1 /* 2 * Copyright (c) 2002 - 2014 Tony Finch <dot@dotat.at> 3 * 4 * Redistribution and use in source and binary forms, with or without 5 * modification, are permitted provided that the following conditions 6 * are met: 7 * 1. Redistributions of source code must retain the above copyright 8 * notice, this list of conditions and the following disclaimer. 9 * 2. Redistributions in binary form must reproduce the above copyright 10 * notice, this list of conditions and the following disclaimer in the 11 * documentation and/or other materials provided with the distribution. 12 * 13 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 14 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 15 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 16 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 17 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 18 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 19 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 20 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 21 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 22 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 23 * SUCH DAMAGE. 24 */ 25 26 /* 27 * unifdef - remove ifdef'ed lines 28 * 29 * This code was derived from software contributed to Berkeley by Dave Yost. 30 * It was rewritten to support ANSI C by Tony Finch. The original version 31 * of unifdef carried the 4-clause BSD copyright licence. None of its code 32 * remains in this version (though some of the names remain) so it now 33 * carries a more liberal licence. 34 * 35 * Wishlist: 36 * provide an option which will append the name of the 37 * appropriate symbol after #else's and #endif's 38 * provide an option which will check symbols after 39 * #else's and #endif's to see that they match their 40 * corresponding #ifdef or #ifndef 41 * 42 * These require better buffer handling, which would also make 43 * it possible to handle all "dodgy" directives correctly. 44 */ 45 46 #include "unifdef.h" 47 48 static const char copyright[] = 49 #include "version.h" 50 "@(#) $Author: Tony Finch (dot@dotat.at) $\n" 51 "@(#) $URL: http://dotat.at/prog/unifdef $\n" 52 ; 53 54 /* types of input lines: */ 55 typedef enum { 56 LT_TRUEI, /* a true #if with ignore flag */ 57 LT_FALSEI, /* a false #if with ignore flag */ 58 LT_IF, /* an unknown #if */ 59 LT_TRUE, /* a true #if */ 60 LT_FALSE, /* a false #if */ 61 LT_ELIF, /* an unknown #elif */ 62 LT_ELTRUE, /* a true #elif */ 63 LT_ELFALSE, /* a false #elif */ 64 LT_ELSE, /* #else */ 65 LT_ENDIF, /* #endif */ 66 LT_DODGY, /* flag: directive is not on one line */ 67 LT_DODGY_LAST = LT_DODGY + LT_ENDIF, 68 LT_PLAIN, /* ordinary line */ 69 LT_EOF, /* end of file */ 70 LT_ERROR, /* unevaluable #if */ 71 LT_COUNT 72 } Linetype; 73 74 static char const * const linetype_name[] = { 75 "TRUEI", "FALSEI", "IF", "TRUE", "FALSE", 76 "ELIF", "ELTRUE", "ELFALSE", "ELSE", "ENDIF", 77 "DODGY TRUEI", "DODGY FALSEI", 78 "DODGY IF", "DODGY TRUE", "DODGY FALSE", 79 "DODGY ELIF", "DODGY ELTRUE", "DODGY ELFALSE", 80 "DODGY ELSE", "DODGY ENDIF", 81 "PLAIN", "EOF", "ERROR" 82 }; 83 84 #define linetype_if2elif(lt) ((Linetype)(lt - LT_IF + LT_ELIF)) 85 #define linetype_2dodgy(lt) ((Linetype)(lt + LT_DODGY)) 86 87 /* state of #if processing */ 88 typedef enum { 89 IS_OUTSIDE, 90 IS_FALSE_PREFIX, /* false #if followed by false #elifs */ 91 IS_TRUE_PREFIX, /* first non-false #(el)if is true */ 92 IS_PASS_MIDDLE, /* first non-false #(el)if is unknown */ 93 IS_FALSE_MIDDLE, /* a false #elif after a pass state */ 94 IS_TRUE_MIDDLE, /* a true #elif after a pass state */ 95 IS_PASS_ELSE, /* an else after a pass state */ 96 IS_FALSE_ELSE, /* an else after a true state */ 97 IS_TRUE_ELSE, /* an else after only false states */ 98 IS_FALSE_TRAILER, /* #elifs after a true are false */ 99 IS_COUNT 100 } Ifstate; 101 102 static char const * const ifstate_name[] = { 103 "OUTSIDE", "FALSE_PREFIX", "TRUE_PREFIX", 104 "PASS_MIDDLE", "FALSE_MIDDLE", "TRUE_MIDDLE", 105 "PASS_ELSE", "FALSE_ELSE", "TRUE_ELSE", 106 "FALSE_TRAILER" 107 }; 108 109 /* state of comment parser */ 110 typedef enum { 111 NO_COMMENT = false, /* outside a comment */ 112 C_COMMENT, /* in a comment like this one */ 113 CXX_COMMENT, /* between // and end of line */ 114 STARTING_COMMENT, /* just after slash-backslash-newline */ 115 FINISHING_COMMENT, /* star-backslash-newline in a C comment */ 116 CHAR_LITERAL, /* inside '' */ 117 STRING_LITERAL /* inside "" */ 118 } Comment_state; 119 120 static char const * const comment_name[] = { 121 "NO", "C", "CXX", "STARTING", "FINISHING", "CHAR", "STRING" 122 }; 123 124 /* state of preprocessor line parser */ 125 typedef enum { 126 LS_START, /* only space and comments on this line */ 127 LS_HASH, /* only space, comments, and a hash */ 128 LS_DIRTY /* this line can't be a preprocessor line */ 129 } Line_state; 130 131 static char const * const linestate_name[] = { 132 "START", "HASH", "DIRTY" 133 }; 134 135 /* 136 * Minimum translation limits from ISO/IEC 9899:1999 5.2.4.1 137 */ 138 #define MAXDEPTH 64 /* maximum #if nesting */ 139 #define MAXLINE 4096 /* maximum length of line */ 140 #define MAXSYMS 16384 /* maximum number of symbols */ 141 142 /* 143 * Sometimes when editing a keyword the replacement text is longer, so 144 * we leave some space at the end of the tline buffer to accommodate this. 145 */ 146 #define EDITSLOP 10 147 148 /* 149 * Globals. 