git/sha1_name.c
Junio C Hamano 0a8cb03555 Merge branch 'br/sha1-name-40-hex-no-disambiguation'
When parsing a 40-hex string into the object name, the string is
checked to see if it can be interpreted as a ref so that a warning
can be given for ambiguity. The code kicked in even when the
core.warnambiguousrefs is set to false to squelch this warning, in
which case the cycles spent to look at the ref namespace were an
expensive no-op, as the result was discarded without being used.

* br/sha1-name-40-hex-no-disambiguation:
  sha1_name: don't resolve refs when core.warnambiguousrefs is false
2014-01-13 11:33:29 -08:00

1452 lines
35 KiB
C

#include "cache.h"
#include "tag.h"
#include "commit.h"
#include "tree.h"
#include "blob.h"
#include "tree-walk.h"
#include "refs.h"
#include "remote.h"
static int get_sha1_oneline(const char *, unsigned char *, struct commit_list *);
typedef int (*disambiguate_hint_fn)(const unsigned char *, void *);
struct disambiguate_state {
disambiguate_hint_fn fn;
void *cb_data;
unsigned char candidate[20];
unsigned candidate_exists:1;
unsigned candidate_checked:1;
unsigned candidate_ok:1;
unsigned disambiguate_fn_used:1;
unsigned ambiguous:1;
unsigned always_call_fn:1;
};
static void update_candidates(struct disambiguate_state *ds, const unsigned char *current)
{
if (ds->always_call_fn) {
ds->ambiguous = ds->fn(current, ds->cb_data) ? 1 : 0;
return;
}
if (!ds->candidate_exists) {
/* this is the first candidate */
hashcpy(ds->candidate, current);
ds->candidate_exists = 1;
return;
} else if (!hashcmp(ds->candidate, current)) {
/* the same as what we already have seen */
return;
}
if (!ds->fn) {
/* cannot disambiguate between ds->candidate and current */
ds->ambiguous = 1;
return;
}
if (!ds->candidate_checked) {
ds->candidate_ok = ds->fn(ds->candidate, ds->cb_data);
ds->disambiguate_fn_used = 1;
ds->candidate_checked = 1;
}
if (!ds->candidate_ok) {
/* discard the candidate; we know it does not satisfy fn */
hashcpy(ds->candidate, current);
ds->candidate_checked = 0;
return;
}
/* if we reach this point, we know ds->candidate satisfies fn */
if (ds->fn(current, ds->cb_data)) {
/*
* if both current and candidate satisfy fn, we cannot
* disambiguate.
*/
ds->candidate_ok = 0;
ds->ambiguous = 1;
}
/* otherwise, current can be discarded and candidate is still good */
}
static void find_short_object_filename(int len, const char *hex_pfx, struct disambiguate_state *ds)
{
struct alternate_object_database *alt;
char hex[40];
static struct alternate_object_database *fakeent;
if (!fakeent) {
/*
* Create a "fake" alternate object database that
* points to our own object database, to make it
* easier to get a temporary working space in
* alt->name/alt->base while iterating over the
* object databases including our own.
*/
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", hex_pfx);
for (alt = fakeent; alt && !ds->ambiguous; alt = alt->next) {
struct dirent *de;
DIR *dir;
sprintf(alt->name, "%.2s/", hex_pfx);
dir = opendir(alt->base);
if (!dir)
continue;
while (!ds->ambiguous && (de = readdir(dir)) != NULL) {
unsigned char sha1[20];
if (strlen(de->d_name) != 38)
continue;
if (memcmp(de->d_name, hex_pfx + 2, len - 2))
continue;
memcpy(hex + 2, de->d_name, 38);
if (!get_sha1_hex(hex, sha1))
update_candidates(ds, sha1);
}
closedir(dir);
}
}
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 void unique_in_pack(int len,
const unsigned char *bin_pfx,
struct packed_git *p,
struct disambiguate_state *ds)
{
uint32_t num, last, i, first = 0;
const unsigned char *current = NULL;
open_pack_index(p);
num = p->num_objects;
last = num;
while (first < last) {
uint32_t mid = (first + last) / 2;
const unsigned char *current;
int cmp;
current = nth_packed_object_sha1(p, mid);
cmp = hashcmp(bin_pfx, current);
if (!cmp) {
first = mid;
break;
}
if (cmp > 0) {
first = mid+1;
continue;
}
last = mid;
}
/*
* At this point, "first" is the location of the lowest object
* with an object name that could match "bin_pfx". See if we have
* 0, 1 or more objects that actually match(es).
