Files
harbour-core/harbour/include/hbexpra.c
2000-03-20 11:52:15 +00:00

587 lines
19 KiB
C

/*
* $Id$
*/
/*
* Harbour Project source code:
* Compiler Expression Optimizer
*
* Copyright 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/).
*
*/
/* TOFIX: Split the code, since MSC8 can't compile it, even in Huge model. */
/* TODO:
* - Correct post- and pre- operations to correctly handle the following code
* a[ i++ ]++
* Notice: in current implementation (an in Clipper too) 'i++' is evaluated
* two times! This causes that the new value (after incrementation) is
* stored in next element of the array.
*/
#include <math.h>
#include "hbcomp.h"
/* memory allocation
*/
#define HB_XGRAB( size ) hb_xgrab( (size) )
#define HB_XFREE( pPtr ) hb_xfree( (void *)(pPtr) )
/* Table with operators precedence
* NOTE:
* HB_ET_NIL is used for an ordinary values and post- operators
* HB_ET_NONE is used for invalid syntax, e.g. var := var1 += 2
*/
static BYTE s_PrecedTable[] = {
HB_ET_NIL, /* HB_ET_NONE = 0, */
HB_ET_NIL, /* HB_ET_NIL, */
HB_ET_NIL, /* HB_ET_NUMERIC, */
HB_ET_NIL, /* HB_ET_STRING, */
HB_ET_NIL, /* HB_ET_CODEBLOCK, */
HB_ET_NIL, /* HB_ET_LOGICAL, */
HB_ET_NIL, /* HB_ET_SELF, */
HB_ET_NIL, /* HB_ET_ARRAY, */
HB_ET_NIL, /* HB_ET_VARREF, */
HB_ET_NIL, /* HB_ET_FUNREF, */
HB_ET_NIL, /* HB_ET_IIF, */
HB_ET_NIL, /* HB_ET_LIST, */
HB_ET_NIL, /* HB_ET_ARGLIST, */
HB_ET_NIL, /* HB_ET_ARRAYAT, */
HB_ET_NIL, /* HB_ET_MACRO, */
HB_ET_NIL, /* HB_ET_FUNCALL, */
HB_ET_NIL, /* HB_ET_ALIASVAR, */
HB_ET_NIL, /* HB_ET_ALIASEXPR, */
HB_ET_NIL, /* HB_ET_SEND, */
HB_ET_NIL, /* HB_ET_FUNNAME, */
HB_ET_NIL, /* HB_ET_ALIAS, */
HB_ET_NIL, /* HB_ET_RTVARIABLE, */
HB_ET_NIL, /* HB_ET_VARIABLE, */
HB_ET_NIL, /* HB_EO_POSTINC, post-operators */
HB_ET_NIL, /* HB_EO_POSTDEC, */
HB_ET_NONE, /* HB_EO_ASSIGN, assigments */
HB_ET_NONE, /* HB_EO_PLUSEQ, Invalid syntax */
HB_ET_NONE, /* HB_EO_MINUSEQ, */
HB_ET_NONE, /* HB_EO_MULTEQ, */
HB_ET_NONE, /* HB_EO_DIVEQ, */
HB_ET_NONE, /* HB_EO_MODEQ, */
HB_ET_NONE, /* HB_EO_EXPEQ, */
HB_EO_OR, /* HB_EO_OR, logical operators */
HB_EO_AND, /* HB_EO_AND, */
HB_ET_NIL, /* HB_EO_NOT, */
HB_EO_EQUAL, /* HB_EO_EQUAL, relational operators */
HB_EO_EQUAL, /* HB_EO_EQ, */
HB_EO_EQUAL, /* HB_EO_LT, */
HB_EO_EQUAL, /* HB_EO_GT, */
HB_EO_EQUAL, /* HB_EO_LE, */
HB_EO_EQUAL, /* HB_EO_GE, */
HB_EO_EQUAL, /* HB_EO_NE, */
HB_EO_EQUAL, /* HB_EO_IN, */
HB_EO_PLUS, /* HB_EO_PLUS, addition */
HB_EO_PLUS, /* HB_EO_MINUS, */
HB_EO_MULT, /* HB_EO_MULT, multiple */
HB_EO_MULT, /* HB_EO_DIV, */
HB_EO_MULT, /* HB_EO_MOD, */
HB_EO_POWER, /* HB_EO_POWER, */
HB_ET_NIL, /* HB_EO_NEGATE, sign operator */
HB_ET_NIL, /* HB_EO_PREINC, */
HB_ET_NIL /* HB_EO_PREDEC, pre-operators */
};
static HB_CBVAR_PTR hb_compExprCBVarNew( char *, BYTE );
/* ************************************************************************ */
/* Delete all components and delete self
*/
#if defined( HB_MACRO_SUPPORT )
void hb_compExprDelete( HB_EXPR_PTR pExpr, HB_MACRO_DECL )
#else
void hb_compExprDelete( HB_EXPR_PTR pExpr )
#endif
{
