diff options
Diffstat (limited to 'sha1-name.c')
| -rw-r--r-- | sha1-name.c | 1767 |
1 files changed, 1767 insertions, 0 deletions
diff --git a/sha1-name.c b/sha1-name.c new file mode 100644 index 0000000000..60d9ef3c7e --- /dev/null +++ b/sha1-name.c @@ -0,0 +1,1767 @@ +#include "cache.h" +#include "config.h" +#include "tag.h" +#include "commit.h" +#include "tree.h" +#include "blob.h" +#include "tree-walk.h" +#include "refs.h" +#include "remote.h" +#include "dir.h" +#include "sha1-array.h" +#include "packfile.h" +#include "object-store.h" +#include "repository.h" + +static int get_oid_oneline(const char *, struct object_id *, struct commit_list *); + +typedef int (*disambiguate_hint_fn)(const struct object_id *, void *); + +struct disambiguate_state { + int len; /* length of prefix in hex chars */ + char hex_pfx[GIT_MAX_HEXSZ + 1]; + struct object_id bin_pfx; + + disambiguate_hint_fn fn; + void *cb_data; + struct object_id candidate; + 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 struct object_id *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 */ + oidcpy(&ds->candidate, current); + ds->candidate_exists = 1; + return; + } else if (!oidcmp(&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 */ + oidcpy(&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 int append_loose_object(const struct object_id *oid, const char *path, + void *data) +{ + oid_array_append(data, oid); + return 0; +} + +static int match_sha(unsigned, const unsigned char *, const unsigned char *); + +static void find_short_object_filename(struct disambiguate_state *ds) +{ + int subdir_nr = ds->bin_pfx.hash[0]; + struct alternate_object_database *alt; + 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. + */ + fakeent = alloc_alt_odb(get_object_directory()); + } + fakeent->next = the_repository->objects->alt_odb_list; + + for (alt = fakeent; alt && !ds->ambiguous; alt = alt->next) { + int pos; + + if (!alt->loose_objects_subdir_seen[subdir_nr]) { + struct strbuf *buf = alt_scratch_buf(alt); + for_each_file_in_obj_subdir(subdir_nr, buf, + append_loose_object, + NULL, NULL, + &alt->loose_objects_cache); + alt->loose_objects_subdir_seen[subdir_nr] = 1; + } + + pos = oid_array_lookup(&alt->loose_objects_cache, &ds->bin_pfx); + if (pos < 0) + pos = -1 - pos; + while (!ds->ambiguous && pos < alt->loose_objects_cache.nr) { + const struct object_id *oid; + oid = alt->loose_objects_cache.oid + pos; + if (!match_sha(ds->len, ds->bin_pfx.hash, oid->hash)) + break; + update_candidates(ds, oid); + pos++; + } + } +} + +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(struct packed_git *p, + struct disambiguate_state *ds) +{ + uint32_t num, i, first = 0; + const struct object_id *current = NULL; + + if (open_pack_index(p) || !p->num_objects) + return; + + num = p->num_objects; + bsearch_pack(&ds->bin_pfx, p, &first); + + /* + * 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++) { + struct object_id oid; + current = nth_packed_object_oid(&oid, p, i); + if (!match_sha(ds->len, ds->bin_pfx.hash, current->hash)) + break; + update_candidates(ds, current); + } +} + +static void find_short_packed_object(struct disambiguate_state *ds) +{ + struct packed_git *p; + + for (p = get_packed_git(the_repository); p && !ds->ambiguous; + p = p->next) + unique_in_pack(p, ds); +} + +#define SHORT_NAME_NOT_FOUND (-1) +#define SHORT_NAME_AMBIGUOUS (-2) + +static int finish_object_disambiguation(struct disambiguate_state *ds, + struct object_id *oid) +{ + 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; + + oidcpy(oid, &ds->candidate); + return 0; +} + +static int disambiguate_commit_only(const struct object_id *oid, void *cb_data_unused) +{ + int