perl_clone_using: do simple assign/copying first

For all the elements of the interpreter that can be cloned by
a simple initialisation (e.g. assign NULL/0/-1), or by a direct
copy from proto, do these first. This means that anything more complex,
that might for example require a malloc, gets done after as much of the
interpreter structure has already been initialised as possible.

This is the beginnings of a fix for [perl #90006].

This commit should have no change in functionality; it's simply moving a
bunch of assign statements to earlier within perl_clone_using().

1 files changed, 244 insertions, 214 deletions

diff --git a/sv.c b/sv.c
index bc0ef20782..f0d7253170 100644
--- a/sv.c
+++ b/sv.c
@@ -12875,6 +12875,250 @@ perl_clone_using(PerlInterpreter *proto_perl, UV flags,
     PL_hash_seed	= proto_perl->Ihash_seed;
     PL_rehash_seed	= proto_perl->Irehash_seed;
 
+    SvANY(&PL_sv_undef)		= NULL;
+    SvREFCNT(&PL_sv_undef)	= (~(U32)0)/2;
+    SvFLAGS(&PL_sv_undef)	= SVf_READONLY|SVt_NULL;
+    SvREFCNT(&PL_sv_no)		= (~(U32)0)/2;
+    SvFLAGS(&PL_sv_no)		= SVp_IOK|SVf_IOK|SVp_NOK|SVf_NOK
+				  |SVp_POK|SVf_POK|SVf_READONLY|SVt_PVNV;
+
+    SvANY(&PL_sv_yes)		= new_XPVNV();
+    SvREFCNT(&PL_sv_yes)	= (~(U32)0)/2;
+    SvFLAGS(&PL_sv_yes)		= SVp_IOK|SVf_IOK|SVp_NOK|SVf_NOK
+				  |SVp_POK|SVf_POK|SVf_READONLY|SVt_PVNV;
+
+    /* dbargs array probably holds garbage */
+    PL_dbargs		= NULL;
+
+    PL_compiling = proto_perl->Icompiling;
+
+#ifdef PERL_DEBUG_READONLY_OPS
+    PL_slabs = NULL;
+    PL_slab_count = 0;
+#endif
+
+    /* pseudo environmental stuff */
+    PL_origargc		= proto_perl->Iorigargc;
+    PL_origargv		= proto_perl->Iorigargv;
+
+    /* Set tainting stuff before PerlIO_debug can possibly get called */
+    PL_tainting		= proto_perl->Itainting;
+    PL_taint_warn	= proto_perl->Itaint_warn;
+
+    PL_minus_c		= proto_perl->Iminus_c;
+
+    PL_localpatches	= proto_perl->Ilocalpatches;
+    PL_splitstr		= proto_perl->Isplitstr;
+    PL_minus_n		= proto_perl->Iminus_n;
+    PL_minus_p		= proto_perl->Iminus_p;
+    PL_minus_l		= proto_perl->Iminus_l;
+    PL_minus_a		= proto_perl->Iminus_a;
+    PL_minus_E		= proto_perl->Iminus_E;
+    PL_minus_F		= proto_perl->Iminus_F;
+    PL_doswitches	= proto_perl->Idoswitches;
+    PL_dowarn		= proto_perl->Idowarn;
+    PL_sawampersand	= proto_perl->Isawampersand;
+    PL_unsafe		= proto_perl->Iunsafe;
+    PL_perldb		= proto_perl->Iperldb;
+    PL_perl_destruct_level = proto_perl->Iperl_destruct_level;
+    PL_exit_flags       = proto_perl->Iexit_flags;
+
+    /* XXX time(&PL_basetime) when asked for? */
+    PL_basetime		= proto_perl->Ibasetime;
+
+    PL_maxsysfd		= proto_perl->Imaxsysfd;
+    PL_statusvalue	= proto_perl->Istatusvalue;
+#ifdef VMS
+    PL_statusvalue_vms	= proto_perl->Istatusvalue_vms;
+#else
+    PL_statusvalue_posix = proto_perl->Istatusvalue_posix;
+#endif
+
+    /* RE engine related */
+    Zero(&PL_reg_state, 1, struct re_save_state);
