X-Git-Url: https://perl5.git.perl.org/perl5.git/blobdiff_plain/7a5fd60d4ce737f71e7a689eaa2061a36dd225dc..a7fce7e16a936eb048fedb9b30adc592bcb2c657:/mg.c

diff --git a/mg.c b/mg.c
index 8315721..b04e24f 100644
--- a/mg.c
+++ b/mg.c
@@ -54,17 +54,8 @@ tie.
 
 Signal_t Perl_csighandler(int sig);
 
-/* if you only have signal() and it resets on each signal, FAKE_PERSISTENT_SIGNAL_HANDLERS fixes */
-#if !defined(HAS_SIGACTION) && defined(VMS)
-#  define  FAKE_PERSISTENT_SIGNAL_HANDLERS
-#endif
-/* if we're doing kill() with sys$sigprc on VMS, FAKE_DEFAULT_SIGNAL_HANDLERS */
-#if defined(KILL_BY_SIGPRC)
-#  define  FAKE_DEFAULT_SIGNAL_HANDLERS
-#endif
-
-static void restore_magic(pTHX_ void *p);
-static void unwind_handler_stack(pTHX_ void *p);
+static void restore_magic(pTHX_ const void *p);
+static void unwind_handler_stack(pTHX_ const void *p);
 
 #ifdef __Lynx__
 /* Missing protos on LynxOS */
@@ -119,9 +110,9 @@ Turns on the magical status of an SV.  See C<sv_magic>.
 void
 Perl_mg_magical(pTHX_ SV *sv)
 {
-    MAGIC* mg;
+    const MAGIC* mg;
     for (mg = SvMAGIC(sv); mg; mg = mg->mg_moremagic) {
-	MGVTBL* vtbl = mg->mg_virtual;
+	const MGVTBL* const vtbl = mg->mg_virtual;
 	if (vtbl) {
 	    if (vtbl->svt_get && !(mg->mg_flags & MGf_GSKIP))
 		SvGMAGICAL_on(sv);
@@ -144,10 +135,10 @@ Do magic after a value is retrieved from the SV.  See C<sv_magic>.
 int
 Perl_mg_get(pTHX_ SV *sv)
 {
-    int new = 0;
+    const I32 mgs_ix = SSNEW(sizeof(MGS));
+    const bool was_temp = (bool)SvTEMP(sv);
+    int have_new = 0;
     MAGIC *newmg, *head, *cur, *mg;
-    I32 mgs_ix = SSNEW(sizeof(MGS));
-    int was_temp = SvTEMP(sv);
     /* guard against sv having being freed midway by holding a private
        reference. */
 
@@ -168,7 +159,7 @@ Perl_mg_get(pTHX_ SV *sv)
 
     newmg = cur = head = mg = SvMAGIC(sv);
     while (mg) {
-	MGVTBL *vtbl = mg->mg_virtual;
+	const MGVTBL * const vtbl = mg->mg_virtual;
 
 	if (!(mg->mg_flags & MGf_GSKIP) && vtbl && vtbl->svt_get) {
 	    CALL_FPTR(vtbl->svt_get)(aTHX_ sv, mg);
@@ -185,19 +176,19 @@ Perl_mg_get(pTHX_ SV *sv)
 
 	mg = mg->mg_moremagic;
 
-	if (new) {
+	if (have_new) {
 	    /* Have we finished with the new entries we saw? Start again
 	       where we left off (unless there are more new entries). */
 	    if (mg == head) {
-		new  = 0;
+		have_new = 0;
 		mg   = cur;
 		head = newmg;
 	    }
 	}
 
 	/* Were any new entries added? */
-	if (!new && (newmg = SvMAGIC(sv)) != head) {
-	    new = 1;
+	if (!have_new && (newmg = SvMAGIC(sv)) != head) {
+	    have_new = 1;
 	    cur = mg;
 	    mg  = newmg;
 	}
@@ -224,15 +215,14 @@ Do magic after a value is assigned to the SV.  See C<sv_magic>.
 int
 Perl_mg_set(pTHX_ SV *sv)
 {
-    I32 mgs_ix;
+    const I32 mgs_ix = SSNEW(sizeof(MGS));
     MAGIC* mg;
     MAGIC* nextmg;
 
-    mgs_ix = SSNEW(sizeof(MGS));
     save_magic(mgs_ix, sv);
 
     for (mg = SvMAGIC(sv); mg; mg = nextmg) {
-	MGVTBL* vtbl = mg->mg_virtual;
+        const MGVTBL* vtbl = mg->mg_virtual;
 	nextmg = mg->mg_moremagic;	/* it may delete itself */
 	if (mg->mg_flags & MGf_GSKIP) {
 	    mg->mg_flags &= ~MGf_GSKIP;	/* setting requires another read */
@@ -261,11 +251,9 @@ Perl_mg_length(pTHX_ SV *sv)
     STRLEN len;
 
     for (mg = SvMAGIC(sv); mg; mg = mg->mg_moremagic) {
-	MGVTBL* vtbl = mg->mg_virtual;
+        const MGVTBL * const vtbl = mg->mg_virtual;
 	if (vtbl && vtbl->svt_len) {
-            I32 mgs_ix;
-
-	    mgs_ix = SSNEW(sizeof(MGS));
+            const I32 mgs_ix = SSNEW(sizeof(MGS));
 	    save_magic(mgs_ix, sv);
 	    /* omit MGf_GSKIP -- not changed here */
 	    len = CALL_FPTR(vtbl->svt_len)(aTHX_ sv, mg);
@@ -274,8 +262,7 @@ Perl_mg_length(pTHX_ SV *sv)
 	}
     }
 
