Commit Graph

153 Commits

Author SHA1 Message Date
Eric Fiselier 5de7cacf07 Make GCC in C++03 Unsupported
Summary:
This patch make G++03 explicitly unsupported with libc++, as discussed on the mailing lists.


Below is the rational for this decision.
----------------------------------------------------------------------------------------------------

libc++ claims to support GCC with C++03 ("G++03"), and this is a problem for our users.

Our C++03 users are all using Clang. They must be.  Less than 9% of the C++03 tests pass with GCC [1][2]. No non-trivial C++ program could work.

Attempting to support G++03 impacts our QoI considerably. Unlike Clang, G++03 offers almost no C++11 extensions. If we could remove all the fallbacks for G++03, it would mean libc++ could::

* Improve Correctness:

Every `#ifdef _LIBCPP_HAS_NO_<C++11-feature>` is a bug manifest. It exists to admit for deviant semantics.

* Achieve ABI stability between C++03 and C++11

Differences between our C++03 and C++Rest branches contain ABI bugs. For example `std::nullptr_t` and `std::function::operator()(...)` are currently incompatible between C++11 and C++03, but could be fixed.

* Decrease Compile Times and Memory Usage:

Writing efficient SFINAE requires C++11. Using alias templates, libc++ could reduce the number of instantiations it produces substantially.

* Decrease Binary Size

Similar to the last point, G++03 forces metaprogramming techniques that emit more debug information [3] [4]. Compared to libstdc++, debug information size increases of +10% are not uncommon.

Reviewers: ldionne, mclow.lists, EricWF

Reviewed By: ldionne, EricWF

Subscribers: zoecarver, aprantl, dexonsmith, arphaman, libcxx-commits, #libc

Differential Revision: https://reviews.llvm.org/D63154

llvm-svn: 363219
2019-06-13 00:37:25 +00:00
Eric Fiselier 4959542657 Add documentation and tests for Clangs C++11 extensions in C++03.
As we gear up to drop support for GCC in C++03, we should make clear
what our C++03 mode is, the C++11 extensions it provides,
and the C++11 extensions it depends on.

The section of this document discussing user-facing extensions has
been left blank while the community discusses new directions. For now
it's just a warning to users.

Additionally, the document contains examples of how these extensions
should be used and why. For example, using alias templates over class
templates.

llvm-svn: 363110
2019-06-11 22:53:49 +00:00
Louis Dionne 776acf225b [libcxx] Slightly improved policy for handling experimental features
Summary:
Following the discussion on the libcxx-dev mailing list
(http://lists.llvm.org/pipermail/libcxx-dev/2019-May/000358.html),
this implements the new policy for handling experimental features and
their deprecation. We basically add a deprecation warning for
std::experimental::filesystem, and we remove a bunch of <experimental/*>
headers that were now empty.

Reviewers: mclow.lists, EricWF

Subscribers: mgorny, christof, jkorous, dexonsmith, arphaman, libcxx-commits, jfb

Tags: #libc

Differential Revision: https://reviews.llvm.org/D62428

llvm-svn: 363072
2019-06-11 14:48:40 +00:00
Eric Fiselier 99dfd7084d update debugging docs to be less out of date
llvm-svn: 362866
2019-06-08 04:59:41 +00:00
J. Ryan Stinnett d45eaf9405 [Docs] Modernize references to macOS
Summary:
This updates all places in documentation that refer to "Mac OS X", "OS X", etc.
to instead use the modern name "macOS" when no specific version number is
mentioned.

If a specific version is mentioned, this attempts to use the OS name at the time
of that version:

* Mac OS X for 10.0 - 10.7
* OS X for 10.8 - 10.11
* macOS for 10.12 - present

Reviewers: JDevlieghere

Subscribers: mgorny, christof, arphaman, cfe-commits, lldb-commits, libcxx-commits, llvm-commits

Tags: #clang, #lldb, #libc, #llvm

Differential Revision: https://reviews.llvm.org/D62654

llvm-svn: 362113
2019-05-30 16:46:22 +00:00
Eric Fiselier 2405bd6898 Rework std::type_info definition to support systems without fully
merged type info names.

