drop bits of code to support Go 1.19

main.go

@@ -354,7 +354,7 @@ func mainErr(args []string) error {
 
 		// Until https://github.com/golang/go/issues/50603 is implemented,
 		// manually construct something like a pseudo-version.
-		// TODO: remove when this code is dead, hopefully in Go 1.20.
+		// TODO: remove when this code is dead, hopefully in Go 1.21.
 		if mod.Version == "(devel)" {
 			var vcsTime time.Time
 			var vcsRevision string
@@ -794,15 +794,8 @@ func replaceAsmNames(buf *bytes.Buffer, remaining []byte) {
 		// If the name was qualified, fetch the package, and write the
 		// obfuscated import path if needed.
 		// Note that we don't obfuscate the package path "main".
-		//
-		// Note that runtime/internal/startlinetest refers to runtime_test in
-		// one of its assembly files, and we currently do not always collect
-		// test packages in appendListedPackages for the sake of performance.
-		// We don't care about testing the runtime just yet, so work around it.
-		// TODO(mvdan): this runtime_test reference was removed in Go 1.20 per
-		// https://github.com/golang/go/issues/57334; remove at a later time.
 		lpkg := curPkg
-		if asmPkgPath != "" && asmPkgPath != "main" && asmPkgPath != "runtime_test" {
+		if asmPkgPath != "" && asmPkgPath != "main" {
 			if asmPkgPath != curPkg.Name {
 				goPkgPath := asmPkgPath
 				goPkgPath = strings.ReplaceAll(goPkgPath, string(asmPeriod), string(goPeriod))

main_test.go

@@ -315,8 +315,6 @@ func grepfiles(ts *testscript.TestScript, neg bool, args []string) {
 	anyFound := false
 	path, pattern := args[0], args[1]
 	rx := regexp.MustCompile(pattern)
-	// TODO: use fs.SkipAll in Go 1.20 and later.
-	errSkipAll := fmt.Errorf("sentinel error: stop walking")
 	if err := filepath.WalkDir(path, func(path string, d fs.DirEntry, err error) error {
 		if err != nil {
 			return err
@@ -326,11 +324,11 @@ func grepfiles(ts *testscript.TestScript, neg bool, args []string) {
 				return fmt.Errorf("%q matches %q", path, pattern)
 			} else {
 				anyFound = true
-				return errSkipAll
+				return fs.SkipAll
 			}
 		}
 		return nil
-	}); err != nil && err != errSkipAll {
+	}); err != nil {
 		ts.Fatalf("%s", err)
 	}
 	if !neg && !anyFound {

shared.go

@@ -278,22 +278,6 @@ func appendListedPackages(packages []string, withDeps bool) error {
 			pkg.GarbleActionID = addGarbleToHash(actionID)
 		}
 
-		// Work around https://go.dev/issue/28749:
-		// cmd/go puts assembly, C, and C++ files in CompiledGoFiles.
-		//
-		// TODO: Fixed in Go 1.20; remove once we drop support for Go 1.19.
-		out := pkg.CompiledGoFiles[:0]
-		for _, path := range pkg.CompiledGoFiles {
-			switch filepath.Ext(path) {
-			case "": // e.g. a generated Go file inside the build cache
-			case ".go":
-			default: // e.g. an assembly file
-				continue
-			}
-			out = append(out, path)
-		}
-		pkg.CompiledGoFiles = out
-
 		cache.ListedPackages[pkg.ImportPath] = &pkg
 	}
 

testdata/script/reverse.txtar

@@ -28,8 +28,7 @@ cp stderr build-error.stderr
 
 stdin build-error.stderr
 garble reverse ./build-error
-[!go1.20] cmp stdout build-error-reverse.stdout-go1.19
-[go1.20] cmp stdout build-error-reverse.stdout-go1.20
+cmp stdout build-error-reverse.stdout
 
 [short] stop # no need to verify this with -short
 
@@ -157,12 +156,7 @@ main.main(...)
 	test/main/long_main.go:11 +0x??
 
 main filename: test/main/long_main.go
--- build-error-reverse.stdout-go1.19 --
-# test/main/build-error
-test/main/build-error/error.go:18: cannot convert UnobfuscatedStruct{} (value of type UnobfuscatedStruct) to type struct{SomeField int}
-exit status 2
-exit status 2
--- build-error-reverse.stdout-go1.20 --
+-- build-error-reverse.stdout --
 # test/main/build-error
 test/main/build-error/error.go:18: cannot convert UnobfuscatedStruct{} (value of type UnobfuscatedStruct) to type struct{SomeField int}
 exit status 2