| ------------------------------------------------------------------------------ |
| -- -- |
| -- GNAT RUN-TIME COMPONENTS -- |
| -- -- |
| -- I N T E R F A C E S . C P P -- |
| -- -- |
| -- B o d y -- |
| -- -- |
| -- Copyright (C) 1992-2005, Free Software Foundation, Inc. -- |
| -- -- |
| -- GNAT is free software; you can redistribute it and/or modify it under -- |
| -- terms of the GNU General Public License as published by the Free Soft- -- |
| -- ware Foundation; either version 2, or (at your option) any later ver- -- |
| -- sion. GNAT is distributed in the hope that it will be useful, but WITH- -- |
| -- OUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY -- |
| -- or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License -- |
| -- for more details. You should have received a copy of the GNU General -- |
| -- Public License distributed with GNAT; see file COPYING. If not, write -- |
| -- to the Free Software Foundation, 59 Temple Place - Suite 330, Boston, -- |
| -- MA 02111-1307, USA. -- |
| -- -- |
| -- As a special exception, if other files instantiate generics from this -- |
| -- unit, or you link this unit with other files to produce an executable, -- |
| -- this unit does not by itself cause the resulting executable to be -- |
| -- covered by the GNU General Public License. This exception does not -- |
| -- however invalidate any other reasons why the executable file might be -- |
| -- covered by the GNU Public License. -- |
| -- -- |
| -- GNAT was originally developed by the GNAT team at New York University. -- |
| -- Extensive contributions were provided by Ada Core Technologies Inc. -- |
| -- -- |
| ------------------------------------------------------------------------------ |
| |
| with Ada.Tags; use Ada.Tags; |
| with System; use System; |
| with System.Storage_Elements; use System.Storage_Elements; |
| |
| package body Interfaces.CPP is |
| |
| -- Structure of the Dispatch Table |
| |
| -- +-----------------------+ |
| -- | Offset_To_Top | |
| -- +-----------------------+ |
| -- | Typeinfo_Ptr/TSD_Ptr |----> Type Specific Data |
| -- Tag ---> +-----------------------+ +-------------------+ |
| -- | table of | | inheritance depth | |
| -- : primitive ops : +-------------------+ |
| -- | pointers | | expanded name | |
| -- +-----------------------+ +-------------------+ |
| -- | external tag | |
| -- +-------------------+ |
| -- | Hash table link | |
| -- +-------------------+ |
| -- | Remotely Callable | |
| -- +-------------------+ |
| -- | Rec Ctrler offset | |
| -- +-------------------+ |
| -- | table of | |
| -- : ancestor : |
| -- | tags | |
| -- +-------------------+ |
| |
| -- The declarations below need (extensive) comments ??? |
| |
| subtype Cstring is String (Positive); |
| type Cstring_Ptr is access all Cstring; |
| type Tag_Table is array (Natural range <>) of Vtable_Ptr; |
| pragma Suppress_Initialization (Tag_Table); |
| |
| type Type_Specific_Data is record |
| Idepth : Natural; |
| Expanded_Name : Cstring_Ptr; |
| External_Tag : Cstring_Ptr; |
| HT_Link : Tag; |
| Ancestor_Tags : Tag_Table (Natural); |
| end record; |
| |
| type Vtable_Entry is record |
| Pfn : System.Address; |
| end record; |
| |
| type Vtable_Entry_Array is array (Positive range <>) of Vtable_Entry; |
