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[perl #130001] h2xs: avoid infinite loop for enums
[perl5.git] / pp_hot.c
CommitLineData
a0d0e21e
LW
1/* pp_hot.c
2 *
1129b882
NC
3 * Copyright (C) 1991, 1992, 1993, 1994, 1995, 1996, 1997, 1998, 1999, 2000,
4 * 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008 by Larry Wall and others
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LW
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 * Then he heard Merry change the note, and up went the Horn-cry of Buckland,
13 * shaking the air.
14 *
4ac71550
TC
15 * Awake! Awake! Fear, Fire, Foes! Awake!
16 * Fire, Foes! Awake!
17 *
18 * [p.1007 of _The Lord of the Rings_, VI/viii: "The Scouring of the Shire"]
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LW
19 */
20
166f8a29
DM
21/* This file contains 'hot' pp ("push/pop") functions that
22 * execute the opcodes that make up a perl program. A typical pp function
23 * expects to find its arguments on the stack, and usually pushes its
24 * results onto the stack, hence the 'pp' terminology. Each OP structure
25 * contains a pointer to the relevant pp_foo() function.
26 *
27 * By 'hot', we mean common ops whose execution speed is critical.
28 * By gathering them together into a single file, we encourage
29 * CPU cache hits on hot code. Also it could be taken as a warning not to
30 * change any code in this file unless you're sure it won't affect
31 * performance.
32 */
33
a0d0e21e 34#include "EXTERN.h"
864dbfa3 35#define PERL_IN_PP_HOT_C
a0d0e21e
LW
36#include "perl.h"
37
38/* Hot code. */
39
40PP(pp_const)
41{
39644a26 42 dSP;
996c9baa 43 XPUSHs(cSVOP_sv);
a0d0e21e
LW
44 RETURN;
45}
46
47PP(pp_nextstate)
48{
533c011a 49 PL_curcop = (COP*)PL_op;
a0d0e21e 50 TAINT_NOT; /* Each statement is presumed innocent */
4ebe6e95 51 PL_stack_sp = PL_stack_base + CX_CUR()->blk_oldsp;
a0d0e21e 52 FREETMPS;
f410a211 53 PERL_ASYNC_CHECK();
a0d0e21e
LW
54 return NORMAL;
55}
56
57PP(pp_gvsv)
58{
39644a26 59 dSP;
924508f0 60 EXTEND(SP,1);
5d9574c1 61 if (UNLIKELY(PL_op->op_private & OPpLVAL_INTRO))
1d7c1841 62 PUSHs(save_scalar(cGVOP_gv));
a0d0e21e 63 else
c69033f2 64 PUSHs(GvSVn(cGVOP_gv));
a0d0e21e
LW
65 RETURN;
66}
67
b1c05ba5
DM
68
69/* also used for: pp_lineseq() pp_regcmaybe() pp_scalar() pp_scope() */
70
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LW
71PP(pp_null)
72{
73 return NORMAL;
74}
75
3dd9d4e4
FC
76/* This is sometimes called directly by pp_coreargs, pp_grepstart and
77 amagic_call. */
a0d0e21e
LW
78PP(pp_pushmark)
79{
3280af22 80 PUSHMARK(PL_stack_sp);
a0d0e21e
LW
81 return NORMAL;
82}
83
84PP(pp_stringify)
85{
20b7effb 86 dSP; dTARGET;
4cc783ef
DD
87 SV * const sv = TOPs;
88 SETs(TARG);
89 sv_copypv(TARG, sv);
90 SvSETMAGIC(TARG);
91 /* no PUTBACK, SETs doesn't inc/dec SP */
92 return NORMAL;
a0d0e21e
LW
93}
94
95PP(pp_gv)
96{
20b7effb 97 dSP;
ad64d0ec 98 XPUSHs(MUTABLE_SV(cGVOP_gv));
a0d0e21e
LW
99 RETURN;
100}
101
b1c05ba5
DM
102
103/* also used for: pp_andassign() */
104
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LW
105PP(pp_and)
106{
f410a211 107 PERL_ASYNC_CHECK();
4cc783ef
DD
108 {
109 /* SP is not used to remove a variable that is saved across the
110 sv_2bool_flags call in SvTRUE_NN, if a RISC/CISC or low/high machine
111 register or load/store vs direct mem ops macro is introduced, this
112 should be a define block between direct PL_stack_sp and dSP operations,
113 presently, using PL_stack_sp is bias towards CISC cpus */
114 SV * const sv = *PL_stack_sp;
115 if (!SvTRUE_NN(sv))
116 return NORMAL;
117 else {
118 if (PL_op->op_type == OP_AND)
119 --PL_stack_sp;
120 return cLOGOP->op_other;
121 }
a0d0e21e
LW
122 }
123}
124
125PP(pp_sassign)
126{
20b7effb 127 dSP;
3e75a3c4
RU
128 /* sassign keeps its args in the optree traditionally backwards.
129 So we pop them differently.
130 */
131 SV *left = POPs; SV *right = TOPs;
748a9306 132
354eabfa 133 if (PL_op->op_private & OPpASSIGN_BACKWARDS) { /* {or,and,dor}assign */
0bd48802
AL
134 SV * const temp = left;
135 left = right; right = temp;
a0d0e21e 136 }
d48c660d
DM
137 assert(TAINTING_get || !TAINT_get);
138 if (UNLIKELY(TAINT_get) && !SvTAINTED(right))
a0d0e21e 139 TAINT_NOT;
5d9574c1
DM
140 if (UNLIKELY(PL_op->op_private & OPpASSIGN_CV_TO_GV)) {
141 /* *foo =\&bar */
3e75a3c4 142 SV * const cv = SvRV(right);
e26df76a 143 const U32 cv_type = SvTYPE(cv);
3e75a3c4 144 const bool is_gv = isGV_with_GP(left);
6136c704 145 const bool got_coderef = cv_type == SVt_PVCV || cv_type == SVt_PVFM;
e26df76a
NC
146
147 if (!got_coderef) {
148 assert(SvROK(cv));
149 }
150
3e75a3c4
RU
151 /* Can do the optimisation if left (LVALUE) is not a typeglob,
152 right (RVALUE) is a reference to something, and we're in void
e26df76a 153 context. */
13be902c 154 if (!got_coderef && !is_gv && GIMME_V == G_VOID) {
e26df76a 155 /* Is the target symbol table currently empty? */
3e75a3c4 156 GV * const gv = gv_fetchsv_nomg(left, GV_NOINIT, SVt_PVGV);
bb112e5a 157 if (SvTYPE(gv) != SVt_PVGV && !SvOK(gv)) {
e26df76a
NC
158 /* Good. Create a new proxy constant subroutine in the target.
159 The gv becomes a(nother) reference to the constant. */
160 SV *const value = SvRV(cv);
161
ad64d0ec 162 SvUPGRADE(MUTABLE_SV(gv), SVt_IV);
1ccdb730 163 SvPCS_IMPORTED_on(gv);
e26df76a 164 SvRV_set(gv, value);
b37c2d43 165 SvREFCNT_inc_simple_void(value);
3e75a3c4 166 SETs(left);
e26df76a
NC
167 RETURN;
168 }
169 }
170
171 /* Need to fix things up. */
13be902c 172 if (!is_gv) {
e26df76a 173 /* Need to fix GV. */
3e75a3c4 174 left = MUTABLE_SV(gv_fetchsv_nomg(left,GV_ADD, SVt_PVGV));
e26df76a
NC
175 }
176
177 if (!got_coderef) {
178 /* We've been returned a constant rather than a full subroutine,
179 but they expect a subroutine reference to apply. */
53a42478 180 if (SvROK(cv)) {
d343c3ef 181 ENTER_with_name("sassign_coderef");
53a42478
NC
182 SvREFCNT_inc_void(SvRV(cv));
183 /* newCONSTSUB takes a reference count on the passed in SV
184 from us. We set the name to NULL, otherwise we get into
185 all sorts of fun as the reference to our new sub is
186 donated to the GV that we're about to assign to.
187 */
3e75a3c4 188 SvRV_set(right, MUTABLE_SV(newCONSTSUB(GvSTASH(left), NULL,
ad64d0ec 189 SvRV(cv))));
fc2b2dca 190 SvREFCNT_dec_NN(cv);
d343c3ef 191 LEAVE_with_name("sassign_coderef");
53a42478
NC
192 } else {
193 /* What can happen for the corner case *{"BONK"} = \&{"BONK"};
194 is that
195 First: ops for \&{"BONK"}; return us the constant in the
196 symbol table
197 Second: ops for *{"BONK"} cause that symbol table entry
198 (and our reference to it) to be upgraded from RV
199 to typeblob)
200 Thirdly: We get here. cv is actually PVGV now, and its
201 GvCV() is actually the subroutine we're looking for
202
203 So change the reference so that it points to the subroutine
204 of that typeglob, as that's what they were after all along.
205 */
159b6efe 206 GV *const upgraded = MUTABLE_GV(cv);
53a42478
NC
207 CV *const source = GvCV(upgraded);
208
209 assert(source);
210 assert(CvFLAGS(source) & CVf_CONST);
211
0ad694a7 212 SvREFCNT_inc_simple_void_NN(source);
fc2b2dca 213 SvREFCNT_dec_NN(upgraded);
3e75a3c4 214 SvRV_set(right, MUTABLE_SV(source));
53a42478 215 }
e26df76a 216 }
53a42478 217
e26df76a 218 }
8fe85e3f 219 if (
5d9574c1 220 UNLIKELY(SvTEMP(left)) && !SvSMAGICAL(left) && SvREFCNT(left) == 1 &&
3e75a3c4 221 (!isGV_with_GP(left) || SvFAKE(left)) && ckWARN(WARN_MISC)
8fe85e3f
FC
222 )
223 Perl_warner(aTHX_
224 packWARN(WARN_MISC), "Useless assignment to a temporary"
225 );
3e75a3c4
RU
226 SvSetMagicSV(left, right);
227 SETs(left);
a0d0e21e
LW
228 RETURN;
229}
230
231PP(pp_cond_expr)
232{
20b7effb 233 dSP;
f410a211 234 PERL_ASYNC_CHECK();
a0d0e21e 235 if (SvTRUEx(POPs))
1a67a97c 236 RETURNOP(cLOGOP->op_other);
a0d0e21e 237 else
1a67a97c 238 RETURNOP(cLOGOP->op_next);
a0d0e21e
LW
239}
240
241PP(pp_unstack)
242{
f5319de9 243 PERL_CONTEXT *cx;
8f3964af 244 PERL_ASYNC_CHECK();
a0d0e21e 245 TAINT_NOT; /* Each statement is presumed innocent */
4ebe6e95 246 cx = CX_CUR();
f5319de9 247 PL_stack_sp = PL_stack_base + cx->blk_oldsp;
a0d0e21e 248 FREETMPS;
eae48c89 249 if (!(PL_op->op_flags & OPf_SPECIAL)) {
93661e56 250 assert(CxTYPE(cx) == CXt_BLOCK || CxTYPE_is_LOOP(cx));
dfe0f39b 251 CX_LEAVE_SCOPE(cx);
eae48c89 252 }
a0d0e21e
LW
253 return NORMAL;
254}
255
a0d0e21e
LW
256PP(pp_concat)
257{
20b7effb 258 dSP; dATARGET; tryAMAGICbin_MG(concat_amg, AMGf_assign);
748a9306
LW
259 {
260 dPOPTOPssrl;
8d6d96c1
HS
261 bool lbyte;
262 STRLEN rlen;
d4c19fe8 263 const char *rpv = NULL;
a6b599c7 264 bool rbyte = FALSE;
a9c4fd4e 265 bool rcopied = FALSE;
8d6d96c1 266
6f1401dc
DM
267 if (TARG == right && right != left) { /* $r = $l.$r */
268 rpv = SvPV_nomg_const(right, rlen);
c75ab21a 269 rbyte = !DO_UTF8(right);
59cd0e26 270 right = newSVpvn_flags(rpv, rlen, SVs_TEMP);
349d4f2f 271 rpv = SvPV_const(right, rlen); /* no point setting UTF-8 here */
db79b45b 272 rcopied = TRUE;
8d6d96c1 273 }
7889fe52 274
89734059 275 if (TARG != left) { /* not $l .= $r */
a9c4fd4e 276 STRLEN llen;
6f1401dc 277 const char* const lpv = SvPV_nomg_const(left, llen);
90f5826e 278 lbyte = !DO_UTF8(left);
8d6d96c1
HS
279 sv_setpvn(TARG, lpv, llen);
280 if (!lbyte)
281 SvUTF8_on(TARG);
282 else
283 SvUTF8_off(TARG);
284 }
18ea7bf2
SM
285 else { /* $l .= $r and left == TARG */
286 if (!SvOK(left)) {
51f69a24
AC
287 if ((left == right /* $l .= $l */
288 || (PL_op->op_private & OPpTARGET_MY)) /* $l = $l . $r */
289 && ckWARN(WARN_UNINITIALIZED)
290 )
291 report_uninit(left);
adf14ec6 292 SvPVCLEAR(left);
c75ab21a 293 }
18ea7bf2
SM
294 else {
295 SvPV_force_nomg_nolen(left);
296 }
583a5589 297 lbyte = !DO_UTF8(left);
90f5826e 298 if (IN_BYTES)
18ea7bf2 299 SvUTF8_off(left);
8d6d96c1 300 }
a12c0f56 301
c75ab21a 302 if (!rcopied) {
6f1401dc 303 rpv = SvPV_nomg_const(right, rlen);
c75ab21a
RH
304 rbyte = !DO_UTF8(right);
305 }
8d6d96c1
HS
306 if (lbyte != rbyte) {
307 if (lbyte)
308 sv_utf8_upgrade_nomg(TARG);
309 else {
db79b45b 310 if (!rcopied)
59cd0e26 311 right = newSVpvn_flags(rpv, rlen, SVs_TEMP);
8d6d96c1 312 sv_utf8_upgrade_nomg(right);
6f1401dc 313 rpv = SvPV_nomg_const(right, rlen);
69b47968 314 }
a0d0e21e 315 }
8d6d96c1 316 sv_catpvn_nomg(TARG, rpv, rlen);
43ebc500 317
a0d0e21e
LW
318 SETTARG;
319 RETURN;
748a9306 320 }
a0d0e21e
LW
321}
322
d5524600
DM
323/* push the elements of av onto the stack.
324 * XXX Note that padav has similar code but without the mg_get().
325 * I suspect that the mg_get is no longer needed, but while padav
326 * differs, it can't share this function */
327
f9ae8fb6 328STATIC void
d5524600
DM
329S_pushav(pTHX_ AV* const av)
330{
331 dSP;
c70927a6 332 const SSize_t maxarg = AvFILL(av) + 1;
d5524600 333 EXTEND(SP, maxarg);
5d9574c1 334 if (UNLIKELY(SvRMAGICAL(av))) {
c70927a6
FC
335 PADOFFSET i;
336 for (i=0; i < (PADOFFSET)maxarg; i++) {
d5524600
DM
337 SV ** const svp = av_fetch(av, i, FALSE);
338 /* See note in pp_helem, and bug id #27839 */
339 SP[i+1] = svp
340 ? SvGMAGICAL(*svp) ? (mg_get(*svp), *svp) : *svp
341 : &PL_sv_undef;
342 }
343 }
344 else {
c70927a6
FC
345 PADOFFSET i;
346 for (i=0; i < (PADOFFSET)maxarg; i++) {
ce0d59fd 347 SV * const sv = AvARRAY(av)[i];
5d9574c1 348 SP[i+1] = LIKELY(sv) ? sv : &PL_sv_undef;
ce0d59fd 349 }
d5524600
DM
350 }
351 SP += maxarg;
352 PUTBACK;
353}
354
355
a7fd8ef6
DM
356/* ($lex1,@lex2,...) or my ($lex1,@lex2,...) */
357
358PP(pp_padrange)
359{
20b7effb 360 dSP;
a7fd8ef6
DM
361 PADOFFSET base = PL_op->op_targ;
362 int count = (int)(PL_op->op_private) & OPpPADRANGE_COUNTMASK;
363 int i;
d5524600
DM
364 if (PL_op->op_flags & OPf_SPECIAL) {
365 /* fake the RHS of my ($x,$y,..) = @_ */
366 PUSHMARK(SP);
367 S_pushav(aTHX_ GvAVn(PL_defgv));
368 SPAGAIN;
369 }
370
a7fd8ef6
DM
371 /* note, this is only skipped for compile-time-known void cxt */
372 if ((PL_op->op_flags & OPf_WANT) != OPf_WANT_VOID) {
373 EXTEND(SP, count);
374 PUSHMARK(SP);
375 for (i = 0; i <count; i++)
376 *++SP = PAD_SV(base+i);
377 }
378 if (PL_op->op_private & OPpLVAL_INTRO) {
4e09461c
DM
379 SV **svp = &(PAD_SVl(base));
380 const UV payload = (UV)(
381 (base << (OPpPADRANGE_COUNTSHIFT + SAVE_TIGHT_SHIFT))
382 | (count << SAVE_TIGHT_SHIFT)
383 | SAVEt_CLEARPADRANGE);
6d59e610 384 STATIC_ASSERT_STMT(OPpPADRANGE_COUNTMASK + 1 == (1 << OPpPADRANGE_COUNTSHIFT));
d081a355
DM
385 assert((payload >> (OPpPADRANGE_COUNTSHIFT+SAVE_TIGHT_SHIFT))
386 == (Size_t)base);
a3444cc5
DM
387 {
388 dSS_ADD;
389 SS_ADD_UV(payload);
390 SS_ADD_END(1);
391 }
4e09461c 392
a7fd8ef6 393 for (i = 0; i <count; i++)
4e09461c 394 SvPADSTALE_off(*svp++); /* mark lexical as active */
a7fd8ef6
DM
395 }
396 RETURN;
397}
398
399
a0d0e21e
LW
400PP(pp_padsv)
401{
20b7effb 402 dSP;
6c28b496
DD
403 EXTEND(SP, 1);
404 {
405 OP * const op = PL_op;
406 /* access PL_curpad once */
407 SV ** const padentry = &(PAD_SVl(op->op_targ));
408 {
409 dTARG;
410 TARG = *padentry;
411 PUSHs(TARG);
412 PUTBACK; /* no pop/push after this, TOPs ok */
8ec5e241 413 }
6c28b496
DD
414 if (op->op_flags & OPf_MOD) {
415 if (op->op_private & OPpLVAL_INTRO)
416 if (!(op->op_private & OPpPAD_STATE))
417 save_clearsv(padentry);
418 if (op->op_private & OPpDEREF) {
8f90a16d
FC
419 /* TOPs is equivalent to TARG here. Using TOPs (SP) rather
420 than TARG reduces the scope of TARG, so it does not
421 span the call to save_clearsv, resulting in smaller
422 machine code. */
6c28b496
DD
423 TOPs = vivify_ref(TOPs, op->op_private & OPpDEREF);
424 }
425 }
426 return op->op_next;
4633a7c4 427 }
a0d0e21e
LW
428}
429
430PP(pp_readline)
431{
30901a8a
FC
432 dSP;
433 if (TOPs) {
434 SvGETMAGIC(TOPs);
fc99edcf 435 tryAMAGICunTARGETlist(iter_amg, 0);
30901a8a
FC
436 PL_last_in_gv = MUTABLE_GV(*PL_stack_sp--);
437 }
438 else PL_last_in_gv = PL_argvgv, PL_stack_sp--;
6e592b3a
BM
439 if (!isGV_with_GP(PL_last_in_gv)) {
440 if (SvROK(PL_last_in_gv) && isGV_with_GP(SvRV(PL_last_in_gv)))
159b6efe 441 PL_last_in_gv = MUTABLE_GV(SvRV(PL_last_in_gv));
8efb3254 442 else {
f5284f61 443 dSP;
ad64d0ec 444 XPUSHs(MUTABLE_SV(PL_last_in_gv));
f5284f61 445 PUTBACK;
897d3989 446 Perl_pp_rv2gv(aTHX);
159b6efe 447 PL_last_in_gv = MUTABLE_GV(*PL_stack_sp--);
84ee769f
FC
448 if (PL_last_in_gv == (GV *)&PL_sv_undef)
449 PL_last_in_gv = NULL;
450 else
451 assert(isGV_with_GP(PL_last_in_gv));
f5284f61
IZ
452 }
453 }
a0d0e21e
LW
454 return do_readline();
455}
456
457PP(pp_eq)
458{
20b7effb 459 dSP;
33efebe6
DM
460 SV *left, *right;
461
a42d0242 462 tryAMAGICbin_MG(eq_amg, AMGf_set|AMGf_numeric);
33efebe6
DM
463 right = POPs;
464 left = TOPs;
465 SETs(boolSV(
466 (SvIOK_notUV(left) && SvIOK_notUV(right))
467 ? (SvIVX(left) == SvIVX(right))
468 : ( do_ncmp(left, right) == 0)
469 ));
470 RETURN;
a0d0e21e
LW
471}
472
b1c05ba5 473
4c2c3128 474/* also used for: pp_i_preinc() */
b1c05ba5 475
a0d0e21e
LW
476PP(pp_preinc)
477{
4c2c3128
DM
478 SV *sv = *PL_stack_sp;
479
480 if (LIKELY(((sv->sv_flags &
481 (SVf_THINKFIRST|SVs_GMG|SVf_IVisUV|
482 SVf_IOK|SVf_NOK|SVf_POK|SVp_NOK|SVp_POK|SVf_ROK))
483 == SVf_IOK))
484 && SvIVX(sv) != IV_MAX)
485 {
486 SvIV_set(sv, SvIVX(sv) + 1);
487 }
488 else /* Do all the PERL_PRESERVE_IVUV and hard cases in sv_inc */
489 sv_inc(sv);
490 SvSETMAGIC(sv);
491 return NORMAL;
492}
493
494
495/* also used for: pp_i_predec() */
496
497PP(pp_predec)
498{
499 SV *sv = *PL_stack_sp;
500
501 if (LIKELY(((sv->sv_flags &
502 (SVf_THINKFIRST|SVs_GMG|SVf_IVisUV|
503 SVf_IOK|SVf_NOK|SVf_POK|SVp_NOK|SVp_POK|SVf_ROK))
504 == SVf_IOK))
505 && SvIVX(sv) != IV_MIN)
55497cff 506 {
4c2c3128 507 SvIV_set(sv, SvIVX(sv) - 1);
748a9306 508 }
4c2c3128
DM
509 else /* Do all the PERL_PRESERVE_IVUV and hard cases in sv_dec */
510 sv_dec(sv);
511 SvSETMAGIC(sv);
a0d0e21e
LW
512 return NORMAL;
513}
514
b1c05ba5
DM
515
516/* also used for: pp_orassign() */
517
a0d0e21e
LW
518PP(pp_or)
519{
20b7effb 520 dSP;
f410a211 521 PERL_ASYNC_CHECK();
a0d0e21e
LW
522 if (SvTRUE(TOPs))
523 RETURN;
524 else {
c960fc3b
SP
525 if (PL_op->op_type == OP_OR)
526 --SP;
a0d0e21e
LW
527 RETURNOP(cLOGOP->op_other);
528 }
529}
530
b1c05ba5
DM
531
532/* also used for: pp_dor() pp_dorassign() */
533
25a55bd7 534PP(pp_defined)
c963b151 535{
20b7effb 536 dSP;
eb578fdb 537 SV* sv;
6136c704 538 bool defined;
25a55bd7 539 const int op_type = PL_op->op_type;
ea5195b7 540 const bool is_dor = (op_type == OP_DOR || op_type == OP_DORASSIGN);
c963b151 541
6136c704 542 if (is_dor) {
f410a211 543 PERL_ASYNC_CHECK();
25a55bd7 544 sv = TOPs;
5d9574c1 545 if (UNLIKELY(!sv || !SvANY(sv))) {
2bd49cfc
NC
546 if (op_type == OP_DOR)
547 --SP;
25a55bd7
SP
