path: root/src/libs/extensionsystem/pluginspec.cpp

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#include "pluginspec.h"
#include "pluginspec.h"
#include "pluginspec_p.h"
#include "iplugin.h"
#include "iplugin_p.h"
#include "pluginmanager.h"

#include <QtCore/QFile>
#include <QtCore/QFileInfo>
#include <QtCore/QXmlStreamReader>
#include <QtCore/QRegExp>
#include <QtCore/QPluginLoader>
#include <QtCore/QCoreApplication>
#include <QtDebug>

/*!
    \class ExtensionSystem::PluginDependency
    \brief Struct that contains the name and required compatible version number of a plugin's dependency.

    This reflects the data of a dependency tag in the plugin's xml description file.
    The name and version are used to resolve the dependency, i.e. a plugin with the given name and
    plugin \c {compatibility version <= dependency version <= plugin version} is searched for.

    See also ExtensionSystem::IPlugin for more information about plugin dependencies and
    version matching.
*/

/*!
    \variable ExtensionSystem::PluginDependency::name
    String identifier of the plugin.
*/

/*!
    \variable ExtensionSystem::PluginDependency::version
    Version string that a plugin must match to fill this dependency.
*/

/*!
    \class ExtensionSystem::PluginSpec
    \brief Contains the information of the plugins xml description file and
    information about the plugin's current state.

    The plugin spec is also filled with more information as the plugin
    goes through it's loading process (see PluginSpec::State).
    If an error occurs, the plugin spec is the place to look for the
    error details.
*/

/*!
    \enum ExtensionSystem::PluginSpec::State

    The plugin goes through several steps while being loaded.
    The state gives a hint on what went wrong in case of an error.

    \value  Invalid
            Starting point: Even the xml description file was not read.
    \value  Read
            The xml description file has been successfully read, and it's
            information is available via the PluginSpec.
    \value  Resolved
            The dependencies given in the description file have been
            successfully found, and are available via the dependencySpecs() method.
    \value  Loaded
            The plugin's library is loaded and the plugin instance created
            (available through plugin()).
    \value  Initialized
            The plugin instance's IPlugin::initialize() method has been called
            and returned a success value.
    \value  Running
            The plugin's dependencies are successfully initialized and
            extensionsInitialized has been called. The loading process is
            complete.
    \value Stopped
            The plugin has been shut down, i.e. the plugin's IPlugin::shutdown() method has been called.
    \value Deleted
            The plugin instance has been deleted.
*/
using namespace ExtensionSystem;
using namespace ExtensionSystem::Internal;

/*!
    \fn bool PluginDependency::operator==(const PluginDependency &other)
    \internal
*/
bool PluginDependency::operator==(const PluginDependency &other)
{
    return name == other.name && version == other.version;
}

/*!
    \fn PluginSpec::PluginSpec()
    \internal
*/
PluginSpec::PluginSpec()
    : d(new PluginSpecPrivate(this))
{
}

/*!
    \fn PluginSpec::~PluginSpec()
    \internal
*/
PluginSpec::~PluginSpec()
{
    delete d;
    d = 0;
}

/*!
    \fn QString PluginSpec::name() const
    The plugin name. This is valid after the PluginSpec::Read state is reached.
*/
QString PluginSpec::name() const
{
    return d->name;
}

/*!
    \fn QString PluginSpec::version() const
    The plugin version. This is valid after the PluginSpec::Read state is reached.
*/
QString PluginSpec::version() const
{
    return d->version;
}

/*!
    \fn QString PluginSpec::compatVersion() const
    The plugin compatibility version. This is valid after the PluginSpec::Read state is reached.
*/
QString PluginSpec::compatVersion() const
{
    return d->compatVersion;
}

/*!
    \fn QString PluginSpec::vendor() const
    The plugin vendor. This is valid after the PluginSpec::Read state is reached.
*/
QString PluginSpec::vendor() const
{
    return d->vendor;
}

/*!
    \fn QString PluginSpec::copyright() const
    The plugin copyright. This is valid after the PluginSpec::Read state is reached.
*/
QString PluginSpec::copyright() const
{
    return d->copyright;
}

