src/internal/fuzz/encoding.go - go - Git at Google

 // Copyright 2021 The Go Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.

 package fuzz

 import (
 	"bytes"
 	"fmt"
 	"go/ast"
 	"go/parser"
 	"go/token"
 	"strconv"
 )

 // encVersion1 will be the first line of a file with version 1 encoding.
 var encVersion1 = "go test fuzz v1"

 // marshalCorpusFile encodes an arbitrary number of arguments into the file format for the
 // corpus.
 func marshalCorpusFile(vals ...any) []byte {
 	if len(vals) == 0 {
 		panic("must have at least one value to marshal")
 	}
 	b := bytes.NewBuffer([]byte(encVersion1 + "\n"))
 	// TODO(katiehockman): keep uint8 and int32 encoding where applicable,
 	// instead of changing to byte and rune respectively.
 	for _, val := range vals {
 		switch t := val.(type) {
 		case int, int8, int16, int64, uint, uint16, uint32, uint64, float32, float64, bool:
 			fmt.Fprintf(b, "%T(%v)\n", t, t)
 		case string:
 			fmt.Fprintf(b, "string(%q)\n", t)
 		case rune: // int32
 			fmt.Fprintf(b, "rune(%q)\n", t)
 		case byte: // uint8
 			fmt.Fprintf(b, "byte(%q)\n", t)
 		case []byte: // []uint8
 			fmt.Fprintf(b, "[]byte(%q)\n", t)
 		default:
 			panic(fmt.Sprintf("unsupported type: %T", t))
 		}
 	}
 	return b.Bytes()
 }

 // unmarshalCorpusFile decodes corpus bytes into their respective values.
 func unmarshalCorpusFile(b []byte) ([]any, error) {
 	if len(b) == 0 {
 		return nil, fmt.Errorf("cannot unmarshal empty string")
 	}
 	lines := bytes.Split(b, []byte("\n"))
 	if len(lines) < 2 {
 		return nil, fmt.Errorf("must include version and at least one value")
 	}
 	if string(lines[0]) != encVersion1 {
 		return nil, fmt.Errorf("unknown encoding version: %s", lines[0])
 	}
 	var vals []any
 	for _, line := range lines[1:] {
 		line = bytes.TrimSpace(line)
 		if len(line) == 0 {
 			continue
 		}
 		v, err := parseCorpusValue(line)
 		if err != nil {
 			return nil, fmt.Errorf("malformed line %q: %v", line, err)
 		}
 		vals = append(vals, v)
 	}
 	return vals, nil
 }

 func parseCorpusValue(line []byte) (any, error) {
 	fs := token.NewFileSet()
 	expr, err := parser.ParseExprFrom(fs, "(test)", line, 0)
 	if err != nil {
 		return nil, err
 	}
 	call, ok := expr.(*ast.CallExpr)
 	if !ok {
 		return nil, fmt.Errorf("expected call expression")
 	}
 	if len(call.Args) != 1 {
 		return nil, fmt.Errorf("expected call expression with 1 argument; got %d", len(call.Args))
 	}
 	arg := call.Args[0]

 	if arrayType, ok := call.Fun.(*ast.ArrayType); ok {
 		if arrayType.Len != nil {
 			return nil, fmt.Errorf("expected []byte or primitive type")
 		}
 		elt, ok := arrayType.Elt.(*ast.Ident)
 		if !ok || elt.Name != "byte" {
 			return nil, fmt.Errorf("expected []byte")
 		}
 		lit, ok := arg.(*ast.BasicLit)
 		if !ok || lit.Kind != token.STRING {
 			return nil, fmt.Errorf("string literal required for type []byte")
 		}
 		s, err := strconv.Unquote(lit.Value)
 		if err != nil {
 			return nil, err
 		}
 		return []byte(s), nil
 	}

