Devel-FindRef/FindRef.xs

#include "EXTERN.h"
#include "perl.h"
#include "XSUB.h"

#define PERL_VERSION_ATLEAST(a,b,c)                             \
  (PERL_REVISION > (a)                                          \
   || (PERL_REVISION == (a)                                     \
       && (PERL_VERSION > (b)                                   \
           || (PERL_VERSION == (b) && PERLSUBVERSION >= (c)))))

#if !PERL_VERSION_ATLEAST (5,8,9)
# define SVt_LAST 16
#endif

#if !PERL_VERSION_ATLEAST (5,10,0)
# define SvPAD_OUR(dummy) 0
#endif

#define res_pair(text)                                          \
  do {                                                          \
    AV *av = newAV ();                                          \
    av_push (av, newSVpv (text, 0));                            \
    if (rmagical) SvRMAGICAL_on (sv);                           \
    av_push (av, sv_rvweaken (newRV_inc (sv)));                 \
    if (rmagical) SvRMAGICAL_off (sv);                          \
    av_push (about, newRV_noinc ((SV *)av));                    \
  } while (0)

#define res_text(text)                                          \
  do {                                                          \
    AV *av = newAV ();                                          \
    av_push (av, newSVpv (text, 0));                            \
    av_push (about, newRV_noinc ((SV *)av));                    \
  } while (0)

#define res_gv(sigil)                                           \
  res_text (form ("in the global %c%s::%.*s", sigil,            \
                  HvNAME (GvSTASH (sv)),                        \
                  GvNAMELEN (sv),                               \
                  GvNAME (sv) ? GvNAME (sv) : "<anonymous>"))

MODULE = Devel::FindRef         PACKAGE = Devel::FindRef                

PROTOTYPES: ENABLE

void
find_ (SV *target_ref)
        PPCODE:
{
        SV *arena, *targ;
        U32 rmagical;
        int i;
        AV *about = newAV ();
        AV *excl  = newAV ();

        if (!SvROK (target_ref))
          croak ("find expects a reference to a perl value");

        targ = SvRV (target_ref);

        if (SvIMMORTAL (targ))
          {
            if (targ == &PL_sv_undef)
              res_text ("the immortal 'undef' value");
            else if (targ == &PL_sv_yes)
              res_text ("the immortal 'yes' value");
            else if (targ == &PL_sv_no)
              res_text ("the immortal 'no' value");
            else if (targ == &PL_sv_placeholder)
              res_text ("the immortal placeholder value");
            else
              res_text ("some unknown immortal");
          }
        else
          {
            for (arena = PL_sv_arenaroot; arena; arena = SvANY (arena))
              {
                UV idx = SvREFCNT (arena);

                /* Remember that the zeroth slot is used as the pointer onwards, so don't
                   include it. */
                while (--idx > 0)
                  {
                    SV *sv = &arena [idx];

                    if (SvTYPE (sv) >= SVt_LAST)
                      continue;

                    /* temporarily disable RMAGICAL, it can easily interfere with us */
                    if ((rmagical = SvRMAGICAL (sv)))
                      SvRMAGICAL_off (sv);

                    if (SvTYPE (sv) >= SVt_PVMG)
                      {
                        if (SvTYPE (sv) == SVt_PVMG && SvPAD_OUR (sv))
                          {
                            /* I have no clue what this is */
                            /* maybe some placeholder for our variables for eval? */
                            /* it doesn't seem to reference anything, so we should be able to ignore it */
                          }
                        else
                          {
                            MAGIC *mg = SvMAGIC (sv);

                            while (mg)
                              {
                                if (mg->mg_obj == targ && mg->mg_flags & MGf_REFCOUNTED)
                                  res_pair (form ("referenced (in mg_obj) by '%c' type magic attached to", mg->mg_type));

                                if ((SV *)mg->mg_ptr == targ)
                                  res_pair (form ("%sreferenced (in mg_ptr) by '%c' type magic attached to",
                                                  mg->mg_len == HEf_SVKEY ? "" : "possibly ",
                                                  mg->mg_type));

