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depfile_parser.cc
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1 /* Generated by re2c 0.15.3 */
2 // Copyright 2011 Google Inc. All Rights Reserved.
3 //
4 // Licensed under the Apache License, Version 2.0 (the "License");
5 // you may not use this file except in compliance with the License.
6 // You may obtain a copy of the License at
7 //
8 // http://www.apache.org/licenses/LICENSE-2.0
9 //
10 // Unless required by applicable law or agreed to in writing, software
11 // distributed under the License is distributed on an "AS IS" BASIS,
12 // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 // See the License for the specific language governing permissions and
14 // limitations under the License.
15 
16 #include "depfile_parser.h"
17 
18 // A note on backslashes in Makefiles, from reading the docs:
19 // Backslash-newline is the line continuation character.
20 // Backslash-# escapes a # (otherwise meaningful as a comment start).
21 // Backslash-% escapes a % (otherwise meaningful as a special).
22 // Finally, quoting the GNU manual, "Backslashes that are not in danger
23 // of quoting ‘%’ characters go unmolested."
24 // How do you end a line with a backslash? The netbsd Make docs suggest
25 // reading the result of a shell command echoing a backslash!
26 //
27 // Rather than implement all of above, we do a simpler thing here:
28 // Backslashes escape a set of characters (see "escapes" defined below),
29 // otherwise they are passed through verbatim.
30 // If anyone actually has depfiles that rely on the more complicated
31 // behavior we can adjust this.
32 bool DepfileParser::Parse(string* content, string* err) {
33  // in: current parser input point.
34  // end: end of input.
35  // parsing_targets: whether we are parsing targets or dependencies.
36  char* in = &(*content)[0];
37  char* end = in + content->size();
38  bool parsing_targets = true;
39  while (in < end) {
40  // out: current output point (typically same as in, but can fall behind
41  // as we de-escape backslashes).
42  char* out = in;
43  // filename: start of the current parsed filename.
44  char* filename = out;
45  for (;;) {
46  // start: beginning of the current parsed span.
47  const char* start = in;
48 
49  {
50  char yych;
51  static const unsigned char yybm[] = {
52  0, 0, 0, 0, 0, 0, 0, 0,
53  0, 0, 0, 0, 0, 0, 0, 0,
54  0, 0, 0, 0, 0, 0, 0, 0,
55  0, 0, 0, 0, 0, 0, 0, 0,
56  0, 128, 0, 0, 0, 0, 0, 0,
57  128, 128, 0, 128, 128, 128, 128, 128,
58  128, 128, 128, 128, 128, 128, 128, 128,
59  128, 128, 128, 0, 0, 128, 0, 0,
60  128, 128, 128, 128, 128, 128, 128, 128,
61  128, 128, 128, 128, 128, 128, 128, 128,
62  128, 128, 128, 128, 128, 128, 128, 128,
63  128, 128, 128, 0, 0, 0, 0, 128,
64  0, 128, 128, 128, 128, 128, 128, 128,
65  128, 128, 128, 128, 128, 128, 128, 128,
66  128, 128, 128, 128, 128, 128, 128, 128,
67  128, 128, 128, 128, 0, 128, 128, 0,
68  0, 0, 0, 0, 0, 0, 0, 0,
69  0, 0, 0, 0, 0, 0, 0, 0,
70  0, 0, 0, 0, 0, 0, 0, 0,
71  0, 0, 0, 0, 0, 0, 0, 0,
72  0, 0, 0, 0, 0, 0, 0, 0,
73  0, 0, 0, 0, 0, 0, 0, 0,
74  0, 0, 0, 0, 0, 0, 0, 0,
75  0, 0, 0, 0, 0, 0, 0, 0,
76  0, 0, 0, 0, 0, 0, 0, 0,
77  0, 0, 0, 0, 0, 0, 0, 0,
78  0, 0, 0, 0, 0, 0, 0, 0,
79  0, 0, 0, 0, 0, 0, 0, 0,
80  0, 0, 0, 0, 0, 0, 0, 0,