| |
| type VTable is record |
| -- Offset_To_Top : Integer; |
| -- Typeinfo_Ptr : System.Address; -- TSD is currently also here??? |
| Prims_Ptr : Vtable_Entry_Array (Positive); |
| end record; |
| -- Note: See comment in a-tags.adb explaining why the components |
| -- Offset_To_Top and Typeinfo_Ptr have been commented out. |
| -- ----------------------------------------------------------------------- |
| -- The size of the Prims_Ptr array actually depends on the tagged type to |
| -- which it applies. For each tagged type, the expander computes the |
| -- actual array size, allocates the Dispatch_Table record accordingly, and |
| -- generates code that displaces the base of the record after the |
| -- Typeinfo_Ptr component. For this reason the first two components have |
| -- been commented in the previous declaration. The access to these |
| -- components is done by means of local functions. |
| |
| --------------------------- |
| -- Unchecked Conversions -- |
| --------------------------- |
| |
| type Int_Ptr is access Integer; |
| |
| function To_Int_Ptr is |
| new Unchecked_Conversion (System.Address, Int_Ptr); |
| |
| function To_Cstring_Ptr is |
| new Unchecked_Conversion (Address, Cstring_Ptr); |
| |
| function To_Address is |
| new Unchecked_Conversion (Cstring_Ptr, Address); |
| |
| ----------------------- |
| -- Local Subprograms -- |
| ----------------------- |
| |
| function Length (Str : Cstring_Ptr) return Natural; |
| -- Length of string represented by the given pointer (treating the string |
| -- as a C-style string, which is Nul terminated). |
| |
| function Offset_To_Top (T : Vtable_Ptr) return Integer; |
| -- Returns the current value of the offset_to_top component available in |
| -- the prologue of the dispatch table. |
| |
| function Typeinfo_Ptr (T : Vtable_Ptr) return System.Address; |
| -- Returns the current value of the typeinfo_ptr component available in |
| -- the prologue of the dispatch table. |
| |
| pragma Unreferenced (Offset_To_Top); |
| pragma Unreferenced (Typeinfo_Ptr); |
| -- These functions will be used for full compatibility with the C++ ABI |
| |
| ----------------------- |
| -- CPP_CW_Membership -- |
| ----------------------- |
| |
| function CPP_CW_Membership |
| (Obj_Tag : Vtable_Ptr; |
| Typ_Tag : Vtable_Ptr) return Boolean |
| is |
| Pos : constant Integer := TSD (Obj_Tag).Idepth - TSD (Typ_Tag).Idepth; |
| begin |
| return Pos >= 0 and then TSD (Obj_Tag).Ancestor_Tags (Pos) = Typ_Tag; |
| end CPP_CW_Membership; |
| |
| --------------------------- |
| -- CPP_Get_Expanded_Name -- |
| --------------------------- |
| |
| function CPP_Get_Expanded_Name (T : Vtable_Ptr) return Address is |
| begin |
| return To_Address (TSD (T).Expanded_Name); |
| end CPP_Get_Expanded_Name; |
| |
| -------------------------- |
| -- CPP_Get_External_Tag -- |
| -------------------------- |
| |
| function CPP_Get_External_Tag (T : Vtable_Ptr) return Address is |
| begin |
| return To_Address (TSD (T).External_Tag); |
| end CPP_Get_External_Tag; |
| |
| ------------------------------- |
| -- CPP_Get_Inheritance_Depth -- |
| ------------------------------- |
| |
| function CPP_Get_Inheritance_Depth (T : Vtable_Ptr) return Natural is |
| begin |
