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Commit | Line | Data |
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1da177e4 LT |
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 | |
264a2683 | 19 | * every file in the kernel includes autoconf.h. |
1da177e4 | 20 | * |
264a2683 | 21 | * If the user re-runs make *config, autoconf.h will be |
1da177e4 LT |
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 | |
264a2683 | 27 | * the dependency on autoconf.h by a dependency on every config |
4e433fc4 | 28 | * option which is mentioned in any of the listed prerequisites. |
1da177e4 | 29 | * |
c21b1e4d JB |
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. | |
1da177e4 LT |
35 | * |
36 | * So if the user changes his CONFIG_HIS_DRIVER option, only the objects | |
4e433fc4 | 37 | * which depend on "include/config/his/driver.h" will be rebuilt, |
1da177e4 LT |
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 | |
264a2683 | 76 | * process filtering out the dependency on autoconf.h and adding |
1da177e4 | 77 | * dependencies on include/config/my/option.h for every |
4e433fc4 | 78 | * CONFIG_MY_OPTION encountered in any of the prerequisites. |
1da177e4 LT |
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 | * | |
dee81e98 | 85 | * We don't even try to really parse the header files, but |
1da177e4 LT |
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 | ||
d8329e35 | 117 | int insert_extra_deps; |
1da177e4 LT |
118 | char *target; |
119 | char *depfile; | |
120 | char *cmdline; | |
121 | ||
4356f489 | 122 | static void usage(void) |
1da177e4 | 123 | { |
d8329e35 NP |
124 | fprintf(stderr, "Usage: fixdep [-e] <depfile> <target> <cmdline>\n"); |
125 | fprintf(stderr, " -e insert extra dependencies given on stdin\n"); | |
1da177e4 LT |
126 | exit(1); |
127 | } | |
128 | ||
4d99f93b SR |
129 | /* |
130 | * Print out the commandline prefixed with cmd_<target filename> := | |
6176aa9a | 131 | */ |
4356f489 | 132 | static void print_cmdline(void) |
1da177e4 | 133 | { |
6176aa9a | 134 | printf("cmd_%s := %s\n\n", target, cmdline); |
1da177e4 LT |
135 | } |
136 | ||
d8329e35 NP |
137 | /* |
138 | * Print out a dependency path from a symbol name | |
139 | */ | |
140 | static 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 | ||
156 | static 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 | ||
8af27e1d ED |
171 | struct item { |
172 | struct item *next; | |
173 | unsigned int len; | |
174 | unsigned int hash; | |
175 | char name[0]; | |
176 | }; | |
1da177e4 | 177 | |
8af27e1d ED |
178 | #define HASHSZ 256 |
179 | static struct item *hashtab[HASHSZ]; | |
1da177e4 | 180 | |
8af27e1d ED |
181 | static unsigned int strhash(const char *str, unsigned int sz) |
182 | { | |
183 | /* fnv32 hash */ | |
184 | unsigned int i, hash = 2166136261U; | |
1da177e4 | 185 | |
8af27e1d ED |
186 | for (i = 0; i < sz; i++) |
187 | hash = (hash ^ str[i]) * 0x01000193; | |
188 | return hash; | |
189 | } | |
1da177e4 LT |
190 | |
191 | /* | |
192 | * Lookup a value in the configuration string. | |
193 | */ | |
8af27e1d | 194 | static int is_defined_config(const char *name, int len, unsigned int hash) |
1da177e4 | 195 | { |
8af27e1d ED |
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) | |
1da177e4 LT |
201 | return 1; |
202 | } | |
203 | return 0; | |
204 | } | |
205 | ||
206 | /* | |
207 | * Add a new value to the configuration string. | |
208 | */ | |
8af27e1d | 209 | static void define_config(const char *name, int len, unsigned int hash) |
