[8833] | 1 | /* Part of CPP library. (Macro hash table support.) |
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| 2 | Copyright (C) 1986, 87, 89, 92, 93, 94, 1995 Free Software Foundation, Inc. |
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| 3 | Written by Per Bothner, 1994. |
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| 4 | Based on CCCP program by by Paul Rubin, June 1986 |
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| 5 | Adapted to ANSI C, Richard Stallman, Jan 1987 |
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| 6 | |
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| 7 | This program is free software; you can redistribute it and/or modify it |
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| 8 | under the terms of the GNU General Public License as published by the |
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| 9 | Free Software Foundation; either version 2, or (at your option) any |
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| 10 | later version. |
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| 11 | |
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| 12 | This program is distributed in the hope that it will be useful, |
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| 13 | but WITHOUT ANY WARRANTY; without even the implied warranty of |
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| 14 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
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| 15 | GNU General Public License for more details. |
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| 16 | |
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| 17 | You should have received a copy of the GNU General Public License |
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| 18 | along with this program; if not, write to the Free Software |
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| 19 | Foundation, 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. |
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| 20 | |
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| 21 | In other words, you are welcome to use, share and improve this program. |
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| 22 | You are forbidden to forbid anyone else to use, share and improve |
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| 23 | what you give them. Help stamp out software-hoarding! */ |
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| 24 | |
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| 25 | #include "cpplib.h" |
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| 26 | #include "cpphash.h" |
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| 27 | |
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| 28 | extern char *xmalloc PARAMS ((unsigned)); |
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| 29 | |
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| 30 | /* Define a generic NULL if one hasn't already been defined. */ |
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| 31 | |
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| 32 | #ifndef NULL |
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| 33 | #define NULL 0 |
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| 34 | #endif |
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| 35 | |
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| 36 | #ifndef __STDC__ |
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| 37 | #define const |
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| 38 | #define volatile |
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| 39 | #endif |
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| 40 | |
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| 41 | /* |
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| 42 | * return hash function on name. must be compatible with the one |
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| 43 | * computed a step at a time, elsewhere |
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| 44 | */ |
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| 45 | int |
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| 46 | hashf (name, len, hashsize) |
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| 47 | register const U_CHAR *name; |
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| 48 | register int len; |
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| 49 | int hashsize; |
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| 50 | { |
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| 51 | register int r = 0; |
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| 52 | |
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| 53 | while (len--) |
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| 54 | r = HASHSTEP (r, *name++); |
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| 55 | |
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| 56 | return MAKE_POS (r) % hashsize; |
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| 57 | } |
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| 58 | |
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| 59 | /* |
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| 60 | * find the most recent hash node for name name (ending with first |
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| 61 | * non-identifier char) installed by install |
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| 62 | * |
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| 63 | * If LEN is >= 0, it is the length of the name. |
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| 64 | * Otherwise, compute the length by scanning the entire name. |
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| 65 | * |
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| 66 | * If HASH is >= 0, it is the precomputed hash code. |
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| 67 | * Otherwise, compute the hash code. |
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| 68 | */ |
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| 69 | HASHNODE * |
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| 70 | cpp_lookup (pfile, name, len, hash) |
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| 71 | struct parse_file *pfile; |
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| 72 | const U_CHAR *name; |
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| 73 | int len; |
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| 74 | int hash; |
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| 75 | { |
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| 76 | register const U_CHAR *bp; |
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| 77 | register HASHNODE *bucket; |
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| 78 | |
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| 79 | if (len < 0) |
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| 80 | { |
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| 81 | for (bp = name; is_idchar[*bp]; bp++) ; |
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| 82 | len = bp - name; |
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| 83 | } |
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| 84 | |
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| 85 | if (hash < 0) |
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| 86 | hash = hashf (name, len, HASHSIZE); |
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| 87 | |
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| 88 | bucket = hashtab[hash]; |
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| 89 | while (bucket) { |
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| 90 | if (bucket->length == len && strncmp (bucket->name, name, len) == 0) |
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| 91 | return bucket; |
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| 92 | bucket = bucket->next; |
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| 93 | } |
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| 94 | return (HASHNODE*) 0; |
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| 95 | } |
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| 96 | |
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| 97 | /* |
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| 98 | * Delete a hash node. Some weirdness to free junk from macros. |
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| 99 | * More such weirdness will have to be added if you define more hash |
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| 100 | * types that need it. |
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| 101 | */ |
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| 102 | |
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| 103 | /* Note that the DEFINITION of a macro is removed from the hash table |
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| 104 | but its storage is not freed. This would be a storage leak |
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| 105 | except that it is not reasonable to keep undefining and redefining |
