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1dcdf455 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.c | |
22 | * @brief Macro expansion | |
23 | */ | |
24 | ||
25 | #include <config.h> | |
26 | #include "types.h" | |
27 | ||
28 | #include <string.h> | |
29 | #include <ctype.h> | |
30 | #include <assert.h> | |
f640bcb3 RK |
31 | #include <stdio.h> |
32 | #include <sys/stat.h> | |
33 | #include <fcntl.h> | |
34 | #include <unistd.h> | |
35 | #include <errno.h> | |
1dcdf455 RK |
36 | |
37 | #include "macros.h" | |
38 | #include "mem.h" | |
39 | #include "vector.h" | |
40 | #include "log.h" | |
f640bcb3 RK |
41 | #include "hash.h" |
42 | #include "sink.h" | |
43 | #include "syscalls.h" | |
b36be3a1 | 44 | #include "printf.h" |
1dcdf455 RK |
45 | |
46 | VECTOR_TYPE(mx_node_vector, const struct mx_node *, xrealloc); | |
47 | ||
f640bcb3 RK |
48 | /** @brief Definition of an expansion */ |
49 | struct expansion { | |
50 | /** @brief Minimum permitted arguments */ | |
51 | int min; | |
52 | ||
53 | /** @brief Maximum permitted arguments */ | |
54 | int max; | |
55 | ||
b36be3a1 RK |
56 | /** @brief Flags |
57 | * | |
58 | * See: | |
59 | * - @ref EXP_SIMPLE | |
60 | * - @ref EXP_MAGIC | |
61 | * - @ref EXP_MACRO | |
62 | * - @ref EXP_TYPE_MASK | |
63 | */ | |
f640bcb3 RK |
64 | unsigned flags; |
65 | ||
b36be3a1 RK |
66 | /** @brief Macro argument names */ |
67 | char **args; | |
68 | ||
69 | /** @brief Callback (cast to appropriate type) | |
70 | * | |
71 | * Cast to @ref mx_simple_callback or @ref mx_magic_callback as required. */ | |
f640bcb3 | 72 | void (*callback)(); |
b36be3a1 RK |
73 | |
74 | /** @brief Macro definition | |
75 | * | |
76 | * Only for @ref EXP_MACRO expansions. */ | |
77 | const struct mx_node *definition; | |
f640bcb3 RK |
78 | }; |
79 | ||
b36be3a1 RK |
80 | /** @brief Expansion takes pre-expanded strings |
81 | * | |
82 | * @p callback is cast to @ref mx_simple_callback. */ | |
83 | #define EXP_SIMPLE 0x0000 | |
84 | ||
85 | /** @brief Expansion takes parsed templates, not strings | |
86 | * | |
87 | * @p callback is cast to @ref mx_magic_callback. The callback must do its own | |
88 | * expansion e.g. via mx_expandstr() where necessary. */ | |
f640bcb3 RK |
89 | #define EXP_MAGIC 0x0001 |
90 | ||
b36be3a1 RK |
91 | /** @brief Expansion is a macro */ |
92 | #define EXP_MACRO 0x0002 | |
93 | ||
94 | /** @brief Mask of types */ | |
95 | #define EXP_TYPE_MASK 0x0003 | |
96 | ||
97 | /** @brief Hash of all expansions | |
98 | * | |
99 | * Created by mx_register(), mx_register_macro() or mx_register_magic(). | |
100 | */ | |
f640bcb3 RK |
101 | static hash *expansions; |
102 | ||
b36be3a1 RK |
103 | static int mx__expand_macro(const struct expansion *e, |
104 | const struct mx_node *m, | |
105 | struct sink *output, | |
106 | void *u); | |
107 | ||
f640bcb3 RK |
108 | /* Parsing ------------------------------------------------------------------ */ |
109 | ||
1dcdf455 RK |
110 | /** @brief Parse a template |
111 | * @param filename Input filename (for diagnostics) | |
112 | * @param line Line number (use 1 on initial call) | |
113 | * @param input Start of text to parse | |
114 | * @param end End of text to parse or NULL | |
115 | * @return Pointer to parse tree root node | |
116 | * | |
117 | * Parses the text in [start, end) and returns an (immutable) parse | |
