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 
59 const char copyright[] =
60     "@(#) $Version: unifdef-2.5 $\n"
61     "@(#) $Author: Tony Finch (dot@dotat.at) $\n"
62     "@(#) $URL: http://dotat.at/prog/unifdef $\n"
63 ;
64 
65 /* types of input lines: */
66 typedef enum {
67 	LT_TRUEI,		/* a true #if with ignore flag */
68 	LT_FALSEI,		/* a false #if with ignore flag */
69 	LT_IF,			/* an unknown #if */
70 	LT_TRUE,		/* a true #if */
71 	LT_FALSE,		/* a false #if */
72 	LT_ELIF,		/* an unknown #elif */
73 	LT_ELTRUE,		/* a true #elif */
74 	LT_ELFALSE,		/* a false #elif */
75 	LT_ELSE,		/* #else */
76 	LT_ENDIF,		/* #endif */
77 	LT_DODGY,		/* flag: directive is not on one line */
78 	LT_DODGY_LAST = LT_DODGY + LT_ENDIF,
79 	LT_PLAIN,		/* ordinary line */
80 	LT_EOF,			/* end of file */
81 	LT_ERROR,		/* unevaluable #if */
82 	LT_COUNT
83 } Linetype;
84 
85 static char const * const linetype_name[] = {
86 	"TRUEI", "FALSEI", "IF", "TRUE", "FALSE",
87 	"ELIF", "ELTRUE", "ELFALSE", "ELSE", "ENDIF",
88 	"DODGY TRUEI", "DODGY FALSEI",
89 	"DODGY IF", "DODGY TRUE", "DODGY FALSE",
90 	"DODGY ELIF", "DODGY ELTRUE", "DODGY ELFALSE",
91 	"DODGY ELSE", "DODGY ENDIF",
92 	"PLAIN", "EOF", "ERROR"
93 };
94 
95 /* state of #if processing */
96 typedef enum {
97 	IS_OUTSIDE,
98 	IS_FALSE_PREFIX,	/* false #if followed by false #elifs */
99 	IS_TRUE_PREFIX,		/* first non-false #(el)if is true */
100 	IS_PASS_MIDDLE,		/* first non-false #(el)if is unknown */
101 	IS_FALSE_MIDDLE,	/* a false #elif after a pass state */
102 	IS_TRUE_MIDDLE,		/* a true #elif after a pass state */
103 	IS_PASS_ELSE,		/* an else after a pass state */
104 	IS_FALSE_ELSE,		/* an else after a true state */
105 	IS_TRUE_ELSE,		/* an else after only false states */
106 	IS_FALSE_TRAILER,	/* #elifs after a true are false */
107 	IS_COUNT
108 } Ifstate;
109 
110 static char const * const ifstate_name[] = {
111 	"OUTSIDE", "FALSE_PREFIX", "TRUE_PREFIX",
112 	"PASS_MIDDLE", "FALSE_MIDDLE", "TRUE_MIDDLE",
113 	"PASS_ELSE", "FALSE_ELSE", "TRUE_ELSE",
114 	"FALSE_TRAILER"
115 };
116 
117 /* state of comment parser */
118 typedef enum {
119 	NO_COMMENT = false,	/* outside a comment */
120 	C_COMMENT,		/* in a comment like this one */
121 	CXX_COMMENT,		/* between // and end of line */
122 	STARTING_COMMENT,	/* just after slash-backslash-newline */
123 	FINISHING_COMMENT,	/* star-backslash-newline in a C comment */
124 	CHAR_LITERAL,		/* inside '' */
125 	STRING_LITERAL		/* inside "" */
126 } Comment_state;
127 
128 static char const * const comment_name[] = {
129 	"NO", "C", "CXX", "STARTING", "FINISHING", "CHAR", "STRING"
130 };
131 
132 /* state of preprocessor line parser */
133 typedef enum {
134 	LS_START,		/* only space and comments on this line */
135 	LS_HASH,		/* only space, comments, and a hash */
136 	LS_DIRTY		/* this line can't be a preprocessor line */
137 } Line_state;
138 
139 static char const * const linestate_name[] = {
140 	"START", "HASH", "DIRTY"
141 };
142 
143 /*
144  * Minimum translation limits from ISO/IEC 9899:1999 5.2.4.1
145  */
146 #define	MAXDEPTH        64			/* maximum #if nesting */
147 #define	MAXLINE         4096			/* maximum length of line */
148 #define	MAXSYMS         4096			/* maximum number of symbols */
149 
150 /*
151  * Sometimes when editing a keyword the replacement text is longer, so
152  * we leave some space at the end of the tline buffer to accommodate this.
153  */
154 #define	EDITSLOP        10
155 
156 /*
157  * For temporary filenames
158  */
159 #define TEMPLATE        "unifdef.XXXXXX"
160 
161 /*
162  * Globals.
