{
$Id: callspec.pas,v 1.2 2002/09/07 15:06:36 peter Exp $
This unit provides compiler-independent mechanisms to call special
functions, i.e. local functions/procedures, constructors, methods,
destructors, etc. As there are no procedural variables for these
special functions, there is no Pascal way to call them directly.
Copyright (c) 1997 Matthias K"oppe <mkoeppe@csmd.cs.uni-magdeburg.de>
This library is free software; you can redistribute it and/or
modify it under the terms of the GNU Library General Public
License as published by the Free Software Foundation; either
version 2 of the License, or (at your option) any later version.
This library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Library General Public License for more details.
You should have received a copy of the GNU Library General Public
License along with this library; if not, write to the Free
Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
****************************************************************************}
unit CallSpec;
{
As of this version, the following compilers are supported. Please
port CallSpec to other compilers (including earlier versions) and
send your code to the above address.
Compiler Comments
--------------------------- -------------------------------------
Turbo Pascal 6.0
Borland/Turbo Pascal 7.0
FPC Pascal 0.99.8
}
interface
{$i platform.inc}
{
The frame pointer points to the local variables of a procedure.
Use CurrentFramePointer to address the locals of the current procedure;
use PreviousFramePointer to addess the locals of the calling procedure.
}
type
{$ifdef BIT_16}
FramePointer = Word;
{$endif}
{$ifdef BIT_32}
FramePointer = pointer;
{$endif}
function CurrentFramePointer: FramePointer;
function PreviousFramePointer: FramePointer;
{ This version of CallSpec supports four classes of special functions.
(Please write if you need other classes.)
For each, two types of argument lists are allowed:
`Void' indicates special functions with no explicit arguments.
Sample: constructor T.Init;
`Pointer' indicates special functions with one explicit pointer argument.
Sample: constructor T.Load(var S: TStream);
}
{ Constructor calls.
Ctor Pointer to the constructor.
Obj Pointer to the instance. NIL if new instance to be allocated.
VMT Pointer to the VMT (obtained by TypeOf()).
returns Pointer to the instance.
}
function CallVoidConstructor(Ctor: pointer; Obj: pointer; VMT: pointer): pointer;
function CallPointerConstructor(Ctor: pointer; Obj: pointer; VMT: pointer; Param1: pointer): pointer;
{ Method calls.
Method Pointer to the method.
Obj Pointer to the instance. NIL if new instance to be allocated.
returns Pointer to the instance.
}
function CallVoidMethod(Method: pointer; Obj: pointer): pointer;
function CallPointerMethod(Method: pointer; Obj: pointer; Param1: pointer): pointer;
{ Local-function/procedure calls.
Func Pointer to the local function (which must be far-coded).
Frame Frame pointer of the wrapping function.
}
function CallVoidLocal(Func: pointer; Frame: FramePointer): pointer;
function CallPointerLocal(Func: pointer; Frame: FramePointer; Param1: pointer): pointer;
{ Calls of functions/procedures local to methods.
Func Pointer to the local function (which must be far-coded).
Frame Frame pointer of the wrapping method.
Obj Pointer to the object that the method belongs to.
}
function CallVoidMethodLocal(Func: pointer; Frame: FramePointer; Obj: pointer): pointer;
function CallPointerMethodLocal(Func: pointer; Frame: FramePointer; Obj: pointer; Param1: pointer): pointer;
implementation
{$ifdef PPC_FPC}
{$ifdef CPUI386}
{$ASMMODE ATT}
{$endif CPUI386}
{ This indicates an FPC version which uses the same call scheme for
method-local and procedure-local procedures, but which expects the
ESI register be loaded with the Self pointer in method-local procs. }
type
VoidLocal = function(_EBP: FramePointer): pointer;
PointerLocal = function(_EBP: FramePointer; Param1: pointer): pointer;
VoidMethodLocal = function(_EBP: FRAMEPOINTER): pointer;
PointerMethodLocal = function(_EBP: FRAMEPOINTER; Param1: pointer): pointer;
VoidConstructor = function(VMT: pointer; Obj: pointer): pointer;
PointerConstructor = function(VMT: pointer; Obj: pointer; Param1: pointer): pointer;
VoidMethod = function(Obj: pointer): pointer;
PointerMethod = function(Obj: pointer; Param1: pointer): pointer;
function CallVoidConstructor(Ctor: pointer; Obj: pointer; VMT: pointer): pointer;
begin
{ load the object pointer }
{$ifdef CPUI386}
asm
movl Obj, %esi
