Commit Graph

19 Commits

Author SHA1 Message Date
Eric Fiselier e2f2d1edef [NFC] Rename _LIBCPP_TYPE_VIS_ONLY to _LIBCPP_TEMPLATE_VIS
The name _LIBCPP_TYPE_VIS_ONLY is no longer accurate because both
_LIBCPP_TYPE_VIS and _LIBCPP_TYPE_VIS_ONLY expand to
__attribute__((__type_visibility__)) with Clang. The only remaining difference
is that _LIBCPP_TYPE_VIS_ONLY can be applied to templates whereas
_LIBCPP_TYPE_VIS cannot (due to dllimport/dllexport not being allowed on
templates).

This patch renames _LIBCPP_TYPE_VIS_ONLY to _LIBCPP_TEMPLATE_VIS.

llvm-svn: 291035
2017-01-04 23:56:00 +00:00
Eric Fiselier f8f31c4985 [libc++] Add _LIBCPP_EXTERN_TEMPLATE_INLINE_VISIBILITY to support GCC ABI compatibility
Summary:
GCC and Clang handle visibility attributes on the out-of-line definition of externally instantiated templates differently. For example in the reproducer below Clang will emit both 'foo' and 'bar' with default visibility while GCC only emits a non-hidden 'foo'.  

```
// RUN: g++ -std=c++11 -shared -O3 test.cpp && sym_extract.py a.out
// RUN: clang++ -std=c++11 -shared -O3 test.cpp && sym_extract.py a.out
#define INLINE_VISIBILITY __attribute__((visibility("hidden"), always_inline))

template <class T>
struct Foo {
  void foo();
  void bar();
};

template <class T>
void Foo<T>::foo() {}

template <class T>
inline INLINE_VISIBILITY
void Foo<T>::bar() {}

template struct Foo<int>;
```

This difference creates ABI incompatibilities between Clang and GCC built dylibs. Specifically GCC built dylibs lack definitions for various member functions of `basic_string`, `basic_istream`, `basic_ostream`, `basic_iostream`, and `basic_streambuf` (All of these types are externally instantiated). 

Surprisingly these missing symbols don't cause many problems because the functions are marked `always_inline`  therefore the dylib definition is rarely needed. However when an out-of-line definition is required then GCC built dylibs will fail to link. For example [GCC built dylibs cannot build Clang](http://stackoverflow.com/questions/39454262/clang-build-errors).

This patch works around this issue by adding `_LIBCPP_EXTERN_TEMPLATE_INLINE_VISIBILITY` which is used to mark externally instantiated member functions as always inline. When building the library `_LIBCPP_EXTERN_TEMPLATE_INLINE_VISIBILITY` sets the symbol's visibility to "default" instead of "hidden", otherwise it acts exactly the same as `_LIBCPP_INLINE_VISIBILITY`.

