[PATCH v6 18/24] dyndbg: macrofy a 2-index for-loop pattern
From: Jim Cromie <jim.cromie@gmail.com>
Date: 2026-07-08 02:19:04
Also in:
dri-devel, linux-arch, linux-doc, lkml
Subsystem:
dynamic debug, library code, the rest · Maintainers:
Jason Baron, Jim Cromie, Andrew Morton, Linus Torvalds
dynamic-debug currently has 2 __sections (__dyndbg, __dyndb_classes),
struct _ddebug_info keeps track of them both, with 2 members each:
_vec and _vec#_len.
We need to loop over these sections, with index and record pointer,
making ref to both _vec and _vec_len. This is already fiddly and
error-prone, and will get worse as we add a 3rd section.
Lets instead embed/abstract the fiddly-ness in the `for_subvec()`
macro, and avoid repeating it going forward.
This is a for-loop macro expander, so it syntactically expects to
precede either a single statement or a { block } of them, and the
usual typeof or do-while-0 tricks are unavailable to fix the
multiple-expansion warning.
Signed-off-by: Jim Cromie <jim.cromie@gmail.com>
Reviewed-by: Louis Chauvet <louis.chauvet@bootlin.com>
---
v2: move RvB after SoB
---
lib/dynamic_debug.c | 19 ++++++++++++++++---
1 file changed, 16 insertions(+), 3 deletions(-)
diff --git a/lib/dynamic_debug.c b/lib/dynamic_debug.c
index 6b699ed23d26..d99c69b9ad12 100644
--- a/lib/dynamic_debug.c
+++ b/lib/dynamic_debug.c@@ -149,6 +149,20 @@ static void v3pr_info_dq(const struct ddebug_query *query, const char *msg) query->first_lineno, query->last_lineno, query->class_string); } +/* + * simplify a repeated for-loop pattern walking N steps in a T _vec + * member inside a struct _box. It expects int i and T *_sp to be + * declared in the caller. + * @_i: caller provided counter. + * @_sp: cursor into _vec, to examine each item. + * @_box: ptr to a struct containing @_vec member + * @_vec: name of a member in @_box + */ +#define for_subvec(_i, _sp, _box, _vec) \ + for ((_i) = 0, (_sp) = (_box)->_vec; \ + (_i) < (_box)->num_##_vec; \ + (_i)++, (_sp)++) /* { block } */ + static struct ddebug_class_map *ddebug_find_valid_class(struct ddebug_table const *dt, const char *class_string, int *class_id)
@@ -156,7 +170,7 @@ static struct ddebug_class_map *ddebug_find_valid_class(struct ddebug_table cons struct ddebug_class_map *map; int i, idx; - for (map = dt->classes, i = 0; i < dt->num_classes; i++, map++) { + for_subvec(i, map, dt, classes) { idx = match_string(map->class_names, map->length, class_string); if (idx >= 0) { *class_id = idx + map->base;
@@ -1167,8 +1181,7 @@ static void ddebug_attach_module_classes(struct ddebug_table *dt, struct _ddebug * the builtin/modular classmap vector/section. Save the start * and length of the subrange at its edges. */ - for (cm = di->classes, i = 0; i < di->num_classes; i++, cm++) { - + for_subvec(i, cm, di, classes) { if (!strcmp(cm->mod_name, dt->mod_name)) { if (!nc) { v2pr_info("start subrange, class[%d]: module:%s base:%d len:%d ty:%d\n",
--
2.55.0