go/analysis/passes/vet/vet_test.go - tools - Git at Google

 // +build ignore

 // Copyright 2013 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.

 package main_test

 import (
 	"bytes"
 	"errors"
 	"fmt"
 	"internal/testenv"
 	"io/ioutil"
 	"log"
 	"os"
 	"os/exec"
 	"path/filepath"
 	"regexp"
 	"runtime"
 	"strconv"
 	"strings"
 	"sync"
 	"testing"
 )

 const (
 	dataDir = "testdata"
 	binary  = "./testvet.exe"
 )

 // We implement TestMain so remove the test binary when all is done.
 func TestMain(m *testing.M) {
 	result := m.Run()
 	os.Remove(binary)
 	os.Exit(result)
 }

 var (
 	buildMu sync.Mutex // guards following
 	built   = false    // We have built the binary.
 	failed  = false    // We have failed to build the binary, don't try again.
 )

 func Build(t *testing.T) {
 	buildMu.Lock()
 	defer buildMu.Unlock()
 	if built {
 		return
 	}
 	if failed {
 		t.Skip("cannot run on this environment")
 	}
 	testenv.MustHaveGoBuild(t)
 	cmd := exec.Command(testenv.GoToolPath(t), "build", "-o", binary)
 	output, err := cmd.CombinedOutput()
 	if err != nil {
 		failed = true
 		fmt.Fprintf(os.Stderr, "%s\n", output)
 		t.Fatal(err)
 	}
 	built = true
 }

 func Vet(t *testing.T, files []string) {
 	flags := []string{
 		"-printfuncs=Warn:1,Warnf:1",
 		"-all",
 		"-shadow",
 	}
 	cmd := exec.Command(binary, append(flags, files...)...)
 	errchk(cmd, files, t)
 }

 // TestVet is equivalent to running this:
 // 	go build -o ./testvet
 // 	errorCheck the output of ./testvet -shadow -printfuncs='Warn:1,Warnf:1' testdata/*.go testdata/*.s
 // 	rm ./testvet
 //

 // TestVet tests self-contained files in testdata/*.go.
 //
 // If a file contains assembly or has inter-dependencies, it should be
 // in its own test, like TestVetAsm, TestDivergentPackagesExamples,
 // etc below.
 func TestVet(t *testing.T) {
 	Build(t)
 	t.Parallel()

 	gos, err := filepath.Glob(filepath.Join(dataDir, "*.go"))
 	if err != nil {
 		t.Fatal(err)
 	}
 	wide := runtime.GOMAXPROCS(0)
 	if wide > len(gos) {
 		wide = len(gos)
 	}
 	batch := make([][]string, wide)
 	for i, file := range gos {
 		// The print.go test is run by TestVetPrint.
 		if strings.HasSuffix(file, "print.go") {
 			continue
 		}
 		batch[i%wide] = append(batch[i%wide], file)
 	}
 	for i, files := range batch {
 		if len(files) == 0 {
 			continue
 		}
 		files := files
 		t.Run(fmt.Sprint(i), func(t *testing.T) {
 			t.Parallel()
 			t.Logf("files: %q", files)
 			Vet(t, files)
 		})
 	}
 }

 func TestVetPrint(t *testing.T) {
 	Build(t)
 	file := filepath.Join("testdata", "print.go")
 	cmd := exec.Command(
 		"go", "vet", "-vettool="+binary,
 		"-printf",
 		"-printfuncs=Warn:1,Warnf:1",
 		file,
 	)
 	errchk(cmd, []string{file}, t)
 }

 func TestVetAsm(t *testing.T) {
 	Build(t)

 	asmDir := filepath.Join(dataDir, "asm")
 	gos, err := filepath.Glob(filepath.Join(asmDir, "*.go"))
 	if err != nil {
 		t.Fatal(err)
 	}
 	asms, err := filepath.Glob(filepath.Join(asmDir, "*.s"))
 	if err != nil {
 		t.Fatal(err)
 	}

 	t.Parallel()
 	Vet(t, append(gos, asms...))
 }

 func TestVetDirs(t *testing.T) {
 	t.Parallel()
 	Build(t)
 	for _, dir := range []string{
 		"testingpkg",
 		"divergent",
 		"buildtag",
 		"incomplete", // incomplete examples
 		"cgo",
 	} {
 		dir := dir
 		t.Run(dir, func(t *testing.T) {
 			t.Parallel()
 			gos, err := filepath.Glob(filepath.Join("testdata", dir, "*.go"))
 			if err != nil {
 				t.Fatal(err)
 			}
 			Vet(t, gos)
 		})
 	}
 }

