• pngconf.h
  • /* pngconf.h - machine-configurable file for libpng
     *
     * libpng version 1.6.47
     *
     * Copyright (c) 2018-2025 Cosmin Truta
     * Copyright (c) 1998-2002,2004,2006-2016,2018 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
     *
     * Any machine specific code is near the front of this file, so if you
     * are configuring libpng for a machine, you may want to read the section
     * starting here down to where it starts to typedef png_color, png_text,
     * and png_info.
     */
    
    #ifndef PNGCONF_H
    #define PNGCONF_H
    
    #ifndef PNG_BUILDING_SYMBOL_TABLE /* else includes may cause problems */
    
    /* From libpng 1.6.0 libpng requires an ANSI X3.159-1989 ("ISOC90") compliant C
     * compiler for correct compilation.  The following header files are required by
     * the standard.  If your compiler doesn't provide these header files, or they
     * do not match the standard, you will need to provide/improve them.
     */
    #include <limits.h>
    #include <stddef.h>
    
    /* Library header files.  These header files are all defined by ISOC90; libpng
     * expects conformant implementations, however, an ISOC90 conformant system need
     * not provide these header files if the functionality cannot be implemented.
     * In this case it will be necessary to disable the relevant parts of libpng in
     * the build of pnglibconf.h.
     *
     * Prior to 1.6.0 string.h was included here; the API changes in 1.6.0 to not
     * include this unnecessary header file.
     */
    
    #ifdef PNG_STDIO_SUPPORTED
       /* Required for the definition of FILE: */
    #  include <stdio.h>
    #endif
    
    #ifdef PNG_SETJMP_SUPPORTED
       /* Required for the definition of jmp_buf and the declaration of longjmp: */
    #  include <setjmp.h>
    #endif
    
    #ifdef PNG_CONVERT_tIME_SUPPORTED
       /* Required for struct tm: */
    #  include <time.h>
    #endif
    
    #endif /* PNG_BUILDING_SYMBOL_TABLE */
    
    /* Prior to 1.6.0, it was possible to turn off 'const' in declarations,
     * using PNG_NO_CONST.  This is no longer supported.
     */
    #define PNG_CONST const /* backward compatibility only */
    
    /* This controls optimization of the reading of 16-bit and 32-bit
     * values from PNG files.  It can be set on a per-app-file basis: it
     * just changes whether a macro is used when the function is called.
     * The library builder sets the default; if read functions are not
     * built into the library the macro implementation is forced on.
     */
    #ifndef PNG_READ_INT_FUNCTIONS_SUPPORTED
    #  define PNG_USE_READ_MACROS
    #endif
    #if !defined(PNG_NO_USE_READ_MACROS) && !defined(PNG_USE_READ_MACROS)
    #  if PNG_DEFAULT_READ_MACROS
    #    define PNG_USE_READ_MACROS
    #  endif
    #endif
    
    /* COMPILER SPECIFIC OPTIONS.
     *
     * These options are provided so that a variety of difficult compilers
     * can be used.  Some are fixed at build time (e.g. PNG_API_RULE
     * below) but still have compiler specific implementations, others
     * may be changed on a per-file basis when compiling against libpng.
     */
    
    /* The PNGARG macro was used in versions of libpng prior to 1.6.0 to protect
     * against legacy (pre ISOC90) compilers that did not understand function
     * prototypes.  [Deprecated.]
     */
    #ifndef PNGARG
    #  define PNGARG(arglist) arglist
    #endif
    
