################################################################################
##
##  Version 3.x, Copyright (C) 2004-2013, Marcus Holland-Moritz.
##  Version 2.x, Copyright (C) 2001, Paul Marquess.
##  Version 1.x, Copyright (C) 1999, Kenneth Albanowski.
##
##  This program is free software; you can redistribute it and/or
##  modify it under the same terms as Perl itself.
##
################################################################################

=provides

mg_findext
sv_unmagicext

__UNDEFINED__
/sv_\w+_mg/
sv_magic_portable
MUTABLE_PTR
MUTABLE_SV

=implementation

__UNDEFINED__  SvGETMAGIC(x) STMT_START { if (SvGMAGICAL(x)) mg_get(x); } STMT_END

/* Some random bits for sv_unmagicext. These should probably be pulled in for
   real and organized at some point */

__UNDEFINED__  HEf_SVKEY   -2

#ifndef MUTABLE_PTR
#if defined(__GNUC__) && !defined(PERL_GCC_BRACE_GROUPS_FORBIDDEN)
#  define MUTABLE_PTR(p) ({ void *_p = (p); _p; })
#else
#  define MUTABLE_PTR(p) ((void *) (p))
#endif
#endif

__UNDEFINED__ MUTABLE_SV(p)   ((SV *)MUTABLE_PTR(p))

/* end of random bits */

__UNDEFINED__  PERL_MAGIC_sv              '\0'
__UNDEFINED__  PERL_MAGIC_overload        'A'
__UNDEFINED__  PERL_MAGIC_overload_elem   'a'
__UNDEFINED__  PERL_MAGIC_overload_table  'c'
__UNDEFINED__  PERL_MAGIC_bm              'B'
__UNDEFINED__  PERL_MAGIC_regdata         'D'
__UNDEFINED__  PERL_MAGIC_regdatum        'd'
__UNDEFINED__  PERL_MAGIC_env             'E'
__UNDEFINED__  PERL_MAGIC_envelem         'e'
__UNDEFINED__  PERL_MAGIC_fm              'f'
__UNDEFINED__  PERL_MAGIC_regex_global    'g'
__UNDEFINED__  PERL_MAGIC_isa             'I'
__UNDEFINED__  PERL_MAGIC_isaelem         'i'
__UNDEFINED__  PERL_MAGIC_nkeys           'k'
__UNDEFINED__  PERL_MAGIC_dbfile          'L'
__UNDEFINED__  PERL_MAGIC_dbline          'l'
__UNDEFINED__  PERL_MAGIC_mutex           'm'
__UNDEFINED__  PERL_MAGIC_shared          'N'
__UNDEFINED__  PERL_MAGIC_shared_scalar   'n'
__UNDEFINED__  PERL_MAGIC_collxfrm        'o'
__UNDEFINED__  PERL_MAGIC_tied            'P'
__UNDEFINED__  PERL_MAGIC_tiedelem        'p'
__UNDEFINED__  PERL_MAGIC_tiedscalar      'q'
__UNDEFINED__  PERL_MAGIC_qr              'r'
__UNDEFINED__  PERL_MAGIC_sig             'S'
__UNDEFINED__  PERL_MAGIC_sigelem         's'
__UNDEFINED__  PERL_MAGIC_taint           't'
__UNDEFINED__  PERL_MAGIC_uvar            'U'
__UNDEFINED__  PERL_MAGIC_uvar_elem       'u'
__UNDEFINED__  PERL_MAGIC_vstring         'V'
__UNDEFINED__  PERL_MAGIC_vec             'v'
__UNDEFINED__  PERL_MAGIC_utf8            'w'
__UNDEFINED__  PERL_MAGIC_substr          'x'
__UNDEFINED__  PERL_MAGIC_defelem         'y'
__UNDEFINED__  PERL_MAGIC_glob            '*'
__UNDEFINED__  PERL_MAGIC_arylen          '#'
__UNDEFINED__  PERL_MAGIC_pos             '.'
__UNDEFINED__  PERL_MAGIC_backref         '<'
__UNDEFINED__  PERL_MAGIC_ext             '~'

