Merge pull request #27 from gengo/feature/report-parse-error

Report semantic errors in the source to protoc

protoc-gen-grpc-gateway/descriptor/services.go

@@ -15,17 +15,20 @@ import (
 // It must be called after loadFile is called for all files so that loadServices
 // can resolve names of message types and their fields.
 func (r *Registry) loadServices(targetFile string) error {
+	glog.V(1).Infof("Loading services from %s", targetFile)
 	file := r.files[targetFile]
 	if file == nil {
 		return fmt.Errorf("no such file: %s", targetFile)
 	}
 	var svcs []*Service
 	for _, sd := range file.GetService() {
+		glog.V(2).Infof("Registering %s", sd.GetName())
 		svc := &Service{
 			File: file,
 			ServiceDescriptorProto: sd,
 		}
 		for _, md := range sd.GetMethod() {
+			glog.V(2).Infof("Processing %s.%s", sd.GetName(), md.GetName())
 			opts, err := extractAPIOptions(md)
 			if err != nil {
 				glog.Errorf("Failed to extract ApiMethodOptions from %s.%s: %v", svc.GetName(), md.GetName(), err)
@@ -44,6 +47,7 @@ func (r *Registry) loadServices(targetFile string) error {
 		if len(svc.Methods) == 0 {
 			continue
 		}
+		glog.V(2).Infof("Registered %s with %d method(s)", svc.GetName(), len(svc.Methods))
 		svcs = append(svcs, svc)
 	}
 	file.Services = svcs

protoc-gen-grpc-gateway/gengateway/template.go

@@ -7,6 +7,7 @@ import (
 
 	"github.com/gengo/grpc-gateway/internal"
 	"github.com/gengo/grpc-gateway/protoc-gen-grpc-gateway/descriptor"
+	"github.com/golang/glog"
 )
 
 type param struct {
@@ -58,6 +59,7 @@ func applyTemplate(p param) (string, error) {
 	var methodSeen bool
 	for _, svc := range p.Services {
 		for _, meth := range svc.Methods {
+			glog.V(2).Infof("Processing %s.%s", svc.GetName(), meth.GetName())
 			methodSeen = true
 			for _, b := range meth.Bindings {
 				if err := handlerTemplate.Execute(w, binding{Binding: b}); err != nil {

protoc-gen-grpc-gateway/main.go

@@ -66,7 +66,10 @@ func main() {
 	}
 
 	reg.SetPrefix(*importPrefix)
-	reg.Load(req)
+	if err := reg.Load(req); err != nil {
+		emitError(err)
+		return
+	}
 
 	g := gengateway.New(reg)
 
@@ -79,16 +82,25 @@ func main() {
 		targets = append(targets, f)
 	}
 
-	var resp plugin.CodeGeneratorResponse
 	out, err := g.Generate(targets)
+	glog.V(1).Info("Processed code generator request")
 	if err != nil {
-		resp.Error = proto.String(err.Error())
-	} else {
-		resp.File = out
+		emitError(err)
+		return
 	}
-	glog.V(1).Info("Processed code generator request")
+	emitFiles(out)
+}
+
+func emitFiles(out []*plugin.CodeGeneratorResponse_File) {
+	emitResp(&plugin.CodeGeneratorResponse{File: out})
+}
+
+func emitError(err error) {
+	emitResp(&plugin.CodeGeneratorResponse{Error: proto.String(err.Error())})
+}
 
-	buf, err := proto.Marshal(&resp)
+func emitResp(resp *plugin.CodeGeneratorResponse) {
+	buf, err := proto.Marshal(resp)
 	if err != nil {
 		glog.Fatal(err)
 	}