Cog/Frameworks/OpenMPT.old/OpenMPT/common/BuildSettings.h
Christopher Snowhill 52ddc26bb9 OpenMPT Legacy: Remove modifications from library
There were some leftover modifications to the 0.5.x tree I was using,
which were supposed to be speed optimizations, but they're probably
pointless anyway. The NEON optimizations were especially pointless,
since this plugin version isn't used on any macOS version that runs on
Apple Silicon.

Signed-off-by: Christopher Snowhill <kode54@gmail.com>
2022-02-08 00:15:49 -08:00

730 lines
18 KiB
C++

/*
* BuildSettings.h
* ---------------
* Purpose: Global, user settable compile time flags (and some global system header configuration)
* Notes : (currently none)
* Authors: OpenMPT Devs
* The OpenMPT source code is released under the BSD license. Read LICENSE for more details.
*/
#pragma once
#include "CompilerDetect.h"
// set windows version early so that we can deduce dependencies from SDK version
#if MPT_OS_WINDOWS
#ifndef _WIN32_WINNT
#define _WIN32_WINNT 0x0601 // _WIN32_WINNT_WIN7
#endif
#ifndef WINVER
#define WINVER _WIN32_WINNT
#endif
#endif // MPT_OS_WINDOWS
#if defined(MODPLUG_TRACKER) && defined(LIBOPENMPT_BUILD)
#error "either MODPLUG_TRACKER or LIBOPENMPT_BUILD has to be defined"
#elif defined(MODPLUG_TRACKER)
// nothing
#elif defined(LIBOPENMPT_BUILD)
// nothing
#else
#error "either MODPLUG_TRACKER or LIBOPENMPT_BUILD has to be defined"
#endif // MODPLUG_TRACKER || LIBOPENMPT_BUILD
// wrapper for autoconf macros
#if defined(HAVE_CONFIG_H)
#include "config.h"
// Fixup dependencies which are currently not used in libopenmpt itself
#ifdef MPT_WITH_FLAC
#undef MPT_WITH_FLAC
#endif
#endif // HAVE_CONFIG_H
// Dependencies from the MSVC build system
#if defined(MPT_BUILD_MSVC)
// This section defines which dependencies are available when building with
// MSVC. Other build systems provide MPT_WITH_* macros via command-line or other
// means.
// OpenMPT and libopenmpt should compile and run successfully (albeit with
// reduced functionality) with any or all dependencies missing/disabled.
// The defaults match the bundled third-party libraries with the addition of
// ASIO and VST SDKs.
#if defined(MODPLUG_TRACKER)
#if MPT_OS_WINDOWS
#if !defined(MPT_BUILD_WINESUPPORT)
#define MPT_WITH_MFC
#endif // !MPT_BUILD_WINESUPPORT
#endif // MPT_OS_WINDOWS
// OpenMPT-only dependencies
#if !MPT_MSVC_BEFORE(2019,0)
// disabled for VS2017 because of multiple initialization of inline variables
// https://developercommunity.visualstudio.com/t/static-inline-variable-gets-destroyed-multiple-tim/297876
#define MPT_WITH_ASIO
#endif
#define MPT_WITH_DMO
#define MPT_WITH_LAME
#define MPT_WITH_LHASA
#define MPT_WITH_MINIZIP
#define MPT_WITH_NLOHMANNJSON
#define MPT_WITH_OPUS
#define MPT_WITH_OPUSENC
#define MPT_WITH_OPUSFILE
#define MPT_WITH_PORTAUDIO
//#define MPT_WITH_PULSEAUDIO
//#define MPT_WITH_PULSEAUDIOSIMPLE
#define MPT_WITH_RTAUDIO
#define MPT_WITH_SMBPITCHSHIFT
#define MPT_WITH_UNRAR
