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v5.4
  1/*
  2 * "Optimize" a list of dependencies as spit out by gcc -MD
  3 * for the kernel build
  4 * ===========================================================================
  5 *
  6 * Author       Kai Germaschewski
  7 * Copyright    2002 by Kai Germaschewski  <kai.germaschewski@gmx.de>
  8 *
  9 * This software may be used and distributed according to the terms
 10 * of the GNU General Public License, incorporated herein by reference.
 11 *
 12 *
 13 * Introduction:
 14 *
 15 * gcc produces a very nice and correct list of dependencies which
 16 * tells make when to remake a file.
 17 *
 18 * To use this list as-is however has the drawback that virtually
 19 * every file in the kernel includes autoconf.h.
 20 *
 21 * If the user re-runs make *config, autoconf.h will be
 22 * regenerated.  make notices that and will rebuild every file which
 23 * includes autoconf.h, i.e. basically all files. This is extremely
 24 * annoying if the user just changed CONFIG_HIS_DRIVER from n to m.
 25 *
 26 * So we play the same trick that "mkdep" played before. We replace
 27 * the dependency on autoconf.h by a dependency on every config
 28 * option which is mentioned in any of the listed prerequisites.
 29 *
 30 * kconfig populates a tree in include/config/ with an empty file
 31 * for each config symbol and when the configuration is updated
 32 * the files representing changed config options are touched
 33 * which then let make pick up the changes and the files that use
 34 * the config symbols are rebuilt.
 35 *
 36 * So if the user changes his CONFIG_HIS_DRIVER option, only the objects
 37 * which depend on "include/config/his/driver.h" will be rebuilt,
 38 * so most likely only his driver ;-)
 39 *
 40 * The idea above dates, by the way, back to Michael E Chastain, AFAIK.
 41 *
 42 * So to get dependencies right, there are two issues:
 43 * o if any of the files the compiler read changed, we need to rebuild
 44 * o if the command line given to the compile the file changed, we
 45 *   better rebuild as well.
 46 *
 47 * The former is handled by using the -MD output, the later by saving
 48 * the command line used to compile the old object and comparing it
 49 * to the one we would now use.
 50 *
 51 * Again, also this idea is pretty old and has been discussed on
 52 * kbuild-devel a long time ago. I don't have a sensibly working
 53 * internet connection right now, so I rather don't mention names
 54 * without double checking.
 55 *
 56 * This code here has been based partially based on mkdep.c, which
 57 * says the following about its history:
 58 *
 59 *   Copyright abandoned, Michael Chastain, <mailto:mec@shout.net>.
 60 *   This is a C version of syncdep.pl by Werner Almesberger.
 61 *
 62 *
 63 * It is invoked as
 64 *
 65 *   fixdep <depfile> <target> <cmdline>
 66 *
 67 * and will read the dependency file <depfile>
 68 *
 69 * The transformed dependency snipped is written to stdout.
 70 *
 71 * It first generates a line
 72 *
 73 *   cmd_<target> = <cmdline>
 74 *
 75 * and then basically copies the .<target>.d file to stdout, in the
 76 * process filtering out the dependency on autoconf.h and adding
 77 * dependencies on include/config/my/option.h for every
 78 * CONFIG_MY_OPTION encountered in any of the prerequisites.
 79 *
 80 * It will also filter out all the dependencies on *.ver. We need
 81 * to make sure that the generated version checksum are globally up
 82 * to date before even starting the recursive build, so it's too late
 83 * at this point anyway.
 84 *
 85 * We don't even try to really parse the header files, but
 
 86 * merely grep, i.e. if CONFIG_FOO is mentioned in a comment, it will
 87 * be picked up as well. It's not a problem with respect to
 88 * correctness, since that can only give too many dependencies, thus
 89 * we cannot miss a rebuild. Since people tend to not mention totally
 90 * unrelated CONFIG_ options all over the place, it's not an
 91 * efficiency problem either.
 92 *
 93 * (Note: it'd be easy to port over the complete mkdep state machine,
 94 *  but I don't think the added complexity is worth it)
 95 */
 
