Replace fat accesses by bounds accesses

translate: separate info for signals from object.
Improve some error messages.

14 files changed, 675 insertions, 667 deletions

diff --git a/src/vhdl/translate/trans-chap2.adb b/src/vhdl/translate/trans-chap2.adb
index a43179e..b3055f4 100644
--- a/src/vhdl/translate/trans-chap2.adb
+++ b/src/vhdl/translate/trans-chap2.adb
@@ -111,30 +111,38 @@ package body Trans.Chap2 is
    --  Return the type of a subprogram interface.
    --  Return O_Tnode_Null if the parameter is passed through the
    --  interface record.
-   function Translate_Interface_Type (Inter : Iir) return O_Tnode
+   function Translate_Interface_Type (Inter : Iir; Is_Foreign : Boolean)
+                                     return O_Tnode
    is
-      Mode  : Object_Kind_Type;
       Tinfo : constant Type_Info_Acc := Get_Info (Get_Type (Inter));
+      Mode  : Object_Kind_Type;
+      By_Addr : Boolean;
    begin
-      case Get_Kind (Inter) is
+      --  Mechanism.
+      case Type_Mode_Valid (Tinfo.Type_Mode) is
+         when Type_Mode_Pass_By_Copy =>
+            By_Addr := False;
+         when Type_Mode_Pass_By_Address =>
+            By_Addr := True;
+      end case;
+
+      case Iir_Kinds_Interface_Object_Declaration (Get_Kind (Inter)) is
          when Iir_Kind_Interface_Constant_Declaration
-            | Iir_Kind_Interface_Variable_Declaration
             | Iir_Kind_Interface_File_Declaration =>
             Mode := Mode_Value;
+         when Iir_Kind_Interface_Variable_Declaration =>
+            Mode := Mode_Value;
+            if Is_Foreign and then Get_Mode (Inter) in Iir_Out_Modes then
+               By_Addr := True;
+            end if;
          when Iir_Kind_Interface_Signal_Declaration =>
             Mode := Mode_Signal;
-         when others =>
-            Error_Kind ("translate_interface_type", Inter);
-      end case;
-      case Tinfo.Type_Mode is
-         when Type_Mode_Unknown =>
-            raise Internal_Error;
-         when Type_Mode_By_Value =>
-            return Tinfo.Ortho_Type (Mode);
-         when Type_Mode_By_Copy
-            | Type_Mode_By_Ref =>
-            return Tinfo.Ortho_Ptr_Type (Mode);
       end case;
+      if By_Addr then
+         return Tinfo.Ortho_Ptr_Type (Mode);
+      else
+         return Tinfo.Ortho_Type (Mode);
+      end if;
    end Translate_Interface_Type;
 
    procedure Translate_Subprogram_Declaration (Spec : Iir)
@@ -142,6 +150,7 @@ package body Trans.Chap2 is
       Info : constant Subprg_Info_Acc := Get_Info (Spec);
       Is_Func : constant Boolean :=
         Get_Kind (Spec) = Iir_Kind_Function_Declaration;
+      Is_Foreign : constant Boolean := Get_Foreign_Flag (Spec);
       Inter : Iir;
       Arg_Info : Ortho_Info_Acc;
       Tinfo : Type_Info_Acc;
@@ -151,13 +160,14 @@ package body Trans.Chap2 is
       Rtype : Iir;
       Id : O_Ident;
       Storage : O_Storage;
-      Foreign : Foreign_Info_Type := Foreign_Bad;
+      Foreign : Foreign_Info_Type;
    begin
       --  Set the identifier prefix with the subprogram identifier and
       --  overload number if any.
       Push_Subprg_Identifier (Spec, Mark);
 
-      if Get_Foreign_Flag (Spec) then
+      --  Create the subprogram identifier.
+      if Is_Foreign then
          --  Special handling for foreign subprograms.
          Foreign := Translate_Foreign_Id (Spec);
          case Foreign.Kind is
@@ -172,6 +182,7 @@ package body Trans.Chap2 is
          end case;
          Storage := O_Storage_External;
       else
+         Foreign := Foreign_Bad;
          Id := Create_Identifier;
          Storage := Global_Storage;
       end if;
@@ -207,13 +218,13 @@ package body Trans.Chap2 is
          --  gather them in a record.  An access to the record is then
          --  passed to the procedure.
          Inter := Get_Interface_Declaration_Chain (Spec);
-         if Inter /= Null_Iir then
+         if Inter /= Null_Iir and then not Is_Foreign then
             Start_Record_Type (El_List);
             while Inter /= Null_Iir loop
                Arg_Info := Add_Info (Inter, Kind_Interface);
                New_Record_Field (El_List, Arg_Info.Interface_Field,
                                  Create_Identifier_Without_Prefix (Inter),
-                                 Translate_Interface_Type (Inter));
+                                 Translate_Interface_Type (Inter, False));
                Inter := Get_Chain (Inter);
             end loop;
             --  Declare the record type and an access to the record.
@@ -241,19 +252,20 @@ package body Trans.Chap2 is
       end if;
 
       --  Instance parameter if any.
-      if not Get_Foreign_Flag (Spec) then
+      if not Is_Foreign then
          Subprgs.Create_Subprg_Instance (Interface_List, Spec);
       end if;
 
       --  Translate interfaces.
-      if Is_Func then
+      if Is_Func or else Is_Foreign then
          Inter := Get_Interface_Declaration_Chain (Spec);
          while Inter /= Null_Iir loop
             --  Create the info.
             Arg_Info := Add_Info (Inter, Kind_Interface);
             Arg_Info.Interface_Field := O_Fnode_Null;
 
-            Arg_Info.Interface_Type := Translate_Interface_Type (Inter);
+            Arg_Info.Interface_Type :=
+              Translate_Interface_Type (Inter, Is_Foreign);
             New_Interface_Decl
               (Interface_List, Arg_Info.Interface_Node,
                Create_Identifier_Without_Prefix (Inter),
@@ -264,7 +276,7 @@ package body Trans.Chap2 is
       Finish_Subprogram_Decl (Interface_List, Info.Ortho_Func);
 
       --  Call the hook for foreign subprograms.
-      if Get_Foreign_Flag (Spec) and then Foreign_Hook /= null then
+      if Is_Foreign and then Foreign_Hook /= null then
          Foreign_Hook.all (Spec, Foreign, Info.Ortho_Func);
       end if;
 
@@ -853,15 +865,21 @@ package body Trans.Chap2 is
             pragma Assert (Src.C = null);
             pragma Assert (Src.Type_Transient_Chain = Null_Iir);
          when Kind_Object =>
-            pragma Assert (Src.Object_Driver = Null_Var);
-            pragma Assert (Src.Object_Function = O_Dnode_Null);
             Dest.all :=
               (Kind => Kind_Object,
                Object_Static => Src.Object_Static,
                Object_Var => Instantiate_Var (Src.Object_Var),
-               Object_Driver => Null_Var,
-               Object_Rti => Src.Object_Rti,
-               Object_Function => O_Dnode_Null);
+               Object_Rti => Src.Object_Rti);
+         when Kind_Signal =>
+            pragma Assert (Src.Signal_Driver = Null_Var);
+            pragma Assert (Src.Signal_Function = O_Dnode_Null);
+            Dest.all :=
+              (Kind => Kind_Signal,
+               Signal_Value => Instantiate_Var (Src.Signal_Value),
+               Signal_Sig => Instantiate_Var (Src.Signal_Sig),
+               Signal_Driver => Null_Var,
+               Signal_Rti => Src.Signal_Rti,
+               Signal_Function => O_Dnode_Null);
          when Kind_Subprg =>
             Dest.Subprg_Frame_Scope :=
               Instantiate_Var_Scope (Src.Subprg_Frame_Scope);
diff --git a/src/vhdl/translate/trans-chap3.adb b/src/vhdl/translate/trans-chap3.adb
index bc82209..3ecec89 100644
--- a/src/vhdl/translate/trans-chap3.adb
+++ b/src/vhdl/translate/trans-chap3.adb
@@ -255,18 +255,15 @@ package body Trans.Chap3 is
 
    procedure Translate_Bool_Type (Def : Iir_Enumeration_Type_Definition)
    is
-      Info                  : Type_Info_Acc;
-      El_List               : Iir_List;
-      True_Lit, False_Lit   : Iir_Enumeration_Literal;
+      Info    : constant Type_Info_Acc := Get_Info (Def);
+      El_List : constant Iir_List := Get_Enumeration_Literal_List (Def);
+      pragma Assert (Get_Nbr_Elements (El_List) = 2);
+
+      False_Lit : constant Iir := Get_Nth_Element (El_List, 0);
+      True_Lit  : constant Iir := Get_Nth_Element (El_List, 1);
+
       False_Node, True_Node : O_Cnode;
    begin
-      Info := Get_Info (Def);
-      El_List := Get_Enumeration_Literal_List (Def);
-      if Get_Nbr_Elements (El_List) /= 2 then
-         raise Internal_Error;
-      end if;
-      False_Lit := Get_Nth_Element (El_List, 0);
-      True_Lit := Get_Nth_Element (El_List, 1);
       New_Boolean_Type
         (Info.Ortho_Type (Mode_Value),
          Translate_Enumeration_Literal (False_Lit), False_Node,
@@ -513,54 +510,18 @@ package body Trans.Chap3 is
    begin
       Start_Record_Type (Constr);
       New_Record_Field
-        (Constr, Info.T.Base_Field (Kind), Get_Identifier ("BASE"),
+        (Constr, Info.T.Base_Field (Kind), Wki_Base,
          Info.T.Base_Ptr_Type (Kind));
       New_Record_Field
-        (Constr, Info.T.Bounds_Field (Kind), Get_Identifier ("BOUNDS"),
+        (Constr, Info.T.Bounds_Field (Kind), Wki_Bounds,
          Info.T.Bounds_Ptr_Type);
       Finish_Record_Type (Constr, Info.Ortho_Type (Kind));
    end Create_Array_Fat_Pointer;
 
-   procedure Translate_Incomplete_Array_Type
-     (Def : Iir_Array_Type_Definition)
-   is
-      Arr_Info : Incomplete_Type_Info_Acc;
-      Info     : Type_Info_Acc;
-   begin
-      Arr_Info := Get_Info (Def);
-      if Arr_Info.Incomplete_Array /= null then
-         --  This (incomplete) array type was already translated.
-         --  This is the case for a second access type definition to this
-         --   still incomplete array type.
-         return;
-      end if;
-      Info := new Ortho_Info_Type (Kind_Type);
-      Info.Type_Mode := Type_Mode_Fat_Array;
-      Info.Type_Incomplete := True;
-      Arr_Info.Incomplete_Array := Info;
-
-      Info.T := Ortho_Info_Type_Array_Init;
-      Info.T.Bounds_Type := O_Tnode_Null;
-
-      Info.T.Bounds_Ptr_Type := New_Access_Type (Info.T.Bounds_Type);
-      New_Type_Decl (Create_Identifier ("BOUNDP"),
-                     Info.T.Bounds_Ptr_Type);
-
-      Info.T.Base_Ptr_Type (Mode_Value) := New_Access_Type (O_Tnode_Null);
-      New_Type_Decl (Create_Identifier ("BASEP"),
-                     Info.T.Base_Ptr_Type (Mode_Value));
-
-      Create_Array_Fat_Pointer (Info, Mode_Value);
-
-      New_Type_Decl
-        (Create_Identifier, Info.Ortho_Type (Mode_Value));
-   end Translate_Incomplete_Array_Type;
-
    --  Declare the bounds types for DEF.
    procedure Translate_Array_Type_Bounds
      (Def      : Iir_Array_Type_Definition;
-      Info     : Type_Info_Acc;
-      Complete : Boolean)
+      Info     : Type_Info_Acc)
    is
       Indexes_List    : constant Iir_List :=
         Get_Index_Subtype_Definition_List (Def);
@@ -602,25 +563,20 @@ package body Trans.Chap3 is
       Finish_Record_Type (Constr, Info.T.Bounds_Type);
       New_Type_Decl (Create_Identifier ("BOUND"),
                      Info.T.Bounds_Type);
-      if Complete then
-         Finish_Access_Type (Info.T.Bounds_Ptr_Type, Info.T.Bounds_Type);
-      else
-         Info.T.Bounds_Ptr_Type := New_Access_Type (Info.T.Bounds_Type);
-         New_Type_Decl (Create_Identifier ("BOUNDP"),
-                        Info.T.Bounds_Ptr_Type);
-      end if;
+      Info.T.Bounds_Ptr_Type := New_Access_Type (Info.T.Bounds_Type);
+      New_Type_Decl (Create_Identifier ("BOUNDP"),
+                     Info.T.Bounds_Ptr_Type);
    end Translate_Array_Type_Bounds;
 
    procedure Translate_Array_Type_Base
      (Def      : Iir_Array_Type_Definition;
-      Info     : Type_Info_Acc;
-      Complete : Boolean)
+      Info     : Type_Info_Acc)
    is
-      El_Type   : Iir;
+      El_Type   : constant Iir := Get_Element_Subtype (Def);
       El_Tinfo  : Type_Info_Acc;
       Id, Idptr : O_Ident;
    begin
-      El_Type := Get_Element_Subtype (Def);
+      --  Be sure the element type is translated.
       Translate_Type_Definition (El_Type, True);
       El_Tinfo := Get_Info (El_Type);
 
