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.
74 void dlist_free(struct double_list *list, void (*freeit)(void *data))
80 // Bail out also if list is circular.
81 if (list == pop) break;
85 // Add an entry before "list" element in (circular) doubly linked list
87 struct double_list *dlist_add(struct double_list **list, char *data)
89 struct double_list *llist;
90 struct double_list *line = xmalloc(sizeof(*line));
95 struct double_list *p;
97 p = line->prev = llist->prev;
98 // (list is circular, we assume p is never NULL)
102 *list = line->next = line->prev = line;
112 struct double_list *current_hunk;
114 long oldline, oldlen, newline, newlen;
116 int context, state, hunknum;
122 #define TT (*ptr_to_globals)
123 #define INIT_TT() do { \
124 SET_PTR_TO_GLOBALS(xzalloc(sizeof(TT))); \
128 #define FLAG_STR "Rup:i:NEx"
129 /* FLAG_REVERSE must be == 1! Code uses this fact. */
130 #define FLAG_REVERSE (1 << 0)
131 #define FLAG_u (1 << 1)
132 #define FLAG_PATHLEN (1 << 2)
133 #define FLAG_INPUT (1 << 3)
134 #define FLAG_IGNORE (1 << 4)
135 #define FLAG_RMEMPTY (1 << 5)
136 /* Enable this bit and use -x for debug output: */
137 #define FLAG_DEBUG (0 << 6)
139 // Dispose of a line of input, either by writing it out or discarding it.
141 // state < 2: just free
142 // state = 2: write whole line to stderr
143 // state = 3: write whole line to fileout
144 // state > 3: write line+1 to fileout when *line != state
146 #define PATCH_DEBUG (option_mask32 & FLAG_DEBUG)
148 static void do_line(void *data)
150 struct double_list *dlist = data;
152 if (TT.state>1 && *dlist->data != TT.state)
153 fdprintf(TT.state == 2 ? 2 : TT.fileout,
154 "%s\n", dlist->data+(TT.state>3 ? 1 : 0));
156 if (PATCH_DEBUG) fdprintf(2, "DO %d: %s\n", TT.state, dlist->data);
162 static void finish_oldfile(void)
165 // Copy the rest of the data and replace the original with the copy.
168 if (TT.filein != -1) {
169 bb_copyfd_eof(TT.filein, TT.fileout);
174 temp = xstrdup(TT.tempname);
175 temp[strlen(temp) - 6] = '\0';
176 rename(TT.tempname, temp);
182 TT.fileout = TT.filein = -1;
185 static void fail_hunk(void)
187 if (!TT.current_hunk) return;
189 fdprintf(2, "Hunk %d FAILED %ld/%ld.\n", TT.hunknum, TT.oldline, TT.newline);
192 // If we got to this point, we've seeked to the end. Discard changes to
193 // this file and advance to next file.
196 TT.current_hunk->prev->next = NULL;
197 dlist_free(TT.current_hunk, do_line);
198 TT.current_hunk = NULL;
200 // Abort the copy and delete the temporary file.
210 // Given a hunk of a unified diff, make the appropriate change to the file.
211 // This does not use the location information, but instead treats a hunk
212 // as a sort of regex. Copies data from input to output until it finds
213 // the change to be made, then outputs the changed data and returns.
214 // (Finding EOF first is an error.) This is a single pass operation, so
215 // multiple hunks must occur in order in the file.
217 static int apply_one_hunk(void)
219 struct double_list *plist, *buf = NULL, *check;
220 int matcheof = 0, reverse = option_mask32 & FLAG_REVERSE, backwarn = 0;
221 /* Do we try "dummy" revert to check whether
222 * to silently skip this hunk? Used to implement -N.
224 int dummy_revert = 0;
226 // Break doubly linked list so we can use singly linked traversal function.
