summaryrefslogtreecommitdiff
path: root/src/ansi2knr.c
blob: 9bcc4adba59d071e8d01e03de87b56ae4a552ee3 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
/* Copyright (C) 1989, 1991, 1993, 1994 Aladdin Enterprises. All rights reserved. */

/* ansi2knr.c */
/* Convert ANSI function declarations to K&R syntax */

/*
ansi2knr is distributed in the hope that it will be useful, but
WITHOUT ANY WARRANTY.  No author or distributor accepts responsibility
to anyone for the consequences of using it or for whether it serves any
particular purpose or works at all, unless he says so in writing.  Refer
to the GNU General Public License for full details.

Everyone is granted permission to copy, modify and redistribute
ansi2knr, but only under the conditions described in the GNU
General Public License.  A copy of this license is supposed to have been
given to you along with ansi2knr so you can know your rights and
responsibilities.  It should be in a file named COPYLEFT.  Among other
things, the copyright notice and this notice must be preserved on all
copies.
*/

/*
 * Usage:
	ansi2knr [--varargs] input_file [output_file]
 * If no output_file is supplied, output goes to stdout.
 * There are no error messages.
 *
 * ansi2knr recognizes function definitions by seeing a non-keyword
 * identifier at the left margin, followed by a left parenthesis,
 * with a right parenthesis as the last character on the line.
 * It will recognize a multi-line header provided that the last character
 * of the last line of the header is a right parenthesis,
 * and no intervening line ends with a left brace or a semicolon.
 * These algorithms ignore whitespace and comments, except that
 * the function name must be the first thing on the line.
 * The following constructs will confuse it:
 *	- Any other construct that starts at the left margin and
 *	    follows the above syntax (such as a macro or function call).
 *	- Macros that tinker with the syntax of the function header.
 *
 * If the --varargs switch is supplied, ansi2knr will attempt to
 * convert a ... argument to va_alist and va_dcl.  If this switch is not
 * supplied, ansi2knr will simply drop any such arguments.
 */

/*
 * The original and principal author of ansi2knr is L. Peter Deutsch
 * <ghost@aladdin.com>.  Other authors are noted in the change history
 * that follows (in reverse chronological order):
	lpd 94-10-10 removed CONFIG_BROKETS conditional
	lpd 94-07-16 added some conditionals to help GNU `configure',
		suggested by Francois Pinard <pinard@iro.umontreal.ca>;
		properly erase prototype args in function parameters,
		contributed by Jim Avera <jima@netcom.com>;
		correct error in writeblanks (it shouldn't erase EOLs)
	lpd 89-xx-xx original version
 */

/* Most of the conditionals here are to make ansi2knr work with */
/* the GNU configure machinery. */

#ifdef HAVE_CONFIG_H
# include <config.h>
#endif

#include <stdio.h>
#include <ctype.h>

#ifdef HAVE_CONFIG_H

/*
   For properly autoconfiguring ansi2knr, use AC_CONFIG_HEADER(config.h).
   This will define HAVE_CONFIG_H and so, activate the following lines.
 */

# if STDC_HEADERS || HAVE_STRING_H
#  include <string.h>
# else
#  include <strings.h>
# endif

#else /* not HAVE_CONFIG_H */

/*
   Without AC_CONFIG_HEADER, merely use <string.h> as in the original
   Ghostscript distribution.  This loses on older BSD systems.
 */

# include <string.h>

#endif /* not HAVE_CONFIG_H */

#ifdef STDC_HEADERS
# include <stdlib.h>
#else
/*
   malloc and free should be declared in stdlib.h,
   but if you've got a K&R compiler, they probably aren't.
 */
char *malloc();
void free();
#endif

/* Scanning macros */
#define isidchar(ch) (isalnum(ch) || (ch) == '_')
#define isidfirstchar(ch) (isalpha(ch) || (ch) == '_')

/* Forward references */
char *skipspace();
void writeblanks();
int test1();
int convert1();

