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package parser
import (
"bytes"
"encoding/hex"
"fmt"
"strconv"
"strings"
"unicode/utf8"
"github.com/dexon-foundation/dexon/core/vm/sqlvm/ast"
"github.com/dexon-foundation/dexon/core/vm/sqlvm/errors"
"github.com/shopspring/decimal"
)
// Parser was generated with pigeon v1.0.0-99-gbb0192c.
//go:generate pigeon -no-recover -o grammar.go grammar.peg
//go:generate sh -c "sed -f grammar.sed grammar.go > grammar_new.go"
//go:generate mv grammar_new.go grammar.go
//go:generate goimports -w grammar.go
func prepend(x interface{}, xs interface{}) []interface{} {
return append([]interface{}{x}, toSlice(xs)...)
}
func toSlice(x interface{}) []interface{} {
if x == nil {
return nil
}
return x.([]interface{})
}
// TODO(wmin0): finish it.
func isAddress(h []byte) bool {
return false
}
func hexToInteger(h []byte) interface{} {
d := decimal.Zero
l := len(h)
base := decimal.New(16, 0)
for idx, b := range h {
i, err := strconv.ParseInt(string([]byte{b}), 16, 32)
if err != nil {
panic(fmt.Sprintf("invalid hex digit %s: %v", []byte{b}, err))
}
d = d.Add(
decimal.New(i, 0).
Mul(base.Pow(decimal.New(int64(l-idx-1), 0))),
)
}
return ast.IntegerValueNode{V: d, IsAddress: isAddress(h)}
}
func hexToBytes(h []byte) []byte {
bs := make([]byte, hex.DecodedLen(len(h)))
_, err := hex.Decode(bs, h)
if err != nil {
panic(fmt.Sprintf("invalid hex string %s: %v", h, err))
}
return bs
}
func convertNumError(err error) errors.ErrorCode {
if err == nil {
return errors.ErrorCodeNil
}
switch err.(*strconv.NumError).Err {
case strconv.ErrSyntax:
return errors.ErrorCodeInvalidIntegerSyntax
case strconv.ErrRange:
return errors.ErrorCodeIntegerOutOfRange
}
panic(fmt.Sprintf("unknown NumError: %v", err))
}
func convertDecimalError(err error) errors.ErrorCode {
if err == nil {
return errors.ErrorCodeNil
}
errStr := err.Error()
if strings.HasSuffix(errStr, "decimal: fractional part too long") {
return errors.ErrorCodeFractionalPartTooLong
} else if strings.HasSuffix(errStr, "decimal: exponent is not numeric") {
return errors.ErrorCodeInvalidNumberSyntax
} else if strings.HasSuffix(errStr, "decimal: too many .s") {
return errors.ErrorCodeInvalidNumberSyntax
}
panic(fmt.Sprintf("unknown decimal error: %v", err))
}
func toUint(b []byte) (uint32, errors.ErrorCode) {
i, err := strconv.ParseUint(string(b), 10, 32)
return uint32(i), convertNumError(err)
}
func toDecimal(b []byte) (decimal.Decimal, errors.ErrorCode) {
if len(b) > 0 && b[0] == byte('.') {
b = append([]byte{'0'}, b...)
}
d, err := decimal.NewFromString(string(b))
return d, convertDecimalError(err)
}
func toLower(b []byte) []byte {
return bytes.ToLower(b)
}
func joinBytes(x interface{}) []byte {
xs := toSlice(x)
bs := []byte{}
for _, b := range xs {
bs = append(bs, b.([]byte)...)
}
return bs
}
func opSetSubject(op interface{}, s interface{}) interface{} {
x := op.(ast.BinaryOperator)
x.SetSubject(s)
return x
}
func opSetObject(op interface{}, o interface{}) interface{} {
x := op.(ast.BinaryOperator)
x.SetObject(o)
return x
}
func opSetTarget(op interface{}, t interface{}) interface{} {
x := op.(ast.UnaryOperator)
x.SetTarget(t)
return x
}
func joinOperator(x interface{}, o interface{}) {
if op, ok := x.(ast.UnaryOperator); ok {
joinOperator(op.GetTarget(), o)
return
}
if op, ok := x.(ast.BinaryOperator); ok {
op.SetObject(o)
return
}
}
func rightJoinOperators(o interface{}, x interface{}) interface{} {
xs := toSlice(x)
if len(xs) == 0 {
return o
}
l := len(xs)
for idx := 0; idx < l-1; idx++ {
joinOperator(xs[idx+1], xs[idx])
}
joinOperator(xs[0], o)
return xs[l-1]
}
func sanitizeBadEscape(s []byte) []byte {
o := bytes.Buffer{}
for _, b := range s {
if b >= 0x20 && b <= 0x7e && b != '\'' {
o.WriteByte(b)
} else {
o.WriteString(fmt.Sprintf("<%02X>", b))
}
}
return o.Bytes()
}
func decodeString(s []byte) []byte {
o := bytes.Buffer{}
for r, i, size := rune(0), 0, 0; i < len(s); i += size {
r, size = utf8.DecodeRune(s[i:])
