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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 | 36 | |
9faa7a88 | 37 | #include "hash.h" |
1dcdf455 RK |
38 | #include "macros.h" |
39 | #include "mem.h" | |
40 | #include "vector.h" | |
41 | #include "log.h" | |
f640bcb3 RK |
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 | ||
f5fdc06f RK |
110 | static int next_non_whitespace(const char *input, |
111 | const char *end) { | |
112 | while(input < end && isspace((unsigned char)*input)) | |
113 | ++input; | |
114 | return input < end ? *input : -1; | |
115 | } | |
116 | ||
1dcdf455 RK |
117 | /** @brief Parse a template |
118 | * @param filename Input filename (for diagnostics) | |
119 | * @param line Line number (use 1 on initial call) | |
120 | * @param input Start of text to parse | |
121 | * @param end End of text to parse or NULL | |
122 | * @return Pointer to parse tree root node | |
123 | * | |
124 | * Parses the text in [start, end) and returns an (immutable) parse | |
125 | * tree representing it. | |
126 | * | |
127 | * If @p end is NULL then the whole string is parsed. | |
128 | * | |
129 | * Note that the @p filename value stored in the parse tree is @p filename, | |
130 | * i.e. it is not copied. | |
131 | */ | |
132 | const struct mx_node *mx_parse(const char *filename, | |
133 | int line, | |
134 | const char *input, | |
135 | const char *end) { | |
f5fdc06f RK |
136 | int braces, argument_start_line, obracket, cbracket; |
137 | const char *argument_start, *argument_end; | |
1dcdf455 RK |
138 | struct mx_node_vector v[1]; |
139 | struct dynstr d[1]; | |
140 | struct mx_node *head = 0, **tailp = &head, *e; | |
1dcdf455 RK |
141 | |
142 | if(!end) | |
143 | end = input + strlen(input); | |
144 | while(input < end) { | |
145 | if(*input != '@') { | |
f5fdc06f RK |
146 | e = xmalloc(sizeof *e); |
147 | e->next = 0; | |
148 | e->filename = filename; | |
149 | e->line = line; | |
150 | e->type = MX_TEXT; | |
1dcdf455 RK |
151 | dynstr_init(d); |
152 | /* Gather up text without any expansions in. */ | |
153 | while(input < end && *input != '@') { | |
154 | if(*input == '\n') | |
155 | ++line; | |
156 | dynstr_append(d, *input++); | |
157 | } | |
158 | dynstr_terminate(d); | |
1dcdf455 RK |
159 | e->text = d->vec; |
160 | *tailp = e; | |
161 | tailp = &e->next; | |
162 | continue; | |
163 | } | |
f5fdc06f RK |
164 | if(input + 1 < end) |
165 | switch(input[1]) { | |
166 | case '@': | |
167 | /* '@@' expands to '@' */ | |
168 | e = xmalloc(sizeof *e); | |
169 | e->next = 0; | |
170 | e->filename = filename; | |
171 | e->line = line; | |
172 | e->type = MX_TEXT; | |
173 | e->text = "@"; | |
174 | *tailp = e; | |
175 | tailp = &e->next; | |
176 | input += 2; | |
177 | continue; | |
178 | case '#': | |
179 | /* '@#' starts a (newline-eating comment), like dnl */ | |
180 | input += 2; | |
181 | while(input < end && *input != '\n') | |
182 | ++input; | |
183 | if(*input == '\n') { | |
184 | ++line; | |
185 | ++input; | |
186 | } | |
187 | continue; | |
188 | case '_': | |
189 | /* '@_' expands to nothing. It's there to allow dump to terminate | |
190 | * expansions without having to know what follows. */ | |
