return nil, nil
	}

	// Find assembly files to work on.
	var sfiles []string
	for _, fname := range pass.OtherFiles {
		if strings.HasSuffix(fname, ".s") && pass.Pkg.Path() != "runtime" {
			sfiles = append(sfiles, fname)
		}
	}

	for _, fname := range sfiles {
		content, tf, err := analysisutil.ReadFile(pass, fname)
		if err != nil {
			return nil, err
		}

			}

			pkg, err := context.Import(pkgName, "", 0)
			if err != nil {
				t.Fatal(err)
			}
			if len(pkg.SFiles) == 0 {
				continue
			}
			t.Errorf("package %s has purego assembly files on %s: %v", pkgName, GOARCH, pkg.SFiles)
		}
	}

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

// generateUsageTestFiles create nFolders * nFiles files of size bytes each.
func generateUsageTestFiles(t *testing.T, base, bucket string, nFolders, nFiles, size int) {
	pl := make([]byte, size)
	for i := 0; i < nFolders; i++ {
		name := filepath.Join(base, bucket, fmt.Sprint(i), "0.txt")
		err := os.MkdirAll(filepath.Dir(name), os.ModePerm)
		if err != nil {

	for tag := range allTags {
		p.AllTags = append(p.AllTags, tag)
	}
	sort.Strings(p.AllTags)

	if len(p.CgoFiles) > 0 {
		p.SFiles = append(p.SFiles, Sfiles...)
		sort.Strings(p.SFiles)
	} else {
		p.IgnoredOtherFiles = append(p.IgnoredOtherFiles, Sfiles...)
		sort.Strings(p.IgnoredOtherFiles)
	}

	if badGoError != nil {
		return p, badGoError
	}

		return !strings.HasPrefix(p, ".") && (!strings.HasPrefix(p, "_") || !strings.HasSuffix(p, ".go"))
	})

	// Add generated files for this package.
	for _, gt := range gentab {
		if gt.pkg == pkg {
			files = append(files, gt.file)
		}
	}
	files = uniq(files)

	// Convert to absolute paths.
	for i, p := range files {
		if !filepath.IsAbs(p) {
			files[i] = pathf("%s/%s", dir, p)

		}

		// Determine which command to use to display open files.
		ofcmd := "lsof"
		switch runtime.GOOS {
		case "dragonfly", "freebsd", "netbsd", "openbsd":
			ofcmd = "fstat"
		case "plan9":
			ofcmd = "/bin/cat"
		case "aix":
			ofcmd = "procfiles"
		case "solaris", "illumos":
			ofcmd = "pfiles"
		}

		cmd := exec.Command(ofcmd, args...)
		out, err := cmd.CombinedOutput()

	abiSuff      = re(`^(.+)<(ABI.+)>$`)
)

func run(pass *analysis.Pass) (interface{}, error) {
	// No work if no assembly files.
	var sfiles []string
	for _, fname := range pass.OtherFiles {
		if strings.HasSuffix(fname, ".s") {
			sfiles = append(sfiles, fname)
		}
	}
	if sfiles == nil {
		return nil, nil
	}

	// Gather declarations. knownFunc[name][arch] is func description.

// of the index at which each CU begins in runtime.cutab.
//
// Function objects keep track of the files they reference to print the stack.
// This function creates a per-CU list of filenames if CU[M] references
// files[1-N], the following is generated:
//
//	runtime.cutab:
//	  CU[M]
//	   offsetToFilename[0]
//	   offsetToFilename[1]
//	   ..
//

	{"kern.mbstat", []_C_int{1, 59}},
	{"kern.msgbuf", []_C_int{1, 48}},
	{"kern.msgbufsize", []_C_int{1, 38}},
	{"kern.nchstats", []_C_int{1, 41}},
	{"kern.netlivelocks", []_C_int{1, 76}},
	{"kern.nfiles", []_C_int{1, 56}},
	{"kern.ngroups", []_C_int{1, 18}},
	{"kern.nosuidcoredump", []_C_int{1, 32}},
	{"kern.nprocs", []_C_int{1, 47}},
	{"kern.nthreads", []_C_int{1, 26}},
	{"kern.numvnodes", []_C_int{1, 58}},

	{"kern.mbstat", []_C_int{1, 59}},
	{"kern.msgbuf", []_C_int{1, 48}},
	{"kern.msgbufsize", []_C_int{1, 38}},
	{"kern.nchstats", []_C_int{1, 41}},
	{"kern.netlivelocks", []_C_int{1, 76}},
	{"kern.nfiles", []_C_int{1, 56}},
	{"kern.ngroups", []_C_int{1, 18}},
	{"kern.nosuidcoredump", []_C_int{1, 32}},
	{"kern.nprocs", []_C_int{1, 47}},
	{"kern.nthreads", []_C_int{1, 26}},
	{"kern.numvnodes", []_C_int{1, 58}},