C2x strtol binary constant handling

C2x adds binary integer constants starting with 0b or 0B, and supports
those constants in strtol-family functions when the base passed is 0
or 2.  Implement that strtol support for glibc.

As discussed at
<https://sourceware.org/pipermail/libc-alpha/2020-December/120414.html>,
this is incompatible with previous C standard versions, in that such
an input string starting with 0b or 0B was previously required to be
parsed as 0 (with the rest of the string unprocessed).  Thus, as
proposed there, this patch adds 20 new __isoc23_* functions with
appropriate header redirection support.  This patch does *not* do
anything about scanf %i (which will need 12 new functions per long
double variant, so 12, 24 or 36 depending on the glibc configuration),
instead leaving that for a future patch.  The function names would
remain as __isoc23_* even if C2x ends up published in 2024 rather than
2023.

Making this change leads to the question of what should happen to
internal uses of these functions in glibc and its tests.  The header
redirection (which applies for _GNU_SOURCE or any other feature test
macros enabling C2x features) has the effect of redirecting internal
uses but without those uses then ending up at a hidden alias (see the
comment in include/stdio.h about interaction with libc_hidden_proto).
It seems desirable for the default for internal uses to be the same
versions used by normal code using _GNU_SOURCE, so rather than doing
anything to disable that redirection, similar macro definitions to
those in include/stdio.h are added to the include/ headers for the new
functions.

Given that the default for uses in glibc is for the redirections to
apply, the next question is whether the C2x semantics are correct for
all those uses.  Uses with the base fixed to 10, 16 or any other value
other than 0 or 2 can be ignored.  I think this leaves the following
internal uses to consider (an important consideration for review of
this patch will be both whether this list is complete and whether my
conclusions on all entries in it are correct):

benchtests/bench-malloc-simple.c
benchtests/bench-string.h
elf/sotruss-lib.c
math/libm-test-support.c
nptl/perf.c
nscd/nscd_conf.c
nss/nss_files/files-parse.c
posix/tst-fnmatch.c
posix/wordexp.c
resolv/inet_addr.c
rt/tst-mqueue7.c
soft-fp/testit.c
stdlib/fmtmsg.c
support/support_test_main.c
support/test-container.c
sysdeps/pthread/tst-mutex10.c

I think all of these places are OK with the new semantics, except for
resolv/inet_addr.c, where the POSIX semantics of inet_addr do not
allow for binary constants; thus, I changed that file (to use
__strtoul_internal, whose semantics are unchanged) and added a test
for this case.  In the case of posix/wordexp.c I think accepting
binary constants is OK since POSIX explicitly allows additional forms
of shell arithmetic expressions, and in stdlib/fmtmsg.c SEV_LEVEL is
not in POSIX so again I think accepting binary constants is OK.

Functions such as __strtol_internal, which are only exported for
compatibility with old binaries from when those were used in inline
functions in headers, have unchanged semantics; the __*_l_internal
versions (purely internal to libc and not exported) have a new
argument to specify whether to accept binary constants.

As well as for the standard functions, the header redirection also
applies to the *_l versions (GNU extensions), and to legacy functions
such as strtoq, to avoid confusing inconsistency (the *q functions
redirect to __isoc23_*ll rather than needing their own __isoc23_*
entry points).  For the functions that are only declared with
_GNU_SOURCE, this means the old versions are no longer available for
normal user programs at all.  An internal __GLIBC_USE_C2X_STRTOL macro
is used to control the redirections in the headers, and cases in glibc
that wish to avoid the redirections - the function implementations
themselves and the tests of the old versions of the GNU functions -
then undefine and redefine that macro to allow the old versions to be
accessed.  (There would of course be greater complexity should we wish
to make any of the old versions into compat symbols / avoid them being
defined at all for new glibc ABIs.)

strtol_l.c has some similarity to strtol.c in gnulib, but has already
diverged some way (and isn't listed at all at
https://sourceware.org/glibc/wiki/SharedSourceFiles unlike strtoll.c
and strtoul.c); I haven't made any attempts at gnulib compatibility in
the changes to that file.

I note incidentally that inttypes.h and wchar.h are missing the
__nonnull present on declarations of this family of functions in
stdlib.h; I didn't make any changes in that regard for the new
declarations added.