After applying this patch GCC dylibs now contain:
  * `_ZNSt3__115basic_streambufIcNS_11char_traitsIcEEE7sungetcEv`
  * `_ZNSt3__115basic_streambufIwNS_11char_traitsIwEEE5gbumpEi`
  * `_ZNSt3__115basic_streambufIwNS_11char_traitsIwEEE7sungetcEv`
  * `_ZNSt3__115basic_streambufIcNS_11char_traitsIcEEE9sputbackcEc`
  * `_ZNSt3__113basic_istreamIwNS_11char_traitsIwEEE3getERNS_15basic_streambufIwS2_EE`
  * `_ZNSt3__113basic_ostreamIwNS_11char_traitsIwEEElsEPFRNS_9basic_iosIwS2_EES6_E`
  * `_ZNSt3__115basic_streambufIcNS_11char_traitsIcEEE4setpEPcS4_`
  * `_ZNSt3__113basic_ostreamIwNS_11char_traitsIwEEEC1EPNS_15basic_streambufIwS2_EE`
  * `_ZNSt3__115basic_streambufIcNS_11char_traitsIcEEE6snextcEv`
  * `_ZNSt3__113basic_istreamIcNS_11char_traitsIcEEE4swapERS3_`
  * `_ZNSt3__113basic_istreamIwNS_11char_traitsIwEEE4swapERS3_`
  * `_ZNSt3__112basic_stringIcNS_11char_traitsIcEENS_9allocatorIcEEE6__initEPKcm`
  * `_ZNSt3__113basic_istreamIcNS_11char_traitsIcEEErsEPFRNS_8ios_baseES5_E`
  * `_ZNSt3__115basic_streambufIcNS_11char_traitsIcEEE9pubsetbufEPcl`
  * `_ZNSt3__115basic_streambufIcNS_11char_traitsIcEEE10pubseekoffExNS_8ios_base7seekdirEj`
  * `_ZNSt3__113basic_istreamIwNS_11char_traitsIwEEErsEPFRNS_9basic_iosIwS2_EES6_E`
  * `_ZNSt3__115basic_streambufIwNS_11char_traitsIwEEE5pbumpEi`
  * `_ZNSt3__113basic_ostreamIcNS_11char_traitsIcEEE5seekpENS_4fposI11__mbstate_tEE`
  * `_ZNSt3__113basic_istreamIcNS_11char_traitsIcEEE7getlineEPcl`
  * `_ZNSt3__115basic_streambufIcNS_11char_traitsIcEEE5sgetcEv`
  * `_ZNSt3__113basic_istreamIcNS_11char_traitsIcEEE3getERNS_15basic_streambufIcS2_EE`
  * `_ZNSt3__113basic_ostreamIcNS_11char_traitsIcEEElsEPFRNS_8ios_baseES5_E`
  * `_ZNSt3__115basic_streambufIcNS_11char_traitsIcEEE8in_availEv`
  * `_ZNSt3__113basic_istreamIwNS_11char_traitsIwEEErsEPFRNS_8ios_baseES5_E`
  * `_ZNSt3__115basic_streambufIcNS_11char_traitsIcEEE6sbumpcEv`
  * `_ZNSt3__113basic_ostreamIcNS_11char_traitsIcEEElsEPFRNS_9basic_iosIcS2_EES6_E`
  * `_ZNSt3__113basic_istreamIcNS_11char_traitsIcEEE3getERc`
  * `_ZNSt3__115basic_streambufIwNS_11char_traitsIwEEE6snextcEv`
  * `_ZNSt3__112basic_stringIwNS_11char_traitsIwEENS_9allocatorIwEEE6__initEmw`
  * `_ZNSt3__113basic_istreamIwNS_11char_traitsIwEEE7getlineEPwl`
  * `_ZNSt3__113basic_ostreamIcNS_11char_traitsIcEEE5tellpEv`
  * `_ZNSt3__113basic_istreamIwNS_11char_traitsIwEEE3getERw`
  * `_ZNSt3__112basic_stringIcNS_11char_traitsIcEENS_9allocatorIcEEE6__initEmc`
  * `_ZNSt3__115basic_streambufIcNS_11char_traitsIcEEE7pubsyncEv`
  * `_ZNSt3__113basic_istreamIcNS_11char_traitsIcEEE3getEPcl`
  * `_ZNSt3__113basic_istreamIcNS_11char_traitsIcEEEC2EPNS_15basic_streambufIcS2_EE`
  * `_ZNSt3__113basic_istreamIcNS_11char_traitsIcEEErsEPFRNS_9basic_iosIcS2_EES6_E`
  * `_ZNSt3__115basic_streambufIwNS_11char_traitsIwEEE7pubsyncEv`
  * `_ZNSt3__115basic_streambufIcNS_11char_traitsIcEEE5sputcEc`
  * `_ZNSt3__113basic_ostreamIwNS_11char_traitsIwEEE5seekpExNS_8ios_base7seekdirE`
  * `_ZNKSt3__115basic_streambufIcNS_11char_traitsIcEEE6getlocEv`
  * `_ZNSt3__115basic_streambufIcNS_11char_traitsIcEEE5gbumpEi`
  * `_ZNSt3__114basic_iostreamIcNS_11char_traitsIcEEE4swapERS3_`
