forked from OSchip/llvm-project
f7a33090a9
We held off on this before as `LLVM_LIBDIR_SUFFIX` conflicted with it. Now we return this. `LLVM_LIBDIR_SUFFIX` is kept as a deprecated way to set `CMAKE_INSTALL_LIBDIR`. The other `*_LIBDIR_SUFFIX` are just removed entirely. I imagine this is too potentially-breaking to make LLVM 15. That's fine. I have a more minimal version of this in the disto (NixOS) patches for LLVM 15 (like previous versions). This more expansive version I will test harder after the release is cut. Reviewed By: sebastian-ne, ldionne, #libc, #libc_abi Differential Revision: https://reviews.llvm.org/D130586 |
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| .. | ||
| Modules | ||
| README.rst | ||
README.rst
=======================
LLVM Common CMake Utils
=======================
What goes here
--------------
These are CMake modules to be shared between LLVM projects strictly at build
time. In other words, they must not be included from an installed CMake module,
such as the ``Add*.cmake`` ones. Modules that are reachable from installed
modules should instead go in ``${project}/cmake/modules`` of the most upstream
project that uses them.
The advantage of not putting these modules in an existing location like
``llvm/cmake/modules`` is two-fold:
- Since they are not installed, we don't have to worry about any out-of-tree
downstream usage, and thus there is no need for stability.
- Since they are available as part of the source at build-time, we don't have
to do the usual stand-alone vs combined-build dances, avoiding much
complexity.
How to use
----------
For tools, please do:
.. code-block:: cmake
if(NOT DEFINED LLVM_COMMON_CMAKE_UTILS)
set(LLVM_COMMON_CMAKE_UTILS ${CMAKE_CURRENT_SOURCE_DIR}/../cmake)
endif()
# Add path for custom modules.
list(INSERT CMAKE_MODULE_PATH 0
# project-specific module dirs first
"${LLVM_COMMON_CMAKE_UTILS}/Modules"
)
Notes:
- The ``if(NOT DEFINED ...)`` guard is there because in combined builds, LLVM
will set this variable. This is useful for legacy builds where projects are
found in ``llvm/tools`` instead.
- ``INSERT ... 0`` ensures these new entries are prepended to the front of the
module path, so nothing might shadow them by mistake.
For runtime libs, we skip the ``if(NOT DEFINED`` part:
.. code-block:: cmake
set(LLVM_COMMON_CMAKE_UTILS ${CMAKE_CURRENT_SOURCE_DIR}/../cmake)
... # same as before
If ``llvm/tools`` legacy-style combined builds are deprecated, we should then
skip it everywhere, bringing the tools and runtimes boilerplate back in line.