Integrate:

[ 24689]
Subject: [PATCH] Random consting
Message-ID: <20050602171943.GA16553@petdance.com>
p4raw-link: @24689 on //depot/perl: b464bac0b70c4876af1296864220315edde8461d

p4raw-id: //depot/maint-5.8/perl@25508
p4raw-edited: from //depot/perl@24689 'edit in' embed.fnc sv.c
	(@24682..)
p4raw-integrated: from //depot/perl@24689 'copy in' malloc.c (@24666..)
	'edit in' pp_ctl.c (@24642..) pp_hot.c (@24670..) hv.c
	(@24676..) 'ignore' global.sym (@24619..) proto.h (@24682..)
	'merge in' embed.h (@24605..) dump.c (@24619..) perlio.c
	(@24622..) doio.c (@24666..) gv.c util.c (@24669..) pp_sys.c
	(@24670..) perl.c (@24674..) toke.c (@24677..)

16 files changed, 112 insertions, 92 deletions

diff --git a/doio.c b/doio.c
index c8682b4e13..58cbd9565b 100644
--- a/doio.c
+++ b/doio.c
@@ -102,7 +102,7 @@ Perl_do_openn(pTHX_ GV *gv, register char *name, I32 len, int as_raw,
     /* Collect default raw/crlf info from the op */
     if (PL_op && PL_op->op_type == OP_OPEN) {
 	/* set up IO layers */
-	U8 flags = PL_op->op_private;
+	const U8 flags = PL_op->op_private;
 	in_raw = (flags & OPpOPEN_IN_RAW);
 	in_crlf = (flags & OPpOPEN_IN_CRLF);
 	out_raw = (flags & OPpOPEN_OUT_RAW);
@@ -1991,7 +1991,8 @@ Perl_do_ipcctl(pTHX_ I32 optype, SV **mark, SV **sp)
 {
     SV *astr;
     char *a;
-    I32 infosize, getinfo;
+    STRLEN infosize;
+    I32 getinfo;
     I32 ret = -1;
     const I32 id  = SvIVx(*++mark);
     const I32 n   = (optype == OP_SEMCTL) ? SvIVx(*++mark) : 0;
diff --git a/dump.c b/dump.c
index ea1a596cd2..2a726f9648 100644
--- a/dump.c
+++ b/dump.c
@@ -78,7 +78,7 @@ Perl_dump_packsubs(pTHX_ HV *stash)
 void
 Perl_dump_sub(pTHX_ GV *gv)
 {
-    SV *sv = sv_newmortal();
+    SV * const sv = sv_newmortal();
 
     gv_fullname3(sv, gv, Nullch);
     Perl_dump_indent(aTHX_ 0, Perl_debug_log, "\nSUB %s = ", SvPVX_const(sv));
@@ -95,7 +95,7 @@ Perl_dump_sub(pTHX_ GV *gv)
 void
 Perl_dump_form(pTHX_ GV *gv)
 {
-    SV *sv = sv_newmortal();
+    SV * const sv = sv_newmortal();
 
     gv_fullname3(sv, gv, Nullch);
     Perl_dump_indent(aTHX_ 0, Perl_debug_log, "\nFORMAT %s = ", SvPVX_const(sv));
@@ -1493,8 +1493,8 @@ Perl_debop(pTHX_ OP *o)
 	CV *cv = deb_curcv(cxstack_ix);
 	SV *sv;
         if (cv) {
-            AV *padlist = CvPADLIST(cv);
-            AV *comppad = (AV*)(*av_fetch(padlist, 0, FALSE));
+            AV * const padlist = CvPADLIST(cv);
+            AV * const comppad = (AV*)(*av_fetch(padlist, 0, FALSE));
             sv = *av_fetch(comppad, o->op_targ, FALSE);
         } else
             sv = Nullsv;
diff --git a/embed.fnc b/embed.fnc
index 3df379b8f1..48fa17ddbe 100644
--- a/embed.fnc
+++ b/embed.fnc
@@ -24,9 +24,8 @@
 :	b		binary backward compatibility; function is a macro
 :			but has also Perl_ implementation (which is exported)
 :	U		suppress usage example in autogenerated documentation
-:	a		allocates memory a la malloc/calloc
-:	R		Return value must not be ignored.  All "a" functions
-:			get this automatically.
+:	a		allocates memory a la malloc/calloc.  Is also "R".
+:	R		Return value must not be ignored.
 :	P		pure function: no effects except the return value;
 :			return value depends only on parms and/or globals
 :
@@ -72,7 +71,7 @@ Aanop	|Malloc_t|calloc	|MEM_SIZE elements|MEM_SIZE size
 Aanop	|Malloc_t|realloc	|Malloc_t where|MEM_SIZE nbytes
 Anop	|Free_t	|mfree		|Malloc_t where
 #if defined(MYMALLOC)
-np	|MEM_SIZE|malloced_size	|void *p
+npR	|MEM_SIZE|malloced_size	|void *p
 #endif
 
