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BSD 4 release
[unix-history] / usr / src / cmd / as / asexpr.c
/* Copyright (c) 1980 Regents of the University of California */
static char sccsid[] = "@(#)asexpr.c 4.2 8/15/80";
#include <stdio.h>
#include "as.h"
#include "asexpr.h"
/*
* Tables for combination of operands.
*/
#define XTXRN 5<<1 /* indexes last row/column when right shifted */
/*
* table for +
*/
readonly char pltab[6][6] = {
/* UND ABS TXT DAT BSS EXT */
/*UND*/ XUNDEF, XUNDEF, XUNDEF, XUNDEF, XUNDEF, XUNDEF,
/*ABS*/ XUNDEF, XABS, XTEXT, XDATA, XBSS, XXTRN,
/*TXT*/ XUNDEF, XTEXT, ERR, ERR, ERR, ERR,
/*DAT*/ XUNDEF, XDATA, ERR, ERR, ERR, ERR,
/*BSS*/ XUNDEF, XBSS, ERR, ERR, ERR, ERR,
/*EXT*/ XUNDEF, XXTRN, ERR, ERR, ERR, ERR,
};
/*
* table for -
*/
readonly char mintab[6][6] = {
/* UND ABS TXT DAT BSS EXT */
/*UND*/ XUNDEF, XUNDEF, XUNDEF, XUNDEF, XUNDEF, XUNDEF,
/*ABS*/ XUNDEF, XABS, ERR, ERR, ERR, ERR,
/*TXT*/ XUNDEF, XTEXT, XABS, ERR, ERR, ERR,
/*DAT*/ XUNDEF, XDATA, ERR, XABS, ERR, ERR,
/*BSS*/ XUNDEF, XBSS, ERR, ERR, XABS, ERR,
/*EXT*/ XUNDEF, XXTRN, ERR, ERR, ERR, ERR,
};
/*
* table for other operators
*/
readonly char othtab[6][6] = {
/* UND ABS TXT DAT BSS EXT */
/*UND*/ XUNDEF, XUNDEF, XUNDEF, XUNDEF, XUNDEF, XUNDEF,
/*ABS*/ XUNDEF, XABS, ERR, ERR, ERR, ERR,
/*TXT*/ XUNDEF, ERR, ERR, ERR, ERR, ERR,
/*DAT*/ XUNDEF, ERR, ERR, ERR, ERR, ERR,
/*BSS*/ XUNDEF, ERR, ERR, ERR, ERR, ERR,
/*EXT*/ XUNDEF, ERR, ERR, ERR, ERR, ERR,
};
struct exp *
combine(op, exp1, exp2)
register struct exp *exp1, *exp2;
{
register e1_type, e2_type;
register back_type;
lastnam=0; /* kludge for jxxx instructions */
e1_type = exp1->e_xtype&XTYPE;
e2_type = exp2->e_xtype&XTYPE;
if (exp1->e_xtype==XXTRN+XUNDEF)
e1_type = XTXRN;
if (exp2->e_xtype==XXTRN+XUNDEF)
e2_type = XTXRN;
if (passno==1)
if (exp1->e_xloc!=exp2->e_xloc && e1_type==e2_type)
e1_type = e2_type = XTXRN; /* error on != loc ctrs */
e1_type >>= 1; /*dispose of the external (XXTRN) bit*/
e2_type >>= 1;
switch (op) {
case PLUS:
exp1->e_xvalue += exp2->e_xvalue;
back_type = pltab[e1_type][e2_type];
break;
case MINUS:
exp1->e_xvalue -= exp2->e_xvalue;
back_type = mintab[e1_type][e2_type];
break;
case IOR:
exp1->e_xvalue |= exp2->e_xvalue;
goto comm;
case XOR:
exp1->e_xvalue ^= exp2->e_xvalue;
goto comm;
case AND:
exp1->e_xvalue &= exp2->e_xvalue;
goto comm;
case ORNOT:
exp1->e_xvalue |= ~exp2->e_xvalue;
goto comm;
case LSH:
exp1->e_xvalue <<= exp2->e_xvalue;
goto comm;
case RSH:
exp1->e_xvalue >>= exp2->e_xvalue;
goto comm;
case TILDE:
exp1->e_xvalue |= ~ exp2->e_xvalue;
goto comm;
case MUL:
exp1->e_xvalue *= exp2->e_xvalue;
goto comm;
case DIV:
if (exp2->e_xvalue == 0)
yyerror("Divide check");
else
exp1->e_xvalue /= exp2->e_xvalue;
goto comm;
case REGOP:
if (exp2->e_xvalue == 0)
yyerror("Divide check (modulo)");
else
exp1->e_xvalue %= exp2->e_xvalue;
goto comm;
comm:
back_type = othtab[e1_type][e2_type];
break;
default:
yyerror("Internal error: unknown operator");
}
if (e2_type==(XTXRN>>1))
exp1->e_xname = exp2->e_xname;
exp1->e_xtype = back_type | (
