git/sha1_name.c
Junio C Hamano 84a9b58c42 sha1_name: warning ambiguous refs.
This makes sure that many commands that take refs on the command
line to honor core.warnambiguousrefs configuration.  Earlier,
the commands affected by this patch did not read the
configuration file.

Signed-off-by: Junio C Hamano <junkio@cox.net>
2006-03-23 23:41:18 -08:00

460 lines
10 KiB
C

#include "cache.h"
#include "tag.h"
#include "commit.h"
#include "tree.h"
#include "blob.h"
static int find_short_object_filename(int len, const char *name, unsigned char *sha1)
{
struct alternate_object_database *alt;
char hex[40];
int found = 0;
static struct alternate_object_database *fakeent;
if (!fakeent) {
const char *objdir = get_object_directory();
int objdir_len = strlen(objdir);
int entlen = objdir_len + 43;
fakeent = xmalloc(sizeof(*fakeent) + entlen);
memcpy(fakeent->base, objdir, objdir_len);
fakeent->name = fakeent->base + objdir_len + 1;
fakeent->name[-1] = '/';
}
fakeent->next = alt_odb_list;
sprintf(hex, "%.2s", name);
for (alt = fakeent; alt && found < 2; alt = alt->next) {
struct dirent *de;
DIR *dir;
sprintf(alt->name, "%.2s/", name);
dir = opendir(alt->base);
if (!dir)
continue;
while ((de = readdir(dir)) != NULL) {
if (strlen(de->d_name) != 38)
continue;
if (memcmp(de->d_name, name + 2, len - 2))
continue;
if (!found) {
memcpy(hex + 2, de->d_name, 38);
found++;
}
else if (memcmp(hex + 2, de->d_name, 38)) {
found = 2;
break;
}
}
closedir(dir);
}
if (found == 1)
return get_sha1_hex(hex, sha1) == 0;
return found;
}
static int match_sha(unsigned len, const unsigned char *a, const unsigned char *b)
{
do {
if (*a != *b)
return 0;
a++;
b++;
len -= 2;
} while (len > 1);
if (len)
if ((*a ^ *b) & 0xf0)
return 0;
return 1;
}
static int find_short_packed_object(int len, const unsigned char *match, unsigned char *sha1)
{
struct packed_git *p;
unsigned char found_sha1[20];
int found = 0;
prepare_packed_git();
for (p = packed_git; p && found < 2; p = p->next) {
unsigned num = num_packed_objects(p);
unsigned first = 0, last = num;
while (first < last) {
unsigned mid = (first + last) / 2;
unsigned char now[20];
int cmp;
nth_packed_object_sha1(p, mid, now);
cmp = memcmp(match, now, 20);
if (!cmp) {
first = mid;
break;
}
if (cmp > 0) {
first = mid+1;
continue;
}
last = mid;
}
if (first < num) {
unsigned char now[20], next[20];
nth_packed_object_sha1(p, first, now);
if (match_sha(len, match, now)) {
if (nth_packed_object_sha1(p, first+1, next) ||
!match_sha(len, match, next)) {
/* unique within this pack */
if (!found) {
memcpy(found_sha1, now, 20);
found++;
}
else if (memcmp(found_sha1, now, 20)) {
found = 2;
break;
}
}
else {
/* not even unique within this pack */
found = 2;
break;
}
}
}
}
if (found == 1)
memcpy(sha1, found_sha1, 20);
return found;
}
#define SHORT_NAME_NOT_FOUND (-1)
#define SHORT_NAME_AMBIGUOUS (-2)
static int find_unique_short_object(int len, char *canonical,
unsigned char *res, unsigned char *sha1)
{
int has_unpacked, has_packed;
unsigned char unpacked_sha1[20], packed_sha1[20];
has_unpacked = find_short_object_filename(len, canonical, unpacked_sha1);
has_packed = find_short_packed_object(len, res, packed_sha1);
if (!has_unpacked && !has_packed)
return SHORT_NAME_NOT_FOUND;
if (1 < has_unpacked || 1 < has_packed)
return SHORT_NAME_AMBIGUOUS;
if (has_unpacked != has_packed) {
memcpy(sha1, (has_packed ? packed_sha1 : unpacked_sha1), 20);
return 0;
}
/* Both have unique ones -- do they match? */
if (memcmp(packed_sha1, unpacked_sha1, 20))
return SHORT_NAME_AMBIGUOUS;
memcpy(sha1, packed_sha1, 20);
return 0;
}
static int get_short_sha1(const char *name, int len, unsigned char *sha1,
int quietly)
{
int i, status;
char canonical[40];
