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Diffstat (limited to 'scripts/basic/fixdep.c')
-rw-r--r-- | scripts/basic/fixdep.c | 390 |
1 files changed, 390 insertions, 0 deletions
diff --git a/scripts/basic/fixdep.c b/scripts/basic/fixdep.c new file mode 100644 index 000000000000..7f42c5d8a5a2 --- /dev/null +++ b/scripts/basic/fixdep.c | |||
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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 <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 | #define INT_CONF ntohl(0x434f4e46) | ||
118 | #define INT_ONFI ntohl(0x4f4e4649) | ||
119 | #define INT_NFIG ntohl(0x4e464947) | ||
120 | #define INT_FIG_ ntohl(0x4649475f) | ||
121 | |||
122 | char *target; | ||
123 | char *depfile; | ||
124 | char *cmdline; | ||
125 | |||
126 | void usage(void) | ||
127 | |||
128 | { | ||
129 | fprintf(stderr, "Usage: fixdep <depfile> <target> <cmdline>\n"); | ||
130 | exit(1); | ||
131 | } | ||
132 | |||
133 | void print_cmdline(void) | ||
134 | { | ||
135 | printf("cmd_%s := %s\n\n", target, cmdline); | ||
136 | } | ||
137 | |||
138 | char * str_config = NULL; | ||
139 | int size_config = 0; | ||
140 | int len_config = 0; | ||
141 | |||
142 | /* | ||
143 | * Grow the configuration string to a desired length. | ||
144 | * Usually the first growth is plenty. | ||
145 | */ | ||
146 | void grow_config(int len) | ||
147 | { | ||
148 | while (len_config + len > size_config) { | ||
149 | if (size_config == 0) | ||
150 | size_config = 2048; | ||
151 | str_config = realloc(str_config, size_config *= 2); | ||
152 | if (str_config == NULL) | ||
153 | { perror("fixdep:malloc"); exit(1); } | ||
154 | } | ||
155 | } | ||
156 | |||
157 | |||
158 | |||
159 | /* | ||
160 | * Lookup a value in the configuration string. | ||
161 | */ | ||
162 | int is_defined_config(const char * name, int len) | ||
163 | { | ||
164 | const char * pconfig; | ||
165 | const char * plast = str_config + len_config - len; | ||
166 | for ( pconfig = str_config + 1; pconfig < plast; pconfig++ ) { | ||
167 | if (pconfig[ -1] == '\n' | ||
168 | && pconfig[len] == '\n' | ||
169 | && !memcmp(pconfig, name, len)) | ||
170 | return 1; | ||
171 | } | ||
172 | return 0; | ||
173 | } | ||
174 | |||
175 | /* | ||
176 | * Add a new value to the configuration string. | ||
177 | */ | ||
178 | void define_config(const char * name, int len) | ||
179 | { | ||
180 | grow_config(len + 1); | ||
181 | |||
182 | memcpy(str_config+len_config, name, len); | ||
183 | len_config += len; | ||
184 | str_config[len_config++] = '\n'; | ||
185 | } | ||
186 | |||
187 | /* | ||
188 | * Clear the set of configuration strings. | ||
189 | */ | ||
190 | void clear_config(void) | ||
191 | { | ||
192 | len_config = 0; | ||
193 | define_config("", 0); | ||
194 | } | ||
195 | |||
196 | /* | ||
197 | * Record the use of a CONFIG_* word. | ||
198 | */ | ||
199 | void use_config(char *m, int slen) | ||
200 | { | ||
201 | char s[PATH_MAX]; | ||
202 | char *p; | ||
203 | |||
204 | if (is_defined_config(m, slen)) | ||
205 | return; | ||
206 | |||
207 | define_config(m, slen); | ||
208 | |||
209 | memcpy(s, m, slen); s[slen] = 0; | ||
210 | |||
211 | for (p = s; p < s + slen; p++) { | ||
212 | if (*p == '_') | ||
213 | *p = '/'; | ||
214 | else | ||
215 | *p = tolower((unsigned char)*p); | ||
216 | } | ||
217 | printf(" $(wildcard include/config/%s.h) \\\n", s); | ||
218 | } | ||
219 | |||
220 | void parse_config_file(signed char *map, size_t len) | ||
221 | { | ||
222 | int *end = (int *) (map + len); | ||
223 | /* start at +1, so that p can never be < map */ | ||
224 | int *m = (int *) map + 1; | ||
225 | signed char *p, *q; | ||
226 | |||
227 | for (; m < end; m++) { | ||
228 | if (*m == INT_CONF) { p = (signed char *) m ; goto conf; } | ||
229 | if (*m == INT_ONFI) { p = (signed char *) m-1; goto conf; } | ||
230 | if (*m == INT_NFIG) { p = (signed char *) m-2; goto conf; } | ||
231 | if (*m == INT_FIG_) { p = (signed char *) m-3; goto conf; } | ||
232 | continue; | ||
233 | conf: | ||
234 | if (p > map + len - 7) | ||
235 | continue; | ||
