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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" 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 * savedcmd_<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 for every
78 * CONFIG_MY_OPTION encountered in any of the prerequisites.
79 *
80 * We don't even try to really parse the header files, but
81 * merely grep, i.e. if CONFIG_FOO is mentioned in a comment, it will
82 * be picked up as well. It's not a problem with respect to
83 * correctness, since that can only give too many dependencies, thus
84 * we cannot miss a rebuild. Since people tend to not mention totally
85 * unrelated CONFIG_ options all over the place, it's not an
86 * efficiency problem either.
87 *
88 * (Note: it'd be easy to port over the complete mkdep state machine,
89 * but I don't think the added complexity is worth it)
90 */
91
92#include <sys/types.h>
93#include <sys/stat.h>
94#include <unistd.h>
95#include <fcntl.h>
96#include <string.h>
97#include <stdbool.h>
98#include <stdlib.h>
99#include <stdio.h>
100#include <ctype.h>
101
102static void usage(void)
103{
104 fprintf(stderr, "Usage: fixdep <depfile> <target> <cmdline>\n");
105 exit(1);
106}
107
108struct item {
109 struct item *next;
110 unsigned int len;
111 unsigned int hash;
112 char name[];
113};
114
115#define HASHSZ 256
116static struct item *config_hashtab[HASHSZ], *file_hashtab[HASHSZ];
117
118static unsigned int strhash(const char *str, unsigned int sz)
119{
120 /* fnv32 hash */
121 unsigned int i, hash = 2166136261U;
122
123 for (i = 0; i < sz; i++)
124 hash = (hash ^ str[i]) * 0x01000193;
125 return hash;
126}
127
128/*
129 * Add a new value to the configuration string.
130 */
131static void add_to_hashtable(const char *name, int len, unsigned int hash,
132 struct item *hashtab[])
133{
134 struct item *aux = malloc(sizeof(*aux) + len);
135
136 if (!aux) {
137 perror("fixdep:malloc");
138 exit(1);
139 }
140 memcpy(aux->name, name, len);
141 aux->len = len;
142 aux->hash = hash;
143 aux->next = hashtab[hash % HASHSZ];
144 hashtab[hash % HASHSZ] = aux;
145}
146
147/*
148 * Lookup a string in the hash table. If found, just return true.
149 * If not, add it to the hashtable and return false.
150 */
151static bool in_hashtable(const char *name, int len, struct item *hashtab[])
152{
153 struct item *aux;
154 unsigned int hash = strhash(name, len);
155
156 for (aux = hashtab[hash % HASHSZ]; aux; aux = aux->next) {
157 if (aux->hash == hash && aux->len == len &&
158 memcmp(aux->name, name, len) == 0)
159 return true;
160 }
161
162 add_to_hashtable(name, len, hash, hashtab);
163
164 return false;
165}
166
167/*
168 * Record the use of a CONFIG_* word.
