1 /* 2 * "Optimize" a list of dependencies as spit out by gcc -MD 3 * for the build framework. 4 * 5 * Original author: 6 * Copyright 2002 by Kai Germaschewski <kai.germaschewski@gmx.de> 7 * 8 * This code has been borrowed from kbuild's fixdep (scripts/basic/fixdep.c), 9 * Please check it for detailed explanation. This fixdep borow only the 10 * base transformation of dependecies without the CONFIG mangle. 11 */ 12 13 #include <sys/types.h> 14 #include <sys/stat.h> 15 #include <sys/mman.h> 16 #include <unistd.h> 17 #include <fcntl.h> 18 #include <string.h> 19 #include <stdlib.h> 20 #include <stdio.h> 21 #include <limits.h> 22 23 char *target; 24 char *depfile; 25 char *cmdline; 26 27 static void usage(void) 28 { 29 fprintf(stderr, "Usage: fixdep <depfile> <target> <cmdline>\n"); 30 exit(1); 31 } 32 33 /* 34 * Print out the commandline prefixed with cmd_<target filename> := 35 */ 36 static void print_cmdline(void) 37 { 38 printf("cmd_%s := %s\n\n", target, cmdline); 39 } 40 41 /* 42 * Important: The below generated source_foo.o and deps_foo.o variable 43 * assignments are parsed not only by make, but also by the rather simple 44 * parser in scripts/mod/sumversion.c. 45 */ 46 static void parse_dep_file(void *map, size_t len) 47 { 48 char *m = map; 49 char *end = m + len; 50 char *p; 51 char s[PATH_MAX]; 52 int is_target; 53 int saw_any_target = 0; 54 int is_first_dep = 0; 55 56 while (m < end) { 57 /* Skip any "white space" */ 58 while (m < end && (*m == ' ' || *m == '\\' || *m == '\n')) 59 m++; 60 /* Find next "white space" */ 61 p = m; 62 while (p < end && *p != ' ' && *p != '\\' && *p != '\n') 63 p++; 64 /* Is the token we found a target name? */ 65 is_target = (*(p-1) == ':'); 66 /* Don't write any target names into the dependency file */ 67 if (is_target) { 68 /* The /next/ file is the first dependency */ 69 is_first_dep = 1; 70 } else { 71 /* Save this token/filename */ 72 memcpy(s, m, p-m); 73 s[p - m] = 0; 74 75 /* 76 * Do not list the source file as dependency, 77 * so that kbuild is not confused if a .c file 78 * is rewritten into .S or vice versa. Storing 79 * it in source_* is needed for modpost to 80 * compute srcversions. 81 */ 82 if (is_first_dep) { 83 /* 84 * If processing the concatenation of 85 * multiple dependency files, only 86 * process the first target name, which 87 * will be the original source name, 88 * and ignore any other target names, 89 * which will be intermediate temporary 90 * files. 91 */ 92 if (!saw_any_target) { 93 saw_any_target = 1; 94 printf("source_%s := %s\n\n", 95 target, s); 96 printf("deps_%s := \\\n", 97 target); 98 } 99 is_first_dep = 0; 100 } else 101 printf(" %s \\\n", s); 102 } 103 /* 104 * Start searching for next token immediately after the first 105 * "whitespace" character that follows this token. 106 */ 107 m = p + 1; 108 } 109 110 if (!saw_any_target) { 111 fprintf(stderr, "fixdep: parse error; no targets found\n"); 112 exit(1); 113 } 114 115 printf("\n%s: $(deps_%s)\n\n", target, target); 116 printf("$(deps_%s):\n", target); 117 } 118 119 static void print_deps(void) 120 { 121 struct stat st; 122 int fd; 123 void *map; 124 125 fd = open(depfile, O_RDONLY); 126 if (fd < 0) { 127 fprintf(stderr, "fixdep: error opening depfile: "); 128 perror(depfile); 129 exit(2); 130 } 131 if (fstat(fd, &st) < 0) { 132 fprintf(stderr, "fixdep: error fstat'ing depfile: "); 133 perror(depfile); 134 exit(2); 135 } 136 if (st.st_size == 0) { 137 fprintf(stderr, "fixdep: %s is empty\n", depfile); 138 close(fd); 139 return; 140 } 141 map = mmap(NULL, st.st_size, PROT_READ, MAP_PRIVATE, fd, 0); 142 if ((long) map == -1) { 143 perror("fixdep: mmap"); 144 close(fd); 145 return; 146 } 147 148 parse_dep_file(map, st.st_size); 149 150 munmap(map, st.st_size); 151 152 close(fd); 153 } 154 155 int main(int argc, char **argv) 156 { 157 if (argc != 4) 158 usage(); 159 160 depfile = argv[1]; 161 target = argv[2]; 162 cmdline = argv[3]; 163 164 print_cmdline(); 165 print_deps(); 166 167 return 0; 168 } 169