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1 #ifndef PTR_LIST_H
2 #define PTR_LIST_H
3 
4 #include <stdlib.h>
5 #include <stdbool.h>
6 
7 /*
8  * Generic pointer list manipulation code.
9  *
10  * (C) Copyright Linus Torvalds 2003-2005
11  */
12 
13 /* Silly type-safety check ;) */
14 #define CHECK_TYPE(head,ptr)		(void)(&(ptr) == &(head)->list[0])
15 #define PTRLIST_TYPE(head)		__typeof__((head)->list[0])
16 #define VRFY_PTR_LIST(head)		(void)(sizeof((head)->list[0]))
17 
18 #define LIST_NODE_NR (13)
19 
20 #define DECLARE_PTR_LIST(listname, type)	\
21 	struct listname {			\
22 		int nr:8;			\
23 		int rm:8;			\
24 		struct listname *prev;		\
25 		struct listname *next;		\
26 		type *list[LIST_NODE_NR];	\
27 	}
28 
29 DECLARE_PTR_LIST(ptr_list, void);
30 
31 
32 void * undo_ptr_list_last(struct ptr_list **head);
33 void * delete_ptr_list_last(struct ptr_list **head);
34 int delete_ptr_list_entry(struct ptr_list **, void *, int);
35 int replace_ptr_list_entry(struct ptr_list **, void *old, void *new, int);
36 bool lookup_ptr_list_entry(const struct ptr_list *head, const void *entry);
37 extern void sort_list(struct ptr_list **, int (*)(const void *, const void *));
38 
39 extern void concat_ptr_list(struct ptr_list *a, struct ptr_list **b);
40 extern void copy_ptr_list(struct ptr_list **h, struct ptr_list *t);
41 extern int ptr_list_size(struct ptr_list *);
42 extern bool ptr_list_empty(const struct ptr_list *head);
43 extern bool ptr_list_multiple(const struct ptr_list *head);
44 extern int linearize_ptr_list(struct ptr_list *, void **, int);
45 extern void *first_ptr_list(struct ptr_list *);
46 extern void *last_ptr_list(struct ptr_list *);
47 extern void *ptr_list_nth_entry(struct ptr_list *, unsigned int idx);
48 extern void pack_ptr_list(struct ptr_list **);
49 
50 /*
51  * Hey, who said that you can't do overloading in C?
52  *
53  * You just have to be creative, and use some gcc
54  * extensions..
55  */
56 extern void **__add_ptr_list(struct ptr_list **, void *);
57 extern void **__add_ptr_list_tag(struct ptr_list **, void *, unsigned long);
58 
59 #define add_ptr_list(list, ptr) ({					\
60 		struct ptr_list** head = (struct ptr_list**)(list);	\
61 		CHECK_TYPE(*(list),ptr);				\
62 		(__typeof__(&(ptr))) __add_ptr_list(head, ptr);		\
63 	})
64 #define add_ptr_list_tag(list, ptr, tag) ({				\
65 		struct ptr_list** head = (struct ptr_list**)(list);	\
66 		CHECK_TYPE(*(list),ptr);				\
67 		(__typeof__(&(ptr))) __add_ptr_list_tag(head, ptr, tag);\
68 	})
69 
70 #define pop_ptr_list(l) ({						\
71 		PTRLIST_TYPE(*(l)) ptr;					\
72 		ptr = delete_ptr_list_last((struct ptr_list**)(l));	\
73 		ptr;							\
74 	})
75 
76 extern void __free_ptr_list(struct ptr_list **);
77 #define free_ptr_list(list)	do {					\
78 		VRFY_PTR_LIST(*(list));					\
79 		__free_ptr_list((struct ptr_list **)(list));		\
80 	} while (0)
81 
82 #define ptr_list_nth(lst, nth) ({					\
83 		struct ptr_list* head = (struct ptr_list*)(lst);	\
84 		(PTRLIST_TYPE(lst)) ptr_list_nth_entry(head, nth);\
85 	})
86 
87 #define ptr_list_to_array(list, array, size) ({				\
88 		struct ptr_list* head = (struct ptr_list*)(list);	\
89 		CHECK_TYPE(list, *array);				\
90 		linearize_ptr_list(head, (void**)array, size);		\
91 	})
92 
93 ////////////////////////////////////////////////////////////////////////
94 // API
95 #define PREPARE_PTR_LIST(head, ptr) \
96 	DO_PREPARE(head, ptr, __head##ptr, __list##ptr, __nr##ptr, PTR_ENTRY_UNTAG)
97 
98 #define NEXT_PTR_LIST(ptr) \
99 	DO_NEXT(ptr, __head##ptr, __list##ptr, __nr##ptr, PTR_ENTRY_UNTAG)
100 
101 #define RESET_PTR_LIST(ptr) \
102 	DO_RESET(ptr, __head##ptr, __list##ptr, __nr##ptr, PTR_ENTRY_UNTAG)
