c := r.peekByte(true)
	if c == '.' {
		r.peek = 0
	} else if isIdent(c) {
		r.readIdent()
	}
	r.readString(imports)
}

// ReadComments is like io.ReadAll, except that it only reads the leading
// block of comments in the file.
func ReadComments(f io.Reader) ([]byte, error) {
	r := newImportReader(bufio.NewReader(f))
	r.peekByte(true)
	if r.err == nil && !r.eof {

	c := r.peekByte(true)
	if c == '.' {
		r.peek = 0
	} else if isIdent(c) {
		r.readIdent()
	}
	r.readString(imports)
}

// readComments is like ioutil.ReadAll, except that it only reads the leading
// block of comments in the file.
func readComments(f io.Reader) ([]byte, error) {
	r := &importReader{b: bufio.NewReader(f)}
	r.peekByte(true)
	if r.err == nil && !r.eof {

	c := r.peekByte(true)
	if c == '.' {
		r.peek = 0
	} else if isIdent(c) {
		r.readIdent()
	}
	r.readString()
}

// readComments is like io.ReadAll, except that it only reads the leading
// block of comments in the file.
//
// readComments should be an internal detail,
// but widely used packages access it using linkname.
// Notable members of the hall of shame include:

func TestReadImports(t *testing.T) {
	testRead(t, readImportsTests, func(r io.Reader) ([]byte, error) { return ReadImports(r, true, nil) })
}

func TestReadComments(t *testing.T) {
	testRead(t, readCommentsTests, ReadComments)
}

var readFailuresTests = []readTest{
	{
		`package`,
		"syntax error",
	},
	{
		"package p\n\x00\nimport `math`\n",
		"unexpected NUL in input",
	},
	{
		`package p; import`,

	c := r.peekByte(true)
	if c == '.' {
		r.peek = 0
	} else if isIdent(c) {
		r.readIdent()
	}
	r.readString()
}

// readComments is like io.ReadAll, except that it only reads the leading
// block of comments in the file.
func readComments(f io.Reader) ([]byte, error) {
	r := newImportReader("", f)
	r.peekByte(true)
	if r.err == nil && !r.eof {

		var info fileInfo
		err := readGoInfo(r, &info)
		return info.header, err
	})
}

func TestReadComments(t *testing.T) {
	testRead(t, readCommentsTests, readComments)
}

var readFailuresTests = []readTest{
	{
		`package`,
		"syntax error",
	},
	{
		"package p\n\x00\nimport `math`\n",
		"unexpected NUL in input",
	},
	{
		`package p; import`,

		err = readGoInfo(f, info)
		if strings.HasSuffix(name, "_test.go") {
			ignoreBinaryOnly = true // ignore //go:binary-only-package comments in _test.go files
		}
	} else {
		info.header, err = readComments(f)
	}
	f.Close()
	if err != nil {
		return nil, fmt.Errorf("read %s: %v", info.name, err)
	}

	// Look for +build comments to accept or reject the file.

			binaryOnly = nil // ignore //go:binary-only-package comments in _test.go files
		}
	} else {
		binaryOnly = nil // ignore //go:binary-only-package comments in non-Go sources
		info.header, err = readComments(f)
	}
	f.Close()
	if err != nil {
		return info, fmt.Errorf("read %s: %v", info.name, err)
	}

	// Look for go:build comments to accept or reject the file.