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

tools/gn/config.h

 // 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.
 
 #ifndef TOOLS_GN_CONFIG_H_
 #define TOOLS_GN_CONFIG_H_
 
 #include "base/logging.h"
 #include "base/macros.h"
 #include "tools/gn/config_values.h"
 #include "tools/gn/item.h"
 #include "tools/gn/label_ptr.h"
 #include "tools/gn/unique_vector.h"
 
 // Represents a named config in the dependency graph.
 //
 // A config can list other configs. We track both the data assigned directly
 // on the config, this list of sub-configs, and (when the config is resolved)
 // the resulting values of everything merged together. The flatten step
 // means we can avoid doing a recursive config walk for every target to compute
 // flags.
 class Config : public Item {
  public:
-  Config(const Settings* settings, const Label& label);
+  Config(const Settings* settings,
+         const Label& label,
+         const InputFileSet& input_files);
   ~Config() override;
 
   // Item implementation.
   Config* AsConfig() override;
   const Config* AsConfig() const override;
   bool OnResolved(Err* err) override;
 
   // The values set directly on this config. This will not contain data from
   // sub-configs.
   ConfigValues& own_values() { return own_values_; }
@@ skipping 21 matching lines @@
   // items in configs_. The resolved_values() getter handles this.
   bool resolved_;
   ConfigValues composite_values_;
 
   UniqueVector<LabelConfigPair> configs_;
 
   DISALLOW_COPY_AND_ASSIGN(Config);
 };
 
 #endif  // TOOLS_GN_CONFIG_H_