source: trunk/essentials/sys-apps/gawk/ansi2knr.c@ 3893

Last change on this file since 3893 was 3076, checked in by bird, 19 years ago

gawk 3.1.5
File size: 19.8 KB
Line 
1/* Copyright (C) 1989, 2000 Aladdin Enterprises. All rights reserved. */
2
3/*$Id: ansi2knr.c,v 1.3 2000/04/13 03:41:48 lpd Exp $*/
4/* Convert ANSI C function definitions to K&R ("traditional C") syntax */
5
6/*
7ansi2knr is distributed in the hope that it will be useful, but WITHOUT ANY
8WARRANTY. No author or distributor accepts responsibility to anyone for the
9consequences of using it or for whether it serves any particular purpose or
10works at all, unless he says so in writing. Refer to the GNU General Public
11License (the "GPL") for full details.
12
13Everyone is granted permission to copy, modify and redistribute ansi2knr,
14but only under the conditions described in the GPL. A copy of this license
15is supposed to have been given to you along with ansi2knr so you can know
16your rights and responsibilities. It should be in a file named COPYLEFT,
17or, if there is no file named COPYLEFT, a file named COPYING. Among other
18things, the copyright notice and this notice must be preserved on all
19copies.
20
21We explicitly state here what we believe is already implied by the GPL: if
22the ansi2knr program is distributed as a separate set of sources and a
23separate executable file which are aggregated on a storage medium together
24with another program, this in itself does not bring the other program under
25the GPL, nor does the mere fact that such a program or the procedures for
26constructing it invoke the ansi2knr executable bring any other part of the
27program under the GPL.
28*/
29
30/*
31 * Usage:
32 ansi2knr [--filename FILENAME] [INPUT_FILE [OUTPUT_FILE]]
33 * --filename provides the file name for the #line directive in the output,
34 * overriding input_file (if present).
35 * If no input_file is supplied, input is read from stdin.
36 * If no output_file is supplied, output goes to stdout.
37 * There are no error messages.
38 *
39 * ansi2knr recognizes function definitions by seeing a non-keyword
40 * identifier at the left margin, followed by a left parenthesis, with a
41 * right parenthesis as the last character on the line, and with a left
42 * brace as the first token on the following line (ignoring possible
43 * intervening comments and/or preprocessor directives), except that a line
44 * consisting of only
45 * identifier1(identifier2)
46 * will not be considered a function definition unless identifier2 is
47 * the word "void", and a line consisting of
48 * identifier1(identifier2, <<arbitrary>>)
49 * will not be considered a function definition.
50 * ansi2knr will recognize a multi-line header provided that no intervening
51 * line ends with a left or right brace or a semicolon. These algorithms
52 * ignore whitespace, comments, and preprocessor directives, except that
53 * the function name must be the first thing on the line. The following
54 * constructs will confuse it:
55 * - Any other construct that starts at the left margin and
56 * follows the above syntax (such as a macro or function call).
57 * - Some macros that tinker with the syntax of function headers.
58 */
59
60/*
61 * The original and principal author of ansi2knr is L. Peter Deutsch
62 * <ghost@aladdin.com>. Other authors are noted in the change history
63 * that follows (in reverse chronological order):
64
65 lpd 2000-04-12 backs out Eggert's changes because of bugs:
66 - concatlits didn't declare the type of its bufend argument;
67 - concatlits didn't recognize when it was inside a comment;
68 - scanstring could scan backward past the beginning of the string; when
69 - the check for \ + newline in scanstring was unnecessary.
70
71 2000-03-05 Paul Eggert <eggert@twinsun.com>
72
73 Add support for concatenated string literals.
74 * ansi2knr.c (concatlits): New decl.
75 (main): Invoke concatlits to concatenate string literals.
76 (scanstring): Handle backslash-newline correctly. Work with
77 character constants. Fix bug when scanning backwards through
78 backslash-quote. Check for unterminated strings.
79 (convert1): Parse character constants, too.
80 (appendline, concatlits): New functions.
81 * ansi2knr.1: Document this.
