Contents of /trunk/mkinitrd-magellan/busybox/scripts/basic/fixdep.c
Parent Directory | Revision Log
Revision 984 -
(show annotations)
(download)
Sun May 30 11:32:42 2010 UTC (13 years, 11 months ago) by niro
File MIME type: text/plain
File size: 9878 byte(s)
Sun May 30 11:32:42 2010 UTC (13 years, 11 months ago) by niro
File MIME type: text/plain
File size: 9878 byte(s)
-updated to busybox-1.16.1 and enabled blkid/uuid support in default config
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 <linux/config.h> which then again |
20 | * includes <linux/autoconf.h> |
21 | * |
22 | * If the user re-runs make *config, linux/autoconf.h will be |
23 | * regenerated. make notices that and will rebuild every file which |
24 | * includes autoconf.h, i.e. basically all files. This is extremely |
25 | * annoying if the user just changed CONFIG_HIS_DRIVER from n to m. |
26 | * |
27 | * So we play the same trick that "mkdep" played before. We replace |
28 | * the dependency on linux/autoconf.h by a dependency on every config |
29 | * option which is mentioned in any of the listed prequisites. |
30 | * |
31 | * To be exact, split-include populates a tree in include/config/, |
32 | * e.g. include/config/his/driver.h, which contains the #define/#undef |
33 | * for the CONFIG_HIS_DRIVER option. |
34 | * |
35 | * So if the user changes his CONFIG_HIS_DRIVER option, only the objects |
36 | * which depend on "include/linux/config/his/driver.h" will be rebuilt, |
37 | * so most likely only his driver ;-) |
38 | * |
39 | * The idea above dates, by the way, back to Michael E Chastain, AFAIK. |
40 | * |
41 | * So to get dependencies right, there are two issues: |
42 | * o if any of the files the compiler read changed, we need to rebuild |
43 | * o if the command line given to the compile the file changed, we |
44 | * better rebuild as well. |
45 | * |
46 | * The former is handled by using the -MD output, the later by saving |
47 | * the command line used to compile the old object and comparing it |
48 | * to the one we would now use. |
49 | * |
50 | * Again, also this idea is pretty old and has been discussed on |
51 | * kbuild-devel a long time ago. I don't have a sensibly working |
52 | * internet connection right now, so I rather don't mention names |
53 | * without double checking. |
54 | * |
55 | * This code here has been based partially based on mkdep.c, which |
56 | * says the following about its history: |
57 | * |
58 | * Copyright abandoned, Michael Chastain, <mailto:mec@shout.net>. |
59 | * This is a C version of syncdep.pl by Werner Almesberger. |
60 | * |
61 | * |
62 | * It is invoked as |
63 | * |
64 | * fixdep <depfile> <target> <cmdline> |
65 | * |
66 | * and will read the dependency file <depfile> |
67 | * |
68 | * The transformed dependency snipped is written to stdout. |
69 | * |
70 | * It first generates a line |
71 | * |
72 | * cmd_<target> = <cmdline> |
73 | * |
74 | * and then basically copies the .<target>.d file to stdout, in the |
75 | * process filtering out the dependency on linux/autoconf.h and adding |
76 | * dependencies on include/config/my/option.h for every |
77 | * CONFIG_MY_OPTION encountered in any of the prequisites. |
78 | * |
79 | * It will also filter out all the dependencies on *.ver. We need |
80 | * to make sure that the generated version checksum are globally up |
81 | * to date before even starting the recursive build, so it's too late |
82 | * at this point anyway. |
83 | * |
84 | * The algorithm to grep for "CONFIG_..." is bit unusual, but should |
85 | * be fast ;-) 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 | |