118 | * tree representing it. | |
119 | * | |
120 | * If @p end is NULL then the whole string is parsed. | |
121 | * | |
122 | * Note that the @p filename value stored in the parse tree is @p filename, | |
123 | * i.e. it is not copied. | |
124 | */ | |
125 | const struct mx_node *mx_parse(const char *filename, | |
126 | int line, | |
127 | const char *input, | |
128 | const char *end) { | |
129 | int braces, expansion_start_line, argument_start_line; | |
130 | const char *argument_start, *argument_end, *p; | |
131 | struct mx_node_vector v[1]; | |
132 | struct dynstr d[1]; | |
133 | struct mx_node *head = 0, **tailp = &head, *e; | |
134 | int omitted_terminator; | |
135 | ||
136 | if(!end) | |
137 | end = input + strlen(input); | |
138 | while(input < end) { | |
139 | if(*input != '@') { | |
140 | expansion_start_line = line; | |
141 | dynstr_init(d); | |
142 | /* Gather up text without any expansions in. */ | |
143 | while(input < end && *input != '@') { | |
144 | if(*input == '\n') | |
145 | ++line; | |
146 | dynstr_append(d, *input++); | |
147 | } | |
148 | dynstr_terminate(d); | |
149 | e = xmalloc(sizeof *e); | |
150 | e->next = 0; | |
151 | e->filename = filename; | |
152 | e->line = expansion_start_line; | |
153 | e->type = MX_TEXT; | |
154 | e->text = d->vec; | |
155 | *tailp = e; | |
156 | tailp = &e->next; | |
157 | continue; | |
158 | } | |
159 | mx_node_vector_init(v); | |
160 | braces = 0; | |
161 | p = input; | |
162 | ++input; | |
163 | expansion_start_line = line; | |
164 | omitted_terminator = 0; | |
165 | while(!omitted_terminator && input < end && *input != '@') { | |
166 | /* Skip whitespace */ | |
167 | if(isspace((unsigned char)*input)) { | |
168 | if(*input == '\n') | |
169 | ++line; | |
170 | ++input; | |
171 | continue; | |
172 | } | |
173 | if(*input == '{') { | |
174 | /* This is a bracketed argument. We'll walk over it counting | |
175 | * braces to figure out where the end is. */ | |
176 | ++input; | |
177 | argument_start = input; | |
178 | argument_start_line = line; | |
179 | while(input < end && (*input != '}' || braces > 0)) { | |
180 | switch(*input++) { | |
181 | case '{': ++braces; break; | |
182 | case '}': --braces; break; | |
183 | case '\n': ++line; break; | |
184 | } | |
185 | } | |
186 | /* If we run out of input without seeing a '}' that's an error */ | |
187 | if(input >= end) | |
188 | fatal(0, "%s:%d: unterminated expansion '%.*s'", | |
189 | filename, argument_start_line, | |
190 | (int)(input - argument_start), argument_start); | |
191 | /* Consistency check */ | |
192 | assert(*input == '}'); | |
193 | /* Record the end of the argument */ | |
194 | argument_end = input; | |
195 | /* Step over the '}' */ | |
196 | ++input; | |
197 | if(input < end && isspace((unsigned char)*input)) { | |
198 | /* There is at least some whitespace after the '}'. Look | |
199 | * ahead and see what is after all the whitespace. */ | |
200 | for(p = input; p < end && isspace((unsigned char)*p); ++p) | |
201 | ; | |
202 | /* Now we are looking after the whitespace. If it's | |
203 | * anything other than '{', including the end of the input, | |
204 | * then we infer that this expansion finished at the '}' we | |
205 | * just saw. (NB that we don't move input forward to p - | |
206 | * the whitespace is NOT part of the expansion.) */ | |
