/* $Id$ */ /* * (c) copyright 1987 by the Vrije Universiteit, Amsterdam, The Netherlands. * See the copyright notice in the ACK home directory, in the file "Copyright". */ /* s y m t a b . c * * Contains the routine findident, which builds the symbol table and * searches identifiers */ #include #include #include "symtab.h" #include "main.h" struct symtab *idtable, *deftable; struct symtab *findident(char *s, int mode, struct symtab **table) { /* * Look for identifier s in the symboltable referred to by *table. * If mode = LOOKING, no new entry's will be made. * If mode = ENTERING, a new entry will be made if s is not in the * table yet, otherwise an error results */ struct symtab *p; int n; if (!*table) { /* No entry for this symbol */ if (mode == LOOKING) return (struct symtab *) 0; /* * Make new entry */ p = (struct symtab *) malloc(sizeof *p); p->s_left = p->s_right = (struct symtab *) 0; p->s_name = malloc( (unsigned) (strlen(s) + 1)); strcpy(p->s_name,s); *table = p; return p; } else { p = *table; if ((n = strcmp(p->s_name,s)) == 0) { /* This is it! */ if (mode == ENTERING) { error("Identifier %s redefined",s); } return p; } /* Binary tree ..... */ if (n < 0) return findident(s,mode,&(p->s_left)); return findident(s,mode,&(p->s_right)); } /* NOTREACHED */ }