X-Git-Url: https://perl5.git.perl.org/perl5.git/blobdiff_plain/f07626add3eda6dfda7c5f6fe05cbe1c9293ccd2..df70e763aeb1c1a87b080f81716c3769cc156280:/pp_ctl.c?ds=sidebyside

diff --git a/pp_ctl.c b/pp_ctl.c
index b8c0842..f8190e3 100644
--- a/pp_ctl.c
+++ b/pp_ctl.c
@@ -83,7 +83,7 @@ PP(pp_regcomp)
     REGEXP *re = NULL;
     REGEXP *new_re;
     const regexp_engine *eng;
-    bool is_bare_re;
+    bool is_bare_re= FALSE;
 
     if (PL_op->op_flags & OPf_STACKED) {
 	dMARK;
@@ -107,16 +107,29 @@ PP(pp_regcomp)
     assert (re != (REGEXP*) &PL_sv_undef);
     eng = re ? RX_ENGINE(re) : current_re_engine();
 
+    /*
+     In the below logic: these are basically the same - check if this regcomp is part of a split.
+
+    (PL_op->op_pmflags & PMf_split )
+    (PL_op->op_next->op_type == OP_PUSHRE)
+
+    We could add a new mask for this and copy the PMf_split, if we did
+    some bit definition fiddling first.
+
+    For now we leave this
+    */
+
     new_re = (eng->op_comp
 		    ? eng->op_comp
 		    : &Perl_re_op_compile
 	    )(aTHX_ args, nargs, pm->op_code_list, eng, re,
 		&is_bare_re,
-		(pm->op_pmflags & RXf_PMf_COMPILETIME),
+                (pm->op_pmflags & RXf_PMf_FLAGCOPYMASK),
 		pm->op_pmflags |
 		    (PL_op->op_flags & OPf_SPECIAL ? PMf_USE_RE_EVAL : 0));
+
     if (pm->op_pmflags & PMf_HAS_CV)
-	((struct regexp *)SvANY(new_re))->qr_anoncv
+	ReANY(new_re)->qr_anoncv
 			= (CV*) SvREFCNT_inc(PAD_SV(PL_op->op_targ));
 
     if (is_bare_re) {
@@ -129,7 +142,7 @@ PP(pp_regcomp)
 	   some day. */
 	if (pm->op_type == OP_MATCH) {
 	    SV *lhs;
-	    const bool was_tainted = PL_tainted;
+	    const bool was_tainted = TAINT_get;
 	    if (pm->op_flags & OPf_STACKED)
 		lhs = args[-1];
 	    else if (pm->op_private & OPpTARGET_MY)
@@ -138,22 +151,27 @@ PP(pp_regcomp)
 	    SvGETMAGIC(lhs);
 	    /* Restore the previous value of PL_tainted (which may have been
 	       modified by get-magic), to avoid incorrectly setting the
-	       RXf_TAINTED flag further down. */
-	    PL_tainted = was_tainted;
+	       RXf_TAINTED flag with RX_TAINT_on further down. */
+	    TAINT_set(was_tainted);
+#if NO_TAINT_SUPPORT
+            PERL_UNUSED_VAR(was_tainted);
+#endif
 	}
 	tmp = reg_temp_copy(NULL, new_re);
 	ReREFCNT_dec(new_re);
 	new_re = tmp;
     }
+
     if (re != new_re) {
 	ReREFCNT_dec(re);
 	PM_SETRE(pm, new_re);
     }
 
+
 #ifndef INCOMPLETE_TAINTS
-    if (PL_tainting && PL_tainted) {
+    if (TAINTING_get && TAINT_get) {
 	SvTAINTED_on((SV*)new_re);
-	RX_EXTFLAGS(new_re) |= RXf_TAINTED;
+        RX_TAINT_on(new_re);
     }
 #endif
 
@@ -196,7 +214,6 @@ PP(pp_substcont)
     }
 
     rxres_restore(&cx->sb_rxres, rx);
-    RX_MATCH_UTF8_set(rx, DO_UTF8(cx->sb_targ));
 
     if (cx->sb_iters++) {
 	const I32 saviters = cx->sb_iters;
@@ -209,14 +226,10 @@ PP(pp_substcont)
 	if (SvTAINTED(TOPs))
 	    cx->sb_rxtainted |= SUBST_TAINT_REPL;
 	sv_catsv_nomg(dstr, POPs);
-	/* XXX: adjust for positive offsets of \G for instance s/(.)\G//g with positive pos() */
-	s -= RX_GOFS(rx);
-
-	/* Are we done */
 	if (CxONCE(cx) || s < orig ||
-		!CALLREGEXEC(rx, s, cx->sb_strend, orig,
-			     (s == m) + RX_GOFS(rx), cx->sb_targ, NULL,
-                                (REXEC_IGNOREPOS|REXEC_NOT_FIRST)))
+                !CALLREGEXEC(rx, s, cx->sb_strend, orig,
+			     (s == m), cx->sb_targ, NULL,
+                    (REXEC_IGNOREPOS|REXEC_NOT_FIRST|REXEC_FAIL_ON_UNDERFLOW)))
 	{
 	    SV *targ = cx->sb_targ;
 
@@ -237,12 +250,9 @@ PP(pp_substcont)
 		targ = dstr;
 	    }
 	    else {
-		if (SvIsCOW(targ)) {
-		    sv_force_normal_flags(targ, SV_COW_DROP_PV);
-		} else
-		{
-		    SvPV_free(targ);
-		}
+		SV_CHECK_THINKFIRST_COW_DROP(targ);
+		if (isGV(targ)) Perl_croak_no_modify();
+		SvPV_free(targ);
 		SvPV_set(targ, SvPVX(dstr));
 		SvCUR_set(targ, SvCUR(dstr));
 		SvLEN_set(targ, SvLEN(dstr));
@@ -250,6 +260,7 @@ PP(pp_substcont)
 		    SvUTF8_on(targ);
 		SvPV_set(dstr, NULL);
 
