A Flex Bug?

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Article #73474

#73474

From: Ajay Shah
Date: Sat, 14 Sep 1991 01:19

36 lines
1610 bytes

I have encountered what I think is a flex bug.

Consider this lex program:

---------------------------------------------------------------------------
%%
^[ \t]+	|
[ \t]+$	;
---------------------------------------------------------------------------

It can be rewritten without a "|"; one would just say ";"
instead.

Both versions work fine with lex.  The version with the ";" works
with flex but the version with a "|" fails with flex.

The test input which breaks the flex-| version is:

	""

Just to be sure, here is od -cx testfile:

0000000   \t   "   "  \n
	    0922    220a
0000004

What happens when this input is given to the generated scanner:
it hangs, while eating CPU.

Looks like a bug to me...

-- 
_______________________________________________________________________________
Ajay Shah, (213)734-3930, ajayshah@usc.edu
                             The more things change, the more they stay insane.
_______________________________________________________________________________

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From: ajayshah@alhena.usc.edu (Ajay Shah)
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Subject: A Flex Bug?
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