/* asmeval.c -- microsoft 80x86 assembler
**
** microsoft (r) macro assembler
** copyright (c) microsoft corp 1986. all rights reserved
**
** randy nevin
**
** 10/90 - Quick conversion to 32 bit by Jeff Spencer
*/
#include <stdio.h>
#include "asm86.h"
#include "asmfcn.h"
#include "asmexpr.h"
char parseset[] = {14,
OPUNPLUS, OPPLUS,
OPMINUS, OPUNMINUS,
OPHIGH, OPLOW,
OPDOT, OPOFFSET,
OPCOLON, OPLPAR,
OPLBRK, OPTHIS,
OPSHORT, OPPTR};
/* POPvalue pops a operand from the top of the evaluation stack
If the item is not an operand or the stack is empty, an
error is generated and a value of 0 is supplied. The operand
is returned to the caller in <valu> and is a result type
operand. The original operand will not be a result unless it
has been already used. The operand entry is destroyed and a
result operand is created for constants and symbols( which
are not record/struc names or fields ). */
/*** valerror - process error in operand entry
*
* valerror (p);
*
* Entry
* Exit
* Returns
* Calls
*/
VOID PASCAL CODESIZE
valerror (
register struct ar *p
){
DSCREC *oldlast;
/* Operand was expected */
errorc (E_OPN);
/* save expr stack */
oldlast = p->lastitem;
p->lastitem = defaultdsc ();
/* Point to rest */
p->lastitem->previtem = oldlast;
}
/*** popvalue - pop operand entry off parse stack
*
* dscrec = popvalue (p);
*
* Entry
* Exit
* Returns
* Calls
*/
DSCREC * PASCAL CODESIZE
popvalue (
register struct ar *p
){
register DSCREC *valu;
if (!p->lastitem)
valerror (p);
if (p->lastitem->itype != OPERAND)
valerror (p);
/* If not operand, insert one at LASTitem */
/* In case need to convert */
valu = p->lastitem;
/* Assume won't convert */
/* Pop operand off stack */
p->lastitem = valu->previtem;
return (valu);
}
/*** popoperator - pop next operator from stack
*
* op = popoperator (p);
*
* Entry *p = parse stack entry
* Exit
* Returns operator
* Calls
*/
UCHAR PASCAL CODESIZE
popoperator (
register struct ar *p
){
register char op;
if (!p->lastitem) {
errorc( E_OPR ); /* expected operator */
return( (char)OPPLUS ); /* use '+' as default */
}
else {
if (p->lastitem->itype != OPERATOR) {
errorc( E_OPR ); /* expected operator */
return( (char)OPPLUS ); /* use '+' as default */
}
else {
/* Return OPERATOR number */
op = p->lastitem->dsckind.opr.oidx;
/* Pop OPERATOR off stack */
itemptr = p->lastitem;
p->lastitem = p->lastitem->previtem;
return (op);
}
}
}
/* Evaluate is called to evaluate part of the expression. It is
usually called just before a lower precedence is pushed, but
also when the expression is complete and for close parens of
various kinds regadless of precedence. The amount of the
expression stack evauated depends on the caller. There are
3 cases:
1. Lower precedence OPERATOR( 3+4*5 AND 3 ). Evaluate
back until left paren or precedence<= OPERATOR. If
paren, leave on stack.
2. A paren of some kind( )>] ). Evaluate back to match-
ing paren. Leave paren off stack. If any other paren
seen, cause error.
3. End of expression( ENDexpr TRUE ). Evaluate all that
is left of expression.