+		PL_tainted = 0;
 		mPUSHi(saviters - 1);
 
 		(void)SvPOK_only_UTF8(targ);
@@ -258,7 +269,7 @@ PP(pp_substcont)
 	    /* update the taint state of various various variables in
 	     * preparation for final exit.
 	     * See "how taint works" above pp_subst() */
-	    if (PL_tainting) {
+	    if (TAINTING_get) {
 		if ((cx->sb_rxtainted & SUBST_TAINT_PAT) ||
 		    ((cx->sb_rxtainted & (SUBST_TAINT_STR|SUBST_TAINT_RETAINT))
 				    == (SUBST_TAINT_STR|SUBST_TAINT_RETAINT))
@@ -270,8 +281,10 @@ PP(pp_substcont)
 		)
 		    SvTAINTED_on(TOPs);  /* taint return value */
 		/* needed for mg_set below */
-		PL_tainted = cBOOL(cx->sb_rxtainted &
-			    (SUBST_TAINT_STR|SUBST_TAINT_PAT|SUBST_TAINT_REPL));
+		TAINT_set(
+                    cBOOL(cx->sb_rxtainted &
+			  (SUBST_TAINT_STR|SUBST_TAINT_PAT|SUBST_TAINT_REPL))
+                );
 		SvTAINT(TARG);
 	    }
 	    /* PL_tainted must be correctly set for this mg_set */
@@ -279,6 +292,7 @@ PP(pp_substcont)
 	    TAINT_NOT;
 	    LEAVE_SCOPE(cx->sb_oldsave);
 	    POPSUBST(cx);
+	    PERL_ASYNC_CHECK();
 	    RETURNOP(pm->op_next);
 	    assert(0); /* NOTREACHED */
 	}
@@ -304,14 +318,8 @@ PP(pp_substcont)
 	SV * const sv
 	    = (pm->op_pmflags & PMf_NONDESTRUCT) ? cx->sb_dstr : cx->sb_targ;
 	MAGIC *mg;
-	SvUPGRADE(sv, SVt_PVMG);
-	if (!(mg = mg_find(sv, PERL_MAGIC_regex_global))) {
-#ifdef PERL_OLD_COPY_ON_WRITE
-	    if (SvIsCOW(sv))
-		sv_force_normal_flags(sv, 0);
-#endif
-	    mg = sv_magicext(sv, NULL, PERL_MAGIC_regex_global, &PL_vtbl_mglob,
-			     NULL, 0);
+	if (!(mg = mg_find_mglob(sv))) {
+	    mg = sv_magicext_mglob(sv);
 	}
 	mg->mg_len = m - orig;
     }
@@ -320,7 +328,7 @@ PP(pp_substcont)
     /* update the taint state of various various variables in preparation
      * for calling the code block.
      * See "how taint works" above pp_subst() */
-    if (PL_tainting) {
+    if (TAINTING_get) {
 	if (RX_MATCH_TAINTED(rx)) /* run time pattern taint, eg locale */
 	    cx->sb_rxtainted |= SUBST_TAINT_PAT;
 
@@ -351,7 +359,7 @@ Perl_rxres_save(pTHX_ void **rsp, REGEXP *rx)
     PERL_UNUSED_CONTEXT;
 
     if (!p || p[1] < RX_NPARENS(rx)) {
-#ifdef PERL_OLD_COPY_ON_WRITE
+#ifdef PERL_ANY_COW
 	i = 7 + (RX_NPARENS(rx)+1) * 2;
 #else
 	i = 6 + (RX_NPARENS(rx)+1) * 2;
@@ -368,7 +376,7 @@ Perl_rxres_save(pTHX_ void **rsp, REGEXP *rx)
     RX_MATCH_COPIED_off(rx);
     *p++ = RX_NPARENS(rx);
 
-#ifdef PERL_OLD_COPY_ON_WRITE
+#ifdef PERL_ANY_COW
     *p++ = PTR2UV(RX_SAVED_COPY(rx));
     RX_SAVED_COPY(rx) = NULL;
 #endif
@@ -397,7 +405,7 @@ S_rxres_restore(pTHX_ void **rsp, REGEXP *rx)
     *p++ = 0;
     RX_NPARENS(rx) = *p++;
 
-#ifdef PERL_OLD_COPY_ON_WRITE
+#ifdef PERL_ANY_COW
     if (RX_SAVED_COPY(rx))
 	SvREFCNT_dec (RX_SAVED_COPY(rx));
     RX_SAVED_COPY(rx) = INT2PTR(SV*,*p);
@@ -425,14 +433,14 @@ S_rxres_free(pTHX_ void **rsp)
     if (p) {
 	void *tmp = INT2PTR(char*,*p);
 #ifdef PERL_POISON
-#ifdef PERL_OLD_COPY_ON_WRITE
+#ifdef PERL_ANY_COW
 	U32 i = 9 + p[1] * 2;
 #else
 	U32 i = 8 + p[1] * 2;
 #endif
 #endif
 
-#ifdef PERL_OLD_COPY_ON_WRITE
+#ifdef PERL_ANY_COW
         SvREFCNT_dec (INT2PTR(SV*,p[2]));
 #endif
 #ifdef PERL_POISON
@@ -978,6 +986,10 @@ PP(pp_grepstart)
     SAVEVPTR(PL_curpm);
 
     src = PL_stack_base[*PL_markstack_ptr];
+    if (SvPADTMP(src) && !IS_PADGV(src)) {
+	src = PL_stack_base[*PL_markstack_ptr] = sv_mortalcopy(src);
+	PL_tmps_floor++;
+    }
     SvTEMP_off(src);
     if (PL_op->op_private & OPpGREP_LEX)
 	PAD_SVl(PL_op->op_targ) = src;
@@ -1126,6 +1138,7 @@ PP(pp_mapwhile)
 
