[ObjC] make the bazel build always use generated WKTs.

This is done in basically the same way the C++ does this.

It was tested locally be putting `#error` directives in the pre-generated
sources and running the bazel build (it worked).

PiperOrigin-RevId: 509261352

objectivec/BUILD.bazel

@@ -7,9 +7,11 @@ load(":defs.bzl", "objc_proto_camel_case_name")
 # The WKTs have to be checked in to support the CocoaPods and Xcode builds. This
 # generule and test ensure the source are current.
 #
-# TODO: Improve the bazel build so it uses these generated headers so it is
-# always current, and only the builds that can't easily build protoc and
-# generate the files rely on the checked in ones.
+# Within the ":objectivec" target, the outputs of the genrule are then used to
+# ensure they are always "current". This implementation is basically the same
+# has how the WKTs are handled in src/google/protobuf/BUILD.bazel for the C++
+# version. They share the potential downsides around layer checks and that
+# someone could #include the header with the `wkt/` prefix on the name.
 
 _WELL_KNOWN_TYPES = [
     "any",
@@ -59,16 +61,6 @@ staleness_test(
 objc_library(
     name = "objectivec",
     hdrs = [
-        "GPBAny.pbobjc.h",
-        "GPBApi.pbobjc.h",
-        "GPBDuration.pbobjc.h",
-        "GPBEmpty.pbobjc.h",
-        "GPBFieldMask.pbobjc.h",
-        "GPBSourceContext.pbobjc.h",
-        "GPBStruct.pbobjc.h",
-        "GPBTimestamp.pbobjc.h",
-        "GPBType.pbobjc.h",
-        "GPBWrappers.pbobjc.h",
         "GPBArray.h",
         "GPBBootstrap.h",
         "GPBCodedInputStream.h",
@@ -109,39 +101,30 @@ objc_library(
         "GPBUnknownFieldSet_PackagePrivate.h",
         "GPBUnknownField_PackagePrivate.h",
         "GPBUtilities_PackagePrivate.h",
-    ],
+    ] + ["wkt/GPB" + wkt + ".pbobjc.h" for wkt in _OBJC_WKT_NAMES],
     copts = [
         "-Wno-vla",
     ],
     includes = [
         ".",
+        "wkt",
     ],
     non_arc_srcs = [
-        "GPBAny.pbobjc.m",
-        "GPBApi.pbobjc.m",
         "GPBArray.m",
         "GPBCodedInputStream.m",
         "GPBCodedOutputStream.m",
         "GPBDescriptor.m",
         "GPBDictionary.m",
-        "GPBDuration.pbobjc.m",
-        "GPBEmpty.pbobjc.m",
         "GPBExtensionInternals.m",
         "GPBExtensionRegistry.m",
-        "GPBFieldMask.pbobjc.m",
         "GPBMessage.m",
         "GPBRootObject.m",
-        "GPBSourceContext.pbobjc.m",
-        "GPBStruct.pbobjc.m",
-        "GPBTimestamp.pbobjc.m",
-        "GPBType.pbobjc.m",
         "GPBUnknownField.m",
         "GPBUnknownFieldSet.m",
         "GPBUtilities.m",
         "GPBWellKnownTypes.m",
         "GPBWireFormat.m",
-        "GPBWrappers.pbobjc.m",
-    ],
+    ] + ["wkt/GPB" + wkt + ".pbobjc.m" for wkt in _OBJC_WKT_NAMES],
     target_compatible_with = select({
         "@platforms//os:macos": [],
         "@platforms//os:ios": [],
@@ -159,8 +142,8 @@ objc_library(
 conformance_test(
     name = "conformance_test",
     failure_list = "//conformance:failure_list_objc.txt",
-    testee = "//conformance:conformance_objc",
     target_compatible_with = ["@platforms//os:macos"],
+    testee = "//conformance:conformance_objc",
 )
 
 # -------------------------------------------------------------------