1 /*
2 * Copyright (c) 2002 - 2020 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 RAW_STRING_LITERAL /* inside R"()" */
119 } Comment_state;
120
121 static char const * const comment_name[] = {
122 "NO", "C", "CXX", "STARTING", "FINISHING", "CHAR", "STRING"
123 };
124
125 /* state of preprocessor line parser */
126 typedef enum {
127 LS_START, /* only space and comments on this line */
128 LS_HASH, /* only space, comments, and a hash */
129 LS_DIRTY /* this line can't be a preprocessor line */
130 } Line_state;
131
132 static char const * const linestate_name[] = {
133 "START", "HASH", "DIRTY"
134 };
135
136 /*
137 * Minimum translation limits from ISO/IEC 9899:1999 5.2.4.1
138 */
139 #define MAXDEPTH 64 /* maximum #if nesting */
140 #define MAXLINE 4096 /* maximum length of line */
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 * C17/18 allow 63 characters per macro name, but up to 127 arbitrarily large
150 * parameters.
151 */
152 struct macro {
153 RB_ENTRY(macro) entry;
154 const char *name;
155 const char *value;
156 bool ignore; /* -iDsym or -iUsym */
157 };
158
159 static int
macro_cmp(struct macro * a,struct macro * b)160 macro_cmp(struct macro *a, struct macro *b)
161 {
162 return (strcmp(a->name, b->name));
163 }
164
165 static RB_HEAD(MACROMAP, macro) macro_tree = RB_INITIALIZER(¯o_tree);
166 RB_GENERATE_STATIC(MACROMAP, macro, entry, macro_cmp);
167
168 /*
169 * Globals.
170 */
171
172 static bool compblank; /* -B: compress blank lines */
173 static bool lnblank; /* -b: blank deleted lines */
174 static bool complement; /* -c: do the complement */
175 static bool debugging; /* -d: debugging reports */
176 static bool inplace; /* -m: modify in place */
177 static bool iocccok; /* -e: fewer IOCCC errors */
178 static bool strictlogic; /* -K: keep ambiguous #ifs */
179 static bool killconsts; /* -k: eval constant #ifs */
180 static bool lnnum; /* -n: add #line directives */
181 static bool symlist; /* -s: output symbol list */
182 static bool symdepth; /* -S: output symbol depth */
183 static bool text; /* -t: this is a text file */
184
185 static FILE *input; /* input file pointer */
186 static const char *filename; /* input file name */
187 static int linenum; /* current line number */
188 static const char *linefile; /* file name for #line */
189 static FILE *output; /* output file pointer */
190 static const char *ofilename; /* output file name */
191 static const char *backext; /* backup extension */
192 static char *tempname; /* avoid splatting input */
193
194 static char tline[MAXLINE+EDITSLOP];/* input buffer plus space */
195 static char *keyword; /* used for editing #elif's */
196
197 /*
198 * When processing a file, the output's newline style will match the
199 * input's, and unifdef correctly handles CRLF or LF endings whatever
200 * the platform's native style. The stdio streams are opened in binary
201 * mode to accommodate platforms whose native newline style is CRLF.
202 * When the output isn't a processed input file (when it is error /
203 * debug / diagnostic messages) then unifdef uses native line endings.
204 */
205
206 static const char *newline; /* input file format */
207 static const char newline_unix[] = "\n";
208 static const char newline_crlf[] = "\r\n";
209
210 static Comment_state incomment; /* comment parser state */
211 static Line_state linestate; /* #if line parser state */
212 static Ifstate ifstate[MAXDEPTH]; /* #if processor state */
213 static bool ignoring[MAXDEPTH]; /* ignore comments state */
214 static int stifline[MAXDEPTH]; /* start of current #if */
215 static int depth; /* current #if nesting */
216 static int delcount; /* count of deleted lines */
217 static unsigned blankcount; /* count of blank lines */
218 static unsigned blankmax; /* maximum recent blankcount */
219 static bool constexpr; /* constant #if expression */
220 static bool zerosyms; /* to format symdepth output */
221 static bool firstsym; /* ditto */
222
223 static int exitmode; /* exit status mode */
224 static int exitstat; /* program exit status */
225 static bool altered; /* was this file modified? */
226
227 static void addsym1(bool, bool, char *);
228 static void addsym2(bool, const char *, const char *);
229 static char *astrcat(const char *, const char *);
230 static void cleantemp(void);
231 static void closeio(void);
232 static void debug(const char *, ...);
233 static void debugsym(const char *, const struct macro *);
234 static bool defundef(void);
235 static void defundefile(const char *);
236 static void done(void);
237 static void error(const char *);
238 static struct macro *findsym(const char **);
239 static void flushline(bool);
240 static void hashline(void);
241 static void help(void);
242 static Linetype ifeval(const char **);
243 static void ignoreoff(void);
244 static void ignoreon(void);
245 static void indirectsym(void);
246 static void keywordedit(const char *);
247 static const char *matchsym(const char *, const char *);
248 static void nest(void);
249 static Linetype parseline(void);
250 static void process(void);
251 static void processinout(const char *, const char *);
252 static const char *skipargs(const char *);
253 static const char *skipcomment(const char *);
254 static const char *skiphash(void);
255 static const char *skipline(const char *);
256 static const char *skipsym(const char *);
257 static void state(Ifstate);
258 static void unnest(void);
259 static void usage(void);
260 static void version(void);
261 static const char *xstrdup(const char *, const char *);
262
263 #define endsym(c) (!isalnum((unsigned char)c) && c != '_')
264
265 /*
266 * The main program.
267 */
268 int
main(int argc,char * argv[])269 main(int argc, char *argv[])
270 {
271 int opt;
272
273 while ((opt = getopt(argc, argv, "i:D:U:f:I:M:o:x:bBcdehKklmnsStV")) != -1)
274 switch (opt) {
275 case 'i': /* treat stuff controlled by these symbols as text */
276 /*
277 * For strict backwards-compatibility the U or D
278 * should be immediately after the -i but it doesn't
279 * matter much if we relax that requirement.
