Revert "Add output reference to gen written files."

This reverts commit c497d21798caf871326443ad98bd58f546d7b38e.
AKA https://codereview.chromium.org/1252403005/

TBR=dpranke@chromium.org
BUG=533067
TEST=local re-run of gn gen in a few scenarios

Review URL: https://codereview.chromium.org/1381443002

Cr-Original-Commit-Position: refs/heads/master@{#351319}
Cr-Mirrored-From: https://chromium.googlesource.com/chromium/src
Cr-Mirrored-Commit: a4a5e48c471822d1c51dd00233bf3a167e00d80e

tools/gn/function_write_file.cc

diff --git a/tools/gn/function_write_file.cc b/tools/gn/function_write_file.cc
index 45387a3..d24abc1 100644
--- a/tools/gn/function_write_file.cc
+++ b/tools/gn/function_write_file.cc
@@ -115,6 +115,14 @@
     return Value();
   g_scheduler->AddWrittenFile(source_file);  // Track that we wrote this file.
 
+  // Track how to recreate this file, since we write it a gen time.
+  // Note this is a hack since the correct output is not a dependency proper,
+  // but an addition of this file to the output of the gn rule that writes it.
+  // This dependency will, however, cause the gen step to be re-run and the
+  // build restarted if the file is missing.
+  g_scheduler->AddGenDependency(
+      scope->settings()->build_settings()->GetFullPath(source_file));
+
   // Compute output.
   std::ostringstream contents;
   if (args[1].type() == Value::LIST) {

tools/gn/ninja_build_writer.cc

diff --git a/tools/gn/ninja_build_writer.cc b/tools/gn/ninja_build_writer.cc
index d27ebdc..50638fb 100644
--- a/tools/gn/ninja_build_writer.cc
+++ b/tools/gn/ninja_build_writer.cc
@@ -180,23 +180,10 @@
 void NinjaBuildWriter::WriteNinjaRules() {
   out_ << "rule gn\n";
   out_ << "  command = " << GetSelfInvocationCommand(build_settings_) << "\n";
-  out_ << "  description = Regenerating ninja files\n";
-  out_ << "  restat = 1\n\n";
+  out_ << "  description = Regenerating ninja files\n\n";
 
-  // This rule will regenerate the ninja files when any input file has changed,
-  // or is missing.
-  out_ << "build build.ninja";
-
-  // 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_ << " " << EscapeString(RebasePath(written_file.value(),
-        build_settings_->build_dir(), build_settings_->root_path_utf8()),
-        path_escaping, nullptr);
-
-  out_ << ": gn\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";
 

tools/gn/scheduler.cc

diff --git a/tools/gn/scheduler.cc b/tools/gn/scheduler.cc
index db0929d..622019e 100644
--- a/tools/gn/scheduler.cc
+++ b/tools/gn/scheduler.cc
@@ -113,11 +113,6 @@
   written_files_.push_back(file);
 }
 
-std::vector<SourceFile> Scheduler::GetWrittenFiles() const {
-  base::AutoLock lock(lock_);
-  return written_files_;
-}
-
 void Scheduler::AddUnknownGeneratedInput(const Target* target,
                                          const SourceFile& file) {
   base::AutoLock lock(lock_);

tools/gn/scheduler.h

diff --git a/tools/gn/scheduler.h b/tools/gn/scheduler.h
index 7e29ab5..5d0502f 100644
--- a/tools/gn/scheduler.h
+++ b/tools/gn/scheduler.h
@@ -56,7 +56,6 @@
   // Tracks calls to write_file for resolving with the unknown generated
   // inputs (see AddUnknownGeneratedInput below).
   void AddWrittenFile(const SourceFile& file);
-  std::vector<SourceFile> GetWrittenFiles() const;
 
   // Unknown generated inputs are files that a target declares as an input
   // in the output directory, but which aren't generated by any dependency.