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/cvs/Devel-FindRef/FindRef.xs
Revision: 1.27
Committed: Tue Jul 31 22:55:47 2018 UTC (5 years, 11 months ago) by root
Branch: MAIN
CVS Tags: rel-1_46, HEAD
Changes since 1.26: +1 -1 lines
Log Message:
*** empty log message ***

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) && PERL_SUBVERSION >= (c)))))
10
11 #if !PERL_VERSION_ATLEAST (5,8,9)
12 # define SVt_LAST 16
13 #endif
14
15 #ifndef SvPAD_OUR
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 typedef AV PADNAMELIST;
26 typedef SV PADNAME;
27 # define PadnamePV(sv) SvPVX (sv)
28 # define PadnameLEN(sv) SvCUR (sv)
29 # define PadARRAY(pad) AvARRAY (pad)
30 # define PadlistARRAY(pl) ((PAD **)AvARRAY (pl))
31 #endif
32
33 #ifndef PadMAX
34 # define PadMAX(pad) AvFILLp (pad)
35 #endif
36
37 #ifndef padnamelist_fetch
38 # define padnamelist_fetch(a,b) *av_fetch (a, b, FALSE)
39 #endif
40
41 #ifndef PadlistNAMES
42 # define PadlistNAMES(padlist) *PadlistARRAY (padlist)
43 #endif
44
45 #define res_pair(text) \
46 do { \
47 AV *av = newAV (); \
48 av_push (av, newSVpv (text, 0)); \
49 if (rmagical) SvRMAGICAL_on (sv); \
50 av_push (av, sv_rvweaken (newRV_inc (sv))); \
51 if (rmagical) SvRMAGICAL_off (sv); \
52 av_push (about, newRV_noinc ((SV *)av)); \
53 } while (0)
54
55 #define res_text(text) \
56 do { \
57 AV *av = newAV (); \
58 av_push (av, newSVpv (text, 0)); \
59 av_push (about, newRV_noinc ((SV *)av)); \
60 } while (0)
61
62 #define res_gv(sigil) \
63 res_text (form ("the global %c%s::%.*s", sigil, \
64 HvNAME (GvSTASH (sv)), \
65 GvNAME_HEK (sv) ? GvNAMELEN (sv) : 11, \
66 GvNAME_HEK (sv) ? GvNAME (sv) : "<anonymous>"))
67
68 MODULE = Devel::FindRef PACKAGE = Devel::FindRef
69
70 PROTOTYPES: ENABLE
71
72 void
73 find_ (SV *target_ref)
74 PPCODE:
75 {
76 SV *arena, *targ;
77 U32 rmagical;
78 int i;
79 AV *about = newAV ();
80 AV *excl = newAV ();
81
82 if (!SvROK (target_ref))
83 croak ("find expects a reference to a perl value");
84
85 targ = SvRV (target_ref);
86
87 if (SvIMMORTAL (targ))
88 {
89 if (targ == &PL_sv_undef)
90 res_text ("the immortal 'undef' value");
91 else if (targ == &PL_sv_yes)
92 res_text ("the immortal 'yes' value");
93 else if (targ == &PL_sv_no)
94 res_text ("the immortal 'no' value");
95 else if (targ == &PL_sv_placeholder)
96 res_text ("the immortal placeholder value");
97 else
98 res_text ("some unknown immortal");
99 }
100 else
101 {
102 for (arena = PL_sv_arenaroot; arena; arena = SvANY (arena))
103 {
104 UV idx = SvREFCNT (arena);
105
106 /* Remember that the zeroth slot is used as the pointer onwards, so don't
107 include it. */
108 while (--idx > 0)
109 {
110 SV *sv = &arena [idx];
111
112 if (SvTYPE (sv) >= SVt_LAST)
113 continue;
114
115 /* temporarily disable RMAGICAL, it can easily interfere with us */
116 if ((rmagical = SvRMAGICAL (sv)))
117 SvRMAGICAL_off (sv);
118
119 if (SvTYPE (sv) >= SVt_PVMG)
120 {
121 #if !PERL_VERSION_ATLEAST (5,21,6)
122 if (SvTYPE (sv) == SVt_PVMG && SvPAD_OUR (sv))
123 {
124 /* I have no clue what this is */
125 /* maybe some placeholder for our variables for eval? */
126 /* it doesn't seem to reference anything, so we should be able to ignore it */
127 }
128 else
129 #endif
130 if (SvMAGICAL (sv)) /* name-pads use SvMAGIC for other purposes */
131 {
132 MAGIC *mg = SvMAGIC (sv);
133
134 while (mg)
135 {
136 if (mg->mg_obj == targ && mg->mg_flags & MGf_REFCOUNTED)
137 res_pair (form ("referenced (in mg_obj) by '%c' type magic attached to", mg->mg_type));
138
139 if ((SV *)mg->mg_ptr == targ)
140 res_pair (form ("%sreferenced (in mg_ptr) by '%c' type magic attached to",
141 mg->mg_len == HEf_SVKEY ? "" : "possibly ",
142 mg->mg_type));
143
144 mg = mg->mg_moremagic;
145 }
146 }
147 }
148
149 if (SvROK (sv))
150 {
151 if (SvRV (sv) == targ && !SvWEAKREF (sv) && sv != target_ref)
152 res_pair ("referenced by");
153 }
154 else
155 switch (SvTYPE (sv))
156 {
157 case SVt_PVAV:
