Add the wcslcpy, wcslcat functions

These functions are about to be added to POSIX, under Austin Group
issue 986.

Reviewed-by: Siddhesh Poyarekar <siddhesh@sourceware.org>

49 files changed, 563 insertions, 0 deletions

diff --git a/debug/Makefile b/debug/Makefile
index 55e2aad..9d658e3 100644
--- a/debug/Makefile
+++ b/debug/Makefile
@@ -105,6 +105,8 @@ routines = \
   wcrtomb_chk \
   wcscat_chk \
   wcscpy_chk \
+  wcslcat_chk \
+  wcslcpy_chk \
   wcsncat_chk \
   wcsncpy_chk \
   wcsnrtombs_chk \
diff --git a/debug/Versions b/debug/Versions
index 94dfa5f..9cf2725 100644
--- a/debug/Versions
+++ b/debug/Versions
@@ -61,6 +61,8 @@ libc {
   GLIBC_2.38 {
     __strlcat_chk;
     __strlcpy_chk;
+    __wcslcat_chk;
+    __wcslcpy_chk;
   }
   GLIBC_PRIVATE {
     __fortify_fail;
diff --git a/debug/tst-fortify.c b/debug/tst-fortify.c
index 0f823a8..3744aad 100644
--- a/debug/tst-fortify.c
+++ b/debug/tst-fortify.c
@@ -783,6 +783,18 @@ do_test (void)
   CHK_FAIL_END
 
   CHK_FAIL_START
+  wcslcpy (wbuf + 7, L"X", 4);
+  CHK_FAIL_END
+
+  CHK_FAIL_START
+  wcslcpy (wbuf + 7, L"X", l0 + 4);
+  CHK_FAIL_END
+
+  CHK_FAIL_START
+  wcslcpy (wbuf + 9, L"XABCDEFGH", 8);
+  CHK_FAIL_END
+
+  CHK_FAIL_START
   wcpncpy (wbuf + 9, L"XABCDEFGH", 8);
   CHK_FAIL_END
 
@@ -804,6 +816,11 @@ do_test (void)
   wcsncat (wbuf, L"ZYXWV", l0 + 3);
   CHK_FAIL_END
 
+  wmemcpy (wbuf, wstr1 + 4, 7);
+  CHK_FAIL_START
+  wcslcat (wbuf, L"ZYXWV", l0 + 11);
+  CHK_FAIL_END
+
   CHK_FAIL_START
   wmemcpy (wa.buf1 + 1, L"abcdefghij", 10);
   CHK_FAIL_END
diff --git a/debug/wcslcat_chk.c b/debug/wcslcat_chk.c
new file mode 100644
index 0000000..8ddcc01
--- /dev/null
+++ b/debug/wcslcat_chk.c
@@ -0,0 +1,31 @@
+/* Fortified version of wcslcat.
+   Copyright (C) 2023 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library 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 C Library 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
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, see
+   <https://www.gnu.org/licenses/>.  */
+
+#include <wchar.h>
+
+/* Check that the user-supplied size does not exceed the
+   compiler-determined size, and then forward to wcslcat.  */
+size_t
+__wcslcat_chk (wchar_t *__restrict s1, const wchar_t *__restrict s2,
+               size_t n, size_t s1len)
+{
+  if (__glibc_unlikely (s1len < n))
+    __chk_fail ();
+
+  return __wcslcat (s1, s2, n);
+}
diff --git a/debug/wcslcpy_chk.c b/debug/wcslcpy_chk.c
new file mode 100644
index 0000000..077fa37
--- /dev/null
+++ b/debug/wcslcpy_chk.c
@@ -0,0 +1,31 @@
+/* Fortified version of wcslcpy.
+   Copyright (C) 2023 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library 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 C Library 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
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, see
+   <https://www.gnu.org/licenses/>.  */
+
+#include <wchar.h>
+
+/* Check that the user-supplied size does not exceed the
+   compiler-determined size, and then forward to wcslcpy.  */
+size_t
+__wcslcpy_chk (wchar_t *__restrict s1, const wchar_t *__restrict s2,
+	       size_t n, size_t s1len)
+{
+  if (__glibc_unlikely (s1len < n))
+    __chk_fail ();
+
+  return __wcslcpy (s1, s2, n);
+}
diff --git a/include/wchar.h b/include/wchar.h
index fafe7c8..ff4ae52 100644
--- a/include/wchar.h
+++ b/include/wchar.h
@@ -203,6 +203,8 @@ extern size_t __wcslen (const wchar_t *__s) __attribute_pure__;
 extern size_t __wcsnlen (const wchar_t *__s, size_t __maxlen)
      __attribute_pure__;
 extern wchar_t *__wcscat (wchar_t *dest, const wchar_t *src);
+extern __typeof (wcslcat) __wcslcat;
+libc_hidden_proto (__wcslcat)
 extern wint_t __btowc (int __c) attribute_hidden;
 extern int __mbsinit (const __mbstate_t *__ps);
 extern size_t __mbrtowc (wchar_t *__restrict __pwc,
@@ -237,8 +239,11 @@ extern wchar_t *__wcscpy (wchar_t *__restrict __dest,
 			  const wchar_t *__restrict __src)
 			  attribute_hidden __nonnull ((1, 2));
 libc_hidden_proto (__wcscpy)
+extern __typeof (wcslcpy) __wcslcpy;
+libc_hidden_proto (__wcslcpy)
 extern wchar_t *__wcsncpy (wchar_t *__restrict __dest,
 			   const wchar_t *__restrict __src, size_t __n);
+
 extern wchar_t *__wcpcpy (wchar_t *__dest, const wchar_t *__src);
 extern wchar_t *__wcpncpy (wchar_t *__dest, const wchar_t *__src,
 			   size_t __n);
diff --git a/sysdeps/mach/hurd/i386/libc.abilist b/sysdeps/mach/hurd/i386/libc.abilist
index 9b4c5f4..74a9f42 100644
