diff --git a/gcc/cp/pt.c b/gcc/cp/pt.c index 68ee71397d0f..2763aa15f1f8 100644 --- a/gcc/cp/pt.c +++ b/gcc/cp/pt.c @@ -19433,8 +19433,13 @@ tsubst_lambda_expr (tree t, tree args, tsubst_flags_t complain, tree in_decl) the purposes of template argument deduction. */ complain = tf_warning_or_error; - tsubst_expr (DECL_SAVED_TREE (oldfn), args, complain, r, - /*constexpr*/false); + tree saved = DECL_SAVED_TREE (oldfn); + if (TREE_CODE (saved) == BIND_EXPR && BIND_EXPR_BODY_BLOCK (saved)) + /* We already have a body block from start_lambda_function, we don't + need another to confuse NRV (91217). */ + saved = BIND_EXPR_BODY (saved); + + tsubst_expr (saved, args, complain, r, /*constexpr*/false); finish_lambda_function (body); diff --git a/gcc/testsuite/g++.dg/opt/nrv20.C b/gcc/testsuite/g++.dg/opt/nrv20.C new file mode 100644 index 000000000000..ade0c28824a7 --- /dev/null +++ b/gcc/testsuite/g++.dg/opt/nrv20.C @@ -0,0 +1,20 @@ +// PR c++/91217 +// { dg-do compile { target c++11 } } +// { dg-additional-options -fdump-tree-gimple } +// { dg-final { scan-tree-dump-not " = a" "gimple" } } + +struct A +{ + int ar[42]; +}; + +template +A f() +{ + return [] { A a; return a; }(); +} + +int main() +{ + f(); +}