82
83 lpd 1999-08-17 added code to allow preprocessor directives
84 wherever comments are allowed
85 lpd 1999-04-12 added minor fixes from Pavel Roskin
86 <pavel_roskin@geocities.com> for clean compilation with
87 gcc -W -Wall
88 lpd 1999-03-22 added hack to recognize lines consisting of
89 identifier1(identifier2, xxx) as *not* being procedures
90 lpd 1999-02-03 made indentation of preprocessor commands consistent
91 lpd 1999-01-28 fixed two bugs: a '/' in an argument list caused an
92 endless loop; quoted strings within an argument list
93 confused the parser
94 lpd 1999-01-24 added a check for write errors on the output,
95 suggested by Jim Meyering <meyering@ascend.com>
96 lpd 1998-11-09 added further hack to recognize identifier(void)
97 as being a procedure
98 lpd 1998-10-23 added hack to recognize lines consisting of
99 identifier1(identifier2) as *not* being procedures
100 lpd 1997-12-08 made input_file optional; only closes input and/or
101 output file if not stdin or stdout respectively; prints
102 usage message on stderr rather than stdout; adds
103 --filename switch (changes suggested by
104 <ceder@lysator.liu.se>)
105 lpd 1996-01-21 added code to cope with not HAVE_CONFIG_H and with
106 compilers that don't understand void, as suggested by
107 Tom Lane
108 lpd 1996-01-15 changed to require that the first non-comment token
109 on the line following a function header be a left brace,
110 to reduce sensitivity to macros, as suggested by Tom Lane
111 <tgl@sss.pgh.pa.us>
112 lpd 1995-06-22 removed #ifndefs whose sole purpose was to define
113 undefined preprocessor symbols as 0; changed all #ifdefs
114 for configuration symbols to #ifs
115 lpd 1995-04-05 changed copyright notice to make it clear that
116 including ansi2knr in a program does not bring the entire
117 program under the GPL
118 lpd 1994-12-18 added conditionals for systems where ctype macros
119 don't handle 8-bit characters properly, suggested by
120 Francois Pinard <pinard@iro.umontreal.ca>;
121 removed --varargs switch (this is now the default)
122 lpd 1994-10-10 removed CONFIG_BROKETS conditional
123 lpd 1994-07-16 added some conditionals to help GNU `configure',
124 suggested by Francois Pinard <pinard@iro.umontreal.ca>;
125 properly erase prototype args in function parameters,
126 contributed by Jim Avera <jima@netcom.com>;
127 correct error in writeblanks (it shouldn't erase EOLs)
128 lpd 1989-xx-xx original version
129 */
130
131/* Most of the conditionals here are to make ansi2knr work with */
132/* or without the GNU configure machinery. */
133
134#if HAVE_CONFIG_H
135# include <config.h>
136#endif
137
138#include <stdio.h>
139#include <ctype.h>
140
141#if HAVE_CONFIG_H
142
143/*
144 For properly autoconfiguring ansi2knr, use AC_CONFIG_HEADER(config.h).
145 This will define HAVE_CONFIG_H and so, activate the following lines.
146 */
147
148# if STDC_HEADERS || HAVE_STRING_H
149# include <string.h>
150# else
151# include <strings.h>
152# endif
153
154#else /* not HAVE_CONFIG_H */
155
156/* Otherwise do it the hard way */
157
158# ifdef BSD
159# include <strings.h>
160# else
161# ifdef VMS
162 extern int strlen(), strncmp();
163# else
164# include <string.h>
165# endif
166# endif
167
168#endif /* not HAVE_CONFIG_H */
169
170#if STDC_HEADERS
171# include <stdlib.h>
172#else
173/*
174 malloc and free should be declared in stdlib.h,
175 but if you've got a K&R compiler, they probably aren't.
176 */
177# ifdef MSDOS
178# include <malloc.h>
179# else
180# ifdef VMS
181 extern char *malloc();
182 extern void free();
183# else
184 extern char *malloc();
185 extern int free();
186# endif
187# endif
188
189#endif
190
191/* Define NULL (for *very* old compilers). */
192#ifndef NULL
193# define NULL (0)
194#endif
195
196/*
197 * The ctype macros don't always handle 8-bit characters correctly.