HB_TRACE(HB_TR_DEBUG, ("hb_compExprDelete()"));
HB_EXPR_USE( pExpr, HB_EA_DELETE );
HB_XFREE( pExpr );
}
/* Delete all components and delete self
*/
void hb_compExprFree( HB_EXPR_PTR pExpr, HB_MACRO_DECL )
{
HB_TRACE(HB_TR_DEBUG, ("hb_compExprFree()"));
HB_EXPR_USE( pExpr, HB_EA_DELETE );
HB_XFREE( pExpr );
HB_SYMBOL_UNUSED( HB_MACRO_VARNAME );
}
void hb_compExprErrorType( HB_EXPR_PTR pExpr, HB_MACRO_DECL )
{
HB_TRACE(HB_TR_DEBUG, ("hb_compExprErrorType()"));
hb_compErrorType( pExpr );
HB_SYMBOL_UNUSED( pExpr );
HB_SYMBOL_UNUSED( HB_MACRO_VARNAME );
}
/* Add a new local variable declaration
*/
#ifdef HB_MACRO_SUPPORT
HB_EXPR_PTR hb_compExprCBVarAdd( HB_EXPR_PTR pCB, char * szVarName, HB_MACRO_DECL )
#else
HB_EXPR_PTR hb_compExprCBVarAdd( HB_EXPR_PTR pCB, char * szVarName, BYTE bType )
#endif
{
HB_CBVAR_PTR pVar;
HB_TRACE(HB_TR_DEBUG, ("hb_compExprCBVarAdd(%s)", szVarName));
if( pCB->value.asList.pIndex )
{
/* add it to the end of the list
*/
pVar = ( HB_CBVAR_PTR ) pCB->value.asList.pIndex;
while( pVar )
{
if( strcmp( szVarName, pVar->szName ) == 0 )
hb_compErrorDuplVar( szVarName );
if( pVar->pNext )
pVar = pVar->pNext;
else
{
#ifdef HB_MACRO_SUPPORT
pVar->pNext = hb_compExprCBVarNew( szVarName, ' ' );
#else
pVar->pNext = hb_compExprCBVarNew( szVarName, bType );
#endif
pVar = NULL;
}
}
}
else
#ifdef HB_MACRO_SUPPORT
pCB->value.asList.pIndex = ( HB_EXPR_PTR ) hb_compExprCBVarNew( szVarName, ' ' );
#else
pCB->value.asList.pIndex = ( HB_EXPR_PTR ) hb_compExprCBVarNew( szVarName, bType );
#endif
return pCB;
}
/* Create a new IIF() expression or set arguments
*
* pIIF is a list of three expressions
*/
HB_EXPR_PTR hb_compExprNewIIF( HB_EXPR_PTR pExpr )
{
#ifndef HB_MACRO_SUPPORT
HB_EXPR_PTR pTmp;
pExpr->ExprType = HB_ET_IIF;
pTmp = pExpr->value.asList.pExprList; /* get first expression */
if( pTmp->ExprType == HB_ET_NONE )
{
/* there is no conditional expression e.g. IIF( , true, false )
*/
hb_compErrorSyntax( pExpr );
}
#else
pExpr->ExprType = HB_ET_IIF;
#endif
return pExpr;
}
/* Create function call
*/
#ifdef HB_MACRO_SUPPORT
HB_EXPR_PTR hb_compExprNewFunCall( HB_EXPR_PTR pName, HB_EXPR_PTR pParms, HB_MACRO_DECL )
#else
HB_EXPR_PTR hb_compExprNewFunCall( HB_EXPR_PTR pName, HB_EXPR_PTR pParms )
#endif
{
HB_EXPR_PTR pExpr = NULL;
if( pName->ExprType == HB_ET_FUNNAME )
{
/* The name of a function is specified at compile time
* e.g. MyFunc()
*
* NOTE: 'pName' can be a macro expression that will be resolved
* at runtime - in this case pName is an expression of HB_ET_MACRO type
* e.g. &MyVar()
*/
int iCount;
HB_TRACE(HB_TR_DEBUG, ("hb_compExprNewFunCall(%s)", pName->value.asSymbol));
if( pParms )
{
iCount = hb_compExprListLen( pParms );
/* Check the special case when no parameters are passed - in this case
* pParms is an expression of type HB_ET_NONE and we shouldn't
* replace it with NIL value
*/
if( iCount == 1 && pParms->value.asList.pExprList->ExprType == HB_ET_NONE )
--iCount;
}
else
iCount = 0;
#ifndef HB_MACRO_SUPPORT
hb_compFunCallCheck( pName->value.asSymbol, iCount );
#endif