103 
104 #define FINISH_PTR_LIST(ptr) \
105 	DO_FINISH(ptr, __head##ptr, __list##ptr, __nr##ptr)
106 
107 #define RECURSE_PTR_REVERSE(ptr, new)					\
108 	DO_REVERSE(ptr, __head##ptr, __list##ptr, __nr##ptr, __rname##new, \
109 		   new, __head##new, __list##new, __nr##new, PTR_ENTRY_UNTAG)
110 
111 
112 #define FOR_EACH_PTR(head, ptr) \
113 	DO_FOR_EACH(head, ptr, __head##ptr, __list##ptr, __nr##ptr, __name##ptr, PTR_ENTRY_NOTAG)
114 
115 #define FOR_EACH_PTR_TAG(head, ptr) \
116 	DO_FOR_EACH(head, ptr, __head##ptr, __list##ptr, __nr##ptr, __name##ptr,  PTR_ENTRY_UNTAG)
117 
118 #define END_FOR_EACH_PTR(ptr) \
119 	DO_END_FOR_EACH(ptr, __head##ptr, __list##ptr, __nr##ptr, __name##ptr)
120 
121 #define FOR_EACH_PTR_REVERSE(head, ptr) \
122 	DO_FOR_EACH_REVERSE(head, ptr, __head##ptr, __list##ptr, __nr##ptr, __rname##ptr,  PTR_ENTRY_NOTAG)
123 
124 #define FOR_EACH_PTR_REVERSE_TAG(head, ptr) \
125 	DO_FOR_EACH_REVERSE(head, ptr, __head##ptr, __list##ptr, __nr##ptr, __rname##ptr, PTR_ENTRY_UNTAG)
126 
127 #define END_FOR_EACH_PTR_REVERSE(ptr) \
128 	DO_END_FOR_EACH_REVERSE(ptr, __head##ptr, __list##ptr, __nr##ptr, __rname##ptr)
129 
130 #define THIS_ADDRESS(ptr) \
131 	DO_THIS_ADDRESS(ptr, __head##ptr, __list##ptr, __nr##ptr)
132 
133 #define INSERT_CURRENT(new, ptr) \
134 	DO_INSERT_CURRENT(new, __head##ptr, __list##ptr, __nr##ptr)
135 
136 #define DELETE_CURRENT_PTR(ptr) \
137 	DO_DELETE_CURRENT(__head##ptr, __list##ptr, __nr##ptr)
138 
139 #define REPLACE_CURRENT_PTR(ptr, new_ptr)				\
140 	do { *THIS_ADDRESS(ptr) = (new_ptr); } while (0)
141 
142 // This replace the current element by a null-pointer.
143 // It's used when an element of the list must be removed
144 // but the address of the other elements must not be changed.
145 #define MARK_CURRENT_DELETED(ptr) \
146 	DO_MARK_CURRENT_DELETED(ptr, __list##ptr)
147 
148 #define PACK_PTR_LIST(x) \
149 	pack_ptr_list((struct ptr_list **)(x))
150 
151 #define CURRENT_TAG(ptr)	(3 & (unsigned long)*THIS_ADDRESS(ptr))
152 #define TAG_CURRENT(ptr,val)	update_tag(THIS_ADDRESS(ptr),val)
153 
154 // backward compatibility for smatch
155 #define FOR_EACH_PTR_NOTAG(list, ptr)	FOR_EACH_PTR(list, ptr)
156 #define END_FOR_EACH_PTR_NOTAG(ptr)	END_FOR_EACH_PTR(ptr)
157 
158 ////////////////////////////////////////////////////////////////////////
159 // Implementation
160 #define PTR_UNTAG(p)		((void*)(~3UL & (unsigned long)(p)))
161 #define PTR_ENTRY_NOTAG(h,i)	((h)->list[i])
162 #define PTR_ENTRY_UNTAG(h,i)	PTR_UNTAG((h)->list[i])
163 
164 
165 #define PTR_NEXT(ptr, __head, __list, __nr, PTR_ENTRY)			\
166 	do {								\
167 		if (__nr < __list->nr) {				\
168 			ptr = PTR_ENTRY(__list,__nr);			\
169 			__nr++;						\
170 			break;						\
171 		}							\
172 		ptr = NULL;						\
173 		__nr = 0;						\
174 	} while ((__list = __list->next) != __head)			\
175 
176 #define DO_PREPARE(head, ptr, __head, __list, __nr, PTR_ENTRY)		\
177 	do {								\
178 		__typeof__(head) __head = (head);			\
179 		__typeof__(head) __list = __head;			\
180 		int __nr = 0;						\
181 		ptr = NULL;						\
182 		if (__head) {						\
183 			PTR_NEXT(ptr, __head, __list, __nr, PTR_ENTRY);	\
184 		}							\
185 
186 #define DO_NEXT(ptr, __head, __list, __nr, PTR_ENTRY)			\
187 		if (ptr) {						\
188 			PTR_NEXT(ptr, __head, __list, __nr, PTR_ENTRY);	\
189 		}
190 
191 #define DO_RESET(ptr, __head, __list, __nr, PTR_ENTRY)			\
192 	do {								\
193 		__nr = 0;						\
194 		__list = __head;					\
195 		if (__head)						\
196 			PTR_NEXT(ptr, __head, __list, __nr, PTR_ENTRY);	\
197 	} while (0)
198 
199 #define DO_FINISH(ptr, __head, __list, __nr)				\
200 		VRFY_PTR_LIST(__head); /* Sanity-check nesting */	\
