Hi!
The ggc_set_mark call in gt_value_expr_mark_2 is actually wrong, that
just marks the VAR_DECL itself, but doesn't mark the subtrees of it (type
etc.). So, I think we need to test gcc_marked_p for whether it is marked
or not, if not marked walk the DECL_VALUE_EXPR and then gt_ggc_mx mark
the VAR_DECL that was determined not marked and needs to be marked now.
One option would be to call gt_ggc_mx (t) right after the DECL_VALUE_EXPR
walking, but I'm a little bit worried that the subtree marking could mark
other VAR_DECLs (e.g. seen from DECL_SIZE or TREE_TYPE and the like) and
if they would be DECL_HAS_VALUE_EXPR_P we might not walk their
DECL_VALUE_EXPR anymore later.
So, the patch defers the gt_ggc_mx calls until we've walked all the
DECL_VALUE_EXPRs directly or indirectly connected to already marked
VAR_DECLs.
Ok for trunk if this passes bootstrap/regtest?
2025-02-13 Jakub Jelinek <ja...@redhat.com>
PR debug/118790
* tree.cc (struct gt_value_expr_mark_data): New type.
(gt_value_expr_mark_2): Don't call ggc_set_mark, instead check
ggc_marked_p. Treat data as gt_value_expr_mark_data * with pset
in it rather than address of the pset itself and push to be marked
VAR_DECLs into to_mark vec.
(gt_value_expr_mark_1): Change argument from hash_set<tree> *
to gt_value_expr_mark_data * and find pset in it.
(gt_value_expr_mark): Pass to traverse_noresize address of
gt_value_expr_mark_data object rather than hash_table<tree> and
for all entries in the to_mark vector after the traversal call
gt_ggc_mx.
--- gcc/tree.cc.jj 2025-02-13 14:14:44.330394074 +0100
+++ gcc/tree.cc 2025-02-13 16:24:39.609106712 +0100
@@ -211,6 +211,11 @@ struct cl_option_hasher : ggc_cache_ptr_
static GTY ((cache)) hash_table<cl_option_hasher> *cl_option_hash_table;
+struct gt_value_expr_mark_data {
+ hash_set<tree> pset;
+ auto_vec<tree, 16> to_mark;
+};
+
/* Callback called through walk_tree_1 to discover DECL_HAS_VALUE_EXPR_P
VAR_DECLs which weren't marked yet, in that case marks them and
walks their DECL_VALUE_EXPR expressions. */
@@ -219,11 +224,12 @@ static tree
gt_value_expr_mark_2 (tree *tp, int *, void *data)
{
tree t = *tp;
- if (VAR_P (t) && DECL_HAS_VALUE_EXPR_P (t) && !ggc_set_mark (t))
+ if (VAR_P (t) && DECL_HAS_VALUE_EXPR_P (t) && !ggc_marked_p (t))
{
tree dve = DECL_VALUE_EXPR (t);
- walk_tree_1 (&dve, gt_value_expr_mark_2, data,
- (hash_set<tree> *) data, NULL);
+ gt_value_expr_mark_data *d = (gt_value_expr_mark_data *) data;
+ walk_tree_1 (&dve, gt_value_expr_mark_2, data, &d->pset, NULL);
+ d->to_mark.safe_push (t);
}
return NULL_TREE;
}
@@ -232,10 +238,10 @@ gt_value_expr_mark_2 (tree *tp, int *, v
value_expr_for_decl hash table. */
int
-gt_value_expr_mark_1 (tree_decl_map **e, hash_set<tree> *pset)
+gt_value_expr_mark_1 (tree_decl_map **e, gt_value_expr_mark_data *data)
{
if (ggc_marked_p ((*e)->base.from))
- walk_tree_1 (&(*e)->to, gt_value_expr_mark_2, pset, pset, NULL);
+ walk_tree_1 (&(*e)->to, gt_value_expr_mark_2, data, &data->pset, NULL);
return 1;
}
@@ -255,8 +261,11 @@ gt_value_expr_mark (hash_table<tree_decl
if (!h)
return;
- hash_set<tree> pset;
- h->traverse_noresize<hash_set<tree> *, gt_value_expr_mark_1> (&pset);
+ gt_value_expr_mark_data data;
+ h->traverse_noresize<gt_value_expr_mark_data *,
+ gt_value_expr_mark_1> (&data);
+ for (auto v : data.to_mark)
+ gt_ggc_mx (v);
}
/* General tree->tree mapping structure for use in hash tables. */
Jakub
