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Annotation of 40BSD/cmd/pi/lookup.c, revision 1.1

1.1     ! root        1: /* Copyright (c) 1979 Regents of the University of California */
        !             2: 
        !             3: static char sccsid[] = "@(#)lookup.c 1.1 8/27/80";
        !             4: 
        !             5: #include "whoami.h"
        !             6: #include "0.h"
        !             7: 
        !             8: /*
        !             9:  * Lookup is called to
        !            10:  * find a symbol in the
        !            11:  * block structure symbol
        !            12:  * table and returns a pointer to
        !            13:  * its namelist entry.
        !            14:  */
        !            15: struct nl *
        !            16: lookup(s)
        !            17:        register char *s;
        !            18: {
        !            19:        register struct nl *p;
        !            20:        register struct udinfo *udp;
        !            21: 
        !            22:        if (s == NIL) {
        !            23:                nocascade();
        !            24:                return (NIL);
        !            25:        }
        !            26:        p = lookup1(s);
        !            27:        if (p == NIL) {
        !            28:                derror("%s is undefined", s);
        !            29:                return (NIL);
        !            30:        }
        !            31:        if (p->class == FVAR) {
        !            32:                p = p->chain;
        !            33:                bn--;
        !            34:        }
        !            35:        return (p);
        !            36: }
        !            37: 
        !            38: #ifndef PI0
        !            39: int    flagwas;
        !            40: #endif
        !            41: /*
        !            42:  * Lookup1 is an internal lookup.
        !            43:  * It is not an error to call lookup1
        !            44:  * if the symbol is not defined.  Also
        !            45:  * lookup1 will return FVARs while
        !            46:  * lookup never will, thus asgnop
        !            47:  * calls it when it thinks you are
        !            48:  * assigning to the function variable.
        !            49:  */
        !            50: 
        !            51: struct nl *
        !            52: lookup1(s)
        !            53:        register char *s;
        !            54: {
        !            55:        register struct nl *p;
        !            56: #ifndef PI0
        !            57:        register struct nl *q;
        !            58: #endif
        !            59:        register int i;
        !            60: 
        !            61:        if (s == NIL)
        !            62:                return (NIL);
        !            63:        bn = cbn;
        !            64: #ifndef PI0
        !            65:        /*
        !            66:         * We first check the field names
        !            67:         * of the currently active with
        !            68:         * statements (expensive since they
        !            69:         * are not hashed).
        !            70:         */
        !            71:        for (p = withlist; p != NIL; p = p->nl_next) {
        !            72:                q = p->type;
        !            73:                if (q == NIL)
        !            74:                        continue;
        !            75:                if (reclook(q, s) != NIL)
        !            76:                        /*
        !            77:                         * Return the WITHPTR, lvalue understands.
        !            78:                         */
        !            79:                        return (p);
        !            80:        }
        !            81: #endif
        !            82:        /*
        !            83:         * Symbol table is a 64 way hash
        !            84:         * on the low bits of the character
        !            85:         * pointer value. (Simple, but effective)
        !            86:         */
        !            87:        i = (int) s & 077;
        !            88:        for (p = disptab[i]; p != NIL; p = p->nl_next)
        !            89:                if (p->symbol == s && p->class != FIELD && p->class != BADUSE) {
        !            90:                        bn = (p->nl_block & 037);
        !            91: #ifndef PI0
        !            92:                        flagwas = p->nl_flags;
        !            93:                        p->nl_flags |= NUSED;
        !            94: #endif
        !            95:                        return (p);
        !            96:                }
        !            97:        return (NIL);
        !            98: }
        !            99: 
        !           100: #ifndef PI01
        !           101: nlfund(sp)
        !           102:        char *sp;
        !           103: {
        !           104:        register struct nl *p;
        !           105:        register int i;
        !           106: 
        !           107:        i = (int) sp & 077;
        !           108:        for (p = disptab[i]; p != NIL; p = p->nl_next)
        !           109:        if (p->symbol == sp && (p->nl_block & 037) == 0)
        !           110:                return (nloff(p));
        !           111:        return (0);
        !           112: }
        !           113: #endif

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