Avoid repeating CMake checks across runtimes by unifying names of
variables used for results to leverage CMake caching.
Differential Revision: https://reviews.llvm.org/D110005
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
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
Summary:
Instead of populating the global LIBCXX_LIBRARIES, we use the link-time
dependency management built into CMake to propagate link flags. This
leads to a cleaner and easier-to-follow build.
Reviewers: phosek, smeenai, EricWF
Subscribers: mgorny, christof, jkorous, dexonsmith, jfb, mstorsjo, libcxx-commits
Tags: #libc
Differential Revision: https://reviews.llvm.org/D60969
llvm-svn: 359571
Some linker libraries are only needed for shared libc++, some only
for static libc++, combining these together in LIBCXX_LIBRARIES and
LIBCXX_INTERFACE_LIBRARIES can introduce unnecessary dependencies.
This changes splits those up into LIBCXX_SHARED_LIBRARIES and
LIBCXX_STATIC_LIBRARIES matching what libc++abi already does.
Differential Revision: https://reviews.llvm.org/D57872
llvm-svn: 358614
This patch adds the cxx-benchmark-unittests target so we can start
getting test coverage on the benchmarks, including building with
sanitizers. Because we're only looking for test-coverage, the benchmarks
run for the shortest time possible, and in parallel.
The target is excluded from all by default. It only
builds and runs the libcxx configurations of the benchmarks, and not
any versions built against the systems native standard library.
llvm-svn: 346811
Although libc++ doesn't yet support Windows we still have Windows
builders to track our progress.
Currently the clang-cl configuration seems broken because it doesn't
support -std=c++11 and instead requires /std:c++11. This patch attempts
to fix this.
llvm-svn: 343431
Summary:
This patch attempts to fix the libc++ build/link so that it doesn't use an default C++ libraries on Windows. This is needed to prevent linking to MSVC's STL library.
Additionally this patch changes libc++ so that it is always linked with the non-debug DLL's (e.g. `/MD`). This is needed so that the test suite can correctly link the same libraries without needing to know which configuration `c++.dll` was linked with.
Reviewers: compnerd, rnk, majnemer, kimgr, awson, halyavin, smeenai
Subscribers: cfe-commits, mgorny
Differential Revision: https://reviews.llvm.org/D28441
llvm-svn: 292001
Summary:
This patch changes the libc++ CMake so that it adds certain target flags like '-m32' or '--gcc-toolchain' before including config-ix.cmake.
Since these flags can affect things like check_library_exists([...]) they needed to be added before the tests are performed.
This patch fixes:
https://llvm.org/bugs/show_bug.cgi?id=24322
Reviewers: danalbert, jroelofs, bcraig, compnerd
Subscribers: cfe-commits
Differential Revision: http://reviews.llvm.org/D20887
llvm-svn: 271460
Summary:
Currently libc++experimental builds with C++11. This patch changes that to C++14 when supported by the compiler. Although nothing currently requires C++14 the upcoming <experimental/memory_resource> implementation would benefit from it. [1]
Note that libc++.so continues to build with C++11 and is unaffected by this change.
[1] <experimental/memory_resource> provides global resources which must exist for the entire lifetime of the program. In order to ensure that a global resource can be used during program termination there destructors must never be invoked. The only way to do this, while also allowing "constant initialization", is to use a C++14 union.
Reviewers: mclow.lists
Subscribers: pete, cfe-commits
Differential Revision: http://reviews.llvm.org/D19992
llvm-svn: 269070
C++ macros and CMake options that specify the default ABI version of
the library, and can be overridden to pick up new ABI-changing
features.
llvm-svn: 250254
Summary:
Hi all,
This patch is a successor to D11963. However it has changed dramatically and I felt it would be best to start a new review thread.
Please read the design documentation added in this patch for a description of how it works.
Reviewers: mclow.lists, danalbert, jroelofs, EricWF
Subscribers: vkalintiris, rnk, ed, espositofulvio, asl, eugenis, cfe-commits
Differential Revision: http://reviews.llvm.org/D13407
llvm-svn: 250235
This patch adds the working parts of r243503. The difference with this patch
is that it doesn't include the HandleLLVMOptions.cmake file.
llvm-svn: 243698
This change was reverted in r243550 because it broke clang-format builds
(see PR24306).
This patch recommits a fixed version of the original.
llvm-svn: 243574
Summary:
This patch contains the following changes:
1. Require that libc++ can find a LLVM source directory. This is done the same way as `libc++abi` currently does.
2. Cleanup ugly configuration code in CMakeLists.txt by using `add_flags`, `add_flags_if`, and `add_flags_if_supported` macros.
The goals for this patch are:
1. Help libc++ be more consistent with how LLVM handles CMake options (see PR23670 PR23671).
2. Make it easier to use sanitizers using the `LLVM_USE_SANITIZER` option.
3. Make libc++'s CMakeLists.txt file easier to understand and change.
4. Move towards allowing libc++ to create Sphinx documentation (see http://efcs.ca/libcxx-docs).
5. Move towards allowing libc++ to use other LLVM utilities such as `not` and `FileCheck`.
Reviewers: mclow.lists, jroelofs, danalbert
Subscribers: cfe-commits
Differential Revision: http://reviews.llvm.org/D11308
llvm-svn: 243503
Petr Hosek