(exp1->e_xtype|exp2->e_xtype) & (XFORW|XXTRN) );
if (back_type==ERR)
yyerror("Relocation error");
return(exp1);
}
buildtokensets()
{
#define clobber(val, set) tokensets[(val)] |= (set)
clobber(SEMI, LINSTBEGIN);
clobber(NL, LINSTBEGIN);
clobber(INT, LINSTBEGIN);
clobber(NAME, YUKKYEXPRBEG + LINSTBEGIN);
clobber(INSTn, YUKKYEXPRBEG);
clobber(INST0, YUKKYEXPRBEG);
clobber(REG, YUKKYEXPRBEG);
clobber(BFINT, YUKKYEXPRBEG);
clobber(INT, SAFEEXPRBEG);
clobber(FLTNUM, SAFEEXPRBEG);
clobber(PLUS, ADDOPS);
clobber(MINUS, ADDOPS + EBEGOPS);
clobber(LP, EBEGOPS);
clobber(IOR, BOOLOPS);
clobber(XOR, BOOLOPS);
clobber(AND, BOOLOPS);
clobber(ORNOT, BOOLOPS);
clobber(TILDE, MULOPS + EBEGOPS);
clobber(LSH, MULOPS);
clobber(RSH, MULOPS);
clobber(MUL, MULOPS);
clobber(DIV, MULOPS);
clobber(REGOP, MULOPS); /* % */
}
/*
* We keep the current token class in this global variable, so
* the recursive descent expression analyzers can talk amongst
* themselves, and so that we may use the macros shift and shift over
*/
extern int yylval; /*the value of the lexical value*/
extern struct exp *xp; /*the next free expression slot*/
static int val;
int exprparse(inval, backexpr) /*return the value the read head is sitting on*/
int inval;
struct exp **backexpr;
{
register struct exp *lexpr;
int op;
val = inval;
lexpr = boolterm();
while (INTOKSET(val, ADDOPS)){
op = val;
shift;
lexpr = combine(op, lexpr, boolterm());
}
*backexpr = lexpr;
return(val);
}
struct exp *boolterm()
{
register struct exp *lexpr;
int op;
lexpr = term();
while(INTOKSET(val, BOOLOPS)){
op = val;
shift;
lexpr = combine(op, lexpr, term());
}
return(lexpr);
}
struct exp *term()
{
register struct exp *lexpr;
int op;
lexpr = factor();
while(INTOKSET(val, MULOPS)){
op = val;
shift;
lexpr = combine(op, lexpr, factor());
}
return(lexpr);
}
struct exp *factor()
{
struct exp *lexpr;
int op;
extern int droppedLP; /*called exprparse after consuming an LP*/
if (val == LP || droppedLP){
if (droppedLP)
droppedLP = 0;
else
shift; /*the LP*/
val = exprparse(val, &lexpr);
if (val != RP)
yyerror("right parenthesis expected");
else
shift;
} else
if (INTOKSET(val, YUKKYEXPRBEG)){
lexpr = yukkyexpr(val, yylval);
shift;
}
else if (INTOKSET(val, SAFEEXPRBEG)){
lexpr = (struct exp *)yylval;
shift;
}
else if ( (val == TILDE) || (val == MINUS) ){
op = val;
shift;
lexpr = xp++;
lexpr->e_xtype = XABS;
lexpr->e_xvalue = 0;
lexpr = combine(op, lexpr, factor());
}
else {
yyerror("Bad expression syntax");
lexpr = xp++;
lexpr->e_xtype = XABS;
lexpr->e_xvalue = 0;
}
return(lexpr);
}
struct exp *yukkyexpr(val, np)
int val;
register np;
{
register struct exp *locxp;
extern int exprisname; /*last factor is a name*/
exprisname = 0;
locxp = xp++;
if (val == NAME || val == BFINT){
if (val == BFINT) {
int off = 0;
yylval = ((struct exp *)np)->e_xvalue;
if (yylval < 0) {
yylval = -yylval;
yylval--;
off = -1;
if (lgensym[yylval] == 1)
yyerror("Reference to undefined local label %db", yylval);
} else {
yylval--;
genref[yylval] = 1;
}
sprintf(yytext, "L%d\001%d", yylval, lgensym[yylval] + off);
yylval = np = (int)*lookup(passno == 1);
