gnum4.c revision 172261
1/* $OpenBSD: gnum4.c,v 1.18 2002/04/26 16:15:16 espie Exp $ */ 2 3/* 4 * Copyright (c) 1999 Marc Espie 5 * 6 * Redistribution and use in source and binary forms, with or without 7 * modification, are permitted provided that the following conditions 8 * are met: 9 * 1. Redistributions of source code must retain the above copyright 10 * notice, this list of conditions and the following disclaimer. 11 * 2. Redistributions in binary form must reproduce the above copyright 12 * notice, this list of conditions and the following disclaimer in the 13 * documentation and/or other materials provided with the distribution. 14 * 15 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 16 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 17 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 18 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 19 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 20 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 21 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 22 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 23 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 24 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 25 * SUCH DAMAGE. 26 */ 27 28#include <sys/cdefs.h> 29__FBSDID("$FreeBSD: head/usr.bin/m4/gnum4.c 172261 2007-09-21 01:55:11Z kevlo $"); 30 31/* 32 * functions needed to support gnu-m4 extensions, including a fake freezing 33 */ 34 35#include <sys/param.h> 36#include <sys/types.h> 37#include <sys/wait.h> 38#include <ctype.h> 39#include <paths.h> 40#include <regex.h> 41#include <stddef.h> 42#include <stdlib.h> 43#include <stdio.h> 44#include <string.h> 45#include <err.h> 46#include <errno.h> 47#include <unistd.h> 48#include "mdef.h" 49#include "stdd.h" 50#include "extern.h" 51 52 53int mimic_gnu = 0; 54 55/* 56 * Support for include path search 57 * First search in the the current directory. 58 * If not found, and the path is not absolute, include path kicks in. 59 * First, -I options, in the order found on the command line. 60 * Then M4PATH env variable 61 */ 62 63struct path_entry { 64 char *name; 65 struct path_entry *next; 66} *first, *last; 67 68static struct path_entry *new_path_entry(const char *); 69static void ensure_m4path(void); 70static struct input_file *dopath(struct input_file *, const char *); 71 72static struct path_entry * 73new_path_entry(const char *dirname) 74{ 75 struct path_entry *n; 76 77 n = malloc(sizeof(struct path_entry)); 78 if (!n) 79 errx(1, "out of memory"); 80 n->name = strdup(dirname); 81 if (!n->name) 82 errx(1, "out of memory"); 83 n->next = 0; 84 return n; 85} 86 87void 88addtoincludepath(const char *dirname) 89{ 90 struct path_entry *n; 91 92 n = new_path_entry(dirname); 93 94 if (last) { 95 last->next = n; 96 last = n; 97 } 98 else 99 last = first = n; 100} 101 102static void 103ensure_m4path(void) 104{ 105 static int envpathdone = 0; 106 char *envpath; 107 char *sweep; 108 char *path; 109 110 if (envpathdone) 111 return; 112 envpathdone = TRUE; 113 envpath = getenv("M4PATH"); 114 if (!envpath) 115 return; 116 /* for portability: getenv result is read-only */ 117 envpath = strdup(envpath); 118 if (!envpath) 119 errx(1, "out of memory"); 120 for (sweep = envpath; 121 (path = strsep(&sweep, ":")) != NULL;) 122 addtoincludepath(path); 123 free(envpath); 124} 125 126static 127struct input_file * 128dopath(struct input_file *i, const char *filename) 129{ 130 char path[MAXPATHLEN]; 131 struct path_entry *pe; 132 FILE *f; 133 134 for (pe = first; pe; pe = pe->next) { 135 snprintf(path, sizeof(path), "%s/%s", pe->name, filename); 136 if ((f = fopen(path, "r")) != NULL) { 137 set_input(i, f, path); 138 return i; 139 } 140 } 141 return NULL; 142} 143 144struct input_file * 145fopen_trypath(struct input_file *i, const char *filename) 146{ 147 FILE *f; 148 149 f = fopen(filename, "r"); 150 if (f != NULL) { 151 set_input(i, f, filename); 152 return i; 153 } 154 if (filename[0] == '/') 155 return NULL; 156 157 ensure_m4path(); 158 159 return dopath(i, filename); 160} 161 162void 