| return TSD (T).Idepth; |
| end CPP_Get_Inheritance_Depth; |
| |
| ------------------------- |
| -- CPP_Get_Prim_Op_Address -- |
| ------------------------- |
| |
| function CPP_Get_Prim_Op_Address |
| (T : Vtable_Ptr; |
| Position : Positive) return Address |
| is |
| begin |
| return T.Prims_Ptr (Position).Pfn; |
| end CPP_Get_Prim_Op_Address; |
| |
| ----------------------- |
| -- CPP_Get_RC_Offset -- |
| ----------------------- |
| |
| function CPP_Get_RC_Offset (T : Vtable_Ptr) return SSE.Storage_Offset is |
| pragma Warnings (Off, T); |
| begin |
| return 0; |
| end CPP_Get_RC_Offset; |
| |
| ------------------------------- |
| -- CPP_Get_Remotely_Callable -- |
| ------------------------------- |
| |
| function CPP_Get_Remotely_Callable (T : Vtable_Ptr) return Boolean is |
| pragma Warnings (Off, T); |
| begin |
| return True; |
| end CPP_Get_Remotely_Callable; |
| |
| ----------------- |
| -- CPP_Get_TSD -- |
| ----------------- |
| |
| function CPP_Get_TSD (T : Vtable_Ptr) return Address is |
| use type System.Storage_Elements.Storage_Offset; |
| TSD_Ptr : constant Addr_Ptr := |
| To_Addr_Ptr (To_Address (T) - CPP_DT_Typeinfo_Ptr_Size); |
| begin |
| return TSD_Ptr.all; |
| end CPP_Get_TSD; |
| |
| -------------------- |
| -- CPP_Inherit_DT -- |
| -------------------- |
| |
| procedure CPP_Inherit_DT |
| (Old_T : Vtable_Ptr; |
| New_T : Vtable_Ptr; |
| Entry_Count : Natural) |
| is |
| begin |
| if Old_T /= null then |
| New_T.Prims_Ptr (1 .. Entry_Count) |
| := Old_T.Prims_Ptr (1 .. Entry_Count); |
| end if; |
| end CPP_Inherit_DT; |
| |
| --------------------- |
| -- CPP_Inherit_TSD -- |
| --------------------- |
| |
| procedure CPP_Inherit_TSD |
| (Old_TSD : Address; |
| New_Tag : Vtable_Ptr) |
| is |
| Old_TSD_Ptr : constant Type_Specific_Data_Ptr := |
| To_Type_Specific_Data_Ptr (Old_TSD); |
| |
| New_TSD_Ptr : constant Type_Specific_Data_Ptr := |
| TSD (New_Tag); |
| |
| begin |
| if Old_TSD_Ptr /= null then |
| New_TSD_Ptr.Idepth := Old_TSD_Ptr.Idepth + 1; |
| New_TSD_Ptr.Ancestor_Tags (1 .. New_TSD_Ptr.Idepth) := |
| Old_TSD_Ptr.Ancestor_Tags (0 .. Old_TSD_Ptr.Idepth); |
| else |
| New_TSD_Ptr.Idepth := 0; |
| end if; |
| |
| New_TSD_Ptr.Ancestor_Tags (0) := New_Tag; |
| end CPP_Inherit_TSD; |
| |
| --------------------------- |
| -- CPP_Set_Expanded_Name -- |
| --------------------------- |
| |
| procedure CPP_Set_Expanded_Name (T : Vtable_Ptr; Value : Address) is |
| begin |
| TSD (T).Expanded_Name := To_Cstring_Ptr (Value); |
| end CPP_Set_Expanded_Name; |
| |
| -------------------------- |
| -- CPP_Set_External_Tag -- |
| -------------------------- |
| |
| procedure CPP_Set_External_Tag (T : Vtable_Ptr; Value : Address) is |
| begin |
| TSD (T).External_Tag := To_Cstring_Ptr (Value); |
| end CPP_Set_External_Tag; |
| |
| ------------------------------- |
| -- CPP_Set_Inheritance_Depth -- |
| ------------------------------- |
| |
| procedure CPP_Set_Inheritance_Depth |
| (T : Vtable_Ptr; |
| Value : Natural) |
| is |
| begin |
| TSD (T).Idepth := Value; |
| end CPP_Set_Inheritance_Depth; |
| |
| ----------------------------- |
| -- CPP_Set_Prim_Op_Address -- |
| ----------------------------- |
| |
| procedure CPP_Set_Prim_Op_Address |
| (T : Vtable_Ptr; |
| Position : Positive; |
