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change sv_setsv(sv,NULL) to sv_set_undef(sv)
[perl5.git] / pp_hot.c
CommitLineData
a0d0e21e
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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));
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LW
65 RETURN;
66}
67
b1c05ba5
DM
68
69/* also used for: pp_lineseq() pp_regcmaybe() pp_scalar() pp_scope() */
70
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LW
71PP(pp_null)
72{
73 return NORMAL;
74}
75
3dd9d4e4
FC
76/* This is sometimes called directly by pp_coreargs, pp_grepstart and
77 amagic_call. */
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LW
78PP(pp_pushmark)
79{
3280af22 80 PUSHMARK(PL_stack_sp);
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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));
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LW
99 RETURN;
100}
101
b1c05ba5
DM
102
103/* also used for: pp_andassign() */
104
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LW
105PP(pp_and)
106{
f410a211 107 PERL_ASYNC_CHECK();
4cc783ef
DD
108 {
109 /* SP is not used to remove a variable that is saved across the
110 sv_2bool_flags call in SvTRUE_NN, if a RISC/CISC or low/high machine
111 register or load/store vs direct mem ops macro is introduced, this
112 should be a define block between direct PL_stack_sp and dSP operations,
113 presently, using PL_stack_sp is bias towards CISC cpus */
114 SV * const sv = *PL_stack_sp;
115 if (!SvTRUE_NN(sv))
116 return NORMAL;
117 else {
118 if (PL_op->op_type == OP_AND)
119 --PL_stack_sp;
120 return cLOGOP->op_other;
121 }
a0d0e21e
LW
122 }
123}
124
125PP(pp_sassign)
126{
20b7effb 127 dSP;
3e75a3c4
RU
128 /* sassign keeps its args in the optree traditionally backwards.
129 So we pop them differently.
130 */
131 SV *left = POPs; SV *right = TOPs;
748a9306 132
354eabfa 133 if (PL_op->op_private & OPpASSIGN_BACKWARDS) { /* {or,and,dor}assign */
0bd48802
AL
134 SV * const temp = left;
135 left = right; right = temp;
a0d0e21e 136 }
d48c660d
DM
137 assert(TAINTING_get || !TAINT_get);
138 if (UNLIKELY(TAINT_get) && !SvTAINTED(right))
a0d0e21e 139 TAINT_NOT;
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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;
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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
DM
968
969/* also used for: pp_rv2hv() */
bdaf10a5 970/* also called directly by pp_lvavref */
b1c05ba5 971
a0d0e21e
LW
972PP(pp_rv2av)
973{
20b7effb 974 dSP; dTOPss;
1c23e2bd 975 const U8 gimme = GIMME_V;
13c59d41
MH
976 static const char an_array[] = "an ARRAY";
977 static const char a_hash[] = "a HASH";
bdaf10a5
FC
978 const bool is_pp_rv2av = PL_op->op_type == OP_RV2AV
979 || PL_op->op_type == OP_LVAVREF;
d83b45b8 980 const svtype type = is_pp_rv2av ? SVt_PVAV : SVt_PVHV;
a0d0e21e 981
9026059d 982 SvGETMAGIC(sv);
a0d0e21e 983 if (SvROK(sv)) {
5d9574c1 984 if (UNLIKELY(SvAMAGIC(sv))) {
93d7320b 985 sv = amagic_deref_call(sv, is_pp_rv2av ? to_av_amg : to_hv_amg);
93d7320b 986 }
17ab7946 987 sv = SvRV(sv);
5d9574c1 988 if (UNLIKELY(SvTYPE(sv) != type))
dcbac5bb 989 /* diag_listed_as: Not an ARRAY reference */
13c59d41 990 DIE(aTHX_ "Not %s reference", is_pp_rv2av ? an_array : a_hash);
5d9574c1
DM
991 else if (UNLIKELY(PL_op->op_flags & OPf_MOD
992 && PL_op->op_private & OPpLVAL_INTRO))
3da99855 993 Perl_croak(aTHX_ "%s", PL_no_localize_ref);
a0d0e21e 994 }
5d9574c1 995 else if (UNLIKELY(SvTYPE(sv) != type)) {
67955e0c 996 GV *gv;
1c846c1f 997
6e592b3a 998 if (!isGV_with_GP(sv)) {
13c59d41 999 gv = Perl_softref2xv(aTHX_ sv, is_pp_rv2av ? an_array : a_hash,
dc3c76f8
NC
1000 type, &sp);
1001 if (!gv)
1002 RETURN;
35cd451c
GS
1003 }
1004 else {
159b6efe 1005 gv = MUTABLE_GV(sv);
a0d0e21e 1006 }
ad64d0ec 1007 sv = is_pp_rv2av ? MUTABLE_SV(GvAVn(gv)) : MUTABLE_SV(GvHVn(gv));
533c011a 1008 if (PL_op->op_private & OPpLVAL_INTRO)
ad64d0ec 1009 sv = is_pp_rv2av ? MUTABLE_SV(save_ary(gv)) : MUTABLE_SV(save_hash(gv));
9f527363
FC
1010 }
1011 if (PL_op->op_flags & OPf_REF) {
17ab7946 1012 SETs(sv);
a0d0e21e 1013 RETURN;
9f527363 1014 }
5d9574c1 1015 else if (UNLIKELY(PL_op->op_private & OPpMAYBE_LVSUB)) {
40c94d11
FC
1016 const I32 flags = is_lvalue_sub();
1017 if (flags && !(flags & OPpENTERSUB_INARGS)) {
cde874ca 1018 if (gimme != G_ARRAY)
042560a6 1019 goto croak_cant_return;
17ab7946 1020 SETs(sv);
78f9721b 1021 RETURN;
40c94d11 1022 }
a0d0e21e
LW
1023 }
1024
17ab7946 1025 if (is_pp_rv2av) {
502c6561 1026 AV *const av = MUTABLE_AV(sv);
636fe681 1027 /* The guts of pp_rv2av */
96913b52 1028 if (gimme == G_ARRAY) {
d5524600
DM
1029 SP--;
1030 PUTBACK;
1031 S_pushav(aTHX_ av);
1032 SPAGAIN;
1c846c1f 1033 }
96913b52 1034 else if (gimme == G_SCALAR) {
c70927a6 1035 const SSize_t maxarg = AvFILL(av) + 1;
7be75ccf
DM
1036 if (PL_op->op_private & OPpTRUEBOOL)
1037 SETs(maxarg ? &PL_sv_yes : &PL_sv_zero);
1038 else {
1039 dTARGET;
1040 SETi(maxarg);
1041 }
93965878 1042 }
7be75ccf
DM
1043 }
1044 else {
748f2c65 1045 bool tied;
17ab7946 1046 /* The guts of pp_rv2hv */
96913b52
VP
1047 if (gimme == G_ARRAY) { /* array wanted */
1048 *PL_stack_sp = sv;
981b7185 1049 return Perl_do_kv(aTHX);
96913b52 1050 }
748f2c65
DM
1051
1052 if (PL_op->op_private & OPpRV2HV_ISKEYS)
1053 /* 'keys %h' masquerading as '%h': reset iterator */
1054 (void)hv_iterinit(MUTABLE_HV(sv));
1055
1056 tied = SvRMAGICAL(sv) && mg_find(sv, PERL_MAGIC_tied);
1057
1058 if ( ( PL_op->op_private & OPpTRUEBOOL
adc42c31 1059 || ( PL_op->op_private & OPpMAYBE_TRUEBOOL
748f2c65
DM
1060 && block_gimme() == G_VOID)
1061 )
1062 && !tied)
a5bf735c 1063 SETs(HvUSEDKEYS(MUTABLE_HV(sv)) ? &PL_sv_yes : &PL_sv_zero);
96913b52 1064 else if (gimme == G_SCALAR) {
1a8bdda9 1065 dTARG;
748f2c65
DM
1066 if (PL_op->op_private & OPpRV2HV_ISKEYS) {
1067 IV i;
1068 if (tied) {
1069 i = 0;
1070 while (hv_iternext(MUTABLE_HV(sv)))
1071 i++;
1072 }
1073 else
1074 i = HvUSEDKEYS(MUTABLE_HV(sv));
1075 (void)POPs;
1076 mPUSHi(i);
1077 }
1078 else {
1079 TARG = Perl_hv_scalar(aTHX_ MUTABLE_HV(sv));
1080 SETTARG;
1081 }
96913b52 1082 }
17ab7946 1083 }
be85d344 1084 RETURN;
042560a6
NC
1085
1086 croak_cant_return:
1087 Perl_croak(aTHX_ "Can't return %s to lvalue scalar context",
1088 is_pp_rv2av ? "array" : "hash");
77e217c6 1089 RETURN;
a0d0e21e
LW
1090}
1091
10c8fecd 1092STATIC void
fb8f4cf8 1093S_do_oddball(pTHX_ SV **oddkey, SV **firstkey)
10c8fecd 1094{
7918f24d
NC
1095 PERL_ARGS_ASSERT_DO_ODDBALL;
1096
fb8f4cf8 1097 if (*oddkey) {
6d822dc4 1098 if (ckWARN(WARN_MISC)) {
a3b680e6 1099 const char *err;
fb8f4cf8
RZ
1100 if (oddkey == firstkey &&
1101 SvROK(*oddkey) &&
1102 (SvTYPE(SvRV(*oddkey)) == SVt_PVAV ||
1103 SvTYPE(SvRV(*oddkey)) == SVt_PVHV))
10c8fecd 1104 {
a3b680e6 1105 err = "Reference found where even-sized list expected";
10c8fecd
GS
1106 }
1107 else
a3b680e6 1108 err = "Odd number of elements in hash assignment";
f1f66076 1109 Perl_warner(aTHX_ packWARN(WARN_MISC), "%s", err);
10c8fecd 1110 }
6d822dc4 1111
10c8fecd
GS
1112 }
1113}
1114
a5f48505
DM
1115
1116/* Do a mark and sweep with the SVf_BREAK flag to detect elements which
1117 * are common to both the LHS and RHS of an aassign, and replace them
1118 * with copies. All these copies are made before the actual list assign is
1119 * done.
1120 *
1121 * For example in ($a,$b) = ($b,$a), assigning the value of the first RHS
1122 * element ($b) to the first LH element ($a), modifies $a; when the
1123 * second assignment is done, the second RH element now has the wrong
1124 * value. So we initially replace the RHS with ($b, mortalcopy($a)).