18 files changed, 523 insertions, 10 deletions

diff --git a/stdlib/Makefile b/stdlib/Makefile
index 83391d0..ff5096a 100644
--- a/stdlib/Makefile
+++ b/stdlib/Makefile
@@ -234,6 +234,10 @@ tests := \
   tst-strtod5 \
   tst-strtod6 \
   tst-strtol \
+  tst-strtol-binary-c11 \
+  tst-strtol-binary-c2x \
+  tst-strtol-binary-gnu11 \
+  tst-strtol-binary-gnu2x \
   tst-strtol-locale \
   tst-strtoll \
   tst-swapcontext1 \
@@ -394,6 +398,14 @@ CFLAGS-tst-makecontext2.c += $(stack-align-test-flags)
 
 CFLAGS-testmb.c += -U_FORTIFY_SOURCE -D_FORTIFY_SOURCE=2 -Wall -Werror
 
+# Some versions of GCC supported for building glibc do not support -std=c2x
+# or -std=gnu2x, so the tests for those versions use -std=c11 and -std=gnu11
+# and then _ISOC2X_SOURCE is defined in the test as needed.
+CFLAGS-tst-strtol-binary-c11.c += -std=c11
+CFLAGS-tst-strtol-binary-c2x.c += -std=c11
+CFLAGS-tst-strtol-binary-gnu11.c += -std=gnu11
+CFLAGS-tst-strtol-binary-gnu2x.c += -std=gnu11
+
 
 # Run a test on the header files we use.
 tests-special += $(objpfx)isomac.out
diff --git a/stdlib/Versions b/stdlib/Versions
index ebc4326..6a861c5 100644
--- a/stdlib/Versions
+++ b/stdlib/Versions
@@ -143,6 +143,14 @@ libc {
   }
   GLIBC_2.37 {
   }
+  GLIBC_2.38 {
+    __isoc23_strtol;
+    __isoc23_strtoll;
+    __isoc23_strtoul;
+    __isoc23_strtoull;
+    __isoc23_strtoimax;
+    __isoc23_strtoumax;
+  }
   GLIBC_PRIVATE {
     # functions which have an additional interface since they are
     # are cancelable.
diff --git a/stdlib/inttypes.h b/stdlib/inttypes.h
index 791c8e8..a5fa97b 100644
--- a/stdlib/inttypes.h
+++ b/stdlib/inttypes.h
@@ -311,6 +311,46 @@ extern uintmax_t wcstoumax (const __gwchar_t *__restrict __nptr,
 			    __gwchar_t ** __restrict __endptr, int __base)
      __THROW;
 
+/* Versions of the above functions that handle '0b' and '0B' prefixes
+   in base 0 or 2.  */
+#if __GLIBC_USE (C2X_STRTOL)
+# ifdef __REDIRECT
+extern intmax_t __REDIRECT_NTH (strtoimax, (const char *__restrict __nptr,
+					    char **__restrict __endptr,
+					    int __base), __isoc23_strtoimax);
+extern uintmax_t __REDIRECT_NTH (strtoumax, (const char *__restrict __nptr,
+					     char **__restrict __endptr,
+					     int __base), __isoc23_strtoumax);
+extern intmax_t __REDIRECT_NTH (wcstoimax,
+				(const __gwchar_t *__restrict __nptr,
+				 __gwchar_t **__restrict __endptr, int __base),
+				__isoc23_wcstoimax);
+extern uintmax_t __REDIRECT_NTH (wcstoumax,
+				 (const __gwchar_t *__restrict __nptr,
+				  __gwchar_t **__restrict __endptr, int __base),
+				 __isoc23_wcstoumax);
+# else
+extern intmax_t __isoc23_strtoimax (const char *__restrict __nptr,
+				    char **__restrict __endptr, int __base)
+     __THROW;
+extern uintmax_t __isoc23_strtoumax (const char *__restrict __nptr,
+				     char ** __restrict __endptr, int __base)
+     __THROW;
+extern intmax_t __isoc23_wcstoimax (const __gwchar_t *__restrict __nptr,
+				    __gwchar_t **__restrict __endptr,
+				    int __base)
+     __THROW;
+extern uintmax_t __isoc23_wcstoumax (const __gwchar_t *__restrict __nptr,
+				     __gwchar_t ** __restrict __endptr,
+				     int __base)
+     __THROW;
+# define strtoimax __isoc23_strtoimax
+# define strtoumax __isoc23_strtoumax
+# define wcstoimax __isoc23_wcstoimax
+# define wcstoumax __isoc23_wcstoumax
+# endif
+#endif
+
 __END_DECLS
 
 #endif /* inttypes.h */
diff --git a/stdlib/stdlib.h b/stdlib/stdlib.h
index e2c8ffb..631b0cb 100644
--- a/stdlib/stdlib.h
+++ b/stdlib/stdlib.h
@@ -208,6 +208,71 @@ extern unsigned long long int strtoull (const char *__restrict __nptr,
      __THROW __nonnull ((1));
 #endif /* ISO C99 or use MISC.  */
 