1da177e4 | 210 | { |
8af27e1d | 211 | struct item *aux = malloc(sizeof(*aux) + len); |
1da177e4 | 212 | |
8af27e1d ED |
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; | |
1da177e4 LT |
222 | } |
223 | ||
1da177e4 LT |
224 | /* |
225 | * Record the use of a CONFIG_* word. | |
226 | */ | |
8af27e1d | 227 | static void use_config(const char *m, int slen) |
1da177e4 | 228 | { |
8af27e1d | 229 | unsigned int hash = strhash(m, slen); |
1da177e4 | 230 | |
8af27e1d | 231 | if (is_defined_config(m, slen, hash)) |
1da177e4 LT |
232 | return; |
233 | ||
8af27e1d | 234 | define_config(m, slen, hash); |
d8329e35 | 235 | print_config(m, slen); |
1da177e4 LT |
236 | } |
237 | ||
dee81e98 | 238 | static void parse_config_file(const char *p) |
1da177e4 | 239 | { |
dee81e98 AD |
240 | const char *q, *r; |
241 | ||
242 | while ((p = strstr(p, "CONFIG_"))) { | |
d7211096 | 243 | p += 7; |
dee81e98 AD |
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; | |
1da177e4 LT |
254 | } |
255 | } | |
256 | ||
d8329e35 | 257 | /* test if s ends in sub */ |
4c835b57 | 258 | static int strrcmp(const char *s, const char *sub) |
1da177e4 LT |
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 | ||
8af27e1d | 269 | static void do_config_file(const char *filename) |
1da177e4 LT |
270 | { |
271 | struct stat st; | |
272 | int fd; | |
dee81e98 | 273 | char *map; |
1da177e4 LT |
274 | |
275 | fd = open(filename, O_RDONLY); | |
276 | if (fd < 0) { | |
a3ba8113 | 277 | fprintf(stderr, "fixdep: error opening config file: "); |
1da177e4 LT |
278 | perror(filename); |
279 | exit(2); | |
280 | } | |
46fe94ad TR |
281 | if (fstat(fd, &st) < 0) { |
282 | fprintf(stderr, "fixdep: error fstat'ing config file: "); | |
283 | perror(filename); | |
284 | exit(2); | |
285 | } | |
1da177e4 LT |
286 | if (st.st_size == 0) { |
287 | close(fd); | |
288 | return; | |
289 | } | |
dee81e98 AD |
290 | map = malloc(st.st_size + 1); |
291 | if (!map) { | |
292 | perror("fixdep: malloc"); | |
7c2ec43a | 293 | exit(2); |
1da177e4 | 294 | } |
dee81e98 AD |
295 | if (read(fd, map, st.st_size) != st.st_size) { |
296 | perror("fixdep: read"); | |
7c2ec43a | 297 | exit(2); |
dee81e98 AD |
298 | } |
299 | map[st.st_size] = '\0'; | |
300 | close(fd); | |
1da177e4 | 301 | |
dee81e98 | 302 | parse_config_file(map); |
1da177e4 | 303 | |
dee81e98 | 304 | free(map); |
1da177e4 LT |
305 | } |
306 | ||
7840fea2 MM |
307 | /* |
308 | * Important: The below generated source_foo.o and deps_foo.o variable | |
309 | * assignments are parsed not only by make, but also by the rather simple | |
310 | * parser in scripts/mod/sumversion.c. | |
311 | */ | |
4356f489 | 312 | static void parse_dep_file(void *map, size_t len) |
1da177e4 | 313 | { |
48b9d03c M |
314 | char *m = map; |
315 | char *end = m + len; | |
316 | char *p; | |
1da177e4 | 317 | char s[PATH_MAX]; |
2ab8a996 SW |
318 | int is_target; |
319 | int saw_any_target = 0; | |
320 | int is_first_dep = 0; | |
1da177e4 | 321 | |
1da177e4 | 322 | while (m < end) { |
2ab8a996 | 323 | /* Skip any "white space" */ |
1da177e4 LT |
324 | while (m < end && (*m == ' ' || *m == '\\' || *m == '\n')) |
325 | m++; | |
2ab8a996 | 326 | /* Find next "white space" */ |
1da177e4 | 327 | p = m; |
2ab8a996 | 328 | while (p < end && *p != ' ' && *p != '\\' && *p != '\n') |
1da177e4 | 329 | p++; |
2ab8a996 SW |
330 | /* Is the token we found a target name? */ |
331 | is_target = (*(p-1) == ':'); | |
332 | /* Don't write any target names into the dependency file */ | |
333 | if (is_target) { | |
