X-Git-Url: https://perl5.git.perl.org/perl5.git/blobdiff_plain/ce6987d0ee9b127be2a1769a57aa5a88de5b51ef..6800c0cf85ac0db6e97c99271c275fdcd4bf4200:/pp_sys.c

diff --git a/pp_sys.c b/pp_sys.c
index 276fa67..ab14c67 100644
--- a/pp_sys.c
+++ b/pp_sys.c
@@ -197,9 +197,7 @@ void setservent(int);
 void endservent(void);
 #endif
 
-#undef PERL_EFF_ACCESS_R_OK	/* EFFective uid/gid ACCESS R_OK */
-#undef PERL_EFF_ACCESS_W_OK
-#undef PERL_EFF_ACCESS_X_OK
+#undef PERL_EFF_ACCESS	/* EFFective uid/gid ACCESS */
 
 /* AIX 5.2 and below use mktime for localtime, and defines the edge case
  * for time 0x7fffffff to be valid only in UTC. AIX 5.3 provides localtime64
@@ -212,38 +210,31 @@ void endservent(void);
 
 /* F_OK unused: if stat() cannot find it... */
 
-#if !defined(PERL_EFF_ACCESS_R_OK) && defined(HAS_ACCESS) && defined(EFF_ONLY_OK) && !defined(NO_EFF_ONLY_OK)
+#if !defined(PERL_EFF_ACCESS) && defined(HAS_ACCESS) && defined(EFF_ONLY_OK) && !defined(NO_EFF_ONLY_OK)
     /* Digital UNIX (when the EFF_ONLY_OK gets fixed), UnixWare */
-#   define PERL_EFF_ACCESS_R_OK(p) (access((p), R_OK | EFF_ONLY_OK))
-#   define PERL_EFF_ACCESS_W_OK(p) (access((p), W_OK | EFF_ONLY_OK))
-#   define PERL_EFF_ACCESS_X_OK(p) (access((p), X_OK | EFF_ONLY_OK))
+#   define PERL_EFF_ACCESS(p,f) (access((p), (f) | EFF_ONLY_OK))
 #endif
 
-#if !defined(PERL_EFF_ACCESS_R_OK) && defined(HAS_EACCESS)
+#if !defined(PERL_EFF_ACCESS) && defined(HAS_EACCESS)
 #   ifdef I_SYS_SECURITY
 #       include <sys/security.h>
 #   endif
 #   ifdef ACC_SELF
         /* HP SecureWare */
-#       define PERL_EFF_ACCESS_R_OK(p) (eaccess((p), R_OK, ACC_SELF))
-#       define PERL_EFF_ACCESS_W_OK(p) (eaccess((p), W_OK, ACC_SELF))
-#       define PERL_EFF_ACCESS_X_OK(p) (eaccess((p), X_OK, ACC_SELF))
+#       define PERL_EFF_ACCESS(p,f) (eaccess((p), (f), ACC_SELF))
 #   else
         /* SCO */
-#       define PERL_EFF_ACCESS_R_OK(p) (eaccess((p), R_OK))
-#       define PERL_EFF_ACCESS_W_OK(p) (eaccess((p), W_OK))
-#       define PERL_EFF_ACCESS_X_OK(p) (eaccess((p), X_OK))
+#       define PERL_EFF_ACCESS(p,f) (eaccess((p), (f)))
 #   endif
 #endif
 
-#if !defined(PERL_EFF_ACCESS_R_OK) && defined(HAS_ACCESSX) && defined(ACC_SELF)
+#if !defined(PERL_EFF_ACCESS) && defined(HAS_ACCESSX) && defined(ACC_SELF)
     /* AIX */
-#   define PERL_EFF_ACCESS_R_OK(p) (accessx((p), R_OK, ACC_SELF))
-#   define PERL_EFF_ACCESS_W_OK(p) (accessx((p), W_OK, ACC_SELF))
-#   define PERL_EFF_ACCESS_X_OK(p) (accessx((p), X_OK, ACC_SELF))
+#   define PERL_EFF_ACCESS(p,f) (accessx((p), (f), ACC_SELF))
 #endif
 
-#if !defined(PERL_EFF_ACCESS_R_OK) && defined(HAS_ACCESS)	\
+
+#if !defined(PERL_EFF_ACCESS) && defined(HAS_ACCESS)	\
     && (defined(HAS_SETREUID) || defined(HAS_SETRESUID)		\
 	|| defined(HAS_SETREGID) || defined(HAS_SETRESGID))
 /* The Hard Way. */
@@ -306,12 +297,10 @@ S_emulate_eaccess(pTHX_ const char* path, Mode_t mode)
 
     return res;
 }
-#   define PERL_EFF_ACCESS_R_OK(p) (emulate_eaccess((p), R_OK))
-#   define PERL_EFF_ACCESS_W_OK(p) (emulate_eaccess((p), W_OK))
-#   define PERL_EFF_ACCESS_X_OK(p) (emulate_eaccess((p), X_OK))
+#   define PERL_EFF_ACCESS(p,f) (emulate_eaccess((p), (f)))
 #endif
 
-#if !defined(PERL_EFF_ACCESS_R_OK)
+#if !defined(PERL_EFF_ACCESS)
 /* With it or without it: anyway you get a warning: either that
    it is unused, or it is declared static and never defined.
  */
@@ -341,10 +330,7 @@ PP(pp_backtick)
 	mode = "rt";
     fp = PerlProc_popen(tmps, mode);
     if (fp) {
-        const char *type = NULL;
-	if (PL_curcop->cop_io) {
-	    type = SvPV_nolen_const(PL_curcop->cop_io);
-	}
+        const char * const type = PL_curcop->cop_io ? SvPV_nolen_const(PL_curcop->cop_io) : NULL;
 	if (type && *type)
 	    PerlIO_apply_layers(aTHX_ fp,mode,type);
 
@@ -441,12 +427,16 @@ PP(pp_warn)
     SV *tmpsv;
     const char *tmps;
     STRLEN len;
-    if (SP - MARK != 1) {
+    if (SP - MARK > 1) {
 	dTARGET;
 	do_join(TARG, &PL_sv_no, MARK, SP);
 	tmpsv = TARG;
 	SP = MARK + 1;
     }
+    else if (SP == MARK) {
+	tmpsv = &PL_sv_no;
+	EXTEND(SP, 1);
+    }
     else {
 	tmpsv = TOPs;
     }
@@ -489,17 +479,17 @@ PP(pp_die)
         tmps = SvROK(tmpsv) ? Nullch : SvPV_const(tmpsv, len);
     }
     if (!tmps || !len) {
-  	SV *error = ERRSV;
+	SV * const error = ERRSV;
 	SvUPGRADE(error, SVt_PV);
 	if (multiarg ? SvROK(error) : SvROK(tmpsv)) {
 	    if (!multiarg)
 		SvSetSV(error,tmpsv);
 	    else if (sv_isobject(error)) {
-		HV *stash = SvSTASH(SvRV(error));
-		GV *gv = gv_fetchmethod(stash, "PROPAGATE");
+		HV * const stash = SvSTASH(SvRV(error));
+		GV * const gv = gv_fetchmethod(stash, "PROPAGATE");
 		if (gv) {
-		    SV *file = sv_2mortal(newSVpv(CopFILE(PL_curcop),0));
-		    SV *line = sv_2mortal(newSVuv(CopLINE(PL_curcop)));
+		    SV * const file = sv_2mortal(newSVpv(CopFILE(PL_curcop),0));
+		    SV * const line = sv_2mortal(newSVuv(CopLINE(PL_curcop)));
 		    EXTEND(SP, 3);
 		    PUSHMARK(SP);
 		    PUSHs(error);
@@ -887,9 +877,9 @@ PP(pp_untie)
 
