Define an AudacityException subclass for assertion violations

src/InconsistencyException.cpp

@@ -0,0 +1,42 @@
+//
+//  InconsistencyException.cpp
+//  
+//
+//  Created by Paul Licameli on 11/27/16.
+//
+//
+
+#include "Audacity.h"
+#include "InconsistencyException.h"
+
+InconsistencyException::~InconsistencyException()
+{
+}
+
+std::unique_ptr< AudacityException > InconsistencyException::Move()
+{
+   return std::unique_ptr< AudacityException >
+   { safenew InconsistencyException{ std::move( *this ) } };
+}
+
+wxString InconsistencyException::ErrorMessage() const
+{
+   // Shorten the path
+   wxString path { file };
+   auto sub = wxString{ wxFILE_SEP_PATH } + "src" + wxFILE_SEP_PATH;
+   auto index = path.Find(sub);
+   if (index != wxNOT_FOUND)
+      path = path.Mid(index + sub.size());
+
+#ifdef __func__
+   return wxString::Format(
+_("Internal error in %s at %s line %d.\nPlease inform the Audacity team at feedback@audacityteam.org."),
+      func, path, line
+   );
+#else
+   return wxString::Format(
+_("Internal error at %s line %d.\nPlease inform the Audacity team at feedback@audacityteam.org."),
+      path, line
+   );
+#endif
+}