+/* Versions of the above functions that handle '0b' and '0B' prefixes
+   in base 0 or 2.  */
+#if __GLIBC_USE (C2X_STRTOL)
+# ifdef __REDIRECT
+extern long int __REDIRECT_NTH (strtol, (const char *__restrict __nptr,
+					 char **__restrict __endptr,
+					 int __base), __isoc23_strtol)
+     __nonnull ((1));
+extern unsigned long int __REDIRECT_NTH (strtoul,
+					 (const char *__restrict __nptr,
+					  char **__restrict __endptr,
+					  int __base), __isoc23_strtoul)
+     __nonnull ((1));
+#  ifdef __USE_MISC
+__extension__
+extern long long int __REDIRECT_NTH (strtoq, (const char *__restrict __nptr,
+					      char **__restrict __endptr,
+					      int __base), __isoc23_strtoll)
+     __nonnull ((1));
+__extension__
+extern unsigned long long int __REDIRECT_NTH (strtouq,
+					      (const char *__restrict __nptr,
+					       char **__restrict __endptr,
+					       int __base), __isoc23_strtoull)
+     __nonnull ((1));
+#  endif
+__extension__
+extern long long int __REDIRECT_NTH (strtoll, (const char *__restrict __nptr,
+					       char **__restrict __endptr,
+					       int __base), __isoc23_strtoll)
+     __nonnull ((1));
+__extension__
+extern unsigned long long int __REDIRECT_NTH (strtoull,
+					      (const char *__restrict __nptr,
+					       char **__restrict __endptr,
+					       int __base), __isoc23_strtoull)
+     __nonnull ((1));
+# else
+extern long int __isoc23_strtol (const char *__restrict __nptr,
+				 char **__restrict __endptr, int __base)
+     __THROW __nonnull ((1));
+extern unsigned long int __isoc23_strtoul (const char *__restrict __nptr,
+					   char **__restrict __endptr,
+					   int __base)
+     __THROW __nonnull ((1));
+__extension__
+extern long long int __isoc23_strtoll (const char *__restrict __nptr,
+				       char **__restrict __endptr, int __base)
+     __THROW __nonnull ((1));
+__extension__
+extern unsigned long long int __isoc23_strtoull (const char *__restrict __nptr,
+						 char **__restrict __endptr,
+						 int __base)
+     __THROW __nonnull ((1));
+#  define strtol __isoc23_strtol
+#  define strtoul __isoc23_strtoul
+#  ifdef __USE_MISC
+#   define strtoq __isoc23_strtoll
+#   define strtouq __isoc23_strtoull
+#  endif
+#  define strtoll __isoc23_strtoll
+#  define strtoull __isoc23_strtoull
+# endif
+#endif
+
 /* Convert a floating-point number to a string.  */
 #if __GLIBC_USE (IEC_60559_BFP_EXT_C2X)
 extern int strfromd (char *__dest, size_t __size, const char *__format,
@@ -293,6 +358,60 @@ extern unsigned long long int strtoull_l (const char *__restrict __nptr,
 					  int __base, locale_t __loc)
      __THROW __nonnull ((1, 4));
 
