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add S_padhv_rv2hv_common() function
[perl5.git] / pp_hot.c
CommitLineData
a0d0e21e
LW
1/* pp_hot.c
2 *
1129b882
NC
3 * Copyright (C) 1991, 1992, 1993, 1994, 1995, 1996, 1997, 1998, 1999, 2000,
4 * 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008 by Larry Wall and others
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LW
5 *
6 * You may distribute under the terms of either the GNU General Public
7 * License or the Artistic License, as specified in the README file.
8 *
9 */
10
11/*
12 * Then he heard Merry change the note, and up went the Horn-cry of Buckland,
13 * shaking the air.
14 *
4ac71550
TC
15 * Awake! Awake! Fear, Fire, Foes! Awake!
16 * Fire, Foes! Awake!
17 *
18 * [p.1007 of _The Lord of the Rings_, VI/viii: "The Scouring of the Shire"]
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LW
19 */
20
166f8a29
DM
21/* This file contains 'hot' pp ("push/pop") functions that
22 * execute the opcodes that make up a perl program. A typical pp function
23 * expects to find its arguments on the stack, and usually pushes its
24 * results onto the stack, hence the 'pp' terminology. Each OP structure
25 * contains a pointer to the relevant pp_foo() function.
26 *
27 * By 'hot', we mean common ops whose execution speed is critical.
28 * By gathering them together into a single file, we encourage
29 * CPU cache hits on hot code. Also it could be taken as a warning not to
30 * change any code in this file unless you're sure it won't affect
31 * performance.
32 */
33
a0d0e21e 34#include "EXTERN.h"
864dbfa3 35#define PERL_IN_PP_HOT_C
a0d0e21e
LW
36#include "perl.h"
37
38/* Hot code. */
39
40PP(pp_const)
41{
39644a26 42 dSP;
996c9baa 43 XPUSHs(cSVOP_sv);
a0d0e21e
LW
44 RETURN;
45}
46
47PP(pp_nextstate)
48{
533c011a 49 PL_curcop = (COP*)PL_op;
a0d0e21e 50 TAINT_NOT; /* Each statement is presumed innocent */
4ebe6e95 51 PL_stack_sp = PL_stack_base + CX_CUR()->blk_oldsp;
a0d0e21e 52 FREETMPS;
f410a211 53 PERL_ASYNC_CHECK();
a0d0e21e
LW
54 return NORMAL;
55}
56
57PP(pp_gvsv)
58{
39644a26 59 dSP;
924508f0 60 EXTEND(SP,1);
5d9574c1 61 if (UNLIKELY(PL_op->op_private & OPpLVAL_INTRO))
1d7c1841 62 PUSHs(save_scalar(cGVOP_gv));
a0d0e21e 63 else
c69033f2 64 PUSHs(GvSVn(cGVOP_gv));
a0d0e21e
LW
65 RETURN;
66}
67
b1c05ba5
DM
68
69/* also used for: pp_lineseq() pp_regcmaybe() pp_scalar() pp_scope() */
70
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;
f4c975aa
DM
234 SV *sv;
235
f410a211 236 PERL_ASYNC_CHECK();
f4c975aa
DM
237 sv = POPs;
238 RETURNOP(SvTRUE_NN(sv) ? cLOGOP->op_other : 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 435 dSP;
12dc5f94
DM
436 /* pp_coreargs pushes a NULL to indicate no args passed to
437 * CORE::readline() */
30901a8a
FC
438 if (TOPs) {
439 SvGETMAGIC(TOPs);
fc99edcf 440 tryAMAGICunTARGETlist(iter_amg, 0);
30901a8a
FC
441 PL_last_in_gv = MUTABLE_GV(*PL_stack_sp--);
442 }
443 else PL_last_in_gv = PL_argvgv, PL_stack_sp--;
6e592b3a
BM
444 if (!isGV_with_GP(PL_last_in_gv)) {
445 if (SvROK(PL_last_in_gv) && isGV_with_GP(SvRV(PL_last_in_gv)))
159b6efe 446 PL_last_in_gv = MUTABLE_GV(SvRV(PL_last_in_gv));
8efb3254 447 else {
f5284f61 448 dSP;
ad64d0ec 449 XPUSHs(MUTABLE_SV(PL_last_in_gv));
f5284f61 450 PUTBACK;
897d3989 451 Perl_pp_rv2gv(aTHX);
159b6efe 452 PL_last_in_gv = MUTABLE_GV(*PL_stack_sp--);
84ee769f
FC
453 if (PL_last_in_gv == (GV *)&PL_sv_undef)
454 PL_last_in_gv = NULL;
455 else
456 assert(isGV_with_GP(PL_last_in_gv));
f5284f61
IZ
457 }
458 }
a0d0e21e
LW
459 return do_readline();
460}
461
462PP(pp_eq)
463{
20b7effb 464 dSP;
33efebe6
DM
465 SV *left, *right;
466
a42d0242 467 tryAMAGICbin_MG(eq_amg, AMGf_set|AMGf_numeric);
33efebe6
DM
468 right = POPs;
469 left = TOPs;
470 SETs(boolSV(
471 (SvIOK_notUV(left) && SvIOK_notUV(right))
472 ? (SvIVX(left) == SvIVX(right))
473 : ( do_ncmp(left, right) == 0)
474 ));
475 RETURN;
a0d0e21e
LW
476}
477
b1c05ba5 478
4c2c3128 479/* also used for: pp_i_preinc() */
b1c05ba5 480
a0d0e21e
LW
481PP(pp_preinc)
482{
4c2c3128
DM
483 SV *sv = *PL_stack_sp;
484
485 if (LIKELY(((sv->sv_flags &
486 (SVf_THINKFIRST|SVs_GMG|SVf_IVisUV|
487 SVf_IOK|SVf_NOK|SVf_POK|SVp_NOK|SVp_POK|SVf_ROK))
488 == SVf_IOK))
489 && SvIVX(sv) != IV_MAX)
490 {
491 SvIV_set(sv, SvIVX(sv) + 1);
492 }
493 else /* Do all the PERL_PRESERVE_IVUV and hard cases in sv_inc */
494 sv_inc(sv);
495 SvSETMAGIC(sv);
496 return NORMAL;
497}
498
499
500/* also used for: pp_i_predec() */
501
502PP(pp_predec)
503{
504 SV *sv = *PL_stack_sp;
505
506 if (LIKELY(((sv->sv_flags &
507 (SVf_THINKFIRST|SVs_GMG|SVf_IVisUV|
508 SVf_IOK|SVf_NOK|SVf_POK|SVp_NOK|SVp_POK|SVf_ROK))
509 == SVf_IOK))
510 && SvIVX(sv) != IV_MIN)
55497cff 511 {
4c2c3128 512 SvIV_set(sv, SvIVX(sv) - 1);
748a9306 513 }
4c2c3128
DM
514 else /* Do all the PERL_PRESERVE_IVUV and hard cases in sv_dec */
515 sv_dec(sv);
516 SvSETMAGIC(sv);
a0d0e21e
LW
517 return NORMAL;
518}
519
b1c05ba5
DM
520
521/* also used for: pp_orassign() */
522
a0d0e21e
LW
523PP(pp_or)
524{
20b7effb 525 dSP;
f4c975aa 526 SV *sv;
f410a211 527 PERL_ASYNC_CHECK();
f4c975aa
DM
528 sv = TOPs;
529 if (SvTRUE_NN(sv))
a0d0e21e
LW
530 RETURN;
531 else {
c960fc3b
SP
532 if (PL_op->op_type == OP_OR)
533 --SP;
a0d0e21e
LW
534 RETURNOP(cLOGOP->op_other);
535 }
536}
537
b1c05ba5
DM
538
539/* also used for: pp_dor() pp_dorassign() */
540
25a55bd7 541PP(pp_defined)
c963b151 542{
20b7effb 543 dSP;
eb578fdb 544 SV* sv;
6136c704 545 bool defined;
25a55bd7 546 const int op_type = PL_op->op_type;
ea5195b7 547 const bool is_dor = (op_type == OP_DOR || op_type == OP_DORASSIGN);
c963b151 548
6136c704 549 if (is_dor) {
f410a211 550 PERL_ASYNC_CHECK();
25a55bd7 551 sv = TOPs;
5d9574c1 552 if (UNLIKELY(!sv || !SvANY(sv))) {
2bd49cfc
NC
553 if (op_type == OP_DOR)
554 --SP;
25a55bd7
SP
555 RETURNOP(cLOGOP->op_other);
556 }
b7c44293
RGS
557 }
558 else {
559 /* OP_DEFINED */
25a55bd7 560 sv = POPs;
5d9574c1 561 if (UNLIKELY(!sv || !SvANY(sv)))
25a55bd7 562 RETPUSHNO;
b7c44293 563 }
25a55bd7 564
6136c704 565 defined = FALSE;
c963b151
BD
566 switch (SvTYPE(sv)) {
567 case SVt_PVAV:
568 if (AvMAX(sv) >= 0 || SvGMAGICAL(sv) || (SvRMAGICAL(sv) && mg_find(sv, PERL_MAGIC_tied)))
25a55bd7 569 defined = TRUE;
c963b151
BD
570 break;
571 case SVt_PVHV:
572 if (HvARRAY(sv) || SvGMAGICAL(sv) || (SvRMAGICAL(sv) && mg_find(sv, PERL_MAGIC_tied)))
25a55bd7 573 defined = TRUE;
c963b151
BD
574 break;
575 case SVt_PVCV:
576 if (CvROOT(sv) || CvXSUB(sv))
25a55bd7 577 defined = TRUE;
c963b151
BD
578 break;
579 default:
5b295bef 580 SvGETMAGIC(sv);
c963b151 581 if (SvOK(sv))
25a55bd7 582 defined = TRUE;
6136c704 583 break;
c963b151 584 }
6136c704
AL
585
586 if (is_dor) {
c960fc3b
SP
587 if(defined)
588 RETURN;
589 if(op_type == OP_DOR)
590 --SP;
25a55bd7 591 RETURNOP(cLOGOP->op_other);
25a55bd7 592 }
d9aa96a4
SP
593 /* assuming OP_DEFINED */
594 if(defined)
595 RETPUSHYES;
596 RETPUSHNO;
c963b151
BD
597}
598
230ee21f
DM
599
600
a0d0e21e
LW
601PP(pp_add)
602{
20b7effb 603 dSP; dATARGET; bool useleft; SV *svl, *svr;
230ee21f 604
6f1401dc
DM
605 tryAMAGICbin_MG(add_amg, AMGf_assign|AMGf_numeric);
606 svr = TOPs;
607 svl = TOPm1s;
608
28e5dec8 609#ifdef PERL_PRESERVE_IVUV
230ee21f
DM
610
611 /* special-case some simple common cases */
612 if (!((svl->sv_flags|svr->sv_flags) & (SVf_IVisUV|SVs_GMG))) {
613 IV il, ir;
614 U32 flags = (svl->sv_flags & svr->sv_flags);
615 if (flags & SVf_IOK) {
616 /* both args are simple IVs */
617 UV topl, topr;
618 il = SvIVX(svl);
619 ir = SvIVX(svr);
620 do_iv:
621 topl = ((UV)il) >> (UVSIZE * 8 - 2);
622 topr = ((UV)ir) >> (UVSIZE * 8 - 2);
623
624 /* if both are in a range that can't under/overflow, do a
625 * simple integer add: if the top of both numbers
626 * are 00 or 11, then it's safe */
627 if (!( ((topl+1) | (topr+1)) & 2)) {
628 SP--;
629 TARGi(il + ir, 0); /* args not GMG, so can't be tainted */
630 SETs(TARG);
631 RETURN;
632 }
633 goto generic;
634 }
635 else if (flags & SVf_NOK) {
636 /* both args are NVs */
637 NV nl = SvNVX(svl);
638 NV nr = SvNVX(svr);
639
3336af0b
DD
640 if (
641#if defined(NAN_COMPARE_BROKEN) && defined(Perl_isnan)
642 !Perl_isnan(nl) && nl == (NV)(il = (IV)nl)
643 && !Perl_isnan(nr) && nr == (NV)(ir = (IV)nr)
644#else
645 nl == (NV)(il = (IV)nl) && nr == (NV)(ir = (IV)nr)
646#endif
647 )
230ee21f
DM
648 /* nothing was lost by converting to IVs */
649 goto do_iv;
650 SP--;
651 TARGn(nl + nr, 0); /* args not GMG, so can't be tainted */
652 SETs(TARG);
653 RETURN;
654 }
655 }
656
657 generic:
658
659 useleft = USE_LEFT(svl);
28e5dec8
JH
660 /* We must see if we can perform the addition with integers if possible,
661 as the integer code detects overflow while the NV code doesn't.
662 If either argument hasn't had a numeric conversion yet attempt to get
663 the IV. It's important to do this now, rather than just assuming that
664 it's not IOK as a PV of "9223372036854775806" may not take well to NV
665 addition, and an SV which is NOK, NV=6.0 ought to be coerced to
666 integer in case the second argument is IV=9223372036854775806
667 We can (now) rely on sv_2iv to do the right thing, only setting the
668 public IOK flag if the value in the NV (or PV) slot is truly integer.
669
670 A side effect is that this also aggressively prefers integer maths over
7dca457a
NC
671 fp maths for integer values.
672
a00b5bd3 673 How to detect overflow?
7dca457a
NC
674
675 C 99 section 6.2.6.1 says
676
677 The range of nonnegative values of a signed integer type is a subrange
678 of the corresponding unsigned integer type, and the representation of
679 the same value in each type is the same. A computation involving
680 unsigned operands can never overflow, because a result that cannot be
681 represented by the resulting unsigned integer type is reduced modulo
682 the number that is one greater than the largest value that can be
683 represented by the resulting type.
684
685 (the 9th paragraph)
686
687 which I read as "unsigned ints wrap."
688
689 signed integer overflow seems to be classed as "exception condition"
690
691 If an exceptional condition occurs during the evaluation of an
692 expression (that is, if the result is not mathematically defined or not
693 in the range of representable values for its type), the behavior is
694 undefined.
695
696 (6.5, the 5th paragraph)
697
698 I had assumed that on 2s complement machines signed arithmetic would
699 wrap, hence coded pp_add and pp_subtract on the assumption that
700 everything perl builds on would be happy. After much wailing and
701 gnashing of teeth it would seem that irix64 knows its ANSI spec well,
702 knows that it doesn't need to, and doesn't. Bah. Anyway, the all-
703 unsigned code below is actually shorter than the old code. :-)
704 */
705
01f91bf2 706 if (SvIV_please_nomg(svr)) {
28e5dec8
JH
707 /* Unless the left argument is integer in range we are going to have to
708 use NV maths. Hence only attempt to coerce the right argument if
709 we know the left is integer. */
eb578fdb 710 UV auv = 0;
9c5ffd7c 711 bool auvok = FALSE;
7dca457a
NC
712 bool a_valid = 0;
713
28e5dec8 714 if (!useleft) {
7dca457a
NC
715 auv = 0;
716 a_valid = auvok = 1;
717 /* left operand is undef, treat as zero. + 0 is identity,
718 Could SETi or SETu right now, but space optimise by not adding
719 lots of code to speed up what is probably a rarish case. */
720 } else {
721 /* Left operand is defined, so is it IV? */
01f91bf2 722 if (SvIV_please_nomg(svl)) {
800401ee
JH
723 if ((auvok = SvUOK(svl)))
724 auv = SvUVX(svl);
7dca457a 725 else {
eb578fdb 726 const IV aiv = SvIVX(svl);
7dca457a
NC
727 if (aiv >= 0) {
728 auv = aiv;
729 auvok = 1; /* Now acting as a sign flag. */
53e2bfb7
DM
730 } else {
731 auv = (aiv == IV_MIN) ? (UV)aiv : (UV)(-aiv);
7dca457a
NC
732 }
733 }
734 a_valid = 1;
28e5dec8
JH
735 }
736 }
7dca457a
NC
737 if (a_valid) {
738 bool result_good = 0;
739 UV result;
eb578fdb 740 UV buv;
800401ee 741 bool buvok = SvUOK(svr);
a00b5bd3 742
7dca457a 743 if (buvok)
800401ee 744 buv = SvUVX(svr);
7dca457a 745 else {
eb578fdb 746 const IV biv = SvIVX(svr);
7dca457a
NC
747 if (biv >= 0) {
748 buv = biv;
749 buvok = 1;
750 } else
53e2bfb7 751 buv = (biv == IV_MIN) ? (UV)biv : (UV)(-biv);
7dca457a
NC
752 }
753 /* ?uvok if value is >= 0. basically, flagged as UV if it's +ve,
602f51c4 754 else "IV" now, independent of how it came in.
7dca457a
NC
755 if a, b represents positive, A, B negative, a maps to -A etc
756 a + b => (a + b)
757 A + b => -(a - b)
758 a + B => (a - b)
759 A + B => -(a + b)
760 all UV maths. negate result if A negative.
761 add if signs same, subtract if signs differ. */
762
763 if (auvok ^ buvok) {
764 /* Signs differ. */
765 if (auv >= buv) {
766 result = auv - buv;
767 /* Must get smaller */
768 if (result <= auv)
769 result_good = 1;
770 } else {
771 result = buv - auv;
772 if (result <= buv) {
773 /* result really should be -(auv-buv). as its negation
774 of true value, need to swap our result flag */
775 auvok = !auvok;
776 result_good = 1;
28e5dec8
JH
777 }
778 }
7dca457a
NC
779 } else {
780 /* Signs same */
781 result = auv + buv;
782 if (result >= auv)
783 result_good = 1;
784 }
785 if (result_good) {
786 SP--;
787 if (auvok)
28e5dec8 788 SETu( result );
7dca457a
NC
789 else {
790 /* Negate result */
791 if (result <= (UV)IV_MIN)
53e2bfb7
DM
792 SETi(result == (UV)IV_MIN
793 ? IV_MIN : -(IV)result);
7dca457a
NC
794 else {
795 /* result valid, but out of range for IV. */
796 SETn( -(NV)result );
28e5dec8
JH
797 }
798 }
7dca457a
NC
799 RETURN;
800 } /* Overflow, drop through to NVs. */
28e5dec8
JH
801 }
802 }
230ee21f
DM
803
804#else
805 useleft = USE_LEFT(svl);
28e5dec8 806#endif
230ee21f 807
a0d0e21e 808 {
6f1401dc 809 NV value = SvNV_nomg(svr);
4efa5a16 810 (void)POPs;
28e5dec8
JH
811 if (!useleft) {
812 /* left operand is undef, treat as zero. + 0.0 is identity. */
813 SETn(value);
814 RETURN;
815 }
6f1401dc 816 SETn( value + SvNV_nomg(svl) );
28e5dec8 817 RETURN;
a0d0e21e
LW
818 }
819}
820
b1c05ba5
DM
821
822/* also used for: pp_aelemfast_lex() */
823
a0d0e21e
LW
824PP(pp_aelemfast)
825{
20b7effb 826 dSP;
93bad3fd 827 AV * const av = PL_op->op_type == OP_AELEMFAST_LEX
8f878375 828 ? MUTABLE_AV(PAD_SV(PL_op->op_targ)) : GvAVn(cGVOP_gv);
a3b680e6 829 const U32 lval = PL_op->op_flags & OPf_MOD;
7e169e84
DM
830 const I8 key = (I8)PL_op->op_private;
831 SV** svp;
832 SV *sv;
833
834 assert(SvTYPE(av) == SVt_PVAV);
835
f4484b87
DM
836 EXTEND(SP, 1);
837
7e169e84
DM
838 /* inlined av_fetch() for simple cases ... */
839 if (!SvRMAGICAL(av) && key >= 0 && key <= AvFILLp(av)) {
840 sv = AvARRAY(av)[key];
9fb994be 841 if (sv) {
7e169e84
DM
842 PUSHs(sv);
843 RETURN;
844 }
845 }
846
847 /* ... else do it the hard way */
848 svp = av_fetch(av, key, lval);
849 sv = (svp ? *svp : &PL_sv_undef);
b024352e
DM
850
851 if (UNLIKELY(!svp && lval))
7e169e84 852 DIE(aTHX_ PL_no_aelem, (int)key);
b024352e 853
39cf747a 854 if (!lval && SvRMAGICAL(av) && SvGMAGICAL(sv)) /* see note in pp_helem() */
fd69380d 855 mg_get(sv);
be6c24e0 856 PUSHs(sv);
a0d0e21e
LW
857 RETURN;
858}
859
860PP(pp_join)
861{
20b7effb 862 dSP; dMARK; dTARGET;
a0d0e21e
LW
863 MARK++;
864 do_join(TARG, *MARK, MARK, SP);
865 SP = MARK;
866 SETs(TARG);
867 RETURN;
868}
869
a0d0e21e
LW
870/* Oversized hot code. */
871
b1c05ba5
DM
872/* also used for: pp_say() */
873
a0d0e21e
LW
874PP(pp_print)
875{
20b7effb 876 dSP; dMARK; dORIGMARK;
eb578fdb 877 PerlIO *fp;
236988e4 878 MAGIC *mg;
159b6efe
NC
879 GV * const gv
880 = (PL_op->op_flags & OPf_STACKED) ? MUTABLE_GV(*++MARK) : PL_defoutgv;
9c9f25b8 881 IO *io = GvIO(gv);
5b468f54 882
9c9f25b8 883 if (io
ad64d0ec 884 && (mg = SvTIED_mg((const SV *)io, PERL_MAGIC_tiedscalar)))
5b468f54 885 {
01bb7c6d 886 had_magic:
68dc0745 887 if (MARK == ORIGMARK) {
1c846c1f 888 /* If using default handle then we need to make space to
a60c0954
NIS
889 * pass object as 1st arg, so move other args up ...
