/* mg.c
*
* Copyright (C) 1991, 1992, 1993, 1994, 1995, 1996, 1997, 1998, 1999,
- * 2000, 2001, 2002, 2003, by Larry Wall and others
+ * 2000, 2001, 2002, 2003, 2004, 2005 by Larry Wall and others
*
* You may distribute under the terms of either the GNU General Public
* License or the Artistic License, as specified in the README file.
/*
=head1 Magical Functions
+
+"Magic" is special data attached to SV structures in order to give them
+"magical" properties. When any Perl code tries to read from, or assign to,
+an SV marked as magical, it calls the 'get' or 'set' function associated
+with that SV's magic. A get is called prior to reading an SV, in order to
+give it a chance to update its internal value (get on $. writes the line
+number of the last read filehandle into to the SV's IV slot), while
+set is called after an SV has been written to, in order to allow it to make
+use of its changed value (set on $/ copies the SV's new value to the
+PL_rs global variable).
+
+Magic is implemented as a linked list of MAGIC structures attached to the
+SV. Each MAGIC struct holds the type of the magic, a pointer to an array
+of functions that implement the get(), set(), length() etc functions,
+plus space for some flags and pointers. For example, a tied variable has
+a MAGIC structure that contains a pointer to the object associated with the
+tie.
+
*/
#include "EXTERN.h"
# define FAKE_DEFAULT_SIGNAL_HANDLERS
#endif
-static void restore_magic(pTHX_ void *p);
-static void unwind_handler_stack(pTHX_ void *p);
+static void restore_magic(pTHX_ const void *p);
+static void unwind_handler_stack(pTHX_ const void *p);
#ifdef __Lynx__
/* Missing protos on LynxOS */
{
MAGIC* mg;
for (mg = SvMAGIC(sv); mg; mg = mg->mg_moremagic) {
- MGVTBL* vtbl = mg->mg_virtual;
+ const MGVTBL* const vtbl = mg->mg_virtual;
if (vtbl) {
if (vtbl->svt_get && !(mg->mg_flags & MGf_GSKIP))
SvGMAGICAL_on(sv);
int
Perl_mg_get(pTHX_ SV *sv)
{
+ const I32 mgs_ix = SSNEW(sizeof(MGS));
+ const bool was_temp = SvTEMP(sv);
int new = 0;
MAGIC *newmg, *head, *cur, *mg;
- I32 mgs_ix = SSNEW(sizeof(MGS));
+ /* guard against sv having being freed midway by holding a private
+ reference. */
+
+ /* sv_2mortal has this side effect of turning on the TEMP flag, which can
+ cause the SV's buffer to get stolen (and maybe other stuff).
+ So restore it.
+ */
+ sv_2mortal(SvREFCNT_inc(sv));
+ if (!was_temp) {
+ SvTEMP_off(sv);
+ }
save_magic(mgs_ix, sv);
newmg = cur = head = mg = SvMAGIC(sv);
while (mg) {
- MGVTBL *vtbl = mg->mg_virtual;
+ const MGVTBL * const vtbl = mg->mg_virtual;
