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// Copyright 2020 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
//go:build ignore
// +build ignore
package main
import (
"bytes"
"fmt"
"go/format"
"go/types"
"io/ioutil"
"log"
"reflect"
"sort"
"strings"
"golang.org/x/tools/go/packages"
)
var irPkg *types.Package
var buf bytes.Buffer
func main() {
cfg := &packages.Config{
Mode: packages.NeedSyntax | packages.NeedTypes,
}
pkgs, err := packages.Load(cfg, "cmd/compile/internal/ir")
if err != nil {
log.Fatal(err)
}
irPkg = pkgs[0].Types
fmt.Fprintln(&buf, "// Code generated by mknode.go. DO NOT EDIT.")
fmt.Fprintln(&buf)
fmt.Fprintln(&buf, "package ir")
fmt.Fprintln(&buf)
fmt.Fprintln(&buf, `import "fmt"`)
scope := irPkg.Scope()
for _, name := range scope.Names() {
if strings.HasPrefix(name, "mini") {
continue
}
obj, ok := scope.Lookup(name).(*types.TypeName)
if !ok {
continue
}
typ := obj.Type().(*types.Named)
if !implementsNode(types.NewPointer(typ)) {
continue
}
fmt.Fprintf(&buf, "\n")
fmt.Fprintf(&buf, "func (n *%s) Format(s fmt.State, verb rune) { fmtNode(n, s, verb) }\n", name)
switch name {
case "Name", "Func":
// Too specialized to automate.
continue
}
forNodeFields(typ,
"func (n *%[1]s) copy() Node { c := *n\n",
"",
"c.%[1]s = copy%[2]s(c.%[1]s)",
"return &c }\n")
forNodeFields(typ,
"func (n *%[1]s) doChildren(do func(Node) bool) bool {\n",
"if n.%[1]s != nil && do(n.%[1]s) { return true }",
"if do%[2]s(n.%[1]s, do) { return true }",
"return false }\n")
forNodeFields(typ,
"func (n *%[1]s) editChildren(edit func(Node) Node) {\n",
"if n.%[1]s != nil { n.%[1]s = edit(n.%[1]s).(%[2]s) }",
"edit%[2]s(n.%[1]s, edit)",
"}\n")
}
makeHelpers()
out, err := format.Source(buf.Bytes())
if err != nil {
// write out mangled source so we can see the bug.
out = buf.Bytes()
}
err = ioutil.WriteFile("node_gen.go", out, 0666)
if err != nil {
log.Fatal(err)
}
}
// needHelper maps needed slice helpers from their base name to their
// respective slice-element type.
var needHelper = map[string]string{}
func makeHelpers() {
var names []string
for name := range needHelper {
names = append(names, name)
}
sort.Strings(names)
for _, name := range names {
fmt.Fprintf(&buf, sliceHelperTmpl, name, needHelper[name])
}
}
const sliceHelperTmpl = `
func copy%[1]s(list []%[2]s) []%[2]s {
if list == nil {
return nil
}
c := make([]%[2]s, len(list))
copy(c, list)
return c
}
func do%[1]s(list []%[2]s, do func(Node) bool) bool {
for _, x := range list {
if x != nil && do(x) {
return true
}
}
return false
}
func edit%[1]s(list []%[2]s, edit func(Node) Node) {
for i, x := range list {
if x != nil {
list[i] = edit(x).(%[2]s)
}
}
}
`
func forNodeFields(named *types.Named, prologue, singleTmpl, sliceTmpl, epilogue string) {
fmt.Fprintf(&buf, prologue, named.Obj().Name())
anyField(named.Underlying().(*types.Struct), func(f *types.Var) bool {
if f.Embedded() {
return false
}
name, typ := f.Name(), f.Type()
slice, _ := typ.Underlying().(*types.Slice)
if slice != nil {
typ = slice.Elem()
}
tmpl, what := singleTmpl, types.TypeString(typ, types.RelativeTo(irPkg))
if implementsNode(typ) {
if slice != nil {
helper := strings.TrimPrefix(what, "*") + "s"
needHelper[helper] = what
tmpl, what = sliceTmpl, helper
}
} else if what == "*Field" {
// Special case for *Field.
tmpl = sliceTmpl
if slice != nil {
what = "Fields"
} else {
what = "Field"
}
} else {
return false
}
if tmpl == "" {
return false
}
// Allow template to not use all arguments without
// upsetting fmt.Printf.
s := fmt.Sprintf(tmpl+"\x00 %[1]s %[2]s", name, what)
fmt.Fprintln(&buf, s[:strings.LastIndex(s, "\x00")])
return false
})
fmt.Fprintf(&buf, epilogue)
}
func implementsNode(typ types.Type) bool {
if _, ok := typ.Underlying().(*types.Interface); ok {
// TODO(mdempsky): Check the interface implements Node.
// Worst case, node_gen.go will fail to compile if we're wrong.
return true
}
if ptr, ok := typ.(*types.Pointer); ok {
if str, ok := ptr.Elem().Underlying().(*types.Struct); ok {
return anyField(str, func(f *types.Var) bool {
return f.Embedded() && f.Name() == "miniNode"
})
}
}
return false
}
func anyField(typ *types.Struct, pred func(f *types.Var) bool) bool {
for i, n := 0, typ.NumFields(); i < n; i++ {
if value, ok := reflect.StructTag(typ.Tag(i)).Lookup("mknode"); ok {
if value != "-" {
panic(fmt.Sprintf("unexpected tag value: %q", value))
}
continue
}
f := typ.Field(i)
if pred(f) {
return true
}
if f.Embedded() {
if typ, ok := f.Type().Underlying().(*types.Struct); ok {
if anyField(typ, pred) {
return true
}
}
}
}
return false
}
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