[antlr-interest] AntLR C# target exceptions problem

[Johannes Luber]

> Hi,
> 
> I'm trying to get the C# target to work, only with partial success. I'm
> using VS 2008 SP1 or VS 2005 with AntlrWorks and the runtime from
> DOT-NET-runtime-3.1.2.zip.
> The problem is, that exceptions raised due to invalid input don't
> "bubble up" to my code. I noticed the paragraph "Exceptions not trapped
> in Visual Studio" (see below) on the antlr website.
> I took the test grammar from
> http://www.antlr.org/wiki/pages/viewpage.action?pageId=557075 and used
> the generated parser and lexer. My code looks like this:
> 
> try
> {
> 	ANTLRFileStream fs = new ANTLRFileStream("test.txt");
> 	TestLexer lex = new TestLexer(fs);
> 	CommonTokenStream tokens = new CommonTokenStream(lex);
> 	TestParser parser = new TestParser(tokens);
> 	parser.expr();
> }
> catch (NoViableAltException ex)
> {
> 	MessageBox.Show(ex.Message);
> }
> 
> When I debug this code with VS (debug build) the debugger halts in the
> Lexer with a NoViableAltException, but my code never gets a chance to
> catch this exception, same goes for the release build. I even don't even
> get an exception when no debugger is attached.
> 
> Note that when i do what the entry "Exceptions not trapped in Visual
> Studio" suggests, VS just continues after the exceptions, i.e. ignores
> them, and my code also never has the chance to catch them.
> 
> Any ideas?

Does putting a breakpoint into the catch block work? Otherwise the menu for exceptions offers the options to break when an exception is thrown and if an exception is caught. Furthermore, did you add a messagebox call or console print to check if the catch block is actually executed (in release mode)? Otherwise I can't check things out myself, as my development machine has a display problem and is thus unusable right now.

Johannes
> 
> Thanks and regards
> Jan
> 
> 
> 
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