227 lines
6.9 KiB
C
227 lines
6.9 KiB
C
/*
|
|
* $Id$
|
|
*
|
|
Harbour Project source code
|
|
|
|
This file is a part of Harbour Runtime Library and it contains code
|
|
that handles codeblocks
|
|
|
|
Copyright (C) 1999 Ryszard Glab
|
|
www - http://www.harbour-project.org
|
|
|
|
This program is free software; you can redistribute it and/or modify
|
|
it under the terms of the GNU General Public License as published by
|
|
the Free Software Foundation; either version 2 of the License, or
|
|
(at your option) any later version, with one exception:
|
|
|
|
The exception is that if you link the Harbour Runtime Library (HRL)
|
|
and/or the Harbour Virtual Machine (HVM) with other files to produce
|
|
an executable, this does not by itself cause the resulting executable
|
|
to be covered by the GNU General Public License. Your use of that
|
|
executable is in no way restricted on account of linking the HRL
|
|
and/or HVM code into it.
|
|
|
|
This program 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 General Public License for more details.
|
|
|
|
You should have received a copy of the GNU General Public License
|
|
along with this program; if not, write to the Free Software
|
|
Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA (or visit
|
|
their web site at http://www.gnu.org/).
|
|
|
|
*/
|
|
|
|
/* The Harbour implementation of codeblocks */
|
|
|
|
#include "extend.h"
|
|
#include <string.h>
|
|
|
|
/* functions for memvar variables
|
|
*/
|
|
HB_HANDLE hb_MemvarValueNew( PHB_ITEM, int );
|
|
void hb_MemvarValueIncRef( HB_HANDLE );
|
|
void hb_MemvarValueDecRef( HB_HANDLE );
|
|
HB_VALUE_PTR * hb_MemvarValueBaseAddress( void );
|
|
|
|
/* Uncomment this to trace codeblocks activity
|
|
#define CODEBLOCKDEBUG
|
|
*/
|
|
|
|
/* Creates the codeblock structure
|
|
*
|
|
* pBuffer -> the buffer with pcodes (without HB_P_PUSHBLOCK)
|
|
* wLocals -> number of local variables referenced in a codeblock
|
|
* pLocalPosTable -> a table with positions on eval stack for referenced variables
|
|
* pSymbols -> a pointer to the module symbol table
|
|
*
|
|
* Note: pLocalPosTable cannot be used if wLocals is ZERO
|
|
*
|
|
*/
|
|
HB_CODEBLOCK_PTR hb_CodeblockNew( BYTE * pBuffer,
|
|
WORD wLocals,
|
|
WORD *pLocalPosTable,
|
|
PSYMBOL pSymbols )
|
|
{
|
|
HB_CODEBLOCK_PTR pCBlock;
|
|
|
|
pCBlock =( HB_CODEBLOCK_PTR ) hb_xgrab( sizeof(HB_CODEBLOCK) );
|
|
|
|
/* Store the number of referenced local variables
|
|
*/
|
|
pCBlock->wLocals =wLocals;
|
|
if( wLocals )
|
|
{
|
|
/* NOTE: if a codeblock will be created by macro compiler then
|
|
* wLocal have to be ZERO
|
|
*/
|
|
WORD w = 0;
|
|
PHB_ITEM pLocal;
|
|
HB_HANDLE hMemvar;
|
|
|
|
/* Create a table that will store the values of local variables
|
|
* accessed in a codeblock
|
|
*/
|
|
pCBlock->pLocals =(PHB_ITEM) hb_xgrab( wLocals * sizeof(HB_ITEM) );
|
|
|
|
while( wLocals-- )
|
|
{
|
|
/* Swap the current value of local variable with the reference to this
|
|
* value.
|
|
* TODO: If Harbour will support threads in the future then we need
|
|
* to implement some kind of semaphores here.
|
|
*/
|
|
pLocal =stack.pBase +1 +(*pLocalPosTable++);
|
|
|
|
if( ! IS_MEMVAR( pLocal ) )
|
|
{
|
|
/* Change the value only if this variable is not referenced
|
|
* by another codeblock yet.
|
|
* In this case we have to copy the current value to a global memory
|
|
* pool so it can be shared by codeblocks
|
|
*/
|
|
|
|
hMemvar =hb_MemvarValueNew( pLocal, FALSE );
|
|
|
|
pLocal->type =IT_BYREF | IT_MEMVAR;
|
|
pLocal->item.asMemvar.itemsbase =hb_MemvarValueBaseAddress();
|
|
pLocal->item.asMemvar.offset =0;
|
|
pLocal->item.asMemvar.value =hMemvar;
|
|
|
|
hb_MemvarValueIncRef( pLocal->item.asMemvar.value );
|
|
memcpy( pCBlock->pLocals + w, pLocal, sizeof(HB_ITEM) );
|
|
}
|
|
else
|
|
{
|
|
/* This variable is already detached (by another codeblock)
|
|
* - copy the reference to a value
|
|
*/
|
|
/* Increment the reference counter so this value will not be
|
|
* released if other codeblock will be deleted
|
|
*/
|
|
hb_MemvarValueIncRef( pLocal->item.asMemvar.value );
|
|
memcpy( pCBlock->pLocals + w, pLocal, sizeof(HB_ITEM) );
|
|
|
|
}
|
|
|
|
++w;
|
|
}
|
|
}
|
|
else
|
|
pCBlock->pLocals =NULL;
|
|
|
|
/*
|
|
* The codeblock pcode is stored in static segment.
