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>

10 files changed, 38 insertions, 2 deletions

diff --git a/sd/source/filter/eppt/epptso.cxx b/sd/source/filter/eppt/epptso.cxx
index e03db4c9ddd3..1cd19b23c1f8 100644
--- a/sd/source/filter/eppt/epptso.cxx
+++ b/sd/source/filter/eppt/epptso.cxx
@@ -3035,6 +3035,8 @@ void PPTWriter::WriteCString( SvStream& rSt, const OUString& rString, sal_uInt32
     }
 }
 
+namespace {
+
 class ContainerGuard
 {
 private:
@@ -3051,6 +3053,8 @@ public:
     }
 };
 
+}
+
 void PPTWriter::ImplCreateTable( uno::Reference< drawing::XShape > const & rXShape, EscherSolverContainer& aSolverContainer,
                                 EscherPropertyContainer& aPropOpt )
 {
diff --git a/sd/source/filter/eppt/pptx-epptooxml.cxx b/sd/source/filter/eppt/pptx-epptooxml.cxx
index 9ef75df597ad..9789e20a343c 100644
--- a/sd/source/filter/eppt/pptx-epptooxml.cxx
+++ b/sd/source/filter/eppt/pptx-epptooxml.cxx
@@ -152,8 +152,6 @@ enum PPTXLayout
     LAYOUT_SIZE
 };
 
-}
-
 struct PPTXLayoutInfo
 {
     int const nType;
@@ -161,6 +159,8 @@ struct PPTXLayoutInfo
     const char* sType;
 };
 
+}
+
 static const PPTXLayoutInfo aLayoutInfo[LAYOUT_SIZE] =
 {
     { 20, "Blank Slide", "blank" },
diff --git a/sd/source/filter/grf/sdgrffilter.cxx b/sd/source/filter/grf/sdgrffilter.cxx
index d16491dff288..c1f920362b81 100644
--- a/sd/source/filter/grf/sdgrffilter.cxx
+++ b/sd/source/filter/grf/sdgrffilter.cxx
@@ -59,6 +59,8 @@ using namespace ::com::sun::star::ucb;
 using namespace com::sun::star::ui::dialogs;
 using namespace ::sfx2;
 
+namespace {
+
 class SdGRFFilter_ImplInteractionHdl : public ::cppu::WeakImplHelper< css::task::XInteractionHandler >
 {
     css::uno::Reference< css::task::XInteractionHandler > m_xInter;
@@ -76,6 +78,8 @@ class SdGRFFilter_ImplInteractionHdl : public ::cppu::WeakImplHelper< css::task:
     virtual void SAL_CALL   handle( const css::uno::Reference< css::task::XInteractionRequest >& ) override;
 };
 
+}
+
 void SdGRFFilter_ImplInteractionHdl::handle( const css::uno::Reference< css::task::XInteractionRequest >& xRequest )
 {
     if( !m_xInter.is() )
diff --git a/sd/source/filter/html/HtmlOptionsDialog.cxx b/sd/source/filter/html/HtmlOptionsDialog.cxx
index ec523e2c86aa..5db49c2af647 100644
--- a/sd/source/filter/html/HtmlOptionsDialog.cxx
+++ b/sd/source/filter/html/HtmlOptionsDialog.cxx
@@ -38,6 +38,8 @@ using namespace com::sun::star::ui::dialogs;
 #include <pres.hxx>
 #include <sdabstdlg.hxx>
 
+namespace {
+
 class SdHtmlOptionsDialog : public cppu::WeakImplHelper
 <
     XExporter,
@@ -80,6 +82,8 @@ public:
 
 };
 
+}
+
 SdHtmlOptionsDialog::SdHtmlOptionsDialog() :
     meDocType   ( DocumentType::Draw )
 {
diff --git a/sd/source/filter/html/buttonset.cxx b/sd/source/filter/html/buttonset.cxx
index 751e5db0b63f..cb382303287f 100644
--- a/sd/source/filter/html/buttonset.cxx
+++ b/sd/source/filter/html/buttonset.cxx
@@ -45,6 +45,8 @@ using namespace ::com::sun::star::io;
 using namespace ::com::sun::star::beans;
 using namespace ::com::sun::star::lang;
 
+namespace {
+
 class ButtonsImpl
 {
 public:
@@ -60,6 +62,8 @@ private:
     Reference< XStorage > mxStorage;
 };
 