if r > 0xff {
panic(fmt.Sprintf("invalid encoded rune U+%04X", r))
}
o.WriteByte(byte(r))
}
return o.Bytes()
}
func resolveString(s []byte) ([]byte, []byte, errors.ErrorCode) {
s = decodeString(s)
o := bytes.Buffer{}
for i, size := 0, 0; i < len(s); i += size {
if s[i] == '\\' {
if i+1 >= len(s) {
panic("trailing backslash in string literal")
}
switch s[i+1] {
case '\n':
size = 2
case '\\':
o.WriteByte('\\')
size = 2
case '\'':
o.WriteByte('\'')
size = 2
case '"':
o.WriteByte('"')
size = 2
case 'b':
o.WriteByte('\b')
size = 2
case 'f':
o.WriteByte('\f')
size = 2
case 'n':
o.WriteByte('\n')
size = 2
case 'r':
o.WriteByte('\r')
size = 2
case 't':
o.WriteByte('\t')
size = 2
case 'v':
o.WriteByte('\v')
size = 2
case 'x':
if i+3 >= len(s) {
return nil, s[i:], errors.ErrorCodeEscapeSequenceTooShort
}
b, err := strconv.ParseUint(string(s[i+2:i+4]), 16, 8)
if err != nil {
return nil, s[i : i+4], convertNumError(err)
}
o.WriteByte(uint8(b))
size = 4
case 'u':
if i+5 >= len(s) {
return nil, s[i:], errors.ErrorCodeEscapeSequenceTooShort
}
u, err := strconv.ParseUint(string(s[i+2:i+6]), 16, 16)
if err != nil {
return nil, s[i : i+6], convertNumError(err)
}
if u >= 0xd800 && u <= 0xdfff {
return nil, s[i : i+6], errors.ErrorCodeInvalidUnicodeCodePoint
}
o.WriteRune(rune(u))
size = 6
case 'U':
if i+9 >= len(s) {
return nil, s[i:], errors.ErrorCodeEscapeSequenceTooShort
}
r, err := strconv.ParseUint(string(s[i+2:i+10]), 16, 32)
if err != nil {
return nil, s[i : i+10], convertNumError(err)
}
if r >= 0x10ffff || (r >= 0xd800 && r <= 0xdfff) {
return nil, s[i : i+10], errors.ErrorCodeInvalidUnicodeCodePoint
}
o.WriteRune(rune(r))
size = 10
default:
return nil, s[i : i+2], errors.ErrorCodeUnknownEscapeSequence
}
} else {
o.WriteByte(s[i])
size = 1
}
}
return o.Bytes(), nil, errors.ErrorCodeNil
}
// Parse parses SQL commands text and return an AST.
func Parse(b []byte, o ...Option) (interface{}, error) {
// The string sent from the caller is not guaranteed to be valid UTF-8.
// We don't really care non-ASCII characters in the string because all
// keywords and special symbols are defined in ASCII. Therefore, as long
// as the encoding is compatible with ASCII, we can process text with
// unknown encoding.
//
// However, pigeon requires input text to be valid UTF-8, throwing an error
// and exiting early when it cannot decode the input as UTF-8. In order to
// workaround it, we preprocess the input text by assuming each byte value
// is a Unicode code point and encoding the input text as UTF-8.
//
// This means that the byte offset reported by pigeon is wrong. We have to
// scan the the error list and the AST to fix positions in these structs
// before returning them to the caller.
// Encode the input text.
encBuf := bytes.Buffer{}
encMap := map[uint32]uint32{}
for i, c := range b {
encMap[uint32(encBuf.Len())] = uint32(i)
encBuf.WriteRune(rune(c))
}
encMap[uint32(encBuf.Len())] = uint32(len(b))
// Prepare arguments and call the parser.
eb := encBuf.Bytes()
options := append([]Option{Recover(false)}, o...)
root, pigeonErr := parse("", eb, options...)
// Process the AST.
if pigeonErr == nil {
return root, pigeonErr
}
// Process errors.
pigeonErrList := pigeonErr.(errList)
sqlvmErrList := make(errors.ErrorList, len(pigeonErrList))
for i := range pigeonErrList {
parserErr := pigeonErrList[i].(*parserError)
if sqlvmErr, ok := parserErr.Inner.(errors.Error); ok {
sqlvmErrList[i] = sqlvmErr
} else {
sqlvmErrList[i] = errors.Error{
Position: uint32(parserErr.pos.offset),
Category: errors.ErrorCategoryGrammar,
Code: errors.ErrorCodeParser,
Token: "",
Prefix: parserErr.prefix,
Message: parserErr.Inner.Error(),
}
}
sqlvmErrList[i].Token =
string(decodeString([]byte(sqlvmErrList[i].Token)))
if offset, ok := encMap[sqlvmErrList[i].Position]; ok {
sqlvmErrList[i].Position = offset
} else {
panic(fmt.Sprintf(
"cannot fix byte offset %d", sqlvmErrList[i].Position))
}
}
return root, sqlvmErrList
}
|