We previously had a few varied definitions of this floating around.
I had tried to make the one installed with LLVM handle all the cases, and then made the others use it, but this ran into issues with `HandleOutOfTreeLLVM` not working for compiler-rt, and also `CMAKE_EXE_LINKER_FLAGS` not working right without `CMP0056` set to the new behavior.
My compromise solution is this:
- No not completely deduplicate: the runtime libs will instead use a version that still exists as part of the internal and not installed common shared CMake utilities. This avoids `HandleOutOfTreeLLVM` or a workaround for compiler-rt.
- Continue to use `CMAKE_REQUIRED_FLAGS`, which effects compilation and linking. Maybe this is unnecessary, but it's safer to leave that as a future change. Also means we can avoid `CMP0056` for now, to try out later, which is good incrementality too.
- Call it `llvm_check_compiler_linker_flag` since it, in fact is about both per its implementation (before and after this patch), so there is no name collision.
In the future, we might still enable CMP0056 and make compiler-rt work with HandleOutOfTreeLLVM, which case we delete `llvm_check_compiler_flag` and go back to the old way (as these are, in fact, linking related flags), but that I leave for someone else as future work.
The original issue was reported to me in https://reviews.llvm.org/D116521#3248117 as
D116521 made clang and LLVM use the common cmake utils.
Reviewed By: sebastian-ne, phosek, #libunwind, #libc, #libc_abi, ldionne
Differential Revision: https://reviews.llvm.org/D117537
We previously had a few varied definitions of this floating around. I made the one installed with LLVM handle all the cases, and then made the others use it.
This issue was reported to me in https://reviews.llvm.org/D116521#3248117 as
D116521 made clang and llvm use the common cmake utils.
Reviewed By: sebastian-ne, phosek, #libunwind, #libc, #libc_abi, ldionne
Differential Revision: https://reviews.llvm.org/D117537
In D116472 we created conditionally defined variables for the tools to
unbreak the legacy build where they are in `llvm/tools`.
The runtimes are not tools, so that flexibility doesn't matter. Still,
it might be nice to define (unconditionally) and use the variable for
the runtimes simply to make the code a bit clearer and document what is
going on.
Also, consistently put project dirs at the beginning, not end of `CMAKE_MODULE_PATH`. This ensures they will properly shadow similarly named stuff that happens to be later on the path.
Reviewed By: mstorsjo, #libunwind, #libc, #libc_abi, ldionne
Differential Revision: https://reviews.llvm.org/D116477
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.
Since the previous attempt, this no longer uses
llvm_enable_language_nolink (and thus doesn't set
CMAKE_TRY_COMPILE_TARGET_TYPE=STATIC_LIBRARY during the compiler
sanity checks). Setting CMAKE_TRY_COMPILE_TARGET_TYPE=STATIC_LIBRARY
during compiler sanity checks makes cmake not learn about some
aspects of the compiler, which can make further find_library or
find_package fail. This caused OpenMP to not detect libelf and libffi,
disabling some OpenMP target plugins.
Instead, require the caller to set CMAKE_{C,CXX}_COMPILER_WORKS=YES
when building in a configuration with an incomplete toolchain.
Differential Revision: https://reviews.llvm.org/D113253
This reverts commit 317dc31e53.
After that change, OpenMP doesn't find dependencies in the host
system (it fails do find e.g. /usr/lib/x86_64-linux-gnu/libelf.so
which it found before), which causes some OpenMP target offloading
plugins to not be found. This doesn't break the build, but just
causes the AMDGPU OpenMP target plugin to be omitted. See
https://reviews.llvm.org/D113253#3181934 for the report of this
issue.
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.
Reapplying this after
db32c4f456, which should fix the issues
that were reported last time this was applied.
Differential Revision: https://reviews.llvm.org/D113253
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
5beec6fb04 added LLVM_DEFAULT_TARGET_TRIPLE to the runtimes build with
a comment, however I believe that comment had been copied from the LLVM
build tree. In the context of the runtimes, LLVM_DEFAULT_TARGET_TRIPLE
is used to set what targets we are building for, not the target for which
we "generate code".
Differential Revision: https://reviews.llvm.org/D114007
This reverts commit e7568b68da and relands
c6f7b720ec.
The culprit was: missed that libc also had a dependency on one of the
copies of `google-benchmark`
Also opportunistically fixed indentation from prev. change.
Differential Revision: https://reviews.llvm.org/D112012
under third-party
This change:
- moves the libcxx copy of `google/benchmark` to
`third-party/benchmkark`
- points the 2 uses of the library (libcxx and llvm/utils) to this copy
We picked the licxx copy because it is the most up to date.
