5 Commits

Author SHA1 Message Date
Joseph Huber
a87105121d
[libc] Implement locale variants for 'stdlib.h' functions (#105718)
Summary:
This provides the `_l` variants for the `stdlib.h` functions. These are
just copies of the same entrypoint and don't do anything with the locale
information.
2024-08-29 14:18:37 -05:00
Nick Desaulniers
330793c91d
[libc] fix clang-tidy llvm-header-guard warnings (#82679)
Towards the goal of getting `ninja libc-lint` back to green, fix the numerous
instances of:

    warning: header guard does not follow preferred style [llvm-header-guard]

This is because many of our header guards start with `__LLVM` rather than
`LLVM`.

To filter just these warnings:

    $ ninja -k2000 libc-lint 2>&1 | grep llvm-header-guard

To automatically apply fixits:

    $ find libc/src libc/include libc/test -name \*.h | \
        xargs -n1 -I {} clang-tidy {} -p build/compile_commands.json \
        -checks='-*,llvm-header-guard' --fix --quiet

Some manual cleanup is still necessary as headers that were missing header
guards outright will have them inserted before the license block (we prefer
them after).
2024-02-28 12:53:56 -08:00
Joseph Huber
ef169f5707
[libc] Improve the implementation of the rand() function (#66131)
Summary:
This patch improves the implementation of the standard `rand()` function
by implementing it in terms of the xorshift64star pRNG as described in
https://en.wikipedia.org/wiki/Xorshift#xorshift*. This is a good,
general purpose random number generator that is sufficient for most
applications that do not require an extremely long period. This patch
also correctly initializes the seed to be `1` as described by the
standard. We also increase the `RAND_MAX` value to be `INT_MAX` as the
standard only specifies that it can be larger than 32768.
2023-09-12 16:52:20 -05:00
Siva Chandra Reddy
15ae08c1a1 [libc] Add definitions of a few missing macros and types. 2022-11-02 07:17:33 +00:00
Michael Jones
38b6f58e33 [libc] implement basic rand and srand
This provides the reference implementation of rand and srand. In future
this will likely be upgraded to something that supports full ints.

Reviewed By: sivachandra

Differential Revision: https://reviews.llvm.org/D135187
2022-10-04 13:31:26 -07:00