+    PL_reginterp_cnt	= 0;
+    PL_regmatch_slab	= NULL;
+
+    PL_sub_generation	= proto_perl->Isub_generation;
+
+    /* funky return mechanisms */
+    PL_forkprocess	= proto_perl->Iforkprocess;
+
+    /* internal state */
+    PL_maxo		= proto_perl->Imaxo;
+
+    PL_main_start	= proto_perl->Imain_start;
+    PL_eval_root	= proto_perl->Ieval_root;
+    PL_eval_start	= proto_perl->Ieval_start;
+
+    PL_filemode		= proto_perl->Ifilemode;
+    PL_lastfd		= proto_perl->Ilastfd;
+    PL_oldname		= proto_perl->Ioldname;		/* XXX not quite right */
+    PL_Argv		= NULL;
+    PL_Cmd		= NULL;
+    PL_gensym		= proto_perl->Igensym;
+
+    PL_laststatval	= proto_perl->Ilaststatval;
+    PL_laststype	= proto_perl->Ilaststype;
+    PL_mess_sv		= NULL;
+
+    PL_profiledata	= NULL;
+
+    PL_generation	= proto_perl->Igeneration;
+
+    PL_in_clean_objs	= proto_perl->Iin_clean_objs;
+    PL_in_clean_all	= proto_perl->Iin_clean_all;
+
+    PL_uid		= proto_perl->Iuid;
+    PL_euid		= proto_perl->Ieuid;
+    PL_gid		= proto_perl->Igid;
+    PL_egid		= proto_perl->Iegid;
+    PL_nomemok		= proto_perl->Inomemok;
+    PL_an		= proto_perl->Ian;
+    PL_evalseq		= proto_perl->Ievalseq;
+    PL_origenviron	= proto_perl->Iorigenviron;	/* XXX not quite right */
+    PL_origalen		= proto_perl->Iorigalen;
+
+    PL_sighandlerp	= proto_perl->Isighandlerp;
+
+    PL_runops		= proto_perl->Irunops;
+
+    PL_subline		= proto_perl->Isubline;
+
+#ifdef FCRYPT
+    PL_cryptseen	= proto_perl->Icryptseen;
+#endif
+
+    PL_hints		= proto_perl->Ihints;
+
+    PL_amagic_generation	= proto_perl->Iamagic_generation;
+
+#ifdef USE_LOCALE_COLLATE
+    PL_collation_ix	= proto_perl->Icollation_ix;
+    PL_collation_standard	= proto_perl->Icollation_standard;
+    PL_collxfrm_base	= proto_perl->Icollxfrm_base;
+    PL_collxfrm_mult	= proto_perl->Icollxfrm_mult;
+#endif /* USE_LOCALE_COLLATE */
+
+#ifdef USE_LOCALE_NUMERIC
+    PL_numeric_standard	= proto_perl->Inumeric_standard;
+    PL_numeric_local	= proto_perl->Inumeric_local;
+#endif /* !USE_LOCALE_NUMERIC */
+
+    /* Did the locale setup indicate UTF-8? */
+    PL_utf8locale	= proto_perl->Iutf8locale;
+    /* Unicode features (see perlrun/-C) */
+    PL_unicode		= proto_perl->Iunicode;
+
+    /* Pre-5.8 signals control */
+    PL_signals		= proto_perl->Isignals;
+
+    /* times() ticks per second */
+    PL_clocktick	= proto_perl->Iclocktick;
+
+    /* Recursion stopper for PerlIO_find_layer */
+    PL_in_load_module	= proto_perl->Iin_load_module;
+
+    /* sort() routine */
+    PL_sort_RealCmp	= proto_perl->Isort_RealCmp;
+
+    /* Not really needed/useful since the reenrant_retint is "volatile",
+     * but do it for consistency's sake. */
+    PL_reentrant_retint	= proto_perl->Ireentrant_retint;
+
+    /* Hooks to shared SVs and locks. */
+    PL_sharehook	= proto_perl->Isharehook;
+    PL_lockhook		= proto_perl->Ilockhook;
+    PL_unlockhook	= proto_perl->Iunlockhook;