/* The main program */
int
main(argc, argv)
    int argc;
    char *argv[];
{	FILE *in, *out;
#define bufsize 5000			/* arbitrary size */
	char *buf;
	char *line;
	int convert_varargs = 0;
	if ( argc > 1 && argv[1][0] == '-' )
	  {	if ( !strcmp(argv[1], "--varargs") )
		  {	convert_varargs = 1;
			argc--;
			argv++;
		  }
		else
		  {	fprintf(stderr, "Unrecognized switch: %s\n", argv[1]);
			exit(1);
		  }
	  }
	switch ( argc )
	   {
	default:
		printf("Usage: ansi2knr [--varargs] input_file [output_file]\n");
		exit(0);
	case 2:
		out = stdout;
		break;
	case 3:
		out = fopen(argv[2], "w");
		if ( out == NULL )
		   {	fprintf(stderr, "Cannot open output file %s\n", argv[2]);
			exit(1);
		   }
	   }
	in = fopen(argv[1], "r");
	if ( in == NULL )
	   {	fprintf(stderr, "Cannot open input file %s\n", argv[1]);
		exit(1);
	   }
	fprintf(out, "#line 1 \"%s\"\n", argv[1]);
	buf = malloc(bufsize);
	line = buf;
	while ( fgets(line, (unsigned)(buf + bufsize - line), in) != NULL )
	   {	switch ( test1(buf) )
		   {
		case 2:			/* a function header */
			convert1(buf, out, 1, convert_varargs);
			break;
		case 1:			/* a function */
			convert1(buf, out, 0, convert_varargs);
			break;
		case -1:		/* maybe the start of a function */
			line = buf + strlen(buf);
			if ( line != buf + (bufsize - 1) ) /* overflow check */
				continue;
			/* falls through */
		default:		/* not a function */
			fputs(buf, out);
			break;
		   }
		line = buf;
	   }
	if ( line != buf ) fputs(buf, out);
	free(buf);
	fclose(out);
	fclose(in);
	return 0;
}

/* Skip over space and comments, in either direction. */
char *
skipspace(p, dir)
    register char *p;
    register int dir;			/* 1 for forward, -1 for backward */
{	for ( ; ; )
	   {	while ( isspace(*p) ) p += dir;
		if ( !(*p == '/' && p[dir] == '*') ) break;
		p += dir;  p += dir;
		while ( !(*p == '*' && p[dir] == '/') )
		   {	if ( *p == 0 ) return p;	/* multi-line comment?? */
			p += dir;
		   }
		p += dir;  p += dir;
	   }
	return p;
}

/*
 * Write blanks over part of a string.
 * Don't overwrite end-of-line characters.
 */
void
writeblanks(start, end)
    char *start;
    char *end;
{	char *p;
	for ( p = start; p < end; p++ )
	  if ( *p != '\r' && *p != '\n' ) *p = ' ';
}

/*
 * Test whether the string in buf is a function definition.
 * The string may contain and/or end with a newline.
 * Return as follows:
 *	0 - definitely not a function definition;
 *	1 - definitely a function definition;
 *	2 - definitely a function prototype (NOT USED);
 *	-1 - may be the beginning of a function definition,
 *		append another line and look again.
 * The reason we don't attempt to convert function prototypes is that
 * Ghostscript's declaration-generating macros look too much like
 * prototypes, and confuse the algorithms.
 */
int
test1(buf)
    char *buf;
{	register char *p = buf;
	char *bend;
	char *endfn;
	int contin;
	if ( !isidfirstchar(*p) )
		return 0;		/* no name at left margin */
	bend = skipspace(buf + strlen(buf) - 1, -1);
	switch ( *bend )
	   {
	case ';': contin = 0 /*2*/; break;
	case ')': contin = 1; break;
	case '{': return 0;		/* not a function */
	default: contin = -1;
	   }
	while ( isidchar(*p) ) p++;
	endfn = p;
	p = skipspace(p, 1);
	if ( *p++ != '(' )
		return 0;		/* not a function */
	p = skipspace(p, 1);
	if ( *p == ')' )
		return 0;		/* no parameters */
	/* Check that the apparent function name isn't a keyword. */
	/* We only need to check for keywords that could be followed */
	/* by a left parenthesis (which, unfortunately, is most of them). */
	   {	static char *words[] =
		   {	"asm", "auto", "case", "char", "const", "double",
			"extern", "float", "for", "if", "int", "long",
			"register", "return", "short", "signed", "sizeof",
			"static", "switch", "typedef", "unsigned",
			"void", "volatile", "while", 0
		   };
		char **key = words;
		char *kp;
		int len = endfn - buf;
		while ( (kp = *key) != 0 )
		   {	if ( strlen(kp) == len && !strncmp(kp, buf, len) )
				return 0;	/* name is a keyword */
			key++;
		   }
	   }
	return contin;
}

