Extend loplugin:external to warn about classes

...following up on 314f15bff08b76bf96acf99141776ef64d2f1355 "Extend
loplugin:external to warn about enums".

Cases where free functions were moved into an unnamed namespace along with a
class, to not break ADL, are in:

filter/source/svg/svgexport.cxx
sc/source/filter/excel/xelink.cxx
sc/source/filter/excel/xilink.cxx
svx/source/sdr/contact/viewobjectcontactofunocontrol.cxx

All other free functions mentioning moved classes appear to be harmless and not
give rise to (silent, even) ADL breakage.  (One remaining TODO in
compilerplugins/clang/external.cxx is that derived classes are not covered by
computeAffectedTypes, even though they could also be affected by ADL-breakage---
but don't seem to be in any acutal case across the code base.)

For friend declarations using elaborate type specifiers, like

class C1 {};
class C2 { friend class C1; };

* If C2 (but not C1) is moved into an unnamed namespace, the friend declaration
must be changed to not use an elaborate type specifier (i.e., "friend C1;"; see
C++17 [namespace.memdef]/3: "If the name in a friend declaration is neither
qualified nor a template-id and the declaration is a function or an
elaborated-type-specifier, the lookup to determine whether the entity has been
previously declared shall not consider any scopes outside the innermost
enclosing namespace.")

* If C1 (but not C2) is moved into an unnamed namespace, the friend declaration
must be changed too, see <https://gcc.gnu.org/bugzilla/show_bug.cgi?id=71882>
"elaborated-type-specifier friend not looked up in unnamed namespace".

Apart from that, to keep changes simple and mostly mechanical (which should help
avoid regressions), out-of-line definitions of class members have been left in
the enclosing (named) namespace.  But explicit specializations of class
templates had to be moved into the unnamed namespace to appease
<https://gcc.gnu.org/bugzilla/show_bug.cgi?id=92598> "explicit specialization of
template from unnamed namespace using unqualified-id in enclosing namespace".

Also, accompanying declarations (of e.g. typedefs or static variables) that
could arguably be moved into the unnamed namespace too have been left alone.

And in some cases, mention of affected types in blacklists in other loplugins
needed to be adapted.

And sc/qa/unit/mark_test.cxx uses a hack of including other .cxx, one of which
is sc/source/core/data/segmenttree.cxx where e.g. ScFlatUInt16SegmentsImpl is
not moved into an unnamed namespace (because it is declared in
sc/inc/segmenttree.hxx), but its base ScFlatSegmentsImpl is.  GCC warns about
such combinations with enabled-by-default -Wsubobject-linkage, but "The compiler
doesn’t give this warning for types defined in the main .C file, as those are
unlikely to have multiple definitions."
(<https://gcc.gnu.org/onlinedocs/gcc-9.2.0/gcc/Warning-Options.html>)  The
warned-about classes also don't have multiple definitions in the given test, so
disable the warning when including the .cxx.

Change-Id: Ib694094c0d8168be68f8fe90dfd0acbb66a3f1e4
Reviewed-on: https://gerrit.libreoffice.org/83239
Tested-by: Jenkins
Reviewed-by: Stephan Bergmann <sbergman@redhat.com>

6 files changed, 33 insertions, 0 deletions

diff --git a/svx/source/table/svdotable.cxx b/svx/source/table/svdotable.cxx
index b6aede0dd926..68386971fb88 100644
--- a/svx/source/table/svdotable.cxx
+++ b/svx/source/table/svdotable.cxx
@@ -84,6 +84,8 @@ using namespace ::com::sun::star::style;
 
 namespace sdr { namespace table {
 
+namespace {
+
 class TableProperties : public TextProperties
 {
 protected:
@@ -103,6 +105,8 @@ public:
     virtual void ItemChange(const sal_uInt16 nWhich, const SfxPoolItem* pNewItem = nullptr) override;
 };
 
+}
+
 TableProperties::TableProperties(SdrObject& rObj)
 : TextProperties(rObj)
 {
@@ -143,12 +147,16 @@ std::unique_ptr<SfxItemSet> TableProperties::CreateObjectSpecificItemSet(SfxItem
         EE_ITEMS_START, EE_ITEMS_END>{});
 }
 
+namespace {
+
 class TableObjectGeoData : public SdrTextObjGeoData
 {
 public:
     tools::Rectangle   maLogicRect;
 };
 
+}
+
 TableStyleSettings::TableStyleSettings()
 : mbUseFirstRow(true)
 , mbUseLastRow(false)
diff --git a/svx/source/table/tablecontroller.cxx b/svx/source/table/tablecontroller.cxx
index d4c5ab1ad43b..2690e1d5062f 100644
--- a/svx/source/table/tablecontroller.cxx
+++ b/svx/source/table/tablecontroller.cxx
@@ -112,6 +112,8 @@ namespace o3tl
 
 namespace sdr { namespace table {
 
+namespace {
+
 class SvxTableControllerModifyListener : public ::cppu::WeakImplHelper< css::util::XModifyListener >
 {
 public:
@@ -127,6 +129,7 @@ public:
     SvxTableController* mpController;
 };
 
