re PR c++/92414 (internal compiler error: tree check: expected constructor, have…

re PR c++/92414 (internal compiler error: tree check: expected constructor, have error_mark in cxx_eval_store_expression, at cp/constexpr.c:4009)

	PR c++/92414
	* constexpr.c (cxx_eval_outermost_constant_expr): If DECL_INITIAL
	on object is erroneous, return t without trying to evaluate
	a constexpr dtor.

	* g++.dg/cpp2a/constexpr-dtor4.C: New test.

From-SVN: r278468

gcc/cp/ChangeLog

+2019-11-19  Jakub Jelinek  <jakub@redhat.com>
+
+	PR c++/92414
+	* constexpr.c (cxx_eval_outermost_constant_expr): If DECL_INITIAL
+	on object is erroneous, return t without trying to evaluate
+	a constexpr dtor.
+
 2019-11-12  Jason Merrill  <jason@redhat.com>
 
 	* call.c (same_fn_or_template): Change to cand_parms_match.

gcc/cp/constexpr.c

@@ -5834,6 +5834,8 @@ cxx_eval_outermost_constant_expr (tree t, bool allow_non_constant,
 	  gcc_assert (object && VAR_P (object));
 	  gcc_assert (DECL_DECLARED_CONSTEXPR_P (object));
 	  gcc_assert (DECL_INITIALIZED_BY_CONSTANT_EXPRESSION_P (object));
+	  if (error_operand_p (DECL_INITIAL (object)))
+	    return t;
 	  ctx.ctor = unshare_expr (DECL_INITIAL (object));
 	  TREE_READONLY (ctx.ctor) = false;
 	  /* Temporarily force decl_really_constant_value to return false

gcc/testsuite/ChangeLog

+2019-11-19  Jakub Jelinek  <jakub@redhat.com>
+
+	PR c++/92414
+	* g++.dg/cpp2a/constexpr-dtor4.C: New test.
+
 2019-11-19  Dragan Mladjenovic  <dmladjenovic@wavecomp.com>
 
 	* gcc.target/mips/msa-ds.c: New test.
 
 2019-11-19  Richard Sandiford  <richard.sandiford@arm.com>
-gcc/
+
 	Revert:
 	2019-11-18  Richard Sandiford  <richard.sandiford@arm.com>
 

gcc/testsuite/g++.dg/cpp2a/constexpr-dtor4.C

+// 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" }