X-Git-Url: https://perl5.git.perl.org/perl5.git/blobdiff_plain/748a93069b3d16374a9859d1456065dd3ae11394..6124d23f33100dc3c406774873984a1b51f6ab02:/pp.h

diff --git a/pp.h b/pp.h
index 9f80c29..1d9a933 100644
--- a/pp.h
+++ b/pp.h
@@ -1,143 +1,325 @@
 /*    pp.h
  *
- *    Copyright (c) 1991-1994, Larry Wall
+ *    Copyright (c) 1991-2001, Larry Wall
  *
  *    You may distribute under the terms of either the GNU General Public
  *    License or the Artistic License, as specified in the README file.
  *
  */
 
+#ifdef USE_5005THREADS
+#define ARGS thr
+#define dARGS struct perl_thread *thr;
+#else
 #define ARGS
-#define ARGSproto void
 #define dARGS
-#define PP(s) OP* s(ARGS) dARGS
+#endif /* USE_5005THREADS */
+
+#define PP(s) OP * Perl_##s(pTHX)
+
+/*
+=for apidoc AmU||SP
+Stack pointer.  This is usually handled by C<xsubpp>.  See C<dSP> and
+C<SPAGAIN>.
+
+=for apidoc AmU||MARK
+Stack marker variable for the XSUB.  See C<dMARK>.
+
+=for apidoc Ams||PUSHMARK
+Opening bracket for arguments on a callback.  See C<PUTBACK> and
+L<perlcall>.
+
+=for apidoc Ams||dSP
+Declares a local copy of perl's stack pointer for the XSUB, available via
+the C<SP> macro.  See C<SP>.
+
+=for apidoc ms||djSP
+
+Declare Just C<SP>. This is actually identical to C<dSP>, and declares
+a local copy of perl's stack pointer, available via the C<SP> macro.
+See C<SP>.  (Available for backward source code compatibility with the
+old (Perl 5.005) thread model.)
+
+=for apidoc Ams||dMARK
+Declare a stack marker variable, C<mark>, for the XSUB.  See C<MARK> and
+C<dORIGMARK>.
+
+=for apidoc Ams||dORIGMARK
+Saves the original stack mark for the XSUB.  See C<ORIGMARK>.
+
+=for apidoc AmU||ORIGMARK
+The original stack mark for the XSUB.  See C<dORIGMARK>.
+
+=for apidoc Ams||SPAGAIN
+Refetch the stack pointer.  Used after a callback.  See L<perlcall>.
 
+=cut */
+
+#undef SP /* Solaris 2.7 i386 has this in /usr/include/sys/reg.h */
 #define SP sp
 #define MARK mark
 #define TARG targ
 
-#define PUSHMARK(p) if (++markstack_ptr == markstack_max)	\
+#define PUSHMARK(p) if (++PL_markstack_ptr == PL_markstack_max)	\
 			markstack_grow();			\
-		    *markstack_ptr = (p) - stack_base
+		    *PL_markstack_ptr = (p) - PL_stack_base
 
-#define TOPMARK		(*markstack_ptr)
-#define POPMARK		(*markstack_ptr--)
+#define TOPMARK		(*PL_markstack_ptr)
+#define POPMARK		(*PL_markstack_ptr--)
 
-#define dSP		register SV **sp = stack_sp
-#define dMARK		register SV **mark = stack_base + POPMARK
-#define dORIGMARK	I32 origmark = mark - stack_base
-#define SETORIGMARK	origmark = mark - stack_base
-#define ORIGMARK	(stack_base + origmark)
+#define dSP		register SV **sp = PL_stack_sp
+#define djSP		dSP
+#define dMARK		register SV **mark = PL_stack_base + POPMARK
+#define dORIGMARK	I32 origmark = mark - PL_stack_base
+#define SETORIGMARK	origmark = mark - PL_stack_base
+#define ORIGMARK	(PL_stack_base + origmark)
 
-#define SPAGAIN		sp = stack_sp
-#define MSPAGAIN	sp = stack_sp; mark = ORIGMARK
+#define SPAGAIN		sp = PL_stack_sp
+#define MSPAGAIN	sp = PL_stack_sp; mark = ORIGMARK
 
