Commit Graph

32 Commits

Author SHA1 Message Date
Eric Fiselier
f68c6d52a1 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

git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@363219 91177308-0d34-0410-b5e6-96231b3b80d8
2019-06-13 00:37:25 +00:00
Eric Fiselier
d011bdc437 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.

git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@363110 91177308-0d34-0410-b5e6-96231b3b80d8
2019-06-11 22:53:49 +00:00
Louis Dionne
4211451486 [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

git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@363072 91177308-0d34-0410-b5e6-96231b3b80d8
2019-06-11 14:48:40 +00:00
J. Ryan Stinnett
571342b54b [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

git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@362113 91177308-0d34-0410-b5e6-96231b3b80d8
2019-05-30 16:46:22 +00:00
Louis Dionne
3af5f5e110 [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

git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@356587 91177308-0d34-0410-b5e6-96231b3b80d8
2019-03-20 18:16:24 +00:00
James Y Knight
e0324cb307 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

git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@352514 91177308-0d34-0410-b5e6-96231b3b80d8
2019-01-29 16:37:27 +00:00
Eric Fiselier
a8b9f59e8c 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

git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@351286 91177308-0d34-0410-b5e6-96231b3b80d8
2019-01-16 01:37:43 +00:00
Eric Fiselier
3cea452823 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.

git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@342816 91177308-0d34-0410-b5e6-96231b3b80d8
2018-09-22 19:49:29 +00:00
Sylvestre Ledru
ac2b5703bb refresh the libc++ homepage
git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@342624 91177308-0d34-0410-b5e6-96231b3b80d8
2018-09-20 07:57:31 +00:00
Louis Dionne
6969dc114e [libc++] Add a link to the Release notes from the main libc++ documentation
git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@341551 91177308-0d34-0410-b5e6-96231b3b80d8
2018-09-06 15:05:43 +00:00
Eric Fiselier
88dfb6d532 Add design docs for upcoming file_time_type change.
In upcoming changes to filesystem I plan to change file_time_type
to use __int128_t as its underlying representation, in order
to allow it to have a range and resolution at least that of
the timespec struct.

There was some pushback against this decision, so I drafted
a document explaining the problems, potential solutions, and
the rational for the decision.

However, it's probably easier to let people read the generated
HTML rather than the raw restructured text. For this reason
I'm commiting the design documents before hand, so they can
be available during any subsequent discussion or code review.

git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@337880 91177308-0d34-0410-b5e6-96231b3b80d8
2018-07-25 02:53:53 +00:00
Mehdi Amini
907c1196a7 Add markup for libc++ dylib availability
Libc++ is used as a system library on macOS and iOS (amongst others). In order
for users to be able to compile a binary that is intended to be deployed to an
older version of the platform, clang provides the
availability attribute <https://clang.llvm.org/docs/AttributeReference.html#availability>_
that can be placed on declarations to describe the lifecycle of a symbol in the
library.

See docs/DesignDocs/AvailabilityMarkup.rst for more information.

Differential Revision: https://reviews.llvm.org/D31739

git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@302172 91177308-0d34-0410-b5e6-96231b3b80d8
2017-05-04 17:08:54 +00:00
Eric Fiselier
b8577430ea Update Appveyor bot link to point to new llvm-mirror Appveyor account
git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@302128 91177308-0d34-0410-b5e6-96231b3b80d8
2017-05-04 07:40:23 +00:00
Eric Fiselier
3c51b64ddc update buildbot doc to link to the new Appveyor builders
git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@302116 91177308-0d34-0410-b5e6-96231b3b80d8
2017-05-04 05:58:59 +00:00
Eric Fiselier
b7fd0be370 Update all bug URL's to point to https://bugs.llvm.org/...
git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@295434 91177308-0d34-0410-b5e6-96231b3b80d8
2017-02-17 08:37:03 +00:00
Mehdi Amini
8a032c59d0 [libcxx] Mentions "targeting C++11 and above" instead of "targeting C++11" in the doc
git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@293071 91177308-0d34-0410-b5e6-96231b3b80d8
2017-01-25 17:00:30 +00:00
Eric Fiselier
66134e8a5f [libc++] Cleanup and document <__threading_support>
Summary:
This patch attempts to clean up the macro configuration mess in `<__threading_support>`, specifically the mess involving external threading variants. Additionally this patch adds design documentation for `<__threading_support>` and the configuration macros it uses.

The primary change in this patch is separating the idea of an "external API" provided by `<__external_threading>` and the idea of having an external threading library. Now `_LIBCPP_HAS_THREAD_API_EXTERNAL` means that libc++ should use `<__external_threading>` and that the header is expected to exist.  Additionally the new macro `_LIBCPP_HAS_THREAD_LIBRARY_EXTERNAL` is now used to configure for using an "external library"  with the default threading API.

