add/unify i/o error handling

lots of use of Utils::FileSaver and Utils::FileReader

Task-number: QTCREATORBUG-1619

src/libs/extensionsystem/pluginspec.cpp

@@ -489,10 +489,9 @@ bool PluginSpecPrivate::read(const QString &fileName)
     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()));
+        return reportError(tr("Could not open file %1 for read: %2")
+                           .arg(QDir::toNativeSeparators(file.fileName()), file.errorString()));
     QFileInfo fileInfo(file);
     location = fileInfo.absolutePath();
     filePath = fileInfo.absoluteFilePath();

src/libs/utils/ssh/sshconnection.cpp

@@ -41,6 +41,7 @@
 #include "sshkeyexchange_p.h"
 
 #include <utils/qtcassert.h>
+#include <utils/fileutils.h>
 
 #include <botan/exceptn.h>
 #include <botan/init.h>
@@ -410,18 +411,12 @@ void SshConnectionPrivate::handleServiceAcceptPacket()
         m_sendFacility.sendUserAuthByPwdRequestPacket(m_connParams.userName.toUtf8(),
             SshCapabilities::SshConnectionService, m_connParams.password.toUtf8());
     } else {
-        QFile privKeyFile(m_connParams.privateKeyFile);
-        bool couldOpen = privKeyFile.open(QIODevice::ReadOnly);
-        QByteArray contents;
-        if (couldOpen)
-            contents = privKeyFile.readAll();
-        if (!couldOpen || privKeyFile.error() != QFile::NoError) {
+        Utils::FileReader reader;
+        if (!reader.fetch(m_connParams.privateKeyFile))
             throw SshClientException(SshKeyFileError,
-                tr("Could not read private key file: %1")
-                .arg(privKeyFile.errorString()));
-        }
+                tr("Private key error: %1").arg(reader.errorString()));
 
-        m_sendFacility.createAuthenticationKey(contents);
+        m_sendFacility.createAuthenticationKey(reader.data());
         m_sendFacility.sendUserAuthByKeyRequestPacket(m_connParams.userName.toUtf8(),
             SshCapabilities::SshConnectionService);
     }

src/plugins/coreplugin/actionmanager/commandsfile.cpp

@@ -39,6 +39,8 @@
 
 #include <utils/qtcassert.h>
 
+#include <utils/fileutils.h>
+
 #include <QtCore/QFile>
 #include <QtCore/QXmlStreamAttributes>
 #include <QtCore/QXmlStreamWriter>
@@ -134,37 +136,37 @@ bool CommandsFile::exportCommands(const QList<ShortcutItem *> &items)
 {
     const UniqueIDManager *idmanager = UniqueIDManager::instance();
 
-    QFile file(m_filename);
-    if (!file.open(QIODevice::WriteOnly|QIODevice::Text))
-        return false;
-
-    const Context ctx;
-    QXmlStreamWriter w(&file);
-    w.setAutoFormatting(true);
-    w.setAutoFormattingIndent(1); // Historical, used to be QDom.
-    w.writeStartDocument();
-    w.writeDTD(QLatin1String("<!DOCTYPE KeyboardMappingScheme>"));
-    w.writeComment(QString::fromAscii(" Written by Qt Creator %1, %2. ").
-                   arg(QLatin1String(Core::Constants::IDE_VERSION_LONG),
-                       QDateTime::currentDateTime().toString(Qt::ISODate)));
-    w.writeStartElement(ctx.mappingElement);
-    foreach (const ShortcutItem *item, items) {
-        const QString id = idmanager->stringForUniqueIdentifier(item->m_cmd->id());
-        if (item->m_key.isEmpty()) {
-            w.writeEmptyElement(ctx.shortCutElement);
-            w.writeAttribute(ctx.idAttribute, id);
-        } else {
-            w.writeStartElement(ctx.shortCutElement);
-            w.writeAttribute(ctx.idAttribute, id);
-            w.writeEmptyElement(ctx.keyElement);
-            w.writeAttribute(ctx.valueAttribute, item->m_key.toString());
-            w.writeEndElement(); // Shortcut
+    Utils::FileSaver saver(m_filename, QIODevice::Text);
+    if (!saver.hasError()) {
+        const Context ctx;
+        QXmlStreamWriter w(saver.file());
+        w.setAutoFormatting(true);
+        w.setAutoFormattingIndent(1); // Historical, used to be QDom.
+        w.writeStartDocument();
+        w.writeDTD(QLatin1String("<!DOCTYPE KeyboardMappingScheme>"));
+        w.writeComment(QString::fromAscii(" Written by Qt Creator %1, %2. ").
+                       arg(QLatin1String(Core::Constants::IDE_VERSION_LONG),
+                           QDateTime::currentDateTime().toString(Qt::ISODate)));
+        w.writeStartElement(ctx.mappingElement);
+        foreach (const ShortcutItem *item, items) {
+            const QString id = idmanager->stringForUniqueIdentifier(item->m_cmd->id());
+            if (item->m_key.isEmpty()) {
+                w.writeEmptyElement(ctx.shortCutElement);
+                w.writeAttribute(ctx.idAttribute, id);
+            } else {
+                w.writeStartElement(ctx.shortCutElement);
+                w.writeAttribute(ctx.idAttribute, id);
+                w.writeEmptyElement(ctx.keyElement);
+                w.writeAttribute(ctx.valueAttribute, item->m_key.toString());
+                w.writeEndElement(); // Shortcut
+            }
         }
+        w.writeEndElement();
+        w.writeEndDocument();
+
+        saver.setResult(&w);
     }
-    w.writeEndElement();
-    w.writeEndDocument();
-    file.close();
-    return true;
+    return saver.finalize();
 }
 