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| 106 | large numbers of macros many times. |
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| 107 | In any case, this is necessary, because a macro can be #undef'd |
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| 108 | in the middle of reading the arguments to a call to it. |
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| 109 | If #undef freed the DEFINITION, that would crash. */ |
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| 110 | |
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| 111 | void |
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| 112 | delete_macro (hp) |
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| 113 | HASHNODE *hp; |
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| 114 | { |
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| 115 | |
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| 116 | if (hp->prev != NULL) |
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| 117 | hp->prev->next = hp->next; |
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| 118 | if (hp->next != NULL) |
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| 119 | hp->next->prev = hp->prev; |
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| 120 | |
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| 121 | /* make sure that the bucket chain header that |
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| 122 | the deleted guy was on points to the right thing afterwards. */ |
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| 123 | if (hp == *hp->bucket_hdr) |
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| 124 | *hp->bucket_hdr = hp->next; |
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| 125 | |
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| 126 | if (hp->type == T_MACRO) |
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| 127 | { |
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| 128 | DEFINITION *d = hp->value.defn; |
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| 129 | struct reflist *ap, *nextap; |
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| 130 | |
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| 131 | for (ap = d->pattern; ap != NULL; ap = nextap) |
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| 132 | { |
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| 133 | nextap = ap->next; |
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| 134 | free (ap); |
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| 135 | } |
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| 136 | if (d->nargs >= 0) |
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| 137 | free (d->args.argnames); |
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| 138 | free (d); |
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| 139 | } |
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| 140 | |
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| 141 | free (hp); |
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| 142 | } |
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| 143 | /* |
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| 144 | * install a name in the main hash table, even if it is already there. |
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| 145 | * name stops with first non alphanumeric, except leading '#'. |
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| 146 | * caller must check against redefinition if that is desired. |
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| 147 | * delete_macro () removes things installed by install () in fifo order. |
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| 148 | * this is important because of the `defined' special symbol used |
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| 149 | * in #if, and also if pushdef/popdef directives are ever implemented. |
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| 150 | * |
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| 151 | * If LEN is >= 0, it is the length of the name. |
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| 152 | * Otherwise, compute the length by scanning the entire name. |
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| 153 | * |
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| 154 | * If HASH is >= 0, it is the precomputed hash code. |
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| 155 | * Otherwise, compute the hash code. |
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| 156 | */ |
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| 157 | HASHNODE * |
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| 158 | install (name, len, type, ivalue, value, hash) |
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| 159 | U_CHAR *name; |
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| 160 | int len; |
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| 161 | enum node_type type; |
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| 162 | int ivalue; |
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| 163 | char *value; |
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| 164 | int hash; |
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| 165 | { |
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| 166 | register HASHNODE *hp; |
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| 167 | register int i, bucket; |
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| 168 | register U_CHAR *p, *q; |
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| 169 | |
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| 170 | if (len < 0) { |
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| 171 | p = name; |
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| 172 | while (is_idchar[*p]) |
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| 173 | p++; |
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| 174 | len = p - name; |
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| 175 | } |
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| 176 | |
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| 177 | if (hash < 0) |
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| 178 | hash = hashf (name, len, HASHSIZE); |
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| 179 | |
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| 180 | i = sizeof (HASHNODE) + len + 1; |
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| 181 | hp = (HASHNODE *) xmalloc (i); |
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| 182 | bucket = hash; |
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| 183 | hp->bucket_hdr = &hashtab[bucket]; |
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| 184 | hp->next = hashtab[bucket]; |
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| 185 | hashtab[bucket] = hp; |
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| 186 | hp->prev = NULL; |
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| 187 | if (hp->next != NULL) |
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| 188 | hp->next->prev = hp; |
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| 189 | hp->type = type; |
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| 190 | hp->length = len; |
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| 191 | if (hp->type == T_CONST) |
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| 192 | hp->value.ival = ivalue; |
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| 193 | else |
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| 194 | hp->value.cpval = value; |
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| 195 | hp->name = ((U_CHAR *) hp) + sizeof (HASHNODE); |
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| 196 | p = hp->name; |
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| 197 | q = name; |
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| 198 | for (i = 0; i < len; i++) |
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| 199 | *p++ = *q++; |
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| 200 | hp->name[len] = 0; |
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| 201 | return hp; |
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| 202 | } |
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| 203 | |
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| 204 | void |
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| 205 | cpp_hash_cleanup (pfile) |
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| 206 | cpp_reader *pfile; |
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| 207 | { |
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| 208 | register int i; |
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| 209 | for (i = HASHSIZE; --i >= 0; ) |
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| 210 | { |
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| 211 | while (hashtab[i]) |
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| 212 | delete_macro (hashtab[i]); |
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| 213 | } |
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| 214 | } |
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