Commit Graph

233 Commits

Author SHA1 Message Date
Eric Fiselier
8c57032b52 Remove _LIBCPP_HAS_NO_DEFAULTED_FUNCTIONS
libc++ no longer supports C++11 compilers that don't implement `= default`.
This patch removes all instances of the feature test macro
_LIBCPP_HAS_NO_DEFAULTED_FUNCTIONS as well as the potentially dead code it hides.


git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@287321 91177308-0d34-0410-b5e6-96231b3b80d8
2016-11-18 06:42:17 +00:00
Eric Fiselier
a93ebeca94 Workaround compilers w/o C++1z inline variables
git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@287255 91177308-0d34-0410-b5e6-96231b3b80d8
2016-11-17 20:08:43 +00:00
Shoaib Meenai
e6479bc783 [libc++] Introduce _LIBCPP_OVERRIDABLE_FUNC_VIS
This is a generalization of `_LIBCPP_NEW_DELETE_VIS`; the new macro name
captures the semantics better, and also allows us to get rid of the
`_WIN32` check in `include/new`. No functional change.

Differential Revision: https://reviews.llvm.org/D26702

git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@287164 91177308-0d34-0410-b5e6-96231b3b80d8
2016-11-16 22:18:10 +00:00
Shoaib Meenai
3b2cf9659d [libc++] Add configuration define for off_t functions
Create this define in __config and use it elsewhere, instead of checking
the operating system/library defines in other files. The aim is to
reduce the usage of _WIN32 outside __config. No functional change.

Differential Revision: https://reviews.llvm.org/D25741

git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@285582 91177308-0d34-0410-b5e6-96231b3b80d8
2016-10-31 15:09:10 +00:00
Eric Fiselier
eb6b13f578 Fix _LIBCPP_EXTERN_TEMPLATE_INLINE_VISIBILITY to always have default visibility.
This prevent the symbols from being both externally available and hidden, which
causes them to be linked incorrectly. This is only a problem when the address
of the function is explicitly taken since it will always be inlined otherwise.

This patch fixes the issues that caused r285456 to be reverted, and can
now be reapplied.


git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@285531 91177308-0d34-0410-b5e6-96231b3b80d8
2016-10-31 02:07:23 +00:00
Eric Fiselier
2017e23c4a Revert addition of __libcpp_library_version
git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@285466 91177308-0d34-0410-b5e6-96231b3b80d8
2016-10-28 22:37:24 +00:00
Eric Fiselier
b18d684964 Try 2 to add extern C++ to __libcpp_library_version
git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@285427 91177308-0d34-0410-b5e6-96231b3b80d8
2016-10-28 18:26:06 +00:00
Eric Fiselier
3dd46201c1 Explicitly specify extern "C++" on __libcpp_library_version
git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@285403 91177308-0d34-0410-b5e6-96231b3b80d8
2016-10-28 15:02:30 +00:00
Eric Fiselier
6994470189 Add __libcpp_version file and __libcpp_library_version function.
This patch does two seperate things. First it adds a file called
"__libcpp_version" which only contains the current libc++ version
(currently 4000). This file is not intended for use as a header. This file
is used by Clang in order to easily determine the installed libc++ version.
This allows Clang to enable/disable certain language features only when the
library supports them.

The second change is the addition of _LIBCPP_LIBRARY_VERSION macro, which
returns the version of the installed dylib since it may be different than
the headers.


git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@285382 91177308-0d34-0410-b5e6-96231b3b80d8
2016-10-28 06:06:50 +00:00
Eric Fiselier
a469f83b26 Revert r282345 - Use __attribute__((internal_linkage)) when available.
git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@284101 91177308-0d34-0410-b5e6-96231b3b80d8
2016-10-13 04:07:58 +00:00
Eric Fiselier
35ce4859dd Implement N4606 optional
Summary:
Adapt implementation of Library Fundamentals TS optional into an implementation of N4606 optional.

  - Update relational operators per http://wg21.link/P0307
  - Update to requirements of http://wg21.link/P0032
  - Extension: Implement trivial copy/move construction/assignment for `optional<T>` when `T` is trivially copyable.

