[Ada] Fully propagate representation aspects through renaming

2019-12-16  Eric Botcazou  <ebotcazou@adacore.com>

gcc/ada/

	* sem_ch8.adb (Analyze_Object_Renaming): Set Atomic, Independent
	and Volatile_Full_Access aspects on the entity of the renaming
	the same way as the Volatile aspect is set.
	* sem_util.ads (Is_Atomic_Object_Entity): Move declaration to...
	(Is_Independent_Object): New function.
	(Is_Volatile_Full_Access_Object): Likewise.
	* sem_util.adb (Is_Atomic_Object_Entity): ...here.
	(Prefix_Has_Atomic_Components): Minor tweak.
	(Is_Atomic_Object): Test Is_Atomic on the Etype uniformly.
	(Is_Atomic_Or_VFA_Object): Call Is_Volatile_Full_Access_Object.
	(Is_Independent_Object): New predicate.
	(Is_Subcomponent_Of_Atomic_Object): Remove redundant test.
	(Is_Volatile_Full_Access_Object): New predicate.
	(Is_Volatile_Prefix): Rename into...
	(Prefix_Has_Volatile_Components): ... and call
	Is_Volatile_Object.
	(Object_Has_Volatile_Components): Delete.
	(Is_Volatile_Object): Simplify.
	* gcc-interface/trans.c (node_is_volatile_full_access): Adjust
	comment.

From-SVN: r279429

gcc/ada/ChangeLog

+2019-12-16  Eric Botcazou  <ebotcazou@adacore.com>
+
+	* sem_ch8.adb (Analyze_Object_Renaming): Set Atomic, Independent
+	and Volatile_Full_Access aspects on the entity of the renaming
+	the same way as the Volatile aspect is set.
+	* sem_util.ads (Is_Atomic_Object_Entity): Move declaration to...
+	(Is_Independent_Object): New function.
+	(Is_Volatile_Full_Access_Object): Likewise.
+	* sem_util.adb (Is_Atomic_Object_Entity): ...here.
+	(Prefix_Has_Atomic_Components): Minor tweak.
+	(Is_Atomic_Object): Test Is_Atomic on the Etype uniformly.
+	(Is_Atomic_Or_VFA_Object): Call Is_Volatile_Full_Access_Object.
+	(Is_Independent_Object): New predicate.
+	(Is_Subcomponent_Of_Atomic_Object): Remove redundant test.
+	(Is_Volatile_Full_Access_Object): New predicate.
+	(Is_Volatile_Prefix): Rename into...
+	(Prefix_Has_Volatile_Components): ... and call
+	Is_Volatile_Object.
+	(Object_Has_Volatile_Components): Delete.
+	(Is_Volatile_Object): Simplify.
+	* gcc-interface/trans.c (node_is_volatile_full_access): Adjust
+	comment.
+
 2019-12-16  Bob Duff  <duff@adacore.com>
 
 	* par.adb: Add Scopes function to do range checking on the scope

gcc/ada/gcc-interface/trans.c

@@ -4835,8 +4835,8 @@ node_is_atomic (Node_Id gnat_node)
 }
 
 /* Return true if GNAT_NODE references a Volatile_Full_Access entity.  This is
-   modeled on the Is_VFA_Object predicate of the front-end, but additionally
-   handles explicit dereferences.  */
+   modeled on the Is_Volatile_Full_Access_Object predicate of the front-end,
+   but additionally handles explicit dereferences.  */
 
 static bool
 node_is_volatile_full_access (Node_Id gnat_node)

gcc/ada/sem_ch8.adb

@@ -1358,19 +1358,13 @@ package body Sem_Ch8 is
       end if;
 
       --  The entity of the renaming declaration needs to reflect whether the
-      --  renamed object is volatile. Is_Volatile is set if the renamed object
-      --  is volatile in the RM legality sense.
+      --  renamed object is atomic, independent, volatile or VFA. These flags
+      --  are set on the renamed object in the RM legality sense.
 
