third_party/libprotobuf-mutator/BUILD.gn

# Copyright 2020 The Chromium Authors. All rights reserved.
# Use of this source code is governed by a BSD-style license that can be
# found in the LICENSE file.

import("//build_overrides/build.gni")
import("//testing/libfuzzer/fuzzer_test.gni")
import("//third_party/libprotobuf-mutator/fuzzable_proto_library.gni")

config("include_config") {
  include_dirs = [ "src/" ]
}

source_set("libprotobuf-mutator") {
  testonly = true

  configs += [ ":include_config" ]

  public_configs = [ ":include_config" ]
  sources = [
    "src/src/binary_format.cc",
    "src/src/libfuzzer/libfuzzer_macro.cc",
    "src/src/libfuzzer/libfuzzer_mutator.cc",
    "src/src/mutator.cc",
    "src/src/text_format.cc",
    "src/src/utf8_fix.cc",
  ]

  # Allow users of LPM to use protobuf reflection and other features from
  # protobuf_full.
  public_deps = [ "//third_party/protobuf:protobuf_full" ]
}

# This protoc plugin, like the compiler, should only be built for the host
# architecture.
if (current_toolchain == host_toolchain) {
  # This plugin will be needed to fuzz most protobuf code in Chromium. That's
  # because production protobuf code must contain the line:
  # "option optimize_for = LITE_RUNTIME", which instructs the proto compiler not
  # to compile the proto using the full protobuf runtime. This allows Chromium
  # not to depend on the full protobuf library, but prevents
  # libprotobuf-mutator from fuzzing because the lite runtime lacks needed
  # features (such as reflection).  The plugin simply compiles a proto library
  # as normal but ensures that is compiled with the full protobuf runtime.
  executable("override_lite_runtime_plugin") {
    sources = [ "protoc_plugin/protoc_plugin.cc" ]
    deps = [ "//third_party/protobuf:protoc_lib" ]
    public_configs = [ "//third_party/protobuf:protobuf_config" ]
  }
  # To use the plugin in a proto_library you want to fuzz, change the build
  # target to fuzzable_proto_library (defined in
  # //third_party/libprotobuf-mutator/fuzzable_proto_library.gni)
}

# The CQ will try building this target without "use_libfuzzer" if it is defined.
# That will cause the build to fail, so don't define it when "use_libfuzzer" is
# is false.
if (use_libfuzzer) {
  # Test that override_lite_runtime_plugin is working when built. This target
  # contains files that are optimized for LITE_RUNTIME and which import other
  # files that are also optimized for LITE_RUNTIME.
  openscreen_fuzzer_test("override_lite_runtime_plugin_test_fuzzer") {
    sources = [ "protoc_plugin/test_fuzzer.cc" ]
    deps = [
      ":libprotobuf-mutator",
      ":override_lite_runtime_plugin_test_fuzzer_proto",
    ]
  }
}

# Proto library for override_lite_runtime_plugin_test_fuzzer
fuzzable_proto_library("override_lite_runtime_plugin_test_fuzzer_proto") {
  sources = [
    "protoc_plugin/imported.proto",
    "protoc_plugin/imported_publicly.proto",
    "protoc_plugin/test_fuzzer_input.proto",
  ]
}

# Avoid CQ complaints on platforms we don't care about (ie: iOS).
# Also prevent people from using this to include protobuf_full into a production
# build of Chrome.
if (use_libfuzzer) {
  # Component that can provide protobuf_full to non-testonly targets
  static_library("protobuf_full") {
    public_deps = [ "//third_party/protobuf:protobuf_full" ]
  }
}