207 | if(p == end || *p != '{') | |
208 | omitted_terminator = 1; | |
209 | } | |
210 | } else { | |
211 | /* We are looking at an unbracketed argument. (A common example would | |
212 | * be the expansion or macro name.) This is terminated by an '@' | |
213 | * (indicating the end of the expansion), a ':' (allowing a subsequent | |
214 | * unbracketed argument) or a '{' (allowing a bracketed argument). The | |
215 | * end of the input will also do. */ | |
216 | argument_start = input; | |
217 | argument_start_line = line; | |
218 | while(input < end | |
219 | && *input != '@' && *input != '{' && *input != ':') { | |
220 | if(*input == '\n') ++line; | |
221 | ++input; | |
222 | } | |
223 | argument_end = input; | |
224 | /* Trailing whitespace is not significant in unquoted arguments (and | |
225 | * leading whitespace is eliminated by the whitespace skip above). */ | |
226 | while(argument_end > argument_start | |
227 | && isspace((unsigned char)argument_end[-1])) | |
228 | --argument_end; | |
229 | /* Step over the ':' if that's what we see */ | |
230 | if(input < end && *input == ':') | |
231 | ++input; | |
232 | } | |
233 | /* Now we have an argument in [argument_start, argument_end), and we know | |
234 | * its filename and initial line number. This is sufficient to parse | |
235 | * it. */ | |
236 | mx_node_vector_append(v, mx_parse(filename, argument_start_line, | |
237 | argument_start, argument_end)); | |
238 | } | |
239 | /* We're at the end of an expansion. We might have hit the end of the | |
240 | * input, we might have hit an '@' or we might have matched the | |
241 | * omitted_terminator criteria. */ | |
242 | if(input < end) { | |
243 | if(!omitted_terminator) { | |
244 | assert(*input == '@'); | |
245 | ++input; | |
246 | } | |
247 | } | |
248 | /* @@ terminates this file */ | |
249 | if(v->nvec == 0) | |
250 | break; | |
251 | /* Currently we require that the first element, the expansion name, is | |
252 | * always plain text. Removing this restriction would raise some | |
253 | * interesting possibilities but for the time being it is considered an | |
254 | * error. */ | |
255 | if(v->vec[0]->type != MX_TEXT) | |
256 | fatal(0, "%s:%d: expansion names may not themselves contain expansions", | |
257 | v->vec[0]->filename, v->vec[0]->line); | |
258 | /* Guarantee a NULL terminator (for the case where there's more than one | |
259 | * argument) */ | |
260 | mx_node_vector_terminate(v); | |
261 | e = xmalloc(sizeof *e); | |
262 | e->next = 0; | |
263 | e->filename = filename; | |
264 | e->line = expansion_start_line; | |
265 | e->type = MX_EXPANSION; | |
266 | e->name = v->vec[0]->text; | |
267 | e->nargs = v->nvec - 1; | |
268 | e->args = v->nvec > 1 ? &v->vec[1] : 0; | |
269 | *tailp = e; | |
270 | tailp = &e->next; | |
271 | } | |
272 | return head; | |
273 | } | |
274 | ||
9dbb630e RK |
275 | static void mx__dump(struct dynstr *d, const struct mx_node *m) { |
276 | int n; | |
277 | ||
278 | if(!m) | |
279 | return; | |
280 | switch(m->type) { | |
281 | case MX_TEXT: | |
282 | dynstr_append_string(d, m->text); | |
283 | break; | |
284 | case MX_EXPANSION: | |
285 | dynstr_append(d, '@'); | |
286 | dynstr_append_string(d, m->name); | |
287 | for(n = 0; n < m->nargs; ++n) { | |
288 | dynstr_append(d, '{'); | |
289 | mx__dump(d, m->args[n]); | |