kind = oid_object_info(the_repository, oid, NULL); + return kind == OBJ_COMMIT; +} + +static int disambiguate_committish_only(const struct object_id *oid, void *cb_data_unused) +{ + struct object *obj; + int kind; + + kind = oid_object_info(the_repository, oid, 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(oid), NULL, 0); + if (obj && obj->type == OBJ_COMMIT) + return 1; + return 0; +} + +static int disambiguate_tree_only(const struct object_id *oid, void *cb_data_unused) +{ + int kind = oid_object_info(the_repository, oid, NULL); + return kind == OBJ_TREE; +} + +static int disambiguate_treeish_only(const struct object_id *oid, void *cb_data_unused) +{ + struct object *obj; + int kind; + + kind = oid_object_info(the_repository, oid, 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(parse_object(oid), NULL, 0); + if (obj && (obj->type == OBJ_TREE || obj->type == OBJ_COMMIT)) + return 1; + return 0; +} + +static int disambiguate_blob_only(const struct object_id *oid, void *cb_data_unused) +{ + int kind = oid_object_info(the_repository, oid, NULL); + return kind == OBJ_BLOB; +} + +static disambiguate_hint_fn default_disambiguate_hint; + +int set_disambiguate_hint_config(const char *var, const char *value) +{ + static const struct { + const char *name; + disambiguate_hint_fn fn; + } hints[] = { + { "none", NULL }, + { "commit", disambiguate_commit_only }, + { "committish", disambiguate_committish_only }, + { "tree", disambiguate_tree_only }, + { "treeish", disambiguate_treeish_only }, + { "blob", disambiguate_blob_only } + }; + int i; + + if (!value) + return config_error_nonbool(var); + + for (i = 0; i < ARRAY_SIZE(hints); i++) { + if (!strcasecmp(value, hints[i].name)) { + default_disambiguate_hint = hints[i].fn; + return 0; + } + } + + return error("unknown hint type for '%s': %s", var, value); +} + +static int init_object_disambiguation(const char *name, int len, + struct disambiguate_state *ds) +{ + int i; + + if (len < MINIMUM_ABBREV || len > GIT_SHA1_HEXSZ) + return -1; + + memset(ds, 0, sizeof(*ds)); + + 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; + ds->hex_pfx[i] = c; + if (!(i & 1)) + val <<= 4; + ds->bin_pfx.hash[i >> 1] |= val; + } + + ds->len = len; + ds->hex_pfx[len] = '\0'; + prepare_alt_odb(the_repository); + return 0; +} + +static int show_ambiguous_object(const struct object_id *oid, void *data) +{ + const struct disambiguate_state *ds = data; + struct strbuf desc = STRBUF_INIT; + int type; + + if (ds->fn && !ds->fn(oid, ds->cb_data)) + return 0; + + type = oid_object_info(the_repository, oid, NULL); + if (type == OBJ_COMMIT) { + struct commit *commit = lookup_commit(oid); + if (commit) { + struct pretty_print_context pp = {0}; + pp.date_mode.type = DATE_SHORT; + format_commit_message(commit, " %ad - %s", &desc, &pp); + } + } else if (type == OBJ_TAG) { + struct tag *tag = lookup_tag(oid); + if (!parse_tag(tag) && tag->tag) + strbuf_addf(&desc, " %s", tag->tag); + } + + advise(" %s %s%s", + find_unique_abbrev(oid, DEFAULT_ABBREV), + type_name(type) ? type_name(type) : "unknown type", + desc.buf); + + strbuf_release(&desc); + return 0; +} + +static int collect_ambiguous(const struct object_id *oid, void *data) +{ + oid_array_append(data, oid); + return 0; +} + +static int sort_ambiguous(const void *a, const void *b) +{ + int a_type = oid_object_info(the_repository, a, NULL); + int b_type = oid_object_info(the_repository, b, NULL); + int a_type_sort; + int b_type_sort; + + /* + * Sorts by hash within the same object type, just as + * oid_array_for_each_unique() would do. + */ + if (a_type == b_type) + return oidcmp(a, b); + + /* + * Between object types show tags, then commits, and finally + * trees and blobs. + * + * The object_type enum is commit, tree, blob, tag, but we + * want tag, commit, tree blob. Cleverly (perhaps too + * cleverly) do that with modulus, since the enum assigns 1 to + * commit, so tag becomes 0. + */ + a_type_sort = a_type % 4; + b_type_sort = b_type % 4; + return a_type_sort > b_type_sort ? 