/*!
    \fn QString PluginSpec::license() const
    The plugin license. This is valid after the PluginSpec::Read state is reached.
*/
QString PluginSpec::license() const
{
    return d->license;
}

/*!
    \fn QString PluginSpec::description() const
    The plugin description. This is valid after the PluginSpec::Read state is reached.
*/
QString PluginSpec::description() const
{
    return d->description;
}

/*!
    \fn QString PluginSpec::url() const
    The plugin url where you can find more information about the plugin. This is valid after the PluginSpec::Read state is reached.
*/
QString PluginSpec::url() const
{
    return d->url;
}

/*!
    \fn QList<PluginDependency> PluginSpec::dependencies() const
    The plugin dependencies. This is valid after the PluginSpec::Read state is reached.
*/
QList<PluginDependency> PluginSpec::dependencies() const
{
    return d->dependencies;
}

/*!
    \fn PluginSpec::PluginArgumentDescriptions PluginSpec::argumentDescriptions() const
    Returns a list of descriptions of command line arguments the plugin processes.
*/

PluginSpec::PluginArgumentDescriptions PluginSpec::argumentDescriptions() const
{
    return d->argumentDescriptions;
}

/*!
    \fn QString PluginSpec::location() const
    The absolute path to the directory containing the plugin xml description file
    this PluginSpec corresponds to.
*/
QString PluginSpec::location() const
{
    return d->location;
}

/*!
    \fn QString PluginSpec::filePath() const
    The absolute path to the plugin xml description file (including the file name)
    this PluginSpec corresponds to.
*/
QString PluginSpec::filePath() const
{
    return d->filePath;
}

/*!
    \fn QStringList PluginSpec::arguments() const
    Command line arguments specific to that plugin. Set at startup
*/

QStringList PluginSpec::arguments() const
{
    return d->arguments;
}

/*!
    \fn void PluginSpec::setArguments(const QStringList &arguments)
    Set the command line arguments specific to that plugin to \a arguments.
*/

void PluginSpec::setArguments(const QStringList &arguments)
{
    d->arguments = arguments;
}

/*!
    \fn PluginSpec::addArgument(const QString &argument)
    Adds \a argument to the command line arguments specific to that plugin.
*/

void PluginSpec::addArgument(const QString &argument)
{
    d->arguments.push_back(argument);
}


/*!
    \fn PluginSpec::State PluginSpec::state() const
    The state in which the plugin currently is.
    See the description of the PluginSpec::State enum for details.
*/
PluginSpec::State PluginSpec::state() const
{
    return d->state;
}

/*!
    \fn bool PluginSpec::hasError() const
    Returns whether an error occurred while reading/starting the plugin.
*/
bool PluginSpec::hasError() const
{
    return d->hasError;
}

/*!
    \fn QString PluginSpec::errorString() const
    Detailed, possibly multi-line, error description in case of an error.
*/
QString PluginSpec::errorString() const
{
    return d->errorString;
}

/*!
    \fn bool PluginSpec::provides(const QString &pluginName, const QString &version) const
    Returns if this plugin can be used to fill in a dependency of the given
    \a pluginName and \a version.

        \sa PluginSpec::dependencies()
*/
bool PluginSpec::provides(const QString &pluginName, const QString &version) const
{
    return d->provides(pluginName, version);
}

/*!
    \fn IPlugin *PluginSpec::plugin() const
    The corresponding IPlugin instance, if the plugin library has already been successfully loaded,
    i.e. the PluginSpec::Loaded state is reached.
*/
IPlugin *PluginSpec::plugin() const
{
    return d->plugin;
}

/*!
    \fn QList<PluginSpec *> PluginSpec::dependencySpecs() const
    Returns the list of dependencies, already resolved to existing plugin specs.
    Valid if PluginSpec::Resolved state is reached.

