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1 /* Copyright (C) 2002 Jean-Marc Valin */
2 /**
3    @file stack_alloc.h
4    @brief Temporary memory allocation on stack
5 */
6 /*
7    Redistribution and use in source and binary forms, with or without
8    modification, are permitted provided that the following conditions
9    are met:
10 
11    - Redistributions of source code must retain the above copyright
12    notice, this list of conditions and the following disclaimer.
13 
14    - Redistributions in binary form must reproduce the above copyright
15    notice, this list of conditions and the following disclaimer in the
16    documentation and/or other materials provided with the distribution.
17 
18    - Neither the name of the Xiph.org Foundation nor the names of its
19    contributors may be used to endorse or promote products derived from
20    this software without specific prior written permission.
21 
22    THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
23    ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
24    LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
25    A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR
26    CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
27    EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
28    PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
29    PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
30    LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
31    NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
32    SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
33 */
34 
35 #ifndef STACK_ALLOC_H
36 #define STACK_ALLOC_H
37 
38 #ifdef USE_ALLOCA
39 # ifdef WIN32
40 #  include <malloc.h>
41 # else
42 #  ifdef HAVE_ALLOCA_H
43 #   include <alloca.h>
44 #  else
45 #   include <stdlib.h>
46 #  endif
47 # endif
48 #endif
49 
50 /**
51  * @def ALIGN(stack, size)
52  *
53  * Aligns the stack to a 'size' boundary
54  *
55  * @param stack Stack
56  * @param size  New size boundary
57  */
58 
59 /**
60  * @def PUSH(stack, size, type)
61  *
62  * Allocates 'size' elements of type 'type' on the stack
63  *
64  * @param stack Stack
65  * @param size  Number of elements
66  * @param type  Type of element
67  */
68 
69 /**
70  * @def VARDECL(var)
71  *
72  * Declare variable on stack
73  *
74  * @param var Variable to declare
75  */
76 
77 /**
78  * @def ALLOC(var, size, type)
79  *
80  * Allocate 'size' elements of 'type' on stack
81  *
82  * @param var  Name of variable to allocate
83  * @param size Number of elements
84  * @param type Type of element
85  */
86 
87 #ifdef ENABLE_VALGRIND
88 
89 #include <valgrind/memcheck.h>
90 
91 #define ALIGN(stack, size) ((stack) += ((size) - (long)(stack)) & ((size) - 1))
92 
93 #define PUSH(stack, size, type) (VALGRIND_MAKE_NOACCESS(stack, 1000),ALIGN((stack),sizeof(type)),VALGRIND_MAKE_WRITABLE(stack, ((size)*sizeof(type))),(stack)+=((size)*sizeof(type)),(type*)((stack)-((size)*sizeof(type))))
94 
95 #else
96 
97 #define ALIGN(stack, size) ((stack) += ((size) - (long)(stack)) & ((size) - 1))
98 
99 #define PUSH(stack, size, type) (ALIGN((stack),sizeof(type)),(stack)+=((size)*sizeof(type)),(type*)((stack)-((size)*sizeof(type))))
100 
101 #endif
102 
103 #if defined(VAR_ARRAYS)
104 #define VARDECL(var)
105 #define ALLOC(var, size, type) type var[size]
106 #elif defined(USE_ALLOCA)
107 #define VARDECL(var) var
108 #define ALLOC(var, size, type) var = alloca(sizeof(type)*(size))
109 #else
110 #define VARDECL(var) var
111 #define ALLOC(var, size, type) var = PUSH(stack, size, type)
112 #endif
113 
114 
115 #endif
116