/* That's the best we can do... */
__UNDEFINED__  sv_catpvn_nomg     sv_catpvn
__UNDEFINED__  sv_catsv_nomg      sv_catsv
__UNDEFINED__  sv_setsv_nomg      sv_setsv
__UNDEFINED__  sv_pvn_nomg        sv_pvn
__UNDEFINED__  SvIV_nomg          SvIV
__UNDEFINED__  SvUV_nomg          SvUV

#ifndef sv_catpv_mg
#  define sv_catpv_mg(sv, ptr)          \
   STMT_START {                         \
     SV *TeMpSv = sv;                   \
     sv_catpv(TeMpSv,ptr);              \
     SvSETMAGIC(TeMpSv);                \
   } STMT_END
#endif

#ifndef sv_catpvn_mg
#  define sv_catpvn_mg(sv, ptr, len)    \
   STMT_START {                         \
     SV *TeMpSv = sv;                   \
     sv_catpvn(TeMpSv,ptr,len);         \
     SvSETMAGIC(TeMpSv);                \
   } STMT_END
#endif

#ifndef sv_catsv_mg
#  define sv_catsv_mg(dsv, ssv)         \
   STMT_START {                         \
     SV *TeMpSv = dsv;                  \
     sv_catsv(TeMpSv,ssv);              \
     SvSETMAGIC(TeMpSv);                \
   } STMT_END
#endif

#ifndef sv_setiv_mg
#  define sv_setiv_mg(sv, i)            \
   STMT_START {                         \
     SV *TeMpSv = sv;                   \
     sv_setiv(TeMpSv,i);                \
     SvSETMAGIC(TeMpSv);                \
   } STMT_END
#endif

#ifndef sv_setnv_mg
#  define sv_setnv_mg(sv, num)          \
   STMT_START {                         \
     SV *TeMpSv = sv;                   \
     sv_setnv(TeMpSv,num);              \
     SvSETMAGIC(TeMpSv);                \
   } STMT_END
#endif

#ifndef sv_setpv_mg
#  define sv_setpv_mg(sv, ptr)          \
   STMT_START {                         \
     SV *TeMpSv = sv;                   \
     sv_setpv(TeMpSv,ptr);              \
     SvSETMAGIC(TeMpSv);                \
   } STMT_END
#endif

#ifndef sv_setpvn_mg
#  define sv_setpvn_mg(sv, ptr, len)    \
   STMT_START {                         \
     SV *TeMpSv = sv;                   \
     sv_setpvn(TeMpSv,ptr,len);         \
     SvSETMAGIC(TeMpSv);                \
   } STMT_END
#endif

#ifndef sv_setsv_mg
#  define sv_setsv_mg(dsv, ssv)         \
   STMT_START {                         \
     SV *TeMpSv = dsv;                  \
     sv_setsv(TeMpSv,ssv);              \
     SvSETMAGIC(TeMpSv);                \
   } STMT_END
#endif

#ifndef sv_setuv_mg
#  define sv_setuv_mg(sv, i)            \
   STMT_START {                         \
     SV *TeMpSv = sv;                   \
     sv_setuv(TeMpSv,i);                \
     SvSETMAGIC(TeMpSv);                \
   } STMT_END
#endif

#ifndef sv_usepvn_mg
#  define sv_usepvn_mg(sv, ptr, len)    \
   STMT_START {                         \
     SV *TeMpSv = sv;                   \
     sv_usepvn(TeMpSv,ptr,len);         \
     SvSETMAGIC(TeMpSv);                \
   } STMT_END
#endif

__UNDEFINED__  SvVSTRING_mg(sv)  (SvMAGICAL(sv) ? mg_find(sv, PERL_MAGIC_vstring) : NULL)

/* Hint: sv_magic_portable
 * This is a compatibility function that is only available with
 * Devel::PPPort. It is NOT in the perl core.
 * Its purpose is to mimic the 5.8.0 behaviour of sv_magic() when
 * it is being passed a name pointer with namlen == 0. In that
 * case, perl 5.8.0 and later store the pointer, not a copy of it.
 * The compatibility can be provided back to perl 5.004. With
 * earlier versions, the code will not compile.
 */