 	idType, ok := call.Fun.(*ast.Ident)
 	if !ok {
 		return nil, fmt.Errorf("expected []byte or primitive type")
 	}
 	if idType.Name == "bool" {
 		id, ok := arg.(*ast.Ident)
 		if !ok {
 			return nil, fmt.Errorf("malformed bool")
 		}
 		if id.Name == "true" {
 			return true, nil
 		} else if id.Name == "false" {
 			return false, nil
 		} else {
 			return nil, fmt.Errorf("true or false required for type bool")
 		}
 	}
 	var (
 		val  string
 		kind token.Token
 	)
 	if op, ok := arg.(*ast.UnaryExpr); ok {
 		// Special case for negative numbers.
 		lit, ok := op.X.(*ast.BasicLit)
 		if !ok || (lit.Kind != token.INT && lit.Kind != token.FLOAT) {
 			return nil, fmt.Errorf("expected operation on int or float type")
 		}
 		if op.Op != token.SUB {
 			return nil, fmt.Errorf("unsupported operation on int: %v", op.Op)
 		}
 		val = op.Op.String() + lit.Value // e.g. "-" + "124"
 		kind = lit.Kind
 	} else {
 		lit, ok := arg.(*ast.BasicLit)
 		if !ok {
 			return nil, fmt.Errorf("literal value required for primitive type")
 		}
 		val, kind = lit.Value, lit.Kind
 	}

 	switch typ := idType.Name; typ {
 	case "string":
 		if kind != token.STRING {
 			return nil, fmt.Errorf("string literal value required for type string")
 		}
 		return strconv.Unquote(val)
 	case "byte", "rune":
 		if kind != token.CHAR {
 			return nil, fmt.Errorf("character literal required for byte/rune types")
 		}
 		n := len(val)
 		if n < 2 {
 			return nil, fmt.Errorf("malformed character literal, missing single quotes")
 		}
 		code, _, _, err := strconv.UnquoteChar(val[1:n-1], '\'')
 		if err != nil {
 			return nil, err
 		}
 		if typ == "rune" {
 			return code, nil
 		}
 		if code >= 256 {
 			return nil, fmt.Errorf("can only encode single byte to a byte type")
 		}
 		return byte(code), nil
 	case "int", "int8", "int16", "int32", "int64":
 		if kind != token.INT {
 			return nil, fmt.Errorf("integer literal required for int types")
 		}
 		return parseInt(val, typ)
 	case "uint", "uint8", "uint16", "uint32", "uint64":
 		if kind != token.INT {
 			return nil, fmt.Errorf("integer literal required for uint types")
 		}
 		return parseUint(val, typ)
 	case "float32":
 		if kind != token.FLOAT && kind != token.INT {
 			return nil, fmt.Errorf("float or integer literal required for float32 type")
 		}
 		v, err := strconv.ParseFloat(val, 32)
 		return float32(v), err
 	case "float64":
 		if kind != token.FLOAT && kind != token.INT {
 			return nil, fmt.Errorf("float or integer literal required for float64 type")
 		}
 		return strconv.ParseFloat(val, 64)
 	default:
 		return nil, fmt.Errorf("expected []byte or primitive type")
 	}
 }

 // parseInt returns an integer of value val and type typ.
 func parseInt(val, typ string) (any, error) {
 	switch typ {
 	case "int":
 		return strconv.Atoi(val)
 	case "int8":
 		i, err := strconv.ParseInt(val, 10, 8)
 		return int8(i), err
 	case "int16":
 		i, err := strconv.ParseInt(val, 10, 16)
 		return int16(i), err
 	case "int32":
 		i, err := strconv.ParseInt(val, 10, 32)
 		return int32(i), err
 	case "int64":
 		return strconv.ParseInt(val, 10, 64)
 	default:
 		panic("unreachable")
 	}
 }

 // parseInt returns an unsigned integer of value val and type typ.
 func parseUint(val, typ string) (any, error) {
 	switch typ {
 	case "uint":
 		i, err := strconv.ParseUint(val, 10, 0)
 		return uint(i), err
 	case "uint8":
 		i, err := strconv.ParseUint(val, 10, 8)
 		return uint8(i), err
 	case "uint16":
 		i, err := strconv.ParseUint(val, 10, 16)
 		return uint16(i), err
 	case "uint32":
 		i, err := strconv.ParseUint(val, 10, 32)
 		return uint32(i), err
 	case "uint64":
 		return strconv.ParseUint(val, 10, 64)
 	default:
 		panic("unreachable")
 	}
 }
	// Copyright 2021 The Go Authors. All rights reserved.
	// Use of this source code is governed by a BSD-style
	// license that can be found in the LICENSE file.

