Re: [Flex-devel] GCC warning comparing signed and unsigned and possible bug

[Timothy A. <tim...@co...>]

On Thu, 2016-09-15 at 05:17 -0400, Will Estes wrote:
> Which version of flex are you using? Looks like you've got an old
> version from the filenames you reference.

Version 2.6.0. The filenames are from a zipped copy of the source I
downloaded from sourceforges cvs system, they should be the latest
possible versions.

> 
> On Thursday, 15 September 2016, 11:10 am +1000, Timothy Arceri <timot
> hy....@co...> wrote:
> 
> > 
> > Hi guys,
> > 
> > I'm seeing a GCC waring in the output from lex which seems to be
> > caused
> > by the following line in flex.skl:
> > 
> >    YY_INPUT( (&YY_CURRENT_BUFFER_LVALUE-
> > >yy_ch_buf[number_to_move]),
> > 			YY_G(yy_n_chars), num_to_read );
> > 
> > To fix it should be changed to:
> > 
> >    YY_INPUT( (&YY_CURRENT_BUFFER_LVALUE-
> > >yy_ch_buf[number_to_move]),
> > 			YY_G(yy_n_chars), (unsigned) num_to_read );
> > 
> > 
> > Something else I noticed is there are two flex.skl files, the
> > output
> > I'm getting seems to be generated by the one
> > in flex/to.do/unicode/flex.skl where num_to_read is defined as int
> > which is fine. However the one in flex/flex.skl defines num_to_read
> > as yy_size_t which is unsigned which means the while loop while (
> > num_to_read <= 0 ) might not get executed, this looks like a bug.
> > 
> > Tim
> > 
> > 
> > 
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