890 */
4352c267 891 MEXTEND(SP, 1);
68dc0745
PP
892 ++MARK;
893 Move(MARK, MARK + 1, (SP - MARK) + 1, SV*);
894 ++SP;
895 }
3e0cb5de 896 return Perl_tied_method(aTHX_ SV_CONST(PRINT), mark - 1, MUTABLE_SV(io),
94bc412f
NC
897 mg,
898 (G_SCALAR | TIED_METHOD_ARGUMENTS_ON_STACK
899 | (PL_op->op_type == OP_SAY
900 ? TIED_METHOD_SAY : 0)), sp - mark);
236988e4 901 }
9c9f25b8 902 if (!io) {
68b590d9 903 if ( gv && GvEGVx(gv) && (io = GvIO(GvEGV(gv)))
ad64d0ec 904 && (mg = SvTIED_mg((const SV *)io, PERL_MAGIC_tiedscalar)))
01bb7c6d 905 goto had_magic;
51087808 906 report_evil_fh(gv);
93189314 907 SETERRNO(EBADF,RMS_IFI);
a0d0e21e
LW
908 goto just_say_no;
909 }
910 else if (!(fp = IoOFP(io))) {
7716c5c5
NC
911 if (IoIFP(io))
912 report_wrongway_fh(gv, '<');
51087808 913 else
7716c5c5 914 report_evil_fh(gv);
93189314 915 SETERRNO(EBADF,IoIFP(io)?RMS_FAC:RMS_IFI);
a0d0e21e
LW
916 goto just_say_no;
917 }
918 else {
e23d9e2f 919 SV * const ofs = GvSV(PL_ofsgv); /* $, */
a0d0e21e 920 MARK++;
e23d9e2f 921 if (ofs && (SvGMAGICAL(ofs) || SvOK(ofs))) {
a0d0e21e
LW
922 while (MARK <= SP) {
923 if (!do_print(*MARK, fp))
924 break;
925 MARK++;
926 if (MARK <= SP) {
e23d9e2f
CS
927 /* don't use 'ofs' here - it may be invalidated by magic callbacks */
928 if (!do_print(GvSV(PL_ofsgv), fp)) {
a0d0e21e
LW
929 MARK--;
930 break;
931 }
932 }
933 }
934 }
935 else {
936 while (MARK <= SP) {
937 if (!do_print(*MARK, fp))
938 break;
939 MARK++;
940 }
941 }
942 if (MARK <= SP)
943 goto just_say_no;
944 else {
cfc4a7da
GA
945 if (PL_op->op_type == OP_SAY) {
946 if (PerlIO_write(fp, "\n", 1) == 0 || PerlIO_error(fp))
947 goto just_say_no;
948 }
949 else if (PL_ors_sv && SvOK(PL_ors_sv))
7889fe52 950 if (!do_print(PL_ors_sv, fp)) /* $\ */
a0d0e21e
LW
951 goto just_say_no;
952
953 if (IoFLAGS(io) & IOf_FLUSH)
760ac839 954 if (PerlIO_flush(fp) == EOF)
a0d0e21e
LW
955 goto just_say_no;
956 }
957 }
958 SP = ORIGMARK;
e52fd6f4 959 XPUSHs(&PL_sv_yes);
a0d0e21e
LW
960 RETURN;
961
962 just_say_no:
963 SP = ORIGMARK;
e52fd6f4 964 XPUSHs(&PL_sv_undef);
a0d0e21e
LW
965 RETURN;
966}
967
b1c05ba5 968
aa36782f
DM
969/* do the common parts of pp_padhv() and pp_rv2hv()
970 * It assumes the caller has done EXTEND(SP, 1) or equivalent.
971 * 'is_keys' indicates the OPpPADHV_ISKEYS/OPpRV2HV_ISKEYS flag is set
972 * */
973
974PERL_STATIC_INLINE OP*
975S_padhv_rv2hv_common(pTHX_ HV *hv, U8 gimme, bool is_keys)
976{
977 bool tied;
978 dSP;
979
980 assert(PL_op->op_type == OP_PADHV || PL_op->op_type == OP_RV2HV);
981
982 if (gimme == G_ARRAY) {
983 PUSHs(MUTABLE_SV(hv));
984 PUTBACK;
985 return Perl_do_kv(aTHX);
986 }
987
988 if (is_keys)
989 /* 'keys %h' masquerading as '%h': reset iterator */
990 (void)hv_iterinit(hv);
991
992 tied = SvRMAGICAL(hv) && mg_find(MUTABLE_SV(hv), PERL_MAGIC_tied);
993
994 if ( ( PL_op->op_private & OPpTRUEBOOL
995 || ( PL_op->op_private & OPpMAYBE_TRUEBOOL
996 && block_gimme() == G_VOID)
997 )
998 && !tied
999 )
1000 PUSHs(HvUSEDKEYS(hv) ? &PL_sv_yes : &PL_sv_zero);
1001 else if (gimme == G_SCALAR) {
1002 if (is_keys) {
1003 IV i;
1004 if (tied) {
1005 i = 0;
1006 while (hv_iternext(hv))
1007 i++;
1008 }
1009 else
1010 i = HvUSEDKEYS(hv);
1011 mPUSHi(i);
1012 }
1013 else
1014 PUSHs(Perl_hv_scalar(aTHX_ hv));
1015 }
1016
1017 PUTBACK;
1018 return NORMAL;
1019}
1020
1021
e855b461
DM
1022/* This is also called directly by pp_lvavref. */
1023PP(pp_padav)
1024{
1025 dSP; dTARGET;
1026 U8 gimme;
1027 assert(SvTYPE(TARG) == SVt_PVAV);
1028 if (UNLIKELY( PL_op->op_private & OPpLVAL_INTRO ))
1029 if (LIKELY( !(PL_op->op_private & OPpPAD_STATE) ))
1030 SAVECLEARSV(PAD_SVl(PL_op->op_targ));
1031 EXTEND(SP, 1);
1032
1033 if (PL_op->op_flags & OPf_REF) {
1034 PUSHs(TARG);
1035 RETURN;
1036 }
1037 else if (PL_op->op_private & OPpMAYBE_LVSUB) {
1038 const I32 flags = is_lvalue_sub();
1039 if (flags && !(flags & OPpENTERSUB_INARGS)) {
1040 if (GIMME_V == G_SCALAR)
1041 /* diag_listed_as: Can't return %s to lvalue scalar context */
1042 Perl_croak(aTHX_ "Can't return array to lvalue scalar context");
1043 PUSHs(TARG);
1044 RETURN;
1045 }
1046 }
1047
1048 gimme = GIMME_V;
1049 if (gimme == G_ARRAY) {
1050 /* XXX see also S_pushav in pp_hot.c */
1051 const SSize_t maxarg = AvFILL(MUTABLE_AV(TARG)) + 1;
1052 EXTEND(SP, maxarg);
1053 if (SvMAGICAL(TARG)) {
1054 SSize_t i;
1055 for (i=0; i < maxarg; i++) {
1056 SV * const * const svp = av_fetch(MUTABLE_AV(TARG), i, FALSE);
1057 SP[i+1] = (svp) ? *svp : &PL_sv_undef;
1058 }
1059 }
1060 else {
1061 SSize_t i;
1062 for (i=0; i < maxarg; i++) {
1063 SV * const sv = AvARRAY((const AV *)TARG)[i];
1064 SP[i+1] = sv ? sv : &PL_sv_undef;
1065 }
1066 }
1067 SP += maxarg;
1068 }
1069 else if (gimme == G_SCALAR) {
1070 const SSize_t maxarg = AvFILL(MUTABLE_AV(TARG)) + 1;
1071 if (!maxarg)
1072 PUSHs(&PL_sv_zero);
1073 else if (PL_op->op_private & OPpTRUEBOOL)
1074 PUSHs(&PL_sv_yes);
1075 else
1076 mPUSHi(maxarg);
1077 }
1078 RETURN;
1079}
1080
1081
1082PP(pp_padhv)
1083{
1084 dSP; dTARGET;
1085 U8 gimme;
e855b461
DM
1086
1087 assert(SvTYPE(TARG) == SVt_PVHV);
e855b461
DM
1088 if (UNLIKELY( PL_op->op_private & OPpLVAL_INTRO ))
1089 if (LIKELY( !(PL_op->op_private & OPpPAD_STATE) ))
1090 SAVECLEARSV(PAD_SVl(PL_op->op_targ));
1091
aa36782f
DM
1092 EXTEND(SP, 1);
1093
1094 if (PL_op->op_flags & OPf_REF) {
1095 PUSHs(TARG);
e855b461 1096 RETURN;
aa36782f 1097 }
e855b461
DM
1098 else if (PL_op->op_private & OPpMAYBE_LVSUB) {
1099 const I32 flags = is_lvalue_sub();
1100 if (flags && !(flags & OPpENTERSUB_INARGS)) {
1101 if (GIMME_V == G_SCALAR)
1102 /* diag_listed_as: Can't return %s to lvalue scalar context */
1103 Perl_croak(aTHX_ "Can't return hash to lvalue scalar context");
aa36782f 1104 PUSHs(TARG);
e855b461
DM
1105 RETURN;
1106 }
1107 }
1108
1109 gimme = GIMME_V;
e855b461 1110
aa36782f
DM
1111 return S_padhv_rv2hv_common(aTHX_ (HV*)TARG, gimme,
1112 cBOOL(PL_op->op_private & OPpPADHV_ISKEYS));
e855b461
DM
1113}
1114
1115
b1c05ba5 1116/* also used for: pp_rv2hv() */
bdaf10a5 1117/* also called directly by pp_lvavref */
b1c05ba5 1118
a0d0e21e
LW
1119PP(pp_rv2av)
1120{
20b7effb 1121 dSP; dTOPss;
1c23e2bd 1122 const U8 gimme = GIMME_V;
13c59d41
MH
1123 static const char an_array[] = "an ARRAY";
1124 static const char a_hash[] = "a HASH";
bdaf10a5
FC
1125 const bool is_pp_rv2av = PL_op->op_type == OP_RV2AV
1126 || PL_op->op_type == OP_LVAVREF;
d83b45b8 1127 const svtype type = is_pp_rv2av ? SVt_PVAV : SVt_PVHV;
a0d0e21e 1128
9026059d 1129 SvGETMAGIC(sv);
a0d0e21e 1130 if (SvROK(sv)) {
5d9574c1 1131 if (UNLIKELY(SvAMAGIC(sv))) {
93d7320b 1132 sv = amagic_deref_call(sv, is_pp_rv2av ? to_av_amg : to_hv_amg);
93d7320b 1133 }
17ab7946 1134 sv = SvRV(sv);
5d9574c1 1135 if (UNLIKELY(SvTYPE(sv) != type))
dcbac5bb 1136 /* diag_listed_as: Not an ARRAY reference */
13c59d41 1137 DIE(aTHX_ "Not %s reference", is_pp_rv2av ? an_array : a_hash);
5d9574c1
DM
1138 else if (UNLIKELY(PL_op->op_flags & OPf_MOD
1139 && PL_op->op_private & OPpLVAL_INTRO))
3da99855 1140 Perl_croak(aTHX_ "%s", PL_no_localize_ref);
a0d0e21e 1141 }
5d9574c1 1142 else if (UNLIKELY(SvTYPE(sv) != type)) {
67955e0c 1143 GV *gv;
1c846c1f 1144
6e592b3a 1145 if (!isGV_with_GP(sv)) {
13c59d41 1146 gv = Perl_softref2xv(aTHX_ sv, is_pp_rv2av ? an_array : a_hash,
dc3c76f8
NC
1147 type, &sp);
1148 if (!gv)
1149 RETURN;
35cd451c
GS
1150 }
1151 else {
159b6efe 1152 gv = MUTABLE_GV(sv);
a0d0e21e 1153 }
ad64d0ec 1154 sv = is_pp_rv2av ? MUTABLE_SV(GvAVn(gv)) : MUTABLE_SV(GvHVn(gv));
533c011a 1155 if (PL_op->op_private & OPpLVAL_INTRO)
ad64d0ec 1156 sv = is_pp_rv2av ? MUTABLE_SV(save_ary(gv)) : MUTABLE_SV(save_hash(gv));
9f527363
FC
1157 }
1158 if (PL_op->op_flags & OPf_REF) {
17ab7946 1159 SETs(sv);
a0d0e21e 1160 RETURN;
9f527363 1161 }
5d9574c1 1162 else if (UNLIKELY(PL_op->op_private & OPpMAYBE_LVSUB)) {
40c94d11
FC
1163 const I32 flags = is_lvalue_sub();
1164 if (flags && !(flags & OPpENTERSUB_INARGS)) {
cde874ca 1165 if (gimme != G_ARRAY)
042560a6 1166 goto croak_cant_return;
17ab7946 1167 SETs(sv);
78f9721b 1168 RETURN;
40c94d11 1169 }
a0d0e21e
LW
1170 }
1171
17ab7946 1172 if (is_pp_rv2av) {
502c6561 1173 AV *const av = MUTABLE_AV(sv);
636fe681 1174 /* The guts of pp_rv2av */
96913b52 1175 if (gimme == G_ARRAY) {
d5524600
DM
1176 SP--;
1177 PUTBACK;
1178 S_pushav(aTHX_ av);
1179 SPAGAIN;
1c846c1f 1180 }
96913b52 1181 else if (gimme == G_SCALAR) {
c70927a6 1182 const SSize_t maxarg = AvFILL(av) + 1;
7be75ccf
DM
1183 if (PL_op->op_private & OPpTRUEBOOL)
1184 SETs(maxarg ? &PL_sv_yes : &PL_sv_zero);
1185 else {
1186 dTARGET;
1187 SETi(maxarg);
1188 }
93965878 1189 }
7be75ccf
DM
1190 }
1191 else {
aa36782f
DM
1192 SP--; PUTBACK;
1193 return S_padhv_rv2hv_common(aTHX_ (HV*)sv, gimme,
1194 cBOOL(PL_op->op_private & OPpRV2HV_ISKEYS));
17ab7946 1195 }
be85d344 1196 RETURN;
042560a6
NC
1197
1198 croak_cant_return:
1199 Perl_croak(aTHX_ "Can't return %s to lvalue scalar context",
1200 is_pp_rv2av ? "array" : "hash");
77e217c6 1201 RETURN;
a0d0e21e
LW
1202}
1203
10c8fecd 1204STATIC void
fb8f4cf8 1205S_do_oddball(pTHX_ SV **oddkey, SV **firstkey)
10c8fecd 1206{
7918f24d
NC
1207 PERL_ARGS_ASSERT_DO_ODDBALL;
1208
fb8f4cf8 1209 if (*oddkey) {
6d822dc4 1210 if (ckWARN(WARN_MISC)) {
a3b680e6 1211 const char *err;
fb8f4cf8
RZ
1212 if (oddkey == firstkey &&
1213 SvROK(*oddkey) &&
1214 (SvTYPE(SvRV(*oddkey)) == SVt_PVAV ||
1215 SvTYPE(SvRV(*oddkey)) == SVt_PVHV))
10c8fecd 1216 {
a3b680e6 1217 err = "Reference found where even-sized list expected";
10c8fecd
GS
1218 }
1219 else
a3b680e6 1220 err = "Odd number of elements in hash assignment";
f1f66076 1221 Perl_warner(aTHX_ packWARN(WARN_MISC), "%s", err);
10c8fecd 1222 }
6d822dc4 1223
10c8fecd
GS
1224 }
1225}
1226
a5f48505
DM
1227
1228/* Do a mark and sweep with the SVf_BREAK flag to detect elements which
1229 * are common to both the LHS and RHS of an aassign, and replace them
1230 * with copies. All these copies are made before the actual list assign is
1231 * done.
1232 *
1233 * For example in ($a,$b) = ($b,$a), assigning the value of the first RHS
1234 * element ($b) to the first LH element ($a), modifies $a; when the
1235 * second assignment is done, the second RH element now has the wrong
1236 * value. So we initially replace the RHS with ($b, mortalcopy($a)).
1237 * Note that we don't need to make a mortal copy of $b.
1238 *
1239 * The algorithm below works by, for every RHS element, mark the
1240 * corresponding LHS target element with SVf_BREAK. Then if the RHS
1241 * element is found with SVf_BREAK set, it means it would have been
1242 * modified, so make a copy.
1243 * Note that by scanning both LHS and RHS in lockstep, we avoid
1244 * unnecessary copies (like $b above) compared with a naive
1245 * "mark all LHS; copy all marked RHS; unmark all LHS".