Previously std::type_info always expected type info string to be unique.
But this isn't always the case. Like when -Bsymbolic is passed to the
linker or due to llvm.org/PR37398.

This patch adds the LIBCXX_HAS_MERGED_TYPEINFO_NAMES_DEFAULT CMake
option which, when specified, overrides the default configuration for
the library.

The current defaults still assume unique names even though this isn't
strictly correct for ELF binaries. We should consider changing the
default in a follow up commit.

llvm-svn: 361913
2019-05-29 02:21:37 +00:00
Eric Fiselier ae02e89448 P0722R3: Implement library support for destroying delete
Summary:
This provides the `std::destroying_delete_t` declaration in C++2a and after. (Even when the compiler doesn't support the language feature).

However, the feature test macro `__cpp_lib_destroying_delete` is only defined when we have both language support and  C++2a.


Reviewers: ldionne, ckennelly, serge-sans-paille, EricWF

Reviewed By: EricWF

Subscribers: dexonsmith, riccibruno, christof, jwakely, jdoerfert, mclow.lists, ldionne, libcxx-commits

Differential Revision: https://reviews.llvm.org/D55840

llvm-svn: 361572
2019-05-23 23:46:44 +00:00
Marshall Clow d3d0ecbfd5 Implement midpoint for floating point types. Reviewed as https://reviews.llvm.org/D61014.
llvm-svn: 359184
2019-04-25 12:11:43 +00:00
Eric Fiselier 2fc5a786be Add std::is_constant_evaluated.
Clang recently added __builtin_is_constant_evaluated() and GCC 9.0
has it as well.

This patch adds support for it in libc++.

llvm-svn: 359119
2019-04-24 17:54:25 +00:00
Jonathan Metzman ff79ee144c Remove repeated words from BuildingLibcxx.rst
Summary: Remove repeated words from docs.

Reviewers: phosek

Reviewed By: phosek

Subscribers: christof

Differential Revision: https://reviews.llvm.org/D60530

llvm-svn: 358147
2019-04-10 23:44:27 +00:00
Nico Weber 1362d7ef88 libcxx: Add _LIBCPP_NODISCARD_EXT to 38 more functions
This builds on the work done in r342808 and adds _LIBCPP_NODISCARD_EXT
to 37 more functions, namely:

adjacent_find, all_of, any_of, binary_search, clamp, count_if, count,
equal_range, equal, find_end, find_first_not_of, find_first_of, find_if,
find, includes, is_heap_until, is_heap, is_partitioned, is_permutation,
is_sorted_until, is_sorted, lexicographical_compare, lower_bound,
max_element, max, min_element, min, minmax_element, minmax, mismatch,
none_of, remove_if, remove, search_n, search, unique, upper_bound

The motivation here is that we noticed that find_if is nodiscard with
Visual Studio's standard library, and we deemed that useful
(https://crbug.com/948122).
https://devblogs.microsoft.com/cppblog/c17-progress-in-vs-2017-15-5-and-15-6/
says "Our criteria for emitting the warning are: discarding the return
value is a guaranteed leak [...], discarding the return value is
near-guaranteed to be incorrect (e.g. remove()/remove_if()/unique()), or
the function is essentially a pure observer (e.g. vector::empty() and
std::is_sorted())." so I went through algorithm and tried to apply these
criteria.

Some of these, like vector::empty() are already nodiscard per C++
standard and didn't need changing.

I didn't (yet?) go over std::string::find* methods which should probably
have _LIBCPP_NODISCARD_EXT too (but not as part of this change).