+    PL_threadhook	= proto_perl->Ithreadhook;
+    PL_destroyhook	= proto_perl->Idestroyhook;
+    PL_signalhook	= proto_perl->Isignalhook;
+
+#ifdef THREADS_HAVE_PIDS
+    PL_ppid		= proto_perl->Ippid;
+#endif
+
+    /* swatch cache */
+    PL_last_swash_hv	= NULL;	/* reinits on demand */
+    PL_last_swash_klen	= 0;
+    PL_last_swash_key[0]= '\0';
+    PL_last_swash_tmps	= (U8*)NULL;
+    PL_last_swash_slen	= 0;
+
+    PL_glob_index	= proto_perl->Iglob_index;
+    PL_srand_called	= proto_perl->Isrand_called;
+
+    if (flags & CLONEf_COPY_STACKS) {
+	/* next allocation will be PL_tmps_stack[PL_tmps_ix+1] */
+	PL_tmps_ix		= proto_perl->Itmps_ix;
+	PL_tmps_max		= proto_perl->Itmps_max;
+	PL_tmps_floor		= proto_perl->Itmps_floor;
+
+	/* next push_scope()/ENTER sets PL_scopestack[PL_scopestack_ix]
+	 * NOTE: unlike the others! */
+	PL_scopestack_ix	= proto_perl->Iscopestack_ix;
+	PL_scopestack_max	= proto_perl->Iscopestack_max;
+
+	/* next SSPUSHFOO() sets PL_savestack[PL_savestack_ix]
+	 * NOTE: unlike the others! */
+	PL_savestack_ix		= proto_perl->Isavestack_ix;
+	PL_savestack_max	= proto_perl->Isavestack_max;
+    }
+
+    PL_start_env	= proto_perl->Istart_env;	/* XXXXXX */
+    PL_top_env		= &PL_start_env;
+
+    PL_op		= proto_perl->Iop;
+
+    PL_Sv		= NULL;
+    PL_Xpv		= (XPV*)NULL;
+    my_perl->Ina	= proto_perl->Ina;
+
+    PL_statbuf		= proto_perl->Istatbuf;
+    PL_statcache	= proto_perl->Istatcache;
+
+#ifdef HAS_TIMES
+    PL_timesbuf		= proto_perl->Itimesbuf;
+#endif
+
+    PL_tainted		= proto_perl->Itainted;
+    PL_curpm		= proto_perl->Icurpm;	/* XXX No PMOP ref count */
+
+    PL_chopset		= proto_perl->Ichopset;	/* XXX never deallocated */
+
+    PL_restartjmpenv	= proto_perl->Irestartjmpenv;
+    PL_restartop	= proto_perl->Irestartop;
+    PL_in_eval		= proto_perl->Iin_eval;
+    PL_delaymagic	= proto_perl->Idelaymagic;
+    PL_phase		= proto_perl->Iphase;
+    PL_localizing	= proto_perl->Ilocalizing;
+
+    PL_hv_fetch_ent_mh	= NULL;
+    PL_modcount		= proto_perl->Imodcount;
+    PL_lastgotoprobe	= NULL;
+    PL_dumpindent	= proto_perl->Idumpindent;
+
+    PL_efloatbuf	= NULL;		/* reinits on demand */
+    PL_efloatsize	= 0;			/* reinits on demand */
+
+    /* regex stuff */
+
+    PL_screamfirst	= NULL;
+    PL_screamnext	= NULL;
+    PL_maxscream	= -1;			/* reinits on demand */
+    PL_lastscream	= NULL;
+
+
+    PL_regdummy		= proto_perl->Iregdummy;
+    PL_colorset		= 0;		/* reinits PL_colors[] */
+    /*PL_colors[6]	= {0,0,0,0,0,0};*/
+
+    /* Pluggable optimizer */
+    PL_peepp		= proto_perl->Ipeepp;
+    PL_rpeepp		= proto_perl->Irpeepp;
+    /* op_free() hook */
+    PL_opfreehook	= proto_perl->Iopfreehook;
+
 #ifdef USE_REENTRANT_API
     /* XXX: things like -Dm will segfault here in perlio, but doing
      *  PERL_SET_CONTEXT(proto_perl);
@@ -12887,15 +13131,9 @@ perl_clone_using(PerlInterpreter *proto_perl, UV flags,
     PL_ptr_table = ptr_table_new();
 