Reviewers: compnerd, rmaprath

Subscribers: smeenai, cfe-commits, mgorny

Differential Revision: https://reviews.llvm.org/D28316

git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@291275 91177308-0d34-0410-b5e6-96231b3b80d8
2017-01-06 20:05:40 +00:00
Eric Fiselier
ce34512d2f Remove dead debug_mode doc link
git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@290659 91177308-0d34-0410-b5e6-96231b3b80d8
2016-12-28 06:21:09 +00:00
Eric Fiselier
01eb99ac7b Implement a throwing version of _LIBCPP_ASSERT.
This patch implements changes to allow _LIBCPP_ASSERT to throw on failure
instead of aborting. The main changes needed to do this are:

1. Change _LIBCPP_ASSERT to call a handler via a replacable function pointer
   instead of calling abort directly. Additionally this patch implements two
   handler functions, one which aborts and another that throws an exception.

2. Add _NOEXCEPT_DEBUG macro for disabling noexcept spec on function which
   contain _LIBCPP_ASSERT. This is required in order to prevent assertion
   failures throwing through a noexcept function. This macro has no effect
   unless _LIBCPP_DEBUG_USE_EXCEPTIONS is defined.

Having a non-aborting _LIBCPP_ASSERT is very important to allow sane testing of
debug mode. Currently we can only have one test case per file, since the test
case will cause the program to abort. Testing debug mode this way would require
thousands of test files, most of which would be 95% boiler plate. I don't think
this is a feasible strategy. Fortunately using a throwing debug handler solves
these issues.

Additionally this patch rewrites the documentation for debug mode.

git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@290651 91177308-0d34-0410-b5e6-96231b3b80d8
2016-12-28 04:58:52 +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
Eric Fiselier
b9aebae3dc Add links to libc++ code coverage and builders
git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@250361 91177308-0d34-0410-b5e6-96231b3b80d8
2015-10-15 03:27:02 +00:00
Eric Fiselier
a6622799b4 Use __config_site when building libc++. Also cleanup ABI versioning doc
git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@250261 91177308-0d34-0410-b5e6-96231b3b80d8
2015-10-14 00:22:05 +00:00
Eric Fiselier
73ffc78616 [libcxx] Capture configuration information when installing the libc++ headers
Summary:
Hi all,

This patch is a successor to D11963. However it has changed dramatically and I felt it would be best to start a new review thread.

Please read the design documentation added in this patch for a description of how it works.

Reviewers: mclow.lists, danalbert, jroelofs, EricWF

Subscribers: vkalintiris, rnk, ed, espositofulvio, asl, eugenis, cfe-commits

Differential Revision: http://reviews.llvm.org/D13407

git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@250235 91177308-0d34-0410-b5e6-96231b3b80d8
2015-10-13 22:12:02 +00:00
Eric Fiselier
5d514c01f5 Fix another bad link in the new docs
git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@246951 91177308-0d34-0410-b5e6-96231b3b80d8
2015-09-06 23:22:02 +00:00
Eric Fiselier
7ec94be3df Try to fix links for libcxx.llvm.org/docs again.
git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@246950 91177308-0d34-0410-b5e6-96231b3b80d8
2015-09-06 23:09:54 +00:00
Eric Fiselier
82c5745451 Try and fix links again. Seems to be a sphinx version issue.
git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@246915 91177308-0d34-0410-b5e6-96231b3b80d8
2015-09-05 07:20:53 +00:00
Eric Fiselier
4b5169ad0b Try and fix broken bugzilla link
git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@246914 91177308-0d34-0410-b5e6-96231b3b80d8
2015-09-05 06:57:29 +00:00
Eric Fiselier
1aa96e8679 Cleanup new documentation index and transfer more information from www/index.html
git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@246913 91177308-0d34-0410-b5e6-96231b3b80d8
2015-09-05 06:50:03 +00:00
Eric Fiselier
bf54da76b9 Test commit for builder
git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@246910 91177308-0d34-0410-b5e6-96231b3b80d8
2015-09-05 05:29:23 +00:00
Eric Fiselier
46f9f326cf Try building docs again.
git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@246906 91177308-0d34-0410-b5e6-96231b3b80d8
2015-09-05 01:32:48 +00:00
Eric Fiselier
6e5b234c63 Test commit for sphinx docs try2
git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@246895 91177308-0d34-0410-b5e6-96231b3b80d8
2015-09-04 23:19:11 +00:00
Eric Fiselier
b9f425a434 [libcxx] Add new Sphinx documentation
Summary:
This patch adds Sphinx based documentation to libc++. The goal is to make it easier to write documentation for libc++ since writing new documentation in HTML is cumbersome. This patch rewrites the main page for libc++ along with the instructions for using, building and testing libc++. 

The built documentation can be found and reviewed here: http://efcs.ca/libcxx-docs

In order to build the sphinx documentation you need to specify the cmake options `-DLLVM_ENABLE_SPHINX=ON -DLIBCXX_INCLUDE_DOCS=ON`. This will add the makefile rule `docs-libcxx-html`.

Reviewers: chandlerc, mclow.lists, danalbert, jroelofs

Subscribers: silvas, cfe-commits

Differential Revision: http://reviews.llvm.org/D12129

git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@245788 91177308-0d34-0410-b5e6-96231b3b80d8
2015-08-22 19:40:49 +00:00