*/
for (i = first; i < num && !ds->ambiguous; i++) {
current = nth_packed_object_sha1(p, i);
if (!match_sha(len, bin_pfx, current))
break;
update_candidates(ds, current);
}
}
static void find_short_packed_object(int len, const unsigned char *bin_pfx,
struct disambiguate_state *ds)
{
struct packed_git *p;
prepare_packed_git();
for (p = packed_git; p && !ds->ambiguous; p = p->next)
unique_in_pack(len, bin_pfx, p, ds);
}
#define SHORT_NAME_NOT_FOUND (-1)
#define SHORT_NAME_AMBIGUOUS (-2)
static int finish_object_disambiguation(struct disambiguate_state *ds,
unsigned char *sha1)
{
if (ds->ambiguous)
return SHORT_NAME_AMBIGUOUS;
if (!ds->candidate_exists)
return SHORT_NAME_NOT_FOUND;
if (!ds->candidate_checked)
/*
* If this is the only candidate, there is no point
* calling the disambiguation hint callback.
*
* On the other hand, if the current candidate
* replaced an earlier candidate that did _not_ pass
* the disambiguation hint callback, then we do have
* more than one objects that match the short name
* given, so we should make sure this one matches;
* otherwise, if we discovered this one and the one
* that we previously discarded in the reverse order,
* we would end up showing different results in the
* same repository!
*/
ds->candidate_ok = (!ds->disambiguate_fn_used ||
ds->fn(ds->candidate, ds->cb_data));
if (!ds->candidate_ok)
return SHORT_NAME_AMBIGUOUS;
hashcpy(sha1, ds->candidate);
return 0;
}
static int disambiguate_commit_only(const unsigned char *sha1, void *cb_data_unused)
{
int kind = sha1_object_info(sha1, NULL);
return kind == OBJ_COMMIT;
}
static int disambiguate_committish_only(const unsigned char *sha1, void *cb_data_unused)
{
struct object *obj;
int kind;
kind = sha1_object_info(sha1, NULL);
if (kind == OBJ_COMMIT)
return 1;
if (kind != OBJ_TAG)
return 0;
/* We need to do this the hard way... */
obj = deref_tag(parse_object(sha1), NULL, 0);
if (obj && obj->type == OBJ_COMMIT)
return 1;
return 0;
}
static int disambiguate_tree_only(const unsigned char *sha1, void *cb_data_unused)
{
int kind = sha1_object_info(sha1, NULL);
return kind == OBJ_TREE;
}
static int disambiguate_treeish_only(const unsigned char *sha1, void *cb_data_unused)
{
struct object *obj;
int kind;
kind = sha1_object_info(sha1, NULL);
if (kind == OBJ_TREE || kind == OBJ_COMMIT)
return 1;
if (kind != OBJ_TAG)
return 0;
/* We need to do this the hard way... */
obj = deref_tag(lookup_object(sha1), NULL, 0);
if (obj && (obj->type == OBJ_TREE || obj->type == OBJ_COMMIT))
return 1;
return 0;
}
static int disambiguate_blob_only(const unsigned char *sha1, void *cb_data_unused)
{
int kind = sha1_object_info(sha1, NULL);
return kind == OBJ_BLOB;
}
static int prepare_prefixes(const char *name, int len,
unsigned char *bin_pfx,
char *hex_pfx)
{
int i;
hashclr(bin_pfx);
memset(hex_pfx, '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;
hex_pfx[i] = c;
if (!(i & 1))
val <<= 4;
bin_pfx[i >> 1] |= val;
}
return 0;
}
static int get_short_sha1(const char *name, int len, unsigned char *sha1,
unsigned flags)
{
int status;
char hex_pfx[40];
unsigned char bin_pfx[20];
struct disambiguate_state ds;
int quietly = !!(flags & GET_SHA1_QUIETLY);
if (len < MINIMUM_ABBREV || len > 40)
return -1;
if (prepare_prefixes(name, len, bin_pfx, hex_pfx) < 0)
return -1;
prepare_alt_odb();
memset(&ds, 0, sizeof(ds));
if (flags & GET_SHA1_COMMIT)
ds.fn = disambiguate_commit_only;
else if (flags & GET_SHA1_COMMITTISH)
ds.fn = disambiguate_committish_only;
else if (flags & GET_SHA1_TREE)
ds.fn = disambiguate_tree_only;
else if (flags & GET_SHA1_TREEISH)
ds.fn = disambiguate_treeish_only;
else if (flags & GET_SHA1_BLOB)
ds.fn = disambiguate_blob_only;
find_short_object_filename(len, hex_pfx, &ds);
find_short_packed_object(len, bin_pfx, &ds);
status = finish_object_disambiguation(&ds, sha1);
if (!quietly && (status == SHORT_NAME_AMBIGUOUS))
return error("short SHA1 %.*s is ambiguous.", len, hex_pfx);
return status;
}
int for_each_abbrev(const char *prefix, each_abbrev_fn fn, void *cb_data)
