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f11c3779 | 1 | /* Traits for hashable types. |
a5544970 | 2 | Copyright (C) 2014-2019 Free Software Foundation, Inc. |
f11c3779 RS |
3 | |
4 | This file is part of GCC. | |
5 | ||
6 | GCC is free software; you can redistribute it and/or modify it under | |
7 | the terms of the GNU General Public License as published by the Free | |
8 | Software Foundation; either version 3, or (at your option) any later | |
9 | version. | |
10 | ||
11 | GCC is distributed in the hope that it will be useful, but WITHOUT ANY | |
12 | WARRANTY; without even the implied warranty of MERCHANTABILITY or | |
13 | FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License | |
14 | for more details. | |
15 | ||
16 | You should have received a copy of the GNU General Public License | |
17 | along with GCC; see the file COPYING3. If not see | |
18 | <http://www.gnu.org/licenses/>. */ | |
19 | ||
20 | #ifndef hash_traits_h | |
21 | #define hash_traits_h | |
22 | ||
23 | /* Helpful type for removing with free. */ | |
24 | ||
25 | template <typename Type> | |
26 | struct typed_free_remove | |
27 | { | |
28 | static inline void remove (Type *p); | |
29 | }; | |
30 | ||
31 | ||
32 | /* Remove with free. */ | |
33 | ||
34 | template <typename Type> | |
35 | inline void | |
36 | typed_free_remove <Type>::remove (Type *p) | |
37 | { | |
38 | free (p); | |
39 | } | |
40 | ||
74fbae92 ML |
41 | /* Helpful type for removing with delete. */ |
42 | ||
43 | template <typename Type> | |
44 | struct typed_delete_remove | |
45 | { | |
46 | static inline void remove (Type *p); | |
47 | }; | |
48 | ||
49 | ||
50 | /* Remove with delete. */ | |
51 | ||
52 | template <typename Type> | |
53 | inline void | |
54 | typed_delete_remove <Type>::remove (Type *p) | |
55 | { | |
56 | delete p; | |
57 | } | |
f11c3779 RS |
58 | |
59 | /* Helpful type for a no-op remove. */ | |
60 | ||
61 | template <typename Type> | |
62 | struct typed_noop_remove | |
63 | { | |
fc17926a | 64 | static inline void remove (Type &); |
f11c3779 RS |
65 | }; |
66 | ||
67 | ||
68 | /* Remove doing nothing. */ | |
69 | ||
70 | template <typename Type> | |
71 | inline void | |
fc17926a | 72 | typed_noop_remove <Type>::remove (Type &) |
f11c3779 RS |
73 | { |
74 | } | |
75 | ||
76 | ||
e0702244 RS |
77 | /* Hasher for integer type Type in which Empty is a spare value that can be |
78 | used to mark empty slots. If Deleted != Empty then Deleted is another | |
79 | spare value that can be used for deleted slots; if Deleted == Empty then | |
80 | hash table entries cannot be deleted. */ | |
81 | ||
82 | template <typename Type, Type Empty, Type Deleted = Empty> | |
83 | struct int_hash : typed_noop_remove <Type> | |
84 | { | |
85 | typedef Type value_type; | |
86 | typedef Type compare_type; | |
87 | ||
88 | static inline hashval_t hash (value_type); | |
89 | static inline bool equal (value_type existing, value_type candidate); | |
90 | static inline void mark_deleted (Type &); | |
91 | static inline void mark_empty (Type &); | |
92 | static inline bool is_deleted (Type); | |
93 | static inline bool is_empty (Type); | |
94 | }; | |
95 | ||
96 | template <typename Type, Type Empty, Type Deleted> | |
97 | inline hashval_t | |
98 | int_hash <Type, Empty, Deleted>::hash (value_type x) | |
99 | { | |
100 | return x; | |
101 | } | |
102 | ||
103 | template <typename Type, Type Empty, Type Deleted> | |
104 | inline bool | |
105 | int_hash <Type, Empty, Deleted>::equal (value_type x, value_type y) | |
106 | { | |
107 | return x == y; | |
108 | } | |
109 | ||
110 | template <typename Type, Type Empty, Type Deleted> | |
111 | inline void | |
112 | int_hash <Type, Empty, Deleted>::mark_deleted (Type &x) | |
113 | { | |
114 | gcc_assert (Empty != Deleted); | |
115 | x = Deleted; | |
116 | } | |
117 | ||
118 | template <typename Type, Type Empty, Type Deleted> | |
119 | inline void | |
120 | int_hash <Type, Empty, Deleted>::mark_empty (Type &x) | |
121 | { | |
122 | x = Empty; | |
123 | } | |
124 | ||
125 | template <typename Type, Type Empty, Type Deleted> | |
126 | inline bool | |
127 | int_hash <Type, Empty, Deleted>::is_deleted (Type x) | |
128 | { | |
129 | return Empty != Deleted && x == Deleted; | |
130 | } | |
131 | ||
132 | template <typename Type, Type Empty, Type Deleted> | |
133 | inline bool | |