1246 *
1247 * If the LHS element is a 'my' declaration' and has a refcount of 1, then
1248 * it can't be common and can be skipped.
ebc643ce
DM
1249 *
1250 * On DEBUGGING builds it takes an extra boolean, fake. If true, it means
1251 * that we thought we didn't need to call S_aassign_copy_common(), but we
1252 * have anyway for sanity checking. If we find we need to copy, then panic.
a5f48505
DM
1253 */
1254
1255PERL_STATIC_INLINE void
1256S_aassign_copy_common(pTHX_ SV **firstlelem, SV **lastlelem,
ebc643ce
DM
1257 SV **firstrelem, SV **lastrelem
1258#ifdef DEBUGGING
1259 , bool fake
1260#endif
1261)
a5f48505
DM
1262{
1263 dVAR;
1264 SV **relem;
1265 SV **lelem;
1266 SSize_t lcount = lastlelem - firstlelem + 1;
1267 bool marked = FALSE; /* have we marked any LHS with SVf_BREAK ? */
1268 bool const do_rc1 = cBOOL(PL_op->op_private & OPpASSIGN_COMMON_RC1);
beb08a1e 1269 bool copy_all = FALSE;
a5f48505
DM
1270
1271 assert(!PL_in_clean_all); /* SVf_BREAK not already in use */
1272 assert(firstlelem < lastlelem); /* at least 2 LH elements */
1273 assert(firstrelem < lastrelem); /* at least 2 RH elements */
1274
ebc643ce
DM
1275
1276 lelem = firstlelem;
a5f48505
DM
1277 /* we never have to copy the first RH element; it can't be corrupted
1278 * by assigning something to the corresponding first LH element.
1279 * So this scan does in a loop: mark LHS[N]; test RHS[N+1]
1280 */
ebc643ce 1281 relem = firstrelem + 1;
a5f48505
DM
1282
1283 for (; relem <= lastrelem; relem++) {
1284 SV *svr;
1285
1286 /* mark next LH element */
1287
1288 if (--lcount >= 0) {
1289 SV *svl = *lelem++;
1290
1291 if (UNLIKELY(!svl)) {/* skip AV alias marker */
1292 assert (lelem <= lastlelem);
1293 svl = *lelem++;
1294 lcount--;
1295 }
1296
1297 assert(svl);
beb08a1e
TC
1298 if (SvSMAGICAL(svl)) {
1299 copy_all = TRUE;
1300 }
a5f48505
DM
1301 if (SvTYPE(svl) == SVt_PVAV || SvTYPE(svl) == SVt_PVHV) {
1302 if (!marked)
1303 return;
1304 /* this LH element will consume all further args;
1305 * no need to mark any further LH elements (if any).
1306 * But we still need to scan any remaining RHS elements;
1307 * set lcount negative to distinguish from lcount == 0,
1308 * so the loop condition continues being true
1309 */
1310 lcount = -1;
1311 lelem--; /* no need to unmark this element */
1312 }
94a5f659 1313 else if (!(do_rc1 && SvREFCNT(svl) == 1) && !SvIMMORTAL(svl)) {
a5f48505
DM
1314 SvFLAGS(svl) |= SVf_BREAK;
1315 marked = TRUE;
1316 }
1317 else if (!marked) {
1318 /* don't check RH element if no SVf_BREAK flags set yet */
1319 if (!lcount)
1320 break;
1321 continue;
1322 }
1323 }
1324
1325 /* see if corresponding RH element needs copying */
1326
1327 assert(marked);
1328 svr = *relem;
1329 assert(svr);
1330
5c1db569 1331 if (UNLIKELY(SvFLAGS(svr) & (SVf_BREAK|SVs_GMG) || copy_all)) {
1050723f 1332 U32 brk = (SvFLAGS(svr) & SVf_BREAK);
a5f48505 1333
ebc643ce
DM
1334#ifdef DEBUGGING
1335 if (fake) {
9ae0115f 1336 /* op_dump(PL_op); */
ebc643ce
DM
1337 Perl_croak(aTHX_
1338 "panic: aassign skipped needed copy of common RH elem %"
1339 UVuf, (UV)(relem - firstrelem));
1340 }
1341#endif
1342
a5f48505
DM
1343 TAINT_NOT; /* Each item is independent */
1344
1345 /* Dear TODO test in t/op/sort.t, I love you.
1346 (It's relying on a panic, not a "semi-panic" from newSVsv()
1347 and then an assertion failure below.) */
1348 if (UNLIKELY(SvIS_FREED(svr))) {
1349 Perl_croak(aTHX_ "panic: attempt to copy freed scalar %p",
1350 (void*)svr);
1351 }
1352 /* avoid break flag while copying; otherwise COW etc
1353 * disabled... */
1354 SvFLAGS(svr) &= ~SVf_BREAK;
1355 /* Not newSVsv(), as it does not allow copy-on-write,
8c1e192f
DM
1356 resulting in wasteful copies.
1357 Also, we use SV_NOSTEAL in case the SV is used more than
1358 once, e.g. (...) = (f())[0,0]
1359 Where the same SV appears twice on the RHS without a ref
1360 count bump. (Although I suspect that the SV won't be
1361 stealable here anyway - DAPM).
1362 */
a5f48505
DM
1363 *relem = sv_mortalcopy_flags(svr,
1364 SV_GMAGIC|SV_DO_COW_SVSETSV|SV_NOSTEAL);
1365 /* ... but restore afterwards in case it's needed again,
1366 * e.g. ($a,$b,$c) = (1,$a,$a)
1367 */
1050723f 1368 SvFLAGS(svr) |= brk;
a5f48505
DM
1369 }
1370
1371 if (!lcount)
1372 break;
1373 }
1374
1375 if (!marked)
1376 return;
1377
1378 /*unmark LHS */
1379
1380 while (lelem > firstlelem) {
1381 SV * const svl = *(--lelem);
1382 if (svl)
1383 SvFLAGS(svl) &= ~SVf_BREAK;
1384 }
1385}
1386
1387
1388
a0d0e21e
LW
1389PP(pp_aassign)
1390{
27da23d5 1391 dVAR; dSP;
3280af22
NIS
1392 SV **lastlelem = PL_stack_sp;
1393 SV **lastrelem = PL_stack_base + POPMARK;
1394 SV **firstrelem = PL_stack_base + POPMARK + 1;
a0d0e21e
LW
1395 SV **firstlelem = lastrelem + 1;
1396
eb578fdb
KW
1397 SV **relem;
1398 SV **lelem;
1c23e2bd 1399 U8 gimme;
a68090fe
DM
1400 /* PL_delaymagic is restored by JUMPENV_POP on dieing, so we
1401 * only need to save locally, not on the save stack */
1402 U16 old_delaymagic = PL_delaymagic;
ebc643ce
DM
1403#ifdef DEBUGGING
1404 bool fake = 0;
1405#endif
5637b936 1406
3280af22 1407 PL_delaymagic = DM_DELAY; /* catch simultaneous items */
a0d0e21e
LW
1408
1409 /* If there's a common identifier on both sides we have to take
1410 * special care that assigning the identifier on the left doesn't
1411 * clobber a value on the right that's used later in the list.
1412 */
acdea6f0 1413
beb08a1e
TC
1414 /* at least 2 LH and RH elements, or commonality isn't an issue */
1415 if (firstlelem < lastlelem && firstrelem < lastrelem) {
5c1db569
TC
1416 for (relem = firstrelem+1; relem <= lastrelem; relem++) {
1417 if (SvGMAGICAL(*relem))
1418 goto do_scan;
1419 }
beb08a1e
TC
1420 for (lelem = firstlelem; lelem <= lastlelem; lelem++) {
1421 if (*lelem && SvSMAGICAL(*lelem))
1422 goto do_scan;
a5f48505 1423 }
beb08a1e
TC
1424 if ( PL_op->op_private & (OPpASSIGN_COMMON_SCALAR|OPpASSIGN_COMMON_RC1) ) {
1425 if (PL_op->op_private & OPpASSIGN_COMMON_RC1) {
1426 /* skip the scan if all scalars have a ref count of 1 */
1427 for (lelem = firstlelem; lelem <= lastlelem; lelem++) {
8b0c3377 1428 SV *sv = *lelem;
beb08a1e
TC
1429 if (!sv || SvREFCNT(sv) == 1)
1430 continue;
1431 if (SvTYPE(sv) != SVt_PVAV && SvTYPE(sv) != SVt_PVAV)
1432 goto do_scan;
1433 break;
1434 }
1435 }
1436 else {
1437 do_scan:
1438 S_aassign_copy_common(aTHX_
1439 firstlelem, lastlelem, firstrelem, lastrelem
ebc643ce 1440#ifdef DEBUGGING
beb08a1e 1441 , fake
ebc643ce 1442#endif
beb08a1e
TC
1443 );
1444 }
a5f48505 1445 }
a0d0e21e 1446 }
ebc643ce
DM
1447#ifdef DEBUGGING
1448 else {
1449 /* on debugging builds, do the scan even if we've concluded we
1450 * don't need to, then panic if we find commonality. Note that the
1451 * scanner assumes at least 2 elements */
1452 if (firstlelem < lastlelem && firstrelem < lastrelem) {
1453 fake = 1;
1454 goto do_scan;
1455 }
1456 }
1457#endif
a0d0e21e 1458
a5f48505 1459 gimme = GIMME_V;
a0d0e21e
LW
1460 relem = firstrelem;
1461 lelem = firstlelem;
10c8fecd 1462
8b0c3377
DM
1463 if (relem > lastrelem)
1464 goto no_relems;
1465
1466 /* first lelem loop while there are still relems */
5d9574c1 1467 while (LIKELY(lelem <= lastlelem)) {
bdaf10a5 1468 bool alias = FALSE;
8b0c3377
DM
1469 SV *lsv = *lelem++;
1470
c73f612f
DM
1471 TAINT_NOT; /* Each item stands on its own, taintwise. */
1472
8b0c3377
DM
1473 assert(relem <= lastrelem);
1474 if (UNLIKELY(!lsv)) {
bdaf10a5 1475 alias = TRUE;
8b0c3377
DM
1476 lsv = *lelem++;
1477 ASSUME(SvTYPE(lsv) == SVt_PVAV);
bdaf10a5 1478 }
a5f48505 1479
8b0c3377
DM
1480 switch (SvTYPE(lsv)) {
1481 case SVt_PVAV: {
1482 SV **svp;
1483 SSize_t i;
1484 SSize_t tmps_base;
1485 SSize_t nelems = lastrelem - relem + 1;
b09ed995 1486 AV *ary = MUTABLE_AV(lsv);
8b0c3377
DM
1487
1488 /* Assigning to an aggregate is tricky. First there is the
1489 * issue of commonality, e.g. @a = ($a[0]). Since the
1490 * stack isn't refcounted, clearing @a prior to storing
1491 * elements will free $a[0]. Similarly with
1492 * sub FETCH { $status[$_[1]] } @status = @tied[0,1];
1493 *
1494 * The way to avoid these issues is to make the copy of each
1495 * SV (and we normally store a *copy* in the array) *before*
1496 * clearing the array. But this has a problem in that
1497 * if the code croaks during copying, the not-yet-stored copies
1498 * could leak. One way to avoid this is to make all the copies
1499 * mortal, but that's quite expensive.
1500 *
1501 * The current solution to these issues is to use a chunk
1502 * of the tmps stack as a temporary refcounted-stack. SVs
1503 * will be put on there during processing to avoid leaks,
1504 * but will be removed again before the end of this block,
1505 * so free_tmps() is never normally called. Also, the
1506 * sv_refcnt of the SVs doesn't have to be manipulated, since
1507 * the ownership of 1 reference count is transferred directly
1508 * from the tmps stack to the AV when the SV is stored.
1509 *
1510 * We disarm slots in the temps stack by storing PL_sv_undef
1511 * there: it doesn't matter if that SV's refcount is
1512 * repeatedly decremented during a croak. But usually this is
1513 * only an interim measure. By the end of this code block
1514 * we try where possible to not leave any PL_sv_undef's on the
1515 * tmps stack e.g. by shuffling newer entries down.
1516 *
1517 * There is one case where we don't copy: non-magical
1518 * SvTEMP(sv)'s with a ref count of 1. The only owner of these
1519 * is on the tmps stack, so its safe to directly steal the SV
1520 * rather than copying. This is common in things like function
1521 * returns, map etc, which all return a list of such SVs.
1522 *
1523 * Note however something like @a = (f())[0,0], where there is
1524 * a danger of the same SV being shared: this avoided because
1525 * when the SV is stored as $a[0], its ref count gets bumped,
1526 * so the RC==1 test fails and the second element is copied
1527 * instead.
1528 *
1529 * We also use one slot in the tmps stack to hold an extra
1530 * ref to the array, to ensure it doesn't get prematurely
1531 * freed. Again, this is removed before the end of this block.
1532 *
1533 * Note that OPpASSIGN_COMMON_AGG is used to flag a possible
1534 * @a = ($a[0]) case, but the current implementation uses the
1535 * same algorithm regardless, so ignores that flag. (It *is*
1536 * used in the hash branch below, however).
1537 */
1538
1539 /* Reserve slots for ary, plus the elems we're about to copy,
1540 * then protect ary and temporarily void the remaining slots
1541 * with &PL_sv_undef */
1542 EXTEND_MORTAL(nelems + 1);
1543 PL_tmps_stack[++PL_tmps_ix] = SvREFCNT_inc_simple_NN(ary);
1544 tmps_base = PL_tmps_ix + 1;
1545 for (i = 0; i < nelems; i++)
1546 PL_tmps_stack[tmps_base + i] = &PL_sv_undef;
1547 PL_tmps_ix += nelems;
1548
1549 /* Make a copy of each RHS elem and save on the tmps_stack
1550 * (or pass through where we can optimise away the copy) */
1551
1552 if (UNLIKELY(alias)) {
1553 U32 lval = (gimme == G_ARRAY)
1554 ? (PL_op->op_flags & OPf_MOD || LVRET) : 0;
a5f48505 1555 for (svp = relem; svp <= lastrelem; svp++) {
8b0c3377
DM
1556 SV *rsv = *svp;
1557
1558 SvGETMAGIC(rsv);
1559 if (!SvROK(rsv))
1560 DIE(aTHX_ "Assigned value is not a reference");
1561 if (SvTYPE(SvRV(rsv)) > SVt_PVLV)
1562 /* diag_listed_as: Assigned value is not %s reference */
1563 DIE(aTHX_
1564 "Assigned value is not a SCALAR reference");
1565 if (lval)
1566 *svp = rsv = sv_mortalcopy(rsv);
1567 /* XXX else check for weak refs? */
1568 rsv = SvREFCNT_inc_NN(SvRV(rsv));
1569 assert(tmps_base <= PL_tmps_max);
1570 PL_tmps_stack[tmps_base++] = rsv;
a5f48505 1571 }
a5f48505 1572 }
8b0c3377
DM
1573 else {
1574 for (svp = relem; svp <= lastrelem; svp++) {
1575 SV *rsv = *svp;
a5f48505 1576
8b0c3377
DM
1577 if (SvTEMP(rsv) && !SvGMAGICAL(rsv) && SvREFCNT(rsv) == 1) {
1578 /* can skip the copy */
1579 SvREFCNT_inc_simple_void_NN(rsv);
1580 SvTEMP_off(rsv);
1581 }
a5f48505 1582 else {
8b0c3377
DM
1583 SV *nsv;
1584 /* do get before newSV, in case it dies and leaks */
1585 SvGETMAGIC(rsv);
1586 nsv = newSV(0);
8c1e192f
DM
1587 /* see comment in S_aassign_copy_common about
1588 * SV_NOSTEAL */
8b0c3377
DM
1589 sv_setsv_flags(nsv, rsv,
1590 (SV_DO_COW_SVSETSV|SV_NOSTEAL));
1591 rsv = *svp = nsv;
a5f48505 1592 }
8b0c3377
DM
1593
1594 assert(tmps_base <= PL_tmps_max);
1595 PL_tmps_stack[tmps_base++] = rsv;
1596 }
1597 }
1598
1599 if (SvRMAGICAL(ary) || AvFILLp(ary) >= 0) /* may be non-empty */
1600 av_clear(ary);
1601
1602 /* store in the array, the SVs that are in the tmps stack */
1603
1604 tmps_base -= nelems;
1605
80c1439f 1606 if (SvMAGICAL(ary) || SvREADONLY(ary) || !AvREAL(ary)) {
8b0c3377
DM
1607 /* for arrays we can't cheat with, use the official API */
1608 av_extend(ary, nelems - 1);
1609 for (i = 0; i < nelems; i++) {
1610 SV **svp = &(PL_tmps_stack[tmps_base + i]);
1611 SV *rsv = *svp;
1612 /* A tied store won't take ownership of rsv, so keep
1613 * the 1 refcnt on the tmps stack; otherwise disarm
1614 * the tmps stack entry */
1615 if (av_store(ary, i, rsv))
1616 *svp = &PL_sv_undef;
1617 /* av_store() may have added set magic to rsv */;
1618 SvSETMAGIC(rsv);
1619 }
1620 /* disarm ary refcount: see comments below about leak */
1621 PL_tmps_stack[tmps_base - 1] = &PL_sv_undef;
1622 }
1623 else {
1624 /* directly access/set the guts of the AV */
1625 SSize_t fill = nelems - 1;
1626 if (fill > AvMAX(ary))
1627 av_extend_guts(ary, fill, &AvMAX(ary), &AvALLOC(ary),
1628 &AvARRAY(ary));
1629 AvFILLp(ary) = fill;
1630 Copy(&(PL_tmps_stack[tmps_base]), AvARRAY(ary), nelems, SV*);
1631 /* Quietly remove all the SVs from the tmps stack slots,
1632 * since ary has now taken ownership of the refcnt.
1633 * Also remove ary: which will now leak if we die before
1634 * the SvREFCNT_dec_NN(ary) below */
1635 if (UNLIKELY(PL_tmps_ix >= tmps_base + nelems))
1636 Move(&PL_tmps_stack[tmps_base + nelems],
1637 &PL_tmps_stack[tmps_base - 1],
1638 PL_tmps_ix - (tmps_base + nelems) + 1,
1639 SV*);
1640 PL_tmps_ix -= (nelems + 1);
1641 }
1642
5d9574c1 1643 if (UNLIKELY(PL_delaymagic & DM_ARRAY_ISA))
8b0c3377 1644 /* its assumed @ISA set magic can't die and leak ary */
ad64d0ec 1645 SvSETMAGIC(MUTABLE_SV(ary));
8b0c3377
DM
1646 SvREFCNT_dec_NN(ary);
1647
1648 relem = lastrelem + 1;
1649 goto no_relems;
a5f48505
DM
1650 }
1651
10c8fecd 1652 case SVt_PVHV: { /* normal hash */
8b0c3377
DM
1653
1654 SV **svp;
1655 bool dirty_tmps;
1656 SSize_t i;
1657 SSize_t tmps_base;
1658 SSize_t nelems = lastrelem - relem + 1;
b09ed995 1659 HV *hash = MUTABLE_HV(lsv);
8b0c3377
DM
1660
1661 if (UNLIKELY(nelems & 1)) {
1662 do_oddball(lastrelem, relem);
1663 /* we have firstlelem to reuse, it's not needed any more */
1664 *++lastrelem = &PL_sv_undef;
1665 nelems++;
1666 }
1667
1668 /* See the SVt_PVAV branch above for a long description of
1669 * how the following all works. The main difference for hashes
1670 * is that we treat keys and values separately (and have
1671 * separate loops for them): as for arrays, values are always
1672 * copied (except for the SvTEMP optimisation), since they
1673 * need to be stored in the hash; while keys are only
1674 * processed where they might get prematurely freed or
1675 * whatever. */
1676
1677 /* tmps stack slots:
1678 * * reserve a slot for the hash keepalive;
1679 * * reserve slots for the hash values we're about to copy;
1680 * * preallocate for the keys we'll possibly copy or refcount bump
1681 * later;
1682 * then protect hash and temporarily void the remaining
1683 * value slots with &PL_sv_undef */
1684 EXTEND_MORTAL(nelems + 1);
1685
1686 /* convert to number of key/value pairs */
1687 nelems >>= 1;
1688
1689 PL_tmps_stack[++PL_tmps_ix] = SvREFCNT_inc_simple_NN(hash);
1690 tmps_base = PL_tmps_ix + 1;
1691 for (i = 0; i < nelems; i++)
1692 PL_tmps_stack[tmps_base + i] = &PL_sv_undef;
1693 PL_tmps_ix += nelems;
1694
1695 /* Make a copy of each RHS hash value and save on the tmps_stack
1696 * (or pass through where we can optimise away the copy) */
1697
1698 for (svp = relem + 1; svp <= lastrelem; svp += 2) {
1699 SV *rsv = *svp;
1700
1701 if (SvTEMP(rsv) && !SvGMAGICAL(rsv) && SvREFCNT(rsv) == 1) {
1702 /* can skip the copy */
1703 SvREFCNT_inc_simple_void_NN(rsv);
1704 SvTEMP_off(rsv);
1705 }
1706 else {
1707 SV *nsv;
1708 /* do get before newSV, in case it dies and leaks */
1709 SvGETMAGIC(rsv);
1710 nsv = newSV(0);
1711 /* see comment in S_aassign_copy_common about
1712 * SV_NOSTEAL */
1713 sv_setsv_flags(nsv, rsv,
1714 (SV_DO_COW_SVSETSV|SV_NOSTEAL));
1715 rsv = *svp = nsv;
1c4ea384
RZ
1716 }
1717
8b0c3377
DM
1718 assert(tmps_base <= PL_tmps_max);
1719 PL_tmps_stack[tmps_base++] = rsv;
1720 }
1721 tmps_base -= nelems;
a5f48505 1722
a5f48505 1723
8b0c3377
DM
1724 /* possibly protect keys */
1725
1726 if (UNLIKELY(gimme == G_ARRAY)) {
1727 /* handle e.g.
