diff options
author | Corinna Vinschen <corinna@vinschen.de> | 2009-07-29 12:31:30 +0400 |
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committer | Corinna Vinschen <corinna@vinschen.de> | 2009-07-29 12:31:30 +0400 |
commit | a67f77af1aa3798cd75900b6445443d2915c8ef4 (patch) | |
tree | 1a01d5fdf750f47d158ea6ca6bd771c65bb5dcac | |
parent | 0c27cfc9b03ab2578b77e35abb8034831276d8de (diff) |
* libc/stdlib/mbtowc_r.c (__utf8_mbtowc): Rework UTF-16 surrogate
pair handling to be more bullet-proof even with incomplete UTF-8
sequences. Add check for 4 byte sequences resulting in values
outside the valid Unicode range. Add a comment to clarify checking
for invalid CESU-8 sequences.
-rw-r--r-- | newlib/ChangeLog | 8 | ||||
-rw-r--r-- | newlib/libc/stdlib/mbtowc_r.c | 62 |
2 files changed, 39 insertions, 31 deletions
diff --git a/newlib/ChangeLog b/newlib/ChangeLog index cf857246b..fe42b0725 100644 --- a/newlib/ChangeLog +++ b/newlib/ChangeLog @@ -1,3 +1,11 @@ +2009-07-29 Corinna Vinschen <corinna@vinschen.de> + + * libc/stdlib/mbtowc_r.c (__utf8_mbtowc): Rework UTF-16 surrogate + pair handling to be more bullet-proof even with incomplete UTF-8 + sequences. Add check for 4 byte sequences resulting in values + outside the valid Unicode range. Add a comment to clarify checking + for invalid CESU-8 sequences. + 2009-07-28 Corinna Vinschen <corinna@vinschen.de> * libc/stdlib/mbtowc_r.c (__utf8_mbtowc): Fix incrementing n in case diff --git a/newlib/libc/stdlib/mbtowc_r.c b/newlib/libc/stdlib/mbtowc_r.c index 7e1362245..4e80c51b1 100644 --- a/newlib/libc/stdlib/mbtowc_r.c +++ b/newlib/libc/stdlib/mbtowc_r.c @@ -205,18 +205,6 @@ _DEFUN (__utf8_mbtowc, (r, pwc, s, n, charset, state), if (n == 0) return -2; - if (state->__count == 4) - { - /* Create the second half of the surrogate pair. For a description - see the comment below. */ - wint_t tmp = (wchar_t)((state->__value.__wchb[0] & 0x07) << 18) - | (wchar_t)((state->__value.__wchb[1] & 0x3f) << 12) - | (wchar_t)((state->__value.__wchb[2] & 0x3f) << 6) - | (wchar_t)(state->__value.__wchb[3] & 0x3f); - state->__count = 0; - *pwc = 0xdc00 | ((tmp - 0x10000) & 0x3ff); - return 2; - } if (state->__count == 0) ch = t[i++]; else @@ -303,7 +291,7 @@ _DEFUN (__utf8_mbtowc, (r, pwc, s, n, charset, state), tmp = (wchar_t)((state->__value.__wchb[0] & 0x0f) << 12) | (wchar_t)((state->__value.__wchb[1] & 0x3f) << 6) | (wchar_t)(ch & 0x3f); - + /* Check for invalid CESU-8 encoding of UTF-16 surrogate values. */ if (tmp >= 0xd800 && tmp <= 0xdfff) { r->_errno = EILSEQ; @@ -312,7 +300,7 @@ _DEFUN (__utf8_mbtowc, (r, pwc, s, n, charset, state), *pwc = tmp; return i; } - if (ch >= 0xf0 && ch <= 0xf7) + if (ch >= 0xf0 && ch <= 0xf4) { /* four-byte sequence */ wint_t tmp; @@ -324,9 +312,10 @@ _DEFUN (__utf8_mbtowc, (r, pwc, s, n, charset, state), if (n < 2) return -2; ch = (state->__count == 1) ? t[i++] : state->__value.__wchb[1]; - if (state->__value.__wchb[0] == 0xf0 && ch < 0x90) + if ((state->__value.__wchb[0] == 0xf0 && ch < 0x90) + || (state->__value.__wchb[0] == 0xf4 && ch >= 0x90)) { - /* overlong UTF-8 sequence */ + /* overlong UTF-8 sequence or result is > 0x10ffff */ r->_errno = EILSEQ; return -1; } @@ -353,6 +342,26 @@ _DEFUN (__utf8_mbtowc, (r, pwc, s, n, charset, state), state->__count = 3; else if (n < (size_t)-1) ++n; + if (state->__count == 3 && sizeof(wchar_t) == 2) + { + /* On systems which have wchar_t being UTF-16 values, the value + doesn't fit into a single wchar_t in this case. So what we + do here is to store the state with a special value of __count + and return the first half of a surrogate pair. The first + three bytes of a UTF-8 sequence are enough to generate the + first half of a UTF-16 surrogate pair. As return value we + choose to return the number of bytes actually read up to + here. + The second half of the surrogate pair is returned in case we + recognize the special __count value of four, and the next + byte is actually a valid value. See below. */ + tmp = (wint_t)((state->__value.__wchb[0] & 0x07) << 18) + | (wint_t)((state->__value.__wchb[1] & 0x3f) << 12) + | (wint_t)((state->__value.__wchb[2] & 0x3f) << 6); + state->__count = 4; + *pwc = 0xd800 | ((tmp - 0x10000) >> 10); + return i; + } if (n < 4) return -2; ch = t[i++]; @@ -365,21 +374,12 @@ _DEFUN (__utf8_mbtowc, (r, pwc, s, n, charset, state), | (wint_t)((state->__value.__wchb[1] & 0x3f) << 12) | (wint_t)((state->__value.__wchb[2] & 0x3f) << 6) | (wint_t)(ch & 0x3f); - if (tmp > 0xffff && sizeof(wchar_t) == 2) - { - /* On systems which have wchar_t being UTF-16 values, the value - doesn't fit into a single wchar_t in this case. So what we - do here is to store the state with a special value of __count - and return the first half of a surrogate pair. As return - value we choose to return the half of the actual UTF-8 char. - The second half is returned in case we recognize the special - __count value above. */ - state->__value.__wchb[3] = ch; - state->__count = 4; - *pwc = 0xd800 | (((tmp - 0x10000) >> 10) & 0x3ff); - return 2; - } - *pwc = tmp; + if (state->__count == 4 && sizeof(wchar_t) == 2) + /* Create the second half of the surrogate pair for systems with + wchar_t == UTF-16 . */ + *pwc = 0xdc00 | (tmp & 0x3ff); + else + *pwc = tmp; state->__count = 0; return i; } |