	package fuzz

	import (
	"bytes"
	"fmt"
	"go/ast"
	"go/parser"
	"go/token"
	"strconv"
	)

	// encVersion1 will be the first line of a file with version 1 encoding.
	var encVersion1 = "go test fuzz v1"

	// marshalCorpusFile encodes an arbitrary number of arguments into the file format for the
	// corpus.
	func marshalCorpusFile(vals ...any) []byte {
	if len(vals) == 0 {
	panic("must have at least one value to marshal")
	}
	b := bytes.NewBuffer([]byte(encVersion1 + "\n"))
	// TODO(katiehockman): keep uint8 and int32 encoding where applicable,
	// instead of changing to byte and rune respectively.
	for _, val := range vals {
	switch t := val.(type) {
	case int, int8, int16, int64, uint, uint16, uint32, uint64, float32, float64, bool:
	fmt.Fprintf(b, "%T(%v)\n", t, t)
	case string:
	fmt.Fprintf(b, "string(%q)\n", t)
	case rune: // int32
	fmt.Fprintf(b, "rune(%q)\n", t)
	case byte: // uint8
	fmt.Fprintf(b, "byte(%q)\n", t)
	case []byte: // []uint8
	fmt.Fprintf(b, "[]byte(%q)\n", t)
	default:
	panic(fmt.Sprintf("unsupported type: %T", t))
	}
	}
	return b.Bytes()
	}

	// unmarshalCorpusFile decodes corpus bytes into their respective values.
	func unmarshalCorpusFile(b []byte) ([]any, error) {
	if len(b) == 0 {
	return nil, fmt.Errorf("cannot unmarshal empty string")
	}
	lines := bytes.Split(b, []byte("\n"))
	if len(lines) < 2 {
	return nil, fmt.Errorf("must include version and at least one value")
	}
	if string(lines[0]) != encVersion1 {
	return nil, fmt.Errorf("unknown encoding version: %s", lines[0])
	}
	var vals []any
	for _, line := range lines[1:] {
	line = bytes.TrimSpace(line)
	if len(line) == 0 {
	continue
	}
	v, err := parseCorpusValue(line)
	if err != nil {
	return nil, fmt.Errorf("malformed line %q: %v", line, err)
	}
	vals = append(vals, v)
	}
	return vals, nil
	}

	func parseCorpusValue(line []byte) (any, error) {
	fs := token.NewFileSet()
	expr, err := parser.ParseExprFrom(fs, "(test)", line, 0)
	if err != nil {
	return nil, err
	}
	call, ok := expr.(*ast.CallExpr)
	if !ok {
	return nil, fmt.Errorf("expected call expression")
	}
	if len(call.Args) != 1 {
	return nil, fmt.Errorf("expected call expression with 1 argument; got %d", len(call.Args))
	}
	arg := call.Args[0]

	if arrayType, ok := call.Fun.(*ast.ArrayType); ok {
	if arrayType.Len != nil {
	return nil, fmt.Errorf("expected []byte or primitive type")
	}
	elt, ok := arrayType.Elt.(*ast.Ident)
	if !ok \|\| elt.Name != "byte" {
	return nil, fmt.Errorf("expected []byte")
	}
	lit, ok := arg.(*ast.BasicLit)
	if !ok \|\| lit.Kind != token.STRING {
	return nil, fmt.Errorf("string literal required for type []byte")
	}
	s, err := strconv.Unquote(lit.Value)
	if err != nil {
	return nil, err
	}
	return []byte(s), nil
	}

