| 1 | #ifndef lint |
| 2 | static char *sccsid = "@(#)lookup.c 4.2 (Berkeley) 83/09/27"; |
| 3 | #endif |
| 4 | |
| 5 | #include "defs.h" |
| 6 | |
| 7 | /* |
| 8 | * Define a variable from a command line argument. |
| 9 | */ |
| 10 | define(name) |
| 11 | char *name; |
| 12 | { |
| 13 | register char *cp, *s; |
| 14 | register struct block *bp, *value; |
| 15 | |
| 16 | if (debug) |
| 17 | printf("define(%s)\n", name); |
| 18 | |
| 19 | cp = index(name, '='); |
| 20 | if (cp == NULL || cp[1] == '\0') |
| 21 | value = NULL; |
| 22 | else if (cp[1] != '(') { |
| 23 | *cp++ = '\0'; |
| 24 | value = makeblock(NAME, cp); |
| 25 | } else { |
| 26 | bp = NULL; |
| 27 | *cp++ = '\0'; |
| 28 | do |
| 29 | cp++; |
| 30 | while (*cp == ' ' || *cp == '\t'); |
| 31 | for (s = cp; ; s++) { |
| 32 | switch (*s) { |
| 33 | case ')': |
| 34 | *s = '\0'; |
| 35 | case '\0': |
| 36 | break; |
| 37 | case ' ': |
| 38 | case '\t': |
| 39 | *s++ = '\0'; |
| 40 | while (*s == ' ' || *s == '\t') |
| 41 | s++; |
| 42 | if (*s == ')') |
| 43 | *s = '\0'; |
| 44 | break; |
| 45 | default: |
| 46 | continue; |
| 47 | } |
| 48 | if (bp == NULL) |
| 49 | value = bp = makeblock(NAME, cp); |
| 50 | else { |
| 51 | bp->b_next = makeblock(NAME, cp); |
| 52 | bp = bp->b_next; |
| 53 | } |
| 54 | if (*s == '\0') |
| 55 | break; |
| 56 | cp = s; |
| 57 | } |
| 58 | } |
| 59 | bp = makeblock(VAR, name); |
| 60 | bp->b_args = value; |
| 61 | (void) lookup(bp->b_name, bp, 1); |
| 62 | } |
| 63 | |
| 64 | static struct block *hashtab[HASHSIZE]; |
| 65 | |
| 66 | /* |
| 67 | * Lookup name in the table and return a pointer to it. |
| 68 | * Insert == 0 - just do lookup, return NULL if not found. |
| 69 | * insert == 1 - insert name with value, error if already defined. |
| 70 | * insert == 2 - replace name with value if not entered with insert == 1. |
| 71 | */ |
| 72 | |
| 73 | struct block * |
| 74 | lookup(name, value, insert) |
| 75 | char *name; |
| 76 | struct block *value; |
| 77 | int insert; |
| 78 | { |
| 79 | register unsigned n; |
| 80 | register char *cp; |
| 81 | register struct block *b, *f; |
| 82 | |
| 83 | if (debug) |
| 84 | printf("lookup(%s, %x, %d)\n", name, value, insert); |
| 85 | |
| 86 | n = 0; |
| 87 | for (cp = name; *cp; ) |
| 88 | n += *cp++; |
| 89 | n %= HASHSIZE; |
| 90 | |
| 91 | for (b = hashtab[n]; b != NULL; b = b->b_next) { |
| 92 | if (strcmp(name, b->b_name)) |
| 93 | continue; |
| 94 | if (insert) { |
| 95 | if (b->b_type == NAME) { |
| 96 | warn("%s redefined\n", name); |
| 97 | f = b->b_args; |
| 98 | b->b_args = value->b_args; |
| 99 | value->b_args = f; |
| 100 | } else if (value->b_type == VAR) |
| 101 | fatal("%s redefined\n", name); |
| 102 | while (f = value->b_next) { |
| 103 | value->b_next = f->b_next; |
| 104 | free(f->b_name); |
| 105 | free(f); |
| 106 | } |
| 107 | free(value->b_name); |
| 108 | free(value); |
| 109 | } |
| 110 | return(b); |
| 111 | } |
| 112 | |
| 113 | if (!insert) |
| 114 | fatal("%s not defined", name); |
| 115 | |
| 116 | value->b_next = hashtab[n]; |
| 117 | hashtab[n] = value; |
| 118 | return(value); |
| 119 | } |
| 120 | |
| 121 | /* |
| 122 | * Make a block for lists of variables, commands, etc. |
| 123 | */ |
| 124 | struct block * |
| 125 | makeblock(type, name) |
| 126 | int type; |
| 127 | register char *name; |
| 128 | { |
| 129 | register char *cp; |
| 130 | register struct block *bp; |
| 131 | |
| 132 | bp = ALLOC(block); |
| 133 | if (bp == NULL) |
| 134 | fatal("ran out of memory\n"); |
| 135 | bp->b_type = type; |
| 136 | bp->b_next = bp->b_args = NULL; |
| 137 | if (type == NAME || type == VAR) { |
| 138 | bp->b_name = cp = (char *) malloc(strlen(name) + 1); |
| 139 | if (cp == NULL) |
| 140 | fatal("ran out of memory\n"); |
| 141 | while (*cp++ = *name++) |
| 142 | ; |
| 143 | } else |
| 144 | bp->b_name = NULL; |
| 145 | return(bp); |
| 146 | } |