tree-walk: support :(attr) matching

This lets us use :(attr) with "git grep <tree-ish>" or "git log".

:(attr) requires another round of checking before we can declare that
a path is matched. This is done after path matching since we have lots
of optimization to take a shortcut when things don't match.

Note that if :(attr) is present, we can't return
all_entries_interesting / all_entries_not_interesting anymore because
we can't be certain about that. Not until match_pathspec_attrs() can
tell us "yes all these paths satisfy :(attr)".

Second note. Even though we walk a specific tree, we use attributes
from _worktree_ (or falling back to the index), not from .gitattributes
files on that tree. This by itself is not necessarily wrong, but the
user just have to be aware of this.

Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

1 files changed, 53 insertions, 14 deletions

diff --git a/tree-walk.c b/tree-walk.c
index 517bcdecf9e..08210a4109c 100644
--- a/tree-walk.c
+++ b/tree-walk.c
@@ -949,7 +949,8 @@ static enum interesting do_match(struct index_state *istate,
 		       PATHSPEC_LITERAL |
 		       PATHSPEC_GLOB |
 		       PATHSPEC_ICASE |
-		       PATHSPEC_EXCLUDE);
+		       PATHSPEC_EXCLUDE |
+		       PATHSPEC_ATTR);
 
 	if (!ps->nr) {
 		if (!ps->recursive ||
@@ -981,14 +982,20 @@ static enum interesting do_match(struct index_state *istate,
 
 			if (!ps->recursive ||
 			    !(ps->magic & PATHSPEC_MAXDEPTH) ||
-			    ps->max_depth == -1)
-				return all_entries_interesting;
-
-			return within_depth(base_str + matchlen + 1,
-					    baselen - matchlen - 1,
-					    !!S_ISDIR(entry->mode),
-					    ps->max_depth) ?
-				entry_interesting : entry_not_interesting;
+			    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. */
@@ -996,12 +1003,12 @@ static enum interesting do_match(struct index_state *istate,
 			if (match_entry(item, entry, pathlen,
 					match + baselen, matchlen - baselen,
 					&never_interesting))
-				return entry_interesting;
+				goto interesting;
 
 			if (item->nowildcard_len < item->len) {
 				if (!git_fnmatch(item, match + baselen, entry->path,
 						 item->nowildcard_len - baselen))
-					return entry_interesting;
+					goto interesting;
 
 				/*
 				 * Match all directories. We'll try to
@@ -1022,7 +1029,7 @@ static enum interesting do_match(struct index_state *istate,
 				    !ps_strncmp(item, match + baselen,
 						entry->path,
 						item->nowildcard_len - baselen))
-					return entry_interesting;
+					goto interesting;
 			}
 
 			continue;
@@ -1057,7 +1064,7 @@ match_wildcards:
 		if (!git_fnmatch(item, match, base->buf + base_offset,
 				 item->nowildcard_len)) {
 			strbuf_setlen(base, base_offset + baselen);
-			return entry_interesting;
+			goto interesting;
 		}
 
 		/*
@@ -1071,7 +1078,7 @@ match_wildcards:
 		    !ps_strncmp(item, match, base->buf + base_offset,
 				item->nowildcard_len)) {
 			strbuf_setlen(base, base_offset + baselen);
-			return entry_interesting;
+			goto interesting;
 		}
 
 		strbuf_setlen(base, base_offset + baselen);
@@ -1085,6 +1092,38 @@ match_wildcards:
 		 */
 		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 */
 }