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[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
a0d0e21e
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"]
a0d0e21e
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
a0d0e21e
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
a0d0e21e
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 ($lex1,@lex2,...) */
357
358PP(pp_padrange)
359{
20b7effb 360 dSP;
a7fd8ef6
DM
361 PADOFFSET base = PL_op->op_targ;
362 int count = (int)(PL_op->op_private) & OPpPADRANGE_COUNTMASK;
d5524600
DM
363 if (PL_op->op_flags & OPf_SPECIAL) {
364 /* fake the RHS of my ($x,$y,..) = @_ */
365 PUSHMARK(SP);
366 S_pushav(aTHX_ GvAVn(PL_defgv));
367 SPAGAIN;
368 }
369
a7fd8ef6
DM
370 /* note, this is only skipped for compile-time-known void cxt */
371 if ((PL_op->op_flags & OPf_WANT) != OPf_WANT_VOID) {
19742f39
AL
372 int i;
373
a7fd8ef6
DM
374 EXTEND(SP, count);
375 PUSHMARK(SP);
376 for (i = 0; i <count; i++)
377 *++SP = PAD_SV(base+i);
378 }
379 if (PL_op->op_private & OPpLVAL_INTRO) {
4e09461c
DM
380 SV **svp = &(PAD_SVl(base));
381 const UV payload = (UV)(
382 (base << (OPpPADRANGE_COUNTSHIFT + SAVE_TIGHT_SHIFT))
383 | (count << SAVE_TIGHT_SHIFT)
384 | SAVEt_CLEARPADRANGE);
19742f39
AL
385 int i;
386
6d59e610 387 STATIC_ASSERT_STMT(OPpPADRANGE_COUNTMASK + 1 == (1 << OPpPADRANGE_COUNTSHIFT));
d081a355
DM
388 assert((payload >> (OPpPADRANGE_COUNTSHIFT+SAVE_TIGHT_SHIFT))
389 == (Size_t)base);
a3444cc5
DM
390 {
391 dSS_ADD;
392 SS_ADD_UV(payload);
393 SS_ADD_END(1);
394 }
4e09461c 395
a7fd8ef6 396 for (i = 0; i <count; i++)
4e09461c 397 SvPADSTALE_off(*svp++); /* mark lexical as active */
a7fd8ef6
DM
398 }
399 RETURN;
400}
401
402
a0d0e21e
LW
403PP(pp_padsv)
404{
20b7effb 405 dSP;
6c28b496
DD
406 EXTEND(SP, 1);
407 {
408 OP * const op = PL_op;
409 /* access PL_curpad once */
410 SV ** const padentry = &(PAD_SVl(op->op_targ));
411 {
412 dTARG;
413 TARG = *padentry;
414 PUSHs(TARG);
415 PUTBACK; /* no pop/push after this, TOPs ok */
8ec5e241 416 }
6c28b496
DD
417 if (op->op_flags & OPf_MOD) {
418 if (op->op_private & OPpLVAL_INTRO)
419 if (!(op->op_private & OPpPAD_STATE))
420 save_clearsv(padentry);
421 if (op->op_private & OPpDEREF) {
8f90a16d
FC
422 /* TOPs is equivalent to TARG here. Using TOPs (SP) rather
423 than TARG reduces the scope of TARG, so it does not
424 span the call to save_clearsv, resulting in smaller
425 machine code. */
6c28b496
DD
426 TOPs = vivify_ref(TOPs, op->op_private & OPpDEREF);
427 }
428 }
429 return op->op_next;
4633a7c4 430 }
a0d0e21e
LW
431}
432
433PP(pp_readline)
434{
30901a8a
FC
435 dSP;
436 if (TOPs) {
437 SvGETMAGIC(TOPs);
fc99edcf 438 tryAMAGICunTARGETlist(iter_amg, 0);
30901a8a
FC
439 PL_last_in_gv = MUTABLE_GV(*PL_stack_sp--);
440 }
441 else PL_last_in_gv = PL_argvgv, PL_stack_sp--;
6e592b3a
BM
442 if (!isGV_with_GP(PL_last_in_gv)) {
443 if (SvROK(PL_last_in_gv) && isGV_with_GP(SvRV(PL_last_in_gv)))
159b6efe 444 PL_last_in_gv = MUTABLE_GV(SvRV(PL_last_in_gv));
8efb3254 445 else {
f5284f61 446 dSP;
ad64d0ec 447 XPUSHs(MUTABLE_SV(PL_last_in_gv));
f5284f61 448 PUTBACK;
897d3989 449 Perl_pp_rv2gv(aTHX);
159b6efe 450 PL_last_in_gv = MUTABLE_GV(*PL_stack_sp--);
84ee769f
FC
451 if (PL_last_in_gv == (GV *)&PL_sv_undef)
452 PL_last_in_gv = NULL;
453 else
454 assert(isGV_with_GP(PL_last_in_gv));
f5284f61
IZ
455 }
456 }
a0d0e21e
LW
457 return do_readline();
458}
459
460PP(pp_eq)
461{
20b7effb 462 dSP;
33efebe6
DM
463 SV *left, *right;
464
a42d0242 465 tryAMAGICbin_MG(eq_amg, AMGf_set|AMGf_numeric);
33efebe6
DM
466 right = POPs;
467 left = TOPs;
468 SETs(boolSV(
469 (SvIOK_notUV(left) && SvIOK_notUV(right))
470 ? (SvIVX(left) == SvIVX(right))
471 : ( do_ncmp(left, right) == 0)
472 ));
473 RETURN;
a0d0e21e
LW
474}
475
b1c05ba5 476
4c2c3128 477/* also used for: pp_i_preinc() */
b1c05ba5 478
a0d0e21e
LW
479PP(pp_preinc)
480{
4c2c3128
DM
481 SV *sv = *PL_stack_sp;
482
483 if (LIKELY(((sv->sv_flags &
484 (SVf_THINKFIRST|SVs_GMG|SVf_IVisUV|
485 SVf_IOK|SVf_NOK|SVf_POK|SVp_NOK|SVp_POK|SVf_ROK))
486 == SVf_IOK))
487 && SvIVX(sv) != IV_MAX)
488 {
489 SvIV_set(sv, SvIVX(sv) + 1);
490 }
491 else /* Do all the PERL_PRESERVE_IVUV and hard cases in sv_inc */
492 sv_inc(sv);
493 SvSETMAGIC(sv);
494 return NORMAL;
495}
496
497
498/* also used for: pp_i_predec() */
499
500PP(pp_predec)
501{
502 SV *sv = *PL_stack_sp;
503
504 if (LIKELY(((sv->sv_flags &
505 (SVf_THINKFIRST|SVs_GMG|SVf_IVisUV|
506 SVf_IOK|SVf_NOK|SVf_POK|SVp_NOK|SVp_POK|SVf_ROK))
507 == SVf_IOK))
508 && SvIVX(sv) != IV_MIN)
55497cff 509 {
4c2c3128 510 SvIV_set(sv, SvIVX(sv) - 1);
748a9306 511 }
4c2c3128
DM
512 else /* Do all the PERL_PRESERVE_IVUV and hard cases in sv_dec */
513 sv_dec(sv);
514 SvSETMAGIC(sv);
a0d0e21e
LW
515 return NORMAL;
516}
517
b1c05ba5
DM
518
519/* also used for: pp_orassign() */
520
a0d0e21e
LW
521PP(pp_or)
522{
20b7effb 523 dSP;
f410a211 524 PERL_ASYNC_CHECK();
a0d0e21e
LW
525 if (SvTRUE(TOPs))
526 RETURN;
527 else {
c960fc3b
SP
528 if (PL_op->op_type == OP_OR)
529 --SP;
a0d0e21e
LW
530 RETURNOP(cLOGOP->op_other);
531 }
532}
533
b1c05ba5
DM
534
535/* also used for: pp_dor() pp_dorassign() */
536
25a55bd7 537PP(pp_defined)
c963b151 538{
20b7effb 539 dSP;
eb578fdb 540 SV* sv;
6136c704 541 bool defined;
25a55bd7 542 const int op_type = PL_op->op_type;
ea5195b7 543 const bool is_dor = (op_type == OP_DOR || op_type == OP_DORASSIGN);
c963b151 544
6136c704 545 if (is_dor) {
f410a211 546 PERL_ASYNC_CHECK();
25a55bd7 547 sv = TOPs;
5d9574c1 548 if (UNLIKELY(!sv || !SvANY(sv))) {
2bd49cfc
NC
549 if (op_type == OP_DOR)
550 --SP;
25a55bd7
SP
551 RETURNOP(cLOGOP->op_other);
552 }
b7c44293
RGS
553 }
554 else {
555 /* OP_DEFINED */
25a55bd7 556 sv = POPs;
5d9574c1 557 if (UNLIKELY(!sv || !SvANY(sv)))
25a55bd7 558 RETPUSHNO;
b7c44293 559 }
25a55bd7 560
6136c704 561 defined = FALSE;
c963b151
BD
562 switch (SvTYPE(sv)) {
563 case SVt_PVAV:
564 if (AvMAX(sv) >= 0 || SvGMAGICAL(sv) || (SvRMAGICAL(sv) && mg_find(sv, PERL_MAGIC_tied)))
25a55bd7 565 defined = TRUE;
c963b151
BD
566 break;
567 case SVt_PVHV:
568 if (HvARRAY(sv) || SvGMAGICAL(sv) || (SvRMAGICAL(sv) && mg_find(sv, PERL_MAGIC_tied)))
25a55bd7 569 defined = TRUE;
c963b151
BD
570 break;
571 case SVt_PVCV:
572 if (CvROOT(sv) || CvXSUB(sv))
25a55bd7 573 defined = TRUE;
c963b151
BD
574 break;
575 default:
5b295bef 576 SvGETMAGIC(sv);
c963b151 577 if (SvOK(sv))
25a55bd7 578 defined = TRUE;
6136c704 579 break;
c963b151 580 }
6136c704
AL
581
582 if (is_dor) {
c960fc3b
SP
583 if(defined)
584 RETURN;
585 if(op_type == OP_DOR)
586 --SP;
25a55bd7 587 RETURNOP(cLOGOP->op_other);
25a55bd7 588 }
d9aa96a4
SP
589 /* assuming OP_DEFINED */
590 if(defined)
591 RETPUSHYES;
592 RETPUSHNO;
c963b151
BD
593}
594
230ee21f
DM
595
596
a0d0e21e
LW
597PP(pp_add)
598{
20b7effb 599 dSP; dATARGET; bool useleft; SV *svl, *svr;
230ee21f 600
6f1401dc
DM
601 tryAMAGICbin_MG(add_amg, AMGf_assign|AMGf_numeric);
602 svr = TOPs;
603 svl = TOPm1s;
604
28e5dec8 605#ifdef PERL_PRESERVE_IVUV
230ee21f
DM
606
607 /* special-case some simple common cases */
608 if (!((svl->sv_flags|svr->sv_flags) & (SVf_IVisUV|SVs_GMG))) {
609 IV il, ir;
610 U32 flags = (svl->sv_flags & svr->sv_flags);
611 if (flags & SVf_IOK) {
612 /* both args are simple IVs */
613 UV topl, topr;
614 il = SvIVX(svl);
615 ir = SvIVX(svr);
616 do_iv:
617 topl = ((UV)il) >> (UVSIZE * 8 - 2);
618 topr = ((UV)ir) >> (UVSIZE * 8 - 2);
619
620 /* if both are in a range that can't under/overflow, do a
621 * simple integer add: if the top of both numbers
622 * are 00 or 11, then it's safe */
623 if (!( ((topl+1) | (topr+1)) & 2)) {
624 SP--;
625 TARGi(il + ir, 0); /* args not GMG, so can't be tainted */
626 SETs(TARG);
627 RETURN;
628 }
629 goto generic;
630 }
631 else if (flags & SVf_NOK) {
632 /* both args are NVs */
633 NV nl = SvNVX(svl);
634 NV nr = SvNVX(svr);
635
3336af0b
DD
636 if (
637#if defined(NAN_COMPARE_BROKEN) && defined(Perl_isnan)
638 !Perl_isnan(nl) && nl == (NV)(il = (IV)nl)
639 && !Perl_isnan(nr) && nr == (NV)(ir = (IV)nr)
640#else
641 nl == (NV)(il = (IV)nl) && nr == (NV)(ir = (IV)nr)
642#endif
643 )
230ee21f
DM
644 /* nothing was lost by converting to IVs */
645 goto do_iv;
646 SP--;
647 TARGn(nl + nr, 0); /* args not GMG, so can't be tainted */
648 SETs(TARG);
649 RETURN;
650 }
651 }
652
653 generic:
654
655 useleft = USE_LEFT(svl);
28e5dec8
JH
656 /* We must see if we can perform the addition with integers if possible,
657 as the integer code detects overflow while the NV code doesn't.
658 If either argument hasn't had a numeric conversion yet attempt to get
659 the IV. It's important to do this now, rather than just assuming that
660 it's not IOK as a PV of "9223372036854775806" may not take well to NV
661 addition, and an SV which is NOK, NV=6.0 ought to be coerced to
662 integer in case the second argument is IV=9223372036854775806
663 We can (now) rely on sv_2iv to do the right thing, only setting the
664 public IOK flag if the value in the NV (or PV) slot is truly integer.
665
666 A side effect is that this also aggressively prefers integer maths over
7dca457a
NC
667 fp maths for integer values.
668
a00b5bd3 669 How to detect overflow?
7dca457a
NC
670
671 C 99 section 6.2.6.1 says
672
673 The range of nonnegative values of a signed integer type is a subrange
674 of the corresponding unsigned integer type, and the representation of
675 the same value in each type is the same. A computation involving
676 unsigned operands can never overflow, because a result that cannot be
677 represented by the resulting unsigned integer type is reduced modulo
678 the number that is one greater than the largest value that can be
679 represented by the resulting type.
680
681 (the 9th paragraph)
682
683 which I read as "unsigned ints wrap."
684
685 signed integer overflow seems to be classed as "exception condition"
686
687 If an exceptional condition occurs during the evaluation of an
688 expression (that is, if the result is not mathematically defined or not
689 in the range of representable values for its type), the behavior is
690 undefined.
691
692 (6.5, the 5th paragraph)
693
694 I had assumed that on 2s complement machines signed arithmetic would
695 wrap, hence coded pp_add and pp_subtract on the assumption that
696 everything perl builds on would be happy. After much wailing and
697 gnashing of teeth it would seem that irix64 knows its ANSI spec well,
698 knows that it doesn't need to, and doesn't. Bah. Anyway, the all-
699 unsigned code below is actually shorter than the old code. :-)
700 */
701
01f91bf2 702 if (SvIV_please_nomg(svr)) {
28e5dec8
JH
703 /* Unless the left argument is integer in range we are going to have to
704 use NV maths. Hence only attempt to coerce the right argument if
705 we know the left is integer. */
eb578fdb 706 UV auv = 0;
9c5ffd7c 707 bool auvok = FALSE;
7dca457a
NC
708 bool a_valid = 0;
709
28e5dec8 710 if (!useleft) {
7dca457a
NC
711 auv = 0;
712 a_valid = auvok = 1;
713 /* left operand is undef, treat as zero. + 0 is identity,
714 Could SETi or SETu right now, but space optimise by not adding
715 lots of code to speed up what is probably a rarish case. */
716 } else {
717 /* Left operand is defined, so is it IV? */
01f91bf2 718 if (SvIV_please_nomg(svl)) {
800401ee
JH
719 if ((auvok = SvUOK(svl)))
720 auv = SvUVX(svl);
7dca457a 721 else {
eb578fdb 722 const IV aiv = SvIVX(svl);
7dca457a
NC
723 if (aiv >= 0) {
724 auv = aiv;
725 auvok = 1; /* Now acting as a sign flag. */
53e2bfb7
DM
726 } else {
727 auv = (aiv == IV_MIN) ? (UV)aiv : (UV)(-aiv);
7dca457a
NC
728 }
729 }
730 a_valid = 1;
28e5dec8
JH
731 }
732 }
7dca457a
NC
733 if (a_valid) {
734 bool result_good = 0;
735 UV result;
eb578fdb 736 UV buv;
800401ee 737 bool buvok = SvUOK(svr);
a00b5bd3 738
7dca457a 739 if (buvok)
800401ee 740 buv = SvUVX(svr);
7dca457a 741 else {
eb578fdb 742 const IV biv = SvIVX(svr);
7dca457a
NC
743 if (biv >= 0) {
744 buv = biv;
745 buvok = 1;
746 } else
53e2bfb7 747 buv = (biv == IV_MIN) ? (UV)biv : (UV)(-biv);
7dca457a
NC
748 }
749 /* ?uvok if value is >= 0. basically, flagged as UV if it's +ve,
602f51c4 750 else "IV" now, independent of how it came in.
7dca457a
NC
751 if a, b represents positive, A, B negative, a maps to -A etc
752 a + b => (a + b)
753 A + b => -(a - b)
754 a + B => (a - b)
755 A + B => -(a + b)
756 all UV maths. negate result if A negative.
757 add if signs same, subtract if signs differ. */
758
759 if (auvok ^ buvok) {
760 /* Signs differ. */
761 if (auv >= buv) {
762 result = auv - buv;
763 /* Must get smaller */
764 if (result <= auv)
765 result_good = 1;
766 } else {
767 result = buv - auv;
768 if (result <= buv) {
769 /* result really should be -(auv-buv). as its negation
770 of true value, need to swap our result flag */
771 auvok = !auvok;
772 result_good = 1;
28e5dec8
JH
773 }
774 }
7dca457a
NC
775 } else {
776 /* Signs same */
777 result = auv + buv;
778 if (result >= auv)
779 result_good = 1;
780 }
781 if (result_good) {
782 SP--;
783 if (auvok)
28e5dec8 784 SETu( result );
7dca457a
NC
785 else {
786 /* Negate result */
787 if (result <= (UV)IV_MIN)
53e2bfb7
DM
788 SETi(result == (UV)IV_MIN
789 ? IV_MIN : -(IV)result);
7dca457a
NC
790 else {
791 /* result valid, but out of range for IV. */
792 SETn( -(NV)result );
28e5dec8
JH
793 }
794 }
7dca457a
NC
795 RETURN;
796 } /* Overflow, drop through to NVs. */
28e5dec8
JH
797 }
798 }
230ee21f
DM
799
800#else
801 useleft = USE_LEFT(svl);
28e5dec8 802#endif
230ee21f 803
a0d0e21e 804 {
6f1401dc 805 NV value = SvNV_nomg(svr);
4efa5a16 806 (void)POPs;
28e5dec8
JH
807 if (!useleft) {
808 /* left operand is undef, treat as zero. + 0.0 is identity. */
809 SETn(value);
810 RETURN;
811 }
6f1401dc 812 SETn( value + SvNV_nomg(svl) );
28e5dec8 813 RETURN;
a0d0e21e
LW
814 }
815}
816
b1c05ba5
DM
817
818/* also used for: pp_aelemfast_lex() */
819
a0d0e21e
LW
820PP(pp_aelemfast)
821{
20b7effb 822 dSP;
93bad3fd 823 AV * const av = PL_op->op_type == OP_AELEMFAST_LEX
8f878375 824 ? MUTABLE_AV(PAD_SV(PL_op->op_targ)) : GvAVn(cGVOP_gv);
a3b680e6 825 const U32 lval = PL_op->op_flags & OPf_MOD;
7e169e84
DM
826 const I8 key = (I8)PL_op->op_private;
827 SV** svp;
828 SV *sv;
829
830 assert(SvTYPE(av) == SVt_PVAV);
831
f4484b87
DM
832 EXTEND(SP, 1);
833
7e169e84
DM
834 /* inlined av_fetch() for simple cases ... */
835 if (!SvRMAGICAL(av) && key >= 0 && key <= AvFILLp(av)) {
836 sv = AvARRAY(av)[key];
9fb994be 837 if (sv) {
7e169e84
DM
838 PUSHs(sv);
839 RETURN;
840 }
841 }
842
843 /* ... else do it the hard way */
844 svp = av_fetch(av, key, lval);
845 sv = (svp ? *svp : &PL_sv_undef);
b024352e
DM
846
847 if (UNLIKELY(!svp && lval))
7e169e84 848 DIE(aTHX_ PL_no_aelem, (int)key);
b024352e 849
39cf747a 850 if (!lval && SvRMAGICAL(av) && SvGMAGICAL(sv)) /* see note in pp_helem() */
fd69380d 851 mg_get(sv);
be6c24e0 852 PUSHs(sv);
a0d0e21e
LW
853 RETURN;
854}
855
856PP(pp_join)
857{
20b7effb 858 dSP; dMARK; dTARGET;
a0d0e21e
LW
859 MARK++;
860 do_join(TARG, *MARK, MARK, SP);
861 SP = MARK;
862 SETs(TARG);
863 RETURN;
864}
865
a0d0e21e
LW
866/* Oversized hot code. */
867
b1c05ba5
DM
868/* also used for: pp_say() */
869
a0d0e21e
LW
870PP(pp_print)
871{
20b7effb 872 dSP; dMARK; dORIGMARK;
eb578fdb 873 PerlIO *fp;
236988e4 874 MAGIC *mg;
159b6efe
NC
875 GV * const gv
876 = (PL_op->op_flags & OPf_STACKED) ? MUTABLE_GV(*++MARK) : PL_defoutgv;
9c9f25b8 877 IO *io = GvIO(gv);
5b468f54 878
9c9f25b8 879 if (io
ad64d0ec 880 && (mg = SvTIED_mg((const SV *)io, PERL_MAGIC_tiedscalar)))
5b468f54 881 {
01bb7c6d 882 had_magic:
68dc0745 883 if (MARK == ORIGMARK) {
1c846c1f 884 /* If using default handle then we need to make space to
a60c0954
NIS
885 * pass object as 1st arg, so move other args up ...
