1 /* patch.c - Apply a "universal" diff. 2 * 3 * Copyright 2007 Rob Landley <rob (at) landley.net> 4 * 5 * see http://opengroup.org/onlinepubs/9699919799/utilities/patch.html 6 * (But only does -u, because who still cares about "ed"?) 7 * 8 * TODO: 9 * -b backup 10 * -N ignore already applied 11 * -d chdir first 12 * -D define wrap #ifdef and #ifndef around changes 13 * -o outfile output here instead of in place 14 * -r rejectfile write rejected hunks to this file 15 * 16 * -E remove empty files --remove-empty-files 17 * -f force (no questions asked) 18 * -F fuzz (number, default 2) 19 * [file] which file to patch 20 21 USE_PATCH(NEWTOY(patch, "(dry-run)"USE_TOYBOX_DEBUG("x")"ulp#d:i:Rs(quiet)", TOYFLAG_USR|TOYFLAG_BIN)) 22 23 config PATCH 24 bool "patch" 25 default y 26 help 27 usage: patch [-d DIR] [-i file] [-p depth] [-Rlsu] [--dry-run] 28 29 Apply a unified diff to one or more files. 30 31 -d Modify files in DIR 32 -i Input file (default=stdin) 33 -l Loose match (ignore whitespace) 34 -p Number of '/' to strip from start of file paths (default=all) 35 -R Reverse patch 36 -s Silent except for errors 37 -u Ignored (only handles "unified" diffs) 38 --dry-run Don't change files, just confirm patch applies 39 40 This version of patch only handles unified diffs, and only modifies 41 a file when all hunks to that file apply. Patch prints failed hunks 42 to stderr, and exits with nonzero status if any hunks fail. 43 44 A file compared against /dev/null (or with a date <= the epoch) is 45 created/deleted as appropriate. 46 */ 47 48 #define FOR_patch 49 #include "toys.h" 50 51 GLOBALS( 52 char *i, *d; 53 long p; 54 55 struct double_list *current_hunk; 56 long oldline, oldlen, newline, newlen; 57 long linenum; 58 int context, state, filein, fileout, filepatch, hunknum; 59 char *tempname; 60 ) 61 62 // Dispose of a line of input, either by writing it out or discarding it. 63 64 // state < 2: just free 65 // state = 2: write whole line to stderr 66 // state = 3: write whole line to fileout 67 // state > 3: write line+1 to fileout when *line != state 68 69 static void do_line(void *data) 70 { 71 struct double_list *dlist = (struct double_list *)data; 72 73 if (TT.state>1 && *dlist->data != TT.state) { 74 char *s = dlist->data+(TT.state>3); 75 int i = TT.state == 2 ? 2 : TT.fileout; 76 77 xwrite(i, s, strlen(s)); 78 xwrite(i, "\n", 1); 79 } 80 81 if (FLAG(x)) fprintf(stderr, "DO %d: %s\n", TT.state, dlist->data); 82 83 free(dlist->data); 84 free(data); 85 } 86 87 static void finish_oldfile(void) 88 { 89 if (TT.tempname) replace_tempfile(TT.filein, TT.fileout, &TT.tempname); 90 TT.fileout = TT.filein = -1; 91 } 92 93 static void fail_hunk(void) 94 { 95 if (!TT.current_hunk) return; 96 97 fprintf(stderr, "Hunk %d FAILED %ld/%ld.\n", 98 TT.hunknum, TT.oldline, TT.newline); 99 toys.exitval = 1; 100 101 // If we got to this point, we've seeked to the end. Discard changes to 102 // this file and advance to next file. 103 104 TT.state = 2; 105 llist_traverse(TT.current_hunk, do_line); 106 TT.current_hunk = NULL; 107 if (!FLAG(dry_run)) delete_tempfile(TT.filein, TT.fileout, &TT.tempname); 108 TT.state = 0; 109 } 110 111 // Compare ignoring whitespace. Just returns 0/1, no > or < 112 static int loosecmp(char *aa, char *bb) 113 { 114 int a = 0, b = 0; 115 116 for (;;) { 117 while (isspace(aa[a])) a++; 118 while (isspace(bb[b])) b++; 119 if (aa[a] != bb[b]) return 1; 120 if (!aa[a]) return 0; 121 a++, b++; 122 } 123 } 124 125 // Given a hunk of a unified diff, make the appropriate change to the file. 126 // This does not use the location information, but instead treats a hunk 127 // as a sort of regex. Copies data from input to output until it finds 128 // the change to be made, then outputs the changed data and returns. 