| 1 | /* Copyright (c) 1979 Regents of the University of California */ |
| 2 | # |
| 3 | /* |
| 4 | * pi - Pascal interpreter code translator |
| 5 | * |
| 6 | * Charles Haley, Bill Joy UCB |
| 7 | * Version 1.2 January 1979 |
| 8 | */ |
| 9 | |
| 10 | #include "0.h" |
| 11 | #include "tree.h" |
| 12 | |
| 13 | /* |
| 14 | * Type declaration part |
| 15 | */ |
| 16 | typebeg() |
| 17 | { |
| 18 | |
| 19 | #ifndef PI1 |
| 20 | if (parts & VPRT) |
| 21 | error("Type declarations must precede var declarations"); |
| 22 | if (parts & TPRT) |
| 23 | error("All types must be declared in one type part"); |
| 24 | parts =| TPRT; |
| 25 | #endif |
| 26 | /* |
| 27 | * Forechain is the head of a list of types that |
| 28 | * might be self referential. We chain them up and |
| 29 | * process them later. |
| 30 | */ |
| 31 | forechain = NIL; |
| 32 | #ifdef PI0 |
| 33 | send(REVTBEG); |
| 34 | #endif |
| 35 | } |
| 36 | |
| 37 | type(tline, tid, tdecl) |
| 38 | int tline; |
| 39 | char *tid; |
| 40 | register int *tdecl; |
| 41 | { |
| 42 | register struct nl *np; |
| 43 | |
| 44 | np = gtype(tdecl); |
| 45 | line = tline; |
| 46 | if (np != NIL && (tdecl[0] == T_ID || tdecl[0] == T_TYID)) |
| 47 | np = nlcopy(np); |
| 48 | #ifndef PI0 |
| 49 | enter(defnl(tid, TYPE, np, 0))->nl_flags =| NMOD; |
| 50 | #else |
| 51 | enter(defnl(tid, TYPE, np, 0)); |
| 52 | send(REVTYPE, tline, tid, tdecl); |
| 53 | #endif |
| 54 | } |
| 55 | |
| 56 | typeend() |
| 57 | { |
| 58 | |
| 59 | #ifdef PI0 |
| 60 | send(REVTEND); |
| 61 | #endif |
| 62 | foredecl(); |
| 63 | } |
| 64 | \f |
| 65 | /* |
| 66 | * Return a type pointer (into the namelist) |
| 67 | * from a parse tree for a type, building |
| 68 | * namelist entries as needed. |
| 69 | */ |
| 70 | gtype(r) |
| 71 | register int *r; |
| 72 | { |
| 73 | register struct nl *np; |
| 74 | register char *cp; |
| 75 | int oline; |
| 76 | |
| 77 | if (r == NIL) |
| 78 | return (NIL); |
| 79 | oline = line; |
| 80 | if (r[0] != T_ID) |
| 81 | oline = line = r[1]; |
| 82 | switch (r[0]) { |
| 83 | default: |
| 84 | panic("type"); |
| 85 | case T_TYID: |
| 86 | r++; |
| 87 | case T_ID: |
| 88 | np = lookup(r[1]); |
| 89 | if (np == NIL) |
| 90 | break; |
| 91 | if (np->class != TYPE) { |
| 92 | #ifndef PI1 |
| 93 | error("%s is a %s, not a type as required", r[1], classes[np->class]); |
| 94 | #endif |
| 95 | np = NIL; |
| 96 | break; |
| 97 | } |
| 98 | np = np->type; |
| 99 | break; |
| 100 | case T_TYSCAL: |
| 101 | np = tyscal(r); |
| 102 | break; |
| 103 | case T_TYRANG: |
| 104 | np = tyrang(r); |
| 105 | break; |
| 106 | case T_TYPTR: |
| 107 | np = defnl(0, PTR, 0, r[2]); |
| 108 | np->nl_next = forechain; |
| 109 | forechain = np; |
| 110 | break; |
| 111 | case T_TYPACK: |
| 112 | np = gtype(r[2]); |
| 113 | break; |
| 114 | case T_TYARY: |
| 115 | np = tyary(r); |