-    if (DO_UTF8(sv))
-    {
+    if (DO_UTF8(sv)) {
         U8 *s = (U8*)SvPV(sv, len);
         len = Perl_utf8_length(aTHX_ s, s + len);
     }
@@ -288,14 +275,12 @@ I32
 Perl_mg_size(pTHX_ SV *sv)
 {
     MAGIC* mg;
-    I32 len;
 
     for (mg = SvMAGIC(sv); mg; mg = mg->mg_moremagic) {
-	MGVTBL* vtbl = mg->mg_virtual;
+        const MGVTBL* const vtbl = mg->mg_virtual;
 	if (vtbl && vtbl->svt_len) {
-            I32 mgs_ix;
-
-	    mgs_ix = SSNEW(sizeof(MGS));
+            const I32 mgs_ix = SSNEW(sizeof(MGS));
+            I32 len;
 	    save_magic(mgs_ix, sv);
 	    /* omit MGf_GSKIP -- not changed here */
 	    len = CALL_FPTR(vtbl->svt_len)(aTHX_ sv, mg);
@@ -306,8 +291,7 @@ Perl_mg_size(pTHX_ SV *sv)
 
     switch(SvTYPE(sv)) {
 	case SVt_PVAV:
-	    len = AvFILLp((AV *) sv); /* Fallback to non-tied array */
-	    return len;
+	    return AvFILLp((AV *) sv); /* Fallback to non-tied array */
 	case SVt_PVHV:
 	    /* FIXME */
 	default:
@@ -328,14 +312,13 @@ Clear something magical that the SV represents.  See C<sv_magic>.
 int
 Perl_mg_clear(pTHX_ SV *sv)
 {
-    I32 mgs_ix;
+    const I32 mgs_ix = SSNEW(sizeof(MGS));
     MAGIC* mg;
 
-    mgs_ix = SSNEW(sizeof(MGS));
     save_magic(mgs_ix, sv);
 
     for (mg = SvMAGIC(sv); mg; mg = mg->mg_moremagic) {
-	MGVTBL* vtbl = mg->mg_virtual;
+        const MGVTBL* const vtbl = mg->mg_virtual;
 	/* omit GSKIP -- never set here */
 
 	if (vtbl && vtbl->svt_clear)
@@ -355,14 +338,14 @@ Finds the magic pointer for type matching the SV.  See C<sv_magic>.
 */
 
 MAGIC*
-Perl_mg_find(pTHX_ SV *sv, int type)
+Perl_mg_find(pTHX_ const SV *sv, int type)
 {
-    MAGIC* mg;
-    if (!sv)
-        return 0;
-    for (mg = SvMAGIC(sv); mg; mg = mg->mg_moremagic) {
-	if (mg->mg_type == type)
-	    return mg;
+    if (sv) {
+        MAGIC *mg;
+        for (mg = SvMAGIC(sv); mg; mg = mg->mg_moremagic) {
+            if (mg->mg_type == type)
+                return mg;
+        }
     }
     return 0;
 }
@@ -381,7 +364,7 @@ Perl_mg_copy(pTHX_ SV *sv, SV *nsv, const char *key, I32 klen)
     int count = 0;
     MAGIC* mg;
     for (mg = SvMAGIC(sv); mg; mg = mg->mg_moremagic) {
-	MGVTBL* vtbl = mg->mg_virtual;
+        const MGVTBL* const vtbl = mg->mg_virtual;
 	if ((mg->mg_flags & MGf_COPY) && vtbl->svt_copy){
 	    count += CALL_FPTR(vtbl->svt_copy)(aTHX_ sv, mg, nsv, key, klen);
 	}
@@ -411,7 +394,7 @@ Perl_mg_free(pTHX_ SV *sv)
     MAGIC* mg;
     MAGIC* moremagic;
     for (mg = SvMAGIC(sv); mg; mg = moremagic) {
-	MGVTBL* vtbl = mg->mg_virtual;
+        const MGVTBL* const vtbl = mg->mg_virtual;
 	moremagic = mg->mg_moremagic;
 	if (vtbl && vtbl->svt_free)
 	    CALL_FPTR(vtbl->svt_free)(aTHX_ sv, mg);
@@ -425,7 +408,7 @@ Perl_mg_free(pTHX_ SV *sv)
 	    SvREFCNT_dec(mg->mg_obj);
 	Safefree(mg);
     }
-    SvMAGIC(sv) = 0;
+    SvMAGIC_set(sv, NULL);
     return 0;
 }
 