1 : -1; +} + +static int get_short_oid(const char *name, int len, struct object_id *oid, + unsigned flags) +{ + int status; + struct disambiguate_state ds; + int quietly = !!(flags & GET_OID_QUIETLY); + + if (init_object_disambiguation(name, len, &ds) < 0) + return -1; + + if (HAS_MULTI_BITS(flags & GET_OID_DISAMBIGUATORS)) + BUG("multiple get_short_oid disambiguator flags"); + + if (flags & GET_OID_COMMIT) + ds.fn = disambiguate_commit_only; + else if (flags & GET_OID_COMMITTISH) + ds.fn = disambiguate_committish_only; + else if (flags & GET_OID_TREE) + ds.fn = disambiguate_tree_only; + else if (flags & GET_OID_TREEISH) + ds.fn = disambiguate_treeish_only; + else if (flags & GET_OID_BLOB) + ds.fn = disambiguate_blob_only; + else + ds.fn = default_disambiguate_hint; + + find_short_object_filename(&ds); + find_short_packed_object(&ds); + status = finish_object_disambiguation(&ds, oid); + + if (!quietly && (status == SHORT_NAME_AMBIGUOUS)) { + struct oid_array collect = OID_ARRAY_INIT; + + error(_("short SHA1 %s is ambiguous"), ds.hex_pfx); + + /* + * We may still have ambiguity if we simply saw a series of + * candidates that did not satisfy our hint function. In + * that case, we still want to show them, so disable the hint + * function entirely. + */ + if (!ds.ambiguous) + ds.fn = NULL; + + advise(_("The candidates are:")); + for_each_abbrev(ds.hex_pfx, collect_ambiguous, &collect); + QSORT(collect.oid, collect.nr, sort_ambiguous); + + if (oid_array_for_each(&collect, show_ambiguous_object, &ds)) + BUG("show_ambiguous_object shouldn't return non-zero"); + oid_array_clear(&collect); + } + + return status; +} + +int for_each_abbrev(const char *prefix, each_abbrev_fn fn, void *cb_data) +{ + struct oid_array collect = OID_ARRAY_INIT; + struct disambiguate_state ds; + int ret; + + if (init_object_disambiguation(prefix, strlen(prefix), &ds) < 0) + return -1; + + ds.always_call_fn = 1; + ds.fn = collect_ambiguous; + ds.cb_data = &collect; + find_short_object_filename(&ds); + find_short_packed_object(&ds); + + ret = oid_array_for_each_unique(&collect, fn, cb_data); + oid_array_clear(&collect); + return ret; +} + +/* + * Return the slot of the most-significant bit set in "val". There are various + * ways to do this quickly with fls() or __builtin_clzl(), but speed is + * probably not a big deal here. + */ +static unsigned msb(unsigned long val) +{ + unsigned r = 0; + while (val >>= 1) + r++; + return r; +} + +struct min_abbrev_data { + unsigned int init_len; + unsigned int cur_len; + char *hex; + const struct object_id *oid; +}; + +static inline char get_hex_char_from_oid(const struct object_id *oid, + unsigned int pos) +{ + static const char hex[] = "0123456789abcdef"; + + if ((pos & 1) == 0) + return hex[oid->hash[pos >> 1] >> 4]; + else + return hex[oid->hash[pos >> 1] & 0xf]; +} + +static int extend_abbrev_len(const struct object_id *oid, void *cb_data) +{ + struct min_abbrev_data *mad = cb_data; + + unsigned int i = mad->init_len; + while (mad->hex[i] && mad->hex[i] == get_hex_char_from_oid(oid, i)) + i++; + + if (i < GIT_MAX_RAWSZ && i >= mad->cur_len) + mad->cur_len = i + 1; + + return 0; +} + +static void find_abbrev_len_for_pack(struct packed_git *p, + struct min_abbrev_data *mad) +{ + int match = 0; + uint32_t num, first = 0; + struct object_id oid; + const struct object_id *mad_oid; + + if (open_pack_index(p) || !p->num_objects) + return; + + num = p->num_objects; + mad_oid = mad->oid; + match = bsearch_pack(mad_oid, p, &first); + + /* + * first is now the position in the packfile where we would insert + * mad->hash if it does not exist (or the position of mad->hash if + * it does exist). Hence, we consider a maximum of two objects + * nearby for the abbreviation length. + */ + mad->init_len = 0; + if (!match) { + if (nth_packed_object_oid(&oid, p, first)) + extend_abbrev_len(&oid, mad); + } else if (first < num - 1) { + if (nth_packed_object_oid(&oid, p, first + 1)) + extend_abbrev_len(&oid, mad); + } + if (first > 0) { + if (nth_packed_object_oid(&oid, p, first - 1)) + extend_abbrev_len(&oid, mad); + } + mad->init_len = mad->cur_len; +} + +static void find_abbrev_len_packed(struct min_abbrev_data *mad) +{ + struct packed_git *p; + + for (p = get_packed_git(the_repository); p; p = p->next) + find_abbrev_len_for_pack(p, mad); +} + +int find_unique_abbrev_r(char *hex, const struct object_id *oid, int len) +{ + struct disambiguate_state ds; + struct min_abbrev_data mad; + struct object_id oid_ret; + if (len < 0) { + unsigned long count = approximate_object_count(); + /* + * Add one because the MSB only tells us the highest bit set, + * not including the value of all the _other_ bits (so "15" + * is only one off of 2^4, but the MSB is the 3rd bit. + */ + len = msb(count) + 1; + /* + * We now know we have on the order of 2^len objects, which + * expects a collision at 2^(len/2). But we also care about hex + * chars, not bits, and there are 4 bits per hex. So all + * together we need to divide by 2 and round up. + */ + len = DIV_ROUND_UP(len, 2); + /* + * For very small repos, we stick with our regular fallback. + */ + if (len < FALLBACK_DEFAULT_ABBREV) + len = FALLBACK_DEFAULT_ABBREV; + } + + oid_to_hex_r(hex, oid); + if (len == GIT_SHA1_HEXSZ || !len) + return GIT_SHA1_HEXSZ; + + mad.init_len = len; + mad.cur_len = len; + mad.hex = hex; + mad.oid = oid; + + find_abbrev_len_packed(&mad); + + if (init_object_disambiguation(hex, mad.cur_len, &ds) < 0) + return -1; + + ds.fn = extend_abbrev_len; + ds.always_call_fn = 1; + ds.cb_data = (void *)&mad; + + find_short_object_filename(&ds); + (void)finish_object_disambiguation(&ds, &oid_ret); + + hex[mad.cur_len] = 0; + return mad.cur_len; +} + +const char *find_unique_abbrev(const struct object_id *oid, int len) +{ + static int bufno; + static char hexbuffer[4][GIT_MAX_HEXSZ + 1]; + char *hex = hexbuffer[bufno]; + bufno = (bufno + 1) % ARRAY_SIZE(hexbuffer); + find_unique_abbrev_r(hex, oid, 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 at_mark(const char *string, int len, + const char **suffix, int nr) +{ + int i; + + for (i = 0; i < nr; i++) { + int suffix_len = strlen(suffix[i]); + if (suffix_len <= len + && !strncasecmp(string, suffix[i], suffix_len)) + return suffix_len; + } + return 0; +} + +static inline int upstream_mark(const char *string, int len) +{ + const char *suffix[] = { "@{upstream}", "@{u}" }; + return at_mark(string, len, suffix, ARRAY_SIZE(suffix)); +} + +static inline int push_mark(const char *string, int len) +{ + const char *suffix[] = { "@{push}" }; + return at_mark(string, len, suffix, ARRAY_SIZE(suffix)); +} + +static int get_oid_1(const char *name, int len, struct object_id *oid, unsigned lookup_flags); +static int interpret_nth_prior_checkout(const char *name, int namelen, struct strbuf *buf); + +static int get_oid_basic(const char *str, int len, struct object_id *oid, + 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\""); + struct object_id tmp_oid; + char *real_ref = NULL; + int refs_found = 0; + int at, reflog_len, nth_prior = 0; + + if (len == GIT_SHA1_HEXSZ && !get_oid_hex(str, oid)) { + if (warn_ambiguous_refs && warn_on_object_refname_ambiguity) { + refs_found = dwim_ref(str, len, &tmp_oid, &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) && + !push_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 == GIT_SHA1_HEXSZ && !get_oid_hex(buf.buf, oid)); + strbuf_release(&buf); + if (detached) + return 0; + } + } + + if (!len && reflog_len) + /* allow "@{...