diff mbox series

[2/3] : C++20 P0482R6 and C2X N2653: Implement mbrtoc8, c8rtomb, char8_t

Message ID a7b6eeac-4e0e-e189-8420-c9acd9ccbbe3@honermann.net
State Superseded
Headers show
Series : C++20 P0482R6 and C2X N2653: support for char8_t, mbrtoc8(), and c8rtomb(). | expand

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Commit Message

Tom Honermann Jan. 8, 2022, 12:39 a.m. UTC
This patch provides implementations for the mbrtoc8 and c8rtomb 
functions adopted for C++20 via WG21 P0482R6 [1] and proposed for C2X 
via WG14 N2653 [2]. It also provides the char8_t typedef from WG14 N2653 
[2].

The mbrtoc8 and c8rtomb functions are declared in uchar.h if either of 
the C++20 __cpp_char8_t or _GNU_SOURCE feature test macros are defined.

The char8_t typedef is declared in uchar.h if _GNU_SOURCE is defined and 
__cpp_char8_t is not defined (if __cpp_char8_t is defined, then char8_t 
is a builtin type).

Tested on Linux x86_64.

Tom.

[1]: WG21 P0482R6
      "char8_t: A type for UTF-8 characters and strings (Revision 6)"
      https://wg21.link/p0482r6

[2]: WG14 N2653
      "char8_t: A type for UTF-8 characters and strings (Revision 1)"
      http://www.open-std.org/jtc1/sc22/wg14/www/docs/n2653.htm

Comments

Joseph Myers Jan. 11, 2022, 12:53 a.m. UTC | #1
This patch is adding a NEWS entry for 2.34.  Since the next release is 
2.35, it should add an entry there instead (except we've started release 
slush for 2.35, so it might be better to aim this at 2.36).
Tom Honermann Jan. 11, 2022, 7:23 p.m. UTC | #2
On 1/10/22 7:53 PM, Joseph Myers wrote:
> This patch is adding a NEWS entry for 2.34.  Since the next release is
> 2.35, it should add an entry there instead (except we've started release
> slush for 2.35, so it might be better to aim this at 2.36).
>
Thank you for spotting that; this was due to a bad merge conflict 
resolution on my part. Fixed patch attached.

If this needs to wait for 2.36, I understand, but I would love to have 
this in 2.35 to close out this gap in C++20 support.

Tom.
Tom Honermann Jan. 20, 2022, 11:17 p.m. UTC | #3
On 1/11/22 2:23 PM, Tom Honermann via Libc-alpha wrote:
> On 1/10/22 7:53 PM, Joseph Myers wrote:
>> This patch is adding a NEWS entry for 2.34.  Since the next release is
>> 2.35, it should add an entry there instead (except we've started release
>> slush for 2.35, so it might be better to aim this at 2.36).
>>
> Thank you for spotting that; this was due to a bad merge conflict 
> resolution on my part. Fixed patch attached.
>
> If this needs to wait for 2.36, I understand, but I would love to have 
> this in 2.35 to close out this gap in C++20 support.

Any further comments on this patch series?

Tom.
Adhemerval Zanella Jan. 21, 2022, 8:01 p.m. UTC | #4
On 20/01/2022 20:17, Tom Honermann via Libc-alpha wrote:
> On 1/11/22 2:23 PM, Tom Honermann via Libc-alpha wrote:
>> On 1/10/22 7:53 PM, Joseph Myers wrote:
>>> This patch is adding a NEWS entry for 2.34.  Since the next release is
>>> 2.35, it should add an entry there instead (except we've started release
>>> slush for 2.35, so it might be better to aim this at 2.36).
>>>
>> Thank you for spotting that; this was due to a bad merge conflict resolution on my part. Fixed patch attached.
>>
>> If this needs to wait for 2.36, I understand, but I would love to have this in 2.35 to close out this gap in C++20 support.
> 
> Any further comments on this patch series?
> 
> Tom.
> 

I think it is too late for 2.35, but I will take to check when 2.36 opens.
Tom Honermann Jan. 22, 2022, 12:24 p.m. UTC | #5
On 1/21/22 3:01 PM, Adhemerval Zanella wrote:
>
> On 20/01/2022 20:17, Tom Honermann via Libc-alpha wrote:
>> On 1/11/22 2:23 PM, Tom Honermann via Libc-alpha wrote:
>>> On 1/10/22 7:53 PM, Joseph Myers wrote:
>>>> This patch is adding a NEWS entry for 2.34.  Since the next release is
>>>> 2.35, it should add an entry there instead (except we've started release
>>>> slush for 2.35, so it might be better to aim this at 2.36).
>>>>
>>> Thank you for spotting that; this was due to a bad merge conflict resolution on my part. Fixed patch attached.
>>>
>>> If this needs to wait for 2.36, I understand, but I would love to have this in 2.35 to close out this gap in C++20 support.
>> Any further comments on this patch series?
>>
>> Tom.
>>
> I think it is too late for 2.35, but I will take to check when 2.36 opens.

I understand. Thank you! I'll repost the patch series with the changes 
needed for 2.36 once 2.35 is released.

