commit 69c4cab1af7b4b8d882336aa015252b8623fffda
author Stella Laurenzo <stellaraccident@gmail.com> Thu Nov 11 17:31:39 2021 -0800
committer Copybara-Service <copybara-worker@google.com> Thu Nov 11 18:06:16 2021 -0800
tree 0cdf64e0ae026e7f77631e155eac6319817f52c4
parent e74005fca5eaad4a22c3823d5e3d211519c16922

[mlir] Allow out-of-tree python building from installed MLIR.

* Depends on D111504, which provides the boilerplate for building aggregate shared libraries from installed MLIR.
* Adds a full-fledged Python example dialect and tests to the Standalone example (need to do a bit of tweaking in the top level CMake and lit tests to adapt better to if not building with Python enabled).
* Rips out remnants of custom extension building in favor of `pybind11_add_module` which does the right thing.
* Makes python and extension sources installable (outputs to src/python/${name} in the install tree): Both Python and C++ extension sources get installed as downstreams need all of this in order to build a derived version of the API.
* Exports sources targets (with our properties that make everything work) by converting them to INTERFACE libraries (which have export support), as recommended for the forseeable future by CMake devs. Renames custom properties to start with lower-case letter, as also recommended/required (groan).
* Adds a ROOT_DIR argument to `declare_mlir_python_extension` since now all C++ sources for an extension must be under the same directory (to line up at install time).
* Need to validate against a downstream or two and adjust, prior to submitting.

Downstreams will need to adapt by:

* Remove absolute paths from any SOURCES for `declare_mlir_python_extension` (I believe all downstreams are just using `${CMAKE_CURRENT_SOURCE_DIR}` here, which can just be ommitted). May need to set `ROOT_DIR` if not relative to the current source directory.
* To allow further downstreams to install/build, will need to make sure that all C++ extension headers are also listed under SOURCES for `declare_mlir_python_extension`.

Reviewed By: stephenneuendorffer, mikeurbach

Differential Revision: https://reviews.llvm.org/D111513

GitOrigin-RevId: c7be8b75399c727ec9e1ddc3f81510f284c65155