@@ -434,7 +417,8 @@ Perl_mg_free(pTHX_ SV *sv)
 U32
 Perl_magic_regdata_cnt(pTHX_ SV *sv, MAGIC *mg)
 {
-    register REGEXP *rx;
+    register const REGEXP *rx;
+    (void)sv;
 
     if (PL_curpm && (rx = PM_GETRE(PL_curpm))) {
 	if (mg->mg_obj)		/* @+ */
@@ -449,20 +433,19 @@ Perl_magic_regdata_cnt(pTHX_ SV *sv, MAGIC *mg)
 int
 Perl_magic_regdatum_get(pTHX_ SV *sv, MAGIC *mg)
 {
-    register I32 paren;
-    register I32 s;
-    register I32 i;
     register REGEXP *rx;
-    I32 t;
 
     if (PL_curpm && (rx = PM_GETRE(PL_curpm))) {
-	paren = mg->mg_len;
+        register const I32 paren = mg->mg_len;
+        register I32 s;
+        register I32 t;
 	if (paren < 0)
 	    return 0;
 	if (paren <= (I32)rx->nparens &&
 	    (s = rx->startp[paren]) != -1 &&
 	    (t = rx->endp[paren]) != -1)
 	    {
+                register I32 i;
 		if (mg->mg_obj)		/* @+ */
 		    i = t;
 		else			/* @- */
@@ -483,9 +466,14 @@ Perl_magic_regdatum_get(pTHX_ SV *sv, MAGIC *mg)
 int
 Perl_magic_regdatum_set(pTHX_ SV *sv, MAGIC *mg)
 {
+    (void)sv; (void)mg;
     Perl_croak(aTHX_ PL_no_modify);
     /* NOT REACHED */
+#ifndef HASATTRIBUTE
+    /* No __attribute__, so the compiler doesn't know that croak never returns
+     */
     return 0;
+#endif
 }
 
 U32
@@ -493,7 +481,7 @@ Perl_magic_len(pTHX_ SV *sv, MAGIC *mg)
 {
     register I32 paren;
     register I32 i;
-    register REGEXP *rx;
+    register const REGEXP *rx;
     I32 s1, t1;
 
     switch (*mg->mg_ptr) {
@@ -583,6 +571,7 @@ Perl_magic_len(pTHX_ SV *sv, MAGIC *mg)
 int
 Perl_magic_get(pTHX_ SV *sv, MAGIC *mg)
 {
+    dVAR;
     register I32 paren;
     register char *s = NULL;
     register I32 i;
@@ -780,11 +769,11 @@ Perl_magic_get(pTHX_ SV *sv, MAGIC *mg)
 			    MAGIC* mg = SvMAGIC(sv);
 			    MAGIC* mgt;
 			    PL_tainted = 1;
-			    SvMAGIC(sv) = mg->mg_moremagic;
+			    SvMAGIC_set(sv, mg->mg_moremagic);
 			    SvTAINT(sv);
 			    if ((mgt = SvMAGIC(sv))) {
 				mg->mg_moremagic = mgt;
-				SvMAGIC(sv) = mg;
+				SvMAGIC_set(sv, mg);
 			    }
 			} else
 			    SvTAINTED_off(sv);
@@ -965,6 +954,7 @@ Perl_magic_getuvar(pTHX_ SV *sv, MAGIC *mg)
 int
 Perl_magic_setenv(pTHX_ SV *sv, MAGIC *mg)
 {
+    dVAR;
     register char *s;
     char *ptr;
     STRLEN len, klen;
@@ -1042,6 +1032,7 @@ int
 Perl_magic_clearenv(pTHX_ SV *sv, MAGIC *mg)
 {
     STRLEN n_a;
+    (void)sv;
     my_setenv(MgPV(mg,n_a),Nullch);
     return 0;
 }
@@ -1049,7 +1040,7 @@ Perl_magic_clearenv(pTHX_ SV *sv, MAGIC *mg)
 int
 Perl_magic_set_all_env(pTHX_ SV *sv, MAGIC *mg)
 {
-#if defined(VMS)
+#if defined(VMS) || defined(EPOC) || defined(SYMBIAN)
     Perl_die(aTHX_ "Can't make list assignment to %%ENV on this system");
 #else
     if (PL_localizing) {
@@ -1070,8 +1061,9 @@ Perl_magic_set_all_env(pTHX_ SV *sv, MAGIC *mg)
 int
 Perl_magic_clear_all_env(pTHX_ SV *sv, MAGIC *mg)
 {
+    dVAR;
 #ifndef PERL_MICRO
-#if defined(VMS) || defined(EPOC)
+#if defined(VMS) || defined(EPOC) || defined(SYMBIAN)
     Perl_die(aTHX_ "Can't make list assignment to %%ENV on this system");
 #else
 #  if defined(PERL_IMPLICIT_SYS) || defined(WIN32)
@@ -1101,19 +1093,11 @@ Perl_magic_clear_all_env(pTHX_ SV *sv, MAGIC *mg)
 #   endif /* PERL_IMPLICIT_SYS || WIN32 */
 #endif /* VMS || EPOC */
 #endif /* !PERL_MICRO */
+    (void)sv;
+    (void)mg;
     return 0;
 }
 
