michael@0: /* Copyright (C) 2002 Jean-Marc Valin */
michael@0: /**
michael@0:    @file stack_alloc.h
michael@0:    @brief Temporary memory allocation on stack
michael@0: */
michael@0: /*
michael@0:    Redistribution and use in source and binary forms, with or without
michael@0:    modification, are permitted provided that the following conditions
michael@0:    are met:
michael@0: 
michael@0:    - Redistributions of source code must retain the above copyright
michael@0:    notice, this list of conditions and the following disclaimer.
michael@0: 
michael@0:    - Redistributions in binary form must reproduce the above copyright
michael@0:    notice, this list of conditions and the following disclaimer in the
michael@0:    documentation and/or other materials provided with the distribution.
michael@0: 
michael@0:    - Neither the name of the Xiph.org Foundation nor the names of its
michael@0:    contributors may be used to endorse or promote products derived from
michael@0:    this software without specific prior written permission.
michael@0: 
michael@0:    THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
michael@0:    ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
michael@0:    LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
michael@0:    A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR
michael@0:    CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
michael@0:    EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
michael@0:    PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
michael@0:    PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
michael@0:    LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
michael@0:    NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
michael@0:    SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
michael@0: */
michael@0: 
michael@0: #ifndef STACK_ALLOC_H
michael@0: #define STACK_ALLOC_H
michael@0: 
michael@0: #ifdef WIN32
michael@0: # include <malloc.h>
michael@0: # ifndef alloca
michael@0: #   define alloca(_x) _alloca(_x);
michael@0: # endif
michael@0: #else
michael@0: #ifdef HAVE_ALLOCA_H
michael@0: #  include <alloca.h>
michael@0: # else
michael@0: #  include <stdlib.h>
michael@0: # endif
michael@0: #endif
michael@0: 
michael@0: /**
michael@0:  * @def ALIGN(stack, size)
michael@0:  *
michael@0:  * Aligns the stack to a 'size' boundary
michael@0:  *
michael@0:  * @param stack Stack
michael@0:  * @param size  New size boundary
michael@0:  */
michael@0: 
michael@0: /**
michael@0:  * @def PUSH(stack, size, type)
michael@0:  *
michael@0:  * Allocates 'size' elements of type 'type' on the stack
michael@0:  *
michael@0:  * @param stack Stack
michael@0:  * @param size  Number of elements
michael@0:  * @param type  Type of element
michael@0:  */
michael@0: 
michael@0: /**
michael@0:  * @def VARDECL(var)
michael@0:  *
michael@0:  * Declare variable on stack
michael@0:  *
michael@0:  * @param var Variable to declare
michael@0:  */
michael@0: 
michael@0: /**
michael@0:  * @def ALLOC(var, size, type)
michael@0:  *
michael@0:  * Allocate 'size' elements of 'type' on stack
michael@0:  *
michael@0:  * @param var  Name of variable to allocate
michael@0:  * @param size Number of elements
michael@0:  * @param type Type of element
michael@0:  */
michael@0: 
michael@0: #ifdef ENABLE_VALGRIND
michael@0: 
michael@0: #include <valgrind/memcheck.h>
michael@0: 
michael@0: #define ALIGN(stack, size) ((stack) += ((size) - (long)(stack)) & ((size) - 1))
michael@0: 
michael@0: #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))))
michael@0: 
michael@0: #else
michael@0: 
michael@0: #define ALIGN(stack, size) ((stack) += ((size) - (long)(stack)) & ((size) - 1))
michael@0: 
michael@0: #define PUSH(stack, size, type) (ALIGN((stack),sizeof(type)),(stack)+=((size)*sizeof(type)),(type*)((stack)-((size)*sizeof(type))))
michael@0: 
michael@0: #endif
michael@0: 
michael@0: #if defined(VAR_ARRAYS)
michael@0: #define VARDECL(var)
michael@0: #define ALLOC(var, size, type) type var[size]
michael@0: #elif defined(USE_ALLOCA)
michael@0: #define VARDECL(var) var
michael@0: #define ALLOC(var, size, type) var = alloca(sizeof(type)*(size))
michael@0: #else
michael@0: #define VARDECL(var) var
michael@0: #define ALLOC(var, size, type) var = PUSH(stack, size, type)
michael@0: #endif
michael@0: 
michael@0: 
michael@0: #endif