1125 * Note that we don't need to make a mortal copy of $b.
1126 *
1127 * The algorithm below works by, for every RHS element, mark the
1128 * corresponding LHS target element with SVf_BREAK. Then if the RHS
1129 * element is found with SVf_BREAK set, it means it would have been
1130 * modified, so make a copy.
1131 * Note that by scanning both LHS and RHS in lockstep, we avoid
1132 * unnecessary copies (like $b above) compared with a naive
1133 * "mark all LHS; copy all marked RHS; unmark all LHS".
1134 *
1135 * If the LHS element is a 'my' declaration' and has a refcount of 1, then
1136 * it can't be common and can be skipped.
ebc643ce
DM
1137 *
1138 * On DEBUGGING builds it takes an extra boolean, fake. If true, it means
1139 * that we thought we didn't need to call S_aassign_copy_common(), but we
1140 * have anyway for sanity checking. If we find we need to copy, then panic.
a5f48505
DM
1141 */
1142
1143PERL_STATIC_INLINE void
1144S_aassign_copy_common(pTHX_ SV **firstlelem, SV **lastlelem,
ebc643ce
DM
1145 SV **firstrelem, SV **lastrelem
1146#ifdef DEBUGGING
1147 , bool fake
1148#endif
1149)
a5f48505
DM
1150{
1151 dVAR;
1152 SV **relem;
1153 SV **lelem;
1154 SSize_t lcount = lastlelem - firstlelem + 1;
1155 bool marked = FALSE; /* have we marked any LHS with SVf_BREAK ? */
1156 bool const do_rc1 = cBOOL(PL_op->op_private & OPpASSIGN_COMMON_RC1);
beb08a1e 1157 bool copy_all = FALSE;
a5f48505
DM
1158
1159 assert(!PL_in_clean_all); /* SVf_BREAK not already in use */
1160 assert(firstlelem < lastlelem); /* at least 2 LH elements */
1161 assert(firstrelem < lastrelem); /* at least 2 RH elements */
1162
ebc643ce
DM
1163
1164 lelem = firstlelem;
a5f48505
DM
1165 /* we never have to copy the first RH element; it can't be corrupted
1166 * by assigning something to the corresponding first LH element.
1167 * So this scan does in a loop: mark LHS[N]; test RHS[N+1]
1168 */
ebc643ce 1169 relem = firstrelem + 1;
a5f48505
DM
1170
1171 for (; relem <= lastrelem; relem++) {
1172 SV *svr;
1173
1174 /* mark next LH element */
1175
1176 if (--lcount >= 0) {
1177 SV *svl = *lelem++;
1178
1179 if (UNLIKELY(!svl)) {/* skip AV alias marker */
1180 assert (lelem <= lastlelem);
1181 svl = *lelem++;
1182 lcount--;
1183 }
1184
1185 assert(svl);
beb08a1e
TC
1186 if (SvSMAGICAL(svl)) {
1187 copy_all = TRUE;
1188 }
a5f48505
DM
1189 if (SvTYPE(svl) == SVt_PVAV || SvTYPE(svl) == SVt_PVHV) {
1190 if (!marked)
1191 return;
1192 /* this LH element will consume all further args;
1193 * no need to mark any further LH elements (if any).
1194 * But we still need to scan any remaining RHS elements;
1195 * set lcount negative to distinguish from lcount == 0,
1196 * so the loop condition continues being true
1197 */
1198 lcount = -1;
1199 lelem--; /* no need to unmark this element */
1200 }
94a5f659 1201 else if (!(do_rc1 && SvREFCNT(svl) == 1) && !SvIMMORTAL(svl)) {
a5f48505
DM
1202 SvFLAGS(svl) |= SVf_BREAK;
1203 marked = TRUE;
1204 }
1205 else if (!marked) {
1206 /* don't check RH element if no SVf_BREAK flags set yet */
1207 if (!lcount)
1208 break;
1209 continue;
1210 }
1211 }
1212
1213 /* see if corresponding RH element needs copying */
1214
1215 assert(marked);
1216 svr = *relem;
1217 assert(svr);
1218
5c1db569 1219 if (UNLIKELY(SvFLAGS(svr) & (SVf_BREAK|SVs_GMG) || copy_all)) {
1050723f 1220 U32 brk = (SvFLAGS(svr) & SVf_BREAK);
a5f48505 1221
ebc643ce
DM
1222#ifdef DEBUGGING
1223 if (fake) {
9ae0115f 1224 /* op_dump(PL_op); */
ebc643ce
DM
1225 Perl_croak(aTHX_
1226 "panic: aassign skipped needed copy of common RH elem %"
1227 UVuf, (UV)(relem - firstrelem));
1228 }
1229#endif
1230
a5f48505
DM
1231 TAINT_NOT; /* Each item is independent */
1232
1233 /* Dear TODO test in t/op/sort.t, I love you.
1234 (It's relying on a panic, not a "semi-panic" from newSVsv()
1235 and then an assertion failure below.) */
1236 if (UNLIKELY(SvIS_FREED(svr))) {
1237 Perl_croak(aTHX_ "panic: attempt to copy freed scalar %p",
1238 (void*)svr);
1239 }
1240 /* avoid break flag while copying; otherwise COW etc
1241 * disabled... */
1242 SvFLAGS(svr) &= ~SVf_BREAK;
1243 /* Not newSVsv(), as it does not allow copy-on-write,
8c1e192f
DM
1244 resulting in wasteful copies.
1245 Also, we use SV_NOSTEAL in case the SV is used more than
1246 once, e.g. (...) = (f())[0,0]
1247 Where the same SV appears twice on the RHS without a ref
1248 count bump. (Although I suspect that the SV won't be
1249 stealable here anyway - DAPM).
1250 */
a5f48505
DM
1251 *relem = sv_mortalcopy_flags(svr,
1252 SV_GMAGIC|SV_DO_COW_SVSETSV|SV_NOSTEAL);
1253 /* ... but restore afterwards in case it's needed again,
1254 * e.g. ($a,$b,$c) = (1,$a,$a)
1255 */
1050723f 1256 SvFLAGS(svr) |= brk;
a5f48505
DM
1257 }
1258
1259 if (!lcount)
1260 break;
1261 }
1262
1263 if (!marked)
1264 return;
1265
1266 /*unmark LHS */
1267
1268 while (lelem > firstlelem) {
1269 SV * const svl = *(--lelem);
1270 if (svl)
1271 SvFLAGS(svl) &= ~SVf_BREAK;
1272 }
1273}
1274
1275
1276
a0d0e21e
LW
1277PP(pp_aassign)
1278{
27da23d5 1279 dVAR; dSP;
3280af22
NIS
1280 SV **lastlelem = PL_stack_sp;
1281 SV **lastrelem = PL_stack_base + POPMARK;
1282 SV **firstrelem = PL_stack_base + POPMARK + 1;
a0d0e21e
LW
1283 SV **firstlelem = lastrelem + 1;
1284
eb578fdb
KW
1285 SV **relem;
1286 SV **lelem;
1c23e2bd 1287 U8 gimme;
a68090fe
DM
1288 /* PL_delaymagic is restored by JUMPENV_POP on dieing, so we
1289 * only need to save locally, not on the save stack */
1290 U16 old_delaymagic = PL_delaymagic;
ebc643ce
DM
1291#ifdef DEBUGGING
1292 bool fake = 0;
1293#endif
5637b936 1294
3280af22 1295 PL_delaymagic = DM_DELAY; /* catch simultaneous items */
a0d0e21e
LW
1296
1297 /* If there's a common identifier on both sides we have to take
1298 * special care that assigning the identifier on the left doesn't
1299 * clobber a value on the right that's used later in the list.
1300 */
acdea6f0 1301
beb08a1e
TC
1302 /* at least 2 LH and RH elements, or commonality isn't an issue */
1303 if (firstlelem < lastlelem && firstrelem < lastrelem) {
5c1db569
TC
1304 for (relem = firstrelem+1; relem <= lastrelem; relem++) {
1305 if (SvGMAGICAL(*relem))
1306 goto do_scan;
1307 }
beb08a1e
TC
1308 for (lelem = firstlelem; lelem <= lastlelem; lelem++) {
1309 if (*lelem && SvSMAGICAL(*lelem))
1310 goto do_scan;
a5f48505 1311 }
beb08a1e
TC
1312 if ( PL_op->op_private & (OPpASSIGN_COMMON_SCALAR|OPpASSIGN_COMMON_RC1) ) {
1313 if (PL_op->op_private & OPpASSIGN_COMMON_RC1) {
1314 /* skip the scan if all scalars have a ref count of 1 */
1315 for (lelem = firstlelem; lelem <= lastlelem; lelem++) {
8b0c3377 1316 SV *sv = *lelem;
beb08a1e
TC
1317 if (!sv || SvREFCNT(sv) == 1)
1318 continue;
1319 if (SvTYPE(sv) != SVt_PVAV && SvTYPE(sv) != SVt_PVAV)
1320 goto do_scan;
1321 break;
1322 }
1323 }
1324 else {
1325 do_scan:
1326 S_aassign_copy_common(aTHX_
1327 firstlelem, lastlelem, firstrelem, lastrelem
ebc643ce 1328#ifdef DEBUGGING
beb08a1e 1329 , fake
ebc643ce 1330#endif
beb08a1e
TC
1331 );
1332 }
a5f48505 1333 }
a0d0e21e 1334 }
ebc643ce
DM
1335#ifdef DEBUGGING
1336 else {
1337 /* on debugging builds, do the scan even if we've concluded we
1338 * don't need to, then panic if we find commonality. Note that the
1339 * scanner assumes at least 2 elements */
1340 if (firstlelem < lastlelem && firstrelem < lastrelem) {
1341 fake = 1;
1342 goto do_scan;
1343 }
1344 }
1345#endif
a0d0e21e 1346
a5f48505 1347 gimme = GIMME_V;
a0d0e21e
LW
1348 relem = firstrelem;
1349 lelem = firstlelem;
10c8fecd 1350
8b0c3377
DM
1351 if (relem > lastrelem)
1352 goto no_relems;
1353
1354 /* first lelem loop while there are still relems */
5d9574c1 1355 while (LIKELY(lelem <= lastlelem)) {
bdaf10a5 1356 bool alias = FALSE;
8b0c3377
DM
1357 SV *lsv = *lelem++;
1358
c73f612f
DM
1359 TAINT_NOT; /* Each item stands on its own, taintwise. */
1360
8b0c3377
DM
1361 assert(relem <= lastrelem);
1362 if (UNLIKELY(!lsv)) {
bdaf10a5 1363 alias = TRUE;
8b0c3377
DM
1364 lsv = *lelem++;
1365 ASSUME(SvTYPE(lsv) == SVt_PVAV);
bdaf10a5 1366 }
a5f48505 1367
8b0c3377
DM
1368 switch (SvTYPE(lsv)) {
1369 case SVt_PVAV: {
1370 SV **svp;
1371 SSize_t i;
1372 SSize_t tmps_base;
1373 SSize_t nelems = lastrelem - relem + 1;
b09ed995 1374 AV *ary = MUTABLE_AV(lsv);
8b0c3377
DM
1375
1376 /* Assigning to an aggregate is tricky. First there is the
1377 * issue of commonality, e.g. @a = ($a[0]). Since the
1378 * stack isn't refcounted, clearing @a prior to storing
1379 * elements will free $a[0]. Similarly with
1380 * sub FETCH { $status[$_[1]] } @status = @tied[0,1];
1381 *
1382 * The way to avoid these issues is to make the copy of each
1383 * SV (and we normally store a *copy* in the array) *before*
1384 * clearing the array. But this has a problem in that
1385 * if the code croaks during copying, the not-yet-stored copies
1386 * could leak. One way to avoid this is to make all the copies
1387 * mortal, but that's quite expensive.