886 */
4352c267 887 MEXTEND(SP, 1);
68dc0745
PP
888 ++MARK;
889 Move(MARK, MARK + 1, (SP - MARK) + 1, SV*);
890 ++SP;
891 }
3e0cb5de 892 return Perl_tied_method(aTHX_ SV_CONST(PRINT), mark - 1, MUTABLE_SV(io),
94bc412f
NC
893 mg,
894 (G_SCALAR | TIED_METHOD_ARGUMENTS_ON_STACK
895 | (PL_op->op_type == OP_SAY
896 ? TIED_METHOD_SAY : 0)), sp - mark);
236988e4 897 }
9c9f25b8 898 if (!io) {
68b590d9 899 if ( gv && GvEGVx(gv) && (io = GvIO(GvEGV(gv)))
ad64d0ec 900 && (mg = SvTIED_mg((const SV *)io, PERL_MAGIC_tiedscalar)))
01bb7c6d 901 goto had_magic;
51087808 902 report_evil_fh(gv);
93189314 903 SETERRNO(EBADF,RMS_IFI);
a0d0e21e
LW
904 goto just_say_no;
905 }
906 else if (!(fp = IoOFP(io))) {
7716c5c5
NC
907 if (IoIFP(io))
908 report_wrongway_fh(gv, '<');
51087808 909 else
7716c5c5 910 report_evil_fh(gv);
93189314 911 SETERRNO(EBADF,IoIFP(io)?RMS_FAC:RMS_IFI);
a0d0e21e
LW
912 goto just_say_no;
913 }
914 else {
e23d9e2f 915 SV * const ofs = GvSV(PL_ofsgv); /* $, */
a0d0e21e 916 MARK++;
e23d9e2f 917 if (ofs && (SvGMAGICAL(ofs) || SvOK(ofs))) {
a0d0e21e
LW
918 while (MARK <= SP) {
919 if (!do_print(*MARK, fp))
920 break;
921 MARK++;
922 if (MARK <= SP) {
e23d9e2f
CS
923 /* don't use 'ofs' here - it may be invalidated by magic callbacks */
924 if (!do_print(GvSV(PL_ofsgv), fp)) {
a0d0e21e
LW
925 MARK--;
926 break;
927 }
928 }
929 }
930 }
931 else {
932 while (MARK <= SP) {
933 if (!do_print(*MARK, fp))
934 break;
935 MARK++;
936 }
937 }
938 if (MARK <= SP)
939 goto just_say_no;
940 else {
cfc4a7da
GA
941 if (PL_op->op_type == OP_SAY) {
942 if (PerlIO_write(fp, "\n", 1) == 0 || PerlIO_error(fp))
943 goto just_say_no;
944 }
945 else if (PL_ors_sv && SvOK(PL_ors_sv))
7889fe52 946 if (!do_print(PL_ors_sv, fp)) /* $\ */
a0d0e21e
LW
947 goto just_say_no;
948
949 if (IoFLAGS(io) & IOf_FLUSH)
760ac839 950 if (PerlIO_flush(fp) == EOF)
a0d0e21e
LW
951 goto just_say_no;
952 }
953 }
954 SP = ORIGMARK;
e52fd6f4 955 XPUSHs(&PL_sv_yes);
a0d0e21e
LW
956 RETURN;
957
958 just_say_no:
959 SP = ORIGMARK;
e52fd6f4 960 XPUSHs(&PL_sv_undef);
a0d0e21e
LW
961 RETURN;
962}
963
b1c05ba5
DM
964
965/* also used for: pp_rv2hv() */
bdaf10a5 966/* also called directly by pp_lvavref */
b1c05ba5 967
a0d0e21e
LW
968PP(pp_rv2av)
969{
20b7effb 970 dSP; dTOPss;
1c23e2bd 971 const U8 gimme = GIMME_V;
13c59d41
MH
972 static const char an_array[] = "an ARRAY";
973 static const char a_hash[] = "a HASH";
bdaf10a5
FC
974 const bool is_pp_rv2av = PL_op->op_type == OP_RV2AV
975 || PL_op->op_type == OP_LVAVREF;
d83b45b8 976 const svtype type = is_pp_rv2av ? SVt_PVAV : SVt_PVHV;
a0d0e21e 977
9026059d 978 SvGETMAGIC(sv);
a0d0e21e 979 if (SvROK(sv)) {
5d9574c1 980 if (UNLIKELY(SvAMAGIC(sv))) {
93d7320b 981 sv = amagic_deref_call(sv, is_pp_rv2av ? to_av_amg : to_hv_amg);
93d7320b 982 }
17ab7946 983 sv = SvRV(sv);
5d9574c1 984 if (UNLIKELY(SvTYPE(sv) != type))
dcbac5bb 985 /* diag_listed_as: Not an ARRAY reference */
13c59d41 986 DIE(aTHX_ "Not %s reference", is_pp_rv2av ? an_array : a_hash);
5d9574c1
DM
987 else if (UNLIKELY(PL_op->op_flags & OPf_MOD
988 && PL_op->op_private & OPpLVAL_INTRO))
3da99855 989 Perl_croak(aTHX_ "%s", PL_no_localize_ref);
a0d0e21e 990 }
5d9574c1 991 else if (UNLIKELY(SvTYPE(sv) != type)) {
67955e0c 992 GV *gv;
1c846c1f 993
6e592b3a 994 if (!isGV_with_GP(sv)) {
13c59d41 995 gv = Perl_softref2xv(aTHX_ sv, is_pp_rv2av ? an_array : a_hash,
dc3c76f8
NC
996 type, &sp);
997 if (!gv)
998 RETURN;
35cd451c
GS
999 }
1000 else {
159b6efe 1001 gv = MUTABLE_GV(sv);
a0d0e21e 1002 }
ad64d0ec 1003 sv = is_pp_rv2av ? MUTABLE_SV(GvAVn(gv)) : MUTABLE_SV(GvHVn(gv));
533c011a 1004 if (PL_op->op_private & OPpLVAL_INTRO)
ad64d0ec 1005 sv = is_pp_rv2av ? MUTABLE_SV(save_ary(gv)) : MUTABLE_SV(save_hash(gv));
9f527363
FC
1006 }
1007 if (PL_op->op_flags & OPf_REF) {
17ab7946 1008 SETs(sv);
a0d0e21e 1009 RETURN;
9f527363 1010 }
5d9574c1 1011 else if (UNLIKELY(PL_op->op_private & OPpMAYBE_LVSUB)) {
40c94d11
FC
1012 const I32 flags = is_lvalue_sub();
1013 if (flags && !(flags & OPpENTERSUB_INARGS)) {
cde874ca 1014 if (gimme != G_ARRAY)
042560a6 1015 goto croak_cant_return;
17ab7946 1016 SETs(sv);
78f9721b 1017 RETURN;
40c94d11 1018 }
a0d0e21e
LW
1019 }
1020
17ab7946 1021 if (is_pp_rv2av) {
502c6561 1022 AV *const av = MUTABLE_AV(sv);
636fe681 1023 /* The guts of pp_rv2av */
96913b52 1024 if (gimme == G_ARRAY) {
d5524600
DM
1025 SP--;
1026 PUTBACK;
1027 S_pushav(aTHX_ av);
1028 SPAGAIN;
1c846c1f 1029 }
96913b52
VP
1030 else if (gimme == G_SCALAR) {
1031 dTARGET;
c70927a6 1032 const SSize_t maxarg = AvFILL(av) + 1;
96913b52 1033 SETi(maxarg);
93965878 1034 }
17ab7946
NC
1035 } else {
1036 /* The guts of pp_rv2hv */
96913b52
VP
1037 if (gimme == G_ARRAY) { /* array wanted */
1038 *PL_stack_sp = sv;
981b7185 1039 return Perl_do_kv(aTHX);
96913b52 1040 }
c8fe3bdf 1041 else if ((PL_op->op_private & OPpTRUEBOOL
adc42c31 1042 || ( PL_op->op_private & OPpMAYBE_TRUEBOOL
c8fe3bdf
FC
1043 && block_gimme() == G_VOID ))
1044 && (!SvRMAGICAL(sv) || !mg_find(sv, PERL_MAGIC_tied)))
1186f821 1045 SETs(HvUSEDKEYS(MUTABLE_HV(sv)) ? &PL_sv_yes : &PL_sv_no);
96913b52 1046 else if (gimme == G_SCALAR) {
1a8bdda9 1047 dTARG;
96913b52 1048 TARG = Perl_hv_scalar(aTHX_ MUTABLE_HV(sv));
96913b52
VP
1049 SETTARG;
1050 }
17ab7946 1051 }
be85d344 1052 RETURN;
042560a6
NC
1053
1054 croak_cant_return:
1055 Perl_croak(aTHX_ "Can't return %s to lvalue scalar context",
1056 is_pp_rv2av ? "array" : "hash");
77e217c6 1057 RETURN;
a0d0e21e
LW
1058}
1059
10c8fecd 1060STATIC void
fb8f4cf8 1061S_do_oddball(pTHX_ SV **oddkey, SV **firstkey)
10c8fecd 1062{
7918f24d
NC
1063 PERL_ARGS_ASSERT_DO_ODDBALL;
1064
fb8f4cf8 1065 if (*oddkey) {
6d822dc4 1066 if (ckWARN(WARN_MISC)) {
a3b680e6 1067 const char *err;
fb8f4cf8
RZ
1068 if (oddkey == firstkey &&
1069 SvROK(*oddkey) &&
1070 (SvTYPE(SvRV(*oddkey)) == SVt_PVAV ||
1071 SvTYPE(SvRV(*oddkey)) == SVt_PVHV))
10c8fecd 1072 {
a3b680e6 1073 err = "Reference found where even-sized list expected";
10c8fecd
GS
1074 }
1075 else
a3b680e6 1076 err = "Odd number of elements in hash assignment";
f1f66076 1077 Perl_warner(aTHX_ packWARN(WARN_MISC), "%s", err);
10c8fecd 1078 }
6d822dc4 1079
10c8fecd
GS
1080 }
1081}
1082
a5f48505
DM
1083
1084/* Do a mark and sweep with the SVf_BREAK flag to detect elements which
1085 * are common to both the LHS and RHS of an aassign, and replace them
1086 * with copies. All these copies are made before the actual list assign is
1087 * done.
1088 *
1089 * For example in ($a,$b) = ($b,$a), assigning the value of the first RHS
1090 * element ($b) to the first LH element ($a), modifies $a; when the
1091 * second assignment is done, the second RH element now has the wrong
1092 * value. So we initially replace the RHS with ($b, mortalcopy($a)).
1093 * Note that we don't need to make a mortal copy of $b.
1094 *
1095 * The algorithm below works by, for every RHS element, mark the
1096 * corresponding LHS target element with SVf_BREAK. Then if the RHS
1097 * element is found with SVf_BREAK set, it means it would have been
1098 * modified, so make a copy.
1099 * Note that by scanning both LHS and RHS in lockstep, we avoid
1100 * unnecessary copies (like $b above) compared with a naive
1101 * "mark all LHS; copy all marked RHS; unmark all LHS".
1102 *
1103 * If the LHS element is a 'my' declaration' and has a refcount of 1, then
1104 * it can't be common and can be skipped.
ebc643ce
DM
1105 *
1106 * On DEBUGGING builds it takes an extra boolean, fake. If true, it means
1107 * that we thought we didn't need to call S_aassign_copy_common(), but we
1108 * have anyway for sanity checking. If we find we need to copy, then panic.
a5f48505
DM
1109 */
1110
1111PERL_STATIC_INLINE void
1112S_aassign_copy_common(pTHX_ SV **firstlelem, SV **lastlelem,
ebc643ce
DM
1113 SV **firstrelem, SV **lastrelem
1114#ifdef DEBUGGING
1115 , bool fake
1116#endif
1117)
a5f48505
DM
1118{
1119 dVAR;
1120 SV **relem;
1121 SV **lelem;
1122 SSize_t lcount = lastlelem - firstlelem + 1;
1123 bool marked = FALSE; /* have we marked any LHS with SVf_BREAK ? */
1124 bool const do_rc1 = cBOOL(PL_op->op_private & OPpASSIGN_COMMON_RC1);
beb08a1e 1125 bool copy_all = FALSE;
a5f48505
DM
1126
1127 assert(!PL_in_clean_all); /* SVf_BREAK not already in use */
1128 assert(firstlelem < lastlelem); /* at least 2 LH elements */
1129 assert(firstrelem < lastrelem); /* at least 2 RH elements */
1130
ebc643ce
DM
1131
1132 lelem = firstlelem;
a5f48505
DM
1133 /* we never have to copy the first RH element; it can't be corrupted
1134 * by assigning something to the corresponding first LH element.
1135 * So this scan does in a loop: mark LHS[N]; test RHS[N+1]
1136 */
ebc643ce 1137 relem = firstrelem + 1;
a5f48505
DM
1138
1139 for (; relem <= lastrelem; relem++) {
1140 SV *svr;
1141
1142 /* mark next LH element */
1143
1144 if (--lcount >= 0) {
1145 SV *svl = *lelem++;
1146
1147 if (UNLIKELY(!svl)) {/* skip AV alias marker */
1148 assert (lelem <= lastlelem);
1149 svl = *lelem++;
1150 lcount--;
1151 }
1152
1153 assert(svl);
beb08a1e
TC
1154 if (SvSMAGICAL(svl)) {
1155 copy_all = TRUE;
1156 }
a5f48505
DM
1157 if (SvTYPE(svl) == SVt_PVAV || SvTYPE(svl) == SVt_PVHV) {
1158 if (!marked)
1159 return;
1160 /* this LH element will consume all further args;
1161 * no need to mark any further LH elements (if any).
1162 * But we still need to scan any remaining RHS elements;
1163 * set lcount negative to distinguish from lcount == 0,
1164 * so the loop condition continues being true
1165 */
1166 lcount = -1;
1167 lelem--; /* no need to unmark this element */
1168 }
94a5f659 1169 else if (!(do_rc1 && SvREFCNT(svl) == 1) && !SvIMMORTAL(svl)) {
a5f48505
DM
1170 SvFLAGS(svl) |= SVf_BREAK;
1171 marked = TRUE;
1172 }
1173 else if (!marked) {
1174 /* don't check RH element if no SVf_BREAK flags set yet */
1175 if (!lcount)
1176 break;
1177 continue;
1178 }
1179 }
1180
1181 /* see if corresponding RH element needs copying */
1182
1183 assert(marked);
1184 svr = *relem;
1185 assert(svr);
1186
5c1db569 1187 if (UNLIKELY(SvFLAGS(svr) & (SVf_BREAK|SVs_GMG) || copy_all)) {
1050723f 1188 U32 brk = (SvFLAGS(svr) & SVf_BREAK);
a5f48505 1189
ebc643ce
DM
1190#ifdef DEBUGGING
1191 if (fake) {
9ae0115f 1192 /* op_dump(PL_op); */
ebc643ce
DM
1193 Perl_croak(aTHX_
1194 "panic: aassign skipped needed copy of common RH elem %"
1195 UVuf, (UV)(relem - firstrelem));
1196 }
1197#endif
1198
a5f48505
DM
1199 TAINT_NOT; /* Each item is independent */
1200
1201 /* Dear TODO test in t/op/sort.t, I love you.
1202 (It's relying on a panic, not a "semi-panic" from newSVsv()
1203 and then an assertion failure below.) */
1204 if (UNLIKELY(SvIS_FREED(svr))) {
1205 Perl_croak(aTHX_ "panic: attempt to copy freed scalar %p",
1206 (void*)svr);
1207 }
1208 /* avoid break flag while copying; otherwise COW etc
1209 * disabled... */
1210 SvFLAGS(svr) &= ~SVf_BREAK;
1211 /* Not newSVsv(), as it does not allow copy-on-write,
8c1e192f
DM
1212 resulting in wasteful copies.
1213 Also, we use SV_NOSTEAL in case the SV is used more than
1214 once, e.g. (...) = (f())[0,0]
1215 Where the same SV appears twice on the RHS without a ref
1216 count bump. (Although I suspect that the SV won't be
1217 stealable here anyway - DAPM).
1218 */
a5f48505
DM
1219 *relem = sv_mortalcopy_flags(svr,
1220 SV_GMAGIC|SV_DO_COW_SVSETSV|SV_NOSTEAL);
1221 /* ... but restore afterwards in case it's needed again,
1222 * e.g. ($a,$b,$c) = (1,$a,$a)
1223 */
1050723f 1224 SvFLAGS(svr) |= brk;
a5f48505
DM
1225 }
1226
1227 if (!lcount)
1228 break;
1229 }
1230
1231 if (!marked)
1232 return;
1233
1234 /*unmark LHS */
1235
1236 while (lelem > firstlelem) {
1237 SV * const svl = *(--lelem);
1238 if (svl)
1239 SvFLAGS(svl) &= ~SVf_BREAK;
1240 }
1241}
1242
1243
1244
a0d0e21e
LW
1245PP(pp_aassign)
1246{
27da23d5 1247 dVAR; dSP;
3280af22
NIS
1248 SV **lastlelem = PL_stack_sp;
1249 SV **lastrelem = PL_stack_base + POPMARK;
1250 SV **firstrelem = PL_stack_base + POPMARK + 1;
a0d0e21e
LW
1251 SV **firstlelem = lastrelem + 1;
1252
eb578fdb
KW
1253 SV **relem;
1254 SV **lelem;
1c23e2bd 1255 U8 gimme;
a68090fe
DM
1256 /* PL_delaymagic is restored by JUMPENV_POP on dieing, so we
1257 * only need to save locally, not on the save stack */
1258 U16 old_delaymagic = PL_delaymagic;
ebc643ce
DM
1259#ifdef DEBUGGING
1260 bool fake = 0;
1261#endif
5637b936 1262
3280af22 1263 PL_delaymagic = DM_DELAY; /* catch simultaneous items */
a0d0e21e
LW
1264
1265 /* If there's a common identifier on both sides we have to take
1266 * special care that assigning the identifier on the left doesn't
1267 * clobber a value on the right that's used later in the list.