    /* Function calling conventions.
     * =============================
     * Normally it is not necessary to specify to the compiler how to call
     * a function - it just does it - however on x86 systems derived from
     * Microsoft and Borland C compilers ('IBM PC', 'DOS', 'Windows' systems
     * and some others) there are multiple ways to call a function and the
     * default can be changed on the compiler command line.  For this reason
     * libpng specifies the calling convention of every exported function and
     * every function called via a user supplied function pointer.  This is
     * done in this file by defining the following macros:
     *
     * PNGAPI    Calling convention for exported functions.
     * PNGCBAPI  Calling convention for user provided (callback) functions.
     * PNGCAPI   Calling convention used by the ANSI-C library (required
     *           for longjmp callbacks and sometimes used internally to
     *           specify the calling convention for zlib).
     *
     * These macros should never be overridden.  If it is necessary to
     * change calling convention in a private build this can be done
     * by setting PNG_API_RULE (which defaults to 0) to one of the values
     * below to select the correct 'API' variants.
     *
     * PNG_API_RULE=0 Use PNGCAPI - the 'C' calling convention - throughout.
     *                This is correct in every known environment.
     * PNG_API_RULE=1 Use the operating system convention for PNGAPI and
     *                the 'C' calling convention (from PNGCAPI) for
     *                callbacks (PNGCBAPI).  This is no longer required
     *                in any known environment - if it has to be used
     *                please post an explanation of the problem to the
     *                libpng mailing list.
     *
     * These cases only differ if the operating system does not use the C
     * calling convention, at present this just means the above cases
     * (x86 DOS/Windows systems) and, even then, this does not apply to
     * Cygwin running on those systems.
     *
     * Note that the value must be defined in pnglibconf.h so that what
     * the application uses to call the library matches the conventions
     * set when building the library.
     */
    
    /* Symbol export
     * =============
     * When building a shared library it is almost always necessary to tell
     * the compiler which symbols to export.  The png.h macro 'PNG_EXPORT'
     * is used to mark the symbols.  On some systems these symbols can be
     * extracted at link time and need no special processing by the compiler,
     * on other systems the symbols are flagged by the compiler and just
     * the declaration requires a special tag applied (unfortunately) in a
     * compiler dependent way.  Some systems can do either.
     *
     * A small number of older systems also require a symbol from a DLL to
     * be flagged to the program that calls it.  This is a problem because
     * we do not know in the header file included by application code that
     * the symbol will come from a shared library, as opposed to a statically
     * linked one.  For this reason the application must tell us by setting
     * the magic flag PNG_USE_DLL to turn on the special processing before
     * it includes png.h.
     *
     * Four additional macros are used to make this happen:
     *
     * PNG_IMPEXP The magic (if any) to cause a symbol to be exported from
     *            the build or imported if PNG_USE_DLL is set - compiler
     *            and system specific.
     *
     * PNG_EXPORT_TYPE(type) A macro that pre or appends PNG_IMPEXP to
     *                       'type', compiler specific.
     *
     * PNG_DLL_EXPORT Set to the magic to use during a libpng build to
     *                make a symbol exported from the DLL.  Not used in the
     *                public header files; see pngpriv.h for how it is used
     *                in the libpng build.
     *
     * PNG_DLL_IMPORT Set to the magic to force the libpng symbols to come
     *                from a DLL - used to define PNG_IMPEXP when
     *                PNG_USE_DLL is set.
     */
    
    /* System specific discovery.
     * ==========================
     * This code is used at build time to find PNG_IMPEXP, the API settings
     * and PNG_EXPORT_TYPE(), it may also set a macro to indicate the DLL
     * import processing is possible.  On Windows systems it also sets
     * compiler-specific macros to the values required to change the calling
     * conventions of the various functions.
     */
    #if defined(_WIN32) || defined(__WIN32__) || defined(__NT__) || \
        defined(__CYGWIN__)
      /* Windows system (DOS doesn't support DLLs).  Includes builds under Cygwin or
       * MinGW on any architecture currently supported by Windows.  Also includes
       * Watcom builds but these need special treatment because they are not
       * compatible with GCC or Visual C because of different calling conventions.
       */
    #  if PNG_API_RULE == 2
       /* If this line results in an error, either because __watcall is not
        * understood or because of a redefine just below you cannot use *this*
        * build of the library with the compiler you are using.  *This* build was
        * build using Watcom and applications must also be built using Watcom!
        */
    #    define PNGCAPI __watcall
    #  endif
    
    #  if defined(__GNUC__) || (defined(_MSC_VER) && (_MSC_VER >= 800))
    #    define PNGCAPI __cdecl
    #    if PNG_API_RULE == 1
       /* If this line results in an error __stdcall is not understood and
        * PNG_API_RULE should not have been set to '1'.
        */
    #      define PNGAPI __stdcall
    #    endif
    #  else
       /* An older compiler, or one not detected (erroneously) above,
        * if necessary override on the command line to get the correct
        * variants for the compiler.
        */
    #    ifndef PNGCAPI
    #      define PNGCAPI _cdecl
    #    endif
    #    if PNG_API_RULE == 1 && !defined(PNGAPI)
    #      define PNGAPI _stdcall
    #    endif
    #  endif /* compiler/api */
    