                                mg = mg->mg_moremagic;
                              }
                          }
                      }

                    if (SvROK (sv))
                      {
                        if (SvRV (sv) == targ && !SvWEAKREF (sv) && sv != target_ref)
                          res_pair ("referenced by");
                      }
                    else
                      switch (SvTYPE (sv))
                        {
                          case SVt_PVAV:
                            if (AvREAL (sv))
                              for (i = AvFILLp (sv) + 1; i--; )
                                if (AvARRAY (sv)[i] == targ)
                                  res_pair (form ("in array element %d of", i));

                            break;

                          case SVt_PVHV:
                            if (hv_iterinit ((HV *)sv))
                              {
                                HE *he;

                                while ((he = hv_iternext ((HV *)sv)))
                                  if (HeVAL (he) == targ)
                                    res_pair (form ("in the member '%.*s' of", HeKLEN (he), HeKEY (he)));
                              }

                            break;

                          case SVt_PVCV:
                            {
                              int depth = CvDEPTH (sv);

                              /* Anonymous subs have a padlist but zero depth */
                              if (CvANON (sv) && !depth && CvPADLIST (sv))
                                depth = 1;

                              if (depth)
                                {
                                  AV *padlist = CvPADLIST (sv);

                                  while (depth)
                                    {
                                      AV *pad = (AV *)AvARRAY (padlist)[depth];

                                      av_push (excl, newSVuv (PTR2UV (pad))); /* exclude pads themselves from being found */

                                      /* The 0th pad slot is @_ */
                                      if (AvARRAY (pad)[0] == targ)
                                        res_pair ("the argument array for");

                                      for (i = AvFILLp (pad) + 1; --i; )
                                        if (AvARRAY (pad)[i] == targ)
                                          {
                                            /* Values from constant functions are stored in the pad without any name */
                                            SV *name_sv = AvARRAY (AvARRAY (padlist)[0])[i];

                                            if (name_sv && SvPOK (name_sv))
                                              res_pair (form ("in the lexical '%s' in", SvPVX (name_sv)));
                                            else
                                              res_pair ("in an unnamed lexical in");
                                          }

                                      --depth;
                                    }
                                }

                              if (CvCONST (sv) && (SV*)CvXSUBANY (sv).any_ptr == targ)
                                res_pair ("the constant value of");

                              if (!CvWEAKOUTSIDE (sv) && (SV*)CvOUTSIDE (sv) == targ)
                                res_pair ("the containing scope for");

                              if (sv == targ && CvANON (sv))
                                if (CvSTART (sv)
                                    && CvSTART (sv)->op_type == OP_NEXTSTATE
                                    && CopLINE ((COP *)CvSTART (sv)))
                                  res_text (form ("the closure created at %s:%d",
                                                  CopFILE ((COP *)CvSTART (sv)) ? CopFILE ((COP *)CvSTART (sv)) : "<unknown>",
                                                  CopLINE ((COP *)CvSTART (sv))));
                                else
                                  res_text (form ("the closure created somewhere in file %s (PLEASE REPORT!)",
                                                  CvFILE (sv) ? CvFILE (sv) : "<unknown>"));
                            }

                            break;

                          case SVt_PVGV:
                            if (GvGP (sv))
                              {
                                if (GvSV (sv) == (SV *)targ) res_gv ('$');
                                if (GvAV (sv) == (AV *)targ) res_gv ('@');
                                if (GvHV (sv) == (HV *)targ) res_gv ('%');
                                if (GvCV (sv) == (CV *)targ) res_gv ('&');
                              }

                            break;

                          case SVt_PVLV:
                            if (LvTARG (sv) == targ)
                              {
                                if (LvTYPE (sv) == 'y')
                                  {
                                    MAGIC *mg = mg_find (sv, PERL_MAGIC_defelem);

                                    if (mg && mg->mg_obj)
                                      res_pair (form ("the target for the lvalue hash element '%.*s',",
                                                      SvCUR (mg->mg_obj), SvPV_nolen (mg->mg_obj)));
                                    else
                                      res_pair (form ("the target for the lvalue array element #%d,", LvTARGOFF (sv)));
                                  }
                                else
                                  res_pair (form ("an lvalue reference target (type '%c', ofs %d, len %d),",
                                                  LvTYPE (sv), LvTARGOFF (sv), LvTARGLEN (sv)));
                              }

                            break;
                        }

                    if (rmagical)
                      SvRMAGICAL_on (sv);
                  }
              }

