fixes for most warnings identified by gcc -Wall

p4raw-id: //depot/perl@5540

31 files changed, 197 insertions, 228 deletions

diff --git a/av.c b/av.c
index 1253c1261f..819887e2ad 100644
--- a/av.c
+++ b/av.c
@@ -60,7 +60,7 @@ Perl_av_extend(pTHX_ AV *av, I32 key)
 {
     dTHR;			/* only necessary if we have to extend stack */
     MAGIC *mg;
-    if (mg = SvTIED_mg((SV*)av, 'P')) {
+    if ((mg = SvTIED_mg((SV*)av, 'P'))) {
 	dSP;
 	ENTER;
 	SAVETMPS;
@@ -241,8 +241,6 @@ SV**
 Perl_av_store(pTHX_ register AV *av, I32 key, SV *val)
 {
     SV** ary;
-    U32  fill;
-
 
     if (!av)
 	return 0;
@@ -419,7 +417,7 @@ Perl_av_clear(pTHX_ register AV *av)
 	    ary[key] = &PL_sv_undef;
 	}
     }
-    if (key = AvARRAY(av) - AvALLOC(av)) {
+    if ((key = AvARRAY(av) - AvALLOC(av))) {
 	AvMAX(av) += key;
 	SvPVX(av) = (char*)AvALLOC(av);
     }
@@ -481,7 +479,7 @@ Perl_av_push(pTHX_ register AV *av, SV *val)
     if (SvREADONLY(av))
 	Perl_croak(aTHX_ PL_no_modify);
 
-    if (mg = SvTIED_mg((SV*)av, 'P')) {
+    if ((mg = SvTIED_mg((SV*)av, 'P'))) {
 	dSP;
 	PUSHSTACKi(PERLSI_MAGIC);
 	PUSHMARK(SP);
@@ -517,7 +515,7 @@ Perl_av_pop(pTHX_ register AV *av)
 	return &PL_sv_undef;
     if (SvREADONLY(av))
 	Perl_croak(aTHX_ PL_no_modify);
-    if (mg = SvTIED_mg((SV*)av, 'P')) {
+    if ((mg = SvTIED_mg((SV*)av, 'P'))) {
 	dSP;    
 	PUSHSTACKi(PERLSI_MAGIC);
 	PUSHMARK(SP);
@@ -562,7 +560,7 @@ Perl_av_unshift(pTHX_ register AV *av, register I32 num)
     if (SvREADONLY(av))
 	Perl_croak(aTHX_ PL_no_modify);
 
-    if (mg = SvTIED_mg((SV*)av, 'P')) {
+    if ((mg = SvTIED_mg((SV*)av, 'P'))) {
 	dSP;
 	PUSHSTACKi(PERLSI_MAGIC);
 	PUSHMARK(SP);
@@ -621,7 +619,7 @@ Perl_av_shift(pTHX_ register AV *av)
 	return &PL_sv_undef;
     if (SvREADONLY(av))
 	Perl_croak(aTHX_ PL_no_modify);
-    if (mg = SvTIED_mg((SV*)av, 'P')) {
+    if ((mg = SvTIED_mg((SV*)av, 'P'))) {
 	dSP;
 	PUSHSTACKi(PERLSI_MAGIC);
 	PUSHMARK(SP);
@@ -671,7 +669,7 @@ Perl_av_fill(pTHX_ register AV *av, I32 fill)
 	Perl_croak(aTHX_ "panic: null array");
     if (fill < 0)
 	fill = -1;
-    if (mg = SvTIED_mg((SV*)av, 'P')) {
+    if ((mg = SvTIED_mg((SV*)av, 'P'))) {
 	dSP;            
 	ENTER;
 	SAVETMPS;
diff --git a/cop.h b/cop.h
index cfa6f4851c..2f1f676c0c 100644
--- a/cop.h
+++ b/cop.h
@@ -199,12 +199,12 @@ struct block_loop {
 	    : &GvSV((GV*)(c)->blk_loop.iterdata))			\
 	 : (SV**)NULL)
 #  define CX_ITERDATA_SET(cx,idata)					\
-	if (cx->blk_loop.iterdata = (idata))				\
+	if ((cx->blk_loop.iterdata = (idata)))				\
 	    cx->blk_loop.itersave = SvREFCNT_inc(*CxITERVAR(cx));
 #else
 #  define CxITERVAR(c)		((c)->blk_loop.itervar)
 #  define CX_ITERDATA_SET(cx,ivar)					\
-	if (cx->blk_loop.itervar = (SV**)(ivar))			\
+	if ((cx->blk_loop.itervar = (SV**)(ivar)))			\
 	    cx->blk_loop.itersave = SvREFCNT_inc(*CxITERVAR(cx));
 #endif
 
diff --git a/deb.c b/deb.c
index 0928c01a9a..441487f88e 100644
--- a/deb.c
+++ b/deb.c
@@ -46,7 +46,6 @@ Perl_vdeb(pTHX_ const char *pat, va_list *args)
 {
 #ifdef DEBUGGING
     dTHR;
-    register I32 i;
     char* file = CopFILE(PL_curcop);
 
 #ifdef USE_THREADS
diff --git a/doop.c b/doop.c
index 4f536f0059..e92a7ca776 100644
--- a/doop.c
+++ b/doop.c
@@ -924,7 +924,7 @@ Perl_do_chop(pTHX_ register SV *astr, register SV *sv)
 	HE* entry;
         (void)hv_iterinit(hv);
         /*SUPPRESS 560*/
-        while (entry = hv_iternext(hv))
+        while ((entry = hv_iternext(hv)))
             do_chop(astr,hv_iterval(hv,entry));
         return;
     }
@@ -994,7 +994,7 @@ Perl_do_chomp(pTHX_ register SV *sv)
 	HE* entry;
         (void)hv_iterinit(hv);
         /*SUPPRESS 560*/
-        while (entry = hv_iternext(hv))
+        while ((entry = hv_iternext(hv)))
             count += do_chomp(hv_iterval(hv,entry));
         return count;
     }
@@ -1290,7 +1290,7 @@ Perl_do_kv(pTHX)
     EXTEND(SP, HvKEYS(keys) * (dokeys + dovalues));
 
     PUTBACK;	/* hv_iternext and hv_iterval might clobber stack_sp */
-    while (entry = hv_iternext(keys)) {
+    while ((entry = hv_iternext(keys))) {
 	SPAGAIN;
 	if (dokeys)
 	    XPUSHs(hv_iterkeysv(entry));	/* won't clobber stack_sp */
diff --git a/dump.c b/dump.c
index 189d6721f1..92a26e8a11 100644
--- a/dump.c
+++ b/dump.c
@@ -370,7 +370,6 @@ void
 Perl_do_op_dump(pTHX_ I32 level, PerlIO *file, OP *o)
 {
     dTHR;
-    STRLEN n_a;
     Perl_dump_indent(aTHX_ level, file, "{\n");
     level++;
     if (o->op_seq)
@@ -524,6 +523,7 @@ Perl_do_op_dump(pTHX_ I32 level, PerlIO *file, OP *o)
 #else
 	if (cSVOPo->op_sv) {
 	    SV *tmpsv = NEWSV(0,0);
+	    STRLEN n_a;
 	    ENTER;
 	    SAVEFREESV(tmpsv);
 	    gv_fullname3(tmpsv, (GV*)cSVOPo->op_sv, Nullch);
@@ -1032,7 +1032,7 @@ Perl_do_sv_dump(pTHX_ I32 level, PerlIO *file, SV *sv, I32 nest, I32 maxnest, bo
 	    for (i = max; i > 0; i--) { /* Precision: count down. */
 		sum += freq[i] * i * i;
             }
-	    while (keys = keys >> 1)
+	    while ((keys = keys >> 1))
 		pow2 = pow2 << 1;
 	    /* Approximate by Poisson distribution */
 	    theoret = HvKEYS(sv);
diff --git a/embed.h b/embed.h
index e6bafffe79..0906d8761e 100644
--- a/embed.h
+++ b/embed.h
@@ -1094,8 +1094,10 @@
 #define ao			S_ao
 #define depcom			S_depcom
 #define incl_perldb		S_incl_perldb
+#if 0
 #define utf16_textfilter	S_utf16_textfilter
 #define utf16rev_textfilter	S_utf16rev_textfilter
+#endif
 #  if defined(CRIPPLED_CC)
 #define uni			S_uni
 #  endif
@@ -2521,8 +2523,10 @@
 #define ao(a)			S_ao(aTHX_ a)
 #define depcom()		S_depcom(aTHX)
 #define incl_perldb()		S_incl_perldb(aTHX)
+#if 0
 #define utf16_textfilter(a,b,c)	S_utf16_textfilter(aTHX_ a,b,c)
 #define utf16rev_textfilter(a,b,c)	S_utf16rev_textfilter(aTHX_ a,b,c)
+#endif
 #  if defined(CRIPPLED_CC)
 #define uni(a,b)		S_uni(aTHX_ a,b)
 #  endif
@@ -4904,10 +4908,12 @@
 #define depcom			S_depcom
 #define S_incl_perldb		CPerlObj::S_incl_perldb
 #define incl_perldb		S_incl_perldb
+#if 0
 #define S_utf16_textfilter	CPerlObj::S_utf16_textfilter
 #define utf16_textfilter	S_utf16_textfilter
 #define S_utf16rev_textfilter	CPerlObj::S_utf16rev_textfilter
 #define utf16rev_textfilter	S_utf16rev_textfilter
+#endif
 #  if defined(CRIPPLED_CC)
 #define S_uni			CPerlObj::S_uni
 #define uni			S_uni
diff --git a/embed.pl b/embed.pl
index 0c568e37f1..56b121d3f8 100755
--- a/embed.pl
+++ b/embed.pl
@@ -2453,8 +2453,10 @@ s	|SV*	|new_constant	|char *s|STRLEN len|const char *key|SV *sv \
 s	|int	|ao		|int toketype
 s	|void	|depcom
 s	|char*	|incl_perldb
+#if 0
 s	|I32	|utf16_textfilter|int idx|SV *sv|int maxlen
 s	|I32	|utf16rev_textfilter|int idx|SV *sv|int maxlen
+#endif
 #  if defined(CRIPPLED_CC)
 s	|int	|uni		|I32 f|char *s
 #  endif
diff --git a/gv.c b/gv.c
index 5c50a1c3b6..587d3dc581 100644
--- a/gv.c
+++ b/gv.c
@@ -199,7 +199,7 @@ Perl_gv_fetchmeth(pTHX_ HV *stash, const char *name, STRLEN len, I32 level)
 	topgv = *gvp;
 	if (SvTYPE(topgv) != SVt_PVGV)
 	    gv_init(topgv, stash, name, len, TRUE);
-	if (cv = GvCV(topgv)) {
+	if ((cv = GvCV(topgv))) {
 	    /* If genuine method or valid cache entry, use it */
 	    if (!GvCVGEN(topgv) || GvCVGEN(topgv) == PL_sub_generation)
 		return topgv;
@@ -265,9 +265,10 @@ Perl_gv_fetchmeth(pTHX_ HV *stash, const char *name, STRLEN len, I32 level)
     if (level == 0 || level == -1) {
 	HV* lastchance;
 