| 116 | break; |
| 117 | case T_TYREC: |
| 118 | np = tyrec(r[2], 0); |
| 119 | break; |
| 120 | case T_TYFILE: |
| 121 | np = gtype(r[2]); |
| 122 | if (np == NIL) |
| 123 | break; |
| 124 | #ifndef PI1 |
| 125 | if (np->nl_flags & NFILES) |
| 126 | error("Files cannot be members of files"); |
| 127 | #endif |
| 128 | np = defnl(0, FILE, np, 0); |
| 129 | np->nl_flags =| NFILES; |
| 130 | break; |
| 131 | case T_TYSET: |
| 132 | np = gtype(r[2]); |
| 133 | if (np == NIL) |
| 134 | break; |
| 135 | if (np->type == nl+TDOUBLE) { |
| 136 | #ifndef PI1 |
| 137 | error("Set of real is not allowed"); |
| 138 | #endif |
| 139 | np = NIL; |
| 140 | break; |
| 141 | } |
| 142 | if (np->class != RANGE && np->class != SCAL) { |
| 143 | #ifndef PI1 |
| 144 | error("Set type must be range or scalar, not %s", nameof(np)); |
| 145 | #endif |
| 146 | np = NIL; |
| 147 | break; |
| 148 | } |
| 149 | #ifndef PI1 |
| 150 | if (width(np) > 2) |
| 151 | error("Implementation restriction: sets must be indexed by 16 bit quantities"); |
| 152 | #endif |
| 153 | np = defnl(0, SET, np, 0); |
| 154 | break; |
| 155 | } |
| 156 | line = oline; |
| 157 | return (np); |
| 158 | } |
| 159 | |
| 160 | /* |
| 161 | * Scalar (enumerated) types |
| 162 | */ |
| 163 | tyscal(r) |
| 164 | int *r; |
| 165 | { |
| 166 | register struct nl *np, *op; |
| 167 | register *v; |
| 168 | int i; |
| 169 | |
| 170 | np = defnl(0, SCAL, 0, 0); |
| 171 | np->type = np; |
| 172 | v = r[2]; |
| 173 | if (v == NIL) |
| 174 | return (NIL); |
| 175 | i = -1; |
| 176 | for (; v != NIL; v = v[2]) { |
| 177 | op = enter(defnl(v[1], CONST, np, ++i)); |
| 178 | #ifndef PI0 |
| 179 | op->nl_flags =| NMOD; |
| 180 | #endif |
| 181 | op->value[1] = i; |
| 182 | } |
| 183 | np->range[1] = i; |
| 184 | return (np); |
| 185 | } |
| 186 | |
| 187 | /* |
| 188 | * Declare a subrange. |
| 189 | */ |
| 190 | tyrang(r) |
| 191 | register int *r; |
| 192 | { |
| 193 | register struct nl *lp, *hp; |
| 194 | double high; |
| 195 | int c, c1; |
| 196 | |
| 197 | gconst(r[3]); |
| 198 | hp = con.ctype; |
| 199 | high = con.crval; |
| 200 | gconst(r[2]); |
| 201 | lp = con.ctype; |
| 202 | if (lp == NIL || hp == NIL) |
| 203 | return (NIL); |
| 204 | if (norange(lp) || norange(hp)) |
| 205 | return (NIL); |
| 206 | c = classify(lp); |
| 207 | c1 = classify(hp); |
| 208 | if (c != c1) { |
| 209 | #ifndef PI1 |
| 210 | error("Can't mix %ss and %ss in subranges", nameof(lp), nameof(hp)); |
| 211 | #endif |
| 212 | return (NIL); |
| 213 | } |
| 214 | if (c == TSCAL && scalar(lp) != scalar(hp)) { |
| 215 | #ifndef PI1 |
| 216 | error("Scalar types must be identical in subranges"); |
| 217 | #endif |
| 218 | return (NIL); |
| 219 | } |
| 220 | if (con.crval > high) { |
| 221 | #ifndef PI1 |
| 222 | error("Range lower bound exceeds upper bound"); |
