Optimize Bazel external dependencies

This change does the following:

- Always use {,new_}http_archive rather than git_repository
- Make liberal use of strip_prefix
- Clarify licenses() in BUILD files
- On POSIX include headers like a normal C/C++ program

This change accomplishes the following:

- Reduce download size >100MB: The biggest culprit is grpc which has
  tens of thousands of commits in its GitHub repository.

- Reduce disk size >200MB: On disk, grpc takes up 250MB when cloned even
  though the tarball of the git repo is 3.2MB. By never using git
  externals, we save on network.

- Consume less cpu: Cloning git repositories is much slower than
  downloading and extracting a tarball.
Change: 133895791

1 files changed, 31 insertions, 1 deletions

diff --git a/grpc.BUILD b/grpc.BUILD
index c1404b54fb..14e8daff5e 100644
--- a/grpc.BUILD
+++ b/grpc.BUILD
@@ -3,6 +3,7 @@
 # ...with small modifications to fix the build rules for :grpc++_unsecure.
 #
 # TODO(mrry): Upstream these fixes back to the gRPC repository.
+# TODO(jart): Fix nanopb's BUILD file. Fix grpc BUILD file.
 
 # GRPC Bazel BUILD file.
 # This currently builds C, C++ and Objective-C code.
@@ -44,9 +45,26 @@ licenses(["notice"])  # 3-clause BSD
 
 package(default_visibility = ["//visibility:public"])
 
+genrule(
+    name = "pb_h",
+    outs = ["third_party/nanopb/pb.h"],
+    cmd = "echo '#include <pb.h>' >$@",
+    visibility = ["//visibility:private"],
+)
 
+genrule(
+    name = "pb_decode_h",
+    outs = ["third_party/nanopb/pb_decode.h"],
+    cmd = "echo '#include <pb_decode.h>' >$@",
+    visibility = ["//visibility:private"],
+)
 
-
+genrule(
+    name = "pb_encode_h",
+    outs = ["third_party/nanopb/pb_encode.h"],
+    cmd = "echo '#include <pb_encode.h>' >$@",
+    visibility = ["//visibility:private"],
+)
 
 cc_library(
   name = "gpr",
@@ -499,6 +517,9 @@ cc_library(
     "src/core/ext/census/placeholders.c",
     "src/core/ext/census/tracing.c",
     "src/core/plugin_registry/grpc_plugin_registry.c",
+    "third_party/nanopb/pb.h",
+    "third_party/nanopb/pb_decode.h",
+    "third_party/nanopb/pb_encode.h",
   ],
   hdrs = [
     "include/grpc/byte_buffer.h",
@@ -856,6 +877,9 @@ cc_library(
     "src/core/lib/tsi/ssl_transport_security.c",
     "src/core/lib/tsi/transport_security.c",
     "src/core/plugin_registry/grpc_cronet_plugin_registry.c",
+    "third_party/nanopb/pb.h",
+    "third_party/nanopb/pb_decode.h",
+    "third_party/nanopb/pb_encode.h",
   ],
   hdrs = [
     "include/grpc/byte_buffer.h",
@@ -1185,6 +1209,9 @@ cc_library(
     "src/core/ext/census/placeholders.c",
     "src/core/ext/census/tracing.c",
     "src/core/plugin_registry/grpc_unsecure_plugin_registry.c",
+    "third_party/nanopb/pb.h",
+    "third_party/nanopb/pb_decode.h",
+    "third_party/nanopb/pb_encode.h",
   ],
   hdrs = [
     "include/grpc/byte_buffer.h",
@@ -2313,6 +2340,9 @@ objc_library(
     "src/core/ext/census/grpc_filter.h",
     "src/core/ext/census/mlog.h",
     "src/core/ext/census/rpc_metric_id.h",
+    "third_party/nanopb/pb.h",
+    "third_party/nanopb/pb_decode.h",
+    "third_party/nanopb/pb_encode.h",
   ],
   includes = [
     "include",