    \sa PluginSpec::dependencies()
*/
QList<PluginSpec *> PluginSpec::dependencySpecs() const
{
    return d->dependencySpecs;
}

//==========PluginSpecPrivate==================

namespace {
    const char * const PLUGIN = "plugin";
    const char * const PLUGIN_NAME = "name";
    const char * const PLUGIN_VERSION = "version";
    const char * const PLUGIN_COMPATVERSION = "compatVersion";
    const char * const VENDOR = "vendor";
    const char * const COPYRIGHT = "copyright";
    const char * const LICENSE = "license";
    const char * const DESCRIPTION = "description";
    const char * const URL = "url";
    const char * const DEPENDENCYLIST = "dependencyList";
    const char * const DEPENDENCY = "dependency";
    const char * const DEPENDENCY_NAME = "name";
    const char * const DEPENDENCY_VERSION = "version";
    const char * const ARGUMENTLIST = "argumentList";
    const char * const ARGUMENT = "argument";
    const char * const ARGUMENT_NAME = "name";
    const char * const ARGUMENT_PARAMETER = "parameter";
}
/*!
    \fn PluginSpecPrivate::PluginSpecPrivate(PluginSpec *spec)
    \internal
*/
PluginSpecPrivate::PluginSpecPrivate(PluginSpec *spec)
    : plugin(0),
    state(PluginSpec::Invalid),
    hasError(false),
    q(spec)
{
}

/*!
    \fn bool PluginSpecPrivate::read(const QString &fileName)
    \internal
*/
bool PluginSpecPrivate::read(const QString &fileName)
{
    name
        = version
        = compatVersion
        = vendor
        = copyright
        = license
        = description
        = url
        = location
        = "";
    state = PluginSpec::Invalid;
    hasError = false;
    errorString = "";
    dependencies.clear();
    QFile file(fileName);
    if (!file.exists())
        return reportError(tr("File does not exist: %1").arg(file.fileName()));
    if (!file.open(QIODevice::ReadOnly))
        return reportError(tr("Could not open file for read: %1").arg(file.fileName()));
    QFileInfo fileInfo(file);
    location = fileInfo.absolutePath();
    filePath = fileInfo.absoluteFilePath();
    QXmlStreamReader reader(&file);
    while (!reader.atEnd()) {
        reader.readNext();
        switch (reader.tokenType()) {
        case QXmlStreamReader::StartElement:
            readPluginSpec(reader);
            break;
        default:
            break;
        }
    }
    if (reader.hasError())
        return reportError(tr("Error parsing file %1: %2, at line %3, column %4")
                .arg(file.fileName())
                .arg(reader.errorString())
                .arg(reader.lineNumber())
                .arg(reader.columnNumber()));
    state = PluginSpec::Read;
    return true;
}

/*!
    \fn bool PluginSpecPrivate::reportError(const QString &err)
    \internal
*/
bool PluginSpecPrivate::reportError(const QString &err)
{
    errorString = err;
    hasError = true;
    return false;
}

static inline QString msgAttributeMissing(const char *elt, const char *attribute)
{
    return QCoreApplication::translate("PluginSpec", "'%1' misses attribute '%2'").arg(QLatin1String(elt), QLatin1String(attribute));
}

static inline QString msgInvalidFormat(const char *content)
{
    return QCoreApplication::translate("PluginSpec", "'%1' has invalid format").arg(content);
}

static inline QString msgInvalidElement(const QString &name)
{
    return QCoreApplication::translate("PluginSpec", "Invalid element '%1'").arg(name);
}

static inline QString msgUnexpectedClosing(const QString &name)
{
    return QCoreApplication::translate("PluginSpec", "Unexpected closing element '%1'").arg(name);
}

static inline QString msgUnexpectedToken()
{
    return QCoreApplication::translate("PluginSpec", "Unexpected token");
}

