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7f2935c7 | 1 | /* Part of CPP library. (Macro hash table support.) |
239d3342 | 2 | Copyright (C) 1986, 87, 89, 92-95, 1996 Free Software Foundation, Inc. |
7f2935c7 PB |
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 | |
6 | ||
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 | |
10 | later version. | |
11 | ||
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. | |
16 | ||
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 | |
940d9d63 | 19 | Foundation, 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. |
7f2935c7 PB |
20 | |
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! */ | |
24 | ||
b04cd507 KG |
25 | #include "config.h" |
26 | #include "system.h" | |
7f2935c7 PB |
27 | #include "cpplib.h" |
28 | #include "cpphash.h" | |
239d3342 | 29 | #include "gansidecl.h" |
7f2935c7 | 30 | |
02d0b8be RK |
31 | extern char *xmalloc PARAMS ((unsigned)); |
32 | ||
0f41302f MS |
33 | /* Return hash function on name. must be compatible with the one |
34 | computed a step at a time, elsewhere */ | |
35 | ||
7f2935c7 PB |
36 | int |
37 | hashf (name, len, hashsize) | |
38 | register const U_CHAR *name; | |
39 | register int len; | |
40 | int hashsize; | |
41 | { | |
42 | register int r = 0; | |
43 | ||
44 | while (len--) | |
45 | r = HASHSTEP (r, *name++); | |
46 | ||
47 | return MAKE_POS (r) % hashsize; | |
48 | } | |
49 | ||
0f41302f MS |
50 | /* Find the most recent hash node for name name (ending with first |
51 | non-identifier char) installed by install | |
52 | ||
53 | If LEN is >= 0, it is the length of the name. | |
54 | Otherwise, compute the length by scanning the entire name. | |
55 | ||
56 | If HASH is >= 0, it is the precomputed hash code. | |
57 | Otherwise, compute the hash code. */ | |
58 | ||
7f2935c7 PB |
59 | HASHNODE * |
60 | cpp_lookup (pfile, name, len, hash) | |
b23378c8 | 61 | cpp_reader *pfile; |
7f2935c7 PB |
62 | const U_CHAR *name; |
63 | int len; | |
64 | int hash; | |
65 | { | |
66 | register const U_CHAR *bp; | |
67 | register HASHNODE *bucket; | |
68 | ||
69 | if (len < 0) | |
70 | { | |
71 | for (bp = name; is_idchar[*bp]; bp++) ; | |
72 | len = bp - name; | |
73 | } | |
74 | ||
75 | if (hash < 0) | |
76 | hash = hashf (name, len, HASHSIZE); | |
77 | ||
78 | bucket = hashtab[hash]; | |
79 | while (bucket) { | |
80 | if (bucket->length == len && strncmp (bucket->name, name, len) == 0) | |
81 | return bucket; | |
82 | bucket = bucket->next; | |
83 | } | |
0f41302f | 84 | return (HASHNODE *) 0; |
7f2935c7 PB |
85 | } |
86 | ||
87 | /* | |
88 | * Delete a hash node. Some weirdness to free junk from macros. | |
89 | * More such weirdness will have to be added if you define more hash | |
90 | * types that need it. | |
91 | */ | |
92 | ||
93 | /* Note that the DEFINITION of a macro is removed from the hash table | |
94 | but its storage is not freed. This would be a storage leak | |
95 | except that it is not reasonable to keep undefining and redefining | |
96 | large numbers of macros many times. | |
97 | In any case, this is necessary, because a macro can be #undef'd | |
98 | in the middle of reading the arguments to a call to it. | |
99 | If #undef freed the DEFINITION, that would crash. */ | |
