Redo GN "args" command

tools/gn/ninja_build_writer.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/ninja_build_writer.h"
 
 #include <fstream>
 #include <map>
 
 #include "base/command_line.h"
@@ skipping 33 matching lines @@
   // The command line code quoting varies by platform. We have one string,
   // possibly with spaces, that we want to quote. The Windows command line
   // quotes again, so we don't want quoting. The Posix one doesn't.
   escape_shell.inhibit_quoting = true;
 #endif
 
   const CommandLine& our_cmdline = *CommandLine::ForCurrentProcess();
   const CommandLine::SwitchMap& switches = our_cmdline.GetSwitches();
   for (CommandLine::SwitchMap::const_iterator i = switches.begin();
        i != switches.end(); ++i) {
-    if (i->first != "q" && i->first != "root") {
+    // Only write arguments we haven't already written. Always skip "args"
+    // since those will have been written to the file and will be used
+    // implicitly in the future. Keeping --args would mean changes to the file
+    // would be ignored.
+    if (i->first != "q" && i->first != "root" && i->first != "args") {
       std::string escaped_value =
           EscapeString(FilePathToUTF8(i->second), escape_shell, NULL);
       cmdline.AppendSwitchASCII(i->first, escaped_value);
     }
   }
 
 #if defined(OS_WIN)
   return base::WideToUTF8(cmdline.GetCommandLineString());
 #else
   return cmdline.GetCommandLineString();
@@ skipping 58 matching lines @@
 void NinjaBuildWriter::WriteNinjaRules() {
   out_ << "rule gn\n";
   out_ << "  command = " << GetSelfInvocationCommand(build_settings_) << "\n";
   out_ << "  description = Regenerating ninja files\n\n";
 
   // This rule will regenerate the ninja files when any input file has changed.
   out_ << "build build.ninja: gn\n"
        << "  generator = 1\n"
        << "  depfile = build.ninja.d\n";
 
-  // Provide a way to force regenerating ninja files if the user is suspicious
-  // something is out-of-date. This will be "ninja refresh".
-  out_ << "\nbuild refresh: gn\n";
-
-  // Provide a way to see what flags are associated with this build:
-  // This will be "ninja show".
-  const CommandLine& our_cmdline = *CommandLine::ForCurrentProcess();
-  std::string args = our_cmdline.GetSwitchValueASCII("args");
-  out_ << "rule echo\n";
-  out_ << "  command = echo $text\n";
-  out_ << "  description = ECHO $desc\n";
-  out_ << "build show: echo\n";
-  out_ << "  desc = build arguments:\n";
-  out_ << "  text = "
-       << (args.empty() ? std::string("No build args, using defaults.") : args)
-       << "\n";
-
   // Input build files. These go in the ".d" file. If we write them as
   // dependencies in the .ninja file itself, ninja will expect the files to
   // exist and will error if they don't. When files are listed in a depfile,
   // missing files are ignored.
   dep_out_ << "build.ninja:";
   std::vector<base::FilePath> input_files;
   g_scheduler->input_file_manager()->GetAllPhysicalInputFileNames(&input_files);
   for (size_t i = 0; i < input_files.size(); i++)
     dep_out_ << " " << FilePathToUTF8(input_files[i]);
 
@@ skipping 97 matching lines @@
   EscapeOptions ninja_escape;
   ninja_escape.mode = ESCAPE_NINJA;
 
   // Escape for special chars Ninja will handle.
   std::string escaped = EscapeString(phony_name, ninja_escape, NULL);
 
   out_ << "build " << escaped << ": phony ";
   path_output_.WriteFile(out_, target_file);
   out_ << std::endl;
 }