169 */
170static void use_config(const char *m, int slen)
171{
172 if (in_hashtable(m, slen, config_hashtab))
173 return;
174
175 /* Print out a dependency path from a symbol name. */
176 printf(" $(wildcard include/config/%.*s) \\\n", slen, m);
177}
178
179/* test if s ends in sub */
180static int str_ends_with(const char *s, int slen, const char *sub)
181{
182 int sublen = strlen(sub);
183
184 if (sublen > slen)
185 return 0;
186
187 return !memcmp(s + slen - sublen, sub, sublen);
188}
189
190static void parse_config_file(const char *p)
191{
192 const char *q, *r;
193 const char *start = p;
194
195 while ((p = strstr(p, "CONFIG_"))) {
196 if (p > start && (isalnum(p[-1]) || p[-1] == '_')) {
197 p += 7;
198 continue;
199 }
200 p += 7;
201 q = p;
202 while (isalnum(*q) || *q == '_')
203 q++;
204 if (str_ends_with(p, q - p, "_MODULE"))
205 r = q - 7;
206 else
207 r = q;
208 if (r > p)
209 use_config(p, r - p);
210 p = q;
211 }
212}
213
214static void *read_file(const char *filename)
215{
216 struct stat st;
217 int fd;
218 char *buf;
219
220 fd = open(filename, O_RDONLY);
221 if (fd < 0) {
222 fprintf(stderr, "fixdep: error opening file: ");
223 perror(filename);
224 exit(2);
225 }
226 if (fstat(fd, &st) < 0) {
227 fprintf(stderr, "fixdep: error fstat'ing file: ");
228 perror(filename);
229 exit(2);
230 }
231 buf = malloc(st.st_size + 1);
232 if (!buf) {
233 perror("fixdep: malloc");
234 exit(2);
235 }
236 if (read(fd, buf, st.st_size) != st.st_size) {
237 perror("fixdep: read");
238 exit(2);
239 }
240 buf[st.st_size] = '\0';
241 close(fd);
242
243 return buf;
244}
245
246/* Ignore certain dependencies */
247static int is_ignored_file(const char *s, int len)
248{
249 return str_ends_with(s, len, "include/generated/autoconf.h");
250}
251
252/* Do not parse these files */
253static int is_no_parse_file(const char *s, int len)
254{
255 /* rustc may list binary files in dep-info */
256 return str_ends_with(s, len, ".rlib") ||
257 str_ends_with(s, len, ".rmeta") ||
258 str_ends_with(s, len, ".so");
259}
260
261/*
262 * Important: The below generated source_foo.o and deps_foo.o variable
263 * assignments are parsed not only by make, but also by the rather simple
264 * parser in scripts/mod/sumversion.c.
265 */
266static void parse_dep_file(char *p, const char *target)
267{
268 bool saw_any_target = false;
269 bool is_target = true;
270 bool is_source = false;
271 bool need_parse;
272 char *q, saved_c;
273
274 while (*p) {
275 /* handle some special characters first. */
276 switch (*p) {
277 case '#':
278 /*
279 * skip comments.
280 * rustc may emit comments to dep-info.
281 */
282 p++;
283 while (*p != '\0' && *p != '\n') {
284 /*
285 * escaped newlines continue the comment across
286 * multiple lines.
287 */
288 if (*p == '\\')
289 p++;
290 p++;
291 }
292 continue;
293 case ' ':
294 case '\t':
295 /* skip whitespaces */
296 p++;
297 continue;
298 case '\\':
299 /*
300 * backslash/newline combinations continue the
301 * statement. Skip it just like a whitespace.
302 */
303 if (*(p + 1) == '\n') {
304 p += 2;
305 continue;
306 }
307 break;
308 case '\n':
309 /*
310 * Makefiles use a line-based syntax, where the newline
311 * is the end of a statement. After seeing a newline,
312 * we expect the next token is a target.
313 */
314 p++;
315 is_target = true;
316 continue;
317 case ':':
318 /*
319 * assume the first dependency after a colon as the
320 * source file.
321 */
322 p++;
323 is_target = false;
324 is_source = true;
325 continue;
326 }
327
328 /* find the end of the token */
329 q = p;
330 while (*q != ' ' && *q != '\t' && *q != '\n' && *q != '#' && *q != ':') {
331 if (*q == '\\') {
332 /*
333 * backslash/newline combinations work like as
334 * a whitespace, so this is the end of token.
335 */
336 if (*(q + 1) == '\n')
337 break;
338
339 /* escaped special characters */
340 if (*(q + 1) == '#' || *(q + 1) == ':') {
341 memmove(p + 1, p, q - p);
342 p++;
343 }
344
345 q++;
346 }
347
348 if (*q == '\0')
349 break;
350 q++;
351 }
352
353 /* Just discard the target */
354 if (is_target) {
355 p = q;
356 continue;
357 }
358
359 saved_c = *q;
360 *q = '\0';
361 need_parse = false;
362
363 /*
364 * Do not list the source file as dependency, so that kbuild is
365 * not confused if a .c file is rewritten into .S or vice versa.
