* Implements all of the discussed features:
- Links against common CAPI libraries that are self contained.
- Stops using the 'python/' directory at the root for everything, opening the namespace up for multiple projects to embed the MLIR python API.
- Separates declaration of sources (py and C++) needed to build the extension from building, allowing external projects to build custom assemblies from core parts of the API.
- Makes the core python API relocatable (i.e. it could be embedded as something like 'npcomp.ir', 'npcomp.dialects', etc). Still a bit more to do to make it truly isolated but the main structural reset is done.
- When building statically, installed python packages are completely self contained, suitable for direct setup and upload to PyPi, et al.
- Lets external projects assemble their own CAPI common runtime library that all extensions use. No more possibilities for TypeID issues.
- Begins modularizing the API so that external projects that just include a piece pay only for what they use.
* I also rolled in a re-organization of the native libraries that matches how I was packaging these out of tree and is a better layering (i.e. all libraries go into a nested _mlir_libs package). There is some further cleanup that I resisted since it would have required source changes that I'd rather do in a followup once everything stabilizes.
* Note that I made a somewhat odd choice in choosing to recompile all extensions for each project they are included into (as opposed to compiling once and just linking). While not leveraged yet, this will let us set definitions controlling the namespacing of the extensions so that they can be made to not conflict across projects (with preprocessor definitions).
* This will be a relatively substantial breaking change for downstreams. I will handle the npcomp migration and will coordinate with the circt folks before landing. We should stage this and make sure it isn't causing problems before landing.
* Fixed a couple of absolute imports that were causing issues.
Differential Revision: https://reviews.llvm.org/D106520
libMLIRPublicAPI.so came into existence early when the Python and C-API were being co-developed because the Python extensions need a single DSO which exports the C-API to link against. It really should never have been exported as a mondo library in the first place, which has caused no end of problems in different linking modes, etc (i.e. the CAPI tests depended on it).
This patch does a mechanical move that:
* Makes the C-API tests link directly to their respective libraries.
* Creates a libMLIRPythonCAPI as part of the Python bindings which assemble to exact DSO that they need.
This has the effect that the C-API is no longer monolithic and can be subset and used piecemeal in a modular fashion, which is necessary for downstreams to only pay for what they use. There are additional, more fundamental changes planned for how the Python API is assembled which should make it more out of tree friendly, but this minimal first step is necessary to break the fragile dependency between the C-API and Python API.
Downstream actions required:
* If using the C-API and linking against MLIRPublicAPI, you must instead link against its constituent components. As a reference, the Python API dependencies are in lib/Bindings/Python/CMakeLists.txt and approximate the full set of dependencies available.
* If you have a Python API project that was previously linking against MLIRPublicAPI (i.e. to add its own C-API DSO), you will want to `s/MLIRPublicAPI/MLIRPythonCAPI/` and all should be as it was. There are larger changes coming in this area but this part is incremental.
Reviewed By: mehdi_amini
Differential Revision: https://reviews.llvm.org/D106369
This only exposes the ability to round-trip a textual pipeline at the
moment.
To exercise it, we also bind the libTransforms in a new Python extension. This
does not include any interesting bindings, but it includes all the
mechanism to add separate native extensions and load them dynamically.
As such passes in libTransforms are only registered after `import
mlir.transforms`.
To support this global registration, the TableGen backend is also
extended to bind to the C API the group registration for passes.
Reviewed By: stellaraccident
Differential Revision: https://reviews.llvm.org/D90819
Mehdi Amini