-#define GETTARGETSTACKED targ = (op->op_flags & OPf_STACKED ? POPs : PAD_SV(op->op_targ))
+#define GETTARGETSTACKED targ = (PL_op->op_flags & OPf_STACKED ? POPs : PAD_SV(PL_op->op_targ))
 #define dTARGETSTACKED SV * GETTARGETSTACKED
 
-#define GETTARGET targ = PAD_SV(op->op_targ)
+#define GETTARGET targ = PAD_SV(PL_op->op_targ)
 #define dTARGET SV * GETTARGET
 
-#define GETATARGET targ = (op->op_flags & OPf_STACKED ? sp[-1] : PAD_SV(op->op_targ))
+#define GETATARGET targ = (PL_op->op_flags & OPf_STACKED ? sp[-1] : PAD_SV(PL_op->op_targ))
 #define dATARGET SV * GETATARGET
 
 #define dTARG SV *targ
 
-#define NORMAL op->op_next
-#define DIE return die
+#define NORMAL PL_op->op_next
+#define DIE return Perl_die
+
+/*
+=for apidoc Ams||PUTBACK
+Closing bracket for XSUB arguments.  This is usually handled by C<xsubpp>.
+See C<PUSHMARK> and L<perlcall> for other uses.
+
+=for apidoc Amn|SV*|POPs
+Pops an SV off the stack.
+
+=for apidoc Amn|char*|POPp
+Pops a string off the stack. Deprecated. New code should provide
+a STRLEN n_a and use POPpx.
+
+=for apidoc Amn|char*|POPpx
+Pops a string off the stack.
+Requires a variable STRLEN n_a in scope.
+
+=for apidoc Amn|char*|POPpbytex
+Pops a string off the stack which must consist of bytes i.e. characters < 256.
+Requires a variable STRLEN n_a in scope.
 
-#define PUTBACK		stack_sp = sp
+=for apidoc Amn|NV|POPn
+Pops a double off the stack.
+
+=for apidoc Amn|IV|POPi
+Pops an integer off the stack.
+
+=for apidoc Amn|long|POPl
+Pops a long off the stack.
+
+=cut
+*/
+
+#define PUTBACK		PL_stack_sp = sp
 #define RETURN		return PUTBACK, NORMAL
 #define RETURNOP(o)	return PUTBACK, o
 #define RETURNX(x)	return x, PUTBACK, NORMAL
 
 #define POPs		(*sp--)
-#define POPp		(SvPVx(POPs, na))
+#define POPp		(SvPVx(POPs, PL_na))		/* deprecated */
+#define POPpx		(SvPVx(POPs, n_a))
+#define POPpbytex	(SvPVbytex(POPs, n_a))
 #define POPn		(SvNVx(POPs))
 #define POPi		((IV)SvIVx(POPs))
+#define POPu		((UV)SvUVx(POPs))
 #define POPl		((long)SvIVx(POPs))
+#define POPul		((unsigned long)SvIVx(POPs))
+#ifdef HAS_QUAD
+#define POPq		((Quad_t)SvIVx(POPs))
+#define POPuq		((Uquad_t)SvUVx(POPs))
+#endif
 
 #define TOPs		(*sp)
-#define TOPp		(SvPV(TOPs, na))
+#define TOPm1s		(*(sp-1))
+#define TOPp1s		(*(sp+1))
+#define TOPp		(SvPV(TOPs, PL_na))		/* deprecated */
+#define TOPpx		(SvPV(TOPs, n_a))
 #define TOPn		(SvNV(TOPs))
 #define TOPi		((IV)SvIV(TOPs))
+#define TOPu		((UV)SvUV(TOPs))
 #define TOPl		((long)SvIV(TOPs))
+#define TOPul		((unsigned long)SvUV(TOPs))
+#ifdef HAS_QUAD
+#define TOPq		((Quad_t)SvIV(TOPs))
+#define TOPuq		((Uquad_t)SvUV(TOPs))
+#endif
 
 /* Go to some pains in the rare event that we must extend the stack. */
-#define EXTEND(p,n)	do { if (stack_max - p < (n)) {		  	    \
-			    sp = stack_grow(sp,p, (int) (n));		    \
-			} } while (0)
 
-/* Same thing, but update mark register too. */
-#define MEXTEND(p,n)	do {if (stack_max - p < (n)) {			    \
-			    int markoff = mark - stack_base;		    \
-			    sp = stack_grow(sp,p,(int) (n));		    \
-			    mark = stack_base + markoff;		    \
-			} } while (0)
+/*
+=for apidoc Am|void|EXTEND|SP|int nitems
+Used to extend the argument stack for an XSUB's return values. Once
+used, guarantees that there is room for at least C<nitems> to be pushed
+onto the stack.
 
