1# Copyright 2015 gRPC authors.
2#
3# Licensed under the Apache License, Version 2.0 (the "License");
4# you may not use this file except in compliance with the License.
5# You may obtain a copy of the License at
6#
7#     http://www.apache.org/licenses/LICENSE-2.0
8#
9# Unless required by applicable law or agreed to in writing, software
10# distributed under the License is distributed on an "AS IS" BASIS,
11# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
12# See the License for the specific language governing permissions and
13# limitations under the License.
14
15"""
16Bazel macros to declare gRPC libraries automatically generated from proto files.
17
18This file declares two macros:
19- objc_proto_library
20- objc_grpc_library
21"""
22
23def _lower_underscore_to_upper_camel(str):
24    humps = []
25    for hump in str.split("_"):
26        humps.append(hump[0].upper() + hump[1:])
27    return "".join(humps)
28
29def _file_to_upper_camel(src):
30    elements = src.rpartition("/")
31    upper_camel = _lower_underscore_to_upper_camel(elements[-1])
32    return "".join(elements[:-1] + [upper_camel])
33
34def _file_with_extension(src, ext):
35    elements = src.rpartition("/")
36    basename = elements[-1].partition(".")[0]
37    return "".join(elements[:-1] + [basename, ext])
38
39def _protoc_invocation(srcs, flags):
40    """Returns a CLI command to invoke protoc.
41
42    Uses the given sources and flags. Suitable for use in a genrule.
43    """
44    protoc_command = "$(location //external:protoc) -I . "
45    srcs_params = ""
46    for src in srcs:
47        srcs_params += " $(location %s)" % (src)
48    return protoc_command + flags + srcs_params
49
50def objc_proto_library(name, srcs, visibility = None):
51    """Declares an objc_library for the code generated by protoc.
52
53    Uses the given proto sources. This generated code doesn't include proto
54    services.
55
56    Args:
57      name: The name of the library.
58      srcs: A list of .proto file sources.
59      visibility: The visibility label to apply to the target.
60    """
61    h_files = []
62    m_files = []
63    for src in srcs:
64        src = _file_to_upper_camel(src)
65        h_files.append(_file_with_extension(src, ".pbobjc.h"))
66        m_files.append(_file_with_extension(src, ".pbobjc.m"))
67
68    protoc_flags = "--objc_out=$(GENDIR)"
69
70    native.genrule(
71        name = name + "_codegen",
72        srcs = srcs + ["//external:protoc"],
73        outs = h_files + m_files,
74        cmd = _protoc_invocation(srcs, protoc_flags),
75    )
76    native.objc_library(
77        name = name,
78        hdrs = h_files,
79        includes = ["."],
80        non_arc_srcs = m_files,
81        deps = ["//external:protobuf_objc"],
82        visibility = visibility,
83    )
84
85def objc_grpc_library(name, services, other_messages, visibility = None):
86    """Declares an objc_library for the code generated by the gRPC ObjC plugin.
87
88    The generated code does not include the services of the files in other_messages.
89
90    Args:
91      name: The name of the library.
92      services: The .proto files from which to generate the library.
93      other_messages: A list of .proto files containing messages needed for the library.
94      visibility: The visibility label to apply to the library.
95    """
96    objc_proto_library(name + "_messages", services + other_messages)
97
98    h_files = []
99    m_files = []
100    for src in services:
101        src = _file_to_upper_camel(src)
102        h_files.append(_file_with_extension(src, ".pbrpc.h"))
103        m_files.append(_file_with_extension(src, ".pbrpc.m"))
104
105    protoc_flags = ("--grpc_out=$(GENDIR) --plugin=" +
106                    "protoc-gen-grpc=$(location //external:grpc_protoc_plugin_objc)")
107
108    native.genrule(
109        name = name + "_codegen",
110        srcs = services + [
111            "//external:grpc_protoc_plugin_objc",
112            "//external:protoc",
113        ],
114        outs = h_files + m_files,
115        cmd = _protoc_invocation(services, protoc_flags),
116    )
117    native.objc_library(
118        name = name,
119        hdrs = h_files,
120        includes = ["."],
121        srcs = m_files,
122        deps = [
123            ":" + name + "_messages",
124            "//external:proto_objc_rpc",
125        ],
126        visibility = visibility,
127    )
128