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f640bcb3 RK |
1 | /* |
2 | * This file is part of DisOrder | |
3 | * Copyright (C) 2008 Richard Kettlewell | |
4 | * | |
5 | * This program is free software; you can redistribute it and/or modify | |
6 | * it under the terms of the GNU General Public License as published by | |
7 | * the Free Software Foundation; either version 2 of the License, or | |
8 | * (at your option) any later version. | |
9 | * | |
10 | * This program is distributed in the hope that it will be useful, but | |
11 | * WITHOUT ANY WARRANTY; without even the implied warranty of | |
12 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | |
13 | * General Public License for more details. | |
14 | * | |
15 | * You should have received a copy of the GNU General Public License | |
16 | * along with this program; if not, write to the Free Software | |
17 | * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 | |
18 | * USA | |
19 | */ | |
20 | ||
21 | /** @file lib/macros-builtin.c | |
22 | * @brief Built-in expansions | |
23 | * | |
b36be3a1 RK |
24 | * This is a grab-bag of non-domain-specific expansions. Documentation will be |
25 | * generated from the comments at the head of each function. | |
f640bcb3 RK |
26 | */ |
27 | ||
28 | #include <config.h> | |
29 | #include "types.h" | |
30 | ||
31 | #include <stdio.h> | |
32 | #include <string.h> | |
33 | #include <errno.h> | |
34 | #include <assert.h> | |
35 | #include <unistd.h> | |
b36be3a1 RK |
36 | #include <fcntl.h> |
37 | #include <sys/stat.h> | |
c240ff9a | 38 | #include <sys/wait.h> |
f640bcb3 | 39 | |
9faa7a88 | 40 | #include "hash.h" |
b36be3a1 | 41 | #include "mem.h" |
f640bcb3 RK |
42 | #include "macros.h" |
43 | #include "sink.h" | |
44 | #include "syscalls.h" | |
45 | #include "log.h" | |
46 | #include "wstat.h" | |
47 | #include "kvp.h" | |
b36be3a1 RK |
48 | #include "split.h" |
49 | #include "printf.h" | |
50 | #include "vector.h" | |
51 | ||
52 | static struct vector include_path; | |
f640bcb3 RK |
53 | |
54 | /** @brief Return 1 if @p s is 'true' else 0 */ | |
55 | int mx_str2bool(const char *s) { | |
56 | return !strcmp(s, "true"); | |
57 | } | |
58 | ||
59 | /** @brief Return "true" if @p n is nonzero else "false" */ | |
60 | const char *mx_bool2str(int n) { | |
61 | return n ? "true" : "false"; | |
62 | } | |
63 | ||
b36be3a1 | 64 | /** @brief Write a boolean result */ |
71634563 | 65 | int mx_bool_result(struct sink *output, int result) { |
b36be3a1 RK |
66 | if(sink_writes(output, mx_bool2str(result)) < 0) |
67 | return -1; | |
68 | else | |
69 | return 0; | |
70 | } | |
71 | ||
9faa7a88 RK |
72 | /** @brief Search the include path */ |
73 | char *mx_find(const char *name) { | |
74 | char *path; | |
75 | int n; | |
76 | ||
77 | if(name[0] == '/') { | |
78 | if(access(name, O_RDONLY) < 0) { | |
79 | error(errno, "cannot read %s", name); | |
80 | return 0; | |
81 | } | |
82 | path = xstrdup(name); | |
83 | } else { | |
84 | /* Search the include path */ | |
85 | for(n = 0; n < include_path.nvec; ++n) { | |
86 | byte_xasprintf(&path, "%s/%s", include_path.vec[n], name); | |
87 | if(access(path, O_RDONLY) == 0) | |
88 | break; | |