-#define PUSHs(s)	(*++sp = (s))
-#define PUSHTARG	do { SvSETMAGIC(TARG); PUSHs(TARG); } while (0)
-#define PUSHp(p,l)	do { sv_setpvn(TARG, (p), (l)); PUSHTARG; } while (0)
-#define PUSHn(n)	do { sv_setnv(TARG, (double)(n)); PUSHTARG; } while (0)
-#define PUSHi(i)	do { sv_setiv(TARG, (IV)(i)); PUSHTARG; } while (0)
+=for apidoc Am|void|PUSHs|SV* sv
+Push an SV onto the stack.  The stack must have room for this element.
+Does not handle 'set' magic.  See C<XPUSHs>.
 
-#define XPUSHs(s)	do { EXTEND(sp,1); (*++sp = (s)); } while (0)
-#define XPUSHTARG	do { SvSETMAGIC(TARG); XPUSHs(TARG); } while (0)
-#define XPUSHp(p,l)	do { sv_setpvn(TARG, (p), (l)); XPUSHTARG; } while (0)
-#define XPUSHn(n)	do { sv_setnv(TARG, (double)(n)); XPUSHTARG; } while (0)
-#define XPUSHi(i)	do { sv_setiv(TARG, (IV)(i)); XPUSHTARG; } while (0)
+=for apidoc Am|void|PUSHp|char* str|STRLEN len
+Push a string onto the stack.  The stack must have room for this element.
+The C<len> indicates the length of the string.  Handles 'set' magic.  See
+C<XPUSHp>.
 
-#define SETs(s)		(*sp = s)
-#define SETTARG		do { SvSETMAGIC(TARG); SETs(TARG); } while (0)
-#define SETp(p,l)	do { sv_setpvn(TARG, (p), (l)); SETTARG; } while (0)
-#define SETn(n)		do { sv_setnv(TARG, (double)(n)); SETTARG; } while (0)
-#define SETi(i)		do { sv_setiv(TARG, (IV)(i)); SETTARG; } while (0)
+=for apidoc Am|void|PUSHn|NV nv
+Push a double onto the stack.  The stack must have room for this element.
+Handles 'set' magic.  See C<XPUSHn>.
 
-#ifdef OVERLOAD
-#define SETsv(sv)	do { sv_setsv(TARG, (sv)); SETTARG; } while (0)
-#endif /* OVERLOAD */
+=for apidoc Am|void|PUSHi|IV iv
+Push an integer onto the stack.  The stack must have room for this element.
+Handles 'set' magic.  See C<XPUSHi>.
 
-#define dTOPss		SV *sv = TOPs
-#define dPOPss		SV *sv = POPs
-#define dTOPnv		double value = TOPn
-#define dPOPnv		double value = POPn
-#define dTOPiv		IV value = TOPi
-#define dPOPiv		IV value = POPi
+=for apidoc Am|void|PUSHu|UV uv
+Push an unsigned integer onto the stack.  The stack must have room for this
+element.  See C<XPUSHu>.
 
-#define dPOPPOPssrl	SV *right = POPs; SV *left = POPs
-#define dPOPPOPnnrl	double right = POPn; double left = POPn
-#define dPOPPOPiirl	IV right = POPi; IV left = POPi
+=for apidoc Am|void|XPUSHs|SV* sv
+Push an SV onto the stack, extending the stack if necessary.  Does not
+handle 'set' magic.  See C<PUSHs>.
 
-#define dPOPTOPssrl	SV *right = POPs; SV *left = TOPs
-#define dPOPTOPnnrl	double right = POPn; double left = TOPn
-#define dPOPTOPiirl	IV right = POPi; IV left = TOPi
+=for apidoc Am|void|XPUSHp|char* str|STRLEN len
+Push a string onto the stack, extending the stack if necessary.  The C<len>
+indicates the length of the string.  Handles 'set' magic.  See
+C<PUSHp>.
 