236 | if (memcmp(p, "CONFIG_", 7)) | ||
237 | continue; | ||
238 | for (q = p + 7; q < map + len; q++) { | ||
239 | if (!(isalnum(*q) || *q == '_')) | ||
240 | goto found; | ||
241 | } | ||
242 | continue; | ||
243 | |||
244 | found: | ||
245 | use_config(p+7, q-p-7); | ||
246 | } | ||
247 | } | ||
248 | |||
249 | /* test is s ends in sub */ | ||
250 | int strrcmp(char *s, char *sub) | ||
251 | { | ||
252 | int slen = strlen(s); | ||
253 | int sublen = strlen(sub); | ||
254 | |||
255 | if (sublen > slen) | ||
256 | return 1; | ||
257 | |||
258 | return memcmp(s + slen - sublen, sub, sublen); | ||
259 | } | ||
260 | |||
261 | void do_config_file(char *filename) | ||
262 | { | ||
263 | struct stat st; | ||
264 | int fd; | ||
265 | void *map; | ||
266 | |||
267 | fd = open(filename, O_RDONLY); | ||
268 | if (fd < 0) { | ||
269 | fprintf(stderr, "fixdep: "); | ||
270 | perror(filename); | ||
271 | exit(2); | ||
272 | } | ||
273 | fstat(fd, &st); | ||
274 | if (st.st_size == 0) { | ||
275 | close(fd); | ||
276 | return; | ||
277 | } | ||
278 | map = mmap(NULL, st.st_size, PROT_READ, MAP_PRIVATE, fd, 0); | ||
279 | if ((long) map == -1) { | ||
280 | perror("fixdep: mmap"); | ||
281 | close(fd); | ||
282 | return; | ||
283 | } | ||
284 | |||
285 | parse_config_file(map, st.st_size); | ||
286 | |||
287 | munmap(map, st.st_size); | ||
288 | |||
289 | close(fd); | ||
290 | } | ||
291 | |||
292 | void parse_dep_file(void *map, size_t len) | ||
293 | { | ||
294 | signed char *m = map; | ||
295 | signed char *end = m + len; | ||
296 | signed char *p; | ||
297 | char s[PATH_MAX]; | ||
298 | |||
299 | p = strchr(m, ':'); | ||
300 | if (!p) { | ||
301 | fprintf(stderr, "fixdep: parse error\n"); | ||
302 | exit(1); | ||
303 | } | ||
304 | memcpy(s, m, p-m); s[p-m] = 0; | ||
305 | printf("deps_%s := \\\n", target); | ||
306 | m = p+1; | ||
307 | |||
308 | clear_config(); | ||
309 | |||
310 | while (m < end) { | ||
311 | while (m < end && (*m == ' ' || *m == '\\' || *m == '\n')) | ||
312 | m++; | ||
313 | p = m; | ||
314 | while (p < end && *p != ' ') p++; | ||
315 | if (p == end) { | ||
316 | do p--; while (!isalnum(*p)); | ||
317 | p++; | ||
318 | } | ||
319 | memcpy(s, m, p-m); s[p-m] = 0; | ||
320 | if (strrcmp(s, "include/linux/autoconf.h") && | ||
321 | strrcmp(s, "arch/um/include/uml-config.h") && | ||
322 | strrcmp(s, ".ver")) { | ||
323 | printf(" %s \\\n", s); | ||
324 | do_config_file(s); | ||
325 | } | ||
326 | m = p + 1; | ||
327 | } | ||
328 | printf("\n%s: $(deps_%s)\n\n", target, target); | ||
329 | printf("$(deps_%s):\n", target); | ||
330 | } | ||
331 | |||
332 | void print_deps(void) | ||
333 | { | ||
334 | struct stat st; | ||
335 | int fd; | ||
336 | void *map; | ||
337 | |||
338 | fd = open(depfile, O_RDONLY); | ||
339 | if (fd < 0) { | ||
340 | fprintf(stderr, "fixdep: "); | ||
341 | perror(depfile); | ||
342 | exit(2); | ||
343 | } | ||
344 | fstat(fd, &st); | ||
345 | if (st.st_size == 0) { | ||
346 | fprintf(stderr,"fixdep: %s is empty\n",depfile); | ||
347 | close(fd); | ||
348 | return; | ||
349 | } | ||
350 | map = mmap(NULL, st.st_size, PROT_READ, MAP_PRIVATE, fd, 0); | ||
351 | if ((long) map == -1) { | ||
352 | perror("fixdep: mmap"); | ||
353 | close(fd); | ||
354 | return; | ||
355 | } | ||
356 | |||
357 | parse_dep_file(map, st.st_size); | ||
358 | |||
359 | munmap(map, st.st_size); | ||
360 | |||
361 | close(fd); | ||
362 | } | ||
363 | |||
364 | void traps(void) | ||
365 | { | ||
366 | static char test[] __attribute__((aligned(sizeof(int)))) = "CONF"; | ||
367 | |||
368 | if (*(int *)test != INT_CONF) { | ||
369 | fprintf(stderr, "fixdep: sizeof(int) != 4 or wrong endianess? %#x\n", | ||
370 | *(int *)test); | ||
371 | exit(2); | ||
372 | } | ||
373 | } | ||
374 | |||
375 | int main(int argc, char *argv[]) | ||
376 | { | ||
377 | traps(); | ||
378 | |||
379 | if (argc != 4) | ||
380 | usage(); | ||
381 | |||
382 | depfile = argv[1]; | ||
383 | target = argv[2]; | ||
384 | cmdline = argv[3]; | ||
385 | |||
386 | print_cmdline(); | ||
387 | print_deps(); | ||
388 | |||
389 | return 0; | ||
390 | } | ||