lastnam = (struct symtab *)np;
}
exprisname++;
locxp->e_xtype = ((struct symtab *)np)->s_type;
if (( ((struct symtab *)np)->s_type&XTYPE)==XUNDEF) { /*forward*/
locxp->e_xname = (struct symtab *)np;
locxp->e_xvalue = 0;
if (passno==1)
((struct symtab *)np)->s_type |= XFORW;
} else { /*otherwise, just get the value*/
locxp->e_xvalue = ((struct symtab *)np)->s_value;
locxp->e_xname = NULL;
}
} else { /*INSTn or INST0 or REG*/
locxp->e_xtype = XABS;
locxp->e_xvalue = ( (int)np) & 0xFF;
locxp->e_xloc = 0;
locxp->e_xname = NULL;
}
return(locxp);
}
#ifdef DEBUG
char *tok_name[LASTTOKEN - FIRSTTOKEN + 1];
struct Tok_Desc{
int tok_which;
char *tok_name;
} tok_desc[] = {
FIRSTTOKEN, "firsttoken", /* 0 */
ISPACE, "ispace", /* 1 */
IBYTE, "ibyte", /* 2 */
IWORD, "iword", /* 3 */
IINT, "iint", /* 4 */
ILONG, "ilong", /* 5 */
IDATA, "idata", /* 6 */
IGLOBAL, "iglobal", /* 7 */
ISET, "iset", /* 8 */
ITEXT, "itext", /* 9 */
ICOMM, "icomm", /* 10 */
ILCOMM, "ilcomm", /* 11 */
IFLOAT, "ifloat", /* 12 */
IDOUBLE, "idouble", /* 13 */
IORG, "iorg", /* 14 */
IASCII, "iascii", /* 15 */
IASCIZ, "iasciz", /* 16 */
ILSYM, "ilsym", /* 17 */
IFILE, "ifile", /* 18 */
ILINENO, "ilineno", /* 19 */
IABORT, "iabort", /* 20 */
ISTAB, "istab", /* 23 */
ISTABSTR, "istabstr", /* 24 */
ISTABNONE, "istabnone", /* 25 */
ISTABDOT, "istabdot", /* 26 */
IJXXX, "ijxxx", /* 27 */
IALIGN, "ialign", /* 28 */
INST0, "inst0", /* 29 */
INSTn, "instn", /* 30 */
BFINT, "bfint", /* 31 */
PARSEEOF, "parseeof", /* 32 */
ILINESKIP, "ilineskip", /* 33 */
VOID, "void", /* 34 */
SKIP, "skip", /* 35 */
INT, "int", /* 36 */
FLTNUM, "fltnum", /* 37 */
NAME, "name", /* 38 */
STRING, "string", /* 39 */
QUAD, "quad", /* 40 */
SIZESPEC, "sizespec", /* 41 */
REG, "reg", /* 42 */
MUL, "mul", /* 43 */
LITOP, "litop", /* 44 */
LP, "lp", /* 45 */
MP, "mp", /* 46 */
NEEDSBUF, "needsbuf", /* 48 */
REGOP, "regop", /* 49 */
NL, "nl", /* 50 */
SCANEOF, "scaneof", /* 51 */
BADCHAR, "badchar", /* 52 */
SP, "sp", /* 53 */
ALPH, "alph", /* 54 */
DIG, "dig", /* 55 */
SQ, "sq", /* 56 */
DQ, "dq", /* 57 */
SH, "sh", /* 58 */
LSH, "lsh", /* 59 */
RSH, "rsh", /* 60 */
MINUS, "minus", /* 61 */
SIZEQUOTE, "sizequote", /* 62 */
XOR, "xor", /* 64 */
DIV, "div", /* 65 */
SEMI, "semi", /* 66 */
COLON, "colon", /* 67 */
PLUS, "plus", /* 68 */
IOR, "ior", /* 69 */
AND, "and", /* 70 */
TILDE, "tilde", /* 71 */
ORNOT, "ornot", /* 72 */
CM, "cm", /* 73 */
LB, "lb", /* 74 */
RB, "rb", /* 75 */
RP, "rp", /* 76 */
LASTTOKEN, "lasttoken" /* 80 */
};
/*
* turn a token type into a string
*/
static int fixed = 0;
char *tok_to_name(token)
{
if (!fixed){
int i;
for (i = FIRSTTOKEN; i <= LASTTOKEN; i++)
tok_name[i] = "NOT ASSIGNED";
for (i = FIRSTTOKEN; i <= sizeof(tok_desc)/sizeof(struct Tok_Desc); i++){
tok_name[tok_desc[i].tok_which] = tok_desc[i].tok_name;
}
fixed = 1;
}
if (FIRSTTOKEN <= token && token <= LASTTOKEN)
return(tok_name[token]);
else
panic("Unknown token number, %d\n", token);
/*NOTREACHED*/
}
#endif DEBUG
Continuous source code history from original PDP-7 UNIX to FreeBSD 2, the first fully unencumbered FreeBSD release.