548 RETURNOP(cLOGOP->op_other);
549 }
b7c44293
RGS
550 }
551 else {
552 /* OP_DEFINED */
25a55bd7 553 sv = POPs;
5d9574c1 554 if (UNLIKELY(!sv || !SvANY(sv)))
25a55bd7 555 RETPUSHNO;
b7c44293 556 }
25a55bd7 557
6136c704 558 defined = FALSE;
c963b151
BD
559 switch (SvTYPE(sv)) {
560 case SVt_PVAV:
561 if (AvMAX(sv) >= 0 || SvGMAGICAL(sv) || (SvRMAGICAL(sv) && mg_find(sv, PERL_MAGIC_tied)))
25a55bd7 562 defined = TRUE;
c963b151
BD
563 break;
564 case SVt_PVHV:
565 if (HvARRAY(sv) || SvGMAGICAL(sv) || (SvRMAGICAL(sv) && mg_find(sv, PERL_MAGIC_tied)))
25a55bd7 566 defined = TRUE;
c963b151
BD
567 break;
568 case SVt_PVCV:
569 if (CvROOT(sv) || CvXSUB(sv))
25a55bd7 570 defined = TRUE;
c963b151
BD
571 break;
572 default:
5b295bef 573 SvGETMAGIC(sv);
c963b151 574 if (SvOK(sv))
25a55bd7 575 defined = TRUE;
6136c704 576 break;
c963b151 577 }
6136c704
AL
578
579 if (is_dor) {
c960fc3b
SP
580 if(defined)
581 RETURN;
582 if(op_type == OP_DOR)
583 --SP;
25a55bd7 584 RETURNOP(cLOGOP->op_other);
25a55bd7 585 }
d9aa96a4
SP
586 /* assuming OP_DEFINED */
587 if(defined)
588 RETPUSHYES;
589 RETPUSHNO;
c963b151
BD
590}
591
230ee21f
DM
592
593
a0d0e21e
LW
594PP(pp_add)
595{
20b7effb 596 dSP; dATARGET; bool useleft; SV *svl, *svr;
230ee21f 597
6f1401dc
DM
598 tryAMAGICbin_MG(add_amg, AMGf_assign|AMGf_numeric);
599 svr = TOPs;
600 svl = TOPm1s;
601
28e5dec8 602#ifdef PERL_PRESERVE_IVUV
230ee21f
DM
603
604 /* special-case some simple common cases */
605 if (!((svl->sv_flags|svr->sv_flags) & (SVf_IVisUV|SVs_GMG))) {
606 IV il, ir;
607 U32 flags = (svl->sv_flags & svr->sv_flags);
608 if (flags & SVf_IOK) {
609 /* both args are simple IVs */
610 UV topl, topr;
611 il = SvIVX(svl);
612 ir = SvIVX(svr);
613 do_iv:
614 topl = ((UV)il) >> (UVSIZE * 8 - 2);
615 topr = ((UV)ir) >> (UVSIZE * 8 - 2);
616
617 /* if both are in a range that can't under/overflow, do a
618 * simple integer add: if the top of both numbers
619 * are 00 or 11, then it's safe */
620 if (!( ((topl+1) | (topr+1)) & 2)) {
621 SP--;
622 TARGi(il + ir, 0); /* args not GMG, so can't be tainted */
623 SETs(TARG);
624 RETURN;
625 }
626 goto generic;
627 }
628 else if (flags & SVf_NOK) {
629 /* both args are NVs */
630 NV nl = SvNVX(svl);
631 NV nr = SvNVX(svr);
632
3336af0b
DD
633 if (
634#if defined(NAN_COMPARE_BROKEN) && defined(Perl_isnan)
635 !Perl_isnan(nl) && nl == (NV)(il = (IV)nl)
636 && !Perl_isnan(nr) && nr == (NV)(ir = (IV)nr)
637#else
638 nl == (NV)(il = (IV)nl) && nr == (NV)(ir = (IV)nr)
639#endif
640 )
230ee21f
DM
641 /* nothing was lost by converting to IVs */
642 goto do_iv;
643 SP--;
644 TARGn(nl + nr, 0); /* args not GMG, so can't be tainted */
645 SETs(TARG);
646 RETURN;
647 }
648 }
649
650 generic:
651
652 useleft = USE_LEFT(svl);
28e5dec8
JH
653 /* We must see if we can perform the addition with integers if possible,
654 as the integer code detects overflow while the NV code doesn't.
655 If either argument hasn't had a numeric conversion yet attempt to get
656 the IV. It's important to do this now, rather than just assuming that
657 it's not IOK as a PV of "9223372036854775806" may not take well to NV
658 addition, and an SV which is NOK, NV=6.0 ought to be coerced to
659 integer in case the second argument is IV=9223372036854775806
660 We can (now) rely on sv_2iv to do the right thing, only setting the
661 public IOK flag if the value in the NV (or PV) slot is truly integer.
662
663 A side effect is that this also aggressively prefers integer maths over
7dca457a
NC
664 fp maths for integer values.
665
a00b5bd3 666 How to detect overflow?
7dca457a
NC
667
668 C 99 section 6.2.6.1 says
669
670 The range of nonnegative values of a signed integer type is a subrange
671 of the corresponding unsigned integer type, and the representation of
672 the same value in each type is the same. A computation involving
673 unsigned operands can never overflow, because a result that cannot be
674 represented by the resulting unsigned integer type is reduced modulo
675 the number that is one greater than the largest value that can be
676 represented by the resulting type.
677
678 (the 9th paragraph)
679
680 which I read as "unsigned ints wrap."
681
682 signed integer overflow seems to be classed as "exception condition"
683
684 If an exceptional condition occurs during the evaluation of an
685 expression (that is, if the result is not mathematically defined or not
686 in the range of representable values for its type), the behavior is
687 undefined.
688
689 (6.5, the 5th paragraph)
690
691 I had assumed that on 2s complement machines signed arithmetic would
692 wrap, hence coded pp_add and pp_subtract on the assumption that
693 everything perl builds on would be happy. After much wailing and
694 gnashing of teeth it would seem that irix64 knows its ANSI spec well,
695 knows that it doesn't need to, and doesn't. Bah. Anyway, the all-
696 unsigned code below is actually shorter than the old code. :-)
697 */
698
01f91bf2 699 if (SvIV_please_nomg(svr)) {
28e5dec8
JH
700 /* Unless the left argument is integer in range we are going to have to
701 use NV maths. Hence only attempt to coerce the right argument if
702 we know the left is integer. */
eb578fdb 703 UV auv = 0;
9c5ffd7c 704 bool auvok = FALSE;
7dca457a
NC
705 bool a_valid = 0;
706
28e5dec8 707 if (!useleft) {
7dca457a
NC
708 auv = 0;
709 a_valid = auvok = 1;
710 /* left operand is undef, treat as zero. + 0 is identity,
711 Could SETi or SETu right now, but space optimise by not adding
712 lots of code to speed up what is probably a rarish case. */
713 } else {
714 /* Left operand is defined, so is it IV? */
01f91bf2 715 if (SvIV_please_nomg(svl)) {
800401ee
JH
716 if ((auvok = SvUOK(svl)))
717 auv = SvUVX(svl);
7dca457a 718 else {
eb578fdb 719 const IV aiv = SvIVX(svl);
7dca457a
NC
720 if (aiv >= 0) {
721 auv = aiv;
722 auvok = 1; /* Now acting as a sign flag. */
53e2bfb7
DM
723 } else {
724 auv = (aiv == IV_MIN) ? (UV)aiv : (UV)(-aiv);
7dca457a
NC
725 }
726 }
727 a_valid = 1;
28e5dec8
JH
728 }
729 }
7dca457a
NC
730 if (a_valid) {
731 bool result_good = 0;
732 UV result;
eb578fdb 733 UV buv;
800401ee 734 bool buvok = SvUOK(svr);
a00b5bd3 735
7dca457a 736 if (buvok)
800401ee 737 buv = SvUVX(svr);
7dca457a 738 else {
eb578fdb 739 const IV biv = SvIVX(svr);
7dca457a
NC
740 if (biv >= 0) {
741 buv = biv;
742 buvok = 1;
743 } else
53e2bfb7 744 buv = (biv == IV_MIN) ? (UV)biv : (UV)(-biv);
7dca457a
NC
745 }
746 /* ?uvok if value is >= 0. basically, flagged as UV if it's +ve,
602f51c4 747 else "IV" now, independent of how it came in.
7dca457a
NC
748 if a, b represents positive, A, B negative, a maps to -A etc
749 a + b => (a + b)
750 A + b => -(a - b)
751 a + B => (a - b)
752 A + B => -(a + b)
753 all UV maths. negate result if A negative.
754 add if signs same, subtract if signs differ. */
755
756 if (auvok ^ buvok) {
757 /* Signs differ. */
758 if (auv >= buv) {
759 result = auv - buv;
760 /* Must get smaller */
761 if (result <= auv)
762 result_good = 1;
763 } else {
764 result = buv - auv;
765 if (result <= buv) {
766 /* result really should be -(auv-buv). as its negation
767 of true value, need to swap our result flag */
768 auvok = !auvok;
769 result_good = 1;
28e5dec8
JH
770 }
771 }
7dca457a
NC
772 } else {
773 /* Signs same */
774 result = auv + buv;
775 if (result >= auv)
776 result_good = 1;
777 }
778 if (result_good) {
779 SP--;
780 if (auvok)
28e5dec8 781 SETu( result );
7dca457a
NC
782 else {
783 /* Negate result */
784 if (result <= (UV)IV_MIN)
53e2bfb7
DM
785 SETi(result == (UV)IV_MIN
786 ? IV_MIN : -(IV)result);
7dca457a
NC
787 else {
788 /* result valid, but out of range for IV. */
789 SETn( -(NV)result );
28e5dec8
JH
790 }
791 }
7dca457a
NC
792 RETURN;
793 } /* Overflow, drop through to NVs. */
28e5dec8
JH
794 }
795 }
230ee21f
DM
796
797#else
798 useleft = USE_LEFT(svl);
28e5dec8 799#endif
230ee21f 800
a0d0e21e 801 {
6f1401dc 802 NV value = SvNV_nomg(svr);
4efa5a16 803 (void)POPs;
28e5dec8
JH
804 if (!useleft) {
805 /* left operand is undef, treat as zero. + 0.0 is identity. */
806 SETn(value);
807 RETURN;
808 }
6f1401dc 809 SETn( value + SvNV_nomg(svl) );
28e5dec8 810 RETURN;
a0d0e21e
LW
811 }
812}
813
b1c05ba5
DM
814
815/* also used for: pp_aelemfast_lex() */
816
a0d0e21e
LW
817PP(pp_aelemfast)
818{
20b7effb 819 dSP;
93bad3fd 820 AV * const av = PL_op->op_type == OP_AELEMFAST_LEX
8f878375 821 ? MUTABLE_AV(PAD_SV(PL_op->op_targ)) : GvAVn(cGVOP_gv);
a3b680e6 822 const U32 lval = PL_op->op_flags & OPf_MOD;
7e169e84
DM
823 const I8 key = (I8)PL_op->op_private;
824 SV** svp;
825 SV *sv;
826
827 assert(SvTYPE(av) == SVt_PVAV);
828
f4484b87
DM
829 EXTEND(SP, 1);
830
7e169e84
DM
831 /* inlined av_fetch() for simple cases ... */
832 if (!SvRMAGICAL(av) && key >= 0 && key <= AvFILLp(av)) {
833 sv = AvARRAY(av)[key];
9fb994be 834 if (sv) {
7e169e84
DM
835 PUSHs(sv);
836 RETURN;
837 }
838 }
839
840 /* ... else do it the hard way */
841 svp = av_fetch(av, key, lval);
842 sv = (svp ? *svp : &PL_sv_undef);
b024352e
DM
843
844 if (UNLIKELY(!svp && lval))
7e169e84 845 DIE(aTHX_ PL_no_aelem, (int)key);
b024352e 846
39cf747a 847 if (!lval && SvRMAGICAL(av) && SvGMAGICAL(sv)) /* see note in pp_helem() */
fd69380d 848 mg_get(sv);
be6c24e0 849 PUSHs(sv);
a0d0e21e
LW
850 RETURN;
851}
852
853PP(pp_join)
854{
20b7effb 855 dSP; dMARK; dTARGET;
a0d0e21e
LW
856 MARK++;
857 do_join(TARG, *MARK, MARK, SP);
858 SP = MARK;
859 SETs(TARG);
860 RETURN;
861}
862
a0d0e21e
LW
863/* Oversized hot code. */
864
b1c05ba5
DM
865/* also used for: pp_say() */
866
a0d0e21e
LW
867PP(pp_print)
868{
20b7effb 869 dSP; dMARK; dORIGMARK;
eb578fdb 870 PerlIO *fp;
236988e4 871 MAGIC *mg;
159b6efe
NC
872 GV * const gv
873 = (PL_op->op_flags & OPf_STACKED) ? MUTABLE_GV(*++MARK) : PL_defoutgv;
9c9f25b8 874 IO *io = GvIO(gv);
5b468f54 875
9c9f25b8 876 if (io
ad64d0ec 877 && (mg = SvTIED_mg((const SV *)io, PERL_MAGIC_tiedscalar)))
5b468f54 878 {
01bb7c6d 879 had_magic:
68dc0745 880 if (MARK == ORIGMARK) {
1c846c1f 881 /* If using default handle then we need to make space to
a60c0954
NIS
882 * pass object as 1st arg, so move other args up ...
883 */
4352c267 884 MEXTEND(SP, 1);
68dc0745
PP
885 ++MARK;
886 Move(MARK, MARK + 1, (SP - MARK) + 1, SV*);
887 ++SP;
888 }
3e0cb5de 889 return Perl_tied_method(aTHX_ SV_CONST(PRINT), mark - 1, MUTABLE_SV(io),
94bc412f
NC
890 mg,
891 (G_SCALAR | TIED_METHOD_ARGUMENTS_ON_STACK
892 | (PL_op->op_type == OP_SAY
893 ? TIED_METHOD_SAY : 0)), sp - mark);
236988e4 894 }
9c9f25b8 895 if (!io) {
68b590d9 896 if ( gv && GvEGVx(gv) && (io = GvIO(GvEGV(gv)))
ad64d0ec 897 && (mg = SvTIED_mg((const SV *)io, PERL_MAGIC_tiedscalar)))
01bb7c6d 898 goto had_magic;
51087808 899 report_evil_fh(gv);
93189314 900 SETERRNO(EBADF,RMS_IFI);
a0d0e21e
LW
901 goto just_say_no;
902 }
903 else if (!(fp = IoOFP(io))) {
7716c5c5
NC
904 if (IoIFP(io))
905 report_wrongway_fh(gv, '<');
51087808 906 else
7716c5c5 907 report_evil_fh(gv);
93189314 908 SETERRNO(EBADF,IoIFP(io)?RMS_FAC:RMS_IFI);
a0d0e21e
LW
909 goto just_say_no;
910 }
911 else {
e23d9e2f 912 SV * const ofs = GvSV(PL_ofsgv); /* $, */
a0d0e21e 913 MARK++;
e23d9e2f 914 if (ofs && (SvGMAGICAL(ofs) || SvOK(ofs))) {
a0d0e21e
LW
915 while (MARK <= SP) {
916 if (!do_print(*MARK, fp))
917 break;
918 MARK++;
919 if (MARK <= SP) {
e23d9e2f
CS
920 /* don't use 'ofs' here - it may be invalidated by magic callbacks */
921 if (!do_print(GvSV(PL_ofsgv), fp)) {
a0d0e21e
LW
922 MARK--;
923 break;
924 }
925 }
926 }
927 }
928 else {
929 while (MARK <= SP) {
930 if (!do_print(*MARK, fp))
931 break;
932 MARK++;
933 }
934 }
935 if (MARK <= SP)
936 goto just_say_no;
937 else {
cfc4a7da
GA
938 if (PL_op->op_type == OP_SAY) {
939 if (PerlIO_write(fp, "\n", 1) == 0 || PerlIO_error(fp))
940 goto just_say_no;
941 }
942 else if (PL_ors_sv && SvOK(PL_ors_sv))
7889fe52 943 if (!do_print(PL_ors_sv, fp)) /* $\ */
a0d0e21e
LW
944 goto just_say_no;
945
946 if (IoFLAGS(io) & IOf_FLUSH)
760ac839 947 if (PerlIO_flush(fp) == EOF)
a0d0e21e
LW
948 goto just_say_no;
949 }
950 }
951 SP = ORIGMARK;
e52fd6f4 952 XPUSHs(&PL_sv_yes);
a0d0e21e
LW
953 RETURN;
954
955 just_say_no:
956 SP = ORIGMARK;
e52fd6f4 957 XPUSHs(&PL_sv_undef);
a0d0e21e
LW
958 RETURN;
959}
960
b1c05ba5
DM
961
962/* also used for: pp_rv2hv() */
bdaf10a5 963/* also called directly by pp_lvavref */
b1c05ba5 964
a0d0e21e
LW
965PP(pp_rv2av)
966{
20b7effb 967 dSP; dTOPss;
1c23e2bd 968 const U8 gimme = GIMME_V;
13c59d41
MH
969 static const char an_array[] = "an ARRAY";
970 static const char a_hash[] = "a HASH";
bdaf10a5
FC
971 const bool is_pp_rv2av = PL_op->op_type == OP_RV2AV
972 || PL_op->op_type == OP_LVAVREF;
d83b45b8 973 const svtype type = is_pp_rv2av ? SVt_PVAV : SVt_PVHV;
a0d0e21e 974
9026059d 975 SvGETMAGIC(sv);
a0d0e21e 976 if (SvROK(sv)) {
5d9574c1 977 if (UNLIKELY(SvAMAGIC(sv))) {
93d7320b 978 sv = amagic_deref_call(sv, is_pp_rv2av ? to_av_amg : to_hv_amg);
93d7320b 979 }
17ab7946 980 sv = SvRV(sv);
5d9574c1 981 if (UNLIKELY(SvTYPE(sv) != type))
dcbac5bb 982 /* diag_listed_as: Not an ARRAY reference */
13c59d41 983 DIE(aTHX_ "Not %s reference", is_pp_rv2av ? an_array : a_hash);
5d9574c1
DM
984 else if (UNLIKELY(PL_op->op_flags & OPf_MOD
985 && PL_op->op_private & OPpLVAL_INTRO))
3da99855 986 Perl_croak(aTHX_ "%s", PL_no_localize_ref);
a0d0e21e 987 }
5d9574c1 988 else if (UNLIKELY(SvTYPE(sv) != type)) {
67955e0c 989 GV *gv;
1c846c1f 990
6e592b3a 991 if (!isGV_with_GP(sv)) {
13c59d41 992 gv = Perl_softref2xv(aTHX_ sv, is_pp_rv2av ? an_array : a_hash,
dc3c76f8
NC
993 type, &sp);
994 if (!gv)
995 RETURN;
35cd451c
GS
996 }
997 else {
159b6efe 998 gv = MUTABLE_GV(sv);
a0d0e21e 999 }
ad64d0ec 1000 sv = is_pp_rv2av ? MUTABLE_SV(GvAVn(gv)) : MUTABLE_SV(GvHVn(gv));
533c011a 1001 if (PL_op->op_private & OPpLVAL_INTRO)
ad64d0ec 1002 sv = is_pp_rv2av ? MUTABLE_SV(save_ary(gv)) : MUTABLE_SV(save_hash(gv));
9f527363
FC
1003 }
1004 if (PL_op->op_flags & OPf_REF) {
17ab7946 1005 SETs(sv);
a0d0e21e 1006 RETURN;
9f527363 1007 }
5d9574c1 1008 else if (UNLIKELY(PL_op->op_private & OPpMAYBE_LVSUB)) {
40c94d11
FC
1009 const I32 flags = is_lvalue_sub();
1010 if (flags && !(flags & OPpENTERSUB_INARGS)) {
cde874ca 1011 if (gimme != G_ARRAY)
042560a6 1012 goto croak_cant_return;
17ab7946 1013 SETs(sv);
78f9721b 1014 RETURN;
40c94d11 1015 }
a0d0e21e
LW
1016 }
1017
17ab7946 1018 if (is_pp_rv2av) {
502c6561 1019 AV *const av = MUTABLE_AV(sv);
636fe681 1020 /* The guts of pp_rv2av */
96913b52 1021 if (gimme == G_ARRAY) {
d5524600
DM
1022 SP--;
1023 PUTBACK;
1024 S_pushav(aTHX_ av);
1025 SPAGAIN;
1c846c1f 1026 }
96913b52
VP
1027 else if (gimme == G_SCALAR) {
1028 dTARGET;
c70927a6 1029 const SSize_t maxarg = AvFILL(av) + 1;
96913b52 1030 SETi(maxarg);
93965878 1031 }
17ab7946
NC
1032 } else {
1033 /* The guts of pp_rv2hv */
96913b52
VP
1034 if (gimme == G_ARRAY) { /* array wanted */
1035 *PL_stack_sp = sv;
981b7185 1036 return Perl_do_kv(aTHX);
96913b52 1037 }
c8fe3bdf 1038 else if ((PL_op->op_private & OPpTRUEBOOL
adc42c31 1039 || ( PL_op->op_private & OPpMAYBE_TRUEBOOL
c8fe3bdf
FC
1040 && block_gimme() == G_VOID ))
1041 && (!SvRMAGICAL(sv) || !mg_find(sv, PERL_MAGIC_tied)))
1042 SETs(HvUSEDKEYS(sv) ? &PL_sv_yes : sv_2mortal(newSViv(0)));
96913b52 1043 else if (gimme == G_SCALAR) {
1a8bdda9 1044 dTARG;
96913b52 1045 TARG = Perl_hv_scalar(aTHX_ MUTABLE_HV(sv));
96913b52
VP
1046 SETTARG;
1047 }
17ab7946 1048 }
be85d344 1049 RETURN;
042560a6
NC
1050
1051 croak_cant_return:
1052 Perl_croak(aTHX_ "Can't return %s to lvalue scalar context",
1053 is_pp_rv2av ? "array" : "hash");
77e217c6 1054 RETURN;
a0d0e21e
LW
1055}
1056
10c8fecd 1057STATIC void
fb8f4cf8 1058S_do_oddball(pTHX_ SV **oddkey, SV **firstkey)
10c8fecd 1059{
7918f24d
NC
1060 PERL_ARGS_ASSERT_DO_ODDBALL;
1061
fb8f4cf8 1062 if (*oddkey) {
6d822dc4 1063 if (ckWARN(WARN_MISC)) {
a3b680e6 1064 const char *err;
fb8f4cf8
RZ
1065 if (oddkey == firstkey &&
1066 SvROK(*oddkey) &&
1067 (SvTYPE(SvRV(*oddkey)) == SVt_PVAV ||
1068 SvTYPE(SvRV(*oddkey)) == SVt_PVHV))
10c8fecd 1069 {
a3b680e6 1070 err = "Reference found where even-sized list expected";
10c8fecd
GS
1071 }
1072 else
a3b680e6 1073 err = "Odd number of elements in hash assignment";
f1f66076 1074 Perl_warner(aTHX_ packWARN(WARN_MISC), "%s", err);
10c8fecd 1075 }
6d822dc4 1076
10c8fecd
GS
1077 }
1078}
1079
a5f48505
DM
1080
1081/* Do a mark and sweep with the SVf_BREAK flag to detect elements which
1082 * are common to both the LHS and RHS of an aassign, and replace them
1083 * with copies. All these copies are made before the actual list assign is
1084 * done.