334 | /* The /next/ file is the first dependency */ | |
335 | is_first_dep = 1; | |
336 | } else { | |
337 | /* Save this token/filename */ | |
338 | memcpy(s, m, p-m); | |
339 | s[p - m] = 0; | |
340 | ||
341 | /* Ignore certain dependencies */ | |
342 | if (strrcmp(s, "include/generated/autoconf.h") && | |
c1a95fda | 343 | strrcmp(s, "include/generated/autoksyms.h") && |
2ab8a996 SW |
344 | strrcmp(s, "arch/um/include/uml-config.h") && |
345 | strrcmp(s, "include/linux/kconfig.h") && | |
346 | strrcmp(s, ".ver")) { | |
347 | /* | |
348 | * Do not list the source file as dependency, | |
349 | * so that kbuild is not confused if a .c file | |
350 | * is rewritten into .S or vice versa. Storing | |
351 | * it in source_* is needed for modpost to | |
352 | * compute srcversions. | |
353 | */ | |
354 | if (is_first_dep) { | |
355 | /* | |
356 | * If processing the concatenation of | |
357 | * multiple dependency files, only | |
358 | * process the first target name, which | |
359 | * will be the original source name, | |
360 | * and ignore any other target names, | |
361 | * which will be intermediate temporary | |
362 | * files. | |
363 | */ | |
364 | if (!saw_any_target) { | |
365 | saw_any_target = 1; | |
366 | printf("source_%s := %s\n\n", | |
367 | target, s); | |
368 | printf("deps_%s := \\\n", | |
369 | target); | |
370 | } | |
371 | is_first_dep = 0; | |
372 | } else | |
373 | printf(" %s \\\n", s); | |
374 | do_config_file(s); | |
375 | } | |
1da177e4 | 376 | } |
2ab8a996 SW |
377 | /* |
378 | * Start searching for next token immediately after the first | |
379 | * "whitespace" character that follows this token. | |
380 | */ | |
1da177e4 LT |
381 | m = p + 1; |
382 | } | |
2ab8a996 SW |
383 | |
384 | if (!saw_any_target) { | |
385 | fprintf(stderr, "fixdep: parse error; no targets found\n"); | |
386 | exit(1); | |
387 | } | |
388 | ||
d8329e35 NP |
389 | do_extra_deps(); |
390 | ||
1da177e4 LT |
391 | printf("\n%s: $(deps_%s)\n\n", target, target); |
392 | printf("$(deps_%s):\n", target); | |
393 | } | |
394 | ||
4356f489 | 395 | static void print_deps(void) |
1da177e4 LT |
396 | { |
397 | struct stat st; | |
398 | int fd; | |
399 | void *map; | |
400 | ||
401 | fd = open(depfile, O_RDONLY); | |
402 | if (fd < 0) { | |
a3ba8113 | 403 | fprintf(stderr, "fixdep: error opening depfile: "); |
1da177e4 LT |
404 | perror(depfile); |
405 | exit(2); | |
406 | } | |
a3ba8113 | 407 | if (fstat(fd, &st) < 0) { |
bb66fc67 MY |
408 | fprintf(stderr, "fixdep: error fstat'ing depfile: "); |
409 | perror(depfile); | |
410 | exit(2); | |
411 | } | |
1da177e4 LT |
412 | if (st.st_size == 0) { |
413 | fprintf(stderr,"fixdep: %s is empty\n",depfile); | |
414 | close(fd); | |
415 | return; | |
416 | } | |
417 | map = mmap(NULL, st.st_size, PROT_READ, MAP_PRIVATE, fd, 0); | |
418 | if ((long) map == -1) { | |
419 | perror("fixdep: mmap"); | |
420 | close(fd); | |
421 | return; | |
422 | } | |
423 | ||
424 | parse_dep_file(map, st.st_size); | |
425 | ||
426 | munmap(map, st.st_size); | |
427 | ||
428 | close(fd); | |
429 | } | |
430 | ||
1da177e4 LT |
431 | int main(int argc, char *argv[]) |
432 | { | |
d8329e35 NP |
433 | if (argc == 5 && !strcmp(argv[1], "-e")) { |
434 | insert_extra_deps = 1; | |
435 | argv++; | |
436 | } else if (argc != 4) | |
1da177e4 LT |
437 | usage(); |
438 | ||
439 | depfile = argv[1]; | |
440 | target = argv[2]; | |
441 | cmdline = argv[3]; | |
442 | ||
443 | print_cmdline(); | |
444 | print_deps(); | |
445 | ||
446 | return 0; | |
447 | } |