Making 0 pointers to NULLs

Message-ID: <20051231050558.GA29093@petdance.com>

p4raw-id: //depot/perl@26558

14 files changed, 57 insertions, 52 deletions

diff --git a/doio.c b/doio.c
index a956af0dd6..fea7c5d9ee 100644
--- a/doio.c
+++ b/doio.c
@@ -1053,7 +1053,7 @@ Perl_do_eof(pTHX_ GV *gv)
 Off_t
 Perl_do_tell(pTHX_ GV *gv)
 {
-    register IO *io = 0;
+    register IO *io = NULL;
     register PerlIO *fp;
 
     if (gv && (io = GvIO(gv)) && (fp = IoIFP(io))) {
@@ -1072,7 +1072,7 @@ Perl_do_tell(pTHX_ GV *gv)
 bool
 Perl_do_seek(pTHX_ GV *gv, Off_t pos, int whence)
 {
-    register IO *io = 0;
+    register IO *io = NULL;
     register PerlIO *fp;
 
     if (gv && (io = GvIO(gv)) && (fp = IoIFP(io))) {
@@ -1091,7 +1091,7 @@ Perl_do_seek(pTHX_ GV *gv, Off_t pos, int whence)
 Off_t
 Perl_do_sysseek(pTHX_ GV *gv, Off_t pos, int whence)
 {
-    register IO *io = 0;
+    register IO *io = NULL;
     register PerlIO *fp;
 
     if (gv && (io = GvIO(gv)) && (fp = IoIFP(io)))
diff --git a/doop.c b/doop.c
index 75cbd3ec40..c16318244d 100644
--- a/doop.c
+++ b/doop.c
@@ -399,7 +399,8 @@ STATIC I32
 S_do_trans_count_utf8(pTHX_ SV *sv)
 {
     const U8 *s;
-    const U8 *start = 0, *send;
+    const U8 *start = NULL;
+    const U8 *send;
     I32 matches = 0;
     STRLEN len;
 
diff --git a/hv.c b/hv.c
index 918404c2de..a2e9443fe7 100644
--- a/hv.c
+++ b/hv.c
@@ -2257,7 +2257,7 @@ S_unshare_hek_or_pvn(pTHX_ const HEK *hek, const char *str, I32 len, U32 hash)
     bool is_utf8 = FALSE;
     int k_flags = 0;
     const char * const save = str;
-    struct shared_he *he = 0;
+    struct shared_he *he = NULL;
 
     if (hek) {
 	/* Find the shared he which is just before us in memory.  */
diff --git a/mg.c b/mg.c
index 44e48d224b..a5ee470454 100644
--- a/mg.c
+++ b/mg.c
@@ -1206,7 +1206,7 @@ Perl_magic_clearsig(pTHX_ SV *sv, MAGIC *mg)
     register const char * const s = MgPV_nolen_const(mg);
     PERL_UNUSED_ARG(sv);
     if (*s == '_') {
-	SV** svp = 0;
+	SV** svp = NULL;
 	if (strEQ(s,"__DIE__"))
 	    svp = &PL_diehook;
 	else if (strEQ(s,"__WARN__"))
@@ -1215,7 +1215,7 @@ Perl_magic_clearsig(pTHX_ SV *sv, MAGIC *mg)
 	    Perl_croak(aTHX_ "No such hook: %s", s);
 	if (svp && *svp) {
             SV * const to_dec = *svp;
-	    *svp = 0;
+	    *svp = NULL;
     	    SvREFCNT_dec(to_dec);
 	}
     }
@@ -1345,12 +1345,12 @@ Perl_magic_setsig(pTHX_ SV *sv, MAGIC *mg)
 {
     dVAR;
     I32 i;
-    SV** svp = 0;
+    SV** svp = NULL;
     /* Need to be careful with SvREFCNT_dec(), because that can have side
      * effects (due to closures). We must make sure that the new disposition
      * is in place before it is called.
      */
-    SV* to_dec = 0;
+    SV* to_dec = NULL;
     STRLEN len;
 #ifdef HAS_SIGPROCMASK
     sigset_t set, save;
@@ -1368,7 +1368,7 @@ Perl_magic_setsig(pTHX_ SV *sv, MAGIC *mg)
 	i = 0;
 	if (*svp) {
 	    to_dec = *svp;
-	    *svp = 0;
+	    *svp = NULL;
 	}
     }
     else {
diff --git a/pp.c b/pp.c
index d679f6ac21..1ebbf499d3 100644
--- a/pp.c
+++ b/pp.c
@@ -2918,7 +2918,7 @@ PP(pp_substr)
     const char *tmps;
     const I32 arybase = PL_curcop->cop_arybase;
     SV *repl_sv = NULL;
-    const char *repl = 0;
+    const char *repl = NULL;
     STRLEN repl_len;
     const int num_args = PL_op->op_private & 7;
     bool repl_need_utf8_upgrade = FALSE;
@@ -4018,7 +4018,7 @@ PP(pp_splice)
     I32 newlen;
     I32 after;
     I32 diff;
-    SV **tmparyval = 0;
+    SV **tmparyval = NULL;
     const MAGIC * const mg = SvTIED_mg((SV*)ary, PERL_MAGIC_tied);
 
