Commit | Line | Data |
---|---|---|
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 | |
0e0345b7 | 37 | * which depend on "include/config/HIS_DRIVER" 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 | * | |
92215e7a | 73 | * savedcmd_<target> = <cmdline> |
1da177e4 LT |
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 |
0e0345b7 | 77 | * dependencies on include/config/MY_OPTION for every |
4e433fc4 | 78 | * CONFIG_MY_OPTION encountered in any of the prerequisites. |
1da177e4 | 79 | * |
dee81e98 | 80 | * We don't even try to really parse the header files, but |
1da177e4 LT |
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 | */ | |
1da177e4 LT |
91 | |
92 | #include <sys/types.h> | |
93 | #include <sys/stat.h> | |
1da177e4 LT |
94 | #include <unistd.h> |
95 | #include <fcntl.h> | |
96 | #include <string.h> | |
bc6df812 | 97 | #include <stdbool.h> |
1da177e4 LT |
98 | #include <stdlib.h> |
99 | #include <stdio.h> | |
1da177e4 | 100 | #include <ctype.h> |
1da177e4 | 101 | |
4356f489 | 102 | static void usage(void) |
1da177e4 | 103 | { |
bbda5ec6 | 104 | fprintf(stderr, "Usage: fixdep <depfile> <target> <cmdline>\n"); |
1da177e4 LT |
105 | exit(1); |
106 | } | |
107 | ||
8af27e1d ED |
108 | struct item { |
109 | struct item *next; | |
110 | unsigned int len; | |
111 | unsigned int hash; | |
859c8175 | 112 | char name[]; |
8af27e1d | 113 | }; |
1da177e4 | 114 | |
8af27e1d | 115 | #define HASHSZ 256 |
faa91c47 | 116 | static struct item *config_hashtab[HASHSZ], *file_hashtab[HASHSZ]; |
1da177e4 | 117 | |
8af27e1d ED |
118 | static unsigned int strhash(const char *str, unsigned int sz) |
119 | { | |
120 | /* fnv32 hash */ | |
121 | unsigned int i, hash = 2166136261U; | |
1da177e4 | 122 | |
8af27e1d ED |
123 | for (i = 0; i < sz; i++) |
124 | hash = (hash ^ str[i]) * 0x01000193; | |
125 | return hash; | |
126 | } | |
1da177e4 | 127 | |
1da177e4 LT |
128 | /* |
129 | * Add a new value to the configuration string. | |
130 | */ | |
871d6573 MY |
131 | static void add_to_hashtable(const char *name, int len, unsigned int hash, |
132 | struct item *hashtab[]) | |
1da177e4 | 133 | { |
8af27e1d | 134 | struct item *aux = malloc(sizeof(*aux) + len); |
1da177e4 | 135 | |
8af27e1d ED |
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; | |
1da177e4 LT |
145 | } |
146 | ||
871d6573 MY |
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 | */ | |
151 | static 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 | ||
1da177e4 LT |
167 | /* |
168 | * Record the use of a CONFIG_* word. | |
169 | */ | |
8af27e1d | 170 | static void use_config(const char *m, int slen) |
1da177e4 | 171 | { |
871d6573 MY |
172 | if (in_hashtable(m, slen, config_hashtab)) |
173 | return; | |
1da177e4 | 174 | |
0e0345b7 | 175 | /* Print out a dependency path from a symbol name. */ |
69304379 | 176 | printf(" $(wildcard include/config/%.*s) \\\n", slen, m); |
1da177e4 LT |
177 | } |
178 | ||
ab9ce9fe MY |
179 | /* test if s ends in sub */ |
180 | static 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 | ||
dee81e98 | 190 | static void parse_config_file(const char *p) |
1da177e4 | 191 | { |
dee81e98 | 192 | const char *q, *r; |
5b8ad96d | 193 | const char *start = p; |
dee81e98 AD |
194 | |
195 | while ((p = strstr(p, "CONFIG_"))) { | |
5b8ad96d RV |
196 | if (p > start && (isalnum(p[-1]) || p[-1] == '_')) { |
197 | p += 7; | |
198 | continue; | |
199 | } | |
d7211096 | 200 | p += 7; |
dee81e98 | 201 | q = p; |
3f9070a6 | 202 | while (isalnum(*q) || *q == '_') |
dee81e98 | 203 | q++; |
ab9ce9fe | 204 | if (str_ends_with(p, q - p, "_MODULE")) |
dee81e98 AD |
205 | r = q - 7; |
206 | else | |
207 | r = q; | |
208 | if (r > p) | |
209 | use_config(p, r - p); | |
210 | p = q; | |
1da177e4 LT |
211 | } |
212 | } | |
