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