{
char hex_pfx[40];
unsigned char bin_pfx[20];
struct disambiguate_state ds;
int len = strlen(prefix);
if (len < MINIMUM_ABBREV || len > 40)
return -1;
if (prepare_prefixes(prefix, len, bin_pfx, hex_pfx) < 0)
return -1;
prepare_alt_odb();
memset(&ds, 0, sizeof(ds));
ds.always_call_fn = 1;
ds.cb_data = cb_data;
ds.fn = fn;
find_short_object_filename(len, hex_pfx, &ds);
find_short_packed_object(len, bin_pfx, &ds);
return ds.ambiguous;
}
const char *find_unique_abbrev(const unsigned char *sha1, int len)
{
int status, exists;
static char hex[41];
exists = has_sha1_file(sha1);
memcpy(hex, sha1_to_hex(sha1), 40);
if (len == 40 || !len)
return hex;
while (len < 40) {
unsigned char sha1_ret[20];
status = get_short_sha1(hex, len, sha1_ret, GET_SHA1_QUIETLY);
if (exists
? !status
: status == SHORT_NAME_NOT_FOUND) {
hex[len] = 0;
return hex;
}
len++;
}
return hex;
}
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 inline int upstream_mark(const char *string, int len)
{
const char *suffix[] = { "@{upstream}", "@{u}" };
int i;
for (i = 0; i < ARRAY_SIZE(suffix); i++) {
int suffix_len = strlen(suffix[i]);
if (suffix_len <= len
&& !memcmp(string, suffix[i], suffix_len))
return suffix_len;
}
return 0;
}
static int get_sha1_1(const char *name, int len, unsigned char *sha1, unsigned lookup_flags);
static int interpret_nth_prior_checkout(const char *name, struct strbuf *buf);
static int get_sha1_basic(const char *str, int len, unsigned char *sha1)
{
static const char *warn_msg = "refname '%.*s' is ambiguous.";
static const char *object_name_msg = N_(
"Git normally never creates a ref that ends with 40 hex characters\n"
"because it will be ignored when you just specify 40-hex. These refs\n"
"may be created by mistake. For example,\n"
"\n"
" git checkout -b $br $(git rev-parse ...)\n"
"\n"
"where \"$br\" is somehow empty and a 40-hex ref is created. Please\n"
"examine these refs and maybe delete them. Turn this message off by\n"
"running \"git config advice.objectNameWarning false\"");
unsigned char tmp_sha1[20];
char *real_ref = NULL;
int refs_found = 0;
int at, reflog_len, nth_prior = 0;
if (len == 40 && !get_sha1_hex(str, sha1)) {
if (warn_ambiguous_refs && warn_on_object_refname_ambiguity) {
refs_found = dwim_ref(str, len, tmp_sha1, &real_ref);
if (refs_found > 0) {
warning(warn_msg, len, str);
if (advice_object_name_warning)
fprintf(stderr, "%s\n", _(object_name_msg));
}
free(real_ref);
}
return 0;
}
/* basic@{time or number or -number} format to query ref-log */
reflog_len = at = 0;
if (len && str[len-1] == '}') {
for (at = len-4; at >= 0; at--) {
if (str[at] == '@' && str[at+1] == '{') {
if (str[at+2] == '-') {
if (at != 0)
/* @{-N} not at start */
return -1;
nth_prior = 1;
continue;
}
if (!upstream_mark(str + at, len - at)) {
reflog_len = (len-1) - (at+2);
len = at;
}
break;
}
}
}
/* Accept only unambiguous ref paths. */
if (len && ambiguous_path(str, len))
return -1;
if (nth_prior) {
struct strbuf buf = STRBUF_INIT;
int detached;
if (interpret_nth_prior_checkout(str, &buf) > 0) {
detached = (buf.len == 40 && !get_sha1_hex(buf.buf, sha1));
strbuf_release(&buf);
if (detached)
return 0;
}
}
if (!len && reflog_len)
/* allow "@{...}" to mean the current branch reflog */
refs_found = dwim_ref("HEAD", 4, sha1, &real_ref);
else if (reflog_len)
refs_found = dwim_log(str, len, sha1, &real_ref);
else
refs_found = dwim_ref(str, len, sha1, &real_ref);
if (!refs_found)
return -1;
if (warn_ambiguous_refs &&
(refs_found > 1 ||
!get_short_sha1(str, len, tmp_sha1, GET_SHA1_QUIETLY)))
warning(warn_msg, len, str);
if (reflog_len) {
int nth, i;
unsigned long at_time;
unsigned long co_time;
int co_tz, co_cnt;
/* Is it asking for N-th entry, or approxidate? */
for (i = nth = 0; 0 <= nth && i < reflog_len; i++) {
char ch = str[at+2+i];
if ('0' <= ch && ch <= '9')
nth = nth * 10 + ch - '0';
else
nth = -1;
}
if (100000000 <= nth) {
at_time = nth;
nth = -1;
} else if (0 <= nth)
at_time = 0;
