New library lib-exceptions

libraries/lib-exceptions/InconsistencyException.h

@@ -0,0 +1,81 @@
+/*!
+  @file InconsistencyException.h
+  @brief MessageBoxException for violation of preconditions or assertions
+
+  Created by Paul Licameli on 11/27/16.
+
+*/
+
+#ifndef __AUDACITY_INCONSISTENCY_EXCEPTION__
+#define __AUDACITY_INCONSISTENCY_EXCEPTION__
+
+#include "AudacityException.h"
+
+//! Exception that should be impossible in production, thrown only from provably unreachable places
+/*!  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.
+ 
+  The error message identifies source file and line number, possibly the function too (depending on
+  the compiler), and suggests that the user inform the development team.
+ */
+class EXCEPTIONS_API InconsistencyException final : public MessageBoxException
+{
+public:
+   InconsistencyException () 
+       : MessageBoxException{ ExceptionType::Internal, XO ("Internal Error") } 
+   {}
+
+   //! Don't call this directly but use @ref CONSTRUCT_INCONSISTENCY_EXCEPTION or @ref THROW_INCONSISTENCY_EXCEPTION
+   explicit InconsistencyException(
+      const char *fn, //!< file name supplied by preprocessor
+      const char *f, //!< function name supplied by preprocessor
+      unsigned l //!< line number supplied by preprocessor
+   )
+       : MessageBoxException { ExceptionType::Internal, XO("Internal Error") }
+       , func { fn }, file { f }, line { l }
+   {}
+
+   InconsistencyException(InconsistencyException&& that)
+      : MessageBoxException(std::move(that))
+      , func{ that.func }
+      , file{ that.file }
+      , line{ that.line }
+   {}
+
+   ~InconsistencyException() override;
+
+   unsigned GetLine() const { return line; }
+
+private:
+   // Format a default, internationalized error message for this exception.
+   TranslatableString ErrorMessage() const override;
+
+   const char *func {};
+   const char *file {};
+   unsigned line {};
+};
+
+#ifdef __func__
+
+#define CONSTRUCT_INCONSISTENCY_EXCEPTION \
+   InconsistencyException( __func__, __FILE__ , __LINE__ )
+
+#else
+
+/*! @def CONSTRUCT_INCONSISTENCY_EXCEPTION
+@brief Construct InconsistencyException, using C++ preprocessor to identify the source code location
+
+For cases where the exception object is not immediately thrown */
+#define CONSTRUCT_INCONSISTENCY_EXCEPTION \
+   InconsistencyException( "", __FILE__ , __LINE__ )
+
+#endif
+
+/*! @def THROW_INCONSISTENCY_EXCEPTION
+@brief Throw InconsistencyException, using C++ preprocessor to identify the source code location
+*/
+#define THROW_INCONSISTENCY_EXCEPTION throw CONSTRUCT_INCONSISTENCY_EXCEPTION
+
+#endif