+/* Versions of the above functions that handle '0b' and '0B' prefixes
+   in base 0 or 2.  */
+# if __GLIBC_USE (C2X_STRTOL)
+#  ifdef __REDIRECT
+extern long int __REDIRECT_NTH (strtol_l, (const char *__restrict __nptr,
+					   char **__restrict __endptr,
+					   int __base, locale_t __loc),
+				__isoc23_strtol_l)
+     __nonnull ((1, 4));
+extern unsigned long int __REDIRECT_NTH (strtoul_l,
+					 (const char *__restrict __nptr,
+					  char **__restrict __endptr,
+					  int __base, locale_t __loc),
+					 __isoc23_strtoul_l)
+     __nonnull ((1, 4));
+__extension__
+extern long long int __REDIRECT_NTH (strtoll_l, (const char *__restrict __nptr,
+						 char **__restrict __endptr,
+						 int __base,
+						 locale_t __loc),
+				     __isoc23_strtoll_l)
+     __nonnull ((1, 4));
+__extension__
+extern unsigned long long int __REDIRECT_NTH (strtoull_l,
+					      (const char *__restrict __nptr,
+					       char **__restrict __endptr,
+					       int __base, locale_t __loc),
+					      __isoc23_strtoull_l)
+     __nonnull ((1, 4));
+#  else
+extern long int __isoc23_strtol_l (const char *__restrict __nptr,
+				   char **__restrict __endptr, int __base,
+				   locale_t __loc) __THROW __nonnull ((1, 4));
+extern unsigned long int __isoc23_strtoul_l (const char *__restrict __nptr,
+					     char **__restrict __endptr,
+					     int __base, locale_t __loc)
+     __THROW __nonnull ((1, 4));
+__extension__
+extern long long int __isoc23_strtoll_l (const char *__restrict __nptr,
+					 char **__restrict __endptr,
+					 int __base, locale_t __loc)
+     __THROW __nonnull ((1, 4));
+__extension__
+extern unsigned long long int __isoc23_strtoull_l (const char *__restrict __nptr,
+						   char **__restrict __endptr,
+						   int __base, locale_t __loc)
+     __THROW __nonnull ((1, 4));
+#   define strtol_l __isoc23_strtol_l
+#   define strtoul_l __isoc23_strtoul_l
+#   define strtoll_l __isoc23_strtoll_l
+#   define strtoull_l __isoc23_strtoull_l
+#  endif
+# endif
+
 extern double strtod_l (const char *__restrict __nptr,
 			char **__restrict __endptr, locale_t __loc)
      __THROW __nonnull ((1, 3));
diff --git a/stdlib/strtod_nan_narrow.h b/stdlib/strtod_nan_narrow.h
index 81880ac..05318f9 100644
--- a/stdlib/strtod_nan_narrow.h
+++ b/stdlib/strtod_nan_narrow.h
@@ -19,4 +19,4 @@
 #define STRING_TYPE char
 #define L_(Ch) Ch
 #define STRTOULL(S, E, B) ____strtoull_l_internal ((S), (E), (B), 0,	\
-						   _nl_C_locobj_ptr)
+						   false, _nl_C_locobj_ptr)
diff --git a/stdlib/strtod_nan_wide.h b/stdlib/strtod_nan_wide.h
index be70cf0..3ad3c98 100644
--- a/stdlib/strtod_nan_wide.h
+++ b/stdlib/strtod_nan_wide.h
@@ -19,4 +19,4 @@
 #define STRING_TYPE wchar_t
 #define L_(Ch) L##Ch
 #define STRTOULL(S, E, B) ____wcstoull_l_internal ((S), (E), (B), 0,	\
-						   _nl_C_locobj_ptr)
+						   false, _nl_C_locobj_ptr)
diff --git a/stdlib/strtol.c b/stdlib/strtol.c
index b250903..98fb0f8 100644
--- a/stdlib/strtol.c
+++ b/stdlib/strtol.c
@@ -16,6 +16,9 @@
    License along with the GNU C Library; if not, see
    <https://www.gnu.org/licenses/>.  */
 
+#include <features.h>
+#undef __GLIBC_USE_C2X_STRTOL
+#define __GLIBC_USE_C2X_STRTOL 0
 #include <stdlib.h>
 #include <wchar.h>
 #include <locale/localeinfo.h>
@@ -32,17 +35,21 @@
 #  ifdef QUAD
 #   define strtol wcstoull
 #   define __strtol_l __wcstoull_l
+#   define __isoc23_strtol __isoc23_wcstoull
 #  else
 #   define strtol wcstoul
 #   define __strtol_l __wcstoul_l
+#   define __isoc23_strtol __isoc23_wcstoul
 #  endif
 # else
 #  ifdef QUAD
 #   define strtol strtoull
 #   define __strtol_l __strtoull_l
+#   define __isoc23_strtol __isoc23_strtoull
 #  else
 #   define strtol strtoul
 #   define __strtol_l __strtoul_l
+#   define __isoc23_strtol __isoc23_strtoul
 #  endif
 # endif
 #else
@@ -50,14 +57,17 @@
 #  ifdef QUAD
 #   define strtol wcstoll
 #   define __strtol_l __wcstoll_l
+#   define __isoc23_strtol __isoc23_wcstoll
 #  else
 #   define strtol wcstol
 #   define __strtol_l __wcstol_l
+#   define __isoc23_strtol __isoc23_wcstol
 #  endif
 # else
 #  ifdef QUAD
 #   define strtol strtoll
 #   define __strtol_l __strtoll_l
+#   define __isoc23_strtol __isoc23_strtoll
 #  endif
 # endif
 #endif
@@ -88,14 +98,15 @@
 
 
 extern INT INTERNAL (__strtol_l) (const STRING_TYPE *, STRING_TYPE **, int,
-				  int, locale_t);
+				  int, bool, locale_t);
 
 
 INT
 INTERNAL (strtol) (const STRING_TYPE *nptr, STRING_TYPE **endptr,
 		   int base, int group)
 {
-  return INTERNAL (__strtol_l) (nptr, endptr, base, group, _NL_CURRENT_LOCALE);
+  return INTERNAL (__strtol_l) (nptr, endptr, base, group, false,
+				_NL_CURRENT_LOCALE);
 }
 libc_hidden_def (INTERNAL (strtol))
 