129 // (Finding EOF first is an error.) This is a single pass operation, so 130 // multiple hunks must occur in order in the file. 131 132 static int apply_one_hunk(void) 133 { 134 struct double_list *plist, *buf = NULL, *check; 135 int matcheof, trailing = 0, reverse = FLAG(R), backwarn = 0; 136 int (*lcmp)(char *aa, char *bb); 137 138 lcmp = FLAG(l) ? (void *)loosecmp : (void *)strcmp; 139 dlist_terminate(TT.current_hunk); 140 141 // Match EOF if there aren't as many ending context lines as beginning 142 for (plist = TT.current_hunk; plist; plist = plist->next) { 143 if (plist->data[0]==' ') trailing++; 144 else trailing = 0; 145 if (FLAG(x)) fprintf(stderr, "HUNK:%s\n", plist->data); 146 } 147 matcheof = !trailing || trailing < TT.context; 148 149 if (FLAG(x)) fprintf(stderr,"MATCHEOF=%c\n", matcheof ? 'Y' : 'N'); 150 151 // Loop through input data searching for this hunk. Match all context 152 // lines and all lines to be removed until we've found the end of a 153 // complete hunk. 154 plist = TT.current_hunk; 155 buf = NULL; 156 157 for (;;) { 158 char *data = get_line(TT.filein); 159 160 TT.linenum++; 161 // Figure out which line of hunk to compare with next. (Skip lines 162 // of the hunk we'd be adding.) 163 while (plist && *plist->data == "+-"[reverse]) { 164 if (data && !lcmp(data, plist->data+1)) 165 if (!backwarn) backwarn = TT.linenum; 166 plist = plist->next; 167 } 168 169 // Is this EOF? 170 if (!data) { 171 if (FLAG(x)) fprintf(stderr, "INEOF\n"); 172 173 // Does this hunk need to match EOF? 174 if (!plist && matcheof) break; 175 176 if (backwarn && !FLAG(s)) 177 fprintf(stderr, "Possibly reversed hunk %d at %ld\n", 178 TT.hunknum, TT.linenum); 179 180 // File ended before we found a place for this hunk. 181 fail_hunk(); 182 goto done; 183 } else if (FLAG(x)) fprintf(stderr, "IN: %s\n", data); 184 check = dlist_add(&buf, data); 185 186 // Compare this line with next expected line of hunk. 187 188 // A match can fail because the next line doesn't match, or because 189 // we hit the end of a hunk that needed EOF, and this isn't EOF. 190 191 // If match failed, flush first line of buffered data and 192 // recheck buffered data for a new match until we find one or run 193 // out of buffer. 194 195 for (;;) { 196 if (!plist || lcmp(check->data, plist->data+1)) { 197 // Match failed. Write out first line of buffered data and 198 // recheck remaining buffered data for a new match. 199 200 if (FLAG(x)) { 201 int bug = 0; 202 203 if (!plist) fprintf(stderr, "NULL plist\n"); 204 else { 205 while (plist->data[bug] == check->data[bug]) bug++; 206 fprintf(stderr, "NOT(%d:%d!=%d): %s\n", bug, plist->data[bug], 207 check->data[bug], plist->data); 208 } 209 } 210 211 // If this hunk must match start of file, fail if it didn't. 212 if (!TT.context || trailing>TT.context) { 213 fail_hunk(); 214 goto done; 215 } 216 217 TT.state = 3; 218 do_line(check = dlist_pop(&buf)); 219 plist = TT.current_hunk; 220 221 // If we've reached the end of the buffer without confirming a 222 // match, read more lines. 223 if (!buf) break; 224 check = buf; 225 } else { 226 if (FLAG(x)) fprintf(stderr, "MAYBE: %s\n", plist->data); 227 // This line matches. Advance plist, detect successful match. 228 plist = plist->next; 229 if (!plist && !matcheof) goto out; 230 check = check->next; 231 if (check == buf) break; 232 } 233 } 234 } 235 out: 236 // We have a match. Emit changed data. 237 TT.state = "-+"[reverse]; 238 llist_traverse(TT.current_hunk, do_line); 239 TT.current_hunk = NULL; 240 TT.state = 1; 241 done: 242 if (buf) { 243 dlist_terminate(buf); 244 llist_traverse(buf, do_line); 245 } 246 247 return TT.state; 248 } 249 250 // Read a patch file and find hunks, opening/creating/deleting files. 251 // Call apply_one_hunk() on each hunk. 252 253 // state 0: Not in a hunk, look for +++. 254 // state 1: Found +++ file indicator, look for @@ 255 // state 2: In hunk: counting initial context lines 256 // state 3: In hunk: getting body 257 258 void patch_main(void) 259 { 260 int reverse = FLAG(R), state = 0, patchlinenum = 0, strip = 0; 261 char *oldname = NULL, *newname = NULL; 262 263 if (TT.i) TT.filepatch = xopenro(TT.i); 264 TT.filein = TT.fileout = -1; 265 266 if (TT.d) xchdir(TT.d); 267 268 // Loop through the lines in the patch 269 for (;;) { 270 char *patchline; 271 272 patchline = get_line(TT.filepatch); 273 if (!patchline) break; 274 275 // Other versions of patch accept damaged patches, so we need to also. 276 if (strip || !patchlinenum++) { 277 int len = strlen(patchline); 278 if (patchline[len-1] == '\r') { 279 if (!strip && !FLAG(s)) fprintf(stderr, "Removing DOS newlines\n"); 280 strip = 1; 281 patchline[len-1]=0; 282 } 283 } 284 if (!