#if { VERSION < 5.004 }

  /* code that uses sv_magic_portable will not compile */

#elif { VERSION < 5.8.0 }

#  define sv_magic_portable(sv, obj, how, name, namlen)     \
   STMT_START {                                             \
     SV *SvMp_sv = (sv);                                    \
     char *SvMp_name = (char *) (name);                     \
     I32 SvMp_namlen = (namlen);                            \
     if (SvMp_name && SvMp_namlen == 0)                     \
     {                                                      \
       MAGIC *mg;                                           \
       sv_magic(SvMp_sv, obj, how, 0, 0);                   \
       mg = SvMAGIC(SvMp_sv);                               \
       mg->mg_len = -42; /* XXX: this is the tricky part */ \
       mg->mg_ptr = SvMp_name;                              \
     }                                                      \
     else                                                   \
     {                                                      \
       sv_magic(SvMp_sv, obj, how, SvMp_name, SvMp_namlen); \
     }                                                      \
   } STMT_END

#else

#  define sv_magic_portable(a, b, c, d, e)  sv_magic(a, b, c, d, e)

#endif

#if !defined(mg_findext)
#if { NEED mg_findext }

MAGIC *
mg_findext(SV * sv, int type, const MGVTBL *vtbl) {
    if (sv) {
        MAGIC *mg;

#ifdef AvPAD_NAMELIST
        assert(!(SvTYPE(sv) == SVt_PVAV && AvPAD_NAMELIST(sv)));
#endif

        for (mg = SvMAGIC (sv); mg; mg = mg->mg_moremagic) {
            if (mg->mg_type == type && mg->mg_virtual == vtbl)
                return mg;
        }
    }

    return NULL;
}

#endif
#endif

#if !defined(sv_unmagicext)
#if { NEED sv_unmagicext }

int
sv_unmagicext(pTHX_ SV *const sv, const int type, MGVTBL *vtbl)
{
    MAGIC* mg;
    MAGIC** mgp;

    if (SvTYPE(sv) < SVt_PVMG || !SvMAGIC(sv))
	return 0;
    mgp = &(SvMAGIC(sv));
    for (mg = *mgp; mg; mg = *mgp) {
	const MGVTBL* const virt = mg->mg_virtual;
	if (mg->mg_type == type && virt == vtbl) {
	    *mgp = mg->mg_moremagic;
	    if (virt && virt->svt_free)
		virt->svt_free(aTHX_ sv, mg);
	    if (mg->mg_ptr && mg->mg_type != PERL_MAGIC_regex_global) {
		if (mg->mg_len > 0)
		    Safefree(mg->mg_ptr);
		else if (mg->mg_len == HEf_SVKEY) /* Questionable on older perls... */
		    SvREFCNT_dec(MUTABLE_SV(mg->mg_ptr));
		else if (mg->mg_type == PERL_MAGIC_utf8)
		    Safefree(mg->mg_ptr);
            }
	    if (mg->mg_flags & MGf_REFCOUNTED)
		SvREFCNT_dec(mg->mg_obj);
	    Safefree(mg);
	}
	else
	    mgp = &mg->mg_moremagic;
    }
    if (SvMAGIC(sv)) {
	if (SvMAGICAL(sv))	/* if we're under save_magic, wait for restore_magic; */
	    mg_magical(sv);	/*    else fix the flags now */
    }
    else {
	SvMAGICAL_off(sv);
	SvFLAGS(sv) |= (SvFLAGS(sv) & (SVp_IOK|SVp_NOK|SVp_POK)) >> PRIVSHIFT;
    }
    return 0;
}

#endif
#endif

=xsinit

#define NEED_mg_findext
#define NEED_sv_unmagicext

#ifndef STATIC
#define STATIC static
#endif

STATIC MGVTBL null_mg_vtbl = {
    NULL, /* get */
    NULL, /* set */
    NULL, /* len */
    NULL, /* clear */
    NULL, /* free */
#if MGf_COPY
    NULL, /* copy */
#endif /* MGf_COPY */
#if MGf_DUP
    NULL, /* dup */
#endif /* MGf_DUP */
#if MGf_LOCAL
    NULL, /* local */
#endif /* MGf_LOCAL */
};