unsigned char res[20];
if (len < MINIMUM_ABBREV)
return -1;
memset(res, 0, 20);
memset(canonical, 'x', 40);
for (i = 0; i < len ;i++) {
unsigned char c = name[i];
unsigned char val;
if (c >= '0' && c <= '9')
val = c - '0';
else if (c >= 'a' && c <= 'f')
val = c - 'a' + 10;
else if (c >= 'A' && c <='F') {
val = c - 'A' + 10;
c -= 'A' - 'a';
}
else
return -1;
canonical[i] = c;
if (!(i & 1))
val <<= 4;
res[i >> 1] |= val;
}
status = find_unique_short_object(i, canonical, res, sha1);
if (!quietly && (status == SHORT_NAME_AMBIGUOUS))
return error("short SHA1 %.*s is ambiguous.", len, canonical);
return status;
}
const char *find_unique_abbrev(const unsigned char *sha1, int len)
{
int status, is_null;
static char hex[41];
is_null = !memcmp(sha1, null_sha1, 20);
memcpy(hex, sha1_to_hex(sha1), 40);
if (len == 40)
return hex;
while (len < 40) {
unsigned char sha1_ret[20];
status = get_short_sha1(hex, len, sha1_ret, 1);
if (!status ||
(is_null && status != SHORT_NAME_AMBIGUOUS)) {
hex[len] = 0;
return hex;
}
if (status != SHORT_NAME_AMBIGUOUS)
return NULL;
len++;
}
return NULL;
}
static int ambiguous_path(const char *path, int len)
{
int slash = 1;
int cnt;
for (cnt = 0; cnt < len; cnt++) {
switch (*path++) {
case '\0':
break;
case '/':
if (slash)
break;
slash = 1;
continue;
case '.':
continue;
default:
slash = 0;
continue;
}
break;
}
return slash;
}
static int get_sha1_basic(const char *str, int len, unsigned char *sha1)
{
static const char *fmt[] = {
"%.*s",
"refs/%.*s",
"refs/tags/%.*s",
"refs/heads/%.*s",
"refs/remotes/%.*s",
"refs/remotes/%.*s/HEAD",
NULL
};
const char **p;
const char *warning = "warning: refname '%.*s' is ambiguous.\n";
char *pathname;
int already_found = 0;
unsigned char *this_result;
unsigned char sha1_from_ref[20];
if (len == 40 && !get_sha1_hex(str, sha1))
return 0;
/* Accept only unambiguous ref paths. */
if (ambiguous_path(str, len))
return -1;
for (p = fmt; *p; p++) {
this_result = already_found ? sha1_from_ref : sha1;
pathname = git_path(*p, len, str);
if (!read_ref(pathname, this_result)) {
if (warn_ambiguous_refs) {
if (already_found)
fprintf(stderr, warning, len, str);
already_found++;
}
else
return 0;
}
}
if (already_found)
return 0;
return -1;
}
static int get_sha1_1(const char *name, int len, unsigned char *sha1);
static int get_parent(const char *name, int len,
unsigned char *result, int idx)
{
unsigned char sha1[20];
int ret = get_sha1_1(name, len, sha1);
struct commit *commit;
struct commit_list *p;
if (ret)
return ret;
commit = lookup_commit_reference(sha1);
if (!commit)
return -1;
if (parse_commit(commit))
return -1;
if (!idx) {
memcpy(result, commit->object.sha1, 20);
return 0;
}
p = commit->parents;
while (p) {
if (!--idx) {
memcpy(result, p->item->object.sha1, 20);
return 0;
}
p = p->next;
}
return -1;
}
static int get_nth_ancestor(const char *name, int len,
unsigned char *result, int generation)
{
unsigned char sha1[20];
int ret = get_sha1_1(name, len, sha1);
if (ret)
return ret;
while (generation--) {
struct commit *commit = lookup_commit_reference(sha1);
if (!commit || parse_commit(commit) || !commit->parents)
return -1;
memcpy(sha1, commit->parents->item->object.sha1, 20);
}
memcpy(result, sha1, 20);
return 0;
}
static int peel_onion(const char *name, int len, unsigned char *sha1)
{
unsigned char outer[20];
const char *sp;
const char *type_string = NULL;
struct object *o;
/*
* "ref^{type}" dereferences ref repeatedly until you cannot
* dereference anymore, or you get an object of given type,
* whichever comes first. "ref^{}" means just dereference
* tags until you get a non-tag. "ref^0" is a shorthand for
* "ref^{commit}". "commit^{tree}" could be used to find the
* top-level tree of the given commit.