/*!
    \fn void PluginSpecPrivate::readPluginSpec(QXmlStreamReader &reader)
    \internal
*/
void PluginSpecPrivate::readPluginSpec(QXmlStreamReader &reader)
{
    QString element = reader.name().toString();
    if (element != QString(PLUGIN)) {
        reader.raiseError(QCoreApplication::translate("PluginSpec", "Expected element '%1' as top level element").arg(PLUGIN));
        return;
    }
    name = reader.attributes().value(PLUGIN_NAME).toString();
    if (name.isEmpty()) {
        reader.raiseError(msgAttributeMissing(PLUGIN, PLUGIN_NAME));
        return;
    }
    version = reader.attributes().value(PLUGIN_VERSION).toString();
    if (version.isEmpty()) {
        reader.raiseError(msgAttributeMissing(PLUGIN, PLUGIN_VERSION));
        return;
    }
    if (!isValidVersion(version)) {
        reader.raiseError(msgInvalidFormat(PLUGIN_VERSION));
        return;
    }
    compatVersion = reader.attributes().value(PLUGIN_COMPATVERSION).toString();
    if (!compatVersion.isEmpty() && !isValidVersion(compatVersion)) {
        reader.raiseError(msgInvalidFormat(PLUGIN_COMPATVERSION));
        return;
    } else if (compatVersion.isEmpty()) {
        compatVersion = version;
    }
    while (!reader.atEnd()) {
        reader.readNext();
        switch (reader.tokenType()) {
        case QXmlStreamReader::StartElement:
            element = reader.name().toString();
            if (element == VENDOR)
                vendor = reader.readElementText().trimmed();
            else if (element == COPYRIGHT)
                copyright = reader.readElementText().trimmed();
            else if (element == LICENSE)
                license = reader.readElementText().trimmed();
            else if (element == DESCRIPTION)
                description = reader.readElementText().trimmed();
            else if (element == URL)
                url = reader.readElementText().trimmed();
            else if (element == DEPENDENCYLIST)
                readDependencies(reader);
            else if (element == ARGUMENTLIST)
                readArgumentDescriptions(reader);
            else
                reader.raiseError(msgInvalidElement(name));
            break;
        case QXmlStreamReader::EndDocument:
        case QXmlStreamReader::Comment:
        case QXmlStreamReader::EndElement:
        case QXmlStreamReader::Characters:
            break;
        default:
            reader.raiseError(msgUnexpectedToken());
            break;
        }
    }
}

/*!
    \fn void PluginSpecPrivate::readArgumentDescriptions(QXmlStreamReader &reader)
    \internal
*/

void PluginSpecPrivate::readArgumentDescriptions(QXmlStreamReader &reader)
{
    QString element;
    while (!reader.atEnd()) {
        reader.readNext();
        switch (reader.tokenType()) {
        case QXmlStreamReader::StartElement:
            element = reader.name().toString();
            if (element == ARGUMENT) {
                readArgumentDescription(reader);
            } else {
                reader.raiseError(msgInvalidElement(name));
            }
            break;
        case QXmlStreamReader::Comment:
        case QXmlStreamReader::Characters:
            break;
        case QXmlStreamReader::EndElement:
            element = reader.name().toString();
            if (element == ARGUMENTLIST)
                return;
            reader.raiseError(msgUnexpectedClosing(element));
            break;
        default:
            reader.raiseError(msgUnexpectedToken());
            break;
        }
    }
}

/*!
    \fn void PluginSpecPrivate::readArgumentDescription(QXmlStreamReader &reader)
    \internal
*/
void PluginSpecPrivate::readArgumentDescription(QXmlStreamReader &reader)
{
    PluginArgumentDescription arg;
    arg.name = reader.attributes().value(ARGUMENT_NAME).toString();
    if (arg.name.isEmpty()) {
        reader.raiseError(msgAttributeMissing(ARGUMENT, ARGUMENT_NAME));
        return;
    }
    arg.parameter = reader.attributes().value(ARGUMENT_PARAMETER).toString();
    arg.description = reader.readElementText();
    if (reader.tokenType() != QXmlStreamReader::EndElement)
        reader.raiseError(msgUnexpectedToken());
    argumentDescriptions.push_back(arg);
}

/*!
    \fn void PluginSpecPrivate::readDependencies(QXmlStreamReader &reader)
    \internal
*/
void PluginSpecPrivate::readDependencies(QXmlStreamReader &reader)
{
    QString element;
    while (!reader.atEnd()) {
        reader.readNext();
        switch (reader.tokenType()) {
        case QXmlStreamReader::StartElement:
            element = reader.name().toString();
            if (element == DEPENDENCY) {
                readDependencyEntry(reader);
            } else {
                reader.raiseError(msgInvalidElement(name));
            }
            break;
        case QXmlStreamReader::Comment:
        case QXmlStreamReader::Characters:
            break;
        case QXmlStreamReader::EndElement:
            element = reader.name().toString();
            if (element == DEPENDENCYLIST)
                return;
            reader.raiseError(msgUnexpectedClosing(element));
            break;
        default:
            reader.raiseError(msgUnexpectedToken());
            break;
        }
    }
}