1388 *
1389 * The current solution to these issues is to use a chunk
1390 * of the tmps stack as a temporary refcounted-stack. SVs
1391 * will be put on there during processing to avoid leaks,
1392 * but will be removed again before the end of this block,
1393 * so free_tmps() is never normally called. Also, the
1394 * sv_refcnt of the SVs doesn't have to be manipulated, since
1395 * the ownership of 1 reference count is transferred directly
1396 * from the tmps stack to the AV when the SV is stored.
1397 *
1398 * We disarm slots in the temps stack by storing PL_sv_undef
1399 * there: it doesn't matter if that SV's refcount is
1400 * repeatedly decremented during a croak. But usually this is
1401 * only an interim measure. By the end of this code block
1402 * we try where possible to not leave any PL_sv_undef's on the
1403 * tmps stack e.g. by shuffling newer entries down.
1404 *
1405 * There is one case where we don't copy: non-magical
1406 * SvTEMP(sv)'s with a ref count of 1. The only owner of these
1407 * is on the tmps stack, so its safe to directly steal the SV
1408 * rather than copying. This is common in things like function
1409 * returns, map etc, which all return a list of such SVs.
1410 *
1411 * Note however something like @a = (f())[0,0], where there is
1412 * a danger of the same SV being shared: this avoided because
1413 * when the SV is stored as $a[0], its ref count gets bumped,
1414 * so the RC==1 test fails and the second element is copied
1415 * instead.
1416 *
1417 * We also use one slot in the tmps stack to hold an extra
1418 * ref to the array, to ensure it doesn't get prematurely
1419 * freed. Again, this is removed before the end of this block.
1420 *
1421 * Note that OPpASSIGN_COMMON_AGG is used to flag a possible
1422 * @a = ($a[0]) case, but the current implementation uses the
1423 * same algorithm regardless, so ignores that flag. (It *is*
1424 * used in the hash branch below, however).
1425 */
1426
1427 /* Reserve slots for ary, plus the elems we're about to copy,
1428 * then protect ary and temporarily void the remaining slots
1429 * with &PL_sv_undef */
1430 EXTEND_MORTAL(nelems + 1);
1431 PL_tmps_stack[++PL_tmps_ix] = SvREFCNT_inc_simple_NN(ary);
1432 tmps_base = PL_tmps_ix + 1;
1433 for (i = 0; i < nelems; i++)
1434 PL_tmps_stack[tmps_base + i] = &PL_sv_undef;
1435 PL_tmps_ix += nelems;
1436
1437 /* Make a copy of each RHS elem and save on the tmps_stack
1438 * (or pass through where we can optimise away the copy) */
1439
1440 if (UNLIKELY(alias)) {
1441 U32 lval = (gimme == G_ARRAY)
1442 ? (PL_op->op_flags & OPf_MOD || LVRET) : 0;
a5f48505 1443 for (svp = relem; svp <= lastrelem; svp++) {
8b0c3377
DM
1444 SV *rsv = *svp;
1445
1446 SvGETMAGIC(rsv);
1447 if (!SvROK(rsv))
1448 DIE(aTHX_ "Assigned value is not a reference");
1449 if (SvTYPE(SvRV(rsv)) > SVt_PVLV)
1450 /* diag_listed_as: Assigned value is not %s reference */
1451 DIE(aTHX_
1452 "Assigned value is not a SCALAR reference");
1453 if (lval)
1454 *svp = rsv = sv_mortalcopy(rsv);
1455 /* XXX else check for weak refs? */
1456 rsv = SvREFCNT_inc_NN(SvRV(rsv));
1457 assert(tmps_base <= PL_tmps_max);
1458 PL_tmps_stack[tmps_base++] = rsv;
a5f48505 1459 }
a5f48505 1460 }
8b0c3377
DM
1461 else {
1462 for (svp = relem; svp <= lastrelem; svp++) {
1463 SV *rsv = *svp;
a5f48505 1464
8b0c3377
DM
1465 if (SvTEMP(rsv) && !SvGMAGICAL(rsv) && SvREFCNT(rsv) == 1) {
1466 /* can skip the copy */
1467 SvREFCNT_inc_simple_void_NN(rsv);
1468 SvTEMP_off(rsv);
1469 }
a5f48505 1470 else {
8b0c3377
DM
1471 SV *nsv;
1472 /* do get before newSV, in case it dies and leaks */
1473 SvGETMAGIC(rsv);
1474 nsv = newSV(0);
8c1e192f
DM
1475 /* see comment in S_aassign_copy_common about
1476 * SV_NOSTEAL */
8b0c3377
DM
1477 sv_setsv_flags(nsv, rsv,
1478 (SV_DO_COW_SVSETSV|SV_NOSTEAL));
1479 rsv = *svp = nsv;
a5f48505 1480 }
8b0c3377
DM
1481
1482 assert(tmps_base <= PL_tmps_max);
1483 PL_tmps_stack[tmps_base++] = rsv;
1484 }
1485 }
1486
1487 if (SvRMAGICAL(ary) || AvFILLp(ary) >= 0) /* may be non-empty */
1488 av_clear(ary);
1489
1490 /* store in the array, the SVs that are in the tmps stack */
1491
1492 tmps_base -= nelems;
1493
80c1439f 1494 if (SvMAGICAL(ary) || SvREADONLY(ary) || !AvREAL(ary)) {
8b0c3377
DM
1495 /* for arrays we can't cheat with, use the official API */
1496 av_extend(ary, nelems - 1);
1497 for (i = 0; i < nelems; i++) {
1498 SV **svp = &(PL_tmps_stack[tmps_base + i]);
1499 SV *rsv = *svp;
1500 /* A tied store won't take ownership of rsv, so keep
1501 * the 1 refcnt on the tmps stack; otherwise disarm
1502 * the tmps stack entry */
1503 if (av_store(ary, i, rsv))
1504 *svp = &PL_sv_undef;
1505 /* av_store() may have added set magic to rsv */;
1506 SvSETMAGIC(rsv);
1507 }
1508 /* disarm ary refcount: see comments below about leak */
1509 PL_tmps_stack[tmps_base - 1] = &PL_sv_undef;
1510 }
1511 else {
1512 /* directly access/set the guts of the AV */
1513 SSize_t fill = nelems - 1;
1514 if (fill > AvMAX(ary))
1515 av_extend_guts(ary, fill, &AvMAX(ary), &AvALLOC(ary),
1516 &AvARRAY(ary));
1517 AvFILLp(ary) = fill;
1518 Copy(&(PL_tmps_stack[tmps_base]), AvARRAY(ary), nelems, SV*);
1519 /* Quietly remove all the SVs from the tmps stack slots,
1520 * since ary has now taken ownership of the refcnt.
