Remove some no-longer-relevant "supports X" features.

All versions of Xcode/Swift that we care about now support the `-fsystem-module` flag, library evolution, and `@_implementationOnly import`. PiperOrigin-RevId: 474139874
bazelbuild · Sep 13, 2022 · c2099d6 · c2099d6
1 parent 0a1d9f8
commit c2099d6
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Showing 5 changed files with 8 additions and 86 deletions.
diff --git a/swift/internal/compiling.bzl b/swift/internal/compiling.bzl
@@ -35,7 +35,6 @@ load(
     "SWIFT_FEATURE_NO_GENERATED_MODULE_MAP",
     "SWIFT_FEATURE_OPT",
     "SWIFT_FEATURE_OPT_USES_WMO",
-    "SWIFT_FEATURE_SUPPORTS_LIBRARY_EVOLUTION",
     "SWIFT_FEATURE_SYSTEM_MODULE",
     "SWIFT_FEATURE_USE_EXPLICIT_SWIFT_MODULE_MAP",
     "SWIFT_FEATURE__NUM_THREADS_1_IN_SWIFTCOPTS",
@@ -835,12 +834,9 @@ def _declare_compile_outputs(
         "{}.swiftsourceinfo".format(module_name),
     )
 
-    if are_all_features_enabled(
+    if is_feature_enabled(
         feature_configuration = feature_configuration,
-        feature_names = [
-            SWIFT_FEATURE_SUPPORTS_LIBRARY_EVOLUTION,
-            SWIFT_FEATURE_EMIT_SWIFTINTERFACE,
-        ],
+        feature_name = SWIFT_FEATURE_EMIT_SWIFTINTERFACE,
     ):
         swiftinterface_file = actions.declare_file(
             "{}.swiftinterface".format(module_name),

diff --git a/swift/internal/feature_names.bzl b/swift/internal/feature_names.bzl
@@ -78,14 +78,6 @@ SWIFT_FEATURE_LAYERING_CHECK_SWIFT = "swift.layering_check_swift"
 # If enabled, the C or Objective-C target should be compiled as a system module.
 SWIFT_FEATURE_SYSTEM_MODULE = "swift.system_module"
 
-# If enabled, the `-Xcc -fsystem-module` flag will be passed when compiling a
-# system C/Objective-C module (with feature `swift.system_module`) because the
-# compiler is new enough to honor it correctly. If disabled, we attempt to mimic
-# this by disabling certain warnings; however, this unfortunately causes `UInt`
-# APIs to be imported by ClangImporter as `UInt` instead of `Int` because
-# ClangImporter doesn't recognize them as true system modules.
-SWIFT_FEATURE_SUPPORTS_SYSTEM_MODULE_FLAG = "swift.supports_system_module_flag"
-
 # If enabled, Swift compilation actions will use batch mode by passing
 # `-enable-batch-mode` to `swiftc`. This is a new compilation mode as of
 # Swift 4.2 that is intended to speed up non-incremental non-WMO builds by
@@ -176,10 +168,6 @@ SWIFT_FEATURE_USE_RESPONSE_FILES = "swift.use_response_files"
 #     target.swift-extra-clang-flags
 SWIFT_FEATURE_CACHEABLE_SWIFTMODULES = "swift.cacheable_swiftmodules"
 
-# If enabled, enables features that require the library evolution compilation
-# mode. If disabled, features that require library evolution mode are noops.
-SWIFT_FEATURE_SUPPORTS_LIBRARY_EVOLUTION = "swift.supports_library_evolution"
-
 # If enabled, requests the `-enable-library-evolution` swiftc flag which is
 # required for newer features like swiftinterface file generation. If the
 # `SWIFT_FEATURES_SUPPORTS_LIBRARY_EVOLUTION` feature is not enabled, this
@@ -191,11 +179,6 @@ SWIFT_FEATURE_ENABLE_LIBRARY_EVOLUTION = "swift.enable_library_evolution"
 # enabled, this feature is a noop.
 SWIFT_FEATURE_EMIT_SWIFTINTERFACE = "swift.emit_swiftinterface"
 