@@ -637,12 +593,8 @@ package body Trans.Chap3 is
             case Kind is
                when Mode_Value =>
                   --  For the values.
-                  Id := Create_Identifier ("BASE");
-                  if not Complete then
-                     Idptr := Create_Identifier ("BASEP");
-                  else
-                     Idptr := O_Ident_Nul;
-                  end if;
+                  Id := Wki_Base;
+                  Idptr := Create_Identifier ("BASEP");
                when Mode_Signal =>
                   --  For the signals
                   Id := Create_Identifier ("SIGBASE");
@@ -652,14 +604,9 @@ package body Trans.Chap3 is
               New_Array_Type (El_Tinfo.Ortho_Type (Kind),
                               Ghdl_Index_Type);
             New_Type_Decl (Id, Info.T.Base_Type (Kind));
-            if Is_Equal (Idptr, O_Ident_Nul) then
-               Finish_Access_Type (Info.T.Base_Ptr_Type (Kind),
-                                   Info.T.Base_Type (Kind));
-            else
-               Info.T.Base_Ptr_Type (Kind) :=
-                 New_Access_Type (Info.T.Base_Type (Kind));
-               New_Type_Decl (Idptr, Info.T.Base_Ptr_Type (Kind));
-            end if;
+            Info.T.Base_Ptr_Type (Kind) :=
+              New_Access_Type (Info.T.Base_Type (Kind));
+            New_Type_Decl (Idptr, Info.T.Base_Ptr_Type (Kind));
          end loop;
       end if;
    end Translate_Array_Type_Base;
@@ -668,25 +615,18 @@ package body Trans.Chap3 is
      (Def : Iir_Array_Type_Definition)
    is
       Info       : constant Type_Info_Acc := Get_Info (Def);
-      --  If true, INFO was already partially filled, by a previous access
-      --  type definition to this incomplete array type.
-      Completion : constant Boolean := Info.Type_Mode = Type_Mode_Fat_Array;
       El_Tinfo   : Type_Info_Acc;
    begin
-      if not Completion then
-         Info.Type_Mode := Type_Mode_Fat_Array;
-         Info.T := Ortho_Info_Type_Array_Init;
-      end if;
-      Translate_Array_Type_Base (Def, Info, Completion);
-      Translate_Array_Type_Bounds (Def, Info, Completion);
+      Info.Type_Mode := Type_Mode_Fat_Array;
+      Info.T := Ortho_Info_Type_Array_Init;
+      Translate_Array_Type_Base (Def, Info);
+      Translate_Array_Type_Bounds (Def, Info);
       Info.Ortho_Type (Mode_Signal) := O_Tnode_Null;
-      if not Completion then
-         Create_Array_Fat_Pointer (Info, Mode_Value);
-      end if;
+      Create_Array_Fat_Pointer (Info, Mode_Value);
       if Get_Has_Signal_Flag (Def) then
          Create_Array_Fat_Pointer (Info, Mode_Signal);
       end if;
-      Finish_Type_Definition (Info, Completion);
+      Finish_Type_Definition (Info, False);
 
       El_Tinfo := Get_Info (Get_Element_Subtype (Def));
       if Is_Complex_Type (El_Tinfo) then
@@ -1017,9 +957,7 @@ package body Trans.Chap3 is
    function Get_Type_Alignmask (Info : Type_Info_Acc) return O_Enode is
    begin
       if Is_Complex_Type (Info) then
-         if Info.Type_Mode /= Type_Mode_Record then
-            raise Internal_Error;
-         end if;
+         pragma Assert (Info.Type_Mode = Type_Mode_Record);
          return New_Value (Get_Var (Info.C (Mode_Value).Align_Var));
       else
          return Get_Type_Alignmask (Info.Ortho_Type (Mode_Value));
@@ -1222,56 +1160,56 @@ package body Trans.Chap3 is
    --  Access  --
    --------------
 
+   --  Get the ortho designated type for access type DEF.
+   function Get_Ortho_Designated_Type (Def : Iir_Access_Type_Definition)
+                                      return O_Tnode
+   is
+      D_Type   : constant Iir := Get_Designated_Type (Def);
+      D_Info   : constant Type_Info_Acc := Get_Info (D_Type);
+   begin
+      if not Is_Fully_Constrained_Type (D_Type) then
+         return D_Info.T.Bounds_Type;
+      else
+         if D_Info.Type_Mode in Type_Mode_Arrays then
+            --  The designated type cannot be a sub array inside ortho.
+            --  FIXME: lift this restriction.
+            return D_Info.T.Base_Type (Mode_Value);
+         else
+            return D_Info.Ortho_Type (Mode_Value);
+         end if;
+      end if;
+   end Get_Ortho_Designated_Type;
+
    procedure Translate_Access_Type (Def : Iir_Access_Type_Definition)
    is
       D_Type   : constant Iir := Get_Designated_Type (Def);
+      --  Info for designated type may not be a type info: it may be an
+      --  incomplete type.
       D_Info   : constant Ortho_Info_Acc := Get_Info (D_Type);
       Def_Info : constant Type_Info_Acc := Get_Info (Def);
       Dtype    : O_Tnode;
-      Arr_Info : Type_Info_Acc;
    begin
+      --  No access types for signals.
+      Def_Info.Ortho_Type (Mode_Signal) := O_Tnode_Null;
+
       if not Is_Fully_Constrained_Type (D_Type) then
-         --  An access type to an unconstrained type definition is a fat
-         --  pointer.
-         Def_Info.Type_Mode := Type_Mode_Fat_Acc;
-         if D_Info.Kind = Kind_Incomplete_Type then
-            Translate_Incomplete_Array_Type (D_Type);
-            Arr_Info := D_Info.Incomplete_Array;
-            Def_Info.Ortho_Type := Arr_Info.Ortho_Type;
-            Def_Info.T := Arr_Info.T;
-         else
-            Def_Info.Ortho_Type := D_Info.Ortho_Type;
-            Def_Info.T := D_Info.T;
-         end if;
-         Def_Info.Ortho_Ptr_Type (Mode_Value) :=
-           New_Access_Type (Def_Info.Ortho_Type (Mode_Value));
-         New_Type_Decl (Create_Identifier ("PTR"),
-                        Def_Info.Ortho_Ptr_Type (Mode_Value));
+         --  An access type to an unconstrained type definition is a pointer
+         --  to bounds and base.
+         Def_Info.Type_Mode := Type_Mode_Bounds_Acc;
       else
          --  Otherwise, it is a thin pointer.
          Def_Info.Type_Mode := Type_Mode_Acc;
-         --  No access types for signals.
-         Def_Info.Ortho_Type (Mode_Signal) := O_Tnode_Null;
-
-         if D_Info.Kind = Kind_Incomplete_Type then
-            Dtype := O_Tnode_Null;
-         elsif Is_Complex_Type (D_Info) then
-            --  FIXME: clean here when the ortho_type of a array
-            --  complex_type is correctly set (not a pointer).
-            Def_Info.Ortho_Type (Mode_Value) :=
-              D_Info.Ortho_Ptr_Type (Mode_Value);
-            Finish_Type_Definition (Def_Info, True);
-            return;
-         elsif D_Info.Type_Mode in Type_Mode_Arrays then
-            --  The designated type cannot be a sub array inside ortho.
-            --  FIXME: lift this restriction.
-            Dtype := D_Info.T.Base_Type (Mode_Value);
-         else
-            Dtype := D_Info.Ortho_Type (Mode_Value);
-         end if;
-         Def_Info.Ortho_Type (Mode_Value) := New_Access_Type (Dtype);
-         Finish_Type_Definition (Def_Info);
       end if;
+
+      if D_Info.Kind = Kind_Incomplete_Type then
+         --  Incomplete access.
+         Dtype := O_Tnode_Null;
+      else
+         Dtype := Get_Ortho_Designated_Type (Def);
+      end if;
+
+      Def_Info.Ortho_Type (Mode_Value) := New_Access_Type (Dtype);
+      Finish_Type_Definition (Def_Info);
    end Translate_Access_Type;
 
    ------------------------
@@ -1294,20 +1232,16 @@ package body Trans.Chap3 is
       Ctype := Get_Type (Get_Type_Declarator (Def));
       Info := Add_Info (Ctype, Kind_Incomplete_Type);
       Info.Incomplete_Type := Def;
-      Info.Incomplete_Array := null;
    end Translate_Incomplete_Type;
 
-   --  CTYPE is the type which has been completed.
    procedure Translate_Complete_Type
-     (Incomplete_Info : in out Incomplete_Type_Info_Acc; Ctype : Iir)
+     (Incomplete_Info : in out Incomplete_Type_Info_Acc)
    is
-      C_Info   : constant Type_Info_Acc := Get_Info (Ctype);
-      List     : Iir_List;
+      List     : constant Iir_List :=
+        Get_Incomplete_Type_List (Incomplete_Info.Incomplete_Type);
       Atype    : Iir;
       Def_Info : Type_Info_Acc;
-      Dtype    : O_Tnode;
    begin
-      List := Get_Incomplete_Type_List (Incomplete_Info.Incomplete_Type);
       for I in Natural loop
          Atype := Get_Nth_Element (List, I);
          exit when Atype = Null_Iir;
@@ -1316,13 +1250,9 @@ package body Trans.Chap3 is
          pragma Assert (Get_Kind (Atype) = Iir_Kind_Access_Type_Definition);
 
          Def_Info := Get_Info (Atype);
-         case C_Info.Type_Mode is
-            when Type_Mode_Arrays =>
-               Dtype := C_Info.T.Base_Type (Mode_Value);
-            when others =>
-               Dtype := C_Info.Ortho_Type (Mode_Value);
-         end case;
-         Finish_Access_Type (Def_Info.Ortho_Type (Mode_Value), Dtype);
+         Finish_Access_Type
+           (Def_Info.Ortho_Type (Mode_Value),
+            Get_Ortho_Designated_Type (Atype));
       end loop;
       Unchecked_Deallocation (Incomplete_Info);
    end Translate_Complete_Type;
@@ -1995,24 +1925,18 @@ package body Trans.Chap3 is
       --  If the definition is already translated, return now.
       Info := Get_Info (Def);
       if Info /= null then
-         if Info.Kind = Kind_Type then
-            --  The subtype was already translated.
-            return;
-         end if;
-         if Info.Kind = Kind_Incomplete_Type then
-            --  Type is being completed.
-            Complete_Info := Info;
-            Clear_Info (Def);
-            if Complete_Info.Incomplete_Array /= null then
-               Info := Complete_Info.Incomplete_Array;
-               Set_Info (Def, Info);
-               Unchecked_Deallocation (Complete_Info);
-            else
+         case Info.Kind is
+            when Kind_Type =>
+               --  The subtype was already translated.
+               return;
+            when Kind_Incomplete_Type =>
+               --  Type is being completed.
+               Complete_Info := Info;
+               Clear_Info (Def);
                Info := Add_Info (Def, Kind_Type);
-            end if;
-         else
-            raise Internal_Error;
-         end if;
+            when others =>
+               raise Internal_Error;
+         end case;
       else
          Complete_Info := null;
          Info := Add_Info (Def, Kind_Type);
@@ -2129,25 +2053,23 @@ package body Trans.Chap3 is
       end case;
 
       if Complete_Info /= null then
-         Translate_Complete_Type (Complete_Info, Def);
+         Translate_Complete_Type (Complete_Info);
       end if;
    end Translate_Type_Definition;
 
    procedure Translate_Bool_Type_Definition (Def : Iir)
    is
       Info : Type_Info_Acc;
+      pragma Unreferenced (Info);
    begin
-      --  If the definition is already translated, return now.
-      Info := Get_Info (Def);
-      if Info /= null then
-         raise Internal_Error;
-      end if;
+      --  Not already translated.
+      pragma Assert (Get_Info (Def) = null);
+
+      --  A boolean type is an enumerated type.
+      pragma Assert (Get_Kind (Def) = Iir_Kind_Enumeration_Type_Definition);
 
       Info := Add_Info (Def, Kind_Type);
 
-      if Get_Kind (Def) /= Iir_Kind_Enumeration_Type_Definition then
-         raise Internal_Error;
-      end if;
       Translate_Bool_Type (Def);
 
       --  This is usually done in translate_type_definition, but boolean
@@ -2168,10 +2090,9 @@ package body Trans.Chap3 is
          --  been declared by the same type declarator.  This avoids several
          --  elaboration of the same type.
          Def := Get_Base_Type (Def);
-         if Get_Type_Declarator (Def) /= Decl then
-            --  Can this happen ??
-            raise Internal_Error;
-         end if;
+
+         --  Consistency check.
+         pragma Assert (Get_Type_Declarator (Def) = Decl);
       elsif Get_Kind (Def) = Iir_Kind_Incomplete_Type_Definition then
          return;
       end if;
@@ -2232,9 +2153,9 @@ package body Trans.Chap3 is
                Final : Boolean;
             begin
                Chap4.Elab_Declaration_Chain (Def, Final);
-               if Final then
-                  raise Internal_Error;
-               end if;
+
+               --  No finalizer in protected types (only subprograms).
+               pragma Assert (Final = False);
             end;
             return;
          when others =>
@@ -2425,15 +2346,13 @@ package body Trans.Chap3 is
       Info : constant Type_Info_Acc := Get_Type_Info (Arr);
    begin
       case Info.Type_Mode is
-         when Type_Mode_Fat_Array
-            | Type_Mode_Fat_Acc =>
+         when Type_Mode_Fat_Array =>
             declare
-               Kind : Object_Kind_Type;
+               Kind : constant Object_Kind_Type := Get_Object_Kind (Arr);
             begin
-               Kind := Get_Object_Kind (Arr);
                return Lp2M
                  (New_Selected_Element (M2Lv (Arr),
-                  Info.T.Bounds_Field (Kind)),
+                                        Info.T.Bounds_Field (Kind)),
                   Info,
                   Mode_Value,
                   Info.T.Bounds_Type,
@@ -2441,6 +2360,8 @@ package body Trans.Chap3 is
             end;
          when Type_Mode_Array =>
             return Get_Array_Type_Bounds (Info);
+         when Type_Mode_Bounds_Acc =>
+            return Lp2M (M2Lv (Arr), Info, Mode_Value);
          when others =>
             raise Internal_Error;
       end case;
@@ -2508,21 +2429,18 @@ package body Trans.Chap3 is
 
    function Get_Array_Base (Arr : Mnode) return Mnode
    is
-      Info : Type_Info_Acc;
+      Info : constant Type_Info_Acc := Get_Type_Info (Arr);
    begin
-      Info := Get_Type_Info (Arr);
       case Info.Type_Mode is
-         when Type_Mode_Fat_Array
-            | Type_Mode_Fat_Acc =>
+         when Type_Mode_Fat_Array =>
             declare
-               Kind : Object_Kind_Type;
+               Kind : constant Object_Kind_Type := Get_Object_Kind (Arr);
             begin
-               Kind := Get_Object_Kind (Arr);
                return Lp2M
                  (New_Selected_Element (M2Lv (Arr),
-                  Info.T.Base_Field (Kind)),
+                                        Info.T.Base_Field (Kind)),
                   Info,
-                  Get_Object_Kind (Arr),
+                  Kind,
                   Info.T.Base_Type (Kind),
                   Info.T.Base_Ptr_Type (Kind));
             end;
@@ -2533,6 +2451,17 @@ package body Trans.Chap3 is
       end case;
    end Get_Array_Base;
 