     if ((mg = SvTIED_mg(sv, how))) {
 	SV * const obj = SvRV(SvTIED_obj(sv, mg));
-	CV *cv = NULL;
         if (obj) {
 	    GV * const gv = gv_fetchmethod_autoload(SvSTASH(obj), "UNTIE", FALSE);
+	    CV *cv;
 	    if (gv && isGV(gv) && (cv = GvCV(gv))) {
 	       PUSHMARK(SP);
 	       XPUSHs(SvTIED_obj((SV*)gv, mg));
@@ -1165,12 +1155,10 @@ Perl_setdefout(pTHX_ GV *gv)
 PP(pp_select)
 {
     dSP; dTARGET;
-    GV *egv;
     HV *hv;
-
     GV * const newdefout = (PL_op->op_private > 0) ? ((GV *) POPs) : (GV *) NULL;
+    GV * egv = GvEGV(PL_defoutgv);
 
-    egv = GvEGV(PL_defoutgv);
     if (!egv)
 	egv = PL_defoutgv;
     hv = GvSTASH(egv);
@@ -1334,14 +1322,14 @@ PP(pp_leavewrite)
 		if (!IoFMT_NAME(io))
 		    IoFMT_NAME(io) = savepv(GvNAME(gv));
 		topname = sv_2mortal(Perl_newSVpvf(aTHX_ "%s_TOP", GvNAME(gv)));
-		topgv = gv_fetchsv(topname, FALSE, SVt_PVFM);
+		topgv = gv_fetchsv(topname, 0, SVt_PVFM);
 		if ((topgv && GvFORM(topgv)) ||
-		  !gv_fetchpv("top",FALSE,SVt_PVFM))
+		  !gv_fetchpv("top", 0, SVt_PVFM))
 		    IoTOP_NAME(io) = savesvpv(topname);
 		else
 		    IoTOP_NAME(io) = savepvn("top", 3);
 	    }
-	    topgv = gv_fetchpv(IoTOP_NAME(io),FALSE, SVt_PVFM);
+	    topgv = gv_fetchpv(IoTOP_NAME(io), 0, SVt_PVFM);
 	    if (!topgv || !GvFORM(topgv)) {
 		IoLINES_LEFT(io) = IoPAGE_LEN(io);
 		goto forget_top;
@@ -1779,41 +1767,34 @@ PP(pp_sysread)
     RETPUSHUNDEF;
 }
 
-PP(pp_syswrite)
-{
-    dVAR; dSP;
-    const int items = (SP - PL_stack_base) - TOPMARK;
-    if (items == 2) {
-	SV *sv;
-        EXTEND(SP, 1);
-	sv = sv_2mortal(newSViv(sv_len(*SP)));
-	PUSHs(sv);
-        PUTBACK;
-    }
-    return pp_send();
-}
-
 PP(pp_send)
 {
     dVAR; dSP; dMARK; dORIGMARK; dTARGET;
-    GV *gv;
     IO *io;
     SV *bufsv;
     const char *buffer;
-    Size_t length;
+    Size_t length = 0;
     SSize_t retval;
     STRLEN blen;
     MAGIC *mg;
-
-    gv = (GV*)*++MARK;
+    const int op_type = PL_op->op_type;
+    
+    GV *const gv = (GV*)*++MARK;
     if (PL_op->op_type == OP_SYSWRITE
 	&& gv && (io = GvIO(gv))
 	&& (mg = SvTIED_mg((SV*)io, PERL_MAGIC_tiedscalar)))
     {
 	SV *sv;
+
+	if (MARK == SP - 1) {
+	    EXTEND(SP, 1000);
+	    sv = sv_2mortal(newSViv(sv_len(*SP)));
+	    PUSHs(sv);
+	    PUTBACK;
+	}
 	
-	PUSHMARK(MARK-1);
-	*MARK = SvTIED_obj((SV*)io, mg);
+	PUSHMARK(ORIGMARK);
+	*(ORIGMARK+1) = SvTIED_obj((SV*)io, mg);
 	ENTER;
 	call_method("WRITE", G_SCALAR);
 	LEAVE;
@@ -1825,14 +1806,22 @@ PP(pp_send)
     }
     if (!gv)
 	goto say_undef;
+
     bufsv = *++MARK;
+
+    if (op_type == OP_SYSWRITE) {
+	if (MARK >= SP) {
+	    length = (Size_t) sv_len(bufsv);
+	} else {
 #if Size_t_size > IVSIZE
-    length = (Size_t)SvNVx(*++MARK);
+	    length = (Size_t)SvNVx(*++MARK);
 #else
-    length = (Size_t)SvIVx(*++MARK);
+	    length = (Size_t)SvIVx(*++MARK);
 #endif
-    if ((SSize_t)length < 0)
-	DIE(aTHX_ "Negative length");
+	    if ((SSize_t)length < 0)
+		DIE(aTHX_ "Negative length");
+	}
+    }
     SETERRNO(0,0);
     io = GvIO(gv);
     if (!io || !IoIFP(io)) {
@@ -1859,7 +1848,7 @@ PP(pp_send)
 	 buffer = SvPV_const(bufsv, blen);
     }
 
-    if (PL_op->op_type == OP_SYSWRITE) {
+    if (op_type == OP_SYSWRITE) {
 	IV offset;
 	if (DO_UTF8(bufsv)) {
 	    /* length and offset are in chars */
@@ -1898,16 +1887,19 @@ PP(pp_send)
 	}
     }
 #ifdef HAS_SOCKET
-    else if (SP > MARK) {
-	STRLEN mlen;
-	char * const sockbuf = SvPVx(*++MARK, mlen);
-	/* length is really flags */
-	retval = PerlSock_sendto(PerlIO_fileno(IoIFP(io)), buffer, blen,
-				 length, (struct sockaddr *)sockbuf, mlen);
+    else {
+	const int flags = SvIVx(*++MARK);
+	if (SP > MARK) {
+	    STRLEN mlen;
+	    char * const sockbuf = SvPVx(*++MARK, mlen);
+	    retval = PerlSock_sendto(PerlIO_fileno(IoIFP(io)), buffer, blen,
+				     flags, (struct sockaddr *)sockbuf, mlen);
+	}
+	else {
+	    retval
+		= PerlSock_send(PerlIO_fileno(IoIFP(io)), buffer, blen, flags);
+	}
     }
-    else
-	/* length is really flags */
-	retval = PerlSock_send(PerlIO_fileno(IoIFP(io)), buffer, blen, length);
 #else
     else
 	DIE(aTHX_ PL_no_sock_func, "send");
@@ -2011,17 +2003,16 @@ PP(pp_tell)
 PP(pp_sysseek)
 {
     dVAR; dSP;
-    GV *gv;
     IO *io;
     const int whence = POPi;
 #if LSEEKSIZE > IVSIZE
-    Off_t offset = (Off_t)SvNVx(POPs);
+    const Off_t offset = (Off_t)SvNVx(POPs);
 #else
-    Off_t offset = (Off_t)SvIVx(POPs);
+    const Off_t offset = (Off_t)SvIVx(POPs);
 #endif
     MAGIC *mg;
 