else {
int errors = 0;
char *tmp = xstrndup(str + at + 2, reflog_len);
at_time = approxidate_careful(tmp, &errors);
free(tmp);
if (errors)
return -1;
}
if (read_ref_at(real_ref, at_time, nth, sha1, NULL,
&co_time, &co_tz, &co_cnt)) {
if (!len) {
if (starts_with(real_ref, "refs/heads/")) {
str = real_ref + 11;
len = strlen(real_ref + 11);
} else {
/* detached HEAD */
str = "HEAD";
len = 4;
}
}
if (at_time)
warning("Log for '%.*s' only goes "
"back to %s.", len, str,
show_date(co_time, co_tz, DATE_RFC2822));
else {
die("Log for '%.*s' only has %d entries.",
len, str, co_cnt);
}
}
}
free(real_ref);
return 0;
}
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, GET_SHA1_COMMITTISH);
struct commit *commit;
struct commit_list *p;
if (ret)
return ret;
commit = lookup_commit_reference(sha1);
if (parse_commit(commit))
return -1;
if (!idx) {
hashcpy(result, commit->object.sha1);
return 0;
}
p = commit->parents;
while (p) {
if (!--idx) {
hashcpy(result, p->item->object.sha1);
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];
struct commit *commit;
int ret;
ret = get_sha1_1(name, len, sha1, GET_SHA1_COMMITTISH);
if (ret)
return ret;
commit = lookup_commit_reference(sha1);
if (!commit)
return -1;
while (generation--) {
if (parse_commit(commit) || !commit->parents)
return -1;
commit = commit->parents->item;
}
hashcpy(result, commit->object.sha1);
return 0;
}
struct object *peel_to_type(const char *name, int namelen,
struct object *o, enum object_type expected_type)
{
if (name && !namelen)
namelen = strlen(name);
while (1) {
if (!o || (!o->parsed && !parse_object(o->sha1)))
return NULL;
if (expected_type == OBJ_ANY || o->type == expected_type)
return o;
if (o->type == OBJ_TAG)
o = ((struct tag*) o)->tagged;
else if (o->type == OBJ_COMMIT)
o = &(((struct commit *) o)->tree->object);
else {
if (name)
error("%.*s: expected %s type, but the object "
"dereferences to %s type",
namelen, name, typename(expected_type),
typename(o->type));
return NULL;
}
}
}
static int peel_onion(const char *name, int len, unsigned char *sha1)
{
unsigned char outer[20];
const char *sp;
unsigned int expected_type = 0;
unsigned lookup_flags = 0;
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 (starts_with(sp, "commit}"))
expected_type = OBJ_COMMIT;
else if (starts_with(sp, "tag}"))
expected_type = OBJ_TAG;
else if (starts_with(sp, "tree}"))
expected_type = OBJ_TREE;
else if (starts_with(sp, "blob}"))
expected_type = OBJ_BLOB;
else if (starts_with(sp, "object}"))
expected_type = OBJ_ANY;
else if (sp[0] == '}')
expected_type = OBJ_NONE;
else if (sp[0] == '/')
expected_type = OBJ_COMMIT;
else
return -1;
if (expected_type == OBJ_COMMIT)
lookup_flags = GET_SHA1_COMMITTISH;
else if (expected_type == OBJ_TREE)
lookup_flags = GET_SHA1_TREEISH;
if (get_sha1_1(name, sp - name - 2, outer, lookup_flags))
return -1;
o = parse_object(outer);
if (!o)
return -1;
if (!expected_type) {
o = deref_tag(o, name, sp - name - 2);
if (!o || (!o->parsed && !parse_object(o->sha1)))
return -1;
hashcpy(sha1, o->sha1);
return 0;
}
/*
* At this point, the syntax look correct, so
* if we do not get the needed object, we should
* barf.
*/
o = peel_to_type(name, len, o, expected_type);
if (!o)
return -1;
hashcpy(sha1, o->sha1);
if (sp[0] == '/') {
/* "$commit^{/foo}" */
char *prefix;
int ret;
struct commit_list *list = NULL;
/*
* $commit^{/}. Some regex implementation may reject.
* We don't need regex anyway. '' pattern always matches.
*/
if (sp[1] == '}')
return 0;
prefix = xstrndup(sp + 1, name + len - 1 - (sp + 1));
commit_list_insert((struct commit *)o, &list);
ret = get_sha1_oneline(prefix, sha1, list);
free(prefix);
return ret;
}
return 0;
}
static int get_describe_name(const char *name, int len, unsigned char *sha1)
{
const char *cp;
unsigned flags = GET_SHA1_QUIETLY | GET_SHA1_COMMIT;
for (cp = name + len - 1; name + 2 <= cp; cp--) {
char ch = *cp;
if (hexval(ch) & ~0377) {
/* We must be looking at g in "SOMETHING-g"
* for it to be describe output.
