| /* |
| * "Optimize" a list of dependencies as spit out by gcc -MD |
| * for the kernel build |
| * =========================================================================== |
| * |
| * Author Kai Germaschewski |
| * Copyright 2002 by Kai Germaschewski <kai.germaschewski@gmx.de> |
| * |
| * This software may be used and distributed according to the terms |
| * of the GNU General Public License, incorporated herein by reference. |
| * |
| * |
| * Introduction: |
| * |
| * gcc produces a very nice and correct list of dependencies which |
| * tells make when to remake a file. |
| * |
| * To use this list as-is however has the drawback that virtually |
| * every file in the kernel includes autoconf.h. |
| * |
| * If the user re-runs make *config, autoconf.h will be |
| * regenerated. make notices that and will rebuild every file which |
| * includes autoconf.h, i.e. basically all files. This is extremely |
| * annoying if the user just changed CONFIG_HIS_DRIVER from n to m. |
| * |
| * So we play the same trick that "mkdep" played before. We replace |
| * the dependency on autoconf.h by a dependency on every config |
| * option which is mentioned in any of the listed prequisites. |
| * |
| * kconfig populates a tree in include/config/ with an empty file |
| * for each config symbol and when the configuration is updated |
| * the files representing changed config options are touched |
| * which then let make pick up the changes and the files that use |
| * the config symbols are rebuilt. |
| * |
| * So if the user changes his CONFIG_HIS_DRIVER option, only the objects |
| * which depend on "include/linux/config/his/driver.h" will be rebuilt, |
| * so most likely only his driver ;-) |
| * |
| * The idea above dates, by the way, back to Michael E Chastain, AFAIK. |
| * |
| * So to get dependencies right, there are two issues: |
| * o if any of the files the compiler read changed, we need to rebuild |
| * o if the command line given to the compile the file changed, we |
| * better rebuild as well. |
| * |
| * The former is handled by using the -MD output, the later by saving |
| * the command line used to compile the old object and comparing it |
| * to the one we would now use. |
| * |
| * Again, also this idea is pretty old and has been discussed on |
| * kbuild-devel a long time ago. I don't have a sensibly working |
| * internet connection right now, so I rather don't mention names |
| * without double checking. |
| * |
| * This code here has been based partially based on mkdep.c, which |
| * says the following about its history: |
| * |
| * Copyright abandoned, Michael Chastain, <mailto:mec@shout.net>. |
| * This is a C version of syncdep.pl by Werner Almesberger. |
| * |
| * |
| * It is invoked as |
| * |
| * fixdep <depfile> <target> <cmdline> |
| * |
| * and will read the dependency file <depfile> |
| * |
| * The transformed dependency snipped is written to stdout. |
| * |
| * It first generates a line |
| * |
| * cmd_<target> = <cmdline> |
| * |
| * and then basically copies the .<target>.d file to stdout, in the |
| * process filtering out the dependency on autoconf.h and adding |
| * dependencies on include/config/my/option.h for every |
| * CONFIG_MY_OPTION encountered in any of the prequisites. |
| * |
| * It will also filter out all the dependencies on *.ver. We need |
| * to make sure that the generated version checksum are globally up |
| * to date before even starting the recursive build, so it's too late |
| * at this point anyway. |
| * |
| * The algorithm to grep for "CONFIG_..." is bit unusual, but should |
| * be fast ;-) We don't even try to really parse the header files, but |
| * merely grep, i.e. if CONFIG_FOO is mentioned in a comment, it will |
| * be picked up as well. It's not a problem with respect to |
| * correctness, since that can only give too many dependencies, thus |
| * we cannot miss a rebuild. Since people tend to not mention totally |
