aboutsummaryrefslogtreecommitdiff
path: root/protobuf.bzl
blob: b83f7f5a52b72096329e158af1ab5b377431ffe4 (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
# -*- mode: python; -*- PYTHON-PREPROCESSING-REQUIRED

def _gen_dir(ctx):
  if ctx.attr.include == None:
    return ""
  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=None,
        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,
  )

  includes = []
  if include != None:
    includes = [include]

  native.cc_library(
      name=name,
      srcs=outs,
      deps=cc_libs + deps,
      includes=includes,
      **kargs)