163  */
164 
165 static bool             compblank;		/* -B: compress blank lines */
166 static bool             lnblank;		/* -b: blank deleted lines */
167 static bool             complement;		/* -c: do the complement */
168 static bool             debugging;		/* -d: debugging reports */
169 static bool             iocccok;		/* -e: fewer IOCCC errors */
170 static bool             strictlogic;		/* -K: keep ambiguous #ifs */
171 static bool             killconsts;		/* -k: eval constant #ifs */
172 static bool             lnnum;			/* -n: add #line directives */
173 static bool             symlist;		/* -s: output symbol list */
174 static bool             symdepth;		/* -S: output symbol depth */
175 static bool             text;			/* -t: this is a text file */
176 
177 static const char      *symname[MAXSYMS];	/* symbol name */
178 static const char      *value[MAXSYMS];		/* -Dsym=value */
179 static bool             ignore[MAXSYMS];	/* -iDsym or -iUsym */
180 static int              nsyms;			/* number of symbols */
181 
182 static FILE            *input;			/* input file pointer */
183 static const char      *filename;		/* input file name */
184 static int              linenum;		/* current line number */
185 static FILE            *output;			/* output file pointer */
186 static const char      *ofilename;		/* output file name */
187 static bool             overwriting;		/* output overwrites input */
188 static char             tempname[FILENAME_MAX];	/* used when overwriting */
189 
190 static char             tline[MAXLINE+EDITSLOP];/* input buffer plus space */
191 static char            *keyword;		/* used for editing #elif's */
192 
193 static const char      *newline;		/* input file format */
194 static const char       newline_unix[] = "\n";
195 static const char       newline_crlf[] = "\r\n";
196 
197 static Comment_state    incomment;		/* comment parser state */
198 static Line_state       linestate;		/* #if line parser state */
199 static Ifstate          ifstate[MAXDEPTH];	/* #if processor state */
200 static bool             ignoring[MAXDEPTH];	/* ignore comments state */
201 static int              stifline[MAXDEPTH];	/* start of current #if */
202 static int              depth;			/* current #if nesting */
203 static int              delcount;		/* count of deleted lines */
204 static unsigned         blankcount;		/* count of blank lines */
205 static unsigned         blankmax;		/* maximum recent blankcount */
206 static bool             constexpr;		/* constant #if expression */
207 static bool             zerosyms = true;	/* to format symdepth output */
208 static bool             firstsym;		/* ditto */
209 
210 static int              exitstat;		/* program exit status */
211 
212 static void             addsym(bool, bool, char *);
213 static void             closeout(void);
214 static void             debug(const char *, ...);
215 static void             done(void);
216 static void             error(const char *);
217 static int              findsym(const char *);
218 static void             flushline(bool);
219 static Linetype         parseline(void);
220 static Linetype         ifeval(const char **);
221 static void             ignoreoff(void);
222 static void             ignoreon(void);
223 static void             keywordedit(const char *);
224 static void             nest(void);
225 static void             process(void);
226 static const char      *skipargs(const char *);
227 static const char      *skipcomment(const char *);
228 static const char      *skipsym(const char *);
229 static void             state(Ifstate);
230 static int              strlcmp(const char *, const char *, size_t);
231 static void             unnest(void);
232 static void             usage(void);
233 static void             version(void);
234 
235 #define endsym(c) (!isalnum((unsigned char)c) && c != '_')
236 
237 /*
238  * The main program.
239  */
240 int
main(int argc,char * argv[])241 main(int argc, char *argv[])
242 {
243 	int opt;
244 
245 	while ((opt = getopt(argc, argv, "i:D:U:I:o:bBcdeKklnsStV")) != -1)
246 		switch (opt) {
247 		case 'i': /* treat stuff controlled by these symbols as text */
248 			/*
249 			 * For strict backwards-compatibility the U or D
250 			 * should be immediately after the -i but it doesn't
251 			 * matter much if we relax that requirement.
252 			 */
253 			opt = *optarg++;
254 			if (opt == 'D')
255 				addsym(true, true, optarg);
256 			else if (opt == 'U')
257 				addsym(true, false, optarg);
258 			else
259 				usage();
260 			break;
261 		case 'D': /* define a symbol */
262 			addsym(false, true, optarg);
263 			break;
264 		case 'U': /* undef a symbol */
265 			addsym(false, false, optarg);
266 			break;
267 		case 'I': /* no-op for compatibility with cpp */
268 			break;
269 		case 'b': /* blank deleted lines instead of omitting them */
270 		case 'l': /* backwards compatibility */
271 			lnblank = true;
272 			break;
273 		case 'B': /* compress blank lines around removed section */
274 			compblank = true;
275 			break;
276 		case 'c': /* treat -D as -U and vice versa */
277 			complement = true;
278 			break;
279 		case 'd':
280 			debugging = true;
281 			break;
282 		case 'e': /* fewer errors from dodgy lines */
283 			iocccok = true;
284 			break;
285 		case 'K': /* keep ambiguous #ifs */
286 			strictlogic = true;
287 			break;
288 		case 'k': /* process constant #ifs */
289 			killconsts = true;
290 			break;
291 		case 'n': /* add #line directive after deleted lines */
292 			lnnum = true;
293 			break;
294 		case 'o': /* output to a file */
295 			ofilename = optarg;
296 			break;
297 		case 's': /* only output list of symbols that control #ifs */
298 			symlist = true;
299 			break;
300 		case 'S': /* list symbols with their nesting depth */
301 			symlist = symdepth = true;
302 			break;
303 		case 't': /* don't parse C comments */
304 			text = true;
305 			break;
306 		case 'V': /* print version */
307 			version();
308 		default:
309 			usage();
310 		}
311 	argc -= optind;
312 	argv += optind;
313 	if (compblank && lnblank)
314 		errx(2, "-B and -b are mutually exclusive");
315 	if (argc > 1) {
316 		errx(2, "can only do one file");
317 	} else if (argc == 1 && strcmp(*argv, "-") != 0) {
318 		filename = *argv;
319 		input = fopen(filename, "rb");
320 		if (input == NULL)
321 			err(2, "can't open %s", filename);
322 	} else {
323 		filename = "[stdin]";
324 		input = stdin;
325 	}
326 	if (ofilename == NULL) {
327 		ofilename = "[stdout]";
328 		output = stdout;
329 	} else {
330 		struct stat ist, ost;
331 		if (stat(ofilename, &ost) == 0 &&
332 		    fstat(fileno(input), &ist) == 0)
333 			overwriting = (ist.st_dev == ost.st_dev
334 				    && ist.st_ino == ost.st_ino);
335 		if (overwriting) {
336 			const char *dirsep;
337 			int ofd;
338 
339 			dirsep = strrchr(ofilename, '/');
340 			if (dirsep != NULL)
341 				snprintf(tempname, sizeof(tempname),
342 				    "%.*s/" TEMPLATE,
343 				    (int)(dirsep - ofilename), ofilename);
344 			else
345 				snprintf(tempname, sizeof(tempname),
346 				    TEMPLATE);
347 			ofd = mkstemp(tempname);
348 			if (ofd != -1)
349 				output = fdopen(ofd, "wb+");
350 			if (output == NULL)
351 				err(2, "can't create temporary file");
352 			fchmod(ofd, ist.st_mode & (S_IRWXU|S_IRWXG|S_IRWXO));
353 		} else {
354 			output = fopen(ofilename, "wb");
355 			if (output == NULL)
356 				err(2, "can't open %s", ofilename);
357 		}
358 	}
359 	process();
360 	abort(); /* bug */
361 }
362 
363 static void
version(void)364 version(void)
365 {
366 	const char *c = copyright;
367 	for (;;) {
368 		while (*++c != '$')
369 			if (*c == '\0')
370 				exit(0);
371 		while (*++c != '$')
372 			putc(*c, stderr);
373 		putc('\n', stderr);
374 	}
375 }
376 
377 static void
usage(void)378 usage(void)
379 {
380 	fprintf(stderr, "usage: unifdef [-bBcdeKknsStV] [-Ipath]"
381 	    " [-Dsym[=val]] [-Usym] [-iDsym[=val]] [-iUsym] ... [file]\n");
382 	exit(2);
383 }
384 
385 /*
386  * A state transition function alters the global #if processing state
387  * in a particular way. The table below is indexed by the current
388  * processing state and the type of the current line.
