1 // Copyright 2014 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 #include <algorithm>
6 #include <set>
7
8 #include "base/command_line.h"
9 #include "base/strings/string_split.h"
10 #include "gn/commands.h"
11 #include "gn/metadata_walk.h"
12 #include "gn/setup.h"
13 #include "gn/standard_out.h"
14 #include "gn/switches.h"
15 #include "gn/target.h"
16
17 namespace commands {
18
19 const char kMeta[] = "meta";
20 const char kMeta_HelpShort[] = "meta: List target metadata collection results.";
21 const char kMeta_Help[] =
22 R"(gn meta
23
24 gn meta <out_dir> <target>* --data=<key>[,<key>*]* [--walk=<key>[,<key>*]*]
25 [--rebase=<dest dir>]
26
27 Lists collected metaresults of all given targets for the given data key(s),
28 collecting metadata dependencies as specified by the given walk key(s).
29
30 See `gn help generated_file` for more information on the walk.
31
32 Arguments
33
34 <target(s)>
35 A list of target labels from which to initiate the walk.
36
37 --data
38 A list of keys from which to extract data. In each target walked, its metadata
39 scope is checked for the presence of these keys. If present, the contents of
40 those variable in the scope are appended to the results list.
41
42 --walk (optional)
43 A list of keys from which to control the walk. In each target walked, its
44 metadata scope is checked for the presence of any of these keys. If present,
45 the contents of those variables is checked to ensure that it is a label of
46 a valid dependency of the target and then added to the set of targets to walk.
47 If the empty string ("") is present in any of these keys, all deps and data_deps
48 are added to the walk set.
49
50 --rebase (optional)
51 A destination directory onto which to rebase any paths found. If set, all
52 collected metadata will be rebased onto this path. This option will throw errors
53 if collected metadata is not a list of strings.
54
55 Examples
56
57 gn meta out/Debug "//base/foo" --data=files
58 Lists collected metaresults for the `files` key in the //base/foo:foo
59 target and all of its dependency tree.
60
61 gn meta out/Debug "//base/foo" --data=files --data=other
62 Lists collected metaresults for the `files` and `other` keys in the
63 //base/foo:foo target and all of its dependency tree.
64
65 gn meta out/Debug "//base/foo" --data=files --walk=stop
66 Lists collected metaresults for the `files` key in the //base/foo:foo
67 target and all of the dependencies listed in the `stop` key (and so on).
68
69 gn meta out/Debug "//base/foo" --data=files --rebase="/"
70 Lists collected metaresults for the `files` key in the //base/foo:foo
71 target and all of its dependency tree, rebasing the strings in the `files`
72 key onto the source directory of the target's declaration relative to "/".
73 )";
74
RunMeta(const std::vector<std::string> & args)75 int RunMeta(const std::vector<std::string>& args) {
76 if (args.size() == 0) {
77 Err(Location(), "You're holding it wrong.",
78 "Usage: \"gn meta <out_dir> <target>* --data=<key>[,<key>*] "
79 "[--walk=<key>[,<key>*]*] [--rebase=<dest dir>]\"")
80 .PrintToStdout();
81 return 1;
82 }
83
84 Setup* setup = new Setup;
85 if (!setup->DoSetup(args[0], false) || !setup->Run())
86 return 1;
87
88 const base::CommandLine* cmdline = base::CommandLine::ForCurrentProcess();
89 std::string rebase_dir =
90 cmdline->GetSwitchValueASCII(switches::kMetaRebaseFiles);
91 std::string data_keys_str =
92 cmdline->GetSwitchValueASCII(switches::kMetaDataKeys);
93 std::string walk_keys_str =
94 cmdline->GetSwitchValueASCII(switches::kMetaWalkKeys);
95
96 std::vector<std::string> inputs(args.begin() + 1, args.end());
97
98 UniqueVector<const Target*> targets;
99 for (const auto& input : inputs) {
100 const Target* target = ResolveTargetFromCommandLineString(setup, input);
101 if (!target) {
102 Err(Location(), "Unknown target " + input).PrintToStdout();
103 return 1;
104 }
105 targets.push_back(target);
106 }
107
108 std::vector<std::string> data_keys = base::SplitString(
109 data_keys_str, ",", base::TRIM_WHITESPACE, base::SPLIT_WANT_NONEMPTY);
110 if (data_keys.empty()) {
111 return 1;
112 }
113 std::vector<std::string> walk_keys = base::SplitString(
114 walk_keys_str, ",", base::TRIM_WHITESPACE, base::SPLIT_WANT_NONEMPTY);
115 Err err;
116 std::set<const Target*> targets_walked;
117 SourceDir rebase_source_dir(rebase_dir);
118 // When SourceDir constructor is supplied with an empty string,
119 // a trailing slash will be added. This prevent SourceDir::is_null()
120 // from returning true. Explicitly remove this traling slash here.
121 if (rebase_dir.empty()) {
122 rebase_source_dir = SourceDir();
123 }
124 std::vector<Value> result =
125 WalkMetadata(targets, data_keys, walk_keys, rebase_source_dir,
126 &targets_walked, &err);
127 if (err.has_error()) {
128 err.PrintToStdout();
129 return 1;
130 }
131
132 OutputString("Metadata values\n", DECORATION_DIM);
133 for (const auto& value : result)
134 OutputString("\n" + value.ToString(false) + "\n");
135
136 // TODO(juliehockett): We should have better dep tracing and error support for
137 // this. Also possibly data about where different values came from.
138 OutputString("\nExtracted from:\n", DECORATION_DIM);
139 bool first = true;
140 for (const auto* target : targets_walked) {
141 if (!first) {
142 first = false;
143 OutputString(", ", DECORATION_DIM);
144 }
145 OutputString(target->label().GetUserVisibleName(true) + "\n");
146 }
147 OutputString("\nusing data keys:\n", DECORATION_DIM);
148 first = true;
149 for (const auto& key : data_keys) {
150 if (!first) {
151 first = false;
152 OutputString(", ");
153 }
154 OutputString(key + "\n");
155 }
156 if (!walk_keys.empty()) {
157 OutputString("\nand using walk keys:\n", DECORATION_DIM);
158 first = true;
159 for (const auto& key : walk_keys) {
160 if (!first) {
161 first = false;
162 OutputString(", ");
163 }
164 OutputString(key + "\n");
165 }
166 }
167 return 0;
168 }
169
170 } // namespace commands
171