Check retval value and convert to error in generated RPC client code

Change-Id: I816b4802cb5fc46239f6db0480fa4cf3645fe2f0
Signed-off-by: Ondrej Fabry <ofabry@cisco.com>

4 files changed, 39 insertions, 18 deletions

diff --git a/binapigen/binapigen.go b/binapigen/binapigen.go
index 35a07d0..de6a804 100644
--- a/binapigen/binapigen.go
+++ b/binapigen/binapigen.go
@@ -243,8 +243,8 @@ func newStruct(gen *Generator, file *File, apitype vppapi.StructType) *Struct {
 		},
 	}
 	gen.structsByName[typ.Name] = typ
-	for _, fieldType := range apitype.Fields {
-		field := newField(gen, file, typ, fieldType)
+	for i, fieldType := range apitype.Fields {
+		field := newField(gen, file, typ, fieldType, i)
 		typ.Fields = append(typ.Fields, field)
 	}
 	return typ
@@ -276,8 +276,8 @@ func newUnion(gen *Generator, file *File, apitype vppapi.UnionType) *Union {
 		},
 	}
 	gen.unionsByName[typ.Name] = typ
-	for _, fieldType := range apitype.Fields {
-		field := newField(gen, file, typ, fieldType)
+	for i, fieldType := range apitype.Fields {
+		field := newField(gen, file, typ, fieldType, i)
 		typ.Fields = append(typ.Fields, field)
 	}
 	return typ
@@ -302,11 +302,12 @@ const (
 	msgTypeEvent                  // msg_id, client_index
 )
 
-// message fields
+// common message fields
 const (
 	fieldMsgID       = "_vl_msg_id"
 	fieldClientIndex = "client_index"
 	fieldContext     = "context"
+	fieldRetval      = "retval"
 )
 
 // field options
@@ -343,7 +344,7 @@ func newMessage(gen *Generator, file *File, apitype vppapi.Message) *Message {
 			}
 		}
 		n++
-		field := newField(gen, file, msg, fieldType)
+		field := newField(gen, file, msg, fieldType, n)
 		msg.Fields = append(msg.Fields, field)
 	}
 	return msg
@@ -394,12 +395,24 @@ func getMsgType(m vppapi.Message) (msgType, error) {
 	return typ, nil
 }
 
+func getRetvalField(m *Message) *Field {
+	for _, field := range m.Fields {
+		if field.Name == fieldRetval {
+			return field
+		}
+	}
+	return nil
+}
+
 // Field represents a field for message or struct/union types.
 type Field struct {
 	vppapi.Field
 
 	GoName string
 
+	// Index defines field index in parent.
+	Index int
+
 	// DefaultValue is a default value of field or
 	// nil if default value is not defined for field.
 	DefaultValue interface{}
@@ -423,10 +436,11 @@ type Field struct {
 	FieldSizeFrom *Field
 }
 
-func newField(gen *Generator, file *File, parent interface{}, apitype vppapi.Field) *Field {
+func newField(gen *Generator, file *File, parent interface{}, apitype vppapi.Field, index int) *Field {
 	typ := &Field{
 		Field:  apitype,
 		GoName: camelCaseName(apitype.Name),
+		Index:  index,
 	}
 	switch p := parent.(type) {
 	case *Message:
diff --git a/binapigen/gen_rest.go b/binapigen/gen_http.go
index 6ddb57a..4c9697e 100644
--- a/binapigen/gen_rest.go
+++ b/binapigen/gen_http.go
@@ -20,7 +20,7 @@ import (
 )
 
 func init() {
-	RegisterPlugin("rest", GenerateREST)
+	RegisterPlugin("http", GenerateHTTP)
 }
 
 // library dependencies
@@ -30,16 +30,16 @@ const (
 	jsonPkg   = GoImportPath("encoding/json")
 )
 