1085 *
1086 * For example in ($a,$b) = ($b,$a), assigning the value of the first RHS
1087 * element ($b) to the first LH element ($a), modifies $a; when the
1088 * second assignment is done, the second RH element now has the wrong
1089 * value. So we initially replace the RHS with ($b, mortalcopy($a)).
1090 * Note that we don't need to make a mortal copy of $b.
1091 *
1092 * The algorithm below works by, for every RHS element, mark the
1093 * corresponding LHS target element with SVf_BREAK. Then if the RHS
1094 * element is found with SVf_BREAK set, it means it would have been
1095 * modified, so make a copy.
1096 * Note that by scanning both LHS and RHS in lockstep, we avoid
1097 * unnecessary copies (like $b above) compared with a naive
1098 * "mark all LHS; copy all marked RHS; unmark all LHS".
1099 *
1100 * If the LHS element is a 'my' declaration' and has a refcount of 1, then
1101 * it can't be common and can be skipped.
ebc643ce
DM
1102 *
1103 * On DEBUGGING builds it takes an extra boolean, fake. If true, it means
1104 * that we thought we didn't need to call S_aassign_copy_common(), but we
1105 * have anyway for sanity checking. If we find we need to copy, then panic.
a5f48505
DM
1106 */
1107
1108PERL_STATIC_INLINE void
1109S_aassign_copy_common(pTHX_ SV **firstlelem, SV **lastlelem,
ebc643ce
DM
1110 SV **firstrelem, SV **lastrelem
1111#ifdef DEBUGGING
1112 , bool fake
1113#endif
1114)
a5f48505
DM
1115{
1116 dVAR;
1117 SV **relem;
1118 SV **lelem;
1119 SSize_t lcount = lastlelem - firstlelem + 1;
1120 bool marked = FALSE; /* have we marked any LHS with SVf_BREAK ? */
1121 bool const do_rc1 = cBOOL(PL_op->op_private & OPpASSIGN_COMMON_RC1);
beb08a1e 1122 bool copy_all = FALSE;
a5f48505
DM
1123
1124 assert(!PL_in_clean_all); /* SVf_BREAK not already in use */
1125 assert(firstlelem < lastlelem); /* at least 2 LH elements */
1126 assert(firstrelem < lastrelem); /* at least 2 RH elements */
1127
ebc643ce
DM
1128
1129 lelem = firstlelem;
a5f48505
DM
1130 /* we never have to copy the first RH element; it can't be corrupted
1131 * by assigning something to the corresponding first LH element.
1132 * So this scan does in a loop: mark LHS[N]; test RHS[N+1]
1133 */
ebc643ce 1134 relem = firstrelem + 1;
a5f48505
DM
1135
1136 for (; relem <= lastrelem; relem++) {
1137 SV *svr;
1138
1139 /* mark next LH element */
1140
1141 if (--lcount >= 0) {
1142 SV *svl = *lelem++;
1143
1144 if (UNLIKELY(!svl)) {/* skip AV alias marker */
1145 assert (lelem <= lastlelem);
1146 svl = *lelem++;
1147 lcount--;
1148 }
1149
1150 assert(svl);
beb08a1e
TC
1151 if (SvSMAGICAL(svl)) {
1152 copy_all = TRUE;
1153 }
a5f48505
DM
1154 if (SvTYPE(svl) == SVt_PVAV || SvTYPE(svl) == SVt_PVHV) {
1155 if (!marked)
1156 return;
1157 /* this LH element will consume all further args;
1158 * no need to mark any further LH elements (if any).
1159 * But we still need to scan any remaining RHS elements;
1160 * set lcount negative to distinguish from lcount == 0,
1161 * so the loop condition continues being true
1162 */
1163 lcount = -1;
1164 lelem--; /* no need to unmark this element */
1165 }
1166 else if (!(do_rc1 && SvREFCNT(svl) == 1) && svl != &PL_sv_undef) {
1167 assert(!SvIMMORTAL(svl));
1168 SvFLAGS(svl) |= SVf_BREAK;
1169 marked = TRUE;
1170 }
1171 else if (!marked) {
1172 /* don't check RH element if no SVf_BREAK flags set yet */
1173 if (!lcount)
1174 break;
1175 continue;
1176 }
1177 }
1178
1179 /* see if corresponding RH element needs copying */
1180
1181 assert(marked);
1182 svr = *relem;
1183 assert(svr);
1184
5c1db569 1185 if (UNLIKELY(SvFLAGS(svr) & (SVf_BREAK|SVs_GMG) || copy_all)) {
a5f48505 1186
ebc643ce
DM
1187#ifdef DEBUGGING
1188 if (fake) {
9ae0115f 1189 /* op_dump(PL_op); */
ebc643ce
DM
1190 Perl_croak(aTHX_
1191 "panic: aassign skipped needed copy of common RH elem %"
1192 UVuf, (UV)(relem - firstrelem));
1193 }
1194#endif
1195
a5f48505
DM
1196 TAINT_NOT; /* Each item is independent */
1197
1198 /* Dear TODO test in t/op/sort.t, I love you.
1199 (It's relying on a panic, not a "semi-panic" from newSVsv()
1200 and then an assertion failure below.) */
1201 if (UNLIKELY(SvIS_FREED(svr))) {
1202 Perl_croak(aTHX_ "panic: attempt to copy freed scalar %p",
1203 (void*)svr);
1204 }
1205 /* avoid break flag while copying; otherwise COW etc
1206 * disabled... */
1207 SvFLAGS(svr) &= ~SVf_BREAK;
1208 /* Not newSVsv(), as it does not allow copy-on-write,
8c1e192f
DM
1209 resulting in wasteful copies.
1210 Also, we use SV_NOSTEAL in case the SV is used more than
1211 once, e.g. (...) = (f())[0,0]
1212 Where the same SV appears twice on the RHS without a ref
1213 count bump. (Although I suspect that the SV won't be
1214 stealable here anyway - DAPM).
1215 */
a5f48505
DM
1216 *relem = sv_mortalcopy_flags(svr,
1217 SV_GMAGIC|SV_DO_COW_SVSETSV|SV_NOSTEAL);
1218 /* ... but restore afterwards in case it's needed again,
1219 * e.g. ($a,$b,$c) = (1,$a,$a)
1220 */
1221 SvFLAGS(svr) |= SVf_BREAK;
1222 }
1223
1224 if (!lcount)
1225 break;
1226 }
1227
1228 if (!marked)
1229 return;
1230
1231 /*unmark LHS */
1232
1233 while (lelem > firstlelem) {
1234 SV * const svl = *(--lelem);
1235 if (svl)
1236 SvFLAGS(svl) &= ~SVf_BREAK;
1237 }
1238}
1239
1240
1241
a0d0e21e
LW
1242PP(pp_aassign)
1243{
27da23d5 1244 dVAR; dSP;
3280af22
NIS
1245 SV **lastlelem = PL_stack_sp;
1246 SV **lastrelem = PL_stack_base + POPMARK;
1247 SV **firstrelem = PL_stack_base + POPMARK + 1;
a0d0e21e
LW
1248 SV **firstlelem = lastrelem + 1;
1249
eb578fdb
KW
1250 SV **relem;
1251 SV **lelem;
1c23e2bd 1252 U8 gimme;
a68090fe
DM
1253 /* PL_delaymagic is restored by JUMPENV_POP on dieing, so we
1254 * only need to save locally, not on the save stack */
1255 U16 old_delaymagic = PL_delaymagic;
ebc643ce
DM
1256#ifdef DEBUGGING
1257 bool fake = 0;
1258#endif
5637b936 1259
3280af22 1260 PL_delaymagic = DM_DELAY; /* catch simultaneous items */
a0d0e21e
LW
1261
1262 /* If there's a common identifier on both sides we have to take
1263 * special care that assigning the identifier on the left doesn't
1264 * clobber a value on the right that's used later in the list.
1265 */
acdea6f0 1266
beb08a1e
TC
1267 /* at least 2 LH and RH elements, or commonality isn't an issue */
1268 if (firstlelem < lastlelem && firstrelem < lastrelem) {
5c1db569
TC
1269 for (relem = firstrelem+1; relem <= lastrelem; relem++) {
1270 if (SvGMAGICAL(*relem))
1271 goto do_scan;
1272 }
beb08a1e
TC
1273 for (lelem = firstlelem; lelem <= lastlelem; lelem++) {
1274 if (*lelem && SvSMAGICAL(*lelem))
1275 goto do_scan;
a5f48505 1276 }
beb08a1e
TC
1277 if ( PL_op->op_private & (OPpASSIGN_COMMON_SCALAR|OPpASSIGN_COMMON_RC1) ) {
1278 if (PL_op->op_private & OPpASSIGN_COMMON_RC1) {
1279 /* skip the scan if all scalars have a ref count of 1 */
1280 for (lelem = firstlelem; lelem <= lastlelem; lelem++) {
8b0c3377 1281 SV *sv = *lelem;
beb08a1e
TC
1282 if (!sv || SvREFCNT(sv) == 1)
1283 continue;
1284 if (SvTYPE(sv) != SVt_PVAV && SvTYPE(sv) != SVt_PVAV)
1285 goto do_scan;
1286 break;
1287 }
1288 }
1289 else {
1290 do_scan:
1291 S_aassign_copy_common(aTHX_
1292 firstlelem, lastlelem, firstrelem, lastrelem
ebc643ce 1293#ifdef DEBUGGING
beb08a1e 1294 , fake
ebc643ce 1295#endif
beb08a1e
TC
1296 );
1297 }
a5f48505 1298 }
a0d0e21e 1299 }
ebc643ce
DM
1300#ifdef DEBUGGING
1301 else {
1302 /* on debugging builds, do the scan even if we've concluded we
1303 * don't need to, then panic if we find commonality. Note that the
1304 * scanner assumes at least 2 elements */
1305 if (firstlelem < lastlelem && firstrelem < lastrelem) {
1306 fake = 1;
1307 goto do_scan;
1308 }
1309 }
1310#endif
a0d0e21e 1311
a5f48505 1312 gimme = GIMME_V;
a0d0e21e
LW
1313 relem = firstrelem;
1314 lelem = firstlelem;
10c8fecd 1315
8b0c3377
DM
1316 if (relem > lastrelem)
1317 goto no_relems;
1318
1319 /* first lelem loop while there are still relems */
5d9574c1 1320 while (LIKELY(lelem <= lastlelem)) {
bdaf10a5 1321 bool alias = FALSE;
8b0c3377
DM
1322 SV *lsv = *lelem++;
1323
1324 assert(relem <= lastrelem);
1325 if (UNLIKELY(!lsv)) {
bdaf10a5 1326 alias = TRUE;
8b0c3377
DM
1327 lsv = *lelem++;
1328 ASSUME(SvTYPE(lsv) == SVt_PVAV);
bdaf10a5 1329 }
a5f48505 1330
8b0c3377
DM
1331 switch (SvTYPE(lsv)) {
1332 case SVt_PVAV: {
1333 SV **svp;
1334 SSize_t i;
1335 SSize_t tmps_base;
1336 SSize_t nelems = lastrelem - relem + 1;
b09ed995 1337 AV *ary = MUTABLE_AV(lsv);
8b0c3377
DM
1338
1339 /* Assigning to an aggregate is tricky. First there is the
1340 * issue of commonality, e.g. @a = ($a[0]). Since the
1341 * stack isn't refcounted, clearing @a prior to storing
1342 * elements will free $a[0]. Similarly with
1343 * sub FETCH { $status[$_[1]] } @status = @tied[0,1];
1344 *
1345 * The way to avoid these issues is to make the copy of each
1346 * SV (and we normally store a *copy* in the array) *before*
1347 * clearing the array. But this has a problem in that
1348 * if the code croaks during copying, the not-yet-stored copies
1349 * could leak. One way to avoid this is to make all the copies
1350 * mortal, but that's quite expensive.
1351 *
1352 * The current solution to these issues is to use a chunk
1353 * of the tmps stack as a temporary refcounted-stack. SVs
1354 * will be put on there during processing to avoid leaks,
1355 * but will be removed again before the end of this block,
1356 * so free_tmps() is never normally called. Also, the
1357 * sv_refcnt of the SVs doesn't have to be manipulated, since
1358 * the ownership of 1 reference count is transferred directly
1359 * from the tmps stack to the AV when the SV is stored.
1360 *
1361 * We disarm slots in the temps stack by storing PL_sv_undef
1362 * there: it doesn't matter if that SV's refcount is
1363 * repeatedly decremented during a croak. But usually this is
1364 * only an interim measure. By the end of this code block
1365 * we try where possible to not leave any PL_sv_undef's on the
1366 * tmps stack e.g. by shuffling newer entries down.
1367 *
1368 * There is one case where we don't copy: non-magical
1369 * SvTEMP(sv)'s with a ref count of 1. The only owner of these
1370 * is on the tmps stack, so its safe to directly steal the SV
1371 * rather than copying. This is common in things like function
1372 * returns, map etc, which all return a list of such SVs.
1373 *
1374 * Note however something like @a = (f())[0,0], where there is
1375 * a danger of the same SV being shared: this avoided because
1376 * when the SV is stored as $a[0], its ref count gets bumped,
1377 * so the RC==1 test fails and the second element is copied
1378 * instead.
1379 *
1380 * We also use one slot in the tmps stack to hold an extra
1381 * ref to the array, to ensure it doesn't get prematurely
1382 * freed. Again, this is removed before the end of this block.
1383 *
1384 * Note that OPpASSIGN_COMMON_AGG is used to flag a possible
1385 * @a = ($a[0]) case, but the current implementation uses the
1386 * same algorithm regardless, so ignores that flag. (It *is*
1387 * used in the hash branch below, however).
1388 */
1389
1390 /* Reserve slots for ary, plus the elems we're about to copy,
1391 * then protect ary and temporarily void the remaining slots
1392 * with &PL_sv_undef */
1393 EXTEND_MORTAL(nelems + 1);
1394 PL_tmps_stack[++PL_tmps_ix] = SvREFCNT_inc_simple_NN(ary);
1395 tmps_base = PL_tmps_ix + 1;
1396 for (i = 0; i < nelems; i++)
1397 PL_tmps_stack[tmps_base + i] = &PL_sv_undef;
1398 PL_tmps_ix += nelems;
1399
1400 /* Make a copy of each RHS elem and save on the tmps_stack
1401 * (or pass through where we can optimise away the copy) */
1402
1403 if (UNLIKELY(alias)) {
1404 U32 lval = (gimme == G_ARRAY)
1405 ? (PL_op->op_flags & OPf_MOD || LVRET) : 0;
a5f48505 1406 for (svp = relem; svp <= lastrelem; svp++) {
8b0c3377
DM
1407 SV *rsv = *svp;
1408
1409 SvGETMAGIC(rsv);
1410 if (!SvROK(rsv))
1411 DIE(aTHX_ "Assigned value is not a reference");
1412 if (SvTYPE(SvRV(rsv)) > SVt_PVLV)
1413 /* diag_listed_as: Assigned value is not %s reference */
1414 DIE(aTHX_
1415 "Assigned value is not a SCALAR reference");
1416 if (lval)
1417 *svp = rsv = sv_mortalcopy(rsv);
1418 /* XXX else check for weak refs? */
1419 rsv = SvREFCNT_inc_NN(SvRV(rsv));
1420 assert(tmps_base <= PL_tmps_max);
1421 PL_tmps_stack[tmps_base++] = rsv;
a5f48505 1422 }
a5f48505 1423 }
8b0c3377
DM
1424 else {
1425 for (svp = relem; svp <= lastrelem; svp++) {
1426 SV *rsv = *svp;
a5f48505 1427
8b0c3377
DM
1428 if (SvTEMP(rsv) && !SvGMAGICAL(rsv) && SvREFCNT(rsv) == 1) {
1429 /* can skip the copy */
1430 SvREFCNT_inc_simple_void_NN(rsv);
1431 SvTEMP_off(rsv);
1432 }
a5f48505 1433 else {
8b0c3377
DM
1434 SV *nsv;
1435 /* do get before newSV, in case it dies and leaks */
1436 SvGETMAGIC(rsv);
1437 nsv = newSV(0);
8c1e192f
DM
1438 /* see comment in S_aassign_copy_common about
1439 * SV_NOSTEAL */
8b0c3377
DM
1440 sv_setsv_flags(nsv, rsv,
1441 (SV_DO_COW_SVSETSV|SV_NOSTEAL));
1442 rsv = *svp = nsv;
a5f48505 1443 }
8b0c3377
DM
1444
1445 assert(tmps_base <= PL_tmps_max);
1446 PL_tmps_stack[tmps_base++] = rsv;
1447 }
1448 }
1449
1450 if (SvRMAGICAL(ary) || AvFILLp(ary) >= 0) /* may be non-empty */
1451 av_clear(ary);
1452
1453 /* store in the array, the SVs that are in the tmps stack */
1454
1455 tmps_base -= nelems;
1456
1457 if (SvRMAGICAL(ary) || SvREADONLY(ary) || !AvREAL(ary)) {
1458 /* for arrays we can't cheat with, use the official API */
1459 av_extend(ary, nelems - 1);
1460 for (i = 0; i < nelems; i++) {
1461 SV **svp = &(PL_tmps_stack[tmps_base + i]);
1462 SV *rsv = *svp;
1463 /* A tied store won't take ownership of rsv, so keep
1464 * the 1 refcnt on the tmps stack; otherwise disarm
1465 * the tmps stack entry */
1466 if (av_store(ary, i, rsv))
1467 *svp = &PL_sv_undef;
1468 /* av_store() may have added set magic to rsv */;
1469 SvSETMAGIC(rsv);
1470 }
1471 /* disarm ary refcount: see comments below about leak */
1472 PL_tmps_stack[tmps_base - 1] = &PL_sv_undef;
1473 }
1474 else {
1475 /* directly access/set the guts of the AV */
1476 SSize_t fill = nelems - 1;
1477 if (fill > AvMAX(ary))
1478 av_extend_guts(ary, fill, &AvMAX(ary), &AvALLOC(ary),
1479 &AvARRAY(ary));
1480 AvFILLp(ary) = fill;
1481 Copy(&(PL_tmps_stack[tmps_base]), AvARRAY(ary), nelems, SV*);
1482 /* Quietly remove all the SVs from the tmps stack slots,
1483 * since ary has now taken ownership of the refcnt.