163doindir(const char *argv[], int argc) 164{ 165 ndptr p; 166 167 p = lookup(argv[2]); 168 if (p == NULL) 169 errx(1, "undefined macro %s", argv[2]); 170 argv[1] = p->defn; 171 eval(argv+1, argc-1, p->type); 172} 173 174void 175dobuiltin(const char *argv[], int argc) 176{ 177 int n; 178 argv[1] = NULL; 179 n = builtin_type(argv[2]); 180 if (n != -1) 181 eval(argv+1, argc-1, n); 182 else 183 errx(1, "unknown builtin %s", argv[2]); 184} 185 186 187/* We need some temporary buffer space, as pb pushes BACK and substitution 188 * proceeds forward... */ 189static char *buffer; 190static size_t bufsize = 0; 191static size_t current = 0; 192 193static void addchars(const char *, size_t); 194static void addchar(int); 195static char *twiddle(const char *); 196static char *getstring(void); 197static void exit_regerror(int, regex_t *); 198static void do_subst(const char *, regex_t *, const char *, regmatch_t *); 199static void do_regexpindex(const char *, regex_t *, regmatch_t *); 200static void do_regexp(const char *, regex_t *, const char *, regmatch_t *); 201static void add_sub(size_t, const char *, regex_t *, regmatch_t *); 202static void add_replace(const char *, regex_t *, const char *, regmatch_t *); 203#define addconstantstring(s) addchars((s), sizeof(s)-1) 204 205static void 206addchars(const char *c, size_t n) 207{ 208 if (n == 0) 209 return; 210 while (current + n > bufsize) { 211 if (bufsize == 0) 212 bufsize = 1024; 213 else 214 bufsize *= 2; 215 buffer = realloc(buffer, bufsize); 216 if (buffer == NULL) 217 errx(1, "out of memory"); 218 } 219 memcpy(buffer+current, c, n); 220 current += n; 221} 222 223static void 224addchar(int c) 225{ 226 if (current +1 > bufsize) { 227 if (bufsize == 0) 228 bufsize = 1024; 229 else 230 bufsize *= 2; 231 buffer = realloc(buffer, bufsize); 232 if (buffer == NULL) 233 errx(1, "out of memory"); 234 } 235 buffer[current++] = c; 236} 237 238static char * 239getstring(void) 240{ 241 addchar('\0'); 242 current = 0; 243 return buffer; 244} 245 246 247static void 248exit_regerror(int er, regex_t *re) 249{ 250 size_t errlen; 251 char *errbuf; 252 253 errlen = regerror(er, re, NULL, 0); 254 errbuf = xalloc(errlen); 255 regerror(er, re, errbuf, errlen); 256 errx(1, "regular expression error: %s", errbuf); 257} 258 259static void 260add_sub(size_t n, const char *string, regex_t *re, regmatch_t *pm) 261{ 262 if (n > re->re_nsub) 263 warnx("No subexpression %zu", n); 264 /* Subexpressions that did not match are 265 * not an error. */ 266 else if (pm[n].rm_so != -1 && 267 pm[n].rm_eo != -1) { 268 addchars(string + pm[n].rm_so, 269 pm[n].rm_eo - pm[n].rm_so); 270 } 271} 272 273/* Add replacement string to the output buffer, recognizing special 274 * constructs and replacing them with substrings of the original string. 275 */ 276static void 277add_replace(const char *string, regex_t *re, const char *replace, regmatch_t *pm) 278{ 279 const char *p; 280 281 for (p = replace; *p != '\0'; p++) { 282 if (*p == '&' && !mimic_gnu) { 283 add_sub(0, string, re, pm); 284 continue; 285 } 286 if (*p == '\\') { 287 if (p[1] == '\\') { 288 addchar(p[1]); 289 p++; 290 continue; 291 } 292 if (p[1] == '&') { 293 if (mimic_gnu) 294 add_sub(0, string, re, pm); 295 else 296 addchar(p[1]); 297 p++; 298 continue; 299 } 300 if (isdigit(p[1])) { 301 add_sub(*(++p) - '0', string, re, pm); 302 continue; 303 } 304 } 305 addchar(*p); 306 } 307} 308 309static void 310do_subst(const char *string, regex_t *re, const char *replace, regmatch_t *pm) 311{ 312 int error; 313 int flags = 0; 314 const char *last_match = NULL; 315 316 while ((error = regexec(re, string, re->re_nsub+1, pm, flags)) == 0) { 317 if (pm[0].rm_eo != 0) { 318 if (string[pm[0].rm_eo-1] == '\n') 319 flags = 0; 320 else 321 flags = REG_NOTBOL; 322 } 323 324 /* NULL length matches are special... We use the `vi-mode' 325 * rule: don't allow a NULL-match at the last match 326 * position. 