1728 * @a = ((%h = ($$r, 1)), $r = "x");
1729 * $_++ for %h = (1,2,3,4);
1730 */
1731 EXTEND_MORTAL(nelems);
1732 for (svp = relem; svp <= lastrelem; svp += 2)
1733 *svp = sv_mortalcopy_flags(*svp,
1734 SV_GMAGIC|SV_DO_COW_SVSETSV|SV_NOSTEAL);
1735 }
1736 else if (PL_op->op_private & OPpASSIGN_COMMON_AGG) {
1737 /* for possible commonality, e.g.
1738 * %h = ($h{a},1)
1739 * avoid premature freeing RHS keys by mortalising
1740 * them.
1741 * For a magic element, make a copy so that its magic is
1742 * called *before* the hash is emptied (which may affect
1743 * a tied value for example).
1744 * In theory we should check for magic keys in all
1745 * cases, not just under OPpASSIGN_COMMON_AGG, but in
1746 * practice, !OPpASSIGN_COMMON_AGG implies only
1747 * constants or padtmps on the RHS.
1748 */
1749 EXTEND_MORTAL(nelems);
1750 for (svp = relem; svp <= lastrelem; svp += 2) {
1751 SV *rsv = *svp;
1752 if (UNLIKELY(SvGMAGICAL(rsv))) {
1753 SSize_t n;
a5f48505
DM
1754 *svp = sv_mortalcopy_flags(*svp,
1755 SV_GMAGIC|SV_DO_COW_SVSETSV|SV_NOSTEAL);
8b0c3377
DM
1756 /* allow other branch to continue pushing
1757 * onto tmps stack without checking each time */
1758 n = (lastrelem - relem) >> 1;
1759 EXTEND_MORTAL(n);
a5f48505 1760 }
8b0c3377
DM
1761 else
1762 PL_tmps_stack[++PL_tmps_ix] =
1763 SvREFCNT_inc_simple_NN(rsv);
a5f48505 1764 }
8b0c3377 1765 }
a5f48505 1766
8b0c3377
DM
1767 if (SvRMAGICAL(hash) || HvUSEDKEYS(hash))
1768 hv_clear(hash);
a5f48505 1769
8b0c3377
DM
1770 /* now assign the keys and values to the hash */
1771
1772 dirty_tmps = FALSE;
1773
1774 if (UNLIKELY(gimme == G_ARRAY)) {
1775 /* @a = (%h = (...)) etc */
1776 SV **svp;
1777 SV **topelem = relem;
1778
1779 for (i = 0, svp = relem; svp <= lastrelem; i++, svp++) {
1780 SV *key = *svp++;
1781 SV *val = *svp;
1782 /* remove duplicates from list we return */
1783 if (!hv_exists_ent(hash, key, 0)) {
1784 /* copy key back: possibly to an earlier
1785 * stack location if we encountered dups earlier,
1786 * The values will be updated later
1787 */
1788 *topelem = key;
1789 topelem += 2;
632b9d6f 1790 }
8b0c3377
DM
1791 /* A tied store won't take ownership of val, so keep
1792 * the 1 refcnt on the tmps stack; otherwise disarm
1793 * the tmps stack entry */
1794 if (hv_store_ent(hash, key, val, 0))
1795 PL_tmps_stack[tmps_base + i] = &PL_sv_undef;
1796 else
1797 dirty_tmps = TRUE;
1798 /* hv_store_ent() may have added set magic to val */;
1799 SvSETMAGIC(val);
1800 }
1801 if (topelem < svp) {
1c4ea384
RZ
1802 /* at this point we have removed the duplicate key/value
1803 * pairs from the stack, but the remaining values may be
1804 * wrong; i.e. with (a 1 a 2 b 3) on the stack we've removed
1805 * the (a 2), but the stack now probably contains
1806 * (a <freed> b 3), because { hv_save(a,1); hv_save(a,2) }
1807 * obliterates the earlier key. So refresh all values. */
8b0c3377
DM
1808 lastrelem = topelem - 1;
1809 while (relem < lastrelem) {
1c4ea384
RZ
1810 HE *he;
1811 he = hv_fetch_ent(hash, *relem++, 0, 0);
1812 *relem++ = (he ? HeVAL(he) : &PL_sv_undef);
1813 }
1814 }
8b0c3377
DM
1815 }
1816 else {
1817 SV **svp;
1818 for (i = 0, svp = relem; svp <= lastrelem; i++, svp++) {
1819 SV *key = *svp++;
1820 SV *val = *svp;
1821 if (hv_store_ent(hash, key, val, 0))
1822 PL_tmps_stack[tmps_base + i] = &PL_sv_undef;
1823 else
1824 dirty_tmps = TRUE;
1825 /* hv_store_ent() may have added set magic to val */;
1826 SvSETMAGIC(val);
1827 }
1828 }
1829
1830 if (dirty_tmps) {
1831 /* there are still some 'live' recounts on the tmps stack
1832 * - usually caused by storing into a tied hash. So let
1833 * free_tmps() do the proper but slow job later.
1834 * Just disarm hash refcount: see comments below about leak
1835 */
1836 PL_tmps_stack[tmps_base - 1] = &PL_sv_undef;
1837 }
1838 else {
1839 /* Quietly remove all the SVs from the tmps stack slots,
1840 * since hash has now taken ownership of the refcnt.
1841 * Also remove hash: which will now leak if we die before
1842 * the SvREFCNT_dec_NN(hash) below */
1843 if (UNLIKELY(PL_tmps_ix >= tmps_base + nelems))
1844 Move(&PL_tmps_stack[tmps_base + nelems],
1845 &PL_tmps_stack[tmps_base - 1],
1846 PL_tmps_ix - (tmps_base + nelems) + 1,
1847 SV*);
1848 PL_tmps_ix -= (nelems + 1);
1849 }
1850
1851 SvREFCNT_dec_NN(hash);
1852
1853 relem = lastrelem + 1;
1854 goto no_relems;
1855 }
1856
a0d0e21e 1857 default:
8b0c3377 1858 if (!SvIMMORTAL(lsv)) {
d24e3eb1
DM
1859 SV *ref;
1860
8b0c3377
DM
1861 if (UNLIKELY(
1862 SvTEMP(lsv) && !SvSMAGICAL(lsv) && SvREFCNT(lsv) == 1 &&
1863 (!isGV_with_GP(lsv) || SvFAKE(lsv)) && ckWARN(WARN_MISC)
1864 ))
1865 Perl_warner(aTHX_
1866 packWARN(WARN_MISC),
1867 "Useless assignment to a temporary"
1868 );
d24e3eb1
DM
1869
1870 /* avoid freeing $$lsv if it might be needed for further
1871 * elements, e.g. ($ref, $foo) = (1, $$ref) */
1872 if ( SvROK(lsv)
1873 && ( ((ref = SvRV(lsv)), SvREFCNT(ref)) == 1)
1874 && lelem <= lastlelem
1875 ) {
1876 SSize_t ix;
1877 SvREFCNT_inc_simple_void_NN(ref);
1878 /* an unrolled sv_2mortal */
1879 ix = ++PL_tmps_ix;
1880 if (UNLIKELY(ix >= PL_tmps_max))
1881 /* speculatively grow enough to cover other
1882 * possible refs */
67c3640a 1883 (void)tmps_grow_p(ix + (lastlelem - lelem));
d24e3eb1
DM
1884 PL_tmps_stack[ix] = ref;
1885 }
1886
8b0c3377
DM
1887 sv_setsv(lsv, *relem);
1888 *relem = lsv;
1889 SvSETMAGIC(lsv);
1890 }
1891 if (++relem > lastrelem)
1892 goto no_relems;
a0d0e21e 1893 break;
8b0c3377
DM
1894 } /* switch */
1895 } /* while */
1896
1897
1898 no_relems:
1899
1900 /* simplified lelem loop for when there are no relems left */
1901 while (LIKELY(lelem <= lastlelem)) {
1902 SV *lsv = *lelem++;
c73f612f
DM
1903
1904 TAINT_NOT; /* Each item stands on its own, taintwise. */
1905
8b0c3377
DM
1906 if (UNLIKELY(!lsv)) {
1907 lsv = *lelem++;
1908 ASSUME(SvTYPE(lsv) == SVt_PVAV);
a0d0e21e 1909 }
8b0c3377
DM
1910
1911 switch (SvTYPE(lsv)) {
1912 case SVt_PVAV:
b09ed995
DM
1913 if (SvRMAGICAL(lsv) || AvFILLp((SV*)lsv) >= 0) {
1914 av_clear((AV*)lsv);
8b0c3377 1915 if (UNLIKELY(PL_delaymagic & DM_ARRAY_ISA))
b09ed995 1916 SvSETMAGIC(lsv);
8b0c3377
DM
1917 }
1918 break;
1919
1920 case SVt_PVHV:
b09ed995
DM
1921 if (SvRMAGICAL(lsv) || HvUSEDKEYS((HV*)lsv))
1922 hv_clear((HV*)lsv);
8b0c3377
DM
1923 break;
1924
1925 default:
1926 if (!SvIMMORTAL(lsv)) {
e03e82a0 1927 sv_set_undef(lsv);
8b0c3377 1928 SvSETMAGIC(lsv);
b09ed995 1929 *relem++ = lsv;
8b0c3377
DM
1930 }
1931 break;
1932 } /* switch */
1933 } /* while */
1934
c73f612f
DM
1935 TAINT_NOT; /* result of list assign isn't tainted */
1936
5d9574c1 1937 if (UNLIKELY(PL_delaymagic & ~DM_DELAY)) {
985213f2 1938 /* Will be used to set PL_tainting below */
dfff4baf
BF
1939 Uid_t tmp_uid = PerlProc_getuid();
1940 Uid_t tmp_euid = PerlProc_geteuid();
1941 Gid_t tmp_gid = PerlProc_getgid();
1942 Gid_t tmp_egid = PerlProc_getegid();
985213f2 1943
b469f1e0 1944 /* XXX $> et al currently silently ignore failures */
3280af22 1945 if (PL_delaymagic & DM_UID) {
a0d0e21e 1946#ifdef HAS_SETRESUID
b469f1e0
JH
1947 PERL_UNUSED_RESULT(
1948 setresuid((PL_delaymagic & DM_RUID) ? PL_delaymagic_uid : (Uid_t)-1,
1949 (PL_delaymagic & DM_EUID) ? PL_delaymagic_euid : (Uid_t)-1,
1950 (Uid_t)-1));
56febc5e
AD
1951#else
1952# ifdef HAS_SETREUID
b469f1e0
JH
1953 PERL_UNUSED_RESULT(
1954 setreuid((PL_delaymagic & DM_RUID) ? PL_delaymagic_uid : (Uid_t)-1,
1955 (PL_delaymagic & DM_EUID) ? PL_delaymagic_euid : (Uid_t)-1));
56febc5e
AD
1956# else
1957# ifdef HAS_SETRUID
b28d0864 1958 if ((PL_delaymagic & DM_UID) == DM_RUID) {
b469f1e0 1959 PERL_UNUSED_RESULT(setruid(PL_delaymagic_uid));
b28d0864 1960 PL_delaymagic &= ~DM_RUID;
a0d0e21e 1961 }
56febc5e
AD
1962# endif /* HAS_SETRUID */
1963# ifdef HAS_SETEUID
b28d0864 1964 if ((PL_delaymagic & DM_UID) == DM_EUID) {
b469f1e0 1965 PERL_UNUSED_RESULT(seteuid(PL_delaymagic_euid));
b28d0864 1966 PL_delaymagic &= ~DM_EUID;
a0d0e21e 1967 }
56febc5e 1968# endif /* HAS_SETEUID */
b28d0864 1969 if (PL_delaymagic & DM_UID) {
985213f2 1970 if (PL_delaymagic_uid != PL_delaymagic_euid)
cea2e8a9 1971 DIE(aTHX_ "No setreuid available");
b469f1e0 1972 PERL_UNUSED_RESULT(PerlProc_setuid(PL_delaymagic_uid));
a0d0e21e 1973 }
56febc5e
AD
1974# endif /* HAS_SETREUID */
1975#endif /* HAS_SETRESUID */
04783dc7 1976
985213f2
AB
1977 tmp_uid = PerlProc_getuid();
1978 tmp_euid = PerlProc_geteuid();
a0d0e21e 1979 }
b469f1e0 1980 /* XXX $> et al currently silently ignore failures */
3280af22 1981 if (PL_delaymagic & DM_GID) {
a0d0e21e 1982#ifdef HAS_SETRESGID
b469f1e0
JH
1983 PERL_UNUSED_RESULT(
1984 setresgid((PL_delaymagic & DM_RGID) ? PL_delaymagic_gid : (Gid_t)-1,
1985 (PL_delaymagic & DM_EGID) ? PL_delaymagic_egid : (Gid_t)-1,
1986 (Gid_t)-1));
56febc5e
AD
1987#else
1988# ifdef HAS_SETREGID
b469f1e0
JH
1989 PERL_UNUSED_RESULT(
1990 setregid((PL_delaymagic & DM_RGID) ? PL_delaymagic_gid : (Gid_t)-1,
1991 (PL_delaymagic & DM_EGID) ? PL_delaymagic_egid : (Gid_t)-1));
56febc5e
AD
1992# else
1993# ifdef HAS_SETRGID
b28d0864 1994 if ((PL_delaymagic & DM_GID) == DM_RGID) {
b469f1e0 1995 PERL_UNUSED_RESULT(setrgid(PL_delaymagic_gid));
b28d0864 1996 PL_delaymagic &= ~DM_RGID;
a0d0e21e 1997 }
56febc5e
AD
1998# endif /* HAS_SETRGID */
1999# ifdef HAS_SETEGID
b28d0864 2000 if ((PL_delaymagic & DM_GID) == DM_EGID) {
b469f1e0 2001 PERL_UNUSED_RESULT(setegid(PL_delaymagic_egid));
b28d0864 2002 PL_delaymagic &= ~DM_EGID;
a0d0e21e 2003 }
56febc5e 2004# endif /* HAS_SETEGID */
b28d0864 2005 if (PL_delaymagic & DM_GID) {
985213f2 2006 if (PL_delaymagic_gid != PL_delaymagic_egid)
cea2e8a9 2007 DIE(aTHX_ "No setregid available");
b469f1e0 2008 PERL_UNUSED_RESULT(PerlProc_setgid(PL_delaymagic_gid));
a0d0e21e 2009 }
56febc5e
AD
2010# endif /* HAS_SETREGID */
2011#endif /* HAS_SETRESGID */
04783dc7 2012
985213f2
AB
2013 tmp_gid = PerlProc_getgid();
2014 tmp_egid = PerlProc_getegid();
a0d0e21e 2015 }
284167a5 2016 TAINTING_set( TAINTING_get | (tmp_uid && (tmp_euid != tmp_uid || tmp_egid != tmp_gid)) );
9a9b5ec9
DM
2017#ifdef NO_TAINT_SUPPORT
2018 PERL_UNUSED_VAR(tmp_uid);
2019 PERL_UNUSED_VAR(tmp_euid);
2020 PERL_UNUSED_VAR(tmp_gid);
2021 PERL_UNUSED_VAR(tmp_egid);
2022#endif
a0d0e21e 2023 }
a68090fe 2024 PL_delaymagic = old_delaymagic;
54310121 2025
54310121
PP
2026 if (gimme == G_VOID)
2027 SP = firstrelem - 1;
2028 else if (gimme == G_SCALAR) {
54310121 2029 SP = firstrelem;
b09ed995 2030 EXTEND(SP,1);
7b394f12
DM
2031 if (PL_op->op_private & OPpASSIGN_TRUEBOOL)
2032 SETs((firstlelem - firstrelem) ? &PL_sv_yes : &PL_sv_zero);
2033 else {
2034 dTARGET;
2035 SETi(firstlelem - firstrelem);
2036 }
54310121 2037 }
b09ed995
DM
2038 else
2039 SP = relem - 1;
08aeb9f7 2040
54310121 2041 RETURN;
a0d0e21e
LW
2042}
2043
8782bef2
GB
2044PP(pp_qr)
2045{
20b7effb 2046 dSP;
eb578fdb 2047 PMOP * const pm = cPMOP;
fe578d7f 2048 REGEXP * rx = PM_GETRE(pm);
196a02af
DM
2049 regexp *prog = ReANY(rx);
2050 SV * const pkg = RXp_ENGINE(prog)->qr_package(aTHX_ (rx));
c4420975 2051 SV * const rv = sv_newmortal();
d63c20f2
DM
2052 CV **cvp;
2053 CV *cv;
288b8c02
NC
2054
2055 SvUPGRADE(rv, SVt_IV);
c2123ae3
NC
2056 /* For a subroutine describing itself as "This is a hacky workaround" I'm
2057 loathe to use it here, but it seems to be the right fix. Or close.