389  *
390  * Nesting is handled by keeping a stack of states; some transition
391  * functions increase or decrease the depth. They also maintain the
392  * ignore state on a stack. In some complicated cases they have to
393  * alter the preprocessor directive, as follows.
394  *
395  * When we have processed a group that starts off with a known-false
396  * #if/#elif sequence (which has therefore been deleted) followed by a
397  * #elif that we don't understand and therefore must keep, we edit the
398  * latter into a #if to keep the nesting correct. We use memcpy() to
399  * overwrite the 4 byte token "elif" with "if  " without a '\0' byte.
400  *
401  * When we find a true #elif in a group, the following block will
402  * always be kept and the rest of the sequence after the next #elif or
403  * #else will be discarded. We edit the #elif into a #else and the
404  * following directive to #endif since this has the desired behaviour.
405  *
406  * "Dodgy" directives are split across multiple lines, the most common
407  * example being a multi-line comment hanging off the right of the
408  * directive. We can handle them correctly only if there is no change
409  * from printing to dropping (or vice versa) caused by that directive.
410  * If the directive is the first of a group we have a choice between
411  * failing with an error, or passing it through unchanged instead of
412  * evaluating it. The latter is not the default to avoid questions from
413  * users about unifdef unexpectedly leaving behind preprocessor directives.
414  */
415 typedef void state_fn(void);
416 
417 /* report an error */
Eelif(void)418 static void Eelif (void) { error("Inappropriate #elif"); }
Eelse(void)419 static void Eelse (void) { error("Inappropriate #else"); }
Eendif(void)420 static void Eendif(void) { error("Inappropriate #endif"); }
Eeof(void)421 static void Eeof  (void) { error("Premature EOF"); }
Eioccc(void)422 static void Eioccc(void) { error("Obfuscated preprocessor control line"); }
423 /* plain line handling */
print(void)424 static void print (void) { flushline(true); }
drop(void)425 static void drop  (void) { flushline(false); }
426 /* output lacks group's start line */
Strue(void)427 static void Strue (void) { drop();  ignoreoff(); state(IS_TRUE_PREFIX); }
Sfalse(void)428 static void Sfalse(void) { drop();  ignoreoff(); state(IS_FALSE_PREFIX); }
Selse(void)429 static void Selse (void) { drop();               state(IS_TRUE_ELSE); }
430 /* print/pass this block */
Pelif(void)431 static void Pelif (void) { print(); ignoreoff(); state(IS_PASS_MIDDLE); }
Pelse(void)432 static void Pelse (void) { print();              state(IS_PASS_ELSE); }
Pendif(void)433 static void Pendif(void) { print(); unnest(); }
434 /* discard this block */
Dfalse(void)435 static void Dfalse(void) { drop();  ignoreoff(); state(IS_FALSE_TRAILER); }
Delif(void)436 static void Delif (void) { drop();  ignoreoff(); state(IS_FALSE_MIDDLE); }
Delse(void)437 static void Delse (void) { drop();               state(IS_FALSE_ELSE); }
Dendif(void)438 static void Dendif(void) { drop();  unnest(); }
439 /* first line of group */
Fdrop(void)440 static void Fdrop (void) { nest();  Dfalse(); }
Fpass(void)441 static void Fpass (void) { nest();  Pelif(); }
Ftrue(void)442 static void Ftrue (void) { nest();  Strue(); }
Ffalse(void)443 static void Ffalse(void) { nest();  Sfalse(); }
444 /* variable pedantry for obfuscated lines */
Oiffy(void)445 static void Oiffy (void) { if (!iocccok) Eioccc(); Fpass(); ignoreon(); }
Oif(void)446 static void Oif   (void) { if (!iocccok) Eioccc(); Fpass(); }
Oelif(void)447 static void Oelif (void) { if (!iocccok) Eioccc(); Pelif(); }
448 /* ignore comments in this block */
Idrop(void)449 static void Idrop (void) { Fdrop();  ignoreon(); }
Itrue(void)450 static void Itrue (void) { Ftrue();  ignoreon(); }
Ifalse(void)451 static void Ifalse(void) { Ffalse(); ignoreon(); }
452 /* modify this line */
Mpass(void)453 static void Mpass (void) { memcpy(keyword, "if  ", 4); Pelif(); }
Mtrue(void)454 static void Mtrue (void) { keywordedit("else");  state(IS_TRUE_MIDDLE); }
Melif(void)455 static void Melif (void) { keywordedit("endif"); state(IS_FALSE_TRAILER); }
