interpreterobjects: deprecated passing a number to configuration_data.set10

This is currently allowed, and is used in at least a few projects. It
was not intended to work or documented, but it does and since it is in
use a full deprecation period must be used. A warning has also been
added for values < 0, which have surprising behavior.

docs/yaml/objects/cfg_data.yaml

@@ -41,8 +41,17 @@ methods:
       type: str
       description: The name of the variable to set
     value:
-      type: bool
-      description: The value to set as either `1` or `0`
+      type: bool | int
+      description: |
+        The value to set as either `1` or `0`
+
+        Passing numbers was never intended to work, and since 0.62 it has been
+        deprecated. It will be removed in a future version of Meson. If you
+        need to pass numbers use the `.set` method.
+  warnings:
+  - numeric values < 0 have the surprising behavior of being converted to
+    [[true]], values > 1 have the more expected but unintentional behavior of
+    being interpretered as [[true]].
 
   kwargs_inherit: cfg_data.set
 

docs/yaml/objects/feature.yaml

@@ -54,7 +54,7 @@ methods:
     if get_option('directx').require(host_machine.system() == 'windows',
           error_message: 'DirectX only available on Windows').allowed() then
       src += ['directx.c']
-      config.set10('HAVE_DIRECTX', 1)
+      config.set10('HAVE_DIRECTX', true)
     endif
     ```
 

mesonbuild/interpreter/interpreterobjects.py

@@ -320,6 +320,14 @@ class ConfigurationDataHolder(ObjectHolder[build.ConfigurationData], MutableInte
     @typed_kwargs('configuration_data.set10', _CONF_DATA_SET_KWS)
     def set10_method(self, args: T.Tuple[str, T.Union[int, bool]], kwargs: 'kwargs.ConfigurationDataSet') -> None:
         self.__check_used()
+        if isinstance(args[1], int):
+            mlog.deprecation('configuration_data.set10 with number. the `set10` '
+                             'method should only be used with booleans',
+                             location=self.interpreter.current_node)
+            if args[1] < 0:
+                mlog.warning('Passing a number that is less than 0 may not have the intended result, '
+                             'as meson will treat all non-zero values as true.',
+                             location=self.interpreter.current_node)
         self.held_object.values[args[0]] = (int(args[1]), kwargs['description'])
 
     @typed_pos_args('configuration_data.has', (str, int, bool))