On Mon, May 5, 2014 at 10:47 AM, Chandler Carruth <chandlerc at google.com>wrote:> On Mon, May 5, 2014 at 8:11 AM, Alp Toker <alp at nuanti.com> wrote: > >> I suspect that pulling in clang header fixes r201729, r202911 and r207606 >> to 3.4.1 will resolve libstdc++ / glibc compatibility issues people have >> been having with 3.4: >> >> r201729: Teach Clang to provide ::max_align_t in C11 and C++11 modes) >> r202911: Headers: Provide an ABI compatible max_align_t when _MSC_VER >> is defined) >> r207606: Let stddef.h respect __need_{wchar_t, size_t, NULL, ptrdiff_t, >> wint_t}. >> >> The changes look safe to merge but I'd like to hear a second opinion from >> Chandler or Nico. >> > > I believe all of these are very safe, but I respect Tom's position here. > As he is managing the release, he gets to say "not in this one". If you > want someone to approve merging these three patches into any release, > Richard Smith is the person to ask IMO. >The first two are approved for the branch if Tom wants to take them (and they seem like good fixes to have). Tom: if you take r201729, you will need to also take the corresponding libc++ change, r201843. r207606 hasn't had much time to bake, and fixes a problem that is not a regression, so I'd be hesitant to approve it for 3.4.1. -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://lists.llvm.org/pipermail/llvm-dev/attachments/20140505/7e456011/attachment.html>
On 05/05/2014 20:51, Richard Smith wrote:> On Mon, May 5, 2014 at 10:47 AM, Chandler Carruth > <chandlerc at google.com <mailto:chandlerc at google.com>> wrote: > > On Mon, May 5, 2014 at 8:11 AM, Alp Toker <alp at nuanti.com > <mailto:alp at nuanti.com>> wrote: > > I suspect that pulling in clang header fixes r201729, r202911 > and r207606 to 3.4.1 will resolve libstdc++ / glibc > compatibility issues people have been having with 3.4: > > r201729: Teach Clang to provide ::max_align_t in C11 and > C++11 modes) > r202911: Headers: Provide an ABI compatible max_align_t when > _MSC_VER is defined) > r207606: Let stddef.h respect __need_{wchar_t, size_t, NULL, > ptrdiff_t, wint_t}. > > The changes look safe to merge but I'd like to hear a second > opinion from Chandler or Nico. > > > I believe all of these are very safe, but I respect Tom's position > here. As he is managing the release, he gets to say "not in this > one". If you want someone to approve merging these three patches > into any release, Richard Smith is the person to ask IMO. > > > The first two are approved for the branch if Tom wants to take them > (and they seem like good fixes to have). > > Tom: if you take r201729, you will need to also take the corresponding > libc++ change, r201843. > > r207606 hasn't had much time to bake, and fixes a problem that is not > a regression, so I'd be hesitant to approve it for 3.4.1.Thanks for pointing that out Richard. r201729 + r201843 sounds good. I'm concerned that advice has already appeared online instructing users to patch their libstdc++ system headers in order to install clang 3.4 on Linux. If we don't get the right fix out, distributors will find their own way to ship 3.4.1 to the detriment of our users and against our own interests. https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=744792 - clang-3.4: unusable with libstdc++ from gcc 4.9 https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=744872 - once gcc-4.9 and g++-4.9 are installed, clang stops properly building existing projects https://bugzilla.redhat.com/show_bug.cgi?id=1092622 - clang-3.4: unusable with libstdc++ from gcc 4.9 Alp. -- http://www.nuanti.com the browser experts
On Mon, May 05, 2014 at 11:42:28PM +0100, Alp Toker wrote:> > On 05/05/2014 20:51, Richard Smith wrote: > > On Mon, May 5, 2014 at 10:47 AM, Chandler Carruth > > <chandlerc at google.com <mailto:chandlerc at google.com>> wrote: > > > > On Mon, May 5, 2014 at 8:11 AM, Alp Toker <alp at nuanti.com > > <mailto:alp at nuanti.com>> wrote: > > > > I suspect that pulling in clang header fixes r201729, r202911 > > and r207606 to 3.4.1 will resolve libstdc++ / glibc > > compatibility issues people have been having with 3.4: > > > > r201729: Teach Clang to provide ::max_align_t in C11 and > > C++11 modes) > > r202911: Headers: Provide an ABI compatible max_align_t when > > _MSC_VER is defined) > > r207606: Let stddef.h respect __need_{wchar_t, size_t, NULL, > > ptrdiff_t, wint_t}. > > > > The changes look safe to merge but I'd like to hear a second > > opinion from Chandler or Nico. > > > > > > I believe all of these are very safe, but I respect Tom's position > > here. As he is managing the release, he gets to say "not in this > > one". If you want someone to approve merging these three patches > > into any release, Richard Smith is the person to ask IMO. > > > > > > The first two are approved for the branch if Tom wants to take them > > (and they seem like good fixes to have). > > > > Tom: if you take r201729, you will need to also take the corresponding > > libc++ change, r201843. > > > > r207606 hasn't had much time to bake, and fixes a problem that is not > > a regression, so I'd be hesitant to approve it for 3.4.1. > > Thanks for pointing that out Richard. r201729 + r201843 sounds good. > > I'm concerned that advice has already appeared online instructing users > to patch their libstdc++ system headers in order to install clang 3.4 on > Linux. If we don't get the right fix out, distributors will find their > own way to ship 3.4.1 to the detriment of our users and against our own > interests. >We can work with distros to make sure they apply the correct fix until we can get them into a release. It's just too late for these to go into 3.4.1. The code has already been validated and is ready to be released. However, I have no problem with doing a 3.4.2 release with these patches. Pushing these off to the next release will also give us a chance to fully test LLVM 3.4 with gcc 4.9, so we will be able to include other fixes as necessary. -Tom> https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=744792 - clang-3.4: > unusable with libstdc++ from gcc 4.9 > https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=744872 - once > gcc-4.9 and g++-4.9 are installed, clang stops properly building > existing projects > https://bugzilla.redhat.com/show_bug.cgi?id=1092622 - clang-3.4: > unusable with libstdc++ from gcc 4.9 > > Alp. > > -- > http://www.nuanti.com > the browser experts >