patch: add Rob's version for reference, it may handle fuzz and offsets
authorDenys Vlasenko <vda.linux@googlemail.com>
Sat, 24 Oct 2009 22:39:51 +0000 (00:39 +0200)
committerDenys Vlasenko <vda.linux@googlemail.com>
Sat, 24 Oct 2009 22:39:51 +0000 (00:39 +0200)
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
editors/patch_toybox.c [new file with mode: 0644]

diff --git a/editors/patch_toybox.c b/editors/patch_toybox.c
new file mode 100644 (file)
index 0000000..f1e0de6
--- /dev/null
@@ -0,0 +1,559 @@
+/* Adapted from toybox's patch. Currently unused */
+
+/* vi: set sw=4 ts=4:
+ *
+ * patch.c - Apply a "universal" diff.
+ *
+ * Copyright 2007 Rob Landley <rob@landley.net>
+ *
+ * see http://www.opengroup.org/onlinepubs/009695399/utilities/patch.html
+ * (But only does -u, because who still cares about "ed"?)
+ *
+ * TODO:
+ * -b backup
+ * -l treat all whitespace as a single space
+ * -N ignore already applied
+ * -d chdir first
+ * -D define wrap #ifdef and #ifndef around changes
+ * -o outfile output here instead of in place
+ * -r rejectfile write rejected hunks to this file
+ *
+ * -E remove empty files --remove-empty-files
+ * -f force (no questions asked)
+ * -F fuzz (number, default 2)
+ * [file] which file to patch
+
+USE_PATCH(NEWTOY(patch, "up#i:R", TOYFLAG_USR|TOYFLAG_BIN))
+
+config PATCH
+       bool "patch"
+       default y
+       help
+         usage: patch [-i file] [-p depth] [-Ru]
+
+         Apply a unified diff to one or more files.
+
+         -i    Input file (defaults=stdin)
+         -p    number of '/' to strip from start of file paths (default=all)
+         -R    Reverse patch.
+         -u    Ignored (only handles "unified" diffs)
+
+         This version of patch only handles unified diffs, and only modifies
+         a file when all all hunks to that file apply.  Patch prints failed
+         hunks to stderr, and exits with nonzero status if any hunks fail.
+
+         A file compared against /dev/null (or with a date <= the epoch) is
+         created/deleted as appropriate.
+*/
+#include "libbb.h"
+
+struct double_list {
+       struct double_list *next;
+       struct double_list *prev;
+       char *data;
+};
+
+// Return the first item from the list, advancing the list (which must be called
+// as &list)
+static
+void *TOY_llist_pop(void *list)
+{
+       // I'd use a void ** for the argument, and even accept the typecast in all
+       // callers as documentation you need the &, except the stupid compiler
+       // would then scream about type-punned pointers.  Screw it.
+       void **llist = (void **)list;
+       void **next = (void **)*llist;
+       *llist = *next;
+
+       return (void *)next;
+}
+
+// Free all the elements of a linked list
+// if freeit!=NULL call freeit() on each element before freeing it.
+static
+void TOY_llist_free(void *list, void (*freeit)(void *data))
+{
+       while (list) {
+               void *pop = TOY_llist_pop(&list);
+               if (freeit) freeit(pop);
+               else free(pop);
+
+               // End doubly linked list too.
+               if (list==pop) break;
+       }
+}
+
+// Add an entry to the end off a doubly linked list
+static
+struct double_list *dlist_add(struct double_list **list, char *data)
+{
+       struct double_list *line = xmalloc(sizeof(struct double_list));
+
+       line->data = data;
+       if (*list) {
+               line->next = *list;
+               line->prev = (*list)->prev;
+               (*list)->prev->next = line;
+               (*list)->prev = line;
+       } else *list = line->next = line->prev = line;
+
+       return line;
+}
+
+// Ensure entire path exists.
+// If mode != -1 set permissions on newly created dirs.
+// Requires that path string be writable (for temporary null terminators).
+static
+void xmkpath(char *path, int mode)
+{
+       char *p, old;
+       mode_t mask;
+       int rc;
+       struct stat st;
+
+       for (p = path; ; p++) {
+               if (!*p || *p == '/') {
+                       old = *p;
+                       *p = rc = 0;
+                       if (stat(path, &st) || !S_ISDIR(st.st_mode)) {
+                               if (mode != -1) {
+                                       mask = umask(0);
+                                       rc = mkdir(path, mode);
+                                       umask(mask);
+                               } else rc = mkdir(path, 0777);
+                       }
+                       *p = old;
+                       if(rc) bb_perror_msg_and_die("mkpath '%s'", path);
+               }
+               if (!*p) break;
+       }
+}
+
+// Slow, but small.
