summaryrefslogtreecommitdiff
path: root/lib/wcwidth.c
diff options
context:
space:
mode:
authorJörg Frings-Fürst <debian@jff.email>2022-01-08 11:51:07 +0100
committerJörg Frings-Fürst <debian@jff.email>2022-01-08 11:51:07 +0100
commitbe8efac78d067c138ad8dda03df4336e73f94887 (patch)
tree5f5254a628ba0ef72065b93d949d1c985742ea8e /lib/wcwidth.c
parent7b65dbd4ebade81d504cfe5e681292a58ad1fdf0 (diff)
New upstream version 1.0upstream/1.0
Diffstat (limited to 'lib/wcwidth.c')
-rw-r--r--lib/wcwidth.c54
1 files changed, 34 insertions, 20 deletions
diff --git a/lib/wcwidth.c b/lib/wcwidth.c
index 1e5e87cb..f99a0a61 100644
--- a/lib/wcwidth.c
+++ b/lib/wcwidth.c
@@ -1,26 +1,17 @@
/* Determine the number of screen columns needed for a character.
- Copyright (C) 2006-2007, 2010-2018 Free Software Foundation, Inc.
+ Copyright (C) 2006-2007, 2010-2022 Free Software Foundation, Inc.
- This program is free software: you can redistribute it and/or
- modify it under the terms of either:
+ This file is free software: you can redistribute it and/or modify
+ it under the terms of the GNU Lesser General Public License as
+ published by the Free Software Foundation; either version 2.1 of the
+ License, or (at your option) any later version.
- * the GNU Lesser General Public License as published by the Free
- Software Foundation; either version 3 of the License, or (at your
- option) any later version.
-
- or
-
- * the GNU General Public License as published by the Free
- Software Foundation; either version 2 of the License, or (at your
- option) any later version.
-
- or both in parallel, as here.
- This program is distributed in the hope that it will be useful,
+ This file is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
- GNU General Public License for more details.
+ GNU Lesser General Public License for more details.
- You should have received a copy of the GNU General Public License
+ You should have received a copy of the GNU Lesser General Public License
along with this program. If not, see <https://www.gnu.org/licenses/>. */
#include <config.h>
@@ -35,17 +26,40 @@
#include "streq.h"
#include "uniwidth.h"
+/* Returns 1 if the current locale is an UTF-8 locale, 0 otherwise. */
+static inline int
+is_locale_utf8 (void)
+{
+ const char *encoding = locale_charset ();
+ return STREQ_OPT (encoding, "UTF-8", 'U', 'T', 'F', '-', '8', 0, 0, 0, 0);
+}
+
+#if GNULIB_WCHAR_SINGLE_LOCALE
+/* When we know that the locale does not change, provide a speedup by
+ caching the value of is_locale_utf8. */
+static int cached_is_locale_utf8 = -1;
+static inline int
+is_locale_utf8_cached (void)
+{
+ if (cached_is_locale_utf8 < 0)
+ cached_is_locale_utf8 = is_locale_utf8 ();
+ return cached_is_locale_utf8;
+}
+#else
+/* By default, don't make assumptions, hence no caching. */
+# define is_locale_utf8_cached is_locale_utf8
+#endif
+
int
wcwidth (wchar_t wc)
#undef wcwidth
{
/* In UTF-8 locales, use a Unicode aware width function. */
- const char *encoding = locale_charset ();
- if (STREQ_OPT (encoding, "UTF-8", 'U', 'T', 'F', '-', '8', 0, 0, 0 ,0))
+ if (is_locale_utf8_cached ())
{
/* We assume that in a UTF-8 locale, a wide character is the same as a
Unicode character. */
- return uc_width (wc, encoding);
+ return uc_width (wc, "UTF-8");
}
else
{