Tom.
Joseph Myers Feb. 16, 2022, 6:29 p.m. UTC | #6
On Sat, 22 Jan 2022, Tom Honermann via Libc-alpha wrote:

> I understand. Thank you! I'll repost the patch series with the changes needed
> for 2.36 once 2.35 is released.

Now that this feature has been accepted for C2X at today's WG14 meeting, a 
repost should condition the header declarations on __GLIBC_USE (ISOC2X) 
(plus whatever is appropriate for C++), as well as using 2.36 symbol 
versions, adding a NEWS entry in the 2.36 section and making that NEWS 
entry reflect that the feature is in C2X.
Guo, Wangyang via Libc-alpha Feb. 16, 2022, 7:14 p.m. UTC | #7
On Wednesday, February 16, 2022 1:29pm, "Joseph Myers" <joseph@codesourcery.com> said:



> On Sat, 22 Jan 2022, Tom Honermann via Libc-alpha wrote:
> 
> > I understand. Thank you! I'll repost the patch series with the changes
> needed
> > for 2.36 once 2.35 is released.
> 
> Now that this feature has been accepted for C2X at today's WG14 meeting, a
> repost should condition the header declarations on __GLIBC_USE (ISOC2X)
> (plus whatever is appropriate for C++), as well as using 2.36 symbol
> versions, adding a NEWS entry in the 2.36 section and making that NEWS
> entry reflect that the feature is in C2X.
 
Sounds good, thank you! I'll get a new set of patches posted soon.
 
Tom.
diff mbox series

Patch

commit 0710b1004c1eb151d739c73090c4eab81e454eb1
Author: Tom Honermann <tom@honermann.net>
Date:   Wed Jan 5 18:42:03 2022 -0500

    Implement mbrtoc8(), c8rtomb(), and the char8_t typedef.
    
    This change provides implementations for the mbrtoc8 and c8rtomb
    functions adopted for C++20 via WG21 P0482R6 and proposed for C2X
    via WG14 N2653.  It also provides the char8_t typedef from N2653.
    
    The mbrtoc8 and c8rtomb functions are declared in uchar.h if
    either of the C++20 __cpp_char8_t feature test macro or the
    _GNU_SOURCE macro are defined.
    
    The char8_t typedef is declared in uchar.h if _GNU_SOURCE is
    defined and __cpp_char8_t is not defined (if __cpp_char8_t is
    defined, then char8_t is a builtin type).

diff --git a/NEWS b/NEWS
index 4762bfcc4e..ccb22553f2 100644
--- a/NEWS
+++ b/NEWS
@@ -237,6 +237,14 @@  Major new features:
 * The audit libraries will avoid unnecessary slowdown if it is not required
   PLT tracking (by not implementing the la_pltenter or la_pltexit callbacks).
 
+* The mbrtoc8 and c8rtomb functions are added for implementation of the
+  C++20 P0482R6 and C2X N2653 proposals.  These functions perform conversions
+  between multibyte sequences and the UTF-8 character encoding.  A char8_t
+  typedef is added for the C2X N2653 proposal.  The functions are declared
+  in uchar.h if the C++20 __cpp_char8_t feature test macro or _GNU_SOURCE
+  macro is defined.  The char8_t typedef is declared in uchar.h if _GNU_SOURCE
+  is defined and __cpp_char8_t is not defined.
+
 Deprecated and removed features, and other changes affecting compatibility:
 
