This defines a new policy for removal of transitive includes.
The goal of the policy it to make it relatively easy to remove
headers when needed, but avoid breaking developers using and
vendors shipping libc++.
The method used is to guard transitive includes based on the
C++ language version. For the upcoming C++23 we can remove
headers when we want, but for other language versions we try
to keep it to a minimum.
In this code the transitive include of `<chrono>` is removed
since D128577 introduces a header cycle between `<format>`
and `<chrono>`. This cycle is indirectly required by the
Standard. Our cycle dependency tool basically is a grep based
tool, so it needs some hints to ignore cycles. With the input
of our transitive include tests we can create a better tool.
However that's out of the scope of this patch.
Note the flag `_LIBCPP_REMOVE_TRANSITIVE_INCLUDES` remains
unchanged. So users can still opt-out of transitives includes
entirely.
Reviewed By: #libc, ldionne, philnik
Differential Revision: https://reviews.llvm.org/D132284
This was discussed on Discord with the consensus that we should rename the macros.
Reviewed By: ldionne, Mordante, var-const, avogelsgesang, jloser, #libc
Spies: libcxx-commits
Differential Revision: https://reviews.llvm.org/D131498
This commit re-adds transitive includes that had been removed by
4cd04d1687, c36870c8e7, a83f4b9cda, 1458458b55, 2e2f3158c6,
and 489637e66d. This should cover almost all the includes that had
been removed since LLVM 14 and that would contribute to breaking user
code when releasing LLVM 15.
It is possible to disable the inclusion of these headers by defining
_LIBCPP_REMOVE_TRANSITIVE_INCLUDES. The intent is that vendors will
enable that macro and start fixing downstream issues immediately. We
can then remove the macro (and the transitive includes) by default in
a future release. That way, we will break users only once by removing
transitive includes in bulk instead of doing it bit by bit a every
release, which is more disruptive for users.
Note 1: The set of headers to re-add was found by re-generating the
transitive include test on a checkout of release/14.x, which
provided the list of all transitive includes we used to provide.
Note 2: Several includes of <vector>, <optional>, <array> and <unordered_map>
have been added in this commit. These transitive inclusions were
added when we implemented boyer_moore_searcher in <functional>.
Note 3: This is a best effort patch to try and resolve downstream breakage
caused since branching LLVM 14. I wasn't able to perfectly mirror
transitive includes in LLVM 14 for a few headers, so I added a
release note explaining it. To summarize, adding boyer_moore_searcher
created a bunch of circular dependencies, so we have to break
backwards compatibility in a few cases.
Differential Revision: https://reviews.llvm.org/D128661
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
This is the first step towards disentangling the debug mode and assertions
in libc++. This patch doesn't make any functional change: it simply moves
_LIBCPP_ASSERT-related stuff to its own file so as to make it clear that
libc++ assertions and the debug mode are different things. Future patches
will make it possible to enable assertions without enabling the debug
mode.
Differential Revision: https://reviews.llvm.org/D119769
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.
I just ran into a compiler error involving __bind_back and some overloads
that were being disabled with _EnableIf. I noticed that the error message
was quite bad and did not mention the reason for the overload being
excluded. Specifically, the error looked like this:
candidate template ignored: substitution failure [with _Args =
<ContiguousView>]: no member named '_EnableIfImpl' in 'std::_MetaBase<false>'
Instead, when using enable_if or enable_if_t, the compiler is clever and
can produce better diagnostics, like so:
candidate template ignored: requirement 'is_invocable_v<
std::__bind_back_op<1, std::integer_sequence<unsigned long, 0>>,
std::ranges::views::__transform::__fn &, std::tuple<PlusOne> &,
ContiguousView>' was not satisfied [with _Args = <ContiguousView>]
Basically, it tries to do a poor man's implementation of concepts, which
is already a lot better than simply complaining about substitution failure.
Hence, this commit uses enable_if_t instead of _EnableIf whenever
possible. That is both more straightforward than using the internal
helper, and also leads to better error messages in those cases.
I understand the motivation for _EnableIf's implementation was to improve
compile-time performance, however I believe striving to improve error
messages is even more important for our QOI, hence this patch. Furthermore,
it is unclear that _EnableIf actually improved compile-time performance
in any noticeable way (see discussion in the review for details).
Differential Revision: https://reviews.llvm.org/D108216
All supported compilers have supported deduction guides in C++17 for a
while, so this isn't necessary anymore.
Differential Revision: https://reviews.llvm.org/D108213
This affects only vectors with weird/malicious allocators,
the same corner case covered in D91708, but for `vector<bool>` this time.
Also ADL-proof <__tree>, which affects only sets and maps with weird/malicious
allocators where the ADL trap is in the *fancy pointer type*.
Also drive-by _VSTD:: qualification in the guts of std::bind,
std::packaged_task, std::condition_variable.
Differential Revision: https://reviews.llvm.org/D93424
I used a lot of `git grep` to find places where `std::` was being used
outside of comments and assert-messages. There were three outcomes:
- Qualified function calls, e.g. `std::move` becomes `_VSTD::move`.
This is the most common case.
- Typenames that don't need qualification, e.g. `std::allocator` becomes `allocator`.
Leaving these as `_VSTD::allocator` would also be fine, but I decided
that removing the qualification is more consistent with existing practice.