-	if (lastchance = gv_stashpvn("UNIVERSAL", 9, FALSE)) {
-	    if (gv = gv_fetchmeth(lastchance, name, len,
-				  (level >= 0) ? level + 1 : level - 1)) {
+	if ((lastchance = gv_stashpvn("UNIVERSAL", 9, FALSE))) {
+	    if ((gv = gv_fetchmeth(lastchance, name, len,
+				  (level >= 0) ? level + 1 : level - 1)))
+	    {
 	  gotcha:
 		/*
 		 * Cache method in topgv if:
@@ -279,7 +280,7 @@ Perl_gv_fetchmeth(pTHX_ HV *stash, const char *name, STRLEN len, I32 level)
 		    (cv = GvCV(gv)) &&
 		    (CvROOT(cv) || CvXSUB(cv)))
 		{
-		    if (cv = GvCV(topgv))
+		    if ((cv = GvCV(topgv)))
 			SvREFCNT_dec(cv);
 		    GvCV(topgv) = (CV*)SvREFCNT_inc(GvCV(gv));
 		    GvCVGEN(topgv) = PL_sub_generation;
@@ -621,9 +622,9 @@ Perl_gv_fetchpv(pTHX_ const char *nambeg, I32 add, I32 sv_type)
 		    {
 			stash = 0;
 		    }
-		    else if (sv_type == SVt_PV   && !GvIMPORTED_SV(*gvp) ||
-			     sv_type == SVt_PVAV && !GvIMPORTED_AV(*gvp) ||
-			     sv_type == SVt_PVHV && !GvIMPORTED_HV(*gvp) )
+		    else if ((sv_type == SVt_PV   && !GvIMPORTED_SV(*gvp)) ||
+			     (sv_type == SVt_PVAV && !GvIMPORTED_AV(*gvp)) ||
+			     (sv_type == SVt_PVHV && !GvIMPORTED_HV(*gvp)) )
 		    {
 			Perl_warn(aTHX_ "Variable \"%c%s\" is not imported",
 			    sv_type == SVt_PVAV ? '@' :
@@ -910,7 +911,7 @@ Perl_gv_fullname3(pTHX_ SV *sv, GV *gv, const char *prefix)
 {
     HV *hv = GvSTASH(gv);
     if (!hv) {
-	SvOK_off(sv);
+	(void)SvOK_off(sv);
 	return;
     }
     sv_setpv(sv, prefix ? prefix : "");
@@ -1043,7 +1044,6 @@ Perl_gp_free(pTHX_ GV *gv)
 {
     dTHR;  
     GP* gp;
-    CV* cv;
 
     if (!gv || !(gp = GvGP(gv)))
 	return;
@@ -1103,15 +1103,17 @@ register GV *gv;
 bool
 Perl_Gv_AMupdate(pTHX_ HV *stash)
 {
-  dTHR;  
-  GV** gvp;
-  HV* hv;
+  dTHR;
   GV* gv;
   CV* cv;
   MAGIC* mg=mg_find((SV*)stash,'c');
   AMT *amtp = (mg) ? (AMT*)mg->mg_ptr: (AMT *) NULL;
   AMT amt;
   STRLEN n_a;
+#ifdef OVERLOAD_VIA_HASH
+  GV** gvp;
+  HV* hv;
+#endif
 
   if (mg && amtp->was_ok_am == PL_amagic_generation
       && amtp->was_ok_sub == PL_sub_generation)
@@ -1192,18 +1194,21 @@ Perl_Gv_AMupdate(pTHX_ HV *stash)
     int i;
     const char *cp;
     SV* sv = NULL;
-    SV** svp;
 
     /* Work with "fallback" key, which we assume to be first in PL_AMG_names */
 
-    if ( cp = PL_AMG_names[0] ) {
+    if ((cp = PL_AMG_names[0])) {
 	/* Try to find via inheritance. */
 	gv = gv_fetchmeth(stash, "()", 2, -1); /* A cookie: "()". */
-	if (gv) sv = GvSV(gv);
-
-	if (!gv) goto no_table;
-	else if (SvTRUE(sv)) amt.fallback=AMGfallYES;
-	else if (SvOK(sv)) amt.fallback=AMGfallNEVER;
+	if (gv)
+	    sv = GvSV(gv);
+
+	if (!gv)
+	    goto no_table;
+	else if (SvTRUE(sv))
+	    amt.fallback=AMGfallYES;
+	else if (SvOK(sv))
+	    amt.fallback=AMGfallNEVER;
     }
 
     for (i = 1; i < NofAMmeth; i++) {
@@ -1359,7 +1364,7 @@ Perl_amagic_call(pTHX_ SV *left, SV *right, int method, int flags)
 	   }
 	   break;
 	 case neg_amg:
-	   if (cv = cvp[off=subtr_amg]) {
+	   if ((cv = cvp[off=subtr_amg])) {
 	     right = left;
 	     left = sv_2mortal(newSViv(0));
 	     lr = 1;
@@ -1527,7 +1532,7 @@ Perl_amagic_call(pTHX_ SV *left, SV *right, int method, int flags)
     PUSHs((SV*)cv);
     PUTBACK;
 
-    if (PL_op = Perl_pp_entersub(aTHX))
+    if ((PL_op = Perl_pp_entersub(aTHX)))
       CALLRUNOPS(aTHX);
     LEAVE;
     SPAGAIN;
diff --git a/hv.c b/hv.c
index fd2c2d7c6f..44d37e34d3 100644
--- a/hv.c
+++ b/hv.c
@@ -1044,7 +1044,7 @@ Perl_newHVhv(pTHX_ HV *ohv)
 	
 	/* Slow way */
 	hv_iterinit(ohv);
-	while (entry = hv_iternext(ohv)) {
+	while ((entry = hv_iternext(ohv))) {
 	    hv_store(hv, HeKEY(entry), HeKLEN(entry), 
 		     SvREFCNT_inc(HeVAL(entry)), HeHASH(entry));
 	}
@@ -1238,7 +1238,7 @@ Perl_hv_iternext(pTHX_ HV *hv)
     xhv = (XPVHV*)SvANY(hv);
     oldentry = entry = xhv->xhv_eiter;
 
-    if (mg = SvTIED_mg((SV*)hv, 'P')) {
+    if ((mg = SvTIED_mg((SV*)hv, 'P'))) {
 	SV *key = sv_newmortal();
 	if (entry) {
 	    sv_setsv(key, HeSVKEY_force(entry));
diff --git a/mg.c b/mg.c
index 904381a069..96d268bfc7 100644
--- a/mg.c
+++ b/mg.c
@@ -339,10 +339,7 @@ U32
 Perl_magic_regdata_cnt(pTHX_ SV *sv, MAGIC *mg)
 {
     dTHR;
-    register char *s;
-    register I32 i;
     register REGEXP *rx;
-    char *t;
 
     if (PL_curpm && (rx = PL_curpm->op_pmregexp)) {
 	if (mg->mg_obj)		/* @+ */
@@ -387,10 +384,8 @@ Perl_magic_len(pTHX_ SV *sv, MAGIC *mg)
 {
     dTHR;
     register I32 paren;
-    register char *s;
     register I32 i;
     register REGEXP *rx;
-    char *t;
 
     switch (*mg->mg_ptr) {
     case '1': case '2': case '3': case '4':
@@ -458,7 +453,6 @@ Perl_magic_get(pTHX_ SV *sv, MAGIC *mg)
     register char *s;
     register I32 i;
     register REGEXP *rx;
-    char *t;
 
     switch (*mg->mg_ptr) {
     case '\001':		/* ^A */
@@ -553,7 +547,7 @@ Perl_magic_get(pTHX_ SV *sv, MAGIC *mg)
 	{
 	    dTHR;
 	    if (PL_lex_state != LEX_NOTPARSING)
-		SvOK_off(sv);
+		(void)SvOK_off(sv);
 	    else if (PL_in_eval)
 		sv_setiv(sv, 1);
 	    else
@@ -756,7 +750,7 @@ Perl_magic_get(pTHX_ SV *sv, MAGIC *mg)
 		Perl_sv_catpvf(aTHX_ sv, " %"Gid_t_f, gary[i]);
 	}
 #endif
-	SvIOK_on(sv);	/* what a wonderful hack! */
+	(void)SvIOK_on(sv);	/* what a wonderful hack! */
 	break;
     case '*':
 	break;
@@ -879,7 +873,7 @@ Perl_magic_set_all_env(pTHX_ SV *sv, MAGIC *mg)
 	STRLEN n_a;
 	magic_clear_all_env(sv,mg);
 	hv_iterinit((HV*)sv);
-	while (entry = hv_iternext((HV*)sv)) {
+	while ((entry = hv_iternext((HV*)sv))) {
 	    I32 keylen;
 	    my_setenv(hv_iterkey(entry, &keylen),
 		      SvPV(hv_iterval((HV*)sv, entry), n_a));
@@ -1085,7 +1079,7 @@ Perl_magic_getnkeys(pTHX_ SV *sv, MAGIC *mg)
 	    i = HvKEYS(hv);
 	else {
 	    /*SUPPRESS 560*/
-	    while (entry = hv_iternext(hv)) {
+	    while ((entry = hv_iternext(hv))) {
 		i++;
 	    }
 	}
@@ -1420,7 +1414,7 @@ Perl_magic_gettaint(pTHX_ SV *sv, MAGIC *mg)
 {
     dTHR;
     TAINT_IF((mg->mg_len & 1) ||
-	     (mg->mg_len & 2) && mg->mg_obj == sv);	/* kludge */
+	     ((mg->mg_len & 2) && mg->mg_obj == sv));	/* kludge */
     return 0;
 }
 
@@ -1447,7 +1441,7 @@ Perl_magic_getvec(pTHX_ SV *sv, MAGIC *mg)
     SV *lsv = LvTARG(sv);
 
     if (!lsv) {
-	SvOK_off(sv);
+	(void)SvOK_off(sv);
 	return 0;
     }
 
@@ -1570,7 +1564,7 @@ Perl_magic_killbackrefs(pTHX_ SV *sv, MAGIC *mg)
 		Perl_croak(aTHX_ "panic: magic_killbackrefs");
 	    /* XXX Should we check that it hasn't changed? */
 	    SvRV(svp[i]) = 0;
-	    SvOK_off(svp[i]);
+	    (void)SvOK_off(svp[i]);
 	    SvWEAKREF_off(svp[i]);
 	    svp[i] = &PL_sv_undef;
 	}
@@ -2090,7 +2084,7 @@ Perl_sighandler(int sig)
     CV *cv = Nullcv;
     OP *myop = PL_op;
     U32 flags = 0;
-    I32 o_save_i = PL_savestack_ix, type;
+    I32 o_save_i = PL_savestack_ix;
     XPV *tXpv = PL_Xpv;
     
     if (PL_savestack_ix + 15 <= PL_savestack_max)
diff --git a/miniperlmain.c b/miniperlmain.c
index fb5cf1afe8..9bbdaf4c86 100644
--- a/miniperlmain.c
+++ b/miniperlmain.c
@@ -13,7 +13,6 @@
 
 static void xs_init (pTHX);
 static PerlInterpreter *my_perl;
-static struct perl_thread *thr;		/* XXXXXX testing */
 