/*!
    \fn void PluginSpecPrivate::readDependencyEntry(QXmlStreamReader &reader)
    \internal
*/
void PluginSpecPrivate::readDependencyEntry(QXmlStreamReader &reader)
{
    PluginDependency dep;
    dep.name = reader.attributes().value(DEPENDENCY_NAME).toString();
    if (dep.name.isEmpty()) {
        reader.raiseError(msgAttributeMissing(DEPENDENCY, DEPENDENCY_NAME));
        return;
    }
    dep.version = reader.attributes().value(DEPENDENCY_VERSION).toString();
    if (!dep.version.isEmpty() && !isValidVersion(dep.version)) {
        reader.raiseError(msgInvalidFormat(DEPENDENCY_VERSION));
        return;
    }
    dependencies.append(dep);
    reader.readNext();
    if (reader.tokenType() != QXmlStreamReader::EndElement)
        reader.raiseError(msgUnexpectedToken());
}

/*!
    \fn bool PluginSpecPrivate::provides(const QString &pluginName, const QString &pluginVersion) const
    \internal
*/
bool PluginSpecPrivate::provides(const QString &pluginName, const QString &pluginVersion) const
{
    if (QString::compare(pluginName, name, Qt::CaseInsensitive) != 0)
        return false;
    return (versionCompare(version, pluginVersion) >= 0) && (versionCompare(compatVersion, pluginVersion) <= 0);
}

/*!
    \fn QRegExp &PluginSpecPrivate::versionRegExp()
    \internal
*/
QRegExp &PluginSpecPrivate::versionRegExp()
{
    static QRegExp reg("([0-9]+)(?:[.]([0-9]+))?(?:[.]([0-9]+))?(?:_([0-9]+))?");
    return reg;
}
/*!
    \fn bool PluginSpecPrivate::isValidVersion(const QString &version)
    \internal
*/
bool PluginSpecPrivate::isValidVersion(const QString &version)
{
    return versionRegExp().exactMatch(version);
}

/*!
    \fn int PluginSpecPrivate::versionCompare(const QString &version1, const QString &version2)
    \internal
*/
int PluginSpecPrivate::versionCompare(const QString &version1, const QString &version2)
{
    QRegExp reg1 = versionRegExp();
    QRegExp reg2 = versionRegExp();
    if (!reg1.exactMatch(version1))
        return 0;
    if (!reg2.exactMatch(version2))
        return 0;
    int number1;
    int number2;
    for (int i = 0; i < 4; ++i) {
        number1 = reg1.cap(i+1).toInt();
        number2 = reg2.cap(i+1).toInt();
        if (number1 < number2)
            return -1;
        if (number1 > number2)
            return 1;
    }
    return 0;
}

/*!
    \fn bool PluginSpecPrivate::resolveDependencies(const QList<PluginSpec *> &specs)
    \internal
*/
bool PluginSpecPrivate::resolveDependencies(const QList<PluginSpec *> &specs)
{
    if (hasError)
        return false;
    if (state == PluginSpec::Resolved)
        state = PluginSpec::Read; // Go back, so we just re-resolve the dependencies.
    if (state != PluginSpec::Read) {
        errorString = QCoreApplication::translate("PluginSpec", "Resolving dependencies failed because state != Read");
        hasError = true;
        return false;
    }
    QList<PluginSpec *> resolvedDependencies;
    foreach (const PluginDependency &dependency, dependencies) {
        PluginSpec *found = 0;
        foreach (PluginSpec *spec, specs) {
            if (spec->provides(dependency.name, dependency.version)) {
                found = spec;
                break;
            }
        }
        if (!found) {
            hasError = true;
            if (!errorString.isEmpty())
                errorString.append("\n");
            errorString.append(QCoreApplication::translate("PluginSpec", "Could not resolve dependency '%1(%2)'")
                .arg(dependency.name).arg(dependency.version));
            continue;
        }
        resolvedDependencies.append(found);
    }
    if (hasError)
        return false;
    dependencySpecs = resolvedDependencies;
    state = PluginSpec::Resolved;
    return true;
}

