From 35e8b38a91d9fb49a4759649576f15e76c129d99 Mon Sep 17 00:00:00 2001 From: Jakub Jelinek Date: Fri, 16 Apr 2021 17:37:07 +0200 Subject: [PATCH] c++: Fix empty base stores in cxx_eval_store_expression [PR100111] In r11-6895 handling of empty bases has been fixed such that non-lval stores of empty classes are not added when the type of *valp doesn't match the type of the initializer, but as this testcase shows it is done only when *valp is non-NULL. If it is NULL, we still shouldn't add empty class constructors if the type of the constructor elt *valp points to doesn't match. 2021-04-16 Jakub Jelinek PR c++/100111 * constexpr.c (cxx_eval_store_expression): Don't add CONSTRUCTORs for empty classes into *valp when types don't match even when *valp is NULL. * g++.dg/cpp0x/constexpr-100111.C: New test. --- gcc/cp/constexpr.c | 8 ++++++++ gcc/testsuite/g++.dg/cpp0x/constexpr-100111.C | 7 +++++++ 2 files changed, 15 insertions(+) create mode 100644 gcc/testsuite/g++.dg/cpp0x/constexpr-100111.C diff --git a/gcc/cp/constexpr.c b/gcc/cp/constexpr.c index b74bbac3cd26..0fb0ab44b39e 100644 --- a/gcc/cp/constexpr.c +++ b/gcc/cp/constexpr.c @@ -5538,6 +5538,14 @@ cxx_eval_store_expression (const constexpr_ctx *ctx, tree t, CONSTRUCTOR_NO_CLEARING (*valp) = CONSTRUCTOR_NO_CLEARING (init); } + else if (TREE_CODE (init) == CONSTRUCTOR + && !same_type_ignoring_top_level_qualifiers_p (TREE_TYPE (init), + type)) + { + /* See above on initialization of empty bases. */ + gcc_assert (is_empty_class (TREE_TYPE (init)) && !lval); + return init; + } else *valp = init; diff --git a/gcc/testsuite/g++.dg/cpp0x/constexpr-100111.C b/gcc/testsuite/g++.dg/cpp0x/constexpr-100111.C new file mode 100644 index 000000000000..446d21d03c5a --- /dev/null +++ b/gcc/testsuite/g++.dg/cpp0x/constexpr-100111.C @@ -0,0 +1,7 @@ +// PR c++/100111 +// { dg-do compile { target c++11 } } +// { dg-options "-fno-elide-constructors" } + +struct A {}; +struct B : A { int b; constexpr B (A x) : A(x), b() {} }; +struct C { B c; constexpr C () : c({}) {} } d; -- 2.47.2