+}
+
 ButtonsImpl::ButtonsImpl( const OUString& rURL )
 {
     try
diff --git a/sd/source/filter/html/htmlex.cxx b/sd/source/filter/html/htmlex.cxx
index ad8e2a97eae6..77189e3d543d 100644
--- a/sd/source/filter/html/htmlex.cxx
+++ b/sd/source/filter/html/htmlex.cxx
@@ -114,6 +114,8 @@ const char * const pButtonNames[] =
 #define BTN_MORE    10
 #define BTN_LESS    11
 
+namespace {
+
 // Helper class for the simple creation of files local/remote
 class EasyFile
 {
@@ -131,6 +133,8 @@ public:
     void      close();
 };
 
+}
+
 // Helper class for the embedding of text attributes into the html output
 class HtmlState
 {
diff --git a/sd/source/filter/html/pubdlg.cxx b/sd/source/filter/html/pubdlg.cxx
index 7623d34a115d..6026e78c67aa 100644
--- a/sd/source/filter/html/pubdlg.cxx
+++ b/sd/source/filter/html/pubdlg.cxx
@@ -335,6 +335,8 @@ SvStream& WriteSdPublishingDesign(SvStream& rOut, const SdPublishingDesign& rDes
     return rOut;
 }
 
+namespace {
+
 // Dialog for the entry of the name of the design
 class SdDesignNameDlg : public weld::GenericDialogController
 {
@@ -348,6 +350,8 @@ public:
     DECL_LINK(ModifyHdl, weld::Entry&, void);
 };
 
+}
+
 // SdPublishingDlg Methods
 
 SdPublishingDlg::SdPublishingDlg(weld::Window* pWindow, DocumentType eDocType)
diff --git a/sd/source/filter/ppt/pptin.cxx b/sd/source/filter/ppt/pptin.cxx
index 89af5b41019c..c2f30fa880e4 100644
--- a/sd/source/filter/ppt/pptin.cxx
+++ b/sd/source/filter/ppt/pptin.cxx
@@ -1475,12 +1475,16 @@ void ImplSdPPTImport::SetHeaderFooterPageSettings( SdPage* pPage, const PptSlide
     }
 }
 
+namespace {
+
 // Import of pages
 struct Ppt97AnimationStlSortHelper
 {
     bool operator()( const std::pair< SdrObject*, Ppt97AnimationPtr >& p1, const std::pair< SdrObject*, Ppt97AnimationPtr >& p2 );
 };
 
+}
+
 bool Ppt97AnimationStlSortHelper::operator()( const std::pair< SdrObject*, Ppt97AnimationPtr >& p1, const std::pair< SdrObject*, Ppt97AnimationPtr >& p2 )
 {
     if( !p1.second.get() || !p2.second.get() )
diff --git a/sd/source/filter/xml/sdtransform.cxx b/sd/source/filter/xml/sdtransform.cxx
index fa0cced78971..586d6ba9dbdc 100644
--- a/sd/source/filter/xml/sdtransform.cxx
+++ b/sd/source/filter/xml/sdtransform.cxx
@@ -34,6 +34,8 @@
 
 using namespace ::com::sun::star::style;
 
+namespace {
+
 class SdTransformOOo2xDocument
 {
 public:
@@ -65,6 +67,8 @@ public:
     SdrOutliner& mrOutliner;
 };
 
+}
+
 /** transforms the given model from OOo 2.x to OOo 3.x. This maps
     the deprecated EE_PARA_BULLETSTATE and clears the EE_PARA_LRSPACE
     if used together with a EE_PARA_NUMBULLET */
diff --git a/sd/source/filter/xml/sdxmlwrp.cxx b/sd/source/filter/xml/sdxmlwrp.cxx
index f23eabd0f6c8..90e0e4f120fa 100644
--- a/sd/source/filter/xml/sdxmlwrp.cxx
+++ b/sd/source/filter/xml/sdxmlwrp.cxx
@@ -126,6 +126,8 @@ char const sXML_import_draw_styles_ooo_service[] = "com.sun.star.comp.Draw.XMLSt
 char const sXML_import_draw_content_ooo_service[] = "com.sun.star.comp.Draw.XMLContentImporter";
 char const sXML_import_draw_settings_ooo_service[] = "com.sun.star.comp.Draw.XMLSettingsImporter";
 
+namespace {
+
 struct XML_SERVICEMAP
 {
     const sal_Char* mpService;
@@ -140,6 +142,8 @@ struct XML_SERVICES
     const sal_Char* mpSettings;
 };
 
+}
+
 static XML_SERVICES const * getServices( bool bImport, bool bDraw, sal_uLong nStoreVer )
 {
     static XML_SERVICES const gServices[] =