Hi!
We ICE on the following testcase, because DECL_INITIAL (decl) is
error_mark_node due to previously reported error and
cxx_eval_outermost_constant_expr is unhappy if ctx.ctor is not
a CONSTRUCTOR, but error_mark_node.
If the initializer is invalid, it should have been diagnosed already and
there is no need to try to evaluate constexpr dtor on it.
Bootstrapped/regtested on x86_64-linux and i686-linux, ok for trunk?
2019-11-08 Jakub Jelinek <ja...@redhat.com>
PR c++/92414
* constexpr.c (cxx_constant_dtor): Don't call
cxx_eval_outermost_constant_expr if DECL_INITIAL is erroneous.
* g++.dg/cpp2a/constexpr-dtor4.C: New test.
--- gcc/cp/constexpr.c.jj 2019-11-06 08:58:37.000000000 +0100
+++ gcc/cp/constexpr.c 2019-11-07 22:13:58.395840756 +0100
@@ -6024,7 +6024,8 @@ cxx_constant_value (tree t, tree decl)
void
cxx_constant_dtor (tree t, tree decl)
{
- cxx_eval_outermost_constant_expr (t, false, true, true, true, decl);
+ if (!error_operand_p (DECL_INITIAL (decl)))
+ cxx_eval_outermost_constant_expr (t, false, true, true, true, decl);
}
/* Helper routine for fold_simple function. Either return simplified
--- gcc/testsuite/g++.dg/cpp2a/constexpr-dtor4.C.jj 2019-11-07
22:16:56.943181785 +0100
+++ gcc/testsuite/g++.dg/cpp2a/constexpr-dtor4.C 2019-11-07
22:18:16.752993443 +0100
@@ -0,0 +1,15 @@
+// PR c++/92414
+// { dg-do compile { target c++2a } }
+
+struct A { virtual void foo (); };
+
+struct B : A {
+ constexpr B (int); // { dg-warning "used but never defined" }
+ constexpr ~B () { }
+};
+
+struct D : B {
+ constexpr D () : B (42) { } // { dg-error "used before its definition" }
+};
+
+constexpr D d; // { dg-message "in 'constexpr' expansion of" }
Jakub
