On Fri, Oct 7, 2011 at 3:20 PM, Douglas Gregor <[email protected]> wrote: > > On Oct 5, 2011, at 2:52 PM, Francois Pichet wrote: > >> On Wed, Oct 5, 2011 at 1:58 PM, Bob Wilson <[email protected]> wrote: >>> Francois, >>> >>> I just noticed this change: >>> >>> r140009 | fpichet | 2011-09-18 22:15:54 -0700 (Sun, 18 Sep 2011) | 1 line >>> >>> Do not use builtin includes if -fms-compatibility is specified. Some MSVC >>> header files have the same name as clang's builtins, this creates clash. >>> >>> Are you sure this is the right thing to do? If none of the clang-specific >>> header files are available, that means that things like the AVX/SSE >>> intrinsics will not be available. What about clang's version of tgmath.h? >>> Etc. What MSVC header files caused a clash and what was the problem with >>> that clash? >>> >> The problem is: >> using clang compiled with MSVC 2010 >> given test.cpp: >> #include <vector> >> >> C:\dev\llvm\test>clang test5.cpp >> In file included from test5.cpp:1: >> In file included from C:\Program Files (x86)\Microsoft Visual Studio >> 10.0\VC\inc >> lude\vector:6: >> In file included from C:\Program Files (x86)\Microsoft Visual Studio >> 10.0\VC\inc >> lude\memory:987: >> In file included from C:\Program Files (x86)\Microsoft Visual Studio >> 10.0\VC\inc >> lude\intrin.h:26: >> C:\Program Files (x86)\Microsoft Visual Studio >> 10.0\VC\include\ammintrin.h:222:1 >> : error: >> unknown type name '__m256' >> __m256 _mm256_macc_ps(__m256, __m256, __m256); >> ^ >> a flooding of errors >> >> That is because ammintrin.h includes some headers existing on MSVC and >> clang include's builtins directory. When compiling MSVC headers you >> really want clang to pick the MSVC headers otherwise it won't work. > > We typically want to use Clang's definitions because we can make sure that > work well with Clang. If it's just additional definitions you're missing, > they could either be added to Clang or you could use the #include_next > mechanism. >
I don't understand why you would want to use clang definition instead of the MSVC one when -fms-compatibility is on. They are not necessary equivalent. My idea of -fms-compatibility is for clang.exe to see exactly the same stream of tokens as cl.exe would see when compiling MSVC code on Windows. _______________________________________________ cfe-commits mailing list [email protected] http://lists.cs.uiuc.edu/mailman/listinfo/cfe-commits