150 */ 151 152 static bool compblank; /* -B: compress blank lines */ 153 static bool lnblank; /* -b: blank deleted lines */ 154 static bool complement; /* -c: do the complement */ 155 static bool debugging; /* -d: debugging reports */ 156 static bool inplace; /* -m: modify in place */ 157 static bool iocccok; /* -e: fewer IOCCC errors */ 158 static bool strictlogic; /* -K: keep ambiguous #ifs */ 159 static bool killconsts; /* -k: eval constant #ifs */ 160 static bool lnnum; /* -n: add #line directives */ 161 static bool symlist; /* -s: output symbol list */ 162 static bool symdepth; /* -S: output symbol depth */ 163 static bool text; /* -t: this is a text file */ 164 165 static const char *symname[MAXSYMS]; /* symbol name */ 166 static const char *value[MAXSYMS]; /* -Dsym=value */ 167 static bool ignore[MAXSYMS]; /* -iDsym or -iUsym */ 168 static int nsyms; /* number of symbols */ 169 170 static FILE *input; /* input file pointer */ 171 static const char *filename; /* input file name */ 172 static int linenum; /* current line number */ 173 static const char *linefile; /* file name for #line */ 174 static FILE *output; /* output file pointer */ 175 static const char *ofilename; /* output file name */ 176 static const char *backext; /* backup extension */ 177 static char *tempname; /* avoid splatting input */ 178 179 static char tline[MAXLINE+EDITSLOP];/* input buffer plus space */ 180 static char *keyword; /* used for editing #elif's */ 181 182 /* 183 * When processing a file, the output's newline style will match the 184 * input's, and unifdef correctly handles CRLF or LF endings whatever 185 * the platform's native style. The stdio streams are opened in binary 186 * mode to accommodate platforms whose native newline style is CRLF. 187 * When the output isn't a processed input file (when it is error / 188 * debug / diagnostic messages) then unifdef uses native line endings. 189 */ 190 191 static const char *newline; /* input file format */ 192 static const char newline_unix[] = "\n"; 193 static const char newline_crlf[] = "\r\n"; 194 195 static Comment_state incomment; /* comment parser state */ 196 static Line_state linestate; /* #if line parser state */ 197 static Ifstate ifstate[MAXDEPTH]; /* #if processor state */ 198 static bool ignoring[MAXDEPTH]; /* ignore comments state */ 199 static int stifline[MAXDEPTH]; /* start of current #if */ 200 static int depth; /* current #if nesting */ 201 static int delcount; /* count of deleted lines */ 202 static unsigned blankcount; /* count of blank lines */ 203 static unsigned blankmax; /* maximum recent blankcount */ 204 static bool constexpr; /* constant #if expression */ 205 static bool zerosyms; /* to format symdepth output */ 206 static bool firstsym; /* ditto */ 207 208 static int exitmode; /* exit status mode */ 209 static int exitstat; /* program exit status */ 210 static bool altered; /* was this file modified? */ 211 212 static void addsym1(bool, bool, char *); 213 static void addsym2(bool, const char *, const char *); 214 static char *astrcat(const char *, const char *); 215 static void cleantemp(void); 216 static void closeio(void); 217 static void debug(const char *, ...) __printflike(1, 2); 218 static void debugsym(const char *, int); 219 static bool defundef(void); 220 static void defundefile(const char *); 221 static void done(void); 222 static void error(const char *); 223 static int findsym(const char **); 224 static void flushline(bool); 225 static void hashline(void); 226 static void help(void); 227 static Linetype ifeval(const char **); 228 static void ignoreoff(void); 229 static void ignoreon(void); 230 static void indirectsym(void); 231 static void keywordedit(const char *); 232 static const char *matchsym(const char *, const char *); 233 static void nest(void); 234 static Linetype parseline(void); 235 static void process(void); 236 static void processinout(const char *, const char *); 237 static const char *skipargs(const char *); 238 static const char *skipcomment(const char *); 239 static const char *skiphash(void); 240 static const char *skipline(const char *); 241 static const char *skipsym(const char *); 242 static void state(Ifstate); 243 static void unnest(void); 244 static void usage(void); 245 static void version(void); 246 static const char *xstrdup(const char *, const char *); 247 248 #define endsym(c) (!isalnum((unsigned char)c) && c != '_') 249 250 /* 251 * The main program. 252 */ 253 int 254 main(int argc, char *argv[]) 255 { 256 int opt; 257 258 while ((opt = getopt(argc, argv, "i:D:U:f:I:M:o:x:bBcdehKklmnsStV")) != -1) 259 switch (opt) { 260 case 'i': /* treat stuff controlled by these symbols as text */ 261 /* 262 * For strict backwards-compatibility the U or D 263 * should be immediately after the -i but it doesn't 264 * matter much if we relax that requirement. 265 */ 266 opt = *optarg++; 267 if (opt == 'D') 268 addsym1(true, true, optarg); 269 else if (opt == 'U') 270 addsym1(true, false, optarg); 271 else 272 usage(); 273 break; 274 case 'D': /* define a symbol */ 275 addsym1(false, true, optarg); 276 break; 277 case 'U': /* undef a symbol */ 278 addsym1(false, false, optarg); 279 break; 280 case 'I': /* no-op for compatibility with cpp */ 281 break; 282 case 'b': /* blank deleted lines instead of omitting them */ 283 case 'l': /* backwards compatibility */ 284 lnblank = true; 285 break; 286 case 'B': /* compress blank lines around removed section */ 287 compblank = true; 288 break; 289 case 'c': /* treat -D as -U and vice versa */ 290 complement = true; 291 break; 292 case 'd': 293 debugging = true; 294 break; 295 case 'e': /* fewer errors from dodgy lines */ 296 iocccok = true; 297 break; 298 case 'f': /* definitions file */ 299 defundefile(optarg); 300 break; 301 case 'h': 302 help(); 303 break; 304 case 'K': /* keep ambiguous #ifs */ 305 strictlogic = true; 306 break; 307 case 'k': /* process constant #ifs */ 308 killconsts = true; 309 break; 310 case 'm': /* modify in place */ 311 inplace = true; 312 break; 313 case 'M': /* modify in place and keep backup */ 314 inplace = true; 315 backext = optarg; 316 break; 317 case 'n': /* add #line directive after deleted lines */ 318 lnnum = true; 319 break; 320 case 'o': /* output to a file */ 321 ofilename = optarg; 322 break; 323 case 's': /* only output list of symbols that control #ifs */ 324 symlist = true; 325 break; 326 case 'S': /* list