STATIC MGVTBL other_mg_vtbl = {
    NULL, /* get */
    NULL, /* set */
    NULL, /* len */
    NULL, /* clear */
    NULL, /* free */
#if MGf_COPY
    NULL, /* copy */
#endif /* MGf_COPY */
#if MGf_DUP
    NULL, /* dup */
#endif /* MGf_DUP */
#if MGf_LOCAL
    NULL, /* local */
#endif /* MGf_LOCAL */
};

=xsubs

SV *
new_with_other_mg(package, ...)
    SV *package
  PREINIT:
    HV *self;
    HV *stash;
    SV *self_ref;
    const char *data = "hello\0";
    MAGIC *mg;
  CODE:
    self = newHV();
    stash = gv_stashpv(SvPV_nolen(package), 0);

    self_ref = newRV_noinc((SV*)self);

    sv_magic((SV*)self, NULL, PERL_MAGIC_ext, data, strlen(data));
    mg = mg_find((SV*)self, PERL_MAGIC_ext);
    if (mg)
      mg->mg_virtual = &other_mg_vtbl;
    else
      croak("No mg!");

    RETVAL = sv_bless(self_ref, stash);
  OUTPUT:
    RETVAL

SV *
new_with_mg(package, ...)
    SV *package
  PREINIT:
    HV *self;
    HV *stash;
    SV *self_ref;
    const char *data = "hello\0";
    MAGIC *mg;
  CODE:
    self = newHV();
    stash = gv_stashpv(SvPV_nolen(package), 0);

    self_ref = newRV_noinc((SV*)self);

    sv_magic((SV*)self, NULL, PERL_MAGIC_ext, data, strlen(data));
    mg = mg_find((SV*)self, PERL_MAGIC_ext);
    if (mg)
      mg->mg_virtual = &null_mg_vtbl;
    else
      croak("No mg!");

    RETVAL = sv_bless(self_ref, stash);
  OUTPUT:
    RETVAL

void
remove_null_magic(self)
    SV *self
  PREINIT:
    HV *obj;
  PPCODE:
    obj = (HV*) SvRV(self);

    sv_unmagicext((SV*)obj, PERL_MAGIC_ext, &null_mg_vtbl);

void
remove_other_magic(self)
    SV *self
  PREINIT:
    HV *obj;
  PPCODE:
    obj = (HV*) SvRV(self);

    sv_unmagicext((SV*)obj, PERL_MAGIC_ext, &other_mg_vtbl);

void
as_string(self)
    SV *self
  PREINIT:
    HV *obj;
    MAGIC *mg;
  PPCODE:
    obj = (HV*) SvRV(self);

    if ((mg = mg_findext((SV*)obj, PERL_MAGIC_ext, &null_mg_vtbl))) {
        XPUSHs(sv_2mortal(newSVpv(mg->mg_ptr, strlen(mg->mg_ptr))));
    } else {
        XPUSHs(sv_2mortal(newSVpvs("Sorry, your princess is in another castle.")));
    }

void
sv_catpv_mg(sv, string)
        SV *sv;
        char *string;
        CODE:
                sv_catpv_mg(sv, string);

void
sv_catpvn_mg(sv, sv2)
        SV *sv;
        SV *sv2;
        PREINIT:
                char *str;
                STRLEN len;
        CODE:
                str = SvPV(sv2, len);
                sv_catpvn_mg(sv, str, len);

void
sv_catsv_mg(sv, sv2)
        SV *sv;
        SV *sv2;
        CODE:
                sv_catsv_mg(sv, sv2);

void
sv_setiv_mg(sv, iv)
        SV *sv;
        IV iv;
        CODE:
                sv_setiv_mg(sv, iv);

void
sv_setnv_mg(sv, nv)
        SV *sv;
        NV nv;
        CODE:
                sv_setnv_mg(sv, nv);

void
sv_setpv_mg(sv, pv)
        SV *sv;
        char *pv;
        CODE:
                sv_setpv_mg(sv, pv);

void
sv_setpvn_mg(sv, sv2)
        SV *sv;
        SV *sv2;
        PREINIT:
                char *str;
                STRLEN len;
        CODE:
                str = SvPV(sv2, len);
                sv_setpvn_mg(sv, str, len);

void
sv_setsv_mg(sv, sv2)
        SV *sv;
        SV *sv2;
        CODE:
                sv_setsv_mg(sv, sv2);

