Re: [Flex-help] Error changing yylex return.

[Will E. <wes...@gm...>]

What version of flex are you running?

On Tuesday,  1 March 2016, 10:13 pm -0300, "Fabricio S. Paranhos" <fab...@gm...> wrote:

> I did some test to discovery what is going on.
> I forward declared the new yylex inside my main file and everything went 
> OK. For some reason flex is not including the new declaration inside the 
> header file.
> 
> Here some simple example in gist [1]. The file main2.c is main.c after 
> gcc preprocessor "gcc -E"
> 
> The generated header file has the new yylex declaration:
>  >#ifndef yyHEADER_H
>  >#define yyHEADER_H 1
>  >#define yyIN_HEADER 1
>  >
>  >#line 2 "flex.l"
>  >#define YY_DECL double yylex(yyscan_t yyscanner)
>  >
>  >
>  >
>  >#line 11 "lex.yy.h"
> 
> But after passing through compiler preprocessor it's removed, as you can 
> see in the main2.c file, and I have to forward declared the new 
> function. I don't know if this is the correct behavior or is a bug.
> 
> [1] https://gist.github.com/anonymous/ec6d47fe8d7822f0e554
> 
> 
> On 02/29/2016 10:37 PM, Chris verBurg wrote:
> > Hey Fabricio,
> >
> > To first order, your code all looks fine to me.  It seems like your
> > redeclaration is not making it into main.c -- I'd suggest maybe next
> > looking at the generated flex.h and seeing what it's doing with YY_DECL and
> > yylex.  Maybe your %{..%} block has to be moved earlier or later in the
> > first section?
> >
> > -Chris
> >
> >
> >
> > On Mon, Feb 29, 2016 at 2:06 PM, Fabricio S. Paranhos <
> > fab...@gm...> wrote:
> >
> >> Hello,
> >>
> >> I'm trying to change the default return value (int) from yylex to a
> >> structure. According to FLEX manual it's possible to change how yylex is
> >> declared[1]:
> >>
> >>   >This definition may be changed by defining the YY_DECL macro. For
> >>   >example, you could use:
> >>   >
> >>   >         #define YY_DECL float lexscan( a, b ) float a, b;
> >>   >
> >>
> >> In my flex file I declared this way:
> >>
> >>   >#define YY_DECL struct token yylex(yyscan_t yyscanner)
> >>
> >> But after using this macro and compiling the final main program I got
> >> the following GCC error:
> >>
> >>   >main.c: In function ‘main’:
> >>   >main.c:14:7: error: incompatible types when assigning to type ‘struct
> >>   >token’ from type ‘int’
> >>   >   lol = yylex(scanner);
> >>
> >>
> >> Even after changing how yylex is declared the final result didn't
> >> change. After some search on the web I found this[2] stack overflow
> >> question, but I got the same error from GCC...
> >>
> >> Anybody can help?
> >>
> >> Here are some additional info:
> >> OS:   Debian 8 64bit
> >> GCC:  Debian 4.9.2-10 4.9.2
> >> Flex: 2.5.39
> >>
> >> And here are my source files:
> >> https://gist.github.com/anonymous/49beeae0d85b4a7f91d6
> >>
> >> Thanks in advance.
> >>
> >> [1]
> >> http://flex.sourceforge.net/manual/Generated-Scanner.html#Generated-Scanner
> >> [2]
> >> https://stackoverflow.com/questions/3796598/returning-non-ints-from-yylex
> >> --
> >> Fabrício S. Paranhos
> >>
> >>
> >> ------------------------------------------------------------------------------
> >> Site24x7 APM Insight: Get Deep Visibility into Application Performance
> >> APM + Mobile APM + RUM: Monitor 3 App instances at just $35/Month
> >> Monitor end-to-end web transactions and take corrective actions now
> >> Troubleshoot faster and improve end-user experience. Signup Now!
> >> http://pubads.g.doubleclick.net/gampad/clk?id=272487151&iu=/4140
> >> --
> >> Flex-help mailing list
> >> Fle...@li...
> >> https://lists.sourceforge.net/lists/listinfo/flex-help
> >>
> >
> 
> -- 
> Fabrício S. Paranhos
> 
> ------------------------------------------------------------------------------
> Site24x7 APM Insight: Get Deep Visibility into Application Performance
> APM + Mobile APM + RUM: Monitor 3 App instances at just $35/Month
> Monitor end-to-end web transactions and take corrective actions now
> Troubleshoot faster and improve end-user experience. Signup Now!
> http://pubads.g.doubleclick.net/gampad/clk?id=272487151&iu=/4140
> -- 
> Flex-help mailing list
> Fle...@li...
> https://lists.sourceforge.net/lists/listinfo/flex-help

-- 
Will Estes
Flex Project Maintainer
wes...@gm...
https://github.com/westes/flex