*/
/*** pushpar - push paren or bracket back onto stack
*
* routine ();
*
* Entry
* Exit
* Returns
* Calls
*/
VOID PASCAL CODESIZE
pushpar (
register struct evalrec *p
){
itemptr->previtem = p->p->lastitem;
p->p->lastitem = itemptr;
/* So OPERATOR not removed */
itemptr = NULL;
}
/* EVALtop evaluates the top OPERATOR on the stack and its
operands and produces CURresult as a result. It assumes that
the stack is arranged as follows:
Operand( If not already result type, will convert )
OPERATOR( <> will cause error, [ executes as OPERATOR
( will not evaluate, but whether stays on
stack is determined by PARENflag )
Operand ( If not result, will convert. If OPERATOR is
unary, will not be looked for. Special check
for +/- used as unary. )
Any deviation from the above will cause an error to be
generated by popvalue/popoperator. */
/*** signadjust - calculate offset and sign of result and put in right operand
*
* routine ();
*
* Entry
* Exit
* Returns
* Calls
* Note Right and left operands may be switched
*/
VOID PASCAL CODESIZE
signadjust (
UCHAR minus,
register struct exprec *p
){
register struct psop *psol; /* parse stack operand structure */
register struct psop *psor; /* parse stack operand structure */
DSCREC *t;
OFFSET maxInt;
char fOverflow = FALSE;
maxInt = (fArth32)? OFFSETMAX: 0xffff;
psor = &(p->valright->dsckind.opnd);
psol = &(p->valleft->dsckind.opnd);
if (psol->s) /* arthmethic on data size item - NEAR/FAR */
errorc(E_TIL);
if (minus)
psor->dsign = !psor->dsign;
if (psol->dsegment || psol->dflag == XTERNAL ||
(M_FLTSTACK & psol->dtype)) {
/* Want to preserve Left operand */
t = p->valleft;
p->valleft = p->valright;
p->valright = t;
p->right = p->left;
p->left = p->valleft->dsckind.opnd.doffset;
psor = &(p->valright->dsckind.opnd);
psol = &(p->valleft->dsckind.opnd);
}
if (psol->dflag == UNDEFINED)
psor->dtype = M_CODE | M_FORTYPE;
if (psor->dflag == UNDEFINED && !(psol->dtype & M_PTRSIZE))
psol->dsize = 0;
if (psol->dsign == psor->dsign) {
/* Signs are same */
fOverflow = (((maxInt - p->right) + 1) == p->left);
p->right = p->right + p->left;
} else if (p->right > p->left)
/* Different signs */
p->right = p->right - p->left;
else {
p->right = p->left - p->right;
psor->dsign = !psor->dsign;
}
if (p->right == 0 && !fOverflow)
psor->dsign = FALSE;
if (psor->dsign && (psor->dtype & M_SEGRESULT))
errorc (E_OSA);
psor->doffset = p->right;
}
/*** foldsigns - force evaluating 17 bit signed values back to 16 bits
*
* routine ();
*
* Entry
* Exit
* Returns
* Calls
*/
VOID PASCAL CODESIZE
foldsigns (
register struct exprec *p
){
/* the forms inside the comments seem to be trying to manage
* things as unsigned short even though they are stored in a
* larger field--ie this would be running as a cross assembler
* from a 32 bit host to a 16 bit object. since for the 386,
* we keep all this stuff as long, this turns out to be a bad
* approach. so without completely understanding what is going
* on, I am doing a simple negate (on the OFFSET field, which
* is probably an unsigned long) rather than trying to preserve
* the odd typing of the previous version -Hans, 19/9/86 */
if (p->valright->dsckind.opnd.dsign)
/* p->right = 65535 - p->right + 1; */
p->right = -p->right;
if (p->valleft)
if (p->valleft->dsckind.opnd.dsign)
/* p->left = 65535 - p->left + 1; */
p->left = -p->left;
}
/*** shiftoper - execute shift left or right
*
* result = shiftoper (p);
*
* Entry *p = parse stack entry
* Exit none
* Returns shifted value
* Calls
*/
OFFSET PASCAL CODESIZE
shiftoper (
register struct exprec *p
){
register OFFSET argl;
register USHORT argr;
argl = p->valleft->dsckind.opnd.doffset;
if (p->valleft->dsckind.opnd.dsign)
argl = -argl;
argr = p->valright->dsckind.opnd.doffset;
if (p->valright->dsckind.opnd.dsign) {
errorc (E_SCN);
return (argl);
}
else if (sizeof(OFFSET)*8 < argr)
return (0);
else if (p->stkoper == OPSHL)
return (argl << argr);
else
return (argl >> argr);
}
/* VALcheck is used by all OPERATOR execute routines to make
sure their arguments are correct. If the arguments are
expected to be some kind of result( i.e. not a structure
or record item or data size ), the old argument is destroy-
ed and DEFAULTdsc is called to create a substitute. Error
messages are also generated on type mismatches. A number
of procedures of the form: VALUExxxx are called, these
check if the given argument is of that type and if not,
generate an error and a value of zero. There is one kludge
in this procedure, the LENGTH OPERATOR should work with
records and structures, but these are still in the form of
<Isym> records so they will work with MASK, ...
The operand types are as follows:
Callabs May be unary or binary. In any case, all
values must have a NIL segment.
Clsize May be unary or binary. If unary, value must
be a size( which is: structure name, -2 .. n
or BYTE WORD ... ). If binary, left value is
a size.
Csame Is always binary. If not results, coerce them.
Both must belong to the same segment and not
be external.
Cdata Is always unary. Result must be associated
with data( Dtype is [data] ). Exception if
LENGTH OPERATOR and is record or record field
in which case converts to approriate result
record.
Ccode Is always unary. Result must be associated
with code( Dtype is [code] ).
Crec Is always unary. Value must be record field
or record name.
Cseg Is always unary. Value must have a segment.
Cvar Always unary. Value must be constant or data
or code.
Clseg Always binary. The left value must be a
SEGresult or a segment register.
Coneabs Always binary. One of the values must be a
constant.
