1/* 2 * Copyright (c) 2002 - 2011 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 <sys/types.h> 47#include <sys/stat.h> 48 49#include <ctype.h> 50#include <err.h> 51#include <errno.h> 52#include <stdarg.h> 53#include <stdbool.h> 54#include <stdio.h> 55#include <stdlib.h> 56#include <string.h> 57#include <unistd.h> 58 59const char copyright[] = 60 "@(#) $Version: unifdef-2.5.6.21f1388 $\n" 61 "@(#) $FreeBSD$\n" 62 "@(#) $Author: Tony Finch (dot@dotat.at) $\n" 63 "@(#) $URL: http://dotat.at/prog/unifdef $\n" 64; 65 66/* types of input lines: */ 67typedef enum { 68 LT_TRUEI, /* a true #if with ignore flag */ 69 LT_FALSEI, /* a false #if with ignore flag */ 70 LT_IF, /* an unknown #if */ 71 LT_TRUE, /* a true #if */ 72 LT_FALSE, /* a false #if */ 73 LT_ELIF, /* an unknown #elif */ 74 LT_ELTRUE, /* a true #elif */ 75 LT_ELFALSE, /* a false #elif */ 76 LT_ELSE, /* #else */ 77 LT_ENDIF, /* #endif */ 78 LT_DODGY, /* flag: directive is not on one line */ 79 LT_DODGY_LAST = LT_DODGY + LT_ENDIF, 80 LT_PLAIN, /* ordinary line */ 81 LT_EOF, /* end of file */ 82 LT_ERROR, /* unevaluable #if */ 83 LT_COUNT 84} Linetype; 85 86static char const * const linetype_name[] = { 87 "TRUEI", "FALSEI", "IF", "TRUE", "FALSE", 88 "ELIF", "ELTRUE", "ELFALSE", "ELSE", "ENDIF", 89 "DODGY TRUEI", "DODGY FALSEI", 90 "DODGY IF", "DODGY TRUE", "DODGY FALSE", 91 "DODGY ELIF", "DODGY ELTRUE", "DODGY ELFALSE", 92 "DODGY ELSE", "DODGY ENDIF", 93 "PLAIN", "EOF", "ERROR" 94}; 95 96/* state of #if processing */ 97typedef enum { 98 IS_OUTSIDE, 99 IS_FALSE_PREFIX, /* false #if followed by false #elifs */ 100 IS_TRUE_PREFIX, /* first non-false #(el)if is true */ 101 IS_PASS_MIDDLE, /* first non-false #(el)if is unknown */ 102 IS_FALSE_MIDDLE, /* a false #elif after a pass state */ 103 IS_TRUE_MIDDLE, /* a true #elif after a pass state */ 104 IS_PASS_ELSE, /* an else after a pass state */ 105 IS_FALSE_ELSE, /* an else after a true state */ 106 IS_TRUE_ELSE, /* an else after only false states */ 107 IS_FALSE_TRAILER, /* #elifs after a true are false */ 108 IS_COUNT 109} Ifstate; 110 111static char const * const ifstate_name[] = { 112 "OUTSIDE", "FALSE_PREFIX", "TRUE_PREFIX", 113 "PASS_MIDDLE", "FALSE_MIDDLE", "TRUE_MIDDLE", 114 "PASS_ELSE", "FALSE_ELSE", "TRUE_ELSE", 115 "FALSE_TRAILER" 116}; 117 118/* state of comment parser */ 119typedef enum { 120 NO_COMMENT = false, /* outside a comment */ 121 C_COMMENT, /* in a comment like this one */ 122 CXX_COMMENT, /* between // and end of line */ 123 STARTING_COMMENT, /* just after slash-backslash-newline */ 124 FINISHING_COMMENT, /* star-backslash-newline in a C comment */ 125 CHAR_LITERAL, /* inside '' */ 126 STRING_LITERAL /* inside "" */ 127} Comment_state; 128 129static char const * const comment_name[] = { 130 "NO", "C", "CXX", "STARTING", "FINISHING", "CHAR", "STRING" 131}; 132 133/* state of preprocessor line parser */ 134typedef enum { 135 LS_START, /* only space and comments on this line */ 136 LS_HASH, /* only space, comments, and a hash */ 137 LS_DIRTY /* this line can't be a preprocessor line */ 138} Line_state; 139 140static char const * const linestate_name[] = { 141 "START", "HASH", "DIRTY" 142}; 143 144/* 145 * Minimum translation limits from ISO/IEC 9899:1999 5.2.4.1 146 */ 147#define MAXDEPTH 64 /* maximum #if nesting */ 148#define MAXLINE 4096 /* maximum length of line */ 149#define MAXSYMS 4096 /* maximum number of symbols */ 150 151/* 152 * Sometimes when editing a keyword the replacement text is longer, so 153 * we leave some space at the end of the tline buffer to accommodate this. 154 */ 155#define EDITSLOP 10 156 157/* 158 * For temporary filenames 159 */ 160#define TEMPLATE "unifdef.XXXXXX" 161 162/* 163 * Globals. 164 */ 165 166static bool compblank; /* -B: compress blank lines */ 167static bool lnblank; /* -b: blank deleted lines */ 168static bool complement; /* -c: do the complement */ 169static bool debugging; /* -d: debugging reports */ 170static bool iocccok; /* -e: fewer IOCCC errors */ 171static bool strictlogic; /* -K: keep ambiguous #ifs */ 172static bool killconsts; /* -k: eval constant #ifs */ 173static bool lnnum; /* -n: add #line directives */ 174static bool symlist; /* -s: output symbol list */ 175static bool symdepth; /* -S: output symbol depth */ 176static bool text; /* -t: this is a text file */ 177 178static const char *symname[MAXSYMS]; /* symbol name */ 179static const char *value[MAXSYMS]; /* -Dsym=value */ 180static bool ignore[MAXSYMS]; /* -iDsym