*patchline) { 285 free(patchline); 286 patchline = xstrdup(" "); 287 } 288 289 // Are we assembling a hunk? 290 if (state >= 2) { 291 if (*patchline==' ' || *patchline=='+' || *patchline=='-') { 292 dlist_add(&TT.current_hunk, patchline); 293 294 if (*patchline != '+') TT.oldlen--; 295 if (*patchline != '-') TT.newlen--; 296 297 // Context line? 298 if (*patchline==' ' && state==2) TT.context++; 299 else state=3; 300 301 // If we've consumed all expected hunk lines, apply the hunk. 302 if (!TT.oldlen && !TT.newlen) state = apply_one_hunk(); 303 continue; 304 } 305 dlist_terminate(TT.current_hunk); 306 fail_hunk(); 307 state = 0; 308 continue; 309 } 310 311 // Open a new file? 312 if (!strncmp("--- ", patchline, 4) || !strncmp("+++ ", patchline, 4)) { 313 char *s, **name = &oldname; 314 int i; 315 316 if (*patchline == '+') { 317 name = &newname; 318 state = 1; 319 } 320 321 free(*name); 322 finish_oldfile(); 323 324 // Trim date from end of filename (if any). We don't care. 325 for (s = patchline+4; *s && (*s!='\t' || !isdigit(s[1])); s++) 326 if (*s=='\\' && s[1]) s++; 327 i = atoi(s); 328 if (i>1900 && i<=1970) *name = xstrdup("/dev/null"); 329 else { 330 *s = 0; 331 *name = xstrdup(patchline+4); 332 } 333 334 // We defer actually opening the file because svn produces broken 335 // patches that don't signal they want to create a new file the 336 // way the patch man page says, so you have to read the first hunk 337 // and _guess_. 338 339 // Start a new hunk? Usually @@ -oldline,oldlen +newline,newlen @@ 340 // but a missing ,value means the value is 1. 341 } else if (state == 1 && !strncmp("@@ -", patchline, 4)) { 342 int i; 343 char *s = patchline+4; 344 345 // Read oldline[,oldlen] +newline[,newlen] 346 347 TT.oldlen = TT.newlen = 1; 348 TT.oldline = strtol(s, &s, 10); 349 if (*s == ',') TT.oldlen=strtol(s+1, &s, 10); 350 TT.newline = strtol(s+2, &s, 10); 351 if (*s == ',') TT.newlen = strtol(s+1, &s, 10); 352 353 TT.context = 0; 354 state = 2; 355 356 // If this is the first hunk, open the file. 357 if (TT.filein == -1) { 358 int oldsum, newsum, del = 0; 359 char *name; 360 361 oldsum = TT.oldline + TT.oldlen; 362 newsum = TT.newline + TT.newlen; 363 364 name = reverse ? oldname : newname; 365 366 // We're deleting oldname if new file is /dev/null (before -p) 367 // or if new hunk is empty (zero context) after patching 368 if (!strcmp(name, "/dev/null") || !(reverse ? oldsum : newsum)) 369 { 370 name = reverse ? newname : oldname; 371 del++; 372 } 373 374 // handle -p path truncation. 375 for (i = 0, s = name; *s;) { 376 if (FLAG(p) && TT.p == i) break; 377 if (*s++ != '/') continue; 378 while (*s == '/') s++; 379 name = s; 380 i++; 381 } 382 383 if (del) { 384 if (!FLAG(s)) printf("removing %s\n", name); 385 xunlink(name); 386 state = 0; 387 // If we've got a file to open, do so. 388 } else if (!FLAG(p) || i <= TT.p) { 389 // If the old file was null, we're creating a new one. 390 if ((!strcmp(oldname, "/dev/null") || !oldsum) && access(name, F_OK)) 391 { 392 if (!FLAG(s)) printf("creating %s\n", name); 393 if (mkpath(name)) perror_exit("mkpath %s", name); 394 TT.filein = xcreate(name, O_CREAT|O_EXCL|O_RDWR, 0666); 395 } else { 396 if (!FLAG(s)) printf("patching %s\n", name); 397 TT.filein = xopenro(name); 398 } 399 if (FLAG(dry_run)) TT.fileout = xopen("/dev/null", O_RDWR); 400 else TT.fileout = copy_tempfile(TT.filein, name, &TT.tempname); 401 TT.linenum = 0; 402 TT.hunknum = 0; 403 } 404 } 405 406 TT.hunknum++; 407 408 continue; 409 } 410 411 // If we didn't continue above, discard this line. 412 free(patchline); 413 } 414 415 finish_oldfile(); 416 417 if (CFG_TOYBOX_FREE) { 418 close(TT.filepatch); 419 free(oldname); 420 free(newname); 421 } 422 } 423