/*!
    \fn bool PluginSpecPrivate::loadLibrary()
    \internal
*/
bool PluginSpecPrivate::loadLibrary()
{
    if (hasError)
        return false;
    if (state != PluginSpec::Resolved) {
        if (state == PluginSpec::Loaded)
            return true;
        errorString = QCoreApplication::translate("PluginSpec", "Loading the library failed because state != Resolved");
        hasError = true;
        return false;
    }
#ifdef QT_NO_DEBUG

#ifdef Q_OS_WIN
    QString libName = QString("%1/%2.dll").arg(location).arg(name);
#elif defined(Q_OS_MAC)
    QString libName = QString("%1/lib%2.dylib").arg(location).arg(name);
#else
    QString libName = QString("%1/lib%2.so").arg(location).arg(name);
#endif

#else //Q_NO_DEBUG

#ifdef Q_OS_WIN
    QString libName = QString("%1/%2d.dll").arg(location).arg(name);
#elif defined(Q_OS_MAC)
    QString libName = QString("%1/lib%2_debug.dylib").arg(location).arg(name);
#else
    QString libName = QString("%1/lib%2.so").arg(location).arg(name);
#endif

#endif

    QPluginLoader loader(libName);
    if (!loader.load()) {
        hasError = true;
        errorString = loader.errorString();
        errorString.append(QCoreApplication::translate("PluginSpec", "\nLibrary base name: %1").arg(libName));
        return false;
    }
    IPlugin *pluginObject = qobject_cast<IPlugin*>(loader.instance());
    if (!pluginObject) {
        hasError = true;
        errorString = QCoreApplication::translate("PluginSpec", "Plugin is not valid (doesn't derive from IPlugin)");
        loader.unload();
        return false;
    }
    state = PluginSpec::Loaded;
    plugin = pluginObject;
    plugin->d->pluginSpec = q;
    return true;
}

/*!
    \fn bool PluginSpecPrivate::initializePlugin()
    \internal
*/
bool PluginSpecPrivate::initializePlugin()
{
    if (hasError)
        return false;
    if (state != PluginSpec::Loaded) {
        if (state == PluginSpec::Initialized)
            return true;
        errorString = QCoreApplication::translate("PluginSpec", "Initializing the plugin failed because state != Loaded");
        hasError = true;
        return false;
    }
    if (!plugin) {
        errorString = QCoreApplication::translate("PluginSpec", "Internal error: have no plugin instance to initialize");
        hasError = true;
        return false;
    }
    QString err;
    if (!plugin->initialize(arguments, &err)) {
        errorString = QCoreApplication::translate("PluginSpec", "Plugin initialization failed: %1").arg(err);
        hasError = true;
        return false;
    }
    state = PluginSpec::Initialized;
    return true;
}

/*!
    \fn bool PluginSpecPrivate::initializeExtensions()
    \internal
*/
bool PluginSpecPrivate::initializeExtensions()
{
    if (hasError)
        return false;
    if (state != PluginSpec::Initialized) {
        if (state == PluginSpec::Running)
            return true;
        errorString = QCoreApplication::translate("PluginSpec", "Cannot perform extensionsInitialized because state != Initialized");
        hasError = true;
        return false;
    }
    if (!plugin) {
        errorString = QCoreApplication::translate("PluginSpec", "Internal error: have no plugin instance to perform extensionsInitialized");
        hasError = true;
        return false;
    }
    plugin->extensionsInitialized();
    state = PluginSpec::Running;
    return true;
}

/*!
    \fn bool PluginSpecPrivate::stop()
    \internal
*/
void PluginSpecPrivate::stop()
{
    if (!plugin)
        return;
    plugin->shutdown();
    state = PluginSpec::Stopped;
}

/*!
    \fn bool PluginSpecPrivate::kill()
    \internal
*/
void PluginSpecPrivate::kill()
{
    if (!plugin)
        return;
    delete plugin;
    plugin = 0;
    state = PluginSpec::Deleted;
}