* libc/string/wcwidth.c: Optimize for speed.

	* libc/locale/locale.c (lc_ctype_cjk_lang): New static int.
	(loadlocale): In case of setting LC_CTYPE, set lc_ctype_cjk_lang
	to 1 if the language is "jp", "ko", or "zh", to 0 otherwise.
	(__locale_cjk_lang): New function.
	* libc/string/local.h (__locale_cjk_lang): Declare.
	* libc/string/wcwidth.c: Fix comments.
	(__wcwidth): Handle CJK Ambiguous Width characters according
	to setting returned by __locale_cjk_lang.

1 files changed, 78 insertions, 4 deletions

diff --git a/newlib/libc/string/wcwidth.c b/newlib/libc/string/wcwidth.c
index 36d8d4f69..f825be6ab 100644
--- a/newlib/libc/string/wcwidth.c
+++ b/newlib/libc/string/wcwidth.c
@@ -127,7 +127,7 @@ bisearch(wint_t ucs, const struct interval *table, int max)
 }
 #endif /* _MB_CAPABLE */
 
-/* The following two functions define the column width of an ISO 10646
+/* The following function defines the column width of an ISO 10646
  * character as follows:
  *
  *    - The null character (U+0000) has a column width of 0.
@@ -135,6 +135,11 @@ bisearch(wint_t ucs, const struct interval *table, int max)
  *    - Other C0/C1 control characters and DEL will lead to a return
  *      value of -1.
  *
+ *    - If the current language is recognized as a language usually using
+ *      CJK fonts, spacing characters in the East Asian Ambiguous (A)
+ *      category as defined in Unicode Technical Report #11 have a column
+ *      width of 2.
+ *
  *    - Non-spacing and enclosing combining characters (general
  *      category code Mn or Me in the Unicode database) have a
  *      column width of 0.
@@ -155,7 +160,7 @@ bisearch(wint_t ucs, const struct interval *table, int max)
  *      ISO 8859-1 and WGL4 characters, Unicode control characters,
  *      etc.) have a column width of 1.
  *
- * This implementation assumes that wchar_t characters are encoded
+ * This implementation assumes that wint_t characters are encoded
  * in ISO 10646.
  */
 
