Perl · t-a-k · Aug 28, 2025
diff --git a/Configure b/Configure
@@ -1052,6 +1052,7 @@ i_quadmath=''
 i_shadow=''
 i_socks=''
 i_stdbool=''
+i_stdckdint=''
 i_stdint=''
 i_stdlib=''
 i_sunmath=''
@@ -24226,6 +24227,10 @@ $rm_try
 set i_stdbool
 eval $setvar
 
+: see if C23 stdckdint is available
+set stdckdint.h i_stdckdint
+eval $inhdr
+
 : see if stdint is available
 set stdint.h i_stdint
 eval $inhdr
@@ -25636,6 +25641,7 @@ i_sgtty='$i_sgtty'
 i_shadow='$i_shadow'
 i_socks='$i_socks'
 i_stdbool='$i_stdbool'
+i_stdckdint='$i_stdckdint'
 i_stdint='$i_stdint'
 i_stdlib='$i_stdlib'
 i_sunmath='$i_sunmath'

diff --git a/Cross/config.sh-arm-linux b/Cross/config.sh-arm-linux
@@ -791,6 +791,7 @@ i_sgtty='undef'
 i_shadow='define'
 i_socks='undef'
 i_stdbool='undef'
+i_stdckdint='undef'
 i_stdint='define'
 i_stdlib='define'
 i_sunmath='undef'

diff --git a/Cross/config.sh-arm-linux-n770 b/Cross/config.sh-arm-linux-n770
@@ -789,6 +789,7 @@ i_sgtty='undef'
 i_shadow='define'
 i_socks='undef'
 i_stdbool='undef'
+i_stdckdint='undef'
 i_stdint='define'
 i_stdlib='define'
 i_sunmath='undef'

diff --git a/Porting/Glossary b/Porting/Glossary
@@ -3722,6 +3722,11 @@ i_stdbool (i_stdbool.U):
 	indicates to the C program that <stdbool.h> exists and should
 	be included.
 
+i_stdckdint (i_stdckdint.U):
+	This variable conditionally defines the I_STDCKDINT symbol, which
+	indicates to the C program that <stdckdint.h> exists and should
+	be included.
+
 i_stdint (i_stdint.U):
 	This variable conditionally defines the I_STDINT symbol, which
 	indicates to the C program that <stdint.h> exists and should

diff --git a/Porting/config.sh b/Porting/config.sh
@@ -813,6 +813,7 @@ i_sgtty='undef'
 i_shadow='define'
 i_socks='define'
 i_stdbool='define'
+i_stdckdint='undef'
 i_stdint='define'
 i_stdlib='define'
 i_sunmath='undef'

diff --git a/config_h.SH b/config_h.SH
@@ -3842,6 +3842,12 @@ sed <<!GROK!THIS! >$CONFIG_H -e 's!^#undef\(.*/\)\*!/\*#define\1 \*!' -e 's!^#un
  */
 #$i_stdbool	I_STDBOOL		/**/
 
+/* I_STDCKDINT:
+ *	This symbol, if defined, indicates that <stdckdint.h> exists and
+ *	can be included.
+ */
+#$i_stdckdint	I_STDCKDINT		/**/
+
 /* I_STDINT:
  *	This symbol, if defined, indicates that <stdint.h> exists and
  *	should be included.

diff --git a/configure.com b/configure.com
@@ -3667,6 +3667,12 @@ $   d_fd_set="define"
 $   echo4 "Well, your system knows about the normal fd_set typedef..."
 $ ENDIF
 $!
+$! Check for stdckdint.h
+$!
+$ tmp = "stdckdint.h"
+$ GOSUB inhdr
+$ i_stdckdint = tmp
+$!
 $! Check for stdint.h
 $!
 $ tmp = "stdint.h"
@@ -6550,6 +6556,7 @@ $   WC "i_stdbool='define'"
 $ ELSE
 $   WC "i_stdbool='undef'"
 $ ENDIF
+$ WC "i_stdckdint='" + i_stdckdint + "'"
 $ WC "i_stdint='" + i_stdint + "'"
 $ WC "i_stdlib='define'"
 $ WC "i_sunmath='undef'"

diff --git a/inline.h b/inline.h
@@ -3456,8 +3456,11 @@ S_lossless_NV_to_IV(const NV nv, IV *ivp)
 #    define IV_MUL_OVERFLOW_IS_EXPENSIVE (IVSIZE > PTRSIZE)
 #  endif
 
+#  ifdef I_STDCKDINT
+#    include <stdckdint.h>
+#  endif
+
 #  if defined(I_STDCKDINT) && !IV_ADD_SUB_OVERFLOW_IS_EXPENSIVE
-/* XXX Preparation for upcoming C23, but I_STDCKDINT is not yet tested */
 #    define S_iv_add_may_overflow(il, ir, result) ckd_add(result, il, ir)
 #  elif defined(HAS_BUILTIN_ADD_OVERFLOW) && !IV_ADD_SUB_OVERFLOW_IS_EXPENSIVE
 #    define S_iv_add_may_overflow __builtin_add_overflow
@@ -3485,7 +3488,6 @@ S_iv_add_may_overflow (IV il, IV ir, IV *const result)
  */
 