-    gv = PL_last_in_gv = (GV*)POPs;
+    GV * const gv = PL_last_in_gv = (GV*)POPs;
 
     if (gv && (io = GvIO(gv))
 	&& (mg = SvTIED_mg((SV*)io, PERL_MAGIC_tiedscalar)))
@@ -2045,11 +2036,11 @@ PP(pp_sysseek)
     if (PL_op->op_type == OP_SEEK)
 	PUSHs(boolSV(do_seek(gv, offset, whence)));
     else {
-	Off_t sought = do_sysseek(gv, offset, whence);
+	const Off_t sought = do_sysseek(gv, offset, whence);
         if (sought < 0)
             PUSHs(&PL_sv_undef);
         else {
-            SV* sv = sought ?
+            SV* const sv = sought ?
 #if LSEEKSIZE > IVSIZE
                 newSVnv((NV)sought)
 #else
@@ -2087,7 +2078,7 @@ PP(pp_truncate)
 	IO *io;
 
 	if (PL_op->op_flags & OPf_SPECIAL) {
-	    tmpgv = gv_fetchsv(POPs, FALSE, SVt_PVIO);
+	    tmpgv = gv_fetchsv(POPs, 0, SVt_PVIO);
 
 	do_ftruncate_gv:
 	    if (!GvIO(tmpgv))
@@ -2112,7 +2103,7 @@ PP(pp_truncate)
 	    }
 	}
 	else {
-	    SV *sv = POPs;
+	    SV * const sv = POPs;
 	    const char *name;
 
 	    if (SvTYPE(sv) == SVt_PVGV) {
@@ -2135,9 +2126,9 @@ PP(pp_truncate)
 	        result = 0;
 #else
 	    {
-	        int tmpfd;
+		const int tmpfd = PerlLIO_open(name, O_RDWR);
 
-		if ((tmpfd = PerlLIO_open(name, O_RDWR)) < 0)
+		if (tmpfd < 0)
 		    result = 0;
 		else {
 		    if (my_chsize(tmpfd, len) < 0)
@@ -2159,13 +2150,13 @@ PP(pp_truncate)
 PP(pp_ioctl)
 {
     dSP; dTARGET;
-    SV *argsv = POPs;
+    SV * const argsv = POPs;
     const unsigned int func = POPu;
     const int optype = PL_op->op_type;
+    GV * const gv = (GV*)POPs;
+    IO * const io = gv ? GvIOn(gv) : Null(IO*);
     char *s;
     IV retval;
-    GV *gv = (GV*)POPs;
-    IO *io = gv ? GvIOn(gv) : 0;
 
     if (!io || !argsv || !IoIFP(io)) {
 	if (ckWARN2(WARN_UNOPENED,WARN_CLOSED))
@@ -2191,7 +2182,7 @@ PP(pp_ioctl)
 	s = INT2PTR(char*,retval);		/* ouch */
     }
 
-    TAINT_PROPER(optype == OP_IOCTL ? "ioctl" : "fcntl");
+    TAINT_PROPER(PL_op_desc[optype]);
 
     if (optype == OP_IOCTL)
 #ifdef HAS_IOCTL
@@ -2236,22 +2227,18 @@ PP(pp_flock)
 #ifdef FLOCK
     dSP; dTARGET;
     I32 value;
-    int argtype;
-    GV *gv;
     IO *io = NULL;
     PerlIO *fp;
+    const int argtype = POPi;
+    GV * const gv = (MAXARG == 0) ? PL_last_in_gv : (GV*)POPs;
 
-    argtype = POPi;
-    if (MAXARG == 0)
-	gv = PL_last_in_gv;
-    else
-	gv = (GV*)POPs;
     if (gv && (io = GvIO(gv)))
 	fp = IoIFP(io);
     else {
 	fp = Nullfp;
 	io = NULL;
     }
+    /* XXX Looks to me like io is always NULL at this point */
     if (fp) {
 	(void)PerlIO_flush(fp);
 	value = (I32)(PerlLIO_flock(PerlIO_fileno(fp), argtype) >= 0);
@@ -2275,16 +2262,13 @@ PP(pp_socket)
 {
 #ifdef HAS_SOCKET
     dSP;
-    GV *gv;
-    register IO *io;
-    int protocol = POPi;
-    int type = POPi;
-    int domain = POPi;
+    const int protocol = POPi;
+    const int type = POPi;
+    const int domain = POPi;
+    GV * const gv = (GV*)POPs;
+    register IO * const io = gv ? GvIOn(gv) : NULL;
     int fd;
 
-    gv = (GV*)POPs;
-    io = gv ? GvIOn(gv) : NULL;
-
     if (!gv || !io) {
 	if (ckWARN2(WARN_UNOPENED,WARN_CLOSED))
 	    report_evil_fh(gv, io, PL_op->op_type);
@@ -2328,19 +2312,15 @@ PP(pp_sockpair)
 {
 #if defined (HAS_SOCKETPAIR) || (defined (HAS_SOCKET) && defined(SOCK_DGRAM) && defined(AF_INET) && defined(PF_INET))
     dSP;
-    GV *gv1;
-    GV *gv2;
-    register IO *io1;
-    register IO *io2;
-    int protocol = POPi;
-    int type = POPi;
-    int domain = POPi;
+    const int protocol = POPi;
+    const int type = POPi;
+    const int domain = POPi;
+    GV * const gv2 = (GV*)POPs;
+    GV * const gv1 = (GV*)POPs;
+    register IO * const io1 = gv1 ? GvIOn(gv1) : NULL;
+    register IO * const io2 = gv2 ? GvIOn(gv2) : NULL;
     int fd[2];
 