 func errchk(c *exec.Cmd, files []string, t *testing.T) {
 	output, err := c.CombinedOutput()
 	if _, ok := err.(*exec.ExitError); !ok {
 		t.Logf("vet output:\n%s", output)
 		t.Fatal(err)
 	}
 	fullshort := make([]string, 0, len(files)*2)
 	for _, f := range files {
 		fullshort = append(fullshort, f, filepath.Base(f))
 	}
 	err = errorCheck(string(output), false, fullshort...)
 	if err != nil {
 		t.Errorf("error check failed: %s", err)
 	}
 }

 // TestTags verifies that the -tags argument controls which files to check.
 func TestTags(t *testing.T) {
 	t.Parallel()
 	Build(t)
 	for _, tag := range []string{"testtag", "x testtag y", "x,testtag,y"} {
 		tag := tag
 		t.Run(tag, func(t *testing.T) {
 			t.Parallel()
 			t.Logf("-tags=%s", tag)
 			args := []string{
 				"-tags=" + tag,
 				"-v", // We're going to look at the files it examines.
 				"testdata/tagtest",
 			}
 			cmd := exec.Command(binary, args...)
 			output, err := cmd.CombinedOutput()
 			if err != nil {
 				t.Fatal(err)
 			}
 			// file1 has testtag and file2 has !testtag.
 			if !bytes.Contains(output, []byte(filepath.Join("tagtest", "file1.go"))) {
 				t.Error("file1 was excluded, should be included")
 			}
 			if bytes.Contains(output, []byte(filepath.Join("tagtest", "file2.go"))) {
 				t.Error("file2 was included, should be excluded")
 			}
 		})
 	}
 }

 // Issue #21188.
 func TestVetVerbose(t *testing.T) {
 	t.Parallel()
 	Build(t)
 	cmd := exec.Command(binary, "-v", "-all", "testdata/cgo/cgo3.go")
 	out, err := cmd.CombinedOutput()
 	if err != nil {
 		t.Logf("%s", out)
 		t.Error(err)
 	}
 }

 // All declarations below were adapted from test/run.go.

 // errorCheck matches errors in outStr against comments in source files.
 // For each line of the source files which should generate an error,
 // there should be a comment of the form // ERROR "regexp".
 // If outStr has an error for a line which has no such comment,
 // this function will report an error.
 // Likewise if outStr does not have an error for a line which has a comment,
 // or if the error message does not match the <regexp>.
 // The <regexp> syntax is Perl but its best to stick to egrep.
 //
 // Sources files are supplied as fullshort slice.
 // It consists of pairs: full path to source file and it's base name.
 func errorCheck(outStr string, wantAuto bool, fullshort ...string) (err error) {
 	var errs []error
 	out := splitOutput(outStr, wantAuto)
 	// Cut directory name.
 	for i := range out {
 		for j := 0; j < len(fullshort); j += 2 {
 			full, short := fullshort[j], fullshort[j+1]
 			out[i] = strings.ReplaceAll(out[i], full, short)
 		}
 	}

 	var want []wantedError
 	for j := 0; j < len(fullshort); j += 2 {
 		full, short := fullshort[j], fullshort[j+1]
 		want = append(want, wantedErrors(full, short)...)
 	}
 	for _, we := range want {
 		var errmsgs []string
 		if we.auto {
 			errmsgs, out = partitionStrings("<autogenerated>", out)
 		} else {
 			errmsgs, out = partitionStrings(we.prefix, out)
 		}
 		if len(errmsgs) == 0 {
 			errs = append(errs, fmt.Errorf("%s:%d: missing error %q", we.file, we.lineNum, we.reStr))
 			continue
 		}
 		matched := false
 		n := len(out)
 		for _, errmsg := range errmsgs {
 			// Assume errmsg says "file:line: foo".
 			// Cut leading "file:line: " to avoid accidental matching of file name instead of message.
 			text := errmsg
 			if i := strings.Index(text, " "); i >= 0 {
 				text = text[i+1:]
 			}
 			if we.re.MatchString(text) {
 				matched = true
 			} else {
 				out = append(out, errmsg)
 			}
 		}
 		if !matched {
 			errs = append(errs, fmt.Errorf("%s:%d: no match for %#q in:\n\t%s", we.file, we.lineNum, we.reStr, strings.Join(out[n:], "\n\t")))
 			continue
 		}
 	}