 #if defined (__MINT__) || defined (atarist)
 /* The Atari operating system doesn't have a dynamic stack.  The
diff --git a/objXSUB.h b/objXSUB.h
index bbe9f7dc7c..bc17e877b2 100644
--- a/objXSUB.h
+++ b/objXSUB.h
@@ -2190,6 +2190,8 @@
 #  endif
 #endif
 #if defined(PERL_IN_TOKE_C) || defined(PERL_DECL_PROT)
+#if 0
+#endif
 #  if defined(CRIPPLED_CC)
 #  endif
 #  if defined(PERL_CR_FILTER)
diff --git a/op.c b/op.c
index adf6aee7e0..11ff181c83 100644
--- a/op.c
+++ b/op.c
@@ -124,11 +124,10 @@ Perl_pad_allocmy(pTHX_ char *name)
     PADOFFSET off;
     SV *sv;
 
-    if (!(
-	PL_in_my == KEY_our ||
-	isALPHA(name[1]) ||
-	(PL_hints & HINT_UTF8 && (name[1] & 0xc0) == 0xc0) ||
-	name[1] == '_' && (int)strlen(name) > 2 ))
+    if (!(PL_in_my == KEY_our ||
+	  isALPHA(name[1]) ||
+	  (PL_hints & HINT_UTF8 && (name[1] & 0xc0) == 0xc0) ||
+	  (name[1] == '_' && (int)strlen(name) > 2)))
     {
 	if (!isPRINT(name[1]) || strchr("\t\n\r\f", name[1])) {
 	    /* 1999-02-27 mjd@plover.com */
@@ -976,7 +975,7 @@ Perl_scalar(pTHX_ OP *o)
     case OP_LEAVETRY:
 	kid = cLISTOPo->op_first;
 	scalar(kid);
-	while (kid = kid->op_sibling) {
+	while ((kid = kid->op_sibling)) {
 	    if (kid->op_sibling)
 		scalarvoid(kid);
 	    else
@@ -1269,7 +1268,7 @@ Perl_list(pTHX_ OP *o)
     case OP_LEAVETRY:
 	kid = cLISTOPo->op_first;
 	list(kid);
-	while (kid = kid->op_sibling) {
+	while ((kid = kid->op_sibling)) {
 	    if (kid->op_sibling)
 		scalarvoid(kid);
 	    else
@@ -1339,7 +1338,6 @@ Perl_mod(pTHX_ OP *o, I32 type)
 {
     dTHR;
     OP *kid;
-    SV *sv;
     STRLEN n_a;
 
     if (!o || PL_error_count)
@@ -2355,8 +2353,11 @@ Perl_append_elem(pTHX_ I32 type, OP *first, OP *last)
     if (!last)
 	return first;
 
-    if (first->op_type != type || type==OP_LIST && first->op_flags & OPf_PARENS)
-	    return newLISTOP(type, 0, first, last);
+    if (first->op_type != type
+	|| (type == OP_LIST && (first->op_flags & OPf_PARENS)))
+    {
+	return newLISTOP(type, 0, first, last);
+    }
 
     if (first->op_flags & OPf_KIDS)
 	((LISTOP*)first)->op_last->op_sibling = last;
@@ -2602,7 +2603,6 @@ Perl_pmtrans(pTHX_ OP *o, OP *expr, OP *repl)
 	I32 grows = 0;
 	I32 havefinal = 0;
 	U32 final;
-	HV *hv;
 	I32 from_utf	= o->op_private & OPpTRANS_FROM_UTF;
 	I32 to_utf	= o->op_private & OPpTRANS_TO_UTF;
 
@@ -3095,7 +3095,6 @@ void
 Perl_utilize(pTHX_ int aver, I32 floor, OP *version, OP *id, OP *arg)
 {
     OP *pack;
-    OP *meth;
     OP *rqop;
     OP *imop;
     OP *veop;
@@ -3125,7 +3124,7 @@ Perl_utilize(pTHX_ int aver, I32 floor, OP *version, OP *id, OP *arg)
 	    /* Fake up a method call to VERSION */
 	    meth = newSVpvn("VERSION",7);
 	    sv_upgrade(meth, SVt_PVIV);
-	    SvIOK_on(meth);
+	    (void)SvIOK_on(meth);
 	    PERL_HASH(SvUVX(meth), SvPVX(meth), SvCUR(meth));
 	    veop = convert(OP_ENTERSUB, OPf_STACKED|OPf_SPECIAL,
 			    append_elem(OP_LIST,
@@ -3149,7 +3148,7 @@ Perl_utilize(pTHX_ int aver, I32 floor, OP *version, OP *id, OP *arg)
 	/* Fake up a method call to import/unimport */
 	meth = aver ? newSVpvn("import",6) : newSVpvn("unimport", 8);;
 	sv_upgrade(meth, SVt_PVIV);
-	SvIOK_on(meth);
+	(void)SvIOK_on(meth);
 	PERL_HASH(SvUVX(meth), SvPVX(meth), SvCUR(meth));
 	imop = convert(OP_ENTERSUB, OPf_STACKED|OPf_SPECIAL,
 		       append_elem(OP_LIST,
@@ -3868,7 +3867,6 @@ OP *
 Perl_newFOROP(pTHX_ I32 flags,char *label,line_t forline,OP *sv,OP *expr,OP *block,OP *cont)
 {
     LOOP *loop;
-    LOOP *tmp;
     OP *wop;
     int padoff = 0;
     I32 iterflags = 0;
@@ -3943,9 +3941,12 @@ Perl_newFOROP(pTHX_ I32 flags,char *label,line_t forline,OP *sv,OP *expr,OP *blo
 			       append_elem(OP_LIST, expr, scalar(sv))));
     assert(!loop->op_next);
 #ifdef PL_OP_SLAB_ALLOC
-    NewOp(1234,tmp,1,LOOP);
-    Copy(loop,tmp,1,LOOP);
-    loop = tmp;
+    {
+	LOOP *tmp;
+	NewOp(1234,tmp,1,LOOP);
+	Copy(loop,tmp,1,LOOP);
+	loop = tmp;
+    }
 #else
     Renew(loop, 1, LOOP);
 #endif 
@@ -4377,7 +4378,7 @@ Perl_newATTRSUB(pTHX_ I32 floor, OP *o, OP *proto, OP *attrs, OP *block)
 
     if (!name || GvCVGEN(gv))
 	cv = Nullcv;
-    else if (cv = GvCV(gv)) {
+    else if ((cv = GvCV(gv))) {
 	cv_ckproto(cv, gv, ps);
 	/* already defined (or promised)? */
 	if (CvROOT(cv) || CvXSUB(cv) || GvASSUMECV(gv)) {
@@ -4393,7 +4394,7 @@ Perl_newATTRSUB(pTHX_ I32 floor, OP *o, OP *proto, OP *attrs, OP *block)
 		Perl_croak(aTHX_ "Can't redefine active sort subroutine %s", name);
 	    if (!block)
 		goto withattrs;
-	    if (const_sv = cv_const_sv(cv))
+	    if ((const_sv = cv_const_sv(cv)))
 		const_changed = sv_cmp(const_sv, op_const_sv(block, Nullcv));
 	    if ((const_sv || const_changed) && ckWARN(WARN_REDEFINE))
 	    {
@@ -4561,7 +4562,6 @@ Perl_newATTRSUB(pTHX_ I32 floor, OP *o, OP *proto, OP *attrs, OP *block)
 	    GV *db_postponed = gv_fetchpv("DB::postponed", GV_ADDMULTI, SVt_PVHV);
 	    CV *pcv;
 	    HV *hv;
-	    char *t;
 
 	    Perl_sv_setpvf(aTHX_ sv, "%s:%ld-%ld",
 			   CopFILE(PL_curcop),
@@ -4697,7 +4697,7 @@ Perl_newXS(pTHX_ char *name, XSUBADDR_t subaddr, char *filename)
     GV *gv = gv_fetchpv(name ? name : "__ANON__", GV_ADDMULTI, SVt_PVCV);
     register CV *cv;
 
-    if (cv = (name ? GvCV(gv) : Nullcv)) {
+    if ((cv = (name ? GvCV(gv) : Nullcv))) {
 	if (GvCVGEN(gv)) {
 	    /* just a cached method */
 	    SvREFCNT_dec(cv);
@@ -4801,7 +4801,7 @@ Perl_newFORM(pTHX_ I32 floor, OP *o, OP *block)
 	name = "STDOUT";
     gv = gv_fetchpv(name,TRUE, SVt_PVFM);
     GvMULTI_on(gv);
-    if (cv = GvFORM(gv)) {
+    if ((cv = GvFORM(gv))) {
 	if (ckWARN(WARN_REDEFINE)) {
 	    line_t oldline = CopLINE(PL_curcop);
 
@@ -5337,7 +5337,7 @@ Perl_ck_fun(pTHX_ OP *o)
 	tokid = &cLISTOPo->op_first;
 	kid = cLISTOPo->op_first;
 	if (kid->op_type == OP_PUSHMARK ||
-	    kid->op_type == OP_NULL && kid->op_targ == OP_PUSHMARK)
+	    (kid->op_type == OP_NULL && kid->op_targ == OP_PUSHMARK))
 	{
 	    tokid = &kid->op_sibling;
 	    kid = kid->op_sibling;
@@ -5465,7 +5465,7 @@ Perl_ck_fun(pTHX_ OP *o)
 				SV *namesv;
 				targ = pad_alloc(OP_RV2GV, SVs_PADTMP);
 				namesv = PL_curpad[targ];
-				SvUPGRADE(namesv, SVt_PV);
+				(void)SvUPGRADE(namesv, SVt_PV);
 				if (*name != '$')
 				    sv_setpvn(namesv, "$", 1);
 				sv_catpvn(namesv, name, len);
@@ -5780,8 +5780,8 @@ Perl_ck_method(pTHX_ OP *o)
 	SV* sv = kSVOP->op_sv;
 	if (!(strchr(SvPVX(sv), ':') || strchr(SvPVX(sv), '\''))) {
 	    OP *cmop;
-	    sv_upgrade(sv, SVt_PVIV);
-	    SvIOK_on(sv);
+	    (void)SvUPGRADE(sv, SVt_PVIV);
+	    (void)SvIOK_on(sv);
 	    PERL_HASH(SvUVX(sv), SvPVX(sv), SvCUR(sv));
 	    cmop = newSVOP(OP_METHOD_NAMED, 0, sv);
 	    kSVOP->op_sv = Nullsv;
diff --git a/perl.c b/perl.c
index c006a63480..37f68e721b 100644
--- a/perl.c
+++ b/perl.c
@@ -243,7 +243,7 @@ perl_construct(pTHXx)
     {
 	U8 *s;
 	PL_patchlevel = NEWSV(0,4);
-	SvUPGRADE(PL_patchlevel, SVt_PVNV);
+	(void)SvUPGRADE(PL_patchlevel, SVt_PVNV);
 	if (PERL_REVISION > 127 || PERL_VERSION > 127 || PERL_SUBVERSION > 127)
 	    SvGROW(PL_patchlevel, UTF8_MAXLEN*3+1);
 	s = (U8*)SvPVX(PL_patchlevel);
@@ -373,7 +373,7 @@ perl_destruct(pTHXx)
 #ifdef DEBUGGING
     {
 	char *s;
-	if (s = PerlEnv_getenv("PERL_DESTRUCT_LEVEL")) {
+	if ((s = PerlEnv_getenv("PERL_DESTRUCT_LEVEL"))) {
 	    int i = atoi(s);
 	    if (destruct_level < i)
 		destruct_level = i;
@@ -729,7 +729,7 @@ perl_destruct(pTHXx)
 	    }
 	}
 	/* we know that type >= SVt_PV */
-	SvOOK_off(PL_mess_sv);
+	(void)SvOOK_off(PL_mess_sv);
 	Safefree(SvPVX(PL_mess_sv));
 	Safefree(SvANY(PL_mess_sv));
 	Safefree(PL_mess_sv);
@@ -935,7 +935,7 @@ S_parse_body(pTHX_ char **env, XSINIT_t xsinit)
 	case 'W':
 	case 'X':
 	case 'w':
-	    if (s = moreswitches(s))
+	    if ((s = moreswitches(s)))
 		goto reswitch;
 	    break;
 
