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, has_target = 0; 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 has_target = 1; 71 } else if (has_target) { 72 /* Save this token/filename */ 73 memcpy(s, m, p-m); 74 s[p - m] = 0; 75 76 /* 77 * Do not list the source file as dependency, 78 * so that kbuild is not confused if a .c file 79 * is rewritten into .S or vice versa. Storing 80 * it in source_* is needed for modpost to 81 * compute srcversions. 82 */ 83 if (is_first_dep) { 84 /* 85 * If processing the concatenation of 86 * multiple dependency files, only 87 * process the first target name, which 88 * will be the original source name, 89 * and ignore any other target names, 90 * which will be intermediate temporary 91 * files. 92 */ 93 if (!saw_any_target) { 94 saw_any_target = 1; 95 printf("source_%s := %s\n\n", 96 target, s); 97 printf("deps_%s := \\\n", 98 target); 99 } 100 is_first_dep = 0; 101 } else 102 printf(" %s \\\n", s); 103 } 104 /* 105 * Start searching for next token immediately after the first 106 * "whitespace" character that follows this token. 107 */ 108 m = p + 1; 109 } 110 111 if (!saw_any_target) { 112 fprintf(stderr, "fixdep: parse error; no targets found\n"); 113 exit(1); 114 } 115 116 printf("\n%s: $(deps_%s)\n\n", target, target); 117 printf("$(deps_%s):\n", target); 118 } 119 120 static void print_deps(void) 121 { 122 struct stat st; 123 int fd; 124 void *map; 125 126 fd = open(depfile, O_RDONLY); 127 if (fd < 0) { 128 fprintf(stderr, "fixdep: error opening depfile: "); 129 perror(depfile); 130 exit(2); 131 } 132 if (fstat(fd, &st) < 0) { 133 fprintf(stderr, "fixdep: error fstat'ing depfile: "); 134 perror(depfile); 135 exit(2); 136 } 137 if (st.st_size == 0) { 138 fprintf(stderr, "fixdep: %s is empty\n", depfile); 139 close(fd); 140 return; 141 } 142 map = mmap(NULL, st.st_size, PROT_READ, MAP_PRIVATE, fd, 0); 143 if ((long) map == -1) { 144 perror("fixdep: mmap"); 145 close(fd); 146 return; 147 } 148 149 parse_dep_file(map, st.st_size); 150 151 munmap(map, st.st_size); 152 153 close(fd); 154 } 155 156 int main(int argc, char **argv) 157 { 158 if (argc != 4) 159 usage(); 160 161 depfile = argv[1]; 162 target = argv[2]; 163 cmdline = argv[3]; 164 165 print_cmdline(); 166 print_deps(); 167 168 return 0; 169 } 170