Rob Landley | 1bbc0cd | 2010-08-13 15:50:26 +0200 | [diff] [blame^] | 1 | /* vi: set sw=4 ts=4: */ |
| 2 | /* |
| 3 | * busybox patch applet to handle the unified diff format. |
| 4 | * Copyright (C) 2003 Glenn McGrath |
| 5 | * |
| 6 | * Licensed under the GPL v2 or later, see the file LICENSE in this tarball. |
| 7 | * |
| 8 | * This applet is written to work with patches generated by GNU diff, |
| 9 | * where there is equivalent functionality busybox patch shall behave |
| 10 | * as per GNU patch. |
| 11 | * |
| 12 | * There is a SUSv3 specification for patch, however it looks to be |
| 13 | * incomplete, it doesnt even mention unified diff format. |
| 14 | * http://www.opengroup.org/onlinepubs/007904975/utilities/patch.html |
| 15 | * |
| 16 | * Issues |
| 17 | * - Non-interactive |
| 18 | * - Patches must apply cleanly or patch (not just one hunk) will fail. |
| 19 | * - Reject file isnt saved |
| 20 | */ |
| 21 | |
| 22 | #include "libbb.h" |
| 23 | |
| 24 | static unsigned copy_lines(FILE *src_stream, FILE *dst_stream, unsigned lines_count) |
| 25 | { |
| 26 | while (src_stream && lines_count) { |
| 27 | char *line; |
| 28 | line = xmalloc_fgets(src_stream); |
| 29 | if (line == NULL) { |
| 30 | break; |
| 31 | } |
| 32 | if (fputs(line, dst_stream) == EOF) { |
| 33 | bb_perror_msg_and_die("error writing to new file"); |
| 34 | } |
| 35 | free(line); |
| 36 | lines_count--; |
| 37 | } |
| 38 | return lines_count; |
| 39 | } |
| 40 | |
| 41 | /* If patch_level is -1 it will remove all directory names |
| 42 | * char *line must be greater than 4 chars |
| 43 | * returns NULL if the file doesnt exist or error |
| 44 | * returns malloc'ed filename |
| 45 | * NB: frees 1st argument! |
| 46 | */ |
| 47 | static char *extract_filename(char *line, int patch_level, const char *pat) |
| 48 | { |
| 49 | char *temp = NULL, *filename_start_ptr = line + 4; |
| 50 | |
| 51 | if (strncmp(line, pat, 4) == 0) { |
| 52 | /* Terminate string at end of source filename */ |
| 53 | line[strcspn(line, "\t\n\r")] = '\0'; |
| 54 | |
| 55 | /* Skip over (patch_level) number of leading directories */ |
| 56 | while (patch_level--) { |
| 57 | temp = strchr(filename_start_ptr, '/'); |
| 58 | if (!temp) |
| 59 | break; |
| 60 | filename_start_ptr = temp + 1; |
| 61 | } |
| 62 | temp = xstrdup(filename_start_ptr); |
| 63 | } |
| 64 | free(line); |
| 65 | return temp; |
| 66 | } |
| 67 | |
| 68 | int patch_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE; |
| 69 | int patch_main(int argc UNUSED_PARAM, char **argv) |
| 70 | { |
| 71 | struct stat saved_stat; |
| 72 | char *patch_line; |
| 73 | FILE *patch_file; |
| 74 | int patch_level; |
| 75 | int ret = 0; |
| 76 | char plus = '+'; |
| 77 | unsigned opt; |
| 78 | enum { |
| 79 | OPT_R = (1 << 2), |
| 80 | OPT_N = (1 << 3), |
| 81 | /*OPT_f = (1 << 4), ignored */ |
| 82 | /*OPT_E = (1 << 5), ignored, this is the default */ |
| 83 | /*OPT_g = (1 << 6), ignored */ |
| 84 | OPT_dry_run = (1 << 7) * ENABLE_LONG_OPTS, |
| 85 | }; |
| 86 | |
| 87 | xfunc_error_retval = 2; |
| 88 | { |
| 89 | const char *p = "-1"; |
| 90 | const char *i = "-"; /* compat */ |
| 91 | #if ENABLE_LONG_OPTS |
| 92 | static const char patch_longopts[] ALIGN1 = |
| 93 | "strip\0" Required_argument "p" |
| 94 | "input\0" Required_argument "i" |
| 95 | "reverse\0" No_argument "R" |
| 96 | "forward\0" No_argument "N" |
| 97 | /* "Assume user knows what [s]he is doing, do not ask any questions": */ |
| 98 | "force\0" No_argument "f" /*ignored*/ |
| 99 | # if ENABLE_DESKTOP |
| 100 | "remove-empty-files\0" No_argument "E" /*ignored*/ |
| 101 | /* "Controls actions when a file is under RCS or SCCS control, |
