einfo.adb (Non_Limited_View): Applies to abstract states.

2014-01-20  Hristian Kirtchev  <kirtchev@adacore.com>

	* einfo.adb (Non_Limited_View): Applies to abstract states.
	(Set_From_Limited_With): Applies to abstract states.
	(Set_Non_Limited_View): Applies to abstract states.
	(Write_Field17): Output the non-limited view of an abstract state.
	* einfo.ads: Update the comment on usage and occurrences in
	nodes for attributes From_Limited_With and Non_Limited_View.
	* sem_aux.adb (Available_View): This routine can now handle
	abstract states.
	* sem_aux.ads (Available_View): This routine can now handle
	abstract states. Update the comment on usage.
	* sem_ch8.adb (Find_Expanded_Name): Handle abstract views
	of states and variables.
	(In_Pragmas_Depends_Or_Global): New routine.
	* sem_ch10.adb (Build_Limited_Views): Implement
	abstract (limited) views of variables and states.
	(Build_Shadow_Entity): This routine is now a procedure. Add
	formal parameter Shadow. Update the comment on usage. Add
	context-specific decoration for states and variables.
	(Decorate_State): New routine.	(Decorate_Variable): New routine.
	(Find_And_Process_States): New routine.
	(Process_Declarations): Renamed to Process_Declarations_And_States.
	(Process_Declarations_And_States): Add formal parameters
	Pack and Create_Abstract_Views. Update the comment on usage.
	(Process_States): New routine.
	* sem_prag.adb (Check_Dependency_Clause): Handle abstract
	views of states and variables. Match the abstract view of a state
	against its corresponding non-abstract view.
	(Is_Matching_Input):
	Handle abstract views of states and variables. Match the abstract
	view of a state against its corresponding non-abstract view.
	(Process_Global_Item): Handle abstract views of states and
	variables.

From-SVN: r206808

gcc/ada/ChangeLog

+2014-01-20  Hristian Kirtchev  <kirtchev@adacore.com>
+
+	* einfo.adb (Non_Limited_View): Applies to abstract states.
+	(Set_From_Limited_With): Applies to abstract states.
+	(Set_Non_Limited_View): Applies to abstract states.
+	(Write_Field17): Output the non-limited view of an abstract state.
+	* einfo.ads: Update the comment on usage and occurrences in
+	nodes for attributes From_Limited_With and Non_Limited_View.
+	* sem_aux.adb (Available_View): This routine can now handle
+	abstract states.
+	* sem_aux.ads (Available_View): This routine can now handle
+	abstract states. Update the comment on usage.
+	* sem_ch8.adb (Find_Expanded_Name): Handle abstract views
+	of states and variables.
+	(In_Pragmas_Depends_Or_Global): New routine.
+	* sem_ch10.adb (Build_Limited_Views): Implement
+	abstract (limited) views of variables and states.
+	(Build_Shadow_Entity): This routine is now a procedure. Add
+	formal parameter Shadow. Update the comment on usage. Add
+	context-specific decoration for states and variables.
+	(Decorate_State): New routine.	(Decorate_Variable): New routine.
+	(Find_And_Process_States): New routine.
+	(Process_Declarations): Renamed to Process_Declarations_And_States.
+	(Process_Declarations_And_States): Add formal parameters
+	Pack and Create_Abstract_Views. Update the comment on usage.
+	(Process_States): New routine.
+	* sem_prag.adb (Check_Dependency_Clause): Handle abstract
+	views of states and variables. Match the abstract view of a state
+	against its corresponding non-abstract view.
+	(Is_Matching_Input):
+	Handle abstract views of states and variables. Match the abstract
+	view of a state against its corresponding non-abstract view.
+	(Process_Global_Item): Handle abstract views of states and
+	variables.
+
 2014-01-20  Bob Duff  <duff@adacore.com>
 
 	* sem_ch10.adb (Expand_With_Clause): Don't

gcc/ada/einfo.adb

@@ -2497,7 +2497,8 @@ package body Einfo is
 
    function Non_Limited_View (Id : E) return E is
    begin
-      pragma Assert (Ekind (Id) in Incomplete_Kind);
+      pragma Assert
+        (Ekind (Id) in Incomplete_Kind or else Ekind (Id) = E_Abstract_State);
       return Node17 (Id);
    end Non_Limited_View;
 