@@ -103,7 +114,16 @@ libc_hidden_def (INTERNAL (strtol))
 INT
 __strtol (const STRING_TYPE *nptr, STRING_TYPE **endptr, int base)
 {
-  return INTERNAL (__strtol_l) (nptr, endptr, base, 0, _NL_CURRENT_LOCALE);
+  return INTERNAL (__strtol_l) (nptr, endptr, base, 0, false,
+				_NL_CURRENT_LOCALE);
 }
 weak_alias (__strtol, strtol)
 libc_hidden_weak (strtol)
+
+INT
+__isoc23_strtol (const STRING_TYPE *nptr, STRING_TYPE **endptr, int base)
+{
+  return INTERNAL (__strtol_l) (nptr, endptr, base, 0, true,
+				_NL_CURRENT_LOCALE);
+}
+libc_hidden_def (__isoc23_strtol)
diff --git a/stdlib/strtol_l.c b/stdlib/strtol_l.c
index edbade1..3424c3f 100644
--- a/stdlib/strtol_l.c
+++ b/stdlib/strtol_l.c
@@ -16,6 +16,9 @@
    License along with the GNU C Library; if not, see
    <https://www.gnu.org/licenses/>.  */
 
+#include <features.h>
+#undef __GLIBC_USE_C2X_STRTOL
+#define __GLIBC_USE_C2X_STRTOL 0
 
 #if HAVE_CONFIG_H
 # include <config.h>
@@ -61,28 +64,36 @@
 # ifdef USE_WIDE_CHAR
 #  ifdef QUAD
 #   define strtol_l wcstoull_l
+#   define __isoc23_strtol_l __isoc23_wcstoull_l
 #  else
 #   define strtol_l wcstoul_l
+#   define __isoc23_strtol_l __isoc23_wcstoul_l
 #  endif
 # else
 #  ifdef QUAD
 #   define strtol_l strtoull_l
+#   define __isoc23_strtol_l __isoc23_strtoull_l
 #  else
 #   define strtol_l strtoul_l
+#   define __isoc23_strtol_l __isoc23_strtoul_l
 #  endif
 # endif
 #else
 # ifdef USE_WIDE_CHAR
 #  ifdef QUAD
 #   define strtol_l wcstoll_l
+#   define __isoc23_strtol_l __isoc23_wcstoll_l
 #  else
 #   define strtol_l wcstol_l
+#   define __isoc23_strtol_l __isoc23_wcstol_l
 #  endif
 # else
 #  ifdef QUAD
 #   define strtol_l strtoll_l
+#   define __isoc23_strtol_l __isoc23_strtoll_l
 #  else
 #   define strtol_l strtol_l
+#   define __isoc23_strtol_l __isoc23_strtol_l
 #  endif
 # endif
 #endif
@@ -216,12 +227,14 @@ extern const unsigned char __strtol_ull_rem_tab[] attribute_hidden;
    If BASE is 0 the base is determined by the presence of a leading
    zero, indicating octal or a leading "0x" or "0X", indicating hexadecimal.
    If BASE is < 2 or > 36, it is reset to 10.
+   If BIN_CST is true, binary constants starting "0b" or "0B" are accepted
+   in base 0 and 2.
    If ENDPTR is not NULL, a pointer to the character after the last
    one converted is stored in *ENDPTR.  */
 
 INT
 INTERNAL (__strtol_l) (const STRING_TYPE *nptr, STRING_TYPE **endptr,
-		       int base, int group, locale_t loc)
+		       int base, int group, bool bin_cst, locale_t loc)
 {
   int negative;
   unsigned LONG int cutoff;
@@ -311,6 +324,11 @@ INTERNAL (__strtol_l) (const STRING_TYPE *nptr, STRING_TYPE **endptr,
 	  s += 2;
 	  base = 16;
 	}
+      else if (bin_cst && (base == 0 || base == 2) && TOUPPER (s[1]) == L_('B'))
+	{
+	  s += 2;
+	  base = 2;
+	}
       else if (base == 0)
 	base = 8;
     }
@@ -543,7 +561,15 @@ weak_function
 __strtol_l (const STRING_TYPE *nptr, STRING_TYPE **endptr,
 	    int base, locale_t loc)
 {
-  return INTERNAL (__strtol_l) (nptr, endptr, base, 0, loc);
+  return INTERNAL (__strtol_l) (nptr, endptr, base, 0, false, loc);
 }
 libc_hidden_def (__strtol_l)
 weak_alias (__strtol_l, strtol_l)
+
+INT
+__isoc23_strtol_l (const STRING_TYPE *nptr, STRING_TYPE **endptr,
+		   int base, locale_t loc)
+{
+  return INTERNAL (__strtol_l) (nptr, endptr, base, 0, true, loc);
+}
+libc_hidden_def (__isoc23_strtol_l)
diff --git a/stdlib/strtoll.c b/stdlib/strtoll.c
index a273ca4..63fdf29 100644
--- a/stdlib/strtoll.c
+++ b/stdlib/strtoll.c
@@ -31,4 +31,5 @@ compat_symbol (libc, __strtoll_internal, __strtoq_internal, GLIBC_2_0);
 # endif
 weak_alias (strtoll, strtoq)
 weak_alias (strtoll, strtoimax)
+weak_alias (__isoc23_strtoll, __isoc23_strtoimax)
 #endif
diff --git a/stdlib/strtoll_l.c b/stdlib/strtoll_l.c
index 32ceda0..e4a3ac0 100644
--- a/stdlib/strtoll_l.c
+++ b/stdlib/strtoll_l.c
@@ -18,9 +18,13 @@
 
