aboutsummaryrefslogtreecommitdiff
path: root/scripts/mkdep.c
blob: ae3cc74e032decb76651e4997e2b01ef07b9deeb (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
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
/*
 * Originally by Linus Torvalds.
 * Smart CONFIG_* processing by Werner Almesberger, Michael Chastain.
 *
 * Usage: mkdep cflags -- file ...
 *
 * Read source files and output makefile dependency lines for them.
 * I make simple dependency lines for #include <*.h> and #include "*.h".
 * I also find instances of CONFIG_FOO and generate dependencies
 *    like include/config/foo.h.
 *
 * 1 August 1999, Michael Elizabeth Chastain, <mec@shout.net>
 * - Keith Owens reported a bug in smart config processing.  There used
 *   to be an optimization for "#define CONFIG_FOO ... #ifdef CONFIG_FOO",
 *   so that the file would not depend on CONFIG_FOO because the file defines
 *   this symbol itself.  But this optimization is bogus!  Consider this code:
 *   "#if 0 \n #define CONFIG_FOO \n #endif ... #ifdef CONFIG_FOO".  Here
 *   the definition is inactivated, but I still used it.  It turns out this
 *   actually happens a few times in the kernel source.  The simple way to
 *   fix this problem is to remove this particular optimization.
 *
 * 2.3.99-pre1, Andrew Morton <andrewm@uow.edu.au>
 * - Changed so that 'filename.o' depends upon 'filename.[cS]'.  This is so that
 *   missing source files are noticed, rather than silently ignored.
 *
 * 2.4.2-pre3, Keith Owens <kaos@ocs.com.au>
 * - Accept cflags followed by '--' followed by filenames.  mkdep extracts -I
 *   options from cflags and looks in the specified directories as well as the
 *   defaults.   Only -I is supported, no attempt is made to handle -idirafter,
 *   -isystem, -I- etc.
 */

#include <ctype.h>
#include <fcntl.h>
#include <limits.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>

#include <sys/fcntl.h>
#include <sys/mman.h>
#include <sys/stat.h>
#include <sys/types.h>



char depname[512];
int hasdep;

struct path_struct {
	int len;
	char *buffer;
};
struct path_struct *path_array;
int paths;


/* Current input file */
static const char *g_filename;

/*
 * This records all the configuration options seen.
 * In perl this would be a hash, but here it's a long string
 * of values separated by newlines.  This is simple and
 * extremely fast.
 */
char * str_config  = NULL;
int    size_config = 0;
int    len_config  = 0;

static void
do_depname(void)
{
	if (!hasdep) {
		hasdep = 1;
		if (g_filename) {
			/* Source file (*.[cS]) */
			printf("%s:", depname);
			printf(" %s", g_filename);
		} else {
			/* header file (*.h) */
			printf("dep_%s +=", depname);
		}
	}
}

/*
 * Grow the configuration string to a desired length.
 * Usually the first growth is plenty.
 */
void grow_config(int len)
{
	while (len_config + len > size_config) {
		if (size_config == 0)
			size_config = 2048;
		str_config = realloc(str_config, size_config *= 2);
		if (str_config == NULL)
			{ perror("malloc config"); exit(1); }
	}
}



/*
 * Lookup a value in the configuration string.
 */
int is_defined_config(const char * name, int len)
{
	const char * pconfig;
	const char * plast = str_config + len_config - len;
	for ( pconfig = str_config + 1; pconfig < plast; pconfig++ ) {
		if (pconfig[ -1] == '\n'
		&&  pconfig[len] == '\n'
		&&  !memcmp(pconfig, name, len))
			return 1;
	}
	return 0;
}



/*
 * Add a new value to the configuration string.
 */
void define_config(const char * name, int len)
{
	grow_config(len + 1);

	memcpy(str_config+len_config, name, len);
	len_config += len;
	str_config[len_config++] = '\n';
}



/*
 * Clear the set of configuration strings.
 */
void clear_config(void)
{
	len_config = 0;
	define_config("", 0);
}



/*
 * This records all the precious .h filenames.  No need for a hash,
 * it's a long string of values enclosed in tab and newline.
 */
char * str_precious  = NULL;
int    size_precious = 0;
int    len_precious  = 0;