- Names that specifically need un-versioned `std::` qualification,
or that I wasn't sure about. For example, I didn't touch any code in
<atomic>, <math.h>, <new>, or any ext/ or experimental/ headers;
and I didn't touch any instances of `std::type_info`.
In some deduction guides, we were accidentally using `class Alloc = typename std::allocator<T>`,
despite `std::allocator<T>`'s type-ness not being template-dependent.
Because `std::allocator` is a qualified name, this did parse as we intended;
but what we meant was simply `class Alloc = allocator<T>`.
Differential Revision: https://reviews.llvm.org/D92250
We don't support any compiler that doesn't support variadics and rvalue
references in C++03 mode, so these workarounds can be dropped. There's
still *a lot* of cruft related to these workarounds, but I try to tackle
a bit of it here and there.
Like we do for empty std::array, make sure we have assertions in place
for obvious out-of-bounds issues in std::array when the debug mode is
enabled (which isn't by default).
The Standard is currently unimplementable. We have to pick between:
1. Not implementing constexpr support properly in std::array<T, 0>
2. Making std::array<T, 0> non-trivial even when T is trivial
3. Returning nullptr from std::array<T, 0>::begin()
Libc++ initially picked (1). In 77b9abfc8e, we started implementing constexpr properly, but lost the guarantee of triviality. Since it seems like both (1) and (2) are really important, it seems like (3) is the only viable option for libc++, after all. This is also what other implementations are doing.
This patch moves libc++ from (1) to (3).
It also:
- Improves the test coverage for the various ways of initializing std::array
- Adds tests for the triviality of std::array
- Adds tests for the aggregate-ness of std::array
Reviewed By: #libc, miscco, EricWF, zoecarver
Differential Revision: https://reviews.llvm.org/D80821
This commit adds missing support for constexpr in std::array under all
standard modes up to and including C++20. It also transforms the <array>
tests to check for constexpr-friendliness under the right standard modes.
Fixes https://llvm.org/PR40124
Fixes rdar://57522096
Supersedes https://reviews.llvm.org/D60666
Differential Revision: https://reviews.llvm.org/D80452
The use of the `&& ...` fold expression in std::array's deduction guides
recursively builds a set of binary operator expressions of depth N where
`N` is the number of elements in the initializer.
This is problematic because arrays may be large, and instantiation
depth is limited.
This patch addresses the issue by flattening the SFINAE using
the existing `__all` type trait.
Summary:
This patch implements https://wg21.link/P0325.
Please mind that at it is my first contribution to libc++, so I may have forgotten to abide to some conventions.
Reviewers: EricWF, mclow.lists, ldionne, lichray
Reviewed By: ldionne, lichray
Subscribers: lichray, dexonsmith, zoecarver, christof, ldionne, libcxx-commits
Tags: #libc
Differential Revision: https://reviews.llvm.org/D69882
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
An array T[1] isn't necessarily the same say when it's
a member of a struct. This patch addresses that problem and corrects
the tests to deal with it.
llvm-svn: 324545
Summary:
This patch fixes llvm.org/PR35491 and LWG2157 (https://cplusplus.github.io/LWG/issue2157)
The fix attempts to maintain ABI compatibility by replacing the array with a instance of `aligned_storage`.
Reviewers: mclow.lists, EricWF
Reviewed By: EricWF
Subscribers: lichray, cfe-commits
Differential Revision: https://reviews.llvm.org/D41223
llvm-svn: 324526
Revert "Fix initialization of array<const T, 0> with GCC."
Revert "Make array<const T, 0> non-CopyAssignable and make swap and fill ill-formed."
This reverts commit r324182, r324185, and r324194 which were causing issues with zero-length std::arrays.
llvm-svn: 324309
Previously, when handling zero-sized array of const objects we
used a const version of aligned_storage_t, which is not an array type.
However, GCC complains about initialization of the form: array<const T, 0> arr = {};
This patch fixes that bug by making the dummy object used to represent
the zero-sized array an array itself. This avoids GCC's complaints
about the uninitialized const member.
llvm-svn: 324194
The standard isn't exactly clear how std::array should handle zero-sized arrays
with const element types. In particular W.R.T. copy assignment, swap, and fill.
This patch takes the position that those operations should be ill-formed,
and makes changes to libc++ to make it so.
This follows up on commit r324182.
llvm-svn: 324185
Summary:
This patch fixes llvm.org/PR35491 and LWG2157 (https://cplusplus.github.io/LWG/issue2157)
The fix attempts to maintain ABI compatibility by replacing the array with a instance of `aligned_storage`.
Reviewers: mclow.lists, EricWF
Reviewed By: EricWF
Subscribers: lichray, cfe-commits
Differential Revision: https://reviews.llvm.org/D41223
llvm-svn: 324182
Summary:
This patch improves how libc++ handles min/max macros within the headers. Previously libc++ would undef them and emit a warning.
This patch changes libc++ to use `#pragma push_macro` to save the macro before undefining it, and `#pragma pop_macro` to restore the macros and the end of the header.
Reviewers: mclow.lists, bcraig, compnerd, EricWF
Reviewed By: EricWF
Subscribers: cfe-commits, krytarowski
Differential Revision: https://reviews.llvm.org/D33080
llvm-svn: 304357