@@ -1905,7 +1905,7 @@ Perl_magicname(pTHX_ char *sym, char *name, I32 namlen)
 {
     register GV *gv;
 
-    if (gv = gv_fetchpv(sym,TRUE, SVt_PV))
+    if ((gv = gv_fetchpv(sym,TRUE, SVt_PV)))
 	sv_magic(GvSV(gv), (SV*)gv, 0, name, namlen);
 }
 
@@ -2414,7 +2414,6 @@ STATIC void
 S_open_script(pTHX_ char *scriptname, bool dosearch, SV *sv, int *fdscript)
 {
     dTHR;
-    register char *s;
 
     *fdscript = -1;
 
@@ -2666,7 +2665,9 @@ S_fd_on_nosuid_fs(pTHX_ int fd)
 STATIC void
 S_validate_suid(pTHX_ char *validarg, char *scriptname, int fdscript)
 {
+#ifdef IAMSUID
     int which;
+#endif
 
     /* do we need to emulate setuid on scripts? */
 
@@ -2933,7 +2934,8 @@ S_find_beginning(pTHX)
 		while (isDIGIT(s2[-1]) || strchr("-._", s2[-1])) s2--;
 		if (strnEQ(s2-4,"perl",4))
 		    /*SUPPRESS 530*/
-		    while (s = moreswitches(s)) ;
+		    while ((s = moreswitches(s)))
+			;
 	    }
 	}
     }
@@ -3073,7 +3075,6 @@ S_init_predump_symbols(pTHX)
 {
     dTHR;
     GV *tmpgv;
-    GV *othergv;
     IO *io;
 
     sv_setpvn(get_sv("\"", TRUE), " ", 1);
@@ -3125,7 +3126,7 @@ S_init_postdump_symbols(pTHX_ register int argc, register char **argv, register
 		argc--,argv++;
 		break;
 	    }
-	    if (s = strchr(argv[0], '=')) {
+	    if ((s = strchr(argv[0], '='))) {
 		*s++ = '\0';
 		sv_setpv(GvSV(gv_fetchpv(argv[0]+1,TRUE, SVt_PV)),s);
 	    }
@@ -3142,17 +3143,17 @@ S_init_postdump_symbols(pTHX_ register int argc, register char **argv, register
     PL_formtarget = PL_bodytarget;
 
     TAINT;
-    if (tmpgv = gv_fetchpv("0",TRUE, SVt_PV)) {
+    if ((tmpgv = gv_fetchpv("0",TRUE, SVt_PV))) {
 	sv_setpv(GvSV(tmpgv),PL_origfilename);
 	magicname("0", "0", 1);
     }
-    if (tmpgv = gv_fetchpv("\030",TRUE, SVt_PV))
+    if ((tmpgv = gv_fetchpv("\030",TRUE, SVt_PV)))
 #ifdef OS2
 	sv_setpv(GvSV(tmpgv), os2_execname());
 #else
 	sv_setpv(GvSV(tmpgv),PL_origargv[0]);
 #endif
-    if (PL_argvgv = gv_fetchpv("ARGV",TRUE, SVt_PVAV)) {
+    if ((PL_argvgv = gv_fetchpv("ARGV",TRUE, SVt_PVAV))) {
 	GvMULTI_on(PL_argvgv);
 	(void)gv_AVadd(PL_argvgv);
 	av_clear(GvAVn(PL_argvgv));
@@ -3163,7 +3164,7 @@ S_init_postdump_symbols(pTHX_ register int argc, register char **argv, register
 		sv_utf8_upgrade(sv);
 	}
     }
-    if (PL_envgv = gv_fetchpv("ENV",TRUE, SVt_PVHV)) {
+    if ((PL_envgv = gv_fetchpv("ENV",TRUE, SVt_PVHV))) {
 	HV *hv;
 	GvMULTI_on(PL_envgv);
 	hv = GvHVn(PL_envgv);
@@ -3199,7 +3200,7 @@ S_init_postdump_symbols(pTHX_ register int argc, register char **argv, register
 #endif
     }
     TAINT_NOT;
-    if (tmpgv = gv_fetchpv("$",TRUE, SVt_PV))
+    if ((tmpgv = gv_fetchpv("$",TRUE, SVt_PV)))
 	sv_setiv(GvSV(tmpgv), (IV)PerlProc_getpid());
 }
 
diff --git a/perlapi.c b/perlapi.c
index 7c19c22d8b..1d619ef81e 100644
--- a/perlapi.c
+++ b/perlapi.c
@@ -3909,6 +3909,8 @@ Perl_ptr_table_split(pTHXo_ PTR_TBL_t *tbl)
 #  endif
 #endif
 #if defined(PERL_IN_TOKE_C) || defined(PERL_DECL_PROT)
+#if 0
+#endif
 #  if defined(CRIPPLED_CC)
 #  endif
 #  if defined(PERL_CR_FILTER)
diff --git a/pp.c b/pp.c
index fcae1e4db7..4210bd6c6f 100644
--- a/pp.c
+++ b/pp.c
@@ -2901,7 +2901,7 @@ PP(pp_splice)
     SV **tmparyval = 0;
     MAGIC *mg;
 
-    if (mg = SvTIED_mg((SV*)ary, 'P')) {
+    if ((mg = SvTIED_mg((SV*)ary, 'P'))) {
 	*MARK-- = SvTIED_obj((SV*)ary, mg);
 	PUSHMARK(MARK);
 	PUTBACK;
@@ -3095,7 +3095,7 @@ PP(pp_push)
     register SV *sv = &PL_sv_undef;
     MAGIC *mg;
 
-    if (mg = SvTIED_mg((SV*)ary, 'P')) {
+    if ((mg = SvTIED_mg((SV*)ary, 'P'))) {
 	*MARK-- = SvTIED_obj((SV*)ary, mg);
 	PUSHMARK(MARK);
 	PUTBACK;
@@ -3151,7 +3151,7 @@ PP(pp_unshift)
     register I32 i = 0;
     MAGIC *mg;
 
-    if (mg = SvTIED_mg((SV*)ary, 'P')) {
+    if ((mg = SvTIED_mg((SV*)ary, 'P'))) {
 	*MARK-- = SvTIED_obj((SV*)ary, mg);
 	PUSHMARK(MARK);
 	PUTBACK;
@@ -4170,7 +4170,7 @@ PP(pp_unpack)
                 int i;
  
                 for (i = 0; i < sizeof(PL_uuemap); i += 1)
-                    PL_uudmap[PL_uuemap[i]] = i;
+                    PL_uudmap[(U8)PL_uuemap[i]] = i;
                 /*
                  * Because ' ' and '`' map to the same value,
                  * we need to decode them both the same.
@@ -4187,22 +4187,22 @@ PP(pp_unpack)
 		char hunk[4];
 
 		hunk[3] = '\0';
-		len = PL_uudmap[*s++] & 077;
+		len = PL_uudmap[*(U8*)s++] & 077;
 		while (len > 0) {
 		    if (s < strend && ISUUCHAR(*s))
-			a = PL_uudmap[*s++] & 077;
+			a = PL_uudmap[*(U8*)s++] & 077;
  		    else
  			a = 0;
 		    if (s < strend && ISUUCHAR(*s))
-			b = PL_uudmap[*s++] & 077;
+			b = PL_uudmap[*(U8*)s++] & 077;
  		    else
  			b = 0;
 		    if (s < strend && ISUUCHAR(*s))
-			c = PL_uudmap[*s++] & 077;
+			c = PL_uudmap[*(U8*)s++] & 077;
  		    else
  			c = 0;
 		    if (s < strend && ISUUCHAR(*s))
-			d = PL_uudmap[*s++] & 077;
+			d = PL_uudmap[*(U8*)s++] & 077;
 		    else
 			d = 0;
 		    hunk[0] = (a << 2) | (b >> 4);
@@ -4442,7 +4442,7 @@ PP(pp_pack)
 	    len = 1;
 	if (*pat == '/') {
 	    ++pat;
-	    if (*pat != 'a' && *pat != 'A' && *pat != 'Z' || pat[1] != '*')
+	    if ((*pat != 'a' && *pat != 'A' && *pat != 'Z') || pat[1] != '*')
 		DIE(aTHX_ "/ must be followed by a*, A* or Z*");
 	    lengthcode = sv_2mortal(newSViv(sv_len(items > 0
 						   ? *MARK : &PL_sv_no)));
@@ -5004,7 +5004,7 @@ PP(pp_split)
 	av_extend(ary,0);
 	av_clear(ary);
 	SPAGAIN;
-	if (mg = SvTIED_mg((SV*)ary, 'P')) {
+	if ((mg = SvTIED_mg((SV*)ary, 'P'))) {
 	    PUSHMARK(SP);
 	    XPUSHs(SvTIED_obj((SV*)ary, mg));
 	}
@@ -5276,8 +5276,8 @@ PP(pp_lock)
 