     if (mg) {
diff --git a/pp_ctl.c b/pp_ctl.c
index 12f3f04bc6..f1c468eb0d 100644
--- a/pp_ctl.c
+++ b/pp_ctl.c
@@ -407,7 +407,7 @@ PP(pp_formline)
     bool item_is_utf8 = FALSE;
     bool targ_is_utf8 = FALSE;
     SV * nsv = NULL;
-    OP * parseres = 0;
+    OP * parseres = NULL;
     const char *fmt;
     bool oneline;
 
@@ -2250,12 +2250,12 @@ S_dofindlabel(pTHX_ OP *o, const char *label, OP **opstack, OP **oplimit)
 PP(pp_goto)
 {
     dVAR; dSP;
-    OP *retop = 0;
+    OP *retop = NULL;
     I32 ix;
     register PERL_CONTEXT *cx;
 #define GOTO_DEPTH 64
     OP *enterops[GOTO_DEPTH];
-    const char *label = 0;
+    const char *label = NULL;
     const bool do_dump = (PL_op->op_type == OP_DUMP);
     static const char must_have_label[] = "goto must have label";
 
@@ -2488,10 +2488,10 @@ PP(pp_goto)
 	label = cPVOP->op_pv;
 
     if (label && *label) {
-	OP *gotoprobe = 0;
+	OP *gotoprobe = NULL;
 	bool leaving_eval = FALSE;
 	bool in_block = FALSE;
-        PERL_CONTEXT *last_eval_cx = 0;
+	PERL_CONTEXT *last_eval_cx = NULL;
 
 	/* find label */
 
@@ -4275,7 +4275,7 @@ S_doparseform(pTHX_ SV *sv)
     bool postspace = FALSE;
     U32 *fops;
     register U32 *fpc;
-    U32 *linepc = 0;
+    U32 *linepc = NULL;
     register I32 arg;
     bool ischop;
     bool unchopnum = FALSE;
diff --git a/pp_hot.c b/pp_hot.c
index b999b23944..a222290cc6 100644
--- a/pp_hot.c
+++ b/pp_hot.c
@@ -1036,7 +1036,7 @@ PP(pp_aassign)
     I32 i;
     int magic;
     int duplicates = 0;
-    SV **firsthashrelem = 0;	/* "= 0" keeps gcc 2.95 quiet  */
+    SV **firsthashrelem = NULL;	/* "= 0" keeps gcc 2.95 quiet  */
 
 
     PL_delaymagic = DM_DELAY;		/* catch simultaneous items */
@@ -1419,9 +1419,11 @@ play_it_again:
     }
     else {
 	if (global) {
-	    MAGIC* mg = 0;
+	    MAGIC* mg;
 	    if (SvTYPE(TARG) >= SVt_PVMG && SvMAGIC(TARG))
 		mg = mg_find(TARG, PERL_MAGIC_regex_global);
+	    else
+		mg = NULL;
 	    if (!mg) {
 		sv_magic(TARG, (SV*)0, PERL_MAGIC_regex_global, Nullch, 0);
 		mg = mg_find(TARG, PERL_MAGIC_regex_global);
diff --git a/pp_sort.c b/pp_sort.c
index 1be5dce104..c5855ffafd 100644
--- a/pp_sort.c
+++ b/pp_sort.c
@@ -1464,7 +1464,7 @@ PP(pp_sort)
     AV* av = NULL;
     HV *stash;
     GV *gv;
-    CV *cv = 0;
+    CV *cv = NULL;
     I32 gimme = GIMME;
     OP* const nextop = PL_op->op_next;
     I32 overloading = 0;
diff --git a/regcomp.c b/regcomp.c
index 3dcc1522bd..74e55f9f83 100644
--- a/regcomp.c
+++ b/regcomp.c
@@ -3215,18 +3215,21 @@ S_reg(pTHX_ RExC_state_t *pRExC_state, I32 paren, I32 *flagp)
     register regnode *ret;		/* Will be the head of the group. */
     register regnode *br;
     register regnode *lastbr;
-    register regnode *ender = 0;
+    register regnode *ender = NULL;
     register I32 parno = 0;
-    I32 flags, oregflags = RExC_flags, have_branch = 0, open = 0;
+    I32 flags;
+    const I32 oregflags = RExC_flags;
+    I32 have_branch = 0;
+    I32 open = 0;
 