1268 */
acdea6f0 1269
beb08a1e
TC
1270 /* at least 2 LH and RH elements, or commonality isn't an issue */
1271 if (firstlelem < lastlelem && firstrelem < lastrelem) {
5c1db569
TC
1272 for (relem = firstrelem+1; relem <= lastrelem; relem++) {
1273 if (SvGMAGICAL(*relem))
1274 goto do_scan;
1275 }
beb08a1e
TC
1276 for (lelem = firstlelem; lelem <= lastlelem; lelem++) {
1277 if (*lelem && SvSMAGICAL(*lelem))
1278 goto do_scan;
a5f48505 1279 }
beb08a1e
TC
1280 if ( PL_op->op_private & (OPpASSIGN_COMMON_SCALAR|OPpASSIGN_COMMON_RC1) ) {
1281 if (PL_op->op_private & OPpASSIGN_COMMON_RC1) {
1282 /* skip the scan if all scalars have a ref count of 1 */
1283 for (lelem = firstlelem; lelem <= lastlelem; lelem++) {
8b0c3377 1284 SV *sv = *lelem;
beb08a1e
TC
1285 if (!sv || SvREFCNT(sv) == 1)
1286 continue;
1287 if (SvTYPE(sv) != SVt_PVAV && SvTYPE(sv) != SVt_PVAV)
1288 goto do_scan;
1289 break;
1290 }
1291 }
1292 else {
1293 do_scan:
1294 S_aassign_copy_common(aTHX_
1295 firstlelem, lastlelem, firstrelem, lastrelem
ebc643ce 1296#ifdef DEBUGGING
beb08a1e 1297 , fake
ebc643ce 1298#endif
beb08a1e
TC
1299 );
1300 }
a5f48505 1301 }
a0d0e21e 1302 }
ebc643ce
DM
1303#ifdef DEBUGGING
1304 else {
1305 /* on debugging builds, do the scan even if we've concluded we
1306 * don't need to, then panic if we find commonality. Note that the
1307 * scanner assumes at least 2 elements */
1308 if (firstlelem < lastlelem && firstrelem < lastrelem) {
1309 fake = 1;
1310 goto do_scan;
1311 }
1312 }
1313#endif
a0d0e21e 1314
a5f48505 1315 gimme = GIMME_V;
a0d0e21e
LW
1316 relem = firstrelem;
1317 lelem = firstlelem;
10c8fecd 1318
8b0c3377
DM
1319 if (relem > lastrelem)
1320 goto no_relems;
1321
1322 /* first lelem loop while there are still relems */
5d9574c1 1323 while (LIKELY(lelem <= lastlelem)) {
bdaf10a5 1324 bool alias = FALSE;
8b0c3377
DM
1325 SV *lsv = *lelem++;
1326
c73f612f
DM
1327 TAINT_NOT; /* Each item stands on its own, taintwise. */
1328
8b0c3377
DM
1329 assert(relem <= lastrelem);
1330 if (UNLIKELY(!lsv)) {
bdaf10a5 1331 alias = TRUE;
8b0c3377
DM
1332 lsv = *lelem++;
1333 ASSUME(SvTYPE(lsv) == SVt_PVAV);
bdaf10a5 1334 }
a5f48505 1335
8b0c3377
DM
1336 switch (SvTYPE(lsv)) {
1337 case SVt_PVAV: {
1338 SV **svp;
1339 SSize_t i;
1340 SSize_t tmps_base;
1341 SSize_t nelems = lastrelem - relem + 1;
b09ed995 1342 AV *ary = MUTABLE_AV(lsv);
8b0c3377
DM
1343
1344 /* Assigning to an aggregate is tricky. First there is the
1345 * issue of commonality, e.g. @a = ($a[0]). Since the
1346 * stack isn't refcounted, clearing @a prior to storing
1347 * elements will free $a[0]. Similarly with
1348 * sub FETCH { $status[$_[1]] } @status = @tied[0,1];
1349 *
1350 * The way to avoid these issues is to make the copy of each
1351 * SV (and we normally store a *copy* in the array) *before*
1352 * clearing the array. But this has a problem in that
1353 * if the code croaks during copying, the not-yet-stored copies
1354 * could leak. One way to avoid this is to make all the copies
1355 * mortal, but that's quite expensive.
1356 *
1357 * The current solution to these issues is to use a chunk
1358 * of the tmps stack as a temporary refcounted-stack. SVs
1359 * will be put on there during processing to avoid leaks,
1360 * but will be removed again before the end of this block,
1361 * so free_tmps() is never normally called. Also, the
1362 * sv_refcnt of the SVs doesn't have to be manipulated, since
1363 * the ownership of 1 reference count is transferred directly
1364 * from the tmps stack to the AV when the SV is stored.
1365 *
1366 * We disarm slots in the temps stack by storing PL_sv_undef
1367 * there: it doesn't matter if that SV's refcount is
1368 * repeatedly decremented during a croak. But usually this is
1369 * only an interim measure. By the end of this code block
1370 * we try where possible to not leave any PL_sv_undef's on the
1371 * tmps stack e.g. by shuffling newer entries down.
1372 *
1373 * There is one case where we don't copy: non-magical
1374 * SvTEMP(sv)'s with a ref count of 1. The only owner of these
1375 * is on the tmps stack, so its safe to directly steal the SV
1376 * rather than copying. This is common in things like function
1377 * returns, map etc, which all return a list of such SVs.
1378 *
1379 * Note however something like @a = (f())[0,0], where there is
1380 * a danger of the same SV being shared: this avoided because
1381 * when the SV is stored as $a[0], its ref count gets bumped,
1382 * so the RC==1 test fails and the second element is copied
1383 * instead.
1384 *
1385 * We also use one slot in the tmps stack to hold an extra
1386 * ref to the array, to ensure it doesn't get prematurely
1387 * freed. Again, this is removed before the end of this block.
1388 *
1389 * Note that OPpASSIGN_COMMON_AGG is used to flag a possible
1390 * @a = ($a[0]) case, but the current implementation uses the
1391 * same algorithm regardless, so ignores that flag. (It *is*
1392 * used in the hash branch below, however).
1393 */
1394
1395 /* Reserve slots for ary, plus the elems we're about to copy,
1396 * then protect ary and temporarily void the remaining slots
1397 * with &PL_sv_undef */
1398 EXTEND_MORTAL(nelems + 1);
1399 PL_tmps_stack[++PL_tmps_ix] = SvREFCNT_inc_simple_NN(ary);
1400 tmps_base = PL_tmps_ix + 1;
1401 for (i = 0; i < nelems; i++)
1402 PL_tmps_stack[tmps_base + i] = &PL_sv_undef;
1403 PL_tmps_ix += nelems;
1404
1405 /* Make a copy of each RHS elem and save on the tmps_stack
1406 * (or pass through where we can optimise away the copy) */
1407
1408 if (UNLIKELY(alias)) {
1409 U32 lval = (gimme == G_ARRAY)
1410 ? (PL_op->op_flags & OPf_MOD || LVRET) : 0;
a5f48505 1411 for (svp = relem; svp <= lastrelem; svp++) {
8b0c3377
DM
1412 SV *rsv = *svp;
1413
1414 SvGETMAGIC(rsv);
1415 if (!SvROK(rsv))
1416 DIE(aTHX_ "Assigned value is not a reference");
1417 if (SvTYPE(SvRV(rsv)) > SVt_PVLV)
1418 /* diag_listed_as: Assigned value is not %s reference */
1419 DIE(aTHX_
1420 "Assigned value is not a SCALAR reference");
1421 if (lval)
1422 *svp = rsv = sv_mortalcopy(rsv);
1423 /* XXX else check for weak refs? */
1424 rsv = SvREFCNT_inc_NN(SvRV(rsv));
1425 assert(tmps_base <= PL_tmps_max);
1426 PL_tmps_stack[tmps_base++] = rsv;
a5f48505 1427 }
a5f48505 1428 }
8b0c3377
DM
1429 else {
1430 for (svp = relem; svp <= lastrelem; svp++) {
1431 SV *rsv = *svp;
a5f48505 1432
8b0c3377
DM
1433 if (SvTEMP(rsv) && !SvGMAGICAL(rsv) && SvREFCNT(rsv) == 1) {
1434 /* can skip the copy */
1435 SvREFCNT_inc_simple_void_NN(rsv);
1436 SvTEMP_off(rsv);
1437 }
a5f48505 1438 else {
8b0c3377
DM
1439 SV *nsv;
1440 /* do get before newSV, in case it dies and leaks */
1441 SvGETMAGIC(rsv);
1442 nsv = newSV(0);
8c1e192f
DM
1443 /* see comment in S_aassign_copy_common about
1444 * SV_NOSTEAL */
8b0c3377
DM
1445 sv_setsv_flags(nsv, rsv,
1446 (SV_DO_COW_SVSETSV|SV_NOSTEAL));
1447 rsv = *svp = nsv;
a5f48505 1448 }
8b0c3377
DM
1449
1450 assert(tmps_base <= PL_tmps_max);
1451 PL_tmps_stack[tmps_base++] = rsv;
1452 }
1453 }
1454
1455 if (SvRMAGICAL(ary) || AvFILLp(ary) >= 0) /* may be non-empty */
1456 av_clear(ary);
1457
1458 /* store in the array, the SVs that are in the tmps stack */
1459
1460 tmps_base -= nelems;
1461
80c1439f 1462 if (SvMAGICAL(ary) || SvREADONLY(ary) || !AvREAL(ary)) {
8b0c3377
DM
1463 /* for arrays we can't cheat with, use the official API */
1464 av_extend(ary, nelems - 1);
1465 for (i = 0; i < nelems; i++) {
1466 SV **svp = &(PL_tmps_stack[tmps_base + i]);
1467 SV *rsv = *svp;
1468 /* A tied store won't take ownership of rsv, so keep
1469 * the 1 refcnt on the tmps stack; otherwise disarm
1470 * the tmps stack entry */
1471 if (av_store(ary, i, rsv))
1472 *svp = &PL_sv_undef;
1473 /* av_store() may have added set magic to rsv */;
1474 SvSETMAGIC(rsv);
1475 }
1476 /* disarm ary refcount: see comments below about leak */
1477 PL_tmps_stack[tmps_base - 1] = &PL_sv_undef;
1478 }
1479 else {
1480 /* directly access/set the guts of the AV */
1481 SSize_t fill = nelems - 1;
1482 if (fill > AvMAX(ary))
1483 av_extend_guts(ary, fill, &AvMAX(ary), &AvALLOC(ary),
1484 &AvARRAY(ary));
1485 AvFILLp(ary) = fill;
1486 Copy(&(PL_tmps_stack[tmps_base]), AvARRAY(ary), nelems, SV*);
1487 /* Quietly remove all the SVs from the tmps stack slots,
1488 * since ary has now taken ownership of the refcnt.
1489 * Also remove ary: which will now leak if we die before
1490 * the SvREFCNT_dec_NN(ary) below */
1491 if (UNLIKELY(PL_tmps_ix >= tmps_base + nelems))
1492 Move(&PL_tmps_stack[tmps_base + nelems],
1493 &PL_tmps_stack[tmps_base - 1],
1494 PL_tmps_ix - (tmps_base + nelems) + 1,
1495 SV*);
1496 PL_tmps_ix -= (nelems + 1);
1497 }
1498
5d9574c1 1499 if (UNLIKELY(PL_delaymagic & DM_ARRAY_ISA))
8b0c3377 1500 /* its assumed @ISA set magic can't die and leak ary */
ad64d0ec 1501 SvSETMAGIC(MUTABLE_SV(ary));
8b0c3377
DM
1502 SvREFCNT_dec_NN(ary);
1503
1504 relem = lastrelem + 1;
1505 goto no_relems;
a5f48505
DM
1506 }
1507
10c8fecd 1508 case SVt_PVHV: { /* normal hash */
8b0c3377
DM
1509
1510 SV **svp;
1511 bool dirty_tmps;
1512 SSize_t i;
1513 SSize_t tmps_base;
1514 SSize_t nelems = lastrelem - relem + 1;
b09ed995 1515 HV *hash = MUTABLE_HV(lsv);
8b0c3377
DM
1516
1517 if (UNLIKELY(nelems & 1)) {
1518 do_oddball(lastrelem, relem);
1519 /* we have firstlelem to reuse, it's not needed any more */
1520 *++lastrelem = &PL_sv_undef;
1521 nelems++;
1522 }
1523
1524 /* See the SVt_PVAV branch above for a long description of
1525 * how the following all works. The main difference for hashes
1526 * is that we treat keys and values separately (and have
1527 * separate loops for them): as for arrays, values are always
1528 * copied (except for the SvTEMP optimisation), since they
1529 * need to be stored in the hash; while keys are only
1530 * processed where they might get prematurely freed or
1531 * whatever. */
1532
1533 /* tmps stack slots:
1534 * * reserve a slot for the hash keepalive;
1535 * * reserve slots for the hash values we're about to copy;
1536 * * preallocate for the keys we'll possibly copy or refcount bump
1537 * later;
1538 * then protect hash and temporarily void the remaining
1539 * value slots with &PL_sv_undef */
1540 EXTEND_MORTAL(nelems + 1);
1541
1542 /* convert to number of key/value pairs */
1543 nelems >>= 1;
1544
1545 PL_tmps_stack[++PL_tmps_ix] = SvREFCNT_inc_simple_NN(hash);
1546 tmps_base = PL_tmps_ix + 1;
1547 for (i = 0; i < nelems; i++)
1548 PL_tmps_stack[tmps_base + i] = &PL_sv_undef;
1549 PL_tmps_ix += nelems;
1550
1551 /* Make a copy of each RHS hash value and save on the tmps_stack
1552 * (or pass through where we can optimise away the copy) */
1553
1554 for (svp = relem + 1; svp <= lastrelem; svp += 2) {
1555 SV *rsv = *svp;
1556
1557 if (SvTEMP(rsv) && !SvGMAGICAL(rsv) && SvREFCNT(rsv) == 1) {
1558 /* can skip the copy */
1559 SvREFCNT_inc_simple_void_NN(rsv);
1560 SvTEMP_off(rsv);
1561 }
1562 else {
1563 SV *nsv;
1564 /* do get before newSV, in case it dies and leaks */
1565 SvGETMAGIC(rsv);
1566 nsv = newSV(0);
1567 /* see comment in S_aassign_copy_common about
1568 * SV_NOSTEAL */
1569 sv_setsv_flags(nsv, rsv,
1570 (SV_DO_COW_SVSETSV|SV_NOSTEAL));
1571 rsv = *svp = nsv;
1c4ea384
RZ
1572 }
1573
8b0c3377
DM
1574 assert(tmps_base <= PL_tmps_max);
1575 PL_tmps_stack[tmps_base++] = rsv;
1576 }
1577 tmps_base -= nelems;
a5f48505 1578
a5f48505 1579
8b0c3377
DM
1580 /* possibly protect keys */
1581
1582 if (UNLIKELY(gimme == G_ARRAY)) {
1583 /* handle e.g.
1584 * @a = ((%h = ($$r, 1)), $r = "x");
1585 * $_++ for %h = (1,2,3,4);
1586 */
1587 EXTEND_MORTAL(nelems);
1588 for (svp = relem; svp <= lastrelem; svp += 2)
1589 *svp = sv_mortalcopy_flags(*svp,
1590 SV_GMAGIC|SV_DO_COW_SVSETSV|SV_NOSTEAL);
1591 }
1592 else if (PL_op->op_private & OPpASSIGN_COMMON_AGG) {
1593 /* for possible commonality, e.g.
1594 * %h = ($h{a},1)
1595 * avoid premature freeing RHS keys by mortalising
1596 * them.
1597 * For a magic element, make a copy so that its magic is
1598 * called *before* the hash is emptied (which may affect
1599 * a tied value for example).
1600 * In theory we should check for magic keys in all
1601 * cases, not just under OPpASSIGN_COMMON_AGG, but in
1602 * practice, !OPpASSIGN_COMMON_AGG implies only
1603 * constants or padtmps on the RHS.
1604 */
1605 EXTEND_MORTAL(nelems);
1606 for (svp = relem; svp <= lastrelem; svp += 2) {
1607 SV *rsv = *svp;
1608 if (UNLIKELY(SvGMAGICAL(rsv))) {
1609 SSize_t n;
a5f48505
DM
1610 *svp = sv_mortalcopy_flags(*svp,
1611 SV_GMAGIC|SV_DO_COW_SVSETSV|SV_NOSTEAL);
8b0c3377
DM
1612 /* allow other branch to continue pushing
1613 * onto tmps stack without checking each time */
1614 n = (lastrelem - relem) >> 1;
1615 EXTEND_MORTAL(n);
a5f48505 1616 }
8b0c3377
DM
1617 else
1618 PL_tmps_stack[++PL_tmps_ix] =
1619 SvREFCNT_inc_simple_NN(rsv);
a5f48505 1620 }
8b0c3377 1621 }
a5f48505 1622
8b0c3377
DM
1623 if (SvRMAGICAL(hash) || HvUSEDKEYS(hash))
1624 hv_clear(hash);
a5f48505 1625
8b0c3377
DM
1626 /* now assign the keys and values to the hash */
1627
1628 dirty_tmps = FALSE;
1629
1630 if (UNLIKELY(gimme == G_ARRAY)) {
1631 /* @a = (%h = (...)) etc */
1632 SV **svp;
1633 SV **topelem = relem;
1634
1635 for (i = 0, svp = relem; svp <= lastrelem; i++, svp++) {
1636 SV *key = *svp++;
1637 SV *val = *svp;
1638 /* remove duplicates from list we return */
1639 if (!hv_exists_ent(hash, key, 0)) {
1640 /* copy key back: possibly to an earlier
1641 * stack location if we encountered dups earlier,
1642 * The values will be updated later
1643 */
1644 *topelem = key;
1645 topelem += 2;
632b9d6f 1646 }
8b0c3377
DM
1647 /* A tied store won't take ownership of val, so keep
1648 * the 1 refcnt on the tmps stack; otherwise disarm
1649 * the tmps stack entry */
1650 if (hv_store_ent(hash, key, val, 0))
1651 PL_tmps_stack[tmps_base + i] = &PL_sv_undef;
1652 else
1653 dirty_tmps = TRUE;
1654 /* hv_store_ent() may have added set magic to val */;
1655 SvSETMAGIC(val);
1656 }
1657 if (topelem < svp) {
1c4ea384
RZ
1658 /* at this point we have removed the duplicate key/value
1659 * pairs from the stack, but the remaining values may be
1660 * wrong; i.e. with (a 1 a 2 b 3) on the stack we've removed
1661 * the (a 2), but the stack now probably contains
1662 * (a <freed> b 3), because { hv_save(a,1); hv_save(a,2) }
1663 * obliterates the earlier key. So refresh all values. */
8b0c3377
DM
1664 lastrelem = topelem - 1;
1665 while (relem < lastrelem) {
1c4ea384
RZ
1666 HE *he;
1667 he = hv_fetch_ent(hash, *relem++, 0, 0);
1668 *relem++ = (he ? HeVAL(he) : &PL_sv_undef);
1669 }
1670 }
8b0c3377
DM
1671 }
1672 else {
1673 SV **svp;
1674 for (i = 0, svp = relem; svp <= lastrelem; i++, svp++) {
1675 SV *key = *svp++;
1676 SV *val = *svp;
1677 if (hv_store_ent(hash, key, val, 0))
1678 PL_tmps_stack[tmps_base + i] = &PL_sv_undef;
1679 else
1680 dirty_tmps = TRUE;
1681 /* hv_store_ent() may have added set magic to val */;
1682 SvSETMAGIC(val);
1683 }
1684 }
1685
1686 if (dirty_tmps) {
1687 /* there are still some 'live' recounts on the tmps stack
1688 * - usually caused by storing into a tied hash. So let
1689 * free_tmps() do the proper but slow job later.