-#if defined(FAKE_PERSISTENT_SIGNAL_HANDLERS)||defined(FAKE_DEFAULT_SIGNAL_HANDLERS)
-static int sig_handlers_initted = 0;
-#endif
-#ifdef FAKE_PERSISTENT_SIGNAL_HANDLERS
-static int sig_ignoring[SIG_SIZE];      /* which signals we are ignoring */
-#endif
-#ifdef FAKE_DEFAULT_SIGNAL_HANDLERS
-static int sig_defaulting[SIG_SIZE];
-#endif
-
 #ifndef PERL_MICRO
 #ifdef HAS_SIGPROCMASK
 static void
@@ -1137,10 +1121,10 @@ Perl_magic_getsig(pTHX_ SV *sv, MAGIC *mg)
     	    Sighandler_t sigstate;
     	    sigstate = rsignal_state(i);
 #ifdef FAKE_PERSISTENT_SIGNAL_HANDLERS
-    	    if (sig_handlers_initted && sig_ignoring[i]) sigstate = SIG_IGN;
+    	    if (PL_sig_handlers_initted && PL_sig_ignoring[i]) sigstate = SIG_IGN;
 #endif
 #ifdef FAKE_DEFAULT_SIGNAL_HANDLERS
-    	    if (sig_handlers_initted && sig_defaulting[i]) sigstate = SIG_DFL;
+    	    if (PL_sig_handlers_initted && PL_sig_defaulting[i]) sigstate = SIG_DFL;
 #endif
     	    /* cache state so we don't fetch it again */
     	    if(sigstate == SIG_IGN)
@@ -1159,20 +1143,20 @@ Perl_magic_clearsig(pTHX_ SV *sv, MAGIC *mg)
     /* XXX Some of this code was copied from Perl_magic_setsig. A little
      * refactoring might be in order.
      */
-    register char *s;
+    dVAR;
     STRLEN n_a;
-    SV* to_dec;
-    s = MgPV(mg,n_a);
+    register const char *s = MgPV(mg,n_a);
+    (void)sv;
     if (*s == '_') {
-	SV** svp;
+	SV** svp = 0;
 	if (strEQ(s,"__DIE__"))
 	    svp = &PL_diehook;
 	else if (strEQ(s,"__WARN__"))
 	    svp = &PL_warnhook;
 	else
 	    Perl_croak(aTHX_ "No such hook: %s", s);
-	if (*svp) {
-	    to_dec = *svp;
+	if (svp && *svp) {
+            SV *to_dec = *svp;
 	    *svp = 0;
     	    SvREFCNT_dec(to_dec);
 	}
@@ -1196,10 +1180,10 @@ Perl_magic_clearsig(pTHX_ SV *sv, MAGIC *mg)
 #endif
 	    PERL_ASYNC_CHECK();
 #if defined(FAKE_PERSISTENT_SIGNAL_HANDLERS) || defined(FAKE_DEFAULT_SIGNAL_HANDLERS)
-	    if (!sig_handlers_initted) Perl_csighandler_init();
+	    if (!PL_sig_handlers_initted) Perl_csighandler_init();
 #endif
 #ifdef FAKE_DEFAULT_SIGNAL_HANDLERS
-	    sig_defaulting[i] = 1;
+	    PL_sig_defaulting[i] = 1;
 	    (void)rsignal(i, PL_csighandlerp);
 #else
 	    (void)rsignal(i, SIG_DFL);
@@ -1209,7 +1193,7 @@ Perl_magic_clearsig(pTHX_ SV *sv, MAGIC *mg)
     		PL_psig_name[i]=0;
     	    }
     	    if(PL_psig_ptr[i]) {
-		to_dec=PL_psig_ptr[i];
+                SV *to_dec=PL_psig_ptr[i];
     		PL_psig_ptr[i]=0;
 		LEAVE;
     		SvREFCNT_dec(to_dec);
@@ -1221,8 +1205,8 @@ Perl_magic_clearsig(pTHX_ SV *sv, MAGIC *mg)
     return 0;
 }
 
-void
-Perl_raise_signal(pTHX_ int sig)
+static void
+S_raise_signal(pTHX_ int sig)
 {
     /* Set a flag to say this signal is pending */
     PL_psig_pend[sig]++;
@@ -1240,10 +1224,10 @@ Perl_csighandler(int sig)
 #endif
 #ifdef FAKE_PERSISTENT_SIGNAL_HANDLERS
     (void) rsignal(sig, PL_csighandlerp);
-    if (sig_ignoring[sig]) return;
+    if (PL_sig_ignoring[sig]) return;
 #endif
 #ifdef FAKE_DEFAULT_SIGNAL_HANDLERS
-    if (sig_defaulting[sig])
+    if (PL_sig_defaulting[sig])
 #ifdef KILL_BY_SIGPRC
             exit((Perl_sig_to_vmscondition(sig)&STS$M_COND_ID)|STS$K_SEVERE|STS$M_INHIB_MSG);
 #else
@@ -1255,7 +1239,7 @@ Perl_csighandler(int sig)
 	 * with risk we may be in malloc() etc. */
 	(*PL_sighandlerp)(sig);
    else
-	Perl_raise_signal(aTHX_ sig);
+	S_raise_signal(aTHX_ sig);
 }
 
 #if defined(FAKE_PERSISTENT_SIGNAL_HANDLERS) || defined(FAKE_DEFAULT_SIGNAL_HANDLERS)
@@ -1263,19 +1247,19 @@ void
 Perl_csighandler_init(void)
 {
     int sig;
-    if (sig_handlers_initted) return;
+    if (PL_sig_handlers_initted) return;
 
     for (sig = 1; sig < SIG_SIZE; sig++) {
 #ifdef FAKE_DEFAULT_SIGNAL_HANDLERS
         dTHX;
-        sig_defaulting[sig] = 1;
+        PL_sig_defaulting[sig] = 1;
         (void) rsignal(sig, PL_csighandlerp);
 #endif
 #ifdef FAKE_PERSISTENT_SIGNAL_HANDLERS
-        sig_ignoring[sig] = 0;
+        PL_sig_ignoring[sig] = 0;
 #endif
     }
-    sig_handlers_initted = 1;
+    PL_sig_handlers_initted = 1;
 }
 #endif
 
