[cfe-dev] http://llvm.org/apt/ with 'old' gcc: Request for comments

[Sylvestre Ledru]

Hello,

Just a quick refresh, on llvm.org/apt/ [1], I am rebuilding the sources
of LLVM to create snapshot packages for the stable branches
and development branches (currently, 3.4, in the hope of point releases
and 3.5). This currently targets 2 releases of Debian and 4 of Ubuntu
[2] and the llvm
toolchain is built using the compiler shipped with the distribution.

Following the recent discussions on the usage of C+11, we have now/soon
a requirement on having a recent and C++11 compiler. [3]
That requires a recent version of gcc (for example, 4.6 is not working).
Unfortunately, more recent versions are not available in Debian wheezy
(current stable) or Ubuntu precise (an Ubuntu LTS).

The usage of a backported version of gcc is not really feasible because
it would trigger a dependency on libstdc++ 4.8 [4] and the installation
by the user
of the backported gcc.

For now, the obvious solution would be to drop the support of these
releases but there are still many users of these distributions.

Any suggestions? Static linkage of libstdc++? Usage of libc++? Usage of
clang 3.4 to bootstrap them?

Thanks,
Sylvestre

[1] http://llvm.org/apt/
[2] http://llvm-jenkins.debian.net/
[3] For example, currently, lldb fails to build with
/tmp/buildd/llvm-toolchain-snapshot-3.5~svn197872/tools/lldb/source/../include/lldb/Utility/Iterable.h:197:22:
sorry, unimplemented: non-static data member initializers
/tmp/buildd/llvm-toolchain-snapshot-3.5~svn197872/tools/lldb/source/../include/lldb/Utility/Iterable.h:197:22:
error: 'constexpr' needed for in-class initialization of static data
member 'm_mutex' of non-integral type
or fails to link with:
http://llvm.org/bugs/show_bug.cgi?id=18077
[4] http://llvm.org/bugs/show_bug.cgi?id=18272