bug#8844: flex header file

[Stefano Lattarini]

[adding bug-automake, so that we won't forgot about this report]

On Monday 13 June 2011, Pippijn van Steenhoven wrote:
> Hi,
> 
> in some of my projects, I use (reentrant) flex with the header-file
> option. This causes flex to generate a .h file in addition to the usual
> lex.yy.c file. However, ylwrap doesn't know about this. What would be the
> correct way to use flex with header files?
>
I see two ways out, not mutually exclusive:

 1. Introduce a new automake option `no-ylwrap', instructing automake not
    to use ylwrap to process Yacc and Lex files; this should assume that
    bison and flex can be used, so that we know no problem with concurrent
    make will arise (we can use the `--output' option for both tools).
    Then you can manually add some rules about the header on your
    Makefile.am, without ylwrap getting in your way.

 2. Improve ylwrap and automake Lex support to recognize the `--header'
    Lex option, similarly to what is done for the `-d' Yacc option, and
    emit code handling the header creation, dependencies, etc.

Regards,
  Stefano