-# If enabled, the toolchain supports private deps (implementation-only imports).
-# This allows Bazel to avoid propagating swiftmodules of such dependencies
-# higher in the dependency graph than they need to be.
-SWIFT_FEATURE_SUPPORTS_PRIVATE_DEPS = "swift.supports_private_deps"
-
 # If enabled, the .swiftmodule file for the affected target will not be
 # embedded in debug info and propagated to the linker.
 #

diff --git a/swift/swift_library.bzl b/swift/swift_library.bzl
@@ -31,7 +31,6 @@ load(
     "@build_bazel_rules_swift//swift/internal:feature_names.bzl",
     "SWIFT_FEATURE_EMIT_SWIFTINTERFACE",
     "SWIFT_FEATURE_ENABLE_LIBRARY_EVOLUTION",
-    "SWIFT_FEATURE_SUPPORTS_PRIVATE_DEPS",
 )
 load(
     "@build_bazel_rules_swift//swift/internal:linking.bzl",
@@ -140,28 +139,9 @@ def _swift_library_impl(ctx):
         unsupported_features = ctx.disabled_features,
     )
 
-    if swift_common.is_enabled(
-        feature_configuration = feature_configuration,
-        feature_name = SWIFT_FEATURE_SUPPORTS_PRIVATE_DEPS,
-    ):
-        # The implicit deps can be added to the private deps; since they are
-        # added to the compilation of every library, they don't need to be
-        # propagated. However, it's not an error to list one of the implicit
-        # deps in "deps", either, so we need to make sure not to pass them in to
-        # `_check_deps_are_disjoint`.
-        deps = ctx.attr.deps
-        private_deps = ctx.attr.private_deps
-        _check_deps_are_disjoint(ctx.label, deps, private_deps)
-    elif ctx.attr.private_deps:
-        fail(
-            ("In target '{}', 'private_deps' cannot be used because this " +
-             "version of the Swift toolchain does not support " +
-             "implementation-only imports.").format(ctx.label),
-            attr = "private_deps",
-        )
-    else:
-        deps = ctx.attr.deps
-        private_deps = []
+    deps = ctx.attr.deps
+    private_deps = ctx.attr.private_deps
+    _check_deps_are_disjoint(ctx.label, deps, private_deps)
 
     swift_infos = get_providers(deps, SwiftInfo)
     private_swift_infos = get_providers(private_deps, SwiftInfo)