 PP(pp_threadsv)
 {
-    djSP;
 #ifdef USE_THREADS
+    djSP;
     EXTEND(SP, 1);
     if (PL_op->op_private & OPpLVAL_INTRO)
 	PUSHs(*save_threadsv(PL_op->op_targ));
diff --git a/pp_ctl.c b/pp_ctl.c
index 552359258b..22db833475 100644
--- a/pp_ctl.c
+++ b/pp_ctl.c
@@ -859,7 +859,7 @@ PP(pp_sort)
     up = myorigmark + 1;
     while (MARK < SP) {	/* This may or may not shift down one here. */
 	/*SUPPRESS 560*/
-	if (*up = *++MARK) {			/* Weed out nulls. */
+	if ((*up = *++MARK)) {			/* Weed out nulls. */
 	    SvTEMP_off(*up);
 	    if (!PL_sortcop && !SvPOK(*up)) {
 		STRLEN n_a;
@@ -1238,7 +1238,6 @@ Perl_dounwind(pTHX_ I32 cxix)
 {
     dTHR;
     register PERL_CONTEXT *cx;
-    SV **newsp;
     I32 optype;
 
     while (cxstack_ix > cxix) {
@@ -1322,7 +1321,6 @@ Perl_qerror(pTHX_ SV *err)
 OP *
 Perl_die_where(pTHX_ char *message, STRLEN msglen)
 {
-    dSP;
     STRLEN n_a;
     if (PL_in_eval) {
 	I32 cxix;
@@ -2053,7 +2051,7 @@ S_dofindlabel(pTHX_ OP *o, char *label, OP **opstack, OP **oplimit)
 		 (ops[-1]->op_type != OP_NEXTSTATE &&
 		  ops[-1]->op_type != OP_DBSTATE)))
 		*ops++ = kid;
-	    if (o = dofindlabel(kid, label, ops, oplimit))
+	    if ((o = dofindlabel(kid, label, ops, oplimit)))
 		return o;
 	}
     }
@@ -2147,7 +2145,6 @@ PP(pp_goto)
 	    }
 	    else if (CvXSUB(cv)) {	/* put GvAV(defgv) back onto stack */
 		AV* av;
-		int i;
 #ifdef USE_THREADS
 		av = (AV*)PL_curpad[0];
 #else
@@ -2600,7 +2597,7 @@ Perl_sv_compile_2op(pTHX_ SV *sv, OP** startop, char *code, AV** avp)
     I32 gimme = 0;   /* SUSPECT - INITIALZE TO WHAT?  NI-S */
     I32 optype;
     OP dummy;
-    OP *oop = PL_op, *rop;
+    OP *rop;
     char tbuf[TYPE_DIGITS(long) + 12 + 10];
     char *tmpbuf = tbuf;
     char *safestr;
@@ -3997,7 +3994,7 @@ S_qsortsv(pTHX_ SV ** array, size_t num_elts, SVCOMPARE_t compare)
                on the correct side of the partition. If I find a greater
                value, then stop the scan.
             */
-            while (still_work_on_left = (u_right >= part_left)) {
+            while ((still_work_on_left = (u_right >= part_left))) {
                s = qsort_cmp(u_right, pc_left);
                if (s < 0) {
                   --u_right;
@@ -4018,7 +4015,7 @@ S_qsortsv(pTHX_ SV ** array, size_t num_elts, SVCOMPARE_t compare)
 
             /* Do a mirror image scan of uncompared values on the right
             */
-            while (still_work_on_right = (u_left <= part_right)) {
+            while ((still_work_on_right = (u_left <= part_right))) {
                s = qsort_cmp(pc_right, u_left);
                if (s < 0) {
                   ++u_left;
diff --git a/pp_hot.c b/pp_hot.c
index d2eef9b84a..beb2cf28f3 100644
--- a/pp_hot.c
+++ b/pp_hot.c
@@ -107,7 +107,6 @@ PP(pp_and)
 PP(pp_sassign)
 {
     djSP; dPOPTOPssrl;
-    MAGIC *mg;
 
     if (PL_op->op_private & OPpASSIGN_BACKWARDS) {
 	SV *temp;
@@ -335,7 +334,7 @@ PP(pp_print)
 	gv = (GV*)*++MARK;
     else
 	gv = PL_defoutgv;
-    if (mg = SvTIED_mg((SV*)gv, 'q')) {
+    if ((mg = SvTIED_mg((SV*)gv, 'q'))) {
 	if (MARK == ORIGMARK) {
 	    /* If using default handle then we need to make space to 
 	     * pass object as 1st arg, so move other args up ...
@@ -626,7 +625,6 @@ S_do_maybe_phash(pTHX_ AV *ary, SV **lelem, SV **firstlelem, SV **relem,
 		 SV **lastrelem)
 {
     OP *leftop;
-    SV *tmpstr;
     I32 i;
 
     leftop = ((BINOP*)PL_op)->op_last;
@@ -737,7 +735,7 @@ PP(pp_aassign)
 	EXTEND_MORTAL(lastrelem - firstrelem + 1);
 	for (relem = firstrelem; relem <= lastrelem; relem++) {
 	    /*SUPPRESS 560*/
-	    if (sv = *relem) {
+	    if ((sv = *relem)) {
 		TAINT_NOT;	/* Each item is independent */
 		*relem = sv_mortalcopy(sv);
 	    }
@@ -979,7 +977,7 @@ PP(pp_match)
     truebase = t = s;
 
     /* XXXX What part of this is needed with true \G-support? */
-    if (global = pm->op_pmflags & PMf_GLOBAL) {
+    if ((global = pm->op_pmflags & PMf_GLOBAL)) {
 	rx->startp[0] = -1;
 	if (SvTYPE(TARG) >= SVt_PVMG && SvMAGIC(TARG)) {
 	    MAGIC* mg = mg_find(TARG, 'g');
@@ -1157,7 +1155,7 @@ Perl_do_readline(pTHX)
     I32 gimme = GIMME_V;
     MAGIC *mg;
 
-    if (mg = SvTIED_mg((SV*)PL_last_in_gv, 'q')) {
+    if ((mg = SvTIED_mg((SV*)PL_last_in_gv, 'q'))) {
 	PUSHMARK(SP);
 	XPUSHs(SvTIED_obj((SV*)PL_last_in_gv, mg));
 	PUTBACK;
@@ -1659,9 +1657,9 @@ PP(pp_iter)
 
     SvREFCNT_dec(*itersvp);
 
-    if (sv = (SvMAGICAL(av)) 
-	    ? *av_fetch(av, ++cx->blk_loop.iterix, FALSE) 
-	    : AvARRAY(av)[++cx->blk_loop.iterix])
+    if ((sv = SvMAGICAL(av)
+	      ? *av_fetch(av, ++cx->blk_loop.iterix, FALSE) 
+	      : AvARRAY(av)[++cx->blk_loop.iterix]))
 	SvTEMP_off(sv);
     else
 	sv = &PL_sv_undef;
@@ -1712,7 +1710,6 @@ PP(pp_subst)
     STRLEN len;
     int force_on_match = 0;
     I32 oldsave = PL_savestack_ix;
-    I32 update_minmatch = 1;
 
     /* known replacement string? */
     dstr = (pm->op_pmflags & PMf_CONST) ? POPs : Nullsv;
@@ -1818,7 +1815,7 @@ PP(pp_subst)
 		SvCUR_set(TARG, m - s);
 	    }
 	    /*SUPPRESS 560*/
-	    else if (i = m - s) {	/* faster from front */
+	    else if ((i = m - s)) {	/* faster from front */
 		d -= clen;
 		m = d;
 		sv_chop(TARG, d-i);
@@ -1847,7 +1844,7 @@ PP(pp_subst)
 		rxtainted |= RX_MATCH_TAINTED(rx);
 		m = rx->startp[0] + orig;
 		/*SUPPRESS 560*/
-		if (i = m - s) {
+		if ((i = m - s)) {
 		    if (s != d)
 			Move(s, d, i, char);
 		    d += i;
@@ -2145,7 +2142,6 @@ PP(pp_leavesublv)
 			: "an uninitialized value");
 		}
 		else {
-		    mortalize:
 		    /* Can be a localized value subject to deletion. */
 		    PL_tmps_stack[++PL_tmps_ix] = *mark;
 		    (void)SvREFCNT_inc(*mark);
@@ -2223,8 +2219,8 @@ S_get_db_sub(pTHX_ SV **svp, CV *cv)
 	}
     }
     else {
-	SvUPGRADE(dbsv, SVt_PVIV);
-	SvIOK_on(dbsv);
+	(void)SvUPGRADE(dbsv, SVt_PVIV);
+	(void)SvIOK_on(dbsv);
 	SAVEIV(SvIVX(dbsv));
 	SvIVX(dbsv) = PTR2IV(cv);	/* Do it the quickest way  */
     }
@@ -2795,7 +2791,6 @@ PP(pp_method_named)
 STATIC SV *
 S_method_common(pTHX_ SV* meth, U32* hashp)
 {
-    djSP;
     SV* sv;
     SV* ob;
     GV* gv;
diff --git a/pp_sys.c b/pp_sys.c
index ee8605c6f5..da352a2fab 100644
--- a/pp_sys.c
+++ b/pp_sys.c
@@ -521,7 +521,7 @@ PP(pp_open)
     if (GvIOp(gv))
 	IoFLAGS(GvIOp(gv)) &= ~IOf_UNTAINT;
 
-    if (mg = SvTIED_mg((SV*)gv, 'q')) {
+    if ((mg = SvTIED_mg((SV*)gv, 'q'))) {
 	PUSHMARK(SP);
 	XPUSHs(SvTIED_obj((SV*)gv, mg));
 	XPUSHs(sv);
@@ -556,7 +556,7 @@ PP(pp_close)
     else
 	gv = (GV*)POPs;
 
-    if (mg = SvTIED_mg((SV*)gv, 'q')) {
+    if ((mg = SvTIED_mg((SV*)gv, 'q'))) {
 	PUSHMARK(SP);
 	XPUSHs(SvTIED_obj((SV*)gv, mg));
 	PUTBACK;
@@ -797,7 +797,7 @@ PP(pp_untie)
 
     if (ckWARN(WARN_UNTIE)) {
         MAGIC * mg ;
-        if (mg = SvTIED_mg(sv, how)) {
+        if ((mg = SvTIED_mg(sv, how))) {
             if (mg && SvREFCNT(SvRV(mg->mg_obj)) > 1)  
 		Perl_warner(aTHX_ WARN_UNTIE,
 		    "untie attempted while %"UVuf" inner references still exist",
@@ -816,7 +816,7 @@ PP(pp_tied)
     char how = (SvTYPE(sv) == SVt_PVHV || SvTYPE(sv) == SVt_PVAV) ? 'P' : 'q';
     MAGIC *mg;
 
-    if (mg = SvTIED_mg(sv, how)) {
+    if ((mg = SvTIED_mg(sv, how))) {
 	SV *osv = SvTIED_obj(sv, mg);
 	if (osv == mg->mg_obj)
 	    osv = sv_mortalcopy(osv);
@@ -1085,7 +1085,7 @@ PP(pp_getc)
     else
 	gv = (GV*)POPs;
 
-    if (mg = SvTIED_mg((SV*)gv, 'q')) {
+    if ((mg = SvTIED_mg((SV*)gv, 'q'))) {
 	I32 gimme = GIMME_V;
 	PUSHMARK(SP);
 	XPUSHs(SvTIED_obj((SV*)gv, mg));
@@ -1309,7 +1309,7 @@ PP(pp_prtf)
     else
 	gv = PL_defoutgv;
 