198 * Compensate for this here.
199 */
200#ifdef isascii
201# undef HAVE_ISASCII /* just in case */
202# define HAVE_ISASCII 1
203#else
204#endif
205#if STDC_HEADERS || !HAVE_ISASCII
206# define is_ascii(c) 1
207#else
208# define is_ascii(c) isascii(c)
209#endif
210
211#define is_space(c) (is_ascii(c) && isspace(c))
212#define is_alpha(c) (is_ascii(c) && isalpha(c))
213#define is_alnum(c) (is_ascii(c) && isalnum(c))
214
215/* Scanning macros */
216#define isidchar(ch) (is_alnum(ch) || (ch) == '_')
217#define isidfirstchar(ch) (is_alpha(ch) || (ch) == '_')
218
219/* Forward references */
220char *ppdirforward();
221char *ppdirbackward();
222char *skipspace();
223char *scanstring();
224int writeblanks();
225int test1();
226int convert1();
227
228/* The main program */
229int
230main(argc, argv)
231 int argc;
232 char *argv[];
233{ FILE *in = stdin;
234 FILE *out = stdout;
235 char *filename = 0;
236 char *program_name = argv[0];
237 char *output_name = 0;
238#define bufsize 5000 /* arbitrary size */
239 char *buf;
240 char *line;
241 char *more;
242 char *usage =
243 "Usage: ansi2knr [--filename FILENAME] [INPUT_FILE [OUTPUT_FILE]]\n";
244 /*
245 * In previous versions, ansi2knr recognized a --varargs switch.
246 * If this switch was supplied, ansi2knr would attempt to convert
247 * a ... argument to va_alist and va_dcl; if this switch was not
248 * supplied, ansi2knr would simply drop any such arguments.
249 * Now, ansi2knr always does this conversion, and we only
250 * check for this switch for backward compatibility.
251 */
252 int convert_varargs = 1;
253 int output_error;
254
255 while ( argc > 1 && argv[1][0] == '-' ) {
256 if ( !strcmp(argv[1], "--varargs") ) {
257 convert_varargs = 1;
258 argc--;
259 argv++;
260 continue;
261 }
262 if ( !strcmp(argv[1], "--filename") && argc > 2 ) {
263 filename = argv[2];
264 argc -= 2;
265 argv += 2;
266 continue;
267 }
268 fprintf(stderr, "%s: Unrecognized switch: %s\n", program_name,
269 argv[1]);
270 fprintf(stderr, usage);
271 exit(1);
272 }
273 switch ( argc )
274 {
275 default:
276 fprintf(stderr, usage);
277 exit(0);
278 case 3:
279 output_name = argv[2];
280 out = fopen(output_name, "w");
281 if ( out == NULL ) {
282 fprintf(stderr, "%s: Cannot open output file %s\n",
283 program_name, output_name);
284 exit(1);
285 }
286 /* falls through */
287 case 2:
288 in = fopen(argv[1], "r");
289 if ( in == NULL ) {
290 fprintf(stderr, "%s: Cannot open input file %s\n",
291 program_name, argv[1]);
292 exit(1);
293 }
294 if ( filename == 0 )
295 filename = argv[1];
296 /* falls through */
297 case 1:
298 break;
299 }
300 if ( filename )
301 fprintf(out, "#line 1 \"%s\"\n", filename);
302 buf = malloc(bufsize);
303 if ( buf == NULL )
304 {
305 fprintf(stderr, "Unable to allocate read buffer!\n");
306 exit(1);
307 }
308 line = buf;
309 while ( fgets(line, (unsigned)(buf + bufsize - line), in) != NULL )
310 {
311test: line += strlen(line);
312 switch ( test1(buf) )
313 {
314 case 2: /* a function header */
315 convert1(buf, out, 1, convert_varargs);
316 break;
317 case 1: /* a function */
318 /* Check for a { at the start of the next line. */
319 more = ++line;
320f: if ( line >= buf + (bufsize - 1) ) /* overflow check */
321 goto wl;
322 if ( fgets(line, (unsigned)(buf + bufsize - line), in) == NULL )
323 goto wl;
324 switch ( *skipspace(ppdirforward(more), 1) )
325 {