+   function Get_Bounds_Acc_Base
+     (Acc : O_Enode; D_Type : Iir) return O_Enode
+   is
+      D_Info : constant Type_Info_Acc := Get_Info (D_Type);
+   begin
+      return Add_Pointer
+        (Acc,
+         New_Lit (New_Sizeof (D_Info.T.Bounds_Type, Ghdl_Index_Type)),
+         D_Info.T.Base_Ptr_Type (Mode_Value));
+   end Get_Bounds_Acc_Base;
+
    function Reindex_Complex_Array
      (Base : Mnode; Atype : Iir; Index : O_Enode; Res_Info : Type_Info_Acc)
       return Mnode
@@ -2542,19 +2471,14 @@ package body Trans.Chap3 is
       Kind     : constant Object_Kind_Type := Get_Object_Kind (Base);
    begin
       pragma Assert (Is_Complex_Type (El_Tinfo));
-      return
-        E2M
-          (New_Unchecked_Address
-             (New_Slice
-                (New_Access_Element
-                     (New_Convert_Ov (M2E (Base), Char_Ptr_Type)),
-                 Chararray_Type,
-                 New_Dyadic_Op (ON_Mul_Ov,
-                   New_Value
-                     (Get_Var (El_Tinfo.C (Kind).Size_Var)),
-                   Index)),
-              El_Tinfo.Ortho_Ptr_Type (Kind)),
-           Res_Info, Kind);
+      return E2M
+        (Add_Pointer
+           (M2E (Base),
+            New_Dyadic_Op (ON_Mul_Ov,
+                           New_Value (Get_Var (El_Tinfo.C (Kind).Size_Var)),
+                           Index),
+            El_Tinfo.Ortho_Ptr_Type (Kind)),
+         Res_Info, Kind);
    end Reindex_Complex_Array;
 
    function Index_Base (Base : Mnode; Atype : Iir; Index : O_Enode)
@@ -2592,6 +2516,22 @@ package body Trans.Chap3 is
       end if;
    end Slice_Base;
 
+   procedure Maybe_Call_Type_Builder (Obj : Mnode; Obj_Type : Iir)
+   is
+      Dinfo  : constant Type_Info_Acc :=
+        Get_Info (Get_Base_Type (Obj_Type));
+      Kind   : constant Object_Kind_Type := Get_Object_Kind (Obj);
+   begin
+      if Is_Complex_Type (Dinfo)
+        and then Dinfo.C (Kind).Builder_Need_Func
+      then
+         Open_Temp;
+         --  Build the type.
+         Chap3.Gen_Call_Type_Builder (Obj, Obj_Type);
+         Close_Temp;
+      end if;
+   end Maybe_Call_Type_Builder;
+
    procedure Allocate_Fat_Array_Base (Alloc_Kind : Allocation_Kind;
                                       Res        : Mnode;
                                       Arr_Type   : Iir)
@@ -2608,14 +2548,7 @@ package body Trans.Chap3 is
         (M2Lp (Chap3.Get_Array_Base (Res)),
          Gen_Alloc (Alloc_Kind, Length, Dinfo.T.Base_Ptr_Type (Kind)));
 
-      if Is_Complex_Type (Dinfo)
-        and then Dinfo.C (Kind).Builder_Need_Func
-      then
-         Open_Temp;
-         --  Build the type.
-         Chap3.Gen_Call_Type_Builder (Res, Arr_Type);
-         Close_Temp;
-      end if;
+      Maybe_Call_Type_Builder (Res, Arr_Type);
    end Allocate_Fat_Array_Base;
 
    procedure Create_Array_Subtype (Sub_Type : Iir; Transient : Boolean)
@@ -2648,14 +2581,11 @@ package body Trans.Chap3 is
    begin
       case Info.Type_Mode is
          when Type_Mode_Scalar
-            | Type_Mode_Acc
+           | Type_Mode_Acc
+           | Type_Mode_Bounds_Acc
             | Type_Mode_File =>
             --  Scalar or thin pointer.
             New_Assign_Stmt (M2Lv (Dest), Src);
-         when Type_Mode_Fat_Acc =>
-            --  a fat pointer.
-            D := Stabilize (Dest);
-            Copy_Fat_Pointer (D, Stabilize (E2M (Src, Info, Kind)));
          when Type_Mode_Fat_Array =>
             --  a fat array.
             D := Stabilize (Dest);
@@ -2672,17 +2602,19 @@ package body Trans.Chap3 is
       end case;
    end Translate_Object_Copy;
 
-   function Get_Object_Size (Obj : Mnode; Obj_Type : Iir)
-                             return O_Enode
+   function Get_Subtype_Size
+     (Atype : Iir; Bounds : Mnode; Kind : Object_Kind_Type) return O_Enode
    is
-      Type_Info : constant Type_Info_Acc := Get_Type_Info (Obj);
-      Kind      : constant Object_Kind_Type := Get_Object_Kind (Obj);
+      Type_Info : constant Type_Info_Acc := Get_Info (Atype);
    begin
+      --  The length is pre-computed for a complex type (except for unbounded
+      --  types).
       if Is_Complex_Type (Type_Info)
         and then Type_Info.C (Kind).Size_Var /= Null_Var
       then
          return New_Value (Get_Var (Type_Info.C (Kind).Size_Var));
       end if;
+
       case Type_Info.Type_Mode is
          when Type_Mode_Non_Composite
             | Type_Mode_Array
@@ -2691,29 +2623,30 @@ package body Trans.Chap3 is
                             Ghdl_Index_Type));
          when Type_Mode_Fat_Array =>
             declare
-               El_Type  : Iir;
-               El_Tinfo : Type_Info_Acc;
-               Obj_Bt   : Iir;
-               Sz       : O_Enode;
+               El_Type  : constant Iir := Get_Element_Subtype (Atype);
+               El_Sz    : O_Enode;
             begin
-               Obj_Bt := Get_Base_Type (Obj_Type);
-               El_Type := Get_Element_Subtype (Obj_Bt);
-               El_Tinfo := Get_Info (El_Type);
-               --  See create_type_definition_size_var.
-               Sz := Get_Object_Size (T2M (El_Type, Kind), El_Type);
-               if Is_Complex_Type (El_Tinfo) then
-                  Sz := New_Dyadic_Op
-                    (ON_Add_Ov,
-                     Sz,
-                     New_Lit (New_Sizeof (El_Tinfo.Ortho_Ptr_Type (Kind),
-                       Ghdl_Index_Type)));
-               end if;
+               --  See create_array_size_var.
+               El_Sz := Get_Subtype_Size (El_Type, Mnode_Null, Kind);
                return New_Dyadic_Op
-                 (ON_Mul_Ov, Chap3.Get_Array_Length (Obj, Obj_Bt), Sz);
+                 (ON_Mul_Ov, Chap3.Get_Bounds_Length (Bounds, Atype), El_Sz);
             end;
          when others =>
             raise Internal_Error;
       end case;
+   end Get_Subtype_Size;
+
+   function Get_Object_Size (Obj : Mnode; Obj_Type : Iir)
+                            return O_Enode
+   is
+      Type_Info : constant Type_Info_Acc := Get_Type_Info (Obj);
+      Kind      : constant Object_Kind_Type := Get_Object_Kind (Obj);
+   begin
+      if Type_Info.Type_Mode = Type_Mode_Fat_Array then
+         return Get_Subtype_Size (Obj_Type, Get_Array_Bounds (Obj), Kind);
+      else
+         return Get_Subtype_Size (Obj_Type, Mnode_Null, Kind);
+      end if;
    end Get_Object_Size;
 
    procedure Translate_Object_Allocation
@@ -2730,9 +2663,9 @@ package body Trans.Chap3 is
          New_Assign_Stmt
            (M2Lp (Chap3.Get_Array_Bounds (Res)),
             Gen_Alloc (Alloc_Kind,
-              New_Lit (New_Sizeof (Dinfo.T.Bounds_Type,
-                Ghdl_Index_Type)),
-              Dinfo.T.Bounds_Ptr_Type));
+                       New_Lit (New_Sizeof (Dinfo.T.Bounds_Type,
+                                            Ghdl_Index_Type)),
+                       Dinfo.T.Bounds_Ptr_Type));
 
          --  Copy bounds to the allocated area.
          Gen_Memcpy
@@ -2746,19 +2679,10 @@ package body Trans.Chap3 is
          New_Assign_Stmt
            (M2Lp (Res),
             Gen_Alloc (Alloc_Kind,
-                       Chap3.Get_Object_Size (T2M (Obj_Type, Kind),
-                                              Obj_Type),
+                       Chap3.Get_Object_Size (T2M (Obj_Type, Kind), Obj_Type),
                        Dinfo.Ortho_Ptr_Type (Kind)));
 
-         if Is_Complex_Type (Dinfo)
-           and then Dinfo.C (Kind).Builder_Need_Func
-         then
-            Open_Temp;
-            --  Build the type.
-            Chap3.Gen_Call_Type_Builder (Res, Obj_Type);
-            Close_Temp;
-         end if;
-
+         Maybe_Call_Type_Builder (Res, Obj_Type);
       end if;
    end Translate_Object_Allocation;
 
@@ -2774,59 +2698,21 @@ package body Trans.Chap3 is
    --  Performs deallocation of PARAM (the parameter of a deallocate call).
    procedure Translate_Object_Deallocation (Param : Iir)
    is
-      --  Performs deallocation of field FIELD of type FTYPE of PTR.
-      --  If FIELD is O_FNODE_NULL, deallocate PTR (of type FTYPE).
-      --  Here, deallocate means freeing memory and clearing to null.
-      procedure Deallocate_1
-        (Ptr : Mnode; Field : O_Fnode; Ftype : O_Tnode)
-      is
-         L : O_Lnode;
-      begin
-         for I in 0 .. 1 loop
-            L := M2Lv (Ptr);
-            if Field /= O_Fnode_Null then
-               L := New_Selected_Element (L, Field);
-            end if;
-            case I is
-               when 0 =>
-                  --  Call deallocator.
-                  Gen_Deallocate (New_Value (L));
-               when 1 =>
-                  --  set the value to 0.
-                  New_Assign_Stmt (L, New_Lit (New_Null_Access (Ftype)));
-            end case;
-         end loop;
-      end Deallocate_1;
-
-      Param_Type : Iir;
+      Param_Type : constant Iir := Get_Type (Param);
+      Info       : constant Type_Info_Acc := Get_Info (Param_Type);
       Val        : Mnode;
-      Info       : Type_Info_Acc;
-      Binfo      : Type_Info_Acc;
    begin
       --  Compute parameter
       Val := Chap6.Translate_Name (Param);
-      if Get_Object_Kind (Val) = Mode_Signal then
-         raise Internal_Error;
-      end if;
+      pragma Assert (Get_Object_Kind (Val) = Mode_Value);
       Stabilize (Val);
-      Param_Type := Get_Type (Param);
-      Info := Get_Info (Param_Type);
-      case Info.Type_Mode is
-         when Type_Mode_Fat_Acc =>
-            --  This is a fat pointer.
-            --  Deallocate base and bounds.
-            Binfo := Get_Info (Get_Designated_Type (Param_Type));
-            Deallocate_1 (Val, Binfo.T.Base_Field (Mode_Value),
-                          Binfo.T.Base_Ptr_Type (Mode_Value));
-            Deallocate_1 (Val, Binfo.T.Bounds_Field (Mode_Value),
-                          Binfo.T.Bounds_Ptr_Type);
-         when Type_Mode_Acc =>
-            --  This is a thin pointer.
-            Deallocate_1 (Val, O_Fnode_Null,
-                          Info.Ortho_Type (Mode_Value));
-         when others =>
-            raise Internal_Error;
-      end case;
+
+      --  Call deallocator.
+      Gen_Deallocate (New_Value (M2Lv (Val)));
+
+      --  Set the value to null.
+      New_Assign_Stmt
+        (M2Lv (Val), New_Lit (New_Null_Access (Info.Ortho_Type (Mode_Value))));
    end Translate_Object_Deallocation;
 
    function Not_In_Range (Value : O_Dnode; Atype : Iir) return O_Enode
diff --git a/src/vhdl/translate/trans-chap3.ads b/src/vhdl/translate/trans-chap3.ads
index b5f42e8..69d1137 100644
--- a/src/vhdl/translate/trans-chap3.ads
+++ b/src/vhdl/translate/trans-chap3.ads
@@ -172,6 +172,10 @@ package Trans.Chap3 is
    --  Get array bounds for type ATYPE.
    function Get_Array_Type_Bounds (Atype : Iir) return Mnode;
 
+   --  Return a pointer to the base from bounds_acc ACC.
+   function Get_Bounds_Acc_Base
+     (Acc : O_Enode; D_Type : Iir) return O_Enode;
+
    --  Deallocate OBJ.
    procedure Gen_Deallocate (Obj : O_Enode);
 
@@ -188,17 +192,25 @@ package Trans.Chap3 is
       Obj_Type   : Iir;
       Bounds     : Mnode);
 
-   --  Copy SRC to DEST.
-   --  Both have the same type, OTYPE.
-   --  Furthermore, arrays are of the same length.
+   --  Low level copy of SRC to DEST.  Both have the same type, OBJ_TYPE.
+   --  There is no length check, so arrays must be of the same length.
    procedure Translate_Object_Copy
      (Dest : Mnode; Src : O_Enode; Obj_Type : Iir);
 
+   --  Get size (in bytes with type ghdl_index_type) of subtype ATYPE.
+   --  For an unconstrained array, BOUNDS must be set, otherwise it may be a
+   --  null_mnode.
+   function Get_Subtype_Size
+     (Atype : Iir; Bounds : Mnode; Kind : Object_Kind_Type) return O_Enode;
+
    --  Get size (in bytes with type ghdl_index_type) of object OBJ.
    --  For an unconstrained array, OBJ must be really an object, otherwise,
-   --  it may be a null_mnode, created by T2M.
+   --  it may be the result of T2M.
    function Get_Object_Size (Obj : Mnode; Obj_Type : Iir) return O_Enode;
 
+   --  If needed call the procedure to build OBJ.
+   procedure Maybe_Call_Type_Builder (Obj : Mnode; Obj_Type : Iir);
+
    --  Allocate the base of a fat array, whose length is determined from
    --  the bounds.
    --  RES_PTR is a pointer to the fat pointer (must be a variable that
diff --git a/src/vhdl/translate/trans-chap4.adb b/src/vhdl/translate/trans-chap4.adb
index d9de806..852be4f 100644
--- a/src/vhdl/translate/trans-chap4.adb
+++ b/src/vhdl/translate/trans-chap4.adb
@@ -153,10 +153,9 @@ package body Trans.Chap4 is
       Sig_Type := Get_Object_Type (Type_Info, Mode_Signal);
       pragma Assert (Sig_Type /= O_Tnode_Null);
 
-      Info := Add_Info (Decl, Kind_Object);
+      Info := Add_Info (Decl, Kind_Signal);
 
-      Info.Object_Var :=
-        Create_Var (Create_Var_Identifier (Decl), Sig_Type);
+      Info.Signal_Sig := Create_Var (Create_Var_Identifier (Decl), Sig_Type);
 
       case Get_Kind (Decl) is
          when Iir_Kind_Signal_Declaration
@@ -184,9 +183,9 @@ package body Trans.Chap4 is
       --Chap3.Translate_Object_Subtype (Decl);
       pragma Assert (Sig_Type /= O_Tnode_Null);
 
-      Info := Add_Info (Decl, Kind_Object);
+      Info := Add_Info (Decl, Kind_Signal);
 