      /* NOTE: PNGCBAPI always defaults to PNGCAPI. */
    
    #  if defined(PNGAPI) && !defined(PNG_USER_PRIVATEBUILD)
    #     error "PNG_USER_PRIVATEBUILD must be defined if PNGAPI is changed"
    #  endif
    
    #  if (defined(_MSC_VER) && _MSC_VER < 800) ||\
          (defined(__BORLANDC__) && __BORLANDC__ < 0x500)
       /* older Borland and MSC
        * compilers used '__export' and required this to be after
        * the type.
        */
    #    ifndef PNG_EXPORT_TYPE
    #      define PNG_EXPORT_TYPE(type) type PNG_IMPEXP
    #    endif
    #    define PNG_DLL_EXPORT __export
    #  else /* newer compiler */
    #    define PNG_DLL_EXPORT __declspec(dllexport)
    #    ifndef PNG_DLL_IMPORT
    #      define PNG_DLL_IMPORT __declspec(dllimport)
    #    endif
    #  endif /* compiler */
    
    #else /* !Windows */
    #  if (defined(__IBMC__) || defined(__IBMCPP__)) && defined(__OS2__)
    #    define PNGAPI _System
    #  else /* !Windows/x86 && !OS/2 */
       /* Use the defaults, or define PNG*API on the command line (but
        * this will have to be done for every compile!)
        */
    #  endif /* other system, !OS/2 */
    #endif /* !Windows/x86 */
    
    /* Now do all the defaulting . */
    #ifndef PNGCAPI
    #  define PNGCAPI
    #endif
    #ifndef PNGCBAPI
    #  define PNGCBAPI PNGCAPI
    #endif
    #ifndef PNGAPI
    #  define PNGAPI PNGCAPI
    #endif
    
    /* PNG_IMPEXP may be set on the compilation system command line or (if not set)
     * then in an internal header file when building the library, otherwise (when
     * using the library) it is set here.
     */
    #ifndef PNG_IMPEXP
    #  if defined(PNG_USE_DLL) && defined(PNG_DLL_IMPORT)
       /* This forces use of a DLL, disallowing static linking */
    #    define PNG_IMPEXP PNG_DLL_IMPORT
    #  endif
    
    #  ifndef PNG_IMPEXP
    #    define PNG_IMPEXP
    #  endif
    #endif
    
    /* In 1.5.2 the definition of PNG_FUNCTION has been changed to always treat
     * 'attributes' as a storage class - the attributes go at the start of the
     * function definition, and attributes are always appended regardless of the
     * compiler.  This considerably simplifies these macros but may cause problems
     * if any compilers both need function attributes and fail to handle them as
     * a storage class (this is unlikely.)
     */
    #ifndef PNG_FUNCTION
    #  define PNG_FUNCTION(type, name, args, attributes) attributes type name args
    #endif
    
    #ifndef PNG_EXPORT_TYPE
    #  define PNG_EXPORT_TYPE(type) PNG_IMPEXP type
    #endif
    
       /* The ordinal value is only relevant when preprocessing png.h for symbol
        * table entries, so we discard it here.  See the .dfn files in the
        * scripts directory.
        */
    
    #ifndef PNG_EXPORTA
    #  define PNG_EXPORTA(ordinal, type, name, args, attributes) \
          PNG_FUNCTION(PNG_EXPORT_TYPE(type), (PNGAPI name), args, \
          PNG_LINKAGE_API attributes)
    #endif
    
    /* ANSI-C (C90) does not permit a macro to be invoked with an empty argument,
     * so make something non-empty to satisfy the requirement:
     */
    #define PNG_EMPTY /*empty list*/
    
    #define PNG_EXPORT(ordinal, type, name, args) \
       PNG_EXPORTA(ordinal, type, name, args, PNG_EMPTY)
    
    /* Use PNG_REMOVED to comment out a removed interface. */
    #ifndef PNG_REMOVED
    #  define PNG_REMOVED(ordinal, type, name, args, attributes)
    #endif
    
    #ifndef PNG_CALLBACK
    #  define PNG_CALLBACK(type, name, args) type (PNGCBAPI name) args
    #endif
    