*/
if (ch == 'g' && cp[-1] == '-') {
cp++;
len -= cp - name;
return get_short_sha1(cp, len, sha1, flags);
}
}
}
return -1;
}
static int get_sha1_1(const char *name, int len, unsigned char *sha1, unsigned lookup_flags)
{
int ret, has_suffix;
const char *cp;
/*
* "name~3" is "name^^^", "name~" is "name~1", and "name^" 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 (!num && len1 == len - 1)
num = 1;
if (has_suffix == '^')
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;
/* It could be describe output that is "SOMETHING-gXXXX" */
ret = get_describe_name(name, len, sha1);
if (!ret)
return 0;
return get_short_sha1(name, len, sha1, lookup_flags);
}
/*
* This interprets names like ':/Initial revision of "git"' by searching
* through history and returning the first commit whose message starts
* the given regular expression.
*
* For future extension, ':/!' is reserved. If you want to match a message
* beginning with a '!', you have to repeat the exclamation mark.
*/
#define ONELINE_SEEN (1u<<20)
static int handle_one_ref(const char *path,
const unsigned char *sha1, int flag, void *cb_data)
{
struct commit_list **list = cb_data;
struct object *object = parse_object(sha1);
if (!object)
return 0;
if (object->type == OBJ_TAG) {
object = deref_tag(object, path, strlen(path));
if (!object)
return 0;
}
if (object->type != OBJ_COMMIT)
return 0;
commit_list_insert_by_date((struct commit *)object, list);
return 0;
}
static int get_sha1_oneline(const char *prefix, unsigned char *sha1,
struct commit_list *list)
{
struct commit_list *backup = NULL, *l;
int found = 0;
regex_t regex;
if (prefix[0] == '!') {
if (prefix[1] != '!')
die ("Invalid search pattern: %s", prefix);
prefix++;
}
if (regcomp(&regex, prefix, REG_EXTENDED))
die("Invalid search pattern: %s", prefix);
for (l = list; l; l = l->next) {
l->item->object.flags |= ONELINE_SEEN;
commit_list_insert(l->item, &backup);
}
while (list) {
char *p, *to_free = NULL;
struct commit *commit;
enum object_type type;
unsigned long size;
int matches;
commit = pop_most_recent_commit(&list, ONELINE_SEEN);
if (!parse_object(commit->object.sha1))
continue;
if (commit->buffer)
p = commit->buffer;
else {
p = read_sha1_file(commit->object.sha1, &type, &size);
if (!p)
continue;
to_free = p;
}
p = strstr(p, "\n\n");
matches = p && !regexec(&regex, p + 2, 0, NULL, 0);
free(to_free);
if (matches) {
hashcpy(sha1, commit->object.sha1);
found = 1;
break;
}
}
regfree(&regex);
free_commit_list(list);
for (l = backup; l; l = l->next)
clear_commit_marks(l->item, ONELINE_SEEN);
free_commit_list(backup);
return found ? 0 : -1;
}
struct grab_nth_branch_switch_cbdata {
int remaining;
struct strbuf buf;
};
static int grab_nth_branch_switch(unsigned char *osha1, unsigned char *nsha1,
const char *email, unsigned long timestamp, int tz,
const char *message, void *cb_data)
{
struct grab_nth_branch_switch_cbdata *cb = cb_data;
const char *match = NULL, *target = NULL;
size_t len;
if (starts_with(message, "checkout: moving from ")) {
match = message + strlen("checkout: moving from ");
target = strstr(match, " to ");
}
if (!match || !target)
return 0;
if (--(cb->remaining) == 0) {
len = target - match;
strbuf_reset(&cb->buf);
strbuf_add(&cb->buf, match, len);
return 1; /* we are done */
}
return 0;
}
/*
* Parse @{-N} syntax, return the number of characters parsed
* if successful; otherwise signal an error with negative value.