symbols with their nesting depth */ 327 symlist = symdepth = true; 328 break; 329 case 't': /* don't parse C comments */ 330 text = true; 331 break; 332 case 'V': 333 version(); 334 break; 335 case 'x': 336 exitmode = atoi(optarg); 337 if(exitmode < 0 || exitmode > 2) 338 usage(); 339 break; 340 default: 341 usage(); 342 } 343 argc -= optind; 344 argv += optind; 345 if (compblank && lnblank) 346 errx(2, "-B and -b are mutually exclusive"); 347 if (symlist && (ofilename != NULL || inplace || argc > 1)) 348 errx(2, "-s only works with one input file"); 349 if (argc > 1 && ofilename != NULL) 350 errx(2, "-o cannot be used with multiple input files"); 351 if (argc > 1 && !inplace) 352 errx(2, "multiple input files require -m or -M"); 353 if (argc == 0) 354 argc = 1; 355 if (argc == 1 && !inplace && ofilename == NULL) 356 ofilename = "-"; 357 indirectsym(); 358 359 atexit(cleantemp); 360 if (ofilename != NULL) 361 processinout(*argv, ofilename); 362 else while (argc-- > 0) { 363 processinout(*argv, *argv); 364 argv++; 365 } 366 switch(exitmode) { 367 case(0): exit(exitstat); 368 case(1): exit(!exitstat); 369 case(2): exit(0); 370 default: abort(); /* bug */ 371 } 372 } 373 374 /* 375 * File logistics. 376 */ 377 static void 378 processinout(const char *ifn, const char *ofn) 379 { 380 struct stat st; 381 382 if (ifn == NULL || strcmp(ifn, "-") == 0) { 383 filename = "[stdin]"; 384 linefile = NULL; 385 input = fbinmode(stdin); 386 } else { 387 filename = ifn; 388 linefile = ifn; 389 input = fopen(ifn, "rb"); 390 if (input == NULL) 391 err(2, "can't open %s", ifn); 392 } 393 if (strcmp(ofn, "-") == 0) { 394 output = fbinmode(stdout); 395 process(); 396 return; 397 } 398 if (stat(ofn, &st) < 0) { 399 output = fopen(ofn, "wb"); 400 if (output == NULL) 401 err(2, "can't create %s", ofn); 402 process(); 403 return; 404 } 405 406 tempname = astrcat(ofn, ".XXXXXX"); 407 output = mktempmode(tempname, st.st_mode); 408 if (output == NULL) 409 err(2, "can't create %s", tempname); 410 411 process(); 412 413 if (backext != NULL) { 414 char *backname = astrcat(ofn, backext); 415 if (rename(ofn, backname) < 0) 416 err(2, "can't rename \"%s\" to \"%s\"", ofn, backname); 417 free(backname); 418 } 419 /* leave file unmodified if unifdef made no changes */ 420 if (!altered && backext == NULL) { 421 if (remove(tempname) < 0) 422 warn("can't remove \"%s\"", tempname); 423 } else if (replace(tempname, ofn) < 0) 424 err(2, "can't rename \"%s\" to \"%s\"", tempname, ofn); 425 free(tempname); 426 tempname = NULL; 427 } 428 429 /* 430 * For cleaning up if there is an error. 431 */ 432 static void 433 cleantemp(void) 434 { 435 if (tempname != NULL) 436 remove(tempname); 437 } 438 439 /* 440 * Self-identification functions. 441 */ 442 443 static void 444 version(void) 445 { 446 const char *c = copyright; 447 for (;;) { 448 while (*++c != '$') 449 if (*c == '\0') 450 exit(0); 451 while (*++c != '$') 452 putc(*c, stderr); 453 putc('\n', stderr); 454 } 455 } 456 457 static void 458 synopsis(FILE *fp) 459 { 460 fprintf(fp, 461 "usage: unifdef [-bBcdehKkmnsStV] [-x{012}] [-Mext] [-opath] \\\n" 462 " [-[i]Dsym[=val]] [-[i]Usym] [-fpath] ... [file] ...\n"); 463 } 464 465 static void 466 usage(void) 467 { 468 synopsis(stderr); 469 exit(2); 470 } 471 472 static void 473 help(void) 474 { 475 synopsis(stdout); 476 printf( 477 " -Dsym=val define preprocessor symbol with given value\n" 478 " -Dsym define preprocessor symbol with value 1\n" 479 " -Usym preprocessor symbol is undefined\n" 480 " -iDsym=val \\ ignore C strings and comments\n" 481 " -iDsym ) in sections controlled by these\n" 482 " -iUsym / preprocessor symbols\n" 483 " -fpath file containing #define and #undef directives\n" 484 " -b blank lines instead of deleting them\n" 485 " -B compress blank lines around deleted section\n" 486 " -c complement (invert) keep vs. delete\n" 487 " -d debugging mode\n" 488 " -e ignore multiline preprocessor directives\n" 489 " -h print help\n" 490 " -Ipath extra include file path (ignored)\n" 491 " -K disable && and || short-circuiting\n" 492 " -k process constant #if expressions\n" 493 " -Mext modify in place and keep backups\n" 494 " -m modify input files in place\n" 495 " -n add #line directives to output\n" 496 " -opath output file name\n" 497 " -S list #if control symbols with nesting\n" 498 " -s list #if control symbols\n" 499 " -t ignore C strings and comments\n" 500 " -V print version\n" 501 " -x{012} exit status mode\n" 502 ); 503 exit(0); 504 } 505 506 /* 507 * A state transition function alters the global #if processing state 508 * in a particular way. The table below is indexed by the current 509 * processing state and the type of the current line. 510 * 511 * Nesting is handled by keeping a stack of states; some transition 512 * functions increase or decrease the depth. They also maintain the 513 * ignore state on a stack. In some complicated cases they have to 514 * alter the preprocessor directive, as follows. 515 * 516 * When we have processed a group that starts off with a known-false 517 * #if/#elif sequence (which has therefore been deleted) followed by a 518 * #elif that we don't understand and therefore must keep, we edit the 519 * latter into a #if to keep the nesting correct. We use memcpy() to 520 * overwrite the 4 byte token "elif" with "if " without a '\0' byte. 521 * 522 * When we find a true #elif in a group, the following block will 523 * always be kept and the rest of the sequence after the next #elif or 524 * #else will be discarded. We edit the #elif into a #else and the 525 * following directive to #endif since this has the desired behaviour. 526 * 527 * "Dodgy" directives are split across multiple lines, the most common 528 * example being a multi-line comment hanging off the right of the 529 * directive. We can handle them correctly only if there is no change 530 * from printing to dropping (or vice versa) caused by that directive. 