Hi Simon,
so many thanks for your help :).
On Sun, Dec 08, 2019 at 11:31:52PM +0100, Simon Richter wrote:
> On 08.12.19 19:46, Ervin Hegedüs wrote:
>
> > I'ld like to control this feature through my code. I realized
> > that this option set a variable in generated source file:
> >
> > 1577 extern int yy_flex_debug;
> > 1578 int yy_flex_debug = 1;
> >
> > if (argc > 1) {
> > if (strcmp(argv[1], "debug") == 0) {
> > yyset_debug(1);
> > }
> > ...
> >
> > but has no effect (if I use "flex" command without "-d").
> >
> > What am I missing?
>
> The variable is initialized to 1 by default. If you want to leave the
> debug code in but disable it at runtime, your logic needs to set it to 0
> if no "debug" option was given.
ah, cool - now it works!
> Debug output from flex is usually not that useful to anyone not directly
> working on the parser, so the setting is seldom changed at runtime, and
> making it default-on if the debug code was generated allows people to
> add debug output to an existing program without changing other code,
> just by recompiling the lexer.
yes, I think it's clear for me - I'ld like to implement a parser
which will be a part of an API, and would like to give some help
the (API) users to get some debug information.
Many thanks again for your help,
regards,
a.