            /* look at the mortalise stack of the current coroutine */
            for (i = 0; i <= PL_tmps_ix; ++i)
              if (PL_tmps_stack [i] == targ)
                res_text ("a temporary on the stack");

            if (targ == (SV*)PL_main_cv)
              res_text ("the main body of the program");
          }

        EXTEND (SP, 2);
        PUSHs (sv_2mortal (newRV_noinc ((SV *)about)));
        PUSHs (sv_2mortal (newRV_noinc ((SV *)excl)));
}

SV *
ptr2ref (UV ptr)
        CODE:
        RETVAL = newRV_inc (INT2PTR (SV *, ptr));
        OUTPUT:
        RETVAL

UV
ref2ptr (SV *rv)
        CODE:
        if (!SvROK (rv))
          croak ("argument to Devel::FindRef::ref2ptr must be a reference");
        RETVAL = PTR2UV (SvRV (rv));
        OUTPUT:
        RETVAL

U32
_refcnt (SV *rv)
        CODE:
        if (!SvROK (rv))
          croak ("argument to Devel::FindRef::_refcnt must be a reference");
        RETVAL = SvREFCNT (SvRV (rv));
        OUTPUT:
        RETVAL
Revision:	1.16
Committed:	Fri Jun 26 14:47:03 2009 UTC (14 years, 10 months ago) by root
Branch:	MAIN
CVS Tags:	rel-1_41
Changes since 1.15:	+163 -121 lines
Log Message:	* empty log message *
#	User	Rev	Content
1	root	1.1	#include "EXTERN.h"
2			#include "perl.h"
3			#include "XSUB.h"
4
5	root	1.4	#define PERL_VERSION_ATLEAST(a,b,c) \
6			(PERL_REVISION > (a) \
7			\|\| (PERL_REVISION == (a) \
8			&& (PERL_VERSION > (b) \
9			\|\| (PERL_VERSION == (b) && PERLSUBVERSION >= (c)))))
10
11			#if !PERL_VERSION_ATLEAST (5,8,9)
12			# define SVt_LAST 16
13			#endif
14
15	root	1.9	#if !PERL_VERSION_ATLEAST (5,10,0)
16			# define SvPAD_OUR(dummy) 0
17			#endif
18
19	root	1.6	#define res_pair(text) \
20	root	1.8	do { \
21	root	1.6	AV *av = newAV (); \
22			av_push (av, newSVpv (text, 0)); \
23	root	1.7	if (rmagical) SvRMAGICAL_on (sv); \
24	root	1.6	av_push (av, sv_rvweaken (newRV_inc (sv))); \
25	root	1.7	if (rmagical) SvRMAGICAL_off (sv); \
26	root	1.6	av_push (about, newRV_noinc ((SV *)av)); \
27	root	1.8	} while (0)
28	root	1.1
29	root	1.11	#define res_text(text) \
30	root	1.8	do { \
31	root	1.6	AV *av = newAV (); \
32	root	1.11	av_push (av, newSVpv (text, 0)); \
33	root	1.6	av_push (about, newRV_noinc ((SV *)av)); \
34	root	1.8	} while (0)
35	root	1.1
36	root	1.11	#define res_gv(sigil) \
37			res_text (form ("in the global %c%s::%.*s", sigil, \
38			HvNAME (GvSTASH (sv)), \
39			GvNAMELEN (sv), \
40			GvNAME (sv) ? GvNAME (sv) : "<anonymous>"))
41
42	root	1.1	MODULE = Devel::FindRef PACKAGE = Devel::FindRef
43
44			PROTOTYPES: ENABLE
45
46			void
47	root	1.15	find_ (SV *target_ref)
48	root	1.1	PPCODE:
49			{
50			SV arena, targ;
51	root	1.9	U32 rmagical;
52			int i;
53	root	1.1	AV *about = newAV ();
54			AV *excl = newAV ();
55
56	root	1.15	if (!SvROK (target_ref))
57	root	1.3	croak ("find expects a reference to a perl value");
58	root	1.1
59	root	1.15	targ = SvRV (target_ref);
60	root	1.1
61	root	1.16	if (SvIMMORTAL (targ))
62	root	1.1	{
63	root	1.16	if (targ == &PL_sv_undef)
64			res_text ("the immortal 'undef' value");
65			else if (targ == &PL_sv_yes)
66			res_text ("the immortal 'yes' value");