Melse(void)456 static void Melse (void) { keywordedit("endif"); state(IS_FALSE_ELSE); }
457 
458 static state_fn * const trans_table[IS_COUNT][LT_COUNT] = {
459 /* IS_OUTSIDE */
460 { Itrue, Ifalse,Fpass, Ftrue, Ffalse,Eelif, Eelif, Eelif, Eelse, Eendif,
461   Oiffy, Oiffy, Fpass, Oif,   Oif,   Eelif, Eelif, Eelif, Eelse, Eendif,
462   print, done,  abort },
463 /* IS_FALSE_PREFIX */
464 { Idrop, Idrop, Fdrop, Fdrop, Fdrop, Mpass, Strue, Sfalse,Selse, Dendif,
465   Idrop, Idrop, Fdrop, Fdrop, Fdrop, Mpass, Eioccc,Eioccc,Eioccc,Eioccc,
466   drop,  Eeof,  abort },
467 /* IS_TRUE_PREFIX */
468 { Itrue, Ifalse,Fpass, Ftrue, Ffalse,Dfalse,Dfalse,Dfalse,Delse, Dendif,
469   Oiffy, Oiffy, Fpass, Oif,   Oif,   Eioccc,Eioccc,Eioccc,Eioccc,Eioccc,
470   print, Eeof,  abort },
471 /* IS_PASS_MIDDLE */
472 { Itrue, Ifalse,Fpass, Ftrue, Ffalse,Pelif, Mtrue, Delif, Pelse, Pendif,
473   Oiffy, Oiffy, Fpass, Oif,   Oif,   Pelif, Oelif, Oelif, Pelse, Pendif,
474   print, Eeof,  abort },
475 /* IS_FALSE_MIDDLE */
476 { Idrop, Idrop, Fdrop, Fdrop, Fdrop, Pelif, Mtrue, Delif, Pelse, Pendif,
477   Idrop, Idrop, Fdrop, Fdrop, Fdrop, Eioccc,Eioccc,Eioccc,Eioccc,Eioccc,
478   drop,  Eeof,  abort },
479 /* IS_TRUE_MIDDLE */
480 { Itrue, Ifalse,Fpass, Ftrue, Ffalse,Melif, Melif, Melif, Melse, Pendif,
481   Oiffy, Oiffy, Fpass, Oif,   Oif,   Eioccc,Eioccc,Eioccc,Eioccc,Pendif,
482   print, Eeof,  abort },
483 /* IS_PASS_ELSE */
484 { Itrue, Ifalse,Fpass, Ftrue, Ffalse,Eelif, Eelif, Eelif, Eelse, Pendif,
485   Oiffy, Oiffy, Fpass, Oif,   Oif,   Eelif, Eelif, Eelif, Eelse, Pendif,
486   print, Eeof,  abort },
487 /* IS_FALSE_ELSE */
488 { Idrop, Idrop, Fdrop, Fdrop, Fdrop, Eelif, Eelif, Eelif, Eelse, Dendif,
489   Idrop, Idrop, Fdrop, Fdrop, Fdrop, Eelif, Eelif, Eelif, Eelse, Eioccc,
490   drop,  Eeof,  abort },
491 /* IS_TRUE_ELSE */
492 { Itrue, Ifalse,Fpass, Ftrue, Ffalse,Eelif, Eelif, Eelif, Eelse, Dendif,
493   Oiffy, Oiffy, Fpass, Oif,   Oif,   Eelif, Eelif, Eelif, Eelse, Eioccc,
494   print, Eeof,  abort },
495 /* IS_FALSE_TRAILER */
496 { Idrop, Idrop, Fdrop, Fdrop, Fdrop, Dfalse,Dfalse,Dfalse,Delse, Dendif,
497   Idrop, Idrop, Fdrop, Fdrop, Fdrop, Dfalse,Dfalse,Dfalse,Delse, Eioccc,
498   drop,  Eeof,  abort }
499 /*TRUEI  FALSEI IF     TRUE   FALSE  ELIF   ELTRUE ELFALSE ELSE  ENDIF
500   TRUEI  FALSEI IF     TRUE   FALSE  ELIF   ELTRUE ELFALSE ELSE  ENDIF (DODGY)
501   PLAIN  EOF    ERROR */
502 };
503 
504 /*
505  * State machine utility functions
506  */
507 static void
ignoreoff(void)508 ignoreoff(void)
509 {
510 	if (depth == 0)
511 		abort(); /* bug */
512 	ignoring[depth] = ignoring[depth-1];
513 }
514 static void
ignoreon(void)515 ignoreon(void)
516 {
517 	ignoring[depth] = true;
518 }
519 static void
keywordedit(const char * replacement)520 keywordedit(const char *replacement)
521 {
522 	snprintf(keyword, tline + sizeof(tline) - keyword,
523 	    "%s%s", replacement, newline);
524 	print();
525 }
526 static void
nest(void)527 nest(void)
528 {
529 	if (depth > MAXDEPTH-1)
530 		abort(); /* bug */
531 	if (depth == MAXDEPTH-1)
532 		error("Too many levels of nesting");
533 	depth += 1;
534 	stifline[depth] = linenum;
535 }
536 static void
unnest(void)537 unnest(void)
538 {
539 	if (depth == 0)
540 		abort(); /* bug */
541 	depth -= 1;
542 }
543 static void
state(Ifstate is)544 state(Ifstate is)
545 {
546 	ifstate[depth] = is;
547 }
548 
549 /*
550  * Write a line to the output or not, according to command line options.
551  */
552 static void
flushline(bool keep)553 flushline(bool keep)
554 {
555 	if (symlist)
556 		return;
557 	if (keep ^ complement) {
558 		bool blankline = tline[strspn(tline, " \t\r\n")] == '\0';
559 		if (blankline && compblank && blankcount != blankmax) {
560 			delcount += 1;
561 			blankcount += 1;
562 		} else {
563 			if (lnnum && delcount > 0)
564 				printf("#line %d%s", linenum, newline);
565 			fputs(tline, output);
566 			delcount = 0;
567 			blankmax = blankcount = blankline ? blankcount + 1 : 0;
568 		}
569 	} else {
570 		if (lnblank)
571 			fputs(newline, output);
572 		exitstat = 1;
573 		delcount += 1;
574 		blankcount = 0;
575 	}
576 	if (debugging)
577 		fflush(output);
578 }
579 
580 /*
581  * The driver for the state machine.
