From 5f3b724323be8afccae8e72bebfcc059b9c40032 Mon Sep 17 00:00:00 2001
From: Kazuyoshi Kato <katokazu@amazon.com>
Date: Tue, 19 Apr 2022 21:39:52 +0000
Subject: [PATCH] Fix protoc-gen-go-fieldpath

The generator has to handle nested fields such as
https://github.com/containerd/containerd/blob/902212651b12e4d81b7bc779632b2e4da0a8e673/api/events/container.proto#L31-L35.

Signed-off-by: Kazuyoshi Kato <katokazu@amazon.com>
---
 cmd/protoc-gen-go-fieldpath/generator.go | 32 ++++++++++++++++++++++--
 1 file changed, 30 insertions(+), 2 deletions(-)

diff --git a/cmd/protoc-gen-go-fieldpath/generator.go b/cmd/protoc-gen-go-fieldpath/generator.go
index 2aa6a8cb3..229f9c48e 100644
--- a/cmd/protoc-gen-go-fieldpath/generator.go
+++ b/cmd/protoc-gen-go-fieldpath/generator.go
@@ -130,7 +130,7 @@ func (gen *generator) genFieldMethod(m *protogen.Message) {
 }
 
 func isMessageField(f *protogen.Field) bool {
-	return f.Desc.Kind() == protoreflect.MessageKind && f.GoIdent.GoName != "Timestamp"
+	return f.Desc.Kind() == protoreflect.MessageKind && f.Desc.Cardinality() != protoreflect.Repeated && f.Message.GoIdent.GoName != "Timestamp"
 }
 
 func isLabelsField(f *protogen.Field) bool {
@@ -138,7 +138,24 @@ func isLabelsField(f *protogen.Field) bool {
 }
 
 func isAnyField(f *protogen.Field) bool {
-	return f.Desc.Kind() == protoreflect.MessageKind && f.GoIdent.GoName == "Any"
+	return f.Desc.Kind() == protoreflect.MessageKind && f.Message.GoIdent.GoName == "Any"
+}
+
+func collectChildlen(parent *protogen.Message) ([]*protogen.Message, error) {
+	var children []*protogen.Message
+	for _, child := range parent.Messages {
+		if child.Desc.IsMapEntry() {
+			continue
+		}
+		children = append(children, child)
+
+		xs, err := collectChildlen(child)
+		if err != nil {
+			return nil, err
+		}
+		children = append(children, xs...)
+	}
+	return children, nil
 }
 
 func generate(plugin *protogen.Plugin, input *protogen.File) error {
@@ -148,7 +165,18 @@ func generate(plugin *protogen.Plugin, input *protogen.File) error {
 	file.P("package ", input.GoPackageName)
 
 	gen := newGenerator(file)
+
+	var messages []*protogen.Message
 	for _, m := range input.Messages {
+		messages = append(messages, m)
+		children, err := collectChildlen(m)
+		if err != nil {
+			return err
+		}
+		messages = append(messages, children...)
+	}
+
+	for _, m := range messages {
 		gen.genFieldMethod(m)
 	}
 	return nil