[Flex-help] multiple scanners, one executable: sometimes it works

[Randy S. <sm...@cs...>]

Hello,

I'm involved with a project in which there are two distinct scanners 
being placed in the same executable.  To avoid naming collisions, etc, 
I'm using the -P option to rename the variables from yy* to something 
different.  For both scanners, flex produces the C code without a 
problem.  However, how well these interact depends on the version of 
flex being used.


When using flex version 2.5.4 (run on a managed CentOS linux system), 
everything works as expected.  Both scanners coexist peacefully.

When using flex version 2.5.31 (run on a SuSE 10.1 linux system),
I get multiply defined symbols when trying to compile the code:

eidd_lex.o:(bss+0x2020): multiple definition of `yytext_ptr'
xrta_lex.o:(bss+0x2020): first defined here

So it seems the problem manifests with a later version of flex, whereas 
the early versions produced no conflicts.

I hunted around a bit and saw some references to the fact that 
'yytext_ptr' could be undef'd, but I couldn't find anything concrete.

Is there a work-around to this problem?  Can anybody shed some light on 
why I am experiencing this and what to do about it?

thanks,
Randy Smith