1 files changed, 18 insertions, 8 deletions

diff --git a/src/tools/moc/preprocessor.cpp b/src/tools/moc/preprocessor.cpp
index 087b064c0f..ff435085b4 100644
--- a/src/tools/moc/preprocessor.cpp
+++ b/src/tools/moc/preprocessor.cpp
@@ -52,11 +52,12 @@ static QByteArray cleaned(const QByteArray &input)
     QByteArray result;
     result.reserve(input.size());
     const char *data = input.constData();
+    const char *end = input.constData() + input.size();
     char *output = result.data();
 
     int newlines = 0;
-    while (*data) {
-        while (*data && is_space(*data))
+    while (data != end) {
+        while (data != end && is_space(*data))
             ++data;
         bool takeLine = (*data == '#');
         if (*data == '%' && *(data+1) == ':') {
@@ -66,15 +67,15 @@ static QByteArray cleaned(const QByteArray &input)
         if (takeLine) {
             *output = '#';
             ++output;
-            do ++data; while (*data && is_space(*data));
+            do ++data; while (data != end && is_space(*data));
         }
-        while (*data) {
+        while (data != end) {
             // handle \\\n, \\\r\n and \\\r
             if (*data == '\\') {
                 if (*(data + 1) == '\r') {
                     ++data;
                 }
-                if (*data && (*(data + 1) == '\n' || (*data) == '\r')) {
+                if (data != end && (*(data + 1) == '\n' || (*data) == '\r')) {
                     ++newlines;
                     data += 1;
                     if (*data != '\r')
@@ -964,6 +965,13 @@ int Preprocessor::evaluateCondition()
     return expression.value();
 }
 
+static QByteArray readOrMapFile(QFile *file)
+{
+    const qint64 size = file->size();
+    char *rawInput = reinterpret_cast<char*>(file->map(0, size));
+    return rawInput ? QByteArray::fromRawData(rawInput, size) : file->readAll();
+}
+
 void Preprocessor::preprocess(const QByteArray &filename, Symbols &preprocessed)
 {
     currentFilenames.push(filename);
@@ -1020,7 +1028,8 @@ void Preprocessor::preprocess(const QByteArray &filename, Symbols &preprocessed)
             if (!file.open(QFile::ReadOnly))
                 continue;
 
-            QByteArray input = file.readAll();
+            QByteArray input = readOrMapFile(&file);
+
             file.close();
             if (input.isEmpty())
                 continue;
@@ -1157,9 +1166,10 @@ void Preprocessor::preprocess(const QByteArray &filename, Symbols &preprocessed)
     currentFilenames.pop();
 }
 
-Symbols Preprocessor::preprocessed(const QByteArray &filename, QIODevice *file)
+Symbols Preprocessor::preprocessed(const QByteArray &filename, QFile *file)
 {
-    QByteArray input = file->readAll();
+    QByteArray input = readOrMapFile(file);
+
     if (input.isEmpty())
         return symbols;