This patch removes the ability to build the runtimes in the 32 bit
multilib configuration, i.e. using -m32. Instead of doing this, one
should cross-compile the runtimes for the appropriate target triple,
like we do for all other triples.
As it stands, -m32 has several issues, which all seem to be related to
the fact that it's not well supported by the operating systems that
libc++ support. The simplest path towards fixing this is to remove
support for the configuration, which is also the best course of action
if there is little interest for keeping that configuration. If there
is a desire to keep this configuration around, we'll need to do some
work to figure out the underlying issues and fix them.
Differential Revision: https://reviews.llvm.org/D114473
This does mostly the same as D112126, but for the runtimes cmake files.
Most of that is straightforward, but the interdependency between
libcxx and libunwind is tricky:
Libunwind is built at the same time as libcxx, but libunwind is not
installed yet. LIBCXXABI_USE_LLVM_UNWINDER makes libcxx link directly
against the just-built libunwind, but the compiler implicit -lunwind
isn't found. This patch avoids that by adding --unwindlib=none if
supported, if we are going to link explicitly against a newly built
unwinder anyway.
Differential Revision: https://reviews.llvm.org/D113253
We don't use Python 2 anymore, so let us do the recommended fix instead
of using the workaround made for Python 2.
Differential Revision: https://reviews.llvm.org/D107715
Using user-provided data as a format string is a well known source of
security vulnerabilities. For this reason, it is a good idea to compile
our code with -Wformat-nonliteral, which basically warns if a non-constant
string is used as a format specifier. This is the compiler’s best signal
that a format string call may be insecure.
I audited the code after adding the warning and made sure that the few
places where we used a non-literal string as a format string were not
potential security issues. I either disabled the warning locally for
those instances or fixed the warning by using a literal. The idea is
that after we add the warning to the build, any new use of a non-literal
string in a format string will trigger a diagnostic, and we can either
get rid of it or disable the warning locally, which is a way of
acknowledging that it has been audited.
I also looked into enabling it in the test suite, which would perhaps
allow finding additional instances of it in our headers, however that
is not possible at the moment because Clang doesn't support putting
__attribute__((__format__(...))) on variadic templates, which would
be needed.
rdar://84571685
Differential Revision: https://reviews.llvm.org/D112927
There's a lot of duplicated calls to find various compiler-rt libraries
from build of runtime libraries like libunwind, libc++, libc++abi and
compiler-rt. The compiler-rt helper module already implemented caching
for results avoid repeated Clang invocations.
This change moves the compiler-rt implementation into a shared location
and reuses it from other runtimes to reduce duplication and speed up
the build.
Differential Revision: https://reviews.llvm.org/D88458
In 395271a, I simplified how we handled the target triple for the
runtimes. However, in doing so, we stopped considering the default
in CMAKE_CXX_COMPILER_TARGET, so we'd use the LLVM_DEFAULT_TARGET_TRIPLE
(which is the host triple) even if CMAKE_CXX_COMPILER_TARGET was specified.
This commit fixes that problem and also refactors the code so that it's
easy to see what the default value is.
The fact that nobody seems to have been broken by this makes me think
that perhaps nobody is using CMAKE_CXX_COMPILER_TARGET to specify the
triple -- but it should still work.
Differential Revision: https://reviews.llvm.org/D111672
There's a lot of duplicated calls to find various compiler-rt libraries
from build of runtime libraries like libunwind, libc++, libc++abi and
compiler-rt. The compiler-rt helper module already implemented caching
for results avoid repeated Clang invocations.
This change moves the compiler-rt implementation into a shared location
and reuses it from other runtimes to reduce duplication and speed up
the build.
Differential Revision: https://reviews.llvm.org/D88458
Some embedded platforms do not wish to support the C library functionality
for handling wchar_t because they have no use for it. It makes sense for
libc++ to work properly on those platforms, so this commit adds a carve-out
of functionality for wchar_t.
Unfortunately, unlike some other carve-outs (e.g. random device), this
patch touches several parts of the library. However, despite the wide
impact of this patch, I still think it is important to support this
configuration since it makes it much simpler to port libc++ to some
embedded platforms.
Differential Revision: https://reviews.llvm.org/D111265
This enforces libcxx and its benchmarks are compiled by a C++20 capable
compiler. Based on review comments in D103413.
Differential Revision: https://reviews.llvm.org/D110338
This option is used to select between the format headers output column
width option. This option should be independent of the locale setting.
It's encouraged to default to Unicode unless the platform doesn't offer
that option.