1690 * Just disarm hash refcount: see comments below about leak
1691 */
1692 PL_tmps_stack[tmps_base - 1] = &PL_sv_undef;
1693 }
1694 else {
1695 /* Quietly remove all the SVs from the tmps stack slots,
1696 * since hash has now taken ownership of the refcnt.
1697 * Also remove hash: which will now leak if we die before
1698 * the SvREFCNT_dec_NN(hash) below */
1699 if (UNLIKELY(PL_tmps_ix >= tmps_base + nelems))
1700 Move(&PL_tmps_stack[tmps_base + nelems],
1701 &PL_tmps_stack[tmps_base - 1],
1702 PL_tmps_ix - (tmps_base + nelems) + 1,
1703 SV*);
1704 PL_tmps_ix -= (nelems + 1);
1705 }
1706
1707 SvREFCNT_dec_NN(hash);
1708
1709 relem = lastrelem + 1;
1710 goto no_relems;
1711 }
1712
a0d0e21e 1713 default:
8b0c3377 1714 if (!SvIMMORTAL(lsv)) {
d24e3eb1
DM
1715 SV *ref;
1716
8b0c3377
DM
1717 if (UNLIKELY(
1718 SvTEMP(lsv) && !SvSMAGICAL(lsv) && SvREFCNT(lsv) == 1 &&
1719 (!isGV_with_GP(lsv) || SvFAKE(lsv)) && ckWARN(WARN_MISC)
1720 ))
1721 Perl_warner(aTHX_
1722 packWARN(WARN_MISC),
1723 "Useless assignment to a temporary"
1724 );
d24e3eb1
DM
1725
1726 /* avoid freeing $$lsv if it might be needed for further
1727 * elements, e.g. ($ref, $foo) = (1, $$ref) */
1728 if ( SvROK(lsv)
1729 && ( ((ref = SvRV(lsv)), SvREFCNT(ref)) == 1)
1730 && lelem <= lastlelem
1731 ) {
1732 SSize_t ix;
1733 SvREFCNT_inc_simple_void_NN(ref);
1734 /* an unrolled sv_2mortal */
1735 ix = ++PL_tmps_ix;
1736 if (UNLIKELY(ix >= PL_tmps_max))
1737 /* speculatively grow enough to cover other
1738 * possible refs */
1739 ix = tmps_grow_p(ix + (lastlelem - lelem));
1740 PL_tmps_stack[ix] = ref;
1741 }
1742
8b0c3377
DM
1743 sv_setsv(lsv, *relem);
1744 *relem = lsv;
1745 SvSETMAGIC(lsv);
1746 }
1747 if (++relem > lastrelem)
1748 goto no_relems;
a0d0e21e 1749 break;
8b0c3377
DM
1750 } /* switch */
1751 } /* while */
1752
1753
1754 no_relems:
1755
1756 /* simplified lelem loop for when there are no relems left */
1757 while (LIKELY(lelem <= lastlelem)) {
1758 SV *lsv = *lelem++;
c73f612f
DM
1759
1760 TAINT_NOT; /* Each item stands on its own, taintwise. */
1761
8b0c3377
DM
1762 if (UNLIKELY(!lsv)) {
1763 lsv = *lelem++;
1764 ASSUME(SvTYPE(lsv) == SVt_PVAV);
a0d0e21e 1765 }
8b0c3377
DM
1766
1767 switch (SvTYPE(lsv)) {
1768 case SVt_PVAV:
b09ed995
DM
1769 if (SvRMAGICAL(lsv) || AvFILLp((SV*)lsv) >= 0) {
1770 av_clear((AV*)lsv);
8b0c3377 1771 if (UNLIKELY(PL_delaymagic & DM_ARRAY_ISA))
b09ed995 1772 SvSETMAGIC(lsv);
8b0c3377
DM
1773 }
1774 break;
1775
1776 case SVt_PVHV:
b09ed995
DM
1777 if (SvRMAGICAL(lsv) || HvUSEDKEYS((HV*)lsv))
1778 hv_clear((HV*)lsv);
8b0c3377
DM
1779 break;
1780
1781 default:
1782 if (!SvIMMORTAL(lsv)) {
e03e82a0 1783 sv_set_undef(lsv);
8b0c3377 1784 SvSETMAGIC(lsv);
b09ed995 1785 *relem++ = lsv;
8b0c3377
DM
1786 }
1787 break;
1788 } /* switch */
1789 } /* while */
1790
c73f612f
DM
1791 TAINT_NOT; /* result of list assign isn't tainted */
1792
5d9574c1 1793 if (UNLIKELY(PL_delaymagic & ~DM_DELAY)) {
985213f2 1794 /* Will be used to set PL_tainting below */
dfff4baf
BF
1795 Uid_t tmp_uid = PerlProc_getuid();
1796 Uid_t tmp_euid = PerlProc_geteuid();
1797 Gid_t tmp_gid = PerlProc_getgid();
1798 Gid_t tmp_egid = PerlProc_getegid();
985213f2 1799
b469f1e0 1800 /* XXX $> et al currently silently ignore failures */
3280af22 1801 if (PL_delaymagic & DM_UID) {
a0d0e21e 1802#ifdef HAS_SETRESUID
b469f1e0
JH
1803 PERL_UNUSED_RESULT(
1804 setresuid((PL_delaymagic & DM_RUID) ? PL_delaymagic_uid : (Uid_t)-1,
1805 (PL_delaymagic & DM_EUID) ? PL_delaymagic_euid : (Uid_t)-1,
1806 (Uid_t)-1));
56febc5e
AD
1807#else
1808# ifdef HAS_SETREUID
b469f1e0
JH
1809 PERL_UNUSED_RESULT(
1810 setreuid((PL_delaymagic & DM_RUID) ? PL_delaymagic_uid : (Uid_t)-1,
1811 (PL_delaymagic & DM_EUID) ? PL_delaymagic_euid : (Uid_t)-1));
56febc5e
AD
1812# else
1813# ifdef HAS_SETRUID
b28d0864 1814 if ((PL_delaymagic & DM_UID) == DM_RUID) {
b469f1e0 1815 PERL_UNUSED_RESULT(setruid(PL_delaymagic_uid));
b28d0864 1816 PL_delaymagic &= ~DM_RUID;
a0d0e21e 1817 }
56febc5e
AD
1818# endif /* HAS_SETRUID */
1819# ifdef HAS_SETEUID
b28d0864 1820 if ((PL_delaymagic & DM_UID) == DM_EUID) {
b469f1e0 1821 PERL_UNUSED_RESULT(seteuid(PL_delaymagic_euid));
b28d0864 1822 PL_delaymagic &= ~DM_EUID;
a0d0e21e 1823 }
56febc5e 1824# endif /* HAS_SETEUID */
b28d0864 1825 if (PL_delaymagic & DM_UID) {
985213f2 1826 if (PL_delaymagic_uid != PL_delaymagic_euid)
cea2e8a9 1827 DIE(aTHX_ "No setreuid available");
b469f1e0 1828 PERL_UNUSED_RESULT(PerlProc_setuid(PL_delaymagic_uid));
a0d0e21e 1829 }
56febc5e
AD
1830# endif /* HAS_SETREUID */
1831#endif /* HAS_SETRESUID */
04783dc7 1832
985213f2
AB
1833 tmp_uid = PerlProc_getuid();
1834 tmp_euid = PerlProc_geteuid();
a0d0e21e 1835 }
b469f1e0 1836 /* XXX $> et al currently silently ignore failures */
3280af22 1837 if (PL_delaymagic & DM_GID) {
a0d0e21e 1838#ifdef HAS_SETRESGID
b469f1e0
JH
1839 PERL_UNUSED_RESULT(
1840 setresgid((PL_delaymagic & DM_RGID) ? PL_delaymagic_gid : (Gid_t)-1,
1841 (PL_delaymagic & DM_EGID) ? PL_delaymagic_egid : (Gid_t)-1,
1842 (Gid_t)-1));
56febc5e
AD
1843#else
1844# ifdef HAS_SETREGID
b469f1e0
JH
1845 PERL_UNUSED_RESULT(
1846 setregid((PL_delaymagic & DM_RGID) ? PL_delaymagic_gid : (Gid_t)-1,
1847 (PL_delaymagic & DM_EGID) ? PL_delaymagic_egid : (Gid_t)-1));
56febc5e
AD
1848# else
1849# ifdef HAS_SETRGID
b28d0864 1850 if ((PL_delaymagic & DM_GID) == DM_RGID) {
b469f1e0 1851 PERL_UNUSED_RESULT(setrgid(PL_delaymagic_gid));
b28d0864 1852 PL_delaymagic &= ~DM_RGID;
a0d0e21e 1853 }
56febc5e
AD
1854# endif /* HAS_SETRGID */
1855# ifdef HAS_SETEGID
b28d0864 1856 if ((PL_delaymagic & DM_GID) == DM_EGID) {
b469f1e0 1857 PERL_UNUSED_RESULT(setegid(PL_delaymagic_egid));
b28d0864 1858 PL_delaymagic &= ~DM_EGID;
a0d0e21e 1859 }
56febc5e 1860# endif /* HAS_SETEGID */
b28d0864 1861 if (PL_delaymagic & DM_GID) {
985213f2 1862 if (PL_delaymagic_gid != PL_delaymagic_egid)
cea2e8a9 1863 DIE(aTHX_ "No setregid available");
b469f1e0 1864 PERL_UNUSED_RESULT(PerlProc_setgid(PL_delaymagic_gid));
a0d0e21e 1865 }
56febc5e
AD
1866# endif /* HAS_SETREGID */
1867#endif /* HAS_SETRESGID */
04783dc7 1868
985213f2
AB
1869 tmp_gid = PerlProc_getgid();
1870 tmp_egid = PerlProc_getegid();
a0d0e21e 1871 }
284167a5 1872 TAINTING_set( TAINTING_get | (tmp_uid && (tmp_euid != tmp_uid || tmp_egid != tmp_gid)) );
9a9b5ec9
DM
1873#ifdef NO_TAINT_SUPPORT
1874 PERL_UNUSED_VAR(tmp_uid);
1875 PERL_UNUSED_VAR(tmp_euid);
1876 PERL_UNUSED_VAR(tmp_gid);
1877 PERL_UNUSED_VAR(tmp_egid);
1878#endif
a0d0e21e 1879 }
a68090fe 1880 PL_delaymagic = old_delaymagic;
54310121 1881
54310121
PP
1882 if (gimme == G_VOID)
1883 SP = firstrelem - 1;
1884 else if (gimme == G_SCALAR) {
1885 dTARGET;
1886 SP = firstrelem;
b09ed995 1887 EXTEND(SP,1);
8b0c3377 1888 SETi(firstlelem - firstrelem);
54310121 1889 }
b09ed995
DM
1890 else
1891 SP = relem - 1;
08aeb9f7 1892
54310121 1893 RETURN;
a0d0e21e
LW
1894}
1895
8782bef2
GB
1896PP(pp_qr)
1897{
20b7effb 1898 dSP;
eb578fdb 1899 PMOP * const pm = cPMOP;
fe578d7f 1900 REGEXP * rx = PM_GETRE(pm);
10599a69 1901 SV * const pkg = rx ? CALLREG_PACKAGE(rx) : NULL;
c4420975 1902 SV * const rv = sv_newmortal();
d63c20f2
DM
1903 CV **cvp;
1904 CV *cv;
288b8c02
NC
1905
1906 SvUPGRADE(rv, SVt_IV);
c2123ae3
NC
1907 /* For a subroutine describing itself as "This is a hacky workaround" I'm
1908 loathe to use it here, but it seems to be the right fix. Or close.
1909 The key part appears to be that it's essential for pp_qr to return a new
1910 object (SV), which implies that there needs to be an effective way to
1911 generate a new SV from the existing SV that is pre-compiled in the
1912 optree. */
1913 SvRV_set(rv, MUTABLE_SV(reg_temp_copy(NULL, rx)));
288b8c02
NC
1914 SvROK_on(rv);
1915
8d919b0a 1916 cvp = &( ReANY((REGEXP *)SvRV(rv))->qr_anoncv);
5d9574c1 1917 if (UNLIKELY((cv = *cvp) && CvCLONE(*cvp))) {
d63c20f2 1918 *cvp = cv_clone(cv);
fc2b2dca 1919 SvREFCNT_dec_NN(cv);
d63c20f2
DM
1920 }
1921
288b8c02 1922 if (pkg) {
f815daf2 1923 HV *const stash = gv_stashsv(pkg, GV_ADD);
fc2b2dca 1924 SvREFCNT_dec_NN(pkg);
288b8c02
NC
1925 (void)sv_bless(rv, stash);
1926 }
1927
5d9574c1 1928 if (UNLIKELY(RX_ISTAINTED(rx))) {
e08e52cf 1929 SvTAINTED_on(rv);
9274aefd
DM
1930 SvTAINTED_on(SvRV(rv));
1931 }
c8c13c22 1932 XPUSHs(rv);
1933 RETURN;
8782bef2
GB
1934}
1935
a0d0e21e
LW
1936PP(pp_match)
1937{
20b7effb 1938 dSP; dTARG;
eb578fdb 1939 PMOP *pm = cPMOP;
d65afb4b 1940 PMOP *dynpm = pm;
eb578fdb 1941 const char *s;
5c144d81 1942 const char *strend;
99a90e59 1943 SSize_t curpos = 0; /* initial pos() or current $+[0] */
a0d0e21e 1944 I32 global;
7fadf4a7 1945 U8 r_flags = 0;
5c144d81 1946 const char *truebase; /* Start of string */
eb578fdb 1947 REGEXP *rx = PM_GETRE(pm);
b3eb6a9b 1948 bool rxtainted;
1c23e2bd 1949 const U8 gimme = GIMME_V;
a0d0e21e 1950 STRLEN len;
a3b680e6 1951 const I32 oldsave = PL_savestack_ix;
e60df1fa 1952 I32 had_zerolen = 0;
b1422d62 1953 MAGIC *mg = NULL;
a0d0e21e 1954
533c011a 1955 if (PL_op->op_flags & OPf_STACKED)
a0d0e21e
LW
1956 TARG = POPs;
1957 else {
9399c607
DM
1958 if (ARGTARG)
1959 GETTARGET;
1960 else {
1961 TARG = DEFSV;
1962 }
a0d0e21e
LW
1963 EXTEND(SP,1);
1964 }
d9f424b2 1965
c277df42 1966 PUTBACK; /* EVAL blocks need stack_sp. */
69dc4b30
FC
1967 /* Skip get-magic if this is a qr// clone, because regcomp has
1968 already done it. */
f1d31338 1969 truebase = ReANY(rx)->mother_re
69dc4b30
FC
1970 ? SvPV_nomg_const(TARG, len)
1971 : SvPV_const(TARG, len);
f1d31338 1972 if (!truebase)
2269b42e 1973 DIE(aTHX_ "panic: pp_match");
f1d31338 1974 strend = truebase + len;
284167a5
SM
1975 rxtainted = (RX_ISTAINTED(rx) ||
1976 (TAINT_get && (pm->op_pmflags & PMf_RETAINT)));
9212bbba 1977 TAINT_NOT;
a0d0e21e 1978
6c864ec2 1979 /* We need to know this in case we fail out early - pos() must be reset */
de0df3c0
MH
1980 global = dynpm->op_pmflags & PMf_GLOBAL;
1981
d65afb4b 1982 /* PMdf_USED is set after a ?? matches once */
c737faaf
YO
1983 if (
1984#ifdef USE_ITHREADS
1985 SvREADONLY(PL_regex_pad[pm->op_pmoffset])
1986#else
1987 pm->op_pmflags & PMf_USED
1988#endif
1989 ) {
e5dc5375 1990 DEBUG_r(PerlIO_printf(Perl_debug_log, "?? already matched once"));
de0df3c0 1991 goto nope;
a0d0e21e
LW
1992 }
1993
5585e758
YO
1994 /* handle the empty pattern */
1995 if (!RX_PRELEN(rx) && PL_curpm && !ReANY(rx)->mother_re) {
1996 if (PL_curpm == PL_reg_curpm) {
1997 if (PL_curpm_under) {
1998 if (PL_curpm_under == PL_reg_curpm) {
1999 Perl_croak(aTHX_ "Infinite recursion via empty pattern");
2000 } else {
2001 pm = PL_curpm_under;
2002 }
2003 }
2004 } else {
2005 pm = PL_curpm;
2006 }
2007 rx = PM_GETRE(pm);
a0d0e21e 2008 }
d65afb4b 2009
389ecb56 2010 if (RX_MINLEN(rx) >= 0 && (STRLEN)RX_MINLEN(rx) > len) {
75d43e96 2011 DEBUG_r(PerlIO_printf(Perl_debug_log, "String shorter than min possible regex match (%"
147e3846 2012 UVuf " < %" IVdf ")\n",
75d43e96 2013 (UV)len, (IV)RX_MINLEN(rx)));
de0df3c0 2014 goto nope;
e5dc5375 2015 }
c277df42 2016
8ef97b0e 2017 /* get pos() if //g */
de0df3c0 2018 if (global) {
b1422d62 2019 mg = mg_find_mglob(TARG);
8ef97b0e 2020 if (mg && mg->mg_len >= 0) {
25fdce4a 2021 curpos = MgBYTEPOS(mg, TARG, truebase, len);
8ef97b0e
DM
2022 /* last time pos() was set, it was zero-length match */
2023 if (mg->mg_flags & MGf_MINMATCH)
2024 had_zerolen = 1;
2025 }
a0d0e21e 2026 }
8ef97b0e 2027
6e240d0b 2028#ifdef PERL_SAWAMPERSAND
a41aa44d 2029 if ( RX_NPARENS(rx)
6502e081 2030 || PL_sawampersand
6502e081 2031 || (RX_EXTFLAGS(rx) & (RXf_EVAL_SEEN|RXf_PMf_KEEPCOPY))
5b0e71e9 2032 || (dynpm->op_pmflags & PMf_KEEPCOPY)
6e240d0b
FC
2033 )
2034#endif
2035 {
6502e081
DM
2036 r_flags |= (REXEC_COPY_STR|REXEC_COPY_SKIP_PRE);
2037 /* in @a =~ /(.)/g, we iterate multiple times, but copy the buffer
2038 * only on the first iteration. Therefore we need to copy $' as well
2039 * as $&, to make the rest of the string available for captures in
2040 * subsequent iterations */
2041 if (! (global && gimme == G_ARRAY))
2042 r_flags |= REXEC_COPY_SKIP_POST;
2043 };
5b0e71e9
DM
2044#ifdef PERL_SAWAMPERSAND
2045 if (dynpm->op_pmflags & PMf_KEEPCOPY)
2046 /* handle KEEPCOPY in pmop but not rx, eg $r=qr/a/; /$r/p */
2047 r_flags &= ~(REXEC_COPY_SKIP_PRE|REXEC_COPY_SKIP_POST);
2048#endif
22e551b9 2049
f1d31338
DM
2050 s = truebase;
2051
d7be1480 2052 play_it_again:
985afbc1 2053 if (global)
03c83e26 2054 s = truebase + curpos;