    /* Support for compiler specific function attributes.  These are used
     * so that where compiler support is available incorrect use of API
     * functions in png.h will generate compiler warnings.
     *
     * Added at libpng-1.2.41.
     */
    
    #ifndef PNG_NO_PEDANTIC_WARNINGS
    #  ifndef PNG_PEDANTIC_WARNINGS_SUPPORTED
    #    define PNG_PEDANTIC_WARNINGS_SUPPORTED
    #  endif
    #endif
    
    #ifdef PNG_PEDANTIC_WARNINGS_SUPPORTED
      /* Support for compiler specific function attributes.  These are used
       * so that where compiler support is available, incorrect use of API
       * functions in png.h will generate compiler warnings.  Added at libpng
       * version 1.2.41.  Disabling these removes the warnings but may also produce
       * less efficient code.
       */
    #  if defined(__clang__) && defined(__has_attribute)
       /* Clang defines both __clang__ and __GNUC__. Check __clang__ first. */
    #    if !defined(PNG_USE_RESULT) && __has_attribute(__warn_unused_result__)
    #      define PNG_USE_RESULT __attribute__((__warn_unused_result__))
    #    endif
    #    if !defined(PNG_NORETURN) && __has_attribute(__noreturn__)
    #      define PNG_NORETURN __attribute__((__noreturn__))
    #    endif
    #    if !defined(PNG_ALLOCATED) && __has_attribute(__malloc__)
    #      define PNG_ALLOCATED __attribute__((__malloc__))
    #    endif
    #    if !defined(PNG_DEPRECATED) && __has_attribute(__deprecated__)
    #      define PNG_DEPRECATED __attribute__((__deprecated__))
    #    endif
    #    if !defined(PNG_PRIVATE)
    #      ifdef __has_extension
    #        if __has_extension(attribute_unavailable_with_message)
    #          define PNG_PRIVATE __attribute__((__unavailable__(\
                 "This function is not exported by libpng.")))
    #        endif
    #      endif
    #    endif
    #    ifndef PNG_RESTRICT
    #      define PNG_RESTRICT __restrict
    #    endif
    
    #  elif defined(__GNUC__)
    #    ifndef PNG_USE_RESULT
    #      define PNG_USE_RESULT __attribute__((__warn_unused_result__))
    #    endif
    #    ifndef PNG_NORETURN
    #      define PNG_NORETURN   __attribute__((__noreturn__))
    #    endif
    #    if __GNUC__ >= 3
    #      ifndef PNG_ALLOCATED
    #        define PNG_ALLOCATED  __attribute__((__malloc__))
    #      endif
    #      ifndef PNG_DEPRECATED
    #        define PNG_DEPRECATED __attribute__((__deprecated__))
    #      endif
    #      ifndef PNG_PRIVATE
    #        if 0 /* Doesn't work so we use deprecated instead*/
    #          define PNG_PRIVATE \
                __attribute__((warning("This function is not exported by libpng.")))
    #        else
    #          define PNG_PRIVATE \
                __attribute__((__deprecated__))
    #        endif
    #      endif
    #      if ((__GNUC__ > 3) || !defined(__GNUC_MINOR__) || (__GNUC_MINOR__ >= 1))
    #        ifndef PNG_RESTRICT
    #          define PNG_RESTRICT __restrict
    #        endif
    #      endif /* __GNUC__.__GNUC_MINOR__ > 3.0 */
    #    endif /* __GNUC__ >= 3 */
    
    #  elif defined(_MSC_VER)  && (_MSC_VER >= 1300)
    #    ifndef PNG_USE_RESULT
    #      define PNG_USE_RESULT /* not supported */
    #    endif
    #    ifndef PNG_NORETURN
    #      define PNG_NORETURN   __declspec(noreturn)
    #    endif
    #    ifndef PNG_ALLOCATED
    #      if (_MSC_VER >= 1400)
    #        define PNG_ALLOCATED __declspec(restrict)
    #      endif
    #    endif
    #    ifndef PNG_DEPRECATED
    #      define PNG_DEPRECATED __declspec(deprecated)
    #    endif
    #    ifndef PNG_PRIVATE
    #      define PNG_PRIVATE __declspec(deprecated)
    #    endif
    #    ifndef PNG_RESTRICT
    #      if (_MSC_VER >= 1400)
    #        define PNG_RESTRICT __restrict
    #      endif
    #    endif
    
