[PATCHv2 00/36] Revamping the attr subsystem!

@@ -415,8 +415,7 @@ int find_commit_subject(const char *commit_buffer, const char **subject)
 		p++;
 	if (*p) {
 		p = skip_blank_lines(p + 2);
-		for (eol = p; *eol && *eol != '\n'; eol++)
-			; /* do nothing */
+		eol = strchrnul(p, '\n');
 	} else
 		eol = p;
 

@@ -402,8 +402,8 @@ static struct attr_stack *read_attr_from_index(const char *path, int macro_ok)
 	for (sp = buf; *sp; ) {
 		char *ep;
 		int more;
-		for (ep = sp; *ep && *ep != '\n'; ep++)
-			;
+
+		ep = strchrnul(sp, '\n');
 		more = (*ep == '\n');
 		*ep = '\0';
 		handle_attr_line(res, sp, path, ++lineno, macro_ok);

@@ -183,6 +183,12 @@ static const char *parse_attr(const char *src, int lineno, const char *cp,
 			return NULL;
 		}
 	} else {
+		/*
+		 * As this function is always called twice, once with
+		 * e == NULL in the first pass and then e != NULL in
+		 * the second pass, no need for invalid_attr_name()
+		 * check here.
+		 */
 		if (*cp == '-' || *cp == '!') {
 			e->setto = (*cp == '-') ? ATTR__FALSE : ATTR__UNSET;
 			cp++;

@@ -469,7 +469,7 @@ static void debug_set(const char *what, const char *match, struct git_attr *attr
 #define debug_push(a) do { ; } while (0)
 #define debug_pop(a) do { ; } while (0)
 #define debug_set(a,b,c,d) do { ; } while (0)
-#endif
+#endif /* DEBUG_ATTR */
 
 static void drop_attr_stack(void)
 {

@@ -300,7 +300,7 @@ static struct match_attr *parse_attr_line(const char *line, const char *src,
  * directory (again, reading the file from top to bottom) down to the
  * current directory, and then scan the list backwards to find the first match.
  * This is exactly the same as what is_excluded() does in dir.c to deal with
- * .gitignore
+ * .gitignore file and info/excludes file as a fallback.
  */
 
 static struct attr_stack {

@@ -131,9 +131,8 @@ struct pattern {
  * If is_macro is true, then u.attr is a pointer to the git_attr being
  * defined.
  *
- * If is_macro is false, then u.pattern points at the filename pattern
- * to which the rule applies.  (The memory pointed to is part of the
- * memory block allocated for the match_attr instance.)
+ * If is_macro is false, then u.pat is the filename pattern to which the
+ * rule applies.
  *
  * In either case, num_attr is the number of attributes affected by
  * this rule, and state is an array listing them.  The attributes are

@@ -223,7 +223,7 @@ static struct match_attr *parse_attr_line(const char *line, const char *src,
 		if (!macro_ok) {
 			fprintf(stderr, "%s not allowed: %s:%d\n",
 				name, src, lineno);
-			return NULL;
+			goto fail_return;
 		}
 		is_macro = 1;
 		name += strlen(ATTRIBUTE_MACRO_PREFIX);

@@ -233,7 +233,7 @@ static struct match_attr *parse_attr_line(const char *line, const char *src,
 			fprintf(stderr,
 				"%.*s is not a valid attribute name: %s:%d\n",
 				namelen, name, src, lineno);
-			return NULL;
+			goto fail_return;
 		}
 	}
 	else

@@ -246,7 +246,7 @@ static struct match_attr *parse_attr_line(const char *line, const char *src,
 	for (cp = states, num_attr = 0; *cp; num_attr++) {
 		cp = parse_attr(src, lineno, cp, NULL);
 		if (!cp)
-			return NULL;
+			goto fail_return;
 	}
 
 	res = xcalloc(1,

@@ -267,7 +267,7 @@ static struct match_attr *parse_attr_line(const char *line, const char *src,
 		if (res->u.pat.flags & EXC_FLAG_NEGATIVE) {
 			warning(_("Negative patterns are ignored in git attributes\n"
 				  "Use '\\!' for literal leading exclamation."));
-			return NULL;
+			goto fail_return;
 		}
 	}
 	res->is_macro = is_macro;

