/* patch.c - Apply a "universal" diff.
*
* Copyright 2007 Rob Landley <rob@landley.net>
*
* see http://opengroup.org/onlinepubs/9699919799/utilities/patch.html
* (But only does -u, because who still cares about "ed"?)
*
* TODO:
* -b backup
* -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, "(dry-run)"USE_TOYBOX_DEBUG("x")"ulp#d:i:Rs(quiet)", TOYFLAG_USR|TOYFLAG_BIN))
config PATCH
bool "patch"
default y
help
usage: patch [-d DIR] [-i file] [-p depth] [-Rlsu] [--dry-run]
Apply a unified diff to one or more files.
-d Modify files in DIR
-i Input file (default=stdin)
-l Loose match (ignore whitespace)
-p Number of '/' to strip from start of file paths (default=all)
-R Reverse patch
-s Silent except for errors
-u Ignored (only handles "unified" diffs)
--dry-run Don't change files, just confirm patch applies
This version of patch only handles unified diffs, and only modifies
a file when 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.
*/
#define FOR_patch
#include "toys.h"
GLOBALS(
char *i, *d;
long p;
struct double_list *current_hunk;
long oldline, oldlen, newline, newlen;
long linenum;
int context, state, filein, fileout, filepatch, hunknum;
char *tempname;
)
// 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) {
char *s = dlist->data+(TT.state>3);
int i = TT.state == 2 ? 2 : TT.fileout;
xwrite(i, s, strlen(s));
xwrite(i, "\n", 1);
}
if (FLAG(x)) fprintf(stderr, "DO %d: %s\n", TT.state, dlist->data);
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.current_hunk) return;
fprintf(stderr, "Hunk %d FAILED %ld/%ld.\n",
TT.hunknum, TT.oldline, TT.newline);
toys.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;
llist_traverse(TT.current_hunk, do_line);
TT.current_hunk = NULL;
if (!FLAG(dry_run)) delete_tempfile(TT.filein, TT.fileout, &TT.tempname);
TT.state = 0;
}
// Compare ignoring whitespace. Just returns 0/1, no > or <
static int loosecmp(char *aa, char *bb)
{
int a = 0, b = 0;
for (;;) {
while (isspace(aa[a])) a++;
while (isspace(bb[b])) b++;
if (aa[a] != bb[b]) return 1;
if (!aa[a]) return 0;
a++, b++;
}
}
// Given a hunk of a unified diff, make the appropriate change to the file.
// This does not use the location information, but instead treats a hunk
// as a sort of regex. Copies data from input to output until it finds
// the change to be made, then outputs the changed data and returns.
// (Finding EOF first is an error.) This is a single pass operation, so
// multiple hunks must occur in order in the file.
static int apply_one_hunk(void)
{
struct double_list *plist, *buf = NULL, *check;
int matcheof, trailing = 0, reverse = FLAG(R), backwarn = 0;
int (*lcmp)(char *aa, char *bb);
lcmp = FLAG(l) ? (void *)loosecmp : (void *)strcmp;
dlist_terminate(TT.current_hunk);
// Match EOF if there aren't as many ending context lines as beginning
for (plist = TT.current_hunk; plist; plist = plist->next) {
if (plist->data[0]==' ') trailing++;
else trailing = 0;
if (FLAG(x)) fprintf(stderr, "HUNK:%s\n", plist->data);
}
matcheof = !trailing || trailing < TT.context;
if (FLAG(x)) fprintf(stderr,"MATCHEOF=%c\n", matcheof ? 'Y' : 'N');
// Loop through input data searching for this hunk. Match all context
// lines and all lines to be removed until we've found the end of a
// complete hunk.
plist = TT.current_hunk;
buf = NULL;
for (;;) {
char *data = get_line(TT.filein);
TT.linenum++;
// Figure out which line of hunk to compare with next. (Skip lines
// of the hunk we'd be adding.)
while (plist && *plist->data == "+-"[reverse]) {
if (data && !lcmp(data, plist->data+1))
if (!backwarn) backwarn = TT.linenum;
plist = plist->next;
}
// Is this EOF?
if (!data) {
if (FLAG(x)) fprintf(stderr, "INEOF\n");
// Does this hunk need to match EOF?
if (!plist && matcheof) break;
if (backwarn && !FLAG(s))
fprintf(stderr, "Possibly reversed hunk %d at %ld\n",
TT.hunknum, TT.linenum);
// File ended before we found a place for this hunk.
fail_hunk();
goto done;
} else if (FLAG(x)) fprintf(stderr, "IN: %s\n", data);
check = dlist_add(&buf, data);
// Compare this line with next expected line of hunk.
// A match can fail because the next line doesn't match, or because
// we hit the end of a hunk that needed EOF, and this isn't EOF.