@@ -1298,7 +1282,7 @@ Perl_despatch_signals(pTHX)
 int
 Perl_magic_setsig(pTHX_ SV *sv, MAGIC *mg)
 {
-    register char *s;
+    dVAR;
     I32 i;
     SV** svp = 0;
     /* Need to be careful with SvREFCNT_dec(), because that can have side
@@ -1312,7 +1296,7 @@ Perl_magic_setsig(pTHX_ SV *sv, MAGIC *mg)
     SV* save_sv;
 #endif
 
-    s = MgPV(mg,len);
+    register const char *s = MgPV(mg,len);
     if (*s == '_') {
 	if (strEQ(s,"__DIE__"))
 	    svp = &PL_diehook;
@@ -1345,13 +1329,13 @@ Perl_magic_setsig(pTHX_ SV *sv, MAGIC *mg)
 #endif
 	PERL_ASYNC_CHECK();
 #if defined(FAKE_PERSISTENT_SIGNAL_HANDLERS) || defined(FAKE_DEFAULT_SIGNAL_HANDLERS)
-	if (!sig_handlers_initted) Perl_csighandler_init();
+	if (!PL_sig_handlers_initted) Perl_csighandler_init();
 #endif
 #ifdef FAKE_PERSISTENT_SIGNAL_HANDLERS
-	sig_ignoring[i] = 0;
+	PL_sig_ignoring[i] = 0;
 #endif
 #ifdef FAKE_DEFAULT_SIGNAL_HANDLERS
-	sig_defaulting[i] = 0;
+	PL_sig_defaulting[i] = 0;
 #endif
 	SvREFCNT_dec(PL_psig_name[i]);
 	to_dec = PL_psig_ptr[i];
@@ -1377,7 +1361,7 @@ Perl_magic_setsig(pTHX_ SV *sv, MAGIC *mg)
     if (strEQ(s,"IGNORE")) {
 	if (i) {
 #ifdef FAKE_PERSISTENT_SIGNAL_HANDLERS
-	    sig_ignoring[i] = 1;
+	    PL_sig_ignoring[i] = 1;
 	    (void)rsignal(i, PL_csighandlerp);
 #else
 	    (void)rsignal(i, SIG_IGN);
@@ -1388,7 +1372,7 @@ Perl_magic_setsig(pTHX_ SV *sv, MAGIC *mg)
 	if (i)
 #ifdef FAKE_DEFAULT_SIGNAL_HANDLERS
 	  {
-	    sig_defaulting[i] = 1;
+	    PL_sig_defaulting[i] = 1;
 	    (void)rsignal(i, PL_csighandlerp);
 	  }
 #else
@@ -1421,6 +1405,8 @@ Perl_magic_setsig(pTHX_ SV *sv, MAGIC *mg)
 int
 Perl_magic_setisa(pTHX_ SV *sv, MAGIC *mg)
 {
+    (void)sv;
+    (void)mg;
     PL_sub_generation++;
     return 0;
 }
@@ -1428,6 +1414,8 @@ Perl_magic_setisa(pTHX_ SV *sv, MAGIC *mg)
 int
 Perl_magic_setamagic(pTHX_ SV *sv, MAGIC *mg)
 {
+    (void)sv;
+    (void)mg;
     /* HV_badAMAGIC_on(Sv_STASH(sv)); */
     PL_amagic_generation++;
 
@@ -1437,8 +1425,9 @@ Perl_magic_setamagic(pTHX_ SV *sv, MAGIC *mg)
 int
 Perl_magic_getnkeys(pTHX_ SV *sv, MAGIC *mg)
 {
-    HV *hv = (HV*)LvTARG(sv);
+    HV * const hv = (HV*)LvTARG(sv);
     I32 i = 0;
+    (void)mg;
 
     if (hv) {
          (void) hv_iterinit(hv);
@@ -1457,6 +1446,7 @@ Perl_magic_getnkeys(pTHX_ SV *sv, MAGIC *mg)
 int
 Perl_magic_setnkeys(pTHX_ SV *sv, MAGIC *mg)
 {
+    (void)mg;
     if (LvTARG(sv)) {
 	hv_ksplit((HV*)LvTARG(sv), SvIV(sv));
     }
@@ -1465,7 +1455,7 @@ Perl_magic_setnkeys(pTHX_ SV *sv, MAGIC *mg)
 
 /* caller is responsible for stack switching/cleanup */
 STATIC int
-S_magic_methcall(pTHX_ SV *sv, MAGIC *mg, char *meth, I32 flags, int n, SV *val)
+S_magic_methcall(pTHX_ SV *sv, const MAGIC *mg, const char *meth, I32 flags, int n, SV *val)
 {
     dSP;
 
@@ -1492,9 +1482,9 @@ S_magic_methcall(pTHX_ SV *sv, MAGIC *mg, char *meth, I32 flags, int n, SV *val)
 }
 
 STATIC int
-S_magic_methpack(pTHX_ SV *sv, MAGIC *mg, char *meth)
+S_magic_methpack(pTHX_ SV *sv, const MAGIC *mg, const char *meth)
 {
-    dSP;
+    dVAR; dSP;
 