@@ -283,6 +283,10 @@ static struct match_attr *parse_attr_line(const char *line, const char *src,
 	}
 
 	return res;
+
+fail_return:
+	free(res);
+	return NULL;
 }
 
 /*

@@ -701,24 +701,21 @@ static int fill(const char *path, int pathlen, int basename_offset,
 static int macroexpand_one(int nr, int rem)
 {
 	struct attr_stack *stk;
-	struct match_attr *a = NULL;
 	int i;
 
 	if (check_all_attr[nr].value != ATTR__TRUE ||
 	    !check_all_attr[nr].attr->maybe_macro)
 		return rem;
 
-	for (stk = attr_stack; !a && stk; stk = stk->prev)
-		for (i = stk->num_matches - 1; !a && 0 <= i; i--) {
+	for (stk = attr_stack; stk; stk = stk->prev) {
+		for (i = stk->num_matches - 1; 0 <= i; i--) {
 			struct match_attr *ma = stk->attrs[i];
 			if (!ma->is_macro)
 				continue;
 			if (ma->u.attr->attr_nr == nr)
-				a = ma;
+				return fill_one("expand", ma, rem);
 		}
-
-	if (a)
-		rem = fill_one("expand", a, rem);
+	}
 
 	return rem;
 }

@@ -87,7 +87,7 @@ void *sha1_file_to_archive(const struct archiver_args *args,
 	return buffer;
 }
 
-static void setup_archive_check(struct git_attr_check *check)
+static void setup_archive_check(struct git_attr_check_elem *check)
 {
 	static struct git_attr *attr_export_ignore;
 	static struct git_attr *attr_export_subst;

@@ -123,7 +123,7 @@ static int write_archive_entry(const unsigned char *sha1, const char *base,
 	struct archiver_context *c = context;
 	struct archiver_args *args = c->args;
 	write_archive_entry_fn_t write_entry = c->write_entry;
-	struct git_attr_check check[2];
+	struct git_attr_check_elem check[2];
 	const char *path_without_prefix;
 	int err;
 

@@ -138,7 +138,7 @@ static int write_archive_entry(const unsigned char *sha1, const char *base,
 	path_without_prefix = path.buf + args->baselen;
 
 	setup_archive_check(check);
-	if (!git_check_attr(path_without_prefix, ARRAY_SIZE(check), check)) {
+	if (!git_check_attrs(path_without_prefix, ARRAY_SIZE(check), check)) {
 		if (ATTR_TRUE(check[0].value))
 			return 0;
 		args->convert = ATTR_TRUE(check[1].value);

@@ -40,7 +40,7 @@ struct git_attr {
 static int attr_nr;
 static int cannot_trust_maybe_real;
 
-static struct git_attr_check *check_all_attr;
+static struct git_attr_check_elem *check_all_attr;
 static struct git_attr *(git_attr_hash[HASHSIZE]);
 
 const char *git_attr_name(const struct git_attr *attr)

@@ -665,7 +665,7 @@ static int macroexpand_one(int attr_nr, int rem);
 
 static int fill_one(const char *what, struct match_attr *a, int rem)
 {
-	struct git_attr_check *check = check_all_attr;
+	struct git_attr_check_elem *check = check_all_attr;
 	int i;
 
 	for (i = a->num_attr - 1; 0 < rem && 0 <= i; i--) {

@@ -730,7 +730,7 @@ static int macroexpand_one(int nr, int rem)
  * collected. Otherwise all attributes are collected.
  */
 static void collect_some_attrs(const char *path, int num,
-			       struct git_attr_check *check)
+			       struct git_attr_check_elem *check)
 
 {
 	struct attr_stack *stk;

@@ -758,7 +758,7 @@ static void collect_some_attrs(const char *path, int num,
 		rem = 0;
 		for (i = 0; i < num; i++) {
 			if (!check[i].attr->maybe_real) {
-				struct git_attr_check *c;
+				struct git_attr_check_elem *c;
 				c = check_all_attr + check[i].attr->attr_nr;
 				c->value = ATTR__UNSET;
 				rem++;

@@ -773,7 +773,7 @@ static void collect_some_attrs(const char *path, int num,
 		rem = fill(path, pathlen, basename_offset, stk, rem);
 }
 
-int git_check_attr(const char *path, int num, struct git_attr_check *check)
+int git_check_attrs(const char *path, int num, struct git_attr_check_elem *check)
 {
 	int i;
 

@@ -789,7 +789,7 @@ int git_check_attr(const char *path, int num, struct git_attr_check *check)
 	return 0;
 }
 
-int git_all_attrs(const char *path, int *num, struct git_attr_check **check)
+int git_all_attrs(const char *path, int *num, struct git_attr_check_elem **check)
 {
 	int i, count, j;
 

