Remove the emit_swiftinterface build setting.

This was only present to support Apple framework rules, but its design was flawed, so they no longer use it. Library evolution shouldn't be enabled for entire dependency subgraphs; authors of SDKs should explicitly enable it on their libraries with the `library_evolution` attribute.

PiperOrigin-RevId: 629786303

swift/BUILD

@@ -1,5 +1,4 @@
 load("@bazel_skylib//:bzl_library.bzl", "bzl_library")
-load("@bazel_skylib//rules:common_settings.bzl", "bool_setting")
 load(
     "//swift/internal:build_settings.bzl",
     "per_module_swiftcopt_flag",
@@ -265,13 +264,6 @@ per_module_swiftcopt_flag(
     visibility = ["//visibility:public"],
 )
 
-# Configuration setting for enabling the generation of swiftinterface files.
-bool_setting(
-    name = "emit_swiftinterface",
-    build_setting_default = False,
-    visibility = ["//visibility:public"],
-)
-
 # Allows a user to override the default Swift driver during a build, if the
 # toolchain is using the default.
 label_flag(

swift/internal/attrs.bzl

@@ -51,7 +51,9 @@ indirect (transitive) dependents.
         ),
         # Deprecated, but Starlark rules do not inherit `licenses` by default
         # (see b/169635467).
-        "licenses": attr.license(),  # buildifier: disable=attr-license
+        # buildifier: disable=attr-license
+        # buildifier: disable=attr-licenses
+        "licenses": attr.license(),
     }
 
 def swift_compilation_attrs(
@@ -172,9 +174,6 @@ def swift_config_attrs():
         configuration settings.
     """
     return {
-        "_config_emit_swiftinterface": attr.label(
-            default = "@build_bazel_rules_swift//swift:emit_swiftinterface",
-        ),
         "_per_module_swiftcopt": attr.label(
             default = "@build_bazel_rules_swift//swift:per_module_swiftcopt",
         ),

swift/internal/swift_protoc_gen_aspect.bzl

@@ -15,7 +15,6 @@
 """An aspect attached to `proto_library` targets to generate Swift artifacts."""
 
 load("@bazel_skylib//lib:dicts.bzl", "dicts")
-load("@bazel_skylib//rules:common_settings.bzl", "BuildSettingInfo")
 load(
     "@build_bazel_rules_swift//swift:module_name.bzl",
     "derive_swift_module_name",
@@ -30,8 +29,6 @@ load(":attrs.bzl", "swift_config_attrs")
 load(":compiling.bzl", "compile")
 load(
     ":feature_names.bzl",
-    "SWIFT_FEATURE_EMIT_SWIFTINTERFACE",
-    "SWIFT_FEATURE_ENABLE_LIBRARY_EVOLUTION",
     "SWIFT_FEATURE_ENABLE_TESTING",
     "SWIFT_FEATURE_LAYERING_CHECK_SWIFT",
 )
@@ -236,16 +233,6 @@ def _swift_protoc_gen_aspect_impl(target, aspect_ctx):
 
         extra_features = []
 
-        # This feature is not fully supported because the SwiftProtobuf library
-        # has not yet been designed to fully support library evolution. The
-        # intent of this is to allow users building distributable frameworks to
-        # use Swift protos as an _implementation-only_ detail of their
-        # framework, where those protos would not be exposed to clients in the
-        # API. Rely on it at your own risk.
-        if aspect_ctx.attr._config_emit_swiftinterface[BuildSettingInfo].value:
-            extra_features.append(SWIFT_FEATURE_ENABLE_LIBRARY_EVOLUTION)
-            extra_features.append(SWIFT_FEATURE_EMIT_SWIFTINTERFACE)
-
         # Compile the generated Swift sources and produce a static library and a
         # .swiftmodule as outputs. In addition to the other proto deps, we also
         # pass support libraries like the SwiftProtobuf runtime as deps to the

swift/swift_library.bzl

@@ -16,7 +16,6 @@
 
 load("@bazel_skylib//lib:dicts.bzl", "dicts")
 load("@bazel_skylib//lib:sets.bzl", "sets")
-load("@bazel_skylib//rules:common_settings.bzl", "BuildSettingInfo")
 load(
     "@build_bazel_rules_swift//swift/internal:attrs.bzl",
     "swift_deps_attr",
@@ -140,11 +139,7 @@ def _swift_library_impl(ctx):
 
     extra_features = []
 
-    # TODO(b/239957001): Remove the global flag.
-    if (
-        ctx.attr.library_evolution or
-        ctx.attr._config_emit_swiftinterface[BuildSettingInfo].value
-    ):
+    if ctx.attr.library_evolution:
         extra_features.append(SWIFT_FEATURE_ENABLE_LIBRARY_EVOLUTION)
         extra_features.append(SWIFT_FEATURE_EMIT_SWIFTINTERFACE)