@@ -3865,7 +3866,8 @@ package body Einfo is
 
    procedure Set_From_Limited_With (Id : E; V : B := True) is
    begin
-      pragma Assert (Is_Type (Id) or else Ekind (Id) = E_Package);
+      pragma Assert
+        (Is_Type (Id) or else Ekind_In (Id, E_Abstract_State, E_Package));
       Set_Flag159 (Id, V);
    end Set_From_Limited_With;
 
@@ -5172,7 +5174,8 @@ package body Einfo is
 
    procedure Set_Non_Limited_View (Id : E; V : E) is
    begin
-      pragma Assert (Ekind (Id) in Incomplete_Kind);
+      pragma Assert
+        (Ekind (Id) in Incomplete_Kind or else Ekind (Id) = E_Abstract_State);
       Set_Node17 (Id, V);
    end Set_Non_Limited_View;
 
@@ -8787,7 +8790,8 @@ package body Einfo is
          when Modular_Integer_Kind                         =>
             Write_Str ("Modulus");
 
-         when E_Incomplete_Type                            =>
+         when E_Abstract_State                             |
+              E_Incomplete_Type                            =>
             Write_Str ("Non_Limited_View");
 
          when E_Incomplete_Subtype                         =>

gcc/ada/einfo.ads

@@ -1316,10 +1316,11 @@ package Einfo is
 --       Freeze for further details.
 
 --    From_Limited_With (Flag159)
---       Defined in package and type entities. Set to True when the related
---       entity is generated by the expansion of a limited with clause. Such
---       an entity is said to be a "shadow" - it acts as the incomplete view
---       of a type by inheriting relevant attributes from the said type.
+--       Defined in abtract states, package and type entities. Set to True when
+--       the related entity is generated by the expansion of a limited with
+--       clause. Such an entity is said to be a "shadow" - it acts as the
+--       abstract view of a state or variable or as the incomplete view of a
+--       type by inheriting relevant attributes from the said entity.
 
 --    Full_View (Node11)
 --       Defined in all type and subtype entities and in deferred constants.
@@ -3262,9 +3263,9 @@ package Einfo is
 --       types if the modulus value is other than a power of 2.
 
 --    Non_Limited_View (Node17)
---       Defined in incomplete types that are the shadow entities created
---       when analyzing a limited_with_clause (Ada 2005: AI-50217). Points to
---       the defining entity in the original declaration.
+--       Defined in abstract states and incomplete types that act as shadow
+--       entities created when analysing a limited with clause (Ada 2005:
+--       AI-50217). Points to the defining entity of the original declaration.
 
 --    Nonzero_Is_True (Flag162) [base type only]
 --       Defined in enumeration types. Set if any non-zero value is to be
@@ -5120,6 +5121,8 @@ package Einfo is
    --    Refinement_Constituents             (Elist8)
    --    Refined_State                       (Node10)
    --    Body_References                     (Elist16)
+   --    Non_Limited_View                    (Node17)
+   --    From_Limited_With                   (Flag159)
    --    Has_Body_References                 (Flag264)
    --    Has_Visible_Refinement              (Flag263)
    --    Has_Non_Null_Refinement             (synth)

gcc/ada/sem_aux.adb

@@ -76,28 +76,35 @@ package body Sem_Aux is
    -- Available_View --
    --------------------
 
-   function Available_View (Typ : Entity_Id) return Entity_Id is
+   function Available_View (Ent : Entity_Id) return Entity_Id is
    begin
-      if Is_Incomplete_Type (Typ)
-        and then Present (Non_Limited_View (Typ))
+      --  Obtain the non-limited (non-abstract) view of a state or variable
+
+      if Ekind (Ent) = E_Abstract_State
+        and then Present (Non_Limited_View (Ent))
       then
-         --  The non-limited view may itself be an incomplete type, in which
-         --  case get its full view.
+         return Non_Limited_View (Ent);
+
+      --  The non-limited view of an incomplete type may itself be incomplete
+      --  in which case obtain its full view.
 
-         return Get_Full_View (Non_Limited_View (Typ));
+      elsif Is_Incomplete_Type (Ent)
+        and then Present (Non_Limited_View (Ent))
+      then
+         return Get_Full_View (Non_Limited_View (Ent));
 
-      --  If it is class_wide, check whether the specific type comes from
-      --  A limited_with.
+      --  If it is class_wide, check whether the specific type comes from a
+      --  limited_with.
 
