[COMMITTED 23/30] ada: Iterator filter ignored on formal loop

["Marc Poulhiès" <poulhies@adacore.com>]

From: Justin Squirek <squirek@adacore.com>

This patch fixs an issue where iterator filters for formal container and
formal container element loops got silently ignored and remained unexpanded.

gcc/ada/

	* exp_ch5.adb (Expand_Formal_Container_Element_Loop): Add
	expansion of filter condition.
	(Expand_Formal_Container_Loop): Add expansion of filter condition.

Tested on x86_64-pc-linux-gnu, committed on master.

---
 gcc/ada/exp_ch5.adb | 45 +++++++++++++++++++++++++++++++++++++--------
 1 file changed, 37 insertions(+), 8 deletions(-)

diff --git a/gcc/ada/exp_ch5.adb b/gcc/ada/exp_ch5.adb
index 2973658ce98..f397086d73a 100644
--- a/gcc/ada/exp_ch5.adb
+++ b/gcc/ada/exp_ch5.adb
@@ -4394,6 +4394,18 @@ package body Exp_Ch5 is
       Reinit_Field_To_Zero (Init_Name, F_SPARK_Pragma_Inherited);
       Mutate_Ekind (Init_Name, E_Loop_Parameter);
 
+      --  Wrap the block statements with the condition specified in the
+      --  iterator filter when one is present.
+
+      if Present (Iterator_Filter (I_Spec)) then
+         pragma Assert (Ada_Version >= Ada_2022);
+         Set_Statements (Handled_Statement_Sequence (N),
+            New_List (Make_If_Statement (Loc,
+              Condition => Iterator_Filter (I_Spec),
+              Then_Statements =>
+                Statements (Handled_Statement_Sequence (N)))));
+      end if;
+
       --  The cursor was marked as a loop parameter to prevent user assignments
       --  to it, however this renders the advancement step illegal as it is not
       --  possible to change the value of a constant. Flag the advancement step
@@ -4436,6 +4448,7 @@ package body Exp_Ch5 is
       Advance   : Node_Id;
       Init      : Node_Id;
       New_Loop  : Node_Id;
+      Block     : Node_Id;
 
    begin
       --  For an element iterator, the Element aspect must be present,
@@ -4456,7 +4469,6 @@ package body Exp_Ch5 is
 
       Build_Formal_Container_Iteration
         (N, Container, Cursor, Init, Advance, New_Loop);
-      Append_To (Stats, Advance);
 
       Mutate_Ekind (Cursor, E_Variable);
       Insert_Action (N, Init);
@@ -4481,13 +4493,30 @@ package body Exp_Ch5 is
             Convert_To_Iterable_Type (Container, Loc),
             New_Occurrence_Of (Cursor, Loc))));
 
-      Set_Statements (New_Loop,
-        New_List
-          (Make_Block_Statement (Loc,
-             Declarations => New_List (Elmt_Decl),
-             Handled_Statement_Sequence =>
-               Make_Handled_Sequence_Of_Statements (Loc,
-                 Statements => Stats))));
+      Block :=
+        Make_Block_Statement (Loc,
+          Declarations => New_List (Elmt_Decl),
+          Handled_Statement_Sequence =>
+            Make_Handled_Sequence_Of_Statements (Loc,
+              Statements => Stats));
+
+      --  Wrap the block statements with the condition specified in the
+      --  iterator filter when one is present.
+
+      if Present (Iterator_Filter (I_Spec)) then
+         pragma Assert (Ada_Version >= Ada_2022);
+         Set_Statements (Handled_Statement_Sequence (Block),
+            New_List (
+              Make_If_Statement (Loc,
+                Condition       => Iterator_Filter (I_Spec),
+                Then_Statements =>
+                  Statements (Handled_Statement_Sequence (Block))),
+              Advance));
+      else
+         Append_To (Stats, Advance);
+      end if;
+
+      Set_Statements (New_Loop, New_List (Block));
 
       --  The element is only modified in expanded code, so it appears as
       --  unassigned to the warning machinery. We must suppress this spurious
-- 
2.45.1