tools/src/cmd/test-runner/main.go - tint - Git at Google

 // Copyright 2021 The Tint 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.

 // test-runner runs tint against a number of test shaders checking for expected behavior
 package main

 import (
 	"context"
 	"flag"
 	"fmt"
 	"io/ioutil"
 	"os"
 	"os/exec"
 	"path/filepath"
 	"regexp"
 	"runtime"
 	"sort"
 	"strings"
 	"time"
 	"unicode/utf8"

 	"dawn.googlesource.com/tint/tools/src/fileutils"
 	"dawn.googlesource.com/tint/tools/src/glob"
 	"github.com/fatih/color"
 	"github.com/sergi/go-diff/diffmatchpatch"
 )

 type outputFormat string

 const (
 	testTimeout = 30 * time.Second

 	glsl   = outputFormat("glsl")
 	hlsl   = outputFormat("hlsl")
 	msl    = outputFormat("msl")
 	spvasm = outputFormat("spvasm")
 	wgsl   = outputFormat("wgsl")
 )

 func main() {
 	if err := run(); err != nil {
 		fmt.Println(err)
 		os.Exit(1)
 	}
 }

 func showUsage() {
 	fmt.Println(`
 test-runner runs tint against a number of test shaders checking for expected behavior

 usage:
   test-runner [flags...] <executable> [<directory>]

   <executable> the path to the tint executable
   <directory>  the root directory of the test files

 optional flags:`)
 	flag.PrintDefaults()
 	fmt.Println(``)
 	os.Exit(1)
 }

 func run() error {
 	var formatList, filter, dxcPath, xcrunPath string
 	var maxFilenameColumnWidth int
 	numCPU := runtime.NumCPU()
 	fxc, verbose, generateExpected, generateSkip := false, false, false, false
 	flag.StringVar(&formatList, "format", "wgsl,spvasm,msl,hlsl", "comma separated list of formats to emit. Possible values are: all, wgsl, spvasm, msl, hlsl, glsl")
 	flag.StringVar(&filter, "filter", "**.wgsl, **.spvasm, **.spv", "comma separated list of glob patterns for test files")
 	flag.StringVar(&dxcPath, "dxc", "", "path to DXC executable for validating HLSL output")
 	flag.StringVar(&xcrunPath, "xcrun", "", "path to xcrun executable for validating MSL output")
 	flag.BoolVar(&fxc, "fxc", false, "validate with FXC instead of DXC")
 	flag.BoolVar(&verbose, "verbose", false, "print all run tests, including rows that all pass")
 	flag.BoolVar(&generateExpected, "generate-expected", false, "create or update all expected outputs")
 	flag.BoolVar(&generateSkip, "generate-skip", false, "create or update all expected outputs that fail with SKIP")
 	flag.IntVar(&numCPU, "j", numCPU, "maximum number of concurrent threads to run tests")
 	flag.IntVar(&maxFilenameColumnWidth, "filename-column-width", 0, "maximum width of the filename column")
 	flag.Usage = showUsage
 	flag.Parse()

 	args := flag.Args()
 	if len(args) == 0 {
 		showUsage()
 	}

 	// executable path is the first argument
 	exe, args := args[0], args[1:]

 	// (optional) target directory is the second argument
 	dir := "."
 	if len(args) > 0 {
 		dir, args = args[0], args[1:]
 	}

 	// Check the executable can be found and actually is executable
 	if !fileutils.IsExe(exe) {
 		return fmt.Errorf("'%s' not found or is not executable", exe)
 	}
 	exe, err := filepath.Abs(exe)
 	if err != nil {
 		return err
 	}

 	// Allow using '/' in the filter on Windows
 	filter = strings.ReplaceAll(filter, "/", string(filepath.Separator))

 	// Split the --filter flag up by ',', trimming any whitespace at the start and end
 	globIncludes := strings.Split(filter, ",")
 	for i, s := range globIncludes {
 		s = filepath.ToSlash(s) // Replace '\' with '/'
 		globIncludes[i] = `"` + strings.TrimSpace(s) + `"`
 	}

 	// Glob the files to test
 	files, err := glob.Scan(dir, glob.MustParseConfig(`{
 		"paths": [
 			{
 				"include": [ `+strings.Join(globIncludes, ",")+` ]
 			},
 			{
 				"exclude": [
 					"**.expected.wgsl",
 					"**.expected.spvasm",
 					"**.expected.msl",
 					"**.expected.hlsl"
 				]
 			}
 		]
 	}`))
 	if err != nil {
 		return fmt.Errorf("Failed to glob files: %w", err)
 	}

 	// Ensure the files are sorted (globbing should do this, but why not)
 	sort.Strings(files)

 	// Parse --format into a list of outputFormat
 	formats := []outputFormat{}
 	if formatList == "all" {
 		formats = []outputFormat{wgsl, spvasm, msl, hlsl, glsl}
 	} else {
 		for _, f := range strings.Split(formatList, ",") {
 			switch strings.TrimSpace(f) {
 			case "wgsl":
 				formats = append(formats, wgsl)
 			case "spvasm":
 				formats = append(formats, spvasm)
 			case "msl":
 				formats = append(formats, msl)
 			case "hlsl":
 				formats = append(formats, hlsl)
 			case "glsl":
 				formats = append(formats, glsl)
 			default:
 				return fmt.Errorf("unknown format '%s'", f)
 			}
 		}
 	}

 	defaultMSLExe := "xcrun"
 	if runtime.GOOS == "windows" {
 		defaultMSLExe = "metal.exe"
 	}

