Move plugins to own module & improve apigen CLI

This patch moves the binapigenerator plugins to their own package.
- It capitalizes the methods they leverage.
- It changes the way plugins are called, passing the whole generator
at once and letting the plugin themselves loop on the files.
This allow for more variety in filtering, aggregation, etc...

This patch also proposes an evolution to the binapigen CLI
in order to make it more user-friendly for newcomers as well
as build pipelines based on go:generate

For now two usecases are in the picture:
- Building from a directory containing .json files
e.g. 'binapigen --api /usr/share/vpp/api --output ./myapp/bindings --filter interface,ip'
- Building from a cloned local VPP
e.g. 'binapigen --vpp ~/vpp --output ./myapp/binding'

Signed-off-by: Nathan Skrzypczak <nathan.skrzypczak@gmail.com>
Change-Id: I5b0b2ade40ab80c9e91c2a422f8c193b232d9830

binapigen/binapigen.go

@@ -380,7 +380,7 @@ func getMsgType(m vppapi.Message) (msgType, error) {
 	return typ, nil
 }
 
-func getRetvalField(m *Message) *Field {
+func GetRetvalField(m *Message) *Field {
 	for _, field := range m.Fields {
 		if field.Name == fieldRetval {
 			return field

binapigen/binapigen_test.go

@@ -15,43 +15,56 @@
 package binapigen
 
 import (
+	"os"
+	"path/filepath"
 	"testing"
 
 	. "github.com/onsi/gomega"
-
-	"go.fd.io/govpp/binapigen/vppapi"
 )
 
+var sampleJson = `{
+    "types": [],
+    "messages": [],
+    "unions": [],
+    "enums": [],
+    "enumflags": [],
+    "services": {},
+    "options": {
+        "version": "1.7.0"
+    },
+    "aliases": {},
+    "vl_api_version": "0x12345678",
+    "imports": [],
+    "counters": [],
+    "paths": []
+}`
+
 func TestGenerator(t *testing.T) {
-	tests := []struct {
-		name          string
-		file          *vppapi.File
-		expectPackage string
-	}{
-		{name: "vpe", file: &vppapi.File{
-			Name: "vpe",
-			Path: "/usr/share/vpp/api/core/vpe.api.json",
-			CRC:  "0x12345678",
-		},
-			expectPackage: "vpe",
-		},
+	RegisterTestingT(t)
+
+	dir, err := os.MkdirTemp("", "govpp-test")
+	if err != nil {
+		t.Fatal(err)
 	}
-	for _, test := range tests {
-		t.Run(test.name, func(t *testing.T) {
-			RegisterTestingT(t)
+	defer os.RemoveAll(dir)
 
-			apiFiles := []*vppapi.File{test.file}
+	file := filepath.Join(dir, "vpe.api.json")
+	if err := os.WriteFile(file, []byte(sampleJson), 0666); err != nil {
+		t.Fatal(err)
+	}
 
-			gen, err := New(Options{
-				ImportPrefix: "test",
-			}, apiFiles, nil)
-			Expect(err).ToNot(HaveOccurred(), "unexpected generator error: %v", err)
+	os.Setenv(VPPVersionEnvVar, "test-version")
+	gen, err := New(Options{
+		ApiDir:       dir,
+		FileFilter:   []string{file},
+		ImportPrefix: "test",
+	})
+	Expect(err).ToNot(HaveOccurred(), "unexpected generator error: %v", err)
 
-			Expect(gen.Files).To(HaveLen(1))
-			Expect(gen.Files[0].PackageName).To(BeEquivalentTo(test.expectPackage))
-			Expect(gen.Files[0].GoImportPath).To(BeEquivalentTo("test/" + test.expectPackage))
-		})
-	}
+	Expect(gen.Files).To(HaveLen(1))
+	Expect(gen.Files[0].PackageName).To(BeEquivalentTo("vpe"))
+	Expect(gen.Files[0].GoImportPath).To(BeEquivalentTo("test/vpe"))
+	Expect(gen.Files[0].Desc.CRC).To(BeEquivalentTo("0x12345678"))
 }
 
 func TestSanitize(t *testing.T) {

binapigen/gen_encoding.go

@@ -310,7 +310,7 @@ func decodeField(g *GenFile, field *Field, name string, getFieldName func(string
 		if field.Length > 0 {
 			g.P("for ", index, " := 0; ", index, " < ", field.Length, ";", index, "++ {")
 		} else if field.SizeFrom != "" {
-			g.P(name, " = make(", getFieldType(g, field), ", ", sizeFromName, ")")
+			g.P(name, " = make(", GetFieldType(g, field), ", ", sizeFromName, ")")
 			g.P("for ", index, " := 0; ", index, " < len(", name, ");", index, "++ {")
 		}
 		name = fmt.Sprintf("%s[%s]", name, index)

binapigen/generate.go

@@ -60,8 +60,7 @@ func GenerateAPI(gen *Generator, file *File) *GenFile {
 	logf("----------------------------")
 
 	filename := path.Join(file.FilenamePrefix, file.Desc.Name+".ba.go")
-	g := gen.NewGenFile(filename, file.GoImportPath)
-	g.file = file
+	g := gen.NewGenFile(filename, file)
 
 	g.P("// Code generated by GoVPP's binapi-generator. DO NOT EDIT.")
 	if !gen.opts.NoVersionInfo {
@@ -317,7 +316,7 @@ func genUnion(g *GenFile, union *Union) {
 	// generate field comments
 	g.P("// ", union.GoName, " can be one of:")
 	for _, field := range union.Fields {
-		g.P("// - ", field.GoName, " *", getFieldType(g, field))
+		g.P("// - ", field.GoName, " *", GetFieldType(g, field))
 	}
 
