blob: 4cdc394d607a02ae12b6d6a5f08933378fc58716
1 | /* vi: set sw=4 ts=4: |
2 | * |
3 | * Apply a "universal" diff. |
4 | * Adapted from toybox's patch implementation. |
5 | * |
6 | * Copyright 2007 Rob Landley <rob@landley.net> |
7 | * |
8 | * see http://www.opengroup.org/onlinepubs/009695399/utilities/patch.html |
9 | * (But only does -u, because who still cares about "ed"?) |
10 | * |
11 | * TODO: |
12 | * -b backup |
13 | * -l treat all whitespace as a single space |
14 | * -d chdir first |
15 | * -D define wrap #ifdef and #ifndef around changes |
16 | * -o outfile output here instead of in place |
17 | * -r rejectfile write rejected hunks to this file |
18 | * --dry-run (regression!) |
19 | * |
20 | * -f force (no questions asked) |
21 | * -F fuzz (number, default 2) |
22 | * [file] which file to patch |
23 | */ |
24 | |
25 | //config:config PATCH |
26 | //config: bool "patch" |
27 | //config: default y |
28 | //config: help |
29 | //config: Apply a unified diff formatted patch. |
30 | |
31 | //applet:IF_PATCH(APPLET(patch, BB_DIR_USR_BIN, BB_SUID_DROP)) |
32 | |
33 | //kbuild:lib-$(CONFIG_PATCH) += patch.o |
34 | |
35 | //usage:#define patch_trivial_usage |
36 | //usage: "[OPTIONS] [ORIGFILE [PATCHFILE]]" |
37 | //usage:#define patch_full_usage "\n\n" |
38 | //usage: IF_LONG_OPTS( |
39 | //usage: " -p,--strip N Strip N leading components from file names" |
40 | //usage: "\n -i,--input DIFF Read DIFF instead of stdin" |
41 | //usage: "\n -R,--reverse Reverse patch" |
42 | //usage: "\n -N,--forward Ignore already applied patches" |
43 | /*usage: "\n --dry-run Don't actually change files" - TODO */ |
44 | //usage: "\n -E,--remove-empty-files Remove output files if they become empty" |
45 | //usage: ) |
46 | //usage: IF_NOT_LONG_OPTS( |
47 | //usage: " -p N Strip N leading components from file names" |
48 | //usage: "\n -i DIFF Read DIFF instead of stdin" |
49 | //usage: "\n -R Reverse patch" |
50 | //usage: "\n -N Ignore already applied patches" |
51 | //usage: "\n -E Remove output files if they become empty" |
52 | //usage: ) |
53 | /* -u "interpret as unified diff" is supported but not documented: this info is not useful for --help */ |
54 | /* -x "debug" is supported but does nothing */ |
55 | //usage: |
56 | //usage:#define patch_example_usage |
57 | //usage: "$ patch -p1 < example.diff\n" |
58 | //usage: "$ patch -p0 -i example.diff" |
59 | |
60 | #include "libbb.h" |
61 | |
62 | |
63 | // libbb candidate? |
64 | |
65 | struct double_list { |
66 | struct double_list *next; |
67 | struct double_list *prev; |
68 | char *data; |
69 | }; |
70 | |
71 | // Free all the elements of a linked list |
72 | // Call freeit() on each element before freeing it. |
73 | static void dlist_free(struct double_list *list, void (*freeit)(void *data)) |
74 | { |
75 | while (list) { |
76 | void *pop = list; |
77 | list = list->next; |
78 | freeit(pop); |
79 | // Bail out also if list is circular. |
80 | if (list == pop) break; |
81 | } |
82 | } |
83 | |
84 | // Add an entry before "list" element in (circular) doubly linked list |
85 | static struct double_list *dlist_add(struct double_list **list, char *data) |
86 | { |
87 | struct double_list *llist; |
88 | struct double_list *line = xmalloc(sizeof(*line)); |
89 | |
90 | line->data = data; |
91 | llist = *list; |
92 | if (llist) { |
93 | struct double_list *p; |
94 | line->next = llist; |
95 | p = line->prev = llist->prev; |
96 | // (list is circular, we assume p is never NULL) |
97 | p->next = line; |
98 | llist->prev = line; |
99 | } else |
