Implement tracking of BUILD.gn files used to define target, toolchain or

tools/gn/analyzer.h

 // 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.
 
 #ifndef TOOLS_GN_ANALYZER_H_
 #define TOOLS_GN_ANALYZER_H_
 
 #include <set>
 #include <string>
 #include <vector>
 
 #include "tools/gn/builder.h"
 #include "tools/gn/label.h"
 #include "tools/gn/source_file.h"
 #include "tools/gn/target.h"
 
 // An Analyzer can answer questions about a build graph. It is used
 // to answer queries for the `refs` and `analyze` commands, where we
 // need to look at the graph in ways that can't easily be determined
 // from just a single Target.
 class Analyzer {
  public:
   using LabelSet = std::set<Label>;
   using SourceFileSet = std::set<const SourceFile*>;
   using TargetSet = std::set<const Target*>;
 
-  explicit Analyzer(const Builder& builder);
+  Analyzer(const Builder& builder,
+           const SourceFile& build_config_file,
+           const SourceFile& dotgn_file);
   ~Analyzer();
 
   // Figures out from a Buider and a JSON-formatted string containing lists
   // of files and targets, which targets would be affected by modifications
   // to the files . See the help text for the analyze command (kAnalyze_Help)
   // for the specification of the input and output string formats and the
   // expected behavior of the method.
   std::string Analyze(const std::string& input, Err* err) const;
 
  private:
@@ skipping 38 matching lines @@
   // (see Filter(), above).
   void FilterTarget(const Target*, TargetSet* seen, TargetSet* filtered) const;
 
   bool TargetRefersToFile(const Target* target, const SourceFile* file) const;
 
   void AddTargetsDirectlyReferringToFileTo(const SourceFile* file,
                                            TargetSet* matches) const;
 
   void AddAllRefsTo(const Target* target, TargetSet* matches) const;
 
+  bool WereMainGNFilesModified(const SourceFileSet& source_files) const;
+
   std::vector<const Target*> all_targets_;
   std::map<const Label, const Target*> labels_to_targets_;
   Label default_toolchain_;
   std::set<const Target*> roots_;
 
   // Maps targets to the list of targets that depend on them.
   std::multimap<const Target*, const Target*> dep_map_;
+  SourceFile build_config_file_;
+  SourceFile dotgn_file_;
 };
 
 #endif  // TOOLS_GN_ANALYZER_H_