Currently, the library-internal feature test macros are only defined if
the feature is not available, and always have the prefix
`_LIBCPP_HAS_NO_`. This patch changes that, so that they are always
defined and have the prefix `_LIBCPP_HAS_` instead. This changes the
canonical use of these macros to `#if _LIBCPP_HAS_FEATURE`, which means
that using an undefined macro (e.g. due to a missing include) is
diagnosed now. While this is rather unlikely currently, a similar change
in `<__configuration/availability.h>` caught a few bugs. This also
improves readability, since it removes the double-negation of `#ifndef
_LIBCPP_HAS_NO_FEATURE`.
The current patch only touches the macros defined in `<__config>`. If
people are happy with this approach, I'll make a follow-up PR to also
change the macros defined in `<__config_site>`.
The CI has been a complete mess for the past week, and the only thing
preventing it from being back is the Clang tidy checks. Disable them (as
a total hack) to get CI back.
Many headers include `<cstddef>` just for size_t, and pulling in
additional content (e.g. the traits used for std::byte) is unnecessary.
To solve this problem, this patch splits up `<cstddef>` into
subcomponents so that headers can include only the parts that they
actually require.
This has the added benefit of making the modules build a lot stricter
with respect to IWYU, and also providing a canonical location where we
define `std::size_t` and friends (which were previously defined in
multiple headers like `<cstddef>` and `<ctime>`).
After this patch, there's still many places in the codebase where we
include `<cstddef>` when `<__cstddef/size_t.h>` would be sufficient.
This patch focuses on removing `<cstddef>` includes from __type_traits
to make these headers non-circular with `<cstddef>`. Additional
refactorings can be tackled separately.
Instead of using FOO_TEST_DEPS global variables that don't get updated
properly from subdirectories, use targets to propagate the dependencies
across directories.
The patch does several things:
- fixes module exports
- disables clang-tidy with Clang-17 due to known issues
- disabled clang-tidy on older libstdc++ versions since it lacks C++20
features used
- fixes the CMake dependency
The issue why clang-tidy was not used in the CI was the last issue; the
plugin was not a
dependency of the tests. Without a plugin the tests disable clang-tidy.
This was noticed while investigating
https://github.com/llvm/llvm-project/issues/89898
This reverts commit 4109b18ee5de1346c2b89a5c89b86bae5c8631d3.
It looks like the automatic detection has false positives. This broke
the following build https://github.com/llvm/llvm-project/pull/85262
The current selection is done in the test scripts which gives the user
no control where to find clang-tidy. The version selection itself is
hard-coded and not based on the version of clang used.
This moves the selection to configuration time and tries to find a
better match.
- Mixing the version of clang-tidy and the clang libraries causes ODR
violations. This results in practice in crashes or incorrect results.
- Mixing the version of clang-tidy and the clang binary sometimes causes
issues with supported diagnostic flags. For example, flags tested
against clang 17 may not be available in clang-tidy 16.
Currently clang-tidy 18.1 can be used, it tests against the clang
libraries version 18. This is caused by the new LLVM version numbering
scheme.
The new selection tries to match the clang version or the version of the
HEAD and the last 3 releases. (During the release period libc++ supports
4 versions instead of the typical 3 versions.)
As suggested in #71438 we should use
export import std;
in the std.compat module.
Using this exports some named declarations from functions and records,
adding them to the global namespace. Clang correctly does not export
these and it's an issue in the declaration filtering. Declarations in
function or record context are not considered a global named
declaration.
As suggested in #71438 we should use
export import std;
in the std.compat module.
Testing this locally failed when building with the clang-tidy-17 plugin.
The std module was considered corrupt in the test
libcxx/test/libcxx/module_std_compat.gen.py
however the test
libcxx/test/libcxx/module_std.gen.py
passed. Both test generated identical std.pcm files. Using the
clang-tidy-18 plugin solves the issue.
The fix changes the way the validation script determines the qualified
name of a declaration. Inline namespaces without a reserved name are now
always part of the name. The Clang code only does this when the names
are ambigious. This method is often used for the operator""foo for UDLs.
Adjusted the newly flagged issue and removed a work-around in the test
code that is no longer required.