 
 
 
 
 
 
 
 96
 97#include <sys/types.h>
 98#include <sys/stat.h>
 
 99#include <unistd.h>
100#include <fcntl.h>
101#include <string.h>
102#include <stdarg.h>
103#include <stdlib.h>
104#include <stdio.h>
 
105#include <ctype.h>
 
 
 
 
 
 
 
 
 
 
106
107static void usage(void)
108{
109	fprintf(stderr, "Usage: fixdep <depfile> <target> <cmdline>\n");
110	exit(1);
111}
112
113/*
114 * In the intended usage of this program, the stdout is redirected to .*.cmd
115 * files. The return value of printf() and putchar() must be checked to catch
116 * any error, e.g. "No space left on device".
117 */
118static void xprintf(const char *format, ...)
119{
120	va_list ap;
121	int ret;
122
123	va_start(ap, format);
124	ret = vprintf(format, ap);
125	if (ret < 0) {
126		perror("fixdep");
127		exit(1);
128	}
129	va_end(ap);
130}
131
132static void xputchar(int c)
133{
134	int ret;
135
136	ret = putchar(c);
137	if (ret == EOF) {
138		perror("fixdep");
139		exit(1);
140	}
141}
142
143/*
144 * Print out a dependency path from a symbol name
145 */
146static void print_dep(const char *m, int slen, const char *dir)
147{
148	int c, prev_c = '/', i;
149
150	xprintf("    $(wildcard %s/", dir);
151	for (i = 0; i < slen; i++) {
152		c = m[i];
153		if (c == '_')
154			c = '/';
155		else
156			c = tolower(c);
157		if (c != '/' || prev_c != '/')
158			xputchar(c);
159		prev_c = c;
160	}
161	xprintf(".h) \\\n");
162}
163
164struct item {
165	struct item	*next;
166	unsigned int	len;
167	unsigned int	hash;
168	char		name[0];
169};
170
171#define HASHSZ 256
172static struct item *hashtab[HASHSZ];
173
174static unsigned int strhash(const char *str, unsigned int sz)
175{
176	/* fnv32 hash */
177	unsigned int i, hash = 2166136261U;
178
179	for (i = 0; i < sz; i++)
180		hash = (hash ^ str[i]) * 0x01000193;
181	return hash;
182}
183
184/*
185 * Lookup a value in the configuration string.
186 */
187static int is_defined_config(const char *name, int len, unsigned int hash)
188{
189	struct item *aux;
190
191	for (aux = hashtab[hash % HASHSZ]; aux; aux = aux->next) {
192		if (aux->hash == hash && aux->len == len &&
193		    memcmp(aux->name, name, len) == 0)
194			return 1;
195	}
196	return 0;
197}
198
199/*
200 * Add a new value to the configuration string.
201 */
202static void define_config(const char *name, int len, unsigned int hash)
203{
204	struct item *aux = malloc(sizeof(*aux) + len);
205
206	if (!aux) {
207		perror("fixdep:malloc");
208		exit(1);
209	}
210	memcpy(aux->name, name, len);
211	aux->len = len;
212	aux->hash = hash;
213	aux->next = hashtab[hash % HASHSZ];
214	hashtab[hash % HASHSZ] = aux;
215}
216
217/*
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
218 * Record the use of a CONFIG_* word.
219 */
220static void use_config(const char *m, int slen)
221{
222	unsigned int hash = strhash(m, slen);
 
223
224	if (is_defined_config(m, slen, hash))
225	    return;
226
227	define_config(m, slen, hash);
228	print_dep(m, slen, "include/config");
 
 
 
 
 
 
 
 
 