[format.string.std]/10
```
For the purposes of width computation, a string is assumed to be in a
locale-independent, implementation-defined encoding. Implementations
should use a Unicode encoding on platforms capable of displaying Unicode
```
Reviewed By: #libc, ldionne, vitaut
Differential Revision: https://reviews.llvm.org/D103379
Clang used to support [[nodebug]] everywhere except on typedefs. Since
we don't support such old Clangs anymore, we can get rid of _LIBCPP_NODEBUG_TYPE
in favour of always using _LIBCPP_NODEBUG.
Differential Revision: https://reviews.llvm.org/D108996
Based on https://github.com/NuxiNL/cloudlibc, it appears that the CloudABI
project has been abandoned. This patch removes a bunch of CloudABI specific
logic that had been added to support that platform.
Note that some knobs like LIBCXX_ENABLE_STDIN and LIBCXX_ENABLE_STDOUT
coud be useful in their own right, however those are currently broken.
If we want to re-add such knobs in the future, we can do it like we've
done it for localization & friends so that we can officially support
that configuration.
Differential Revision: https://reviews.llvm.org/D108637
Adds a new CMake option to disable the usage of incomplete headers.
These incomplete headers are not guaranteed to be ABI stable. This
option is intended to be used by vendors so they can avoid their users
from code that's not ready for production usage.
The option is enabled by default.
Differential Revision: https://reviews.llvm.org/D106763
Instead of using TARGET_TRIPLE, which is always set to LLVM_DEFAULT_TARGET_TRIPLE,
use that variable directly to populate the various XXXX_TARGET_TRIPLE
variables in the runtimes.
This re-applies 77396bbc98 and 5099e01568, which were reverted in
850b57c5fb because they broke the build.
Differential Revision: https://reviews.llvm.org/D106009
When a target triple is specified in CMake via XXX_TARGET_TRIPLE, we tried
passing the --target=<...> flag to the compiler. However, not all compilers
support that flag (e.g. GCC, which is not a cross-compiler). As a result,
setting e.g. LIBCXX_TARGET_TRIPLE=<host-triple> would end up trying to
pass --target=<host-triple> to GCC, which breaks everything because the
flag isn't even supported.
This commit only adds `--target=<...>` & friends to the flags if it is
supported by the compiler.
One could argue that it's confusing to pass LIBCXX_TARGET_TRIPLE=<...>
and have it be ignored. That's correct, and one possibility would be
to assert that the requested triple is the same as the host triple when
we know the compiler is unable to cross-compile. However, note that this
is a pre-existing issue (setting the TARGET_TRIPLE variable never had an
influence on the flags passed to the compiler), and also fixing that is
starting to look like reimplementing a lot of CMake logic that is already
handled with CMAKE_CXX_COMPILER_TARGET.
Differential Revision: https://reviews.llvm.org/D106082
As we automate more and more things in the library, it becomes useful for
contributors to have a single target for running all the automation as
part of their workflow. This commit adds a new `libcxx-generate-files`
target that should re-generate all the auto-generated files in the library.
As a fly-by, I also revamped the documentation on Contributing to account
for this new target and present it as a bullet list of things to check
before committing. I also added a few things that are often overlooked
to that list, such as updating the synopsis and the status files.
Differential Revision: https://reviews.llvm.org/D106067
This commit reverts 5099e01568 and 77396bbc98, which broke the build
in various ways. I'm reverting until I can investigate, since that
change appears to be way more subtle than it seemed.
This is a second attempt at D101497, which landed as
9a9bc76c0e but had to be reverted in
8cf7ddbdd4.
This issue was that in the case that `COMPILER_RT_INSTALL_PATH` is
empty, expressions like "${COMPILER_RT_INSTALL_PATH}/bin" evaluated to
"/bin" not "bin" as intended and as was originally.
One solution is to make `COMPILER_RT_INSTALL_PATH` always non-empty,
defaulting it to `CMAKE_INSTALL_PREFIX`. D99636 adopted that approach.
But, I think it is more ergonomic to allow those project-specific paths
to be relative the global ones. Also, making install paths absolute by
default inhibits the proper behavior of functions like
`GNUInstallDirs_get_absolute_install_dir` which make relative install
paths absolute in a more complicated way.
Given all this, I will define a function like the one asked for in
https://gitlab.kitware.com/cmake/cmake/-/issues/19568 (and needed for a
similar use-case).
---
Original message:
Instead of using `COMPILER_RT_INSTALL_PATH` through the CMake for
complier-rt, just use it to define variables for the subdirs which
themselves are used.