191 | input += 2; | |
192 | continue; | |
1dcdf455 | 193 | } |
f5fdc06f RK |
194 | /* It's a full expansion */ |
195 | ++input; | |
196 | e = xmalloc(sizeof *e); | |
197 | e->next = 0; | |
198 | e->filename = filename; | |
199 | e->line = line; | |
200 | e->type = MX_EXPANSION; | |
201 | /* Collect the expansion name. Expansion names start with an alnum and | |
202 | * consist of alnums and '-'. We don't permit whitespace between the '@' | |
203 | * and the name. */ | |
204 | dynstr_init(d); | |
205 | if(input == end || !isalnum((unsigned char)*input)) | |
206 | fatal(0, "%s:%d: invalid expansion", filename, e->line); | |
207 | while(input < end && (isalnum((unsigned char)*input) || *input == '-')) | |
208 | dynstr_append(d, *input++); | |
209 | dynstr_terminate(d); | |
210 | e->name = d->vec; | |
211 | /* See what the bracket character is */ | |
212 | obracket = next_non_whitespace(input, end); | |
213 | switch(obracket) { | |
214 | case '(': cbracket = ')'; break; | |
215 | case '[': cbracket = ']'; break; | |
216 | case '{': cbracket = '}'; break; | |
217 | default: obracket = -1; break; /* no arguments */ | |
218 | } | |
219 | mx_node_vector_init(v); | |
220 | if(obracket >= 0) { | |
221 | /* Gather up arguments */ | |
222 | while(next_non_whitespace(input, end) == obracket) { | |
223 | while(isspace((unsigned char)*input)) { | |
224 | if(*input == '\n') | |
225 | ++line; | |
226 | ++input; | |
227 | } | |
228 | ++input; /* the bracket */ | |
229 | braces = 0; | |
230 | /* Find the end of the argument */ | |
231 | argument_start = input; | |
232 | argument_start_line = line; | |
233 | while(input < end && (*input != cbracket || braces > 0)) { | |
234 | const int c = *input++; | |
235 | ||
236 | if(c == obracket) | |
237 | ++braces; | |
238 | else if(c == cbracket) | |
239 | --braces; | |
240 | else if(c == '\n') | |
241 | ++line; | |
242 | } | |
243 | if(input >= end) { | |
244 | /* We ran out of input without encountering a balanced cbracket */ | |
245 | fatal(0, "%s:%d: unterminated expansion argument '%.*s'", | |
1dcdf455 RK |
246 | filename, argument_start_line, |
247 | (int)(input - argument_start), argument_start); | |
f5fdc06f | 248 | } |
1dcdf455 | 249 | /* Consistency check */ |
f5fdc06f | 250 | assert(*input == cbracket); |
1dcdf455 RK |
251 | /* Record the end of the argument */ |
252 | argument_end = input; | |
f5fdc06f | 253 | /* Step over the cbracket */ |
1dcdf455 | 254 | ++input; |
f5fdc06f RK |
255 | /* Now we have an argument in [argument_start, argument_end), and we |
256 | * know its filename and initial line number. This is sufficient to | |
257 | * parse it. */ | |
258 | mx_node_vector_append(v, mx_parse(filename, argument_start_line, | |
259 | argument_start, argument_end)); | |
1dcdf455 RK |
260 | } |
261 | } | |
1dcdf455 RK |
262 | /* Guarantee a NULL terminator (for the case where there's more than one |
263 | * argument) */ | |
264 | mx_node_vector_terminate(v); | |
f5fdc06f RK |
265 | /* Fill in the remains of the node */ |
266 | e->nargs = v->nvec; | |
267 | e->args = v->vec; | |
1dcdf455 RK |
268 | *tailp = e; |
269 | tailp = &e->next; | |
270 | } | |
271 | return head; | |
272 | } | |
