Commit Graph

32 Commits

Author SHA1 Message Date
Louis Dionne 385cc25a53 [libc++] Ensure that all public C++ headers include <__assert>
This patch changes the requirement for getting the declaration of the
assertion handler from including <__assert> to including any public
C++ header of the library. Note that C compatibility headers are
excluded because we don't implement all the C headers ourselves --
some of them are taken straight from the C library, like assert.h.

It also adds a generated test to check it. Furthermore, this new
generated test is designed in a way that will make it possible to
replace almost all the existing test-generation scripts with this
system in upcoming patches.

Differential Revision: https://reviews.llvm.org/D122506
2022-03-30 15:05:31 -04:00
Louis Dionne a805a15b28 [libc++] Remove workaround for missing declarations on Windows store apps
We don't need preprocessor logic to exclude those declarations when compiling for
the Windows App Store, because that is handled by using_if_exists now.

Differential Revision: https://reviews.llvm.org/D108632
2022-03-11 09:08:30 -05:00
Louis Dionne 21f73d5826 [libc++] Remove workaround for C11 features on compilers that don't support using_if_exists
Instead of carrying around #ifdefs to determine whether those functions
are available on the platform, unconditionally use the using_if_exists
attribute to import it into namespace std only when available. That was
the purpose of this attribute from the start.

This change means that trying to use libc++ with an old SDK (or on an
old platform for platforms that ship system headers in /usr/include)
will require a recent Clang that supports the using_if_exists attribute.
When using an older Clang or GCC, the underlying platform has to support
a C11 standard library.

Differential Revision: https://reviews.llvm.org/D108203
2022-03-11 09:06:43 -05:00
Nikolas Klauser 2a8f9a5e95 [libc++] Implement P0627R6 (Function to mark unreachable code)
Reviewed By: ldionne, Quuxplusone, #libc

Spies: arichardson, mstorsjo, libcxx-commits, mgorny

Differential Revision: https://reviews.llvm.org/D119152
2022-02-14 20:52:51 +01:00
Arthur O'Dwyer fa6b9e4010 [libc++] Normalize all our '#pragma GCC system_header', and regression-test.
Now we'll notice if a header forgets to include this magic phrase.

Differential Revision: https://reviews.llvm.org/D118800
2022-02-04 12:27:19 -05:00
Louis Dionne eb8650a757 [runtimes][NFC] Remove filenames at the top of the license notice
We've stopped doing it in libc++ for a while now because these names
would end up rotting as we move things around and copy/paste stuff.
This cleans up all the existing files so as to stop the spreading
as people copy-paste headers around.
2021-11-17 16:30:52 -05:00
Louis Dionne c137a0754c [libc++] Remove _LIBCPP_HAS_NO_LONG_LONG in favour of using_if_exists
_LIBCPP_HAS_NO_LONG_LONG was only defined on FreeBSD. Instead, use the
using_if_exists attribute to skip over declarations that are not available
on the base system. Note that there's an annoying limitation that we can't
conditionally define a function based on whether the base system provides
a function, so for example we still need preprocessor logic to define the
abs() and div() overloads.

Differential Revision: https://reviews.llvm.org/D108630
2021-09-03 14:26:59 -04:00
Louis Dionne a9c9183ca4 [libc++] Use the using_if_exists attribute when provided
As discussed on cfe-dev [1], use the using_if_exists Clang attribute when
the compiler supports it. This makes it easier to port libc++ on top of
new platforms that don't fully support the C Standard library.

Previously, libc++ would fail to build when trying to import a missing
declaration in a <cXXXX> header. With the attribute, the declaration will
simply not be imported into namespace std, and hence it won't be available
for libc++ to use. In many cases, the declarations were *not* actually
required for libc++ to work (they were only surfaced for users to use
them as std::XXXX), so not importing them into namespace std is acceptable.

The same thing could be achieved by conscious usage of `#ifdef` along
with platform detection, however that quickly creates a maintenance
problem as libc++ is ported to new platforms. Furthermore, this problem
is exacerbated when mixed with vendor internal-only platforms, which can
lead to difficulties maintaining a downstream fork of the library.

For the time being, we only use the using_if_exists attribute when it
is supported. At some point in the future, we will start removing #ifdef
paths that are unnecessary when the attribute is supported, and folks
who need those #ifdef paths will be required to use a compiler that
supports the attribute.

