git/sha1_name.c
David Turner c4ec96774b sha1_name: get_sha1_with_context learns to follow symlinks
Wire up get_sha1_with_context to call get_tree_entry_follow_symlinks
when GET_SHA1_FOLLOW_SYMLINKS is passed in flags. G_S_FOLLOW_SYMLINKS
is incompatible with G_S_ONLY_TO_DIE because the diagnosis
that ONLY_TO_DIE triggers does not at present consider symlinks, and
it would be a significant amount of additional code to allow it to
do so.

Signed-off-by: David Turner <dturner@twopensource.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2015-05-20 13:46:13 -07:00

1484 lines
36 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];
memcpy(hex, sha1_to_hex(sha1), 40);
if (len == 40 || !len)
return hex;
exists = has_sha1_file(sha1);
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, int namelen, struct strbuf *buf);
static int get_sha1_basic(const char *str, int len, unsigned char *sha1,
unsigned int flags)
{
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, len, &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 && !(flags & GET_SHA1_QUIETLY) &&
(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) {
free(real_ref);
return -1;
}
}
if (read_ref_at(real_ref, flags, 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) {
if (!(flags & GET_SHA1_QUIETLY)) {
warning("Log for '%.*s' only goes "
"back to %s.", len, str,
show_date(co_time, co_tz, DATE_RFC2822));
}
} else {
if (flags & GET_SHA1_QUIETLY) {
exit(128);
}
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 (!isxdigit(ch)) {
/* 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, lookup_flags);
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.
*/
/* Remember to update object flag allocation in object.h */
#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((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) {
const char *p, *buf;
struct commit *commit;
int matches;
commit = pop_most_recent_commit(&list, ONELINE_SEEN);
if (!parse_object(commit->object.sha1))
continue;
buf = get_commit_buffer(commit, NULL);
p = strstr(buf, "\n\n");
matches = p && !regexec(&regex, p + 2, 0, NULL, 0);
unuse_commit_buffer(commit, buf);
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 (skip_prefix(message, "checkout: moving from ", &match))
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, int namelen,
struct strbuf *buf)
{
long nth;
int retval;
struct grab_nth_branch_switch_cbdata cb;
const char *brace;
char *num_end;
if (namelen < 4)
return -1;
if (name[0] != '@' || name[1] != '{' || name[2] != '-')
return -1;
brace = memchr(name, '}', namelen);
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_addbuf(buf, &cb.buf);
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);
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 = memchr(name + len + 1, '@', namelen - 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;
}
static void set_shortened_ref(struct strbuf *buf, const char *ref)
{
char *s = shorten_unambiguous_ref(ref, 0);
strbuf_reset(buf);
strbuf_addstr(buf, s);
free(s);
}
static const char *get_upstream_branch(const char *branch_buf, int len)
{
char *branch = xstrndup(branch_buf, len);
struct branch *upstream = branch_get(*branch ? branch : NULL);
/*
* Upstream can be NULL only if branch 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'"), branch);
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(branch);
return upstream->merge[0]->dst;
}
static int interpret_upstream_mark(const char *name, int namelen,
int at, struct strbuf *buf)
{
int len;
len = upstream_mark(name + at, namelen - at);
if (!len)
return -1;
if (memchr(name, ':', at))
return -1;
set_shortened_ref(buf, get_upstream_branch(name, at));
return len + at;
}
/*
* 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 *at;
const char *start;
int len = interpret_nth_prior_checkout(name, namelen, buf);
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);
}
for (start = name;
(at = memchr(start, '@', namelen - (start - name)));
start = at + 1) {
len = interpret_empty_at(name, namelen, at - name, buf);
if (len > 0)
return reinterpret(name, namelen, len, buf);
len = interpret_upstream_mark(name, namelen, at - name, buf);
if (len > 0)
return len;
}
return -1;
}
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 = xstrfmt("%s%s", prefix, 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);
commit_list_sort_by_date(&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);
}
strlcpy(oc->path, cp, sizeof(oc->path));
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;
if (flags & GET_SHA1_FOLLOW_SYMLINKS) {
ret = get_tree_entry_follow_symlinks(tree_sha1,
filename, sha1, &oc->symlink_path,
&oc->mode);
} else {
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);
strlcpy(oc->path, filename, sizeof(oc->path));
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)
{
if (flags & GET_SHA1_FOLLOW_SYMLINKS && flags & GET_SHA1_ONLY_TO_DIE)
die("BUG: incompatible flags for get_sha1_with_context");
return get_sha1_with_context_1(str, flags, NULL, sha1, orc);
}