/* TODO: AT() (also done by Clipper, already mentioned)
LEN() (also done by Clipper)
ASC() (not done by Clipper)
EMPTY() (not done by Clipper) */
if( ( strcmp( "CHR", pName->value.asSymbol ) == 0 ) && iCount )
{
/* try to change it into a string */
HB_EXPR_PTR pArg = pParms->value.asList.pExprList;
if( pArg->ExprType == HB_ET_NUMERIC )
{
/* NOTE: CA-Cl*pper's compiler optimizer will be wrong for those
CHR() cases where the passed parameter is a constant which
can be divided by 256 but it's not zero, in this case it
will return an empty string instead of a Chr(0). [vszakats] */
pExpr = hb_compExprNew( HB_ET_STRING );
pExpr->ValType = HB_EV_STRING;
if( pArg->value.asNum.NumType == HB_ET_LONG )
{
if( ( pArg->value.asNum.lVal % 256 ) == 0 && pArg->value.asNum.lVal != 0 )
{
pExpr->value.asString = ( char * ) HB_XGRAB( 1 );
pExpr->value.asString[ 0 ] = '\0';
pExpr->ulLength = 0;
}
else
{
pExpr->value.asString = ( char * ) HB_XGRAB( 2 );
pExpr->value.asString[ 0 ] = ( pArg->value.asNum.lVal % 256 );
pExpr->value.asString[ 1 ] = '\0';
pExpr->ulLength = 1;
}
}
else
{
pExpr->value.asString = ( char * ) HB_XGRAB( 2 );
pExpr->value.asString[ 0 ] = ( ( long ) pArg->value.asNum.dVal % 256 );
pExpr->value.asString[ 1 ] = '\0';
pExpr->ulLength = 1;
}
HB_EXPR_PCODE1( hb_compExprDelete, pParms );
HB_EXPR_PCODE1( hb_compExprDelete, pName );
}
}
}
else if( pName->ExprType == HB_ET_MACRO )
{
/* Signal that macro compiler have to generate a pcode that will
* return function name as symbol instead of usual value
*/
pName->value.asMacro.SubType = HB_ET_MACRO_SYMBOL;
HB_TRACE(HB_TR_DEBUG, ("hb_compExprNewFunCall(&)"));
}
if( pExpr == NULL )
{
pExpr = hb_compExprNew( HB_ET_FUNCALL );
pExpr->value.asFunCall.pParms = pParms;
pExpr->value.asFunCall.pFunName = pName;
}
return pExpr;
}
/* Creates new array access expression
* pArray[ pIndex ]
* NOTE: In case of multiple indexes it is called recursively
* array[ idx1, idx2 ] => ( array[ idx1 ] )[ idx2 ]
*/
#ifdef HB_MACRO_SUPPORT
HB_EXPR_PTR hb_compExprNewArrayAt( HB_EXPR_PTR pArray, HB_EXPR_PTR pIndex, HB_MACRO_DECL )
#else
HB_EXPR_PTR hb_compExprNewArrayAt( HB_EXPR_PTR pArray, HB_EXPR_PTR pIndex )
#endif
{
HB_EXPR_PTR pExpr;
HB_TRACE(HB_TR_DEBUG, ("hb_compExprNewArrayAt()"));
pExpr = hb_compExprNew( HB_ET_ARRAYAT );
/* Check if this expression can be indexed */
HB_EXPR_USE( pArray, HB_EA_ARRAY_AT );
/* Check if this expression can be an index */
HB_EXPR_USE( pIndex, HB_EA_ARRAY_INDEX );
pExpr->value.asList.pExprList = pArray;
pExpr->value.asList.pIndex = pIndex;
return pExpr;
}
/* ************************************************************************* */
#ifndef HB_MACRO_SUPPORT
static void hb_compExprCheckStaticInitializers( HB_EXPR_PTR pLeftExpr, HB_EXPR_PTR pRightExpr )
{
HB_EXPR_PTR pElem = pRightExpr->value.asList.pExprList;
HB_EXPR_PTR pNext;
HB_EXPR_PTR * pPrev;
pPrev = &pRightExpr->value.asList.pExprList;
while( pElem )
{
/* NOTE: During reduction the expression can be replaced by the
* new one - this will break the linked list of expressions.
