Switch to Protobuf 21.12 (#27)

Inlining the protobufs in
#25
unblocked migrating to newer version of Protobuf
as the proto compiler (protoc) error'd.

BUILD

@@ -62,8 +62,12 @@ sh_library(
     name = "gen_lib",
     srcs = ["gen.sh"],
     data = [
+        # We should switch to well_known_type_protos after moving to 22.X
+        # but we also need a dependency on descriptor_proto_srcs here.
+        # We cannot on 21.12 as there were some inconsistencies with the rules:
+        # https://github.com/protocolbuffers/protobuf/issues/11430
         "@com_google_protobuf//:well_known_protos",
-        "@com_google_protobuf//:conformance_proto",
+        "@com_google_protobuf//conformance:conformance_proto",
         "@com_google_protobuf//:test_messages_proto3_proto",
         "@com_google_protobuf//:test_messages_proto2_proto",
         "@com_google_protobuf//:protoc",

WORKSPACE

@@ -15,13 +15,13 @@ go_rules_dependencies()
 
 go_register_toolchains(version = "1.20.5")
 
-PBV = "3.20.3"
+PBV = "21.12"
 
 http_archive(
     name = "com_google_protobuf",
-    sha256 = "04e1ed9664d1325b43723b6a62a4a41bf6b2b90ac72b5daee288365aad0ea47d",
+    sha256 = "6a31b662deaeb0ac35e6287bda2f3369b19836e6c9f8828d4da444346f420298",
     strip_prefix = "protobuf-" + PBV,
-    urls = ["https://github.com/protocolbuffers/protobuf/archive/v" + PBV + ".zip"],
+    urls = ["https://github.com/protocolbuffers/protobuf/archive/refs/tags/v" + PBV + ".zip"],
 )
 
 load("@com_google_protobuf//:protobuf_deps.bzl", "protobuf_deps")

gen.sh

@@ -30,19 +30,25 @@ PROTOC=`readlink $PROTOC`
 echo protoc path: $PROTOC
 $PROTOC --version
 
+# For some reason, test_messages_proto{2,3}.proto are in virtual_imports,
+# despite an explicit dependency on those in the BUILD file :'-(
+# TODO: We should figure out a better way of handling this.
+cp external/com_google_protobuf/_virtual_imports/test_messages_proto2_proto/google/protobuf/test_messages_proto2.proto external/com_google_protobuf/src/google/protobuf/test_messages_proto2.proto
+cp external/com_google_protobuf/_virtual_imports/test_messages_proto3_proto/google/protobuf/test_messages_proto3.proto external/com_google_protobuf/src/google/protobuf/test_messages_proto3.proto
+
 PBS=`find . -name '*.proto' | grep -v _virtual_imports`
 
+ARGS="-I external/com_google_protobuf/src -I ./"
+
 echo
 echo generating hacklang...
 for SRC in $PBS
 do
   echo source: $SRC
-  ARGS="-I external/com_google_protobuf/src -I ./"
   $PROTOC $ARGS --plugin=$GENHACK --hack_out="plugin=grpc,allow_proto2_dangerous:$TMP" --experimental_allow_proto3_optional $SRC
   echo
 done
 
-ARGS="-I external/com_google_protobuf/src -I ./"
 $PROTOC $ARGS --encode=foo.bar.example1  ./test/example1.proto < ./test/example1.pb.txt > $TMP/test/example1.pb.bin
 $PROTOC $ARGS --encode=baz.optional_proto3  ./test/optional_proto3.proto < ./test/empty_optional_proto3.pb.txt > $TMP/test/empty_optional_proto3.pb.bin
 $PROTOC $ARGS --encode=baz.optional_proto3  ./test/optional_proto3.proto < ./test/default_optional_proto3.pb.txt > $TMP/test/default_optional_proto3.pb.bin