     ENTER;
     SAVETMPS;
@@ -1522,7 +1512,7 @@ Perl_magic_getpack(pTHX_ SV *sv, MAGIC *mg)
 int
 Perl_magic_setpack(pTHX_ SV *sv, MAGIC *mg)
 {
-    dSP;
+    dVAR; dSP;
     ENTER;
     PUSHSTACKi(PERLSI_MAGIC);
     magic_methcall(sv, mg, "STORE", G_SCALAR|G_DISCARD, 3, sv);
@@ -1541,7 +1531,7 @@ Perl_magic_clearpack(pTHX_ SV *sv, MAGIC *mg)
 U32
 Perl_magic_sizepack(pTHX_ SV *sv, MAGIC *mg)
 {
-    dSP;
+    dVAR; dSP;
     U32 retval = 0;
 
     ENTER;
@@ -1560,7 +1550,7 @@ Perl_magic_sizepack(pTHX_ SV *sv, MAGIC *mg)
 int
 Perl_magic_wipepack(pTHX_ SV *sv, MAGIC *mg)
 {
-    dSP;
+    dVAR; dSP;
 
     ENTER;
     PUSHSTACKi(PERLSI_MAGIC);
@@ -1577,8 +1567,8 @@ Perl_magic_wipepack(pTHX_ SV *sv, MAGIC *mg)
 int
 Perl_magic_nextpack(pTHX_ SV *sv, MAGIC *mg, SV *key)
 {
-    dSP;
-    const char *meth = SvOK(key) ? "NEXTKEY" : "FIRSTKEY";
+    dVAR; dSP;
+    const char * const meth = SvOK(key) ? "NEXTKEY" : "FIRSTKEY";
 
     ENTER;
     SAVETMPS;
@@ -1608,7 +1598,7 @@ Perl_magic_existspack(pTHX_ SV *sv, MAGIC *mg)
 SV *
 Perl_magic_scalarpack(pTHX_ HV *hv, MAGIC *mg)
 {
-    dSP;
+    dVAR; dSP;
     SV *retval = &PL_sv_undef;
     SV *tied = SvTIED_obj((SV*)hv, mg);
     HV *pkg = SvSTASH((SV*)SvRV(tied));
@@ -1751,6 +1741,7 @@ Perl_magic_setpos(pTHX_ SV *sv, MAGIC *mg)
 int
 Perl_magic_getglob(pTHX_ SV *sv, MAGIC *mg)
 {
+    (void)mg;
     if (SvFAKE(sv)) {			/* FAKE globs can get coerced */
 	SvFAKE_off(sv);
 	gv_efullname3(sv,((GV*)sv), "*");
@@ -1765,6 +1756,7 @@ int
 Perl_magic_setglob(pTHX_ SV *sv, MAGIC *mg)
 {
     GV* gv;
+    (void)mg;
  
     if (!SvOK(sv))
 	return 0;
@@ -1781,10 +1773,11 @@ int
 Perl_magic_getsubstr(pTHX_ SV *sv, MAGIC *mg)
 {
     STRLEN len;
-    SV *lsv = LvTARG(sv);
-    char *tmps = SvPV(lsv,len);
+    SV * const lsv = LvTARG(sv);
+    const char * const tmps = SvPV(lsv,len);
     I32 offs = LvTARGOFF(sv);
     I32 rem = LvTARGLEN(sv);
+    (void)mg;
 
     if (SvUTF8(lsv))
 	sv_pos_u2b(lsv, &offs, &rem);
@@ -1803,9 +1796,10 @@ Perl_magic_setsubstr(pTHX_ SV *sv, MAGIC *mg)
 {
     STRLEN len;
     char *tmps = SvPV(sv, len);
-    SV *lsv = LvTARG(sv);
+    SV * const lsv = LvTARG(sv);
     I32 lvoff = LvTARGOFF(sv);
     I32 lvlen = LvTARGLEN(sv);
+    (void)mg;
 
     if (DO_UTF8(sv)) {
 	sv_utf8_upgrade(lsv);
@@ -1841,6 +1835,7 @@ Perl_magic_gettaint(pTHX_ SV *sv, MAGIC *mg)
 int
 Perl_magic_settaint(pTHX_ SV *sv, MAGIC *mg)
 {
+    (void)sv;
     if (PL_localizing) {
 	if (PL_localizing == 1)
 	    mg->mg_len <<= 1;
@@ -1857,7 +1852,8 @@ Perl_magic_settaint(pTHX_ SV *sv, MAGIC *mg)
 int
 Perl_magic_getvec(pTHX_ SV *sv, MAGIC *mg)
 {
-    SV *lsv = LvTARG(sv);
+    SV * const lsv = LvTARG(sv);
+    (void)mg;
 
