1 | // SPDX-License-Identifier: GPL-2.0 |
2 | /* |
3 | * "Optimize" a list of dependencies as spit out by gcc -MD |
4 | * for the build framework. |
5 | * |
6 | * Original author: |
7 | * Copyright 2002 by Kai Germaschewski <kai.germaschewski@gmx.de> |
8 | * |
9 | * This code has been borrowed from kbuild's fixdep (scripts/basic/fixdep.c), |
10 | * Please check it for detailed explanation. This fixdep borow only the |
11 | * base transformation of dependecies without the CONFIG mangle. |
12 | */ |
13 | |
14 | #include <sys/types.h> |
15 | #include <sys/stat.h> |
16 | #include <sys/mman.h> |
17 | #include <unistd.h> |
18 | #include <fcntl.h> |
19 | #include <string.h> |
20 | #include <stdlib.h> |
21 | #include <stdio.h> |
22 | #include <limits.h> |
23 | |
24 | char *target; |
25 | char *depfile; |
26 | char *cmdline; |
27 | |
28 | static void usage(void) |
29 | { |
30 | fprintf(stderr, "Usage: fixdep <depfile> <target> <cmdline>\n" ); |
31 | exit(1); |
32 | } |
33 | |
34 | /* |
35 | * Print out the commandline prefixed with cmd_<target filename> := |
36 | */ |
37 | static void print_cmdline(void) |
38 | { |
39 | printf("cmd_%s := %s\n\n" , target, cmdline); |
40 | } |
41 | |
42 | /* |
43 | * Important: The below generated source_foo.o and deps_foo.o variable |
44 | * assignments are parsed not only by make, but also by the rather simple |
45 | * parser in scripts/mod/sumversion.c. |
46 | */ |
47 | static void parse_dep_file(void *map, size_t len) |
48 | { |
49 | char *m = map; |
50 | char *end = m + len; |
51 | char *p; |
52 | char s[PATH_MAX]; |
53 | int is_target, has_target = 0; |
54 | int saw_any_target = 0; |
55 | int is_first_dep = 0; |
56 | |
57 | while (m < end) { |
58 | /* Skip any "white space" */ |
59 | while (m < end && (*m == ' ' || *m == '\\' || *m == '\n')) |
60 | m++; |
61 | /* Find next "white space" */ |
62 | p = m; |
63 | while (p < end && *p != ' ' && *p != '\\' && *p != '\n') |
64 | p++; |
65 | /* Is the token we found a target name? */ |
66 | is_target = (*(p-1) == ':'); |
67 | /* Don't write any target names into the dependency file */ |
68 | if (is_target) { |
69 | /* The /next/ file is the first dependency */ |
70 | is_first_dep = 1; |
71 | has_target = 1; |
72 | } else if (has_target) { |
73 | /* Save this token/filename */ |
74 | memcpy(s, m, p-m); |
75 | s[p - m] = 0; |
76 | |
77 | /* |
78 | * Do not list the source file as dependency, |
79 | * so that kbuild is not confused if a .c file |
80 | * is rewritten into .S or vice versa. Storing |
81 | * it in source_* is needed for modpost to |
82 | * compute srcversions. |
83 | */ |
84 | if (is_first_dep) { |
85 | /* |
86 | * If processing the concatenation of |
87 | * multiple dependency files, only |
88 | * process the first target name, which |
89 | * will be the original source name, |
90 | * and ignore any other target names, |
91 | * which will be intermediate temporary |
92 | * files. |
93 | */ |
94 | if (!saw_any_target) { |
95 | saw_any_target = 1; |
96 | printf("source_%s := %s\n\n" , |
97 | target, s); |
98 | printf("deps_%s := \\\n" , |
99 | target); |
100 | } |
101 | is_first_dep = 0; |
102 | } else |
103 | printf(" %s \\\n" , s); |
104 | } |
105 | /* |
106 | * Start searching for next token immediately after the first |
107 | * "whitespace" character that follows this token. |
108 | */ |
109 | m = p + 1; |
110 | } |
111 | |
112 | if (!saw_any_target) { |
113 | fprintf(stderr, "fixdep: parse error; no targets found\n" ); |
114 | exit(1); |
115 | } |
116 | |
117 | printf("\n%s: $(deps_%s)\n\n" , target, target); |
118 | printf("$(deps_%s):\n" , target); |
119 | } |
120 | |
121 | static void print_deps(void) |
122 | { |
123 | struct stat st; |
124 | int fd; |
125 | void *map; |
126 | |
127 | fd = open(depfile, O_RDONLY); |
128 | if (fd < 0) { |
129 | fprintf(stderr, "fixdep: error opening depfile: " ); |
130 | perror(depfile); |
131 | exit(2); |
132 | } |
133 | if (fstat(fd, &st) < 0) { |
134 | fprintf(stderr, "fixdep: error fstat'ing depfile: " ); |
135 | perror(depfile); |
136 | exit(2); |
137 | } |
138 | if (st.st_size == 0) { |
139 | fprintf(stderr, "fixdep: %s is empty\n" , depfile); |
140 | close(fd); |
141 | return; |
142 | } |
143 | map = mmap(NULL, st.st_size, PROT_READ, MAP_PRIVATE, fd, 0); |
144 | if ((long) map == -1) { |
145 | perror("fixdep: mmap" ); |
146 | close(fd); |
147 | return; |
148 | } |
149 | |
150 | parse_dep_file(map, st.st_size); |
151 | |
152 | munmap(map, st.st_size); |
153 | |
154 | close(fd); |
155 | } |
156 | |
157 | int main(int argc, char **argv) |
158 | { |
159 | if (argc != 4) |
160 | usage(); |
161 | |
162 | depfile = argv[1]; |
163 | target = argv[2]; |
164 | cmdline = argv[3]; |
165 | |
166 | print_cmdline(); |
167 | print_deps(); |
168 | |
169 | return 0; |
170 | } |
171 | |