[antlr-interest] C++ Crash in consumeUntil()

[Andrew Bell]

Hi,

I am throwing a SemanticException in a parser action.  It gets caught
by the default handler which catches the exception as a
RecognitionException.  The exception handler calls reportError() and
then dies when it calls recover().  Here's the stack trace:

#0  0x0000000000523cdd in antlr::TokenBuffer::LA ()
#1  0x000000000043d343 in antlr::Parser::consumeUntil ()
#2  0x00000000004bd227 in StageParser::stagename ()
#3  0x00000000004bd975 in StageParser::stage ()
#4  0x00000000004bdc3c in StageParser::lang ()

Since I didn't build with debug, I don't get all of the inlined code
in the trace.

Anyway, the problem seems to be that recover(), calls consume()
without regard to whether there is anything to consume.  This
condition would be caught by the assert clause in
CircularQueue::removeItems() in debug mode, but the assert is a NOOP
if not build with debug.  I think that part of this problem is that
there is an assumption that if an exception is thrown in an action, no
match has been made.  This is not the case in my circumstance.

Anyway, this seems to be a bug/hard to recognize issue in the C++
runtime.  Does anyone have any ideas on how to best deal with this?

Also, it has been about 7 years since I last used ANTLR and it STILL
doesn't appear have an option to set filename suffixes on generated
files for C++ output.  If I add such, would someone be willing to
accept/integrate?

Thanks in advance,

--
Andrew Bell
andrew.bell.ia at gmail.com