gn: fix incremental build of descriptor when changing transitive deps
This CL makes it so that GN is aware of the transitive deps of a proto
descriptor rule so that it rebuilds the descriptor when the non-root
files are touched.
We need to wrap protoc because of a bug in protoc where the depfile is
not in the right output format when generating descriptors.
Change-Id: Ib0fb95351849f0ca802e87ea54329430ec6b1ffd
diff --git a/gn/standalone/proto_library.gni b/gn/standalone/proto_library.gni
index 3c73926..f79ae07 100644
--- a/gn/standalone/proto_library.gni
+++ b/gn/standalone/proto_library.gni
@@ -125,9 +125,12 @@
sources = proto_sources
outputs = get_path_info(protogens, "abspath")
+ protoc_script = "//gn/standalone/protoc.py"
protoc_label = "//gn:protoc($host_toolchain)"
protoc_path = get_label_info(protoc_label, "root_out_dir") + "/protoc"
args = [
+ "./" + rebase_path(protoc_script, root_build_dir),
+
# Path should be rebased because |root_build_dir| for current toolchain
# may be different from |root_out_dir| of protoc built on host toolchain.
"./" + rebase_path(protoc_path, root_build_dir),
@@ -141,10 +144,14 @@
]
}
if (generate_descriptor != "") {
+ depfile = "$target_gen_dir/" +
+ rebase_path("$generate_descriptor.d", root_gen_dir)
args += [
"--include_imports",
"--descriptor_set_out",
rebase_path("$root_gen_dir/" + generate_descriptor, root_build_dir),
+ "--dependency_out",
+ rebase_path("$root_gen_dir/$generate_descriptor.d", root_build_dir),
]
}
diff --git a/gn/standalone/protoc.py b/gn/standalone/protoc.py
new file mode 100755
index 0000000..7f83bef
--- /dev/null
+++ b/gn/standalone/protoc.py
@@ -0,0 +1,54 @@
+#!/usr/bin/env python
+# Copyright (C) 2019 The Android Open Source Project
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+# http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+"""Script to wrap protoc execution.
+
+This script exists to work-around the bad depfile generation by protoc when
+generating descriptors."""
+
+from __future__ import print_function
+import argparse
+import os
+import sys
+import subprocess
+import tempfile
+
+def main():
+ parser = argparse.ArgumentParser()
+ parser.add_argument('--descriptor_set_out', default=None)
+ parser.add_argument('--dependency_out', default=None)
+ parser.add_argument('protoc')
+ args, remaining = parser.parse_known_args()
+
+ if args.dependency_out and args.descriptor_set_out:
+ with tempfile.NamedTemporaryFile() as t:
+ custom = [
+ '--descriptor_set_out',
+ args.descriptor_set_out,
+ '--dependency_out',
+ t.name
+ ]
+ subprocess.call([args.protoc] + custom + remaining)
+
+ dependency_data = t.read()
+
+ with open(args.dependency_out, 'w') as f:
+ f.write(args.descriptor_set_out + ":")
+ f.write(dependency_data)
+ else:
+ subprocess.call(sys.argv[1:])
+
+if __name__ == '__main__':
+ sys.exit(main())