 	// If explicit verification compilers have been specified, check they exist.
 	// Otherwise, look on PATH for them, but don't error if they cannot be found.
 	for _, tool := range []struct {
 		name string
 		lang string
 		path *string
 	}{
 		{"dxc", "hlsl", &dxcPath},
 		{defaultMSLExe, "msl", &xcrunPath},
 	} {
 		if *tool.path == "" {
 			p, err := exec.LookPath(tool.name)
 			if err == nil && fileutils.IsExe(p) {
 				*tool.path = p
 			}
 		} else if !fileutils.IsExe(*tool.path) {
 			return fmt.Errorf("%v not found at '%v'", tool.name, *tool.path)
 		}

 		color.Set(color.FgCyan)
 		fmt.Printf("%-4s", tool.lang)
 		color.Unset()
 		fmt.Printf(" validation ")
 		if *tool.path != "" || (fxc && tool.lang == "hlsl") {
 			color.Set(color.FgGreen)
 			tool_path := *tool.path
 			if fxc && tool.lang == "hlsl" {
 				tool_path = "Tint will use FXC dll in PATH"
 			}
 			fmt.Printf("ENABLED (" + tool_path + ")")
 		} else {
 			color.Set(color.FgRed)
 			fmt.Printf("DISABLED")
 		}
 		color.Unset()
 		fmt.Println()
 	}
 	fmt.Println()

 	// Build the list of results.
 	// These hold the chans used to report the job results.
 	results := make([]map[outputFormat]chan status, len(files))
 	for i := range files {
 		fileResults := map[outputFormat]chan status{}
 		for _, format := range formats {
 			fileResults[format] = make(chan status, 1)
 		}
 		results[i] = fileResults
 	}

 	pendingJobs := make(chan job, 256)

 	// Spawn numCPU job runners...
 	for cpu := 0; cpu < numCPU; cpu++ {
 		go func() {
 			for job := range pendingJobs {
 				job.run(dir, exe, fxc, dxcPath, xcrunPath, generateExpected, generateSkip)
 			}
 		}()
 	}

 	// Issue the jobs...
 	go func() {
 		for i, file := range files { // For each test file...
 			file := filepath.Join(dir, file)
 			flags := parseFlags(file)
 			for _, format := range formats { // For each output format...
 				pendingJobs <- job{
 					file:   file,
 					flags:  flags,
 					format: format,
 					result: results[i][format],
 				}
 			}
 		}
 		close(pendingJobs)
 	}()

 	type failure struct {
 		file   string
 		format outputFormat
 		err    error
 	}

 	type stats struct {
 		numTests, numPass, numSkip, numFail int
 		timeTaken                           time.Duration
 	}

 	// Statistics per output format
 	statsByFmt := map[outputFormat]*stats{}
 	for _, format := range formats {
 		statsByFmt[format] = &stats{}
 	}

 	// Print the table of file x format and gather per-format stats
 	failures := []failure{}
 	filenameColumnWidth := maxStringLen(files)
 	if maxFilenameColumnWidth > 0 {
 		filenameColumnWidth = maxFilenameColumnWidth
 	}

 	red := color.New(color.FgRed)
 	green := color.New(color.FgGreen)
 	yellow := color.New(color.FgYellow)
 	cyan := color.New(color.FgCyan)

 	printFormatsHeader := func() {
 		fmt.Printf(strings.Repeat(" ", filenameColumnWidth))
 		fmt.Printf(" ┃ ")
 		for _, format := range formats {
 			cyan.Printf(alignCenter(format, formatWidth(format)))
 			fmt.Printf(" │ ")
 		}
 		fmt.Println()
 	}
 	printHorizontalLine := func() {
 		fmt.Printf(strings.Repeat("━", filenameColumnWidth))
 		fmt.Printf("━╋━")
 		for _, format := range formats {
 			fmt.Printf(strings.Repeat("━", formatWidth(format)))
 			fmt.Printf("━┿━")
 		}
 		fmt.Println()
 	}

 	fmt.Println()

 	printFormatsHeader()
 	printHorizontalLine()

 	for i, file := range files {
 		results := results[i]

 		row := &strings.Builder{}
 		rowAllPassed := true

 		filenameLength := utf8.RuneCountInString(file)
 		shortFile := file
 		if filenameLength > filenameColumnWidth {
 			shortFile = "..." + file[filenameLength-filenameColumnWidth+3:]
 		}

 		fmt.Fprintf(row, alignRight(shortFile, filenameColumnWidth))
 		fmt.Fprintf(row, " ┃ ")
 		for _, format := range formats {
 			columnWidth := formatWidth(format)
 			result := <-results[format]
 			stats := statsByFmt[format]
 			stats.numTests++
 			stats.timeTaken += result.timeTaken
 			if err := result.err; err != nil {
 				failures = append(failures, failure{
 					file: file, format: format, err: err,
 				})
 			}
 			switch result.code {
 			case pass:
 				green.Fprintf(row, alignCenter("PASS", columnWidth))
 				stats.numPass++
 			case fail:
 				red.Fprintf(row, alignCenter("FAIL", columnWidth))
 				rowAllPassed = false
 				stats.numFail++
 			case skip:
 				yellow.Fprintf(row, alignCenter("SKIP", columnWidth))
 				rowAllPassed = false
 				stats.numSkip++
 			default:
 				fmt.Fprintf(row, alignCenter(result.code, columnWidth))
 				rowAllPassed = false
 			}
 			fmt.Fprintf(row, " │ ")
 		}

 		if verbose || !rowAllPassed {
 			fmt.Fprintln(color.Output, row)
 		}
 	}

 	printHorizontalLine()
 	printFormatsHeader()
 	printHorizontalLine()
 	printStat := func(col *color.Color, name string, num func(*stats) int) {
 		row := &strings.Builder{}
 		anyNonZero := false
 		for _, format := range formats {
 			columnWidth := formatWidth(format)
 			count := num(statsByFmt[format])
 			if count > 0 {
 				col.Fprintf(row, alignLeft(count, columnWidth))
 				anyNonZero = true
 			} else {
 				fmt.Fprintf(row, alignLeft(count, columnWidth))
 			}
 			fmt.Fprintf(row, " │ ")
 		}

