proto: unify envoy_proto_library/api_proto_library. (#4233)

In the latest iteration of
https://github.com/envoyproxy/envoy/pull/4220, it was necessary to use
PGV constraints on fuzzer inputs. To do this would require PGV
generation in envoy_build_system.bzl.

There is also quite a bit of mess in
how we were doing envoy_proto_library() today. So, this PR allows us to
throw away the custom envoy_proto_library() and benefit from leveraging
a single source of Envoy proto build truth.

Risk level: Low
Testing: bazel test //test/...

Signed-off-by: Harvey Tuch <htuch@google.com>

Mirrored from https://github.com/envoyproxy/envoy @ 28d5f4118d60f828b1453cd8ad25033f2c8e38ab

bazel/api_build_system.bzl

@@ -88,7 +88,16 @@ def api_proto_library_internal(visibility = ["//visibility:private"], **kwargs):
 # gRPC stub generation.
 # TODO(htuch): Automatically generate go_proto_library and go_grpc_library
 # from api_proto_library.
-def api_proto_library(name, visibility = ["//visibility:private"], srcs = [], deps = [], has_services = 0, require_py = 1):
+def api_proto_library(
+        name,
+        visibility = ["//visibility:private"],
+        srcs = [],
+        deps = [],
+        external_proto_deps = [],
+        external_cc_proto_deps = [],
+        has_services = 0,
+        linkstatic = None,
+        require_py = 1):
     # This is now vestigial, since there are no direct consumers in
     # the data plane API. However, we want to maintain native proto_library support
     # in the proto graph to (1) support future C++ use of native rules with
@@ -99,7 +108,7 @@ def api_proto_library(name, visibility = ["//visibility:private"], srcs = [], de
     native.proto_library(
         name = name,
         srcs = srcs,
-        deps = deps + [
+        deps = deps + external_proto_deps + [
             "@com_google_protobuf//:any_proto",
             "@com_google_protobuf//:descriptor_proto",
             "@com_google_protobuf//:duration_proto",
@@ -107,7 +116,6 @@ def api_proto_library(name, visibility = ["//visibility:private"], srcs = [], de
             "@com_google_protobuf//:struct_proto",
             "@com_google_protobuf//:timestamp_proto",
             "@com_google_protobuf//:wrappers_proto",
-            "@googleapis//:api_httpbody_protos_proto",
             "@googleapis//:http_api_protos_proto",
             "@googleapis//:rpc_status_protos_lib",
             "@com_github_gogo_protobuf//:gogo_proto",
@@ -123,8 +131,9 @@ def api_proto_library(name, visibility = ["//visibility:private"], srcs = [], de
     pgv_cc_proto_library(
         name = _Suffix(name, _CC_SUFFIX),
         srcs = srcs,
+        linkstatic = linkstatic,
         deps = [_LibrarySuffix(d, _CC_SUFFIX) for d in deps],
-        external_deps = [
+        external_deps = external_cc_proto_deps + [
             "@com_google_protobuf//:cc_wkt_protos",
             "@googleapis//:http_api_protos",
             "@googleapis//:rpc_status_protos",
@@ -132,8 +141,19 @@ def api_proto_library(name, visibility = ["//visibility:private"], srcs = [], de
         ],
         visibility = ["//visibility:public"],
     )
+    py_export_suffixes = []
     if (require_py == 1):
         api_py_proto_library(name, srcs, deps, has_services)
+        py_export_suffixes = ["_py", "_py_genproto"]
+
+    # Allow unlimited visibility for consumers
+    export_suffixes = ["", "_cc", "_cc_validate", "_cc_proto", "_cc_proto_genproto"] + py_export_suffixes
+    for s in export_suffixes:
+        native.alias(
+            name = name + "_export" + s,
+            actual = name + s,
+            visibility = ["//visibility:public"],
+        )
 
 def api_cc_test(name, srcs, proto_deps):
     native.cc_test(