531 * If the directive is the first of a group we have a choice between 532 * failing with an error, or passing it through unchanged instead of 533 * evaluating it. The latter is not the default to avoid questions from 534 * users about unifdef unexpectedly leaving behind preprocessor directives. 535 */ 536 typedef void state_fn(void); 537 538 /* report an error */ 539 static void Eelif (void) { error("Inappropriate #elif"); } 540 static void Eelse (void) { error("Inappropriate #else"); } 541 static void Eendif(void) { error("Inappropriate #endif"); } 542 static void Eeof (void) { error("Premature EOF"); } 543 static void Eioccc(void) { error("Obfuscated preprocessor control line"); } 544 /* plain line handling */ 545 static void print (void) { flushline(true); } 546 static void drop (void) { flushline(false); } 547 /* output lacks group's start line */ 548 static void Strue (void) { drop(); ignoreoff(); state(IS_TRUE_PREFIX); } 549 static void Sfalse(void) { drop(); ignoreoff(); state(IS_FALSE_PREFIX); } 550 static void Selse (void) { drop(); state(IS_TRUE_ELSE); } 551 /* print/pass this block */ 552 static void Pelif (void) { print(); ignoreoff(); state(IS_PASS_MIDDLE); } 553 static void Pelse (void) { print(); state(IS_PASS_ELSE); } 554 static void Pendif(void) { print(); unnest(); } 555 /* discard this block */ 556 static void Dfalse(void) { drop(); ignoreoff(); state(IS_FALSE_TRAILER); } 557 static void Delif (void) { drop(); ignoreoff(); state(IS_FALSE_MIDDLE); } 558 static void Delse (void) { drop(); state(IS_FALSE_ELSE); } 559 static void Dendif(void) { drop(); unnest(); } 560 /* first line of group */ 561 static void Fdrop (void) { nest(); Dfalse(); } 562 static void Fpass (void) { nest(); Pelif(); } 563 static void Ftrue (void) { nest(); Strue(); } 564 static void Ffalse(void) { nest(); Sfalse(); } 565 /* variable pedantry for obfuscated lines */ 566 static void Oiffy (void) { if (!iocccok) Eioccc(); Fpass(); ignoreon(); } 567 static void Oif (void) { if (!iocccok) Eioccc(); Fpass(); } 568 static void Oelif (void) { if (!iocccok) Eioccc(); Pelif(); } 569 /* ignore comments in this block */ 570 static void Idrop (void) { Fdrop(); ignoreon(); } 571 static void Itrue (void) { Ftrue(); ignoreon(); } 572 static void Ifalse(void) { Ffalse(); ignoreon(); } 573 /* modify this line */ 574 static void Mpass (void) { memcpy(keyword, "if ", 4); Pelif(); } 575 static void Mtrue (void) { keywordedit("else"); state(IS_TRUE_MIDDLE); } 576 static void Melif (void) { keywordedit("endif"); state(IS_FALSE_TRAILER); } 577 static void Melse (void) { keywordedit("endif"); state(IS_FALSE_ELSE); } 578 579 static state_fn * const trans_table[IS_COUNT][LT_COUNT] = { 580 /* IS_OUTSIDE */ 581 { Itrue, Ifalse,Fpass, Ftrue, Ffalse,Eelif, Eelif, Eelif, Eelse, Eendif, 582 Oiffy, Oiffy, Fpass, Oif, Oif, Eelif, Eelif, Eelif, Eelse, Eendif, 583 print, done, abort }, 584 /* IS_FALSE_PREFIX */ 585 { Idrop, Idrop, Fdrop, Fdrop, Fdrop, Mpass, Strue, Sfalse,Selse, Dendif, 586 Idrop, Idrop, Fdrop, Fdrop, Fdrop, Mpass, Eioccc,Eioccc,Eioccc,Eioccc, 587 drop, Eeof, abort }, 588 /* IS_TRUE_PREFIX */ 589 { Itrue, Ifalse,Fpass, Ftrue, Ffalse,Dfalse,Dfalse,Dfalse,Delse, Dendif, 590 Oiffy, Oiffy, Fpass, Oif, Oif, Eioccc,Eioccc,Eioccc,Eioccc,Eioccc, 591 print, Eeof, abort }, 592 /* IS_PASS_MIDDLE */ 593 { Itrue, Ifalse,Fpass, Ftrue, Ffalse,Pelif, Mtrue, Delif, Pelse, Pendif, 594 Oiffy, Oiffy, Fpass, Oif, Oif, Pelif, Oelif, Oelif, Pelse, Pendif, 595 print, Eeof, abort }, 596 /* IS_FALSE_MIDDLE */ 597 { Idrop, Idrop, Fdrop, Fdrop, Fdrop, Pelif, Mtrue, Delif, Pelse, Pendif, 598 Idrop, Idrop, Fdrop, Fdrop, Fdrop, Eioccc,Eioccc,Eioccc,Eioccc,Eioccc, 599 drop, Eeof, abort }, 600 /* IS_TRUE_MIDDLE */ 601 { Itrue, Ifalse,Fpass, Ftrue, Ffalse,Melif, Melif, Melif, Melse, Pendif, 602 Oiffy, Oiffy, Fpass, Oif, Oif, Eioccc,Eioccc,Eioccc,Eioccc,Pendif, 603 print, Eeof, abort }, 604 /* IS_PASS_ELSE */ 605 { Itrue, Ifalse,Fpass, Ftrue, Ffalse,Eelif, Eelif, Eelif, Eelse, Pendif, 606 Oiffy, Oiffy, Fpass, Oif, Oif, Eelif, Eelif, Eelif, Eelse, Pendif, 607 print, Eeof, abort }, 608 /* IS_FALSE_ELSE */ 609 { Idrop, Idrop, Fdrop, Fdrop, Fdrop, Eelif, Eelif, Eelif, Eelse, Dendif, 610 Idrop, Idrop, Fdrop, Fdrop, Fdrop, Eelif, Eelif, Eelif, Eelse, Eioccc, 611 drop, Eeof, abort }, 612 /* IS_TRUE_ELSE */ 613 { Itrue, Ifalse,Fpass, Ftrue, Ffalse,Eelif, Eelif, Eelif, Eelse, Dendif, 614 Oiffy, Oiffy, Fpass, Oif, Oif, Eelif, Eelif, Eelif, Eelse, Eioccc, 615 print, Eeof, abort }, 616 /* IS_FALSE_TRAILER */ 617 { Idrop, Idrop, Fdrop, Fdrop, Fdrop, Dfalse,Dfalse,Dfalse,Delse, Dendif, 618 Idrop, Idrop, Fdrop, Fdrop, Fdrop, Dfalse,Dfalse,Dfalse,Delse, Eioccc, 619 drop, Eeof, abort } 620 /*TRUEI FALSEI IF TRUE FALSE ELIF ELTRUE ELFALSE ELSE ENDIF 621 TRUEI FALSEI IF TRUE FALSE ELIF ELTRUE ELFALSE ELSE ENDIF (DODGY) 622 PLAIN EOF ERROR */ 623 }; 624 625 /* 626 * State machine utility functions 627 */ 628 static void 629 ignoreoff(void) 630 { 631 if (depth == 0) 632 abort(); /* bug */ 633 ignoring[depth] = ignoring[depth-1]; 634 } 635 static void 636 ignoreon(void) 637 { 638 ignoring[depth] = true; 639 } 640 static void 641 keywordedit(const char *replacement) 642 { 643 snprintf(keyword, tline + sizeof(tline) - keyword, 644 "%s%s", replacement, newline); 645 altered = true; 646 print(); 647 } 648 static void 649 nest(void) 650 { 651 if (depth > MAXDEPTH-1) 652 abort(); /* bug */ 653 if (depth == MAXDEPTH-1) 654 error("Too many levels of nesting"); 655 depth += 1; 656 stifline[depth] = linenum; 657 } 658 static void 659 unnest(void) 660 { 661 if (depth == 0) 662 abort(); /* bug */ 663 depth -= 1; 664 } 665 static void 666 state(Ifstate is) 667 { 668 ifstate[depth] = is; 669 } 670 671 /* 672 * The last state transition function. When this is called, 673 * lineval == LT_EOF, so the process() loop will terminate. 