 Anp	|void*	|get_context
@@ -317,9 +316,9 @@ p	|void	|init_debugger
 Ap	|void	|init_stacks
 Ap	|void	|init_tm	|struct tm *ptm
 pd	|U32	|intro_my
-ApP	|char*	|instr		|NN const char* big|NN const char* little
-p	|bool	|io_close	|IO* io|bool not_implicit
-p	|OP*	|invert		|OP* cmd
+ApPR	|char*	|instr		|NN const char* big|NN const char* little
+pR	|bool	|io_close	|NN IO* io|bool not_implicit
+pR	|OP*	|invert		|OP* cmd
 dpR	|bool	|is_gv_magical	|char *name|STRLEN len|U32 flags
 ApR	|I32	|is_lvalue_sub
 ApPR	|U32	|to_uni_upper_lc|U32 c
@@ -776,8 +775,8 @@ Apd	|SV*	|sv_mortalcopy	|NN SV* oldsv
 ApdR	|SV*	|sv_newmortal
 Apd	|SV*	|sv_newref	|SV* sv
 Ap	|char*	|sv_peek	|SV* sv
-Apd	|void	|sv_pos_u2b	|SV* sv|I32* offsetp|I32* lenp
-Apd	|void	|sv_pos_b2u	|SV* sv|I32* offsetp
+Apd	|void	|sv_pos_u2b	|SV* sv|NN I32* offsetp|I32* lenp
+Apd	|void	|sv_pos_b2u	|SV* sv|NN I32* offsetp
 Amdb	|char*	|sv_pvn_force	|SV* sv|STRLEN* lp
 Apd	|char*	|sv_pvutf8n_force|SV* sv|STRLEN* lp
 Apd	|char*	|sv_pvbyten_force|SV* sv|STRLEN* lp
@@ -1020,7 +1019,7 @@ sR	|HE*	|new_he
 s	|void	|del_he		|NN HE *p
 sR	|HEK*	|save_hek_flags	|NN const char *str|I32 len|U32 hash|int flags
 s	|void	|hv_magic_check	|NN HV *hv|NN bool *needs_copy|NN bool *needs_store
-s	|void	|unshare_hek_or_pvn|HEK* hek|NN const char* sv|I32 len|U32 hash
+s	|void	|unshare_hek_or_pvn|HEK* hek|const char* str|I32 len|U32 hash
 sR	|HEK*	|share_hek_flags|const char* sv|I32 len|U32 hash|int flags
 rs	|void	|hv_notallowed	|int flags|NN const char *key|I32 klen|NN const char *msg
 #endif
@@ -1138,10 +1137,10 @@ s	|SV*	|method_common	|SV* meth|U32* hashp
 #endif
 
 #if defined(PERL_IN_PP_SYS_C) || defined(PERL_DECL_PROT)
-s	|OP*	|doform		|CV *cv|GV *gv|OP *retop
-s	|int	|emulate_eaccess|const char* path|Mode_t mode
+s	|OP*	|doform		|NN CV *cv|NN GV *gv|NN OP *retop
+sr	|int	|emulate_eaccess|NN const char* path|Mode_t mode
 #  if !defined(HAS_MKDIR) || !defined(HAS_RMDIR)
-s	|int	|dooneliner	|char *cmd|char *filename
+sR	|int	|dooneliner	|NN const char *cmd|NN const char *filename
 #  endif
 #endif
 
@@ -1417,13 +1416,13 @@ p	|int	|get_debug_opts	|char **s
 
 
 
-Apd	|void	|hv_clear_placeholders|HV* hb
+Apd	|void	|hv_clear_placeholders|NN HV* hb
 
 #if defined(PERL_IN_HV_C) || defined(PERL_DECL_PROT)
 sM	|SV*	|hv_delete_common|HV* tb|SV* key_sv|const char* key|STRLEN klen|int k_flags|I32 d_flags|U32 hash
 sM	|HE*	|hv_fetch_common|HV* tb|SV* key_sv|const char* key|STRLEN klen|int flags|int action|SV* val|U32 hash
 #endif
-Apd	|SV*	|hv_scalar	|HV* hv|
+ApdR	|SV*	|hv_scalar	|NN HV* hv|
 p	|SV*	|magic_scalarpack|HV* hv|MAGIC*	mg
 
