tdf#89522 PERF FILEOPEN xlsx, part 1

Inherit from tools::WeakBase non-virtually, so that we can use a
static_cast in tools::WeakReference::get instead of a dynamic_cast.

This takes the file-open time from 1m21 to 40s for me.

Add a clang plugin to make sure we don't accidentally end up inheriting
from tools::WeakBase more than once.

Change-Id: I9c7c36403333f99094e1f9d8cce2ecd9200377f9
Reviewed-on: https://gerrit.libreoffice.org/71231
Reviewed-by: Noel Grandin <noel.grandin@collabora.co.uk>
Tested-by: Noel Grandin <noel.grandin@collabora.co.uk>

6 files changed, 9 insertions, 8 deletions

diff --git a/include/svx/svdmodel.hxx b/include/svx/svdmodel.hxx
index 9dad1baa8cc1..e2dc48461c78 100644
--- a/include/svx/svdmodel.hxx
+++ b/include/svx/svdmodel.hxx
@@ -143,7 +143,7 @@ public:
 
 struct SdrModelImpl;
 
-class SVX_DLLPUBLIC SdrModel : public SfxBroadcaster, public virtual tools::WeakBase
+class SVX_DLLPUBLIC SdrModel : public SfxBroadcaster, public tools::WeakBase
 {
 private:
 #ifdef DBG_UTIL
diff --git a/include/svx/svdobj.hxx b/include/svx/svdobj.hxx
index 9de436daa7e8..0d2d836f8efc 100644
--- a/include/svx/svdobj.hxx
+++ b/include/svx/svdobj.hxx
@@ -304,7 +304,7 @@ public:
 //      SwFlyDrawObj
 
 /// Abstract DrawObject
-class SVX_DLLPUBLIC SdrObject : public SfxListener, public virtual tools::WeakBase
+class SVX_DLLPUBLIC SdrObject : public SfxListener, public tools::WeakBase
 {
 private:
     friend class                SdrObjListIter;
diff --git a/include/svx/svdpage.hxx b/include/svx/svdpage.hxx
index 24747bc823a9..d23957dcd906 100644
--- a/include/svx/svdpage.hxx
+++ b/include/svx/svdpage.hxx
@@ -364,7 +364,7 @@ public:
 //          SwDPage
 //      OReportPage
 
-class SVX_DLLPUBLIC SdrPage : public SdrObjList, public virtual tools::WeakBase
+class SVX_DLLPUBLIC SdrPage : public SdrObjList, public tools::WeakBase
 {
     // #i9076#
     friend class SdrModel;
diff --git a/include/svx/svdtext.hxx b/include/svx/svdtext.hxx
index 1f96268c7e88..a02d9390ef3e 100644
--- a/include/svx/svdtext.hxx
+++ b/include/svx/svdtext.hxx
@@ -41,7 +41,7 @@ namespace sdr { namespace properties {
 */
 
 class SfxStyleSheet;
-class SVX_DLLPUBLIC SdrText : public virtual tools::WeakBase
+class SVX_DLLPUBLIC SdrText : public tools::WeakBase
 {
 public:
     explicit SdrText( SdrTextObj& rObject );
diff --git a/include/svx/svdview.hxx b/include/svx/svdview.hxx
index c0d3b21a8f42..176d6e6146b5 100644
--- a/include/svx/svdview.hxx
+++ b/include/svx/svdview.hxx
@@ -146,7 +146,7 @@ public:
 };
 
 
-class SVX_DLLPUBLIC SdrView : public SdrCreateView, public virtual tools::WeakBase
+class SVX_DLLPUBLIC SdrView : public SdrCreateView, public tools::WeakBase
 {
     friend class                SdrPageView;
 
diff --git a/include/tools/weakbase.hxx b/include/tools/weakbase.hxx
index 9fe3f32775c3..fa16edd2f147 100644
--- a/include/tools/weakbase.hxx
+++ b/include/tools/weakbase.hxx
@@ -61,9 +61,10 @@ template< class reference_type >
 inline reference_type * WeakReference< reference_type >::get() const
 {
     auto pWeakBase = mpWeakConnection->mpReference;
-    auto pRet = dynamic_cast<reference_type *>(pWeakBase);
-    assert((pWeakBase && pRet) || (!pWeakBase && !pRet));
-    return pRet;
+    if (!pWeakBase)
+        return nullptr;
+    assert(dynamic_cast<reference_type *>(pWeakBase));
+    return static_cast<reference_type *>(pWeakBase);
 }
 
 template< class reference_type >