Csamabs Always binary. Either both values have the
same segment or the second value is a constant
*/
/*** valconst - give error if value is not constant
*
* routine ();
*
* Entry
* Exit
* Returns
* Calls
*/
VOID PASCAL CODESIZE
valconst (
register DSCREC *arg
){
if (!(M_RCONST & arg->dsckind.opnd.dtype) ||
arg->dsckind.opnd.dsegment ||
arg->dsckind.opnd.dflag == XTERNAL)
/* Not constant */
errorc (E_CXP);
}
/*** valusize - check size of operand
*
* val = valusize (arg);
*
* Entry
* Exit
* Returns
* Calls
*/
USHORT PASCAL CODESIZE
valuesize (
register DSCREC *arg
){
if (!fArth32)
arg->dsckind.opnd.doffset = (long) (SHORT) arg->dsckind.opnd.doffset;
if (arg->dsckind.opnd.doffset == 0) {
/* 0 means no size */
errorc (E_OHS);
return (0);
}
else if (arg->dsckind.opnd.doffset >= CSFAR_LONG)
return (xltsymtoresult[PROC]);
else
return (xltsymtoresult[DVAR]);
}
/*** valcheck - check operand value
*
* valcheck (valtype, unary, p);
*
* Entry
* Exit
* Returns
* Calls
*/
VOID PASCAL CODESIZE
valcheck (
UCHAR valtype,
UCHAR unary,
register struct exprec *p
){
register struct psop *psol; /* parse stack operand structure */
register struct psop *psor; /* parse stack operand structure */
psol = &(p->valleft->dsckind.opnd);
psor = &(p->valright->dsckind.opnd);
/* Should give error if have 2 externals */
if (p->valleft)
if (psol->dflag == XTERNAL && psor->dflag == XTERNAL)
errorc (E_IUE);
switch (valtype) {
case CALLABS:
valconst (p->valright);
if (!unary)
valconst (p->valleft);
break;
case CLSIZE:
if (unary)
psor->dtype = valuesize (p->valright);
else
psol->dtype = valuesize (p->valleft);
break;
case CSAME:
if (psol->dsegment != psor->dsegment)
errorc (E_OMM);
break;
case CDATA:
if ((p->stkoper != OPLENGTH) || !psor->dextptr
|| (psor->dflag == XTERNAL)) {
if (!(M_DATA & psor->dtype) &&
(psor->dlength == 0))
errorc (E_ASD);
}
else {
/* Special case for LENGTH */
p->valleft = defaultdsc ();
/* Create value */
p->valleft->prec = p->valright->prec;
psol = &(p->valleft->dsckind.opnd);
psol->dlength = psor->dextptr->length;
/* Lose old value */
oblititem (p->valright);
p->valright = p->valleft;
p->valleft = NULL;
psor = psol;
psol = NULL;
}
break;
case CCODE:
if (!(M_CODE & p->valright->dsckind.opnd.dtype))
errorc (E_ASC);
break;
case CREC:
if (!psor->dextptr || psor->dflag == XTERNAL)
errorc (E_RRF);
break;
case CSEG:
if (!psor->dsegment && psor->dflag != XTERNAL
|| (M_REGRESULT & psor->dtype))
errorc (E_OSG);
break;
case CLSEG:
if (M_SEGRESULT & psol->dtype) {
/* ??? if (!psor->dsegment || (psor->dtype & M_RCONST))
errorc (E_IOT); ??? */
}
else if (M_REGRESULT & psol->dtype) {
if (psol->dsegment->symu.regsym.regtype != SEGREG)
errorc (E_LOS);
}
else
errorc (E_LOS);
break;
case CONEABS:
if (psor->dsegment && psol->dsegment)
errorc (E_OOC);
break;
case CSAMABS:
if (psor->dsegment &&
psol->dsegment != psor->dsegment)
errorc (E_OSA);
break;
}
p->right = psor->doffset;
if (p->valleft)
p->left = psol->doffset;
}
/*** regcheck - check for <arg> a register in [...]