 * The function pthread_mutex_consistent_np has been deprecated; programs
diff --git a/sysdeps/mach/hurd/i386/libc.abilist b/sysdeps/mach/hurd/i386/libc.abilist
index ecf8c0992e..d1188a83a5 100644
--- a/sysdeps/mach/hurd/i386/libc.abilist
+++ b/sysdeps/mach/hurd/i386/libc.abilist
@@ -2287,7 +2287,9 @@  GLIBC_2.34 shm_unlink F
 GLIBC_2.34 timespec_getres F
 GLIBC_2.35 __memcmpeq F
 GLIBC_2.35 _dl_find_object F
+GLIBC_2.35 c8rtomb F
 GLIBC_2.35 close_range F
+GLIBC_2.35 mbrtoc8 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 fed942ed4b..35586c023f 100644
--- a/sysdeps/unix/sysv/linux/aarch64/libc.abilist
+++ b/sysdeps/unix/sysv/linux/aarch64/libc.abilist
@@ -2613,4 +2613,6 @@  GLIBC_2.34 tss_delete F
 GLIBC_2.34 tss_get F
 GLIBC_2.34 tss_set F
 GLIBC_2.35 __memcmpeq F
+GLIBC_2.35 c8rtomb F
 GLIBC_2.35 _dl_find_object F
+GLIBC_2.35 mbrtoc8 F
diff --git a/sysdeps/unix/sysv/linux/alpha/libc.abilist b/sysdeps/unix/sysv/linux/alpha/libc.abilist
index 2867932704..4969c57a37 100644
--- a/sysdeps/unix/sysv/linux/alpha/libc.abilist
+++ b/sysdeps/unix/sysv/linux/alpha/libc.abilist
@@ -2711,6 +2711,8 @@  GLIBC_2.34 tss_get F
 GLIBC_2.34 tss_set F
 GLIBC_2.35 __memcmpeq F
 GLIBC_2.35 _dl_find_object F
+GLIBC_2.35 c8rtomb F
+GLIBC_2.35 mbrtoc8 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 239db7bab0..fccd1f8662 100644
--- a/sysdeps/unix/sysv/linux/arc/libc.abilist
+++ b/sysdeps/unix/sysv/linux/arc/libc.abilist
@@ -2375,3 +2375,5 @@  GLIBC_2.34 tss_get F
 GLIBC_2.34 tss_set F
 GLIBC_2.35 __memcmpeq F
 GLIBC_2.35 _dl_find_object F
+GLIBC_2.35 c8rtomb F
+GLIBC_2.35 mbrtoc8 F
diff --git a/sysdeps/unix/sysv/linux/arm/be/libc.abilist b/sysdeps/unix/sysv/linux/arm/be/libc.abilist
index bc79dcfe8a..1cb2d4fd66 100644
--- a/sysdeps/unix/sysv/linux/arm/be/libc.abilist
+++ b/sysdeps/unix/sysv/linux/arm/be/libc.abilist
@@ -493,6 +493,8 @@  GLIBC_2.34 tss_get F
 GLIBC_2.34 tss_set F
 GLIBC_2.35 __memcmpeq F
 GLIBC_2.35 _dl_find_object F
+GLIBC_2.35 c8rtomb F
+GLIBC_2.35 mbrtoc8 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 614607fd6b..b36859f8e1 100644
--- a/sysdeps/unix/sysv/linux/arm/le/libc.abilist
+++ b/sysdeps/unix/sysv/linux/arm/le/libc.abilist
@@ -490,6 +490,8 @@  GLIBC_2.34 tss_get F
 GLIBC_2.34 tss_set F
 GLIBC_2.35 __memcmpeq F
 GLIBC_2.35 _dl_find_object F
+GLIBC_2.35 c8rtomb F
+GLIBC_2.35 mbrtoc8 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 2b61543f0d..4f7828d822 100644
--- a/sysdeps/unix/sysv/linux/csky/libc.abilist
+++ b/sysdeps/unix/sysv/linux/csky/libc.abilist
@@ -2649,3 +2649,5 @@  GLIBC_2.34 tss_get F
 GLIBC_2.34 tss_set F
 GLIBC_2.35 __memcmpeq F
 GLIBC_2.35 _dl_find_object F
+GLIBC_2.35 c8rtomb F
+GLIBC_2.35 mbrtoc8 F
diff --git a/sysdeps/unix/sysv/linux/hppa/libc.abilist b/sysdeps/unix/sysv/linux/hppa/libc.abilist
index 6b3cb1adb4..d59accc822 100644
--- a/sysdeps/unix/sysv/linux/hppa/libc.abilist
+++ b/sysdeps/unix/sysv/linux/hppa/libc.abilist
@@ -2598,6 +2598,8 @@  GLIBC_2.34 tss_get F
 GLIBC_2.34 tss_set F
 GLIBC_2.35 __memcmpeq F
 GLIBC_2.35 _dl_find_object F
+GLIBC_2.35 c8rtomb F
+GLIBC_2.35 mbrtoc8 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 7f608c1b64..37a065f555 100644
--- a/sysdeps/unix/sysv/linux/i386/libc.abilist
+++ b/sysdeps/unix/sysv/linux/i386/libc.abilist