290 | dynstr_append(d, '}'); | |
291 | } | |
292 | dynstr_append(d, '@'); | |
293 | break; | |
294 | default: | |
295 | assert(!"invalid m->type"); | |
296 | } | |
297 | mx__dump(d, m->next); | |
298 | } | |
299 | ||
300 | /** @brief Dump a parse macro expansion to a string */ | |
301 | char *mx_dump(const struct mx_node *m) { | |
302 | struct dynstr d[1]; | |
303 | ||
304 | dynstr_init(d); | |
305 | mx__dump(d, m); | |
306 | dynstr_terminate(d); | |
307 | return d->vec; | |
308 | } | |
309 | ||
f640bcb3 RK |
310 | /* Expansion registration --------------------------------------------------- */ |
311 | ||
b36be3a1 RK |
312 | static int mx__register(unsigned flags, |
313 | const char *name, | |
314 | int min, | |
315 | int max, | |
316 | char **args, | |
317 | void (*callback)(), | |
318 | const struct mx_node *definition) { | |
f640bcb3 RK |
319 | struct expansion e[1]; |
320 | ||
321 | if(!expansions) | |
322 | expansions = hash_new(sizeof(struct expansion)); | |
323 | e->min = min; | |
324 | e->max = max; | |
325 | e->flags = flags; | |
b36be3a1 | 326 | e->args = args; |
f640bcb3 | 327 | e->callback = callback; |
b36be3a1 RK |
328 | e->definition = definition; |
329 | return hash_add(expansions, name, &e, | |
330 | ((flags & EXP_TYPE_MASK) == EXP_MACRO) | |
331 | ? HASH_INSERT : HASH_INSERT_OR_REPLACE); | |
f640bcb3 RK |
332 | } |
333 | ||
334 | /** @brief Register a simple expansion rule | |
335 | * @param name Name | |
336 | * @param min Minimum number of arguments | |
337 | * @param max Maximum number of arguments | |
338 | * @param callback Callback to write output | |
339 | */ | |
340 | void mx_register(const char *name, | |
341 | int min, | |
342 | int max, | |
343 | mx_simple_callback *callback) { | |
b36be3a1 | 344 | mx__register(EXP_SIMPLE, name, min, max, 0, (void (*)())callback, 0); |
f640bcb3 RK |
345 | } |
346 | ||
347 | /** @brief Register a magic expansion rule | |
348 | * @param name Name | |
349 | * @param min Minimum number of arguments | |
350 | * @param max Maximum number of arguments | |
351 | * @param callback Callback to write output | |
352 | */ | |
b36be3a1 | 353 | void mx_register_magic(const char *name, |
f640bcb3 RK |
354 | int min, |
355 | int max, | |
356 | mx_magic_callback *callback) { | |
b36be3a1 RK |
357 | mx__register(EXP_MAGIC, name, min, max, 0, (void (*)())callback, 0); |
358 | } | |
359 | ||
360 | /** @brief Register a macro | |
361 | * @param name Name | |
362 | * @param nargs Number of arguments | |
363 | * @param args Argument names | |
364 | * @param definition Macro definition | |
365 | * @return 0 on success, negative on error | |
366 | */ | |
367 | int mx_register_macro(const char *name, | |
368 | int nargs, | |
369 | char **args, | |
370 | const struct mx_node *definition) { | |
371 | if(mx__register(EXP_MACRO, name, nargs, nargs, args, 0/*callback*/, | |
372 | definition)) { | |
373 | /* This locates the error to the definition, which may be a line or two | |
374 | * beyond the @define command itself. The backtrace generated by | |
375 | * mx_expand() may help more. */ | |
376 | error(0, "%s:%d: duplicate definition of '%s'", | |
377 | definition->filename, definition->line, name); | |
378 | return -2; | |
379 | } | |
380 | return 0; | |
f640bcb3 RK |
381 | } |
382 | ||