@@ -164,6 +169,62 @@ _DEFUN (__wcwidth, (ucs),
 	_CONST wint_t ucs)
 {
 #ifdef _MB_CAPABLE
+  /* sorted list of non-overlapping intervals of East Asian Ambiguous
+   * characters, generated by "uniset +WIDTH-A -cat=Me -cat=Mn -cat=Cf c" */
+  static const struct interval ambiguous[] = {
+    { 0x00A1, 0x00A1 }, { 0x00A4, 0x00A4 }, { 0x00A7, 0x00A8 },
+    { 0x00AA, 0x00AA }, { 0x00AE, 0x00AE }, { 0x00B0, 0x00B4 },
+    { 0x00B6, 0x00BA }, { 0x00BC, 0x00BF }, { 0x00C6, 0x00C6 },
+    { 0x00D0, 0x00D0 }, { 0x00D7, 0x00D8 }, { 0x00DE, 0x00E1 },
+    { 0x00E6, 0x00E6 }, { 0x00E8, 0x00EA }, { 0x00EC, 0x00ED },
+    { 0x00F0, 0x00F0 }, { 0x00F2, 0x00F3 }, { 0x00F7, 0x00FA },
+    { 0x00FC, 0x00FC }, { 0x00FE, 0x00FE }, { 0x0101, 0x0101 },
+    { 0x0111, 0x0111 }, { 0x0113, 0x0113 }, { 0x011B, 0x011B },
+    { 0x0126, 0x0127 }, { 0x012B, 0x012B }, { 0x0131, 0x0133 },
+    { 0x0138, 0x0138 }, { 0x013F, 0x0142 }, { 0x0144, 0x0144 },
+    { 0x0148, 0x014B }, { 0x014D, 0x014D }, { 0x0152, 0x0153 },
+    { 0x0166, 0x0167 }, { 0x016B, 0x016B }, { 0x01CE, 0x01CE },
+    { 0x01D0, 0x01D0 }, { 0x01D2, 0x01D2 }, { 0x01D4, 0x01D4 },
+    { 0x01D6, 0x01D6 }, { 0x01D8, 0x01D8 }, { 0x01DA, 0x01DA },
+    { 0x01DC, 0x01DC }, { 0x0251, 0x0251 }, { 0x0261, 0x0261 },
+    { 0x02C4, 0x02C4 }, { 0x02C7, 0x02C7 }, { 0x02C9, 0x02CB },
+    { 0x02CD, 0x02CD }, { 0x02D0, 0x02D0 }, { 0x02D8, 0x02DB },
+    { 0x02DD, 0x02DD }, { 0x02DF, 0x02DF }, { 0x0391, 0x03A1 },
+    { 0x03A3, 0x03A9 }, { 0x03B1, 0x03C1 }, { 0x03C3, 0x03C9 },
+    { 0x0401, 0x0401 }, { 0x0410, 0x044F }, { 0x0451, 0x0451 },
+    { 0x2010, 0x2010 }, { 0x2013, 0x2016 }, { 0x2018, 0x2019 },
+    { 0x201C, 0x201D }, { 0x2020, 0x2022 }, { 0x2024, 0x2027 },
+    { 0x2030, 0x2030 }, { 0x2032, 0x2033 }, { 0x2035, 0x2035 },
+    { 0x203B, 0x203B }, { 0x203E, 0x203E }, { 0x2074, 0x2074 },
+    { 0x207F, 0x207F }, { 0x2081, 0x2084 }, { 0x20AC, 0x20AC },
+    { 0x2103, 0x2103 }, { 0x2105, 0x2105 }, { 0x2109, 0x2109 },
+    { 0x2113, 0x2113 }, { 0x2116, 0x2116 }, { 0x2121, 0x2122 },
+    { 0x2126, 0x2126 }, { 0x212B, 0x212B }, { 0x2153, 0x2154 },
+    { 0x215B, 0x215E }, { 0x2160, 0x216B }, { 0x2170, 0x2179 },
+    { 0x2190, 0x2199 }, { 0x21B8, 0x21B9 }, { 0x21D2, 0x21D2 },
+    { 0x21D4, 0x21D4 }, { 0x21E7, 0x21E7 }, { 0x2200, 0x2200 },
+    { 0x2202, 0x2203 }, { 0x2207, 0x2208 }, { 0x220B, 0x220B },
+    { 0x220F, 0x220F }, { 0x2211, 0x2211 }, { 0x2215, 0x2215 },
+    { 0x221A, 0x221A }, { 0x221D, 0x2220 }, { 0x2223, 0x2223 },
+    { 0x2225, 0x2225 }, { 0x2227, 0x222C }, { 0x222E, 0x222E },
+    { 0x2234, 0x2237 }, { 0x223C, 0x223D }, { 0x2248, 0x2248 },
+    { 0x224C, 0x224C }, { 0x2252, 0x2252 }, { 0x2260, 0x2261 },
+    { 0x2264, 0x2267 }, { 0x226A, 0x226B }, { 0x226E, 0x226F },
+    { 0x2282, 0x2283 }, { 0x2286, 0x2287 }, { 0x2295, 0x2295 },
+    { 0x2299, 0x2299 }, { 0x22A5, 0x22A5 }, { 0x22BF, 0x22BF },
+    { 0x2312, 0x2312 }, { 0x2460, 0x24E9 }, { 0x24EB, 0x254B },
+    { 0x2550, 0x2573 }, { 0x2580, 0x258F }, { 0x2592, 0x2595 },
+    { 0x25A0, 0x25A1 }, { 0x25A3, 0x25A9 }, { 0x25B2, 0x25B3 },
+    { 0x25B6, 0x25B7 }, { 0x25BC, 0x25BD }, { 0x25C0, 0x25C1 },
+    { 0x25C6, 0x25C8 }, { 0x25CB, 0x25CB }, { 0x25CE, 0x25D1 },
+    { 0x25E2, 0x25E5 }, { 0x25EF, 0x25EF }, { 0x2605, 0x2606 },
+    { 0x2609, 0x2609 }, { 0x260E, 0x260F }, { 0x2614, 0x2615 },
+    { 0x261C, 0x261C }, { 0x261E, 0x261E }, { 0x2640, 0x2640 },
+    { 0x2642, 0x2642 }, { 0x2660, 0x2661 }, { 0x2663, 0x2665 },
+    { 0x2667, 0x266A }, { 0x266C, 0x266D }, { 0x266F, 0x266F },
+    { 0x273D, 0x273D }, { 0x2776, 0x277F }, { 0xE000, 0xF8FF },
+    { 0xFFFD, 0xFFFD }, { 0xF0000, 0xFFFFD }, { 0x100000, 0x10FFFD }
+  };
   /* sorted list of non-overlapping intervals of non-spacing characters */
   /* generated by "uniset +cat=Me +cat=Mn +cat=Cf -00AD +1160-11FF +200B c" */
   static const struct interval combining[] = {
@@ -217,15 +278,28 @@ _DEFUN (__wcwidth, (ucs),
     { 0xE0100, 0xE01EF }
   };
 
-  /* test for 8-bit control characters */
+  /* Test for NUL character */
   if (ucs == 0)
     return 0;
-  if (ucs < 32 || (ucs >= 0x7f && ucs < 0xa0))
+
+  /* Test for printable ASCII characters */
+  if (ucs >= 0x20 && ucs < 0x7f)
+    return 1;
+
+  /* Test for control characters */
+  if (ucs < 0xa0)
     return -1;
+
   /* Test for surrogate pair values. */
   if (ucs >= 0xd800 && ucs <= 0xdfff)
     return -1;
 
+  /* binary search in table of ambiguous characters */
+  if (__locale_cjk_lang ()
+      && bisearch(ucs, ambiguous,
+		  sizeof(ambiguous) / sizeof(struct interval) - 1))
+    return 2;
+
   /* binary search in table of non-spacing characters */
   if (bisearch(ucs, combining,
 	       sizeof(combining) / sizeof(struct interval) - 1))