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

/* pre-5.10 perls always succeed, with 5.10, we have to check first apparently */
#ifndef GvNAME_HEK
# define GvNAME_HEK(sv) 1
#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)),                        \
                  GvNAME_HEK (sv) ? GvNAMELEN (sv) : 11,        \
                  GvNAME_HEK (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:	1.17
Committed:	Wed Jul 1 08:25:04 2009 UTC (17 years, 2 months ago) by root
Branch:	MAIN
CVS Tags:	rel-1_42
Changes since 1.16:	+7 -2 lines
Log Message:	1.42
#	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	1.17	/* pre-5.10 perls always succeed, with 5.10, we have to check first apparently */
20			#ifndef GvNAME_HEK
21			# define GvNAME_HEK(sv) 1
22			#endif
23
24	root	1.6	#define res_pair(text) \
25	root	1.8	do { \
26	root	1.6	AV *av = newAV (); \
27			av_push (av, newSVpv (text, 0)); \
28	root	1.7	if (rmagical) SvRMAGICAL_on (sv); \
29	root	1.6	av_push (av, sv_rvweaken (newRV_inc (sv))); \
30	root	1.7	if (rmagical) SvRMAGICAL_off (sv); \
31	root	1.6	av_push (about, newRV_noinc ((SV *)av)); \
32	root	1.8	} while (0)
33	root	1.1
34	root	1.11	#define res_text(text) \
35	root	1.8	do { \
36	root	1.6	AV *av = newAV (); \
37	root	1.11	av_push (av, newSVpv (text, 0)); \
38	root	1.6	av_push (about, newRV_noinc ((SV *)av)); \
39	root	1.8	} while (0)
40	root	1.1
41	root	1.11	#define res_gv(sigil) \
42			res_text (form ("in the global %c%s::%.*s", sigil, \
43			HvNAME (GvSTASH (sv)), \
44	root	1.17	GvNAME_HEK (sv) ? GvNAMELEN (sv) : 11, \
45			GvNAME_HEK (sv) ? GvNAME (sv) : "<anonymous>"))
46	root	1.11
47	root	1.1	MODULE = Devel::FindRef PACKAGE = Devel::FindRef
48
49			PROTOTYPES: ENABLE
50
51			void
52	root	1.15	find_ (SV *target_ref)
53	root	1.1	PPCODE:
54			{
55			SV arena, targ;
56	root	1.9	U32 rmagical;
57			int i;
58	root	1.1	AV *about = newAV ();
59			AV *excl = newAV ();
60
61	root	1.15	if (!SvROK (target_ref))
62	root	1.3	croak ("find expects a reference to a perl value");
63	root	1.1
64	root	1.15	targ = SvRV (target_ref);
65	root	1.1
66	root	1.16	if (SvIMMORTAL (targ))
67	root	1.1	{
68	root	1.16	if (targ == &PL_sv_undef)
69			res_text ("the immortal 'undef' value");
70			else if (targ == &PL_sv_yes)
71			res_text ("the immortal 'yes' value");
72			else if (targ == &PL_sv_no)
73			res_text ("the immortal 'no' value");
74			else if (targ == &PL_sv_placeholder)
75			res_text ("the immortal placeholder value");
76			else
77			res_text ("some unknown immortal");
78			}
79			else
80			{
81			for (arena = PL_sv_arenaroot; arena; arena = SvANY (arena))
82			{
83			UV idx = SvREFCNT (arena);
84	root	1.1
85	root	1.16	/* Remember that the zeroth slot is used as the pointer onwards, so don't
86			include it. */
87			while (--idx > 0)
88			{
89			SV *sv = &arena [idx];
90	root	1.2
91	root	1.16	if (SvTYPE (sv) >= SVt_LAST)
92			continue;
93	root	1.2
94	root	1.16	/* temporarily disable RMAGICAL, it can easily interfere with us */
95			if ((rmagical = SvRMAGICAL (sv)))
96			SvRMAGICAL_off (sv);
97	root	1.1
98	root	1.16	if (SvTYPE (sv) >= SVt_PVMG)
99	root	1.10	{
100	root	1.16	if (SvTYPE (sv) == SVt_PVMG && SvPAD_OUR (sv))
101			{
102			/* I have no clue what this is */
103			/* maybe some placeholder for our variables for eval? */
104			/* it doesn't seem to reference anything, so we should be able to ignore it */
105			}
106			else
107	root	1.9	{
108	root	1.16	MAGIC *mg = SvMAGIC (sv);
109	root	1.2
110	root	1.16	while (mg)
111			{
112			if (mg->mg_obj == targ && mg->mg_flags & MGf_REFCOUNTED)
113			res_pair (form ("referenced (in mg_obj) by '%c' type magic attached to", mg->mg_type));
114
115			if ((SV *)mg->mg_ptr == targ)
116			res_pair (form ("%sreferenced (in mg_ptr) by '%c' type magic attached to",
117			mg->mg_len == HEf_SVKEY ? "" : "possibly ",
118			mg->mg_type));
119	root	1.9
120	root	1.16	mg = mg->mg_moremagic;
121			}
122	root	1.9	}
123	root	1.2	}
124	root	1.1
125	root	1.16	if (SvROK (sv))
126			{
127			if (SvRV (sv) == targ && !SvWEAKREF (sv) && sv != target_ref)
128			res_pair ("referenced by");
129			}
130			else
131			switch (SvTYPE (sv))
132	root	1.2	{
133	root	1.16	case SVt_PVAV:
134			if (AvREAL (sv))
135			for (i = AvFILLp (sv) + 1; i--; )
136			if (AvARRAY (sv)[i] == targ)