--- a/sysdeps/mach/hurd/i386/libc.abilist
+++ b/sysdeps/mach/hurd/i386/libc.abilist
@@ -2328,8 +2328,12 @@ GLIBC_2.38 __isoc23_wcstoumax F
 GLIBC_2.38 __isoc23_wscanf F
 GLIBC_2.38 __strlcat_chk F
 GLIBC_2.38 __strlcpy_chk F
+GLIBC_2.38 __wcslcat_chk F
+GLIBC_2.38 __wcslcpy_chk F
 GLIBC_2.38 strlcat F
 GLIBC_2.38 strlcpy F
+GLIBC_2.38 wcslcat F
+GLIBC_2.38 wcslcpy F
 GLIBC_2.4 __confstr_chk F
 GLIBC_2.4 __fgets_chk F
 GLIBC_2.4 __fgets_unlocked_chk F
diff --git a/sysdeps/unix/sysv/linux/aarch64/libc.abilist b/sysdeps/unix/sysv/linux/aarch64/libc.abilist
index cf51b88..c49363e 100644
--- a/sysdeps/unix/sysv/linux/aarch64/libc.abilist
+++ b/sysdeps/unix/sysv/linux/aarch64/libc.abilist
@@ -2667,5 +2667,9 @@ GLIBC_2.38 __isoc23_wcstoumax F
 GLIBC_2.38 __isoc23_wscanf F
 GLIBC_2.38 __strlcat_chk F
 GLIBC_2.38 __strlcpy_chk F
+GLIBC_2.38 __wcslcat_chk F
+GLIBC_2.38 __wcslcpy_chk F
 GLIBC_2.38 strlcat F
 GLIBC_2.38 strlcpy F
+GLIBC_2.38 wcslcat F
+GLIBC_2.38 wcslcpy F
diff --git a/sysdeps/unix/sysv/linux/alpha/libc.abilist b/sysdeps/unix/sysv/linux/alpha/libc.abilist
index 4b25f34..d6b1dca 100644
--- a/sysdeps/unix/sysv/linux/alpha/libc.abilist
+++ b/sysdeps/unix/sysv/linux/alpha/libc.abilist
@@ -2776,8 +2776,12 @@ GLIBC_2.38 __nldbl___isoc23_vwscanf F
 GLIBC_2.38 __nldbl___isoc23_wscanf F
 GLIBC_2.38 __strlcat_chk F
 GLIBC_2.38 __strlcpy_chk F
+GLIBC_2.38 __wcslcat_chk F
+GLIBC_2.38 __wcslcpy_chk F
 GLIBC_2.38 strlcat F
 GLIBC_2.38 strlcpy F
+GLIBC_2.38 wcslcat F
+GLIBC_2.38 wcslcpy F
 GLIBC_2.4 _IO_fprintf F
 GLIBC_2.4 _IO_printf F
 GLIBC_2.4 _IO_sprintf F
diff --git a/sysdeps/unix/sysv/linux/arc/libc.abilist b/sysdeps/unix/sysv/linux/arc/libc.abilist
index 5a58cc0..dfe0c3f 100644
--- a/sysdeps/unix/sysv/linux/arc/libc.abilist
+++ b/sysdeps/unix/sysv/linux/arc/libc.abilist
@@ -2428,5 +2428,9 @@ GLIBC_2.38 __isoc23_wcstoumax F
 GLIBC_2.38 __isoc23_wscanf F
 GLIBC_2.38 __strlcat_chk F
 GLIBC_2.38 __strlcpy_chk F
+GLIBC_2.38 __wcslcat_chk F
+GLIBC_2.38 __wcslcpy_chk F
 GLIBC_2.38 strlcat F
 GLIBC_2.38 strlcpy F
+GLIBC_2.38 wcslcat F
+GLIBC_2.38 wcslcpy F
diff --git a/sysdeps/unix/sysv/linux/arm/be/libc.abilist b/sysdeps/unix/sysv/linux/arm/be/libc.abilist
index 99ce948..6c75e5a 100644
--- a/sysdeps/unix/sysv/linux/arm/be/libc.abilist
+++ b/sysdeps/unix/sysv/linux/arm/be/libc.abilist
@@ -548,8 +548,12 @@ GLIBC_2.38 __isoc23_wcstoumax F
 GLIBC_2.38 __isoc23_wscanf F
 GLIBC_2.38 __strlcat_chk F
 GLIBC_2.38 __strlcpy_chk F
+GLIBC_2.38 __wcslcat_chk F
+GLIBC_2.38 __wcslcpy_chk F
 GLIBC_2.38 strlcat F
 GLIBC_2.38 strlcpy F
+GLIBC_2.38 wcslcat F
+GLIBC_2.38 wcslcpy F
 GLIBC_2.4 _Exit F
 GLIBC_2.4 _IO_2_1_stderr_ D 0xa0
 GLIBC_2.4 _IO_2_1_stdin_ D 0xa0
diff --git a/sysdeps/unix/sysv/linux/arm/le/libc.abilist b/sysdeps/unix/sysv/linux/arm/le/libc.abilist
index c00bf72..03d6f7a 100644
--- a/sysdeps/unix/sysv/linux/arm/le/libc.abilist
+++ b/sysdeps/unix/sysv/linux/arm/le/libc.abilist
@@ -545,8 +545,12 @@ GLIBC_2.38 __isoc23_wcstoumax F
 GLIBC_2.38 __isoc23_wscanf F
 GLIBC_2.38 __strlcat_chk F
 GLIBC_2.38 __strlcpy_chk F
+GLIBC_2.38 __wcslcat_chk F
+GLIBC_2.38 __wcslcpy_chk F
 GLIBC_2.38 strlcat F
 GLIBC_2.38 strlcpy F
+GLIBC_2.38 wcslcat F
+GLIBC_2.38 wcslcpy F
 GLIBC_2.4 _Exit F
 GLIBC_2.4 _IO_2_1_stderr_ D 0xa0
 GLIBC_2.4 _IO_2_1_stdin_ D 0xa0
diff --git a/sysdeps/unix/sysv/linux/csky/libc.abilist b/sysdeps/unix/sysv/linux/csky/libc.abilist
index 71130f2..d858c10 100644
--- a/sysdeps/unix/sysv/linux/csky/libc.abilist
+++ b/sysdeps/unix/sysv/linux/csky/libc.abilist
@@ -2704,5 +2704,9 @@ GLIBC_2.38 __isoc23_wcstoumax F
 GLIBC_2.38 __isoc23_wscanf F
 GLIBC_2.38 __strlcat_chk F
 GLIBC_2.38 __strlcpy_chk F
+GLIBC_2.38 __wcslcat_chk F
+GLIBC_2.38 __wcslcpy_chk F
 GLIBC_2.38 strlcat F
 GLIBC_2.38 strlcpy F
+GLIBC_2.38 wcslcat F
+GLIBC_2.38 wcslcpy F
diff --git a/sysdeps/unix/sysv/linux/hppa/libc.abilist b/sysdeps/unix/sysv/linux/hppa/libc.abilist
index 5a651c0..82a14f8 100644
--- a/sysdeps/unix/sysv/linux/hppa/libc.abilist
+++ b/sysdeps/unix/sysv/linux/hppa/libc.abilist
@@ -2653,8 +2653,12 @@ GLIBC_2.38 __isoc23_wcstoumax F
 GLIBC_2.38 __isoc23_wscanf F
 GLIBC_2.38 __strlcat_chk F
 GLIBC_2.38 __strlcpy_chk F
+GLIBC_2.38 __wcslcat_chk F
+GLIBC_2.38 __wcslcpy_chk F
 GLIBC_2.38 strlcat F
 GLIBC_2.38 strlcpy F
+GLIBC_2.38 wcslcat F
+GLIBC_2.38 wcslcpy F
 GLIBC_2.4 __confstr_chk F
 GLIBC_2.4 __fgets_chk F
 GLIBC_2.4 __fgets_unlocked_chk F
diff --git a/sysdeps/unix/sysv/linux/i386/libc.abilist b/sysdeps/unix/sysv/linux/i386/libc.abilist
index 12b91ef..1950b15 100644
