tools/gn/config.h

   1 // Copyright (c) 2013 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #ifndef TOOLS_GN_CONFIG_H_
   6 #define TOOLS_GN_CONFIG_H_
   7
   8 #include "base/logging.h"
   9 #include "base/macros.h"
  10 #include "tools/gn/config_values.h"
  11 #include "tools/gn/item.h"
  12 #include "tools/gn/label_ptr.h"
  13 #include "tools/gn/unique_vector.h"
  14
  15 // Represents a named config in the dependency graph.
  16 //
  17 // A config can list other configs. We track both the data assigned directly
  18 // on the config, this list of sub-configs, and (when the config is resolved)
  19 // the resulting values of everything merged together. The flatten step
  20 // means we can avoid doing a recursive config walk for every target to compute
  21 // flags.
  22 class Config : public Item {
  23  public:
  24   Config(const Settings* settings, const Label& label);
  25   ~Config() override;
  26
  27   // Item implementation.
  28   Config* AsConfig() override;
  29   const Config* AsConfig() const override;
  30   bool OnResolved(Err* err) override;
  31
  32   // The values set directly on this config. This will not contain data from
  33   // sub-configs.
  34   ConfigValues& own_values() { return own_values_; }
  35   const ConfigValues& own_values() const { return own_values_; }
  36
  37   // The values that represent this config and all sub-configs combined into
  38   // one. This is only valid after the config is resolved (when we know the
  39   // contents of the sub-configs).
  40   const ConfigValues& resolved_values() const {
  41     DCHECK(resolved_);
  42     if (configs_.empty())  // No sub configs, just use the regular values.
  43       return own_values_;
  44     return composite_values_;
  45   }
  46
  47   // List of sub-configs.
  48   const UniqueVector<LabelConfigPair>& configs() const { return configs_; }
  49   UniqueVector<LabelConfigPair>& configs() { return configs_; }
  50
  51  private:
  52   ConfigValues own_values_;
  53
  54   // Contains the own_values combined with sub-configs. Most configs don't have
  55   // sub-configs. So as an optimization, this is not populated if there are no
  56   // items in configs_. The resolved_values() getter handles this.
  57   bool resolved_;
  58   ConfigValues composite_values_;
  59
  60   UniqueVector<LabelConfigPair> configs_;
  61
  62   DISALLOW_COPY_AND_ASSIGN(Config);
  63 };
  64
  65 #endif  // TOOLS_GN_CONFIG_H_