-#define RETPUSHYES	RETURNX(PUSHs(&sv_yes))
-#define RETPUSHNO	RETURNX(PUSHs(&sv_no))
-#define RETPUSHUNDEF	RETURNX(PUSHs(&sv_undef))
+=for apidoc Am|void|XPUSHn|NV nv
+Push a double onto the stack, extending the stack if necessary.  Handles
+'set' magic.  See C<PUSHn>.
 
-#define RETSETYES	RETURNX(SETs(&sv_yes))
-#define RETSETNO	RETURNX(SETs(&sv_no))
-#define RETSETUNDEF	RETURNX(SETs(&sv_undef))
+=for apidoc Am|void|XPUSHi|IV iv
+Push an integer onto the stack, extending the stack if necessary.  Handles
+'set' magic. See C<PUSHi>.
+
+=for apidoc Am|void|XPUSHu|UV uv
+Push an unsigned integer onto the stack, extending the stack if necessary.
+See C<PUSHu>.
+
+=cut
+*/
+
+#define EXTEND(p,n)	STMT_START { if (PL_stack_max - p < (n)) {		\
+			    sp = stack_grow(sp,p, (int) (n));		\
+			} } STMT_END
+
+/* Same thing, but update mark register too. */
+#define MEXTEND(p,n)	STMT_START {if (PL_stack_max - p < (n)) {		\
+			    int markoff = mark - PL_stack_base;		\
+			    sp = stack_grow(sp,p,(int) (n));		\
+			    mark = PL_stack_base + markoff;		\
+			} } STMT_END
 
-#define ARGTARG		op->op_targ
-#define MAXARG		op->op_private
+#define PUSHs(s)	(*++sp = (s))
+#define PUSHTARG	STMT_START { SvSETMAGIC(TARG); PUSHs(TARG); } STMT_END
+#define PUSHp(p,l)	STMT_START { sv_setpvn(TARG, (p), (l)); PUSHTARG; } STMT_END
+#define PUSHn(n)	STMT_START { sv_setnv(TARG, (NV)(n)); PUSHTARG; } STMT_END
+#define PUSHi(i)	STMT_START { sv_setiv(TARG, (IV)(i)); PUSHTARG; } STMT_END
+#define PUSHu(u)	STMT_START { sv_setuv(TARG, (UV)(u)); PUSHTARG; } STMT_END
+
+#define XPUSHs(s)	STMT_START { EXTEND(sp,1); (*++sp = (s)); } STMT_END
+#define XPUSHTARG	STMT_START { SvSETMAGIC(TARG); XPUSHs(TARG); } STMT_END
+#define XPUSHp(p,l)	STMT_START { sv_setpvn(TARG, (p), (l)); XPUSHTARG; } STMT_END
+#define XPUSHn(n)	STMT_START { sv_setnv(TARG, (NV)(n)); XPUSHTARG; } STMT_END
+#define XPUSHi(i)	STMT_START { sv_setiv(TARG, (IV)(i)); XPUSHTARG; } STMT_END
+#define XPUSHu(u)	STMT_START { sv_setuv(TARG, (UV)(u)); XPUSHTARG; } STMT_END
+#define XPUSHundef	STMT_START { SvOK_off(TARG); XPUSHs(TARG); } STMT_END
 
-#define SWITCHSTACK(f,t)	AvFILL(f) = sp - stack_base;		\
-				stack_base = AvARRAY(t);		\
-				stack_max = stack_base + AvMAX(t);	\
-				sp = stack_sp = stack_base + AvFILL(t);	\
-				stack = t;
+#define SETs(s)		(*sp = s)
+#define SETTARG		STMT_START { SvSETMAGIC(TARG); SETs(TARG); } STMT_END
+#define SETp(p,l)	STMT_START { sv_setpvn(TARG, (p), (l)); SETTARG; } STMT_END
+#define SETn(n)		STMT_START { sv_setnv(TARG, (NV)(n)); SETTARG; } STMT_END
+#define SETi(i)		STMT_START { sv_setiv(TARG, (IV)(i)); SETTARG; } STMT_END
+#define SETu(u)		STMT_START { sv_setuv(TARG, (UV)(u)); SETTARG; } STMT_END
 
