* wcrtomb: make multithread-safe
@ 2020-01-08 2:57 Bruno Haible
0 siblings, 0 replies; only message in thread
From: Bruno Haible @ 2020-01-08 2:57 UTC (permalink / raw)
To: bug-gnulib
The wcrtomb override is using wctomb(), which is not guaranteed to be
multithread-safe. Better use the original wcrtomb when possible.
It's not possible on IRIX, but I don't want to invest much effort into
this platform now.
Tested on the relevant platforms: 32-bit AIX, HP-UX, IRIX, Solaris 11.3,
MSVC, Android.
2020-01-07 Bruno Haible <bruno@clisp.org>
wcrtomb: Make multithread-safe, except possibly on IRIX.
* m4/wcrtomb.m4 (gl_FUNC_WCRTOMB): Don't set REPLACE_WCRTOMB to 1 when
REPLACE_MBSTATE_T is set. Define WCRTOMB_C_LOCALE_BUG and
WCRTOMB_RETVAL_BUG.
* lib/wcrtomb.c (wcrtomb): Use original wcrtomb whenever available. Use
wctomb only on IRIX.
diff --git a/lib/wcrtomb.c b/lib/wcrtomb.c
index 63d0860..06105f1 100644
--- a/lib/wcrtomb.c
+++ b/lib/wcrtomb.c
@@ -26,6 +26,7 @@
size_t
wcrtomb (char *s, wchar_t wc, mbstate_t *ps)
+#undef wcrtomb
{
/* This implementation of wcrtomb supports only stateless encodings.
ps must be in the initial state. */
@@ -35,12 +36,17 @@ wcrtomb (char *s, wchar_t wc, mbstate_t *ps)
return (size_t)(-1);
}
+#if !HAVE_WCRTOMB /* IRIX 6.5 */ \
+ || WCRTOMB_RETVAL_BUG /* Solaris 11.3, MSVC */ \
+ || WCRTOMB_C_LOCALE_BUG /* Android */
if (s == NULL)
/* We know the NUL wide character corresponds to the NUL character. */
return 1;
else
+#endif
{
-#if defined __ANDROID__
+#if HAVE_WCRTOMB
+# if WCRTOMB_C_LOCALE_BUG /* Android */
/* Implement consistently with mbrtowc(): through a 1:1 correspondence,
as in ISO-8859-1. */
if (wc >= 0 && wc <= 0xff)
@@ -48,17 +54,27 @@ wcrtomb (char *s, wchar_t wc, mbstate_t *ps)
*s = (unsigned char) wc;
return 1;
}
-#else
- /* Implement on top of wctomb(). */
+ else
+ {
+ errno = EILSEQ;
+ return (size_t)(-1);
+ }
+# else
+ return wcrtomb (s, wc, ps);
+# endif
+#else /* IRIX 6.5 */
+ /* Fallback for platforms that don't have wcrtomb().
+ Implement on top of wctomb().
+ This code is not multithread-safe. */
int ret = wctomb (s, wc);
if (ret >= 0)
return ret;
-#endif
else
{
errno = EILSEQ;
return (size_t)(-1);
}
+#endif
}
}
diff --git a/m4/wcrtomb.m4 b/m4/wcrtomb.m4
index 64e5110..c45fd98 100644
--- a/m4/wcrtomb.m4
+++ b/m4/wcrtomb.m4
@@ -1,4 +1,4 @@
-# wcrtomb.m4 serial 15
+# wcrtomb.m4 serial 16
dnl Copyright (C) 2008-2020 Free Software Foundation, Inc.
dnl This file is free software; the Free Software Foundation
dnl gives unlimited permission to copy and/or distribute it,
@@ -31,9 +31,11 @@ AC_DEFUN([gl_FUNC_WCRTOMB],
REPLACE_WCRTOMB=1
fi
else
- if test $REPLACE_MBSTATE_T = 1; then
- REPLACE_WCRTOMB=1
- fi
+ dnl We don't actually need to override wcrtomb when redefining the semantics
+ dnl of the mbstate_t type. Tested on 32-bit AIX.
+ dnl if test $REPLACE_MBSTATE_T = 1; then
+ dnl REPLACE_WCRTOMB=1
+ dnl fi
if test $REPLACE_WCRTOMB = 0; then
dnl On Android 4.3, wcrtomb produces wrong characters in the C locale.
dnl On AIX 4.3, OSF/1 5.1 and Solaris <= 11.3, wcrtomb (NULL, 0, NULL)
@@ -79,7 +81,9 @@ int main ()
])
case "$gl_cv_func_wcrtomb_works" in
*yes) ;;
- *) REPLACE_WCRTOMB=1 ;;
+ *) AC_DEFINE([WCRTOMB_C_LOCALE_BUG], [1],
+ [Define if the wcrtomb function does not work in the C locale.])
+ REPLACE_WCRTOMB=1 ;;
esac
fi
if test $REPLACE_WCRTOMB = 0; then
@@ -148,7 +152,9 @@ int main ()
])
case "$gl_cv_func_wcrtomb_retval" in
*yes) ;;
- *) REPLACE_WCRTOMB=1 ;;
+ *) AC_DEFINE([WCRTOMB_RETVAL_BUG], [1],
+ [Define if the wcrtomb function has an incorrect return value.])
+ REPLACE_WCRTOMB=1 ;;
esac
fi
fi
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