unit tests: Test ObjC and ObjC++ as well as C and C++

This tests ObjC and ObjC++ both with and without C enabled. I did this
because I ran into issues where ObjC only worked when C was enabled, and
then a later bug where C was disabled, due to the fact that C and ObjC
both use `c_std` and not `objc_std`.

test cases/unit/115 c cpp stds/meson.build

@@ -1,6 +1,17 @@
-project('c cpp stds', 'c', 'cpp',
-    default_options: [
-        'c_std=gnu89,c89',
-        'cpp_std=gnu++98,vc++11',
-    ],
+# SPDX-License-Identifier: Apache-2.0
+# Copyright © 2024 Intel Corporation
+
+project(
+  'c cpp stds',
+  default_options: [
+    'c_std=gnu89,c89',
+    'cpp_std=gnu++98,vc++11',
+  ],
 )
+
+if get_option('with-c')
+  add_languages('c', 'cpp', native : false)
+endif
+if get_option('with-objc')
+  add_languages('objc', 'objcpp', native : false)
+endif

test cases/unit/115 c cpp stds/meson.options

@@ -0,0 +1,5 @@
+# SPDX-License-Identifier: Apache-2.0
+# Copyright © 2024 Intel Corporation
+
+option('with-c', type : 'boolean', value : false)
+option('with-objc', type : 'boolean', value : false)

unittests/allplatformstests.py

@@ -5043,9 +5043,11 @@ def test_configure_same_noop(self):
             olddata = newdata
             oldmtime = newmtime
 
-    def test_c_cpp_stds(self) -> None:
+    def __test_multi_stds(self, test_c: bool = True, test_objc: bool = False) -> None:
+        assert test_c or test_objc, 'must test something'
         testdir = os.path.join(self.unit_test_dir, '115 c cpp stds')
-        self.init(testdir)
+        self.init(testdir, extra_args=[f'-Dwith-c={str(test_c).lower()}',
+                                       f'-Dwith-objc={str(test_objc).lower()}'])
         # Invalid values should fail whatever compiler we have
         with self.assertRaises(subprocess.CalledProcessError):
             self.setconf('-Dc_std=invalid')
@@ -5054,7 +5056,19 @@ def test_c_cpp_stds(self) -> None:
         with self.assertRaises(subprocess.CalledProcessError):
             self.setconf('-Dc_std=c++11')
         env = get_fake_env()
-        cc = detect_c_compiler(env, MachineChoice.HOST)
+        if test_c:
+            cc = detect_c_compiler(env, MachineChoice.HOST)
+        if test_objc:
+            objc = detect_compiler_for(env, 'objc', MachineChoice.HOST, True, '')
+            assert objc is not None
+            if test_c and cc.get_argument_syntax() != objc.get_argument_syntax():
+                # The test doesn't work correctly in this case because we can
+                # end up with incompatible stds, like gnu89 with cl.exe for C
+                # and clang.exe for ObjC
+                return
+            if not test_c:
+                cc = objc
+
         if cc.get_id() in {'msvc', 'clang-cl'}:
             # default_option should have selected those
             self.assertEqual(self.getconf('c_std'), 'c89')
@@ -5068,14 +5082,27 @@ def test_c_cpp_stds(self) -> None:
             # The first supported std should be selected
             self.setconf('-Dcpp_std=gnu++11,vc++11,c++11')
             self.assertEqual(self.getconf('cpp_std'), 'vc++11')
-        elif cc.get_id() == 'gcc' or (cc.get_id() == 'clang' and not is_windows()):
+        elif cc.get_id() in {'gcc', 'clang'}:
             # default_option should have selected those
             self.assertEqual(self.getconf('c_std'), 'gnu89')
             self.assertEqual(self.getconf('cpp_std'), 'gnu++98')
             # The first supported std should be selected
             self.setconf('-Dcpp_std=c++11,gnu++11,vc++11')
             self.assertEqual(self.getconf('cpp_std'), 'c++11')
 
+    def test_c_cpp_stds(self) -> None:
+        self.__test_multi_stds()
+
+    @skip_if_not_language('objc')
+    @skip_if_not_language('objcpp')
+    def test_objc_objcpp_stds(self) -> None:
+        self.__test_multi_stds(test_c=False, test_objc=True)
+
+    @skip_if_not_language('objc')
+    @skip_if_not_language('objcpp')
+    def test_c_cpp_objc_objcpp_stds(self) -> None:
+        self.__test_multi_stds(test_objc=True)
+
     def test_rsp_support(self):
         env = get_fake_env()
         cc = detect_c_compiler(env, MachineChoice.HOST)