Explicit dependency on executables in proto_library.gni.

third_party/protobuf/proto_library.gni

Index: third_party/protobuf/proto_library.gni
diff --git a/third_party/protobuf/proto_library.gni b/third_party/protobuf/proto_library.gni
index cca81063760ce01c567c66bdd855e5c4ab6dacef..be208e85de6e68139f5c2be9a9c0f39adabdb727 100644
--- a/third_party/protobuf/proto_library.gni
+++ b/third_party/protobuf/proto_library.gni
@@ -133,7 +133,6 @@ template("proto_library") {
     } else {
       generator_plugin_suffixes = invoker.generator_plugin_suffixes
     }
-    plugin_path = rebase_path(plugin_path, root_build_dir)
   }
 
   if (defined(invoker.proto_in_dir)) {
@@ -216,23 +215,18 @@ template("proto_library") {
     outputs = get_path_info(protogens, "abspath")
     args = protos
 
-    if (defined(invoker.generator_plugin_script)) {
-      inputs = [
-        invoker.generator_plugin_script,

[kraynov, 2016/10/18 12:35:52]

It's not missing :)
invoker.generator_plugin_script == plugin_path
See line 284 at the right pane.

[sdefresne, 2016/10/18 22:44:54]

Ack.

-      ]
-    }
-    if (defined(invoker.generator_plugin_script_deps)) {
-      inputs += invoker.generator_plugin_script_deps
+    protoc_label = "//third_party/protobuf:protoc($host_toolchain)"
+    protoc_path = get_label_info(protoc_label, "root_out_dir") + "/protoc"

[sdefresne, 2016/10/18 22:44:54]

    protoc_path = get_label_info(protoc_label, "root_out_dir") + "/protoc" +
        _host_executable_suffix

[kraynov, 2016/10/19 11:04:59]

Done.

+    if (host_os == "win") {
+      protoc_path += ".exe"
     }
 
-    protoc_label = "//third_party/protobuf:protoc($host_toolchain)"
-    protoc_out_dir = get_label_info(protoc_label, "root_out_dir")
     args += [
       # Wrapper should never pick a system protoc.
       # Path should be rebased because |root_build_dir| for current toolchain
       # may be different from |root_out_dir| of protoc built on host toolchain.
       "--protoc",
-      "./" + rebase_path(protoc_out_dir, root_build_dir) + "/protoc",
+      rebase_path(protoc_path, root_build_dir),
       "--proto-in-dir",
       rebase_path(proto_in_dir, root_build_dir),
     ]
@@ -266,7 +260,7 @@ template("proto_library") {
     if (generate_with_plugin) {
       args += [
         "--plugin",
-        plugin_path,
+        rebase_path(plugin_path, root_build_dir),
         "--plugin-out-dir",
         rel_cc_out_dir,
       ]
@@ -278,14 +272,26 @@ template("proto_library") {
       }
     }
 
+    # System protoc is not used so it's necessary to build a chromium one.
+    inputs = [
+      protoc_path,
+    ]
     deps = [
-      # System protoc is not used so it's necessary to build a chromium one.
       protoc_label,
     ]
-    if (defined(plugin_host_label)) {
-      # Action depends on generator plugin but for host toolchain only.
-      deps += [ plugin_host_label ]
+
+    if (generate_with_plugin) {
+      inputs += [ plugin_path ]
+      if (defined(invoker.generator_plugin_script_deps)) {
+        # Additional scripts for plugin.
+        inputs += invoker.generator_plugin_script_deps
+      }
+      if (defined(plugin_host_label)) {
+        # Action depends on native generator plugin but for host toolchain only.
+        deps += [ plugin_host_label ]
+      }
     }
+
     if (defined(invoker.deps)) {
       # The deps may have steps that have to run before running protoc.
       deps += invoker.deps