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
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
These are a part of the libc so linking these explicitly isn't necessary
and embedding these as deplibs causes link time error.
This issues was introduced in a9b5fff which changed how we emit deplibs.
Differential Revision: https://reviews.llvm.org/D71135
These seemed to have been used in the past but were since removed
by the add_compile_flags_if_supported functions that combine these
these checks and adding the flag, but the original checks were never
removed.
Differential Revision: https://reviews.llvm.org/D62566
llvm-svn: 362058
This fixes the issue introduced by r362048 where we always use
pragma comment(lib, ...) for dependent libraries when the compiler
is Clang, but older Clang versions don't support this pragma so
we need to check first if it's supported before using it.
llvm-svn: 362055
Instead of manually linking against libm/librt/libpthread, we should be
linking against libSystem on Apple platforms, and only that. libm and
libpthread are symlinks to libSystem anyway.
llvm-svn: 359808
The check_library_exists CMake uses a custom symbol definition. This
is a problem when checking for C library symbols because Clang
recognizes many of them as builtins, and returns the
-Wbuiltin-requires-header (or -Wincompatible-library-redeclaration)
error. When building with -Werror which is the default, this causes
the check_library_exists check fail making the build think that C
library isn't available.
To avoid this issue, we should use a symbol that isn't recognized by
Clang and wouldn't cause the same issue. __libc_start_main seems like
reasonable choice that fits the bill.
Differential Revision: https://reviews.llvm.org/D57142
llvm-svn: 352341
We're using -nodefaultlibs to avoid the dependency on C++ library
when using check_cxx_compiler_flag, and as such we cannot use
check_cxx_compiler_flag to check the availability of -nodefaultlibs
itself.
llvm-svn: 299711
When compiler-rt is requested, we should attempt to link compiler-rt
builtins library rather than gcc_s.
Differential Revision: https://reviews.llvm.org/D31617
llvm-svn: 299599
Summary:
mingw64 has lots of default libs that libc++ and its test programs
should link against.
With this patch, cmake now runs successfully with GCC on Windows.
Reviewers: mati865, EricWF
Subscribers: mgorny, cfe-commits
Differential Revision: https://reviews.llvm.org/D31518
llvm-svn: 299144
Hard code the defaults for Windows for the time being. The checks
really are always going to return the same value. Technically, the
pthread linkage is possible, however, it seems better to use the Win32
threading along with the external threading support that we have added.
llvm-svn: 290801
We're compiling libc++ with -nodefaultlibs, so we should also pass this
option during the configuration checks to ensure those checks are
consistent with the actual build.
The primary motivation here is to ease cross-compilation against a
non-standard set of C++ libraries. Previously, the configuration checks
would attempt to link against the standard C++ libraries, which would
cause link failures when cross-compiling, even though the actual library
link would go through correctly (because of the use of -nodefaultlibs
and explicitly specifying any needed libraries). This is more correct
even ignoring the motivation, however.
Patch by Shoaib Meenai!
llvm-svn: 280015
We're compiling libc++ with -nodefaultlibs, so we should also pass this option
during the configuration checks to ensure those checks are consistent with the
actual build.
The primary motivation here is to ease cross-compilation against a non-standard
set of C++ libraries. Previously, the configuration checks would attempt to link
against the standard C++ libraries, which would cause link failures when
cross-compiling, even though the actual library link would go through correctly
(because of the use of -nodefaultlibs and explicitly specifying any needed
libraries). This is more correct even ignoring the motivation, however.
Patch by Shoaib Meenai!
llvm-svn: 279584
This re-applies commit r260235. However, this time we add -gcc-toolchain
to the compiler's flags when the user has specified the LIBCXX_GCC_TOOLCHAIN
variable.
llvm-svn: 260515
This reverts commit r260235. It breaks LLVM's bootstrap when building
with a -gcc-toolchain and the system's gcc installation does not provide
the libatomic library and its headers. We should check whether
LIBCXX_GCC_TOOLCHAIN is set and adjust the flags accordingly.
llvm-svn: 260323
Summary:
This fixes the tests under std/atomics for 32-bit MIPS CPUs where the
8-byte atomic operations call into the libatomic library.
Reviewers: dsanders, mclow.lists, EricWF, jroelofs, joerg
Subscribers: cfe-commits
Differential Revision: http://reviews.llvm.org/D16613
llvm-svn: 260235
Summary:
This patch adds Sphinx based documentation to libc++. The goal is to make it easier to write documentation for libc++ since writing new documentation in HTML is cumbersome. This patch rewrites the main page for libc++ along with the instructions for using, building and testing libc++.
The built documentation can be found and reviewed here: http://efcs.ca/libcxx-docs
In order to build the sphinx documentation you need to specify the cmake options `-DLLVM_ENABLE_SPHINX=ON -DLIBCXX_INCLUDE_DOCS=ON`. This will add the makefile rule `docs-libcxx-html`.
Reviewers: chandlerc, mclow.lists, danalbert, jroelofs
Subscribers: silvas, cfe-commits
Differential Revision: http://reviews.llvm.org/D12129
llvm-svn: 245788
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
Summary:
This patch adds support for LLVM_USE_SANITIZER when being built in-tree and standalone.
This patch does the following things:
1. define the LLVM_USE_SANITIZER option to "" when being built standalone. This also helps show we support it.
2. Translate LLVM_USE_SANITIZER when standalone in a very similar way done in llvm/cmake/HandleLLVMOptions.cmake.
3. Add config.llvm_use_sanitizer to lit.site.cfg.in
4. Add code to translate config.llvm_use_sanitizer's value into the needed compile flags in lit.cfg.
Currently lit.cfg assumes that that the compiler supports '-fno-omit-frame-pointer' while CMakeLists.txt actually checks to see if its supported. We could pass this information to lit but I'm not sure its needed.
Reviewers: mclow.lists, danalbert
Reviewed By: danalbert
Subscribers: cfe-commits
Differential Revision: http://reviews.llvm.org/D4949
llvm-svn: 215872
Summary:
This patch does two things:
CMake Update:
- Add compiler flag checks for -std=c++11 and -std=c++1y and remove check for -std=c++0x.
- Add configuration option LIBCXX_ENABLE_CXX1Y to prevent/allow -std=c++1y from being chosen as the std version. LIBCXX_ENABLE_CXX1Y is set to OFF by default.
- if LIBCXX_ENABLE_CXX1Y is enabled then set LIBCXX_STD_VERSION to c++1y and fail if the compiler does not support -std=c++1y
- If c++1y is not enabled then use c++11 and fail if the compiler does not support c++11.
Lit Update:
- Update lit.site.cfg.in to capture LIBCXX_STD_VERSION information as config.std.
- Remove mentions of has_cxx0X configuration option.
- Check for `--param std=X' passed to lit on the command line.
- Choose the std for the tests either from command line parameter or (if it doesn't exist) the lit.site.cfg.
Reviewers: mclow.lists, danalbert
Reviewed By: danalbert
Subscribers: emaste, rnk, ajwong, danalbert, cfe-commits
Differential Revision: http://reviews.llvm.org/D4329
llvm-svn: 215802
This is unnecessary now that the flag handling has been fixed. The flags will
be added properly in the main CMakeLists.txt after the config-ix inclusion which
performs the required check.
llvm-svn: 203639
libcxx doesn't build with -Werror because of #warnings in its source
code. But when libcxx is built as an external LLVM project, it inherits
LLVM build flags, breaking the build if LLVM_ENABLE_WERROR is enabled.
llvm-svn: 191814
Louis Dionne