 		if !anyNonZero {
 			return
 		}
 		col.Printf(alignRight(name, filenameColumnWidth))
 		fmt.Printf(" ┃ ")
 		fmt.Fprintln(color.Output, row)

 		col.Printf(strings.Repeat(" ", filenameColumnWidth))
 		fmt.Printf(" ┃ ")
 		for _, format := range formats {
 			columnWidth := formatWidth(format)
 			stats := statsByFmt[format]
 			count := num(stats)
 			percent := percentage(count, stats.numTests)
 			if count > 0 {
 				col.Print(alignRight(percent, columnWidth))
 			} else {
 				fmt.Print(alignRight(percent, columnWidth))
 			}
 			fmt.Printf(" │ ")
 		}
 		fmt.Println()
 	}
 	printStat(green, "PASS", func(s *stats) int { return s.numPass })
 	printStat(yellow, "SKIP", func(s *stats) int { return s.numSkip })
 	printStat(red, "FAIL", func(s *stats) int { return s.numFail })

 	cyan.Printf(alignRight("TIME", filenameColumnWidth))
 	fmt.Printf(" ┃ ")
 	for _, format := range formats {
 		timeTaken := printDuration(statsByFmt[format].timeTaken)
 		cyan.Printf(alignLeft(timeTaken, formatWidth(format)))
 		fmt.Printf(" │ ")
 	}
 	fmt.Println()

 	for _, f := range failures {
 		color.Set(color.FgBlue)
 		fmt.Printf("%s ", f.file)
 		color.Set(color.FgCyan)
 		fmt.Printf("%s ", f.format)
 		color.Set(color.FgRed)
 		fmt.Println("FAIL")
 		color.Unset()
 		fmt.Println(indent(f.err.Error(), 4))
 	}
 	if len(failures) > 0 {
 		fmt.Println()
 	}

 	allStats := stats{}
 	for _, format := range formats {
 		stats := statsByFmt[format]
 		allStats.numTests += stats.numTests
 		allStats.numPass += stats.numPass
 		allStats.numSkip += stats.numSkip
 		allStats.numFail += stats.numFail
 	}

 	fmt.Printf("%d tests run", allStats.numTests)
 	if allStats.numPass > 0 {
 		fmt.Printf(", ")
 		color.Set(color.FgGreen)
 		fmt.Printf("%d tests pass", allStats.numPass)
 		color.Unset()
 	} else {
 		fmt.Printf(", %d tests pass", allStats.numPass)
 	}
 	if allStats.numSkip > 0 {
 		fmt.Printf(", ")
 		color.Set(color.FgYellow)
 		fmt.Printf("%d tests skipped", allStats.numSkip)
 		color.Unset()
 	} else {
 		fmt.Printf(", %d tests skipped", allStats.numSkip)
 	}
 	if allStats.numFail > 0 {
 		fmt.Printf(", ")
 		color.Set(color.FgRed)
 		fmt.Printf("%d tests failed", allStats.numFail)
 		color.Unset()
 	} else {
 		fmt.Printf(", %d tests failed", allStats.numFail)
 	}
 	fmt.Println()
 	fmt.Println()

 	if allStats.numFail > 0 {
 		os.Exit(1)
 	}

 	return nil
 }

 // Structures to hold the results of the tests
 type statusCode string

 const (
 	fail statusCode = "FAIL"
 	pass statusCode = "PASS"
 	skip statusCode = "SKIP"
 )

 type status struct {
 	code      statusCode
 	err       error
 	timeTaken time.Duration
 }

 type job struct {
 	file   string
 	flags  []string
 	format outputFormat
 	result chan status
 }

 func (j job) run(wd, exe string, fxc bool, dxcPath, xcrunPath string, generateExpected, generateSkip bool) {
 	j.result <- func() status {
 		// Is there an expected output?
 		expected := loadExpectedFile(j.file, j.format)
 		skipped := false
 		if strings.HasPrefix(expected, "SKIP") { // Special SKIP token
 			skipped = true
 		}

 		expected = strings.ReplaceAll(expected, "\r\n", "\n")

 		file, err := filepath.Rel(wd, j.file)
 		if err != nil {
 			file = j.file
 		}

 		// Make relative paths use forward slash separators (on Windows) so that paths in tint
 		// output match expected output that contain errors
 		file = strings.ReplaceAll(file, `\`, `/`)

 		args := []string{
 			file,
 			"--format", string(j.format),
 		}

 		// Can we validate?
 		validate := false
 		switch j.format {
 		case wgsl:
 			validate = true
 		case spvasm, glsl:
 			args = append(args, "--validate") // spirv-val and glslang are statically linked, always available
 			validate = true
 		case hlsl:
 			if fxc {
 				args = append(args, "--fxc")
 				validate = true
 			} else if dxcPath != "" {
 				args = append(args, "--dxc", dxcPath)
 				validate = true
 			}
 		case msl:
 			if xcrunPath != "" {
 				args = append(args, "--xcrun", xcrunPath)
 				validate = true
 			}
 		}

 		args = append(args, j.flags...)