-      Info.Object_Var := Create_Var (Create_Uniq_Identifier, Sig_Type);
+      Info.Signal_Sig := Create_Var (Create_Uniq_Identifier, Sig_Type);
    end Create_Implicit_Signal;
 
    procedure Create_File_Object (El : Iir_File_Declaration)
@@ -238,10 +237,8 @@ package body Trans.Chap4 is
       Kind      : constant Object_Kind_Type := Get_Object_Kind (Var);
       Targ      : Mnode;
    begin
-      if Type_Info.Type_Mode = Type_Mode_Fat_Array then
-         --  Cannot allocate unconstrained object (since size is unknown).
-         raise Internal_Error;
-      end if;
+      --  Cannot allocate unconstrained object (since size is unknown).
+      pragma Assert (Type_Info.Type_Mode /= Type_Mode_Fat_Array);
 
       if not Is_Complex_Type (Type_Info) then
          --  Object is not complex.
@@ -257,11 +254,10 @@ package body Trans.Chap4 is
       end if;
 
       --  Allocate variable.
-      New_Assign_Stmt
-        (M2Lp (Targ),
-         Gen_Alloc (Alloc_Kind,
-           Chap3.Get_Object_Size (Var, Obj_Type),
-           Type_Info.Ortho_Ptr_Type (Kind)));
+      New_Assign_Stmt (M2Lp (Targ),
+                       Gen_Alloc (Alloc_Kind,
+                                  Chap3.Get_Object_Size (Var, Obj_Type),
+                                  Type_Info.Ortho_Ptr_Type (Kind)));
 
       if Type_Info.C (Kind).Builder_Need_Func then
          --  Build the type.
@@ -277,10 +273,10 @@ package body Trans.Chap4 is
    --  FIXME: should use translate_aggregate_others.
    procedure Init_Array_Object (Obj : Mnode; Obj_Type : Iir)
    is
-      Sobj : Mnode;
-
       --  Type of the object.
-      Type_Info : Type_Info_Acc;
+      Type_Info : constant Type_Info_Acc := Get_Info (Obj_Type);
+
+      Sobj : Mnode;
 
       --  Iterator for the elements.
       Index : O_Dnode;
@@ -290,8 +286,6 @@ package body Trans.Chap4 is
 
       Label : O_Snode;
    begin
-      Type_Info := Get_Info (Obj_Type);
-
       --  Iterate on all elements of the object.
       Open_Temp;
 
@@ -330,11 +324,9 @@ package body Trans.Chap4 is
 
    procedure Init_Protected_Object (Obj : Mnode; Obj_Type : Iir)
    is
+      Info  : constant Type_Info_Acc := Get_Info (Obj_Type);
       Assoc : O_Assoc_List;
-      Info  : Type_Info_Acc;
    begin
-      Info := Get_Info (Obj_Type);
-
       --  Call the initializer.
       Start_Association (Assoc, Info.T.Prot_Init_Subprg);
       Subprgs.Add_Subprg_Instance_Assoc (Assoc, Info.T.Prot_Init_Instance);
@@ -345,12 +337,10 @@ package body Trans.Chap4 is
 
    procedure Fini_Protected_Object (Decl : Iir)
    is
+      Info  : constant Type_Info_Acc := Get_Info (Get_Type (Decl));
       Obj   : Mnode;
       Assoc : O_Assoc_List;
-      Info  : Type_Info_Acc;
    begin
-      Info := Get_Info (Get_Type (Decl));
-
       Obj := Chap6.Translate_Name (Decl);
       --  Call the Finalizator.
       Start_Association (Assoc, Info.T.Prot_Final_Subprg);
@@ -365,7 +355,8 @@ package body Trans.Chap4 is
       case Tinfo.Type_Mode is
          when Type_Mode_Scalar =>
             return Chap14.Translate_Left_Type_Attribute (Atype);
-         when Type_Mode_Acc =>
+         when Type_Mode_Acc
+           | Type_Mode_Bounds_Acc =>
             return New_Lit (New_Null_Access (Tinfo.Ortho_Type (Mode_Value)));
          when others =>
             Error_Kind ("get_scalar_initial_value", Atype);
@@ -378,27 +369,9 @@ package body Trans.Chap4 is
    begin
       case Tinfo.Type_Mode is
          when Type_Mode_Scalar
-           | Type_Mode_Acc =>
+           | Type_Mode_Acc
+           | Type_Mode_Bounds_Acc =>
             New_Assign_Stmt (M2Lv (Obj), Get_Scalar_Initial_Value (Obj_Type));
-         when Type_Mode_Fat_Acc =>
-            declare
-               Dinfo : Type_Info_Acc;
-               Sobj  : Mnode;
-            begin
-               Open_Temp;
-               Sobj := Stabilize (Obj);
-               Dinfo := Get_Info (Get_Designated_Type (Obj_Type));
-               New_Assign_Stmt
-                 (New_Selected_Element (M2Lv (Sobj),
-                  Dinfo.T.Bounds_Field (Mode_Value)),
-                  New_Lit (New_Null_Access (Dinfo.T.Bounds_Ptr_Type)));
-               New_Assign_Stmt
-                 (New_Selected_Element (M2Lv (Sobj),
-                  Dinfo.T.Base_Field (Mode_Value)),
-                  New_Lit (New_Null_Access
-                    (Dinfo.T.Base_Ptr_Type (Mode_Value))));
-               Close_Temp;
-            end;
          when Type_Mode_Arrays =>
             Init_Array_Object (Obj, Obj_Type);
          when Type_Mode_Record =>
@@ -587,11 +560,9 @@ package body Trans.Chap4 is
 
    procedure Fini_Object (Obj : Iir)
    is
-      Obj_Type  : Iir;
-      Type_Info : Type_Info_Acc;
+      Obj_Type  : constant Iir := Get_Type (Obj);
+      Type_Info : constant Type_Info_Acc := Get_Info (Obj_Type);
    begin
-      Obj_Type := Get_Type (Obj);
-      Type_Info := Get_Info (Obj_Type);
       if Type_Info.Type_Mode = Type_Mode_Fat_Array then
          declare
             V : Mnode;
@@ -629,11 +600,13 @@ package body Trans.Chap4 is
                Len := Create_Temp_Init
                  (Ghdl_Index_Type,
                   Chap3.Get_Array_Length (Ssig, Sig_Type));
+               --  Can dereference the first index only if the array is not a
+               --  null array.
                Start_If_Stmt (If_Blk,
                               New_Compare_Op (ON_Neq,
-                                New_Obj_Value (Len),
-                                New_Lit (Ghdl_Index_0),
-                                Ghdl_Bool_Type));
+                                              New_Obj_Value (Len),
+                                              New_Lit (Ghdl_Index_0),
+                                              Ghdl_Bool_Type));
                New_Assign_Stmt
                  (New_Obj (Len),
                   New_Dyadic_Op
@@ -650,15 +623,14 @@ package body Trans.Chap4 is
             end;
          when Type_Mode_Record =>
             declare
-               List   : Iir_List;
+               List   : constant Iir_List :=
+                 Get_Elements_Declaration_List (Get_Base_Type (Sig_Type));
                El     : Iir;
                Res    : O_Enode;
                E      : O_Enode;
                Sig_El : Mnode;
                Ssig   : Mnode;
             begin
-               List :=
-                 Get_Elements_Declaration_List (Get_Base_Type (Sig_Type));
                Ssig := Stabilize (Sig);
                Res := O_Enode_Null;
                for I in Natural loop
@@ -681,7 +653,7 @@ package body Trans.Chap4 is
          when Type_Mode_Unknown
             | Type_Mode_File
             | Type_Mode_Acc
-            | Type_Mode_Fat_Acc
+            | Type_Mode_Bounds_Acc
             | Type_Mode_Protected =>
             raise Internal_Error;
       end case;
@@ -724,7 +696,7 @@ package body Trans.Chap4 is
             when Type_Mode_Unknown
                | Type_Mode_File
                | Type_Mode_Acc
-               | Type_Mode_Fat_Acc
+               | Type_Mode_Bounds_Acc
                | Type_Mode_Protected =>
                raise Internal_Error;
          end case;
@@ -790,9 +762,9 @@ package body Trans.Chap4 is
          Start_If_Stmt
            (If_Stmt,
             New_Compare_Op (ON_Eq,
-              New_Value (New_Acc_Value (New_Obj (Targ_Ptr))),
-              New_Lit (New_Null_Access (Ghdl_Signal_Ptr)),
-              Ghdl_Bool_Type));
+                            New_Value (New_Acc_Value (New_Obj (Targ_Ptr))),
+                            New_Lit (New_Null_Access (Ghdl_Signal_Ptr)),
+                            Ghdl_Bool_Type));
       end if;
 
       case Type_Info.Type_Mode is
@@ -872,8 +844,8 @@ package body Trans.Chap4 is
                   New_Compare_Op
                     (ON_Eq,
                      New_Convert_Ov (M2E (Get_Leftest_Signal (Targ,
-                       Targ_Type)),
-                       Ghdl_Signal_Ptr),
+                                                              Targ_Type)),
+                                     Ghdl_Signal_Ptr),
                      New_Lit (New_Null_Access (Ghdl_Signal_Ptr)),
                      Ghdl_Bool_Type));
                --Res.Check_Null := False;
@@ -961,7 +933,7 @@ package body Trans.Chap4 is
    --  Elaborate signal subtypes and allocate the storage for the object.
    procedure Elab_Signal_Declaration_Storage (Decl : Iir)
    is
-      Sig_Type  : Iir;
+      Sig_Type  : constant Iir := Get_Type (Decl);
       Type_Info : Type_Info_Acc;
       Name_Node : Mnode;
    begin
@@ -969,7 +941,6 @@ package body Trans.Chap4 is
 
       Open_Temp;
 
-      Sig_Type := Get_Type (Decl);
       Chap3.Elab_Object_Subtype (Sig_Type);
       Type_Info := Get_Info (Sig_Type);
 
@@ -987,11 +958,11 @@ package body Trans.Chap4 is
 
    function Has_Direct_Driver (Sig : Iir) return Boolean
    is
-      Info : Ortho_Info_Acc;
+      Info : constant Ortho_Info_Acc := Get_Info (Get_Object_Prefix (Sig));
    begin
-      Info := Get_Info (Get_Object_Prefix (Sig));
-      return Info.Kind = Kind_Object
-        and then Info.Object_Driver /= Null_Var;
+      --  Can be an alias ?
+      return Info.Kind = Kind_Signal
+        and then Info.Signal_Driver /= Null_Var;
    end Has_Direct_Driver;
 
    procedure Elab_Direct_Driver_Declaration_Storage (Decl : Iir)
@@ -1004,8 +975,7 @@ package body Trans.Chap4 is
       Open_Temp;
 
       if Type_Info.Type_Mode = Type_Mode_Fat_Array then
-         Name_Node := Get_Var (Sig_Info.Object_Driver,
-                               Type_Info, Mode_Value);
+         Name_Node := Get_Var (Sig_Info.Signal_Driver, Type_Info, Mode_Value);
          Name_Node := Stabilize (Name_Node);
          --  Copy bounds from signal.
          New_Assign_Stmt
@@ -1014,8 +984,7 @@ package body Trans.Chap4 is
          --  Allocate base.
          Chap3.Allocate_Fat_Array_Base (Alloc_System, Name_Node, Sig_Type);
       elsif Is_Complex_Type (Type_Info) then
-         Name_Node := Get_Var (Sig_Info.Object_Driver,
-                               Type_Info, Mode_Value);
+         Name_Node := Get_Var (Sig_Info.Signal_Driver, Type_Info, Mode_Value);
          Allocate_Complex_Object (Sig_Type, Alloc_System, Name_Node);
       end if;
 
@@ -1049,16 +1018,15 @@ package body Trans.Chap4 is
          New_Association
            (Assoc,
             New_Lit (New_Global_Unchecked_Address
-              (Get_Info (Base_Decl).Object_Rti,
-                   Rtis.Ghdl_Rti_Access)));
+                       (Get_Info (Base_Decl).Signal_Rti,
+                        Rtis.Ghdl_Rti_Access)));
          Rtis.Associate_Rti_Context (Assoc, Parent);
          New_Procedure_Call (Assoc);
       end;
 
       Name_Node := Chap6.Translate_Name (Decl);
-      if Get_Object_Kind (Name_Node) /= Mode_Signal then
-         raise Internal_Error;
-      end if;
+      --  Consistency check: a signal name is a signal.
+      pragma Assert (Get_Object_Kind (Name_Node) = Mode_Signal);
 
       if Decl = Base_Decl then
          Data.Already_Resolved := False;
@@ -1095,10 +1063,10 @@ package body Trans.Chap4 is
 
    procedure Elab_Signal_Attribute (Decl : Iir)
    is
+      Info        : constant Signal_Info_Acc := Get_Info (Decl);
+      Dtype       : constant Iir := Get_Type (Decl);
+      Type_Info   : constant Type_Info_Acc := Get_Info (Dtype);
       Assoc       : O_Assoc_List;
-      Dtype       : Iir;
-      Type_Info   : Type_Info_Acc;
-      Info        : Object_Info_Acc;
       Prefix      : Iir;
       Prefix_Node : Mnode;
       Res         : O_Enode;
@@ -1108,9 +1076,6 @@ package body Trans.Chap4 is
    begin
       New_Debug_Line_Stmt (Get_Line_Number (Decl));
 
-      Info := Get_Info (Decl);
-      Dtype := Get_Type (Decl);
-      Type_Info := Get_Info (Dtype);
       --  Create the signal (with the time)
       case Get_Kind (Decl) is
          when Iir_Kind_Stable_Attribute =>
@@ -1138,7 +1103,7 @@ package body Trans.Chap4 is
       end case;
       Res := New_Convert_Ov (New_Function_Call (Assoc),
                              Type_Info.Ortho_Type (Mode_Signal));
-      New_Assign_Stmt (Get_Var (Info.Object_Var), Res);
+      New_Assign_Stmt (Get_Var (Info.Signal_Sig), Res);
 
