/* pngconf.h - machine configurable file for libpng
* libpng version 1.6.34, September 29, 2017
* Copyright (c) 1998-2002,2004,2006-2016 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
* 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,
#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.
/* 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: */
#ifdef PNG_SETJMP_SUPPORTED
/* Required for the definition of jmp_buf and the declaration of longjmp: */
#ifdef PNG_CONVERT_tIME_SUPPORTED
/* Required for struct tm: */
#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 except for data declarations which
* apparently still cause problems in 2011 on some compilers.
#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
#if !defined(PNG_NO_USE_READ_MACROS) && !defined(PNG_USE_READ_MACROS)
# if PNG_DEFAULT_READ_MACROS
# define PNG_USE_READ_MACROS
/* 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. It is not required for modern C compilers.
# define PNGARG(arglist) arglist
/* 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
* 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 sytems) 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.
* 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
* 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
* 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
* PNG_DLL_IMPORT Set to the magic to force the libpng symbols to come
* from a DLL - used to define PNG_IMPEXP when
/* 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(_Windows) || defined(_WINDOWS) || defined(WIN32) ||\
defined(_WIN32) || defined(__WIN32__) || 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 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
# if defined(__GNUC__) || (defined(_MSC_VER) && (_MSC_VER >= 800))
/* 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
/* An older compiler, or one not detected (erroneously) above,
* if necessary override on the command line to get the correct
* variants for the compiler.
# if PNG_API_RULE == 1 && !defined(PNGAPI)
# 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"
# if (defined(_MSC_VER) && _MSC_VER < 800) ||\
(defined(__BORLANDC__) && __BORLANDC__ < 0x500)
* compilers used '__export' and required this to be after
# define PNG_EXPORT_TYPE(type) type PNG_IMPEXP
# define PNG_DLL_EXPORT __export
# else /* newer compiler */
# define PNG_DLL_EXPORT __declspec(dllexport)
# define PNG_DLL_IMPORT __declspec(dllimport)
# if (defined(__IBMC__) || defined(__IBMCPP__)) && defined(__OS2__)
# 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 . */
# define PNGCBAPI PNGCAPI
/* 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.
# if defined(PNG_USE_DLL) && defined(PNG_DLL_IMPORT)
/* This forces use of a DLL, disallowing static linking */
# define PNG_IMPEXP PNG_DLL_IMPORT
/* 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.)
# define PNG_FUNCTION(type, name, args, attributes) attributes type name args
# define PNG_EXPORT_TYPE(type) PNG_IMPEXP type
/* 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
# define PNG_EXPORTA(ordinal, type, name, args, attributes) \
PNG_FUNCTION(PNG_EXPORT_TYPE(type), (PNGAPI name), PNGARG(args), \
PNG_LINKAGE_API attributes)
/* 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. */
# define PNG_REMOVED(ordinal, type, name, args, attributes)
# define PNG_CALLBACK(type, name, args) type (PNGCBAPI name) PNGARG(args)
/* 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
#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
# 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__))
# if !defined(PNG_NORETURN) && __has_attribute(__noreturn__)
# define PNG_NORETURN __attribute__((__noreturn__))
# if !defined(PNG_ALLOCATED) && __has_attribute(__malloc__)
# define PNG_ALLOCATED __attribute__((__malloc__))
# if !defined(PNG_DEPRECATED) && __has_attribute(__deprecated__)
# define PNG_DEPRECATED __attribute__((__deprecated__))
# if !defined(PNG_PRIVATE)
# if __has_extension(attribute_unavailable_with_message)
# define PNG_PRIVATE __attribute__((__unavailable__(\
"This function is not exported by libpng.")))
# define PNG_RESTRICT __restrict
# define PNG_USE_RESULT __attribute__((__warn_unused_result__))
# define PNG_NORETURN __attribute__((__noreturn__))
# define PNG_ALLOCATED __attribute__((__malloc__))
# define PNG_DEPRECATED __attribute__((__deprecated__))
# if 0 /* Doesn't work so we use deprecated instead*/
__attribute__((warning("This function is not exported by libpng.")))
__attribute__((__deprecated__))
# if ((__GNUC__ > 3) || !defined(__GNUC_MINOR__) || (__GNUC_MINOR__ >= 1))
# define PNG_RESTRICT __restrict
# endif /* __GNUC__.__GNUC_MINOR__ > 3.0 */
# endif /* __GNUC__ >= 3 */
# elif defined(_MSC_VER) && (_MSC_VER >= 1300)
# define PNG_USE_RESULT /* not supported */
# define PNG_NORETURN __declspec(noreturn)
# define PNG_ALLOCATED __declspec(restrict)
# define PNG_DEPRECATED __declspec(deprecated)
# define PNG_PRIVATE __declspec(deprecated)
# define PNG_RESTRICT __restrict
# elif defined(__WATCOMC__)
# define PNG_RESTRICT __restrict
#endif /* PNG_PEDANTIC_WARNINGS */
# define PNG_DEPRECATED /* Use of this function is deprecated */
# define PNG_USE_RESULT /* The result of this function must be checked */
# define PNG_NORETURN /* This function does not return */
# define PNG_ALLOCATED /* The result of the function is new memory */
# define PNG_PRIVATE /* This is a private libpng function */
# define PNG_RESTRICT /* The C99 "restrict" feature */
#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)
#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)
#ifndef PNG_BUILDING_SYMBOL_TABLE
/* Some typedefs to get us started. These should be safe on most of the common
* 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
#if CHAR_BIT == 8 && UCHAR_MAX == 255
typedef unsigned char png_byte;
# error "libpng requires 8-bit bytes"
#if INT_MIN == -32768 && INT_MAX == 32767
#elif SHRT_MIN == -32768 && SHRT_MAX == 32767
typedef short png_int_16;
# error "libpng requires a signed 16-bit type"
typedef unsigned int png_uint_16;
typedef unsigned short png_uint_16;
# error "libpng requires an unsigned 16-bit type"