#define MPT_WITH_VORBISENC
// OpenMPT and libopenmpt dependencies (not for openmp123, player plugins or examples)
//#define MPT_WITH_DL
#define MPT_WITH_FLAC
//#define MPT_WITH_LTDL
#if MPT_OS_WINDOWS
#define MPT_WITH_MEDIAFOUNDATION
#endif
//#define MPT_WITH_MINIMP3
//#define MPT_WITH_MINIZ
#define MPT_WITH_MPG123
#define MPT_WITH_OGG
//#define MPT_WITH_STBVORBIS
#define MPT_WITH_VORBIS
#define MPT_WITH_VORBISFILE
#if MPT_OS_WINDOWS
#if (_WIN32_WINNT >= 0x0A00)
#define MPT_WITH_WINDOWS10
#endif
#endif
#define MPT_WITH_ZLIB
#endif // MODPLUG_TRACKER
#if defined(LIBOPENMPT_BUILD)
// OpenMPT and libopenmpt dependencies (not for openmp123, player plugins or examples)
#if defined(LIBOPENMPT_BUILD_FULL) && defined(LIBOPENMPT_BUILD_SMALL)
#error "only one of LIBOPENMPT_BUILD_FULL or LIBOPENMPT_BUILD_SMALL can be defined"
#endif // LIBOPENMPT_BUILD_FULL && LIBOPENMPT_BUILD_SMALL
#if defined(LIBOPENMPT_BUILD_SMALL)
//#define MPT_WITH_DL
//#define MPT_WITH_FLAC
//#define MPT_WITH_LTDL
//#define MPT_WITH_MEDIAFOUNDATION
#define MPT_WITH_MINIMP3
#define MPT_WITH_MINIZ
//#define MPT_WITH_MPG123
//#define MPT_WITH_OGG
#define MPT_WITH_STBVORBIS
//#define MPT_WITH_VORBIS
//#define MPT_WITH_VORBISFILE
//#define MPT_WITH_ZLIB
#else // !LIBOPENMPT_BUILD_SMALL
//#define MPT_WITH_DL
//#define MPT_WITH_FLAC
//#define MPT_WITH_LTDL
//#define MPT_WITH_MEDIAFOUNDATION
//#define MPT_WITH_MINIMP3
//#define MPT_WITH_MINIZ
#define MPT_WITH_MPG123
#define MPT_WITH_OGG
//#define MPT_WITH_STBVORBIS
#define MPT_WITH_VORBIS
#define MPT_WITH_VORBISFILE
#define MPT_WITH_ZLIB
#endif // LIBOPENMPT_BUILD_SMALL
#endif // LIBOPENMPT_BUILD
#endif // MPT_BUILD_MSVC
#if defined(MPT_BUILD_XCODE)
#if defined(MODPLUG_TRACKER)
// n/a
#endif // MODPLUG_TRACKER
#if defined(LIBOPENMPT_BUILD)
//#define MPT_WITH_DL
//#define MPT_WITH_FLAC
//#define MPT_WITH_LTDL
//#define MPT_WITH_MEDIAFOUNDATION
//#define MPT_WITH_MINIMP3
//#define MPT_WITH_MINIZ
#define MPT_WITH_MPG123
#define MPT_WITH_OGG
//#define MPT_WITH_STBVORBIS
#define MPT_WITH_VORBIS
#define MPT_WITH_VORBISFILE
#define MPT_WITH_ZLIB
#endif // LIBOPENMPT_BUILD
#endif // MPT_BUILD_XCODE
#if defined(MODPLUG_TRACKER)
// Enable built-in test suite.
#if defined(MPT_BUILD_DEBUG) || defined(MPT_BUILD_CHECKED)
#define ENABLE_TESTS
#endif
// Disable any file saving functionality (not really useful except for the player library)
//#define MODPLUG_NO_FILESAVE
// Disable any debug logging
//#define NO_LOGGING
#if !defined(MPT_BUILD_DEBUG) && !defined(MPT_BUILD_CHECKED) && !defined(MPT_BUILD_WINESUPPORT)
#define MPT_LOG_GLOBAL_LEVEL_STATIC
#define MPT_LOG_GLOBAL_LEVEL 0
#endif
// Enable all individual logging macros and MPT_LOG calls
//#define MPT_ALL_LOGGING
// Disable all runtime asserts
#if !defined(MPT_BUILD_DEBUG) && !defined(MPT_BUILD_CHECKED) && !defined(MPT_BUILD_WINESUPPORT)
#define NO_ASSERTS
#endif
// Enable callback stream wrapper for FileReader (required by libopenmpt C API).
