git/builtin/merge-index.c
Nguyễn Thái Ngọc Duy 9c5e6c802c Convert "struct cache_entry *" to "const ..." wherever possible
I attempted to make index_state->cache[] a "const struct cache_entry **"
to find out how existing entries in index are modified and where. The
question I have is what do we do if we really need to keep track of on-disk
changes in the index. The result is

 - diff-lib.c: setting CE_UPTODATE

 - name-hash.c: setting CE_HASHED

 - preload-index.c, read-cache.c, unpack-trees.c and
   builtin/update-index: obvious

 - entry.c: write_entry() may refresh the checked out entry via
   fill_stat_cache_info(). This causes "non-const struct cache_entry
   *" in builtin/apply.c, builtin/checkout-index.c and
   builtin/checkout.c

 - builtin/ls-files.c: --with-tree changes stagemask and may set
   CE_UPDATE

Of these, write_entry() and its call sites are probably most
interesting because it modifies on-disk info. But this is stat info
and can be retrieved via refresh, at least for porcelain
commands. Other just uses ce_flags for local purposes.

So, keeping track of "dirty" entries is just a matter of setting a
flag in index modification functions exposed by read-cache.c. Except
unpack-trees, the rest of the code base does not do anything funny
behind read-cache's back.

The actual patch is less valueable than the summary above. But if
anyone wants to re-identify the above sites. Applying this patch, then
this:

    diff --git a/cache.h b/cache.h
    index 430d021..1692891 100644
    --- a/cache.h
    +++ b/cache.h
    @@ -267,7 +267,7 @@ static inline unsigned int canon_mode(unsigned int mode)
     #define cache_entry_size(len) (offsetof(struct cache_entry,name) + (len) + 1)

     struct index_state {
    -	struct cache_entry **cache;
    +	const struct cache_entry **cache;
     	unsigned int version;
     	unsigned int cache_nr, cache_alloc, cache_changed;
     	struct string_list *resolve_undo;

will help quickly identify them without bogus warnings.

Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-07-09 09:12:48 -07:00

110 lines
2.2 KiB
C

#include "builtin.h"
#include "run-command.h"
static const char *pgm;
static int one_shot, quiet;
static int err;
static int merge_entry(int pos, const char *path)
{
int found;
const char *arguments[] = { pgm, "", "", "", path, "", "", "", NULL };
char hexbuf[4][60];
char ownbuf[4][60];
if (pos >= active_nr)
die("git merge-index: %s not in the cache", path);
found = 0;
do {
const struct cache_entry *ce = active_cache[pos];
int stage = ce_stage(ce);
if (strcmp(ce->name, path))
break;
found++;
strcpy(hexbuf[stage], sha1_to_hex(ce->sha1));
sprintf(ownbuf[stage], "%o", ce->ce_mode);
arguments[stage] = hexbuf[stage];
arguments[stage + 4] = ownbuf[stage];
} while (++pos < active_nr);
if (!found)
die("git merge-index: %s not in the cache", path);
if (run_command_v_opt(arguments, 0)) {
if (one_shot)
err++;
else {
if (!quiet)
die("merge program failed");
exit(1);
}
}
return found;
}
static void merge_one_path(const char *path)
{
int pos = cache_name_pos(path, strlen(path));
/*
* If it already exists in the cache as stage0, it's
* already merged and there is nothing to do.
*/
if (pos < 0)
merge_entry(-pos-1, path);
}
static void merge_all(void)
{
int i;
for (i = 0; i < active_nr; i++) {
const struct cache_entry *ce = active_cache[i];
if (!ce_stage(ce))
continue;
i += merge_entry(i, ce->name)-1;
}
}
int cmd_merge_index(int argc, const char **argv, const char *prefix)
{
int i, force_file = 0;
/* Without this we cannot rely on waitpid() to tell
* what happened to our children.
*/
signal(SIGCHLD, SIG_DFL);
if (argc < 3)
usage("git merge-index [-o] [-q] <merge-program> (-a | [--] <filename>*)");
read_cache();
i = 1;
if (!strcmp(argv[i], "-o")) {
one_shot = 1;
i++;
}
if (!strcmp(argv[i], "-q")) {
quiet = 1;
i++;
}
pgm = argv[i++];
for (; i < argc; i++) {
const char *arg = argv[i];
if (!force_file && *arg == '-') {
if (!strcmp(arg, "--")) {
force_file = 1;
continue;
}
if (!strcmp(arg, "-a")) {
merge_all();
continue;
}
die("git merge-index: unknown option %s", arg);
}
merge_one_path(arg);
}
if (err && !quiet)
die("merge program failed");
return err;
}