protobuf/protobuf.bzl
Andrew Harp 38f131fd8c Build protoc for host platform to enable cross-compilation.
This is necessary to run protoc on the host as a dependency for Android BUILD targets with Bazel.
2015-11-03 16:39:32 -05:00

289 lines
8.0 KiB
Python

# -*- mode: python; -*- PYTHON-PREPROCESSING-REQUIRED
def _GenDir(ctx):
if not ctx.attr.includes:
return ""
if not ctx.attr.includes[0]:
return ctx.label.package
if not ctx.label.package:
return ctx.attr.includes[0]
return ctx.label.package + '/' + ctx.attr.includes[0]
def _CcOuts(srcs):
return [s[:-len(".proto")] + ".pb.h" for s in srcs] + \
[s[:-len(".proto")] + ".pb.cc" for s in srcs]
def _PyOuts(srcs):
return [s[:-len(".proto")] + "_pb2.py" for s in srcs]
def _RelativeOutputPath(path, include):
if include == None:
return path
if not path.startswith(include):
fail("Include path %s isn't part of the path %s." % (include, path))
if include and include[-1] != '/':
include = include + '/'
path = path[len(include):]
if not path.startswith(PACKAGE_NAME):
fail("The package %s is not within the path %s" % (PACKAGE_NAME, path))
if not PACKAGE_NAME:
return path
return path[len(PACKAGE_NAME)+1:]
def _proto_gen_impl(ctx):
"""General implementation for generating protos"""
srcs = ctx.files.srcs
deps = []
deps += ctx.files.srcs
gen_dir = _GenDir(ctx)
if gen_dir:
import_flags = ["-I" + gen_dir]
else:
import_flags = ["-I."]
for dep in ctx.attr.deps:
import_flags += dep.proto.import_flags
deps += dep.proto.deps
args = []
if ctx.attr.gen_cc:
args += ["--cpp_out=" + ctx.var["GENDIR"] + "/" + gen_dir]
if ctx.attr.gen_py:
args += ["--python_out=" + ctx.var["GENDIR"] + "/" + gen_dir]
if args:
ctx.action(
inputs=srcs + deps,
outputs=ctx.outputs.outs,
arguments=args + import_flags + [s.path for s in srcs],
executable=ctx.executable.protoc,
)
return struct(
proto=struct(
srcs=srcs,
import_flags=import_flags,
deps=deps,
),
)
_proto_gen = rule(
attrs = {
"srcs": attr.label_list(allow_files = True),
"deps": attr.label_list(providers = ["proto"]),
"includes": attr.string_list(),
"protoc": attr.label(
cfg = HOST_CFG,
executable = True,
single_file = True,
mandatory = True,
),
"gen_cc": attr.bool(),
"gen_py": attr.bool(),
"outs": attr.output_list(),
},
output_to_genfiles = True,
implementation = _proto_gen_impl,
)
def cc_proto_library(
name,
srcs=[],
deps=[],
cc_libs=[],
include=None,
protoc="//google/protobuf:protoc",
internal_bootstrap_hack=False,
default_runtime="//google/protobuf:protobuf",
**kargs):
"""Bazel rule to create a C++ protobuf library from proto source files
NOTE: the rule is only an internal workaround to generate protos. The
interface may change and the rule may be removed when bazel has introduced
the native rule.
Args:
name: the name of the cc_proto_library.
srcs: the .proto files of the cc_proto_library.
deps: a list of dependency labels; must be cc_proto_library.
cc_libs: a list of other cc_library targets depended by the generated
cc_library.
include: a string indicating the include path of the .proto files.
protoc: the label of the protocol compiler to generate the sources.
internal_bootstrap_hack: a flag indicate the cc_proto_library is used only
for bootstraping. When it is set to True, no files will be generated.
The rule will simply be a provider for .proto files, so that other
cc_proto_library can depend on it.
default_runtime: the implicitly default runtime which will be depended on by
the generated cc_library target.