100 | *list = line->next = line->prev = line; |
101 | |
102 | return line; |
103 | } |
104 | |
105 | |
106 | struct globals { |
107 | char *infile; |
108 | long prefix; |
109 | |
110 | struct double_list *current_hunk; |
111 | |
112 | long oldline, oldlen, newline, newlen; |
113 | long linenum; |
114 | int context, state, hunknum; |
115 | int filein, fileout; |
116 | char *tempname; |
117 | |
118 | int exitval; |
119 | }; |
120 | #define TT (*ptr_to_globals) |
121 | #define INIT_TT() do { \ |
122 | SET_PTR_TO_GLOBALS(xzalloc(sizeof(TT))); \ |
123 | } while (0) |
124 | |
125 | |
126 | #define FLAG_STR "Rup:i:NEx" |
127 | /* FLAG_REVERSE must be == 1! Code uses this fact. */ |
128 | #define FLAG_REVERSE (1 << 0) |
129 | #define FLAG_u (1 << 1) |
130 | #define FLAG_PATHLEN (1 << 2) |
131 | #define FLAG_INPUT (1 << 3) |
132 | #define FLAG_IGNORE (1 << 4) |
133 | #define FLAG_RMEMPTY (1 << 5) |
134 | /* Enable this bit and use -x for debug output: */ |
135 | #define FLAG_DEBUG (0 << 6) |
136 | |
137 | // Dispose of a line of input, either by writing it out or discarding it. |
138 | |
139 | // state < 2: just free |
140 | // state = 2: write whole line to stderr |
141 | // state = 3: write whole line to fileout |
142 | // state > 3: write line+1 to fileout when *line != state |
143 | |
144 | #define PATCH_DEBUG (option_mask32 & FLAG_DEBUG) |
145 | |
146 | static void do_line(void *data) |
147 | { |
148 | struct double_list *dlist = data; |
149 | |
150 | if (TT.state>1 && *dlist->data != TT.state) |
151 | fdprintf(TT.state == 2 ? 2 : TT.fileout, |
152 | "%s\n", dlist->data+(TT.state>3 ? 1 : 0)); |
153 | |
154 | if (PATCH_DEBUG) fdprintf(2, "DO %d: %s\n", TT.state, dlist->data); |
155 | |
156 | free(dlist->data); |
157 | free(dlist); |
158 | } |
159 | |
160 | static void finish_oldfile(void) |
161 | { |
162 | if (TT.tempname) { |
163 | // Copy the rest of the data and replace the original with the copy. |
164 | char *temp; |
165 | |
166 | if (TT.filein != -1) { |
167 | bb_copyfd_eof(TT.filein, TT.fileout); |
168 | xclose(TT.filein); |
169 | } |
170 | xclose(TT.fileout); |
171 | |
172 | temp = xstrdup(TT.tempname); |
173 | temp[strlen(temp) - 6] = '\0'; |
174 | rename(TT.tempname, temp); |
175 | free(temp); |
176 | |
177 | free(TT.tempname); |
178 | TT.tempname = NULL; |
179 | } |
180 | TT.fileout = TT.filein = -1; |
181 | } |
182 | |
183 | static void fail_hunk(void) |
184 | { |
185 | if (!TT.current_hunk) return; |
186 | |
187 | fdprintf(2, "Hunk %d FAILED %ld/%ld.\n", TT.hunknum, TT.oldline, TT.newline); |
188 | TT.exitval = 1; |
189 | |
190 | // If we got to this point, we've seeked to the end. Discard changes to |
191 | // this file and advance to next file. |
192 | |
193 | TT.state = 2; |
194 | TT.current_hunk->prev->next = NULL; |
195 | dlist_free(TT.current_hunk, do_line); |
196 | TT.current_hunk = NULL; |
197 | |
198 | // Abort the copy and delete the temporary file. |
199 | close(TT.filein); |
200 | close(TT.fileout); |
201 | unlink(TT.tempname); |
202 | free(TT.tempname); |
203 | TT.tempname = NULL; |
204 | |
205 | TT.state = 0; |
206 | } |
207 | |
208 | // Given a hunk of a unified diff, make the appropriate change to the file. |
209 | // This does not use the location information, but instead treats a hunk |
210 | // as a sort of regex. Copies data from input to output until it finds |
211 | // the change to be made, then outputs the changed data and returns. |
212 | // (Finding EOF first is an error.) This is a single pass operation, so |
213 | // multiple hunks must occur in order in the file. |