@@ -20,11 +20,11 @@ extern const char git_attr__false[];
 #define ATTR_UNSET(v) ((v) == NULL)
 
 /*
- * Send one or more git_attr_check to git_check_attr(), and
+ * Send one or more git_attr_check to git_check_attrs(), and
  * each 'value' member tells what its value is.
  * Unset one is returned as NULL.
  */
-struct git_attr_check {
+struct git_attr_check_elem {
 	const struct git_attr *attr;
 	const char *value;
 };

@@ -36,7 +36,7 @@ struct git_attr_check {
  */
 extern const char *git_attr_name(const struct git_attr *);
 
-int git_check_attr(const char *path, int, struct git_attr_check *);
+int git_check_attrs(const char *path, int, struct git_attr_check_elem *);
 
 /*
  * Retrieve all attributes that apply to the specified path.  *num

@@ -45,7 +45,7 @@ int git_check_attr(const char *path, int, struct git_attr_check *);
  * objects describing the attributes and their values.  *check must be
  * free()ed by the caller.
  */
-int git_all_attrs(const char *path, int *num, struct git_attr_check **check);
+int git_all_attrs(const char *path, int *num, struct git_attr_check_elem **check);
 
 enum git_attr_direction {
 	GIT_ATTR_CHECKIN,

@@ -24,8 +24,8 @@ static const struct option check_attr_options[] = {
 	OPT_END()
 };
 
-static void output_attr(int cnt, struct git_attr_check *check,
-	const char *file)
+static void output_attr(int cnt, struct git_attr_check_elem *check,
+			const char *file)
 {
 	int j;
 	for (j = 0; j < cnt; j++) {

@@ -51,14 +51,15 @@ static void output_attr(int cnt, struct git_attr_check *check,
 	}
 }
 
-static void check_attr(const char *prefix, int cnt,
-	struct git_attr_check *check, const char *file)
+static void check_attr(const char *prefix,
+		       int cnt, struct git_attr_check_elem *check,
+		       const char *file)
 {
 	char *full_path =
 		prefix_path(prefix, prefix ? strlen(prefix) : 0, file);
 	if (check != NULL) {
-		if (git_check_attr(full_path, cnt, check))
-			die("git_check_attr died");
+		if (git_check_attrs(full_path, cnt, check))
+			die("git_check_attrs died");
 		output_attr(cnt, check, file);
 	} else {
 		if (git_all_attrs(full_path, &cnt, &check))

@@ -69,8 +70,8 @@ static void check_attr(const char *prefix, int cnt,
 	free(full_path);
 }
 
-static void check_attr_stdin_paths(const char *prefix, int cnt,
-	struct git_attr_check *check)
+static void check_attr_stdin_paths(const char *prefix,
+				   int cnt, struct git_attr_check_elem *check)
 {
 	struct strbuf buf = STRBUF_INIT;
 	struct strbuf unquoted = STRBUF_INIT;

@@ -99,7 +100,7 @@ static NORETURN void error_with_usage(const char *msg)
 
 int cmd_check_attr(int argc, const char **argv, const char *prefix)
 {
-	struct git_attr_check *check;
+	struct git_attr_check_elem *check;
 	int cnt, i, doubledash, filei;
 
 	if (!is_bare_repository())

@@ -896,7 +896,7 @@ static void write_pack_file(void)
 			written, nr_result);
 }
 
-static void setup_delta_attr_check(struct git_attr_check *check)
+static void setup_delta_attr_check(struct git_attr_check_elem *check)
 {
 	static struct git_attr *attr_delta;
 

@@ -908,10 +908,10 @@ static void setup_delta_attr_check(struct git_attr_check *check)
 
 static int no_try_delta(const char *path)
 {
-	struct git_attr_check check[1];
+	struct git_attr_check_elem check[1];
 
 	setup_delta_attr_check(check);
-	if (git_check_attr(path, ARRAY_SIZE(check), check))
+	if (git_check_attrs(path, ARRAY_SIZE(check), check))
 		return 0;
 	if (ATTR_FALSE(check->value))
 		return 1;

@@ -718,7 +718,7 @@ static int ident_to_worktree(const char *path, const char *src, size_t len,
 	return 1;
 }
 
-static enum crlf_action git_path_check_crlf(struct git_attr_check *check)
+static enum crlf_action git_path_check_crlf(struct git_attr_check_elem *check)
 {
 	const char *value = check->value;
 

