tools/gn/builder.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_BUILDER_H_
   6 #define TOOLS_GN_BUILDER_H_
   7
   8 #include "base/callback.h"
   9 #include "base/containers/hash_tables.h"
  10 #include "base/macros.h"
  11 #include "base/memory/ref_counted.h"
  12 #include "tools/gn/builder_record.h"
  13 #include "tools/gn/label.h"
  14 #include "tools/gn/label_ptr.h"
  15 #include "tools/gn/unique_vector.h"
  16
  17 class Config;
  18 class Err;
  19 class Loader;
  20 class ParseNode;
  21
  22 class Builder : public base::RefCountedThreadSafe<Builder> {
  23  public:
  24   typedef base::Callback<void(const BuilderRecord*)> ResolvedCallback;
  25
  26   explicit Builder(Loader* loader);
  27
  28   // The resolved callback is called whenever a target has been resolved. This
  29   // will be executed only on the main thread.
  30   void set_resolved_callback(const ResolvedCallback& cb) {
  31     resolved_callback_ = cb;
  32   }
  33
  34   Loader* loader() const { return loader_; }
  35
  36   void ItemDefined(scoped_ptr<Item> item);
  37
  38   // Returns NULL if there is not a thing with the corresponding label.
  39   const Item* GetItem(const Label& label) const;
  40   const Toolchain* GetToolchain(const Label& label) const;
  41
  42   std::vector<const BuilderRecord*> GetAllRecords() const;
  43
  44   // Returns targets which should be generated and which are defined.
  45   std::vector<const Target*> GetAllResolvedTargets() const;
  46
  47   // Returns the record for the given label, or NULL if it doesn't exist.
  48   // Mostly used for unit tests.
  49   const BuilderRecord* GetRecord(const Label& label) const;
  50   BuilderRecord* GetRecord(const Label& label);
  51
  52   // If there are any undefined references, returns false and sets the error.
  53   bool CheckForBadItems(Err* err) const;
  54
  55  private:
  56   friend class base::RefCountedThreadSafe<Builder>;
  57
  58   virtual ~Builder();
  59
  60   bool TargetDefined(BuilderRecord* record, Err* err);
  61   bool ToolchainDefined(BuilderRecord* record, Err* err);
  62
  63   // Returns the record associated with the given label. This function checks
  64   // that if we already have references for it, the type matches. If no record
  65   // exists yet, a new one will be created.
  66   //
  67   // If any of the conditions fail, the return value will be null and the error
  68   // will be set. request_from is used as the source of the error.
  69   BuilderRecord* GetOrCreateRecordOfType(const Label& label,
  70                                          const ParseNode* request_from,
  71                                          BuilderRecord::ItemType type,
  72                                          Err* err);
  73
  74   // Returns the record associated with the given label. This function checks
  75   // that it's already been resolved to the correct type.
  76   //
  77   // If any of the conditions fail, the return value will be null and the error
  78   // will be set. request_from is used as the source of the error.
  79   BuilderRecord* GetResolvedRecordOfType(const Label& label,
  80                                          const ParseNode* request_from,
  81                                          BuilderRecord::ItemType type,
  82                                          Err* err);
  83
  84   bool AddDeps(BuilderRecord* record,
  85                const LabelConfigVector& configs,
  86                Err* err);
  87   bool AddDeps(BuilderRecord* record,
  88                const UniqueVector<LabelConfigPair>& configs,
  89                Err* err);
  90   bool AddDeps(BuilderRecord* record,
  91                const LabelTargetVector& targets,
  92                Err* err);
  93   bool AddToolchainDep(BuilderRecord* record,
  94                        const Target* target,
  95                        Err* err);
  96
  97   // Given a target, sets the "should generate" bit and pushes it through the
  98   // dependency tree. Any time the bit it set, we ensure that the given item is
  99   // scheduled to be loaded.
 100   //
 101   // If the force flag is set, we'll ignore the current state of the record's
 102   // should_generate flag, and set it on the dependents every time. This is
 103   // used when defining a target: the "should generate" may have been set
 104   // before the item was defined (if it is required by something that is
 105   // required). In this case, we need to re-push the "should generate" flag
 106   // to the item's dependencies.
 107   void RecursiveSetShouldGenerate(BuilderRecord* record, bool force);
 108
 109   void ScheduleItemLoadIfNecessary(BuilderRecord* record);
 110
 111   // This takes a BuilderRecord with resolved depdencies, and fills in the
 112   // target's Label*Vectors with the resolved pointers.
 113   bool ResolveItem(BuilderRecord* record, Err* err);
 114
 115   // Fills in the pointers in the given vector based on the labels. We assume
 116   // that everything should be resolved by this point, so will return an error
 117   // if anything isn't found or if the type doesn't match.
 118   bool ResolveDeps(LabelTargetVector* deps, Err* err);
 119   bool ResolveConfigs(UniqueVector<LabelConfigPair>* configs, Err* err);
 120   bool ResolveForwardDependentConfigs(Target* target, Err* err);
 121   bool ResolveToolchain(Target* target, Err* err);
 122
 123   // Given a list of unresolved records, tries to find any circular
 124   // dependencies and returns the string describing the problem. If no circular
 125   // deps were found, returns the empty string.
 126   std::string CheckForCircularDependencies(
 127       const std::vector<const BuilderRecord*>& bad_records) const;
 128
 129   // Non owning pointer.
 130   Loader* loader_;
 131
 132   // Owning pointers.
 133   typedef base::hash_map<Label, BuilderRecord*> RecordMap;
 134   RecordMap records_;
 135
 136   ResolvedCallback resolved_callback_;
 137
 138   DISALLOW_COPY_AND_ASSIGN(Builder);
 139 };
 140
 141 #endif  // TOOLS_GN_BUILDER_H_