Add initial prototype for the GN meta-buildsystem.

tools/gn/BUILD.gn

Index: tools/gn/BUILD.gn
diff --git a/tools/gn/BUILD.gn b/tools/gn/BUILD.gn
new file mode 100644
index 0000000000000000000000000000000000000000..ccb54113238facce11f9665a88749931b5c66424
--- /dev/null
+++ b/tools/gn/BUILD.gn
@@ -0,0 +1,153 @@
+static_library("gn_lib") {
+  sources = [
+    "build_settings.cc",
+    "build_settings.h",
+    "command_desc.cc",
+    "command_desc.h",
+    "command_gen.cc",
+    "command_gen.h",
+    "command.cc",
+    "config.cc",
+    "config.h",
+    "config_values.h",
+    "config_values_extractors.cc",
+    "config_values_extractors.h",
+    "config_values_generator.cc",
+    "config_values_generator.h",
+    "err.cc",
+    "err.h",
+    "escape.cc",
+    "escape.h",
+    "file_template.cc",
+    "file_template.h",
+    "filesystem_utils.cc",
+    "filesystem_utils.h",
+    "functions.cc",
+    "functions.h",
+    "functions_target.cc",
+    "function_exec_script.cc",
+    "function_process_file_template.cc",
+    "function_read_file.cc",
+    "function_set_default_toolchain.cc",
+    "function_template.cc",
+    "function_toolchain.cc",
+    "function_write_file.cc",
+    "import_manager.cc",
+    "import_manager.h",
+    "input_conversion.cc",
+    "input_conversion.h",
+    "input_file.cc",
+    "input_file.h",
+    "input_file_manager.cc",
+    "input_file_manager.h",
+    "item.cc",
+    "item.h",
+    "item_node.cc",
+    "item_node.h",
+    "item_tree.cc",
+    "item_tree.h",
+    "label.cc",
+    "label.h",
+    "location.h",
+    "ninja_build_writer.cc",
+    "ninja_build_writer.h",
+    "ninja_helper.cc",
+    "ninja_helper.h",
+    "ninja_target_writer.cc",
+    "ninja_target_writer.h",
+    "ninja_toolchain_writer.cc",
+    "ninja_toolchain_writer.h",
+    "ninja_writer.cc",
+    "ninja_writer.h",
+    "operators.cc",
+    "operators.h",
+    "output_file.h",
+    "parse_tree.cc",
+    "parse_tree.h",
+    "parser.cc",
+    "parser.h",
+    "path_output.cc",
+    "path_output.h",
+    "pattern.cc",
+    "pattern.h",
+    "scheduler.cc",
+    "scheduler.h",
+    "scope.cc",
+    "scope.h",
+    "scope_per_file_provider.cc",
+    "scope_per_file_provider.h",
+    "settings.cc",
+    "settings.h",
+    "setup.cc",
+    "setup.h",
+    "source_dir.cc",
+    "source_dir.h",
+    "source_file.cc",
+    "source_file.h",
+    "standard_out.cc",
+    "standard_out.h",
+    "string_utils.cc",
+    "string_utils.h",
+    "target.cc",
+    "target.h",
+    "target_generator.cc",
+    "target_generator.h",
+    "target_manager.cc",
+    "target_manager.h",
+    "token.cc",
+    "token.h",
+    "tokenizer.cc",
+    "tokenizer.h",
+    "toolchain.cc",
+    "toolchain.h",
+    "toolchain_manager.cc",
+    "toolchain_manager.h",
+    "value.cc",
+    "value.h",
+    "value_extractors.cc",
+    "value_extractors.h",
+  ]
+  deps = [
+    "//base",
+    "//base/third_party/dynamic_annotations",
+  ]
+}
+
+executable("gn") {
+  sources = [
+    "gn_main.cc",
+  ]
+  deps = [
+    ":gn_lib",
+  ]
+}
+
+test("gn_unittests") {
+  sources = [
+    "escape_unittest.cc",
+    "file_template_unittest.cc",
+    "filesystem_utils_unittest.cc",
+    "input_conversion_unittest.cc",
+    "label_unittest.cc",
+    "ninja_helper_unittest.cc",
+    "parser_unittest.cc",
+    "path_output_unittest.cc",
+    "pattern_unittest.cc",
+    "source_dir_unittest.cc",
+    "string_utils_unittest.cc",
+    "target_generator_unittest.cc",
+    "target_manager_unittest.cc",
+    "tokenizer_unittest.cc",
+  ]
+  deps = [
+    ":gn_lib",
+    "//base:run_all_unittests",
+    "//base:test_support_base",
+    "//testing:gtest",
+  ]
+}
+
+executable("generate_test_gn_data") {
+  sources = [ "generate_test_gn_data.cc" ]
+  deps = [ "//base" ]
+}