214 | |
215 | static int apply_one_hunk(void) |
216 | { |
217 | struct double_list *plist, *buf = NULL, *check; |
218 | int matcheof = 0, reverse = option_mask32 & FLAG_REVERSE, backwarn = 0; |
219 | /* Do we try "dummy" revert to check whether |
220 | * to silently skip this hunk? Used to implement -N. |
221 | */ |
222 | int dummy_revert = 0; |
223 | |
224 | // Break doubly linked list so we can use singly linked traversal function. |
225 | TT.current_hunk->prev->next = NULL; |
226 | |
227 | // Match EOF if there aren't as many ending context lines as beginning |
228 | for (plist = TT.current_hunk; plist; plist = plist->next) { |
229 | if (plist->data[0]==' ') matcheof++; |
230 | else matcheof = 0; |
231 | if (PATCH_DEBUG) fdprintf(2, "HUNK:%s\n", plist->data); |
232 | } |
233 | matcheof = !matcheof || matcheof < TT.context; |
234 | |
235 | if (PATCH_DEBUG) fdprintf(2,"MATCHEOF=%c\n", matcheof ? 'Y' : 'N'); |
236 | |
237 | // Loop through input data searching for this hunk. Match all context |
238 | // lines and all lines to be removed until we've found the end of a |
239 | // complete hunk. |
240 | plist = TT.current_hunk; |
241 | buf = NULL; |
242 | if (reverse ? TT.oldlen : TT.newlen) for (;;) { |
243 | char *data = xmalloc_reads(TT.filein, NULL); |
244 | |
245 | TT.linenum++; |
246 | |
247 | // Figure out which line of hunk to compare with next. (Skip lines |
248 | // of the hunk we'd be adding.) |
249 | while (plist && *plist->data == "+-"[reverse]) { |
250 | if (data && !strcmp(data, plist->data+1)) { |
251 | if (!backwarn) { |
252 | backwarn = TT.linenum; |
253 | if (option_mask32 & FLAG_IGNORE) { |
254 | dummy_revert = 1; |
255 | reverse ^= 1; |
256 | continue; |
257 | } |
258 | } |
259 | } |
260 | plist = plist->next; |
261 | } |
262 | |
263 | // Is this EOF? |
264 | if (!data) { |
265 | if (PATCH_DEBUG) fdprintf(2, "INEOF\n"); |
266 | |
267 | // Does this hunk need to match EOF? |
268 | if (!plist && matcheof) break; |
269 | |
270 | if (backwarn) |
271 | fdprintf(2,"Possibly reversed hunk %d at %ld\n", |
272 | TT.hunknum, TT.linenum); |
273 | |
274 | // File ended before we found a place for this hunk. |
275 | fail_hunk(); |
276 | goto done; |
277 | } |
278 | |
279 | if (PATCH_DEBUG) fdprintf(2, "IN: %s\n", data); |
280 | check = dlist_add(&buf, data); |
281 | |
282 | // Compare this line with next expected line of hunk. |
283 | // todo: teach the strcmp() to ignore whitespace. |
284 | |
285 | // A match can fail because the next line doesn't match, or because |
286 | // we hit the end of a hunk that needed EOF, and this isn't EOF. |
287 | |
288 | // If match failed, flush first line of buffered data and |
289 | // recheck buffered data for a new match until we find one or run |
290 | // out of buffer. |
291 | |
292 | for (;;) { |
293 | if (!plist || strcmp(check->data, plist->data+1)) { |
294 | // Match failed. Write out first line of buffered data and |
295 | // recheck remaining buffered data for a new match. |
296 | |
297 | if (PATCH_DEBUG) |
298 | fdprintf(2, "NOT: %s\n", plist->data); |
299 | |
300 | TT.state = 3; |
301 | check = buf; |
302 | buf = buf->next; |
303 | check->prev->next = buf; |
304 | buf->prev = check->prev; |
305 | do_line(check); |
306 | plist = TT.current_hunk; |
307 | |
308 | // If we've reached the end of the buffer without confirming a |
309 | // match, read more lines. |
310 | if (check == buf) { |
311 | buf = NULL; |
312 | break; |
313 | } |
314 | check = buf; |
315 | } else { |
316 | if (PATCH_DEBUG) |
317 | fdprintf(2, "MAYBE: %s\n", plist->data); |
