Workaround a gcc warning for switch() { case X: return ...; } constructs

Fixes warnings like the following one with gcc 9.3 ``` /home/even/qgis/qgis/src/gui/qgsfilecontentsourcelineedit.cpp: In member function ‘virtual QString QgsPictureSourceLineEditBase::fileFilter() const’: /home/even/qgis/qgis/src/gui/qgsfilecontentsourcelineedit.cpp:307:1: warning: control reaches end of non-void function [-Wreturn-type] 307 | } | ^ ```
qgis · May 11, 2021 · a11baa0 · a11baa0
1 parent 26a09f6
commit a11baa0
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diff --git a/python/core/auto_generated/qgis.sip.in b/python/core/auto_generated/qgis.sip.in
@@ -334,6 +334,7 @@ typedef unsigned long long qgssize;
 
 
 
+
 QString geoWkt();
 %Docstring
 Wkt string that represents a geographic coord sys

diff --git a/src/core/qgis.h b/src/core/qgis.h
@@ -864,6 +864,26 @@ typedef unsigned long long qgssize;
 #define FINAL final
 #endif
 
+#ifndef SIP_RUN
+#if defined(__GNUC__) && !defined(__clang__)
+// Workaround a GCC bug where a -Wreturn-type warning is emitted in constructs
+// like:
+// switch( mVariableThatCanOnlyBeXorY )
+// {
+//    case X:
+//        return "foo";
+//    case Y:
+//        return "foo";
+// }
+// See https://gcc.gnu.org/bugzilla/show_bug.cgi?id=87951
+#define DEFAULT_BUILTIN_UNREACHABLE \
+  default: \
+  __builtin_unreachable();
+#else
+#define DEFAULT_BUILTIN_UNREACHABLE
+#endif
+#endif // SIP_RUN
+
 #ifdef SIP_RUN
 
 /**

diff --git a/src/gui/qgsfilecontentsourcelineedit.cpp b/src/gui/qgsfilecontentsourcelineedit.cpp
@@ -289,20 +289,24 @@ QgsMessageBar *QgsAbstractFileContentSourceLineEdit::messageBar() const
 
 ///@cond PRIVATE
 
+
 QString QgsPictureSourceLineEditBase::fileFilter() const
 {
   switch ( mFormat )
   {
     case Svg:
       return tr( "SVG files" ) + " (*.svg)";
     case Image:
+    {
       QStringList formatsFilter;
       const QByteArrayList supportedFormats = QImageReader::supportedImageFormats();
       for ( const auto &format : supportedFormats )
       {
         formatsFilter.append( QString( QStringLiteral( "*.%1" ) ).arg( QString( format ) ) );
       }
       return QString( "%1 (%2);;%3 (*.*)" ).arg( tr( "Images" ), formatsFilter.join( QStringLiteral( " " ) ), tr( "All files" ) );
+    }
+    DEFAULT_BUILTIN_UNREACHABLE
   }
 }
 
@@ -313,7 +317,11 @@ QString QgsPictureSourceLineEditBase::selectFileTitle() const
     case Svg:
       return tr( "Select SVG File" );
     case Image:
+    {
       return tr( "Select Image File" );
+    }
+
+    DEFAULT_BUILTIN_UNREACHABLE
   }
 }
 
@@ -324,7 +332,11 @@ QString QgsPictureSourceLineEditBase::fileFromUrlTitle() const
     case Svg:
       return tr( "SVG From URL" );
     case Image:
+    {
       return tr( "Image From URL" );
+    }
+
+    DEFAULT_BUILTIN_UNREACHABLE
   }
 }
 
@@ -335,7 +347,11 @@ QString QgsPictureSourceLineEditBase::fileFromUrlText() const
     case Svg:
       return tr( "Enter SVG URL" );
     case Image:
+    {
       return tr( "Enter image URL" );
+    }
+
+    DEFAULT_BUILTIN_UNREACHABLE
   }
 }
 
@@ -346,7 +362,11 @@ QString QgsPictureSourceLineEditBase::embedFileTitle() const
     case Svg:
       return tr( "Embed SVG File" );
     case Image:
+    {
       return tr( "Embed Image File" );
+    }
+
+    DEFAULT_BUILTIN_UNREACHABLE
   }
 }
 
@@ -357,7 +377,11 @@ QString QgsPictureSourceLineEditBase::extractFileTitle() const
     case Svg:
       return tr( "Extract SVG File" );
     case Image:
+    {
       return tr( "Extract Image File" );
+    }
+
+    DEFAULT_BUILTIN_UNREACHABLE
   }
 }
 
@@ -368,7 +392,10 @@ QString QgsPictureSourceLineEditBase::defaultSettingsKey() const
     case Svg:
       return QStringLiteral( "/UI/lastSVGDir" );
     case Image:
+    {
       return QStringLiteral( "/UI/lastImageDir" );
+    }
+    DEFAULT_BUILTIN_UNREACHABLE
   }
 }