 		// Invoke the compiler...
 		start := time.Now()
 		ok, out := invoke(wd, exe, args...)
 		timeTaken := time.Since(start)

 		out = strings.ReplaceAll(out, "\r\n", "\n")
 		matched := expected == "" || expected == out

 		if ok && generateExpected && (validate || !skipped) {
 			saveExpectedFile(j.file, j.format, out)
 			matched = true
 		}

 		switch {
 		case ok && matched:
 			// Test passed
 			return status{code: pass, timeTaken: timeTaken}

 			//       --- Below this point the test has failed ---

 		case skipped:
 			if generateSkip {
 				saveExpectedFile(j.file, j.format, "SKIP: FAILED\n\n"+out)
 			}
 			return status{code: skip, timeTaken: timeTaken}

 		case !ok:
 			// Compiler returned non-zero exit code
 			if generateSkip {
 				saveExpectedFile(j.file, j.format, "SKIP: FAILED\n\n"+out)
 			}
 			err := fmt.Errorf("%s", out)
 			return status{code: fail, err: err, timeTaken: timeTaken}

 		default:
 			// Compiler returned zero exit code, or output was not as expected
 			if generateSkip {
 				saveExpectedFile(j.file, j.format, "SKIP: FAILED\n\n"+out)
 			}

 			// Expected output did not match
 			dmp := diffmatchpatch.New()
 			diff := dmp.DiffPrettyText(dmp.DiffMain(expected, out, true))
 			err := fmt.Errorf(`Output was not as expected

 --------------------------------------------------------------------------------
 -- Expected:                                                                  --
 --------------------------------------------------------------------------------
 %s

 --------------------------------------------------------------------------------
 -- Got:                                                                       --
 --------------------------------------------------------------------------------
 %s

 --------------------------------------------------------------------------------
 -- Diff:                                                                      --
 --------------------------------------------------------------------------------
 %s`,
 				expected, out, diff)
 			return status{code: fail, err: err, timeTaken: timeTaken}
 		}
 	}()
 }

 // loadExpectedFile loads the expected output file for the test file at 'path'
 // and the output format 'format'. If the file does not exist, or cannot be
 // read, then an empty string is returned.
 func loadExpectedFile(path string, format outputFormat) string {
 	content, err := ioutil.ReadFile(expectedFilePath(path, format))
 	if err != nil {
 		return ""
 	}
 	return string(content)
 }

 // saveExpectedFile writes the expected output file for the test file at 'path'
 // and the output format 'format', with the content 'content'.
 func saveExpectedFile(path string, format outputFormat, content string) error {
 	// Don't generate expected results for certain directories that contain
 	// large corpora of tests for which the generated code is uninteresting.
 	for _, exclude := range []string{"/test/unittest/", "/test/vk-gl-cts/"} {
 		if strings.Contains(path, filepath.FromSlash(exclude)) {
 			return nil
 		}
 	}
 	return ioutil.WriteFile(expectedFilePath(path, format), []byte(content), 0666)
 }

 // expectedFilePath returns the expected output file path for the test file at
 // 'path' and the output format 'format'.
 func expectedFilePath(path string, format outputFormat) string {
 	return path + ".expected." + string(format)
 }

 // indent returns the string 's' indented with 'n' whitespace characters
 func indent(s string, n int) string {
 	tab := strings.Repeat(" ", n)
 	return tab + strings.ReplaceAll(s, "\n", "\n"+tab)
 }

 // alignLeft returns the string of 'val' padded so that it is aligned left in
 // a column of the given width
 func alignLeft(val interface{}, width int) string {
 	s := fmt.Sprint(val)
 	padding := width - utf8.RuneCountInString(s)
 	if padding < 0 {
 		return s
 	}
 	return s + strings.Repeat(" ", padding)
 }

 // alignCenter returns the string of 'val' padded so that it is centered in a
 // column of the given width.
 func alignCenter(val interface{}, width int) string {
 	s := fmt.Sprint(val)
 	padding := width - utf8.RuneCountInString(s)
 	if padding < 0 {
 		return s
 	}
 	return strings.Repeat(" ", padding/2) + s + strings.Repeat(" ", (padding+1)/2)
 }

 // alignRight returns the string of 'val' padded so that it is aligned right in
 // a column of the given width
 func alignRight(val interface{}, width int) string {
 	s := fmt.Sprint(val)
 	padding := width - utf8.RuneCountInString(s)
 	if padding < 0 {
 		return s
 	}
 	return strings.Repeat(" ", padding) + s
 }

 // maxStringLen returns the maximum number of runes found in all the strings in
 // 'l'
 func maxStringLen(l []string) int {
 	max := 0
 	for _, s := range l {
 		if c := utf8.RuneCountInString(s); c > max {
 			max = c
 		}
 	}
 	return max
 }

 // formatWidth returns the width in runes for the outputFormat column 'b'
 func formatWidth(b outputFormat) int {
 	const min = 6
 	c := utf8.RuneCountInString(string(b))
 	if c < min {
 		return min
 	}
 	return c
 }

 // percentage returns the percentage of n out of total as a string
 func percentage(n, total int) string {
 	if total == 0 {
 		return "-"
 	}
 	f := float64(n) / float64(total)
 	return fmt.Sprintf("%.1f%c", f*100.0, '%')
 }

 // invoke runs the executable 'exe' with the provided arguments.
 func invoke(wd, exe string, args ...string) (ok bool, output string) {
 	ctx, cancel := context.WithTimeout(context.Background(), testTimeout)
 	defer cancel()

 	cmd := exec.CommandContext(ctx, exe, args...)
 	cmd.Dir = wd
 	out, err := cmd.CombinedOutput()
 	str := string(out)
 	if err != nil {
 		if ctx.Err() == context.DeadlineExceeded {
 			return false, fmt.Sprintf("test timed out after %v", testTimeout)
 		}
 		if str != "" {
 			return false, str
 		}
 		return false, err.Error()
 	}
 	return true, str
 }

 var reFlags = regexp.MustCompile(` *\/\/ *flags:(.*)\n`)

 // parseFlags looks for a `// flags:` header at the start of the file with the
 // given path, returning each of the space delimited tokens that follow for the
 // line
 func parseFlags(path string) []string {
 	content, err := ioutil.ReadFile(path)
 	if err != nil {
 		return nil
 	}
 	header := strings.SplitN(string(content), "\n", 1)[0]
 	m := reFlags.FindStringSubmatch(header)
 	if len(m) != 2 {
 		return nil
 	}
 	return strings.Split(m[1], " ")
 }

 func printDuration(d time.Duration) string {
 	sec := int(d.Seconds())
 	min := int(sec) / 60
 	hour := min / 60
 	min -= hour * 60
 	sec -= min * 60
 	sb := &strings.Builder{}
 	if hour > 0 {
 		fmt.Fprintf(sb, "%dh", hour)
 	}
 	if min > 0 {
 		fmt.Fprintf(sb, "%dm", min)
 	}
 	if sec > 0 {
 		fmt.Fprintf(sb, "%ds", sec)
 	}
 	return sb.String()
 }
	// Copyright 2021 The Tint 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.

