Add QDebug::noquote() stream modifier

Allow the user to disable the quoting of QString, QByteArray,
QStringLiteral by passing a "noquote()" stream modifier.

This requires another flag to be added to QDebug::Stream. To
keep BC we're using the QMessageLogContext::version field
to differentiate between QDebug streams created by earlier
versions.

Task-number: QTBUG-37146
Change-Id: I9b215eabfcfd754af16ea87f3ef928d698e37d77
Reviewed-by: Jerome Pasion <jerome.pasion@digia.com>
Reviewed-by: Thiago Macieira <thiago.macieira@intel.com>

3 files changed, 69 insertions, 9 deletions

diff --git a/src/corelib/global/qlogging.h b/src/corelib/global/qlogging.h
index 6ebffa3ba1..043f799414 100644
--- a/src/corelib/global/qlogging.h
+++ b/src/corelib/global/qlogging.h
@@ -65,9 +65,9 @@ class QMessageLogContext
 {
     Q_DISABLE_COPY(QMessageLogContext)
 public:
-    Q_DECL_CONSTEXPR QMessageLogContext() : version(1), line(0), file(0), function(0), category(0) {}
+    Q_DECL_CONSTEXPR QMessageLogContext() : version(2), line(0), file(0), function(0), category(0) {}
     Q_DECL_CONSTEXPR QMessageLogContext(const char *fileName, int lineNumber, const char *functionName, const char *categoryName)
-        : version(1), line(lineNumber), file(fileName), function(functionName), category(categoryName) {}
+        : version(2), line(lineNumber), file(fileName), function(functionName), category(categoryName) {}
 
     void copy(const QMessageLogContext &logContext);
 
diff --git a/src/corelib/io/qdebug.cpp b/src/corelib/io/qdebug.cpp
index 44d0a788ff..038e9cb0a3 100644
--- a/src/corelib/io/qdebug.cpp
+++ b/src/corelib/io/qdebug.cpp
@@ -202,6 +202,41 @@ QDebug::~QDebug()
     \sa QDebugStateSaver
 */
 
+
+/*!
+    \fn QDebug &QDebug::quote()
+    \since 5.4
+
+    Enables automatic insertion of quotation characters around QChar, QString and QByteArray
+    contents and returns a reference to the stream.
+
+    Quoting is enabled by default.
+
+    \sa noquote(), maybeQuote()
+*/
+
+/*!
+    \fn QDebug &QDebug::noquote()
+    \since 5.4
+
+    Disables automatic insertion of quotation characters around QChar, QString and QByteArray
+    contents and returns a reference to the stream.
+
+    \sa quote(), maybeQuote()
+*/
+
+/*!
+    \fn QDebug &QDebug::maybeQuote(char c)
+    \since 5.4
+
+    Writes a character \a c to the debug stream, depending on the
+    current setting for automatic insertion of quotes, and returns a reference to the stream.
+
+    The default character is a double quote \c{"}.
+
+    \sa quote(), noquote()
+*/
+
 /*!
     \fn QDebug &QDebug::operator<<(QChar t)
 
@@ -368,19 +403,25 @@ public:
     QDebugStateSaverPrivate(QDebug &dbg)
         : m_dbg(dbg),
           m_spaces(dbg.autoInsertSpaces()),
+          m_flags(0),
           m_streamParams(dbg.stream->ts.d_ptr->params)
     {
+        if (m_dbg.stream->context.version > 1)
+            m_flags = m_dbg.stream->flags;
     }
     void restoreState()
     {
         m_dbg.setAutoInsertSpaces(m_spaces);
         m_dbg.stream->ts.d_ptr->params = m_streamParams;
+        if (m_dbg.stream->context.version > 1)
+            m_dbg.stream->flags = m_flags;
     }
 
     QDebug &m_dbg;
 
     // QDebug state
     const bool m_spaces;
+    int m_flags;
 
