From 324276ff9b1aa5128e5cb9f5d43182d1ebab0752 Mon Sep 17 00:00:00 2001 From: Iain Sandoe Date: Tue, 2 Jun 2020 16:47:54 +0100 Subject: coroutines: Wrap co_await in a target expr where needed [PR95050] Since the co_await expression is mostly opaque to the existing machinery, we were hiding the details of the await_resume return value. If that needs to be wrapped in a target expression, then emulate this with the whole co_await. Similarly, if the await expression we build in response to co_await p.yield_value (e) is wrapped in a target expression, then we need to transfer that wrapper to the resultant CO_YIELD_EXPR (which is, itself, just a proxy for the underlying co_await). gcc/cp/ChangeLog: PR c++/95050 * coroutines.cc (build_co_await): Wrap the co_await expression in a TARGET_EXPR, where needed. (finish_co_yield_expr): Likewise. gcc/testsuite/ChangeLog: PR c++/95050 * g++.dg/coroutines/pr95050.C: New test. --- gcc/cp/coroutines.cc | 29 +++++++++++++++++++++++++++-- 1 file changed, 27 insertions(+), 2 deletions(-) (limited to 'gcc/cp') diff --git a/gcc/cp/coroutines.cc b/gcc/cp/coroutines.cc index e90387b..e689625 100644 --- a/gcc/cp/coroutines.cc +++ b/gcc/cp/coroutines.cc @@ -816,6 +816,12 @@ build_co_await (location_t loc, tree a, suspend_point_kind suspend_kind) tree awaiter_calls = make_tree_vec (3); TREE_VEC_ELT (awaiter_calls, 0) = awrd_call; /* await_ready(). */ TREE_VEC_ELT (awaiter_calls, 1) = awsp_call; /* await_suspend(). */ + tree te = NULL_TREE; + if (TREE_CODE (awrs_call) == TARGET_EXPR) + { + te = awrs_call; + awrs_call = TREE_OPERAND (awrs_call, 1); + } TREE_VEC_ELT (awaiter_calls, 2) = awrs_call; /* await_resume(). */ tree await_expr = build5_loc (loc, CO_AWAIT_EXPR, @@ -823,7 +829,13 @@ build_co_await (location_t loc, tree a, suspend_point_kind suspend_kind) a, e_proxy, o, awaiter_calls, build_int_cst (integer_type_node, (int) suspend_kind)); - return convert_from_reference (await_expr); + if (te) + { + TREE_OPERAND (te, 1) = await_expr; + await_expr = te; + } + tree t = convert_from_reference (await_expr); + return t; } tree @@ -960,8 +972,21 @@ finish_co_yield_expr (location_t kw, tree expr) tree op = build_co_await (kw, yield_call, CO_YIELD_SUSPEND_POINT); if (op != error_mark_node) { - op = build2_loc (kw, CO_YIELD_EXPR, TREE_TYPE (op), expr, op); + if (REFERENCE_REF_P (op)) + op = TREE_OPERAND (op, 0); + /* If the await expression is wrapped in a TARGET_EXPR, then transfer + that wrapper to the CO_YIELD_EXPR, since this is just a proxy for + its contained await. Otherwise, just build the CO_YIELD_EXPR. */ + if (TREE_CODE (op) == TARGET_EXPR) + { + tree t = TREE_OPERAND (op, 1); + t = build2_loc (kw, CO_YIELD_EXPR, TREE_TYPE (t), expr, t); + TREE_OPERAND (op, 1) = t; + } + else + op = build2_loc (kw, CO_YIELD_EXPR, TREE_TYPE (op), expr, op); TREE_SIDE_EFFECTS (op) = 1; + op = convert_from_reference (op); } return op; -- cgit v1.1