From 006f28aefeb3be575239beddc7febe56dff463a2 Mon Sep 17 00:00:00 2001 From: Iain Sandoe Date: Tue, 9 Jun 2020 19:17:14 +0100 Subject: [PATCH] coroutines: Ensure distinct DTOR trees [PR95137]. Part of the PR notes that there are UBSAN fails for the coroutines test suite. These are primarily related to the use of the same DTOR tree in the two edges from the await block. Fixed by building a new tree for each. gcc/cp/ChangeLog: PR c++/95137 * coroutines.cc (expand_one_await_expression): Build separate DTOR trees for the awaitable object on the destroy and resume paths. --- gcc/cp/coroutines.cc | 22 +++++++++++++--------- 1 file changed, 13 insertions(+), 9 deletions(-) diff --git a/gcc/cp/coroutines.cc b/gcc/cp/coroutines.cc index e86b3d4..3c8c70f 100644 --- a/gcc/cp/coroutines.cc +++ b/gcc/cp/coroutines.cc @@ -1488,19 +1488,13 @@ expand_one_await_expression (tree *stmt, tree *await_expr, void *d) tree resume_label = create_named_label_with_ctx (loc, buf, actor); tree empty_list = build_empty_stmt (loc); - tree dtor = NULL_TREE; tree await_type = TREE_TYPE (var); - if (needs_dtor) - dtor = build_special_member_call (var, complete_dtor_identifier, NULL, - await_type, LOOKUP_NORMAL, - tf_warning_or_error); - tree stmt_list = NULL; tree t_expr = STRIP_NOPS (expr); tree r; tree *await_init = NULL; if (t_expr == var) - dtor = NULL_TREE; + needs_dtor = false; else { /* Initialize the var from the provided 'o' expression. */ @@ -1615,7 +1609,12 @@ expand_one_await_expression (tree *stmt, tree *await_expr, void *d) destroy_label = build_stmt (loc, LABEL_EXPR, destroy_label); append_to_statement_list (destroy_label, &body_list); if (needs_dtor) - append_to_statement_list (dtor, &body_list); + { + tree dtor = build_special_member_call (var, complete_dtor_identifier, + NULL, await_type, LOOKUP_NORMAL, + tf_warning_or_error); + append_to_statement_list (dtor, &body_list); + } r = build1_loc (loc, GOTO_EXPR, void_type_node, data->cleanup); append_to_statement_list (r, &body_list); @@ -1650,7 +1649,12 @@ expand_one_await_expression (tree *stmt, tree *await_expr, void *d) /* Get a pointer to the revised statment. */ tree *revised = tsi_stmt_ptr (tsi_last (stmt_list)); if (needs_dtor) - append_to_statement_list (dtor, &stmt_list); + { + tree dtor = build_special_member_call (var, complete_dtor_identifier, + NULL, await_type, LOOKUP_NORMAL, + tf_warning_or_error); + append_to_statement_list (dtor, &stmt_list); + } data->index += 2; /* Replace the original statement with the expansion. */ -- 2.7.4