  * `_ZNSt3__113basic_ostreamIwNS_11char_traitsIwEEE5seekpENS_4fposI11__mbstate_tEE`
  * `_ZNSt3__113basic_ostreamIwNS_11char_traitsIwEEE5tellpEv`
  * `_ZNSt3__113basic_ostreamIwNS_11char_traitsIwEEElsEPFRS3_S4_E`
  * `_ZNSt3__113basic_istreamIwNS_11char_traitsIwEEE3getEPwl`
  * `_ZNSt3__113basic_istreamIwNS_11char_traitsIwEEEC2EPNS_15basic_streambufIwS2_EE`
  * `_ZNSt3__113basic_ostreamIcNS_11char_traitsIcEEElsEPFRS3_S4_E`
  * `_ZNSt3__115basic_streambufIcNS_11char_traitsIcEEE4setgEPcS4_S4_`
  * `_ZNSt3__112basic_stringIwNS_11char_traitsIwEENS_9allocatorIwEEE6__initEPKwmm`
  * `_ZNSt3__115basic_streambufIwNS_11char_traitsIwEEE4setgEPwS4_S4_`
  * `_ZNSt3__113basic_istreamIwNS_11char_traitsIwEEEC1EPNS_15basic_streambufIwS2_EE`
  * `_ZNSt3__115basic_streambufIcNS_11char_traitsIcEEE8pubimbueERKNS_6localeE`
  * `_ZNSt3__113basic_ostreamIcNS_11char_traitsIcEEE4swapERS3_`
  * `_ZNSt3__113basic_ostreamIwNS_11char_traitsIwEEEC2EPNS_15basic_streambufIwS2_EE`
  * `_ZNSt3__115basic_streambufIwNS_11char_traitsIwEEE10pubseekposENS_4fposI11__mbstate_tEEj`
  * `_ZNSt3__115basic_streambufIcNS_11char_traitsIcEEE5pbumpEi`
  * `_ZNSt3__115basic_streambufIwNS_11char_traitsIwEEE5sgetcEv`
  * `_ZNSt3__113basic_ostreamIwNS_11char_traitsIwEEE4swapERS3_`
  * `_ZNSt3__115basic_streambufIcNS_11char_traitsIcEEE10pubseekposENS_4fposI11__mbstate_tEEj`
  * `_ZNSt3__115basic_streambufIcNS_11char_traitsIcEEE5sputnEPKcl`
  * `_ZNSt3__113basic_ostreamIcNS_11char_traitsIcEEE5seekpExNS_8ios_base7seekdirE`
  * `_ZNSt3__115basic_streambufIwNS_11char_traitsIwEEE5sgetnEPwl`
  * `_ZNSt3__113basic_ostreamIwNS_11char_traitsIwEEElsEPFRNS_8ios_baseES5_E`
  * `_ZNSt3__115basic_streambufIwNS_11char_traitsIwEEE4setpEPwS4_`
  * `_ZNSt3__115basic_streambufIcNS_11char_traitsIcEEE5sgetnEPcl`
  * `_ZNKSt3__115basic_streambufIwNS_11char_traitsIwEEE6getlocEv`
  * `_ZNSt3__114basic_iostreamIcNS_11char_traitsIcEEEC2EPNS_15basic_streambufIcS2_EE`
  * `_ZNSt3__115basic_streambufIwNS_11char_traitsIwEEE8pubimbueERKNS_6localeE`
  * `_ZNSt3__114basic_iostreamIcNS_11char_traitsIcEEEC1EPNS_15basic_streambufIcS2_EE`
  * `_ZNSt3__115basic_streambufIwNS_11char_traitsIwEEE8in_availEv`
  * `_ZNSt3__113basic_istreamIcNS_11char_traitsIcEEEC1EPNS_15basic_streambufIcS2_EE`
  * `_ZNSt3__112basic_stringIcNS_11char_traitsIcEENS_9allocatorIcEEE6__initEPKcmm`
  * `_ZNSt3__115basic_streambufIwNS_11char_traitsIwEEE6sbumpcEv`
  * `_ZNSt3__115basic_streambufIwNS_11char_traitsIwEEE10pubseekoffExNS_8ios_base7seekdirEj`
  * `_ZNSt3__113basic_ostreamIcNS_11char_traitsIcEEEC2EPNS_15basic_streambufIcS2_EE`
  * `_ZNSt3__113basic_istreamIwNS_11char_traitsIwEEErsEPFRS3_S4_E`
  * `_ZNSt3__115basic_streambufIwNS_11char_traitsIwEEE9sputbackcEw`
  * `_ZNSt3__112basic_stringIwNS_11char_traitsIwEENS_9allocatorIwEEE6__initEPKwm`
  * `_ZNSt3__115basic_streambufIwNS_11char_traitsIwEEE5sputnEPKwl`
  * `_ZNSt3__113basic_istreamIcNS_11char_traitsIcEEErsEPFRS3_S4_E`
  * `_ZNSt3__113basic_ostreamIcNS_11char_traitsIcEEEC1EPNS_15basic_streambufIcS2_EE`
  * `_ZNSt3__115basic_streambufIwNS_11char_traitsIwEEE9pubsetbufEPwl`
  * `_ZNSt3__115basic_streambufIwNS_11char_traitsIwEEE5sputcEw`


