blob: 5174acd6a9315f23e886d607eb5d6f3df916c884
1 | /* Adapted from toybox's patch. */ |
2 | |
3 | /* vi: set sw=4 ts=4: |
4 | * |
5 | * patch.c - Apply a "universal" diff. |
6 | * |
7 | * Copyright 2007 Rob Landley <rob@landley.net> |
8 | * |
9 | * see http://www.opengroup.org/onlinepubs/009695399/utilities/patch.html |
10 | * (But only does -u, because who still cares about "ed"?) |
11 | * |
12 | * TODO: |
13 | * -b backup |
14 | * -l treat all whitespace as a single space |
15 | * -N ignore already applied |
16 | * -d chdir first |
17 | * -D define wrap #ifdef and #ifndef around changes |
18 | * -o outfile output here instead of in place |
19 | * -r rejectfile write rejected hunks to this file |
20 | * |
21 | * -E remove empty files --remove-empty-files |
22 | * -f force (no questions asked) |
23 | * -F fuzz (number, default 2) |
24 | * [file] which file to patch |
25 | |
26 | USE_PATCH(NEWTOY(patch, USE_TOYBOX_DEBUG("x")"up#i:R", TOYFLAG_USR|TOYFLAG_BIN)) |
27 | |
28 | config PATCH |
29 | bool "patch" |
30 | default y |
31 | help |
32 | usage: patch [-i file] [-p depth] [-Ru] |
33 | |
34 | Apply a unified diff to one or more files. |
35 | |
36 | -i Input file (defaults=stdin) |
37 | -p number of '/' to strip from start of file paths (default=all) |
38 | -R Reverse patch. |
39 | -u Ignored (only handles "unified" diffs) |
40 | |
41 | This version of patch only handles unified diffs, and only modifies |
42 | a file when all all hunks to that file apply. Patch prints failed |
43 | hunks to stderr, and exits with nonzero status if any hunks fail. |
44 | |
45 | A file compared against /dev/null (or with a date <= the epoch) is |
46 | created/deleted as appropriate. |
47 | */ |
48 | #include "libbb.h" |
49 | |
50 | struct double_list { |
51 | struct double_list *next; |
52 | struct double_list *prev; |
53 | char *data; |
54 | }; |
55 | |
56 | // Return the first item from the list, advancing the list (which must be called |
57 | // as &list) |
58 | static |
59 | void *TOY_llist_pop(void *list) |
60 | { |
61 | // I'd use a void ** for the argument, and even accept the typecast in all |
62 | // callers as documentation you need the &, except the stupid compiler |
63 | // would then scream about type-punned pointers. Screw it. |
64 | void **llist = (void **)list; |
65 | void **next = (void **)*llist; |
66 | *llist = *next; |
67 | |
68 | return (void *)next; |
69 | } |
70 | |
71 | // Free all the elements of a linked list |
72 | // if freeit!=NULL call freeit() on each element before freeing it. |
73 | static |
74 | void TOY_llist_free(void *list, void (*freeit)(void *data)) |
75 | { |
76 | while (list) { |
77 | void *pop = TOY_llist_pop(&list); |
78 | if (freeit) freeit(pop); |
79 | else free(pop); |
80 | |
81 | // End doubly linked list too. |
82 | if (list==pop) break; |
83 | } |
84 | } |
85 | |
86 | // Add an entry to the end off a doubly linked list |
87 | static |
88 | struct double_list *dlist_add(struct double_list **list, char *data) |
89 | { |
90 | struct double_list *line = xmalloc(sizeof(struct double_list)); |
91 | |
92 | line->data = data; |
93 | if (*list) { |
94 | line->next = *list; |
95 | line->prev = (*list)->prev; |
96 | (*list)->prev->next = line; |
97 | (*list)->prev = line; |
98 | } else *list = line->next = line->prev = line; |
99 | |
100 | return line; |
101 | } |
102 | |
103 | // Ensure entire path exists. |
104 | // If mode != -1 set permissions on newly created dirs. |
105 | // Requires that path string be writable (for temporary null terminators). |
106 | static |
107 | void xmkpath(char *path, int mode) |
108 | { |
109 | char *p, old; |
110 | mode_t mask; |
111 | int rc; |
