This patch fixes a bug in which if a derived type has a Default_Iterator
specified, and the parent type does not, then a "for ... of" loop causes
the compiler to crash. No small test case available.
Tested on x86_64-pc-linux-gnu, committed on trunk
2017-09-06 Bob Duff <d...@adacore.com>
* exp_ch5.adb (Get_Default_Iterator): Replace
"Assert(False)" with "return Iter", because if an iterable
type is derived from a noniterable one, then we won't find an
overriding or inherited default iterator.
Index: exp_ch5.adb
===================================================================
--- exp_ch5.adb (revision 251767)
+++ exp_ch5.adb (working copy)
@@ -3934,9 +3934,9 @@
function Get_Default_Iterator
(T : Entity_Id) return Entity_Id;
- -- If the container is a derived type, the aspect holds the parent
- -- operation. The required one is a primitive of the derived type
- -- and is either inherited or overridden. Also sets Container_Arg.
+ -- Return the default iterator for a specific type. If the type is
+ -- derived, we return the inherited or overridden one if
+ -- appropriate.
--------------------------
-- Get_Default_Iterator --
@@ -3953,11 +3953,11 @@
begin
Container_Arg := New_Copy_Tree (Container);
- -- A previous version of GNAT allowed indexing aspects to
- -- be redefined on derived container types, while the
- -- default iterator was inherited from the parent type.
- -- This non-standard extension is preserved temporarily for
- -- use by the modelling project under debug flag d.X.
+ -- A previous version of GNAT allowed indexing aspects to be
+ -- redefined on derived container types, while the default
+ -- iterator was inherited from the parent type. This
+ -- nonstandard extension is preserved for use by the
+ -- modelling project under debug flag -gnatd.X.
if Debug_Flag_Dot_XX then
if Base_Type (Etype (Container)) /=
@@ -3995,9 +3995,11 @@
Next_Elmt (Prim);
end loop;
- -- Default iterator must exist
+ -- If we didn't find it, then our parent type is not
+ -- iterable, so we return the Default_Iterator aspect of
+ -- this type.
- pragma Assert (False);
+ return Iter;
-- Otherwise not a derived type