1484 * Also remove ary: which will now leak if we die before
1485 * the SvREFCNT_dec_NN(ary) below */
1486 if (UNLIKELY(PL_tmps_ix >= tmps_base + nelems))
1487 Move(&PL_tmps_stack[tmps_base + nelems],
1488 &PL_tmps_stack[tmps_base - 1],
1489 PL_tmps_ix - (tmps_base + nelems) + 1,
1490 SV*);
1491 PL_tmps_ix -= (nelems + 1);
1492 }
1493
5d9574c1 1494 if (UNLIKELY(PL_delaymagic & DM_ARRAY_ISA))
8b0c3377 1495 /* its assumed @ISA set magic can't die and leak ary */
ad64d0ec 1496 SvSETMAGIC(MUTABLE_SV(ary));
8b0c3377
DM
1497 SvREFCNT_dec_NN(ary);
1498
1499 relem = lastrelem + 1;
1500 goto no_relems;
a5f48505
DM
1501 }
1502
10c8fecd 1503 case SVt_PVHV: { /* normal hash */
8b0c3377
DM
1504
1505 SV **svp;
1506 bool dirty_tmps;
1507 SSize_t i;
1508 SSize_t tmps_base;
1509 SSize_t nelems = lastrelem - relem + 1;
b09ed995 1510 HV *hash = MUTABLE_HV(lsv);
8b0c3377
DM
1511
1512 if (UNLIKELY(nelems & 1)) {
1513 do_oddball(lastrelem, relem);
1514 /* we have firstlelem to reuse, it's not needed any more */
1515 *++lastrelem = &PL_sv_undef;
1516 nelems++;
1517 }
1518
1519 /* See the SVt_PVAV branch above for a long description of
1520 * how the following all works. The main difference for hashes
1521 * is that we treat keys and values separately (and have
1522 * separate loops for them): as for arrays, values are always
1523 * copied (except for the SvTEMP optimisation), since they
1524 * need to be stored in the hash; while keys are only
1525 * processed where they might get prematurely freed or
1526 * whatever. */
1527
1528 /* tmps stack slots:
1529 * * reserve a slot for the hash keepalive;
1530 * * reserve slots for the hash values we're about to copy;
1531 * * preallocate for the keys we'll possibly copy or refcount bump
1532 * later;
1533 * then protect hash and temporarily void the remaining
1534 * value slots with &PL_sv_undef */
1535 EXTEND_MORTAL(nelems + 1);
1536
1537 /* convert to number of key/value pairs */
1538 nelems >>= 1;
1539
1540 PL_tmps_stack[++PL_tmps_ix] = SvREFCNT_inc_simple_NN(hash);
1541 tmps_base = PL_tmps_ix + 1;
1542 for (i = 0; i < nelems; i++)
1543 PL_tmps_stack[tmps_base + i] = &PL_sv_undef;
1544 PL_tmps_ix += nelems;
1545
1546 /* Make a copy of each RHS hash value and save on the tmps_stack
1547 * (or pass through where we can optimise away the copy) */
1548
1549 for (svp = relem + 1; svp <= lastrelem; svp += 2) {
1550 SV *rsv = *svp;
1551
1552 if (SvTEMP(rsv) && !SvGMAGICAL(rsv) && SvREFCNT(rsv) == 1) {
1553 /* can skip the copy */
1554 SvREFCNT_inc_simple_void_NN(rsv);
1555 SvTEMP_off(rsv);
1556 }
1557 else {
1558 SV *nsv;
1559 /* do get before newSV, in case it dies and leaks */
1560 SvGETMAGIC(rsv);
1561 nsv = newSV(0);
1562 /* see comment in S_aassign_copy_common about
1563 * SV_NOSTEAL */
1564 sv_setsv_flags(nsv, rsv,
1565 (SV_DO_COW_SVSETSV|SV_NOSTEAL));
1566 rsv = *svp = nsv;
1c4ea384
RZ
1567 }
1568
8b0c3377
DM
1569 assert(tmps_base <= PL_tmps_max);
1570 PL_tmps_stack[tmps_base++] = rsv;
1571 }
1572 tmps_base -= nelems;
a5f48505 1573
a5f48505 1574
8b0c3377
DM
1575 /* possibly protect keys */
1576
1577 if (UNLIKELY(gimme == G_ARRAY)) {
1578 /* handle e.g.
1579 * @a = ((%h = ($$r, 1)), $r = "x");
1580 * $_++ for %h = (1,2,3,4);
1581 */
1582 EXTEND_MORTAL(nelems);
1583 for (svp = relem; svp <= lastrelem; svp += 2)
1584 *svp = sv_mortalcopy_flags(*svp,
1585 SV_GMAGIC|SV_DO_COW_SVSETSV|SV_NOSTEAL);
1586 }
1587 else if (PL_op->op_private & OPpASSIGN_COMMON_AGG) {
1588 /* for possible commonality, e.g.
1589 * %h = ($h{a},1)
1590 * avoid premature freeing RHS keys by mortalising
1591 * them.
1592 * For a magic element, make a copy so that its magic is
1593 * called *before* the hash is emptied (which may affect
1594 * a tied value for example).
1595 * In theory we should check for magic keys in all
1596 * cases, not just under OPpASSIGN_COMMON_AGG, but in
1597 * practice, !OPpASSIGN_COMMON_AGG implies only
1598 * constants or padtmps on the RHS.
1599 */
1600 EXTEND_MORTAL(nelems);
1601 for (svp = relem; svp <= lastrelem; svp += 2) {
1602 SV *rsv = *svp;
1603 if (UNLIKELY(SvGMAGICAL(rsv))) {
1604 SSize_t n;
a5f48505
DM
1605 *svp = sv_mortalcopy_flags(*svp,
1606 SV_GMAGIC|SV_DO_COW_SVSETSV|SV_NOSTEAL);
8b0c3377
DM
1607 /* allow other branch to continue pushing
1608 * onto tmps stack without checking each time */
1609 n = (lastrelem - relem) >> 1;
1610 EXTEND_MORTAL(n);
a5f48505 1611 }
8b0c3377
DM
1612 else
1613 PL_tmps_stack[++PL_tmps_ix] =
1614 SvREFCNT_inc_simple_NN(rsv);
a5f48505 1615 }
8b0c3377 1616 }
a5f48505 1617
8b0c3377
DM
1618 if (SvRMAGICAL(hash) || HvUSEDKEYS(hash))
1619 hv_clear(hash);
a5f48505 1620
8b0c3377
DM
1621 /* now assign the keys and values to the hash */
1622
1623 dirty_tmps = FALSE;
1624
1625 if (UNLIKELY(gimme == G_ARRAY)) {
1626 /* @a = (%h = (...)) etc */
1627 SV **svp;
1628 SV **topelem = relem;
1629
1630 for (i = 0, svp = relem; svp <= lastrelem; i++, svp++) {
1631 SV *key = *svp++;
1632 SV *val = *svp;
1633 /* remove duplicates from list we return */
1634 if (!hv_exists_ent(hash, key, 0)) {
1635 /* copy key back: possibly to an earlier
1636 * stack location if we encountered dups earlier,
1637 * The values will be updated later
1638 */
1639 *topelem = key;
1640 topelem += 2;
632b9d6f 1641 }
8b0c3377
DM
1642 /* A tied store won't take ownership of val, so keep
1643 * the 1 refcnt on the tmps stack; otherwise disarm
1644 * the tmps stack entry */
1645 if (hv_store_ent(hash, key, val, 0))
1646 PL_tmps_stack[tmps_base + i] = &PL_sv_undef;
1647 else
1648 dirty_tmps = TRUE;
1649 /* hv_store_ent() may have added set magic to val */;
1650 SvSETMAGIC(val);
1651 }
1652 if (topelem < svp) {
1c4ea384
RZ
1653 /* at this point we have removed the duplicate key/value
1654 * pairs from the stack, but the remaining values may be
1655 * wrong; i.e. with (a 1 a 2 b 3) on the stack we've removed
1656 * the (a 2), but the stack now probably contains
1657 * (a <freed> b 3), because { hv_save(a,1); hv_save(a,2) }
1658 * obliterates the earlier key. So refresh all values. */
8b0c3377
DM
1659 lastrelem = topelem - 1;
1660 while (relem < lastrelem) {
1c4ea384
RZ
1661 HE *he;
1662 he = hv_fetch_ent(hash, *relem++, 0, 0);
1663 *relem++ = (he ? HeVAL(he) : &PL_sv_undef);
1664 }
1665 }
8b0c3377
DM
1666 }
1667 else {
1668 SV **svp;
1669 for (i = 0, svp = relem; svp <= lastrelem; i++, svp++) {
1670 SV *key = *svp++;
1671 SV *val = *svp;
1672 if (hv_store_ent(hash, key, val, 0))
1673 PL_tmps_stack[tmps_base + i] = &PL_sv_undef;
1674 else
1675 dirty_tmps = TRUE;
1676 /* hv_store_ent() may have added set magic to val */;
1677 SvSETMAGIC(val);
1678 }
1679 }
1680
1681 if (dirty_tmps) {
1682 /* there are still some 'live' recounts on the tmps stack
1683 * - usually caused by storing into a tied hash. So let
1684 * free_tmps() do the proper but slow job later.
1685 * Just disarm hash refcount: see comments below about leak
1686 */
1687 PL_tmps_stack[tmps_base - 1] = &PL_sv_undef;
1688 }
1689 else {
1690 /* Quietly remove all the SVs from the tmps stack slots,
1691 * since hash has now taken ownership of the refcnt.
1692 * Also remove hash: which will now leak if we die before
1693 * the SvREFCNT_dec_NN(hash) below */
1694 if (UNLIKELY(PL_tmps_ix >= tmps_base + nelems))
1695 Move(&PL_tmps_stack[tmps_base + nelems],
1696 &PL_tmps_stack[tmps_base - 1],
1697 PL_tmps_ix - (tmps_base + nelems) + 1,
1698 SV*);
1699 PL_tmps_ix -= (nelems + 1);
1700 }
1701
1702 SvREFCNT_dec_NN(hash);
1703
1704 relem = lastrelem + 1;
1705 goto no_relems;
1706 }
1707
a0d0e21e 1708 default:
8b0c3377
DM
1709 if (!SvIMMORTAL(lsv)) {
1710 if (UNLIKELY(
1711 SvTEMP(lsv) && !SvSMAGICAL(lsv) && SvREFCNT(lsv) == 1 &&
1712 (!isGV_with_GP(lsv) || SvFAKE(lsv)) && ckWARN(WARN_MISC)
1713 ))
1714 Perl_warner(aTHX_
1715 packWARN(WARN_MISC),
1716 "Useless assignment to a temporary"
1717 );
1718 sv_setsv(lsv, *relem);
1719 *relem = lsv;
1720 SvSETMAGIC(lsv);
1721 }
1722 if (++relem > lastrelem)
1723 goto no_relems;
a0d0e21e 1724 break;
8b0c3377
DM
1725 } /* switch */
1726 } /* while */
1727
1728
1729 no_relems:
1730
1731 /* simplified lelem loop for when there are no relems left */
1732 while (LIKELY(lelem <= lastlelem)) {
1733 SV *lsv = *lelem++;
1734 if (UNLIKELY(!lsv)) {
1735 lsv = *lelem++;
1736 ASSUME(SvTYPE(lsv) == SVt_PVAV);
a0d0e21e 1737 }
8b0c3377
DM
1738
1739 switch (SvTYPE(lsv)) {
1740 case SVt_PVAV:
b09ed995
DM
1741 if (SvRMAGICAL(lsv) || AvFILLp((SV*)lsv) >= 0) {
1742 av_clear((AV*)lsv);
8b0c3377 1743 if (UNLIKELY(PL_delaymagic & DM_ARRAY_ISA))
b09ed995 1744 SvSETMAGIC(lsv);
8b0c3377
DM
1745 }
1746 break;
1747
1748 case SVt_PVHV:
b09ed995
DM
1749 if (SvRMAGICAL(lsv) || HvUSEDKEYS((HV*)lsv))
1750 hv_clear((HV*)lsv);
8b0c3377
DM
1751 break;
1752
1753 default:
1754 if (!SvIMMORTAL(lsv)) {
1755 sv_setsv(lsv, &PL_sv_undef);
1756 SvSETMAGIC(lsv);
b09ed995 1757 *relem++ = lsv;
8b0c3377
DM
1758 }
1759 break;
1760 } /* switch */
1761 } /* while */
1762
5d9574c1 1763 if (UNLIKELY(PL_delaymagic & ~DM_DELAY)) {
985213f2 1764 /* Will be used to set PL_tainting below */
dfff4baf
BF
1765 Uid_t tmp_uid = PerlProc_getuid();
1766 Uid_t tmp_euid = PerlProc_geteuid();
1767 Gid_t tmp_gid = PerlProc_getgid();
1768 Gid_t tmp_egid = PerlProc_getegid();
985213f2 1769
b469f1e0 1770 /* XXX $> et al currently silently ignore failures */
3280af22 1771 if (PL_delaymagic & DM_UID) {
a0d0e21e 1772#ifdef HAS_SETRESUID
b469f1e0
JH
1773 PERL_UNUSED_RESULT(
1774 setresuid((PL_delaymagic & DM_RUID) ? PL_delaymagic_uid : (Uid_t)-1,
1775 (PL_delaymagic & DM_EUID) ? PL_delaymagic_euid : (Uid_t)-1,
1776 (Uid_t)-1));
56febc5e
AD
1777#else
1778# ifdef HAS_SETREUID
b469f1e0
JH
1779 PERL_UNUSED_RESULT(
1780 setreuid((PL_delaymagic & DM_RUID) ? PL_delaymagic_uid : (Uid_t)-1,
1781 (PL_delaymagic & DM_EUID) ? PL_delaymagic_euid : (Uid_t)-1));
56febc5e
AD
1782# else
1783# ifdef HAS_SETRUID
b28d0864 1784 if ((PL_delaymagic & DM_UID) == DM_RUID) {
b469f1e0 1785 PERL_UNUSED_RESULT(setruid(PL_delaymagic_uid));
b28d0864 1786 PL_delaymagic &= ~DM_RUID;
a0d0e21e 1787 }
56febc5e
AD
1788# endif /* HAS_SETRUID */
1789# ifdef HAS_SETEUID
b28d0864 1790 if ((PL_delaymagic & DM_UID) == DM_EUID) {
b469f1e0 1791 PERL_UNUSED_RESULT(seteuid(PL_delaymagic_euid));
b28d0864 1792 PL_delaymagic &= ~DM_EUID;
a0d0e21e 1793 }
56febc5e 1794# endif /* HAS_SETEUID */
b28d0864 1795 if (PL_delaymagic & DM_UID) {
985213f2 1796 if (PL_delaymagic_uid != PL_delaymagic_euid)
cea2e8a9 1797 DIE(aTHX_ "No setreuid available");
b469f1e0 1798 PERL_UNUSED_RESULT(PerlProc_setuid(PL_delaymagic_uid));
a0d0e21e 1799 }
56febc5e
AD
1800# endif /* HAS_SETREUID */
1801#endif /* HAS_SETRESUID */
04783dc7 1802
985213f2
AB
1803 tmp_uid = PerlProc_getuid();
1804 tmp_euid = PerlProc_geteuid();
a0d0e21e 1805 }
b469f1e0 1806 /* XXX $> et al currently silently ignore failures */
3280af22 1807 if (PL_delaymagic & DM_GID) {
a0d0e21e 1808#ifdef HAS_SETRESGID
b469f1e0
JH
1809 PERL_UNUSED_RESULT(
1810 setresgid((PL_delaymagic & DM_RGID) ? PL_delaymagic_gid : (Gid_t)-1,
1811 (PL_delaymagic & DM_EGID) ? PL_delaymagic_egid : (Gid_t)-1,
1812 (Gid_t)-1));
56febc5e
AD
1813#else
1814# ifdef HAS_SETREGID
b469f1e0
JH
1815 PERL_UNUSED_RESULT(
1816 setregid((PL_delaymagic & DM_RGID) ? PL_delaymagic_gid : (Gid_t)-1,
1817 (PL_delaymagic & DM_EGID) ? PL_delaymagic_egid : (Gid_t)-1));
56febc5e
AD
1818# else
1819# ifdef HAS_SETRGID
b28d0864 1820 if ((PL_delaymagic & DM_GID) == DM_RGID) {
b469f1e0 1821 PERL_UNUSED_RESULT(setrgid(PL_delaymagic_gid));
b28d0864 1822 PL_delaymagic &= ~DM_RGID;
a0d0e21e 1823 }
56febc5e
AD
1824# endif /* HAS_SETRGID */
1825# ifdef HAS_SETEGID
b28d0864 1826 if ((PL_delaymagic & DM_GID) == DM_EGID) {
b469f1e0 1827 PERL_UNUSED_RESULT(setegid(PL_delaymagic_egid));
b28d0864 1828 PL_delaymagic &= ~DM_EGID;
a0d0e21e 1829 }
56febc5e 1830# endif /* HAS_SETEGID */
b28d0864 1831 if (PL_delaymagic & DM_GID) {
985213f2 1832 if (PL_delaymagic_gid != PL_delaymagic_egid)
cea2e8a9 1833 DIE(aTHX_ "No setregid available");
b469f1e0 1834 PERL_UNUSED_RESULT(PerlProc_setgid(PL_delaymagic_gid));
a0d0e21e 1835 }
56febc5e
AD
1836# endif /* HAS_SETREGID */
1837#endif /* HAS_SETRESGID */
04783dc7 1838
985213f2
AB
1839 tmp_gid = PerlProc_getgid();
1840 tmp_egid = PerlProc_getegid();
a0d0e21e 1841 }
284167a5 1842 TAINTING_set( TAINTING_get | (tmp_uid && (tmp_euid != tmp_uid || tmp_egid != tmp_gid)) );
9a9b5ec9
DM
1843#ifdef NO_TAINT_SUPPORT
1844 PERL_UNUSED_VAR(tmp_uid);
1845 PERL_UNUSED_VAR(tmp_euid);
1846 PERL_UNUSED_VAR(tmp_gid);
1847 PERL_UNUSED_VAR(tmp_egid);
1848#endif
a0d0e21e 1849 }
a68090fe 1850 PL_delaymagic = old_delaymagic;
54310121 1851
54310121
PP
1852 if (gimme == G_VOID)
1853 SP = firstrelem - 1;
1854 else if (gimme == G_SCALAR) {
1855 dTARGET;
1856 SP = firstrelem;
b09ed995 1857 EXTEND(SP,1);
8b0c3377 1858 SETi(firstlelem - firstrelem);
54310121 1859 }
b09ed995
DM
1860 else
1861 SP = relem - 1;
08aeb9f7 1862
54310121 1863 RETURN;
a0d0e21e
LW
1864}
1865
8782bef2
GB
1866PP(pp_qr)
1867{
20b7effb 1868 dSP;
eb578fdb 1869 PMOP * const pm = cPMOP;
fe578d7f 1870 REGEXP * rx = PM_GETRE(pm);
10599a69 1871 SV * const pkg = rx ? CALLREG_PACKAGE(rx) : NULL;
c4420975 1872 SV * const rv = sv_newmortal();
d63c20f2
DM
1873 CV **cvp;
1874 CV *cv;
288b8c02
NC
1875
1876 SvUPGRADE(rv, SVt_IV);
c2123ae3
NC
1877 /* For a subroutine describing itself as "This is a hacky workaround" I'm
1878 loathe to use it here, but it seems to be the right fix. Or close.
