New POSIX xlocale implementation written from scratch.

Complete in the sense that all POSIX *locale(3) and *_l(3) functions
are included, but in OpenBSD, we of course only really care about
LC_CTYPE and we only support ASCII and UTF-8.

With important help from kettenis@, guenther@, and jca@.
Repeated testing in ports bulk builds by naddy@.
Additional testing by jca@, sebastia@, dcoppa@, and others.
OK kettenis@ dcoppa@, and guenther@ on an earlier version.
Riding guenther@'s libc/librthread major bump.

3 files changed, 59 insertions, 10 deletions

diff --git a/lib/libc/time/Makefile.inc b/lib/libc/time/Makefile.inc
index f73cfbc9b56..28aada456e9 100644
--- a/lib/libc/time/Makefile.inc
+++ b/lib/libc/time/Makefile.inc
@@ -1,6 +1,7 @@
-#	$OpenBSD: Makefile.inc,v 1.10 2016/03/30 06:38:42 jmc Exp $
+#	$OpenBSD: Makefile.inc,v 1.11 2017/09/05 03:16:14 schwarze Exp $
 
 .PATH: ${LIBCSRCDIR}/time
 
-SRCS+=	asctime.c difftime.c localtime.c strftime.c strptime.c wcsftime.c
+SRCS+=	asctime.c difftime.c localtime.c strftime.c strftime_l.c \
+	strptime.c wcsftime.c
 MAN+=	ctime.3 strftime.3 time2posix.3 tzfile.5 tzset.3 strptime.3 wcsftime.3
diff --git a/lib/libc/time/strftime.3 b/lib/libc/time/strftime.3
index 00ca41604ca..a02af262b15 100644
--- a/lib/libc/time/strftime.3
+++ b/lib/libc/time/strftime.3
@@ -1,3 +1,5 @@
+.\"	$OpenBSD: strftime.3,v 1.37 2017/09/05 03:16:14 schwarze Exp $
+.\"
 .\" Copyright (c) 1989, 1991 The Regents of the University of California.
 .\" All rights reserved.
 .\"
@@ -30,22 +32,33 @@
 .\" SUCH DAMAGE.
 .\"
 .\"     from: @(#)strftime.3    5.12 (Berkeley) 6/29/91
-.\"	$OpenBSD: strftime.3,v 1.36 2016/02/08 20:29:11 jmc Exp $
 .\"
-.Dd $Mdocdate: February 8 2016 $
+.Dd $Mdocdate: September 5 2017 $
 .Dt STRFTIME 3
 .Os
 .Sh NAME
-.Nm strftime
+.Nm strftime ,
+.Nm strftime_l
 .Nd format date and time
 .Sh SYNOPSIS
 .In time.h
 .Ft size_t
-.Fn strftime "char *buf" "size_t maxsize" "const char *format" "const struct tm *timeptr"
+.Fo strftime
+.Fa "char *buf"
+.Fa "size_t maxsize"
+.Fa "const char *format"
+.Fa "const struct tm *timeptr"
+.Fc
+.Ft size_t
+.Fo strftime_l
+.Fa "char *buf"
+.Fa "size_t maxsize"
+.Fa "const char *format"
+.Fa "const struct tm *timeptr"
+.Fa "locale_t locale"
+.Fc
 .Sh DESCRIPTION
-The
-.Fn strftime
-function formats the information from
+These functions format the information from
 .Fa timeptr
 (as described in
 .Xr mktime 3 )
@@ -191,6 +204,13 @@ is replaced by the date and time in
 .Xr date 1
 format.
 .El
+.Pp
+The
+.Ox
+implementation always uses the C locale and ignores
+the global locale, the thread-specific locale, and the
+.Fa locale
+argument.
 .Sh RETURN VALUES
 If the total number of resulting characters, including the terminating
 NUL character, is not more than
@@ -199,6 +219,12 @@ NUL character, is not more than
 returns the number of characters placed in the array, not counting the
 terminating NUL.
 Otherwise, zero is returned.
+.Sh ENVIRONMENT
+On other operating systems, the behaviour of
+.Fn strftime
+may depend on the
+.Dv LC_TIME
+.Xr locale 1 .
 .Sh SEE ALSO
 .Xr date 1 ,
 .Xr printf 1 ,
@@ -215,6 +241,10 @@ The
 function
 conforms to
 .St -isoC-99 ,
+and
+.Fn strftime_l
+to
+.St -p1003.1-2008 ,
 except that the
 .Ql E
 and
@@ -253,7 +283,11 @@ first appeared in
 The
 .Fn strftime
 function has been available since
-.Bx 4.3 Reno .
+.Bx 4.3 Reno ,
+and
+.Fn strftime_l
+since
+.Ox 6.2 .
 .Sh AUTHORS
 .An Keith Bostic
 implemented the
diff --git a/lib/libc/time/strftime_l.c b/lib/libc/time/strftime_l.c
new file mode 100644
index 00000000000..4d3face1c95
--- /dev/null
+++ b/lib/libc/time/strftime_l.c
@@ -0,0 +1,14 @@
+/*	$OpenBSD: strftime_l.c,v 1.1 2017/09/05 03:16:14 schwarze Exp $ */
+/*
+ * Written in 2017 by Ingo Schwarze <schwarze@openbsd.org>.
+ * Released into the public domain.
+ */
+
+#include <time.h>
+
+size_t
+strftime_l(char *s, size_t maxsize, const char *format, const struct tm *t,
+    locale_t locale __attribute__((__unused__)))
+{
+	return strftime(s, maxsize, format, t);
+}