if (!(mg->mg_flags & MGf_GSKIP) && vtbl && vtbl->svt_get) {
CALL_FPTR(vtbl->svt_get)(aTHX_ sv, mg);
- /* guard against sv having been freed */
- if (SvTYPE(sv) == SVTYPEMASK) {
- Perl_croak(aTHX_ "Tied variable freed while still in use");
- }
/* guard against magic having been deleted - eg FETCH calling
* untie */
if (!SvMAGIC(sv))
}
restore_magic(aTHX_ INT2PTR(void *, (IV)mgs_ix));
+
+ if (SvREFCNT(sv) == 1) {
+ /* We hold the last reference to this SV, which implies that the
+ SV was deleted as a side effect of the routines we called. */
+ SvOK_off(sv);
+ }
return 0;
}
int
Perl_mg_set(pTHX_ SV *sv)
{
- I32 mgs_ix;
+ const I32 mgs_ix = SSNEW(sizeof(MGS));
MAGIC* mg;
MAGIC* nextmg;
- mgs_ix = SSNEW(sizeof(MGS));
save_magic(mgs_ix, sv);
for (mg = SvMAGIC(sv); mg; mg = nextmg) {
STRLEN len;
for (mg = SvMAGIC(sv); mg; mg = mg->mg_moremagic) {
- MGVTBL* vtbl = mg->mg_virtual;
+ const MGVTBL * const vtbl = mg->mg_virtual;
if (vtbl && vtbl->svt_len) {
- I32 mgs_ix;
-
- mgs_ix = SSNEW(sizeof(MGS));
+ const I32 mgs_ix = SSNEW(sizeof(MGS));
save_magic(mgs_ix, sv);
/* omit MGf_GSKIP -- not changed here */
len = CALL_FPTR(vtbl->svt_len)(aTHX_ sv, mg);
}
}
- if (DO_UTF8(sv))
- {
+ if (DO_UTF8(sv)) {
U8 *s = (U8*)SvPV(sv, len);
len = Perl_utf8_length(aTHX_ s, s + len);
}
Perl_mg_size(pTHX_ SV *sv)
{
MAGIC* mg;
- I32 len;
for (mg = SvMAGIC(sv); mg; mg = mg->mg_moremagic) {
- MGVTBL* vtbl = mg->mg_virtual;
+ const MGVTBL* const vtbl = mg->mg_virtual;
if (vtbl && vtbl->svt_len) {
- I32 mgs_ix;
-
- mgs_ix = SSNEW(sizeof(MGS));
+ const I32 mgs_ix = SSNEW(sizeof(MGS));
+ I32 len;
save_magic(mgs_ix, sv);
/* omit MGf_GSKIP -- not changed here */
len = CALL_FPTR(vtbl->svt_len)(aTHX_ sv, mg);
switch(SvTYPE(sv)) {
case SVt_PVAV:
- len = AvFILLp((AV *) sv); /* Fallback to non-tied array */
- return len;
+ return AvFILLp((AV *) sv); /* Fallback to non-tied array */
case SVt_PVHV:
/* FIXME */
default:
int
Perl_mg_clear(pTHX_ SV *sv)
{
- I32 mgs_ix;
+ const I32 mgs_ix = SSNEW(sizeof(MGS));
MAGIC* mg;
- mgs_ix = SSNEW(sizeof(MGS));
save_magic(mgs_ix, sv);
for (mg = SvMAGIC(sv); mg; mg = mg->mg_moremagic) {
- MGVTBL* vtbl = mg->mg_virtual;
+ const MGVTBL* const vtbl = mg->mg_virtual;
/* omit GSKIP -- never set here */
if (vtbl && vtbl->svt_clear)
*/
MAGIC*
-Perl_mg_find(pTHX_ SV *sv, int type)
+Perl_mg_find(pTHX_ const SV *sv, int type)
{
- MAGIC* mg;
- if (!sv)
- return 0;
- for (mg = SvMAGIC(sv); mg; mg = mg->mg_moremagic) {
- if (mg->mg_type == type)
- return mg;
+ if (sv) {
+ MAGIC *mg;