280 */
281 opt = *optarg++;
282 if (opt == 'D')
283 addsym1(true, true, optarg);
284 else if (opt == 'U')
285 addsym1(true, false, optarg);
286 else
287 usage();
288 break;
289 case 'D': /* define a symbol */
290 addsym1(false, true, optarg);
291 break;
292 case 'U': /* undef a symbol */
293 addsym1(false, false, optarg);
294 break;
295 case 'I': /* no-op for compatibility with cpp */
296 break;
297 case 'b': /* blank deleted lines instead of omitting them */
298 case 'l': /* backwards compatibility */
299 lnblank = true;
300 break;
301 case 'B': /* compress blank lines around removed section */
302 compblank = true;
303 break;
304 case 'c': /* treat -D as -U and vice versa */
305 complement = true;
306 break;
307 case 'd':
308 debugging = true;
309 break;
310 case 'e': /* fewer errors from dodgy lines */
311 iocccok = true;
312 break;
313 case 'f': /* definitions file */
314 defundefile(optarg);
315 break;
316 case 'h':
317 help();
318 break;
319 case 'K': /* keep ambiguous #ifs */
320 strictlogic = true;
321 break;
322 case 'k': /* process constant #ifs */
323 killconsts = true;
324 break;
325 case 'm': /* modify in place */
326 inplace = true;
327 break;
328 case 'M': /* modify in place and keep backup */
329 inplace = true;
330 if (strlen(optarg) > 0)
331 backext = optarg;
332 break;
333 case 'n': /* add #line directive after deleted lines */
334 lnnum = true;
335 break;
336 case 'o': /* output to a file */
337 ofilename = optarg;
338 break;
339 case 's': /* only output list of symbols that control #ifs */
340 symlist = true;
341 break;
342 case 'S': /* list symbols with their nesting depth */
343 symlist = symdepth = true;
344 break;
345 case 't': /* don't parse C comments */
346 text = true;
347 break;
348 case 'V':
349 version();
350 break;
351 case 'x':
352 exitmode = atoi(optarg);
353 if(exitmode < 0 || exitmode > 2)
354 usage();
355 break;
356 default:
357 usage();
358 }
359 argc -= optind;
360 argv += optind;
361 if (compblank && lnblank)
362 errx(2, "-B and -b are mutually exclusive");
363 if (symlist && (ofilename != NULL || inplace || argc > 1))
364 errx(2, "-s only works with one input file");
365 if (argc > 1 && ofilename != NULL)
366 errx(2, "-o cannot be used with multiple input files");
367 if (argc > 1 && !inplace)
368 errx(2, "multiple input files require -m or -M");
369 if (argc == 0 && inplace)
370 errx(2, "-m requires an input file");
371 if (argc == 0)
372 argc = 1;
373 if (argc == 1 && !inplace && ofilename == NULL)
374 ofilename = "-";
375 indirectsym();
376
377 atexit(cleantemp);
378 if (ofilename != NULL)
379 processinout(*argv, ofilename);
380 else while (argc-- > 0) {
381 processinout(*argv, *argv);
382 argv++;
383 }
384 switch(exitmode) {
385 case(0): exit(exitstat);
386 case(1): exit(!exitstat);
387 case(2): exit(0);
388 default: abort(); /* bug */
389 }
390 }
391
392 /*
393 * File logistics.
394 */
395 static void
processinout(const char * ifn,const char * ofn)396 processinout(const char *ifn, const char *ofn)
397 {
398 struct stat st;
399
400 if (ifn == NULL || strcmp(ifn, "-") == 0) {
401 filename = "[stdin]";
402 linefile = NULL;
403 input = fbinmode(stdin);
404 } else {
405 filename = ifn;
406 linefile = ifn;
407 input = fopen(ifn, "rb");
408 if (input == NULL)
409 err(2, "can't open %s", ifn);
410 }
411 if (strcmp(ofn, "-") == 0) {
412 output = fbinmode(stdout);
413 process();
414 return;
415 }
416 if (stat(ofn, &st) < 0) {
417 output = fopen(ofn, "wb");
418 if (output == NULL)
419 err(2, "can't create %s", ofn);
420 process();
421 return;
422 }
423
424 tempname = astrcat(ofn, ".XXXXXX");
425 output = mktempmode(tempname, st.st_mode);
426 if (output == NULL)
427 err(2, "can't create %s", tempname);
428
429 process();
430
431 if (backext != NULL) {
432 char *backname = astrcat(ofn, backext);
433 if (rename(ofn, backname) < 0)
434 err(2, "can't rename \"%s\" to \"%s\"", ofn, backname);
435 free(backname);
436 }
437 /* leave file unmodified if unifdef made no changes */
438 if (!altered && backext == NULL) {
439 if (remove(tempname) < 0)
440 warn("can't remove \"%s\"", tempname);
441 } else if (replace(tempname, ofn) < 0)
442 err(2, "can't rename \"%s\" to \"%s\"", tempname, ofn);
443 free(tempname);
444 tempname = NULL;
445 }
446
447 /*
448 * For cleaning up if there is an error.
449 */
450 static void
cleantemp(void)451 cleantemp(void)
452 {
453 if (tempname != NULL)
454 remove(tempname);
455 }
456
457 /*
458 * Self-identification functions.
459 */
460
461 static void
version(void)462 version(void)
463 {
464 const char *c = copyright;
465 for (;;) {
466 while (*++c != '$')
467 if (*c == '\0')
468 exit(0);
469 while (*++c != '$')
470 putc(*c, stderr);
471 putc('\n', stderr);
472 }
473 }
474
475 static void
synopsis(FILE * fp)476 synopsis(FILE *fp)
477 {
478 fprintf(fp,
479 "usage: unifdef [-bBcdehKkmnsStV] [-x{012}] [-Mext] [-opath] \\\n"
480 " [-[i]Dsym[=val]] [-[i]Usym] [-fpath] ... [file] ...\n");
481 }
482
483 static void
usage(void)484 usage(void)
485 {
486 synopsis(stderr);
487 exit(2);
488 }
489
490 static void
help(void)491 help(void)
492 {
493 synopsis(stdout);
494 printf(
495 " -Dsym=val define preprocessor symbol with given value\n"
496 " -Dsym define preprocessor symbol with value 1\n"
497 " -Usym preprocessor symbol is undefined\n"
498 " -iDsym=val \\ ignore C strings and comments\n"
499 " -iDsym ) in sections controlled by these\n"
500 " -iUsym / preprocessor symbols\n"
501 " -fpath file containing #define and #undef directives\n"
502 " -b blank lines instead of deleting them\n"
503 " -B compress blank lines around deleted section\n"
504 " -c complement (invert) keep vs. delete\n"
505 " -d debugging mode\n"
506 " -e ignore multiline preprocessor directives\n"
507 " -h print help\n"
508 " -Ipath extra include file path (ignored)\n"
509 " -K disable && and || short-circuiting\n"
510 " -k process constant #if expressions\n"
511 " -Mext modify in place and keep backups\n"
512 " -m modify input files in place\n"
513 " -n add #line directives to output\n"
514 " -opath output file name\n"
515 " -S list #if control symbols with nesting\n"
516 " -s list #if control symbols\n"
517 " -t ignore C strings and comments\n"
518 " -V print version\n"
519 " -x{012} exit status mode\n"
520 );
521 exit(0);
522 }
523
524 /*
525 * A state transition function alters the global #if processing state
526 * in a particular way. The table below is indexed by the current
527 * processing state and the type of the current line.
528 *
529 * Nesting is handled by keeping a stack of states; some transition
530 * functions increase or decrease the depth. They also maintain the
531 * ignore state on a stack. In some complicated cases they have to
532 * alter the preprocessor directive, as follows.
533 *
534 * When we have processed a group that starts off with a known-false
535 * #if/#elif sequence (which has therefore been deleted) followed by a
536 * #elif that we don't understand and therefore must keep, we edit the
537 * latter into a #if to keep the nesting correct. We use memcpy() to
538 * overwrite the 4 byte token "elif" with "if " without a '\0' byte.
539 *
540 * When we find a true #elif in a group, the following block will
541 * always be kept and the rest of the sequence after the next #elif or
542 * #else will be discarded. We edit the #elif into a #else and the
543 * following directive to #endif since this has the desired behaviour.
544 *
545 * "Dodgy" directives are split across multiple lines, the most common
546 * example being a multi-line comment hanging off the right of the
547 * directive. We can handle them correctly only if there is no change
548 * from printing to dropping (or vice versa) caused by that directive.
549 * If the directive is the first of a group we have a choice between
550 * failing with an error, or passing it through unchanged instead of
551 * evaluating it. The latter is not the default to avoid questions from
552 * users about unifdef unexpectedly leaving behind preprocessor directives.
