close(quit)
	return code, err
}

type exitCodeFilter struct {
	w      io.Writer // Pass through to w
	exitRe *regexp.Regexp
	buf    bytes.Buffer
}

func newExitCodeFilter(w io.Writer) (*exitCodeFilter, string) {
	const exitStr = "exitcode="

	// Build a regexp that matches any prefix of the exit string at the end of
	// the input. We do it this way to avoid assuming anything about the

import (
	"bufio"
	"bytes"
	"encoding/json"
	"fmt"
	"go/ast"
	"go/build"
	"go/parser"
	"go/token"
	"go/types"
	"internal/testenv"
	"io"
	"log"
	"os"
	"os/exec"
	"path/filepath"
	"regexp"
	"runtime"
	"sort"
	"strconv"
	"strings"
	"sync"
	"testing"
)

const verbose = false

func goCmd() string {
	var exeSuffix string
	if runtime.GOOS == "windows" {
		exeSuffix = ".exe"

// It might be at the beginning but it might be in the middle of the printed instruction.
var fileLineRE = regexp.MustCompile(`(?:^|\()(testdata[/\\][\da-z]+\.s:\d+)(?:$|\)|:)`)

// Same as in test/run.go
var (
	errRE       = regexp.MustCompile(`// ERROR ?(.*)`)
	errQuotesRE = regexp.MustCompile(`"([^"]*)"`)
)

func testErrors(t *testing.T, goarch, file string, flags ...string) {

pkg reflect, method (Value) Clear() #55002
pkg reflect, type SliceHeader //deprecated #56906
pkg reflect, type StringHeader //deprecated #56906
pkg regexp, method (*Regexp) MarshalText() ([]uint8, error) #46159
pkg regexp, method (*Regexp) UnmarshalText([]uint8) error #46159
pkg runtime, method (*PanicNilError) Error() string #25448
pkg runtime, method (*PanicNilError) RuntimeError() #25448