}" to mean the current branch reflog */ + refs_found = dwim_ref("HEAD", 4, oid, &real_ref); + else if (reflog_len) + refs_found = dwim_log(str, len, oid, &real_ref); + else + refs_found = dwim_ref(str, len, oid, &real_ref); + + if (!refs_found) + return -1; + + if (warn_ambiguous_refs && !(flags & GET_OID_QUIETLY) && + (refs_found > 1 || + !get_short_oid(str, len, &tmp_oid, GET_OID_QUIETLY))) + warning(warn_msg, len, str); + + if (reflog_len) { + int nth, i; + timestamp_t at_time; + timestamp_t 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, oid, 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_OID_QUIETLY)) { + warning("Log for '%.*s' only goes " + "back to %s.", len, str, + show_date(co_time, co_tz, DATE_MODE(RFC2822))); + } + } else { + if (flags & GET_OID_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, + struct object_id *result, int idx) +{ + struct object_id oid; + int ret = get_oid_1(name, len, &oid, GET_OID_COMMITTISH); + struct commit *commit; + struct commit_list *p; + + if (ret) + return ret; + commit = lookup_commit_reference(&oid); + if (parse_commit(commit)) + return -1; + if (!idx) { + oidcpy(result, &commit->object.oid); + return 0; + } + p = commit->parents; + while (p) { + if (!--idx) { + oidcpy(result, &p->item->object.oid); + return 0; + } + p = p->next; + } + return -1; +} + +static int get_nth_ancestor(const char *name, int len, + struct object_id *result, int generation) +{ + struct object_id oid; + struct commit *commit; + int ret; + + ret = get_oid_1(name, len, &oid, GET_OID_COMMITTISH); + if (ret) + return ret; + commit = lookup_commit_reference(&oid); + if (!commit) + return -1; + + while (generation--) { + if (parse_commit(commit) || !commit->parents) + return -1; + commit = commit->parents->item; + } + oidcpy(result, &commit->object.oid); + 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->oid))) + 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 = &(get_commit_tree(((struct commit *)o))->object); + else { + if (name) + error("%.*s: expected %s type, but the object " + "dereferences to %s type", + namelen, name, type_name(expected_type), + type_name(o->type)); + return NULL; + } + } +} + +static int peel_onion(const char *name, int len, struct object_id *oid, + unsigned lookup_flags) +{ + struct object_id outer; + const char *sp; + unsigned int expected_type = 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; + + lookup_flags &= ~GET_OID_DISAMBIGUATORS; + if (expected_type == OBJ_COMMIT) + lookup_flags |= GET_OID_COMMITTISH; + else if (expected_type == OBJ_TREE) + lookup_flags |= GET_OID_TREEISH; + + if (get_oid_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->oid))) + return -1; + oidcpy(oid, &o->oid); + 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; + + oidcpy(oid, &o->oid); + 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_oid_oneline(prefix, oid, list); + free(prefix); + return ret; + } + return 0; +} + +static int get_describe_name(const char *name, int len, struct object_id *oid) +{ + const char *cp; + unsigned flags = GET_OID_QUIETLY | GET_OID_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_oid(cp, len, oid, flags); + } + } + } + return -1; +} + +static int get_oid_1(const char *name, int