112 | struct stat st; |
113 | |
114 | for (p = path; ; p++) { |
115 | if (!*p || *p == '/') { |
116 | old = *p; |
117 | *p = rc = 0; |
118 | if (stat(path, &st) || !S_ISDIR(st.st_mode)) { |
119 | if (mode != -1) { |
120 | mask = umask(0); |
121 | rc = mkdir(path, mode); |
122 | umask(mask); |
123 | } else rc = mkdir(path, 0777); |
124 | } |
125 | *p = old; |
126 | if(rc) bb_perror_msg_and_die("mkpath '%s'", path); |
127 | } |
128 | if (!*p) break; |
129 | } |
130 | } |
131 | |
132 | // Slow, but small. |
133 | static |
134 | char *get_rawline(int fd, long *plen, char end) |
135 | { |
136 | char c, *buf = NULL; |
137 | long len = 0; |
138 | |
139 | for (;;) { |
140 | if (1>read(fd, &c, 1)) break; |
141 | if (!(len & 63)) buf=xrealloc(buf, len+65); |
142 | if ((buf[len++]=c) == end) break; |
143 | } |
144 | if (buf) buf[len]=0; |
145 | if (plen) *plen = len; |
146 | |
147 | return buf; |
148 | } |
149 | |
150 | static |
151 | char *get_line(int fd) |
152 | { |
153 | long len; |
154 | char *buf = get_rawline(fd, &len, '\n'); |
155 | |
156 | if (buf && buf[--len]=='\n') buf[len]=0; |
157 | |
158 | return buf; |
159 | } |
160 | |
161 | // Copy the rest of in to out and close both files. |
162 | static |
163 | void xsendfile(int in, int out) |
164 | { |
165 | long len; |
166 | char buf[4096]; |
167 | |
168 | if (in<0) return; |
169 | for (;;) { |
170 | len = safe_read(in, buf, 4096); |
171 | if (len<1) break; |
172 | xwrite(out, buf, len); |
173 | } |
174 | } |
175 | |
176 | // Copy the rest of the data and replace the original with the copy. |
177 | static |
178 | void replace_tempfile(int fdin, int fdout, char **tempname) |
179 | { |
180 | char *temp = xstrdup(*tempname); |
181 | |
182 | temp[strlen(temp)-6]=0; |
183 | if (fdin != -1) { |
184 | xsendfile(fdin, fdout); |
185 | xclose(fdin); |
186 | } |
187 | xclose(fdout); |
188 | rename(*tempname, temp); |
189 | free(*tempname); |
190 | free(temp); |
191 | *tempname = NULL; |
192 | } |
193 | |
194 | // Open a temporary file to copy an existing file into. |
195 | static |
196 | int copy_tempfile(int fdin, char *name, char **tempname) |
197 | { |
198 | struct stat statbuf; |
199 | int fd; |
200 | |
201 | *tempname = xasprintf("%sXXXXXX", name); |
202 | fd = mkstemp(*tempname); |
203 | if(-1 == fd) bb_perror_msg_and_die("no temp file"); |
204 | |
205 | // Set permissions of output file |
206 | fstat(fdin, &statbuf); |
207 | fchmod(fd, statbuf.st_mode); |
208 | |
209 | return fd; |
210 | } |
211 | |
212 | // Abort the copy and delete the temporary file. |
213 | static |
214 | void delete_tempfile(int fdin, int fdout, char **tempname) |
215 | { |
216 | close(fdin); |
217 | close(fdout); |
218 | unlink(*tempname); |
219 | free(*tempname); |
220 | *tempname = NULL; |
221 | } |
222 | |
223 | |
224 | |
225 | struct globals { |
226 | char *infile; |
227 | long prefix; |
228 | |
229 | struct double_list *current_hunk; |
230 | long oldline, oldlen, newline, newlen, linenum; |
231 | int context, state, filein, fileout, filepatch, hunknum; |
232 | char *tempname; |
233 | |
234 | // was toys.foo: |
235 | int exitval; |
236 | }; |
237 | #define TT (*ptr_to_globals) |
238 | #define INIT_TT() do { \ |
239 | SET_PTR_TO_GLOBALS(xzalloc(sizeof(TT))); \ |
240 | } while (0) |
241 | |
242 | |
243 | //bbox had: "p:i:RN" |
244 | #define FLAG_STR "Rup:i:x" |
245 | /* FLAG_REVERSE must be == 1! Code uses this fact. */ |
246 | #define FLAG_REVERSE (1 << 0) |
247 | #define FLAG_u (1 << 1) |
248 | #define FLAG_PATHLEN (1 << 2) |
249 | #define FLAG_INPUT (1 << 3) |
250 | //non-standard: |
251 | #define FLAG_DEBUG (1 << 4) |
252 | |
253 | // Dispose of a line of input, either by writing it out or discarding it. |