158 if (AvREAL (sv))
159 for (i = AvFILLp (sv) + 1; i--; )
160 if (AvARRAY (sv)[i] == targ)
161 res_pair (form ("the array element %d of", i));
162
163 break;
164
165 case SVt_PVHV:
166 if (hv_iterinit ((HV *)sv))
167 {
168 HE *he;
169
170 while ((he = hv_iternext ((HV *)sv)))
171 if (HeVAL (he) == targ)
172 res_pair (form ("the hash member '%.*s' of", HeKLEN (he), HeKEY (he)));
173 }
174
175 break;
176
177 case SVt_PVCV:
178 {
179 PADLIST *padlist = CvISXSUB (cv) ? 0 : CvPADLIST (sv);
180
181 if (padlist)
182 {
183 int depth = CvDEPTH (sv);
184
185 /* Anonymous subs have a padlist but zero depth */
186 /* some hacks switch CvANON off, so we just blindly assume a minimum of 1 */
187 if (!depth && !PERL_VERSION_ATLEAST (5,21,6))
188 depth = 1;
189
190 while (depth)
191 {
192 PAD *pad = PadlistARRAY (padlist)[depth];
193
194 av_push (excl, newSVuv (PTR2UV (pad))); /* exclude pads themselves from being found */
195
196 /* The 0th pad slot is @_ */
197 if (PadARRAY (pad)[0] == targ)
198 res_pair ("the argument array for");
199
200 for (i = PadMAX (pad) + 1; --i; )
201 if (PadARRAY (pad)[i] == targ)
202 {
203 /* Values from constant functions are stored in the pad without any name */
204 PADNAME *name = padnamelist_fetch (PadlistNAMES (padlist), i);
205
206 if (name && PadnamePV (name) && *PadnamePV (name))
207 res_pair (form ("the lexical '%s' in", PadnamePV (name)));
208 else
209 res_pair ("an unnamed lexical in");
210 }
211
212 --depth;
213 }
214 }
215
216 if (CvCONST (sv) && (SV*)CvXSUBANY (sv).any_ptr == targ)
217 res_pair ("the constant value of");
218
219 if (!CvWEAKOUTSIDE (sv) && (SV*)CvOUTSIDE (sv) == targ)
220 res_pair ("the containing scope for");
221
222 if (sv == targ && CvANON (sv))
223 if (CvSTART (sv)
224 && CvSTART (sv)->op_type == OP_NEXTSTATE
225 && CopLINE ((COP *)CvSTART (sv)))
226 res_text (form ("the closure created at %s:%d",
227 CopFILE ((COP *)CvSTART (sv)) ? CopFILE ((COP *)CvSTART (sv)) : "<unknown>",
228 CopLINE ((COP *)CvSTART (sv))));
229 else
230 res_text (form ("the closure created somewhere in file %s (PLEASE REPORT!)",
231 CvFILE (sv) ? CvFILE (sv) : "<unknown>"));
232 }
233
234 break;
235
236 case SVt_PVGV:
237 if (GvGP (sv))
238 {
239 if (GvSV (sv) == (SV *)targ) res_gv ('$');
240 if (GvAV (sv) == (AV *)targ) res_gv ('@');
241 if (GvHV (sv) == (HV *)targ) res_gv ('%');
242 if (GvCV (sv) == (CV *)targ) res_gv ('&');
243 }
244
245 break;
246
247 case SVt_PVLV:
248 if (LvTARG (sv) == targ)
249 {
250 if (LvTYPE (sv) == 'y')
251 {
252 MAGIC *mg = mg_find (sv, PERL_MAGIC_defelem);
253
254 if (mg && mg->mg_obj)
255 res_pair (form ("the target for the lvalue hash element '%.*s',",
256 (int)SvCUR (mg->mg_obj), SvPV_nolen (mg->mg_obj)));
257 else
258 res_pair (form ("the target for the lvalue array element #%d,", LvTARGOFF (sv)));
259 }
260 else
261 res_pair (form ("an lvalue reference target (type '%c', ofs %d, len %d),",
262 LvTYPE (sv), LvTARGOFF (sv), LvTARGLEN (sv)));
263 }
264
265 break;
266 }
267
268 if (rmagical)
269 SvRMAGICAL_on (sv);
270 }
271 }
272
273 /* look at the mortalise stack of the current coroutine */
274 for (i = 0; i <= PL_tmps_ix; ++i)
275 if (PL_tmps_stack [i] == targ)
276 res_text ("a temporary on the stack");
277
278 if (targ == (SV*)PL_main_cv)
279 res_text ("the main body of the program");
280 }
281
282 EXTEND (SP, 2);
283 PUSHs (sv_2mortal (newRV_noinc ((SV *)about)));
284 PUSHs (sv_2mortal (newRV_noinc ((SV *)excl)));
285 }
286
287 SV *
288 ptr2ref (UV ptr)
289 CODE:
290 RETVAL = newRV_inc (INT2PTR (SV *, ptr));
291 OUTPUT:
292 RETVAL
293
294 UV
295 ref2ptr (SV *rv)
296 CODE:
297 if (!SvROK (rv))
298 croak ("argument to Devel::FindRef::ref2ptr must be a reference");
299 RETVAL = PTR2UV (SvRV (rv));
300 OUTPUT:
301 RETVAL
302
303 U32
304 _refcnt (SV *rv)
305 CODE:
306 if (!SvROK (rv))
307 croak ("argument to Devel::FindRef::_refcnt must be a reference");
308 RETVAL = SvREFCNT (SvRV (rv));
309 OUTPUT:
310 RETVAL