CppTools: Use editor manager's codec as fallback

...for reading not already opened files.

This partly reverts commit f7c68f6. In case TextFileFormat::detect()
fails, the user configurable editor manager's codec is used instead of
QTextCodec::codecForLocale().

Adds also a qWarning() to easier detect encoding errors.

Task-number: QTCREATORBUG-10378

Change-Id: I0fa4e6b898ed090d85414ce2a001f11b115a42d3
Reviewed-by: Oswald Buddenhagen <oswald.buddenhagen@digia.com>
Reviewed-by: Eike Ziller <eike.ziller@digia.com>
Reviewed-by: Erik Verbruggen <erik.verbruggen@digia.com>

src/libs/utils/textfileformat.cpp

@@ -304,6 +304,40 @@ TextFileFormat::ReadResult TextFileFormat::readFileUTF8(const QString &fileName,
     return TextFileFormat::ReadSuccess;
 }
 
+TextFileFormat::ReadResult TextFileFormat::readFileUTF8(const QString &fileName,
+                                                        const QTextCodec *defaultCodec,
+                                                        QByteArray *plainText, QString *errorString)
+{
+    QByteArray data;
+    try {
+        Utils::FileReader reader;
+        if (!reader.fetch(fileName, errorString))
+            return Utils::TextFileFormat::ReadIOError;
+        data = reader.data();
+    } catch (const std::bad_alloc &) {
+        *errorString = QCoreApplication::translate("Utils::TextFileFormat", "Out of memory.");
+        return Utils::TextFileFormat::ReadMemoryAllocationError;
+    }
+
+    Utils::TextFileFormat format = Utils::TextFileFormat::detect(data);
+    if (!format.codec)
+        format.codec = defaultCodec ? defaultCodec : QTextCodec::codecForLocale();
+    if (format.codec->name() == "UTF-8") {
+        if (format.hasUtf8Bom)
+            data.remove(0, 3);
+        *plainText = data;
+        return Utils::TextFileFormat::ReadSuccess;
+    }
+
+    QString target;
+    if (!format.decode(data, &target)) {
+        *errorString = QCoreApplication::translate("Utils::TextFileFormat", "An encoding error was encountered.");
+        return Utils::TextFileFormat::ReadEncodingError;
+    }
+    *plainText = target.toUtf8();
+    return Utils::TextFileFormat::ReadSuccess;
+}
+
 /*!
     Writes out a text file.
 */

src/libs/utils/textfileformat.h

@@ -77,7 +77,9 @@ public:
                                QString *plainText, TextFileFormat *format, QString *errorString,
                                QByteArray *decodingErrorSample = 0);
     static ReadResult readFileUTF8(const QString &fileName, QByteArray *plainText,
-                                   QString *errorString);
+                                   QString *errorString); // TODO: Remove this version.
+    static ReadResult readFileUTF8(const QString &fileName, const QTextCodec *defaultCodec,
+                                   QByteArray *plainText, QString *errorString);
 
     bool writeFile(const QString &fileName, QString plainText, QString *errorString) const;
 

src/plugins/cpptools/cpppreprocessor.cpp

@@ -2,11 +2,15 @@
 
 #include "cppmodelmanager.h"
 
+#include <coreplugin/editormanager/editormanager.h>
+
+#include <utils/fileutils.h>
 #include <utils/hostosinfo.h>
 #include <utils/textfileformat.h>
 
 #include <QCoreApplication>
 #include <QCryptographicHash>
+#include <QTextCodec>
 
 /*!
  * \class CppTools::Internal::CppPreprocessor
@@ -30,7 +34,8 @@ CppPreprocessor::CppPreprocessor(QPointer<CppModelManager> modelManager,
       m_modelManager(modelManager),
       m_dumpFileNameWhileParsing(dumpFileNameWhileParsing),
       m_preprocess(this, &m_env),
-      m_revision(0)
+      m_revision(0),
+      m_defaultCodec(Core::EditorManager::defaultTextCodec())
 {
     m_preprocess.setKeepComments(true);
 }
@@ -41,7 +46,8 @@ CppPreprocessor::CppPreprocessor(QPointer<CppModelManager> modelManager, const S
       m_modelManager(modelManager),
       m_dumpFileNameWhileParsing(dumpFileNameWhileParsing),
       m_preprocess(this, &m_env),
-      m_revision(0)
+      m_revision(0),
+      m_defaultCodec(Core::EditorManager::defaultTextCodec())
 {
     m_preprocess.setKeepComments(true);
 }
@@ -182,9 +188,14 @@ void CppPreprocessor::getFileContents(const QString &absoluteFilePath,
         return;
     }
 
-    QString errStr;
-    if (contents)
-        Utils::TextFileFormat::readFileUTF8(absoluteFilePath, contents, &errStr);
+    if (contents) {
+        QString error;
+        if (Utils::TextFileFormat::readFileUTF8(absoluteFilePath, m_defaultCodec, contents, &error)
+                != Utils::TextFileFormat::ReadSuccess) {
+            qWarning("Error reading file \"%s\": \"%s\".", qPrintable(absoluteFilePath),
+                     qPrintable(error));
+        }
+    }
     if (revision)
         *revision = 0;
 }

src/plugins/cpptools/cpppreprocessor.h

@@ -9,6 +9,10 @@
 #include <QHash>
 #include <QPointer>
 
+QT_BEGIN_NAMESPACE
+class QTextCodec;
+QT_END_NAMESPACE
+
 namespace CppTools {
 namespace Internal {
 
@@ -75,6 +79,7 @@ protected:
     virtual void sourceNeeded(unsigned line, const QString &fileName, IncludeType type);
 
 private:
+    CppPreprocessor();
     void addFrameworkPath(const QString &frameworkPath);
 
     CPlusPlus::Snapshot m_snapshot;
@@ -92,6 +97,7 @@ private:
     QSet<QString> m_processed;
     unsigned m_revision;
     QHash<QString, QString> m_fileNameCache;
+    QTextCodec *m_defaultCodec;
 };
 
 } // namespace Internal