Differential Revision: https://reviews.llvm.org/D112012
This allows tests to tell if they're running natively.
Those tests are libcxxabi/test/native/arm-linux-eabi.
Which were running on Linaro's bots but became unsupported
when we switched to the runtimes build.
Reviewed By: #libc_abi, phosek
Differential Revision: https://reviews.llvm.org/D113663
Otherwise, the individual `check-cxx`, `check-cxxabi` and similar targets
will not know about `LLVM_LIT_ARGS`, and we'll end up running lit without
any argument.
Differential Revision: https://reviews.llvm.org/D112035
This commit makes the new "runtimes" build (with <monorepo>/runtimes as
the root of the CMake invocation) the default way of building libc++.
The other supported way of building libc++ is the "bootstrapping" build,
where `<monorepo>/llvm` is used as the root of the CMake invocation.
All other ways of building libc++ are deprecated effective immediately.
There should be no use-case for building libc++ that isn't supported by
one of these two builds, and the two new builds work on all environments
and are lightweight. They will also make it possible to greatly simplify
the build infrastructure of the runtimes, which is currently way too
convoluted.
Differential Revision: https://reviews.llvm.org/D111356
This way, we do not need to set LLVM_CMAKE_PATH to LLVM_CMAKE_DIR when (NOT LLVM_CONFIG_FOUND)
Reviewed By: #libc, ldionne
Differential Revision: https://reviews.llvm.org/D107717
Don't blindly assume they're supported - GCC doesn't support -nostdlib++.
The llvm-project/runtimes directory is supposed to allow building the
runtimes standalone from a newly built Clang, and thus should allow
building with other compilers too.
Differential Revision: https://reviews.llvm.org/D109719
If building by pointing cmake directly at the llvm-project/runtimes
directory, the llvm cmake package files (that provide e.g.
LLVM_BUILD_MAIN_SRC_DIR) aren't necessarily available. Instead just
use a path relative to the current source dir.
Differential Revision: https://reviews.llvm.org/D109717
`<var> STREQUAL ""` fails when `<var>` is unset which can be the
case when using runtimes as top-level build. Use `NOT` instead.
Differential Revision: https://reviews.llvm.org/D109570
These paths are needed when building with per-target runtime directories.
(It's possible to fix this by manually setting these when invoking
cmake, but one isn't supposed to need to do that.)
Also set LLVM_TOOLS_BINARY_DIR while touching this area (as it's
also unset in this case) even if it isn't specifically needed by the
per-target runtime configuration.
Fixed since previous attempt: Don't check if the runtimes directory
is the root of the CMake invocation; when the main LLVM CMake
build builds runtimes, it does invoke a sub-CMake with this directory
as the root too, just as if manually invoking CMake at the runtimes
directory. Instead check whether LLVM_TOOLS_BINARY_DIR was set and
whether find_package(LLVM) succeeded or not.
Differential Revision: https://reviews.llvm.org/D107895
These paths are needed when building with per-target runtime directories.
(It's possible to fix this by manually setting these when invoking
cmake, but one isn't supposed to need to do that.)
Also set LLVM_TOOLS_BINARY_DIR while touching this area (as it's
also unset in this case) even if it isn't specifically needed by the
per-target runtime configuration.
Differential Revision: https://reviews.llvm.org/D107895
compiler-rt needs to use standalone build because of the assumptions
made by its build, but other runtimes can use non-standalone build.
Differential Revision: https://reviews.llvm.org/D97575
compiler-rt needs to use standalone build because of the assumptions
made by its build, but other runtimes can use non-standalone build.
Differential Revision: https://reviews.llvm.org/D97575
If the host compiler is MSVC or clang-cl, then the compiler used to
buidl the runtimes will be clang-cl, and it doesn't support either of
those flags.
Worse, because -isystem is a space separated flag, it causes all cmake
try_compile tests to fail, so none of the -Wno-* flags make it to the
compiler in libcxx. I noticed that we weren't passing
-Wno-user-defined-literals to clang-cl and were getting warnings in the
build, and this fixes that for me.
Differential Revision: https://reviews.llvm.org/D94817
Previously, llvm/runtimes/CMakeLists.txt played two different roles:
1. host side which could used to set up the build of runtimes for
different targets in the right order;
2. target side to build the runtimes for the specified target.
This change splits llvm/runtimes/CMakeLists.txt and moves the target
side to runtimes/CMakeLists laying down the foundation for the "A vision
for building the runtimes" proposal. From the user perspective, there
shouldn't be any visible difference at the moment.
Differential Revision: https://reviews.llvm.org/D93408
John Ericson