674 */ 675 static void 676 done(void) 677 { 678 if (incomment) 679 error("EOF in comment"); 680 closeio(); 681 } 682 683 /* 684 * Write a line to the output or not, according to command line options. 685 * If writing fails, closeio() will print the error and exit. 686 */ 687 static void 688 flushline(bool keep) 689 { 690 if (symlist) 691 return; 692 if (keep ^ complement) { 693 bool blankline = tline[strspn(tline, " \t\r\n")] == '\0'; 694 if (blankline && compblank && blankcount != blankmax) { 695 delcount += 1; 696 blankcount += 1; 697 } else { 698 if (lnnum && delcount > 0) 699 hashline(); 700 if (fputs(tline, output) == EOF) 701 closeio(); 702 delcount = 0; 703 blankmax = blankcount = blankline ? blankcount + 1 : 0; 704 } 705 } else { 706 if (lnblank && fputs(newline, output) == EOF) 707 closeio(); 708 altered = true; 709 delcount += 1; 710 blankcount = 0; 711 } 712 if (debugging && fflush(output) == EOF) 713 closeio(); 714 } 715 716 /* 717 * Format of #line directives depends on whether we know the input filename. 718 */ 719 static void 720 hashline(void) 721 { 722 int e; 723 724 if (linefile == NULL) 725 e = fprintf(output, "#line %d%s", linenum, newline); 726 else 727 e = fprintf(output, "#line %d \"%s\"%s", 728 linenum, linefile, newline); 729 if (e < 0) 730 closeio(); 731 } 732 733 /* 734 * Flush the output and handle errors. 735 */ 736 static void 737 closeio(void) 738 { 739 /* Tidy up after findsym(). */ 740 if (symdepth && !zerosyms) 741 printf("\n"); 742 if (output != NULL && (ferror(output) || fclose(output) == EOF)) 743 err(2, "%s: can't write to output", filename); 744 fclose(input); 745 } 746 747 /* 748 * The driver for the state machine. 749 */ 750 static void 751 process(void) 752 { 753 Linetype lineval = LT_PLAIN; 754 /* When compressing blank lines, act as if the file 755 is preceded by a large number of blank lines. */ 756 blankmax = blankcount = 1000; 757 zerosyms = true; 758 newline = NULL; 759 linenum = 0; 760 altered = false; 761 while (lineval != LT_EOF) { 762 lineval = parseline(); 763 trans_table[ifstate[depth]][lineval](); 764 debug("process line %d %s -> %s depth %d", 765 linenum, linetype_name[lineval], 766 ifstate_name[ifstate[depth]], depth); 767 } 768 exitstat |= altered; 769 } 770 771 /* 772 * Parse a line and determine its type. We keep the preprocessor line 773 * parser state between calls in the global variable linestate, with 774 * help from skipcomment(). 775 */ 776 static Linetype 777 parseline(void) 778 { 779 const char *cp; 780 int cursym; 781 Linetype retval; 782 Comment_state wascomment; 783 784 wascomment = incomment; 785 cp = skiphash(); 786 if (cp == NULL) 787 return (LT_EOF); 788 if (newline == NULL) { 789 if (strrchr(tline, '\n') == strrchr(tline, '\r') + 1) 790 newline = newline_crlf; 791 else 792 newline = newline_unix; 793 } 794 if (*cp == '\0') { 795 retval = LT_PLAIN; 796 goto done; 797 } 798 keyword = tline + (cp - tline); 799 if ((cp = matchsym("ifdef", keyword)) != NULL || 800 (cp = matchsym("ifndef", keyword)) != NULL) { 801 cp = skipcomment(cp); 802 if ((cursym = findsym(&cp)) < 0) 803 retval = LT_IF; 804 else { 805 retval = (keyword[2] == 'n') 806 ? LT_FALSE : LT_TRUE; 807 if (value[cursym] == NULL) 808 retval = (retval == LT_TRUE) 809 ? LT_FALSE : LT_TRUE; 810 if (ignore[cursym]) 811 retval = (retval == LT_TRUE) 812 ? LT_TRUEI : LT_FALSEI; 813 } 814 } else if ((cp = matchsym("if", keyword)) != NULL) 815 retval = ifeval(&cp); 816 else if ((cp = matchsym("elif", keyword)) != NULL) 817 retval = linetype_if2elif(ifeval(&cp)); 818 else if ((cp = matchsym("else", keyword)) != NULL) 819 retval = LT_ELSE; 820 else if ((cp = matchsym("endif", keyword)) != NULL) 821 retval = LT_ENDIF; 822 else { 823 cp = skipsym(keyword); 824 /* no way can we deal with a continuation inside a keyword */ 825 if (strncmp(cp, "\\\r\n", 3) == 0 || 826 strncmp(cp, "\\\n", 2) == 0) 827 Eioccc(); 828 cp = skipline(cp); 829 retval = LT_PLAIN; 830 goto done; 831 } 832 cp = skipcomment(cp); 833 if (*cp != '\0') { 834 cp = skipline(cp); 835 if (retval == LT_TRUE || retval == LT_FALSE || 836 retval == LT_TRUEI || retval == LT_FALSEI) 837 retval = LT_IF; 838 if (retval == LT_ELTRUE || retval == LT_ELFALSE) 839 retval = LT_ELIF; 840 } 841 /* the following can happen if the last line of the file lacks a 842 newline or if there is too much whitespace in a directive */ 843 if (linestate == LS_HASH) { 844 long len = cp - tline; 845 if (fgets(tline + len, MAXLINE - len, input) == NULL) { 846 if (ferror(input)) 847 err(2, "can't read %s", filename); 848 /* append the missing newline at eof */ 849 strcpy(tline + len, newline); 850 cp += strlen(newline); 851 linestate = LS_START; 852 } else { 853 linestate = LS_DIRTY; 854 } 855 } 856 if (retval != LT_PLAIN && (wascomment || linestate != LS_START)) { 857 retval = linetype_2dodgy(retval); 858 linestate = LS_DIRTY; 859 } 860 done: 861 debug("parser line %d state %s comment %s line", linenum, 862 comment_name[incomment], linestate_name[linestate]); 863 return (retval); 864 } 865 866 /* 867 * These are the binary operators that are supported by the expression 868 * evaluator. 