+      Set_Is_Atomic               (Id, Is_Atomic_Object (Nam));
+      Set_Is_Independent          (Id, Is_Independent_Object (Nam));
       Set_Is_Volatile             (Id, Is_Volatile_Object (Nam));
-
-      --  Also copy settings of Atomic/Independent/Volatile_Full_Access
-
-      if Is_Entity_Name (Nam) then
-         Set_Is_Atomic               (Id, Is_Atomic      (Entity (Nam)));
-         Set_Is_Independent          (Id, Is_Independent (Entity (Nam)));
-         Set_Is_Volatile_Full_Access (Id,
-           Is_Volatile_Full_Access (Entity (Nam)));
-      end if;
+      Set_Is_Volatile_Full_Access (Id, Is_Volatile_Full_Access_Object (Nam));
 
       --  Treat as volatile if we just set the Volatile flag
 

gcc/ada/sem_util.ads

@@ -1531,11 +1531,7 @@ package Sem_Util is
 
    function Is_Atomic_Object (N : Node_Id) return Boolean;
    --  Determine whether arbitrary node N denotes a reference to an atomic
-   --  object as per Ada RM C.6(7) and the crucial remark in C.6(8).
-
-   function Is_Atomic_Object_Entity (Id : Entity_Id) return Boolean;
-   --  Determine whether arbitrary entity Id denotes an atomic object as per
-   --  Ada RM C.6(7).
+   --  object as per RM C.6(7) and the crucial remark in RM C.6(8).
 
    function Is_Atomic_Or_VFA_Object (N : Node_Id) return Boolean;
    --  Determine whether arbitrary node N denotes a reference to an object
@@ -1749,6 +1745,10 @@ package Sem_Util is
    --  Determine whether arbitrary declaration Decl denotes a generic package,
    --  a generic subprogram or a generic body.
 
+   function Is_Independent_Object (N : Node_Id) return Boolean;
+   --  Determine whether arbitrary node N denotes a reference to an independent
+   --  object as per RM C.6(8).
+
    function Is_Inherited_Operation (E : Entity_Id) return Boolean;
    --  E is a subprogram. Return True is E is an implicit operation inherited
    --  by a derived type declaration.
@@ -1996,7 +1996,7 @@ package Sem_Util is
 
    function Is_Subcomponent_Of_Atomic_Object (N : Node_Id) return Boolean;
    --  Determine whether arbitrary node N denotes a reference to a subcomponent
-   --  of an atomic object as per Ada RM C.6(7).
+   --  of an atomic object as per RM C.6(7).
 
    function Is_Subprogram_Contract_Annotation (Item : Node_Id) return Boolean;
    --  Determine whether aspect specification or pragma Item is one of the
@@ -2095,16 +2095,20 @@ package Sem_Util is
    --  Initialize/Adjust/Finalize subprogram does not override the inherited
    --  one.
 
+   function Is_Volatile_Full_Access_Object (N : Node_Id) return Boolean;
+   --  Determine whether arbitrary node N denotes a reference to an object
+   --  which is Volatile_Full_Access.
+
    function Is_Volatile_Function (Func_Id : Entity_Id) return Boolean;
    --  Determine whether [generic] function Func_Id is subject to enabled
    --  pragma Volatile_Function. Protected functions are treated as volatile
    --  (SPARK RM 7.1.2).
 
    function Is_Volatile_Object (N : Node_Id) return Boolean;
-   --  Determines if the given node denotes an volatile object in the sense of
-   --  the legality checks described in RM C.6(12). Note that the test here is
-   --  for something actually declared as volatile, not for an object that gets
-   --  treated as volatile (see Einfo.Treat_As_Volatile).
+   --  Determine whether arbitrary node N denotes a reference to a volatile
+   --  object as per RM C.6(8). Note that the test here is for something that
+   --  is actually declared as volatile, not for an object that gets treated
+   --  as volatile (see Einfo.Treat_As_Volatile).
 
    generic
       with procedure Handle_Parameter (Formal : Entity_Id; Actual : Node_Id);