scummsys.h

/* ScummVM - Graphic Adventure Engine
 *
 * ScummVM is the legal property of its developers, whose names
 * are too numerous to list here. Please refer to the COPYRIGHT
 * file distributed with this source distribution.
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 *
 */

#ifndef COMMON_SCUMMSYS_H
#define COMMON_SCUMMSYS_H

#ifndef __has_feature           // Optional of course.
    #define __has_feature(x) 0  // Compatibility with non-clang compilers.
#endif

// This is a convenience macro to test whether the compiler used is a GCC
// version, which is at least major.minor.  Note that Clang will also define
// it and report itself as GCC 4.2.1.
#ifdef __GNUC__
    #define GCC_ATLEAST(major, minor) (__GNUC__ > (major) || (__GNUC__ == (major) && __GNUC_MINOR__ >= (minor)))
#else
    #define GCC_ATLEAST(major, minor) 0
#endif

#if defined(NONSTANDARD_PORT)

    // Ports which need to perform #includes and #defines visible in
    // virtually all the source of ScummVM should do so by providing a
    // "portdefs.h" header file (and not by directly modifying this
    // header file).
    #include <portdefs.h>
#else // defined(NONSTANDARD_PORT)

    #if defined(WIN32)

        #if defined(_MSC_VER) && _MSC_VER <= 1800

        // FIXME: The placement of the workaround functions for MSVC below
        // require us to include stdio.h and stdarg.h for MSVC here. This
        // is not exactly nice...
        // We should think of a better way of doing this.
        #include <stdio.h>
        #include <stdarg.h>

        // MSVC's vsnprintf is either non-existent (2003) or bugged since it
        // does not always include a terminating NULL (2005+). To work around
        // that we fix up the _vsnprintf included. Note that the return value
        // will still not match C99's specs!
        inline int vsnprintf_msvc(char *str, size_t size, const char *format, va_list args) {
            // We do not pass size - 1 here, to ensure we would get the same
            // return value as when we would use _vsnprintf directly, since
            // for example Common::String::format relies on this.
            int retValue = _vsnprintf(str, size, format, args);
            str[size - 1] = 0;
            return retValue;
        }

        #define vsnprintf vsnprintf_msvc

        // Visual Studio does not include snprintf in its standard C library.
        // Instead it includes a function called _snprintf with somewhat
        // similar semantics. The minor difference is that the return value in
        // case the formatted string exceeds the buffer size is different.
        // A much more dangerous one is that _snprintf does not always include
        // a terminating null (Whoops!). Instead we map to our fixed vsnprintf.
        inline int snprintf(char *str, size_t size, const char *format, ...) {
            va_list args;
            va_start(args, format);
            int len = vsnprintf(str, size, format, args);
            va_end(args);
            return len;
        }
        #endif

        #define WIN32_LEAN_AND_MEAN     // Exclude rarely-used stuff from Windows headers
        #define NOGDICAPMASKS
        #define OEMRESOURCE
        #define NONLS
        #define NOICONS
        #define NOMCX
        #define NOPROFILER
        #define NOKANJI
        #define NOSERVICE
        #define NOMETAFILE
        #define NOCOMM
        #define NOCRYPT
        #define NOIME
        #define NOATOM
        #define NOCTLMGR
        #define NOCLIPBOARD
        #define NOMEMMGR
        #define NOSYSMETRICS
        #define NOMENUS
        #define NOOPENFILE
        #define NOWH
        #define NOSOUND
        #define NODRAWTEXT
        #define NOMINMAX 1

    #endif

    #if defined(__QNXNTO__)
    #include <strings.h>    /* For strcasecmp */
    #endif

    #include <stdio.h>
    #include <stdlib.h>
    #include <string.h>
    #include <stdarg.h>
    #include <stddef.h>
    #include <assert.h>
    #include <ctype.h>
    #include <limits.h>
    // MSVC does not define M_PI, M_SQRT2 and other math defines by default.
    // _USE_MATH_DEFINES must be defined in order to have these defined, thus
    // we enable it here. For more information, check:
    // https://docs.microsoft.com/en-us/cpp/c-runtime-library/math-constants
    #define _USE_MATH_DEFINES
    #include <math.h>

    // FIXME: We sadly can't assume standard C++ headers to be present on every
    // system we support, so we should get rid of this. The solution should be to
    // write a simple placement new on our own. It might be noteworthy we can't
    // easily do that for systems which do have a <new>, since it might clash with
    // the default definition otherwise!
    #include <new>

    // After having discussion about use of std::numeric_limits in
    // https://github.com/scummvm/scummvm/pull/3966 we concluded that it is safe to
    // use it as minimal STL code with low probability to bring any incompatibilities
    #include <limits>
#endif