318 | // This line matches. Advance plist, detect successful match. |
319 | plist = plist->next; |
320 | if (!plist && !matcheof) goto out; |
321 | check = check->next; |
322 | if (check == buf) break; |
323 | } |
324 | } |
325 | } |
326 | out: |
327 | // We have a match. Emit changed data. |
328 | TT.state = "-+"[reverse ^ dummy_revert]; |
329 | dlist_free(TT.current_hunk, do_line); |
330 | TT.current_hunk = NULL; |
331 | TT.state = 1; |
332 | done: |
333 | if (buf) { |
334 | buf->prev->next = NULL; |
335 | dlist_free(buf, do_line); |
336 | } |
337 | |
338 | return TT.state; |
339 | } |
340 | |
341 | // Read a patch file and find hunks, opening/creating/deleting files. |
342 | // Call apply_one_hunk() on each hunk. |
343 | |
344 | // state 0: Not in a hunk, look for +++. |
345 | // state 1: Found +++ file indicator, look for @@ |
346 | // state 2: In hunk: counting initial context lines |
347 | // state 3: In hunk: getting body |
348 | |
349 | int patch_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE; |
350 | int patch_main(int argc UNUSED_PARAM, char **argv) |
351 | { |
352 | int opts; |
353 | int reverse, state = 0; |
354 | char *oldname = NULL, *newname = NULL; |
355 | char *opt_p, *opt_i; |
356 | long oldlen = 0; |
357 | long newlen = 0; |
358 | |
359 | INIT_TT(); |
360 | |
361 | opts = getopt32(argv, FLAG_STR, &opt_p, &opt_i); |
362 | argv += optind; |
363 | reverse = opts & FLAG_REVERSE; |
364 | TT.prefix = (opts & FLAG_PATHLEN) ? xatoi(opt_p) : 0; // can be negative! |
365 | TT.filein = TT.fileout = -1; |
366 | if (opts & FLAG_INPUT) { |
367 | xmove_fd(xopen_stdin(opt_i), STDIN_FILENO); |
368 | } else { |
369 | if (argv[0] && argv[1]) { |
370 | xmove_fd(xopen_stdin(argv[1]), STDIN_FILENO); |
371 | } |
372 | } |
373 | if (argv[0]) { |
374 | oldname = xstrdup(argv[0]); |
375 | newname = xstrdup(argv[0]); |
376 | } |
377 | |
378 | // Loop through the lines in the patch |
379 | for(;;) { |
380 | char *patchline; |
381 | |
382 | patchline = xmalloc_fgetline(stdin); |
383 | if (!patchline) break; |
384 | |
385 | // Other versions of patch accept damaged patches, |
386 | // so we need to also. |
387 | if (!*patchline) { |
388 | free(patchline); |
389 | patchline = xstrdup(" "); |
390 | } |
391 | |
392 | // Are we assembling a hunk? |
393 | if (state >= 2) { |
394 | if (*patchline==' ' || *patchline=='+' || *patchline=='-') { |
395 | dlist_add(&TT.current_hunk, patchline); |
396 | |
397 | if (*patchline != '+') oldlen--; |
398 | if (*patchline != '-') newlen--; |
399 | |
400 | // Context line? |
401 | if (*patchline==' ' && state==2) TT.context++; |
402 | else state=3; |
403 | |
404 | // If we've consumed all expected hunk lines, apply the hunk. |
405 | |
406 | if (!oldlen && !newlen) state = apply_one_hunk(); |
407 | continue; |
408 | } |
409 | fail_hunk(); |
410 | state = 0; |
411 | continue; |
412 | } |
413 | |
414 | // Open a new file? |
415 | if (!strncmp("--- ", patchline, 4) || !strncmp("+++ ", patchline, 4)) { |
416 | char *s, **name = reverse ? &newname : &oldname; |
417 | int i; |
418 | |
419 | if (*patchline == '+') { |
420 | name = reverse ? &oldname : &newname; |
421 | state = 1; |
422 | } |
423 | |
424 | finish_oldfile(); |
425 | |
426 | if (!argv[0]) { |
427 | free(*name); |
428 | // Trim date from end of filename (if any). We don't care. |
429 | for (s = patchline+4; *s && *s!='\t'; s++) |
430 | if (*s=='\\' && s[1]) s++; |
431 | i = atoi(s); |
432 | if (i>1900 && i<=1970) |
433 | *name = xstrdup("/dev/null"); |
434 | else { |
435 | *s = 0; |
436 | *name = xstrdup(patchline+4); |
