This patch implements the forwarding to frozen C++03 headers as
discussed in
https://discourse.llvm.org/t/rfc-freezing-c-03-headers-in-libc. In the
RFC, we initially proposed selecting the right headers from the Clang
driver, however consensus seemed to steer towards handling this in the
library itself. This patch implements that direction.
At a high level, the changes basically amount to making each public
header look like this:
```
// inside <vector>
#ifdef _LIBCPP_CXX03_LANG
# include <__cxx03/vector>
#else
// normal <vector> content
#endif
```
In most cases, public headers are simple umbrella headers so there isn't
much code in the #else branch. In other cases, the #else branch contains
the actual implementation of the header.
This change has a long history. It was first attempted naively in
https://reviews.llvm.org/D131425, which didn't work because we broke the
ability for code to include e.g. <stdio.h> multiple times and get
different definitions based on the pre-defined macros.
However, in #86843 we managed to simplify <stddef.h> by including the
underlying system header outside of any include guards, which worked.
This patch applies the same simplification we did to <stddef.h> to the
other headers that currently mention __need_FOO macros explicitly.
This patch runs clang-format on all of libcxx/include and libcxx/src, in
accordance with the RFC discussed at [1]. Follow-up patches will format
the benchmarks, the test suite and remaining parts of the code. I'm
splitting this one into its own patch so the diff is a bit easier to
review.
This patch was generated with:
find libcxx/include libcxx/src -type f \
| grep -v 'module.modulemap.in' \
| grep -v 'CMakeLists.txt' \
| grep -v 'README.txt' \
| grep -v 'libcxx.imp' \
| grep -v '__config_site.in' \
| xargs clang-format -i
A Git merge driver is available in libcxx/utils/clang-format-merge-driver.sh
to help resolve merge and rebase issues across these formatting changes.
[1]: https://discourse.llvm.org/t/rfc-clang-formatting-all-of-libc-once-and-for-all
Libc++ tried accomodating systems that need to be able to define various
__need_FOO macros before including C library headers, however it does not
appear to be needed anymore in most cases. Indeed, glibc used to use that
system to conditionally provide definitions, however almost all instances
of these macros have been removed from glibc years ago.
I think the next step would be to also fix Clang's own builtin headers
to stop needing these macros.
Differential Revision: https://reviews.llvm.org/D131425
Some platforms don't provide all C library headers. In practice, libc++
only requires a few C library headers to exist, and only a few functions
on those headers. Missing functions that libc++ doesn't need for its own
implementation are handled properly by the using_if_exists attribute,
however a missing header is currently a hard error when we try to
do #include_next.
This patch should make libc++ more flexible on platforms that do not
provide C headers that libc++ doesn't actually require for its own
implementation. The only downside is that it may move some errors from
the #include_next point to later in the compilation if we actually try
to use something that isn't provided, which could be somewhat confusing.
However, these errors should be caught by folks trying to port libc++
over to a new platform (when running the libc++ test suite), not by end
users.
NOTE: This is a reapplicaton of 226409, which was reverted in 674729813
because it broke the build. The issue has now been fixed with
https://reviews.llvm.org/D138062.
Differential Revision: https://reviews.llvm.org/D136683
Some platforms don't provide all C library headers. In practice, libc++
only requires a few C library headers to exist, and only a few functions
on those headers. Missing functions that libc++ doesn't need for its own
implementation are handled properly by the using_if_exists attribute,
however a missing header is currently a hard error when we try to
do #include_next.
This patch should make libc++ more flexible on platforms that do not
provide C headers that libc++ doesn't actually require for its own
implementation. The only downside is that it may move some errors from
the #include_next point to later in the compilation if we actually try
to use something that isn't provided, which could be somewhat confusing.
However, these errors should be caught by folks trying to port libc++
over to a new platform (when running the libc++ test suite), not by end
users.
Differential Revision: https://reviews.llvm.org/D136683
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.
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
The language standard does not define a function with this name,
so it is part of the user's namespace. This change fixes a duplicate
symbol error that occurs when a user attempts to define a function
with this name.
Differential Revision: https://reviews.llvm.org/D42405
llvm-svn: 323237
Summary:
This patch refactors and tries to remove as much of the Windows support headers as possible. This is needed because they currently introduce super weird include cycles and dependencies between STL and libc headers.
The changes in this patch are:
* remove `support/win32/support.h` completely. The required parts have either been moved into `support/win32/msvc_support.h` (for `MSVC` only helpers not needed by Clang), or directly into their respective `foo.h` headers.
* Combine `locale_win32.h` and `locale_mgmt_win32.h` into a single headers, this header should only be included within `__locale` or `locale` to avoid include cycles.
* Remove the unneeded parts of `limits_win32.h` and re-name it to `limits_msvc_win32.h` since it's only needed by Clang.
I've tested this patch using Clang on Windows, but I suspect it might technically regress our non-existent support for MSVC. Is somebody able to double check?
This refactor is needed to support upcoming fixes to `<locale>` on Windows.
Reviewers: bcraig, rmaprath, compnerd, EricWF
Reviewed By: EricWF
Subscribers: majnemer, cfe-commits
Differential Revision: https://reviews.llvm.org/D32988
llvm-svn: 302727
