3 * Apply a "universal" diff.
4 * Adapted from toybox's patch implementation.
6 * Copyright 2007 Rob Landley <rob@landley.net>
8 * see http://www.opengroup.org/onlinepubs/009695399/utilities/patch.html
9 * (But only does -u, because who still cares about "ed"?)
13 * -l treat all whitespace as a single space
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!)
20 * -f force (no questions asked)
21 * -F fuzz (number, default 2)
22 * [file] which file to patch
26 //config: bool "patch"
29 //config: Apply a unified diff formatted patch.
31 //applet:IF_PATCH(APPLET(patch, BB_DIR_USR_BIN, BB_SUID_DROP))
33 //kbuild:lib-$(CONFIG_PATCH) += patch.o
35 //usage:#define patch_trivial_usage
36 //usage: "[OPTIONS] [ORIGFILE [PATCHFILE]]"
37 //usage:#define patch_full_usage "\n\n"
38 //usage: IF_LONG_OPTS(
39 //usage: " -p,--strip N Strip N leading components from file names"
40 //usage: "\n -i,--input DIFF Read DIFF instead of stdin"
41 //usage: "\n -R,--reverse Reverse patch"
42 //usage: "\n -N,--forward Ignore already applied patches"
43 /*usage: "\n --dry-run Don't actually change files" - TODO */
44 //usage: "\n -E,--remove-empty-files Remove output files if they become empty"
46 //usage: IF_NOT_LONG_OPTS(
47 //usage: " -p N Strip N leading components from file names"
48 //usage: "\n -i DIFF Read DIFF instead of stdin"
49 //usage: "\n -R Reverse patch"
50 //usage: "\n -N Ignore already applied patches"
51 //usage: "\n -E Remove output files if they become empty"
53 /* -u "interpret as unified diff" is supported but not documented: this info is not useful for --help */
54 /* -x "debug" is supported but does nothing */
56 //usage:#define patch_example_usage
57 //usage: "$ patch -p1 < example.diff\n"
58 //usage: "$ patch -p0 -i example.diff"
66 struct double_list *next;
67 struct double_list *prev;
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))
79 // Bail out also if list is circular.
80 if (list == pop) break;
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)
87 struct double_list *llist;
88 struct double_list *line = xmalloc(sizeof(*line));
93 struct double_list *p;
95 p = line->prev = llist->prev;
96 // (list is circular, we assume p is never NULL)
100 *list = line->next = line->prev = line;
110 struct double_list *current_hunk;
112 long oldline, oldlen, newline, newlen;
114 int context, state, hunknum;
120 #define TT (*ptr_to_globals)
121 #define INIT_TT() do { \
122 SET_PTR_TO_GLOBALS(xzalloc(sizeof(TT))); \
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)
137 // Dispose of a line of input, either by writing it out or discarding it.
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
144 #define PATCH_DEBUG (option_mask32 & FLAG_DEBUG)
146 static void do_line(void *data)
148 struct double_list *dlist = data;
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));
154 if (PATCH_DEBUG) fdprintf(2, "DO %d: %s\n", TT.state, dlist->data);
160 static void finish_oldfile(void)
163 // Copy the rest of the data and replace the original with the copy.
166 if (TT.filein != -1) {
167 bb_copyfd_eof(TT.filein, TT.fileout);
172 temp = xstrdup(TT.tempname);
173 temp[strlen(temp) - 6] = '\0';
174 rename(TT.tempname, temp);
180 TT.fileout = TT.filein = -1;
183 static void fail_hunk(void)
185 if (!TT.current_hunk) return;
187 fdprintf(2, "Hunk %d FAILED %ld/%ld.\n", TT.hunknum, TT.oldline, TT.newline);
190 // If we got to this point, we've seeked to the end. Discard changes to
191 // this file and advance to next file.
194 TT.current_hunk->prev->next = NULL;
195 dlist_free(TT.current_hunk, do_line);
196 TT.current_hunk = NULL;
198 // Abort the copy and delete the temporary file.
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.
215 static int apply_one_hunk(void)
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.
222 int dummy_revert = 0;
224 // Break doubly linked list so we can use singly linked traversal function.
225 TT.current_hunk->prev->next = NULL;
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++;
231 if (PATCH_DEBUG) fdprintf(2, "HUNK:%s\n", plist->data);
233 matcheof = !matcheof || matcheof < TT.context;
235 if (PATCH_DEBUG) fdprintf(2,"MATCHEOF=%c\n", matcheof ? 'Y' : 'N');
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
240 plist = TT.current_hunk;
242 if (reverse ? TT.oldlen : TT.newlen) for (;;) {
243 char *data = xmalloc_reads(TT.filein, NULL);
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) {
252 backwarn = TT.linenum;
253 if (option_mask32 & FLAG_IGNORE) {
265 if (PATCH_DEBUG) fdprintf(2, "INEOF\n");
267 // Does this hunk need to match EOF?