 } // namespace Internal

src/plugins/coreplugin/basefilewizard.cpp

@@ -42,6 +42,7 @@
 #include <utils/filewizarddialog.h>
 #include <utils/qtcassert.h>
 #include <utils/stringutils.h>
+#include <utils/fileutils.h>
 
 #include <QtCore/QDir>
 #include <QtCore/QFile>
@@ -179,23 +180,15 @@ bool GeneratedFile::write(QString *errorMessage) const
             return false;
         }
     }
-    // Write out
-    QFile file(m_d->path);
 
+    // Write out
     QIODevice::OpenMode flags = QIODevice::WriteOnly|QIODevice::Truncate;
     if (!isBinary())
         flags |= QIODevice::Text;
 
-    if (!file.open(flags)) {
-        *errorMessage = BaseFileWizard::tr("Unable to open %1 for writing: %2").arg(m_d->path, file.errorString());
-        return false;
-    }
-    if (file.write(m_d->contents) == -1) {
-        *errorMessage =  BaseFileWizard::tr("Error while writing to %1: %2").arg(m_d->path, file.errorString());
-        return false;
-    }
-    file.close();
-    return true;
+    Utils::FileSaver saver(m_d->path, flags);
+    saver.write(m_d->contents);
+    return saver.finalize(errorMessage);
 }
 
 GeneratedFile::Attributes GeneratedFile::attributes() const

src/plugins/coreplugin/externaltool.cpp

@@ -43,6 +43,7 @@
 #include <utils/qtcassert.h>
 #include <utils/stringutils.h>
 #include <utils/environment.h>
+#include <utils/fileutils.h>
 
 #include <QtCore/QXmlStreamReader>
 #include <QtCore/QXmlStreamWriter>
@@ -432,21 +433,15 @@ ExternalTool * ExternalTool::createFromXml(const QByteArray &xml, QString *error
 
 ExternalTool * ExternalTool::createFromFile(const QString &fileName, QString *errorMessage, const QString &locale)
 {
-    QFileInfo info(fileName);
-    QFile file(info.absoluteFilePath());
-    if (!file.open(QIODevice::ReadOnly)) {
-        if (errorMessage)
-            *errorMessage = tr("Could not open tool specification %1 for reading: %2").
-                            arg(fileName, file.errorString());
+    QString absFileName = QFileInfo(fileName).absoluteFilePath();
+    Utils::FileReader reader;
+    if (!reader.fetch(absFileName, errorMessage))
         return 0;
-    }
-    const QByteArray &bytes = file.readAll();
-    file.close();
-    ExternalTool *tool = ExternalTool::createFromXml(bytes, errorMessage, locale);
+    ExternalTool *tool = ExternalTool::createFromXml(reader.data(), errorMessage, locale);
     if (!tool) {
         return 0;
     }
-    tool->m_fileName = file.fileName();
+    tool->m_fileName = absFileName;
     return tool;
 }
 