[1]: http://lists.llvm.org/pipermail/cfe-dev/2020-June/066038.html

Differential Revision: https://reviews.llvm.org/D90257
2021-06-04 09:55:21 -04:00
Louis Dionne 4cd6ca102a [libc++] NFC: Normalize `#endif //` comment indentation 2021-04-20 12:03:32 -04:00
Dan Albert 19fd9039ca Fix _LIBCPP_HAS_ definitions for Android.
Summary:
Android added quick_exit()/at_quick_exit() in API level 21,
aligned_alloc() in API level 28, and timespec_get() in API level 29,
but has the other C11 features at all API levels (since they're basically
just coming from clang directly).

_LIBCPP_HAS_QUICK_EXIT and _LIBCPP_HAS_TIMESPEC_GET already existed,
so we can reuse them. (And use _LIBCPP_HAS_TIMESPEC_GET in a few more
places where _LIBCPP_HAS_C11_FEATURES has been used as a proxy. This
isn't correct for Android.)

_LIBCPP_HAS_ALIGNED_ALLOC is added, to cover aligned_alloc() (obviously).

Add a missing std:: before aligned_alloc in a cstdlib test, and remove a
couple of !defined(_WIN32)s now that we're explicitly testing
TEST_HAS_ALIGNED_ALLOC rather than TEST_HAS_C11_FEATURES.

Reviewers: danalbert, EricWF, mclow.lists

Reviewed By: danalbert

Subscribers: srhines, christof, libcxx-commits

Tags: #libc

Differential Revision: https://reviews.llvm.org/D69929
2019-11-18 12:19:58 -08:00
Chandler Carruth 57b08b0944 Update more file headers across all of the LLVM projects in the monorepo
to reflect the new license. These used slightly different spellings that
defeated my regular expressions.

We understand that people may be surprised that we're moving the header
entirely to discuss the new license. We checked this carefully with the
Foundation's lawyer and we believe this is the correct approach.

Essentially, all code in the project is now made available by the LLVM
project under our new license, so you will see that the license headers
include that license only. Some of our contributors have contributed
code under our old license, and accordingly, we have retained a copy of
our old license notice in the top-level files in each project and
repository.

llvm-svn: 351648
2019-01-19 10:56:40 +00:00
Marshall Clow 171c77b7da Selectively import timespec_get into namespace std, since some C libraries don't have it. Reviewed as https://reviews.llvm.org/D50799
llvm-svn: 339816
2018-08-15 21:19:08 +00:00
Shoaib Meenai 5dc5a8e5be [libc++] Respect Windows Store app CRT restrictions
Some CRT APIs are unavailable for Windows Store apps [1]. Detect when
we're targeting the Windows Store and don't try to refer to non-existent
CRT functions in that case. (This would otherwise lead to a compile
error when using the libc++ headers and compiling for Windows Store.)

[1] https://docs.microsoft.com/en-us/cpp/cppcx/crt-functions-not-supported-in-universal-windows-platform-apps

Differential Revision: https://reviews.llvm.org/D31737

llvm-svn: 299625
2017-04-06 04:47:49 +00:00
Ed Schouten 0a92402436 Remove mblen(), mbtowc() and wctomb() from the thread-unsafe functions.
Back in r240527 I added a knob to prevent thread-unsafe functions from
being exposed. mblen(), mbtowc() and wctomb() were also added to this
list, as the latest issue of POSIX doesn't require these functions to be
thread-safe.

It turns out that the only circumstance in which these functions are not
thread-safe is in case they are used in combination with state-dependent
character sets (e.g., Shift-JIS). According to Austin Group Bug 708,
these character sets "[...] are mostly a relic of the past and which
were never supported on most POSIX systems".

Though in many cases the use of these functions can be prevented by
using the reentrant counterparts, they are the only functions that allow
you to query whether the locale's character set is state-dependent. This
means that omitting these functions removes actual functionality.

Let's be a bit less pedantic and drop the guards around these functions.

Links:
http://austingroupbugs.net/view.php?id=708
http://www.open-std.org/jtc1/sc22/wg14/www/docs/n2037.htm

Reviewed by:	ericwf
Differential Revision:	https://reviews.llvm.org/D21436

llvm-svn: 290748
2016-12-30 10:44:00 +00:00
Eric Fiselier f6ac565031 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

llvm-svn: 280007
2016-08-29 20:43:38 +00:00
Richard Smith a51c8eee6e Split <stdlib.h> out of <cstdlib>.
llvm-svn: 249800
2015-10-09 01:41:45 +00:00
Ed Schouten e0cf3b9a3c Make support for thread-unsafe C functions optional.
One of the aspects of CloudABI is that it aims to help you write code
that is thread-safe out of the box. This is very important if you want
to write libraries that are easy to reuse. For CloudABI we decided to
not provide the thread-unsafe functions. So far this is working out
pretty well, as thread-unsafety issues are detected really early on.

