Root/scripts/unifdef.c

Source at commit cdde9cf73945d547acd3e96f9508c79e84ad0bf1 created 9 years 4 months ago.
By Maarten ter Huurne, MMC: JZ4740: Added support for CPU frequency changing
1/*
2 * Copyright (c) 2002 - 2011 Tony Finch <dot@dotat.at>
3 *
4 * Redistribution and use in source and binary forms, with or without
5 * modification, are permitted provided that the following conditions
6 * are met:
7 * 1. Redistributions of source code must retain the above copyright
8 * notice, this list of conditions and the following disclaimer.
9 * 2. Redistributions in binary form must reproduce the above copyright
10 * notice, this list of conditions and the following disclaimer in the
11 * documentation and/or other materials provided with the distribution.
12 *
13 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
14 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
15 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
16 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
17 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
18 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
19 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
20 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
21 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
22 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
23 * SUCH DAMAGE.
24 */
25
26/*
27 * unifdef - remove ifdef'ed lines
28 *
29 * This code was derived from software contributed to Berkeley by Dave Yost.
30 * It was rewritten to support ANSI C by Tony Finch. The original version
31 * of unifdef carried the 4-clause BSD copyright licence. None of its code
32 * remains in this version (though some of the names remain) so it now
33 * carries a more liberal licence.
34 *
35 * Wishlist:
36 * provide an option which will append the name of the
37 * appropriate symbol after #else's and #endif's
38 * provide an option which will check symbols after
39 * #else's and #endif's to see that they match their
40 * corresponding #ifdef or #ifndef
41 *
42 * These require better buffer handling, which would also make
43 * it possible to handle all "dodgy" directives correctly.
44 */
45
46#include <sys/types.h>
47#include <sys/stat.h>
48
49#include <ctype.h>
50#include <err.h>
51#include <errno.h>
52#include <stdarg.h>
53#include <stdbool.h>
54#include <stdio.h>
55#include <stdlib.h>
56#include <string.h>
57#include <unistd.h>
58
59const char copyright[] =
60    "@(#) $Version: unifdef-2.5 $\n"
61    "@(#) $Author: Tony Finch (dot@dotat.at) $\n"
62    "@(#) $URL: http://dotat.at/prog/unifdef $\n"
63;
64
65/* types of input lines: */
66typedef 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
85static 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 */
96typedef 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
110static 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 */
118typedef 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
128static char const * const comment_name[] = {
129    "NO", "C", "CXX", "STARTING", "FINISHING", "CHAR", "STRING"
130};
131
132/* state of preprocessor line parser */
133typedef 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
139static 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
165static bool compblank; /* -B: compress blank lines */
166static bool lnblank; /* -b: blank deleted lines */
167static bool complement; /* -c: do the complement */
168static bool debugging; /* -d: debugging reports */
169static bool iocccok; /* -e: fewer IOCCC errors */
170static bool strictlogic; /* -K: keep ambiguous #ifs */
171static bool killconsts; /* -k: eval constant #ifs */
172static bool lnnum; /* -n: add #line directives */
173static bool symlist; /* -s: output symbol list */
174static bool symdepth; /* -S: output symbol depth */
175static bool text; /* -t: this is a text file */
176
177static const char *symname[MAXSYMS]; /* symbol name */
178static const char *value[MAXSYMS]; /* -Dsym=value */
179static bool ignore[MAXSYMS]; /* -iDsym or -iUsym */
180static int nsyms; /* number of symbols */
181
182static FILE *input; /* input file pointer */
183static const char *filename; /* input file name */
184static int linenum; /* current line number */
185static FILE *output; /* output file pointer */
186static const char *ofilename; /* output file name */
187static bool overwriting; /* output overwrites input */
188static char tempname[FILENAME_MAX]; /* used when overwriting */
189
190static char tline[MAXLINE+EDITSLOP];/* input buffer plus space */
191static char *keyword; /* used for editing #elif's */
192
193static const char *newline; /* input file format */
194static const char newline_unix[] = "\n";
195static const char newline_crlf[] = "\r\n";
196
197static Comment_state incomment; /* comment parser state */
198static Line_state linestate; /* #if line parser state */
199static Ifstate ifstate[MAXDEPTH]; /* #if processor state */
200static bool ignoring[MAXDEPTH]; /* ignore comments state */
201static int stifline[MAXDEPTH]; /* start of current #if */
202static int depth; /* current #if nesting */
203static int delcount; /* count of deleted lines */
204static unsigned blankcount; /* count of blank lines */
205static unsigned blankmax; /* maximum recent blankcount */
206static bool constexpr; /* constant #if expression */
207static bool zerosyms = true; /* to format symdepth output */
208static bool firstsym; /* ditto */
209
210static int exitstat; /* program exit status */
211
212static void addsym(bool, bool, char *);
213static void closeout(void);
214static void debug(const char *, ...);
215static void done(void);
216static void error(const char *);
217static int findsym(const char *);
218static void flushline(bool);
219static Linetype parseline(void);
220static Linetype ifeval(const char **);
221static void ignoreoff(void);
222static void ignoreon(void);
223static void keywordedit(const char *);
224static void nest(void);
225static void process(void);
226static const char *skipargs(const char *);
227static const char *skipcomment(const char *);
228static const char *skipsym(const char *);
229static void state(Ifstate);
