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Implement formal functions and procedures
[unix-history] / usr / src / usr.bin / pascal / src / stkrval.c
/* Copyright (c) 1979 Regents of the University of California */
static char sccsid[] = "@(#)stkrval.c 1.3 %G%";
#include "whoami.h"
#include "0.h"
#include "tree.h"
#include "opcode.h"
#include "objfmt.h"
#ifdef PC
# include "pcops.h"
#endif PC
/*
* stkrval Rvalue - an expression, and coerce it to be a stack quantity.
*
* Contype is the type that the caller would prefer, nand is important
* if constant sets or constant strings are involved, the latter
* because of string padding.
*/
/*
* for the obj version, this is a copy of rvalue hacked to use fancy new
* push-onto-stack-and-convert opcodes.
* for the pc version, i just call rvalue and convert if i have to,
* based on the return type of rvalue.
*/
struct nl *
stkrval(r, contype , required )
register int *r;
struct nl *contype;
long required;
{
register struct nl *p;
register struct nl *q;
register char *cp, *cp1;
register int c, w;
int **pt;
long l;
double f;
if (r == NIL)
return (NIL);
if (nowexp(r))
return (NIL);
/*
* The root of the tree tells us what sort of expression we have.
*/
switch (r[0]) {
/*
* The constant nil
*/
case T_NIL:
# ifdef OBJ
put(2, O_CON14, 0);
# endif OBJ
# ifdef PC
putleaf( P2ICON , 0 , 0 , P2INT , 0 );
# endif PC
return (nl+TNIL);
case T_FCALL:
case T_VAR:
p = lookup(r[2]);
if (p == NIL || p->class == BADUSE)
return (NIL);
switch (p->class) {
case VAR:
/*
if a variable is
* qualified then get
* the rvalue by a
* stklval and an ind.
*/
if (r[3] != NIL)
goto ind;
q = p->type;
if (q == NIL)
return (NIL);
if (classify(q) == TSTR)
return(stklval(r, NOFLAGS));
# ifdef OBJ
w = width(q);
switch (w) {
case 8:
put(2, O_RV8 | bn << 8+INDX, p->value[0]);
return(q);
case 4:
put(2, O_RV4 | bn << 8+INDX, p->value[0]);
return(q);
case 2:
put(2, O_RV24 | bn << 8+INDX, p->value[0]);
return(q);
case 1:
put(2, O_RV14 | bn << 8+INDX, p->value[0]);
return(q);
default:
put(3, O_RV | bn << 8+INDX, p->value[0], w);
return(q);
}
# endif OBJ
# ifdef PC
return rvalue( r , contype , required );
# endif PC
case WITHPTR:
case REF:
/*
* A stklval for these
* is actually what one
* might consider a rvalue.
*/
ind:
q = stklval(r, NOFLAGS);
if (q == NIL)
return (NIL);
if (classify(q) == TSTR)
return(q);
# ifdef OBJ
w = width(q);
switch (w) {
case 8:
put(1, O_IND8);
return(q);
case 4:
put(1, O_IND4);
return(q);
case 2:
put(1, O_IND24);
return(q);
case 1:
put(1, O_IND14);
return(q);
default:
put(2, O_IND, w);
return(q);
}
# endif OBJ
# ifdef PC
if ( required == RREQ ) {
putop( P2UNARY P2MUL , p2type( q ) );
}
return q;
# endif PC
case CONST:
if (r[3] != NIL) {
error("%s is a constant and cannot be qualified", r[2]);
return (NIL);
}
q = p->type;
if (q == NIL)
return (NIL);
if (q == nl+TSTR) {
/*
* Find the size of the string
* constant if needed.
*/
cp = p->ptr[0];
cstrng:
cp1 = cp;
for (c = 0; *cp++; c++)
continue;
w = 0;
if (contype != NIL && !opt('s')) {
if (width(contype) < c && classify(contype) == TSTR) {
error("Constant string too long");
return (NIL);
}
w = width(contype) - c;
}
# ifdef OBJ
put(2, O_LVCON, lenstr(cp1, w));
putstr(cp1, w);
# endif OBJ
# ifdef PC
putCONG( cp1 , c + w , LREQ );
# endif PC
/*
* Define the string temporarily
* so later people can know its
* width.
* cleaned out by stat.