       --  Register all signals this depends on.
       Prefix := Get_Prefix (Decl);
@@ -1238,15 +1203,13 @@ package body Trans.Chap4 is
 
    procedure Elab_Signal_Delayed_Attribute (Decl : Iir)
    is
+      Sig_Type  : constant Iir := Get_Type (Decl);
+      Type_Info : constant Type_Info_Acc := Get_Info (Sig_Type);
       Name_Node : Mnode;
-      Sig_Type  : Iir;
-      Type_Info : Type_Info_Acc;
       Pfx_Node  : Mnode;
       Data      : Delayed_Signal_Data;
    begin
       Name_Node := Chap6.Translate_Name (Decl);
-      Sig_Type := Get_Type (Decl);
-      Type_Info := Get_Info (Sig_Type);
 
       if Is_Complex_Type (Type_Info) then
          Allocate_Complex_Object (Sig_Type, Alloc_System, Name_Node);
@@ -1264,21 +1227,19 @@ package body Trans.Chap4 is
 
    procedure Elab_File_Declaration (Decl : Iir_File_Declaration)
    is
+      Is_Text   : constant Boolean := Get_Text_File_Flag (Get_Type (Decl));
+      File_Name : constant Iir := Get_File_Logical_Name (Decl);
       Constr    : O_Assoc_List;
       Name      : Mnode;
-      File_Name : Iir;
       Open_Kind : Iir;
       Mode_Val  : O_Enode;
       Str       : O_Enode;
-      Is_Text   : Boolean;
       Info      : Type_Info_Acc;
    begin
       --  Elaborate the file.
       Name := Chap6.Translate_Name (Decl);
-      if Get_Object_Kind (Name) /= Mode_Value then
-         raise Internal_Error;
-      end if;
-      Is_Text := Get_Text_File_Flag (Get_Type (Decl));
+      pragma Assert (Get_Object_Kind (Name) = Mode_Value);
+
       if Is_Text then
          Start_Association (Constr, Ghdl_Text_File_Elaborate);
       else
@@ -1296,7 +1257,6 @@ package body Trans.Chap4 is
       New_Assign_Stmt (M2Lv (Name), New_Function_Call (Constr));
 
       --  If file_open_information is present, open the file.
-      File_Name := Get_File_Logical_Name (Decl);
       if File_Name = Null_Iir then
          return;
       end if;
@@ -1304,9 +1264,11 @@ package body Trans.Chap4 is
       Name := Chap6.Translate_Name (Decl);
       Open_Kind := Get_File_Open_Kind (Decl);
       if Open_Kind /= Null_Iir then
+         --  VHDL 93 and later.
          Mode_Val := New_Convert_Ov
            (Chap7.Translate_Expression (Open_Kind), Ghdl_I32_Type);
       else
+         --  VHDL 87.
          case Get_Mode (Decl) is
             when Iir_In_Mode =>
                Mode_Val := New_Lit (New_Signed_Literal (Ghdl_I32_Type, 0));
@@ -1332,12 +1294,10 @@ package body Trans.Chap4 is
 
    procedure Final_File_Declaration (Decl : Iir_File_Declaration)
    is
+      Is_Text : constant Boolean := Get_Text_File_Flag (Get_Type (Decl));
       Constr  : O_Assoc_List;
       Name    : Mnode;
-      Is_Text : Boolean;
    begin
-      Is_Text := Get_Text_File_Flag (Get_Type (Decl));
-
       Open_Temp;
       Name := Chap6.Translate_Name (Decl);
       Stabilize (Name);
@@ -1367,8 +1327,7 @@ package body Trans.Chap4 is
       Close_Temp;
    end Final_File_Declaration;
 
-   procedure Translate_Type_Declaration (Decl : Iir)
-   is
+   procedure Translate_Type_Declaration (Decl : Iir) is
    begin
       Chap3.Translate_Named_Type_Definition (Get_Type_Definition (Decl),
                                              Get_Identifier (Decl));
@@ -1432,7 +1391,7 @@ package body Trans.Chap4 is
             Atype := Get_Ortho_Type (Decl_Type, Info.Alias_Kind);
          when Type_Mode_Array
             | Type_Mode_Acc
-            | Type_Mode_Fat_Acc =>
+            | Type_Mode_Bounds_Acc =>
             --  Create an object pointer.
             --  At elaboration: copy base from name.
             Atype := Tinfo.Ortho_Ptr_Type (Info.Alias_Kind);
@@ -1491,7 +1450,7 @@ package body Trans.Chap4 is
                                      Decl);
             Close_Temp;
          when Type_Mode_Acc
-            | Type_Mode_Fat_Acc =>
+            | Type_Mode_Bounds_Acc =>
             New_Assign_Stmt (Get_Var (Alias_Info.Alias_Var),
                              M2Addr (Name_Node));
          when Type_Mode_Scalar =>
@@ -1645,12 +1604,12 @@ package body Trans.Chap4 is
 
    procedure Translate_Resolution_Function (Func : Iir)
    is
+      Finfo           : constant Subprg_Info_Acc := Get_Info (Func);
+      Rinfo           : constant Subprg_Resolv_Info_Acc := Finfo.Subprg_Resolv;
       --  Type of the resolution function parameter.
       El_Type         : Iir;
       El_Info         : Type_Info_Acc;
-      Finfo           : constant Subprg_Info_Acc := Get_Info (Func);
       Interface_List  : O_Inter_List;
-      Rinfo           : constant Subprg_Resolv_Info_Acc := Finfo.Subprg_Resolv;
       Id              : O_Ident;
       Itype           : O_Tnode;
       Unused_Instance : O_Dnode;
@@ -1717,11 +1676,10 @@ package body Trans.Chap4 is
    procedure Read_Source_Non_Composite
      (Targ : Mnode; Targ_Type : Iir; Data : Read_Source_Data)
    is
+      Targ_Info : constant Type_Info_Acc := Get_Info (Targ_Type);
       Assoc     : O_Assoc_List;
-      Targ_Info : Type_Info_Acc;
       E         : O_Enode;
    begin
-      Targ_Info := Get_Info (Targ_Type);
       case Data.Kind is
          when Read_Port =>
             Start_Association (Assoc, Ghdl_Signal_Read_Port);
@@ -1760,8 +1718,7 @@ package body Trans.Chap4 is
 
    function Read_Source_Update_Data_Array
      (Data : Read_Source_Data; Targ_Type : Iir; Index : O_Dnode)
-         return Read_Source_Data
-   is
+     return Read_Source_Data is
    begin
       return Read_Source_Data'
         (Sig => Chap3.Index_Base (Data.Sig, Targ_Type,
@@ -1774,7 +1731,7 @@ package body Trans.Chap4 is
      (Data      : Read_Source_Data;
       Targ_Type : Iir;
       El        : Iir_Element_Declaration)
-         return Read_Source_Data
+     return Read_Source_Data
    is
       pragma Unreferenced (Targ_Type);
    begin
diff --git a/src/vhdl/translate/trans-chap5.adb b/src/vhdl/translate/trans-chap5.adb
index a58bd95..f8cfadb 100644
--- a/src/vhdl/translate/trans-chap5.adb
+++ b/src/vhdl/translate/trans-chap5.adb
@@ -17,7 +17,6 @@
 --  02111-1307, USA.
 
 with Errorout; use Errorout;
-with Sem_Names;
 with Iirs_Utils; use Iirs_Utils;
 with Trans.Chap3;
 with Trans.Chap4;
@@ -336,13 +335,12 @@ package body Trans.Chap5 is
 
    procedure Elab_Unconstrained_Port (Port : Iir; Actual : Iir)
    is
+      Actual_Type : constant Iir := Get_Type (Actual);
       Act_Node    : Mnode;
       Bounds      : Mnode;
       Tinfo       : Type_Info_Acc;
       Bound_Var   : O_Dnode;
-      Actual_Type : Iir;
    begin
-      Actual_Type := Get_Type (Actual);
       Open_Temp;
       if Is_Fully_Constrained_Type (Actual_Type) then
          Chap3.Create_Array_Subtype (Actual_Type, False);
@@ -354,13 +352,13 @@ package body Trans.Chap5 is
             New_Assign_Stmt
               (New_Obj (Bound_Var),
                Gen_Alloc (Alloc_System,
-                 New_Lit (New_Sizeof (Tinfo.T.Bounds_Type,
-                   Ghdl_Index_Type)),
-                 Tinfo.T.Bounds_Ptr_Type));
+                          New_Lit (New_Sizeof (Tinfo.T.Bounds_Type,
+                                               Ghdl_Index_Type)),
+                          Tinfo.T.Bounds_Ptr_Type));
             Gen_Memcpy (New_Obj_Value (Bound_Var),
                         M2Addr (Bounds),
                         New_Lit (New_Sizeof (Tinfo.T.Bounds_Type,
-                          Ghdl_Index_Type)));
+                                             Ghdl_Index_Type)));
             Bounds := Dp2M (Bound_Var, Tinfo, Mode_Value,
                             Tinfo.T.Bounds_Type,
                             Tinfo.T.Bounds_Ptr_Type);
@@ -378,19 +376,6 @@ package body Trans.Chap5 is
       Close_Temp;
    end Elab_Unconstrained_Port;
 
-   --  Return TRUE if EXPR is a signal name.
-   function Is_Signal (Expr : Iir) return Boolean
-   is
-      Obj : Iir;
-   begin
-      Obj := Sem_Names.Name_To_Object (Expr);
-      if Obj /= Null_Iir then
-         return Is_Signal_Object (Obj);
-      else
-         return False;
-      end if;
-   end Is_Signal;
-
    procedure Elab_Port_Map_Aspect_Assoc (Assoc : Iir; By_Copy : Boolean)
    is
       Formal      : constant Iir := Get_Formal (Assoc);
@@ -412,10 +397,8 @@ package body Trans.Chap5 is
         and then Get_Out_Conversion (Assoc) = Null_Iir
       then
          Formal_Node := Chap6.Translate_Name (Formal);
-         if Get_Object_Kind (Formal_Node) /= Mode_Signal then
-            raise Internal_Error;
-         end if;
-         if Is_Signal (Actual) then
+         pragma Assert (Get_Object_Kind (Formal_Node) = Mode_Signal);
+         if Is_Signal_Name (Actual) then
             --  LRM93 4.3.1.2
             --  For a signal of a scalar type, each source is either
             --  a driver or an OUT, INOUT, BUFFER or LINKAGE port of
diff --git a/src/vhdl/translate/trans-chap6.adb b/src/vhdl/translate/trans-chap6.adb
index 96e7b39..368b3d6 100644
--- a/src/vhdl/translate/trans-chap6.adb
+++ b/src/vhdl/translate/trans-chap6.adb
@@ -745,20 +745,21 @@ package body Trans.Chap6 is
    begin
       case Info.Kind is
          when Kind_Object =>
-            --  For a generic or a port.
+            --  For a generic.
+            pragma Assert (Kind = Mode_Value);
             return Get_Var (Info.Object_Var, Type_Info, Kind);
+         when Kind_Signal =>
+            --  For a port.
+            return Get_Var (Info.Signal_Sig, Type_Info, Kind);
          when Kind_Interface =>
             --  For a parameter.
             if Info.Interface_Field = O_Fnode_Null then
                --  Normal case: the parameter was translated as an ortho
                --  interface.
-               case Type_Info.Type_Mode is
-                  when Type_Mode_Unknown =>
-                     raise Internal_Error;
-                  when Type_Mode_By_Value =>
+               case Type_Mode_Valid (Type_Info.Type_Mode) is
+                  when Type_Mode_Pass_By_Copy =>
                      return Dv2M (Info.Interface_Node, Type_Info, Kind);
-                  when Type_Mode_By_Copy
-                     | Type_Mode_By_Ref =>
+                  when Type_Mode_Pass_By_Address =>
                      --  Parameter is passed by reference.
                      return Dp2M (Info.Interface_Node, Type_Info, Kind);
                end case;
@@ -790,14 +791,10 @@ package body Trans.Chap6 is
                        (Get_Instance_Ref (Subprg_Info.Subprg_Frame_Scope),
                         Info.Interface_Field);
                   end if;
-                  case Type_Info.Type_Mode is
-                     when Type_Mode_Unknown =>
-                        raise Internal_Error;
-                     when Type_Mode_By_Value =>
+                  case Type_Mode_Valid (Type_Info.Type_Mode) is
+                     when Type_Mode_Pass_By_Copy =>
                         return Lv2M (Linter, Type_Info, Kind);
-                     when Type_Mode_By_Copy
-                       | Type_Mode_By_Ref =>
-                        --  Parameter is passed by reference.
+                     when Type_Mode_Pass_By_Address =>
                         return Lp2M (Linter, Type_Info, Kind);
                   end case;
                end;
@@ -931,7 +928,7 @@ package body Trans.Chap6 is
                   when Type_Mode_Array
                      | Type_Mode_Record
                      | Type_Mode_Acc
-                     | Type_Mode_Fat_Acc =>
+                     | Type_Mode_Bounds_Acc =>
                      R := Get_Var (Name_Info.Alias_Var);
                      return Lp2M (R, Type_Info, Name_Info.Alias_Kind);
                   when Type_Mode_Scalar =>
@@ -952,7 +949,7 @@ package body Trans.Chap6 is
             | Iir_Kind_Delayed_Attribute
             | Iir_Kind_Transaction_Attribute
             | Iir_Kind_Guard_Signal_Declaration =>
-            return Get_Var (Name_Info.Object_Var, Type_Info, Mode_Signal);
+            return Get_Var (Name_Info.Signal_Sig, Type_Info, Mode_Signal);
 
          when Iir_Kind_Interface_Constant_Declaration =>
             return Translate_Interface_Name (Name, Name_Info, Mode_Value);
@@ -977,12 +974,25 @@ package body Trans.Chap6 is
          when Iir_Kind_Dereference
             | Iir_Kind_Implicit_Dereference =>
             declare
+               Prefix : constant Iir := Get_Prefix (Name);
+               Prefix_Type : constant Iir := Get_Type (Prefix);
+               Pt_Info : constant Type_Info_Acc := Get_Info (Prefix_Type);
                Pfx : O_Enode;
+               Pfx_Var : O_Dnode;
             begin
-               Pfx := Chap7.Translate_Expression (Get_Prefix (Name));
-               --  FIXME: what about fat pointer ??
-               return Lv2M (New_Access_Element (Pfx),
-                            Type_Info, Mode_Value);
+               Pfx := Chap7.Translate_Expression (Prefix);
+               if Pt_Info.Type_Mode = Type_Mode_Bounds_Acc then
+                  Pfx_Var := Create_Temp_Init
+                    (Pt_Info.Ortho_Type (Mode_Value), Pfx);
+                  return Chap7.Bounds_Acc_To_Fat_Pointer
+                    (Pfx_Var, Prefix_Type);
+               else
+                  return Lv2M
+                    (New_Access_Element
+                       (New_Convert_Ov
+                          (Pfx, Type_Info.Ortho_Ptr_Type (Mode_Value))),
+                     Type_Info, Mode_Value);
+               end if;
             end;
 