//#define MPT_FILEREADER_CALLBACK_STREAM
// Support for externally linked samples e.g. in MPTM files
#define MPT_EXTERNAL_SAMPLES
// Support mpt::ChartsetLocale
#define MPT_ENABLE_CHARSET_LOCALE
// Use inline assembly
#define ENABLE_ASM
// Disable unarchiving support
//#define NO_ARCHIVE_SUPPORT
// Disable the built-in reverb effect
//#define NO_REVERB
// Disable built-in miscellaneous DSP effects (surround, mega bass, noise reduction)
//#define NO_DSP
// Disable the built-in equalizer.
//#define NO_EQ
// Disable the built-in automatic gain control
//#define NO_AGC
// Define to build without VST plugin support; makes build possible without VST SDK.
//#define NO_VST
// (HACK) Define to build without any plugin support
//#define NO_PLUGINS
// Do not build libopenmpt C api
#define NO_LIBOPENMPT_C
// Do not build libopenmpt C++ api
#define NO_LIBOPENMPT_CXX
#endif // MODPLUG_TRACKER
#if defined(LIBOPENMPT_BUILD)
#if (defined(_DEBUG) || defined(DEBUG)) && !defined(MPT_BUILD_DEBUG)
#define MPT_BUILD_DEBUG
#endif
#if defined(LIBOPENMPT_BUILD_TEST)
#define ENABLE_TESTS
#else
#define MODPLUG_NO_FILESAVE
#endif
#if defined(MPT_BUILD_ANALZYED) || defined(MPT_BUILD_DEBUG) || defined(MPT_BUILD_CHECKED) || defined(ENABLE_TESTS)
// enable asserts
#else
#define NO_ASSERTS
#endif
//#define NO_LOGGING
//#define MPT_ALL_LOGGING
#define MPT_FILEREADER_CALLBACK_STREAM
//#define MPT_EXTERNAL_SAMPLES
#if defined(ENABLE_TESTS) || defined(MPT_BUILD_HACK_ARCHIVE_SUPPORT)
#define MPT_ENABLE_CHARSET_LOCALE
#else
//#define MPT_ENABLE_CHARSET_LOCALE
#endif
// Do not use inline asm in library builds. There is just about no codepath which would use it anyway.
//#define ENABLE_ASM
#if defined(MPT_BUILD_HACK_ARCHIVE_SUPPORT)
//#define NO_ARCHIVE_SUPPORT
#else
#define NO_ARCHIVE_SUPPORT
#endif
//#define NO_REVERB
#define NO_DSP
#define NO_EQ
#define NO_AGC
#define NO_VST
//#define NO_PLUGINS
//#define NO_LIBOPENMPT_C
//#define NO_LIBOPENMPT_CXX
#endif // LIBOPENMPT_BUILD
#if MPT_OS_WINDOWS
#ifndef MPT_ENABLE_CHARSET_LOCALE
#define MPT_ENABLE_CHARSET_LOCALE
#endif
#elif MPT_OS_LINUX
#elif MPT_OS_ANDROID
#elif MPT_OS_EMSCRIPTEN
#ifndef MPT_LOCALE_ASSUME_CHARSET
#define MPT_LOCALE_ASSUME_CHARSET Charset::UTF8
#endif
#elif MPT_OS_MACOSX_OR_IOS
#elif MPT_OS_DJGPP
#ifndef MPT_LOCALE_ASSUME_CHARSET
#define MPT_LOCALE_ASSUME_CHARSET Charset::CP437
#endif
#endif
#if MPT_COMPILER_MSVC && !defined(MPT_USTRING_MODE_UTF8_FORCE)
// Use wide strings for MSVC because this is the native encoding on
// microsoft platforms.
#define MPT_USTRING_MODE_WIDE 1
#define MPT_USTRING_MODE_UTF8 0
#else // !MPT_COMPILER_MSVC
#define MPT_USTRING_MODE_WIDE 0
#define MPT_USTRING_MODE_UTF8 1
#endif // MPT_COMPILER_MSVC
#if MPT_USTRING_MODE_UTF8
// MPT_USTRING_MODE_UTF8 mpt::ustring is implemented via mpt::u8string
#define MPT_ENABLE_U8STRING 1
#else
#define MPT_ENABLE_U8STRING 0
#endif
#if defined(MODPLUG_TRACKER) || MPT_USTRING_MODE_WIDE
// mpt::ToWString, mpt::wfmt, ConvertStrTo<std::wstring>
// Required by the tracker to ease interfacing with WinAPI.
