From 125db6a1c6aca542c14b326facdcaf9a1fca8b52 Mon Sep 17 00:00:00 2001 From: Jason Merrill Date: Tue, 11 Apr 2017 17:07:32 -0400 Subject: [PATCH] PR c++/80294 - ICE with constexpr and inheritance. * constexpr.c (reduced_constant_expression_p): A null constructor element is non-constant. (cxx_eval_indirect_ref): Don't VERIFY_CONSTANT before returning an empty base. From-SVN: r246858 --- gcc/cp/ChangeLog | 8 ++++++++ gcc/cp/constexpr.c | 13 ++++++++----- gcc/testsuite/g++.dg/cpp1y/constexpr-empty3.C | 14 ++++++++++++++ 3 files changed, 30 insertions(+), 5 deletions(-) create mode 100644 gcc/testsuite/g++.dg/cpp1y/constexpr-empty3.C diff --git a/gcc/cp/ChangeLog b/gcc/cp/ChangeLog index c06b505..80247bf 100644 --- a/gcc/cp/ChangeLog +++ b/gcc/cp/ChangeLog @@ -1,3 +1,11 @@ +2017-04-11 Jason Merrill + + PR c++/80294 - ICE with constexpr and inheritance. + * constexpr.c (reduced_constant_expression_p): + A null constructor element is non-constant. + (cxx_eval_indirect_ref): Don't VERIFY_CONSTANT before + returning an empty base. + 2017-04-11 Jakub Jelinek PR c++/80370 diff --git a/gcc/cp/constexpr.c b/gcc/cp/constexpr.c index 3ca3560..9dde4a4 100644 --- a/gcc/cp/constexpr.c +++ b/gcc/cp/constexpr.c @@ -1716,8 +1716,13 @@ reduced_constant_expression_p (tree t) /* And we need to handle PTRMEM_CST wrapped in a CONSTRUCTOR. */ tree elt; unsigned HOST_WIDE_INT idx; FOR_EACH_CONSTRUCTOR_VALUE (CONSTRUCTOR_ELTS (t), idx, elt) - if (!reduced_constant_expression_p (elt)) - return false; + { + if (!elt) + /* We're in the middle of initializing this element. */ + return false; + if (!reduced_constant_expression_p (elt)) + return false; + } return true; default: @@ -3153,12 +3158,10 @@ cxx_eval_indirect_ref (const constexpr_ctx *ctx, tree t, if (*non_constant_p) return t; - /* If we're pulling out the value of an empty base, make sure - that the whole object is constant and then return an empty + /* If we're pulling out the value of an empty base, just return an empty CONSTRUCTOR. */ if (empty_base && !lval) { - VERIFY_CONSTANT (r); r = build_constructor (TREE_TYPE (t), NULL); TREE_CONSTANT (r) = true; } diff --git a/gcc/testsuite/g++.dg/cpp1y/constexpr-empty3.C b/gcc/testsuite/g++.dg/cpp1y/constexpr-empty3.C new file mode 100644 index 0000000..37e4a53 --- /dev/null +++ b/gcc/testsuite/g++.dg/cpp1y/constexpr-empty3.C @@ -0,0 +1,14 @@ +// PR c++/80294 +// { dg-do compile { target c++14 } } +// { dg-final { scan-assembler-not "static_init" } } + +struct A { + constexpr int f() { A a = *this; return 42; } +}; +struct B: A +{ + int i; + constexpr B(): i(f()) {} +}; + +B b; -- 2.7.4