     /* initialize these special pointers as early as possible */
-    SvANY(&PL_sv_undef)		= NULL;
-    SvREFCNT(&PL_sv_undef)	= (~(U32)0)/2;
-    SvFLAGS(&PL_sv_undef)	= SVf_READONLY|SVt_NULL;
     ptr_table_store(PL_ptr_table, &proto_perl->Isv_undef, &PL_sv_undef);
 
     SvANY(&PL_sv_no)		= new_XPVNV();
-    SvREFCNT(&PL_sv_no)		= (~(U32)0)/2;
-    SvFLAGS(&PL_sv_no)		= SVp_IOK|SVf_IOK|SVp_NOK|SVf_NOK
-				  |SVp_POK|SVf_POK|SVf_READONLY|SVt_PVNV;
     SvPV_set(&PL_sv_no, savepvn(PL_No, 0));
     SvCUR_set(&PL_sv_no, 0);
     SvLEN_set(&PL_sv_no, 1);
@@ -12903,10 +13141,6 @@ perl_clone_using(PerlInterpreter *proto_perl, UV flags,
     SvNV_set(&PL_sv_no, 0);
     ptr_table_store(PL_ptr_table, &proto_perl->Isv_no, &PL_sv_no);
 
-    SvANY(&PL_sv_yes)		= new_XPVNV();
-    SvREFCNT(&PL_sv_yes)	= (~(U32)0)/2;
-    SvFLAGS(&PL_sv_yes)		= SVp_IOK|SVf_IOK|SVp_NOK|SVf_NOK
-				  |SVp_POK|SVf_POK|SVf_READONLY|SVt_PVNV;
     SvPV_set(&PL_sv_yes, savepvn(PL_Yes, 1));
     SvCUR_set(&PL_sv_yes, 1);
     SvLEN_set(&PL_sv_yes, 2);
@@ -12914,17 +13148,12 @@ perl_clone_using(PerlInterpreter *proto_perl, UV flags,
     SvNV_set(&PL_sv_yes, 1);
     ptr_table_store(PL_ptr_table, &proto_perl->Isv_yes, &PL_sv_yes);
 
-    /* dbargs array probably holds garbage */
-    PL_dbargs		= NULL;
-
     /* create (a non-shared!) shared string table */
     PL_strtab		= newHV();
     HvSHAREKEYS_off(PL_strtab);
     hv_ksplit(PL_strtab, HvTOTALKEYS(proto_perl->Istrtab));
     ptr_table_store(PL_ptr_table, proto_perl->Istrtab, PL_strtab);
 
-    PL_compiling = proto_perl->Icompiling;
-
     /* These two PVs will be free'd special way so must set them same way op.c does */
     PL_compiling.cop_stashpv = savesharedpv(PL_compiling.cop_stashpv);
     ptr_table_store(PL_ptr_table, proto_perl->Icompiling.cop_stashpv, PL_compiling.cop_stashpv);
@@ -12936,14 +13165,6 @@ perl_clone_using(PerlInterpreter *proto_perl, UV flags,
     PL_compiling.cop_warnings = DUP_WARNINGS(PL_compiling.cop_warnings);
     CopHINTHASH_set(&PL_compiling, cophh_copy(CopHINTHASH_get(&PL_compiling)));
     PL_curcop		= (COP*)any_dup(proto_perl->Icurcop, proto_perl);
-#ifdef PERL_DEBUG_READONLY_OPS
-    PL_slabs = NULL;
-    PL_slab_count = 0;
-#endif
-
-    /* pseudo environmental stuff */
-    PL_origargc		= proto_perl->Iorigargc;
-    PL_origargv		= proto_perl->Iorigargv;
 
     param->stashes      = newAV();  /* Setup array of objects to call clone on */
     /* This makes no difference to the implementation, as it always pushes
@@ -12958,10 +13179,6 @@ perl_clone_using(PerlInterpreter *proto_perl, UV flags,
 	param->unreferenced = newAV();
     }
 
