Rather than creating stubs for every command that just return
QERR_UNSUPPORTED, use 'if' conditions in the QAPI schema  to
fully exclude generation of the commands on other UNIX.

The command will be rejected at QMP dispatch time instead,
avoiding reimplementing rejection by blocking the stub commands.
This changes the error message for affected commands from

    {"class": "CommandNotFound", "desc": "Command FOO has been disabled"}

to

    {"class": "CommandNotFound", "desc": "The command FOO has not been found"}

This has the additional benefit that the QGA protocol reference
now documents what conditions enable use of the command.

Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Reviewed-by: Konstantin Kostiuk <kkostiuk@redhat.com>
Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
---
 meson.build          | 1 +
 qga/commands-posix.c | 8 --------
 qga/qapi-schema.json | 3 ++-
 3 files changed, 3 insertions(+), 9 deletions(-)

diff --git a/meson.build b/meson.build
index 3f125d1b02..efc47612a3 100644
--- a/meson.build
+++ b/meson.build
@@ -2275,6 +2275,7 @@ config_host_data.set('CONFIG_ATTR', libattr.found())
 config_host_data.set('CONFIG_BDRV_WHITELIST_TOOLS', get_option('block_drv_whitelist_in_tools'))
 config_host_data.set('CONFIG_BRLAPI', brlapi.found())
 config_host_data.set('CONFIG_BSD', host_os in bsd_oses)
+config_host_data.set('CONFIG_FREEBSD', host_os == 'freebsd')
 config_host_data.set('CONFIG_CAPSTONE', capstone.found())
 config_host_data.set('CONFIG_COCOA', cocoa.found())
 config_host_data.set('CONFIG_DARWIN', host_os == 'darwin')
diff --git a/qga/commands-posix.c b/qga/commands-posix.c
index a353f64ae6..f4104f2760 100644
--- a/qga/commands-posix.c
+++ b/qga/commands-posix.c
@@ -877,14 +877,6 @@ void qmp_guest_set_user_password(const char *username,
         return;
     }
 }
-#else /* __linux__ || __FreeBSD__ */
-void qmp_guest_set_user_password(const char *username,
-                                 const char *password,
-                                 bool crypted,
-                                 Error **errp)
-{
-    error_setg(errp, QERR_UNSUPPORTED);
-}
 #endif /* __linux__ || __FreeBSD__ */
 
 #ifdef HAVE_GETIFADDRS
diff --git a/qga/qapi-schema.json b/qga/qapi-schema.json
index 0662a68c43..c763163fcd 100644
--- a/qga/qapi-schema.json
+++ b/qga/qapi-schema.json
@@ -1109,7 +1109,8 @@
 # Since: 2.3
 ##
 { 'command': 'guest-set-user-password',
-  'data': { 'username': 'str', 'password': 'str', 'crypted': 'bool' } }
+  'data': { 'username': 'str', 'password': 'str', 'crypted': 'bool' },
+  'if': { 'any': [ 'CONFIG_WIN32', 'CONFIG_LINUX', 'CONFIG_FREEBSD'] } }
 
 ##
 # @GuestMemoryBlock:
-- 
2.45.1