-      elsif Is_Class_Wide_Type (Typ)
-        and then Is_Incomplete_Type (Etype (Typ))
-        and then From_Limited_With (Etype (Typ))
-        and then Present (Non_Limited_View (Etype (Typ)))
+      elsif Is_Class_Wide_Type (Ent)
+        and then Is_Incomplete_Type (Etype (Ent))
+        and then From_Limited_With (Etype (Ent))
+        and then Present (Non_Limited_View (Etype (Ent)))
       then
-         return Class_Wide_Type (Non_Limited_View (Etype (Typ)));
+         return Class_Wide_Type (Non_Limited_View (Etype (Ent)));
 
       else
-         return Typ;
+         return Ent;
       end if;
    end Available_View;
 

gcc/ada/sem_aux.ads

@@ -90,12 +90,10 @@ package Sem_Aux is
    --  subtype then it returns the subtype or type from which the subtype was
    --  obtained, otherwise it returns Empty.
 
-   function Available_View (Typ : Entity_Id) return Entity_Id;
-   --  Typ is typically a type that has the With_Type flag set. Returns the
-   --  non-limited view of the type, if available, otherwise the type itself.
-   --  For class-wide types, there is no direct link in the tree, so we have
-   --  to retrieve the class-wide type of the non-limited view of the Etype.
-   --  Returns the argument unchanged if it is not one of these cases.
+   function Available_View (Ent : Entity_Id) return Entity_Id;
+   --  Ent denotes an abstract state or a type that may come from a limited
+   --  with clause. Return the non-limited view of Ent if there is one or Ent
+   --  if this is not the case.
 
    function Constant_Value (Ent : Entity_Id) return Node_Id;
    --  Ent is a variable, constant, named integer, or named real entity. This

gcc/ada/sem_ch8.adb

@@ -5171,11 +5171,51 @@ package body Sem_Ch8 is
    --  the scope of its declaration.
 
    procedure Find_Expanded_Name (N : Node_Id) is
+      function In_Pragmas_Depends_Or_Global (N : Node_Id) return Boolean;
+      --  Determine whether an arbitrary node N appears in pragmas [Refined_]
+      --  Depends or [Refined_]Global.
+
+      ----------------------------------
+      -- In_Pragmas_Depends_Or_Global --
+      ----------------------------------
+
+      function In_Pragmas_Depends_Or_Global (N : Node_Id) return Boolean is
+         Par : Node_Id;
+
+      begin
+         --  Climb the parent chain looking for a pragma
+
+         Par := N;
+         while Present (Par) loop
+            if Nkind (Par) = N_Pragma
+              and then Nam_In (Pragma_Name (Par), Name_Depends,
+                                                  Name_Global,
+                                                  Name_Refined_Depends,
+                                                  Name_Refined_Global)
+            then
+               return True;
+
+            --  Prevent the search from going too far
+
+            elsif Is_Body_Or_Package_Declaration (Par) then
+               return False;
+            end if;
+
+            Par := Parent (Par);
+         end loop;
+
+         return False;
+      end In_Pragmas_Depends_Or_Global;
+
+      --  Local variables
+
       Selector  : constant Node_Id := Selector_Name (N);
       Candidate : Entity_Id        := Empty;
       P_Name    : Entity_Id;
       Id        : Entity_Id;
 
+   --  Start of processing for Find_Expanded_Name
+
    begin
       P_Name := Entity (Prefix (N));
 
@@ -5210,6 +5250,27 @@ package body Sem_Ch8 is
                Candidate        := Id;
                Is_New_Candidate := True;
 
+               --  Handle abstract views of states and variables. These are
+               --  acceptable only when the reference to the view appears in
+               --  pragmas [Refined_]Depends and [Refined_]Global.
+
+               if Ekind (Id) = E_Abstract_State
+                 and then From_Limited_With (Id)
+                 and then Present (Non_Limited_View (Id))
+               then
+                  if In_Pragmas_Depends_Or_Global (N) then
+                     Candidate        := Non_Limited_View (Id);
+                     Is_New_Candidate := True;
+
+                  --  Hide the candidate because it is not used in a proper
+                  --  context.
+
+                  else
+                     Candidate        := Empty;
+                     Is_New_Candidate := False;
+                  end if;
+               end if;
+
             --  Ada 2005 (AI-217): Handle shadow entities associated with types
             --  declared in limited-withed nested packages. We don't need to
             --  handle E_Incomplete_Subtype entities because the entities in
@@ -5221,9 +5282,8 @@ package body Sem_Ch8 is
             --  The non-limited view may itself be incomplete, in which case
             --  get the full view if available.
 
