| 1 | /* Copyright (c) 1979 Regents of the University of California */ |
| 2 | #include <stdio.h> |
| 3 | #include "as.h" |
| 4 | #include "asexpr.h" |
| 5 | |
| 6 | /* |
| 7 | * Tables for combination of operands. |
| 8 | */ |
| 9 | |
| 10 | /* |
| 11 | * table for + |
| 12 | */ |
| 13 | readonly char pltab[6][6] = { |
| 14 | /* UND ABS TXT DAT BSS EXT */ |
| 15 | |
| 16 | /*UND*/ XUNDEF, XUNDEF, XUNDEF, XUNDEF, XUNDEF, XUNDEF, |
| 17 | /*ABS*/ XUNDEF, XABS, XTEXT, XDATA, XBSS, XXTRN, |
| 18 | /*TXT*/ XUNDEF, XTEXT, ERR, ERR, ERR, ERR, |
| 19 | /*DAT*/ XUNDEF, XDATA, ERR, ERR, ERR, ERR, |
| 20 | /*BSS*/ XUNDEF, XBSS, ERR, ERR, ERR, ERR, |
| 21 | /*EXT*/ XUNDEF, XXTRN, ERR, ERR, ERR, ERR, |
| 22 | }; |
| 23 | |
| 24 | /* |
| 25 | * table for - |
| 26 | */ |
| 27 | readonly char mintab[6][6] = { |
| 28 | /* UND ABS TXT DAT BSS EXT */ |
| 29 | |
| 30 | /*UND*/ XUNDEF, XUNDEF, XUNDEF, XUNDEF, XUNDEF, XUNDEF, |
| 31 | /*ABS*/ XUNDEF, XABS, ERR, ERR, ERR, ERR, |
| 32 | /*TXT*/ XUNDEF, XTEXT, XABS, ERR, ERR, ERR, |
| 33 | /*DAT*/ XUNDEF, XDATA, ERR, XABS, ERR, ERR, |
| 34 | /*BSS*/ XUNDEF, XBSS, ERR, ERR, XABS, ERR, |
| 35 | /*EXT*/ XUNDEF, XXTRN, ERR, ERR, ERR, ERR, |
| 36 | }; |
| 37 | |
| 38 | /* |
| 39 | * table for other operators |
| 40 | */ |
| 41 | readonly char othtab[6][6] = { |
| 42 | /* UND ABS TXT DAT BSS EXT */ |
| 43 | |
| 44 | /*UND*/ XUNDEF, XUNDEF, XUNDEF, XUNDEF, XUNDEF, XUNDEF, |
| 45 | /*ABS*/ XUNDEF, XABS, ERR, ERR, ERR, ERR, |
| 46 | /*TXT*/ XUNDEF, ERR, ERR, ERR, ERR, ERR, |
| 47 | /*DAT*/ XUNDEF, ERR, ERR, ERR, ERR, ERR, |
| 48 | /*BSS*/ XUNDEF, ERR, ERR, ERR, ERR, ERR, |
| 49 | /*EXT*/ XUNDEF, ERR, ERR, ERR, ERR, ERR, |
| 50 | }; |
| 51 | |
| 52 | struct exp * |
| 53 | combine(op, exp1, exp2) |
| 54 | register struct exp *exp1, *exp2; |
| 55 | { |
| 56 | register e1_type, e2_type; |
| 57 | register type; |
| 58 | |
| 59 | lastnam=0; /* kludge for jxxx instructions */ |
| 60 | |
| 61 | e1_type = exp1->xtype&XTYPE; |
| 62 | e2_type = exp2->xtype&XTYPE; |
| 63 | |
| 64 | if (exp1->xtype==XXTRN+XUNDEF) |
| 65 | e1_type = XTXRN; |
| 66 | if (exp2->xtype==XXTRN+XUNDEF) |
| 67 | e2_type = XTXRN; |
| 68 | if (passno==1) |
| 69 | if (exp1->xloc!=exp2->xloc && e1_type==e2_type) |
| 70 | e1_type = e2_type = XTXRN; /* error on != loc ctrs */ |
| 71 | e1_type >>= 1; /*dispost of the external (XXTRN) bit*/ |
| 72 | e2_type >>= 1; |
| 73 | |
| 74 | switch (op) { |
| 75 | case PLUS: |
| 76 | exp1->xvalue += exp2->xvalue; |
| 77 | type = pltab[e1_type][e2_type]; |
| 78 | break; |
| 79 | case MINUS: |
| 80 | exp1->xvalue -= exp2->xvalue; |
| 81 | type = mintab[e1_type][e2_type]; |
| 82 | break; |
| 83 | case IOR: |
| 84 | exp1->xvalue |= exp2->xvalue; |
| 85 | goto comm; |
| 86 | case XOR: |
| 87 | exp1->xvalue ^= exp2->xvalue; |
| 88 | goto comm; |
| 89 | case AND: |
| 90 | exp1->xvalue &= exp2->xvalue; |
| 91 | goto comm; |
| 92 | case ORNOT: |