366 * Storing it in source_* is needed for modpost to compute
367 * srcversions.
368 */
369 if (is_source) {
370 /*
371 * The DT build rule concatenates multiple dep files.
372 * When processing them, only process the first source
373 * name, which will be the original one, and ignore any
374 * other source names, which will be intermediate
375 * temporary files.
376 *
377 * rustc emits the same dependency list for each
378 * emission type. It is enough to list the source name
379 * just once.
380 */
381 if (!saw_any_target) {
382 saw_any_target = true;
383 printf("source_%s := %s\n\n", target, p);
384 printf("deps_%s := \\\n", target);
385 need_parse = true;
386 }
387 } else if (!is_ignored_file(p, q - p) &&
388 !in_hashtable(p, q - p, file_hashtab)) {
389 printf(" %s \\\n", p);
390 need_parse = true;
391 }
392
393 if (need_parse && !is_no_parse_file(p, q - p)) {
394 void *buf;
395
396 buf = read_file(p);
397 parse_config_file(buf);
398 free(buf);
399 }
400
401 is_source = false;
402 *q = saved_c;
403 p = q;
404 }
405
406 if (!saw_any_target) {
407 fprintf(stderr, "fixdep: parse error; no targets found\n");
408 exit(1);
409 }
410
411 printf("\n%s: $(deps_%s)\n\n", target, target);
412 printf("$(deps_%s):\n", target);
413}
414
415int main(int argc, char *argv[])
416{
417 const char *depfile, *target, *cmdline;
418 void *buf;
419
420 if (argc != 4)
421 usage();
422
423 depfile = argv[1];
424 target = argv[2];
425 cmdline = argv[3];
426
427 printf("savedcmd_%s := %s\n\n", target, cmdline);
428
429 buf = read_file(depfile);
430 parse_dep_file(buf, target);
431 free(buf);
432
433 fflush(stdout);
434
435 /*
436 * In the intended usage, the stdout is redirected to .*.cmd files.
437 * Call ferror() to catch errors such as "No space left on device".
438 */
439 if (ferror(stdout)) {
440 fprintf(stderr, "fixdep: not all data was written to the output\n");
441 exit(1);
442 }
443
444 return 0;
445}
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 * 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 * Note 2: if somebody writes HELLO_CONFIG_BOOM in a file, it will depend onto
98 * CONFIG_BOOM. This could seem a bug (not too hard to fix), but please do not
99 * fix it! Some UserModeLinux files (look at arch/um/) call CONFIG_BOOM as
100 * UML_CONFIG_BOOM, to avoid conflicts with /usr/include/linux/autoconf.h,
101 * through arch/um/include/uml-config.h; this fixdep "bug" makes sure that
102 * those files will have correct dependencies.
103 */
104
105#include <sys/types.h>
106#include <sys/stat.h>
107#include <sys/mman.h>
108#include <unistd.h>
109#include <fcntl.h>
110#include <string.h>
111#include <stdlib.h>
112#include <stdio.h>
113#include <limits.h>
114#include <ctype.h>
115#include <arpa/inet.h>
116
117int insert_extra_deps;
118char *target;
119char *depfile;
120char *cmdline;
121
122static void usage(void)
123{
124 fprintf(stderr, "Usage: fixdep [-e] <depfile> <target> <cmdline>\n");
125 fprintf(stderr, " -e insert extra dependencies given on stdin\n");
126 exit(1);
127}
128
129/*
130 * Print out the commandline prefixed with cmd_<target filename> :=
131 */
132static void print_cmdline(void)
133{
134 printf("cmd_%s := %s\n\n", target, cmdline);
135}
136
137/*
138 * Print out a dependency path from a symbol name
139 */
140static void print_config(const char *m, int slen)
141{
142 int c, i;
143
144 printf(" $(wildcard include/config/");
145 for (i = 0; i < slen; i++) {
146 c = m[i];
147 if (c == '_')
148 c = '/';
149 else
150 c = tolower(c);
151 putchar(c);
152 }
153 printf(".h) \\\n");
154}
155
156static void do_extra_deps(void)
157{
158 if (insert_extra_deps) {
159 char buf[80];
160 while(fgets(buf, sizeof(buf), stdin)) {
161 int len = strlen(buf);
162 if (len < 2 || buf[len-1] != '\n') {
163 fprintf(stderr, "fixdep: bad data on stdin\n");
164 exit(1);
165 }
166 print_config(buf, len-1);
167 }
168 }
169}
170
171struct item {
172 struct item *next;
173 unsigned int len;
174 unsigned int hash;
175 char name[0];
176};
177
178#define HASHSZ 256
179static struct item *hashtab[HASHSZ];
180
181static unsigned int strhash(const char *str, unsigned int sz)
182{
183 /* fnv32 hash */
184 unsigned int i, hash = 2166136261U;
185
186 for (i = 0; i < sz; i++)
187 hash = (hash ^ str[i]) * 0x01000193;
188 return hash;
189}
190
191/*
192 * Lookup a value in the configuration string.