553 */
554 typedef void state_fn(void);
555
556 /* report an error */
Eelif(void)557 static void Eelif (void) { error("Inappropriate #elif"); }
Eelse(void)558 static void Eelse (void) { error("Inappropriate #else"); }
Eendif(void)559 static void Eendif(void) { error("Inappropriate #endif"); }
Eeof(void)560 static void Eeof (void) { error("Premature EOF"); }
Eioccc(void)561 static void Eioccc(void) { error("Obfuscated preprocessor control line"); }
562 /* plain line handling */
print(void)563 static void print (void) { flushline(true); }
drop(void)564 static void drop (void) { flushline(false); }
565 /* output lacks group's start line */
Strue(void)566 static void Strue (void) { drop(); ignoreoff(); state(IS_TRUE_PREFIX); }
Sfalse(void)567 static void Sfalse(void) { drop(); ignoreoff(); state(IS_FALSE_PREFIX); }
Selse(void)568 static void Selse (void) { drop(); state(IS_TRUE_ELSE); }
569 /* print/pass this block */
Pelif(void)570 static void Pelif (void) { print(); ignoreoff(); state(IS_PASS_MIDDLE); }
Pelse(void)571 static void Pelse (void) { print(); state(IS_PASS_ELSE); }
Pendif(void)572 static void Pendif(void) { print(); unnest(); }
573 /* discard this block */
Dfalse(void)574 static void Dfalse(void) { drop(); ignoreoff(); state(IS_FALSE_TRAILER); }
Delif(void)575 static void Delif (void) { drop(); ignoreoff(); state(IS_FALSE_MIDDLE); }
Delse(void)576 static void Delse (void) { drop(); state(IS_FALSE_ELSE); }
Dendif(void)577 static void Dendif(void) { drop(); unnest(); }
578 /* first line of group */
Fdrop(void)579 static void Fdrop (void) { nest(); Dfalse(); }
Fpass(void)580 static void Fpass (void) { nest(); Pelif(); }
Ftrue(void)581 static void Ftrue (void) { nest(); Strue(); }
Ffalse(void)582 static void Ffalse(void) { nest(); Sfalse(); }
583 /* variable pedantry for obfuscated lines */
Oiffy(void)584 static void Oiffy (void) { if (!iocccok) Eioccc(); Fpass(); ignoreon(); }
Oif(void)585 static void Oif (void) { if (!iocccok) Eioccc(); Fpass(); }
Oelif(void)586 static void Oelif (void) { if (!iocccok) Eioccc(); Pelif(); }
587 /* ignore comments in this block */
Idrop(void)588 static void Idrop (void) { Fdrop(); ignoreon(); }
Itrue(void)589 static void Itrue (void) { Ftrue(); ignoreon(); }
Ifalse(void)590 static void Ifalse(void) { Ffalse(); ignoreon(); }
591 /* modify this line */
Mpass(void)592 static void Mpass (void) { memcpy(keyword, "if ", 4); Pelif(); }
Mtrue(void)593 static void Mtrue (void) { keywordedit("else"); state(IS_TRUE_MIDDLE); }
Melif(void)594 static void Melif (void) { keywordedit("endif"); state(IS_FALSE_TRAILER); }
Melse(void)595 static void Melse (void) { keywordedit("endif"); state(IS_FALSE_ELSE); }
596
597 static state_fn * const trans_table[IS_COUNT][LT_COUNT] = {
598 /* IS_OUTSIDE */
599 { Itrue, Ifalse,Fpass, Ftrue, Ffalse,Eelif, Eelif, Eelif, Eelse, Eendif,
600 Oiffy, Oiffy, Fpass, Oif, Oif, Eelif, Eelif, Eelif, Eelse, Eendif,
601 print, done, abort },
602 /* IS_FALSE_PREFIX */
603 { Idrop, Idrop, Fdrop, Fdrop, Fdrop, Mpass, Strue, Sfalse,Selse, Dendif,
604 Idrop, Idrop, Fdrop, Fdrop, Fdrop, Mpass, Eioccc,Eioccc,Eioccc,Eioccc,
605 drop, Eeof, abort },
606 /* IS_TRUE_PREFIX */
607 { Itrue, Ifalse,Fpass, Ftrue, Ffalse,Dfalse,Dfalse,Dfalse,Delse, Dendif,
608 Oiffy, Oiffy, Fpass, Oif, Oif, Eioccc,Eioccc,Eioccc,Eioccc,Eioccc,
609 print, Eeof, abort },
610 /* IS_PASS_MIDDLE */
611 { Itrue, Ifalse,Fpass, Ftrue, Ffalse,Pelif, Mtrue, Delif, Pelse, Pendif,
612 Oiffy, Oiffy, Fpass, Oif, Oif, Pelif, Oelif, Oelif, Pelse, Pendif,
613 print, Eeof, abort },
614 /* IS_FALSE_MIDDLE */
615 { Idrop, Idrop, Fdrop, Fdrop, Fdrop, Pelif, Mtrue, Delif, Pelse, Pendif,
616 Idrop, Idrop, Fdrop, Fdrop, Fdrop, Eioccc,Eioccc,Eioccc,Eioccc,Eioccc,
617 drop, Eeof, abort },
618 /* IS_TRUE_MIDDLE */
619 { Itrue, Ifalse,Fpass, Ftrue, Ffalse,Melif, Melif, Melif, Melse, Pendif,
620 Oiffy, Oiffy, Fpass, Oif, Oif, Eioccc,Eioccc,Eioccc,Eioccc,Pendif,
621 print, Eeof, abort },
622 /* IS_PASS_ELSE */
623 { Itrue, Ifalse,Fpass, Ftrue, Ffalse,Eelif, Eelif, Eelif, Eelse, Pendif,
624 Oiffy, Oiffy, Fpass, Oif, Oif, Eelif, Eelif, Eelif, Eelse, Pendif,
625 print, Eeof, abort },
626 /* IS_FALSE_ELSE */
627 { Idrop, Idrop, Fdrop, Fdrop, Fdrop, Eelif, Eelif, Eelif, Eelse, Dendif,
628 Idrop, Idrop, Fdrop, Fdrop, Fdrop, Eelif, Eelif, Eelif, Eelse, Eioccc,
629 drop, Eeof, abort },
630 /* IS_TRUE_ELSE */
631 { Itrue, Ifalse,Fpass, Ftrue, Ffalse,Eelif, Eelif, Eelif, Eelse, Dendif,
632 Oiffy, Oiffy, Fpass, Oif, Oif, Eelif, Eelif, Eelif, Eelse, Eioccc,
633 print, Eeof, abort },
634 /* IS_FALSE_TRAILER */
635 { Idrop, Idrop, Fdrop, Fdrop, Fdrop, Dfalse,Dfalse,Dfalse,Delse, Dendif,
636 Idrop, Idrop, Fdrop, Fdrop, Fdrop, Dfalse,Dfalse,Dfalse,Delse, Eioccc,
637 drop, Eeof, abort }
638 /*TRUEI FALSEI IF TRUE FALSE ELIF ELTRUE ELFALSE ELSE ENDIF
639 TRUEI FALSEI IF TRUE FALSE ELIF ELTRUE ELFALSE ELSE ENDIF (DODGY)
640 PLAIN EOF ERROR */
641 };
642
643 /*
644 * State machine utility functions
645 */
646 static void
ignoreoff(void)647 ignoreoff(void)
648 {
649 if (depth == 0)
650 abort(); /* bug */
651 ignoring[depth] = ignoring[depth-1];
652 }
653 static void
ignoreon(void)654 ignoreon(void)
655 {
656 ignoring[depth] = true;
657 }
658 static void
keywordedit(const char * replacement)659 keywordedit(const char *replacement)
660 {
661 snprintf(keyword, tline + sizeof(tline) - keyword,
662 "%s%s", replacement, newline);
663 altered = true;
664 print();
665 }
666 static void
nest(void)667 nest(void)
668 {
669 if (depth > MAXDEPTH-1)
670 abort(); /* bug */
671 if (depth == MAXDEPTH-1)
672 error("Too many levels of nesting");
673 depth += 1;
674 stifline[depth] = linenum;
675 }
676 static void
unnest(void)677 unnest(void)
678 {
679 if (depth == 0)
680 abort(); /* bug */
681 depth -= 1;
682 }
683 static void
state(Ifstate is)684 state(Ifstate is)
685 {
686 ifstate[depth] = is;
687 }
688
689 /*
690 * The last state transition function. When this is called,
691 * lineval == LT_EOF, so the process() loop will terminate.