+}
 
 // XModifyListener
 
diff --git a/svx/source/table/tabledesign.cxx b/svx/source/table/tabledesign.cxx
index 0a4f81417f63..c80f4ace3f60 100644
--- a/svx/source/table/tabledesign.cxx
+++ b/svx/source/table/tabledesign.cxx
@@ -67,6 +67,8 @@ typedef std::map< OUString, sal_Int32 > CellStyleNameMap;
 
 typedef ::cppu::WeakComponentImplHelper< XStyle, XNameReplace, XServiceInfo, XIndexAccess, XModifyBroadcaster, XModifyListener > TableDesignStyleBase;
 
+namespace {
+
 class TableDesignStyle : private ::cppu::BaseMutex, public TableDesignStyleBase
 {
 public:
@@ -122,8 +124,12 @@ public:
     Reference< XStyle > maCellStyles[style_count];
 };
 
+}
+
 typedef std::vector< Reference< XStyle > > TableDesignStyleVector;
 
+namespace {
+
 class TableDesignFamily : public ::cppu::WeakImplHelper< XNameContainer, XNamed, XIndexAccess, XSingleServiceFactory,  XServiceInfo, XComponent, XPropertySet >
 {
 public:
@@ -177,6 +183,8 @@ public:
     TableDesignStyleVector  maDesigns;
 };
 
+}
+
 TableDesignStyle::TableDesignStyle()
 : TableDesignStyleBase(m_aMutex)
 {
diff --git a/svx/source/table/tablehandles.cxx b/svx/source/table/tablehandles.cxx
index 776768affc53..abf7c55f85ba 100644
--- a/svx/source/table/tablehandles.cxx
+++ b/svx/source/table/tablehandles.cxx
@@ -41,6 +41,7 @@
 
 namespace sdr { namespace table {
 
+namespace {
 
 class OverlayTableEdge : public sdr::overlay::OverlayObject
 {
@@ -55,6 +56,7 @@ public:
     OverlayTableEdge( const basegfx::B2DPolyPolygon& rPolyPolygon, bool bVisible );
 };
 
+}
 
 TableEdgeHdl::TableEdgeHdl( const Point& rPnt, bool bHorizontal, sal_Int32 nMin, sal_Int32 nMax, sal_Int32 nEdges )
 : SdrHdl( rPnt, SdrHdlKind::User )
diff --git a/svx/source/table/tablertfimporter.cxx b/svx/source/table/tablertfimporter.cxx
index 43b7f44b2e78..267c6a9c6519 100644
--- a/svx/source/table/tablertfimporter.cxx
+++ b/svx/source/table/tablertfimporter.cxx
@@ -49,6 +49,8 @@ using namespace ::com::sun::star::beans;
 
 namespace sdr { namespace table {
 
+namespace {
+
 struct RTFCellDefault
 {
     SfxItemSet          maItemSet;
@@ -59,8 +61,12 @@ struct RTFCellDefault
     explicit RTFCellDefault( SfxItemPool* pPool ) : maItemSet( *pPool ), mnRowSpan(1), mnColSpan(1), mnCellX(0) {}
 };
 
+}
+
 typedef std::vector< std::shared_ptr< RTFCellDefault > > RTFCellDefaultVector;
 
+namespace {
+
 struct RTFCellInfo
 {
     SfxItemSet const    maItemSet;
@@ -73,6 +79,8 @@ struct RTFCellInfo
     explicit RTFCellInfo( SfxItemPool& rPool ) : maItemSet(  rPool ), mnStartPara(0), mnParaCount(0), mnCellX(0), mnRowSpan(1) {}
 };
 
+}
+
 typedef std::shared_ptr< RTFCellInfo > RTFCellInfoPtr;
 typedef std::vector< RTFCellInfoPtr > RTFColumnVector;
 
diff --git a/svx/source/table/viewcontactoftableobj.cxx b/svx/source/table/viewcontactoftableobj.cxx
index 10a6173fab56..3687df3424e9 100644
--- a/svx/source/table/viewcontactoftableobj.cxx
+++ b/svx/source/table/viewcontactoftableobj.cxx
@@ -54,6 +54,8 @@ namespace drawinglayer
 {
     namespace primitive2d
     {
+        namespace {
+
         class SdrCellPrimitive2D : public BufferedDecompositionPrimitive2D
         {
         private:
@@ -85,6 +87,8 @@ namespace drawinglayer
             DeclPrimitive2DIDBlock()
         };
 
+        }
+
         void SdrCellPrimitive2D::create2DDecomposition(Primitive2DContainer& rContainer, const geometry::ViewInformation2D& /*aViewInformation*/) const
         {
             // prepare unit polygon