[GN] Add JSON project writer

tools/gn/target.cc

 // Copyright (c) 2013 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.
 
 #include "tools/gn/target.h"
 
 #include <stddef.h>
 
 #include <algorithm>
 
 #include "base/bind.h"
 #include "base/strings/string_util.h"
 #include "base/strings/stringprintf.h"
 #include "tools/gn/config_values_extractors.h"
 #include "tools/gn/deps_iterator.h"
 #include "tools/gn/filesystem_utils.h"
+#include "tools/gn/functions.h"
 #include "tools/gn/scheduler.h"
 #include "tools/gn/source_file_type.h"
 #include "tools/gn/substitution_writer.h"
 #include "tools/gn/tool.h"
 #include "tools/gn/toolchain.h"
 #include "tools/gn/trace.h"
 
 namespace {
 
 typedef std::set<const Config*> ConfigSet;
@@ skipping 181 matching lines @@
       toolchain_(nullptr) {
 }
 
 Target::~Target() {
 }
 
 // static
 const char* Target::GetStringForOutputType(OutputType type) {
   switch (type) {
     case UNKNOWN:
-      return "Unknown";
+      return "unknown";
     case GROUP:
-      return "Group";
+      return functions::kGroup;
     case EXECUTABLE:
-      return "Executable";
+      return functions::kExecutable;
     case LOADABLE_MODULE:
-      return "Loadable module";
+      return functions::kLoadableModule;
     case SHARED_LIBRARY:
-      return "Shared library";
+      return functions::kSharedLibrary;
     case STATIC_LIBRARY:
-      return "Static library";
+      return functions::kStaticLibrary;
     case SOURCE_SET:
-      return "Source set";
+      return functions::kSourceSet;
     case COPY_FILES:
-      return "Copy";
+      return functions::kCopy;
     case ACTION:
-      return "Action";
+      return functions::kAction;
     case ACTION_FOREACH:
-      return "ActionForEach";
+      return functions::kActionForEach;
     case BUNDLE_DATA:
-      return "Bundle data";
+      return functions::kBundleData;
     case CREATE_BUNDLE:
-      return "Create bundle";
+      return functions::kCreateBundle;
     default:
       return "";
   }
 }
 
 Target* Target::AsTarget() {
   return this;
 }
 
 const Target* Target::AsTarget() const {
@@ skipping 512 matching lines @@
     check_data_deps = g_scheduler->IsFileGeneratedByWriteRuntimeDeps(out_file);
     // Check object files (much slower and very rare) only if the "normal"
     // output check failed.
     consider_object_files = !check_data_deps;
     if (!EnsureFileIsGeneratedByDependency(this, out_file, true,
                                            consider_object_files,
                                            check_data_deps, &seen_targets))
       g_scheduler->AddUnknownGeneratedInput(this, source);
   }
 }