@@ -735,7 +735,7 @@ static enum crlf_action git_path_check_crlf(struct git_attr_check *check)
 	return CRLF_UNDEFINED;
 }
 
-static enum eol git_path_check_eol(struct git_attr_check *check)
+static enum eol git_path_check_eol(struct git_attr_check_elem *check)
 {
 	const char *value = check->value;
 

@@ -748,7 +748,7 @@ static enum eol git_path_check_eol(struct git_attr_check *check)
 	return EOL_UNSET;
 }
 
-static struct convert_driver *git_path_check_convert(struct git_attr_check *check)
+static struct convert_driver *git_path_check_convert(struct git_attr_check_elem *check)
 {
 	const char *value = check->value;
 	struct convert_driver *drv;

@@ -761,7 +761,7 @@ static struct convert_driver *git_path_check_convert(struct git_attr_check *chec
 	return NULL;
 }
 
-static int git_path_check_ident(struct git_attr_check *check)
+static int git_path_check_ident(struct git_attr_check_elem *check)
 {
 	const char *value = check->value;
 

@@ -783,7 +783,7 @@ static const char *conv_attr_name[] = {
 static void convert_attrs(struct conv_attrs *ca, const char *path)
 {
 	int i;
-	static struct git_attr_check ccheck[NUM_CONV_ATTRS];
+	static struct git_attr_check_elem ccheck[NUM_CONV_ATTRS];
 
 	if (!ccheck[0].attr) {
 		for (i = 0; i < NUM_CONV_ATTRS; i++)

@@ -792,7 +792,7 @@ static void convert_attrs(struct conv_attrs *ca, const char *path)
 		git_config(read_convert_config, NULL);
 	}
 
-	if (!git_check_attr(path, NUM_CONV_ATTRS, ccheck)) {
+	if (!git_check_attrs(path, NUM_CONV_ATTRS, ccheck)) {
 		ca->crlf_action = git_path_check_crlf(ccheck + 4);
 		if (ca->crlf_action == CRLF_UNDEFINED)
 			ca->crlf_action = git_path_check_crlf(ccheck + 0);

@@ -336,13 +336,13 @@ static const struct ll_merge_driver *find_ll_merge_driver(const char *merge_attr
 	return &ll_merge_drv[LL_TEXT_MERGE];
 }
 
-static int git_path_check_merge(const char *path, struct git_attr_check check[2])
+static int git_path_check_merge(const char *path, struct git_attr_check_elem check[2])
 {
 	if (!check[0].attr) {
 		check[0].attr = git_attr("merge");
 		check[1].attr = git_attr("conflict-marker-size");
 	}
-	return git_check_attr(path, 2, check);
+	return git_check_attrs(path, 2, check);
 }
 
 static void normalize_file(mmfile_t *mm, const char *path)

@@ -362,7 +362,7 @@ int ll_merge(mmbuffer_t *result_buf,
 	     mmfile_t *theirs, const char *their_label,
 	     const struct ll_merge_options *opts)
 {
-	static struct git_attr_check check[2];
+	static struct git_attr_check_elem check[2];
 	static const struct ll_merge_options default_opts;
 	const char *ll_driver_name = NULL;
 	int marker_size = DEFAULT_CONFLICT_MARKER_SIZE;

@@ -398,12 +398,12 @@ int ll_merge(mmbuffer_t *result_buf,
 
 int ll_merge_marker_size(const char *path)
 {
-	static struct git_attr_check check;
+	static struct git_attr_check_elem check;
 	int marker_size = DEFAULT_CONFLICT_MARKER_SIZE;
 
 	if (!check.attr)
 		check.attr = git_attr("conflict-marker-size");
-	if (!git_check_attr(path, 1, &check) && check.value) {
+	if (!git_check_attrs(path, 1, &check) && check.value) {
 		marker_size = atoi(check.value);
 		if (marker_size <= 0)
 			marker_size = DEFAULT_CONFLICT_MARKER_SIZE;

@@ -263,7 +263,7 @@ struct userdiff_driver *userdiff_find_by_name(const char *name) {
 struct userdiff_driver *userdiff_find_by_path(const char *path)
 {
 	static struct git_attr *attr;
-	struct git_attr_check check;
+	struct git_attr_check_elem check;
 
 	if (!attr)
 		attr = git_attr("diff");