 #define QUAD	1
 
+#include <features.h>
+#undef __GLIBC_USE_C2X_STRTOL
+#define __GLIBC_USE_C2X_STRTOL 0
 #include <locale.h>
+#include <stdbool.h>
 
 extern long long int ____strtoll_l_internal (const char *, char **, int, int,
-					     locale_t);
+					     bool, locale_t);
 
 #include <strtol_l.c>
diff --git a/stdlib/strtoul_l.c b/stdlib/strtoul_l.c
index f1bd050..a92a5ce 100644
--- a/stdlib/strtoul_l.c
+++ b/stdlib/strtoul_l.c
@@ -18,9 +18,13 @@
 
 #define UNSIGNED	1
 
+#include <features.h>
+#undef __GLIBC_USE_C2X_STRTOL
+#define __GLIBC_USE_C2X_STRTOL 0
 #include <locale.h>
+#include <stdbool.h>
 
 extern unsigned long int ____strtoul_l_internal (const char *, char **, int,
-						 int, locale_t);
+						 int, bool, locale_t);
 
 #include "strtol_l.c"
diff --git a/stdlib/strtoull.c b/stdlib/strtoull.c
index 51859db..6c9afa3 100644
--- a/stdlib/strtoull.c
+++ b/stdlib/strtoull.c
@@ -31,4 +31,5 @@ compat_symbol (libc, __strtoull_internal, __strtouq_internal, GLIBC_2_0);
 # endif
 weak_alias (strtoull, strtouq)
 weak_alias (strtoull, strtoumax)
+weak_alias (__isoc23_strtoull, __isoc23_strtoumax)
 #endif
diff --git a/stdlib/strtoull_l.c b/stdlib/strtoull_l.c
index ef102dd..2be4007 100644
--- a/stdlib/strtoull_l.c
+++ b/stdlib/strtoull_l.c
@@ -19,9 +19,14 @@
 #define QUAD		1
 #define UNSIGNED	1
 
+#include <features.h>
+#undef __GLIBC_USE_C2X_STRTOL
+#define __GLIBC_USE_C2X_STRTOL 0
 #include <locale.h>
+#include <stdbool.h>
 
 extern unsigned long long int ____strtoull_l_internal (const char *, char **,
-						       int, int, locale_t);
+						       int, int, bool,
+						       locale_t);
 