Differential Revision: https://reviews.llvm.org/D60145

llvm-svn: 357619
2019-04-03 18:13:08 +00:00
Louis Dionne 952387251e [libc++] Re-document how to use <filesystem> with various versions of libc++
This documentation was removed when we added <filesystem> to the dylib
in r356518, but it really should have been updated to reflect the new
state of things. Keeping documentation around doesn't hurt and users
will have an easier time migrating.

llvm-svn: 356681
2019-03-21 16:21:09 +00:00
Eric Fiselier f1d87f8b4c Allow disabling of filesystem library.
Summary: Filesystem doesn't work on Windows, so we need a mechanism to turn it off for the time being.

Reviewers: ldionne, serge-sans-paille, EricWF

Reviewed By: EricWF

Subscribers: mstorsjo, mgorny, christof, jdoerfert, libcxx-commits

Differential Revision: https://reviews.llvm.org/D59619

llvm-svn: 356633
2019-03-21 00:04:31 +00:00
Louis Dionne 2d0b4d6bb3 [libc++][CMake] Clean up some of the libc++ re-exporting logic
Summary:
This change allows specifying the version of libc++abi's ABI to re-export
when configuring CMake. It also clearly identifies which ABI version of
libc++abi each export file contains.

Finally, it removes hardcoded knowledge about the 10.9 SDK for MacOS,
since that knowledge is not relevant anymore. Indeed, libc++ can't be
built with the toolchain that came with the 10.9 SDK anyway because
the version of Clang it includes is too old (for example if you want
to build a working libc++.dylib, you need bugfixes to visibility
attributes that are only in recent Clangs).

Reviewers: dexonsmith, EricWF

Subscribers: mgorny, christof, jkorous, arphaman, libcxx-commits

Differential Revision: https://reviews.llvm.org/D59489

llvm-svn: 356587
2019-03-20 18:16:24 +00:00
Louis Dionne cc37af7a36 [libc++] Build <filesystem> support as part of the dylib
Summary:
This patch treats <filesystem> as a first-class citizen of the dylib,
like all other sub-libraries (e.g. <chrono>). As such, it also removes
all special handling for installing the filesystem library separately
or disabling part of the test suite from the lit command line.

Unlike the previous attempt (r356500), this doesn't remove all the
filesystem tests.

Reviewers: mclow.lists, EricWF, serge-sans-paille

Subscribers: mgorny, christof, jkorous, dexonsmith, jfb, jdoerfert, libcxx-commits

Differential Revision: https://reviews.llvm.org/D59152

llvm-svn: 356518
2019-03-19 20:56:13 +00:00
Louis Dionne f7b43230b8 Revert "[libc++] Build <filesystem> support as part of the dylib"
When I applied r356500 (https://reviews.llvm.org/D59152), I somehow
deleted all of filesystem's tests. I will revert r356500 and re-apply
it properly.

llvm-svn: 356505
2019-03-19 19:27:29 +00:00
Louis Dionne 72122d058b [libc++] Build <filesystem> support as part of the dylib
Summary:
This patch treats <filesystem> as a first-class citizen of the dylib,
like all other sub-libraries (e.g. <chrono>). As such, it also removes
all special handling for installing the filesystem library separately
or disabling part of the test suite from the lit command line.

Reviewers: mclow.lists, EricWF, serge-sans-paille

Subscribers: mgorny, christof, jkorous, dexonsmith, jfb, jdoerfert, libcxx-commits

Differential Revision: https://reviews.llvm.org/D59152

llvm-svn: 356500
2019-03-19 19:09:33 +00:00
Louis Dionne a470a13a70 [libc++] Enable deprecation warnings by default
Summary:
In r342843, I added deprecation warnings to some facilities that were
deprectated in C++14 and C++17. However, those deprecation warnings
were not enabled by default.

After discussing this on IRC, we had finally gotten consensus to enable
those warnings by default, and I'm getting around to doing that only
now.

