Re: Porting the configure script to C99

Thomas Dickey <[email protected]> Fri, 2 Dec 2022 16:45:19 -0500
Newsgroups	gmane.comp.web.lynx.devel
Message-ID	<[email protected]>
On Fri, Dec 02, 2022 at 04:04:32PM +0100, Florian Weimer wrote:
> We're trying to build Fedora with a strict(er) C99 compiler:
> 
>   <https://fedoraproject.org/wiki/Changes/PortingToModernC>
>   <https://fedoraproject.org/wiki/Toolchain/PortingToModernC>
> 
> Testing I dentified a couple of issues in the lynx configure script
> (version 2.9.0dev.10 I believe):
> 
> diff --git a/aclocal.m4 b/aclocal.m4
> index 70cde243d2129cc0..bf2cbff661de2fe1 100644
> --- a/aclocal.m4
> +++ b/aclocal.m4
> @@ -6435,6 +6435,7 @@ AC_CACHE_CHECK(if we can include termio.h with curses,cf_cv_termio_and_curses,[
>      CPPFLAGS="$CPPFLAGS -DHAVE_CONFIG_H -I. -I${srcdir:-.} -I${srcdir:-.}/src -I${srcdir:-.}/WWW/Library/Implementation"
>      touch lynx_cfg.h
>      AC_TRY_COMPILE([
> +#include <stdio.h>

thanks.

>  #include <$1>
>  #include <termio.h>],
>      [putchar(0x0a)],
> @@ -6455,6 +6456,7 @@ AC_DEFUN([CF_TERMIO_AND_TERMIOS],
>  AC_MSG_CHECKING([termio.h and termios.h])
>  AC_CACHE_VAL(cf_cv_termio_and_termios,[
>      AC_TRY_COMPILE([
> +#include <stdio.h>

ok.

>  #if HAVE_TERMIO_H
>  #include <termio.h>
>  #endif
> diff --git a/configure b/configure
> index 97f6d1d5646d05c5..6db52b514b3b9a3c 100755
> --- a/configure
> +++ b/configure
> @@ -31122,6 +31122,7 @@ else
>  #line 31122 "configure"
>  #include "confdefs.h"
>  
> +#include <stdio.h>
>  #if HAVE_TERMIO_H
>  #include <termio.h>
>  #endif
> @@ -31629,6 +31630,9 @@ else
>  #line 31629 "configure"
>  #include "confdefs.h"
>  /* Thanks to Mike Rendell for this test.  */
> +#if HAVE_UNISTD_H
> +# include <unistd.h>
> +#endif

"middle chunk" is referring to this, I suppose.

AC_INCLUDES_DEFAULT includes a lot of headers, not just this one.

what problem does that #include solve?

>  #include <sys/types.h>
>  #define NGID 256
>  #undef MAX
> @@ -47492,6 +47496,7 @@ else
>  #line 47492 "configure"
>  #include "confdefs.h"
>  
> +#include <stdio.h>

...shouldn't be needed, since both curses.h and slang.h include stdio.h
(LYCurses.h includes one or the other, as well as HTUtils.h)

>  #include <LYCurses.h>
>  #include <termio.h>
>  int
> 
> The middle hunk in the configure patch is fixed in later autoconf
> releases, it's not something that comes from aclocal.m4 or configure.in.
> 
> I'm sharing this here for the benefit of other distributions working on
> similar projects.
> 
> Thanks,
> Florian
> 
> 

-- 
Thomas E. Dickey <[email protected]>
https://invisible-island.net
ftp://ftp.invisible-island.net
signature.asc (application/pgp-signature, 659 B)