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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-07 14:47:53 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-07 14:47:53 +0000
commitc8bae7493d2f2910b57f13ded012e86bdcfb0532 (patch)
tree24e09d9f84dec336720cf393e156089ca2835791 /tree-walk.c
parentInitial commit. (diff)
downloadgit-c8bae7493d2f2910b57f13ded012e86bdcfb0532.tar.xz
git-c8bae7493d2f2910b57f13ded012e86bdcfb0532.zip
Adding upstream version 1:2.39.2.upstream/1%2.39.2upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to '')
-rw-r--r--tree-walk.c1286
1 files changed, 1286 insertions, 0 deletions
diff --git a/tree-walk.c b/tree-walk.c
new file mode 100644
index 0000000..74f4d71
--- /dev/null
+++ b/tree-walk.c
@@ -0,0 +1,1286 @@
+#include "cache.h"
+#include "tree-walk.h"
+#include "dir.h"
+#include "object-store.h"
+#include "tree.h"
+#include "pathspec.h"
+#include "json-writer.h"
+
+static const char *get_mode(const char *str, unsigned int *modep)
+{
+ unsigned char c;
+ unsigned int mode = 0;
+
+ if (*str == ' ')
+ return NULL;
+
+ while ((c = *str++) != ' ') {
+ if (c < '0' || c > '7')
+ return NULL;
+ mode = (mode << 3) + (c - '0');
+ }
+ *modep = mode;
+ return str;
+}
+
+static int decode_tree_entry(struct tree_desc *desc, const char *buf, unsigned long size, struct strbuf *err)
+{
+ const char *path;
+ unsigned int mode, len;
+ const unsigned hashsz = the_hash_algo->rawsz;
+
+ if (size < hashsz + 3 || buf[size - (hashsz + 1)]) {
+ strbuf_addstr(err, _("too-short tree object"));
+ return -1;
+ }
+
+ path = get_mode(buf, &mode);
+ if (!path) {
+ strbuf_addstr(err, _("malformed mode in tree entry"));
+ return -1;
+ }
+ if (!*path) {
+ strbuf_addstr(err, _("empty filename in tree entry"));
+ return -1;
+ }
+ len = strlen(path) + 1;
+
+ /* Initialize the descriptor entry */
+ desc->entry.path = path;
+ desc->entry.mode = (desc->flags & TREE_DESC_RAW_MODES) ? mode : canon_mode(mode);
+ desc->entry.pathlen = len - 1;
+ oidread(&desc->entry.oid, (const unsigned char *)path + len);
+
+ return 0;
+}
+
+static int init_tree_desc_internal(struct tree_desc *desc, const void *buffer,
+ unsigned long size, struct strbuf *err,
+ enum tree_desc_flags flags)
+{
+ desc->buffer = buffer;
+ desc->size = size;
+ desc->flags = flags;
+ if (size)
+ return decode_tree_entry(desc, buffer, size, err);
+ return 0;
+}
+
+void init_tree_desc(struct tree_desc *desc, const void *buffer, unsigned long size)
+{
+ struct strbuf err = STRBUF_INIT;
+ if (init_tree_desc_internal(desc, buffer, size, &err, 0))
+ die("%s", err.buf);
+ strbuf_release(&err);
+}
+
+int init_tree_desc_gently(struct tree_desc *desc, const void *buffer, unsigned long size,
+ enum tree_desc_flags flags)
+{
+ struct strbuf err = STRBUF_INIT;
+ int result = init_tree_desc_internal(desc, buffer, size, &err, flags);
+ if (result)
+ error("%s", err.buf);
+ strbuf_release(&err);
+ return result;
+}
+
+void *fill_tree_descriptor(struct repository *r,
+ struct tree_desc *desc,
+ const struct object_id *oid)
+{
+ unsigned long size = 0;
+ void *buf = NULL;
+
+ if (oid) {
+ buf = read_object_with_reference(r, oid, OBJ_TREE, &size, NULL);
+ if (!buf)
+ die("unable to read tree %s", oid_to_hex(oid));
+ }
+ init_tree_desc(desc, buf, size);
+ return buf;
+}
+
+static void entry_clear(struct name_entry *a)
+{
+ memset(a, 0, sizeof(*a));
+}
+
+static void entry_extract(struct tree_desc *t, struct name_entry *a)
+{
+ *a = t->entry;
+}
+
+static int update_tree_entry_internal(struct tree_desc *desc, struct strbuf *err)
+{
+ const void *buf = desc->buffer;
+ const unsigned char *end = (const unsigned char *)desc->entry.path + desc->entry.pathlen + 1 + the_hash_algo->rawsz;
+ unsigned long size = desc->size;
+ unsigned long len = end - (const unsigned char *)buf;
+
+ if (size < len)
+ die(_("too-short tree file"));
+ buf = end;
+ size -= len;
+ desc->buffer = buf;
+ desc->size = size;
+ if (size)
+ return decode_tree_entry(desc, buf, size, err);
+ return 0;
+}
+
+void update_tree_entry(struct tree_desc *desc)
+{
+ struct strbuf err = STRBUF_INIT;
+ if (update_tree_entry_internal(desc, &err))
+ die("%s", err.buf);
+ strbuf_release(&err);
+}
+
+int update_tree_entry_gently(struct tree_desc *desc)
+{
+ struct strbuf err = STRBUF_INIT;
+ if (update_tree_entry_internal(desc, &err)) {
+ error("%s", err.buf);
+ strbuf_release(&err);
+ /* Stop processing this tree after error */
