12 Commits

Author SHA1 Message Date
Louis Dionne
917ada35cd
[runtimes] Always define cxx_shared, cxx_static & other targets (#80007)
This patch always defines the cxx_shared, cxx_static & other top-level
targets. However, they are marked as EXCLUDE_FROM_ALL when we don't want
to build them. Simply declaring the targets should be of no harm, and it
allows other projects to mention these targets regardless of whether
they end up being built or not.

This patch basically moves the definition of e.g. cxx_shared out of the
`if (LIBCXX_ENABLE_SHARED)` and instead marks it as EXCLUDE_FROM_ALL
conditionally on whether LIBCXX_ENABLE_SHARED is passed. It then does
the same for libunwind and libc++abi targets. I purposefully avoided to
reformat the files (which now has inconsistent indentation) because I
wanted to keep the diff minimal, and I know this is an area of the code
where folks may have downstream diffs. I will re-indent the code
separately once this patch lands.

This is a reapplication of 79ee0342dbf0, which was reverted in
a3539090884c because it broke the TSAN and the Fuchsia builds.

Resolves #77654

Differential Revision: https://reviews.llvm.org/D134221
2024-10-10 08:00:01 -04:00
Xing Xue
194f98c221
[libc++] basic_ios<wchar_t> cannot store fill character WCHAR_MAX (#89305)
`libcxx std::basic_ios` uses `WEOF` to indicate the `fill` value is
uninitialized. On some platforms (e.g AIX and zOS in 64-bit mode)
`wchar_t` is 4 bytes `unsigned` and `wint_t` is also 4 bytes which means
`WEOF` cannot be distinguished from `WCHAR_MAX` by
`std::char_traits<wchar_t>::eq_int_type()`, meaning this valid character
value cannot be stored on affected platforms (as the implementation
triggers reinitialization to `widen(’ ’)`).

This patch introduces a new helper class `_FillHelper` uses a boolean
variable to indicate whether the fill character has been initialized,
which is used by default in libcxx ABI version 2. The patch does not
affect ABI version 1 except for targets AIX in 32- and 64-bit and z/OS
in 64-bit (so that the layout of the implementation is compatible with
the current IBM system provided libc++)

This is a continuation of Phabricator patch
[D124555](https://reviews.llvm.org/D124555). This patch uses a modified
version of the [approach](https://reviews.llvm.org/D124555#3566746)
suggested by @ldionne .

---------

Co-authored-by: Louis Dionne <ldionne.2@gmail.com>
Co-authored-by: David Tenty <daltenty.dev@gmail.com>
2024-07-17 14:47:13 -04:00
Louis Dionne
8f90e6937a
[runtimes] Use LLVM libunwind from libc++abi by default (#77687)
I recently came across LIBCXXABI_USE_LLVM_UNWINDER and was surprised to
notice it was disabled by default. Since we build libunwind by default
and ship it in the LLVM toolchain, it would seem to make sense that
libc++ and libc++abi rely on libunwind for unwinding instead of using
the system-provided unwinding library (if any).

Most importantly, using the system unwinder implies that libc++abi is
ABI compatible with that system unwinder, which is not necessarily the
case. Hence, it makes a lot more sense to instead default to using the
known-to-be-compatible LLVM unwinder, and let vendors manually select a
different unwinder if desired.

As a follow-up change, we should probably apply the same default to
compiler-rt.

Differential Revision: https://reviews.llvm.org/D150897
Fixes #77662
rdar://120801778
2024-01-11 10:13:21 -05:00
varconst
f0dfe682bc [libc++][hardening] Deprecate _LIBCPP_ENABLE_ASSERTIONS.
`_LIBCPP_ENABLE_ASSERTIONS` was used to enable the "safe" mode in
libc++. Libc++ now provides the hardened mode and the debug mode that
replace the safe mode.

For backward compatibility, enabling `_LIBCPP_ENABLE_ASSERTIONS` now
enables the hardened mode. Note that the hardened mode provides
a narrower set of checks than the previous "safe" mode (only
security-critical checks that are performant enough to be used in
production).

Differential Revision: https://reviews.llvm.org/D154997
2023-07-14 16:58:47 -07:00
Haowei Wu
a353909088 Revert "[runtimes] Always define cxx_shared, cxx_static & other targets"
This reverts commit 79ee0342dbf025bc70f237bdfe9ccb4e10a592ce which
breaks the LLVM TSan bots.
2022-10-12 12:54:48 -07:00
Louis Dionne
79ee0342db [runtimes] Always define cxx_shared, cxx_static & other targets
However, mark them as EXCLUDE_FROM_ALL when we don't want to build them.
Simply declaring the targets should be of no harm, and it allows other
projects to mention these targets regardless of whether they end up
being built or not.

