84 lines
1.2 KiB
C++
84 lines
1.2 KiB
C++
// The symbol table is an array of structs.
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//
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// U *get_symbol(char *printname) Adds symbol if not in table.
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//
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// char *get_printname(U *)
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#include "stdafx.h"
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#include "defs.h"
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int nsym; // number of symbols in table
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#define YMAX 1000
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U symtab[YMAX];
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static char *printname[YMAX];
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U *
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get_symbol(char *s)
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{
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int i;
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U *p;
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for (i = 0; i < nsym; i++)
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if (strcmp(s, printname[i]) == 0)
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return symtab + i;
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if (nsym == YMAX)
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stop("symbol table overflow");
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p = symtab + nsym;
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printname[nsym] = strdup(s);
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nsym++;
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p->k = SYM;
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p->u.sym.binding = p;
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p->u.sym.binding2 = nil;
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return p;
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}
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char *
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get_printname(U *p)
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{
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int n;
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n = (int) (p - symtab);
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return printname[n];
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}
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void
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clear_symbols(void)
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{
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int i;
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U *p;
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for (i = 0; i < nsym; i++) {
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p = symtab + i;
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if (p->k == SYM) {
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p->u.sym.binding = p;
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p->u.sym.binding2 = nil;
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}
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}
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}
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// keyword functions for quickly finding system symbols
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U *stab[300]; // 0-199 for built-in functions, 200-299 for variables
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U *
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symbol(int k)
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{
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return stab[k];
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}
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void
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push_symbol(int k)
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{
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push(stab[k]);
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}
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void
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define_symbol(char *s, int k)
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{
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stab[k] = get_symbol(s);
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stab[k]->k = k;
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}
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void
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define_variable(char *s, int k)
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{
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stab[k] = get_symbol(s);
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}
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