 	/* set $_ to the new source item */
 	src = PL_stack_base[PL_markstack_ptr[-1]];
+	if (SvPADTMP(src) && !IS_PADGV(src)) src = sv_mortalcopy(src);
 	SvTEMP_off(src);
 	if (PL_op->op_private & OPpGREP_LEX)
 	    PAD_SVl(PL_op->op_targ) = src;
@@ -1420,8 +1433,14 @@ S_dopoptosub_at(pTHX_ const PERL_CONTEXT *cxstk, I32 startingblock)
 	switch (CxTYPE(cx)) {
 	default:
 	    continue;
-	case CXt_EVAL:
 	case CXt_SUB:
+            /* in sub foo { /(?{...})/ }, foo ends up on the CX stack
+             * twice; the first for the normal foo() call, and the second
+             * for a faked up re-entry into the sub to execute the
+             * code block. Hide this faked entry from the world. */
+            if (cx->cx_type & CXp_SUB_RE_FAKE)
+                continue;
+	case CXt_EVAL:
 	case CXt_FORMAT:
 	    DEBUG_l( Perl_deb(aTHX_ "(dopoptosub_at(): found sub at cx=%ld)\n", (long)i));
 	    return i;
@@ -1635,6 +1654,11 @@ Perl_die_unwind(pTHX_ SV *msv)
 	    sv_setsv(ERRSV, exceptsv);
 	}
 
+	if (in_eval & EVAL_KEEPERR) {
+	    Perl_ck_warner(aTHX_ packWARN(WARN_MISC), "\t(in cleanup) %"SVf,
+			   SVfARG(exceptsv));
+	}
+
 	while ((cxix = dopoptoeval(cxstack_ix)) < 0
 	       && PL_curstackinfo->si_prev)
 	{
@@ -1693,13 +1717,8 @@ Perl_die_unwind(pTHX_ SV *msv)
 			   SVfARG(exceptsv ? exceptsv : newSVpvs_flags("Unknown error\n",
                                                                     SVs_TEMP)));
 	    }
-	    if (in_eval & EVAL_KEEPERR) {
-		Perl_ck_warner(aTHX_ packWARN(WARN_MISC), "\t(in cleanup) %"SVf,
-			       SVfARG(exceptsv));
-	    }
-	    else {
+	    if (!(in_eval & EVAL_KEEPERR))
 		sv_setsv(ERRSV, exceptsv);
-	    }
 	    PL_restartjmpenv = restartjmpenv;
 	    PL_restartop = restartop;
 	    JMPENV_JUMP(3);
@@ -1896,9 +1915,6 @@ PP(pp_caller)
 	Copy(AvALLOC(ary), AvARRAY(PL_dbargs), AvFILLp(ary) + 1 + off, SV*);
 	AvFILLp(PL_dbargs) = AvFILLp(ary) + off;
     }
-    /* XXX only hints propagated via op_private are currently
-     * visible (others are not easily accessible, since they
-     * use the global PL_hints) */
     mPUSHi(CopHINTS_get(cx->blk_oldcop));
     {
 	SV * mask ;
@@ -1936,9 +1952,13 @@ PP(pp_reset)
 {
     dVAR;
     dSP;
-    const char * const tmps =
-	(MAXARG < 1 || (!TOPs && !POPs)) ? (const char *)"" : POPpconstx;
-    sv_reset(tmps, CopSTASH(PL_curcop));
+    const char * tmps;
+    STRLEN len = 0;
+    if (MAXARG < 1 || (!TOPs && !POPs))
+	tmps = NULL, len = 0;
+    else
+	tmps = SvPVx_const(POPs, len);
+    sv_resetpvn(tmps, len, CopSTASH(PL_curcop));
     PUSHs(&PL_sv_yes);
     RETURN;
 }
@@ -1963,9 +1983,12 @@ PP(pp_dbstate)
 	const I32 gimme = G_ARRAY;
 	U8 hasargs;
 	GV * const gv = PL_DBgv;
-	CV * const cv = GvCV(gv);
+	CV * cv = NULL;
 
-	if (!cv)
+        if (gv && isGV_with_GP(gv))
+            cv = GvCV(gv);
+
+	if (!cv || (!CvROOT(cv) && !CvXSUB(cv)))
 	    DIE(aTHX_ "No DB::DB routine defined");
 
 	if (CvDEPTH(cv) >= 1 && !(PL_debug & DEBUG_DB_RECURSE_FLAG))
@@ -1993,8 +2016,12 @@ PP(pp_dbstate)
 	    PUSHSUB_DB(cx);
 	    cx->blk_sub.retop = PL_op->op_next;
 	    CvDEPTH(cv)++;
+	    if (CvDEPTH(cv) >= 2) {
+		PERL_STACK_OVERFLOW_CHECK();
+		pad_push(CvPADLIST(cv), CvDEPTH(cv));
+	    }
 	    SAVECOMPPAD();
-	    PAD_SET_CUR_NOSAVE(CvPADLIST(cv), 1);
+	    PAD_SET_CUR_NOSAVE(CvPADLIST(cv), CvDEPTH(cv));
 	    RETURNOP(CvSTART(cv));
 	}
     }
@@ -2650,6 +2677,7 @@ PP(pp_next)
     if (PL_scopestack_ix < inner)
 	leave_scope(PL_scopestack[PL_scopestack_ix]);
     PL_curcop = cx->blk_oldcop;
+    PERL_ASYNC_CHECK();
     return (cx)->blk_loop.my_op->op_nextop;
 }
 
@@ -2673,6 +2701,7 @@ PP(pp_redo)
     LEAVE_SCOPE(oldsave);
     FREETMPS;
     PL_curcop = cx->blk_oldcop;
+    PERL_ASYNC_CHECK();
     return redo_op;
 }
 
@@ -2681,12 +2710,12 @@ S_dofindlabel(pTHX_ OP *o, const char *label, STRLEN len, U32 flags, OP **opstac
 {
     dVAR;
     OP **ops = opstack;
-    static const char too_deep[] = "Target of goto is too deeply nested";
+    static const char* const too_deep = "Target of goto is too deeply nested";
 