869 */ 870 static Linetype op_strict(long *p, long v, Linetype at, Linetype bt) { 871 if(at == LT_IF || bt == LT_IF) return (LT_IF); 872 return (*p = v, v ? LT_TRUE : LT_FALSE); 873 } 874 static Linetype op_lt(long *p, Linetype at, long a, Linetype bt, long b) { 875 return op_strict(p, a < b, at, bt); 876 } 877 static Linetype op_gt(long *p, Linetype at, long a, Linetype bt, long b) { 878 return op_strict(p, a > b, at, bt); 879 } 880 static Linetype op_le(long *p, Linetype at, long a, Linetype bt, long b) { 881 return op_strict(p, a <= b, at, bt); 882 } 883 static Linetype op_ge(long *p, Linetype at, long a, Linetype bt, long b) { 884 return op_strict(p, a >= b, at, bt); 885 } 886 static Linetype op_eq(long *p, Linetype at, long a, Linetype bt, long b) { 887 return op_strict(p, a == b, at, bt); 888 } 889 static Linetype op_ne(long *p, Linetype at, long a, Linetype bt, long b) { 890 return op_strict(p, a != b, at, bt); 891 } 892 static Linetype op_or(long *p, Linetype at, long a, Linetype bt, long b) { 893 if (!strictlogic && (at == LT_TRUE || bt == LT_TRUE)) 894 return (*p = 1, LT_TRUE); 895 return op_strict(p, a || b, at, bt); 896 } 897 static Linetype op_and(long *p, Linetype at, long a, Linetype bt, long b) { 898 if (!strictlogic && (at == LT_FALSE || bt == LT_FALSE)) 899 return (*p = 0, LT_FALSE); 900 return op_strict(p, a && b, at, bt); 901 } 902 903 /* 904 * An evaluation function takes three arguments, as follows: (1) a pointer to 905 * an element of the precedence table which lists the operators at the current 906 * level of precedence; (2) a pointer to an integer which will receive the 907 * value of the expression; and (3) a pointer to a char* that points to the 908 * expression to be evaluated and that is updated to the end of the expression 909 * when evaluation is complete. The function returns LT_FALSE if the value of 910 * the expression is zero, LT_TRUE if it is non-zero, LT_IF if the expression 911 * depends on an unknown symbol, or LT_ERROR if there is a parse failure. 912 */ 913 struct ops; 914 915 typedef Linetype eval_fn(const struct ops *, long *, const char **); 916 917 static eval_fn eval_table, eval_unary; 918 919 /* 920 * The precedence table. Expressions involving binary operators are evaluated 921 * in a table-driven way by eval_table. When it evaluates a subexpression it 922 * calls the inner function with its first argument pointing to the next 923 * element of the table. Innermost expressions have special non-table-driven 924 * handling. 925 */ 926 struct op { 927 const char *str; 928 Linetype (*fn)(long *, Linetype, long, Linetype, long); 929 }; 930 struct ops { 931 eval_fn *inner; 932 struct op op[5]; 933 }; 934 static const struct ops eval_ops[] = { 935 { eval_table, { { "||", op_or } } }, 936 { eval_table, { { "&&", op_and } } }, 937 { eval_table, { { "==", op_eq }, 938 { "!=", op_ne } } }, 939 { eval_unary, { { "<=", op_le }, 940 { ">=", op_ge }, 941 { "<", op_lt }, 942 { ">", op_gt } } } 943 }; 944 945 /* Current operator precedence level */ 946 static long prec(const struct ops *ops) 947 { 948 return (ops - eval_ops); 949 } 950 951 /* 952 * Function for evaluating the innermost parts of expressions, 953 * viz. !expr (expr) number defined(symbol) symbol 954 * We reset the constexpr flag in the last two cases. 955 */ 956 static Linetype 957 eval_unary(const struct ops *ops, long *valp, const char **cpp) 958 { 959 const char *cp; 960 char *ep; 961 int sym; 962 bool defparen; 963 Linetype lt; 964 965 cp = skipcomment(*cpp); 966 if (*cp == '!') { 967 debug("eval%ld !", prec(ops)); 968 cp++; 969 lt = eval_unary(ops, valp, &cp); 970 if (lt == LT_ERROR) 971 return (LT_ERROR); 972 if (lt != LT_IF) { 973 *valp = !*valp; 974 lt = *valp ? LT_TRUE : LT_FALSE; 975 } 976 } else if (*cp == '(') { 977 cp++; 978 debug("eval%ld (", prec(ops)); 979 lt = eval_table(eval_ops, valp, &cp); 980 if (lt == LT_ERROR) 981 return (LT_ERROR); 982 cp = skipcomment(cp); 983 if (*cp++ != ')') 984 return (LT_ERROR); 985 } else if (isdigit((unsigned char)*cp)) { 986 debug("eval%ld number", prec(ops)); 987 *valp = strtol(cp, &ep, 0); 988 if (ep == cp) 989 return (LT_ERROR); 990 lt = *valp ? LT_TRUE : LT_FALSE; 991 cp = ep; 992 } else if (matchsym("defined", cp) != NULL) { 993 cp = skipcomment(cp+7); 994 if (*cp == '(') { 995 cp = skipcomment(cp+1); 996 defparen = true; 997 } else { 998 defparen = false; 999 } 1000 sym = findsym(&cp); 1001 cp = skipcomment(cp); 1002 if (defparen && *cp++ != ')') { 1003 debug("eval%ld defined missing ')'", prec(ops)); 1004 return (LT_ERROR); 1005 } 1006 if (sym < 0) { 1007 debug("eval%ld defined unknown", prec(ops)); 1008 lt = LT_IF; 1009 } else { 1010 debug("eval%ld defined %s", prec(ops), symname[sym]); 1011 *valp = (value[sym] != NULL); 1012 lt = *valp ? LT_TRUE : LT_FALSE; 1013 } 1014 constexpr = false; 1015 } else if (!endsym(*cp)) { 1016 debug("eval%ld symbol", prec(ops)); 1017 sym = findsym(&cp); 1018 if (sym < 0) { 1019 lt = LT_IF; 1020 cp = skipargs(cp); 1021 } else if (value[sym] == NULL) { 1022 *valp = 0; 1023 lt = LT_FALSE; 1024 } else { 1025 *valp = strtol(value[sym], &ep, 0); 1026 if (*ep != '\0' || ep == value[sym]) 1027 return (LT_ERROR); 1028 lt = *valp ? LT_TRUE : LT_FALSE; 1029 cp = skipargs(cp); 1030 } 1031 constexpr = false; 1032 } else { 1033 debug("eval%ld bad expr", prec(ops)); 1034 return (LT_ERROR); 1035 } 1036 1037 *cpp = cp; 1038 debug("eval%ld = %ld", prec(ops), *valp); 1039 return (lt); 1040 } 1041 1042 /* 1043 * Table-driven evaluation of binary operators. 1044 */ 1045 static Linetype 1046 eval_table(const struct ops *ops, long *valp, const char **cpp) 1047 { 1048 const struct op *op; 1049 const char *cp; 1050 long val; 1051 Linetype lt, rt; 1052 1053 debug("eval%ld", prec(ops)); 1054 cp = *cpp; 1055 lt = ops->inner(ops+1, valp, &cp); 1056 if (lt == LT_ERROR) 1057 return (LT_ERROR); 1058 for (;;) { 1059 cp = skipcomment(cp); 1060 for (op = ops->op; op->str != NULL; op++) 1061 if (strncmp(cp, op->str, strlen(op->str)) == 0) 1062 break; 1063 if (op->str == NULL) 1064 break; 1065 cp += strlen(op->str); 1066 debug("eval%ld %s", prec(ops), op->str); 1067 rt = ops->inner(ops+1, &val, &cp); 1068 if (rt == LT_ERROR) 1069 return (LT_ERROR); 1070 lt = op->fn(valp, lt, *valp, rt, val); 1071 } 1072 1073 *cpp = cp; 1074 debug("eval%ld = %ld", prec(ops), *valp); 1075 debug("eval%ld lt = %s", prec(ops), linetype_name[lt]); 1076 return (lt); 1077 } 1078 1079 /* 1080 * Evaluate the expression on a #if or #elif line. If we can work out 1081 * the result we return LT_TRUE or LT_FALSE accordingly, otherwise we 1082 * return just a generic LT_IF. 1083 */ 1084 static Linetype 1085 ifeval(const char **cpp) 1086 { 1087 Linetype ret; 1088 long val = 0; 1089 1090 debug("eval %s", *cpp); 1091 constexpr = killconsts ? false : true; 1092 ret = eval_table(eval_ops, &val, cpp); 1093 debug("eval = %ld", val); 1094 return (constexpr ? LT_IF : ret == LT_ERROR ? LT_IF : ret); 1095 } 1096 1097 /* 1098 * Read a line and examine its initial part to determine if it is a 1099 * preprocessor directive. Returns NULL on EOF, or a pointer to a 1100 * preprocessor directive name, or a pointer to the zero byte at the 1101 * end of the line. 1102 */ 1103 static const char * 1104 skiphash(void) 1105 { 1106 const char *cp; 1107 1108 linenum++; 1109 if (fgets(tline, MAXLINE, input) == NULL) { 1110 if (ferror(input)) 1111 err(2, "can't read %s", filename); 1112 else 1113 return (NULL); 1114 } 1115 cp = skipcomment(tline); 1116 if (linestate == LS_START && *cp == '#') { 1117 linestate = LS_HASH; 1118 return (skipcomment(cp + 1)); 1119 } else if (*cp == '\0') { 1120 return (cp); 1121 } else { 1122 return (skipline(cp)); 1123 } 1124 } 1125 1126 /* 1127 * Mark a line dirty and consume the rest of it, keeping track of the 1128 * lexical state. 1129 */ 1130 static const char * 1131 skipline(const char *cp) 1132 { 1133 if (*cp != '\0') 1134 linestate = LS_DIRTY; 1135 while (*cp != '\0') 1136 cp = skipcomment(cp + 1); 1137 return (cp); 1138 } 1139 1140 /* 1141 * Skip over comments, strings, and character literals and stop at the 1142 * next character position that is not whitespace. Between calls we keep 1143 * the comment state in the global variable incomment, and we also adjust 1144 * the global variable linestate when we see a newline. 1145 * XXX: doesn't cope with the buffer splitting inside a state transition. 1146 */ 1147 static const char * 1148 skipcomment(const char *cp) 1149 { 1150 if (text || ignoring[depth]) { 1151 for (; isspace((unsigned char)*cp); cp++) 1152 if (*cp == '\n') 1153 linestate = LS_START; 1154 return (cp); 1155 } 1156 while (*cp != '\0') 1157 /* don't reset to LS_START after a line continuation */ 1158 if (strncmp(cp, "\\\r\n", 3) == 0) 1159 cp += 3; 1160 else if (strncmp(cp, "\\\n", 2) == 0) 1161 cp += 2; 1162 else switch (incomment) { 1163 case NO_COMMENT: 1164 if (strncmp(cp, "/\\\r\n", 4) == 0) { 1165 incomment = STARTING_COMMENT; 1166 cp += 4; 1167 } else if (strncmp(cp, "/\\\n", 3) == 0) { 1168 incomment = STARTING_COMMENT; 1169 cp += 3; 1170 } else if (strncmp(cp, "/*", 2) == 0) { 1171 incomment = C_COMMENT; 1172 cp += 2; 1173 } else if (strncmp(cp, "//", 2) == 0) { 1174 incomment = CXX_COMMENT; 1175 cp += 2; 1176 } else if (strncmp(cp, "\'", 1) == 0) { 1177 incomment = CHAR_LITERAL; 1178 linestate = LS_DIRTY; 1179 cp += 1; 1180 } else if (strncmp(cp, "\"", 1) == 0) { 1181 incomment = STRING_LITERAL; 1182 linestate = LS_DIRTY; 1183 cp += 1; 1184 } else if (strncmp(cp, "\n", 1) == 0) { 1185 linestate = LS_START; 1186 cp += 1; 1187 } else if (strchr(" \r\t", *cp) != NULL) { 1188 cp += 1; 1189 } else 1190 return (cp); 1191 continue; 1192 case CXX_COMMENT: 1193 if (strncmp(cp, "\n", 1) == 0) { 1194 incomment = NO_COMMENT; 1195 linestate = LS_START; 1196 } 1197 cp += 1; 1198 continue; 1199 case CHAR_LITERAL: 1200 case STRING_LITERAL: 1201 if ((incomment == CHAR_LITERAL && cp[0] == '\'') || 1202 (incomment == STRING_LITERAL && cp[0] == '\"')) { 1203 incomment = NO_COMMENT; 1204 cp += 1; 1205 } else if (cp[0] == '\\') { 1206 if (cp[1] == '\0') 1207 cp += 1; 1208 else 1209 cp += 2; 1210 } else if (strncmp(cp, "\n", 1) == 0) { 1211 if (incomment == CHAR_LITERAL) 1212 error("unterminated char literal"); 1213 else 1214 error("unterminated string literal"); 1215 } else 1216 cp += 1; 1217 continue; 1218 case C_COMMENT: 1219 if (strncmp(cp, "*\\\r\n", 4) == 0) { 1220 incomment = FINISHING_COMMENT; 1221 cp += 4; 1222 } else if (strncmp(cp, "*\\\n", 3) == 0) { 1223 incomment = FINISHING_COMMENT; 1224 cp += 3; 1225 } else if (strncmp(cp, "*/", 2) == 0) { 1226 incomment = NO_COMMENT; 1227 cp += 2; 1228 } else 1229 cp += 1; 1230 continue; 1231 case STARTING_COMMENT: 1232 if (*cp == '*') { 1233 incomment = C_COMMENT; 1234 cp += 1; 1235 } else if (*cp == '/') { 1236 incomment = CXX_COMMENT; 1237 cp += 1; 1238 } else { 1239 incomment = NO_COMMENT; 1240 linestate = LS_DIRTY; 1241 } 1242 continue; 1243 case FINISHING_COMMENT: 1244 if (*cp == '/') { 1245 incomment = NO_COMMENT; 1246 cp += 1; 1247 } else 1248 incomment = C_COMMENT; 1249 continue; 1250 default: 1251 abort(); /* bug */ 1252 } 1253 return (cp); 1254 } 1255 1256 /* 1257 * Skip macro arguments. 1258 */ 1259 static const char * 1260 skipargs(const char *cp) 1261 { 1262 const char *ocp = cp; 1263 int level = 0; 1264 cp = skipcomment(cp); 1265 if (*cp != '(') 1266 return (cp); 1267 do { 1268 if (*cp == '(') 1269 level++; 1270 if (*cp == ')') 1271 level--; 1272 cp = skipcomment(cp+1); 1273 } while (level != 0 && *cp != '\0'); 1274 if (level == 0) 1275 return (cp); 1276 else 1277 /* Rewind and re-detect the syntax error later. */ 1278 return (ocp); 1279 } 1280 1281 /* 1282 * Skip over an identifier. 1283 */ 1284 static const char * 1285 skipsym(const char *cp) 1286 { 1287 while (!endsym(*cp)) 1288 ++cp; 1289 return (cp); 1290 } 1291 1292 /* 1293 * Skip whitespace and take a copy of any following identifier. 1294 */ 1295 static const char * 1296 getsym(const char **cpp) 1297 { 1298 const char *cp = *cpp, *sym; 1299 1300 cp = skipcomment(cp); 1301 cp = skipsym(sym = cp); 1302 if (cp == sym) 1303 return NULL; 1304 *cpp = cp; 1305 return (xstrdup(sym, cp)); 1306 } 1307 1308 /* 1309 * Check that s (a symbol) matches the start of t, and that the 1310 * following character in t is not a symbol character. Returns a 1311 * pointer to the following character in t if there is a match, 1312 * otherwise NULL. 1313 */ 1314 static const char * 1315 matchsym(const char *s, const char *t) 1316 { 1317 while (*s != '\0' && *t != '\0') 1318 if (*s != *t) 1319 return (NULL); 1320 else 1321 ++s, ++t; 1322 if (*s == '\0' && endsym(*t)) 1323 return(t); 1324 else 1325 return(NULL); 1326 } 1327 1328 /* 1329 * Look for the symbol in the symbol table. If it is found, we return 1330 * the symbol table index, else we return -1. 