end;
{$endif CPUI386}
{$ifdef CPU68K}
asm
move.l Obj, a5
end;
{$endif CPU68K}
CallVoidConstructor := VoidConstructor(Ctor)(VMT, Obj)
end;
function CallPointerConstructor(Ctor: pointer; Obj: pointer; VMT: pointer; Param1: pointer): pointer;
begin
{ load the object pointer }
{$ifdef CPUI386}
asm
movl Obj, %esi
end;
{$endif CPUI386}
{$ifdef CPU68K}
asm
move.l Obj, a5
end;
{$endif CPU68K}
CallPointerConstructor := PointerConstructor(Ctor)(VMT, Obj, Param1)
end;
function CallVoidMethod(Method: pointer; Obj: pointer): pointer;
begin
{ load the object pointer }
{$ifdef CPUI386}
asm
movl Obj, %esi
end;
{$endif CPUI386}
{$ifdef CPU68K}
asm
move.l Obj, a5
end;
{$endif CPU68K}
CallVoidMethod := VoidMethod(Method)(Obj)
end;
function CallPointerMethod(Method: pointer; Obj: pointer; Param1: pointer): pointer;
begin
{ load the object pointer }
{$ifdef CPUI386}
asm
movl Obj, %esi
end;
{$endif CPUI386}
{$ifdef CPU68K}
asm
move.l Obj, a5
end;
{$endif CPU68K}
CallPointerMethod := PointerMethod(Method)(Obj, Param1)
end;
function CallVoidLocal(Func: pointer; Frame: FramePointer): pointer;
begin
CallVoidLocal := VoidLocal(Func)(Frame)
end;
function CallPointerLocal(Func: pointer; Frame: FramePointer; Param1: pointer): pointer;
begin
CallPointerLocal := PointerLocal(Func)(Frame, Param1)
end;
function CallVoidMethodLocal(Func: pointer; Frame: FramePointer; Obj: pointer): pointer;
begin
{ load the object pointer }
{$ifdef CPUI386}
asm
movl Obj, %esi
end;
{$endif CPUI386}
{$ifdef CPU68K}
asm
move.l Obj, a5
end;
{$endif CPU68K}
CallVoidMethodLocal := VoidMethodLocal(Func)(Frame)
end;
function CallPointerMethodLocal(Func: pointer; Frame: FramePointer; Obj: pointer; Param1: pointer): pointer;
begin
{ load the object pointer }
{$ifdef CPUI386}
asm
movl Obj, %esi
end;
{$endif CPUI386}
{$ifdef CPU68K}
asm
move.l Obj, a5
end;
{$endif CPU68K}
CallPointerMethodLocal := PointerMethodLocal(Func)(Frame, Param1)
end;
function CurrentFramePointer: FramePointer;assembler;
{$ifdef CPUI386}
asm
movl %ebp,%eax
end ['EAX'];
{$endif CPUI386}
{$ifdef CPU68K}
asm
move.l a6, d0
end['D0'];
{$endif CPU68K}
function PreviousFramePointer: FramePointer;assembler;
{$ifdef CPUI386}
asm
movl (%ebp),%eax
end ['EAX'];
{$endif CPUI386}
{$ifdef CPU68K}
asm
move.l (a6), d0
end['D0'];
{$endif CPU68K}
{$endif PPC_FPC}
{$ifdef PPC_BP}
type
VoidConstructor = function(VmtOfs: Word; Obj: pointer): pointer;
PointerConstructor = function(Param1: pointer; VmtOfs: Word; Obj: pointer): pointer;
VoidMethod = function(Obj: pointer): pointer;
PointerMethod = function(Param1: pointer; Obj: pointer): pointer;
function CallVoidConstructor(Ctor: pointer; Obj: pointer; VMT: pointer): pointer;
begin
CallVoidConstructor := VoidConstructor(Ctor)(Ofs(VMT^), Obj)
end;
function CallPointerConstructor(Ctor: pointer; Obj: pointer; VMT: pointer; Param1: pointer): pointer;
begin
CallPointerConstructor := PointerConstructor(Ctor)(Param1, Ofs(VMT^), Obj)
end;
function CallVoidMethod(Method: pointer; Obj: pointer): pointer;
begin
CallVoidMethod := VoidMethod(Method)(Obj)
end;
function CallPointerMethod(Method: pointer; Obj: pointer; Param1: pointer): pointer;
begin
CallPointerMethod := PointerMethod(Method)(Param1, Obj)
end;
function CallVoidLocal(Func: pointer; Frame: FramePointer): pointer; assembler;
asm
{$IFDEF Windows}
MOV AX,[Frame]
AND AL,0FEH
PUSH AX
{$ELSE}
push [Frame]
{$ENDIF}
call dword ptr Func
end;
function CallPointerLocal(Func: pointer; Frame: FramePointer; Param1: pointer): pointer; assembler;
asm
mov ax, word ptr Param1
mov dx, word ptr Param1+2
push dx
push ax
{$IFDEF Windows}
MOV AX,[Frame]
AND AL,0FEH
PUSH AX
{$ELSE}
push [Frame]
{$ENDIF}
call dword ptr Func
end;
function CallVoidMethodLocal(Func: pointer; Frame: FramePointer; Obj: pointer): pointer; assembler;
asm
{$IFDEF Windows}
MOV AX,[Frame]
AND AL,0FEH
PUSH AX
{$ELSE}
push [Frame]
{$ENDIF}
call dword ptr Func
end;
function CallPointerMethodLocal(Func: pointer; Frame: FramePointer; Obj: pointer; Param1: pointer): pointer; assembler;
asm
mov ax, word ptr Param1
mov dx, word ptr Param1+2
push dx
push ax
{$IFDEF Windows}
MOV AX,[Frame]
AND AL,0FEH
PUSH AX
{$ELSE}
push [Frame]
{$ENDIF}
call dword ptr Func
end;
function CurrentFramePointer: FramePointer; assembler;
asm
mov ax, bp
end;
function PreviousFramePointer: FramePointer; assembler;
asm
mov ax, ss:[bp]
end;
{$endif PPC_BP}
end.
{
$Log: callspec.pas,v $
Revision 1.2 2002/09/07 15:06:36 peter
* old logs removed and tabs fixed
}
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