Replace QArrayData::capacityReserved with a full flags field

Instead of stealing one bit from the alloc field, let's use a full
32-bit for the flags. The first flag to be in the field is the
CapacityReserved (even though the allocate() function will store some
others there, not relevant for now).

This is done in preparation for the need for more flags necessary
anyway.

Change-Id: I4c997d14743495e0d4558a6fb0a6042eb3d4975d
Reviewed-by: Simon Hausmann <simon.hausmann@qt.io>

1 files changed, 4 insertions, 11 deletions

diff --git a/src/corelib/tools/qvector.h b/src/corelib/tools/qvector.h
index 3220ba1463..d64673cc16 100644
--- a/src/corelib/tools/qvector.h
+++ b/src/corelib/tools/qvector.h
@@ -119,12 +119,7 @@ public:
                 *this = QVector<T>();
                 return;
             }
-            realloc(d->size);
-        }
-        if (d->capacityReserved) {
-            // capacity reserved in a read only memory would be useless
-            // this checks avoid writing to such memory.
-            d->capacityReserved = 0;
+            realloc(d->size, QArrayData::ArrayOptions(d->flags));
         }
     }
 
@@ -376,10 +371,10 @@ inline QVector<T>::QVector(const QVector<T> &v)
     if (v.d->ref.ref()) {
         d = v.d;
     } else {
-        if (v.d->capacityReserved) {
+        if (v.d->flags & Data::CapacityReserved) {
             d = Data::allocate(v.d->alloc);
             Q_CHECK_PTR(d);
-            d->capacityReserved = true;
+            d->flags |= Data::CapacityReserved;
         } else {
             d = Data::allocate(v.d->size);
             Q_CHECK_PTR(d);
@@ -412,7 +407,7 @@ void QVector<T>::reserve(int asize)
     if (asize > int(d->alloc))
         realloc(asize);
     if (isDetached())
-        d->capacityReserved = 1;
+        d->flags |= Data::CapacityReserved;
     Q_ASSERT(capacity() >= asize);
 }
 
@@ -644,7 +639,6 @@ void QVector<T>::reallocData(const int asize, const int aalloc, QArrayData::Arra
                 Data::deallocate(x);
                 QT_RETHROW;
             }
-            x->capacityReserved = d->capacityReserved;
         } else {
             Q_ASSERT(int(d->alloc) == aalloc); // resize, without changing allocation size
             Q_ASSERT(isDetached());       // can be done only on detached d
@@ -723,7 +717,6 @@ void QVector<T>::realloc(int aalloc, QArrayData::ArrayOptions options)
         Data::deallocate(x);
         QT_RETHROW;
     }
-    x->capacityReserved = d->capacityReserved;
 
     Q_ASSERT(d != x);
     if (!d->ref.deref()) {