Use cpp fragment, instead of objc fragment, to determine whether to generate dsym

The information is identical, and we would like to migrate all uses to
cpp fragment so that we can delete the info in objc fragment.

PiperOrigin-RevId: 370899517

Author: googlewalt

swift/internal/features.bzl

@@ -105,7 +105,7 @@ def configure_features(
         _enabled_features = requestable_features,
     )
 
-def features_for_build_modes(ctx, objc_fragment = None):
+def features_for_build_modes(ctx, cpp_fragment = None):
     """Returns a list of Swift toolchain features for current build modes.
 
     This function explicitly breaks the "don't pass `ctx` as an argument"
@@ -114,7 +114,7 @@ def features_for_build_modes(ctx, objc_fragment = None):
 
     Args:
         ctx: The current rule context.
-        objc_fragment: The Objective-C configuration fragment, if available.
+        cpp_fragment: The Cpp configuration fragment, if available.
 
     Returns:
         A list of Swift toolchain features to enable.
@@ -126,7 +126,7 @@ def features_for_build_modes(ctx, objc_fragment = None):
         features.append(SWIFT_FEATURE_COVERAGE)
     if compilation_mode in ("dbg", "fastbuild"):
         features.append(SWIFT_FEATURE_ENABLE_TESTING)
-    if objc_fragment and objc_fragment.generate_dsym:
+    if cpp_fragment and cpp_fragment.apple_generate_dsym:
         features.append(SWIFT_FEATURE_FULL_DEBUG_INFO)
     return features
 

swift/internal/xcode_swift_toolchain.bzl

@@ -652,7 +652,7 @@ def _xcode_swift_toolchain_impl(ctx):
     # version.
     requested_features = features_for_build_modes(
         ctx,
-        objc_fragment = ctx.fragments.objc,
+        cpp_fragment = ctx.fragments.cpp,
     ) + features_from_swiftcopts(swiftcopts = ctx.fragments.swift.copts())
     requested_features.extend(ctx.features)
     requested_features.append(SWIFT_FEATURE_BUNDLED_XCTESTS)
@@ -813,6 +813,7 @@ for incremental compilation using a persistent mode.
     doc = "Represents a Swift compiler toolchain provided by Xcode.",
     fragments = [
         "apple",
+        "cpp",
         "objc",
         "swift",
     ],