This preserves compatibility, but later on we might consider getting rid
of `COMPILER_RT_INSTALL_PATH` and just changing the defaults for the
subdir variables directly.
---
There was a seaming bug where the (non-Apple) per-target libdir was
`${target}` not `lib/${target}`. I suspect that has to do with the docs
on `COMPILER_RT_INSTALL_PATH` saying was the library dir when that's no
longer true, so I just went ahead and fixed it, allowing me to define
fewer and more sensible variables.
That last part should be the only behavior changes; everything else
should be a pure refactoring.
---
I added some documentation of these variables too. In particular, I
wanted to highlight the gotcha where `-DSomeCachePath=...` without the
`:PATH` will lead CMake to make the path absolute. See [1] for
discussion of the problem, and [2] for the brief official documentation
they added as a result.
[1]: https://cmake.org/pipermail/cmake/2015-March/060204.html
[2]: https://cmake.org/cmake/help/latest/manual/cmake.1.html#options
In 38b2dec37e the problem was somewhat
misidentified and so `:STRING` was used, but `:PATH` is better as it
sets the correct type from the get-go.
---
D99484 is the main thrust of the `GnuInstallDirs` work. Once this lands,
it should be feasible to follow both of these up with a simple patch for
compiler-rt analogous to the one for libcxx.
Reviewed By: phosek, #libc_abi, #libunwind
Differential Revision: https://reviews.llvm.org/D105765
I'm not sure what that gains us, and it creates a problem when
trying to run the tests against libc++ with a custom install name
dir (e.g. /usr/lib), since the library that we link against (in
the build tree) will advertise itself as /usr/lib/libc++.dylib,
so we end up linking against the system dylib at runtime.
Differential Revision: https://reviews.llvm.org/D105499
When using the per-target runtime build, it may be desirable to have
different __config_site headers for each target where all targets cannot
share a single configuration.
The layout used for libc++ headers after this change is:
```
include/
c++/
v1/
<libc++ headers except for __config_site>
<target1>/
c++/
v1/
__config_site
<target2>/
c++/
v1/
__config_site
<other targets>
```
This is the most optimal layout since it avoids duplication, the only
headers that's per-target is __config_site, all other headers are
shared across targets. This also means that we no need two
-isystem flags: one for the target-agnostic headers and one for
the target specific headers.
Differential Revision: https://reviews.llvm.org/D89013
The new layout more closely matches the layout used by other compilers.
This is only used when LLVM_ENABLE_PER_TARGET_RUNTIME_DIR is enabled.
Differential Revision: https://reviews.llvm.org/D100869
These variables were introduced during early work on the runtimes build
but were obsoleted by {LIBCXX,LIBCXXABI,LIBUNWIND}_INSTALL_LIBRARY_DIR.
Differential Revision: https://reviews.llvm.org/D99697
This will avoid typos like `_LIBCPP_STD_VERS` (<future>) or using `#if TEST_STD_VER > 17` without including "test_macros.h".
Reviewed By: ldionne, #libc
Differential Revision: https://reviews.llvm.org/D99515
Prior to this patch, we would generate a fancy <__config> header by
concatenating <__config_site> and <__config>. This complexifies the
build system and also increases the difference between what's tested
and what's actually installed.
This patch removes that complexity and instead simply installs <__config_site>
alongside the libc++ headers. <__config_site> is then included by <__config>,
which is much simpler. Doing this also opens the door to having different
<__config_site> headers depending on the target, which was impossible before.
It does change the workflow for testing header-only changes to libc++.
Previously, we would run `lit` against the headers in libcxx/include.
After this patch, we run it against a fake installation root of the
headers (containing a proper <__config_site> header). This makes use
closer to testing what we actually install, which is good, however it
does mean that we have to update that root before testing header changes.
Thus, we now need to run `ninja check-cxx-deps` before running `lit` by
hand.
Differential Revision: https://reviews.llvm.org/D97572
The MSVC -Wall (or /Wall) option maps (in clang-cl) to the GCC style
option -Weverything, which we don't really want. Instead use -W4 which
is the corresponding MSVC option.
This silences the build with clang-cl, which previously used to
output 100 warnings per translation unit.
Differential Revision: https://reviews.llvm.org/D98035
This feature can be built successfully for windows now. However,
the helper functions for __int128_t aren't available in MSVC
configurations, so don't enable it by default there yet. (See
https://reviews.llvm.org/D91139 for discussion on how to proceed
with things in MSVC environments.)