or -iUsym */ 181static int nsyms; /* number of symbols */ 182 183static FILE *input; /* input file pointer */ 184static const char *filename; /* input file name */ 185static int linenum; /* current line number */ 186static FILE *output; /* output file pointer */ 187static const char *ofilename; /* output file name */ 188static bool overwriting; /* output overwrites input */ 189static char tempname[FILENAME_MAX]; /* used when overwriting */ 190 191static char tline[MAXLINE+EDITSLOP];/* input buffer plus space */ 192static char *keyword; /* used for editing #elif's */ 193 194static const char *newline; /* input file format */ 195static const char newline_unix[] = "\n"; 196static const char newline_crlf[] = "\r\n"; 197 198static Comment_state incomment; /* comment parser state */ 199static Line_state linestate; /* #if line parser state */ 200static Ifstate ifstate[MAXDEPTH]; /* #if processor state */ 201static bool ignoring[MAXDEPTH]; /* ignore comments state */ 202static int stifline[MAXDEPTH]; /* start of current #if */ 203static int depth; /* current #if nesting */ 204static int delcount; /* count of deleted lines */ 205static unsigned blankcount; /* count of blank lines */ 206static unsigned blankmax; /* maximum recent blankcount */ 207static bool constexpr; /* constant #if expression */ 208static bool zerosyms = true; /* to format symdepth output */ 209static bool firstsym; /* ditto */ 210 211static int exitstat; /* program exit status */ 212 213static void addsym(bool, bool, char *); 214static void closeout(void); 215static void debug(const char *, ...); 216static void done(void); 217static void error(const char *); 218static int findsym(const char *); 219static void flushline(bool); 220static Linetype parseline(void); 221static Linetype ifeval(const char **); 222static void ignoreoff(void); 223static void ignoreon(void); 224static void keywordedit(const char *); 225static void nest(void); 226static void process(void); 227static const char *skipargs(const char *); 228static const char *skipcomment(const char *); 229static const char *skipsym(const char *); 230static void state(Ifstate); 231static int strlcmp(const char *, const char *, size_t); 232static void unnest(void); 233static void usage(void); 234static void version(void); 235 236#define endsym(c) (!isalnum((unsigned char)c) && c != '_') 237 238/* 239 * The main program. 240 */ 241int 242main(int argc, char *argv[]) 243{ 244 int opt; 245 246 while ((opt = getopt(argc, argv, "i:D:U:I:o:bBcdeKklnsStV")) != -1) 247 switch (opt) { 248 case 'i': /* treat stuff controlled by these symbols as text */ 249 /* 250 * For strict backwards-compatibility the U or D 251 * should be immediately after the -i but it doesn't 252 * matter much if we relax that requirement. 253 */ 254 opt = *optarg++; 255 if (opt == 'D') 256 addsym(true, true, optarg); 257 else if (opt == 'U') 258 addsym(true, false, optarg); 259 else 260 usage(); 261 break; 262 case 'D': /* define a symbol */ 263 addsym(false, true, optarg); 264 break; 265 case 'U': /* undef a symbol */ 266 addsym(false, false, optarg); 267 break; 268 case 'I': /* no-op for compatibility with cpp */ 269 break; 270 case 'b': /* blank deleted lines instead of omitting them */ 271 case 'l': /* backwards compatibility */ 272 lnblank = true; 273 break; 274 case 'B': /* compress blank lines around removed section */ 275 compblank = true; 276 break; 277 case 'c': /* treat -D as -U and vice versa */ 278 complement = true; 279 break; 280 case 'd': 281 debugging = true; 282 break; 283 case 'e': /* fewer errors from dodgy lines */ 284 iocccok = true; 285 break; 286 case 'K': /* keep ambiguous #ifs */ 287 strictlogic = true; 288 break; 289 case 'k': /* process constant #ifs */ 290 killconsts = true; 291 break; 292 case 'n': /* add #line directive after deleted lines */ 293 lnnum = true; 294 break; 295 case 'o': /* output to a file */ 296 ofilename = optarg; 297 break; 298 case 's': /* only output list of symbols that control #ifs */ 299 symlist = true; 300 break; 301 case 'S': /* list symbols with their nesting depth */ 302 symlist = symdepth = true; 303 break; 304 case 't': /* don't parse C comments */ 305 text = true; 306 break; 307 case 'V': /* print version */ 308 version(); 309 default: 310 usage(); 311 } 312 argc -= optind; 313 argv += optind; 314 if (compblank && lnblank) 315 errx(2, "-B and -b are mutually exclusive"); 316 if (argc > 1) { 317 errx(2, "can only do one file"); 318 } else if (argc == 1 && strcmp(*argv, "-") != 0) { 319 filename = *argv; 320 input = fopen(filename, "rb"); 321 if (input == NULL) 322 err(2, "can't open %s", filename); 323 } else { 324 filename = "[stdin]"; 325 input = stdin; 326 } 327 if (ofilename == NULL) { 328 ofilename = "[stdout]"; 329 output = stdout; 330 } else { 331 struct stat ist, ost; 332 if (stat(ofilename, &ost) == 0 && 333 fstat(fileno(input), &ist) == 0) 334 overwriting = (ist.st_dev == ost.st_dev 335 && ist.st_ino == ost.st_ino); 336 if (overwriting) { 337 const char *dirsep; 338 int ofd; 339 340 dirsep = strrchr(ofilename, '/'); 341 if (dirsep != NULL) 342 snprintf(tempname, sizeof(tempname), 343 "%.