@@ -2782,6 +2782,8 @@  GLIBC_2.34 tss_get F
 GLIBC_2.34 tss_set F
 GLIBC_2.35 __memcmpeq F
 GLIBC_2.35 _dl_find_object F
+GLIBC_2.35 c8rtomb F
+GLIBC_2.35 mbrtoc8 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 865deec43f..69839c86fd 100644
--- a/sysdeps/unix/sysv/linux/ia64/libc.abilist
+++ b/sysdeps/unix/sysv/linux/ia64/libc.abilist
@@ -2549,6 +2549,8 @@  GLIBC_2.34 tss_get F
 GLIBC_2.34 tss_set F
 GLIBC_2.35 __memcmpeq F
 GLIBC_2.35 _dl_find_object F
+GLIBC_2.35 c8rtomb F
+GLIBC_2.35 mbrtoc8 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/m68k/coldfire/libc.abilist b/sysdeps/unix/sysv/linux/m68k/coldfire/libc.abilist
index a172d74632..b8418d612c 100644
--- a/sysdeps/unix/sysv/linux/m68k/coldfire/libc.abilist
+++ b/sysdeps/unix/sysv/linux/m68k/coldfire/libc.abilist
@@ -494,6 +494,8 @@  GLIBC_2.34 tss_get F
 GLIBC_2.34 tss_set F
 GLIBC_2.35 __memcmpeq F
 GLIBC_2.35 _dl_find_object F
+GLIBC_2.35 c8rtomb F
+GLIBC_2.35 mbrtoc8 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 174e9c7739..8cfbb5f235 100644
--- a/sysdeps/unix/sysv/linux/m68k/m680x0/libc.abilist
+++ b/sysdeps/unix/sysv/linux/m68k/m680x0/libc.abilist
@@ -2725,6 +2725,8 @@  GLIBC_2.34 tss_get F
 GLIBC_2.34 tss_set F
 GLIBC_2.35 __memcmpeq F
 GLIBC_2.35 _dl_find_object F
+GLIBC_2.35 c8rtomb F
+GLIBC_2.35 mbrtoc8 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 d042be1369..0d729329aa 100644
--- a/sysdeps/unix/sysv/linux/microblaze/be/libc.abilist
+++ b/sysdeps/unix/sysv/linux/microblaze/be/libc.abilist
@@ -2698,3 +2698,5 @@  GLIBC_2.34 tss_get F
 GLIBC_2.34 tss_set F
 GLIBC_2.35 __memcmpeq F
 GLIBC_2.35 _dl_find_object F
+GLIBC_2.35 c8rtomb F
+GLIBC_2.35 mbrtoc8 F
diff --git a/sysdeps/unix/sysv/linux/microblaze/le/libc.abilist b/sysdeps/unix/sysv/linux/microblaze/le/libc.abilist
index 332da62de2..3980c6df0d 100644
--- a/sysdeps/unix/sysv/linux/microblaze/le/libc.abilist
+++ b/sysdeps/unix/sysv/linux/microblaze/le/libc.abilist
@@ -2695,3 +2695,5 @@  GLIBC_2.34 tss_get F
 GLIBC_2.34 tss_set F
 GLIBC_2.35 __memcmpeq F
 GLIBC_2.35 _dl_find_object F
+GLIBC_2.35 c8rtomb F
+GLIBC_2.35 mbrtoc8 F
diff --git a/sysdeps/unix/sysv/linux/mips/mips32/fpu/libc.abilist b/sysdeps/unix/sysv/linux/mips/mips32/fpu/libc.abilist
index 2d6ec0d0e8..f8c2087559 100644
--- a/sysdeps/unix/sysv/linux/mips/mips32/fpu/libc.abilist
+++ b/sysdeps/unix/sysv/linux/mips/mips32/fpu/libc.abilist
@@ -2690,6 +2690,8 @@  GLIBC_2.34 tss_get F
 GLIBC_2.34 tss_set F
 GLIBC_2.35 __memcmpeq F
 GLIBC_2.35 _dl_find_object F
+GLIBC_2.35 c8rtomb F
+GLIBC_2.35 mbrtoc8 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 6c5befa72b..ce87791286 100644
--- a/sysdeps/unix/sysv/linux/mips/mips32/nofpu/libc.abilist
+++ b/sysdeps/unix/sysv/linux/mips/mips32/nofpu/libc.abilist
@@ -2688,6 +2688,8 @@  GLIBC_2.34 tss_get F
 GLIBC_2.34 tss_set F
 GLIBC_2.35 __memcmpeq F
 GLIBC_2.35 _dl_find_object F
+GLIBC_2.35 c8rtomb F
+GLIBC_2.35 mbrtoc8 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 5fb24c97e1..ee547ceb78 100644
--- a/sysdeps/unix/sysv/linux/mips/mips64/n32/libc.abilist
+++ b/sysdeps/unix/sysv/linux/mips/mips64/n32/libc.abilist
@@ -2696,6 +2696,8 @@  GLIBC_2.34 tss_get F
 GLIBC_2.34 tss_set F
 GLIBC_2.35 __memcmpeq F
 GLIBC_2.35 _dl_find_object F
+GLIBC_2.35 c8rtomb F