--- a/sysdeps/unix/sysv/linux/i386/libc.abilist
+++ b/sysdeps/unix/sysv/linux/i386/libc.abilist
@@ -2837,8 +2837,12 @@ GLIBC_2.38 __isoc23_wcstoumax F
 GLIBC_2.38 __isoc23_wscanf F
 GLIBC_2.38 __strlcat_chk F
 GLIBC_2.38 __strlcpy_chk F
+GLIBC_2.38 __wcslcat_chk F
+GLIBC_2.38 __wcslcpy_chk F
 GLIBC_2.38 strlcat F
 GLIBC_2.38 strlcpy F
+GLIBC_2.38 wcslcat F
+GLIBC_2.38 wcslcpy F
 GLIBC_2.4 __confstr_chk F
 GLIBC_2.4 __fgets_chk F
 GLIBC_2.4 __fgets_unlocked_chk F
diff --git a/sysdeps/unix/sysv/linux/ia64/libc.abilist b/sysdeps/unix/sysv/linux/ia64/libc.abilist
index f223c5e..d0b9cb2 100644
--- a/sysdeps/unix/sysv/linux/ia64/libc.abilist
+++ b/sysdeps/unix/sysv/linux/ia64/libc.abilist
@@ -2602,8 +2602,12 @@ GLIBC_2.38 __isoc23_wcstoumax F
 GLIBC_2.38 __isoc23_wscanf F
 GLIBC_2.38 __strlcat_chk F
 GLIBC_2.38 __strlcpy_chk F
+GLIBC_2.38 __wcslcat_chk F
+GLIBC_2.38 __wcslcpy_chk F
 GLIBC_2.38 strlcat F
 GLIBC_2.38 strlcpy F
+GLIBC_2.38 wcslcat F
+GLIBC_2.38 wcslcpy F
 GLIBC_2.4 __confstr_chk F
 GLIBC_2.4 __fgets_chk F
 GLIBC_2.4 __fgets_unlocked_chk F
diff --git a/sysdeps/unix/sysv/linux/loongarch/lp64/libc.abilist b/sysdeps/unix/sysv/linux/loongarch/lp64/libc.abilist
index b91ed6e..e760a63 100644
--- a/sysdeps/unix/sysv/linux/loongarch/lp64/libc.abilist
+++ b/sysdeps/unix/sysv/linux/loongarch/lp64/libc.abilist
@@ -2188,5 +2188,9 @@ GLIBC_2.38 __isoc23_wcstoumax F
 GLIBC_2.38 __isoc23_wscanf F
 GLIBC_2.38 __strlcat_chk F
 GLIBC_2.38 __strlcpy_chk F
+GLIBC_2.38 __wcslcat_chk F
+GLIBC_2.38 __wcslcpy_chk F
 GLIBC_2.38 strlcat F
 GLIBC_2.38 strlcpy F
+GLIBC_2.38 wcslcat F
+GLIBC_2.38 wcslcpy F
diff --git a/sysdeps/unix/sysv/linux/m68k/coldfire/libc.abilist b/sysdeps/unix/sysv/linux/m68k/coldfire/libc.abilist
index 0d91d7f..35785a3 100644
--- a/sysdeps/unix/sysv/linux/m68k/coldfire/libc.abilist
+++ b/sysdeps/unix/sysv/linux/m68k/coldfire/libc.abilist
@@ -549,8 +549,12 @@ GLIBC_2.38 __isoc23_wcstoumax F
 GLIBC_2.38 __isoc23_wscanf F
 GLIBC_2.38 __strlcat_chk F
 GLIBC_2.38 __strlcpy_chk F
+GLIBC_2.38 __wcslcat_chk F
+GLIBC_2.38 __wcslcpy_chk F
 GLIBC_2.38 strlcat F
 GLIBC_2.38 strlcpy F
+GLIBC_2.38 wcslcat F
+GLIBC_2.38 wcslcpy F
 GLIBC_2.4 _Exit F
 GLIBC_2.4 _IO_2_1_stderr_ D 0x98
 GLIBC_2.4 _IO_2_1_stdin_ D 0x98
diff --git a/sysdeps/unix/sysv/linux/m68k/m680x0/libc.abilist b/sysdeps/unix/sysv/linux/m68k/m680x0/libc.abilist
index e87b227..4ab2426 100644
--- a/sysdeps/unix/sysv/linux/m68k/m680x0/libc.abilist
+++ b/sysdeps/unix/sysv/linux/m68k/m680x0/libc.abilist
@@ -2780,8 +2780,12 @@ GLIBC_2.38 __isoc23_wcstoumax F
 GLIBC_2.38 __isoc23_wscanf F
 GLIBC_2.38 __strlcat_chk F
 GLIBC_2.38 __strlcpy_chk F
+GLIBC_2.38 __wcslcat_chk F
+GLIBC_2.38 __wcslcpy_chk F
 GLIBC_2.38 strlcat F
 GLIBC_2.38 strlcpy F
+GLIBC_2.38 wcslcat F
+GLIBC_2.38 wcslcpy F
 GLIBC_2.4 __confstr_chk F
 GLIBC_2.4 __fgets_chk F
 GLIBC_2.4 __fgets_unlocked_chk F
diff --git a/sysdeps/unix/sysv/linux/microblaze/be/libc.abilist b/sysdeps/unix/sysv/linux/microblaze/be/libc.abilist
index f7623d6..38faa16 100644
--- a/sysdeps/unix/sysv/linux/microblaze/be/libc.abilist
+++ b/sysdeps/unix/sysv/linux/microblaze/be/libc.abilist
@@ -2753,5 +2753,9 @@ GLIBC_2.38 __isoc23_wcstoumax F
 GLIBC_2.38 __isoc23_wscanf F
 GLIBC_2.38 __strlcat_chk F
 GLIBC_2.38 __strlcpy_chk F
+GLIBC_2.38 __wcslcat_chk F
+GLIBC_2.38 __wcslcpy_chk F
 GLIBC_2.38 strlcat F
 GLIBC_2.38 strlcpy F
+GLIBC_2.38 wcslcat F
+GLIBC_2.38 wcslcpy F
diff --git a/sysdeps/unix/sysv/linux/microblaze/le/libc.abilist b/sysdeps/unix/sysv/linux/microblaze/le/libc.abilist
index 298aa99..374d658 100644
--- a/sysdeps/unix/sysv/linux/microblaze/le/libc.abilist
+++ b/sysdeps/unix/sysv/linux/microblaze/le/libc.abilist
@@ -2750,5 +2750,9 @@ GLIBC_2.38 __isoc23_wcstoumax F
 GLIBC_2.38 __isoc23_wscanf F
 GLIBC_2.38 __strlcat_chk F
 GLIBC_2.38 __strlcpy_chk F
+GLIBC_2.38 __wcslcat_chk F
+GLIBC_2.38 __wcslcpy_chk F
 GLIBC_2.38 strlcat F
 GLIBC_2.38 strlcpy F
+GLIBC_2.38 wcslcat F
+GLIBC_2.38 wcslcpy F
diff --git a/sysdeps/unix/sysv/linux/mips/mips32/fpu/libc.abilist b/sysdeps/unix/sysv/linux/mips/mips32/fpu/libc.abilist
index f83bdc5..fcc5e88 100644
--- a/sysdeps/unix/sysv/linux/mips/mips32/fpu/libc.abilist
+++ b/sysdeps/unix/sysv/linux/mips/mips32/fpu/libc.abilist
@@ -2745,8 +2745,12 @@ GLIBC_2.38 __isoc23_wcstoumax F
 GLIBC_2.38 __isoc23_wscanf F
 GLIBC_2.38 __strlcat_chk F
 GLIBC_2.38 __strlcpy_chk F
+GLIBC_2.38 __wcslcat_chk F
+GLIBC_2.38 __wcslcpy_chk F
 GLIBC_2.38 strlcat F
 GLIBC_2.38 strlcpy F