Differential Revision: https://reviews.llvm.org/D97075
Let's use -nostdlib++ rather than -nodefaultlibs when building libc++/libc++abi/libunwind libraries. The default is -nostdlib++ if supported by a build compiler like it is the case with clang, otherwise -nodefaultlibs is used as before.
This change is needed to avoid additional changes at the link step and not to increase the maintenance costs. If clang with -nodefaultlibs is used all the libraries which are removed but required would have to be manually added in. This set of libraries are unique and will send out.
The propose change will allow to make the link step simple for other platforms as well.
Reviewed By: #libc, #libc_abi, ldionne
Differential Revision: https://reviews.llvm.org/D95875
Previously, LIBCXX_ENABLE_FILESYSTEM controlled only whether the filesystem
support was compiled into libc++'s library. This commit promotes the
setting to a first-class option like LIBCXX_ENABLE_LOCALIZATION, where
the whole library is aware of the setting and features that depend on
<filesystem> won't be provided at all. The test suite is also properly
annotated such that tests that depend on <filesystem> are disabled when
the library doesn't support it.
This is an alternative to https://llvm.org/D94824, but also an improvement
along the lines of LIBCXX_ENABLE_LOCALIZATION that I had been wanting to
make for a while.
Differential Revision: https://reviews.llvm.org/D94921
cmake_minimum_required(VERSION) calls cmake_policy(VERSION),
which sets all policies up to VERSION to NEW.
LLVM started requiring CMake 3.13 last year, so we can remove
a bunch of code setting policies prior to 3.13 to NEW as it
no longer has any effect.
Reviewed By: phosek, #libunwind, #libc, #libc_abi, ldionne
Differential Revision: https://reviews.llvm.org/D94374
This commit makes it clear that the typeinfo comparison implementation
is automatically selected by default, and that the CMake option only
overrides the value. This has been a source of confusion and bugs ever
since we've introduced complexity in that area, so I'm trying to simplify
it while still allowing for some control on the implementation.
Differential Revision: https://reviews.llvm.org/D91574
Also, enable them whenever we detect that gdb is available. Previously,
these tests would basically never run because they relied on a CMake
configuration option that defaulted to OFF.
Differential Revision: https://reviews.llvm.org/D91434
The unavailability of posix_memalign on z/OS forces us to define _LIBCPP_HAS_NO_LIBRARY_ALIGNED_ALLOCATION'. The use of posix_memalign is being used in libcxx/src/new.cpp.
Reviewed By: #libc, ldionne
Differential Revision: https://reviews.llvm.org/D90178
Currently, vendor-specific availability markup is enabled by default.
This means that even when building against trunk libc++, the headers
will by default prevent you from using some features that were not
released in the dylib on your target platform. This is a source of
frustration since people building libc++ from sources are usually not
trying to use some vendor's released dylib.
For that reason, I've been thinking for a long time that availability
annotations should be off by default, which is the primary change that
this commit enables.
In addition, it reworks the implementation to make it easier for new
vendors to add availability annotations for their platform, and it
refreshes the documentation to reflect the current state of the codebase.
Finally, a CMake configuration option is added to control whether
availability annotations should be turned on for the flavor of libc++
being created. The intent is for vendors like Apple to turn it on, and
for the upstream libc++ to leave it off (the default).
Differential Revision: https://reviews.llvm.org/D90843
Those are part of the library, and shipping them just adds a tiny bit of
size to the distribution. This was originally added in b422ecc7de to
make it possible to match the Makefile build, which doesn't exist anymore.
The upside is build system simplification.
Previously, these had to be set manually when building each of the
projects standalone, in order to get proper symbol visibility when
combining the two libraries.
Differential Revision: https://reviews.llvm.org/D90021
When porting libc++ to embedded systems, it can be useful to drop support
for localization, which these systems don't implement or care about.
Differential Revision: https://reviews.llvm.org/D90072
This is a massive revert of the following commits (from most revent to oldest):
2b9b7b5775.
529ac3319728270234f169c2087283b5aa67446e5d796645d6
After checking-in the __config_site change, a lot of things started breaking
due to widespread reliance on various aspects of libc++'s build, notably the
fact that we can include the headers from the source tree, but also reliance
on various "internal" CMake variables used by the runtimes build and compiler-rt.
These were unintended consequences of the change, and after two days, we
still haven't restored all the bots to being green. Instead, now that I
understand what specific areas this will blow up in, I should be able to
chop up the patch into smaller ones that are easier to digest.
