constexpr.c (maybe_constant_init): Pull out TARGET_EXPR_INITIAL.

	* constexpr.c (maybe_constant_init): Pull out TARGET_EXPR_INITIAL.

	(cxx_eval_outermost_constant_expr): Don't return a CONSTRUCTOR
	with CONSTRUCTOR_NO_IMPLICIT_ZERO.
	(cxx_eval_call_expression): Clear CONSTRUCTOR_NO_IMPLICIT_ZERO.

From-SVN: r241531

gcc/cp/ChangeLog

+2016-10-25  Jason Merrill  <jason@redhat.com>
+
+	* constexpr.c (maybe_constant_init): Pull out TARGET_EXPR_INITIAL.
+	(cxx_eval_outermost_constant_expr): Don't return a CONSTRUCTOR
+	with CONSTRUCTOR_NO_IMPLICIT_ZERO.
+	(cxx_eval_call_expression): Clear CONSTRUCTOR_NO_IMPLICIT_ZERO.
+
 2016-10-25  Jakub Jelinek  <jakub@redhat.com>
 
 	* parser.c (cp_parser_postfix_expression): Adding missing break;.

gcc/cp/constexpr.c

@@ -1665,6 +1665,10 @@ cxx_eval_call_expression (const constexpr_ctx *ctx, tree t,
 	entry->result = result;
     }
 
+  /* The result of a constexpr function must be completely initialized.  */
+  if (TREE_CODE (result) == CONSTRUCTOR)
+    CONSTRUCTOR_NO_IMPLICIT_ZERO (result) = false;
+
   pop_cx_call_context ();
   return unshare_constructor (result);
 }
@@ -4483,6 +4487,16 @@ cxx_eval_outermost_constant_expr (tree t, bool allow_non_constant,
       non_constant_p = true;
     }
 
+  if (TREE_CODE (r) == CONSTRUCTOR
+      && CONSTRUCTOR_NO_IMPLICIT_ZERO (r))
+    {
+      if (!allow_non_constant)
+	error ("%qE is not a constant expression because it refers to "
+	       "an incompletely initialized variable", t);
+      TREE_CONSTANT (r) = false;
+      non_constant_p = true;
+    }
+
   /* Technically we should check this for all subexpressions, but that
      runs into problems with our internal representation of pointer
      subtraction and the 5.19 rules are still in flux.  */
@@ -4781,6 +4795,8 @@ maybe_constant_init (tree t, tree decl)
     t = TREE_OPERAND (t, 0);
   if (TREE_CODE (t) == INIT_EXPR)
     t = TREE_OPERAND (t, 1);
+  if (TREE_CODE (t) == TARGET_EXPR)
+    t = TARGET_EXPR_INITIAL (t);
   if (!potential_nondependent_static_init_expression (t))
     /* Don't try to evaluate it.  */;
   else

gcc/testsuite/g++.dg/cpp0x/constexpr-static12.C

+// { dg-do compile { target c++11 } }
+// { dg-final { scan-assembler-not "_ZNSt10unique_ptrC1Ei" } }
+
+namespace std {
+  struct unique_ptr {
+    constexpr unique_ptr(int) : p() { }
+    ~unique_ptr() { }
+    void* p;
+  };
+}
+
+void f()
+{
+  static std::unique_ptr p(1);
+}
+
+int main()
+{
+  f();
+}