/
bootstrap.go
149 lines (130 loc) · 3.24 KB
/
bootstrap.go
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package bootstrap
import (
"fmt"
"go/format"
"io/ioutil"
"os"
"os/exec"
"path/filepath"
"regexp"
"sort"
)
const genPackage = "github.com/abba5/get-generator/gen"
var buildFlagsRegexp = regexp.MustCompile("'.+'|\".+\"|\\S+")
type Generator struct {
PkgPath, PkgName string
Types []string
OutName string
BuildTags string
GenBuildFlags string
LeaveTemps bool
NoFormat bool
}
func (g *Generator) Run() error {
if err := g.writeStub(); err != nil {
return err
}
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
}
execArgs := []string{"run"}
if g.GenBuildFlags != "" {
buildFlags := buildFlagsRegexp.FindAllString(g.GenBuildFlags, -1)
execArgs = append(execArgs, buildFlags...)
}
execArgs = append(execArgs, "-tags", g.BuildTags, filepath.Base(path))
cmd := exec.Command("go", execArgs...)
cmd.Stdout = f
cmd.Stderr = os.Stderr
cmd.Dir = filepath.Dir(path)
if err = cmd.Run(); err != nil {
return err
}
f.Close()
if g.NoFormat {
return os.Rename(f.Name(), g.OutName)
}
in, err := ioutil.ReadFile(f.Name())
if err != nil {
return err
}
out, err := format.Source(in)
if err != nil {
return err
}
return ioutil.WriteFile(g.OutName, out, 0644)
}
func (g *Generator) writeMain() (path string, err error) {
f, err := ioutil.TempFile(filepath.Dir(g.OutName), "getter-bootstrap")
if err != nil {
return "", err
}
fmt.Fprintln(f, "// +build ignore")
fmt.Fprintln(f)
fmt.Fprintln(f, "// TEMPORARY AUTOGENERATED FILE: get generator 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)
sort.Strings(g.Types)
for _, v := range g.Types {
fmt.Fprintln(f, " g.Add(pkg.GET_GENERATOR_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) 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: getter stub code to make the package")
fmt.Fprintln(f, "// compilable during generation.")
fmt.Fprintln(f)
fmt.Fprintln(f, "package ", g.PkgName)
sort.Strings(g.Types)
for _, t := range g.Types {
fmt.Fprintln(f)
fmt.Fprintln(f, "type GET_GENERATOR_exporter_"+t+" *"+t)
}
return nil
}