-            elsif From_Limited_With (Id)
-              and then Is_Type (Id)
-              and then Ekind (Id) = E_Incomplete_Type
+            elsif Ekind (Id) = E_Incomplete_Type
+              and then From_Limited_With (Id)
               and then Present (Non_Limited_View (Id))
               and then Scope (Non_Limited_View (Id)) = P_Name
             then
@@ -5528,8 +5588,7 @@ package body Sem_Ch8 is
          else
             Error_Msg_N
               ("limited withed package can only be used to access "
-               & "incomplete types",
-                N);
+               & "incomplete types", N);
          end if;
       end if;
 

gcc/ada/sem_prag.adb

@@ -19905,7 +19905,7 @@ package body Sem_Prag is
          function Output_Constituents (State_Id : Entity_Id) return Elist_Id;
          --  Given a state denoted by State_Id, return a list of all output
          --  constituents that may be referenced within Refined_Depends. The
-         --  contents of the list depend on whethe Refined_Global is present.
+         --  contents of the list depend on whether Refined_Global is present.
 
          procedure Report_Unused_Constituents (Constits : Elist_Id);
          --  Emit errors for all constituents found in list Constits
@@ -19989,7 +19989,10 @@ package body Sem_Prag is
                --  Remaining cases are formal parameters, variables, and states
 
                else
-                  Dep_Id := Entity_Of (Dep_Input);
+                  --  Handle abstract views of states and variables generated
+                  --  for limited with clauses.
+
+                  Dep_Id := Available_View (Entity_Of (Dep_Input));
 
                   --  Inspect all inputs of the refinement clause and attempt
                   --  to match against the inputs of the dependence clause.
@@ -20061,6 +20064,18 @@ package body Sem_Prag is
                                  Remove (Ref_Input);
                               end if;
                            end if;
+
+                        --  The abstract view of a state matches its
+                        --  corresponding non-abstract view:
+
+                        --    Depends         => (<output> => Lim_Pack.State)
+                        --    Refined_Depends => (<output> => State)
+
+                        elsif Is_Entity_Name (Ref_Input)
+                          and then Entity_Of (Ref_Input) = Dep_Id
+                        then
+                           Remove (Ref_Input);
+                           return True;
                         end if;
 
                      --  Formal parameters and variables are matched on
@@ -20364,7 +20379,11 @@ package body Sem_Prag is
             --  The remaining cases are formal parameters, variables and states
 
             elsif Is_Entity_Name (Dep_Output) then
-               Dep_Id := Entity_Of (Dep_Output);
+
+               --  Handle abstract views of states and variables generated for
+               --  limited with clauses.
+
+               Dep_Id := Available_View (Entity_Of (Dep_Output));
 
                if Ekind (Dep_Id) = E_Abstract_State then
 
@@ -20446,6 +20465,18 @@ package body Sem_Prag is
                            Remove (Out_Constits, Ref_Id);
                         end if;
                      end if;
+
+                  --  The abstract view of a state matches is corresponding
+                  --  non-abstract view:
+
+                  --    Depends         => (Lim_Pack.State => <input>)
+                  --    Refined_Depends => (State          => <input>)
+
+                  elsif Is_Entity_Name (Ref_Output)
+                    and then Entity_Of (Ref_Output) = Dep_Id
+                  then
+                     Matching_Clause := Ref_Clause;
+                     exit;
                   end if;
 
                --  Formal parameters and variables match if their inputs match
@@ -22127,7 +22158,9 @@ package body Sem_Prag is
          -------------------------
 
          procedure Process_Global_Item (Item : Node_Id; Mode : Name_Id) is
-            Item_Id : constant Entity_Id := Entity_Of (Item);
+            Item_Id : constant Entity_Id := Available_View (Entity_Of (Item));
+            --  The above handles abstract views of variables and states built
+            --  for limited with clauses.
 
          begin
             --  Signal that the global list contains at least one abstract