1521 * Also remove ary: which will now leak if we die before
1522 * the SvREFCNT_dec_NN(ary) below */
1523 if (UNLIKELY(PL_tmps_ix >= tmps_base + nelems))
1524 Move(&PL_tmps_stack[tmps_base + nelems],
1525 &PL_tmps_stack[tmps_base - 1],
1526 PL_tmps_ix - (tmps_base + nelems) + 1,
1527 SV*);
1528 PL_tmps_ix -= (nelems + 1);
1529 }
1530
5d9574c1 1531 if (UNLIKELY(PL_delaymagic & DM_ARRAY_ISA))
8b0c3377 1532 /* its assumed @ISA set magic can't die and leak ary */
ad64d0ec 1533 SvSETMAGIC(MUTABLE_SV(ary));
8b0c3377
DM
1534 SvREFCNT_dec_NN(ary);
1535
1536 relem = lastrelem + 1;
1537 goto no_relems;
a5f48505
DM
1538 }
1539
10c8fecd 1540 case SVt_PVHV: { /* normal hash */
8b0c3377
DM
1541
1542 SV **svp;
1543 bool dirty_tmps;
1544 SSize_t i;
1545 SSize_t tmps_base;
1546 SSize_t nelems = lastrelem - relem + 1;
b09ed995 1547 HV *hash = MUTABLE_HV(lsv);
8b0c3377
DM
1548
1549 if (UNLIKELY(nelems & 1)) {
1550 do_oddball(lastrelem, relem);
1551 /* we have firstlelem to reuse, it's not needed any more */
1552 *++lastrelem = &PL_sv_undef;
1553 nelems++;
1554 }
1555
1556 /* See the SVt_PVAV branch above for a long description of
1557 * how the following all works. The main difference for hashes
1558 * is that we treat keys and values separately (and have
1559 * separate loops for them): as for arrays, values are always
1560 * copied (except for the SvTEMP optimisation), since they
1561 * need to be stored in the hash; while keys are only
1562 * processed where they might get prematurely freed or
1563 * whatever. */
1564
1565 /* tmps stack slots:
1566 * * reserve a slot for the hash keepalive;
1567 * * reserve slots for the hash values we're about to copy;
1568 * * preallocate for the keys we'll possibly copy or refcount bump
1569 * later;
1570 * then protect hash and temporarily void the remaining
1571 * value slots with &PL_sv_undef */
1572 EXTEND_MORTAL(nelems + 1);
1573
1574 /* convert to number of key/value pairs */
1575 nelems >>= 1;
1576
1577 PL_tmps_stack[++PL_tmps_ix] = SvREFCNT_inc_simple_NN(hash);
1578 tmps_base = PL_tmps_ix + 1;
1579 for (i = 0; i < nelems; i++)
1580 PL_tmps_stack[tmps_base + i] = &PL_sv_undef;
1581 PL_tmps_ix += nelems;
1582
1583 /* Make a copy of each RHS hash value and save on the tmps_stack
1584 * (or pass through where we can optimise away the copy) */
1585
1586 for (svp = relem + 1; svp <= lastrelem; svp += 2) {
1587 SV *rsv = *svp;
1588
1589 if (SvTEMP(rsv) && !SvGMAGICAL(rsv) && SvREFCNT(rsv) == 1) {
1590 /* can skip the copy */
1591 SvREFCNT_inc_simple_void_NN(rsv);
1592 SvTEMP_off(rsv);
1593 }
1594 else {
1595 SV *nsv;
1596 /* do get before newSV, in case it dies and leaks */
1597 SvGETMAGIC(rsv);
1598 nsv = newSV(0);
1599 /* see comment in S_aassign_copy_common about
1600 * SV_NOSTEAL */
1601 sv_setsv_flags(nsv, rsv,
1602 (SV_DO_COW_SVSETSV|SV_NOSTEAL));
1603 rsv = *svp = nsv;
1c4ea384
RZ
1604 }
1605
8b0c3377
DM
1606 assert(tmps_base <= PL_tmps_max);
1607 PL_tmps_stack[tmps_base++] = rsv;
1608 }
1609 tmps_base -= nelems;
a5f48505 1610
a5f48505 1611
8b0c3377
DM
1612 /* possibly protect keys */
1613
1614 if (UNLIKELY(gimme == G_ARRAY)) {
1615 /* handle e.g.
1616 * @a = ((%h = ($$r, 1)), $r = "x");
1617 * $_++ for %h = (1,2,3,4);
1618 */
1619 EXTEND_MORTAL(nelems);
1620 for (svp = relem; svp <= lastrelem; svp += 2)
1621 *svp = sv_mortalcopy_flags(*svp,
1622 SV_GMAGIC|SV_DO_COW_SVSETSV|SV_NOSTEAL);
1623 }
1624 else if (PL_op->op_private & OPpASSIGN_COMMON_AGG) {
1625 /* for possible commonality, e.g.
1626 * %h = ($h{a},1)
1627 * avoid premature freeing RHS keys by mortalising
1628 * them.
1629 * For a magic element, make a copy so that its magic is
1630 * called *before* the hash is emptied (which may affect
1631 * a tied value for example).
1632 * In theory we should check for magic keys in all
1633 * cases, not just under OPpASSIGN_COMMON_AGG, but in
1634 * practice, !OPpASSIGN_COMMON_AGG implies only
1635 * constants or padtmps on the RHS.
1636 */
1637 EXTEND_MORTAL(nelems);
1638 for (svp = relem; svp <= lastrelem; svp += 2) {
1639 SV *rsv = *svp;
1640 if (UNLIKELY(SvGMAGICAL(rsv))) {
1641 SSize_t n;
a5f48505
DM
1642 *svp = sv_mortalcopy_flags(*svp,
1643 SV_GMAGIC|SV_DO_COW_SVSETSV|SV_NOSTEAL);
8b0c3377
DM
1644 /* allow other branch to continue pushing
1645 * onto tmps stack without checking each time */
1646 n = (lastrelem - relem) >> 1;
1647 EXTEND_MORTAL(n);
a5f48505 1648 }
8b0c3377
DM
1649 else
1650 PL_tmps_stack[++PL_tmps_ix] =
1651 SvREFCNT_inc_simple_NN(rsv);
a5f48505 1652 }
8b0c3377 1653 }
a5f48505 1654
8b0c3377
DM
1655 if (SvRMAGICAL(hash) || HvUSEDKEYS(hash))
1656 hv_clear(hash);
a5f48505 1657
8b0c3377
DM
1658 /* now assign the keys and values to the hash */
1659
1660 dirty_tmps = FALSE;
1661
1662 if (UNLIKELY(gimme == G_ARRAY)) {
1663 /* @a = (%h = (...)) etc */
1664 SV **svp;
1665 SV **topelem = relem;
1666
1667 for (i = 0, svp = relem; svp <= lastrelem; i++, svp++) {
1668 SV *key = *svp++;
1669 SV *val = *svp;
1670 /* remove duplicates from list we return */
1671 if (!hv_exists_ent(hash, key, 0)) {
1672 /* copy key back: possibly to an earlier
1673 * stack location if we encountered dups earlier,
1674 * The values will be updated later
1675 */
1676 *topelem = key;
1677 topelem += 2;
632b9d6f 1678 }
8b0c3377
DM
1679 /* A tied store won't take ownership of val, so keep
1680 * the 1 refcnt on the tmps stack; otherwise disarm
1681 * the tmps stack entry */
1682 if (hv_store_ent(hash, key, val, 0))
1683 PL_tmps_stack[tmps_base + i] = &PL_sv_undef;
1684 else
1685 dirty_tmps = TRUE;
1686 /* hv_store_ent() may have added set magic to val */;
1687 SvSETMAGIC(val);
1688 }
1689 if (topelem < svp) {
1c4ea384
RZ
1690 /* at this point we have removed the duplicate key/value
1691 * pairs from the stack, but the remaining values may be
1692 * wrong; i.e. with (a 1 a 2 b 3) on the stack we've removed
1693 * the (a 2), but the stack now probably contains
1694 * (a <freed> b 3), because { hv_save(a,1); hv_save(a,2) }
1695 * obliterates the earlier key. So refresh all values. */
8b0c3377
DM
1696 lastrelem = topelem - 1;
1697 while (relem < lastrelem) {
1c4ea384
RZ
1698 HE *he;
1699 he = hv_fetch_ent(hash, *relem++, 0, 0);
1700 *relem++ = (he ? HeVAL(he) : &PL_sv_undef);
1701 }
1702 }
8b0c3377
DM
1703 }
1704 else {
1705 SV **svp;
1706 for (i = 0, svp = relem; svp <= lastrelem; i++, svp++) {
1707 SV *key = *svp++;
1708 SV *val = *svp;
1709 if (hv_store_ent(hash, key, val, 0))
1710 PL_tmps_stack[tmps_base + i] = &PL_sv_undef;
1711 else
1712 dirty_tmps = TRUE;
1713 /* hv_store_ent() may have added set magic to val */;
1714 SvSETMAGIC(val);
1715 }
1716 }
1717
1718 if (dirty_tmps) {
1719 /* there are still some 'live' recounts on the tmps stack
1720 * - usually caused by storing into a tied hash. So let
1721 * free_tmps() do the proper but slow job later.
1722 * Just disarm hash refcount: see comments below about leak
1723 */
1724 PL_tmps_stack[tmps_base - 1] = &PL_sv_undef;
1725 }
1726 else {
1727 /* Quietly remove all the SVs from the tmps stack slots,
1728 * since hash has now taken ownership of the refcnt.