-    /* Set tainting stuff before PerlIO_debug can possibly get called */
-    PL_tainting		= proto_perl->Itainting;
-    PL_taint_warn	= proto_perl->Itaint_warn;
-
 #ifdef PERLIO_LAYERS
     /* Clone PerlIO tables as soon as we can handle general xx_dup() */
     PerlIO_clone(aTHX_ proto_perl, param);
@@ -12975,39 +13192,14 @@ perl_clone_using(PerlInterpreter *proto_perl, UV flags,
     PL_warnhook		= sv_dup_inc(proto_perl->Iwarnhook, param);
 
     /* switches */
-    PL_minus_c		= proto_perl->Iminus_c;
     PL_patchlevel	= sv_dup_inc(proto_perl->Ipatchlevel, param);
     PL_apiversion	= sv_dup_inc(proto_perl->Iapiversion, param);
-    PL_localpatches	= proto_perl->Ilocalpatches;
-    PL_splitstr		= proto_perl->Isplitstr;
-    PL_minus_n		= proto_perl->Iminus_n;
-    PL_minus_p		= proto_perl->Iminus_p;
-    PL_minus_l		= proto_perl->Iminus_l;
-    PL_minus_a		= proto_perl->Iminus_a;
-    PL_minus_E		= proto_perl->Iminus_E;
-    PL_minus_F		= proto_perl->Iminus_F;
-    PL_doswitches	= proto_perl->Idoswitches;
-    PL_dowarn		= proto_perl->Idowarn;
-    PL_sawampersand	= proto_perl->Isawampersand;
-    PL_unsafe		= proto_perl->Iunsafe;
     PL_inplace		= SAVEPV(proto_perl->Iinplace);
     PL_e_script		= sv_dup_inc(proto_perl->Ie_script, param);
-    PL_perldb		= proto_perl->Iperldb;
-    PL_perl_destruct_level = proto_perl->Iperl_destruct_level;
-    PL_exit_flags       = proto_perl->Iexit_flags;
 
     /* magical thingies */
-    /* XXX time(&PL_basetime) when asked for? */
-    PL_basetime		= proto_perl->Ibasetime;
     PL_formfeed		= sv_dup(proto_perl->Iformfeed, param);
 
-    PL_maxsysfd		= proto_perl->Imaxsysfd;
-    PL_statusvalue	= proto_perl->Istatusvalue;
-#ifdef VMS
-    PL_statusvalue_vms	= proto_perl->Istatusvalue_vms;
-#else
-    PL_statusvalue_posix = proto_perl->Istatusvalue_posix;
-#endif
     PL_encoding		= sv_dup(proto_perl->Iencoding, param);
 
     sv_setpvs(PERL_DEBUG_PAD(0), "");	/* For regex debugging. */
@@ -13015,11 +13207,6 @@ perl_clone_using(PerlInterpreter *proto_perl, UV flags,
     sv_setpvs(PERL_DEBUG_PAD(2), "");	/* even without DEBUGGING. */
 
    
-    /* RE engine related */
-    Zero(&PL_reg_state, 1, struct re_save_state);
-    PL_reginterp_cnt	= 0;
-    PL_regmatch_slab	= NULL;
-    
     /* Clone the regex array */
     /* ORANGE FIXME for plugins, probably in the SV dup code.
        newSViv(PTR2IV(CALLREGDUPE(
@@ -13067,17 +13254,11 @@ perl_clone_using(PerlInterpreter *proto_perl, UV flags,
     PL_checkav		= av_dup_inc(proto_perl->Icheckav, param);
     PL_initav		= av_dup_inc(proto_perl->Iinitav, param);
 
-    PL_sub_generation	= proto_perl->Isub_generation;
     PL_isarev		= hv_dup_inc(proto_perl->Iisarev, param);
 
-    /* funky return mechanisms */
-    PL_forkprocess	= proto_perl->Iforkprocess;
-
     /* subprocess state */
     PL_fdpid		= av_dup_inc(proto_perl->Ifdpid, param);
 
-    /* internal state */
-    PL_maxo		= proto_perl->Imaxo;
     if (proto_perl->Iop_mask)
 	PL_op_mask	= SAVEPVN(proto_perl->Iop_mask, PL_maxo);
     else
@@ -13089,23 +13270,11 @@ perl_clone_using(PerlInterpreter *proto_perl, UV flags,
     OP_REFCNT_LOCK;
     PL_main_root	= OpREFCNT_inc(proto_perl->Imain_root);
     OP_REFCNT_UNLOCK;
-    PL_main_start	= proto_perl->Imain_start;
-    PL_eval_root	= proto_perl->Ieval_root;
-    PL_eval_start	= proto_perl->Ieval_start;
 