-    gv2 = (GV*)POPs;
-    gv1 = (GV*)POPs;
-    io1 = gv1 ? GvIOn(gv1) : NULL;
-    io2 = gv2 ? GvIOn(gv2) : NULL;
     if (!gv1 || !gv2 || !io1 || !io2) {
 	if (ckWARN2(WARN_UNOPENED,WARN_CLOSED)) {
 	    if (!gv1 || !io1)
@@ -2397,11 +2377,11 @@ PP(pp_bind)
     extern void GETPRIVMODE();
     extern void GETUSERMODE();
 #endif
-    SV *addrsv = POPs;
+    SV * const addrsv = POPs;
     /* OK, so on what platform does bind modify addr?  */
     const char *addr;
-    GV *gv = (GV*)POPs;
-    register IO *io = GvIOn(gv);
+    GV * const gv = (GV*)POPs;
+    register IO * const io = GvIOn(gv);
     STRLEN len;
     int bind_ok = 0;
 #ifdef MPE
@@ -2453,10 +2433,10 @@ PP(pp_connect)
 {
 #ifdef HAS_SOCKET
     dSP;
-    SV *addrsv = POPs;
+    SV * const addrsv = POPs;
+    GV * const gv = (GV*)POPs;
+    register IO * const io = GvIOn(gv);
     const char *addr;
-    GV *gv = (GV*)POPs;
-    register IO *io = GvIOn(gv);
     STRLEN len;
 
     if (!io || !IoIFP(io))
@@ -2483,9 +2463,9 @@ PP(pp_listen)
 {
 #ifdef HAS_SOCKET
     dSP;
-    int backlog = POPi;
-    GV *gv = (GV*)POPs;
-    register IO *io = gv ? GvIOn(gv) : NULL;
+    const int backlog = POPi;
+    GV * const gv = (GV*)POPs;
+    register IO * const io = gv ? GvIOn(gv) : NULL;
 
     if (!gv || !io || !IoIFP(io))
 	goto nuts;
@@ -2509,8 +2489,6 @@ PP(pp_accept)
 {
 #ifdef HAS_SOCKET
     dSP; dTARGET;
-    GV *ngv;
-    GV *ggv;
     register IO *nstio;
     register IO *gstio;
     char namebuf[MAXPATHLEN];
@@ -2519,11 +2497,10 @@ PP(pp_accept)
 #else
     Sock_size_t len = sizeof namebuf;
 #endif
+    GV * const ggv = (GV*)POPs;
+    GV * const ngv = (GV*)POPs;
     int fd;
 
-    ggv = (GV*)POPs;
-    ngv = (GV*)POPs;
-
     if (!ngv)
 	goto badexit;
     if (!ggv)
@@ -2580,9 +2557,9 @@ PP(pp_shutdown)
 {
 #ifdef HAS_SOCKET
     dSP; dTARGET;
-    int how = POPi;
-    GV *gv = (GV*)POPs;
-    register IO *io = GvIOn(gv);
+    const int how = POPi;
+    GV * const gv = (GV*)POPs;
+    register IO * const io = GvIOn(gv);
 
     if (!io || !IoIFP(io))
 	goto nuts;
@@ -2604,24 +2581,15 @@ PP(pp_ssockopt)
 {
 #ifdef HAS_SOCKET
     dSP;
-    int optype = PL_op->op_type;
-    SV *sv;
+    const int optype = PL_op->op_type;
+    SV * const sv = (optype == OP_GSOCKOPT) ? sv_2mortal(NEWSV(22, 257)) : POPs;
+    const unsigned int optname = (unsigned int) POPi;
+    const unsigned int lvl = (unsigned int) POPi;
+    GV * const gv = (GV*)POPs;
+    register IO * const io = GvIOn(gv);
     int fd;
-    unsigned int optname;
-    unsigned int lvl;
-    GV *gv;
-    register IO *io;
     Sock_size_t len;
 
-    if (optype == OP_GSOCKOPT)
-	sv = sv_2mortal(NEWSV(22, 257));
-    else
-	sv = POPs;
-    optname = (unsigned int) POPi;
-    lvl = (unsigned int) POPi;
-
-    gv = (GV*)POPs;
-    io = GvIOn(gv);
     if (!io || !IoIFP(io))
 	goto nuts;
 
@@ -2690,12 +2658,12 @@ PP(pp_getpeername)
 {
 #ifdef HAS_SOCKET
     dSP;
-    int optype = PL_op->op_type;
+    const int optype = PL_op->op_type;
+    GV * const gv = (GV*)POPs;
+    register IO * const io = GvIOn(gv);
+    Sock_size_t len;
     SV *sv;
     int fd;
-    GV *gv = (GV*)POPs;
-    register IO *io = GvIOn(gv);
-    Sock_size_t len;
 
     if (!io || !IoIFP(io))
 	goto nuts;
@@ -2786,7 +2754,7 @@ PP(pp_stat)
 	}
     }
     else {
-	SV* sv = POPs;
+	SV* const sv = POPs;
 	if (SvTYPE(sv) == SVt_PVGV) {
 	    gv = (GV*)sv;
 	    goto do_fstat;
@@ -2884,161 +2852,110 @@ PP(pp_stat)
 PP(pp_ftrread)
 {
     I32 result;
-    dSP;
-    STACKED_FTEST_CHECK;
-#if defined(HAS_ACCESS) && defined(R_OK)
-    if ((PL_op->op_private & OPpFT_ACCESS) && SvPOK(TOPs)) {
-	result = access(POPpx, R_OK);
-	if (result == 0)
-	    RETPUSHYES;
-	if (result < 0)
-	    RETPUSHUNDEF;
-	RETPUSHNO;
-    }
-    else
-	result = my_stat();
+    /* Not const, because things tweak this below. Not bool, because there's
+       no guarantee that OPp_FT_ACCESS is <= CHAR_MAX  */
+#if defined(HAS_ACCESS) || defined (PERL_EFF_ACCESS)
+    I32 use_access = PL_op->op_private & OPpFT_ACCESS;
+    /* Giving some sort of initial value silences compilers.  */
+#  ifdef R_OK
+    int access_mode = R_OK;
+#  else
+    int access_mode = 0;
+#  endif
 #else
-    result = my_stat();
+    /* access_mode is never used, but leaving use_access in makes the
+       conditional compiling below much clearer.  */
+    I32 use_access = 0;
 #endif
-    SPAGAIN;
-    if (result < 0)
-	RETPUSHUNDEF;
-    if (cando(S_IRUSR, 0, &PL_statcache))
-	RETPUSHYES;
-    RETPUSHNO;
-}
+    int stat_mode = S_IRUSR;
 
-PP(pp_ftrwrite)
-{
-    I32 result;
+    bool effective = FALSE;
     dSP;
+
     STACKED_FTEST_CHECK;
+
+    switch (PL_op->op_type) {
+    case OP_FTRREAD:
+#if !(defined(HAS_ACCESS) && defined(R_OK))
+	use_access = 0;
+#endif
+	break;
+
+    case OP_FTRWRITE:
 #if defined(HAS_ACCESS) && defined(W_OK)
-    if ((PL_op->op_private & OPpFT_ACCESS) && SvPOK(TOPs)) {
-	result = access(POPpx, W_OK);
-	if (result == 0)
-	    RETPUSHYES;
-	if (result < 0)
-	    RETPUSHUNDEF;
-	RETPUSHNO;
-    }
-    else
-	result = my_stat();
+	access_mode = W_OK;
 #else
-    result = my_stat();
+	use_access = 0;
 #endif
-    SPAGAIN;
-    if (result < 0)
-	RETPUSHUNDEF;
-    if (cando(S_IWUSR, 0, &PL_statcache))
-	RETPUSHYES;
-    RETPUSHNO;
-}
+	stat_mode = S_IWUSR;
+	break;
 