+GLIBC_2.38 wcslcat F
+GLIBC_2.38 wcslcpy F
 GLIBC_2.4 __confstr_chk F
 GLIBC_2.4 __fgets_chk F
 GLIBC_2.4 __fgets_unlocked_chk F
diff --git a/sysdeps/unix/sysv/linux/mips/mips32/nofpu/libc.abilist b/sysdeps/unix/sysv/linux/mips/mips32/nofpu/libc.abilist
index 611ece2..01eb96c 100644
--- a/sysdeps/unix/sysv/linux/mips/mips32/nofpu/libc.abilist
+++ b/sysdeps/unix/sysv/linux/mips/mips32/nofpu/libc.abilist
@@ -2743,8 +2743,12 @@ GLIBC_2.38 __isoc23_wcstoumax F
 GLIBC_2.38 __isoc23_wscanf F
 GLIBC_2.38 __strlcat_chk F
 GLIBC_2.38 __strlcpy_chk F
+GLIBC_2.38 __wcslcat_chk F
+GLIBC_2.38 __wcslcpy_chk F
 GLIBC_2.38 strlcat F
 GLIBC_2.38 strlcpy F
+GLIBC_2.38 wcslcat F
+GLIBC_2.38 wcslcpy F
 GLIBC_2.4 __confstr_chk F
 GLIBC_2.4 __fgets_chk F
 GLIBC_2.4 __fgets_unlocked_chk F
diff --git a/sysdeps/unix/sysv/linux/mips/mips64/n32/libc.abilist b/sysdeps/unix/sysv/linux/mips/mips64/n32/libc.abilist
index 0af286f..a2748b7 100644
--- a/sysdeps/unix/sysv/linux/mips/mips64/n32/libc.abilist
+++ b/sysdeps/unix/sysv/linux/mips/mips64/n32/libc.abilist
@@ -2751,8 +2751,12 @@ GLIBC_2.38 __isoc23_wcstoumax F
 GLIBC_2.38 __isoc23_wscanf F
 GLIBC_2.38 __strlcat_chk F
 GLIBC_2.38 __strlcpy_chk F
+GLIBC_2.38 __wcslcat_chk F
+GLIBC_2.38 __wcslcpy_chk F
 GLIBC_2.38 strlcat F
 GLIBC_2.38 strlcpy F
+GLIBC_2.38 wcslcat F
+GLIBC_2.38 wcslcpy F
 GLIBC_2.4 __confstr_chk F
 GLIBC_2.4 __fgets_chk F
 GLIBC_2.4 __fgets_unlocked_chk F
diff --git a/sysdeps/unix/sysv/linux/mips/mips64/n64/libc.abilist b/sysdeps/unix/sysv/linux/mips/mips64/n64/libc.abilist
index 8285f21..0ae7ba4 100644
--- a/sysdeps/unix/sysv/linux/mips/mips64/n64/libc.abilist
+++ b/sysdeps/unix/sysv/linux/mips/mips64/n64/libc.abilist
@@ -2653,8 +2653,12 @@ GLIBC_2.38 __isoc23_wcstoumax F
 GLIBC_2.38 __isoc23_wscanf F
 GLIBC_2.38 __strlcat_chk F
 GLIBC_2.38 __strlcpy_chk F
+GLIBC_2.38 __wcslcat_chk F
+GLIBC_2.38 __wcslcpy_chk F
 GLIBC_2.38 strlcat F
 GLIBC_2.38 strlcpy F
+GLIBC_2.38 wcslcat F
+GLIBC_2.38 wcslcpy F
 GLIBC_2.4 __confstr_chk F
 GLIBC_2.4 __fgets_chk F
 GLIBC_2.4 __fgets_unlocked_chk F
diff --git a/sysdeps/unix/sysv/linux/nios2/libc.abilist b/sysdeps/unix/sysv/linux/nios2/libc.abilist
index c7144d7..947495a 100644
--- a/sysdeps/unix/sysv/linux/nios2/libc.abilist
+++ b/sysdeps/unix/sysv/linux/nios2/libc.abilist
@@ -2792,5 +2792,9 @@ GLIBC_2.38 __isoc23_wcstoumax F
 GLIBC_2.38 __isoc23_wscanf F
 GLIBC_2.38 __strlcat_chk F
 GLIBC_2.38 __strlcpy_chk F
+GLIBC_2.38 __wcslcat_chk F
+GLIBC_2.38 __wcslcpy_chk F
 GLIBC_2.38 strlcat F
 GLIBC_2.38 strlcpy F
+GLIBC_2.38 wcslcat F
+GLIBC_2.38 wcslcpy F
diff --git a/sysdeps/unix/sysv/linux/or1k/libc.abilist b/sysdeps/unix/sysv/linux/or1k/libc.abilist
index bb43247..115f103 100644
--- a/sysdeps/unix/sysv/linux/or1k/libc.abilist
+++ b/sysdeps/unix/sysv/linux/or1k/libc.abilist
@@ -2174,5 +2174,9 @@ GLIBC_2.38 __isoc23_wcstoumax F
 GLIBC_2.38 __isoc23_wscanf F
 GLIBC_2.38 __strlcat_chk F
 GLIBC_2.38 __strlcpy_chk F
+GLIBC_2.38 __wcslcat_chk F
+GLIBC_2.38 __wcslcpy_chk F
 GLIBC_2.38 strlcat F
 GLIBC_2.38 strlcpy F
+GLIBC_2.38 wcslcat F
+GLIBC_2.38 wcslcpy F
diff --git a/sysdeps/unix/sysv/linux/powerpc/powerpc32/fpu/libc.abilist b/sysdeps/unix/sysv/linux/powerpc/powerpc32/fpu/libc.abilist
index 7cc5660..19c4c32 100644
--- a/sysdeps/unix/sysv/linux/powerpc/powerpc32/fpu/libc.abilist
+++ b/sysdeps/unix/sysv/linux/powerpc/powerpc32/fpu/libc.abilist
@@ -2819,8 +2819,12 @@ GLIBC_2.38 __nldbl___isoc23_vwscanf F
 GLIBC_2.38 __nldbl___isoc23_wscanf F
 GLIBC_2.38 __strlcat_chk F
 GLIBC_2.38 __strlcpy_chk F
+GLIBC_2.38 __wcslcat_chk F
+GLIBC_2.38 __wcslcpy_chk F
 GLIBC_2.38 strlcat F
 GLIBC_2.38 strlcpy F
+GLIBC_2.38 wcslcat F
+GLIBC_2.38 wcslcpy F
 GLIBC_2.4 _IO_fprintf F
 GLIBC_2.4 _IO_printf F
 GLIBC_2.4 _IO_sprintf F
diff --git a/sysdeps/unix/sysv/linux/powerpc/powerpc32/nofpu/libc.abilist b/sysdeps/unix/sysv/linux/powerpc/powerpc32/nofpu/libc.abilist
index dd290af..3e043c4 100644
--- a/sysdeps/unix/sysv/linux/powerpc/powerpc32/nofpu/libc.abilist
+++ b/sysdeps/unix/sysv/linux/powerpc/powerpc32/nofpu/libc.abilist
@@ -2852,8 +2852,12 @@ GLIBC_2.38 __nldbl___isoc23_vwscanf F
 GLIBC_2.38 __nldbl___isoc23_wscanf F
 GLIBC_2.38 __strlcat_chk F
 GLIBC_2.38 __strlcpy_chk F
+GLIBC_2.38 __wcslcat_chk F
+GLIBC_2.38 __wcslcpy_chk F
 GLIBC_2.38 strlcat F
 GLIBC_2.38 strlcpy F
+GLIBC_2.38 wcslcat F
+GLIBC_2.38 wcslcpy F
 GLIBC_2.4 _IO_fprintf F
 GLIBC_2.4 _IO_printf F
 GLIBC_2.4 _IO_sprintf F
diff --git a/sysdeps/unix/sysv/linux/powerpc/powerpc64/be/libc.abilist b/sysdeps/unix/sysv/linux/powerpc/powerpc64/be/libc.abilist
