Add tests for std usage. Closes #5097.

run_unittests.py

@@ -5043,6 +5043,14 @@ c = ['{0}']
         # TODO should someday be explicit about build platform only here
         self.init(testdir)
 
+    def test_std_remains(self):
+        # C_std defined in project options must be in effect also when native compiling.
+        testdir = os.path.join(self.unit_test_dir, '50 std remains')
+        self.init(testdir)
+        compdb = self.get_compdb()
+        self.assertRegex(compdb[0]['command'], '-std=c99')
+        self.build()
+
 def should_run_cross_arm_tests():
     return shutil.which('arm-linux-gnueabihf-gcc') and not platform.machine().lower().startswith('arm')
 
@@ -5094,6 +5102,14 @@ class LinuxCrossArmTests(BasePlatformTests):
                 return
         self.assertTrue(False, 'Option libdir not in introspect data.')
 
+    def test_std_remains(self):
+        # C_std defined in project options must be in effect also when cross compiling.
+        testdir = os.path.join(self.unit_test_dir, '50 std remains')
+        self.init(testdir)
+        compdb = self.get_compdb()
+        self.assertRegex(compdb[0]['command'], '-std=c99')
+        self.build()
+
 
 def should_run_cross_mingw_tests():
     return shutil.which('x86_64-w64-mingw32-gcc') and not (is_windows() or is_cygwin())

test cases/unit/50 std remains/meson.build

@@ -0,0 +1,2 @@
+project('std_remains', 'c', default_options: ['c_std=c99'])
+executable('prog', 'prog.c')

test cases/unit/50 std remains/prog.c

@@ -0,0 +1 @@
+int main(int argc, char **argv) { return 0; }