changes for picking up well known protos

Add dependency and protoc argument for picking up well known protos
from the //third_party/protobuf repo

1 files changed, 16 insertions, 1 deletions

diff --git a/bazel/generate_cc.bzl b/bazel/generate_cc.bzl
index d49cbe8d72..f3961f0a41 100644
--- a/bazel/generate_cc.bzl
+++ b/bazel/generate_cc.bzl
@@ -31,8 +31,20 @@ def generate_cc_impl(ctx):
   arguments += ["-I{0}={0}".format(include.path) for include in includes]
   arguments += [proto.path for proto in protos]
 
+  # create a list of well known proto files if the argument is non-None
+  well_known_proto_files = []
+  if ctx.attr.well_known_protos:
+    f = ctx.attr.well_known_protos.files.to_list()[0].dirname
+    if f != "external/submodule_protobuf/src/google/protobuf":
+      print("Error: Only @submodule_protobuf//:well_known_protos is supported")
+    else:
+      # f points to "external/submodule_protobuf/src/google/protobuf"
+      # add -I argument to protoc so it knows where to look for the proto files.
+      arguments += ["-I{0}".format(f + "/../..")]
+      well_known_proto_files = [f for f in ctx.attr.well_known_protos.files]
+
   ctx.action(
-      inputs = protos + includes + additional_input,
+      inputs = protos + includes + additional_input + well_known_proto_files,
       outputs = out_files,
       executable = ctx.executable._protoc,
       arguments = arguments,
@@ -56,6 +68,9 @@ generate_cc = rule(
             mandatory = False,
             allow_empty = True,
         ),
+        "well_known_protos" : attr.label(
+            mandatory = False,
+        ),
         "_protoc": attr.label(
             default = Label("//external:protocol_compiler"),
             executable = True,