Le 16/07/2025 à 00:05, Steve Kargl a écrit :
On Sun, Jul 13, 2025 at 10:59:32AM +0200, Mikael Morin wrote:
Regression tested on x86_64-pc-linux-gnu.
OK for master?
Yes, with one observation below.
diff --git a/gcc/fortran/trans-array.cc b/gcc/fortran/trans-array.cc
index 1561936daf1..af62e17442b 100644
--- a/gcc/fortran/trans-array.cc
+++ b/gcc/fortran/trans-array.cc
@@ -3437,6 +3437,148 @@ save_descriptor_data (tree descr, tree data)
}
+/* Type of the DATA argument passed to walk_tree by substitute_subexpr_in_expr
+ and used by maybe_substitute_expr. */
+
+typedef struct
+{
+ tree target, repl;
+}
+substitute_t;
+
+
+/* Check if the expression in *TP is equal to the substitution target provided
+ in DATA->TARGET and replace it with DATA->REPL in that case. This is a
+ callback function for use with walk_tree. */
+
+static tree
+maybe_substitute_expr (tree *tp, int *walk_subtree, void *data)
+{
+ substitute_t *subst = (substitute_t *) data;
+ if (*tp == subst->target)
+ {
+ *tp = subst->repl;
+ *walk_subtree = 0;
+ }
+
+ return NULL_TREE;
+}
Can you explain why the above function always
returns NULL_TREE? It would seem to me that
that function could be declared "static void"
or "static void *". Is this simply to avoid
a ...
+
+/* Substitute in EXPR any occurence of TARGET with REPLACEMENT. */
+
+static void
+substitute_subexpr_in_expr (tree target, tree replacement, tree expr)
+{
+ substitute_t subst;
+ subst.target = target;
+ subst.repl = replacement;
+
+ walk_tree (&expr, maybe_substitute_expr, &subst, nullptr);
cast here?
Well, yes and no.
Yes: the function signature was determined by the call to walk_tree here.
No: walk_tree expects a value to be returned by the function, and it
checks that value. So a cast of a function returning "void" wouldn't
work (but it would work for "void *").
The walk_tree function has many different usages. Its callback return
value can be useless in some cases like here, but it's useful in some
other cases, so it has to be present in all cases.
Thanks for the review.
