godot/thirdparty/libpng/pngmem.c

/* pngmem.c - stub functions for memory allocation
 *
 * Copyright (c) 2018 Cosmin Truta
 * Copyright (c) 1998-2002,2004,2006-2014,2016 Glenn Randers-Pehrson
 * Copyright (c) 1996-1997 Andreas Dilger
 * Copyright (c) 1995-1996 Guy Eric Schalnat, Group 42, Inc.
 *
 * This code is released under the libpng license.
 * For conditions of distribution and use, see the disclaimer
 * and license in png.h
 *
 * This file provides a location for all memory allocation.  Users who
 * need special memory handling are expected to supply replacement
 * functions for png_malloc() and png_free(), and to use
 * png_create_read_struct_2() and png_create_write_struct_2() to
 * identify the replacement functions.
 */

#include "pngpriv.h"

#if defined(PNG_READ_SUPPORTED) || defined(PNG_WRITE_SUPPORTED)
/* Free a png_struct */
void /* PRIVATE */
png_destroy_png_struct(png_structrp png_ptr)
{ … }

/* Allocate memory.  For reasonable files, size should never exceed
 * 64K.  However, zlib may allocate more than 64K if you don't tell
 * it not to.  See zconf.h and png.h for more information.  zlib does
 * need to allocate exactly 64K, so whatever you call here must
 * have the ability to do that.
 */
PNG_FUNCTION(png_voidp,PNGAPI
png_calloc,(png_const_structrp png_ptr, png_alloc_size_t size),PNG_ALLOCATED)
{ … }

/* png_malloc_base, an internal function added at libpng 1.6.0, does the work of
 * allocating memory, taking into account limits and PNG_USER_MEM_SUPPORTED.
 * Checking and error handling must happen outside this routine; it returns NULL
 * if the allocation cannot be done (for any reason.)
 */
PNG_FUNCTION(…)
{ …

#if defined(PNG_TEXT_SUPPORTED) || defined(PNG_sPLT_SUPPORTED) ||\
   defined(PNG_STORE_UNKNOWN_CHUNKS_SUPPORTED)
/* This is really here only to work round a spurious warning in GCC 4.6 and 4.7
 * that arises because of the checks in png_realloc_array that are repeated in
 * png_malloc_array.
 */
static png_voidp
png_malloc_array_checked(png_const_structrp png_ptr, int nelements,
    size_t element_size)
{ … }

PNG_FUNCTION(…)
{ …

PNG_FUNCTION(png_voidp /* PRIVATE */,
png_realloc_array,(png_const_structrp png_ptr, png_const_voidp old_array,
    int old_elements, int add_elements, size_t element_size),PNG_ALLOCATED)
{ … }
#endif /* TEXT || sPLT || STORE_UNKNOWN_CHUNKS */

/* Various functions that have different error handling are derived from this.
 * png_malloc always exists, but if PNG_USER_MEM_SUPPORTED is defined a separate
 * function png_malloc_default is also provided.
 */
PNG_FUNCTION(png_voidp,PNGAPI
png_malloc,(png_const_structrp png_ptr, png_alloc_size_t size),PNG_ALLOCATED)
{ … }

#ifdef PNG_USER_MEM_SUPPORTED
PNG_FUNCTION(png_voidp,PNGAPI
png_malloc_default,(png_const_structrp png_ptr, png_alloc_size_t size),
    PNG_ALLOCATED PNG_DEPRECATED)
{ … }
#endif /* USER_MEM */

/* This function was added at libpng version 1.2.3.  The png_malloc_warn()
 * function will issue a png_warning and return NULL instead of issuing a
 * png_error, if it fails to allocate the requested memory.
 */
PNG_FUNCTION(png_voidp,PNGAPI
png_malloc_warn,(png_const_structrp png_ptr, png_alloc_size_t size),
    PNG_ALLOCATED)
{ … }

/* Free a pointer allocated by png_malloc().  If ptr is NULL, return
 * without taking any action.
 */
void PNGAPI
png_free(png_const_structrp png_ptr, png_voidp ptr)
{ … }

PNG_FUNCTION(…)
{ …

#ifdef PNG_USER_MEM_SUPPORTED
/* This function is called when the application wants to use another method
 * of allocating and freeing memory.
 */
void PNGAPI
png_set_mem_fn(png_structrp png_ptr, png_voidp mem_ptr, png_malloc_ptr
  malloc_fn, png_free_ptr free_fn)
{ … }

/* This function returns a pointer to the mem_ptr associated with the user
 * functions.  The application should free any memory associated with this
 * pointer before png_write_destroy and png_read_destroy are called.
 */
png_voidp PNGAPI
png_get_mem_ptr(png_const_structrp png_ptr)
{ … }
#endif /* USER_MEM */
#endif /* READ || WRITE */