1729 * Also remove hash: which will now leak if we die before
1730 * the SvREFCNT_dec_NN(hash) below */
1731 if (UNLIKELY(PL_tmps_ix >= tmps_base + nelems))
1732 Move(&PL_tmps_stack[tmps_base + nelems],
1733 &PL_tmps_stack[tmps_base - 1],
1734 PL_tmps_ix - (tmps_base + nelems) + 1,
1735 SV*);
1736 PL_tmps_ix -= (nelems + 1);
1737 }
1738
1739 SvREFCNT_dec_NN(hash);
1740
1741 relem = lastrelem + 1;
1742 goto no_relems;
1743 }
1744
a0d0e21e 1745 default:
8b0c3377 1746 if (!SvIMMORTAL(lsv)) {
d24e3eb1
DM
1747 SV *ref;
1748
8b0c3377
DM
1749 if (UNLIKELY(
1750 SvTEMP(lsv) && !SvSMAGICAL(lsv) && SvREFCNT(lsv) == 1 &&
1751 (!isGV_with_GP(lsv) || SvFAKE(lsv)) && ckWARN(WARN_MISC)
1752 ))
1753 Perl_warner(aTHX_
1754 packWARN(WARN_MISC),
1755 "Useless assignment to a temporary"
1756 );
d24e3eb1
DM
1757
1758 /* avoid freeing $$lsv if it might be needed for further
1759 * elements, e.g. ($ref, $foo) = (1, $$ref) */
1760 if ( SvROK(lsv)
1761 && ( ((ref = SvRV(lsv)), SvREFCNT(ref)) == 1)
1762 && lelem <= lastlelem
1763 ) {
1764 SSize_t ix;
1765 SvREFCNT_inc_simple_void_NN(ref);
1766 /* an unrolled sv_2mortal */
1767 ix = ++PL_tmps_ix;
1768 if (UNLIKELY(ix >= PL_tmps_max))
1769 /* speculatively grow enough to cover other
1770 * possible refs */
67c3640a 1771 (void)tmps_grow_p(ix + (lastlelem - lelem));
d24e3eb1
DM
1772 PL_tmps_stack[ix] = ref;
1773 }
1774
8b0c3377
DM
1775 sv_setsv(lsv, *relem);
1776 *relem = lsv;
1777 SvSETMAGIC(lsv);
1778 }
1779 if (++relem > lastrelem)
1780 goto no_relems;
a0d0e21e 1781 break;
8b0c3377
DM
1782 } /* switch */
1783 } /* while */
1784
1785
1786 no_relems:
1787
1788 /* simplified lelem loop for when there are no relems left */
1789 while (LIKELY(lelem <= lastlelem)) {
1790 SV *lsv = *lelem++;
c73f612f
DM
1791
1792 TAINT_NOT; /* Each item stands on its own, taintwise. */
1793
8b0c3377
DM
1794 if (UNLIKELY(!lsv)) {
1795 lsv = *lelem++;
1796 ASSUME(SvTYPE(lsv) == SVt_PVAV);
a0d0e21e 1797 }
8b0c3377
DM
1798
1799 switch (SvTYPE(lsv)) {
1800 case SVt_PVAV:
b09ed995
DM
1801 if (SvRMAGICAL(lsv) || AvFILLp((SV*)lsv) >= 0) {
1802 av_clear((AV*)lsv);
8b0c3377 1803 if (UNLIKELY(PL_delaymagic & DM_ARRAY_ISA))
b09ed995 1804 SvSETMAGIC(lsv);
8b0c3377
DM
1805 }
1806 break;
1807
1808 case SVt_PVHV:
b09ed995
DM
1809 if (SvRMAGICAL(lsv) || HvUSEDKEYS((HV*)lsv))
1810 hv_clear((HV*)lsv);
8b0c3377
DM
1811 break;
1812
1813 default:
1814 if (!SvIMMORTAL(lsv)) {
e03e82a0 1815 sv_set_undef(lsv);
8b0c3377 1816 SvSETMAGIC(lsv);
b09ed995 1817 *relem++ = lsv;
8b0c3377
DM
1818 }
1819 break;
1820 } /* switch */
1821 } /* while */
1822
c73f612f
DM
1823 TAINT_NOT; /* result of list assign isn't tainted */
1824
5d9574c1 1825 if (UNLIKELY(PL_delaymagic & ~DM_DELAY)) {
985213f2 1826 /* Will be used to set PL_tainting below */
dfff4baf
BF
1827 Uid_t tmp_uid = PerlProc_getuid();
1828 Uid_t tmp_euid = PerlProc_geteuid();
1829 Gid_t tmp_gid = PerlProc_getgid();
1830 Gid_t tmp_egid = PerlProc_getegid();
985213f2 1831
b469f1e0 1832 /* XXX $> et al currently silently ignore failures */
3280af22 1833 if (PL_delaymagic & DM_UID) {
a0d0e21e 1834#ifdef HAS_SETRESUID
b469f1e0
JH
1835 PERL_UNUSED_RESULT(
1836 setresuid((PL_delaymagic & DM_RUID) ? PL_delaymagic_uid : (Uid_t)-1,
1837 (PL_delaymagic & DM_EUID) ? PL_delaymagic_euid : (Uid_t)-1,
1838 (Uid_t)-1));
56febc5e
AD
1839#else
1840# ifdef HAS_SETREUID
b469f1e0
JH
1841 PERL_UNUSED_RESULT(
1842 setreuid((PL_delaymagic & DM_RUID) ? PL_delaymagic_uid : (Uid_t)-1,
1843 (PL_delaymagic & DM_EUID) ? PL_delaymagic_euid : (Uid_t)-1));
56febc5e
AD
1844# else
1845# ifdef HAS_SETRUID
b28d0864 1846 if ((PL_delaymagic & DM_UID) == DM_RUID) {
b469f1e0 1847 PERL_UNUSED_RESULT(setruid(PL_delaymagic_uid));
b28d0864 1848 PL_delaymagic &= ~DM_RUID;
a0d0e21e 1849 }
56febc5e
AD
1850# endif /* HAS_SETRUID */
1851# ifdef HAS_SETEUID
b28d0864 1852 if ((PL_delaymagic & DM_UID) == DM_EUID) {
b469f1e0 1853 PERL_UNUSED_RESULT(seteuid(PL_delaymagic_euid));
b28d0864 1854 PL_delaymagic &= ~DM_EUID;
a0d0e21e 1855 }
56febc5e 1856# endif /* HAS_SETEUID */
b28d0864 1857 if (PL_delaymagic & DM_UID) {
985213f2 1858 if (PL_delaymagic_uid != PL_delaymagic_euid)
cea2e8a9 1859 DIE(aTHX_ "No setreuid available");
b469f1e0 1860 PERL_UNUSED_RESULT(PerlProc_setuid(PL_delaymagic_uid));
a0d0e21e 1861 }
56febc5e
AD
1862# endif /* HAS_SETREUID */
1863#endif /* HAS_SETRESUID */
04783dc7 1864
985213f2
AB
1865 tmp_uid = PerlProc_getuid();
1866 tmp_euid = PerlProc_geteuid();
a0d0e21e 1867 }
b469f1e0 1868 /* XXX $> et al currently silently ignore failures */
3280af22 1869 if (PL_delaymagic & DM_GID) {
a0d0e21e 1870#ifdef HAS_SETRESGID
b469f1e0
JH
1871 PERL_UNUSED_RESULT(
1872 setresgid((PL_delaymagic & DM_RGID) ? PL_delaymagic_gid : (Gid_t)-1,
1873 (PL_delaymagic & DM_EGID) ? PL_delaymagic_egid : (Gid_t)-1,
1874 (Gid_t)-1));
56febc5e
AD
1875#else
1876# ifdef HAS_SETREGID
b469f1e0
JH
1877 PERL_UNUSED_RESULT(
1878 setregid((PL_delaymagic & DM_RGID) ? PL_delaymagic_gid : (Gid_t)-1,
1879 (PL_delaymagic & DM_EGID) ? PL_delaymagic_egid : (Gid_t)-1));
56febc5e
AD
1880# else
1881# ifdef HAS_SETRGID
b28d0864 1882 if ((PL_delaymagic & DM_GID) == DM_RGID) {
b469f1e0 1883 PERL_UNUSED_RESULT(setrgid(PL_delaymagic_gid));
b28d0864 1884 PL_delaymagic &= ~DM_RGID;
a0d0e21e 1885 }
56febc5e
AD
1886# endif /* HAS_SETRGID */
1887# ifdef HAS_SETEGID
b28d0864 1888 if ((PL_delaymagic & DM_GID) == DM_EGID) {
b469f1e0 1889 PERL_UNUSED_RESULT(setegid(PL_delaymagic_egid));
b28d0864 1890 PL_delaymagic &= ~DM_EGID;
a0d0e21e 1891 }
56febc5e 1892# endif /* HAS_SETEGID */
b28d0864 1893 if (PL_delaymagic & DM_GID) {
985213f2 1894 if (PL_delaymagic_gid != PL_delaymagic_egid)
cea2e8a9 1895 DIE(aTHX_ "No setregid available");
b469f1e0 1896 PERL_UNUSED_RESULT(PerlProc_setgid(PL_delaymagic_gid));
a0d0e21e 1897 }
56febc5e
AD
1898# endif /* HAS_SETREGID */
1899#endif /* HAS_SETRESGID */
04783dc7 1900
985213f2
AB
1901 tmp_gid = PerlProc_getgid();
1902 tmp_egid = PerlProc_getegid();
a0d0e21e 1903 }
284167a5 1904 TAINTING_set( TAINTING_get | (tmp_uid && (tmp_euid != tmp_uid || tmp_egid != tmp_gid)) );
9a9b5ec9
DM
1905#ifdef NO_TAINT_SUPPORT
1906 PERL_UNUSED_VAR(tmp_uid);
1907 PERL_UNUSED_VAR(tmp_euid);
1908 PERL_UNUSED_VAR(tmp_gid);
1909 PERL_UNUSED_VAR(tmp_egid);
1910#endif
a0d0e21e 1911 }
a68090fe 1912 PL_delaymagic = old_delaymagic;
54310121 1913
54310121
PP
1914 if (gimme == G_VOID)
1915 SP = firstrelem - 1;
1916 else if (gimme == G_SCALAR) {
54310121 1917 SP = firstrelem;
b09ed995 1918 EXTEND(SP,1);
7b394f12
DM
1919 if (PL_op->op_private & OPpASSIGN_TRUEBOOL)
1920 SETs((firstlelem - firstrelem) ? &PL_sv_yes : &PL_sv_zero);
1921 else {
1922 dTARGET;
1923 SETi(firstlelem - firstrelem);
1924 }
54310121 1925 }
b09ed995
DM
1926 else
1927 SP = relem - 1;
08aeb9f7 1928
54310121 1929 RETURN;
a0d0e21e
LW
1930}
1931
8782bef2
GB
1932PP(pp_qr)
1933{
20b7effb 1934 dSP;
eb578fdb 1935 PMOP * const pm = cPMOP;
fe578d7f 1936 REGEXP * rx = PM_GETRE(pm);
196a02af
DM
1937 regexp *prog = ReANY(rx);
1938 SV * const pkg = RXp_ENGINE(prog)->qr_package(aTHX_ (rx));
c4420975 1939 SV * const rv = sv_newmortal();
d63c20f2
DM
1940 CV **cvp;
1941 CV *cv;
288b8c02
NC
1942
1943 SvUPGRADE(rv, SVt_IV);
c2123ae3
NC
1944 /* For a subroutine describing itself as "This is a hacky workaround" I'm
1945 loathe to use it here, but it seems to be the right fix. Or close.