327 */ 328 if (pm[0].rm_so == pm[0].rm_eo && 329 string + pm[0].rm_so == last_match) { 330 if (*string == '\0') 331 return; 332 addchar(*string); 333 if (*string++ == '\n') 334 flags = 0; 335 else 336 flags = REG_NOTBOL; 337 continue; 338 } 339 last_match = string + pm[0].rm_so; 340 addchars(string, pm[0].rm_so); 341 add_replace(string, re, replace, pm); 342 string += pm[0].rm_eo; 343 } 344 if (error != REG_NOMATCH) 345 exit_regerror(error, re); 346 pbstr(string); 347} 348 349static void 350do_regexp(const char *string, regex_t *re, const char *replace, regmatch_t *pm) 351{ 352 int error; 353 354 switch(error = regexec(re, string, re->re_nsub+1, pm, 0)) { 355 case 0: 356 add_replace(string, re, replace, pm); 357 pbstr(getstring()); 358 break; 359 case REG_NOMATCH: 360 break; 361 default: 362 exit_regerror(error, re); 363 } 364} 365 366static void 367do_regexpindex(const char *string, regex_t *re, regmatch_t *pm) 368{ 369 int error; 370 371 switch(error = regexec(re, string, re->re_nsub+1, pm, 0)) { 372 case 0: 373 pbunsigned(pm[0].rm_so); 374 break; 375 case REG_NOMATCH: 376 pbnum(-1); 377 break; 378 default: 379 exit_regerror(error, re); 380 } 381} 382 383/* In Gnu m4 mode, parentheses for backmatch don't work like POSIX 1003.2 384 * says. So we twiddle with the regexp before passing it to regcomp. 385 */ 386static char * 387twiddle(const char *p) 388{ 389 /* This could use strcspn for speed... */ 390 while (*p != '\0') { 391 if (*p == '\\') { 392 switch(p[1]) { 393 case '(': 394 case ')': 395 case '|': 396 addchar(p[1]); 397 break; 398 case 'w': 399 addconstantstring("[_a-zA-Z0-9]"); 400 break; 401 case 'W': 402 addconstantstring("[^_a-zA-Z0-9]"); 403 break; 404 case '<': 405 addconstantstring("[[:<:]]"); 406 break; 407 case '>': 408 addconstantstring("[[:>:]]"); 409 break; 410 default: 411 addchars(p, 2); 412 break; 413 } 414 p+=2; 415 continue; 416 } 417 if (*p == '(' || *p == ')' || *p == '|') 418 addchar('\\'); 419 420 addchar(*p); 421 p++; 422 } 423 return getstring(); 424} 425 426/* patsubst(string, regexp, opt replacement) */ 427/* argv[2]: string 428 * argv[3]: regexp 429 * argv[4]: opt rep 430 */ 431void 432dopatsubst(const char *argv[], int argc) 433{ 434 int error; 435 regex_t re; 436 regmatch_t *pmatch; 437 438 if (argc <= 3) { 439 warnx("Too few arguments to patsubst"); 440 return; 441 } 442 error = regcomp(&re, mimic_gnu ? twiddle(argv[3]) : argv[3], 443 REG_NEWLINE | REG_EXTENDED); 444 if (error != 0) 445 exit_regerror(error, &re); 446 447 pmatch = xalloc(sizeof(regmatch_t) * (re.re_nsub+1)); 448 do_subst(argv[2], &re, 449 argc != 4 && argv[4] != NULL ? argv[4] : "", pmatch); 450 pbstr(getstring()); 451 free(pmatch); 452 regfree(&re); 453} 454 455void 456doregexp(const char *argv[], int argc) 457{ 458 int error; 459 regex_t re; 460 regmatch_t *pmatch; 461 462 if (argc <= 3) { 463 warnx("Too few arguments to regexp"); 464 return; 465 } 466 error = regcomp(&re, mimic_gnu ? twiddle(argv[3]) : argv[3], 467 REG_EXTENDED); 468 if (error != 0) 469 exit_regerror(error, &re); 470 471 pmatch = xalloc(sizeof(regmatch_t) * (re.re_nsub+1)); 472 if (argv[4] == NULL || argc == 4) 473 do_regexpindex(argv[2], &re, pmatch); 474 else 475 do_regexp(argv[2], &re, argv[4], pmatch); 476 free(pmatch); 477 regfree(&re); 478} 479 480void 481doesyscmd(const char *cmd) 482{ 483 int p[2]; 484 pid_t pid, cpid; 485 int cc; 486 int status; 487 488 /* Follow gnu m4 documentation: first flush buffers. */ 489 fflush(NULL); 490 491 /* Just set up standard output, share stderr and stdin with m4 */ 492 if (pipe(p) == -1) 493 err(1, "bad pipe"); 494 switch(cpid = fork()) { 495 case -1: 496 err(1, "bad fork"); 497 /* NOTREACHED */ 498 case 0: 499 (void) close(p[0]); 500 (void) dup2(p[1], 1); 501 (void) close(p[1]); 502 execl(_PATH_BSHELL, "sh", "-c", cmd, (char *)NULL); 503 exit(1); 504 default: 505 /* Read result in two stages, since m4's buffer is 506 * pushback-only. */ 507 (void) close(p[1]); 508 do { 509 char result[BUFSIZE]; 510 cc = read(p[0], result, sizeof result); 511 if (cc > 0) 512 addchars(result, cc); 513 } while (cc > 0 || (cc == -1 && errno == EINTR)); 514 515 (void) close(p[0]); 516 while ((pid = wait(&status)) != cpid && pid >= 0) 517 continue; 518 pbstr(getstring()); 519 } 520} 521