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-rw-r--r--protobuf.bzl127
1 files changed, 127 insertions, 0 deletions
diff --git a/protobuf.bzl b/protobuf.bzl
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+# -*- mode: python; -*- PYTHON-PREPROCESSING-REQUIRED
+
+def _gen_dir(ctx):
+ if not ctx.attr.include:
+ return ctx.label.package
+ if not ctx.label.package:
+ return ctx.attr.include
+ return ctx.label.package + '/' + ctx.attr.include
+
+def _cc_outs(srcs):
+ return [s[:-len(".proto")] + ".pb.h" for s in srcs] + \
+ [s[:-len(".proto")] + ".pb.cc" for s in srcs]
+
+def _py_outs(srcs):
+ return [s[:-len(".proto")] + "_pb2.py" for s in srcs]
+
+def _proto_gen_impl(ctx):
+ """General implementation for generating protos"""
+ srcs = ctx.files.srcs
+ deps = []
+ deps += ctx.files.srcs
+ gen_dir = _gen_dir(ctx)
+ import_flags = ["-I" + gen_dir]
+ 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"]),
+ "include": attr.string(),
+ "protoc": attr.label(
+ 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="",
+ protoc=":protoc",
+ internal_bootstrap_hack=False,
+ **kargs):
+ """Bazel rule to create a C++ protobuf library from proto source files
+
+ 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.
+ **kargs: other keyword arguments that are passed to cc_library.
+
+ """
+
+ 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],
+ include=include,
+ protoc=protoc,
+ )
+ # An empty cc_library to make rule dependency consistent.
+ native.cc_library(
+ name=name,
+ **kargs)
+ return
+
+ outs = _cc_outs(srcs)
+ _proto_gen(
+ name=name + "_genproto",
+ srcs=srcs,
+ deps=[s + "_genproto" for s in deps],
+ include=include,
+ protoc=protoc,
+ gen_cc=1,
+ outs=outs,
+ )
+
+ native.cc_library(
+ name=name,
+ srcs=outs,
+ deps=cc_libs + deps,
+ includes=[include],
+ **kargs)