*
* routine ();
*
* Entry
* Exit
* Returns
* Calls
*/
DSCREC * PASCAL CODESIZE
regcheck (
DSCREC *arg,
UCHAR minus,
register struct exprec *ptr
){
struct psop *pso; /* parse stack operand structure */
register struct ar *pAR;
USHORT reg;
pso = &(arg->dsckind.opnd);
pAR = ptr->p->p;
if (M_REGRESULT & pso->dtype) {
/* Is some register */
if (ptr->p->parenflag || pAR->bracklevel) {
/* Have index reg in []s */
/* Lose size based on register */
pso->dsize = 0;
reg = pso->dsegment->offset;
/* Must be index or ptr reg */
switch(pso->dsegment->symu.regsym.regtype)
{
default:
errorc (E_IBR);
break;
case INDREG:
if (reg <= 5)
/* Have base reg BX | BP */
if (pAR->base)
errorc (E_DBR);
else
pAR->base = reg;
else /* Have index reg DI | SI */
if (pAR->index)
errorc (E_DIR);
else
pAR->index = reg;
break;
#ifdef V386
case DWRDREG:
/* Have 386 reg in []s */
if (minus == 2)
{
if (pAR->index & 0xf)
errorc(E_DIR);
pAR->index |= 8 | reg;
}
else if (pAR->base)
{
if (pAR->index)
errorc(E_DIR);
if (reg == 4) {
/* swap base with index
* to allow [index][eSp] */
pAR->index = pAR->base;
pAR->base = 4|8;
}
else
pAR->index = reg|8;
}
else
pAR->base = reg|8;
break;
#endif /* V386 */
}
if (minus == TRUE && (ptr->valright == arg))
errorc (E_IUR);
oblititem (arg);
return (defaultdsc ());
}
else {
errorc(E_IUR);
return (arg);
}
}
#ifdef V386 /* scaled indexing modes */
else if (minus == 2 && (M_RCONST & pso->dtype))
{
if (pAR->index&0x70)
errorc(E_MBR);
if (highWord(arg->dsckind.opnd.doffset))
goto scaleErr;
switch((SHORT) arg->dsckind.opnd.doffset) {
case 1:
pAR->index |= 0x10;
break;
case 2:
pAR->index |= 0x20;
break;
case 4:
pAR->index |= 0x30;
break;
case 8:
pAR->index |= 0x40;
break;
scaleErr:
default:
error(E_EXP, "scale value of 1,2,4 or 8");
}
oblititem (arg);
return (defaultdsc ());
}
#endif /* V386 */
else return (arg);
}
/*** idxcheck - check for arg to +- is register
*
* routine ();
*
* Entry
* Exit
* Returns
* Calls
* Note See if arg to +/- is register, in which case see if should
* be stored in Ridx or Rbas due to []s
*/
VOID PASCAL CODESIZE
idxcheck (
UCHAR minus,
register struct exprec *p
){
p->valleft = regcheck (p->valleft, minus, p);
p->valright = regcheck (p->valright, minus, p);
p->right = p->valright->dsckind.opnd.doffset;
p->left = p->valleft->dsckind.opnd.doffset;
}
/*** makeGrpRel - make an offset group relative
*
* routine ();
*
* Entry
* Exit
* Returns
* Calls
*/
VOID PASCAL CODESIZE
makeGrpRel (
register struct psop *p
){
if (!(p->dtype&M_EXPLCOLON) && p->dsegment &&
p->dsegment->symkind == SEGMENT && p->dsegment->symu.segmnt.grouptr){
p->dtype |= M_GROUPSEG;
p->dcontext = p->dsegment->symu.segmnt.grouptr;
}
}
/*** evaltop - evaluate top entry
*
* routine ();
*
* Entry
* Exit
* Returns
* Calls
*/
VOID PASCAL CODESIZE
evaltop (
struct evalrec *ptr
){
register struct psop *psol; /* parse stack operand structure */
register struct psop *psor; /* parse stack operand structure */
struct exprec a;
a.p = ptr;
/* Get right operand */
a.valright = popvalue (a.p->p);
itemptr = NULL;
if (a.p->p->lastitem) {
/* Get OPERATOR */
a.stkoper = popoperator (a.p->p);
a.valleft = NULL;
/* assume is unary */
if (!inset (a.stkoper, unaryset))
/* Not unary OPERATOR */
a.valleft = (a.stkoper == OPUNPLUS || a.stkoper == OPUNMINUS)
? defaultdsc() : popvalue (a.p->p);
/* Save for EVALtop */
a.p->idx = a.stkoper;
if (a.valleft)
a.valleft->prec = a.valright->prec;
psol = &(a.valleft->dsckind.opnd);
psor = &(a.valright->dsckind.opnd);
switch (a.stkoper) {
/* All OPERATORs are executed thru this CASE statement. The
* VALcheck routine makes sure operands are of the correct
* type and may create dummy entries in the case of the real
