Commit Graph

14 Commits

Author SHA1 Message Date
Louis Dionne eb8650a757 [runtimes][NFC] Remove filenames at the top of the license notice
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.
2021-11-17 16:30:52 -05:00
Louis Dionne c137a0754c [libc++] Remove _LIBCPP_HAS_NO_LONG_LONG in favour of using_if_exists
_LIBCPP_HAS_NO_LONG_LONG was only defined on FreeBSD. Instead, use the
using_if_exists attribute to skip over declarations that are not available
on the base system. Note that there's an annoying limitation that we can't
conditionally define a function based on whether the base system provides
a function, so for example we still need preprocessor logic to define the
abs() and div() overloads.

Differential Revision: https://reviews.llvm.org/D108630
2021-09-03 14:26:59 -04:00
Louis Dionne 4cd6ca102a [libc++] NFC: Normalize `#endif //` comment indentation 2021-04-20 12:03:32 -04:00
jasonliu f3d7536b24 [libc++] Fix abs and div overload issue for compilers on AIX
Summary:
AIX system's stdlib.h provide different overload of abs and div
depending on compiler versions.

For example, std::div(long, long) and std::abs(long) are not available
from OS's stdlib.h when building with clang, but they are available
when building with xlclang compiler.

Therefore, we need to provide those extra overloads in libc++'s stdlib.h
when OS's stdlib.h does not.

Differential Revision: https://reviews.llvm.org/D99767
2021-04-09 14:47:13 +00:00
Eric Fiselier c490c5e81a Reland [libc++] Move abs and div into stdlib.h to fix header cycle.
This commit should will break libc++ without local submodule visibility, but
the LLVM+modules bots are now all using this mode. Before the Green Dragon
LLDB bot was failing to compile with a libc++ built with this commit as LSV
was disabled on macOS.

Original summary:

libc++ is careful to not fracture overload sets. When one overload
is visible to a user, all of them should be. Anything less causes
subtle bugs and ODR violations.

Previously, in order to support ::abs and ::div being supplied by
both <cmath> and <cstdlib> we had to do awful things that make
<math.h> and <stdlib.h> have header cycles and be non-modular.
This really breaks with modules.

Specifically the problem was that in C++ ::abs introduces overloads
for floating point numbers, these overloads forward to ::fabs,
which are defined in math.h. Therefore ::abs needed to be in math.h
too. But this required stdlib.h to include math.h and math.h to
include stdlib.h.

To avoid these problems the definitions have been moved to stddef.h
(which math includes), and the floating point overloads of ::abs
have been changed to call __builtin_fabs, which both Clang and GCC
support.
2020-05-08 21:52:27 +02:00
Raphael Isemann bd2965c9db Revert "Recommit [libc++] Move abs and div into stdlib.h to fix header cycle."
It seems that D74892 still hasn't fixed the issue on the bot. Currently
investigating the bot breakage and meanwhile (again) reverting this...
2020-04-28 20:23:22 +02:00
Eric Fiselier d0846b432c Recommit [libc++] Move abs and div into stdlib.h to fix header cycle.
This relands this commit as it broke the LLDB bot the first time it landed.
See also the discussion on https://reviews.llvm.org/rG82b47b2978405f802a33b00d046e6f18ef6a47be

Since D74892 this code should now also work on macOS.

Original description:

libc++ is careful to not fracture overload sets. When one overload
is visible to a user, all of them should be. Anything less causes
subtle bugs and ODR violations.

Previously, in order to support ::abs and ::div being supplied by
both <cmath> and <cstdlib> we had to do awful things that make
<math.h> and <stdlib.h> have header cycles and be non-modular.
This really breaks with modules.

Specifically the problem was that in C++ ::abs introduces overloads
for floating point numbers, these overloads forward to ::fabs,
which are defined in math.h. Therefore ::abs needed to be in math.h
too. But this required stdlib.h to include math.h and math.h to
include stdlib.h.

To avoid these problems the definitions have been moved to stddef.h
(which math includes), and the floating point overloads of ::abs
have been changed to call __builtin_fabs, which both Clang and GCC
support.
2020-04-28 15:42:36 +02:00
Raphael Isemann 23368bee15 Revert "[libc++] Move abs and div into stdlib.h to fix header cycle."
This reverts commit 82b47b2978.

This broke Clang and LLDB module builds without -fmodules-local-submodule-visbility.
I'll revert this for now until we have a fix and reland once Clang
can properly handle this code.

See also the discussion in https://reviews.llvm.org/rG82b47b2978405f802a33b00d046e6f18ef6a47be
2020-02-17 17:59:08 +01:00
Eric Fiselier 82b47b2978 [libc++] Move abs and div into stdlib.h to fix header cycle.
libc++ is careful to not fracture overload sets. When one overload
is visible to a user, all of them should be. Anything less causes
subtle bugs and ODR violations.

Previously, in order to support ::abs and ::div being supplied by
both <cmath> and <cstdlib> we had to do awful things that make
<math.h> and <stdlib.h> have header cycles and be non-modular.
This really breaks with modules.

Specifically the problem was that in C++ ::abs introduces overloads
for floating point numbers, these overloads forward to ::fabs,
which are defined in math.h. Therefore ::abs needed to be in math.h
too. But this required stdlib.h to include math.h and math.h to
include stdlib.h.

To avoid these problems the definitions have been moved to stddef.h
(which math includes), and the floating point overloads of ::abs
have been changed to call __builtin_fabs, which both Clang and GCC
support.
2020-02-15 18:55:07 -05:00
Eric Fiselier 1670772adc Fix implementation of ::abs and std::abs LWG 2192.
Summary:
All overloads of `::abs` and `std::abs` must be present in both `<cmath>` and `<cstdlib>`. This is problematic to implement because C defines `fabs` in `math.h` and `labs` in `stdlib.h`. This introduces a circular dependency between the two headers. 

This patch implements that requirement by moving `abs` into `math.h` and making `stdlib.h` include `math.h`. In order to get the underlying C declarations from the "real" `stdlib.h` inside our `math.h` we need some trickery. Specifically we need to make `stdlib.h` include next itself.

Suggestions for a cleaner implementation are welcome.

Reviewers: mclow.lists, ldionne

Reviewed By: ldionne

Subscribers: krytarowski, fedor.sergeev, dexonsmith, jdoerfert, jsji, libcxx-commits

Differential Revision: https://reviews.llvm.org/D60097

llvm-svn: 359020
2019-04-23 18:01:58 +00:00
Chandler Carruth 57b08b0944 Update more file headers across all of the LLVM projects in the monorepo
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
2019-01-19 10:56:40 +00:00
Eric Fiselier 5d50aa3204 [libc++] Refactor Windows support headers.
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
2017-05-10 20:57:45 +00:00
Eric Fiselier 60506cbcd4 Cleanup foo.h headers and __config to work in C
llvm-svn: 252274
2015-11-06 06:30:12 +00:00
Richard Smith a51c8eee6e Split <stdlib.h> out of <cstdlib>.
llvm-svn: 249800
2015-10-09 01:41:45 +00:00