ceph-csi/vendor/github.com/mailru/easyjson/bootstrap/bootstrap.go

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2018-01-09 18:57:14 +00:00
// Package bootstrap implements the bootstrapping logic: generation of a .go file to
// launch the actual generator and launching the generator itself.
//
// The package may be preferred to a command-line utility if generating the serializers
// from golang code is required.
package bootstrap
import (
"fmt"
"io/ioutil"
"os"
"os/exec"
"path/filepath"
"sort"
)
const genPackage = "github.com/mailru/easyjson/gen"
const pkgWriter = "github.com/mailru/easyjson/jwriter"
const pkgLexer = "github.com/mailru/easyjson/jlexer"
type Generator struct {
PkgPath, PkgName string
Types []string
NoStdMarshalers bool
SnakeCase bool
LowerCamelCase bool
OmitEmpty bool
OutName string
BuildTags string
StubsOnly bool
LeaveTemps bool
NoFormat bool
}
// writeStub outputs an initial stubs for marshalers/unmarshalers so that the package
// using marshalers/unmarshales compiles correctly for boostrapping code.
func (g *Generator) writeStub() error {
f, err := os.Create(g.OutName)
if err != nil {
return err
}
defer f.Close()
if g.BuildTags != "" {
fmt.Fprintln(f, "// +build ", g.BuildTags)
fmt.Fprintln(f)
}
fmt.Fprintln(f, "// TEMPORARY AUTOGENERATED FILE: easyjson stub code to make the package")
fmt.Fprintln(f, "// compilable during generation.")
fmt.Fprintln(f)
fmt.Fprintln(f, "package ", g.PkgName)
if len(g.Types) > 0 {
fmt.Fprintln(f)
fmt.Fprintln(f, "import (")
fmt.Fprintln(f, ` "`+pkgWriter+`"`)
fmt.Fprintln(f, ` "`+pkgLexer+`"`)
fmt.Fprintln(f, ")")
}
sort.Strings(g.Types)
for _, t := range g.Types {
fmt.Fprintln(f)
if !g.NoStdMarshalers {
fmt.Fprintln(f, "func (", t, ") MarshalJSON() ([]byte, error) { return nil, nil }")
fmt.Fprintln(f, "func (*", t, ") UnmarshalJSON([]byte) error { return nil }")
}
fmt.Fprintln(f, "func (", t, ") MarshalEasyJSON(w *jwriter.Writer) {}")
fmt.Fprintln(f, "func (*", t, ") UnmarshalEasyJSON(l *jlexer.Lexer) {}")
fmt.Fprintln(f)
fmt.Fprintln(f, "type EasyJSON_exporter_"+t+" *"+t)
}
return nil
}
// writeMain creates a .go file that launches the generator if 'go run'.
func (g *Generator) writeMain() (path string, err error) {
f, err := ioutil.TempFile(filepath.Dir(g.OutName), "easyjson-bootstrap")
if err != nil {
return "", err
}
fmt.Fprintln(f, "// +build ignore")
fmt.Fprintln(f)
fmt.Fprintln(f, "// TEMPORARY AUTOGENERATED FILE: easyjson bootstapping code to launch")
fmt.Fprintln(f, "// the actual generator.")
fmt.Fprintln(f)
fmt.Fprintln(f, "package main")
fmt.Fprintln(f)
fmt.Fprintln(f, "import (")
fmt.Fprintln(f, ` "fmt"`)
fmt.Fprintln(f, ` "os"`)
fmt.Fprintln(f)
fmt.Fprintf(f, " %q\n", genPackage)
if len(g.Types) > 0 {
fmt.Fprintln(f)
fmt.Fprintf(f, " pkg %q\n", g.PkgPath)
}
fmt.Fprintln(f, ")")
fmt.Fprintln(f)
fmt.Fprintln(f, "func main() {")
fmt.Fprintf(f, " g := gen.NewGenerator(%q)\n", filepath.Base(g.OutName))
fmt.Fprintf(f, " g.SetPkg(%q, %q)\n", g.PkgName, g.PkgPath)
if g.BuildTags != "" {
fmt.Fprintf(f, " g.SetBuildTags(%q)\n", g.BuildTags)
}
if g.SnakeCase {
fmt.Fprintln(f, " g.UseSnakeCase()")
}
if g.LowerCamelCase {
fmt.Fprintln(f, " g.UseLowerCamelCase()")
}
if g.OmitEmpty {
fmt.Fprintln(f, " g.OmitEmpty()")
}
if g.NoStdMarshalers {
fmt.Fprintln(f, " g.NoStdMarshalers()")
}
sort.Strings(g.Types)
for _, v := range g.Types {
fmt.Fprintln(f, " g.Add(pkg.EasyJSON_exporter_"+v+"(nil))")
}
fmt.Fprintln(f, " if err := g.Run(os.Stdout); err != nil {")
fmt.Fprintln(f, " fmt.Fprintln(os.Stderr, err)")
fmt.Fprintln(f, " os.Exit(1)")
fmt.Fprintln(f, " }")
fmt.Fprintln(f, "}")
src := f.Name()
if err := f.Close(); err != nil {
return src, err
}
dest := src + ".go"
return dest, os.Rename(src, dest)
}
func (g *Generator) Run() error {
if err := g.writeStub(); err != nil {
return err
}
if g.StubsOnly {
return nil
}
path, err := g.writeMain()
if err != nil {
return err
}
if !g.LeaveTemps {
defer os.Remove(path)
}
f, err := os.Create(g.OutName + ".tmp")
if err != nil {
return err
}
if !g.LeaveTemps {
defer os.Remove(f.Name()) // will not remove after rename
}
cmd := exec.Command("go", "run", "-tags", g.BuildTags, path)
cmd.Stdout = f
cmd.Stderr = os.Stderr
if err = cmd.Run(); err != nil {
return err
}
f.Close()
if !g.NoFormat {
cmd = exec.Command("gofmt", "-w", f.Name())
cmd.Stderr = os.Stderr
cmd.Stdout = os.Stdout
if err = cmd.Run(); err != nil {
return err
}
}
return os.Rename(f.Name(), g.OutName)
}