| * unrelated CONFIG_ options all over the place, it's not an |
| * efficiency problem either. |
| * |
| * (Note: it'd be easy to port over the complete mkdep state machine, |
| * but I don't think the added complexity is worth it) |
| */ |
| /* |
| * Note 2: if somebody writes HELLO_CONFIG_BOOM in a file, it will depend onto |
| * CONFIG_BOOM. This could seem a bug (not too hard to fix), but please do not |
| * fix it! Some UserModeLinux files (look at arch/um/) call CONFIG_BOOM as |
| * UML_CONFIG_BOOM, to avoid conflicts with /usr/include/linux/autoconf.h, |
| * through arch/um/include/uml-config.h; this fixdep "bug" makes sure that |
| * those files will have correct dependencies. |
| */ |
| |
| #include <sys/types.h> |
| #include <sys/stat.h> |
| #include <sys/mman.h> |
| #include <unistd.h> |
| #include <fcntl.h> |
| #include <string.h> |
| #include <stdlib.h> |
| #include <stdio.h> |
| #include <limits.h> |
| #include <ctype.h> |
| #include <arpa/inet.h> |
| |
| #define INT_CONF ntohl(0x434f4e46) |
| #define INT_ONFI ntohl(0x4f4e4649) |
| #define INT_NFIG ntohl(0x4e464947) |
| #define INT_FIG_ ntohl(0x4649475f) |
| |
| char *target; |
| char *depfile; |
| char *cmdline; |
| |
| static void usage(void) |
| { |
| fprintf(stderr, "Usage: fixdep <depfile> <target> <cmdline>\n"); |
| exit(1); |
| } |
| |
| /* |
| * Print out the commandline prefixed with cmd_<target filename> := |
| */ |
| static void print_cmdline(void) |
| { |
| printf("cmd_%s := %s\n\n", target, cmdline); |
| } |
| |
| struct item { |
| struct item *next; |
| unsigned int len; |
| unsigned int hash; |
| char name[0]; |
| }; |
| |
| #define HASHSZ 256 |
| static struct item *hashtab[HASHSZ]; |
| |
| static unsigned int strhash(const char *str, unsigned int sz) |
| { |
| /* fnv32 hash */ |
| unsigned int i, hash = 2166136261U; |
| |
| for (i = 0; i < sz; i++) |
| hash = (hash ^ str[i]) * 0x01000193; |
| return hash; |
| } |
| |
| /* |
| * Lookup a value in the configuration string. |
| */ |
| static int is_defined_config(const char *name, int len, unsigned int hash) |
| { |
| struct item *aux; |
| |
| for (aux = hashtab[hash % HASHSZ]; aux; aux = aux->next) { |
| if (aux->hash == hash && aux->len == len && |
| memcmp(aux->name, name, len) == 0) |
| return 1; |
| } |
| return 0; |
| } |
| |
| /* |
| * Add a new value to the configuration string. |
| */ |
| static void define_config(const char *name, int len, unsigned int hash) |
| { |
| struct item *aux = malloc(sizeof(*aux) + len); |
| |
| if (!aux) { |
| perror("fixdep:malloc"); |
| exit(1); |
| } |
| memcpy(aux->name, name, len); |
| aux->len = len; |
| aux->hash = hash; |
| aux->next = hashtab[hash % HASHSZ]; |
| hashtab[hash % HASHSZ] = aux; |
| } |
| |
| /* |
| * Clear the set of configuration strings. |
| */ |
| static void clear_config(void) |
| { |
| struct item *aux, *next; |
| unsigned int i; |
| |
| for (i = 0; i < HASHSZ; i++) { |
| for (aux = hashtab[i]; aux; aux = next) { |
| next = aux->next; |
| free(aux); |
| } |
| hashtab[i] = NULL; |
| } |
| } |
| |
| /* |
| * Record the use of a CONFIG_* word. |
| */ |
| static void use_config(const char *m, int slen) |
| { |
| unsigned int hash = strhash(m, slen); |
| int c, i; |
| |
| if (is_defined_config(m, slen, hash)) |
| return; |
| |
| define_config(m, slen, hash); |
| |
| printf(" $(wildcard include/config/"); |
| for (i = 0; i < slen; i++) { |
| c = m[i]; |
| if (c == '_') |
| c = '/'; |
| else |
| c = tolower(c); |
| putchar(c); |
| } |
| printf(".h) \\\n"); |
| } |
| |
| static void parse_config_file(const char *map, size_t len) |
| { |
| const int *end = (const int *) (map + len); |
| /* start at +1, so that p can never be < map */ |
| const int *m = (const int *) map + 1; |
| const char *p, *q; |
| |
| for (; m < end; m++) { |
| if (*m == INT_CONF) { p = (char *) m ; goto conf; } |
| if (*m == INT_ONFI) { p = (char *) m-1; goto conf; } |
| if (*m == INT_NFIG) { p = (char *) m-2; goto conf; } |
| if (*m == INT_FIG_) { p = (char *) m-3; goto conf; } |
