Update contrib/tools/bison to 3.1

3649391e5dae6eedaa45d736e3febbde1342c10a

1 files changed, 28 insertions, 5 deletions

diff --git a/contrib/tools/bison/lib/wcwidth.c b/contrib/tools/bison/lib/wcwidth.c
index 253fcaa656f..d33b6a9a555 100644
--- a/contrib/tools/bison/lib/wcwidth.c
+++ b/contrib/tools/bison/lib/wcwidth.c
@@ -1,5 +1,5 @@
 /* Determine the number of screen columns needed for a character.
-   Copyright (C) 2006-2007, 2010-2013 Free Software Foundation, Inc.
+   Copyright (C) 2006-2007, 2010-2018 Free Software Foundation, Inc.
 
    This program is free software: you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
@@ -12,7 +12,7 @@
    GNU General Public License for more details.
 
    You should have received a copy of the GNU General Public License
-   along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
+   along with this program.  If not, see <https://www.gnu.org/licenses/>.  */
 
 #include <config.h>
 
@@ -26,17 +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
+/* 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
     {