     /* runtime control stuff */
     PL_curcopdb		= (COP*)any_dup(proto_perl->Icurcopdb, proto_perl);
 
-    PL_filemode		= proto_perl->Ifilemode;
-    PL_lastfd		= proto_perl->Ilastfd;
-    PL_oldname		= proto_perl->Ioldname;		/* XXX not quite right */
-    PL_Argv		= NULL;
-    PL_Cmd		= NULL;
-    PL_gensym		= proto_perl->Igensym;
     PL_preambleav	= av_dup_inc(proto_perl->Ipreambleav, param);
-    PL_laststatval	= proto_perl->Ilaststatval;
-    PL_laststype	= proto_perl->Ilaststype;
-    PL_mess_sv		= NULL;
 
     PL_ors_sv		= sv_dup_inc(proto_perl->Iors_sv, param);
 
@@ -13138,8 +13307,6 @@ perl_clone_using(PerlInterpreter *proto_perl, UV flags,
     PL_custom_op_descs  = hv_dup_inc(proto_perl->Icustom_op_descs,param);
     PL_custom_ops	= hv_dup_inc(proto_perl->Icustom_ops, param);
 
-    PL_profiledata	= NULL;
-
     PL_compcv			= cv_dup(proto_perl->Icompcv, param);
 
     PAD_CLONE_VARS(proto_perl, param);
@@ -13148,30 +13315,12 @@ perl_clone_using(PerlInterpreter *proto_perl, UV flags,
     sys_intern_dup(&proto_perl->Isys_intern, &PL_sys_intern);
 #endif
 
-    /* more statics moved here */
-    PL_generation	= proto_perl->Igeneration;
     PL_DBcv		= cv_dup(proto_perl->IDBcv, param);
 
-    PL_in_clean_objs	= proto_perl->Iin_clean_objs;
-    PL_in_clean_all	= proto_perl->Iin_clean_all;
-
-    PL_uid		= proto_perl->Iuid;
-    PL_euid		= proto_perl->Ieuid;
-    PL_gid		= proto_perl->Igid;
-    PL_egid		= proto_perl->Iegid;
-    PL_nomemok		= proto_perl->Inomemok;
-    PL_an		= proto_perl->Ian;
-    PL_evalseq		= proto_perl->Ievalseq;
-    PL_origenviron	= proto_perl->Iorigenviron;	/* XXX not quite right */
-    PL_origalen		= proto_perl->Iorigalen;
 #ifdef PERL_USES_PL_PIDSTATUS
     PL_pidstatus	= newHV();			/* XXX flag for cloning? */
 #endif
     PL_osname		= SAVEPV(proto_perl->Iosname);
-    PL_sighandlerp	= proto_perl->Isighandlerp;
-
-    PL_runops		= proto_perl->Irunops;
-
     PL_parser		= parser_dup(proto_perl->Iparser, param);
 
     /* XXX this only works if the saved cop has already been cloned */
@@ -13181,29 +13330,14 @@ perl_clone_using(PerlInterpreter *proto_perl, UV flags,
 				    proto_perl);
     }
 
-    PL_subline		= proto_perl->Isubline;
     PL_subname		= sv_dup_inc(proto_perl->Isubname, param);
 
-#ifdef FCRYPT
-    PL_cryptseen	= proto_perl->Icryptseen;
-#endif
-
-    PL_hints		= proto_perl->Ihints;
-
-    PL_amagic_generation	= proto_perl->Iamagic_generation;
-
 #ifdef USE_LOCALE_COLLATE
-    PL_collation_ix	= proto_perl->Icollation_ix;
     PL_collation_name	= SAVEPV(proto_perl->Icollation_name);
-    PL_collation_standard	= proto_perl->Icollation_standard;
-    PL_collxfrm_base	= proto_perl->Icollxfrm_base;
-    PL_collxfrm_mult	= proto_perl->Icollxfrm_mult;
 #endif /* USE_LOCALE_COLLATE */
 
