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>

1 files changed, 61 insertions, 0 deletions

diff --git a/xmloff/source/text/txtprhdl.cxx b/xmloff/source/text/txtprhdl.cxx
index 32644e5f7f1c..2a6e3a32c0d5 100644
--- a/xmloff/source/text/txtprhdl.cxx
+++ b/xmloff/source/text/txtprhdl.cxx
@@ -245,6 +245,8 @@ static SvXMLEnumMapEntry<drawing::TextVerticalAdjust> const pXML_VerticalAlign_E
     { XML_TOKEN_INVALID, drawing::TextVerticalAdjust(0) }
 };
 
+namespace {
+
 class XMLDropCapPropHdl_Impl : public XMLPropertyHandler
 {
 public:
@@ -263,6 +265,8 @@ public:
             const SvXMLUnitConverter& ) const override;
 };
 
+}
+
 bool XMLDropCapPropHdl_Impl::equals(
         const Any& r1,
         const Any& r2 ) const
@@ -295,6 +299,8 @@ bool XMLDropCapPropHdl_Impl::exportXML(
     return false;
 }
 
+namespace {
+
 class XMLOpaquePropHdl_Impl : public XMLPropertyHandler
 {
 public:
@@ -308,6 +314,8 @@ public:
             const SvXMLUnitConverter& ) const override;
 };
 
+}
+
 bool XMLOpaquePropHdl_Impl::importXML(
         const OUString& rStrImpValue,
            Any& rValue,
@@ -339,6 +347,8 @@ bool XMLOpaquePropHdl_Impl::exportXML(
     return true;
 }
 
+namespace {
+
 class XMLContourModePropHdl_Impl : public XMLPropertyHandler
 {
 public:
@@ -352,6 +362,8 @@ public:
             const SvXMLUnitConverter& ) const override;
 };
 
+}
+
 bool XMLContourModePropHdl_Impl::importXML(
         const OUString& rStrImpValue,
            Any& rValue,
@@ -383,6 +395,8 @@ bool XMLContourModePropHdl_Impl::exportXML(
     return true;
 }
 
+namespace {
+
 class XMLParagraphOnlyPropHdl_Impl : public XMLPropertyHandler
 {
 public:
@@ -396,6 +410,8 @@ public:
             const SvXMLUnitConverter& ) const override;
 };
 
+}
+
 bool XMLParagraphOnlyPropHdl_Impl::importXML(
         const OUString& rStrImpValue,
            Any& rValue,
@@ -441,6 +457,8 @@ SvXMLEnumMapEntry<WrapTextMode> const pXML_Wrap_Enum[] =
     { XML_TOKEN_INVALID, WrapTextMode(0) }
 };
 
+namespace {
+
 class XMLWrapPropHdl_Impl : public XMLPropertyHandler
 {
 public:
@@ -454,6 +472,8 @@ public:
             const SvXMLUnitConverter& ) const override;
 };
 
+}
+
 bool XMLWrapPropHdl_Impl::importXML(
         const OUString& rStrImpValue,
            Any& rValue,
@@ -486,6 +506,8 @@ bool XMLWrapPropHdl_Impl::exportXML(
     return bRet;
 }
 
+namespace {
+
 class XMLFrameProtectPropHdl_Impl : public XMLPropertyHandler
 {
     const OUString sVal;
@@ -503,6 +525,8 @@ public:
             const SvXMLUnitConverter& ) const override;
 };
 
+}
+
 bool XMLFrameProtectPropHdl_Impl::importXML(
         const OUString& rStrImpValue,
            Any& rValue,
@@ -661,6 +685,8 @@ bool XMLTextColumnsPropertyHandler::exportXML(
     return false;
 }
 
+namespace {
+
 class XMLHoriMirrorPropHdl_Impl : public XMLPropertyHandler
 {
 public:
@@ -674,6 +700,8 @@ public:
             const SvXMLUnitConverter& ) const override;
 };
 
+}
+
 bool XMLHoriMirrorPropHdl_Impl::importXML(
         const OUString& rStrImpValue,
            Any& rValue,
@@ -701,6 +729,8 @@ bool XMLHoriMirrorPropHdl_Impl::exportXML(
     return false;
 }
 
