qglobal.cpp

QT 开发环境里面一个很重要的文件

            winver = QSysInfo::WV_98;
        else
            winver = QSysInfo::WV_95;
        break;
#ifdef Q_OS_TEMP
    case VER_PLATFORM_WIN32_CE:
#ifdef Q_OS_TEMP
        if (qt_cever >= 400)
            winver = QSysInfo::WV_CENET;
        else
#endif
            winver = QSysInfo::WV_CE;
        break;
#endif
    default: // VER_PLATFORM_WIN32_NT
        if (osver.dwMajorVersion < 5) {
            winver = QSysInfo::WV_NT;
        } else if (osver.dwMajorVersion == 6) {
            winver = QSysInfo::WV_VISTA;
        } else if (osver.dwMinorVersion == 0) {
            winver = QSysInfo::WV_2000;
        } else if (osver.dwMinorVersion == 1) {
            winver = QSysInfo::WV_XP;
        } else if (osver.dwMinorVersion == 2) {
            winver = QSysInfo::WV_2003;
        } else {
            qWarning("Qt: Untested Windows version detected!");
            winver = QSysInfo::WV_NT_based;
        }
    }

#ifdef QT_DEBUG
    {
        QByteArray override = qgetenv("QT_WINVER_OVERRIDE");
        if (override.isEmpty())
            return winver;

        if (override == "Me")
            winver = QSysInfo::WV_Me;
        if (override == "95")
            winver = QSysInfo::WV_95;
        else if (override == "98")
            winver = QSysInfo::WV_98;
        else if (override == "NT")
            winver = QSysInfo::WV_NT;
        else if (override == "2000")
            winver = QSysInfo::WV_2000;
        else if (override == "2003")
            winver = QSysInfo::WV_2003;
        else if (override == "XP")
            winver = QSysInfo::WV_XP;
        else if (override == "VISTA")
            winver = QSysInfo::WV_VISTA;
    }
#endif

    return winver;
}

const QSysInfo::WinVersion QSysInfo::WindowsVersion = winVersion();

#endif


/*!
    \macro void Q_ASSERT(bool test)
    \relates <QtGlobal>

    Prints a warning message containing the source code file name and
    line number if \a test is false.

    Q_ASSERT() is useful for testing pre- and post-conditions
    during development. It does nothing if \c QT_NO_DEBUG was defined
    during compilation.

    Example:

    \code
        // File: div.cpp

        #include <QtGlobal>

        int divide(int a, int b)
        {
            Q_ASSERT(b != 0);
            return a / b;
        }
    \endcode

    If \c b is zero, the Q_ASSERT statement will output the following
    message using the qFatal() function:

    \code
        ASSERT: "b == 0" in file div.cpp, line 7
    \endcode

    \sa Q_ASSERT_X(), qFatal(), {Debugging Techniques}
*/

/*!
    \macro void Q_ASSERT_X(bool test, const char *where, const char *what)
    \relates <QtGlobal>

    Prints the message \a what together with the location \a where,
    the source file name and line number if \a test is false.

    Q_ASSERT_X is useful for testing pre- and post-conditions during
    development. It does nothing if \c QT_NO_DEBUG was defined during
    compilation.

    Example:

    \code
        // File: div.cpp

        #include <QtGlobal>

        int divide(int a, int b)
        {
            Q_ASSERT_X(b != 0, "divide", "division by zero");
            return a / b;
        }
    \endcode

    If \c b is zero, the Q_ASSERT_X statement will output the following
    message using the qFatal() function:

    \code
        ASSERT failure in divide: "division by zero", file div.cpp, line 7
    \endcode

    \sa Q_ASSERT(), qFatal(), {Debugging Techniques}
*/

/*!
    \macro void Q_CHECK_PTR(void *pointer)
    \relates <QtGlobal>

    If \a pointer is 0, prints a warning message containing the source
    code's file name and line number, saying that the program ran out
    of memory.

    Q_CHECK_PTR does nothing if \c QT_NO_DEBUG was defined during
    compilation.