/*
 * Grow the precious string to a desired length.
 * Usually the first growth is plenty.
 */
void grow_precious(int len)
{
	while (len_precious + len > size_precious) {
		if (size_precious == 0)
			size_precious = 2048;
		str_precious = realloc(str_precious, size_precious *= 2);
		if (str_precious == NULL)
			{ perror("malloc"); exit(1); }
	}
}



/*
 * Add a new value to the precious string.
 */
void define_precious(const char * filename)
{
	int len = strlen(filename);
	grow_precious(len + 4);
	*(str_precious+len_precious++) = '\t';
	memcpy(str_precious+len_precious, filename, len);
	len_precious += len;
	memcpy(str_precious+len_precious, " \\\n", 3);
	len_precious += 3;
}



/*
 * Handle an #include line.
 */
void handle_include(int start, const char * name, int len)
{
	struct path_struct *path;
	int i;

	if (len == 14 && !memcmp(name, "include/config.h", len))
		return;

	if (len >= 7 && !memcmp(name, "config/", 7))
		define_config(name+7, len-7-2);

	for (i = start, path = path_array+start; i < paths; ++i, ++path) {
		memcpy(path->buffer+path->len, name, len);
		path->buffer[path->len+len] = '\0';
		if (access(path->buffer, F_OK) == 0) {
			do_depname();
			printf(" \\\n %s $(dep_%s)", path->buffer, path->buffer);
			return;
		}
	}

}



/*
 * Add a path to the list of include paths.
 */
void add_path(const char * name)
{
	struct path_struct *path;
	char resolved_path[PATH_MAX+1];
	const char *name2;

	if (strcmp(name, ".")) {
		name2 = realpath(name, resolved_path);
		if (!name2) {
			fprintf(stderr, "realpath(%s) failed, %m\n", name);
			exit(1);
		}
	}
	else {
		name2 = "";
	}

	path_array = realloc(path_array, (++paths)*sizeof(*path_array));
	if (!path_array) {
		fprintf(stderr, "cannot expand path_arry\n");
		exit(1);
	}

	path = path_array+paths-1;
	path->len = strlen(name2);
	path->buffer = malloc(path->len+1+256+1);
	if (!path->buffer) {
		fprintf(stderr, "cannot allocate path buffer\n");
		exit(1);
	}
	strcpy(path->buffer, name2);
	if (path->len && *(path->buffer+path->len-1) != '/') {
		*(path->buffer+path->len) = '/';
		*(path->buffer+(++(path->len))) = '\0';
	}
}



/*
 * Record the use of a CONFIG_* word.
 */
void use_config(const char * name, int len)
{
	char *pc;
	int i;

	pc = path_array[paths-1].buffer + path_array[paths-1].len;
	memcpy(pc, "config/", 7);
	pc += 7;

	for (i = 0; i < len; i++) {
	    char c = name[i];
	    if (isupper((int)c)) c = tolower((int)c);
	    if (c == '_')   c = '/';
	    pc[i] = c;
	}
	pc[len] = '\0';

	if (is_defined_config(pc, len))
	    return;

	define_config(pc, len);

	do_depname();
	printf(" \\\n   $(wildcard %s.h)", path_array[paths-1].buffer);
}



/*
 * Macros for stunningly fast map-based character access.
 * __buf is a register which holds the current word of the input.
 * Thus, there is one memory access per sizeof(unsigned long) characters.
 */

#if defined(__alpha__) || defined(__i386__) || defined(__ia64__)  || defined(__x86_64__) || defined(__MIPSEL__)	\
    || defined(__arm__)
#define LE_MACHINE
#endif

#ifdef LE_MACHINE
#define next_byte(x) (x >>= 8)
#define current ((unsigned char) __buf)
#else
#define next_byte(x) (x <<= 8)
#define current (__buf >> 8*(sizeof(unsigned long)-1))
#endif

#define GETNEXT { \
	next_byte(__buf); \
	if ((unsigned long) next % sizeof(unsigned long) == 0) { \
		if (next >= end) \
			break; \
		__buf = * (unsigned long *) next; \
	} \
	next++; \
}

/*
 * State machine macros.
 */
#define CASE(c,label) if (current == c) goto label
#define NOTCASE(c,label) if (current != c) goto label