 #ifdef USE_LOCALE_NUMERIC
     PL_numeric_name	= SAVEPV(proto_perl->Inumeric_name);
-    PL_numeric_standard	= proto_perl->Inumeric_standard;
-    PL_numeric_local	= proto_perl->Inumeric_local;
     PL_numeric_radix_sv	= sv_dup_inc(proto_perl->Inumeric_radix_sv, param);
 #endif /* !USE_LOCALE_NUMERIC */
 
@@ -13241,48 +13375,6 @@ perl_clone_using(PerlInterpreter *proto_perl, UV flags,
     PL_utf8_xidcont	= sv_dup_inc(proto_perl->Iutf8_xidcont, param);
     PL_utf8_foldable	= hv_dup_inc(proto_perl->Iutf8_foldable, param);
 
-    /* Did the locale setup indicate UTF-8? */
-    PL_utf8locale	= proto_perl->Iutf8locale;
-    /* Unicode features (see perlrun/-C) */
-    PL_unicode		= proto_perl->Iunicode;
-
-    /* Pre-5.8 signals control */
-    PL_signals		= proto_perl->Isignals;
-
-    /* times() ticks per second */
-    PL_clocktick	= proto_perl->Iclocktick;
-
-    /* Recursion stopper for PerlIO_find_layer */
-    PL_in_load_module	= proto_perl->Iin_load_module;
-
-    /* sort() routine */
-    PL_sort_RealCmp	= proto_perl->Isort_RealCmp;
-
-    /* Not really needed/useful since the reenrant_retint is "volatile",
-     * but do it for consistency's sake. */
-    PL_reentrant_retint	= proto_perl->Ireentrant_retint;
-
-    /* Hooks to shared SVs and locks. */
-    PL_sharehook	= proto_perl->Isharehook;
-    PL_lockhook		= proto_perl->Ilockhook;
-    PL_unlockhook	= proto_perl->Iunlockhook;
-    PL_threadhook	= proto_perl->Ithreadhook;
-    PL_destroyhook	= proto_perl->Idestroyhook;
-    PL_signalhook	= proto_perl->Isignalhook;
-
-#ifdef THREADS_HAVE_PIDS
-    PL_ppid		= proto_perl->Ippid;
-#endif
-
-    /* swatch cache */
-    PL_last_swash_hv	= NULL;	/* reinits on demand */
-    PL_last_swash_klen	= 0;
-    PL_last_swash_key[0]= '\0';
-    PL_last_swash_tmps	= (U8*)NULL;
-    PL_last_swash_slen	= 0;
-
-    PL_glob_index	= proto_perl->Iglob_index;
-    PL_srand_called	= proto_perl->Isrand_called;
 
     if (proto_perl->Ipsig_pend) {
 	Newxz(PL_psig_pend, SIG_SIZE, int);
@@ -13302,13 +13394,7 @@ perl_clone_using(PerlInterpreter *proto_perl, UV flags,
 	PL_psig_name	= (SV**)NULL;
     }
 
-    /* intrpvar.h stuff */
-
     if (flags & CLONEf_COPY_STACKS) {
-	/* next allocation will be PL_tmps_stack[PL_tmps_ix+1] */
-	PL_tmps_ix		= proto_perl->Itmps_ix;
-	PL_tmps_max		= proto_perl->Itmps_max;
-	PL_tmps_floor		= proto_perl->Itmps_floor;
 	Newx(PL_tmps_stack, PL_tmps_max, SV*);
 	sv_dup_inc_multiple(proto_perl->Itmps_stack, PL_tmps_stack,
 			    PL_tmps_ix+1, param);
@@ -13325,8 +13411,6 @@ perl_clone_using(PerlInterpreter *proto_perl, UV flags,
 
 	/* next push_scope()/ENTER sets PL_scopestack[PL_scopestack_ix]
 	 * NOTE: unlike the others! */
-	PL_scopestack_ix	= proto_perl->Iscopestack_ix;
-	PL_scopestack_max	= proto_perl->Iscopestack_max;
 	Newxz(PL_scopestack, PL_scopestack_max, I32);
 	Copy(proto_perl->Iscopestack, PL_scopestack, PL_scopestack_ix, I32);
 