See https://reviews.llvm.org/D89041 for more details on this adventure.
This commit should really be named "Workaround external projects depending
on libc++ build system implementation details". It seems that the compiler-rt
build (and perhaps other projects) is relying on the fact that we copy libc++
and libc++abi headers to `<build-root>/include/c++/v1`. This was changed
by 5d796645, which moved the headers to `<build-root>/projects/libcxx/include/c++/v1`
and broke the compiler-rt build.
I'm committing this workaround to fix the compiler-rt build, but we should
remove reliance on implementation details like that. The correct way to
setup the compiler-rt build would be to "link" against the `cxx-headers`
target in CMake, or to run `install-cxx-headers` using an appropriate
installation prefix, and then manually add a `-I` path to that location.
Prior to this patch, we would generate a fancy <__config> header by
concatenating <__config_site> and <__config>. This complexifies the
build system and also increases the difference between what's tested
and what's actually installed.
This patch removes that complexity and instead simply installs <__config_site>
alongside the libc++ headers. <__config_site> is then included by <__config>,
which is much simpler. Doing this also opens the door to having different
<__config_site> headers depending on the target, which was impossible before.
It does change the workflow for testing header-only changes to libc++.
Previously, we would run `lit` against the headers in libcxx/include.
After this patch, we run it against a fake installation root of the
headers (containing a proper <__config_site> header). This makes use
closer to testing what we actually install, which is good, however it
does mean that we have to update that root before testing header changes.
Thus, we now need to run `ninja check-cxx-deps` before running `lit` by
hand.
This commit was originally applied in 1e46d1aa3 and reverted in eb60c487
because it broke the libc++abi and libunwind test suites. This has now
been fixed.
Differential Revision: https://reviews.llvm.org/D89041
Prior to this patch, we would generate a fancy <__config> header by
concatenating <__config_site> and <__config>. This complexifies the
build system and also increases the difference between what's tested
and what's actually installed.
This patch removes that complexity and instead simply installs <__config_site>
alongside the libc++ headers. <__config_site> is then included by <__config>,
which is much simpler. Doing this also opens the door to having different
<__config_site> headers depending on the target, which was impossible before.
It does change the workflow for testing header-only changes to libc++.
Previously, we would run `lit` against the headers in libcxx/include.
After this patch, we run it against a fake installation root of the
headers (containing a proper <__config_site> header). This makes use
closer to testing what we actually install, which is good, however it
does mean that we have to update that root before testing header changes.
Thus, we now need to run `ninja check-cxx-deps` before running `lit` by
hand.
Differential Revision: https://reviews.llvm.org/D89041
Previously, we would define new/delete in both libc++ and libc++abi.
Not only does this cause code bloat, but also it's technically an ODR
violation since we don't know which operator will be selected. Furthermore,
since those are weak definitions, we should strive to have as few of them
as possible (to improve load times).
My preferred choice would have been to put the operators in libc++ only
by default, however that would create a circular dependency between
libc++ and libc++abi, which GNU linkers don't handle.
Folks who want to ship new/delete in libc++ instead of libc++abi are
free to do so by turning on LIBCXX_ENABLE_NEW_DELETE_DEFINITIONS at
CMake configure time.
On Apple platforms, this shouldn't be an ABI break because we re-export
the new/delete symbols from libc++abi. This change actually makes libc++
behave closer to the system libc++ shipped on Apple platforms.
On other platforms, this is an ABI break for people linking against libc++
but not libc++abi. However, vendors have been consulted in D68269 and no
objection was raised. Furthermore, the definitions can be controlled to
appear in libc++ instead with the CMake option.
Differential Revision: https://reviews.llvm.org/D68269
Some platforms, like several embedded platforms, do not provide a source
of randomness through a random device. This commit makes it possible to
build and test libc++ for such platforms, i.e. without std::random_device.
Surprisingly, the only functionality that doesn't work on such platforms
is std::random_device itself -- everything else in <random> still works,
one just has to find alternative ways to seed the PRNGs.
Remove check for standalone and shared library mode in libcxxabi to
allow including tests in said mode. This check prevented running the
tests in standalone mode with static libraries, which is the case for
baremetal targets.
Fix check-unwind target trying to use a non-existent llvm-lit executable
in standalone mode. Copy the HandleOutOfTreeLLVM logic from libcxxabi to
libunwind in order to make the tests work in standalone mode.