 #if defined(DEBUGGING)
diff --git a/global.sym b/global.sym
index d5a9154bb9..80ff9dd6d4 100644
--- a/global.sym
+++ b/global.sym
@@ -212,9 +212,8 @@ Perl_is_uni_print_lc
 Perl_is_uni_punct_lc
 Perl_is_uni_xdigit_lc
 Perl_is_utf8_char
-Perl_is_utf8_string
 Perl_is_utf8_string_loc
-Perl_is_utf8_string_loclen
+Perl_is_utf8_string
 Perl_is_utf8_alnum
 Perl_is_utf8_alnumc
 Perl_is_utf8_idfirst
@@ -715,4 +714,5 @@ Perl_ck_substr
 Perl_ck_svconst
 Perl_ck_trunc
 Perl_ck_unpack
+Perl_is_utf8_string_loclen
 # ex: set ro:
diff --git a/gv.c b/gv.c
index baad7e629d..71c34be362 100644
--- a/gv.c
+++ b/gv.c
@@ -862,7 +862,7 @@ Perl_gv_fetchpv(pTHX_ const char *nambeg, I32 add, I32 sv_type)
 	} else
 #endif
 	{
-	    const char *name2 = name + 1;
+	    const char * const name2 = name + 1;
 	    switch (*name) {
 	    case 'A':
 		if (strEQ(name2, "RGV")) {
@@ -1182,8 +1182,7 @@ Perl_newIO(pTHX)
     sv_upgrade((SV *)io,SVt_PVIO);
     SvREFCNT(io) = 1;
     SvOBJECT_on(io);
-    /* Clear the stashcache because a new IO could overrule a
-       package name */
+    /* Clear the stashcache because a new IO could overrule a package name */
     hv_clear(PL_stashcache);
     iogv = gv_fetchpv("FileHandle::", FALSE, SVt_PVHV);
     /* unless exists($main::{FileHandle}) and defined(%main::FileHandle::) */
@@ -1419,7 +1418,7 @@ Perl_Gv_AMupdate(pTHX_ HV *stash)
 		{
 		    /* Can be an import stub (created by "can"). */
 		    SV *gvsv = GvSV(gv);
-		    const char *name = SvPOK(gvsv) ?  SvPVX_const(gvsv) : "???";
+		    const char * const name = SvPOK(gvsv) ?  SvPVX_const(gvsv) : "???";
 		    Perl_croak(aTHX_ "%s method \"%.256s\" overloading \"%s\" "\
 				"in package \"%.256s\"",
 			       (GvCVGEN(gv) ? "Stub found while resolving"
@@ -1428,8 +1427,7 @@ Perl_Gv_AMupdate(pTHX_ HV *stash)
 		}
 		cv = GvCV(gv = ngv);
 	    }
-	    DEBUG_o( Perl_deb(aTHX_ "Overloading \"%s\" in package \"%.256s\" "\
-	                            "via \"%.256s::%.256s\"\n",
+	    DEBUG_o( Perl_deb(aTHX_ "Overloading \"%s\" in package \"%.256s\" via \"%.256s::%.256s\"\n",
 			 cp, HvNAME_get(stash), HvNAME_get(GvSTASH(CvGV(cv))),
 			 GvNAME(CvGV(cv))) );
 	    filled = 1;
@@ -1503,8 +1501,10 @@ Perl_amagic_call(pTHX_ SV *left, SV *right, int method, int flags)
   CV *cv=NULL;
   CV **cvp=NULL, **ocvp=NULL;
   AMT *amtp=NULL, *oamtp=NULL;
-  int off=0, off1, lr=0, assign=AMGf_assign & flags, notfound=0;
-  int postpr = 0, force_cpy = 0, assignshift = assign ? 1 : 0;
+  int off = 0, off1, lr = 0, notfound = 0;
+  int postpr = 0, force_cpy = 0;
+  int assign = AMGf_assign & flags;
+  const int assignshift = assign ? 1 : 0;
 #ifdef DEBUGGING
   int fl=0;
 #endif
@@ -1862,7 +1862,7 @@ Perl_is_gv_magical(pTHX_ char *name, STRLEN len, U32 flags)
 {
     (void)flags;
     if (len > 1) {
-	const char *name1 = name + 1;
+	const char * const name1 = name + 1;
 	switch (*name) {
 	case 'I':
 	    if (len == 3 && name1[1] == 'S' && name[2] == 'A')
diff --git a/hv.c b/hv.c
index 5ae011abca..10d5658f7d 100644
--- a/hv.c
+++ b/hv.c
@@ -967,8 +967,8 @@ S_hv_delete_common(pTHX_ HV *hv, SV *keysv, const char *key, STRLEN klen,
 	return Nullsv;
 
     if (is_utf8) {
-    const char *keysave = key;
-    key = (char*)bytes_from_utf8((U8*)key, &klen, &is_utf8);
+	const char *keysave = key;
+	key = (char*)bytes_from_utf8((U8*)key, &klen, &is_utf8);
 