*/
static int interpret_nth_prior_checkout(const char *name, struct strbuf *buf)
{
long nth;
int retval;
struct grab_nth_branch_switch_cbdata cb;
const char *brace;
char *num_end;
if (name[0] != '@' || name[1] != '{' || name[2] != '-')
return -1;
brace = strchr(name, '}');
if (!brace)
return -1;
nth = strtol(name + 3, &num_end, 10);
if (num_end != brace)
return -1;
if (nth <= 0)
return -1;
cb.remaining = nth;
strbuf_init(&cb.buf, 20);
retval = 0;
if (0 < for_each_reflog_ent_reverse("HEAD", grab_nth_branch_switch, &cb)) {
strbuf_reset(buf);
strbuf_add(buf, cb.buf.buf, cb.buf.len);
retval = brace - name + 1;
}
strbuf_release(&cb.buf);
return retval;
}
int get_sha1_mb(const char *name, unsigned char *sha1)
{
struct commit *one, *two;
struct commit_list *mbs;
unsigned char sha1_tmp[20];
const char *dots;
int st;
dots = strstr(name, "...");
if (!dots)
return get_sha1(name, sha1);
if (dots == name)
st = get_sha1("HEAD", sha1_tmp);
else {
struct strbuf sb;
strbuf_init(&sb, dots - name);
strbuf_add(&sb, name, dots - name);
st = get_sha1_committish(sb.buf, sha1_tmp);
strbuf_release(&sb);
}
if (st)
return st;
one = lookup_commit_reference_gently(sha1_tmp, 0);
if (!one)
return -1;
if (get_sha1_committish(dots[3] ? (dots + 3) : "HEAD", sha1_tmp))
return -1;
two = lookup_commit_reference_gently(sha1_tmp, 0);
if (!two)
return -1;
mbs = get_merge_bases(one, two, 1);
if (!mbs || mbs->next)
st = -1;
else {
st = 0;
hashcpy(sha1, mbs->item->object.sha1);
}
free_commit_list(mbs);
return st;
}
/* parse @something syntax, when 'something' is not {.*} */
static int interpret_empty_at(const char *name, int namelen, int len, struct strbuf *buf)
{
const char *next;
if (len || name[1] == '{')
return -1;
/* make sure it's a single @, or @@{.*}, not @foo */
next = strchr(name + len + 1, '@');
if (next && next[1] != '{')
return -1;
if (!next)
next = name + namelen;
if (next != name + 1)
return -1;
strbuf_reset(buf);
strbuf_add(buf, "HEAD", 4);
return 1;
}
static int reinterpret(const char *name, int namelen, int len, struct strbuf *buf)
{
/* we have extra data, which might need further processing */
struct strbuf tmp = STRBUF_INIT;
int used = buf->len;
int ret;
strbuf_add(buf, name + len, namelen - len);
ret = interpret_branch_name(buf->buf, buf->len, &tmp);
/* that data was not interpreted, remove our cruft */
if (ret < 0) {
strbuf_setlen(buf, used);
return len;
}
strbuf_reset(buf);
strbuf_addbuf(buf, &tmp);
strbuf_release(&tmp);
/* tweak for size of {-N} versus expanded ref name */
return ret - used + len;
}
/*
* This reads short-hand syntax that not only evaluates to a commit
* object name, but also can act as if the end user spelled the name
* of the branch from the command line.
*
* - "@{-N}" finds the name of the Nth previous branch we were on, and
* places the name of the branch in the given buf and returns the
* number of characters parsed if successful.
*
* - "<branch>@{upstream}" finds the name of the other ref that
* <branch> is configured to merge with (missing <branch> defaults
* to the current branch), and places the name of the branch in the
* given buf and returns the number of characters parsed if
* successful.
*
* If the input is not of the accepted format, it returns a negative
* number to signal an error.
*
* If the input was ok but there are not N branch switches in the
* reflog, it returns 0.
*/
int interpret_branch_name(const char *name, int namelen, struct strbuf *buf)
{
char *cp;
struct branch *upstream;
int len = interpret_nth_prior_checkout(name, buf);
int tmp_len;
if (!namelen)
namelen = strlen(name);
if (!len) {
return len; /* syntax Ok, not enough switches */
} else if (len > 0) {
if (len == namelen)
return len; /* consumed all */
else
return reinterpret(name, namelen, len, buf);
}
cp = strchr(name, '@');
if (!cp)
return -1;
len = interpret_empty_at(name, namelen, cp - name, buf);
if (len > 0)
return reinterpret(name, namelen, len, buf);
tmp_len = upstream_mark(cp, namelen - (cp - name));
if (!tmp_len)
return -1;
len = cp + tmp_len - name;
cp = xstrndup(name, cp - name);
upstream = branch_get(*cp ? cp : NULL);
/*
* Upstream can be NULL only if cp refers to HEAD and HEAD
* points to something different than a branch.
