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.
The macro needs a lot from its caller: it needs 2 local vars, 1 of
which is a ref to a contained struct with named members. To support
these requirements, add:
1. __ASSERT_IS_LVALUE(_X):
ie: ((void)sizeof((void)0, &(x)))
2. __ASSERT_HAS_VEC_MEMBERS(_X, _Y):
compile-time check that the _Y "vector" exists
ie: _X->_Y and _X->num##_Y are lvalues.
The for_subvec() macro then invokes these before the for-loop itself;
they disappear at runtime. They do cause a "complex macro" CHECK from
checkpatch --strict.
Signed-off-by: Jim Cromie <[email protected]>
---
-v5+
add __ASSERT_*() macros
add then drop __chkp_no_side_effects() macro
due to changes v5+ drop Reviewed-by: Louis Chauvet <[email protected]>
this patch evokes these complaints,
the "reuses" are all lvalues, so not issues.
(vec) is incompatible with ## paste-up
do-while also wont work here.
CHECK: Macro argument '_vec' may be better as '(_vec)' to avoid precedence
issues
WARNING: Non-declarative macros with multiple statements should be enclosed in
a do - while loop
CHECK: Macro argument reuse '_i' - possible side-effects?
CHECK: Macro argument reuse '_sp' - possible side-effects?
CHECK: Macro argument reuse '_box' - possible side-effects?
CHECK: Macro argument reuse '_vec' - possible side-effects?
---
lib/dynamic_debug.c | 27 ++++++++++++++++++++++++---
1 file changed, 24 insertions(+), 3 deletions(-)
diff --git a/lib/dynamic_debug.c b/lib/dynamic_debug.c
index e882e951d585..94d05d09a128 100644
--- a/lib/dynamic_debug.c
+++ b/lib/dynamic_debug.c
@@ -128,6 +128,28 @@ do {
\
#define v3pr_info(fmt, ...) vnpr_info(3, fmt, ##__VA_ARGS__)
#define v4pr_info(fmt, ...) vnpr_info(4, fmt, ##__VA_ARGS__)
+/*
+ * 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 __ASSERT_IS_LVALUE(x) ((void)sizeof((void)0, &(x)))
+#define __ASSERT_HAS_VEC_MEMBER(_box, _vec) ({ \
+ (void)sizeof((_box)->_vec); \
+ (void)sizeof((_box)->num_##_vec); \
+})
+#define for_subvec(_i, _sp, _box, _vec) \
+ __ASSERT_IS_LVALUE(_i); \
+ __ASSERT_IS_LVALUE(_sp); \
+ __ASSERT_HAS_VEC_MEMBER(_box, _vec); \
+ for ((_i) = 0, (_sp) = (_box)->_vec; \
+ (_i) < (_box)->num_##_vec; \
+ (_i)++, (_sp)++)
+
static void vpr_info_dq(const struct ddebug_query *query, const char *msg)
{
/* trim any trailing newlines */
@@ -155,7 +177,7 @@ 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;
@@ -1231,8 +1253,7 @@ 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",
--
2.51.1