* operand not being of type result when required. The REStype
* routine uses it's argument to know what part of the result
* record should be kept and the type of the result. Unary
* and binary OPERATORs both return their results in VALright. */
case OPAND:
case OPOR:
case OPXOR:
/* Make sure operands ok */
valcheck (CALLABS, FALSE, &a);
/* Must work on 16 bits */
foldsigns (&a);
switch (a.stkoper) {
case OPAND:
psor->doffset = a.left & a.right;
break;
case OPOR:
psor->doffset = a.left | a.right;
break;
case OPXOR:
psor->doffset = a.left ^ a.right;
break;
}
psor->dsign = FALSE;
/* Must clear out Dsign in case was signed value */
break;
case OPNOT:
/* TRUE constant arg */
valcheck (CALLABS, TRUE, &a);
foldsigns (&a);
psor->doffset = ~a.right;
psor->dsign = FALSE;
if (optyp == TDB &&
(psor->doffset & ((OFFSET) ~0xff)) == ((OFFSET) ~0xff))
psor->doffset &= 0xFF;
#ifdef V386_noCode
if (!(cputype & P386)) /* truncate result to 16 bits */
psor->doffset &= 0xffff; /* for compatablity */
#endif
break;
case OPSHL:
case OPSHR:
valcheck (CALLABS, FALSE, &a);
psor->doffset = shiftoper (&a);
psor->dsign = FALSE;
break;
case OPSEG:
/* Must have segment */
valcheck (CSEG, TRUE, &a);
if (psor->dcontext && !(psor->dtype&M_EXPLCOLON))
psor->dsegment = psor->dcontext;
psor->dtype = (psor->dtype&M_FORTYPE) | M_SEGRESULT| M_RCONST;
psor->doffset = 0;
psor->dsign = FALSE;
break;
case OPDOT:
/* See if idx reg */
idxcheck (FALSE, &a);
valcheck (CONEABS, FALSE, &a);
psol = &(a.valleft->dsckind.opnd);
psor = &(a.valright->dsckind.opnd);
if (psor->dsize)
psol->dsize = psor->dsize;
/* Adjust signs on records */
signadjust (FALSE, &a);
psol = &(a.valleft->dsckind.opnd);
psor = &(a.valright->dsckind.opnd);
break;
case OPUNPLUS:
case OPPLUS:
/* See if idx reg */
idxcheck (FALSE, &a);
valcheck (CONEABS, FALSE, &a);
psol = &(a.valleft->dsckind.opnd);
psor = &(a.valright->dsckind.opnd);
/* Adjust signs on records */
signadjust (FALSE, &a);
psol = &(a.valleft->dsckind.opnd);
psor = &(a.valright->dsckind.opnd);
break;
case OPUNMINUS:
case OPMINUS:
idxcheck (TRUE, &a);
if (psor->dsegment == psol->dsegment &&
psol->dsegment) {
if (psol->dtype & M_SEGRESULT) {
psol->dtype = M_SEGRESULT | M_RCONST;
psol->doffset = 0;
psol->dsign = FALSE;
}
if (psor->dtype & M_SEGRESULT) {
psor->dtype = M_SEGRESULT | M_RCONST;
psor->doffset = 0;
psor->dsign = FALSE;
}
}
valcheck (CSAMABS, FALSE, &a);
signadjust (TRUE, &a);
psol = &(a.valleft->dsckind.opnd);
psor = &(a.valright->dsckind.opnd);
if (psol->dsegment) {
/* clear Dcontext if have var-var */
psor->dtype = (psor->dtype &
(M_EXPLOFFSET | M_PTRSIZE | M_FORTYPE)) | M_RCONST;
psor->dsegment = NULL;
psor->dcontext = NULL;
psor->dsize = 0;
oblititem (a.valleft);
a.valleft = NULL;
}
break;
case OPMULT:
#ifdef V386
if (M_REGRESULT & (psol->dtype|psor->dtype))
{
if (cputype&P386) {
idxcheck (2, &a);
if (a.p->p->index&0x78)
break;
} else
errorc (E_IRV);
}
#endif
/* fall through */
case OPDIV:
valcheck (CALLABS, FALSE, &a);
/* Both are constant */
if (a.stkoper == OPMULT)
psor->doffset = a.left * a.right;
else if (a.right == 0)
errorc (E_DVZ);
else
psor->doffset = a.left / a.right;
if (psor->doffset == 0)
psor->dsign = FALSE;
else
psor->dsign = (psol->dsign != psor->dsign);
break;
case OPHIGH:
if (psor->dtype & M_RCONST) {
if (psor->dsign) {
psor->doffset = -psor->doffset;
psor->dsign = 0;
}
psor->doffset = psor->doffset >> 8 & 0xff;
}
psor->dtype |= M_HIGH;
goto highlow;
case OPLOW:
if (psor->dtype & M_RCONST)
psor->doffset &= 0xFF;
psor->dtype |= M_LOW;
highlow:
psor->dsize = 1;
if ((!(psor->dflag & XTERNAL && psor->dtype & M_EXPLOFFSET))
&& psor->dsegment
