def _set_old_link_args(self) -> None:
        """Setting linker args for older versions of llvm.

        Old versions of LLVM bring an extra level of insanity with them.
        llvm-config will provide the correct arguments for static linking, but
        not for shared-linking, we have to figure those out ourselves, because
        of course we do.
        """
        if self.static:
            self.link_args = self.get_config_value(
                ['--libs', '--ldflags', '--system-libs'] + list(self.required_modules),
                'link_args')
        else:
            # llvm-config will provide arguments for static linking, so we get
            # to figure out for ourselves what to link with. We'll do that by
            # checking in the directory provided by --libdir for a library
            # called libLLVM-<ver>.(so|dylib|dll)
            libdir = self.get_config_value(['--libdir'], 'link_args')[0]

            expected_name = f'libLLVM-{self.version}'
            re_name = re.compile(fr'{expected_name}.(so|dll|dylib)$')

            for file_ in os.listdir(libdir):
                if re_name.match(file_):
                    self.link_args = [f'-L{libdir}',
                                      '-l{}'.format(os.path.splitext(file_.lstrip('lib'))[0])]
                    break
            else:
                raise DependencyException(
                    'Could not find a dynamically linkable library for LLVM.')
Setting linker args for older versions of llvm.

        Old versions of LLVM bring an extra level of insanity with them.
        llvm-config will provide the correct arguments for static linking, but
        not for shared-linking, we have to figure those out ourselves, because
        of course we do.
        
mesonbuild/dependencies/dev.py