options: ensure all build keys are changed to host

OptionStore.get_value did not change build keys to host when not
cross-compiling.  get_value_object_and_value_for also didn't when
accessing self.augments.

Make all accessors go through ensure_and_validate_key so that the
conversion is done early.  Otherwise, when "native: true" targets look
up compiler options they do so with the "build.*" name, which does not
exist when not cross compiling.

This removes the distinction between get_value(), meant to be for global
options, and get_value_for() which would be for project-specific options.
While the distinction was added in commit d37d649 ("Make all Meson
level options overridable per subproject.", 2025-02-13), it is not
particularly useful and can be a source of bugs like the one in
test_build_to_host_subproject testcase (corresponding to issue #14869).

Fixes: #14869
Signed-off-by: Paolo Bonzini <[email protected]>

Author: bonzini

mesonbuild/options.py

@@ -844,7 +844,7 @@ def get_pending_value(self, key: T.Union[OptionKey, str], default: T.Optional[El
         return self.pending_options.get(key, default)
 
     def get_value(self, key: T.Union[OptionKey, str]) -> ElementaryOptionValues:
-        return self.get_value_object(key).value
+        return self.get_value_for(key)
 
     def __len__(self) -> int:
         return len(self.options)
@@ -868,6 +868,7 @@ def get_value_object_for(self, key: 'T.Union[OptionKey, str]') -> AnyOptionType:
 
     def get_value_object_and_value_for(self, key: OptionKey) -> T.Tuple[AnyOptionType, ElementaryOptionValues]:
         assert isinstance(key, OptionKey)
+        key = self.ensure_and_validate_key(key)
         vobject = self.get_value_object_for(key)
         computed_value = vobject.value
         if key in self.augments:

unittests/optiontests.py

@@ -246,6 +246,71 @@ def test_augment_set_sub(self):
         self.assertEqual(optstore.get_value_for(name), top_value)
         self.assertEqual(optstore.get_value_for(name, sub_name), set_value)
 
+    def test_build_to_host(self):
+        key = OptionKey('cpp_std')
+        def_value = 'c++98'
+        opt_value = 'c++17'
+        optstore = OptionStore(False)
+        co = UserComboOption(key.name,
+                             'C++ language standard to use',
+                             def_value,
+                             choices=['c++98', 'c++11', 'c++14', 'c++17', 'c++20', 'c++23'],
+                             )
+        optstore.add_compiler_option('cpp', key, co)
+
+        cmd_line = {key: opt_value}
+        optstore.initialize_from_top_level_project_call({}, cmd_line, {})
+        self.assertEqual(optstore.get_value_object_and_value_for(key.as_build())[1], opt_value)
+        self.assertEqual(optstore.get_value(key.as_build()), opt_value)
+        self.assertEqual(optstore.get_value_for(key.as_build()), opt_value)
+
+    def test_build_to_host_subproject(self):
+        key = OptionKey('cpp_std')
+        def_value = 'c++98'
+        opt_value = 'c++17'
+        subp = 'subp'
+        optstore = OptionStore(False)
+        co = UserComboOption(key.name,
+                             'C++ language standard to use',
+                             def_value,
+                             choices=['c++98', 'c++11', 'c++14', 'c++17', 'c++20', 'c++23'],
+                             )
+        optstore.add_compiler_option('cpp', key, co)
+
+        spcall = {key: opt_value}
+        optstore.initialize_from_top_level_project_call({}, {}, {})
+        optstore.initialize_from_subproject_call(subp, spcall, {}, {}, {})
+        self.assertEqual(optstore.get_value_object_and_value_for(key.evolve(subproject=subp,
+                                                                            machine=MachineChoice.BUILD))[1], opt_value)
+        self.assertEqual(optstore.get_value(key.evolve(subproject=subp,
+                                                       machine=MachineChoice.BUILD)), opt_value)
+        self.assertEqual(optstore.get_value_for(key.evolve(subproject=subp,
+                                                           machine=MachineChoice.BUILD)), opt_value)
+
+    def test_build_to_host_cross(self):
+        key = OptionKey('cpp_std')
+        def_value = 'c++98'
+        opt_value = 'c++17'
+        optstore = OptionStore(True)
+        for k in [key, key.as_build()]:
+            co = UserComboOption(key.name,
+                                 'C++ language standard to use',
+                                 def_value,
+                                 choices=['c++98', 'c++11', 'c++14', 'c++17', 'c++20', 'c++23'],
+                                 )
+            optstore.add_compiler_option('cpp', k, co)
+
+        cmd_line = {key: opt_value}
+        optstore.initialize_from_top_level_project_call({}, cmd_line, {})
+        print(optstore.options)
+
+        self.assertEqual(optstore.get_value_object_and_value_for(key)[1], opt_value)
+        self.assertEqual(optstore.get_value_object_and_value_for(key.as_build())[1], def_value)
+        self.assertEqual(optstore.get_value(key), opt_value)
+        self.assertEqual(optstore.get_value(key.as_build()), def_value)
+        self.assertEqual(optstore.get_value_for(key), opt_value)
+        self.assertEqual(optstore.get_value_for(key.as_build()), def_value)
+
     def test_b_default(self):
         optstore = OptionStore(False)
         value = optstore.get_default_for_b_option(OptionKey('b_vscrt'))