273 | ||
9dbb630e RK |
274 | static void mx__dump(struct dynstr *d, const struct mx_node *m) { |
275 | int n; | |
f5fdc06f RK |
276 | const struct mx_node *mm; |
277 | ||
9dbb630e RK |
278 | if(!m) |
279 | return; | |
280 | switch(m->type) { | |
281 | case MX_TEXT: | |
f5fdc06f RK |
282 | if(m->text[0] == '@') |
283 | dynstr_append(d, '@'); | |
9dbb630e RK |
284 | dynstr_append_string(d, m->text); |
285 | break; | |
286 | case MX_EXPANSION: | |
287 | dynstr_append(d, '@'); | |
288 | dynstr_append_string(d, m->name); | |
289 | for(n = 0; n < m->nargs; ++n) { | |
290 | dynstr_append(d, '{'); | |
291 | mx__dump(d, m->args[n]); | |
292 | dynstr_append(d, '}'); | |
293 | } | |
f5fdc06f RK |
294 | /* If the next non-whitespace is '{', add @_ to stop it being |
295 | * misinterpreted */ | |
296 | mm = m->next; | |
297 | while(mm && mm->type == MX_TEXT) { | |
298 | switch(next_non_whitespace(mm->text, mm->text + strlen(mm->text))) { | |
299 | case -1: | |
300 | mm = mm->next; | |
301 | continue; | |
302 | case '{': | |
303 | dynstr_append_string(d, "@_"); | |
304 | break; | |
305 | default: | |
306 | break; | |
307 | } | |
308 | break; | |
309 | } | |
9dbb630e RK |
310 | break; |
311 | default: | |
312 | assert(!"invalid m->type"); | |
313 | } | |
314 | mx__dump(d, m->next); | |
315 | } | |
316 | ||
f5fdc06f RK |
317 | /** @brief Dump a parse macro expansion to a string |
318 | * | |
319 | * Not of production quality! Only intended for testing! | |
320 | */ | |
9dbb630e RK |
321 | char *mx_dump(const struct mx_node *m) { |
322 | struct dynstr d[1]; | |
323 | ||
324 | dynstr_init(d); | |
325 | mx__dump(d, m); | |
326 | dynstr_terminate(d); | |
327 | return d->vec; | |
328 | } | |
329 | ||
f640bcb3 RK |
330 | /* Expansion registration --------------------------------------------------- */ |
331 | ||
b36be3a1 RK |
332 | static int mx__register(unsigned flags, |
333 | const char *name, | |
334 | int min, | |
335 | int max, | |
336 | char **args, | |
337 | void (*callback)(), | |
338 | const struct mx_node *definition) { | |
f640bcb3 RK |
339 | struct expansion e[1]; |
340 | ||
341 | if(!expansions) | |
342 | expansions = hash_new(sizeof(struct expansion)); | |
343 | e->min = min; | |
344 | e->max = max; | |
345 | e->flags = flags; | |
b36be3a1 | 346 | e->args = args; |
f640bcb3 | 347 | e->callback = callback; |
b36be3a1 RK |
348 | e->definition = definition; |
349 | return hash_add(expansions, name, &e, | |
350 | ((flags & EXP_TYPE_MASK) == EXP_MACRO) | |
351 | ? HASH_INSERT : HASH_INSERT_OR_REPLACE); | |
f640bcb3 RK |
352 | } |
353 | ||
354 | /** @brief Register a simple expansion rule | |
355 | * @param name Name | |
356 | * @param min Minimum number of arguments | |
357 | * @param max Maximum number of arguments | |
358 | * @param callback Callback to write output | |
359 | */ | |
360 | void mx_register(const char *name, | |
361 | int min, | |
362 | int max, | |
363 | mx_simple_callback *callback) { | |
b36be3a1 | 364 | mx__register(EXP_SIMPLE, name, min, max, 0, (void (*)())callback, 0); |
f640bcb3 RK |
365 | } |
366 | ||
367 | /** @brief Register a magic expansion rule | |
368 | * @param name Name | |