692 */
693 static void
done(void)694 done(void)
695 {
696 if (incomment)
697 error("EOF in comment");
698 closeio();
699 }
700
701 /*
702 * Write a line to the output or not, according to command line options.
703 * If writing fails, closeio() will print the error and exit.
704 */
705 static void
flushline(bool keep)706 flushline(bool keep)
707 {
708 if (symlist)
709 return;
710 if (keep ^ complement) {
711 bool blankline = tline[strspn(tline, " \t\r\n")] == '\0';
712 if (blankline && compblank && blankcount != blankmax) {
713 delcount += 1;
714 blankcount += 1;
715 } else {
716 if (lnnum && delcount > 0)
717 hashline();
718 if (fputs(tline, output) == EOF)
719 closeio();
720 delcount = 0;
721 blankmax = blankcount = blankline ? blankcount + 1 : 0;
722 }
723 } else {
724 if (lnblank && fputs(newline, output) == EOF)
725 closeio();
726 altered = true;
727 delcount += 1;
728 blankcount = 0;
729 }
730 if (debugging && fflush(output) == EOF)
731 closeio();
732 }
733
734 /*
735 * Format of #line directives depends on whether we know the input filename.
736 */
737 static void
hashline(void)738 hashline(void)
739 {
740 int e;
741
742 if (linefile == NULL)
743 e = fprintf(output, "#line %d%s", linenum, newline);
744 else
745 e = fprintf(output, "#line %d \"%s\"%s",
746 linenum, linefile, newline);
747 if (e < 0)
748 closeio();
749 }
750
751 /*
752 * Flush the output and handle errors.
753 */
754 static void
closeio(void)755 closeio(void)
756 {
757 /* Tidy up after findsym(). */
758 if (symdepth && !zerosyms)
759 printf("\n");
760 if (output != NULL && (ferror(output) || fclose(output) == EOF))
761 err(2, "%s: can't write to output", filename);
762 fclose(input);
763 }
764
765 /*
766 * The driver for the state machine.
767 */
768 static void
process(void)769 process(void)
770 {
771 Linetype lineval = LT_PLAIN;
772 /* When compressing blank lines, act as if the file
773 is preceded by a large number of blank lines. */
774 blankmax = blankcount = 1000;
775 zerosyms = true;
776 newline = NULL;
777 linenum = 0;
778 altered = false;
779 while (lineval != LT_EOF) {
780 lineval = parseline();
781 trans_table[ifstate[depth]][lineval]();
782 debug("process line %d %s -> %s depth %d",
783 linenum, linetype_name[lineval],
784 ifstate_name[ifstate[depth]], depth);
785 }
786 exitstat |= altered;
787 }
788
789 /*
790 * Parse a line and determine its type. We keep the preprocessor line
791 * parser state between calls in the global variable linestate, with
792 * help from skipcomment().
793 */
794 static Linetype
parseline(void)795 parseline(void)
796 {
797 const char *cp;
798 struct macro *cursym;
799 Linetype retval;
800 Comment_state wascomment;
801
802 wascomment = incomment;
803 cp = skiphash();
804 if (cp == NULL)
805 return (LT_EOF);
806 if (newline == NULL) {
807 if (strrchr(tline, '\n') == strrchr(tline, '\r') + 1)
808 newline = newline_crlf;
809 else
810 newline = newline_unix;
811 }
812 if (*cp == '\0') {
813 retval = LT_PLAIN;
814 goto done;
815 }
816 keyword = tline + (cp - tline);
817 if ((cp = matchsym("ifdef", keyword)) != NULL ||
818 (cp = matchsym("ifndef", keyword)) != NULL) {
819 cp = skipcomment(cp);
820 if ((cursym = findsym(&cp)) == NULL)
821 retval = LT_IF;
822 else {
823 retval = (keyword[2] == 'n')
824 ? LT_FALSE : LT_TRUE;
825 if (cursym->value == NULL)
826 retval = (retval == LT_TRUE)
827 ? LT_FALSE : LT_TRUE;
828 if (cursym->ignore)
829 retval = (retval == LT_TRUE)
830 ? LT_TRUEI : LT_FALSEI;
831 }
832 } else if ((cp = matchsym("if", keyword)) != NULL)
833 retval = ifeval(&cp);
834 else if ((cp = matchsym("elif", keyword)) != NULL)
835 retval = linetype_if2elif(ifeval(&cp));
836 else if ((cp = matchsym("else", keyword)) != NULL)
837 retval = LT_ELSE;
838 else if ((cp = matchsym("endif", keyword)) != NULL)
839 retval = LT_ENDIF;
840 else {
841 cp = skipsym(keyword);
842 /* no way can we deal with a continuation inside a keyword */
843 if (strncmp(cp, "\\\r\n", 3) == 0 ||
844 strncmp(cp, "\\\n", 2) == 0)
845 Eioccc();
846 cp = skipline(cp);
847 retval = LT_PLAIN;
848 goto done;
849 }
850 cp = skipcomment(cp);
851 if (*cp != '\0') {
852 cp = skipline(cp);
853 if (retval == LT_TRUE || retval == LT_FALSE ||
854 retval == LT_TRUEI || retval == LT_FALSEI)
855 retval = LT_IF;
856 if (retval == LT_ELTRUE || retval == LT_ELFALSE)
857 retval = LT_ELIF;
858 }
859 /* the following can happen if the last line of the file lacks a
860 newline or if there is too much whitespace in a directive */
861 if (linestate == LS_HASH) {
862 long len = cp - tline;
863 if (fgets(tline + len, MAXLINE - len, input) == NULL) {
864 if (ferror(input))
865 err(2, "can't read %s", filename);
866 debug("parser insert newline at EOF", linenum);
867 strcpy(tline + len, newline);
868 cp += strlen(newline);
869 linestate = LS_START;
870 } else {
871 debug("parser concatenate dangling whitespace");
872 ++linenum;
873 cp = skipcomment(cp);
874 }
875 }
876 if (retval != LT_PLAIN && (wascomment || linestate != LS_START)) {
877 retval = linetype_2dodgy(retval);
878 linestate = LS_DIRTY;
879 }
880 done:
881 debug("parser line %d state %s comment %s line", linenum,
882 comment_name[incomment], linestate_name[linestate]);
883 return (retval);
884 }
885
886 /*
887 * These are the binary operators that are supported by the expression
888 * evaluator.
