diff options
Diffstat (limited to 'src/pkg/go/scanner/scanner.go')
| -rw-r--r-- | src/pkg/go/scanner/scanner.go | 49 |
1 files changed, 29 insertions, 20 deletions
diff --git a/src/pkg/go/scanner/scanner.go b/src/pkg/go/scanner/scanner.go index 576b95a28..e5ac9d772 100644 --- a/src/pkg/go/scanner/scanner.go +++ b/src/pkg/go/scanner/scanner.go @@ -345,34 +345,43 @@ exit: } -func (S *Scanner) scanDigits(base, length int) { - for length > 0 && digitVal(S.ch) < base { - S.next() - length-- - } - if length > 0 { - S.error(S.pos, "illegal char escape") - } -} - - func (S *Scanner) scanEscape(quote int) { pos := S.pos - ch := S.ch - S.next() - switch ch { + + var i, base, max uint32 + switch S.ch { case 'a', 'b', 'f', 'n', 'r', 't', 'v', '\\', quote: - // nothing to do + S.next() + return case '0', '1', '2', '3', '4', '5', '6', '7': - S.scanDigits(8, 3-1) // 1 char read already + i, base, max = 3, 8, 255 case 'x': - S.scanDigits(16, 2) + S.next() + i, base, max = 2, 16, 255 case 'u': - S.scanDigits(16, 4) + S.next() + i, base, max = 4, 16, unicode.MaxRune case 'U': - S.scanDigits(16, 8) + S.next() + i, base, max = 8, 16, unicode.MaxRune default: - S.error(pos, "illegal char escape") + S.next() // always make progress + S.error(pos, "unknown escape sequence") + return + } + + var x uint32 + for ; i > 0; i-- { + d := uint32(digitVal(S.ch)) + if d > base { + S.error(S.pos, "illegal character in escape sequence") + return + } + x = x*base + d + S.next() + } + if x > max || 0xd800 <= x && x < 0xe000 { + S.error(pos, "escape sequence is invalid Unicode code point") } } |