89 | } | |
90 | if(n >= include_path.nvec) { | |
91 | error(0, "cannot find '%s' in search path", name); | |
92 | return 0; | |
93 | } | |
94 | } | |
95 | return path; | |
96 | } | |
97 | ||
98 | /* @include{TEMPLATE}@ | |
b36be3a1 RK |
99 | * |
100 | * Includes TEMPLATE. | |
101 | * | |
102 | * TEMPLATE can be an absolute filename starting with a '/'; only the file with | |
103 | * exactly this name will be included. | |
104 | * | |
105 | * Alternatively it can be a relative filename, not starting with a '/'. In | |
106 | * this case the file will be searched for in the include path. When searching | |
107 | * paths, unreadable files are treated as if they do not exist (rather than | |
108 | * matching then producing an error). | |
f640bcb3 | 109 | * |
b36be3a1 RK |
110 | * If the name chosen ends ".tmpl" then the file will be expanded as a |
111 | * template. Anything else is included byte-for-byte without further | |
112 | * modification. | |
113 | * | |
114 | * Only regular files are allowed (no devices, sockets or name pipes). | |
f640bcb3 RK |
115 | */ |
116 | static int exp_include(int attribute((unused)) nargs, | |
b36be3a1 RK |
117 | char **args, |
118 | struct sink *output, | |
119 | void *u) { | |
9faa7a88 | 120 | const char *path; |
b36be3a1 RK |
121 | int fd, n; |
122 | char buffer[4096]; | |
123 | struct stat sb; | |
b36be3a1 | 124 | |
9faa7a88 | 125 | if(!(path = mx_find(args[0]))) { |
f5fdc06f | 126 | if(sink_printf(output, "[[cannot find '%s']]", args[0]) < 0) |
dd0f422a | 127 | return 0; |
9faa7a88 | 128 | return 0; |
b36be3a1 RK |
129 | } |
130 | /* If it's a template expand it */ | |
131 | if(strlen(path) >= 5 && !strncmp(path + strlen(path) - 5, ".tmpl", 5)) | |
132 | return mx_expand_file(path, output, u); | |
133 | /* Read the raw file. As with mx_expand_file() we insist that the file is a | |
134 | * regular file. */ | |
135 | if((fd = open(path, O_RDONLY)) < 0) | |
136 | fatal(errno, "error opening %s", path); | |
137 | if(fstat(fd, &sb) < 0) | |
138 | fatal(errno, "error statting %s", path); | |
139 | if(!S_ISREG(sb.st_mode)) | |
140 | fatal(0, "%s: not a regular file", path); | |
141 | while((n = read(fd, buffer, sizeof buffer)) > 0) { | |
142 | if(sink_write(output, buffer, n) < 0) { | |
143 | xclose(fd); | |
144 | return -1; | |
145 | } | |
146 | } | |
147 | if(n < 0) | |
148 | fatal(errno, "error reading %s", path); | |
149 | xclose(fd); | |
150 | return 0; | |
f640bcb3 RK |
151 | } |
152 | ||
9faa7a88 | 153 | /* @include{COMMAND}@ |
f640bcb3 RK |
154 | * |
155 | * Executes COMMAND via the shell (using "sh -c") and copies its | |
156 | * standard output to the template output. The shell command output | |
157 | * is not expanded or modified in any other way. | |
158 | * | |
159 | * The shell command's standard error is copied to the error log. | |
160 | * | |
161 | * If the shell exits nonzero then this is reported to the error log | |
162 | * but otherwise no special action is taken. | |
163 | */ | |
164 | static int exp_shell(int attribute((unused)) nargs, | |
165 | char **args, | |
166 | struct sink *output, | |
167 | void attribute((unused)) *u) { | |
168 | int w, p[2], n; | |
169 | char buffer[4096]; | |