| 223 | #endif |
| 224 | return (NIL); |
| 225 | } |
| 226 | lp = defnl(0, RANGE, hp->type, 0); |
| 227 | lp->range[0] = con.crval; |
| 228 | lp->range[1] = high; |
| 229 | return (lp); |
| 230 | } |
| 231 | |
| 232 | norange(p) |
| 233 | register struct nl *p; |
| 234 | { |
| 235 | if (isa(p, "d")) { |
| 236 | #ifndef PI1 |
| 237 | error("Subrange of real is not allowed"); |
| 238 | #endif |
| 239 | return (1); |
| 240 | } |
| 241 | if (isnta(p, "bcsi")) { |
| 242 | #ifndef PI1 |
| 243 | error("Subrange bounds must be Boolean, character, integer or scalar, not %s", nameof(p)); |
| 244 | #endif |
| 245 | return (1); |
| 246 | } |
| 247 | return (0); |
| 248 | } |
| 249 | |
| 250 | /* |
| 251 | * Declare arrays and chain together the dimension specification |
| 252 | */ |
| 253 | tyary(r) |
| 254 | int *r; |
| 255 | { |
| 256 | struct nl *np; |
| 257 | register *tl; |
| 258 | register struct nl *tp, *ltp; |
| 259 | int i; |
| 260 | |
| 261 | tp = gtype(r[3]); |
| 262 | if (tp == NIL) |
| 263 | return (NIL); |
| 264 | np = defnl(0, ARRAY, tp, 0); |
| 265 | np->nl_flags =| (tp->nl_flags) & NFILES; |
| 266 | ltp = np; |
| 267 | i = 0; |
| 268 | for (tl = r[2]; tl != NIL; tl = tl[2]) { |
| 269 | tp = gtype(tl[1]); |
| 270 | if (tp == NIL) { |
| 271 | np = NIL; |
| 272 | continue; |
| 273 | } |
| 274 | if (tp->class == RANGE && tp->type == nl+TDOUBLE) { |
| 275 | #ifndef PI1 |
| 276 | error("Index type for arrays cannot be real"); |
| 277 | #endif |
| 278 | np = NIL; |
| 279 | continue; |
| 280 | } |
| 281 | if (tp->class != RANGE && tp->class != SCAL) { |
| 282 | #ifndef PI1 |
| 283 | error("Array index type is a %s, not a range or scalar as required", classes[tp->class]); |
| 284 | #endif |
| 285 | np = NIL; |
| 286 | continue; |
| 287 | } |
| 288 | if (tp->class == RANGE && bytes(tp->range[0], tp->range[1]) > 2) { |
| 289 | #ifndef PI1 |
| 290 | error("Value of dimension specifier too large or small for this implementation"); |
| 291 | #endif |
| 292 | continue; |
| 293 | } |
| 294 | tp = nlcopy(tp); |
| 295 | i++; |
| 296 | ltp->chain = tp; |
| 297 | ltp = tp; |
| 298 | } |
| 299 | if (np != NIL) |
| 300 | np->value[0] = i; |
| 301 | return (np); |
| 302 | } |
| 303 | |
| 304 | /* |
| 305 | * Delayed processing for pointers to |
| 306 | * allow self-referential and mutually |
| 307 | * recursive pointer constructs. |
| 308 | */ |
| 309 | foredecl() |
| 310 | { |
| 311 | register struct nl *p, *q; |
| 312 | |
| 313 | for (p = forechain; p != NIL; p = p->nl_next) { |
| 314 | if (p->class == PTR && p->value[0] != 0) |
| 315 | { |
| 316 | p->type = gtype(p->value[0]); |
| 317 | #ifndef PI1 |
| 318 | if (p->type != NIL && (p->type->nl_flags & NFILES)) |
| 319 | error("Files cannot be members of dynamic structures"); |
| 320 | #endif |
| 321 | p->value[0] = 0; |
| 322 | } |
| 323 | } |
| 324 | } |