23 Commits

Author SHA1 Message Date
Shubh Pachchigar
98e8ef2273
[libc] Fix broken links in libc (#145199)
This PR fixes broken links in all files describing libc usage modes.
Please let me know if there are any other places that need updating.

---------

Co-authored-by: shubhp@perlmutter <shubhp@perlmutter.com>
2025-06-23 15:51:43 -07:00
lntue
d87eea35fa
[libc] Move libc_errno.h to libc/src/__support and make LIBC_ERRNO_MODE_SYSTEM to be header-only. (#143187)
This is the first step in preparation for:
https://discourse.llvm.org/t/rfc-make-clang-builtin-math-functions-constexpr-with-llvm-libc-to-support-c-23-constexpr-math-functions/86450
2025-06-11 16:25:27 -04:00
Kazu Hirata
c5229e92ce
[libc] Fix typos in documentation (#139852) 2025-05-14 07:14:43 -07:00
PiJoules
665efe8967
[libc] Add LIBC_NAMESPACE_DECL macro (#97109)
This defines to LIBC_NAMESPACE with
`__attribute__((visibility("hidden")))` so all the symbols under it have
hidden visibility. This new macro should be used when declaring a new
namespace that will have internal functions/globals and LIBC_NAMESPACE
should be used as a means of accessing functions/globals declared within
LIBC_NAMESPACE_DECL.
2024-07-03 17:02:57 -07:00
Nick Desaulniers
0336116ed4
[libc][docs] codify Policy on Assembler Sources (#88185)
It would be helpful in future code reviews to document a policy with
regards to
where and when Assembler sources are appropriate. That way when
reviewers point
out infractions, they can point to this written policy, which may help
contributors understand that it's not solely the personal preferences of
individual reviewers but instead rather a previously agreed upon rule by
maintainers.

Link: https://github.com/llvm/llvm-project/pull/87837
Link: https://github.com/llvm/llvm-project/pull/88157
Link:
https://discourse.llvm.org/t/hand-written-in-assembly-in-libc-setjmp-longjmp/73249/12
2024-04-22 11:57:28 -07:00
Nick Desaulniers
f626a35086
[libc] Codify header inclusion policy (#87017)
When supporting "overlay" vs "fullbuild" modes, "what ABI are you
using?" becomes a fundamental question to have concrete answers for.
Overlay mode MUST match the ABI of the system being overlayed onto;
fullbuild more flexible (the only system ABI relevant is the OS kernel).

When implementing llvm-libc we generally prefer the include-what-you use
style of avoiding transitive dependencies (since that makes refactoring
headers more painful, and slows down build times). So what header do you
include for any given type or function declaration? For any given
userspace program, the answer is straightforward. But for llvm-libc
which is trying to support multiple ABIs (at least one per
configuration), the answer is perhaps less clear.

This proposal seeks to add one layer of indirection relative to what's
being done today.

It then converts users of sigset_t and struct epoll_event and the epoll
implemenations over to this convention as an example.
2024-04-11 10:11:58 -07:00
Marc Auberer
77118536b5
[libc] Remove obsolete LIBC_HAS_BUILTIN macro (#86554)
Fixes #86546 and removes the macro `LIBC_HAS_BUILTIN`. This was
necessary to support older compilers that did not support
`__has_builtin`. All of the compilers we support already have this
builtin.
See: https://libc.llvm.org/compiler_support.html
All uses now use `__has_builtin` directly

cc @nickdesaulniers
2024-03-27 17:22:41 +01:00
Guillaume Chatelet
75fb825bcc
[libc][NFC] Rename LIBC_COMPILER_HAS_FLOAT128 to LIBC_TYPES_HAS_FLOAT128 (#83395)
Umbrella bug #83182
2024-02-29 21:59:58 +01:00
Guillaume Chatelet
53bd411e51
[libc][NFC] rename float.h macro file to types.h (#83190) 2024-02-29 10:28:53 +01:00
Nick Desaulniers
c52b467875
Reapply "[libc] build with -Werror (#73966)" (#74506)
This reverts commit 6886a52d6dbefff77f33de12ff85d654e2557f81.