index f2b0014..e4f3a76 100644
--- a/sysdeps/unix/sysv/linux/powerpc/powerpc64/be/libc.abilist
+++ b/sysdeps/unix/sysv/linux/powerpc/powerpc64/be/libc.abilist
@@ -2573,8 +2573,12 @@ GLIBC_2.38 __nldbl___isoc23_vwscanf F
 GLIBC_2.38 __nldbl___isoc23_wscanf F
 GLIBC_2.38 __strlcat_chk F
 GLIBC_2.38 __strlcpy_chk F
+GLIBC_2.38 __wcslcat_chk F
+GLIBC_2.38 __wcslcpy_chk F
 GLIBC_2.38 strlcat F
 GLIBC_2.38 strlcpy F
+GLIBC_2.38 wcslcat F
+GLIBC_2.38 wcslcpy F
 GLIBC_2.4 _IO_fprintf F
 GLIBC_2.4 _IO_printf F
 GLIBC_2.4 _IO_sprintf F
diff --git a/sysdeps/unix/sysv/linux/powerpc/powerpc64/le/libc.abilist b/sysdeps/unix/sysv/linux/powerpc/powerpc64/le/libc.abilist
index 9cc4316..dafe1c4 100644
--- a/sysdeps/unix/sysv/linux/powerpc/powerpc64/le/libc.abilist
+++ b/sysdeps/unix/sysv/linux/powerpc/powerpc64/le/libc.abilist
@@ -2887,5 +2887,9 @@ GLIBC_2.38 __nldbl___isoc23_vwscanf F
 GLIBC_2.38 __nldbl___isoc23_wscanf F
 GLIBC_2.38 __strlcat_chk F
 GLIBC_2.38 __strlcpy_chk F
+GLIBC_2.38 __wcslcat_chk F
+GLIBC_2.38 __wcslcpy_chk F
 GLIBC_2.38 strlcat F
 GLIBC_2.38 strlcpy F
+GLIBC_2.38 wcslcat F
+GLIBC_2.38 wcslcpy F
diff --git a/sysdeps/unix/sysv/linux/riscv/rv32/libc.abilist b/sysdeps/unix/sysv/linux/riscv/rv32/libc.abilist
index b9b725f..b9740a1 100644
--- a/sysdeps/unix/sysv/linux/riscv/rv32/libc.abilist
+++ b/sysdeps/unix/sysv/linux/riscv/rv32/libc.abilist
@@ -2430,5 +2430,9 @@ GLIBC_2.38 __isoc23_wcstoumax F
 GLIBC_2.38 __isoc23_wscanf F
 GLIBC_2.38 __strlcat_chk F
 GLIBC_2.38 __strlcpy_chk F
+GLIBC_2.38 __wcslcat_chk F
+GLIBC_2.38 __wcslcpy_chk F
 GLIBC_2.38 strlcat F
 GLIBC_2.38 strlcpy F
+GLIBC_2.38 wcslcat F
+GLIBC_2.38 wcslcpy F
diff --git a/sysdeps/unix/sysv/linux/riscv/rv64/libc.abilist b/sysdeps/unix/sysv/linux/riscv/rv64/libc.abilist
index e0f4863..e3b4656 100644
--- a/sysdeps/unix/sysv/linux/riscv/rv64/libc.abilist
+++ b/sysdeps/unix/sysv/linux/riscv/rv64/libc.abilist
@@ -2630,5 +2630,9 @@ GLIBC_2.38 __isoc23_wcstoumax F
 GLIBC_2.38 __isoc23_wscanf F
 GLIBC_2.38 __strlcat_chk F
 GLIBC_2.38 __strlcpy_chk F
+GLIBC_2.38 __wcslcat_chk F
+GLIBC_2.38 __wcslcpy_chk F
 GLIBC_2.38 strlcat F
 GLIBC_2.38 strlcpy F
+GLIBC_2.38 wcslcat F
+GLIBC_2.38 wcslcpy F
diff --git a/sysdeps/unix/sysv/linux/s390/s390-32/libc.abilist b/sysdeps/unix/sysv/linux/s390/s390-32/libc.abilist
index 8db68fc..84cb7a5 100644
--- a/sysdeps/unix/sysv/linux/s390/s390-32/libc.abilist
+++ b/sysdeps/unix/sysv/linux/s390/s390-32/libc.abilist
@@ -2817,8 +2817,12 @@ GLIBC_2.38 __nldbl___isoc23_vwscanf F
 GLIBC_2.38 __nldbl___isoc23_wscanf F
 GLIBC_2.38 __strlcat_chk F
 GLIBC_2.38 __strlcpy_chk F
+GLIBC_2.38 __wcslcat_chk F
+GLIBC_2.38 __wcslcpy_chk F
 GLIBC_2.38 strlcat F
 GLIBC_2.38 strlcpy F
+GLIBC_2.38 wcslcat F
+GLIBC_2.38 wcslcpy F
 GLIBC_2.4 _IO_fprintf F
 GLIBC_2.4 _IO_printf F
 GLIBC_2.4 _IO_sprintf F
diff --git a/sysdeps/unix/sysv/linux/s390/s390-64/libc.abilist b/sysdeps/unix/sysv/linux/s390/s390-64/libc.abilist
index ec9747b..33df3b1 100644
--- a/sysdeps/unix/sysv/linux/s390/s390-64/libc.abilist
+++ b/sysdeps/unix/sysv/linux/s390/s390-64/libc.abilist
@@ -2610,8 +2610,12 @@ GLIBC_2.38 __nldbl___isoc23_vwscanf F
 GLIBC_2.38 __nldbl___isoc23_wscanf F
 GLIBC_2.38 __strlcat_chk F
 GLIBC_2.38 __strlcpy_chk F
+GLIBC_2.38 __wcslcat_chk F
+GLIBC_2.38 __wcslcpy_chk F
 GLIBC_2.38 strlcat F
 GLIBC_2.38 strlcpy F
+GLIBC_2.38 wcslcat F
+GLIBC_2.38 wcslcpy F
 GLIBC_2.4 _IO_fprintf F
 GLIBC_2.4 _IO_printf F
 GLIBC_2.4 _IO_sprintf F
diff --git a/sysdeps/unix/sysv/linux/sh/be/libc.abilist b/sysdeps/unix/sysv/linux/sh/be/libc.abilist
index 9576b81..94cbccd 100644
--- a/sysdeps/unix/sysv/linux/sh/be/libc.abilist
+++ b/sysdeps/unix/sysv/linux/sh/be/libc.abilist
@@ -2660,8 +2660,12 @@ GLIBC_2.38 __isoc23_wcstoumax F
 GLIBC_2.38 __isoc23_wscanf F
 GLIBC_2.38 __strlcat_chk F
 GLIBC_2.38 __strlcpy_chk F
+GLIBC_2.38 __wcslcat_chk F
+GLIBC_2.38 __wcslcpy_chk F
 GLIBC_2.38 strlcat F
 GLIBC_2.38 strlcpy F
+GLIBC_2.38 wcslcat F
+GLIBC_2.38 wcslcpy F
 GLIBC_2.4 __confstr_chk F
 GLIBC_2.4 __fgets_chk F
 GLIBC_2.4 __fgets_unlocked_chk F
diff --git a/sysdeps/unix/sysv/linux/sh/le/libc.abilist b/sysdeps/unix/sysv/linux/sh/le/libc.abilist
index b67b1b2..3bb316a 100644
--- a/sysdeps/unix/sysv/linux/sh/le/libc.abilist
+++ b/sysdeps/unix/sysv/linux/sh/le/libc.abilist
@@ -2657,8 +2657,12 @@ GLIBC_2.38 __isoc23_wcstoumax F
 GLIBC_2.38 __isoc23_wscanf F
 GLIBC_2.38 __strlcat_chk F
 GLIBC_2.38 __strlcpy_chk F
+GLIBC_2.38 __wcslcat_chk F