@@ -271,7 +271,7 @@ struct userdiff_driver *userdiff_find_by_path(const char *path)
 
 	if (!path)
 		return NULL;
-	if (git_check_attr(path, 1, &check))
+	if (git_check_attrs(path, 1, &check))
 		return NULL;
 
 	if (ATTR_TRUE(check.value))

@@ -71,7 +71,7 @@ unsigned parse_whitespace_rule(const char *string)
 	return rule;
 }
 
-static void setup_whitespace_attr_check(struct git_attr_check *check)
+static void setup_whitespace_attr_check(struct git_attr_check_elem *check)
 {
 	static struct git_attr *attr_whitespace;
 

@@ -82,10 +82,10 @@ static void setup_whitespace_attr_check(struct git_attr_check *check)
 
 unsigned whitespace_rule(const char *pathname)
 {
-	struct git_attr_check attr_whitespace_rule;
+	struct git_attr_check_elem attr_whitespace_rule;
 
 	setup_whitespace_attr_check(&attr_whitespace_rule);
-	if (!git_check_attr(pathname, 1, &attr_whitespace_rule)) {
+	if (!git_check_attrs(pathname, 1, &attr_whitespace_rule)) {
 		const char *value;
 
 		value = attr_whitespace_rule.value;

@@ -43,7 +43,7 @@ static int cannot_trust_maybe_real;
 static struct git_attr_check *check_all_attr;
 static struct git_attr *(git_attr_hash[HASHSIZE]);
 
-char *git_attr_name(struct git_attr *attr)
+const char *git_attr_name(const struct git_attr *attr)
 {
 	return attr->name;
 }

@@ -25,7 +25,7 @@ extern const char git_attr__false[];
  * Unset one is returned as NULL.
  */
 struct git_attr_check {
-	struct git_attr *attr;
+	const struct git_attr *attr;
 	const char *value;
 };
 

@@ -34,7 +34,7 @@ struct git_attr_check {
  * return value is a pointer to a null-delimited string that is part
  * of the internal data structure; it should not be modified or freed.
  */
-char *git_attr_name(struct git_attr *);
+extern const char *git_attr_name(const struct git_attr *);
 
 int git_check_attr(const char *path, int, struct git_attr_check *);
 

@@ -724,6 +724,11 @@ static int macroexpand_one(int nr, int rem)
 	return rem;
 }
 
+static int attr_check_is_dynamic(const struct git_attr_check *check)
+{
+	return (void *)(check->check) != (void *)(check + 1);
+}
+
 /*
  * Collect attributes for path into the array pointed to by
  * check_all_attr. If num is non-zero, only attributes in check[] are

@@ -789,32 +794,21 @@ int git_check_attrs(const char *path, int num, struct git_attr_check_elem *check
 	return 0;
 }
 
-int git_all_attrs(const char *path, int *num, struct git_attr_check_elem **check)
+void git_all_attrs(const char *path, struct git_attr_check *check)
 {
-	int i, count, j;
+	int i;
 
+	git_attr_check_clear(check);
 	collect_some_attrs(path, 0, NULL);
 
-	/* Count the number of attributes that are set. */
-	count = 0;
-	for (i = 0; i < attr_nr; i++) {
-		const char *value = check_all_attr[i].value;
-		if (value != ATTR__UNSET && value != ATTR__UNKNOWN)
-			++count;
-	}
-	*num = count;
-	ALLOC_ARRAY(*check, count);
-	j = 0;
 	for (i = 0; i < attr_nr; i++) {
+		const char *name = check_all_attr[i].attr->name;
 		const char *value = check_all_attr[i].value;
-		if (value != ATTR__UNSET && value != ATTR__UNKNOWN) {
-			(*check)[j].attr = check_all_attr[i].attr;
-			(*check)[j].value = value;
-			++j;
-		}
+		if (value == ATTR__UNSET || value == ATTR__UNKNOWN)
+			continue;
+		git_attr_check_append(check, git_attr(name));
+		check->check[check->check_nr - 1].value = value;
 	}
-
-	return 0;
 }
 
 void git_attr_set_direction(enum git_attr_direction new, struct index_state *istate)

@@ -832,6 +826,7 @@ void git_attr_set_direction(enum git_attr_direction new, struct index_state *ist
 
 int git_check_attr(const char *path, struct git_attr_check *check)
 {
+	check->finalized = 1;
 	return git_check_attrs(path, check->check_nr, check->check);
 }
 