// If match failed, flush first line of buffered data and
// recheck buffered data for a new match until we find one or run
// out of buffer.
for (;;) {
if (!plist || lcmp(check->data, plist->data+1)) {
// Match failed. Write out first line of buffered data and
// recheck remaining buffered data for a new match.
if (FLAG(x)) {
int bug = 0;
if (!plist) fprintf(stderr, "NULL plist\n");
else {
while (plist->data[bug] == check->data[bug]) bug++;
fprintf(stderr, "NOT(%d:%d!=%d): %s\n", bug, plist->data[bug],
check->data[bug], plist->data);
}
}
// If this hunk must match start of file, fail if it didn't.
if (!TT.context || trailing>TT.context) {
fail_hunk();
goto done;
}
TT.state = 3;
do_line(check = dlist_pop(&buf));
plist = TT.current_hunk;
// If we've reached the end of the buffer without confirming a
// match, read more lines.
if (!buf) break;
check = buf;
} else {
if (FLAG(x)) fprintf(stderr, "MAYBE: %s\n", plist->data);
// This line matches. Advance plist, detect successful match.
plist = plist->next;
if (!plist && !matcheof) goto out;
check = check->next;
if (check == buf) break;
}
}
}
out:
// We have a match. Emit changed data.
TT.state = "-+"[reverse];
llist_traverse(TT.current_hunk, do_line);
TT.current_hunk = NULL;
TT.state = 1;
done:
if (buf) {
dlist_terminate(buf);
llist_traverse(buf, do_line);
}
return TT.state;
}
// Read a patch file and find hunks, opening/creating/deleting files.
// Call apply_one_hunk() on each hunk.
// 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
void patch_main(void)
{
int reverse = FLAG(R), state = 0, patchlinenum = 0, strip = 0;
char *oldname = NULL, *newname = NULL;
if (TT.i) TT.filepatch = xopenro(TT.i);
TT.filein = TT.fileout = -1;
if (TT.d) xchdir(TT.d);
// Loop through the lines in the patch
for (;;) {
char *patchline;
patchline = get_line(TT.filepatch);
if (!patchline) break;
// Other versions of patch accept damaged patches, so we need to also.
if (strip || !patchlinenum++) {
int len = strlen(patchline);
if (patchline[len-1] == '\r') {
if (!strip && !FLAG(s)) fprintf(stderr, "Removing DOS newlines\n");
strip = 1;
patchline[len-1]=0;
}
}
if (!*patchline) {
free(patchline);
patchline = xstrdup(" ");
}
// Are we assembling a hunk?
if (state >= 2) {
if (*patchline==' ' || *patchline=='+' || *patchline=='-') {
dlist_add(&TT.current_hunk, patchline);
if (*patchline != '+') TT.oldlen--;
if (*patchline != '-') TT.newlen--;
// Context line?
if (*patchline==' ' && state==2) TT.context++;
else state=3;
// If we've consumed all expected hunk lines, apply the hunk.
if (!TT.oldlen && !TT.newlen) state = apply_one_hunk();
continue;
}
dlist_terminate(TT.current_hunk);
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' || !isdigit(s[1])); s++)
if (*s=='\\' && s[1]) s++;
i = atoi(s);
if (i>1900 && 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? Usually @@ -oldline,oldlen +newline,newlen @@
// but a missing ,value means the value is 1.
} else if (state == 1 && !strncmp("@@ -", patchline, 4)) {
int i;
char *s = patchline+4;
// Read oldline[,oldlen] +newline[,newlen]
TT.oldlen = TT.newlen = 1;
TT.oldline = strtol(s, &s, 10);
if (*s == ',') TT.oldlen=strtol(s+1, &s, 10);
TT.newline = strtol(s+2, &s, 10);
if (*s == ',') TT.newlen = strtol(s+1, &s, 10);
TT.context = 0;
state = 2;
// If this is the first hunk, open the file.
if (TT.filein == -1) {
int oldsum, newsum, del = 0;
char *name;
oldsum = TT.oldline + TT.oldlen;
newsum = TT.newline + TT.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 (FLAG(p) && TT.p == i) break;
if (*s++ != '/') continue;
while (*s == '/') s++;
name = s;
i++;
}
if (del) {
if (!FLAG(s)) printf("removing %s\n", name);
xunlink(name);
state = 0;
// If we've got a file to open, do so.
} else if (!FLAG(p) || i <= TT.p) {
// If the old file was null, we're creating a new one.
if ((!strcmp(oldname, "/dev/null") || !oldsum) && access(name, F_OK))
{
if (!FLAG(s)) printf("creating %s\n", name);
if (mkpath(name)) perror_exit("mkpath %s", name);
TT.filein = xcreate(name, O_CREAT|O_EXCL|O_RDWR, 0666);
} else {
if (!FLAG(s)) printf("patching %s\n", name);
TT.filein = xopenro(name);
}
if (FLAG(dry_run)) TT.fileout = xopen("/dev/null", O_RDWR);
else 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 (CFG_TOYBOX_FREE) {
close(TT.filepatch);
free(oldname);
free(newname);
}
}