254 | |
255 | // state < 2: just free |
256 | // state = 2: write whole line to stderr |
257 | // state = 3: write whole line to fileout |
258 | // state > 3: write line+1 to fileout when *line != state |
259 | |
260 | #define PATCH_DEBUG (option_mask32 & FLAG_DEBUG) |
261 | |
262 | static void do_line(void *data) |
263 | { |
264 | struct double_list *dlist = (struct double_list *)data; |
265 | |
266 | if (TT.state>1 && *dlist->data != TT.state) |
267 | fdprintf(TT.state == 2 ? 2 : TT.fileout, |
268 | "%s\n", dlist->data+(TT.state>3 ? 1 : 0)); |
269 | |
270 | if (PATCH_DEBUG) fdprintf(2, "DO %d: %s\n", TT.state, dlist->data); |
271 | |
272 | free(dlist->data); |
273 | free(data); |
274 | } |
275 | |
276 | static void finish_oldfile(void) |
277 | { |
278 | if (TT.tempname) replace_tempfile(TT.filein, TT.fileout, &TT.tempname); |
279 | TT.fileout = TT.filein = -1; |
280 | } |
281 | |
282 | static void fail_hunk(void) |
283 | { |
284 | if (!TT.current_hunk) return; |
285 | TT.current_hunk->prev->next = 0; |
286 | |
287 | fdprintf(2, "Hunk %d FAILED %ld/%ld.\n", TT.hunknum, TT.oldline, TT.newline); |
288 | TT.exitval = 1; |
289 | |
290 | // If we got to this point, we've seeked to the end. Discard changes to |
291 | // this file and advance to next file. |
292 | |
293 | TT.state = 2; |
294 | TOY_llist_free(TT.current_hunk, do_line); |
295 | TT.current_hunk = NULL; |
296 | delete_tempfile(TT.filein, TT.fileout, &TT.tempname); |
297 | TT.state = 0; |
298 | } |
299 | |
300 | // Given a hunk of a unified diff, make the appropriate change to the file. |
301 | // This does not use the location information, but instead treats a hunk |
302 | // as a sort of regex. Copies data from input to output until it finds |
303 | // the change to be made, then outputs the changed data and returns. |
304 | // (Finding EOF first is an error.) This is a single pass operation, so |
305 | // multiple hunks must occur in order in the file. |
306 | |
307 | static int apply_one_hunk(void) |
308 | { |
309 | struct double_list *plist, *buf = NULL, *check; |
310 | int matcheof = 0, reverse = option_mask32 & FLAG_REVERSE, backwarn = 0; |
311 | |
312 | // Break doubly linked list so we can use singly linked traversal function. |
313 | TT.current_hunk->prev->next = NULL; |
314 | |
315 | // Match EOF if there aren't as many ending context lines as beginning |
316 | for (plist = TT.current_hunk; plist; plist = plist->next) { |
317 | if (plist->data[0]==' ') matcheof++; |
318 | else matcheof = 0; |
319 | if (PATCH_DEBUG) fdprintf(2, "HUNK:%s\n", plist->data); |
320 | } |
321 | matcheof = matcheof < TT.context; |
322 | |
323 | if (PATCH_DEBUG) fdprintf(2,"MATCHEOF=%c\n", matcheof ? 'Y' : 'N'); |
324 | |
325 | // Loop through input data searching for this hunk. Match all context |
326 | // lines and all lines to be removed until we've found the end of a |
327 | // complete hunk. |
328 | plist = TT.current_hunk; |
329 | buf = NULL; |
330 | if (TT.context) for (;;) { |
331 | char *data = get_line(TT.filein); |
332 | |
333 | TT.linenum++; |
334 | |
335 | // Figure out which line of hunk to compare with next. (Skip lines |
336 | // of the hunk we'd be adding.) |
337 | while (plist && *plist->data == "+-"[reverse]) { |
338 | if (data && strcmp(data, plist->data+1) == 0) { |
339 | if (!backwarn) { |
340 | fdprintf(2,"Possibly reversed hunk %d at %ld\n", |
341 | TT.hunknum, TT.linenum); |
342 | backwarn++; |
343 | } |
344 | } |
345 | plist = plist->next; |
346 | } |
347 | |
348 | // Is this EOF? |
349 | if (!data) { |
350 | if (PATCH_DEBUG) fdprintf(2, "INEOF\n"); |
351 | |
352 | // Does this hunk need to match EOF? |
353 | if (!plist && matcheof) break; |