67			else if (targ == &PL_sv_no)
68			res_text ("the immortal 'no' value");
69			else if (targ == &PL_sv_placeholder)
70			res_text ("the immortal placeholder value");
71			else
72			res_text ("some unknown immortal");
73			}
74			else
75			{
76			for (arena = PL_sv_arenaroot; arena; arena = SvANY (arena))
77			{
78			UV idx = SvREFCNT (arena);
79	root	1.1
80	root	1.16	/* Remember that the zeroth slot is used as the pointer onwards, so don't
81			include it. */
82			while (--idx > 0)
83			{
84			SV *sv = &arena [idx];
85	root	1.2
86	root	1.16	if (SvTYPE (sv) >= SVt_LAST)
87			continue;
88	root	1.2
89	root	1.16	/* temporarily disable RMAGICAL, it can easily interfere with us */
90			if ((rmagical = SvRMAGICAL (sv)))
91			SvRMAGICAL_off (sv);
92	root	1.1
93	root	1.16	if (SvTYPE (sv) >= SVt_PVMG)
94	root	1.10	{
95	root	1.16	if (SvTYPE (sv) == SVt_PVMG && SvPAD_OUR (sv))
96			{
97			/* I have no clue what this is */
98			/* maybe some placeholder for our variables for eval? */
99			/* it doesn't seem to reference anything, so we should be able to ignore it */
100			}
101			else
102	root	1.9	{
103	root	1.16	MAGIC *mg = SvMAGIC (sv);
104	root	1.2
105	root	1.16	while (mg)
106			{
107			if (mg->mg_obj == targ && mg->mg_flags & MGf_REFCOUNTED)
108			res_pair (form ("referenced (in mg_obj) by '%c' type magic attached to", mg->mg_type));
109
110			if ((SV *)mg->mg_ptr == targ)
111			res_pair (form ("%sreferenced (in mg_ptr) by '%c' type magic attached to",
112			mg->mg_len == HEf_SVKEY ? "" : "possibly ",
113			mg->mg_type));
114	root	1.9
115	root	1.16	mg = mg->mg_moremagic;
116			}
117	root	1.9	}
118	root	1.2	}
119	root	1.1
120	root	1.16	if (SvROK (sv))
121			{
122			if (SvRV (sv) == targ && !SvWEAKREF (sv) && sv != target_ref)
123			res_pair ("referenced by");
124			}
125			else
126			switch (SvTYPE (sv))
127	root	1.2	{
128	root	1.16	case SVt_PVAV:
129			if (AvREAL (sv))
130			for (i = AvFILLp (sv) + 1; i--; )
131			if (AvARRAY (sv)[i] == targ)
132			res_pair (form ("in array element %d of", i));
133
134			break;
135
136			case SVt_PVHV:
137			if (hv_iterinit ((HV *)sv))
138			{
139			HE *he;
140
141			while ((he = hv_iternext ((HV *)sv)))
142			if (HeVAL (he) == targ)
143			res_pair (form ("in the member '%.*s' of", HeKLEN (he), HeKEY (he)));
144			}
145	root	1.6
146	root	1.16	break;
147	root	1.7
148	root	1.16	case SVt_PVCV:
149	root	1.6	{
150	root	1.16	int depth = CvDEPTH (sv);
151	root	1.6
152	root	1.16	/* Anonymous subs have a padlist but zero depth */
153			if (CvANON (sv) && !depth && CvPADLIST (sv))
154			depth = 1;
155
156			if (depth)
157	root	1.6	{
158	root	1.16	AV *padlist = CvPADLIST (sv);
159	root	1.6
160	root	1.16	while (depth)
161			{
162			AV pad = (AV )AvARRAY (padlist)[depth];
163
164			av_push (excl, newSVuv (PTR2UV (pad))); /* exclude pads themselves from being found */
165
166			/* The 0th pad slot is @_ */
167			if (AvARRAY (pad)[0] == targ)
168			res_pair ("the argument array for");
169
170			for (i = AvFILLp (pad) + 1; --i; )
171			if (AvARRAY (pad)[i] == targ)
172			{
173			/* Values from constant functions are stored in the pad without any name */