| 93 | exp1->xvalue |= ~exp2->xvalue; |
| 94 | goto comm; |
| 95 | case LSH: |
| 96 | exp1->xvalue <<= exp2->xvalue; |
| 97 | goto comm; |
| 98 | case RSH: |
| 99 | exp1->xvalue >>= exp2->xvalue; |
| 100 | goto comm; |
| 101 | case TILDE: |
| 102 | exp1->xvalue |= ~ exp2->xvalue; |
| 103 | goto comm; |
| 104 | case MUL: |
| 105 | exp1->xvalue *= exp2->xvalue; |
| 106 | goto comm; |
| 107 | case DIV: |
| 108 | if (exp2->xvalue == 0) |
| 109 | yyerror("Divide check"); |
| 110 | else |
| 111 | exp1->xvalue /= exp2->xvalue; |
| 112 | goto comm; |
| 113 | case REGOP: |
| 114 | if (exp2->xvalue == 0) |
| 115 | yyerror("Divide check (modulo)"); |
| 116 | else |
| 117 | exp1->xvalue %= exp2->xvalue; |
| 118 | goto comm; |
| 119 | |
| 120 | comm: |
| 121 | type = othtab[e1_type][e2_type]; |
| 122 | break; |
| 123 | default: |
| 124 | yyerror("Internal error: unknown operator"); |
| 125 | } |
| 126 | |
| 127 | if (e2_type==(XTXRN>>1)) |
| 128 | exp1->xname = exp2->xname; |
| 129 | exp1->xtype = type | ( |
| 130 | (exp1->xtype|exp2->xtype) & (XFORW|XXTRN) ); |
| 131 | if (type==ERR) |
| 132 | yyerror("Relocation error"); |
| 133 | return(exp1); |
| 134 | } |
| 135 | |
| 136 | buildtokensets() |
| 137 | { |
| 138 | #define clobber(val, set) tokensets[(val)] |= (set) |
| 139 | |
| 140 | clobber(SEMI, LINSTBEGIN); |
| 141 | clobber(NL, LINSTBEGIN); |
| 142 | |
| 143 | clobber(NAME, YUKKYEXPRBEG + LINSTBEGIN); |
| 144 | clobber(INSTn, YUKKYEXPRBEG); |
| 145 | clobber(INST0, YUKKYEXPRBEG); |
| 146 | clobber(REG, YUKKYEXPRBEG); |
| 147 | |
| 148 | clobber(INT, SAFEEXPRBEG); |
| 149 | clobber(FLTNUM, SAFEEXPRBEG); |
| 150 | |
| 151 | clobber(PLUS, ADDOPS); |
| 152 | clobber(MINUS, ADDOPS + EBEGOPS); |
| 153 | |
| 154 | clobber(LP, EBEGOPS); |
| 155 | |
| 156 | clobber(IOR, BOOLOPS); |
| 157 | clobber(XOR, BOOLOPS); |
| 158 | clobber(AND, BOOLOPS); |
| 159 | clobber(ORNOT, BOOLOPS); |
| 160 | |
| 161 | clobber(TILDE, MULOPS + EBEGOPS); |
| 162 | clobber(LSH, MULOPS); |
| 163 | clobber(RSH, MULOPS); |
| 164 | clobber(MUL, MULOPS); |
| 165 | clobber(DIV, MULOPS); |
| 166 | clobber(REGOP, MULOPS); /* % */ |
| 167 | } |
| 168 | |
| 169 | /* |
| 170 | * We keep the current token class in this global variable, so |
| 171 | * the recursive descent expression analyzers can talk amongst |
| 172 | * themselves, and so that we may use the macros shift and shift over |
| 173 | */ |
| 174 | |
| 175 | extern int yylval; /*the value of the lexical value*/ |
| 176 | extern struct exp *xp; /*the next free expression slot*/ |
| 177 | |
| 178 | static int val; |
| 179 | int exprparse(inval, backexpr) /*return the value the read head is sitting on*/ |
| 180 | int inval; |
| 181 | struct exp **backexpr; |
| 182 | { |
| 183 | register struct exp *lexpr; |
| 184 | int op; |
| 185 | |
| 186 | val = inval; |
| 187 | lexpr = boolterm(); |
| 188 | while (INTOKSET(val, ADDOPS)){ |
| 189 | op = val; |