     if (!lsv) {
 	SvOK_off(sv);
@@ -1871,6 +1867,7 @@ Perl_magic_getvec(pTHX_ SV *sv, MAGIC *mg)
 int
 Perl_magic_setvec(pTHX_ SV *sv, MAGIC *mg)
 {
+    (void)mg;
     do_vecset(sv);	/* XXX slurp this routine */
     return 0;
 }
@@ -1910,6 +1907,7 @@ Perl_magic_getdefelem(pTHX_ SV *sv, MAGIC *mg)
 int
 Perl_magic_setdefelem(pTHX_ SV *sv, MAGIC *mg)
 {
+    (void)mg;
     if (LvTARGLEN(sv))
 	vivify_defelem(sv);
     if (LvTARG(sv)) {
@@ -1961,12 +1959,14 @@ Perl_magic_killbackrefs(pTHX_ SV *sv, MAGIC *mg)
     AV *av = (AV*)mg->mg_obj;
     SV **svp = AvARRAY(av);
     I32 i = AvFILLp(av);
+    (void)sv;
+
     while (i >= 0) {
 	if (svp[i]) {
 	    if (!SvWEAKREF(svp[i]))
 		Perl_croak(aTHX_ "panic: magic_killbackrefs");
 	    /* XXX Should we check that it hasn't changed? */
-	    SvRV(svp[i]) = 0;
+	    SvRV_set(svp[i], 0);
 	    SvOK_off(svp[i]);
 	    SvWEAKREF_off(svp[i]);
 	    svp[i] = Nullsv;
@@ -1988,6 +1988,7 @@ Perl_magic_setmglob(pTHX_ SV *sv, MAGIC *mg)
 int
 Perl_magic_setbm(pTHX_ SV *sv, MAGIC *mg)
 {
+    (void)mg;
     sv_unmagic(sv, PERL_MAGIC_bm);
     SvVALID_off(sv);
     return 0;
@@ -1996,6 +1997,7 @@ Perl_magic_setbm(pTHX_ SV *sv, MAGIC *mg)
 int
 Perl_magic_setfm(pTHX_ SV *sv, MAGIC *mg)
 {
+    (void)mg;
     sv_unmagic(sv, PERL_MAGIC_fm);
     SvCOMPILED_off(sv);
     return 0;
@@ -2004,7 +2006,7 @@ Perl_magic_setfm(pTHX_ SV *sv, MAGIC *mg)
 int
 Perl_magic_setuvar(pTHX_ SV *sv, MAGIC *mg)
 {
-    struct ufuncs *uf = (struct ufuncs *)mg->mg_ptr;
+    const struct ufuncs * const uf = (struct ufuncs *)mg->mg_ptr;
 
     if (uf && uf->uf_set)
 	(*uf->uf_set)(aTHX_ uf->uf_index, sv);
@@ -2014,6 +2016,7 @@ Perl_magic_setuvar(pTHX_ SV *sv, MAGIC *mg)
 int
 Perl_magic_setregexp(pTHX_ SV *sv, MAGIC *mg)
 {
+    (void)mg;
     sv_unmagic(sv, PERL_MAGIC_qr);
     return 0;
 }
@@ -2023,6 +2026,7 @@ Perl_magic_freeregexp(pTHX_ SV *sv, MAGIC *mg)
 {
     regexp *re = (regexp *)mg->mg_obj;
     ReREFCNT_dec(re);
+    (void)sv;
     return 0;
 }
 
@@ -2034,6 +2038,7 @@ Perl_magic_setcollxfrm(pTHX_ SV *sv, MAGIC *mg)
      * RenE<eacute> Descartes said "I think not."
      * and vanished with a faint plop.
      */
+    (void)sv;
     if (mg->mg_ptr) {
 	Safefree(mg->mg_ptr);
 	mg->mg_ptr = NULL;
@@ -2047,6 +2052,7 @@ Perl_magic_setcollxfrm(pTHX_ SV *sv, MAGIC *mg)
 int
 Perl_magic_setutf8(pTHX_ SV *sv, MAGIC *mg)
 {
+    (void)sv;
     Safefree(mg->mg_ptr);	/* The mg_ptr holds the pos cache. */
     mg->mg_ptr = 0;
     mg->mg_len = -1;		/* The mg_len holds the len cache. */
@@ -2056,7 +2062,7 @@ Perl_magic_setutf8(pTHX_ SV *sv, MAGIC *mg)
 int
 Perl_magic_set(pTHX_ SV *sv, MAGIC *mg)
 {
-    register char *s;
+    register const char *s;
     I32 i;
     STRLEN len;
     switch (*mg->mg_ptr) {
@@ -2118,7 +2124,7 @@ Perl_magic_set(pTHX_ SV *sv, MAGIC *mg)
 	if (PL_inplace)
 	    Safefree(PL_inplace);
 	if (SvOK(sv))
-	    PL_inplace = savepv(SvPV(sv,len));
+	    PL_inplace = savesvpv(sv);
 	else
 	    PL_inplace = Nullch;
 	break;
@@ -2130,7 +2136,7 @@ Perl_magic_set(pTHX_ SV *sv, MAGIC *mg)
 	    }
 	    if (SvOK(sv)) {
 		TAINT_PROPER("assigning to $^O");
-		PL_osname = savepv(SvPV(sv,len));
+		PL_osname = savesvpv(sv);
 	    }
 	}
 	else if (strEQ(mg->mg_ptr, "\017PEN")) {
@@ -2142,8 +2148,7 @@ Perl_magic_set(pTHX_ SV *sv, MAGIC *mg)
 	break;
     case '\020':	/* ^P */
 	PL_perldb = SvIOK(sv) ? SvIVX(sv) : sv_2iv(sv);
-	if ((PERLDB_SUB || PERLDB_LINE || PERLDB_SUBLINE || PERLDB_ASSERTION)
-		&& !PL_DBsingle)
+	if (PL_perldb && !PL_DBsingle)
 	    init_debugger();
 	break;
     case '\024':	/* ^T */
@@ -2172,7 +2177,7 @@ Perl_magic_set(pTHX_ SV *sv, MAGIC *mg)
 		    STRLEN len, i;
 		    int accumulate = 0 ;
 		    int any_fatals = 0 ;
-		    char * ptr = (char*)SvPV(sv, len) ;
+		    const char * const ptr = (char*)SvPV(sv, len) ;
 		    for (i = 0 ; i < len ; ++i) {
 		        accumulate |= ptr[i] ;
 		        any_fatals |= (ptr[i] & 0xAA) ;
@@ -2206,12 +2211,12 @@ Perl_magic_set(pTHX_ SV *sv, MAGIC *mg)
 	break;
     case '^':
 	Safefree(IoTOP_NAME(GvIOp(PL_defoutgv)));
-	IoTOP_NAME(GvIOp(PL_defoutgv)) = s = savepv(SvPV(sv,len));
+	s = IoTOP_NAME(GvIOp(PL_defoutgv)) = savesvpv(sv);
 	IoTOP_GV(GvIOp(PL_defoutgv)) = gv_fetchsv(sv,TRUE, SVt_PVIO);
 	break;
     case '~':
 	Safefree(IoFMT_NAME(GvIOp(PL_defoutgv)));
-	IoFMT_NAME(GvIOp(PL_defoutgv)) = s = savepv(SvPV(sv,len));
+	s = IoFMT_NAME(GvIOp(PL_defoutgv)) = savesvpv(sv);
 	IoFMT_GV(GvIOp(PL_defoutgv)) = gv_fetchsv(sv,TRUE, SVt_PVIO);
 	break;
     case '=':
@@ -2269,7 +2274,7 @@ Perl_magic_set(pTHX_ SV *sv, MAGIC *mg)
     case '#':
 	if (PL_ofmt)
 	    Safefree(PL_ofmt);
-	PL_ofmt = savepv(SvPV(sv,len));
+	PL_ofmt = savesvpv(sv);
 	break;
     case '[':
 	PL_compiling.cop_arybase = SvIOK(sv) ? SvIVX(sv) : sv_2iv(sv);
@@ -2389,7 +2394,7 @@ Perl_magic_set(pTHX_ SV *sv, MAGIC *mg)
     case ')':
 #ifdef HAS_SETGROUPS
 	{
-	    char *p = SvPV(sv, len);
+	    const char *p = SvPV(sv, len);
 	    Groups_t gary[NGROUPS];
 