&& (psor->dtype & (M_EXPLOFFSET | M_SEGRESULT
| M_REGRESULT | M_GROUPSEG | M_DATA | M_CODE)))
errorc (E_CXP);
break;
case OPOFFSET:
psor->fixtype = FOFFSET;
if (!(psor->dsegment || psor->dflag == XTERNAL))
errorc(E_OSG|E_WARN2);
if (!(M_DATA & psor->dtype))
psor->dcontext = NULL;
psor->dtype =
(psor->dtype |
M_RCONST | M_EXPLOFFSET) & ~(M_SEGRESULT);
if (fSimpleSeg)
makeGrpRel (psor);
/* preserve OFFSET arg size it's a const */
if ((psor->dsegment ||
psor->dcontext ||
psor->dflag == XTERNAL) &&
!(M_PTRSIZE & psor->dtype))
psor->dsize = 0;
break;
case OPLENGTH:
case OPSIZE:
/* Must be data associated */
valcheck (CDATA, TRUE, &a);
psol = &(a.valleft->dsckind.opnd);
psor = &(a.valright->dsckind.opnd);
if (a.stkoper == OPLENGTH)
psor->doffset = psor->dlength;
else
psor->doffset =
psor->dsize * psor->dlength;
psor->dflag &= ~XTERNAL;
break;
case OPTYPE:
a.right = psor->dsize;
oblititem (a.valright);
a.valright = defaultdsc ();
psor = &(a.valright->dsckind.opnd);
psor->doffset = a.right;
a.p->p->base = 0;
a.p->p->index = 0;
break;
case OPMASK:
case OPWIDTH:
/* Must be record or field */
valcheck (CREC, TRUE, &a);
if (psor->dextptr && psor->dflag != XTERNAL) {
if (a.stkoper == OPWIDTH)
if (psor->dextptr->symkind == REC)
psor->doffset = psor->dextptr->length;
else
psor->doffset = psor->dextptr->symu.rec.recwid;
else if (psor->dextptr->symkind == REC)
psor->doffset = psor->dextptr->offset;
else
psor->doffset = psor->dextptr->symu.rec.recmsk;
}
break;
case OPSTYPE:
a.right = 0;
if (errorcode == 0) {
if (psor->dflag == XTERNAL)
a.right |= 0x80; /* external */
if (psor->dflag != UNDEFINED)
a.right |= 0x20; /* defined */
if (psor->dtype & M_DATA)
a.right |= 0x02; /* data */
if (psor->dtype & M_CODE)
a.right |= 0x01; /* program */
if ((a.p->p->base == 0) && (a.p->p->index == 0)) {
if (psor->dtype == xltsymtoresult[REGISTER])
a.right |= 0x10; /* register */
else if (psor->dtype & M_RCONST)
a.right |= 0x04; /* constant */
else if (psor->dtype & M_DATA)
a.right |= 0x08; /* direct */
} else {
a.p->p->base = 0;
a.p->p->index = 0;
}
}
oblititem (a.valright);
a.valright = defaultdsc ();
psor = &(a.valright->dsckind.opnd);
psor->doffset = a.right;
errorcode = 0;
break;
case OPLPAR:
case OPLBRK:
if (!(a.p->parenflag || a.p->p->exprdone))
pushpar (a.p);
else if (a.stkoper == OPLBRK)
a.valright = regcheck (a.valright, FALSE, &a);
psol = &(a.valleft->dsckind.opnd);
psor = &(a.valright->dsckind.opnd);
break;
case OPMOD:
valcheck (CALLABS, FALSE, &a);
if (a.right == 0) {
/* div 0 */
errorc (E_DVZ);
psor->doffset = 0;
psor->dsign = FALSE;
}
else {
psor->doffset = a.left % a.right;
if (psor->doffset == 0 || !psol->dsign)
psor->dsign = FALSE;
else
psor->dsign = TRUE;
}
break;
case OPTHIS:
valcheck (CLSIZE, TRUE, &a);
/* Unary, right is size */
psor->s = 0;
psor->dsize = a.right;
psor->doffset = pcoffset;
psor->dsegment = pcsegment;
if (a.right >= CSFAR_LONG)
psor->dcontext = regsegment[CSSEG];
break;
case OPSHORT:
valcheck (CCODE, TRUE, &a);
/* Unary, must be code */
psor->dtype |= M_SHRT;
break;
case OPPTR:
valcheck (CLSIZE, FALSE, &a);
if (psol->doffset >= CSFAR_LONG &&
(M_RCONST == psor->dtype ||
(psor->dcontext && (M_DATA&psor->dtype && !(M_CODE&psor->dtype))) ))
errorc (E_NSO); /* Can't code_data */
else {
psor->dsize = a.left;
if ((M_DATA & psol->dtype)
&& !(M_DATA & psor->dtype))
psor->dcontext = NULL;
/* Change code/data */
psor->dtype =
(psor->dtype & ~(M_CODE | M_DATA) |
(psol->dtype & (M_CODE | M_DATA))) &
~(M_FORTYPE) | (M_PTRSIZE);
}
break;
case OPEQ:
case OPGE:
case OPGT:
case OPLE:
case OPLT:
case OPNE:
valcheck (CSAME, FALSE, &a);
signadjust (TRUE, &a);
/* Do signed R=L-R */
