8 Commits

Author SHA1 Message Date
Aaron Ballman
84a3aadf0f Diagnose use of VLAs in C++ by default
Reapplication of 7339c0f782d5c70e0928f8991b0c05338a90c84c with a fix
for a crash involving arrays without a size expression.

Clang supports VLAs in C++ as an extension, but we currently only warn
on their use when you pass -Wvla, -Wvla-extension, or -pedantic.
However, VLAs as they're expressed in C have been considered by WG21
and rejected, are easy to use accidentally to the surprise of users
(e.g., https://ddanilov.me/default-non-standard-features/), and they
have potential security implications beyond constant-size arrays
(https://wiki.sei.cmu.edu/confluence/display/c/ARR32-C.+Ensure+size+arguments+for+variable+length+arrays+are+in+a+valid+range).
C++ users should strongly consider using other functionality such as
std::vector instead.

This seems like sufficiently compelling evidence to warn users about
VLA use by default in C++ modes. This patch enables the -Wvla-extension
diagnostic group in C++ language modes by default, and adds the warning
group to -Wall in GNU++ language modes. The warning is still opt-in in
C language modes, where support for VLAs is somewhat less surprising to
users.

RFC: https://discourse.llvm.org/t/rfc-diagnosing-use-of-vlas-in-c/73109
Fixes https://github.com/llvm/llvm-project/issues/62836
Differential Revision: https://reviews.llvm.org/D156565
2023-10-20 13:10:03 -04:00
Aaron Ballman
f5043f46c0 Revert "Diagnose use of VLAs in C++ by default"
This reverts commit 7339c0f782d5c70e0928f8991b0c05338a90c84c.

Breaks bots:
https://lab.llvm.org/buildbot/#/builders/139/builds/51875
https://lab.llvm.org/buildbot/#/builders/164/builds/45262
2023-10-20 10:00:18 -04:00
Aaron Ballman
7339c0f782 Diagnose use of VLAs in C++ by default
Clang supports VLAs in C++ as an extension, but we currently only warn
on their use when you pass -Wvla, -Wvla-extension, or -pedantic.
However, VLAs as they're expressed in C have been considered by WG21
and rejected, are easy to use accidentally to the surprise of users
(e.g., https://ddanilov.me/default-non-standard-features/), and they
have potential security implications beyond constant-size arrays
(https://wiki.sei.cmu.edu/confluence/display/c/ARR32-C.+Ensure+size+arguments+for+variable+length+arrays+are+in+a+valid+range).
C++ users should strongly consider using other functionality such as
std::vector instead.

This seems like sufficiently compelling evidence to warn users about
VLA use by default in C++ modes. This patch enables the -Wvla-extension
diagnostic group in C++ language modes by default, and adds the warning
group to -Wall in GNU++ language modes. The warning is still opt-in in
C language modes, where support for VLAs is somewhat less surprising to
users.

RFC: https://discourse.llvm.org/t/rfc-diagnosing-use-of-vlas-in-c/73109
Fixes https://github.com/llvm/llvm-project/issues/62836
Differential Revision: https://reviews.llvm.org/D156565
2023-10-20 09:50:21 -04:00
Saiyedul Islam
ff260ad0e0 [OpenMP] Ensure testing for versions 4.5 and default - Part 3
This third patch in the series removes version 5.0 string from
test cases making them check for default version. It also add test
cases for version 4.5.

Reviewed By: ABataev

Differential Revision: https://reviews.llvm.org/D85214
2020-08-27 19:37:04 +00:00
Alexey Bataev
1c1d9d9d7f [OPENMP50]Support 'task' modifier in reduction clauses.
Summary:
Added basic support for 'task' modifier in the reduction clauses in
non-simd parallel and worksharing constructs.

Reviewers: jdoerfert

Subscribers: yaxunl, guansong, cfe-commits, caomhin

Tags: #clang

Differential Revision: https://reviews.llvm.org/D78738
2020-04-30 14:43:01 -04:00
cchen
47d6094d7f [OpenMP50] Add parallel master construct
Reviewers: ABataev, jdoerfert

Reviewed By: ABataev

Subscribers: rnk, jholewinski, guansong, arphaman, jfb, cfe-commits, sandoval, dreachem

Tags: #clang

Differential Revision: https://reviews.llvm.org/D70726
2019-12-05 14:35:27 -05:00
Reid Kleckner
33f6d465d7 Revert "[OpenMP50] Add parallel master construct, by Chi Chun Chen."
This reverts commit 713dab21e27c987b9114547ce7136bac2e775de9.

Tests do not pass on Windows.
2019-12-04 14:50:06 -08:00
cchen
713dab21e2 [OpenMP50] Add parallel master construct, by Chi Chun Chen.
Reviewers: ABataev, jdoerfert

Reviewed By: ABataev

Subscribers: jholewinski, guansong, arphaman, jfb, cfe-commits, sandoval, dreachem

Tags: #clang

Differential Revision: https://reviews.llvm.org/D70726
2019-12-04 14:53:17 -05:00