 	    while (isSPACE(*p))
@@ -2469,7 +2474,7 @@ Perl_magic_set(pTHX_ SV *sv, MAGIC *mg)
 	{
 	     union pstun un;
 	     s = SvPV(sv, len);
-	     un.pst_command = s;
+	     un.pst_command = (char *)s;
 	     pstat(PSTAT_SETCMD, un, len, 0, 0);
 	}
 #endif
@@ -2503,13 +2508,13 @@ Perl_magic_set(pTHX_ SV *sv, MAGIC *mg)
 }
 
 I32
-Perl_whichsig(pTHX_ char *sig)
+Perl_whichsig(pTHX_ const char *sig)
 {
-    register char **sigv;
+    register char* const* sigv;
 
-    for (sigv = PL_sig_name; *sigv; sigv++)
+    for (sigv = (char* const*)PL_sig_name; *sigv; sigv++)
 	if (strEQ(sig,*sigv))
-	    return PL_sig_num[sigv - PL_sig_name];
+	    return PL_sig_num[sigv - (char* const*)PL_sig_name];
 #ifdef SIGCLD
     if (strEQ(sig,"CHLD"))
 	return SIGCLD;
@@ -2521,10 +2526,6 @@ Perl_whichsig(pTHX_ char *sig)
     return -1;
 }
 
-#if !defined(PERL_IMPLICIT_CONTEXT)
-static SV* sig_sv;
-#endif
-
 Signal_t
 Perl_sighandler(int sig)
 {
@@ -2584,7 +2585,7 @@ Perl_sighandler(int sig)
     	sv = SvREFCNT_inc(PL_psig_name[sig]);
 	flags |= 64;
 #if !defined(PERL_IMPLICIT_CONTEXT)
-	sig_sv = sv;
+	PL_sig_sv = sv;
 #endif
     } else {
 	sv = sv_newmortal();
@@ -2616,7 +2617,7 @@ Perl_sighandler(int sig)
 	(void)rsignal(sig, PL_csighandlerp);
 #endif
 #endif /* !PERL_MICRO */
-	Perl_die(aTHX_ Nullformat);
+	DieNull;
     }
 cleanup:
     if (flags & 1)
@@ -2636,7 +2637,7 @@ cleanup:
 
 
 static void
-restore_magic(pTHX_ void *p)
+restore_magic(pTHX_ const void *p)
 {
     MGS* mgs = SSPTR(PTR2IV(p), MGS*);
     SV* sv = mgs->mgs_sv;
@@ -2684,16 +2685,17 @@ restore_magic(pTHX_ void *p)
 }
 
 static void
-unwind_handler_stack(pTHX_ void *p)
+unwind_handler_stack(pTHX_ const void *p)
 {
-    U32 flags = *(U32*)p;
+    dVAR;
+    const U32 flags = *(const U32*)p;
 
     if (flags & 1)
 	PL_savestack_ix -= 5; /* Unprotect save in progress. */
     /* cxstack_ix-- Not needed, die already unwound it. */
 #if !defined(PERL_IMPLICIT_CONTEXT)
     if (flags & 64)
-	SvREFCNT_dec(sig_sv);
+	SvREFCNT_dec(PL_sig_sv);
 #endif
 }