*s/" TEMPLATE, 344 (int)(dirsep - ofilename), ofilename); 345 else 346 snprintf(tempname, sizeof(tempname), 347 TEMPLATE); 348 ofd = mkstemp(tempname); 349 if (ofd != -1) 350 output = fdopen(ofd, "wb+"); 351 if (output == NULL) 352 err(2, "can't create temporary file"); 353 fchmod(ofd, ist.st_mode & (S_IRWXU|S_IRWXG|S_IRWXO)); 354 } else { 355 output = fopen(ofilename, "wb"); 356 if (output == NULL) 357 err(2, "can't open %s", ofilename); 358 } 359 } 360 process(); 361 abort(); /* bug */ 362} 363 364static void 365version(void) 366{ 367 const char *c = copyright; 368 for (;;) { 369 while (*++c != '$') 370 if (*c == '\0') 371 exit(0); 372 while (*++c != '$') 373 putc(*c, stderr); 374 putc('\n', stderr); 375 } 376} 377 378static void 379usage(void) 380{ 381 fprintf(stderr, "usage: unifdef [-bBcdeKknsStV] [-Ipath]" 382 " [-Dsym[=val]] [-Usym] [-iDsym[=val]] [-iUsym] ... [file]\n"); 383 exit(2); 384} 385 386/* 387 * A state transition function alters the global #if processing state 388 * in a particular way. The table below is indexed by the current 389 * processing state and the type of the current line. 390 * 391 * Nesting is handled by keeping a stack of states; some transition 392 * functions increase or decrease the depth. They also maintain the 393 * ignore state on a stack. In some complicated cases they have to 394 * alter the preprocessor directive, as follows. 395 * 396 * When we have processed a group that starts off with a known-false 397 * #if/#elif sequence (which has therefore been deleted) followed by a 398 * #elif that we don't understand and therefore must keep, we edit the 399 * latter into a #if to keep the nesting correct. We use strncpy() to 400 * overwrite the 4 byte token "elif" with "if " without a '\0' byte. 401 * 402 * When we find a true #elif in a group, the following block will 403 * always be kept and the rest of the sequence after the next #elif or 404 * #else will be discarded. We edit the #elif into a #else and the 405 * following directive to #endif since this has the desired behaviour. 406 * 407 * "Dodgy" directives are split across multiple lines, the most common 408 * example being a multi-line comment hanging off the right of the 409 * directive. We can handle them correctly only if there is no change 410 * from printing to dropping (or vice versa) caused by that directive. 411 * If the directive is the first of a group we have a choice between 412 * failing with an error, or passing it through unchanged instead of 413 * evaluating it. The latter is not the default to avoid questions from 414 * users about unifdef unexpectedly leaving behind preprocessor directives. 415 */ 416typedef void state_fn(void); 417 418/* report an error */ 419static void Eelif (void) { error("Inappropriate #elif"); } 420static void Eelse (void) { error("Inappropriate #else"); } 421static void Eendif(void) { error("Inappropriate #endif"); } 422static void Eeof (void) { error("Premature EOF"); } 423static void Eioccc(void) { error("Obfuscated preprocessor control line"); } 424/* plain line handling */ 425static void print (void) { flushline(true); } 426static void drop (void) { flushline(false); } 427/* output lacks group's start line */ 428static void Strue (void) { drop(); ignoreoff(); state(IS_TRUE_PREFIX); } 429static void Sfalse(void) { drop(); ignoreoff(); state(IS_FALSE_PREFIX); } 430static void Selse (void) { drop(); state(IS_TRUE_ELSE); } 431/* print/pass this block */ 432static void Pelif (void) { print(); ignoreoff(); state(IS_PASS_MIDDLE); } 433static void Pelse (void) { print(); state(IS_PASS_ELSE); } 434static void Pendif(void) { print(); unnest(); } 435/* discard this block */ 436static void Dfalse(void) { drop(); ignoreoff(); state(IS_FALSE_TRAILER); } 437static void Delif (void) { drop(); ignoreoff(); state(IS_FALSE_MIDDLE); } 438static void