Merge branch 'main' into feature/pool-wildcard

Signed-off-by: Vicent Marti <vmg@strn.cat>

Makefile

@@ -46,7 +46,8 @@ gen-wkt: bin/protoc-gen-go-vtproto
         $(PROTOBUF_ROOT)/src/google/protobuf/empty.proto \
         $(PROTOBUF_ROOT)/src/google/protobuf/field_mask.proto \
         $(PROTOBUF_ROOT)/src/google/protobuf/timestamp.proto \
-        $(PROTOBUF_ROOT)/src/google/protobuf/wrappers.proto
+        $(PROTOBUF_ROOT)/src/google/protobuf/wrappers.proto \
+        $(PROTOBUF_ROOT)/src/google/protobuf/struct.proto
 
 gen-testproto: get-grpc-testproto gen-wkt-testproto install
 	$(PROTOBUF_ROOT)/src/protoc \
@@ -63,6 +64,16 @@ gen-testproto: get-grpc-testproto gen-wkt-testproto install
 		testproto/proto2/scalars.proto \
 		testproto/unsafe/unsafe.proto \
 		|| exit 1;
+	$(PROTOBUF_ROOT)/src/protoc \
+		--proto_path=testproto \
+		--proto_path=include \
+		--go_out=. --plugin protoc-gen-go="${GOBIN}/protoc-gen-go" \
+		--go-vtproto_opt=paths=source_relative \
+		--go-vtproto_opt=buildTag=vtprotobuf \
+		--go-vtproto_out=allow-empty=true:./testproto/buildtag --plugin protoc-gen-go-vtproto="${GOBIN}/protoc-gen-go-vtproto" \
+		-I$(PROTOBUF_ROOT)/src \
+		testproto/empty/empty.proto \
+		|| exit 1;
 
 get-grpc-testproto: install
 	$(PROTOBUF_ROOT)/src/protoc \

README.md

@@ -108,16 +108,24 @@ The following features can be generated:
             --go-vtproto_opt=pool=vitess.io/vitess/go/vt/proto/query.Row \
             --go-vtproto_opt=pool=vitess.io/vitess/go/vt/proto/binlogdata.VStreamRowsResponse \
     ```
+6. (Optional) if you want to selectively compile the generate `vtprotobuf` files, the `--vtproto_opt=buildTag=<tag>` can be used.
 
-6. Compile the `.proto` files in your project. You should see `_vtproto.pb.go` files next to the `.pb.go` and `_grpc.pb.go` files that were already being generated.
+    When using this option, the generated code will only be compiled in if a build tag is provided.
 
-7. (Optional) Switch your RPC framework to use the optimized helpers (see following sections)
+    It is recommended, but not required, to use `vtprotobuf` as the build tag if this is desired, especially if your project is imported by others.
+    This will reduce the number of build tags a user will need to configure if they are importing multiple libraries following this pattern.
 
-## Well-known types
+    When using this option, it is strongly recommended to make your code compile with and without the build tag.
+    This can be done with type assertions before using `vtprotobuf` generated methods.
+    The `grpc.Codec{}` object (discussed below) shows an example.
 
-By default, `vtprotobuf` will detect ProtoBuf [well-known types](https://protobuf.dev/reference/protobuf/google.protobuf/) embedded in your own Messages and generate optimized code to marshal and unmarshal them.
+7. Compile the `.proto` files in your project. You should see `_vtproto.pb.go` files next to the `.pb.go` and `_grpc.pb.go` files that were already being generated.
 
-In order to access the optimized code for these types, your `_vtproto.pb.go` files will have a dependency on this Go package. If this is not acceptable, you can disable well-known types with `--go-vtproto_opt=wkt=false`.
+8. (Optional) Switch your RPC framework to use the optimized helpers (see following sections)
+
+## `vtprotobuf` package and well-known types
+
+Your generated `_vtproto.pb.go` files will have a dependency on this Go package to access some helper functions as well as the optimized code for ProtoBuf [well-known types](https://protobuf.dev/reference/protobuf/google.protobuf/). `vtprotobuf` will detect these types embedded in your own Messages and generate optimized code to marshal and unmarshal them.
 
 ## Using the optimized code with RPC frameworks
 

cmd/protoc-gen-go-vtproto/main.go

@@ -27,8 +27,8 @@ func main() {
 	f.Var(&cfg.Poolable, "pool", "use memory pooling for this object")
 	f.Var(&cfg.PoolableExclude, "pool-exclude", "do not use memory pooling for this object")
 	f.BoolVar(&cfg.Wrap, "wrap", false, "generate wrapper types")
-	f.BoolVar(&cfg.WellKnownTypes, "wkt", true, "generate optimized code for well-known types")
 	f.StringVar(&features, "features", "all", "list of features to generate (separated by '+')")
+	f.StringVar(&cfg.BuildTag, "buildTag", "", "the go:build tag to set on generated files")
 
 	protogen.Options{ParamFunc: f.Set}.Run(func(plugin *protogen.Plugin) error {
 		gen, err := generator.NewGenerator(plugin, strings.Split(features, "+"), &cfg)