170 | pid_t pid; | |
171 | ||
172 | xpipe(p); | |
173 | if(!(pid = xfork())) { | |
174 | exitfn = _exit; | |
175 | xclose(p[0]); | |
176 | xdup2(p[1], 1); | |
177 | xclose(p[1]); | |
178 | execlp("sh", "sh", "-c", args[0], (char *)0); | |
179 | fatal(errno, "error executing sh"); | |
180 | } | |
181 | xclose(p[1]); | |
182 | while((n = read(p[0], buffer, sizeof buffer))) { | |
183 | if(n < 0) { | |
184 | if(errno == EINTR) | |
185 | continue; | |
186 | else | |
187 | fatal(errno, "error reading from pipe"); | |
188 | } | |
189 | if(output->write(output, buffer, n) < 0) | |
190 | return -1; | |
191 | } | |
192 | xclose(p[0]); | |
193 | while((n = waitpid(pid, &w, 0)) < 0 && errno == EINTR) | |
194 | ; | |
195 | if(n < 0) | |
196 | fatal(errno, "error calling waitpid"); | |
197 | if(w) | |
198 | error(0, "shell command '%s' %s", args[0], wstat(w)); | |
199 | return 0; | |
200 | } | |
201 | ||
9faa7a88 | 202 | /* @if{CONDITION}{IF-TRUE}{IF-FALSE}@ |
f640bcb3 RK |
203 | * |
204 | * If CONDITION is "true" then evaluates to IF-TRUE. Otherwise | |
205 | * evaluates to IF-FALSE. The IF-FALSE part is optional. | |
206 | */ | |
207 | static int exp_if(int nargs, | |
208 | const struct mx_node **args, | |
209 | struct sink *output, | |
210 | void *u) { | |
211 | char *s; | |
212 | int rc; | |
213 | ||
b36be3a1 | 214 | if((rc = mx_expandstr(args[0], &s, u, "argument #0 (CONDITION)"))) |
f640bcb3 RK |
215 | return rc; |
216 | if(mx_str2bool(s)) | |
217 | return mx_expand(args[1], output, u); | |
218 | else if(nargs > 2) | |
219 | return mx_expand(args[2], output, u); | |
220 | else | |
221 | return 0; | |
222 | } | |
223 | ||
9faa7a88 | 224 | /* @and{BRANCH}{BRANCH}...@ |
f640bcb3 RK |
225 | * |
226 | * Expands to "true" if all the branches are "true" otherwise to "false". If | |
227 | * there are no brances then the result is "true". Only as many branches as | |
228 | * necessary to compute the answer are evaluated (starting from the first one), | |
229 | * so if later branches have side effects they may not take place. | |
230 | */ | |
231 | static int exp_and(int nargs, | |
232 | const struct mx_node **args, | |
233 | struct sink *output, | |
234 | void *u) { | |
235 | int n, result = 1, rc; | |
b36be3a1 | 236 | char *s, *argname; |
f640bcb3 RK |
237 | |
238 | for(n = 0; n < nargs; ++n) { | |
b36be3a1 RK |
239 | byte_xasprintf(&argname, "argument #%d", n); |
240 | if((rc = mx_expandstr(args[n], &s, u, argname))) | |
f640bcb3 RK |
241 | return rc; |
242 | if(!mx_str2bool(s)) { | |
243 | result = 0; | |
244 | break; | |
245 | } | |
246 | } | |
b36be3a1 | 247 | return mx_bool_result(output, result); |
f640bcb3 RK |
248 | } |
249 | ||
9faa7a88 | 250 | /* @or{BRANCH}{BRANCH}...@ |
f640bcb3 RK |
251 | * |
252 | * Expands to "true" if any of the branches are "true" otherwise to "false". | |
253 | * If there are no brances then the result is "false". Only as many branches | |
254 | * as necessary to compute the answer are evaluated (starting from the first | |
255 | * one), so if later branches have side effects they may not take place. | |
256 | */ | |
257 | static int exp_or(int nargs, | |
258 | const struct mx_node **args, | |