-PP(pp_ftrexec)
-{
-    I32 result;
-    dSP;
-    STACKED_FTEST_CHECK;
+    case OP_FTREXEC:
 #if defined(HAS_ACCESS) && defined(X_OK)
-    if ((PL_op->op_private & OPpFT_ACCESS) && SvPOK(TOPs)) {
-	result = access(POPpx, X_OK);
-	if (result == 0)
-	    RETPUSHYES;
-	if (result < 0)
-	    RETPUSHUNDEF;
-	RETPUSHNO;
-    }
-    else
-	result = my_stat();
+	access_mode = X_OK;
 #else
-    result = my_stat();
+	use_access = 0;
 #endif
-    SPAGAIN;
-    if (result < 0)
-	RETPUSHUNDEF;
-    if (cando(S_IXUSR, 0, &PL_statcache))
-	RETPUSHYES;
-    RETPUSHNO;
-}
+	stat_mode = S_IXUSR;
+	break;
 
-PP(pp_fteread)
-{
-    I32 result;
-    dSP;
-    STACKED_FTEST_CHECK;
-#ifdef PERL_EFF_ACCESS_R_OK
-    if ((PL_op->op_private & OPpFT_ACCESS) && SvPOK(TOPs)) {
-	result = PERL_EFF_ACCESS_R_OK(POPpx);
-	if (result == 0)
-	    RETPUSHYES;
-	if (result < 0)
-	    RETPUSHUNDEF;
-	RETPUSHNO;
-    }
-    else
-	result = my_stat();
-#else
-    result = my_stat();
+    case OP_FTEWRITE:
+#ifdef PERL_EFF_ACCESS
+	access_mode = W_OK;
 #endif
-    SPAGAIN;
-    if (result < 0)
-	RETPUSHUNDEF;
-    if (cando(S_IRUSR, 1, &PL_statcache))
-	RETPUSHYES;
-    RETPUSHNO;
-}
+	stat_mode = S_IWUSR;
+	/* Fall through  */
 
-PP(pp_ftewrite)
-{
-    I32 result;
-    dSP;
-    STACKED_FTEST_CHECK;
-#ifdef PERL_EFF_ACCESS_W_OK
-    if ((PL_op->op_private & OPpFT_ACCESS) && SvPOK(TOPs)) {
-	result = PERL_EFF_ACCESS_W_OK(POPpx);
-	if (result == 0)
-	    RETPUSHYES;
-	if (result < 0)
-	    RETPUSHUNDEF;
-	RETPUSHNO;
-    }
-    else
-	result = my_stat();
+    case OP_FTEREAD:
+#ifndef PERL_EFF_ACCESS
+	use_access = 0;
+#endif
+	effective = TRUE;
+	break;
+
+
+    case OP_FTEEXEC:
+#ifdef PERL_EFF_ACCESS
+	access_mode = W_OK;
 #else
-    result = my_stat();
+	use_access = 0;
 #endif
-    SPAGAIN;
-    if (result < 0)
-	RETPUSHUNDEF;
-    if (cando(S_IWUSR, 1, &PL_statcache))
-	RETPUSHYES;
-    RETPUSHNO;
-}
+	stat_mode = S_IXUSR;
+	effective = TRUE;
+	break;
+    }
 
-PP(pp_fteexec)
-{
-    I32 result;
-    dSP;
-    STACKED_FTEST_CHECK;
-#ifdef PERL_EFF_ACCESS_X_OK
-    if ((PL_op->op_private & OPpFT_ACCESS) && SvPOK(TOPs)) {
-	result = PERL_EFF_ACCESS_X_OK(POPpx);
+    if (use_access) {
+#if defined(HAS_ACCESS) || defined (PERL_EFF_ACCESS)
+	const char *const name = POPpx;
+	if (effective) {
+#  ifdef PERL_EFF_ACCESS
+	    result = PERL_EFF_ACCESS(name, access_mode);
+#  else
+	    DIE(aTHX_ "panic: attempt to call PERL_EFF_ACCESS in %s",
+		OP_NAME(PL_op));
+#  endif
+	}
+	else {
+#  ifdef HAS_ACCESS
+	    result = access(name, access_mode);
+#  else
+	    DIE(aTHX_ "panic: attempt to call access() in %s", OP_NAME(PL_op));
+#  endif
+	}
 	if (result == 0)
 	    RETPUSHYES;
 	if (result < 0)
 	    RETPUSHUNDEF;
 	RETPUSHNO;
+#endif
     }
-    else
-	result = my_stat();
-#else
+
     result = my_stat();
-#endif
     SPAGAIN;
     if (result < 0)
 	RETPUSHUNDEF;
-    if (cando(S_IXUSR, 1, &PL_statcache))
+    if (cando(stat_mode, effective, &PL_statcache))
 	RETPUSHYES;
     RETPUSHNO;
 }
@@ -3108,7 +3025,7 @@ PP(pp_ftrowned)
 	RETPUSHUNDEF;
     switch (PL_op->op_type) {
     case OP_FTROWNED:
-	if (PL_statcache.st_uid == PL_uid);
+	if (PL_statcache.st_uid == PL_uid)
 	    RETPUSHYES;
 	break;
     case OP_FTEOWNED:
@@ -3192,7 +3109,7 @@ PP(pp_fttty)
     else if (SvROK(TOPs) && isGV(SvRV(TOPs)))
 	gv = (GV*)SvRV(POPs);
     else
-	gv = gv_fetchsv(tmpsv = POPs, FALSE, SVt_PVIO);
+	gv = gv_fetchsv(tmpsv = POPs, 0, SVt_PVIO);
 
     if (GvIO(gv) && IoIFP(GvIOp(gv)))
 	fd = PerlIO_fileno(IoIFP(GvIOp(gv)));
@@ -3379,7 +3296,7 @@ PP(pp_fttext)
 PP(pp_chdir)
 {
     dSP; dTARGET;
-    const char *tmps = 0;
+    const char *tmps = NULL;
     GV *gv = NULL;
 
     if( MAXARG == 1 ) {
@@ -3459,7 +3376,7 @@ PP(pp_chown)
     const I32 value = (I32)apply(PL_op->op_type, MARK, SP);
 