 	if len(out) > 0 {
 		errs = append(errs, fmt.Errorf("Unmatched Errors:"))
 		for _, errLine := range out {
 			errs = append(errs, fmt.Errorf("%s", errLine))
 		}
 	}

 	if len(errs) == 0 {
 		return nil
 	}
 	if len(errs) == 1 {
 		return errs[0]
 	}
 	var buf bytes.Buffer
 	fmt.Fprintf(&buf, "\n")
 	for _, err := range errs {
 		fmt.Fprintf(&buf, "%s\n", err.Error())
 	}
 	return errors.New(buf.String())
 }

 func splitOutput(out string, wantAuto bool) []string {
 	// gc error messages continue onto additional lines with leading tabs.
 	// Split the output at the beginning of each line that doesn't begin with a tab.
 	// <autogenerated> lines are impossible to match so those are filtered out.
 	var res []string
 	for _, line := range strings.Split(out, "\n") {
 		line = strings.TrimSuffix(line, "\r") // normalize Windows output
 		if strings.HasPrefix(line, "\t") {
 			res[len(res)-1] += "\n" + line
 		} else if strings.HasPrefix(line, "go tool") || strings.HasPrefix(line, "#") || !wantAuto && strings.HasPrefix(line, "<autogenerated>") {
 			continue
 		} else if strings.TrimSpace(line) != "" {
 			res = append(res, line)
 		}
 	}
 	return res
 }

 // matchPrefix reports whether s starts with file name prefix followed by a :,
 // and possibly preceded by a directory name.
 func matchPrefix(s, prefix string) bool {
 	i := strings.Index(s, ":")
 	if i < 0 {
 		return false
 	}
 	j := strings.LastIndex(s[:i], "/")
 	s = s[j+1:]
 	if len(s) <= len(prefix) || s[:len(prefix)] != prefix {
 		return false
 	}
 	if s[len(prefix)] == ':' {
 		return true
 	}
 	return false
 }

 func partitionStrings(prefix string, strs []string) (matched, unmatched []string) {
 	for _, s := range strs {
 		if matchPrefix(s, prefix) {
 			matched = append(matched, s)
 		} else {
 			unmatched = append(unmatched, s)
 		}
 	}
 	return
 }

 type wantedError struct {
 	reStr   string
 	re      *regexp.Regexp
 	lineNum int
 	auto    bool // match <autogenerated> line
 	file    string
 	prefix  string
 }

 var (
 	errRx       = regexp.MustCompile(`// (?:GC_)?ERROR (.*)`)
 	errAutoRx   = regexp.MustCompile(`// (?:GC_)?ERRORAUTO (.*)`)
 	errQuotesRx = regexp.MustCompile(`"([^"]*)"`)
 	lineRx      = regexp.MustCompile(`LINE(([+-])([0-9]+))?`)
 )

 // wantedErrors parses expected errors from comments in a file.
 func wantedErrors(file, short string) (errs []wantedError) {
 	cache := make(map[string]*regexp.Regexp)

 	src, err := ioutil.ReadFile(file)
 	if err != nil {
 		log.Fatal(err)
 	}
 	for i, line := range strings.Split(string(src), "\n") {
 		lineNum := i + 1
 		if strings.Contains(line, "////") {
 			// double comment disables ERROR
 			continue
 		}
 		var auto bool
 		m := errAutoRx.FindStringSubmatch(line)
 		if m != nil {
 			auto = true
 		} else {
 			m = errRx.FindStringSubmatch(line)
 		}
 		if m == nil {
 			continue
 		}
 		all := m[1]
 		mm := errQuotesRx.FindAllStringSubmatch(all, -1)
 		if mm == nil {
 			log.Fatalf("%s:%d: invalid errchk line: %s", file, lineNum, line)
 		}
 		for _, m := range mm {
 			replacedOnce := false
 			rx := lineRx.ReplaceAllStringFunc(m[1], func(m string) string {
 				if replacedOnce {
 					return m
 				}
 				replacedOnce = true
 				n := lineNum
 				if strings.HasPrefix(m, "LINE+") {
 					delta, _ := strconv.Atoi(m[5:])
 					n += delta
 				} else if strings.HasPrefix(m, "LINE-") {
 					delta, _ := strconv.Atoi(m[5:])
 					n -= delta
 				}
 				return fmt.Sprintf("%s:%d", short, n)
 			})
 			re := cache[rx]
 			if re == nil {
 				var err error
 				re, err = regexp.Compile(rx)
 				if err != nil {
 					log.Fatalf("%s:%d: invalid regexp \"%#q\" in ERROR line: %v", file, lineNum, rx, err)
 				}
 				cache[rx] = re
 			}
 			prefix := fmt.Sprintf("%s:%d", short, lineNum)
 			errs = append(errs, wantedError{
 				reStr:   rx,
 				re:      re,
 				prefix:  prefix,
 				auto:    auto,
 				lineNum: lineNum,
 				file:    short,
 			})
 		}
 	}

 	return
 }
	// +build ignore

	// Copyright 2013 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.