Audit P/Rs for optional LWG issues:
  - 2756 "C++ WP optional<T> should 'forward' T's implicit conversions" Implemented, which also resolves 2753 "Optional's constructors and assignments need constraints" (modulo my refusal to explicitly delete the move operations, which is a design error that I'm working on correcting in the 2756 P/R).
  - 2736 "nullopt_t insufficiently constrained" Already conforming. I've added a test ensuring that `nullopt_t` is not copy-initializable from an empty braced-init-list, which I believe is the root intent of the issue, to avoid regression.
  - 2740 "constexpr optional<T>::operator->" Already conforming.
  - 2746 "Inconsistency between requirements for emplace between optional and variant" No P/R, but note that the author's '"suggested resolution" is already implemented.
  - 2748 "swappable traits for optionals" Already conforming.
  - 2753 "Optional's constructors and assignments need constraints" Implemented.

Most of the work for this patch was done by Casey Carter @ Microsoft. Thank you Casey!



Reviewers: mclow.lists, CaseyCarter, EricWF

Differential Revision: https://reviews.llvm.org/D22741

git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@283980 91177308-0d34-0410-b5e6-96231b3b80d8
2016-10-12 07:46:20 +00:00
Eric Fiselier
ead5d404cc Revert Add <optional>. Will recommit with better commit message
git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@283978 91177308-0d34-0410-b5e6-96231b3b80d8
2016-10-12 06:48:31 +00:00
Eric Fiselier
fbc80168bb Add <optional> header.
This patch is largely thanks to Casey Carter @ Microsoft. He did the initial
work of porting our experimental implementation and tests over to namespace
std.


git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@283977 91177308-0d34-0410-b5e6-96231b3b80d8
2016-10-12 06:45:11 +00:00
Petr Hosek
bf1f79c27a [libcxx] Add support for Fuchsia
Fuchsia is a new operating system which uses musl as the standard
C library, libc++ and libc++abi as the C++ standard library.

Differential Revision: https://reviews.llvm.org/D25414

git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@283788 91177308-0d34-0410-b5e6-96231b3b80d8
2016-10-10 18:53:32 +00:00
Eric Fiselier
a62e1dd729 Fix PR30642 - libc++ leaks always-visible symbols into programs
This was caused by r281673, specifically changing `_LIBCPP_EXTERN_TEMPLATE_TYPE_VIS`
from `__attribute__((__type_visibility__("default")))` to
`__attribute__((__visibility("default")))`.

I made that change because I thought the external instantiations needed
their members to have default visibility. However since libc++ never builds
with -fvisibility=hidden this appears not to be needed. Instead this change
caused previously hidden inline methods to become un-hidden, which is a regression.

This patch reverts the problematic change and fixes PR30642.


git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@283620 91177308-0d34-0410-b5e6-96231b3b80d8
2016-10-07 23:07:59 +00:00
Eric Fiselier
1d6b5d3ed1 Fix strict-aliasing violation in typeinfo::hash_code()
Summary:
The current implementation of `hash_code()` for uniqued RTTI strings violates strict aliasing by dereferencing a type-punned pointer. Specifically it generates a `const char**` pointer from the address of the `__name` member before casting it to `const size_t*` and dereferencing it to get the hash. This is really just a complex and incorrect way of writing `reinterpret_cast<size_t>(__name)`.

This patch changes the conversion sequence so that it no longer contains UB.


Reviewers: howard.hinnant, mclow.lists

Subscribers: rjmccall, cfe-commits

Differential Revision: https://reviews.llvm.org/D24012

git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@283408 91177308-0d34-0410-b5e6-96231b3b80d8
2016-10-05 22:55:10 +00:00
Eric Fiselier
74c9857af9 Expect DLL builds on Windows by default and require a custom __config for static
builds.

On Windows the __declspec(dllimport) and __declspec(dllexport) attributes
require linking to a DLL, not a static library. Previously these annotations
were disabled by default unless _LIBCPP_DLL was defined. However the DLL
configuration is probably the more common one, so it should be supported by
default.

This patch enables import/export attributes by default and adds a
_LIBCPP_DISABLE_DLL_IMPORT_EXPORT macro which can be used to disable this
behavior. If libc++ is built as a static library on Windows then a custom __config
header will be generated that predefines this macro.

This patch is based off work by Shoaib Meenai.


git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@282449 91177308-0d34-0410-b5e6-96231b3b80d8
2016-09-26 22:19:41 +00:00
Eric Fiselier
4e3e15ad99 [libc++] Remove various C++03 feature test macros
Summary:
Libc++ still uses per-feature configuration macros when configuring for C++11. However libc++ requires a feature-complete C++11 compiler so there is no reason to check individual features. This patch starts the process of removing the feature specific macros and replacing their usage with `_LIBCPP_CXX03_LANG`.

