bazel: Add envoy_mobile_extra_swift_sources repository (#1661)

Desscription: This can be used to attach extra source files to the main swift_library
target, which is useful for including private additions.

Signed-off-by: Keith Smiley <keithbsmiley@gmail.com>
Signed-off-by: JP Simard <jp@jpsim.com>

mobile/bazel/envoy_mobile_dependencies.bzl

@@ -10,7 +10,24 @@ load("@rules_proto_grpc//java:repositories.bzl", rules_proto_grpc_java_repos = "
 load("@rules_python//python:pip.bzl", "pip_install")
 load("@robolectric//bazel:robolectric.bzl", "robolectric_repositories")
 
+def _default_extra_swift_sources_impl(ctx):
+    ctx.file("WORKSPACE", "")
+    ctx.file("empty.swift", "")
+    ctx.file("BUILD.bazel", """
+filegroup(
+    name = "extra_swift_srcs",
+    srcs = ["empty.swift"],
+    visibility = ["//visibility:public"],
+)""")
+
+_default_extra_swift_sources = repository_rule(
+    implementation = _default_extra_swift_sources_impl,
+)
+
 def envoy_mobile_dependencies():
+    if not native.existing_rule("envoy_mobile_extra_swift_sources"):
+        _default_extra_swift_sources(name = "envoy_mobile_extra_swift_sources")
+
     swift_dependencies()
     kotlin_dependencies()
     python_dependencies()

mobile/library/swift/BUILD

@@ -41,7 +41,7 @@ swift_library(
         "grpc/*.swift",
         "mocks/*.swift",
         "stats/*.swift",
-    ]),
+    ]) + ["@envoy_mobile_extra_swift_sources//:extra_swift_srcs"],
     features = ["swift.enable_library_evolution"],
     module_name = "Envoy",
     private_deps = ["//library/objective-c:envoy_engine_objc_lib"],