	// test-runner runs tint against a number of test shaders checking for expected behavior
	package main

	import (
	"context"
	"flag"
	"fmt"
	"io/ioutil"
	"os"
	"os/exec"
	"path/filepath"
	"regexp"
	"runtime"
	"sort"
	"strings"
	"time"
	"unicode/utf8"

	"dawn.googlesource.com/tint/tools/src/fileutils"
	"dawn.googlesource.com/tint/tools/src/glob"
	"github.com/fatih/color"
	"github.com/sergi/go-diff/diffmatchpatch"
	)

	type outputFormat string

	const (
	testTimeout = 30 * time.Second

	glsl = outputFormat("glsl")
	hlsl = outputFormat("hlsl")
	msl = outputFormat("msl")
	spvasm = outputFormat("spvasm")
	wgsl = outputFormat("wgsl")
	)

	func main() {
	if err := run(); err != nil {
	fmt.Println(err)
	os.Exit(1)
	}
	}

	func showUsage() {
	fmt.Println(`
	test-runner runs tint against a number of test shaders checking for expected behavior

	usage:
	test-runner [flags...] <executable> [<directory>]

	<executable> the path to the tint executable
	<directory> the root directory of the test files

	optional flags:`)
	flag.PrintDefaults()
	fmt.Println(``)
	os.Exit(1)
	}

	func run() error {
	var formatList, filter, dxcPath, xcrunPath string
	var maxFilenameColumnWidth int
	numCPU := runtime.NumCPU()
	fxc, verbose, generateExpected, generateSkip := false, false, false, false
	flag.StringVar(&formatList, "format", "wgsl,spvasm,msl,hlsl", "comma separated list of formats to emit. Possible values are: all, wgsl, spvasm, msl, hlsl, glsl")
	flag.StringVar(&filter, "filter", ".wgsl, .spvasm, **.spv", "comma separated list of glob patterns for test files")
	flag.StringVar(&dxcPath, "dxc", "", "path to DXC executable for validating HLSL output")
	flag.StringVar(&xcrunPath, "xcrun", "", "path to xcrun executable for validating MSL output")
	flag.BoolVar(&fxc, "fxc", false, "validate with FXC instead of DXC")
	flag.BoolVar(&verbose, "verbose", false, "print all run tests, including rows that all pass")
	flag.BoolVar(&generateExpected, "generate-expected", false, "create or update all expected outputs")
	flag.BoolVar(&generateSkip, "generate-skip", false, "create or update all expected outputs that fail with SKIP")
	flag.IntVar(&numCPU, "j", numCPU, "maximum number of concurrent threads to run tests")
	flag.IntVar(&maxFilenameColumnWidth, "filename-column-width", 0, "maximum width of the filename column")
	flag.Usage = showUsage
	flag.Parse()

	args := flag.Args()
	if len(args) == 0 {
	showUsage()
	}

	// executable path is the first argument
	exe, args := args[0], args[1:]

	// (optional) target directory is the second argument
	dir := "."
	if len(args) > 0 {
	dir, args = args[0], args[1:]
	}

	// Check the executable can be found and actually is executable
	if !fileutils.IsExe(exe) {
	return fmt.Errorf("'%s' not found or is not executable", exe)
	}
	exe, err := filepath.Abs(exe)
	if err != nil {
	return err
	}

	// Allow using '/' in the filter on Windows
	filter = strings.ReplaceAll(filter, "/", string(filepath.Separator))

	// Split the --filter flag up by ',', trimming any whitespace at the start and end
	globIncludes := strings.Split(filter, ",")
	for i, s := range globIncludes {
	s = filepath.ToSlash(s) // Replace '\' with '/'
	globIncludes[i] = `"` + strings.TrimSpace(s) + `"`
	}

	// Glob the files to test
	files, err := glob.Scan(dir, glob.MustParseConfig(`{
	"paths": [
	{
	"include": [ `+strings.Join(globIncludes, ",")+` ]
	},
	{
	"exclude": [
	"**.expected.wgsl",
	"**.expected.spvasm",
	"**.expected.msl",
	"**.expected.hlsl"
	]
	}
	]
	}`))
	if err != nil {
	return fmt.Errorf("Failed to glob files: %w", err)
	}

	// Ensure the files are sorted (globbing should do this, but why not)
	sort.Strings(files)

	// Parse --format into a list of outputFormat
	formats := []outputFormat{}
	if formatList == "all" {
	formats = []outputFormat{wgsl, spvasm, msl, hlsl, glsl}
	} else {
	for _, f := range strings.Split(formatList, ",") {
	switch strings.TrimSpace(f) {
	case "wgsl":
	formats = append(formats, wgsl)
	case "spvasm":
	formats = append(formats, spvasm)
	case "msl":
	formats = append(formats, msl)
	case "hlsl":
	formats = append(formats, hlsl)
	case "glsl":
	formats = append(formats, glsl)
	default:
	return fmt.Errorf("unknown format '%s'", f)
	}
	}
	}

	defaultMSLExe := "xcrun"
	if runtime.GOOS == "windows" {
	defaultMSLExe = "metal.exe"
	}