This patch removes the __config macros:

* _LIBCPP_HAS_NO_TRAILING_RETURN
* _LIBCPP_HAS_NO_TEMPLATE_ALIASES
* _LIBCPP_HAS_NO_ADVANCED_SFINAE
* _LIBCPP_HAS_NO_DEFAULT_FUNCTION_TEMPLATE_ARGS
* _LIBCPP_HAS_NO_STATIC_ASSERT

As a drive I also changed our C++03 static_assert to use _Static_assert if available.

I plan to commit this without review if nobody voices an objection.

Reviewers: mclow.lists

Subscribers: cfe-commits

Differential Revision: https://reviews.llvm.org/D24895

git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@282347 91177308-0d34-0410-b5e6-96231b3b80d8
2016-09-25 03:34:28 +00:00
Eric Fiselier
1deaf196f4 Use __attribute__((internal_linkage)) when available.
Summary:
This patch has been a long time coming (Thanks @eugenis). It changes `_LIBCPP_INLINE_VISIBILITY` to use `__attribute__((internal_linkage))` instead of `__attribute__((visibility("hidden"), always_inline))`.

The point of `_LIBCPP_INLINE_VISIBILITY` is to prevent inline functions from being exported from both the libc++ library and from user libraries. This helps libc++ better manage it's ABI.
Previously this was done by forcing inlining and modifying the symbols visibility. However inlining isn't guaranteed and symbol visibility only affects shared libraries making this an imperfect solution.  `internal_linkage` improves this situation by making all symbols local to the TU they are emitted in, regardless of inlining or visibility. IIRC the effect of applying `__attribute__((internal_linkage))` to an inline function is the same as applying `static`.

For more information about the attribute see: http://lists.llvm.org/pipermail/cfe-dev/2015-October/045580.html

Most of the work for this patch was done by @eugenis.


Reviewers: mclow.lists, eugenis

Subscribers: eugenis, cfe-commits

Differential Revision: https://reviews.llvm.org/D24642

git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@282345 91177308-0d34-0410-b5e6-96231b3b80d8
2016-09-25 03:14:13 +00:00
Shoaib Meenai
e5cbce437b [libc++] Fix extern template visibility for Windows
On Windows, marking an `extern template class` declaration as exported
actually forces an instantiation, which is not the desired behavior.
Instead, the actual explicit instantiations need to be exported.

Differential Revision: https://reviews.llvm.org/D24679

git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@281925 91177308-0d34-0410-b5e6-96231b3b80d8
2016-09-19 18:29:07 +00:00
Dan Albert
7d7f3cc9b1 Replace __ANDROID__ with __BIONIC__.
Summary:
None of these checks are specific to Android devices. If libc++ was
used with Bionic on a normal Linux system these checks would still be
needed.

Reviewers: mclow.lists, EricWF

Subscribers: compnerd, tberghammer, danalbert, srhines, cfe-commits

Differential Revision: https://reviews.llvm.org/D24690

git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@281921 91177308-0d34-0410-b5e6-96231b3b80d8
2016-09-19 18:00:45 +00:00
Shoaib Meenai
e81a54c002 [libc++] Fix inline attribute for non-MSVC Windows
gcc and clang in gcc compatibility mode do not accept __forceinline. Use
the gcc attribute for them instead.

Differential Revision: https://reviews.llvm.org/D24678

git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@281766 91177308-0d34-0410-b5e6-96231b3b80d8
2016-09-16 19:12:54 +00:00
Eric Fiselier
6dbed46df6 [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

git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@281681 91177308-0d34-0410-b5e6-96231b3b80d8
2016-09-16 00:00:48 +00:00
Eric Fiselier
833d644ed1 [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

git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@281673 91177308-0d34-0410-b5e6-96231b3b80d8
2016-09-15 22:27:07 +00:00
Shoaib Meenai
8b8913084d config: Use _LIBCPP_TYPE_VIS_ONLY with enum class
An enum class has associated type info. In the Microsoft ABI, type info
is emitted in the COMDAT section and isn't exported, so clang rightfully
complains about __declspec(dllexport) being unused for an enum class.
On other platforms, we still want to export the type info.