// Required by MPT_USTRING_MODE_WIDE to ease type tunneling in mpt::format.
#define MPT_WSTRING_FORMAT 1
#else
#define MPT_WSTRING_FORMAT 0
#endif
#if MPT_OS_WINDOWS || MPT_USTRING_MODE_WIDE || MPT_WSTRING_FORMAT
// mpt::ToWide
// Required on Windows by mpt::PathString.
// Required by MPT_USTRING_MODE_WIDE as they share the conversion functions.
// Required by MPT_WSTRING_FORMAT because of std::string<->std::wstring conversion in mpt::ToString and mpt::ToWString.
#define MPT_WSTRING_CONVERT 1
#else
#define MPT_WSTRING_CONVERT 0
#endif
// fixing stuff up
#if defined(MPT_BUILD_ANALYZED) || defined(MPT_BUILD_CHECKED)
#ifdef NO_ASSERTS
#undef NO_ASSERTS // static or dynamic analyzers want assertions on
#endif
#endif
#if defined(MPT_BUILD_FUZZER)
#ifndef MPT_FUZZ_TRACKER
#define MPT_FUZZ_TRACKER
#endif
#endif
#if !MPT_COMPILER_MSVC && defined(ENABLE_ASM)
#undef ENABLE_ASM // inline assembly requires MSVC compiler
#endif
#if defined(ENABLE_ASM)
#if MPT_COMPILER_MSVC && defined(_M_IX86)
#define ENABLE_CPUID
// Generate general x86 inline assembly and intrinsics.
#define ENABLE_X86
// Generate MMX instructions (only used when the CPU supports it).
#define ENABLE_MMX
// Generate SSE instructions (only used when the CPU supports it).
#define ENABLE_SSE
// Generate SSE2 instructions (only used when the CPU supports it).
#define ENABLE_SSE2
// Generate SSE3 instructions (only used when the CPU supports it).
#define ENABLE_SSE3
// Generate SSE4 instructions (only used when the CPU supports it).
#define ENABLE_SSE4
// Generate AVX instructions (only used when the CPU supports it).
#define ENABLE_AVX
// Generate AVX2 instructions (only used when the CPU supports it).
#define ENABLE_AVX2
#elif MPT_COMPILER_MSVC && defined(_M_X64)
#define ENABLE_CPUID
// Generate general x64 intrinsics.
#define ENABLE_X64
// Generate SSE instructions (only used when the CPU supports it).
#define ENABLE_SSE
// Generate SSE2 instructions (only used when the CPU supports it).
#define ENABLE_SSE2
// Generate SSE3 instructions (only used when the CPU supports it).
#define ENABLE_SSE3
// Generate SSE4 instructions (only used when the CPU supports it).
#define ENABLE_SSE4
// Generate AVX instructions (only used when the CPU supports it).
#define ENABLE_AVX
// Generate AVX2 instructions (only used when the CPU supports it).
#define ENABLE_AVX2
#endif // arch
#endif // ENABLE_ASM
#if defined(ENABLE_TESTS) && defined(MODPLUG_NO_FILESAVE)
#undef MODPLUG_NO_FILESAVE // tests recommend file saving
#endif
#if defined(MPT_WITH_ZLIB) && defined(MPT_WITH_MINIZ)
// Only one deflate implementation should be used. Prefer zlib.
#undef MPT_WITH_MINIZ
#endif
#if !MPT_OS_WINDOWS && defined(MPT_WITH_MEDIAFOUNDATION)
#undef MPT_WITH_MEDIAFOUNDATION // MediaFoundation requires Windows
#endif
#if !MPT_COMPILER_MSVC && !MPT_COMPILER_CLANG && defined(MPT_WITH_MEDIAFOUNDATION)
#undef MPT_WITH_MEDIAFOUNDATION // MediaFoundation requires MSVC or Clang due to ATL (no MinGW support)
#endif
#if defined(MPT_WITH_MEDIAFOUNDATION) && !defined(MPT_ENABLE_TEMPFILE)
#define MPT_ENABLE_TEMPFILE
#endif
#if defined(MODPLUG_TRACKER) && !defined(MPT_ENABLE_TEMPFILE)
#define MPT_ENABLE_TEMPFILE
#endif
#if defined(MODPLUG_TRACKER) && !defined(MPT_ENABLE_DYNBIND)
#define MPT_ENABLE_DYNBIND // Tracker requires dynamic library loading for export codecs
#endif
#if defined(MPT_WITH_MEDIAFOUNDATION) && !defined(MPT_ENABLE_DYNBIND)
#define MPT_ENABLE_DYNBIND // MediaFoundation needs dynamic loading in order to test availability of delay loaded libs
#endif
#if (defined(MPT_WITH_MPG123) || defined(MPT_WITH_MINIMP3)) && !defined(MPT_ENABLE_MP3_SAMPLES)
#define MPT_ENABLE_MP3_SAMPLES
#endif
#if defined(ENABLE_TESTS)
#define MPT_ENABLE_FILEIO // Test suite requires PathString for file loading.