The following patch adds a knob to libc++,
_LIBCPP_HAS_NO_THREAD_UNSAFE_C_FUNCTIONS, that can be set to disable
thread-unsafe functions that can easily be avoided in practice. The
following functions are not thread-safe:

- <clocale>: locale handles should be preferred over setlocale().
- <cstdlib>: mbrlen(), mbrtowc() and wcrtomb() should be preferred over
  their non-restartable counterparts.
- <ctime>: asctime(), ctime(), gmtime() and localtime() are not
  thread-safe. The first two are also deprecated by POSIX.

Differential Revision:	http://reviews.llvm.org/D8703
Reviewed by:	marshall

llvm-svn: 240527
2015-06-24 08:44:38 +00:00
Ed Schouten 74bbf7c7ee Make *abs() and *div() work on CloudABI.
According to POSIX, *abs() and *div() are allowed to be macros (in
addition to being functions). Make sure we undefine these, so that
std::*abs() and std::*div() work as expected.

llvm-svn: 232379
2015-03-16 14:27:44 +00:00
Howard Hinnant 5d1a701d6d Xing Xue: port to IBM XLC++/AIX.
llvm-svn: 188396
2013-08-14 18:00:20 +00:00
Howard Hinnant 0be8f64c44 Nico Rieck: Currently _MSC_VER and _WIN32 are used to guard code which is
MSVC-specific, MSVCRT-specific, or Windows-specific. Because Clang can
also define _MSC_VER, and MSVCRT is not necessarily the only C runtime,
these macros should not be used interchangeably.

This patch divides all Windows-related bits into the aforementioned
categories. Two new macros are introduced:

- _LIBCPP_MSVC: Defined when compiling with MSVC. Detected using
  _MSC_VER, excluding Clang.
- _LIBCPP_MSVCRT: Defined when using the Microsoft CRT. This is the default
   when _WIN32 is defined.

This leaves _WIN32 for code using the Windows API.

This also corrects the spelling of _LIBCP_HAS_IS_BASE_OF to _LIBCPP_HAS_IS_BASE_OF.

Nico, please prepare a patch for CREDITS.TXT, thanks.

llvm-svn: 187593
2013-08-01 18:17:34 +00:00
Howard Hinnant f8b24cf5f7 Dimitry Andric: When using libc++ headers on FreeBSD, in combination with -std=c++98,
-ansi or -std=c++03, the long long type is not supported.  So in this
case, several functions and types, like lldiv_t, strtoll(), are not
declared.

llvm-svn: 168610
2012-11-26 21:18:17 +00:00
Howard Hinnant 7ba8160360 Dimitry Andric: FreeBSD only: Add the C11 aligned_alloc to <cstdlib> and adjust the inclusion of quick_exit.
llvm-svn: 165882
2012-10-13 18:03:53 +00:00
Howard Hinnant 9d6d1c6860 Apply noexcept to those functions implemented in <cstdlib> as a conforming extension.
llvm-svn: 159850
2012-07-06 19:16:56 +00:00
David Chisnall 5f13d66fb4 Make sure [at_]quick_exit is in std::
llvm-svn: 152717
2012-03-14 14:10:37 +00:00
David Chisnall 14c25b80e9 Solaris port. Currently sees around 200 test failures, mostly related to
Solaris not providing some of the locales that the test suite uses.

Note: This depends on an xlocale (partial) implementation for Solaris and a
couple of fixed standard headers.  These will be committed to a branch later
today.

llvm-svn: 151720
2012-02-29 13:05:08 +00:00
Howard Hinnant 9563a09cee Windows port work by Ruben Van Boxem
llvm-svn: 143105
2011-10-27 16:24:42 +00:00
Howard Hinnant e4383379ae More windows port work by Ruben Van Boxem
llvm-svn: 142732
2011-10-22 20:59:45 +00:00
Howard Hinnant 073458b1ab Windows support by Ruben Van Boxem.
llvm-svn: 142235
2011-10-17 20:05:10 +00:00
Howard Hinnant 412dbebe1b license change
llvm-svn: 119395
2010-11-16 22:09:02 +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