[Ada] Legality of protected subp. implementing interface operations
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Message ID 20190819083901.GA33486@adacore.com
State New
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Series
  • [Ada] Legality of protected subp. implementing interface operations
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Commit Message

Pierre-Marie de Rodat Aug. 19, 2019, 8:39 a.m. UTC
This patch refines the predicate that implements rule in RM 9.4 (11.9/2)

Compiling b94.ads must yield:

   b94.ads:11:17: illegal overriding of subprogram inherited from interface
   b94.ads:11:17: first formal of "N" declared at line 8 must be of mode
     "out", "in out" or access-to-variable

----
package B94 is

   type Prot2_Int is protected interface;
   procedure  J (PI : in     Prot2_Int; N : in Integer)  is null;
   procedure  K (PI : in out Prot2_Int; N : in Integer)  is null;
   procedure  L (PI :    out Prot2_Int; N : in Integer)  is null;
   procedure  M (PI : access Prot2_Int; N : in Integer)  is null;
   procedure  N (PI : access constant Prot2_Int; N : in Integer)  is null;

   protected type Protected_2 is new Prot2_Int with
      procedure N (N : in Integer);                   -- ERROR: {7;1}
   end Protected_2;

end B94;

Tested on x86_64-pc-linux-gnu, committed on trunk

2019-08-19  Ed Schonberg  <schonberg@adacore.com>

gcc/ada/

	* sem_ch6.adb (Check_Synchronized_Overriding): Complete
	predicate that applies legality check in 9.4 (11.9/2): if an
	inherited subprogram is implemented by a protected procedure or
	entry, its first paarameter must be out, in_out or
	access_to_varible.

Patch
diff mbox series

--- gcc/ada/sem_ch6.adb
+++ gcc/ada/sem_ch6.adb
@@ -7034,6 +7034,11 @@  package body Sem_Ch6 is
       In_Scope    : Boolean;
       Typ         : Entity_Id;
 
+      function Is_Valid_Formal (F : Entity_Id) return Boolean;
+      --  Predicate for legality rule in 9.4 (11.9/2): If an inherited
+      --  subprogram is implemented by a protected procedure or entry,
+      --  its first parameter must be out, in out, or access-to-variable.
+
       function Matches_Prefixed_View_Profile
         (Prim_Params  : List_Id;
          Iface_Params : List_Id) return Boolean;
@@ -7042,6 +7047,19 @@  package body Sem_Ch6 is
       --  Iface_Params. Also determine if the type of first parameter of
       --  Iface_Params is an implemented interface.
 
+      ----------------------
+      --  Is_Valid_Formal --
+      ----------------------
+
+      function Is_Valid_Formal (F : Entity_Id) return Boolean is
+      begin
+         return
+           Ekind_In (F, E_In_Out_Parameter, E_Out_Parameter)
+             or else
+               (Nkind (Parameter_Type (Parent (F))) = N_Access_Definition
+                 and then not Constant_Present (Parameter_Type (Parent (F))));
+      end Is_Valid_Formal;
+
       -----------------------------------
       -- Matches_Prefixed_View_Profile --
       -----------------------------------
@@ -7295,10 +7313,7 @@  package body Sem_Ch6 is
 
                   if Ekind_In (Candidate, E_Entry, E_Procedure)
                     and then Is_Protected_Type (Typ)
-                    and then Ekind (Formal) /= E_In_Out_Parameter
-                    and then Ekind (Formal) /= E_Out_Parameter
-                    and then Nkind (Parameter_Type (Parent (Formal))) /=
-                                                       N_Access_Definition
+                    and then not Is_Valid_Formal (Formal)
                   then
                      null;