134 | int_hash <Type, Empty, Deleted>::is_empty (Type x) | |
135 | { | |
136 | return x == Empty; | |
137 | } | |
138 | ||
8d67ee55 RS |
139 | /* Pointer hasher based on pointer equality. Other types of pointer hash |
140 | can inherit this and override the hash and equal functions with some | |
141 | other form of equality (such as string equality). */ | |
f11c3779 RS |
142 | |
143 | template <typename Type> | |
8d67ee55 | 144 | struct pointer_hash |
f11c3779 RS |
145 | { |
146 | typedef Type *value_type; | |
147 | typedef Type *compare_type; | |
148 | ||
149 | static inline hashval_t hash (const value_type &); | |
f11c3779 RS |
150 | static inline bool equal (const value_type &existing, |
151 | const compare_type &candidate); | |
843adf88 RS |
152 | static inline void mark_deleted (Type *&); |
153 | static inline void mark_empty (Type *&); | |
154 | static inline bool is_deleted (Type *); | |
155 | static inline bool is_empty (Type *); | |
f11c3779 RS |
156 | }; |
157 | ||
158 | template <typename Type> | |
159 | inline hashval_t | |
160 | pointer_hash <Type>::hash (const value_type &candidate) | |
161 | { | |
162 | /* This is a really poor hash function, but it is what the current code uses, | |
163 | so I am reusing it to avoid an additional axis in testing. */ | |
164 | return (hashval_t) ((intptr_t)candidate >> 3); | |
165 | } | |
166 | ||
167 | template <typename Type> | |
168 | inline bool | |
169 | pointer_hash <Type>::equal (const value_type &existing, | |
170 | const compare_type &candidate) | |
171 | { | |
172 | return existing == candidate; | |
173 | } | |
174 | ||
843adf88 RS |
175 | template <typename Type> |
176 | inline void | |
177 | pointer_hash <Type>::mark_deleted (Type *&e) | |
178 | { | |
179 | e = reinterpret_cast<Type *> (1); | |
180 | } | |
181 | ||
182 | template <typename Type> | |
183 | inline void | |
184 | pointer_hash <Type>::mark_empty (Type *&e) | |
185 | { | |
186 | e = NULL; | |
187 | } | |
188 | ||
189 | template <typename Type> | |
190 | inline bool | |
191 | pointer_hash <Type>::is_deleted (Type *e) | |
192 | { | |
193 | return e == reinterpret_cast<Type *> (1); | |
194 | } | |
195 | ||
196 | template <typename Type> | |
197 | inline bool | |
198 | pointer_hash <Type>::is_empty (Type *e) | |
199 | { | |
200 | return e == NULL; | |
201 | } | |
202 | ||
20d2c372 RS |
203 | /* Hasher for "const char *" strings, using string rather than pointer |
204 | equality. */ | |
205 | ||
206 | struct string_hash : pointer_hash <const char> | |
207 | { | |
208 | static inline hashval_t hash (const char *); | |
209 | static inline bool equal (const char *, const char *); | |
210 | }; | |
211 | ||
212 | inline hashval_t | |
213 | string_hash::hash (const char *id) | |
214 | { | |
215 | return htab_hash_string (id); | |
216 | } | |
217 | ||
218 | inline bool | |
219 | string_hash::equal (const char *id1, const char *id2) | |
220 | { | |
221 | return strcmp (id1, id2) == 0; | |
222 | } | |
223 | ||
ca752f39 | 224 | /* Remover and marker for entries in gc memory. */ |
f11c3779 RS |
225 | |
226 | template<typename T> | |
ca752f39 | 227 | struct ggc_remove |
f11c3779 | 228 | { |
5ac6389b | 229 | static void remove (T &) {} |
f11c3779 RS |
230 | |
231 | static void | |
5ac6389b | 232 | ggc_mx (T &p) |
f11c3779 RS |
233 | { |
234 | extern void gt_ggc_mx (T &); | |
235 | gt_ggc_mx (p); | |
236 | } | |
237 | ||
21faa101 JM |
238 | /* Overridden in ggc_cache_remove. */ |
239 | static void | |
240 | ggc_maybe_mx (T &p) | |
241 | { | |
242 | ggc_mx (p); | |
243 | } | |
244 | ||
f11c3779 RS |
245 | static void |
246 | pch_nx (T &p) | |
247 | { | |
248 | extern void gt_pch_nx (T &); | |
249 | gt_pch_nx (p); | |
250 | } | |
251 | ||
252 | static void | |
253 | pch_nx (T &p, gt_pointer_operator op, void *cookie) | |
254 | { | |
255 | op (&p, cookie); | |
256 | } | |
257 | }; | |
258 | ||
6c907cff RS |
259 | /* Remover and marker for "cache" entries in gc memory. These entries can |
260 | be deleted if there are no non-cache references to the data. */ | |
f11c3779 RS |
261 | |
262 | template<typename T> | |
6c907cff | 263 | struct ggc_cache_remove : ggc_remove<T> |
f11c3779 | 264 | { |
f11c3779 | 265 | /* Entries are weakly held because this is for caches. */ |
21faa101 | 266 | static void ggc_maybe_mx (T &) {} |
f11c3779 | 267 | |
08ec2754 RS |
268 | static int |
269 | keep_cache_entry (T &e) | |
f11c3779 | 270 | { |