+ for (mg = SvMAGIC(sv); mg; mg = mg->mg_moremagic) {
+ if (mg->mg_type == type)
+ return mg;
+ }
}
return 0;
}
int count = 0;
MAGIC* mg;
for (mg = SvMAGIC(sv); mg; mg = mg->mg_moremagic) {
- MGVTBL* vtbl = mg->mg_virtual;
+ const MGVTBL* const vtbl = mg->mg_virtual;
if ((mg->mg_flags & MGf_COPY) && vtbl->svt_copy){
count += CALL_FPTR(vtbl->svt_copy)(aTHX_ sv, mg, nsv, key, klen);
}
MAGIC* mg;
MAGIC* moremagic;
for (mg = SvMAGIC(sv); mg; mg = moremagic) {
- MGVTBL* vtbl = mg->mg_virtual;
+ const MGVTBL* const vtbl = mg->mg_virtual;
moremagic = mg->mg_moremagic;
if (vtbl && vtbl->svt_free)
CALL_FPTR(vtbl->svt_free)(aTHX_ sv, mg);
U32
Perl_magic_regdata_cnt(pTHX_ SV *sv, MAGIC *mg)
{
- register REGEXP *rx;
+ register const REGEXP *rx;
if (PL_curpm && (rx = PM_GETRE(PL_curpm))) {
if (mg->mg_obj) /* @+ */
int
Perl_magic_regdatum_get(pTHX_ SV *sv, MAGIC *mg)
{
- register I32 paren;
- register I32 s;
- register I32 i;
register REGEXP *rx;
- I32 t;
if (PL_curpm && (rx = PM_GETRE(PL_curpm))) {
- paren = mg->mg_len;
+ register const I32 paren = mg->mg_len;
+ register I32 s;
+ register I32 t;
if (paren < 0)
return 0;
if (paren <= (I32)rx->nparens &&
(s = rx->startp[paren]) != -1 &&
(t = rx->endp[paren]) != -1)
{
+ register I32 i;
if (mg->mg_obj) /* @+ */
i = t;
else /* @- */
}
else {
if (ckWARN(WARN_UNINITIALIZED))
- report_uninit();
+ report_uninit(sv);
}
}
else {
if (ckWARN(WARN_UNINITIALIZED))
- report_uninit();
+ report_uninit(sv);
}
return 0;
case '+':
case '\004': /* ^D */
sv_setiv(sv, (IV)(PL_debug & DEBUG_MASK));
-#if defined(YYDEBUG) && defined(DEBUGGING)
- PL_yydebug = DEBUG_p_TEST;
-#endif
break;
case '\005': /* ^E */
if (*(mg->mg_ptr+1) == '\0') {
case '\023': /* ^S */
if (*(mg->mg_ptr+1) == '\0') {
if (PL_lex_state != LEX_NOTPARSING)
- (void)SvOK_off(sv);
+ SvOK_off(sv);
else if (PL_in_eval)
sv_setiv(sv, PL_in_eval & ~(EVAL_INREQUIRE));
else
? (PL_taint_warn || PL_unsafe ? -1 : 1)
: 0);
break;
- case '\025': /* $^UNICODE */
+ case '\025': /* $^UNICODE, $^UTF8LOCALE */
if (strEQ(mg->mg_ptr, "\025NICODE"))
sv_setuv(sv, (UV) PL_unicode);
+ else if (strEQ(mg->mg_ptr, "\025TF8LOCALE"))
+ sv_setuv(sv, (UV) PL_utf8locale);
break;
case '\027': /* ^W & $^WARNING_BITS */
if (*(mg->mg_ptr+1) == '\0')
# endif
{
# ifndef PERL_USE_SAFE_PUTENV
+ if (!PL_use_safe_putenv) {
I32 i;
if (environ == PL_origenviron)
else
for (i = 0; environ[i]; i++)
safesysfree(environ[i]);
+ }
# endif /* PERL_USE_SAFE_PUTENV */
environ[0] = Nullch;
/* XXX Some of this code was copied from Perl_magic_setsig. A little
* refactoring might be in order.
