stack overflow in match.c

[andrewchambers]

Steps to reproduce:

checkout https://github.com/andrewchambers/qc/tree/ec59bd4fa3384eca2b78a577a06955d5a472c3c9
run mbld

ac@black:~/src/qc$ mbld
project base /home/ac/src/qc:
qc...
    6m  ctypes.myr 
    6m  err.myr 
    6m  ast.myr 
    6m  fold.myr 
    6m  hideset.myr 
    6m  tok.myr 
    6m  cpp.myr 
CRASH: "6m cpp.myr"

stack trace says match.c:236:acceptall() is getting into an infinite recursion causing a stack overflow.
The repeating pattern in recursion is about 3 calls deep before looping.

The offending line of code is https://github.com/andrewchambers/qc/blob/ec59bd4fa3384eca2b78a577a06955d5a472c3c9/tok.myr#L22

commenting out the hs struct member in the tok type resolves the infinite loop.

[oridb]

Fixed -- there was a loop being generated in pattern matching because the start state was added to the list of end states.