     PERL_ARGS_ASSERT_DOFINDLABEL;
 
     if (ops >= oplimit)
-	Perl_croak(aTHX_ too_deep);
+	Perl_croak(aTHX_ "%s", too_deep);
     if (o->op_type == OP_LEAVE ||
 	o->op_type == OP_SCOPE ||
 	o->op_type == OP_LEAVELOOP ||
@@ -2695,7 +2724,7 @@ S_dofindlabel(pTHX_ OP *o, const char *label, STRLEN len, U32 flags, OP **opstac
     {
 	*ops++ = cUNOPo->op_first;
 	if (ops >= oplimit)
-	    Perl_croak(aTHX_ too_deep);
+	    Perl_croak(aTHX_ "%s", too_deep);
     }
     *ops = 0;
     if (o->op_flags & OPf_KIDS) {
@@ -2753,20 +2782,19 @@ PP(pp_goto)
     STRLEN label_len = 0;
     U32 label_flags = 0;
     const bool do_dump = (PL_op->op_type == OP_DUMP);
-    static const char must_have_label[] = "goto must have label";
+    static const char* const must_have_label = "goto must have label";
 
     if (PL_op->op_flags & OPf_STACKED) {
 	SV * const sv = POPs;
+	SvGETMAGIC(sv);
 
 	/* This egregious kludge implements goto &subroutine */
 	if (SvROK(sv) && SvTYPE(SvRV(sv)) == SVt_PVCV) {
 	    I32 cxix;
 	    PERL_CONTEXT *cx;
 	    CV *cv = MUTABLE_CV(SvRV(sv));
-	    SV** mark;
-	    I32 items = 0;
+	    AV *arg = GvAV(PL_defgv);
 	    I32 oldsave;
-	    bool reified = 0;
 
 	retry:
 	    if (!CvROOT(cv) && !CvXSUB(cv)) {
@@ -2793,14 +2821,18 @@ PP(pp_goto)
 	    SvREFCNT_inc_simple_void(cv); /* avoid premature free during unwind */
 	    FREETMPS;
 	    cxix = dopoptosub(cxstack_ix);
-	    if (cxix < 0)
-		DIE(aTHX_ "Can't goto subroutine outside a subroutine");
-	    if (cxix < cxstack_ix)
+	    if (cxix < cxstack_ix) {
+                if (cxix < 0) {
+                    SvREFCNT_dec(cv);
+                    DIE(aTHX_ "Can't goto subroutine outside a subroutine");
+                }
 		dounwind(cxix);
+            }
 	    TOPBLOCK(cx);
 	    SPAGAIN;
 	    /* ban goto in eval: see <20050521150056.GC20213@iabyn.com> */
 	    if (CxTYPE(cx) == CXt_EVAL) {
+		SvREFCNT_dec(cv);
 		if (CxREALEVAL(cx))
 		/* diag_listed_as: Can't goto subroutine from an eval-%s */
 		    DIE(aTHX_ "Can't goto subroutine from an eval-string");
@@ -2809,35 +2841,25 @@ PP(pp_goto)
 		    DIE(aTHX_ "Can't goto subroutine from an eval-block");
 	    }
 	    else if (CxMULTICALL(cx))
+	    {
+		SvREFCNT_dec(cv);
 		DIE(aTHX_ "Can't goto subroutine from a sort sub (or similar callback)");
+	    }
 	    if (CxTYPE(cx) == CXt_SUB && CxHASARGS(cx)) {
-		/* put @_ back onto stack */
 		AV* av = cx->blk_sub.argarray;
 
-		items = AvFILLp(av) + 1;
-		EXTEND(SP, items+1); /* @_ could have been extended. */
-		Copy(AvARRAY(av), SP + 1, items, SV*);
-		SvREFCNT_dec(GvAV(PL_defgv));
-		GvAV(PL_defgv) = cx->blk_sub.savearray;
-		CLEAR_ARGARRAY(av);
-		/* abandon @_ if it got reified */
-		if (AvREAL(av)) {
-		    reified = 1;
+		/* abandon the original @_ if it got reified or if it is
+		   the same as the current @_ */
+		if (AvREAL(av) || av == arg) {
 		    SvREFCNT_dec(av);
 		    av = newAV();
-		    av_extend(av, items-1);
 		    AvREIFY_only(av);
 		    PAD_SVl(0) = MUTABLE_SV(cx->blk_sub.argarray = av);
 		}
+		else CLEAR_ARGARRAY(av);
 	    }
-	    else if (CvISXSUB(cv)) {	/* put GvAV(defgv) back onto stack */
-		AV* const av = GvAV(PL_defgv);
-		items = AvFILLp(av) + 1;
-		EXTEND(SP, items+1); /* @_ could have been extended. */
-		Copy(AvARRAY(av), SP + 1, items, SV*);
-	    }
-	    mark = SP;
-	    SP += items;
+	    /* We donate this refcount later to the callee’s pad. */
+	    SvREFCNT_inc_simple_void(arg);
 	    if (CxTYPE(cx) == CXt_SUB &&
 		!(CvDEPTH(cx->blk_sub.cv) = cx->blk_sub.olddepth))
 		SvREFCNT_dec(cx->blk_sub.cv);
@@ -2848,6 +2870,7 @@ PP(pp_goto)
 	     * our precious cv.  See bug #99850. */
 	    if (!CvROOT(cv) && !CvXSUB(cv)) {
 		const GV * const gv = CvGV(cv);
+		SvREFCNT_dec(arg);
 		if (gv) {
 		    SV * const tmpstr = sv_newmortal();
 		    gv_efullname3(tmpstr, gv, NULL);
@@ -2862,12 +2885,30 @@ PP(pp_goto)
 	    SAVEFREESV(cv); /* later, undo the 'avoid premature free' hack */
 	    if (CvISXSUB(cv)) {
 		OP* const retop = cx->blk_sub.retop;
-		SV **newsp PERL_UNUSED_DECL;
-		I32 gimme PERL_UNUSED_DECL;
-		if (reified) {
+		SV **newsp;
+		I32 gimme;
+		const SSize_t items = AvFILLp(arg) + 1;
+		SV** mark;
+
+                PERL_UNUSED_VAR(newsp);
+                PERL_UNUSED_VAR(gimme);
+
+		/* put GvAV(defgv) back onto stack */
+		EXTEND(SP, items+1); /* @_ could have been extended. */
+		Copy(AvARRAY(arg), SP + 1, items, SV*);
+		mark = SP;
+		SP += items;
+		if (AvREAL(arg)) {
 		    I32 index;
 		    for (index=0; index<items; index++)
-			sv_2mortal(SP[-index]);
+			SvREFCNT_inc_void(sv_2mortal(SP[-index]));
+		}
+		SvREFCNT_dec(arg);
+		if (CxTYPE(cx) == CXt_SUB && CxHASARGS(cx)) {
+		    /* Restore old @_ */
+		    arg = GvAV(PL_defgv);
+		    GvAV(PL_defgv) = cx->blk_sub.savearray;
+		    SvREFCNT_dec(arg);
 		}
 
