Add output reference to gen written files.

tools/gn/ninja_build_writer.cc

Index: tools/gn/ninja_build_writer.cc
diff --git a/tools/gn/ninja_build_writer.cc b/tools/gn/ninja_build_writer.cc
index 591947d38cae9ca29918c11fc7697625fd56a229..12a37e13d8b5eaa735339b37a8ebed52b47fb670 100644
--- a/tools/gn/ninja_build_writer.cc
+++ b/tools/gn/ninja_build_writer.cc
@@ -76,7 +76,6 @@ std::string GetSelfInvocationCommand(const BuildSettings* build_settings) {
   return cmdline.GetCommandLineString();
 #endif
 }
-
 }  // namespace
 
 NinjaBuildWriter::NinjaBuildWriter(
@@ -143,10 +142,23 @@ bool NinjaBuildWriter::RunAndWriteFile(
 void NinjaBuildWriter::WriteNinjaRules() {
   out_ << "rule gn\n";
   out_ << "  command = " << GetSelfInvocationCommand(build_settings_) << "\n";
-  out_ << "  description = Regenerating ninja files\n\n";
+  out_ << "  description = Regenerating ninja files\n";
+  out_ << "  restat = 1\n\n";

[Peter Mayo, 2015/09/23 18:53:34]

This is important for this change.

+
+  // This rule will regenerate the ninja files when any input file has changed,
+  // or is missing.
+  out_ << "build build.ninja";
 
-  // This rule will regenerate the ninja files when any input file has changed.
-  out_ << "build build.ninja: gn\n"
+  // Other files read by the build.
+  EscapeOptions path_escaping;
+  path_escaping.mode = ESCAPE_NINJA_COMMAND;
+  std::vector<SourceFile> written_files = g_scheduler->GetWrittenFiles();
+  for (const auto& written_file : written_files)
+    out_ << " " <<

[Peter Mayo, 2015/07/30 23:25:32]

Is this the right wrapping?  dropping the << onto the next line causes follow-on
un-nesting.

[Dirk Pranke, 2015/07/30 23:37:08]

no clue :).

[brettw, 2015/07/31 00:57:01]

Seems "not wrong"

+        EscapeString(FilePathToUTF8(build_settings_->GetFullPath(written_file)),
+                     path_escaping, nullptr);
+
+  out_ << ": gn\n"
        << "  generator = 1\n"
        << "  depfile = build.ninja.d\n";