         if (is_utf8)
             k_flags |= HVhek_UTF8;
@@ -1470,8 +1470,8 @@ Perl_hv_clear(pTHX_ HV *hv)
 
     if (SvREADONLY(hv) && xhv->xhv_array != NULL) {
 	/* restricted hash: convert all keys to placeholders */
-	I32 i;
-	for (i = 0; i <= (I32) xhv->xhv_max; i++) {
+	STRLEN i;
+	for (i = 0; i <= xhv->xhv_max; i++) {
 	    HE *entry = ((HE**)xhv->xhv_array)[i];
 	    for (; entry; entry = HeNEXT(entry)) {
 		/* not already placeholder */
@@ -1524,11 +1524,12 @@ void
 Perl_hv_clear_placeholders(pTHX_ HV *hv)
 {
     I32 items = (I32)HvPLACEHOLDERS_get(hv);
-    I32 i = HvMAX(hv);
+    I32 i;
 
     if (items == 0)
 	return;
 
+    i = HvMAX(hv);
     do {
 	/* Loop down the linked list heads  */
 	bool first = 1;
diff --git a/malloc.c b/malloc.c
index 05c0528e39..521248ab6d 100644
--- a/malloc.c
+++ b/malloc.c
@@ -1337,7 +1337,7 @@ fill_pat_4bytes(unsigned char *s, size_t nbytes, const unsigned char *fill)
 {
     unsigned char *e = s + nbytes;
     long *lp;
-    long lfill = *(long*)fill;
+    const long lfill = *(long*)fill;
 
     if (PTR2UV(s) & (sizeof(long)-1)) {		/* Align the pattern */
 	int shift = sizeof(long) - (PTR2UV(s) & (sizeof(long)-1));
@@ -1378,7 +1378,7 @@ cmp_pat_4bytes(unsigned char *s, size_t nbytes, const unsigned char *fill)
 {
     unsigned char *e = s + nbytes;
     long *lp;
-    long lfill = *(long*)fill;
+    const long lfill = *(long*)fill;
 
     if (PTR2UV(s) & (sizeof(long)-1)) {		/* Align the pattern */
 	int shift = sizeof(long) - (PTR2UV(s) & (sizeof(long)-1));
@@ -2357,12 +2357,12 @@ Perl_malloced_size(void *p)
 {
     union overhead *ovp = (union overhead *)
 	((caddr_t)p - sizeof (union overhead) * CHUNK_SHIFT);
-    int bucket = OV_INDEX(ovp);
+    const int bucket = OV_INDEX(ovp);
 #ifdef RCHECK
     /* The caller wants to have a complete control over the chunk,
        disable the memory checking inside the chunk.  */
     if (bucket <= MAX_SHORT_BUCKET) {
-	MEM_SIZE size = BUCKET_SIZE_REAL(bucket);
+	const MEM_SIZE size = BUCKET_SIZE_REAL(bucket);
 	ovp->ov_size = size + M_OVERHEAD - 1;
 	*((u_int *)((caddr_t)ovp + size + M_OVERHEAD - RMAGIC_SZ)) = RMAGIC;
     }
diff --git a/perl.c b/perl.c
index 5da9861431..89ba116ec8 100644
--- a/perl.c
+++ b/perl.c
@@ -2379,7 +2379,6 @@ Perl_eval_sv(pTHX_ SV *sv, I32 flags)
     UNOP myop;		/* fake syntax tree node */
     volatile I32 oldmark = SP - PL_stack_base;
     volatile I32 retval = 0;
-    I32 oldscope;
     int ret;
     OP* oldop = PL_op;
     dJMPENV;
@@ -2394,7 +2393,6 @@ Perl_eval_sv(pTHX_ SV *sv, I32 flags)
     Zero(PL_op, 1, UNOP);
     EXTEND(PL_stack_sp, 1);
     *++PL_stack_sp = sv;
-    oldscope = PL_scopestack_ix;
 
     if (!(flags & G_NOARGS))
 	myop.op_flags = OPf_STACKED;
diff --git a/perlio.c b/perlio.c
index ff98c772e6..39ffda7058 100644
--- a/perlio.c
+++ b/perlio.c
@@ -1160,7 +1160,7 @@ PerlIO_push(pTHX_ PerlIO *f, PERLIO_FUNCS_DECL(*tab), const char *mode, SV *arg)
 	Perl_croak(aTHX_ "Layer does not match this perl");
     }
     if (tab->size) {
-	PerlIOl *l = NULL;
+	PerlIOl *l;
 	if (tab->size < sizeof(PerlIOl)) {
 	    goto mismatch;
 	}
@@ -2504,7 +2504,7 @@ PerlIOUnix_read(pTHX_ PerlIO *f, void *vbuf, Size_t count)
 	return 0;
     }
     while (1) {
-	SSize_t len = PerlLIO_read(fd, vbuf, count);
+	const SSize_t len = PerlLIO_read(fd, vbuf, count);
 	if (len >= 0 || errno != EINTR) {
 	    if (len < 0) {
 		if (errno != EAGAIN) {
@@ -2519,6 +2519,7 @@ PerlIOUnix_read(pTHX_ PerlIO *f, void *vbuf, Size_t count)
 	}
 	PERL_ASYNC_CHECK();
     }
+    /*NOTREACHED*/
 }
 
