File: /usr/src/linux/scripts/split-include.c
1 /*
2 * split-include.c
3 *
4 * Copyright abandoned, Michael Chastain, <mailto:mec@shout.net>.
5 * This is a C version of syncdep.pl by Werner Almesberger.
6 *
7 * This program takes autoconf.h as input and outputs a directory full
8 * of one-line include files, merging onto the old values.
9 *
10 * Think of the configuration options as key-value pairs. Then there
11 * are five cases:
12 *
13 * key old value new value action
14 *
15 * KEY-1 VALUE-1 VALUE-1 leave file alone
16 * KEY-2 VALUE-2A VALUE-2B write VALUE-2B into file
17 * KEY-3 - VALUE-3 write VALUE-3 into file
18 * KEY-4 VALUE-4 - write an empty file
19 * KEY-5 (empty) - leave old empty file alone
20 */
21
22 #include <sys/stat.h>
23 #include <sys/types.h>
24
25 #include <ctype.h>
26 #include <errno.h>
27 #include <fcntl.h>
28 #include <stdio.h>
29 #include <stdlib.h>
30 #include <string.h>
31 #include <unistd.h>
32
33 #define ERROR_EXIT(strExit) \
34 { \
35 const int errnoSave = errno; \
36 fprintf(stderr, "%s: ", str_my_name); \
37 errno = errnoSave; \
38 perror((strExit)); \
39 exit(1); \
40 }
41
42
43
44 int main(int argc, const char * argv [])
45 {
46 const char * str_my_name;
47 const char * str_file_autoconf;
48 const char * str_dir_config;
49
50 FILE * fp_config;
51 FILE * fp_target;
52 FILE * fp_find;
53
54 int buffer_size;
55
56 char * line;
57 char * old_line;
58 char * list_target;
59 char * ptarget;
60
61 struct stat stat_buf;
62
63 /* Check arg count. */
64 if (argc != 3)
65 {
66 fprintf(stderr, "%s: wrong number of arguments.\n", argv[0]);
67 exit(1);
68 }
69
70 str_my_name = argv[0];
71 str_file_autoconf = argv[1];
72 str_dir_config = argv[2];
73
74 /* Find a buffer size. */
75 if (stat(str_file_autoconf, &stat_buf) != 0)
76 ERROR_EXIT(str_file_autoconf);
77 buffer_size = 2 * stat_buf.st_size + 4096;
78
79 /* Allocate buffers. */
80 if ( (line = malloc(buffer_size)) == NULL
81 || (old_line = malloc(buffer_size)) == NULL
82 || (list_target = malloc(buffer_size)) == NULL )
83 ERROR_EXIT(str_file_autoconf);
84
85 /* Open autoconfig file. */
86 if ((fp_config = fopen(str_file_autoconf, "r")) == NULL)
87 ERROR_EXIT(str_file_autoconf);
88
89 /* Make output directory if needed. */
90 if (stat(str_dir_config, &stat_buf) != 0)
91 {
92 if (mkdir(str_dir_config, 0755) != 0)
93 ERROR_EXIT(str_dir_config);
94 }
95
96 /* Change to output directory. */
97 if (chdir(str_dir_config) != 0)
98 ERROR_EXIT(str_dir_config);
99
100 /* Put initial separator into target list. */
101 ptarget = list_target;
102 *ptarget++ = '\n';
103
104 /* Read config lines. */
105 while (fgets(line, buffer_size, fp_config))
106 {
107 const char * str_config;
108 int is_same;
109 int itarget;
110
111 if (line[0] != '#')
112 continue;
113 if ((str_config = strstr(line, "CONFIG_")) == NULL)
114 continue;
115
116 /* Make the output file name. */
117 str_config += sizeof("CONFIG_") - 1;
118 for (itarget = 0; !isspace(str_config[itarget]); itarget++)
119 {
120 char c = str_config[itarget];
121 if (isupper(c)) c = tolower(c);
122 if (c == '_') c = '/';
123 ptarget[itarget] = c;
124 }
125 ptarget[itarget++] = '.';
126 ptarget[itarget++] = 'h';
127 ptarget[itarget++] = '\0';
128
129 /* Check for existing file. */
130 is_same = 0;
131 if ((fp_target = fopen(ptarget, "r")) != NULL)
132 {
133 fgets(old_line, buffer_size, fp_target);
134 if (fclose(fp_target) != 0)
135 ERROR_EXIT(ptarget);
136 if (!strcmp(line, old_line))
137 is_same = 1;
138 }
139
140 if (!is_same)
141 {
142 /* Auto-create directories. */
143 int islash;
144 for (islash = 0; islash < itarget; islash++)
145 {
146 if (ptarget[islash] == '/')
147 {
148 ptarget[islash] = '\0';
149 if (stat(ptarget, &stat_buf) != 0
150 && mkdir(ptarget, 0755) != 0)
151 ERROR_EXIT( ptarget );
152 ptarget[islash] = '/';
153 }
154 }
155
156 /* Write the file. */
157 if ((fp_target = fopen(ptarget, "w" )) == NULL)
158 ERROR_EXIT(ptarget);
159 fputs(line, fp_target);
160 if (ferror(fp_target) || fclose(fp_target) != 0)
161 ERROR_EXIT(ptarget);
162 }
163
164 /* Update target list */
165 ptarget += itarget;
166 *(ptarget-1) = '\n';
167 }
168
169 /*
170 * Close autoconfig file.
171 * Terminate the target list.
172 */
173 if (fclose(fp_config) != 0)
174 ERROR_EXIT(str_file_autoconf);
175 *ptarget = '\0';
176
177 /*
178 * Fix up existing files which have no new value.
179 * This is Case 4 and Case 5.
180 *
181 * I re-read the tree and filter it against list_target.
182 * This is crude. But it avoids data copies. Also, list_target
183 * is compact and contiguous, so it easily fits into cache.
184 *
185 * Notice that list_target contains strings separated by \n,
186 * with a \n before the first string and after the last.
187 * fgets gives the incoming names a terminating \n.
188 * So by having an initial \n, strstr will find exact matches.
189 */
190
191 fp_find = popen("find * -type f -print", "r");
192 if (fp_find == 0)
193 ERROR_EXIT( "find" );
194
195 line[0] = '\n';
196 while (fgets(line+1, buffer_size, fp_find))
197 {
198 if (strstr(list_target, line) == NULL)
199 {
200 /*
201 * This is an old file with no CONFIG_* flag in autoconf.h.
202 */
203
204 /* First strip the \n. */
205 line[strlen(line)-1] = '\0';
206
207 /* Grab size. */
208 if (stat(line+1, &stat_buf) != 0)
209 ERROR_EXIT(line);
210
211 /* If file is not empty, make it empty and give it a fresh date. */
212 if (stat_buf.st_size != 0)
213 {
214 if ((fp_target = fopen(line+1, "w")) == NULL)
215 ERROR_EXIT(line);
216 if (fclose(fp_target) != 0)
217 ERROR_EXIT(line);
218 }
219 }
220 }
221
222 if (pclose(fp_find) != 0)
223 ERROR_EXIT("find");
224
225 return 0;
226 }
227