psol = &(a.valleft->dsckind.opnd);
psor = &(a.valright->dsckind.opnd);
if (!fArth32)
a.right &= 0xffff;
switch (a.stkoper) {
case OPEQ:
a.right = (a.right == 0);
break;
case OPGE:
a.right = !psor->dsign;
break;
case OPGT:
a.right = (!psor->dsign && a.right);
break;
case OPLE:
a.right = (psor->dsign || a.right == 0);
break;
case OPLT:
a.right = psor->dsign;
break;
case OPNE:
a.right = (a.right != 0);
break;
}
/* Set Dsign if result TRUE */
psor->doffset = a.right;
psor->dsign = (a.right == 1);
psor->dcontext = NULL;
oblititem (a.valleft);
a.valleft = NULL;
break;
case OPCOLON:
/* <segment> : <var> */
valcheck (CLSEG, FALSE, &a);
if ((a.p->p->bracklevel || a.p->evalop == OPLBRK) &&
(M_REGRESULT & (psol->dtype | psor->dtype)))
errorc(E_ISR);
psor->dtype = (psor->dtype|M_EXPLCOLON|M_DATA) & ~M_RCONST;
if (psol->dsegment) {
if (psol->dsegment->symkind == GROUP)
psor->dtype |= M_GROUPSEG;
if (!psor->dsegment &&
!(M_REGRESULT & psol->dtype) &&
!(a.p->p->base || a.p->p->index))
psor->dsegment = psol->dsegment;
}
psor->dcontext = psol->dsegment;
break;
} /* operator case */
if (!inset (a.stkoper, parseset)) {
/* Have constant or segment result */
psor->dlength = 0;
psor->dsize = 0;
psor->sized = 0;
if (a.valleft)
psol->dsize = 0;
/* Have constant result( typeless ) */
if (a.stkoper != OPSEG) {
psor->dtype = (psor->dtype & M_FORTYPE) | M_RCONST;
psor->dsegment = NULL;
if (a.valleft)
psol->dtype &= ~M_PTRSIZE;
}
}
a.p->p->curresult = a.valright;
psor = &(a.p->p->curresult->dsckind.opnd);
if (!fArth32 && optyp != TDD)
psor->doffset &= 0xffff;
if (a.valleft) {
/* Might need to copy some info */
/* Prevent OPERATORs like +, -, . from
losing the [DATA] flag if it it is the
Left operand. This is ok, except when
surrounded by a PTR which will drop
segment override if not data type */
if (a.stkoper != OPCOLON)
psor->dtype |= psol->dtype & (M_DATA | M_CODE);
if (psor->dflag == KNOWN)
psor->dflag = psol->dflag;
if (!psor->dcontext)
psor->dcontext = psol->dcontext;
if (psor->dsize == 0)
psor->dsize = psol->dsize;
if (psor->fixtype == FCONSTANT)
psor->fixtype = psol->fixtype;
psor->dtype |= psol->dtype & (M_PTRSIZE|M_EXPLOFFSET|M_FORTYPE);
/* Above makes sure PTR or OFFSET is not lost */
oblititem (a.valleft);
a.valleft = NULL;
}
}
else { /* no operator case */
a.p->p->curresult = a.valright;
psor = &(a.p->p->curresult->dsckind.opnd);
a.p->parenflag = FALSE;
}
if (!a.p->p->lastitem) {
a.p->p->lastprec = 0;
a.p->p->curresult->prec = 0;
}
else if (a.p->p->lastitem->itype == OPERATOR) {
if ((a.p->p->lastitem->dsckind.opr.oidx == OPLBRK) ||
(a.p->p->lastitem->dsckind.opr.oidx == OPLPAR))
/* Stop evaluating back at paren */
a.p->p->lastprec = 0;
else {
a.p->p->lastprec = a.p->p->lastitem->prec;
if ((a.p->p->lastitem->dsckind.opr.oidx == OPUNPLUS) ||
(a.p->p->lastitem->dsckind.opr.oidx == OPUNMINUS))
/* Force eval */
a.p->p->lastitem->prec = a.p->p->lastprec = 20;
}
}
else
a.p->p->lastprec = a.p->p->lastitem->prec;
if (itemptr) {
oblititem (itemptr);
itemptr = NULL;
}
/* Hook rest of list in */
a.p->p->curresult->previtem = a.p->p->lastitem;
a.p->p->lastitem = a.p->p->curresult;
/* Push result back on */
if (!a.p->p->curresult->previtem && a.p->p->exprdone)
a.p->p->lastitem = NULL;
}
/*** evaluate - evaluate stack
*
* routine ();
*
* Entry
* Exit
* Returns
* Calls
*/
VOID PASCAL CODESIZE
evaluate (
struct ar *p
){
struct evalrec a;
a.p = p;
a.parenflag = FALSE;
a.evalop = OPNOTHING;
/* No paren or match to find */
a.curoper = itemptr;
if (a.curoper)
a.parenflag = !a.p->exprdone &&
(a.curoper->dsckind.opr.oidx == OPRPAR ||
a.curoper->dsckind.opr.oidx == OPRBRK);
if (a.parenflag)
a.evalop = (a.curoper->dsckind.opr.oidx == OPRPAR)? OPLPAR: OPLBRK;