+GLIBC_2.35 mbrtoc8 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 f4f29fc15e..4c558a283e 100644
--- a/sysdeps/unix/sysv/linux/mips/mips64/n64/libc.abilist
+++ b/sysdeps/unix/sysv/linux/mips/mips64/n64/libc.abilist
@@ -2600,6 +2600,8 @@  GLIBC_2.34 tss_get F
 GLIBC_2.34 tss_set F
 GLIBC_2.35 __memcmpeq F
 GLIBC_2.35 _dl_find_object F
+GLIBC_2.35 c8rtomb F
+GLIBC_2.35 mbrtoc8 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 2e7300cd05..234ab84125 100644
--- a/sysdeps/unix/sysv/linux/nios2/libc.abilist
+++ b/sysdeps/unix/sysv/linux/nios2/libc.abilist
@@ -2737,3 +2737,5 @@  GLIBC_2.34 tss_get F
 GLIBC_2.34 tss_set F
 GLIBC_2.35 __memcmpeq F
 GLIBC_2.35 _dl_find_object F
+GLIBC_2.35 c8rtomb F
+GLIBC_2.35 mbrtoc8 F
diff --git a/sysdeps/unix/sysv/linux/powerpc/powerpc32/fpu/libc.abilist b/sysdeps/unix/sysv/linux/powerpc/powerpc32/fpu/libc.abilist
index 129a2f16a7..e383bac9bd 100644
--- a/sysdeps/unix/sysv/linux/powerpc/powerpc32/fpu/libc.abilist
+++ b/sysdeps/unix/sysv/linux/powerpc/powerpc32/fpu/libc.abilist
@@ -2752,6 +2752,8 @@  GLIBC_2.34 tss_get F
 GLIBC_2.34 tss_set F
 GLIBC_2.35 __memcmpeq F
 GLIBC_2.35 _dl_find_object F
+GLIBC_2.35 c8rtomb F
+GLIBC_2.35 mbrtoc8 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 7e23226779..ddbcb3e085 100644
--- a/sysdeps/unix/sysv/linux/powerpc/powerpc32/nofpu/libc.abilist
+++ b/sysdeps/unix/sysv/linux/powerpc/powerpc32/nofpu/libc.abilist
@@ -2785,6 +2785,8 @@  GLIBC_2.34 tss_get F
 GLIBC_2.34 tss_set F
 GLIBC_2.35 __memcmpeq F
 GLIBC_2.35 _dl_find_object F
+GLIBC_2.35 c8rtomb F
+GLIBC_2.35 mbrtoc8 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 6f97392b70..daaa374fa0 100644
--- a/sysdeps/unix/sysv/linux/powerpc/powerpc64/be/libc.abilist
+++ b/sysdeps/unix/sysv/linux/powerpc/powerpc64/be/libc.abilist
@@ -2508,6 +2508,8 @@  GLIBC_2.34 tss_get F
 GLIBC_2.34 tss_set F
 GLIBC_2.35 __memcmpeq F
 GLIBC_2.35 _dl_find_object F
+GLIBC_2.35 c8rtomb F
+GLIBC_2.35 mbrtoc8 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 29058a041a..a24f6b4751 100644
--- a/sysdeps/unix/sysv/linux/powerpc/powerpc64/le/libc.abilist
+++ b/sysdeps/unix/sysv/linux/powerpc/powerpc64/le/libc.abilist
@@ -2810,3 +2810,5 @@  GLIBC_2.34 tss_get F
 GLIBC_2.34 tss_set F
 GLIBC_2.35 __memcmpeq F
 GLIBC_2.35 _dl_find_object F
+GLIBC_2.35 c8rtomb F
+GLIBC_2.35 mbrtoc8 F
diff --git a/sysdeps/unix/sysv/linux/riscv/rv32/libc.abilist b/sysdeps/unix/sysv/linux/riscv/rv32/libc.abilist
index d2924766d2..3dc0e04f64 100644
--- a/sysdeps/unix/sysv/linux/riscv/rv32/libc.abilist
+++ b/sysdeps/unix/sysv/linux/riscv/rv32/libc.abilist
@@ -2377,3 +2377,5 @@  GLIBC_2.34 tss_get F
 GLIBC_2.34 tss_set F
 GLIBC_2.35 __memcmpeq F
 GLIBC_2.35 _dl_find_object F
+GLIBC_2.35 c8rtomb F
+GLIBC_2.35 mbrtoc8 F
diff --git a/sysdeps/unix/sysv/linux/riscv/rv64/libc.abilist b/sysdeps/unix/sysv/linux/riscv/rv64/libc.abilist
index b770e05da3..af3bbfc83b 100644
--- a/sysdeps/unix/sysv/linux/riscv/rv64/libc.abilist
+++ b/sysdeps/unix/sysv/linux/riscv/rv64/libc.abilist
@@ -2577,3 +2577,5 @@  GLIBC_2.34 tss_get F
 GLIBC_2.34 tss_set F
 GLIBC_2.35 __memcmpeq F
 GLIBC_2.35 _dl_find_object F
+GLIBC_2.35 c8rtomb F
+GLIBC_2.35 mbrtoc8 F
diff --git a/sysdeps/unix/sysv/linux/s390/s390-32/libc.abilist b/sysdeps/unix/sysv/linux/s390/s390-32/libc.abilist