100 | ||
101 | void | |
102 | delete_macro (hp) | |
103 | HASHNODE *hp; | |
104 | { | |
105 | ||
106 | if (hp->prev != NULL) | |
107 | hp->prev->next = hp->next; | |
108 | if (hp->next != NULL) | |
109 | hp->next->prev = hp->prev; | |
110 | ||
111 | /* make sure that the bucket chain header that | |
0f41302f | 112 | the deleted guy was on points to the right thing afterwards. */ |
7f2935c7 PB |
113 | if (hp == *hp->bucket_hdr) |
114 | *hp->bucket_hdr = hp->next; | |
115 | ||
896fc322 PB |
116 | if (hp->type == T_MACRO) |
117 | { | |
118 | DEFINITION *d = hp->value.defn; | |
119 | struct reflist *ap, *nextap; | |
120 | ||
121 | for (ap = d->pattern; ap != NULL; ap = nextap) | |
122 | { | |
123 | nextap = ap->next; | |
124 | free (ap); | |
125 | } | |
126 | if (d->nargs >= 0) | |
127 | free (d->args.argnames); | |
128 | free (d); | |
7f2935c7 | 129 | } |
896fc322 | 130 | |
7f2935c7 PB |
131 | free (hp); |
132 | } | |
0f41302f MS |
133 | |
134 | /* Install a name in the main hash table, even if it is already there. | |
135 | name stops with first non alphanumeric, except leading '#'. | |
136 | caller must check against redefinition if that is desired. | |
137 | delete_macro () removes things installed by install () in fifo order. | |
138 | this is important because of the `defined' special symbol used | |
139 | in #if, and also if pushdef/popdef directives are ever implemented. | |
140 | ||
141 | If LEN is >= 0, it is the length of the name. | |
142 | Otherwise, compute the length by scanning the entire name. | |
143 | ||
144 | If HASH is >= 0, it is the precomputed hash code. | |
145 | Otherwise, compute the hash code. */ | |
146 | ||
7f2935c7 PB |
147 | HASHNODE * |
148 | install (name, len, type, ivalue, value, hash) | |
149 | U_CHAR *name; | |
150 | int len; | |
151 | enum node_type type; | |
152 | int ivalue; | |
153 | char *value; | |
154 | int hash; | |
155 | { | |
156 | register HASHNODE *hp; | |
157 | register int i, bucket; | |
158 | register U_CHAR *p, *q; | |
159 | ||
160 | if (len < 0) { | |
161 | p = name; | |
162 | while (is_idchar[*p]) | |
163 | p++; | |
164 | len = p - name; | |
165 | } | |
166 | ||
167 | if (hash < 0) | |
168 | hash = hashf (name, len, HASHSIZE); | |
169 | ||
170 | i = sizeof (HASHNODE) + len + 1; | |
171 | hp = (HASHNODE *) xmalloc (i); | |
172 | bucket = hash; | |
173 | hp->bucket_hdr = &hashtab[bucket]; | |
174 | hp->next = hashtab[bucket]; | |
175 | hashtab[bucket] = hp; | |
176 | hp->prev = NULL; | |
177 | if (hp->next != NULL) | |
178 | hp->next->prev = hp; | |
179 | hp->type = type; | |
180 | hp->length = len; | |
181 | if (hp->type == T_CONST) | |
182 | hp->value.ival = ivalue; | |
183 | else | |
184 | hp->value.cpval = value; | |
185 | hp->name = ((U_CHAR *) hp) + sizeof (HASHNODE); | |
186 | p = hp->name; | |
187 | q = name; | |
188 | for (i = 0; i < len; i++) | |
189 | *p++ = *q++; | |
190 | hp->name[len] = 0; | |
191 | return hp; | |
192 | } | |
896fc322 PB |
193 | |
194 | void | |
195 | cpp_hash_cleanup (pfile) | |
196 | cpp_reader *pfile; | |
197 | { | |
198 | register int i; | |
199 | for (i = HASHSIZE; --i >= 0; ) | |
200 | { | |
201 | while (hashtab[i]) | |
202 | delete_macro (hashtab[i]); | |
203 | } | |
204 | } |