Revert "Attempt to remove deprecated sv_locking/unlocking"

embed.fnc

@@ -3274,7 +3274,10 @@ ARdp	|SV *	|sv_mortalcopy_flags					\
 				|U32 flags
 ARdp	|SV *	|sv_newmortal
 Cdp	|SV *	|sv_newref	|NULLOK SV * const sv
+ADbdp	|void	|sv_nolocking	|NULLOK SV *sv
+
 Adp	|void	|sv_nosharing	|NULLOK SV *sv
+ADbdp	|void	|sv_nounlocking |NULLOK SV *sv
 : Used in pp.c, pp_hot.c, sv.c
 dpx	|SV *	|sv_2num	|NN SV * const sv
 Adm	|bool	|sv_numeq	|NULLOK SV *sv1 			\

embed.h

@@ -923,6 +923,8 @@
 #   endif
 # endif
 # if !defined(NO_MATHOMS)
+#   define sv_nolocking(a)                      Perl_sv_nolocking(aTHX_ a)
+#   define sv_nounlocking(a)                    Perl_sv_nounlocking(aTHX_ a)
 #   define utf8_to_uvchr(a,b)                   Perl_utf8_to_uvchr(aTHX_ a,b)
 #   define utf8_to_uvuni(a,b)                   Perl_utf8_to_uvuni(aTHX_ a,b)
 #   define utf8n_to_uvuni(a,b,c,d)              Perl_utf8n_to_uvuni(aTHX_ a,b,c,d)

intrpvar.h

@@ -936,7 +936,13 @@ PERLVARI(I, lockhook,	share_proc_t, Perl_sv_nosharing)
 GCC_DIAG_IGNORE(-Wdeprecated-declarations)
 MSVC_DIAG_IGNORE(4996)
 
-PERLVARI(I, unlockhook,	share_proc_t, Perl_sv_nosharing)
+#ifdef NO_MATHOMS
+#  define PERL_UNLOCK_HOOK Perl_sv_nosharing
+#else
+/* This reference ensures that the mathoms are linked with perl */
+#  define PERL_UNLOCK_HOOK Perl_sv_nounlocking
+#endif
+PERLVARI(I, unlockhook,	share_proc_t, PERL_UNLOCK_HOOK)
 
 MSVC_DIAG_RESTORE
 GCC_DIAG_RESTORE

mathoms.c

@@ -437,6 +437,51 @@ Perl_do_aexec(pTHX_ SV *really, SV **mark, SV **sp)
 }
 #endif
 
+/*
+=for apidoc_section $SV
+=for apidoc sv_nolocking
+
+Dummy routine which "locks" an SV when there is no locking module present.
+Exists to avoid test for a C<NULL> function pointer and because it could
+potentially warn under some level of strict-ness.
+
+"Superseded" by C<sv_nosharing()>.
+
+=cut
+*/
+
+void
+Perl_sv_nolocking(pTHX_ SV *sv)
+{
+    PERL_UNUSED_CONTEXT;
+    PERL_UNUSED_ARG(sv);
+}
+
+
+/*
+=for apidoc_section $SV
+=for apidoc sv_nounlocking
+
+Dummy routine which "unlocks" an SV when there is no locking module present.
+Exists to avoid test for a C<NULL> function pointer and because it could
+potentially warn under some level of strict-ness.
+
+"Superseded" by C<sv_nosharing()>.
+
+=cut
+
+PERL_UNLOCK_HOOK in intrpvar.h is the macro that refers to this, and guarantees
+that mathoms gets loaded.
+
+*/
+
+void
+Perl_sv_nounlocking(pTHX_ SV *sv)
+{
+    PERL_UNUSED_CONTEXT;
+    PERL_UNUSED_ARG(sv);
+}
+
 void
 Perl_sv_usepvn_mg(pTHX_ SV *sv, char *ptr, STRLEN len)
 {

pod/perldelta.pod

@@ -349,8 +349,7 @@ well.
 
 =item *
 
-Removed the deprecated (since 5.32) functions C<sv_locking()> and
-C<sv_unlocking>.
+XXX
 
 =back