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#include "tools/gn/action_target_generator.h"
6
7#include "tools/gn/build_settings.h"
8#include "tools/gn/err.h"
9#include "tools/gn/filesystem_utils.h"
10#include "tools/gn/parse_tree.h"
11#include "tools/gn/scope.h"
12#include "tools/gn/value.h"
13#include "tools/gn/value_extractors.h"
14#include "tools/gn/variables.h"
15
16ActionTargetGenerator::ActionTargetGenerator(
17    Target* target,
18    Scope* scope,
19    const FunctionCallNode* function_call,
20    Target::OutputType type,
21    Err* err)
22    : TargetGenerator(target, scope, function_call, err),
23      output_type_(type) {
24}
25
26ActionTargetGenerator::~ActionTargetGenerator() {
27}
28
29void ActionTargetGenerator::DoRun() {
30  target_->set_output_type(output_type_);
31
32  if (!FillSources())
33    return;
34  if (output_type_ == Target::ACTION_FOREACH && target_->sources().empty()) {
35    // Foreach rules must always have some sources to have an effect.
36    *err_ = Err(function_call_, "action_foreach target has no sources.",
37        "If you don't specify any sources, there is nothing to run your\n"
38        "script over.");
39    return;
40  }
41
42  if (!FillInputs())
43    return;
44
45  if (!FillScript())
46    return;
47
48  if (!FillScriptArgs())
49    return;
50
51  if (!FillOutputs(output_type_ == Target::ACTION_FOREACH))
52    return;
53
54  if (!FillDepfile())
55    return;
56
57  if (!CheckOutputs())
58    return;
59
60  // Action outputs don't depend on the current toolchain so we can skip adding
61  // that dependency.
62}
63
64bool ActionTargetGenerator::FillScript() {
65  // If this gets called, the target type requires a script, so error out
66  // if it doesn't have one.
67  const Value* value = scope_->GetValue(variables::kScript, true);
68  if (!value) {
69    *err_ = Err(function_call_, "This target type requires a \"script\".");
70    return false;
71  }
72  if (!value->VerifyTypeIs(Value::STRING, err_))
73    return false;
74
75  SourceFile script_file =
76      scope_->GetSourceDir().ResolveRelativeFile(value->string_value());
77  if (script_file.value().empty()) {
78    *err_ = Err(*value, "script name is empty");
79    return false;
80  }
81  target_->action_values().set_script(script_file);
82  return true;
83}
84
85bool ActionTargetGenerator::FillScriptArgs() {
86  const Value* value = scope_->GetValue(variables::kArgs, true);
87  if (!value)
88    return true;
89  return target_->action_values().args().Parse(*value, err_);
90}
91
92bool ActionTargetGenerator::FillDepfile() {
93  const Value* value = scope_->GetValue(variables::kDepfile, true);
94  if (!value)
95    return true;
96
97  SubstitutionPattern depfile;
98  if (!depfile.Parse(*value, err_))
99    return false;
100  if (!EnsureSubstitutionIsInOutputDir(depfile, *value))
101    return false;
102
103  target_->action_values().set_depfile(depfile);
104  return true;
105}
106
107bool ActionTargetGenerator::CheckOutputs() {
108  const SubstitutionList& outputs = target_->action_values().outputs();
109  if (outputs.list().empty()) {
110    *err_ = Err(function_call_, "Action has no outputs.",
111        "If you have no outputs, the build system can not tell when your\n"
112        "script needs to be run.");
113    return false;
114  }
115
116  if (output_type_ == Target::ACTION) {
117    if (!outputs.required_types().empty()) {
118      *err_ = Err(function_call_, "Action has patterns in the output.",
119          "An action target should have the outputs completely specified. If\n"
120          "you want to provide a mapping from source to output, use an\n"
121          "\"action_foreach\" target.");
122      return false;
123    }
124  } else if (output_type_ == Target::ACTION_FOREACH) {
125    // A foreach target should always have a pattern in the outputs.
126    if (outputs.required_types().empty()) {
127      *err_ = Err(function_call_,
128          "action_foreach should have a pattern in the output.",
129          "An action_foreach target should have a source expansion pattern in\n"
130          "it to map source file to unique output file name. Otherwise, the\n"
131          "build system can't determine when your script needs to be run.");
132      return false;
133    }
134  }
135  return true;
136}
137