    Example:

    \code
        int *a;

        Q_CHECK_PTR(a = new int[80]);   // WRONG!

        a = new (nothrow) int[80];      // Right
        Q_CHECK_PTR(a);
    \endcode

    \sa qWarning(), {Debugging Techniques}
*/


/*
  The Q_CHECK_PTR macro calls this function if an allocation check
  fails.
*/
void qt_check_pointer(const char *n, int l)
{
    qWarning("In file %s, line %d: Out of memory", n, l);
}

/*
  The Q_ASSERT macro calls this this function when the test fails.
*/
void qt_assert(const char *assertion, const char *file, int line)
{
    qFatal("ASSERT: \"%s\" in file %s, line %d", assertion, file, line);
}

/*
  The Q_ASSERT_X macro calls this this function when the test fails.
*/
void qt_assert_x(const char *where, const char *what, const char *file, int line)
{
    qFatal("ASSERT failure in %s: \"%s\", file %s, line %d", where, what, file, line);
}


/*
    Dijkstra's bisection algorithm to find the square root of an integer.
    Deliberately not exported as part of the Qt API, but used in both
    qsimplerichtext.cpp and qgfxraster_qws.cpp
*/
Q_CORE_EXPORT unsigned int qt_int_sqrt(unsigned int n)
{
    // n must be in the range 0...UINT_MAX/2-1
    if (n >= (UINT_MAX>>2)) {
        unsigned int r = 2 * qt_int_sqrt(n / 4);
        unsigned int r2 = r + 1;
        return (n >= r2 * r2) ? r2 : r;
    }
    uint h, p= 0, q= 1, r= n;
    while (q <= n)
        q <<= 2;
    while (q != 1) {
        q >>= 2;
        h= p + q;
        p >>= 1;
        if (r >= h) {
            p += q;
            r -= h;
        }
    }
    return p;
}

#if defined(qMemCopy)
#  undef qMemCopy
#endif
#if defined(qMemSet)
#  undef qMemSet
#endif

void *qMalloc(size_t size) { return ::malloc(size); }
void qFree(void *ptr) { ::free(ptr); }
void *qRealloc(void *ptr, size_t size) { return ::realloc(ptr, size); }
void *qMemCopy(void *dest, const void *src, size_t n) { return memcpy(dest, src, n); }
void *qMemSet(void *dest, int c, size_t n) { return memset(dest, c, n); }


static QtMsgHandler handler = 0;                // pointer to debug handler
static const int QT_BUFFER_LENGTH = 8192;       // internal buffer length

#ifdef Q_CC_MWERKS
#include <CoreServices/CoreServices.h>
extern bool qt_is_gui_used;
static void mac_default_handler(const char *msg)
{
    if (qt_is_gui_used) {
        Str255 pmsg;
        qt_mac_to_pascal_string(msg, pmsg);
        DebugStr(pmsg);
    } else {
        fprintf(stderr, msg);
    }
}
#endif // Q_CC_MWERKS


