On 9/15/23 16:32, Marek Polacek wrote:
On Fri, Sep 15, 2023 at 02:08:46PM -0400, Jason Merrill wrote:
On 9/13/23 20:02, Marek Polacek wrote:
On Wed, Sep 13, 2023 at 05:57:47PM -0400, Jason Merrill wrote:
On 9/13/23 16:56, Marek Polacek wrote:
On Tue, Sep 12, 2023 at 05:26:25PM -0400, Jason Merrill wrote:
On 9/8/23 14:24, Marek Polacek wrote:
+ switch (TREE_CODE (stmt))
+ {
+ /* Unfortunately we must handle code like
+ false ? bar () : 42
+ where we have to check bar too. */
+ case COND_EXPR:
+ if (cp_fold_immediate_r (&TREE_OPERAND (stmt, 1), walk_subtrees, data))
+ return error_mark_node;
+ if (TREE_OPERAND (stmt, 2)
+ && cp_fold_immediate_r (&TREE_OPERAND (stmt, 2), walk_subtrees, data))
+ return error_mark_node;
Is this necessary? Doesn't walk_tree already walk into the arms of
COND_EXPR?
Unfortunately yes. The cp_fold call in cp_fold_r could fold the ?: into
a constant before we see it here. I've added a comment saying just that.
Ah. But in that case I guess we need to walk into the arms, not just check
the top-level expression in them.
Arg, of course. I was fooled into thinking that it would recurse, but
you're right. Fixed by using cp_walk_tree as I intended. Tested in
consteval34.C.
But maybe cp_fold_r should do that before the cp_fold, instead of this
function?
I...am not sure how that would be better than what I did.
Callers of cp_fold_immediate don't need this because cp_fold_r isn't
involved, so it isn't folding anything.
This is true.
cp_fold_r can walk the arms with cp_fold_r and then clear *walk_subtrees to
avoid walking the arms again normally.
I didn't think we wanted to do everything cp_fold_r does even in dead
branches, but ok.
Ah, that's a good point. With the recursive walk in
cp_fold_immediate_r, I suppose we could suppress it when called from
cp_fold_immediate with a new fold_flag? That would still allow for
cp_walk_tree_without_duplicates.
Incidentally, I notice you check for null op2 of COND_EXPR, should
probably also check op1.
Jason