137			res_pair (form ("in array element %d of", i));
138
139			break;
140
141			case SVt_PVHV:
142			if (hv_iterinit ((HV *)sv))
143			{
144			HE *he;
145
146			while ((he = hv_iternext ((HV *)sv)))
147			if (HeVAL (he) == targ)
148			res_pair (form ("in the member '%.*s' of", HeKLEN (he), HeKEY (he)));
149			}
150	root	1.6
151	root	1.16	break;
152	root	1.7
153	root	1.16	case SVt_PVCV:
154	root	1.6	{
155	root	1.16	int depth = CvDEPTH (sv);
156	root	1.6
157	root	1.16	/* Anonymous subs have a padlist but zero depth */
158			if (CvANON (sv) && !depth && CvPADLIST (sv))
159			depth = 1;
160
161			if (depth)
162	root	1.6	{
163	root	1.16	AV *padlist = CvPADLIST (sv);
164	root	1.6
165	root	1.16	while (depth)
166			{
167			AV pad = (AV )AvARRAY (padlist)[depth];
168
169			av_push (excl, newSVuv (PTR2UV (pad))); /* exclude pads themselves from being found */
170
171			/* The 0th pad slot is @_ */
172			if (AvARRAY (pad)[0] == targ)
173			res_pair ("the argument array for");
174
175			for (i = AvFILLp (pad) + 1; --i; )
176			if (AvARRAY (pad)[i] == targ)
177			{
178			/* Values from constant functions are stored in the pad without any name */
179			SV *name_sv = AvARRAY (AvARRAY (padlist)[0])[i];
180
181			if (name_sv && SvPOK (name_sv))
182			res_pair (form ("in the lexical '%s' in", SvPVX (name_sv)));
183			else
184			res_pair ("in an unnamed lexical in");
185			}
186	root	1.6
187	root	1.16	--depth;
188			}
189	root	1.6	}
190	root	1.7
191	root	1.16	if (CvCONST (sv) && (SV*)CvXSUBANY (sv).any_ptr == targ)
192			res_pair ("the constant value of");
193	root	1.8
194	root	1.16	if (!CvWEAKOUTSIDE (sv) && (SV*)CvOUTSIDE (sv) == targ)
195			res_pair ("the containing scope for");
196	root	1.11
197	root	1.16	if (sv == targ && CvANON (sv))
198			if (CvSTART (sv)
199			&& CvSTART (sv)->op_type == OP_NEXTSTATE
200			&& CopLINE ((COP *)CvSTART (sv)))
201			res_text (form ("the closure created at %s:%d",
202			CopFILE ((COP )CvSTART (sv)) ? CopFILE ((COP )CvSTART (sv)) : "<unknown>",
203			CopLINE ((COP *)CvSTART (sv))));
204			else
205			res_text (form ("the closure created somewhere in file %s (PLEASE REPORT!)",
206			CvFILE (sv) ? CvFILE (sv) : "<unknown>"));
207			}
208	root	1.6
209	root	1.16	break;
210	root	1.6
211	root	1.16	case SVt_PVGV:
212			if (GvGP (sv))
213			{
214			if (GvSV (sv) == (SV *)targ) res_gv ('$');
215			if (GvAV (sv) == (AV *)targ) res_gv ('@');
216			if (GvHV (sv) == (HV *)targ) res_gv ('%');
217			if (GvCV (sv) == (CV *)targ) res_gv ('&');
218			}
219
220			break;
221
222			case SVt_PVLV:
223			if (LvTARG (sv) == targ)
224			{
225			if (LvTYPE (sv) == 'y')
226			{
227			MAGIC *mg = mg_find (sv, PERL_MAGIC_defelem);
228
229			if (mg && mg->mg_obj)
230			res_pair (form ("the target for the lvalue hash element '%.*s',",
231			SvCUR (mg->mg_obj), SvPV_nolen (mg->mg_obj)));
232			else
233			res_pair (form ("the target for the lvalue array element #%d,", LvTARGOFF (sv)));
234			}
235			else
236			res_pair (form ("an lvalue reference target (type '%c', ofs %d, len %d),",
237			LvTYPE (sv), LvTARGOFF (sv), LvTARGLEN (sv)));
238			}
239	root	1.6
240	root	1.16	break;
241			}
242	root	1.1
243	root	1.16	if (rmagical)
244			SvRMAGICAL_on (sv);
245			}
246	root	1.1	}
247
248	root	1.16	/* look at the mortalise stack of the current coroutine */
249			for (i = 0; i <= PL_tmps_ix; ++i)
250			if (PL_tmps_stack [i] == targ)
251			res_text ("a temporary on the stack");
252	root	1.15
253	root	1.16	if (targ == (SV*)PL_main_cv)
254			res_text ("the main body of the program");
255			}
256	root	1.13
257	root	1.1	EXTEND (SP, 2);
258			PUSHs (sv_2mortal (newRV_noinc ((SV *)about)));
259			PUSHs (sv_2mortal (newRV_noinc ((SV *)excl)));
260			}
261
262	root	1.14	SV *
263			ptr2ref (UV ptr)
264			CODE:
265			RETVAL = newRV_inc (INT2PTR (SV *, ptr));
266			OUTPUT:
267			RETVAL
268
269			UV
270			ref2ptr (SV *rv)
271			CODE:
272	root	1.16	if (!SvROK (rv))
273			croak ("argument to Devel::FindRef::ref2ptr must be a reference");
274	root	1.14	RETVAL = PTR2UV (SvRV (rv));
275			OUTPUT:
276			RETVAL
277
278			U32
279			_refcnt (SV *rv)
280			CODE:
281	root	1.16	if (!SvROK (rv))
282			croak ("argument to Devel::FindRef::_refcnt must be a reference");
283	root	1.14	RETVAL = SvREFCNT (SvRV (rv));
284			OUTPUT:
285			RETVAL