1879 The key part appears to be that it's essential for pp_qr to return a new
1880 object (SV), which implies that there needs to be an effective way to
1881 generate a new SV from the existing SV that is pre-compiled in the
1882 optree. */
1883 SvRV_set(rv, MUTABLE_SV(reg_temp_copy(NULL, rx)));
288b8c02
NC
1884 SvROK_on(rv);
1885
8d919b0a 1886 cvp = &( ReANY((REGEXP *)SvRV(rv))->qr_anoncv);
5d9574c1 1887 if (UNLIKELY((cv = *cvp) && CvCLONE(*cvp))) {
d63c20f2 1888 *cvp = cv_clone(cv);
fc2b2dca 1889 SvREFCNT_dec_NN(cv);
d63c20f2
DM
1890 }
1891
288b8c02 1892 if (pkg) {
f815daf2 1893 HV *const stash = gv_stashsv(pkg, GV_ADD);
fc2b2dca 1894 SvREFCNT_dec_NN(pkg);
288b8c02
NC
1895 (void)sv_bless(rv, stash);
1896 }
1897
5d9574c1 1898 if (UNLIKELY(RX_ISTAINTED(rx))) {
e08e52cf 1899 SvTAINTED_on(rv);
9274aefd
DM
1900 SvTAINTED_on(SvRV(rv));
1901 }
c8c13c22 1902 XPUSHs(rv);
1903 RETURN;
8782bef2
GB
1904}
1905
a0d0e21e
LW
1906PP(pp_match)
1907{
20b7effb 1908 dSP; dTARG;
eb578fdb 1909 PMOP *pm = cPMOP;
d65afb4b 1910 PMOP *dynpm = pm;
eb578fdb 1911 const char *s;
5c144d81 1912 const char *strend;
99a90e59 1913 SSize_t curpos = 0; /* initial pos() or current $+[0] */
a0d0e21e 1914 I32 global;
7fadf4a7 1915 U8 r_flags = 0;
5c144d81 1916 const char *truebase; /* Start of string */
eb578fdb 1917 REGEXP *rx = PM_GETRE(pm);
b3eb6a9b 1918 bool rxtainted;
1c23e2bd 1919 const U8 gimme = GIMME_V;
a0d0e21e 1920 STRLEN len;
a3b680e6 1921 const I32 oldsave = PL_savestack_ix;
e60df1fa 1922 I32 had_zerolen = 0;
b1422d62 1923 MAGIC *mg = NULL;
a0d0e21e 1924
533c011a 1925 if (PL_op->op_flags & OPf_STACKED)
a0d0e21e 1926 TARG = POPs;
6ffceeb7 1927 else if (ARGTARG)
59f00321 1928 GETTARGET;
a0d0e21e 1929 else {
54b9620d 1930 TARG = DEFSV;
a0d0e21e
LW
1931 EXTEND(SP,1);
1932 }
d9f424b2 1933
c277df42 1934 PUTBACK; /* EVAL blocks need stack_sp. */
69dc4b30
FC
1935 /* Skip get-magic if this is a qr// clone, because regcomp has
1936 already done it. */
f1d31338 1937 truebase = ReANY(rx)->mother_re
69dc4b30
FC
1938 ? SvPV_nomg_const(TARG, len)
1939 : SvPV_const(TARG, len);
f1d31338 1940 if (!truebase)
2269b42e 1941 DIE(aTHX_ "panic: pp_match");
f1d31338 1942 strend = truebase + len;
284167a5
SM
1943 rxtainted = (RX_ISTAINTED(rx) ||
1944 (TAINT_get && (pm->op_pmflags & PMf_RETAINT)));
9212bbba 1945 TAINT_NOT;
a0d0e21e 1946
6c864ec2 1947 /* We need to know this in case we fail out early - pos() must be reset */
de0df3c0
MH
1948 global = dynpm->op_pmflags & PMf_GLOBAL;
1949
d65afb4b 1950 /* PMdf_USED is set after a ?? matches once */
c737faaf
YO
1951 if (
1952#ifdef USE_ITHREADS
1953 SvREADONLY(PL_regex_pad[pm->op_pmoffset])
1954#else
1955 pm->op_pmflags & PMf_USED
1956#endif
1957 ) {
e5dc5375 1958 DEBUG_r(PerlIO_printf(Perl_debug_log, "?? already matched once"));
de0df3c0 1959 goto nope;
a0d0e21e
LW
1960 }
1961
5585e758
YO
1962 /* handle the empty pattern */
1963 if (!RX_PRELEN(rx) && PL_curpm && !ReANY(rx)->mother_re) {
1964 if (PL_curpm == PL_reg_curpm) {
1965 if (PL_curpm_under) {
1966 if (PL_curpm_under == PL_reg_curpm) {
1967 Perl_croak(aTHX_ "Infinite recursion via empty pattern");
1968 } else {
1969 pm = PL_curpm_under;
1970 }
1971 }
1972 } else {
1973 pm = PL_curpm;
1974 }
1975 rx = PM_GETRE(pm);
a0d0e21e 1976 }
d65afb4b 1977
389ecb56 1978 if (RX_MINLEN(rx) >= 0 && (STRLEN)RX_MINLEN(rx) > len) {
75d43e96
FC
1979 DEBUG_r(PerlIO_printf(Perl_debug_log, "String shorter than min possible regex match (%"
1980 UVuf" < %"IVdf")\n",
1981 (UV)len, (IV)RX_MINLEN(rx)));
de0df3c0 1982 goto nope;
e5dc5375 1983 }
c277df42 1984
8ef97b0e 1985 /* get pos() if //g */
de0df3c0 1986 if (global) {
b1422d62 1987 mg = mg_find_mglob(TARG);
8ef97b0e 1988 if (mg && mg->mg_len >= 0) {
25fdce4a 1989 curpos = MgBYTEPOS(mg, TARG, truebase, len);
8ef97b0e
DM
1990 /* last time pos() was set, it was zero-length match */
1991 if (mg->mg_flags & MGf_MINMATCH)
1992 had_zerolen = 1;
1993 }
a0d0e21e 1994 }
8ef97b0e 1995
6e240d0b 1996#ifdef PERL_SAWAMPERSAND
a41aa44d 1997 if ( RX_NPARENS(rx)
6502e081 1998 || PL_sawampersand
6502e081 1999 || (RX_EXTFLAGS(rx) & (RXf_EVAL_SEEN|RXf_PMf_KEEPCOPY))
5b0e71e9 2000 || (dynpm->op_pmflags & PMf_KEEPCOPY)
6e240d0b
FC
2001 )
2002#endif
2003 {
6502e081
DM
2004 r_flags |= (REXEC_COPY_STR|REXEC_COPY_SKIP_PRE);
2005 /* in @a =~ /(.)/g, we iterate multiple times, but copy the buffer
2006 * only on the first iteration. Therefore we need to copy $' as well
2007 * as $&, to make the rest of the string available for captures in
2008 * subsequent iterations */
2009 if (! (global && gimme == G_ARRAY))
2010 r_flags |= REXEC_COPY_SKIP_POST;
2011 };
5b0e71e9
DM
2012#ifdef PERL_SAWAMPERSAND
2013 if (dynpm->op_pmflags & PMf_KEEPCOPY)
2014 /* handle KEEPCOPY in pmop but not rx, eg $r=qr/a/; /$r/p */
2015 r_flags &= ~(REXEC_COPY_SKIP_PRE|REXEC_COPY_SKIP_POST);
2016#endif
22e551b9 2017
f1d31338
DM
2018 s = truebase;
2019
d7be1480 2020 play_it_again:
985afbc1 2021 if (global)
03c83e26 2022 s = truebase + curpos;
f722798b 2023
77da2310 2024 if (!CALLREGEXEC(rx, (char*)s, (char *)strend, (char*)truebase,
03c83e26 2025 had_zerolen, TARG, NULL, r_flags))
03b6c93d 2026 goto nope;
77da2310
NC
2027
2028 PL_curpm = pm;
985afbc1 2029 if (dynpm->op_pmflags & PMf_ONCE)
c737faaf 2030#ifdef USE_ITHREADS
77da2310 2031 SvREADONLY_on(PL_regex_pad[dynpm->op_pmoffset]);
c737faaf 2032#else
77da2310 2033 dynpm->op_pmflags |= PMf_USED;
c737faaf 2034#endif
a0d0e21e 2035
72311751
GS
2036 if (rxtainted)
2037 RX_MATCH_TAINTED_on(rx);
2038 TAINT_IF(RX_MATCH_TAINTED(rx));
35c2ccc3
DM
2039
2040 /* update pos */
2041
2042 if (global && (gimme != G_ARRAY || (dynpm->op_pmflags & PMf_CONTINUE))) {
b1422d62 2043 if (!mg)
35c2ccc3 2044 mg = sv_magicext_mglob(TARG);
25fdce4a 2045 MgBYTEPOS_set(mg, TARG, truebase, RX_OFFS(rx)[0].end);
adf51885
DM
2046 if (RX_ZERO_LEN(rx))
2047 mg->mg_flags |= MGf_MINMATCH;
2048 else
2049 mg->mg_flags &= ~MGf_MINMATCH;
35c2ccc3
DM
2050 }
2051
bf9dff51
DM
2052 if ((!RX_NPARENS(rx) && !global) || gimme != G_ARRAY) {
2053 LEAVE_SCOPE(oldsave);
2054 RETPUSHYES;
2055 }
2056
88ab22af
DM
2057 /* push captures on stack */
2058
bf9dff51 2059 {
07bc277f 2060 const I32 nparens = RX_NPARENS(rx);
a3b680e6 2061 I32 i = (global && !nparens) ? 1 : 0;
a0d0e21e 2062
c277df42 2063 SPAGAIN; /* EVAL blocks could move the stack. */
ffc61ed2
JH
2064 EXTEND(SP, nparens + i);
2065 EXTEND_MORTAL(nparens + i);
2066 for (i = !i; i <= nparens; i++) {
a0d0e21e 2067 PUSHs(sv_newmortal());
5d9574c1
DM
2068 if (LIKELY((RX_OFFS(rx)[i].start != -1)
2069 && RX_OFFS(rx)[i].end != -1 ))
2070 {
07bc277f 2071 const I32 len = RX_OFFS(rx)[i].end - RX_OFFS(rx)[i].start;
f1d31338 2072 const char * const s = RX_OFFS(rx)[i].start + truebase;
5d9574c1
DM
2073 if (UNLIKELY(RX_OFFS(rx)[i].end < 0 || RX_OFFS(rx)[i].start < 0
2074 || len < 0 || len > strend - s))
5637ef5b
NC
2075 DIE(aTHX_ "panic: pp_match start/end pointers, i=%ld, "
2076 "start=%ld, end=%ld, s=%p, strend=%p, len=%"UVuf,
2077 (long) i, (long) RX_OFFS(rx)[i].start,
2078 (long)RX_OFFS(rx)[i].end, s, strend, (UV) len);
a0d0e21e 2079 sv_setpvn(*SP, s, len);
cce850e4 2080 if (DO_UTF8(TARG) && is_utf8_string((U8*)s, len))
a197cbdd 2081 SvUTF8_on(*SP);
a0d0e21e
LW
2082 }
2083 }
2084 if (global) {
0e0b3e82 2085 curpos = (UV)RX_OFFS(rx)[0].end;
03c83e26 2086 had_zerolen = RX_ZERO_LEN(rx);
c277df42 2087 PUTBACK; /* EVAL blocks may use stack */
cf93c79d 2088 r_flags |= REXEC_IGNOREPOS | REXEC_NOT_FIRST;
a0d0e21e
LW
2089 goto play_it_again;
2090 }
4633a7c4 2091 LEAVE_SCOPE(oldsave);
a0d0e21e
LW
2092 RETURN;
2093 }
e5964223 2094 NOT_REACHED; /* NOTREACHED */
a0d0e21e 2095
7b52d656 2096 nope:
d65afb4b 2097 if (global && !(dynpm->op_pmflags & PMf_CONTINUE)) {
b1422d62
DM
2098 if (!mg)
2099 mg = mg_find_mglob(TARG);
2100 if (mg)
2101 mg->mg_len = -1;
a0d0e21e 2102 }
4633a7c4 2103 LEAVE_SCOPE(oldsave);
a0d0e21e
LW
2104 if (gimme == G_ARRAY)
2105 RETURN;
2106 RETPUSHNO;
2107}
2108
2109OP *
864dbfa3 2110Perl_do_readline(pTHX)
a0d0e21e 2111{
20b7effb 2112 dSP; dTARGETSTACKED;
eb578fdb 2113 SV *sv;
a0d0e21e
LW
2114 STRLEN tmplen = 0;
2115 STRLEN offset;
760ac839 2116 PerlIO *fp;
eb578fdb
KW
2117 IO * const io = GvIO(PL_last_in_gv);
2118 const I32 type = PL_op->op_type;
1c23e2bd 2119 const U8 gimme = GIMME_V;
a0d0e21e 2120
6136c704 2121 if (io) {
50db69d8 2122 const MAGIC *const mg = SvTIED_mg((const SV *)io, PERL_MAGIC_tiedscalar);
6136c704 2123 if (mg) {
3e0cb5de 2124 Perl_tied_method(aTHX_ SV_CONST(READLINE), SP, MUTABLE_SV(io), mg, gimme, 0);
6136c704 2125 if (gimme == G_SCALAR) {
50db69d8
NC
2126 SPAGAIN;
2127 SvSetSV_nosteal(TARG, TOPs);
2128 SETTARG;
6136c704 2129 }
50db69d8 2130 return NORMAL;
0b7c7b4f 2131 }
e79b0511 2132 }
4608196e 2133 fp = NULL;
a0d0e21e
LW
2134 if (io) {
2135 fp = IoIFP(io);
2136 if (!fp) {
2137 if (IoFLAGS(io) & IOf_ARGV) {
2138 if (IoFLAGS(io) & IOf_START) {
a0d0e21e 2139 IoLINES(io) = 0;
b9f2b683 2140 if (av_tindex(GvAVn(PL_last_in_gv)) < 0) {
1d7c1841 2141 IoFLAGS(io) &= ~IOf_START;
d5eb9a46 2142 do_open6(PL_last_in_gv, "-", 1, NULL, NULL, 0);
4bac9ae4 2143 SvTAINTED_off(GvSVn(PL_last_in_gv)); /* previous tainting irrelevant */
76f68e9b 2144 sv_setpvs(GvSVn(PL_last_in_gv), "-");
3280af22 2145 SvSETMAGIC(GvSV(PL_last_in_gv));
a2008d6d
GS
2146 fp = IoIFP(io);
2147 goto have_fp;
a0d0e21e
LW
2148 }
2149 }
157fb5a1 2150 fp = nextargv(PL_last_in_gv, PL_op->op_flags & OPf_SPECIAL);
a0d0e21e 2151 if (!fp) { /* Note: fp != IoIFP(io) */
3280af22 2152 (void)do_close(PL_last_in_gv, FALSE); /* now it does*/
a0d0e21e
LW
2153 }
2154 }
0d44d22b
NC
2155 else if (type == OP_GLOB)
2156 fp = Perl_start_glob(aTHX_ POPs, io);
a0d0e21e
LW
2157 }
2158 else if (type == OP_GLOB)
2159 SP--;
7716c5c5 2160 else if (IoTYPE(io) == IoTYPE_WRONLY) {
a5390457 2161 report_wrongway_fh(PL_last_in_gv, '>');
a00b5bd3 2162 }
a0d0e21e
LW
2163 }
2164 if (!fp) {
041457d9 2165 if ((!io || !(IoFLAGS(io) & IOf_START))
de7dabb6
TC
2166 && ckWARN(WARN_CLOSED)
2167 && type != OP_GLOB)
041457d9 2168 {
de7dabb6 2169 report_evil_fh(PL_last_in_gv);
3f4520fe 2170 }
54310121 2171 if (gimme == G_SCALAR) {
79628082 2172 /* undef TARG, and push that undefined value */
ba92458f 2173 if (type != OP_RCATLINE) {
aab1202a 2174 sv_setsv(TARG,NULL);
ba92458f 2175 }
a0d0e21e
LW
2176 PUSHTARG;
2177 }
2178 RETURN;
2179 }
a2008d6d 2180 have_fp:
54310121 2181 if (gimme == G_SCALAR) {
a0d0e21e 2182 sv = TARG;
0f722b55
RGS
2183 if (type == OP_RCATLINE && SvGMAGICAL(sv))
2184 mg_get(sv);
48de12d9
RGS
2185 if (SvROK(sv)) {
2186 if (type == OP_RCATLINE)
5668452f 2187 SvPV_force_nomg_nolen(sv);
48de12d9
RGS
2188 else
2189 sv_unref(sv);
2190 }
f7877b28 2191 else if (isGV_with_GP(sv)) {
5668452f 2192 SvPV_force_nomg_nolen(sv);
f7877b28 2193 }
862a34c6 2194 SvUPGRADE(sv, SVt_PV);
a0d0e21e 2195 tmplen = SvLEN(sv); /* remember if already alloced */
e3918bb7 2196 if (!tmplen && !SvREADONLY(sv) && !SvIsCOW(sv)) {
f72e8700
JJ
2197 /* try short-buffering it. Please update t/op/readline.t
2198 * if you change the growth length.
2199 */
2200 Sv_Grow(sv, 80);
2201 }
2b5e58c4
AMS
2202 offset = 0;
2203 if (type == OP_RCATLINE && SvOK(sv)) {
2204 if (!SvPOK(sv)) {
5668452f 2205 SvPV_force_nomg_nolen(sv);
2b5e58c4 2206 }
a0d0e21e 2207 offset = SvCUR(sv);
2b5e58c4 2208 }
a0d0e21e 2209 }
54310121 2210 else {
561b68a9 2211 sv = sv_2mortal(newSV(80));
54310121
PP
2212 offset = 0;
2213 }
fbad3eb5 2214
3887d568
AP
2215 /* This should not be marked tainted if the fp is marked clean */
2216#define MAYBE_TAINT_LINE(io, sv) \
2217 if (!(IoFLAGS(io) & IOf_UNTAINT)) { \
2218 TAINT; \
2219 SvTAINTED_on(sv); \
2220 }
2221
684bef36 2222/* delay EOF state for a snarfed empty file */
fbad3eb5 2223#define SNARF_EOF(gimme,rs,io,sv) \
684bef36 2224 (gimme != G_SCALAR || SvCUR(sv) \
b9fee9ba 2225 || (IoFLAGS(io) & IOf_NOLINE) || !RsSNARF(rs))
fbad3eb5 2226
a0d0e21e 2227 for (;;) {
09e8efcc 2228 PUTBACK;
fbad3eb5 2229 if (!sv_gets(sv, fp, offset)
2d726892
TF
2230 && (type == OP_GLOB
2231 || SNARF_EOF(gimme, PL_rs, io, sv)
2232 || PerlIO_error(fp)))
fbad3eb5 2233 {
760ac839 2234 PerlIO_clearerr(fp);
a0d0e21e 2235 if (IoFLAGS(io) & IOf_ARGV) {
157fb5a1 2236 fp = nextargv(PL_last_in_gv, PL_op->op_flags & OPf_SPECIAL);
a0d0e21e
LW
2237 if (fp)
2238 continue;
3280af22 2239 (void)do_close(PL_last_in_gv, FALSE);
a0d0e21e
LW
2240 }
2241 else if (type == OP_GLOB) {
a2a5de95
NC
2242 if (!do_close(PL_last_in_gv, FALSE)) {
2243 Perl_ck_warner(aTHX_ packWARN(WARN_GLOB),
2244 "glob failed (child exited with status %d%s)",
2245 (int)(STATUS_CURRENT >> 8),
2246 (STATUS_CURRENT & 0x80) ? ", core dumped" : "");
4eb79ab5 2247 }
a0d0e21e 2248 }
54310121 2249 if (gimme == G_SCALAR) {
ba92458f
AE
2250 if (type != OP_RCATLINE) {
2251 SV_CHECK_THINKFIRST_COW_DROP(TARG);
0c34ef67 2252 SvOK_off(TARG);
ba92458f 2253 }
09e8efcc 2254 SPAGAIN;
a0d0e21e
LW
2255 PUSHTARG;
2256 }
3887d568 2257 MAYBE_TAINT_LINE(io, sv);
a0d0e21e
LW
2258 RETURN;
2259 }
3887d568 2260 MAYBE_TAINT_LINE(io, sv);
a0d0e21e 2261 IoLINES(io)++;
b9fee9ba 2262 IoFLAGS(io) |= IOf_NOLINE;
71be2cbc 2263 SvSETMAGIC(sv);
09e8efcc 2264 SPAGAIN;
a0d0e21e 2265 XPUSHs(sv);
a0d0e21e 2266 if (type == OP_GLOB) {
349d4f2f 2267 const char *t1;
45a23732 2268 Stat_t statbuf;
a0d0e21e 2269
3280af22 2270 if (SvCUR(sv) > 0 && SvCUR(PL_rs) > 0) {
6136c704 2271 char * const tmps = SvEND(sv) - 1;
aa07b2f6 2272 if (*tmps == *SvPVX_const(PL_rs)) {
c07a80fd 2273 *tmps = '\0';
b162af07 2274 SvCUR_set(sv, SvCUR(sv) - 1);
c07a80fd
PP
2275 }
2276 }
349d4f2f 2277 for (t1 = SvPVX_const(sv); *t1; t1++)
b51c3e77
CB
2278#ifdef __VMS
2279 if (strchr("*%?", *t1))
2280#else
7ad1e72d 2281 if (strchr("$&*(){}[]'\";\\|?<>~`", *t1))
b51c3e77 2282#endif
a0d0e21e 2283 break;
45a23732 2284 if (*t1 && PerlLIO_lstat(SvPVX_const(sv), &statbuf) < 0) {
a0d0e21e
LW
2285 (void)POPs; /* Unmatched wildcard? Chuck it... */
2286 continue;
2287 }
2d79bf7f 2288 } else if (SvUTF8(sv)) { /* OP_READLINE, OP_RCATLINE */
d4c19fe8
AL
2289 if (ckWARN(WARN_UTF8)) {
2290 const U8 * const s = (const U8*)SvPVX_const(sv) + offset;
2291 const STRLEN len = SvCUR(sv) - offset;
2292 const U8 *f;
2293
2294 if (!is_utf8_string_loc(s, len, &f))
2295 /* Emulate :encoding(utf8) warning in the same case. */
2296 Perl_warner(aTHX_ packWARN(WARN_UTF8),
2297 "utf8 \"\\x%02X\" does not map to Unicode",
2298 f < (U8*)SvEND(sv) ? *f : 0);
2299 }
a0d0e21e 2300 }
54310121 2301 if (gimme == G_ARRAY) {
a0d0e21e 2302 if (SvLEN(sv) - SvCUR(sv) > 20) {
1da4ca5f 2303 SvPV_shrink_to_cur(sv);
a0d0e21e 2304 }
561b68a9 2305 sv = sv_2mortal(newSV(80));
a0d0e21e
LW
2306 continue;
2307 }
54310121 2308 else if (gimme == G_SCALAR && !tmplen && SvLEN(sv) - SvCUR(sv) > 80) {
a0d0e21e 2309 /* try to reclaim a bit of scalar space (only on 1st alloc) */
d5b5861b
NC
2310 const STRLEN new_len
2311 = SvCUR(sv) < 60 ? 80 : SvCUR(sv)+40; /* allow some slop */
1da4ca5f 2312 SvPV_renew(sv, new_len);
a0d0e21e
LW
2313 }
2314 RETURN;
2315 }
2316}
2317
a0d0e21e
LW
2318PP(pp_helem)
2319{
20b7effb 2320 dSP;
760ac839 2321 HE* he;
ae77835f 2322 SV **svp;
c445ea15 2323 SV * const keysv = POPs;
85fbaab2 2324 HV * const hv = MUTABLE_HV(POPs);
a3b680e6
AL
2325 const U32 lval = PL_op->op_flags & OPf_MOD || LVRET;
2326 const U32 defer = PL_op->op_private & OPpLVAL_DEFER;
be6c24e0 2327 SV *sv;
92970b93 2328 const bool localizing = PL_op->op_private & OPpLVAL_INTRO;
d30e492c 2329 bool preeminent = TRUE;
a0d0e21e 2330
6dfc73ea
SM
2331 if (SvTYPE(hv) != SVt_PVHV)
2332 RETPUSHUNDEF;
d4c19fe8 2333
92970b93 2334 if (localizing) {
d4c19fe8
AL
2335 MAGIC *mg;
2336 HV *stash;
d30e492c
VP
2337
2338 /* If we can determine whether the element exist,
2339 * Try to preserve the existenceness of a tied hash
2340 * element by using EXISTS and DELETE if possible.
