1 /* xsutils.c
2 *
3 * Copyright (C) 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008
4 * by Larry Wall and others
5 *
6 * You may distribute under the terms of either the GNU General Public
7 * License or the Artistic License, as specified in the README file.
8 *
9 */
10
11 /*
12 * 'Perilous to us all are the devices of an art deeper than we possess
13 * ourselves.' --Gandalf
14 *
15 * [p.597 of _The Lord of the Rings_, III/xi: "The Palantír"]
16 */
17
18 #define PERL_EXT
19
20 #define PERL_NO_GET_CONTEXT
21
22 #include "EXTERN.h"
23 #include "perl.h"
24 #include "XSUB.h"
25
26 /*
27 * Contributed by Spider Boardman (spider.boardman@orb.nashua.nh.us).
28 */
29
30 static int
modify_SV_attributes(pTHX_ SV * sv,SV ** retlist,SV ** attrlist,int numattrs)31 modify_SV_attributes(pTHX_ SV *sv, SV **retlist, SV **attrlist, int numattrs)
32 {
33 SV *attr;
34 int nret;
35
36 for (nret = 0 ; numattrs && (attr = *attrlist++); numattrs--) {
37 STRLEN len;
38 const char *name = SvPV_const(attr, len);
39 const bool negated = (*name == '-');
40
41 if (negated) {
42 name++;
43 len--;
44 }
45 switch (SvTYPE(sv)) {
46 case SVt_PVCV:
47 switch ((int)len) {
48 case 5:
49 if (memEQs(name, 5, "const")) {
50 if (negated)
51 CvANONCONST_off(sv);
52 else {
53 const bool warn = (!CvANON(sv) || CvCLONED(sv))
54 && !CvANONCONST(sv);
55 CvANONCONST_on(sv);
56 if (warn)
57 break;
58 }
59 continue;
60 }
61 break;
62 case 6:
63 switch (name[3]) {
64 case 'l':
65 if (memEQs(name, 6, "lvalue")) {
66 bool warn =
67 !CvISXSUB(MUTABLE_CV(sv))
68 && CvROOT(MUTABLE_CV(sv))
69 && cBOOL(CvLVALUE(MUTABLE_CV(sv))) == negated;
70 if (negated)
71 CvFLAGS(MUTABLE_CV(sv)) &= ~CVf_LVALUE;
72 else
73 CvFLAGS(MUTABLE_CV(sv)) |= CVf_LVALUE;
74 if (warn) break;
75 continue;
76 }
77 break;
78 case 'h':
79 if (memEQs(name, 6, "method")) {
80 if (negated)
81 CvFLAGS(MUTABLE_CV(sv)) &= ~CVf_METHOD;
82 else
83 CvFLAGS(MUTABLE_CV(sv)) |= CVf_METHOD;
84 continue;
85 }
86 break;
87 }
88 break;
89 default:
90 if (memBEGINPs(name, len, "prototype(")) {
91 const STRLEN proto_len = sizeof("prototype(") - 1;
92 SV * proto = newSVpvn(name + proto_len, len - proto_len - 1);
93 HEK *const hek = CvNAME_HEK((CV *)sv);
94 SV *subname;
95 if (name[len-1] != ')')
96 Perl_croak(aTHX_ "Unterminated attribute parameter in attribute list");
97 if (hek)
98 subname = sv_2mortal(newSVhek(hek));
99 else
100 subname=(SV *)CvGV((const CV *)sv);
101 if (ckWARN(WARN_ILLEGALPROTO))
102 Perl_validate_proto(aTHX_ subname, proto, TRUE, 0);
103 Perl_cv_ckproto_len_flags(aTHX_ (const CV *)sv,
104 (const GV *)subname,
105 name+10,
106 len-11,
107 SvUTF8(attr));
108 sv_setpvn(MUTABLE_SV(sv), name+10, len-11);
109 if (SvUTF8(attr)) SvUTF8_on(MUTABLE_SV(sv));
110 continue;
111 }
112 break;
113 }
114 break;
115 default:
116 if (memEQs(name, len, "shared")) {
117 if (negated)
118 Perl_croak(aTHX_ "A variable may not be unshared");
119 SvSHARE(sv);
120 continue;
121 }
122 break;
123 }
124 /* anything recognized had a 'continue' above */
125 *retlist++ = attr;
126 nret++;
127 }
128
129 return nret;
130 }
131
132 MODULE = attributes PACKAGE = attributes
133
134 void
135 _modify_attrs(...)