193 */
194static int is_defined_config(const char *name, int len, unsigned int hash)
195{
196 struct item *aux;
197
198 for (aux = hashtab[hash % HASHSZ]; aux; aux = aux->next) {
199 if (aux->hash == hash && aux->len == len &&
200 memcmp(aux->name, name, len) == 0)
201 return 1;
202 }
203 return 0;
204}
205
206/*
207 * Add a new value to the configuration string.
208 */
209static void define_config(const char *name, int len, unsigned int hash)
210{
211 struct item *aux = malloc(sizeof(*aux) + len);
212
213 if (!aux) {
214 perror("fixdep:malloc");
215 exit(1);
216 }
217 memcpy(aux->name, name, len);
218 aux->len = len;
219 aux->hash = hash;
220 aux->next = hashtab[hash % HASHSZ];
221 hashtab[hash % HASHSZ] = aux;
222}
223
224/*
225 * Record the use of a CONFIG_* word.
226 */
227static void use_config(const char *m, int slen)
228{
229 unsigned int hash = strhash(m, slen);
230
231 if (is_defined_config(m, slen, hash))
232 return;
233
234 define_config(m, slen, hash);
235 print_config(m, slen);
236}
237
238static void parse_config_file(const char *p)
239{
240 const char *q, *r;
241
242 while ((p = strstr(p, "CONFIG_"))) {
243 p += 7;
244 q = p;
245 while (*q && (isalnum(*q) || *q == '_'))
246 q++;
247 if (memcmp(q - 7, "_MODULE", 7) == 0)
248 r = q - 7;
249 else
250 r = q;
251 if (r > p)
252 use_config(p, r - p);
253 p = q;
254 }
255}
256
257/* test if s ends in sub */
258static int strrcmp(const char *s, const char *sub)
259{
260 int slen = strlen(s);
261 int sublen = strlen(sub);
262
263 if (sublen > slen)
264 return 1;
265
266 return memcmp(s + slen - sublen, sub, sublen);
267}
268
269static void do_config_file(const char *filename)
270{
271 struct stat st;
272 int fd;
273 char *map;
274
275 fd = open(filename, O_RDONLY);
276 if (fd < 0) {
277 fprintf(stderr, "fixdep: error opening config file: ");
278 perror(filename);
279 exit(2);
280 }
281 if (fstat(fd, &st) < 0) {
282 fprintf(stderr, "fixdep: error fstat'ing config file: ");
283 perror(filename);
284 exit(2);
285 }
286 if (st.st_size == 0) {
287 close(fd);
288 return;
289 }
290 map = malloc(st.st_size + 1);
291 if (!map) {
292 perror("fixdep: malloc");
293 close(fd);
294 return;
295 }
296 if (read(fd, map, st.st_size) != st.st_size) {
297 perror("fixdep: read");
298 close(fd);
299 return;
300 }
301 map[st.st_size] = '\0';
302 close(fd);
303
304 parse_config_file(map);
305
306 free(map);
307}
308
309/*
310 * Important: The below generated source_foo.o and deps_foo.o variable
311 * assignments are parsed not only by make, but also by the rather simple
312 * parser in scripts/mod/sumversion.c.