582  */
583 static void
process(void)584 process(void)
585 {
586 	/* When compressing blank lines, act as if the file
587 	   is preceded by a large number of blank lines. */
588 	blankmax = blankcount = 1000;
589 	for (;;) {
590 		Linetype lineval = parseline();
591 		trans_table[ifstate[depth]][lineval]();
592 		debug("process line %d %s -> %s depth %d",
593 		    linenum, linetype_name[lineval],
594 		    ifstate_name[ifstate[depth]], depth);
595 	}
596 }
597 
598 /*
599  * Flush the output and handle errors.
600  */
601 static void
closeout(void)602 closeout(void)
603 {
604 	if (symdepth && !zerosyms)
605 		printf("\n");
606 	if (fclose(output) == EOF) {
607 		warn("couldn't write to %s", ofilename);
608 		if (overwriting) {
609 			unlink(tempname);
610 			errx(2, "%s unchanged", filename);
611 		} else {
612 			exit(2);
613 		}
614 	}
615 }
616 
617 /*
618  * Clean up and exit.
619  */
620 static void
done(void)621 done(void)
622 {
623 	if (incomment)
624 		error("EOF in comment");
625 	closeout();
626 	if (overwriting && rename(tempname, ofilename) == -1) {
627 		warn("couldn't rename temporary file");
628 		unlink(tempname);
629 		errx(2, "%s unchanged", ofilename);
630 	}
631 	exit(exitstat);
632 }
633 
634 /*
635  * Parse a line and determine its type. We keep the preprocessor line
636  * parser state between calls in the global variable linestate, with
637  * help from skipcomment().
638  */
639 static Linetype
parseline(void)640 parseline(void)
641 {
642 	const char *cp;
643 	int cursym;
644 	int kwlen;
645 	Linetype retval;
646 	Comment_state wascomment;
647 
648 	linenum++;
649 	if (fgets(tline, MAXLINE, input) == NULL)
650 		return (LT_EOF);
651 	if (newline == NULL) {
652 		if (strrchr(tline, '\n') == strrchr(tline, '\r') + 1)
653 			newline = newline_crlf;
654 		else
655 			newline = newline_unix;
656 	}
657 	retval = LT_PLAIN;
658 	wascomment = incomment;
659 	cp = skipcomment(tline);
660 	if (linestate == LS_START) {
661 		if (*cp == '#') {
662 			linestate = LS_HASH;
663 			firstsym = true;
664 			cp = skipcomment(cp + 1);
665 		} else if (*cp != '\0')
666 			linestate = LS_DIRTY;
667 	}
668 	if (!incomment && linestate == LS_HASH) {
669 		keyword = tline + (cp - tline);
670 		cp = skipsym(cp);
671 		kwlen = cp - keyword;
672 		/* no way can we deal with a continuation inside a keyword */
673 		if (strncmp(cp, "\\\r\n", 3) == 0 ||
674 		    strncmp(cp, "\\\n", 2) == 0)
675 			Eioccc();
676 		if (strlcmp("ifdef", keyword, kwlen) == 0 ||
677 		    strlcmp("ifndef", keyword, kwlen) == 0) {
678 			cp = skipcomment(cp);
679 			if ((cursym = findsym(cp)) < 0)
680 				retval = LT_IF;
681 			else {
682 				retval = (keyword[2] == 'n')
683 				    ? LT_FALSE : LT_TRUE;
684 				if (value[cursym] == NULL)
685 					retval = (retval == LT_TRUE)
686 					    ? LT_FALSE : LT_TRUE;
687 				if (ignore[cursym])
688 					retval = (retval == LT_TRUE)
689 					    ? LT_TRUEI : LT_FALSEI;
690 			}
691 			cp = skipsym(cp);
692 		} else if (strlcmp("if", keyword, kwlen) == 0)
693 			retval = ifeval(&cp);
694 		else if (strlcmp("elif", keyword, kwlen) == 0)
695 			retval = ifeval(&cp) - LT_IF + LT_ELIF;
696 		else if (strlcmp("else", keyword, kwlen) == 0)
697 			retval = LT_ELSE;
698 		else if (strlcmp("endif", keyword, kwlen) == 0)
699 			retval = LT_ENDIF;
700 		else {
701 			linestate = LS_DIRTY;
702 			retval = LT_PLAIN;
703 		}
704 		cp = skipcomment(cp);
705 		if (*cp != '\0') {
706 			linestate = LS_DIRTY;
707 			if (retval == LT_TRUE || retval == LT_FALSE ||
708 			    retval == LT_TRUEI || retval == LT_FALSEI)
709 				retval = LT_IF;
710 			if (retval == LT_ELTRUE || retval == LT_ELFALSE)
711 				retval = LT_ELIF;
712 		}
713 		if (retval != LT_PLAIN && (wascomment || incomment)) {
714 			retval += LT_DODGY;
715 			if (incomment)
716 				linestate = LS_DIRTY;
717 		}
718 		/* skipcomment normally changes the state, except
719 		   if the last line of the file lacks a newline, or
720 		   if there is too much whitespace in a directive */
721 		if (linestate == LS_HASH) {
722 			size_t len = cp - tline;
723 			if (fgets(tline + len, MAXLINE - len, input) == NULL) {
724 				/* append the missing newline */
725 				strcpy(tline + len, newline);
726 				cp += strlen(newline);
727 				linestate = LS_START;
728 			} else {
729 				linestate = LS_DIRTY;
730 			}
731 		}
732 	}
733 	if (linestate == LS_DIRTY) {
734 		while (*cp != '\0')
735 			cp = skipcomment(cp + 1);
736 	}
737 	debug("parser line %d state %s comment %s line", linenum,
738 	    comment_name[incomment], linestate_name[linestate]);
739 	return (retval);
740 }
741 
742 /*
743  * These are the binary operators that are supported by the expression
744  * evaluator.