f722798b 2055
77da2310 2056 if (!CALLREGEXEC(rx, (char*)s, (char *)strend, (char*)truebase,
03c83e26 2057 had_zerolen, TARG, NULL, r_flags))
03b6c93d 2058 goto nope;
77da2310
NC
2059
2060 PL_curpm = pm;
985afbc1 2061 if (dynpm->op_pmflags & PMf_ONCE)
c737faaf 2062#ifdef USE_ITHREADS
77da2310 2063 SvREADONLY_on(PL_regex_pad[dynpm->op_pmoffset]);
c737faaf 2064#else
77da2310 2065 dynpm->op_pmflags |= PMf_USED;
c737faaf 2066#endif
a0d0e21e 2067
72311751
GS
2068 if (rxtainted)
2069 RX_MATCH_TAINTED_on(rx);
2070 TAINT_IF(RX_MATCH_TAINTED(rx));
35c2ccc3
DM
2071
2072 /* update pos */
2073
2074 if (global && (gimme != G_ARRAY || (dynpm->op_pmflags & PMf_CONTINUE))) {
b1422d62 2075 if (!mg)
35c2ccc3 2076 mg = sv_magicext_mglob(TARG);
25fdce4a 2077 MgBYTEPOS_set(mg, TARG, truebase, RX_OFFS(rx)[0].end);
adf51885
DM
2078 if (RX_ZERO_LEN(rx))
2079 mg->mg_flags |= MGf_MINMATCH;
2080 else
2081 mg->mg_flags &= ~MGf_MINMATCH;
35c2ccc3
DM
2082 }
2083
bf9dff51
DM
2084 if ((!RX_NPARENS(rx) && !global) || gimme != G_ARRAY) {
2085 LEAVE_SCOPE(oldsave);
2086 RETPUSHYES;
2087 }
2088
88ab22af
DM
2089 /* push captures on stack */
2090
bf9dff51 2091 {
07bc277f 2092 const I32 nparens = RX_NPARENS(rx);
a3b680e6 2093 I32 i = (global && !nparens) ? 1 : 0;
a0d0e21e 2094
c277df42 2095 SPAGAIN; /* EVAL blocks could move the stack. */
ffc61ed2
JH
2096 EXTEND(SP, nparens + i);
2097 EXTEND_MORTAL(nparens + i);
2098 for (i = !i; i <= nparens; i++) {
a0d0e21e 2099 PUSHs(sv_newmortal());
5d9574c1
DM
2100 if (LIKELY((RX_OFFS(rx)[i].start != -1)
2101 && RX_OFFS(rx)[i].end != -1 ))
2102 {
07bc277f 2103 const I32 len = RX_OFFS(rx)[i].end - RX_OFFS(rx)[i].start;
f1d31338 2104 const char * const s = RX_OFFS(rx)[i].start + truebase;
5d9574c1
DM
2105 if (UNLIKELY(RX_OFFS(rx)[i].end < 0 || RX_OFFS(rx)[i].start < 0
2106 || len < 0 || len > strend - s))
5637ef5b 2107 DIE(aTHX_ "panic: pp_match start/end pointers, i=%ld, "
147e3846 2108 "start=%ld, end=%ld, s=%p, strend=%p, len=%" UVuf,
5637ef5b
NC
2109 (long) i, (long) RX_OFFS(rx)[i].start,
2110 (long)RX_OFFS(rx)[i].end, s, strend, (UV) len);
a0d0e21e 2111 sv_setpvn(*SP, s, len);
cce850e4 2112 if (DO_UTF8(TARG) && is_utf8_string((U8*)s, len))
a197cbdd 2113 SvUTF8_on(*SP);
a0d0e21e
LW
2114 }
2115 }
2116 if (global) {
0e0b3e82 2117 curpos = (UV)RX_OFFS(rx)[0].end;
03c83e26 2118 had_zerolen = RX_ZERO_LEN(rx);
c277df42 2119 PUTBACK; /* EVAL blocks may use stack */
cf93c79d 2120 r_flags |= REXEC_IGNOREPOS | REXEC_NOT_FIRST;
a0d0e21e
LW
2121 goto play_it_again;
2122 }
4633a7c4 2123 LEAVE_SCOPE(oldsave);
a0d0e21e
LW
2124 RETURN;
2125 }
e5964223 2126 NOT_REACHED; /* NOTREACHED */
a0d0e21e 2127
7b52d656 2128 nope:
d65afb4b 2129 if (global && !(dynpm->op_pmflags & PMf_CONTINUE)) {
b1422d62
DM
2130 if (!mg)
2131 mg = mg_find_mglob(TARG);
2132 if (mg)
2133 mg->mg_len = -1;
a0d0e21e 2134 }
4633a7c4 2135 LEAVE_SCOPE(oldsave);
a0d0e21e
LW
2136 if (gimme == G_ARRAY)
2137 RETURN;
2138 RETPUSHNO;
2139}
2140
2141OP *
864dbfa3 2142Perl_do_readline(pTHX)
a0d0e21e 2143{
20b7effb 2144 dSP; dTARGETSTACKED;
eb578fdb 2145 SV *sv;
a0d0e21e
LW
2146 STRLEN tmplen = 0;
2147 STRLEN offset;
760ac839 2148 PerlIO *fp;
eb578fdb
KW
2149 IO * const io = GvIO(PL_last_in_gv);
2150 const I32 type = PL_op->op_type;
1c23e2bd 2151 const U8 gimme = GIMME_V;
a0d0e21e 2152
6136c704 2153 if (io) {
50db69d8 2154 const MAGIC *const mg = SvTIED_mg((const SV *)io, PERL_MAGIC_tiedscalar);
6136c704 2155 if (mg) {
3e0cb5de 2156 Perl_tied_method(aTHX_ SV_CONST(READLINE), SP, MUTABLE_SV(io), mg, gimme, 0);
6136c704 2157 if (gimme == G_SCALAR) {
50db69d8
NC
2158 SPAGAIN;
2159 SvSetSV_nosteal(TARG, TOPs);
2160 SETTARG;
6136c704 2161 }
50db69d8 2162 return NORMAL;
0b7c7b4f 2163 }
e79b0511 2164 }
4608196e 2165 fp = NULL;
a0d0e21e
LW
2166 if (io) {
2167 fp = IoIFP(io);
2168 if (!fp) {
2169 if (IoFLAGS(io) & IOf_ARGV) {
2170 if (IoFLAGS(io) & IOf_START) {
a0d0e21e 2171 IoLINES(io) = 0;
b9f2b683 2172 if (av_tindex(GvAVn(PL_last_in_gv)) < 0) {
1d7c1841 2173 IoFLAGS(io) &= ~IOf_START;
d5eb9a46 2174 do_open6(PL_last_in_gv, "-", 1, NULL, NULL, 0);
4bac9ae4 2175 SvTAINTED_off(GvSVn(PL_last_in_gv)); /* previous tainting irrelevant */
76f68e9b 2176 sv_setpvs(GvSVn(PL_last_in_gv), "-");
3280af22 2177 SvSETMAGIC(GvSV(PL_last_in_gv));
a2008d6d
GS
2178 fp = IoIFP(io);
2179 goto have_fp;
a0d0e21e
LW
2180 }
2181 }
157fb5a1 2182 fp = nextargv(PL_last_in_gv, PL_op->op_flags & OPf_SPECIAL);
a0d0e21e 2183 if (!fp) { /* Note: fp != IoIFP(io) */
3280af22 2184 (void)do_close(PL_last_in_gv, FALSE); /* now it does*/
a0d0e21e
LW
2185 }
2186 }
0d44d22b
NC
2187 else if (type == OP_GLOB)
2188 fp = Perl_start_glob(aTHX_ POPs, io);
a0d0e21e
LW
2189 }
2190 else if (type == OP_GLOB)
2191 SP--;
7716c5c5 2192 else if (IoTYPE(io) == IoTYPE_WRONLY) {
a5390457 2193 report_wrongway_fh(PL_last_in_gv, '>');
a00b5bd3 2194 }
a0d0e21e
LW
2195 }
2196 if (!fp) {
041457d9 2197 if ((!io || !(IoFLAGS(io) & IOf_START))
de7dabb6
TC
2198 && ckWARN(WARN_CLOSED)
2199 && type != OP_GLOB)
041457d9 2200 {
de7dabb6 2201 report_evil_fh(PL_last_in_gv);
3f4520fe 2202 }
54310121 2203 if (gimme == G_SCALAR) {
79628082 2204 /* undef TARG, and push that undefined value */
ba92458f 2205 if (type != OP_RCATLINE) {
aab1202a 2206 sv_setsv(TARG,NULL);
ba92458f 2207 }
a0d0e21e
LW
2208 PUSHTARG;
2209 }
2210 RETURN;
2211 }
a2008d6d 2212 have_fp:
54310121 2213 if (gimme == G_SCALAR) {
a0d0e21e 2214 sv = TARG;
0f722b55
RGS
2215 if (type == OP_RCATLINE && SvGMAGICAL(sv))
2216 mg_get(sv);
48de12d9
RGS
2217 if (SvROK(sv)) {
2218 if (type == OP_RCATLINE)
5668452f 2219 SvPV_force_nomg_nolen(sv);
48de12d9
RGS
2220 else
2221 sv_unref(sv);
2222 }
f7877b28 2223 else if (isGV_with_GP(sv)) {
5668452f 2224 SvPV_force_nomg_nolen(sv);
f7877b28 2225 }
862a34c6 2226 SvUPGRADE(sv, SVt_PV);
a0d0e21e 2227 tmplen = SvLEN(sv); /* remember if already alloced */
e3918bb7 2228 if (!tmplen && !SvREADONLY(sv) && !SvIsCOW(sv)) {
f72e8700
JJ
2229 /* try short-buffering it. Please update t/op/readline.t
2230 * if you change the growth length.
2231 */
2232 Sv_Grow(sv, 80);
2233 }
2b5e58c4
AMS
2234 offset = 0;
2235 if (type == OP_RCATLINE && SvOK(sv)) {
2236 if (!SvPOK(sv)) {
5668452f 2237 SvPV_force_nomg_nolen(sv);
2b5e58c4 2238 }
a0d0e21e 2239 offset = SvCUR(sv);
2b5e58c4 2240 }
a0d0e21e 2241 }
54310121 2242 else {
561b68a9 2243 sv = sv_2mortal(newSV(80));
54310121
PP
2244 offset = 0;
2245 }
fbad3eb5 2246
3887d568
AP
2247 /* This should not be marked tainted if the fp is marked clean */
2248#define MAYBE_TAINT_LINE(io, sv) \
2249 if (!(IoFLAGS(io) & IOf_UNTAINT)) { \
2250 TAINT; \
2251 SvTAINTED_on(sv); \
2252 }
2253
684bef36 2254/* delay EOF state for a snarfed empty file */
fbad3eb5 2255#define SNARF_EOF(gimme,rs,io,sv) \
684bef36 2256 (gimme != G_SCALAR || SvCUR(sv) \
b9fee9ba 2257 || (IoFLAGS(io) & IOf_NOLINE) || !RsSNARF(rs))
fbad3eb5 2258
a0d0e21e 2259 for (;;) {
09e8efcc 2260 PUTBACK;
fbad3eb5 2261 if (!sv_gets(sv, fp, offset)
2d726892
TF
2262 && (type == OP_GLOB
2263 || SNARF_EOF(gimme, PL_rs, io, sv)
2264 || PerlIO_error(fp)))
fbad3eb5 2265 {
760ac839 2266 PerlIO_clearerr(fp);
a0d0e21e 2267 if (IoFLAGS(io) & IOf_ARGV) {
157fb5a1 2268 fp = nextargv(PL_last_in_gv, PL_op->op_flags & OPf_SPECIAL);
a0d0e21e
LW
2269 if (fp)
2270 continue;
3280af22 2271 (void)do_close(PL_last_in_gv, FALSE);
a0d0e21e
LW
2272 }
2273 else if (type == OP_GLOB) {
a2a5de95
NC
2274 if (!do_close(PL_last_in_gv, FALSE)) {
2275 Perl_ck_warner(aTHX_ packWARN(WARN_GLOB),
2276 "glob failed (child exited with status %d%s)",
2277 (int)(STATUS_CURRENT >> 8),
2278 (STATUS_CURRENT & 0x80) ? ", core dumped" : "");
4eb79ab5 2279 }
a0d0e21e 2280 }
54310121 2281 if (gimme == G_SCALAR) {
ba92458f
AE
2282 if (type != OP_RCATLINE) {
2283 SV_CHECK_THINKFIRST_COW_DROP(TARG);
0c34ef67 2284 SvOK_off(TARG);
ba92458f 2285 }
09e8efcc 2286 SPAGAIN;
a0d0e21e
LW
2287 PUSHTARG;
2288 }
3887d568 2289 MAYBE_TAINT_LINE(io, sv);
a0d0e21e
LW
2290 RETURN;
2291 }
3887d568 2292 MAYBE_TAINT_LINE(io, sv);
a0d0e21e 2293 IoLINES(io)++;
b9fee9ba 2294 IoFLAGS(io) |= IOf_NOLINE;
71be2cbc 2295 SvSETMAGIC(sv);
09e8efcc 2296 SPAGAIN;
a0d0e21e 2297 XPUSHs(sv);
a0d0e21e 2298 if (type == OP_GLOB) {
349d4f2f 2299 const char *t1;
45a23732 2300 Stat_t statbuf;
a0d0e21e 2301
3280af22 2302 if (SvCUR(sv) > 0 && SvCUR(PL_rs) > 0) {
6136c704 2303 char * const tmps = SvEND(sv) - 1;
aa07b2f6 2304 if (*tmps == *SvPVX_const(PL_rs)) {
c07a80fd 2305 *tmps = '\0';
b162af07 2306 SvCUR_set(sv, SvCUR(sv) - 1);
c07a80fd
PP
2307 }
2308 }
349d4f2f 2309 for (t1 = SvPVX_const(sv); *t1; t1++)
b51c3e77
CB
2310#ifdef __VMS
2311 if (strchr("*%?", *t1))
2312#else
7ad1e72d 2313 if (strchr("$&*(){}[]'\";\\|?<>~`", *t1))
b51c3e77 2314#endif
a0d0e21e 2315 break;
45a23732 2316 if (*t1 && PerlLIO_lstat(SvPVX_const(sv), &statbuf) < 0) {
a0d0e21e
LW
2317 (void)POPs; /* Unmatched wildcard? Chuck it... */
2318 continue;
2319 }
2d79bf7f 2320 } else if (SvUTF8(sv)) { /* OP_READLINE, OP_RCATLINE */
d4c19fe8
AL
2321 if (ckWARN(WARN_UTF8)) {
2322 const U8 * const s = (const U8*)SvPVX_const(sv) + offset;
2323 const STRLEN len = SvCUR(sv) - offset;
2324 const U8 *f;
2325
2326 if (!is_utf8_string_loc(s, len, &f))
2327 /* Emulate :encoding(utf8) warning in the same case. */
2328 Perl_warner(aTHX_ packWARN(WARN_UTF8),
2329 "utf8 \"\\x%02X\" does not map to Unicode",
2330 f < (U8*)SvEND(sv) ? *f : 0);
2331 }
a0d0e21e 2332 }
54310121 2333 if (gimme == G_ARRAY) {
a0d0e21e 2334 if (SvLEN(sv) - SvCUR(sv) > 20) {
1da4ca5f 2335 SvPV_shrink_to_cur(sv);
a0d0e21e 2336 }
561b68a9 2337 sv = sv_2mortal(newSV(80));
a0d0e21e
LW
2338 continue;
2339 }
54310121 2340 else if (gimme == G_SCALAR && !tmplen && SvLEN(sv) - SvCUR(sv) > 80) {
a0d0e21e 2341 /* try to reclaim a bit of scalar space (only on 1st alloc) */
d5b5861b
NC
2342 const STRLEN new_len
2343 = SvCUR(sv) < 60 ? 80 : SvCUR(sv)+40; /* allow some slop */
1da4ca5f 2344 SvPV_renew(sv, new_len);
a0d0e21e
LW
2345 }
2346 RETURN;
2347 }
2348}
2349
a0d0e21e
LW
2350PP(pp_helem)
2351{
20b7effb 2352 dSP;
760ac839 2353 HE* he;
ae77835f 2354 SV **svp;
c445ea15 2355 SV * const keysv = POPs;
85fbaab2 2356 HV * const hv = MUTABLE_HV(POPs);
a3b680e6
AL
2357 const U32 lval = PL_op->op_flags & OPf_MOD || LVRET;
2358 const U32 defer = PL_op->op_private & OPpLVAL_DEFER;
be6c24e0 2359 SV *sv;
92970b93 2360 const bool localizing = PL_op->op_private & OPpLVAL_INTRO;
d30e492c 2361 bool preeminent = TRUE;
a0d0e21e 2362
6dfc73ea
SM
2363 if (SvTYPE(hv) != SVt_PVHV)
2364 RETPUSHUNDEF;
d4c19fe8 2365
92970b93 2366 if (localizing) {
d4c19fe8
AL
2367 MAGIC *mg;
2368 HV *stash;
d30e492c
VP
2369
2370 /* If we can determine whether the element exist,
2371 * Try to preserve the existenceness of a tied hash
2372 * element by using EXISTS and DELETE if possible.
2373 * Fallback to FETCH and STORE otherwise. */
2c5f48c2 2374 if (SvCANEXISTDELETE(hv))
d30e492c 2375 preeminent = hv_exists_ent(hv, keysv, 0);
d4c19fe8 2376 }
d30e492c 2377
5f9d7e2b 2378 he = hv_fetch_ent(hv, keysv, lval && !defer, 0);
d4c19fe8 2379 svp = he ? &HeVAL(he) : NULL;
a0d0e21e 2380 if (lval) {
746f6409 2381 if (!svp || !*svp || *svp == &PL_sv_undef) {
68dc0745
PP
2382 SV* lv;
2383 SV* key2;
2d8e6c8d 2384 if (!defer) {
be2597df 2385 DIE(aTHX_ PL_no_helem_sv, SVfARG(keysv));
2d8e6c8d 2386 }
68dc0745
PP
2387 lv = sv_newmortal();
2388 sv_upgrade(lv, SVt_PVLV);
2389 LvTYPE(lv) = 'y';
6136c704 2390 sv_magic(lv, key2 = newSVsv(keysv), PERL_MAGIC_defelem, NULL, 0);
fc2b2dca 2391 SvREFCNT_dec_NN(key2); /* sv_magic() increments refcount */
0ad694a7 2392 LvTARG(lv) = SvREFCNT_inc_simple_NN(hv);
68dc0745
PP
2393 LvTARGLEN(lv) = 1;
2394 PUSHs(lv);
2395 RETURN;
2396 }
92970b93 2397 if (localizing) {
bfcb3514 2398 if (HvNAME_get(hv) && isGV(*svp))
159b6efe 2399 save_gp(MUTABLE_GV(*svp), !(PL_op->op_flags & OPf_SPECIAL));
47cfc530
VP
2400 else if (preeminent)
2401 save_helem_flags(hv, keysv, svp,
2402 (PL_op->op_flags & OPf_SPECIAL) ? 0 : SAVEf_SETMAGIC);
2403 else
2404 SAVEHDELETE(hv, keysv);
5f05dabc 2405 }
9026059d
GG
2406 else if (PL_op->op_private & OPpDEREF) {
2407 PUSHs(vivify_ref(*svp, PL_op->op_private & OPpDEREF));
2408 RETURN;
2409 }
a0d0e21e 2410 }
746f6409 2411 sv = (svp && *svp ? *svp : &PL_sv_undef);
fd69380d
DM
2412 /* Originally this did a conditional C<sv = sv_mortalcopy(sv)>; this
2413 * was to make C<local $tied{foo} = $tied{foo}> possible.