 
229}
230
231/* test if s ends in sub */
232static int str_ends_with(const char *s, int slen, const char *sub)
233{
234	int sublen = strlen(sub);
235
236	if (sublen > slen)
237		return 0;
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
238
239	return !memcmp(s + slen - sublen, sub, sublen);
 
 
 
 
 
 
240}
241
242static void parse_config_file(const char *p)
 
243{
244	const char *q, *r;
245	const char *start = p;
246
247	while ((p = strstr(p, "CONFIG_"))) {
248		if (p > start && (isalnum(p[-1]) || p[-1] == '_')) {
249			p += 7;
250			continue;
251		}
252		p += 7;
253		q = p;
254		while (*q && (isalnum(*q) || *q == '_'))
255			q++;
256		if (str_ends_with(p, q - p, "_MODULE"))
257			r = q - 7;
258		else
259			r = q;
260		if (r > p)
261			use_config(p, r - p);
262		p = q;
263	}
264}
265
266static void *read_file(const char *filename)
267{
268	struct stat st;
269	int fd;
270	char *buf;
271
272	fd = open(filename, O_RDONLY);
273	if (fd < 0) {
274		fprintf(stderr, "fixdep: error opening file: ");
275		perror(filename);
276		exit(2);
277	}
278	if (fstat(fd, &st) < 0) {
279		fprintf(stderr, "fixdep: error fstat'ing file: ");
280		perror(filename);
281		exit(2);
282	}
283	buf = malloc(st.st_size + 1);
284	if (!buf) {
285		perror("fixdep: malloc");
286		exit(2);
287	}
288	if (read(fd, buf, st.st_size) != st.st_size) {
289		perror("fixdep: read");
290		exit(2);
 
 
291	}
292	buf[st.st_size] = '\0';
293	close(fd);
294
295	return buf;
296}
297
298/* Ignore certain dependencies */
299static int is_ignored_file(const char *s, int len)
300{
301	return str_ends_with(s, len, "include/generated/autoconf.h") ||
302	       str_ends_with(s, len, "include/generated/autoksyms.h") ||
303	       str_ends_with(s, len, ".ver");
304}
305
306/*
307 * Important: The below generated source_foo.o and deps_foo.o variable
308 * assignments are parsed not only by make, but also by the rather simple
309 * parser in scripts/mod/sumversion.c.
310 */
311static void parse_dep_file(char *m, const char *target)
312{
 
 
313	char *p;
314	int is_last, is_target;
315	int saw_any_target = 0;
316	int is_first_dep = 0;
317	void *buf;
318
319	while (1) {
320		/* Skip any "white space" */
321		while (*m == ' ' || *m == '\\' || *m == '\n')
322			m++;
 
323
324		if (!*m)
325			break;
326
327		/* Find next "white space" */
 
 
 
328		p = m;
329		while (*p && *p != ' ' && *p != '\\' && *p != '\n')
 
 
330			p++;
331		is_last = (*p == '\0');
332		/* Is the token we found a target name? */
333		is_target = (*(p-1) == ':');
334		/* Don't write any target names into the dependency file */
335		if (is_target) {
336			/* The /next/ file is the first dependency */
337			is_first_dep = 1;
338		} else if (!is_ignored_file(m, p - m)) {
339			*p = '\0';
340
341			/*
342			 * Do not list the source file as dependency, so that
343			 * kbuild is not confused if a .c file is rewritten
344			 * into .S or vice versa. Storing it in source_* is
345			 * needed for modpost to compute srcversions.
346			 */
347			if (is_first_dep) {
348				/*
349				 * If processing the concatenation of multiple
350				 * dependency files, only process the first
351				 * target name, which will be the original
352				 * source name, and ignore any other target
353				 * names, which will be intermediate temporary
354				 * files.
355				 */
356				if (!saw_any_target) {
357					saw_any_target = 1;
358					xprintf("source_%s := %s\n\n",
359						target, m);
360					xprintf("deps_%s := \\\n", target);
361				}
362				is_first_dep = 0;
363			} else {
364				xprintf("  %s \\\n", m);
365			}
366
367			buf = read_file(m);
368			parse_config_file(buf);
369			free(buf);
370		}
371
372		if (is_last)
373			break;
374
375		/*
376		 * Start searching for next token immediately after the first
377		 * "whitespace" character that follows this token.
378		 */
379		m = p + 1;
380	}
 
