Replace fallthrough comments with new SAL_FALLTHROUGH macro

...which (in LIBO_INTERNAL_ONLY) for Clang expands to [[clang::fallthrough]] in
preparation of enabling -Wimplicit-fallthrough.  (This is only relevant for
C++11, as neither C nor old C++ has a way to annotate intended fallthroughs.)

Could use BOOST_FALLTHROUGH instead of introducing our own SAL_FALLTHROUGH, but
that would require adding back in dependencies on boost_headers to many
libraries where we carefully removed any remaining Boost dependencies only
recently.  (At least make SAL_FALLTHROUGH strictly LIBO_INTERNAL_ONLY, so its
future evolution will not have any impact on the stable URE interface.)  C++17
will have a proper [[fallthroug]], eventually removing the need for a macro
altogether.

(cherry picked from commit 14cd5182c5f64c43581c82db8c958369152226ac)

Change-Id: I342a7610a107db7d7a344ea9cbddfd9714d7e9ca

8 files changed, 17 insertions, 15 deletions

diff --git a/filter/source/flash/swfwriter1.cxx b/filter/source/flash/swfwriter1.cxx
index 93dfe76f645b..112173ba0e90 100644
--- a/filter/source/flash/swfwriter1.cxx
+++ b/filter/source/flash/swfwriter1.cxx
@@ -1766,6 +1766,7 @@ void Writer::Impl_writeActions( const GDIMetaFile& rMtf )
             {
                 const MetaISectRectClipRegionAction* pA = static_cast<const MetaISectRectClipRegionAction*>(pAction);
                 clipRect = pA->GetRect();
+                SAL_FALLTHROUGH;
             }
             // fall-through
             case( MetaActionType::CLIPREGION ):
@@ -1779,6 +1780,7 @@ void Writer::Impl_writeActions( const GDIMetaFile& rMtf )
             case( MetaActionType::MAPMODE ):
             {
                 bMap++;
+                SAL_FALLTHROUGH;
             }
             // fall-through
             case( MetaActionType::REFPOINT ):
diff --git a/filter/source/graphicfilter/idxf/dxfentrd.cxx b/filter/source/graphicfilter/idxf/dxfentrd.cxx
index 755b9df2bc78..85508ac2d1cc 100644
--- a/filter/source/graphicfilter/idxf/dxfentrd.cxx
+++ b/filter/source/graphicfilter/idxf/dxfentrd.cxx
@@ -699,7 +699,7 @@ void DXFHatchEntity::EvaluateGroup( DXFGroupReader & rDGR )
 
         case 92:
             nCurrentBoundaryPathIndex++;
-            //fallthrough
+            SAL_FALLTHROUGH;
         default:
         {
             bool bExecutingGroupCode = false;
diff --git a/filter/source/graphicfilter/ios2met/ios2met.cxx b/filter/source/graphicfilter/ios2met/ios2met.cxx
index 26b73206ec01..ff578ac5f44a 100644
--- a/filter/source/graphicfilter/ios2met/ios2met.cxx
+++ b/filter/source/graphicfilter/ios2met/ios2met.cxx
@@ -698,11 +698,11 @@ void OS2METReader::SetPen( const Color& rColor, sal_uInt16 nLineWidth, PenStyle
         break;
         case PEN_DASHDOT :
             nDashCount++;
-            //fall-through
+            SAL_FALLTHROUGH;
         case PEN_DOT :
             nDotCount++;
             nDashCount--;
-            //fall-through
+            SAL_FALLTHROUGH;
         case PEN_DASH :
             nDashCount++;
             aLineInfo.SetDotCount( nDotCount );
diff --git a/filter/source/graphicfilter/ipbm/ipbm.cxx b/filter/source/graphicfilter/ipbm/ipbm.cxx
index b54a1f74ad04..c84a60601001 100644
--- a/filter/source/graphicfilter/ipbm/ipbm.cxx
+++ b/filter/source/graphicfilter/ipbm/ipbm.cxx
@@ -155,7 +155,7 @@ bool PBMReader::ImplReadHeader()
     {
         case '1' :
             mbRaw = false;
-            //fall-through
+            SAL_FALLTHROUGH;
         case '4' :
             mnMode = 0;
             nMax = 2;               // number of parameters in Header
@@ -163,14 +163,14 @@ bool PBMReader::ImplReadHeader()
             break;
         case '2' :
             mbRaw = false;
-            //fall-through
+            SAL_FALLTHROUGH;
         case '5' :
             mnMode = 1;
             nMax = 3;
             break;
         case '3' :
             mbRaw = false;
-            //fall-through
+            SAL_FALLTHROUGH;
         case '6' :
             mnMode = 2;
             nMax = 3;
diff --git a/filter/source/graphicfilter/ipsd/ipsd.cxx b/filter/source/graphicfilter/ipsd/ipsd.cxx
index d6213de3be19..3556aa71c6e0 100644
--- a/filter/source/graphicfilter/ipsd/ipsd.cxx
+++ b/filter/source/graphicfilter/ipsd/ipsd.cxx
@@ -241,7 +241,7 @@ bool PSDReader::ImplReadHeader()
         case PSD_DUOTONE :                  // we'll handle the duotone color like a normal grayscale picture
             m_rPSD.SeekRel( nColorLength );
             nColorLength = 0;
-            /* Fall through */
+            SAL_FALLTHROUGH;
         case PSD_GRAYSCALE :
         {
             if ( nColorLength )
diff --git a/filter/source/msfilter/svdfppt.cxx b/filter/source/msfilter/svdfppt.cxx
index 74268e99bd25..a53aa3123649 100644
--- a/filter/source/msfilter/svdfppt.cxx
+++ b/filter/source/msfilter/svdfppt.cxx
@@ -758,11 +758,11 @@ SdrObject* SdrEscherImport::ProcessObj( SvStream& rSt, DffObjData& rObjData, voi
                             switch ( aPlaceholderAtom.nPlaceholderId )
                             {
                                 case PptPlaceholder::MASTERSLIDENUMBER :    nHeaderFooterInstance++;
-                                // fall-through
+                                    SAL_FALLTHROUGH;
                                 case PptPlaceholder::MASTERFOOTER :         nHeaderFooterInstance++;
-                                // fall-through
+                                    SAL_FALLTHROUGH;
                                 case PptPlaceholder::MASTERHEADER :         nHeaderFooterInstance++;
-                                // fall-through
+                                    SAL_FALLTHROUGH;
                                 case PptPlaceholder::MASTERDATE :           nHeaderFooterInstance++; break;
                                 default: break;
 