Reviewed By: ldionne, #libc_abi, #libc
Differential Revision: https://reviews.llvm.org/D86540
There are several places in LLVM's CMake setup that try to remove the
`stdlib=...` flag from the CMake flags. All this code however only considered
the `-stdlib=` variant of the flag but not the alternative spelling with a
double dash. This causes that when one adds `--stdlib=...` to the user-provided
CMake flags that this gets transformed into just `-` which ends up causing the
build system to think it should read the source from stdin (which then lead to
very confusing build errors).
This just adds the alternative spelling before the`-stdlib=` variant in all
these places
Reviewed By: ldionne
Differential Revision: https://reviews.llvm.org/D87133
Some libc++ builds may want to disable support for the debug mode,
for example to reduce code size or because the current implementation
of the debug mode requires a global map. This commit adds the
LIBCXX_ENABLE_DEBUG_MODE CMake option and ties it into the test
suite.
It also adds a CI job to test this configuration going forward.
Differential Revision: https://reviews.llvm.org/D88923
LLVM has bumped the minimum required CMake version to 3.13.4, so this has become dead code.
Reviewed By: #libc, ldionne
Differential Revision: https://reviews.llvm.org/D87189
This avoids issues when building the dylib for deployment targets that
don't support aligned allocation, where Clang normally triggers an
error to warn users their code would break at runtime when back-deployed.
Since we're building the dylib itself, which contains the aligned
allocation functions, we don't want to trigger that error.
Differential Revision: https://reviews.llvm.org/D84418
add_compile_options is more sensitive to its location in the file than add_definitions--it only takes effect for sources that are added after it. This updated patch ensures that the add_compile_options is done before adding any source files that depend on it.
Using add_definitions caused the flag to be passed to rc.exe on Windows and thus broke Windows builds.
This allows simplifying the implementation of barriers.
This is a re-commit of 1ac403bd14, which had to be reverted in
64a9c944fc because the minimum CMake version wasn't high enough.
Now that we've upgraded, we can do this.
Differential Revision: https://reviews.llvm.org/D75243
After lots of follow-up fixes, there are still problems, such as
-Wno-suggest-override getting passed to the Windows Resource Compiler
because it was added with add_definitions in the CMake file.
Rather than piling on another fix, let's revert so this can be re-landed
when there's a proper fix.
This reverts commit 21c0b4c1e8.
This reverts commit 81d68ad27b.
This reverts commit a361aa5249.
This reverts commit fa42b7cf29.
This reverts commit 955f87f947.
This reverts commit 8b16e45f66.
This reverts commit 308a127a38.
This reverts commit 274b6b0c7a.
This reverts commit 1c7037a2a5.
This patch adds Clang's new (and GCC's old) -Wsuggest-override to the warning flags for the LLVM build. The warning is a stronger form of -Winconsistent-missing-override which warns _everywhere_ that override is missing, not just in places where it's inconsistent within a class.
Some directories in the monorepo need the warning disabled for compatibility's, or sanity's, sake; in particular, libcxx/libcxxabi, and any code implementing or interoperating with googletest, googlemock, or google benchmark (which do not themselves use override). This patch adds -Wno-suggest-override to the relevant CMakeLists.txt's to accomplish this.
Differential Revision: https://reviews.llvm.org/D84126
Instead of detecting it automatically but also allowing for the setting
to be specified explicitly, always detect whether exceptions are enabled
based on whether -fno-rtti (or equivalent) is used. It's less confusing
to have a single way of tweaking that knob.
This change follows the lead of 71d88cebfb.
Instead of having complex logic around how to include the libc++ headers
and __config_site, handle that by defining cxx-headers as an INTERFACE
library and linking against it. After this patch, linking against cxx-headers
is sufficient to get the right __config_site include and include paths
for libc++.
Differential Revision: https://reviews.llvm.org/D82702
This allows passing parameters to the test suites without using
LLVM_LIT_ARGS. The problem is that we sometimes want to set some
Lit arguments on the CMake command line, but the Lit parameters in
a CMake cache file. If the only knob to do that is LLVM_LIT_ARGS,
the command-line entry overrides the cache one, and the parameters
set by the cache are ignored.
This fixes a current issue with the build bots that they completely
ignore the 'std' param set by Lit, because other Lit arguments are
provided via LLVM_LIT_ARGS on the CMake command-line.
Instead of detecting it automatically (in libc++) and relying on
_LIBCXXABI_NO_EXCEPTIONS being set explicitly (in libc++abi), always
detect whether exceptions are enabled automatically.