174			SV *name_sv = AvARRAY (AvARRAY (padlist)[0])[i];
175
176			if (name_sv && SvPOK (name_sv))
177			res_pair (form ("in the lexical '%s' in", SvPVX (name_sv)));
178			else
179			res_pair ("in an unnamed lexical in");
180			}
181	root	1.6
182	root	1.16	--depth;
183			}
184	root	1.6	}
185	root	1.7
186	root	1.16	if (CvCONST (sv) && (SV*)CvXSUBANY (sv).any_ptr == targ)
187			res_pair ("the constant value of");
188	root	1.8
189	root	1.16	if (!CvWEAKOUTSIDE (sv) && (SV*)CvOUTSIDE (sv) == targ)
190			res_pair ("the containing scope for");
191	root	1.11
192	root	1.16	if (sv == targ && CvANON (sv))
193			if (CvSTART (sv)
194			&& CvSTART (sv)->op_type == OP_NEXTSTATE
195			&& CopLINE ((COP *)CvSTART (sv)))
196			res_text (form ("the closure created at %s:%d",
197			CopFILE ((COP )CvSTART (sv)) ? CopFILE ((COP )CvSTART (sv)) : "<unknown>",
198			CopLINE ((COP *)CvSTART (sv))));
199			else
200			res_text (form ("the closure created somewhere in file %s (PLEASE REPORT!)",
201			CvFILE (sv) ? CvFILE (sv) : "<unknown>"));
202			}
203	root	1.6
204	root	1.16	break;
205	root	1.6
206	root	1.16	case SVt_PVGV:
207			if (GvGP (sv))
208			{
209			if (GvSV (sv) == (SV *)targ) res_gv ('$');
210			if (GvAV (sv) == (AV *)targ) res_gv ('@');
211			if (GvHV (sv) == (HV *)targ) res_gv ('%');
212			if (GvCV (sv) == (CV *)targ) res_gv ('&');
213			}
214
215			break;
216
217			case SVt_PVLV:
218			if (LvTARG (sv) == targ)
219			{
220			if (LvTYPE (sv) == 'y')
221			{
222			MAGIC *mg = mg_find (sv, PERL_MAGIC_defelem);
223
224			if (mg && mg->mg_obj)
225			res_pair (form ("the target for the lvalue hash element '%.*s',",
226			SvCUR (mg->mg_obj), SvPV_nolen (mg->mg_obj)));
227			else
228			res_pair (form ("the target for the lvalue array element #%d,", LvTARGOFF (sv)));
229			}
230			else
231			res_pair (form ("an lvalue reference target (type '%c', ofs %d, len %d),",
232			LvTYPE (sv), LvTARGOFF (sv), LvTARGLEN (sv)));
233			}
234	root	1.6
235	root	1.16	break;
236			}
237	root	1.1
238	root	1.16	if (rmagical)
239			SvRMAGICAL_on (sv);
240			}
241	root	1.1	}
242
243	root	1.16	/* look at the mortalise stack of the current coroutine */
244			for (i = 0; i <= PL_tmps_ix; ++i)
245			if (PL_tmps_stack [i] == targ)
246			res_text ("a temporary on the stack");
247	root	1.15
248	root	1.16	if (targ == (SV*)PL_main_cv)
249			res_text ("the main body of the program");
250			}
251	root	1.13
252	root	1.1	EXTEND (SP, 2);
253			PUSHs (sv_2mortal (newRV_noinc ((SV *)about)));
254			PUSHs (sv_2mortal (newRV_noinc ((SV *)excl)));
255			}
256
257	root	1.14	SV *
258			ptr2ref (UV ptr)
259			CODE:
260			RETVAL = newRV_inc (INT2PTR (SV *, ptr));
261			OUTPUT:
262			RETVAL
263
264			UV
265			ref2ptr (SV *rv)
266			CODE:
267	root	1.16	if (!SvROK (rv))
268			croak ("argument to Devel::FindRef::ref2ptr must be a reference");
269	root	1.14	RETVAL = PTR2UV (SvRV (rv));
270			OUTPUT:
271			RETVAL
272
273			U32
274			_refcnt (SV *rv)
275			CODE:
276	root	1.16	if (!SvROK (rv))
277			croak ("argument to Devel::FindRef::_refcnt must be a reference");
278	root	1.14	RETVAL = SvREFCNT (SvRV (rv));
279			OUTPUT:
280			RETVAL