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authorKarl Williamson <public@khwilliamson.com>2011-01-05 10:11:49 -0700
committerKarl Williamson <public@khwilliamson.com>2011-01-05 11:07:07 -0700
commit7131f24d68f0c825d2313b84c611a3290bbe6b23 (patch)
tree0550c63c8a7a8543dd0f6200409e4ba7773ff21e /utf8.h
parent50db69d859446083d83085cfe0a7553942a82adf (diff)
downloadperl-7131f24d68f0c825d2313b84c611a3290bbe6b23.tar.gz
utf8.h: Add macros for problematic code points
Surrogates, non-character code points, and non-Unicode code points are problematic in some contexts. These macros allow easy determination if a code point is in one of these classes. There are versions both for UVs, and utf8-encoded.
Diffstat (limited to 'utf8.h')
-rw-r--r--utf8.h100
1 files changed, 100 insertions, 0 deletions
diff --git a/utf8.h b/utf8.h
index db088ea04a..636ac8a155 100644
--- a/utf8.h
+++ b/utf8.h
@@ -246,6 +246,97 @@ Perl's extended UTF-8 means we can have start bytes up to FF.
#define UTF8_ALLOW_DEFAULT (ckWARN(WARN_UTF8) ? 0 : \
UTF8_ALLOW_ANYUV)
+/* Surrogates, non-character code points and above-Unicode code points are
+ * problematic in some contexts. This allows code that needs to check for
+ * those to to quickly exclude the vast majority of code points it will
+ * encounter */
+#ifdef EBCDIC
+# define UTF8_FIRST_PROBLEMATIC_CODE_POINT_FIRST_BYTE UTF_TO_NATIVE(0xF1)
+#else
+# define UTF8_FIRST_PROBLEMATIC_CODE_POINT_FIRST_BYTE 0xED
+#endif
+
+/* ASCII EBCDIC I8
+ * U+D7FF: \xED\x9F\xBF \xF1\xB5\xBF\xBF last before surrogates
+ * U+D800: \xED\xA0\x80 \xF1\xB6\xA0\xA0 1st surrogate
+ * U+DFFF: \xED\xBF\xBF \xF1\xB7\xBF\xBF final surrogate
+ * U+E000: \xEE\x80\x80 \xF1\xB8\xA0\xA0 next after surrogates
+ */
+#ifdef EBCDIC /* Both versions assume well-formed UTF8 */
+# define UTF8_IS_SURROGATE(s) (*(s) == UTF_TO_NATIVE(0xF1) \
+ && (*((s) +1) == UTF_TO_NATIVE(0xB6)) || *((s) + 1) == UTF_TO_NATIVE(0xB7))
+#else
+# define UTF8_IS_SURROGATE(s) (*(s) == 0xED && *((s) + 1) >= 0xA0)
+#endif
+
+/* ASCII EBCDIC I8
+ * U+10FFFF: \xF4\x8F\xBF\xBF \xF9\xA1\xBF\xBF\xBF max legal Unicode
+ * U+110000: \xF4\x90\x80\x80 \xF9\xA2\xA0\xA0\xA0
+ * U+110001: \xF4\x90\x80\x81 \xF9\xA2\xA0\xA0\xA1
+ */
+#ifdef EBCDIC /* Both versions assume well-formed UTF8 */
+# define UTF8_IS_SUPER(s) (*(s) >= UTF_TO_NATIVE(0xF9) \
+ && (*(s) > UTF_TO_NATIVE(0xF9) || (*((s) + 1) >= UTF_TO_NATIVE(0xA2))))
+#else
+# define UTF8_IS_SUPER(s) (*(s) >= 0xF4 \
+ && (*(s) > 0xF4 || (*((s) + 1) >= 0x90)))
+#endif
+
+/* ASCII EBCDIC I8
+ * U+FDCF: \xEF\xB7\x8F \xF1\xBF\xAE\xAF last before non-char block
+ * U+FDD0: \xEF\xB7\x90 \xF1\xBF\xAE\xB0 first non-char in block
+ * U+FDEF: \xEF\xB7\xAF \xF1\xBF\xAF\xAF last non-char in block
+ * U+FDF0: \xEF\xB7\xB0 \xF1\xBF\xAF\xB0 first after non-char block
+ * U+FFFF: \xEF\xBF\xBF \xF1\xBF\xBF\xBF
+ * U+1FFFF: \xF0\x9F\xBF\xBF \xF3\xBF\xBF\xBF
+ * U+2FFFF: \xF0\xAF\xBF\xBF \xF5\xBF\xBF\xBF
+ * U+3FFFF: \xF0\xBF\xBF\xBF \xF7\xBF\xBF\xBF