2414 * However, it seems no longer to be needed for that purpose, and
2415 * introduced a new bug: stuff like C<while ($hash{taintedval} =~ /.../g>
2416 * would loop endlessly since the pos magic is getting set on the
2417 * mortal copy and lost. However, the copy has the effect of
2418 * triggering the get magic, and losing it altogether made things like
2419 * c<$tied{foo};> in void context no longer do get magic, which some
2420 * code relied on. Also, delayed triggering of magic on @+ and friends
2421 * meant the original regex may be out of scope by now. So as a
2422 * compromise, do the get magic here. (The MGf_GSKIP flag will stop it
2423 * being called too many times). */
39cf747a 2424 if (!lval && SvRMAGICAL(hv) && SvGMAGICAL(sv))
fd69380d 2425 mg_get(sv);
be6c24e0 2426 PUSHs(sv);
a0d0e21e
LW
2427 RETURN;
2428}
2429
fedf30e1
DM
2430
2431/* a stripped-down version of Perl_softref2xv() for use by
2432 * pp_multideref(), which doesn't use PL_op->op_flags */
2433
f9db5646 2434STATIC GV *
fedf30e1
DM
2435S_softref2xv_lite(pTHX_ SV *const sv, const char *const what,
2436 const svtype type)
2437{
2438 if (PL_op->op_private & HINT_STRICT_REFS) {
2439 if (SvOK(sv))
2440 Perl_die(aTHX_ PL_no_symref_sv, sv,
2441 (SvPOKp(sv) && SvCUR(sv)>32 ? "..." : ""), what);
2442 else
2443 Perl_die(aTHX_ PL_no_usym, what);
2444 }
2445 if (!SvOK(sv))
2446 Perl_die(aTHX_ PL_no_usym, what);
2447 return gv_fetchsv_nomg(sv, GV_ADD, type);
2448}
2449
2450
79815f56
DM
2451/* Handle one or more aggregate derefs and array/hash indexings, e.g.
2452 * $h->{foo} or $a[0]{$key}[$i] or f()->[1]
fedf30e1
DM
2453 *
2454 * op_aux points to an array of unions of UV / IV / SV* / PADOFFSET.
79815f56
DM
2455 * Each of these either contains a set of actions, or an argument, such as
2456 * an IV to use as an array index, or a lexical var to retrieve.
2457 * Several actions re stored per UV; we keep shifting new actions off the
2458 * one UV, and only reload when it becomes zero.
fedf30e1
DM
2459 */
2460
2461PP(pp_multideref)
2462{
2463 SV *sv = NULL; /* init to avoid spurious 'may be used uninitialized' */
2464 UNOP_AUX_item *items = cUNOP_AUXx(PL_op)->op_aux;
2465 UV actions = items->uv;
2466
2467 assert(actions);
2468 /* this tells find_uninit_var() where we're up to */
2469 PL_multideref_pc = items;
2470
2471 while (1) {
2472 /* there are three main classes of action; the first retrieve
2473 * the initial AV or HV from a variable or the stack; the second
2474 * does the equivalent of an unrolled (/DREFAV, rv2av, aelem),
2475 * the third an unrolled (/DREFHV, rv2hv, helem).
2476 */
2477 switch (actions & MDEREF_ACTION_MASK) {
2478
2479 case MDEREF_reload:
2480 actions = (++items)->uv;
2481 continue;
2482
2483 case MDEREF_AV_padav_aelem: /* $lex[...] */
2484 sv = PAD_SVl((++items)->pad_offset);
2485 goto do_AV_aelem;
2486
2487 case MDEREF_AV_gvav_aelem: /* $pkg[...] */
2488 sv = UNOP_AUX_item_sv(++items);
2489 assert(isGV_with_GP(sv));
2490 sv = (SV*)GvAVn((GV*)sv);
2491 goto do_AV_aelem;
2492
2493 case MDEREF_AV_pop_rv2av_aelem: /* expr->[...] */
2494 {
2495 dSP;
2496 sv = POPs;
2497 PUTBACK;
2498 goto do_AV_rv2av_aelem;
2499 }
2500
2501 case MDEREF_AV_gvsv_vivify_rv2av_aelem: /* $pkg->[...] */
2502 sv = UNOP_AUX_item_sv(++items);
2503 assert(isGV_with_GP(sv));
2504 sv = GvSVn((GV*)sv);
2505 goto do_AV_vivify_rv2av_aelem;
2506
2507 case MDEREF_AV_padsv_vivify_rv2av_aelem: /* $lex->[...] */
2508 sv = PAD_SVl((++items)->pad_offset);
2509 /* FALLTHROUGH */
2510
2511 do_AV_vivify_rv2av_aelem:
2512 case MDEREF_AV_vivify_rv2av_aelem: /* vivify, ->[...] */
2513 /* this is the OPpDEREF action normally found at the end of
2514 * ops like aelem, helem, rv2sv */
2515 sv = vivify_ref(sv, OPpDEREF_AV);
2516 /* FALLTHROUGH */
2517
2518 do_AV_rv2av_aelem:
2519 /* this is basically a copy of pp_rv2av when it just has the
2520 * sKR/1 flags */
2521 SvGETMAGIC(sv);
2522 if (LIKELY(SvROK(sv))) {
2523 if (UNLIKELY(SvAMAGIC(sv))) {
2524 sv = amagic_deref_call(sv, to_av_amg);
2525 }
2526 sv = SvRV(sv);
2527 if (UNLIKELY(SvTYPE(sv) != SVt_PVAV))
2528 DIE(aTHX_ "Not an ARRAY reference");
2529 }
2530 else if (SvTYPE(sv) != SVt_PVAV) {
2531 if (!isGV_with_GP(sv))
2532 sv = (SV*)S_softref2xv_lite(aTHX_ sv, "an ARRAY", SVt_PVAV);
2533 sv = MUTABLE_SV(GvAVn((GV*)sv));
2534 }
2535 /* FALLTHROUGH */
2536
2537 do_AV_aelem:
2538 {
2539 /* retrieve the key; this may be either a lexical or package
2540 * var (whose index/ptr is stored as an item) or a signed
2541 * integer constant stored as an item.
2542 */
2543 SV *elemsv;
2544 IV elem = 0; /* to shut up stupid compiler warnings */
2545
2546
2547 assert(SvTYPE(sv) == SVt_PVAV);
2548
2549 switch (actions & MDEREF_INDEX_MASK) {
2550 case MDEREF_INDEX_none:
2551 goto finish;
2552 case MDEREF_INDEX_const:
2553 elem = (++items)->iv;
2554 break;
2555 case MDEREF_INDEX_padsv:
2556 elemsv = PAD_SVl((++items)->pad_offset);
2557 goto check_elem;
2558 case MDEREF_INDEX_gvsv:
2559 elemsv = UNOP_AUX_item_sv(++items);
2560 assert(isGV_with_GP(elemsv));
2561 elemsv = GvSVn((GV*)elemsv);
2562 check_elem:
2563 if (UNLIKELY(SvROK(elemsv) && !SvGAMAGIC(elemsv)
2564 && ckWARN(WARN_MISC)))
2565 Perl_warner(aTHX_ packWARN(WARN_MISC),
147e3846 2566 "Use of reference \"%" SVf "\" as array index",
fedf30e1
DM
2567 SVfARG(elemsv));
2568 /* the only time that S_find_uninit_var() needs this
2569 * is to determine which index value triggered the
2570 * undef warning. So just update it here. Note that
2571 * since we don't save and restore this var (e.g. for
2572 * tie or overload execution), its value will be
2573 * meaningless apart from just here */
2574 PL_multideref_pc = items;
2575 elem = SvIV(elemsv);
2576 break;
2577 }
2578
2579
2580 /* this is basically a copy of pp_aelem with OPpDEREF skipped */
2581
2582 if (!(actions & MDEREF_FLAG_last)) {
2583 SV** svp = av_fetch((AV*)sv, elem, 1);
2584 if (!svp || ! (sv=*svp))
2585 DIE(aTHX_ PL_no_aelem, elem);
2586 break;
2587 }
2588
2589 if (PL_op->op_private &
2590 (OPpMULTIDEREF_EXISTS|OPpMULTIDEREF_DELETE))
2591 {
2592 if (PL_op->op_private & OPpMULTIDEREF_EXISTS) {
2593 sv = av_exists((AV*)sv, elem) ? &PL_sv_yes : &PL_sv_no;
2594 }
2595 else {
2596 I32 discard = (GIMME_V == G_VOID) ? G_DISCARD : 0;
2597 sv = av_delete((AV*)sv, elem, discard);
2598 if (discard)
2599 return NORMAL;
2600 if (!sv)
2601 sv = &PL_sv_undef;
2602 }
2603 }
2604 else {
2605 const U32 lval = PL_op->op_flags & OPf_MOD || LVRET;
2606 const U32 defer = PL_op->op_private & OPpLVAL_DEFER;
2607 const bool localizing = PL_op->op_private & OPpLVAL_INTRO;
2608 bool preeminent = TRUE;
2609 AV *const av = (AV*)sv;
2610 SV** svp;
2611
2612 if (UNLIKELY(localizing)) {
2613 MAGIC *mg;
2614 HV *stash;
2615
2616 /* If we can determine whether the element exist,
2617 * Try to preserve the existenceness of a tied array
2618 * element by using EXISTS and DELETE if possible.
2619 * Fallback to FETCH and STORE otherwise. */
2620 if (SvCANEXISTDELETE(av))
2621 preeminent = av_exists(av, elem);
2622 }
2623
2624 svp = av_fetch(av, elem, lval && !defer);
2625
2626 if (lval) {
2627 if (!svp || !(sv = *svp)) {
2628 IV len;
2629 if (!defer)
2630 DIE(aTHX_ PL_no_aelem, elem);
2631 len = av_tindex(av);
2632 sv = sv_2mortal(newSVavdefelem(av,
2633 /* Resolve a negative index now, unless it points
2634 * before the beginning of the array, in which
2635 * case record it for error reporting in
2636 * magic_setdefelem. */
2637 elem < 0 && len + elem >= 0
2638 ? len + elem : elem, 1));
2639 }
2640 else {
2641 if (UNLIKELY(localizing)) {
2642 if (preeminent) {
2643 save_aelem(av, elem, svp);
2644 sv = *svp; /* may have changed */
2645 }
2646 else
2647 SAVEADELETE(av, elem);
2648 }
2649 }
2650 }
2651 else {
2652 sv = (svp ? *svp : &PL_sv_undef);
2653 /* see note in pp_helem() */
2654 if (SvRMAGICAL(av) && SvGMAGICAL(sv))
2655 mg_get(sv);
2656 }
2657 }
2658
2659 }
2660 finish:
2661 {
2662 dSP;
2663 XPUSHs(sv);
2664 RETURN;
2665 }
2666 /* NOTREACHED */
2667
2668
2669
2670
2671 case MDEREF_HV_padhv_helem: /* $lex{...} */
2672 sv = PAD_SVl((++items)->pad_offset);
2673 goto do_HV_helem;
2674
2675 case MDEREF_HV_gvhv_helem: /* $pkg{...} */
2676 sv = UNOP_AUX_item_sv(++items);
2677 assert(isGV_with_GP(sv));
2678 sv = (SV*)GvHVn((GV*)sv);
2679 goto do_HV_helem;
2680
2681 case MDEREF_HV_pop_rv2hv_helem: /* expr->{...} */
2682 {
2683 dSP;
2684 sv = POPs;
2685 PUTBACK;
2686 goto do_HV_rv2hv_helem;
2687 }
2688
2689 case MDEREF_HV_gvsv_vivify_rv2hv_helem: /* $pkg->{...} */
2690 sv = UNOP_AUX_item_sv(++items);
2691 assert(isGV_with_GP(sv));
2692 sv = GvSVn((GV*)sv);
2693 goto do_HV_vivify_rv2hv_helem;
2694
2695 case MDEREF_HV_padsv_vivify_rv2hv_helem: /* $lex->{...} */
2696 sv = PAD_SVl((++items)->pad_offset);
2697 /* FALLTHROUGH */
2698
2699 do_HV_vivify_rv2hv_helem:
2700 case MDEREF_HV_vivify_rv2hv_helem: /* vivify, ->{...} */
2701 /* this is the OPpDEREF action normally found at the end of
2702 * ops like aelem, helem, rv2sv */
2703 sv = vivify_ref(sv, OPpDEREF_HV);
2704 /* FALLTHROUGH */
2705
2706 do_HV_rv2hv_helem:
2707 /* this is basically a copy of pp_rv2hv when it just has the
2708 * sKR/1 flags (and pp_rv2hv is aliased to pp_rv2av) */
2709
2710 SvGETMAGIC(sv);
2711 if (LIKELY(SvROK(sv))) {
2712 if (UNLIKELY(SvAMAGIC(sv))) {
2713 sv = amagic_deref_call(sv, to_hv_amg);
2714 }
2715 sv = SvRV(sv);
2716 if (UNLIKELY(SvTYPE(sv) != SVt_PVHV))
2717 DIE(aTHX_ "Not a HASH reference");
2718 }
2719 else if (SvTYPE(sv) != SVt_PVHV) {
2720 if (!isGV_with_GP(sv))
2721 sv = (SV*)S_softref2xv_lite(aTHX_ sv, "a HASH", SVt_PVHV);
2722 sv = MUTABLE_SV(GvHVn((GV*)sv));
2723 }
2724 /* FALLTHROUGH */
2725
2726 do_HV_helem:
2727 {
2728 /* retrieve the key; this may be either a lexical / package
2729 * var or a string constant, whose index/ptr is stored as an
2730 * item
2731 */
2732 SV *keysv = NULL; /* to shut up stupid compiler warnings */
2733
2734 assert(SvTYPE(sv) == SVt_PVHV);
2735
2736 switch (actions & MDEREF_INDEX_MASK) {
2737 case MDEREF_INDEX_none:
2738 goto finish;
2739
2740 case MDEREF_INDEX_const:
2741 keysv = UNOP_AUX_item_sv(++items);
2742 break;
2743
2744 case MDEREF_INDEX_padsv:
2745 keysv = PAD_SVl((++items)->pad_offset);
2746 break;
2747
2748 case MDEREF_INDEX_gvsv:
2749 keysv = UNOP_AUX_item_sv(++items);
2750 keysv = GvSVn((GV*)keysv);
2751 break;
2752 }
2753
2754 /* see comment above about setting this var */
2755 PL_multideref_pc = items;
2756
2757
2758 /* ensure that candidate CONSTs have been HEKified */
2759 assert( ((actions & MDEREF_INDEX_MASK) != MDEREF_INDEX_const)
2760 || SvTYPE(keysv) >= SVt_PVMG
2761 || !SvOK(keysv)
2762 || SvROK(keysv)
2763 || SvIsCOW_shared_hash(keysv));
2764
2765 /* this is basically a copy of pp_helem with OPpDEREF skipped */
2766
2767 if (!(actions & MDEREF_FLAG_last)) {
2768 HE *he = hv_fetch_ent((HV*)sv, keysv, 1, 0);
2769 if (!he || !(sv=HeVAL(he)) || sv == &PL_sv_undef)
2770 DIE(aTHX_ PL_no_helem_sv, SVfARG(keysv));
2771 break;
2772 }
2773
2774 if (PL_op->op_private &
2775 (OPpMULTIDEREF_EXISTS|OPpMULTIDEREF_DELETE))
2776 {
2777 if (PL_op->op_private & OPpMULTIDEREF_EXISTS) {
2778 sv = hv_exists_ent((HV*)sv, keysv, 0)
2779 ? &PL_sv_yes : &PL_sv_no;
2780 }
2781 else {
2782 I32 discard = (GIMME_V == G_VOID) ? G_DISCARD : 0;
2783 sv = hv_delete_ent((HV*)sv, keysv, discard, 0);
2784 if (discard)
2785 return NORMAL;
2786 if (!sv)
2787 sv = &PL_sv_undef;
2788 }
2789 }
2790 else {
2791 const U32 lval = PL_op->op_flags & OPf_MOD || LVRET;
2792 const U32 defer = PL_op->op_private & OPpLVAL_DEFER;
2793 const bool localizing = PL_op->op_private & OPpLVAL_INTRO;
2794 bool preeminent = TRUE;
2795 SV **svp;
2796 HV * const hv = (HV*)sv;
2797 HE* he;
2798
2799 if (UNLIKELY(localizing)) {
2800 MAGIC *mg;
2801 HV *stash;
2802
2803 /* If we can determine whether the element exist,
2804 * Try to preserve the existenceness of a tied hash
2805 * element by using EXISTS and DELETE if possible.
2806 * Fallback to FETCH and STORE otherwise. */
2807 if (SvCANEXISTDELETE(hv))
2808 preeminent = hv_exists_ent(hv, keysv, 0);
2809 }
2810
2811 he = hv_fetch_ent(hv, keysv, lval && !defer, 0);
2812 svp = he ? &HeVAL(he) : NULL;
2813
2814
2815 if (lval) {
2816 if (!svp || !(sv = *svp) || sv == &PL_sv_undef) {
2817 SV* lv;
2818 SV* key2;
2819 if (!defer)
2820 DIE(aTHX_ PL_no_helem_sv, SVfARG(keysv));
2821 lv = sv_newmortal();
2822 sv_upgrade(lv, SVt_PVLV);
2823 LvTYPE(lv) = 'y';
2824 sv_magic(lv, key2 = newSVsv(keysv),
2825 PERL_MAGIC_defelem, NULL, 0);
2826 /* sv_magic() increments refcount */
2827 SvREFCNT_dec_NN(key2);
0ad694a7 2828 LvTARG(lv) = SvREFCNT_inc_simple_NN(hv);
fedf30e1
DM
2829 LvTARGLEN(lv) = 1;
2830 sv = lv;
2831 }
2832 else {
2833 if (localizing) {
2834 if (HvNAME_get(hv) && isGV(sv))
2835 save_gp(MUTABLE_GV(sv),
2836 !(PL_op->op_flags & OPf_SPECIAL));
2837 else if (preeminent) {
2838 save_helem_flags(hv, keysv, svp,
2839 (PL_op->op_flags & OPf_SPECIAL)
2840 ? 0 : SAVEf_SETMAGIC);
2841 sv = *svp; /* may have changed */
2842 }
2843 else
2844 SAVEHDELETE(hv, keysv);
2845 }
2846 }
2847 }
2848 else {
2849 sv = (svp && *svp ? *svp : &PL_sv_undef);
2850 /* see note in pp_helem() */
2851 if (SvRMAGICAL(hv) && SvGMAGICAL(sv))
2852 mg_get(sv);
2853 }
2854 }
2855 goto finish;
2856 }
2857
2858 } /* switch */
2859
2860 actions >>= MDEREF_SHIFT;
2861 } /* while */
2862 /* NOTREACHED */
2863}
2864
2865
a0d0e21e
LW
2866PP(pp_iter)
2867{
eb578fdb 2868 PERL_CONTEXT *cx;
7d6c2cef 2869 SV *oldsv;
1d7c1841 2870 SV **itersvp;
8a1f10dd 2871 SV *retsv;
a0d0e21e 2872
84f05d57
JH
2873 SV *sv;
2874 AV *av;
2875 IV ix;
2876 IV inc;
2877
4ebe6e95 2878 cx = CX_CUR();
1d7c1841 2879 itersvp = CxITERVAR(cx);
4b5c941e 2880 assert(itersvp);
a48ce6be
DM
2881
2882 switch (CxTYPE(cx)) {
17c91640 2883
b552b52c
DM
2884 case CXt_LOOP_LAZYSV: /* string increment */
2885 {
2886 SV* cur = cx->blk_loop.state_u.lazysv.cur;
2887 SV *end = cx->blk_loop.state_u.lazysv.end;
2888 /* If the maximum is !SvOK(), pp_enteriter substitutes PL_sv_no.