	// If explicit verification compilers have been specified, check they exist.
	// Otherwise, look on PATH for them, but don't error if they cannot be found.
	for _, tool := range []struct {
	name string
	lang string
	path *string
	}{
	{"dxc", "hlsl", &dxcPath},
	{defaultMSLExe, "msl", &xcrunPath},
	} {
	if *tool.path == "" {
	p, err := exec.LookPath(tool.name)
	if err == nil && fileutils.IsExe(p) {
	*tool.path = p
	}
	} else if !fileutils.IsExe(*tool.path) {
	return fmt.Errorf("%v not found at '%v'", tool.name, *tool.path)
	}

	color.Set(color.FgCyan)
	fmt.Printf("%-4s", tool.lang)
	color.Unset()
	fmt.Printf(" validation ")
	if *tool.path != "" \|\| (fxc && tool.lang == "hlsl") {
	color.Set(color.FgGreen)
	tool_path := *tool.path
	if fxc && tool.lang == "hlsl" {
	tool_path = "Tint will use FXC dll in PATH"
	}
	fmt.Printf("ENABLED (" + tool_path + ")")
	} else {
	color.Set(color.FgRed)
	fmt.Printf("DISABLED")
	}
	color.Unset()
	fmt.Println()
	}
	fmt.Println()

	// Build the list of results.
	// These hold the chans used to report the job results.
	results := make([]map[outputFormat]chan status, len(files))
	for i := range files {
	fileResults := map[outputFormat]chan status{}
	for _, format := range formats {
	fileResults[format] = make(chan status, 1)
	}
	results[i] = fileResults
	}

	pendingJobs := make(chan job, 256)

	// Spawn numCPU job runners...
	for cpu := 0; cpu < numCPU; cpu++ {
	go func() {
	for job := range pendingJobs {
	job.run(dir, exe, fxc, dxcPath, xcrunPath, generateExpected, generateSkip)
	}
	}()
	}

	// Issue the jobs...
	go func() {
	for i, file := range files { // For each test file...
	file := filepath.Join(dir, file)
	flags := parseFlags(file)
	for _, format := range formats { // For each output format...
	pendingJobs <- job{
	file: file,
	flags: flags,
	format: format,
	result: results[i][format],
	}
	}
	}
	close(pendingJobs)
	}()

	type failure struct {
	file string
	format outputFormat
	err error
	}

	type stats struct {
	numTests, numPass, numSkip, numFail int
	timeTaken time.Duration
	}

	// Statistics per output format
	statsByFmt := map[outputFormat]*stats{}
	for _, format := range formats {
	statsByFmt[format] = &stats{}
	}

	// Print the table of file x format and gather per-format stats
	failures := []failure{}
	filenameColumnWidth := maxStringLen(files)
	if maxFilenameColumnWidth > 0 {
	filenameColumnWidth = maxFilenameColumnWidth
	}

	red := color.New(color.FgRed)
	green := color.New(color.FgGreen)
	yellow := color.New(color.FgYellow)
	cyan := color.New(color.FgCyan)

	printFormatsHeader := func() {
	fmt.Printf(strings.Repeat(" ", filenameColumnWidth))
	fmt.Printf(" ┃ ")
	for _, format := range formats {
	cyan.Printf(alignCenter(format, formatWidth(format)))
	fmt.Printf(" │ ")
	}
	fmt.Println()
	}
	printHorizontalLine := func() {
	fmt.Printf(strings.Repeat("━", filenameColumnWidth))
	fmt.Printf("━╋━")
	for _, format := range formats {
	fmt.Printf(strings.Repeat("━", formatWidth(format)))
	fmt.Printf("━┿━")
	}
	fmt.Println()
	}

	fmt.Println()

	printFormatsHeader()
	printHorizontalLine()

	for i, file := range files {
	results := results[i]

	row := &strings.Builder{}
	rowAllPassed := true

	filenameLength := utf8.RuneCountInString(file)
	shortFile := file
	if filenameLength > filenameColumnWidth {
	shortFile = "..." + file[filenameLength-filenameColumnWidth+3:]
	}

	fmt.Fprintf(row, alignRight(shortFile, filenameColumnWidth))
	fmt.Fprintf(row, " ┃ ")
	for _, format := range formats {
	columnWidth := formatWidth(format)
	result := <-results[format]
	stats := statsByFmt[format]
	stats.numTests++
	stats.timeTaken += result.timeTaken
	if err := result.err; err != nil {
	failures = append(failures, failure{
	file: file, format: format, err: err,
	})
	}
	switch result.code {
	case pass:
	green.Fprintf(row, alignCenter("PASS", columnWidth))
	stats.numPass++
	case fail:
	red.Fprintf(row, alignCenter("FAIL", columnWidth))
	rowAllPassed = false
	stats.numFail++
	case skip:
	yellow.Fprintf(row, alignCenter("SKIP", columnWidth))
	rowAllPassed = false
	stats.numSkip++
	default:
	fmt.Fprintf(row, alignCenter(result.code, columnWidth))
	rowAllPassed = false
	}
	fmt.Fprintf(row, " │ ")
	}

	if verbose \|\| !rowAllPassed {
	fmt.Fprintln(color.Output, row)
	}
	}

	printHorizontalLine()
	printFormatsHeader()
	printHorizontalLine()
	printStat := func(col color.Color, name string, num func(stats) int) {
	row := &strings.Builder{}
	anyNonZero := false
	for _, format := range formats {
	columnWidth := formatWidth(format)
	count := num(statsByFmt[format])
	if count > 0 {
	col.Fprintf(row, alignLeft(count, columnWidth))
	anyNonZero = true
	} else {
	fmt.Fprintf(row, alignLeft(count, columnWidth))
	}
	fmt.Fprintf(row, " │ ")
	}