	package main_test

	import (
	"bytes"
	"errors"
	"fmt"
	"internal/testenv"
	"io/ioutil"
	"log"
	"os"
	"os/exec"
	"path/filepath"
	"regexp"
	"runtime"
	"strconv"
	"strings"
	"sync"
	"testing"
	)

	const (
	dataDir = "testdata"
	binary = "./testvet.exe"
	)

	// We implement TestMain so remove the test binary when all is done.
	func TestMain(m *testing.M) {
	result := m.Run()
	os.Remove(binary)
	os.Exit(result)
	}

	var (
	buildMu sync.Mutex // guards following
	built = false // We have built the binary.
	failed = false // We have failed to build the binary, don't try again.
	)

	func Build(t *testing.T) {
	buildMu.Lock()
	defer buildMu.Unlock()
	if built {
	return
	}
	if failed {
	t.Skip("cannot run on this environment")
	}
	testenv.MustHaveGoBuild(t)
	cmd := exec.Command(testenv.GoToolPath(t), "build", "-o", binary)
	output, err := cmd.CombinedOutput()
	if err != nil {
	failed = true
	fmt.Fprintf(os.Stderr, "%s\n", output)
	t.Fatal(err)
	}
	built = true
	}

	func Vet(t *testing.T, files []string) {
	flags := []string{
	"-printfuncs=Warn:1,Warnf:1",
	"-all",
	"-shadow",
	}
	cmd := exec.Command(binary, append(flags, files...)...)
	errchk(cmd, files, t)
	}

	// TestVet is equivalent to running this:
	// go build -o ./testvet
	// errorCheck the output of ./testvet -shadow -printfuncs='Warn:1,Warnf:1' testdata/.go testdata/.s
	// rm ./testvet
	//

	// TestVet tests self-contained files in testdata/*.go.
	//
	// If a file contains assembly or has inter-dependencies, it should be
	// in its own test, like TestVetAsm, TestDivergentPackagesExamples,
	// etc below.
	func TestVet(t *testing.T) {
	Build(t)
	t.Parallel()

	gos, err := filepath.Glob(filepath.Join(dataDir, "*.go"))
	if err != nil {
	t.Fatal(err)
	}
	wide := runtime.GOMAXPROCS(0)
	if wide > len(gos) {
	wide = len(gos)
	}
	batch := make([][]string, wide)
	for i, file := range gos {
	// The print.go test is run by TestVetPrint.
	if strings.HasSuffix(file, "print.go") {
	continue
	}
	batch[i%wide] = append(batch[i%wide], file)
	}
	for i, files := range batch {
	if len(files) == 0 {
	continue
	}
	files := files
	t.Run(fmt.Sprint(i), func(t *testing.T) {
	t.Parallel()
	t.Logf("files: %q", files)
	Vet(t, files)
	})
	}
	}

	func TestVetPrint(t *testing.T) {
	Build(t)
	file := filepath.Join("testdata", "print.go")
	cmd := exec.Command(
	"go", "vet", "-vettool="+binary,
	"-printf",
	"-printfuncs=Warn:1,Warnf:1",
	file,
	)
	errchk(cmd, []string{file}, t)
	}

	func TestVetAsm(t *testing.T) {
	Build(t)

	asmDir := filepath.Join(dataDir, "asm")
	gos, err := filepath.Glob(filepath.Join(asmDir, "*.go"))
	if err != nil {
	t.Fatal(err)
	}
	asms, err := filepath.Glob(filepath.Join(asmDir, "*.s"))
	if err != nil {
	t.Fatal(err)
	}

	t.Parallel()
	Vet(t, append(gos, asms...))
	}

	func TestVetDirs(t *testing.T) {
	t.Parallel()
	Build(t)
	for _, dir := range []string{
	"testingpkg",
	"divergent",
	"buildtag",
	"incomplete", // incomplete examples
	"cgo",
	} {
	dir := dir
	t.Run(dir, func(t *testing.T) {
	t.Parallel()
	gos, err := filepath.Glob(filepath.Join("testdata", dir, "*.go"))
	if err != nil {
	t.Fatal(err)
	}
	Vet(t, gos)
	})
	}
	}