369 | * @param min Minimum number of arguments | |
370 | * @param max Maximum number of arguments | |
371 | * @param callback Callback to write output | |
372 | */ | |
b36be3a1 | 373 | void mx_register_magic(const char *name, |
f640bcb3 RK |
374 | int min, |
375 | int max, | |
376 | mx_magic_callback *callback) { | |
b36be3a1 RK |
377 | mx__register(EXP_MAGIC, name, min, max, 0, (void (*)())callback, 0); |
378 | } | |
379 | ||
380 | /** @brief Register a macro | |
381 | * @param name Name | |
382 | * @param nargs Number of arguments | |
383 | * @param args Argument names | |
384 | * @param definition Macro definition | |
385 | * @return 0 on success, negative on error | |
386 | */ | |
387 | int mx_register_macro(const char *name, | |
388 | int nargs, | |
389 | char **args, | |
390 | const struct mx_node *definition) { | |
391 | if(mx__register(EXP_MACRO, name, nargs, nargs, args, 0/*callback*/, | |
392 | definition)) { | |
393 | /* This locates the error to the definition, which may be a line or two | |
394 | * beyond the @define command itself. The backtrace generated by | |
395 | * mx_expand() may help more. */ | |
396 | error(0, "%s:%d: duplicate definition of '%s'", | |
397 | definition->filename, definition->line, name); | |
398 | return -2; | |
399 | } | |
400 | return 0; | |
f640bcb3 RK |
401 | } |
402 | ||
403 | /* Expansion ---------------------------------------------------------------- */ | |
404 | ||
405 | /** @brief Expand a template | |
406 | * @param m Where to start | |
407 | * @param output Where to send output | |
408 | * @param u User data | |
b36be3a1 RK |
409 | * @return 0 on success, non-0 on error |
410 | * | |
411 | * Interpretation of return values: | |
412 | * - 0 means success | |
413 | * - -1 means an error writing to the sink. | |
414 | * - other negative values mean errors generated from with the macro | |
415 | * expansion system | |
416 | * - positive values are reserved for the application | |
f640bcb3 | 417 | * |
b36be3a1 RK |
418 | * If any callback returns non-zero then that value is returned, abandoning |
419 | * further expansion. | |
f640bcb3 RK |
420 | */ |
421 | int mx_expand(const struct mx_node *m, | |
422 | struct sink *output, | |
423 | void *u) { | |
424 | const struct expansion *e; | |
425 | int rc; | |
426 | ||
427 | if(!m) | |
428 | return 0; | |
429 | switch(m->type) { | |
430 | case MX_TEXT: | |
431 | if(sink_writes(output, m->text) < 0) | |
432 | return -1; | |
433 | break; | |
434 | case MX_EXPANSION: | |
b36be3a1 | 435 | rc = 0; |
f640bcb3 RK |
436 | if(!(e = hash_find(expansions, m->name))) { |
437 | error(0, "%s:%d: unknown expansion name '%s'", | |
438 | m->filename, m->line, m->name); | |
dd0f422a | 439 | if(sink_printf(output, "[['%s' unknown]]", m->name) < 0) |
f640bcb3 RK |
440 | return -1; |
441 | } else if(m->nargs < e->min) { | |
442 | error(0, "%s:%d: expansion '%s' requires %d args, only %d given", | |
443 | m->filename, m->line, m->name, e->min, m->nargs); | |
dd0f422a | 444 | if(sink_printf(output, "[['%s' too few args]]", m->name) < 0) |
f640bcb3 RK |
445 | return -1; |
446 | } else if(m->nargs > e->max) { | |
447 | error(0, "%s:%d: expansion '%s' takes at most %d args, but %d given", | |
