diff options
Diffstat (limited to 'sha1_name.c')
| -rw-r--r-- | sha1_name.c | 1386 |
1 files changed, 1386 insertions, 0 deletions
diff --git a/sha1_name.c b/sha1_name.c new file mode 100644 index 0000000..95003c7 --- /dev/null +++ b/sha1_name.c @@ -0,0 +1,1386 @@ +#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 satisify 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(lookup_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 get_sha1_basic(const char *str, int len, unsigned char *sha1) +{ + static const char *warn_msg = "refname '%.*s' is ambiguous."; + char *real_ref = NULL; + int refs_found = 0; + int at, reflog_len; + + if (len == 40 && !get_sha1_hex(str, sha1)) + 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-2; at >= 0; at--) { + if (str[at] == '@' && str[at+1] == '{') { + 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 (!len && reflog_len) { + struct strbuf buf = STRBUF_INIT; + int ret; + /* try the @{-N} syntax for n-th checkout */ + ret = interpret_branch_name(str+at, &buf); + if (ret > 0) { + /* substitute this branch name and restart */ + return get_sha1_1(buf.buf, buf.len, sha1, 0); + } else if (ret == 0) { + return -1; + } + /* 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) + warning(warn_msg, len, str); + + if (reflog_len) { + int nth, i; + unsigned long at_time; + unsigned long co_time; + int co_tz, co_cnt; + + /* a @{-N} placed anywhere except the start is an error */ + if (str[at+2] == '-') + return -1; + + /* 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 (at_time) + warning("Log for '%.*s' only goes " + "back to %s.", len, str, + show_date(co_time, co_tz, DATE_RFC2822)); + else { + free(real_ref); + 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 (!commit) + return -1; + 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 (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 (!strncmp(commit_type, sp, 6) && sp[6] == '}') + expected_type = OBJ_COMMIT; + else if (!strncmp(tree_type, sp, 4) && sp[4] == '}') + expected_type = OBJ_TREE; + else if (!strncmp(blob_type, sp, 4) && sp[4] == '}') + expected_type = OBJ_BLOB; + 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; + + 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(®ex, 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(®ex, p + 2, 0, NULL, 0); + free(to_free); + + if (matches) { + hashcpy(sha1, commit->object.sha1); + found = 1; + break; + } + } + regfree(®ex); + 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 { + long cnt, alloc; + 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; + int nth; + + if (!prefixcmp(message, "checkout: moving from ")) { + match = message + strlen("checkout: moving from "); + target = strstr(match, " to "); + } + + if (!match || !target) + return 0; + + len = target - match; + nth = cb->cnt++ % cb->alloc; + strbuf_reset(&cb->buf[nth]); + strbuf_add(&cb->buf[nth], match, len); + 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 i, 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.alloc = nth; + cb.buf = xmalloc(nth * sizeof(struct strbuf)); + for (i = 0; i < nth; i++) + strbuf_init(&cb.buf[i], 20); + cb.cnt = 0; + retval = 0; + for_each_recent_reflog_ent("HEAD", grab_nth_branch_switch, 40960, &cb); + if (cb.cnt < nth) { + cb.cnt = 0; + for_each_reflog_ent("HEAD", grab_nth_branch_switch, &cb); + } + if (cb.cnt < nth) + goto release_return; + i = cb.cnt % nth; + strbuf_reset(buf); + strbuf_add(buf, cb.buf[i].buf, cb.buf[i].len); + retval = brace-name+1; + +release_return: + for (i = 0; i < nth; i++) + strbuf_release(&cb.buf[i]); + free(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; +} + +/* + * 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, struct strbuf *buf) +{ + char *cp; + struct branch *upstream; + int namelen = strlen(name); + int len = interpret_nth_prior_checkout(name, buf); + int tmp_len; + + if (!len) + return len; /* syntax Ok, not enough switches */ + if (0 < len && len == namelen) + return len; /* consumed all */ + else if (0 < len) { + /* 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, &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; + } + + cp = strchr(name, '@'); + if (!cp) + return -1; + 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) + return error(_("HEAD does not point to a branch")); + if (!upstream->merge || !upstream->merge[0]->dst) { + if (!ref_exists(upstream->refname)) + return error(_("No such branch: '%s'"), cp); + if (!upstream->merge) + return error(_("No upstream configured for branch '%s'"), + upstream->name); + return error( + _("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); + if (interpret_branch_name(name, sb) == len) + return 0; + strbuf_add(sb, name, len); + 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 committish by + * syntactical positions where the object name appears. Calling this + * function allows the machinery to disambiguate shorter-than-unique + * abbreviated object names between committish and others. + * + * Note that this does NOT error out when the named object is not a + * committish. 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) +{ + 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); + 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, + fullname, + object_name, + filename); + } + die("Path '%s' does not exist in '%s'", + filename, 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; + 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 (prefixcmp(rel, "./") && prefixcmp(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; + 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]; + char *object_name = NULL; + if (only_to_die) { + object_name = xmalloc(cp-name+1); + strncpy(object_name, name, cp-name); + object_name[cp-name] = '\0'; + } + if (!get_sha1_1(name, cp-name, 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, object_name); + free(object_name); + } + 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'.", object_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); +} |