index bed3433a2b..4025a7f913 100644
--- a/sysdeps/unix/sysv/linux/s390/s390-32/libc.abilist
+++ b/sysdeps/unix/sysv/linux/s390/s390-32/libc.abilist
@@ -2750,6 +2750,8 @@  GLIBC_2.34 tss_get F
 GLIBC_2.34 tss_set F
 GLIBC_2.35 __memcmpeq F
 GLIBC_2.35 _dl_find_object F
+GLIBC_2.35 c8rtomb F
+GLIBC_2.35 mbrtoc8 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 4f1a143da5..55febf9508 100644
--- a/sysdeps/unix/sysv/linux/s390/s390-64/libc.abilist
+++ b/sysdeps/unix/sysv/linux/s390/s390-64/libc.abilist
@@ -2545,6 +2545,8 @@  GLIBC_2.34 tss_get F
 GLIBC_2.34 tss_set F
 GLIBC_2.35 __memcmpeq F
 GLIBC_2.35 _dl_find_object F
+GLIBC_2.35 c8rtomb F
+GLIBC_2.35 mbrtoc8 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 92c8dec8ec..cc37920ee2 100644
--- a/sysdeps/unix/sysv/linux/sh/be/libc.abilist
+++ b/sysdeps/unix/sysv/linux/sh/be/libc.abilist
@@ -2605,6 +2605,8 @@  GLIBC_2.34 tss_get F
 GLIBC_2.34 tss_set F
 GLIBC_2.35 __memcmpeq F
 GLIBC_2.35 _dl_find_object F
+GLIBC_2.35 c8rtomb F
+GLIBC_2.35 mbrtoc8 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 263da58cb7..298654b119 100644
--- a/sysdeps/unix/sysv/linux/sh/le/libc.abilist
+++ b/sysdeps/unix/sysv/linux/sh/le/libc.abilist
@@ -2602,6 +2602,8 @@  GLIBC_2.34 tss_get F
 GLIBC_2.34 tss_set F
 GLIBC_2.35 __memcmpeq F
 GLIBC_2.35 _dl_find_object F
+GLIBC_2.35 c8rtomb F
+GLIBC_2.35 mbrtoc8 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 0171efe7db..ed214429f0 100644
--- a/sysdeps/unix/sysv/linux/sparc/sparc32/libc.abilist
+++ b/sysdeps/unix/sysv/linux/sparc/sparc32/libc.abilist
@@ -2745,6 +2745,8 @@  GLIBC_2.34 tss_get F
 GLIBC_2.34 tss_set F
 GLIBC_2.35 __memcmpeq F
 GLIBC_2.35 _dl_find_object F
+GLIBC_2.35 c8rtomb F
+GLIBC_2.35 mbrtoc8 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 7f8d45f362..0dcc3674eb 100644
--- a/sysdeps/unix/sysv/linux/sparc/sparc64/libc.abilist
+++ b/sysdeps/unix/sysv/linux/sparc/sparc64/libc.abilist
@@ -2572,6 +2572,8 @@  GLIBC_2.34 tss_get F
 GLIBC_2.34 tss_set F
 GLIBC_2.35 __memcmpeq F
 GLIBC_2.35 _dl_find_object F
+GLIBC_2.35 c8rtomb F
+GLIBC_2.35 mbrtoc8 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 c2f1a8ecc6..ec4e0b73e4 100644
--- a/sysdeps/unix/sysv/linux/x86_64/64/libc.abilist
+++ b/sysdeps/unix/sysv/linux/x86_64/64/libc.abilist
@@ -2523,6 +2523,8 @@  GLIBC_2.34 tss_get F
 GLIBC_2.34 tss_set F
 GLIBC_2.35 __memcmpeq F
 GLIBC_2.35 _dl_find_object F
+GLIBC_2.35 c8rtomb F
+GLIBC_2.35 mbrtoc8 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 8b43acf100..b60cd45821 100644
--- a/sysdeps/unix/sysv/linux/x86_64/x32/libc.abilist
+++ b/sysdeps/unix/sysv/linux/x86_64/x32/libc.abilist
@@ -2629,3 +2629,5 @@  GLIBC_2.34 tss_get F
 GLIBC_2.34 tss_set F
 GLIBC_2.35 __memcmpeq F
 GLIBC_2.35 _dl_find_object F
+GLIBC_2.35 c8rtomb F
+GLIBC_2.35 mbrtoc8 F
diff --git a/wcsmbs/Makefile b/wcsmbs/Makefile
index 3a3be9cd95..390d94bbb2 100644
--- a/wcsmbs/Makefile
+++ b/wcsmbs/Makefile
@@ -42,7 +42,7 @@  routines := wcscat wcschr wcscmp wcscpy wcscspn wcsdup wcslen wcsncat \
 	    wcsmbsload mbsrtowcs_l \
 	    isoc99_wscanf isoc99_vwscanf isoc99_fwscanf isoc99_vfwscanf \
 	    isoc99_swscanf isoc99_vswscanf \
-	    mbrtoc16 c16rtomb mbrtoc32 c32rtomb
+	    mbrtoc8 c8rtomb mbrtoc16 c16rtomb mbrtoc32 c32rtomb
 
