[GN] Add JSON project writer

tools/gn/command_gen.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 "base/atomicops.h"
 #include "base/bind.h"
 #include "base/command_line.h"
 #include "base/strings/string_number_conversions.h"
 #include "base/strings/stringprintf.h"
 #include "base/timer/elapsed_timer.h"
 #include "tools/gn/build_settings.h"
 #include "tools/gn/commands.h"
 #include "tools/gn/eclipse_writer.h"
+#include "tools/gn/json_project_writer.h"
 #include "tools/gn/ninja_target_writer.h"
 #include "tools/gn/ninja_writer.h"
 #include "tools/gn/qt_creator_writer.h"
 #include "tools/gn/runtime_deps.h"
 #include "tools/gn/scheduler.h"
 #include "tools/gn/setup.h"
 #include "tools/gn/standard_out.h"
 #include "tools/gn/switches.h"
 #include "tools/gn/target.h"
 #include "tools/gn/visual_studio_writer.h"
 #include "tools/gn/xcode_writer.h"
 
 namespace commands {
 
 namespace {
 
 const char kSwitchCheck[] = "check";
 const char kSwitchFilters[] = "filters";
 const char kSwitchIde[] = "ide";
 const char kSwitchIdeValueEclipse[] = "eclipse";
 const char kSwitchIdeValueQtCreator[] = "qtcreator";
 const char kSwitchIdeValueVs[] = "vs";
 const char kSwitchIdeValueVs2013[] = "vs2013";
 const char kSwitchIdeValueVs2015[] = "vs2015";
 const char kSwitchIdeValueXcode[] = "xcode";
+const char kSwitchIdeValueJSON[] = "json";
 const char kSwitchNinjaExtraArgs[] = "ninja-extra-args";
 const char kSwitchRootTarget[] = "root-target";
 const char kSwitchSln[] = "sln";
 const char kSwitchWorkspace[] = "workspace";
+const char kSwitchFileName[] = "file-name";
+const char kSwitchExecScript[] = "exec-script";

[brettw, 2016/07/06 22:19:26]

Can we call this something like "json_ide_script" or something to make clear
this is applying to the json output? There's already something called
exec_script so this more general name is a bit confusing to me.

[matt.k, 2016/07/08 00:39:07]

Done.

+const char kSwitchExecScriptExtraArgs[] = "exec-script-extra-args";
 
 // Called on worker thread to write the ninja file.
 void BackgroundDoWrite(const Target* target) {
   NinjaTargetWriter::RunAndWriteFile(target);
   g_scheduler->DecrementWorkCount();
 }
 
 // Called on the main thread.
 void ItemResolvedCallback(base::subtle::Atomic32* write_counter,
                           scoped_refptr<Builder> builder,
@@ skipping 53 matching lines @@
 
   const std::string target_str = targets.size() > 1 ? "targets" : "target";
   err += "The file:\n";
   err += "  " + file.value() + "\n";
   err += "is listed as an input or source for the " + target_str + ":\n";
   for (const Target* target : targets)
     err += "  " + target->label().GetUserVisibleName(show_toolchains) + "\n";
 
   if (generator) {
     err += "but this file was not generated by any dependencies of the " +
-        target_str + ". The target\nthat generates the file is:\n  ";
+           target_str + ". The target\nthat generates the file is:\n  ";
     err += generator->label().GetUserVisibleName(show_toolchains);
   } else {
     err += "but no targets in the build generate that file.";
   }
 
   Err(Location(), "Input to " + target_str + " not generated by a dependency.",
       err).PrintToStdout();
 }
 
 bool CheckForInvalidGeneratedInputs(Setup* setup) {
@@ skipping 86 matching lines @@
     if (command_line->HasSwitch(kSwitchRootTarget))
       root_target = command_line->GetSwitchValueASCII(kSwitchRootTarget);
     bool res = QtCreatorWriter::RunAndWriteFile(build_settings, builder, err,
                                                 root_target);
     if (res && !command_line->HasSwitch(switches::kQuiet)) {
       OutputString("Generating QtCreator projects took " +
                    base::Int64ToString(timer.Elapsed().InMilliseconds()) +
                    "ms\n");
     }
     return res;
+  } else if (ide == kSwitchIdeValueJSON) {
+    std::string file_name = command_line->GetSwitchValueASCII(kSwitchFileName);
+    if (file_name.empty())
+      file_name = "project.json";
+    std::string exec_script =
+        command_line->GetSwitchValueASCII(kSwitchExecScript);
+    std::string exec_script_extra_args =
+        command_line->GetSwitchValueASCII(kSwitchExecScriptExtraArgs);
+    std::string filters = command_line->GetSwitchValueASCII(kSwitchFilters);
+
+    bool quiet = command_line->HasSwitch(switches::kQuiet);

[brettw, 2016/07/06 22:19:26]

This is duplicated from above (which already duplicates it a few times. It would
be nice if your variable was just moved to the top of the function and then
everybody just referenced it instead of calling HasSwitch.

