Hi Jan,
On 8/22/22 12:59, Jan Beulich wrote:
On 19.08.2022 21:43, Xenia Ragiadakou wrote:
In macros dt_for_each_property_node(), dt_for_each_device_node() and
dt_for_each_child_node(), add parentheses around the macro parameters that
have the arrow operator applied, to prevent against unintended expansions.
Why is this relevant only when -> is used? For comparisons and the rhs of
assignments it's as relevant, ad even for the lhs of assignments I doubt
it can be generally omitted.
Yes, I agree with you but some older patches that I sent that were
adding parentheses around the lhs of the assignments were not accepted
and I thought that the rhs of the assignments as well these comparisons
fall to the same category.
Personally, I would expect to see parentheses, also, around the macro
parameters that are used as the lhs or the rhs of assignments, the
operands of comparison or the arguments of a function.
Not only because they can prevent against unintentional bugs but because
the parentheses help me to identify more easily the macro parameters
when reading a macro definition. I totally understand that for other
people parentheses may reduce readability.
--- a/xen/include/xen/device_tree.h
+++ b/xen/include/xen/device_tree.h
@@ -222,13 +222,13 @@ dt_find_interrupt_controller(const struct dt_device_match
*matches);
#define DT_ROOT_NODE_SIZE_CELLS_DEFAULT 1
#define dt_for_each_property_node(dn, pp) \
- for ( pp = dn->properties; pp != NULL; pp = pp->next )
+ for ( pp = (dn)->properties; pp != NULL; pp = (pp)->next )
#define dt_for_each_device_node(dt, dn) \
- for ( dn = dt; dn != NULL; dn = dn->allnext )
+ for ( dn = dt; dn != NULL; dn = (dn)->allnext )
#define dt_for_each_child_node(dt, dn) \
- for ( dn = dt->child; dn != NULL; dn = dn->sibling )
+ for ( dn = (dt)->child; dn != NULL; dn = (dn)->sibling )
/* Helper to read a big number; size is in cells (not bytes) */
static inline u64 dt_read_number(const __be32 *cell, int size)
--
Xenia