313 */
314static void parse_dep_file(void *map, size_t len)
315{
316 char *m = map;
317 char *end = m + len;
318 char *p;
319 char s[PATH_MAX];
320 int is_target;
321 int saw_any_target = 0;
322 int is_first_dep = 0;
323
324 while (m < end) {
325 /* Skip any "white space" */
326 while (m < end && (*m == ' ' || *m == '\\' || *m == '\n'))
327 m++;
328 /* Find next "white space" */
329 p = m;
330 while (p < end && *p != ' ' && *p != '\\' && *p != '\n')
331 p++;
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 {
339 /* Save this token/filename */
340 memcpy(s, m, p-m);
341 s[p - m] = 0;
342
343 /* Ignore certain dependencies */
344 if (strrcmp(s, "include/generated/autoconf.h") &&
345 strrcmp(s, "include/generated/autoksyms.h") &&
346 strrcmp(s, "arch/um/include/uml-config.h") &&
347 strrcmp(s, "include/linux/kconfig.h") &&
348 strrcmp(s, ".ver")) {
349 /*
350 * Do not list the source file as dependency,
351 * so that kbuild is not confused if a .c file
352 * is rewritten into .S or vice versa. Storing
353 * it in source_* is needed for modpost to
354 * compute srcversions.
355 */
356 if (is_first_dep) {
357 /*
358 * If processing the concatenation of
359 * multiple dependency files, only
360 * process the first target name, which
361 * will be the original source name,
362 * and ignore any other target names,
363 * which will be intermediate temporary
364 * files.
365 */
366 if (!saw_any_target) {
367 saw_any_target = 1;
368 printf("source_%s := %s\n\n",
369 target, s);
370 printf("deps_%s := \\\n",
371 target);
372 }
373 is_first_dep = 0;
374 } else
375 printf(" %s \\\n", s);
376 do_config_file(s);
377 }
378 }
379 /*
380 * Start searching for next token immediately after the first
381 * "whitespace" character that follows this token.
382 */
383 m = p + 1;
384 }
385
386 if (!saw_any_target) {
387 fprintf(stderr, "fixdep: parse error; no targets found\n");
388 exit(1);
389 }
390
391 do_extra_deps();
392
393 printf("\n%s: $(deps_%s)\n\n", target, target);
394 printf("$(deps_%s):\n", target);
395}
396
397static void print_deps(void)
398{
399 struct stat st;
400 int fd;
401 void *map;
402
403 fd = open(depfile, O_RDONLY);
404 if (fd < 0) {
405 fprintf(stderr, "fixdep: error opening depfile: ");
406 perror(depfile);
407 exit(2);
408 }
409 if (fstat(fd, &st) < 0) {
410 fprintf(stderr, "fixdep: error fstat'ing depfile: ");
411 perror(depfile);
412 exit(2);
413 }
414 if (st.st_size == 0) {
415 fprintf(stderr,"fixdep: %s is empty\n",depfile);
416 close(fd);
417 return;
418 }
419 map = mmap(NULL, st.st_size, PROT_READ, MAP_PRIVATE, fd, 0);
420 if ((long) map == -1) {
421 perror("fixdep: mmap");
422 close(fd);
423 return;
424 }
425
426 parse_dep_file(map, st.st_size);
427
428 munmap(map, st.st_size);
429
430 close(fd);
431}
432
433int main(int argc, char *argv[])
434{
435 if (argc == 5 && !strcmp(argv[1], "-e")) {
436 insert_extra_deps = 1;
437 argv++;
438 } else if (argc != 4)
439 usage();
440
441 depfile = argv[1];
442 target = argv[2];
443 cmdline = argv[3];
444
445 print_cmdline();
446 print_deps();
447
448 return 0;
449}