*/
if (!upstream)
die(_("HEAD does not point to a branch"));
if (!upstream->merge || !upstream->merge[0]->dst) {
if (!ref_exists(upstream->refname))
die(_("No such branch: '%s'"), cp);
if (!upstream->merge) {
die(_("No upstream configured for branch '%s'"),
upstream->name);
}
die(
_("Upstream branch '%s' not stored as a remote-tracking branch"),
upstream->merge[0]->src);
}
free(cp);
cp = shorten_unambiguous_ref(upstream->merge[0]->dst, 0);
strbuf_reset(buf);
strbuf_addstr(buf, cp);
free(cp);
return len;
}
int strbuf_branchname(struct strbuf *sb, const char *name)
{
int len = strlen(name);
int used = interpret_branch_name(name, len, sb);
if (used == len)
return 0;
if (used < 0)
used = 0;
strbuf_add(sb, name + used, len - used);
return len;
}
int strbuf_check_branch_ref(struct strbuf *sb, const char *name)
{
strbuf_branchname(sb, name);
if (name[0] == '-')
return -1;
strbuf_splice(sb, 0, 0, "refs/heads/", 11);
return check_refname_format(sb->buf, 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)
{
struct object_context unused;
return get_sha1_with_context(name, 0, sha1, &unused);
}
/*
* Many callers know that the user meant to name a commit-ish by
* syntactical positions where the object name appears. Calling this
* function allows the machinery to disambiguate shorter-than-unique
* abbreviated object names between commit-ish and others.
*
* Note that this does NOT error out when the named object is not a
* commit-ish. It is merely to give a hint to the disambiguation
* machinery.
*/
int get_sha1_committish(const char *name, unsigned char *sha1)
{
struct object_context unused;
return get_sha1_with_context(name, GET_SHA1_COMMITTISH,
sha1, &unused);
}
int get_sha1_treeish(const char *name, unsigned char *sha1)
{
struct object_context unused;
return get_sha1_with_context(name, GET_SHA1_TREEISH,
sha1, &unused);
}
int get_sha1_commit(const char *name, unsigned char *sha1)
{
struct object_context unused;
return get_sha1_with_context(name, GET_SHA1_COMMIT,
sha1, &unused);
}
int get_sha1_tree(const char *name, unsigned char *sha1)
{
struct object_context unused;
return get_sha1_with_context(name, GET_SHA1_TREE,
sha1, &unused);
}
int get_sha1_blob(const char *name, unsigned char *sha1)
{
struct object_context unused;
return get_sha1_with_context(name, GET_SHA1_BLOB,
sha1, &unused);
}
/* Must be called only when object_name:filename doesn't exist. */
static void diagnose_invalid_sha1_path(const char *prefix,
const char *filename,
const unsigned char *tree_sha1,
const char *object_name,
int object_name_len)
{
struct stat st;
unsigned char sha1[20];
unsigned mode;
if (!prefix)
prefix = "";
if (!lstat(filename, &st))
die("Path '%s' exists on disk, but not in '%.*s'.",
filename, object_name_len, object_name);
if (errno == ENOENT || errno == ENOTDIR) {
char *fullname = xmalloc(strlen(filename)
+ strlen(prefix) + 1);
strcpy(fullname, prefix);
strcat(fullname, filename);
if (!get_tree_entry(tree_sha1, fullname,
sha1, &mode)) {
die("Path '%s' exists, but not '%s'.\n"
"Did you mean '%.*s:%s' aka '%.*s:./%s'?",
fullname,
filename,
object_name_len, object_name,
fullname,
object_name_len, object_name,
filename);
}
die("Path '%s' does not exist in '%.*s'",
filename, object_name_len, object_name);
}
}
/* Must be called only when :stage:filename doesn't exist. */
static void diagnose_invalid_index_path(int stage,
const char *prefix,
const char *filename)
{
struct stat st;
const struct cache_entry *ce;
int pos;
unsigned namelen = strlen(filename);
unsigned fullnamelen;
char *fullname;
if (!prefix)
prefix = "";
/* Wrong stage number? */
pos = cache_name_pos(filename, namelen);
if (pos < 0)
pos = -pos - 1;
if (pos < active_nr) {
ce = active_cache[pos];
if (ce_namelen(ce) == namelen &&
!memcmp(ce->name, filename, namelen))
die("Path '%s' is in the index, but not at stage %d.\n"
"Did you mean ':%d:%s'?",
filename, stage,
ce_stage(ce), filename);
}
/* Confusion between relative and absolute filenames? */
fullnamelen = namelen + strlen(prefix);
fullname = xmalloc(fullnamelen + 1);
strcpy(fullname, prefix);
strcat(fullname, filename);
pos = cache_name_pos(fullname, fullnamelen);
if (pos < 0)
pos = -pos - 1;
if (pos < active_nr) {
ce = active_cache[pos];
