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      1 # Copyright 2014 The Chromium Authors. All rights reserved.
      2 # Use of this source code is governed by a BSD-style license that can be
      3 # found in the LICENSE file.
      4 
      5 # Compile a protocol buffer.
      6 #
      7 # Protobuf parameters:
      8 #
      9 #   proto_in_dir (optional)
     10 #       The path to the directory containing the .proto files. If left out, it
     11 #       defaults to '.'.
     12 #
     13 #   proto_out_dir (optional)
     14 #       Specifies the path suffix that output files are generated under.
     15 #       Targets that gyp-depend on my_proto_lib will be able to include the
     16 #       resulting proto headers with an include like:
     17 #         #include "dir/for/my_proto_lib/foo.pb.h"
     18 #       If undefined, this defaults to matching the input directory.
     19 #
     20 #   cc_generator_options (optional)
     21 #       List of extra flags passed to the protocol compiler.  If you need to
     22 #       add an EXPORT macro to a protobuf's C++ header, set the
     23 #       'cc_generator_options' variable with the value:
     24 #       'dllexport_decl=FOO_EXPORT:' (note trailing colon).
     25 #
     26 #       It is likely you also need to #include a file for the above EXPORT
     27 #       macro to work. See cc_include.
     28 #
     29 #   cc_include (optional)
     30 #       String listing an extra include that should be passed.
     31 #       Example: cc_include = "foo/bar.h"
     32 #
     33 # Parameters for compiling the generated code:
     34 #
     35 #   defines (optional)
     36 #       Defines to supply to the source set that compiles the generated source
     37 #       code.
     38 #
     39 #   extra_configs (optional)
     40 #       A list of config labels that will be appended to the configs applying
     41 #       to the source set.
     42 #
     43 # Example:
     44 #  proto_library("mylib") {
     45 #    sources = [
     46 #      "foo.proto",
     47 #    ]
     48 #  }
     49 
     50 template("proto_library") {
     51   assert(defined(invoker.sources), "Need sources for proto_library")
     52 
     53   action_name = "${target_name}_gen"
     54   source_set_name = target_name
     55   action_foreach(action_name) {
     56     visibility = ":$source_set_name"
     57 
     58     script = "//tools/protoc_wrapper/protoc_wrapper.py"
     59 
     60     sources = invoker.sources
     61 
     62     # TODO(brettw) it would be better if this used the target gen dir.
     63     if (defined(invoker.proto_out_dir)) {
     64       proto_out_dir = invoker.proto_out_dir
     65     } else {
     66       # This computes the relative path inside the target_gen_dir that
     67       # we'd put the files in, which maps to the current directory path.
     68       # We'll insert "protoc_out" at the beginning for compatibility with GYP.
     69       proto_out_dir = rebase_path(target_gen_dir, root_gen_dir)
     70     }
     71     cc_dir = "$root_gen_dir/protoc_out/$proto_out_dir"
     72     py_dir = "$root_gen_dir/pyproto/$proto_out_dir"
     73 
     74     outputs = [
     75       "$py_dir/{{source_name_part}}_pb2.py",
     76       "$cc_dir/{{source_name_part}}.pb.cc",
     77       "$cc_dir/{{source_name_part}}.pb.h",
     78     ]
     79 
     80     args = []
     81     if (defined(invoker.cc_include)) {
     82       args += [ "--include", invoker.cc_include ]
     83     }
     84 
     85     args += [
     86       "--protobuf",
     87       rebase_path("$cc_dir/{{source_name_part}}.pb.h", root_build_dir),
     88     ]
     89 
     90     if (defined(invoker.proto_in_dir)) {
     91       proto_in_dir = invoker.proto_in_dir
     92     } else {
     93       # Extract the current source dir.
     94       proto_in_dir = get_label_info(":$target_name", "dir")
     95     }
     96     args += [
     97       "--proto-in-dir",
     98       rebase_path(proto_in_dir, root_build_dir),
     99       "--proto-in-file", "{{source_file_part}}",
    100       # TODO(brettw) support system protobuf compiler.
    101       "--use-system-protobuf=0",
    102     ]
    103 
    104     protoc_label = "//third_party/protobuf:protoc($host_toolchain)"
    105     args += [
    106       "--", 
    107       # Prepend with "./" so this will never pick up the system one (normally
    108       # when not cross-compiling, protoc's output directory will be the same
    109       # as the build dir, so the relative location will be empty.
    110       "./" + rebase_path(get_label_info(protoc_label, "root_out_dir") +
    111              "/protoc", root_build_dir),
    112     ]
    113 
    114     # If passed cc_generator_options should end in a colon, which will separate
    115     # it from the directory when we concatenate them. The proto compiler
    116     # understands this syntax.
    117     if (defined(invoker.cc_generator_options)) {
    118       cc_generator_options = invoker.cc_generator_options
    119     } else {
    120       cc_generator_options = ""
    121     }
    122     args += [
    123       "--cpp_out", cc_generator_options + rebase_path(cc_dir, root_build_dir),
    124       "--python_out", rebase_path(py_dir, root_build_dir),
    125     ]
    126 
    127     deps = [ protoc_label ]
    128   }
    129 
    130   source_set(target_name) {
    131     if (defined(invoker.visibility)) {
    132       visibility = invoker.visibility
    133     }
    134 
    135     sources = get_target_outputs(":$action_name")
    136 
    137     if (defined(invoker.defines)) {
    138       defines = invoker.defines
    139     }
    140     if (defined(invoker.extra_configs)) {
    141       configs += invoker.extra_configs
    142     }
    143 
    144     direct_dependent_configs = [ "//third_party/protobuf:using_proto" ]
    145 
    146     deps = [
    147       ":$action_name",
    148       "//third_party/protobuf:protobuf_lite",
    149     ]
    150 
    151     # The generated headers reference headers within protobuf_lite, so
    152     # dependencies must be able to find those headers too.
    153     forward_dependent_configs_from = [ "//third_party/protobuf:protobuf_lite" ]
    154   }
    155 }
    156