81  0, 0, 0, 0, 0, 0, 0, 0,
82  0, 0, 0, 0, 0, 0, 0, 0,
83  0, 0, 0, 0, 0, 0, 0, 0,
84  };
85  yych = *in;
86  if (yych <= '=') {
87  if (yych <= '$') {
88  if (yych <= ' ') {
89  if (yych <= 0x00) goto yy7;
90  goto yy9;
91  } else {
92  if (yych <= '!') goto yy5;
93  if (yych <= '#') goto yy9;
94  goto yy4;
95  }
96  } else {
97  if (yych <= '*') {
98  if (yych <= '\'') goto yy9;
99  if (yych <= ')') goto yy5;
100  goto yy9;
101  } else {
102  if (yych <= ':') goto yy5;
103  if (yych <= '<') goto yy9;
104  goto yy5;
105  }
106  }
107  } else {
108  if (yych <= '^') {
109  if (yych <= 'Z') {
110  if (yych <= '?') goto yy9;
111  goto yy5;
112  } else {
113  if (yych != '\\') goto yy9;
114  }
115  } else {
116  if (yych <= '{') {
117  if (yych == '`') goto yy9;
118  goto yy5;
119  } else {
120  if (yych <= '|') goto yy9;
121  if (yych <= '~') goto yy5;
122  goto yy9;
123  }
124  }
125  }
126  ++in;
127  if ((yych = *in) <= '"') {
128  if (yych <= '\f') {
129  if (yych <= 0x00) goto yy3;
130  if (yych != '\n') goto yy14;
131  } else {
132  if (yych <= '\r') goto yy3;
133  if (yych == ' ') goto yy16;
134  goto yy14;
135  }
136  } else {
137  if (yych <= 'Z') {
138  if (yych <= '#') goto yy16;
139  if (yych == '*') goto yy16;
140  goto yy14;
141  } else {
142  if (yych <= '\\') goto yy16;
143  if (yych == '|') goto yy16;
144  goto yy14;
145  }
146  }
147 yy3:
148  {
149  // For any other character (e.g. whitespace), swallow it here,
150  // allowing the outer logic to loop around again.
151  break;
152  }
153 yy4:
154  yych = *++in;
155  if (yych == '$') goto yy12;
156  goto yy3;
157 yy5:
158  ++in;
159  yych = *in;
160  goto yy11;
161 yy6:
162  {
163  // Got a span of plain text.
164  int len = (int)(in - start);
165  // Need to shift it over if we're overwriting backslashes.
166  if (out < start)
167  memmove(out, start, len);
168  out += len;
169  continue;
170  }
171 yy7:
172  ++in;
173  {
174  break;
175  }
176 yy9:
177  yych = *++in;
178  goto yy3;
179 yy10:
180  ++in;
181  yych = *in;
182 yy11:
183  if (yybm[0+yych] & 128) {
184  goto yy10;
185  }
186  goto yy6;
187 yy12:
188  ++in;
189  {
190  // De-escape dollar character.
191  *out++ = '$';
192  continue;
193  }
194 yy14:
195  ++in;
196  {
197  // Let backslash before other characters through verbatim.
198  *out++ = '\\';
199  *out++ = yych;
200  continue;
201  }
202 yy16:
203  ++in;
204  {
205  // De-escape backslashed character.
206  *out++ = yych;
207  continue;
208  }
209  }
210 
211  }
212 
213  int len = (int)(out - filename);
214  const bool is_target = parsing_targets;
215  if (len > 0 && filename[len - 1] == ':') {
216  len--; // Strip off trailing colon, if any.
217  parsing_targets = false;
218  }
219 
220  if (len == 0)
221  continue;
222 
223  if (!is_target) {
224  ins_.push_back(StringPiece(filename, len));
225  } else if (!out_.str_) {
226  out_ = StringPiece(filename, len);
227  } else if (out_ != StringPiece(filename, len)) {
228  *err = "depfile has multiple output paths";
229  return false;
230  }
231  }
232  return true;
233 }
const char * str_
Definition: string_piece.h:49
StringPiece represents a slice of a string whose memory is managed externally.
Definition: string_piece.h:27
bool Parse(string *content, string *err)
Parse an input file.
vector< StringPiece > ins_
StringPiece out_