| continue; |
| conf: |
| if (p > map + len - 7) |
| continue; |
| if (memcmp(p, "CONFIG_", 7)) |
| continue; |
| for (q = p + 7; q < map + len; q++) { |
| if (!(isalnum(*q) || *q == '_')) |
| goto found; |
| } |
| continue; |
| |
| found: |
| if (!memcmp(q - 7, "_MODULE", 7)) |
| q -= 7; |
| if( (q-p-7) < 0 ) |
| continue; |
| use_config(p+7, q-p-7); |
| } |
| } |
| |
| /* test is s ends in sub */ |
| static int strrcmp(char *s, char *sub) |
| { |
| int slen = strlen(s); |
| int sublen = strlen(sub); |
| |
| if (sublen > slen) |
| return 1; |
| |
| return memcmp(s + slen - sublen, sub, sublen); |
| } |
| |
| static void do_config_file(const char *filename) |
| { |
| struct stat st; |
| int fd; |
| void *map; |
| |
| fd = open(filename, O_RDONLY); |
| if (fd < 0) { |
| fprintf(stderr, "fixdep: error opening config file: "); |
| perror(filename); |
| exit(2); |
| } |
| fstat(fd, &st); |
| if (st.st_size == 0) { |
| close(fd); |
| return; |
| } |
| map = mmap(NULL, st.st_size, PROT_READ, MAP_PRIVATE, fd, 0); |
| if ((long) map == -1) { |
| perror("fixdep: mmap"); |
| close(fd); |
| return; |
| } |
| |
| parse_config_file(map, st.st_size); |
| |
| munmap(map, st.st_size); |
| |
| close(fd); |
| } |
| |
| /* |
| * Important: The below generated source_foo.o and deps_foo.o variable |
| * assignments are parsed not only by make, but also by the rather simple |
| * parser in scripts/mod/sumversion.c. |
| */ |
| static void parse_dep_file(void *map, size_t len) |
| { |
| char *m = map; |
| char *end = m + len; |
| char *p; |
| char s[PATH_MAX]; |
| int first; |
| |
| p = strchr(m, ':'); |
| if (!p) { |
| fprintf(stderr, "fixdep: parse error\n"); |
| exit(1); |
| } |
| memcpy(s, m, p-m); s[p-m] = 0; |
| m = p+1; |
| |
| clear_config(); |
| |
| first = 1; |
| while (m < end) { |
| while (m < end && (*m == ' ' || *m == '\\' || *m == '\n')) |
| m++; |
| p = m; |
| while (p < end && *p != ' ') p++; |
| if (p == end) { |
| do p--; while (!isalnum(*p)); |
| p++; |
| } |
| memcpy(s, m, p-m); s[p-m] = 0; |
| if (strrcmp(s, "include/generated/autoconf.h") && |
| strrcmp(s, "arch/um/include/uml-config.h") && |
| strrcmp(s, "include/linux/kconfig.h") && |
| strrcmp(s, ".ver")) { |
| /* |
| * Do not list the source file as dependency, so that |
| * kbuild is not confused if a .c file is rewritten |
| * into .S or vice versa. Storing it in source_* is |
| * needed for modpost to compute srcversions. |
| */ |
| if (first) { |
| printf("source_%s := %s\n\n", target, s); |
| printf("deps_%s := \\\n", target); |
| } else |
| printf(" %s \\\n", s); |
| do_config_file(s); |
| } |
| first = 0; |
| m = p + 1; |
| } |
| printf("\n%s: $(deps_%s)\n\n", target, target); |
| printf("$(deps_%s):\n", target); |
| } |
| |
| static void print_deps(void) |
| { |
| struct stat st; |
| int fd; |
| void *map; |
| |
| fd = open(depfile, O_RDONLY); |
| if (fd < 0) { |
| fprintf(stderr, "fixdep: error opening depfile: "); |
| perror(depfile); |
| exit(2); |
| } |
| if (fstat(fd, &st) < 0) { |
| fprintf(stderr, "fixdep: error fstat'ing depfile: "); |
| perror(depfile); |
| exit(2); |
| } |
| if (st.st_size == 0) { |
| fprintf(stderr,"fixdep: %s is empty\n",depfile); |
| close(fd); |
| return; |
| } |
| map = mmap(NULL, st.st_size, PROT_READ, MAP_PRIVATE, fd, 0); |
| if ((long) map == -1) { |
| perror("fixdep: mmap"); |
| close(fd); |
| return; |
| } |
| |
| parse_dep_file(map, st.st_size); |
| |
| munmap(map, st.st_size); |
| |
| close(fd); |
| } |
| |
| static void traps(void) |
| { |
| static char test[] __attribute__((aligned(sizeof(int)))) = "CONF"; |
| int *p = (int *)test; |
| |
| if (*p != INT_CONF) { |
| fprintf(stderr, "fixdep: sizeof(int) != 4 or wrong endianess? %#x\n", |
| *p); |
| exit(2); |
| } |
| } |
| |
| int main(int argc, char *argv[]) |
| { |
| traps(); |
| |
| if (argc != 4) |
| usage(); |
| |
| depfile = argv[1]; |
| target = argv[2]; |
| cmdline = argv[3]; |
| |
| print_cmdline(); |
| print_deps(); |
| |
| return 0; |
| } |