889 */
op_strict(long * p,long v,Linetype at,Linetype bt)890 static Linetype op_strict(long *p, long v, Linetype at, Linetype bt) {
891 if(at == LT_IF || bt == LT_IF) return (LT_IF);
892 return (*p = v, v ? LT_TRUE : LT_FALSE);
893 }
op_lt(long * p,Linetype at,long a,Linetype bt,long b)894 static Linetype op_lt(long *p, Linetype at, long a, Linetype bt, long b) {
895 return op_strict(p, a < b, at, bt);
896 }
op_gt(long * p,Linetype at,long a,Linetype bt,long b)897 static Linetype op_gt(long *p, Linetype at, long a, Linetype bt, long b) {
898 return op_strict(p, a > b, at, bt);
899 }
op_le(long * p,Linetype at,long a,Linetype bt,long b)900 static Linetype op_le(long *p, Linetype at, long a, Linetype bt, long b) {
901 return op_strict(p, a <= b, at, bt);
902 }
op_ge(long * p,Linetype at,long a,Linetype bt,long b)903 static Linetype op_ge(long *p, Linetype at, long a, Linetype bt, long b) {
904 return op_strict(p, a >= b, at, bt);
905 }
op_eq(long * p,Linetype at,long a,Linetype bt,long b)906 static Linetype op_eq(long *p, Linetype at, long a, Linetype bt, long b) {
907 return op_strict(p, a == b, at, bt);
908 }
op_ne(long * p,Linetype at,long a,Linetype bt,long b)909 static Linetype op_ne(long *p, Linetype at, long a, Linetype bt, long b) {
910 return op_strict(p, a != b, at, bt);
911 }
op_or(long * p,Linetype at,long a,Linetype bt,long b)912 static Linetype op_or(long *p, Linetype at, long a, Linetype bt, long b) {
913 if (!strictlogic && (at == LT_TRUE || bt == LT_TRUE))
914 return (*p = 1, LT_TRUE);
915 return op_strict(p, a || b, at, bt);
916 }
op_and(long * p,Linetype at,long a,Linetype bt,long b)917 static Linetype op_and(long *p, Linetype at, long a, Linetype bt, long b) {
918 if (!strictlogic && (at == LT_FALSE || bt == LT_FALSE))
919 return (*p = 0, LT_FALSE);
920 return op_strict(p, a && b, at, bt);
921 }
op_blsh(long * p,Linetype at,long a,Linetype bt,long b)922 static Linetype op_blsh(long *p, Linetype at, long a, Linetype bt, long b) {
923 return op_strict(p, a << b, at, bt);
924 }
op_brsh(long * p,Linetype at,long a,Linetype bt,long b)925 static Linetype op_brsh(long *p, Linetype at, long a, Linetype bt, long b) {
926 return op_strict(p, a >> b, at, bt);
927 }
op_add(long * p,Linetype at,long a,Linetype bt,long b)928 static Linetype op_add(long *p, Linetype at, long a, Linetype bt, long b) {
929 return op_strict(p, a + b, at, bt);
930 }
op_sub(long * p,Linetype at,long a,Linetype bt,long b)931 static Linetype op_sub(long *p, Linetype at, long a, Linetype bt, long b) {
932 return op_strict(p, a - b, at, bt);
933 }
op_mul(long * p,Linetype at,long a,Linetype bt,long b)934 static Linetype op_mul(long *p, Linetype at, long a, Linetype bt, long b) {
935 return op_strict(p, a * b, at, bt);
936 }
op_div(long * p,Linetype at,long a,Linetype bt,long b)937 static Linetype op_div(long *p, Linetype at, long a, Linetype bt, long b) {
938 if (bt != LT_TRUE) {
939 debug("eval division by zero");
940 return (LT_ERROR);
941 }
942 return op_strict(p, a / b, at, bt);
943 }
op_mod(long * p,Linetype at,long a,Linetype bt,long b)944 static Linetype op_mod(long *p, Linetype at, long a, Linetype bt, long b) {
945 return op_strict(p, a % b, at, bt);
946 }
op_bor(long * p,Linetype at,long a,Linetype bt,long b)947 static Linetype op_bor(long *p, Linetype at, long a, Linetype bt, long b) {
948 return op_strict(p, a | b, at, bt);
949 }
op_bxor(long * p,Linetype at,long a,Linetype bt,long b)950 static Linetype op_bxor(long *p, Linetype at, long a, Linetype bt, long b) {
951 return op_strict(p, a ^ b, at, bt);
952 }
op_band(long * p,Linetype at,long a,Linetype bt,long b)953 static Linetype op_band(long *p, Linetype at, long a, Linetype bt, long b) {
954 return op_strict(p, a & b, at, bt);
955 }
956
957 /*
958 * An evaluation function takes three arguments, as follows: (1) a pointer to
959 * an element of the precedence table which lists the operators at the current
960 * level of precedence; (2) a pointer to an integer which will receive the
961 * value of the expression; and (3) a pointer to a char* that points to the
962 * expression to be evaluated and that is updated to the end of the expression
963 * when evaluation is complete. The function returns LT_FALSE if the value of
964 * the expression is zero, LT_TRUE if it is non-zero, LT_IF if the expression
965 * depends on an unknown symbol, or LT_ERROR if there is a parse failure.
966 */
967 struct ops;
968
969 typedef Linetype eval_fn(const struct ops *, long *, const char **);
970
971 static eval_fn eval_table, eval_unary;
972
973 /*
974 * The precedence table. Expressions involving binary operators are evaluated
975 * in a table-driven way by eval_table. When it evaluates a subexpression it
976 * calls the inner function with its first argument pointing to the next
977 * element of the table. Innermost expressions have special non-table-driven
978 * handling.
979 *
980 * The stop characters help with lexical analysis: an operator is not
981 * recognized if it is followed by one of the stop characters because
982 * that would make it a different operator.
983 */
984 struct op {
985 const char *str;
986 Linetype (*fn)(long *, Linetype, long, Linetype, long);
987 const char *stop;
988 };
989 struct ops {
990 eval_fn *inner;
991 struct op op[5];
992 };
993 static const struct ops eval_ops[] = {
994 { eval_table, { { "||", op_or, NULL } } },
995 { eval_table, { { "&&", op_and, NULL } } },
996 { eval_table, { { "|", op_bor, "|" } } },
997 { eval_table, { { "^", op_bxor, NULL } } },
998 { eval_table, { { "&", op_band, "&" } } },
999 { eval_table, { { "==", op_eq, NULL },
1000 { "!=", op_ne, NULL } } },
1001 { eval_table, { { "<=", op_le, NULL },
1002 { ">=", op_ge, NULL },
1003 { "<", op_lt, "<=" },
1004 { ">", op_gt, ">=" } } },
1005 { eval_table, { { "<<", op_blsh, NULL },
1006 { ">>", op_brsh, NULL } } },
1007 { eval_table, { { "+", op_add, NULL },
1008 { "-", op_sub, NULL } } },
1009 { eval_unary, { { "*", op_mul, NULL },
1010 { "/", op_div, NULL },
1011 { "%", op_mod, NULL } } },
1012 };
1013
1014 /* Current operator precedence level */
prec(const struct ops * ops)1015 static long prec(const struct ops *ops)
1016 {
1017 return (ops - eval_ops);
1018 }
1019
1020 /*
1021 * Function for evaluating the innermost parts of expressions,
1022 * viz. !expr (expr) number defined(symbol) symbol
1023 * We reset the constexpr flag in the last two cases.
