From 0fa9495553e0e0f4ceb764880b5bdd8ade197382 Mon Sep 17 00:00:00 2001 From: Jason Merrill Date: Mon, 5 Jun 2023 23:58:32 -0400 Subject: c++: fix contracts with NRV The NRV implementation was blindly replacing the operand of RETURN_EXPR, clobbering anything that check_return_expr might have added on to the actual initialization, such as checking the postcondition. gcc/cp/ChangeLog: * semantics.cc (finalize_nrv_r): [RETURN_EXPR]: Only replace the INIT_EXPR. gcc/testsuite/ChangeLog: * g++.dg/contracts/contracts-post7.C: New test. --- gcc/cp/semantics.cc | 12 ++++++++++-- 1 file changed, 10 insertions(+), 2 deletions(-) (limited to 'gcc/cp') diff --git a/gcc/cp/semantics.cc b/gcc/cp/semantics.cc index c045146..c94ea09 100644 --- a/gcc/cp/semantics.cc +++ b/gcc/cp/semantics.cc @@ -4940,9 +4940,17 @@ finalize_nrv_r (tree* tp, int* walk_subtrees, void* data) *walk_subtrees = 0; /* Change all returns to just refer to the RESULT_DECL; this is a nop, but differs from using NULL_TREE in that it indicates that we care - about the value of the RESULT_DECL. */ + about the value of the RESULT_DECL. But preserve anything appended + by check_return_expr. */ else if (TREE_CODE (*tp) == RETURN_EXPR) - TREE_OPERAND (*tp, 0) = dp->result; + { + tree *p = &TREE_OPERAND (*tp, 0); + while (TREE_CODE (*p) == COMPOUND_EXPR) + p = &TREE_OPERAND (*p, 0); + gcc_checking_assert (TREE_CODE (*p) == INIT_EXPR + && TREE_OPERAND (*p, 0) == dp->result); + *p = dp->result; + } /* Change all cleanups for the NRV to only run when an exception is thrown. */ else if (TREE_CODE (*tp) == CLEANUP_STMT -- cgit v1.1