[matt.k, 2016/07/08 00:39:07]

Done.

+    bool res = JSONProjectWriter::RunAndWriteFiles(
+        build_settings, builder, file_name, exec_script, exec_script_extra_args,
+        filters, quiet, err);
+    if (res && !quiet) {
+      OutputString("Generating JSON projects took " +
+                   base::Int64ToString(timer.Elapsed().InMilliseconds()) +
+                   "ms\n");
+    }
+    return res;
   }
 
   *err = Err(Location(), "Unknown IDE: " + ide);
   return false;
 }
 
 }  // namespace
 
 const char kGen[] = "gen";
-const char kGen_HelpShort[] =
-    "gen: Generate ninja files.";
+const char kGen_HelpShort[] = "gen: Generate ninja files.";
 const char kGen_Help[] =
     "gn gen: Generate ninja files.\n"
     "\n"
     "  gn gen [<ide options>] <out_dir>\n"
     "\n"
     "  Generates ninja files from the current tree and puts them in the given\n"
     "  output directory.\n"
     "\n"
     "  The output directory can be a source-repo-absolute path name such as:\n"
     "      //out/foo\n"
     "  Or it can be a directory relative to the current directory such as:\n"
     "      out/foo\n"
     "\n"
     "  See \"gn help switches\" for the common command-line switches.\n"
     "\n"
     "IDE options\n"
     "\n"
     "  GN optionally generates files for IDE. Possibilities for <ide options>\n"
     "\n"
     "  --ide=<ide_name>\n"
     "      Generate files for an IDE. Currently supported values:\n"
     "      \"eclipse\" - Eclipse CDT settings file.\n"
     "      \"vs\" - Visual Studio project/solution files.\n"
     "             (default Visual Studio version: 2015)\n"
     "      \"vs2013\" - Visual Studio 2013 project/solution files.\n"
     "      \"vs2015\" - Visual Studio 2015 project/solution files.\n"
     "      \"xcode\" - Xcode workspace/solution files.\n"
     "      \"qtcreator\" - QtCreator project files.\n"
+    "      \"json\" - JSON file containing target information\n"
     "\n"
     "  --filters=<path_prefixes>\n"
     "      Semicolon-separated list of label patterns used to limit the set\n"
     "      of generated projects (see \"gn help label_pattern\"). Only\n"
     "      matching targets and their dependencies will be included in the\n"
-    "      solution. Only used for Visual Studio and Xcode.\n"
+    "      solution. Only used for Visual Studio, Xcode and JSON.\n"
     "\n"
     "Visual Studio Flags\n"
     "\n"
     "  --sln=<file_name>\n"
     "      Override default sln file name (\"all\"). Solution file is written\n"
     "      to the root build directory.\n"
     "\n"
     "Xcode Flags\n"
     "\n"
     "  --workspace=<file_name>\n"
@@ skipping 20 matching lines @@
     "\n"
     "Eclipse IDE Support\n"
     "\n"
     "  GN DOES NOT generate Eclipse CDT projects. Instead, it generates a\n"
     "  settings file which can be imported into an Eclipse CDT project. The\n"
     "  XML file contains a list of include paths and defines. Because GN does\n"
     "  not generate a full .cproject definition, it is not possible to\n"
     "  properly define includes/defines for each file individually.\n"
     "  Instead, one set of includes/defines is generated for the entire\n"
     "  project. This works fairly well but may still result in a few indexer\n"
-    "  issues here and there.\n";
+    "  issues here and there.\n"
+    "\n"
+    "Generic JSON Output\n"
+    "\n"
+    "  Dumps target information to JSON file and optionally invokes a python\n"
+    "  script.\n"
+    "\n"
+    "  --file_name=<json_file_name>\n"
+    "      Overrides default file name of generated JSON file.\n"

[brettw, 2016/07/06 22:19:26]

Can you list what the default file name is here?

[matt.k, 2016/07/08 00:39:07]

Done.

+    "\n"
+    "  --exec-script=<path_to_python_script>\n"
+    "      Executes python script after the JSON file is generated.\n"
+    "      Path can be project absolute (//), system absolute (/) or\n"
+    "      relative, in which case the output directory will be base.\n"
+    "      Path to generated JSON file will be first argument when invoking\n"
+    "      script.\n"
+    "\n"
+    "  --exec-script-extra-args=<argument>\n"
+    "      Optional second argument that will passed to executed-script.\n";
 
 int RunGen(const std::vector<std::string>& args) {
   base::ElapsedTimer timer;
 
   if (args.size() != 1) {
     Err(Location(), "Need exactly one build directory to generate.",
         "I expected something more like \"gn gen out/foo\"\n"
         "You can also see \"gn help gen\".").PrintToStdout();
     return 1;
   }
@@ skipping 55 matching lines @@
             setup->scheduler().input_file_manager()->GetInputFileCount()) +
         " files in " +
         base::Int64ToString(elapsed_time.InMilliseconds()) + "ms\n";
     OutputString(stats);
   }
 
   return 0;
 }
 
 }  // namespace commands