354 | |
355 | // File ended before we found a place for this hunk. |
356 | fail_hunk(); |
357 | goto done; |
358 | } else if (PATCH_DEBUG) fdprintf(2, "IN: %s\n", data); |
359 | check = dlist_add(&buf, data); |
360 | |
361 | // Compare this line with next expected line of hunk. |
362 | // todo: teach the strcmp() to ignore whitespace. |
363 | |
364 | // A match can fail because the next line doesn't match, or because |
365 | // we hit the end of a hunk that needed EOF, and this isn't EOF. |
366 | |
367 | // If match failed, flush first line of buffered data and |
368 | // recheck buffered data for a new match until we find one or run |
369 | // out of buffer. |
370 | |
371 | for (;;) { |
372 | if (!plist || strcmp(check->data, plist->data+1)) { |
373 | // Match failed. Write out first line of buffered data and |
374 | // recheck remaining buffered data for a new match. |
375 | |
376 | if (PATCH_DEBUG) |
377 | fdprintf(2, "NOT: %s\n", plist->data); |
378 | |
379 | TT.state = 3; |
380 | check = TOY_llist_pop(&buf); |
381 | check->prev->next = buf; |
382 | buf->prev = check->prev; |
383 | do_line(check); |
384 | plist = TT.current_hunk; |
385 | |
386 | // If we've reached the end of the buffer without confirming a |
387 | // match, read more lines. |
388 | if (check==buf) { |
389 | buf = 0; |
390 | break; |
391 | } |
392 | check = buf; |
393 | } else { |
394 | if (PATCH_DEBUG) |
395 | fdprintf(2, "MAYBE: %s\n", plist->data); |
396 | // This line matches. Advance plist, detect successful match. |
397 | plist = plist->next; |
398 | if (!plist && !matcheof) goto out; |
399 | check = check->next; |
400 | if (check == buf) break; |
401 | } |
402 | } |
403 | } |
404 | out: |
405 | // We have a match. Emit changed data. |
406 | TT.state = "-+"[reverse]; |
407 | TOY_llist_free(TT.current_hunk, do_line); |
408 | TT.current_hunk = NULL; |
409 | TT.state = 1; |
410 | done: |
411 | if (buf) { |
412 | buf->prev->next = NULL; |
413 | TOY_llist_free(buf, do_line); |
414 | } |
415 | |
416 | return TT.state; |
417 | } |
418 | |
419 | // Read a patch file and find hunks, opening/creating/deleting files. |
420 | // Call apply_one_hunk() on each hunk. |
421 | |
422 | // state 0: Not in a hunk, look for +++. |
423 | // state 1: Found +++ file indicator, look for @@ |
424 | // state 2: In hunk: counting initial context lines |
425 | // state 3: In hunk: getting body |
426 | |
427 | int patch_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE; |
428 | int patch_main(int argc UNUSED_PARAM, char **argv) |
429 | { |
430 | int opts; |
431 | int reverse, state = 0; |
432 | char *oldname = NULL, *newname = NULL; |
433 | char *opt_p, *opt_i; |
434 | |
435 | INIT_TT(); |
436 | |
437 | opts = getopt32(argv, FLAG_STR, &opt_p, &opt_i); |
438 | reverse = opts & FLAG_REVERSE; |
439 | TT.prefix = (opts & FLAG_PATHLEN) ? xatoi(opt_p) : 0; // can be negative! |
440 | if (opts & FLAG_INPUT) TT.filepatch = xopen(opt_i, O_RDONLY); |
441 | TT.filein = TT.fileout = -1; |
442 | |
443 | // Loop through the lines in the patch |
444 | for(;;) { |
445 | char *patchline; |
446 | |
447 | patchline = get_line(TT.filepatch); |
448 | if (!patchline) break; |
449 | |
450 | // Other versions of patch accept damaged patches, |
451 | // so we need to also. |
452 | if (!*patchline) { |
453 | free(patchline); |
454 | patchline = xstrdup(" "); |
455 | } |
456 | |
457 | // Are we assembling a hunk? |
458 | if (state >= 2) { |
459 | if (*patchline==' ' || *patchline=='+' || *patchline=='-') { |
460 | dlist_add(&TT.current_hunk, patchline); |
461 | |
462 | if (*patchline != '+') TT.oldlen--; |
463 | if (*patchline != '-') TT.newlen--; |
464 | |
465 | // Context line? |