	func errchk(c exec.Cmd, files []string, t testing.T) {
	output, err := c.CombinedOutput()
	if _, ok := err.(*exec.ExitError); !ok {
	t.Logf("vet output:\n%s", output)
	t.Fatal(err)
	}
	fullshort := make([]string, 0, len(files)*2)
	for _, f := range files {
	fullshort = append(fullshort, f, filepath.Base(f))
	}
	err = errorCheck(string(output), false, fullshort...)
	if err != nil {
	t.Errorf("error check failed: %s", err)
	}
	}

	// TestTags verifies that the -tags argument controls which files to check.
	func TestTags(t *testing.T) {
	t.Parallel()
	Build(t)
	for _, tag := range []string{"testtag", "x testtag y", "x,testtag,y"} {
	tag := tag
	t.Run(tag, func(t *testing.T) {
	t.Parallel()
	t.Logf("-tags=%s", tag)
	args := []string{
	"-tags=" + tag,
	"-v", // We're going to look at the files it examines.
	"testdata/tagtest",
	}
	cmd := exec.Command(binary, args...)
	output, err := cmd.CombinedOutput()
	if err != nil {
	t.Fatal(err)
	}
	// file1 has testtag and file2 has !testtag.
	if !bytes.Contains(output, []byte(filepath.Join("tagtest", "file1.go"))) {
	t.Error("file1 was excluded, should be included")
	}
	if bytes.Contains(output, []byte(filepath.Join("tagtest", "file2.go"))) {
	t.Error("file2 was included, should be excluded")
	}
	})
	}
	}

	// Issue #21188.
	func TestVetVerbose(t *testing.T) {
	t.Parallel()
	Build(t)
	cmd := exec.Command(binary, "-v", "-all", "testdata/cgo/cgo3.go")
	out, err := cmd.CombinedOutput()
	if err != nil {
	t.Logf("%s", out)
	t.Error(err)
	}
	}

	// All declarations below were adapted from test/run.go.

	// errorCheck matches errors in outStr against comments in source files.
	// For each line of the source files which should generate an error,
	// there should be a comment of the form // ERROR "regexp".
	// If outStr has an error for a line which has no such comment,
	// this function will report an error.
	// Likewise if outStr does not have an error for a line which has a comment,
	// or if the error message does not match the <regexp>.
	// The <regexp> syntax is Perl but its best to stick to egrep.
	//
	// Sources files are supplied as fullshort slice.
	// It consists of pairs: full path to source file and it's base name.
	func errorCheck(outStr string, wantAuto bool, fullshort ...string) (err error) {
	var errs []error
	out := splitOutput(outStr, wantAuto)
	// Cut directory name.
	for i := range out {
	for j := 0; j < len(fullshort); j += 2 {
	full, short := fullshort[j], fullshort[j+1]
	out[i] = strings.ReplaceAll(out[i], full, short)
	}
	}

	var want []wantedError
	for j := 0; j < len(fullshort); j += 2 {
	full, short := fullshort[j], fullshort[j+1]
	want = append(want, wantedErrors(full, short)...)
	}
	for _, we := range want {
	var errmsgs []string
	if we.auto {
	errmsgs, out = partitionStrings("<autogenerated>", out)
	} else {
	errmsgs, out = partitionStrings(we.prefix, out)
	}
	if len(errmsgs) == 0 {
	errs = append(errs, fmt.Errorf("%s:%d: missing error %q", we.file, we.lineNum, we.reStr))
	continue
	}
	matched := false
	n := len(out)
	for _, errmsg := range errmsgs {
	// Assume errmsg says "file:line: foo".
	// Cut leading "file:line: " to avoid accidental matching of file name instead of message.
	text := errmsg
	if i := strings.Index(text, " "); i >= 0 {
	text = text[i+1:]
	}
	if we.re.MatchString(text) {
	matched = true
	} else {
	out = append(out, errmsg)
	}
	}
	if !matched {
	errs = append(errs, fmt.Errorf("%s:%d: no match for %#q in:\n\t%s", we.file, we.lineNum, we.reStr, strings.Join(out[n:], "\n\t")))
	continue
	}
	}

	if len(out) > 0 {
	errs = append(errs, fmt.Errorf("Unmatched Errors:"))
	for _, errLine := range out {
	errs = append(errs, fmt.Errorf("%s", errLine))
	}
	}