     SP = MARK;
-    PUSHi(value);
+    XPUSHi(value);
     RETURN;
 }
 
@@ -3467,7 +3384,7 @@ PP(pp_chroot)
 {
 #ifdef HAS_CHROOT
     dSP; dTARGET;
-    char *tmps = POPpx;
+    char * const tmps = POPpx;
     TAINT_PROPER("chroot");
     PUSHi( chroot(tmps) >= 0 );
     RETURN;
@@ -3480,8 +3397,8 @@ PP(pp_rename)
 {
     dSP; dTARGET;
     int anum;
-    const char *tmps2 = POPpconstx;
-    const char *tmps = SvPV_nolen_const(TOPs);
+    const char * const tmps2 = POPpconstx;
+    const char * const tmps = SvPV_nolen_const(TOPs);
     TAINT_PROPER("rename");
 #ifdef HAS_RENAME
     anum = PerlLIO_rename(tmps, tmps2);
@@ -3518,8 +3435,8 @@ PP(pp_link)
 #  endif
 
     {
-	const char *tmps2 = POPpconstx;
-	const char *tmps = SvPV_nolen_const(TOPs);
+	const char * const tmps2 = POPpconstx;
+	const char * const tmps = SvPV_nolen_const(TOPs);
 	TAINT_PROPER(PL_op_desc[op_type]);
 	result =
 #  if defined(HAS_LINK)
@@ -3528,13 +3445,13 @@ PP(pp_link)
 	    (op_type == OP_LINK) ?
 	    PerlLIO_link(tmps, tmps2) : symlink(tmps, tmps2);
 #    else
-    /* Only have symlink, so calls to pp_link will have DIE()d above.  */
-	symlink(tmps, tmps2);
+    /* Only have link, so calls to pp_symlink will have DIE()d above.  */
+	PerlLIO_link(tmps, tmps2);
 #    endif
 #  else
 #    if defined(HAS_SYMLINK)
-    /* Only have link, so calls to pp_symlink will have DIE()d above.  */
-	PerlLIO_link(tmps, tmps2);
+    /* Only have symlink, so calls to pp_link will have DIE()d above.  */
+	symlink(tmps, tmps2);
 #    endif
 #  endif
     }
@@ -3597,7 +3514,7 @@ S_dooneliner(pTHX_ const char *cmd, const char *filename)
     Safefree(cmdline);
 
     if (myfp) {
-	SV *tmpsv = sv_newmortal();
+	SV * const tmpsv = sv_newmortal();
 	/* Need to save/restore 'PL_rs' ?? */
 	s = sv_gets(tmpsv, myfp, 0);
 	(void)PerlProc_pclose(myfp);
@@ -3685,18 +3602,10 @@ S_dooneliner(pTHX_ const char *cmd, const char *filename)
 PP(pp_mkdir)
 {
     dSP; dTARGET;
-    int mode;
-#ifndef HAS_MKDIR
-    int oldumask;
-#endif
     STRLEN len;
     const char *tmps;
     bool copy = FALSE;
-
-    if (MAXARG > 1)
-	mode = POPi;
-    else
-	mode = 0777;
+    const int mode = (MAXARG > 1) ? POPi : 0777;
 
     TRIMSLASHES(tmps,len,copy);
 
@@ -3704,10 +3613,13 @@ PP(pp_mkdir)
 #ifdef HAS_MKDIR
     SETi( PerlDir_mkdir(tmps, mode) >= 0 );
 #else
+    {
+    int oldumask;
     SETi( dooneliner("mkdir", tmps) );
     oldumask = PerlLIO_umask(0);
     PerlLIO_umask(oldumask);
     PerlLIO_chmod(tmps, (mode & ~oldumask) & 0777);
+    }
 #endif
     if (copy)
 	Safefree(tmps);
@@ -3739,9 +3651,9 @@ PP(pp_open_dir)
 {
 #if defined(Direntry_t) && defined(HAS_READDIR)
     dSP;
-    const char *dirname = POPpconstx;
-    GV *gv = (GV*)POPs;
-    register IO *io = GvIOn(gv);
+    const char * const dirname = POPpconstx;
+    GV * const gv = (GV*)POPs;
+    register IO * const io = GvIOn(gv);
 
     if (!io)
 	goto nope;
@@ -3773,9 +3685,9 @@ PP(pp_readdir)
 
     SV *sv;
     const I32 gimme = GIMME;
-    GV *gv = (GV *)POPs;
-    register Direntry_t *dp;
-    register IO *io = GvIOn(gv);
+    GV * const gv = (GV *)POPs;
+    register const Direntry_t *dp;
+    register IO * const io = GvIOn(gv);
 
     if (!io || !IoDIRP(io))
 	goto nope;
@@ -3823,8 +3735,8 @@ PP(pp_telldir)
 # if !defined(HAS_TELLDIR_PROTO) || defined(NEED_TELLDIR_PROTO)
     long telldir (DIR *);
 # endif
-    GV *gv = (GV*)POPs;
-    register IO *io = GvIOn(gv);
+    GV * const gv = (GV*)POPs;
+    register IO * const io = GvIOn(gv);
 
     if (!io || !IoDIRP(io))
 	goto nope;
@@ -3844,9 +3756,9 @@ PP(pp_seekdir)
 {
 #if defined(HAS_SEEKDIR) || defined(seekdir)
     dSP;
-    long along = POPl;
-    GV *gv = (GV*)POPs;
-    register IO *io = GvIOn(gv);
+    const long along = POPl;
+    GV * const gv = (GV*)POPs;
+    register IO * const io = GvIOn(gv);
 
     if (!io || !IoDIRP(io))
 	goto nope;
@@ -3867,8 +3779,8 @@ PP(pp_rewinddir)
 {
 #if defined(HAS_REWINDDIR) || defined(rewinddir)
     dSP;
-    GV *gv = (GV*)POPs;
-    register IO *io = GvIOn(gv);
+    GV * const gv = (GV*)POPs;
+    register IO * const io = GvIOn(gv);
 
     if (!io || !IoDIRP(io))
 	goto nope;
@@ -3888,8 +3800,8 @@ PP(pp_closedir)
 {
 #if defined(Direntry_t) && defined(HAS_READDIR)
     dSP;
-    GV *gv = (GV*)POPs;
-    register IO *io = GvIOn(gv);
+    GV * const gv = (GV*)POPs;
+    register IO * const io = GvIOn(gv);
 
     if (!io || !IoDIRP(io))
 	goto nope;
@@ -3921,7 +3833,6 @@ PP(pp_fork)
 #ifdef HAS_FORK
     dSP; dTARGET;
     Pid_t childpid;
-    GV *tmpgv;
 
