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
+}

src/InconsistencyException.h

@@ -0,0 +1,68 @@
+//
+//  InconsistencyException.h
+//  
+//
+//  Created by Paul Licameli on 11/27/16.
+//
+//  Some errors that formerly were assertion violations now throw exceptions,
+//  even in production code.  These may be violations of function preconditions
+//  or the results of logical errors internal to functions.  These conditions
+//  are supposed to be deducible statically as never happening.
+//
+
+#ifndef __AUDACITY_INCONSISTENCY_EXCEPTION__
+#define __AUDACITY_INCONSISTENCY_EXCEPTION__
+
+#include "AudacityException.h"
+
+class InconsistencyException final : public MessageBoxException
+{
+public:
+   InconsistencyException() {}
+
+   explicit InconsistencyException
+      ( const char *fn, const char *f, unsigned l )
+         : func { fn }, file { f }, line { l }
+   {}
+
+   InconsistencyException(InconsistencyException&& that)
+      : MessageBoxException(std::move(that))
+   {}
+   InconsistencyException &operator = (InconsistencyException &&that)
+   {
+      if (this != &that)
+         operator= (std::move(that));
+      return *this;
+   }
+
+   ~InconsistencyException() override;
+
+private:
+   std::unique_ptr< AudacityException > Move() override;
+
+   // Format a default, internationalized error message for this exception.
+   wxString ErrorMessage() const override;
+
+   const char *func {};
+   const char *file {};
+   unsigned line {};
+};
+
+// This macro constructs this exception type, using C++ preprocessor to identify
+// the source code location.
+
+#ifdef __func__
+
+#define CONSTRUCT_INCONSISTENCY_EXCEPTION \
+   InconsistencyException( __func__, __FILE__ , __LINE__ )
+
+#else
+
+#define CONSTRUCT_INCONSISTENCY_EXCEPTION \
+   InconsistencyException( "", __FILE__ , __LINE__ )
+
+#endif
+
+#define THROW_INCONSISTENCY_EXCEPTION throw CONSTRUCT_INCONSISTENCY_EXCEPTION
+
+#endif

src/Makefile.am

@@ -146,6 +146,8 @@ audacity_SOURCES = \
 	HistoryWindow.h \
 	ImageManipulation.cpp \
 	ImageManipulation.h \
+	InconsistencyException.cpp \
+	InconsistencyException.h \
 	InterpolateAudio.cpp \
 	InterpolateAudio.h \
 	LabelDialog.cpp \