len, struct object_id *oid, 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, oid, num); + /* else if (has_suffix == '~') -- goes without saying */ + return get_nth_ancestor(name, len1, oid, num); + } + + ret = peel_onion(name, len, oid, lookup_flags); + if (!ret) + return 0; + + ret = get_oid_basic(name, len, oid, lookup_flags); + if (!ret) + return 0; + + /* It could be describe output that is "SOMETHING-gXXXX" */ + ret = get_describe_name(name, len, oid); + if (!ret) + return 0; + + return get_short_oid(name, len, oid, 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 negative-matching, prefix the pattern-part with '!-', like: ':/!-WIP'. + * + * For a literal '!' character at the beginning of a pattern, you have to repeat + * that, like: ':/!!foo' + * + * For future extension, all other sequences beginning with ':/!' are reserved. + */ + +/* Remember to update object flag allocation in object.h */ +#define ONELINE_SEEN (1u<<20) + +static int handle_one_ref(const char *path, const struct object_id *oid, + int flag, void *cb_data) +{ + struct commit_list **list = cb_data; + struct object *object = parse_object(oid); + 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_oid_oneline(const char *prefix, struct object_id *oid, + struct commit_list *list) +{ + struct commit_list *backup = NULL, *l; + int found = 0; + int negative = 0; + regex_t regex; + + if (prefix[0] == '!') { + prefix++; + + if (prefix[0] == '-') { + prefix++; + negative = 1; + } else if (prefix[0] != '!') { + return -1; + } + } + + if (regcomp(®ex, prefix, REG_EXTENDED)) + return -1; + + 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.oid)) + continue; + buf = get_commit_buffer(commit, NULL); + p = strstr(buf, "\n\n"); + matches = negative ^ (p && !regexec(®ex, p + 2, 0, NULL, 0)); + unuse_commit_buffer(commit, buf); + + if (matches) { + oidcpy(oid, &commit->object.oid); + 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 { + int remaining; + struct strbuf buf; +}; + +static int grab_nth_branch_switch(struct object_id *ooid, struct object_id *noid, + const char *email, timestamp_t 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_oid_mb(const char *name, struct object_id *oid) +{ + struct commit *one, *two; + struct commit_list *mbs; + struct object_id oid_tmp; + const char *dots; + int st; + + dots = strstr(name, "..."); + if (!dots) + return get_oid(name, oid); + if (dots == name) + st = get_oid("HEAD", &oid_tmp); + else { + struct strbuf sb; + strbuf_init(&sb, dots - name); + strbuf_add(&sb, name, dots - name); + st = get_oid_committish(sb.buf, &oid_tmp); + strbuf_release(&sb); + } + if (st) + return st; + one = lookup_commit_reference_gently(&oid_tmp, 0); + if (!one) + return -1; + + if (get_oid_committish(dots[3] ? (dots + 3) : "HEAD", &oid_tmp)) + return -1; + two = lookup_commit_reference_gently(&oid_tmp, 0); + if (!two) + return -1; + mbs = get_merge_bases(one, two); + if (!mbs || mbs->next) + st = -1; + else { + st = 0; + oidcpy(oid, &mbs->item->object.oid); + } + 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, unsigned allowed) +{ + /* 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, allowed); + /* 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 int branch_interpret_allowed(const char *refname, unsigned allowed) +{ + if (!allowed) + return 1; + + if ((allowed & INTERPRET_BRANCH_LOCAL) && + starts_with(refname, "refs/heads/")) + return 1; + if ((allowed & INTERPRET_BRANCH_REMOTE) && + starts_with(refname, "refs/remotes/")) + return 1; + + return 0; +} + +static int interpret_branch_mark(const char *name, int namelen, + int at, struct strbuf *buf, + int (*get_mark)(const char *, int), + const char *(*get_data)(struct branch *, + struct strbuf *), + unsigned allowed) +{ + int len; + struct branch *branch; + struct strbuf err = STRBUF_INIT; + const char *value; + + len = get_mark(name + at, namelen - at); + if (!len) + return -1; + + if (memchr(name, ':', at)) + return -1; + + if (at) { + char *name_str = xmemdupz(name, at); + branch = branch_get(name_str); + free(name_str); + } else + branch = branch_get(NULL); + + value = get_data(branch, &err); + if (!value) + die("%s", err.buf); + + if (!branch_interpret_allowed(value, allowed)) + return -1; + + set_shortened_ref(buf, value); + return len + at; +} + +int interpret_branch_name(const char *name, int namelen, struct strbuf *buf, + unsigned allowed) +{ + char *at; + const char *start; + int len; + + if (!namelen) + namelen = strlen(name); + + if (!allowed || (allowed & INTERPRET_BRANCH_LOCAL)) { + len = interpret_nth_prior_checkout(name, namelen, buf); + 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, allowed); + } + } + + for (start = name; + (at = memchr(start, '@', namelen - (start - name))); + start = at + 1) { + + if (!allowed || (allowed & INTERPRET_BRANCH_HEAD)) { + len = interpret_empty_at(name, namelen, at - name, buf); + if (len > 0) + return reinterpret(name, namelen, len, buf, + allowed); + } + + len = interpret_branch_mark(name, namelen, at - name, buf, + upstream_mark, branch_get_upstream, + allowed); + if (len > 0) + return len; + + len = interpret_branch_mark(name, namelen, at - name, buf, + push_mark, branch_get_push, + allowed); + if (len > 0) + return len; + } + + return -1; +} + +void strbuf_branchname(struct strbuf *sb, const char *name, unsigned allowed) +{ + int len = strlen(name); + int used = interpret_branch_name(name, len, sb, allowed); + + if (used < 0) + used = 0; + strbuf_add(sb, name + used, len - used); +} + +int strbuf_check_branch_ref(struct strbuf *sb, const char *name) +{ + if (startup_info->have_repository) + strbuf_branchname(sb, name, INTERPRET_BRANCH_LOCAL); + else + strbuf_addstr(sb, name); + + /* + * This splice must be done even if we end up rejecting the + * name; builtin/branch.c::copy_or_rename_branch() still wants + * to see what the name expanded to so that "branch -m" can be + * used as a tool to correct earlier mistakes. + */ + strbuf_splice(sb, 0, 0, "refs/heads/", 11); + + if (*name == '-' || + !strcmp(sb->buf, "refs/heads/HEAD")) + return -1; + + return check_refname_format(sb->buf, 0); +} + +/* + * This is like "get_oid_basic()", except it allows "object ID expressions", + * notably "xyz^" for "parent of xyz" + */ +int get_oid(const char *name, struct object_id *oid) +{ + struct object_context unused; + return get_oid_with_context(name, 0, oid, &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_oid_committish(const char *name, struct object_id *oid) +{ + struct object_context unused; + return get_oid_with_context(name, GET_OID_COMMITTISH, + oid, &unused); +} + +int get_oid_treeish(const char *name, struct object_id *oid) +{ + struct object_context unused; + return get_oid_with_context(name, GET_OID_TREEISH, + oid, &unused); +} + +int get_oid_commit(const char *name, struct object_id *oid) +{ + struct object_context unused; + return get_oid_with_context(name, GET_OID_COMMIT, + oid, &unused); +} + +int get_oid_tree(const char *name, struct object_id *oid) +{ + struct object_context unused; + return get_oid_with_context(name, GET_OID_TREE, + oid, &unused); +} + +int get_oid_blob(const char *name, struct object_id *oid) +{ + struct object_context unused; + return get_oid_with_context(name, GET_OID_BLOB, + oid, &unused); +} + +/* Must be called only when object_name:filename doesn't exist. */ +static void diagnose_invalid_oid_path(const char *prefix, + const char *filename, + const struct object_id *tree_oid, + const char *object_name, + int object_name_len) +{ + struct object_id oid; + unsigned mode; + + if (!prefix) + prefix = ""; + + if (file_exists(filename)) + die("Path '%s' exists on disk, but not in '%.