@@ -6436,13 +6436,13 @@ void PPTFieldEntry::GetDateTime( const sal_uInt32 nVal, SvxDateFormat& eDateForm
         break;
         case 7:
             eDateFormat = SVXDATEFORMAT_A;
-            //fall-through
+            SAL_FALLTHROUGH;
         case 9:
             eTimeFormat = SVXTIMEFORMAT_24_HM;
         break;
         case 8:
             eDateFormat = SVXDATEFORMAT_A;
-            //fall-through
+            SAL_FALLTHROUGH;
         case 11:
             eTimeFormat = SVXTIMEFORMAT_12_HM;
         break;
@@ -6552,7 +6552,7 @@ PPTTextObj::PPTTextObj( SvStream& rIn, SdrPowerPointImport& rSdrPowerPointImport
                 {
                     case PPT_NOTEPAGE :
                         nInstance++;
-                        // fall-through
+                        SAL_FALLTHROUGH;
                     case PPT_MASTERPAGE :
                         nInstance++;
                     case PPT_SLIDEPAGE :
diff --git a/filter/source/msfilter/util.cxx b/filter/source/msfilter/util.cxx
index 687411198c08..673a948b95c5 100644
--- a/filter/source/msfilter/util.cxx
+++ b/filter/source/msfilter/util.cxx
@@ -479,7 +479,7 @@ EquationResult Read_SubF_Combined(WW8ReadFieldParams& rReadParam)
             break;
         }
         (void)rReadParam.SkipToNextToken();
-        // intentional fall-through
+        SAL_FALLTHROUGH;
     case -2:
         {
             if ( rReadParam.GetResult().startsWithIgnoreAsciiCase("(") )
diff --git a/filter/source/svg/svgexport.cxx b/filter/source/svg/svgexport.cxx
index 4c7153221ada..c96981e2abe2 100644
--- a/filter/source/svg/svgexport.cxx
+++ b/filter/source/svg/svgexport.cxx
@@ -2331,7 +2331,7 @@ IMPL_LINK_TYPED( SVGFilter, CalcFieldHdl, EditFieldInfo*, pInfo, void )
                                     aDate.SetDay( i );
                                     sDate += SvxDateField::GetFormatted( aDate, eDateFormat, *pNumberFormatter, eLang );
                                 }
-                                // No break here! We need months too!
+                                SAL_FALLTHROUGH; // We need months too!
                             case SVXDATEFORMAT_C:       // 13.Feb 1996
                             case SVXDATEFORMAT_D:       // 13.February 1996
                                 for( sal_uInt16 i = 1; i <= 12; ++i ) // we get all months in a year