diff --git a/swift/toolchains/config/compile_config.bzl b/swift/toolchains/config/compile_config.bzl
@@ -45,8 +45,6 @@ load(
     "SWIFT_FEATURE_OPT_USES_OSIZE",
     "SWIFT_FEATURE_OPT_USES_WMO",
     "SWIFT_FEATURE_REWRITE_GENERATED_HEADER",
-    "SWIFT_FEATURE_SUPPORTS_LIBRARY_EVOLUTION",
-    "SWIFT_FEATURE_SUPPORTS_SYSTEM_MODULE_FLAG",
     "SWIFT_FEATURE_SYSTEM_MODULE",
     "SWIFT_FEATURE_USE_C_MODULES",
     "SWIFT_FEATURE_USE_EXPLICIT_SWIFT_MODULE_MAP",
@@ -162,18 +160,12 @@ def compile_action_configs(
                 SWIFT_ACTION_COMPILE,
             ],
             configurators = [add_arg("-enable-library-evolution")],
-            features = [
-                SWIFT_FEATURE_SUPPORTS_LIBRARY_EVOLUTION,
-                SWIFT_FEATURE_ENABLE_LIBRARY_EVOLUTION,
-            ],
+            features = [SWIFT_FEATURE_ENABLE_LIBRARY_EVOLUTION],
         ),
         ActionConfigInfo(
             actions = [SWIFT_ACTION_COMPILE],
             configurators = [_emit_module_interface_path_configurator],
-            features = [
-                SWIFT_FEATURE_SUPPORTS_LIBRARY_EVOLUTION,
-                SWIFT_FEATURE_EMIT_SWIFTINTERFACE,
-            ],
+            features = [SWIFT_FEATURE_EMIT_SWIFTINTERFACE],
         ),
         ActionConfigInfo(
             actions = [SWIFT_ACTION_COMPILE],
@@ -456,23 +448,6 @@ def compile_action_configs(
             features = [SWIFT_FEATURE_LAYERING_CHECK],
             not_features = [SWIFT_FEATURE_SYSTEM_MODULE],
         ),
-        ActionConfigInfo(
-            actions = [SWIFT_ACTION_PRECOMPILE_C_MODULE],
-            configurators = [
-                # Before Swift 5.4, ClangImporter doesn't currently handle the
-                # IsSystem bit correctly for the input file and ignores the
-                # `-fsystem-module` flag, which causes the module map to be
-                # treated as a user input. We can work around this by disabling
-                # diagnostics for system modules. However, this also disables
-                # behavior in ClangImporter that causes system APIs that use
-                # `UInt` to be imported to use `Int` instead. The only solution
-                # here is to use Xcode 12.5 or higher.
-                add_arg("-Xcc", "-w"),
-                add_arg("-Xcc", "-Wno-nullability-declspec"),
-            ],
-            features = [SWIFT_FEATURE_SYSTEM_MODULE],
-            not_features = [SWIFT_FEATURE_SUPPORTS_SYSTEM_MODULE_FLAG],
-        ),
         ActionConfigInfo(
             actions = [SWIFT_ACTION_PRECOMPILE_C_MODULE],
             configurators = [
@@ -492,10 +467,7 @@ def compile_action_configs(
                 add_arg("-Xcc", "-Xclang"),
                 add_arg("-Xcc", "-fsystem-module"),
             ],
-            features = [
-                SWIFT_FEATURE_SUPPORTS_SYSTEM_MODULE_FLAG,
-                SWIFT_FEATURE_SYSTEM_MODULE,
-            ],
+            features = [SWIFT_FEATURE_SYSTEM_MODULE],
         ),
     ]
 

diff --git a/swift/toolchains/xcode_swift_toolchain.bzl b/swift/toolchains/xcode_swift_toolchain.bzl
@@ -44,9 +44,6 @@ load(
     "SWIFT_FEATURE_DEBUG_PREFIX_MAP",
     "SWIFT_FEATURE_ENABLE_BATCH_MODE",
     "SWIFT_FEATURE_MODULE_MAP_HOME_IS_CWD",
-    "SWIFT_FEATURE_SUPPORTS_LIBRARY_EVOLUTION",
-    "SWIFT_FEATURE_SUPPORTS_PRIVATE_DEPS",
-    "SWIFT_FEATURE_SUPPORTS_SYSTEM_MODULE_FLAG",
     "SWIFT_FEATURE_USE_RESPONSE_FILES",
 )
 load(
@@ -731,14 +728,8 @@ def _xcode_swift_toolchain_impl(ctx):
         SWIFT_FEATURE_ENABLE_BATCH_MODE,
         SWIFT_FEATURE_USE_RESPONSE_FILES,
         SWIFT_FEATURE_DEBUG_PREFIX_MAP,
-        SWIFT_FEATURE_SUPPORTS_LIBRARY_EVOLUTION,
-        SWIFT_FEATURE_SUPPORTS_PRIVATE_DEPS,
     ])
 
-    # Xcode 12.5 implies Swift 5.4.
-    if _is_xcode_at_least_version(xcode_config, "12.5"):
-        requested_features.append(SWIFT_FEATURE_SUPPORTS_SYSTEM_MODULE_FLAG)
-
     env = _xcode_env(target_triple = target_triple, xcode_config = xcode_config)
     execution_requirements = xcode_config.execution_info()
     generated_header_rewriter = resolve_optional_tool(