1 /*
2    +----------------------------------------------------------------------+
3    | Zend Engine                                                          |
4    +----------------------------------------------------------------------+
5    | Copyright (c) 1998-2018 The PHP Group                                |
6    +----------------------------------------------------------------------+
7    | This source file is subject to version 3.01 of the PHP license,      |
8    | that is bundled with this package in the file LICENSE, and is        |
9    | available through the world-wide-web at the following url:           |
10    | http://www.php.net/license/3_01.txt                                  |
11    | If you did not receive a copy of the PHP license and are unable to   |
12    | obtain it through the world-wide-web, please send a note to          |
13    | license@php.net so we can mail you a copy immediately.               |
14    +----------------------------------------------------------------------+
15    | Authors: Andy Wingo <wingo@igalia.com>                               |
16    +----------------------------------------------------------------------+
17 */
18 
19 /* $Id:$ */
20 
21 #ifndef _ZEND_WORKLIST_H_
22 #define _ZEND_WORKLIST_H_
23 
24 #include "zend_arena.h"
25 #include "zend_bitset.h"
26 
27 typedef struct _zend_worklist_stack {
28 	int *buf;
29 	int len;
30 	int capacity;
31 } zend_worklist_stack;
32 
33 #define ZEND_WORKLIST_STACK_ALLOCA(s, _len, use_heap) do { \
34 		(s)->buf = (int*)do_alloca(sizeof(int) * _len, use_heap); \
35 		(s)->len = 0; \
36 		(s)->capacity = _len; \
37 	} while (0)
38 
39 #define ZEND_WORKLIST_STACK_FREE_ALLOCA(s, use_heap) \
40 	free_alloca((s)->buf, use_heap)
41 
zend_worklist_stack_prepare(zend_arena ** arena,zend_worklist_stack * stack,int len)42 static inline int zend_worklist_stack_prepare(zend_arena **arena, zend_worklist_stack *stack, int len)
43 {
44 	ZEND_ASSERT(len >= 0);
45 
46 	stack->buf = (int*)zend_arena_calloc(arena, sizeof(*stack->buf), len);
47 	if (!stack->buf) {
48 		return FAILURE;
49 	}
50 	stack->len = 0;
51 	stack->capacity = len;
52 
53 	return SUCCESS;
54 }
55 
zend_worklist_stack_push(zend_worklist_stack * stack,int i)56 static inline void zend_worklist_stack_push(zend_worklist_stack *stack, int i)
57 {
58 	ZEND_ASSERT(stack->len < stack->capacity);
59 	stack->buf[stack->len++] = i;
60 }
61 
zend_worklist_stack_peek(zend_worklist_stack * stack)62 static inline int zend_worklist_stack_peek(zend_worklist_stack *stack)
63 {
64 	ZEND_ASSERT(stack->len);
65 	return stack->buf[stack->len - 1];
66 }
67 
zend_worklist_stack_pop(zend_worklist_stack * stack)68 static inline int zend_worklist_stack_pop(zend_worklist_stack *stack)
69 {
70 	ZEND_ASSERT(stack->len);
71 	return stack->buf[--stack->len];
72 }
73 
74 typedef struct _zend_worklist {
75 	zend_bitset visited;
76 	zend_worklist_stack stack;
77 } zend_worklist;
78 
79 #define ZEND_WORKLIST_ALLOCA(w, _len, use_heap) do { \
80 		(w)->stack.buf = (int*)do_alloca(ZEND_MM_ALIGNED_SIZE(sizeof(int) * _len) + sizeof(zend_ulong) * zend_bitset_len(_len), use_heap); \
81 		(w)->stack.len = 0; \
82 		(w)->stack.capacity = _len; \
83 		(w)->visited = (zend_bitset)((char*)(w)->stack.buf + ZEND_MM_ALIGNED_SIZE(sizeof(int) * _len)); \
84 		memset((w)->visited, 0, sizeof(zend_ulong) * zend_bitset_len(_len)); \
85 	} while (0)
86 
87 #define ZEND_WORKLIST_FREE_ALLOCA(w, use_heap) \
88 	free_alloca((w)->stack.buf, use_heap)
89 
zend_worklist_prepare(zend_arena ** arena,zend_worklist * worklist,int len)90 static inline int zend_worklist_prepare(zend_arena **arena, zend_worklist *worklist, int len)
91 {
92 	ZEND_ASSERT(len >= 0);
93 	worklist->visited = (zend_bitset)zend_arena_calloc(arena, sizeof(zend_ulong), zend_bitset_len(len));
94 	if (!worklist->visited) {
95 		return FAILURE;
96 	}
97 	return zend_worklist_stack_prepare(arena, &worklist->stack, len);
98 }
99 
zend_worklist_len(zend_worklist * worklist)100 static inline int zend_worklist_len(zend_worklist *worklist)
101 {
102 	return worklist->stack.len;
103 }
104 
zend_worklist_push(zend_worklist * worklist,int i)105 static inline int zend_worklist_push(zend_worklist *worklist, int i)
106 {
107 	ZEND_ASSERT(i >= 0 && i < worklist->stack.capacity);
108 
109 	if (zend_bitset_in(worklist->visited, i)) {
110 		return 0;
111 	}
112 
113 	zend_bitset_incl(worklist->visited, i);
114 	zend_worklist_stack_push(&worklist->stack, i);
115 	return 1;
116 }
117 
zend_worklist_peek(zend_worklist * worklist)118 static inline int zend_worklist_peek(zend_worklist *worklist)
119 {
120 	return zend_worklist_stack_peek(&worklist->stack);
121 }
122 
zend_worklist_pop(zend_worklist * worklist)123 static inline int zend_worklist_pop(zend_worklist *worklist)
124 {
125 	/* Does not clear visited flag */
126 	return zend_worklist_stack_pop(&worklist->stack);
127 }
128 
129 #endif /* _ZEND_WORKLIST_H_ */
130 
131 /*
132  * Local variables:
133  * tab-width: 4
134  * c-basic-offset: 4
135  * indent-tabs-mode: t
136  * End:
137  */
138