          when Iir_Kind_Selected_Element =>
@@ -1040,8 +1050,8 @@ package body Trans.Chap6 is
             Translate_Direct_Driver (Get_Name (Name), Sig, Drv);
          when Iir_Kind_Signal_Declaration
             | Iir_Kind_Interface_Signal_Declaration =>
-            Sig := Get_Var (Name_Info.Object_Var, Type_Info, Mode_Signal);
-            Drv := Get_Var (Name_Info.Object_Driver, Type_Info, Mode_Value);
+            Sig := Get_Var (Name_Info.Signal_Sig, Type_Info, Mode_Signal);
+            Drv := Get_Var (Name_Info.Signal_Driver, Type_Info, Mode_Value);
          when Iir_Kind_Slice_Name =>
             declare
                Data    : Slice_Name_Data;
diff --git a/src/vhdl/translate/trans-chap7.adb b/src/vhdl/translate/trans-chap7.adb
index a3ae289..0b2479d 100644
--- a/src/vhdl/translate/trans-chap7.adb
+++ b/src/vhdl/translate/trans-chap7.adb
@@ -2598,10 +2598,9 @@ package body Trans.Chap7 is
               (M2Lv (Target),
                Chap3.Maybe_Insert_Scalar_Check (Val, Expr, Target_Type));
          when Type_Mode_Acc
-            | Type_Mode_File =>
+           | Type_Mode_Bounds_Acc
+           | Type_Mode_File =>
             New_Assign_Stmt (M2Lv (Target), Val);
-         when Type_Mode_Fat_Acc =>
-            Chap3.Translate_Object_Copy (Target, Val, Target_Type);
          when Type_Mode_Fat_Array =>
             declare
                T : Mnode;
@@ -3263,74 +3262,161 @@ package body Trans.Chap7 is
 
    function Translate_Allocator_By_Expression (Expr : Iir) return O_Enode
    is
-      Val    : O_Enode;
-      Val_M  : Mnode;
       A_Type : constant Iir := Get_Type (Expr);
       A_Info : constant Type_Info_Acc := Get_Info (A_Type);
       D_Type : constant Iir := Get_Designated_Type (A_Type);
       D_Info : constant Type_Info_Acc := Get_Info (D_Type);
+      Val    : O_Enode;
       R      : Mnode;
-      Rtype  : O_Tnode;
    begin
       --  Compute the expression.
       Val := Translate_Expression (Get_Expression (Expr), D_Type);
+
       --  Allocate memory for the object.
       case A_Info.Type_Mode is
-         when Type_Mode_Fat_Acc =>
-            R := Dv2M (Create_Temp (D_Info.Ortho_Type (Mode_Value)),
-                       D_Info, Mode_Value);
-            Val_M := Stabilize (E2M (Val, D_Info, Mode_Value));
-            Chap3.Translate_Object_Allocation
-              (R, Alloc_Heap, D_Type,
-               Chap3.Get_Array_Bounds (Val_M));
-            Val := M2E (Val_M);
-            Rtype := A_Info.Ortho_Ptr_Type (Mode_Value);
+         when Type_Mode_Bounds_Acc =>
+            declare
+               Res : O_Dnode;
+               Val_Size : O_Dnode;
+               Bounds_Size : O_Cnode;
+               Val_M  : Mnode;
+            begin
+               Res := Create_Temp (A_Info.Ortho_Type (Mode_Value));
+               Val_M := Stabilize (E2M (Val, D_Info, Mode_Value));
+
+               --  Size of the value (object without the bounds).
+               Val_Size := Create_Temp_Init
+                 (Ghdl_Index_Type,
+                  Chap3.Get_Subtype_Size
+                    (D_Type, Chap3.Get_Array_Bounds (Val_M), Mode_Value));
+
+               --  Size of the bounds.
+               Bounds_Size :=
+                 New_Sizeof (D_Info.T.Bounds_Type, Ghdl_Index_Type);
+
+               --  Allocate the object.
+               New_Assign_Stmt
+                 (New_Obj (Res),
+                  Gen_Alloc (Alloc_Heap,
+                             New_Dyadic_Op
+                               (ON_Add_Ov,
+                                New_Lit (Bounds_Size),
+                                New_Obj_Value (Val_Size)),
+                             A_Info.Ortho_Type (Mode_Value)));
+
+               --  Copy bounds.
+               Gen_Memcpy
+                 (New_Obj_Value (Res), M2Addr (Chap3.Get_Array_Bounds (Val_M)),
+                  New_Lit (Bounds_Size));
+
+               --  Copy values.
+               Gen_Memcpy
+                 (Chap3.Get_Bounds_Acc_Base (New_Obj_Value (Res), D_Type),
+                  M2Addr (Chap3.Get_Array_Base (Val_M)),
+                  New_Obj_Value (Val_Size));
+
+               return New_Obj_Value (Res);
+            end;
          when Type_Mode_Acc =>
             R := Dp2M (Create_Temp (D_Info.Ortho_Ptr_Type (Mode_Value)),
                        D_Info, Mode_Value);
             Chap3.Translate_Object_Allocation
               (R, Alloc_Heap, D_Type, Mnode_Null);
-            Rtype := A_Info.Ortho_Type (Mode_Value);
+            Chap3.Translate_Object_Copy (R, Val, D_Type);
+            return New_Convert_Ov (M2Addr (R), A_Info.Ortho_Type (Mode_Value));
          when others =>
             raise Internal_Error;
       end case;
-      Chap3.Translate_Object_Copy (R, Val, D_Type);
-      return New_Convert_Ov (M2Addr (R), Rtype);
    end Translate_Allocator_By_Expression;
 
+   function Bounds_Acc_To_Fat_Pointer (Ptr : O_Dnode; Acc_Type : Iir)
+                                      return Mnode
+   is
+      D_Type   : constant Iir := Get_Designated_Type (Acc_Type);
+      D_Info   : constant Type_Info_Acc := Get_Info (D_Type);
+      Res : Mnode;
+   begin
+      Res := Dv2M (Create_Temp (D_Info.Ortho_Type (Mode_Value)),
+                   D_Info, Mode_Value);
+
+      New_Assign_Stmt
+        (M2Lp (Chap3.Get_Array_Bounds (Res)),
+         New_Convert_Ov (New_Obj_Value (Ptr), D_Info.T.Bounds_Ptr_Type));
+      New_Assign_Stmt
+        (M2Lp (Chap3.Get_Array_Base (Res)),
+         Chap3.Get_Bounds_Acc_Base (New_Obj_Value (Ptr), D_Type));
+      return Res;
+   end Bounds_Acc_To_Fat_Pointer;
+
    function Translate_Allocator_By_Subtype (Expr : Iir) return O_Enode
    is
-      P_Type   : constant Iir := Get_Type (Expr);
-      P_Info   : constant Type_Info_Acc := Get_Info (P_Type);
-      D_Type   : constant Iir := Get_Designated_Type (P_Type);
+      A_Type   : constant Iir := Get_Type (Expr);
+      A_Info   : constant Type_Info_Acc := Get_Info (A_Type);
+      D_Type   : constant Iir := Get_Designated_Type (A_Type);
       D_Info   : constant Type_Info_Acc := Get_Info (D_Type);
-      Sub_Type : Iir;
       Bounds   : Mnode;
       Res      : Mnode;
-      Rtype    : O_Tnode;
    begin
-      case P_Info.Type_Mode is
-         when Type_Mode_Fat_Acc =>
-            Res := Dv2M (Create_Temp (D_Info.Ortho_Type (Mode_Value)),
-                         D_Info, Mode_Value);
-            --  FIXME: should allocate bounds, and directly set bounds
-            --  from the range.
-            Sub_Type := Get_Subtype_Indication (Expr);
-            Sub_Type := Get_Type_Of_Subtype_Indication (Sub_Type);
-            Chap3.Create_Array_Subtype (Sub_Type, True);
-            Bounds := Chap3.Get_Array_Type_Bounds (Sub_Type);
-            Rtype := P_Info.Ortho_Ptr_Type (Mode_Value);
+      case A_Info.Type_Mode is
+         when Type_Mode_Bounds_Acc =>
+            declare
+               Sub_Type : Iir;
+               Ptr : O_Dnode;
+               Val_Size : O_Dnode;
+               Bounds_Size : O_Cnode;
+            begin
+               Sub_Type := Get_Subtype_Indication (Expr);
+               Sub_Type := Get_Type_Of_Subtype_Indication (Sub_Type);
+               Chap3.Create_Array_Subtype (Sub_Type, True);
+
+               Ptr := Create_Temp (A_Info.Ortho_Type (Mode_Value));
+
+               --  Size of the value (object without the bounds).
+               Val_Size := Create_Temp_Init
+                 (Ghdl_Index_Type,
+                  Chap3.Get_Subtype_Size
+                    (D_Type, Chap3.Get_Array_Type_Bounds (Sub_Type),
+                     Mode_Value));
+
+               --  Size of the bounds.
+               Bounds_Size :=
+                 New_Sizeof (D_Info.T.Bounds_Type, Ghdl_Index_Type);
+
+               --  Allocate the object.
+               New_Assign_Stmt
+                 (New_Obj (Ptr),
+                  Gen_Alloc (Alloc_Heap,
+                             New_Dyadic_Op
+                               (ON_Add_Ov,
+                                New_Lit (Bounds_Size),
+                                New_Obj_Value (Val_Size)),
+                             A_Info.Ortho_Type (Mode_Value)));
+
+               --  Copy bounds.
+               Gen_Memcpy
+                 (New_Obj_Value (Ptr),
+                  M2Addr (Chap3.Get_Array_Type_Bounds (Sub_Type)),
+                  New_Lit (Bounds_Size));
+
+               --  Create a fat pointer to initialize the object.
+               Res := Bounds_Acc_To_Fat_Pointer (Ptr, A_Type);
+               Chap3.Maybe_Call_Type_Builder (Res, D_Type);
+               Chap4.Init_Object (Res, D_Type);
+
+               return New_Obj_Value (Ptr);
+            end;
          when Type_Mode_Acc =>
             Res := Dp2M (Create_Temp (D_Info.Ortho_Ptr_Type (Mode_Value)),
                          D_Info, Mode_Value);
             Bounds := Mnode_Null;
-            Rtype := P_Info.Ortho_Type (Mode_Value);
+            Chap3.Translate_Object_Allocation
+              (Res, Alloc_Heap, D_Type, Bounds);
+            Chap4.Init_Object (Res, D_Type);
+            return New_Convert_Ov
+              (M2Addr (Res), A_Info.Ortho_Type (Mode_Value));
          when others =>
             raise Internal_Error;
       end case;
-      Chap3.Translate_Object_Allocation (Res, Alloc_Heap, D_Type, Bounds);
-      Chap4.Init_Object (Res, D_Type);
-      return New_Convert_Ov (M2Addr (Res), Rtype);
    end Translate_Allocator_By_Subtype;
 
    function Translate_Fat_Array_Type_Conversion
@@ -3770,28 +3856,8 @@ package body Trans.Chap7 is
             declare
                Tinfo : constant Type_Info_Acc := Get_Info (Expr_Type);
                Otype : constant O_Tnode := Tinfo.Ortho_Type (Mode_Value);
-               L     : O_Dnode;
-               B     : Type_Info_Acc;
             begin
-               if Tinfo.Type_Mode = Type_Mode_Fat_Acc then
-                  --  Create a fat null pointer.
-                  --  FIXME: should be optimized!!
-                  L := Create_Temp (Otype);
-                  B := Get_Info (Get_Designated_Type (Expr_Type));
-                  New_Assign_Stmt
-                    (New_Selected_Element (New_Obj (L),
-                     B.T.Base_Field (Mode_Value)),
-                     New_Lit
-                       (New_Null_Access (B.T.Base_Ptr_Type (Mode_Value))));
-                  New_Assign_Stmt
-                    (New_Selected_Element
-                       (New_Obj (L), B.T.Bounds_Field (Mode_Value)),
-                     New_Lit (New_Null_Access (B.T.Bounds_Ptr_Type)));
-                  return New_Address (New_Obj (L),
-                                      Tinfo.Ortho_Ptr_Type (Mode_Value));
-               else
-                  return New_Lit (New_Null_Access (Otype));
-               end if;
+               return New_Lit (New_Null_Access (Otype));
             end;
 
          when Iir_Kind_Overflow_Literal =>
@@ -4446,35 +4512,10 @@ package body Trans.Chap7 is
       Tinfo := Get_Type_Info (L);
       case Tinfo.Type_Mode is
          when Type_Mode_Scalar
-            | Type_Mode_Acc =>
+           | Type_Mode_Bounds_Acc
+           | Type_Mode_Acc =>
             return New_Compare_Op (ON_Eq, M2E (L), M2E (R),
                                    Ghdl_Bool_Type);
-         when Type_Mode_Fat_Acc =>
-            --  a fat pointer.
-            declare
-               B      : Type_Info_Acc;
-               Ln, Rn : Mnode;
-               V1, V2 : O_Enode;
-            begin
-               B := Get_Info (Get_Designated_Type (Etype));
-               Ln := Stabilize (L);
-               Rn := Stabilize (R);
-               V1 := New_Compare_Op
-                 (ON_Eq,
-                  New_Value (New_Selected_Element
-                    (M2Lv (Ln), B.T.Base_Field (Mode_Value))),
-                  New_Value (New_Selected_Element
-                    (M2Lv (Rn), B.T.Base_Field (Mode_Value))),
-                  Std_Boolean_Type_Node);
-               V2 := New_Compare_Op
-                 (ON_Eq,
-                  New_Value (New_Selected_Element
-                    (M2Lv (Ln), B.T.Bounds_Field (Mode_Value))),
-                  New_Value (New_Selected_Element
-                    (M2Lv (Rn), B.T.Bounds_Field (Mode_Value))),
-                  Std_Boolean_Type_Node);
-               return New_Dyadic_Op (ON_And, V1, V2);
-            end;
 
          when Type_Mode_Array =>
             declare
@@ -5280,7 +5321,7 @@ package body Trans.Chap7 is
             when Type_Mode_Unknown
                | Type_Mode_File
                | Type_Mode_Acc
-               | Type_Mode_Fat_Acc
+               | Type_Mode_Bounds_Acc
                | Type_Mode_Fat_Array
                | Type_Mode_Protected =>
                raise Internal_Error;
diff --git a/src/vhdl/translate/trans-chap7.ads b/src/vhdl/translate/trans-chap7.ads
index 8aa9042..2434c3b 100644
--- a/src/vhdl/translate/trans-chap7.ads
+++ b/src/vhdl/translate/trans-chap7.ads
@@ -114,6 +114,10 @@ package Trans.Chap7 is
    procedure Translate_Aggregate
      (Target : Mnode; Target_Type : Iir; Aggr : Iir);
 
