[Ada] Ada_2020 AI12-0250 : Implement Iterator filters.

gcc/ada/

	* par.adb (P_Iterator_Specification): Make public for use in
	other parser subprograms.
	* par-ch4.adb (P_Iterated_Component_Association): In Ada_2020,
	recognize use of Iterator_Specification in an element iterator.
	To simplify disambiguation between the two iterator forms, mark
	the component association as carrying an Iterator_Specification
	only when the element iterator (using "OF") is used.
	* par-ch5.adb (P_Loop_Parameter_Specification): In Ada_2020,
	parse iterator filter when present.
	(P_Iterator_Specification): Ditto.  Remove declaration of
	P_Iterator_Specification, now in parent unit.
	* exp_ch5.adb (Expand_N_Loop_Statement): Apply Iterator filter
	when present.
	(Expand_Iterator_Loop_Over_Array): Ditto.
	(Expand_Iterator_Loop_Over_Container): Ditto.
	* sem_aggr.adb (Resolve_Array_Aggregate): Emit error nessage if
	an iterated component association includes a iterator
	specificcation with an element iterator, i.e. one that uses the
	OF keyword.
	* sem_ch5.adb (Analyze_Iterator_Specification): Analyze Iterator
	filter when present.
	(Analyze_Loop_Parameter_Specification): Ditto.
	* sinfo.adb: Suprogram bodies for new syntactic element
	Iterator_Filter.
	* sinfo.ads: Add Iterator_Filter to relevant nodes.  Structure
	of Component_Association and Iteroted_Component_Association
	nodes is modified to take into account the possible  presence of
	an iterator specification in the latter.

1 files changed, 22 insertions, 2 deletions

diff --git a/gcc/ada/sinfo.adb b/gcc/ada/sinfo.adb
index 7368db6..7284a06 100644
--- a/gcc/ada/sinfo.adb
+++ b/gcc/ada/sinfo.adb
@@ -2223,6 +2223,15 @@ package body Sinfo is
       return Flag5 (N);
    end Is_Write;
 
+   function Iterator_Filter
+     (N : Node_Id) return Node_Id is
+   begin
+      pragma Assert (False
+        or else NT (N).Nkind = N_Iterator_Specification
+        or else NT (N).Nkind = N_Loop_Parameter_Specification);
+      return Node3 (N);
+   end Iterator_Filter;
+
    function Iteration_Scheme
       (N : Node_Id) return Node_Id is
    begin
@@ -2235,6 +2244,7 @@ package body Sinfo is
      (N : Node_Id) return Node_Id is
    begin
       pragma Assert (False
+        or else NT (N).Nkind = N_Iterated_Component_Association
         or else NT (N).Nkind = N_Iteration_Scheme
         or else NT (N).Nkind = N_Quantified_Expression);
       return Node2 (N);
@@ -2358,7 +2368,7 @@ package body Sinfo is
       pragma Assert (False
         or else NT (N).Nkind = N_Component_Association
         or else NT (N).Nkind = N_Iterated_Component_Association);
-      return List2 (N);
+      return List5 (N);
    end Loop_Actions;
 
    function Loop_Parameter_Specification
@@ -5700,6 +5710,15 @@ package body Sinfo is
       Set_Flag5 (N, Val);
    end Set_Is_Write;
 
+   procedure Set_Iterator_Filter
+     (N : Node_Id; Val : Node_Id) is
+   begin
+      pragma Assert (False
+        or else NT (N).Nkind = N_Iterator_Specification
+        or else NT (N).Nkind = N_Loop_Parameter_Specification);
+      Set_Node3_With_Parent (N, Val);
+   end Set_Iterator_Filter;
+
    procedure Set_Iteration_Scheme
       (N : Node_Id; Val : Node_Id) is
    begin
@@ -5712,6 +5731,7 @@ package body Sinfo is
      (N : Node_Id; Val : Node_Id) is
    begin
       pragma Assert (False
+        or else NT (N).Nkind = N_Iterated_Component_Association
         or else NT (N).Nkind = N_Iteration_Scheme
         or else NT (N).Nkind = N_Quantified_Expression);
       Set_Node2_With_Parent (N, Val);
@@ -5835,7 +5855,7 @@ package body Sinfo is
       pragma Assert (False
         or else NT (N).Nkind = N_Component_Association
         or else NT (N).Nkind = N_Iterated_Component_Association);
-      Set_List2 (N, Val); -- semantic field, no parent set
+      Set_List5 (N, Val); -- semantic field, no parent set
    end Set_Loop_Actions;
 
    procedure Set_Loop_Parameter_Specification