/*
 * Yet another state machine speedup.
 */
#define MAX2(a,b) ((a)>(b)?(a):(b))
#define MIN2(a,b) ((a)<(b)?(a):(b))
#define MAX5(a,b,c,d,e) (MAX2(a,MAX2(b,MAX2(c,MAX2(d,e)))))
#define MIN5(a,b,c,d,e) (MIN2(a,MIN2(b,MIN2(c,MIN2(d,e)))))



/*
 * The state machine looks for (approximately) these Perl regular expressions:
 *
 *    m|\/\*.*?\*\/|
 *    m|\/\/.*|
 *    m|'.*?'|
 *    m|".*?"|
 *    m|#\s*include\s*"(.*?)"|
 *    m|#\s*include\s*<(.*?>"|
 *    m|#\s*(?define|undef)\s*CONFIG_(\w*)|
 *    m|(?!\w)CONFIG_|
 *
 * About 98% of the CPU time is spent here, and most of that is in
 * the 'start' paragraph.  Because the current characters are
 * in a register, the start loop usually eats 4 or 8 characters
 * per memory read.  The MAX5 and MIN5 tests dispose of most
 * input characters with 1 or 2 comparisons.
 */
void state_machine(const char * map, const char * end)
{
	const char * next = map;
	const char * map_dot;
	unsigned long __buf = 0;

	for (;;) {
start:
	GETNEXT
__start:
	if (current > MAX5('/','\'','"','#','C')) goto start;
	if (current < MIN5('/','\'','"','#','C')) goto start;
	CASE('/',  slash);
	CASE('\'', squote);
	CASE('"',  dquote);
	CASE('#',  pound);
	CASE('C',  cee);
	goto start;

/* // */
slash_slash:
	GETNEXT
	CASE('\n', start);
	NOTCASE('\\', slash_slash);
	GETNEXT
	goto slash_slash;

/* / */
slash:
	GETNEXT
	CASE('/',  slash_slash);
	NOTCASE('*', __start);
slash_star_dot_star:
	GETNEXT
__slash_star_dot_star:
	NOTCASE('*', slash_star_dot_star);
	GETNEXT
	NOTCASE('/', __slash_star_dot_star);
	goto start;

/* '.*?' */
squote:
	GETNEXT
	CASE('\'', start);
	NOTCASE('\\', squote);
	GETNEXT
	goto squote;

/* ".*?" */
dquote:
	GETNEXT
	CASE('"', start);
	NOTCASE('\\', dquote);
	GETNEXT
	goto dquote;

/* #\s* */
pound:
	GETNEXT
	CASE(' ',  pound);
	CASE('\t', pound);
	CASE('i',  pound_i);
	CASE('d',  pound_d);
	CASE('u',  pound_u);
	goto __start;

/* #\s*i */
pound_i:
	GETNEXT NOTCASE('n', __start);
	GETNEXT NOTCASE('c', __start);
	GETNEXT NOTCASE('l', __start);
	GETNEXT NOTCASE('u', __start);
	GETNEXT NOTCASE('d', __start);
	GETNEXT NOTCASE('e', __start);
	goto pound_include;

/* #\s*include\s* */
pound_include:
	GETNEXT
	CASE(' ',  pound_include);
	CASE('\t', pound_include);
	map_dot = next;
	CASE('"',  pound_include_dquote);
	CASE('<',  pound_include_langle);
	goto __start;

/* #\s*include\s*"(.*)" */
pound_include_dquote:
	GETNEXT
	CASE('\n', start);
	NOTCASE('"', pound_include_dquote);
	handle_include(0, map_dot, next - map_dot - 1);
	goto start;

/* #\s*include\s*<(.*)> */
pound_include_langle:
	GETNEXT
	CASE('\n', start);
	NOTCASE('>', pound_include_langle);
	handle_include(1, map_dot, next - map_dot - 1);
	goto start;

/* #\s*d */
pound_d:
	GETNEXT NOTCASE('e', __start);
	GETNEXT NOTCASE('f', __start);
	GETNEXT NOTCASE('i', __start);
	GETNEXT NOTCASE('n', __start);
	GETNEXT NOTCASE('e', __start);
	goto pound_define_undef;