Delse (void) { drop(); state(IS_FALSE_ELSE); } 439static void Dendif(void) { drop(); unnest(); } 440/* first line of group */ 441static void Fdrop (void) { nest(); Dfalse(); } 442static void Fpass (void) { nest(); Pelif(); } 443static void Ftrue (void) { nest(); Strue(); } 444static void Ffalse(void) { nest(); Sfalse(); } 445/* variable pedantry for obfuscated lines */ 446static void Oiffy (void) { if (!iocccok) Eioccc(); Fpass(); ignoreon(); } 447static void Oif (void) { if (!iocccok) Eioccc(); Fpass(); } 448static void Oelif (void) { if (!iocccok) Eioccc(); Pelif(); } 449/* ignore comments in this block */ 450static void Idrop (void) { Fdrop(); ignoreon(); } 451static void Itrue (void) { Ftrue(); ignoreon(); } 452static void Ifalse(void) { Ffalse(); ignoreon(); } 453/* modify this line */ 454static void Mpass (void) { strncpy(keyword, "if ", 4); Pelif(); } 455static void Mtrue (void) { keywordedit("else"); state(IS_TRUE_MIDDLE); } 456static void Melif (void) { keywordedit("endif"); state(IS_FALSE_TRAILER); } 457static void Melse (void) { keywordedit("endif"); state(IS_FALSE_ELSE); } 458 459static state_fn * const trans_table[IS_COUNT][LT_COUNT] = { 460/* IS_OUTSIDE */ 461{ Itrue, Ifalse,Fpass, Ftrue, Ffalse,Eelif, Eelif, Eelif, Eelse, Eendif, 462 Oiffy, Oiffy, Fpass, Oif, Oif, Eelif, Eelif, Eelif, Eelse, Eendif, 463 print, done, abort }, 464/* IS_FALSE_PREFIX */ 465{ Idrop, Idrop, Fdrop, Fdrop, Fdrop, Mpass, Strue, Sfalse,Selse, Dendif, 466 Idrop, Idrop, Fdrop, Fdrop, Fdrop, Mpass, Eioccc,Eioccc,Eioccc,Eioccc, 467 drop, Eeof, abort }, 468/* IS_TRUE_PREFIX */ 469{ Itrue, Ifalse,Fpass, Ftrue, Ffalse,Dfalse,Dfalse,Dfalse,Delse, Dendif, 470 Oiffy, Oiffy, Fpass, Oif, Oif, Eioccc,Eioccc,Eioccc,Eioccc,Eioccc, 471 print, Eeof, abort }, 472/* IS_PASS_MIDDLE */ 473{ Itrue, Ifalse,Fpass, Ftrue, Ffalse,Pelif, Mtrue, Delif, Pelse, Pendif, 474 Oiffy, Oiffy, Fpass, Oif, Oif, Pelif, Oelif, Oelif, Pelse, Pendif, 475 print, Eeof, abort }, 476/* IS_FALSE_MIDDLE */ 477{ Idrop, Idrop, Fdrop, Fdrop, Fdrop, Pelif, Mtrue, Delif, Pelse, Pendif, 478 Idrop, Idrop, Fdrop, Fdrop, Fdrop, Eioccc,Eioccc,Eioccc,Eioccc,Eioccc, 479 drop, Eeof, abort }, 480/* IS_TRUE_MIDDLE */ 481{ Itrue, Ifalse,Fpass, Ftrue, Ffalse,Melif, Melif, Melif, Melse, Pendif, 482 Oiffy, Oiffy, Fpass, Oif, Oif, Eioccc,Eioccc,Eioccc,Eioccc,Pendif, 483 print, Eeof, abort }, 484/* IS_PASS_ELSE */ 485{ Itrue, Ifalse,Fpass, Ftrue, Ffalse,Eelif, Eelif, Eelif, Eelse, Pendif, 486 Oiffy, Oiffy, Fpass, Oif, Oif, Eelif, Eelif, Eelif, Eelse, Pendif, 487 print, Eeof, abort }, 488/* IS_FALSE_ELSE */ 489{ Idrop, Idrop, Fdrop, Fdrop, Fdrop, Eelif, Eelif, Eelif, Eelse, Dendif, 490 Idrop, Idrop, Fdrop, Fdrop, Fdrop, Eelif, Eelif, Eelif, Eelse, Eioccc, 491 drop, Eeof, abort }, 492/* IS_TRUE_ELSE */ 493{ Itrue, Ifalse,Fpass, Ftrue, Ffalse,Eelif, Eelif, Eelif, Eelse, Dendif, 494 Oiffy, Oiffy, Fpass, Oif, Oif, Eelif, Eelif, Eelif, Eelse, Eioccc, 495 print, Eeof, abort }, 496/* IS_FALSE_TRAILER */ 497{ Idrop, Idrop, Fdrop, Fdrop, Fdrop, Dfalse,Dfalse,Dfalse,Delse, Dendif, 498 Idrop, Idrop, Fdrop, Fdrop, Fdrop, Dfalse,Dfalse,Dfalse,Delse, Eioccc, 499 drop, Eeof, abort } 500/*TRUEI FALSEI IF TRUE FALSE ELIF ELTRUE ELFALSE ELSE ENDIF 501 TRUEI FALSEI IF TRUE FALSE ELIF ELTRUE ELFALSE ELSE ENDIF (DODGY) 502 PLAIN EOF ERROR */ 503}; 504 505/* 506 * State machine utility functions 507 */ 508static void 509ignoreoff(void) 510{ 511 if (depth == 0) 512 abort(); /* bug */ 513 ignoring[depth] = ignoring[depth-1]; 514} 515static void 516ignoreon(void) 517{ 518 ignoring[depth] = true; 519} 520static void 521keywordedit(const char *replacement) 522{ 523 snprintf(keyword, tline + sizeof(tline) - keyword, 524 "%s%s", replacement, newline); 525 print(); 526} 527static void 528nest(void) 529{ 530 if (depth > MAXDEPTH-1) 531 abort(); /* bug */ 532 if (depth == MAXDEPTH-1) 533 error("Too many levels of nesting"); 534 depth += 1; 535 stifline[depth] = linenum; 536} 537static void 538unnest(void) 539{ 540 if (depth == 0) 541 abort(); /* bug */ 542 depth -= 1; 543} 544static void 545state(Ifstate is) 546{ 547 ifstate[depth] = is; 548} 549 550/* 551 * Write a line to the output or not, according to command line options. 