+   --  Convert bounds access PTR to a fat pointer.
+   function Bounds_Acc_To_Fat_Pointer (Ptr : O_Dnode; Acc_Type : Iir)
+                                      return Mnode;
+
    --  Translate implicit functions defined by a type.
    type Implicit_Subprogram_Infos is private;
    procedure Init_Implicit_Subprogram_Infos
diff --git a/src/vhdl/translate/trans-chap8.adb b/src/vhdl/translate/trans-chap8.adb
index 8a3711e..ca05eb6 100644
--- a/src/vhdl/translate/trans-chap8.adb
+++ b/src/vhdl/translate/trans-chap8.adb
@@ -97,8 +97,9 @@ package body Trans.Chap8 is
                   Gen_Return_Value (R);
                end if;
             end;
-         when Type_Mode_Acc =>
-            --  * access: thin and no range.
+         when Type_Mode_Acc
+           | Type_Mode_Bounds_Acc =>
+            --  * access: no range.
             declare
                Res : O_Enode;
             begin
@@ -126,8 +127,7 @@ package body Trans.Chap8 is
                Gen_Return;
             end;
          when Type_Mode_Record
-            | Type_Mode_Array
-            | Type_Mode_Fat_Acc =>
+            | Type_Mode_Array =>
             --  * if the return type is a constrained composite type, copy
             --    it to the result area.
             --  Create a temporary area so that if the expression use
@@ -1351,7 +1351,7 @@ package body Trans.Chap8 is
          when Type_Mode_Unknown
             | Type_Mode_File
             | Type_Mode_Acc
-            | Type_Mode_Fat_Acc
+            | Type_Mode_Bounds_Acc
             | Type_Mode_Protected =>
             raise Internal_Error;
       end case;
@@ -1424,7 +1424,7 @@ package body Trans.Chap8 is
          when Type_Mode_Unknown
             | Type_Mode_File
             | Type_Mode_Acc
-            | Type_Mode_Fat_Acc
+            | Type_Mode_Bounds_Acc
             | Type_Mode_Protected =>
             raise Internal_Error;
       end case;
@@ -1704,6 +1704,7 @@ package body Trans.Chap8 is
       Is_Procedure : constant Boolean :=
         Get_Kind (Imp) = Iir_Kind_Procedure_Declaration;
       Is_Function : constant Boolean := not Is_Procedure;
+      Is_Foreign : constant Boolean := Get_Foreign_Flag (Imp);
       Info : constant Subprg_Info_Acc := Get_Info (Imp);
 
       type Mnode_Array is array (Natural range <>) of Mnode;
@@ -1718,6 +1719,10 @@ package body Trans.Chap8 is
       --  The values of actuals.
       E_Params : O_Enode_Array (0 .. Nbr_Assoc - 1);
 
+      --  Only for inout/out variables passed by copy of foreign procedures:
+      --  the copy of the scalar.
+      Inout_Params : Mnode_Array (0 .. Nbr_Assoc - 1);
+
       Params_Var : O_Dnode;
       Res : Mnode;
       El : Iir;
@@ -1777,6 +1782,7 @@ package body Trans.Chap8 is
       while El /= Null_Iir loop
          Params (Pos) := Mnode_Null;
          E_Params (Pos) := O_Enode_Null;
+         Inout_Params (Pos) := Mnode_Null;
 
          Formal := Strip_Denoting_Name (Get_Formal (El));
          Base_Formal := Get_Association_Interface (El);
@@ -1853,7 +1859,7 @@ package body Trans.Chap8 is
                else
                   Param := Chap6.Translate_Name (Act);
                   if Base_Formal /= Formal
-                    or else Ftype_Info.Type_Mode in Type_Mode_By_Value
+                    or else Ftype_Info.Type_Mode in Type_Mode_Pass_By_Copy
                   then
                      --  For out/inout, we need to keep the reference for the
                      --  copy-out.
@@ -1872,6 +1878,16 @@ package body Trans.Chap8 is
                   else
                      Val := M2E (Param);
                   end if;
+
+                  if Is_Foreign
+                    and then Ftype_Info.Type_Mode in Type_Mode_Pass_By_Copy
+                  then
+                     --  Scalar parameters of foreign procedures (of mode out
+                     --  or inout) are passed by address, create a copy of the
+                     --  value.
+                     Inout_Params (Pos) :=
+                       Create_Temp (Ftype_Info, Mode_Value);
+                  end if;
                end if;
                if In_Conv /= Null_Iir then
                   Val := Do_Conversion (In_Conv, Act, Val);
@@ -1906,6 +1922,8 @@ package body Trans.Chap8 is
             Ptr := New_Selected_Element
               (New_Obj (Params_Var), Formal_Info.Interface_Field);
             New_Assign_Stmt (Ptr, Val);
+         elsif Inout_Params (Pos) /= Mnode_Null then
+            Chap3.Translate_Object_Copy (Inout_Params (Pos), Val, Formal_Type);
          else
             E_Params (Pos) := Val;
          end if;
@@ -1952,7 +1970,12 @@ package body Trans.Chap8 is
                New_Association (Constr, M2E (Params (Pos)));
             elsif Base_Formal = Formal then
                --  Whole association.
-               New_Association (Constr, E_Params (Pos));
+               if Inout_Params (Pos) /= Mnode_Null then
+                  Val := M2Addr (Inout_Params (Pos));
+               else
+                  Val := E_Params (Pos);
+               end if;
+               New_Association (Constr, Val);
             end if;
          end if;
          El := Get_Chain (El);
@@ -1995,6 +2018,8 @@ package body Trans.Chap8 is
                --  By individual, copy back.
                Param := Translate_Individual_Association_Formal
                  (Formal, Formal_Info, Params (Last_Individual));
+            elsif Inout_Params (Pos) /= Mnode_Null then
+               Param := Inout_Params (Pos);
             else
                pragma Assert (Formal_Info.Interface_Field /= O_Fnode_Null);
                Ptr := New_Selected_Element
diff --git a/src/vhdl/translate/trans-chap9.adb b/src/vhdl/translate/trans-chap9.adb
index 86faf6a..9a7bf98 100644
--- a/src/vhdl/translate/trans-chap9.adb
+++ b/src/vhdl/translate/trans-chap9.adb
@@ -58,8 +58,8 @@ package body Trans.Chap9 is
             Sig := Get_Object_Prefix (Drivers (I).Sig);
             Info := Get_Info (Sig);
             case Info.Kind is
-               when Kind_Object =>
-                  Info.Object_Driver := Var;
+               when Kind_Signal =>
+                  Info.Signal_Driver := Var;
                when Kind_Alias =>
                   null;
                when others =>
@@ -83,8 +83,8 @@ package body Trans.Chap9 is
             Sig := Get_Object_Prefix (Drivers (I).Sig);
             Info := Get_Info (Sig);
             case Info.Kind is
-               when Kind_Object =>
-                  Info.Object_Driver := Null_Var;
+               when Kind_Signal =>
+                  Info.Signal_Driver := Null_Var;
                when Kind_Alias =>
                   null;
                when others =>
@@ -122,21 +122,19 @@ package body Trans.Chap9 is
    procedure Translate_Implicit_Guard_Signal
      (Guard : Iir; Base : Block_Info_Acc)
    is
-      Info       : Object_Info_Acc;
+      Guard_Expr : constant Iir := Get_Guard_Expression (Guard);
+      Info       : constant Signal_Info_Acc := Get_Info (Guard);
       Inter_List : O_Inter_List;
       Instance   : O_Dnode;
-      Guard_Expr : Iir;
    begin
-      Guard_Expr := Get_Guard_Expression (Guard);
       --  Create the subprogram to compute the value of GUARD.
-      Info := Get_Info (Guard);
       Start_Function_Decl (Inter_List, Create_Identifier ("_GUARD_PROC"),
                            O_Storage_Private, Std_Boolean_Type_Node);
       New_Interface_Decl (Inter_List, Instance, Wki_Instance,
                           Base.Block_Decls_Ptr_Type);
-      Finish_Subprogram_Decl (Inter_List, Info.Object_Function);
+      Finish_Subprogram_Decl (Inter_List, Info.Signal_Function);
 
-      Start_Subprogram_Body (Info.Object_Function);
+      Start_Subprogram_Body (Info.Signal_Function);
       Push_Local_Factory;
       Set_Scope_Via_Param_Ptr (Base.Block_Scope, Instance);
       Open_Temp;
@@ -1325,27 +1323,24 @@ package body Trans.Chap9 is
    procedure Elab_Implicit_Guard_Signal
      (Block : Iir_Block_Statement; Block_Info : Block_Info_Acc)
    is
-      Guard     : Iir;
-      Type_Info : Type_Info_Acc;
-      Info      : Object_Info_Acc;
+      Guard     : constant Iir := Get_Guard_Decl (Block);
+      Info      : constant Signal_Info_Acc := Get_Info (Guard);
+      Type_Info : constant Type_Info_Acc := Get_Info (Get_Type (Guard));
       Constr    : O_Assoc_List;
    begin
       --  Create the guard signal.
-      Guard := Get_Guard_Decl (Block);
-      Info := Get_Info (Guard);
-      Type_Info := Get_Info (Get_Type (Guard));
       Start_Association (Constr, Ghdl_Signal_Create_Guard);
       New_Association
         (Constr, New_Unchecked_Address
            (Get_Instance_Ref (Block_Info.Block_Scope), Ghdl_Ptr_Type));
       New_Association
         (Constr,
-         New_Lit (New_Subprogram_Address (Info.Object_Function,
-           Ghdl_Ptr_Type)));
+         New_Lit (New_Subprogram_Address (Info.Signal_Function,
+                                          Ghdl_Ptr_Type)));
       --         New_Association (Constr, Chap6.Get_Instance_Name_Ref (Block));
-      New_Assign_Stmt (Get_Var (Info.Object_Var),
+      New_Assign_Stmt (Get_Var (Info.Signal_Sig),
                        New_Convert_Ov (New_Function_Call (Constr),
-                         Type_Info.Ortho_Type (Mode_Signal)));
+                                       Type_Info.Ortho_Type (Mode_Signal)));
 
       --  Register sensitivity list of the guard signal.
       Register_Signal_List (Get_Guard_Sensitivity_List (Guard),
@@ -1840,16 +1835,15 @@ package body Trans.Chap9 is
       New_Association
         (Assoc,
          New_Lit (New_Global_Unchecked_Address
-           (Get_Info (Data.Sig).Object_Rti,
-                Rtis.Ghdl_Rti_Access)));
+                    (Get_Info (Data.Sig).Signal_Rti,
+                     Rtis.Ghdl_Rti_Access)));
       New_Procedure_Call (Assoc);
       Close_Temp;
    end Merge_Signals_Rti_Non_Composite;
 
-   function Merge_Signals_Rti_Prepare (Targ      : Mnode;
-                                       Targ_Type : Iir;
-                                       Data      : Merge_Signals_Data)
-                                          return Merge_Signals_Data
+   function Merge_Signals_Rti_Prepare
+     (Targ : Mnode; Targ_Type : Iir; Data : Merge_Signals_Data)
+     return Merge_Signals_Data
    is
       pragma Unreferenced (Targ);
       pragma Unreferenced (Targ_Type);
@@ -1934,26 +1928,27 @@ package body Trans.Chap9 is
       while Port /= Null_Iir loop
          Port_Type := Get_Type (Port);
          Data.Sig := Port;
+         Open_Temp;
+
          case Get_Mode (Port) is
             when Iir_Buffer_Mode
                | Iir_Out_Mode
                | Iir_Inout_Mode =>
                Data.Set_Init := True;
+               Val := Get_Default_Value (Port);
+               if Val = Null_Iir then
+                  Data.Has_Val := False;
+               else
+                  Data.Has_Val := True;
+                  Data.Val := E2M (Chap7.Translate_Expression (Val, Port_Type),
+                                   Get_Info (Port_Type),
+                                   Mode_Value);
+               end if;
             when others =>
                Data.Set_Init := False;
+               Data.Has_Val := False;
          end case;
 
-         Open_Temp;
-         Val := Get_Default_Value (Port);
-         if Val = Null_Iir then
-            Data.Has_Val := False;
-         else
-            Data.Has_Val := True;
-            Data.Val := E2M (Chap7.Translate_Expression (Val, Port_Type),
-                             Get_Info (Port_Type),
-                             Mode_Value);
-         end if;
-
          Merge_Signals_Rti (Chap6.Translate_Name (Port), Port_Type, Data);
          Close_Temp;
 
diff --git a/src/vhdl/translate/trans-rtis.adb b/src/vhdl/translate/trans-rtis.adb
index a55447a..cae059b 100644
--- a/src/vhdl/translate/trans-rtis.adb
+++ b/src/vhdl/translate/trans-rtis.adb
@@ -1813,10 +1813,9 @@ package body Trans.Rtis is
 
    procedure Generate_Signal_Rti (Sig : Iir)
    is
-      Info : Object_Info_Acc;
+      Info : constant Signal_Info_Acc := Get_Info (Sig);
    begin
-      Info := Get_Info (Sig);
-      New_Const_Decl (Info.Object_Rti, Create_Identifier (Sig, "__RTI"),
+      New_Const_Decl (Info.Signal_Rti, Create_Identifier (Sig, "__RTI"),
                       Global_Storage, Ghdl_Rtin_Object);
    end Generate_Signal_Rti;
 