if (ce_namelen(ce) == fullnamelen &&
!memcmp(ce->name, fullname, fullnamelen))
die("Path '%s' is in the index, but not '%s'.\n"
"Did you mean ':%d:%s' aka ':%d:./%s'?",
fullname, filename,
ce_stage(ce), fullname,
ce_stage(ce), filename);
}
if (!lstat(filename, &st))
die("Path '%s' exists on disk, but not in the index.", filename);
if (errno == ENOENT || errno == ENOTDIR)
die("Path '%s' does not exist (neither on disk nor in the index).",
filename);
free(fullname);
}
static char *resolve_relative_path(const char *rel)
{
if (!starts_with(rel, "./") && !starts_with(rel, "../"))
return NULL;
if (!startup_info)
die("BUG: startup_info struct is not initialized.");
if (!is_inside_work_tree())
die("relative path syntax can't be used outside working tree.");
/* die() inside prefix_path() if resolved path is outside worktree */
return prefix_path(startup_info->prefix,
startup_info->prefix ? strlen(startup_info->prefix) : 0,
rel);
}
static int get_sha1_with_context_1(const char *name,
unsigned flags,
const char *prefix,
unsigned char *sha1,
struct object_context *oc)
{
int ret, bracket_depth;
int namelen = strlen(name);
const char *cp;
int only_to_die = flags & GET_SHA1_ONLY_TO_DIE;
memset(oc, 0, sizeof(*oc));
oc->mode = S_IFINVALID;
ret = get_sha1_1(name, namelen, sha1, flags);
if (!ret)
return ret;
/*
* sha1:path --> object name of path in ent sha1
* :path -> object name of absolute path in index
* :./path -> object name of path relative to cwd in index
* :[0-3]:path -> object name of path in index at stage
* :/foo -> recent commit matching foo
*/
if (name[0] == ':') {
int stage = 0;
const struct cache_entry *ce;
char *new_path = NULL;
int pos;
if (!only_to_die && namelen > 2 && name[1] == '/') {
struct commit_list *list = NULL;
for_each_ref(handle_one_ref, &list);
return get_sha1_oneline(name + 2, sha1, list);
}
if (namelen < 3 ||
name[2] != ':' ||
name[1] < '0' || '3' < name[1])
cp = name + 1;
else {
stage = name[1] - '0';
cp = name + 3;
}
new_path = resolve_relative_path(cp);
if (!new_path) {
namelen = namelen - (cp - name);
} else {
cp = new_path;
namelen = strlen(cp);
}
strncpy(oc->path, cp,
sizeof(oc->path));
oc->path[sizeof(oc->path)-1] = '\0';
if (!active_cache)
read_cache();
pos = cache_name_pos(cp, namelen);
if (pos < 0)
pos = -pos - 1;
while (pos < active_nr) {
ce = active_cache[pos];
if (ce_namelen(ce) != namelen ||
memcmp(ce->name, cp, namelen))
break;
if (ce_stage(ce) == stage) {
hashcpy(sha1, ce->sha1);
oc->mode = ce->ce_mode;
free(new_path);
return 0;
}
pos++;
}
if (only_to_die && name[1] && name[1] != '/')
diagnose_invalid_index_path(stage, prefix, cp);
free(new_path);
return -1;
}
for (cp = name, bracket_depth = 0; *cp; cp++) {
if (*cp == '{')
bracket_depth++;
else if (bracket_depth && *cp == '}')
bracket_depth--;
else if (!bracket_depth && *cp == ':')
break;
}
if (*cp == ':') {
unsigned char tree_sha1[20];
int len = cp - name;
if (!get_sha1_1(name, len, tree_sha1, GET_SHA1_TREEISH)) {
const char *filename = cp+1;
char *new_filename = NULL;
new_filename = resolve_relative_path(filename);
if (new_filename)
filename = new_filename;
ret = get_tree_entry(tree_sha1, filename, sha1, &oc->mode);
if (ret && only_to_die) {
diagnose_invalid_sha1_path(prefix, filename,
tree_sha1,
name, len);
}
hashcpy(oc->tree, tree_sha1);
strncpy(oc->path, filename,
sizeof(oc->path));
oc->path[sizeof(oc->path)-1] = '\0';
free(new_filename);
return ret;
} else {
if (only_to_die)
die("Invalid object name '%.*s'.", len, name);
}
}
return ret;
}
/*
* Call this function when you know "name" given by the end user must
* name an object but it doesn't; the function _may_ die with a better
* diagnostic message than "no such object 'name'", e.g. "Path 'doc' does not
* exist in 'HEAD'" when given "HEAD:doc", or it may return in which case
* you have a chance to diagnose the error further.
*/
void maybe_die_on_misspelt_object_name(const char *name, const char *prefix)
{
struct object_context oc;
unsigned char sha1[20];
get_sha1_with_context_1(name, GET_SHA1_ONLY_TO_DIE, prefix, sha1, &oc);
}
int get_sha1_with_context(const char *str, unsigned flags, unsigned char *sha1, struct object_context *orc)
{
return get_sha1_with_context_1(str, flags, NULL, sha1, orc);
}