#ifndef STATIC_ASSERT
#if __cplusplus >= 201103L || (defined(_MSC_VER) && _MSC_VER > 1600)

    #define STATIC_ASSERT(expression, message) \
        static_assert((expression), #message)
#else

    #define STATIC_ASSERT(expression, message) \
        do { \
            extern int STATIC_ASSERT_##message[(expression) ? 1 : -1]; \
            (void)(STATIC_ASSERT_##message); \
        } while (false)
#endif
#endif

// The following math constants are usually defined by the system math.h header, but
// they are not part of the ANSI C++ standards and so can NOT be relied upon to be
// present i.e. when -std=c++11 is passed to GCC, enabling strict ANSI compliance.
// As we rely on these being present, we define them if they are not set.

#ifndef M_E
    #define M_E 2.7182818284590452354 /* e */
#endif

#ifndef M_LOG2E
    #define M_LOG2E 1.4426950408889634074 /* log_2 e */
#endif

#ifndef M_LOG10E
    #define M_LOG10E 0.43429448190325182765 /* log_10 e */
#endif

#ifndef M_LN2
    #define M_LN2 0.69314718055994530942 /* log_e 2 */
#endif

#ifndef M_LN10
    #define M_LN10 2.30258509299404568402 /* log_e 10 */
#endif

#ifndef M_PI
    #define M_PI 3.14159265358979323846 /* pi */
#endif

#ifndef M_PI_2
    #define M_PI_2 1.57079632679489661923 /* pi/2 */
#endif

#ifndef M_PI_4
    #define M_PI_4 0.78539816339744830962 /* pi/4 */
#endif

#ifndef M_1_PI
    #define M_1_PI 0.31830988618379067154 /* 1/pi */
#endif

#ifndef M_2_PI
    #define M_2_PI 0.63661977236758134308 /* 2/pi */
#endif

#ifndef M_2_SQRTPI
    #define M_2_SQRTPI 1.12837916709551257390 /* 2/sqrt(pi) */
#endif

#ifndef M_SQRT2
    #define M_SQRT2 1.41421356237309504880 /* sqrt(2) */
#endif

#ifndef M_SQRT1_2
    #define M_SQRT1_2 0.70710678118654752440 /* 1/sqrt(2) */
#endif

// Use config.h, generated by configure
#if defined(HAVE_CONFIG_H)
#include "config.h"
#endif


// In the following we configure various targets, in particular those
// which can't use our "configure" tool and hence don't use config.h.
//
// Some #defines that occur here frequently:
// SCUMM_LITTLE_ENDIAN
//    - Define this on a little endian target
// SCUMM_BIG_ENDIAN
//    - Define this on a big endian target
// SCUMM_NEED_ALIGNMENT
//    - Define this if your system has problems reading e.g. an int32 from an odd address
// SMALL_SCREEN_DEVICE
//    - ...
// ...


//
// By default we try to use pragma push/pop to ensure various structs we use
// are "packed". If your compiler doesn't support this pragma, you are in for
// a problem. If you are lucky, there is a compiler switch, or another pragma,
// doing the same thing -- in that case, try to modify common/pack-begin.h and
// common/pack-end.h accordingly. Or maybe your port simply *always* packs
// everything, in which case you could #undefine SCUMMVM_USE_PRAGMA_PACK.
//
// If neither is possible, tough luck. Try to contact the team, maybe we can
// come up with a solution, though I wouldn't hold my breath on it :-/.
//
#define SCUMMVM_USE_PRAGMA_PACK

//
// Determine the host endianess and whether memory alignment is required.
//
#if !defined(HAVE_CONFIG_H)

    // If -fsanitize=undefined or -fsanitize=alignment is in use, and the
    // compiler happens to report it, make sure SCUMM_NEED_ALIGNMENT is
    // defined, in order to avoid false positives when not using the
    // "configure" script to enable UBSan.
    #if __has_feature(undefined_behavior_sanitizer)
        #define SCUMM_NEED_ALIGNMENT
    #endif

    #if defined(__DC__) || \
          defined(__DS__) || \
          defined(__3DS__) || \
          defined(IPHONE) || \
          defined(__PSP__)

        #define SCUMM_LITTLE_ENDIAN
        #define SCUMM_NEED_ALIGNMENT

    #elif defined(_MSC_VER) || defined(__MINGW32__)

        #define SCUMM_LITTLE_ENDIAN

    #elif defined(__MORPHOS__) || defined(__amigaos4__) || defined(__N64__) || defined(__WII__)

        #define SCUMM_BIG_ENDIAN
        #define SCUMM_NEED_ALIGNMENT

    #elif defined(SDL_BACKEND)
        // On SDL based ports, we try to use SDL_BYTEORDER to determine the
        // endianess. We explicitly do this as the *last* thing we try, so that
        // platform specific settings have precedence.
        #include <SDL_endian.h>

        #if SDL_BYTEORDER == SDL_LIL_ENDIAN
        #define SCUMM_LITTLE_ENDIAN
        #elif SDL_BYTEORDER == SDL_BIG_ENDIAN
        #define SCUMM_BIG_ENDIAN
        #else
        #error Neither SDL_BIG_ENDIAN nor SDL_LIL_ENDIAN is set.
        #endif

    #else

        #error No system type defined, host endianess unknown.