448 | m->filename, m->line, m->name, e->max, m->nargs); | |
dd0f422a | 449 | if(sink_printf(output, "[['%s' too many args]]", m->name) < 0) |
f640bcb3 | 450 | return -1; |
b36be3a1 RK |
451 | } else switch(e->flags & EXP_TYPE_MASK) { |
452 | case EXP_MAGIC: { | |
453 | /* Magic callbacks we can call directly */ | |
454 | rc = ((mx_magic_callback *)e->callback)(m->nargs, | |
455 | m->args, | |
456 | output, | |
457 | u); | |
458 | break; | |
459 | } | |
460 | case EXP_SIMPLE: { | |
461 | /* For simple callbacks we expand their arguments for them. */ | |
462 | char **args = xcalloc(1 + m->nargs, sizeof (char *)), *argname; | |
463 | int n; | |
464 | ||
465 | for(n = 0; n < m->nargs; ++n) { | |
466 | /* Argument numbers are at least clear from looking at the text; | |
467 | * adding names as well would be nice. TODO */ | |
468 | byte_xasprintf(&argname, "argument #%d", n); | |
469 | if((rc = mx_expandstr(m->args[n], &args[n], u, argname))) | |
470 | break; | |
471 | } | |
472 | if(!rc) { | |
473 | args[n] = NULL; | |
474 | rc = ((mx_simple_callback *)e->callback)(m->nargs, | |
f640bcb3 RK |
475 | args, |
476 | output, | |
b36be3a1 RK |
477 | u); |
478 | } | |
479 | break; | |
480 | } | |
481 | case EXP_MACRO: { | |
482 | /* Macros we expand by rewriting their definition with argument values | |
483 | * substituted and then expanding that. */ | |
484 | rc = mx__expand_macro(e, m, output, u); | |
485 | break; | |
486 | } | |
487 | default: | |
488 | assert(!"impossible EXP_TYPE_MASK value"); | |
489 | } | |
490 | if(rc) { | |
491 | /* For non-IO errors we generate some backtrace */ | |
492 | if(rc != -1) | |
dd0f422a | 493 | error(0, " ...in @%s at %s:%d", |
b36be3a1 RK |
494 | m->name, m->filename, m->line); |
495 | return rc; | |
f640bcb3 RK |
496 | } |
497 | break; | |
498 | default: | |
499 | assert(!"invalid m->type"); | |
500 | } | |
b36be3a1 | 501 | return mx_expand(m->next, output, u); |
f640bcb3 RK |
502 | } |
503 | ||
504 | /** @brief Expand a template storing the result in a string | |
505 | * @param m Where to start | |
506 | * @param sp Where to store string | |
507 | * @param u User data | |
b36be3a1 | 508 | * @param what Token for backtrace, or NULL |
f640bcb3 RK |
509 | * @return 0 on success, non-0 on error |
510 | * | |
511 | * Same return conventions as mx_expand(). This wrapper is slightly more | |
512 | * convenient to use from 'magic' expansions. | |
513 | */ | |
514 | int mx_expandstr(const struct mx_node *m, | |
515 | char **sp, | |
b36be3a1 RK |
516 | void *u, |
517 | const char *what) { | |
f640bcb3 RK |
518 | struct dynstr d[1]; |
519 | int rc; | |
520 | ||
b36be3a1 | 521 | dynstr_init(d); |
f640bcb3 RK |
522 | if(!(rc = mx_expand(m, sink_dynstr(d), u))) { |
523 | dynstr_terminate(d); | |
524 | *sp = d->vec; | |
b36be3a1 RK |
525 | } else |
526 | *sp = 0; | |
527 | if(rc && rc != -1 && what) | |
528 | error(0, " ...in %s at %s:%d", what, m->filename, m->line); | |
f640bcb3 RK |
529 | return rc; |
530 | } | |
531 | ||
532 | /** @brief Expand a template file | |
533 | * @param path Filename | |
534 | * @param output Where to send output | |
535 | * @param u User data | |