 		/* XS subs don't have a CxSUB, so pop it */
@@ -2877,15 +2918,11 @@ PP(pp_goto)
 		PUTBACK;
 		(void)(*CvXSUB(cv))(aTHX_ cv);
 		LEAVE;
+		PERL_ASYNC_CHECK();
 		return retop;
 	    }
 	    else {
 		PADLIST * const padlist = CvPADLIST(cv);
-		if (CxTYPE(cx) == CXt_EVAL) {
-		    PL_in_eval = CxOLD_IN_EVAL(cx);
-		    PL_eval_root = cx->blk_eval.old_eval_root;
-		    cx->cx_type = CXt_SUB;
-		}
 		cx->blk_sub.cv = cv;
 		cx->blk_sub.olddepth = CvDEPTH(cv);
 
@@ -2902,41 +2939,26 @@ PP(pp_goto)
 		PAD_SET_CUR_NOSAVE(padlist, CvDEPTH(cv));
 		if (CxHASARGS(cx))
 		{
-		    AV *const av = MUTABLE_AV(PAD_SVl(0));
-
-		    cx->blk_sub.savearray = GvAV(PL_defgv);
-		    GvAV(PL_defgv) = MUTABLE_AV(SvREFCNT_inc_simple(av));
 		    CX_CURPAD_SAVE(cx->blk_sub);
-		    cx->blk_sub.argarray = av;
 
-		    if (items >= AvMAX(av) + 1) {
-			SV **ary = AvALLOC(av);
-			if (AvARRAY(av) != ary) {
-			    AvMAX(av) += AvARRAY(av) - AvALLOC(av);
-			    AvARRAY(av) = ary;
-			}
-			if (items >= AvMAX(av) + 1) {
-			    AvMAX(av) = items - 1;
-			    Renew(ary,items+1,SV*);
-			    AvALLOC(av) = ary;
-			    AvARRAY(av) = ary;
-			}
-		    }
-		    ++mark;
-		    Copy(mark,AvARRAY(av),items,SV*);
-		    AvFILLp(av) = items - 1;
-		    assert(!AvREAL(av));
-		    if (reified) {
-			/* transfer 'ownership' of refcnts to new @_ */
-			AvREAL_on(av);
-			AvREIFY_off(av);
-		    }
-		    while (items--) {
-			if (*mark)
-			    SvTEMP_off(*mark);
-			mark++;
+		    /* cx->blk_sub.argarray has no reference count, so we
+		       need something to hang on to our argument array so
+		       that cx->blk_sub.argarray does not end up pointing
+		       to freed memory as the result of undef *_.  So put
+		       it in the callee’s pad, donating our refer-
+		       ence count. */
+		    SvREFCNT_dec(PAD_SVl(0));
+		    PAD_SVl(0) = (SV *)(cx->blk_sub.argarray = arg);
+
+		    /* GvAV(PL_defgv) might have been modified on scope
+		       exit, so restore it. */
+		    if (arg != GvAV(PL_defgv)) {
+			AV * const av = GvAV(PL_defgv);
+			GvAV(PL_defgv) = (AV *)SvREFCNT_inc_simple(arg);
+			SvREFCNT_dec(av);
 		    }
 		}
+		else SvREFCNT_dec(arg);
 		if (PERLDB_SUB) {	/* Checking curstash breaks DProf. */
 		    Perl_get_db_sub(aTHX_ NULL, cv);
 		    if (PERLDB_GOTO) {
@@ -2948,11 +2970,12 @@ PP(pp_goto)
 			}
 		    }
 		}
+		PERL_ASYNC_CHECK();
 		RETURNOP(CvSTART(cv));
 	    }
 	}
 	else {
-	    label       = SvPV_const(sv, label_len);
+	    label       = SvPV_nomg_const(sv, label_len);
             label_flags = SvUTF8(sv);
 	}
     }
@@ -2961,7 +2984,7 @@ PP(pp_goto)
         label_flags = (cPVOP->op_private & OPpPV_IS_UTF8) ? SVf_UTF8 : 0;
         label_len   = strlen(label);
     }
-    if (!(do_dump || label_len)) DIE(aTHX_ must_have_label);
+    if (!(do_dump || label_len)) DIE(aTHX_ "%s", must_have_label);
 
     PERL_ASYNC_CHECK();
 
@@ -3039,9 +3062,8 @@ PP(pp_goto)
 	    PL_lastgotoprobe = gotoprobe;
 	}
 	if (!retop)
-	    DIE(aTHX_ "Can't find label %"SVf,
-                            SVfARG(newSVpvn_flags(label, label_len,
-                                        SVs_TEMP | label_flags)));
+	    DIE(aTHX_ "Can't find label %"UTF8f, 
+		       UTF8fARG(label_flags, label_len, label));
 
