gc --disable-werror --with-arch-32=i686 --with-tune=generic --enable-checking=release --build=x86_64-linux-gnu --host=x86_64-linux-gnu --target=x86_64-linux-gnu --with-gmp=/usr/local/lib --with-mpc=/usr/lib --with-mpfr=/usr/lib --disable-checking
Modèle de thread: posix
gcc version 4.8.3 (GCC)

G++ 4.8.3 :

:~/svn/git/libtorrent$ g++ -v
Utilisation des specs internes.
COLLECT_GCC=g++
COLLECT_LTO_WRAPPER=/usr/lib/gcc/x86_64-linux-gnu/4.8.3/lto-wrapper
Target: x86_64-linux-gnu
Configuré avec: ../configure -v --enable-languages=c,c++,fortran,objc,obj-c++ --prefix=/usr --program-suffix=-4.8.3 --enable-shared --enable-linker-build-id --with-system-zlib --libexecdir=/usr/lib --without-included-gettext --enable-threads=posix --with-gxx-include-dir=/usr/include/c++/4.8.3 --libdir=/usr/lib --enable-nls --with-sysroot=/ --enable-clocale=gnu --enable-libstdcxx-debug --enable-libstdcxx-time=yes --enable-gnu-unique-object --enable-plugin --enable-objc-gc --disable-werror --with-arch-32=i686 --with-tune=generic --enable-checking=release --build=x86_64-linux-gnu --host=x86_64-linux-gnu --target=x86_64-linux-gnu --with-gmp=/usr/local/lib --with-mpc=/usr/lib --with-mpfr=/usr/lib --disable-checking
Modèle de thread: posix
gcc version 4.8.3 (GCC)

But when I try to build libtorrent/rtorrent I always have the following error :
checking C++11 support... configure: error: No support for C++11 found.

I found on google how to check C++11 :

g++ -E -dM -std=c++11 -x c++ /dev/null >b

with GCC 4.6.4 :
$ g++ -E -dM -std=c++11 -x c++ /dev/null >b
cc1plus: error: unrecognized command line option ‘-std=c++11’

With GCC 4.8.3 :
$ g++ -E -dM -std=c++11 -x c++ /dev/null >b
$
(no error)

Could you help me ?

Thank you

[rakshasa]

Not with gcc compiler errors.

However the language/library features I intend to use for master branch in late C++0x found in GCC an CLang releases the past few years.

So 4.6 should be ok, and I'll add an option to enable c++0x and add tests as needed.

[OrpheeGT]

Ok thank you, I'll follow the commits :)

[rakshasa]

The "--enable-c++0x" option has been committed.

[OrpheeGT]

Thank you, tried it and it works great.

I had to update 3 parameters in my rtorrent.rc

use_udp_trackers
peer_exchange
system.method.set_key

(found the new params in .sed file)

Thank you for all :)