+GLIBC_2.38 __wcslcpy_chk F
 GLIBC_2.38 strlcat F
 GLIBC_2.38 strlcpy F
+GLIBC_2.38 wcslcat F
+GLIBC_2.38 wcslcpy F
 GLIBC_2.4 __confstr_chk F
 GLIBC_2.4 __fgets_chk F
 GLIBC_2.4 __fgets_unlocked_chk F
diff --git a/sysdeps/unix/sysv/linux/sparc/sparc32/libc.abilist b/sysdeps/unix/sysv/linux/sparc/sparc32/libc.abilist
index b251fc9..6341b49 100644
--- a/sysdeps/unix/sysv/linux/sparc/sparc32/libc.abilist
+++ b/sysdeps/unix/sysv/linux/sparc/sparc32/libc.abilist
@@ -2812,8 +2812,12 @@ GLIBC_2.38 __nldbl___isoc23_vwscanf F
 GLIBC_2.38 __nldbl___isoc23_wscanf F
 GLIBC_2.38 __strlcat_chk F
 GLIBC_2.38 __strlcpy_chk F
+GLIBC_2.38 __wcslcat_chk F
+GLIBC_2.38 __wcslcpy_chk F
 GLIBC_2.38 strlcat F
 GLIBC_2.38 strlcpy F
+GLIBC_2.38 wcslcat F
+GLIBC_2.38 wcslcpy F
 GLIBC_2.4 _IO_fprintf F
 GLIBC_2.4 _IO_printf F
 GLIBC_2.4 _IO_sprintf F
diff --git a/sysdeps/unix/sysv/linux/sparc/sparc64/libc.abilist b/sysdeps/unix/sysv/linux/sparc/sparc64/libc.abilist
index 5ef9bbe..8ed1ea2 100644
--- a/sysdeps/unix/sysv/linux/sparc/sparc64/libc.abilist
+++ b/sysdeps/unix/sysv/linux/sparc/sparc64/libc.abilist
@@ -2625,8 +2625,12 @@ GLIBC_2.38 __isoc23_wcstoumax F
 GLIBC_2.38 __isoc23_wscanf F
 GLIBC_2.38 __strlcat_chk F
 GLIBC_2.38 __strlcpy_chk F
+GLIBC_2.38 __wcslcat_chk F
+GLIBC_2.38 __wcslcpy_chk F
 GLIBC_2.38 strlcat F
 GLIBC_2.38 strlcpy F
+GLIBC_2.38 wcslcat F
+GLIBC_2.38 wcslcpy F
 GLIBC_2.4 __confstr_chk F
 GLIBC_2.4 __fgets_chk F
 GLIBC_2.4 __fgets_unlocked_chk F
diff --git a/sysdeps/unix/sysv/linux/x86_64/64/libc.abilist b/sysdeps/unix/sysv/linux/x86_64/64/libc.abilist
index 9ad800b..57cfcc2 100644
--- a/sysdeps/unix/sysv/linux/x86_64/64/libc.abilist
+++ b/sysdeps/unix/sysv/linux/x86_64/64/libc.abilist
@@ -2576,8 +2576,12 @@ GLIBC_2.38 __isoc23_wcstoumax F
 GLIBC_2.38 __isoc23_wscanf F
 GLIBC_2.38 __strlcat_chk F
 GLIBC_2.38 __strlcpy_chk F
+GLIBC_2.38 __wcslcat_chk F
+GLIBC_2.38 __wcslcpy_chk F
 GLIBC_2.38 strlcat F
 GLIBC_2.38 strlcpy F
+GLIBC_2.38 wcslcat F
+GLIBC_2.38 wcslcpy F
 GLIBC_2.4 __confstr_chk F
 GLIBC_2.4 __fgets_chk F
 GLIBC_2.4 __fgets_unlocked_chk F
diff --git a/sysdeps/unix/sysv/linux/x86_64/x32/libc.abilist b/sysdeps/unix/sysv/linux/x86_64/x32/libc.abilist
index 6a3a66c..3f0a9f6 100644
--- a/sysdeps/unix/sysv/linux/x86_64/x32/libc.abilist
+++ b/sysdeps/unix/sysv/linux/x86_64/x32/libc.abilist
@@ -2682,5 +2682,9 @@ GLIBC_2.38 __isoc23_wcstoumax F
 GLIBC_2.38 __isoc23_wscanf F
 GLIBC_2.38 __strlcat_chk F
 GLIBC_2.38 __strlcpy_chk F
+GLIBC_2.38 __wcslcat_chk F
+GLIBC_2.38 __wcslcpy_chk F
 GLIBC_2.38 strlcat F
 GLIBC_2.38 strlcpy F
+GLIBC_2.38 wcslcat F
+GLIBC_2.38 wcslcpy F
diff --git a/wcsmbs/Makefile b/wcsmbs/Makefile
index ea8ea7b..d8512c8 100644
--- a/wcsmbs/Makefile
+++ b/wcsmbs/Makefile
@@ -74,6 +74,8 @@ routines := \
   wcscpy \
   wcscspn \
   wcsdup \
+  wcslcat \
+  wcslcpy \
   wcslen \
   wcsmbsload \
   wcsncase \
@@ -155,6 +157,8 @@ tests := \
   tst-wchar-h \
   tst-wcpncpy \
   tst-wcrtomb \
+  tst-wcslcat \
+  tst-wcslcpy \
   tst-wcsnlen \
   tst-wcstod-nan-locale \
   tst-wcstod-nan-sign \
diff --git a/wcsmbs/Versions b/wcsmbs/Versions
index 2d93913..7bdfe43 100644
--- a/wcsmbs/Versions
+++ b/wcsmbs/Versions
@@ -65,5 +65,7 @@ libc {
     __isoc23_vswscanf;
     __isoc23_vwscanf;
     __isoc23_wscanf;
+    wcslcat;
+    wcslcpy;
   }
 }
diff --git a/wcsmbs/bits/wchar2.h b/wcsmbs/bits/wchar2.h
index 8b41e6f..9def8e9 100644
--- a/wcsmbs/bits/wchar2.h
+++ b/wcsmbs/bits/wchar2.h
@@ -199,6 +199,45 @@ __NTH (wcsncat (wchar_t *__restrict __dest, const wchar_t *__restrict __src,
   return __wcsncat_alias (__dest, __src, __n);
 }
 
+#ifdef __USE_MISC
+extern size_t __wcslcpy_chk (wchar_t *__dest, const wchar_t *__src, size_t __n,
+			     size_t __destlen) __THROW;
+extern size_t __REDIRECT_NTH (__wcslcpy_alias,
+			      (wchar_t *__dest, const wchar_t *__src,
+			       size_t __n), wcslcpy);
+
+__fortify_function size_t
+__NTH (wcslcpy (wchar_t *__restrict __dest, const wchar_t *__restrict __src,
+		size_t __n))
+{
+  if (__glibc_objsize (__dest) != (size_t) -1
+      && (!__builtin_constant_p (__n
+				 > __glibc_objsize (__dest) / sizeof (wchar_t))
+	  || __n > __glibc_objsize (__dest) / sizeof (wchar_t)))
+    return __wcslcpy_chk (__dest, __src, __n,
+			  __glibc_objsize (__dest) / sizeof (wchar_t));
+  return __wcslcpy_alias (__dest, __src, __n);
+}
+
+extern size_t __wcslcat_chk (wchar_t *__dest, const wchar_t *__src, size_t __n,
+			     size_t __destlen) __THROW;
