Annotation of 43BSDReno/pgrm/pascal/src/lookup.c, revision 1.1

1.1     ! root        1: /*
        !             2:  * Copyright (c) 1980 Regents of the University of California.
        !             3:  * All rights reserved.  The Berkeley software License Agreement
        !             4:  * specifies the terms and conditions for redistribution.
        !             5:  */
        !             6: 
        !             7: #ifndef lint
        !             8: static char sccsid[] = "@(#)lookup.c   5.1 (Berkeley) 6/5/85";
        !             9: #endif not lint
        !            10: 
        !            11: #include "whoami.h"
        !            12: #include "0.h"
        !            13: 
        !            14: struct nl *disptab[077+1];
        !            15: 
        !            16: /*
        !            17:  * Lookup is called to
        !            18:  * find a symbol in the
        !            19:  * block structure symbol
        !            20:  * table and returns a pointer to
        !            21:  * its namelist entry.
        !            22:  */
        !            23: struct nl *
        !            24: lookup(s)
        !            25:        register char *s;
        !            26: {
        !            27:        register struct nl *p;
        !            28:        register struct udinfo;
        !            29: 
        !            30:        if (s == NIL) {
        !            31:                nocascade();
        !            32:                return (NLNIL);
        !            33:        }
        !            34:        p = lookup1(s);
        !            35:        if (p == NLNIL) {
        !            36:                derror("%s is undefined", s);
        !            37:                return (NLNIL);
        !            38:        }
        !            39:        if (p->class == FVAR) {
        !            40:                p = p->chain;
        !            41:                bn--;
        !            42:        }
        !            43:        return (p);
        !            44: }
        !            45: 
        !            46: #ifndef PI0
        !            47: int    flagwas;
        !            48: #endif
        !            49: /*
        !            50:  * Lookup1 is an internal lookup.
        !            51:  * It is not an error to call lookup1
        !            52:  * if the symbol is not defined.  Also
        !            53:  * lookup1 will return FVARs while
        !            54:  * lookup never will, thus asgnop
        !            55:  * calls it when it thinks you are
        !            56:  * assigning to the function variable.
        !            57:  */
        !            58: 
        !            59: struct nl *
        !            60: lookup1(s)
        !            61:        register char *s;
        !            62: {
        !            63:        register struct nl *p;
        !            64: #ifndef PI0
        !            65:        register struct nl *q;
        !            66: #endif
        !            67:        register int i;
        !            68: 
        !            69:        if (s == NIL)
        !            70:                return (NLNIL);
        !            71:        bn = cbn;
        !            72: #ifndef PI0
        !            73:        /*
        !            74:         * We first check the field names
        !            75:         * of the currently active with
        !            76:         * statements (expensive since they
        !            77:         * are not hashed).
        !            78:         */
        !            79:        for (p = withlist; p != NLNIL; p = p->nl_next) {
        !            80:                q = p->type;
        !            81:                if (q == NLNIL)
        !            82:                        continue;
        !            83:                if (reclook(q, s) != NIL)
        !            84:                        /*
        !            85:                         * Return the WITHPTR, lvalue understands.
        !            86:                         */
        !            87:                        return (p);
        !            88:        }
        !            89: #endif
        !            90:        /*
        !            91:         * Symbol table is a 64 way hash
        !            92:         * on the low bits of the character
        !            93:         * pointer value. (Simple, but effective)
        !            94:         */
        !            95:        i = (int) s & 077;
        !            96:        for (p = disptab[i]; p != NLNIL; p = p->nl_next)
        !            97:                if (p->symbol == s && p->class != FIELD && p->class != BADUSE) {
        !            98:                        bn = (p->nl_block & 037);
        !            99: #ifndef PI0
        !           100:                        flagwas = p->nl_flags;
        !           101:                        p->nl_flags |= NUSED;
        !           102: #endif
        !           103:                        return (p);
        !           104:                }
        !           105:        return (NLNIL);
        !           106: }
        !           107: 
        !           108: #ifndef PI01
        !           109: nlfund(sp)
        !           110:        char *sp;
        !           111: {
        !           112:        register struct nl *p;
        !           113:        register int i;
        !           114: 
        !           115:        i = (int) sp & 077;
        !           116:        for (p = disptab[i]; p != NLNIL; p = p->nl_next)
        !           117:        if (p->symbol == sp && (p->nl_block & 037) == 0)
        !           118:                return (nloff(p));
        !           119:        return (0);
        !           120: }
        !           121: #endif

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