[PATCH] build: make meson-buildoptions.sh stable

[Paolo Bonzini <pbonzini@redhat.com>]

The library directory can change depending on the multilib setup of the host.
It would be even better to detect it in configure with the same algorithm
that Meson uses, but the important thing to avoid confusing developers is
to have identical contents of scripts/meson-buildoptions.sh, independent
of the distro and architecture on which it was created.

So, for now just give a custom default value to libdir.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
---
 scripts/meson-buildoptions.py | 7 +++++--
 scripts/meson-buildoptions.sh | 2 +-
 2 files changed, 6 insertions(+), 3 deletions(-)

diff --git a/scripts/meson-buildoptions.py b/scripts/meson-buildoptions.py
index 3e2b4785388f..a04dcc70a5b7 100755
--- a/scripts/meson-buildoptions.py
+++ b/scripts/meson-buildoptions.py
@@ -61,7 +61,10 @@
 
 # Convert the default value of an option to the string used in
 # the help message
-def value_to_help(value):
+def get_help(opt):
+    if opt["name"] == "libdir":
+        return 'system default'
+    value = opt["value"]
     if isinstance(value, list):
         return ",".join(value)
     if isinstance(value, bool):
@@ -88,7 +91,7 @@ def sh_print(line=""):
 def help_line(left, opt, indent, long):
     right = f'{opt["description"]}'
     if long:
-        value = value_to_help(opt["value"])
+        value = get_help(opt)
         if value != "auto" and value != "":
             right += f" [{value}]"
     if "choices" in opt and long:
diff --git a/scripts/meson-buildoptions.sh b/scripts/meson-buildoptions.sh
index 0f71e92dcba6..d663c9cadfbe 100644
--- a/scripts/meson-buildoptions.sh
+++ b/scripts/meson-buildoptions.sh
@@ -49,7 +49,7 @@ meson_options_help() {
   printf "%s\n" '  --includedir=VALUE       Header file directory [include]'
   printf "%s\n" '  --interp-prefix=VALUE    where to find shared libraries etc., use %M for'
   printf "%s\n" '                           cpu name [/usr/gnemul/qemu-%M]'
-  printf "%s\n" '  --libdir=VALUE           Library directory [lib64]'
+  printf "%s\n" '  --libdir=VALUE           Library directory [system default]'
   printf "%s\n" '  --libexecdir=VALUE       Library executable directory [libexec]'
   printf "%s\n" '  --localedir=VALUE        Locale data directory [share/locale]'
   printf "%s\n" '  --localstatedir=VALUE    Localstate data directory [/var/local]'
-- 
2.38.1