@@ -849,17 +844,57 @@ struct git_attr_check *git_attr_check_initl(const char *one, ...)
 	check = xcalloc(1,
 			sizeof(*check) + cnt * sizeof(*(check->check)));
 	check->check_nr = cnt;
+	check->finalized = 1;
 	check->check = (struct git_attr_check_elem *)(check + 1);
 
 	check->check[0].attr = git_attr(one);
 	va_start(params, one);
 	for (cnt = 1; cnt < check->check_nr; cnt++) {
+		struct git_attr *attr;
 		param = va_arg(params, const char *);
 		if (!param)
 			die("BUG: counted %d != ended at %d",
 			    check->check_nr, cnt);
-		check->check[cnt].attr = git_attr(param);
+		attr = git_attr(param);
+		if (!attr)
+			die("BUG: %s: not a valid attribute name", param);
+		check->check[cnt].attr = attr;
 	}
 	va_end(params);
 	return check;
 }
+
+struct git_attr_check *git_attr_check_alloc(void)
+{
+	return xcalloc(1, sizeof(struct git_attr_check));
+}
+
+struct git_attr_check_elem *git_attr_check_append(struct git_attr_check *check,
+						  const struct git_attr *attr)
+{
+	struct git_attr_check_elem *elem;
+	if (check->finalized)
+		die("BUG: append after git_attr_check structure is finalized");
+	if (!attr_check_is_dynamic(check))
+		die("BUG: appending to a statically initialized git_attr_check");
+	ALLOC_GROW(check->check, check->check_nr + 1, check->check_alloc);
+	elem = &check->check[check->check_nr++];
+	elem->attr = attr;
+	return elem;
+}
+
+void git_attr_check_clear(struct git_attr_check *check)
+{
+	if (!attr_check_is_dynamic(check))
+		die("BUG: clearing a statically initialized git_attr_check");
+	free(check->check);
+	check->check_nr = 0;
+	check->check_alloc = 0;
+	check->finalized = 0;
+}
+
+void git_attr_check_free(struct git_attr_check *check)
+{
+	git_attr_check_clear(check);
+	free(check);
+}

@@ -30,6 +30,7 @@ struct git_attr_check_elem {
 };
 
 struct git_attr_check {
+	int finalized;
 	int check_nr;
 	int check_alloc;
 	struct git_attr_check_elem *check;

@@ -38,6 +39,12 @@ struct git_attr_check {
 extern struct git_attr_check *git_attr_check_initl(const char *, ...);
 extern int git_check_attr(const char *path, struct git_attr_check *);
 
+extern struct git_attr_check *git_attr_check_alloc(void);
+extern struct git_attr_check_elem *git_attr_check_append(struct git_attr_check *, const struct git_attr *);
+
+extern void git_attr_check_clear(struct git_attr_check *);
+extern void git_attr_check_free(struct git_attr_check *);
+
 /*
  * Return the name of the attribute represented by the argument.  The
  * return value is a pointer to a null-delimited string that is part

@@ -48,13 +55,10 @@ extern const char *git_attr_name(const struct git_attr *);
 int git_check_attrs(const char *path, int, struct git_attr_check_elem *);
 
 /*
- * Retrieve all attributes that apply to the specified path.  *num
- * will be set to the number of attributes on the path; **check will
- * be set to point at a newly-allocated array of git_attr_check
- * objects describing the attributes and their values.  *check must be
- * free()ed by the caller.
+ * Retrieve all attributes that apply to the specified path.
+ * check holds the attributes and their values.
  */
-int git_all_attrs(const char *path, int *num, struct git_attr_check_elem **check);
+void git_all_attrs(const char *path, struct git_attr_check *check);
 
 enum git_attr_direction {
 	GIT_ATTR_CHECKIN,

@@ -24,12 +24,13 @@ static const struct option check_attr_options[] = {
 	OPT_END()
 };
 
-static void output_attr(int cnt, struct git_attr_check_elem *check,
-			const char *file)
+static void output_attr(struct git_attr_check *check, const char *file)
 {
 	int j;
+	int cnt = check->check_nr;
+
 	for (j = 0; j < cnt; j++) {
-		const char *value = check[j].value;
+		const char *value = check->check[j].value;
 
 		if (ATTR_TRUE(value))
 			value = "set";

