usr.bin/rdist/lookup.c

/*
 * Copyright (c) 1983 Regents of the University of California.
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms are permitted
 * provided that the above copyright notice and this paragraph are
 * duplicated in all such forms and that any documentation,
 * advertising materials, and other materials related to such
 * distribution and use acknowledge that the software was developed
 * by the University of California, Berkeley.  The name of the
 * University may not be used to endorse or promote products derived
 * from this software without specific prior written permission.
 *
 * Copyright 2005 Sun Microsystems, Inc.  All rights reserved.
 * Use is subject to license terms.
 */
#pragma ident   "%Z%%M% %I% %E% SMI"

#include "defs.h"

    /* symbol types */
#define VAR 1
#define CONST   2

struct syment {
    int s_type;
    char    *s_name;
    struct  namelist *s_value;
    struct  syment *s_next;
};

static struct syment *hashtab[HASHSIZE];

/*
 * Define a variable from a command line argument.
 */
void
define(name)
    char *name;
{
    register char *cp, *s;
    register struct namelist *nl;
    struct namelist *value;

    if (debug)
        printf("define(%s)\n", name);

    cp = index(name, '=');
    if (cp == NULL)
        value = NULL;
    else if (cp[1] == '\0') {
        *cp = '\0';
        value = NULL;
    } else if (cp[1] != '(') {
        *cp++ = '\0';
        value = makenl(cp);
    } else {
        nl = NULL;
        *cp++ = '\0';
        do
            cp++;
        while (*cp == ' ' || *cp == '\t');
        for (s = cp; ; s++) {
            switch (*s) {
            case ')':
                *s = '\0';
            case '\0':
                break;
            case ' ':
            case '\t':
                *s++ = '\0';
                while (*s == ' ' || *s == '\t')
                    s++;
                if (*s == ')')
                    *s = '\0';
                break;
            default:
                continue;
            }
            if (nl == NULL)
                value = nl = makenl(cp);
            else {
                nl->n_next = makenl(cp);
                nl = nl->n_next;
            }
            if (*s == '\0')
                break;
            cp = s;
        }
    }
    (void) lookup(name, REPLACE, value);
}

/*
 * Lookup name in the table and return a pointer to it.
 * LOOKUP - just do lookup, return NULL if not found.
 * INSERT - insert name with value, error if already defined.
 * REPLACE - insert or replace name with value.
 */

struct namelist *
lookup(name, action, value)
    char *name;
    int action;
    struct namelist *value;
{
    register unsigned n;
    register char *cp;
    register struct syment *s;
    char buf[256];

    if (debug)
        printf("lookup(%s, %d, %x)\n", name, action, value);

    n = 0;
    for (cp = name; *cp; )
        n += *cp++;
    n %= HASHSIZE;

    for (s = hashtab[n]; s != NULL; s = s->s_next) {
        if (strcmp(name, s->s_name))
            continue;
        if (action != LOOKUP) {
            if (action != INSERT || s->s_type != CONST) {
                (void)sprintf(buf, "%.*s redefined",
                      sizeof(buf) - sizeof(" redefined"), name);
                yyerror(buf);
            }
        }
        return(s->s_value);
    }

    if (action == LOOKUP) {
        (void)sprintf(buf, "%.*s undefined",
            sizeof(buf) - sizeof(" undefined"), name);
        yyerror(buf);
        return(NULL);
    }

    s = ALLOC(syment);
    if (s == NULL)
        fatal("ran out of memory\n");
    s->s_next = hashtab[n];
    hashtab[n] = s;
    s->s_type = action == INSERT ? VAR : CONST;
    s->s_name = name;
    s->s_value = value;
    return(value);
}