Differential Revision: https://reviews.llvm.org/D24065

git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@281264 91177308-0d34-0410-b5e6-96231b3b80d8
2016-09-12 21:41:12 +00:00
Shoaib Meenai
b6b8e1ef3a config: Fix typo in comment
Testing commit access. NFC.

git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@281250 91177308-0d34-0410-b5e6-96231b3b80d8
2016-09-12 20:14:44 +00:00
Asiri Rathnayake
040945b81f [libcxx] Introduce an externally-threaded libc++ variant.
This patch further decouples libc++ from pthread, allowing libc++ to be built
against other threading systems. There are two main use cases:

- Building libc++ against a thread library other than pthreads.

- Building libc++ with an "external" thread API, allowing a separate library to
  provide the implementation of that API.

The two use cases are quite similar, the second one being sligtly more
de-coupled than the first. The cmake option LIBCXX_HAS_EXTERNAL_THREAD_API
enables both kinds of builds. One needs to place an <__external_threading>
header file containing an implementation of the "libc++ thread API" declared
in the <__threading_support> header.

For the second use case, the implementation of the libc++ thread API can
delegate to a custom "external" thread API where the implementation of this
external API is provided in a seperate library. This mechanism allows toolchain
vendors to distribute a build of libc++ with a custom thread-porting-layer API
(which is the "external" API above), platform vendors (recipients of the
toolchain/libc++) are then required to provide their implementation of this API
to be linked with (end-user) C++ programs.

Note that the second use case still requires establishing the basic types that
get passed between the external thread library and the libc++ library
(e.g. __libcpp_mutex_t). These cannot be opaque pointer types (libc++ sources
won't compile otherwise). It should also be noted that the second use case can
have a slight performance penalty; as all the thread constructs need to cross a
library boundary through an additional function call.

When the header <__external_threading> is omitted, libc++ is built with the
"libc++ thread API" (declared in <__threading_support>) as the "external" thread
API (basic types are pthread based). An implementation (pthread based) of this
API is provided in test/support/external_threads.cpp, which is built into a
separate DSO and linked in when running the libc++ test suite. A test run
therefore demonstrates the second use case (less the intermediate custom API).

Differential revision: https://reviews.llvm.org/D21968

Reviewers: bcraig, compnerd, EricWF, mclow.lists

git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@281179 91177308-0d34-0410-b5e6-96231b3b80d8
2016-09-11 21:46:40 +00:00
Eric Fiselier
766a31af3a Define _LIBCPP_SAFE_STATIC __attribute__((require_constant_initialization)), and apply it to memory_resource
git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@280561 91177308-0d34-0410-b5e6-96231b3b80d8
2016-09-03 00:11:33 +00:00
Eric Fiselier
3ec6b84545 Fix or suppress GCC warnings during build.
Summary:
Currently a number of GCC warnings are emitted when building libc++. This patch fixes or ignores all of them. The primary changes are:

* Work around strict aliasing issues in `typeinfo::hash_code()` by using __attribute__((may_alias)). However I think a non-aliasing `hash_code()` implementation is possible. Further investigation needed.
* Add `_LIBCPP_UNREACHABLE()` to switch in `strstream.cpp` to avoid -Wpotentially-uninitialized.
* Fix -Wunused-value warning in `__all` by adding a void cast.
* Ignore -Wattributes for now. There are a number of real attribute issues when using GCC but enabling the warning is too noisy.
* Ignore -Wliteral-suffix since it warns about the use of reserved identifiers. Note Only GCC 7.0 supports disabling this warning.
* Ignore -Wc++14-compat since it warns about the sized new/delete overloads.



Reviewers: EricWF

Differential Revision: https://reviews.llvm.org/D24003

git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@280007 91177308-0d34-0410-b5e6-96231b3b80d8
2016-08-29 20:43:38 +00:00
Eric Fiselier
f6535885b9 Fix undefined behavior in __hash_table
Summary:
This patch attempts to fix the undefined behavior in __hash_table by changing the node pointer types used throughout. The pointer types are changed for raw pointers in the current ABI and for fancy pointers in ABI V2 (since the fancy pointer types may not be ABI compatible).

The UB in `__hash_table` arises because tree downcasts the embedded end node and then deferences that pointer. Currently there are 2 node types in __hash_table:

* `__hash_node_base` which contains the `__next_` pointer.
* `__hash_node` which contains `__hash_` and `__value_`.