 
 
381
382	if (!saw_any_target) {
383		fprintf(stderr, "fixdep: parse error; no targets found\n");
384		exit(1);
 
 
 
 
 
 
 
 
385	}
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
386
387	xprintf("\n%s: $(deps_%s)\n\n", target, target);
388	xprintf("$(deps_%s):\n", target);
 
 
 
389}
390
391int main(int argc, char *argv[])
392{
393	const char *depfile, *target, *cmdline;
394	void *buf;
395
396	if (argc != 4)
397		usage();
398
399	depfile = argv[1];
400	target = argv[2];
401	cmdline = argv[3];
402
403	xprintf("cmd_%s := %s\n\n", target, cmdline);
404
405	buf = read_file(depfile);
406	parse_dep_file(buf, target);
407	free(buf);
408
409	return 0;
410}
v3.5.6
  1/*
  2 * "Optimize" a list of dependencies as spit out by gcc -MD
  3 * for the kernel build
  4 * ===========================================================================
  5 *
  6 * Author       Kai Germaschewski
  7 * Copyright    2002 by Kai Germaschewski  <kai.germaschewski@gmx.de>
  8 *
  9 * This software may be used and distributed according to the terms
 10 * of the GNU General Public License, incorporated herein by reference.
 11 *
 12 *
 13 * Introduction:
 14 *
 15 * gcc produces a very nice and correct list of dependencies which
 16 * tells make when to remake a file.
 17 *
 18 * To use this list as-is however has the drawback that virtually
 19 * every file in the kernel includes autoconf.h.
 20 *
 21 * If the user re-runs make *config, autoconf.h will be
 22 * regenerated.  make notices that and will rebuild every file which
 23 * includes autoconf.h, i.e. basically all files. This is extremely
 24 * annoying if the user just changed CONFIG_HIS_DRIVER from n to m.
 25 *
 26 * So we play the same trick that "mkdep" played before. We replace
 27 * the dependency on autoconf.h by a dependency on every config
 28 * option which is mentioned in any of the listed prequisites.
 29 *
 30 * kconfig populates a tree in include/config/ with an empty file
 31 * for each config symbol and when the configuration is updated
 32 * the files representing changed config options are touched
 33 * which then let make pick up the changes and the files that use
 34 * the config symbols are rebuilt.
 35 *
 36 * So if the user changes his CONFIG_HIS_DRIVER option, only the objects
 37 * which depend on "include/linux/config/his/driver.h" will be rebuilt,
 38 * so most likely only his driver ;-)
 39 *
 40 * The idea above dates, by the way, back to Michael E Chastain, AFAIK.
 41 *
 42 * So to get dependencies right, there are two issues:
 43 * o if any of the files the compiler read changed, we need to rebuild
 44 * o if the command line given to the compile the file changed, we
 45 *   better rebuild as well.
 46 *
