[libcxx] r260570 - Work around regression in glibc 2.22: request that glibc provides the correct

[Richard Smith via cfe-commits]

This should be less broken in r260622. We no longer assume that glibc
provides non-broken declarations of the <string.h> functions. =(

On Thu, Feb 11, 2016 at 3:50 PM, Richard Smith <richard at metafoo.co.uk> wrote:
> The problem here is that your version of glibc has broken clang
> support -- see https://sourceware.org/ml/glibc-cvs/2014-q4/msg00215.html
>
> It looks like we may need Clang to start claiming to be GCC 4.4 or
> later to work around these glibc issues.
>
> On Thu, Feb 11, 2016 at 2:58 PM, Alexey Samsonov <vonosmas at gmail.com> wrote:
>> I see bogus boostrap build failures when we're trying to use just-built
>> Clang to build libc++:
>>
>> http://lab.llvm.org:8011/builders/sanitizer-x86_64-linux/builds/22540/steps/bootstrap%20clang/logs/stdio
>>
>> Do you think it can be related to one of your changes? I'm pretty sure the
>> contents of /usr/include/string.h wasn't changed for a while :)
>>
>> In file included from
>> /mnt/b/sanitizer-buildbot1/sanitizer-x86_64-linux/build/llvm/projects/libcxxabi/src/cxa_demangle.cpp:15:
>> In file included from
>> /mnt/b/sanitizer-buildbot1/sanitizer-x86_64-linux/build/llvm/projects/libcxx/include/vector:265:
>> In file included from
>> /mnt/b/sanitizer-buildbot1/sanitizer-x86_64-linux/build/llvm/projects/libcxx/include/__bit_reference:15:
>> In file included from
>> /mnt/b/sanitizer-buildbot1/sanitizer-x86_64-linux/build/llvm/projects/libcxx/include/algorithm:626:
>> In file included from
>> /mnt/b/sanitizer-buildbot1/sanitizer-x86_64-linux/build/llvm/projects/libcxx/include/cstring:61:
>> In file included from
>> /mnt/b/sanitizer-buildbot1/sanitizer-x86_64-linux/build/llvm/projects/libcxx/include/string.h:65:
>> /usr/include/string.h:81:1: error: unknown type name
>> '__extern_always_inline'
>> __extern_always_inline void *
>> ^
>> /usr/include/string.h:81:24: error: expected unqualified-id
>> __extern_always_inline void *
>>                        ^
>>
>> On Thu, Feb 11, 2016 at 11:40 AM, Richard Smith via cfe-commits
>> <cfe-commits at lists.llvm.org> wrote:
>>>
>>> Author: rsmith
>>> Date: Thu Feb 11 13:40:06 2016
>>> New Revision: 260570
>>>
>>> URL: http://llvm.org/viewvc/llvm-project?rev=260570&view=rev
>>> Log:
>>> Work around regression in glibc 2.22: request that glibc provides the
>>> correct
>>> prototypes for <string.h> functions that are converted into overload sets
>>> in
>>> C++. This matches the existing workaround in <wchar.h>.
>>>
>>> Modified:
>>>     libcxx/trunk/include/string.h
>>>
>>> Modified: libcxx/trunk/include/string.h
>>> URL:
>>> http://llvm.org/viewvc/llvm-project/libcxx/trunk/include/string.h?rev=260570&r1=260569&r2=260570&view=diff
>>>
>>> ==============================================================================
>>> --- libcxx/trunk/include/string.h (original)
>>> +++ libcxx/trunk/include/string.h Thu Feb 11 13:40:06 2016
>>> @@ -58,6 +58,10 @@ size_t strlen(const char* s);
>>>  #pragma GCC system_header
>>>  #endif
>>>
>>> +#ifdef __cplusplus
>>> +#define __CORRECT_ISO_CPP_STRING_H_PROTO
>>> +#endif
>>> +
>>>  #include_next <string.h>
>>>
>>>  // MSVCRT, GNU libc and its derivates already have the correct prototype
>>> in
>>>
>>>
>>> _______________________________________________
>>> cfe-commits mailing list
>>> cfe-commits at lists.llvm.org
>>> http://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
>>
>>
>>
>>
>> --
>> Alexey Samsonov
>> vonosmas at gmail.com