745  */
op_strict(int * p,int v,Linetype at,Linetype bt)746 static Linetype op_strict(int *p, int v, Linetype at, Linetype bt) {
747 	if(at == LT_IF || bt == LT_IF) return (LT_IF);
748 	return (*p = v, v ? LT_TRUE : LT_FALSE);
749 }
op_lt(int * p,Linetype at,int a,Linetype bt,int b)750 static Linetype op_lt(int *p, Linetype at, int a, Linetype bt, int b) {
751 	return op_strict(p, a < b, at, bt);
752 }
op_gt(int * p,Linetype at,int a,Linetype bt,int b)753 static Linetype op_gt(int *p, Linetype at, int a, Linetype bt, int b) {
754 	return op_strict(p, a > b, at, bt);
755 }
op_le(int * p,Linetype at,int a,Linetype bt,int b)756 static Linetype op_le(int *p, Linetype at, int a, Linetype bt, int b) {
757 	return op_strict(p, a <= b, at, bt);
758 }
op_ge(int * p,Linetype at,int a,Linetype bt,int b)759 static Linetype op_ge(int *p, Linetype at, int a, Linetype bt, int b) {
760 	return op_strict(p, a >= b, at, bt);
761 }
op_eq(int * p,Linetype at,int a,Linetype bt,int b)762 static Linetype op_eq(int *p, Linetype at, int a, Linetype bt, int b) {
763 	return op_strict(p, a == b, at, bt);
764 }
op_ne(int * p,Linetype at,int a,Linetype bt,int b)765 static Linetype op_ne(int *p, Linetype at, int a, Linetype bt, int b) {
766 	return op_strict(p, a != b, at, bt);
767 }
op_or(int * p,Linetype at,int a,Linetype bt,int b)768 static Linetype op_or(int *p, Linetype at, int a, Linetype bt, int b) {
769 	if (!strictlogic && (at == LT_TRUE || bt == LT_TRUE))
770 		return (*p = 1, LT_TRUE);
771 	return op_strict(p, a || b, at, bt);
772 }
op_and(int * p,Linetype at,int a,Linetype bt,int b)773 static Linetype op_and(int *p, Linetype at, int a, Linetype bt, int b) {
774 	if (!strictlogic && (at == LT_FALSE || bt == LT_FALSE))
775 		return (*p = 0, LT_FALSE);
776 	return op_strict(p, a && b, at, bt);
777 }
778 
779 /*
780  * An evaluation function takes three arguments, as follows: (1) a pointer to
781  * an element of the precedence table which lists the operators at the current
782  * level of precedence; (2) a pointer to an integer which will receive the
783  * value of the expression; and (3) a pointer to a char* that points to the
784  * expression to be evaluated and that is updated to the end of the expression
785  * when evaluation is complete. The function returns LT_FALSE if the value of
786  * the expression is zero, LT_TRUE if it is non-zero, LT_IF if the expression
787  * depends on an unknown symbol, or LT_ERROR if there is a parse failure.
788  */
789 struct ops;
790 
791 typedef Linetype eval_fn(const struct ops *, int *, const char **);
792 
793 static eval_fn eval_table, eval_unary;
794 
795 /*
796  * The precedence table. Expressions involving binary operators are evaluated
797  * in a table-driven way by eval_table. When it evaluates a subexpression it
798  * calls the inner function with its first argument pointing to the next
799  * element of the table. Innermost expressions have special non-table-driven
800  * handling.
801  */
802 static const struct ops {
803 	eval_fn *inner;
804 	struct op {
805 		const char *str;
806 		Linetype (*fn)(int *, Linetype, int, Linetype, int);
807 	} op[5];
808 } eval_ops[] = {
809 	{ eval_table, { { "||", op_or } } },
810 	{ eval_table, { { "&&", op_and } } },
811 	{ eval_table, { { "==", op_eq },
812 			{ "!=", op_ne } } },
813 	{ eval_unary, { { "<=", op_le },
814 			{ ">=", op_ge },
815 			{ "<", op_lt },
816 			{ ">", op_gt } } }
817 };
818 
819 /*
820  * Function for evaluating the innermost parts of expressions,
821  * viz. !expr (expr) number defined(symbol) symbol
822  * We reset the constexpr flag in the last two cases.
823  */
824 static Linetype
eval_unary(const struct ops * ops,int * valp,const char ** cpp)825 eval_unary(const struct ops *ops, int *valp, const char **cpp)
826 {
827 	const char *cp;
828 	char *ep;
829 	int sym;
830 	bool defparen;
831 	Linetype lt;
832 
833 	cp = skipcomment(*cpp);
834 	if (*cp == '!') {
835 		debug("eval%d !", ops - eval_ops);
836 		cp++;
837 		lt = eval_unary(ops, valp, &cp);
838 		if (lt == LT_ERROR)
839 			return (LT_ERROR);
840 		if (lt != LT_IF) {
841 			*valp = !*valp;
842 			lt = *valp ? LT_TRUE : LT_FALSE;
843 		}
844 	} else if (*cp == '(') {
845 		cp++;
846 		debug("eval%d (", ops - eval_ops);
847 		lt = eval_table(eval_ops, valp, &cp);
848 		if (lt == LT_ERROR)
849 			return (LT_ERROR);
850 		cp = skipcomment(cp);
851 		if (*cp++ != ')')
852 			return (LT_ERROR);
853 	} else if (isdigit((unsigned char)*cp)) {
854 		debug("eval%d number", ops - eval_ops);
855 		*valp = strtol(cp, &ep, 0);
856 		if (ep == cp)
857 			return (LT_ERROR);
858 		lt = *valp ? LT_TRUE : LT_FALSE;
859 		cp = skipsym(cp);
860 	} else if (strncmp(cp, "defined", 7) == 0 && endsym(cp[7])) {
861 		cp = skipcomment(cp+7);
862 		debug("eval%d defined", ops - eval_ops);
863 		if (*cp == '(') {
864 			cp = skipcomment(cp+1);
865 			defparen = true;
866 		} else {
867 			defparen = false;
868 		}
869 		sym = findsym(cp);
870 		if (sym < 0) {
871 			lt = LT_IF;
872 		} else {
873 			*valp = (value[sym] != NULL);
874 			lt = *valp ? LT_TRUE : LT_FALSE;
875 		}
876 		cp = skipsym(cp);
877 		cp = skipcomment(cp);
878 		if (defparen && *cp++ != ')')
879 			return (LT_ERROR);
880 		constexpr = false;
881 	} else if (!endsym(*cp)) {
882 		debug("eval%d symbol", ops - eval_ops);
883 		sym = findsym(cp);
884 		cp = skipsym(cp);
885 		if (sym < 0) {
886 			lt = LT_IF;
887 			cp = skipargs(cp);
888 		} else if (value[sym] == NULL) {
889 			*valp = 0;
890 			lt = LT_FALSE;
891 		} else {
892 			*valp = strtol(value[sym], &ep, 0);
893 			if (*ep != '\0' || ep == value[sym])
894 				return (LT_ERROR);
895 			lt = *valp ? LT_TRUE : LT_FALSE;
896 			cp = skipargs(cp);
897 		}
898 		constexpr = false;
899 	} else {
900 		debug("eval%d bad expr", ops - eval_ops);
901 		return (LT_ERROR);
902 	}
903 
904 	*cpp = cp;
905 	debug("eval%d = %d", ops - eval_ops, *valp);
906 	return (lt);
907 }
908 
909 /*
910  * Table-driven evaluation of binary operators.