1946 The key part appears to be that it's essential for pp_qr to return a new
1947 object (SV), which implies that there needs to be an effective way to
1948 generate a new SV from the existing SV that is pre-compiled in the
1949 optree. */
1950 SvRV_set(rv, MUTABLE_SV(reg_temp_copy(NULL, rx)));
288b8c02
NC
1951 SvROK_on(rv);
1952
8d919b0a 1953 cvp = &( ReANY((REGEXP *)SvRV(rv))->qr_anoncv);
5d9574c1 1954 if (UNLIKELY((cv = *cvp) && CvCLONE(*cvp))) {
d63c20f2 1955 *cvp = cv_clone(cv);
fc2b2dca 1956 SvREFCNT_dec_NN(cv);
d63c20f2
DM
1957 }
1958
288b8c02 1959 if (pkg) {
f815daf2 1960 HV *const stash = gv_stashsv(pkg, GV_ADD);
fc2b2dca 1961 SvREFCNT_dec_NN(pkg);
288b8c02
NC
1962 (void)sv_bless(rv, stash);
1963 }
1964
196a02af 1965 if (UNLIKELY(RXp_ISTAINTED(prog))) {
e08e52cf 1966 SvTAINTED_on(rv);
9274aefd
DM
1967 SvTAINTED_on(SvRV(rv));
1968 }
c8c13c22 1969 XPUSHs(rv);
1970 RETURN;
8782bef2
GB
1971}
1972
a0d0e21e
LW
1973PP(pp_match)
1974{
20b7effb 1975 dSP; dTARG;
eb578fdb 1976 PMOP *pm = cPMOP;
d65afb4b 1977 PMOP *dynpm = pm;
eb578fdb 1978 const char *s;
5c144d81 1979 const char *strend;
99a90e59 1980 SSize_t curpos = 0; /* initial pos() or current $+[0] */
a0d0e21e 1981 I32 global;
7fadf4a7 1982 U8 r_flags = 0;
5c144d81 1983 const char *truebase; /* Start of string */
eb578fdb 1984 REGEXP *rx = PM_GETRE(pm);
196a02af 1985 regexp *prog = ReANY(rx);
b3eb6a9b 1986 bool rxtainted;
1c23e2bd 1987 const U8 gimme = GIMME_V;
a0d0e21e 1988 STRLEN len;
a3b680e6 1989 const I32 oldsave = PL_savestack_ix;
e60df1fa 1990 I32 had_zerolen = 0;
b1422d62 1991 MAGIC *mg = NULL;
a0d0e21e 1992
533c011a 1993 if (PL_op->op_flags & OPf_STACKED)
a0d0e21e
LW
1994 TARG = POPs;
1995 else {
9399c607
DM
1996 if (ARGTARG)
1997 GETTARGET;
1998 else {
1999 TARG = DEFSV;
2000 }
a0d0e21e
LW
2001 EXTEND(SP,1);
2002 }
d9f424b2 2003
c277df42 2004 PUTBACK; /* EVAL blocks need stack_sp. */
69dc4b30
FC
2005 /* Skip get-magic if this is a qr// clone, because regcomp has
2006 already done it. */
196a02af 2007 truebase = prog->mother_re
69dc4b30
FC
2008 ? SvPV_nomg_const(TARG, len)
2009 : SvPV_const(TARG, len);
f1d31338 2010 if (!truebase)
2269b42e 2011 DIE(aTHX_ "panic: pp_match");
f1d31338 2012 strend = truebase + len;
196a02af 2013 rxtainted = (RXp_ISTAINTED(prog) ||
284167a5 2014 (TAINT_get && (pm->op_pmflags & PMf_RETAINT)));
9212bbba 2015 TAINT_NOT;
a0d0e21e 2016
6c864ec2 2017 /* We need to know this in case we fail out early - pos() must be reset */
de0df3c0
MH
2018 global = dynpm->op_pmflags & PMf_GLOBAL;
2019
d65afb4b 2020 /* PMdf_USED is set after a ?? matches once */
c737faaf
YO
2021 if (
2022#ifdef USE_ITHREADS
2023 SvREADONLY(PL_regex_pad[pm->op_pmoffset])
2024#else
2025 pm->op_pmflags & PMf_USED
2026#endif
2027 ) {
e5dc5375 2028 DEBUG_r(PerlIO_printf(Perl_debug_log, "?? already matched once"));
de0df3c0 2029 goto nope;
a0d0e21e
LW
2030 }
2031
5585e758 2032 /* handle the empty pattern */
196a02af 2033 if (!RX_PRELEN(rx) && PL_curpm && !prog->mother_re) {
5585e758
YO
2034 if (PL_curpm == PL_reg_curpm) {
2035 if (PL_curpm_under) {
2036 if (PL_curpm_under == PL_reg_curpm) {
2037 Perl_croak(aTHX_ "Infinite recursion via empty pattern");
2038 } else {
2039 pm = PL_curpm_under;
2040 }
2041 }
2042 } else {
2043 pm = PL_curpm;
2044 }
2045 rx = PM_GETRE(pm);
196a02af 2046 prog = ReANY(rx);
a0d0e21e 2047 }
d65afb4b 2048
196a02af 2049 if (RXp_MINLEN(prog) >= 0 && (STRLEN)RXp_MINLEN(prog) > len) {
75d43e96 2050 DEBUG_r(PerlIO_printf(Perl_debug_log, "String shorter than min possible regex match (%"
147e3846 2051 UVuf " < %" IVdf ")\n",
196a02af 2052 (UV)len, (IV)RXp_MINLEN(prog)));
de0df3c0 2053 goto nope;
e5dc5375 2054 }
c277df42 2055
8ef97b0e 2056 /* get pos() if //g */
de0df3c0 2057 if (global) {
b1422d62 2058 mg = mg_find_mglob(TARG);
8ef97b0e 2059 if (mg && mg->mg_len >= 0) {
25fdce4a 2060 curpos = MgBYTEPOS(mg, TARG, truebase, len);
8ef97b0e
DM
2061 /* last time pos() was set, it was zero-length match */
2062 if (mg->mg_flags & MGf_MINMATCH)
2063 had_zerolen = 1;
2064 }
a0d0e21e 2065 }
8ef97b0e 2066
6e240d0b 2067#ifdef PERL_SAWAMPERSAND
196a02af 2068 if ( RXp_NPARENS(prog)
6502e081 2069 || PL_sawampersand
196a02af 2070 || (RXp_EXTFLAGS(prog) & (RXf_EVAL_SEEN|RXf_PMf_KEEPCOPY))
5b0e71e9 2071 || (dynpm->op_pmflags & PMf_KEEPCOPY)
6e240d0b
FC
2072 )
2073#endif
2074 {
6502e081
DM
2075 r_flags |= (REXEC_COPY_STR|REXEC_COPY_SKIP_PRE);
2076 /* in @a =~ /(.)/g, we iterate multiple times, but copy the buffer
2077 * only on the first iteration. Therefore we need to copy $' as well
2078 * as $&, to make the rest of the string available for captures in
2079 * subsequent iterations */
2080 if (! (global && gimme == G_ARRAY))
2081 r_flags |= REXEC_COPY_SKIP_POST;
2082 };
5b0e71e9
DM
2083#ifdef PERL_SAWAMPERSAND
2084 if (dynpm->op_pmflags & PMf_KEEPCOPY)
2085 /* handle KEEPCOPY in pmop but not rx, eg $r=qr/a/; /$r/p */
2086 r_flags &= ~(REXEC_COPY_SKIP_PRE|REXEC_COPY_SKIP_POST);
2087#endif
22e551b9 2088
f1d31338
DM
2089 s = truebase;
2090
d7be1480 2091 play_it_again:
985afbc1 2092 if (global)
03c83e26 2093 s = truebase + curpos;
f722798b 2094
77da2310 2095 if (!CALLREGEXEC(rx, (char*)s, (char *)strend, (char*)truebase,
03c83e26 2096 had_zerolen, TARG, NULL, r_flags))
03b6c93d 2097 goto nope;
77da2310
NC
2098
2099 PL_curpm = pm;
985afbc1 2100 if (dynpm->op_pmflags & PMf_ONCE)
c737faaf 2101#ifdef USE_ITHREADS
77da2310 2102 SvREADONLY_on(PL_regex_pad[dynpm->op_pmoffset]);
c737faaf 2103#else
77da2310 2104 dynpm->op_pmflags |= PMf_USED;
c737faaf 2105#endif
a0d0e21e 2106
72311751 2107 if (rxtainted)
196a02af
DM
2108 RXp_MATCH_TAINTED_on(prog);
2109 TAINT_IF(RXp_MATCH_TAINTED(prog));
35c2ccc3
DM
2110
2111 /* update pos */
2112
2113 if (global && (gimme != G_ARRAY || (dynpm->op_pmflags & PMf_CONTINUE))) {
b1422d62 2114 if (!mg)
35c2ccc3 2115 mg = sv_magicext_mglob(TARG);
196a02af
DM
2116 MgBYTEPOS_set(mg, TARG, truebase, RXp_OFFS(prog)[0].end);
2117 if (RXp_ZERO_LEN(prog))
adf51885
DM
2118 mg->mg_flags |= MGf_MINMATCH;
2119 else
2120 mg->mg_flags &= ~MGf_MINMATCH;
35c2ccc3
DM
2121 }
2122
196a02af 2123 if ((!RXp_NPARENS(prog) && !global) || gimme != G_ARRAY) {
bf9dff51
DM
2124 LEAVE_SCOPE(oldsave);
2125 RETPUSHYES;
2126 }
2127
88ab22af
DM
2128 /* push captures on stack */
2129
bf9dff51 2130 {
196a02af 2131 const I32 nparens = RXp_NPARENS(prog);
a3b680e6 2132 I32 i = (global && !nparens) ? 1 : 0;
a0d0e21e 2133
c277df42 2134 SPAGAIN; /* EVAL blocks could move the stack. */
ffc61ed2
JH
2135 EXTEND(SP, nparens + i);
2136 EXTEND_MORTAL(nparens + i);
2137 for (i = !i; i <= nparens; i++) {
a0d0e21e 2138 PUSHs(sv_newmortal());
196a02af
DM
2139 if (LIKELY((RXp_OFFS(prog)[i].start != -1)
2140 && RXp_OFFS(prog)[i].end != -1 ))
5d9574c1 2141 {
196a02af
DM
2142 const I32 len = RXp_OFFS(prog)[i].end - RXp_OFFS(prog)[i].start;
2143 const char * const s = RXp_OFFS(prog)[i].start + truebase;
2144 if (UNLIKELY( RXp_OFFS(prog)[i].end < 0
2145 || RXp_OFFS(prog)[i].start < 0
2146 || len < 0
2147 || len > strend - s)
2148 )
5637ef5b 2149 DIE(aTHX_ "panic: pp_match start/end pointers, i=%ld, "
147e3846 2150 "start=%ld, end=%ld, s=%p, strend=%p, len=%" UVuf,
196a02af
DM
2151 (long) i, (long) RXp_OFFS(prog)[i].start,
2152 (long)RXp_OFFS(prog)[i].end, s, strend, (UV) len);
a0d0e21e 2153 sv_setpvn(*SP, s, len);
cce850e4 2154 if (DO_UTF8(TARG) && is_utf8_string((U8*)s, len))
a197cbdd 2155 SvUTF8_on(*SP);
a0d0e21e
LW
2156 }
2157 }
2158 if (global) {
196a02af
DM
2159 curpos = (UV)RXp_OFFS(prog)[0].end;
2160 had_zerolen = RXp_ZERO_LEN(prog);
c277df42 2161 PUTBACK; /* EVAL blocks may use stack */
cf93c79d 2162 r_flags |= REXEC_IGNOREPOS | REXEC_NOT_FIRST;
a0d0e21e
LW
2163 goto play_it_again;
2164 }
4633a7c4 2165 LEAVE_SCOPE(oldsave);
a0d0e21e
LW
2166 RETURN;
2167 }
e5964223 2168 NOT_REACHED; /* NOTREACHED */
a0d0e21e 2169
7b52d656 2170 nope:
d65afb4b 2171 if (global && !(dynpm->op_pmflags & PMf_CONTINUE)) {
b1422d62
DM
2172 if (!mg)
2173 mg = mg_find_mglob(TARG);
