newlib-2.4.0: wide character strings

git-svn-id: svn://kolibrios.org@6557 a494cfbc-eb01-0410-851d-a64ba20cac60

contrib/sdk/sources/newlib/libc/string/strerror_r.c

@@ -0,0 +1,85 @@
+/* GNU variant of strerror_r. */
+/*
+FUNCTION
+	<<strerror_r>>---convert error number to string and copy to buffer
+
+INDEX
+	strerror_r
+
+ANSI_SYNOPSIS
+	#include <string.h>
+	#ifdef _GNU_SOURCE
+	char *strerror_r(int <[errnum]>, char *<[buffer]>, size_t <[n]>);
+	#else
+	int strerror_r(int <[errnum]>, char *<[buffer]>, size_t <[n]>);
+	#endif
+
+TRAD_SYNOPSIS
+	#include <string.h>
+	char *strerror_r(<[errnum]>, <[buffer]>, <[n]>)
+	int <[errnum]>;
+	char *<[buffer]>;
+	size_t <[n]>;
+
+DESCRIPTION
+<<strerror_r>> converts the error number <[errnum]> into a
+string and copies the result into the supplied <[buffer]> for
+a length up to <[n]>, including the NUL terminator. The value of
+<[errnum]> is usually a copy of <<errno>>.  If <<errnum>> is not a known
+error number, the result is the empty string.
+
+See <<strerror>> for how strings are mapped to <<errnum>>.
+
+RETURNS
+There are two variants: the GNU version always returns a NUL-terminated
+string, which is <[buffer]> if all went well, but which is another
+pointer if <[n]> was too small (leaving <[buffer]> untouched).  If the
+return is not <[buffer]>, your application must not modify that string.
+The POSIX version returns 0 on success, <[EINVAL]> if <<errnum>> was not
+recognized, and <[ERANGE]> if <[n]> was too small.  The variant chosen
+depends on macros that you define before inclusion of <<string.h>>.
+
+PORTABILITY
+<<strerror_r>> with a <[char *]> result is a GNU extension.
+<<strerror_r>> with an <[int]> result is required by POSIX 2001.
+This function is compliant only if <<_user_strerror>> is not provided,
+or if it is thread-safe and uses separate storage according to whether
+the second argument of that function is non-zero.  For more details
+on <<_user_strerror>>, see the <<strerror>> documentation.
+
+POSIX states that the contents of <[buf]> are unspecified on error,
+although this implementation guarantees a NUL-terminated string for
+all except <[n]> of 0.
+
+POSIX recommends that unknown <[errnum]> result in a message including
+that value, however it is not a requirement and this implementation
+provides only an empty string (unless you provide <<_user_strerror>>).
+POSIX also recommends that unknown <[errnum]> fail with EINVAL even
+when providing such a message, however it is not a requirement and
+this implementation will return success if <<_user_strerror>> provided
+a non-empty alternate string without assigning into its third argument.
+
+<<strerror_r>> requires no supporting OS subroutines.
+
+*/
+
+#undef __STRICT_ANSI__
+#define _GNU_SOURCE
+#include <errno.h>
+#include <string.h>
+#undef strerror_r
+
+/* For backwards-compatible linking, this must be the GNU signature;
+   see xpg_strerror_r.c for the POSIX version.  */
+char *
+_DEFUN (strerror_r, (errnum, buffer, n),
+	int errnum _AND
+	char *buffer _AND
+	size_t n)
+{
+  char *error = _strerror_r (_REENT, errnum, 1, NULL);
+
+  if (strlen (error) >= n)
+    return error;
+  return strcpy (buffer, error);
+}