1024 */
1025 static Linetype
eval_unary(const struct ops * ops,long * valp,const char ** cpp)1026 eval_unary(const struct ops *ops, long *valp, const char **cpp)
1027 {
1028 const char *cp;
1029 char *ep;
1030 struct macro *sym;
1031 bool defparen;
1032 Linetype lt;
1033
1034 cp = skipcomment(*cpp);
1035 if (*cp == '!') {
1036 debug("eval%d !", prec(ops));
1037 cp++;
1038 lt = eval_unary(ops, valp, &cp);
1039 if (lt == LT_ERROR)
1040 return (LT_ERROR);
1041 if (lt != LT_IF) {
1042 *valp = !*valp;
1043 lt = *valp ? LT_TRUE : LT_FALSE;
1044 }
1045 } else if (*cp == '~') {
1046 debug("eval%d ~", prec(ops));
1047 cp++;
1048 lt = eval_unary(ops, valp, &cp);
1049 if (lt == LT_ERROR)
1050 return (LT_ERROR);
1051 if (lt != LT_IF) {
1052 *valp = ~(*valp);
1053 lt = *valp ? LT_TRUE : LT_FALSE;
1054 }
1055 } else if (*cp == '-') {
1056 debug("eval%d -", prec(ops));
1057 cp++;
1058 lt = eval_unary(ops, valp, &cp);
1059 if (lt == LT_ERROR)
1060 return (LT_ERROR);
1061 if (lt != LT_IF) {
1062 *valp = -(*valp);
1063 lt = *valp ? LT_TRUE : LT_FALSE;
1064 }
1065 } else if (*cp == '(') {
1066 cp++;
1067 debug("eval%d (", prec(ops));
1068 lt = eval_table(eval_ops, valp, &cp);
1069 if (lt == LT_ERROR)
1070 return (LT_ERROR);
1071 cp = skipcomment(cp);
1072 if (*cp++ != ')')
1073 return (LT_ERROR);
1074 } else if (isdigit((unsigned char)*cp)) {
1075 debug("eval%d number", prec(ops));
1076 *valp = strtol(cp, &ep, 0);
1077 if (ep == cp)
1078 return (LT_ERROR);
1079 lt = *valp ? LT_TRUE : LT_FALSE;
1080 cp = ep;
1081 } else if (matchsym("defined", cp) != NULL) {
1082 cp = skipcomment(cp+7);
1083 if (*cp == '(') {
1084 cp = skipcomment(cp+1);
1085 defparen = true;
1086 } else {
1087 defparen = false;
1088 }
1089 sym = findsym(&cp);
1090 cp = skipcomment(cp);
1091 if (defparen && *cp++ != ')') {
1092 debug("eval%d defined missing ')'", prec(ops));
1093 return (LT_ERROR);
1094 }
1095 if (sym == NULL) {
1096 debug("eval%d defined unknown", prec(ops));
1097 lt = LT_IF;
1098 } else {
1099 debug("eval%d defined %s", prec(ops), sym->name);
1100 *valp = (sym->value != NULL);
1101 lt = *valp ? LT_TRUE : LT_FALSE;
1102 }
1103 constexpr = false;
1104 } else if (!endsym(*cp)) {
1105 debug("eval%d symbol", prec(ops));
1106 sym = findsym(&cp);
1107 if (sym == NULL) {
1108 lt = LT_IF;
1109 cp = skipargs(cp);
1110 } else if (sym->value == NULL) {
1111 *valp = 0;
1112 lt = LT_FALSE;
1113 } else {
1114 *valp = strtol(sym->value, &ep, 0);
1115 if (*ep != '\0' || ep == sym->value)
1116 return (LT_ERROR);
1117 lt = *valp ? LT_TRUE : LT_FALSE;
1118 cp = skipargs(cp);
1119 }
1120 constexpr = false;
1121 } else {
1122 debug("eval%d bad expr", prec(ops));
1123 return (LT_ERROR);
1124 }
1125
1126 *cpp = cp;
1127 debug("eval%d = %d", prec(ops), *valp);
1128 return (lt);
1129 }
1130
1131 /*
1132 * Table-driven evaluation of binary operators.
1133 */
1134 static Linetype
eval_table(const struct ops * ops,long * valp,const char ** cpp)1135 eval_table(const struct ops *ops, long *valp, const char **cpp)
1136 {
1137 const struct op *op;
1138 const char *cp;
1139 long val = 0;
1140 Linetype lt, rt;
1141
1142 debug("eval%d", prec(ops));
1143 cp = *cpp;
1144 lt = ops->inner(ops+1, valp, &cp);
1145 if (lt == LT_ERROR)
1146 return (LT_ERROR);
1147 for (;;) {
1148 cp = skipcomment(cp);
1149 for (op = ops->op; op->str != NULL; op++) {
1150 if (strncmp(cp, op->str, strlen(op->str)) == 0) {
1151 /* assume only one-char operators have stop chars */
1152 if (op->stop != NULL && cp[1] != '\0' &&
1153 strchr(op->stop, cp[1]) != NULL)
1154 continue;
1155 else
1156 break;
1157 }
1158 }
1159 if (op->str == NULL)
1160 break;
1161 cp += strlen(op->str);
1162 debug("eval%d %s", prec(ops), op->str);
1163 rt = ops->inner(ops+1, &val, &cp);
1164 if (rt == LT_ERROR)
1165 return (LT_ERROR);
1166 lt = op->fn(valp, lt, *valp, rt, val);
1167 }
1168
1169 *cpp = cp;
1170 debug("eval%d = %d", prec(ops), *valp);
1171 debug("eval%d lt = %s", prec(ops), linetype_name[lt]);
1172 return (lt);
1173 }
1174
1175 /*
1176 * Evaluate the expression on a #if or #elif line. If we can work out
1177 * the result we return LT_TRUE or LT_FALSE accordingly, otherwise we
1178 * return just a generic LT_IF.
1179 */
1180 static Linetype
ifeval(const char ** cpp)1181 ifeval(const char **cpp)
1182 {
1183 Linetype ret;
1184 long val = 0;
1185
1186 debug("eval %s", *cpp);
1187 constexpr = killconsts ? false : true;
1188 ret = eval_table(eval_ops, &val, cpp);
1189 debug("eval = %d", val);
1190 return (constexpr ? LT_IF : ret == LT_ERROR ? LT_IF : ret);
1191 }
1192
1193 /*
1194 * Read a line and examine its initial part to determine if it is a
1195 * preprocessor directive. Returns NULL on EOF, or a pointer to a
1196 * preprocessor directive name, or a pointer to the zero byte at the
1197 * end of the line.
1198 */
1199 static const char *
skiphash(void)1200 skiphash(void)
1201 {
1202 const char *cp;
1203
1204 linenum++;
1205 if (fgets(tline, MAXLINE, input) == NULL) {
1206 if (ferror(input))
1207 err(2, "can't read %s", filename);
1208 else
1209 return (NULL);
1210 }
1211 cp = skipcomment(tline);
1212 if (linestate == LS_START && *cp == '#') {
1213 linestate = LS_HASH;
1214 return (skipcomment(cp + 1));
1215 } else if (*cp == '\0') {
1216 return (cp);
1217 } else {
1218 return (skipline(cp));
1219 }
1220 }
1221
1222 /*
1223 * Mark a line dirty and consume the rest of it, keeping track of the
1224 * lexical state.
1225 */
1226 static const char *
skipline(const char * cp)1227 skipline(const char *cp)
1228 {
1229 const char *pcp;
1230 if (*cp != '\0')
1231 linestate = LS_DIRTY;
1232 while (*cp != '\0') {
1233 cp = skipcomment(pcp = cp);
1234 if (pcp == cp)
1235 cp++;
1236 }
1237 return (cp);
1238 }
1239
1240 /*
1241 * Skip over comments, strings, and character literals and stop at the
1242 * next character position that is not whitespace. Between calls we keep
1243 * the comment state in the global variable incomment, and we also adjust
1244 * the global variable linestate when we see a newline.
1245 * XXX: doesn't cope with the buffer splitting inside a state transition.