2174 if (mg)
2175 mg->mg_len = -1;
a0d0e21e 2176 }
4633a7c4 2177 LEAVE_SCOPE(oldsave);
a0d0e21e
LW
2178 if (gimme == G_ARRAY)
2179 RETURN;
2180 RETPUSHNO;
2181}
2182
2183OP *
864dbfa3 2184Perl_do_readline(pTHX)
a0d0e21e 2185{
20b7effb 2186 dSP; dTARGETSTACKED;
eb578fdb 2187 SV *sv;
a0d0e21e
LW
2188 STRLEN tmplen = 0;
2189 STRLEN offset;
760ac839 2190 PerlIO *fp;
eb578fdb
KW
2191 IO * const io = GvIO(PL_last_in_gv);
2192 const I32 type = PL_op->op_type;
1c23e2bd 2193 const U8 gimme = GIMME_V;
a0d0e21e 2194
6136c704 2195 if (io) {
50db69d8 2196 const MAGIC *const mg = SvTIED_mg((const SV *)io, PERL_MAGIC_tiedscalar);
6136c704 2197 if (mg) {
3e0cb5de 2198 Perl_tied_method(aTHX_ SV_CONST(READLINE), SP, MUTABLE_SV(io), mg, gimme, 0);
6136c704 2199 if (gimme == G_SCALAR) {
50db69d8
NC
2200 SPAGAIN;
2201 SvSetSV_nosteal(TARG, TOPs);
2202 SETTARG;
6136c704 2203 }
50db69d8 2204 return NORMAL;
0b7c7b4f 2205 }
e79b0511 2206 }
4608196e 2207 fp = NULL;
a0d0e21e
LW
2208 if (io) {
2209 fp = IoIFP(io);
2210 if (!fp) {
2211 if (IoFLAGS(io) & IOf_ARGV) {
2212 if (IoFLAGS(io) & IOf_START) {
a0d0e21e 2213 IoLINES(io) = 0;
b9f2b683 2214 if (av_tindex(GvAVn(PL_last_in_gv)) < 0) {
1d7c1841 2215 IoFLAGS(io) &= ~IOf_START;
d5eb9a46 2216 do_open6(PL_last_in_gv, "-", 1, NULL, NULL, 0);
4bac9ae4 2217 SvTAINTED_off(GvSVn(PL_last_in_gv)); /* previous tainting irrelevant */
76f68e9b 2218 sv_setpvs(GvSVn(PL_last_in_gv), "-");
3280af22 2219 SvSETMAGIC(GvSV(PL_last_in_gv));
a2008d6d
GS
2220 fp = IoIFP(io);
2221 goto have_fp;
a0d0e21e
LW
2222 }
2223 }
157fb5a1 2224 fp = nextargv(PL_last_in_gv, PL_op->op_flags & OPf_SPECIAL);
a0d0e21e 2225 if (!fp) { /* Note: fp != IoIFP(io) */
3280af22 2226 (void)do_close(PL_last_in_gv, FALSE); /* now it does*/
a0d0e21e
LW
2227 }
2228 }
0d44d22b
NC
2229 else if (type == OP_GLOB)
2230 fp = Perl_start_glob(aTHX_ POPs, io);
a0d0e21e
LW
2231 }
2232 else if (type == OP_GLOB)
2233 SP--;
7716c5c5 2234 else if (IoTYPE(io) == IoTYPE_WRONLY) {
a5390457 2235 report_wrongway_fh(PL_last_in_gv, '>');
a00b5bd3 2236 }
a0d0e21e
LW
2237 }
2238 if (!fp) {
041457d9 2239 if ((!io || !(IoFLAGS(io) & IOf_START))
de7dabb6
TC
2240 && ckWARN(WARN_CLOSED)
2241 && type != OP_GLOB)
041457d9 2242 {
de7dabb6 2243 report_evil_fh(PL_last_in_gv);
3f4520fe 2244 }
54310121 2245 if (gimme == G_SCALAR) {
79628082 2246 /* undef TARG, and push that undefined value */
ba92458f 2247 if (type != OP_RCATLINE) {
3773545d 2248 sv_set_undef(TARG);
ba92458f 2249 }
a0d0e21e
LW
2250 PUSHTARG;
2251 }
2252 RETURN;
2253 }
a2008d6d 2254 have_fp:
54310121 2255 if (gimme == G_SCALAR) {
a0d0e21e 2256 sv = TARG;
0f722b55
RGS
2257 if (type == OP_RCATLINE && SvGMAGICAL(sv))
2258 mg_get(sv);
48de12d9
RGS
2259 if (SvROK(sv)) {
2260 if (type == OP_RCATLINE)
5668452f 2261 SvPV_force_nomg_nolen(sv);
48de12d9
RGS
2262 else
2263 sv_unref(sv);
2264 }
f7877b28 2265 else if (isGV_with_GP(sv)) {
5668452f 2266 SvPV_force_nomg_nolen(sv);
f7877b28 2267 }
862a34c6 2268 SvUPGRADE(sv, SVt_PV);
a0d0e21e 2269 tmplen = SvLEN(sv); /* remember if already alloced */
e3918bb7 2270 if (!tmplen && !SvREADONLY(sv) && !SvIsCOW(sv)) {
f72e8700
JJ
2271 /* try short-buffering it. Please update t/op/readline.t
2272 * if you change the growth length.
2273 */
2274 Sv_Grow(sv, 80);
2275 }
2b5e58c4
AMS
2276 offset = 0;
2277 if (type == OP_RCATLINE && SvOK(sv)) {
2278 if (!SvPOK(sv)) {
5668452f 2279 SvPV_force_nomg_nolen(sv);
2b5e58c4 2280 }
a0d0e21e 2281 offset = SvCUR(sv);
2b5e58c4 2282 }
a0d0e21e 2283 }
54310121 2284 else {
561b68a9 2285 sv = sv_2mortal(newSV(80));
54310121
PP
2286 offset = 0;
2287 }
fbad3eb5 2288
3887d568
AP
2289 /* This should not be marked tainted if the fp is marked clean */
2290#define MAYBE_TAINT_LINE(io, sv) \
2291 if (!(IoFLAGS(io) & IOf_UNTAINT)) { \
2292 TAINT; \
2293 SvTAINTED_on(sv); \
2294 }
2295
684bef36 2296/* delay EOF state for a snarfed empty file */
fbad3eb5 2297#define SNARF_EOF(gimme,rs,io,sv) \
684bef36 2298 (gimme != G_SCALAR || SvCUR(sv) \
b9fee9ba 2299 || (IoFLAGS(io) & IOf_NOLINE) || !RsSNARF(rs))
fbad3eb5 2300
a0d0e21e 2301 for (;;) {
09e8efcc 2302 PUTBACK;
fbad3eb5 2303 if (!sv_gets(sv, fp, offset)
2d726892
TF
2304 && (type == OP_GLOB
2305 || SNARF_EOF(gimme, PL_rs, io, sv)
2306 || PerlIO_error(fp)))
fbad3eb5 2307 {
760ac839 2308 PerlIO_clearerr(fp);
a0d0e21e 2309 if (IoFLAGS(io) & IOf_ARGV) {
157fb5a1 2310 fp = nextargv(PL_last_in_gv, PL_op->op_flags & OPf_SPECIAL);
a0d0e21e
LW
2311 if (fp)
2312 continue;
3280af22 2313 (void)do_close(PL_last_in_gv, FALSE);
a0d0e21e
LW
2314 }
2315 else if (type == OP_GLOB) {
a2a5de95
NC
2316 if (!do_close(PL_last_in_gv, FALSE)) {
2317 Perl_ck_warner(aTHX_ packWARN(WARN_GLOB),
2318 "glob failed (child exited with status %d%s)",
2319 (int)(STATUS_CURRENT >> 8),
2320 (STATUS_CURRENT & 0x80) ? ", core dumped" : "");
4eb79ab5 2321 }
a0d0e21e 2322 }
54310121 2323 if (gimme == G_SCALAR) {
ba92458f
AE
2324 if (type != OP_RCATLINE) {
2325 SV_CHECK_THINKFIRST_COW_DROP(TARG);
0c34ef67 2326 SvOK_off(TARG);
ba92458f 2327 }
09e8efcc 2328 SPAGAIN;
a0d0e21e
LW
2329 PUSHTARG;
2330 }
3887d568 2331 MAYBE_TAINT_LINE(io, sv);
a0d0e21e
LW
2332 RETURN;
2333 }
3887d568 2334 MAYBE_TAINT_LINE(io, sv);
a0d0e21e 2335 IoLINES(io)++;
b9fee9ba 2336 IoFLAGS(io) |= IOf_NOLINE;
71be2cbc 2337 SvSETMAGIC(sv);
09e8efcc 2338 SPAGAIN;
a0d0e21e 2339 XPUSHs(sv);
a0d0e21e 2340 if (type == OP_GLOB) {
349d4f2f 2341 const char *t1;
45a23732 2342 Stat_t statbuf;
a0d0e21e 2343
3280af22 2344 if (SvCUR(sv) > 0 && SvCUR(PL_rs) > 0) {
6136c704 2345 char * const tmps = SvEND(sv) - 1;
aa07b2f6 2346 if (*tmps == *SvPVX_const(PL_rs)) {
c07a80fd 2347 *tmps = '\0';
b162af07 2348 SvCUR_set(sv, SvCUR(sv) - 1);
c07a80fd
PP
2349 }
2350 }
349d4f2f 2351 for (t1 = SvPVX_const(sv); *t1; t1++)
b51c3e77
CB
2352#ifdef __VMS
2353 if (strchr("*%?", *t1))
2354#else
7ad1e72d 2355 if (strchr("$&*(){}[]'\";\\|?<>~`", *t1))
b51c3e77 2356#endif
a0d0e21e 2357 break;
45a23732 2358 if (*t1 && PerlLIO_lstat(SvPVX_const(sv), &statbuf) < 0) {
a0d0e21e
LW
2359 (void)POPs; /* Unmatched wildcard? Chuck it... */
2360 continue;
2361 }
2d79bf7f 2362 } else if (SvUTF8(sv)) { /* OP_READLINE, OP_RCATLINE */
d4c19fe8
AL
2363 if (ckWARN(WARN_UTF8)) {
2364 const U8 * const s = (const U8*)SvPVX_const(sv) + offset;
2365 const STRLEN len = SvCUR(sv) - offset;
2366 const U8 *f;
2367
2368 if (!is_utf8_string_loc(s, len, &f))
2369 /* Emulate :encoding(utf8) warning in the same case. */
2370 Perl_warner(aTHX_ packWARN(WARN_UTF8),
2371 "utf8 \"\\x%02X\" does not map to Unicode",
2372 f < (U8*)SvEND(sv) ? *f : 0);
2373 }
a0d0e21e 2374 }
54310121 2375 if (gimme == G_ARRAY) {
a0d0e21e 2376 if (SvLEN(sv) - SvCUR(sv) > 20) {
1da4ca5f 2377 SvPV_shrink_to_cur(sv);
a0d0e21e 2378 }
561b68a9 2379 sv = sv_2mortal(newSV(80));
a0d0e21e
LW
2380 continue;
2381 }
54310121 2382 else if (gimme == G_SCALAR && !tmplen && SvLEN(sv) - SvCUR(sv) > 80) {
a0d0e21e 2383 /* try to reclaim a bit of scalar space (only on 1st alloc) */
d5b5861b
NC
2384 const STRLEN new_len
2385 = SvCUR(sv) < 60 ? 80 : SvCUR(sv)+40; /* allow some slop */
1da4ca5f 2386 SvPV_renew(sv, new_len);
a0d0e21e
LW
2387 }
2388 RETURN;
2389 }
2390}
2391
a0d0e21e
LW
2392PP(pp_helem)
2393{
20b7effb 2394 dSP;
760ac839 2395 HE* he;
ae77835f 2396 SV **svp;
c445ea15 2397 SV * const keysv = POPs;
85fbaab2 2398 HV * const hv = MUTABLE_HV(POPs);
a3b680e6
AL
2399 const U32 lval = PL_op->op_flags & OPf_MOD || LVRET;
2400 const U32 defer = PL_op->op_private & OPpLVAL_DEFER;
be6c24e0 2401 SV *sv;
92970b93 2402 const bool localizing = PL_op->op_private & OPpLVAL_INTRO;
d30e492c 2403 bool preeminent = TRUE;
a0d0e21e 2404
6dfc73ea
SM
2405 if (SvTYPE(hv) != SVt_PVHV)
2406 RETPUSHUNDEF;
d4c19fe8 2407
92970b93 2408 if (localizing) {
d4c19fe8
AL
2409 MAGIC *mg;
2410 HV *stash;
d30e492c
VP
2411
2412 /* If we can determine whether the element exist,
2413 * Try to preserve the existenceness of a tied hash
2414 * element by using EXISTS and DELETE if possible.