911  */
912 static Linetype
eval_table(const struct ops * ops,int * valp,const char ** cpp)913 eval_table(const struct ops *ops, int *valp, const char **cpp)
914 {
915 	const struct op *op;
916 	const char *cp;
917 	int val;
918 	Linetype lt, rt;
919 
920 	debug("eval%d", ops - eval_ops);
921 	cp = *cpp;
922 	lt = ops->inner(ops+1, valp, &cp);
923 	if (lt == LT_ERROR)
924 		return (LT_ERROR);
925 	for (;;) {
926 		cp = skipcomment(cp);
927 		for (op = ops->op; op->str != NULL; op++)
928 			if (strncmp(cp, op->str, strlen(op->str)) == 0)
929 				break;
930 		if (op->str == NULL)
931 			break;
932 		cp += strlen(op->str);
933 		debug("eval%d %s", ops - eval_ops, op->str);
934 		rt = ops->inner(ops+1, &val, &cp);
935 		if (rt == LT_ERROR)
936 			return (LT_ERROR);
937 		lt = op->fn(valp, lt, *valp, rt, val);
938 	}
939 
940 	*cpp = cp;
941 	debug("eval%d = %d", ops - eval_ops, *valp);
942 	debug("eval%d lt = %s", ops - eval_ops, linetype_name[lt]);
943 	return (lt);
944 }
945 
946 /*
947  * Evaluate the expression on a #if or #elif line. If we can work out
948  * the result we return LT_TRUE or LT_FALSE accordingly, otherwise we
949  * return just a generic LT_IF.
950  */
951 static Linetype
ifeval(const char ** cpp)952 ifeval(const char **cpp)
953 {
954 	int ret;
955 	int val = 0;
956 
957 	debug("eval %s", *cpp);
958 	constexpr = killconsts ? false : true;
959 	ret = eval_table(eval_ops, &val, cpp);
960 	debug("eval = %d", val);
961 	return (constexpr ? LT_IF : ret == LT_ERROR ? LT_IF : ret);
962 }
963 
964 /*
965  * Skip over comments, strings, and character literals and stop at the
966  * next character position that is not whitespace. Between calls we keep
967  * the comment state in the global variable incomment, and we also adjust
968  * the global variable linestate when we see a newline.
969  * XXX: doesn't cope with the buffer splitting inside a state transition.
970  */
971 static const char *
skipcomment(const char * cp)972 skipcomment(const char *cp)
973 {
974 	if (text || ignoring[depth]) {
975 		for (; isspace((unsigned char)*cp); cp++)
976 			if (*cp == '\n')
977 				linestate = LS_START;
978 		return (cp);
979 	}
980 	while (*cp != '\0')
981 		/* don't reset to LS_START after a line continuation */
982 		if (strncmp(cp, "\\\r\n", 3) == 0)
983 			cp += 3;
984 		else if (strncmp(cp, "\\\n", 2) == 0)
985 			cp += 2;
986 		else switch (incomment) {
987 		case NO_COMMENT:
988 			if (strncmp(cp, "/\\\r\n", 4) == 0) {
989 				incomment = STARTING_COMMENT;
990 				cp += 4;
991 			} else if (strncmp(cp, "/\\\n", 3) == 0) {
992 				incomment = STARTING_COMMENT;
993 				cp += 3;
994 			} else if (strncmp(cp, "/*", 2) == 0) {
995 				incomment = C_COMMENT;
996 				cp += 2;
997 			} else if (strncmp(cp, "//", 2) == 0) {
998 				incomment = CXX_COMMENT;
999 				cp += 2;
1000 			} else if (strncmp(cp, "\'", 1) == 0) {
1001 				incomment = CHAR_LITERAL;
1002 				linestate = LS_DIRTY;
1003 				cp += 1;
1004 			} else if (strncmp(cp, "\"", 1) == 0) {
1005 				incomment = STRING_LITERAL;
1006 				linestate = LS_DIRTY;
1007 				cp += 1;
1008 			} else if (strncmp(cp, "\n", 1) == 0) {
1009 				linestate = LS_START;
1010 				cp += 1;
1011 			} else if (strchr(" \r\t", *cp) != NULL) {
1012 				cp += 1;
1013 			} else
1014 				return (cp);
1015 			continue;
1016 		case CXX_COMMENT:
1017 			if (strncmp(cp, "\n", 1) == 0) {
1018 				incomment = NO_COMMENT;
1019 				linestate = LS_START;
1020 			}
1021 			cp += 1;
1022 			continue;
1023 		case CHAR_LITERAL:
1024 		case STRING_LITERAL:
1025 			if ((incomment == CHAR_LITERAL && cp[0] == '\'') ||
1026 			    (incomment == STRING_LITERAL && cp[0] == '\"')) {
1027 				incomment = NO_COMMENT;
1028 				cp += 1;
1029 			} else if (cp[0] == '\\') {
1030 				if (cp[1] == '\0')
1031 					cp += 1;
1032 				else
1033 					cp += 2;
1034 			} else if (strncmp(cp, "\n", 1) == 0) {
1035 				if (incomment == CHAR_LITERAL)
1036 					error("unterminated char literal");
1037 				else
1038 					error("unterminated string literal");
1039 			} else
1040 				cp += 1;
1041 			continue;
1042 		case C_COMMENT:
1043 			if (strncmp(cp, "*\\\r\n", 4) == 0) {
1044 				incomment = FINISHING_COMMENT;
1045 				cp += 4;
1046 			} else if (strncmp(cp, "*\\\n", 3) == 0) {
1047 				incomment = FINISHING_COMMENT;
1048 				cp += 3;
1049 			} else if (strncmp(cp, "*/", 2) == 0) {
1050 				incomment = NO_COMMENT;
1051 				cp += 2;
1052 			} else
1053 				cp += 1;
1054 			continue;
1055 		case STARTING_COMMENT:
1056 			if (*cp == '*') {
1057 				incomment = C_COMMENT;
1058 				cp += 1;
1059 			} else if (*cp == '/') {
1060 				incomment = CXX_COMMENT;
1061 				cp += 1;
1062 			} else {
1063 				incomment = NO_COMMENT;
1064 				linestate = LS_DIRTY;
1065 			}
1066 			continue;
1067 		case FINISHING_COMMENT:
1068 			if (*cp == '/') {
1069 				incomment = NO_COMMENT;
1070 				cp += 1;
1071 			} else
1072 				incomment = C_COMMENT;
1073 			continue;
1074 		default:
1075 			abort(); /* bug */
1076 		}
1077 	return (cp);
1078 }
1079 
1080 /*
1081  * Skip macro arguments.