+ desc->size = 0;
+ return -1;
+ }
+ strbuf_release(&err);
+ return 0;
+}
+
+int tree_entry(struct tree_desc *desc, struct name_entry *entry)
+{
+ if (!desc->size)
+ return 0;
+
+ *entry = desc->entry;
+ update_tree_entry(desc);
+ return 1;
+}
+
+int tree_entry_gently(struct tree_desc *desc, struct name_entry *entry)
+{
+ if (!desc->size)
+ return 0;
+
+ *entry = desc->entry;
+ if (update_tree_entry_gently(desc))
+ return 0;
+ return 1;
+}
+
+static int traverse_trees_atexit_registered;
+static int traverse_trees_count;
+static int traverse_trees_cur_depth;
+static int traverse_trees_max_depth;
+
+static void trace2_traverse_trees_statistics_atexit(void)
+{
+ struct json_writer jw = JSON_WRITER_INIT;
+
+ jw_object_begin(&jw, 0);
+ jw_object_intmax(&jw, "traverse_trees_count", traverse_trees_count);
+ jw_object_intmax(&jw, "traverse_trees_max_depth", traverse_trees_max_depth);
+ jw_end(&jw);
+
+ trace2_data_json("traverse_trees", the_repository, "statistics", &jw);
+
+ jw_release(&jw);
+}
+
+void setup_traverse_info(struct traverse_info *info, const char *base)
+{
+ size_t pathlen = strlen(base);
+ static struct traverse_info dummy;
+
+ memset(info, 0, sizeof(*info));
+ if (pathlen && base[pathlen-1] == '/')
+ pathlen--;
+ info->pathlen = pathlen ? pathlen + 1 : 0;
+ info->name = base;
+ info->namelen = pathlen;
+ if (pathlen)
+ info->prev = &dummy;
+
+ if (trace2_is_enabled() && !traverse_trees_atexit_registered) {
+ atexit(trace2_traverse_trees_statistics_atexit);
+ traverse_trees_atexit_registered = 1;
+ }
+}
+
+char *make_traverse_path(char *path, size_t pathlen,
+ const struct traverse_info *info,
+ const char *name, size_t namelen)
+{
+ /* Always points to the end of the name we're about to add */
+ size_t pos = st_add(info->pathlen, namelen);
+
+ if (pos >= pathlen)
+ BUG("too small buffer passed to make_traverse_path");
+
+ path[pos] = 0;
+ for (;;) {
+ if (pos < namelen)
+ BUG("traverse_info pathlen does not match strings");
+ pos -= namelen;
+ memcpy(path + pos, name, namelen);
+
+ if (!pos)
+ break;
+ path[--pos] = '/';
+
+ if (!info)
+ BUG("traverse_info ran out of list items");
+ name = info->name;
+ namelen = info->namelen;
+ info = info->prev;
+ }
+ return path;
+}
+
+void strbuf_make_traverse_path(struct strbuf *out,
+ const struct traverse_info *info,
+ const char *name, size_t namelen)
+{
+ size_t len = traverse_path_len(info, namelen);
+
+ strbuf_grow(out, len);
+ make_traverse_path(out->buf + out->len, out->alloc - out->len,
+ info, name, namelen);
+ strbuf_setlen(out, out->len + len);
+}
+
+struct tree_desc_skip {
+ struct tree_desc_skip *prev;
+ const void *ptr;
+};
+
+struct tree_desc_x {
+ struct tree_desc d;
+ struct tree_desc_skip *skip;
+};
+
+static int check_entry_match(const char *a, int a_len, const char *b, int b_len)
+{
+ /*
+ * The caller wants to pick *a* from a tree or nothing.
+ * We are looking at *b* in a tree.
+ *
+ * (0) If a and b are the same name, we are trivially happy.
+ *
+ * There are three possibilities where *a* could be hiding
+ * behind *b*.
+ *
+ * (1) *a* == "t", *b* == "ab" i.e. *b* sorts earlier than *a* no
+ * matter what.
+ * (2) *a* == "t", *b* == "t-2" and "t" is a subtree in the tree;
+ * (3) *a* == "t-2", *b* == "t" and "t-2" is a blob in the tree.
+ *
+ * Otherwise we know *a* won't appear in the tree without
+ * scanning further.
+ */
+
+ int cmp = name_compare(a, a_len, b, b_len);
+
+ /* Most common case first -- reading sync'd trees */
+ if (!cmp)
+ return cmp;
+
+ if (0 < cmp) {
+ /* a comes after b; it does not matter if it is case (3)
+ if (b_len < a_len && !memcmp(a, b, b_len) && a[b_len] < '/')
+ return 1;
+ */
+ return 1; /* keep looking */
+ }
+
+ /* b comes after a; are we looking at case (2)? */
+ if (a_len < b_len && !memcmp(a, b, a_len) && b[a_len] < '/')
+ return 1; /* keep looking */
+
+ return -1; /* a cannot appear in the tree */
+}
+
+/*
+ * From the extended tree_desc, extract the first name entry, while
+ * paying attention to the candidate "first" name. Most importantly,
+ * when looking for an entry, if there are entries that sorts earlier
+ * in the tree object representation than that name, skip them and
+ * process the named entry first. We will remember that we haven't
+ * processed the first entry yet, and in the later call skip the
+ * entry we processed early when update_extended_entry() is called.