383 | /* Expansion ---------------------------------------------------------------- */ | |
384 | ||
385 | /** @brief Expand a template | |
386 | * @param m Where to start | |
387 | * @param output Where to send output | |
388 | * @param u User data | |
b36be3a1 RK |
389 | * @return 0 on success, non-0 on error |
390 | * | |
391 | * Interpretation of return values: | |
392 | * - 0 means success | |
393 | * - -1 means an error writing to the sink. | |
394 | * - other negative values mean errors generated from with the macro | |
395 | * expansion system | |
396 | * - positive values are reserved for the application | |
f640bcb3 | 397 | * |
b36be3a1 RK |
398 | * If any callback returns non-zero then that value is returned, abandoning |
399 | * further expansion. | |
f640bcb3 RK |
400 | */ |
401 | int mx_expand(const struct mx_node *m, | |
402 | struct sink *output, | |
403 | void *u) { | |
404 | const struct expansion *e; | |
405 | int rc; | |
406 | ||
407 | if(!m) | |
408 | return 0; | |
409 | switch(m->type) { | |
410 | case MX_TEXT: | |
411 | if(sink_writes(output, m->text) < 0) | |
412 | return -1; | |
413 | break; | |
414 | case MX_EXPANSION: | |
b36be3a1 | 415 | rc = 0; |
f640bcb3 RK |
416 | if(!(e = hash_find(expansions, m->name))) { |
417 | error(0, "%s:%d: unknown expansion name '%s'", | |
418 | m->filename, m->line, m->name); | |
419 | if(sink_printf(output, "[[%s unknown]]", m->name) < 0) | |
420 | return -1; | |
421 | } else if(m->nargs < e->min) { | |
422 | error(0, "%s:%d: expansion '%s' requires %d args, only %d given", | |
423 | m->filename, m->line, m->name, e->min, m->nargs); | |
424 | if(sink_printf(output, "[[%s too few args]]", m->name) < 0) | |
425 | return -1; | |
426 | } else if(m->nargs > e->max) { | |
427 | error(0, "%s:%d: expansion '%s' takes at most %d args, but %d given", | |
428 | m->filename, m->line, m->name, e->max, m->nargs); | |
429 | if(sink_printf(output, "[[%s too many args]]", m->name) < 0) | |
430 | return -1; | |
b36be3a1 RK |
431 | } else switch(e->flags & EXP_TYPE_MASK) { |
432 | case EXP_MAGIC: { | |
433 | /* Magic callbacks we can call directly */ | |
434 | rc = ((mx_magic_callback *)e->callback)(m->nargs, | |
435 | m->args, | |
436 | output, | |
437 | u); | |
438 | break; | |
439 | } | |
440 | case EXP_SIMPLE: { | |
441 | /* For simple callbacks we expand their arguments for them. */ | |
442 | char **args = xcalloc(1 + m->nargs, sizeof (char *)), *argname; | |
443 | int n; | |
444 | ||
445 | for(n = 0; n < m->nargs; ++n) { | |
446 | /* Argument numbers are at least clear from looking at the text; | |
447 | * adding names as well would be nice. TODO */ | |
448 | byte_xasprintf(&argname, "argument #%d", n); | |
449 | if((rc = mx_expandstr(m->args[n], &args[n], u, argname))) | |
450 | break; | |
451 | } | |
452 | if(!rc) { | |
453 | args[n] = NULL; | |
454 | rc = ((mx_simple_callback *)e->callback)(m->nargs, | |
f640bcb3 RK |
455 | args, |
456 | output, | |
b36be3a1 RK |
457 | u); |
458 | } | |
459 | break; | |
460 | } | |
461 | case EXP_MACRO: { | |
462 | /* Macros we expand by rewriting their definition with argument values | |
463 | * substituted and then expanding that. */ | |
464 | rc = mx__expand_macro(e, m, output, u); | |
465 | break; | |
466 | } | |
467 | default: | |
468 | assert(!"impossible EXP_TYPE_MASK value"); | |
469 | } | |
470 | if(rc) { | |