     /* for (?g), (?gc), and (?o) warnings; warning
        about (?c) will warn about (?g) -- japhy    */
 
-    I32 wastedflags = 0x00,
-        wasted_o    = 0x01,
-        wasted_g    = 0x02,
-        wasted_gc   = 0x02 | 0x04,
-        wasted_c    = 0x04;
+    I32 wastedflags = 0x00;
+    const I32 wasted_o  = 0x01;
+    const I32 wasted_g  = 0x02;
+    const I32 wasted_gc = 0x02 | 0x04;
+    const I32 wasted_c  = 0x04;
 
     char * parse_start = RExC_parse; /* MJD */
     char * const oregcomp_parse = RExC_parse;
@@ -3868,7 +3871,7 @@ S_regpiece(pTHX_ RExC_state_t *pRExC_state, I32 *flagp)
 STATIC regnode *
 S_regatom(pTHX_ RExC_state_t *pRExC_state, I32 *flagp)
 {
-    register regnode *ret = 0;
+    register regnode *ret = NULL;
     I32 flags;
     char *parse_start = RExC_parse;
 
@@ -4650,13 +4653,13 @@ S_regclass(pTHX_ RExC_state_t *pRExC_state)
     register regnode *ret;
     STRLEN numlen;
     IV namedclass;
-    char *rangebegin = 0;
+    char *rangebegin = NULL;
     bool need_class = 0;
     SV *listsv = NULL;
     register char *e;
     UV n;
     bool optimize_invert   = TRUE;
-    AV* unicode_alternate  = 0;
+    AV* unicode_alternate  = NULL;
 #ifdef EBCDIC
     UV literal_endpoint = 0;
 #endif
diff --git a/regexec.c b/regexec.c
index 13cc68bf49..17ddf11366 100644
--- a/regexec.c
+++ b/regexec.c
@@ -879,7 +879,7 @@ Perl_re_intuit_start(pTHX_ regexp *prog, SV *sv, char *strpos,
         s = find_byclass(prog, prog->regstclass, s, endpos, 1);
 	if (!s) {
 #ifdef DEBUGGING
-	    const char *what = 0;
+	    const char *what = NULL;
 #endif
 	    if (endpos == strend) {
 		DEBUG_EXECUTE_r( PerlIO_printf(Perl_debug_log,
@@ -2400,8 +2400,8 @@ S_regmatch(pTHX_ regnode *prog)
     I32 unwind = 0;
 
     /* used by the trie code */
-    SV                 *sv_accept_buff = 0;  /* accepting states we have traversed */
-    reg_trie_accepted  *accept_buff = 0;     /* "" */
+    SV                 *sv_accept_buff = NULL; /* accepting states we have traversed */
+    reg_trie_accepted  *accept_buff = NULL;  /* "" */
     reg_trie_data      *trie;                /* what trie are we using right now */
     U32 accepted = 0;                        /* how many accepting states we have seen*/
 
diff --git a/sv.c b/sv.c
index b707a73bfd..cb3e193475 100644
--- a/sv.c
+++ b/sv.c
@@ -3085,7 +3085,7 @@ Perl_sv_setsv_flags(pTHX_ SV *dstr, register SV *sstr, I32 flags)
 	if (dtype >= SVt_PV) {
 	    if (dtype == SVt_PVGV) {
 		SV * const sref = SvREFCNT_inc(SvRV(sstr));
-		SV *dref = 0;
+		SV *dref = NULL;
 		const int intro = GvINTRO(dstr);
 
 #ifdef GV_UNIQUE_CHECK
@@ -5197,15 +5197,13 @@ Perl_sv_pos_u2b(pTHX_ register SV *sv, I32* offsetp, I32* lenp)
     start = (U8*)SvPV_const(sv, len);
     if (len) {
 	STRLEN boffset = 0;
-	STRLEN *cache = 0;
+	STRLEN *cache = NULL;
 	const U8 *s = start;
 	I32 uoffset = *offsetp;
 	const U8 * const send = s + len;
-	MAGIC *mg = 0;
-	bool found = FALSE;
+	MAGIC *mg = NULL;
+	bool found = utf8_mg_pos(sv, &mg, &cache, 0, offsetp, *offsetp, &s, start, send);
 