+ *
+ * E.g. if the underlying tree object has these entries:
+ *
+ * blob "t-1"
+ * blob "t-2"
+ * tree "t"
+ * blob "t=1"
+ *
+ * and the "first" asks for "t", remember that we still need to
+ * process "t-1" and "t-2" but extract "t". After processing the
+ * entry "t" from this call, the caller will let us know by calling
+ * update_extended_entry() that we can remember "t" has been processed
+ * already.
+ */
+
+static void extended_entry_extract(struct tree_desc_x *t,
+ struct name_entry *a,
+ const char *first,
+ int first_len)
+{
+ const char *path;
+ int len;
+ struct tree_desc probe;
+ struct tree_desc_skip *skip;
+
+ /*
+ * Extract the first entry from the tree_desc, but skip the
+ * ones that we already returned in earlier rounds.
+ */
+ while (1) {
+ if (!t->d.size) {
+ entry_clear(a);
+ break; /* not found */
+ }
+ entry_extract(&t->d, a);
+ for (skip = t->skip; skip; skip = skip->prev)
+ if (a->path == skip->ptr)
+ break; /* found */
+ if (!skip)
+ break;
+ /* We have processed this entry already. */
+ update_tree_entry(&t->d);
+ }
+
+ if (!first || !a->path)
+ return;
+
+ /*
+ * The caller wants "first" from this tree, or nothing.
+ */
+ path = a->path;
+ len = tree_entry_len(a);
+ switch (check_entry_match(first, first_len, path, len)) {
+ case -1:
+ entry_clear(a);
+ case 0:
+ return;
+ default:
+ break;
+ }
+
+ /*
+ * We need to look-ahead -- we suspect that a subtree whose
+ * name is "first" may be hiding behind the current entry "path".
+ */
+ probe = t->d;
+ while (probe.size) {
+ entry_extract(&probe, a);
+ path = a->path;
+ len = tree_entry_len(a);
+ switch (check_entry_match(first, first_len, path, len)) {
+ case -1:
+ entry_clear(a);
+ case 0:
+ return;
+ default:
+ update_tree_entry(&probe);
+ break;
+ }
+ /* keep looking */
+ }
+ entry_clear(a);
+}
+
+static void update_extended_entry(struct tree_desc_x *t, struct name_entry *a)
+{
+ if (t->d.entry.path == a->path) {
+ update_tree_entry(&t->d);
+ } else {
+ /* we have returned this entry early */
+ struct tree_desc_skip *skip = xmalloc(sizeof(*skip));
+ skip->ptr = a->path;
+ skip->prev = t->skip;
+ t->skip = skip;
+ }
+}
+
+static void free_extended_entry(struct tree_desc_x *t)
+{
+ struct tree_desc_skip *p, *s;
+
+ for (s = t->skip; s; s = p) {
+ p = s->prev;
+ free(s);
+ }
+}
+
+static inline int prune_traversal(struct index_state *istate,
+ struct name_entry *e,
+ struct traverse_info *info,
+ struct strbuf *base,
+ int still_interesting)
+{
+ if (!info->pathspec || still_interesting == 2)
+ return 2;
+ if (still_interesting < 0)
+ return still_interesting;
+ return tree_entry_interesting(istate, e, base,
+ 0, info->pathspec);
+}
+
+int traverse_trees(struct index_state *istate,
+ int n, struct tree_desc *t,
+ struct traverse_info *info)
+{
+ int error = 0;
+ struct name_entry entry[MAX_TRAVERSE_TREES];
+ int i;
+ struct tree_desc_x tx[ARRAY_SIZE(entry)];
+ struct strbuf base = STRBUF_INIT;
+ int interesting = 1;
+ char *traverse_path;
+
+ traverse_trees_count++;
+ traverse_trees_cur_depth++;
+
+ if (traverse_trees_cur_depth > traverse_trees_max_depth)
+ traverse_trees_max_depth = traverse_trees_cur_depth;
+
+ if (n >= ARRAY_SIZE(entry))
+ BUG("traverse_trees() called with too many trees (%d)", n);
+
+ for (i = 0; i < n; i++) {
+ tx[i].d = t[i];
+ tx[i].skip = NULL;
+ }
+
+ if (info->prev) {
+ strbuf_make_traverse_path(&base, info->prev,
+ info->name, info->namelen);
+ strbuf_addch(&base, '/');
+ traverse_path = xstrndup(base.buf, base.len);
+ } else {
+ traverse_path = xstrndup(info->name, info->pathlen);
+ }
+ info->traverse_path = traverse_path;
+ for (;;) {
+ int trees_used;
+ unsigned long mask, dirmask;
+ const char *first = NULL;
+ int first_len = 0;
+ struct name_entry *e = NULL;
+ int len;
+
+ for (i = 0; i < n; i++) {
+ e = entry + i;
+ extended_entry_extract(tx + i, e, NULL, 0);
+ }
+
+ /*
+ * A tree may have "t-2" at the current location even
+ * though it may have "t" that is a subtree behind it,
+ * and another tree may return "t". We want to grab
+ * all "t" from all trees to match in such a case.
