The Tor Browser: comparison media/libpng/pngmem.c

--1:000000000000
+:cea69cae3b51
+/* pngmem.c - stub functions for memory allocation
+*
+* Last changed in libpng 1.6.8 [December 19, 2013]
+* Copyright (c) 1998-2013 Glenn Randers-Pehrson
+* (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
+* (Version 0.88 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)
+{
+if (png_ptr != NULL)
+{
+/* png_free might call png_error and may certainly call
+* png_get_mem_ptr, so fake a temporary png_struct to support this.
+*/
+png_struct dummy_struct = *png_ptr;
+memset(png_ptr, 0, (sizeof *png_ptr));
+png_free(&dummy_struct, png_ptr);
+#     ifdef PNG_SETJMP_SUPPORTED
+/* We may have a jmp_buf left to deallocate. */
+png_free_jmpbuf(&dummy_struct);
+#     endif
+}
+}
+/* Allocate memory.  For reasonable files, size should never exceed
+* 64K.  However, zlib may allocate more then 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_voidp ret;
+ret = png_malloc(png_ptr, size);
+if (ret != NULL)
+memset(ret, 0, size);
+return ret;
+}
+/* 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(png_voidp /* PRIVATE */,
+png_malloc_base,(png_const_structrp png_ptr, png_alloc_size_t size),
+PNG_ALLOCATED)
+{
+/* Moved to png_malloc_base from png_malloc_default in 1.6.0; the DOS
+* allocators have also been removed in 1.6.0, so any 16-bit system now has
+* to implement a user memory handler.  This checks to be sure it isn't
+* called with big numbers.
+*/
+#ifndef PNG_USER_MEM_SUPPORTED
+PNG_UNUSED(png_ptr)
+#endif
+if (size > 0 && size <= PNG_SIZE_MAX
+#     ifdef PNG_MAX_MALLOC_64K
+&& size <= 65536U
+#     endif
+)
+{
+#ifdef PNG_USER_MEM_SUPPORTED
+if (png_ptr != NULL && png_ptr->malloc_fn != NULL)
+return png_ptr->malloc_fn(png_constcast(png_structrp,png_ptr), size);
+else
+#endif
+return malloc((size_t)size); /* checked for truncation above */
+}
+else
+return NULL;
+}
+#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_alloc_size_t req = nelements; /* known to be > 0 */
+if (req <= PNG_SIZE_MAX/element_size)
+return png_malloc_base(png_ptr, req * element_size);
+/* The failure case when the request is too large */
+return NULL;
+}
+PNG_FUNCTION(png_voidp /* PRIVATE */,
+png_malloc_array,(png_const_structrp png_ptr, int nelements,
+size_t element_size),PNG_ALLOCATED)
+{
+if (nelements <= 0 || element_size == 0)
+png_error(png_ptr, "internal error: array alloc");
+return png_malloc_array_checked(png_ptr, nelements, element_size);
+}
+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)
+{
+/* These are internal errors: */
+if (add_elements <= 0 || element_size == 0 || old_elements < 0 ||
+(old_array == NULL && old_elements > 0))
+png_error(png_ptr, "internal error: array realloc");
+/* Check for overflow on the elements count (so the caller does not have to
+* check.)
+*/
+if (add_elements <= INT_MAX - old_elements)
+{
+png_voidp new_array = png_malloc_array_checked(png_ptr,
+old_elements+add_elements, element_size);
+if (new_array != NULL)
+{
+/* Because png_malloc_array worked the size calculations below cannot
+* overflow.
+*/
+if (old_elements > 0)
+memcpy(new_array, old_array, element_size*(unsigned)old_elements);
+memset((char*)new_array + element_size*(unsigned)old_elements, 0,
+element_size*(unsigned)add_elements);
+return new_array;
+}
+}
+return NULL; /* error */
+}
+#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)
+{
+png_voidp ret;
+if (png_ptr == NULL)
+return NULL;
+ret = png_malloc_base(png_ptr, size);
+if (ret == NULL)
+png_error(png_ptr, "Out of memory"); /* 'm' means png_malloc */
+return ret;
+}
+#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)
+{
+png_voidp ret;
+if (png_ptr == NULL)
+return NULL;
+/* Passing 'NULL' here bypasses the application provided memory handler. */
+ret = png_malloc_base(NULL/*use malloc*/, size);
+if (ret == NULL)
+png_error(png_ptr, "Out of Memory"); /* 'M' means png_malloc_default */
+return ret;
+}
+#endif /* PNG_USER_MEM_SUPPORTED */
+/* 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)
+{
+if (png_ptr != NULL)
+{
+png_voidp ret = png_malloc_base(png_ptr, size);
+if (ret != NULL)
+return ret;
+png_warning(png_ptr, "Out of memory");
+}
+return NULL;
+}
+/* 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)
+{
+if (png_ptr == NULL || ptr == NULL)
+return;
+#ifdef PNG_USER_MEM_SUPPORTED
+if (png_ptr->free_fn != NULL)
+png_ptr->free_fn(png_constcast(png_structrp,png_ptr), ptr);
+else
+png_free_default(png_ptr, ptr);
+}
+PNG_FUNCTION(void,PNGAPI
+png_free_default,(png_const_structrp png_ptr, png_voidp ptr),PNG_DEPRECATED)
+{
+if (png_ptr == NULL || ptr == NULL)
+return;
+#endif /* PNG_USER_MEM_SUPPORTED */
+free(ptr);
+}
+#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)
+{
+if (png_ptr != NULL)
+{
+png_ptr->mem_ptr = mem_ptr;
+png_ptr->malloc_fn = malloc_fn;
+png_ptr->free_fn = 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)
+{
+if (png_ptr == NULL)
+return NULL;
+return png_ptr->mem_ptr;
+}
+#endif /* PNG_USER_MEM_SUPPORTED */
+#endif /* PNG_READ_SUPPORTED || PNG_WRITE_SUPPORTED */

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comparison: media/libpng/pngmem.c

media/libpng/pngmem.c