*/
- register char *s;
STRLEN n_a;
SV* to_dec;
- s = MgPV(mg,n_a);
+ register const char *s = MgPV(mg,n_a);
if (*s == '_') {
SV** svp;
if (strEQ(s,"__DIE__"))
int
Perl_magic_setsig(pTHX_ SV *sv, MAGIC *mg)
{
- register char *s;
I32 i;
SV** svp = 0;
/* Need to be careful with SvREFCNT_dec(), because that can have side
SV* save_sv;
#endif
- s = MgPV(mg,len);
+ register const char *s = MgPV(mg,len);
if (*s == '_') {
if (strEQ(s,"__DIE__"))
svp = &PL_diehook;
Perl_magic_nextpack(pTHX_ SV *sv, MAGIC *mg, SV *key)
{
dSP;
- const char *meth = SvOK(key) ? "NEXTKEY" : "FIRSTKEY";
+ const char * const meth = SvOK(key) ? "NEXTKEY" : "FIRSTKEY";
ENTER;
SAVETMPS;
return 0;
}
}
- (void)SvOK_off(sv);
+ SvOK_off(sv);
return 0;
}
int
Perl_magic_setglob(pTHX_ SV *sv, MAGIC *mg)
{
- register char *s;
GV* gv;
- STRLEN n_a;
-
+
if (!SvOK(sv))
return 0;
- s = SvPV(sv, n_a);
- if (*s == '*' && s[1])
- s++;
- gv = gv_fetchpv(s,TRUE, SVt_PVGV);
+ gv = gv_fetchsv(sv,TRUE, SVt_PVGV);
if (sv == (SV*)gv)
return 0;
if (GvGP(sv))
Perl_magic_getsubstr(pTHX_ SV *sv, MAGIC *mg)
{
STRLEN len;
- SV *lsv = LvTARG(sv);
- char *tmps = SvPV(lsv,len);
+ SV * const lsv = LvTARG(sv);
+ const char * const tmps = SvPV(lsv,len);
I32 offs = LvTARGOFF(sv);
I32 rem = LvTARGLEN(sv);
sv_utf8_upgrade(lsv);
sv_pos_u2b(lsv, &lvoff, &lvlen);
sv_insert(lsv, lvoff, lvlen, tmps, len);
+ LvTARGLEN(sv) = sv_len_utf8(sv);
SvUTF8_on(lsv);
}
else if (lsv && SvUTF8(lsv)) {
sv_pos_u2b(lsv, &lvoff, &lvlen);
+ LvTARGLEN(sv) = len;
tmps = (char*)bytes_to_utf8((U8*)tmps, &len);
sv_insert(lsv, lvoff, lvlen, tmps, len);
Safefree(tmps);
}
- else
- sv_insert(lsv, lvoff, lvlen, tmps, len);
+ else {
+ sv_insert(lsv, lvoff, lvlen, tmps, len);
+ LvTARGLEN(sv) = len;
+ }
+
return 0;
}
int
Perl_magic_getvec(pTHX_ SV *sv, MAGIC *mg)
{
- SV *lsv = LvTARG(sv);
+ SV * const lsv = LvTARG(sv);
if (!lsv) {
- (void)SvOK_off(sv);
+ SvOK_off(sv);
return 0;
}
Perl_croak(aTHX_ "panic: magic_killbackrefs");
/* XXX Should we check that it hasn't changed? */
SvRV(svp[i]) = 0;
- (void)SvOK_off(svp[i]);
+ SvOK_off(svp[i]);
SvWEAKREF_off(svp[i]);
svp[i] = Nullsv;
}
int
Perl_magic_setuvar(pTHX_ SV *sv, MAGIC *mg)
{
- struct ufuncs *uf = (struct ufuncs *)mg->mg_ptr;
+ const struct ufuncs * const uf = (struct ufuncs *)mg->mg_ptr;
if (uf && uf->uf_set)
(*uf->uf_set)(aTHX_ uf->uf_index, sv);
case '\004': /* ^D */
#ifdef DEBUGGING
s = SvPV_nolen(sv);
- PL_debug = get_debug_opts(&s) | DEBUG_TOP_FLAG;
+ PL_debug = get_debug_opts(&s, 0) | DEBUG_TOP_FLAG;
DEBUG_x(dump_all());
#else
PL_debug = (SvIOK(sv) ? SvIVX(sv) : sv_2iv(sv)) | DEBUG_TOP_FLAG;
if (PL_inplace)
Safefree(PL_inplace);
if (SvOK(sv))
- PL_inplace = savepv(SvPV(sv,len));
+ PL_inplace = savesvpv(sv);
else
PL_inplace = Nullch;
break;
case '\017': /* ^O */
