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.
dlist_free(struct double_list * list,void (* freeit)(void * data))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
dlist_add(struct double_list ** list,char * data)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
do_line(void * data)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
finish_oldfile(void)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
fail_hunk(void)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
apply_one_hunk(void)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) == 0) {
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 while (plist && *plist->data == "+-"[reverse]) {
294 if (strcmp(check->data, plist->data+1) == 0
295 && !backwarn
296 ) {
297 backwarn = TT.linenum;
298 if (option_mask32 & FLAG_IGNORE) {
299 dummy_revert = 1;
300 reverse ^= 1;
301 }
302 }
303 plist = plist->next;
304 }
305 if (!plist || strcmp(check->data, plist->data+1)) {
306 // Match failed. Write out first line of buffered data and
307 // recheck remaining buffered data for a new match.
308
309 if (PATCH_DEBUG)
310 fdprintf(2, "NOT: %s\n", plist ? plist->data : "EOF");
311
312 TT.state = 3;
313 check = buf;
314 buf = buf->next;
315 check->prev->next = buf;
316 buf->prev = check->prev;
317 do_line(check);
318 plist = TT.current_hunk;
319
320 // If we've reached the end of the buffer without confirming a
321 // match, read more lines.
322 if (check == buf) {
323 buf = NULL;
324 break;
325 }
326 check = buf;
327 } else {
328 if (PATCH_DEBUG)
329 fdprintf(2, "MAYBE: %s\n", plist->data);
330 // This line matches. Advance plist, detect successful match.
331 plist = plist->next;
332 if (!plist && !matcheof) goto out;
333 check = check->next;
334 if (check == buf) break;
335 }
336 }
337 }
338 out:
339 // We have a match. Emit changed data.
340 TT.state = "-+"[reverse ^ dummy_revert];
341 dlist_free(TT.current_hunk, do_line);
342 TT.current_hunk = NULL;
343 TT.state = 1;
344 done:
345 if (buf) {
346 buf->prev->next = NULL;
347 dlist_free(buf, do_line);
348 }
349
350 return TT.state;
351 }
352
353 // Read a patch file and find hunks, opening/creating/deleting files.
354 // Call apply_one_hunk() on each hunk.
355
356 // state 0: Not in a hunk, look for +++.
357 // state 1: Found +++ file indicator, look for @@
358 // state 2: In hunk: counting initial context lines
359 // state 3: In hunk: getting body
360 // Like GNU patch, we don't require a --- line before the +++, and
361 // also allow the --- after the +++ line.
362
363 int patch_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
patch_main(int argc UNUSED_PARAM,char ** argv)364 int patch_main(int argc UNUSED_PARAM, char **argv)
365 {
366 int opts;
367 int reverse, state = 0;
368 char *oldname = NULL, *newname = NULL;
369 char *opt_p, *opt_i;
370 long oldlen = oldlen; /* for compiler */
371 long newlen = newlen; /* for compiler */
372
373 INIT_TT();
374
375 opts = getopt32(argv, FLAG_STR, &opt_p, &opt_i);
376 argv += optind;
377 reverse = opts & FLAG_REVERSE;
378 TT.prefix = (opts & FLAG_PATHLEN) ? xatoi(opt_p) : 0; // can be negative!
379 TT.filein = TT.fileout = -1;
380 if (opts & FLAG_INPUT) {
381 xmove_fd(xopen_stdin(opt_i), STDIN_FILENO);
382 } else {
383 if (argv[0] && argv[1]) {
384 xmove_fd(xopen_stdin(argv[1]), STDIN_FILENO);
385 }
386 }
387
388 // Loop through the lines in the patch
389 for(;;) {
390 char *patchline;
391
392 patchline = xmalloc_fgetline(stdin);
393 if (!patchline) break;
394
395 // Other versions of patch accept damaged patches,
396 // so we need to also.
397 if (!*patchline) {
398 free(patchline);
399 patchline = xstrdup(" ");
400 }
401
402 // Are we assembling a hunk?
403 if (state >= 2) {
404 if (*patchline==' ' || *patchline=='+' || *patchline=='-') {
405 dlist_add(&TT.current_hunk, patchline);
406
407 if (*patchline != '+') oldlen--;
408 if (*patchline != '-') newlen--;
409
410 // Context line?
411 if (*patchline==' ' && state==2) TT.context++;
412 else state=3;
413
414 // If we've consumed all expected hunk lines, apply the hunk.
415
416 if (!oldlen && !newlen) state = apply_one_hunk();
417 continue;
418 }
419 fail_hunk();
420 state = 0;
421 continue;
422 }
423
424 // Open a new file?
425 if (is_prefixed_with(patchline, "--- ") || is_prefixed_with(patchline, "+++ ")) {
426 char *s, **name = reverse ? &newname : &oldname;
427 int i;
428
429 if (*patchline == '+') {
430 name = reverse ? &oldname : &newname;
431 state = 1;
432 }
433
434 finish_oldfile();
435
436 if (!argv[0]) {
437 free(*name);
438 // Trim date from end of filename (if any). We don't care.
