xref: /openbsd-src/gnu/usr.bin/perl/ext/attributes/attributes.xs (revision f2da64fbbbf1b03f09f390ab01267c93dfd77c4c)
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_NO_GET_CONTEXT
19 
20 #include "EXTERN.h"
21 #include "perl.h"
22 #include "XSUB.h"
23 
24 /*
25  * Contributed by Spider Boardman (spider.boardman@orb.nashua.nh.us).
26  */
27 
28 static int
29 modify_SV_attributes(pTHX_ SV *sv, SV **retlist, SV **attrlist, int numattrs)
30 {
31     dVAR;
32     SV *attr;
33     int nret;
34 
35     for (nret = 0 ; numattrs && (attr = *attrlist++); numattrs--) {
36 	STRLEN len;
37 	const char *name = SvPV_const(attr, len);
38 	const bool negated = (*name == '-');
39 
40 	if (negated) {
41 	    name++;
42 	    len--;
43 	}
44 	switch (SvTYPE(sv)) {
45 	case SVt_PVCV:
46 	    switch ((int)len) {
47 	    case 6:
48 		switch (name[3]) {
49 		case 'l':
50 		    if (memEQ(name, "lvalue", 6)) {
51 			bool warn =
52 			    !CvISXSUB(MUTABLE_CV(sv))
53 			 && CvROOT(MUTABLE_CV(sv))
54 			 && !CvLVALUE(MUTABLE_CV(sv)) != negated;
55 			if (negated)
56 			    CvFLAGS(MUTABLE_CV(sv)) &= ~CVf_LVALUE;
57 			else
58 			    CvFLAGS(MUTABLE_CV(sv)) |= CVf_LVALUE;
59 			if (warn) break;
60 			continue;
61 		    }
62 		    break;
63 		case 'h':
64 		    if (memEQ(name, "method", 6)) {
65 			if (negated)
66 			    CvFLAGS(MUTABLE_CV(sv)) &= ~CVf_METHOD;
67 			else
68 			    CvFLAGS(MUTABLE_CV(sv)) |= CVf_METHOD;
69 			continue;
70 		    }
71 		    break;
72 		}
73 		break;
74 	    default:
75 		if (len > 10 && memEQ(name, "prototype(", 10)) {
76 		    SV * proto = newSVpvn(name+10,len-11);
77 		    HEK *const hek = CvNAME_HEK((CV *)sv);
78 		    SV *subname;
79 		    if (name[len-1] != ')')
80 			Perl_croak(aTHX_ "Unterminated attribute parameter in attribute list");
81 		    if (hek)
82 			subname = sv_2mortal(newSVhek(hek));
83 		    else
84 			subname=(SV *)CvGV((const CV *)sv);
85 		    if (ckWARN(WARN_ILLEGALPROTO))
86 			Perl_validate_proto(aTHX_ subname, proto, TRUE);
87 		    Perl_cv_ckproto_len_flags(aTHX_ (const CV *)sv,
88 		                                    (const GV *)subname,
89 		                                    name+10,
90 		                                    len-11,
91 		                                    SvUTF8(attr));
92 		    sv_setpvn(MUTABLE_SV(sv), name+10, len-11);
93 		    if (SvUTF8(attr)) SvUTF8_on(MUTABLE_SV(sv));
94 		    continue;
95 		}
96 		break;
97 	    }
98 	    break;
99 	default:
100 	    if (memEQs(name, len, "shared")) {
101 			if (negated)
102 			    Perl_croak(aTHX_ "A variable may not be unshared");
103 			SvSHARE(sv);
104                         continue;
105 	    }
106 	    break;
107 	}
108 	/* anything recognized had a 'continue' above */
109 	*retlist++ = attr;
110 	nret++;
111     }
112 
113     return nret;
114 }
115 
116 MODULE = attributes		PACKAGE = attributes
117 
118 void
119 _modify_attrs(...)
120   PREINIT:
121     SV *rv, *sv;
122   PPCODE:
123 
124     if (items < 1) {
125 usage:
126 	croak_xs_usage(cv, "@attributes");
127     }
128 
129     rv = ST(0);
130     if (!(SvOK(rv) && SvROK(rv)))
131 	goto usage;
132     sv = SvRV(rv);
133     if (items > 1)
134 	XSRETURN(modify_SV_attributes(aTHX_ sv, &ST(0), &ST(1), items-1));
135 
136     XSRETURN(0);
137 
138 void
139 _fetch_attrs(...)
140   PROTOTYPE: $
141   PREINIT:
142     SV *rv, *sv;
143     cv_flags_t cvflags;
144   PPCODE:
145     if (items != 1) {
146 usage:
147 	croak_xs_usage(cv, "$reference");
148     }
149 
150     rv = ST(0);
151     if (!(SvOK(rv) && SvROK(rv)))
152 	goto usage;
153     sv = SvRV(rv);
154 
155     switch (SvTYPE(sv)) {
156     case SVt_PVCV:
157 	cvflags = CvFLAGS((const CV *)sv);
158 	if (cvflags & CVf_LVALUE)
159 	    XPUSHs(newSVpvs_flags("lvalue", SVs_TEMP));
160 	if (cvflags & CVf_METHOD)
161 	    XPUSHs(newSVpvs_flags("method", SVs_TEMP));
162 	break;
163     default:
164 	break;
165     }
166 
167     PUTBACK;
168 
169 void
170 _guess_stash(...)
171   PROTOTYPE: $
172   PREINIT:
173     SV *rv, *sv;
174     dXSTARG;
175   PPCODE:
176     if (items != 1) {
177 usage:
178 	croak_xs_usage(cv, "$reference");
179     }
180 
181     rv = ST(0);
182     ST(0) = TARG;
183     if (!(SvOK(rv) && SvROK(rv)))
184 	goto usage;
185     sv = SvRV(rv);
186 
187     if (SvOBJECT(sv))
188 	Perl_sv_sethek(aTHX_ TARG, HvNAME_HEK(SvSTASH(sv)));
189 #if 0	/* this was probably a bad idea */
190     else if (SvPADMY(sv))
191 	sv_setsv(TARG, &PL_sv_no);	/* unblessed lexical */
192 #endif
193     else {
194 	const HV *stash = NULL;
195 	switch (SvTYPE(sv)) {
196 	case SVt_PVCV:
197 	    if (CvGV(sv) && isGV(CvGV(sv)) && GvSTASH(CvGV(sv)))
198 		stash = GvSTASH(CvGV(sv));
199 	    else if (/* !CvANON(sv) && */ CvSTASH(sv))
200 		stash = CvSTASH(sv);
201 	    break;
202 	case SVt_PVGV:
203 	    if (isGV_with_GP(sv) && GvGP(sv) && GvESTASH(MUTABLE_GV(sv)))
204 		stash = GvESTASH(MUTABLE_GV(sv));
205 	    break;
206 	default:
207 	    break;
208 	}
209 	if (stash)
210 	    Perl_sv_sethek(aTHX_ TARG, HvNAME_HEK(stash));
211     }
212 
213     SvSETMAGIC(TARG);
214     XSRETURN(1);
215 
216 void
217 reftype(...)
218   PROTOTYPE: $
219   PREINIT:
220     SV *rv, *sv;
221     dXSTARG;
222   PPCODE:
223     if (items != 1) {
224 usage:
225 	croak_xs_usage(cv, "$reference");
226     }
227 
228     rv = ST(0);
229     ST(0) = TARG;
230     SvGETMAGIC(rv);
231     if (!(SvOK(rv) && SvROK(rv)))
232 	goto usage;
233     sv = SvRV(rv);
234     sv_setpv(TARG, sv_reftype(sv, 0));
235     SvSETMAGIC(TARG);
236 
237     XSRETURN(1);
238 /*
239  * Local variables:
240  * c-indentation-style: bsd
241  * c-basic-offset: 4
242  * indent-tabs-mode: nil
243  * End:
244  *
245  * ex: set ts=8 sts=4 sw=4 et:
246  */
247