Merge remote-tracking branch 'origin/topic/robin/interpreter-exceptions'

* origin/topic/robin/interpreter-exceptions:
  Adding test for new error handling.
  Experimental code to better handle interpreter errors.

This seems to work fine and it catches some potentially nasty crashes
so I'm merging it in even though it's not the final word on error
handling yet. #646 tracks the work scheduled for later.

src/Reporter.h

@@ -14,6 +14,22 @@
 
 class Connection;
 class Location;
+class Reporter;
+
+// One cannot raise this exception directly, go through the
+// Reporter's methods instead.
+
+class ReporterException {
+protected:
+	friend class Reporter;
+	ReporterException()	{}
+};
+
+class InterpreterException : public ReporterException {
+protected:
+	friend class Reporter;
+	InterpreterException()	{}
+};
 
 // Check printf-style variadic arguments if we can.
 #if __GNUC__
@@ -49,6 +65,10 @@ public:
 	// reported and always generate a core dump.
 	void FatalErrorWithCore(const char* fmt, ...) FMT_ATTR;
 
+	// Report a runtime error in evaluating a Bro script expression. This
+	// function will not return but raise an InterpreterException.
+	void ExprRuntimeError(const Expr* expr, const char* fmt, ...);
+
 	// Report a traffic weirdness, i.e., an unexpected protocol situation
 	// that may lead to incorrectly processing a connnection.
 	void Weird(const char* name);	// Raises net_weird().
@@ -94,7 +114,9 @@ public:
 	void EndErrorHandler()	{ --in_error_handler; }
 
 private:
-	void DoLog(const char* prefix, EventHandlerPtr event, FILE* out, Connection* conn, val_list* addl, bool location, bool time, const char* fmt, va_list ap);
+	void DoLog(const char* prefix, EventHandlerPtr event, FILE* out,
+		   Connection* conn, val_list* addl, bool location, bool time,
+		   const char* postfix, const char* fmt, va_list ap);
 
 	// The order if addl, name needs to be like that since fmt_name can
 	// contain format specifiers