text: /* Copyright (C) 2002-2003 Jean-Marc Valin
     Copyright (C) 2007-2009 Xiph.Org Foundation */
  /**
     @file stack_alloc.h
     @brief Temporary memory allocation on stack
  */
  /*
     Redistribution and use in source and binary forms, with or without
     modification, are permitted provided that the following conditions
     are met:
  
     - Redistributions of source code must retain the above copyright
     notice, this list of conditions and the following disclaimer.
  
     - Redistributions in binary form must reproduce the above copyright
     notice, this list of conditions and the following disclaimer in the
     documentation and/or other materials provided with the distribution.
  
     THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
     ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
     LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
     A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER
     OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
     EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
     PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
     PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
     LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
     NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
     SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */
  
  #ifndef STACK_ALLOC_H
  #define STACK_ALLOC_H
  
  #include "opus_defines.h"
  #include "opus_types.h"
  
  #if (!defined(VAR_ARRAYS) && !defined(USE_ALLOCA) &&                           \
       !defined(NONTHREADSAFE_PSEUDOSTACK))
  #error                                                                         \
      "Opus requires one of VAR_ARRAYS, USE_ALLOCA, or NONTHREADSAFE_PSEUDOSTACK be defined to select the temporary allocation mode."
  #endif
  
  #ifdef USE_ALLOCA
  #ifdef WIN32
  #include <malloc.h>
  #else
  #ifdef HAVE_ALLOCA_H
  #include <alloca.h>
  #else
  #include <stdlib.h>
  #endif
  #endif
  #endif
  
  /**
   * @def ALIGN(stack, size)
   *
   * Aligns the stack to a 'size' boundary
   *
   * @param stack Stack
   * @param size  New size boundary
   */
  
  /**
   * @def PUSH(stack, size, type)
   *
   * Allocates 'size' elements of type 'type' on the stack
   *
   * @param stack Stack
   * @param size  Number of elements
   * @param type  Type of element
   */
  
  /**
   * @def VARDECL(var)
   *
   * Declare variable on stack
   *
   * @param var Variable to declare
   */
  
  /**
   * @def ALLOC(var, size, type)
   *
   * Allocate 'size' elements of 'type' on stack
   *
   * @param var  Name of variable to allocate
   * @param size Number of elements
   * @param type Type of element
   */
  
  #if defined(VAR_ARRAYS)
  
  #define VARDECL(type, var)
  #define ALLOC(var, size, type) type var[size]
  #define SAVE_STACK
  #define RESTORE_STACK
  #define ALLOC_STACK
  /* C99 does not allow VLAs of size zero */
  #define ALLOC_NONE 1
  
  #elif defined(USE_ALLOCA)
  
  #define VARDECL(type, var) type *var
  
  #ifdef WIN32
  #define ALLOC(var, size, type) var = ((type *)_alloca(sizeof(type) * (size)))
  #else
  #define ALLOC(var, size, type) var = ((type *)alloca(sizeof(type) * (size)))
  #endif
  
  #define SAVE_STACK
  #define RESTORE_STACK
  #define ALLOC_STACK
  #define ALLOC_NONE 0
  
  #else
  
  #ifdef CELT_C
  char *global_stack = 0;
  #else
  extern char *global_stack;
  #endif /* CELT_C */
  
  #ifdef ENABLE_VALGRIND
  
  #include <valgrind/memcheck.h>
  
  #ifdef CELT_C
  char *global_stack_top = 0;
  #else
  extern char *global_stack_top;
  #endif /* CELT_C */
  
  #define ALIGN(stack, size) ((stack) += ((size) - (long)(stack)) & ((size)-1))
  #define PUSH(stack, size, type)                                                \
    (VALGRIND_MAKE_MEM_NOACCESS(stack, global_stack_top - stack),                \
     ALIGN((stack), sizeof(type) / sizeof(char)),                                \
     VALGRIND_MAKE_MEM_UNDEFINED(stack, ((size) * sizeof(type) / sizeof(char))), \
     (stack) += (2 * (size) * sizeof(type) / sizeof(char)),                      \
     (type *)((stack) - (2 * (size) * sizeof(type) / sizeof(char))))
  #define RESTORE_STACK                                                          \
    ((global_stack = _saved_stack),                                              \
     VALGRIND_MAKE_MEM_NOACCESS(global_stack, global_stack_top - global_stack))
  #define ALLOC_STACK                                                            \
    char *_saved_stack;                                                          \
    ((global_stack =                                                             \
          (global_stack == 0)                                                    \
              ? ((global_stack_top = opus_alloc_scratch(GLOBAL_STACK_SIZE * 2) + \
                                     (GLOBAL_STACK_SIZE * 2)) -                  \
                 (GLOBAL_STACK_SIZE * 2))                                        \
              : global_stack),                                                   \
     VALGRIND_MAKE_MEM_NOACCESS(global_stack, global_stack_top - global_stack)); \
    _saved_stack = global_stack;
  
  #else
  
  #define ALIGN(stack, size) ((stack) += ((size) - (long)(stack)) & ((size)-1))
  #define PUSH(stack, size, type)                                                \
    (ALIGN((stack), sizeof(type) / sizeof(char)),                                \
     (stack) += (size) * (sizeof(type) / sizeof(char)),                          \
     (type *)((stack) - (size) * (sizeof(type) / sizeof(char))))
  #define RESTORE_STACK (global_stack = _saved_stack)
  #define ALLOC_STACK                                                            \
    char *_saved_stack;                                                          \
    (global_stack = (global_stack == 0) ? opus_alloc_scratch(GLOBAL_STACK_SIZE)  \
                                        : global_stack);                         \
    _saved_stack = global_stack;
  
  #endif /* ENABLE_VALGRIND */
  
  #include "os_support.h"
  #define VARDECL(type, var) type *var
  #define ALLOC(var, size, type) var = PUSH(global_stack, size, type)
  #define SAVE_STACK char *_saved_stack = global_stack;
  #define ALLOC_NONE 0
  
  #endif /* VAR_ARRAYS */
  
  #ifdef ENABLE_VALGRIND
  
  #include <valgrind/memcheck.h>
  #define OPUS_CHECK_ARRAY(ptr, len)                                             \
    VALGRIND_CHECK_MEM_IS_DEFINED(ptr, len * sizeof(*ptr))
  #define OPUS_CHECK_VALUE(value) VALGRIND_CHECK_VALUE_IS_DEFINED(value)
  #define OPUS_CHECK_ARRAY_COND(ptr, len)                                        \
    VALGRIND_CHECK_MEM_IS_DEFINED(ptr, len * sizeof(*ptr))
  #define OPUS_CHECK_VALUE_COND(value) VALGRIND_CHECK_VALUE_IS_DEFINED(value)
  #define OPUS_PRINT_INT(value)                                                  \
    do {                                                                         \
      fprintf(stderr, #value " = %d at %s:%d\n", value, __FILE__, __LINE__);     \
    } while (0)
  #define OPUS_FPRINTF fprintf
  
  #else
  
  static OPUS_INLINE int _opus_false(void) { return 0; }
  #define OPUS_CHECK_ARRAY(ptr, len) _opus_false()
  #define OPUS_CHECK_VALUE(value) _opus_false()
  #define OPUS_PRINT_INT(value)                                                  \
    do {                                                                         \
    } while (0)
  #define OPUS_FPRINTF (void)
  
  #endif
  
  #endif /* STACK_ALLOC_H */
  