 strop-tests :=  wcscmp wcsncmp wmemcmp wcslen wcschr wcsrchr wcscpy wcsnlen \
 		wcpcpy wcsncpy wcpncpy wcscat wcsncat wcschrnul wcsspn wcspbrk \
diff --git a/wcsmbs/Versions b/wcsmbs/Versions
index 0b31c1b940..d578518fad 100644
--- a/wcsmbs/Versions
+++ b/wcsmbs/Versions
@@ -49,4 +49,7 @@  libc {
     wcstof32; wcstof64; wcstof32x;
     wcstof32_l; wcstof64_l; wcstof32x_l;
   }
+  GLIBC_2.35 {
+    c8rtomb; mbrtoc8;
+  }
 }
diff --git a/wcsmbs/c8rtomb.c b/wcsmbs/c8rtomb.c
new file mode 100644
index 0000000000..8a5ffeab23
--- /dev/null
+++ b/wcsmbs/c8rtomb.c
@@ -0,0 +1,132 @@ 
+/* UTF-8 to multibyte conversion.
+   Copyright (C) 2022 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 <errno.h>
+#include <uchar.h>
+#include <wchar.h>
+
+
+/* This is the private state used if PS is NULL.  */
+static mbstate_t state;
+
+size_t
+c8rtomb (char *s, char8_t c8, mbstate_t *ps)
+{
+  /* This implementation depends on the converter invoked by wcrtomb not
+     needing to retain state in either the top most bit of ps->__count or
+     in ps->__value between invocations.  This implementation uses the
+     top most bit of ps->__count to indicate that trailing code units are
+     expected and uses ps->__value to store previously seen code units.  */
+
+  wchar_t wc;
+
+  if (ps == NULL)
+    ps = &state;
+
+  if (s == NULL)
+    {
+      /* if 's' is a null pointer, behave as if u8'\0' was passed as 'c8'.  If
+         this occurs for an incomplete code unit sequence, then an error will
+         be reported below.  */
+      c8 = u8""[0];
+    }
+
+  if (! (ps->__count & 0x80000000))
+    {
+      /* Initial state.  */
+      if ((c8 >= 0x80 && c8 <= 0xC1) || c8 >= 0xF5)
+	{
+	  /* An invalid lead code unit.  */
+	  __set_errno (EILSEQ);
+	  return -1;
+	}
+      if (c8 >= 0xC2)
+	{
+	  /* A valid lead code unit.  */
+	  ps->__count |= 0x80000000;
+	  ps->__value.__wchb[0] = c8;
+          ps->__value.__wchb[3] = 1;
+	  return 0;
+	}
+      /* A single byte (ASCII) code unit.  */
+      wc = c8;
+    }
+  else
+    {
+      char8_t cu1 = ps->__value.__wchb[0];
+      if (ps->__value.__wchb[3] == 1)
+	{
+	  /* A single lead code unit was previously seen.  */
+	  if ((c8 < 0x80 || c8 > 0xBF) ||
+               (cu1 == 0xE0 && c8 < 0xA0) ||
+               (cu1 == 0xED && c8 > 0x9F) ||
+               (cu1 == 0xF0 && c8 < 0x90) ||
+               (cu1 == 0xF4 && c8 > 0x8F))
+	    {
+	      /* An invalid second code unit.  */
+	      __set_errno (EILSEQ);
+	      return -1;
+	    }
+	  if (cu1 >= 0xE0)
+	    {
+	      /* A three or four code unit sequence.  */
+	      ps->__value.__wchb[1] = c8;
+	      ++ps->__value.__wchb[3];
+	      return 0;
+	    }
+	  wc = ((cu1 & 0x1F) << 6) +
+	       (c8 & 0x3F);
+	}
+      else
+	{
+	  char8_t cu2 = ps->__value.__wchb[1];
+	  /* A three or four byte code unit sequence.  */
+	  if (c8 < 0x80 || c8 > 0xBF)
+	    {
+	      /* An invalid third or fourth code unit.  */
+	      __set_errno (EILSEQ);
+	      return -1;
+	    }
+	  if (ps->__value.__wchb[3] == 2 && cu1 >= 0xF0)
+	    {
+	      /* A four code unit sequence.  */
+	      ps->__value.__wchb[2] = c8;
+	      ++ps->__value.__wchb[3];
+	      return 0;
+	    }
+	  if (cu1 < 0xF0)
+	    {
+	      wc = ((cu1 & 0x0F) << 12) +
+		   ((cu2 & 0x3F) << 6) +
+		   (c8 & 0x3F);
+	    }
+	  else
+	    {
+	      char8_t cu3 = ps->__value.__wchb[2];
+	      wc = ((cu1 & 0x07) << 18) +
+		   ((cu2 & 0x3F) << 12) +
+		   ((cu3 & 0x3F) << 6) +
+		   (c8 & 0x3F);
+	    }
+	}
+      ps->__count &= 0x7fffffff;
+      ps->__value.__wch = 0;
+    }
+
+  return wcrtomb (s, wc, ps);
+}
diff --git a/wcsmbs/mbrtoc8.c b/wcsmbs/mbrtoc8.c
new file mode 100644
index 0000000000..8ca457088d
--- /dev/null
+++ b/wcsmbs/mbrtoc8.c
@@ -0,0 +1,126 @@ 
+/* Multibyte to UTF-8 conversion.
+   Copyright (C) 2022 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 <assert.h>
+#include <dlfcn.h>
+#include <errno.h>
+#include <gconv.h>
+#include <uchar.h>
+#include <wcsmbsload.h>
+
+#include <sysdep.h>
+
+#ifndef EILSEQ
+# define EILSEQ EINVAL
+#endif
+
+
+/* This is the private state used if PS is NULL.  */
+static mbstate_t state;
+
+size_t
+mbrtoc8 (char8_t *pc8, const char *s, size_t n, mbstate_t *ps)
+{
+  /* This implementation depends on the converter invoked by mbrtowc() not
+     needing to retain state in either the top most bit of ps->__count or
+     in ps->__value between invocations.  This implementation uses the
+     top most bit of ps->__count to indicate that trailing code units are
+     yet to be written and uses ps->__value to store those code units.  */
+
+  if (ps == NULL)
+    ps = &state;
+
+  /* If state indicates that trailing code units are yet to be written, write
+     those first regardless of whether 's' is a null pointer.  */
+  if (ps->__count & 0x80000000)
+    {
+      /* ps->__value.__wchb[3] stores the index of the next code unit to
+         write.  Code units are stored in reverse order.  */
+      size_t i = ps->__value.__wchb[3];
+      if (pc8 != NULL)
+	{
+	  *pc8 = ps->__value.__wchb[i];
+	}
+      if (i == 0)
+	{
+	  ps->__count &= 0x7fffffff;
+	  ps->__value.__wch = 0;
+	}
+      else
+	--ps->__value.__wchb[3];
+      return -3;
+    }
+
+  if (s == NULL)
+    {
+      /* if 's' is a null pointer, behave as if a null pointer was passed for
+         'pc8', an empty string was passed for 's', and 1 passed for 'n'.  */
+      pc8 = NULL;
+      s = "";
+      n = 1;
+    }
+
+  wchar_t wc;
+  size_t result;
+
+  result = mbrtowc(&wc, s, n, ps);
+  if (result <= n)
+    {
+      if (wc <= 0x7F)
+	{
+	  if (pc8 != NULL)
+	    *pc8 = wc;
+	}
+      else if (wc <= 0x7FF)
+	{
+	  if (pc8 != NULL)
+	    *pc8 = 0xC0 + ((wc >> 6) & 0x1F);
+	  ps->__value.__wchb[0] = 0x80 + (wc & 0x3F);
+	  ps->__value.__wchb[3] = 0;
+	  ps->__count |= 0x80000000;
+	}
+      else if (wc <= 0xFFFF)
+	{
+	  if (pc8 != NULL)
+	    *pc8 = 0xE0 + ((wc >> 12) & 0x0F);
+	  ps->__value.__wchb[1] = 0x80 + ((wc >> 6) & 0x3F);
+	  ps->__value.__wchb[0] = 0x80 + (wc & 0x3F);
+	  ps->__value.__wchb[3] = 1;
+	  ps->__count |= 0x80000000;
+	}
+      else if (wc <= 0x10FFFF)
+	{
+	  if (pc8 != NULL)
+	    *pc8 = 0xF0 + ((wc >> 18) & 0x07);
+	  ps->__value.__wchb[2] = 0x80 + ((wc >> 12) & 0x3F);
+	  ps->__value.__wchb[1] = 0x80 + ((wc >> 6) & 0x3F);
+	  ps->__value.__wchb[0] = 0x80 + (wc & 0x3F);
+	  ps->__value.__wchb[3] = 2;
+	  ps->__count |= 0x80000000;
+	}
+    }
+  if (result == 0 && wc != 0)
+    {
+      /* mbrtowc() never returns -3.  When a MB sequence converts to multiple
+         WCs, no input is consumed when writing the subsequent WCs resulting
+         in a result of 0 even if a null character wasn't written.  */
+      result = -3;
+    }
+
+  return result;
+}
diff --git a/wcsmbs/uchar.h b/wcsmbs/uchar.h
index 6020f66cf6..2f15c6f74d 100644
--- a/wcsmbs/uchar.h
+++ b/wcsmbs/uchar.h
@@ -31,6 +31,13 @@ 
 #include <bits/types.h>
 #include <bits/types/mbstate_t.h>
 