326 case '{':
327 /* Definitely a function header. */
328 convert1(buf, out, 0, convert_varargs);
329 fputs(more, out);
330 break;
331 case 0:
332 /* The next line was blank or a comment: */
333 /* keep scanning for a non-comment. */
334 line += strlen(line);
335 goto f;
336 default:
337 /* buf isn't a function header, but */
338 /* more might be. */
339 fputs(buf, out);
340 strcpy(buf, more);
341 line = buf;
342 goto test;
343 }
344 break;
345 case -1: /* maybe the start of a function */
346 if ( line != buf + (bufsize - 1) ) /* overflow check */
347 continue;
348 /* falls through */
349 default: /* not a function */
350wl: fputs(buf, out);
351 break;
352 }
353 line = buf;
354 }
355 if ( line != buf )
356 fputs(buf, out);
357 free(buf);
358 if ( output_name ) {
359 output_error = ferror(out);
360 output_error |= fclose(out);
361 } else { /* out == stdout */
362 fflush(out);
363 output_error = ferror(out);
364 }
365 if ( output_error ) {
366 fprintf(stderr, "%s: error writing to %s\n", program_name,
367 (output_name ? output_name : "stdout"));
368 exit(1);
369 }
370 if ( in != stdin )
371 fclose(in);
372 return 0;
373}
374
375/*
376 * Skip forward or backward over one or more preprocessor directives.
377 */
378char *
379ppdirforward(p)
380 char *p;
381{
382 for (; *p == '#'; ++p) {
383 for (; *p != '\r' && *p != '\n'; ++p)
384 if (*p == 0)
385 return p;
386 if (*p == '\r' && p[1] == '\n')
387 ++p;
388 }
389 return p;
390}
391char *
392ppdirbackward(p, limit)
393 char *p;
394 char *limit;
395{
396 char *np = p;
397
398 for (;; p = --np) {
399 if (*np == '\n' && np[-1] == '\r')
400 --np;
401 for (; np > limit && np[-1] != '\r' && np[-1] != '\n'; --np)
402 if (np[-1] == 0)
403 return np;
404 if (*np != '#')
405 return p;
406 }
407}
408
409/*
410 * Skip over whitespace, comments, and preprocessor directives,
411 * in either direction.
412 */
413char *
414skipspace(p, dir)
415 char *p;
416 int dir; /* 1 for forward, -1 for backward */
417{
418 for ( ; ; ) {
419 while ( is_space(*p) )
420 p += dir;
421 if ( !(*p == '/' && p[dir] == '*') )
422 break;
423 p += dir; p += dir;
424 while ( !(*p == '*' && p[dir] == '/') ) {
425 if ( *p == 0 )
426 return p; /* multi-line comment?? */
427 p += dir;
428 }
429 p += dir; p += dir;
430 }
431 return p;
432}
433
434/* Scan over a quoted string, in either direction. */
435char *
436scanstring(p, dir)
437 char *p;
438 int dir;
439{
440 for (p += dir; ; p += dir)
441 if (*p == '"' && p[-dir] != '\\')
442 return p + dir;
443}
444
445/*
446 * Write blanks over part of a string.
447 * Don't overwrite end-of-line characters.
448 */
449int
450writeblanks(start, end)
451 char *start;
452 char *end;
453{ char *p;
454 for ( p = start; p < end; p++ )
455 if ( *p != '\r' && *p != '\n' )
456 *p = ' ';
457 return 0;
458}
459
460/*
461 * Test whether the string in buf is a function definition.
462 * The string may contain and/or end with a newline.
463 * Return as follows:
464 * 0 - definitely not a function definition;
465 * 1 - definitely a function definition;
466 * 2 - definitely a function prototype (NOT USED);
467 * -1 - may be the beginning of a function definition,
468 * append another line and look again.
469 * The reason we don't attempt to convert function prototypes is that
470 * Ghostscript's declaration-generating macros look too much like
471 * prototypes, and confuse the algorithms.
