remove /utf-8 option when /validate-charset- is present

mesonbuild/compilers/mixins/visualstudio.py

@@ -260,7 +260,9 @@ class VisualStudioLikeCompiler(Compiler, metaclass=abc.ABCMeta):
                 continue
             # cl.exe does not allow specifying both, so remove /utf-8 that we
             # added automatically in the case the user overrides it manually.
-            elif i.startswith('/source-charset:') or i.startswith('/execution-charset:'):
+            elif (i.startswith('/source-charset:')
+                    or i.startswith('/execution-charset:')
+                    or i == '/validate-charset-'):
                 try:
                     result.remove('/utf-8')
                 except ValueError:

unittests/internaltests.py

@@ -36,6 +36,7 @@ import mesonbuild.environment
 import mesonbuild.modules.gnome
 from mesonbuild import coredata
 from mesonbuild.compilers.c import ClangCCompiler, GnuCCompiler
+from mesonbuild.compilers.cpp import VisualStudioCPPCompiler
 from mesonbuild.compilers.d import DmdDCompiler
 from mesonbuild.interpreterbase import typed_pos_args, InvalidArguments, ObjectHolder
 from mesonbuild.interpreterbase import typed_pos_args, InvalidArguments, typed_kwargs, ContainerTypeInfo, KwargInfo
@@ -220,6 +221,27 @@ class InternalTests(unittest.TestCase):
         l.append_direct('/libbaz.a')
         self.assertEqual(l, ['-Lfoodir', '-lfoo', '-Lbardir', '-lbar', '-lbar', '/libbaz.a'])
 
+
+    def test_compiler_args_class_visualstudio(self):
+        linker = mesonbuild.linkers.MSVCDynamicLinker(MachineChoice.HOST, [])
+        cc = VisualStudioCPPCompiler([], [], 'fake', MachineChoice.HOST, False, mock.Mock(), 'x64', linker=linker)
+
+        a = cc.compiler_args(cc.get_always_args())
+        self.assertEqual(a.to_native(copy=True), ['/nologo', '/showIncludes', '/utf-8'])
+
+        # Ensure /source-charset: removes /utf-8
+        a.append('/source-charset:utf-8')
+        self.assertEqual(a.to_native(copy=True), ['/nologo', '/showIncludes', '/source-charset:utf-8'])
+
+        # Ensure /execution-charset: removes /utf-8
+        a = cc.compiler_args(cc.get_always_args() + ['/execution-charset:utf-8'])
+        self.assertEqual(a.to_native(copy=True), ['/nologo', '/showIncludes', '/execution-charset:utf-8'])
+
+        # Ensure /validate-charset- removes /utf-8
+        a = cc.compiler_args(cc.get_always_args() + ['/validate-charset-'])
+        self.assertEqual(a.to_native(copy=True), ['/nologo', '/showIncludes', '/validate-charset-'])
+
+
     def test_compiler_args_class_gnuld(self):
         ## Test --start/end-group
         linker = mesonbuild.linkers.GnuBFDDynamicLinker([], MachineChoice.HOST, '-Wl,', [])