552 * If writing fails, closeout() will print the error and exit. 553 */ 554static void 555flushline(bool keep) 556{ 557 if (symlist) 558 return; 559 if (keep ^ complement) { 560 bool blankline = tline[strspn(tline, " \t\r\n")] == '\0'; 561 if (blankline && compblank && blankcount != blankmax) { 562 delcount += 1; 563 blankcount += 1; 564 } else { 565 if (lnnum && delcount > 0 && 566 fprintf(output, "#line %d%s", linenum, newline) < 0) 567 closeout(); 568 if (fputs(tline, output) == EOF) 569 closeout(); 570 delcount = 0; 571 blankmax = blankcount = blankline ? blankcount + 1 : 0; 572 } 573 } else { 574 if (lnblank && fputs(newline, output) == EOF) 575 closeout(); 576 exitstat = 1; 577 delcount += 1; 578 blankcount = 0; 579 } 580 if (debugging && fflush(output) == EOF) 581 closeout(); 582} 583 584/* 585 * The driver for the state machine. 586 */ 587static void 588process(void) 589{ 590 /* When compressing blank lines, act as if the file 591 is preceded by a large number of blank lines. */ 592 blankmax = blankcount = 1000; 593 for (;;) { 594 Linetype lineval = parseline(); 595 trans_table[ifstate[depth]][lineval](); 596 debug("process line %d %s -> %s depth %d", 597 linenum, linetype_name[lineval], 598 ifstate_name[ifstate[depth]], depth); 599 } 600} 601 602/* 603 * Flush the output and handle errors. 604 */ 605static void 606closeout(void) 607{ 608 if (symdepth && !zerosyms) 609 printf("\n"); 610 if (ferror(output) || fclose(output) == EOF) { 611 if (overwriting) { 612 warn("couldn't write to temporary file"); 613 unlink(tempname); 614 errx(2, "%s unchanged", ofilename); 615 } else { 616 err(2, "couldn't write to %s", ofilename); 617 } 618 } 619} 620 621/* 622 * Clean up and exit. 623 */ 624static void 625done(void) 626{ 627 if (incomment) 628 error("EOF in comment"); 629 closeout(); 630 if (overwriting && rename(tempname, ofilename) == -1) { 631 warn("couldn't rename temporary file"); 632 unlink(tempname); 633 errx(2, "%s unchanged", ofilename); 634 } 635 exit(exitstat); 636} 637 638/* 639 * Parse a line and determine its type. We keep the preprocessor line 640 * parser state between calls in the global variable linestate, with 641 * help from skipcomment(). 642 */ 643static Linetype 644parseline(void) 645{ 646 const char *cp; 647 int cursym; 648 int kwlen; 649 Linetype retval; 650 Comment_state wascomment; 651 652 linenum++; 653 if (fgets(tline, MAXLINE, input) == NULL) { 654 if (ferror(input)) 655 error(strerror(errno)); 656 else 657 return (LT_EOF); 658 } 659 if (newline == NULL) { 660 if (strrchr(tline, '\n') == strrchr(tline, '\r') + 1) 661 newline = newline_crlf; 662 else 663 newline = newline_unix; 664 } 665 retval = LT_PLAIN; 666 wascomment = incomment; 667 cp = skipcomment(tline); 668 if (linestate == LS_START) { 669 if (*cp == '#') { 670 linestate = LS_HASH; 671 firstsym = true; 672 cp = skipcomment(cp + 1); 673 } else if (*cp != '\0') 674 linestate = LS_DIRTY; 675 } 676 if (!incomment && linestate == LS_HASH) { 677 keyword = tline + (cp - tline); 678 cp = skipsym(cp); 679 kwlen = cp - keyword; 680 /* no way can we deal with a continuation inside a keyword */ 681 if (strncmp(cp, "\\\r\n", 3) == 0 || 682 strncmp(cp, "\\\n", 2) == 0) 683 Eioccc(); 684 if (strlcmp("ifdef", keyword, kwlen) == 0 || 685 strlcmp("ifndef", keyword, kwlen) == 0) { 686 cp = skipcomment(cp); 687 if ((cursym = findsym(cp)) < 0) 688 retval = LT_IF; 689 else { 690 retval = (keyword[2] == 'n') 691 ? LT_FALSE : LT_TRUE; 692 if (value[cursym] == NULL) 693 retval = (retval == LT_TRUE) 694 ? LT_FALSE : LT_TRUE; 695 if (ignore[cursym]) 696 retval = (retval == LT_TRUE) 697 ? LT_TRUEI : LT_FALSEI; 698 } 699 cp = skipsym(cp); 700 } else if (strlcmp("if", keyword, kwlen) == 0) 701 retval = ifeval(&cp); 702 else if (strlcmp("elif", keyword, kwlen) == 0) 703 retval = ifeval(&cp) - LT_IF + LT_ELIF; 704 else if (strlcmp("else", keyword, kwlen) == 0) 705 retval = LT_ELSE; 706 else if (strlcmp("endif", keyword, kwlen) == 0) 707 retval = LT_ENDIF; 708 else { 709 linestate = LS_DIRTY; 710 retval = LT_PLAIN; 711 } 712 cp = skipcomment(cp); 713 if (*cp != '\0') { 714 linestate = LS_DIRTY; 715 if (retval == LT_TRUE || retval == LT_FALSE || 716 retval == LT_TRUEI || retval == LT_FALSEI) 717 retval = LT_IF; 718 if (retval == LT_ELTRUE || retval == LT_ELFALSE) 719 retval = LT_ELIF; 720 } 721 if (retval != LT_PLAIN && (wascomment || incomment)) { 722 retval += LT_DODGY; 723 if (incomment) 724 linestate = LS_DIRTY; 725 } 726 /* skipcomment normally changes the state, except 727 if the last line of the file lacks a newline, or 728 if there is too much whitespace in a directive */ 729 if (linestate == LS_HASH) { 730 size_t len = cp - tline; 731 if (fgets(tline + len, MAXLINE - len, input) == NULL) { 732 if (ferror(input)) 733 error(strerror(errno)); 734 /* append the missing newline at eof */ 735 strcpy(tline + len, newline); 736 cp += strlen(newline); 737 linestate = LS_START; 738 } else { 739 linestate = LS_DIRTY; 740 } 741 } 742 } 743 if (linestate == LS_DIRTY) { 744 while (*cp != '\0') 745 cp = skipcomment(cp + 1); 746 } 747 debug("parser line %d state %s comment %s line", linenum, 748 comment_name[incomment], linestate_name[linestate]); 749 return (retval); 750} 751 752/* 753 * These are the binary operators that are supported by the expression 754 * evaluator. 