472 */
473int
474test1(buf)
475 char *buf;
476{ char *p = buf;
477 char *bend;
478 char *endfn;
479 int contin;
480
481 if ( !isidfirstchar(*p) )
482 return 0; /* no name at left margin */
483 bend = skipspace(ppdirbackward(buf + strlen(buf) - 1, buf), -1);
484 switch ( *bend )
485 {
486 case ';': contin = 0 /*2*/; break;
487 case ')': contin = 1; break;
488 case '{': return 0; /* not a function */
489 case '}': return 0; /* not a function */
490 default: contin = -1;
491 }
492 while ( isidchar(*p) )
493 p++;
494 endfn = p;
495 p = skipspace(p, 1);
496 if ( *p++ != '(' )
497 return 0; /* not a function */
498 p = skipspace(p, 1);
499 if ( *p == ')' )
500 return 0; /* no parameters */
501 /* Check that the apparent function name isn't a keyword. */
502 /* We only need to check for keywords that could be followed */
503 /* by a left parenthesis (which, unfortunately, is most of them). */
504 { static char *words[] =
505 { "asm", "auto", "case", "char", "const", "double",
506 "extern", "float", "for", "if", "int", "long",
507 "register", "return", "short", "signed", "sizeof",
508 "static", "switch", "typedef", "unsigned",
509 "void", "volatile", "while", 0
510 };
511 char **key = words;
512 char *kp;
513 unsigned len = endfn - buf;
514
515 while ( (kp = *key) != 0 )
516 { if ( strlen(kp) == len && !strncmp(kp, buf, len) )
517 return 0; /* name is a keyword */
518 key++;
519 }
520 }
521 {
522 char *id = p;
523 int len;
524 /*
525 * Check for identifier1(identifier2) and not
526 * identifier1(void), or identifier1(identifier2, xxxx).
527 */
528
529 while ( isidchar(*p) )
530 p++;
531 len = p - id;
532 p = skipspace(p, 1);
533 if (*p == ',' ||
534 (*p == ')' && (len != 4 || strncmp(id, "void", 4)))
535 )
536 return 0; /* not a function */
537 }
538 /*
539 * If the last significant character was a ), we need to count
540 * parentheses, because it might be part of a formal parameter
541 * that is a procedure.
542 */
543 if (contin > 0) {
544 int level = 0;
545
546 for (p = skipspace(buf, 1); *p; p = skipspace(p + 1, 1))
547 level += (*p == '(' ? 1 : *p == ')' ? -1 : 0);
548 if (level > 0)
549 contin = -1;
550 }
551 return contin;
552}
553
554/* Convert a recognized function definition or header to K&R syntax. */
555int
556convert1(buf, out, header, convert_varargs)
557 char *buf;
558 FILE *out;
559 int header; /* Boolean */
560 int convert_varargs; /* Boolean */
561{ char *endfn;
562 char *p;
563 /*
564 * The breaks table contains pointers to the beginning and end
565 * of each argument.