2058 The key part appears to be that it's essential for pp_qr to return a new
2059 object (SV), which implies that there needs to be an effective way to
2060 generate a new SV from the existing SV that is pre-compiled in the
2061 optree. */
2062 SvRV_set(rv, MUTABLE_SV(reg_temp_copy(NULL, rx)));
288b8c02
NC
2063 SvROK_on(rv);
2064
8d919b0a 2065 cvp = &( ReANY((REGEXP *)SvRV(rv))->qr_anoncv);
5d9574c1 2066 if (UNLIKELY((cv = *cvp) && CvCLONE(*cvp))) {
d63c20f2 2067 *cvp = cv_clone(cv);
fc2b2dca 2068 SvREFCNT_dec_NN(cv);
d63c20f2
DM
2069 }
2070
288b8c02 2071 if (pkg) {
f815daf2 2072 HV *const stash = gv_stashsv(pkg, GV_ADD);
fc2b2dca 2073 SvREFCNT_dec_NN(pkg);
288b8c02
NC
2074 (void)sv_bless(rv, stash);
2075 }
2076
196a02af 2077 if (UNLIKELY(RXp_ISTAINTED(prog))) {
e08e52cf 2078 SvTAINTED_on(rv);
9274aefd
DM
2079 SvTAINTED_on(SvRV(rv));
2080 }
c8c13c22 2081 XPUSHs(rv);
2082 RETURN;
8782bef2
GB
2083}
2084
a0d0e21e
LW
2085PP(pp_match)
2086{
20b7effb 2087 dSP; dTARG;
eb578fdb 2088 PMOP *pm = cPMOP;
d65afb4b 2089 PMOP *dynpm = pm;
eb578fdb 2090 const char *s;
5c144d81 2091 const char *strend;
99a90e59 2092 SSize_t curpos = 0; /* initial pos() or current $+[0] */
a0d0e21e 2093 I32 global;
7fadf4a7 2094 U8 r_flags = 0;
5c144d81 2095 const char *truebase; /* Start of string */
eb578fdb 2096 REGEXP *rx = PM_GETRE(pm);
196a02af 2097 regexp *prog = ReANY(rx);
b3eb6a9b 2098 bool rxtainted;
1c23e2bd 2099 const U8 gimme = GIMME_V;
a0d0e21e 2100 STRLEN len;
a3b680e6 2101 const I32 oldsave = PL_savestack_ix;
e60df1fa 2102 I32 had_zerolen = 0;
b1422d62 2103 MAGIC *mg = NULL;
a0d0e21e 2104
533c011a 2105 if (PL_op->op_flags & OPf_STACKED)
a0d0e21e
LW
2106 TARG = POPs;
2107 else {
9399c607
DM
2108 if (ARGTARG)
2109 GETTARGET;
2110 else {
2111 TARG = DEFSV;
2112 }
a0d0e21e
LW
2113 EXTEND(SP,1);
2114 }
d9f424b2 2115
c277df42 2116 PUTBACK; /* EVAL blocks need stack_sp. */
69dc4b30
FC
2117 /* Skip get-magic if this is a qr// clone, because regcomp has
2118 already done it. */
196a02af 2119 truebase = prog->mother_re
69dc4b30
FC
2120 ? SvPV_nomg_const(TARG, len)
2121 : SvPV_const(TARG, len);
f1d31338 2122 if (!truebase)
2269b42e 2123 DIE(aTHX_ "panic: pp_match");
f1d31338 2124 strend = truebase + len;
196a02af 2125 rxtainted = (RXp_ISTAINTED(prog) ||
284167a5 2126 (TAINT_get && (pm->op_pmflags & PMf_RETAINT)));
9212bbba 2127 TAINT_NOT;
a0d0e21e 2128
6c864ec2 2129 /* We need to know this in case we fail out early - pos() must be reset */
de0df3c0
MH
2130 global = dynpm->op_pmflags & PMf_GLOBAL;
2131
d65afb4b 2132 /* PMdf_USED is set after a ?? matches once */
c737faaf
YO
2133 if (
2134#ifdef USE_ITHREADS
2135 SvREADONLY(PL_regex_pad[pm->op_pmoffset])
2136#else
2137 pm->op_pmflags & PMf_USED
2138#endif
2139 ) {
e5dc5375 2140 DEBUG_r(PerlIO_printf(Perl_debug_log, "?? already matched once"));
de0df3c0 2141 goto nope;
a0d0e21e
LW
2142 }
2143
5585e758 2144 /* handle the empty pattern */
196a02af 2145 if (!RX_PRELEN(rx) && PL_curpm && !prog->mother_re) {
5585e758
YO
2146 if (PL_curpm == PL_reg_curpm) {
2147 if (PL_curpm_under) {
2148 if (PL_curpm_under == PL_reg_curpm) {
2149 Perl_croak(aTHX_ "Infinite recursion via empty pattern");
2150 } else {
2151 pm = PL_curpm_under;
2152 }
2153 }
2154 } else {
2155 pm = PL_curpm;
2156 }
2157 rx = PM_GETRE(pm);
196a02af 2158 prog = ReANY(rx);
a0d0e21e 2159 }
d65afb4b 2160
196a02af 2161 if (RXp_MINLEN(prog) >= 0 && (STRLEN)RXp_MINLEN(prog) > len) {
75d43e96 2162 DEBUG_r(PerlIO_printf(Perl_debug_log, "String shorter than min possible regex match (%"
147e3846 2163 UVuf " < %" IVdf ")\n",
196a02af 2164 (UV)len, (IV)RXp_MINLEN(prog)));
de0df3c0 2165 goto nope;
e5dc5375 2166 }
c277df42 2167
8ef97b0e 2168 /* get pos() if //g */
de0df3c0 2169 if (global) {
b1422d62 2170 mg = mg_find_mglob(TARG);
8ef97b0e 2171 if (mg && mg->mg_len >= 0) {
25fdce4a 2172 curpos = MgBYTEPOS(mg, TARG, truebase, len);
8ef97b0e
DM
2173 /* last time pos() was set, it was zero-length match */
2174 if (mg->mg_flags & MGf_MINMATCH)
2175 had_zerolen = 1;
2176 }
a0d0e21e 2177 }
8ef97b0e 2178
6e240d0b 2179#ifdef PERL_SAWAMPERSAND
196a02af 2180 if ( RXp_NPARENS(prog)
6502e081 2181 || PL_sawampersand
196a02af 2182 || (RXp_EXTFLAGS(prog) & (RXf_EVAL_SEEN|RXf_PMf_KEEPCOPY))
5b0e71e9 2183 || (dynpm->op_pmflags & PMf_KEEPCOPY)
6e240d0b
FC
2184 )
2185#endif
2186 {
6502e081
DM
2187 r_flags |= (REXEC_COPY_STR|REXEC_COPY_SKIP_PRE);
2188 /* in @a =~ /(.)/g, we iterate multiple times, but copy the buffer
2189 * only on the first iteration. Therefore we need to copy $' as well
2190 * as $&, to make the rest of the string available for captures in
2191 * subsequent iterations */
2192 if (! (global && gimme == G_ARRAY))
2193 r_flags |= REXEC_COPY_SKIP_POST;
2194 };
5b0e71e9
DM
2195#ifdef PERL_SAWAMPERSAND
2196 if (dynpm->op_pmflags & PMf_KEEPCOPY)
2197 /* handle KEEPCOPY in pmop but not rx, eg $r=qr/a/; /$r/p */
2198 r_flags &= ~(REXEC_COPY_SKIP_PRE|REXEC_COPY_SKIP_POST);
2199#endif
22e551b9 2200
f1d31338
DM
2201 s = truebase;
2202
d7be1480 2203 play_it_again:
985afbc1 2204 if (global)
03c83e26 2205 s = truebase + curpos;
f722798b 2206
77da2310 2207 if (!CALLREGEXEC(rx, (char*)s, (char *)strend, (char*)truebase,
03c83e26 2208 had_zerolen, TARG, NULL, r_flags))
03b6c93d 2209 goto nope;
77da2310
NC
2210
2211 PL_curpm = pm;
985afbc1 2212 if (dynpm->op_pmflags & PMf_ONCE)
c737faaf 2213#ifdef USE_ITHREADS
77da2310 2214 SvREADONLY_on(PL_regex_pad[dynpm->op_pmoffset]);
c737faaf 2215#else
77da2310 2216 dynpm->op_pmflags |= PMf_USED;
c737faaf 2217#endif
a0d0e21e 2218
72311751 2219 if (rxtainted)
196a02af
DM
2220 RXp_MATCH_TAINTED_on(prog);
2221 TAINT_IF(RXp_MATCH_TAINTED(prog));
35c2ccc3
DM
2222
2223 /* update pos */
2224
2225 if (global && (gimme != G_ARRAY || (dynpm->op_pmflags & PMf_CONTINUE))) {
b1422d62 2226 if (!mg)
35c2ccc3 2227 mg = sv_magicext_mglob(TARG);
196a02af
DM
2228 MgBYTEPOS_set(mg, TARG, truebase, RXp_OFFS(prog)[0].end);
2229 if (RXp_ZERO_LEN(prog))
adf51885
DM
2230 mg->mg_flags |= MGf_MINMATCH;
2231 else
2232 mg->mg_flags &= ~MGf_MINMATCH;
35c2ccc3
DM
2233 }
2234
196a02af 2235 if ((!RXp_NPARENS(prog) && !global) || gimme != G_ARRAY) {
bf9dff51
DM
2236 LEAVE_SCOPE(oldsave);
2237 RETPUSHYES;
2238 }
2239
88ab22af
DM
2240 /* push captures on stack */
2241
bf9dff51 2242 {
196a02af 2243 const I32 nparens = RXp_NPARENS(prog);
a3b680e6 2244 I32 i = (global && !nparens) ? 1 : 0;
a0d0e21e 2245
c277df42 2246 SPAGAIN; /* EVAL blocks could move the stack. */
ffc61ed2
JH
2247 EXTEND(SP, nparens + i);
2248 EXTEND_MORTAL(nparens + i);
2249 for (i = !i; i <= nparens; i++) {
a0d0e21e 2250 PUSHs(sv_newmortal());
196a02af
DM
2251 if (LIKELY((RXp_OFFS(prog)[i].start != -1)
2252 && RXp_OFFS(prog)[i].end != -1 ))
5d9574c1 2253 {
196a02af
DM
2254 const I32 len = RXp_OFFS(prog)[i].end - RXp_OFFS(prog)[i].start;
2255 const char * const s = RXp_OFFS(prog)[i].start + truebase;
2256 if (UNLIKELY( RXp_OFFS(prog)[i].end < 0
2257 || RXp_OFFS(prog)[i].start < 0
2258 || len < 0
2259 || len > strend - s)
2260 )
5637ef5b 2261 DIE(aTHX_ "panic: pp_match start/end pointers, i=%ld, "
147e3846 2262 "start=%ld, end=%ld, s=%p, strend=%p, len=%" UVuf,
196a02af
DM
2263 (long) i, (long) RXp_OFFS(prog)[i].start,
2264 (long)RXp_OFFS(prog)[i].end, s, strend, (UV) len);
a0d0e21e 2265 sv_setpvn(*SP, s, len);
cce850e4 2266 if (DO_UTF8(TARG) && is_utf8_string((U8*)s, len))
a197cbdd 2267 SvUTF8_on(*SP);
a0d0e21e
LW
2268 }
2269 }
2270 if (global) {
196a02af
DM
2271 curpos = (UV)RXp_OFFS(prog)[0].end;
2272 had_zerolen = RXp_ZERO_LEN(prog);
c277df42 2273 PUTBACK; /* EVAL blocks may use stack */
cf93c79d 2274 r_flags |= REXEC_IGNOREPOS | REXEC_NOT_FIRST;
a0d0e21e
LW
2275 goto play_it_again;
2276 }
4633a7c4 2277 LEAVE_SCOPE(oldsave);
a0d0e21e
LW
2278 RETURN;
2279 }
e5964223 2280 NOT_REACHED; /* NOTREACHED */
a0d0e21e 2281
7b52d656 2282 nope:
d65afb4b 2283 if (global && !(dynpm->op_pmflags & PMf_CONTINUE)) {
b1422d62
DM
2284 if (!mg)
2285 mg = mg_find_mglob(TARG);
2286 if (mg)
2287 mg->mg_len = -1;
a0d0e21e 2288 }
4633a7c4 2289 LEAVE_SCOPE(oldsave);
a0d0e21e
LW
2290 if (gimme == G_ARRAY)
2291 RETURN;
2292 RETPUSHNO;
2293}
2294
2295OP *
864dbfa3 2296Perl_do_readline(pTHX)
a0d0e21e 2297{
20b7effb 2298 dSP; dTARGETSTACKED;
eb578fdb 2299 SV *sv;
a0d0e21e
LW
2300 STRLEN tmplen = 0;
2301 STRLEN offset;
760ac839 2302 PerlIO *fp;
eb578fdb
KW
2303 IO * const io = GvIO(PL_last_in_gv);
2304 const I32 type = PL_op->op_type;
1c23e2bd 2305 const U8 gimme = GIMME_V;
a0d0e21e 2306
6136c704 2307 if (io) {
50db69d8 2308 const MAGIC *const mg = SvTIED_mg((const SV *)io, PERL_MAGIC_tiedscalar);
6136c704 2309 if (mg) {
3e0cb5de 2310 Perl_tied_method(aTHX_ SV_CONST(READLINE), SP, MUTABLE_SV(io), mg, gimme, 0);
6136c704 2311 if (gimme == G_SCALAR) {
50db69d8
NC
2312 SPAGAIN;
2313 SvSetSV_nosteal(TARG, TOPs);
2314 SETTARG;
6136c704 2315 }
50db69d8 2316 return NORMAL;
0b7c7b4f 2317 }
e79b0511 2318 }
4608196e 2319 fp = NULL;
a0d0e21e
LW
2320 if (io) {
2321 fp = IoIFP(io);
2322 if (!fp) {
2323 if (IoFLAGS(io) & IOf_ARGV) {
2324 if (IoFLAGS(io) & IOf_START) {
a0d0e21e 2325 IoLINES(io) = 0;
b9f2b683 2326 if (av_tindex(GvAVn(PL_last_in_gv)) < 0) {
1d7c1841 2327 IoFLAGS(io) &= ~IOf_START;
d5eb9a46 2328 do_open6(PL_last_in_gv, "-", 1, NULL, NULL, 0);
4bac9ae4 2329 SvTAINTED_off(GvSVn(PL_last_in_gv)); /* previous tainting irrelevant */
76f68e9b 2330 sv_setpvs(GvSVn(PL_last_in_gv), "-");
3280af22 2331 SvSETMAGIC(GvSV(PL_last_in_gv));
a2008d6d
GS
2332 fp = IoIFP(io);
2333 goto have_fp;
a0d0e21e
LW
2334 }
2335 }
157fb5a1 2336 fp = nextargv(PL_last_in_gv, PL_op->op_flags & OPf_SPECIAL);
a0d0e21e 2337 if (!fp) { /* Note: fp != IoIFP(io) */
3280af22 2338 (void)do_close(PL_last_in_gv, FALSE); /* now it does*/
a0d0e21e
LW
2339 }
2340 }
0d44d22b
NC
2341 else if (type == OP_GLOB)
2342 fp = Perl_start_glob(aTHX_ POPs, io);
a0d0e21e
LW
2343 }
2344 else if (type == OP_GLOB)
2345 SP--;
7716c5c5 2346 else if (IoTYPE(io) == IoTYPE_WRONLY) {
a5390457 2347 report_wrongway_fh(PL_last_in_gv, '>');
a00b5bd3 2348 }
a0d0e21e
LW
2349 }
2350 if (!fp) {
041457d9 2351 if ((!io || !(IoFLAGS(io) & IOf_START))
de7dabb6
TC
2352 && ckWARN(WARN_CLOSED)
2353 && type != OP_GLOB)
041457d9 2354 {
de7dabb6 2355 report_evil_fh(PL_last_in_gv);
3f4520fe 2356 }
54310121 2357 if (gimme == G_SCALAR) {
79628082 2358 /* undef TARG, and push that undefined value */
ba92458f 2359 if (type != OP_RCATLINE) {
3773545d 2360 sv_set_undef(TARG);
ba92458f 2361 }
a0d0e21e
LW
2362 PUSHTARG;
2363 }
2364 RETURN;
2365 }
a2008d6d 2366 have_fp:
54310121 2367 if (gimme == G_SCALAR) {
a0d0e21e 2368 sv = TARG;
0f722b55
RGS
2369 if (type == OP_RCATLINE && SvGMAGICAL(sv))
2370 mg_get(sv);
48de12d9
RGS
2371 if (SvROK(sv)) {
2372 if (type == OP_RCATLINE)
5668452f 2373 SvPV_force_nomg_nolen(sv);
48de12d9
RGS
2374 else
2375 sv_unref(sv);
2376 }
f7877b28 2377 else if (isGV_with_GP(sv)) {
5668452f 2378 SvPV_force_nomg_nolen(sv);
f7877b28 2379 }
862a34c6 2380 SvUPGRADE(sv, SVt_PV);
a0d0e21e 2381 tmplen = SvLEN(sv); /* remember if already alloced */
e3918bb7 2382 if (!tmplen && !SvREADONLY(sv) && !SvIsCOW(sv)) {
f72e8700
JJ
2383 /* try short-buffering it. Please update t/op/readline.t
2384 * if you change the growth length.
