Get gn analyze to respect changes to vs_toolchain.py

tools/gn/analyzer.cc

 // Copyright 2016 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/analyzer.h"
 
 #include <algorithm>
 #include <iterator>
 #include <set>
 #include <vector>
@@ skipping 41 matching lines @@
 LabelSet LabelsFor(const TargetSet& targets) {
   LabelSet labels;
   for (auto* target : targets)
     labels.insert(target->label());
   return labels;
 }
 
 bool AnyBuildFilesWereModified(const SourceFileSet& source_files) {
   for (auto* file : source_files) {
     if (base::EndsWith(file->value(), ".gn", base::CompareCase::SENSITIVE) ||
-        base::EndsWith(file->value(), ".gni", base::CompareCase::SENSITIVE))
+        base::EndsWith(file->value(), ".gni", base::CompareCase::SENSITIVE) ||
+        file->GetName() == "vs_toolchain.py")

[brettw, 2017/03/29 23:05:07]

I notice there are three such files:
 //v8/gypfiles/vs_toolchain.py
 //build/vs_toolchain.py
 //third_party/boringssl/src/util/bot/vs_toolchain.py
and only one of them counts. If boringssl rolls and we get an updated version of
it's toolchain file, it sort of sucks to rebuild all. Is there a more precise
way to specify this? Not a huge deal if it's hard.

       return true;
   }
   return false;
 }
 
 TargetSet Intersect(const TargetSet& l, const TargetSet& r) {
   TargetSet result;
   std::set_intersection(l.begin(), l.end(), r.begin(), r.end(),
                         std::inserter(result, result.begin()));
   return result;
@@ skipping 182 matching lines @@
   for (const auto& label : InvalidLabels(inputs.test_labels))
     invalid_labels.insert(label);
   if (!invalid_labels.empty()) {
     outputs.error = "Invalid targets";
     outputs.invalid_labels = invalid_labels;
     return OutputsToJSON(outputs, default_toolchain_, err);
   }
 
   // TODO(crbug.com/555273): We can do smarter things when we detect changes
   // to build files. For example, if all of the ninja files are unchanged,
-  // we know that we can ignore changes to these files. Also, for most .gn
+  // we know that we can ignore changes to .gn* files. Also, for most .gn
   // files, we can treat a change as simply affecting every target, config,
   // or toolchain defined in that file.
   if (AnyBuildFilesWereModified(inputs.source_files)) {
     outputs.status = "Found dependency (all)";
     if (inputs.compile_included_all) {
       outputs.compile_includes_all = true;
     } else {
       outputs.compile_labels.insert(inputs.compile_labels.begin(),
                                     inputs.compile_labels.end());
       outputs.compile_labels.insert(inputs.test_labels.begin(),
@@ skipping 127 matching lines @@
 void Analyzer::AddAllRefsTo(const Target* target, TargetSet* results) const {
   if (results->find(target) != results->end())
     return;  // Already found this target.
   results->insert(target);
 
   auto dep_begin = dep_map_.lower_bound(target);
   auto dep_end = dep_map_.upper_bound(target);
   for (auto cur_dep = dep_begin; cur_dep != dep_end; cur_dep++)
     AddAllRefsTo(cur_dep->second, results);
 }