QString qt_error_string(int errorCode)
{
    const char *s = 0;
    QString ret;
    if (errorCode == -1) {
#if defined(Q_OS_WIN32)
        errorCode = GetLastError();
#else
        errorCode = errno;
#endif
    }
    switch (errorCode) {
    case 0:
        break;
    case EACCES:
        s = QT_TRANSLATE_NOOP("QIODevice", "Permission denied");
        break;
    case EMFILE:
        s = QT_TRANSLATE_NOOP("QIODevice", "Too many open files");
        break;
    case ENOENT:
        s = QT_TRANSLATE_NOOP("QIODevice", "No such file or directory");
        break;
    case ENOSPC:
        s = QT_TRANSLATE_NOOP("QIODevice", "No space left on device");
        break;
    default: {
#ifdef Q_OS_WIN
        QT_WA({
            unsigned short *string = 0;
            FormatMessage(FORMAT_MESSAGE_ALLOCATE_BUFFER|FORMAT_MESSAGE_FROM_SYSTEM,
                          NULL,
                          errorCode,
                          MAKELANGID(LANG_NEUTRAL, SUBLANG_DEFAULT),
                          (LPTSTR)&string,
                          0,
                          NULL);
            ret = QString::fromUtf16(string);
            LocalFree((HLOCAL)string);
        }, {
            char *string = 0;
            FormatMessageA(FORMAT_MESSAGE_ALLOCATE_BUFFER|FORMAT_MESSAGE_FROM_SYSTEM,
                           NULL,
                           errorCode,
                           MAKELANGID(LANG_NEUTRAL, SUBLANG_DEFAULT),
                           (LPSTR)&string,
                           0,
                           NULL);
            ret = QString::fromLocal8Bit(string);
            LocalFree((HLOCAL)string);
        });
#elif !defined(QT_NO_THREAD) && defined(_POSIX_THREAD_SAFE_FUNCTIONS) && _POSIX_VERSION >= 200112L
        QByteArray buf(1024, '\0');
        strerror_r(errorCode, buf.data(), buf.size());
        ret = QString::fromLocal8Bit(buf.constData());
#else
        ret = QString::fromLocal8Bit(strerror(errorCode));
#endif
	break; }
    }
    if (s)
        // ######## this breaks moc build currently
//         ret = QCoreApplication::translate("QIODevice", s);
        ret = QString::fromLatin1(s);
    return ret.trimmed();
}

/*!
    \fn QtMsgHandler qInstallMsgHandler(QtMsgHandler handler)
    \relates <QtGlobal>

    Installs a Qt message \a handler whis has been defined
    previously. Returns a pointer to the message \a handler.

    The message handler is a function that prints out debug messages,
    warnings, critical and fatal error messages. The Qt library (debug
    version) contains hundreds of warning messages that are printed
    when internal errors (usually invalid function arguments)
    occur. If you implement your own message handler, you get total
    control of these messages.

    The default message handler prints the message to the standard
    output under X11 or to the debugger under Windows. If it is a
    fatal message, the application aborts immediately.

    Only one message handler can be defined, since this is usually
    done on an application-wide basis to control debug output.

    To restore the message handler, call \c qInstallMsgHandler(0).

    Example:

    \code
        #include <qapplication.h>
        #include <stdio.h>
        #include <stdlib.h>

        void myMessageOutput(QtMsgType type, const char *msg)
        {
            switch (type) {
            case QtDebugMsg:
                fprintf(stderr, "Debug: %s\n", msg);
                break;
            case QtWarningMsg:
                fprintf(stderr, "Warning: %s\n", msg);
                break;
            case QtCriticalMsg:
                fprintf(stderr, "Critical: %s\n", msg);
                break;
            case QtFatalMsg:
                fprintf(stderr, "Fatal: %s\n", msg);
                abort();
            }
        }

        int main(int argc, char **argv)
        {
            qInstallMsgHandler(myMessageOutput);
            QApplication app(argc, argv);
            ...
            return app.exec();
        }
    \endcode

    \sa qDebug(), qWarning(), qCritical(), qFatal(), QtMsgType,
    {Debugging Techniques}
*/
QtMsgHandler qInstallMsgHandler(QtMsgHandler h)
{
    QtMsgHandler old = handler;
    handler = h;
    return old;
}


void qt_message_output(QtMsgType msgType, const char *buf)
{
    if (handler) {
        (*handler)(msgType, buf);
    } else {
#if defined(Q_CC_MWERKS)
        mac_default_handler(buf);
#elif defined(Q_OS_TEMP)
        QString fstr(buf);
        OutputDebugString((fstr + "\n").utf16());
#else
        fprintf(stderr, "%s\n", buf);
        fflush(stderr);
#endif
    }

    if (msgType == QtFatalMsg
        || (msgType == QtWarningMsg
            && (!qgetenv("QT_FATAL_WARNINGS").isNull())) ) {