2385 */
2386 Sv_Grow(sv, 80);
2387 }
2b5e58c4
AMS
2388 offset = 0;
2389 if (type == OP_RCATLINE && SvOK(sv)) {
2390 if (!SvPOK(sv)) {
5668452f 2391 SvPV_force_nomg_nolen(sv);
2b5e58c4 2392 }
a0d0e21e 2393 offset = SvCUR(sv);
2b5e58c4 2394 }
a0d0e21e 2395 }
54310121 2396 else {
561b68a9 2397 sv = sv_2mortal(newSV(80));
54310121
PP
2398 offset = 0;
2399 }
fbad3eb5 2400
3887d568
AP
2401 /* This should not be marked tainted if the fp is marked clean */
2402#define MAYBE_TAINT_LINE(io, sv) \
2403 if (!(IoFLAGS(io) & IOf_UNTAINT)) { \
2404 TAINT; \
2405 SvTAINTED_on(sv); \
2406 }
2407
684bef36 2408/* delay EOF state for a snarfed empty file */
fbad3eb5 2409#define SNARF_EOF(gimme,rs,io,sv) \
684bef36 2410 (gimme != G_SCALAR || SvCUR(sv) \
b9fee9ba 2411 || (IoFLAGS(io) & IOf_NOLINE) || !RsSNARF(rs))
fbad3eb5 2412
a0d0e21e 2413 for (;;) {
09e8efcc 2414 PUTBACK;
fbad3eb5 2415 if (!sv_gets(sv, fp, offset)
2d726892
TF
2416 && (type == OP_GLOB
2417 || SNARF_EOF(gimme, PL_rs, io, sv)
2418 || PerlIO_error(fp)))
fbad3eb5 2419 {
760ac839 2420 PerlIO_clearerr(fp);
a0d0e21e 2421 if (IoFLAGS(io) & IOf_ARGV) {
157fb5a1 2422 fp = nextargv(PL_last_in_gv, PL_op->op_flags & OPf_SPECIAL);
a0d0e21e
LW
2423 if (fp)
2424 continue;
3280af22 2425 (void)do_close(PL_last_in_gv, FALSE);
a0d0e21e
LW
2426 }
2427 else if (type == OP_GLOB) {
a2a5de95
NC
2428 if (!do_close(PL_last_in_gv, FALSE)) {
2429 Perl_ck_warner(aTHX_ packWARN(WARN_GLOB),
2430 "glob failed (child exited with status %d%s)",
2431 (int)(STATUS_CURRENT >> 8),
2432 (STATUS_CURRENT & 0x80) ? ", core dumped" : "");
4eb79ab5 2433 }
a0d0e21e 2434 }
54310121 2435 if (gimme == G_SCALAR) {
ba92458f
AE
2436 if (type != OP_RCATLINE) {
2437 SV_CHECK_THINKFIRST_COW_DROP(TARG);
0c34ef67 2438 SvOK_off(TARG);
ba92458f 2439 }
09e8efcc 2440 SPAGAIN;
a0d0e21e
LW
2441 PUSHTARG;
2442 }
3887d568 2443 MAYBE_TAINT_LINE(io, sv);
a0d0e21e
LW
2444 RETURN;
2445 }
3887d568 2446 MAYBE_TAINT_LINE(io, sv);
a0d0e21e 2447 IoLINES(io)++;
b9fee9ba 2448 IoFLAGS(io) |= IOf_NOLINE;
71be2cbc 2449 SvSETMAGIC(sv);
09e8efcc 2450 SPAGAIN;
a0d0e21e 2451 XPUSHs(sv);
a0d0e21e 2452 if (type == OP_GLOB) {
349d4f2f 2453 const char *t1;
45a23732 2454 Stat_t statbuf;
a0d0e21e 2455
3280af22 2456 if (SvCUR(sv) > 0 && SvCUR(PL_rs) > 0) {
6136c704 2457 char * const tmps = SvEND(sv) - 1;
aa07b2f6 2458 if (*tmps == *SvPVX_const(PL_rs)) {
c07a80fd 2459 *tmps = '\0';
b162af07 2460 SvCUR_set(sv, SvCUR(sv) - 1);
c07a80fd
PP
2461 }
2462 }
349d4f2f 2463 for (t1 = SvPVX_const(sv); *t1; t1++)
b51c3e77
CB
2464#ifdef __VMS
2465 if (strchr("*%?", *t1))
2466#else
7ad1e72d 2467 if (strchr("$&*(){}[]'\";\\|?<>~`", *t1))
b51c3e77 2468#endif
a0d0e21e 2469 break;
45a23732 2470 if (*t1 && PerlLIO_lstat(SvPVX_const(sv), &statbuf) < 0) {
a0d0e21e
LW
2471 (void)POPs; /* Unmatched wildcard? Chuck it... */
2472 continue;
2473 }
2d79bf7f 2474 } else if (SvUTF8(sv)) { /* OP_READLINE, OP_RCATLINE */
d4c19fe8
AL
2475 if (ckWARN(WARN_UTF8)) {
2476 const U8 * const s = (const U8*)SvPVX_const(sv) + offset;
2477 const STRLEN len = SvCUR(sv) - offset;
2478 const U8 *f;
2479
2480 if (!is_utf8_string_loc(s, len, &f))
2481 /* Emulate :encoding(utf8) warning in the same case. */
2482 Perl_warner(aTHX_ packWARN(WARN_UTF8),
2483 "utf8 \"\\x%02X\" does not map to Unicode",
2484 f < (U8*)SvEND(sv) ? *f : 0);
2485 }
a0d0e21e 2486 }
54310121 2487 if (gimme == G_ARRAY) {
a0d0e21e 2488 if (SvLEN(sv) - SvCUR(sv) > 20) {
1da4ca5f 2489 SvPV_shrink_to_cur(sv);
a0d0e21e 2490 }
561b68a9 2491 sv = sv_2mortal(newSV(80));
a0d0e21e
LW
2492 continue;
2493 }
54310121 2494 else if (gimme == G_SCALAR && !tmplen && SvLEN(sv) - SvCUR(sv) > 80) {
a0d0e21e 2495 /* try to reclaim a bit of scalar space (only on 1st alloc) */
d5b5861b
NC
2496 const STRLEN new_len
2497 = SvCUR(sv) < 60 ? 80 : SvCUR(sv)+40; /* allow some slop */
1da4ca5f 2498 SvPV_renew(sv, new_len);
a0d0e21e
LW
2499 }
2500 RETURN;
2501 }
2502}
2503
a0d0e21e
LW
2504PP(pp_helem)
2505{
20b7effb 2506 dSP;
760ac839 2507 HE* he;
ae77835f 2508 SV **svp;
c445ea15 2509 SV * const keysv = POPs;
85fbaab2 2510 HV * const hv = MUTABLE_HV(POPs);
a3b680e6
AL
2511 const U32 lval = PL_op->op_flags & OPf_MOD || LVRET;
2512 const U32 defer = PL_op->op_private & OPpLVAL_DEFER;
be6c24e0 2513 SV *sv;
92970b93 2514 const bool localizing = PL_op->op_private & OPpLVAL_INTRO;
d30e492c 2515 bool preeminent = TRUE;
a0d0e21e 2516
6dfc73ea
SM
2517 if (SvTYPE(hv) != SVt_PVHV)
2518 RETPUSHUNDEF;
d4c19fe8 2519
92970b93 2520 if (localizing) {
d4c19fe8
AL
2521 MAGIC *mg;
2522 HV *stash;
d30e492c
VP
2523
2524 /* If we can determine whether the element exist,
2525 * Try to preserve the existenceness of a tied hash
2526 * element by using EXISTS and DELETE if possible.
2527 * Fallback to FETCH and STORE otherwise. */
2c5f48c2 2528 if (SvCANEXISTDELETE(hv))
d30e492c 2529 preeminent = hv_exists_ent(hv, keysv, 0);
d4c19fe8 2530 }
d30e492c 2531
5f9d7e2b 2532 he = hv_fetch_ent(hv, keysv, lval && !defer, 0);
d4c19fe8 2533 svp = he ? &HeVAL(he) : NULL;
a0d0e21e 2534 if (lval) {
746f6409 2535 if (!svp || !*svp || *svp == &PL_sv_undef) {
68dc0745
PP
2536 SV* lv;
2537 SV* key2;
2d8e6c8d 2538 if (!defer) {
be2597df 2539 DIE(aTHX_ PL_no_helem_sv, SVfARG(keysv));
2d8e6c8d 2540 }
68dc0745
PP
2541 lv = sv_newmortal();
2542 sv_upgrade(lv, SVt_PVLV);
2543 LvTYPE(lv) = 'y';
6136c704 2544 sv_magic(lv, key2 = newSVsv(keysv), PERL_MAGIC_defelem, NULL, 0);
fc2b2dca 2545 SvREFCNT_dec_NN(key2); /* sv_magic() increments refcount */
0ad694a7 2546 LvTARG(lv) = SvREFCNT_inc_simple_NN(hv);
68dc0745
PP
2547 LvTARGLEN(lv) = 1;
2548 PUSHs(lv);
2549 RETURN;
2550 }
92970b93 2551 if (localizing) {
bfcb3514 2552 if (HvNAME_get(hv) && isGV(*svp))
159b6efe 2553 save_gp(MUTABLE_GV(*svp), !(PL_op->op_flags & OPf_SPECIAL));
47cfc530
VP
2554 else if (preeminent)
2555 save_helem_flags(hv, keysv, svp,
2556 (PL_op->op_flags & OPf_SPECIAL) ? 0 : SAVEf_SETMAGIC);
2557 else
2558 SAVEHDELETE(hv, keysv);
5f05dabc 2559 }
9026059d
GG
2560 else if (PL_op->op_private & OPpDEREF) {
2561 PUSHs(vivify_ref(*svp, PL_op->op_private & OPpDEREF));
2562 RETURN;
2563 }
a0d0e21e 2564 }
746f6409 2565 sv = (svp && *svp ? *svp : &PL_sv_undef);
fd69380d
DM
2566 /* Originally this did a conditional C<sv = sv_mortalcopy(sv)>; this
2567 * was to make C<local $tied{foo} = $tied{foo}> possible.
2568 * However, it seems no longer to be needed for that purpose, and
2569 * introduced a new bug: stuff like C<while ($hash{taintedval} =~ /.../g>
2570 * would loop endlessly since the pos magic is getting set on the
2571 * mortal copy and lost. However, the copy has the effect of
2572 * triggering the get magic, and losing it altogether made things like
2573 * c<$tied{foo};> in void context no longer do get magic, which some
2574 * code relied on. Also, delayed triggering of magic on @+ and friends
2575 * meant the original regex may be out of scope by now. So as a
2576 * compromise, do the get magic here. (The MGf_GSKIP flag will stop it
2577 * being called too many times). */
39cf747a 2578 if (!lval && SvRMAGICAL(hv) && SvGMAGICAL(sv))
fd69380d 2579 mg_get(sv);
be6c24e0 2580 PUSHs(sv);
a0d0e21e
LW
2581 RETURN;
2582}
2583
fedf30e1
DM
2584
2585/* a stripped-down version of Perl_softref2xv() for use by
2586 * pp_multideref(), which doesn't use PL_op->op_flags */
2587
f9db5646 2588STATIC GV *
fedf30e1
DM
2589S_softref2xv_lite(pTHX_ SV *const sv, const char *const what,
2590 const svtype type)
2591{
2592 if (PL_op->op_private & HINT_STRICT_REFS) {
2593 if (SvOK(sv))
2594 Perl_die(aTHX_ PL_no_symref_sv, sv,
2595 (SvPOKp(sv) && SvCUR(sv)>32 ? "..." : ""), what);
2596 else
2597 Perl_die(aTHX_ PL_no_usym, what);
2598 }
2599 if (!SvOK(sv))
2600 Perl_die(aTHX_ PL_no_usym, what);
2601 return gv_fetchsv_nomg(sv, GV_ADD, type);
2602}
2603
2604
79815f56
DM
2605/* Handle one or more aggregate derefs and array/hash indexings, e.g.
2606 * $h->{foo} or $a[0]{$key}[$i] or f()->[1]
fedf30e1
DM
2607 *
2608 * op_aux points to an array of unions of UV / IV / SV* / PADOFFSET.
79815f56
DM
2609 * Each of these either contains a set of actions, or an argument, such as
2610 * an IV to use as an array index, or a lexical var to retrieve.
2611 * Several actions re stored per UV; we keep shifting new actions off the
2612 * one UV, and only reload when it becomes zero.
fedf30e1
DM
2613 */
2614
2615PP(pp_multideref)
2616{
2617 SV *sv = NULL; /* init to avoid spurious 'may be used uninitialized' */
2618 UNOP_AUX_item *items = cUNOP_AUXx(PL_op)->op_aux;
2619 UV actions = items->uv;
2620
2621 assert(actions);
2622 /* this tells find_uninit_var() where we're up to */
2623 PL_multideref_pc = items;
2624
2625 while (1) {
2626 /* there are three main classes of action; the first retrieve
2627 * the initial AV or HV from a variable or the stack; the second
2628 * does the equivalent of an unrolled (/DREFAV, rv2av, aelem),
2629 * the third an unrolled (/DREFHV, rv2hv, helem).
2630 */
2631 switch (actions & MDEREF_ACTION_MASK) {
2632
2633 case MDEREF_reload:
2634 actions = (++items)->uv;
2635 continue;
2636
2637 case MDEREF_AV_padav_aelem: /* $lex[...] */
2638 sv = PAD_SVl((++items)->pad_offset);
2639 goto do_AV_aelem;
2640
2641 case MDEREF_AV_gvav_aelem: /* $pkg[...] */
2642 sv = UNOP_AUX_item_sv(++items);
2643 assert(isGV_with_GP(sv));
2644 sv = (SV*)GvAVn((GV*)sv);
2645 goto do_AV_aelem;
2646
2647 case MDEREF_AV_pop_rv2av_aelem: /* expr->[...] */
2648 {
2649 dSP;
2650 sv = POPs;
2651 PUTBACK;
2652 goto do_AV_rv2av_aelem;
2653 }
2654
2655 case MDEREF_AV_gvsv_vivify_rv2av_aelem: /* $pkg->[...] */
2656 sv = UNOP_AUX_item_sv(++items);
2657 assert(isGV_with_GP(sv));
2658 sv = GvSVn((GV*)sv);
2659 goto do_AV_vivify_rv2av_aelem;
2660
2661 case MDEREF_AV_padsv_vivify_rv2av_aelem: /* $lex->[...] */
2662 sv = PAD_SVl((++items)->pad_offset);
2663 /* FALLTHROUGH */
2664
2665 do_AV_vivify_rv2av_aelem:
2666 case MDEREF_AV_vivify_rv2av_aelem: /* vivify, ->[...] */
2667 /* this is the OPpDEREF action normally found at the end of
2668 * ops like aelem, helem, rv2sv */
2669 sv = vivify_ref(sv, OPpDEREF_AV);
2670 /* FALLTHROUGH */
2671
2672 do_AV_rv2av_aelem:
2673 /* this is basically a copy of pp_rv2av when it just has the
2674 * sKR/1 flags */
2675 SvGETMAGIC(sv);
2676 if (LIKELY(SvROK(sv))) {
2677 if (UNLIKELY(SvAMAGIC(sv))) {
2678 sv = amagic_deref_call(sv, to_av_amg);
2679 }
2680 sv = SvRV(sv);
2681 if (UNLIKELY(SvTYPE(sv) != SVt_PVAV))
2682 DIE(aTHX_ "Not an ARRAY reference");
2683 }
2684 else if (SvTYPE(sv) != SVt_PVAV) {
2685 if (!isGV_with_GP(sv))
2686 sv = (SV*)S_softref2xv_lite(aTHX_ sv, "an ARRAY", SVt_PVAV);
2687 sv = MUTABLE_SV(GvAVn((GV*)sv));
2688 }
2689 /* FALLTHROUGH */
2690
2691 do_AV_aelem:
2692 {
2693 /* retrieve the key; this may be either a lexical or package
2694 * var (whose index/ptr is stored as an item) or a signed
2695 * integer constant stored as an item.
2696 */
2697 SV *elemsv;
2698 IV elem = 0; /* to shut up stupid compiler warnings */
2699
2700
2701 assert(SvTYPE(sv) == SVt_PVAV);
2702
2703 switch (actions & MDEREF_INDEX_MASK) {
2704 case MDEREF_INDEX_none:
2705 goto finish;
2706 case MDEREF_INDEX_const:
2707 elem = (++items)->iv;
2708 break;
2709 case MDEREF_INDEX_padsv:
2710 elemsv = PAD_SVl((++items)->pad_offset);
2711 goto check_elem;
2712 case MDEREF_INDEX_gvsv:
2713 elemsv = UNOP_AUX_item_sv(++items);
2714 assert(isGV_with_GP(elemsv));
2715 elemsv = GvSVn((GV*)elemsv);
2716 check_elem:
2717 if (UNLIKELY(SvROK(elemsv) && !SvGAMAGIC(elemsv)
2718 && ckWARN(WARN_MISC)))
2719 Perl_warner(aTHX_ packWARN(WARN_MISC),
147e3846 2720 "Use of reference \"%" SVf "\" as array index",
fedf30e1
DM
2721 SVfARG(elemsv));
2722 /* the only time that S_find_uninit_var() needs this
2723 * is to determine which index value triggered the
2724 * undef warning. So just update it here. Note that
2725 * since we don't save and restore this var (e.g. for
2726 * tie or overload execution), its value will be
2727 * meaningless apart from just here */
2728 PL_multideref_pc = items;
2729 elem = SvIV(elemsv);
2730 break;
2731 }
2732
2733
2734 /* this is basically a copy of pp_aelem with OPpDEREF skipped */
2735
2736 if (!(actions & MDEREF_FLAG_last)) {
2737 SV** svp = av_fetch((AV*)sv, elem, 1);
2738 if (!svp || ! (sv=*svp))
2739 DIE(aTHX_ PL_no_aelem, elem);
2740 break;
2741 }
2742
2743 if (PL_op->op_private &
2744 (OPpMULTIDEREF_EXISTS|OPpMULTIDEREF_DELETE))
2745 {
2746 if (PL_op->op_private & OPpMULTIDEREF_EXISTS) {
2747 sv = av_exists((AV*)sv, elem) ? &PL_sv_yes : &PL_sv_no;
2748 }
2749 else {
2750 I32 discard = (GIMME_V == G_VOID) ? G_DISCARD : 0;
2751 sv = av_delete((AV*)sv, elem, discard);
2752 if (discard)
2753 return NORMAL;
2754 if (!sv)
2755 sv = &PL_sv_undef;
2756 }
2757 }
2758 else {
2759 const U32 lval = PL_op->op_flags & OPf_MOD || LVRET;
2760 const U32 defer = PL_op->op_private & OPpLVAL_DEFER;
2761 const bool localizing = PL_op->op_private & OPpLVAL_INTRO;
2762 bool preeminent = TRUE;
2763 AV *const av = (AV*)sv;
2764 SV** svp;
2765
2766 if (UNLIKELY(localizing)) {
2767 MAGIC *mg;
2768 HV *stash;
2769
2770 /* If we can determine whether the element exist,
2771 * Try to preserve the existenceness of a tied array
2772 * element by using EXISTS and DELETE if possible.
