On 8/1/2013 5:46 PM, Brian Smith wrote:
FWIW, I talked about this issue with a group of ~10 Mozillians here in Berlin and all of them (AFAICT) were in favor of requiring that the latest versions of GCC be used, or even dropping GCC support completely in favor of clang, if it means that we can use more C++ language features and if it means we can avoid wasting time writing polyfills. Nobody saw installing a new version of GCC as part of the build environment as being a significant impediment.
And how many of them have actually tried to install new versions of gcc from scratch? As someone who works in compiler development, I can tell you firsthand that setting up working toolchains is an intricate dance of getting several tools to work together--the libc headers, the standard C++ library headers, debugger, linker, and compiler are all maintained by different projects, and a version mismatch between any two of these can foul up getting things to work that requires a lot of time and patience to fix even by people who know what they're doing. Look, for example, at some of the struggles we have had to go through to get Clang-on-Linux working on the buildbots.
Also, the limiting factor in using new C++ features right now is b2g, which builds with g++-4.4. If we fixed that, the minimum version per this policy would be g++-4.7. the limiting factor would either be STLport (which is much slower to adopt C++11 functionality than other libraries tied primarily to one compiler) or MSVC, which has yet to implement several C++11 features.
Instead of arguing right now about whether or not the minimum version policy suggested by glandium and I is too conservative, perhaps we should wait until someone proposes a feature whose need for polyfilling would depend on that policy comes up.
-- Joshua Cranmer Thunderbird and DXR developer Source code archæologist _______________________________________________ dev-platform mailing list dev-platform@lists.mozilla.org https://lists.mozilla.org/listinfo/dev-platform