Reviewers: mclow.lists, EricWF

Subscribers: christof, jkorous, dexonsmith, jdoerfert, libcxx-commits

Differential Revision: https://reviews.llvm.org/D58140

llvm-svn: 355961
2019-03-12 20:10:06 +00:00
Petr Hosek 97bc08ae02 [CMake] Support compiler-rt builtins library in tests
We're building tests with -nostdlib which means that we need to
explicitly include the builtins library. When using libgcc (default)
we can simply include -lgcc_s on the link line, but when using
compiler-rt builtins we need a complete path to the builtins library.

This path is already available in CMake as <PROJECT>_BUILTINS_LIBRARY,
so we just need to pass that path to lit and if config.compiler_rt is
true, link it to the test.

Prior to this patch, running tests when compiler-rt is being used as
the builtins library was broken as all tests would fail to link, but
with this change running tests when compiler-rt bultins library is
being used should be supported.

Differential Revision: https://reviews.llvm.org/D56701

llvm-svn: 353208
2019-02-05 19:50:47 +00:00
Louis Dionne 51358e45e2 [libcxx] Start defining lit features for tests depending on availability
This patch removes some vendor-specific availability XFAILs from the
test suite. In the future, when a new feature is introduced in the
dylib, an availability macro should be created and a matching lit
feature should be created. That way, the test suite can XFAIL whenever
the implementation lacks the necessary feature instead of being
cluttered by vendor-specific annotations.

Right now, those vendor-specific annotations are still somewhat cluttering
the test suite by being in `config.py`, but at least they are localized.
In the future, we could design a way to define those less intrusively or
even automatically based on the availability macros that already exist
in <__config>.

llvm-svn: 353201
2019-02-05 19:22:38 +00:00
JF Bastien 2df59c5068 Support tests in freestanding
Summary:
Freestanding is *weird*. The standard allows it to differ in a bunch of odd
manners from regular C++, and the committee would like to improve that
situation. I'd like to make libc++ behave better with what freestanding should
be, so that it can be a tool we use in improving the standard. To do that we
need to try stuff out, both with "freestanding the language mode" and
"freestanding the library subset".

Let's start with the super basic: run the libc++ tests in freestanding, using
clang as the compiler, and see what works. The easiest hack to do this:

In utils/libcxx/test/config.py add:

  self.cxx.compile_flags += ['-ffreestanding']

Run the tests and they all fail.

Why? Because in freestanding `main` isn't special. This "not special" property
has two effects: main doesn't get mangled, and main isn't allowed to omit its
`return` statement. The first means main gets mangled and the linker can't
create a valid executable for us to test. The second means we spew out warnings
(ew) and the compiler doesn't insert the `return` we omitted, and main just
falls of the end and does whatever undefined behavior (if you're luck, ud2
leading to non-zero return code).

Let's start my work with the basics. This patch changes all libc++ tests to
declare `main` as `int main(int, char**` so it mangles consistently (enabling us
to declare another `extern "C"` main for freestanding which calls the mangled
one), and adds `return 0;` to all places where it was missing. This touches 6124
files, and I apologize.

The former was done with The Magic Of Sed.

The later was done with a (not quite correct but decent) clang tool:

  https://gist.github.com/jfbastien/793819ff360baa845483dde81170feed

This works for most tests, though I did have to adjust a few places when e.g.
the test runs with `-x c`, macros are used for main (such as for the filesystem
tests), etc.

Once this is in we can create a freestanding bot which will prevent further
regressions. After that, we can start the real work of supporting C++
freestanding fairly well in libc++.

<rdar://problem/47754795>

Reviewers: ldionne, mclow.lists, EricWF

Subscribers: christof, jkorous, dexonsmith, arphaman, miyuki, libcxx-commits

Differential Revision: https://reviews.llvm.org/D57624

llvm-svn: 353086
2019-02-04 20:31:13 +00:00
Eric Fiselier 508da4156a Move the feature test macros script to the utils directory.
It doesn't make a lot of sense to keep it with the tests,
deep into the test suite directonies.

llvm-svn: 352970
2019-02-02 23:13:49 +00:00
James Y Knight 5d71fc5d7b Adjust documentation for git migration.
This fixes most references to the paths:
 llvm.org/svn/
 llvm.org/git/
 llvm.org/viewvc/
 github.com/llvm-mirror/
 github.com/llvm-project/
 reviews.llvm.org/diffusion/

to instead point to https://github.com/llvm/llvm-project.