230static int strlcmp(const char *, const char *, size_t);
231static void unnest(void);
232static void usage(void);
233static void version(void);
234
235#define endsym(c) (!isalnum((unsigned char)c) && c != '_')
236
237/*
238 * The main program.
239 */
240int
241main(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
363static void
364version(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
377static void
378usage(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 strncpy() 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 */
415typedef void state_fn(void);
416
417/* report an error */
418static void Eelif (void) { error("Inappropriate #elif"); }
419static void Eelse (void) { error("Inappropriate #else"); }
420static void Eendif(void) { error("Inappropriate #endif"); }
421static void Eeof (void) { error("Premature EOF"); }
422static void Eioccc(void) { error("Obfuscated preprocessor control line"); }
423/* plain line handling */
424static void print (void) { flushline(true); }
425static void drop (void) { flushline(false); }
426/* output lacks group's start line */
427static void Strue (void) { drop(); ignoreoff(); state(IS_TRUE_PREFIX); }
428static void Sfalse(void) { drop(); ignoreoff(); state(IS_FALSE_PREFIX); }
429static void Selse (void) { drop(); state(IS_TRUE_ELSE); }
430/* print/pass this block */
431static void Pelif (void) { print(); ignoreoff(); state(IS_PASS_MIDDLE); }
432static void Pelse (void) { print(); state(IS_PASS_ELSE); }
433static void Pendif(void) { print(); unnest(); }
434/* discard this block */
435static void Dfalse(void) { drop(); ignoreoff(); state(IS_FALSE_TRAILER); }
436static void Delif (void) { drop(); ignoreoff(); state(IS_FALSE_MIDDLE); }
437static void Delse (void) { drop(); state(IS_FALSE_ELSE); }
438static void Dendif(void) { drop(); unnest(); }
439/* first line of group */
440static void Fdrop (void) { nest(); Dfalse(); }
441static void Fpass (void) { nest(); Pelif(); }
442static void Ftrue (void) { nest(); Strue(); }
443static void Ffalse(void) { nest(); Sfalse(); }
444/* variable pedantry for obfuscated lines */
445static void Oiffy (void) { if (!iocccok) Eioccc(); Fpass(); ignoreon(); }
446static void Oif (void) { if (!iocccok) Eioccc(); Fpass(); }
447static void Oelif (void) { if (!iocccok) Eioccc(); Pelif(); }
448/* ignore comments in this block */
449static void Idrop (void) { Fdrop(); ignoreon(); }
450static void Itrue (void) { Ftrue(); ignoreon(); }
451static void Ifalse(void) { Ffalse(); ignoreon(); }
452/* modify this line */
453static void Mpass (void) { strncpy(keyword, "if ", 4); Pelif(); }
454static void Mtrue (void) { keywordedit("else"); state(IS_TRUE_MIDDLE); }
455static void Melif (void) { keywordedit("endif"); state(IS_FALSE_TRAILER); }
456static void Melse (void) { keywordedit("endif"); state(IS_FALSE_ELSE); }
457
458static 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 */
507static void
508ignoreoff(void)
509{
510    if (depth == 0)
511        abort(); /* bug */
512    ignoring[depth] = ignoring[depth-1];
513}
514static void
515ignoreon(void)
516{
517    ignoring[depth] = true;
518}
519static void
520keywordedit(const char *replacement)
521{
522    snprintf(keyword, tline + sizeof(tline) - keyword,
523        "%s%s", replacement, newline);
524    print();
525}
526static void
527nest(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}
536static void
537unnest(void)
538{
539    if (depth == 0)
540        abort(); /* bug */
541    depth -= 1;
542}
543static void
544state(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 */
552static void
553flushline(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 */
583static void
584process(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 */
601static void
602closeout(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 */
620static void
621done(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 */
639static Linetype
640parseline(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 */
746static 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}
750static Linetype op_lt(int *p, Linetype at, int a, Linetype bt, int b) {
751    return op_strict(p, a < b, at, bt);
752}
753static Linetype op_gt(int *p, Linetype at, int a, Linetype bt, int b) {
754    return op_strict(p, a > b, at, bt);
755}
756static Linetype op_le(int *p, Linetype at, int a, Linetype bt, int b) {
757    return op_strict(p, a <= b, at, bt);
758}
759static Linetype op_ge(int *p, Linetype at, int a, Linetype bt, int b) {
760    return op_strict(p, a >= b, at, bt);
761}
762static Linetype op_eq(int *p, Linetype at, int a, Linetype bt, int b) {
763    return op_strict(p, a == b, at, bt);
764}
765static Linetype op_ne(int *p, Linetype at, int a, Linetype bt, int b) {
766    return op_strict(p, a != b, at, bt);
767}
768static 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}
773static 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 */
789struct ops;
790
791typedef Linetype eval_fn(const struct ops *, int *, const char **);
792
793static 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 */
802static 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 */
824static Linetype
825eval_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 */
912static Linetype
913eval_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 */
951static Linetype
952ifeval(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 */
971static const char *
972skipcomment(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 */
1083static const char *
1084skipargs(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 */
1108static const char *
1109skipsym(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 */
1120static int
1121findsym(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 */
1153static void
1154addsym(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 */
1189static int
1190strlcmp(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 */
1203static void
1204debug(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
1215static void
1216error(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

Archive Download this file



interactive