| Value : Address) |
| is |
| begin |
| T.Prims_Ptr (Position).Pfn := Value; |
| end CPP_Set_Prim_Op_Address; |
| |
| ----------------------- |
| -- CPP_Set_RC_Offset -- |
| ----------------------- |
| |
| procedure CPP_Set_RC_Offset (T : Vtable_Ptr; Value : SSE.Storage_Offset) is |
| pragma Warnings (Off, T); |
| pragma Warnings (Off, Value); |
| begin |
| null; |
| end CPP_Set_RC_Offset; |
| |
| ------------------------------- |
| -- CPP_Set_Remotely_Callable -- |
| ------------------------------- |
| |
| procedure CPP_Set_Remotely_Callable (T : Vtable_Ptr; Value : Boolean) is |
| pragma Warnings (Off, T); |
| pragma Warnings (Off, Value); |
| begin |
| null; |
| end CPP_Set_Remotely_Callable; |
| |
| ----------------- |
| -- CPP_Set_TSD -- |
| ----------------- |
| |
| procedure CPP_Set_TSD (T : Vtable_Ptr; Value : Address) is |
| use type System.Storage_Elements.Storage_Offset; |
| TSD_Ptr : constant Addr_Ptr := |
| To_Addr_Ptr (To_Address (T) - CPP_DT_Typeinfo_Ptr_Size); |
| begin |
| TSD_Ptr.all := Value; |
| end CPP_Set_TSD; |
| |
| -------------------- |
| -- Displaced_This -- |
| -------------------- |
| |
| function Displaced_This |
| (Current_This : System.Address; |
| Vptr : Vtable_Ptr; |
| Position : Positive) |
| return System.Address |
| is |
| pragma Warnings (Off, Vptr); |
| pragma Warnings (Off, Position); |
| |
| begin |
| return Current_This; |
| |
| -- why is the following here commented out ??? |
| -- + Storage_Offset (Vptr.Prims_Ptr (Position).Delta1); |
| end Displaced_This; |
| |
| ------------------- |
| -- Expanded_Name -- |
| ------------------- |
| |
| function Expanded_Name (T : Vtable_Ptr) return String is |
| Result : constant Cstring_Ptr := TSD (T).Expanded_Name; |
| begin |
| return Result (1 .. Length (Result)); |
| end Expanded_Name; |
| |
| ------------------ |
| -- External_Tag -- |
| ------------------ |
| |
| function External_Tag (T : Vtable_Ptr) return String is |
| Result : constant Cstring_Ptr := TSD (T).External_Tag; |
| begin |
| return Result (1 .. Length (Result)); |
| end External_Tag; |
| |
| ------------ |
| -- Length -- |
| ------------ |
| |
| function Length (Str : Cstring_Ptr) return Natural is |
| Len : Integer := 1; |
| |
| begin |
| while Str (Len) /= ASCII.Nul loop |
| Len := Len + 1; |
| end loop; |
| |
| return Len - 1; |
| end Length; |
| |
| ------------------ |
| -- Offset_To_Top -- |
| ------------------ |
| |
| function Offset_To_Top (T : Vtable_Ptr) return Integer is |
| use type System.Storage_Elements.Storage_Offset; |
| |
| TSD_Ptr : constant Int_Ptr |
| := To_Int_Ptr (To_Address (T) - CPP_DT_Prologue_Size); |
| begin |
| return TSD_Ptr.all; |
| end Offset_To_Top; |
| |
| ------------------ |
| -- Typeinfo_Ptr -- |
| ------------------ |
| |
| function Typeinfo_Ptr (T : Vtable_Ptr) return System.Address is |
| use type System.Storage_Elements.Storage_Offset; |
| TSD_Ptr : constant Addr_Ptr := |
| To_Addr_Ptr (To_Address (T) - CPP_DT_Typeinfo_Ptr_Size); |
| begin |
| return TSD_Ptr.all; |
| end Typeinfo_Ptr; |
| |
| --------- |
| -- TSD -- |
| --------- |
| |
| function TSD (T : Vtable_Ptr) return Type_Specific_Data_Ptr is |
| begin |
| return To_Type_Specific_Data_Ptr (CPP_Get_TSD (T)); |
| end TSD; |
| |
| end Interfaces.CPP; |