This commit also removes support for specifying -D_LIBCPP_NO_EXCEPTIONS
and -D_LIBCXXABI_NO_EXCEPTIONS explicitly -- those should just be inferred
from using -fno-exceptions (or an equivalent flag).
Allowing both -D_FOO_NO_EXCEPTIONS to be provided explicitly and trying
to detect it automatically is just confusing, especially since we did
specify it explicitly when building libc++abi. We should have only one
way to detect whether exceptions are enabled, but it should be robust.
Doing so doesn't work reliably, since it relies on LLVM_* implementation
detail variables being set. Furthermore, since we rely on the lit.site.cfg
being generated, running the tests requires LIBCXX_INCLUDE_TESTS=ON anyway.
The runtimes build includes libcxx/include/CMakeLists.txt directly instead
of going through the top-level CMake file. This not-very-hygienic inclusion
caused some variables like LIBCXX_BINARY_DIR not to be defined properly,
and the config_site generation logic to fail after landing 53623d4aa7.
This patch works around this issue by defining the missing variables.
However, the proper fix for this would be for the runtimes build to
always go through libc++'s top-level CMakeLists.txt. Doing otherwise
is unsupported.
Before this patch, the __config_site header was only generated when at
least one __config_site macro needed to be defined. This lead to two
different code paths in how libc++ is configured, depending on whether
a __config_site header was generated or not. After this patch, the
__config_site is always generated, but it can be empty in case there
are no macros to define in it.
More context on why this change is important
--------------------------------------------
In addition to being confusing, this double-code-path situation lead to
broken code being checked in undetected in 2405bd6898, which introduced
the LIBCXX_HAS_MERGED_TYPEINFO_NAMES_DEFAULT CMake setting. Specifically,
the _LIBCPP_HAS_MERGED_TYPEINFO_NAMES_DEFAULT <__config_site> macro was
supposed NOT to be defined unless LIBCXX_HAS_MERGED_TYPEINFO_NAMES_DEFAULT
was specified explicitly on the CMake command line. Instead, what happened
is that it was defined to 0 if it wasn't specified explicitly and a
<__config_site> header was generated. And defining that macro to 0 had
the important effect of using the non-unique RTTI comparison implementation,
which changes the ABI.
This change in behavior wasn't noticed because the <__config_site> header
is not generated by default. However, the Apple configuration does cause
a <__config_site> header to be generated, which lead to the wrong RTTI
implementation being used, and to https://llvm.org/PR45549. We came close
to an ABI break in the dylib, but were saved due to a downstream-only
change that overrode the decision of the <__config_site> for the purpose
of RTTI comparisons in libc++abi. This is an incredible luck that we should
not rely on ever again.
While the problem itself was fixed with 2464d8135e by setting
LIBCXX_HAS_MERGED_TYPEINFO_NAMES_DEFAULT explicitly in the Apple
CMake cache and then in d0fcdcd28f by making the setting less
brittle, the point still is that we should have had a single code
path from the beginning. Unlike most normal libraries, the macros
that configure libc++ are really complex, there's a lot of them and
they control important properties of the C++ runtime. There must be
a single code path for that, and it must be simple and robust.
Differential Revision: https://reviews.llvm.org/D80927
Before this patch, the libc++ test suite first loads lit.site.cfg
(generated by CMake), and then lit.cfg. It's also possible to load
lit.cfg before lit.site.cfg and to point to a custom lit.site.cfg
file using '--param=libcxx_site_config'. However, in that case, lit.cfg
still relies on the site configuration filling up the 'config' object
like the default lit.site.cfg file does, which isn't flexible enough.
This commit simplifies the setup by having just a single Lit site config
file per CMake configuration, and always loading exactly that config file.
However, the config file to use can be selected when setting up CMake via
the LIBCXX_TEST_CONFIG setting. Furthermore, the site configs are entirely
standalone, which means that a new site config can be added that doesn't
need to conform what's expected by config.py.
Differential Revision: https://reviews.llvm.org/D81846
Before this patch, we tried detecting whether small atomics were available
without linking against libatomic. However, that's not really what we want
to know -- instead, we want to know what's required in order to support
atomics fully, which is to link against libatomic when it's provided.
That is both much simpler, and it doesn't suffer the problem that we would
not link against libatomic when small atomics didn't require it, which
lead to non-lockfree atomics never working.
Furthermore, because we understand that some platforms might not want to
(or be able to) ship non-lockfree atomics, we add that notion to the test
suite, independently of a potential extern library.