*s'.", + filename, object_name_len, object_name); + if (is_missing_file_error(errno)) { + char *fullname = xstrfmt("%s%s", prefix, filename); + + if (!get_tree_entry(tree_oid, fullname, &oid, &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) +{ + const struct cache_entry *ce; + int pos; + unsigned namelen = strlen(filename); + struct strbuf fullname = STRBUF_INIT; + + 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? */ + strbuf_addstr(&fullname, prefix); + strbuf_addstr(&fullname, filename); + pos = cache_name_pos(fullname.buf, fullname.len); + if (pos < 0) + pos = -pos - 1; + if (pos < active_nr) { + ce = active_cache[pos]; + if (ce_namelen(ce) == fullname.len && + !memcmp(ce->name, fullname.buf, fullname.len)) + die("Path '%s' is in the index, but not '%s'.\n" + "Did you mean ':%d:%s' aka ':%d:./%s'?", + fullname.buf, filename, + ce_stage(ce), fullname.buf, + ce_stage(ce), filename); + } + + if (file_exists(filename)) + die("Path '%s' exists on disk, but not in the index.", filename); + if (is_missing_file_error(errno)) + die("Path '%s' does not exist (neither on disk nor in the index).", + filename); + + strbuf_release(&fullname); +} + + +static char *resolve_relative_path(const char *rel) +{ + if (!starts_with(rel, "./") && !starts_with(rel, "../")) + return NULL; + + 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_oid_with_context_1(const char *name, + unsigned flags, + const char *prefix, + struct object_id *oid, + struct object_context *oc) +{ + int ret, bracket_depth; + int namelen = strlen(name); + const char *cp; + int only_to_die = flags & GET_OID_ONLY_TO_DIE; + + if (only_to_die) + flags |= GET_OID_QUIETLY; + + memset(oc, 0, sizeof(*oc)); + oc->mode = S_IFINVALID; + strbuf_init(&oc->symlink_path, 0); + ret = get_oid_1(name, namelen, oid, 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_oid_oneline(name + 2, oid, 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); + } + + if (flags & GET_OID_RECORD_PATH) + oc->path = xstrdup(cp); + + 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) { + oidcpy(oid, &ce->oid); + 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 == ':') { + struct object_id tree_oid; + int len = cp - name; + unsigned sub_flags = flags; + + sub_flags &= ~GET_OID_DISAMBIGUATORS; + sub_flags |= GET_OID_TREEISH; + + if (!get_oid_1(name, len, &tree_oid, sub_flags)) { + const char *filename = cp+1; + char *new_filename = NULL; + + new_filename = resolve_relative_path(filename); + if (new_filename) + filename = new_filename; + if (flags & GET_OID_FOLLOW_SYMLINKS) { + ret = get_tree_entry_follow_symlinks(&tree_oid, + filename, oid, &oc->symlink_path, + &oc->mode); + } else { + ret = get_tree_entry(&tree_oid, filename, oid, + &oc->mode); + if (ret && only_to_die) { + diagnose_invalid_oid_path(prefix, + filename, + &tree_oid, + name, len); + } + } + if (flags & GET_OID_RECORD_PATH) + oc->path = xstrdup(filename); + + 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; + struct object_id oid; + get_oid_with_context_1(name, GET_OID_ONLY_TO_DIE, prefix, &oid, &oc); +} + +int get_oid_with_context(const char *str, unsigned flags, struct object_id *oid, struct object_context *oc) +{ + if (flags & GET_OID_FOLLOW_SYMLINKS && flags & GET_OID_ONLY_TO_DIE) + BUG("incompatible flags for get_sha1_with_context"); + return get_oid_with_context_1(str, flags, NULL, oid, oc); +} |