 	/* if we're leaving an eval, check before we pop any frames
            that we're not going to punt, otherwise the error
@@ -3103,6 +3125,7 @@ PP(pp_goto)
 	PL_do_undump = FALSE;
     }
 
+    PERL_ASYNC_CHECK();
     RETURNOP(retop);
 }
 
@@ -3248,7 +3271,11 @@ Perl_find_runcv_where(pTHX_ U8 cond, IV arg, U32 *db_seqp)
     int		 level = 0;
 
     if (db_seqp)
-	*db_seqp = PL_curcop->cop_seq;
+	*db_seqp =
+            PL_curcop == &PL_compiling
+                ? PL_cop_seqmax
+                : PL_curcop->cop_seq;
+
     for (si = PL_curstackinfo; si; si = si->si_prev) {
         I32 ix;
 	for (ix = si->si_cxix; ix >= 0; ix--) {
@@ -3261,6 +3288,8 @@ Perl_find_runcv_where(pTHX_ U8 cond, IV arg, U32 *db_seqp)
 		    *db_seqp = cx->blk_oldcop->cop_seq;
 		    continue;
 		}
+                if (cx->cx_type & CXp_SUB_RE)
+                    continue;
 	    }
 	    else if (CxTYPE(cx) == CXt_EVAL && !CxTRYBLOCK(cx))
 		cv = cx->blk_eval.cv;
@@ -3268,7 +3297,8 @@ Perl_find_runcv_where(pTHX_ U8 cond, IV arg, U32 *db_seqp)
 		switch (cond) {
 		case FIND_RUNCV_padid_eq:
 		    if (!CvPADLIST(cv)
-		     || CvPADLIST(cv)->xpadl_id != (U32)arg) continue;
+		     || PadlistNAMES(CvPADLIST(cv)) != INT2PTR(PADNAMELIST *, arg))
+			continue;
 		    return cv;
 		case FIND_RUNCV_level_eq:
 		    if (level++ != arg) continue;
@@ -3339,7 +3369,9 @@ S_doeval(pTHX_ int gimme, CV* outside, U32 seq, HV *hh)
 
     PL_in_eval = (in_require
 		  ? (EVAL_INREQUIRE | (PL_in_eval & EVAL_INEVAL))
-		  : EVAL_INEVAL);
+		  : (EVAL_INEVAL |
+                        ((PL_op->op_private & OPpEVAL_RE_REPARSING)
+                            ? EVAL_RE_REPARSING : 0)));
 
     PUSHMARK(SP);
 
@@ -3365,7 +3397,9 @@ S_doeval(pTHX_ int gimme, CV* outside, U32 seq, HV *hh)
 
     if (CopSTASH_ne(PL_curcop, PL_curstash)) {
 	SAVEGENERICSV(PL_curstash);
-	PL_curstash = (HV *)SvREFCNT_inc_simple(CopSTASH(PL_curcop));
+	PL_curstash = (HV *)CopSTASH(PL_curcop);
+	if (SvTYPE(PL_curstash) != SVt_PVHV) PL_curstash = NULL;
+	else SvREFCNT_inc_simple_void(PL_curstash);
     }
     /* XXX:ajgo do we really need to alloc an AV for begin/checkunit */
     SAVESPTR(PL_beginav);
@@ -3401,6 +3435,15 @@ S_doeval(pTHX_ int gimme, CV* outside, U32 seq, HV *hh)
     else {
 	PL_hints = saveop->op_private & OPpEVAL_COPHH
 		     ? oldcurcop->cop_hints : saveop->op_targ;
+
+        /* making 'use re eval' not be in scope when compiling the
+         * qr/mabye_has_runtime_code_block/ ensures that we don't get
+         * infinite recursion when S_has_runtime_code() gives a false
+         * positive: the second time round, HINT_RE_EVAL isn't set so we
+         * don't bother calling S_has_runtime_code() */
+        if (PL_in_eval & EVAL_RE_REPARSING)
+            PL_hints &= ~HINT_RE_EVAL;
+
 	if (hh) {
 	    /* SAVEHINTS created a new HV in PL_hintgv, which we need to GC */
 	    SvREFCNT_dec(GvHV(PL_hintgv));
@@ -3445,6 +3488,7 @@ S_doeval(pTHX_ int gimme, CV* outside, U32 seq, HV *hh)
 	PERL_CONTEXT *cx;
 	I32 optype;			/* Used by POPEVAL. */
 	SV *namesv;
+        SV *errsv = NULL;
 
 	cx = NULL;
 	namesv = NULL;
@@ -3456,7 +3500,6 @@ S_doeval(pTHX_ int gimme, CV* outside, U32 seq, HV *hh)
 	PL_op = saveop;
 	if (yystatus != 3) {
 	    if (PL_eval_root) {
-		cv_forget_slab(evalcv);
 		op_free(PL_eval_root);
 		PL_eval_root = NULL;
 	    }
@@ -3468,6 +3511,7 @@ S_doeval(pTHX_ int gimme, CV* outside, U32 seq, HV *hh)
 	    LEAVE_with_name("eval"); /* pp_entereval knows about this LEAVE.  */
 	}
 
+	errsv = ERRSV;
 	if (in_require) {
 	    if (!cx) {
 		/* If cx is still NULL, it means that we didn't go in the
@@ -3481,13 +3525,13 @@ S_doeval(pTHX_ int gimme, CV* outside, U32 seq, HV *hh)
                            SvUTF8(namesv) ? -(I32)SvCUR(namesv) : (I32)SvCUR(namesv),
 			   &PL_sv_undef, 0);
 	    Perl_croak(aTHX_ "%"SVf"Compilation failed in require",
-		       SVfARG(ERRSV
-                                ? ERRSV
+		       SVfARG(errsv
+                                ? errsv
                                 : newSVpvs_flags("Unknown error\n", SVs_TEMP)));
 	}
 	else {
-	    if (!*(SvPVx_nolen_const(ERRSV))) {
-	        sv_setpvs(ERRSV, "Compilation error");
+	    if (!*(SvPV_nolen_const(errsv))) {
+	        sv_setpvs(errsv, "Compilation error");
 	    }
 	}
 	if (gimme != G_ARRAY) PUSHs(&PL_sv_undef);
@@ -3577,6 +3621,32 @@ S_doopen_pm(pTHX_ SV *name)
 #  define doopen_pm(name) check_type_and_open(name)
 #endif /* !PERL_DISABLE_PMC */
 
