From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mout-p-201.mailbox.org (mout-p-201.mailbox.org [IPv6:2001:67c:2050:0:465::201]) by sourceware.org (Postfix) with ESMTPS id 7FAC13858CDB for ; Sat, 3 Sep 2022 20:58:08 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.4.1 sourceware.org 7FAC13858CDB Authentication-Results: sourceware.org; dmarc=pass (p=reject dis=none) header.from=aarsen.me Authentication-Results: sourceware.org; spf=pass smtp.mailfrom=aarsen.me Received: from smtp2.mailbox.org (smtp2.mailbox.org [10.196.197.2]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange ECDHE (P-384) server-signature RSA-PSS (4096 bits) server-digest SHA256) (No client certificate requested) by mout-p-201.mailbox.org (Postfix) with ESMTPS id 4MKnDY3bbrz9sR6; Sat, 3 Sep 2022 22:58:05 +0200 (CEST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=aarsen.me; s=MBO0001; t=1662238685; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding; bh=UIYjhHtBZnJE02tYN1DPhS4vDXKn94EU70HvJKPwhu0=; b=Ne/1YbeGNi4kWe+C/dZpGdb3KpI9Iw07L03oR+/TyIUtmbYavmx4c8FjB+KbngjODIgINJ 1NRAX5l8rjuX8bikyGBVhuuMPSHmw1ODicZlBtf9LsSmBaNkZ/UDJmdDfPgsRRSjg0aSTH G04qyCabnepR0sxp0+Nahgfawpr8Ztmhfku8QBuoLdRbIeiKeLsuaZs6JrruA1nDfqXo7F vKTLApBjbMOe7xUQ+5iojser3sOzKAjicCZ95Dm3nVUNn9uqdmmnsau9tWbq8DZRznpFf4 Z+Lm61ndG7+segtZ8VUdjA/Gn/kQuME64fRw/ZdSPXu6LGkk9P+aNCuSJnb91g== From: =?UTF-8?q?Arsen=20Arsenovi=C4=87?= To: gcc-patches@gcc.gnu.org Cc: jason@redhat.com, nathan@acm.org, iain@sandoe.co.uk, =?UTF-8?q?Arsen=20Arsenovi=C4=87?= Subject: [PATCH] coroutines: Wrap awaiting if/swich in a BIND_EXPR, if needed [PR106188] Date: Sat, 3 Sep 2022 22:57:29 +0200 Message-Id: <20220903205728.944089-1-arsen@aarsen.me> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit X-Spam-Status: No, score=-10.0 required=5.0 tests=BAYES_00,DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,DKIM_VALID_EF,GIT_PATCH_0,KAM_INFOUSMEBIZ,RCVD_IN_DNSWL_LOW,SPF_HELO_NONE,SPF_PASS,TXREP,T_SCC_BODY_TEXT_LINE autolearn=ham autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on server2.sourceware.org List-Id: In the edge case of a coroutine not containing any locals, the ifcd/swch temporaries would get added to the coroutine frame, corrupting its layout. We can prevent this by ensuring that in cases where the scope of the if/switch is the same as the coroutine frame one, we insert a wrapping BIND_EXPR and try again. PR c++/106188 - [coroutines] Incorrect frame layout after transforming conditional statement without top-level bind expression PR c++/106713 - [11/12/13 Regression] Coroutine regression in GCC 11.3.0: if (co_await ...) crashes with a jump to ud2 since r12-3529-g70ee703c479081ac gcc/cp/ChangeLog: PR c++/106188 PR c++/106713 * coroutines.cc (struct susp_frame_data): Add fn_body for informing the await_statement_walker of the coroutine body. (maybe_add_bind): New function. (await_statement_walker): Call maybe_add_bind when necessary. (morph_fn_to_coro): Pass fnbody into susp_frame_data. gcc/testsuite/ChangeLog: * g++.dg/coroutines/pr106188.C: New test. Signed-off-by: Arsen Arsenović --- gcc/cp/coroutines.cc | 45 ++++++++++++++++++++-- gcc/testsuite/g++.dg/coroutines/pr106188.C | 35 +++++++++++++++++ 2 files changed, 77 insertions(+), 3 deletions(-) create mode 100644 gcc/testsuite/g++.dg/coroutines/pr106188.C diff --git a/gcc/cp/coroutines.cc b/gcc/cp/coroutines.cc index edb3b706ddc..2e88fb99d7d 100644 --- a/gcc/cp/coroutines.cc +++ b/gcc/cp/coroutines.cc @@ -2586,6 +2586,7 @@ struct susp_frame_data bool captures_temporary; /* This expr captures temps by ref. */ bool needs_truth_if_exp; /* We must expand a truth_if expression. */ bool has_awaiter_init; /* We must handle initializing an awaiter. */ + tree *fn_body; /* Original function body */ }; /* If this is an await expression, then count it (both uniquely within the @@ -3326,6 +3327,33 @@ add_var_to_bind (tree& bind, tree var_type, return newvar; } +/* Helper to ensure we have at least one bind to add vars to. */ +static bool +maybe_add_bind(susp_frame_data *awpts, tree *stmt, location_t sloc) +{ + /* bind_stack is already asserted to be nonempty */ + tree &bind = awpts->bind_stack->last(); + gcc_checking_assert(TREE_CODE (*awpts->fn_body) == BIND_EXPR); + if (BIND_EXPR_VARS (bind) != BIND_EXPR_VARS (*awpts->fn_body)) + { + /* Alright, we have a unique (enough) scope, bail early. */ + return false; + } + + /* In this case, we'd be pushing variables to the start of the coroutine + * unless we add a new BIND_EXPR here. + */ + tree ifsw_bind = build3_loc (sloc, BIND_EXPR, void_type_node, + NULL, NULL, NULL); + BIND_EXPR_BODY (ifsw_bind) = *stmt; + *stmt = ifsw_bind; + /* We don't push this BIND_EXPR to the walkers bind stack, it will be handled + * by a call to cp_walk_tree, since we start the next walk off from this + * bind node. + */ + return true; +} + /* Helper to build and add if (!cond) break; */ static void @@ -3456,6 +3484,12 @@ await_statement_walker (tree *stmt, int *do_subtree, void *d) return NULL_TREE; /* Nothing special to do here. */ gcc_checking_assert (!awpts->bind_stack->is_empty()); + location_t sloc = EXPR_LOCATION (IF_COND (if_stmt)); + if (maybe_add_bind (awpts, stmt, sloc)) + { + *do_subtree = false; /* Done inside maybe_add_bind. */ + return cp_walk_tree (stmt, await_statement_walker, awpts, NULL); + } tree& bind_expr = awpts->bind_stack->last (); tree newvar = add_var_to_bind (bind_expr, boolean_type_node, "ifcd", awpts->cond_number++); @@ -3464,7 +3498,6 @@ await_statement_walker (tree *stmt, int *do_subtree, void *d) if (TREE_CODE (cond_inner) == CLEANUP_POINT_EXPR) cond_inner = TREE_OPERAND (cond_inner, 0); add_decl_expr (newvar); - location_t sloc = EXPR_LOCATION (IF_COND (if_stmt)); /* We want to initialize the new variable with the expression that contains the await(s) and potentially also needs to have truth_if expressions expanded. */ @@ -3640,6 +3673,12 @@ await_statement_walker (tree *stmt, int *do_subtree, void *d) return NULL_TREE; /* Nothing special to do here. */ gcc_checking_assert (!awpts->bind_stack->is_empty()); + location_t sloc = EXPR_LOCATION (SWITCH_STMT_COND (sw_stmt)); + if (maybe_add_bind (awpts, stmt, sloc)) + { + *do_subtree = false; /* Done inside maybe_add_bind. */ + return cp_walk_tree (stmt, await_statement_walker, awpts, NULL); + } /* Build a variable to hold the condition, this will be included in the frame as a local var. */ tree& bind_expr = awpts->bind_stack->last (); @@ -3652,7 +3691,6 @@ await_statement_walker (tree *stmt, int *do_subtree, void *d) tree cond_inner = SWITCH_STMT_COND (sw_stmt); if (TREE_CODE (cond_inner) == CLEANUP_POINT_EXPR) cond_inner = TREE_OPERAND (cond_inner, 0); - location_t sloc = EXPR_LOCATION (SWITCH_STMT_COND (sw_stmt)); tree new_s = build2_loc (sloc, INIT_EXPR, sw_type, newvar, cond_inner); finish_expr_stmt (new_s); @@ -4477,7 +4515,8 @@ morph_fn_to_coro (tree orig, tree *resumer, tree *destroyer) vars) they will get added to the coro frame along with other locals. */ susp_frame_data body_aw_points = {&field_list, handle_type, fs_label, NULL, NULL, 0, 0, - hash_set (), NULL, NULL, 0, false, false, false}; + hash_set (), NULL, NULL, 0, false, false, false, + &fnbody}; body_aw_points.block_stack = make_tree_vector (); body_aw_points.bind_stack = make_tree_vector (); body_aw_points.to_replace = make_tree_vector (); diff --git a/gcc/testsuite/g++.dg/coroutines/pr106188.C b/gcc/testsuite/g++.dg/coroutines/pr106188.C new file mode 100644 index 00000000000..1de3d4cceca --- /dev/null +++ b/gcc/testsuite/g++.dg/coroutines/pr106188.C @@ -0,0 +1,35 @@ +// { dg-additional-options "-std=c++20 -w" } +// { dg-do run } +// test case from pr106188, w/o workaround +#include + +struct task { + struct promise_type { + task get_return_object() { return task{}; } + void return_void() {} + void unhandled_exception() {} + auto initial_suspend() noexcept { return std::suspend_never{}; } + auto final_suspend() noexcept { return std::suspend_never{}; } + }; +}; + +struct suspend_and_resume { + bool await_ready() const { return false; } + void await_suspend(std::coroutine_handle<> h) { h.resume(); } + void await_resume() {} +}; + +task f() { + if (co_await suspend_and_resume{}, false) {} +} + +task g() { + switch (co_await suspend_and_resume{}, 0) { + default: break; + } +} + +int main() { + f(); + g(); +} -- 2.35.1