interpreter: Add varname as positional arg in dep.get_variable()

docs/markdown/Reference-manual.md

@@ -2678,7 +2678,7 @@ an external dependency with the following methods:
    - includes: any include_directories
    - sources: any compiled or static sources the dependency has
 
- - `get_variable(cmake : str, pkgconfig : str, configtool : str,
+ - `get_variable(varname, cmake : str, pkgconfig : str, configtool : str,
    internal: str, default_value : str, pkgconfig_define : [str, str])`
    *(since 0.51.0)*: a generic variable getter method, which replaces the
    get_*type*_variable methods. This allows one to get the variable
@@ -2686,8 +2686,12 @@ an external dependency with the following methods:
    was found. If default_value is set and the value cannot be gotten
    from the object then default_value is returned, if it is not set
    then an error is raised.
-
    *(since 0.54.0)* added `internal` keyword.
+   *(since 0.58.0)* added `varname` as first positional argument. It is used as
+   default value for `cmake`, `pkgconfig`, `configtool` and `internal` keyword
+   arguments. It is useful in the common case where `pkgconfig` and `internal`
+   use the same variable name, in which case it's easier to write `dep.get_variable('foo')`
+   instead of `dep.get_variable(pkgconfig: 'foo', internal: 'foo')`.
 
 ### `disabler` object
 

docs/markdown/snippets/dep_get_variable.md

@@ -0,0 +1,8 @@
+## `dep.get_variable(varname)`
+
+`dep.get_variable()` now has `varname` as first positional argument.
+It is used as default value for `cmake`, `pkgconfig`, `configtool` and `internal`
+keyword arguments. It is useful in the common case where `pkgconfig` and `internal`
+use the same variable name, in which case it's easier to write `dep.get_variable('foo')`
+instead of `dep.get_variable(pkgconfig: 'foo', internal: 'foo')`.
+

mesonbuild/interpreter.py

@@ -512,10 +512,15 @@ class DependencyHolder(InterpreterObject, ObjectHolder[Dependency]):
         return DependencyHolder(pdep, self.subproject)
 
     @FeatureNew('dep.get_variable', '0.51.0')
-    @noPosargs
+    @typed_pos_args('dep.get_variable', optargs=[str])
     @permittedKwargs({'cmake', 'pkgconfig', 'configtool', 'internal', 'default_value', 'pkgconfig_define'})
     @FeatureNewKwargs('dep.get_variable', '0.54.0', ['internal'])
-    def variable_method(self, args, kwargs):
+    def variable_method(self, args: T.Tuple[T.Optional[str]], kwargs: T.Dict[str, T.Any]) -> str:
+        default_varname = args[0]
+        if default_varname is not None:
+            FeatureNew('0.58.0', 'Positional argument to dep.get_variable()').use(self.subproject)
+            for k in ['cmake', 'pkgconfig', 'configtool', 'internal']:
+                kwargs.setdefault(k, default_varname)
         return self.held_object.get_variable(**kwargs)
 
     @FeatureNew('dep.include_type', '0.52.0')

test cases/common/212 dependency get_variable method/meson.build

@@ -62,3 +62,5 @@ assert(idep.get_variable(pkgconfig : 'foo', cmake : 'foo', configtool : 'foo',
 
 idep = declare_dependency(variables : ['foo=value'])
 assert(idep.get_variable(internal: 'foo') == 'value')
+assert(idep.get_variable('foo') == 'value')
+assert(idep.get_variable('invalid', internal: 'foo') == 'value')