2773 * Fallback to FETCH and STORE otherwise. */
2774 if (SvCANEXISTDELETE(av))
2775 preeminent = av_exists(av, elem);
2776 }
2777
2778 svp = av_fetch(av, elem, lval && !defer);
2779
2780 if (lval) {
2781 if (!svp || !(sv = *svp)) {
2782 IV len;
2783 if (!defer)
2784 DIE(aTHX_ PL_no_aelem, elem);
2785 len = av_tindex(av);
2786 sv = sv_2mortal(newSVavdefelem(av,
2787 /* Resolve a negative index now, unless it points
2788 * before the beginning of the array, in which
2789 * case record it for error reporting in
2790 * magic_setdefelem. */
2791 elem < 0 && len + elem >= 0
2792 ? len + elem : elem, 1));
2793 }
2794 else {
2795 if (UNLIKELY(localizing)) {
2796 if (preeminent) {
2797 save_aelem(av, elem, svp);
2798 sv = *svp; /* may have changed */
2799 }
2800 else
2801 SAVEADELETE(av, elem);
2802 }
2803 }
2804 }
2805 else {
2806 sv = (svp ? *svp : &PL_sv_undef);
2807 /* see note in pp_helem() */
2808 if (SvRMAGICAL(av) && SvGMAGICAL(sv))
2809 mg_get(sv);
2810 }
2811 }
2812
2813 }
2814 finish:
2815 {
2816 dSP;
2817 XPUSHs(sv);
2818 RETURN;
2819 }
2820 /* NOTREACHED */
2821
2822
2823
2824
2825 case MDEREF_HV_padhv_helem: /* $lex{...} */
2826 sv = PAD_SVl((++items)->pad_offset);
2827 goto do_HV_helem;
2828
2829 case MDEREF_HV_gvhv_helem: /* $pkg{...} */
2830 sv = UNOP_AUX_item_sv(++items);
2831 assert(isGV_with_GP(sv));
2832 sv = (SV*)GvHVn((GV*)sv);
2833 goto do_HV_helem;
2834
2835 case MDEREF_HV_pop_rv2hv_helem: /* expr->{...} */
2836 {
2837 dSP;
2838 sv = POPs;
2839 PUTBACK;
2840 goto do_HV_rv2hv_helem;
2841 }
2842
2843 case MDEREF_HV_gvsv_vivify_rv2hv_helem: /* $pkg->{...} */
2844 sv = UNOP_AUX_item_sv(++items);
2845 assert(isGV_with_GP(sv));
2846 sv = GvSVn((GV*)sv);
2847 goto do_HV_vivify_rv2hv_helem;
2848
2849 case MDEREF_HV_padsv_vivify_rv2hv_helem: /* $lex->{...} */
2850 sv = PAD_SVl((++items)->pad_offset);
2851 /* FALLTHROUGH */
2852
2853 do_HV_vivify_rv2hv_helem:
2854 case MDEREF_HV_vivify_rv2hv_helem: /* vivify, ->{...} */
2855 /* this is the OPpDEREF action normally found at the end of
2856 * ops like aelem, helem, rv2sv */
2857 sv = vivify_ref(sv, OPpDEREF_HV);
2858 /* FALLTHROUGH */
2859
2860 do_HV_rv2hv_helem:
2861 /* this is basically a copy of pp_rv2hv when it just has the
2862 * sKR/1 flags (and pp_rv2hv is aliased to pp_rv2av) */
2863
2864 SvGETMAGIC(sv);
2865 if (LIKELY(SvROK(sv))) {
2866 if (UNLIKELY(SvAMAGIC(sv))) {
2867 sv = amagic_deref_call(sv, to_hv_amg);
2868 }
2869 sv = SvRV(sv);
2870 if (UNLIKELY(SvTYPE(sv) != SVt_PVHV))
2871 DIE(aTHX_ "Not a HASH reference");
2872 }
2873 else if (SvTYPE(sv) != SVt_PVHV) {
2874 if (!isGV_with_GP(sv))
2875 sv = (SV*)S_softref2xv_lite(aTHX_ sv, "a HASH", SVt_PVHV);
2876 sv = MUTABLE_SV(GvHVn((GV*)sv));
2877 }
2878 /* FALLTHROUGH */
2879
2880 do_HV_helem:
2881 {
2882 /* retrieve the key; this may be either a lexical / package
2883 * var or a string constant, whose index/ptr is stored as an
2884 * item
2885 */
2886 SV *keysv = NULL; /* to shut up stupid compiler warnings */
2887
2888 assert(SvTYPE(sv) == SVt_PVHV);
2889
2890 switch (actions & MDEREF_INDEX_MASK) {
2891 case MDEREF_INDEX_none:
2892 goto finish;
2893
2894 case MDEREF_INDEX_const:
2895 keysv = UNOP_AUX_item_sv(++items);
2896 break;
2897
2898 case MDEREF_INDEX_padsv:
2899 keysv = PAD_SVl((++items)->pad_offset);
2900 break;
2901
2902 case MDEREF_INDEX_gvsv:
2903 keysv = UNOP_AUX_item_sv(++items);
2904 keysv = GvSVn((GV*)keysv);
2905 break;
2906 }
2907
2908 /* see comment above about setting this var */
2909 PL_multideref_pc = items;
2910
2911
2912 /* ensure that candidate CONSTs have been HEKified */
2913 assert( ((actions & MDEREF_INDEX_MASK) != MDEREF_INDEX_const)
2914 || SvTYPE(keysv) >= SVt_PVMG
2915 || !SvOK(keysv)
2916 || SvROK(keysv)
2917 || SvIsCOW_shared_hash(keysv));
2918
2919 /* this is basically a copy of pp_helem with OPpDEREF skipped */
2920
2921 if (!(actions & MDEREF_FLAG_last)) {
2922 HE *he = hv_fetch_ent((HV*)sv, keysv, 1, 0);
2923 if (!he || !(sv=HeVAL(he)) || sv == &PL_sv_undef)
2924 DIE(aTHX_ PL_no_helem_sv, SVfARG(keysv));
2925 break;
2926 }
2927
2928 if (PL_op->op_private &
2929 (OPpMULTIDEREF_EXISTS|OPpMULTIDEREF_DELETE))
2930 {
2931 if (PL_op->op_private & OPpMULTIDEREF_EXISTS) {
2932 sv = hv_exists_ent((HV*)sv, keysv, 0)
2933 ? &PL_sv_yes : &PL_sv_no;
2934 }
2935 else {
2936 I32 discard = (GIMME_V == G_VOID) ? G_DISCARD : 0;
2937 sv = hv_delete_ent((HV*)sv, keysv, discard, 0);
2938 if (discard)
2939 return NORMAL;
2940 if (!sv)
2941 sv = &PL_sv_undef;
2942 }
2943 }
2944 else {
2945 const U32 lval = PL_op->op_flags & OPf_MOD || LVRET;
2946 const U32 defer = PL_op->op_private & OPpLVAL_DEFER;
2947 const bool localizing = PL_op->op_private & OPpLVAL_INTRO;
2948 bool preeminent = TRUE;
2949 SV **svp;
2950 HV * const hv = (HV*)sv;
2951 HE* he;
2952
2953 if (UNLIKELY(localizing)) {
2954 MAGIC *mg;
2955 HV *stash;
2956
2957 /* If we can determine whether the element exist,
2958 * Try to preserve the existenceness of a tied hash
2959 * element by using EXISTS and DELETE if possible.
2960 * Fallback to FETCH and STORE otherwise. */
2961 if (SvCANEXISTDELETE(hv))
2962 preeminent = hv_exists_ent(hv, keysv, 0);
2963 }
2964
2965 he = hv_fetch_ent(hv, keysv, lval && !defer, 0);
2966 svp = he ? &HeVAL(he) : NULL;
2967
2968
2969 if (lval) {
2970 if (!svp || !(sv = *svp) || sv == &PL_sv_undef) {
2971 SV* lv;
2972 SV* key2;
2973 if (!defer)
2974 DIE(aTHX_ PL_no_helem_sv, SVfARG(keysv));
2975 lv = sv_newmortal();
2976 sv_upgrade(lv, SVt_PVLV);
2977 LvTYPE(lv) = 'y';
2978 sv_magic(lv, key2 = newSVsv(keysv),
2979 PERL_MAGIC_defelem, NULL, 0);
2980 /* sv_magic() increments refcount */
2981 SvREFCNT_dec_NN(key2);
0ad694a7 2982 LvTARG(lv) = SvREFCNT_inc_simple_NN(hv);
fedf30e1
DM
2983 LvTARGLEN(lv) = 1;
2984 sv = lv;
2985 }
2986 else {
2987 if (localizing) {
2988 if (HvNAME_get(hv) && isGV(sv))
2989 save_gp(MUTABLE_GV(sv),
2990 !(PL_op->op_flags & OPf_SPECIAL));
2991 else if (preeminent) {
2992 save_helem_flags(hv, keysv, svp,
2993 (PL_op->op_flags & OPf_SPECIAL)
2994 ? 0 : SAVEf_SETMAGIC);
2995 sv = *svp; /* may have changed */
2996 }
2997 else
2998 SAVEHDELETE(hv, keysv);
2999 }
3000 }
3001 }
3002 else {
3003 sv = (svp && *svp ? *svp : &PL_sv_undef);
3004 /* see note in pp_helem() */
3005 if (SvRMAGICAL(hv) && SvGMAGICAL(sv))
3006 mg_get(sv);
3007 }
3008 }
3009 goto finish;
3010 }
3011
3012 } /* switch */
3013
3014 actions >>= MDEREF_SHIFT;
3015 } /* while */
3016 /* NOTREACHED */
3017}
3018
3019
a0d0e21e
LW
3020PP(pp_iter)
3021{
eb578fdb 3022 PERL_CONTEXT *cx;
7d6c2cef 3023 SV *oldsv;
1d7c1841 3024 SV **itersvp;
a0d0e21e 3025
84f05d57
JH
3026 SV *sv;
3027 AV *av;
3028 IV ix;
3029 IV inc;
3030
4ebe6e95 3031 cx = CX_CUR();
1d7c1841 3032 itersvp = CxITERVAR(cx);
4b5c941e 3033 assert(itersvp);
a48ce6be
DM
3034
3035 switch (CxTYPE(cx)) {
17c91640 3036
b552b52c
DM
3037 case CXt_LOOP_LAZYSV: /* string increment */
3038 {
3039 SV* cur = cx->blk_loop.state_u.lazysv.cur;
3040 SV *end = cx->blk_loop.state_u.lazysv.end;
3041 /* If the maximum is !SvOK(), pp_enteriter substitutes PL_sv_no.
3042 It has SvPVX of "" and SvCUR of 0, which is what we want. */
3043 STRLEN maxlen = 0;
3044 const char *max = SvPV_const(end, maxlen);
d6c970c7
AC
3045 if (DO_UTF8(end) && IN_UNI_8_BIT)
3046 maxlen = sv_len_utf8_nomg(end);
5d9574c1 3047 if (UNLIKELY(SvNIOK(cur) || SvCUR(cur) > maxlen))
8a1f10dd 3048 goto retno;
b552b52c
DM
3049
3050 oldsv = *itersvp;
6d3ca00e
DM
3051 /* NB: on the first iteration, oldsv will have a ref count of at
3052 * least 2 (one extra from blk_loop.itersave), so the GV or pad
3053 * slot will get localised; on subsequent iterations the RC==1
3054 * optimisation may kick in and the SV will be reused. */
3055 if (oldsv && LIKELY(SvREFCNT(oldsv) == 1 && !SvMAGICAL(oldsv))) {
b552b52c
DM
3056 /* safe to reuse old SV */
3057 sv_setsv(oldsv, cur);
a48ce6be 3058 }
b552b52c
DM
3059 else
3060 {
3061 /* we need a fresh SV every time so that loop body sees a
3062 * completely new SV for closures/references to work as
3063 * they used to */
3064 *itersvp = newSVsv(cur);
6d3ca00e 3065 SvREFCNT_dec(oldsv);
b552b52c
DM
3066 }
3067 if (strEQ(SvPVX_const(cur), max))
3068 sv_setiv(cur, 0); /* terminate next time */
3069 else
3070 sv_inc(cur);
3071 break;
3072 }
a48ce6be 3073
fcef60b4
DM
3074 case CXt_LOOP_LAZYIV: /* integer increment */
3075 {
3076 IV cur = cx->blk_loop.state_u.lazyiv.cur;
5d9574c1 3077 if (UNLIKELY(cur > cx->blk_loop.state_u.lazyiv.end))
8a1f10dd 3078 goto retno;
7f61b687 3079
fcef60b4 3080 oldsv = *itersvp;
6d3ca00e
DM
3081 /* see NB comment above */
3082 if (oldsv && LIKELY(SvREFCNT(oldsv) == 1 && !SvMAGICAL(oldsv))) {
eaa5c2d6 3083 /* safe to reuse old SV */
47b96a1e
DM
3084
3085 if ( (SvFLAGS(oldsv) & (SVTYPEMASK|SVf_THINKFIRST|SVf_IVisUV))
3086 == SVt_IV)
3087 {
3088 /* Cheap SvIOK_only().
3089 * Assert that flags which SvIOK_only() would test or
3090 * clear can't be set, because we're SVt_IV */
3091 assert(!(SvFLAGS(oldsv) &
3092 (SVf_OOK|SVf_UTF8|(SVf_OK & ~(SVf_IOK|SVp_IOK)))));
3093 SvFLAGS(oldsv) |= (SVf_IOK|SVp_IOK);
3094 /* SvIV_set() where sv_any points to head */
3095 oldsv->sv_u.svu_iv = cur;
3096
3097 }
3098 else
3099 sv_setiv(oldsv, cur);
eaa5c2d6 3100 }
1c846c1f 3101 else
eaa5c2d6
GA
3102 {
3103 /* we need a fresh SV every time so that loop body sees a
3104 * completely new SV for closures/references to work as they
3105 * used to */
fcef60b4 3106 *itersvp = newSViv(cur);
6d3ca00e 3107 SvREFCNT_dec(oldsv);
eaa5c2d6 3108 }
a2309040 3109
5d9574c1 3110 if (UNLIKELY(cur == IV_MAX)) {
cdc1aa42
NC
3111 /* Handle end of range at IV_MAX */
3112 cx->blk_loop.state_u.lazyiv.end = IV_MIN;
3113 } else
3114 ++cx->blk_loop.state_u.lazyiv.cur;
a48ce6be 3115 break;
fcef60b4 3116 }
a48ce6be 3117
93661e56
DM
3118 case CXt_LOOP_LIST: /* for (1,2,3) */
3119
3120 assert(OPpITER_REVERSED == 2); /* so inc becomes -1 or 1 */
3121 inc = 1 - (PL_op->op_private & OPpITER_REVERSED);
3122 ix = (cx->blk_loop.state_u.stack.ix += inc);
3123 if (UNLIKELY(inc > 0
3124 ? ix > cx->blk_oldsp
3125 : ix <= cx->blk_loop.state_u.stack.basesp)
3126 )
8a1f10dd 3127 goto retno;
93661e56
DM
3128
3129 sv = PL_stack_base[ix];
3130 av = NULL;
3131 goto loop_ary_common;
3132
3133 case CXt_LOOP_ARY: /* for (@ary) */
3134
3135 av = cx->blk_loop.state_u.ary.ary;
3136 inc = 1 - (PL_op->op_private & OPpITER_REVERSED);
3137 ix = (cx->blk_loop.state_u.ary.ix += inc);
3138 if (UNLIKELY(inc > 0
3139 ? ix > AvFILL(av)
3140 : ix < 0)
3141 )
8a1f10dd 3142 goto retno;
de080daa 3143
9d1ee8e0 3144 if (UNLIKELY(SvRMAGICAL(av))) {
a8a20bb6
DM
3145 SV * const * const svp = av_fetch(av, ix, FALSE);
3146 sv = svp ? *svp : NULL;
3147 }
3148 else {
3149 sv = AvARRAY(av)[ix];
de080daa 3150 }
ef3e5ea9 3151
93661e56
DM
3152 loop_ary_common:
3153
d39c26a6
FC
3154 if (UNLIKELY(cx->cx_type & CXp_FOR_LVREF)) {
3155 SvSetMagicSV(*itersvp, sv);
3156 break;
3157 }
3158
5d9574c1
DM
3159 if (LIKELY(sv)) {
3160 if (UNLIKELY(SvIS_FREED(sv))) {
f38aa882
DM
3161 *itersvp = NULL;
3162 Perl_croak(aTHX_ "Use of freed value in iteration");
3163 }
60779a30 3164 if (SvPADTMP(sv)) {
8e079c2a 3165 sv = newSVsv(sv);
60779a30 3166 }
8e079c2a
FC
3167 else {
3168 SvTEMP_off(sv);
3169 SvREFCNT_inc_simple_void_NN(sv);
3170 }
de080daa 3171 }
93661e56 3172 else if (av) {
199f858d 3173 sv = newSVavdefelem(av, ix, 0);
de080daa 3174 }
a600f7e6
FC
3175 else
3176 sv = &PL_sv_undef;
a0d0e21e 3177
de080daa
DM
3178 oldsv = *itersvp;
3179 *itersvp = sv;
3180 SvREFCNT_dec(oldsv);
de080daa 3181 break;
a48ce6be
DM
3182
3183 default:
3184 DIE(aTHX_ "panic: pp_iter, type=%u", CxTYPE(cx));
3185 }
8a1f10dd 3186
7c114860
DM
3187 /* Bypass pushing &PL_sv_yes and calling pp_and(); instead
3188 * jump straight to the AND op's op_other */
3189 assert(PL_op->op_next->op_type == OP_AND);
3190 assert(PL_op->op_next->op_ppaddr == Perl_pp_and);
3191 return cLOGOPx(PL_op->op_next)->op_other;
3192
3193 retno:
3194 /* Bypass pushing &PL_sv_no and calling pp_and(); instead
3195 * jump straight to the AND op's op_next */
3196 assert(PL_op->op_next->op_type == OP_AND);
3197 assert(PL_op->op_next->op_ppaddr == Perl_pp_and);
8a1f10dd 3198 /* pp_enteriter should have pre-extended the stack */
87058c31 3199 EXTEND_SKIP(PL_stack_sp, 1);
7c114860
DM
3200 /* we only need this for the rare case where the OP_AND isn't
3201 * in void context, e.g. $x = do { for (..) {...} };
3202 * but its cheaper to just push it rather than testing first
3203 */
3204 *++PL_stack_sp = &PL_sv_no;
3205 return PL_op->op_next->op_next;
a0d0e21e
LW
3206}
3207
7c114860 3208
ef07e810
DM
3209/*
3210A description of how taint works in pattern matching and substitution.
3211
284167a5
SM
3212This is all conditional on NO_TAINT_SUPPORT not being defined. Under
3213NO_TAINT_SUPPORT, taint-related operations should become no-ops.
3214
4e19c54b 3215While the pattern is being assembled/concatenated and then compiled,
284167a5
SM
3216PL_tainted will get set (via TAINT_set) if any component of the pattern
3217is tainted, e.g. /.*$tainted/. At the end of pattern compilation,
3218the RXf_TAINTED flag is set on the pattern if PL_tainted is set (via
1738e041
DM
3219TAINT_get). It will also be set if any component of the pattern matches
3220based on locale-dependent behavior.
ef07e810 3221
0ab462a6
DM
3222When the pattern is copied, e.g. $r = qr/..../, the SV holding the ref to
3223the pattern is marked as tainted. This means that subsequent usage, such
284167a5
SM
3224as /x$r/, will set PL_tainted using TAINT_set, and thus RXf_TAINTED,
3225on the new pattern too.
ef07e810 3226
272d35c9 3227RXf_TAINTED_SEEN is used post-execution by the get magic code
ef07e810
DM
3228of $1 et al to indicate whether the returned value should be tainted.
3229It is the responsibility of the caller of the pattern (i.e. pp_match,
3230pp_subst etc) to set this flag for any other circumstances where $1 needs
3231to be tainted.
3232
3233The taint behaviour of pp_subst (and pp_substcont) is quite complex.
3234
3235There are three possible sources of taint
3236 * the source string
3237 * the pattern (both compile- and run-time, RXf_TAINTED / RXf_TAINTED_SEEN)
3238 * the replacement string (or expression under /e)
3239
3240There are four destinations of taint and they are affected by the sources
3241according to the rules below:
3242
3243 * the return value (not including /r):
3244 tainted by the source string and pattern, but only for the
3245 number-of-iterations case; boolean returns aren't tainted;
3246 * the modified string (or modified copy under /r):
3247 tainted by the source string, pattern, and replacement strings;
3248 * $1 et al:
3249 tainted by the pattern, and under 'use re "taint"', by the source
3250 string too;
3251 * PL_taint - i.e. whether subsequent code (e.g. in a /e block) is tainted:
3252 should always be unset before executing subsequent code.
3253
3254The overall action of pp_subst is:
3255
3256 * at the start, set bits in rxtainted indicating the taint status of
3257 the various sources.
3258
3259 * After each pattern execution, update the SUBST_TAINT_PAT bit in
3260 rxtainted if RXf_TAINTED_SEEN has been set, to indicate that the
3261 pattern has subsequently become tainted via locale ops.
3262
3263 * If control is being passed to pp_substcont to execute a /e block,
3264 save rxtainted in the CXt_SUBST block, for future use by
3265 pp_substcont.
3266
3267 * Whenever control is being returned to perl code (either by falling
3268 off the "end" of pp_subst/pp_substcont, or by entering a /e block),
3269 use the flag bits in rxtainted to make all the appropriate types of
0ab462a6
DM
3270 destination taint visible; e.g. set RXf_TAINTED_SEEN so that $1
3271 et al will appear tainted.
ef07e810
DM
3272
3273pp_match is just a simpler version of the above.