	if !anyNonZero {
	return
	}
	col.Printf(alignRight(name, filenameColumnWidth))
	fmt.Printf(" ┃ ")
	fmt.Fprintln(color.Output, row)

	col.Printf(strings.Repeat(" ", filenameColumnWidth))
	fmt.Printf(" ┃ ")
	for _, format := range formats {
	columnWidth := formatWidth(format)
	stats := statsByFmt[format]
	count := num(stats)
	percent := percentage(count, stats.numTests)
	if count > 0 {
	col.Print(alignRight(percent, columnWidth))
	} else {
	fmt.Print(alignRight(percent, columnWidth))
	}
	fmt.Printf(" │ ")
	}
	fmt.Println()
	}
	printStat(green, "PASS", func(s *stats) int { return s.numPass })
	printStat(yellow, "SKIP", func(s *stats) int { return s.numSkip })
	printStat(red, "FAIL", func(s *stats) int { return s.numFail })

	cyan.Printf(alignRight("TIME", filenameColumnWidth))
	fmt.Printf(" ┃ ")
	for _, format := range formats {
	timeTaken := printDuration(statsByFmt[format].timeTaken)
	cyan.Printf(alignLeft(timeTaken, formatWidth(format)))
	fmt.Printf(" │ ")
	}
	fmt.Println()

	for _, f := range failures {
	color.Set(color.FgBlue)
	fmt.Printf("%s ", f.file)
	color.Set(color.FgCyan)
	fmt.Printf("%s ", f.format)
	color.Set(color.FgRed)
	fmt.Println("FAIL")
	color.Unset()
	fmt.Println(indent(f.err.Error(), 4))
	}
	if len(failures) > 0 {
	fmt.Println()
	}

	allStats := stats{}
	for _, format := range formats {
	stats := statsByFmt[format]
	allStats.numTests += stats.numTests
	allStats.numPass += stats.numPass
	allStats.numSkip += stats.numSkip
	allStats.numFail += stats.numFail
	}

	fmt.Printf("%d tests run", allStats.numTests)
	if allStats.numPass > 0 {
	fmt.Printf(", ")
	color.Set(color.FgGreen)
	fmt.Printf("%d tests pass", allStats.numPass)
	color.Unset()
	} else {
	fmt.Printf(", %d tests pass", allStats.numPass)
	}
	if allStats.numSkip > 0 {
	fmt.Printf(", ")
	color.Set(color.FgYellow)
	fmt.Printf("%d tests skipped", allStats.numSkip)
	color.Unset()
	} else {
	fmt.Printf(", %d tests skipped", allStats.numSkip)
	}
	if allStats.numFail > 0 {
	fmt.Printf(", ")
	color.Set(color.FgRed)
	fmt.Printf("%d tests failed", allStats.numFail)
	color.Unset()
	} else {
	fmt.Printf(", %d tests failed", allStats.numFail)
	}
	fmt.Println()
	fmt.Println()

	if allStats.numFail > 0 {
	os.Exit(1)
	}

	return nil
	}

	// Structures to hold the results of the tests
	type statusCode string

	const (
	fail statusCode = "FAIL"
	pass statusCode = "PASS"
	skip statusCode = "SKIP"
	)

	type status struct {
	code statusCode
	err error
	timeTaken time.Duration
	}

	type job struct {
	file string
	flags []string
	format outputFormat
	result chan status
	}

	func (j job) run(wd, exe string, fxc bool, dxcPath, xcrunPath string, generateExpected, generateSkip bool) {
	j.result <- func() status {
	// Is there an expected output?
	expected := loadExpectedFile(j.file, j.format)
	skipped := false
	if strings.HasPrefix(expected, "SKIP") { // Special SKIP token
	skipped = true
	}

	expected = strings.ReplaceAll(expected, "\r\n", "\n")

	file, err := filepath.Rel(wd, j.file)
	if err != nil {
	file = j.file
	}

	// Make relative paths use forward slash separators (on Windows) so that paths in tint
	// output match expected output that contain errors
	file = strings.ReplaceAll(file, `\`, `/`)

	args := []string{
	file,
	"--format", string(j.format),
	}

	// Can we validate?
	validate := false
	switch j.format {
	case wgsl:
	validate = true
	case spvasm, glsl:
	args = append(args, "--validate") // spirv-val and glslang are statically linked, always available
	validate = true
	case hlsl:
	if fxc {
	args = append(args, "--fxc")
	validate = true
	} else if dxcPath != "" {
	args = append(args, "--dxc", dxcPath)
	validate = true
	}
	case msl:
	if xcrunPath != "" {
	args = append(args, "--xcrun", xcrunPath)
	validate = true
	}
	}

	args = append(args, j.flags...)

	// Invoke the compiler...
	start := time.Now()
	ok, out := invoke(wd, exe, args...)
	timeTaken := time.Since(start)

	out = strings.ReplaceAll(out, "\r\n", "\n")
	matched := expected == "" \|\| expected == out

	if ok && generateExpected && (validate \|\| !skipped) {
	saveExpectedFile(j.file, j.format, out)
	matched = true
	}

	switch {
	case ok && matched:
	// Test passed
	return status{code: pass, timeTaken: timeTaken}

	// --- Below this point the test has failed ---

	case skipped:
	if generateSkip {
	saveExpectedFile(j.file, j.format, "SKIP: FAILED\n\n"+out)
	}
	return status{code: skip, timeTaken: timeTaken}

	case !ok:
	// Compiler returned non-zero exit code
	if generateSkip {
	saveExpectedFile(j.file, j.format, "SKIP: FAILED\n\n"+out)
	}
	err := fmt.Errorf("%s", out)
	return status{code: fail, err: err, timeTaken: timeTaken}

	default:
	// Compiler returned zero exit code, or output was not as expected
	if generateSkip {
	saveExpectedFile(j.file, j.format, "SKIP: FAILED\n\n"+out)
	}