471 | /* For non-IO errors we generate some backtrace */ | |
472 | if(rc != -1) | |
473 | error(0, " ...in '%s' at %s:%d", | |
474 | m->name, m->filename, m->line); | |
475 | return rc; | |
f640bcb3 RK |
476 | } |
477 | break; | |
478 | default: | |
479 | assert(!"invalid m->type"); | |
480 | } | |
b36be3a1 | 481 | return mx_expand(m->next, output, u); |
f640bcb3 RK |
482 | } |
483 | ||
484 | /** @brief Expand a template storing the result in a string | |
485 | * @param m Where to start | |
486 | * @param sp Where to store string | |
487 | * @param u User data | |
b36be3a1 | 488 | * @param what Token for backtrace, or NULL |
f640bcb3 RK |
489 | * @return 0 on success, non-0 on error |
490 | * | |
491 | * Same return conventions as mx_expand(). This wrapper is slightly more | |
492 | * convenient to use from 'magic' expansions. | |
493 | */ | |
494 | int mx_expandstr(const struct mx_node *m, | |
495 | char **sp, | |
b36be3a1 RK |
496 | void *u, |
497 | const char *what) { | |
f640bcb3 RK |
498 | struct dynstr d[1]; |
499 | int rc; | |
500 | ||
b36be3a1 | 501 | dynstr_init(d); |
f640bcb3 RK |
502 | if(!(rc = mx_expand(m, sink_dynstr(d), u))) { |
503 | dynstr_terminate(d); | |
504 | *sp = d->vec; | |
b36be3a1 RK |
505 | } else |
506 | *sp = 0; | |
507 | if(rc && rc != -1 && what) | |
508 | error(0, " ...in %s at %s:%d", what, m->filename, m->line); | |
f640bcb3 RK |
509 | return rc; |
510 | } | |
511 | ||
512 | /** @brief Expand a template file | |
513 | * @param path Filename | |
514 | * @param output Where to send output | |
515 | * @param u User data | |
516 | * @return 0 on success, non-0 on error | |
517 | * | |
518 | * Same return conventions as mx_expand(). | |
519 | */ | |
520 | int mx_expand_file(const char *path, | |
521 | struct sink *output, | |
522 | void *u) { | |
b36be3a1 | 523 | int fd, n, rc; |
f640bcb3 RK |
524 | struct stat sb; |
525 | char *b; | |
526 | off_t sofar; | |
b36be3a1 | 527 | const struct mx_node *m; |
f640bcb3 RK |
528 | |
529 | if((fd = open(path, O_RDONLY)) < 0) | |
530 | fatal(errno, "error opening %s", path); | |
531 | if(fstat(fd, &sb) < 0) | |
532 | fatal(errno, "error statting %s", path); | |
533 | if(!S_ISREG(sb.st_mode)) | |
534 | fatal(0, "%s: not a regular file", path); | |
535 | sofar = 0; | |
536 | b = xmalloc_noptr(sb.st_size); | |
537 | while(sofar < sb.st_size) { | |
538 | n = read(fd, b + sofar, sb.st_size - sofar); | |
539 | if(n > 0) | |
540 | sofar += n; | |
541 | else if(n == 0) | |
542 | fatal(0, "unexpected EOF reading %s", path); | |
543 | else if(errno != EINTR) | |
544 | fatal(errno, "error reading %s", path); | |
545 | } | |
546 | xclose(fd); | |
b36be3a1 RK |
547 | m = mx_parse(path, 1, b, b + sb.st_size); |
548 | rc = mx_expand(m, output, u); | |
549 | if(rc && rc != -1) | |
550 | /* Mention inclusion in backtrace */ | |
551 | error(0, " ...in inclusion of file '%s'", path); | |
552 | return rc; | |
553 | } | |
554 | ||
555 | /** @brief Rewrite a parse tree substituting in macro arguments | |
556 | * @param m Parse tree to rewrite (from macro definition) | |
557 | * @param h Hash mapping argument names to argument values | |
558 | * @return Rewritten parse tree | |
559 | */ | |
c617bac5 | 560 | static const struct mx_node *mx__rewrite(const struct mx_node *definition, |
b36be3a1 | 561 | hash *h) { |