466 | if (*patchline==' ' && state==2) TT.context++; |
467 | else state=3; |
468 | |
469 | // If we've consumed all expected hunk lines, apply the hunk. |
470 | |
471 | if (!TT.oldlen && !TT.newlen) state = apply_one_hunk(); |
472 | continue; |
473 | } |
474 | fail_hunk(); |
475 | state = 0; |
476 | continue; |
477 | } |
478 | |
479 | // Open a new file? |
480 | if (!strncmp("--- ", patchline, 4) || !strncmp("+++ ", patchline, 4)) { |
481 | char *s, **name = reverse ? &newname : &oldname; |
482 | int i; |
483 | |
484 | if (*patchline == '+') { |
485 | name = reverse ? &oldname : &newname; |
486 | state = 1; |
487 | } |
488 | |
489 | free(*name); |
490 | finish_oldfile(); |
491 | |
492 | // Trim date from end of filename (if any). We don't care. |
493 | for (s = patchline+4; *s && *s!='\t'; s++) |
494 | if (*s=='\\' && s[1]) s++; |
495 | i = atoi(s); |
496 | if (i>1900 && i<=1970) |
497 | *name = xstrdup("/dev/null"); |
498 | else { |
499 | *s = 0; |
500 | *name = xstrdup(patchline+4); |
501 | } |
502 | |
503 | // We defer actually opening the file because svn produces broken |
504 | // patches that don't signal they want to create a new file the |
505 | // way the patch man page says, so you have to read the first hunk |
506 | // and _guess_. |
507 | |
508 | // Start a new hunk? |
509 | } else if (state == 1 && !strncmp("@@ -", patchline, 4)) { |
510 | int i; |
511 | |
512 | i = sscanf(patchline+4, "%ld,%ld +%ld,%ld", &TT.oldline, |
513 | &TT.oldlen, &TT.newline, &TT.newlen); |
514 | if (i != 4) |
515 | bb_error_msg_and_die("corrupt hunk %d at %ld", TT.hunknum, TT.linenum); |
516 | |
517 | TT.context = 0; |
518 | state = 2; |
519 | |
520 | // If this is the first hunk, open the file. |
521 | if (TT.filein == -1) { |
522 | int oldsum, newsum, del = 0; |
523 | char *s, *name; |
524 | |
525 | oldsum = TT.oldline + TT.oldlen; |
526 | newsum = TT.newline + TT.newlen; |
527 | |
528 | name = reverse ? oldname : newname; |
529 | |
530 | // We're deleting oldname if new file is /dev/null (before -p) |
531 | // or if new hunk is empty (zero context) after patching |
532 | if (strcmp(name, "/dev/null") == 0 || !(reverse ? oldsum : newsum)) { |
533 | name = reverse ? newname : oldname; |
534 | del++; |
535 | } |
536 | |
537 | // handle -p path truncation. |
538 | for (i=0, s = name; *s;) { |
539 | if ((option_mask32 & FLAG_PATHLEN) && TT.prefix == i) break; |
540 | if (*(s++)=='/') { |
541 | name = s; |
542 | i++; |
543 | } |
544 | } |
545 | |
546 | if (del) { |
547 | printf("removing %s\n", name); |
548 | xunlink(name); |
549 | state = 0; |
550 | // If we've got a file to open, do so. |
551 | } else if (!(option_mask32 & FLAG_PATHLEN) || i <= TT.prefix) { |
552 | // If the old file was null, we're creating a new one. |
553 | if (strcmp(oldname, "/dev/null") == 0 || !oldsum) { |
554 | printf("creating %s\n", name); |
555 | s = strrchr(name, '/'); |
556 | if (s) { |
557 | *s = 0; |
558 | xmkpath(name, -1); |
559 | *s = '/'; |
560 | } |
561 | TT.filein = xopen(name, O_CREAT|O_EXCL|O_RDWR); |
562 | } else { |
563 | printf("patching file %s\n", name); |
564 | TT.filein = xopen(name, O_RDWR); |
565 | } |
566 | TT.fileout = copy_tempfile(TT.filein, name, &TT.tempname); |
567 | TT.linenum = 0; |
568 | TT.hunknum = 0; |
569 | } |
570 | } |
571 | |
572 | TT.hunknum++; |
573 | |
574 | continue; |
575 | } |
576 | |
577 | // If we didn't continue above, discard this line. |
578 | free(patchline); |
579 | } |
580 | |
581 | finish_oldfile(); |
582 | |
583 | if (ENABLE_FEATURE_CLEAN_UP) { |
584 | close(TT.filepatch); |
585 | free(oldname); |
586 | free(newname); |
587 | } |
588 | |
589 | return TT.exitval; |
590 | } |
591 |