213 | ||
4003fd80 | 214 | static void *read_file(const char *filename) |
1da177e4 LT |
215 | { |
216 | struct stat st; | |
217 | int fd; | |
4003fd80 | 218 | char *buf; |
1da177e4 LT |
219 | |
220 | fd = open(filename, O_RDONLY); | |
221 | if (fd < 0) { | |
4003fd80 | 222 | fprintf(stderr, "fixdep: error opening file: "); |
1da177e4 LT |
223 | perror(filename); |
224 | exit(2); | |
225 | } | |
46fe94ad | 226 | if (fstat(fd, &st) < 0) { |
4003fd80 | 227 | fprintf(stderr, "fixdep: error fstat'ing file: "); |
46fe94ad TR |
228 | perror(filename); |
229 | exit(2); | |
230 | } | |
4003fd80 MY |
231 | buf = malloc(st.st_size + 1); |
232 | if (!buf) { | |
dee81e98 | 233 | perror("fixdep: malloc"); |
7c2ec43a | 234 | exit(2); |
1da177e4 | 235 | } |
4003fd80 | 236 | if (read(fd, buf, st.st_size) != st.st_size) { |
dee81e98 | 237 | perror("fixdep: read"); |
7c2ec43a | 238 | exit(2); |
dee81e98 | 239 | } |
4003fd80 | 240 | buf[st.st_size] = '\0'; |
dee81e98 | 241 | close(fd); |
1da177e4 | 242 | |
4003fd80 | 243 | return buf; |
1da177e4 LT |
244 | } |
245 | ||
87b95a81 MY |
246 | /* Ignore certain dependencies */ |
247 | static int is_ignored_file(const char *s, int len) | |
248 | { | |
249 | return str_ends_with(s, len, "include/generated/autoconf.h") || | |
87d660f0 | 250 | str_ends_with(s, len, "include/generated/autoksyms.h"); |
87b95a81 MY |
251 | } |
252 | ||
93c656de MY |
253 | /* Do not parse these files */ |
254 | static int is_no_parse_file(const char *s, int len) | |
255 | { | |
256 | /* rustc may list binary files in dep-info */ | |
257 | return str_ends_with(s, len, ".rlib") || | |
258 | str_ends_with(s, len, ".rmeta") || | |
259 | str_ends_with(s, len, ".so"); | |
260 | } | |
261 | ||
7840fea2 MM |
262 | /* |
263 | * Important: The below generated source_foo.o and deps_foo.o variable | |
264 | * assignments are parsed not only by make, but also by the rather simple | |
265 | * parser in scripts/mod/sumversion.c. | |
266 | */ | |
bc6df812 | 267 | static void parse_dep_file(char *p, const char *target) |
1da177e4 | 268 | { |
bc6df812 MY |
269 | bool saw_any_target = false; |
270 | bool is_target = true; | |
271 | bool is_source = false; | |
272 | bool need_parse; | |
273 | char *q, saved_c; | |
274 | ||
275 | while (*p) { | |
276 | /* handle some special characters first. */ | |
277 | switch (*p) { | |
278 | case '#': | |
279 | /* | |
280 | * skip comments. | |
281 | * rustc may emit comments to dep-info. | |
282 | */ | |
283 | p++; | |
284 | while (*p != '\0' && *p != '\n') { | |
285 | /* | |
286 | * escaped newlines continue the comment across | |
287 | * multiple lines. | |
288 | */ | |
289 | if (*p == '\\') | |
290 | p++; | |
291 | p++; | |
292 | } | |
293 | continue; | |
294 | case ' ': | |
295 | case '\t': | |
296 | /* skip whitespaces */ | |
297 | p++; | |
298 | continue; | |
299 | case '\\': | |
300 | /* | |
301 | * backslash/newline combinations continue the | |
302 | * statement. Skip it just like a whitespace. | |
303 | */ | |
304 | if (*(p + 1) == '\n') { | |
305 | p += 2; | |
306 | continue; | |
307 | } | |
01b5cbe7 | 308 | break; |
bc6df812 MY |
309 | case '\n': |
310 | /* | |
311 | * Makefiles use a line-based syntax, where the newline | |
312 | * is the end of a statement. After seeing a newline, | |
313 | * we expect the next token is a target. | |
314 | */ | |
1da177e4 | 315 | p++; |
bc6df812 MY |
316 | is_target = true; |
317 | continue; | |
318 | case ':': | |
87b95a81 | 319 | /* |
bc6df812 MY |
320 | * assume the first dependency after a colon as the |
321 | * source file. | |
87b95a81 | 322 | */ |
bc6df812 MY |
323 | p++; |
324 | is_target = false; | |
325 | is_source = true; | |
326 | continue; | |
327 | } | |
328 | ||
329 | /* find the end of the token */ | |
330 | q = p; | |