| 102 | * and does not exist or is read-only and matches the default version, |
| 103 | * or when a file is under ClearCase control and does not exist..." |
| 104 | * IOW: rather obscure option. |
| 105 | * But Gentoo's portage does use -g0 */ |
| 106 | "get\0" Required_argument "g" /*ignored*/ |
| 107 | # endif |
| 108 | "dry-run\0" No_argument "\xfd" |
| 109 | # if ENABLE_DESKTOP |
| 110 | "backup-if-mismatch\0" No_argument "\xfe" /*ignored*/ |
| 111 | "no-backup-if-mismatch\0" No_argument "\xff" /*ignored*/ |
| 112 | # endif |
| 113 | ; |
| 114 | applet_long_options = patch_longopts; |
| 115 | #endif |
| 116 | /* -f,-E,-g are ignored */ |
| 117 | opt = getopt32(argv, "p:i:RN""fEg:", &p, &i, NULL); |
| 118 | if (opt & OPT_R) |
| 119 | plus = '-'; |
| 120 | patch_level = xatoi(p); /* can be negative! */ |
| 121 | patch_file = xfopen_stdin(i); |
| 122 | } |
| 123 | |
| 124 | patch_line = xmalloc_fgetline(patch_file); |
| 125 | while (patch_line) { |
| 126 | FILE *src_stream; |
| 127 | FILE *dst_stream; |
| 128 | //char *old_filename; |
| 129 | char *new_filename; |
| 130 | char *backup_filename = NULL; |
| 131 | unsigned src_cur_line = 1; |
| 132 | unsigned dst_cur_line = 0; |
| 133 | unsigned dst_beg_line; |
| 134 | unsigned bad_hunk_count = 0; |
| 135 | unsigned hunk_count = 0; |
| 136 | smallint copy_trailing_lines_flag = 0; |
| 137 | |
| 138 | /* Skip everything upto the "---" marker |
| 139 | * No need to parse the lines "Only in <dir>", and "diff <args>" |
| 140 | */ |
| 141 | do { |
| 142 | /* Extract the filename used before the patch was generated */ |
| 143 | new_filename = extract_filename(patch_line, patch_level, "--- "); |
| 144 | // was old_filename above |
| 145 | patch_line = xmalloc_fgetline(patch_file); |
| 146 | if (!patch_line) goto quit; |
| 147 | } while (!new_filename); |
| 148 | free(new_filename); // "source" filename is irrelevant |
| 149 | |
| 150 | new_filename = extract_filename(patch_line, patch_level, "+++ "); |
| 151 | if (!new_filename) { |
| 152 | bb_error_msg_and_die("invalid patch"); |
| 153 | } |
| 154 | |
| 155 | /* Get access rights from the file to be patched */ |
| 156 | if (stat(new_filename, &saved_stat) != 0) { |
| 157 | char *slash = strrchr(new_filename, '/'); |
| 158 | if (slash) { |
| 159 | /* Create leading directories */ |
| 160 | *slash = '\0'; |
| 161 | bb_make_directory(new_filename, -1, FILEUTILS_RECUR); |
| 162 | *slash = '/'; |
| 163 | } |
| 164 | src_stream = NULL; |
| 165 | saved_stat.st_mode = 0644; |
| 166 | } else if (!(opt & OPT_dry_run)) { |
| 167 | backup_filename = xasprintf("%s.orig", new_filename); |
| 168 | xrename(new_filename, backup_filename); |
| 169 | src_stream = xfopen_for_read(backup_filename); |
| 170 | } else |
| 171 | src_stream = xfopen_for_read(new_filename); |
| 172 | |
| 173 | if (opt & OPT_dry_run) { |
| 174 | dst_stream = xfopen_for_write("/dev/null"); |
| 175 | } else { |
| 176 | dst_stream = xfopen_for_write(new_filename); |
| 177 | fchmod(fileno(dst_stream), saved_stat.st_mode); |
| 178 | } |
| 179 | |
| 180 | printf("patching file %s\n", new_filename); |
| 181 | |
| 182 | /* Handle all hunks for this file */ |
| 183 | patch_line = xmalloc_fgets(patch_file); |
| 184 | while (patch_line) { |
| 185 | unsigned count; |
| 186 | unsigned src_beg_line; |
| 187 | unsigned hunk_offset_start; |
| 188 | unsigned src_last_line = 1; |
| 189 | unsigned dst_last_line = 1; |
| 190 | |
| 191 | if ((sscanf(patch_line, "@@ -%d,%d +%d,%d", &src_beg_line, &src_last_line, &dst_beg_line, &dst_last_line) < 3) |
| 192 | && (sscanf(patch_line, "@@ -%d +%d,%d", &src_beg_line, &dst_beg_line, &dst_last_line) < 2) |
| 193 | ) { |