After this patch, we therefore:
(1) Link against libatomic when it is provided
(2) Independently detect whether non-lockfree atomics are supported in
the test suite, regardless of whether that means we're linking against
an external library or not (which is an implementation detail).
Differential Revision: https://reviews.llvm.org/D81190
When the __config_site header is generated, but LIBCXX_HAS_MERGED_TYPEINFO_NAMES_DEFAULT
wasn't specified, _LIBCPP_HAS_MERGED_TYPEINFO_NAMES_DEFAULT would be defined
to 0, which was the NonUnique RTTI comparison implementation. The intent
was to use the Unique RTTI comparison implementation in that case, which
caused https://llvm.org/PR45549.
Instead, use a proper "switch" to select the RTTI comparison implementation.
Note that 0 can't be used as a value, because that is treated the same
by CMake as a variable that is just not defined.
Differential Revision: https://reviews.llvm.org/D80037
Android doesn't have a libgcc_s and uses libgcc instead, so adjust the
build accordingly. This matches compiler-rt's build setup. libc++abi and
libunwind were already checking for libgcc but in a different context.
This change makes them search only for libgcc on Android now, but the
code to link against libgcc if it were present was already there.
Reviewed By: #libc, #libc_abi, #libunwind, rprichard, srhines
Differential Revision: https://reviews.llvm.org/D78787
Summary:
This patch add the dataflow option to LLVM_USE_SANITIZER and documents
it.
Tested via check-cxx (wip to fix the errors).
Reviewers: morehouse, #libc!
Subscribers: mgorny, cfe-commits, libcxx-commits
Tags: #clang, #libc
Differential Revision: https://reviews.llvm.org/D78390
Summary:
Allow users to simultaneously enable address and undefined behavior
sanitizers, in the same manner that LLVM's 'HandleLLVMOptions.cmake'
allows.
Prior to this patch, `cmake -DLLVM_USE_SANITIZER="Address;Undefined"`
would succeed and the build would build most of the LLVM project with
`-fsanitize=address,undefined`, but a warning would be printed by
libcxx's CMake, and the build would use neither sanitizer. This
patch results in no warning being printed, and both sanitizers are used
in building libcxx.
Reviewers: jroelofs, EricWF, ldionne, #libc!
Subscribers: mgorny, dexonsmith, llvm-commits, libcxx-commits
Tags: #libc
Differential Revision: https://reviews.llvm.org/D77466
This commit removes support for building against the system libc++abi,
which was supported on Apple platforms. This is basically never what we
want to do, since libc++ and libc++abi are coupled and building a trunk
libc++ against an older libc++abi can lead to incompatibilities (and
good luck debugging them!). It might have made some sense to support
that when the monorepo did not exist, however I don't think this is
anything but a footgun nowadays.
Furthermore, based on the newly-made assumption that we're building
against the monorepo libc++abi, we can simplify the search path logic
for finding libc++abi.
This area of our build system has a lot of technical debt accumulated,
and it's surprisingly difficult to change. We've tried different things
and failed several times in the past. I did test this change on our
Docker image for the build bots and on Apple platforms, however it is
possible that this breaks some unknown configuration, in which case it
should be fine to revert this (so we can try again!).
We will soon start removing technical debt and sharing code between the
two directories, so this first step is meant to discover potential places
where the libraries are built outside of a monorepo layout. I imagine
this could happen as a remnant of the pre-monorepo setup.
This was discussed on the libcxx-dev mailing list and we got overall
consensus on the direction. All consumers of libc++ and libc++abi
should already be doing so through the monorepo, however it is
possible that we catch some stragglers with this patch, in which
case it may need to be reverted temporarily.
Differential Revision: https://reviews.llvm.org/D76102
This is failing to compile on Windows because clang-cl is trying to
use the path with quotes, dropping them resolves the issue.
Differential Revision: https://reviews.llvm.org/D73525
libc++ on Android needs to be linked against libandroid_support on API
levels less than 21 to provide needed functions that aren't in the libc
on those platforms (e.g. posix_memalign for libcxxabi). libc++ from the
NDK is a linker script that pulls in libandroid_support, but for
building libc++ itself, we need to explicitly add libandroid_support as
a dependency. Moreover, libc++ headers reference the functions provided
by libandroid_support, so it needs to be added as a public dependency.
Differential Revision: https://reviews.llvm.org/D73516
LLVM has moved to C++14, and the libc++ build should too.
C++14 is needed to provide constant initialization for certain global
objects.
I suspect this change may break some older GCC buildbots, and I'll clean
those up as they fall.
Louis Dionne