2341 * Fallback to FETCH and STORE otherwise. */
2c5f48c2 2342 if (SvCANEXISTDELETE(hv))
d30e492c 2343 preeminent = hv_exists_ent(hv, keysv, 0);
d4c19fe8 2344 }
d30e492c 2345
5f9d7e2b 2346 he = hv_fetch_ent(hv, keysv, lval && !defer, 0);
d4c19fe8 2347 svp = he ? &HeVAL(he) : NULL;
a0d0e21e 2348 if (lval) {
746f6409 2349 if (!svp || !*svp || *svp == &PL_sv_undef) {
68dc0745
PP
2350 SV* lv;
2351 SV* key2;
2d8e6c8d 2352 if (!defer) {
be2597df 2353 DIE(aTHX_ PL_no_helem_sv, SVfARG(keysv));
2d8e6c8d 2354 }
68dc0745
PP
2355 lv = sv_newmortal();
2356 sv_upgrade(lv, SVt_PVLV);
2357 LvTYPE(lv) = 'y';
6136c704 2358 sv_magic(lv, key2 = newSVsv(keysv), PERL_MAGIC_defelem, NULL, 0);
fc2b2dca 2359 SvREFCNT_dec_NN(key2); /* sv_magic() increments refcount */
0ad694a7 2360 LvTARG(lv) = SvREFCNT_inc_simple_NN(hv);
68dc0745
PP
2361 LvTARGLEN(lv) = 1;
2362 PUSHs(lv);
2363 RETURN;
2364 }
92970b93 2365 if (localizing) {
bfcb3514 2366 if (HvNAME_get(hv) && isGV(*svp))
159b6efe 2367 save_gp(MUTABLE_GV(*svp), !(PL_op->op_flags & OPf_SPECIAL));
47cfc530
VP
2368 else if (preeminent)
2369 save_helem_flags(hv, keysv, svp,
2370 (PL_op->op_flags & OPf_SPECIAL) ? 0 : SAVEf_SETMAGIC);
2371 else
2372 SAVEHDELETE(hv, keysv);
5f05dabc 2373 }
9026059d
GG
2374 else if (PL_op->op_private & OPpDEREF) {
2375 PUSHs(vivify_ref(*svp, PL_op->op_private & OPpDEREF));
2376 RETURN;
2377 }
a0d0e21e 2378 }
746f6409 2379 sv = (svp && *svp ? *svp : &PL_sv_undef);
fd69380d
DM
2380 /* Originally this did a conditional C<sv = sv_mortalcopy(sv)>; this
2381 * was to make C<local $tied{foo} = $tied{foo}> possible.
2382 * However, it seems no longer to be needed for that purpose, and
2383 * introduced a new bug: stuff like C<while ($hash{taintedval} =~ /.../g>
2384 * would loop endlessly since the pos magic is getting set on the
2385 * mortal copy and lost. However, the copy has the effect of
2386 * triggering the get magic, and losing it altogether made things like
2387 * c<$tied{foo};> in void context no longer do get magic, which some
2388 * code relied on. Also, delayed triggering of magic on @+ and friends
2389 * meant the original regex may be out of scope by now. So as a
2390 * compromise, do the get magic here. (The MGf_GSKIP flag will stop it
2391 * being called too many times). */
39cf747a 2392 if (!lval && SvRMAGICAL(hv) && SvGMAGICAL(sv))
fd69380d 2393 mg_get(sv);
be6c24e0 2394 PUSHs(sv);
a0d0e21e
LW
2395 RETURN;
2396}
2397
fedf30e1
DM
2398
2399/* a stripped-down version of Perl_softref2xv() for use by
2400 * pp_multideref(), which doesn't use PL_op->op_flags */
2401
f9db5646 2402STATIC GV *
fedf30e1
DM
2403S_softref2xv_lite(pTHX_ SV *const sv, const char *const what,
2404 const svtype type)
2405{
2406 if (PL_op->op_private & HINT_STRICT_REFS) {
2407 if (SvOK(sv))
2408 Perl_die(aTHX_ PL_no_symref_sv, sv,
2409 (SvPOKp(sv) && SvCUR(sv)>32 ? "..." : ""), what);
2410 else
2411 Perl_die(aTHX_ PL_no_usym, what);
2412 }
2413 if (!SvOK(sv))
2414 Perl_die(aTHX_ PL_no_usym, what);
2415 return gv_fetchsv_nomg(sv, GV_ADD, type);
2416}
2417
2418
79815f56
DM
2419/* Handle one or more aggregate derefs and array/hash indexings, e.g.
2420 * $h->{foo} or $a[0]{$key}[$i] or f()->[1]
fedf30e1
DM
2421 *
2422 * op_aux points to an array of unions of UV / IV / SV* / PADOFFSET.
79815f56
DM
2423 * Each of these either contains a set of actions, or an argument, such as
2424 * an IV to use as an array index, or a lexical var to retrieve.
2425 * Several actions re stored per UV; we keep shifting new actions off the
2426 * one UV, and only reload when it becomes zero.
fedf30e1
DM
2427 */
2428
2429PP(pp_multideref)
2430{
2431 SV *sv = NULL; /* init to avoid spurious 'may be used uninitialized' */
2432 UNOP_AUX_item *items = cUNOP_AUXx(PL_op)->op_aux;
2433 UV actions = items->uv;
2434
2435 assert(actions);
2436 /* this tells find_uninit_var() where we're up to */
2437 PL_multideref_pc = items;
2438
2439 while (1) {
2440 /* there are three main classes of action; the first retrieve
2441 * the initial AV or HV from a variable or the stack; the second
2442 * does the equivalent of an unrolled (/DREFAV, rv2av, aelem),
2443 * the third an unrolled (/DREFHV, rv2hv, helem).
2444 */
2445 switch (actions & MDEREF_ACTION_MASK) {
2446
2447 case MDEREF_reload:
2448 actions = (++items)->uv;
2449 continue;
2450
2451 case MDEREF_AV_padav_aelem: /* $lex[...] */
2452 sv = PAD_SVl((++items)->pad_offset);
2453 goto do_AV_aelem;
2454
2455 case MDEREF_AV_gvav_aelem: /* $pkg[...] */
2456 sv = UNOP_AUX_item_sv(++items);
2457 assert(isGV_with_GP(sv));
2458 sv = (SV*)GvAVn((GV*)sv);
2459 goto do_AV_aelem;
2460
2461 case MDEREF_AV_pop_rv2av_aelem: /* expr->[...] */
2462 {
2463 dSP;
2464 sv = POPs;
2465 PUTBACK;
2466 goto do_AV_rv2av_aelem;
2467 }
2468
2469 case MDEREF_AV_gvsv_vivify_rv2av_aelem: /* $pkg->[...] */
2470 sv = UNOP_AUX_item_sv(++items);
2471 assert(isGV_with_GP(sv));
2472 sv = GvSVn((GV*)sv);
2473 goto do_AV_vivify_rv2av_aelem;
2474
2475 case MDEREF_AV_padsv_vivify_rv2av_aelem: /* $lex->[...] */
2476 sv = PAD_SVl((++items)->pad_offset);
2477 /* FALLTHROUGH */
2478
2479 do_AV_vivify_rv2av_aelem:
2480 case MDEREF_AV_vivify_rv2av_aelem: /* vivify, ->[...] */
2481 /* this is the OPpDEREF action normally found at the end of
2482 * ops like aelem, helem, rv2sv */
2483 sv = vivify_ref(sv, OPpDEREF_AV);
2484 /* FALLTHROUGH */
2485
2486 do_AV_rv2av_aelem:
2487 /* this is basically a copy of pp_rv2av when it just has the
2488 * sKR/1 flags */
2489 SvGETMAGIC(sv);
2490 if (LIKELY(SvROK(sv))) {
2491 if (UNLIKELY(SvAMAGIC(sv))) {
2492 sv = amagic_deref_call(sv, to_av_amg);
2493 }
2494 sv = SvRV(sv);
2495 if (UNLIKELY(SvTYPE(sv) != SVt_PVAV))
2496 DIE(aTHX_ "Not an ARRAY reference");
2497 }
2498 else if (SvTYPE(sv) != SVt_PVAV) {
2499 if (!isGV_with_GP(sv))
2500 sv = (SV*)S_softref2xv_lite(aTHX_ sv, "an ARRAY", SVt_PVAV);
2501 sv = MUTABLE_SV(GvAVn((GV*)sv));
2502 }
2503 /* FALLTHROUGH */
2504
2505 do_AV_aelem:
2506 {
2507 /* retrieve the key; this may be either a lexical or package
2508 * var (whose index/ptr is stored as an item) or a signed
2509 * integer constant stored as an item.
2510 */
2511 SV *elemsv;
2512 IV elem = 0; /* to shut up stupid compiler warnings */
2513
2514
2515 assert(SvTYPE(sv) == SVt_PVAV);
2516
2517 switch (actions & MDEREF_INDEX_MASK) {
2518 case MDEREF_INDEX_none:
2519 goto finish;
2520 case MDEREF_INDEX_const:
2521 elem = (++items)->iv;
2522 break;
2523 case MDEREF_INDEX_padsv:
2524 elemsv = PAD_SVl((++items)->pad_offset);
2525 goto check_elem;
2526 case MDEREF_INDEX_gvsv:
2527 elemsv = UNOP_AUX_item_sv(++items);
2528 assert(isGV_with_GP(elemsv));
2529 elemsv = GvSVn((GV*)elemsv);
2530 check_elem:
2531 if (UNLIKELY(SvROK(elemsv) && !SvGAMAGIC(elemsv)
2532 && ckWARN(WARN_MISC)))
2533 Perl_warner(aTHX_ packWARN(WARN_MISC),
2534 "Use of reference \"%"SVf"\" as array index",
2535 SVfARG(elemsv));
2536 /* the only time that S_find_uninit_var() needs this
2537 * is to determine which index value triggered the
2538 * undef warning. So just update it here. Note that
2539 * since we don't save and restore this var (e.g. for
2540 * tie or overload execution), its value will be
2541 * meaningless apart from just here */
2542 PL_multideref_pc = items;
2543 elem = SvIV(elemsv);
2544 break;
2545 }
2546
2547
2548 /* this is basically a copy of pp_aelem with OPpDEREF skipped */
2549
2550 if (!(actions & MDEREF_FLAG_last)) {
2551 SV** svp = av_fetch((AV*)sv, elem, 1);
2552 if (!svp || ! (sv=*svp))
2553 DIE(aTHX_ PL_no_aelem, elem);
2554 break;
2555 }
2556
2557 if (PL_op->op_private &
2558 (OPpMULTIDEREF_EXISTS|OPpMULTIDEREF_DELETE))
2559 {
2560 if (PL_op->op_private & OPpMULTIDEREF_EXISTS) {
2561 sv = av_exists((AV*)sv, elem) ? &PL_sv_yes : &PL_sv_no;
2562 }
2563 else {
2564 I32 discard = (GIMME_V == G_VOID) ? G_DISCARD : 0;
2565 sv = av_delete((AV*)sv, elem, discard);
2566 if (discard)
2567 return NORMAL;
2568 if (!sv)
2569 sv = &PL_sv_undef;
2570 }
2571 }
2572 else {
2573 const U32 lval = PL_op->op_flags & OPf_MOD || LVRET;
2574 const U32 defer = PL_op->op_private & OPpLVAL_DEFER;
2575 const bool localizing = PL_op->op_private & OPpLVAL_INTRO;
2576 bool preeminent = TRUE;
2577 AV *const av = (AV*)sv;
2578 SV** svp;
2579
2580 if (UNLIKELY(localizing)) {
2581 MAGIC *mg;
2582 HV *stash;
2583
2584 /* If we can determine whether the element exist,
2585 * Try to preserve the existenceness of a tied array
2586 * element by using EXISTS and DELETE if possible.
2587 * Fallback to FETCH and STORE otherwise. */
2588 if (SvCANEXISTDELETE(av))
2589 preeminent = av_exists(av, elem);
2590 }
2591
2592 svp = av_fetch(av, elem, lval && !defer);
2593
2594 if (lval) {
2595 if (!svp || !(sv = *svp)) {
2596 IV len;
2597 if (!defer)
2598 DIE(aTHX_ PL_no_aelem, elem);
2599 len = av_tindex(av);
2600 sv = sv_2mortal(newSVavdefelem(av,
2601 /* Resolve a negative index now, unless it points
2602 * before the beginning of the array, in which
2603 * case record it for error reporting in
2604 * magic_setdefelem. */
2605 elem < 0 && len + elem >= 0
2606 ? len + elem : elem, 1));
2607 }
2608 else {
2609 if (UNLIKELY(localizing)) {
2610 if (preeminent) {
2611 save_aelem(av, elem, svp);
2612 sv = *svp; /* may have changed */
2613 }
2614 else
2615 SAVEADELETE(av, elem);
2616 }
2617 }
2618 }
2619 else {
2620 sv = (svp ? *svp : &PL_sv_undef);
2621 /* see note in pp_helem() */
2622 if (SvRMAGICAL(av) && SvGMAGICAL(sv))
2623 mg_get(sv);
2624 }
2625 }
2626
2627 }
2628 finish:
2629 {
2630 dSP;
2631 XPUSHs(sv);
2632 RETURN;
2633 }
2634 /* NOTREACHED */
2635
2636
2637
2638
2639 case MDEREF_HV_padhv_helem: /* $lex{...} */
2640 sv = PAD_SVl((++items)->pad_offset);
2641 goto do_HV_helem;
2642
2643 case MDEREF_HV_gvhv_helem: /* $pkg{...} */
2644 sv = UNOP_AUX_item_sv(++items);
2645 assert(isGV_with_GP(sv));
2646 sv = (SV*)GvHVn((GV*)sv);
2647 goto do_HV_helem;
2648
2649 case MDEREF_HV_pop_rv2hv_helem: /* expr->{...} */
2650 {
2651 dSP;
2652 sv = POPs;
2653 PUTBACK;
2654 goto do_HV_rv2hv_helem;
2655 }
2656
2657 case MDEREF_HV_gvsv_vivify_rv2hv_helem: /* $pkg->{...} */
2658 sv = UNOP_AUX_item_sv(++items);
2659 assert(isGV_with_GP(sv));
2660 sv = GvSVn((GV*)sv);
2661 goto do_HV_vivify_rv2hv_helem;
2662
2663 case MDEREF_HV_padsv_vivify_rv2hv_helem: /* $lex->{...} */
2664 sv = PAD_SVl((++items)->pad_offset);
2665 /* FALLTHROUGH */
2666
2667 do_HV_vivify_rv2hv_helem:
2668 case MDEREF_HV_vivify_rv2hv_helem: /* vivify, ->{...} */
2669 /* this is the OPpDEREF action normally found at the end of
2670 * ops like aelem, helem, rv2sv */
2671 sv = vivify_ref(sv, OPpDEREF_HV);
2672 /* FALLTHROUGH */
2673
2674 do_HV_rv2hv_helem:
2675 /* this is basically a copy of pp_rv2hv when it just has the
2676 * sKR/1 flags (and pp_rv2hv is aliased to pp_rv2av) */
2677
2678 SvGETMAGIC(sv);
2679 if (LIKELY(SvROK(sv))) {
2680 if (UNLIKELY(SvAMAGIC(sv))) {
2681 sv = amagic_deref_call(sv, to_hv_amg);
2682 }
2683 sv = SvRV(sv);
2684 if (UNLIKELY(SvTYPE(sv) != SVt_PVHV))
2685 DIE(aTHX_ "Not a HASH reference");
2686 }
2687 else if (SvTYPE(sv) != SVt_PVHV) {
2688 if (!isGV_with_GP(sv))
2689 sv = (SV*)S_softref2xv_lite(aTHX_ sv, "a HASH", SVt_PVHV);
2690 sv = MUTABLE_SV(GvHVn((GV*)sv));
2691 }
2692 /* FALLTHROUGH */
2693
2694 do_HV_helem:
2695 {
2696 /* retrieve the key; this may be either a lexical / package
2697 * var or a string constant, whose index/ptr is stored as an
2698 * item
2699 */
2700 SV *keysv = NULL; /* to shut up stupid compiler warnings */
2701
2702 assert(SvTYPE(sv) == SVt_PVHV);
2703
2704 switch (actions & MDEREF_INDEX_MASK) {
2705 case MDEREF_INDEX_none:
2706 goto finish;
2707
2708 case MDEREF_INDEX_const:
2709 keysv = UNOP_AUX_item_sv(++items);
2710 break;
2711
2712 case MDEREF_INDEX_padsv:
2713 keysv = PAD_SVl((++items)->pad_offset);
2714 break;
2715
2716 case MDEREF_INDEX_gvsv:
2717 keysv = UNOP_AUX_item_sv(++items);
2718 keysv = GvSVn((GV*)keysv);
2719 break;
2720 }
2721
2722 /* see comment above about setting this var */
2723 PL_multideref_pc = items;
2724
2725
2726 /* ensure that candidate CONSTs have been HEKified */
2727 assert( ((actions & MDEREF_INDEX_MASK) != MDEREF_INDEX_const)
2728 || SvTYPE(keysv) >= SVt_PVMG
2729 || !SvOK(keysv)
2730 || SvROK(keysv)
2731 || SvIsCOW_shared_hash(keysv));
2732
2733 /* this is basically a copy of pp_helem with OPpDEREF skipped */
2734
2735 if (!(actions & MDEREF_FLAG_last)) {
2736 HE *he = hv_fetch_ent((HV*)sv, keysv, 1, 0);
2737 if (!he || !(sv=HeVAL(he)) || sv == &PL_sv_undef)
2738 DIE(aTHX_ PL_no_helem_sv, SVfARG(keysv));
2739 break;
2740 }
2741
2742 if (PL_op->op_private &
2743 (OPpMULTIDEREF_EXISTS|OPpMULTIDEREF_DELETE))
2744 {
2745 if (PL_op->op_private & OPpMULTIDEREF_EXISTS) {
2746 sv = hv_exists_ent((HV*)sv, keysv, 0)
2747 ? &PL_sv_yes : &PL_sv_no;
2748 }
2749 else {
2750 I32 discard = (GIMME_V == G_VOID) ? G_DISCARD : 0;
2751 sv = hv_delete_ent((HV*)sv, keysv, discard, 0);
2752 if (discard)
2753 return NORMAL;
2754 if (!sv)
2755 sv = &PL_sv_undef;
2756 }
2757 }
2758 else {
2759 const U32 lval = PL_op->op_flags & OPf_MOD || LVRET;
2760 const U32 defer = PL_op->op_private & OPpLVAL_DEFER;
2761 const bool localizing = PL_op->op_private & OPpLVAL_INTRO;
2762 bool preeminent = TRUE;
2763 SV **svp;
2764 HV * const hv = (HV*)sv;
2765 HE* he;
2766
2767 if (UNLIKELY(localizing)) {
2768 MAGIC *mg;
2769 HV *stash;
2770
2771 /* If we can determine whether the element exist,
2772 * Try to preserve the existenceness of a tied hash
2773 * element by using EXISTS and DELETE if possible.