1246 */
1247 static const char *
skipcomment(const char * cp)1248 skipcomment(const char *cp)
1249 {
1250 if (text || ignoring[depth]) {
1251 for (; isspace((unsigned char)*cp); cp++)
1252 if (*cp == '\n')
1253 linestate = LS_START;
1254 return (cp);
1255 }
1256 while (*cp != '\0')
1257 /* don't reset to LS_START after a line continuation */
1258 if (strncmp(cp, "\\\r\n", 3) == 0)
1259 cp += 3;
1260 else if (strncmp(cp, "\\\n", 2) == 0)
1261 cp += 2;
1262 else switch (incomment) {
1263 case NO_COMMENT:
1264 if (strncmp(cp, "/\\\r\n", 4) == 0) {
1265 incomment = STARTING_COMMENT;
1266 cp += 4;
1267 } else if (strncmp(cp, "/\\\n", 3) == 0) {
1268 incomment = STARTING_COMMENT;
1269 cp += 3;
1270 } else if (strncmp(cp, "/*", 2) == 0) {
1271 incomment = C_COMMENT;
1272 cp += 2;
1273 } else if (strncmp(cp, "//", 2) == 0) {
1274 incomment = CXX_COMMENT;
1275 cp += 2;
1276 } else if (strncmp(cp, "\'", 1) == 0) {
1277 incomment = CHAR_LITERAL;
1278 linestate = LS_DIRTY;
1279 cp += 1;
1280 } else if (strncmp(cp, "\"", 1) == 0) {
1281 incomment = STRING_LITERAL;
1282 linestate = LS_DIRTY;
1283 cp += 1;
1284 } else if (strncmp(cp, "R\"(", 3) == 0) {
1285 incomment = RAW_STRING_LITERAL;
1286 linestate = LS_DIRTY;
1287 cp += 3;
1288 } else if (strncmp(cp, "\n", 1) == 0) {
1289 linestate = LS_START;
1290 cp += 1;
1291 } else if (strchr(" \r\t", *cp) != NULL) {
1292 cp += 1;
1293 } else
1294 return (cp);
1295 continue;
1296 case CXX_COMMENT:
1297 if (strncmp(cp, "\n", 1) == 0) {
1298 incomment = NO_COMMENT;
1299 linestate = LS_START;
1300 }
1301 cp += 1;
1302 continue;
1303 case CHAR_LITERAL:
1304 case STRING_LITERAL:
1305 if ((incomment == CHAR_LITERAL && cp[0] == '\'') ||
1306 (incomment == STRING_LITERAL && cp[0] == '\"')) {
1307 incomment = NO_COMMENT;
1308 cp += 1;
1309 } else if (cp[0] == '\\') {
1310 if (cp[1] == '\0')
1311 cp += 1;
1312 else
1313 cp += 2;
1314 } else if (strncmp(cp, "\n", 1) == 0) {
1315 if (incomment == CHAR_LITERAL)
1316 error("Unterminated char literal");
1317 else
1318 error("Unterminated string literal");
1319 } else
1320 cp += 1;
1321 continue;
1322 case RAW_STRING_LITERAL:
1323 if (strncmp(cp, ")\"", 2) == 0) {
1324 incomment = NO_COMMENT;
1325 cp += 2;
1326 } else
1327 cp += 1;
1328 continue;
1329 case C_COMMENT:
1330 if (strncmp(cp, "*\\\r\n", 4) == 0) {
1331 incomment = FINISHING_COMMENT;
1332 cp += 4;
1333 } else if (strncmp(cp, "*\\\n", 3) == 0) {
1334 incomment = FINISHING_COMMENT;
1335 cp += 3;
1336 } else if (strncmp(cp, "*/", 2) == 0) {
1337 incomment = NO_COMMENT;
1338 cp += 2;
1339 } else
1340 cp += 1;
1341 continue;
1342 case STARTING_COMMENT:
1343 if (*cp == '*') {
1344 incomment = C_COMMENT;
1345 cp += 1;
1346 } else if (*cp == '/') {
1347 incomment = CXX_COMMENT;
1348 cp += 1;
1349 } else {
1350 incomment = NO_COMMENT;
1351 linestate = LS_DIRTY;
1352 }
1353 continue;
1354 case FINISHING_COMMENT:
1355 if (*cp == '/') {
1356 incomment = NO_COMMENT;
1357 cp += 1;
1358 } else
1359 incomment = C_COMMENT;
1360 continue;
1361 default:
1362 abort(); /* bug */
1363 }
1364 return (cp);
1365 }
1366
1367 /*
1368 * Skip macro arguments.
1369 */
1370 static const char *
skipargs(const char * cp)1371 skipargs(const char *cp)
1372 {
1373 const char *ocp = cp;
1374 int level = 0;
1375 cp = skipcomment(cp);
1376 if (*cp != '(')
1377 return (cp);
1378 do {
1379 if (*cp == '(')
1380 level++;
1381 if (*cp == ')')
1382 level--;
1383 cp = skipcomment(cp+1);
1384 } while (level != 0 && *cp != '\0');
1385 if (level == 0)
1386 return (cp);
1387 else
1388 /* Rewind and re-detect the syntax error later. */
1389 return (ocp);
1390 }
1391
1392 /*
1393 * Skip over an identifier.
1394 */
1395 static const char *
skipsym(const char * cp)1396 skipsym(const char *cp)
1397 {
1398 while (!endsym(*cp))
1399 ++cp;
1400 return (cp);
1401 }
1402
1403 /*
1404 * Skip whitespace and take a copy of any following identifier.
1405 */
1406 static const char *
getsym(const char ** cpp)1407 getsym(const char **cpp)
1408 {
1409 const char *cp = *cpp, *sym;
1410
1411 cp = skipcomment(cp);
1412 cp = skipsym(sym = cp);
1413 if (cp == sym)
1414 return NULL;
1415 *cpp = cp;
1416 return (xstrdup(sym, cp));
1417 }
1418
1419 /*
1420 * Check that s (a symbol) matches the start of t, and that the
1421 * following character in t is not a symbol character. Returns a
1422 * pointer to the following character in t if there is a match,
1423 * otherwise NULL.
1424 */
1425 static const char *
matchsym(const char * s,const char * t)1426 matchsym(const char *s, const char *t)
1427 {
1428 while (*s != '\0' && *t != '\0')
1429 if (*s != *t)
1430 return (NULL);
1431 else
1432 ++s, ++t;
1433 if (*s == '\0' && endsym(*t))
1434 return(t);
1435 else
1436 return(NULL);
1437 }
1438
1439 /*
1440 * Look for the symbol in the symbol table. If it is found, we return
1441 * the symbol table index, else we return -1.
1442 */
1443 static struct macro *
findsym(const char ** strp)1444 findsym(const char **strp)
1445 {
1446 const char *str;
1447 char *strkey;
1448 struct macro key, *res;
1449
1450 str = *strp;
1451 *strp = skipsym(str);
1452 if (symlist) {
1453 if (*strp == str)
1454 return (NULL);
1455 if (symdepth && firstsym)
1456 printf("%s%3d", zerosyms ? "" : "\n", depth);
1457 firstsym = zerosyms = false;
1458 printf("%s%.*s%s",
1459 symdepth ? " " : "",
1460 (int)(*strp-str), str,
1461 symdepth ? "" : "\n");
1462 /* we don't care about the value of the symbol */
1463 return (NULL);
1464 }
1465
1466 /*
1467 * 'str' just points into the current mid-parse input and is not
1468 * nul-terminated. We know the length of the symbol, *strp - str, but
1469 * need to provide a nul-terminated lookup key for RB_FIND's comparison
1470 * function. Create one here.