 SSize_t
diff --git a/pp_ctl.c b/pp_ctl.c
index a83a461b8c..4b5b92088f 100644
--- a/pp_ctl.c
+++ b/pp_ctl.c
@@ -2870,7 +2870,7 @@ S_doeval(pTHX_ int gimme, OP** startop, CV* outside, U32 seq)
 	lex_end();
 	LEAVE;
 	if (optype == OP_REQUIRE) {
-            const char* msg = SvPVx(ERRSV, n_a);
+            const char* const msg = SvPVx(ERRSV, n_a);
 	    DIE(aTHX_ "%sCompilation failed in require",
 		*msg ? msg : "Unknown error\n");
 	}
diff --git a/pp_hot.c b/pp_hot.c
index 7d28d333a7..8e31716cb4 100644
--- a/pp_hot.c
+++ b/pp_hot.c
@@ -1355,7 +1355,6 @@ play_it_again:
     if (gimme == G_ARRAY) {
 	const I32 nparens = rx->nparens;
 	I32 i = (global && !nparens) ? 1 : 0;
-	I32 len;
 
 	SPAGAIN;			/* EVAL blocks could move the stack. */
 	EXTEND(SP, nparens + i);
@@ -1364,7 +1363,7 @@ play_it_again:
 	    PUSHs(sv_newmortal());
 	    /*SUPPRESS 560*/
 	    if ((rx->startp[i] != -1) && rx->endp[i] != -1 ) {
-		len = rx->endp[i] - rx->startp[i];
+		const I32 len = rx->endp[i] - rx->startp[i];
 		s = rx->startp[i] + truebase;
 	        if (rx->endp[i] < 0 || rx->startp[i] < 0 ||
 		    len < 0 || len > strend - s)
@@ -3145,8 +3144,7 @@ S_method_common(pTHX_ SV* meth, U32* hashp)
 	packname = Nullch;
 
         if(SvOK(sv) && (packname = SvPV(sv, packlen))) {
-          HE* he;
-	  he = hv_fetch_ent(PL_stashcache, sv, 0, 0);
+          const HE* const he = hv_fetch_ent(PL_stashcache, sv, 0, 0);
           if (he) { 
             stash = INT2PTR(HV*,SvIV(HeVAL(he)));
             goto fetch;
@@ -3200,7 +3198,7 @@ S_method_common(pTHX_ SV* meth, U32* hashp)
 
     /* shortcut for simple names */
     if (hashp) {
-	HE* he = hv_fetch_ent(stash, meth, 0, *hashp);
+	const HE* const he = hv_fetch_ent(stash, meth, 0, *hashp);
 	if (he) {
 	    gv = (GV*)HeVAL(he);
 	    if (isGV(gv) && GvCV(gv) &&
diff --git a/pp_sys.c b/pp_sys.c
index 35b1e133d4..7d32b1a6a3 100644
--- a/pp_sys.c
+++ b/pp_sys.c
@@ -1386,7 +1386,7 @@ PP(pp_leavewrite)
 	cv = GvFORM(fgv);
 	if (!cv) {
 	    SV * const sv = sv_newmortal();
-	    char *name;
+	    const char *name;
 	    gv_efullname4(sv, fgv, Nullch, FALSE);
 	    name = SvPV_nolen(sv);
 	    if (name && *name)
@@ -3654,9 +3654,9 @@ PP(pp_readlink)
 
 #if !defined(HAS_MKDIR) || !defined(HAS_RMDIR)
 STATIC int
-S_dooneliner(pTHX_ char *cmd, char *filename)
+S_dooneliner(pTHX_ const char *cmd, const char *filename)
 {
-    char *save_filename = filename;
+    char * const save_filename = filename;
     char *cmdline;
     char *s;
     PerlIO *myfp;
diff --git a/proto.h b/proto.h
index 10c4288a84..d65842b22f 100644
--- a/proto.h
+++ b/proto.h
@@ -57,7 +57,9 @@ PERL_CALLCONV Malloc_t	Perl_realloc(Malloc_t where, MEM_SIZE nbytes)
 