While the diff may not make that obvious, this patch basically
moves the definition of e.g. `cxx_shared` out of the `if (LIBCXX_ENABLE_SHARED)`
and instead marks it as `EXCLUDE_FROM_ALL` conditionally on whether
LIBCXX_ENABLE_SHARED is passed. It then does the same for libunwind
and libc++abi targets.

Differential Revision: https://reviews.llvm.org/D134221
2022-10-12 09:36:29 -04:00
Louis Dionne
7300a651f5 [libc++] Re-apply "Always build c++experimental.a""
This re-applies bb939931a1ad, which had been reverted by 09cebfb978de
because it broke Chromium. The issues seen by Chromium should be
addressed by 1d0f79558ca4.

Differential Revision: https://reviews.llvm.org/D128927
2022-07-19 10:44:19 -04:00
Hans Wennborg
09cebfb978 Revert "[libc++] Always build c++experimental.a"
This caused build failures when building Clang and libc++ together on Mac:

  fatal error: 'experimental/memory_resource' file not found

See the code review for details. Reverting until the problem and how to
solve it is better understood.

(Updates to some test files were not reverted, since they seemed
unrelated and were later updated by 340b48b267b96.)

> This is the first part of a plan to ship experimental features
> by default while guarding them behind a compiler flag to avoid
> users accidentally depending on them. Subsequent patches will
> also encompass incomplete features (such as <format> and <ranges>)
> in that categorization. Basically, the idea is that we always
> build and ship the c++experimental library, however users can't
> use what's in it unless they pass the `-funstable` flag to Clang.
>
> Note that this patch intentionally does not start guarding
> existing <experimental/FOO> content behind the flag, because
> that would merely break users that might be relying on such
> content being in the headers unconditionally. Instead, we
> should start guarding new TSes behind the flag, and get rid
> of the existing TSes we have by shipping their Standard
> counterpart.
>
> Also, this patch must jump through a few hoops like defining
> _LIBCPP_ENABLE_EXPERIMENTAL because we still support compilers
> that do not implement -funstable yet.
>
> Differential Revision: https://reviews.llvm.org/D128927

This reverts commit bb939931a1adb9a47a2de13c359d6a72aeb277c8.
2022-07-18 16:57:15 +02:00
Louis Dionne
bb939931a1 [libc++] Always build c++experimental.a
This is the first part of a plan to ship experimental features
by default while guarding them behind a compiler flag to avoid
users accidentally depending on them. Subsequent patches will
also encompass incomplete features (such as <format> and <ranges>)
in that categorization. Basically, the idea is that we always
build and ship the c++experimental library, however users can't
use what's in it unless they pass the `-funstable` flag to Clang.

Note that this patch intentionally does not start guarding
existing <experimental/FOO> content behind the flag, because
that would merely break users that might be relying on such
content being in the headers unconditionally. Instead, we
should start guarding new TSes behind the flag, and get rid
of the existing TSes we have by shipping their Standard
counterpart.

Also, this patch must jump through a few hoops like defining
_LIBCPP_ENABLE_EXPERIMENTAL because we still support compilers
that do not implement -funstable yet.

Differential Revision: https://reviews.llvm.org/D128927
2022-07-08 16:58:22 -04:00
Jake Egan
1cf4113952 [libcxx][AIX] Switch build compiler to clang
This patch switches the build compiler for AIX from ibm-clang to clang. ibm-clang++_r has `-pthread` by default, but clang for AIX doesn't, so `-pthread` had to be added to the test config. A bunch of tests now pass, so the `XFAIL` was removed. This patch also switch the build to use the visibility support available in clang-15 to control symbols exported by the shared library (AIX traditionally uses explicit export lists for this purpose).

Reviewed By: #libc, #libc_abi, daltenty, #libunwind, ldionne

Differential Revision: https://reviews.llvm.org/D127470
2022-06-13 21:45:18 -04:00
Xing Xue
dfaee3c9cf [libunwind][ci][AIX] Add libunwind to buildbot CI
Summary:
This patch changes scripts to add libunwind CI on AIX. Test config file ibm-libunwind-shared.cfg.in is introduced for testing on AIX.

Reviewed by: ldionne, MaskRay, libunwind, ibc++abi

Differential Revision: https://reviews.llvm.org/D126017
2022-06-02 09:03:10 -04:00
David Tenty
228b3b729d [libc++][AIX] Add scripts and config for building with the libcxx CI infrastructure
This initial change adds the AIX configuration to run-buildbot, an AIX
CMake cache file, and appropriate compiler and linker flags for testing
AIX to the lit "from scratch" configuration files. Either of the 32-bit or 64-bit configurations
can be built by setting `OBJECT_MODE` in the build environment (as is
typical for AIX).

Reviewed By: ldionne, #libc, #libc_abi

Differential Revision: https://reviews.llvm.org/D111244
2021-10-14 14:31:10 -04:00