+ */
+ for (i = 0; i < n; i++) {
+ e = entry + i;
+ if (!e->path)
+ continue;
+ len = tree_entry_len(e);
+ if (!first) {
+ first = e->path;
+ first_len = len;
+ continue;
+ }
+ if (name_compare(e->path, len, first, first_len) < 0) {
+ first = e->path;
+ first_len = len;
+ }
+ }
+
+ if (first) {
+ for (i = 0; i < n; i++) {
+ e = entry + i;
+ extended_entry_extract(tx + i, e, first, first_len);
+ /* Cull the ones that are not the earliest */
+ if (!e->path)
+ continue;
+ len = tree_entry_len(e);
+ if (name_compare(e->path, len, first, first_len))
+ entry_clear(e);
+ }
+ }
+
+ /* Now we have in entry[i] the earliest name from the trees */
+ mask = 0;
+ dirmask = 0;
+ for (i = 0; i < n; i++) {
+ if (!entry[i].path)
+ continue;
+ mask |= 1ul << i;
+ if (S_ISDIR(entry[i].mode))
+ dirmask |= 1ul << i;
+ e = &entry[i];
+ }
+ if (!mask)
+ break;
+ interesting = prune_traversal(istate, e, info, &base, interesting);
+ if (interesting < 0)
+ break;
+ if (interesting) {
+ trees_used = info->fn(n, mask, dirmask, entry, info);
+ if (trees_used < 0) {
+ error = trees_used;
+ if (!info->show_all_errors)
+ break;
+ }
+ mask &= trees_used;
+ }
+ for (i = 0; i < n; i++)
+ if (mask & (1ul << i))
+ update_extended_entry(tx + i, entry + i);
+ }
+ for (i = 0; i < n; i++)
+ free_extended_entry(tx + i);
+ free(traverse_path);
+ info->traverse_path = NULL;
+ strbuf_release(&base);
+
+ traverse_trees_cur_depth--;
+ return error;
+}
+
+struct dir_state {
+ void *tree;
+ unsigned long size;
+ struct object_id oid;
+};
+
+static int find_tree_entry(struct repository *r, struct tree_desc *t,
+ const char *name, struct object_id *result,
+ unsigned short *mode)
+{
+ int namelen = strlen(name);
+ while (t->size) {
+ const char *entry;
+ struct object_id oid;
+ int entrylen, cmp;
+
+ oidcpy(&oid, tree_entry_extract(t, &entry, mode));
+ entrylen = tree_entry_len(&t->entry);
+ update_tree_entry(t);
+ if (entrylen > namelen)
+ continue;
+ cmp = memcmp(name, entry, entrylen);
+ if (cmp > 0)
+ continue;
+ if (cmp < 0)
+ break;
+ if (entrylen == namelen) {
+ oidcpy(result, &oid);
+ return 0;
+ }
+ if (name[entrylen] != '/')
+ continue;
+ if (!S_ISDIR(*mode))
+ break;
+ if (++entrylen == namelen) {
+ oidcpy(result, &oid);
+ return 0;
+ }
+ return get_tree_entry(r, &oid, name + entrylen, result, mode);
+ }
+ return -1;
+}
+
+int get_tree_entry(struct repository *r,
+ const struct object_id *tree_oid,
+ const char *name,
+ struct object_id *oid,
+ unsigned short *mode)
+{
+ int retval;
+ void *tree;
+ unsigned long size;
+ struct object_id root;
+
+ tree = read_object_with_reference(r, tree_oid, OBJ_TREE, &size, &root);
+ if (!tree)
+ return -1;
+
+ if (name[0] == '\0') {
+ oidcpy(oid, &root);
+ free(tree);
+ return 0;
+ }
+
+ if (!size) {
+ retval = -1;
+ } else {
+ struct tree_desc t;
+ init_tree_desc(&t, tree, size);
+ retval = find_tree_entry(r, &t, name, oid, mode);
+ }
+ free(tree);
+ return retval;
+}
+
+/*
+ * This is Linux's built-in max for the number of symlinks to follow.
+ * That limit, of course, does not affect git, but it's a reasonable
+ * choice.
+ */
+#define GET_TREE_ENTRY_FOLLOW_SYMLINKS_MAX_LINKS 40
+
+/**
+ * Find a tree entry by following symlinks in tree_sha (which is
+ * assumed to be the root of the repository). In the event that a
+ * symlink points outside the repository (e.g. a link to /foo or a
+ * root-level link to ../foo), the portion of the link which is
+ * outside the repository will be returned in result_path, and *mode
+ * will be set to 0. It is assumed that result_path is uninitialized.