void
sv_setuv_mg(sv, uv)
        SV *sv;
        UV uv;
        CODE:
                sv_setuv_mg(sv, uv);

void
sv_usepvn_mg(sv, sv2)
        SV *sv;
        SV *sv2;
        PREINIT:
                char *str, *copy;
                STRLEN len;
        CODE:
                str = SvPV(sv2, len);
                New(42, copy, len+1, char);
                Copy(str, copy, len+1, char);
                sv_usepvn_mg(sv, copy, len);

int
SvVSTRING_mg(sv)
        SV *sv;
        CODE:
                RETVAL = SvVSTRING_mg(sv) != NULL;
        OUTPUT:
                RETVAL

int
sv_magic_portable(sv)
        SV *sv
        PREINIT:
                MAGIC *mg;
                const char *foo = "foo";
        CODE:
#if { VERSION >= 5.004 }
                sv_magic_portable(sv, 0, '~', foo, 0);
                mg = mg_find(sv, '~');
                if (!mg)
                  croak("No mg!");

                RETVAL = mg->mg_ptr == foo;
#else
                sv_magic(sv, 0, '~', (char *) foo, strlen(foo));
                mg = mg_find(sv, '~');
                RETVAL = strEQ(mg->mg_ptr, foo);
#endif
                sv_unmagic(sv, '~');
        OUTPUT:
                RETVAL

=tests plan => 23

# Find proper magic
ok(my $obj1 = Devel::PPPort->new_with_mg());
ok(Devel::PPPort::as_string($obj1), 'hello');

# Find with no magic
my $obj = bless {}, 'Fake::Class';
ok(Devel::PPPort::as_string($obj), "Sorry, your princess is in another castle.");

# Find with other magic (not the magic we are looking for)
ok($obj = Devel::PPPort->new_with_other_mg());
ok(Devel::PPPort::as_string($obj), "Sorry, your princess is in another castle.");

# Okay, attempt to remove magic that isn't there
Devel::PPPort::remove_other_magic($obj1);
ok(Devel::PPPort::as_string($obj1), 'hello');

# Remove magic that IS there
Devel::PPPort::remove_null_magic($obj1);
ok(Devel::PPPort::as_string($obj1), "Sorry, your princess is in another castle.");

# Removing when no magic present
Devel::PPPort::remove_null_magic($obj1);
ok(Devel::PPPort::as_string($obj1), "Sorry, your princess is in another castle.");

use Tie::Hash;
my %h;
tie %h, 'Tie::StdHash';
$h{foo} = 'foo';
$h{bar} = '';

&Devel::PPPort::sv_catpv_mg($h{foo}, 'bar');
ok($h{foo}, 'foobar');

&Devel::PPPort::sv_catpvn_mg($h{bar}, 'baz');
ok($h{bar}, 'baz');

&Devel::PPPort::sv_catsv_mg($h{foo}, '42');
ok($h{foo}, 'foobar42');

&Devel::PPPort::sv_setiv_mg($h{bar}, 42);
ok($h{bar}, 42);

&Devel::PPPort::sv_setnv_mg($h{PI}, 3.14159);
ok(abs($h{PI} - 3.14159) < 0.01);

&Devel::PPPort::sv_setpv_mg($h{mhx}, 'mhx');
ok($h{mhx}, 'mhx');

&Devel::PPPort::sv_setpvn_mg($h{mhx}, 'Marcus');
ok($h{mhx}, 'Marcus');

&Devel::PPPort::sv_setsv_mg($h{sv}, 'SV');
ok($h{sv}, 'SV');

&Devel::PPPort::sv_setuv_mg($h{sv}, 4711);
ok($h{sv}, 4711);

&Devel::PPPort::sv_usepvn_mg($h{sv}, 'Perl');
ok($h{sv}, 'Perl');

# v1 is treated as a bareword in older perls...
my $ver = do { local $SIG{'__WARN__'} = sub {}; eval qq[v1.2.0] };
ok($] < 5.009 || $@ eq '');
ok($] < 5.009 || Devel::PPPort::SvVSTRING_mg($ver));
ok(!Devel::PPPort::SvVSTRING_mg(4711));

my $foo = 'bar';
ok(Devel::PPPort::sv_magic_portable($foo));
ok($foo eq 'bar');