/* Convert a recognized function definition or header to K&R syntax. */
int
convert1(buf, out, header, convert_varargs)
    char *buf;
    FILE *out;
    int header;			/* Boolean */
    int convert_varargs;	/* Boolean */
{	char *endfn;
	register char *p;
	char **breaks;
	unsigned num_breaks = 2;	/* for testing */
	char **btop;
	char **bp;
	char **ap;
	char *vararg = 0;
	/* Pre-ANSI implementations don't agree on whether strchr */
	/* is called strchr or index, so we open-code it here. */
	for ( endfn = buf; *(endfn++) != '('; ) ;
top:	p = endfn;
	breaks = (char **)malloc(sizeof(char *) * num_breaks * 2);
	if ( breaks == 0 )
	   {	/* Couldn't allocate break table, give up */
		fprintf(stderr, "Unable to allocate break table!\n");
		fputs(buf, out);
		return -1;
	   }
	btop = breaks + num_breaks * 2 - 2;
	bp = breaks;
	/* Parse the argument list */
	do
	   {	int level = 0;
		char *lp = NULL;
		char *rp;
		char *end = NULL;
		if ( bp >= btop )
		   {	/* Filled up break table. */
			/* Allocate a bigger one and start over. */
			free((char *)breaks);
			num_breaks <<= 1;
			goto top;
		   }
		*bp++ = p;
		/* Find the end of the argument */
		for ( ; end == NULL; p++ )
		   {	switch(*p)
			   {
			case ',':
				if ( !level ) end = p;
				break;
			case '(':
				if ( !level ) lp = p;
				level++;
				break;
			case ')':
				if ( --level < 0 ) end = p;
				else rp = p;
				break;
			case '/':
				p = skipspace(p, 1) - 1;
				break;
			default:
				;
			   }
		   }
		/* Erase any embedded prototype parameters. */
		if ( lp )
		  writeblanks(lp + 1, rp);
		p--;			/* back up over terminator */
		/* Find the name being declared. */
		/* This is complicated because of procedure and */
		/* array modifiers. */
		for ( ; ; )
		   {	p = skipspace(p - 1, -1);
			switch ( *p )
			   {
			case ']':	/* skip array dimension(s) */
			case ')':	/* skip procedure args OR name */
			   {	int level = 1;
				while ( level )
				 switch ( *--p )
				   {
				case ']': case ')': level++; break;
				case '[': case '(': level--; break;
				case '/': p = skipspace(p, -1) + 1; break;
				default: ;
				   }
			   }
				if ( *p == '(' && *skipspace(p + 1, 1) == '*' )
				   {	/* We found the name being declared */
					while ( !isidfirstchar(*p) )
						p = skipspace(p, 1) + 1;
					goto found;
				   }
				break;
			default: goto found;
			   }
		   }
found:		if ( *p == '.' && p[-1] == '.' && p[-2] == '.' )
		  {	if ( convert_varargs )
			  {	*bp++ = "va_alist";
				vararg = p-2;
			  }
			else
			  {	p++;
				if ( bp == breaks + 1 )	/* sole argument */
				  writeblanks(breaks[0], p);
				else
				  writeblanks(bp[-1] - 1, p);
				bp--;
			  }
		   }
		else
		   {	while ( isidchar(*p) ) p--;
			*bp++ = p+1;
		   }
		p = end;
	   }
	while ( *p++ == ',' );
	*bp = p;
	/* Make a special check for 'void' arglist */
	if ( bp == breaks+2 )
	   {	p = skipspace(breaks[0], 1);
		if ( !strncmp(p, "void", 4) )
		   {	p = skipspace(p+4, 1);
			if ( p == breaks[2] - 1 )
			   {	bp = breaks;	/* yup, pretend arglist is empty */
				writeblanks(breaks[0], p + 1);
			   }
		   }
	   }
	/* Put out the function name and left parenthesis. */
	p = buf;
	while ( p != endfn ) putc(*p, out), p++;
	/* Put out the declaration. */
	if ( header )
	  {	fputs(");", out);
		for ( p = breaks[0]; *p; p++ )
		  if ( *p == '\r' || *p == '\n' )
		    putc(*p, out);
	  }
	else
	  {	for ( ap = breaks+1; ap < bp; ap += 2 )
		  {	p = *ap;
			while ( isidchar(*p) )
			  putc(*p, out), p++;
			if ( ap < bp - 1 )
			  fputs(", ", out);
		  }
		fputs(")  ", out);
		/* Put out the argument declarations */
		for ( ap = breaks+2; ap <= bp; ap += 2 )
		  (*ap)[-1] = ';';
		if ( vararg != 0 )
		  {	*vararg = 0;
			fputs(breaks[0], out);		/* any prior args */
			fputs("va_dcl", out);		/* the final arg */
			fputs(bp[0], out);
		  }
		else
		  fputs(breaks[0], out);
	  }
	free((char *)breaks);
	return 0;
}