3274
3275*/
3276
a0d0e21e
LW
3277PP(pp_subst)
3278{
20b7effb 3279 dSP; dTARG;
eb578fdb 3280 PMOP *pm = cPMOP;
a0d0e21e 3281 PMOP *rpm = pm;
eb578fdb 3282 char *s;
a0d0e21e 3283 char *strend;
5c144d81 3284 const char *c;
a0d0e21e 3285 STRLEN clen;
3c6ef0a5
FC
3286 SSize_t iters = 0;
3287 SSize_t maxiters;
a0d0e21e 3288 bool once;
ef07e810
DM
3289 U8 rxtainted = 0; /* holds various SUBST_TAINT_* flag bits.
3290 See "how taint works" above */
a0d0e21e 3291 char *orig;
1ed74d04 3292 U8 r_flags;
eb578fdb 3293 REGEXP *rx = PM_GETRE(pm);
196a02af 3294 regexp *prog = ReANY(rx);
a0d0e21e
LW
3295 STRLEN len;
3296 int force_on_match = 0;
0bcc34c2 3297 const I32 oldsave = PL_savestack_ix;
792b2c16 3298 STRLEN slen;
26a74523 3299 bool doutf8 = FALSE; /* whether replacement is in utf8 */
db2c6cb3 3300#ifdef PERL_ANY_COW
106d9a13 3301 bool was_cow;
ed252734 3302#endif
a0714e2c 3303 SV *nsv = NULL;
b770e143 3304 /* known replacement string? */
eb578fdb 3305 SV *dstr = (pm->op_pmflags & PMf_CONST) ? POPs : NULL;
a0d0e21e 3306
f410a211
NC
3307 PERL_ASYNC_CHECK();
3308
533c011a 3309 if (PL_op->op_flags & OPf_STACKED)
a0d0e21e
LW
3310 TARG = POPs;
3311 else {
9399c607
DM
3312 if (ARGTARG)
3313 GETTARGET;
3314 else {
3315 TARG = DEFSV;
3316 }
a0d0e21e 3317 EXTEND(SP,1);
1c846c1f 3318 }
d9f424b2 3319
64534138 3320 SvGETMAGIC(TARG); /* must come before cow check */
db2c6cb3 3321#ifdef PERL_ANY_COW
106d9a13
DM
3322 /* note that a string might get converted to COW during matching */
3323 was_cow = cBOOL(SvIsCOW(TARG));
ed252734 3324#endif
d13a5d3b
TC
3325 if (!(rpm->op_pmflags & PMf_NONDESTRUCT)) {
3326#ifndef PERL_ANY_COW
3327 if (SvIsCOW(TARG))
3328 sv_force_normal_flags(TARG,0);
3329#endif
3330 if ((SvREADONLY(TARG)
3331 || ( ((SvTYPE(TARG) == SVt_PVGV && isGV_with_GP(TARG))
3332 || SvTYPE(TARG) > SVt_PVLV)
3333 && !(SvTYPE(TARG) == SVt_PVGV && SvFAKE(TARG)))))
3334 Perl_croak_no_modify();
3335 }
8ec5e241
NIS
3336 PUTBACK;
3337
6ac6605d
DM
3338 orig = SvPV_nomg(TARG, len);
3339 /* note we don't (yet) force the var into being a string; if we fail
92711104 3340 * to match, we leave as-is; on successful match however, we *will*
6ac6605d 3341 * coerce into a string, then repeat the match */
4499db73 3342 if (!SvPOKp(TARG) || SvTYPE(TARG) == SVt_PVGV || SvVOK(TARG))
a0d0e21e 3343 force_on_match = 1;
20be6587
DM
3344
3345 /* only replace once? */
3346 once = !(rpm->op_pmflags & PMf_GLOBAL);
3347
ef07e810 3348 /* See "how taint works" above */
284167a5 3349 if (TAINTING_get) {
20be6587
DM
3350 rxtainted = (
3351 (SvTAINTED(TARG) ? SUBST_TAINT_STR : 0)
196a02af 3352 | (RXp_ISTAINTED(prog) ? SUBST_TAINT_PAT : 0)
20be6587
DM
3353 | ((pm->op_pmflags & PMf_RETAINT) ? SUBST_TAINT_RETAINT : 0)
3354 | ((once && !(rpm->op_pmflags & PMf_NONDESTRUCT))
3355 ? SUBST_TAINT_BOOLRET : 0));
3356 TAINT_NOT;
3357 }
a12c0f56 3358
a0d0e21e 3359 force_it:
6ac6605d
DM
3360 if (!pm || !orig)
3361 DIE(aTHX_ "panic: pp_subst, pm=%p, orig=%p", pm, orig);
a0d0e21e 3362
6ac6605d
DM
3363 strend = orig + len;
3364 slen = DO_UTF8(TARG) ? utf8_length((U8*)orig, (U8*)strend) : len;
792b2c16
JH
3365 maxiters = 2 * slen + 10; /* We can match twice at each
3366 position, once with zero-length,
3367 second time with non-zero. */
a0d0e21e 3368
794826f4 3369 /* handle the empty pattern */
196a02af 3370 if (!RX_PRELEN(rx) && PL_curpm && !prog->mother_re) {
5585e758
YO
3371 if (PL_curpm == PL_reg_curpm) {
3372 if (PL_curpm_under) {
3373 if (PL_curpm_under == PL_reg_curpm) {
3374 Perl_croak(aTHX_ "Infinite recursion via empty pattern");
3375 } else {
3376 pm = PL_curpm_under;
3377 }
3378 }
3379 } else {
3380 pm = PL_curpm;
3381 }
3382 rx = PM_GETRE(pm);
196a02af 3383 prog = ReANY(rx);
a0d0e21e 3384 }
6502e081 3385
6e240d0b 3386#ifdef PERL_SAWAMPERSAND
196a02af 3387 r_flags = ( RXp_NPARENS(prog)
6502e081 3388 || PL_sawampersand
196a02af 3389 || (RXp_EXTFLAGS(prog) & (RXf_EVAL_SEEN|RXf_PMf_KEEPCOPY))
5b0e71e9 3390 || (rpm->op_pmflags & PMf_KEEPCOPY)
6502e081
DM
3391 )
3392 ? REXEC_COPY_STR
3393 : 0;
6e240d0b
FC
3394#else
3395 r_flags = REXEC_COPY_STR;
3396#endif
7fba1cd6 3397
0395280b 3398 if (!CALLREGEXEC(rx, orig, strend, orig, 0, TARG, NULL, r_flags))
8b64c330 3399 {
5e79dfb9
DM
3400 SPAGAIN;
3401 PUSHs(rpm->op_pmflags & PMf_NONDESTRUCT ? TARG : &PL_sv_no);
3402 LEAVE_SCOPE(oldsave);
3403 RETURN;
3404 }
1754320d
FC
3405 PL_curpm = pm;
3406
71be2cbc 3407 /* known replacement string? */
f272994b 3408 if (dstr) {
8514a05a
JH
3409 /* replacement needing upgrading? */
3410 if (DO_UTF8(TARG) && !doutf8) {
db79b45b 3411 nsv = sv_newmortal();
4a176938 3412 SvSetSV(nsv, dstr);
8df0e7a2 3413 sv_utf8_upgrade(nsv);
5c144d81 3414 c = SvPV_const(nsv, clen);
4a176938
JH
3415 doutf8 = TRUE;
3416 }
3417 else {
5c144d81 3418 c = SvPV_const(dstr, clen);
4a176938 3419 doutf8 = DO_UTF8(dstr);
8514a05a 3420 }
bb933b9b
FC
3421
3422 if (SvTAINTED(dstr))
3423 rxtainted |= SUBST_TAINT_REPL;
f272994b
A
3424 }
3425 else {
6136c704 3426 c = NULL;
f272994b
A
3427 doutf8 = FALSE;
3428 }
3429
71be2cbc 3430 /* can do inplace substitution? */
ed252734 3431 if (c
db2c6cb3 3432#ifdef PERL_ANY_COW
106d9a13 3433 && !was_cow
ed252734 3434#endif
196a02af 3435 && (I32)clen <= RXp_MINLENRET(prog)
9cefd268
FC
3436 && ( once
3437 || !(r_flags & REXEC_COPY_STR)
196a02af 3438 || (!SvGMAGICAL(dstr) && !(RXp_EXTFLAGS(prog) & RXf_EVAL_SEEN))
9cefd268 3439 )
196a02af 3440 && !(RXp_EXTFLAGS(prog) & RXf_NO_INPLACE_SUBST)
8ca8a454
NC
3441 && (!doutf8 || SvUTF8(TARG))
3442 && !(rpm->op_pmflags & PMf_NONDESTRUCT))
8b030b38 3443 {
ec911639 3444
db2c6cb3 3445#ifdef PERL_ANY_COW
106d9a13 3446 /* string might have got converted to COW since we set was_cow */
ed252734 3447 if (SvIsCOW(TARG)) {
f7a8268c 3448 if (!force_on_match)
ed252734 3449 goto have_a_cow;
f7a8268c 3450 assert(SvVOK(TARG));
ed252734
NC
3451 }
3452#endif
71be2cbc 3453 if (force_on_match) {
6ac6605d
DM
3454 /* redo the first match, this time with the orig var
3455 * forced into being a string */
71be2cbc 3456 force_on_match = 0;
6ac6605d 3457 orig = SvPV_force_nomg(TARG, len);
71be2cbc
PP
3458 goto force_it;
3459 }
39b40493 3460
71be2cbc 3461 if (once) {
c67ab8f2 3462 char *d, *m;
196a02af 3463 if (RXp_MATCH_TAINTED(prog)) /* run time pattern taint, eg locale */
20be6587 3464 rxtainted |= SUBST_TAINT_PAT;
196a02af
DM
3465 m = orig + RXp_OFFS(prog)[0].start;
3466 d = orig + RXp_OFFS(prog)[0].end;
71be2cbc
PP
3467 s = orig;
3468 if (m - s > strend - d) { /* faster to shorten from end */
2ec7214c 3469 I32 i;
71be2cbc
PP
3470 if (clen) {
3471 Copy(c, m, clen, char);
3472 m += clen;
a0d0e21e 3473 }
71be2cbc
PP
3474 i = strend - d;
3475 if (i > 0) {
3476 Move(d, m, i, char);
3477 m += i;
a0d0e21e 3478 }
71be2cbc
PP
3479 *m = '\0';
3480 SvCUR_set(TARG, m - s);
3481 }
2ec7214c
DM
3482 else { /* faster from front */
3483 I32 i = m - s;
71be2cbc 3484 d -= clen;
2ec7214c
DM
3485 if (i > 0)
3486 Move(s, d - i, i, char);
71be2cbc 3487 sv_chop(TARG, d-i);
71be2cbc 3488 if (clen)
c947cd8d 3489 Copy(c, d, clen, char);
71be2cbc 3490 }
8ec5e241 3491 SPAGAIN;
8ca8a454 3492 PUSHs(&PL_sv_yes);
71be2cbc
PP
3493 }
3494 else {
c67ab8f2 3495 char *d, *m;
196a02af 3496 d = s = RXp_OFFS(prog)[0].start + orig;
71be2cbc 3497 do {
2b25edcf 3498 I32 i;
5d9574c1 3499 if (UNLIKELY(iters++ > maxiters))
cea2e8a9 3500 DIE(aTHX_ "Substitution loop");
196a02af
DM
3501 /* run time pattern taint, eg locale */
3502 if (UNLIKELY(RXp_MATCH_TAINTED(prog)))
20be6587 3503 rxtainted |= SUBST_TAINT_PAT;
196a02af 3504 m = RXp_OFFS(prog)[0].start + orig;
155aba94 3505 if ((i = m - s)) {
71be2cbc
PP
3506 if (s != d)
3507 Move(s, d, i, char);
3508 d += i;
a0d0e21e 3509 }
71be2cbc
PP
3510 if (clen) {
3511 Copy(c, d, clen, char);
3512 d += clen;
3513 }
196a02af 3514 s = RXp_OFFS(prog)[0].end + orig;
7ce41e5c
FC
3515 } while (CALLREGEXEC(rx, s, strend, orig,
3516 s == m, /* don't match same null twice */
f722798b 3517 TARG, NULL,
d5e7783a 3518 REXEC_NOT_FIRST|REXEC_IGNOREPOS|REXEC_FAIL_ON_UNDERFLOW));
71be2cbc 3519 if (s != d) {
2b25edcf 3520 I32 i = strend - s;
aa07b2f6 3521 SvCUR_set(TARG, d - SvPVX_const(TARG) + i);
71be2cbc 3522 Move(s, d, i+1, char); /* include the NUL */
a0d0e21e 3523 }
8ec5e241 3524 SPAGAIN;
7b394f12
DM
3525 if (PL_op->op_private & OPpTRUEBOOL)
3526 PUSHs(iters ? &PL_sv_yes : &PL_sv_zero);
3527 else
3528 mPUSHi(iters);
a0d0e21e
LW
3529 }
3530 }
ff6e92e8 3531 else {
1754320d 3532 bool first;
c67ab8f2 3533 char *m;
1754320d 3534 SV *repl;
a0d0e21e 3535 if (force_on_match) {
6ac6605d
DM
3536 /* redo the first match, this time with the orig var
3537 * forced into being a string */
a0d0e21e 3538 force_on_match = 0;
0c1438a1
NC
3539 if (rpm->op_pmflags & PMf_NONDESTRUCT) {
3540 /* I feel that it should be possible to avoid this mortal copy
3541 given that the code below copies into a new destination.
3542 However, I suspect it isn't worth the complexity of
3543 unravelling the C<goto force_it> for the small number of
3544 cases where it would be viable to drop into the copy code. */
3545 TARG = sv_2mortal(newSVsv(TARG));
3546 }
6ac6605d 3547 orig = SvPV_force_nomg(TARG, len);
a0d0e21e
LW
3548 goto force_it;
3549 }
db2c6cb3 3550#ifdef PERL_ANY_COW
ed252734
NC
3551 have_a_cow:
3552#endif
196a02af 3553 if (RXp_MATCH_TAINTED(prog)) /* run time pattern taint, eg locale */
20be6587 3554 rxtainted |= SUBST_TAINT_PAT;
1754320d 3555 repl = dstr;
196a02af 3556 s = RXp_OFFS(prog)[0].start + orig;
0395280b
DM
3557 dstr = newSVpvn_flags(orig, s-orig,
3558 SVs_TEMP | (DO_UTF8(TARG) ? SVf_UTF8 : 0));
a0d0e21e 3559 if (!c) {
eb578fdb 3560 PERL_CONTEXT *cx;
8ec5e241 3561 SPAGAIN;
0395280b 3562 m = orig;
20be6587
DM
3563 /* note that a whole bunch of local vars are saved here for
3564 * use by pp_substcont: here's a list of them in case you're
3565 * searching for places in this sub that uses a particular var:
3566 * iters maxiters r_flags oldsave rxtainted orig dstr targ
3567 * s m strend rx once */
490576d1 3568 CX_PUSHSUBST(cx);
20e98b0f 3569 RETURNOP(cPMOP->op_pmreplrootu.op_pmreplroot);
a0d0e21e 3570 }
1754320d 3571 first = TRUE;
a0d0e21e 3572 do {
5d9574c1 3573 if (UNLIKELY(iters++ > maxiters))
cea2e8a9 3574 DIE(aTHX_ "Substitution loop");
196a02af 3575 if (UNLIKELY(RXp_MATCH_TAINTED(prog)))
20be6587 3576 rxtainted |= SUBST_TAINT_PAT;
196a02af 3577 if (RXp_MATCH_COPIED(prog) && RXp_SUBBEG(prog) != orig) {
c67ab8f2
DM
3578 char *old_s = s;
3579 char *old_orig = orig;
196a02af 3580 assert(RXp_SUBOFFSET(prog) == 0);
c67ab8f2 3581
196a02af 3582 orig = RXp_SUBBEG(prog);
c67ab8f2
DM
3583 s = orig + (old_s - old_orig);
3584 strend = s + (strend - old_s);
a0d0e21e 3585 }
196a02af 3586 m = RXp_OFFS(prog)[0].start + orig;
64534138 3587 sv_catpvn_nomg_maybeutf8(dstr, s, m - s, DO_UTF8(TARG));
196a02af 3588 s = RXp_OFFS(prog)[0].end + orig;
1754320d
FC
3589 if (first) {
3590 /* replacement already stringified */
3591 if (clen)
64534138 3592 sv_catpvn_nomg_maybeutf8(dstr, c, clen, doutf8);
1754320d
FC
3593 first = FALSE;
3594 }
3595 else {
8df0e7a2 3596 sv_catsv(dstr, repl);
5d9574c1 3597 if (UNLIKELY(SvTAINTED(repl)))
bb933b9b 3598 rxtainted |= SUBST_TAINT_REPL;
1754320d 3599 }
a0d0e21e
LW
3600 if (once)
3601 break;
ff27773b
KW
3602 } while (CALLREGEXEC(rx, s, strend, orig,
3603 s == m, /* Yields minend of 0 or 1 */
d5e7783a
DM
3604 TARG, NULL,
3605 REXEC_NOT_FIRST|REXEC_IGNOREPOS|REXEC_FAIL_ON_UNDERFLOW));
aba224f7 3606 assert(strend >= s);
64534138 3607 sv_catpvn_nomg_maybeutf8(dstr, s, strend - s, DO_UTF8(TARG));
748a9306 3608
8ca8a454
NC
3609 if (rpm->op_pmflags & PMf_NONDESTRUCT) {
3610 /* From here on down we're using the copy, and leaving the original
3611 untouched. */
3612 TARG = dstr;
3613 SPAGAIN;
3614 PUSHs(dstr);
3615 } else {
db2c6cb3 3616#ifdef PERL_ANY_COW
8ca8a454
NC
3617 /* The match may make the string COW. If so, brilliant, because
3618 that's just saved us one malloc, copy and free - the regexp has
3619 donated the old buffer, and we malloc an entirely new one, rather
3620 than the regexp malloc()ing a buffer and copying our original,
3621 only for us to throw it away here during the substitution. */
3622 if (SvIsCOW(TARG)) {
3623 sv_force_normal_flags(TARG, SV_COW_DROP_PV);
3624 } else
ed252734 3625#endif
8ca8a454
NC
3626 {
3627 SvPV_free(TARG);
3628 }
3629 SvPV_set(TARG, SvPVX(dstr));
3630 SvCUR_set(TARG, SvCUR(dstr));
3631 SvLEN_set(TARG, SvLEN(dstr));
64534138 3632 SvFLAGS(TARG) |= SvUTF8(dstr);
8ca8a454 3633 SvPV_set(dstr, NULL);
748a9306 3634
8ca8a454 3635 SPAGAIN;
3c6ef0a5 3636 mPUSHi(iters);
8ca8a454
NC
3637 }
3638 }
3639
3640 if (!(rpm->op_pmflags & PMf_NONDESTRUCT)) {
3641 (void)SvPOK_only_UTF8(TARG);
a0d0e21e 3642 }
20be6587 3643
ef07e810 3644 /* See "how taint works" above */
284167a5 3645 if (TAINTING_get) {
20be6587
DM
3646 if ((rxtainted & SUBST_TAINT_PAT) ||
3647 ((rxtainted & (SUBST_TAINT_STR|SUBST_TAINT_RETAINT)) ==
3648 (SUBST_TAINT_STR|SUBST_TAINT_RETAINT))
3649 )
196a02af 3650 (RXp_MATCH_TAINTED_on(prog)); /* taint $1 et al */
20be6587
DM
3651
3652 if (!(rxtainted & SUBST_TAINT_BOOLRET)
3653 && (rxtainted & (SUBST_TAINT_STR|SUBST_TAINT_PAT))
3654 )
3655 SvTAINTED_on(TOPs); /* taint return value */
3656 else
3657 SvTAINTED_off(TOPs); /* may have got tainted earlier */
3658
3659 /* needed for mg_set below */
284167a5
SM
3660 TAINT_set(
3661 cBOOL(rxtainted & (SUBST_TAINT_STR|SUBST_TAINT_PAT|SUBST_TAINT_REPL))
3662 );
20be6587
DM
3663 SvTAINT(TARG);
3664 }
3665 SvSETMAGIC(TARG); /* PL_tainted must be correctly set for this mg_set */
3666 TAINT_NOT;
f1a76097
DM
3667