@@ -467,43 +462,40 @@ bool ExternalTool::save(QString *errorMessage) const
 {
     if (m_fileName.isEmpty())
         return false;
-    QFile file(m_fileName);
-    if (!file.open(QIODevice::WriteOnly)) {
-        if (errorMessage)
-            *errorMessage = tr("Could not write tool specification %1: %2").
-                            arg(m_fileName, file.errorString());
-        return false;
+    Utils::FileSaver saver(m_fileName);
+    if (!saver.hasError()) {
+        QXmlStreamWriter out(saver.file());
+        out.setAutoFormatting(true);
+        out.writeStartDocument(QLatin1String("1.0"));
+        out.writeComment(QString::fromLatin1("Written on %1 by Qt Creator %2")
+                         .arg(QDateTime::currentDateTime().toString(), QLatin1String(Constants::IDE_VERSION_LONG)));
+        out.writeStartElement(QLatin1String(kExternalTool));
+        out.writeAttribute(QLatin1String(kId), m_id);
+        out.writeTextElement(QLatin1String(kDescription), m_description);
+        out.writeTextElement(QLatin1String(kDisplayName), m_displayName);
+        out.writeTextElement(QLatin1String(kCategory), m_displayCategory);
+        if (m_order != -1)
+            out.writeTextElement(QLatin1String(kOrder), QString::number(m_order));
+
+        out.writeStartElement(QLatin1String(kExecutable));
+        out.writeAttribute(QLatin1String(kOutput), stringForOutputHandling(m_outputHandling));
+        out.writeAttribute(QLatin1String(kError), stringForOutputHandling(m_errorHandling));
+        out.writeAttribute(QLatin1String(kModifiesDocument), m_modifiesCurrentDocument ? QLatin1String(kYes) : QLatin1String(kNo));
+        foreach (const QString &executable, m_executables)
+            out.writeTextElement(QLatin1String(kPath), executable);
+        if (!m_arguments.isEmpty())
+            out.writeTextElement(QLatin1String(kArguments), m_arguments);
+        if (!m_input.isEmpty())
+            out.writeTextElement(QLatin1String(kInput), m_input);
+        if (!m_workingDirectory.isEmpty())
+            out.writeTextElement(QLatin1String(kWorkingDirectory), m_workingDirectory);
+        out.writeEndElement();
+
+        out.writeEndDocument();
+
+        saver.setResult(&out);
     }
-    QXmlStreamWriter out(&file);
-    out.setAutoFormatting(true);
-    out.writeStartDocument(QLatin1String("1.0"));
-    out.writeComment(QString::fromLatin1("Written on %1 by Qt Creator %2")
-                     .arg(QDateTime::currentDateTime().toString(), QLatin1String(Constants::IDE_VERSION_LONG)));
-    out.writeStartElement(QLatin1String(kExternalTool));
-    out.writeAttribute(QLatin1String(kId), m_id);
-    out.writeTextElement(QLatin1String(kDescription), m_description);
-    out.writeTextElement(QLatin1String(kDisplayName), m_displayName);
-    out.writeTextElement(QLatin1String(kCategory), m_displayCategory);
-    if (m_order != -1)
-        out.writeTextElement(QLatin1String(kOrder), QString::number(m_order));
-
-    out.writeStartElement(QLatin1String(kExecutable));
-    out.writeAttribute(QLatin1String(kOutput), stringForOutputHandling(m_outputHandling));
-    out.writeAttribute(QLatin1String(kError), stringForOutputHandling(m_errorHandling));
-    out.writeAttribute(QLatin1String(kModifiesDocument), m_modifiesCurrentDocument ? QLatin1String(kYes) : QLatin1String(kNo));
-    foreach (const QString &executable, m_executables)
-        out.writeTextElement(QLatin1String(kPath), executable);
-    if (!m_arguments.isEmpty())
-        out.writeTextElement(QLatin1String(kArguments), m_arguments);
-    if (!m_input.isEmpty())
-        out.writeTextElement(QLatin1String(kInput), m_input);
-    if (!m_workingDirectory.isEmpty())
-        out.writeTextElement(QLatin1String(kWorkingDirectory), m_workingDirectory);
-    out.writeEndElement();
-
-    out.writeEndDocument();
-    file.close();
-    return true;
+    return saver.finalize(errorMessage);
 }
 
 bool ExternalTool::operator==(const ExternalTool &other) const

src/plugins/cpaster/cpasterplugin.cpp

@@ -52,6 +52,7 @@
 #include <coreplugin/icore.h>
 #include <coreplugin/messagemanager.h>
 #include <utils/qtcassert.h>
+#include <utils/fileutils.h>
 #include <texteditor/basetexteditor.h>
 
