if err != nil {
		log.Fatal(err)
	}
}

func mkbuiltin(w io.Writer) {
	pkg := "runtime"
	fset := token.NewFileSet()
	path := filepath.Join("..", "..", "compile", "internal", "typecheck", "_builtin", "runtime.go")
	f, err := parser.ParseFile(fset, path, nil, 0)
	if err != nil {
		log.Fatal(err)
	}

	decls := make(map[string]bool)

	fmt.Fprintf(w, "var builtins = [...]struct{ name string; abi int }{\n")

//go:build ignore

// Generate builtin.go from builtin/runtime.go.

package main

import (
	"bytes"
	"flag"
	"fmt"
	"go/ast"
	"go/format"
	"go/parser"
	"go/token"
	"io"
	"log"
	"os"
	"path/filepath"
	"strconv"
	"strings"
)

var stdout = flag.Bool("stdout", false, "write to stdout instead of builtin.go")

package typecheck

import (
	"cmd/compile/internal/base"
	"cmd/compile/internal/ir"
	"cmd/compile/internal/types"
	"cmd/internal/obj"
)

// LookupRuntime returns a function or variable declared in
// _builtin/runtime.go. If types_ is non-empty, successive occurrences
// of the "any" placeholder type will be substituted.
func LookupRuntime(name string, types_ ...*types.Type) *ir.Name {
	s := ir.Pkgs.Runtime.Lookup(name)

package goobj

import "internal/buildcfg"

// Builtin (compiler-generated) function references appear
// frequently. We assign special indices for them, so they
// don't need to be referenced by name.

// NBuiltin returns the number of listed builtin
// symbols.
func NBuiltin() int {
	return len(builtins)
}

// BuiltinName returns the name and ABI of the i-th
// builtin symbol.
func BuiltinName(i int) (string, int) {

// license that can be found in the LICENSE file.

// This file tests built-in calls on generic types.

// derived and expanded from cmd/compile/internal/types2/testdata/check/builtins.go2

package builtins

// close

type C0 interface{ int }
type C1 interface{ chan int }
type C2 interface{ chan int | <-chan int }
type C3 interface{ chan int | chan float32 }
type C4 interface{ chan int | chan<- int }

// Source: ../../cmd/compile/internal/types2/builtins.go

// Copyright 2012 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.

// This file implements typechecking of builtin function calls.

package types

import (
	"go/ast"
	"go/constant"
	"go/token"
	. "internal/types/errors"
)

// Code generated by mkbuiltin.go. DO NOT EDIT.

package typecheck

import (
	"cmd/compile/internal/types"
	"cmd/internal/src"
)

// Not inlining this function removes a significant chunk of init code.
//
//go:noinline
func newSig(params, results []*types.Field) *types.Type {
	return types.NewSignature(nil, params, results)
}

func params(tlist ...*types.Type) []*types.Field {
	flist := make([]*types.Field, len(tlist))

// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.

// This file implements typechecking of builtin function calls.

package types2

import (
	"cmd/compile/internal/syntax"
	"go/constant"
	"go/token"
	. "internal/types/errors"
)

// builtin type-checks a call to the built-in specified by id and
// reports whether the call is valid, with *x holding the result;

Jordan Liggitt <******@****.***> 1569333992 -0400

	testenv.MustHaveGoRun(t)
	t.Parallel()

	old, err := os.ReadFile("builtin.go")
	if err != nil {
		t.Fatal(err)
	}

	new, err := testenv.Command(t, testenv.GoToolPath(t), "run", "mkbuiltin.go", "-stdout").Output()
	if err != nil {
		t.Fatal(err)
	}

	if !bytes.Equal(old, new) {
		t.Fatal("builtin.go out of date; run mkbuiltin.go")
	}