| 194 | /* No more hunks for this file */ |
| 195 | break; |
| 196 | } |
| 197 | if (plus != '+') { |
| 198 | /* reverse patch */ |
| 199 | unsigned tmp = src_last_line; |
| 200 | src_last_line = dst_last_line; |
| 201 | dst_last_line = tmp; |
| 202 | tmp = src_beg_line; |
| 203 | src_beg_line = dst_beg_line; |
| 204 | dst_beg_line = tmp; |
| 205 | } |
| 206 | hunk_count++; |
| 207 | |
| 208 | if (src_beg_line && dst_beg_line) { |
| 209 | /* Copy unmodified lines upto start of hunk */ |
| 210 | /* src_beg_line will be 0 if it's a new file */ |
| 211 | count = src_beg_line - src_cur_line; |
| 212 | if (copy_lines(src_stream, dst_stream, count)) { |
| 213 | bb_error_msg_and_die("bad src file"); |
| 214 | } |
| 215 | src_cur_line += count; |
| 216 | dst_cur_line += count; |
| 217 | copy_trailing_lines_flag = 1; |
| 218 | } |
| 219 | src_last_line += hunk_offset_start = src_cur_line; |
| 220 | dst_last_line += dst_cur_line; |
| 221 | |
| 222 | while (1) { |
| 223 | free(patch_line); |
| 224 | patch_line = xmalloc_fgets(patch_file); |
| 225 | if (patch_line == NULL) |
| 226 | break; /* EOF */ |
| 227 | if (!*patch_line) { |
| 228 | /* whitespace-damaged patch with "" lines */ |
| 229 | free(patch_line); |
| 230 | patch_line = xstrdup(" "); |
| 231 | } |
| 232 | if ((*patch_line != '-') && (*patch_line != '+') |
| 233 | && (*patch_line != ' ') |
| 234 | ) { |
| 235 | break; /* End of hunk */ |
| 236 | } |
| 237 | if (*patch_line != plus) { /* '-' or ' ' */ |
| 238 | char *src_line = NULL; |
| 239 | if (src_cur_line == src_last_line) |
| 240 | break; |
| 241 | if (src_stream) { |
| 242 | src_line = xmalloc_fgets(src_stream); |
| 243 | if (src_line) { |
| 244 | int diff = strcmp(src_line, patch_line + 1); |
| 245 | src_cur_line++; |
| 246 | free(src_line); |
| 247 | if (diff) |
| 248 | src_line = NULL; |
| 249 | } |
| 250 | } |
| 251 | /* Do not patch an already patched hunk with -N */ |
| 252 | if (src_line == 0 && (opt & OPT_N)) { |
| 253 | continue; |
| 254 | } |
| 255 | if (!src_line) { |
| 256 | bb_error_msg("hunk #%u FAILED at %u", hunk_count, hunk_offset_start); |
| 257 | bad_hunk_count++; |
| 258 | break; |
| 259 | } |
| 260 | if (*patch_line != ' ') { /* '-' */ |
| 261 | continue; |
| 262 | } |
| 263 | } |
| 264 | if (dst_cur_line == dst_last_line) |
| 265 | break; |
| 266 | fputs(patch_line + 1, dst_stream); |
| 267 | dst_cur_line++; |
| 268 | } /* end of while loop handling one hunk */ |
| 269 | } /* end of while loop handling one file */ |
| 270 | |
| 271 | /* Cleanup last patched file */ |
| 272 | if (copy_trailing_lines_flag) { |
| 273 | copy_lines(src_stream, dst_stream, (unsigned)(-1)); |
| 274 | } |
| 275 | if (src_stream) { |
| 276 | fclose(src_stream); |
| 277 | } |
| 278 | fclose(dst_stream); |
| 279 | if (bad_hunk_count) { |
| 280 | ret = 1; |
| 281 | bb_error_msg("%u out of %u hunk FAILED", bad_hunk_count, hunk_count); |
| 282 | } else { |
| 283 | /* It worked, we can remove the backup */ |
| 284 | if (backup_filename) { |
| 285 | unlink(backup_filename); |
| 286 | } |
| 287 | if (!(opt & OPT_dry_run) |
| 288 | && ((dst_cur_line == 0) || (dst_beg_line == 0)) |
| 289 | ) { |
| 290 | /* The new patched file is empty, remove it */ |
| 291 | xunlink(new_filename); |
| 292 | // /* old_filename and new_filename may be the same file */ |
| 293 | // unlink(old_filename); |
| 294 | } |
| 295 | } |
| 296 | free(backup_filename); |
| 297 | //free(old_filename); |
| 298 | free(new_filename); |
| 299 | } /* end of "while there are patch lines" */ |
| 300 | quit: |
| 301 | /* 0 = SUCCESS |
| 302 | * 1 = Some hunks failed |
| 303 | * 2 = More serious problems (exited earlier) |
| 304 | */ |
| 305 | return ret; |
| 306 | } |