diff options
Diffstat (limited to 'bazel')
-rw-r--r-- | bazel/cython_library.bzl | 74 |
1 files changed, 74 insertions, 0 deletions
diff --git a/bazel/cython_library.bzl b/bazel/cython_library.bzl new file mode 100644 index 0000000000..48b41d74e8 --- /dev/null +++ b/bazel/cython_library.bzl @@ -0,0 +1,74 @@ +"""Custom rules for gRPC Python""" + + +# Adapted with modifications from +# tensorflow/tensorflow/core/platform/default/build_config.bzl +# Native Bazel rules don't exist yet to compile Cython code, but rules have +# been written at cython/cython and tensorflow/tensorflow. We branch from +# Tensorflow's version as it is more actively maintained and works for gRPC +# Python's needs. +def pyx_library(name, deps=[], py_deps=[], srcs=[], **kwargs): + """Compiles a group of .pyx / .pxd / .py files. + + First runs Cython to create .cpp files for each input .pyx or .py + .pxd + pair. Then builds a shared object for each, passing "deps" to each cc_binary + rule (includes Python headers by default). Finally, creates a py_library rule + with the shared objects and any pure Python "srcs", with py_deps as its + dependencies; the shared objects can be imported like normal Python files. + + Args: + name: Name for the rule. + deps: C/C++ dependencies of the Cython (e.g. Numpy headers). + py_deps: Pure Python dependencies of the final library. + srcs: .py, .pyx, or .pxd files to either compile or pass through. + **kwargs: Extra keyword arguments passed to the py_library. + """ + # First filter out files that should be run compiled vs. passed through. + py_srcs = [] + pyx_srcs = [] + pxd_srcs = [] + for src in srcs: + if src.endswith(".pyx") or (src.endswith(".py") and + src[:-3] + ".pxd" in srcs): + pyx_srcs.append(src) + elif src.endswith(".py"): + py_srcs.append(src) + else: + pxd_srcs.append(src) + if src.endswith("__init__.py"): + pxd_srcs.append(src) + + # Invoke cython to produce the shared object libraries. + for filename in pyx_srcs: + native.genrule( + name=filename + "_cython_translation", + srcs=[filename], + outs=[filename.split(".")[0] + ".cpp"], + # Optionally use PYTHON_BIN_PATH on Linux platforms so that python 3 + # works. Windows has issues with cython_binary so skip PYTHON_BIN_PATH. + cmd= + "PYTHONHASHSEED=0 $(location @cython//:cython_binary) --cplus $(SRCS) --output-file $(OUTS)", + tools=["@cython//:cython_binary"] + pxd_srcs, + ) + + shared_objects = [] + for src in pyx_srcs: + stem = src.split(".")[0] + shared_object_name = stem + ".so" + native.cc_binary( + name=shared_object_name, + srcs=[stem + ".cpp"], + deps=deps + ["@local_config_python//:python_headers"], + linkshared=1, + ) + shared_objects.append(shared_object_name) + + # Now create a py_library with these shared objects as data. + native.py_library( + name=name, + srcs=py_srcs, + deps=py_deps, + srcs_version="PY2AND3", + data=shared_objects, + **kwargs) + |