path: root/src/corelib/tools/qlocale_icu.cpp

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#include "qglobal.h"
#include "qlibrary.h"
#include "qdebug.h"

#include "unicode/uversion.h"
#include "unicode/ucol.h"

QT_BEGIN_NAMESPACE

typedef UCollator *(*Ptr_ucol_open)(const char *loc, UErrorCode *status);
typedef void (*Ptr_ucol_close)(UCollator *coll);
typedef UCollationResult (*Ptr_ucol_strcoll)(const UCollator *coll, const UChar *source, int32_t sourceLength, const UChar *target, int32_t targetLength);
typedef int32_t (*Ptr_u_strToCase)(UChar *dest, int32_t destCapacity, const UChar *src, int32_t srcLength, const char *locale, UErrorCode *pErrorCode);

static Ptr_ucol_open ptr_ucol_open = 0;
static Ptr_ucol_strcoll ptr_ucol_strcoll = 0;
static Ptr_ucol_close ptr_ucol_close = 0;
static Ptr_u_strToCase ptr_u_strToUpper = 0;
static Ptr_u_strToCase ptr_u_strToLower = 0;

enum LibLoadStatus
{
    ErrorLoading = -1,
    NotLoaded = 0,
    Loaded = 1
};

static LibLoadStatus status = NotLoaded;

static UCollator *icuCollator = 0;

namespace {
struct Libraries {
    QLibrary libicui18n;
    QLibrary libicuuc;
    ~Libraries()
    {
        if (icuCollator) {
            ptr_ucol_close(icuCollator);
            icuCollator = 0;
        }

        libicui18n.unload();
        libicuuc.unload();
    }
};
}
Q_GLOBAL_STATIC(Libraries, icuLibraries)

static bool loadIcuLibrary(QLibrary &lib, const QString &name)
{
#ifdef Q_OS_WIN
    // QLibrary on Windows does not use the version number, the libraries
    // are named "icuin<version>.dll", though.
    lib.setFileName(name);
#else
    // on Unix, we can use the version number
    lib.setFileNameAndVersion(name, QStringLiteral(U_ICU_VERSION_SHORT));
#endif

    // the ICU libraries appear to allocate global statics and not free them
    // set the PreventUnloadHint so that we can unload the QLibrary object and
    // delete it, but the libraries themselves remain in memory
    lib.setLoadHints(QLibrary::PreventUnloadHint);
    return lib.load();
}

// this function is NOT THREAD-SAFE!
bool qt_initIcu(const QString &localeString)
{
    if (status == ErrorLoading || !icuLibraries())
        return false;

    if (status == NotLoaded) {

        // resolve libicui18n
#ifdef Q_OS_WIN
        // QLibrary on Windows does not use the version number, the libraries
        // are named "icuin<version>.dll", though.
        // QStringLiteral should work here and will work when MSVC fully supports C++11
        // unfortunately, current versions have do not support proper string concatenation
        QString libicui18nName = QLatin1String("icuin" U_ICU_VERSION_SHORT);
        QString libicuucName = QLatin1String("icuuc" U_ICU_VERSION_SHORT);
#else
        QString libicui18nName = QStringLiteral("icui18n");
        QString libicuucName = QStringLiteral("icuuc");
#endif
        QLibrary &lib = icuLibraries()->libicui18n;
        if (!loadIcuLibrary(lib, libicui18nName)) {
            qWarning("Unable to load library '%s' version " U_ICU_VERSION_SHORT ": %s",
                     qPrintable(libicui18nName),
                     qPrintable(lib.errorString()));
            status = ErrorLoading;
            return false;
        }

        ptr_ucol_open = (Ptr_ucol_open)lib.resolve("ucol_open");
        ptr_ucol_close = (Ptr_ucol_close)lib.resolve("ucol_close");
        ptr_ucol_strcoll = (Ptr_ucol_strcoll)lib.resolve("ucol_strcoll");

        if (!ptr_ucol_open || !ptr_ucol_close || !ptr_ucol_strcoll) {
            // try again with decorated symbol names
            ptr_ucol_open = (Ptr_ucol_open)lib.resolve("ucol_open" QT_STRINGIFY(U_ICU_VERSION_SUFFIX));
            ptr_ucol_close = (Ptr_ucol_close)lib.resolve("ucol_close" QT_STRINGIFY(U_ICU_VERSION_SUFFIX));
            ptr_ucol_strcoll = (Ptr_ucol_strcoll)lib.resolve("ucol_strcoll" QT_STRINGIFY(U_ICU_VERSION_SUFFIX));
        }

        if (!ptr_ucol_open || !ptr_ucol_close || !ptr_ucol_strcoll) {
            ptr_ucol_open = 0;
            ptr_ucol_close = 0;
            ptr_ucol_strcoll = 0;

            qWarning("Unable to find symbols in '%s'.", qPrintable(libicui18nName));
            status = ErrorLoading;
            return false;
        }