1331 */ 1332 static int 1333 findsym(const char **strp) 1334 { 1335 const char *str; 1336 int symind; 1337 1338 str = *strp; 1339 *strp = skipsym(str); 1340 if (symlist) { 1341 if (*strp == str) 1342 return (-1); 1343 if (symdepth && firstsym) 1344 printf("%s%3d", zerosyms ? "" : "\n", depth); 1345 firstsym = zerosyms = false; 1346 printf("%s%.*s%s", 1347 symdepth ? " " : "", 1348 (int)(*strp-str), str, 1349 symdepth ? "" : "\n"); 1350 /* we don't care about the value of the symbol */ 1351 return (0); 1352 } 1353 for (symind = 0; symind < nsyms; ++symind) { 1354 if (matchsym(symname[symind], str) != NULL) { 1355 debugsym("findsym", symind); 1356 return (symind); 1357 } 1358 } 1359 return (-1); 1360 } 1361 1362 /* 1363 * Resolve indirect symbol values to their final definitions. 1364 */ 1365 static void 1366 indirectsym(void) 1367 { 1368 const char *cp; 1369 int changed, sym, ind; 1370 1371 do { 1372 changed = 0; 1373 for (sym = 0; sym < nsyms; ++sym) { 1374 if (value[sym] == NULL) 1375 continue; 1376 cp = value[sym]; 1377 ind = findsym(&cp); 1378 if (ind == -1 || ind == sym || 1379 *cp != '\0' || 1380 value[ind] == NULL || 1381 value[ind] == value[sym]) 1382 continue; 1383 debugsym("indir...", sym); 1384 value[sym] = value[ind]; 1385 debugsym("...ectsym", sym); 1386 changed++; 1387 } 1388 } while (changed); 1389 } 1390 1391 /* 1392 * Add a symbol to the symbol table, specified with the format sym=val 1393 */ 1394 static void 1395 addsym1(bool ignorethis, bool definethis, char *symval) 1396 { 1397 const char *sym, *val; 1398 1399 sym = symval; 1400 val = skipsym(sym); 1401 if (definethis && *val == '=') { 1402 symval[val - sym] = '\0'; 1403 val = val + 1; 1404 } else if (*val == '\0') { 1405 val = definethis ? "1" : NULL; 1406 } else { 1407 usage(); 1408 } 1409 addsym2(ignorethis, sym, val); 1410 } 1411 1412 /* 1413 * Add a symbol to the symbol table. 1414 */ 1415 static void 1416 addsym2(bool ignorethis, const char *sym, const char *val) 1417 { 1418 const char *cp = sym; 1419 int symind; 1420 1421 symind = findsym(&cp); 1422 if (symind < 0) { 1423 if (nsyms >= MAXSYMS) 1424 errx(2, "too many symbols"); 1425 symind = nsyms++; 1426 } 1427 ignore[symind] = ignorethis; 1428 symname[symind] = sym; 1429 value[symind] = val; 1430 debugsym("addsym", symind); 1431 } 1432 1433 static void 1434 debugsym(const char *why, int symind) 1435 { 1436 debug("%s %s%c%s", why, symname[symind], 1437 value[symind] ? '=' : ' ', 1438 value[symind] ? value[symind] : "undef"); 1439 } 1440 1441 /* 1442 * Add symbols to the symbol table from a file containing 1443 * #define and #undef preprocessor directives. 1444 */ 1445 static void 1446 defundefile(const char *fn) 1447 { 1448 filename = fn; 1449 input = fopen(fn, "rb"); 1450 if (input == NULL) 1451 err(2, "can't open %s", fn); 1452 linenum = 0; 1453 while (defundef()) 1454 ; 1455 if (ferror(input)) 1456 err(2, "can't read %s", filename); 1457 else 1458 fclose(input); 1459 if (incomment) 1460 error("EOF in comment"); 1461 } 1462 1463 /* 1464 * Read and process one #define or #undef directive 1465 */ 1466 static bool 1467 defundef(void) 1468 { 1469 const char *cp, *kw, *sym, *val, *end; 1470 1471 cp = skiphash(); 1472 if (cp == NULL) 1473 return (false); 1474 if (*cp == '\0') 1475 goto done; 1476 /* strip trailing whitespace, and do a fairly rough check to 1477 avoid unsupported multi-line preprocessor directives */ 1478 end = cp + strlen(cp); 1479 while (end > tline && strchr(" \t\n\r", end[-1]) != NULL) 1480 --end; 1481 if (end > tline && end[-1] == '\\') 1482 Eioccc(); 1483 1484 kw = cp; 1485 if ((cp = matchsym("define", kw)) != NULL) { 1486 sym = getsym(&cp); 1487 if (sym == NULL) 1488 error("missing macro name in #define"); 1489 if (*cp == '(') { 1490 val = "1"; 1491 } else { 1492 cp = skipcomment(cp); 1493 val = (cp < end) ? xstrdup(cp, end) : ""; 1494 } 1495 debug("#define"); 1496 addsym2(false, sym, val); 1497 } else if ((cp = matchsym("undef", kw)) != NULL) { 1498 sym = getsym(&cp); 1499 if (sym == NULL) 1500 error("missing macro name in #undef"); 1501 cp = skipcomment(cp); 1502 debug("#undef"); 1503 addsym2(false, sym, NULL); 1504 } else { 1505 error("unrecognized preprocessor directive"); 1506 } 1507 skipline(cp); 1508 done: 1509 debug("parser line %d state %s comment %s line", linenum, 1510 comment_name[incomment], linestate_name[linestate]); 1511 return (true); 1512 } 1513 1514 /* 1515 * Concatenate two strings into new memory, checking for failure. 1516 */ 1517 static char * 1518 astrcat(const char *s1, const char *s2) 1519 { 1520 char *s; 1521 int len; 1522 size_t size; 1523 1524 len = snprintf(NULL, 0, "%s%s", s1, s2); 1525 if (len < 0) 1526 err(2, "snprintf"); 1527 size = (size_t)len + 1; 1528 s = (char *)malloc(size); 1529 if (s == NULL) 1530 err(2, "malloc"); 1531 snprintf(s, size, "%s%s", s1, s2); 1532 return (s); 1533 } 1534 1535 /* 1536 * Duplicate a segment of a string, checking for failure. 1537 */ 1538 static const char * 1539 xstrdup(const char *start, const char *end) 1540 { 1541 size_t n; 1542 char *s; 1543 1544 if (end < start) abort(); /* bug */ 1545 n = (size_t)(end - start) + 1; 1546 s = malloc(n); 1547 if (s == NULL) 1548 err(2, "malloc"); 1549 snprintf(s, n, "%s", start); 1550 return (s); 1551 } 1552 1553 /* 1554 * Diagnostics. 1555 */ 1556 static void 1557 debug(const char *msg, ...) 1558 { 1559 va_list ap; 1560 1561 if (debugging) { 1562 va_start(ap, msg); 1563 vwarnx(msg, ap); 1564 va_end(ap); 1565 } 1566 } 1567 1568 static void 1569 error(const char *msg) 1570 { 1571 if (depth == 0) 1572 warnx("%s: %d: %s", filename, linenum, msg); 1573 else 1574 warnx("%s: %d: %s (#if line %d depth %d)", 1575 filename, linenum, msg, stifline[depth], depth); 1576 closeio(); 1577 errx(2, "output may be truncated"); 1578 } 1579