f.walk(&n.Type, ctxType, visit)
		}
	case *ast.FieldList:
		for _, field := range n.List {
			f.walk(field, context, visit)
		}
	case *ast.BadExpr:
	case *ast.Ident:
	case *ast.Ellipsis:
		f.walk(&n.Elt, ctxType, visit)
	case *ast.BasicLit:
	case *ast.FuncLit:
		f.walk(n.Type, ctxType, visit)
		f.walk(n.Body, ctxStmt, visit)
	case *ast.CompositeLit:
		f.walk(&n.Type, ctxType, visit)

	switch name {
	case "CR":
		if 0 <= n && n <= 7 {
			return ppc64.REG_CR0 + n, true
		}
	case "A":
		if 0 <= n && n <= 8 {
			return ppc64.REG_A0 + n, true
		}
	case "VS":
		if 0 <= n && n <= 63 {
			return ppc64.REG_VS0 + n, true
		}
	case "V":
		if 0 <= n && n <= 31 {
			return ppc64.REG_V0 + n, true
		}
	case "F":
		if 0 <= n && n <= 31 {

}

func s390xRegisterNumber(name string, n int16) (int16, bool) {
	switch name {
	case "AR":
		if 0 <= n && n <= 15 {
			return s390x.REG_AR0 + n, true
		}
	case "F":
		if 0 <= n && n <= 15 {
			return s390x.REG_F0 + n, true
		}
	case "R":
		if 0 <= n && n <= 15 {
			return s390x.REG_R0 + n, true
		}
	case "V":
		if 0 <= n && n <= 31 {
			return s390x.REG_V0 + n, true
		}
	}
	return 0, false

	// probably because it is not in POSIX.1, so we define it here.
	// It is not defined on Solaris.
	var nproc int
	setNproc := true
	switch runtime.GOOS {
	default:
		setNproc = false
	case "aix":
		nproc = 9
	case "linux":
		nproc = 6
	case "darwin", "dragonfly", "freebsd", "netbsd", "openbsd":
		nproc = 7
	}
	if setNproc {
		var rlim syscall.Rlimit
		if syscall.Getrlimit(nproc, &rlim) == nil {

import (
	"fmt"
	"os"
)

func main() {
	if len(os.Args) != 2 {
		fatal("usage: callback testname")
	}
	switch os.Args[1] {
	default:
		fatal("unknown test %q", os.Args[1])
	case "Call":
		testCall()
	case "Callback":
		testCallback()
	}
	println("OK")
}

func fatal(f string, args ...any) {
	fmt.Fprintln(os.Stderr, fmt.Sprintf(f, args...))
	os.Exit(1)
}

type GoCallback struct{}

	if n < utf8.UTFMax || n > 1e9 {
		panic("bad max token size")
	}
	if n < len(s.buf) {
		s.buf = make([]byte, n)
	}
	s.maxTokenSize = n
}

// ErrOrEOF is like Err, but returns EOF. Used to test a corner case.
func (s *Scanner) ErrOrEOF() error {
	return s.err

	switch n := x.(type) {
	default:
		error_(token.NoPos, "unexpected type %T in walk", x)
		panic("unexpected type")

	case *ast.IndexListExpr:
		f.walk(&n.X, ctxExpr, visit)
		f.walk(n.Indices, ctxExpr, visit)
	}
}

func funcTypeTypeParams(n *ast.FuncType) *ast.FieldList {
	return n.TypeParams
}

	go tool fix -r cftype <pkg>
	go tool fix -r jni <pkg>

It will replace nil with 0 in the appropriate places.

The EGLDisplay case was introduced in Go 1.12. Use the egl rewrite
to auto-update code from Go 1.11 and earlier:

	go tool fix -r egl <pkg>

The EGLConfig case was introduced in Go 1.15. Use the eglconf rewrite
to auto-update code from Go 1.14 and earlier:

	go tool fix -r eglconf <pkg>

	r := NewReader(z)

	c := make(chan error)
	go func() {
		_, err := r.ReadByte()
		c <- err
	}()

	select {
	case err := <-c:
		if err == nil {
			t.Error("error expected")
		} else if err != io.ErrNoProgress {
			t.Error("unexpected error:", err)
		}
	case <-time.After(time.Second):
		t.Error("test timed out (endless loop in ReadByte?)")
	}
}

	}()
	buf2.ReadFrom(panicReader{panic: true})
}

func TestReadFromNegativeReader(t *testing.T) {
	var b Buffer
	defer func() {
		switch err := recover().(type) {
		case nil:
			t.Fatal("bytes.Buffer.ReadFrom didn't panic")
		case error:
			// this is the error string of errNegativeRead
			wantError := "bytes.Buffer: reader returned negative count from Read"
			if err.Error() != wantError {