        // resolve libicuuc
        QLibrary &ucLib = icuLibraries()->libicuuc;
        if (!loadIcuLibrary(ucLib, libicuucName)) {
            qWarning("Unable to load library '%s' version " U_ICU_VERSION_SHORT ": %s",
                     qPrintable(libicuucName),
                     qPrintable(ucLib.errorString()));
            status = ErrorLoading;
            return false;
        }

        ptr_u_strToUpper = (Ptr_u_strToCase)ucLib.resolve("u_strToUpper");
        ptr_u_strToLower = (Ptr_u_strToCase)ucLib.resolve("u_strToLower");

        if (!ptr_u_strToUpper || !ptr_u_strToLower) {
            ptr_u_strToUpper = (Ptr_u_strToCase)ucLib.resolve("u_strToUpper" QT_STRINGIFY(U_ICU_VERSION_SUFFIX));
            ptr_u_strToLower = (Ptr_u_strToCase)ucLib.resolve("u_strToLower" QT_STRINGIFY(U_ICU_VERSION_SUFFIX));
        }

        if (!ptr_u_strToUpper || !ptr_u_strToLower) {
            ptr_u_strToUpper = 0;
            ptr_u_strToLower = 0;

            qWarning("Unable to find symbols in '%s'", qPrintable(libicuucName));
            status = ErrorLoading;
            return false;
        }

        // success :)
        status = Loaded;
    }

    if (icuCollator) {
        ptr_ucol_close(icuCollator);
        icuCollator = 0;
    }

    UErrorCode icuStatus = U_ZERO_ERROR;
    icuCollator = ptr_ucol_open(localeString.toLatin1().constData(), &icuStatus);

    if (!icuCollator) {
        qWarning("Unable to open locale %s in ICU, error code %d", qPrintable(localeString), icuStatus);
        return false;
    }

    return true;
}

bool qt_ucol_strcoll(const QChar *source, int sourceLength, const QChar *target, int targetLength, int *result)
{
    Q_ASSERT(result);
    Q_ASSERT(source);
    Q_ASSERT(target);

    if (!icuCollator)
        return false;

    *result = ptr_ucol_strcoll(icuCollator, reinterpret_cast<const UChar *>(source), int32_t(sourceLength),
                               reinterpret_cast<const UChar *>(target), int32_t(targetLength));

    return true;
}

// caseFunc can either be u_strToUpper or u_strToLower
static bool qt_u_strToCase(const QString &str, QString *out, const QLocale &locale, Ptr_u_strToCase caseFunc)
{
    Q_ASSERT(out);

    if (!icuCollator)
        return false;

    QString result(str.size(), Qt::Uninitialized);

    UErrorCode status = U_ZERO_ERROR;

    int32_t size = caseFunc(reinterpret_cast<UChar *>(result.data()), result.size(),
            reinterpret_cast<const UChar *>(str.constData()), str.size(),
            locale.bcp47Name().toLatin1().constData(), &status);

    if (U_FAILURE(status))
        return false;

    if (size < result.size()) {
        result.resize(size);
    } else if (size > result.size()) {
        // the resulting string is larger than our source string
        result.resize(size);

        status = U_ZERO_ERROR;
        size = caseFunc(reinterpret_cast<UChar *>(result.data()), result.size(),
            reinterpret_cast<const UChar *>(str.constData()), str.size(),
            locale.bcp47Name().toLatin1().constData(), &status);

        if (U_FAILURE(status))
            return false;

        // if the sizes don't match now, we give up.
        if (size != result.size())
            return false;
    }

    *out = result;
    return true;
}

bool qt_u_strToUpper(const QString &str, QString *out, const QLocale &locale)
{
    return qt_u_strToCase(str, out, locale, ptr_u_strToUpper);
}

bool qt_u_strToLower(const QString &str, QString *out, const QLocale &locale)
{
    return qt_u_strToCase(str, out, locale, ptr_u_strToLower);
}

QT_END_NAMESPACE