@@ -42,36 +43,37 @@ static void output_attr(int cnt, struct git_attr_check_elem *check,
 			printf("%s%c" /* path */
 			       "%s%c" /* attrname */
 			       "%s%c" /* attrvalue */,
-			       file, 0, git_attr_name(check[j].attr), 0, value, 0);
+			       file, 0,
+			       git_attr_name(check->check[j].attr), 0, value, 0);
 		} else {
 			quote_c_style(file, NULL, stdout, 0);
-			printf(": %s: %s\n", git_attr_name(check[j].attr), value);
+			printf(": %s: %s\n",
+			       git_attr_name(check->check[j].attr), value);
 		}
-
 	}
 }
 
 static void check_attr(const char *prefix,
-		       int cnt, struct git_attr_check_elem *check,
+		       struct git_attr_check *check,
 		       const char *file)
 {
 	char *full_path =
 		prefix_path(prefix, prefix ? strlen(prefix) : 0, file);
 	if (check != NULL) {
-		if (git_check_attrs(full_path, cnt, check))
-			die("git_check_attrs died");
-		output_attr(cnt, check, file);
+		if (git_check_attr(full_path, check))
+			die("git_check_attr died");
+		output_attr(check, file);
 	} else {
-		if (git_all_attrs(full_path, &cnt, &check))
-			die("git_all_attrs died");
-		output_attr(cnt, check, file);
-		free(check);
+		check = git_attr_check_alloc();
+		git_all_attrs(full_path, check);
+		output_attr(check, file);
+		git_attr_check_free(check);
 	}
 	free(full_path);
 }
 
 static void check_attr_stdin_paths(const char *prefix,
-				   int cnt, struct git_attr_check_elem *check)
+				   struct git_attr_check *check)
 {
 	struct strbuf buf = STRBUF_INIT;
 	struct strbuf unquoted = STRBUF_INIT;

@@ -85,7 +87,7 @@ static void check_attr_stdin_paths(const char *prefix,
 				die("line is badly quoted");
 			strbuf_swap(&buf, &unquoted);
 		}
-		check_attr(prefix, cnt, check, buf.buf);
+		check_attr(prefix, check, buf.buf);
 		maybe_flush_or_die(stdout, "attribute to stdout");
 	}
 	strbuf_release(&buf);

@@ -100,7 +102,7 @@ static NORETURN void error_with_usage(const char *msg)
 
 int cmd_check_attr(int argc, const char **argv, const char *prefix)
 {
-	struct git_attr_check_elem *check;
+	struct git_attr_check *check;
 	int cnt, i, doubledash, filei;
 
 	if (!is_bare_repository())

@@ -163,24 +165,21 @@ int cmd_check_attr(int argc, const char **argv, const char *prefix)
 	if (all_attrs) {
 		check = NULL;
 	} else {
-		check = xcalloc(cnt, sizeof(*check));
+		check = git_attr_check_alloc();
 		for (i = 0; i < cnt; i++) {
-			const char *name;
-			struct git_attr *a;
-			name = argv[i];
-			a = git_attr(name);
+			struct git_attr *a = git_attr(argv[i]);
 			if (!a)
 				return error("%s: not a valid attribute name",
-					name);
-			check[i].attr = a;
+					     argv[i]);
+			git_attr_check_append(check, a);
 		}
 	}
 
 	if (stdin_paths)
-		check_attr_stdin_paths(prefix, cnt, check);
+		check_attr_stdin_paths(prefix, check);
 	else {
 		for (i = filei; i < argc; i++)
-			check_attr(prefix, cnt, check, argv[i]);
+			check_attr(prefix, check, argv[i]);
 		maybe_flush_or_die(stdout, "attribute to stdout");
 	}
 	return 0;

@@ -16,10 +16,15 @@ Data Structure
 	of no interest to the calling programs.  The name of the
 	attribute can be retrieved by calling `git_attr_name()`.
 
+`struct git_attr_check_elem`::
+
+	This structure represents one attribute and its value.
+
 `struct git_attr_check`::
 
-	This structure represents a set of attributes to check in a call
-	to `git_check_attr()` function, and receives the results.
+	This structure represents a collection of `git_attr_check_elem`.
+	It is passed to `git_check_attr()` function, specifying the
+	attributes to check, and receives their values.
 
 
 Attribute Values

@@ -48,49 +53,51 @@ value of the attribute for the path.
 Querying Specific Attributes
 ----------------------------
 
-* Prepare an array of `struct git_attr_check` to define the list of
-  attributes you would want to check.  To populate this array, you would
-  need to define necessary attributes by calling `git_attr()` function.
+* Prepare `struct git_attr_check` using git_attr_check_initl()
+  function, enumerating the names of attributes whose values you are
+  interested in, terminated with a NULL pointer.  Alternatively, an
+  empty `struct git_attr_check` can be prepared by calling
+  `git_attr_check_alloc()` function and then attributes you want to
+  ask about can be added to it with `git_attr_check_append()`
+  function.
 