+static
+char *get_rawline(int fd, long *plen, char end)
+{
+       char c, *buf = NULL;
+       long len = 0;
+
+       for (;;) {
+               if (1>read(fd, &c, 1)) break;
+               if (!(len & 63)) buf=xrealloc(buf, len+65);
+               if ((buf[len++]=c) == end) break;
+       }
+       if (buf) buf[len]=0;
+       if (plen) *plen = len;
+
+       return buf;
+}
+
+static
+char *get_line(int fd)
+{
+       long len;
+       char *buf = get_rawline(fd, &len, '\n');
+
+       if (buf && buf[--len]=='\n') buf[len]=0;
+
+       return buf;
+}
+
+// Copy the rest of in to out and close both files.
+static
+void xsendfile(int in, int out)
+{
+       long len;
+       char buf[4096];
+
+       if (in<0) return;
+       for (;;) {
+               len = safe_read(in, buf, 4096);
+               if (len<1) break;
+               xwrite(out, buf, len);
+       }
+}
+
+// Copy the rest of the data and replace the original with the copy.
+static
+void replace_tempfile(int fdin, int fdout, char **tempname)
+{
+       char *temp = xstrdup(*tempname);
+
+       temp[strlen(temp)-6]=0;
+       if (fdin != -1) {
+               xsendfile(fdin, fdout);
+               xclose(fdin);
+       }
+       xclose(fdout);
+       rename(*tempname, temp);
+       free(*tempname);
+       free(temp);
+       *tempname = NULL;
+}
+
+// Open a temporary file to copy an existing file into.
+static
+int copy_tempfile(int fdin, char *name, char **tempname)
+{
+       struct stat statbuf;
+       int fd;
+
+       *tempname = xasprintf("%sXXXXXX", name);
+       fd = mkstemp(*tempname);
+       if(-1 == fd) bb_perror_msg_and_die("no temp file");
+
+       // Set permissions of output file
+       fstat(fdin, &statbuf);
+       fchmod(fd, statbuf.st_mode);
+
+       return fd;
+}
+
+// Abort the copy and delete the temporary file.
+static
+void delete_tempfile(int fdin, int fdout, char **tempname)
+{
+       close(fdin);
+       close(fdout);
+       unlink(*tempname);
+       free(*tempname);
+       *tempname = NULL;
+}
+
+
+
+struct globals {
+       struct double_list *plines;
+       long linenum;
+       int context;
+       int hunknum;
+       int filein;
+       int fileout;
+       int state;
+       char *tempname;
+       smallint exitval;
+};
+#define TT (*ptr_to_globals)
+#define INIT_TT() do { \
+       SET_PTR_TO_GLOBALS(xzalloc(sizeof(TT))); \
+} while (0)
+
+
+//bbox had: "p:i:RN"
+#define FLAG_STR "Rup:i:"
+/* FLAG_REVERSE must be == 1! Code uses this fact. */
+#define FLAG_REVERSE (1 << 0)
+#define FLAG_u       (1 << 1)
+#define FLAG_PATHLEN (1 << 2)
+#define FLAG_INPUT   (1 << 3)
+
+// Dispose of a line of input, either by writing it out or discarding it.
+
+// state < 2: just free
+// state = 2: write whole line to stderr
+// state = 3: write whole line to fileout
+// state > 3: write line+1 to fileout when *line != state
+
+static void do_line(void *data)
+{
+       struct double_list *dlist = (struct double_list *)data;
+
+       if (TT.state>1 && *dlist->data != TT.state)
+               fdprintf(TT.state == 2 ? 2 : TT.fileout,
+                       "%s\n", dlist->data+(TT.state>3 ? 1 : 0));
+
+       free(dlist->data);
+       free(data);
+}
+
+static void finish_oldfile(void)
+{
+       if (TT.tempname) replace_tempfile(TT.filein, TT.fileout, &TT.tempname);
+       TT.fileout = TT.filein = -1;
+}
+
+static void fail_hunk(void)
+{
+       if (!TT.plines) return;
+       TT.plines->prev->next = 0;
+
+       fdprintf(2, "Hunk %d FAILED.\n", TT.hunknum);
+       TT.exitval = 1;
+
+       // If we got to this point, we've seeked to the end.  Discard changes to
+       // this file and advance to next file.
