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/cvs/Devel-FindRef/FindRef.xs
Revision: 1.24
Committed: Fri May 16 07:43:52 2014 UTC (10 years ago) by root
Branch: MAIN
CVS Tags: rel-1_43
Changes since 1.23: +8 -7 lines
Log Message:
1.43

File Contents

# Content
1 #include "EXTERN.h"
2 #include "perl.h"
3 #include "XSUB.h"
4
5 #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 #if !PERL_VERSION_ATLEAST (5,10,0)
16 # define SvPAD_OUR(dummy) 0
17 #endif
18
19 /* 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 #ifndef PadARRAY
25 # define PadARRAY(pad) AvARRAY (pad)
26 # define PadlistARRAY(pl) ((PAD **)AvARRAY (pl))
27 #endif
28
29
30 #define res_pair(text) \
31 do { \
32 AV *av = newAV (); \
33 av_push (av, newSVpv (text, 0)); \
34 if (rmagical) SvRMAGICAL_on (sv); \
35 av_push (av, sv_rvweaken (newRV_inc (sv))); \
36 if (rmagical) SvRMAGICAL_off (sv); \
37 av_push (about, newRV_noinc ((SV *)av)); \
38 } while (0)
39
40 #define res_text(text) \
41 do { \
42 AV *av = newAV (); \
43 av_push (av, newSVpv (text, 0)); \
44 av_push (about, newRV_noinc ((SV *)av)); \
45 } while (0)
46
47 #define res_gv(sigil) \
48 res_text (form ("the global %c%s::%.*s", sigil, \
49 HvNAME (GvSTASH (sv)), \
50 GvNAME_HEK (sv) ? GvNAMELEN (sv) : 11, \
51 GvNAME_HEK (sv) ? GvNAME (sv) : "<anonymous>"))
52
53 MODULE = Devel::FindRef PACKAGE = Devel::FindRef
54
55 PROTOTYPES: ENABLE
56
57 void
58 find_ (SV *target_ref)
59 PPCODE:
60 {
61 SV *arena, *targ;
62 U32 rmagical;
63 int i;
64 AV *about = newAV ();
65 AV *excl = newAV ();
66
67 if (!SvROK (target_ref))
68 croak ("find expects a reference to a perl value");
69
70 targ = SvRV (target_ref);
71
72 if (SvIMMORTAL (targ))
73 {
74 if (targ == &PL_sv_undef)
75 res_text ("the immortal 'undef' value");
76 else if (targ == &PL_sv_yes)
77 res_text ("the immortal 'yes' value");
78 else if (targ == &PL_sv_no)
79 res_text ("the immortal 'no' value");
80 else if (targ == &PL_sv_placeholder)
81 res_text ("the immortal placeholder value");
82 else
83 res_text ("some unknown immortal");
84 }
85 else
86 {
87 for (arena = PL_sv_arenaroot; arena; arena = SvANY (arena))
88 {
89 UV idx = SvREFCNT (arena);
90
91 /* Remember that the zeroth slot is used as the pointer onwards, so don't
92 include it. */
93 while (--idx > 0)
94 {
95 SV *sv = &arena [idx];
96
97 if (SvTYPE (sv) >= SVt_LAST)
98 continue;
99
100 /* temporarily disable RMAGICAL, it can easily interfere with us */
101 if ((rmagical = SvRMAGICAL (sv)))
102 SvRMAGICAL_off (sv);
103
104 if (SvTYPE (sv) >= SVt_PVMG)
105 {
106 if (SvTYPE (sv) == SVt_PVMG && SvPAD_OUR (sv))
107 {
108 /* I have no clue what this is */
109 /* maybe some placeholder for our variables for eval? */
110 /* it doesn't seem to reference anything, so we should be able to ignore it */
111 }
112 else
113 {
114 MAGIC *mg = SvMAGIC (sv);
115
116 while (mg)
117 {
118 if (mg->mg_obj == targ && mg->mg_flags & MGf_REFCOUNTED)
119 res_pair (form ("referenced (in mg_obj) by '%c' type magic attached to", mg->mg_type));
120
121 if ((SV *)mg->mg_ptr == targ)
122 res_pair (form ("%sreferenced (in mg_ptr) by '%c' type magic attached to",
123 mg->mg_len == HEf_SVKEY ? "" : "possibly ",
124 mg->mg_type));
125
126 mg = mg->mg_moremagic;
127 }
128 }
129 }
130
131 if (SvROK (sv))
132 {
133 if (SvRV (sv) == targ && !SvWEAKREF (sv) && sv != target_ref)
134 res_pair ("referenced by");
135 }
136 else
137 switch (SvTYPE (sv))
138 {
139 case SVt_PVAV:
140 if (AvREAL (sv))
141 for (i = AvFILLp (sv) + 1; i--; )
142 if (AvARRAY (sv)[i] == targ)
143 res_pair (form ("the array element %d of", i));
144
145 break;
146
147 case SVt_PVHV:
148 if (hv_iterinit ((HV *)sv))