201 	} while (0)
202 
203 #define DO_FOR_EACH(head, ptr, __head, __list, __nr, __name, PTR_ENTRY) do {	\
204 	__typeof__(head) __head = (head);				\
205 	__typeof__(head) __list = __head;				\
206 	__typeof__(head) __name = __head;				\
207 	int __nr;							\
208 	if (!__head)							\
209 		break;							\
210 	do {								\
211 		for (__nr = 0; __nr < __list->nr; __nr++) {		\
212 			ptr = PTR_ENTRY(__list,__nr);			\
213 			if (__list->rm && !ptr)				\
214 				continue;				\
215 
216 #define DO_END_FOR_EACH(ptr, __head, __list, __nr, __name)		\
217 		}							\
218 	} while ((__list = __list->next) != __head);			\
219 	(void) __name;						\
220 } while (0)
221 
222 #define DO_FOR_EACH_REVERSE(head, ptr, __head, __list, __nr, __name, PTR_ENTRY) do { \
223 	__typeof__(head) __head = (head);				\
224 	__typeof__(head) __list = __head;				\
225 	__typeof__(head) __name = __head;				\
226 	int __nr;							\
227 	if (!head)							\
228 		break;							\
229 	do {								\
230 		__list = __list->prev;					\
231 		__nr = __list->nr;					\
232 		while (--__nr >= 0) {					\
233 			ptr = PTR_ENTRY(__list,__nr);			\
234 			if (__list->rm && !ptr)				\
235 				continue;				\
236 
237 
238 #define DO_END_FOR_EACH_REVERSE(ptr, __head, __list, __nr, __name)	\
239 		}							\
240 	} while (__list != __head);					\
241 	(void) __name;							\
242 } while (0)
243 
244 #define DO_REVERSE(ptr, __head, __list, __nr, __name, new, __newhead,	\
245 		   __newlist, __newnr, PTR_ENTRY) do {			\
246 	__typeof__(__head) __newhead = __head;				\
247 	__typeof__(__head) __newlist = __list;				\
248 	__typeof__(__head) __name = __list;				\
249 	int __newnr = __nr;						\
250 	new = ptr;							\
251 	goto __inside##new;						\
252 	do {								\
253 		__newlist = __newlist->prev;				\
254 		__newnr = __newlist->nr;				\
255 	__inside##new:							\
256 		while (--__newnr >= 0) {				\
257 			new = PTR_ENTRY(__newlist,__newnr);		\
258 
259 #define DO_THIS_ADDRESS(ptr, __head, __list, __nr)			\
260 	(&__list->list[__nr])
261 
262 
263 extern void split_ptr_list_head(struct ptr_list *);
264 
265 #define DO_INSERT_CURRENT(new, __head, __list, __nr) do {		\
266 	PTRLIST_TYPE(__head) *__this, *__last;				\
267 	if (__list->nr == LIST_NODE_NR) {				\
268 		split_ptr_list_head((struct ptr_list*)__list);		\
269 		if (__nr >= __list->nr) {				\
270 			__nr -= __list->nr;				\
271 			__list = __list->next;				\
272 		}							\
273 	}								\
274 	__this = __list->list + __nr;					\
275 	__last = __list->list + __list->nr - 1;				\
276 	while (__last >= __this) {					\
277 		__last[1] = __last[0];					\
278 		__last--;						\
279 	}								\
280 	*__this = (new);						\
281 	__list->nr++;							\
282 } while (0)
283 
284 #define DO_DELETE_CURRENT(__head, __list, __nr) do {			\
285 	PTRLIST_TYPE(__head) *__this = __list->list + __nr;		\
286 	PTRLIST_TYPE(__head) *__last = __list->list + __list->nr - 1;	\
287 	while (__this < __last) {					\
288 		__this[0] = __this[1];					\
289 		__this++;						\
290 	}								\
291 	*__this = (void *)0xf0f0f0f0;					\
292 	__list->nr--; __nr--;						\
293 } while (0)
294 
295 
296 #define DO_MARK_CURRENT_DELETED(ptr, __list) do {			\
297 		REPLACE_CURRENT_PTR(ptr, NULL);				\
298 		__list->rm++;						\
299 	} while (0)
300 
301 
update_tag(void * p,unsigned long tag)302 static inline void update_tag(void *p, unsigned long tag)
303 {
304 	unsigned long *ptr = p;
305 	*ptr = tag | (~3UL & *ptr);
306 }
307 
tag_ptr(void * ptr,unsigned long tag)308 static inline void *tag_ptr(void *ptr, unsigned long tag)
309 {
310 	return (void *)(tag | (unsigned long)ptr);
311 }
312 
313 #endif /* PTR_LIST_H */
314