259 | struct sink *output, | |
260 | void *u) { | |
261 | int n, result = 0, rc; | |
b36be3a1 | 262 | char *s, *argname; |
f640bcb3 RK |
263 | |
264 | for(n = 0; n < nargs; ++n) { | |
b36be3a1 RK |
265 | byte_xasprintf(&argname, "argument #%d", n); |
266 | if((rc = mx_expandstr(args[n], &s, u, argname))) | |
f640bcb3 RK |
267 | return rc; |
268 | if(mx_str2bool(s)) { | |
269 | result = 1; | |
270 | break; | |
271 | } | |
272 | } | |
b36be3a1 | 273 | return mx_bool_result(output, result); |
f640bcb3 RK |
274 | } |
275 | ||
9faa7a88 | 276 | /* @not{CONDITION}@ |
f640bcb3 RK |
277 | * |
278 | * Expands to "true" unless CONDITION is "true" in which case "false". | |
279 | */ | |
280 | static int exp_not(int attribute((unused)) nargs, | |
281 | char **args, | |
282 | struct sink *output, | |
283 | void attribute((unused)) *u) { | |
b36be3a1 | 284 | return mx_bool_result(output, !mx_str2bool(args[0])); |
f640bcb3 RK |
285 | } |
286 | ||
9faa7a88 | 287 | /* @#{...}@ |
f640bcb3 RK |
288 | * |
289 | * Expands to nothing. The argument(s) are not fully evaluated, and no side | |
290 | * effects occur. | |
291 | */ | |
292 | static int exp_comment(int attribute((unused)) nargs, | |
293 | const struct mx_node attribute((unused)) **args, | |
294 | struct sink attribute((unused)) *output, | |
295 | void attribute((unused)) *u) { | |
296 | return 0; | |
297 | } | |
298 | ||
9faa7a88 | 299 | /* @urlquote{STRING}@ |
f640bcb3 RK |
300 | * |
301 | * URL-quotes a string, i.e. replaces any characters not safe to use unquoted | |
302 | * in a URL with %-encoded form. | |
303 | */ | |
304 | static int exp_urlquote(int attribute((unused)) nargs, | |
305 | char **args, | |
306 | struct sink *output, | |
307 | void attribute((unused)) *u) { | |
308 | if(sink_writes(output, urlencodestring(args[0])) < 0) | |
309 | return -1; | |
310 | else | |
311 | return 0; | |
312 | } | |
313 | ||
9faa7a88 | 314 | /* @eq{S1}{S2}...@ |
b36be3a1 RK |
315 | * |
316 | * Expands to "true" if all the arguments are identical, otherwise to "false" | |
317 | * (i.e. if any pair of arguments differs). | |
318 | * | |
319 | * If there are no arguments then expands to "true". Evaluates all arguments | |
320 | * (with their side effects) even if that's not strictly necessary to discover | |
321 | * the result. | |
322 | */ | |
323 | static int exp_eq(int nargs, | |
324 | char **args, | |
325 | struct sink *output, | |
326 | void attribute((unused)) *u) { | |
327 | int n, result = 1; | |
328 | ||
329 | for(n = 1; n < nargs; ++n) { | |
330 | if(strcmp(args[n], args[0])) { | |
331 | result = 0; | |
332 | break; | |
333 | } | |
334 | } | |
335 | return mx_bool_result(output, result); | |
336 | } | |
337 | ||
9faa7a88 | 338 | /* @ne{S1}{S2}...@ |
b36be3a1 RK |
339 | * |
340 | * Expands to "true" if all of the arguments differ from one another, otherwise | |
341 | * to "false" (i.e. if any value appears more than once). | |
342 | * | |
343 | * If there are no arguments then expands to "true". Evaluates all arguments | |
344 | * (with their side effects) even if that's not strictly necessary to discover | |
345 | * the result. | |
346 | */ | |
347 | static int exp_ne(int nargs, | |