-func GenerateREST(gen *Generator, file *File) *GenFile {
+func GenerateHTTP(gen *Generator, file *File) *GenFile {
 	if file.Service == nil {
 		return nil
 	}
 
 	logf("----------------------------")
-	logf(" Generate REST - %s", file.Desc.Name)
+	logf(" Generate HTTP - %s", file.Desc.Name)
 	logf("----------------------------")
 
-	filename := path.Join(file.FilenamePrefix, file.Desc.Name+"_rest.ba.go")
+	filename := path.Join(file.FilenamePrefix, file.Desc.Name+"_http.ba.go")
 	g := gen.NewGenFile(filename, file.GoImportPath)
 	g.file = file
 
@@ -51,15 +51,15 @@ func GenerateREST(gen *Generator, file *File) *GenFile {
 
 	// generate RPC service
 	if len(file.Service.RPCs) > 0 {
-		genRESTHandler(g, file.Service)
+		genHTTPHandler(g, file.Service)
 	}
 
 	return g
 }
 
-func genRESTHandler(g *GenFile, svc *Service) {
+func genHTTPHandler(g *GenFile, svc *Service) {
 	// generate handler constructor
-	g.P("func RESTHandler(rpc ", serviceApiName, ") ", httpPkg.Ident("Handler"), " {")
+	g.P("func HTTPHandler(rpc ", serviceApiName, ") ", httpPkg.Ident("Handler"), " {")
 	g.P("	mux := ", httpPkg.Ident("NewServeMux"), "()")
 
 	// generate http handlers for rpc
diff --git a/binapigen/gen_rpc.go b/binapigen/gen_rpc.go
index ba23f4a..a5974c3 100644
--- a/binapigen/gen_rpc.go
+++ b/binapigen/gen_rpc.go
@@ -71,7 +71,7 @@ func GenerateRPC(gen *Generator, file *File) *GenFile {
 
 func genService(g *GenFile, svc *Service) {
 	// generate comment
-	g.P("// ", serviceApiName, " defines RPC service  ", g.file.Desc.Name, ".")
+	g.P("// ", serviceApiName, " defines RPC service ", g.file.Desc.Name, ".")
 
 	// generate service interface
 	g.P("type ", serviceApiName, " interface {")
@@ -160,7 +160,15 @@ func genService(g *GenFile, svc *Service) {
 			g.P("out := new(", rpc.MsgReply.GoIdent, ")")
 			g.P("err := c.conn.Invoke(ctx, in, out)")
 			g.P("if err != nil { return nil, err }")
-			g.P("return out, nil")
+			if retvalField := getRetvalField(rpc.MsgReply); retvalField != nil {
+				if fieldType := getFieldType(g, retvalField); fieldType == "int32" {
+					g.P("return out, ", govppApiPkg.Ident("RetvalToVPPApiError"), "(out.", retvalField.GoName, ")")
+				} else {
+					g.P("return out, ", govppApiPkg.Ident("RetvalToVPPApiError"), "(int32(out.", retvalField.GoName, "))")
+				}
+			} else {
+				g.P("return out, nil")
+			}
 		} else {
 			g.P("stream, err := c.conn.NewStream(ctx)")
 			g.P("if err != nil { return err }")
diff --git a/binapigen/run.go b/binapigen/run.go
index 8bb88fb..d632519 100644
--- a/binapigen/run.go
+++ b/binapigen/run.go
@@ -53,7 +53,7 @@ func run(apiDir string, filesToGenerate []string, opts Options, fn func(*Generat
 		if err != nil {
 			return fmt.Errorf("cannot resolve import path for output dir %s: %w", opts.OutputDir, err)
 		}
-		logrus.Infof("resolved import path prefix: %s", opts.ImportPrefix)
+		logrus.Debugf("resolved import path prefix: %s", opts.ImportPrefix)
 	}
 
 	gen, err := New(opts, apiFiles, filesToGenerate)
@@ -73,7 +73,6 @@ func run(apiDir string, filesToGenerate []string, opts Options, fn func(*Generat
 			return err
 		}
 	}
-
 	if err = gen.Generate(); err != nil {
 		return err
 	}