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.
5 #ifndef TOOLS_GN_ITEM_NODE_H_
6 #define TOOLS_GN_ITEM_NODE_H_
11 #include "base/basictypes.h"
12 #include "base/callback.h"
13 #include "base/memory/scoped_ptr.h"
14 #include "tools/gn/location.h"
20 // Represents a node in the depdency tree. It references an Item which is
23 // The items and nodes are split apart so that the ItemTree can manipulate
24 // the dependencies one one thread while the Item itself is been modified on
28 // The state of this node. As more of the load progresses, we'll move
29 // downward in this list toward the resolved state.
31 // Another item has referenced this one by name, but we have not yet
32 // encountered its definition.
35 // We've seen the definition of this item but have not requested that its
36 // dependencies be loaded. In non-greedy generation mode (see item_tree.h)
37 // some nodes will stay in this state forever as long as they're not needed
38 // for anything that is required.
41 // The item has been defined and we've requested that all of the
42 // dependencies be loaded. Not all of the dependencies have been resolved,
43 // however, and we're still waiting on some build files to be run (or
44 // perhaps there are undefined dependencies).
47 // All of this item's transitive dependencies have been found and
52 // Stores a set of ItemNodes and the associated range that the dependency
54 typedef std::map
<ItemNode
*, LocationRange
> ItemNodeMap
;
56 // Takes ownership of the pointer.
57 // Initial state will be REFERENCED.
61 State
state() const { return state_
; }
63 // This closure will be executed when the item is resolved and it has the
64 // should_generate flag set.
65 void set_resolved_closure(const base::Closure
& closure
) {
66 resolved_closure_
= closure
;
69 const Item
* item() const { return item_
.get(); }
70 Item
* item() { return item_
.get(); }
72 // True if this item should be generated. In greedy mode, this will alwyas
73 // be set. Otherwise, this bit will be "pushed" through the tree to
74 // generate the minimum set of targets required for some special base target.
75 // Initialized to false.
77 // If this item has been defined, setting this flag will schedule the load
78 // of dependent nodes and also set their should_generate bits.
79 bool should_generate() const { return should_generate_
; }
80 bool SetShouldGenerate(const BuildSettings
* build_settings
, Err
* err
);
82 // Where this was created from, which might be when it was generated or
83 // when it was first referenced from another target.
84 const LocationRange
& originally_referenced_from_here() const {
85 return originally_referenced_from_here_
;
87 void set_originally_referenced_from_here(const LocationRange
& r
) {
88 originally_referenced_from_here_
= r
;
91 // Where this was generated from. This will be empty for items that have
92 // been referenced but not generated. Note that this has to be one the
93 // ItemNode because it can be changing from multiple threads and we need
94 // to be sure that access is serialized.
95 const LocationRange
& generated_from_here() const {
96 return generated_from_here_
;
98 void set_generated_from_here(const LocationRange
& r
) {
99 generated_from_here_
= r
;
102 const ItemNodeMap
& direct_dependencies() const {
103 return direct_dependencies_
;
105 const ItemNodeMap
& unresolved_dependencies() const {
106 return unresolved_dependencies_
;
109 bool AddDependency(const BuildSettings
* build_settings
,
110 const LocationRange
& specified_from_here
,
114 // Removes the given dependency from the unresolved list. Does not do
115 // anything else to update waiters.
116 void MarkDirectDependencyResolved(ItemNode
* node
);
118 // Destructively retrieve the set of waiting nodes.
119 void SwapOutWaitingDependencySet(ItemNodeMap
* out_map
);
121 // Marks this item state as defined (see above). If the should generate
122 // flag is set, this will schedule a load of the dependencies and
123 // automatically transition to the PENDING_DEPS state.
124 bool SetDefined(const BuildSettings
* build_settings
, Err
* err
);
126 // Marks this item state as resolved (see above).
130 // Schedules loading the dependencies of this node. The current state must
131 // be DEFINED, and this call will transition the state to PENDING_DEPS.
133 // Requesting deps can fail. On failure returns false and sets the err.
134 bool ScheduleDepsLoad(const BuildSettings
* build_settings
, Err
* err
);
137 scoped_ptr
<Item
> item_
;
138 bool should_generate_
; // See getter above.
140 LocationRange originally_referenced_from_here_
;
141 LocationRange generated_from_here_
;
143 // What to run when this item is resolved.
144 base::Closure resolved_closure_
;
146 // Everything this item directly depends on.
147 ItemNodeMap direct_dependencies_
;
149 // Unresolved things this item directly depends on.
150 ItemNodeMap unresolved_dependencies_
;
152 // These items are waiting on us to be resolved before they can be
153 // resolved. This is the backpointer for unresolved_dependencies_.
154 ItemNodeMap waiting_on_resolution_
;
156 DISALLOW_COPY_AND_ASSIGN(ItemNode
);
159 #endif // TOOLS_GN_ITEM_NODE_H_