268 if (!plist && matcheof) break;
271 fdprintf(2,"Possibly reversed hunk %d at %ld\n",
272 TT.hunknum, TT.linenum);
274 // File ended before we found a place for this hunk.
279 if (PATCH_DEBUG) fdprintf(2, "IN: %s\n", data);
280 check = dlist_add(&buf, data);
282 // Compare this line with next expected line of hunk.
283 // todo: teach the strcmp() to ignore whitespace.
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.
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
293 while (plist && *plist->data == "+-"[reverse]) {
294 if (strcmp(check->data, plist->data+1) == 0
297 backwarn = TT.linenum;
298 if (option_mask32 & FLAG_IGNORE) {
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.
310 fdprintf(2, "NOT: %s\n", plist ? plist->data : "EOF");
315 check->prev->next = buf;
316 buf->prev = check->prev;
318 plist = TT.current_hunk;
320 // If we've reached the end of the buffer without confirming a
321 // match, read more lines.
329 fdprintf(2, "MAYBE: %s\n", plist->data);
330 // This line matches. Advance plist, detect successful match.
332 if (!plist && !matcheof) goto out;
334 if (check == buf) break;
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;
346 buf->prev->next = NULL;
347 dlist_free(buf, do_line);
353 // Read a patch file and find hunks, opening/creating/deleting files.
354 // Call apply_one_hunk() on each hunk.
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.
363 int patch_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
364 int patch_main(int argc UNUSED_PARAM, char **argv)
367 int reverse, state = 0;
368 char *oldname = NULL, *newname = NULL;
370 long oldlen = oldlen; /* for compiler */
371 long newlen = newlen; /* for compiler */
375 opts = getopt32(argv, FLAG_STR, &opt_p, &opt_i);
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);
383 if (argv[0] && argv[1]) {
384 xmove_fd(xopen_stdin(argv[1]), STDIN_FILENO);
388 // Loop through the lines in the patch
392 patchline = xmalloc_fgetline(stdin);
393 if (!patchline) break;
395 // Other versions of patch accept damaged patches,
396 // so we need to also.
399 patchline = xstrdup(" ");
402 // Are we assembling a hunk?
404 if (*patchline==' ' || *patchline=='+' || *patchline=='-') {
405 dlist_add(&TT.current_hunk, patchline);
407 if (*patchline != '+') oldlen--;
408 if (*patchline != '-') newlen--;
411 if (*patchline==' ' && state==2) TT.context++;
414 // If we've consumed all expected hunk lines, apply the hunk.
416 if (!oldlen && !newlen) state = apply_one_hunk();
425 if (is_prefixed_with(patchline, "--- ") || is_prefixed_with(patchline, "+++ ")) {
426 char *s, **name = reverse ? &newname : &oldname;
429 if (*patchline == '+') {
430 name = reverse ? &oldname : &newname;
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++;
442 if (i>1900 && i<=1970)
443 *name = xstrdup("/dev/null");
446 *name = xstrdup(patchline+4);
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
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, "@@ -")) {
459 char *s = patchline+4;
461 // Read oldline[,oldlen] +newline[,newlen]
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);
469 if (oldlen < 1 && newlen < 1)
470 bb_error_msg_and_die("Really? %s", patchline);
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.
479 oldname = xstrdup("MISSING_FILENAME");
481 newname = xstrdup("MISSING_FILENAME");
483 // If this is the first hunk, open the file.
484 if (TT.filein == -1) {
485 int oldsum, newsum, empty = 0;
488 oldsum = TT.oldline + oldlen;
489 newsum = TT.newline + newlen;
491 name = reverse ? oldname : newname;
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;
500 // Handle -p path truncation.
501 for (i = 0, s = name; *s;) {
502 if ((option_mask32 & FLAG_PATHLEN) && TT.prefix == i)
511 // If "patch FILE_TO_PATCH", completely ignore name from patch
516 // File is empty after the patches have been applied
518 if (option_mask32 & FLAG_RMEMPTY) {
519 // If flag -E or --remove-empty-files is set
520 printf("removing %s\n", name);
523 printf("patching file %s\n", name);
524 xclose(xopen(name, O_WRONLY | O_TRUNC));
526 // If we've got a file to open, do so.
527 } else if (!(option_mask32 & FLAG_PATHLEN) || i <= TT.prefix) {
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, '/');
536 bb_make_directory(name, -1, FILEUTILS_RECUR);
539 TT.filein = xopen(name, O_CREAT|O_EXCL|O_RDWR);
541 printf("patching file %s\n", name);
542 TT.filein = xopen(name, O_RDONLY);
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);
561 // If we didn't continue above, discard this line.
567 if (ENABLE_FEATURE_CLEAN_UP) {