     // QTextStream state
     const QTextStreamPrivate::Params m_streamParams;
diff --git a/src/corelib/io/qdebug.h b/src/corelib/io/qdebug.h
index 584d6bf41f..0bbb617c1f 100644
--- a/src/corelib/io/qdebug.h
+++ b/src/corelib/io/qdebug.h
@@ -61,9 +61,9 @@ class Q_CORE_EXPORT QDebug
     friend class QMessageLogger;
     friend class QDebugStateSaverPrivate;
     struct Stream {
-        Stream(QIODevice *device) : ts(device), ref(1), type(QtDebugMsg), space(true), message_output(false) {}
-        Stream(QString *string) : ts(string, QIODevice::WriteOnly), ref(1), type(QtDebugMsg), space(true), message_output(false) {}
-        Stream(QtMsgType t) : ts(&buffer, QIODevice::WriteOnly), ref(1), type(t), space(true), message_output(true) {}
+        Stream(QIODevice *device) : ts(device), ref(1), type(QtDebugMsg), space(true), message_output(false), flags(0) {}
+        Stream(QString *string) : ts(string, QIODevice::WriteOnly), ref(1), type(QtDebugMsg), space(true), message_output(false), flags(0) {}
+        Stream(QtMsgType t) : ts(&buffer, QIODevice::WriteOnly), ref(1), type(t), space(true), message_output(true), flags(0) {}
         QTextStream ts;
         QString buffer;
         int ref;
@@ -71,6 +71,18 @@ class Q_CORE_EXPORT QDebug
         bool space;
         bool message_output;
         QMessageLogContext context;
+
+        enum FormatFlag {
+            NoQuotes = 0x1
+        };
+
+        // ### Qt 6: unify with space, introduce own version member
+        bool testFlag(FormatFlag flag) const { return (context.version > 1) ? (flags & flag) : false; }
+        void setFlag(FormatFlag flag) { if (context.version > 1) { flags |= flag; } }
+        void unsetFlag(FormatFlag flag) { if (context.version > 1) { flags &= ~flag; } }
+
+        // added in 5.4
+        int flags;
     } *stream;
 public:
     inline QDebug(QIODevice *device) : stream(new Stream(device)) {}
@@ -88,7 +100,11 @@ public:
     bool autoInsertSpaces() const { return stream->space; }
     void setAutoInsertSpaces(bool b) { stream->space = b; }
 
-    inline QDebug &operator<<(QChar t) { stream->ts << '\'' << t << '\''; return maybeSpace(); }
+    inline QDebug &quote() { stream->unsetFlag(Stream::NoQuotes); return *this; }
+    inline QDebug &noquote() { stream->setFlag(Stream::NoQuotes); return *this; }
+    inline QDebug &maybeQuote(char c = '"') { if (!(stream->testFlag(Stream::NoQuotes))) stream->ts << c; return *this; }
+
+    inline QDebug &operator<<(QChar t) { maybeQuote('\''); stream->ts << t; maybeQuote('\''); return maybeSpace(); }
     inline QDebug &operator<<(bool t) { stream->ts << (t ? "true" : "false"); return maybeSpace(); }
     inline QDebug &operator<<(char t) { stream->ts << t; return maybeSpace(); }
     inline QDebug &operator<<(signed short t) { stream->ts << t; return maybeSpace(); }
@@ -102,10 +118,10 @@ public:
     inline QDebug &operator<<(float t) { stream->ts << t; return maybeSpace(); }
     inline QDebug &operator<<(double t) { stream->ts << t; return maybeSpace(); }
     inline QDebug &operator<<(const char* t) { stream->ts << QString::fromUtf8(t); return maybeSpace(); }
-    inline QDebug &operator<<(const QString & t) { stream->ts << '\"' << t  << '\"'; return maybeSpace(); }
+    inline QDebug &operator<<(const QString & t) { maybeQuote(); stream->ts << t; maybeQuote(); return maybeSpace(); }
     inline QDebug &operator<<(const QStringRef & t) { return operator<<(t.toString()); }
-    inline QDebug &operator<<(QLatin1String t) { stream->ts << '\"'  << t << '\"'; return maybeSpace(); }
-    inline QDebug &operator<<(const QByteArray & t) { stream->ts  << '\"' << t << '\"'; return maybeSpace(); }
+    inline QDebug &operator<<(QLatin1String t) { maybeQuote(); stream->ts << t; maybeQuote(); return maybeSpace(); }
+    inline QDebug &operator<<(const QByteArray & t) { maybeQuote(); stream->ts << t; maybeQuote(); return maybeSpace(); }
     inline QDebug &operator<<(const void * t) { stream->ts << t; return maybeSpace(); }
     inline QDebug &operator<<(QTextStreamFunction f) {
         stream->ts << f;
@@ -137,6 +153,9 @@ public:
     inline QNoDebug &space() { return *this; }
     inline QNoDebug &nospace() { return *this; }
     inline QNoDebug &maybeSpace() { return *this; }
+    inline QNoDebug &quote() { return *this; }
+    inline QNoDebug &noquote() { return *this; }
+    inline QNoDebug &maybeQuote(const char = '"') { return *this; }
 
     template<typename T>
     inline QNoDebug &operator<<(const T &) { return *this; }