261 lines
8.4 KiB
C
261 lines
8.4 KiB
C
/*
|
|
* $Id$
|
|
*/
|
|
|
|
/*
|
|
* Harbour Project source code:
|
|
* Codeblock runtime support
|
|
*
|
|
* Copyright 1999 Ryszard Glab <rglab@imid.med.pl>
|
|
* 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 "ctoharb.h"
|
|
#include "itemapi.h"
|
|
|
|
/* 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 uiLocals is ZERO
|
|
*
|
|
*/
|
|
HB_CODEBLOCK_PTR hb_codeblockNew( BYTE * pBuffer,
|
|
USHORT uiLocals,
|
|
USHORT * pLocalPosTable,
|
|
PHB_SYMB pSymbols )
|
|
{
|
|
HB_CODEBLOCK_PTR pCBlock;
|
|
|
|
HB_TRACE(("hb_codeblockNew(%p, %hu, %p, %p)", pBuffer, uiLocals, pLocalPosTable, pSymbols));
|
|
|
|
pCBlock = ( HB_CODEBLOCK_PTR ) hb_xgrab( sizeof( HB_CODEBLOCK ) );
|
|
|
|
/* Store the number of referenced local variables
|
|
*/
|
|
pCBlock->uiLocals = uiLocals;
|
|
if( uiLocals )
|
|
{
|
|
/* NOTE: if a codeblock will be created by macro compiler then
|
|
* uiLocal have to be ZERO
|
|
* uiLocal will be also ZERO if it is a nested codeblock
|
|
*/
|
|
USHORT ui = 1;
|
|
PHB_ITEM pLocal;
|
|
HB_HANDLE hMemvar;
|
|
|
|
/* Create a table that will store the values of local variables
|
|
* accessed in a codeblock
|
|
* The element 0 is used as the counter of references to this table
|
|
*/
|
|
pCBlock->pLocals = ( PHB_ITEM ) hb_xgrab( ( uiLocals + 1 ) * sizeof( HB_ITEM ) );
|
|
pCBlock->pLocals[ 0 ].type = IT_LONG;
|
|
pCBlock->pLocals[ 0 ].item.asLong.value = 1;
|
|
|
|
while( uiLocals-- )
|
|
{
|
|
/* 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 = hb_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 + ui, 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 + ui, pLocal, sizeof( HB_ITEM ) );
|
|
}
|
|
++ui;
|
|
}
|
|
}
|
|
else
|
|
{
|
|
/* Check if this codeblock is created during evaluation of another
|
|
* codeblock - all inner codeblocks use the local variables table
|
|
* created during creation of the outermost codeblock
|
|
*/
|
|
PHB_ITEM pLocal;
|
|
|
|
pLocal = hb_stack.pBase + 1;
|
|
if( IS_BLOCK( pLocal ) )
|
|
{
|
|
HB_CODEBLOCK_PTR pOwner = pLocal->item.asBlock.value;
|
|
|
|
pCBlock->pLocals = pOwner->pLocals;
|
|
pCBlock->uiLocals = uiLocals = pOwner->uiLocals;
|
|
if( pOwner->pLocals )
|
|
{ /* the outer codeblock have the table with local references - reuse it */
|
|
while( uiLocals )
|
|
{
|
|
hb_memvarValueIncRef( pCBlock->pLocals[ uiLocals ].item.asMemvar.value );
|
|
--uiLocals;
|
|
}
|
|
/* increment a reference counter for the table of local references
|
|
*/
|
|
pCBlock->pLocals[ 0 ].item.asLong.value++;
|
|
}
|
|
}
|
|
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->ulCounter = 1;
|
|
|
|
HB_TRACE(("codeblock created (%li) %lx", pCBlock->ulCounter, pCBlock));
|
|
|
|
return pCBlock;
|
|
}
|
|
|
|
/* Delete a codeblock
|
|
*/
|
|
void hb_codeblockDelete( HB_ITEM_PTR pItem )
|
|
{
|
|
HB_CODEBLOCK_PTR pCBlock = pItem->item.asBlock.value;
|
|
|
|
HB_TRACE(("hb_codeblockDelete(%p)", pItem));
|
|
|
|
HB_TRACE(("deleting a codeblock (%li) %lx", pCBlock->ulCounter, pCBlock));
|
|
|
|
if( --pCBlock->ulCounter == 0 )
|
|
{
|
|
/* free space allocated for local variables
|
|
*/
|
|
if( pCBlock->pLocals )
|
|
{
|
|
USHORT ui = 1;
|
|
while( ui < pCBlock->uiLocals )
|
|
{
|
|
hb_memvarValueDecRef( pCBlock->pLocals[ ui ].item.asMemvar.value );
|
|
++ui;
|
|
}
|
|
/* decrement the table reference counter and release memory if
|
|
* it was the last reference
|
|
*/
|
|
if( --pCBlock->pLocals[ 0 ].item.asLong.value == 0 )
|
|
hb_xfree( pCBlock->pLocals );
|
|
}
|
|
|
|
/* free space allocated for a CODEBLOCK structure
|
|
*/
|
|
hb_xfree( pCBlock );
|
|
|
|
HB_TRACE(("codeblock deleted (%li) %lx", pCBlock->ulCounter, pCBlock));
|
|
}
|
|
}
|
|
|
|
/* 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 = hb_stack.iStatics;
|
|
|
|
HB_TRACE(("hb_codeblockEvaluate(%p)", pItem));
|
|
|
|
hb_stack.iStatics = pItem->item.asBlock.statics;
|
|
hb_vmExecute( pItem->item.asBlock.value->pCode, pItem->item.asBlock.value->pSymbols );
|
|
hb_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;
|
|
|
|
HB_TRACE(("hb_codeblockGetVar(%p, %ld)", pItem, iItemPos));
|
|
|
|
/* local variables accessed in a codeblock are always stored as reference */
|
|
return hb_itemUnRef( pCBlock->pLocals - iItemPos );
|
|
}
|
|
|
|
/* Get local variable passed by reference
|
|
*/
|
|
PHB_ITEM hb_codeblockGetRef( PHB_ITEM pItem, PHB_ITEM pRefer )
|
|
{
|
|
HB_CODEBLOCK_PTR pCBlock = pItem->item.asBlock.value;
|
|
|
|
HB_TRACE(("hb_codeblockGetRef(%p, %p)", pItem, pRefer));
|
|
|
|
return pCBlock->pLocals - pRefer->item.asRefer.value;
|
|
}
|
|
|
|
/* 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 )
|
|
{
|
|
HB_TRACE(("hb_codeblockCopy(%p, %p)", pDest, pSource));
|
|
|
|
pDest->item.asBlock.value = pSource->item.asBlock.value;
|
|
pDest->item.asBlock.value->ulCounter++;
|
|
|
|
HB_TRACE(("copied a codeblock (%li) %lx", pSource->item.asBlock.value->ulCounter, pSource->item.asBlock.value));
|
|
}
|