* (classical case of replacing an item in a linked list)
*/
pNext = pElem->pNext; /* store next expression in case the current will be reduced */
pElem = hb_compExprListStrip( HB_EXPR_USE( pElem, HB_EA_REDUCE ), HB_MACRO_PARAM );
if( pElem->ExprType > HB_ET_FUNREF )
hb_compErrorStatic( pLeftExpr->value.asSymbol, pElem );
*pPrev = pElem; /* store a new expression into the previous one */
pElem->pNext = pNext; /* restore the link to next expression */
pPrev = &pElem->pNext;
pElem = pNext;
}
}
/* It initializes static variable.
* It is called in the following context:
* STATIC sVar := expression
*
* pLeftExpr - is a variable name
* pRightExpr - can be an expression of any type
*/
HB_EXPR_PTR hb_compExprAssignStatic( HB_EXPR_PTR pLeftExpr, HB_EXPR_PTR pRightExpr )
{
HB_EXPR_PTR pExpr;
HB_TRACE(HB_TR_DEBUG, ("hb_compExprAssignStatic()"));
pExpr = hb_compExprNew( HB_EO_ASSIGN );
pExpr->value.asOperator.pLeft = pLeftExpr;
/* Try to reduce the assigned value */
pRightExpr = hb_compExprListStrip( HB_EXPR_USE( pRightExpr, HB_EA_REDUCE ), HB_MACRO_PARAM );
pExpr->value.asOperator.pRight = pRightExpr;
if( pRightExpr->ExprType == HB_ET_ARGLIST )
{
/* HB_ET_ARGLIST is used in case of STATIC var[dim1, dim2, dimN]
* was used - we have to check if all array dimensions are
* constant values
*/
hb_compExprCheckStaticInitializers( pLeftExpr, pRightExpr );
}
else if( pRightExpr->ExprType > HB_ET_FUNREF )
{
/* Illegal initializer for static variable (not a constant value)
*/
hb_compErrorStatic( pLeftExpr->value.asSymbol, pRightExpr );
}
else if( pRightExpr->ExprType == HB_ET_ARRAY )
{
/* { elem1, elem2, elemN } was used as initializer
* Scan an array for illegal initializers.
* An array item have to be a const value too.
*/
hb_compExprCheckStaticInitializers( pLeftExpr, pRightExpr );
}
return pExpr;
}
#endif
/* Sets the argument of an operation found previously
*/
#ifdef HB_MACRO_SUPPORT
HB_EXPR_PTR hb_compExprSetOperand( HB_EXPR_PTR pExpr, HB_EXPR_PTR pItem, HB_MACRO_DECL )
#else
HB_EXPR_PTR hb_compExprSetOperand( HB_EXPR_PTR pExpr, HB_EXPR_PTR pItem )
#endif
{
BYTE ucRight;
ucRight = s_PrecedTable[ pItem->ExprType ];
if( ucRight == HB_ET_NIL )
{
/* the right side of an operator is an ordinary value
* e.g. a := 1
*/
pExpr->value.asOperator.pRight = pItem;
}
else if( ucRight == HB_ET_NONE )
{
/* the right side of an operator is an invalid expression
* e.g.