2774 * Fallback to FETCH and STORE otherwise. */
2775 if (SvCANEXISTDELETE(hv))
2776 preeminent = hv_exists_ent(hv, keysv, 0);
2777 }
2778
2779 he = hv_fetch_ent(hv, keysv, lval && !defer, 0);
2780 svp = he ? &HeVAL(he) : NULL;
2781
2782
2783 if (lval) {
2784 if (!svp || !(sv = *svp) || sv == &PL_sv_undef) {
2785 SV* lv;
2786 SV* key2;
2787 if (!defer)
2788 DIE(aTHX_ PL_no_helem_sv, SVfARG(keysv));
2789 lv = sv_newmortal();
2790 sv_upgrade(lv, SVt_PVLV);
2791 LvTYPE(lv) = 'y';
2792 sv_magic(lv, key2 = newSVsv(keysv),
2793 PERL_MAGIC_defelem, NULL, 0);
2794 /* sv_magic() increments refcount */
2795 SvREFCNT_dec_NN(key2);
0ad694a7 2796 LvTARG(lv) = SvREFCNT_inc_simple_NN(hv);
fedf30e1
DM
2797 LvTARGLEN(lv) = 1;
2798 sv = lv;
2799 }
2800 else {
2801 if (localizing) {
2802 if (HvNAME_get(hv) && isGV(sv))
2803 save_gp(MUTABLE_GV(sv),
2804 !(PL_op->op_flags & OPf_SPECIAL));
2805 else if (preeminent) {
2806 save_helem_flags(hv, keysv, svp,
2807 (PL_op->op_flags & OPf_SPECIAL)
2808 ? 0 : SAVEf_SETMAGIC);
2809 sv = *svp; /* may have changed */
2810 }
2811 else
2812 SAVEHDELETE(hv, keysv);
2813 }
2814 }
2815 }
2816 else {
2817 sv = (svp && *svp ? *svp : &PL_sv_undef);
2818 /* see note in pp_helem() */
2819 if (SvRMAGICAL(hv) && SvGMAGICAL(sv))
2820 mg_get(sv);
2821 }
2822 }
2823 goto finish;
2824 }
2825
2826 } /* switch */
2827
2828 actions >>= MDEREF_SHIFT;
2829 } /* while */
2830 /* NOTREACHED */
2831}
2832
2833
a0d0e21e
LW
2834PP(pp_iter)
2835{
eb578fdb 2836 PERL_CONTEXT *cx;
7d6c2cef 2837 SV *oldsv;
1d7c1841 2838 SV **itersvp;
8a1f10dd 2839 SV *retsv;
a0d0e21e 2840
84f05d57
JH
2841 SV *sv;
2842 AV *av;
2843 IV ix;
2844 IV inc;
2845
4ebe6e95 2846 cx = CX_CUR();
1d7c1841 2847 itersvp = CxITERVAR(cx);
4b5c941e 2848 assert(itersvp);
a48ce6be
DM
2849
2850 switch (CxTYPE(cx)) {
17c91640 2851
b552b52c
DM
2852 case CXt_LOOP_LAZYSV: /* string increment */
2853 {
2854 SV* cur = cx->blk_loop.state_u.lazysv.cur;
2855 SV *end = cx->blk_loop.state_u.lazysv.end;
2856 /* If the maximum is !SvOK(), pp_enteriter substitutes PL_sv_no.
2857 It has SvPVX of "" and SvCUR of 0, which is what we want. */
2858 STRLEN maxlen = 0;
2859 const char *max = SvPV_const(end, maxlen);
5d9574c1 2860 if (UNLIKELY(SvNIOK(cur) || SvCUR(cur) > maxlen))
8a1f10dd 2861 goto retno;
b552b52c
DM
2862
2863 oldsv = *itersvp;
6d3ca00e
DM
2864 /* NB: on the first iteration, oldsv will have a ref count of at
2865 * least 2 (one extra from blk_loop.itersave), so the GV or pad
2866 * slot will get localised; on subsequent iterations the RC==1
2867 * optimisation may kick in and the SV will be reused. */
2868 if (oldsv && LIKELY(SvREFCNT(oldsv) == 1 && !SvMAGICAL(oldsv))) {
b552b52c
DM
2869 /* safe to reuse old SV */
2870 sv_setsv(oldsv, cur);
a48ce6be 2871 }
b552b52c
DM
2872 else
2873 {
2874 /* we need a fresh SV every time so that loop body sees a
2875 * completely new SV for closures/references to work as
2876 * they used to */
2877 *itersvp = newSVsv(cur);
6d3ca00e 2878 SvREFCNT_dec(oldsv);
b552b52c
DM
2879 }
2880 if (strEQ(SvPVX_const(cur), max))
2881 sv_setiv(cur, 0); /* terminate next time */
2882 else
2883 sv_inc(cur);
2884 break;
2885 }
a48ce6be 2886
fcef60b4
DM
2887 case CXt_LOOP_LAZYIV: /* integer increment */
2888 {
2889 IV cur = cx->blk_loop.state_u.lazyiv.cur;
5d9574c1 2890 if (UNLIKELY(cur > cx->blk_loop.state_u.lazyiv.end))
8a1f10dd 2891 goto retno;
7f61b687 2892
fcef60b4 2893 oldsv = *itersvp;
6d3ca00e
DM
2894 /* see NB comment above */
2895 if (oldsv && LIKELY(SvREFCNT(oldsv) == 1 && !SvMAGICAL(oldsv))) {
eaa5c2d6 2896 /* safe to reuse old SV */
47b96a1e
DM
2897
2898 if ( (SvFLAGS(oldsv) & (SVTYPEMASK|SVf_THINKFIRST|SVf_IVisUV))
2899 == SVt_IV)
2900 {
2901 /* Cheap SvIOK_only().
2902 * Assert that flags which SvIOK_only() would test or
2903 * clear can't be set, because we're SVt_IV */
2904 assert(!(SvFLAGS(oldsv) &
2905 (SVf_OOK|SVf_UTF8|(SVf_OK & ~(SVf_IOK|SVp_IOK)))));
2906 SvFLAGS(oldsv) |= (SVf_IOK|SVp_IOK);
2907 /* SvIV_set() where sv_any points to head */
2908 oldsv->sv_u.svu_iv = cur;
2909
2910 }
2911 else
2912 sv_setiv(oldsv, cur);
eaa5c2d6 2913 }
1c846c1f 2914 else
eaa5c2d6
GA
2915 {
2916 /* we need a fresh SV every time so that loop body sees a
2917 * completely new SV for closures/references to work as they
2918 * used to */
fcef60b4 2919 *itersvp = newSViv(cur);
6d3ca00e 2920 SvREFCNT_dec(oldsv);
eaa5c2d6 2921 }
a2309040 2922
5d9574c1 2923 if (UNLIKELY(cur == IV_MAX)) {
cdc1aa42
NC
2924 /* Handle end of range at IV_MAX */
2925 cx->blk_loop.state_u.lazyiv.end = IV_MIN;
2926 } else
2927 ++cx->blk_loop.state_u.lazyiv.cur;
a48ce6be 2928 break;
fcef60b4 2929 }
a48ce6be 2930
93661e56
DM
2931 case CXt_LOOP_LIST: /* for (1,2,3) */
2932
2933 assert(OPpITER_REVERSED == 2); /* so inc becomes -1 or 1 */
2934 inc = 1 - (PL_op->op_private & OPpITER_REVERSED);
2935 ix = (cx->blk_loop.state_u.stack.ix += inc);
2936 if (UNLIKELY(inc > 0
2937 ? ix > cx->blk_oldsp
2938 : ix <= cx->blk_loop.state_u.stack.basesp)
2939 )
8a1f10dd 2940 goto retno;
93661e56
DM
2941
2942 sv = PL_stack_base[ix];
2943 av = NULL;
2944 goto loop_ary_common;
2945
2946 case CXt_LOOP_ARY: /* for (@ary) */
2947
2948 av = cx->blk_loop.state_u.ary.ary;
2949 inc = 1 - (PL_op->op_private & OPpITER_REVERSED);
2950 ix = (cx->blk_loop.state_u.ary.ix += inc);
2951 if (UNLIKELY(inc > 0
2952 ? ix > AvFILL(av)
2953 : ix < 0)
2954 )
8a1f10dd 2955 goto retno;
de080daa 2956
9d1ee8e0 2957 if (UNLIKELY(SvRMAGICAL(av))) {
a8a20bb6
DM
2958 SV * const * const svp = av_fetch(av, ix, FALSE);
2959 sv = svp ? *svp : NULL;
2960 }
2961 else {
2962 sv = AvARRAY(av)[ix];
de080daa 2963 }
ef3e5ea9 2964
93661e56
DM
2965 loop_ary_common:
2966
d39c26a6
FC
2967 if (UNLIKELY(cx->cx_type & CXp_FOR_LVREF)) {
2968 SvSetMagicSV(*itersvp, sv);
2969 break;
2970 }
2971
5d9574c1
DM
2972 if (LIKELY(sv)) {
2973 if (UNLIKELY(SvIS_FREED(sv))) {
f38aa882
DM
2974 *itersvp = NULL;
2975 Perl_croak(aTHX_ "Use of freed value in iteration");
2976 }
60779a30 2977 if (SvPADTMP(sv)) {
8e079c2a 2978 sv = newSVsv(sv);
60779a30 2979 }
8e079c2a
FC
2980 else {
2981 SvTEMP_off(sv);
2982 SvREFCNT_inc_simple_void_NN(sv);
2983 }
de080daa 2984 }
93661e56 2985 else if (av) {
199f858d 2986 sv = newSVavdefelem(av, ix, 0);
de080daa 2987 }
a600f7e6
FC
2988 else
2989 sv = &PL_sv_undef;
a0d0e21e 2990
de080daa
DM
2991 oldsv = *itersvp;
2992 *itersvp = sv;
2993 SvREFCNT_dec(oldsv);
de080daa 2994 break;
a48ce6be
DM
2995
2996 default:
2997 DIE(aTHX_ "panic: pp_iter, type=%u", CxTYPE(cx));
2998 }
8a1f10dd
DM
2999
3000 retsv = &PL_sv_yes;
3001 if (0) {
3002 retno:
3003 retsv = &PL_sv_no;
3004 }
3005 /* pp_enteriter should have pre-extended the stack */
3006 assert(PL_stack_sp < PL_stack_max);
3007 *++PL_stack_sp =retsv;
3008
3009 return PL_op->op_next;
a0d0e21e
LW
3010}
3011
ef07e810
DM
3012/*
3013A description of how taint works in pattern matching and substitution.
3014
284167a5
SM
3015This is all conditional on NO_TAINT_SUPPORT not being defined. Under
3016NO_TAINT_SUPPORT, taint-related operations should become no-ops.
3017
4e19c54b 3018While the pattern is being assembled/concatenated and then compiled,
284167a5
SM
3019PL_tainted will get set (via TAINT_set) if any component of the pattern
3020is tainted, e.g. /.*$tainted/. At the end of pattern compilation,
3021the RXf_TAINTED flag is set on the pattern if PL_tainted is set (via
1738e041
DM
3022TAINT_get). It will also be set if any component of the pattern matches
3023based on locale-dependent behavior.
ef07e810 3024
0ab462a6
DM
3025When the pattern is copied, e.g. $r = qr/..../, the SV holding the ref to
3026the pattern is marked as tainted. This means that subsequent usage, such
284167a5
SM
3027as /x$r/, will set PL_tainted using TAINT_set, and thus RXf_TAINTED,
3028on the new pattern too.
ef07e810 3029
272d35c9 3030RXf_TAINTED_SEEN is used post-execution by the get magic code
ef07e810
DM
3031of $1 et al to indicate whether the returned value should be tainted.
3032It is the responsibility of the caller of the pattern (i.e. pp_match,
3033pp_subst etc) to set this flag for any other circumstances where $1 needs
3034to be tainted.
3035
3036The taint behaviour of pp_subst (and pp_substcont) is quite complex.
3037
3038There are three possible sources of taint
3039 * the source string
3040 * the pattern (both compile- and run-time, RXf_TAINTED / RXf_TAINTED_SEEN)
3041 * the replacement string (or expression under /e)
3042
3043There are four destinations of taint and they are affected by the sources
3044according to the rules below:
3045
3046 * the return value (not including /r):
3047 tainted by the source string and pattern, but only for the
3048 number-of-iterations case; boolean returns aren't tainted;
3049 * the modified string (or modified copy under /r):
3050 tainted by the source string, pattern, and replacement strings;
3051 * $1 et al:
3052 tainted by the pattern, and under 'use re "taint"', by the source
3053 string too;
3054 * PL_taint - i.e. whether subsequent code (e.g. in a /e block) is tainted:
3055 should always be unset before executing subsequent code.
3056
3057The overall action of pp_subst is:
3058
3059 * at the start, set bits in rxtainted indicating the taint status of
3060 the various sources.
3061
3062 * After each pattern execution, update the SUBST_TAINT_PAT bit in
3063 rxtainted if RXf_TAINTED_SEEN has been set, to indicate that the
3064 pattern has subsequently become tainted via locale ops.
3065
3066 * If control is being passed to pp_substcont to execute a /e block,
3067 save rxtainted in the CXt_SUBST block, for future use by
3068 pp_substcont.
3069
3070 * Whenever control is being returned to perl code (either by falling
3071 off the "end" of pp_subst/pp_substcont, or by entering a /e block),
3072 use the flag bits in rxtainted to make all the appropriate types of
0ab462a6
DM
3073 destination taint visible; e.g. set RXf_TAINTED_SEEN so that $1
3074 et al will appear tainted.
ef07e810
DM
3075
3076pp_match is just a simpler version of the above.
3077
3078*/
3079
a0d0e21e
LW
3080PP(pp_subst)
3081{
20b7effb 3082 dSP; dTARG;
eb578fdb 3083 PMOP *pm = cPMOP;
a0d0e21e 3084 PMOP *rpm = pm;
eb578fdb 3085 char *s;
a0d0e21e 3086 char *strend;
5c144d81 3087 const char *c;
a0d0e21e 3088 STRLEN clen;
3c6ef0a5
FC
3089 SSize_t iters = 0;
3090 SSize_t maxiters;
a0d0e21e 3091 bool once;
ef07e810
DM
3092 U8 rxtainted = 0; /* holds various SUBST_TAINT_* flag bits.
3093 See "how taint works" above */
a0d0e21e 3094 char *orig;
1ed74d04 3095 U8 r_flags;
eb578fdb 3096 REGEXP *rx = PM_GETRE(pm);
a0d0e21e
LW
3097 STRLEN len;
3098 int force_on_match = 0;
0bcc34c2 3099 const I32 oldsave = PL_savestack_ix;
792b2c16 3100 STRLEN slen;
26a74523 3101 bool doutf8 = FALSE; /* whether replacement is in utf8 */
db2c6cb3 3102#ifdef PERL_ANY_COW
106d9a13 3103 bool was_cow;
ed252734 3104#endif
a0714e2c 3105 SV *nsv = NULL;
b770e143 3106 /* known replacement string? */
eb578fdb 3107 SV *dstr = (pm->op_pmflags & PMf_CONST) ? POPs : NULL;
a0d0e21e 3108
f410a211
NC
3109 PERL_ASYNC_CHECK();
3110
533c011a 3111 if (PL_op->op_flags & OPf_STACKED)
a0d0e21e 3112 TARG = POPs;
6ffceeb7 3113 else if (ARGTARG)
59f00321 3114 GETTARGET;
a0d0e21e 3115 else {
54b9620d 3116 TARG = DEFSV;
a0d0e21e 3117 EXTEND(SP,1);
1c846c1f 3118 }
d9f424b2 3119
64534138 3120 SvGETMAGIC(TARG); /* must come before cow check */
db2c6cb3 3121#ifdef PERL_ANY_COW
106d9a13
DM
3122 /* note that a string might get converted to COW during matching */
3123 was_cow = cBOOL(SvIsCOW(TARG));
ed252734 3124#endif
d13a5d3b
TC
3125 if (!(rpm->op_pmflags & PMf_NONDESTRUCT)) {
3126#ifndef PERL_ANY_COW
3127 if (SvIsCOW(TARG))
3128 sv_force_normal_flags(TARG,0);
3129#endif
3130 if ((SvREADONLY(TARG)
3131 || ( ((SvTYPE(TARG) == SVt_PVGV && isGV_with_GP(TARG))
3132 || SvTYPE(TARG) > SVt_PVLV)
3133 && !(SvTYPE(TARG) == SVt_PVGV && SvFAKE(TARG)))))
3134 Perl_croak_no_modify();
3135 }
8ec5e241
NIS
3136 PUTBACK;
3137
6ac6605d
DM
3138 orig = SvPV_nomg(TARG, len);
3139 /* note we don't (yet) force the var into being a string; if we fail
92711104 3140 * to match, we leave as-is; on successful match however, we *will*
6ac6605d 3141 * coerce into a string, then repeat the match */
4499db73 3142 if (!SvPOKp(TARG) || SvTYPE(TARG) == SVt_PVGV || SvVOK(TARG))
a0d0e21e 3143 force_on_match = 1;
20be6587
DM
3144
3145 /* only replace once? */
3146 once = !(rpm->op_pmflags & PMf_GLOBAL);
3147
ef07e810 3148 /* See "how taint works" above */
284167a5 3149 if (TAINTING_get) {
20be6587
DM
3150 rxtainted = (
3151 (SvTAINTED(TARG) ? SUBST_TAINT_STR : 0)
284167a5 3152 | (RX_ISTAINTED(rx) ? SUBST_TAINT_PAT : 0)
20be6587
DM
3153 | ((pm->op_pmflags & PMf_RETAINT) ? SUBST_TAINT_RETAINT : 0)
3154 | ((once && !(rpm->op_pmflags & PMf_NONDESTRUCT))
3155 ? SUBST_TAINT_BOOLRET : 0));
3156 TAINT_NOT;
3157 }
a12c0f56 3158
a0d0e21e 3159 force_it:
6ac6605d
DM
3160 if (!pm || !orig)
3161 DIE(aTHX_ "panic: pp_subst, pm=%p, orig=%p", pm, orig);
a0d0e21e 3162
6ac6605d
DM
3163 strend = orig + len;
3164 slen = DO_UTF8(TARG) ? utf8_length((U8*)orig, (U8*)strend) : len;
792b2c16
JH
3165 maxiters = 2 * slen + 10; /* We can match twice at each
3166 position, once with zero-length,
3167 second time with non-zero. */
a0d0e21e 3168
794826f4
YO
3169 /* handle the empty pattern */
3170 if (!RX_PRELEN(rx) && PL_curpm && !ReANY(rx)->mother_re) {
5585e758
YO
3171 if (PL_curpm == PL_reg_curpm) {
3172 if (PL_curpm_under) {
3173 if (PL_curpm_under == PL_reg_curpm) {
3174 Perl_croak(aTHX_ "Infinite recursion via empty pattern");
3175 } else {
3176 pm = PL_curpm_under;
3177 }
3178 }
3179 } else {
3180 pm = PL_curpm;
3181 }
3182 rx = PM_GETRE(pm);
a0d0e21e 3183 }
6502e081 3184
6e240d0b 3185#ifdef PERL_SAWAMPERSAND
6502e081
DM
3186 r_flags = ( RX_NPARENS(rx)
3187 || PL_sawampersand
6502e081 3188 || (RX_EXTFLAGS(rx) & (RXf_EVAL_SEEN|RXf_PMf_KEEPCOPY))
5b0e71e9 3189 || (rpm->op_pmflags & PMf_KEEPCOPY)
6502e081
DM
3190 )
3191 ? REXEC_COPY_STR
3192 : 0;
6e240d0b
FC
3193#else
3194 r_flags = REXEC_COPY_STR;
3195#endif
7fba1cd6 3196
0395280b 3197 if (!CALLREGEXEC(rx, orig, strend, orig, 0, TARG, NULL, r_flags))
8b64c330 3198 {
5e79dfb9
DM
3199 SPAGAIN;
3200 PUSHs(rpm->op_pmflags & PMf_NONDESTRUCT ? TARG : &PL_sv_no);
3201 LEAVE_SCOPE(oldsave);
3202 RETURN;
3203 }
1754320d
FC
3204 PL_curpm = pm;
3205
71be2cbc 3206 /* known replacement string? */
f272994b 3207 if (dstr) {
8514a05a
JH
3208 /* replacement needing upgrading? */
3209 if (DO_UTF8(TARG) && !doutf8) {
db79b45b 3210 nsv = sv_newmortal();
4a176938 3211 SvSetSV(nsv, dstr);
8df0e7a2 3212 sv_utf8_upgrade(nsv);
5c144d81 3213 c = SvPV_const(nsv, clen);
4a176938
JH
3214 doutf8 = TRUE;
3215 }
3216 else {
5c144d81 3217 c = SvPV_const(dstr, clen);
4a176938 3218 doutf8 = DO_UTF8(dstr);
8514a05a 3219 }
bb933b9b
FC
3220
3221 if (SvTAINTED(dstr))
3222 rxtainted |= SUBST_TAINT_REPL;
f272994b
A
3223 }
3224 else {
6136c704 3225 c = NULL;
f272994b
A
3226 doutf8 = FALSE;
3227 }
3228
71be2cbc 3229 /* can do inplace substitution? */
ed252734 3230 if (c
db2c6cb3 3231#ifdef PERL_ANY_COW
106d9a13 3232 && !was_cow
ed252734 3233#endif
fbfb1899 3234 && (I32)clen <= RX_MINLENRET(rx)
9cefd268
FC
3235 && ( once
3236 || !(r_flags & REXEC_COPY_STR)
3237 || (!SvGMAGICAL(dstr) && !(RX_EXTFLAGS(rx) & RXf_EVAL_SEEN))
3238 )
dbc200c5 3239 && !(RX_EXTFLAGS(rx) & RXf_NO_INPLACE_SUBST)
8ca8a454
NC
3240 && (!doutf8 || SvUTF8(TARG))
3241 && !(rpm->op_pmflags & PMf_NONDESTRUCT))
8b030b38 3242 {
ec911639 3243
db2c6cb3 3244#ifdef PERL_ANY_COW
106d9a13 3245 /* string might have got converted to COW since we set was_cow */
ed252734 3246 if (SvIsCOW(TARG)) {
f7a8268c 3247 if (!force_on_match)
ed252734 3248 goto have_a_cow;
f7a8268c 3249 assert(SvVOK(TARG));
ed252734
NC
3250 }
3251#endif
71be2cbc 3252 if (force_on_match) {
6ac6605d
DM
3253 /* redo the first match, this time with the orig var
3254 * forced into being a string */
71be2cbc 3255 force_on_match = 0;
6ac6605d 3256 orig = SvPV_force_nomg(TARG, len);
71be2cbc
PP
3257 goto force_it;
3258 }
39b40493 3259
71be2cbc 3260 if (once) {
c67ab8f2 3261 char *d, *m;
20be6587
DM
3262 if (RX_MATCH_TAINTED(rx)) /* run time pattern taint, eg locale */
3263 rxtainted |= SUBST_TAINT_PAT;
07bc277f
NC
3264 m = orig + RX_OFFS(rx)[0].start;
3265 d = orig + RX_OFFS(rx)[0].end;
71be2cbc
PP
3266 s = orig;
3267 if (m - s > strend - d) { /* faster to shorten from end */
2ec7214c 3268 I32 i;
71be2cbc
PP
3269 if (clen) {
3270 Copy(c, m, clen, char);
3271 m += clen;
a0d0e21e 3272 }
71be2cbc
PP
3273 i = strend - d;
3274 if (i > 0) {
3275 Move(d, m, i, char);
3276 m += i;
a0d0e21e 3277 }
71be2cbc
PP
3278 *m = '\0';
3279 SvCUR_set(TARG, m - s);
3280 }
2ec7214c
DM
3281 else { /* faster from front */
3282 I32 i = m - s;
71be2cbc 3283 d -= clen;
2ec7214c
DM
3284 if (i > 0)
3285 Move(s, d - i, i, char);
71be2cbc 3286 sv_chop(TARG, d-i);
71be2cbc 3287 if (clen)
c947cd8d 3288 Copy(c, d, clen, char);
71be2cbc 3289 }
8ec5e241 3290 SPAGAIN;
8ca8a454 3291 PUSHs(&PL_sv_yes);
71be2cbc
PP
3292 }
3293 else {
c67ab8f2 3294 char *d, *m;
0395280b 3295 d = s = RX_OFFS(rx)[0].start + orig;
71be2cbc 3296 do {
2b25edcf 3297 I32 i;
5d9574c1 3298 if (UNLIKELY(iters++ > maxiters))
cea2e8a9 3299 DIE(aTHX_ "Substitution loop");
5d9574c1 3300 if (UNLIKELY(RX_MATCH_TAINTED(rx))) /* run time pattern taint, eg locale */
20be6587 3301 rxtainted |= SUBST_TAINT_PAT;
07bc277f 3302 m = RX_OFFS(rx)[0].start + orig;
155aba94 3303 if ((i = m - s)) {
71be2cbc
PP
3304 if (s != d)
3305 Move(s, d, i, char);
3306 d += i;
a0d0e21e 3307 }
71be2cbc
PP
3308 if (clen) {
3309 Copy(c, d, clen, char);
3310 d += clen;
3311 }
07bc277f 3312 s = RX_OFFS(rx)[0].end + orig;
7ce41e5c
FC
3313 } while (CALLREGEXEC(rx, s, strend, orig,
3314 s == m, /* don't match same null twice */
f722798b 3315 TARG, NULL,
d5e7783a 3316 REXEC_NOT_FIRST|REXEC_IGNOREPOS|REXEC_FAIL_ON_UNDERFLOW));
71be2cbc 3317 if (s != d) {
2b25edcf 3318 I32 i = strend - s;
aa07b2f6 3319 SvCUR_set(TARG, d - SvPVX_const(TARG) + i);
71be2cbc 3320 Move(s, d, i+1, char); /* include the NUL */
a0d0e21e 3321 }
8ec5e241 3322 SPAGAIN;
3c6ef0a5 3323 mPUSHi(iters);
a0d0e21e
LW
3324 }
3325 }
ff6e92e8 3326 else {
1754320d 3327 bool first;
c67ab8f2 3328 char *m;
1754320d 3329 SV *repl;
a0d0e21e 3330 if (force_on_match) {
6ac6605d
DM
3331 /* redo the first match, this time with the orig var
3332 * forced into being a string */
a0d0e21e 3333 force_on_match = 0;
0c1438a1
NC
3334 if (rpm->op_pmflags & PMf_NONDESTRUCT) {
3335 /* I feel that it should be possible to avoid this mortal copy
3336 given that the code below copies into a new destination.