-    if (mg = SvTIED_mg((SV*)gv, 'q')) {
+    if ((mg = SvTIED_mg((SV*)gv, 'q'))) {
 	if (MARK == ORIGMARK) {
 	    MEXTEND(SP, 1);
 	    ++MARK;
@@ -3459,7 +3459,7 @@ PP(pp_readdir)
 
     if (GIMME == G_ARRAY) {
 	/*SUPPRESS 560*/
-	while (dp = (Direntry_t *)PerlDir_read(IoDIRP(io))) {
+	while ((dp = (Direntry_t *)PerlDir_read(IoDIRP(io)))) {
 #ifdef DIRNAMLEN
 	    sv = newSVpvn(dp->d_name, dp->d_namlen);
 #else
@@ -3618,7 +3618,7 @@ PP(pp_fork)
 	RETSETUNDEF;
     if (!childpid) {
 	/*SUPPRESS 560*/
-	if (tmpgv = gv_fetchpv("$", TRUE, SVt_PV))
+	if ((tmpgv = gv_fetchpv("$", TRUE, SVt_PV)))
 	    sv_setiv(GvSV(tmpgv), (IV)PerlProc_getpid());
 	hv_clear(PL_pidstatus);	/* no kids, so don't wait for 'em */
     }
@@ -4035,7 +4035,6 @@ PP(pp_gmtime)
     EXTEND(SP, 9);
     EXTEND_MORTAL(9);
     if (GIMME != G_ARRAY) {
-	dTARGET;
 	SV *tsv;
 	if (!tmbuf)
 	    RETPUSHUNDEF;
@@ -4993,7 +4992,6 @@ PP(pp_syscall)
     unsigned long a[20];
     register I32 i = 0;
     I32 retval = -1;
-    MAGIC *mg;
     STRLEN n_a;
 
     if (PL_tainting) {
diff --git a/proto.h b/proto.h
index 4ea8472760..c5a29fce29 100644
--- a/proto.h
+++ b/proto.h
@@ -1217,8 +1217,10 @@ STATIC SV*	S_new_constant(pTHX_ char *s, STRLEN len, const char *key, SV *sv, SV
 STATIC int	S_ao(pTHX_ int toketype);
 STATIC void	S_depcom(pTHX);
 STATIC char*	S_incl_perldb(pTHX);
+#if 0
 STATIC I32	S_utf16_textfilter(pTHX_ int idx, SV *sv, int maxlen);
 STATIC I32	S_utf16rev_textfilter(pTHX_ int idx, SV *sv, int maxlen);
+#endif
 #  if defined(CRIPPLED_CC)
 STATIC int	S_uni(pTHX_ I32 f, char *s);
 #  endif
diff --git a/regcomp.c b/regcomp.c
index 330dcbe429..9768d18c93 100644
--- a/regcomp.c
+++ b/regcomp.c
@@ -298,8 +298,6 @@ STATIC void
 S_cl_and(pTHX_ struct regnode_charclass_class *cl,
 	 struct regnode_charclass_class *and_with)
 {
-    int value;
-
     if (!(and_with->flags & ANYOF_CLASS)
 	&& !(cl->flags & ANYOF_CLASS)
 	&& (and_with->flags & ANYOF_LOCALE) == (cl->flags & ANYOF_LOCALE)
@@ -323,8 +321,6 @@ S_cl_and(pTHX_ struct regnode_charclass_class *cl,
 STATIC void
 S_cl_or(pTHX_ struct regnode_charclass_class *cl, struct regnode_charclass_class *or_with)
 {
-    int value;
-
     if (or_with->flags & ANYOF_INVERT) {
 	/* We do not use
 	 * (B1 | CL1) | (!B2 & !CL2) = (B1 | !B2 & !CL2) | (CL1 | (!B2 & !CL2))
@@ -602,7 +598,7 @@ S_study_chunk(pTHX_ regnode **scanp, I32 *deltap, regnode *last, scan_data_t *da
 		    && !ANYOF_BITMAP_TEST(data->start_class, *STRING(scan))
 		    && (!(data->start_class->flags & ANYOF_FOLD)
 			|| !ANYOF_BITMAP_TEST(data->start_class,
-					      PL_fold[*STRING(scan)])))
+					      PL_fold[*(U8*)STRING(scan)])))
 		    compat = 0;
 		ANYOF_CLASS_ZERO(data->start_class);
 		ANYOF_BITMAP_ZERO(data->start_class);
@@ -644,7 +640,7 @@ S_study_chunk(pTHX_ regnode **scanp, I32 *deltap, regnode *last, scan_data_t *da
 		if (!(data->start_class->flags & (ANYOF_CLASS | ANYOF_LOCALE)) 
 		    && !ANYOF_BITMAP_TEST(data->start_class, *STRING(scan))
 		    && !ANYOF_BITMAP_TEST(data->start_class, 
-					  PL_fold[*STRING(scan)]))
+					  PL_fold[*(U8*)STRING(scan)]))
 		    compat = 0;
 		ANYOF_CLASS_ZERO(data->start_class);
 		ANYOF_BITMAP_ZERO(data->start_class);
@@ -771,9 +767,9 @@ S_study_chunk(pTHX_ regnode **scanp, I32 *deltap, regnode *last, scan_data_t *da
 		    Perl_warner(aTHX_ WARN_REGEXP,
 				"Strange *+?{} on zero-length expression");
 		min += minnext * mincount;
-		is_inf_internal |= (maxcount == REG_INFTY 
-				    && (minnext + deltanext) > 0
-				   || deltanext == I32_MAX);
+		is_inf_internal |= ((maxcount == REG_INFTY 
+				     && (minnext + deltanext) > 0)
+				    || deltanext == I32_MAX);
 		is_inf |= is_inf_internal;
 		delta += (minnext + deltanext) * maxcount - minnext * mincount;
 
@@ -1326,9 +1322,6 @@ Perl_pregcomp(pTHX_ char *exp, char *xend, PMOP *pm)
     dTHR;
     register regexp *r;
     regnode *scan;
-    SV **longest;
-    SV *longest_fixed;
-    SV *longest_float;
     regnode *first;
     I32 flags;
     I32 minlen = 0;
@@ -2874,7 +2867,6 @@ S_regclass(pTHX)
     register I32 lastvalue = OOB_CHAR8;
     register I32 range = 0;
     register regnode *ret;
-    register I32 def;
     I32 numlen;
     I32 namedclass;
     char *rangebegin;
@@ -3704,7 +3696,6 @@ S_regtail(pTHX_ regnode *p, regnode *val)
     dTHR;
     register regnode *scan;
     register regnode *temp;
-    register I32 offset;
 
     if (SIZE_ONLY)
 	return;
@@ -3773,7 +3764,7 @@ S_dumpuntil(pTHX_ regnode *start, regnode *node, regnode *last, SV* sv, I32 l)
 {
 #ifdef DEBUGGING
     register U8 op = EXACT;	/* Arbitrary non-END op. */
-    register regnode *next, *onode;
+    register regnode *next;
 
     while (op != END && (!last || node < last)) {
 	/* While that wasn't END last time... */
diff --git a/regexec.c b/regexec.c
index 4775e4962e..3b6d8577a7 100644
--- a/regexec.c
+++ b/regexec.c
@@ -1274,10 +1274,9 @@ Perl_regexec_flags(pTHX_ register regexp *prog, char *stringarg, register char *
     register char *s;
     register regnode *c;
     register char *startpos = stringarg;
-    register I32 tmp;
     I32 minlen;		/* must match at least this many chars */
     I32 dontbother = 0;	/* how many characters not to try at end */
-    I32 start_shift = 0;		/* Offset of the start to find
+    /* I32 start_shift = 0; */		/* Offset of the start to find
 					 constant substr. */		/* CC */
     I32 end_shift = 0;			/* Same for the end. */		/* CC */
     I32 scream_pos = -1;		/* Internal iterator of scream. */
@@ -1466,7 +1465,6 @@ Perl_regexec_flags(pTHX_ register regexp *prog, char *stringarg, register char *
 	    prog->anchored_substr ? prog->anchored_offset : prog->float_max_offset;
 	I32 back_min = 
 	    prog->anchored_substr ? prog->anchored_offset : prog->float_min_offset;
-	I32 delta = back_max - back_min;
 	char *last = HOPc(strend,	/* Cannot start after this */
 			  -(I32)(CHR_SVLEN(must)
 				 - (SvTAIL(must) != 0) + back_min));
@@ -1516,7 +1514,7 @@ Perl_regexec_flags(pTHX_ register regexp *prog, char *stringarg, register char *
 	}
 	goto phooey;
     }
-    else if (c = prog->regstclass) {
+    else if ((c = prog->regstclass)) {
 	if (minlen && PL_regkind[(U8)OP(prog->regstclass)] != EXACT)
 	    /* don't bother with what can't match */
 	    strend = HOPc(strend, -(minlen - 1));
@@ -1527,7 +1525,6 @@ Perl_regexec_flags(pTHX_ register regexp *prog, char *stringarg, register char *
 	dontbother = 0;
 	if (prog->float_substr != Nullsv) {	/* Trim the end. */
 	    char *last;
-	    I32 oldpos = scream_pos;
 
 	    if (flags & REXEC_SCREAM) {
 		last = screaminstr(sv, prog->float_substr, s - strbeg,
@@ -1894,12 +1891,12 @@ S_regmatch(pTHX_ regnode *prog)
 		nextchr = UCHARAT(locinput);
 		break;
 	    }
-	    if (!nextchr && locinput >= PL_regeol || nextchr == '\n')
+	    if ((!nextchr && locinput >= PL_regeol) || nextchr == '\n')
 		sayNO;
 	    nextchr = UCHARAT(++locinput);
 	    break;
 	case REG_ANY:
-	    if (!nextchr && locinput >= PL_regeol || nextchr == '\n')
+	    if ((!nextchr && locinput >= PL_regeol) || nextchr == '\n')
 		sayNO;
 	    nextchr = UCHARAT(++locinput);
 	    break;
@@ -2765,7 +2762,7 @@ S_regmatch(pTHX_ regnode *prog)
 			*PL_reglastparen = n;
 			scan = next;
 			/*SUPPRESS 560*/
-			if (n = (c1 == BRANCH ? NEXT_OFF(next) : ARG(next)))
+			if ((n = (c1 == BRANCH ? NEXT_OFF(next) : ARG(next))))
 			    next += n;
 			else
 			    next = NULL;
@@ -3609,7 +3606,6 @@ S_reginclassutf8(pTHX_ regnode *f, U8 *p)
     if (swash_fetch(sv, p))
 	match = TRUE;
     else if (flags & ANYOF_FOLD) {
-	I32 cf;
 	U8 tmpbuf[UTF8_MAXLEN];
 	if (flags & ANYOF_LOCALE) {
 	    PL_reg_flags |= RF_tainted;
diff --git a/regexp.h b/regexp.h
index 9e86a1efaa..ca0e9ed5da 100644
--- a/regexp.h
+++ b/regexp.h
@@ -94,7 +94,7 @@ typedef struct regexp {
 #define REXEC_NOT_FIRST	0x10		/* This is another iteration of //g. */
 #define REXEC_ML	0x20		/* $* was set. */
 
-#define ReREFCNT_inc(re) ((re && re->refcnt++), re)
+#define ReREFCNT_inc(re) ((void)(re && re->refcnt++), re)
 #define ReREFCNT_dec(re) CALLREGFREE(aTHX_ re)
 