Fixes https://github.com/llvm/llvm-project/issues/72427
This adds the std.compat module. The patch contains a bit of refactoring
to avoid code duplication between the std and std.compat module.
Implements parts of
- P2465R3 Standard Library Modules std and std.compat
Fixes 2 error messages from the module test clang-tidy plugin.
- an issue where an empty filename can't be used in an AST matcher
- an issue where no filename is valid when testing the std module cppm
This reduces the output of the test, making it easier to find the real
error when the test fails.
Reviewed By: philnik, #libc
Differential Revision: https://reviews.llvm.org/D157741
This patch is based on the suggestion by @ChuanqiXu on discourse
(https://discourse.llvm.org/t/alternatives-to-the-implementation-of-std-modules/71958)
Instead of making a module partition per header every header gets an inc
file which contains the exports per header. The std module then includes
all public headers and these inc files. The one file per header is
useful for testing purposes. The CI tests whether the exports of a
header's module partition matches the "public" named declarations in the
header. With one file per header this can still be done.
The patch improves compilation time of files using "import std;" and the
size of the std module.
A comparision of the compilation speed using a libc++ test
build/bin/llvm-lit -a -Dstd=c++23 -Denable_modules=std libcxx/test/std/modules/std.pass.cpp
Which boils down to
import std;
int main(int, char**) {
std::println("Hello modular world");
return 0;
}
and has -ftime-report enabled
Before
===-------------------------------------------------------------------------===
Clang front-end time report
===-------------------------------------------------------------------------===
Total Execution Time: 8.6585 seconds (8.6619 wall clock)
---User Time--- --System Time-- --User+System-- ---Wall Time--- --- Name ---
4.5041 ( 57.2%) 0.4264 ( 54.4%) 4.9305 ( 56.9%) 4.9331 ( 57.0%) Clang front-end timer
3.2037 ( 40.7%) 0.2408 ( 30.7%) 3.4445 ( 39.8%) 3.4452 ( 39.8%) Reading modules
0.1665 ( 2.1%) 0.1170 ( 14.9%) 0.2835 ( 3.3%) 0.2837 ( 3.3%) Loading .../build/test/__config_module__/CMakeFiles/std.dir/std.pcm
7.8744 (100.0%) 0.7842 (100.0%) 8.6585 (100.0%) 8.6619 (100.0%) Total
After
===-------------------------------------------------------------------------===
Clang front-end time report
===-------------------------------------------------------------------------===
Total Execution Time: 1.2420 seconds (1.2423 wall clock)
---User Time--- --System Time-- --User+System-- ---Wall Time--- --- Name ---
0.8892 ( 84.6%) 0.1698 ( 88.8%) 1.0590 ( 85.3%) 1.0590 ( 85.2%) Clang front-end timer
0.1533 ( 14.6%) 0.0168 ( 8.8%) 0.1701 ( 13.7%) 0.1704 ( 13.7%) Reading modules
0.0082 ( 0.8%) 0.0047 ( 2.5%) 0.0129 ( 1.0%) 0.0129 ( 1.0%) Loading .../build/test/__config_module__/CMakeFiles/std.dir/std.pcm
1.0507 (100.0%) 0.1913 (100.0%) 1.2420 (100.0%) 1.2423 (100.0%) Total
Using "include <print>" instead of "import module;"
===-------------------------------------------------------------------------===
Clang front-end time report
===-------------------------------------------------------------------------===
Total Execution Time: 2.1507 seconds (2.1517 wall clock)
---User Time--- --System Time-- --User+System-- ---Wall Time--- --- Name ---
1.9714 (100.0%) 0.1793 (100.0%) 2.1507 (100.0%) 2.1517 (100.0%) Clang front-end timer
1.9714 (100.0%) 0.1793 (100.0%) 2.1507 (100.0%) 2.1517 (100.0%) Total
It's possible to use the std module in external projects
(https://libcxx.llvm.org/Modules.html#using-in-external-projects)
Tested this with a private project to validate the size of the generated files:
Before
$ du -sch std-*
448M std-build
508K std-src
120K std-subbuild
449M total
After
$ du -sch std-*
29M std-build
1004K std-src
132K std-subbuild
30M total
Reviewed By: ldionne, #libc
Differential Revision: https://reviews.llvm.org/D156907
Adds tests to guard against the issue solved in D156592.