 #include <QtCore/QtPlugin>
@@ -277,23 +278,6 @@ static inline QString tempFilePattern(const QString &prefix, const QString &exte
     return pattern;
 }
 
-typedef QSharedPointer<QTemporaryFile> TemporaryFilePtr;
-
-// Write an a temporary file.
-TemporaryFilePtr writeTemporaryFile(const QString &namePattern,
-                                    const QString &contents,
-                                    QString *errorMessage)
-{
-    TemporaryFilePtr tempFile(new QTemporaryFile(namePattern));
-    if (!tempFile->open()) {
-        *errorMessage = QString::fromLatin1("Unable to open temporary file %1").arg(tempFile->errorString());
-        return TemporaryFilePtr();
-    }
-    tempFile->write(contents.toUtf8());
-    tempFile->close();
-    return tempFile;
-}
-
 void CodepasterPlugin::finishFetch(const QString &titleDescription,
                                    const QString &content,
                                    bool error)
@@ -313,23 +297,21 @@ void CodepasterPlugin::finishFetch(const QString &titleDescription,
     // for the user and also to be able to tell a patch or diff in the VCS plugins
     // by looking at the file name of FileManager::currentFile() without expensive checking.
     // Default to "txt".
+    QByteArray byteContent = content.toUtf8();
     QString suffix;
-    if (const Core::MimeType mimeType = Core::ICore::instance()->mimeDatabase()->findByData(content.toUtf8()))
+    if (const Core::MimeType mimeType = Core::ICore::instance()->mimeDatabase()->findByData(byteContent))
         suffix = mimeType.preferredSuffix();
     if (suffix.isEmpty())
          suffix = QLatin1String("txt");
     const QString filePrefix = filePrefixFromTitle(titleDescription);
-    QString errorMessage;
-    TemporaryFilePtr tempFile = writeTemporaryFile(tempFilePattern(filePrefix, suffix), content, &errorMessage);
-    if (tempFile.isNull()) {
-        messageManager->printToOutputPane(errorMessage);
+    Utils::TempFileSaver saver(tempFilePattern(filePrefix, suffix));
+    saver.setAutoRemove(false);
+    saver.write(byteContent);
+    if (!saver.finalize()) {
+        messageManager->printToOutputPane(saver.errorString());
         return;
     }
-    // Keep the file and store in list of files to be removed.
-    tempFile->setAutoRemove(false);
-    const QString fileName = tempFile->fileName();
-    // Discard to temporary file to make sure it is closed and no changes are triggered.
-    tempFile = TemporaryFilePtr();
+    const QString fileName = saver.fileName();
     m_fetchedSnippets.push_back(fileName);
     // Open editor with title.
     Core::IEditor* editor = EditorManager::instance()->openEditor(fileName, QString(), EditorManager::ModeSwitch);

src/plugins/cpaster/fileshareprotocol.cpp

@@ -38,6 +38,7 @@
 #include <coreplugin/messageoutputwindow.h>
 
 #include <utils/qtcassert.h>
+#include <utils/fileutils.h>
 
 #include <QtCore/QXmlStreamReader>
 #include <QtCore/QXmlStreamAttribute>
@@ -195,27 +196,29 @@ void FileShareProtocol::paste(const QString &text,
                               const QString &description)
 {
     // Write out temp XML file
-    QTemporaryFile tempFile(m_settings->path + QLatin1Char('/') + QLatin1String(tempPatternC));
-    tempFile.setAutoRemove(false);
-    if (!tempFile.open()) {
-        const QString msg = tr("Unable to open a file for writing in %1: %2").arg(m_settings->path, tempFile.errorString());
-        Core::ICore::instance()->messageManager()->printToOutputPanePopup(msg);
+    Utils::TempFileSaver saver(m_settings->path + QLatin1Char('/') + QLatin1String(tempPatternC));
+    saver.setAutoRemove(false);
+    if (!saver.hasError()) {
+        // Flat text sections embedded into pasterElement
+        QXmlStreamWriter writer(saver.file());
+        writer.writeStartDocument();
+        writer.writeStartElement(QLatin1String(pasterElementC));
+
+        writer.writeTextElement(QLatin1String(userElementC), username);
+        writer.writeTextElement(QLatin1String(descriptionElementC), description);
+        writer.writeTextElement(QLatin1String(textElementC), text);
+
+        writer.writeEndElement();
+        writer.writeEndDocument();
+
+        saver.setResult(&writer);
+    }
+    if (!saver.finalize()) {
+        Core::ICore::instance()->messageManager()->printToOutputPanePopup(saver.errorString());
         return;
     }
-    // Flat text sections embedded into pasterElement
-    QXmlStreamWriter writer(&tempFile);
-    writer.writeStartDocument();
-    writer.writeStartElement(QLatin1String(pasterElementC));
-
-    writer.writeTextElement(QLatin1String(userElementC), username);
-    writer.writeTextElement(QLatin1String(descriptionElementC), description);
-    writer.writeTextElement(QLatin1String(textElementC), text);
-
-    writer.writeEndElement();
-    writer.writeEndDocument();
-    tempFile.close();
 