Currently the bucket list, iterators, and `__next_` pointers store pointers to `__hash_node` even though they all need to store `__hash_node_base` pointers.
This patch makes that change by introducing a `__next_pointer` typedef which is a pointer to `__hash_node` in the current ABI and `__hash_node_base` afterwards.

One notable change is to the type of `__bucket_list` which used to be defined as `unique_ptr<__node_pointer[], ...>` and is now `unique_ptr<__next_pointer[], ...>` meaning that we now allocate and deallocate different types using a different allocator. I'm going to give this part of the change more thought since it may introduce compatibility issues.

This change is similar to D20786.



Reviewers: mclow.lists, EricWF

Subscribers: cfe-commits

Differential Revision: https://reviews.llvm.org/D20787

git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@276533 91177308-0d34-0410-b5e6-96231b3b80d8
2016-07-23 20:36:55 +00:00
Eric Fiselier
7310ec83f3 Fix undefined behavior in __tree
Summary:
This patch attempts to fix the undefined behavior in __tree by changing the node pointer types used throughout. The pointer types are changed for raw pointers in the current ABI and for fancy pointers in ABI V2 (since the fancy pointer types may not be ABI compatible).

The UB in `__tree` arises because tree downcasts the embedded end node and then deferences that pointer. Currently there are 3 node types in __tree.

* `__tree_end_node` which contains the `__left_` pointer. This node is embedded within the container.
* `__tree_node_base` which contains `__right_`, `__parent_` and `__is_black`. This node is used throughout the tree rebalancing algorithms.
* `__tree_node` which contains `__value_`.

Currently `__tree` stores the start of the tree, `__begin_node_`, as a pointer to a `__tree_node`. Additionally the iterators store their position as a pointer to a `__tree_node`. In both of these cases the pointee can be the end node. This is fixed by changing them to store `__tree_end_node` pointers instead.

To make this change I introduced an `__iter_pointer` typedef which is defined to be a pointer to either `__tree_end_node` in the new ABI or `__tree_node` in the current one.
Both `__tree::__begin_node_` and iterator pointers are now stored as `__iter_pointers`.

The other situation where `__tree_end_node` is stored as the wrong type is in `__tree_node_base::__parent_`.  Currently `__left_`, `__right_`, and `__parent_` are all `__tree_node_base` pointers. Since the end node will only be stored in `__parent_` the fix is to change `__parent_` to be a pointer to `__tree_end_node`.

To make this change I introduced a `__parent_pointer` typedef which is defined to be a pointer to either `__tree_end_node` in the new ABI or `__tree_node_base` in the current one.

Note that in the new ABI `__iter_pointer` and `__parent_pointer` are the same type (but not in the old one). The confusion between these two types is unfortunate but it was the best solution I could come up with that maintains the ABI.

The typedef changes force a ton of explicit type casts to correct pointer types and to make current code compatible with both the old and new pointer typedefs. This is the bulk of the change and it's really messy. Unfortunately I don't know how to avoid it.

Please let me know what you think.





Reviewers: howard.hinnant, mclow.lists

Subscribers: howard.hinnant, bbannier, cfe-commits

Differential Revision: https://reviews.llvm.org/D20786

git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@276003 91177308-0d34-0410-b5e6-96231b3b80d8
2016-07-19 17:56:20 +00:00
Marshall Clow
fc8847cefa Bump version # to 4.0.0
git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@275904 91177308-0d34-0410-b5e6-96231b3b80d8
2016-07-18 20:27:19 +00:00
Eric Fiselier
c71c304663 Rename and rework _LIBCPP_TRIVIAL_PAIR_COPY_CTOR. Move FreeBSD configuration in-tree.
This patch does the following:

* It renames `_LIBCPP_TRIVIAL_PAIR_COPY_CTOR` to `_LIBCPP_DEPRECATED_ABI_DISABLE_PAIR_TRIVIAL_COPY_CTOR`.
* It automatically enables this option on FreeBSD in ABI V1, since that's the current ABI FreeBSD ships.
* It cleans up the handling of this option in `std::pair`.

I would like the sign off from the FreeBSD maintainers. They will no longer need to keep their `__config` changes downstream.

I'm still hoping to come up with a better way to maintain the ABI without needing these constructors.

Reviewed in https://reviews.llvm.org/D21329


git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@275749 91177308-0d34-0410-b5e6-96231b3b80d8
2016-07-18 01:58:37 +00:00
Eric Fiselier
83d7ca9ea5 Implement P0163r0. Add shared_ptr::weak_type.
This patch adds the weak_type typedef in shared_ptr. It is available in
C++17 and newer.

