In early versions of Ada, an illegal iterator of the form "for X in S" where
S is an array, is most likely an attempt to iterate over the range of S, and
this is the appropriate error message to emit. In Ada 2012, there is a new
iterator specification form "for E of S", and the error message must indicate
that the new form uses a different keyword.
Compiling the following program in Ada 2012 mode must yield:
main.adb:7:14: to iterate over the elements of an array, use "of"
main.adb:15:14: to iterate over the elements of an array, use "of"
Compiling with an earlier version of the language must yield;
main.adb:7:14: missing Range attribute in iteration over an array
main.adb:15:14: missing Range attribute in iteration over an array
---
with Ada.Text_IO;
with Tools;
with Type_Declarations;
package body Main is
procedure Process is
begin
for Index in Tools.Result loop
Ada.Text_IO.Put_Line (Tools.Result (Index)'Img);
end loop;
end Process;
procedure Process2 is
Ct : constant Type_Declarations.Array_Type := Tools.Result;
begin
for Index in Ct loop
Ada.Text_IO.Put_Line (Tools.Result (Index)'Img);
end loop;
end Process2;
end Main;
--
with Type_Declarations;
package Tools is
function Result
return Type_Declarations.Array_Type;
end Tools;
---
package Type_Declarations is
type Integer_Type is new Integer;
Ct_Max : constant := 40;
type Large_Index_Type is new Integer range 0 .. Ct_Max;
subtype Index_Type is Large_Index_Type range 1 .. Large_Index_Type'Last;
type Array_Type is array (Index_Type range <>) of Integer_Type;
end Type_Declarations;
Tested on x86_64-pc-linux-gnu, committed on trunk
2011-09-05 Ed Schonberg <[email protected]>
* sem_ch5.adb (Analyze_Iteration_Specification): Improve error
message on an iterator over an array.
Index: sem_ch5.adb
===================================================================
--- sem_ch5.adb (revision 178448)
+++ sem_ch5.adb (working copy)
@@ -2336,13 +2336,18 @@
if Is_Array_Type (Typ) then
if Of_Present (N) then
Set_Etype (Def_Id, Component_Type (Typ));
+
+ elsif Ada_Version < Ada_2012 then
+ Error_Msg_N
+ ("missing Range attribute in iteration over an array", N);
+
else
Error_Msg_N
("to iterate over the elements of an array, use OF", N);
-- Prevent cascaded errors
- Set_Ekind (Def_Id, E_Constant);
+ Set_Ekind (Def_Id, E_Loop_Parameter);
Set_Etype (Def_Id, Etype (First_Index (Typ)));
end if;