+ * If there are no symlinks, or the end result of the symlink chain
+ * points to an object inside the repository, result will be filled in
+ * with the sha1 of the found object, and *mode will hold the mode of
+ * the object.
+ *
+ * See the code for enum get_oid_result for a description of
+ * the return values.
+ */
+enum get_oid_result get_tree_entry_follow_symlinks(struct repository *r,
+ struct object_id *tree_oid, const char *name,
+ struct object_id *result, struct strbuf *result_path,
+ unsigned short *mode)
+{
+ int retval = MISSING_OBJECT;
+ struct dir_state *parents = NULL;
+ size_t parents_alloc = 0;
+ size_t i, parents_nr = 0;
+ struct object_id current_tree_oid;
+ struct strbuf namebuf = STRBUF_INIT;
+ struct tree_desc t;
+ int follows_remaining = GET_TREE_ENTRY_FOLLOW_SYMLINKS_MAX_LINKS;
+
+ init_tree_desc(&t, NULL, 0UL);
+ strbuf_addstr(&namebuf, name);
+ oidcpy(&current_tree_oid, tree_oid);
+
+ while (1) {
+ int find_result;
+ char *first_slash;
+ char *remainder = NULL;
+
+ if (!t.buffer) {
+ void *tree;
+ struct object_id root;
+ unsigned long size;
+ tree = read_object_with_reference(r,
+ &current_tree_oid,
+ OBJ_TREE, &size,
+ &root);
+ if (!tree)
+ goto done;
+
+ ALLOC_GROW(parents, parents_nr + 1, parents_alloc);
+ parents[parents_nr].tree = tree;
+ parents[parents_nr].size = size;
+ oidcpy(&parents[parents_nr].oid, &root);
+ parents_nr++;
+
+ if (namebuf.buf[0] == '\0') {
+ oidcpy(result, &root);
+ retval = FOUND;
+ goto done;
+ }
+
+ if (!size)
+ goto done;
+
+ /* descend */
+ init_tree_desc(&t, tree, size);
+ }
+
+ /* Handle symlinks to e.g. a//b by removing leading slashes */
+ while (namebuf.buf[0] == '/') {
+ strbuf_remove(&namebuf, 0, 1);
+ }
+
+ /* Split namebuf into a first component and a remainder */
+ if ((first_slash = strchr(namebuf.buf, '/'))) {
+ *first_slash = 0;
+ remainder = first_slash + 1;
+ }
+
+ if (!strcmp(namebuf.buf, "..")) {
+ struct dir_state *parent;
+ /*
+ * We could end up with .. in the namebuf if it
+ * appears in a symlink.
+ */
+
+ if (parents_nr == 1) {
+ if (remainder)
+ *first_slash = '/';
+ strbuf_add(result_path, namebuf.buf,
+ namebuf.len);
+ *mode = 0;
+ retval = FOUND;
+ goto done;
+ }
+ parent = &parents[parents_nr - 1];
+ free(parent->tree);
+ parents_nr--;
+ parent = &parents[parents_nr - 1];
+ init_tree_desc(&t, parent->tree, parent->size);
+ strbuf_remove(&namebuf, 0, remainder ? 3 : 2);
+ continue;
+ }
+
+ /* We could end up here via a symlink to dir/.. */
+ if (namebuf.buf[0] == '\0') {
+ oidcpy(result, &parents[parents_nr - 1].oid);
+ retval = FOUND;
+ goto done;
+ }
+
+ /* Look up the first (or only) path component in the tree. */
+ find_result = find_tree_entry(r, &t, namebuf.buf,
+ &current_tree_oid, mode);
+ if (find_result) {
+ goto done;
+ }
+
+ if (S_ISDIR(*mode)) {
+ if (!remainder) {
+ oidcpy(result, &current_tree_oid);
+ retval = FOUND;
+ goto done;
+ }
+ /* Descend the tree */
+ t.buffer = NULL;
+ strbuf_remove(&namebuf, 0,
+ 1 + first_slash - namebuf.buf);
+ } else if (S_ISREG(*mode)) {
+ if (!remainder) {
+ oidcpy(result, &current_tree_oid);
+ retval = FOUND;
+ } else {
+ retval = NOT_DIR;
+ }
+ goto done;
+ } else if (S_ISLNK(*mode)) {
+ /* Follow a symlink */
+ unsigned long link_len;
+ size_t len;
+ char *contents, *contents_start;
+ struct dir_state *parent;
+ enum object_type type;
+
+ if (follows_remaining-- == 0) {
+ /* Too many symlinks followed */
+ retval = SYMLINK_LOOP;
+ goto done;
+ }
+
+ /*
+ * At this point, we have followed at a least
+ * one symlink, so on error we need to report this.