    #endif
#endif

#if !defined(SCUMM_FLOAT_WORD_LITTLE_ENDIAN) && !defined(SCUMM_FLOAT_WORD_BIG_ENDIAN)

    #if defined(__ORDER_LITTLE_ENDIAN__) && defined(__ORDER_BIG_ENDIAN__) && defined(__FLOAT_WORD_ORDER__)

        #if (__FLOAT_WORD_ORDER__ == __ORDER_LITTLE_ENDIAN__)
            #define SCUMM_FLOAT_WORD_LITTLE_ENDIAN
        #elif (__FLOAT_WORD_ORDER__ == __ORDER_BIG_ENDIAN__)
            #define SCUMM_FLOAT_WORD_BIG_ENDIAN
        #else
            #error Unsupported endianness
        #endif

    #else
        #ifdef SCUMM_LITTLE_ENDIAN
            #define SCUMM_FLOAT_WORD_LITTLE_ENDIAN
        #else
            #define SCUMM_FLOAT_WORD_BIG_ENDIAN
        #endif

    #endif
#endif

//
// Some more system specific settings.
// TODO/FIXME: All of these should be moved to backend specific files (such as portdefs.h)
//
#if defined(DINGUX)

    // Very BAD hack following, used to avoid triggering an assert in uClibc dingux library
    // "toupper" when pressing keyboard function keys.
    #undef toupper
    #define toupper(c) __extension__ ({ auto _x = ((c) & 0xFF); (_x >= 97 && _x <= 122) ? (_x - 32) : _x; })

#elif defined(__PSP__)

    #include <malloc.h>
    #include "backends/platform/psp/memory.h"

    /* to make an efficient, inlined memcpy implementation */
    #define memcpy(dst, src, size)   psp_memcpy(dst, src, size)

#endif

#if defined(USE_TREMOR) && !defined(USE_VORBIS)
#define USE_VORBIS // make sure this one is defined together with USE_TREMOR!
#endif

//
// Fallbacks / default values for various special macros
//
#ifndef GCC_PRINTF
    #if defined(__GNUC__) || defined(__INTEL_COMPILER)
        #if defined(__USE_MINGW_ANSI_STDIO) && __USE_MINGW_ANSI_STDIO && !defined(__clang__)
            #define GCC_PRINTF(x,y) __attribute__((__format__(__gnu_printf__, x, y)))
        #else
            #define GCC_PRINTF(x,y) __attribute__((__format__(__printf__, x, y)))
        #endif
    #else
        #define GCC_PRINTF(x,y)
    #endif
#endif

#ifndef MSVC_PRINTF
    #if defined(_MSC_VER) && _MSC_VER > 1400
        #define MSVC_PRINTF _Printf_format_string_
    #else
        #define MSVC_PRINTF
    #endif
#endif

#ifndef PACKED_STRUCT
    #if defined(__GNUC__) || defined(__INTEL_COMPILER)
        #define PACKED_STRUCT __attribute__((__packed__))
    #else
        #define PACKED_STRUCT
    #endif
#endif

#ifndef FORCEINLINE
    #if defined(_MSC_VER)
        #define FORCEINLINE __forceinline
    #elif defined(__GNUC__)
        #define FORCEINLINE inline __attribute__((__always_inline__))
    #else
        #define FORCEINLINE inline
    #endif
#endif

#ifndef PLUGIN_EXPORT
    #if defined(_MSC_VER) || defined(__MINGW32__)
        #define PLUGIN_EXPORT __declspec(dllexport)
    #else
        #define PLUGIN_EXPORT
    #endif
#endif

#ifndef NORETURN_PRE
    #if defined(_MSC_VER)
        #define NORETURN_PRE __declspec(noreturn)
    #elif defined(__GNUC__)
        #define NORETURN_PRE __attribute__((__noreturn__))
    #else
        #define NORETURN_PRE
    #endif
#endif

#ifndef NORETURN_POST
    #if defined(__INTEL_COMPILER)
        #define NORETURN_POST __attribute__((__noreturn__))
    #else
        #define NORETURN_POST
    #endif
#endif