c617bac5 | 562 | const struct mx_node *head = 0, **tailp = &head, *argvalue, *m, *mm; |
b36be3a1 RK |
563 | struct mx_node *nm; |
564 | int n; | |
565 | ||
c617bac5 | 566 | for(m = definition; m; m = m->next) { |
b36be3a1 RK |
567 | switch(m->type) { |
568 | case MX_TEXT: | |
569 | nm = xmalloc(sizeof *nm); | |
570 | *nm = *m; /* Dumb copy of text node fields */ | |
571 | nm->next = 0; /* Maintain list structure */ | |
572 | *tailp = nm; | |
573 | tailp = (const struct mx_node **)&nm->next; | |
574 | break; | |
575 | case MX_EXPANSION: | |
576 | if(m->nargs == 0 | |
8fc93a37 | 577 | && (argvalue = *(const struct mx_node **)hash_find(h, m->name))) { |
b36be3a1 RK |
578 | /* This expansion has no arguments and its name matches one of the |
579 | * macro arguments. (Even if it's a valid expansion name we override | |
580 | * it.) We insert its value at this point. We do NOT recursively | |
581 | * rewrite the argument's value - it is outside the lexical scope of | |
582 | * the argument name. | |
583 | * | |
584 | * We need to recreate the list structure but a shallow copy will | |
585 | * suffice here. | |
586 | */ | |
8fc93a37 | 587 | for(mm = argvalue; mm; mm = mm->next) { |
b36be3a1 RK |
588 | nm = xmalloc(sizeof *nm); |
589 | *nm = *mm; | |
590 | nm->next = 0; | |
591 | *tailp = nm; | |
592 | tailp = (const struct mx_node **)&nm->next; | |
593 | } | |
594 | } else { | |
595 | /* This is some other expansion. We recursively rewrite its argument | |
596 | * values according to h. */ | |
597 | nm = xmalloc(sizeof *nm); | |
8fc93a37 | 598 | *nm = *m; |
c617bac5 | 599 | nm->args = xcalloc(nm->nargs, sizeof (struct mx_node *)); |
b36be3a1 RK |
600 | for(n = 0; n < nm->nargs; ++n) |
601 | nm->args[n] = mx__rewrite(m->args[n], h); | |
602 | nm->next = 0; | |
603 | *tailp = nm; | |
604 | tailp = (const struct mx_node **)&nm->next; | |
605 | } | |
606 | break; | |
607 | default: | |
608 | assert(!"invalid m->type"); | |
609 | } | |
610 | } | |
611 | *tailp = 0; /* Mark end of list */ | |
612 | return head; | |
613 | } | |
614 | ||
615 | /** @brief Expand a macro | |
616 | * @param e Macro definition | |
617 | * @param m Macro expansion | |
618 | * @param output Where to send output | |
619 | * @param u User data | |
620 | * @return 0 on success, non-0 on error | |
621 | */ | |
622 | static int mx__expand_macro(const struct expansion *e, | |
623 | const struct mx_node *m, | |
624 | struct sink *output, | |
625 | void *u) { | |
626 | hash *h = hash_new(sizeof (struct mx_node *)); | |
627 | int n; | |
628 | ||
629 | /* We store the macro arguments in a hash. Currently there is no check for | |
630 | * duplicate argument names (and this would be the wrong place for it | |
631 | * anyway); if you do that you just lose in some undefined way. */ | |
632 | for(n = 0; n < m->nargs; ++n) | |
8fc93a37 | 633 | hash_add(h, e->args[n], &m->args[n], HASH_INSERT); |
b36be3a1 RK |
634 | /* Generate a rewritten parse tree */ |
635 | m = mx__rewrite(e->definition, h); | |
636 | /* Expand the result */ | |
637 | return mx_expand(m, output, u); | |
638 | /* mx_expand() will update the backtrace */ | |
f640bcb3 RK |
639 | } |
640 | ||
1dcdf455 RK |
641 | /* |
642 | Local Variables: | |
643 | c-basic-offset:2 | |
644 | comment-column:40 | |
645 | fill-column:79 | |
646 | indent-tabs-mode:nil | |
647 | End: | |
648 | */ |