136 PREINIT:
137 SV *rv, *sv;
138 PPCODE:
139
140 if (items < 1) {
141 usage:
142 croak_xs_usage(cv, "@attributes");
143 }
144
145 rv = ST(0);
146 if (!(SvOK(rv) && SvROK(rv)))
147 goto usage;
148 sv = SvRV(rv);
149 if (items > 1)
150 XSRETURN(modify_SV_attributes(aTHX_ sv, &ST(0), &ST(1), items-1));
151
152 XSRETURN(0);
153
154 void
155 _fetch_attrs(...)
156 PROTOTYPE: $
157 PREINIT:
158 SV *rv, *sv;
159 cv_flags_t cvflags;
160 PPCODE:
161 if (items != 1) {
162 usage:
163 croak_xs_usage(cv, "$reference");
164 }
165
166 rv = ST(0);
167 if (!(SvOK(rv) && SvROK(rv)))
168 goto usage;
169 sv = SvRV(rv);
170
171 switch (SvTYPE(sv)) {
172 case SVt_PVCV:
173 cvflags = CvFLAGS((const CV *)sv);
174 if (cvflags & CVf_LVALUE)
175 XPUSHs(newSVpvs_flags("lvalue", SVs_TEMP));
176 if (cvflags & CVf_METHOD)
177 XPUSHs(newSVpvs_flags("method", SVs_TEMP));
178 break;
179 default:
180 break;
181 }
182
183 PUTBACK;
184
185 void
186 _guess_stash(...)
187 PROTOTYPE: $
188 PREINIT:
189 SV *rv, *sv;
190 dXSTARG;
191 PPCODE:
192 if (items != 1) {
193 usage:
194 croak_xs_usage(cv, "$reference");
195 }
196
197 rv = ST(0);
198 ST(0) = TARG;
199 if (!(SvOK(rv) && SvROK(rv)))
200 goto usage;
201 sv = SvRV(rv);
202
203 if (SvOBJECT(sv))
204 Perl_sv_sethek(aTHX_ TARG, HvNAME_HEK(SvSTASH(sv)));
205 #if 0 /* this was probably a bad idea */
206 else if (SvPADMY(sv))
207 sv_setsv(TARG, &PL_sv_no); /* unblessed lexical */
208 #endif
209 else {
210 const HV *stash = NULL;
211 switch (SvTYPE(sv)) {
212 case SVt_PVCV:
213 if (CvGV(sv) && isGV(CvGV(sv)) && GvSTASH(CvGV(sv)))
214 stash = GvSTASH(CvGV(sv));
215 else if (/* !CvANON(sv) && */ CvSTASH(sv))
216 stash = CvSTASH(sv);
217 break;
218 case SVt_PVGV:
219 if (isGV_with_GP(sv) && GvGP(sv) && GvESTASH(MUTABLE_GV(sv)))
220 stash = GvESTASH(MUTABLE_GV(sv));
221 break;
222 default:
223 break;
224 }
225 if (stash)
226 Perl_sv_sethek(aTHX_ TARG, HvNAME_HEK(stash));
227 }
228
229 SvSETMAGIC(TARG);
230 XSRETURN(1);
231
232 void
233 reftype(...)
234 PROTOTYPE: $
235 PREINIT:
236 SV *rv, *sv;
237 dXSTARG;
238 PPCODE:
239 if (items != 1) {
240 usage:
241 croak_xs_usage(cv, "$reference");
242 }
243
244 rv = ST(0);
245 ST(0) = TARG;
246 SvGETMAGIC(rv);
247 if (!(SvOK(rv) && SvROK(rv)))
248 goto usage;
249 sv = SvRV(rv);
250 sv_setpv(TARG, sv_reftype(sv, 0));
251 SvSETMAGIC(TARG);
252
253 XSRETURN(1);
254 /*
255 * ex: set ts=8 sts=4 sw=4 et:
256 */
257