227 TT.current_hunk->prev->next = NULL;
229 // Match EOF if there aren't as many ending context lines as beginning
230 for (plist = TT.current_hunk; plist; plist = plist->next) {
231 if (plist->data[0]==' ') matcheof++;
233 if (PATCH_DEBUG) fdprintf(2, "HUNK:%s\n", plist->data);
235 matcheof = matcheof < TT.context;
237 if (PATCH_DEBUG) fdprintf(2,"MATCHEOF=%c\n", matcheof ? 'Y' : 'N');
239 // Loop through input data searching for this hunk. Match all context
240 // lines and all lines to be removed until we've found the end of a
242 plist = TT.current_hunk;
244 if (reverse ? TT.oldlen : TT.newlen) for (;;) {
245 char *data = xmalloc_reads(TT.filein, NULL);
249 // Figure out which line of hunk to compare with next. (Skip lines
250 // of the hunk we'd be adding.)
251 while (plist && *plist->data == "+-"[reverse]) {
252 if (data && !strcmp(data, plist->data+1)) {
254 backwarn = TT.linenum;
255 if (option_mask32 & FLAG_IGNORE) {
267 if (PATCH_DEBUG) fdprintf(2, "INEOF\n");
269 // Does this hunk need to match EOF?
270 if (!plist && matcheof) break;
273 fdprintf(2,"Possibly reversed hunk %d at %ld\n",
274 TT.hunknum, TT.linenum);
276 // File ended before we found a place for this hunk.
281 if (PATCH_DEBUG) fdprintf(2, "IN: %s\n", data);
282 check = dlist_add(&buf, data);
284 // Compare this line with next expected line of hunk.
285 // todo: teach the strcmp() to ignore whitespace.
287 // A match can fail because the next line doesn't match, or because
288 // we hit the end of a hunk that needed EOF, and this isn't EOF.
290 // If match failed, flush first line of buffered data and
291 // recheck buffered data for a new match until we find one or run
295 if (!plist || strcmp(check->data, plist->data+1)) {
296 // Match failed. Write out first line of buffered data and
297 // recheck remaining buffered data for a new match.
300 fdprintf(2, "NOT: %s\n", plist->data);
305 check->prev->next = buf;
306 buf->prev = check->prev;
308 plist = TT.current_hunk;
310 // If we've reached the end of the buffer without confirming a
311 // match, read more lines.
319 fdprintf(2, "MAYBE: %s\n", plist->data);
320 // This line matches. Advance plist, detect successful match.
322 if (!plist && !matcheof) goto out;
324 if (check == buf) break;
329 // We have a match. Emit changed data.
330 TT.state = "-+"[reverse ^ dummy_revert];
331 dlist_free(TT.current_hunk, do_line);
332 TT.current_hunk = NULL;
336 buf->prev->next = NULL;
337 dlist_free(buf, do_line);
343 // Read a patch file and find hunks, opening/creating/deleting files.
344 // Call apply_one_hunk() on each hunk.
346 // state 0: Not in a hunk, look for +++.
347 // state 1: Found +++ file indicator, look for @@
348 // state 2: In hunk: counting initial context lines
349 // state 3: In hunk: getting body
351 int patch_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
352 int patch_main(int argc UNUSED_PARAM, char **argv)
355 int reverse, state = 0;
356 char *oldname = NULL, *newname = NULL;
358 long oldlen = oldlen; /* for compiler */
359 long newlen = newlen; /* for compiler */
363 opts = getopt32(argv, FLAG_STR, &opt_p, &opt_i);
365 reverse = opts & FLAG_REVERSE;
366 TT.prefix = (opts & FLAG_PATHLEN) ? xatoi(opt_p) : 0; // can be negative!
367 TT.filein = TT.fileout = -1;
368 if (opts & FLAG_INPUT) {
369 xmove_fd(xopen_stdin(opt_i), STDIN_FILENO);
371 if (argv[0] && argv[1]) {
372 xmove_fd(xopen_stdin(argv[1]), STDIN_FILENO);
376 oldname = xstrdup(argv[0]);
377 newname = xstrdup(argv[0]);
380 // Loop through the lines in the patch
384 patchline = xmalloc_fgetline(stdin);
385 if (!patchline) break;
387 // Other versions of patch accept damaged patches,
388 // so we need to also.