+ * U+4FFFF: \xF1\x8F\xBF\xBF \xF8\xA9\xBF\xBF\xBF
+ * U+5FFFF: \xF1\x9F\xBF\xBF \xF8\xAB\xBF\xBF\xBF
+ * U+6FFFF: \xF1\xAF\xBF\xBF \xF8\xAD\xBF\xBF\xBF
+ * U+7FFFF: \xF1\xBF\xBF\xBF \xF8\xAF\xBF\xBF\xBF
+ * U+8FFFF: \xF2\x8F\xBF\xBF \xF8\xB1\xBF\xBF\xBF
+ * U+9FFFF: \xF2\x9F\xBF\xBF \xF8\xB3\xBF\xBF\xBF
+ * U+AFFFF: \xF2\xAF\xBF\xBF \xF8\xB5\xBF\xBF\xBF
+ * U+BFFFF: \xF2\xBF\xBF\xBF \xF8\xB7\xBF\xBF\xBF
+ * U+CFFFF: \xF3\x8F\xBF\xBF \xF8\xB9\xBF\xBF\xBF
+ * U+DFFFF: \xF3\x9F\xBF\xBF \xF8\xBB\xBF\xBF\xBF
+ * U+EFFFF: \xF3\xAF\xBF\xBF \xF8\xBD\xBF\xBF\xBF
+ * U+FFFFF: \xF3\xBF\xBF\xBF \xF8\xBF\xBF\xBF\xBF
+ * U+10FFFF: \xF4\x8F\xBF\xBF \xF9\xA1\xBF\xBF\xBF
+ */
+#define UTF8_IS_NONCHAR_(s) ( \
+ *(s) >= UTF8_FIRST_PROBLEMATIC_CODE_POINT_FIRST_BYTE \
+ && ! UTF8_IS_SUPER(s) \
+ && UTF8_IS_NONCHAR_GIVEN_THAT_NON_SUPER_AND_GE_FIRST_PROBLEMATIC(s) \
+
+#ifdef EBCDIC /* Both versions assume well-formed UTF8 */
+# define UTF8_IS_NONCHAR_GIVEN_THAT_NON_SUPER_AND_GE_PROBLEMATIC(s) \
+ ((*(s) == UTF_TO_NATIVE(0xF1) \
+ && (*((s) + 1) == UTF_TO_NATIVE(0xBF) \
+ && ((*((s) + 2) == UTF_TO_NATIVE(0xAE) \
+ && *((s) + 3) >= UTF_TO_NATIVE(0xB0)) \
+ || (*((s) + 2) == UTF_TO_NATIVE(0xAF) \
+ && *((s) + 3) <= UTF_TO_NATIVE(0xAF))))) \
+ || (UTF8SKIP(*(s)) > 3 \
+ /* (These were all derived by inspection and experimentation with an */ \
+ /* editor) The next line checks the next to final byte in the char */ \
+ && *((s) + UTF8SKIP(*(s)) - 2) == UTF_TO_NATIVE(0xBF) \
+ && *((s) + UTF8SKIP(*(s)) - 3) == UTF_TO_NATIVE(0xBF) \
+ && (NATIVE_TO_UTF(*((s) + UTF8SKIP(*(s)) - 4)) & 0x81) == 0x81 \
+ && (NATIVE_TO_UTF(*((s) + UTF8SKIP(*(s)) - 1)) & 0xBE) == 0XBE))
+#else
+# define UTF8_IS_NONCHAR_GIVEN_THAT_NON_SUPER_AND_GE_PROBLEMATIC(s) \
+ ((*(s) == 0xEF \
+ && ((*((s) + 1) == 0xB7 && (*((s) + 2) >= 0x90 && (*((s) + 2) <= 0xAF)))\
+ /* Gets U+FFF[EF] */ \
+ || (*((s) + 1) == 0xBF && ((*((s) + 2) & 0xBE) == 0xBE)))) \
+ || ((*((s) + 2) == 0xBF \
+ && (*((s) + 3) & 0xBE) == 0xBE \
+ /* Excludes things like U+10FFE = \xF0\x90\xBF\xBE */ \
+ && (*((s) + 1) & 0x8F) == 0x8F)))
+#endif
+
#define UNICODE_SURROGATE_FIRST 0xD800
#define UNICODE_SURROGATE_LAST 0xDFFF
#define UNICODE_REPLACEMENT 0xFFFD
@@ -267,6 +358,15 @@ Perl's extended UTF-8 means we can have start bytes up to FF.
#define UNICODE_IS_REPLACEMENT(c) ((c) == UNICODE_REPLACEMENT)
#define UNICODE_IS_BYTE_ORDER_MARK(c) ((c) == UNICODE_BYTE_ORDER_MARK)
#define UNICODE_IS_ILLEGAL(c) ((c) == UNICODE_ILLEGAL)
+#define UNICODE_IS_NONCHAR(c) ((c >= 0xFDD0 && c <= 0xFDEF) \
+ /* The other noncharacters end in FFFE or FFFF, which \
+ * the mask below catches both of, but beyond the last \
+ * official unicode code point, they aren't \
+ * noncharacters, since those aren't Unicode \
+ * characters at all */ \
+ || ((((c & 0xFFFE) == 0xFFFE)) && ! UNICODE_IS_SUPER(c)))
+#define UNICODE_IS_SUPER(c) ((c) > PERL_UNICODE_MAX)
+#define UNICODE_IS_FE_FF(c) ((c) > 0x7FFFFFFF)
#ifdef HAS_QUAD
# define UTF8_QUAD_MAX UINT64_C(0x1000000000)