#endif
#if defined(MODPLUG_TRACKER) && !defined(MPT_ENABLE_FILEIO)
#define MPT_ENABLE_FILEIO // Tracker requires disk file io
#endif
#if defined(MODPLUG_TRACKER) && !defined(MPT_ENABLE_THREAD)
#define MPT_ENABLE_THREAD // Tracker requires threads
#endif
#if defined(MPT_EXTERNAL_SAMPLES) && !defined(MPT_ENABLE_FILEIO)
#define MPT_ENABLE_FILEIO // External samples require disk file io
#endif
#if defined(NO_PLUGINS)
// Any plugin type requires NO_PLUGINS to not be defined.
#define NO_VST
#endif
#if defined(ENABLE_ASM) || !defined(NO_VST)
#define MPT_ENABLE_ALIGNED_ALLOC
#endif
#if defined(MODPLUG_TRACKER) && !defined(MPT_BUILD_WINESUPPORT) && !defined(MPT_BUILD_WINESUPPORT_WRAPPER)
#ifndef MPT_NO_NAMESPACE
#define MPT_NO_NAMESPACE
#endif
#endif
#if defined(MPT_NO_NAMESPACE)
#ifdef OPENMPT_NAMESPACE
#undef OPENMPT_NAMESPACE
#endif
#define OPENMPT_NAMESPACE
#ifdef OPENMPT_NAMESPACE_BEGIN
#undef OPENMPT_NAMESPACE_BEGIN
#endif
#define OPENMPT_NAMESPACE_BEGIN
#ifdef OPENMPT_NAMESPACE_END
#undef OPENMPT_NAMESPACE_END
#endif
#define OPENMPT_NAMESPACE_END
#else
#ifndef OPENMPT_NAMESPACE
#define OPENMPT_NAMESPACE OpenMPT
#endif
#ifndef OPENMPT_NAMESPACE_BEGIN
#define OPENMPT_NAMESPACE_BEGIN namespace OPENMPT_NAMESPACE {
#endif
#ifndef OPENMPT_NAMESPACE_END
#define OPENMPT_NAMESPACE_END }
#endif
#endif
// platform configuration
#ifdef MPT_WITH_MFC
//#define MPT_MFC_FULL // use full MFC, including MFC controls
#endif // MPT_WITH_MFC
#if defined(MODPLUG_TRACKER)
#if MPT_OS_WINDOWS
#if !defined(MPT_BUILD_WINESUPPORT)
#ifndef MPT_MFC_FULL
#define _AFX_NO_MFC_CONTROLS_IN_DIALOGS // Do not include support for MFC controls in dialogs (reduces binary bloat; remove this #define if you want to use MFC controls)
#endif // !MPT_MFC_FULL
#endif // !MPT_BUILD_WINESUPPORT
#endif // MPT_OS_WINDOWS
#endif // MODPLUG_TRACKER
#if MPT_OS_WINDOWS
#define WIN32_LEAN_AND_MEAN
// windows.h excludes
#define NOMEMMGR // GMEM_*, LMEM_*, GHND, LHND, associated routines
#define NOMINMAX // Macros min(a,b) and max(a,b)
#define NOSERVICE // All Service Controller routines, SERVICE_ equates, etc.
#define NOCOMM // COMM driver routines
#define NOKANJI // Kanji support stuff.
#define NOPROFILER // Profiler interface.