391 patchline = xstrdup(" ");
394 // Are we assembling a hunk?
396 if (*patchline==' ' || *patchline=='+' || *patchline=='-') {
397 dlist_add(&TT.current_hunk, patchline);
399 if (*patchline != '+') oldlen--;
400 if (*patchline != '-') newlen--;
403 if (*patchline==' ' && state==2) TT.context++;
406 // If we've consumed all expected hunk lines, apply the hunk.
408 if (!oldlen && !newlen) state = apply_one_hunk();
417 if (!strncmp("--- ", patchline, 4) || !strncmp("+++ ", patchline, 4)) {
418 char *s, **name = reverse ? &newname : &oldname;
421 if (*patchline == '+') {
422 name = reverse ? &oldname : &newname;
430 // Trim date from end of filename (if any). We don't care.
431 for (s = patchline+4; *s && *s!='\t'; s++)
432 if (*s=='\\' && s[1]) s++;
434 if (i>1900 && i<=1970)
435 *name = xstrdup("/dev/null");
438 *name = xstrdup(patchline+4);
442 // We defer actually opening the file because svn produces broken
443 // patches that don't signal they want to create a new file the
444 // way the patch man page says, so you have to read the first hunk
447 // Start a new hunk? Usually @@ -oldline,oldlen +newline,newlen @@
448 // but a missing ,value means the value is 1.
449 } else if (state == 1 && !strncmp("@@ -", patchline, 4)) {
451 char *s = patchline+4;
453 // Read oldline[,oldlen] +newline[,newlen]
455 TT.oldlen = oldlen = TT.newlen = newlen = 1;
456 TT.oldline = strtol(s, &s, 10);
457 if (*s == ',') TT.oldlen = oldlen = strtol(s+1, &s, 10);
458 TT.newline = strtol(s+2, &s, 10);
459 if (*s == ',') TT.newlen = newlen = strtol(s+1, &s, 10);
461 if (oldlen < 1 && newlen < 1)
462 bb_error_msg_and_die("Really? %s", patchline);
467 // If this is the first hunk, open the file.
468 if (TT.filein == -1) {
469 int oldsum, newsum, empty = 0;
472 oldsum = TT.oldline + oldlen;
473 newsum = TT.newline + newlen;
475 name = reverse ? oldname : newname;
477 // We're deleting oldname if new file is /dev/null (before -p)
478 // or if new hunk is empty (zero context) after patching
479 if (!strcmp(name, "/dev/null") || !(reverse ? oldsum : newsum))
481 name = reverse ? newname : oldname;
485 // handle -p path truncation.
486 for (i=0, s = name; *s;) {
487 if ((option_mask32 & FLAG_PATHLEN) && TT.prefix == i) break;
495 // File is empty after the patches have been applied
497 if (option_mask32 & FLAG_RMEMPTY) {
498 // If flag -E or --remove-empty-files is set
499 printf("removing %s\n", name);
502 printf("patching file %s\n", name);
503 xclose(xopen(name, O_WRONLY | O_TRUNC));
505 // If we've got a file to open, do so.
506 } else if (!(option_mask32 & FLAG_PATHLEN) || i <= TT.prefix) {
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, '/');
515 bb_make_directory(name, -1, FILEUTILS_RECUR);
518 TT.filein = xopen(name, O_CREAT|O_EXCL|O_RDWR);
520 printf("patching file %s\n", name);
521 TT.filein = xopen(name, O_RDONLY);
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);
540 // If we didn't continue above, discard this line.
546 if (ENABLE_FEATURE_CLEAN_UP) {