From a959f34d716f42925b22d42838e7a4b97e415c69 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Jo=C3=A3o=20Abecasis?= <joao.abecasis@nokia.com>
Date: Sun, 1 Apr 2012 01:05:47 +0200
Subject: Clean up constructors for "statics" in QString and QByteArray

There were two constuctors offering essentially the same functionality.
One taking the QStatic*Data<N> struct, the other what essentially
amounts to a pointer wrapper of that struct. The former was dropped and
the latter untemplatized and kept, as that is the most generic and
widely applicable. The template parameter in the wrapper was not very
useful as it essentially duplicated information that already maintained
in the struct, and there were no consistency checks to ensure they were
in sync.

In this case, using a wrapper is preferred over the use of naked
pointers both as a way to make explicit the transfer of ownership as
well as to avoid unintended conversions. By using the reference count
(even if only by calling deref() in the destructor), QByteArray and
QString must own their Data pointers.

Const qualification was dropped from the member variable in these
wrappers as it causes some compilers to emit warnings on the lack of
constructors, and because it isn't needed there.

To otherwise reduce noise, QStatic*Data<N> gained a member function to
directly access the const_cast'ed naked pointer. This plays nicely with
the above constructor. Its use also allows us to do further changes in
the QStatic*Data structs with fewer changes in remaining code. The
function has an assert on isStatic(), to ensure it is not inadvertently
used with data that requires ref-count operations.

With this change, the need for the private constructor taking a naked
Q*Data pointer is obviated and that was dropped too.

In updating QStringBuilder's QConcatenable specializations I noticed
they were broken (using data, instead of data()), so a test was added to
avoid this happening again in the future.

An unnecessary ref-count increment in QByteArray::clear was also
dropped.

Change-Id: I9b92fbaae726ab9807837e83d0d19812bf7db5ab
Reviewed-by: Thiago Macieira <thiago.macieira@intel.com>
---
 src/corelib/tools/qstringbuilder.h | 22 +++++++++++-----------
 1 file changed, 11 insertions(+), 11 deletions(-)

(limited to 'src/corelib/tools/qstringbuilder.h')

diff --git a/src/corelib/tools/qstringbuilder.h b/src/corelib/tools/qstringbuilder.h
index 0b85e590cd..9a1fd6949b 100644
--- a/src/corelib/tools/qstringbuilder.h
+++ b/src/corelib/tools/qstringbuilder.h
@@ -253,16 +253,16 @@ template <> struct QConcatenable<QString> : private QAbstractConcatenable
     }
 };
 
-template <int N> struct QConcatenable<QStaticStringDataPtr<N> > : private QAbstractConcatenable
+template <> struct QConcatenable<QStringDataPtr> : private QAbstractConcatenable
 {
-    typedef QStaticStringDataPtr<N> type;
+    typedef QStringDataPtr type;
     typedef QString ConvertTo;
     enum { ExactSize = true };
-    static int size(const type &) { return N; }
+    static int size(const type &a) { return a.ptr->size; }
     static inline void appendTo(const type &a, QChar *&out)
     {
-        memcpy(out, reinterpret_cast<const char*>(a.ptr->data), sizeof(QChar) * N);
-        out += N;
+        memcpy(out, reinterpret_cast<const char*>(a.ptr->data()), sizeof(QChar) * a.ptr->size);
+        out += a.ptr->size;
     }
 };
 
@@ -358,22 +358,22 @@ template <> struct QConcatenable<QByteArray> : private QAbstractConcatenable
     }
 };
 
-template <int N> struct QConcatenable<QStaticByteArrayDataPtr<N> > : private QAbstractConcatenable
+template <> struct QConcatenable<QByteArrayDataPtr> : private QAbstractConcatenable
 {
-    typedef QStaticByteArrayDataPtr<N> type;
+    typedef QByteArrayDataPtr type;
     typedef QByteArray ConvertTo;
     enum { ExactSize = false };
-    static int size(const type &) { return N; }
+    static int size(const type &ba) { return ba.ptr->size; }
 #ifndef QT_NO_CAST_FROM_ASCII
     static inline QT_ASCII_CAST_WARN void appendTo(const type &a, QChar *&out)
     {
-        QAbstractConcatenable::convertFromAscii(a.ptr->data, N, out);
+        QAbstractConcatenable::convertFromAscii(a.ptr->data(), a.ptr->size, out);
     }
 #endif
     static inline void appendTo(const type &ba, char *&out)
     {
-        ::memcpy(out, ba.ptr->data, N);
-        out += N;
+        ::memcpy(out, ba.ptr->data(), ba.ptr->size);
+        out += ba.ptr->size;
     }
 };
 
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