+
+       TT.state = 2;
+       TOY_llist_free(TT.plines, do_line);
+       TT.plines = NULL;
+       delete_tempfile(TT.filein, TT.fileout, &TT.tempname);
+       TT.state = 0;
+}
+
+static int apply_hunk(void)
+{
+       struct double_list *plist, *buf = NULL, *check;
+       int i = 0, backwards = 0, matcheof = 0,
+               reverse = option_mask32 & FLAG_REVERSE;
+
+       // Break doubly linked list so we can use singly linked traversal function.
+       TT.plines->prev->next = NULL;
+
+       // Match EOF if there aren't as many ending context lines as beginning
+       for (plist = TT.plines; plist; plist = plist->next) {
+               if (plist->data[0]==' ') i++;
+               else i = 0;
+       }
+       if (i < TT.context) matcheof++;
+
+       // Search for a place to apply this hunk.  Match all context lines and
+       // lines to be removed.
+       plist = TT.plines;
+       buf = NULL;
+       i = 0;
+
+       // Start of for loop
+       if (TT.context) for (;;) {
+               char *data = get_line(TT.filein);
+
+               TT.linenum++;
+
+               // Skip lines of the hunk we'd be adding.
+               while (plist && *plist->data == "+-"[reverse]) {
+                       if (data && !strcmp(data, plist->data+1)) {
+                               if (++backwards == TT.context)
+                                       fdprintf(2,"Possibly reversed hunk %d at %ld\n",
+                                               TT.hunknum, TT.linenum);
+                       } else backwards=0;
+                       plist = plist->next;
+               }
+
+               // Is this EOF?
+               if (!data) {
+                       // Does this hunk need to match EOF?
+                       if (!plist && matcheof) break;
+
+                       // File ended before we found a place for this hunk.
+                       fail_hunk();
+                       goto done;
+               }
+               check = dlist_add(&buf, data);
+
+               // todo: teach the strcmp() to ignore whitespace.
+
+               for (;;) {
+                       // If we hit the end of a hunk that needed EOF and this isn't EOF,
+                       // or next line doesn't match, flush first line of buffered data and
+                       // recheck match until we find a new match or run out of buffer.
+
+                       if (!plist || strcmp(check->data, plist->data+1)) {
+                               // First line isn't a match, write it out.
+                               TT.state = 3;
+                               check = TOY_llist_pop(&buf);
+                               check->prev->next = buf;
+                               buf->prev = check->prev;
+                               do_line(check);
+                               plist = TT.plines;
+
+                               // Out of buffered lines?
+                               if (check==buf) {
+                                       buf = 0;
+                                       break;
+                               }
+                               check = buf;
+                       } else {
+                               // This line matches.  Advance plist, detect successful match.
+                               plist = plist->next;
+                               if (!plist && !matcheof) goto out;
+                               check = check->next;
+                               if (check == buf) break;
+                       }
+               }
+       }
+out:
+       // Got it.  Emit changed data.
+       TT.state = "-+"[reverse];
+       TOY_llist_free(TT.plines, do_line);
+       TT.plines = NULL;
+       TT.state = 1;
+done:
+       if (buf) {
+               buf->prev->next = NULL;
+               TOY_llist_free(buf, do_line);
+       }
+
+       return TT.state;
+}
+
+// state 0: Not in a hunk, look for +++.
+// state 1: Found +++ file indicator, look for @@
+// state 2: In hunk: counting initial context lines
+// state 3: In hunk: getting body
+
+int patch_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
+int patch_main(int argc UNUSED_PARAM, char **argv)
+{
+       int opts;
+       int reverse, state = 0;
+       char *oldname = NULL, *newname = NULL;
+       char *opt_p, *opt_i;
+       int prefix;
+
+       long oldline = 0, oldlen = 0, newline = 0, newlen = 0;
+
+       INIT_TT();
+
+       opts = getopt32(argv, FLAG_STR, &opt_p, &opt_i);
+       reverse = opts & FLAG_REVERSE;
+
+       if (opts & FLAG_INPUT) xmove_fd(xopen(opt_i, O_RDONLY), STDIN_FILENO);
+       prefix = (opts & FLAG_PATHLEN) ? xatoi(opt_p) : 0; // can be negative!
+       TT.filein = TT.fileout = -1;
+
+       // Loop through the lines in the patch
+       for(;;) {
+               char *patchline;
+
+               patchline = get_line(STDIN_FILENO);
+               if (!patchline) break;
+
+               // Other versions of patch accept damaged patches,
+               // so we need to also.