#define NOMCX // Modem Configuration Extensions
// mmsystem.h excludes
#define MMNODRV
//#define MMNOSOUND
//#define MMNOWAVE
//#define MMNOMIDI
#define MMNOAUX
#define MMNOMIXER
//#define MMNOTIMER
#define MMNOJOY
#define MMNOMCI
//#define MMNOMMIO
//#define MMNOMMSYSTEM
// mmreg.h excludes
#define NOMMIDS
//#define NONEWWAVE
#define NONEWRIFF
#define NOJPEGDIB
#define NONEWIC
#define NOBITMAP
#endif // MPT_OS_WINDOWS
// stdlib configuration
#if MPT_COMPILER_CLANG
#pragma clang diagnostic push
#pragma clang diagnostic ignored "-Wreserved-id-macro"
#endif
#define __STDC_CONSTANT_MACROS
#define __STDC_LIMIT_MACROS
#define _USE_MATH_DEFINES
#ifndef _FILE_OFFSET_BITS
#define _FILE_OFFSET_BITS 64
#endif
#if MPT_COMPILER_CLANG
#pragma clang diagnostic pop
#endif
// compiler configuration
#if MPT_COMPILER_MSVC
#define VC_EXTRALEAN // Exclude rarely-used stuff from Windows headers
#ifndef _CRT_SECURE_NO_WARNINGS
#define _CRT_SECURE_NO_WARNINGS // Define to disable the "This function or variable may be unsafe" warnings.
#endif
#define _CRT_SECURE_CPP_OVERLOAD_STANDARD_NAMES 1
#define _CRT_SECURE_CPP_OVERLOAD_STANDARD_NAMES_COUNT 1
#ifndef _SCL_SECURE_NO_WARNINGS
#define _SCL_SECURE_NO_WARNINGS
#endif
#ifndef NO_WARN_MBCS_MFC_DEPRECATION
#define NO_WARN_MBCS_MFC_DEPRECATION
#endif
#pragma warning(disable:4355) // 'this' : used in base member initializer list
// happens for immutable classes (i.e. classes containing const members)
#pragma warning(disable:4512) // assignment operator could not be generated
#pragma warning(error:4309) // Treat "truncation of constant value"-warning as error.
#pragma warning(error:4463) // Treat overflow; assigning value to bit-field that can only hold values from low_value to high_value"-warning as error.
#ifdef MPT_BUILD_ANALYZED
// Disable Visual Studio static analyzer warnings that generate too many false positives in VS2010.
//#pragma warning(disable:6246)
//#pragma warning(disable:6262)
#pragma warning(disable:6297) // 32-bit value is shifted, then cast to 64-bit value. Results might not be an expected value.
#pragma warning(disable:6326) // Potential comparison of a constant with another constant
//#pragma warning(disable:6385)
//#pragma warning(disable:6386)
#endif // MPT_BUILD_ANALYZED
#endif // MPT_COMPILER_MSVC
#if MPT_COMPILER_CLANG
#if defined(MPT_BUILD_MSVC)
#pragma clang diagnostic warning "-Wimplicit-fallthrough"
#endif // MPT_BUILD_MSVC
#if defined(MODPLUG_TRACKER)
#pragma clang diagnostic ignored "-Wunused-local-typedef"
#endif // MODPLUG_TRACKER
#endif // MPT_COMPILER_CLANG
// standard library quirks
// third-party library configuration
#ifdef MPT_WITH_FLAC
#ifdef MPT_BUILD_MSVC_STATIC
#define FLAC__NO_DLL
#endif
#endif
#ifdef MPT_WITH_SMBPITCHSHIFT
#ifdef MPT_BUILD_MSVC_SHARED
#define SMBPITCHSHIFT_USE_DLL
#endif
#endif
#ifdef MPT_WITH_STBVORBIS
#define STB_VORBIS_HEADER_ONLY
#ifndef STB_VORBIS_NO_PULLDATA_API
#define STB_VORBIS_NO_PULLDATA_API
#endif
#ifndef STB_VORBIS_NO_STDIO
#define STB_VORBIS_NO_STDIO
#endif
#endif
#ifdef MPT_WITH_VORBISFILE
#ifndef OV_EXCLUDE_STATIC_CALLBACKS
#define OV_EXCLUDE_STATIC_CALLBACKS
#endif
#endif
#ifdef MPT_WITH_ZLIB
#ifdef MPT_BUILD_MSVC_SHARED
#define ZLIB_DLL
#endif
#endif