-         if (utf8_mg_pos(sv, &mg, &cache, 0, offsetp, *offsetp, &s, start, send))
-             found = TRUE;
 	 if (!found && uoffset > 0) {
 	      while (s < send && uoffset--)
 		   s += UTF8SKIP(s);
@@ -5955,7 +5953,7 @@ thats_really_all_folks:
     {
        /*The big, slow, and stupid way. */
 #ifdef USE_HEAP_INSTEAD_OF_STACK	/* Even slower way. */
-	STDCHAR *buf = 0;
+	STDCHAR *buf = NULL;
 	Newx(buf, 8192, STDCHAR);
 	assert(buf);
 #else
@@ -9528,7 +9526,7 @@ Perl_sv_dup(pTHX_ const SV *sstr, CLONE_PARAMS* param)
 		break;
 	    case SVt_PVHV:
 		{
-		    HEK *hvname = 0;
+		    HEK *hvname = NULL;
 
 		    if (HvARRAY((HV*)sstr)) {
 			STRLEN i = 0;
diff --git a/toke.c b/toke.c
index b8f3c71e15..c9a5b75ea8 100644
--- a/toke.c
+++ b/toke.c
@@ -4116,8 +4116,8 @@ Perl_yylex(pTHX)
       keylookup: {
 	I32 tmp;
 	I32 orig_keyword = 0;
-	GV *gv = Nullgv;
-	GV **gvp = 0;
+	GV *gv = NULL;
+	GV **gvp = NULL;
 
 	PL_bufptr = s;
 	s = scan_word(s, PL_tokenbuf, sizeof PL_tokenbuf, FALSE, &len);
@@ -4159,8 +4159,8 @@ Perl_yylex(pTHX)
 	}
 
 	if (tmp < 0) {			/* second-class keyword? */
-	    GV *ogv = Nullgv;	/* override (winner) */
-	    GV *hgv = Nullgv;	/* hidden (loser) */
+	    GV *ogv = NULL;	/* override (winner) */
+	    GV *hgv = NULL;	/* hidden (loser) */
 	    if (PL_expect != XOPERATOR && (*s != ':' || s[1] != ':')) {
 		CV *cv;
 		if ((gv = gv_fetchpv(PL_tokenbuf, 0, SVt_PVCV)) &&
@@ -10412,7 +10412,7 @@ Perl_scan_num(pTHX_ const char *start, YYSTYPE* lvalp)
     NV nv;				/* number read, as a double */
     SV *sv = Nullsv;			/* place to put the converted number */
     bool floatit;			/* boolean: int or float? */
-    const char *lastub = 0;		/* position of last underbar */
+    const char *lastub = NULL;		/* position of last underbar */
     static char const number_too_long[] = "Number too long";
 
     /* We use the first character to decide what type of number this is */
diff --git a/utf8.c b/utf8.c
index 23562557f6..3d9f00f4be 100644
--- a/utf8.c
+++ b/utf8.c
@@ -2235,9 +2235,12 @@ Perl_ibcmp_utf8(pTHX_ const char *s1, char **pe1, register UV l1, bool u1, const
 {
      register const U8 *p1  = (const U8*)s1;
      register const U8 *p2  = (const U8*)s2;
-     register const U8 *f1 = 0, *f2 = 0;
-     register U8 *e1 = 0, *q1 = 0;
-     register U8 *e2 = 0, *q2 = 0;
+     register const U8 *f1 = NULL;
+     register U8 *f2 = NULL;
+     register U8 *e1 = NULL;
+     register U8 *q1 = NULL;
+     register U8 *e2 = NULL;
+     register U8 *q2 = NULL;
      STRLEN n1 = 0, n2 = 0;
      U8 foldbuf1[UTF8_MAXBYTES_CASE+1];
      U8 foldbuf2[UTF8_MAXBYTES_CASE+1];
diff --git a/util.c b/util.c
index c4fddee299..020663f28c 100644
--- a/util.c
+++ b/util.c
@@ -139,7 +139,6 @@ Perl_safesysrealloc(Malloc_t where,MEM_SIZE size)
     where = (Malloc_t)((char*)where-sTHX);
     size += sTHX;
     if (((struct perl_memory_debug_header *)where)->interpreter != aTHX) {
-	/* int *nowhere = NULL; *nowhere = 0; */
         Perl_croak_nocontext("panic: realloc from wrong pool");
     }
 #  ifdef PERL_POISON
@@ -190,7 +189,6 @@ Perl_safesysfree(Malloc_t where)
 #ifdef PERL_TRACK_MEMPOOL
         where = (Malloc_t)((char*)where-sTHX);
         if (((struct perl_memory_debug_header *)where)->interpreter != aTHX) {
-	    /* int *nowhere = NULL; *nowhere = 0; */
             Perl_croak_nocontext("panic: free from wrong pool");
 	}
 #  ifdef PERL_POISON