if (*(mg->mg_ptr+1) == '\0') {
- if (PL_osname)
+ if (PL_osname) {
Safefree(PL_osname);
+ PL_osname = Nullch;
+ }
if (SvOK(sv)) {
TAINT_PROPER("assigning to $^O");
- PL_osname = savepv(SvPV(sv,len));
+ PL_osname = savesvpv(sv);
}
- else
- PL_osname = Nullch;
}
else if (strEQ(mg->mg_ptr, "\017PEN")) {
if (!PL_compiling.cop_io)
STRLEN len, i;
int accumulate = 0 ;
int any_fatals = 0 ;
- char * ptr = (char*)SvPV(sv, len) ;
+ const char * const ptr = (char*)SvPV(sv, len) ;
for (i = 0 ; i < len ; ++i) {
accumulate |= ptr[i] ;
any_fatals |= (ptr[i] & 0xAA) ;
break;
case '^':
Safefree(IoTOP_NAME(GvIOp(PL_defoutgv)));
- IoTOP_NAME(GvIOp(PL_defoutgv)) = s = savepv(SvPV(sv,len));
- IoTOP_GV(GvIOp(PL_defoutgv)) = gv_fetchpv(s,TRUE, SVt_PVIO);
+ IoTOP_NAME(GvIOp(PL_defoutgv)) = s = savesvpv(sv);
+ IoTOP_GV(GvIOp(PL_defoutgv)) = gv_fetchsv(sv,TRUE, SVt_PVIO);
break;
case '~':
Safefree(IoFMT_NAME(GvIOp(PL_defoutgv)));
- IoFMT_NAME(GvIOp(PL_defoutgv)) = s = savepv(SvPV(sv,len));
- IoFMT_GV(GvIOp(PL_defoutgv)) = gv_fetchpv(s,TRUE, SVt_PVIO);
+ IoFMT_NAME(GvIOp(PL_defoutgv)) = s = savesvpv(sv);
+ IoFMT_GV(GvIOp(PL_defoutgv)) = gv_fetchsv(sv,TRUE, SVt_PVIO);
break;
case '=':
IoPAGE_LEN(GvIOp(PL_defoutgv)) = (SvIOK(sv) ? SvIVX(sv) : sv_2iv(sv));
case '#':
if (PL_ofmt)
Safefree(PL_ofmt);
- PL_ofmt = savepv(SvPV(sv,len));
+ PL_ofmt = savesvpv(sv);
break;
case '[':
PL_compiling.cop_arybase = SvIOK(sv) ? SvIVX(sv) : sv_2iv(sv);
case ')':
#ifdef HAS_SETGROUPS
{
- char *p = SvPV(sv, len);
+ const char *p = SvPV(sv, len);
Groups_t gary[NGROUPS];
while (isSPACE(*p))
}
I32
-Perl_whichsig(pTHX_ char *sig)
+Perl_whichsig(pTHX_ const char *sig)
{
register char **sigv;
flags |= 1;
if (PL_markstack_ptr < PL_markstack_max - 2)
flags |= 4;
- if (PL_retstack_ix < PL_retstack_max - 2)
- flags |= 8;
if (PL_scopestack_ix < PL_scopestack_max - 3)
flags |= 16;
}
if (flags & 4)
PL_markstack_ptr++; /* Protect mark. */
- if (flags & 8) {
- PL_retstack_ix++;
- PL_retstack[PL_retstack_ix] = NULL;
- }
if (flags & 16)
PL_scopestack_ix += 1;
/* sv_2cv is too complicated, try a simpler variant first: */
(void)rsignal(sig, PL_csighandlerp);
#endif
#endif /* !PERL_MICRO */
- Perl_die(aTHX_ Nullformat);
+ DieNull;
}
cleanup:
if (flags & 1)
PL_savestack_ix -= 8; /* Unprotect save in progress. */
if (flags & 4)
PL_markstack_ptr--;
- if (flags & 8)
- PL_retstack_ix--;
if (flags & 16)
PL_scopestack_ix -= 1;
if (flags & 64)
static void
-restore_magic(pTHX_ void *p)
+restore_magic(pTHX_ const void *p)
{
MGS* mgs = SSPTR(PTR2IV(p), MGS*);
SV* sv = mgs->mgs_sv;
}
static void
-unwind_handler_stack(pTHX_ void *p)
+unwind_handler_stack(pTHX_ const void *p)
{
- U32 flags = *(U32*)p;
+ const U32 flags = *(U32*)p;
if (flags & 1)
PL_savestack_ix -= 5; /* Unprotect save in progress. */