566 */
567 char **breaks;
568 unsigned num_breaks = 2; /* for testing */
569 char **btop;
570 char **bp;
571 char **ap;
572 char *vararg = 0;
573
574 /* Pre-ANSI implementations don't agree on whether strchr */
575 /* is called strchr or index, so we open-code it here. */
576 for ( endfn = buf; *(endfn++) != '('; )
577 ;
578top: p = endfn;
579 breaks = (char **)malloc(sizeof(char *) * num_breaks * 2);
580 if ( breaks == NULL )
581 { /* Couldn't allocate break table, give up */
582 fprintf(stderr, "Unable to allocate break table!\n");
583 fputs(buf, out);
584 return -1;
585 }
586 btop = breaks + num_breaks * 2 - 2;
587 bp = breaks;
588 /* Parse the argument list */
589 do
590 { int level = 0;
591 char *lp = NULL;
592 char *rp = NULL;
593 char *end = NULL;
594
595 if ( bp >= btop )
596 { /* Filled up break table. */
597 /* Allocate a bigger one and start over. */
598 free((char *)breaks);
599 num_breaks <<= 1;
600 goto top;
601 }
602 *bp++ = p;
603 /* Find the end of the argument */
604 for ( ; end == NULL; p++ )
605 { switch(*p)
606 {
607 case ',':
608 if ( !level ) end = p;
609 break;
610 case '(':
611 if ( !level ) lp = p;
612 level++;
613 break;
614 case ')':
615 if ( --level < 0 ) end = p;
616 else rp = p;
617 break;
618 case '/':
619 if (p[1] == '*')
620 p = skipspace(p, 1) - 1;
621 break;
622 case '"':
623 p = scanstring(p, 1) - 1;
624 break;
625 default:
626 ;
627 }
628 }
629 /* Erase any embedded prototype parameters. */
630 if ( lp && rp )
631 writeblanks(lp + 1, rp);
632 p--; /* back up over terminator */
633 /* Find the name being declared. */
634 /* This is complicated because of procedure and */
635 /* array modifiers. */
636 for ( ; ; )
637 { p = skipspace(p - 1, -1);
638 switch ( *p )
639 {
640 case ']': /* skip array dimension(s) */
641 case ')': /* skip procedure args OR name */
642 { int level = 1;
643 while ( level )
644 switch ( *--p )
645 {
646 case ']': case ')':
647 level++;
648 break;
649 case '[': case '(':
650 level--;
651 break;
652 case '/':
653 if (p > buf && p[-1] == '*')
654 p = skipspace(p, -1) + 1;
655 break;
656 case '"':
657 p = scanstring(p, -1) + 1;
658 break;
659 default: ;
660 }
661 }
662 if ( *p == '(' && *skipspace(p + 1, 1) == '*' )
663 { /* We found the name being declared */
664 while ( !isidfirstchar(*p) )
665 p = skipspace(p, 1) + 1;
666 goto found;
667 }
668 break;
669 default:
670 goto found;
671 }
672 }
673found: if ( *p == '.' && p[-1] == '.' && p[-2] == '.' )
674 { if ( convert_varargs )
675 { *bp++ = "va_alist";
676 vararg = p-2;
677 }
678 else
679 { p++;
680 if ( bp == breaks + 1 ) /* sole argument */
681 writeblanks(breaks[0], p);
682 else
683 writeblanks(bp[-1] - 1, p);
684 bp--;
685 }
686 }
687 else
688 { while ( isidchar(*p) ) p--;
689 *bp++ = p+1;
690 }
691 p = end;
692 }
693 while ( *p++ == ',' );
694 *bp = p;
695 /* Make a special check for 'void' arglist */
696 if ( bp == breaks+2 )
697 { p = skipspace(breaks[0], 1);
698 if ( !strncmp(p, "void", 4) )
699 { p = skipspace(p+4, 1);
700 if ( p == breaks[2] - 1 )
701 { bp = breaks; /* yup, pretend arglist is empty */
702 writeblanks(breaks[0], p + 1);
703 }
704 }
705 }
706 /* Put out the function name and left parenthesis. */
707 p = buf;
708 while ( p != endfn ) putc(*p, out), p++;
709 /* Put out the declaration. */
710 if ( header )
711 { fputs(");", out);
712 for ( p = breaks[0]; *p; p++ )
713 if ( *p == '\r' || *p == '\n' )
714 putc(*p, out);
715 }
716 else
717 { for ( ap = breaks+1; ap < bp; ap += 2 )
718 { p = *ap;
719 while ( isidchar(*p) )
720 putc(*p, out), p++;
721 if ( ap < bp - 1 )
722 fputs(", ", out);
723 }
724 fputs(") ", out);
725 /* Put out the argument declarations */
726 for ( ap = breaks+2; ap <= bp; ap += 2 )
727 (*ap)[-1] = ';';
728 if ( vararg != 0 )
729 { *vararg = 0;
730 fputs(breaks[0], out); /* any prior args */
731 fputs("va_dcl", out); /* the final arg */
732 fputs(bp[0], out);
733 }
734 else
735 fputs(breaks[0], out);
736 }
737 free((char *)breaks);
738 return 0;
739}
Note: See TracBrowser for help on using the repository browser.