348 | char **args, | |
349 | struct sink *output, | |
350 | void attribute((unused))*u) { | |
351 | hash *h = hash_new(sizeof (char *)); | |
352 | int n, result = 1; | |
353 | ||
354 | for(n = 0; n < nargs; ++n) | |
355 | if(hash_add(h, args[n], "", HASH_INSERT)) { | |
356 | result = 0; | |
357 | break; | |
358 | } | |
359 | return mx_bool_result(output, result); | |
360 | } | |
361 | ||
9faa7a88 | 362 | /* @discard{...}@ |
b36be3a1 RK |
363 | * |
364 | * Expands to nothing. Unlike the comment expansion @#{...}, side effects of | |
365 | * arguments are not suppressed. So this can be used to surround a collection | |
366 | * of macro definitions with whitespace, free text commentary, etc. | |
367 | */ | |
368 | static int exp_discard(int attribute((unused)) nargs, | |
369 | char attribute((unused)) **args, | |
370 | struct sink attribute((unused)) *output, | |
371 | void attribute((unused)) *u) { | |
372 | return 0; | |
373 | } | |
374 | ||
9faa7a88 | 375 | /* @define{NAME}{ARG1 ARG2...}{DEFINITION}@ |
b36be3a1 RK |
376 | * |
377 | * Define a macro. The macro will be called NAME and will act like an | |
378 | * expansion. When it is expanded, the expansion is replaced by DEFINITION, | |
379 | * with each occurence of @ARG1@ etc replaced by the parameters to the | |
380 | * expansion. | |
381 | */ | |
382 | static int exp_define(int attribute((unused)) nargs, | |
383 | const struct mx_node **args, | |
384 | struct sink attribute((unused)) *output, | |
385 | void attribute((unused)) *u) { | |
386 | char **as, *name, *argnames; | |
387 | int rc, nas; | |
388 | ||
389 | if((rc = mx_expandstr(args[0], &name, u, "argument #0 (NAME)"))) | |
390 | return rc; | |
391 | if((rc = mx_expandstr(args[1], &argnames, u, "argument #1 (ARGS)"))) | |
392 | return rc; | |
393 | as = split(argnames, &nas, 0, 0, 0); | |
394 | mx_register_macro(name, nas, as, args[2]); | |
395 | return 0; | |
396 | } | |
397 | ||
dd0f422a | 398 | /** @brief Register built-in expansions */ |
f640bcb3 | 399 | void mx_register_builtin(void) { |
b36be3a1 RK |
400 | mx_register_magic("#", 0, INT_MAX, exp_comment); |
401 | mx_register_magic("and", 0, INT_MAX, exp_and); | |
402 | mx_register_magic("define", 3, 3, exp_define); | |
403 | mx_register_magic("if", 2, 3, exp_if); | |
404 | mx_register_magic("or", 0, INT_MAX, exp_or); | |
405 | mx_register("discard", 0, INT_MAX, exp_discard); | |
406 | mx_register("eq", 0, INT_MAX, exp_eq); | |
f640bcb3 | 407 | mx_register("include", 1, 1, exp_include); |
b36be3a1 | 408 | mx_register("ne", 0, INT_MAX, exp_ne); |
f640bcb3 | 409 | mx_register("not", 1, 1, exp_not); |
b36be3a1 | 410 | mx_register("shell", 1, 1, exp_shell); |
f640bcb3 | 411 | mx_register("urlquote", 1, 1, exp_urlquote); |
f640bcb3 RK |
412 | } |
413 | ||
dd0f422a RK |
414 | /** @brief Add a directory to the search path |
415 | * @param s Directory to add | |
416 | */ | |
417 | void mx_search_path(const char *s) { | |
418 | vector_append(&include_path, xstrdup(s)); | |
419 | } | |
420 | ||
f640bcb3 RK |
421 | /* |
422 | Local Variables: | |
423 | c-basic-offset:2 | |
424 | comment-column:40 | |
425 | fill-column:79 | |
426 | indent-tabs-mode:nil | |
427 | End: | |
428 | */ |