2889 It has SvPVX of "" and SvCUR of 0, which is what we want. */
2890 STRLEN maxlen = 0;
2891 const char *max = SvPV_const(end, maxlen);
d6c970c7
AC
2892 if (DO_UTF8(end) && IN_UNI_8_BIT)
2893 maxlen = sv_len_utf8_nomg(end);
5d9574c1 2894 if (UNLIKELY(SvNIOK(cur) || SvCUR(cur) > maxlen))
8a1f10dd 2895 goto retno;
b552b52c
DM
2896
2897 oldsv = *itersvp;
6d3ca00e
DM
2898 /* NB: on the first iteration, oldsv will have a ref count of at
2899 * least 2 (one extra from blk_loop.itersave), so the GV or pad
2900 * slot will get localised; on subsequent iterations the RC==1
2901 * optimisation may kick in and the SV will be reused. */
2902 if (oldsv && LIKELY(SvREFCNT(oldsv) == 1 && !SvMAGICAL(oldsv))) {
b552b52c
DM
2903 /* safe to reuse old SV */
2904 sv_setsv(oldsv, cur);
a48ce6be 2905 }
b552b52c
DM
2906 else
2907 {
2908 /* we need a fresh SV every time so that loop body sees a
2909 * completely new SV for closures/references to work as
2910 * they used to */
2911 *itersvp = newSVsv(cur);
6d3ca00e 2912 SvREFCNT_dec(oldsv);
b552b52c
DM
2913 }
2914 if (strEQ(SvPVX_const(cur), max))
2915 sv_setiv(cur, 0); /* terminate next time */
2916 else
2917 sv_inc(cur);
2918 break;
2919 }
a48ce6be 2920
fcef60b4
DM
2921 case CXt_LOOP_LAZYIV: /* integer increment */
2922 {
2923 IV cur = cx->blk_loop.state_u.lazyiv.cur;
5d9574c1 2924 if (UNLIKELY(cur > cx->blk_loop.state_u.lazyiv.end))
8a1f10dd 2925 goto retno;
7f61b687 2926
fcef60b4 2927 oldsv = *itersvp;
6d3ca00e
DM
2928 /* see NB comment above */
2929 if (oldsv && LIKELY(SvREFCNT(oldsv) == 1 && !SvMAGICAL(oldsv))) {
eaa5c2d6 2930 /* safe to reuse old SV */
47b96a1e
DM
2931
2932 if ( (SvFLAGS(oldsv) & (SVTYPEMASK|SVf_THINKFIRST|SVf_IVisUV))
2933 == SVt_IV)
2934 {
2935 /* Cheap SvIOK_only().
2936 * Assert that flags which SvIOK_only() would test or
2937 * clear can't be set, because we're SVt_IV */
2938 assert(!(SvFLAGS(oldsv) &
2939 (SVf_OOK|SVf_UTF8|(SVf_OK & ~(SVf_IOK|SVp_IOK)))));
2940 SvFLAGS(oldsv) |= (SVf_IOK|SVp_IOK);
2941 /* SvIV_set() where sv_any points to head */
2942 oldsv->sv_u.svu_iv = cur;
2943
2944 }
2945 else
2946 sv_setiv(oldsv, cur);
eaa5c2d6 2947 }
1c846c1f 2948 else
eaa5c2d6
GA
2949 {
2950 /* we need a fresh SV every time so that loop body sees a
2951 * completely new SV for closures/references to work as they
2952 * used to */
fcef60b4 2953 *itersvp = newSViv(cur);
6d3ca00e 2954 SvREFCNT_dec(oldsv);
eaa5c2d6 2955 }
a2309040 2956
5d9574c1 2957 if (UNLIKELY(cur == IV_MAX)) {
cdc1aa42
NC
2958 /* Handle end of range at IV_MAX */
2959 cx->blk_loop.state_u.lazyiv.end = IV_MIN;
2960 } else
2961 ++cx->blk_loop.state_u.lazyiv.cur;
a48ce6be 2962 break;
fcef60b4 2963 }
a48ce6be 2964
93661e56
DM
2965 case CXt_LOOP_LIST: /* for (1,2,3) */
2966
2967 assert(OPpITER_REVERSED == 2); /* so inc becomes -1 or 1 */
2968 inc = 1 - (PL_op->op_private & OPpITER_REVERSED);
2969 ix = (cx->blk_loop.state_u.stack.ix += inc);
2970 if (UNLIKELY(inc > 0
2971 ? ix > cx->blk_oldsp
2972 : ix <= cx->blk_loop.state_u.stack.basesp)
2973 )
8a1f10dd 2974 goto retno;
93661e56
DM
2975
2976 sv = PL_stack_base[ix];
2977 av = NULL;
2978 goto loop_ary_common;
2979
2980 case CXt_LOOP_ARY: /* for (@ary) */
2981
2982 av = cx->blk_loop.state_u.ary.ary;
2983 inc = 1 - (PL_op->op_private & OPpITER_REVERSED);
2984 ix = (cx->blk_loop.state_u.ary.ix += inc);
2985 if (UNLIKELY(inc > 0
2986 ? ix > AvFILL(av)
2987 : ix < 0)
2988 )
8a1f10dd 2989 goto retno;
de080daa 2990
9d1ee8e0 2991 if (UNLIKELY(SvRMAGICAL(av))) {
a8a20bb6
DM
2992 SV * const * const svp = av_fetch(av, ix, FALSE);
2993 sv = svp ? *svp : NULL;
2994 }
2995 else {
2996 sv = AvARRAY(av)[ix];
de080daa 2997 }
ef3e5ea9 2998
93661e56
DM
2999 loop_ary_common:
3000
d39c26a6
FC
3001 if (UNLIKELY(cx->cx_type & CXp_FOR_LVREF)) {
3002 SvSetMagicSV(*itersvp, sv);
3003 break;
3004 }
3005
5d9574c1
DM
3006 if (LIKELY(sv)) {
3007 if (UNLIKELY(SvIS_FREED(sv))) {
f38aa882
DM
3008 *itersvp = NULL;
3009 Perl_croak(aTHX_ "Use of freed value in iteration");
3010 }
60779a30 3011 if (SvPADTMP(sv)) {
8e079c2a 3012 sv = newSVsv(sv);
60779a30 3013 }
8e079c2a
FC
3014 else {
3015 SvTEMP_off(sv);
3016 SvREFCNT_inc_simple_void_NN(sv);
3017 }
de080daa 3018 }
93661e56 3019 else if (av) {
199f858d 3020 sv = newSVavdefelem(av, ix, 0);
de080daa 3021 }
a600f7e6
FC
3022 else
3023 sv = &PL_sv_undef;
a0d0e21e 3024
de080daa
DM
3025 oldsv = *itersvp;
3026 *itersvp = sv;
3027 SvREFCNT_dec(oldsv);
de080daa 3028 break;
a48ce6be
DM
3029
3030 default:
3031 DIE(aTHX_ "panic: pp_iter, type=%u", CxTYPE(cx));
3032 }
8a1f10dd
DM
3033
3034 retsv = &PL_sv_yes;
3035 if (0) {
3036 retno:
3037 retsv = &PL_sv_no;
3038 }
3039 /* pp_enteriter should have pre-extended the stack */
87058c31 3040 EXTEND_SKIP(PL_stack_sp, 1);
8a1f10dd
DM
3041 *++PL_stack_sp =retsv;
3042
3043 return PL_op->op_next;
a0d0e21e
LW
3044}
3045
ef07e810
DM
3046/*
3047A description of how taint works in pattern matching and substitution.
3048
284167a5
SM
3049This is all conditional on NO_TAINT_SUPPORT not being defined. Under
3050NO_TAINT_SUPPORT, taint-related operations should become no-ops.
3051
4e19c54b 3052While the pattern is being assembled/concatenated and then compiled,
284167a5
SM
3053PL_tainted will get set (via TAINT_set) if any component of the pattern
3054is tainted, e.g. /.*$tainted/. At the end of pattern compilation,
3055the RXf_TAINTED flag is set on the pattern if PL_tainted is set (via
1738e041
DM
3056TAINT_get). It will also be set if any component of the pattern matches
3057based on locale-dependent behavior.
ef07e810 3058
0ab462a6
DM
3059When the pattern is copied, e.g. $r = qr/..../, the SV holding the ref to
3060the pattern is marked as tainted. This means that subsequent usage, such
284167a5
SM
3061as /x$r/, will set PL_tainted using TAINT_set, and thus RXf_TAINTED,
3062on the new pattern too.
ef07e810 3063
272d35c9 3064RXf_TAINTED_SEEN is used post-execution by the get magic code
ef07e810
DM
3065of $1 et al to indicate whether the returned value should be tainted.
3066It is the responsibility of the caller of the pattern (i.e. pp_match,
3067pp_subst etc) to set this flag for any other circumstances where $1 needs
3068to be tainted.
3069
3070The taint behaviour of pp_subst (and pp_substcont) is quite complex.
3071
3072There are three possible sources of taint
3073 * the source string
3074 * the pattern (both compile- and run-time, RXf_TAINTED / RXf_TAINTED_SEEN)
3075 * the replacement string (or expression under /e)
3076
3077There are four destinations of taint and they are affected by the sources
3078according to the rules below:
3079
3080 * the return value (not including /r):
3081 tainted by the source string and pattern, but only for the
3082 number-of-iterations case; boolean returns aren't tainted;
3083 * the modified string (or modified copy under /r):
3084 tainted by the source string, pattern, and replacement strings;
3085 * $1 et al:
3086 tainted by the pattern, and under 'use re "taint"', by the source
3087 string too;
3088 * PL_taint - i.e. whether subsequent code (e.g. in a /e block) is tainted:
3089 should always be unset before executing subsequent code.
3090
3091The overall action of pp_subst is:
3092
3093 * at the start, set bits in rxtainted indicating the taint status of
3094 the various sources.
3095
3096 * After each pattern execution, update the SUBST_TAINT_PAT bit in
3097 rxtainted if RXf_TAINTED_SEEN has been set, to indicate that the
3098 pattern has subsequently become tainted via locale ops.
3099
3100 * If control is being passed to pp_substcont to execute a /e block,
3101 save rxtainted in the CXt_SUBST block, for future use by
3102 pp_substcont.
3103
3104 * Whenever control is being returned to perl code (either by falling
3105 off the "end" of pp_subst/pp_substcont, or by entering a /e block),
3106 use the flag bits in rxtainted to make all the appropriate types of
0ab462a6
DM
3107 destination taint visible; e.g. set RXf_TAINTED_SEEN so that $1
3108 et al will appear tainted.
ef07e810
DM
3109
3110pp_match is just a simpler version of the above.
3111
3112*/
3113
a0d0e21e
LW
3114PP(pp_subst)
3115{
20b7effb 3116 dSP; dTARG;
eb578fdb 3117 PMOP *pm = cPMOP;
a0d0e21e 3118 PMOP *rpm = pm;
eb578fdb 3119 char *s;
a0d0e21e 3120 char *strend;
5c144d81 3121 const char *c;
a0d0e21e 3122 STRLEN clen;
3c6ef0a5
FC
3123 SSize_t iters = 0;
3124 SSize_t maxiters;
a0d0e21e 3125 bool once;
ef07e810
DM
3126 U8 rxtainted = 0; /* holds various SUBST_TAINT_* flag bits.
3127 See "how taint works" above */
a0d0e21e 3128 char *orig;
1ed74d04 3129 U8 r_flags;
eb578fdb 3130 REGEXP *rx = PM_GETRE(pm);
a0d0e21e
LW
3131 STRLEN len;
3132 int force_on_match = 0;
0bcc34c2 3133 const I32 oldsave = PL_savestack_ix;
792b2c16 3134 STRLEN slen;
26a74523 3135 bool doutf8 = FALSE; /* whether replacement is in utf8 */
db2c6cb3 3136#ifdef PERL_ANY_COW
106d9a13 3137 bool was_cow;
ed252734 3138#endif
a0714e2c 3139 SV *nsv = NULL;
b770e143 3140 /* known replacement string? */
eb578fdb 3141 SV *dstr = (pm->op_pmflags & PMf_CONST) ? POPs : NULL;
a0d0e21e 3142
f410a211
NC
3143 PERL_ASYNC_CHECK();
3144
533c011a 3145 if (PL_op->op_flags & OPf_STACKED)
a0d0e21e
LW
3146 TARG = POPs;
3147 else {
9399c607
DM
3148 if (ARGTARG)
3149 GETTARGET;
3150 else {
3151 TARG = DEFSV;
3152 }
a0d0e21e 3153 EXTEND(SP,1);
1c846c1f 3154 }
d9f424b2 3155
64534138 3156 SvGETMAGIC(TARG); /* must come before cow check */
db2c6cb3 3157#ifdef PERL_ANY_COW
106d9a13
DM
3158 /* note that a string might get converted to COW during matching */
3159 was_cow = cBOOL(SvIsCOW(TARG));
ed252734 3160#endif
d13a5d3b
TC
3161 if (!(rpm->op_pmflags & PMf_NONDESTRUCT)) {
3162#ifndef PERL_ANY_COW
3163 if (SvIsCOW(TARG))
3164 sv_force_normal_flags(TARG,0);
3165#endif
3166 if ((SvREADONLY(TARG)
3167 || ( ((SvTYPE(TARG) == SVt_PVGV && isGV_with_GP(TARG))
3168 || SvTYPE(TARG) > SVt_PVLV)
3169 && !(SvTYPE(TARG) == SVt_PVGV && SvFAKE(TARG)))))
3170 Perl_croak_no_modify();
3171 }
8ec5e241
NIS
3172 PUTBACK;
3173
6ac6605d
DM
3174 orig = SvPV_nomg(TARG, len);
3175 /* note we don't (yet) force the var into being a string; if we fail
92711104 3176 * to match, we leave as-is; on successful match however, we *will*
6ac6605d 3177 * coerce into a string, then repeat the match */
4499db73 3178 if (!SvPOKp(TARG) || SvTYPE(TARG) == SVt_PVGV || SvVOK(TARG))
a0d0e21e 3179 force_on_match = 1;
20be6587
DM
3180
3181 /* only replace once? */
3182 once = !(rpm->op_pmflags & PMf_GLOBAL);
3183
ef07e810 3184 /* See "how taint works" above */
284167a5 3185 if (TAINTING_get) {
20be6587
DM
3186 rxtainted = (
3187 (SvTAINTED(TARG) ? SUBST_TAINT_STR : 0)
284167a5 3188 | (RX_ISTAINTED(rx) ? SUBST_TAINT_PAT : 0)
20be6587
DM
3189 | ((pm->op_pmflags & PMf_RETAINT) ? SUBST_TAINT_RETAINT : 0)
3190 | ((once && !(rpm->op_pmflags & PMf_NONDESTRUCT))
3191 ? SUBST_TAINT_BOOLRET : 0));
3192 TAINT_NOT;
3193 }
a12c0f56 3194
a0d0e21e 3195 force_it:
6ac6605d
DM
3196 if (!pm || !orig)
3197 DIE(aTHX_ "panic: pp_subst, pm=%p, orig=%p", pm, orig);
a0d0e21e 3198
6ac6605d
DM
3199 strend = orig + len;
3200 slen = DO_UTF8(TARG) ? utf8_length((U8*)orig, (U8*)strend) : len;
792b2c16
JH
3201 maxiters = 2 * slen + 10; /* We can match twice at each
3202 position, once with zero-length,
3203 second time with non-zero. */
a0d0e21e 3204
794826f4
YO
3205 /* handle the empty pattern */
3206 if (!RX_PRELEN(rx) && PL_curpm && !ReANY(rx)->mother_re) {
5585e758
YO
3207 if (PL_curpm == PL_reg_curpm) {
3208 if (PL_curpm_under) {
3209 if (PL_curpm_under == PL_reg_curpm) {
3210 Perl_croak(aTHX_ "Infinite recursion via empty pattern");
3211 } else {
3212 pm = PL_curpm_under;
3213 }
3214 }
3215 } else {
3216 pm = PL_curpm;
3217 }
3218 rx = PM_GETRE(pm);
a0d0e21e 3219 }
6502e081 3220
6e240d0b 3221#ifdef PERL_SAWAMPERSAND
6502e081
DM
3222 r_flags = ( RX_NPARENS(rx)
3223 || PL_sawampersand
6502e081 3224 || (RX_EXTFLAGS(rx) & (RXf_EVAL_SEEN|RXf_PMf_KEEPCOPY))
5b0e71e9 3225 || (rpm->op_pmflags & PMf_KEEPCOPY)
6502e081
DM
3226 )
3227 ? REXEC_COPY_STR
3228 : 0;
6e240d0b
FC
3229#else
3230 r_flags = REXEC_COPY_STR;
3231#endif
7fba1cd6 3232
0395280b 3233 if (!CALLREGEXEC(rx, orig, strend, orig, 0, TARG, NULL, r_flags))
8b64c330 3234 {
5e79dfb9
DM
3235 SPAGAIN;
3236 PUSHs(rpm->op_pmflags & PMf_NONDESTRUCT ? TARG : &PL_sv_no);
3237 LEAVE_SCOPE(oldsave);
3238 RETURN;
3239 }
1754320d
FC
3240 PL_curpm = pm;
3241
71be2cbc 3242 /* known replacement string? */
f272994b 3243 if (dstr) {
8514a05a
JH
3244 /* replacement needing upgrading? */
3245 if (DO_UTF8(TARG) && !doutf8) {
db79b45b 3246 nsv = sv_newmortal();
4a176938 3247 SvSetSV(nsv, dstr);
8df0e7a2 3248 sv_utf8_upgrade(nsv);
5c144d81 3249 c = SvPV_const(nsv, clen);
4a176938
JH
3250 doutf8 = TRUE;
3251 }
3252 else {
5c144d81 3253 c = SvPV_const(dstr, clen);
4a176938 3254 doutf8 = DO_UTF8(dstr);
8514a05a 3255 }
bb933b9b
FC
3256
3257 if (SvTAINTED(dstr))
3258 rxtainted |= SUBST_TAINT_REPL;
f272994b
A
3259 }
3260 else {
6136c704 3261 c = NULL;
f272994b
A
3262 doutf8 = FALSE;
3263 }
3264
71be2cbc 3265 /* can do inplace substitution? */
ed252734 3266 if (c
db2c6cb3 3267#ifdef PERL_ANY_COW
106d9a13 3268 && !was_cow
ed252734 3269#endif
fbfb1899 3270 && (I32)clen <= RX_MINLENRET(rx)
9cefd268
FC
3271 && ( once
3272 || !(r_flags & REXEC_COPY_STR)
3273 || (!SvGMAGICAL(dstr) && !(RX_EXTFLAGS(rx) & RXf_EVAL_SEEN))
3274 )
dbc200c5 3275 && !(RX_EXTFLAGS(rx) & RXf_NO_INPLACE_SUBST)
8ca8a454
NC
3276 && (!doutf8 || SvUTF8(TARG))
3277 && !(rpm->op_pmflags & PMf_NONDESTRUCT))
8b030b38 3278 {
ec911639 3279
db2c6cb3 3280#ifdef PERL_ANY_COW
106d9a13 3281 /* string might have got converted to COW since we set was_cow */
ed252734 3282 if (SvIsCOW(TARG)) {
f7a8268c 3283 if (!force_on_match)
ed252734 3284 goto have_a_cow;
f7a8268c 3285 assert(SvVOK(TARG));
ed252734
NC
3286 }
3287#endif
71be2cbc 3288 if (force_on_match) {
6ac6605d
DM
3289 /* redo the first match, this time with the orig var
3290 * forced into being a string */
71be2cbc 3291 force_on_match = 0;
6ac6605d 3292 orig = SvPV_force_nomg(TARG, len);
71be2cbc
PP
3293 goto force_it;
3294 }
39b40493 3295
71be2cbc 3296 if (once) {
c67ab8f2 3297 char *d, *m;
20be6587
DM
3298 if (RX_MATCH_TAINTED(rx)) /* run time pattern taint, eg locale */
3299 rxtainted |= SUBST_TAINT_PAT;
07bc277f
NC
3300 m = orig + RX_OFFS(rx)[0].start;
3301 d = orig + RX_OFFS(rx)[0].end;
71be2cbc
PP
3302 s = orig;
3303 if (m - s > strend - d) { /* faster to shorten from end */
2ec7214c 3304 I32 i;
71be2cbc
PP
3305 if (clen) {
3306 Copy(c, m, clen, char);
3307 m += clen;
a0d0e21e 3308 }
71be2cbc
PP
3309 i = strend - d;
3310 if (i > 0) {
3311 Move(d, m, i, char);
3312 m += i;
a0d0e21e 3313 }
71be2cbc
PP
3314 *m = '\0';
3315 SvCUR_set(TARG, m - s);
3316 }
2ec7214c
DM
3317 else { /* faster from front */
3318 I32 i = m - s;
71be2cbc 3319 d -= clen;
2ec7214c
DM
3320 if (i > 0)
3321 Move(s, d - i, i, char);
71be2cbc 3322 sv_chop(TARG, d-i);
71be2cbc 3323 if (clen)
c947cd8d 3324 Copy(c, d, clen, char);
71be2cbc 3325 }
8ec5e241 3326 SPAGAIN;
8ca8a454 3327 PUSHs(&PL_sv_yes);
71be2cbc
PP
3328 }
3329 else {
c67ab8f2 3330 char *d, *m;
0395280b 3331 d = s = RX_OFFS(rx)[0].start + orig;
71be2cbc 3332 do {
2b25edcf 3333 I32 i;
5d9574c1 3334 if (UNLIKELY(iters++ > maxiters))
cea2e8a9 3335 DIE(aTHX_ "Substitution loop");
5d9574c1 3336 if (UNLIKELY(RX_MATCH_TAINTED(rx))) /* run time pattern taint, eg locale */
20be6587 3337 rxtainted |= SUBST_TAINT_PAT;
07bc277f 3338 m = RX_OFFS(rx)[0].start + orig;
155aba94 3339 if ((i = m - s)) {
71be2cbc
PP
3340 if (s != d)
3341 Move(s, d, i, char);
3342 d += i;
a0d0e21e 3343 }
71be2cbc
PP
3344 if (clen) {
3345 Copy(c, d, clen, char);
3346 d += clen;
3347 }
07bc277f 3348 s = RX_OFFS(rx)[0].end + orig;
7ce41e5c
FC
3349 } while (CALLREGEXEC(rx, s, strend, orig,
3350 s == m, /* don't match same null twice */
f722798b 3351 TARG, NULL,
d5e7783a 3352 REXEC_NOT_FIRST|REXEC_IGNOREPOS|REXEC_FAIL_ON_UNDERFLOW));
71be2cbc 3353 if (s != d) {
2b25edcf 3354 I32 i = strend - s;
aa07b2f6 3355 SvCUR_set(TARG, d - SvPVX_const(TARG) + i);
71be2cbc 3356 Move(s, d, i+1, char); /* include the NUL */
a0d0e21e 3357 }
8ec5e241 3358 SPAGAIN;
3c6ef0a5 3359 mPUSHi(iters);
a0d0e21e
LW
3360 }
3361 }
ff6e92e8 3362 else {
1754320d 3363 bool first;
c67ab8f2 3364 char *m;
1754320d 3365 SV *repl;
a0d0e21e 3366 if (force_on_match) {
6ac6605d
DM
3367 /* redo the first match, this time with the orig var
3368 * forced into being a string */
a0d0e21e 3369 force_on_match = 0;
0c1438a1
NC
3370 if (rpm->op_pmflags & PMf_NONDESTRUCT) {
3371 /* I feel that it should be possible to avoid this mortal copy
3372 given that the code below copies into a new destination.