    #  elif defined(__WATCOMC__)
    #    ifndef PNG_RESTRICT
    #      define PNG_RESTRICT __restrict
    #    endif
    #  endif
    #endif /* PNG_PEDANTIC_WARNINGS */
    
    #ifndef PNG_DEPRECATED
    #  define PNG_DEPRECATED  /* Use of this function is deprecated */
    #endif
    #ifndef PNG_USE_RESULT
    #  define PNG_USE_RESULT  /* The result of this function must be checked */
    #endif
    #ifndef PNG_NORETURN
    #  define PNG_NORETURN    /* This function does not return */
    #endif
    #ifndef PNG_ALLOCATED
    #  define PNG_ALLOCATED   /* The result of the function is new memory */
    #endif
    #ifndef PNG_PRIVATE
    #  define PNG_PRIVATE     /* This is a private libpng function */
    #endif
    #ifndef PNG_RESTRICT
    #  define PNG_RESTRICT    /* The C99 "restrict" feature */
    #endif
    
    #ifndef PNG_FP_EXPORT     /* A floating point API. */
    #  ifdef PNG_FLOATING_POINT_SUPPORTED
    #     define PNG_FP_EXPORT(ordinal, type, name, args)\
             PNG_EXPORT(ordinal, type, name, args);
    #  else                   /* No floating point APIs */
    #     define PNG_FP_EXPORT(ordinal, type, name, args)
    #  endif
    #endif
    #ifndef PNG_FIXED_EXPORT  /* A fixed point API. */
    #  ifdef PNG_FIXED_POINT_SUPPORTED
    #     define PNG_FIXED_EXPORT(ordinal, type, name, args)\
             PNG_EXPORT(ordinal, type, name, args);
    #  else                   /* No fixed point APIs */
    #     define PNG_FIXED_EXPORT(ordinal, type, name, args)
    #  endif
    #endif
    
    #ifndef PNG_BUILDING_SYMBOL_TABLE
    /* Some typedefs to get us started.  These should be safe on most of the common
     * platforms.
     *
     * png_uint_32 and png_int_32 may, currently, be larger than required to hold a
     * 32-bit value however this is not normally advisable.
     *
     * png_uint_16 and png_int_16 should always be two bytes in size - this is
     * verified at library build time.
     *
     * png_byte must always be one byte in size.
     *
     * The checks below use constants from limits.h, as defined by the ISOC90
     * standard.
     */
    #if CHAR_BIT == 8 && UCHAR_MAX == 255
       typedef unsigned char png_byte;
    #else
    #  error "libpng requires 8-bit bytes"
    #endif
    
    #if INT_MIN == -32768 && INT_MAX == 32767
       typedef int png_int_16;
    #elif SHRT_MIN == -32768 && SHRT_MAX == 32767
       typedef short png_int_16;
    #else
    #  error "libpng requires a signed 16-bit type"
    #endif
    
    #if UINT_MAX == 65535
       typedef unsigned int png_uint_16;
    #elif USHRT_MAX == 65535
       typedef unsigned short png_uint_16;
    #else
    #  error "libpng requires an unsigned 16-bit type"
    #endif
    
    #if INT_MIN < -2147483646 && INT_MAX > 2147483646
       typedef int png_int_32;
    #elif LONG_MIN < -2147483646 && LONG_MAX > 2147483646
       typedef long int png_int_32;
    #else
    #  error "libpng requires a signed 32-bit (or more) type"
    #endif
    
    #if UINT_MAX > 4294967294U
       typedef unsigned int png_uint_32;
    #elif ULONG_MAX > 4294967294U
       typedef unsigned long int png_uint_32;
    #else
    #  error "libpng requires an unsigned 32-bit (or more) type"
    #endif
    
    /* Prior to 1.6.0, it was possible to disable the use of size_t and ptrdiff_t.
     * From 1.6.0 onwards, an ISO C90 compiler, as well as a standard-compliant
     * behavior of sizeof and ptrdiff_t are required.
     * The legacy typedefs are provided here for backwards compatibility.
     */
    typedef size_t png_size_t;
    typedef ptrdiff_t png_ptrdiff_t;
    