-    const QString msg = tr("Pasted: %1").arg(tempFile.fileName());
+    const QString msg = tr("Pasted: %1").arg(saver.fileName());
     Core::ICore::instance()->messageManager()->printToOutputPanePopup(msg);
 }
 } // namespace CodePaster

src/plugins/cpptools/cppfilesettingspage.cpp

@@ -41,6 +41,8 @@
 
 #include <extensionsystem/pluginmanager.h>
 
+#include <utils/fileutils.h>
+
 #include <QtCore/QSettings>
 #include <QtCore/QDebug>
 #include <QtCore/QFile>
@@ -301,25 +303,18 @@ void CppFileSettingsWidget::setSettings(const CppFileSettings &s)
 void CppFileSettingsWidget::slotEdit()
 {
     QString path = licenseTemplatePath();
-    // Edit existing file with C++
-    if (!path.isEmpty()) {
-        Core::EditorManager::instance()->openEditor(path, QLatin1String(CppEditor::Constants::CPPEDITOR_ID),
-                                                    Core::EditorManager::ModeSwitch);
-        return;
-    }
-    // Pick a file name and write new template, edit with C++
-    path = QFileDialog::getSaveFileName(this, tr("Choose Location for New License Template File"));
-    if (path.isEmpty())
-        return;
-    QFile file(path);
-    if (!file.open(QIODevice::WriteOnly|QIODevice::Text|QIODevice::Truncate)) {
-        QMessageBox::warning(this, tr("Template write error"),
-                             tr("Cannot write to %1: %2").arg(path, file.errorString()));
-        return;
+    if (path.isEmpty()) {
+        // Pick a file name and write new template, edit with C++
+        path = QFileDialog::getSaveFileName(this, tr("Choose Location for New License Template File"));
+        if (path.isEmpty())
+            return;
+        Utils::FileSaver saver(path, QIODevice::Text);
+        saver.write(tr(licenseTemplateTemplate).toUtf8());
+        if (!saver.finalize(this))
+            return;
+        setLicenseTemplatePath(path);
     }
-    file.write(tr(licenseTemplateTemplate).toUtf8());
-    file.close();
-    setLicenseTemplatePath(path);
+    // Edit (now) existing file with C++
     Core::EditorManager::instance()->openEditor(path, QLatin1String(CppEditor::Constants::CPPEDITOR_ID),
                                                 Core::EditorManager::ModeSwitch);
 }

src/plugins/cpptools/cppfindreferences.cpp

@@ -38,6 +38,7 @@
 #include <find/searchresultwindow.h>
 #include <extensionsystem/pluginmanager.h>
 #include <utils/filesearch.h>
+#include <utils/fileutils.h>
 #include <coreplugin/progressmanager/progressmanager.h>
 #include <coreplugin/progressmanager/futureprogress.h>
 #include <coreplugin/editormanager/editormanager.h>
@@ -76,11 +77,11 @@ static QString getSource(const QString &fileName,
     if (workingCopy.contains(fileName)) {
         return workingCopy.source(fileName);
     } else {
-        QFile file(fileName);
-        if (! file.open(QFile::ReadOnly))
+        Utils::FileReader reader;
+        if (!reader.fetch(fileName)) // ### FIXME error reporting
             return QString();
 
-        return QTextStream(&file).readAll(); // ### FIXME
+        return QString::fromLocal8Bit(reader.data()); // ### FIXME encoding
     }
 }
 

src/plugins/cvs/cvsplugin.cpp

@@ -60,6 +60,7 @@
 #include <coreplugin/editormanager/editormanager.h>