From 3677d5e89092315cde08056bfdf4e006224ea0aa Mon Sep 17 00:00:00 2001
From: Lukas Mai <lukasmai.403@gmail.com>
Date: Sat, 16 Aug 2025 14:52:37 +0200
Subject: [PATCH] fix type of Perl_magic_getarylen

This function is used as part of PL_magic_vtables, so its type must be
'int (pTHX_ SV *, MAGIC *)' exactly (no const). With the right type, we
no longer need an ad-hoc cast in mg_vtables.h, which means we no longer
need the 'const' code in regen/mg_vtable.pl, which was a special case
used by this one function only.

Should fix ASan complaints about functions being called with incorrect
types.
---
 embed.fnc          | 2 +-
 mg.c               | 2 +-
 mg_vtable.h        | 2 +-
 proto.h            | 2 +-
 regen/mg_vtable.pl | 8 +-------
 5 files changed, 5 insertions(+), 11 deletions(-)

diff --git a/embed.fnc b/embed.fnc
index c58deae6a8..6f5ea96931 100644
--- a/embed.fnc
+++ b/embed.fnc
@@ -1909,7 +1909,7 @@ p	|int	|magic_freeutf8 |NN SV *sv				\
 p	|int	|magic_get	|NN SV *sv				\
 				|NN MAGIC *mg
 p	|int	|magic_getarylen|NN SV *sv				\
-				|NN const MAGIC *mg
+				|NN MAGIC *mg
 p	|int	|magic_getdebugvar					\
 				|NN SV *sv				\
 				|NN MAGIC *mg
diff --git a/mg.c b/mg.c
index c876c17269..7a30f63c30 100644
--- a/mg.c
+++ b/mg.c
@@ -2364,7 +2364,7 @@ Perl_magic_setdbline(pTHX_ SV *sv, MAGIC *mg)
 }
 
 int
-Perl_magic_getarylen(pTHX_ SV *sv, const MAGIC *mg)
+Perl_magic_getarylen(pTHX_ SV *sv, MAGIC *mg)
 {
     AV * const obj = MUTABLE_AV(mg->mg_obj);
 
diff --git a/mg_vtable.h b/mg_vtable.h
index 7d46f671e7..46a56f50f4 100644
--- a/mg_vtable.h
+++ b/mg_vtable.h
@@ -165,7 +165,7 @@ EXTCONST char * const PL_magic_vtable_names[magic_vtable_max];
 
 #ifdef DOINIT
 EXT_MGVTBL PL_magic_vtables[magic_vtable_max] = {
-  { (int (*)(pTHX_ SV *, MAGIC *))Perl_magic_getarylen, Perl_magic_setarylen, 0, 0, 0, 0, 0, 0 },
+  { Perl_magic_getarylen, Perl_magic_setarylen, 0, 0, 0, 0, 0, 0 },
   { 0, 0, 0, Perl_magic_cleararylen_p, Perl_magic_freearylen_p, 0, 0, 0 },
   { 0, 0, 0, 0, Perl_magic_killbackrefs, 0, 0, 0 },
   { 0, 0, 0, 0, 0, Perl_magic_copycallchecker, 0, 0 },
diff --git a/proto.h b/proto.h
index 34d897217a..a8a106ddbb 100644
--- a/proto.h
+++ b/proto.h
@@ -2207,7 +2207,7 @@ Perl_magic_get(pTHX_ SV *sv, MAGIC *mg)
         assert(sv); assert(mg)
 
 PERL_CALLCONV int
-Perl_magic_getarylen(pTHX_ SV *sv, const MAGIC *mg)
+Perl_magic_getarylen(pTHX_ SV *sv, MAGIC *mg)
         __attribute__visibility__("hidden");
 #define PERL_ARGS_ASSERT_MAGIC_GETARYLEN        \
         assert(sv); assert(mg)
diff --git a/regen/mg_vtable.pl b/regen/mg_vtable.pl
index a80075cd8c..e113464eac 100644
--- a/regen/mg_vtable.pl
+++ b/regen/mg_vtable.pl
@@ -245,11 +245,6 @@ my %mg =
 #       prefix the vtable with the specified entry (e.g. '#ifdef FOO')
 #       and suffix it with '#else { 0, 0, 0, 0, 0, 0, 0, 0 } #endif'
 #
-#    const
-#       special-case cast a 'get' function whose signature expects
-#       a pointer to constant magic, so that it can be added to a vtable
-#       which expects pointers to functions without the 'const'.
-#
 #    get
 #    set
 #    len
@@ -277,7 +272,7 @@ my %vtable_conf =
      'dbline' => {set => 'setdbline'},
      'isa' => {set => 'setisa', clear => 'clearisa'},
      'isaelem' => {set => 'setisa'},
-     'arylen' => {get => 'getarylen', set => 'setarylen', const => 1},
+     'arylen' => {get => 'getarylen', set => 'setarylen'},
      'arylen_p' => {clear => 'cleararylen_p', free => 'freearylen_p'},
      'mglob'    => {set   => 'setmglob',
                     free  => 'freemglob' },
@@ -528,7 +523,6 @@ while (my $name = shift @names) {
         $data->{$_} ? "Perl_magic_$data->{$_}" : 0;
     } qw(get set len clear free copy dup local);
 
-    $funcs[0] = "(int (*)(pTHX_ SV *, MAGIC *))" . $funcs[0] if $data->{const};
     my $funcs = join ", ", @funcs;
 
     # Because we can't have a , after the last {...}