 47 * The former is handled by using the -MD output, the later by saving
 48 * the command line used to compile the old object and comparing it
 49 * to the one we would now use.
 50 *
 51 * Again, also this idea is pretty old and has been discussed on
 52 * kbuild-devel a long time ago. I don't have a sensibly working
 53 * internet connection right now, so I rather don't mention names
 54 * without double checking.
 55 *
 56 * This code here has been based partially based on mkdep.c, which
 57 * says the following about its history:
 58 *
 59 *   Copyright abandoned, Michael Chastain, <mailto:mec@shout.net>.
 60 *   This is a C version of syncdep.pl by Werner Almesberger.
 61 *
 62 *
 63 * It is invoked as
 64 *
 65 *   fixdep <depfile> <target> <cmdline>
 66 *
 67 * and will read the dependency file <depfile>
 68 *
 69 * The transformed dependency snipped is written to stdout.
 70 *
 71 * It first generates a line
 72 *
 73 *   cmd_<target> = <cmdline>
 74 *
 75 * and then basically copies the .<target>.d file to stdout, in the
 76 * process filtering out the dependency on autoconf.h and adding
 77 * dependencies on include/config/my/option.h for every
 78 * CONFIG_MY_OPTION encountered in any of the prequisites.
 79 *
 80 * It will also filter out all the dependencies on *.ver. We need
 81 * to make sure that the generated version checksum are globally up
 82 * to date before even starting the recursive build, so it's too late
 83 * at this point anyway.
 84 *
 85 * The algorithm to grep for "CONFIG_..." is bit unusual, but should
 86 * be fast ;-) We don't even try to really parse the header files, but
 87 * merely grep, i.e. if CONFIG_FOO is mentioned in a comment, it will
 88 * be picked up as well. It's not a problem with respect to
 89 * correctness, since that can only give too many dependencies, thus
 90 * we cannot miss a rebuild. Since people tend to not mention totally
 91 * unrelated CONFIG_ options all over the place, it's not an
 92 * efficiency problem either.
 93 *
 94 * (Note: it'd be easy to port over the complete mkdep state machine,
 95 *  but I don't think the added complexity is worth it)
 96 */
 97/*
 98 * Note 2: if somebody writes HELLO_CONFIG_BOOM in a file, it will depend onto
 99 * CONFIG_BOOM. This could seem a bug (not too hard to fix), but please do not
100 * fix it! Some UserModeLinux files (look at arch/um/) call CONFIG_BOOM as
101 * UML_CONFIG_BOOM, to avoid conflicts with /usr/include/linux/autoconf.h,
102 * through arch/um/include/uml-config.h; this fixdep "bug" makes sure that
103 * those files will have correct dependencies.
104 */
105
106#include <sys/types.h>
107#include <sys/stat.h>
108#include <sys/mman.h>
109#include <unistd.h>
110#include <fcntl.h>
111#include <string.h>
 