This patch also updates the _LIBCPP_STD_VER and TEST_STD_VER macros to
have the value of 16, since 2016 is the current year.


git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@273839 91177308-0d34-0410-b5e6-96231b3b80d8
2016-06-27 01:02:43 +00:00
Eric Fiselier
d9e1819ef4 Partially Revert r272613. FreeBSD needs the non-trivial constructors in pair.
git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@272671 91177308-0d34-0410-b5e6-96231b3b80d8
2016-06-14 14:34:19 +00:00
Eric Fiselier
10b52a0e56 Implement variadic lock_guard.
Summary:
This patch implements the variadic `lock_guard` paper. 

Making `lock_guard` variadic is a ABI breaking change because the specialization `lock_guard<_Mutex>` mangles differently then when it was the primary template. This change only provides variadic `lock_guard` in ABI V2 or when `_LIBCPP_ABI_VARIADIC_LOCK_GUARD` is defined.

Note that in ABI V2 `lock_guard` must always be declared as a variadic template, even in C++03, in order to keep the ABI consistent. For this reason `lock_guard` is forward declared as a variadic template in all standard dialects and therefore depends on variadic templates being provided as an extension in C++03. All supported versions of Clang and GCC provide this extension.




Reviewers: mclow.lists

Subscribers: K-ballo, mclow.lists, cfe-commits

Differential Revision: http://reviews.llvm.org/D21260

git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@272634 91177308-0d34-0410-b5e6-96231b3b80d8
2016-06-14 03:48:09 +00:00
Eric Fiselier
bf5a4189d3 Remove _LIBCPP_TRIVIAL_PAIR_COPY_CTOR option.
git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@272613 91177308-0d34-0410-b5e6-96231b3b80d8
2016-06-14 01:36:15 +00:00
Ben Craig
5163e46afb [libcxx] Allow explicit pthread opt-in
The existing pthread detection code in __config is pretty good for
common operating systems. It doesn't allow cmake-time choices to be
made for uncommon operating systems though.

This change adds the LIBCXX_HAS_PTHREAD_API cmake flag, which turns
into the _LIBCPP_HAS_THREAD_API_PTHREAD preprocessor define. This is
a name change from the old _LIBCPP_THREAD_API_PTHREAD. The lit tests
want __config_site.in variables to have a _LIBCPP_HAS prefix.

http://reviews.llvm.org/D20573


git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@270735 91177308-0d34-0410-b5e6-96231b3b80d8
2016-05-25 17:40:09 +00:00
Eric Fiselier
8c8f0e5b65 Enable Pthread threading API on Solaris. Fix PR27677
git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@268860 91177308-0d34-0410-b5e6-96231b3b80d8
2016-05-07 17:05:46 +00:00
Asiri Rathnayake
35ff03b7c2 Refactor pthread usage of libcxx.
This patch extracts out all the pthread dependencies of libcxx into the
new header __threading_support. The motivation is to make it easy to
re-target libcxx into platforms that do not support pthread.

Original patch from Fulvio Esposito (fulvio.esposito@outlook.com) - D11781

Applied with tweaks - D19412

Change-Id: I301111f0075de93dd8129416e06babc195aa936b

git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@268734 91177308-0d34-0410-b5e6-96231b3b80d8
2016-05-06 14:06:29 +00:00
Eric Fiselier
566bcb4bad Fix most GCC attribute ignored warnings
git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@267074 91177308-0d34-0410-b5e6-96231b3b80d8
2016-04-21 22:54:21 +00:00
Weiming Zhao
994fb967d3 [libc++] fix macro redef warning when exception is disabled
Summary:
 when setting LIBCXX_ENABLE_EXCEPTIONS=false, _LIBCPP_NO_EXCEPTIONS wil be defined in both commandline and _config

Reviewers: bcraig, EricWF

Subscribers: cfe-commits

Differential Revision: http://reviews.llvm.org/D19344

git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@266956 91177308-0d34-0410-b5e6-96231b3b80d8
2016-04-21 05:28:18 +00:00
Eric Fiselier
db21506d13 Teach __tree how to handle map's __value_type
This patch is fairly large and contains a number of changes. The changes all work towards
allowing __tree to properly handle __value_type esspecially when inserting into the __tree.
I chose not to break this change into smaller patches because it wouldn't be possible to
write meaningful standard-compliant tests for each patch.