 PERL_CALLCONV Free_t	Perl_mfree(Malloc_t where);
 #if defined(MYMALLOC)
-PERL_CALLCONV MEM_SIZE	Perl_malloced_size(void *p);
+PERL_CALLCONV MEM_SIZE	Perl_malloced_size(void *p)
+			__attribute__warn_unused_result__;
+
 #endif
 
 PERL_CALLCONV void*	Perl_get_context(void);
@@ -465,12 +467,18 @@ PERL_CALLCONV void	Perl_init_stacks(pTHX);
 PERL_CALLCONV void	Perl_init_tm(pTHX_ struct tm *ptm);
 PERL_CALLCONV U32	Perl_intro_my(pTHX);
 PERL_CALLCONV char*	Perl_instr(pTHX_ const char* big, const char* little)
+			__attribute__warn_unused_result__
 			__attribute__pure__
 			__attribute__nonnull__(pTHX_1)
 			__attribute__nonnull__(pTHX_2);
 
-PERL_CALLCONV bool	Perl_io_close(pTHX_ IO* io, bool not_implicit);
-PERL_CALLCONV OP*	Perl_invert(pTHX_ OP* cmd);
+PERL_CALLCONV bool	Perl_io_close(pTHX_ IO* io, bool not_implicit)
+			__attribute__warn_unused_result__
+			__attribute__nonnull__(pTHX_1);
+
+PERL_CALLCONV OP*	Perl_invert(pTHX_ OP* cmd)
+			__attribute__warn_unused_result__;
+
 PERL_CALLCONV bool	Perl_is_gv_magical(pTHX_ char *name, STRLEN len, U32 flags)
 			__attribute__warn_unused_result__;
 
@@ -1488,8 +1496,12 @@ PERL_CALLCONV SV*	Perl_sv_newmortal(pTHX)
 
 PERL_CALLCONV SV*	Perl_sv_newref(pTHX_ SV* sv);
 PERL_CALLCONV char*	Perl_sv_peek(pTHX_ SV* sv);
-PERL_CALLCONV void	Perl_sv_pos_u2b(pTHX_ SV* sv, I32* offsetp, I32* lenp);
-PERL_CALLCONV void	Perl_sv_pos_b2u(pTHX_ SV* sv, I32* offsetp);
+PERL_CALLCONV void	Perl_sv_pos_u2b(pTHX_ SV* sv, I32* offsetp, I32* lenp)
+			__attribute__nonnull__(pTHX_2);
+
+PERL_CALLCONV void	Perl_sv_pos_b2u(pTHX_ SV* sv, I32* offsetp)
+			__attribute__nonnull__(pTHX_2);
+
 /* PERL_CALLCONV char*	sv_pvn_force(pTHX_ SV* sv, STRLEN* lp); */
 PERL_CALLCONV char*	Perl_sv_pvutf8n_force(pTHX_ SV* sv, STRLEN* lp);
 PERL_CALLCONV char*	Perl_sv_pvbyten_force(pTHX_ SV* sv, STRLEN* lp);
@@ -1854,9 +1866,7 @@ STATIC void	S_hv_magic_check(pTHX_ HV *hv, bool *needs_copy, bool *needs_store)
 			__attribute__nonnull__(pTHX_2)
 			__attribute__nonnull__(pTHX_3);
 
-STATIC void	S_unshare_hek_or_pvn(pTHX_ HEK* hek, const char* sv, I32 len, U32 hash)
-			__attribute__nonnull__(pTHX_2);
-
+STATIC void	S_unshare_hek_or_pvn(pTHX_ HEK* hek, const char* str, I32 len, U32 hash);
 STATIC HEK*	S_share_hek_flags(pTHX_ const char* sv, I32 len, U32 hash, int flags)
 			__attribute__warn_unused_result__;
 
@@ -2050,10 +2060,21 @@ STATIC SV*	S_method_common(pTHX_ SV* meth, U32* hashp);
 #endif
 
 #if defined(PERL_IN_PP_SYS_C) || defined(PERL_DECL_PROT)
-STATIC OP*	S_doform(pTHX_ CV *cv, GV *gv, OP *retop);
-STATIC int	S_emulate_eaccess(pTHX_ const char* path, Mode_t mode);
+STATIC OP*	S_doform(pTHX_ CV *cv, GV *gv, OP *retop)
+			__attribute__nonnull__(pTHX_1)
+			__attribute__nonnull__(pTHX_2)
+			__attribute__nonnull__(pTHX_3);
+
+STATIC int	S_emulate_eaccess(pTHX_ const char* path, Mode_t mode)
+			__attribute__noreturn__
+			__attribute__nonnull__(pTHX_1);
+
 #  if !defined(HAS_MKDIR) || !defined(HAS_RMDIR)
-STATIC int	S_dooneliner(pTHX_ char *cmd, char *filename);
+STATIC int	S_dooneliner(pTHX_ const char *cmd, const char *filename)
+			__attribute__warn_unused_result__
+			__attribute__nonnull__(pTHX_1)
+			__attribute__nonnull__(pTHX_2);
+
 #  endif
 #endif
 