117 | /* bbox: not needed |
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 | */ |
123 | |
124 | char *target; |
125 | char *depfile; |
126 | char *cmdline; |
127 | |
128 | void usage(void) |
129 | |
130 | { |
131 | fprintf(stderr, "Usage: fixdep <depfile> <target> <cmdline>\n"); |
132 | exit(1); |
133 | } |
134 | |
135 | /* |
136 | * Print out the commandline prefixed with cmd_<target filename> := |
137 | */ |
138 | void print_cmdline(void) |
139 | { |
140 | printf("cmd_%s := %s\n\n", target, cmdline); |
141 | } |
142 | |
143 | char * str_config = NULL; |
144 | int size_config = 0; |
145 | int len_config = 0; |
146 | |
147 | /* |
148 | * Grow the configuration string to a desired length. |
149 | * Usually the first growth is plenty. |
150 | */ |
151 | void grow_config(int len) |
152 | { |
153 | while (len_config + len > size_config) { |
154 | if (size_config == 0) |
155 | size_config = 2048; |
156 | str_config = realloc(str_config, size_config *= 2); |
157 | if (str_config == NULL) |
158 | { perror("fixdep:malloc"); exit(1); } |
159 | } |
160 | } |
161 | |
162 | |
163 | |
164 | /* |
165 | * Lookup a value in the configuration string. |
166 | */ |
167 | int is_defined_config(const char * name, int len) |
168 | { |
169 | const char * pconfig; |
170 | const char * plast = str_config + len_config - len; |
171 | for ( pconfig = str_config + 1; pconfig < plast; pconfig++ ) { |
172 | if (pconfig[ -1] == '\n' |
173 | && pconfig[len] == '\n' |
174 | && !memcmp(pconfig, name, len)) |
175 | return 1; |
176 | } |
177 | return 0; |
178 | } |
179 | |
180 | /* |
181 | * Add a new value to the configuration string. |
182 | */ |
183 | void define_config(const char * name, int len) |
184 | { |
185 | grow_config(len + 1); |
186 | |
187 | memcpy(str_config+len_config, name, len); |
188 | len_config += len; |
189 | str_config[len_config++] = '\n'; |
190 | } |
191 | |
192 | /* |
193 | * Clear the set of configuration strings. |
194 | */ |
195 | void clear_config(void) |
196 | { |
197 | len_config = 0; |
198 | define_config("", 0); |
199 | } |
200 | |
201 | /* |
202 | * Record the use of a CONFIG_* word. |
203 | */ |
204 | void use_config(char *m, int slen) |
205 | { |
206 | char s[PATH_MAX]; |
207 | char *p; |
208 | |
209 | if (is_defined_config(m, slen)) |
210 | return; |
211 | |
212 | define_config(m, slen); |
213 | |
214 | memcpy(s, m, slen); s[slen] = 0; |
215 | |
216 | for (p = s; p < s + slen; p++) { |
217 | if (*p == '_') |
218 | *p = '/'; |
219 | else |
220 | *p = tolower((int)*p); |
221 | } |
222 | printf(" $(wildcard include/config/%s.h) \\\n", s); |
223 | } |
224 | |
225 | void parse_config_file(char *map, size_t len) |
226 | { |
227 | /* modified for bbox */ |
228 | char *end_3 = map + len - 3; /* 3 == length of "IF_" */ |
229 | char *end_7 = map + len - 7; |
230 | char *p = map; |
231 | char *q; |
232 | int off; |
233 | |
234 | for (; p <= end_3; p++) { |
235 | /* Find next identifier's beginning */ |
236 | if (!(isalnum(*p) || *p == '_')) |
237 | continue; |
238 | |
239 | /* Check it */ |
240 | if (p < end_7 && p[6] == '_') { |
241 | if (!memcmp(p, "CONFIG", 6)) goto conf7; |
242 | if (!memcmp(p, "ENABLE", 6)) goto conf7; |
243 | if (!memcmp(p, "IF_NOT", 6)) goto conf7; |
244 | } |
245 | /* we have at least 3 chars because of p <= end_3 */ |
246 | /*if (!memcmp(p, "IF_", 3)) goto conf3;*/ |
247 | if (p[0] == 'I' && p[1] == 'F' && p[2] == '_') goto conf3; |
248 | |
249 | /* This identifier is not interesting, skip it */ |
250 | while (p <= end_3 && (isalnum(*p) || *p == '_')) |
251 | p++; |
252 | continue; |
253 | |
254 | conf3: off = 3; |
