Address the rest of the feedback

.bazelci/presubmit.yml

@@ -47,11 +47,9 @@ tasks:
     build_flags:
       # Bazel 6.x has dependencies that produce warnings now
       - "--features=-treat_warnings_as_errors"
-      - "--experimental_enable_aspect_hints"
     test_flags:
       # Bazel 6.x has dependencies that produce warnings now
       - "--features=-treat_warnings_as_errors"
-      - "--experimental_enable_aspect_hints"
 
   macos_latest:
     name: "Current LTS"

.bazelrc

@@ -11,6 +11,11 @@ build --macos_minimum_os=13.0
 # dependencies cause us to use a newer version
 build --check_direct_dependencies=off
 
+# This is needed for Bazel 6 compatibility. It is enabled by default in Bazel 7, so
+# TODO: Remove this once we drop Bazel 6 support.
+# See also: https://github.com/bazelbuild/bazel/issues/14327
+build --experimental_enable_aspect_hints
+
 # Make sure no warnings slip into the C++ tools we vendor
 build --features treat_warnings_as_errors
 

swift/internal/compiling.bzl

@@ -1592,8 +1592,6 @@ def _collect_clang_module_inputs(
             # use include scanning from Starlark, we can't compute a more
             # precise input set.
             compilation_context = clang_module.compilation_context
-            if not compilation_context:
-                continue
             transitive_inputs.append(compilation_context.headers)
             transitive_inputs.append(
                 depset(compilation_context.direct_textual_headers),

swift/internal/swift_clang_module_aspect.bzl

@@ -587,9 +587,7 @@ def _handle_module(
         else:
             return []
 
-    compilation_contexts_to_merge_for_compilation = []
-    if compilation_context:
-        compilation_contexts_to_merge_for_compilation.append(compilation_context)
+    compilation_contexts_to_merge_for_compilation = [compilation_context]
 
     # Fold the `strict_includes` from `apple_common.Objc` into the Clang module
     # descriptor in `SwiftInfo` so that the `Objc` provider doesn't have to be