 #include <strtol_l.c>
diff --git a/stdlib/tst-strtol-binary-c11.c b/stdlib/tst-strtol-binary-c11.c
new file mode 100644
index 0000000..6e58bb2
--- /dev/null
+++ b/stdlib/tst-strtol-binary-c11.c
@@ -0,0 +1,29 @@
+/* Test strtol functions with C2X binary integers (narrow strings,
+   no extensions to C11).
+   Copyright (C) 2022-2023 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/>.  */
+
+#undef _GNU_SOURCE
+
+#define CHAR char
+#define FNPFX strto
+#define L_(C) C
+#define TEST_C2X 0
+#define TEST_Q 0
+#define TEST_LOCALE 0
+
+#include <tst-strtol-binary-main.c>
diff --git a/stdlib/tst-strtol-binary-c2x.c b/stdlib/tst-strtol-binary-c2x.c
new file mode 100644
index 0000000..b9ccfda
--- /dev/null
+++ b/stdlib/tst-strtol-binary-c2x.c
@@ -0,0 +1,32 @@
+/* Test strtol functions with C2X binary integers (narrow strings,
+   no extensions).
+   Copyright (C) 2022-2023 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/>.  */
+
+/* Some versions of GCC supported for building glibc do not support
+   -std=c2x.  */
+#undef _GNU_SOURCE
+#define _ISOC2X_SOURCE
+
+#define CHAR char
+#define FNPFX strto
+#define L_(C) C
+#define TEST_C2X 1
+#define TEST_Q 0
+#define TEST_LOCALE 0
+
+#include <tst-strtol-binary-main.c>
diff --git a/stdlib/tst-strtol-binary-gnu11.c b/stdlib/tst-strtol-binary-gnu11.c
new file mode 100644
index 0000000..a029591
--- /dev/null
+++ b/stdlib/tst-strtol-binary-gnu11.c
@@ -0,0 +1,34 @@
+/* Test strtol functions with C2X binary integers (narrow strings, GNU
+   extensions, C2X strtol features disabled).
+   Copyright (C) 2022-2023 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 <features.h>
+/* This file tests the old versions of GNU extension functions, which
+   are not normally available to new binaries because GNU extensions
+   normally imply C2X strtol features.  */
+#undef __GLIBC_USE_C2X_STRTOL
+#define __GLIBC_USE_C2X_STRTOL 0
+
+#define CHAR char
+#define FNPFX strto
+#define L_(C) C
+#define TEST_C2X 0
+#define TEST_Q 1
+#define TEST_LOCALE 1
+
+#include <tst-strtol-binary-main.c>
diff --git a/stdlib/tst-strtol-binary-gnu2x.c b/stdlib/tst-strtol-binary-gnu2x.c
new file mode 100644
index 0000000..0a7fdd4
--- /dev/null
+++ b/stdlib/tst-strtol-binary-gnu2x.c
@@ -0,0 +1,27 @@
+/* Test strtol functions with C2X binary integers (narrow strings, GNU
+   extensions).
+   Copyright (C) 2022-2023 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/>.  */
+
+#define CHAR char
+#define FNPFX strto
+#define L_(C) C
+#define TEST_C2X 1
+#define TEST_Q 1
+#define TEST_LOCALE 1
+
+#include <tst-strtol-binary-main.c>
diff --git a/stdlib/tst-strtol-binary-main.c b/stdlib/tst-strtol-binary-main.c
new file mode 100644
index 0000000..ece3100
--- /dev/null
+++ b/stdlib/tst-strtol-binary-main.c
@@ -0,0 +1,151 @@
+/* Test strtol functions with C2X binary integers.
+   Copyright (C) 2022-2023 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 <inttypes.h>
+#include <limits.h>
+#include <locale.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <wchar.h>
+
+#include <support/check.h>
+#if TEST_LOCALE
+# include <support/support.h>
+#endif
+
+#define CONCAT_(X, Y) X ## Y
+#define CONCAT(X, Y) CONCAT_ (X, Y)
+#define FNX(FN) CONCAT (FNPFX, FN)
+
+#define CHECK_RES(ARG, RES, EP, EXPECTED)				\
+  do									\
+    {									\
+      if (TEST_C2X)							\
+	{								\
+	  TEST_COMPARE ((RES), EXPECTED);				\
+	  TEST_COMPARE (*(EP), 0);					\
+	}								\
+      else								\
+	{								\
+	  TEST_COMPARE ((RES), 0);					\
+	  TEST_VERIFY ((EP) == ((ARG)[0] == L_('-')			\
+				? (ARG) + 2				\
+				: (ARG) + 1));				\
+	}								\
+    }									\
+  while (0)
+
+static void