@@ -2414,13 +2435,18 @@ PERL_CALLCONV int	Perl_get_debug_opts(pTHX_ char **s);
 
 
 
-PERL_CALLCONV void	Perl_hv_clear_placeholders(pTHX_ HV* hb);
+PERL_CALLCONV void	Perl_hv_clear_placeholders(pTHX_ HV* hb)
+			__attribute__nonnull__(pTHX_1);
+
 
 #if defined(PERL_IN_HV_C) || defined(PERL_DECL_PROT)
 STATIC SV*	S_hv_delete_common(pTHX_ HV* tb, SV* key_sv, const char* key, STRLEN klen, int k_flags, I32 d_flags, U32 hash);
 STATIC HE*	S_hv_fetch_common(pTHX_ HV* tb, SV* key_sv, const char* key, STRLEN klen, int flags, int action, SV* val, U32 hash);
 #endif
-PERL_CALLCONV SV*	Perl_hv_scalar(pTHX_ HV* hv);
+PERL_CALLCONV SV*	Perl_hv_scalar(pTHX_ HV* hv)
+			__attribute__warn_unused_result__
+			__attribute__nonnull__(pTHX_1);
+
 PERL_CALLCONV SV*	Perl_magic_scalarpack(pTHX_ HV* hv, MAGIC*	mg);
 
 #if defined(DEBUGGING)
diff --git a/sv.c b/sv.c
index cab35f5bc5..e16077933d 100644
--- a/sv.c
+++ b/sv.c
@@ -4511,7 +4511,7 @@ Perl_sv_catsv_flags(pTHX_ SV *dsv, register SV *ssv, I32 flags)
 	    dsv->sv_flags doesn't have that bit set.
 		Andy Dougherty  12 Oct 2001
 	*/
-	I32 sutf8 = DO_UTF8(ssv);
+	const I32 sutf8 = DO_UTF8(ssv);
 	I32 dutf8;
 
 	if (SvGMAGICAL(dsv) && (flags & SV_GMAGIC))
@@ -5171,11 +5171,8 @@ Perl_sv_clear(pTHX_ register SV *sv)
     if (SvOBJECT(sv)) {
 	if (PL_defstash) {		/* Still have a symbol table? */
 	    dSP;
-	    CV* destructor;
-
-
-
 	    do {	
+		CV* destructor;
 		stash = SvSTASH(sv);
 		destructor = StashHANDLER(stash,DESTROY);
 		if (destructor) {
@@ -5693,16 +5690,16 @@ void
 Perl_sv_pos_u2b(pTHX_ register SV *sv, I32* offsetp, I32* lenp)
 {
     U8 *start;
-    U8 *s;
     STRLEN len;
-    STRLEN *cache = 0;
-    STRLEN boffset = 0;
 
     if (!sv)
 	return;
 
-    start = s = (U8*)SvPV(sv, len);
+    start = (U8*)SvPV(sv, len);
     if (len) {
+	STRLEN boffset = 0;
+	STRLEN *cache = 0;
+	U8 *s = start;
 	 I32 uoffset = *offsetp;
 	 U8 *send = s + len;
 	 MAGIC *mg = 0;
@@ -7150,12 +7147,7 @@ Note that the perl-level function is vaguely deprecated.
 void
 Perl_sv_reset(pTHX_ register char *s, HV *stash)
 {
-    register HE *entry;
-    register GV *gv;
-    register SV *sv;
-    register I32 i;
     register PMOP *pm;
-    register I32 max;
     char todo[PERL_UCHAR_MAX+1];
 
     if (!stash)
@@ -7175,7 +7167,8 @@ Perl_sv_reset(pTHX_ register char *s, HV *stash)
 