**kargs: other keyword arguments that are passed to cc_library.
"""
includes = []
if include != None:
includes = [include]
if internal_bootstrap_hack:
# For pre-checked-in generated files, we add the internal_bootstrap_hack
# which will skip the codegen action.
_proto_gen(
name=name + "_genproto",
srcs=srcs,
deps=[s + "_genproto" for s in deps],
includes=includes,
protoc=protoc,
)
# An empty cc_library to make rule dependency consistent.
native.cc_library(
name=name,
**kargs)
return
outs = _CcOuts(srcs)
_proto_gen(
name=name + "_genproto",
srcs=srcs,
deps=[s + "_genproto" for s in deps],
includes=includes,
protoc=protoc,
gen_cc=1,
outs=outs,
)
if default_runtime and not default_runtime in cc_libs:
cc_libs += [default_runtime]
native.cc_library(
name=name,
srcs=outs,
deps=cc_libs + deps,
includes=includes,
**kargs)
def internal_copied_filegroup(
name,
srcs,
include,
**kargs):
"""Bazel rule to fix sources file to workaround with python path issues.
Args:
name: the name of the internal_copied_filegroup rule, which will be the
name of the generated filegroup.
srcs: the source files to be copied.
include: the expected import root of the source.
**kargs: extra arguments that will be passed into the filegroup.
"""
outs = [_RelativeOutputPath(s, include) for s in srcs]
native.genrule(
name=name+"_genrule",
srcs=srcs,
outs=outs,
cmd=" && ".join(["cp $(location %s) $(location %s)" %
(s, _RelativeOutputPath(s, include))
for s in srcs]))
native.filegroup(
name=name,
srcs=outs,
**kargs)
def py_proto_library(
name,
srcs=[],
deps=[],
py_libs=[],
py_extra_srcs=[],
include=None,
default_runtime="//google/protobuf:protobuf_python",
protoc="//google/protobuf:protoc",
**kargs):
"""Bazel rule to create a Python protobuf library from proto source files
NOTE: the rule is only an internal workaround to generate protos. The
interface may change and the rule may be removed when bazel has introduced
the native rule.
Args:
name: the name of the py_proto_library.
srcs: the .proto files of the py_proto_library.
deps: a list of dependency labels; must be py_proto_library.
py_libs: a list of other py_library targets depended by the generated
py_library.
py_extra_srcs: extra source files that will be added to the output
py_library. This attribute is used for internal bootstrapping.
include: a string indicating the include path of the .proto files.
default_runtime: the implicitly default runtime which will be depended on by
the generated py_library target.
protoc: the label of the protocol compiler to generate the sources.
**kargs: other keyword arguments that are passed to cc_library.
"""
outs = _PyOuts(srcs)
includes = []
if include != None:
includes = [include]
_proto_gen(
name=name + "_genproto",
srcs=srcs,
deps=[s + "_genproto" for s in deps],
includes=includes,
protoc=protoc,
gen_py=1,
outs=outs,
)
if include != None:
# Copy the output files to the desired location to make the import work.
internal_copied_filegroup_name=name + "_internal_copied_filegroup"
internal_copied_filegroup(
name=internal_copied_filegroup_name,
srcs=outs,
include=include)
outs=[internal_copied_filegroup_name]
if default_runtime and not default_runtime in py_libs + deps:
py_libs += [default_runtime]
native.py_library(
name=name,
srcs=outs+py_extra_srcs,
deps=py_libs+deps,
**kargs)
def internal_protobuf_py_tests(
name,
modules=[],
**kargs):
"""Bazel rules to create batch tests for protobuf internal.
Args:
name: the name of the rule.
modules: a list of modules for tests. The macro will create a py_test for
each of the parameter with the source "google/protobuf/%s.py"
kargs: extra parameters that will be passed into the py_test.
"""
for m in modules:
s = _RelativeOutputPath(
"python/google/protobuf/internal/%s.py" % m, "python")
native.py_test(
name="py_%s" % m,
srcs=[s],
main=s,
**kargs)