re PR c++/49924 ([C++0X] [constexpr] can't initialize a non-static member array of...

	PR c++/49924
	* semantics.c (cxx_eval_vec_init_1): Fix logic.

From-SVN: r177073

diff --git a/gcc/cp/ChangeLog b/gcc/cp/ChangeLog
index b40b290fb50e21839489d459f93ef8b919eede7f..6dda726a1a0422abc9cbb96a8d313300a5b5c2d5 100644 (file)
--- a/gcc/cp/ChangeLog
+++ b/gcc/cp/ChangeLog
@@ -1,5 +1,8 @@
 2011-08-01  Jason Merrill  <jason@redhat.com>
 
+       PR c++/49924
+       * semantics.c (cxx_eval_vec_init_1): Fix logic.
+
        PR c++/49813
        * semantics.c (potential_constant_expression_1): Allow any builtin.
        (morally_constexpr_builtin_function_p): Remove.

diff --git a/gcc/cp/semantics.c b/gcc/cp/semantics.c
index 47b714fc04d78a33d3bd0b300dbc7e8878810691..0b2a96fa4d2de1bb3979913560dac37835bf82f5 100644 (file)
--- a/gcc/cp/semantics.c
+++ b/gcc/cp/semantics.c
@@ -6651,6 +6651,7 @@ cxx_eval_vec_init_1 (const constexpr_call *call, tree atype, tree init,
   tree elttype = TREE_TYPE (atype);
   int max = tree_low_cst (array_type_nelts (atype), 0);
   VEC(constructor_elt,gc) *n = VEC_alloc (constructor_elt, gc, max + 1);
+  bool pre_init = false;
   int i;
 
   /* For the default constructor, build up a call to the default
@@ -6658,8 +6659,15 @@ cxx_eval_vec_init_1 (const constexpr_call *call, tree atype, tree init,
      here, as for a constructor to be constexpr, all members must be
      initialized, which for a defaulted default constructor means they must
      be of a class type with a constexpr default constructor.  */
-  if (value_init)
-    gcc_assert (!init);
+  if (TREE_CODE (elttype) == ARRAY_TYPE)
+    /* We only do this at the lowest level.  */;
+  else if (value_init)
+    {
+      init = build_value_init (elttype, tf_warning_or_error);
+      init = cxx_eval_constant_expression
+           (call, init, allow_non_constant, addr, non_constant_p);
+      pre_init = true;
+    }
   else if (!init)
     {
       VEC(tree,gc) *argvec = make_tree_vector ();
@@ -6669,6 +6677,7 @@ cxx_eval_vec_init_1 (const constexpr_call *call, tree atype, tree init,
       release_tree_vector (argvec);
       init = cxx_eval_constant_expression (call, init, allow_non_constant,
                                           addr, non_constant_p);
+      pre_init = true;
     }
 
   if (*non_constant_p && !allow_non_constant)
@@ -6690,17 +6699,14 @@ cxx_eval_vec_init_1 (const constexpr_call *call, tree atype, tree init,
                                         allow_non_constant, addr,
                                         non_constant_p);
        }
-      else if (value_init)
+      else if (pre_init)
        {
-         eltinit = build_value_init (elttype, tf_warning_or_error);
-         eltinit = cxx_eval_constant_expression
-           (call, eltinit, allow_non_constant, addr, non_constant_p);
-       }
-      else if (TREE_CODE (init) == CONSTRUCTOR)
-       {
-         /* Initializing an element using the call to the default
-            constructor we just built above.  */
-         eltinit = unshare_expr (init);
+         /* Initializing an element using value or default initialization
+            we just pre-built above.  */
+         if (i == 0)
+           eltinit = init;
+         else
+           eltinit = unshare_expr (init);
        }
       else
        {

diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog
index aa7354b19b98c93597217e64d99f245470779f22..e3626441401784ce15b49017d54c04c37132d483 100644 (file)
--- a/gcc/testsuite/ChangeLog
+++ b/gcc/testsuite/ChangeLog
@@ -1,5 +1,8 @@
 2011-08-01  Jason Merrill  <jason@redhat.com>
 
+       PR c++/49924
+       * g++.dg/cpp0x/constexpr-array4.C: New.
+
        PR c++/49813
        * g++.dg/cpp0x/constexpr-builtin1.C: New.
 

diff --git a/gcc/testsuite/g++.dg/cpp0x/constexpr-array4.C b/gcc/testsuite/g++.dg/cpp0x/constexpr-array4.C
new file mode 100644 (file)
index 0000000..9aeb75d
--- /dev/null
+++ b/gcc/testsuite/g++.dg/cpp0x/constexpr-array4.C
@@ -0,0 +1,14 @@
+// PR c++/49924
+// { dg-options -std=c++0x }
+
+struct A { constexpr A() { } };
+
+struct B {
+  A array[1]; //non-static member array of a literal type w constexpr ctor
+  constexpr B() : array{} { } // here is the problem
+};
+
+int main()
+{
+  constexpr B b{};  // won't compile
+}