 	// generate data field
@@ -377,7 +376,7 @@ func genField(g *GenFile, fields []*Field, i int) {
 
 	logf(" gen FIELD[%d] %s (%s) - type: %q (array: %v/%v)", i, field.GoName, field.Name, field.Type, field.Array, field.Length)
 
-	gotype := getFieldType(g, field)
+	gotype := GetFieldType(g, field)
 	tags := structTags{
 		"binapi": fieldTagBinapi(field),
 		"json":   fieldTagJson(field),
@@ -520,7 +519,7 @@ func genMessageMethods(g *GenFile, msg *Message) {
 	if msg.msgType == msgTypeReply || msg.msgType == msgTypeEvent {
 		// GetRetVal method
 		g.P("func (m *", msg.GoIdent.GoName, ") GetRetVal() error {")
-		if getRetvalField(msg) != nil {
+		if GetRetvalField(msg) != nil {
 			g.P("	return api.RetvalToVPPApiError(int32(m.Retval))")
 		} else {
 			g.P("	return nil")

binapigen/generate_test.go

@@ -21,26 +21,19 @@ import (
 	. "github.com/onsi/gomega"
 
 	"go.fd.io/govpp/binapi/ip_types"
-	"go.fd.io/govpp/binapigen/vppapi"
 )
 
 const testOutputDir = "test_output_dir"
 
-func GenerateFromFile(file string, opts Options) error {
-	apifile, err := vppapi.ParseFile(file)
+func GenerateFromFile(filename string) error {
+	os.Setenv(VPPVersionEnvVar, "test-version")
+	gen, err := New(Options{
+		OutputDir: testOutputDir,
+		ApiDir:    filename,
+	})
 	if err != nil {
 		return err
 	}
-	gen, err := New(opts, []*vppapi.File{apifile}, nil)
-	if err != nil {
-		return err
-	}
-	for _, file := range gen.Files {
-		if !file.Generate {
-			continue
-		}
-		GenerateAPI(gen, file)
-	}
 	if err = gen.Generate(); err != nil {
 		return err
 	}
@@ -53,8 +46,7 @@ func TestGenerateFromFileACL(t *testing.T) {
 	// remove directory created during test
 	defer os.RemoveAll(testOutputDir)
 
-	opts := Options{OutputDir: testOutputDir}
-	err := GenerateFromFile("vppapi/testdata/acl.api.json", opts)
+	err := GenerateFromFile("vppapi/testdata/acl.api.json")
 	Expect(err).ShouldNot(HaveOccurred())
 	fileInfo, err := os.Stat(testOutputDir + "/acl/acl.ba.go")
 	Expect(err).ShouldNot(HaveOccurred())
@@ -68,8 +60,7 @@ func TestGenerateFromFileIP(t *testing.T) {
 	// remove directory created during test
 	defer os.RemoveAll(testOutputDir)
 
-	opts := Options{OutputDir: testOutputDir}
-	err := GenerateFromFile("vppapi/testdata/ip.api.json", opts)
+	err := GenerateFromFile("vppapi/testdata/ip.api.json")
 	Expect(err).ShouldNot(HaveOccurred())
 	fileInfo, err := os.Stat(testOutputDir + "/ip/ip.ba.go")
 	Expect(err).ShouldNot(HaveOccurred())
@@ -80,17 +71,15 @@ func TestGenerateFromFileIP(t *testing.T) {
 func TestGenerateFromFileInputError(t *testing.T) {
 	RegisterTestingT(t)
 
-	opts := Options{OutputDir: testOutputDir}
-	err := GenerateFromFile("vppapi/testdata/nonexisting.json", opts)
+	err := GenerateFromFile("vppapi/testdata/nonexisting.json")
 	Expect(err).Should(HaveOccurred())
-	Expect(err.Error()).To(ContainSubstring("unsupported"))
+	Expect(err.Error()).To(ContainSubstring("vppapi/testdata/nonexisting.json does not exist"))
 }
 
 func TestGenerateFromFileReadJsonError(t *testing.T) {
 	RegisterTestingT(t)
 
-	opts := Options{OutputDir: testOutputDir}
-	err := GenerateFromFile("vppapi/testdata/input-read-json-error.json", opts)
+	err := GenerateFromFile("vppapi/testdata/input-read-json-error.json")
 	Expect(err).Should(HaveOccurred())
 	Expect(err.Error()).To(ContainSubstring("unsupported"))
 }
@@ -106,8 +95,7 @@ func TestGenerateFromFileGeneratePackageError(t *testing.T) {
 		os.RemoveAll(testOutputDir)
 	}()
 
-	opts := Options{OutputDir: testOutputDir}
-	err := GenerateFromFile("vppapi/testdata/input-generate-error.json", opts)
+	err := GenerateFromFile("vppapi/testdata/input-generate-error.json")
 	Expect(err).Should(HaveOccurred())
 }