This patch has no effect on Clang based builds.



Reviewers: mclow.lists, eugenis, danalbert, jroelofs, EricWF

Subscribers: beanz, cfe-commits, mgorny

Differential Revision: https://reviews.llvm.org/D24600

llvm-svn: 281681
2016-09-16 00:00:48 +00:00
Eric Fiselier 49e2967f27 [libc++] Fix and document visibility attributes for Clang, GCC and Windows.
Summary:
This patch fixes a number of problems with the visibility macros across GCC (on Unix) and Windows (DLL import/export semantics). All of the visibility macros are now documented under `DesignDocs/VisibilityMacros.rst`. Now I'll no longer forget the subtleties of each!

This patch adds two new visibility macros:

* `_LIBCPP_ENUM_VIS` for controlling the typeinfo of enum types. Only Clang supports this.
* `_LIBCPP_EXTERN_TEMPLATE_TYPE_VIS` for redefining visibility on explicit instantiation declarations. Clang and Windows require this.

After applying this patch GCC only emits one -Wattribute warning opposed to 30+.


Reviewers: mclow.lists, EricWF

Subscribers: beanz, mgorny, cfe-commits

Differential Revision: https://reviews.llvm.org/D24602

llvm-svn: 281673
2016-09-15 22:27:07 +00:00
Evandro Menezes 72d6a934cc [streambuf] Added call to traits_type::copy to common case in xsgetn()
Patch by Laman Sole <laxman.g@partner.samsung.com>, Sebastian Pop
<s.pop@samsung.com>, Aditya Kumar <aditya.k7@samsung.com>

Differential Revision: http://reviews.llvm.org/D21103

llvm-svn: 272401
2016-06-10 16:00:29 +00:00
Evgeniy Stepanov c86b392078 Revert "Remove visibility attributes from out-of-class method definitions in iostreams."
llvm-svn: 257193
2016-01-08 19:21:02 +00:00
Evgeniy Stepanov 26ba3870bf Remove visibility attributes from out-of-class method definitions in iostreams.
No point in pretending that these methods are hidden - they are
actually exported from libc++.so. Extern template declarations make
them part of libc++ ABI.

This patch does not change libc++.so export list (at least on Linux).

llvm-svn: 255177
2015-12-09 23:42:30 +00:00
Marshall Clow 09921a571f Make basic_streambuf::xsputn write characters in chunks whenever possible, instead of one at a time. References PR#10193
llvm-svn: 229866
2015-02-19 16:17:46 +00:00
Howard Hinnant f0544c2086 Nico Rieck: this patch series fixes visibility issues on Windows as explained in <http://lists.cs.uiuc.edu/pipermail/cfe-dev/2013-August/031214.html>.
llvm-svn: 188192
2013-08-12 18:38:34 +00:00
Howard Hinnant 6e41256f68 No functionality change at this time. I've split _LIBCPP_VISIBLE up into two flags: _LIBCPP_TYPE_VIS and _LIBCPP_FUNC_VIS. This is in preparation for taking advantage of clang's new __type_visibility__ attribute.
llvm-svn: 176593
2013-03-06 23:30:19 +00:00
Howard Hinnant cd47cbc7a4 Provide a way to disable use of extern templates in libc++. This is intended for the clients of libc++, not the libc++ build. The dylib should always contain the extern templates. To disable the client needs to put -D'_LIBCPP_EXTERN_TEMPLATE(...)=' on the command line.
llvm-svn: 167486
2012-11-06 21:08:48 +00:00
Howard Hinnant 6758190507 Use traits_type::to_int_type in basic_streambuf<_CharT, _Traits>::xsputn when calling overflow to correctly handle negative signed character types. This fixes http://llvm.org/bugs/show_bug.cgi?id=14074.
llvm-svn: 165884
2012-10-13 19:31:51 +00:00
Howard Hinnant c206366fd7 Quash a whole bunch of warnings
llvm-svn: 145624
2011-12-01 20:21:04 +00:00
Howard Hinnant 073458b1ab Windows support by Ruben Van Boxem.
llvm-svn: 142235
2011-10-17 20:05:10 +00:00
Howard Hinnant ce48a1137d _STD -> _VSTD to avoid macro clash on windows
llvm-svn: 134190
2011-06-30 21:18:19 +00:00
Howard Hinnant 412dbebe1b license change
llvm-svn: 119395
2010-11-16 22:09:02 +00:00
Howard Hinnant e060133553 visibility-decoration.
llvm-svn: 114671
2010-09-23 17:31:07 +00:00
Howard Hinnant b3371f6f49 Fixing whitespace problems
llvm-svn: 111750
2010-08-22 00:02:43 +00:00
Howard Hinnant 5b08a8a432 Wiped out some non-ascii characters that snuck into the copyright.
llvm-svn: 103516
2010-05-11 21:36:01 +00:00
Howard Hinnant 3e519524c1 libcxx initial import
llvm-svn: 103490
2010-05-11 19:42:16 +00:00