From d4cee10bf8e1460bc569e0ee392fd33d21f6cf80 Mon Sep 17 00:00:00 2001
From: Marc Mutz <marc.mutz@kdab.com>
Date: Sun, 14 Jun 2015 11:09:49 +0200
Subject: [PATCH] QMetaObjectBuilder: replace inefficient QLists with QVector

The QMeta*Private classes are larger than a void*, and weren't
marked as movable, so QList<QMeta*Private> is horribly inefficient.

Fix by holding them in QVector instead. Saves ~900B in text size
on GCC 4.9 optimized C++11 AMD64 Linux builds, and tons of memory
allocations.

Change-Id: I313c965d7a0fea16f79e9fde04a972fc248e33aa
Reviewed-by: Lars Knoll <lars.knoll@theqtcompany.com>
---
 src/corelib/kernel/qmetaobjectbuilder.cpp | 18 ++++++++++++------
 1 file changed, 12 insertions(+), 6 deletions(-)

diff --git a/src/corelib/kernel/qmetaobjectbuilder.cpp b/src/corelib/kernel/qmetaobjectbuilder.cpp
index a1b8125121..62119c86d6 100644
--- a/src/corelib/kernel/qmetaobjectbuilder.cpp
+++ b/src/corelib/kernel/qmetaobjectbuilder.cpp
@@ -88,6 +88,7 @@ static inline Q_DECL_UNUSED const QMetaObjectPrivate *priv(const uint* data)
 class QMetaMethodBuilderPrivate
 {
 public:
+    QMetaMethodBuilderPrivate() {} // for QVector, don't use
     QMetaMethodBuilderPrivate
             (QMetaMethod::MethodType _methodType,
              const QByteArray& _signature,
@@ -139,10 +140,12 @@ public:
         return signature.left(qMax(signature.indexOf('('), 0));
     }
 };
+Q_DECLARE_TYPEINFO(QMetaMethodBuilderPrivate, Q_MOVABLE_TYPE);
 
 class QMetaPropertyBuilderPrivate
 {
 public:
+    QMetaPropertyBuilderPrivate() {} // for QVector, don't use
     QMetaPropertyBuilderPrivate
             (const QByteArray& _name, const QByteArray& _type, int notifierIdx=-1,
              int _revision = 0)
@@ -176,10 +179,12 @@ public:
             flags &= ~f;
     }
 };
+Q_DECLARE_TYPEINFO(QMetaPropertyBuilderPrivate, Q_MOVABLE_TYPE);
 
 class QMetaEnumBuilderPrivate
 {
 public:
+    QMetaEnumBuilderPrivate() {} // for QVector, don't use
     QMetaEnumBuilderPrivate(const QByteArray& _name)
         : name(_name), isFlag(false)
     {
@@ -190,6 +195,7 @@ public:
     QList<QByteArray> keys;
     QList<int> values;
 };
+Q_DECLARE_TYPEINFO(QMetaEnumBuilderPrivate, Q_MOVABLE_TYPE);
 
 class QMetaObjectBuilderPrivate
 {
@@ -207,12 +213,12 @@ public:
     QByteArray className;
     const QMetaObject *superClass;
     QMetaObjectBuilder::StaticMetacallFunction staticMetacallFunction;
-    QList<QMetaMethodBuilderPrivate> methods;
-    QList<QMetaMethodBuilderPrivate> constructors;
-    QList<QMetaPropertyBuilderPrivate> properties;
+    QVector<QMetaMethodBuilderPrivate> methods;
+    QVector<QMetaMethodBuilderPrivate> constructors;
+    QVector<QMetaPropertyBuilderPrivate> properties;
     QList<QByteArray> classInfoNames;
     QList<QByteArray> classInfoValues;
-    QList<QMetaEnumBuilderPrivate> enumerators;
+    QVector<QMetaEnumBuilderPrivate> enumerators;
     QList<const QMetaObject *> relatedMetaObjects;
     int flags;
 };
@@ -1149,7 +1155,7 @@ void QMetaStringTable::writeBlob(char *out) const
 // Returns the sum of all parameters (including return type) for the given
 // \a methods. This is needed for calculating the size of the methods'
 // parameter type/name meta-data.
-static int aggregateParameterCount(const QList<QMetaMethodBuilderPrivate> &methods)
+static int aggregateParameterCount(const QVector<QMetaMethodBuilderPrivate> &methods)
 {
     int sum = 0;
     for (int i = 0; i < methods.size(); ++i)
@@ -1330,7 +1336,7 @@ static int buildMetaObject(QMetaObjectBuilderPrivate *d, char *buf,
     Q_ASSERT(!buf || dataIndex == pmeta->methodData + d->methods.size() * 5
              + (hasRevisionedMethods ? d->methods.size() : 0));
     for (int x = 0; x < 2; ++x) {
-        QList<QMetaMethodBuilderPrivate> &methods = (x == 0) ? d->methods : d->constructors;
+        QVector<QMetaMethodBuilderPrivate> &methods = (x == 0) ? d->methods : d->constructors;
         for (index = 0; index < methods.size(); ++index) {
             QMetaMethodBuilderPrivate *method = &(methods[index]);
             QList<QByteArray> paramTypeNames = method->parameterTypes();