    /* libpng needs to know the maximum value of 'size_t' and this controls the
     * definition of png_alloc_size_t, below.  This maximum value of size_t limits
     * but does not control the maximum allocations the library makes - there is
     * direct application control of this through png_set_user_limits().
     */
    #ifndef PNG_SMALL_SIZE_T
       /* Compiler specific tests for systems where size_t is known to be less than
        * 32 bits (some of these systems may no longer work because of the lack of
        * 'far' support; see above.)
        */
    #  if (defined(__TURBOC__) && !defined(__FLAT__)) ||\
       (defined(_MSC_VER) && defined(MAXSEG_64K))
    #     define PNG_SMALL_SIZE_T
    #  endif
    #endif
    
    /* png_alloc_size_t is guaranteed to be no smaller than size_t, and no smaller
     * than png_uint_32.  Casts from size_t or png_uint_32 to png_alloc_size_t are
     * not necessary; in fact, it is recommended not to use them at all, so that
     * the compiler can complain when something turns out to be problematic.
     *
     * Casts in the other direction (from png_alloc_size_t to size_t or
     * png_uint_32) should be explicitly applied; however, we do not expect to
     * encounter practical situations that require such conversions.
     *
     * PNG_SMALL_SIZE_T must be defined if the maximum value of size_t is less than
     * 4294967295 - i.e. less than the maximum value of png_uint_32.
     */
    #ifdef PNG_SMALL_SIZE_T
       typedef png_uint_32 png_alloc_size_t;
    #else
       typedef size_t png_alloc_size_t;
    #endif
    
    /* Prior to 1.6.0 libpng offered limited support for Microsoft C compiler
     * implementations of Intel CPU specific support of user-mode segmented address
     * spaces, where 16-bit pointers address more than 65536 bytes of memory using
     * separate 'segment' registers.  The implementation requires two different
     * types of pointer (only one of which includes the segment value.)
     *
     * If required this support is available in version 1.2 of libpng and may be
     * available in versions through 1.5, although the correctness of the code has
     * not been verified recently.
     */
    
    /* Typedef for floating-point numbers that are converted to fixed-point with a
     * multiple of 100,000, e.g., gamma
     */
    typedef png_int_32 png_fixed_point;
    
    /* Add typedefs for pointers */
    typedef void                  * png_voidp;
    typedef const void            * png_const_voidp;
    typedef png_byte              * png_bytep;
    typedef const png_byte        * png_const_bytep;
    typedef png_uint_32           * png_uint_32p;
    typedef const png_uint_32     * png_const_uint_32p;
    typedef png_int_32            * png_int_32p;
    typedef const png_int_32      * png_const_int_32p;
    typedef png_uint_16           * png_uint_16p;
    typedef const png_uint_16     * png_const_uint_16p;
    typedef png_int_16            * png_int_16p;
    typedef const png_int_16      * png_const_int_16p;
    typedef char                  * png_charp;
    typedef const char            * png_const_charp;
    typedef png_fixed_point       * png_fixed_point_p;
    typedef const png_fixed_point * png_const_fixed_point_p;
    typedef size_t                * png_size_tp;
    typedef const size_t          * png_const_size_tp;
    
    #ifdef PNG_STDIO_SUPPORTED
    typedef FILE            * png_FILE_p;
    #endif
    
    #ifdef PNG_FLOATING_POINT_SUPPORTED
    typedef double       * png_doublep;
    typedef const double * png_const_doublep;
    #endif
    
    /* Pointers to pointers; i.e. arrays */
    typedef png_byte        * * png_bytepp;
    typedef png_uint_32     * * png_uint_32pp;
    typedef png_int_32      * * png_int_32pp;
    typedef png_uint_16     * * png_uint_16pp;
    typedef png_int_16      * * png_int_16pp;
    typedef const char      * * png_const_charpp;
    typedef char            * * png_charpp;
    typedef png_fixed_point * * png_fixed_point_pp;
    #ifdef PNG_FLOATING_POINT_SUPPORTED
    typedef double          * * png_doublepp;
    #endif
    
    /* Pointers to pointers to pointers; i.e., pointer to array */
    typedef char            * * * png_charppp;
    
    #endif /* PNG_BUILDING_SYMBOL_TABLE */
    
    #endif /* PNGCONF_H */