08ec2754 | 271 | return ggc_marked_p (e) ? -1 : 0; |
f11c3779 RS |
272 | } |
273 | }; | |
274 | ||
8d67ee55 RS |
275 | /* Traits for pointer elements that should not be freed when an element |
276 | is deleted. */ | |
277 | ||
278 | template <typename T> | |
fc17926a | 279 | struct nofree_ptr_hash : pointer_hash <T>, typed_noop_remove <T *> {}; |
8d67ee55 | 280 | |
95fbe13e RS |
281 | /* Traits for pointer elements that should be freed via free() when an |
282 | element is deleted. */ | |
283 | ||
284 | template <typename T> | |
285 | struct free_ptr_hash : pointer_hash <T>, typed_free_remove <T> {}; | |
286 | ||
74fbae92 ML |
287 | /* Traits for pointer elements that should be freed via delete operand when an |
288 | element is deleted. */ | |
289 | ||
290 | template <typename T> | |
291 | struct delete_ptr_hash : pointer_hash <T>, typed_delete_remove <T> {}; | |
292 | ||
ca752f39 RS |
293 | /* Traits for elements that point to gc memory. The pointed-to data |
294 | must be kept across collections. */ | |
295 | ||
296 | template <typename T> | |
297 | struct ggc_ptr_hash : pointer_hash <T>, ggc_remove <T *> {}; | |
298 | ||
6c907cff RS |
299 | /* Traits for elements that point to gc memory. The elements don't |
300 | in themselves keep the pointed-to data alive and they can be deleted | |
301 | if the pointed-to data is going to be collected. */ | |
302 | ||
303 | template <typename T> | |
304 | struct ggc_cache_ptr_hash : pointer_hash <T>, ggc_cache_remove <T *> {}; | |
305 | ||
20d2c372 RS |
306 | /* Traits for string elements that should not be freed when an element |
307 | is deleted. */ | |
308 | ||
309 | struct nofree_string_hash : string_hash, typed_noop_remove <const char *> {}; | |
310 | ||
9adee305 RS |
311 | /* Traits for pairs of values, using the first to record empty and |
312 | deleted slots. */ | |
313 | ||
314 | template <typename T1, typename T2> | |
315 | struct pair_hash | |
316 | { | |
317 | typedef std::pair <typename T1::value_type, | |
318 | typename T2::value_type> value_type; | |
319 | typedef std::pair <typename T1::compare_type, | |
320 | typename T2::compare_type> compare_type; | |
321 | ||
322 | static inline hashval_t hash (const value_type &); | |
323 | static inline bool equal (const value_type &, const compare_type &); | |
324 | static inline void remove (value_type &); | |
325 | static inline void mark_deleted (value_type &); | |
326 | static inline void mark_empty (value_type &); | |
327 | static inline bool is_deleted (const value_type &); | |
328 | static inline bool is_empty (const value_type &); | |
329 | }; | |
330 | ||
331 | template <typename T1, typename T2> | |
332 | inline hashval_t | |
333 | pair_hash <T1, T2>::hash (const value_type &x) | |
334 | { | |
335 | return iterative_hash_hashval_t (T1::hash (x.first), T2::hash (x.second)); | |
336 | } | |
337 | ||
338 | template <typename T1, typename T2> | |
339 | inline bool | |
340 | pair_hash <T1, T2>::equal (const value_type &x, const compare_type &y) | |
341 | { | |
342 | return T1::equal (x.first, y.first) && T2::equal (x.second, y.second); | |
343 | } | |
344 | ||
345 | template <typename T1, typename T2> | |
346 | inline void | |
347 | pair_hash <T1, T2>::remove (value_type &x) | |
348 | { | |
349 | T1::remove (x.first); | |
350 | T2::remove (x.second); | |
351 | } | |
352 | ||
353 | template <typename T1, typename T2> | |
354 | inline void | |
355 | pair_hash <T1, T2>::mark_deleted (value_type &x) | |
356 | { | |
357 | T1::mark_deleted (x.first); | |
358 | } | |
359 | ||
360 | template <typename T1, typename T2> | |
361 | inline void | |
362 | pair_hash <T1, T2>::mark_empty (value_type &x) | |
363 | { | |
364 | T1::mark_empty (x.first); | |
365 | } | |
366 | ||
367 | template <typename T1, typename T2> | |
368 | inline bool | |
369 | pair_hash <T1, T2>::is_deleted (const value_type &x) | |
370 | { | |
371 | return T1::is_deleted (x.first); | |
372 | } | |
373 | ||
374 | template <typename T1, typename T2> | |
375 | inline bool | |
376 | pair_hash <T1, T2>::is_empty (const value_type &x) | |
377 | { | |
378 | return T1::is_empty (x.first); | |
379 | } | |
380 | ||
fb5c464a | 381 | template <typename T> struct default_hash_traits : T {}; |
b32ca1df RS |
382 | |
383 | template <typename T> | |
384 | struct default_hash_traits <T *> : ggc_ptr_hash <T> {}; | |
385 | ||
f11c3779 | 386 | #endif |