#ifndef WARN_UNUSED_RESULT
    #if __cplusplus >= 201703L
        #define WARN_UNUSED_RESULT [[nodiscard]]
    #elif defined(__GNUC__)
        #define WARN_UNUSED_RESULT __attribute__((__warn_unused_result__))
    #elif defined(_Check_return_)
        #define WARN_UNUSED_RESULT _Check_return_
    #else
        #define WARN_UNUSED_RESULT
    #endif
#endif

#ifndef WARN_DEPRECATED
    #if __cplusplus >= 201703L
        #define WARN_DEPRECATED(msg) [[deprecated(msg)]]
    #elif defined(__GNUC__)
        #define WARN_DEPRECATED(msg) __attribute__((__deprecated__(msg)))
    #elif defined(_MSC_VER)
        #define WARN_DEPRECATED(msg) __declspec(deprecated(msg))
    #else
        #define WARN_DEPRECATED(msg)
    #endif
#endif

#ifndef STRINGBUFLEN
    #if defined(__N64__) || defined(__DS__) || defined(__3DS__)
        #define STRINGBUFLEN 256
    #else
        #define STRINGBUFLEN 1024
    #endif
#endif

#ifndef MAXPATHLEN
#define MAXPATHLEN 256
#endif

#ifndef scumm_va_copy
    #if defined(va_copy)
        #define scumm_va_copy va_copy
    #elif defined(__va_copy)
        #define scumm_va_copy __va_copy
    #elif defined(_MSC_VER)
        #define scumm_va_copy(dst, src)       ((dst) = (src))
    #else
        #error scumm_va_copy undefined for this port
    #endif
#endif



//
// Typedef our system types unless they have already been defined by config.h,
// or SCUMMVM_DONT_DEFINE_TYPES is set.
//
#if !defined(HAVE_CONFIG_H) && !defined(SCUMMVM_DONT_DEFINE_TYPES)
    typedef unsigned char byte;
    typedef unsigned char uint8;
    typedef signed char int8;
    typedef unsigned short uint16;
    typedef signed short int16;
    // HACK: Some ports, such as NDS and AmigaOS, are not frequently
    // tested during development, but cause frequent buildbot failures
    // because they need to use 'long' for int32. Windows 32-bit
    // binaries have this nice property of being easy to build, having
    // a 32-bit 'long' too, *and* being frequently tested (incl. Github
    // Actions). We want to catch this case as early and frequently
    // as possible, so Win32 is probably the best candidate for this...
    #if defined(WIN32) && !defined(_WIN64)
    typedef unsigned long uint32;
    typedef signed long int32;
    #else
    typedef unsigned int uint32;
    typedef signed int int32;
    #endif
    typedef unsigned int uint;
    typedef signed long long int64;
    typedef unsigned long long uint64;
#endif

//
// Determine 64 bitness
// Reference: https://web.archive.org/web/20190413073704/http://nadeausoftware.com/articles/2012/02/c_c_tip_how_detect_processor_type_using_compiler_predefined_macros
//
#if !defined(HAVE_CONFIG_H)

#if defined(__x86_64__) || \
          defined(_M_X64) || \
          defined(__ppc64__) || \
          defined(__powerpc64__) || \
          defined(__LP64__) || \
          defined(_M_ARM64)

typedef int64 intptr;
typedef uint64 uintptr;

#else

typedef int32 intptr;
typedef uint32 uintptr;

#endif

#endif

//
// std::nullptr_t when this type is not available
//
#if defined(NO_CXX11_NULLPTR_T)
namespace std {
    typedef decltype(nullptr) nullptr_t;
}
#endif

//
// std::initializer_list
// Provide replacement when not available
//
#if defined(NO_CXX11_INITIALIZER_LIST)
namespace std {
    template<class T> class initializer_list {
    public:
        typedef T value_type;
        typedef const T &reference;
        typedef const T &const_reference;
        typedef size_t size_type;
        typedef const T *iterator;
        typedef const T *const_iterator;

        constexpr initializer_list() noexcept = default;
        constexpr size_t size() const noexcept { return _size; };
        constexpr const T *begin() const noexcept { return _begin; };
        constexpr const T *end() const noexcept { return _begin + _size; }

    private:
        // Note: begin has to be first or the compiler may get very upset
        const T *_begin = { nullptr };
        size_t _size = { 0 };

        // The compiler is allowed to call this constructor
        constexpr initializer_list(const T* t, size_t s) noexcept : _begin(t) , _size(s) {}
    };

    template<class T> constexpr const T* begin(initializer_list<T> il) noexcept {
        return il.begin();
    }

    template<class T> constexpr const T* end(initializer_list<T> il) noexcept {
        return il.end();
    }
}

#else

#include <initializer_list>

#endif // NO_CXX11_INITIALIZER_LIST

#include "common/forbidden.h"

#endif