ebiten/internal/png/gen.go
2024-03-24 20:36:31 +09:00

156 lines
3.2 KiB
Go

// Copyright 2018 The Ebiten Authors
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
//go:build ignore
package main
import (
"fmt"
"go/ast"
"go/format"
"go/parser"
"go/token"
"os"
"path/filepath"
"regexp"
"runtime"
"strconv"
"strings"
exec "golang.org/x/sys/execabs"
"golang.org/x/tools/go/ast/astutil"
)
func pngDir() (string, error) {
dir, err := exec.Command("go", "list", "-f", "{{.Dir}}", "image/png").Output()
if err != nil {
return "", err
}
return strings.TrimSpace(string(dir)), nil
}
func pngFiles() ([]string, error) {
files, err := exec.Command("go", "list", "-f", `{{join .GoFiles ","}}`, "image/png").Output()
if err != nil {
return nil, err
}
return strings.Split(strings.TrimSpace(string(files)), ","), nil
}
func run() error {
reVer := regexp.MustCompile(`^go1\.(\d+)(\.\d+)?$`)
verStr := runtime.Version()
m := reVer.FindStringSubmatch(verStr)
if m == nil {
return fmt.Errorf("png: unexpected Go version: %s", verStr)
}
ver, err := strconv.Atoi(m[1])
if err != nil {
return err
}
if ver < 22 {
return fmt.Errorf("png: use Go 1.22 or newer")
}
dir, err := pngDir()
if err != nil {
return err
}
files, err := pngFiles()
if err != nil {
return err
}
const prefix = "stdlib"
matches, err := filepath.Glob(prefix + "*.go")
if err != nil {
return err
}
for _, f := range matches {
if err := os.Remove(f); err != nil {
return err
}
}
for _, f := range files {
out, err := os.Create(prefix + f)
if err != nil {
return err
}
defer out.Close()
// TODO: Remove call of RegisterDecoder
data, err := os.ReadFile(filepath.Join(dir, f))
if err != nil {
return err
}
fset := token.NewFileSet()
tree, err := parser.ParseFile(fset, "", string(data), parser.ParseComments)
if err != nil {
return err
}
astutil.Apply(tree, func(c *astutil.Cursor) bool {
stmt, ok := c.Node().(*ast.ExprStmt)
if !ok {
return true
}
call, ok := stmt.X.(*ast.CallExpr)
if !ok {
return true
}
s, ok := call.Fun.(*ast.SelectorExpr)
if !ok {
return true
}
receiver, ok := s.X.(*ast.Ident)
if !ok {
return true
}
// Delete registering PNG format.
if receiver.Name == "image" && s.Sel.Name == "RegisterFormat" {
c.Delete()
}
return true
}, nil)
fmt.Fprintln(out, "// Code generated by gen.go. DO NOT EDIT.")
fmt.Fprintln(out)
format.Node(out, fset, tree)
if f == "reader.go" {
// The min function was removed as of Go 1.22, but this is needed for old Go.
// TODO: Remove this when Go 1.21 is the minimum supported version.
fmt.Fprintln(out, `
func min(a, b int) int {
if a < b {
return a
}
return b
}`)
}
}
return nil
}
func main() {
if err := run(); err != nil {
panic(err)
}
}