-#ifdef OVERLOAD
+#define dTOPss		SV *sv = TOPs
+#define dPOPss		SV *sv = POPs
+#define dTOPnv		NV value = TOPn
+#define dPOPnv		NV value = POPn
+#define dTOPiv		IV value = TOPi
+#define dPOPiv		IV value = POPi
+#define dTOPuv		UV value = TOPu
+#define dPOPuv		UV value = POPu
+#ifdef HAS_QUAD
+#define dTOPqv		Quad_t value = TOPu
+#define dPOPqv		Quad_t value = POPu
+#define dTOPuqv		Uquad_t value = TOPuq
+#define dPOPuqv		Uquad_t value = POPuq
+#endif
+
+#define dPOPXssrl(X)	SV *right = POPs; SV *left = CAT2(X,s)
+#define dPOPXnnrl(X)	NV right = POPn; NV left = CAT2(X,n)
+#define dPOPXiirl(X)	IV right = POPi; IV left = CAT2(X,i)
+
+#define USE_LEFT(sv) \
+	(SvOK(sv) || SvGMAGICAL(sv) || !(PL_op->op_flags & OPf_STACKED))
+#define dPOPXnnrl_ul(X)	\
+    NV right = POPn;				\
+    SV *leftsv = CAT2(X,s);				\
+    NV left = USE_LEFT(leftsv) ? SvNV(leftsv) : 0.0
+#define dPOPXiirl_ul(X) \
+    IV right = POPi;					\
+    SV *leftsv = CAT2(X,s);				\
+    IV left = USE_LEFT(leftsv) ? SvIV(leftsv) : 0
+
+#define dPOPPOPssrl	dPOPXssrl(POP)
+#define dPOPPOPnnrl	dPOPXnnrl(POP)
+#define dPOPPOPnnrl_ul	dPOPXnnrl_ul(POP)
+#define dPOPPOPiirl	dPOPXiirl(POP)
+#define dPOPPOPiirl_ul	dPOPXiirl_ul(POP)
+
+#define dPOPTOPssrl	dPOPXssrl(TOP)
+#define dPOPTOPnnrl	dPOPXnnrl(TOP)
+#define dPOPTOPnnrl_ul	dPOPXnnrl_ul(TOP)
+#define dPOPTOPiirl	dPOPXiirl(TOP)
+#define dPOPTOPiirl_ul	dPOPXiirl_ul(TOP)
+
+#define RETPUSHYES	RETURNX(PUSHs(&PL_sv_yes))
+#define RETPUSHNO	RETURNX(PUSHs(&PL_sv_no))
+#define RETPUSHUNDEF	RETURNX(PUSHs(&PL_sv_undef))
+
+#define RETSETYES	RETURNX(SETs(&PL_sv_yes))
+#define RETSETNO	RETURNX(SETs(&PL_sv_no))
+#define RETSETUNDEF	RETURNX(SETs(&PL_sv_undef))
+
+#define ARGTARG		PL_op->op_targ
+
+    /* See OPpTARGET_MY: */
+#define MAXARG		(PL_op->op_private & 15)
+
+#define SWITCHSTACK(f,t) \
+    STMT_START {							\
+	AvFILLp(f) = sp - PL_stack_base;				\
+	PL_stack_base = AvARRAY(t);					\
+	PL_stack_max = PL_stack_base + AvMAX(t);			\
+	sp = PL_stack_sp = PL_stack_base + AvFILLp(t);			\
+	PL_curstack = t;						\
+    } STMT_END
+
+#define EXTEND_MORTAL(n) \
+    STMT_START {							\
+	if (PL_tmps_ix + (n) >= PL_tmps_max)				\
+	    tmps_grow(n);						\
+    } STMT_END
 
 #define AMGf_noright	1
 #define AMGf_noleft	2
 #define AMGf_assign	4
 #define AMGf_unary	8
 
-#define tryAMAGICbinW(meth,assign,set) do { \
-          if (amagic_generation) { \
+#define tryAMAGICbinW(meth,assign,set) STMT_START { \
+          if (PL_amagic_generation) { \
 	    SV* tmpsv; \
 	    SV* right= *(sp); SV* left= *(sp-1);\
 	    if ((SvAMAGIC(left)||SvAMAGIC(right))&&\
@@ -148,46 +330,73 @@
 	       SPAGAIN;	\
 	       (void)POPs; set(tmpsv); RETURN; } \
 	  } \
-	} while (0)
+	} STMT_END
 
 #define tryAMAGICbin(meth,assign) tryAMAGICbinW(meth,assign,SETsv)
 #define tryAMAGICbinSET(meth,assign) tryAMAGICbinW(meth,assign,SETs)
 