3337 However, I suspect it isn't worth the complexity of
3338 unravelling the C<goto force_it> for the small number of
3339 cases where it would be viable to drop into the copy code. */
3340 TARG = sv_2mortal(newSVsv(TARG));
3341 }
6ac6605d 3342 orig = SvPV_force_nomg(TARG, len);
a0d0e21e
LW
3343 goto force_it;
3344 }
db2c6cb3 3345#ifdef PERL_ANY_COW
ed252734
NC
3346 have_a_cow:
3347#endif
20be6587
DM
3348 if (RX_MATCH_TAINTED(rx)) /* run time pattern taint, eg locale */
3349 rxtainted |= SUBST_TAINT_PAT;
1754320d 3350 repl = dstr;
0395280b
DM
3351 s = RX_OFFS(rx)[0].start + orig;
3352 dstr = newSVpvn_flags(orig, s-orig,
3353 SVs_TEMP | (DO_UTF8(TARG) ? SVf_UTF8 : 0));
a0d0e21e 3354 if (!c) {
eb578fdb 3355 PERL_CONTEXT *cx;
8ec5e241 3356 SPAGAIN;
0395280b 3357 m = orig;
20be6587
DM
3358 /* note that a whole bunch of local vars are saved here for
3359 * use by pp_substcont: here's a list of them in case you're
3360 * searching for places in this sub that uses a particular var:
3361 * iters maxiters r_flags oldsave rxtainted orig dstr targ
3362 * s m strend rx once */
490576d1 3363 CX_PUSHSUBST(cx);
20e98b0f 3364 RETURNOP(cPMOP->op_pmreplrootu.op_pmreplroot);
a0d0e21e 3365 }
1754320d 3366 first = TRUE;
a0d0e21e 3367 do {
5d9574c1 3368 if (UNLIKELY(iters++ > maxiters))
cea2e8a9 3369 DIE(aTHX_ "Substitution loop");
5d9574c1 3370 if (UNLIKELY(RX_MATCH_TAINTED(rx)))
20be6587 3371 rxtainted |= SUBST_TAINT_PAT;
07bc277f 3372 if (RX_MATCH_COPIED(rx) && RX_SUBBEG(rx) != orig) {
c67ab8f2
DM
3373 char *old_s = s;
3374 char *old_orig = orig;
6502e081 3375 assert(RX_SUBOFFSET(rx) == 0);
c67ab8f2 3376
07bc277f 3377 orig = RX_SUBBEG(rx);
c67ab8f2
DM
3378 s = orig + (old_s - old_orig);
3379 strend = s + (strend - old_s);
a0d0e21e 3380 }
07bc277f 3381 m = RX_OFFS(rx)[0].start + orig;
64534138 3382 sv_catpvn_nomg_maybeutf8(dstr, s, m - s, DO_UTF8(TARG));
07bc277f 3383 s = RX_OFFS(rx)[0].end + orig;
1754320d
FC
3384 if (first) {
3385 /* replacement already stringified */
3386 if (clen)
64534138 3387 sv_catpvn_nomg_maybeutf8(dstr, c, clen, doutf8);
1754320d
FC
3388 first = FALSE;
3389 }
3390 else {
8df0e7a2 3391 sv_catsv(dstr, repl);
5d9574c1 3392 if (UNLIKELY(SvTAINTED(repl)))
bb933b9b 3393 rxtainted |= SUBST_TAINT_REPL;
1754320d 3394 }
a0d0e21e
LW
3395 if (once)
3396 break;
ff27773b
KW
3397 } while (CALLREGEXEC(rx, s, strend, orig,
3398 s == m, /* Yields minend of 0 or 1 */
d5e7783a
DM
3399 TARG, NULL,
3400 REXEC_NOT_FIRST|REXEC_IGNOREPOS|REXEC_FAIL_ON_UNDERFLOW));
aba224f7 3401 assert(strend >= s);
64534138 3402 sv_catpvn_nomg_maybeutf8(dstr, s, strend - s, DO_UTF8(TARG));
748a9306 3403
8ca8a454
NC
3404 if (rpm->op_pmflags & PMf_NONDESTRUCT) {
3405 /* From here on down we're using the copy, and leaving the original
3406 untouched. */
3407 TARG = dstr;
3408 SPAGAIN;
3409 PUSHs(dstr);
3410 } else {
db2c6cb3 3411#ifdef PERL_ANY_COW
8ca8a454
NC
3412 /* The match may make the string COW. If so, brilliant, because
3413 that's just saved us one malloc, copy and free - the regexp has
3414 donated the old buffer, and we malloc an entirely new one, rather
3415 than the regexp malloc()ing a buffer and copying our original,
3416 only for us to throw it away here during the substitution. */
3417 if (SvIsCOW(TARG)) {
3418 sv_force_normal_flags(TARG, SV_COW_DROP_PV);
3419 } else
ed252734 3420#endif
8ca8a454
NC
3421 {
3422 SvPV_free(TARG);
3423 }
3424 SvPV_set(TARG, SvPVX(dstr));
3425 SvCUR_set(TARG, SvCUR(dstr));
3426 SvLEN_set(TARG, SvLEN(dstr));
64534138 3427 SvFLAGS(TARG) |= SvUTF8(dstr);
8ca8a454 3428 SvPV_set(dstr, NULL);
748a9306 3429
8ca8a454 3430 SPAGAIN;
3c6ef0a5 3431 mPUSHi(iters);
8ca8a454
NC
3432 }
3433 }
3434
3435 if (!(rpm->op_pmflags & PMf_NONDESTRUCT)) {
3436 (void)SvPOK_only_UTF8(TARG);
a0d0e21e 3437 }
20be6587 3438
ef07e810 3439 /* See "how taint works" above */
284167a5 3440 if (TAINTING_get) {
20be6587
DM
3441 if ((rxtainted & SUBST_TAINT_PAT) ||
3442 ((rxtainted & (SUBST_TAINT_STR|SUBST_TAINT_RETAINT)) ==
3443 (SUBST_TAINT_STR|SUBST_TAINT_RETAINT))
3444 )
3445 (RX_MATCH_TAINTED_on(rx)); /* taint $1 et al */
3446
3447 if (!(rxtainted & SUBST_TAINT_BOOLRET)
3448 && (rxtainted & (SUBST_TAINT_STR|SUBST_TAINT_PAT))
3449 )
3450 SvTAINTED_on(TOPs); /* taint return value */
3451 else
3452 SvTAINTED_off(TOPs); /* may have got tainted earlier */
3453
3454 /* needed for mg_set below */
284167a5
SM
3455 TAINT_set(
3456 cBOOL(rxtainted & (SUBST_TAINT_STR|SUBST_TAINT_PAT|SUBST_TAINT_REPL))
3457 );
20be6587
DM
3458 SvTAINT(TARG);
3459 }
3460 SvSETMAGIC(TARG); /* PL_tainted must be correctly set for this mg_set */
3461 TAINT_NOT;
f1a76097
DM
3462 LEAVE_SCOPE(oldsave);
3463 RETURN;
a0d0e21e
LW
3464}
3465
3466PP(pp_grepwhile)
3467{
20b7effb 3468 dSP;
a0d0e21e
LW
3469
3470 if (SvTRUEx(POPs))
3280af22
NIS
3471 PL_stack_base[PL_markstack_ptr[-1]++] = PL_stack_base[*PL_markstack_ptr];
3472 ++*PL_markstack_ptr;
b2a2a901 3473 FREETMPS;
d343c3ef 3474 LEAVE_with_name("grep_item"); /* exit inner scope */
a0d0e21e
LW
3475
3476 /* All done yet? */
5d9574c1 3477 if (UNLIKELY(PL_stack_base + *PL_markstack_ptr > SP)) {
a0d0e21e 3478 I32 items;
1c23e2bd 3479 const U8 gimme = GIMME_V;
a0d0e21e 3480
d343c3ef 3481 LEAVE_with_name("grep"); /* exit outer scope */
a0d0e21e 3482 (void)POPMARK; /* pop src */
3280af22 3483 items = --*PL_markstack_ptr - PL_markstack_ptr[-1];
a0d0e21e 3484 (void)POPMARK; /* pop dst */
3280af22 3485 SP = PL_stack_base + POPMARK; /* pop original mark */
54310121 3486 if (gimme == G_SCALAR) {
7cc47870
RGS
3487 dTARGET;
3488 XPUSHi(items);
a0d0e21e 3489 }
54310121
PP
3490 else if (gimme == G_ARRAY)
3491 SP += items;
a0d0e21e
LW
3492 RETURN;
3493 }
3494 else {
3495 SV *src;
3496
d343c3ef 3497 ENTER_with_name("grep_item"); /* enter inner scope */
1d7c1841 3498 SAVEVPTR(PL_curpm);
a0d0e21e 3499
6cae08a8 3500 src = PL_stack_base[TOPMARK];
60779a30 3501 if (SvPADTMP(src)) {
6cae08a8 3502 src = PL_stack_base[TOPMARK] = sv_mortalcopy(src);
a0ed822e
FC
3503 PL_tmps_floor++;
3504 }
a0d0e21e 3505 SvTEMP_off(src);
ffd49c98 3506 DEFSV_set(src);
a0d0e21e
LW
3507
3508 RETURNOP(cLOGOP->op_other);
3509 }
3510}
3511
799da9d7 3512/* leave_adjust_stacks():
f7a874b8 3513 *
e02ce34b
DM
3514 * Process a scope's return args (in the range from_sp+1 .. PL_stack_sp),
3515 * positioning them at to_sp+1 onwards, and do the equivalent of a
3516 * FREEMPS and TAINT_NOT.
3517 *
f7a874b8
DM
3518 * Not intended to be called in void context.
3519 *
799da9d7
DM
3520 * When leaving a sub, eval, do{} or other scope, the things that need
3521 * doing to process the return args are:
f7a874b8 3522 * * in scalar context, only return the last arg (or PL_sv_undef if none);
799da9d7
DM
3523 * * for the types of return that return copies of their args (such
3524 * as rvalue sub return), make a mortal copy of every return arg,
3525 * except where we can optimise the copy away without it being
3526 * semantically visible;
3527 * * make sure that the arg isn't prematurely freed; in the case of an
3528 * arg not copied, this may involve mortalising it. For example, in
f7a874b8
DM
3529 * C<sub f { my $x = ...; $x }>, $x would be freed when we do
3530 * CX_LEAVE_SCOPE(cx) unless it's protected or copied.
3531 *
799da9d7
DM
3532 * What condition to use when deciding whether to pass the arg through
3533 * or make a copy, is determined by the 'pass' arg; its valid values are:
3534 * 0: rvalue sub/eval exit
3535 * 1: other rvalue scope exit
3536 * 2: :lvalue sub exit in rvalue context
3537 * 3: :lvalue sub exit in lvalue context and other lvalue scope exits
3538 *
f7a874b8 3539 * There is a big issue with doing a FREETMPS. We would like to free any
799da9d7 3540 * temps created by the last statement which the sub executed, rather than
f7a874b8
DM
3541 * leaving them for the caller. In a situation where a sub call isn't
3542 * soon followed by a nextstate (e.g. nested recursive calls, a la
3543 * fibonacci()), temps can accumulate, causing memory and performance
3544 * issues.
3545 *
3546 * On the other hand, we don't want to free any TEMPs which are keeping
799da9d7
DM
3547 * alive any return args that we skipped copying; nor do we wish to undo
3548 * any mortalising done here.
f7a874b8
DM
3549 *
3550 * The solution is to split the temps stack frame into two, with a cut
3551 * point delineating the two halves. We arrange that by the end of this
3552 * function, all the temps stack frame entries we wish to keep are in the
799da9d7 3553 * range PL_tmps_floor+1.. tmps_base-1, while the ones to free now are in
f7a874b8
DM
3554 * the range tmps_base .. PL_tmps_ix. During the course of this
3555 * function, tmps_base starts off as PL_tmps_floor+1, then increases
3556 * whenever we find or create a temp that we know should be kept. In
3557 * general the stuff above tmps_base is undecided until we reach the end,
3558 * and we may need a sort stage for that.
3559 *
3560 * To determine whether a TEMP is keeping a return arg alive, every
3561 * arg that is kept rather than copied and which has the SvTEMP flag
3562 * set, has the flag temporarily unset, to mark it. At the end we scan
799da9d7 3563 * the temps stack frame above the cut for entries without SvTEMP and
f7a874b8 3564 * keep them, while turning SvTEMP on again. Note that if we die before
799da9d7 3565 * the SvTEMPs flags are set again, its safe: at worst, subsequent use of
f7a874b8
DM
3566 * those SVs may be slightly less efficient.
3567 *
3568 * In practice various optimisations for some common cases mean we can
3569 * avoid most of the scanning and swapping about with the temps stack.
3570 */
3571
799da9d7 3572void
1c23e2bd 3573Perl_leave_adjust_stacks(pTHX_ SV **from_sp, SV **to_sp, U8 gimme, int pass)
a0d0e21e 3574{
263e0548 3575 dVAR;
20b7effb 3576 dSP;
f7a874b8
DM
3577 SSize_t tmps_base; /* lowest index into tmps stack that needs freeing now */
3578 SSize_t nargs;
3579
799da9d7
DM
3580 PERL_ARGS_ASSERT_LEAVE_ADJUST_STACKS;
3581
f7a874b8
DM
3582 TAINT_NOT;
3583
3584 if (gimme == G_ARRAY) {
e02ce34b
DM
3585 nargs = SP - from_sp;
3586 from_sp++;
f7a874b8
DM
3587 }
3588 else {
3589 assert(gimme == G_SCALAR);
e02ce34b 3590 if (UNLIKELY(from_sp >= SP)) {
f7a874b8 3591 /* no return args */
e02ce34b 3592 assert(from_sp == SP);
f7a874b8
DM
3593 EXTEND(SP, 1);
3594 *++SP = &PL_sv_undef;
e02ce34b 3595 to_sp = SP;
f7a874b8
DM
3596 nargs = 0;
3597 }
3598 else {
3599 from_sp = SP;
3600 nargs = 1;
3601 }
3602 }
3603
3604 /* common code for G_SCALAR and G_ARRAY */
3605
3606 tmps_base = PL_tmps_floor + 1;
3607
3608 assert(nargs >= 0);
3609 if (nargs) {
3610 /* pointer version of tmps_base. Not safe across temp stack
3611 * reallocs. */
3612 SV **tmps_basep;
3613
3614 EXTEND_MORTAL(nargs); /* one big extend for worst-case scenario */
3615 tmps_basep = PL_tmps_stack + tmps_base;
f7a874b8
DM
3616
3617 /* process each return arg */
3618
3619 do {
3620 SV *sv = *from_sp++;
3621
3622 assert(PL_tmps_ix + nargs < PL_tmps_max);
3645bb38
DM
3623#ifdef DEBUGGING
3624 /* PADTMPs with container set magic shouldn't appear in the
3625 * wild. This assert is more important for pp_leavesublv(),
3626 * but by testing for it here, we're more likely to catch
3627 * bad cases (what with :lvalue subs not being widely
3628 * deployed). The two issues are that for something like
3629 * sub :lvalue { $tied{foo} }
3630 * or
3631 * sub :lvalue { substr($foo,1,2) }
3632 * pp_leavesublv() will croak if the sub returns a PADTMP,
3633 * and currently functions like pp_substr() return a mortal
3634 * rather than using their PADTMP when returning a PVLV.
3635 * This is because the PVLV will hold a ref to $foo,
3636 * so $foo would get delayed in being freed while
3637 * the PADTMP SV remained in the PAD.
3638 * So if this assert fails it means either:
3639 * 1) there is pp code similar to pp_substr that is
3640 * returning a PADTMP instead of a mortal, and probably
3641 * needs fixing, or
5d9c1c9a 3642 * 2) pp_leavesublv is making unwarranted assumptions
3645bb38
DM
3643 * about always croaking on a PADTMP
3644 */
3645 if (SvPADTMP(sv) && SvSMAGICAL(sv)) {
3646 MAGIC *mg;
3647 for (mg = SvMAGIC(sv); mg; mg = mg->mg_moremagic) {
3648 assert(PERL_MAGIC_TYPE_IS_VALUE_MAGIC(mg->mg_type));