149 {
150 HE *he;
151
152 while ((he = hv_iternext ((HV *)sv)))
153 if (HeVAL (he) == targ)
154 res_pair (form ("the hash member '%.*s' of", HeKLEN (he), HeKEY (he)));
155 }
156
157 break;
158
159 case SVt_PVCV:
160 {
161 PADLIST *padlist = CvPADLIST (sv);
162
163 if (padlist)
164 {
165 int depth = CvDEPTH (sv);
166
167 /* Anonymous subs have a padlist but zero depth */
168 /* some hacks switch CvANON off, so we just blindly assume a minimum of 1 */
169 if (!depth)
170 depth = 1;
171
172 while (depth)
173 {
174 PAD *pad = PadlistARRAY (padlist)[depth];
175
176 av_push (excl, newSVuv (PTR2UV (pad))); /* exclude pads themselves from being found */
177
178 /* The 0th pad slot is @_ */
179 if (PadARRAY (pad)[0] == targ)
180 res_pair ("the argument array for");
181
182 for (i = AvFILLp (pad) + 1; --i; )
183 if (AvARRAY (pad)[i] == targ)
184 {
185 /* Values from constant functions are stored in the pad without any name */
186 SV *name_sv = PadARRAY (PadlistARRAY (padlist)[0])[i];
187
188 if (name_sv && SvPOK (name_sv))
189 res_pair (form ("the lexical '%s' in", SvPVX (name_sv)));
190 else
191 res_pair ("an unnamed lexical in");
192 }
193
194 --depth;
195 }
196 }
197
198 if (CvCONST (sv) && (SV*)CvXSUBANY (sv).any_ptr == targ)
199 res_pair ("the constant value of");
200
201 if (!CvWEAKOUTSIDE (sv) && (SV*)CvOUTSIDE (sv) == targ)
202 res_pair ("the containing scope for");
203
204 if (sv == targ && CvANON (sv))
205 if (CvSTART (sv)
206 && CvSTART (sv)->op_type == OP_NEXTSTATE
207 && CopLINE ((COP *)CvSTART (sv)))
208 res_text (form ("the closure created at %s:%d",
209 CopFILE ((COP *)CvSTART (sv)) ? CopFILE ((COP *)CvSTART (sv)) : "<unknown>",
210 CopLINE ((COP *)CvSTART (sv))));
211 else
212 res_text (form ("the closure created somewhere in file %s (PLEASE REPORT!)",
213 CvFILE (sv) ? CvFILE (sv) : "<unknown>"));
214 }
215
216 break;
217
218 case SVt_PVGV:
219 if (GvGP (sv))
220 {
221 if (GvSV (sv) == (SV *)targ) res_gv ('$');
222 if (GvAV (sv) == (AV *)targ) res_gv ('@');
223 if (GvHV (sv) == (HV *)targ) res_gv ('%');
224 if (GvCV (sv) == (CV *)targ) res_gv ('&');
225 }
226
227 break;
228
229 case SVt_PVLV:
230 if (LvTARG (sv) == targ)
231 {
232 if (LvTYPE (sv) == 'y')
233 {
234 MAGIC *mg = mg_find (sv, PERL_MAGIC_defelem);
235
236 if (mg && mg->mg_obj)
237 res_pair (form ("the target for the lvalue hash element '%.*s',",
238 (int)SvCUR (mg->mg_obj), SvPV_nolen (mg->mg_obj)));
239 else
240 res_pair (form ("the target for the lvalue array element #%d,", LvTARGOFF (sv)));
241 }
242 else
243 res_pair (form ("an lvalue reference target (type '%c', ofs %d, len %d),",
244 LvTYPE (sv), LvTARGOFF (sv), LvTARGLEN (sv)));
245 }
246
247 break;
248 }
249
250 if (rmagical)
251 SvRMAGICAL_on (sv);
252 }
253 }
254
255 /* look at the mortalise stack of the current coroutine */
256 for (i = 0; i <= PL_tmps_ix; ++i)
257 if (PL_tmps_stack [i] == targ)
258 res_text ("a temporary on the stack");
259
260 if (targ == (SV*)PL_main_cv)
261 res_text ("the main body of the program");
262 }
263
264 EXTEND (SP, 2);
265 PUSHs (sv_2mortal (newRV_noinc ((SV *)about)));
266 PUSHs (sv_2mortal (newRV_noinc ((SV *)excl)));
267 }
268
269 SV *
270 ptr2ref (UV ptr)
271 CODE:
272 RETVAL = newRV_inc (INT2PTR (SV *, ptr));
273 OUTPUT:
274 RETVAL
275
276 UV
277 ref2ptr (SV *rv)
278 CODE:
279 if (!SvROK (rv))
280 croak ("argument to Devel::FindRef::ref2ptr must be a reference");
281 RETVAL = PTR2UV (SvRV (rv));
282 OUTPUT:
283 RETVAL
284
285 U32
286 _refcnt (SV *rv)
287 CODE:
288 if (!SvROK (rv))
289 croak ("argument to Devel::FindRef::_refcnt must be a reference");
290 RETVAL = SvREFCNT (SvRV (rv));
291 OUTPUT:
292 RETVAL