|
|
* The only allowed operation on a codeblock is evaluating it then
|
|
* there is no need to duplicate its pcode - just store the pointer to it
|
|
*/
|
|
pCBlock->pCode = pBuffer;
|
|
|
|
pCBlock->pSymbols =pSymbols;
|
|
pCBlock->lCounter =1;
|
|
|
|
#ifdef CODEBLOCKDEBUG
|
|
printf( "\ncodeblock created (%li) %lx", pCBlock->lCounter, pCBlock );
|
|
#endif
|
|
return pCBlock;
|
|
}
|
|
|
|
/* Delete a codeblock
|
|
*/
|
|
void hb_CodeblockDelete( HB_ITEM_PTR pItem )
|
|
{
|
|
HB_CODEBLOCK_PTR pCBlock = pItem->item.asBlock.value;
|
|
#ifdef CODEBLOCKDEBUG
|
|
printf( "\ndelete a codeblock (%li) %lx", pCBlock->lCounter, pCBlock );
|
|
#endif
|
|
if( --pCBlock->lCounter == 0 )
|
|
{
|
|
/* free space allocated for local variables
|
|
*/
|
|
if( pCBlock->pLocals )
|
|
{
|
|
WORD w = 0;
|
|
while( w < pCBlock->wLocals )
|
|
{
|
|
hb_MemvarValueDecRef( pCBlock->pLocals[ w ].item.asMemvar.value );
|
|
++w;
|
|
}
|
|
hb_xfree( pCBlock->pLocals );
|
|
}
|
|
|
|
/* free space allocated for a CODEBLOCK structure
|
|
*/
|
|
hb_xfree( pCBlock );
|
|
#ifdef CODEBLOCKDEBUG
|
|
printf( "\ncodeblock deleted (%li) %lx", pCBlock->lCounter, pCBlock );
|
|
#endif
|
|
}
|
|
}
|
|
|
|
/* Evaluate passed codeblock
|
|
* Before evaluation we have to switch to a static variable base that
|
|
* was defined when the codeblock was created.
|
|
* (The codeblock can only see the static variables defined in a module
|
|
* where the codeblock was created)
|
|
*/
|
|
void hb_CodeblockEvaluate( HB_ITEM_PTR pItem )
|
|
{
|
|
int iStatics = stack.iStatics;
|
|
|
|
stack.iStatics = pItem->item.asBlock.statics;
|
|
VirtualMachine( pItem->item.asBlock.value->pCode, pItem->item.asBlock.value->pSymbols );
|
|
stack.iStatics = iStatics;
|
|
}
|
|
|
|
/* Get local variable referenced in a codeblock
|
|
*/
|
|
PHB_ITEM hb_CodeblockGetVar( PHB_ITEM pItem, LONG iItemPos )
|
|
{
|
|
HB_CODEBLOCK_PTR pCBlock = pItem->item.asBlock.value;
|
|
/* local variables accessed in a codeblock are always stored as reference */
|
|
return hb_itemUnRef( pCBlock->pLocals -iItemPos -1 );
|
|
}
|
|
|
|
/* Get local variable passed by reference
|
|
*/
|
|
PHB_ITEM hb_CodeblockGetRef( PHB_ITEM pItem, PHB_ITEM pRefer )
|
|
{
|
|
HB_CODEBLOCK_PTR pCBlock = pItem->item.asBlock.value;
|
|
|
|
return pCBlock->pLocals -pRefer->item.asRefer.value -1;
|
|
}
|
|
|
|
/* Copy the codeblock
|
|
* TODO: check if such simple pointer coping will allow to evaluate
|
|
* codeblocks recursively
|
|
*/
|
|
void hb_CodeblockCopy( PHB_ITEM pDest, PHB_ITEM pSource )
|
|
{
|
|
pDest->item.asBlock.value =pSource->item.asBlock.value;
|
|
pDest->item.asBlock.value->lCounter++;
|
|
#ifdef CODEBLOCKDEBUG
|
|
printf( "\ncopy a codeblock (%li) %lx", pSource->item.asBlock.value->lCounter, pSource->item.asBlock.value );
|
|
#endif
|
|
}
|