Generator improvements and cleanup

- generator now supports include-comments flag (as opt-in)
- minor code cleanup in binapi-generator
- remove obsolete unit tests
- flatten examples from examples/cmd folder
- introduce constant for checking compatibility in future versions

Change-Id: I3545f2ba4b869a3b51d6d0de7e742f3f1e1be392
Signed-off-by: Ondrej Fabry <ofabry@cisco.com>

1 files changed, 42 insertions, 19 deletions

diff --git a/cmd/binapi-generator/generate.go b/cmd/binapi-generator/generate.go
index 48c3a41..f2da08a 100644
--- a/cmd/binapi-generator/generate.go
+++ b/cmd/binapi-generator/generate.go
@@ -25,9 +25,11 @@ import (
 )
 
 const (
+	inputFileExt  = ".api.json" // file extension of the VPP API files
+	outputFileExt = ".ba.go"    // file extension of the Go generated files
+
 	govppApiImportPath = "git.fd.io/govpp.git/api" // import path of the govpp API package
-	inputFileExt       = ".api.json"               // file extension of the VPP binary API files
-	outputFileExt      = ".ba.go"                  // file extension of the Go generated files
+	constAPIVersionCrc = "APIVersionCrc"           // name for the API version CRC constant
 )
 
 // context is a structure storing data for code generation
@@ -37,6 +39,9 @@ type context struct {
 
 	inputData []byte // contents of the input file
 
+	includeAPIVersionCrc bool // include constant with API version CRC string
+	includeComments      bool // include parts of original source in comments
+
 	moduleName  string // name of the source VPP module
 	packageName string // name of the Go package being generated
 
@@ -83,10 +88,9 @@ func generatePackage(ctx *context, w *bufio.Writer) error {
 	generateHeader(ctx, w)
 	generateImports(ctx, w)
 
-	if *includeAPIVer {
-		const APIVerConstName = "VlAPIVersion"
-		fmt.Fprintf(w, "// %s represents version of the binary API module.\n", APIVerConstName)
-		fmt.Fprintf(w, "const %s = %v\n", APIVerConstName, ctx.packageData.APIVersion)
+	if ctx.includeAPIVersionCrc {
+		fmt.Fprintf(w, "// %s defines API version CRC of the VPP binary API module.\n", constAPIVersionCrc)
+		fmt.Fprintf(w, "const %s = %v\n", constAPIVersionCrc, ctx.packageData.APIVersion)
 		fmt.Fprintln(w)
 	}
 
@@ -194,9 +198,9 @@ func generateHeader(ctx *context, w io.Writer) {
 
 // generateImports writes generated package imports into w
 func generateImports(ctx *context, w io.Writer) {
-	fmt.Fprintf(w, "import \"%s\"\n", govppApiImportPath)
-	fmt.Fprintf(w, "import \"%s\"\n", "github.com/lunixbochs/struc")
-	fmt.Fprintf(w, "import \"%s\"\n", "bytes")
+	fmt.Fprintf(w, "import api \"%s\"\n", govppApiImportPath)
+	fmt.Fprintf(w, "import struc \"%s\"\n", "github.com/lunixbochs/struc")
+	fmt.Fprintf(w, "import bytes \"%s\"\n", "bytes")
 	fmt.Fprintln(w)
 
 	fmt.Fprintf(w, "// Reference imports to suppress errors if they are not otherwise used.\n")
@@ -204,6 +208,13 @@ func generateImports(ctx *context, w io.Writer) {
 	fmt.Fprintf(w, "var _ = struc.Pack\n")
 	fmt.Fprintf(w, "var _ = bytes.NewBuffer\n")
 	fmt.Fprintln(w)
+
+	/*fmt.Fprintln(w, "// This is a compile-time assertion to ensure that this generated file")
+	fmt.Fprintln(w, "// is compatible with the GoVPP api package it is being compiled against.")
+	fmt.Fprintln(w, "// A compilation error at this line likely means your copy of the")
+	fmt.Fprintln(w, "// GoVPP api package needs to be updated.")
+	fmt.Fprintln(w, "const _ = api.GoVppAPIPackageIsVersion1 // please upgrade the GoVPP api package")
+	fmt.Fprintln(w)*/
 }
 
 // generateComment writes generated comment for the object into w
@@ -214,6 +225,10 @@ func generateComment(ctx *context, w io.Writer, goName string, vppName string, o
 		fmt.Fprintf(w, "// %s represents VPP binary API %s '%s':\n", goName, objKind, vppName)
 	}
 
+	if !ctx.includeComments {
+		return
+	}
+
 	var isNotSpace = func(r rune) bool {
 		return !unicode.IsSpace(r)
 	}
@@ -271,7 +286,7 @@ func generateServices(ctx *context, w *bufio.Writer, services []Service) {
 
 	// generate interface
 	fmt.Fprintf(w, "type %s interface {\n", "Services")
-	for _, svc := range ctx.packageData.Services {
+	for _, svc := range services {
 		generateService(ctx, w, &svc)
 	}
 	fmt.Fprintln(w, "}")
@@ -284,7 +299,14 @@ func generateService(ctx *context, w io.Writer, svc *Service) {
 	reqTyp := camelCaseName(svc.RequestType)
 
 	// method name is same as parameter type name by default
-	method := svc.MethodName()
+	method := reqTyp
+	if svc.Stream {
+		// use Dump as prefix instead of suffix for stream services
+		if m := strings.TrimSuffix(method, "Dump"); method != m {
+			method = "Dump" + m
+		}
+	}
+
 	params := fmt.Sprintf("*%s", reqTyp)
 	returns := "error"
 	if replyType := camelCaseName(svc.ReplyType); replyType != "" {
@@ -450,7 +472,7 @@ func generateType(ctx *context, w io.Writer, typ *Type) {
 	for i, field := range typ.Fields {
 		// skip internal fields
 		switch strings.ToLower(field.Name) {
-		case "crc", "_vl_msg_id":
+		case crcField, msgIdField:
 			continue
 		}
 
@@ -488,17 +510,17 @@ func generateMessage(ctx *context, w io.Writer, msg *Message) {
 	n := 0
 	for i, field := range msg.Fields {
 		if i == 1 {
-			if field.Name == "client_index" {
+			if field.Name == clientIndexField {
 				// "client_index" as the second member,
 				// this might be an event message or a request
 				msgType = eventMessage
 				wasClientIndex = true
-			} else if field.Name == "context" {
+			} else if field.Name == contextField {
 				// reply needs "context" as the second member
 				msgType = replyMessage
 			}
 		} else if i == 2 {
-			if wasClientIndex && field.Name == "context" {
+			if wasClientIndex && field.Name == contextField {
 				// request needs "client_index" as the second member
 				// and "context" as the third member
 				msgType = requestMessage
@@ -507,9 +529,9 @@ func generateMessage(ctx *context, w io.Writer, msg *Message) {
 
 		// skip internal fields
 		switch strings.ToLower(field.Name) {
-		case "crc", "_vl_msg_id":
+		case crcField, msgIdField:
 			continue
-		case "client_index", "context":
+		case clientIndexField, contextField:
 			if n == 0 {
 				continue
 			}
@@ -550,9 +572,10 @@ func generateField(ctx *context, w io.Writer, fields []Field, i int) {
 	}
 
 	dataType := convertToGoType(ctx, field.Type)
-
 	fieldType := dataType
-	if field.IsArray() {
+
+	// check if it is array
+	if field.Length > 0 || field.SizeFrom != "" {
 		if dataType == "uint8" {
 			dataType = "byte"
 		}