+namespace {
+
 class XMLGrfMirrorPropHdl_Impl : public XMLPropertyHandler
 {
     const OUString sVal;
@@ -721,6 +751,8 @@ public:
             const SvXMLUnitConverter& ) const override;
 };
 
+}
+
 bool XMLGrfMirrorPropHdl_Impl::importXML(
         const OUString& rStrImpValue,
            Any& rValue,
@@ -795,6 +827,9 @@ SvXMLEnumMapEntry<sal_uInt16> const pXML_Emphasize_Enum[] =
     { XML_ACCENT,   FontEmphasis::ACCENT_ABOVE },
     { XML_TOKEN_INVALID, 0 }
 };
+
+namespace {
+
 class XMLTextEmphasizePropHdl_Impl : public XMLPropertyHandler
 {
 public:
@@ -810,6 +845,8 @@ public:
             const SvXMLUnitConverter& ) const override;
 };
 
+}
+
 bool XMLTextEmphasizePropHdl_Impl::importXML(
         const OUString& rStrImpValue,
            Any& rValue,
@@ -891,6 +928,8 @@ bool XMLTextEmphasizePropHdl_Impl::exportXML(
     return bRet;
 }
 
+namespace {
+
 class XMLTextCombineCharPropHdl_Impl : public XMLPropertyHandler
 {
 public:
@@ -906,6 +945,8 @@ public:
             const SvXMLUnitConverter& ) const override;
 };
 
+}
+
 bool XMLTextCombineCharPropHdl_Impl::importXML(
         const OUString& rStrImpValue,
            Any& rValue,
@@ -930,6 +971,8 @@ bool XMLTextCombineCharPropHdl_Impl::exportXML(
     return (1 == rStrExpValue.getLength());
 }
 
+namespace {
+
 class XMLTextRelWidthHeightPropHdl_Impl : public XMLPropertyHandler
 {
 public:
@@ -945,6 +988,8 @@ public:
             const SvXMLUnitConverter& ) const override;
 };
 
+}
+
 bool XMLTextRelWidthHeightPropHdl_Impl::importXML(
         const OUString& rStrImpValue,
            Any& rValue,
@@ -977,6 +1022,8 @@ bool XMLTextRelWidthHeightPropHdl_Impl::exportXML(
     return bRet;
 }
 
+namespace {
+
 class XMLTextSyncWidthHeightPropHdl_Impl : public XMLPropertyHandler
 {
     const OUString sValue;
@@ -995,6 +1042,8 @@ public:
             const SvXMLUnitConverter& ) const override;
 };
 
+}
+
 bool XMLTextSyncWidthHeightPropHdl_Impl::importXML(
         const OUString& rStrImpValue,
            Any& rValue,
@@ -1020,6 +1069,8 @@ bool XMLTextSyncWidthHeightPropHdl_Impl::exportXML(
     return bRet;
 }
 
+namespace {
+
 class XMLTextRotationAnglePropHdl_Impl : public XMLPropertyHandler
 {
 
@@ -1036,6 +1087,8 @@ public:
             const SvXMLUnitConverter& ) const override;
 };
 
+}
+
 bool XMLTextRotationAnglePropHdl_Impl::importXML(
         const OUString& rStrImpValue,
            Any& rValue,
@@ -1077,6 +1130,8 @@ bool XMLTextRotationAnglePropHdl_Impl::exportXML(
     return bRet;
 }
 
+namespace {
+
 class XMLNumber8OneBasedHdl : public XMLPropertyHandler
 {
 
@@ -1093,6 +1148,8 @@ public:
             const SvXMLUnitConverter& ) const override;
 };
 
+}
+
 bool XMLNumber8OneBasedHdl::importXML(
         const OUString& rStrImpValue,
            Any& rValue,
@@ -1119,6 +1176,8 @@ bool XMLNumber8OneBasedHdl::exportXML(
     return bRet;
 }
 
+namespace {
+
 class XMLGraphicPropertyHandler : public XMLPropertyHandler
 {
 public:
@@ -1139,6 +1198,8 @@ public:
     virtual bool equals(const css::uno::Any& rAny1, const css::uno::Any& rAny2) const override;
 };
 
+}
+
 bool XMLGraphicPropertyHandler::equals(const Any& rAny1, const Any& rAny2) const
 {
     uno::Reference<graphic::XGraphic> xGraphic1;