Format generated Go source code in-process

This commit:
- removes dependency on gofmt tool
- cleans up package imports
- re-generates binapi for VPP 20.01

Change-Id: Ie4347720f92a87eb278be66c9f9ed9719c7bbbc3
Signed-off-by: Ondrej Fabry <[email protected]>

Author: ondrej-fabry

CHANGELOG.md

@@ -11,6 +11,12 @@ This file lists changes for the GoVPP releases.
 -
 -->
 
+## 0.3.4
+> _17 April 2020_
+
+### Features
+- Format generated Go source code in-process
+
 ## 0.3.3
 > _9 April 2020_
 

Makefile

@@ -97,7 +97,6 @@ gen-binapi-docker: install-generator ## Generate binapi code (using Docker)
 	@echo "# generating binapi in docker image ${VPP_IMG}"
 	$(eval cmds := $(shell go generate -n $(BINAPI_DIR) 2>&1 | tr "\n" ";"))
 	docker run -t --rm \
-		-v "$(shell which gofmt):/usr/local/bin/gofmt:ro" \
 		-v "$(shell which binapi-generator):/usr/local/bin/binapi-generator:ro" \
 		-v "$(shell pwd):/govpp" -w /govpp \
 		-u "$(shell id -u):$(shell id -g)" \

cmd/binapi-generator/generate.go

@@ -36,8 +36,6 @@ 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
-
 	constModuleName = "ModuleName" // module name constant
 	constAPIVersion = "APIVersion" // API version constant
 	constVersionCrc = "VersionCrc" // version CRC constant
@@ -244,11 +242,12 @@ func generateHeader(ctx *context, w io.Writer) {
 
 func generateImports(ctx *context, w io.Writer) {
 	fmt.Fprintln(w, "import (")
-	fmt.Fprintf(w, "\tapi \"%s\"\n", govppApiImportPath)
-	fmt.Fprintf(w, "\tbytes \"%s\"\n", "bytes")
-	fmt.Fprintf(w, "\tcontext \"%s\"\n", "context")
-	fmt.Fprintf(w, "\tio \"%s\"\n", "io")
-	fmt.Fprintf(w, "\tstrconv \"%s\"\n", "strconv")
+	fmt.Fprintln(w, `	"bytes"`)
+	fmt.Fprintln(w, `	"context"`)
+	fmt.Fprintln(w, `	"io"`)
+	fmt.Fprintln(w, `	"strconv"`)
+	fmt.Fprintln(w)
+	fmt.Fprintf(w, "\tapi \"%s\"\n", "git.fd.io/govpp.git/api")
 	fmt.Fprintf(w, "\tstruc \"%s\"\n", "github.com/lunixbochs/struc")
 	if len(ctx.packageData.Imports) > 0 {
 		fmt.Fprintln(w)

cmd/binapi-generator/main.go

@@ -19,9 +19,9 @@ import (
 	"encoding/json"
 	"flag"
 	"fmt"
+	"go/format"
 	"io/ioutil"
 	"os"
-	"os/exec"
 	"path/filepath"
 	"strings"
 
@@ -204,10 +204,15 @@ func generateFromFile(inputFile, outputDir string, typesPkgs []*context) error {
 		}
 	}
 
-	// generate Go package code
+	// generate Go package
 	var buf bytes.Buffer
 	if err := generatePackage(ctx, &buf); err != nil {
-		return fmt.Errorf("generating code for package %s failed: %v", ctx.packageName, err)
+		return fmt.Errorf("generating Go package for %s failed: %v", ctx.packageName, err)
+	}
+	// format generated source code
+	gosrc, err := format.Source(buf.Bytes())
+	if err != nil {
+		return fmt.Errorf("formatting source code for package %s failed: %v", ctx.packageName, err)
 	}
 
 	// create output directory
@@ -216,16 +221,10 @@ func generateFromFile(inputFile, outputDir string, typesPkgs []*context) error {
 		return fmt.Errorf("creating output dir %s failed: %v", packageDir, err)
 	}
 	// write generated code to output file
-	if err := ioutil.WriteFile(ctx.outputFile, buf.Bytes(), 0666); err != nil {
+	if err := ioutil.WriteFile(ctx.outputFile, gosrc, 0666); err != nil {
 		return fmt.Errorf("writing to output file %s failed: %v", ctx.outputFile, err)
 	}
 
-	// go format the output file (fail probably means the output is not compilable)
-	cmd := exec.Command("gofmt", "-w", ctx.outputFile)
-	if output, err := cmd.CombinedOutput(); err != nil {
-		return fmt.Errorf("gofmt failed: %v\n%s", err, string(output))
-	}
-
 	return nil
 }