/* #\s*u */
pound_u:
	GETNEXT NOTCASE('n', __start);
	GETNEXT NOTCASE('d', __start);
	GETNEXT NOTCASE('e', __start);
	GETNEXT NOTCASE('f', __start);
	goto pound_define_undef;

/*
 * #\s*(define|undef)\s*CONFIG_(\w*)
 *
 * this does not define the word, because it could be inside another
 * conditional (#if 0).  But I do parse the word so that this instance
 * does not count as a use.  -- mec
 */
pound_define_undef:
	GETNEXT
	CASE(' ',  pound_define_undef);
	CASE('\t', pound_define_undef);

	        NOTCASE('C', __start);
	GETNEXT NOTCASE('O', __start);
	GETNEXT NOTCASE('N', __start);
	GETNEXT NOTCASE('F', __start);
	GETNEXT NOTCASE('I', __start);
	GETNEXT NOTCASE('G', __start);
	GETNEXT NOTCASE('_', __start);

	map_dot = next;
pound_define_undef_CONFIG_word:
	GETNEXT
	if (isalnum(current) || current == '_')
		goto pound_define_undef_CONFIG_word;
	goto __start;

/* \<CONFIG_(\w*) */
cee:
	if (next >= map+2 && (isalnum((int)next[-2]) || next[-2] == '_'))
		goto start;
	GETNEXT NOTCASE('O', __start);
	GETNEXT NOTCASE('N', __start);
	GETNEXT NOTCASE('F', __start);
	GETNEXT NOTCASE('I', __start);
	GETNEXT NOTCASE('G', __start);
	GETNEXT NOTCASE('_', __start);

	map_dot = next;
cee_CONFIG_word:
	GETNEXT
	if (isalnum(current) || current == '_')
		goto cee_CONFIG_word;
	use_config(map_dot, next - map_dot - 1);
	goto __start;
    }
}



/*
 * Generate dependencies for one file.
 */
void do_depend(const char * filename)
{
	int mapsize;
	int pagesizem1 = getpagesize()-1;
	int fd;
	struct stat st;
	char * map;

	fd = open(filename, O_RDONLY);
	if (fd < 0) {
		perror(filename);
		return;
	}

	fstat(fd, &st);
	if (st.st_size == 0) {
		fprintf(stderr,"%s is empty\n",filename);
		close(fd);
		return;
	}

	mapsize = st.st_size;
	mapsize = (mapsize+pagesizem1) & ~pagesizem1;
	map = mmap(NULL, mapsize, PROT_READ, MAP_PRIVATE, fd, 0);
	if ((long) map == -1) {
		perror("mkdep: mmap");
		close(fd);
		return;
	}
	if ((unsigned long) map % sizeof(unsigned long) != 0)
	{
		fprintf(stderr, "do_depend: map not aligned\n");
		exit(1);
	}

	hasdep = 0;
	clear_config();
	state_machine(map, map+st.st_size);
	if (hasdep) {
		puts("");
	}

	munmap(map, mapsize);
	close(fd);
}



/*
 * Generate dependencies for all files.
 */
int main(int argc, char **argv)
{
	int len;
	const char *hpath;

	hpath = getenv("TOPDIR");
	if (!hpath) {
		fputs("mkdep: TOPDIR not set in environment.  "
		      "Don't bypass the top level Makefile.\n", stderr);
		return 1;
	}

	add_path(".");		/* for #include "..." */

	while (++argv, --argc > 0) {
		if (strncmp(*argv, "-I", 2) == 0) {
			if (*((*argv)+2)) {
				add_path((*argv)+2);
			}
			else {
				++argv;
				--argc;
				add_path(*argv);
			}
		}
		else if (strcmp(*argv, "--") == 0) {
			break;
		}
	}

	add_path(hpath);	/* must be last entry, for config files */

	while (--argc > 0) {
		const char * filename = *++argv;
		g_filename = 0;
		len = strlen(filename);
		memcpy(depname, filename, len+1);
		if (len > 2 && filename[len-2] == '.') {
			if (filename[len-1] == 'c' || filename[len-1] == 'S') {
			    depname[len-1] = 'o';
			    g_filename = filename;
			}
		}
		do_depend(filename);
	}
	if (len_precious) {
		*(str_precious+len_precious) = '\0';
		printf(".PRECIOUS:%s\n", str_precious);
	}
	return 0;
}