	if len(errs) == 0 {
	return nil
	}
	if len(errs) == 1 {
	return errs[0]
	}
	var buf bytes.Buffer
	fmt.Fprintf(&buf, "\n")
	for _, err := range errs {
	fmt.Fprintf(&buf, "%s\n", err.Error())
	}
	return errors.New(buf.String())
	}

	func splitOutput(out string, wantAuto bool) []string {
	// gc error messages continue onto additional lines with leading tabs.
	// Split the output at the beginning of each line that doesn't begin with a tab.
	// <autogenerated> lines are impossible to match so those are filtered out.
	var res []string
	for _, line := range strings.Split(out, "\n") {
	line = strings.TrimSuffix(line, "\r") // normalize Windows output
	if strings.HasPrefix(line, "\t") {
	res[len(res)-1] += "\n" + line
	} else if strings.HasPrefix(line, "go tool") \|\| strings.HasPrefix(line, "#") \|\| !wantAuto && strings.HasPrefix(line, "<autogenerated>") {
	continue
	} else if strings.TrimSpace(line) != "" {
	res = append(res, line)
	}
	}
	return res
	}

	// matchPrefix reports whether s starts with file name prefix followed by a :,
	// and possibly preceded by a directory name.
	func matchPrefix(s, prefix string) bool {
	i := strings.Index(s, ":")
	if i < 0 {
	return false
	}
	j := strings.LastIndex(s[:i], "/")
	s = s[j+1:]
	if len(s) <= len(prefix) \|\| s[:len(prefix)] != prefix {
	return false
	}
	if s[len(prefix)] == ':' {
	return true
	}
	return false
	}

	func partitionStrings(prefix string, strs []string) (matched, unmatched []string) {
	for _, s := range strs {
	if matchPrefix(s, prefix) {
	matched = append(matched, s)
	} else {
	unmatched = append(unmatched, s)
	}
	}
	return
	}

	type wantedError struct {
	reStr string
	re *regexp.Regexp
	lineNum int
	auto bool // match <autogenerated> line
	file string
	prefix string
	}

	var (
	errRx = regexp.MustCompile(`// (?:GC_)?ERROR (.*)`)
	errAutoRx = regexp.MustCompile(`// (?:GC_)?ERRORAUTO (.*)`)
	errQuotesRx = regexp.MustCompile(`"([^"]*)"`)
	lineRx = regexp.MustCompile(`LINE(([+-])([0-9]+))?`)
	)

	// wantedErrors parses expected errors from comments in a file.
	func wantedErrors(file, short string) (errs []wantedError) {
	cache := make(map[string]*regexp.Regexp)

	src, err := ioutil.ReadFile(file)
	if err != nil {
	log.Fatal(err)
	}
	for i, line := range strings.Split(string(src), "\n") {
	lineNum := i + 1
	if strings.Contains(line, "////") {
	// double comment disables ERROR
	continue
	}
	var auto bool
	m := errAutoRx.FindStringSubmatch(line)
	if m != nil {
	auto = true
	} else {
	m = errRx.FindStringSubmatch(line)
	}
	if m == nil {
	continue
	}
	all := m[1]
	mm := errQuotesRx.FindAllStringSubmatch(all, -1)
	if mm == nil {
	log.Fatalf("%s:%d: invalid errchk line: %s", file, lineNum, line)
	}
	for _, m := range mm {
	replacedOnce := false
	rx := lineRx.ReplaceAllStringFunc(m[1], func(m string) string {
	if replacedOnce {
	return m
	}
	replacedOnce = true
	n := lineNum
	if strings.HasPrefix(m, "LINE+") {
	delta, _ := strconv.Atoi(m[5:])
	n += delta
	} else if strings.HasPrefix(m, "LINE-") {
	delta, _ := strconv.Atoi(m[5:])
	n -= delta
	}
	return fmt.Sprintf("%s:%d", short, n)
	})
	re := cache[rx]
	if re == nil {
	var err error
	re, err = regexp.Compile(rx)
	if err != nil {
	log.Fatalf("%s:%d: invalid regexp \"%#q\" in ERROR line: %v", file, lineNum, rx, err)
	}
	cache[rx] = re
	}
	prefix := fmt.Sprintf("%s:%d", short, lineNum)
	errs = append(errs, wantedError{
	reStr: rx,
	re: re,
	prefix: prefix,
	auto: auto,
	lineNum: lineNum,
	file: short,
	})
	}
	}

	return
	}