@@ -13347,10 +13431,6 @@ perl_clone_using(PerlInterpreter *proto_perl, UV flags,
 						   - proto_perl->Istack_base);
 	PL_stack_max		= PL_stack_base + AvMAX(PL_curstack);
 
-	/* next SSPUSHFOO() sets PL_savestack[PL_savestack_ix]
-	 * NOTE: unlike the others! */
-	PL_savestack_ix		= proto_perl->Isavestack_ix;
-	PL_savestack_max	= proto_perl->Isavestack_max;
 	/*Newxz(PL_savestack, PL_savestack_max, ANY);*/
 	PL_savestack		= ss_dup(proto_perl, param);
     }
@@ -13359,72 +13439,22 @@ perl_clone_using(PerlInterpreter *proto_perl, UV flags,
 	ENTER;			/* perl_destruct() wants to LEAVE; */
     }
 
-    PL_start_env	= proto_perl->Istart_env;	/* XXXXXX */
-    PL_top_env		= &PL_start_env;
-
-    PL_op		= proto_perl->Iop;
-
-    PL_Sv		= NULL;
-    PL_Xpv		= (XPV*)NULL;
-    my_perl->Ina	= proto_perl->Ina;
-
-    PL_statbuf		= proto_perl->Istatbuf;
-    PL_statcache	= proto_perl->Istatcache;
     PL_statgv		= gv_dup(proto_perl->Istatgv, param);
     PL_statname		= sv_dup_inc(proto_perl->Istatname, param);
-#ifdef HAS_TIMES
-    PL_timesbuf		= proto_perl->Itimesbuf;
-#endif
 
-    PL_tainted		= proto_perl->Itainted;
-    PL_curpm		= proto_perl->Icurpm;	/* XXX No PMOP ref count */
     PL_rs		= sv_dup_inc(proto_perl->Irs, param);
     PL_last_in_gv	= gv_dup(proto_perl->Ilast_in_gv, param);
     PL_defoutgv		= gv_dup_inc(proto_perl->Idefoutgv, param);
-    PL_chopset		= proto_perl->Ichopset;	/* XXX never deallocated */
     PL_toptarget	= sv_dup_inc(proto_perl->Itoptarget, param);
     PL_bodytarget	= sv_dup_inc(proto_perl->Ibodytarget, param);
     PL_formtarget	= sv_dup(proto_perl->Iformtarget, param);
 
-    PL_restartjmpenv	= proto_perl->Irestartjmpenv;
-    PL_restartop	= proto_perl->Irestartop;
-    PL_in_eval		= proto_perl->Iin_eval;
-    PL_delaymagic	= proto_perl->Idelaymagic;
-    PL_phase		= proto_perl->Iphase;
-    PL_localizing	= proto_perl->Ilocalizing;
-
     PL_errors		= sv_dup_inc(proto_perl->Ierrors, param);
-    PL_hv_fetch_ent_mh	= NULL;
-    PL_modcount		= proto_perl->Imodcount;
-    PL_lastgotoprobe	= NULL;
-    PL_dumpindent	= proto_perl->Idumpindent;
 
     PL_sortcop		= (OP*)any_dup(proto_perl->Isortcop, proto_perl);
     PL_sortstash	= hv_dup(proto_perl->Isortstash, param);
     PL_firstgv		= gv_dup(proto_perl->Ifirstgv, param);
     PL_secondgv		= gv_dup(proto_perl->Isecondgv, param);
-    PL_efloatbuf	= NULL;		/* reinits on demand */
-    PL_efloatsize	= 0;			/* reinits on demand */
-
-    /* regex stuff */
-
-    PL_screamfirst	= NULL;
-    PL_screamnext	= NULL;
-    PL_maxscream	= -1;			/* reinits on demand */
-    PL_lastscream	= NULL;
-
-
-    PL_regdummy		= proto_perl->Iregdummy;
-    PL_colorset		= 0;		/* reinits PL_colors[] */
-    /*PL_colors[6]	= {0,0,0,0,0,0};*/
-
-
-
-    /* Pluggable optimizer */
-    PL_peepp		= proto_perl->Ipeepp;
-    PL_rpeepp		= proto_perl->Irpeepp;
-    /* op_free() hook */
-    PL_opfreehook	= proto_perl->Iopfreehook;
 
     PL_stashcache       = newHV();