===================================================================
@@ -3864,10 +3864,14 @@
Set_Debug_Info_Needed (Id);
-- If the container does not have a variable indexing aspect,
- -- the element is a constant in the loop.
+ -- the element is a constant in the loop. The container itself
+ -- may be constant, in which case the element is a constant as
+ -- well. The container has been rewritten as a call to Iterate,
+ -- so examine original node.
if No (Find_Value_Of_Aspect
(Container_Typ, Aspect_Variable_Indexing))
+ or else not Is_Variable (Original_Node (Container))
then
Set_Ekind (Id, E_Constant);
end if;
This patch adds a legality check to element iterators over containers: the element is a constant if the container object is a constant, even if the container type has a Variable_Indexing aspect. Compiling the following must be rejected with: strange_behavior.adb:12:07: left hand side of assignment must be a variable --- with Ada.Containers.Doubly_Linked_Lists; procedure Strange_Behavior is package Integer_Lists is new Ada.Containers.Doubly_Linked_Lists (Element_Type => Integer); L : constant Integer_Lists.List := Integer_Lists.Empty_List; begin for Item of L loop Item := 0; end loop; end Strange_Behavior; Tested on x86_64-pc-linux-gnu, committed on trunk 2015-10-26 Ed Schonberg <schonberg@adacore.com> * exp_ch5.adb (Expand_Iterator_Loop_Over_Container): For an element iterator loop, the element is a constant if the container object is a constant, even if the container type has a Variable_Indexing aspect.