do { /* Evaluate to OPERATOR */
evaltop (&a);
} while (a.p->lastitem && a.p->lastitem->previtem &&
(a.p->exprdone ||
(!a.parenflag && a.p->lastprec >= a.p->curprec ) ||
( a.parenflag && a.idx != a.evalop)) );
/* stop if just value on expression stack */
itemptr = a.curoper;
if (a.p->lastprec == 0)
a.p->lastprec = a.p->curresult->prec;
if (!a.p->exprdone)
if (a.parenflag) {/* Push value and set prec */
if (!a.p->lastitem->previtem)/* start of expr */
a.p->lastprec = 0;
else
a.p->lastprec = a.p->lastitem->previtem->prec;
/* Restore preced */
a.p->lastitem->prec = a.p->lastprec;
oblititem (itemptr);
itemptr = NULL;
/* Destroy close paren */
}
else { /* Case 1, OPERATOR eval */
itemptr->previtem = a.p->lastitem;
a.p->lastitem = itemptr;
/* Push OPERATOR */
if (a.p->lastprec != 20)
a.p->lastprec = itemptr->prec;
}
}
/* Return a descriptor record to help instruction routines
generate the right code. The items are as follows:
mode:: Value 0..4 Corresponds to 8086 mod
0 No displacement unless rm=6 in which
case this is direct mode with 2 bytes.
( Arg is code or data, no indexing )
1 Memory, 8 bit sign extended displace-
ment.( Using indexing, Rconst )
2 Memory, 16 bit displacement.( Using
indexing, Rconst type )
3 Register, rm is register code, not
indexing mode.( Was REGresult )
4 Immediate mode.( arg was Rconst, no
indexing )
386 modes are represented in an analogous way:
3 Register, rm is register code, as above
4 Immediate, as above
5 No displacement indirect, unless rm=5,
in which case this is a direct mode with
4 byte offset.
6 Memory, 8 bit signed displacement
7 Memory, 32 bit signed displacement
similarly, scaled modes are indicated with
the next group. if mode > 7, then rm contains
the value of the Scaled Index Byte (SIB) and
rm is implicitly 4.
8 No displacement indirect, unless rm=5,
in which case this is a direct mode with
4 byte offset.
9 Memory, 8 bit signed displacement
10 Memory, 32 bit signed displacement
rm :: Value 0..7 Corresponds to 8086 or 80386 r/m
Value Register Index 386 index
0 AX AL EAX [BX][SI] [EAX]
1 CX CL ECX [BX][DI] [ECX]
2 DX DL EDX [BP][SI] [EDX]
3 BX BL EBX [BP][DI] [EBX]
4 SP AH ESP [SI] not implemented
5 BP CH EBP [DI] Direct or [EBP]
6 SI DH ESI Direct or [BP] [ESI]
7 DI BH EDI [BX] [EDI]
Ridx contained pointer to index reg( DI | SI )
Rbas contained pointer to base reg( BX | BP )
Both were NIL if no indexing.
386 registers have 8 added to them while in
the ar structure's base and index fields.
this is so we can tell eax from no register
at all.
w :: Boolean Corresponds to 8086 w flag. TRUE if
word mode, FALSE if byte mode.
s :: TRUE if value is -128..+127
Dsize :: Size of var/label or PTR value
FIXtype :: Type of fixup to feed to EMITxxx
routines:
Fpointer Label is FAR
Foffset Word, not constant
Fbaseseg SEG or seg/group name
Fgroupseg Offset to group
Fconstant Immediate data
Fhigh Take high of offset
Flow Take low of offset
Fnone No fixup( register )
Dtype :: Kind of value. Seg,group, const, Data
Dflag :: Value attr, undef,?,extern,forw,...
Doffset :: 16 bit value of result
Dsegment:: Copy of Dsegment. Pointer to segment of
result. If NIL, is constant. Will point
to segment name or possibly name of
external if external with no segment.
Dcontext:: Copy of Dcontext. Pointer to segment
from which to calculate offset. If :
OPERATOR used, Dcontext will be left
arg. If result is code label, will be
CS assume at time of label define. Else
will be NIL and then filled in with
segment register assume that contains
Dsegment.
seg :: Segment register of override. If none
given, will be 4. If register is not
known, will be 5.
*/
