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 "tools/gn/substitution_pattern.h"
6
7 #include "base/strings/string_number_conversions.h"
8 #include "tools/gn/build_settings.h"
9 #include "tools/gn/err.h"
10 #include "tools/gn/filesystem_utils.h"
11 #include "tools/gn/value.h"
12
Subrange()13 SubstitutionPattern::Subrange::Subrange()
14 : type(SUBSTITUTION_LITERAL) {
15 }
16
Subrange(SubstitutionType t,const std::string & l)17 SubstitutionPattern::Subrange::Subrange(SubstitutionType t,
18 const std::string& l)
19 : type(t),
20 literal(l) {
21 }
22
~Subrange()23 SubstitutionPattern::Subrange::~Subrange() {
24 }
25
SubstitutionPattern()26 SubstitutionPattern::SubstitutionPattern() : origin_(NULL) {
27 }
28
~SubstitutionPattern()29 SubstitutionPattern::~SubstitutionPattern() {
30 }
31
Parse(const Value & value,Err * err)32 bool SubstitutionPattern::Parse(const Value& value, Err* err) {
33 if (!value.VerifyTypeIs(Value::STRING, err))
34 return false;
35 return Parse(value.string_value(), value.origin(), err);
36 }
37
Parse(const std::string & str,const ParseNode * origin,Err * err)38 bool SubstitutionPattern::Parse(const std::string& str,
39 const ParseNode* origin,
40 Err* err) {
41 DCHECK(ranges_.empty()); // Should only be called once.
42
43 size_t cur = 0;
44 while (true) {
45 size_t next = str.find("{{", cur);
46
47 // Pick up everything from the previous spot to here as a literal.
48 if (next == std::string::npos) {
49 if (cur != str.size())
50 ranges_.push_back(Subrange(SUBSTITUTION_LITERAL, str.substr(cur)));
51 break;
52 } else if (next > cur) {
53 ranges_.push_back(
54 Subrange(SUBSTITUTION_LITERAL, str.substr(cur, next - cur)));
55 }
56
57 // Find which specific pattern this corresponds to.
58 bool found_match = false;
59 for (size_t i = SUBSTITUTION_FIRST_PATTERN;
60 i < SUBSTITUTION_NUM_TYPES; i++) {
61 const char* cur_pattern = kSubstitutionNames[i];
62 size_t cur_len = strlen(cur_pattern);
63 if (str.compare(next, cur_len, cur_pattern) == 0) {
64 ranges_.push_back(Subrange(static_cast<SubstitutionType>(i)));
65 cur = next + cur_len;
66 found_match = true;
67 break;
68 }
69 }
70
71 // Expect all occurrances of {{ to resolve to a pattern.
72 if (!found_match) {
73 // Could make this error message more friendly if it comes up a lot. But
74 // most people will not be writing substitution patterns and the code
75 // to exactly indicate the error location is tricky.
76 *err = Err(origin, "Unknown substitution pattern",
77 "Found a {{ at offset " +
78 base::SizeTToString(next) +
79 " and did not find a known substitution following it.");
80 ranges_.clear();
81 return false;
82 }
83 }
84
85 origin_ = origin;
86
87 // Fill required types vector.
88 SubstitutionBits bits;
89 FillRequiredTypes(&bits);
90 bits.FillVector(&required_types_);
91 return true;
92 }
93
94 // static
MakeForTest(const char * str)95 SubstitutionPattern SubstitutionPattern::MakeForTest(const char* str) {
96 Err err;
97 SubstitutionPattern pattern;
98 CHECK(pattern.Parse(str, NULL, &err)) << err.message();
99 return pattern;
100 }
101
AsString() const102 std::string SubstitutionPattern::AsString() const {
103 std::string result;
104 for (size_t i = 0; i < ranges_.size(); i++) {
105 if (ranges_[i].type == SUBSTITUTION_LITERAL)
106 result.append(ranges_[i].literal);
107 else
108 result.append(kSubstitutionNames[ranges_[i].type]);
109 }
110 return result;
111 }
112
FillRequiredTypes(SubstitutionBits * bits) const113 void SubstitutionPattern::FillRequiredTypes(SubstitutionBits* bits) const {
114 for (size_t i = 0; i < ranges_.size(); i++) {
115 if (ranges_[i].type != SUBSTITUTION_LITERAL)
116 bits->used[static_cast<size_t>(ranges_[i].type)] = true;
117 }
118 }
119
IsInOutputDir(const BuildSettings * build_settings,Err * err) const120 bool SubstitutionPattern::IsInOutputDir(const BuildSettings* build_settings,
121 Err* err) const {
122 if (ranges_.empty()) {
123 *err = Err(origin_, "This is empty but I was expecting an output file.");
124 return false;
125 }
126
127 if (ranges_[0].type == SUBSTITUTION_LITERAL) {
128 // If the first thing is a literal, it must start with the output dir.
129 if (!EnsureStringIsInOutputDir(
130 build_settings->build_dir(),
131 ranges_[0].literal, origin_, err))
132 return false;
133 } else {
134 // Otherwise, the first subrange must be a pattern that expands to
135 // something in the output directory.
136 if (!SubstitutionIsInOutputDir(ranges_[0].type)) {
137 *err = Err(origin_,
138 "File is not inside output directory.",
139 "The given file should be in the output directory. Normally you\n"
140 "would specify\n\"$target_out_dir/foo\" or "
141 "\"{{source_gen_dir}}/foo\".");
142 return false;
143 }
144 }
145
146 return true;
147 }
148