configure.ac: Cygwin now has ncurses not termcap. Use standard logic.

  On 10/25/2018 07:50 PM, Corinna Vinschen wrote:
> On Oct 25 16:30, Pedro Alves wrote:
>> On 10/25/2018 04:01 PM, Joel Sherrill wrote:
>>> On Thu, Oct 25, 2018 at 9:34 AM Pedro Alves <palves@redhat.com> wrote:
>>>
>>>> WDTY by "now"?
>>>>
>>>> I mean Cygwin used to include libtermcap and this built. I updated my
>>> Cygwin this
>>> week and it is no longer there. I wasn't able to figure out when it went
>>> away. libncurses.a
>>> is included and that's suitable.
>>>
>>
>> That's so much clearer.
>>
>>> I cc'ed Corinna. I assume she can speak to when libtermcap.a was removed.
> 
> I have no idea, ages ago.  libncurses is used for a long time.  Cygwin
> should use the same autoconf code to figure out the correct lib as any
> other target.

Thanks, I've added info the commit log and applied the patch, as below.

From c1230d1bab8e36e1aa40f3bbadcef9b5d9ddc041 Mon Sep 17 00:00:00 2001
From: Joel Sherrill <joel@rtems.org>
Date: Tue, 30 Oct 2018 16:41:12 +0000
Subject: [PATCH] [src/erc32] Use ncurses instead of termcap on Cygwin too

This removes a Cygwin-specific libtermcap hack that was dependent on
the presence of one of the multiple alternative libraries.  The one it
was hard-coded to pick isn't included with Cygwin anymore.

According to Corinna, libtermcap was removed from Cygwin a long time
ago, and libncurses is used in Cygwin for a long time too.

The fix is to make Cygwin use the same autoconf code to figure out the
correct lib as any other target.

sim/erc32/Changelog:
2018-10-30  Joel Sherrill <joel@rtems.org>

	* configure.ac: Remove the Cygwin-specific libtermcap.a hack
	and use the standard logic to determine which library to use.
	* configure: Regenerate.
---
 sim/erc32/ChangeLog    |  6 ++++++
 sim/erc32/configure    | 10 +++++-----
 sim/erc32/configure.ac |  9 ++++-----
 3 files changed, 15 insertions(+), 10 deletions(-)
  

Hi Pedro,


I didn't see the patch before, sorry.  I have an additional nit:

On Oct 30 17:28, Pedro Alves wrote:
> On 10/25/2018 07:50 PM, Corinna Vinschen wrote:
> > On Oct 25 16:30, Pedro Alves wrote:
> >> On 10/25/2018 04:01 PM, Joel Sherrill wrote:
> >>> On Thu, Oct 25, 2018 at 9:34 AM Pedro Alves <palves@redhat.com> wrote:
> >>>
> >>>> WDTY by "now"?
> >>>>
> >>>> I mean Cygwin used to include libtermcap and this built. I updated my
> >>> Cygwin this
> >>> week and it is no longer there. I wasn't able to figure out when it went
> >>> away. libncurses.a
> >>> is included and that's suitable.
> >>>
> >>
> >> That's so much clearer.
> >>
> >>> I cc'ed Corinna. I assume she can speak to when libtermcap.a was removed.
> > 
> > I have no idea, ages ago.  libncurses is used for a long time.  Cygwin
> > should use the same autoconf code to figure out the correct lib as any
> > other target.
> 
> Thanks, I've added info the commit log and applied the patch, as below.
> [...]
> diff --git a/sim/erc32/configure.ac b/sim/erc32/configure.ac
> index 3135dc55ec..e4df81989c 100644
> --- a/sim/erc32/configure.ac
> +++ b/sim/erc32/configure.ac
> @@ -26,12 +26,11 @@ AC_CACHE_CHECK([for cygwin], sim_cv_os_cygwin,
>  lose
>  #endif],[sim_cv_os_cygwin=yes],[sim_cv_os_cygwin=no])])
>  
> +# Keep in sync with gdb's configure.ac list.
> +AC_SEARCH_LIBS(tgetent, [termcap tinfo curses ncurses],
> +  [TERMCAP=$ac_cv_search_tgetent], [TERMCAP=""])
>  if test x$sim_cv_os_cygwin = xyes; then
> -  TERMCAP='`if test -r ../../libtermcap/libtermcap.a; then echo ../../libtermcap/libtermcap.a; else echo -ltermcap; fi` -luser32'
> -else
> -  # Keep in sync with gdb's configure.ac list.
> -  AC_SEARCH_LIBS(tgetent, [termcap tinfo curses ncurses],
> -    [TERMCAP=$ac_cv_search_tgetent], [TERMCAP=""])
> +  TERMCAP="${TERMCAP} -luser32"

This entire special code block for Cygwin should go away.  The only
reason to keep it is to add -luser32, but that's default for Cygwin
applications anyway, per the GCC config(*).  The less special cases in
configure, the better, me thinks.


Thanks,
Corinna

(*) https://gcc.gnu.org/git/gitweb.cgi?p=gcc.git;a=blob;f=gcc/config/i386/cygwin.h;h=fd7df56a18a5b44315eaac821f8ef65e41dcca46;hb=HEAD#l92