Depends on D156592
Reviewed By: ChuanqiXu, #libc, philnik
Differential Revision: https://reviews.llvm.org/D156594
The first issue was found by @ldionne, upon further investigation there
were more duplicates. This removes the duplicates and updates the
clang-tidy test to detect duplicates.
Reviewed By: ldionne, #libc
Differential Revision: https://reviews.llvm.org/D154723
The patch is based on D144994.
D151030 added the module definitions for the module std.
This patch wires in the module and enables the basic testing.
Some notable features are missing:
- There is no test that libc++ can be fully imported as a module.
- This lacks the parts for the std.compat module.
- The module is not shipped with libc++.
Implements parts of
- P2465R3 Standard Library Modules std and std.compat
Reviewed By: ldionne, aaronmondal, #libc
Differential Revision: https://reviews.llvm.org/D151814
Module require Clang 17, since Clang 16 requires the magic # __FILE__
line. Therefore, if available, use clang-tidy 17 too. This change should
be reverted after LLVM 17 is released.
Reviewed By: #libc, ldionne
Differential Revision: https://reviews.llvm.org/D149455
When using with clang-tidy 17 Node.getAttrName() sometimes returns a
nullptr. This caused segfaults in the CI.
Reviewed By: philnik, #libc
Differential Revision: https://reviews.llvm.org/D151224
Clang has been updated to support C++26, this adds the same support for
libc++. At the moment C++23 and C++26 are identical. During the next
plenary in June the first C++26 papers will be voted on.
Note like Clang this patch uses C++26 is the internal part and C++2c in
the user visible part.
Depends on D150795
Reviewed By: ldionne, #libc
Differential Revision: https://reviews.llvm.org/D151026
D149553 changes the name of the LangOptions member. This change allows
libc++ to work with either name.
Reviewed By: philnik, #libc
Differential Revision: https://reviews.llvm.org/D149554
We already have a clang-tidy check for making sure that `_LIBCPP_HIDE_FROM_ABI` is on free functions. This patch extends this to class members. The places where we don't check for `_LIBCPP_HIDE_FROM_ABI` are classes for which we have an instantiation in the library.
Reviewed By: ldionne, Mordante, #libc
Spies: jplehr, mikhail.ramalho, sstefan1, libcxx-commits, krytarowski, miyuki, smeenai
Differential Revision: https://reviews.llvm.org/D142332
This adds a list of attributes which can be pretty to be able to reject attributes which were introduced in a later C++ standard.
Fixes#61196
Reviewed By: Mordante, #libc
Spies: mikhail.ramalho, jdoerfert, libcxx-commits
Differential Revision: https://reviews.llvm.org/D145508
This check flags code which uses `_LIBCPP_STD_VER` the wrong way, or tries to use `__cplusplus`. It flags cases where we use `_LIBCPP_STD_VER >` instead of `_LIBCPP_STD_VER >=` and where wrong values are used (e.g. `_LIBCPP_STD_VER >= 24`).
Reviewed By: ldionne, #libc
Spies: libcxx-commits
Differential Revision: https://reviews.llvm.org/D144261
The current clang-tidy settings work in the CI but not on all systems
outside the CI.
- The range 16...17 doesn't work when only clang-17 is installed.
- Running CMake a second time will fail.
This addresses these issues.