+               if (!*patchline) {
+                       free(patchline);
+                       patchline = xstrdup(" ");
+               }
+
+               // Are we assembling a hunk?
+               if (state >= 2) {
+                       if (*patchline==' ' || *patchline=='+' || *patchline=='-') {
+                               dlist_add(&TT.plines, patchline);
+
+                               if (*patchline != '+') oldlen--;
+                               if (*patchline != '-') newlen--;
+
+                               // Context line?
+                               if (*patchline==' ' && state==2) TT.context++;
+                               else state=3;
+
+                               // If we've consumed all expected hunk lines, apply the hunk.
+                               if (!oldlen && !newlen) state = apply_hunk();
+                               continue;
+                       }
+                       fail_hunk();
+                       state = 0;
+                       continue;
+               }
+
+               // Open a new file?
+               if (!strncmp("--- ", patchline, 4) || !strncmp("+++ ", patchline, 4)) {
+                       char *s, **name = &oldname;
+                       int i;
+
+                       if (*patchline == '+') {
+                               name = &newname;
+                               state = 1;
+                       }
+
+                       free(*name);
+                       finish_oldfile();
+
+                       // Trim date from end of filename (if any).  We don't care.
+                       for (s = patchline+4; *s && *s!='\t'; s++)
+                               if (*s=='\\' && s[1]) s++;
+                       i = atoi(s);
+                       if (i && i<=1970)
+                               *name = xstrdup("/dev/null");
+                       else {
+                               *s = 0;
+                               *name = xstrdup(patchline+4);
+                       }
+
+                       // We defer actually opening the file because svn produces broken
+                       // patches that don't signal they want to create a new file the
+                       // way the patch man page says, so you have to read the first hunk
+                       // and _guess_.
+
+               // Start a new hunk?
+               } else if (state == 1 && !strncmp("@@ -", patchline, 4)) {
+                       int i;
+
+                       i = sscanf(patchline+4, "%ld,%ld +%ld,%ld",
+                                       &oldline, &oldlen, &newline, &newlen);
+                       if (i != 4)
+                               bb_error_msg_and_die("corrupt hunk %d at %ld", TT.hunknum, TT.linenum);
+
+                       TT.context = 0;
+                       state = 2;
+
+                       // If this is the first hunk, open the file.
+                       if (TT.filein == -1) {
+                               int oldsum, newsum, del = 0;
+                               char *s, *name;
+
+                               oldsum = oldline + oldlen;
+                               newsum = newline + newlen;
+
+                               name = reverse ? oldname : newname;
+
+                               // We're deleting oldname if new file is /dev/null (before -p)
+                               // or if new hunk is empty (zero context) after patching
+                               if (!strcmp(name, "/dev/null") || !(reverse ? oldsum : newsum)) {
+                                       name = reverse ? newname : oldname;
+                                       del++;
+                               }
+
+                               // handle -p path truncation.
+                               for (i=0, s = name; *s;) {
+                                       if ((option_mask32 & FLAG_PATHLEN) && prefix == i)
+                                               break;
+                                       if (*(s++)=='/') {
+                                               name = s;
+                                               i++;
+                                       }
+                               }
+
+                               if (del) {
+                                       printf("removing %s\n", name);
+                                       xunlink(name);
+                                       state = 0;
+                               // If we've got a file to open, do so.
+                               } else if (!(option_mask32 & FLAG_PATHLEN) || i <= prefix) {
+                                       // If the old file was null, we're creating a new one.
+                                       if (!strcmp(oldname, "/dev/null") || !oldsum) {
+                                               printf("creating %s\n", name);
+                                               s = strrchr(name, '/');
+                                               if (s) {
+                                                       *s = 0;
+                                                       xmkpath(name, -1);
+                                                       *s = '/';
+                                               }
+                                               TT.filein = xopen3(name, O_CREAT|O_EXCL|O_RDWR, 0666);
+                                       } else {
+                                               printf("patching file %s\n", name);
+                                               TT.filein = xopen(name, O_RDWR);
+                                       }
+                                       TT.fileout = copy_tempfile(TT.filein, name, &TT.tempname);
+                                       TT.linenum = 0;
+                                       TT.hunknum = 0;
+                               }
+                       }
+
+                       TT.hunknum++;
+
+                       continue;
+               }
+
+               // If we didn't continue above, discard this line.
+               free(patchline);
+       }
+
+       finish_oldfile();
+
+       if (ENABLE_FEATURE_CLEAN_UP) {
+               free(oldname);
+               free(newname);
+       }
+
+       return TT.exitval;
+}