*/
if (len < 4 || name[len-1] != '}')
return -1;
for (sp = name + len - 1; name <= sp; sp--) {
int ch = *sp;
if (ch == '{' && name < sp && sp[-1] == '^')
break;
}
if (sp <= name)
return -1;
sp++; /* beginning of type name, or closing brace for empty */
if (!strncmp(commit_type, sp, 6) && sp[6] == '}')
type_string = commit_type;
else if (!strncmp(tree_type, sp, 4) && sp[4] == '}')
type_string = tree_type;
else if (!strncmp(blob_type, sp, 4) && sp[4] == '}')
type_string = blob_type;
else if (sp[0] == '}')
type_string = NULL;
else
return -1;
if (get_sha1_1(name, sp - name - 2, outer))
return -1;
o = parse_object(outer);
if (!o)
return -1;
if (!type_string) {
o = deref_tag(o, name, sp - name - 2);
if (!o || (!o->parsed && !parse_object(o->sha1)))
return -1;
memcpy(sha1, o->sha1, 20);
}
else {
/* At this point, the syntax look correct, so
* if we do not get the needed object, we should
* barf.
*/
while (1) {
if (!o || (!o->parsed && !parse_object(o->sha1)))
return -1;
if (o->type == type_string) {
memcpy(sha1, o->sha1, 20);
return 0;
}
if (o->type == tag_type)
o = ((struct tag*) o)->tagged;
else if (o->type == commit_type)
o = &(((struct commit *) o)->tree->object);
else
return error("%.*s: expected %s type, but the object dereferences to %s type",
len, name, type_string,
o->type);
if (!o->parsed)
parse_object(o->sha1);
}
}
return 0;
}
static int get_sha1_1(const char *name, int len, unsigned char *sha1)
{
int ret, has_suffix;
const char *cp;
/* "name~3" is "name^^^",
* "name~" and "name~0" are name -- not "name^0"!
* "name^" is not "name^0"; it is "name^1".
*/
has_suffix = 0;
for (cp = name + len - 1; name <= cp; cp--) {
int ch = *cp;
if ('0' <= ch && ch <= '9')
continue;
if (ch == '~' || ch == '^')
has_suffix = ch;
break;
}
if (has_suffix) {
int num = 0;
int len1 = cp - name;
cp++;
while (cp < name + len)
num = num * 10 + *cp++ - '0';
if (has_suffix == '^') {
if (!num && len1 == len - 1)
num = 1;
return get_parent(name, len1, sha1, num);
}
/* else if (has_suffix == '~') -- goes without saying */
return get_nth_ancestor(name, len1, sha1, num);
}
ret = peel_onion(name, len, sha1);
if (!ret)
return 0;
ret = get_sha1_basic(name, len, sha1);
if (!ret)
return 0;
return get_short_sha1(name, len, sha1, 0);
}
/*
* This is like "get_sha1_basic()", except it allows "sha1 expressions",
* notably "xyz^" for "parent of xyz"
*/
int get_sha1(const char *name, unsigned char *sha1)
{
prepare_alt_odb();
return get_sha1_1(name, strlen(name), sha1);
}