+/* Declare the char8_t typedef in _GNU_SOURCE mode, but only if the C++
+   __cpp_char8_t feature test macro is not defined.  */
+#if defined __USE_GNU && !defined __cpp_char8_t
+/* Define the 8-bit character type.  */
+typedef unsigned char char8_t;
+#endif
+
 #ifndef __USE_ISOCXX11
 /* Define the 16-bit and 32-bit character types.  */
 typedef __uint_least16_t char16_t;
@@ -40,6 +47,20 @@  typedef __uint_least32_t char32_t;
 
 __BEGIN_DECLS
 
+/* Declare mbrtoc8() and c8rtomb() in _GNU_SOURCE mode or if the C++
+   __cpp_char8_t feature test macro is defined.  */
+#if defined __USE_GNU || defined __cpp_char8_t
+/* Write char8_t representation of multibyte character pointed
+   to by S to PC8.  */
+extern size_t mbrtoc8  (char8_t *__restrict __pc8,
+			const char *__restrict __s, size_t __n,
+			mbstate_t *__restrict __p) __THROW;
+
+/* Write multibyte representation of char8_t C8 to S.  */
+extern size_t c8rtomb  (char *__restrict __s, char8_t __c8,
+			mbstate_t *__restrict __ps) __THROW;
+#endif
+
 /* Write char16_t representation of multibyte character pointed
    to by S to PC16.  */
 extern size_t mbrtoc16 (char16_t *__restrict __pc16,