* a := 1 + b:=2
* a := 1 + b += 2
*/
hb_compErrorSyntax( pItem );
}
else
{
/* the right side of an operator is an expression with other operator
* e.g. a := 2 + b * 3
* We have to set the proper order of evaluation using
* precedence rules
*/
BYTE ucLeft = s_PrecedTable[ pExpr->ExprType ];
if( ucLeft >= ucRight )
{
/* Left operator has the same or lower precedence then the right one
* e.g. a * b + c
* pItem -> b + c -> L=b R=c O=+
* pExpr -> a * -> l=a r= o=*
*
* -> (a * b) + c -> Lelf=(a * b) Right=c Oper=+
* Left := l (o) L
* Right := R
* Oper := O
*/
#ifdef HB_MACRO_SUPPORT
pItem->value.asOperator.pLeft = hb_compExprSetOperand( pExpr, pItem->value.asOperator.pLeft, HB_MACRO_PARAM );
#else
pItem->value.asOperator.pLeft = hb_compExprSetOperand( pExpr, pItem->value.asOperator.pLeft );
#endif
pExpr = pItem;
}
else
{
/* Left operator has a lower precedence then the right one
* e.g. a + b * c
* pItem -> b * c -> L=b R=c O=*
* pExpr -> a + -> l=a r= o=+
*
* -> a + (b * c) -> Left=a Right=(b * c) Oper=+
* Left := l
* Right := L (O) R := pItem
* Oper := o
*/
pExpr->value.asOperator.pRight = pItem;
}
}
return pExpr;
}
/* ************************************************************************* */
/* Generates pcode for inline expression used as a statement
* NOTE: It doesn't not leave any value on the eval stack
*/
#ifdef HB_MACRO_SUPPORT
HB_EXPR_PTR hb_compExprGenStatement( HB_EXPR_PTR pExpr, HB_MACRO_DECL )
#else
HB_EXPR_PTR hb_compExprGenStatement( HB_EXPR_PTR pExpr )
#endif
{
HB_TRACE(HB_TR_DEBUG, ("hb_compExprGenStatement(%i)", pExpr->ExprType));
pExpr = HB_EXPR_USE( pExpr, HB_EA_REDUCE );
HB_EXPR_USE( pExpr, HB_EA_STATEMENT );
return pExpr;
}
/* Generates pcode to push an expressions
* NOTE: It pushes a value on the stack and leaves this value on the stack
*/
#ifdef HB_MACRO_SUPPORT
HB_EXPR_PTR hb_compExprGenPush( HB_EXPR_PTR pExpr, HB_MACRO_DECL )
#else
HB_EXPR_PTR hb_compExprGenPush( HB_EXPR_PTR pExpr )
#endif
{
HB_TRACE(HB_TR_DEBUG, ("hb_compExprGenPush(%i)", pExpr->ExprType));
pExpr = HB_EXPR_USE( pExpr, HB_EA_REDUCE );
HB_EXPR_USE( pExpr, HB_EA_PUSH_PCODE );
return pExpr;
}
/* Generates pcode to pop an expressions
*/
#ifdef HB_MACRO_SUPPORT
HB_EXPR_PTR hb_compExprGenPop( HB_EXPR_PTR pExpr, HB_MACRO_DECL )
#else
HB_EXPR_PTR hb_compExprGenPop( HB_EXPR_PTR pExpr )
#endif
{
HB_TRACE(HB_TR_DEBUG, ("hb_compExprGenPop(%i)", pExpr->ExprType));
return HB_EXPR_USE( pExpr, HB_EA_POP_PCODE );
}
/* ************************************************************************* */
/* Create a new declaration for codeblock local variable
*/
static HB_CBVAR_PTR hb_compExprCBVarNew( char * szVarName, BYTE bType )
{
HB_CBVAR_PTR pVar;
HB_TRACE(HB_TR_DEBUG, ("hb_compExprCBVarNew(%s)", szVarName));
pVar = ( HB_CBVAR_PTR ) HB_XGRAB( sizeof( HB_CBVAR ) );
pVar->szName = szVarName;
pVar->bType = bType;
pVar->pNext = NULL;
return pVar;
}
/* NOTE: This deletes all linked variables
*/
void hb_compExprCBVarDel( HB_CBVAR_PTR pVars )
{
HB_CBVAR_PTR pDel;
while( pVars )
{
pDel = pVars;
pVars = pVars->pNext;
#ifdef HB_MACRO_SUPPORT
HB_XFREE( pDel->szName );
#endif
HB_XFREE( pDel );
}
}