112#include <stdlib.h>
113#include <stdio.h>
114#include <limits.h>
115#include <ctype.h>
116#include <arpa/inet.h>
117
118#define INT_CONF ntohl(0x434f4e46)
119#define INT_ONFI ntohl(0x4f4e4649)
120#define INT_NFIG ntohl(0x4e464947)
121#define INT_FIG_ ntohl(0x4649475f)
122
123char *target;
124char *depfile;
125char *cmdline;
126
127static void usage(void)
128{
129	fprintf(stderr, "Usage: fixdep <depfile> <target> <cmdline>\n");
130	exit(1);
131}
132
133/*
134 * Print out the commandline prefixed with cmd_<target filename> :=
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
135 */
136static void print_cmdline(void)
137{
138	printf("cmd_%s := %s\n\n", target, cmdline);
 
 
 
 
 
 
 
 
 
 
 
 
 
139}
140
141struct item {
142	struct item	*next;
143	unsigned int	len;
144	unsigned int	hash;
145	char		name[0];
146};
147
148#define HASHSZ 256
149static struct item *hashtab[HASHSZ];
150
151static unsigned int strhash(const char *str, unsigned int sz)
152{
153	/* fnv32 hash */
154	unsigned int i, hash = 2166136261U;
155
156	for (i = 0; i < sz; i++)
157		hash = (hash ^ str[i]) * 0x01000193;
158	return hash;
159}
160
161/*
162 * Lookup a value in the configuration string.
163 */
164static int is_defined_config(const char *name, int len, unsigned int hash)
165{
166	struct item *aux;
167
168	for (aux = hashtab[hash % HASHSZ]; aux; aux = aux->next) {
169		if (aux->hash == hash && aux->len == len &&
170		    memcmp(aux->name, name, len) == 0)
171			return 1;
172	}
173	return 0;
174}
175
176/*
177 * Add a new value to the configuration string.
178 */
179static void define_config(const char *name, int len, unsigned int hash)
180{
181	struct item *aux = malloc(sizeof(*aux) + len);
182
183	if (!aux) {
184		perror("fixdep:malloc");
185		exit(1);
186	}
187	memcpy(aux->name, name, len);
188	aux->len = len;
189	aux->hash = hash;
190	aux->next = hashtab[hash % HASHSZ];
191	hashtab[hash % HASHSZ] = aux;
192}
193
194/*
195 * Clear the set of configuration strings.
196 */
197static void clear_config(void)
198{
199	struct item *aux, *next;
200	unsigned int i;
201
202	for (i = 0; i < HASHSZ; i++) {
203		for (aux = hashtab[i]; aux; aux = next) {
204			next = aux->next;
205			free(aux);
206		}
207		hashtab[i] = NULL;
208	}
209}
210
211/*
212 * Record the use of a CONFIG_* word.
213 */
214static void use_config(const char *m, int slen)
215{
216	unsigned int hash = strhash(m, slen);
217	int c, i;
218
219	if (is_defined_config(m, slen, hash))
220	    return;
221
222	define_config(m, slen, hash);
223
224	printf("    $(wildcard include/config/");
225	for (i = 0; i < slen; i++) {
226		c = m[i];
227		if (c == '_')
228			c = '/';
229		else
230			c = tolower(c);
231		putchar(c);
232	}
233	printf(".h) \\\n");
234}
235
236static void parse_config_file(const char *map, size_t len)
 
237{
238	const int *end = (const int *) (map + len);
239	/* start at +1, so that p can never be < map */
240	const int *m   = (const int *) map + 1;
241	const char *p, *q;
242
243	for (; m < end; m++) {
244		if (*m == INT_CONF) { p = (char *) m  ; goto conf; }
245		if (*m == INT_ONFI) { p = (char *) m-1; goto conf; }
246		if (*m == INT_NFIG) { p = (char *) m-2; goto conf; }
247		if (*m == INT_FIG_) { p = (char *) m-3; goto conf; }
248		continue;
249	conf:
250		if (p > map + len - 7)
251			continue;
252		if (memcmp(p, "CONFIG_", 7))
253			continue;
254		for (q = p + 7; q < map + len; q++) {
255			if (!(isalnum(*q) || *q == '_'))
256				goto found;
257		}
258		continue;
259
260	found:
261		if (!memcmp(q - 7, "_MODULE", 7))
262			q -= 7;
263		if( (q-p-7) < 0 )
264			continue;
265		use_config(p+7, q-p-7);
266	}
267}
268
269/* test is s ends in sub */
270static int strrcmp(char *s, char *sub)
271{
272	int slen = strlen(s);
273	int sublen = strlen(sub);
274
275	if (sublen > slen)
276		return 1;
277
278	return memcmp(s + slen - sublen, sub, sublen);
 
 
 
 
 
 
 
 
 
 
 
 
 
279}
280
281static void do_config_file(const char *filename)
282{
283	struct stat st;
284	int fd;
285	void *map;
286
287	fd = open(filename, O_RDONLY);
288	if (fd < 0) {
289		fprintf(stderr, "fixdep: error opening config file: ");
 
 
 
 
 
290		perror(filename);
291		exit(2);
292	}
293	fstat(fd, &st);
294	if (st.st_size == 0) {
295		close(fd);
296		return;
297	}
298	map = mmap(NULL, st.st_size, PROT_READ, MAP_PRIVATE, fd, 0);
299	if ((long) map == -1) {
300		perror("fixdep: mmap");
301		close(fd);
302		return;
303	}
 