@@ -1895,10 +1894,10 @@ package body Trans.Rtis is
          case Get_Kind (Decl) is
             when Iir_Kind_Signal_Declaration =>
                Comm := Ghdl_Rtik_Signal;
-               Var := Info.Object_Var;
+               Var := Info.Signal_Sig;
             when Iir_Kind_Interface_Signal_Declaration =>
                Comm := Ghdl_Rtik_Port;
-               Var := Info.Object_Var;
+               Var := Info.Signal_Sig;
                Mode := Iir_Mode'Pos (Get_Mode (Decl));
             when Iir_Kind_Constant_Declaration =>
                Comm := Ghdl_Rtik_Constant;
@@ -1911,7 +1910,7 @@ package body Trans.Rtis is
                Var := Info.Object_Var;
             when Iir_Kind_Guard_Signal_Declaration =>
                Comm := Ghdl_Rtik_Guard;
-               Var := Info.Object_Var;
+               Var := Info.Signal_Sig;
             when Iir_Kind_Iterator_Declaration =>
                Comm := Ghdl_Rtik_Iterator;
                Var := Info.Iterator_Var;
@@ -1923,13 +1922,13 @@ package body Trans.Rtis is
                Var := Null_Var;
             when Iir_Kind_Transaction_Attribute =>
                Comm := Ghdl_Rtik_Attribute_Transaction;
-               Var := Info.Object_Var;
+               Var := Info.Signal_Sig;
             when Iir_Kind_Quiet_Attribute =>
                Comm := Ghdl_Rtik_Attribute_Quiet;
-               Var := Info.Object_Var;
+               Var := Info.Signal_Sig;
             when Iir_Kind_Stable_Attribute =>
                Comm := Ghdl_Rtik_Attribute_Stable;
-               Var := Info.Object_Var;
+               Var := Info.Signal_Sig;
             when Iir_Kind_Object_Alias_Declaration =>
                Comm := Ghdl_Rtik_Alias;
                Var := Info.Alias_Var;
@@ -2207,20 +2206,25 @@ package body Trans.Rtis is
                      Add_Rti_Node (Info.Object_Rti);
                   end;
                end if;
+            when Iir_Kind_Interface_Constant_Declaration
+               | Iir_Kind_Variable_Declaration
+               | Iir_Kind_File_Declaration =>
+               declare
+                  Info : constant Object_Info_Acc := Get_Info (Decl);
+               begin
+                  Generate_Object (Decl, Info.Object_Rti);
+                  Add_Rti_Node (Info.Object_Rti);
+               end;
             when Iir_Kind_Signal_Declaration
                | Iir_Kind_Interface_Signal_Declaration
-               | Iir_Kind_Interface_Constant_Declaration
-               | Iir_Kind_Variable_Declaration
-               | Iir_Kind_File_Declaration
                | Iir_Kind_Transaction_Attribute
                | Iir_Kind_Quiet_Attribute
                | Iir_Kind_Stable_Attribute =>
                declare
-                  Info : Object_Info_Acc;
+                  Info : constant Signal_Info_Acc := Get_Info (Decl);
                begin
-                  Info := Get_Info (Decl);
-                  Generate_Object (Decl, Info.Object_Rti);
-                  Add_Rti_Node (Info.Object_Rti);
+                  Generate_Object (Decl, Info.Signal_Rti);
+                  Add_Rti_Node (Info.Signal_Rti);
                end;
             when Iir_Kind_Delayed_Attribute =>
                --  FIXME: to be added.
@@ -2530,12 +2534,12 @@ package body Trans.Rtis is
             declare
                Guard      : constant Iir := Get_Guard_Decl (Blk);
                Header     : constant Iir := Get_Block_Header (Blk);
-               Guard_Info : Object_Info_Acc;
+               Guard_Info : Signal_Info_Acc;
             begin
                if Guard /= Null_Iir then
                   Guard_Info := Get_Info (Guard);
-                  Generate_Object (Guard, Guard_Info.Object_Rti);
-                  Add_Rti_Node (Guard_Info.Object_Rti);
+                  Generate_Object (Guard, Guard_Info.Signal_Rti);
+                  Add_Rti_Node (Guard_Info.Signal_Rti);
                end if;
                if Header /= Null_Iir then
                   Generate_Declaration_Chain (Get_Generic_Chain (Header));
diff --git a/src/vhdl/translate/trans.adb b/src/vhdl/translate/trans.adb
index 91ebb9e..de5abc3 100644
--- a/src/vhdl/translate/trans.adb
+++ b/src/vhdl/translate/trans.adb
@@ -1054,7 +1054,7 @@ package body Trans is
             | Type_Mode_Acc
             | Type_Mode_File
             | Type_Mode_Fat_Array
-            | Type_Mode_Fat_Acc =>
+            | Type_Mode_Bounds_Acc =>
             if Stable then
                return Dv2M (D, Vtype, Mode);
             else
@@ -1204,6 +1204,17 @@ package body Trans is
       return New_Access_Element (New_Value (L));
    end New_Acc_Value;
 
+   function Add_Pointer
+     (Ptr : O_Enode; Offset : O_Enode; Res_Ptr : O_Tnode) return O_Enode is
+   begin
+      return New_Unchecked_Address
+        (New_Slice
+           (New_Access_Element (New_Convert_Ov (Ptr, Char_Ptr_Type)),
+            Chararray_Type,
+            Offset),
+         Res_Ptr);
+   end Add_Pointer;
+
    package Node_Infos is new GNAT.Table
      (Table_Component_Type => Ortho_Info_Acc,
       Table_Index_Type => Iir,
@@ -1668,7 +1679,7 @@ package body Trans is
             | Type_Mode_Acc
             | Type_Mode_File
             | Type_Mode_Fat_Array
-            | Type_Mode_Fat_Acc =>
+            | Type_Mode_Bounds_Acc =>
             return Lv2M (L, Vtype, Mode);
          when Type_Mode_Array
             | Type_Mode_Record
@@ -1691,7 +1702,7 @@ package body Trans is
             | Type_Mode_Acc
             | Type_Mode_File
             | Type_Mode_Fat_Array
-            | Type_Mode_Fat_Acc =>
+            | Type_Mode_Bounds_Acc =>
             return Dv2M (D, Vtype, Mode);
          when Type_Mode_Array
             | Type_Mode_Record
@@ -1741,11 +1752,24 @@ package body Trans is
       type Temp_Level_Type;
       type Temp_Level_Acc is access Temp_Level_Type;
       type Temp_Level_Type is record
+         --  Link to the outer record.
          Prev            : Temp_Level_Acc;
+
+         --  Nested level.  'Top' level is 0.
          Level           : Natural;
+
+         --  Generated variable id, starts from 0.
          Id              : Natural;
+
+         --  True if a scope was created, as it is created dynamically at the
+         --  first use.
          Emitted         : Boolean;
+
+         --  Declaration of the variable for the stack2 mark.  The stack2 will
+         --  be released at the end of the scope (if used).
          Stack2_Mark     : O_Dnode;
+
+         --  List of transient types to be removed at the end of the scope.
          Transient_Types : Iir;
       end record;
       --  Current level.
diff --git a/src/vhdl/translate/trans.ads b/src/vhdl/translate/trans.ads
index 8cf76b7..b135929 100644
--- a/src/vhdl/translate/trans.ads
+++ b/src/vhdl/translate/trans.ads
@@ -157,6 +157,8 @@ package Trans is
    Wki_Val           : O_Ident;
    Wki_L_Len         : O_Ident;
    Wki_R_Len         : O_Ident;
+   Wki_Base          : O_Ident;
+   Wki_Bounds        : O_Ident;
 
    --  ALLOCATION_KIND defines the type of memory storage.
    --  ALLOC_STACK means the object is allocated on the local stack and
@@ -183,6 +185,12 @@ package Trans is
    --  Equivalent to new_access_element (new_value (l))
    function New_Acc_Value (L : O_Lnode) return O_Lnode;
 
+   --  Return PTR + OFFSET as a RES_PTR value.  The offset is the number of
+   --  bytes.  RES_PTR must be an access type and the type of PTR must be an
+   --  access.
+   function Add_Pointer
+     (Ptr : O_Enode; Offset : O_Enode; Res_Ptr : O_Tnode) return O_Enode;
+
    package Chap10 is
       --  There are three data storage kind: global, local or instance.
       --  For example, a constant can have:
@@ -635,6 +643,7 @@ package Trans is
       Kind_Expr,
       Kind_Subprg,
       Kind_Object,
+      Kind_Signal,
       Kind_Alias,
       Kind_Iterator,
       Kind_Interface,
@@ -790,6 +799,7 @@ package Trans is
      (
       --  Unknown mode.
       Type_Mode_Unknown,
+
       --  Boolean type, with 2 elements.
       Type_Mode_B1,
       --  Enumeration with at most 256 elements.
@@ -809,8 +819,8 @@ package Trans is
       --  Thin access.
       Type_Mode_Acc,
 
-      --  Fat access.
-      Type_Mode_Fat_Acc,
+      --  Access to an unbounded type.
+      Type_Mode_Bounds_Acc,
 
       --  Record.
       Type_Mode_Record,
@@ -821,43 +831,72 @@ package Trans is
       --  Fat array type (used for unconstrained array).
       Type_Mode_Fat_Array);
 
-   subtype Type_Mode_Scalar is Type_Mode_Type
-   range Type_Mode_B1 .. Type_Mode_F64;
+   subtype Type_Mode_Valid is Type_Mode_Type range
+     Type_Mode_B1 .. Type_Mode_Type'Last;
 
-   subtype Type_Mode_Non_Composite is Type_Mode_Type
-   range Type_Mode_B1 .. Type_Mode_Fat_Acc;
+   subtype Type_Mode_Scalar is Type_Mode_Type range
+     Type_Mode_B1 .. Type_Mode_F64;
 
    --  Composite types, with the vhdl meaning: record and arrays.
-   subtype Type_Mode_Composite is Type_Mode_Type
-   range Type_Mode_Record .. Type_Mode_Fat_Array;
+   subtype Type_Mode_Composite is Type_Mode_Type range
+     Type_Mode_Record .. Type_Mode_Fat_Array;
+
+   subtype Type_Mode_Non_Composite is Type_Mode_Type range
+     Type_Mode_B1 .. Type_Mode_Bounds_Acc;
 
    --  Array types.
    subtype Type_Mode_Arrays is Type_Mode_Type range
      Type_Mode_Array .. Type_Mode_Fat_Array;
 
    --  Thin types, ie types whose length is a scalar.
-   subtype Type_Mode_Thin is Type_Mode_Type
-   range Type_Mode_B1 .. Type_Mode_Acc;
+   subtype Type_Mode_Thin is Type_Mode_Type range
+     Type_Mode_B1 .. Type_Mode_Bounds_Acc;
 
    --  Fat types, ie types whose length is longer than a scalar.
-   subtype Type_Mode_Fat is Type_Mode_Type
-   range Type_Mode_Fat_Acc .. Type_Mode_Fat_Array;
+   subtype Type_Mode_Fat is Type_Mode_Type range
+     Type_Mode_Record .. Type_Mode_Fat_Array;
 
-   --  These parameters are passed by value, ie the argument of the subprogram
-   --  is the value of the object.
-   subtype Type_Mode_By_Value is Type_Mode_Type
-   range Type_Mode_B1 .. Type_Mode_Acc;
+   --  Subprogram call argument mechanism.
+   --  In VHDL, the evaluation is strict: actual parameters are evaluated
+   --  before the call.  This is the usual strategy of most compiled languages
+   --  (the main exception being Algol-68 call by name).
+   --
+   --  Call semantic is described in
+   --  LRM08 4.2.2.2 Constant and variable parameters.
+   --
+   --  At the semantic (and LRM level), there are two call convention: either
+   --  call by value or call by reference.  That vocabulary should be used in
+   --  trans for the semantic level: call convention and call-by.  According to
+   --  the LRM, all scalars use the call by value convention.  It is possible
+   --  to change the actual after the call for inout parameters, using
+   --  pass-by value mechanism and copy-in/copy-out.
+   --
+   --  At the low-level (generated code), there are two mechanisms: either
+   --  pass by copy or pass by address.  Again, that vocabulary should be used
+   --  in trans for the low-level: mechanism and pass-by.
+   --
+   --  A call by reference is always passed by address; while a call by value
+   --  can use a pass-by address to a copy of the value.  The later being
+   --  used for fat accesses.  With Ortho, only scalars and pointers can be
+   --  passed by copy.
 
-   --  These parameters are passed by copy, ie a copy of the object is created
-   --  and the reference of the copy is passed.  If the object is not
-   --  modified by the subprogram, the object could be passed by reference.
-   subtype Type_Mode_By_Copy is Type_Mode_Type
-   range Type_Mode_Fat_Acc .. Type_Mode_Fat_Acc;
+   --  In GHDL, all non-composite types use the call-by value convention, and
+   --  composite types use the call-by reference convention.  For fat accesses,
+   --  a copy of the value is passed by address.
 
-   --  The parameters are passed by reference, ie the argument of the
+   --  These parameters are passed by copy, ie the argument of the subprogram
+   --  is the value of the object.
+   subtype Type_Mode_Pass_By_Copy is Type_Mode_Type range
+     Type_Mode_B1 .. Type_Mode_Bounds_Acc;
+
+   --  The parameters are passed by address, ie the argument of the
    --  subprogram is an address to the object.
-   subtype Type_Mode_By_Ref is Type_Mode_Type
-   range Type_Mode_Record .. Type_Mode_Fat_Array;
+   subtype Type_Mode_Pass_By_Address is Type_Mode_Type range
+     Type_Mode_Record .. Type_Mode_Fat_Array;
+
+   --  Call conventions.
+   subtype Type_Mode_Call_By_Value is Type_Mode_Non_Composite;
+   subtype Type_Mode_Call_By_Reference is Type_Mode_Composite;
 
    --  Additional informations for a resolving function.
    type Subprg_Resolv_Info is record
@@ -1076,7 +1115,6 @@ package Trans is
          when Kind_Incomplete_Type =>
             --  The declaration of the incomplete type.
             Incomplete_Type  : Iir;
-            Incomplete_Array : Ortho_Info_Acc;
 
          when Kind_Index =>
             --  Field declaration for array dimension.
@@ -1139,13 +1177,21 @@ package Trans is
             Object_Static   : Boolean;
             --  The object itself.
             Object_Var      : Var_Type;
-            --  Direct driver for signal (if any).
-            Object_Driver   : Var_Type := Null_Var;
             --  RTI constant for the object.
             Object_Rti      : O_Dnode := O_Dnode_Null;
+
+         when Kind_Signal =>
+            --  The current value of the signal.
+            Signal_Value    : Var_Type := Null_Var;
+            --  A pointer to the signal (contains meta data).
+            Signal_Sig      : Var_Type;
+            --  Direct driver for signal (if any).
+            Signal_Driver   : Var_Type := Null_Var;
+            --  RTI constant for the object.
+            Signal_Rti      : O_Dnode := O_Dnode_Null;
             --  Function to compute the value of object (used for implicit
             --   guard signal declaration).
-            Object_Function : O_Dnode := O_Dnode_Null;
+            Signal_Function : O_Dnode := O_Dnode_Null;
 
          when Kind_Alias =>
             Alias_Var  : Var_Type;
@@ -1383,6 +1429,7 @@ package Trans is
    subtype Index_Info_Acc is Ortho_Info_Acc (Kind_Index);
    subtype Subprg_Info_Acc is Ortho_Info_Acc (Kind_Subprg);
    subtype Object_Info_Acc is Ortho_Info_Acc (Kind_Object);
+   subtype Signal_Info_Acc is Ortho_Info_Acc (Kind_Signal);
    subtype Alias_Info_Acc is Ortho_Info_Acc (Kind_Alias);
    subtype Proc_Info_Acc is Ortho_Info_Acc (Kind_Process);
    subtype Psl_Info_Acc is Ortho_Info_Acc (Kind_Psl_Directive);
diff --git a/src/vhdl/translate/translation.adb b/src/vhdl/translate/translation.adb
index 516c3e9..a3d2375 100644
--- a/src/vhdl/translate/translation.adb
+++ b/src/vhdl/translate/translation.adb
@@ -390,6 +390,8 @@ package body Translation is
       Wki_Val := Get_Identifier ("val");
       Wki_L_Len := Get_Identifier ("l_len");
       Wki_R_Len := Get_Identifier ("r_len");
+      Wki_Base := Get_Identifier ("BASE");
+      Wki_Bounds := Get_Identifier ("BOUNDS");
 
       Sizetype := New_Unsigned_Type (32);
       New_Type_Decl (Get_Identifier ("__ghdl_size_type"), Sizetype);