 #define FBMcf_TAIL_DOLLAR	1
diff --git a/run.c b/run.c
index 57f90dee64..728b761ff0 100644
--- a/run.c
+++ b/run.c
@@ -22,7 +22,7 @@ Perl_runops_standard(pTHX)
 {
     dTHR;
 
-    while ( PL_op = CALL_FPTR(PL_op->op_ppaddr)(aTHX) ) {
+    while ((PL_op = CALL_FPTR(PL_op->op_ppaddr)(aTHX))) {
 	PERL_ASYNC_CHECK();
     }
 
@@ -53,7 +53,7 @@ Perl_runops_debug(pTHX)
 	    DEBUG_t(debop(PL_op));
 	    DEBUG_P(debprof(PL_op));
 	}
-    } while ( PL_op = CALL_FPTR(PL_op->op_ppaddr)(aTHX) );
+    } while ((PL_op = CALL_FPTR(PL_op->op_ppaddr)(aTHX)));
 
     TAINT_NOT;
     return 0;
diff --git a/scope.c b/scope.c
index 3680a88e5f..3b9f0d108a 100644
--- a/scope.c
+++ b/scope.c
@@ -79,7 +79,6 @@ PERL_SI *
 Perl_new_stackinfo(pTHX_ I32 stitems, I32 cxitems)
 {
     PERL_SI *si;
-    PERL_CONTEXT *cxt;
     New(56, si, 1, PERL_SI);
     si->si_stack = newAV();
     AvREAL_off(si->si_stack);
diff --git a/sv.c b/sv.c
index 2312eb0433..f0fcfc0fdd 100644
--- a/sv.c
+++ b/sv.c
@@ -1938,11 +1938,9 @@ Perl_sv_2pv_nolen(pTHX_ register SV *sv)
 static char *
 uiv_2buf(char *buf, IV iv, UV uv, int is_uv, char **peob)
 {
-    STRLEN len;
     char *ptr = buf + TYPE_CHARS(UV);
     char *ebuf = ptr;
     int sign;
-    char *p;
 
     if (is_uv)
 	sign = 0;
@@ -2033,7 +2031,7 @@ Perl_sv_2pv(pTHX_ register SV *sv, STRLEN *lp)
 			    int right = 4;
  			    U16 reganch = (re->reganch & PMf_COMPILETIME) >> 12;
 
- 			    while(ch = *fptr++) {
+ 			    while((ch = *fptr++)) {
  				if(reganch & 1) {
  				    reflags[left++] = ch;
  				}
@@ -3091,7 +3089,7 @@ Perl_sv_catsv(pTHX_ SV *dstr, register SV *sstr)
     STRLEN len;
     if (!sstr)
 	return;
-    if (s = SvPV(sstr, len)) {
+    if ((s = SvPV(sstr, len))) {
 	if (SvUTF8(sstr))
 	    sv_utf8_upgrade(dstr);
 	sv_catpvn(dstr,s,len);
@@ -3502,7 +3500,7 @@ Perl_sv_insert(pTHX_ SV *bigstr, STRLEN offset, STRLEN len, char *little, STRLEN
 	SvCUR_set(bigstr, mid - big);
     }
     /*SUPPRESS 560*/
-    else if (i = mid - big) {	/* faster from front */
+    else if ((i = mid - big)) {	/* faster from front */
 	midend -= littlelen;
 	mid = midend;
 	sv_chop(bigstr,midend-i);
@@ -3949,7 +3947,6 @@ Perl_sv_cmp(pTHX_ register SV *str1, register SV *str2)
     STRLEN cur1, cur2;
     char *pv1, *pv2;
     I32 retval;
-    bool utf1;
 
     if (str1) {
         pv1 = SvPV(str1, cur1);
@@ -5471,7 +5468,7 @@ Perl_sv_tainted(pTHX_ SV *sv)
 {
     if (SvTYPE(sv) >= SVt_PVMG && SvMAGIC(sv)) {
 	MAGIC *mg = mg_find(sv, 't');
-	if (mg && ((mg->mg_len & 1) || (mg->mg_len & 2) && mg->mg_obj == sv))
+	if (mg && ((mg->mg_len & 1) || ((mg->mg_len & 2) && mg->mg_obj == sv)))
 	    return TRUE;
     }
     return FALSE;
@@ -6610,9 +6607,6 @@ char *PL_watch_pvx;
 SV *
 Perl_sv_dup(pTHX_ SV *sstr)
 {
-    U32 sflags;
-    int dtype;
-    int stype;
     SV *dstr;
 
     if (!sstr || SvTYPE(sstr) == SVTYPEMASK)
@@ -6847,7 +6841,6 @@ Perl_sv_dup(pTHX_ SV *sstr)
 	SvSTASH(dstr)	= hv_dup_inc(SvSTASH(sstr));
 	HvRITER((HV*)dstr)	= HvRITER((HV*)sstr);
 	if (HvARRAY((HV*)sstr)) {
-	    HE *entry;
 	    STRLEN i = 0;
 	    XPVHV *dxhv = (XPVHV*)SvANY(dstr);
 	    XPVHV *sxhv = (XPVHV*)SvANY(sstr);
@@ -7334,8 +7327,6 @@ perl_clone_using(PerlInterpreter *proto_perl, UV flags,
      * their pointers copied. */
 
     IV i;
-    SV *sv;
-    SV **svp;
 #  ifdef PERL_OBJECT
     CPerlObj *pPerl = new(ipM) CPerlObj(ipM, ipMS, ipMP, ipE, ipStd, ipLIO,
 					ipD, ipS, ipP);
@@ -7367,8 +7358,6 @@ perl_clone_using(PerlInterpreter *proto_perl, UV flags,
 #  endif	/* PERL_OBJECT */
 #else		/* !PERL_IMPLICIT_SYS */
     IV i;
-    SV *sv;
-    SV **svp;
     PerlInterpreter *my_perl = (PerlInterpreter*)PerlMem_malloc(sizeof(PerlInterpreter));
     PERL_SET_THX(my_perl);
 
@@ -8011,10 +8000,10 @@ do_clean_named_objs(pTHXo_ SV *sv)
 {
     if (SvTYPE(sv) == SVt_PVGV && GvGP(sv)) {
 	if ( SvOBJECT(GvSV(sv)) ||
-	     GvAV(sv) && SvOBJECT(GvAV(sv)) ||
-	     GvHV(sv) && SvOBJECT(GvHV(sv)) ||
-	     GvIO(sv) && SvOBJECT(GvIO(sv)) ||
-	     GvCV(sv) && SvOBJECT(GvCV(sv)) )
+	     (GvAV(sv) && SvOBJECT(GvAV(sv))) ||
+	     (GvHV(sv) && SvOBJECT(GvHV(sv))) ||
+	     (GvIO(sv) && SvOBJECT(GvIO(sv))) ||
+	     (GvCV(sv) && SvOBJECT(GvCV(sv))) )
 	{
 	    DEBUG_D((PerlIO_printf(Perl_debug_log, "Cleaning named glob object:\n "), sv_dump(sv));)
 	    SvREFCNT_dec(sv);
diff --git a/sv.h b/sv.h
index e5832040f8..245199fbfc 100644
--- a/sv.h
+++ b/sv.h
@@ -511,19 +511,19 @@ Set the length of the string which is in the SV.  See C<SvCUR>.
 
 #define SvOKp(sv)		(SvFLAGS(sv) & (SVp_IOK|SVp_NOK|SVp_POK))
 #define SvIOKp(sv)		(SvFLAGS(sv) & SVp_IOK)
-#define SvIOKp_on(sv)		(SvOOK_off(sv), SvFLAGS(sv) |= SVp_IOK)
+#define SvIOKp_on(sv)		((void)SvOOK_off(sv), SvFLAGS(sv) |= SVp_IOK)
 #define SvNOKp(sv)		(SvFLAGS(sv) & SVp_NOK)
 #define SvNOKp_on(sv)		(SvFLAGS(sv) |= SVp_NOK)
 #define SvPOKp(sv)		(SvFLAGS(sv) & SVp_POK)
 #define SvPOKp_on(sv)		(SvFLAGS(sv) |= SVp_POK)
 
 #define SvIOK(sv)		(SvFLAGS(sv) & SVf_IOK)
-#define SvIOK_on(sv)		(SvOOK_off(sv), \
+#define SvIOK_on(sv)		((void)SvOOK_off(sv), \
 				    SvFLAGS(sv) |= (SVf_IOK|SVp_IOK))
 #define SvIOK_off(sv)		(SvFLAGS(sv) &= ~(SVf_IOK|SVp_IOK|SVf_IVisUV))
-#define SvIOK_only(sv)		(SvOK_off(sv), \
+#define SvIOK_only(sv)		((void)SvOK_off(sv), \
 				    SvFLAGS(sv) |= (SVf_IOK|SVp_IOK))
-#define SvIOK_only_UV(sv)	(SvOK_off_exc_UV(sv), \
+#define SvIOK_only_UV(sv)	((void)SvOK_off_exc_UV(sv), \
 				    SvFLAGS(sv) |= (SVf_IOK|SVp_IOK))
 
 #define SvIOK_UV(sv)		((SvFLAGS(sv) & (SVf_IOK|SVf_IVisUV))	\
@@ -538,7 +538,7 @@ Set the length of the string which is in the SV.  See C<SvCUR>.
 #define SvNOK(sv)		(SvFLAGS(sv) & SVf_NOK)
 #define SvNOK_on(sv)		(SvFLAGS(sv) |= (SVf_NOK|SVp_NOK))
 #define SvNOK_off(sv)		(SvFLAGS(sv) &= ~(SVf_NOK|SVp_NOK))
-#define SvNOK_only(sv)		(SvOK_off(sv), \
+#define SvNOK_only(sv)		((void)SvOK_off(sv), \
 				    SvFLAGS(sv) |= (SVf_NOK|SVp_NOK))
 
 #define SvUTF8(sv)		(SvFLAGS(sv) & SVf_UTF8)
@@ -556,7 +556,7 @@ Set the length of the string which is in the SV.  See C<SvCUR>.
 				    SvFLAGS(sv) |= (SVf_POK|SVp_POK))
 
 #define SvOOK(sv)		(SvFLAGS(sv) & SVf_OOK)
-#define SvOOK_on(sv)		(SvIOK_off(sv), SvFLAGS(sv) |= SVf_OOK)
+#define SvOOK_on(sv)		((void)SvIOK_off(sv), SvFLAGS(sv) |= SVf_OOK)
 #define SvOOK_off(sv)		(SvOOK(sv) && sv_backoff(sv))
 
 #define SvFAKE(sv)		(SvFLAGS(sv) & SVf_FAKE)
diff --git a/toke.c b/toke.c
index 5449c2feb2..322e194c54 100644
--- a/toke.c
+++ b/toke.c
@@ -319,6 +319,7 @@ S_cr_textfilter(pTHX_ int idx, SV *sv, int maxlen)
 }
 #endif
 