	idType, ok := call.Fun.(*ast.Ident)
	if !ok {
	return nil, fmt.Errorf("expected []byte or primitive type")
	}
	if idType.Name == "bool" {
	id, ok := arg.(*ast.Ident)
	if !ok {
	return nil, fmt.Errorf("malformed bool")
	}
	if id.Name == "true" {
	return true, nil
	} else if id.Name == "false" {
	return false, nil
	} else {
	return nil, fmt.Errorf("true or false required for type bool")
	}
	}
	var (
	val string
	kind token.Token
	)
	if op, ok := arg.(*ast.UnaryExpr); ok {
	// Special case for negative numbers.
	lit, ok := op.X.(*ast.BasicLit)
	if !ok \|\| (lit.Kind != token.INT && lit.Kind != token.FLOAT) {
	return nil, fmt.Errorf("expected operation on int or float type")
	}
	if op.Op != token.SUB {
	return nil, fmt.Errorf("unsupported operation on int: %v", op.Op)
	}
	val = op.Op.String() + lit.Value // e.g. "-" + "124"
	kind = lit.Kind
	} else {
	lit, ok := arg.(*ast.BasicLit)
	if !ok {
	return nil, fmt.Errorf("literal value required for primitive type")
	}
	val, kind = lit.Value, lit.Kind
	}

	switch typ := idType.Name; typ {
	case "string":
	if kind != token.STRING {
	return nil, fmt.Errorf("string literal value required for type string")
	}
	return strconv.Unquote(val)
	case "byte", "rune":
	if kind != token.CHAR {
	return nil, fmt.Errorf("character literal required for byte/rune types")
	}
	n := len(val)
	if n < 2 {
	return nil, fmt.Errorf("malformed character literal, missing single quotes")
	}
	code, _, _, err := strconv.UnquoteChar(val[1:n-1], '\'')
	if err != nil {
	return nil, err
	}
	if typ == "rune" {
	return code, nil
	}
	if code >= 256 {
	return nil, fmt.Errorf("can only encode single byte to a byte type")
	}
	return byte(code), nil
	case "int", "int8", "int16", "int32", "int64":
	if kind != token.INT {
	return nil, fmt.Errorf("integer literal required for int types")
	}
	return parseInt(val, typ)
	case "uint", "uint8", "uint16", "uint32", "uint64":
	if kind != token.INT {
	return nil, fmt.Errorf("integer literal required for uint types")
	}
	return parseUint(val, typ)
	case "float32":
	if kind != token.FLOAT && kind != token.INT {
	return nil, fmt.Errorf("float or integer literal required for float32 type")
	}
	v, err := strconv.ParseFloat(val, 32)
	return float32(v), err
	case "float64":
	if kind != token.FLOAT && kind != token.INT {
	return nil, fmt.Errorf("float or integer literal required for float64 type")
	}
	return strconv.ParseFloat(val, 64)
	default:
	return nil, fmt.Errorf("expected []byte or primitive type")
	}
	}

	// parseInt returns an integer of value val and type typ.
	func parseInt(val, typ string) (any, error) {
	switch typ {
	case "int":
	return strconv.Atoi(val)
	case "int8":
	i, err := strconv.ParseInt(val, 10, 8)
	return int8(i), err
	case "int16":
	i, err := strconv.ParseInt(val, 10, 16)
	return int16(i), err
	case "int32":
	i, err := strconv.ParseInt(val, 10, 32)
	return int32(i), err
	case "int64":
	return strconv.ParseInt(val, 10, 64)
	default:
	panic("unreachable")
	}
	}

	// parseInt returns an unsigned integer of value val and type typ.
	func parseUint(val, typ string) (any, error) {
	switch typ {
	case "uint":
	i, err := strconv.ParseUint(val, 10, 0)
	return uint(i), err
	case "uint8":
	i, err := strconv.ParseUint(val, 10, 8)
	return uint8(i), err
	case "uint16":
	i, err := strconv.ParseUint(val, 10, 16)
	return uint16(i), err
	case "uint32":
	i, err := strconv.ParseUint(val, 10, 32)
	return uint32(i), err
	case "uint64":
	return strconv.ParseUint(val, 10, 64)
	default:
	panic("unreachable")
	}
	}