Re: [Qemu-devel] [PATCH] configure: Fix curses probe for older ncurses

[Peter Maydell <peter.maydell@linaro.org>]

On 26 November 2017 at 22:13, Brad Smith <brad@comstyle.com> wrote:
> Fix the curses probe with older ncurses (.e.g. 5.7, as used by OpenBSD).
>
> ncurses 5.7 requires _XOPEN_SOURCE_EXTENDED to be defined for WACS_* constants.

ncurses 5.7 was released in 2008 and is now 9 years old. Why
is OpenBSD still using such an ancient version?

> Signed-off-by: Brad Smith <brad@comstyle.com>
>
>
> diff --git a/configure b/configure
> index 0c6e7572db..9715b9c2cc 100755
> --- a/configure
> +++ b/configure
> @@ -3186,7 +3186,7 @@ EOF
>    IFS=:
>    for curses_inc in $curses_inc_list; do
>      # Make sure we get the wide character prototypes
> -    curses_inc="-DNCURSES_WIDECHAR $curses_inc"
> +    curses_inc="-DNCURSES_WIDECHAR -D_XOPEN_SOURCE_EXTENDED $curses_inc"

I'm a bit wary of this because we've found in the past that
defining _XOPEN_* defines breaks compilation with some
C libraries which assume that if you define _XOPEN_whatever
it means "only that X/Open stuff and no OS-specific extras",
and we depend on the OS-specific extras.

That said, I did a test compile on OSX, which was the
one that had trouble previously, so this may be OK. I think
I'd rather leave it until after 2.11 releases, though.

thanks
-- PMM