+/* require doesn't search for absolute names, or when the name is
+   explicity relative the current directory */
+PERL_STATIC_INLINE bool
+S_path_is_searchable(const char *name)
+{
+    PERL_ARGS_ASSERT_PATH_IS_SEARCHABLE;
+
+    if (PERL_FILE_IS_ABSOLUTE(name)
+#ifdef WIN32
+	|| (*name == '.' && ((name[1] == '/' ||
+			     (name[1] == '.' && name[2] == '/'))
+			 || (name[1] == '\\' ||
+			     ( name[1] == '.' && name[2] == '\\')))
+	    )
+#else
+	|| (*name == '.' && (name[1] == '/' ||
+			     (name[1] == '.' && name[2] == '/')))
+#endif
+	 )
+    {
+	return FALSE;
+    }
+    else
+	return TRUE;
+}
+
 PP(pp_require)
 {
     dVAR; dSP;
@@ -3604,11 +3674,12 @@ PP(pp_require)
     SV *encoding;
     OP *op;
     int saved_errno;
+    bool path_searchable;
 
     sv = POPs;
     if ( (SvNIOKp(sv) || SvVOK(sv)) && PL_op->op_type != OP_DOFILE) {
 	sv = sv_2mortal(new_version(sv));
-	if (!sv_derived_from(PL_patchlevel, "version"))
+	if (!Perl_sv_derived_from_pvn(aTHX_ PL_patchlevel, STR_WITH_LEN("version"), 0))
 	    upg_version(PL_patchlevel, TRUE);
 	if (cUNOP->op_first->op_type == OP_CONST && cUNOP->op_first->op_private & OPpCONST_NOVER) {
 	    if ( vcmp(sv,PL_patchlevel) <= 0 )
@@ -3668,6 +3739,7 @@ PP(pp_require)
 	DIE(aTHX_ "Null filename used");
     TAINT_PROPER("require");
 
+    path_searchable = path_is_searchable(name);
 
 #ifdef VMS
     /* The key in the %ENV hash is in the syntax of file passed as the argument
@@ -3707,12 +3779,12 @@ PP(pp_require)
 
     /* prepare to compile file */
 
-    if (path_is_absolute(name)) {
+    if (!path_searchable) {
 	/* At this point, name is SvPVX(sv)  */
 	tryname = name;
 	tryrsfp = doopen_pm(sv);
     }
-    if (!tryrsfp && !(errno == EACCES && path_is_absolute(name))) {
+    if (!tryrsfp && !(errno == EACCES && !path_searchable)) {
 	AV * const ar = GvAVn(PL_incgv);
 	I32 i;
 #ifdef VMS
@@ -3765,7 +3837,6 @@ PP(pp_require)
 			if (SvROK(arg) && (SvTYPE(SvRV(arg)) <= SVt_PVLV)
 			    && !isGV_with_GP(SvRV(arg))) {
 			    filter_cache = SvRV(arg);
-			    SvREFCNT_inc_simple_void_NN(filter_cache);
 
 			    if (i < count) {
 				arg = SP[i++];
@@ -3828,10 +3899,7 @@ PP(pp_require)
 		    }
 
 		    filter_has_file = 0;
-		    if (filter_cache) {
-			SvREFCNT_dec(filter_cache);
-			filter_cache = NULL;
-		    }
+		    filter_cache = NULL;
 		    if (filter_state) {
 			SvREFCNT_dec(filter_state);
 			filter_state = NULL;
@@ -3842,8 +3910,7 @@ PP(pp_require)
 		    }
 		}
 		else {
-		  if (!path_is_absolute(name)
-		  ) {
+		  if (path_searchable) {
 		    const char *dir;
 		    STRLEN dirlen;
 
@@ -3884,7 +3951,12 @@ PP(pp_require)
 
 			memcpy(tmp, dir, dirlen);
 			tmp +=dirlen;
-			*tmp++ = '/';
+
+			/* Avoid '<dir>//<file>' */
+			if (!dirlen || *(tmp-1) != '/') {
+			    *tmp++ = '/';
+			}
+
 			/* name came from an SV, so it will have a '\0' at the
 			   end that we can copy as part of this memcpy().  */
 			memcpy(tmp, name, len + 1);
@@ -3900,7 +3972,7 @@ PP(pp_require)
 		    if (tryrsfp) {
 			if (tryname[0] == '.' && tryname[1] == '/') {
 			    ++tryname;
-			    while (*++tryname == '/');
+			    while (*++tryname == '/') {}
 			}
 			break;
 		    }
@@ -3928,22 +4000,36 @@ PP(pp_require)
 	        if (namesv) {			/* did we lookup @INC? */
 		    AV * const ar = GvAVn(PL_incgv);
 		    I32 i;
+		    SV *const msg = newSVpvs_flags("", SVs_TEMP);
 		    SV *const inc = newSVpvs_flags("", SVs_TEMP);
 		    for (i = 0; i <= AvFILL(ar); i++) {
 			sv_catpvs(inc, " ");
 			sv_catsv(inc, *av_fetch(ar, i, TRUE));
 		    }
+		    if (len >= 4 && memEQ(name + len - 3, ".pm", 4)) {
+			const char *c, *e = name + len - 3;
+			sv_catpv(msg, " (you may need to install the ");
+			for (c = name; c < e; c++) {
+			    if (*c == '/') {
+				sv_catpvn(msg, "::", 2);
+			    }
+			    else {
+				sv_catpvn(msg, c, 1);
+			    }
+			}
+			sv_catpv(msg, " module)");
+		    }
+		    else if (len >= 2 && memEQ(name + len - 2, ".h", 3)) {
+			sv_catpv(msg, " (change .h to .ph maybe?) (did you run h2ph?)");
+		    }
+		    else if (len >= 3 && memEQ(name + len - 3, ".ph", 4)) {
+			sv_catpv(msg, " (did you run h2ph?)");
+		    }
 
