ada: Clean up vanishing entity fields

Fix all the failures caused by enabling Check_Vanishing_Fields on
entities in all cases except the case of converting to or from E_Void.
But leave Check_Vanishing_Fields disabled by default (controlled by
-gnatd_v flag), because it might be too slow even for assertions-on
mode, and we should deal with the E_Void cases eventually.

The failures are fixed either by adding calls to Reinit_Field_To_Zero,
or by changing which entities have which fields.

Note that in a series of Reinit_Field_To_Zero calls, the optional
Old_Ekind parameter is only useful on the first such call.

gcc/ada/

	* atree.adb
	(Check_Vanishing_Fields): Disable the check for "root/base type
	only" fields. This is a bug fix -- if we're checking some subtype
	S, we don't want to reach over to the root or base type and
	Reinit_Field_To_Zero of that, thus modifying the field for lots of
	subtypes other than S. Disable in the to/from E_Void cases. Misc
	cleanup.
	* gen_il-gen-gen_entities.adb: Define First_Entity, Last_Entity,
	and Stored_Constraint for all type entities, because there are too
	many cases where Reinit_Field_To_Zero would otherwise be needed.
	In any case, it seems cleaner to have First_Entity and Last_Entity
	defined in the same entity kinds.
	* einfo.ads:
	(First_Entity, Last_Entity, Stored_Constraint): Update comments to
	reflect gen_il-gen-gen_entities.adb changes.
	(Lit_Hash): Add missing "[root type only]" comment.
	* exp_ch5.adb: Add Reinit_Field_To_Zero calls for vanishing
	fields.
	* sem_ch10.adb: Likewise.
	* sem_ch6.adb: Likewise.
	* sem_ch7.adb: Likewise.
	* sem_ch8.adb: Likewise.
	* sem_ch3.adb: Likewise. Also remove now-unnecessary
	Reinit_Field_To_Zero calls.

1 files changed, 7 insertions, 22 deletions

diff --git a/gcc/ada/sem_ch3.adb b/gcc/ada/sem_ch3.adb
index 299ea6e..66013ca 100644
--- a/gcc/ada/sem_ch3.adb
+++ b/gcc/ada/sem_ch3.adb
@@ -6462,13 +6462,6 @@ package body Sem_Ch3 is
       end if;
 
       if Nkind (Def) = N_Constrained_Array_Definition then
-
-         if Ekind (T) in Incomplete_Or_Private_Kind then
-            Reinit_Field_To_Zero (T, F_Stored_Constraint);
-         else
-            pragma Assert (Ekind (T) = E_Void);
-         end if;
-
          --  Establish Implicit_Base as unconstrained base type
 
          Implicit_Base := Create_Itype (E_Array_Type, P, Related_Id, 'B');
@@ -6509,13 +6502,6 @@ package body Sem_Ch3 is
       --  Unconstrained array case
 
       else pragma Assert (Nkind (Def) = N_Unconstrained_Array_Definition);
-
-         if Ekind (T) in Incomplete_Or_Private_Kind then
-            Reinit_Field_To_Zero (T, F_Stored_Constraint);
-         else
-            pragma Assert (Ekind (T) = E_Void);
-         end if;
-
          Mutate_Ekind                 (T, E_Array_Type);
          Reinit_Size_Align            (T);
          Set_Etype                    (T, T);
@@ -10030,9 +10016,9 @@ package body Sem_Ch3 is
       --  Set common attributes
 
       if Ekind (Derived_Type) in Incomplete_Or_Private_Kind
-        and then Ekind (Parent_Base) in Modular_Integer_Kind | Array_Kind
+        and then Ekind (Parent_Base) in Elementary_Kind
       then
-         Reinit_Field_To_Zero (Derived_Type, F_Stored_Constraint);
+         Reinit_Field_To_Zero (Derived_Type, F_Discriminant_Constraint);
       end if;
 
       Set_Scope                  (Derived_Type, Current_Scope);
@@ -17367,8 +17353,8 @@ package body Sem_Ch3 is
             Error_Msg_N ("type cannot be used in its own definition", Indic);
          end if;
 
-         Mutate_Ekind     (T, Ekind (Parent_Type));
-         Set_Etype        (T, Any_Type);
+         Mutate_Ekind (T, Ekind (Parent_Type));
+         Set_Etype (T, Any_Type);
          Set_Scalar_Range (T, Scalar_Range (Any_Type));
 
          --  Initialize the list of primitive operations to an empty list,
@@ -19726,6 +19712,9 @@ package body Sem_Ch3 is
          if Ekind (CW_Type) in E_Task_Type | E_Protected_Type then
             Reinit_Field_To_Zero (CW_Type, F_SPARK_Aux_Pragma_Inherited);
          end if;
+
+      elsif Ekind (CW_Type) = E_Record_Type then
+         Reinit_Field_To_Zero (CW_Type, F_Corresponding_Concurrent_Type);
       end if;
 
       Mutate_Ekind                    (CW_Type, E_Class_Wide_Type);
@@ -20112,10 +20101,6 @@ package body Sem_Ch3 is
 
       Analyze_And_Resolve (Mod_Expr, Any_Integer);
 
-      if Ekind (T) in Incomplete_Or_Private_Kind then
-         Reinit_Field_To_Zero (T, F_Stored_Constraint);
-      end if;
-
       Set_Etype (T, T);
       Mutate_Ekind (T, E_Modular_Integer_Type);
       Reinit_Alignment (T);