Re: [Qemu-devel] [PATCH] configure: Define NCURSES_WIDECHAR if we're using curses

[Stefan Weil]

Am 02.06.17 um 16:35 schrieb Peter Maydell:

> We want the wide character functions from the ncurses header.
> Unfortunately it doesn't provide them by default, but only
> if either:
>   * NCURSES_WIDECHAR is defined (for ncurses 20111030 and up)
>   * _XOPEN_SOURCE/_XOPEN_SOURCE_EXTENDED are suitably defined
>
> So far we have been implicitly relying on the latter, because
> for GNU libc when we define _GNU_SOURCE this causes libc
> to define the _XOPEN_SOURCE macros for us. Unfortunately
> this doesn't work on all libcs, because some (like OSX and
> musl libc) do not define _XOPEN_SOURCE when _GNU_SOURCE
> is defined.
>
> We can't fix this by defining _XOPEN_SOURCE ourselves, because
> that also means "and don't provide any functions that aren't in
> that standard", and not all libcs provide any way to override
> that to also get the non-standard functions. In particular
> FreeBSD has no such mechanism, and OSX's _DARWIN_C_SOURCE
> doesn't reenable everything (for instance getpagesize()
> is still not prototyped if _DARWIN_C_SOURCE and _XOPEN_SOURCE
> are both defined).
>
> So we have to define NCURSES_WIDECHAR. (This will only work
> if your ncurses is at least 20111030, as older versions
> don't honour this macro.)


I answer to this very old e-mail because I noticed today that defining 
NCURSES_WIDECHAR does not work with the latest MacOS on M1:

Apple still delivers a curses.h which indicates NCURSES_VERSION "5.7" 
(20081102). It does not know NCURSES_WIDECHAR, but support for curses 
can be enabled with _XOPEN_SOURCE_EXTENDED=1.

I used this patch for git master:

diff --git a/meson.build b/meson.build
index 626cf932c1..513332a76d 100644
--- a/meson.build
+++ b/meson.build
@@ -606,7 +606,7 @@ if have_system and not get_option('curses').disabled()
     endif
   endforeach
   msg = get_option('curses').enabled() ? 'curses library not found' : ''
-  curses_compile_args = ['-DNCURSES_WIDECHAR']
+  curses_compile_args = ['-DNCURSES_WIDECHAR', 
'-D_XOPEN_SOURCE_EXTENDED=1']
   if curses.found()
     if cc.links(curses_test, args: curses_compile_args, dependencies: 
[curses])
       curses = declare_dependency(compile_args: curses_compile_args, 
dependencies: [curses])


Then curses is detected and works when configure is given the right 
PKG_CONFIG_PATH:

PKG_CONFIG_PATH=/opt/homebrew/Library/Homebrew/os/mac/pkgconfig/11 
./configure

Regards

Stefan