+ */
+ retval = DANGLING_SYMLINK;
+
+ contents = repo_read_object_file(r,
+ &current_tree_oid, &type,
+ &link_len);
+
+ if (!contents)
+ goto done;
+
+ if (contents[0] == '/') {
+ strbuf_addstr(result_path, contents);
+ free(contents);
+ *mode = 0;
+ retval = FOUND;
+ goto done;
+ }
+
+ if (remainder)
+ len = first_slash - namebuf.buf;
+ else
+ len = namebuf.len;
+
+ contents_start = contents;
+
+ parent = &parents[parents_nr - 1];
+ init_tree_desc(&t, parent->tree, parent->size);
+ strbuf_splice(&namebuf, 0, len,
+ contents_start, link_len);
+ if (remainder)
+ namebuf.buf[link_len] = '/';
+ free(contents);
+ }
+ }
+done:
+ for (i = 0; i < parents_nr; i++)
+ free(parents[i].tree);
+ free(parents);
+
+ strbuf_release(&namebuf);
+ return retval;
+}
+
+static int match_entry(const struct pathspec_item *item,
+ const struct name_entry *entry, int pathlen,
+ const char *match, int matchlen,
+ enum interesting *never_interesting)
+{
+ int m = -1; /* signals that we haven't called strncmp() */
+
+ if (item->magic & PATHSPEC_ICASE)
+ /*
+ * "Never interesting" trick requires exact
+ * matching. We could do something clever with inexact
+ * matching, but it's trickier (and not to forget that
+ * strcasecmp is locale-dependent, at least in
+ * glibc). Just disable it for now. It can't be worse
+ * than the wildcard's codepath of '[Tt][Hi][Is][Ss]'
+ * pattern.
+ */
+ *never_interesting = entry_not_interesting;
+ else if (*never_interesting != entry_not_interesting) {
+ /*
+ * We have not seen any match that sorts later
+ * than the current path.
+ */
+
+ /*
+ * Does match sort strictly earlier than path
+ * with their common parts?
+ */
+ m = strncmp(match, entry->path,
+ (matchlen < pathlen) ? matchlen : pathlen);
+ if (m < 0)
+ return 0;
+
+ /*
+ * If we come here even once, that means there is at
+ * least one pathspec that would sort equal to or
+ * later than the path we are currently looking at.
+ * In other words, if we have never reached this point
+ * after iterating all pathspecs, it means all
+ * pathspecs are either outside of base, or inside the
+ * base but sorts strictly earlier than the current
+ * one. In either case, they will never match the
+ * subsequent entries. In such a case, we initialized
+ * the variable to -1 and that is what will be
+ * returned, allowing the caller to terminate early.
+ */
+ *never_interesting = entry_not_interesting;
+ }
+
+ if (pathlen > matchlen)
+ return 0;
+
+ if (matchlen > pathlen) {
+ if (match[pathlen] != '/')
+ return 0;
+ /*
+ * Reject non-directories as partial pathnames, except
+ * when match is a submodule with a trailing slash and
+ * nothing else (to handle 'submod/' and 'submod'
+ * uniformly).
+ */
+ if (!S_ISDIR(entry->mode) &&
+ (!S_ISGITLINK(entry->mode) || matchlen > pathlen + 1))
+ return 0;
+ }
+
+ if (m == -1)
+ /*
+ * we cheated and did not do strncmp(), so we do
+ * that here.
+ */
+ m = ps_strncmp(item, match, entry->path, pathlen);
+
+ /*
+ * If common part matched earlier then it is a hit,
+ * because we rejected the case where path is not a
+ * leading directory and is shorter than match.
+ */
+ if (!m)
+ /*
+ * match_entry does not check if the prefix part is
+ * matched case-sensitively. If the entry is a
+ * directory and part of prefix, it'll be rematched
+ * eventually by basecmp with special treatment for
+ * the prefix.
+ */
+ return 1;
+
+ return 0;
+}
+
+/* :(icase)-aware string compare */
+static int basecmp(const struct pathspec_item *item,
+ const char *base, const char *match, int len)
+{
+ if (item->magic & PATHSPEC_ICASE) {
+ int ret, n = len > item->prefix ? item->prefix : len;
+ ret = strncmp(base, match, n);
+ if (ret)
+ return ret;
+ base += n;
+ match += n;
+ len -= n;
+ }
+ return ps_strncmp(item, base, match, len);
+}
+
+static int match_dir_prefix(const struct pathspec_item *item,
+ const char *base,
+ const char *match, int matchlen)
+{
+ if (basecmp(item, base, match, matchlen))
+ return 0;
+
+ /*
+ * If the base is a subdirectory of a path which
+ * was specified, all of them are interesting.
+ */
+ if (!matchlen ||
+ base[matchlen] == '/' ||
+ match[matchlen - 1] == '/')
+ return 1;
+
+ /* Just a random prefix match */
+ return 0;
+}
+
+/*
+ * Perform matching on the leading non-wildcard part of
+ * pathspec. item->nowildcard_len must be greater than zero. Return
+ * non-zero if base is matched.
+ */
+static int match_wildcard_base(const struct pathspec_item *item,
+ const char *base, int baselen,
+ int *matched)
+{
+ const char *match = item->match;
+ /* the wildcard part is not considered in this function */
+ int matchlen = item->nowildcard_len;
+
+ if (baselen) {
+ int dirlen;
+ /*
+ * Return early if base is longer than the
+ * non-wildcard part but it does not match.