3373 However, I suspect it isn't worth the complexity of
3374 unravelling the C<goto force_it> for the small number of
3375 cases where it would be viable to drop into the copy code. */
3376 TARG = sv_2mortal(newSVsv(TARG));
3377 }
6ac6605d 3378 orig = SvPV_force_nomg(TARG, len);
a0d0e21e
LW
3379 goto force_it;
3380 }
db2c6cb3 3381#ifdef PERL_ANY_COW
ed252734
NC
3382 have_a_cow:
3383#endif
20be6587
DM
3384 if (RX_MATCH_TAINTED(rx)) /* run time pattern taint, eg locale */
3385 rxtainted |= SUBST_TAINT_PAT;
1754320d 3386 repl = dstr;
0395280b
DM
3387 s = RX_OFFS(rx)[0].start + orig;
3388 dstr = newSVpvn_flags(orig, s-orig,
3389 SVs_TEMP | (DO_UTF8(TARG) ? SVf_UTF8 : 0));
a0d0e21e 3390 if (!c) {
eb578fdb 3391 PERL_CONTEXT *cx;
8ec5e241 3392 SPAGAIN;
0395280b 3393 m = orig;
20be6587
DM
3394 /* note that a whole bunch of local vars are saved here for
3395 * use by pp_substcont: here's a list of them in case you're
3396 * searching for places in this sub that uses a particular var:
3397 * iters maxiters r_flags oldsave rxtainted orig dstr targ
3398 * s m strend rx once */
490576d1 3399 CX_PUSHSUBST(cx);
20e98b0f 3400 RETURNOP(cPMOP->op_pmreplrootu.op_pmreplroot);
a0d0e21e 3401 }
1754320d 3402 first = TRUE;
a0d0e21e 3403 do {
5d9574c1 3404 if (UNLIKELY(iters++ > maxiters))
cea2e8a9 3405 DIE(aTHX_ "Substitution loop");
5d9574c1 3406 if (UNLIKELY(RX_MATCH_TAINTED(rx)))
20be6587 3407 rxtainted |= SUBST_TAINT_PAT;
07bc277f 3408 if (RX_MATCH_COPIED(rx) && RX_SUBBEG(rx) != orig) {
c67ab8f2
DM
3409 char *old_s = s;
3410 char *old_orig = orig;
6502e081 3411 assert(RX_SUBOFFSET(rx) == 0);
c67ab8f2 3412
07bc277f 3413 orig = RX_SUBBEG(rx);
c67ab8f2
DM
3414 s = orig + (old_s - old_orig);
3415 strend = s + (strend - old_s);
a0d0e21e 3416 }
07bc277f 3417 m = RX_OFFS(rx)[0].start + orig;
64534138 3418 sv_catpvn_nomg_maybeutf8(dstr, s, m - s, DO_UTF8(TARG));
07bc277f 3419 s = RX_OFFS(rx)[0].end + orig;
1754320d
FC
3420 if (first) {
3421 /* replacement already stringified */
3422 if (clen)
64534138 3423 sv_catpvn_nomg_maybeutf8(dstr, c, clen, doutf8);
1754320d
FC
3424 first = FALSE;
3425 }
3426 else {
8df0e7a2 3427 sv_catsv(dstr, repl);
5d9574c1 3428 if (UNLIKELY(SvTAINTED(repl)))
bb933b9b 3429 rxtainted |= SUBST_TAINT_REPL;
1754320d 3430 }
a0d0e21e
LW
3431 if (once)
3432 break;
ff27773b
KW
3433 } while (CALLREGEXEC(rx, s, strend, orig,
3434 s == m, /* Yields minend of 0 or 1 */
d5e7783a
DM
3435 TARG, NULL,
3436 REXEC_NOT_FIRST|REXEC_IGNOREPOS|REXEC_FAIL_ON_UNDERFLOW));
aba224f7 3437 assert(strend >= s);
64534138 3438 sv_catpvn_nomg_maybeutf8(dstr, s, strend - s, DO_UTF8(TARG));
748a9306 3439
8ca8a454
NC
3440 if (rpm->op_pmflags & PMf_NONDESTRUCT) {
3441 /* From here on down we're using the copy, and leaving the original
3442 untouched. */
3443 TARG = dstr;
3444 SPAGAIN;
3445 PUSHs(dstr);
3446 } else {
db2c6cb3 3447#ifdef PERL_ANY_COW
8ca8a454
NC
3448 /* The match may make the string COW. If so, brilliant, because
3449 that's just saved us one malloc, copy and free - the regexp has
3450 donated the old buffer, and we malloc an entirely new one, rather
3451 than the regexp malloc()ing a buffer and copying our original,
3452 only for us to throw it away here during the substitution. */
3453 if (SvIsCOW(TARG)) {
3454 sv_force_normal_flags(TARG, SV_COW_DROP_PV);
3455 } else
ed252734 3456#endif
8ca8a454
NC
3457 {
3458 SvPV_free(TARG);
3459 }
3460 SvPV_set(TARG, SvPVX(dstr));
3461 SvCUR_set(TARG, SvCUR(dstr));
3462 SvLEN_set(TARG, SvLEN(dstr));
64534138 3463 SvFLAGS(TARG) |= SvUTF8(dstr);
8ca8a454 3464 SvPV_set(dstr, NULL);
748a9306 3465
8ca8a454 3466 SPAGAIN;
3c6ef0a5 3467 mPUSHi(iters);
8ca8a454
NC
3468 }
3469 }
3470
3471 if (!(rpm->op_pmflags & PMf_NONDESTRUCT)) {
3472 (void)SvPOK_only_UTF8(TARG);
a0d0e21e 3473 }
20be6587 3474
ef07e810 3475 /* See "how taint works" above */
284167a5 3476 if (TAINTING_get) {
20be6587
DM
3477 if ((rxtainted & SUBST_TAINT_PAT) ||
3478 ((rxtainted & (SUBST_TAINT_STR|SUBST_TAINT_RETAINT)) ==
3479 (SUBST_TAINT_STR|SUBST_TAINT_RETAINT))
3480 )
3481 (RX_MATCH_TAINTED_on(rx)); /* taint $1 et al */
3482
3483 if (!(rxtainted & SUBST_TAINT_BOOLRET)
3484 && (rxtainted & (SUBST_TAINT_STR|SUBST_TAINT_PAT))
3485 )
3486 SvTAINTED_on(TOPs); /* taint return value */
3487 else
3488 SvTAINTED_off(TOPs); /* may have got tainted earlier */
3489
3490 /* needed for mg_set below */
284167a5
SM
3491 TAINT_set(
3492 cBOOL(rxtainted & (SUBST_TAINT_STR|SUBST_TAINT_PAT|SUBST_TAINT_REPL))
3493 );
20be6587
DM
3494 SvTAINT(TARG);
3495 }
3496 SvSETMAGIC(TARG); /* PL_tainted must be correctly set for this mg_set */
3497 TAINT_NOT;
f1a76097
DM
3498 LEAVE_SCOPE(oldsave);
3499 RETURN;
a0d0e21e
LW
3500}
3501
3502PP(pp_grepwhile)
3503{
20b7effb 3504 dSP;
a0d0e21e
LW
3505
3506 if (SvTRUEx(POPs))
3280af22
NIS
3507 PL_stack_base[PL_markstack_ptr[-1]++] = PL_stack_base[*PL_markstack_ptr];
3508 ++*PL_markstack_ptr;
b2a2a901 3509 FREETMPS;
d343c3ef 3510 LEAVE_with_name("grep_item"); /* exit inner scope */
a0d0e21e
LW
3511
3512 /* All done yet? */
5d9574c1 3513 if (UNLIKELY(PL_stack_base + *PL_markstack_ptr > SP)) {
a0d0e21e 3514 I32 items;
1c23e2bd 3515 const U8 gimme = GIMME_V;
a0d0e21e 3516
d343c3ef 3517 LEAVE_with_name("grep"); /* exit outer scope */
a0d0e21e 3518 (void)POPMARK; /* pop src */
3280af22 3519 items = --*PL_markstack_ptr - PL_markstack_ptr[-1];
a0d0e21e 3520 (void)POPMARK; /* pop dst */
3280af22 3521 SP = PL_stack_base + POPMARK; /* pop original mark */
54310121 3522 if (gimme == G_SCALAR) {
7cc47870
RGS
3523 dTARGET;
3524 XPUSHi(items);
a0d0e21e 3525 }
54310121
PP
3526 else if (gimme == G_ARRAY)
3527 SP += items;
a0d0e21e
LW
3528 RETURN;
3529 }
3530 else {
3531 SV *src;
3532
d343c3ef 3533 ENTER_with_name("grep_item"); /* enter inner scope */
1d7c1841 3534 SAVEVPTR(PL_curpm);
a0d0e21e 3535
6cae08a8 3536 src = PL_stack_base[TOPMARK];
60779a30 3537 if (SvPADTMP(src)) {
6cae08a8 3538 src = PL_stack_base[TOPMARK] = sv_mortalcopy(src);
a0ed822e
FC
3539 PL_tmps_floor++;
3540 }
a0d0e21e 3541 SvTEMP_off(src);
ffd49c98 3542 DEFSV_set(src);
a0d0e21e
LW
3543
3544 RETURNOP(cLOGOP->op_other);
3545 }
3546}
3547
799da9d7 3548/* leave_adjust_stacks():
f7a874b8 3549 *
e02ce34b
DM
3550 * Process a scope's return args (in the range from_sp+1 .. PL_stack_sp),
3551 * positioning them at to_sp+1 onwards, and do the equivalent of a
3552 * FREEMPS and TAINT_NOT.
3553 *
f7a874b8
DM
3554 * Not intended to be called in void context.
3555 *
799da9d7
DM
3556 * When leaving a sub, eval, do{} or other scope, the things that need
3557 * doing to process the return args are:
f7a874b8 3558 * * in scalar context, only return the last arg (or PL_sv_undef if none);
799da9d7
DM
3559 * * for the types of return that return copies of their args (such
3560 * as rvalue sub return), make a mortal copy of every return arg,
3561 * except where we can optimise the copy away without it being
3562 * semantically visible;
3563 * * make sure that the arg isn't prematurely freed; in the case of an
3564 * arg not copied, this may involve mortalising it. For example, in
f7a874b8
DM
3565 * C<sub f { my $x = ...; $x }>, $x would be freed when we do
3566 * CX_LEAVE_SCOPE(cx) unless it's protected or copied.
3567 *
799da9d7
DM
3568 * What condition to use when deciding whether to pass the arg through
3569 * or make a copy, is determined by the 'pass' arg; its valid values are:
3570 * 0: rvalue sub/eval exit
3571 * 1: other rvalue scope exit
3572 * 2: :lvalue sub exit in rvalue context
3573 * 3: :lvalue sub exit in lvalue context and other lvalue scope exits
3574 *
f7a874b8 3575 * There is a big issue with doing a FREETMPS. We would like to free any
799da9d7 3576 * temps created by the last statement which the sub executed, rather than
f7a874b8
DM
3577 * leaving them for the caller. In a situation where a sub call isn't
3578 * soon followed by a nextstate (e.g. nested recursive calls, a la
3579 * fibonacci()), temps can accumulate, causing memory and performance
3580 * issues.
3581 *
3582 * On the other hand, we don't want to free any TEMPs which are keeping
799da9d7
DM
3583 * alive any return args that we skipped copying; nor do we wish to undo
3584 * any mortalising done here.
f7a874b8
DM
3585 *
3586 * The solution is to split the temps stack frame into two, with a cut
3587 * point delineating the two halves. We arrange that by the end of this
3588 * function, all the temps stack frame entries we wish to keep are in the
799da9d7 3589 * range PL_tmps_floor+1.. tmps_base-1, while the ones to free now are in
f7a874b8
DM
3590 * the range tmps_base .. PL_tmps_ix. During the course of this
3591 * function, tmps_base starts off as PL_tmps_floor+1, then increases
3592 * whenever we find or create a temp that we know should be kept. In
3593 * general the stuff above tmps_base is undecided until we reach the end,
3594 * and we may need a sort stage for that.
3595 *
3596 * To determine whether a TEMP is keeping a return arg alive, every
3597 * arg that is kept rather than copied and which has the SvTEMP flag
3598 * set, has the flag temporarily unset, to mark it. At the end we scan
799da9d7 3599 * the temps stack frame above the cut for entries without SvTEMP and
f7a874b8 3600 * keep them, while turning SvTEMP on again. Note that if we die before
799da9d7 3601 * the SvTEMPs flags are set again, its safe: at worst, subsequent use of
f7a874b8
DM
3602 * those SVs may be slightly less efficient.
3603 *
3604 * In practice various optimisations for some common cases mean we can
3605 * avoid most of the scanning and swapping about with the temps stack.
3606 */
3607
799da9d7 3608void
1c23e2bd 3609Perl_leave_adjust_stacks(pTHX_ SV **from_sp, SV **to_sp, U8 gimme, int pass)
a0d0e21e 3610{
263e0548 3611 dVAR;
20b7effb 3612 dSP;
f7a874b8
DM
3613 SSize_t tmps_base; /* lowest index into tmps stack that needs freeing now */
3614 SSize_t nargs;
3615
799da9d7
DM
3616 PERL_ARGS_ASSERT_LEAVE_ADJUST_STACKS;
3617
f7a874b8
DM
3618 TAINT_NOT;
3619
3620 if (gimme == G_ARRAY) {
e02ce34b
DM
3621 nargs = SP - from_sp;
3622 from_sp++;
f7a874b8
DM
3623 }
3624 else {
3625 assert(gimme == G_SCALAR);
e02ce34b 3626 if (UNLIKELY(from_sp >= SP)) {
f7a874b8 3627 /* no return args */
e02ce34b 3628 assert(from_sp == SP);
f7a874b8
DM
3629 EXTEND(SP, 1);
3630 *++SP = &PL_sv_undef;
e02ce34b 3631 to_sp = SP;
f7a874b8