 #  if defined(I_STDCKDINT)
-/* XXX Preparation for upcoming C23, but I_STDCKDINT is not yet tested */
 #    define S_uv_add_overflow(auv, buv, result) ckd_add(result, auv, buv)
 #  elif defined(HAS_BUILTIN_ADD_OVERFLOW)
 #    define S_uv_add_overflow __builtin_add_overflow
@@ -3502,7 +3504,6 @@ S_uv_add_overflow (UV auv, UV buv, UV *const result)
 #  endif
 
 #  if defined(I_STDCKDINT) && !IV_ADD_SUB_OVERFLOW_IS_EXPENSIVE
-/* XXX Preparation for upcoming C23, but I_STDCKDINT is not yet tested */
 #    define S_iv_sub_may_overflow(il, ir, result) ckd_sub(result, il, ir)
 #  elif defined(HAS_BUILTIN_SUB_OVERFLOW) && !IV_ADD_SUB_OVERFLOW_IS_EXPENSIVE
 #    define S_iv_sub_may_overflow __builtin_sub_overflow
@@ -3524,7 +3525,6 @@ S_iv_sub_may_overflow (IV il, IV ir, IV *const result)
 #  endif
 
 #  if defined(I_STDCKDINT)
-/* XXX Preparation for upcoming C23, but I_STDCKDINT is not yet tested */
 #    define S_uv_sub_overflow(auv, buv, result) ckd_sub(result, auv, buv)
 #  elif defined(HAS_BUILTIN_SUB_OVERFLOW)
 #    define S_uv_sub_overflow __builtin_sub_overflow
@@ -3537,7 +3537,6 @@ S_uv_sub_overflow (UV auv, UV buv, UV *const result)
 #  endif
 
 #  if defined(I_STDCKDINT) && !IV_MUL_OVERFLOW_IS_EXPENSIVE
-/* XXX Preparation for upcoming C23, but I_STDCKDINT is not yet tested */
 #    define S_iv_mul_may_overflow(il, ir, result) ckd_mul(result, il, ir)
 #  elif defined(HAS_BUILTIN_MUL_OVERFLOW) && !IV_MUL_OVERFLOW_IS_EXPENSIVE
 #    define S_iv_mul_may_overflow __builtin_mul_overflow
@@ -3565,7 +3564,6 @@ S_iv_mul_may_overflow (IV il, IV ir, IV *const result)
 #  endif
 
 #  if defined(I_STDCKDINT)
-/* XXX Preparation for upcoming C23, but I_STDCKDINT is not yet tested */
 #    define S_uv_mul_overflow(auv, buv, result) ckd_mul(result, auv, buv)
 #  elif defined(HAS_BUILTIN_MUL_OVERFLOW)
 #    define S_uv_mul_overflow   __builtin_mul_overflow

diff --git a/plan9/config_sh.sample b/plan9/config_sh.sample
@@ -785,6 +785,7 @@ i_sgtty='undef'
 i_shadow='undef'
 i_socks='undef'
 i_stdbool='undef'
+i_stdckdint='undef'
 i_stdint='undef'
 i_stdlib='define'
 i_sunmath='undef'

diff --git a/pod/perldelta.pod b/pod/perldelta.pod
@@ -275,6 +275,10 @@ L</Platform Support> section, instead.
 
 =item *
 
+C23 F<< <stdckdint.h> >> and associated macros are now used if available.
+
+=item *
+
 XXX
 
 =back

diff --git a/win32/config.gc b/win32/config.gc
@@ -782,6 +782,7 @@ i_sgtty='undef'
 i_shadow='undef'
 i_socks='undef'
 i_stdbool='define'
+i_stdckdint='undef'
 i_stdint='define'
 i_stdlib='define'
 i_sunmath='undef'

diff --git a/win32/config.vc b/win32/config.vc
@@ -781,6 +781,7 @@ i_sgtty='undef'
 i_shadow='undef'
 i_socks='undef'
 i_stdbool='undef'
+i_stdckdint='undef'
 i_stdint='undef'
 i_stdlib='define'
 i_sunmath='undef'

diff --git a/win32/config_H.gc b/win32/config_H.gc
@@ -3801,6 +3801,12 @@
  */
 #define	I_STDBOOL		/**/
 
+/* I_STDCKDINT:
+ *	This symbol, if defined, indicates that <stdckdint.h> exists and
+ *	can be included.
+ */
+/*#define	I_STDCKDINT		/ **/
+
 /* I_STDINT:
  *	This symbol, if defined, indicates that <stdint.h> exists and
  *	should be included.

diff --git a/win32/config_H.vc b/win32/config_H.vc
@@ -3801,6 +3801,12 @@
  */
 /*#define	I_STDBOOL		/ **/
 
+/* I_STDCKDINT:
+ *	This symbol, if defined, indicates that <stdckdint.h> exists and
+ *	can be included.
+ */
+/*#define	I_STDCKDINT		/ **/
+
 /* I_STDINT:
  *	This symbol, if defined, indicates that <stdint.h> exists and
  *	should be included.
-Original file line number
+Diff line change
@@ Expand Up / @@ -275,6 +275,10 @@ L</Platform Support> section, instead. @@
     =item *
+    C23 F<< <stdckdint.h> >> and associated macros are now used if available.
+    =item *
     XXX
     =back
@@ Expand Down @@