1 /* Part of CPP library. (Macro hash table support.)
2 Copyright (C) 1986, 87, 89, 92, 93, 94, 1995 Free Software Foundation, Inc.
3 Written by Per Bothner, 1994.
4 Based on CCCP program by by Paul Rubin, June 1986
5 Adapted to ANSI C, Richard Stallman, Jan 1987
7 This program is free software; you can redistribute it and/or modify it
8 under the terms of the GNU General Public License as published by the
9 Free Software Foundation; either version 2, or (at your option) any
12 This program is distributed in the hope that it will be useful,
13 but WITHOUT ANY WARRANTY; without even the implied warranty of
14 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 GNU General Public License for more details.
17 You should have received a copy of the GNU General Public License
18 along with this program; if not, write to the Free Software
19 Foundation, 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
21 In other words, you are welcome to use, share and improve this program.
22 You are forbidden to forbid anyone else to use, share and improve
23 what you give them. Help stamp out software-hoarding! */
27 //extern char *xmalloc PARAMS ((unsigned));
34 /* Define a generic NULL if one hasn't already been defined. */
45 static HASHNODE *hashtab[HASHSIZE];
48 * return hash function on name. must be compatible with the one
49 * computed a step at a time, elsewhere
53 register const U_CHAR *name,
60 r = HASHSTEP (r, *name++);
62 return MAKE_POS (r) % hashsize;
66 * find the most recent hash node for name name (ending with first
67 * non-identifier char) installed by install
69 * If LEN is >= 0, it is the length of the name.
70 * Otherwise, compute the length by scanning the entire name.
72 * If HASH is >= 0, it is the precomputed hash code.
73 * Otherwise, compute the hash code.
77 struct parse_file *pfile,
82 register const U_CHAR *bp;
83 register HASHNODE *bucket;
87 for (bp = name; is_idchar[*bp]; bp++) ;
92 hash = hashf (name, len, HASHSIZE);
94 bucket = hashtab[hash];
96 if (bucket->length == len && strncmp (bucket->name, name, len) == 0)
98 bucket = bucket->next;
100 return (HASHNODE*) 0;
104 * Delete a hash node. Some weirdness to free junk from macros.
105 * More such weirdness will have to be added if you define more hash
106 * types that need it.
109 /* Note that the DEFINITION of a macro is removed from the hash table
110 but its storage is not freed. This would be a storage leak
111 except that it is not reasonable to keep undefining and redefining
112 large numbers of macros many times.
113 In any case, this is necessary, because a macro can be #undef'd
114 in the middle of reading the arguments to a call to it.
115 If #undef freed the DEFINITION, that would crash. */
122 if (hp->prev != NULL)
123 hp->prev->next = hp->next;
124 if (hp->next != NULL)
125 hp->next->prev = hp->prev;
127 /* make sure that the bucket chain header that
128 the deleted guy was on points to the right thing afterwards. */
129 if (hp == *hp->bucket_hdr)
130 *hp->bucket_hdr = hp->next;
132 if (hp->type == T_MACRO)
134 DEFINITION *d = hp->value.defn;
135 struct reflist *ap, *nextap;
137 for (ap = d->pattern; ap != NULL; ap = nextap)
143 free (d->args.argnames);
150 * install a name in the main hash table, even if it is already there.
151 * name stops with first non alphanumeric, except leading '#'.
152 * caller must check against redefinition if that is desired.
153 * delete_macro () removes things installed by install () in fifo order.
154 * this is important because of the `defined' special symbol used
155 * in #if, and also if pushdef/popdef directives are ever implemented.
157 * If LEN is >= 0, it is the length of the name.
158 * Otherwise, compute the length by scanning the entire name.
160 * If HASH is >= 0, it is the precomputed hash code.
161 * Otherwise, compute the hash code.
172 register HASHNODE *hp;
173 register int i, bucket;
174 register U_CHAR *p, *q;
178 while (is_idchar[*p])
184 hash = hashf (name, len, HASHSIZE);
186 i = sizeof (HASHNODE) + len + 1;
187 hp = (HASHNODE *) Safe_malloc (i);
189 hp->bucket_hdr = &hashtab[bucket];
190 hp->next = hashtab[bucket];
191 hashtab[bucket] = hp;
193 if (hp->next != NULL)
197 if (hp->type == T_CONST)
198 hp->value.ival = ivalue;
200 hp->value.cpval = value;
201 hp->name = ((U_CHAR *) hp) + sizeof (HASHNODE);
204 for (i = 0; i < len; i++)
215 for (i = HASHSIZE; --i >= 0; )
218 delete_macro (hashtab[i]);