+ */
+ if (baselen >= matchlen) {
+ *matched = matchlen;
+ return !basecmp(item, base, match, matchlen);
+ }
+
+ dirlen = matchlen;
+ while (dirlen && match[dirlen - 1] != '/')
+ dirlen--;
+
+ /*
+ * Return early if base is shorter than the
+ * non-wildcard part but it does not match. Note that
+ * base ends with '/' so we are sure it really matches
+ * directory
+ */
+ if (basecmp(item, base, match, baselen))
+ return 0;
+ *matched = baselen;
+ } else
+ *matched = 0;
+ /*
+ * we could have checked entry against the non-wildcard part
+ * that is not in base and does similar never_interesting
+ * optimization as in match_entry. For now just be happy with
+ * base comparison.
+ */
+ return entry_interesting;
+}
+
+/*
+ * Is a tree entry interesting given the pathspec we have?
+ *
+ * Pre-condition: either baselen == base_offset (i.e. empty path)
+ * or base[baselen-1] == '/' (i.e. with trailing slash).
+ */
+static enum interesting do_match(struct index_state *istate,
+ const struct name_entry *entry,
+ struct strbuf *base, int base_offset,
+ const struct pathspec *ps,
+ int exclude)
+{
+ int i;
+ int pathlen, baselen = base->len - base_offset;
+ enum interesting never_interesting = ps->has_wildcard ?
+ entry_not_interesting : all_entries_not_interesting;
+
+ GUARD_PATHSPEC(ps,
+ PATHSPEC_FROMTOP |
+ PATHSPEC_MAXDEPTH |
+ PATHSPEC_LITERAL |
+ PATHSPEC_GLOB |
+ PATHSPEC_ICASE |
+ PATHSPEC_EXCLUDE |
+ PATHSPEC_ATTR);
+
+ if (!ps->nr) {
+ if (!ps->recursive ||
+ !(ps->magic & PATHSPEC_MAXDEPTH) ||
+ ps->max_depth == -1)
+ return all_entries_interesting;
+ return within_depth(base->buf + base_offset, baselen,
+ !!S_ISDIR(entry->mode),
+ ps->max_depth) ?
+ entry_interesting : entry_not_interesting;
+ }
+
+ pathlen = tree_entry_len(entry);
+
+ for (i = ps->nr - 1; i >= 0; i--) {
+ const struct pathspec_item *item = ps->items+i;
+ const char *match = item->match;
+ const char *base_str = base->buf + base_offset;
+ int matchlen = item->len, matched = 0;
+
+ if ((!exclude && item->magic & PATHSPEC_EXCLUDE) ||
+ ( exclude && !(item->magic & PATHSPEC_EXCLUDE)))
+ continue;
+
+ if (baselen >= matchlen) {
+ /* If it doesn't match, move along... */
+ if (!match_dir_prefix(item, base_str, match, matchlen))
+ goto match_wildcards;
+
+ if (!ps->recursive ||
+ !(ps->magic & PATHSPEC_MAXDEPTH) ||
+ ps->max_depth == -1) {
+ if (!item->attr_match_nr)
+ return all_entries_interesting;
+ else
+ goto interesting;
+ }
+
+ if (within_depth(base_str + matchlen + 1,
+ baselen - matchlen - 1,
+ !!S_ISDIR(entry->mode),
+ ps->max_depth))
+ goto interesting;
+ else
+ return entry_not_interesting;
+ }
+
+ /* Either there must be no base, or the base must match. */
+ if (baselen == 0 || !basecmp(item, base_str, match, baselen)) {
+ if (match_entry(item, entry, pathlen,
+ match + baselen, matchlen - baselen,
+ &never_interesting))
+ goto interesting;
+
+ if (item->nowildcard_len < item->len) {
+ if (!git_fnmatch(item, match + baselen, entry->path,
+ item->nowildcard_len - baselen))
+ goto interesting;
+
+ /*
+ * Match all directories. We'll try to
+ * match files later on.
+ */
+ if (ps->recursive && S_ISDIR(entry->mode))
+ return entry_interesting;
+
+ /*
+ * When matching against submodules with
+ * wildcard characters, ensure that the entry
+ * at least matches up to the first wild
+ * character. More accurate matching can then
+ * be performed in the submodule itself.
+ */
+ if (ps->recurse_submodules &&
+ S_ISGITLINK(entry->mode) &&
+ !ps_strncmp(item, match + baselen,
+ entry->path,
+ item->nowildcard_len - baselen))
+ goto interesting;
+ }
+
+ continue;
+ }
+
+match_wildcards:
+ if (item->nowildcard_len == item->len)
+ continue;
+
+ if (item->nowildcard_len &&
+ !match_wildcard_base(item, base_str, baselen, &matched))
+ continue;
+
+ /*
+ * Concatenate base and entry->path into one and do
+ * fnmatch() on it.
+ *
+ * While we could avoid concatenation in certain cases
+ * [1], which saves a memcpy and potentially a
+ * realloc, it turns out not worth it. Measurement on
+ * linux-2.6 does not show any clear improvements,
+ * partly because of the nowildcard_len optimization
+ * in git_fnmatch(). Avoid micro-optimizations here.
+ *
+ * [1] if match_wildcard_base() says the base
+ * directory is already matched, we only need to match
+ * the rest, which is shorter so _in theory_ faster.
