commit 6bb7a8c9a34d805a624b9679b171e11a6d106f09
author Patrick Williams <patrick@stwcx.xyz> Thu Jan 23 13:23:57 2025 -0500
committer Patrick Williams <patrick@stwcx.xyz> Thu Jan 23 14:36:28 2025 -0500
tree 7865017e46f13663166405a35a1e5b4eabbe9ff5
parent 8aea1d814330427a3668b48c347f1703c214748e

sdbus++: remove `PropertiesVariant` for empty properties

A previous commit changed behavior to always add `PropertiesVariant`
even when there were no properties (and to use `variant<monostate>`).
The missing `PropertiesVariant` was used by some other repositories to
detect if an interface had properties or not.  Adding an empty
`PropertiesVariant` breaks this expectation.

Switch back to having no type defined when there are no properties.
Also, move the new `properties_t` over to the common template for
consistency with the `PropertiesVariant` definition and for potential
use elsewhere.

Fixes: 8aea1d814330 ("sdbus++: generate `properties` method for client harness")
Signed-off-by: Patrick Williams <patrick@stwcx.xyz>
Change-Id: I75b36412fe42eb44d5a638c6a8ad7a3ee9b835e3

tools/sdbusplus/templates/interface.client.hpp.mako

diff --git a/tools/sdbusplus/templates/interface.client.hpp.mako b/tools/sdbusplus/templates/interface.client.hpp.mako
index cbc89d2..4943562 100644
--- a/tools/sdbusplus/templates/interface.client.hpp.mako
+++ b/tools/sdbusplus/templates/interface.client.hpp.mako
@@ -49,13 +49,6 @@
     private sdbusplus::async::client::details::client_context_friend
 {
   public:
-    struct properties_t
-    {
-        % for p in interface.properties:
-        ${p.cppTypeParam(interface.name)} ${p.snake_case}${p.default_value(interface.name)};
-        % endfor
-    };
-
     friend Client;
     template <typename, typename>
     friend struct sdbusplus::client::${interface.cppNamespacedClass()};
@@ -71,6 +64,7 @@
 ${p.render(loader, "property.client.hpp.mako", property=p, interface=interface)}
     % endfor
 
+    % if interface.properties:
     auto properties()
     {
         return proxy.template get_all_properties<PropertiesVariant>(context()) |
@@ -104,6 +98,7 @@
                    return result;
                });
     }
+    % endif
 
   private:
     // Conversion constructor from proxy used by client_t.

tools/sdbusplus/templates/interface.common.hpp.mako

diff --git a/tools/sdbusplus/templates/interface.common.hpp.mako b/tools/sdbusplus/templates/interface.common.hpp.mako
index a26f404..0c14038 100644
--- a/tools/sdbusplus/templates/interface.common.hpp.mako
+++ b/tools/sdbusplus/templates/interface.common.hpp.mako
@@ -32,10 +32,15 @@
     % endfor
 
     % if interface.properties:
+    struct properties_t
+    {
+        % for p in interface.properties:
+        ${p.cppTypeParam(interface.name)} ${p.snake_case}${p.default_value(interface.name)};
+        % endfor
+    };
+
     using PropertiesVariant = sdbusplus::utility::dedup_variant_t<
         ${",\n        ".join(sorted(setOfPropertyTypes()))}>;
-    % else:
-    using PropertiesVariant = std::variant<std::monostate>;
     % endif \
 
     % for p in interface.paths: