xref: /openbsd-src/gnu/usr.bin/perl/pp.h (revision a28daedfc357b214be5c701aa8ba8adb29a7f1c2)
1 /*    pp.h
2  *
3  *    Copyright (C) 1991, 1992, 1993, 1994, 1995, 1996, 1998, 1999, 2000,
4  *    2001, 2002, 2003, 2004, 2005, 2006, 2007, 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 #define PP(s) OP * Perl_##s(pTHX)
12 
13 /*
14 =head1 Stack Manipulation Macros
15 
16 =for apidoc AmU||SP
17 Stack pointer.  This is usually handled by C<xsubpp>.  See C<dSP> and
18 C<SPAGAIN>.
19 
20 =for apidoc AmU||MARK
21 Stack marker variable for the XSUB.  See C<dMARK>.
22 
23 =for apidoc Am|void|PUSHMARK|SP
24 Opening bracket for arguments on a callback.  See C<PUTBACK> and
25 L<perlcall>.
26 
27 =for apidoc Ams||dSP
28 Declares a local copy of perl's stack pointer for the XSUB, available via
29 the C<SP> macro.  See C<SP>.
30 
31 =for apidoc ms||djSP
32 
33 Declare Just C<SP>. This is actually identical to C<dSP>, and declares
34 a local copy of perl's stack pointer, available via the C<SP> macro.
35 See C<SP>.  (Available for backward source code compatibility with the
36 old (Perl 5.005) thread model.)
37 
38 =for apidoc Ams||dMARK
39 Declare a stack marker variable, C<mark>, for the XSUB.  See C<MARK> and
40 C<dORIGMARK>.
41 
42 =for apidoc Ams||dORIGMARK
43 Saves the original stack mark for the XSUB.  See C<ORIGMARK>.
44 
45 =for apidoc AmU||ORIGMARK
46 The original stack mark for the XSUB.  See C<dORIGMARK>.
47 
48 =for apidoc Ams||SPAGAIN
49 Refetch the stack pointer.  Used after a callback.  See L<perlcall>.
50 
51 =cut */
52 
53 #undef SP /* Solaris 2.7 i386 has this in /usr/include/sys/reg.h */
54 #define SP sp
55 #define MARK mark
56 #define TARG targ
57 
58 #define PUSHMARK(p)	\
59 	STMT_START {					\
60 	    if (++PL_markstack_ptr == PL_markstack_max)	\
61 	    markstack_grow();				\
62 	    *PL_markstack_ptr = (I32)((p) - PL_stack_base);\
63 	} STMT_END
64 
65 #define TOPMARK		(*PL_markstack_ptr)
66 #define POPMARK		(*PL_markstack_ptr--)
67 
68 #define dSP		SV **sp = PL_stack_sp
69 #define djSP		dSP
70 #define dMARK		register SV **mark = PL_stack_base + POPMARK
71 #define dORIGMARK	const I32 origmark = (I32)(mark - PL_stack_base)
72 #define ORIGMARK	(PL_stack_base + origmark)
73 
74 #define SPAGAIN		sp = PL_stack_sp
75 #define MSPAGAIN	STMT_START { sp = PL_stack_sp; mark = ORIGMARK; } STMT_END
76 
77 #define GETTARGETSTACKED targ = (PL_op->op_flags & OPf_STACKED ? POPs : PAD_SV(PL_op->op_targ))
78 #define dTARGETSTACKED SV * GETTARGETSTACKED
79 
80 #define GETTARGET targ = PAD_SV(PL_op->op_targ)
81 #define dTARGET SV * GETTARGET
82 
83 #define GETATARGET targ = (PL_op->op_flags & OPf_STACKED ? sp[-1] : PAD_SV(PL_op->op_targ))
84 #define dATARGET SV * GETATARGET
85 
86 #define dTARG SV *targ
87 
88 #define NORMAL PL_op->op_next
89 #define DIE return Perl_die
90 
91 /*
92 =for apidoc Ams||PUTBACK
93 Closing bracket for XSUB arguments.  This is usually handled by C<xsubpp>.
94 See C<PUSHMARK> and L<perlcall> for other uses.
95 
96 =for apidoc Amn|SV*|POPs
97 Pops an SV off the stack.
98 
99 =for apidoc Amn|char*|POPp
100 Pops a string off the stack. Deprecated. New code should use POPpx.
101 
102 =for apidoc Amn|char*|POPpx
103 Pops a string off the stack.
104 
105 =for apidoc Amn|char*|POPpbytex
106 Pops a string off the stack which must consist of bytes i.e. characters < 256.
107 
108 =for apidoc Amn|NV|POPn
109 Pops a double off the stack.
110 
111 =for apidoc Amn|IV|POPi
112 Pops an integer off the stack.
113 
114 =for apidoc Amn|long|POPl
115 Pops a long off the stack.
116 
117 =cut
118 */
119 
120 #define PUTBACK		PL_stack_sp = sp
121 #define RETURN		return (PUTBACK, NORMAL)
122 #define RETURNOP(o)	return (PUTBACK, o)
123 #define RETURNX(x)	return (x, PUTBACK, NORMAL)
124 
125 #define POPs		(*sp--)
126 #define POPp		(SvPVx(POPs, PL_na))		/* deprecated */
127 #define POPpx		(SvPVx_nolen(POPs))
128 #define POPpconstx	(SvPVx_nolen_const(POPs))
129 #define POPpbytex	(SvPVbytex_nolen(POPs))
130 #define POPn		(SvNVx(POPs))
131 #define POPi		((IV)SvIVx(POPs))
132 #define POPu		((UV)SvUVx(POPs))
133 #define POPl		((long)SvIVx(POPs))
134 #define POPul		((unsigned long)SvIVx(POPs))
135 #ifdef HAS_QUAD
136 #define POPq		((Quad_t)SvIVx(POPs))
137 #define POPuq		((Uquad_t)SvUVx(POPs))
138 #endif
139 
140 #define TOPs		(*sp)
141 #define TOPm1s		(*(sp-1))
142 #define TOPp1s		(*(sp+1))
143 #define TOPp		(SvPV(TOPs, PL_na))		/* deprecated */
144 #define TOPpx		(SvPV_nolen(TOPs))
145 #define TOPn		(SvNV(TOPs))
146 #define TOPi		((IV)SvIV(TOPs))
147 #define TOPu		((UV)SvUV(TOPs))
148 #define TOPl		((long)SvIV(TOPs))
149 #define TOPul		((unsigned long)SvUV(TOPs))
150 #ifdef HAS_QUAD
151 #define TOPq		((Quad_t)SvIV(TOPs))
152 #define TOPuq		((Uquad_t)SvUV(TOPs))
153 #endif
154 
155 /* Go to some pains in the rare event that we must extend the stack. */
156 
157 /*
158 =for apidoc Am|void|EXTEND|SP|int nitems
159 Used to extend the argument stack for an XSUB's return values. Once
160 used, guarantees that there is room for at least C<nitems> to be pushed
161 onto the stack.
162 
163 =for apidoc Am|void|PUSHs|SV* sv
164 Push an SV onto the stack.  The stack must have room for this element.
165 Does not handle 'set' magic.  Does not use C<TARG>.  See also C<PUSHmortal>,
166 C<XPUSHs> and C<XPUSHmortal>.
167 
168 =for apidoc Am|void|PUSHp|char* str|STRLEN len
169 Push a string onto the stack.  The stack must have room for this element.
170 The C<len> indicates the length of the string.  Handles 'set' magic.  Uses
171 C<TARG>, so C<dTARGET> or C<dXSTARG> should be called to declare it.  Do not
172 call multiple C<TARG>-oriented macros to return lists from XSUB's - see
173 C<mPUSHp> instead.  See also C<XPUSHp> and C<mXPUSHp>.
174 
175 =for apidoc Am|void|PUSHn|NV nv
176 Push a double onto the stack.  The stack must have room for this element.
177 Handles 'set' magic.  Uses C<TARG>, so C<dTARGET> or C<dXSTARG> should be
178 called to declare it.  Do not call multiple C<TARG>-oriented macros to
179 return lists from XSUB's - see C<mPUSHn> instead.  See also C<XPUSHn> and
180 C<mXPUSHn>.
181 
182 =for apidoc Am|void|PUSHi|IV iv
183 Push an integer onto the stack.  The stack must have room for this element.
184 Handles 'set' magic.  Uses C<TARG>, so C<dTARGET> or C<dXSTARG> should be
185 called to declare it.  Do not call multiple C<TARG>-oriented macros to
186 return lists from XSUB's - see C<mPUSHi> instead.  See also C<XPUSHi> and
187 C<mXPUSHi>.
188 
189 =for apidoc Am|void|PUSHu|UV uv
190 Push an unsigned integer onto the stack.  The stack must have room for this
191 element.  Handles 'set' magic.  Uses C<TARG>, so C<dTARGET> or C<dXSTARG>
192 should be called to declare it.  Do not call multiple C<TARG>-oriented
193 macros to return lists from XSUB's - see C<mPUSHu> instead.  See also
194 C<XPUSHu> and C<mXPUSHu>.
195 
196 =for apidoc Am|void|XPUSHs|SV* sv
197 Push an SV onto the stack, extending the stack if necessary.  Does not
198 handle 'set' magic.  Does not use C<TARG>.  See also C<XPUSHmortal>,
199 C<PUSHs> and C<PUSHmortal>.
200 
201 =for apidoc Am|void|XPUSHp|char* str|STRLEN len
202 Push a string onto the stack, extending the stack if necessary.  The C<len>
203 indicates the length of the string.  Handles 'set' magic.  Uses C<TARG>, so
204 C<dTARGET> or C<dXSTARG> should be called to declare it.  Do not call
205 multiple C<TARG>-oriented macros to return lists from XSUB's - see
206 C<mXPUSHp> instead.  See also C<PUSHp> and C<mPUSHp>.
207 
208 =for apidoc Am|void|XPUSHn|NV nv
209 Push a double onto the stack, extending the stack if necessary.  Handles
210 'set' magic.  Uses C<TARG>, so C<dTARGET> or C<dXSTARG> should be called to
211 declare it.  Do not call multiple C<TARG>-oriented macros to return lists
212 from XSUB's - see C<mXPUSHn> instead.  See also C<PUSHn> and C<mPUSHn>.
213 
214 =for apidoc Am|void|XPUSHi|IV iv
215 Push an integer onto the stack, extending the stack if necessary.  Handles
216 'set' magic.  Uses C<TARG>, so C<dTARGET> or C<dXSTARG> should be called to
217 declare it.  Do not call multiple C<TARG>-oriented macros to return lists
218 from XSUB's - see C<mXPUSHi> instead.  See also C<PUSHi> and C<mPUSHi>.
219 
220 =for apidoc Am|void|XPUSHu|UV uv
221 Push an unsigned integer onto the stack, extending the stack if necessary.
222 Handles 'set' magic.  Uses C<TARG>, so C<dTARGET> or C<dXSTARG> should be
223 called to declare it.  Do not call multiple C<TARG>-oriented macros to
224 return lists from XSUB's - see C<mXPUSHu> instead.  See also C<PUSHu> and
225 C<mPUSHu>.
226 
227 =for apidoc Am|void|PUSHmortal
228 Push a new mortal SV onto the stack.  The stack must have room for this
229 element.  Does not handle 'set' magic.  Does not use C<TARG>.  See also
230 C<PUSHs>, C<XPUSHmortal> and C<XPUSHs>.
231 
232 =for apidoc Am|void|mPUSHp|char* str|STRLEN len
233 Push a string onto the stack.  The stack must have room for this element.
234 The C<len> indicates the length of the string.  Handles 'set' magic.  Does
235 not use C<TARG>.  See also C<PUSHp>, C<mXPUSHp> and C<XPUSHp>.
236 
237 =for apidoc Am|void|mPUSHn|NV nv
238 Push a double onto the stack.  The stack must have room for this element.
239 Handles 'set' magic.  Does not use C<TARG>.  See also C<PUSHn>, C<mXPUSHn>
240 and C<XPUSHn>.
241 
242 =for apidoc Am|void|mPUSHi|IV iv
243 Push an integer onto the stack.  The stack must have room for this element.
244 Handles 'set' magic.  Does not use C<TARG>.  See also C<PUSHi>, C<mXPUSHi>
245 and C<XPUSHi>.
246 
247 =for apidoc Am|void|mPUSHu|UV uv
248 Push an unsigned integer onto the stack.  The stack must have room for this
249 element.  Handles 'set' magic.  Does not use C<TARG>.  See also C<PUSHu>,
250 C<mXPUSHu> and C<XPUSHu>.
251 
252 =for apidoc Am|void|XPUSHmortal
253 Push a new mortal SV onto the stack, extending the stack if necessary.  Does
254 not handle 'set' magic.  Does not use C<TARG>.  See also C<XPUSHs>,
255 C<PUSHmortal> and C<PUSHs>.
256 
257 =for apidoc Am|void|mXPUSHp|char* str|STRLEN len
258 Push a string onto the stack, extending the stack if necessary.  The C<len>
259 indicates the length of the string.  Handles 'set' magic.  Does not use
260 C<TARG>.  See also C<XPUSHp>, C<mPUSHp> and C<PUSHp>.
261 
262 =for apidoc Am|void|mXPUSHn|NV nv
263 Push a double onto the stack, extending the stack if necessary.  Handles
264 'set' magic.  Does not use C<TARG>.  See also C<XPUSHn>, C<mPUSHn> and
265 C<PUSHn>.
266 
267 =for apidoc Am|void|mXPUSHi|IV iv
268 Push an integer onto the stack, extending the stack if necessary.  Handles
269 'set' magic.  Does not use C<TARG>.  See also C<XPUSHi>, C<mPUSHi> and
270 C<PUSHi>.
271 
272 =for apidoc Am|void|mXPUSHu|UV uv
273 Push an unsigned integer onto the stack, extending the stack if necessary.
274 Handles 'set' magic.  Does not use C<TARG>.  See also C<XPUSHu>, C<mPUSHu>
275 and C<PUSHu>.
276 
277 =cut
278 */
279 
280 #define EXTEND(p,n)	STMT_START { if (PL_stack_max - p < (int)(n)) {		\
281 			    sp = stack_grow(sp,p, (int) (n));		\
282 			} } STMT_END
283 
284 /* Same thing, but update mark register too. */
285 #define MEXTEND(p,n)	STMT_START {if (PL_stack_max - p < (int)(n)) {	\
286 			    const int markoff = mark - PL_stack_base;	\
287 			    sp = stack_grow(sp,p,(int) (n));		\
288 			    mark = PL_stack_base + markoff;		\
289 			} } STMT_END
290 
291 #define PUSHs(s)	(*++sp = (s))
292 #define PUSHTARG	STMT_START { SvSETMAGIC(TARG); PUSHs(TARG); } STMT_END
293 #define PUSHp(p,l)	STMT_START { sv_setpvn(TARG, (p), (l)); PUSHTARG; } STMT_END
294 #define PUSHn(n)	STMT_START { sv_setnv(TARG, (NV)(n)); PUSHTARG; } STMT_END
295 #define PUSHi(i)	STMT_START { sv_setiv(TARG, (IV)(i)); PUSHTARG; } STMT_END
296 #define PUSHu(u)	STMT_START { sv_setuv(TARG, (UV)(u)); PUSHTARG; } STMT_END
297 
298 #define XPUSHs(s)	STMT_START { EXTEND(sp,1); (*++sp = (s)); } STMT_END
299 #define XPUSHTARG	STMT_START { SvSETMAGIC(TARG); XPUSHs(TARG); } STMT_END
300 #define XPUSHp(p,l)	STMT_START { sv_setpvn(TARG, (p), (l)); XPUSHTARG; } STMT_END
301 #define XPUSHn(n)	STMT_START { sv_setnv(TARG, (NV)(n)); XPUSHTARG; } STMT_END
302 #define XPUSHi(i)	STMT_START { sv_setiv(TARG, (IV)(i)); XPUSHTARG; } STMT_END
303 #define XPUSHu(u)	STMT_START { sv_setuv(TARG, (UV)(u)); XPUSHTARG; } STMT_END
304 #define XPUSHundef	STMT_START { SvOK_off(TARG); XPUSHs(TARG); } STMT_END
305 
306 #define PUSHmortal	PUSHs(sv_newmortal())
307 #define mPUSHp(p,l)	sv_setpvn_mg(PUSHmortal, (p), (l))
308 #define mPUSHn(n)	sv_setnv_mg(PUSHmortal, (NV)(n))
309 #define mPUSHi(i)	sv_setiv_mg(PUSHmortal, (IV)(i))
310 #define mPUSHu(u)	sv_setuv_mg(PUSHmortal, (UV)(u))
311 
312 #define XPUSHmortal	XPUSHs(sv_newmortal())
313 #define mXPUSHp(p,l)	STMT_START { EXTEND(sp,1); sv_setpvn_mg(PUSHmortal, (p), (l)); } STMT_END
314 #define mXPUSHn(n)	STMT_START { EXTEND(sp,1); sv_setnv_mg(PUSHmortal, (NV)(n)); } STMT_END
315 #define mXPUSHi(i)	STMT_START { EXTEND(sp,1); sv_setiv_mg(PUSHmortal, (IV)(i)); } STMT_END
316 #define mXPUSHu(u)	STMT_START { EXTEND(sp,1); sv_setuv_mg(PUSHmortal, (UV)(u)); } STMT_END
317 
318 #define SETs(s)		(*sp = s)
319 #define SETTARG		STMT_START { SvSETMAGIC(TARG); SETs(TARG); } STMT_END
320 #define SETp(p,l)	STMT_START { sv_setpvn(TARG, (p), (l)); SETTARG; } STMT_END
321 #define SETn(n)		STMT_START { sv_setnv(TARG, (NV)(n)); SETTARG; } STMT_END
322 #define SETi(i)		STMT_START { sv_setiv(TARG, (IV)(i)); SETTARG; } STMT_END
323 #define SETu(u)		STMT_START { sv_setuv(TARG, (UV)(u)); SETTARG; } STMT_END
324 
325 #define dTOPss		SV *sv = TOPs
326 #define dPOPss		SV *sv = POPs
327 #define dTOPnv		NV value = TOPn
328 #define dPOPnv		NV value = POPn
329 #define dTOPiv		IV value = TOPi
330 #define dPOPiv		IV value = POPi
331 #define dTOPuv		UV value = TOPu
332 #define dPOPuv		UV value = POPu
333 #ifdef HAS_QUAD
334 #define dTOPqv		Quad_t value = TOPu
335 #define dPOPqv		Quad_t value = POPu
336 #define dTOPuqv		Uquad_t value = TOPuq
337 #define dPOPuqv		Uquad_t value = POPuq
338 #endif
339 
340 #define dPOPXssrl(X)	SV *right = POPs; SV *left = CAT2(X,s)
341 #define dPOPXnnrl(X)	NV right = POPn; NV left = CAT2(X,n)
342 #define dPOPXiirl(X)	IV right = POPi; IV left = CAT2(X,i)
343 
344 #define USE_LEFT(sv) \
345 	(SvOK(sv) || SvGMAGICAL(sv) || !(PL_op->op_flags & OPf_STACKED))
346 #define dPOPXnnrl_ul(X)	\
347     NV right = POPn;				\
348     SV *leftsv = CAT2(X,s);				\
349     NV left = USE_LEFT(leftsv) ? SvNV(leftsv) : 0.0
350 #define dPOPXiirl_ul(X) \
351     IV right = POPi;					\
352     SV *leftsv = CAT2(X,s);				\
353     IV left = USE_LEFT(leftsv) ? SvIV(leftsv) : 0
354 
355 #define dPOPPOPssrl	dPOPXssrl(POP)
356 #define dPOPPOPnnrl	dPOPXnnrl(POP)
357 #define dPOPPOPnnrl_ul	dPOPXnnrl_ul(POP)
358 #define dPOPPOPiirl	dPOPXiirl(POP)
359 #define dPOPPOPiirl_ul	dPOPXiirl_ul(POP)
360 
361 #define dPOPTOPssrl	dPOPXssrl(TOP)
362 #define dPOPTOPnnrl	dPOPXnnrl(TOP)
363 #define dPOPTOPnnrl_ul	dPOPXnnrl_ul(TOP)
364 #define dPOPTOPiirl	dPOPXiirl(TOP)
365 #define dPOPTOPiirl_ul	dPOPXiirl_ul(TOP)
366 
367 #define RETPUSHYES	RETURNX(PUSHs(&PL_sv_yes))
368 #define RETPUSHNO	RETURNX(PUSHs(&PL_sv_no))
369 #define RETPUSHUNDEF	RETURNX(PUSHs(&PL_sv_undef))
370 
371 #define RETSETYES	RETURNX(SETs(&PL_sv_yes))
372 #define RETSETNO	RETURNX(SETs(&PL_sv_no))
373 #define RETSETUNDEF	RETURNX(SETs(&PL_sv_undef))
374 
375 #define ARGTARG		PL_op->op_targ
376 
377     /* See OPpTARGET_MY: */
378 #define MAXARG		(PL_op->op_private & 15)
379 
380 #define SWITCHSTACK(f,t) \
381     STMT_START {							\
382 	AvFILLp(f) = sp - PL_stack_base;				\
383 	PL_stack_base = AvARRAY(t);					\
384 	PL_stack_max = PL_stack_base + AvMAX(t);			\
385 	sp = PL_stack_sp = PL_stack_base + AvFILLp(t);			\
386 	PL_curstack = t;						\
387     } STMT_END
388 
389 #define EXTEND_MORTAL(n) \
390     STMT_START {							\
391 	if (PL_tmps_ix + (n) >= PL_tmps_max)				\
392 	    tmps_grow(n);						\
393     } STMT_END
394 
395 #define AMGf_noright	1
396 #define AMGf_noleft	2
397 #define AMGf_assign	4
398 #define AMGf_unary	8
399 
400 #define tryAMAGICbinW_var(meth_enum,assign,set) STMT_START { \
401 	    SV* const left = *(sp-1); \
402 	    SV* const right = *(sp); \
403 	    if ((SvAMAGIC(left)||SvAMAGIC(right))) {\
404 		SV * const tmpsv = amagic_call(left, \
405 				   right, \
406 				   (meth_enum), \
407 				   (assign)? AMGf_assign: 0); \
408 		if (tmpsv) { \
409 		    SPAGAIN; \
410 		    (void)POPs; set(tmpsv); RETURN; } \
411 		} \
412 	} STMT_END
413 
414 #define tryAMAGICbinW(meth,assign,set) \
415     tryAMAGICbinW_var(CAT2(meth,_amg),assign,set)
416 
417 #define tryAMAGICbin_var(meth_enum,assign) \
418 		tryAMAGICbinW_var(meth_enum,assign,SETsv)
419 #define tryAMAGICbin(meth,assign) \
420 		tryAMAGICbin_var(CAT2(meth,_amg),assign)
421 
422 #define tryAMAGICbinSET(meth,assign) tryAMAGICbinW(meth,assign,SETs)
423 
424 #define tryAMAGICbinSET_var(meth_enum,assign) \
425     tryAMAGICbinW_var(meth_enum,assign,SETs)
426 
427 #define AMG_CALLun_var(sv,meth_enum) amagic_call(sv,&PL_sv_undef,  \
428 					meth_enum,AMGf_noright | AMGf_unary)
429 #define AMG_CALLun(sv,meth) AMG_CALLun_var(sv,CAT2(meth,_amg))
430 
431 #define AMG_CALLbinL(left,right,meth) \
432             amagic_call(left,right,CAT2(meth,_amg),AMGf_noright)
433 
434 #define tryAMAGICunW_var(meth_enum,set,shift,ret) STMT_START { \
435 	    SV* tmpsv; \
436 	    SV* arg= sp[shift]; \
437           if(0) goto am_again;  /* shut up unused warning */ \
438 	  am_again: \
439 	    if ((SvAMAGIC(arg))&&\
440 		(tmpsv=AMG_CALLun_var(arg,(meth_enum)))) {\
441 	       SPAGAIN; if (shift) sp += shift; \
442 	       set(tmpsv); ret; } \
443 	} STMT_END
444 #define tryAMAGICunW(meth,set,shift,ret) \
445 	tryAMAGICunW_var(CAT2(meth,_amg),set,shift,ret)
446 
447 #define FORCE_SETs(sv) STMT_START { sv_setsv(TARG, (sv)); SETTARG; } STMT_END
448 
449 #define tryAMAGICun_var(meth_enum) tryAMAGICunW_var(meth_enum,SETsvUN,0,RETURN)
450 #define tryAMAGICun(meth)	tryAMAGICun_var(CAT2(meth,_amg))
451 #define tryAMAGICunSET(meth)	tryAMAGICunW(meth,SETs,0,RETURN)
452 #define tryAMAGICunTARGET(meth, shift)					\
453 	STMT_START { dSP; sp--; 	/* get TARGET from below PL_stack_sp */		\
454 	    { dTARGETSTACKED; 						\
455 		{ dSP; tryAMAGICunW(meth,FORCE_SETs,shift,RETURN);}}} STMT_END
456 
457 #define setAGAIN(ref)	\
458     STMT_START {					\
459 	sv = ref;					\
460 	if (!SvROK(ref))				\
461 	    Perl_croak(aTHX_ "Overloaded dereference did not return a reference");	\
462 	if (ref != arg && SvRV(ref) != SvRV(arg)) {	\
463 	    arg = ref;					\
464 	    goto am_again;				\
465 	}						\
466     } STMT_END
467 
468 #define tryAMAGICunDEREF(meth) tryAMAGICunW(meth,setAGAIN,0,(void)0)
469 #define tryAMAGICunDEREF_var(meth_enum) \
470 	tryAMAGICunW_var(meth_enum,setAGAIN,0,(void)0)
471 
472 #define opASSIGN (PL_op->op_flags & OPf_STACKED)
473 #define SETsv(sv)	STMT_START {					\
474 		if (opASSIGN || (SvFLAGS(TARG) & SVs_PADMY))		\
475 		   { sv_setsv(TARG, (sv)); SETTARG; }			\
476 		else SETs(sv); } STMT_END
477 
478 #define SETsvUN(sv)	STMT_START {					\
479 		if (SvFLAGS(TARG) & SVs_PADMY)		\
480 		   { sv_setsv(TARG, (sv)); SETTARG; }			\
481 		else SETs(sv); } STMT_END
482 
483 /* newSVsv does not behave as advertised, so we copy missing
484  * information by hand */
485 
486 /* SV* ref causes confusion with the member variable
487    changed SV* ref to SV* tmpRef */
488 #define RvDEEPCP(rv) STMT_START { SV* tmpRef=SvRV(rv);      \
489   if (SvREFCNT(tmpRef)>1) {                 \
490     SvRV_set(rv, AMG_CALLun(rv,copy));	\
491     SvREFCNT_dec(tmpRef);                   \
492   } } STMT_END
493 
494 /*
495 =for apidoc mU||LVRET
496 True if this op will be the return value of an lvalue subroutine
497 
498 =cut */
499 #define LVRET ((PL_op->op_private & OPpMAYBE_LVSUB) && is_lvalue_sub())
500 
501 /*
502  * Local variables:
503  * c-indentation-style: bsd
504  * c-basic-offset: 4
505  * indent-tabs-mode: t
506  * End:
507  *
508  * ex: set ts=8 sts=4 sw=4 noet:
509  */
510