536 | * @return 0 on success, non-0 on error | |
537 | * | |
538 | * Same return conventions as mx_expand(). | |
539 | */ | |
540 | int mx_expand_file(const char *path, | |
541 | struct sink *output, | |
542 | void *u) { | |
b36be3a1 | 543 | int fd, n, rc; |
f640bcb3 RK |
544 | struct stat sb; |
545 | char *b; | |
546 | off_t sofar; | |
b36be3a1 | 547 | const struct mx_node *m; |
f640bcb3 RK |
548 | |
549 | if((fd = open(path, O_RDONLY)) < 0) | |
550 | fatal(errno, "error opening %s", path); | |
551 | if(fstat(fd, &sb) < 0) | |
552 | fatal(errno, "error statting %s", path); | |
553 | if(!S_ISREG(sb.st_mode)) | |
554 | fatal(0, "%s: not a regular file", path); | |
555 | sofar = 0; | |
556 | b = xmalloc_noptr(sb.st_size); | |
557 | while(sofar < sb.st_size) { | |
558 | n = read(fd, b + sofar, sb.st_size - sofar); | |
559 | if(n > 0) | |
560 | sofar += n; | |
561 | else if(n == 0) | |
562 | fatal(0, "unexpected EOF reading %s", path); | |
563 | else if(errno != EINTR) | |
564 | fatal(errno, "error reading %s", path); | |
565 | } | |
566 | xclose(fd); | |
b36be3a1 RK |
567 | m = mx_parse(path, 1, b, b + sb.st_size); |
568 | rc = mx_expand(m, output, u); | |
569 | if(rc && rc != -1) | |
570 | /* Mention inclusion in backtrace */ | |
571 | error(0, " ...in inclusion of file '%s'", path); | |
572 | return rc; | |
573 | } | |
574 | ||
9faa7a88 RK |
575 | /* Macros ------------------------------------------------------------------- */ |
576 | ||
577 | /** @brief Rewrite a parse tree substituting sub-expansions | |
b36be3a1 | 578 | * @param m Parse tree to rewrite (from macro definition) |
9faa7a88 RK |
579 | * @param ... Name/value pairs to rewrite |
580 | * @return Rewritten parse tree | |
581 | * | |
582 | * The name/value pair list consists of pairs of strings and is terminated by | |
583 | * (char *)0. Names and values are both copied so need not survive the call. | |
584 | */ | |
585 | const struct mx_node *mx_rewritel(const struct mx_node *m, | |
586 | ...) { | |
587 | va_list ap; | |
588 | hash *h = hash_new(sizeof (struct mx_node *)); | |
589 | const char *n, *v; | |
590 | struct mx_node *e; | |
591 | ||
592 | va_start(ap, m); | |
593 | while((n = va_arg(ap, const char *))) { | |
594 | v = va_arg(ap, const char *); | |
595 | e = xmalloc(sizeof *e); | |
596 | e->next = 0; | |
597 | e->filename = m->filename; | |
598 | e->line = m->line; | |
599 | e->type = MX_TEXT; | |
600 | e->text = xstrdup(v); | |
601 | hash_add(h, n, &e, HASH_INSERT); | |
602 | /* hash_add() copies n */ | |
603 | } | |
604 | return mx_rewrite(m, h); | |
605 | } | |
606 | ||
607 | /** @brief Rewrite a parse tree substituting in macro arguments | |
608 | * @param definition Parse tree to rewrite (from macro definition) | |
b36be3a1 RK |
609 | * @param h Hash mapping argument names to argument values |
610 | * @return Rewritten parse tree | |
611 | */ | |
9faa7a88 RK |
612 | const struct mx_node *mx_rewrite(const struct mx_node *definition, |
613 | hash *h) { | |
c617bac5 | 614 | const struct mx_node *head = 0, **tailp = &head, *argvalue, *m, *mm; |
b36be3a1 RK |
615 | struct mx_node *nm; |
616 | int n; | |
617 | ||
c617bac5 | 618 | for(m = definition; m; m = m->next) { |