This is *not* a trivial substitution, because additionally, all the
checkout instructions had to be migrated to instruct users on how to
use the monorepo layout, setting LLVM_ENABLE_PROJECTS instead of
checking out various projects into various subdirectories.

I've attempted to not change any scripts here, only documentation. The
scripts will have to be addressed separately.

Additionally, I've deleted one document which appeared to be outdated
and unneeded:
  lldb/docs/building-with-debug-llvm.txt

Differential Revision: https://reviews.llvm.org/D57330

llvm-svn: 352514
2019-01-29 16:37:27 +00:00
Chandler Carruth bd9dafecf7 Update an example to use the new LLVM file header.
llvm-svn: 351653
2019-01-19 11:54:04 +00:00
Hans Wennborg 1fe469ae6c Bump the trunk version to 9.0.0svn
llvm-svn: 351320
2019-01-16 10:57:02 +00:00
Eric Fiselier 32784a740a Implement feature test macros using a script.
Summary:
This patch implements all the feature test macros libc++ currently supports, as specified by the standard or cppreference prior to C++2a.

The tests and `<version>` header are generated using a script. The script contains a table of each feature test macro, the headers it should be accessible from, and its values of each dialect of C++.
When a new feature test macro is added or needed, the table should be updated and the script re-run.



Reviewers: mclow.lists, jfb, serge-sans-paille

Reviewed By: mclow.lists

Subscribers: arphaman, jfb, ldionne, libcxx-commits

Differential Revision: https://reviews.llvm.org/D56750

llvm-svn: 351286
2019-01-16 01:37:43 +00:00
Petr Hosek a2685cd6dc [libcxx] Support building hermetic static library
This is useful when static libc++ library is being linked into
shared libraries that may be used in combination with libraries.
We want to avoid we exporting libc++ symbols in those cases where
this option is useful. This is provided as a CMake option and can
be enabled by libc++ vendors as needed.

Differential Revision: https://reviews.llvm.org/D55404

llvm-svn: 350489
2019-01-06 06:14:31 +00:00
Louis Dionne bc297b1da9 [libcxx] Make sure use_system_cxx_lib does not override cxx_runtime_root for DYLD_LIBRARY_PATH
Otherwise, even specifying a runtime root different from the library
we're linking against won't work -- the library we're linking against
is always used. This is undesirable if we try testing something like
linking against a recent libc++.dylib but running the tests against an
older version (the back-deployment use case).

llvm-svn: 349171
2018-12-14 18:19:14 +00:00
Louis Dionne 2112fbcc00 [libcxx] Remove the no_default_flags LIT configuration
This is part of an ongoing cleanup of the LIT test suite, where I'm
trying to reduce the number of configuration options. In this case,
the original intent seemed to be running the test suite with libstdc++,
but this is now supported by specifying cxx_stdlib_under_test=libstdc++.

llvm-svn: 348868
2018-12-11 17:29:55 +00:00
Louis Dionne 737be83d20 [libcxx] Remove the availability_markup LIT feature
It is now equivalent to the 'availability' LIT feature, so there's no
reason to keep both.

llvm-svn: 348653
2018-12-07 21:48:39 +00:00
Louis Dionne 3560fbf304 [libc++] Improve diagnostics for non-const comparators and hashers in associative containers
Summary:
When providing a non-const-callable comparator in a map or set, the
warning diagnostic does not include the point of instantiation of
the container that triggered the warning, which makes it difficult
to track down the problem. This commit improves the diagnostic by
placing it directly in the body of the associative container.

The same change is applied to unordered associative containers, which
had a similar problem.

Finally, this commit cleans up the forward declarations of several
map and unordered_map helpers, which are not needed anymore.

