Remove cxxopt flags when linting C sources. (#359)

* Remove cxxopt flags when linting C sources.

* Remove leftover debug print.

lint/clang_tidy.bzl

@@ -49,7 +49,7 @@ def _gather_inputs(ctx, compilation_context, srcs):
         inputs.append(ctx.files._global_config[0])
     return inputs
 
-def _toolchain_flags(ctx, action_name = ACTION_NAMES.cpp_compile):
+def _toolchain_flags(ctx, user_flags, action_name = ACTION_NAMES.cpp_compile):
     cc_toolchain = find_cpp_toolchain(ctx)
     feature_configuration = cc_common.configure_features(
         ctx = ctx,
@@ -58,7 +58,7 @@ def _toolchain_flags(ctx, action_name = ACTION_NAMES.cpp_compile):
     compile_variables = cc_common.create_compile_variables(
         feature_configuration = feature_configuration,
         cc_toolchain = cc_toolchain,
-        user_compile_flags = ctx.fragments.cpp.cxxopts + ctx.fragments.cpp.copts,
+        user_compile_flags = user_flags,
     )
     flags = cc_common.get_memory_inefficient_command_line(
         feature_configuration = feature_configuration,
@@ -200,9 +200,11 @@ def _get_args(ctx, compilation_context, srcs):
     rule_flags = ctx.rule.attr.copts if hasattr(ctx.rule.attr, "copts") else []
     sources_are_cxx = _is_cxx(srcs[0])
     if (sources_are_cxx):
-        args.extend(_safe_flags(ctx, _toolchain_flags(ctx, ACTION_NAMES.cpp_compile) + rule_flags) + ["-xc++"])
+        user_flags = ctx.fragments.cpp.cxxopts + ctx.fragments.cpp.copts
+        args.extend(_safe_flags(ctx, _toolchain_flags(ctx, user_flags, ACTION_NAMES.cpp_compile) + rule_flags) + ["-xc++"])
     else:
-        args.extend(_safe_flags(ctx, _toolchain_flags(ctx, ACTION_NAMES.c_compile) + rule_flags) + ["-xc"])
+        user_flags = ctx.fragments.cpp.copts
+        args.extend(_safe_flags(ctx, _toolchain_flags(ctx, user_flags, ACTION_NAMES.c_compile) + rule_flags) + ["-xc"])
 
     # add defines
     for define in compilation_context.defines.to_list():