-#define AMG_CALLun(sv,meth) amagic_call(sv,&sv_undef,  \
+#define AMG_CALLun(sv,meth) amagic_call(sv,&PL_sv_undef,  \
 					CAT2(meth,_amg),AMGf_noright | AMGf_unary)
 #define AMG_CALLbinL(left,right,meth) \
             amagic_call(left,right,CAT2(meth,_amg),AMGf_noright)
 
-#define tryAMAGICunW(meth,set) do { \
-          if (amagic_generation) { \
+#define tryAMAGICunW(meth,set,shift,ret) STMT_START { \
+          if (PL_amagic_generation) { \
 	    SV* tmpsv; \
-	    SV* arg= *(sp); \
+	    SV* arg= sp[shift]; \
+          if(0) goto am_again;  /* shut up unused warning */ \
+	  am_again: \
 	    if ((SvAMAGIC(arg))&&\
 		(tmpsv=AMG_CALLun(arg,meth))) {\
-	       SPAGAIN;	\
-	       set(tmpsv); RETURN; } \
+	       SPAGAIN; if (shift) sp += shift; \
+	       set(tmpsv); ret; } \
 	  } \
-	} while (0)
-
-#define tryAMAGICun(meth) tryAMAGICunW(meth,SETsv)
-#define tryAMAGICunSET(meth) tryAMAGICunW(meth,SETs)
-
-#define opASSIGN (op->op_flags & OPf_STACKED)
+	} STMT_END
+
+#define FORCE_SETs(sv) STMT_START { sv_setsv(TARG, (sv)); SETTARG; } STMT_END
+
+#define tryAMAGICun(meth)	tryAMAGICunW(meth,SETsvUN,0,RETURN)
+#define tryAMAGICunSET(meth)	tryAMAGICunW(meth,SETs,0,RETURN)
+#define tryAMAGICunTARGET(meth, shift)					\
+	{ dSP; sp--; 	/* get TARGET from below PL_stack_sp */		\
+	    { dTARGETSTACKED; 						\
+		{ dSP; tryAMAGICunW(meth,FORCE_SETs,shift,RETURN);}}}
+
+#define setAGAIN(ref) sv = ref;							\
+  if (!SvROK(ref))								\
+      Perl_croak(aTHX_ "Overloaded dereference did not return a reference");	\
+  if (ref != arg && SvRV(ref) != SvRV(arg)) {					\
+      arg = ref;								\
+      goto am_again;								\
+  }
+
+#define tryAMAGICunDEREF(meth) tryAMAGICunW(meth,setAGAIN,0,(void)0)
+
+#define opASSIGN (PL_op->op_flags & OPf_STACKED)
+#define SETsv(sv)	STMT_START {					\
+		if (opASSIGN || (SvFLAGS(TARG) & SVs_PADMY))		\
+		   { sv_setsv(TARG, (sv)); SETTARG; }			\
+		else SETs(sv); } STMT_END
+
+#define SETsvUN(sv)	STMT_START {					\
+		if (SvFLAGS(TARG) & SVs_PADMY)		\
+		   { sv_setsv(TARG, (sv)); SETTARG; }			\
+		else SETs(sv); } STMT_END
 
 /* newSVsv does not behave as advertised, so we copy missing
  * information by hand */
 
-
-#define RvDEEPCP(rv) do { SV* ref=SvRV(rv);      \
-  if (SvREFCNT(ref)>1) {                 \
-    SvREFCNT_dec(ref);                   \
+/* SV* ref causes confusion with the member variable
+   changed SV* ref to SV* tmpRef */
+#define RvDEEPCP(rv) STMT_START { SV* tmpRef=SvRV(rv);      \
+  if (SvREFCNT(tmpRef)>1) {                 \
+    SvREFCNT_dec(tmpRef);                   \
     SvRV(rv)=AMG_CALLun(rv,copy);        \
-  } } while (0)
-#else
+  } } STMT_END
 
-#define tryAMAGICbin(a,b)
-#define tryAMAGICbinSET(a,b)
-#define tryAMAGICun(a)
-#define tryAMAGICunSET(a)
+/*
+=for apidoc mU||LVRET
+True if this op will be the return value of an lvalue subroutine
 
-#endif /* OVERLOAD */
+=cut */
+#define LVRET ((PL_op->op_private & OPpMAYBE_LVSUB) && is_lvalue_sub())