<rdar://problem/41370747>

Reviewers: EricWF, mclow.lists

Subscribers: christof, dexonsmith, llvm-commits

Differential Revision: https://reviews.llvm.org/D48955

llvm-svn: 348529
2018-12-06 21:46:17 +00:00
Louis Dionne f14927e98e [libcxx] Always enable availability in the lit test suite.
Summary:
Running the tests without availability enabled doesn't really make sense:
availability annotations allow catching errors at compile-time instead
of link-time. Running the tests without availability enabled allows
confirming that a test breaks at link-time under some configuration,
but it is more useful to instead check that it should fail at compile-time.

Always enabling availability in the lit test suite will greatly simplify
XFAILs and troubleshooting of failing tests, which is currently a giant
pain because we have these two levels of possible failure: link-time and
compile-time.

Reviewers: EricWF, mclow.lists

Subscribers: christof, jkorous, dexonsmith, libcxx-commits

Differential Revision: https://reviews.llvm.org/D55079

llvm-svn: 348296
2018-12-04 19:31:08 +00:00
Louis Dionne e823b6d7e6 [libcxx] Remove bad_array_length
Summary:
std::bad_array_length was added by n3467, but this never made it into C++.
This commit removes the definition of std::bad_array_length from the headers
AND from the shared library. See the comments in the ABI changelog for details
about the ABI implications of this change.

Reviewers: mclow.lists, dexonsmith, howard.hinnant, EricWF

Subscribers: christof, jkorous, libcxx-commits

Differential Revision: https://reviews.llvm.org/D54804

llvm-svn: 347903
2018-11-29 19:44:57 +00:00
Louis Dionne 9a494eacba [libcxx] Remove dynarray
Summary:
std::dynarray had been proposed for C++14, but it was pulled out from C++14
and there are no plans to standardize it anymore.

Reviewers: mclow.lists, EricWF

Subscribers: mgorny, christof, jkorous, dexonsmith, arphaman, libcxx-commits

Differential Revision: https://reviews.llvm.org/D54801

llvm-svn: 347783
2018-11-28 18:02:00 +00:00
Louis Dionne 2e5f0c4e16 [NFC] Fix formatting in availability documentation
llvm-svn: 347362
2018-11-20 23:07:01 +00:00
Louis Dionne 91c0a462d8 [libcxx] Mention restriction on inline namespaces in LIBCXX_ABI_NAMESPACE docs
I also kept the original "vague" documentation that saying that users are
responsible for not breaking us. This doesn't mean anything because there's
no way they can actually enforce that unless we restrict ourselves to a
specific naming scheme, but I left the documentation because it acts as a
good warning and gives us more leeway.

llvm-svn: 347052
2018-11-16 14:57:47 +00:00
Eric Fiselier 336a1a6811 Rename cxx-benchmark-unittests target and convert to LIT.
This patch renames the cxx-benchmark-unittests to check-cxx-benchmarks
and converts the target to use LIT in order to make the tests run faster
and provide better output.

In particular this runs each benchmark in a suite one by one, allowing
more parallelism while ensuring output isn't garbage with multiple threads.

Additionally, it adds the CMake flag '-DLIBCXX_BENCHMARK_TEST_ARGS=<list>'
to specify what options are passed when running the benchmarks.

llvm-svn: 346888
2018-11-14 20:38:46 +00:00
Eric Fiselier fe13c13cc2 Make libc++'s versioning namespace customizable
Summary:
This patch makes the versioning namespace libc++ uses customizable by the user using `-DLIBCXX_ABI_NAMESPACE=__foo`. 

This allows users to build custom versions of libc++ which can be linked into binaries with other libc++ versions without causing symbol conflicts or ODR issues. 