+#if 0
 STATIC I32
 S_utf16_textfilter(pTHX_ int idx, SV *sv, int maxlen)
 {
@@ -329,7 +330,6 @@ S_utf16_textfilter(pTHX_ int idx, SV *sv, int maxlen)
 	New(898, tmps, SvCUR(sv) * 3 / 2 + 1, U8);
 	tend = utf16_to_utf8((U16*)SvPVX(sv), tmps, SvCUR(sv));
 	sv_usepvn(sv, (char*)tmps, tend - tmps);
-    
     }
     return count;
 }
@@ -344,10 +344,10 @@ S_utf16rev_textfilter(pTHX_ int idx, SV *sv, int maxlen)
 	New(898, tmps, SvCUR(sv) * 3 / 2 + 1, U8);
 	tend = utf16_to_utf8_reversed((U16*)SvPVX(sv), tmps, SvCUR(sv));
 	sv_usepvn(sv, (char*)tmps, tend - tmps);
-    
     }
     return count;
 }
+#endif
 
 /*
  * Perl_lex_start
@@ -861,7 +861,7 @@ S_force_version(pTHX_ char *s)
             version = yylval.opval;
 	    ver = cSVOPx(version)->op_sv;
 	    if (SvPOK(ver) && !SvNIOK(ver)) {
-		SvUPGRADE(ver, SVt_PVNV);
+		(void)SvUPGRADE(ver, SVt_PVNV);
 		SvNVX(ver) = str_to_version(ver);
 		SvNOK_on(ver);		/* hint that it is a version */
 	    }
@@ -1269,8 +1269,10 @@ S_scan_const(pTHX_ char *start)
 	    if (s[2] == '#') {
 		while (s < send && *s != ')')
 		    *d++ = *s++;
-	    } else if (s[2] == '{' /* This should match regcomp.c */
-		       || (s[2] == 'p' || s[2] == '?') && s[3] == '{') {	
+	    }
+	    else if (s[2] == '{' /* This should match regcomp.c */
+		     || ((s[2] == 'p' || s[2] == '?') && s[3] == '{'))
+	    {
 		I32 count = 1;
 		char *regparse = s + (s[2] == '{' ? 3 : 4);
 		char c;
@@ -1464,12 +1466,9 @@ S_scan_const(pTHX_ char *start)
  		++s;
  		if (*s == '{') {
  		    char* e = strchr(s, '}');
- 		    HV *hv;
- 		    SV **svp;
- 		    SV *res, *cv;
+ 		    SV *res;
  		    STRLEN len;
  		    char *str;
- 		    char *why = Nullch;
  
  		    if (!e) {
 			yyerror("Missing right brace on \\N{}");
@@ -2613,8 +2612,8 @@ Perl_yylex(pTHX)
 			    }
 			    d = moreswitches(d);
 			} while (d);
-			if (PERLDB_LINE && !oldpdb ||
-			    ( PL_minus_n || PL_minus_p ) && !(oldn || oldp) )
+			if ((PERLDB_LINE && !oldpdb) ||
+			    ((PL_minus_n || PL_minus_p) && !(oldn || oldp)))
 			      /* if we have already added "LINE: while (<>) {",
 			         we must not do it again */
 			{
@@ -3336,7 +3335,7 @@ Perl_yylex(pTHX)
 	    else if (isIDFIRST_lazy_if(s,UTF)) {
 		char tmpbuf[sizeof PL_tokenbuf];
 		scan_word(s, tmpbuf, sizeof tmpbuf, TRUE, &len);
-		if (tmp = keyword(tmpbuf, len)) {
+		if ((tmp = keyword(tmpbuf, len))) {
 		    /* binary operators exclude handle interpretations */
 		    switch (tmp) {
 		    case -KEY_x:
@@ -3578,7 +3577,6 @@ Perl_yylex(pTHX)
     case 'z': case 'Z':
 
       keylookup: {
-	STRLEN n_a;
 	gv = Nullgv;
 	gvp = 0;
 
@@ -3586,10 +3584,10 @@ Perl_yylex(pTHX)
 	s = scan_word(s, PL_tokenbuf, sizeof PL_tokenbuf, FALSE, &len);
 
 	/* Some keywords can be followed by any delimiter, including ':' */
-	tmp = (len == 1 && strchr("msyq", PL_tokenbuf[0]) ||
-	       len == 2 && ((PL_tokenbuf[0] == 't' && PL_tokenbuf[1] == 'r') ||
-			    (PL_tokenbuf[0] == 'q' &&
-			     strchr("qwxr", PL_tokenbuf[1]))));
+	tmp = ((len == 1 && strchr("msyq", PL_tokenbuf[0])) ||
+	       (len == 2 && ((PL_tokenbuf[0] == 't' && PL_tokenbuf[1] == 'r') ||
+			     (PL_tokenbuf[0] == 'q' &&
+			      strchr("qwxr", PL_tokenbuf[1])))));
 
 	/* x::* is just a word, unless x is "CORE" */
 	if (!tmp && *s == ':' && s[1] == ':' && strNE(PL_tokenbuf, "CORE"))
@@ -3672,7 +3670,7 @@ Perl_yylex(pTHX)
 
 		/* Get the rest if it looks like a package qualifier */
 
-		if (*s == '\'' || *s == ':' && s[1] == ':') {
+		if (*s == '\'' || (*s == ':' && s[1] == ':')) {
 		    STRLEN morelen;
 		    s = scan_word(s, PL_tokenbuf + len, sizeof PL_tokenbuf - len,
 				  TRUE, &morelen);
@@ -5852,7 +5850,7 @@ S_scan_ident(pTHX_ register char *s, register char *send, char *dest, STRLEN des
 	    d++;
 	    if (UTF) {
 		e = s;
-		while (e < send && isALNUM_lazy_if(e,UTF) || *e == ':') {
+		while ((e < send && isALNUM_lazy_if(e,UTF)) || *e == ':') {
 		    e += UTF8SKIP(e);
 		    while (e < send && *e & 0x80 && is_utf8_mark((U8*)e))
 			e += UTF8SKIP(e);
diff --git a/universal.c b/universal.c
index 0e5a89b2c0..f6b25a4d33 100644
--- a/universal.c
+++ b/universal.c
@@ -86,7 +86,6 @@ for class names as well as for objects.
 bool
 Perl_sv_derived_from(pTHX_ SV *sv, const char *name)
 {
-    SV *rv;
     char *type;
     HV *stash;
   
@@ -110,7 +109,6 @@ Perl_sv_derived_from(pTHX_ SV *sv, const char *name)
             (stash && isa_lookup(stash, name, strlen(name), 0) == &PL_sv_yes)
         ? TRUE
         : FALSE ;
- 
 }
 
 void XS_UNIVERSAL_isa(pTHXo_ CV *cv);
@@ -250,7 +248,7 @@ XS(XS_UNIVERSAL_VERSION)
 		}
 		/* they said C<use Foo 1.002_003> and $Foo::VERSION
 		 * doesn't look like a float: force numeric compare */
-		SvUPGRADE(sv, SVt_PVNV);
+		(void)SvUPGRADE(sv, SVt_PVNV);
 		SvNVX(sv) = str_to_version(sv);
 		SvPOK_off(sv);
 		SvNOK_on(sv);
diff --git a/util.c b/util.c
index 091e162e69..4b0e1c57aa 100644
--- a/util.c
+++ b/util.c
@@ -154,7 +154,9 @@ Perl_safesysrealloc(Malloc_t where,MEM_SIZE size)
 Free_t
 Perl_safesysfree(Malloc_t where)
 {
+#ifdef PERL_IMPLICIT_SYS
     dTHX;
+#endif
     DEBUG_m( PerlIO_printf(Perl_debug_log, "0x%"UVxf": (%05ld) free\n",PTR2UV(where),(long)PL_an++));
     if (where) {
 	/*SUPPRESS 701*/
@@ -699,8 +701,8 @@ Perl_init_i18nl10n(pTHX_ int printwarn)
     if (setlocale_failure) {
 	char *p;
 	bool locwarn = (printwarn > 1 || 
-			printwarn &&
-			(!(p = PerlEnv_getenv("PERL_BADLANG")) || atoi(p)));
+			(printwarn &&
+			 (!(p = PerlEnv_getenv("PERL_BADLANG")) || atoi(p))));
 
 	if (locwarn) {
 #ifdef LC_ALL
@@ -995,17 +997,15 @@ Perl_fbm_instr(pTHX_ unsigned char *big, register unsigned char *bigend, SV *lit
     register I32 multiline = flags & FBMrf_MULTILINE;
 
     if (bigend - big < littlelen) {
-      check_tail:
 	if ( SvTAIL(littlestr) 
 	     && (bigend - big == littlelen - 1)
 	     && (littlelen == 1 
-		 || *big == *little && memEQ(big, little, littlelen - 1)))
+		 || (*big == *little && memEQ(big, little, littlelen - 1))))
 	    return (char*)big;
 	return Nullch;
     }
 
     if (littlelen <= 2) {		/* Special-cased */
-	register char c;
 
 	if (littlelen == 1) {
 	    if (SvTAIL(littlestr) && !multiline) { /* Anchor only! */
@@ -1157,7 +1157,6 @@ Perl_fbm_instr(pTHX_ unsigned char *big, register unsigned char *bigend, SV *lit
 		while (tmp--) {
 		    if (*--s == *--little)
 			continue;
-		  differ:
 		    s = olds + 1;	/* here we pay the price for failure */
 		    little = oldlittle;
 		    if (s < bigend)	/* fake up continue to outer loop */
@@ -2356,7 +2355,7 @@ Perl_my_popen(pTHX_ char *cmd, char *mode)
 	}
 #endif	/* defined OS2 */
 	/*SUPPRESS 560*/
-	if (tmpgv = gv_fetchpv("$",TRUE, SVt_PV))
+	if ((tmpgv = gv_fetchpv("$",TRUE, SVt_PV)))
 	    sv_setiv(GvSV(tmpgv), PerlProc_getpid());
 	PL_forkprocess = 0;
 	hv_clear(PL_pidstatus);	/* we have no children */
@@ -2651,7 +2650,7 @@ Perl_wait4pid(pTHX_ Pid_t pid, int *statusp, int flags)
 	HE *entry;
 
 	hv_iterinit(PL_pidstatus);
-	if (entry = hv_iternext(PL_pidstatus)) {
+	if ((entry = hv_iternext(PL_pidstatus))) {
 	    pid = atoi(hv_iterkey(entry,(I32*)statusp));
 	    sv = hv_iterval(PL_pidstatus,entry);
 	    *statusp = SvIVX(sv);
diff --git a/xsutils.c b/xsutils.c
index 0999f744a0..02fab51203 100644
--- a/xsutils.c
+++ b/xsutils.c
@@ -48,7 +48,7 @@ modify_SV_attributes(pTHXo_ SV *sv, SV **retlist, SV **attrlist, int numattrs)
 
     for (nret = 0 ; numattrs && (attr = *attrlist++); numattrs--) {
 	name = SvPV(attr, len);
-	if (negated = (*name == '-')) {
+	if ((negated = (*name == '-'))) {
 	    name++;
 	    len--;
 	}
@@ -271,7 +271,6 @@ usage:
 XS(XS_attributes__warn_reserved)
 {
     dXSARGS;
-    SV *rv, *sv;
 #ifdef dXSTARGET
     dXSTARGET;
 #else