#if defined(Q_CC_MSVC) && defined(QT_DEBUG) && defined(_DEBUG) && defined(_CRT_ERROR)
        // get the current report mode
        int reportMode = _CrtSetReportMode(_CRT_ERROR, _CRTDBG_MODE_WNDW);
        _CrtSetReportMode(_CRT_ERROR, reportMode);
        int ret = _CrtDbgReport(_CRT_ERROR, __FILE__, __LINE__, QT_VERSION_STR, buf);
        if (ret == 0  && reportMode & _CRTDBG_MODE_WNDW)
            return; // ignore
        else if (ret == 1)
            _CrtDbgBreak();
#endif

#if defined(Q_OS_UNIX) && defined(QT_DEBUG)
        abort(); // trap; generates core dump
#else
        exit(1); // goodbye cruel world
#endif
    }
}

#undef qDebug
/*!
    \relates <QtGlobal>

    Calls the message handler with the debug message \a msg. If no
    message handler has been installed, the message is printed to
    stderr. Under Windows, the message is sent to the debugger. This
    function does nothing if \c QT_NO_DEBUG_OUTPUT was defined during
    compilation.

    If you pass the function a format string and a list of arguments,
    it works in similar way to the C printf() function.

    Example:

    \code
        qDebug("Items in list: %d", myList.size());
    \endcode

    If you include \c <QtDebug>, a more convenient syntax is also
    available:

    \code
        qDebug() << "Brush:" << myQBrush << "Other value:" << i;
    \endcode

    This syntax automatically puts a single space between each item,
    and outputs a newline at the end. It supports many C++ and Qt
    types.

    \warning The internal buffer is limited to 8192 bytes, including
    the '\0'-terminator.

    \warning Passing (const char *)0 as argument to qDebug might lead
    to crashes on certain platforms due to the platform's printf() implementation.

    \sa qWarning(), qCritical(), qFatal(), qInstallMsgHandler(),
        {Debugging Techniques}
*/
void qDebug(const char *msg, ...)
{
    char buf[QT_BUFFER_LENGTH];
    buf[QT_BUFFER_LENGTH - 1] = '\0';
    va_list ap;
    va_start(ap, msg);                        // use variable arg list
    qvsnprintf(buf, QT_BUFFER_LENGTH - 1, msg, ap);
    va_end(ap);

    qt_message_output(QtDebugMsg, buf);
}

#undef qWarning
/*!
    \relates <QtGlobal>

    Calls the message handler with the warning message \a msg. If no
    message handler has been installed, the message is printed to
    stderr. Under Windows, the message is sent to the debugger. This
    function does nothing if \c QT_NO_WARNING_OUTPUT was defined
    during compilation; it exits if the environment variable \c
    QT_FATAL_WARNINGS is defined.

    This function takes a format string and a list of arguments,
    similar to the C printf() function.

    Example:
    \code
        void f(int c)
        {
            if (c > 200)
                qWarning("f: bad argument, c == %d", c);
        }
    \endcode

    \warning The internal buffer is limited to 8192 bytes, including
    the '\0'-terminator.

    \warning Passing (const char *)0 as argument to qWarning might lead
    to crashes on certain platforms due to the platforms printf implementation.

    \sa qDebug(), qCritical(), qFatal(), qInstallMsgHandler(),
        {Debugging Techniques}
*/
void qWarning(const char *msg, ...)
{
    char buf[QT_BUFFER_LENGTH];
    buf[QT_BUFFER_LENGTH - 1] = '\0';
    va_list ap;
    va_start(ap, msg); // use variable arg list
    qvsnprintf(buf, QT_BUFFER_LENGTH - 1, msg, ap);
    va_end(ap);

    qt_message_output(QtWarningMsg, buf);
}

/*!
    \relates <QtGlobal>

    Calls the message handler with the critical message \a msg. If no
    message handler has been installed, the message is printed to
    stderr. Under Windows, the message is sent to the debugger.

    This function takes a format string and a list of arguments, similar
    to the C printf() function.

    Example:
    \code
        void load(const QString &fileName)
        {
            QFile file(fileName);
            if (!file.exists())