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),
]
}