+one_check (const CHAR *s, long int expected_l, unsigned long int expected_ul,
+	   long long int expected_ll, unsigned long long int expected_ull)
+{
+  CHAR *ep;
+  long int ret_l;
+  unsigned long int ret_ul;
+  long long int ret_ll;
+  unsigned long long int ret_ull;
+  ret_l = FNX (l) (s, &ep, 0);
+  CHECK_RES (s, ret_l, ep, expected_l);
+  ret_l = FNX (l) (s, &ep, 2);
+  CHECK_RES (s, ret_l, ep, expected_l);
+  ret_ul = FNX (ul) (s, &ep, 0);
+  CHECK_RES (s, ret_ul, ep, expected_ul);
+  ret_ul = FNX (ul) (s, &ep, 2);
+  CHECK_RES (s, ret_ul, ep, expected_ul);
+  ret_ll = FNX (ll) (s, &ep, 0);
+  CHECK_RES (s, ret_ll, ep, expected_ll);
+  ret_ll = FNX (ll) (s, &ep, 2);
+  CHECK_RES (s, ret_ll, ep, expected_ll);
+  ret_ull = FNX (ull) (s, &ep, 0);
+  CHECK_RES (s, ret_ull, ep, expected_ull);
+  ret_ull = FNX (ull) (s, &ep, 2);
+  CHECK_RES (s, ret_ull, ep, expected_ull);
+  ret_ll = FNX (imax) (s, &ep, 0);
+  CHECK_RES (s, ret_ll, ep, expected_ll);
+  ret_ll = FNX (imax) (s, &ep, 2);
+  CHECK_RES (s, ret_ll, ep, expected_ll);
+  ret_ull = FNX (umax) (s, &ep, 0);
+  CHECK_RES (s, ret_ull, ep, expected_ull);
+  ret_ull = FNX (umax) (s, &ep, 2);
+  CHECK_RES (s, ret_ull, ep, expected_ull);
+#if TEST_Q
+  ret_ll = FNX (q) (s, &ep, 0);
+  CHECK_RES (s, ret_ll, ep, expected_ll);
+  ret_ll = FNX (q) (s, &ep, 2);
+  CHECK_RES (s, ret_ll, ep, expected_ll);
+  ret_ull = FNX (uq) (s, &ep, 0);
+  CHECK_RES (s, ret_ull, ep, expected_ull);
+  ret_ull = FNX (uq) (s, &ep, 2);
+  CHECK_RES (s, ret_ull, ep, expected_ull);
+#endif
+#if TEST_LOCALE
+  locale_t loc = xnewlocale (LC_NUMERIC_MASK, "C", (locale_t) 0);
+  ret_l = FNX (l_l) (s, &ep, 0, loc);
+  CHECK_RES (s, ret_l, ep, expected_l);
+  ret_l = FNX (l_l) (s, &ep, 2, loc);
+  CHECK_RES (s, ret_l, ep, expected_l);
+  ret_ul = FNX (ul_l) (s, &ep, 0, loc);
+  CHECK_RES (s, ret_ul, ep, expected_ul);
+  ret_ul = FNX (ul_l) (s, &ep, 2, loc);
+  CHECK_RES (s, ret_ul, ep, expected_ul);
+  ret_ll = FNX (ll_l) (s, &ep, 0, loc);
+  CHECK_RES (s, ret_ll, ep, expected_ll);
+  ret_ll = FNX (ll_l) (s, &ep, 2, loc);
+  CHECK_RES (s, ret_ll, ep, expected_ll);
+  ret_ull = FNX (ull_l) (s, &ep, 0, loc);
+  CHECK_RES (s, ret_ull, ep, expected_ull);
+  ret_ull = FNX (ull_l) (s, &ep, 2, loc);
+  CHECK_RES (s, ret_ull, ep, expected_ull);
+#endif
+}
+
+static int
+do_test (void)
+{
+  one_check (L_("0b101"), 5, 5, 5, 5);
+  one_check (L_("0B101"), 5, 5, 5, 5);
+  one_check (L_("-0b11111"), -31, -31, -31, -31);
+  one_check (L_("-0B11111"), -31, -31, -31, -31);
+  one_check (L_("0b111111111111111111111111111111111"),
+	     LONG_MAX >= 0x1ffffffffLL ? (long int) 0x1ffffffffLL : LONG_MAX,
+	     (ULONG_MAX >= 0x1ffffffffULL
+	      ? (unsigned long int) 0x1ffffffffULL
+	      : ULONG_MAX),
+	     0x1ffffffffLL, 0x1ffffffffULL);
+  one_check (L_("0B111111111111111111111111111111111"),
+	     LONG_MAX >= 0x1ffffffffLL ? (long int) 0x1ffffffffLL : LONG_MAX,
+	     (ULONG_MAX >= 0x1ffffffffULL
+	      ? (unsigned long int) 0x1ffffffffULL
+	      : ULONG_MAX),
+	     0x1ffffffffLL, 0x1ffffffffULL);
+  one_check (L_("-0b111111111111111111111111111111111"),
+	     LONG_MIN <= -0x1ffffffffLL ? (long int) -0x1ffffffffLL : LONG_MIN,
+	     (ULONG_MAX >= 0x1ffffffffULL
+	      ? (unsigned long int) -0x1ffffffffULL
+	      : ULONG_MAX),
+	     -0x1ffffffffLL, -0x1ffffffffULL);
+  one_check (L_("-0B111111111111111111111111111111111"),
+	     LONG_MIN <= -0x1ffffffffLL ? (long int) -0x1ffffffffLL : LONG_MIN,
+	     (ULONG_MAX >= 0x1ffffffffULL
+	      ? (unsigned long int) -0x1ffffffffULL
+	      : ULONG_MAX),
+	     -0x1ffffffffLL, -0x1ffffffffULL);
+  return 0;
+}
+
+#include <support/test-driver.c>