755 */ 756static Linetype op_strict(int *p, int v, Linetype at, Linetype bt) { 757 if(at == LT_IF || bt == LT_IF) return (LT_IF); 758 return (*p = v, v ? LT_TRUE : LT_FALSE); 759} 760static Linetype op_lt(int *p, Linetype at, int a, Linetype bt, int b) { 761 return op_strict(p, a < b, at, bt); 762} 763static Linetype op_gt(int *p, Linetype at, int a, Linetype bt, int b) { 764 return op_strict(p, a > b, at, bt); 765} 766static Linetype op_le(int *p, Linetype at, int a, Linetype bt, int b) { 767 return op_strict(p, a <= b, at, bt); 768} 769static Linetype op_ge(int *p, Linetype at, int a, Linetype bt, int b) { 770 return op_strict(p, a >= b, at, bt); 771} 772static Linetype op_eq(int *p, Linetype at, int a, Linetype bt, int b) { 773 return op_strict(p, a == b, at, bt); 774} 775static Linetype op_ne(int *p, Linetype at, int a, Linetype bt, int b) { 776 return op_strict(p, a != b, at, bt); 777} 778static Linetype op_or(int *p, Linetype at, int a, Linetype bt, int b) { 779 if (!strictlogic && (at == LT_TRUE || bt == LT_TRUE)) 780 return (*p = 1, LT_TRUE); 781 return op_strict(p, a || b, at, bt); 782} 783static Linetype op_and(int *p, Linetype at, int a, Linetype bt, int b) { 784 if (!strictlogic && (at == LT_FALSE || bt == LT_FALSE)) 785 return (*p = 0, LT_FALSE); 786 return op_strict(p, a && b, at, bt); 787} 788 789/* 790 * An evaluation function takes three arguments, as follows: (1) a pointer to 791 * an element of the precedence table which lists the operators at the current 792 * level of precedence; (2) a pointer to an integer which will receive the 793 * value of the expression; and (3) a pointer to a char* that points to the 794 * expression to be evaluated and that is updated to the end of the expression 795 * when evaluation is complete. The function returns LT_FALSE if the value of 796 * the expression is zero, LT_TRUE if it is non-zero, LT_IF if the expression 797 * depends on an unknown symbol, or LT_ERROR if there is a parse failure. 798 */ 799struct ops; 800 801typedef Linetype eval_fn(const struct ops *, int *, const char **); 802 803static eval_fn eval_table, eval_unary; 804 805/* 806 * The precedence table. Expressions involving binary operators are evaluated 807 * in a table-driven way by eval_table. When it evaluates a subexpression it 808 * calls the inner function with its first argument pointing to the next 809 * element of the table. Innermost expressions have special non-table-driven 810 * handling. 811 */ 812static const struct ops { 813 eval_fn *inner; 814 struct op { 815 const char *str; 816 Linetype (*fn)(int *, Linetype, int, Linetype, int); 817 } op[5]; 818} eval_ops[] = { 819 { eval_table, { { "||", op_or } } }, 820 { eval_table, { { "&&", op_and } } }, 821 { eval_table, { { "==", op_eq }, 822 { "!=", op_ne } } }, 823 { eval_unary, { { "<=", op_le }, 824 { ">=", op_ge }, 825 { "<", op_lt }, 826 { ">", op_gt } } } 827}; 828 829/* 830 * Function for evaluating the innermost parts of expressions, 831 * viz. !expr (expr) number defined(symbol) symbol 832 * We reset the constexpr flag in the last two cases. 833 */ 834static Linetype 835eval_unary(const struct ops *ops, int *valp, const char **cpp) 836{ 837 const char *cp; 838 char *ep; 839 int sym; 840 bool defparen; 841 Linetype lt; 842 843 cp = skipcomment(*cpp); 844 if (*cp == '!') { 845 debug("eval%d !", ops - eval_ops); 846 cp++; 847 lt = eval_unary(ops, valp, &cp); 848 if (lt == LT_ERROR) 849 return (LT_ERROR); 850 if (lt != LT_IF) { 851 *valp = !