331 | while (*q != ' ' && *q != '\t' && *q != '\n' && *q != '#' && *q != ':') { | |
332 | if (*q == '\\') { | |
2ab8a996 | 333 | /* |
bc6df812 MY |
334 | * backslash/newline combinations work like as |
335 | * a whitespace, so this is the end of token. | |
2ab8a996 | 336 | */ |
bc6df812 MY |
337 | if (*(q + 1) == '\n') |
338 | break; | |
339 | ||
340 | /* escaped special characters */ | |
341 | if (*(q + 1) == '#' || *(q + 1) == ':') { | |
342 | memmove(p + 1, p, q - p); | |
343 | p++; | |
87b95a81 | 344 | } |
bc6df812 MY |
345 | |
346 | q++; | |
2ab8a996 | 347 | } |
87b95a81 | 348 | |
bc6df812 MY |
349 | if (*q == '\0') |
350 | break; | |
351 | q++; | |
1da177e4 | 352 | } |
01b5cbe7 | 353 | |
bc6df812 MY |
354 | /* Just discard the target */ |
355 | if (is_target) { | |
356 | p = q; | |
357 | continue; | |
358 | } | |
359 | ||
360 | saved_c = *q; | |
361 | *q = '\0'; | |
362 | need_parse = false; | |
01b5cbe7 | 363 | |
2ab8a996 | 364 | /* |
bc6df812 MY |
365 | * Do not list the source file as dependency, so that kbuild is |
366 | * not confused if a .c file is rewritten into .S or vice versa. | |
367 | * Storing it in source_* is needed for modpost to compute | |
368 | * srcversions. | |
2ab8a996 | 369 | */ |
bc6df812 MY |
370 | if (is_source) { |
371 | /* | |
372 | * The DT build rule concatenates multiple dep files. | |
373 | * When processing them, only process the first source | |
374 | * name, which will be the original one, and ignore any | |
375 | * other source names, which will be intermediate | |
376 | * temporary files. | |
faa91c47 MY |
377 | * |
378 | * rustc emits the same dependency list for each | |
379 | * emission type. It is enough to list the source name | |
380 | * just once. | |
bc6df812 MY |
381 | */ |
382 | if (!saw_any_target) { | |
383 | saw_any_target = true; | |
384 | printf("source_%s := %s\n\n", target, p); | |
385 | printf("deps_%s := \\\n", target); | |
386 | need_parse = true; | |
387 | } | |
faa91c47 MY |
388 | } else if (!is_ignored_file(p, q - p) && |
389 | !in_hashtable(p, q - p, file_hashtab)) { | |
bc6df812 MY |
390 | printf(" %s \\\n", p); |
391 | need_parse = true; | |
392 | } | |
393 | ||
93c656de | 394 | if (need_parse && !is_no_parse_file(p, q - p)) { |
bc6df812 MY |
395 | void *buf; |
396 | ||
397 | buf = read_file(p); | |
398 | parse_config_file(buf); | |
399 | free(buf); | |
400 | } | |
401 | ||
402 | is_source = false; | |
403 | *q = saved_c; | |
404 | p = q; | |
1da177e4 | 405 | } |
2ab8a996 SW |
406 | |
407 | if (!saw_any_target) { | |
408 | fprintf(stderr, "fixdep: parse error; no targets found\n"); | |
409 | exit(1); | |
410 | } | |
411 | ||
69304379 MY |
412 | printf("\n%s: $(deps_%s)\n\n", target, target); |
413 | printf("$(deps_%s):\n", target); | |
1da177e4 LT |
414 | } |
415 | ||
1da177e4 LT |
416 | int main(int argc, char *argv[]) |
417 | { | |
5d1ef76f | 418 | const char *depfile, *target, *cmdline; |
4003fd80 MY |
419 | void *buf; |
420 | ||
bbda5ec6 | 421 | if (argc != 4) |
1da177e4 LT |
422 | usage(); |
423 | ||
424 | depfile = argv[1]; | |
425 | target = argv[2]; | |
426 | cmdline = argv[3]; | |
427 | ||
92215e7a | 428 | printf("savedcmd_%s := %s\n\n", target, cmdline); |
4003fd80 MY |
429 | |
430 | buf = read_file(depfile); | |
bbda5ec6 | 431 | parse_dep_file(buf, target); |
4003fd80 | 432 | free(buf); |
1da177e4 | 433 | |
69304379 MY |
434 | fflush(stdout); |
435 | ||
436 | /* | |
437 | * In the intended usage, the stdout is redirected to .*.cmd files. | |
438 | * Call ferror() to catch errors such as "No space left on device". | |
439 | */ | |
440 | if (ferror(stdout)) { | |
441 | fprintf(stderr, "fixdep: not all data was written to the output\n"); | |
442 | exit(1); | |
443 | } | |
444 | ||
1da177e4 LT |
445 | return 0; |
446 | } |