+ */
+
+ strbuf_add(base, entry->path, pathlen);
+
+ if (!git_fnmatch(item, match, base->buf + base_offset,
+ item->nowildcard_len)) {
+ strbuf_setlen(base, base_offset + baselen);
+ goto interesting;
+ }
+
+ /*
+ * When matching against submodules with
+ * wildcard characters, ensure that the entry
+ * at least matches up to the first wild
+ * character. More accurate matching can then
+ * be performed in the submodule itself.
+ */
+ if (ps->recurse_submodules && S_ISGITLINK(entry->mode) &&
+ !ps_strncmp(item, match, base->buf + base_offset,
+ item->nowildcard_len)) {
+ strbuf_setlen(base, base_offset + baselen);
+ goto interesting;
+ }
+
+ strbuf_setlen(base, base_offset + baselen);
+
+ /*
+ * Match all directories. We'll try to match files
+ * later on.
+ * max_depth is ignored but we may consider support it
+ * in future, see
+ * https://lore.kernel.org/git/7vmxo5l2g4.fsf@alter.siamese.dyndns.org/
+ */
+ if (ps->recursive && S_ISDIR(entry->mode))
+ return entry_interesting;
+ continue;
+interesting:
+ if (item->attr_match_nr) {
+ int ret;
+
+ /*
+ * Must not return all_entries_not_interesting
+ * prematurely. We do not know if all entries do not
+ * match some attributes with current attr API.
+ */
+ never_interesting = entry_not_interesting;
+
+ /*
+ * Consider all directories interesting (because some
+ * of those files inside may match some attributes
+ * even though the parent dir does not)
+ *
+ * FIXME: attributes _can_ match directories and we
+ * can probably return all_entries_interesting or
+ * all_entries_not_interesting here if matched.
+ */
+ if (S_ISDIR(entry->mode))
+ return entry_interesting;
+
+ strbuf_add(base, entry->path, pathlen);
+ ret = match_pathspec_attrs(istate, base->buf + base_offset,
+ base->len - base_offset, item);
+ strbuf_setlen(base, base_offset + baselen);
+ if (!ret)
+ continue;
+ }
+ return entry_interesting;
+ }
+ return never_interesting; /* No matches */
+}
+
+/*
+ * Is a tree entry interesting given the pathspec we have?
+ *
+ * Pre-condition: either baselen == base_offset (i.e. empty path)
+ * or base[baselen-1] == '/' (i.e. with trailing slash).
+ */
+enum interesting tree_entry_interesting(struct index_state *istate,
+ const struct name_entry *entry,
+ struct strbuf *base, int base_offset,
+ const struct pathspec *ps)
+{
+ enum interesting positive, negative;
+ positive = do_match(istate, entry, base, base_offset, ps, 0);
+
+ /*
+ * case | entry | positive | negative | result
+ * -----+-------+----------+----------+-------
+ * 1 | file | -1 | -1..2 | -1
+ * 2 | file | 0 | -1..2 | 0
+ * 3 | file | 1 | -1 | 1
+ * 4 | file | 1 | 0 | 1
+ * 5 | file | 1 | 1 | 0
+ * 6 | file | 1 | 2 | 0
+ * 7 | file | 2 | -1 | 2
+ * 8 | file | 2 | 0 | 1
+ * 9 | file | 2 | 1 | 0
+ * 10 | file | 2 | 2 | -1
+ * -----+-------+----------+----------+-------
+ * 11 | dir | -1 | -1..2 | -1
+ * 12 | dir | 0 | -1..2 | 0
+ * 13 | dir | 1 | -1 | 1
+ * 14 | dir | 1 | 0 | 1
+ * 15 | dir | 1 | 1 | 1 (*)
+ * 16 | dir | 1 | 2 | 0
+ * 17 | dir | 2 | -1 | 2
+ * 18 | dir | 2 | 0 | 1
+ * 19 | dir | 2 | 1 | 1 (*)
+ * 20 | dir | 2 | 2 | -1
+ *
+ * (*) An exclude pattern interested in a directory does not
+ * necessarily mean it will exclude all of the directory. In
+ * wildcard case, it can't decide until looking at individual
+ * files inside. So don't write such directories off yet.
+ */
+
+ if (!(ps->magic & PATHSPEC_EXCLUDE) ||
+ positive <= entry_not_interesting) /* #1, #2, #11, #12 */
+ return positive;
+
+ negative = do_match(istate, entry, base, base_offset, ps, 1);
+
+ /* #8, #18 */
+ if (positive == all_entries_interesting &&
+ negative == entry_not_interesting)
+ return entry_interesting;
+
+ /* #3, #4, #7, #13, #14, #17 */
+ if (negative <= entry_not_interesting)
+ return positive;
+
+ /* #15, #19 */
+ if (S_ISDIR(entry->mode) &&
+ positive >= entry_interesting &&
+ negative == entry_interesting)
+ return entry_interesting;
+
+ if ((positive == entry_interesting &&
+ negative >= entry_interesting) || /* #5, #6, #16 */
+ (positive == all_entries_interesting &&
+ negative == entry_interesting)) /* #9 */
+ return entry_not_interesting;
+
+ return all_entries_not_interesting; /* #10, #20 */
+}