Reviewers: mclow.lists, ldionne

Reviewed By: ldionne

Subscribers: kristina, smeenai, mgorny, phosek, libcxx-commits

Differential Revision: https://reviews.llvm.org/D53879

llvm-svn: 345657
2018-10-30 21:44:53 +00:00
Louis Dionne e9d85264ac [libc++] Use exclude_from_explicit_instantiation instead of always_inline
Summary:
This commit adopts the exclude_from_explicit_instantiation attribute discussed
at [1] and reviewed in [2] in libc++ to supplant the use of __always_inline__
for visibility purposes.

This change means that users wanting to link together translation units built
with different versions of libc++'s headers into the same final linked image
MUST define the _LIBCPP_HIDE_FROM_ABI_PER_TU macro to 1 when building those
TUs. Doing otherwise will lead to ODR violations and ABI issues.

[1]: http://lists.llvm.org/pipermail/cfe-dev/2018-August/059024.html
[2]: https://reviews.llvm.org/D51789

Reviewers: rsmith, EricWF

Subscribers: dexonsmith, libcxx-commits

Differential Revision: https://reviews.llvm.org/D52405

llvm-svn: 345516
2018-10-29 17:30:04 +00:00
Louis Dionne 9b3222f613 [libc++] Make sure we can build libc++ with -fvisibility=hidden
Summary:
When building with -fvisibility=hidden, some symbols do not get exported from
libc++.dylib. This means that some entities are not explicitly given default
visibility in the source code, and that we rely on the fact -fvisibility=default
is the default. This commit explicitly gives default visibility to those
symbols to avoid being dependent on the command line flags used.

The commit also remove symbols from the dylib -- those symbols do not
actually need to be exported from the dylib and this should not be an
ABI break.

Finally, in the future, we may want to mark the whole std:: namespace as
having hidden visibility (to switch from opt-out to opt-in), in which
case the changes done in this commit will be required.

Reviewers: EricWF

Subscribers: mgorny, christof, dexonsmith, libcxx-commits

Differential Revision: https://reviews.llvm.org/D52662

llvm-svn: 345260
2018-10-25 12:13:43 +00:00
Louis Dionne 950b8e114e [libcxx] Remove custom CMake code targeting Mac OS 10.6
libc++ has dropped support for Mac OS 10.6 for a while, and we don't
have any testers set up for that OS.

This commit puts in an error message so that people can reach out to
the libc++ maintainers in case support for 10.6 is still expected (as
opposed to silently failing in weird ways). We can completely drop
support for 10.6 and remove the error message some time in the future
when we're sure that nobody is relying on it.

llvm-svn: 344576
2018-10-16 00:31:32 +00:00
Louis Dionne ea5cd3b476 [libc++] Add deprecated attributes to many deprecated components
Summary:
These deprecation warnings are opt-in: they are only enabled when the
_LIBCXX_DEPRECATION_WARNINGS macro is defined, which is not the case
by default. Note that this is a first step in the right direction, but
I wasn't able to get an exhaustive list of all deprecated components
per standard, so there's certainly stuff that's missing. The list of
components this commit marks as deprecated is:

in C++11:
- auto_ptr, auto_ptr_ref
- binder1st, binder2nd, bind1st(), bind2nd()
- pointer_to_unary_function, pointer_to_binary_function, ptr_fun()
- mem_fun_t, mem_fun1_t, const_mem_fun_t, const_mem_fun1_t, mem_fun()
- mem_fun_ref_t, mem_fun1_ref_t, const_mem_fun_ref_t, const_mem_fun1_ref_t, mem_fun_ref()

in C++14:
- random_shuffle()

in C++17:
- unary_negate, binary_negate, not1(), not2()

<rdar://problem/18168350>

Reviewers: mclow.lists, EricWF

Subscribers: christof, dexonsmith, llvm-commits

Differential Revision: https://reviews.llvm.org/D48912

llvm-svn: 342843
2018-09-23 18:35:00 +00:00
Eric Fiselier 0ef540bd51 Correct docs to reference the new libc++ lists.
We recently added libcxx-dev and libcxx-commits mailing lists.
This patch updates the libc++ documentation to correctly reference
the libc++ lists instead of the old Clang ones.