1471 */
1472 strkey = malloc(*strp - str + 1);
1473 memcpy(strkey, str, *strp - str);
1474 strkey[*strp - str] = 0;
1475
1476 key.name = strkey;
1477 res = RB_FIND(MACROMAP, ¯o_tree, &key);
1478 if (res != NULL)
1479 debugsym("findsym", res);
1480
1481 free(strkey);
1482 return (res);
1483 }
1484
1485 /*
1486 * Resolve indirect symbol values to their final definitions.
1487 */
1488 static void
indirectsym(void)1489 indirectsym(void)
1490 {
1491 const char *cp;
1492 int changed;
1493 struct macro *sym, *ind;
1494
1495 do {
1496 changed = 0;
1497 RB_FOREACH(sym, MACROMAP, ¯o_tree) {
1498 if (sym->value == NULL)
1499 continue;
1500 cp = sym->value;
1501 ind = findsym(&cp);
1502 if (ind == NULL || ind == sym ||
1503 *cp != '\0' ||
1504 ind->value == NULL ||
1505 ind->value == sym->value)
1506 continue;
1507 debugsym("indir...", sym);
1508 sym->value = ind->value;
1509 debugsym("...ectsym", sym);
1510 changed++;
1511 }
1512 } while (changed);
1513 }
1514
1515 /*
1516 * Add a symbol to the symbol table, specified with the format sym=val
1517 */
1518 static void
addsym1(bool ignorethis,bool definethis,char * symval)1519 addsym1(bool ignorethis, bool definethis, char *symval)
1520 {
1521 const char *sym, *val;
1522
1523 sym = symval;
1524 val = skipsym(sym);
1525 if (definethis && *val == '=') {
1526 symval[val - sym] = '\0';
1527 val = val + 1;
1528 } else if (*val == '\0') {
1529 val = definethis ? "1" : NULL;
1530 } else {
1531 usage();
1532 }
1533 addsym2(ignorethis, sym, val);
1534 }
1535
1536 /*
1537 * Add a symbol to the symbol table.
1538 */
1539 static void
addsym2(bool ignorethis,const char * symname,const char * val)1540 addsym2(bool ignorethis, const char *symname, const char *val)
1541 {
1542 const char *cp = symname;
1543 struct macro *sym, *r;
1544
1545 sym = findsym(&cp);
1546 if (sym == NULL) {
1547 sym = calloc(1, sizeof(*sym));
1548 sym->ignore = ignorethis;
1549 sym->name = symname;
1550 sym->value = val;
1551 r = RB_INSERT(MACROMAP, ¯o_tree, sym);
1552 assert(r == NULL);
1553 debugsym("addsym", sym);
1554 } else {
1555 sym->ignore = ignorethis;
1556 sym->value = val;
1557 debugsym("updsym", sym);
1558 }
1559 }
1560
1561 static void
debugsym(const char * why,const struct macro * sym)1562 debugsym(const char *why, const struct macro *sym)
1563 {
1564 debug("%s %s%c%s", why, sym->name,
1565 sym->value ? '=' : ' ',
1566 sym->value ? sym->value : "undef");
1567 }
1568
1569 /*
1570 * Add symbols to the symbol table from a file containing
1571 * #define and #undef preprocessor directives.
1572 */
1573 static void
defundefile(const char * fn)1574 defundefile(const char *fn)
1575 {
1576 filename = fn;
1577 input = fopen(fn, "rb");
1578 if (input == NULL)
1579 err(2, "can't open %s", fn);
1580 linenum = 0;
1581 while (defundef())
1582 ;
1583 if (ferror(input))
1584 err(2, "can't read %s", filename);
1585 else
1586 fclose(input);
1587 if (incomment)
1588 error("EOF in comment");
1589 }
1590
1591 /*
1592 * Read and process one #define or #undef directive
1593 */
1594 static bool
defundef(void)1595 defundef(void)
1596 {
1597 const char *cp, *kw, *sym, *val, *end;
1598
1599 cp = skiphash();
1600 if (cp == NULL)
1601 return (false);
1602 if (*cp == '\0')
1603 goto done;
1604 /* strip trailing whitespace, and do a fairly rough check to
1605 avoid unsupported multi-line preprocessor directives */
1606 end = cp + strlen(cp);
1607 while (end > tline && strchr(" \t\n\r", end[-1]) != NULL)
1608 --end;
1609 if (end > tline && end[-1] == '\\')
1610 Eioccc();
1611
1612 kw = cp;
1613 if ((cp = matchsym("define", kw)) != NULL) {
1614 sym = getsym(&cp);
1615 if (sym == NULL)
1616 error("Missing macro name in #define");
1617 if (*cp == '(') {
1618 val = "1";
1619 } else {
1620 cp = skipcomment(cp);
1621 val = (cp < end) ? xstrdup(cp, end) : "";
1622 }
1623 debug("#define");
1624 addsym2(false, sym, val);
1625 } else if ((cp = matchsym("undef", kw)) != NULL) {
1626 sym = getsym(&cp);
1627 if (sym == NULL)
1628 error("Missing macro name in #undef");
1629 cp = skipcomment(cp);
1630 debug("#undef");
1631 addsym2(false, sym, NULL);
1632 } else {
1633 error("Unrecognized preprocessor directive");
1634 }
1635 skipline(cp);
1636 done:
1637 debug("parser line %d state %s comment %s line", linenum,
1638 comment_name[incomment], linestate_name[linestate]);
1639 return (true);
1640 }
1641
1642 /*
1643 * Concatenate two strings into new memory, checking for failure.
1644 */
1645 static char *
astrcat(const char * s1,const char * s2)1646 astrcat(const char *s1, const char *s2)
1647 {
1648 char *s;
1649 int len;
1650 size_t size;
1651
1652 len = snprintf(NULL, 0, "%s%s", s1, s2);
1653 if (len < 0)
1654 err(2, "snprintf");
1655 size = (size_t)len + 1;
1656 s = (char *)malloc(size);
1657 if (s == NULL)
1658 err(2, "malloc");
1659 snprintf(s, size, "%s%s", s1, s2);
1660 return (s);
1661 }
1662
1663 /*
1664 * Duplicate a segment of a string, checking for failure.
1665 */
1666 static const char *
xstrdup(const char * start,const char * end)1667 xstrdup(const char *start, const char *end)
1668 {
1669 size_t n;
1670 char *s;
1671
1672 if (end < start) abort(); /* bug */
1673 n = (size_t)(end - start) + 1;
1674 s = (char *)malloc(n);
1675 if (s == NULL)
1676 err(2, "malloc");
1677 snprintf(s, n, "%s", start);
1678 return (s);
1679 }
1680
1681 /*
1682 * Diagnostics.
1683 */
1684 static void
debug(const char * msg,...)1685 debug(const char *msg, ...)
1686 {
1687 va_list ap;
1688
1689 if (debugging) {
1690 va_start(ap, msg);
1691 vwarnx(msg, ap);
1692 va_end(ap);
1693 }
1694 }
1695
1696 static void
error(const char * msg)1697 error(const char *msg)
1698 {
1699 if (depth == 0)
1700 warnx("%s: %d: %s", filename, linenum, msg);
1701 else
1702 warnx("%s: %d: %s (#if line %d depth %d)",
1703 filename, linenum, msg, stifline[depth], depth);
1704 closeio();
1705 errx(2, "Output may be truncated");
1706 }
1707