+extern size_t __REDIRECT_NTH (__wcslcat_alias,
+			      (wchar_t *__dest, const wchar_t *__src,
+			       size_t __n), wcslcat);
+
+__fortify_function size_t
+__NTH (wcslcat (wchar_t *__restrict __dest, const wchar_t *__restrict __src,
+		size_t __n))
+{
+  if (__glibc_objsize (__dest) != (size_t) -1
+      && (!__builtin_constant_p (__n > __glibc_objsize (__dest)
+				 / sizeof (wchar_t))
+	  || __n > __glibc_objsize (__dest) / sizeof (wchar_t)))
+    return __wcslcat_chk (__dest, __src, __n,
+			  __glibc_objsize (__dest) / sizeof (wchar_t));
+  return __wcslcat_alias (__dest, __src, __n);
+}
+#endif /* __USE_MISC */
 
 
 extern int __REDIRECT_NTH_LDBL (__swprintf_alias,
diff --git a/wcsmbs/tst-wcslcat.c b/wcsmbs/tst-wcslcat.c
new file mode 100644
index 0000000..63c3a16
--- /dev/null
+++ b/wcsmbs/tst-wcslcat.c
@@ -0,0 +1,93 @@
+/* Test the wcslcat function.
+   Copyright (C) 2023 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library 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 C Library 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
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, see
+   <https://www.gnu.org/licenses/>.  */
+
+#include <array_length.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <support/check.h>
+#include <wchar.h>
+
+static int
+do_test (void)
+{
+  struct {
+    wchar_t buf1[16];
+    wchar_t buf2[16];
+  } s;
+
+  /* Nothing is written to the destination if its size is 0.  */
+  wmemset (s.buf1, '@', array_length (s.buf1));
+  wmemset (s.buf2, '@', array_length (s.buf2));
+  TEST_COMPARE (wcslcat (s.buf1, L"", 0), 0);
+  TEST_COMPARE_BLOB (&s, sizeof (s), L"@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@", 128);
+  TEST_COMPARE (wcslcat (s.buf1, L"Hello!", 0), 6);
+  TEST_COMPARE_BLOB (&s, sizeof (s), L"@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@", 128);
+
+  /* No bytes are are modified in the target buffer if the source
+     string is short enough.  */
+  wmemset (s.buf1, '@', array_length (s.buf1));
+  wmemset (s.buf2, '@', array_length (s.buf2));
+  wcscpy (s.buf1, L"He");
+  TEST_COMPARE (wcslcat (s.buf1, L"llo!", array_length (s.buf1)), 6);
+  TEST_COMPARE_BLOB (&s, sizeof (s), L"Hello!\0@@@@@@@@@@@@@@@@@@@@@@@@@", 128);
+
+  /* A source string which fits exactly into the destination buffer is
+     not truncated.  */
+  wmemset (s.buf1, '@', array_length (s.buf1));
+  wmemset (s.buf2, '@', array_length (s.buf2));
+  wcscpy (s.buf1, L"H");
+  TEST_COMPARE (wcslcat (s.buf1, L"ello, world!!!", array_length (s.buf1)),
+                15);
+  TEST_COMPARE_BLOB (&s, sizeof (s),
+		     L"Hello, world!!!\0@@@@@@@@@@@@@@@@@@@@@@@@@", 128);
+
+  /* A source string one character longer than the destination buffer
+     is truncated by one character.  The total length is returned.  */
+  wmemset (s.buf1, '@', array_length (s.buf1));
+  wmemset (s.buf2, '@', array_length (s.buf2));
+  wcscpy (s.buf1, L"Hello");
+  TEST_COMPARE (wcslcat (s.buf1, L", world!!!!", array_length (s.buf1)), 16);
+  TEST_COMPARE_BLOB (&s, sizeof (s),
+		     L"Hello, world!!!\0@@@@@@@@@@@@@@@@@@@@@@@@@", 128);
+
+  /* An even longer source string is truncated as well, and the total
+     length is returned.  */
+  wmemset (s.buf1, '@', array_length (s.buf1));
+  wmemset (s.buf2, '@', array_length (s.buf2));
+  wcscpy (s.buf1, L"Hello,");
+  TEST_COMPARE (wcslcat (s.buf1, L" world!!!!!!!!", array_length (s.buf1)),
+                20);
+  TEST_COMPARE_BLOB (&s, sizeof (s),
+		     L"Hello, world!!!\0@@@@@@@@@@@@@@@@@@@@@@@@@", 128);
+
+  /* A destination string which is not NUL-terminated does not result
+     in any changes to the buffer.  */
+  wmemset (s.buf1, '$', array_length (s.buf1));
+  wmemset (s.buf2, '@', array_length (s.buf2));
+  TEST_COMPARE (wcslcat (s.buf1, L"", array_length (s.buf1)), 16);
+  TEST_COMPARE_BLOB (&s, sizeof (s), L"$$$$$$$$$$$$$$$$@@@@@@@@@@@@@@@@", 128);
+  TEST_COMPARE (wcslcat (s.buf1, L"Hello!", array_length (s.buf1)), 22);
+  TEST_COMPARE_BLOB (&s, sizeof (s), L"$$$$$$$$$$$$$$$$@@@@@@@@@@@@@@@@", 128);
+  TEST_COMPARE (wcslcat (s.buf1, L"Hello, world!!!!!!!!",
+                         array_length (s.buf1)), 36);
+  TEST_COMPARE_BLOB (&s, sizeof (s), L"$$$$$$$$$$$$$$$$@@@@@@@@@@@@@@@@", 128);
+
+  return 0;
+}
+
+#include <support/test-driver.c>
diff --git a/wcsmbs/tst-wcslcpy.c b/wcsmbs/tst-wcslcpy.c
new file mode 100644
index 0000000..8eaffbf
--- /dev/null
+++ b/wcsmbs/tst-wcslcpy.c
@@ -0,0 +1,78 @@
+/* Test the wcslcpy function.