437 | } |
438 | } |
439 | |
440 | // We defer actually opening the file because svn produces broken |
441 | // patches that don't signal they want to create a new file the |
442 | // way the patch man page says, so you have to read the first hunk |
443 | // and _guess_. |
444 | |
445 | // Start a new hunk? Usually @@ -oldline,oldlen +newline,newlen @@ |
446 | // but a missing ,value means the value is 1. |
447 | } else if (state == 1 && !strncmp("@@ -", patchline, 4)) { |
448 | int i; |
449 | char *s = patchline+4; |
450 | |
451 | // Read oldline[,oldlen] +newline[,newlen] |
452 | |
453 | TT.oldlen = oldlen = TT.newlen = newlen = 1; |
454 | TT.oldline = strtol(s, &s, 10); |
455 | if (*s == ',') TT.oldlen = oldlen = strtol(s+1, &s, 10); |
456 | TT.newline = strtol(s+2, &s, 10); |
457 | if (*s == ',') TT.newlen = newlen = strtol(s+1, &s, 10); |
458 | |
459 | if (oldlen < 1 && newlen < 1) |
460 | bb_error_msg_and_die("Really? %s", patchline); |
461 | |
462 | TT.context = 0; |
463 | state = 2; |
464 | |
465 | // If this is the first hunk, open the file. |
466 | if (TT.filein == -1) { |
467 | int oldsum, newsum, empty = 0; |
468 | char *name; |
469 | |
470 | oldsum = TT.oldline + oldlen; |
471 | newsum = TT.newline + newlen; |
472 | |
473 | name = reverse ? oldname : newname; |
474 | |
475 | // We're deleting oldname if new file is /dev/null (before -p) |
476 | // or if new hunk is empty (zero context) after patching |
477 | if (!strcmp(name, "/dev/null") || !(reverse ? oldsum : newsum)) { |
478 | name = reverse ? newname : oldname; |
479 | empty++; |
480 | } |
481 | |
482 | // handle -p path truncation. |
483 | for (i = 0, s = name; *s;) { |
484 | if ((option_mask32 & FLAG_PATHLEN) && TT.prefix == i) |
485 | break; |
486 | if (*s++ != '/') |
487 | continue; |
488 | while (*s == '/') |
489 | s++; |
490 | i++; |
491 | name = s; |
492 | } |
493 | |
494 | if (empty) { |
495 | // File is empty after the patches have been applied |
496 | state = 0; |
497 | if (option_mask32 & FLAG_RMEMPTY) { |
498 | // If flag -E or --remove-empty-files is set |
499 | printf("removing %s\n", name); |
500 | xunlink(name); |
501 | } else { |
502 | printf("patching file %s\n", name); |
503 | xclose(xopen(name, O_WRONLY | O_TRUNC)); |
504 | } |
505 | // If we've got a file to open, do so. |
506 | } else if (!(option_mask32 & FLAG_PATHLEN) || i <= TT.prefix) { |
507 | struct stat statbuf; |
508 | |
509 | // If the old file was null, we're creating a new one. |
510 | if (!strcmp(oldname, "/dev/null") || !oldsum) { |
511 | printf("creating %s\n", name); |
512 | s = strrchr(name, '/'); |
513 | if (s) { |
514 | *s = 0; |
515 | bb_make_directory(name, -1, FILEUTILS_RECUR); |
516 | *s = '/'; |
517 | } |
518 | TT.filein = xopen(name, O_CREAT|O_EXCL|O_RDWR); |
519 | } else { |
520 | printf("patching file %s\n", name); |
521 | TT.filein = xopen(name, O_RDONLY); |
522 | } |
523 | |
524 | TT.tempname = xasprintf("%sXXXXXX", name); |
525 | TT.fileout = xmkstemp(TT.tempname); |
526 | // Set permissions of output file |
527 | fstat(TT.filein, &statbuf); |
528 | fchmod(TT.fileout, statbuf.st_mode); |
529 | |
530 | TT.linenum = 0; |
531 | TT.hunknum = 0; |
532 | } |
533 | } |
534 | |
535 | TT.hunknum++; |
536 | |
537 | continue; |
538 | } |
539 | |
540 | // If we didn't continue above, discard this line. |
541 | free(patchline); |
542 | } |
543 | |
544 | finish_oldfile(); |
545 | |
546 | if (ENABLE_FEATURE_CLEAN_UP) { |
547 | free(oldname); |
548 | free(newname); |
549 | } |
550 | |
551 | return TT.exitval; |
552 | } |
553 |