llvm-svn: 342816
2018-09-22 19:49:29 +00:00
Roman Lebedev c65d39a464 [libc++] Add _LIBCPP_ENABLE_NODISCARD and _LIBCPP_NODISCARD_EXT to allow pre-C++2a [[nodiscard]]
Summary:
The `[[nodiscard]]` attribute is intended to help users find bugs where
function return values are ignored when they shouldn't be. After C++17 the
C++ standard has started to declared such library functions as `[[nodiscard]]`.
However, this application is limited and applies only to dialects after C++17.
Users who want help diagnosing misuses of STL functions may desire a more
liberal application of `[[nodiscard]]`.

For this reason libc++ provides an extension that does just that! The
extension must be enabled by defining `_LIBCPP_ENABLE_NODISCARD`. The extended
applications of `[[nodiscard]]` takes two forms:

1. Backporting `[[nodiscard]]` to entities declared as such by the
   standard in newer dialects, but not in the present one.

2. Extended applications of `[[nodiscard]]`, at the libraries discretion,
   applied to entities never declared as such by the standard.

Users may also opt-out of additional applications `[[nodiscard]]` using
additional macros.

Applications of the first form, which backport `[[nodiscard]]` from a newer
dialect may be disabled using macros specific to the dialect it was added. For
example `_LIBCPP_DISABLE_NODISCARD_AFTER_CXX17`.

Applications of the second form, which are pure extensions, may be disabled
by defining `_LIBCPP_DISABLE_NODISCARD_EXT`.

This patch was originally written by me (Roman Lebedev),
then but then reworked by Eric Fiselier.

Reviewers: mclow.lists, thakis, EricWF

Reviewed By: thakis, EricWF

Subscribers: llvm-commits, mclow.lists, lebedev.ri, EricWF, rjmccall, Quuxplusone, cfe-commits, christof

Differential Revision: https://reviews.llvm.org/D45179

llvm-svn: 342808
2018-09-22 17:54:48 +00:00
Sylvestre Ledru 6616b4c9e9 fix some typos in the doc
llvm-svn: 342628
2018-09-20 08:05:01 +00:00
Sylvestre Ledru 0296eea49b refresh the libc++ homepage
llvm-svn: 342624
2018-09-20 07:57:31 +00:00
Hans Wennborg 462429c03d ReleaseNotes: update links to use https
llvm-svn: 341789
2018-09-10 08:57:12 +00:00
Louis Dionne 38895a0d80 [libc++] Add a link to the Release notes from the main libc++ documentation
llvm-svn: 341551
2018-09-06 15:05:43 +00:00
Louis Dionne 0fb7c99001 [libcxx] Add ReleaseNotes.rst file for release notes
llvm-svn: 341550
2018-09-06 14:46:22 +00:00
Louis Dionne 61cd687009 [libcxx] By default, do not use internal_linkage to hide symbols from the ABI
Summary:
https://reviews.llvm.org/D49240 led to symbol size problems in Chromium, and
we expect this may be the case in other projects built in debug mode too.
Instead, unless users explicitly ask for internal_linkage, we use always_inline
like we used to.

In the future, when we have a solution that allows us to drop always_inline
without falling back on internal_linkage, we can replace always_inline by
that.

Note that this commit introduces a change in contract for existing libc++
users: by default, libc++ used to guarantee that TUs built with different
versions of libc++ could be linked together. With the introduction of the
_LIBCPP_HIDE_FROM_ABI_PER_TU macro, the default behavior is that TUs built
with different libc++ versions are not guaranteed to link. This is a change
in contract but not a change in behavior, since the current implementation
still allows linking TUs built with different libc++ versions together.

Reviewers: EricWF, mclow.lists, dexonsmith, hans, rnk

Subscribers: christof, cfe-commits

Differential Revision: https://reviews.llvm.org/D50652

llvm-svn: 339874
2018-08-16 12:44:28 +00:00