     EXTEND(SP, 1);
     PERL_FLUSHALL_FOR_CHILD;
@@ -3929,7 +3840,8 @@ PP(pp_fork)
     if (childpid < 0)
 	RETSETUNDEF;
     if (!childpid) {
-	if ((tmpgv = gv_fetchpv("$", TRUE, SVt_PV))) {
+	GV * const tmpgv = gv_fetchpv("$", GV_ADD, SVt_PV);
+	if (tmpgv) {
             SvREADONLY_off(GvSV(tmpgv));
 	    sv_setiv(GvSV(tmpgv), (IV)PerlProc_getpid());
             SvREADONLY_on(GvSV(tmpgv));
@@ -3993,13 +3905,11 @@ PP(pp_waitpid)
 {
 #if (!defined(DOSISH) || defined(OS2) || defined(WIN32)) && !defined(MACOS_TRADITIONAL)
     dSP; dTARGET;
-    Pid_t pid;
+    const int optype = POPi;
+    const Pid_t pid = TOPi;
     Pid_t result;
-    int optype;
     int argflags;
 
-    optype = POPi;
-    pid = TOPi;
     if (PL_signals & PERL_SIGNALS_UNSAFE_FLAG)
         result = wait4pid(pid, &argflags, optype);
     else {
@@ -4050,7 +3960,7 @@ PP(pp_system)
 	    if (errno != EAGAIN) {
 		value = -1;
 		SP = ORIGMARK;
-		PUSHi(value);
+		XPUSHi(value);
 		if (did_pipes) {
 		    PerlLIO_close(pp[0]);
 		    PerlLIO_close(pp[1]);
@@ -4099,7 +4009,7 @@ PP(pp_system)
 		    STATUS_NATIVE_CHILD_SET(-1);
 		}
 	    }
-	    PUSHi(STATUS_CURRENT);
+	    XPUSHi(STATUS_CURRENT);
 	    RETURN;
 	}
 	if (did_pipes) {
@@ -4109,7 +4019,7 @@ PP(pp_system)
 #endif
 	}
 	if (PL_op->op_flags & OPf_STACKED) {
-	    SV *really = *++MARK;
+	    SV * const really = *++MARK;
 	    value = (I32)do_aexec5(really, MARK, SP, pp[1], did_pipes);
 	}
 	else if (SP - MARK != 1)
@@ -4123,7 +4033,7 @@ PP(pp_system)
     PL_statusvalue = 0;
     result = 0;
     if (PL_op->op_flags & OPf_STACKED) {
-	SV *really = *++MARK;
+	SV * const really = *++MARK;
 #  if defined(WIN32) || defined(OS2) || defined(__SYMBIAN32__)
 	value = (I32)do_aspawn(really, MARK, SP);
 #  else
@@ -4145,7 +4055,7 @@ PP(pp_system)
     STATUS_NATIVE_CHILD_SET(value);
     do_execfree();
     SP = ORIGMARK;
-    PUSHi(result ? value : STATUS_CURRENT);
+    XPUSHi(result ? value : STATUS_CURRENT);
 #endif /* !FORK or VMS */
     RETURN;
 }
@@ -4167,7 +4077,7 @@ PP(pp_exec)
     }
     PERL_FLUSHALL_FOR_CHILD;
     if (PL_op->op_flags & OPf_STACKED) {
-	SV *really = *++MARK;
+	SV * const really = *++MARK;
 	value = (I32)do_aexec(really, MARK, SP);
     }
     else if (SP - MARK != 1)
@@ -4197,7 +4107,7 @@ PP(pp_exec)
     }
 
     SP = ORIGMARK;
-    PUSHi(value);
+    XPUSHi(value);
     RETURN;
 }
 
@@ -4223,13 +4133,9 @@ PP(pp_getpgrp)
 {
 #ifdef HAS_GETPGRP
     dSP; dTARGET;
-    Pid_t pid;
     Pid_t pgrp;
+    const Pid_t pid = (MAXARG < 1) ? 0 : SvIVx(POPs);
 
-    if (MAXARG < 1)
-	pid = 0;
-    else
-	pid = SvIVx(POPs);
 #ifdef BSD_GETPGRP
     pgrp = (I32)BSD_GETPGRP(pid);
 #else
@@ -4280,8 +4186,8 @@ PP(pp_getpriority)
 {
 #ifdef HAS_GETPRIORITY
     dSP; dTARGET;
-    int who = POPi;
-    int which = TOPi;
+    const int who = POPi;
+    const int which = TOPi;
     SETi( getpriority(which, who) );
     RETURN;
 #else
@@ -4293,9 +4199,9 @@ PP(pp_setpriority)
 {
 #ifdef HAS_SETPRIORITY
     dSP; dTARGET;
-    int niceval = POPi;
-    int who = POPi;
-    int which = TOPi;
+    const int niceval = POPi;
+    const int who = POPi;
+    const int which = TOPi;
     TAINT_PROPER("setpriority");
     SETi( setpriority(which, who, niceval) >= 0 );
     RETURN;
@@ -4492,40 +4398,30 @@ PP(pp_sleep)
 }
 
 /* Shared memory. */
+/* Merged with some message passing. */
 
 PP(pp_shmwrite)
 {
 #if defined(HAS_MSG) || defined(HAS_SEM) || defined(HAS_SHM)
     dSP; dMARK; dTARGET;
-    I32 value = (I32)(do_shmio(PL_op->op_type, MARK, SP) >= 0);
-    SP = MARK;
-    PUSHi(value);
-    RETURN;
-#else
-    return pp_semget();
-#endif
-}
-
-/* Message passing. */
+    const int op_type = PL_op->op_type;
+    I32 value;
 
-PP(pp_msgsnd)
-{
-#if defined(HAS_MSG) || defined(HAS_SEM) || defined(HAS_SHM)
-    dSP; dMARK; dTARGET;
-    I32 value = (I32)(do_msgsnd(MARK, SP) >= 0);
-    SP = MARK;
-    PUSHi(value);
-    RETURN;
-#else
-    return pp_semget();
-#endif
-}
+    switch (op_type) {
+    case OP_MSGSND:
+	value = (I32)(do_msgsnd(MARK, SP) >= 0);
+	break;
+    case OP_MSGRCV:
+	value = (I32)(do_msgrcv(MARK, SP) >= 0);
+	break;
+    case OP_SEMOP:
+	value = (I32)(do_semop(MARK, SP) >= 0);
+	break;
+    default:
+	value = (I32)(do_shmio(op_type, MARK, SP) >= 0);
+	break;
+    }
 
-PP(pp_msgrcv)
-{
-#if defined(HAS_MSG) || defined(HAS_SEM) || defined(HAS_SHM)
-    dSP; dMARK; dTARGET;
-    I32 value = (I32)(do_msgrcv(MARK, SP) >= 0);
     SP = MARK;
     PUSHi(value);
     RETURN;
@@ -4540,7 +4436,7 @@ PP(pp_semget)
 {
 #if defined(HAS_MSG) || defined(HAS_SEM) || defined(HAS_SHM)
     dSP; dMARK; dTARGET;
-    int anum = do_ipcget(PL_op->op_type, MARK, SP);
+    const int anum = do_ipcget(PL_op->op_type, MARK, SP);
     SP = MARK;
     if (anum == -1)
 	RETPUSHUNDEF;
@@ -4555,7 +4451,7 @@ PP(pp_semctl)
 {
 #if defined(HAS_MSG) || defined(HAS_SEM) || defined(HAS_SHM)
     dSP; dMARK; dTARGET;
-    int anum = do_ipcctl(PL_op->op_type, MARK, SP);
+    const int anum = do_ipcctl(PL_op->op_type, MARK, SP);
     SP = MARK;
     if (anum == -1)
 	RETSETUNDEF;
@@ -4571,19 +4467,6 @@ PP(pp_semctl)
 #endif
 }
 