 * Call `git_check_attr()` to check the attributes for the path.
 
-* Inspect `git_attr_check` structure to see how each of the attribute in
-  the array is defined for the path.
+* Inspect `git_attr_check` structure to see how each of the
+  attribute in the array is defined for the path.
 
 
 Example
 -------
 
-To see how attributes "crlf" and "indent" are set for different paths.
+To see how attributes "crlf" and "ident" are set for different paths.
 
-. Prepare an array of `struct git_attr_check` with two elements (because
-  we are checking two attributes).  Initialize their `attr` member with
-  pointers to `struct git_attr` obtained by calling `git_attr()`:
+. Prepare a `struct git_attr_check` with two elements (because
+  we are checking two attributes):
 
 ------------
-static struct git_attr_check check[2];
+static struct git_attr_check *check;
 static void setup_check(void)
 {
-	if (check[0].attr)
+	if (check)
 		return; /* already done */
-	check[0].attr = git_attr("crlf");
-	check[1].attr = git_attr("ident");
+	check = git_attr_check_initl("crlf", "ident", NULL);
 }
 ------------
 
-. Call `git_check_attr()` with the prepared array of `struct git_attr_check`:
+. Call `git_check_attr()` with the prepared `struct git_attr_check`:
 
 ------------
 	const char *path;
 
 	setup_check();
-	git_check_attr(path, ARRAY_SIZE(check), check);
+	git_check_attr(path, check);
 ------------
 
-. Act on `.value` member of the result, left in `check[]`:
+. Act on `.value` member of the result, left in `check->check[]`:
 
 ------------
-	const char *value = check[0].value;
+	const char *value = check->check[0].value;
 
 	if (ATTR_TRUE(value)) {
 		The attribute is Set, by listing only the name of the

@@ -109,20 +116,39 @@ static void setup_check(void)
 	}
 ------------
 
+To see how attributes in argv[] are set for different paths, only
+the first step in the above would be different.
+
+------------
+static struct git_attr_check *check;
+static void setup_check(const char **argv)
+{
+	check = git_attr_check_alloc();
+	while (*argv) {
+		struct git_attr *attr = git_attr(*argv);
+		git_attr_check_append(check, attr);
+		argv++;
+	}
+}
+------------
+
 
 Querying All Attributes
 -----------------------
 
 To get the values of all attributes associated with a file:
 
-* Call `git_all_attrs()`, which returns an array of `git_attr_check`
-  structures.
+* Prepare an empty `git_attr_check` structure by calling
+  `git_attr_check_alloc()`.
+
+* Call `git_all_attrs()`, which populates the `git_attr_check`
+  with the attributes attached to the path.
 
-* Iterate over the `git_attr_check` array to examine the attribute
-  names and values.  The name of the attribute described by a
-  `git_attr_check` object can be retrieved via
-  `git_attr_name(check[i].attr)`.  (Please note that no items will be
-  returned for unset attributes, so `ATTR_UNSET()` will return false
-  for all returned `git_array_check` objects.)
+* Iterate over the `git_attr_check.check[]` array to examine
+  the attribute names and values.  The name of the attribute
+  described by a  `git_attr_check.check[]` object can be retrieved via
+  `git_attr_name(check->check[i].attr)`.  (Please note that no items
+  will be returned for unset attributes, so `ATTR_UNSET()` will return
+  false for all returned `git_array_check` objects.)
 
-* Free the `git_array_check` array.
+* Free the `git_array_check` by calling `git_attr_check_free()`.

@@ -778,7 +778,8 @@ static void collect_some_attrs(const char *path, int num,
 		rem = fill(path, pathlen, basename_offset, stk, rem);
 }
 
-int git_check_attrs(const char *path, int num, struct git_attr_check_elem *check)
+static int git_check_attrs(const char *path, int num,
+			   struct git_attr_check_elem *check)
 {
 	int i;
 

@@ -52,8 +52,6 @@ extern void git_attr_check_free(struct git_attr_check *);
  */
 extern const char *git_attr_name(const struct git_attr *);
 
-int git_check_attrs(const char *path, int, struct git_attr_check_elem *);
-
 /*
  * Retrieve all attributes that apply to the specified path.
  * check holds the attributes and their values.