	// Expected output did not match
	dmp := diffmatchpatch.New()
	diff := dmp.DiffPrettyText(dmp.DiffMain(expected, out, true))
	err := fmt.Errorf(`Output was not as expected

	--------------------------------------------------------------------------------
	-- Expected: --
	--------------------------------------------------------------------------------
	%s

	--------------------------------------------------------------------------------
	-- Got: --
	--------------------------------------------------------------------------------
	%s

	--------------------------------------------------------------------------------
	-- Diff: --
	--------------------------------------------------------------------------------
	%s`,
	expected, out, diff)
	return status{code: fail, err: err, timeTaken: timeTaken}
	}
	}()
	}

	// loadExpectedFile loads the expected output file for the test file at 'path'
	// and the output format 'format'. If the file does not exist, or cannot be
	// read, then an empty string is returned.
	func loadExpectedFile(path string, format outputFormat) string {
	content, err := ioutil.ReadFile(expectedFilePath(path, format))
	if err != nil {
	return ""
	}
	return string(content)
	}

	// saveExpectedFile writes the expected output file for the test file at 'path'
	// and the output format 'format', with the content 'content'.
	func saveExpectedFile(path string, format outputFormat, content string) error {
	// Don't generate expected results for certain directories that contain
	// large corpora of tests for which the generated code is uninteresting.
	for _, exclude := range []string{"/test/unittest/", "/test/vk-gl-cts/"} {
	if strings.Contains(path, filepath.FromSlash(exclude)) {
	return nil
	}
	}
	return ioutil.WriteFile(expectedFilePath(path, format), []byte(content), 0666)
	}

	// expectedFilePath returns the expected output file path for the test file at
	// 'path' and the output format 'format'.
	func expectedFilePath(path string, format outputFormat) string {
	return path + ".expected." + string(format)
	}

	// indent returns the string 's' indented with 'n' whitespace characters
	func indent(s string, n int) string {
	tab := strings.Repeat(" ", n)
	return tab + strings.ReplaceAll(s, "\n", "\n"+tab)
	}

	// alignLeft returns the string of 'val' padded so that it is aligned left in
	// a column of the given width
	func alignLeft(val interface{}, width int) string {
	s := fmt.Sprint(val)
	padding := width - utf8.RuneCountInString(s)
	if padding < 0 {
	return s
	}
	return s + strings.Repeat(" ", padding)
	}

	// alignCenter returns the string of 'val' padded so that it is centered in a
	// column of the given width.
	func alignCenter(val interface{}, width int) string {
	s := fmt.Sprint(val)
	padding := width - utf8.RuneCountInString(s)
	if padding < 0 {
	return s
	}
	return strings.Repeat(" ", padding/2) + s + strings.Repeat(" ", (padding+1)/2)
	}

	// alignRight returns the string of 'val' padded so that it is aligned right in
	// a column of the given width
	func alignRight(val interface{}, width int) string {
	s := fmt.Sprint(val)
	padding := width - utf8.RuneCountInString(s)
	if padding < 0 {
	return s
	}
	return strings.Repeat(" ", padding) + s
	}

	// maxStringLen returns the maximum number of runes found in all the strings in
	// 'l'
	func maxStringLen(l []string) int {
	max := 0
	for _, s := range l {
	if c := utf8.RuneCountInString(s); c > max {
	max = c
	}
	}
	return max
	}

	// formatWidth returns the width in runes for the outputFormat column 'b'
	func formatWidth(b outputFormat) int {
	const min = 6
	c := utf8.RuneCountInString(string(b))
	if c < min {
	return min
	}
	return c
	}

	// percentage returns the percentage of n out of total as a string
	func percentage(n, total int) string {
	if total == 0 {
	return "-"
	}
	f := float64(n) / float64(total)
	return fmt.Sprintf("%.1f%c", f*100.0, '%')
	}

	// invoke runs the executable 'exe' with the provided arguments.
	func invoke(wd, exe string, args ...string) (ok bool, output string) {
	ctx, cancel := context.WithTimeout(context.Background(), testTimeout)
	defer cancel()

	cmd := exec.CommandContext(ctx, exe, args...)
	cmd.Dir = wd
	out, err := cmd.CombinedOutput()
	str := string(out)
	if err != nil {
	if ctx.Err() == context.DeadlineExceeded {
	return false, fmt.Sprintf("test timed out after %v", testTimeout)
	}
	if str != "" {
	return false, str
	}
	return false, err.Error()
	}
	return true, str
	}

	var reFlags = regexp.MustCompile(` \/\/ flags:(.*)\n`)

	// parseFlags looks for a `// flags:` header at the start of the file with the
	// given path, returning each of the space delimited tokens that follow for the
	// line
	func parseFlags(path string) []string {
	content, err := ioutil.ReadFile(path)
	if err != nil {
	return nil
	}
	header := strings.SplitN(string(content), "\n", 1)[0]
	m := reFlags.FindStringSubmatch(header)
	if len(m) != 2 {
	return nil
	}
	return strings.Split(m[1], " ")
	}

	func printDuration(d time.Duration) string {
	sec := int(d.Seconds())
	min := int(sec) / 60
	hour := min / 60
	min -= hour * 60
	sec -= min * 60
	sb := &strings.Builder{}
	if hour > 0 {
	fmt.Fprintf(sb, "%dh", hour)
	}
	if min > 0 {
	fmt.Fprintf(sb, "%dm", min)
	}
	if sec > 0 {
	fmt.Fprintf(sb, "%ds", sec)
	}
	return sb.String()
	}