-PP(pp_semop)
-{
-#if defined(HAS_MSG) || defined(HAS_SEM) || defined(HAS_SHM)
-    dSP; dMARK; dTARGET;
-    I32 value = (I32)(do_semop(MARK, SP) >= 0);
-    SP = MARK;
-    PUSHi(value);
-    RETURN;
-#else
-    return pp_semget();
-#endif
-}
-
 /* Get system info. */
 
 PP(pp_ghostent)
@@ -4604,7 +4487,7 @@ PP(pp_ghostent)
     EXTEND(SP, 10);
     if (which == OP_GHBYNAME) {
 #ifdef HAS_GETHOSTBYNAME
-        char* name = POPpbytex;
+	const char* const name = POPpbytex;
 	hent = PerlSock_gethostbyname(name);
 #else
 	DIE(aTHX_ PL_no_sock_func, "gethostbyname");
@@ -4612,8 +4495,8 @@ PP(pp_ghostent)
     }
     else if (which == OP_GHBYADDR) {
 #ifdef HAS_GETHOSTBYADDR
-	int addrtype = POPi;
-	SV *addrsv = POPs;
+	const int addrtype = POPi;
+	SV * const addrsv = POPs;
 	STRLEN addrlen;
 	Netdb_host_t addr = (Netdb_host_t) SvPVbyte(addrsv, addrlen);
 
@@ -4700,7 +4583,7 @@ PP(pp_gnetent)
 
     if (which == OP_GNBYNAME){
 #ifdef HAS_GETNETBYNAME
-        char *name = POPpbytex;
+	const char * const name = POPpbytex;
 	nent = PerlSock_getnetbyname(name);
 #else
         DIE(aTHX_ PL_no_sock_func, "getnetbyname");
@@ -4708,8 +4591,8 @@ PP(pp_gnetent)
     }
     else if (which == OP_GNBYADDR) {
 #ifdef HAS_GETNETBYADDR
-	int addrtype = POPi;
-	Netdb_net_t addr = (Netdb_net_t) (U32)POPu;
+	const int addrtype = POPi;
+	const Netdb_net_t addr = (Netdb_net_t) (U32)POPu;
 	nent = PerlSock_getnetbyaddr(addr, addrtype);
 #else
 	DIE(aTHX_ PL_no_sock_func, "getnetbyaddr");
@@ -4782,7 +4665,7 @@ PP(pp_gprotoent)
 
     if (which == OP_GPBYNAME) {
 #ifdef HAS_GETPROTOBYNAME
-        char* name = POPpbytex;
+	const char* const name = POPpbytex;
 	pent = PerlSock_getprotobyname(name);
 #else
 	DIE(aTHX_ PL_no_sock_func, "getprotobyname");
@@ -4790,7 +4673,7 @@ PP(pp_gprotoent)
     }
     else if (which == OP_GPBYNUMBER) {
 #ifdef HAS_GETPROTOBYNUMBER
-        int number = POPi;
+	const int number = POPi;
 	pent = PerlSock_getprotobynumber(number);
 #else
 	DIE(aTHX_ PL_no_sock_func, "getprotobynumber");
@@ -4850,29 +4733,21 @@ PP(pp_gservent)
 
     if (which == OP_GSBYNAME) {
 #ifdef HAS_GETSERVBYNAME
-	char *proto = POPpbytex;
-	char *name = POPpbytex;
-
-	if (proto && !*proto)
-	    proto = Nullch;
-
-	sent = PerlSock_getservbyname(name, proto);
+	const char * const proto = POPpbytex;
+	const char * const name = POPpbytex;
+	sent = PerlSock_getservbyname(name, (proto && !*proto) ? Nullch : proto);
 #else
 	DIE(aTHX_ PL_no_sock_func, "getservbyname");
 #endif
     }
     else if (which == OP_GSBYPORT) {
 #ifdef HAS_GETSERVBYPORT
-	char *proto = POPpbytex;
+	const char * const proto = POPpbytex;
 	unsigned short port = (unsigned short)POPu;
-
-	if (proto && !*proto)
-	    proto = Nullch;
-
 #ifdef HAS_HTONS
 	port = PerlSock_htons(port);
 #endif
-	sent = PerlSock_getservbyport(port, proto);
+	sent = PerlSock_getservbyport(port, (proto && !*proto) ? Nullch : proto);
 #else
 	DIE(aTHX_ PL_no_sock_func, "getservbyport");
 #endif
@@ -5094,7 +4969,7 @@ PP(pp_gpwent)
     switch (which) {
     case OP_GPWNAM:
       {
-	char* name = POPpbytex;
+	const char* const name = POPpbytex;
 	pwent  = getpwnam(name);
       }
       break;
@@ -5158,14 +5033,12 @@ PP(pp_gpwent)
 	 * has a different API than the Solaris/IRIX one. */
 #   if defined(HAS_GETSPNAM) && !defined(_AIX)
 	{
-	    struct spwd *spwent;
-	    int saverrno; /* Save and restore errno so that
+	    const int saverrno = errno;
+	    const struct spwd * const spwent = getspnam(pwent->pw_name);
+			  /* Save and restore errno so that
 			   * underprivileged attempts seem
 			   * to have never made the unsccessful
 			   * attempt to retrieve the shadow password. */
-
-	    saverrno = errno;
-	    spwent = getspnam(pwent->pw_name);
 	    errno = saverrno;
 	    if (spwent && spwent->sp_pwdp)
 		sv_setpv(sv, spwent->sp_pwdp);
@@ -5286,11 +5159,11 @@ PP(pp_ggrent)
     struct group *grent;
 
     if (which == OP_GGRNAM) {
-        char* name = POPpbytex;
+	const char* const name = POPpbytex;
 	grent = (struct group *)getgrnam(name);
     }
     else if (which == OP_GGRGID) {
-        Gid_t gid = POPi;
+	const Gid_t gid = POPi;
 	grent = (struct group *)getgrgid(gid);
     }
     else
@@ -5550,11 +5423,10 @@ static int
 lockf_emulate_flock(int fd, int operation)
 {
     int i;
-    int save_errno;
+    const int save_errno = errno;
     Off_t pos;
 
     /* flock locks entire file so for lockf we need to do the same	*/
-    save_errno = errno;
     pos = PerlLIO_lseek(fd, (Off_t)0, SEEK_CUR);    /* get pos to restore later */
     if (pos > 0)	/* is seekable and needs to be repositioned	*/
 	if (PerlLIO_lseek(fd, (Off_t)0, SEEK_SET) < 0)