Most of the errors observed in postsubmit have been addressed. We can
fix-forward the remaining ones.

Link: https://lab.llvm.org/buildbot/#/changes/117129
2024-01-08 09:07:35 -08:00
Nick Desaulniers
6886a52d6d Revert "[libc] build with -Werror (#73966)"
This reverts commit 606653091d1a66d1a83a1bfdea2883cc8d46687e.

Post submit buildbots are now red. We can use these explicit errors to better
clean up existing warnings, then reland this.

Link: #73966
2023-12-04 11:31:59 -08:00
Nick Desaulniers
606653091d
[libc] build with -Werror (#73966)
A recent commit introduced warnings observable when building unit tests.
If the
unit tests don't fail when warnings are introduced into the build, then
we
might fail to notice them in the stream of output from check-libc.

Link: https://github.com/llvm/llvm-project/pull/72763/files#r1410932348
2023-12-04 11:08:59 -08:00
Guillaume Chatelet
5e5a22caf8
[libc][NFC] Move float macro into its own header / add target os detection (#73311)
Floating point properties are a combination of target OS, target
architecture and compiler support.
 - Adding target OS detection,
 - Moving floating point type detection to its own file.

This is in preparation of adding support for `_Float16` which requires
testing compiler **version** and target architecture.
2023-11-24 16:11:05 +01:00
Guillaume Chatelet
b6bc9d72f6
[libc] Mass replace enclosing namespace (#67032)
This is step 4 of
https://discourse.llvm.org/t/rfc-customizable-namespace-to-allow-testing-the-libc-when-the-system-libc-is-also-llvms-libc/73079
2023-09-26 11:45:04 +02:00
Kazu Hirata
5dd9568717 Fix typos in documentation 2023-09-02 09:32:48 -07:00
Guillaume Chatelet
575310330b [libc][doc] Update macros documentation
Update documentaiton now that macros are laid out in a more structured way.

Reviewed By: sivachandra

Differential Revision: https://reviews.llvm.org/D143911
2023-08-08 08:02:30 +00:00
Tue Ly
d9428945df [libc][Obvious] Fix docs warning. 2023-06-26 14:32:28 +00:00
Alex Brachet
61c9052cec [libc] Add LIBC_INLINE_VAR for inline variables
These are the only variables I could find that use LIBC_INLINE. Note, these are namespace scoped constexpr so local linkage is implied. inline is useful here to silence clang's unused-const-variable variable. For Fuchsia, the distinction between LIBC_INLINE and LIBC_INLINE_VAR is helpful because we define LIBC_INLINE as `[[gnu::always_inline]] inline` when building with gcc. This isn't meaningful on variables.

Alternatively, we could make these variables simply constexpr and also add `[[maybe_unused]]`

Reviewed By: sivachandra, mcgrathr

Differential Revision: https://reviews.llvm.org/D152951
2023-06-16 15:46:32 +00:00
Kazu Hirata
e042efdab6 [libc] Fix typos in documentation 2023-04-24 23:31:48 -07:00
Siva Chandra Reddy
08b9835072 [libc][docs] Add a section about allocations and deallocations to the style doc.
Fixes #59277 - The main part of that bug has already been addressed. This commit
just adds documentation.

Reviewed By: jeffbailey

Differential Revision: https://reviews.llvm.org/D146115
2023-03-15 20:41:51 -07:00
Siva Chandra Reddy
4155503b71 [libc] Add a note about using assertions in the libc runtime code.
Reviewed By: lntue

Differential Revision: https://reviews.llvm.org/D145466
2023-03-07 10:16:50 -08:00
Siva Chandra Reddy
4052bc8674 [libc] Make errno an entrypoint.
The entrypoint has been added to the various entrypoint lists. The libc
code style doc has been updated with information on how errno should be
set from the libc runtime code.

Reviewed By: lntue

Differential Revision: https://reviews.llvm.org/D145179
2023-03-03 06:59:19 +00:00
Siva Chandra Reddy
54faf22f7b [libc][NFC] Move all developer docs into a sub-directory docs/dev. 2023-03-02 10:59:49 -08:00