It is very similar to r260513 "[libcxx] Teach __hash_table how to handle unordered_map's __hash_value_type".

Changes in <map>
 * Remove __value_type's constructors because it should never be constructed directly.

 * Make map::emplace and multimap::emplace forward to __tree and remove the old definitions

 * Remove "__construct_node" map and multimap member functions. Almost all of the construction is done within __tree.

 * Fix map's move constructor to access "__value_type.__nc" directly and pass this object to __tree::insert.

Changes in <__tree>
 * Add traits to detect, handle, and unwrap, map's "__value_type".

 * Convert methods taking "value_type" to take "__container_value_type" instead. Previously these methods caused
  unwanted implicit conversions from "std::pair<Key, Value>" to "__value_type<Key, Value>".

 * Delete __tree_node and __tree_node_base's constructors and assignment operators. The node types should never be constructed
   because the "__value_" member of __tree_node must be constructed directly by the allocator.

 * Make the __tree_node_destructor class and "__construct_node" methods unwrap "__node_value_type" into "__container_value_type" before invoking the allocator. The user's allocator can only be used to construct and destroy the container's value_type. Passing it map's "__value_type" was incorrect.

 * Cleanup the "__insert" and "__emplace" methods. Have __insert forward to an __emplace function wherever possible to reduce
   code duplication. __insert_unique(value_type const&) and __insert_unique(value_type&&) forward to __emplace_unique_key_args.
   These functions will not allocate a new node if the value is already in the tree.

 * Change the __find* functions to take the "key_type" directly instead of passing in "value_type" and unwrapping the key later.
   This change allows the find functions to be used without having to construct a "value_type" first. This allows for a number
   of optimizations.

 * Teach __move_assign and __assign_multi methods to unwrap map's __value_type.

git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@264986 91177308-0d34-0410-b5e6-96231b3b80d8
2016-03-31 02:15:15 +00:00
Eric Fiselier
735026e3ee Make std::addressof constexpr in C++17 (Clang only).
git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@263688 91177308-0d34-0410-b5e6-96231b3b80d8
2016-03-17 03:30:56 +00:00
Eric Fiselier
a15e8c3a18 Add clang thread safety annotations to mutex and lock_guard. Patch by jamesr@google.com.
This adds clang thread safety annotations to std::mutex and
std::lock_guard so code using these types can use these types directly
instead of having to wrap the types to provide annotations. These checks
when enabled by -Wthread-safety provide simple but useful static
checking to detect potential race conditions.
See http://clang.llvm.org/docs/ThreadSafetyAnalysis.html for details.

This patch was reviewed in http://reviews.llvm.org/D14731.


git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@263611 91177308-0d34-0410-b5e6-96231b3b80d8
2016-03-16 02:30:06 +00:00
Eric Fiselier
2960ae20e2 Teach __hash_table how to handle unordered_map's __hash_value_type.
This patch is fairly large and contains a number of changes. The main change
is teaching '__hash_table' how to handle '__hash_value_type'. Unfortunately
this change is a rampant layering violation, but it's required to make
unordered_map conforming without re-writing all of __hash_table.
After this change 'unordered_map' can delegate to '__hash_table' in almost all cases.

The major changes found in this patch are:

  * Teach __hash_table to differentiate between the true container value type
    and the node value type by introducing the "__container_value_type" and
    "__node_value_type" typedefs. In the case of unordered_map '__container_value_type'
    is 'pair<const Key, Value>' and '__node_value_type' is '__hash_value_type'.
    
  * Switch almost all overloads in '__hash_table' previously taking 'value_type'
    (AKA '__node_value_type) to take  '__container_value_type' instead. Previously
    'pair<K, V>' would be implicitly converted to '__hash_value_type<K, V>' because
    of the function signature.
    
  * Add '__get_key', '__get_value', '__get_ptr', and '__move' static functions to
    '__key_value_types'. These functions allow '__hash_table' to unwrap
    '__node_value_type' objects into '__container_value_type' and its sub-parts.

  * Pass  '__hash_value_type::__value_'  to 'a.construct(p, ...)' instead of
    '__hash_value_type' itself. The C++14 standard requires that 'a.construct()'
    and 'a.destroy()' are only ever instantiated for the containers value type.

  * Remove '__hash_value_type's constructors and destructors. We should never
    construct an instance of this type.
    (TODO this is UB but we already do it in plenty of places).
  