 
304
305	parse_config_file(map, st.st_size);
 
306
307	munmap(map, st.st_size);
308
309	close(fd);
 
 
 
310}
311
312/*
313 * Important: The below generated source_foo.o and deps_foo.o variable
314 * assignments are parsed not only by make, but also by the rather simple
315 * parser in scripts/mod/sumversion.c.
316 */
317static void parse_dep_file(void *map, size_t len)
318{
319	char *m = map;
320	char *end = m + len;
321	char *p;
322	char s[PATH_MAX];
323	int first;
324
325	p = strchr(m, ':');
326	if (!p) {
327		fprintf(stderr, "fixdep: parse error\n");
328		exit(1);
329	}
330	memcpy(s, m, p-m); s[p-m] = 0;
331	m = p+1;
332
333	clear_config();
 
334
335	first = 1;
336	while (m < end) {
337		while (m < end && (*m == ' ' || *m == '\\' || *m == '\n'))
338			m++;
339		p = m;
340		while (p < end && *p != ' ') p++;
341		if (p == end) {
342			do p--; while (!isalnum(*p));
343			p++;
344		}
345		memcpy(s, m, p-m); s[p-m] = 0;
346		if (strrcmp(s, "include/generated/autoconf.h") &&
347		    strrcmp(s, "arch/um/include/uml-config.h") &&
348		    strrcmp(s, "include/linux/kconfig.h") &&
349		    strrcmp(s, ".ver")) {
 
 
 
 
350			/*
351			 * Do not list the source file as dependency, so that
352			 * kbuild is not confused if a .c file is rewritten
353			 * into .S or vice versa. Storing it in source_* is
354			 * needed for modpost to compute srcversions.
355			 */
356			if (first) {
357				printf("source_%s := %s\n\n", target, s);
358				printf("deps_%s := \\\n", target);
359			} else
360				printf("  %s \\\n", s);
361			do_config_file(s);
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
362		}
363		first = 0;
 
 
 
 
 
 
 
364		m = p + 1;
365	}
366	printf("\n%s: $(deps_%s)\n\n", target, target);
367	printf("$(deps_%s):\n", target);
368}
369
370static void print_deps(void)
371{
372	struct stat st;
373	int fd;
374	void *map;
375
376	fd = open(depfile, O_RDONLY);
377	if (fd < 0) {
378		fprintf(stderr, "fixdep: error opening depfile: ");
379		perror(depfile);
380		exit(2);
381	}
382	if (fstat(fd, &st) < 0) {
383                fprintf(stderr, "fixdep: error fstat'ing depfile: ");
384                perror(depfile);
385                exit(2);
386        }
387	if (st.st_size == 0) {
388		fprintf(stderr,"fixdep: %s is empty\n",depfile);
389		close(fd);
390		return;
391	}
392	map = mmap(NULL, st.st_size, PROT_READ, MAP_PRIVATE, fd, 0);
393	if ((long) map == -1) {
394		perror("fixdep: mmap");
395		close(fd);
396		return;
397	}
398
399	parse_dep_file(map, st.st_size);
400
401	munmap(map, st.st_size);
402
403	close(fd);
404}
405
406static void traps(void)
407{
408	static char test[] __attribute__((aligned(sizeof(int)))) = "CONF";
409	int *p = (int *)test;
410
411	if (*p != INT_CONF) {
412		fprintf(stderr, "fixdep: sizeof(int) != 4 or wrong endianess? %#x\n",
413			*p);
414		exit(2);
415	}
416}
417
418int main(int argc, char *argv[])
419{
420	traps();
 
421
422	if (argc != 4)
423		usage();
424
425	depfile = argv[1];
426	target = argv[2];
427	cmdline = argv[3];
428
429	print_cmdline();
430	print_deps();
 
 
 
431
432	return 0;
433}