*valp; 852 lt = *valp ? LT_TRUE : LT_FALSE; 853 } 854 } else if (*cp == '(') { 855 cp++; 856 debug("eval%d (", ops - eval_ops); 857 lt = eval_table(eval_ops, valp, &cp); 858 if (lt == LT_ERROR) 859 return (LT_ERROR); 860 cp = skipcomment(cp); 861 if (*cp++ != ')') 862 return (LT_ERROR); 863 } else if (isdigit((unsigned char)*cp)) { 864 debug("eval%d number", ops - eval_ops); 865 *valp = strtol(cp, &ep, 0); 866 if (ep == cp) 867 return (LT_ERROR); 868 lt = *valp ? LT_TRUE : LT_FALSE; 869 cp = skipsym(cp); 870 } else if (strncmp(cp, "defined", 7) == 0 && endsym(cp[7])) { 871 cp = skipcomment(cp+7); 872 debug("eval%d defined", ops - eval_ops); 873 if (*cp == '(') { 874 cp = skipcomment(cp+1); 875 defparen = true; 876 } else { 877 defparen = false; 878 } 879 sym = findsym(cp); 880 if (sym < 0) { 881 lt = LT_IF; 882 } else { 883 *valp = (value[sym] != NULL); 884 lt = *valp ? LT_TRUE : LT_FALSE; 885 } 886 cp = skipsym(cp); 887 cp = skipcomment(cp); 888 if (defparen && *cp++ != ')') 889 return (LT_ERROR); 890 constexpr = false; 891 } else if (!endsym(*cp)) { 892 debug("eval%d symbol", ops - eval_ops); 893 sym = findsym(cp); 894 cp = skipsym(cp); 895 if (sym < 0) { 896 lt = LT_IF; 897 cp = skipargs(cp); 898 } else if (value[sym] == NULL) { 899 *valp = 0; 900 lt = LT_FALSE; 901 } else { 902 *valp = strtol(value[sym], &ep, 0); 903 if (*ep != '\0' || ep == value[sym]) 904 return (LT_ERROR); 905 lt = *valp ? LT_TRUE : LT_FALSE; 906 cp = skipargs(cp); 907 } 908 constexpr = false; 909 } else { 910 debug("eval%d bad expr", ops - eval_ops); 911 return (LT_ERROR); 912 } 913 914 *cpp = cp; 915 debug("eval%d = %d", ops - eval_ops, *valp); 916 return (lt); 917} 918 919/* 920 * Table-driven evaluation of binary operators. 921 */ 922static Linetype 923eval_table(const struct ops *ops, int *valp, const char **cpp) 924{ 925 const struct op *op; 926 const char *cp; 927 int val; 928 Linetype lt, rt; 929 930 debug("eval%d", ops - eval_ops); 931 cp = *cpp; 932 lt = ops->inner(ops+1, valp, &cp); 933 if (lt == LT_ERROR) 934 return (LT_ERROR); 935 for (;;) { 936 cp = skipcomment(cp); 937 for (op = ops->op; op->str != NULL; op++) 938 if (strncmp(cp, op->str, strlen(op->str)) == 0) 939 break; 940 if (op->str == NULL) 941 break; 942 cp += strlen(op->str); 943 debug("eval%d %s", ops - eval_ops, op->str); 944 rt = ops->inner(ops+1, &val, &cp); 945 if (rt == LT_ERROR) 946 return (LT_ERROR); 947 lt = op->fn(valp, lt, *valp, rt, val); 948 } 949 950 *cpp = cp; 951 debug("eval%d = %d", ops - eval_ops, *valp); 952 debug("eval%d lt = %s", ops - eval_ops, linetype_name[lt]); 953 return (lt); 954} 955 956/* 957 * Evaluate the expression on a #if or #elif line. If we can work out 958 * the result we return LT_TRUE or LT_FALSE accordingly, otherwise we 959 * return just a generic LT_IF. 960 */ 961static Linetype 962ifeval(const char **cpp) 963{ 964 int ret; 965 int val = 0; 966 967 debug("eval %s", *cpp); 968 constexpr = killconsts ? false : true; 969 ret = eval_table(eval_ops, &val, cpp); 970 debug("eval = %d", val); 971 return (constexpr ? LT_IF : ret == LT_ERROR ? LT_IF : ret); 972} 973 974/* 975 * Skip over comments, strings, and character literals and stop at the 976 * next character position that is not whitespace. Between calls we keep 977 * the comment state in the global variable incomment, and we also adjust 978 * the global variable linestate when we see a newline. 979 * XXX: doesn't cope with the buffer splitting inside a state transition. 980 */ 981static const char * 982skipcomment(const char *cp) 983{ 984 if (text || ignoring[depth]) { 985 for (; isspace((unsigned char)*cp); cp++) 986 if (*cp == '\n') 987 linestate = LS_START; 988 return (cp); 989 } 990 while (*cp != '\0') 991 /* don't reset to LS_START after a line continuation */ 992 if (strncmp(cp, "\\\r\n", 3) == 0) 993 cp += 3; 994 else if (strncmp(cp, "\\\n", 2) == 0) 995 cp += 2; 996 else switch (incomment) { 997 case NO_COMMENT: 998 if (strncmp(cp, "/\\\r\n", 4) == 0) { 999 incomment = STARTING_COMMENT; 1000 cp += 4; 1001 } else if (strncmp(cp, "/\\\n", 3) == 0) { 1002 incomment = STARTING_COMMENT; 1003 cp += 3; 1004 } else if (strncmp(cp, "/*", 2) == 0) { 1005 incomment = C_COMMENT; 1006 cp += 2; 1007 } else if (strncmp(cp, "//", 2) == 0) { 1008 incomment = CXX_COMMENT; 1009 cp += 2; 1010 } else if (strncmp(cp, "\'", 1) == 0) { 1011 incomment = CHAR_LITERAL; 1012 linestate = LS_DIRTY; 1013 cp += 1; 1014 } else if (strncmp(cp, "\"", 1) == 0) { 1015 incomment = STRING_LITERAL; 1016 linestate = LS_DIRTY; 1017 cp += 1; 1018 } else if (strncmp(cp, "\n", 1) == 0) { 1019 linestate = LS_START; 1020 cp += 1; 1021 } else if (strchr(" \r\t", *cp) != NULL) { 1022 cp += 1; 1023 } else 1024 return (cp); 1025 continue; 1026 case CXX_COMMENT: 1027 if (strncmp(cp, "\n", 1) == 0) { 1028 incomment = NO_COMMENT; 1029 linestate = LS_START; 1030 } 1031 cp += 1; 1032 continue; 1033 case CHAR_LITERAL: 1034 case STRING_LITERAL: 1035 if ((incomment == CHAR_LITERAL && cp[0] == '\'') || 1036 (incomment == STRING_LITERAL && cp[0] == '\"')) { 1037 incomment = NO_COMMENT; 1038 cp += 1; 1039 } else if (cp[0] == '\\') { 1040 if (cp[1] == '\0') 1041 cp += 1; 1042 else 1043 cp += 2; 1044 } else if (strncmp(cp, "\n", 1) == 0) { 1045 if (incomment == CHAR_LITERAL) 1046 error("unterminated char literal"); 1047 else 1048 error("unterminated string literal"); 1049 } else 1050 cp += 1; 1051 continue; 1052 case C_COMMENT: 1053 if (strncmp(cp, "*\\\r\n", 4) == 0) { 1054 incomment = FINISHING_COMMENT; 1055 cp += 4; 1056 } else if (strncmp(cp, "*\\\n", 3) == 0) { 1057 incomment = FINISHING_COMMENT; 1058 cp += 3; 1059 } else if (strncmp(cp, "*/", 2) == 0) { 1060 incomment = NO_COMMENT; 1061 cp += 2; 1062 } else 1063 cp += 1; 1064 continue; 1065 case STARTING_COMMENT: 1066 if (*cp == '*') { 1067 incomment = C_COMMENT; 1068 cp += 1; 1069 } else if (*cp == '/') { 1070 incomment = CXX_COMMENT; 1071 cp += 1; 1072 } else { 1073 incomment = NO_COMMENT; 1074 linestate = LS_DIRTY; 1075 } 1076 continue; 1077 case FINISHING_COMMENT: 1078 if (*cp == '/') { 1079 incomment = NO_COMMENT; 1080 cp += 1; 1081 } else 1082 incomment = C_COMMENT; 1083 continue; 1084 default: 1085 abort(); /* bug */ 1086 } 1087 return (cp); 1088} 1089 1090/* 1091 * Skip macro arguments. 1092 */ 1093static const char * 1094skipargs(const char *cp) 1095{ 1096 const char *ocp = cp; 1097 int level = 0; 1098 cp = skipcomment(cp); 1099 if (*cp != '(') 1100 return (cp); 1101 do { 1102 if (*cp == '(') 1103 level++; 1104 if (*cp == ')') 1105 level--; 1106 cp = skipcomment(cp+1); 1107 } while (level != 0 && *cp != '\0'); 1108 if (level == 0) 1109 return (cp); 1110 else 1111 /* Rewind and re-detect the syntax error later. */ 1112 return (ocp); 1113} 1114 1115/* 1116 * Skip over an identifier. 1117 */ 1118static const char * 1119skipsym(const char *cp) 1120{ 1121 while (!endsym(*cp)) 1122 ++cp; 1123 return (cp); 1124} 1125 1126/* 1127 * Look for the symbol in the symbol table. If it is found, we return 1128 * the symbol table index, else we return -1. 1129 */ 1130static int 1131findsym(const char *str) 1132{ 1133 const char *cp; 1134 int symind; 1135 1136 cp = skipsym(str); 1137 if (cp == str) 1138 return (-1); 1139 if (symlist) { 1140 if (symdepth && firstsym) 1141 printf("%s%3d", zerosyms ? "" : "\n", depth); 1142 firstsym = zerosyms = false; 1143 printf("%s%.*s%s", 1144 symdepth ? " " : "", 1145 (int)(cp-str), str, 1146 symdepth ? "" : "\n"); 1147 /* we don't care about the value of the symbol */ 1148 return (0); 1149 } 1150 for (symind = 0; symind < nsyms; ++symind) { 1151 if (strlcmp(symname[symind], str, cp-str) == 0) { 1152 debug("findsym %s %s", symname[symind], 1153 value[symind] ? value[symind] : ""); 1154 return (symind); 1155 } 1156 } 1157 return (-1); 1158} 1159 1160/* 1161 * Add a symbol to the symbol table. 1162 */ 1163static void 1164addsym(bool ignorethis, bool definethis, char *sym) 1165{ 1166 int symind; 1167 char *val; 1168 1169 symind = findsym(sym); 1170 if (symind < 0) { 1171 if (nsyms >= MAXSYMS) 1172 errx(2, "too many symbols"); 1173 symind = nsyms++; 1174 } 1175 symname[symind] = sym; 1176 ignore[symind] = ignorethis; 1177 val = sym + (skipsym(sym) - sym); 1178 if (definethis) { 1179 if (*val == '=') { 1180 value[symind] = val+1; 1181 *val = '\0'; 1182 } else if (*val == '\0') 1183 value[symind] = "1"; 1184 else 1185 usage(); 1186 } else { 1187 if (*val != '\0') 1188 usage(); 1189 value[symind] = NULL; 1190 } 1191 debug("addsym %s=%s", symname[symind], 1192 value[symind] ? value[symind] : "undef"); 1193} 1194 1195/* 1196 * Compare s with n characters of t. 1197 * The same as strncmp() except that it checks that s[n] == '\0'. 1198 */ 1199static int 1200strlcmp(const char *s, const char *t, size_t n) 1201{ 1202 while (n-- && *t != '\0') 1203 if (*s != *t) 1204 return ((unsigned char)*s - (unsigned char)*t); 1205 else 1206 ++s, ++t; 1207 return ((unsigned char)*s); 1208} 1209 1210/* 1211 * Diagnostics. 1212 */ 1213static void 1214debug(const char *msg, ...) 1215{ 1216 va_list ap; 1217 1218 if (debugging) { 1219 va_start(ap, msg); 1220 vwarnx(msg, ap); 1221 va_end(ap); 1222 } 1223} 1224 1225static void 1226error(const char *msg) 1227{ 1228 if (depth == 0) 1229 warnx("%s: %d: %s", filename, linenum, msg); 1230 else 1231 warnx("%s: %d: %s (#if line %d depth %d)", 1232 filename, linenum, msg, stifline[depth], depth); 1233 closeout(); 1234 errx(2, "output may be truncated"); 1235} 1236