b36be3a1 RK |
619 | switch(m->type) { |
620 | case MX_TEXT: | |
621 | nm = xmalloc(sizeof *nm); | |
622 | *nm = *m; /* Dumb copy of text node fields */ | |
623 | nm->next = 0; /* Maintain list structure */ | |
624 | *tailp = nm; | |
625 | tailp = (const struct mx_node **)&nm->next; | |
626 | break; | |
627 | case MX_EXPANSION: | |
628 | if(m->nargs == 0 | |
8fc93a37 | 629 | && (argvalue = *(const struct mx_node **)hash_find(h, m->name))) { |
b36be3a1 RK |
630 | /* This expansion has no arguments and its name matches one of the |
631 | * macro arguments. (Even if it's a valid expansion name we override | |
632 | * it.) We insert its value at this point. We do NOT recursively | |
633 | * rewrite the argument's value - it is outside the lexical scope of | |
634 | * the argument name. | |
635 | * | |
636 | * We need to recreate the list structure but a shallow copy will | |
637 | * suffice here. | |
638 | */ | |
8fc93a37 | 639 | for(mm = argvalue; mm; mm = mm->next) { |
b36be3a1 RK |
640 | nm = xmalloc(sizeof *nm); |
641 | *nm = *mm; | |
642 | nm->next = 0; | |
643 | *tailp = nm; | |
644 | tailp = (const struct mx_node **)&nm->next; | |
645 | } | |
646 | } else { | |
647 | /* This is some other expansion. We recursively rewrite its argument | |
648 | * values according to h. */ | |
649 | nm = xmalloc(sizeof *nm); | |
8fc93a37 | 650 | *nm = *m; |
c617bac5 | 651 | nm->args = xcalloc(nm->nargs, sizeof (struct mx_node *)); |
b36be3a1 | 652 | for(n = 0; n < nm->nargs; ++n) |
9faa7a88 | 653 | nm->args[n] = mx_rewrite(m->args[n], h); |
b36be3a1 RK |
654 | nm->next = 0; |
655 | *tailp = nm; | |
656 | tailp = (const struct mx_node **)&nm->next; | |
657 | } | |
658 | break; | |
659 | default: | |
660 | assert(!"invalid m->type"); | |
661 | } | |
662 | } | |
663 | *tailp = 0; /* Mark end of list */ | |
664 | return head; | |
665 | } | |
666 | ||
667 | /** @brief Expand a macro | |
668 | * @param e Macro definition | |
669 | * @param m Macro expansion | |
670 | * @param output Where to send output | |
671 | * @param u User data | |
672 | * @return 0 on success, non-0 on error | |
673 | */ | |
674 | static int mx__expand_macro(const struct expansion *e, | |
675 | const struct mx_node *m, | |
676 | struct sink *output, | |
677 | void *u) { | |
678 | hash *h = hash_new(sizeof (struct mx_node *)); | |
679 | int n; | |
680 | ||
681 | /* We store the macro arguments in a hash. Currently there is no check for | |
682 | * duplicate argument names (and this would be the wrong place for it | |
683 | * anyway); if you do that you just lose in some undefined way. */ | |
684 | for(n = 0; n < m->nargs; ++n) | |
8fc93a37 | 685 | hash_add(h, e->args[n], &m->args[n], HASH_INSERT); |
b36be3a1 | 686 | /* Generate a rewritten parse tree */ |
9faa7a88 | 687 | m = mx_rewrite(e->definition, h); |
b36be3a1 RK |
688 | /* Expand the result */ |
689 | return mx_expand(m, output, u); | |
690 | /* mx_expand() will update the backtrace */ | |
f640bcb3 RK |
691 | } |
692 | ||
1dcdf455 RK |
693 | /* |
694 | Local Variables: | |
695 | c-basic-offset:2 | |
696 | comment-column:40 | |
697 | fill-column:79 | |
698 | indent-tabs-mode:nil | |
699 | End: | |
700 | */ |