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_VALUES_EXTRACTORS_H_
6 #define TOOLS_GN_CONFIG_VALUES_EXTRACTORS_H_
7
8 #include <ostream>
9 #include <string>
10 #include <vector>
11
12 #include "tools/gn/config.h"
13 #include "tools/gn/config_values.h"
14 #include "tools/gn/target.h"
15
16 struct EscapeOptions;
17
18 // Provides a way to iterate through all ConfigValues applying to a given
19 // target. This is more complicated than normal because the target has a list
20 // of configs applying to it, and also config values on the target itself.
21 //
22 // This iterator allows one to iterate through all of these in a defined order
23 // in one convenient loop. The order is defined to be the ConfigValues on the
24 // target itself first, then the applying configs, in order.
25 //
26 // Example:
27 // for (ConfigValueIterator iter(target); !iter.done(); iter.Next())
28 // DoSomething(iter->cur());
29 class ConfigValuesIterator {
30 public:
ConfigValuesIterator(const Target * target)31 explicit ConfigValuesIterator(const Target* target)
32 : target_(target),
33 cur_index_(-1) {
34 }
35
done()36 bool done() const {
37 return cur_index_ >= static_cast<int>(target_->configs().size());
38 }
39
cur()40 const ConfigValues& cur() const {
41 if (cur_index_ == -1)
42 return target_->config_values();
43 return target_->configs()[cur_index_].ptr->config_values();
44 }
45
46 // Returns the origin of who added this config, if any. This will alwsya be
47 // null for the config values of a target itself.
origin()48 const ParseNode* origin() const {
49 if (cur_index_ == -1)
50 return NULL;
51 return target_->configs()[cur_index_].origin;
52 }
53
Next()54 void Next() {
55 cur_index_++;
56 }
57
58 // Returns the config holding the current config values, or NULL for those
59 // config values associated with the target itself.
GetCurrentConfig()60 const Config* GetCurrentConfig() const {
61 if (cur_index_ == -1)
62 return NULL;
63 return target_->configs()[cur_index_].ptr;
64 }
65
66 private:
67 const Target* target_;
68
69 // Represents an index into the target_'s configs() or, when -1, the config
70 // values on the target itself.
71 int cur_index_;
72 };
73
74 template<typename T, class Writer>
ConfigValuesToStream(const ConfigValues & values,const std::vector<T> & (ConfigValues::* getter)()const,const Writer & writer,std::ostream & out)75 inline void ConfigValuesToStream(
76 const ConfigValues& values,
77 const std::vector<T>& (ConfigValues::* getter)() const,
78 const Writer& writer,
79 std::ostream& out) {
80 const std::vector<T>& v = (values.*getter)();
81 for (size_t i = 0; i < v.size(); i++)
82 writer(v[i], out);
83 };
84
85 // Writes a given config value that applies to a given target. This collects
86 // all values from the target itself and all configs that apply, and writes
87 // then in order.
88 template<typename T, class Writer>
RecursiveTargetConfigToStream(const Target * target,const std::vector<T> & (ConfigValues::* getter)()const,const Writer & writer,std::ostream & out)89 inline void RecursiveTargetConfigToStream(
90 const Target* target,
91 const std::vector<T>& (ConfigValues::* getter)() const,
92 const Writer& writer,
93 std::ostream& out) {
94 for (ConfigValuesIterator iter(target); !iter.done(); iter.Next())
95 ConfigValuesToStream(iter.cur(), getter, writer, out);
96 }
97
98 // Writes the values out as strings with no transformation.
99 void RecursiveTargetConfigStringsToStream(
100 const Target* target,
101 const std::vector<std::string>& (ConfigValues::* getter)() const,
102 const EscapeOptions& escape_options,
103 std::ostream& out);
104
105 #endif // TOOLS_GN_CONFIG_VALUES_EXTRACTORS_H_
106