  * Add a generic "try-emplace" function to '__hash_table' called
    '__emplace_unique_key_args(Key const&, Args...)'.

  
The following changes were done as cleanup:

  * Introduce the '_LIBCPP_CXX03_LANG' macro to be used in place of
    '_LIBCPP_HAS_NO_VARIADICS' or '_LIBCPP_HAS_NO_RVALUE_REFERENCE'.
    
  * Cleanup C++11 only overloads that assume an incomplete C++11 implementation.
    For example this patch removes the __construct_node overloads that do
    manual pack expansion.
    
  * Forward 'unordered_map::emplace' to '__hash_table' and remove dead code
    resulting from the change. This includes almost all
    'unordered_map::__construct_node' overloads.


The following changes are planed for future revisions:

  * Fix LWG issue #2469 by delegating 'unordered_map::operator[]' to use
    '__emplace_unique_key_args'.
    
  * Rewrite 'unordered_map::try_emplace' in terms of '__emplace_unique_key_args'.
  
  * Optimize '__emplace_unique' to call '__emplace_unique_key_args' when possible.
    This prevent unneeded allocations when inserting duplicate entries.


The additional follow up work needed after this patch:

  * Respect the lifetime rules for '__hash_value_type' by actually constructing it.
  * Make '__insert_multi' act similar to '__insert_unique' for objects of type
    'T&' and 'T const &&' with 'T = __container_value_type'.
  
  

git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@260513 91177308-0d34-0410-b5e6-96231b3b80d8
2016-02-11 11:59:44 +00:00
Evgeniy Stepanov
45dca2c495 Fix invalid casts in <functional>.
static_cast of a pointer to object before the start of the object's
lifetime has undefined behavior.

This code triggers CFI warnings.

This change replaces C-style casts with reinterpret_cast, which is
fine per the standard, add applies an attribute to silence CFI (which
barks on reinterpret_cast, too).

git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@260441 91177308-0d34-0410-b5e6-96231b3b80d8
2016-02-10 21:53:28 +00:00
Eric Fiselier
774c7c5ca8 Recommit r260012 - Cleanup node-type handling in the unordered containers.
This time I kept <ext/hash_map> working!

This patch is the first in a series of patches that's meant to better
support unordered_map. unordered_map has a special "value_type" that
differs from pair<const Key, Value>. In order to meet the EmplaceConstructible
and CopyInsertable requirements we need to teach __hash_table about this
special value_type.

This patch creates a "__hash_node_types" traits class that contains
all of the typedefs needed by the unordered containers and it's iterators.
These typedefs include ones for each node type and  node pointer type,
as well as special typedefs for "unordered_map"'s value type.

As a result of this change all of the unordered containers now all support
incomplete types.

As a drive-by fix I changed the difference_type in __hash_table to always
be ptrdiff_t. There is a corresponding change to size_type but it cannot
take affect until an ABI break.

This patch will be followed up shortly with fixes for various unordered_map
bugs and problems.


git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@260431 91177308-0d34-0410-b5e6-96231b3b80d8
2016-02-10 20:46:23 +00:00
Ben Craig
f8865b62c3 Limit catopen usage to unix-like OSes
Operating systems that are not unix-like are unlikely to have access to
catopen. Instead of black-listing each one, we now filter out all non-unix
operating systems first. We then exclude the unix-like operating systems
that don't have catopen. _WIN32 counts as a unix-like operating system
because of cygwin.

http://reviews.llvm.org/D16639


git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@260381 91177308-0d34-0410-b5e6-96231b3b80d8
2016-02-10 13:47:25 +00:00
Richard Smith
b4aa97130b Fix overload sets of strchr, strpbrk, strrchr, memchr and strstr from
<string.h> and wcschr, wcspbrk, wcsrchr, wmemchr, and wcsstr from <wchar.h> to
provide a const-correct overload set even when the underlying C library does
not.

This change adds a new macro, _LIBCPP_PREFERRED_OVERLOAD, which (if defined)
specifies that a given overload is a better match than an otherwise equally
good function declaration without the overload. This is implemented in modern
versions of Clang via __attribute__((enable_if)), and not elsewhere.

We use this new macro to define overloads in the global namespace for these
functions that displace the overloads provided by the C library, unless we
believe the C library is already providing the correct signatures.


git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@260337 91177308-0d34-0410-b5e6-96231b3b80d8
2016-02-10 00:59:02 +00:00