1082  */
1083 static const char *
skipargs(const char * cp)1084 skipargs(const char *cp)
1085 {
1086 	const char *ocp = cp;
1087 	int level = 0;
1088 	cp = skipcomment(cp);
1089 	if (*cp != '(')
1090 		return (cp);
1091 	do {
1092 		if (*cp == '(')
1093 			level++;
1094 		if (*cp == ')')
1095 			level--;
1096 		cp = skipcomment(cp+1);
1097 	} while (level != 0 && *cp != '\0');
1098 	if (level == 0)
1099 		return (cp);
1100 	else
1101 	/* Rewind and re-detect the syntax error later. */
1102 		return (ocp);
1103 }
1104 
1105 /*
1106  * Skip over an identifier.
1107  */
1108 static const char *
skipsym(const char * cp)1109 skipsym(const char *cp)
1110 {
1111 	while (!endsym(*cp))
1112 		++cp;
1113 	return (cp);
1114 }
1115 
1116 /*
1117  * Look for the symbol in the symbol table. If it is found, we return
1118  * the symbol table index, else we return -1.
1119  */
1120 static int
findsym(const char * str)1121 findsym(const char *str)
1122 {
1123 	const char *cp;
1124 	int symind;
1125 
1126 	cp = skipsym(str);
1127 	if (cp == str)
1128 		return (-1);
1129 	if (symlist) {
1130 		if (symdepth && firstsym)
1131 			printf("%s%3d", zerosyms ? "" : "\n", depth);
1132 		firstsym = zerosyms = false;
1133 		printf("%s%.*s%s",
1134 		    symdepth ? " " : "",
1135 		    (int)(cp-str), str,
1136 		    symdepth ? "" : "\n");
1137 		/* we don't care about the value of the symbol */
1138 		return (0);
1139 	}
1140 	for (symind = 0; symind < nsyms; ++symind) {
1141 		if (strlcmp(symname[symind], str, cp-str) == 0) {
1142 			debug("findsym %s %s", symname[symind],
1143 			    value[symind] ? value[symind] : "");
1144 			return (symind);
1145 		}
1146 	}
1147 	return (-1);
1148 }
1149 
1150 /*
1151  * Add a symbol to the symbol table.
1152  */
1153 static void
addsym(bool ignorethis,bool definethis,char * sym)1154 addsym(bool ignorethis, bool definethis, char *sym)
1155 {
1156 	int symind;
1157 	char *val;
1158 
1159 	symind = findsym(sym);
1160 	if (symind < 0) {
1161 		if (nsyms >= MAXSYMS)
1162 			errx(2, "too many symbols");
1163 		symind = nsyms++;
1164 	}
1165 	symname[symind] = sym;
1166 	ignore[symind] = ignorethis;
1167 	val = sym + (skipsym(sym) - sym);
1168 	if (definethis) {
1169 		if (*val == '=') {
1170 			value[symind] = val+1;
1171 			*val = '\0';
1172 		} else if (*val == '\0')
1173 			value[symind] = "1";
1174 		else
1175 			usage();
1176 	} else {
1177 		if (*val != '\0')
1178 			usage();
1179 		value[symind] = NULL;
1180 	}
1181 	debug("addsym %s=%s", symname[symind],
1182 	    value[symind] ? value[symind] : "undef");
1183 }
1184 
1185 /*
1186  * Compare s with n characters of t.
1187  * The same as strncmp() except that it checks that s[n] == '\0'.
1188  */
1189 static int
strlcmp(const char * s,const char * t,size_t n)1190 strlcmp(const char *s, const char *t, size_t n)
1191 {
1192 	while (n-- && *t != '\0')
1193 		if (*s != *t)
1194 			return ((unsigned char)*s - (unsigned char)*t);
1195 		else
1196 			++s, ++t;
1197 	return ((unsigned char)*s);
1198 }
1199 
1200 /*
1201  * Diagnostics.
1202  */
1203 static void
debug(const char * msg,...)1204 debug(const char *msg, ...)
1205 {
1206 	va_list ap;
1207 
1208 	if (debugging) {
1209 		va_start(ap, msg);
1210 		vwarnx(msg, ap);
1211 		va_end(ap);
1212 	}
1213 }
1214 
1215 static void
error(const char * msg)1216 error(const char *msg)
1217 {
1218 	if (depth == 0)
1219 		warnx("%s: %d: %s", filename, linenum, msg);
1220 	else
1221 		warnx("%s: %d: %s (#if line %d depth %d)",
1222 		    filename, linenum, msg, stifline[depth], depth);
1223 	closeout();
1224 	errx(2, "output may be truncated");
1225 }
1226