+   Copyright (C) 2023 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library 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 C Library 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
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, see
+   <https://www.gnu.org/licenses/>.  */
+
+#include <array_length.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <support/check.h>
+#include <wchar.h>
+
+static int
+do_test (void)
+{
+  struct {
+    wchar_t buf1[16];
+    wchar_t buf2[16];
+  } s;
+
+  /* Nothing is written to the destination if its size is 0.  */
+  wmemset (s.buf1, '@', array_length (s.buf1));
+  wmemset (s.buf2, '@', array_length (s.buf2));
+  TEST_COMPARE (wcslcpy (s.buf1, L"Hello!", 0), 6);
+  TEST_COMPARE_BLOB (&s, sizeof (s), L"@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@", 128);
+
+  /* No bytes are are modified in the target buffer if the source
+     string is short enough.  */
+  wmemset (s.buf1, '@', array_length (s.buf1));
+  wmemset (s.buf2, '@', array_length (s.buf2));
+  TEST_COMPARE (wcslcpy (s.buf1, L"Hello!", array_length (s.buf1)), 6);
+  TEST_COMPARE_BLOB (&s, sizeof (s),
+                     L"Hello!\0@@@@@@@@@@@@@@@@@@@@@@@@@", 128);
+
+  /* A source string which fits exactly into the destination buffer is
+     not truncated.  */
+  wmemset (s.buf1, '@', array_length (s.buf1));
+  wmemset (s.buf2, '@', array_length (s.buf2));
+  TEST_COMPARE (wcslcpy (s.buf1, L"Hello, world!!!", array_length (s.buf1)),
+                15);
+  TEST_COMPARE_BLOB (&s, sizeof (s),
+                     L"Hello, world!!!\0@@@@@@@@@@@@@@@@@@@@@@@@@", 128);
+
+  /* A source string one character longer than the destination buffer
+     is truncated by one character.  The untruncated source length is
+     returned.  */
+  wmemset (s.buf1, '@', array_length (s.buf1));
+  wmemset (s.buf2, '@', array_length (s.buf2));
+  TEST_COMPARE (wcslcpy (s.buf1, L"Hello, world!!!!", array_length (s.buf1)),
+                16);
+  TEST_COMPARE_BLOB (&s, sizeof (s),
+                     L"Hello, world!!!\0@@@@@@@@@@@@@@@@@@@@@@@@@", 128);
+
+  /* An even longer source string is truncated as well, and the
+     original length is returned.  */
+  wmemset (s.buf1, '@', array_length (s.buf1));
+  wmemset (s.buf2, '@', array_length (s.buf2));
+  TEST_COMPARE (wcslcpy (s.buf1, L"Hello, world!!!!!!!!",
+                         array_length (s.buf1)), 20);
+  TEST_COMPARE_BLOB (&s, sizeof (s),
+                     L"Hello, world!!!\0@@@@@@@@@@@@@@@@@@@@@@@@@", 128);
+
+  return 0;
+}
+
+#include <support/test-driver.c>
diff --git a/wcsmbs/wchar.h b/wcsmbs/wchar.h
index d16f2e6..531b3c8 100644
--- a/wcsmbs/wchar.h
+++ b/wcsmbs/wchar.h
@@ -104,6 +104,19 @@ extern wchar_t *wcsncpy (wchar_t *__restrict __dest,
 			 const wchar_t *__restrict __src, size_t __n)
      __THROW __nonnull ((1, 2));
 
+#ifdef __USE_MISC
+/* Copy at most N - 1 characters from SRC to DEST.  */
+extern size_t wcslcpy (wchar_t *__restrict __dest,
+		       const wchar_t *__restrict __src, size_t __n)
+  __THROW __nonnull ((1, 2)) __attr_access ((__write_only__, 1, 3));
+
+/* Append SRC to DEST, possibly with truncation to keep the total size
+   below N.  */
+extern size_t wcslcat (wchar_t *__restrict __dest,
+		       const wchar_t *__restrict __src, size_t __n)
+  __THROW __nonnull ((1, 2))  __attr_access ((__read_write__, 1, 3));
+#endif
+
 /* Append SRC onto DEST.  */
 extern wchar_t *wcscat (wchar_t *__restrict __dest,
 			const wchar_t *__restrict __src)
diff --git a/wcsmbs/wcslcat.c b/wcsmbs/wcslcat.c
new file mode 100644
index 0000000..3bac6a2
--- /dev/null
+++ b/wcsmbs/wcslcat.c
@@ -0,0 +1,60 @@
+/* Append a null-terminated wide string to another, with length checking.
+   Copyright (C) 2023 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library 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 C Library 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
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, see
+   <https://www.gnu.org/licenses/>.  */
+
+#include <stdint.h>
+#include <wchar.h>
+
+size_t
+__wcslcat (wchar_t *__restrict dest, const wchar_t *__restrict src,
+           size_t size)
+{
+  size_t src_length = __wcslen (src);
+
+  /* Our implementation strlcat supports dest == NULL if size == 0
+     (for consistency with snprintf and strlcpy), but wcsnlen does
+     not, so we have to cover this case explicitly.  */
+  if (size == 0)
+    return src_length;
+
+  size_t dest_length = __wcsnlen (dest, size);
+  if (dest_length != size)
+    {
+      /* Copy at most the remaining number of characters in the
+	 destination buffer.  Leave for the null terminator.  */
+      size_t to_copy = size - dest_length - 1;
+      /* But not more than what is available in the source string.  */
+      if (to_copy > src_length)
+	to_copy = src_length;
+
+      wchar_t *target = dest + dest_length;
+      __wmemcpy (target, src, to_copy);
+      target[to_copy] = '\0';
+    }
+
+  /* If the sum wraps around, we have more than SIZE_MAX + 2 bytes in
+     the two input strings (including both null terminators).  If each
+     byte in the address space can be assigned a unique size_t value
+     (which the static_assert checks), then by the pigeonhole
+     principle, the two input strings must overlap, which is
+     undefined.  */
+  _Static_assert (sizeof (uintptr_t) == sizeof (size_t),
+		  "theoretical maximum object size covers address space");
+  return dest_length + src_length;
+}
+libc_hidden_def (__wcslcat)
+weak_alias (__wcslcat, wcslcat)
diff --git a/wcsmbs/wcslcpy.c b/wcsmbs/wcslcpy.c
new file mode 100644
index 0000000..a1b1f1b
--- /dev/null
+++ b/wcsmbs/wcslcpy.c
@@ -0,0 +1,46 @@
+/* Copy a null-terminated wide string to a fixed-size buffer.
+   Copyright (C) 2023 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library 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 C Library 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
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, see
+   <http://www.gnu.org/licenses/>.  */
+
+#include <wchar.h>
+
+size_t
+__wcslcpy (wchar_t *__restrict dest, const wchar_t *__restrict src, size_t size)
+{
+  size_t src_length = __wcslen (src);
+
+  if (__glibc_unlikely (src_length >= size))
+    {
+      if (size > 0)
+	{
+	  /* Copy the leading portion of the string.  The last
+	     character is subsequently overwritten with the null
+	     terminator, but the destination size is usually a
+	     multiple of a small power of two, so writing it twice
+	     should be more efficient than copying an odd number of
+	     character.  */
+	  __wmemcpy (dest, src, size);
+	  dest[size - 1] = '\0';
+	}
+    }
+  else
+    /* Copy the string and its terminating null character.  */
+    __wmemcpy (dest, src, src_length + 1);
+  return src_length;
+}
+libc_hidden_def (__wcslcpy)
+weak_alias (__wcslcpy, wcslcpy)