     Zero(todo, 256, char);
     while (*s) {
-	i = (unsigned char)*s;
+	I32 max;
+	I32 i = (unsigned char)*s;
 	if (s[1] == '-') {
 	    s += 2;
 	}
@@ -7184,10 +7177,14 @@ Perl_sv_reset(pTHX_ register char *s, HV *stash)
 	    todo[i] = 1;
 	}
 	for (i = 0; i <= (I32) HvMAX(stash); i++) {
+	    HE *entry;
 	    for (entry = HvARRAY(stash)[i];
 		 entry;
 		 entry = HeNEXT(entry))
 	    {
+		register GV *gv;
+		register SV *sv;
+
 		if (!todo[(U8)*HeKEY(entry)])
 		    continue;
 		gv = (GV*)HeVAL(entry);
@@ -8388,11 +8385,11 @@ F0convert(NV nv, char *endbuf, STRLEN *len)
 {
     const int neg = nv < 0;
     UV uv;
-    char *p = endbuf;
 
     if (neg)
 	nv = -nv;
     if (nv < UV_MAX) {
+	char *p = endbuf;
 	nv += 0.5;
 	uv = (UV)nv;
 	if (uv & 1 && uv == nv)
@@ -8438,8 +8435,8 @@ Perl_sv_vcatpvfn(pTHX_ SV *sv, const char *pat, STRLEN patlen, va_list *args, SV
     I32 svix = 0;
     static char nullstr[] = "(null)";
     SV *argsv = Nullsv;
-    bool has_utf8; /* has the result utf8? */
-    bool pat_utf8; /* the pattern is in utf8? */
+    bool has_utf8 = DO_UTF8(sv);    /* has the result utf8? */
+    const bool pat_utf8 = has_utf8; /* the pattern is in utf8? */
     SV *nsv = Nullsv;
     /* Times 4: a decimal digit takes more than 3 binary digits.
      * NV_DIG: mantissa takes than many decimal digits.
@@ -8448,8 +8445,6 @@ Perl_sv_vcatpvfn(pTHX_ SV *sv, const char *pat, STRLEN patlen, va_list *args, SV
     /* large enough for "%#.#f" --chip */
     /* what about long double NVs? --jhi */
 
-    has_utf8 = pat_utf8 = DO_UTF8(sv);
-
     /* no matter what, this is a string now */
     (void)SvPV_force(sv, origlen);
 
@@ -10525,7 +10520,6 @@ Perl_ss_dup(pTHX_ PerlInterpreter *proto_perl, CLONE_PARAMS* param)
     long longval;
     GP *gp;
     IV iv;
-    I32 i;
     char *c = NULL;
     void (*dptr) (void*);
     void (*dxptr) (pTHX_ void*);
@@ -10534,7 +10528,7 @@ Perl_ss_dup(pTHX_ PerlInterpreter *proto_perl, CLONE_PARAMS* param)
     Newz(54, nss, max, ANY);
 
     while (ix > 0) {
-	i = POPINT(ss,ix);
+	I32 i = POPINT(ss,ix);
 	TOPINT(nss,ix) = i;
 	switch (i) {
 	case SAVEt_ITEM:			/* normal string */
@@ -10884,7 +10878,6 @@ perl_clone_using(PerlInterpreter *proto_perl, UV flags,
      * constants; they need to be allocated as common memory and just
      * their pointers copied. */
 
-    IV i;
     CLONE_PARAMS clone_params;
     CLONE_PARAMS* param = &clone_params;
 
@@ -11115,6 +11108,7 @@ perl_clone_using(PerlInterpreter *proto_perl, UV flags,
     {
 	const I32 len = av_len((AV*)proto_perl->Iregex_padav);
 	SV** regexen = AvARRAY((AV*)proto_perl->Iregex_padav);
+	IV i;
 	av_push(PL_regex_padav,
 		sv_dup_inc(regexen[0],param));
 	for(i = 1; i <= len; i++) {
diff --git a/toke.c b/toke.c
index a9e0136cc6..de02676c85 100644
--- a/toke.c
+++ b/toke.c
@@ -9406,7 +9406,7 @@ S_scan_heredoc(pTHX_ register char *s)
 #ifndef PERL_STRICT_CR
     d = strchr(s, '\r');
     if (d) {
-	char *olds = s;
+	char * const olds = s;
 	s = d;
 	while (s < PL_bufend) {
 	    if (*s == '\r') {
@@ -9454,7 +9454,7 @@ S_scan_heredoc(pTHX_ register char *s)
     if (PL_lex_inwhat == OP_SUBST && PL_in_eval && !PL_rsfp) {
 	char *bufptr = PL_sublex_info.super_bufptr;
 	char *bufend = PL_sublex_info.super_bufend;
-	char *olds = s - SvCUR(herewas);
+	char * const olds = s - SvCUR(herewas);
 	s = strchr(bufptr, '\n');
 	if (!s)
 	    s = bufend;
diff --git a/util.c b/util.c
index 861ae19e16..98e2adc330 100644
--- a/util.c
+++ b/util.c
@@ -3009,6 +3009,8 @@ Perl_set_context(void *t)
     if (pthread_setspecific(PL_thr_key, t))
 	Perl_croak_nocontext("panic: pthread_setspecific");
 #  endif
+#else
+    (void)t;
 #endif
 }