| 190 | shift; |
| 191 | lexpr = combine(op, lexpr, boolterm()); |
| 192 | } |
| 193 | *backexpr = lexpr; |
| 194 | return(val); |
| 195 | } |
| 196 | |
| 197 | struct exp *boolterm() |
| 198 | { |
| 199 | register struct exp *lexpr; |
| 200 | int op; |
| 201 | |
| 202 | lexpr = term(); |
| 203 | while(INTOKSET(val, BOOLOPS)){ |
| 204 | op = val; |
| 205 | shift; |
| 206 | lexpr = combine(op, lexpr, term()); |
| 207 | } |
| 208 | return(lexpr); |
| 209 | } |
| 210 | |
| 211 | struct exp *term() |
| 212 | { |
| 213 | register struct exp *lexpr; |
| 214 | int op; |
| 215 | |
| 216 | lexpr = factor(); |
| 217 | while(INTOKSET(val, MULOPS)){ |
| 218 | op = val; |
| 219 | shift; |
| 220 | lexpr = combine(op, lexpr, factor()); |
| 221 | } |
| 222 | return(lexpr); |
| 223 | } |
| 224 | |
| 225 | struct exp *factor() |
| 226 | { |
| 227 | struct exp *lexpr; |
| 228 | int op; |
| 229 | extern int droppedLP; /*called exprparse after consuming an LP*/ |
| 230 | |
| 231 | if (val == LP || droppedLP){ |
| 232 | if (droppedLP) |
| 233 | droppedLP = 0; |
| 234 | else |
| 235 | shift; /*the LP*/ |
| 236 | val = exprparse(val, &lexpr); |
| 237 | if (val != RP) |
| 238 | yyerror("right parenthesis expected"); |
| 239 | else |
| 240 | shift; |
| 241 | } else |
| 242 | if (INTOKSET(val, YUKKYEXPRBEG)){ |
| 243 | lexpr = yukkyexpr(val, yylval); |
| 244 | shift; |
| 245 | } |
| 246 | else if (INTOKSET(val, SAFEEXPRBEG)){ |
| 247 | lexpr = (struct exp *)yylval; |
| 248 | shift; |
| 249 | } |
| 250 | else if ( (val == TILDE) || (val == MINUS) ){ |
| 251 | op = val; |
| 252 | shift; |
| 253 | lexpr = xp++; |
| 254 | lexpr->xtype = XABS; |
| 255 | lexpr->xvalue = 0; |
| 256 | lexpr = combine(op, lexpr, factor()); |
| 257 | } |
| 258 | else { |
| 259 | yyerror("Bad expression syntax"); |
| 260 | lexpr = xp++; |
| 261 | lexpr->xtype = XABS; |
| 262 | lexpr->xvalue = 0; |
| 263 | } |
| 264 | return(lexpr); |
| 265 | } |
| 266 | |
| 267 | struct exp *yukkyexpr(val, np) |
| 268 | int val; |
| 269 | register np; |
| 270 | { |
| 271 | register struct exp *locxp; |
| 272 | extern int exprisname; /*last factor is a name*/ |
| 273 | |
| 274 | exprisname = 0; |
| 275 | locxp = xp++; |
| 276 | if (val == NAME){ |
| 277 | exprisname++; |
| 278 | locxp->xtype = ((struct symtab *)np)->type; |
| 279 | if (( ((struct symtab *)np)->type&XTYPE)==XUNDEF) { /*forward*/ |
| 280 | locxp->xname = (struct symtab *)np; |
| 281 | locxp->xvalue = 0; |
| 282 | if (passno==1) |
| 283 | ((struct symtab *)np)->type |= XFORW; |
| 284 | } else { /*otherwise, just get the value*/ |
| 285 | locxp->xvalue = ((struct symtab *)np)->value; |
| 286 | locxp->xname = NULL; |
| 287 | } |
| 288 | } else { /*INSTn or INST0 or REG*/ |
| 289 | locxp->xtype = XABS; |
| 290 | locxp->xvalue = ( (int)np) & 0xFF; |
| 291 | locxp->xloc = 0; |
| 292 | locxp->xname = NULL; |
| 293 | } |
| 294 | |
| 295 | return(locxp); |
| 296 | } |