*/
q = defnl(0, STR, 0, c);
q->type = q;
return (q);
}
if (q == nl+T1CHAR) {
# ifdef OBJ
put(2, O_CONC4, p->value[0]);
# endif OBJ
# ifdef PC
putleaf( P2ICON , p -> value[0] , 0 , P2CHAR , 0 );
# endif PC
return(q);
}
/*
* Every other kind of constant here
*/
# ifdef OBJ
switch (width(q)) {
case 8:
#ifndef DEBUG
put(2, O_CON8, p->real);
return(q);
#else
if (hp21mx) {
f = p->real;
conv(&f);
l = f.plong;
put(2, O_CON4, l);
} else
put(2, O_CON8, p->real);
return(q);
#endif
case 4:
put(2, O_CON4, p->range[0]);
return(q);
case 2:
put(2, O_CON24, (short)p->range[0]);
return(q);
case 1:
put(2, O_CON14, (short)p->range[0]);
return(q);
default:
panic("stkrval");
}
# endif OBJ
# ifdef PC
return rvalue( r , contype , required );
# endif PC
case FUNC:
case FFUNC:
/*
* Function call
*/
pt = (int **)r[3];
if (pt != NIL) {
switch (pt[1][0]) {
case T_PTR:
case T_ARGL:
case T_ARY:
case T_FIELD:
error("Can't qualify a function result value");
return (NIL);
}
}
# ifdef OBJ
q = p->type;
if (classify(q) == TSTR) {
c = width(q);
put(2, O_LVCON, even(c+1));
putstr("", c);
put(1, O_SDUP4);
p = funccod(r);
put(2, O_AS, c);
return(p);
}
p = funccod(r);
if (width(p) <= 2)
put(1, O_STOI);
# endif OBJ
# ifdef PC
p = pcfunccod( r );
# endif PC
return (p);
case TYPE:
error("Type names (e.g. %s) allowed only in declarations", p->symbol);
return (NIL);
case PROC:
case FPROC:
error("Procedure %s found where expression required", p->symbol);
return (NIL);
default:
panic("stkrvid");
}
case T_PLUS:
case T_MINUS:
case T_NOT:
case T_AND:
case T_OR:
case T_DIVD:
case T_MULT:
case T_SUB:
case T_ADD:
case T_MOD:
case T_DIV:
case T_EQ:
case T_NE:
case T_GE:
case T_LE:
case T_GT:
case T_LT:
case T_IN:
p = rvalue(r, contype , required );
# ifdef OBJ
if (width(p) <= 2)
put(1, O_STOI);
# endif OBJ
return (p);
case T_CSET:
p = rvalue(r, contype , required );
return (p);
default:
if (r[2] == NIL)
return (NIL);
switch (r[0]) {
default:
panic("stkrval3");
/*
* An octal number
*/
case T_BINT:
f = a8tol(r[2]);
goto conint;
/*
* A decimal number
*/
case T_INT:
f = atof(r[2]);
conint:
if (f > MAXINT || f < MININT) {
error("Constant too large for this implementation");
return (NIL);
}
l = f;
if (bytes(l, l) <= 2) {
# ifdef OBJ
put(2, O_CON24, (short)l);
# endif OBJ
# ifdef PC
putleaf( P2ICON , (short) l , 0 , P2INT , 0 );
# endif PC
return(nl+T4INT);
}
# ifdef OBJ
put(2, O_CON4, l);
# endif OBJ
# ifdef PC
putleaf( P2ICON , l , 0 , P2INT , 0 );
# endif PC
return (nl+T4INT);
/*
* A floating point number
*/
case T_FINT:
# ifdef OBJ
put(2, O_CON8, atof(r[2]));
# endif OBJ
# ifdef PC
putCON8( atof( r[2] ) );
# endif PC
return (nl+TDOUBLE);
/*
* Constant strings. Note that constant characters
* are constant strings of length one; there is
* no constant string of length one.
*/
case T_STRNG:
cp = r[2];
if (cp[1] == 0) {
# ifdef OBJ
put(2, O_CONC4, cp[0]);
# endif OBJ
# ifdef PC
putleaf( P2ICON , cp[0] , 0 , P2CHAR , 0 );
# endif PC
return(nl+T1CHAR);
}
goto cstrng;
}
}
}
Continuous source code history from original PDP-7 UNIX to FreeBSD 2, the first fully unencumbered FreeBSD release.