255 | conf7: off = 7; |
256 | p += off; |
257 | for (q = p; q < end_3+3; q++) { |
258 | if (!(isalnum(*q) || *q == '_')) |
259 | break; |
260 | } |
261 | use_config(p, q-p); |
262 | } |
263 | } |
264 | |
265 | /* test is s ends in sub */ |
266 | int strrcmp(char *s, char *sub) |
267 | { |
268 | int slen = strlen(s); |
269 | int sublen = strlen(sub); |
270 | |
271 | if (sublen > slen) |
272 | return 1; |
273 | |
274 | return memcmp(s + slen - sublen, sub, sublen); |
275 | } |
276 | |
277 | void do_config_file(char *filename) |
278 | { |
279 | struct stat st; |
280 | int fd; |
281 | void *map; |
282 | |
283 | fd = open(filename, O_RDONLY); |
284 | if (fd < 0) { |
285 | fprintf(stderr, "fixdep: "); |
286 | perror(filename); |
287 | exit(2); |
288 | } |
289 | fstat(fd, &st); |
290 | if (st.st_size == 0) { |
291 | close(fd); |
292 | return; |
293 | } |
294 | map = mmap(NULL, st.st_size, PROT_READ, MAP_PRIVATE, fd, 0); |
295 | if ((long) map == -1) { |
296 | perror("fixdep: mmap"); |
297 | close(fd); |
298 | return; |
299 | } |
300 | |
301 | parse_config_file(map, st.st_size); |
302 | |
303 | munmap(map, st.st_size); |
304 | |
305 | close(fd); |
306 | } |
307 | |
308 | void parse_dep_file(void *map, size_t len) |
309 | { |
310 | char *m = map; |
311 | char *end = m + len; |
312 | char *p; |
313 | char s[PATH_MAX]; |
314 | |
315 | p = memchr(m, ':', len); |
316 | if (!p) { |
317 | fprintf(stderr, "fixdep: parse error\n"); |
318 | exit(1); |
319 | } |
320 | memcpy(s, m, p-m); s[p-m] = 0; |
321 | printf("deps_%s := \\\n", target); |
322 | m = p+1; |
323 | |
324 | clear_config(); |
325 | |
326 | while (m < end) { |
327 | while (m < end && (*m == ' ' || *m == '\\' || *m == '\n')) |
328 | m++; |
329 | p = m; |
330 | while (p < end && *p != ' ') p++; |
331 | if (p == end) { |
332 | do p--; while (!isalnum(*p)); |
333 | p++; |
334 | } |
335 | memcpy(s, m, p-m); s[p-m] = 0; |
336 | if (strrcmp(s, "include/autoconf.h") && |
337 | strrcmp(s, "arch/um/include/uml-config.h") && |
338 | strrcmp(s, ".ver")) { |
339 | printf(" %s \\\n", s); |
340 | do_config_file(s); |
341 | } |
342 | m = p + 1; |
343 | } |
344 | printf("\n%s: $(deps_%s)\n\n", target, target); |
345 | printf("$(deps_%s):\n", target); |
346 | } |
347 | |
348 | void print_deps(void) |
349 | { |
350 | struct stat st; |
351 | int fd; |
352 | void *map; |
353 | |
354 | fd = open(depfile, O_RDONLY); |
355 | if (fd < 0) { |
356 | fprintf(stderr, "fixdep: "); |
357 | perror(depfile); |
358 | exit(2); |
359 | } |
360 | fstat(fd, &st); |
361 | if (st.st_size == 0) { |
362 | fprintf(stderr,"fixdep: %s is empty\n",depfile); |
363 | close(fd); |
364 | return; |
365 | } |
366 | map = mmap(NULL, st.st_size, PROT_READ, MAP_PRIVATE, fd, 0); |
367 | if ((long) map == -1) { |
368 | perror("fixdep: mmap"); |
369 | close(fd); |
370 | return; |
371 | } |
372 | |
373 | parse_dep_file(map, st.st_size); |
374 | |
375 | munmap(map, st.st_size); |
376 | |
377 | close(fd); |
378 | } |
379 | |
380 | void traps(void) |
381 | { |
382 | /* bbox: not needed |
383 | static char test[] __attribute__((aligned(sizeof(int)))) = "CONF"; |
384 | |
385 | if (*(int *)test != INT_CONF) { |
386 | fprintf(stderr, "fixdep: sizeof(int) != 4 or wrong endianess? %#x\n", |
387 | *(int *)test); |
388 | exit(2); |
389 | } |
390 | */ |
391 | } |
392 | |
393 | int main(int argc, char **argv) |
394 | { |
395 | traps(); |
396 | |
397 | if (argc != 4) |
398 | usage(); |
399 | |
400 | depfile = argv[1]; |
401 | target = argv[2]; |
402 | cmdline = argv[3]; |
403 | |
404 | print_cmdline(); |
405 | print_deps(); |
406 | |
407 | return 0; |
408 | } |