Reviewed By: philnik, #libc
Differential Revision: https://reviews.llvm.org/D144785
This allows compiling the clang-tidy checks when you only have ToT clang
Reviewed By: ldionne, #libc
Spies: libcxx-commits
Differential Revision: https://reviews.llvm.org/D142973
While it's not necessary to qualify calls to `declval` it makes error messages very crypric if the declaration isn't reachable anymore
For example:
```
/home/nikolask/llvm-projects/libcxx/build/include/c++/v1/__chrono/duration.h:53:66: error: no type named 'type' in 'std::common_type<long, long>'
typedef chrono::duration<typename common_type<_Rep1, _Rep2>::type,
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~^~~~
/home/nikolask/llvm-projects/libcxx/build/include/c++/v1/__type_traits/common_type.h:107:14: note: in instantiation of template class 'std::common_type<std::chrono::duration<long, std::ratio<3600, 1>>, std::chrono::duration<long, std::ratio<3600, 1>>>' requested here
: public common_type<_Tp, _Tp> {};
^
/home/nikolask/llvm-projects/libcxx/build/include/c++/v1/__chrono/duration.h:279:58: note: in instantiation of template class 'std::common_type<std::chrono::duration<long, std::ratio<3600, 1>>>' requested here
_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR typename common_type<duration>::type operator+() const {return typename common_type<duration>::type(*this);}
^
/home/nikolask/llvm-projects/libcxx/build/include/c++/v1/__chrono/duration.h:308:54: note: in instantiation of template class 'std::chrono::duration<long, std::ratio<3600, 1>>' requested here
typedef duration< int, ratio_multiply<ratio<24>, hours::period>> days;
^
/home/nikolask/llvm-projects/libcxx/build/include/c++/v1/__chrono/duration.h:280:81: error: no type named 'type' in 'std::common_type<std::chrono::duration<long, std::ratio<3600, 1>>>'
_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR typename common_type<duration>::type operator-() const {return typename common_type<duration>::type(-__rep_);}
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~^~~~
/home/nikolask/llvm-projects/libcxx/build/include/c++/v1/__chrono/duration.h:308:54: note: in instantiation of template class 'std::chrono::duration<long, std::ratio<3600, 1>>' requested here
typedef duration< int, ratio_multiply<ratio<24>, hours::period>> days;
^
/home/nikolask/llvm-projects/libcxx/build/include/c++/v1/__chrono/duration.h:53:66: error: no type named 'type' in 'std::common_type<int, int>'
typedef chrono::duration<typename common_type<_Rep1, _Rep2>::type,
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~^~~~
/home/nikolask/llvm-projects/libcxx/build/include/c++/v1/__type_traits/common_type.h:107:14: note: in instantiation of template class 'std::common_type<std::chrono::duration<int, std::ratio<86400, 1>>, std::chrono::duration<int, std::ratio<86400, 1>>>' requested here
: public common_type<_Tp, _Tp> {};
^
/home/nikolask/llvm-projects/libcxx/build/include/c++/v1/__chrono/duration.h:279:58: note: in instantiation of template class 'std::common_type<std::chrono::duration<int, std::ratio<86400, 1>>>' requested here
_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR typename common_type<duration>::type operator+() const {return typename common_type<duration>::type(*this);}
^
/home/nikolask/llvm-projects/libcxx/build/include/c++/v1/__chrono/duration.h:309:55: note: in instantiation of template class 'std::chrono::duration<int, std::ratio<86400, 1>>' requested here
typedef duration< int, ratio_multiply<ratio<7>, days::period>> weeks;
^
19 similar errors omitted
```
changes with qualification added to:
```
While building module 'std' imported from /home/nikolask/llvm-projects/libcxx/libcxx/test/std/utilities/meta/meta.trans/meta.trans.other/common_type.pass.cpp:13:
In file included from <module-includes>:17:
In file included from /home/nikolask/llvm-projects/libcxx/build/include/c++/v1/math.h:309:
In file included from /home/nikolask/llvm-projects/libcxx/build/include/c++/v1/limits:107:
In file included from /home/nikolask/llvm-projects/libcxx/build/include/c++/v1/type_traits:432:
In file included from /home/nikolask/llvm-projects/libcxx/build/include/c++/v1/__type_traits/common_reference.h:13:
/home/nikolask/llvm-projects/libcxx/build/include/c++/v1/__type_traits/common_type.h:28:43: error: declaration of 'declval' must be imported from module 'std.utility.__utility.declval' before it is required
using __cond_type = decltype(false ? std::declval<_Tp>() : std::declval<_Up>());
^
/home/nikolask/llvm-projects/libcxx/build/include/c++/v1/__utility/declval.h:30:34: note: declaration here is not visible
decltype(std::__declval<_Tp>(0)) declval() _NOEXCEPT;
^
/home/nikolask/llvm-projects/libcxx/libcxx/test/std/utilities/meta/meta.trans/meta.trans.other/common_type.pass.cpp:13:10: fatal error: could not build module 'std'
#include <functional>
~~~~~~~~^
2 errors generated.
```
Reviewed By: ldionne, Mordante, #libc
Spies: libcxx-commits
Differential Revision: https://reviews.llvm.org/D130854