 		    /* diag_listed_as: Can't locate %s */
 		    DIE(aTHX_
-			"Can't locate %s in @INC%s%s (@INC contains:%" SVf ")",
-			name,
-			(len >= 2 && memEQ(name + len - 2, ".h", 3)
-			 ? " (change .h to .ph maybe?) (did you run h2ph?)" : ""),
-			(len >= 3 && memEQ(name + len - 3, ".ph", 4)
-			 ? " (did you run h2ph?)" : ""),
-			inc
-			);
+			"Can't locate %s in @INC%" SVf " (@INC contains:%" SVf ")",
+			name, msg, inc);
 		}
 	    }
 	    DIE(aTHX_ "Can't locate %s", name);
@@ -3979,7 +4065,10 @@ PP(pp_require)
 	   than hanging another SV from it. In turn, filter_add() optionally
 	   takes the SV to use as the filter (or creates a new SV if passed
 	   NULL), so simply pass in whatever value filter_cache has.  */
-	SV * const datasv = filter_add(S_run_user_filter, filter_cache);
+	SV * const fc = filter_cache ? newSV(0) : NULL;
+	SV *datasv;
+	if (fc) sv_copypv(fc, filter_cache);
+	datasv = filter_add(S_run_user_filter, fc);
 	IoLINES(datasv) = filter_has_file;
 	IoTOP_GV(datasv) = MUTABLE_GV(filter_state);
 	IoBOTTOM_GV(datasv) = MUTABLE_GV(filter_sub);
@@ -4916,10 +5005,13 @@ PP(pp_leavewhen)
 	    leave_scope(PL_scopestack[PL_scopestack_ix]);
 	PL_curcop = cx->blk_oldcop;
 
+	PERL_ASYNC_CHECK();
 	return cx->blk_loop.my_op->op_nextop;
     }
-    else
+    else {
+	PERL_ASYNC_CHECK();
 	RETURNOP(cx->blk_givwhen.leave_op);
+    }
 }
 
 PP(pp_continue)
@@ -5351,11 +5443,14 @@ S_run_user_filter(pTHX_ int idx, SV *buf_sv, int maxlen)
 
 	if (count > 0) {
 	    SV *out = POPs;
+	    SvGETMAGIC(out);
 	    if (SvOK(out)) {
 		status = SvIV(out);
 	    }
-            else if (SvTRUE(ERRSV)) {
-                err = newSVsv(ERRSV);
+            else {
+                SV * const errsv = ERRSV;
+                if (SvTRUE_NN(errsv))
+                    err = newSVsv(errsv);
             }
 	}
 
@@ -5364,8 +5459,13 @@ S_run_user_filter(pTHX_ int idx, SV *buf_sv, int maxlen)
 	LEAVE_with_name("call_filter_sub");
     }
 
+    if (SvGMAGICAL(upstream)) {
+	mg_get(upstream);
+	if (upstream == buf_sv) mg_free(buf_sv);
+    }
+    if (SvIsCOW(upstream)) sv_force_normal(upstream);
     if(!err && SvOK(upstream)) {
-	got_p = SvPV(upstream, got_len);
+	got_p = SvPV_nomg(upstream, got_len);
 	if (umaxlen) {
 	    if (got_len > umaxlen) {
 		prune_from = got_p + umaxlen;
@@ -5396,7 +5496,12 @@ S_run_user_filter(pTHX_ int idx, SV *buf_sv, int maxlen)
 	if (SvUTF8(upstream)) {
 	    SvUTF8_on(cache);
 	}
-	SvCUR_set(upstream, got_len - cached_len);
+	if (SvPOK(upstream)) SvCUR_set(upstream, got_len - cached_len);
+	else
+	    /* Cannot just use sv_setpvn, as that could free the buffer
+	       before we have a chance to assign it. */
+	    sv_usepvn(upstream, savepvn(got_p, got_len - cached_len),
+		      got_len - cached_len);
 	*prune_from = 0;
 	/* Can't yet be EOF  */
 	if (status == 0)
@@ -5408,9 +5513,10 @@ S_run_user_filter(pTHX_ int idx, SV *buf_sv, int maxlen)
        concatenate it then we get a warning about use of uninitialised value.
     */
     if (!err && upstream != buf_sv &&
-        (SvOK(upstream) || SvGMAGICAL(upstream))) {
-	sv_catsv(buf_sv, upstream);
+        SvOK(upstream)) {
+	sv_catsv_nomg(buf_sv, upstream);
     }
+    else if (SvOK(upstream)) (void)SvPV_force_nolen(buf_sv);
 
     if (status <= 0) {
 	IoLINES(datasv) = 0;
@@ -5437,32 +5543,6 @@ S_run_user_filter(pTHX_ int idx, SV *buf_sv, int maxlen)
     return status;
 }
 
-/* perhaps someone can come up with a better name for
-   this?  it is not really "absolute", per se ... */
-static bool
-S_path_is_absolute(const char *name)
-{
-    PERL_ARGS_ASSERT_PATH_IS_ABSOLUTE;
-
-    if (PERL_FILE_IS_ABSOLUTE(name)
-#ifdef WIN32
-	|| (*name == '.' && ((name[1] == '/' ||
-			     (name[1] == '.' && name[2] == '/'))
-			 || (name[1] == '\\' ||
-			     ( name[1] == '.' && name[2] == '\\')))
-	    )
-#else
-	|| (*name == '.' && (name[1] == '/' ||
-			     (name[1] == '.' && name[2] == '/')))
-#endif
-	 )
-    {
-	return TRUE;
-    }
-    else
-    	return FALSE;
-}
-
 /*
  * Local variables:
  * c-indentation-style: bsd