439 for (s = patchline+4; *s && *s!='\t'; s++)
440 if (*s=='\\' && s[1]) s++;
441 i = atoi(s);
442 if (i>1900 && i<=1970)
443 *name = xstrdup("/dev/null");
444 else {
445 *s = 0;
446 *name = xstrdup(patchline+4);
447 }
448 }
449
450 // We defer actually opening the file because svn produces broken
451 // patches that don't signal they want to create a new file the
452 // way the patch man page says, so you have to read the first hunk
453 // and _guess_.
454
455 // Start a new hunk? Usually @@ -oldline,oldlen +newline,newlen @@
456 // but a missing ,value means the value is 1.
457 } else if (state == 1 && is_prefixed_with(patchline, "@@ -")) {
458 int i;
459 char *s = patchline+4;
460
461 // Read oldline[,oldlen] +newline[,newlen]
462
463 TT.oldlen = oldlen = TT.newlen = newlen = 1;
464 TT.oldline = strtol(s, &s, 10);
465 if (*s == ',') TT.oldlen = oldlen = strtol(s+1, &s, 10);
466 TT.newline = strtol(s+2, &s, 10);
467 if (*s == ',') TT.newlen = newlen = strtol(s+1, &s, 10);
468
469 if (oldlen < 1 && newlen < 1)
470 bb_error_msg_and_die("Really? %s", patchline);
471
472 TT.context = 0;
473 state = 2;
474
475 // If the --- line is missing or malformed, either oldname
476 // or (for -R) newname could be NULL -- but not both. Like
477 // GNU patch, proceed based on the +++ line, and avoid SEGVs.
478 if (!oldname)
479 oldname = xstrdup("MISSING_FILENAME");
480 if (!newname)
481 newname = xstrdup("MISSING_FILENAME");
482
483 // If this is the first hunk, open the file.
484 if (TT.filein == -1) {
485 int oldsum, newsum, empty = 0;
486 char *name;
487
488 oldsum = TT.oldline + oldlen;
489 newsum = TT.newline + newlen;
490
491 name = reverse ? oldname : newname;
492
493 // We're deleting oldname if new file is /dev/null (before -p)
494 // or if new hunk is empty (zero context) after patching
495 if (strcmp(name, "/dev/null") == 0 || !(reverse ? oldsum : newsum)) {
496 name = reverse ? newname : oldname;
497 empty = 1;
498 }
499
500 // Handle -p path truncation.
501 for (i = 0, s = name; *s;) {
502 if ((option_mask32 & FLAG_PATHLEN) && TT.prefix == i)
503 break;
504 if (*s++ != '/')
505 continue;
506 while (*s == '/')
507 s++;
508 i++;
509 name = s;
510 }
511 // If "patch FILE_TO_PATCH", completely ignore name from patch
512 if (argv[0])
513 name = argv[0];
514
515 if (empty) {
516 // File is empty after the patches have been applied
517 state = 0;
518 if (option_mask32 & FLAG_RMEMPTY) {
519 // If flag -E or --remove-empty-files is set
520 printf("removing %s\n", name);
521 xunlink(name);
522 } else {
523 printf("patching file %s\n", name);
524 xclose(xopen(name, O_WRONLY | O_TRUNC));
525 }
526 // If we've got a file to open, do so.
527 } else if (!(option_mask32 & FLAG_PATHLEN) || i <= TT.prefix) {
528 struct stat statbuf;
529
530 // If the old file was null, we're creating a new one.
531 if (strcmp(oldname, "/dev/null") == 0 || !oldsum) {
532 printf("creating %s\n", name);
533 s = strrchr(name, '/');
534 if (s) {
535 *s = 0;
536 bb_make_directory(name, -1, FILEUTILS_RECUR);
537 *s = '/';
538 }
539 TT.filein = xopen(name, O_CREAT|O_EXCL|O_RDWR);
540 } else {
541 printf("patching file %s\n", name);
542 TT.filein = xopen(name, O_RDONLY);
543 }
544
545 TT.tempname = xasprintf("%sXXXXXX", name);
546 TT.fileout = xmkstemp(TT.tempname);
547 // Set permissions of output file
548 fstat(TT.filein, &statbuf);
549 fchmod(TT.fileout, statbuf.st_mode);
550
551 TT.linenum = 0;
552 TT.hunknum = 0;
553 }
554 }
555
556 TT.hunknum++;
557
558 continue;
559 }
560
561 // If we didn't continue above, discard this line.
562 free(patchline);
563 }
564
565 finish_oldfile();
566
567 if (ENABLE_FEATURE_CLEAN_UP) {
568 free(oldname);
569 free(newname);
570 }
571
572 return TT.exitval;
573 }
574