commit a3e97f1f74e51524fbd2f2fc27579b8bf15e68f2
author Stella Laurenzo <stellaraccident@gmail.com> Sat Dec 05 23:29:13 2020 -0800
committer Stella Laurenzo <stellaraccident@gmail.com> Mon Dec 07 15:10:32 2020 -0800
tree f8dacac9910ba8b816738e6e65070cfc7f7738bb
parent e5faf044ae469a6f15114c54aec05bfebcf9127b

Step 4/n: Integrate TensorFlow compiler build and tests into CMake.

* New option: 'IREE_BUILD_TENSORFLOW_COMPILER'
* Adds some cmake hackery to find and configure bazel, scoping it under the build directory.
* Adds an iree_add_bazel_invocation() function that executes bazel and creates cmake targets for some built executables.
* Adds the cmake target 'integrations_iree_tensorflow_importers' as a bazel invocation.
* Wires up the build for pyiree.tools.tf to link the binary from the bazel side. The result is a built bindings/python directory that can be used for tests and such with no further build required (or deployed directly).
* Once I'm done with this transition, we can completely remove all of the python building from bazel, likely just replacing tests with a shell script runner, since they can just run standalone.
* Also had to fix some issues with the python config (it wasn't detecting virtual envs properly due to using the old FindPython vars).
* Added yet another hack to run_lit.sh because with bazel's out directory living in the build directory, it was taking 2m+ to scan files for things to add to the path. We shouldn't have been doing that, but also... Bazel, WTF?
* Note that old build/tests of the integrations directory were double building almost everything because Bazel was differentiating between objects bound for binaries and for shared libraries. In addition, since it included the complete IREE compiler, it was building all of LLVM.
* In the new world, we only build one static binary, and since it is just the frontend, the amount of things it needs to compile from LLVM are minimal. Most of the time is in compiling eigen kernels.
* This will probably take some tweaking before it is ready for prime time.

Stats:

Clean build:
  configure: ~1m
  ninja build: ~10m (includes TF)
  ctest -E 'vulkan|benchmark': 14s (includes new TF tests but not the whole e2e directory yet)

On a rebuild with CCache and Bazel's disk cache enabled from the above, a rebuild of everything took 18s.