2415 * Fallback to FETCH and STORE otherwise. */
2c5f48c2 2416 if (SvCANEXISTDELETE(hv))
d30e492c 2417 preeminent = hv_exists_ent(hv, keysv, 0);
d4c19fe8 2418 }
d30e492c 2419
5f9d7e2b 2420 he = hv_fetch_ent(hv, keysv, lval && !defer, 0);
d4c19fe8 2421 svp = he ? &HeVAL(he) : NULL;
a0d0e21e 2422 if (lval) {
746f6409 2423 if (!svp || !*svp || *svp == &PL_sv_undef) {
68dc0745
PP
2424 SV* lv;
2425 SV* key2;
2d8e6c8d 2426 if (!defer) {
be2597df 2427 DIE(aTHX_ PL_no_helem_sv, SVfARG(keysv));
2d8e6c8d 2428 }
68dc0745
PP
2429 lv = sv_newmortal();
2430 sv_upgrade(lv, SVt_PVLV);
2431 LvTYPE(lv) = 'y';
6136c704 2432 sv_magic(lv, key2 = newSVsv(keysv), PERL_MAGIC_defelem, NULL, 0);
fc2b2dca 2433 SvREFCNT_dec_NN(key2); /* sv_magic() increments refcount */
0ad694a7 2434 LvTARG(lv) = SvREFCNT_inc_simple_NN(hv);
68dc0745
PP
2435 LvTARGLEN(lv) = 1;
2436 PUSHs(lv);
2437 RETURN;
2438 }
92970b93 2439 if (localizing) {
bfcb3514 2440 if (HvNAME_get(hv) && isGV(*svp))
159b6efe 2441 save_gp(MUTABLE_GV(*svp), !(PL_op->op_flags & OPf_SPECIAL));
47cfc530
VP
2442 else if (preeminent)
2443 save_helem_flags(hv, keysv, svp,
2444 (PL_op->op_flags & OPf_SPECIAL) ? 0 : SAVEf_SETMAGIC);
2445 else
2446 SAVEHDELETE(hv, keysv);
5f05dabc 2447 }
9026059d
GG
2448 else if (PL_op->op_private & OPpDEREF) {
2449 PUSHs(vivify_ref(*svp, PL_op->op_private & OPpDEREF));
2450 RETURN;
2451 }
a0d0e21e 2452 }
746f6409 2453 sv = (svp && *svp ? *svp : &PL_sv_undef);
fd69380d
DM
2454 /* Originally this did a conditional C<sv = sv_mortalcopy(sv)>; this
2455 * was to make C<local $tied{foo} = $tied{foo}> possible.
2456 * However, it seems no longer to be needed for that purpose, and
2457 * introduced a new bug: stuff like C<while ($hash{taintedval} =~ /.../g>
2458 * would loop endlessly since the pos magic is getting set on the
2459 * mortal copy and lost. However, the copy has the effect of
2460 * triggering the get magic, and losing it altogether made things like
2461 * c<$tied{foo};> in void context no longer do get magic, which some
2462 * code relied on. Also, delayed triggering of magic on @+ and friends
2463 * meant the original regex may be out of scope by now. So as a
2464 * compromise, do the get magic here. (The MGf_GSKIP flag will stop it
2465 * being called too many times). */
39cf747a 2466 if (!lval && SvRMAGICAL(hv) && SvGMAGICAL(sv))
fd69380d 2467 mg_get(sv);
be6c24e0 2468 PUSHs(sv);
a0d0e21e
LW
2469 RETURN;
2470}
2471
fedf30e1
DM
2472
2473/* a stripped-down version of Perl_softref2xv() for use by
2474 * pp_multideref(), which doesn't use PL_op->op_flags */
2475
f9db5646 2476STATIC GV *
fedf30e1
DM
2477S_softref2xv_lite(pTHX_ SV *const sv, const char *const what,
2478 const svtype type)
2479{
2480 if (PL_op->op_private & HINT_STRICT_REFS) {
2481 if (SvOK(sv))
2482 Perl_die(aTHX_ PL_no_symref_sv, sv,
2483 (SvPOKp(sv) && SvCUR(sv)>32 ? "..." : ""), what);
2484 else
2485 Perl_die(aTHX_ PL_no_usym, what);
2486 }
2487 if (!SvOK(sv))
2488 Perl_die(aTHX_ PL_no_usym, what);
2489 return gv_fetchsv_nomg(sv, GV_ADD, type);
2490}
2491
2492
79815f56
DM
2493/* Handle one or more aggregate derefs and array/hash indexings, e.g.
2494 * $h->{foo} or $a[0]{$key}[$i] or f()->[1]
fedf30e1
DM
2495 *
2496 * op_aux points to an array of unions of UV / IV / SV* / PADOFFSET.
79815f56
DM
2497 * Each of these either contains a set of actions, or an argument, such as
2498 * an IV to use as an array index, or a lexical var to retrieve.
2499 * Several actions re stored per UV; we keep shifting new actions off the
2500 * one UV, and only reload when it becomes zero.
fedf30e1
DM
2501 */
2502
2503PP(pp_multideref)
2504{
2505 SV *sv = NULL; /* init to avoid spurious 'may be used uninitialized' */
2506 UNOP_AUX_item *items = cUNOP_AUXx(PL_op)->op_aux;
2507 UV actions = items->uv;
2508
2509 assert(actions);
2510 /* this tells find_uninit_var() where we're up to */
2511 PL_multideref_pc = items;
2512
2513 while (1) {
2514 /* there are three main classes of action; the first retrieve
2515 * the initial AV or HV from a variable or the stack; the second
2516 * does the equivalent of an unrolled (/DREFAV, rv2av, aelem),
2517 * the third an unrolled (/DREFHV, rv2hv, helem).
2518 */
2519 switch (actions & MDEREF_ACTION_MASK) {
2520
2521 case MDEREF_reload:
2522 actions = (++items)->uv;
2523 continue;
2524
2525 case MDEREF_AV_padav_aelem: /* $lex[...] */
2526 sv = PAD_SVl((++items)->pad_offset);
2527 goto do_AV_aelem;
2528
2529 case MDEREF_AV_gvav_aelem: /* $pkg[...] */
2530 sv = UNOP_AUX_item_sv(++items);
2531 assert(isGV_with_GP(sv));
2532 sv = (SV*)GvAVn((GV*)sv);
2533 goto do_AV_aelem;
2534
2535 case MDEREF_AV_pop_rv2av_aelem: /* expr->[...] */
2536 {
2537 dSP;
2538 sv = POPs;
2539 PUTBACK;
2540 goto do_AV_rv2av_aelem;
2541 }
2542
2543 case MDEREF_AV_gvsv_vivify_rv2av_aelem: /* $pkg->[...] */
2544 sv = UNOP_AUX_item_sv(++items);
2545 assert(isGV_with_GP(sv));
2546 sv = GvSVn((GV*)sv);
2547 goto do_AV_vivify_rv2av_aelem;
2548
2549 case MDEREF_AV_padsv_vivify_rv2av_aelem: /* $lex->[...] */
2550 sv = PAD_SVl((++items)->pad_offset);
2551 /* FALLTHROUGH */
2552
2553 do_AV_vivify_rv2av_aelem:
2554 case MDEREF_AV_vivify_rv2av_aelem: /* vivify, ->[...] */
2555 /* this is the OPpDEREF action normally found at the end of
2556 * ops like aelem, helem, rv2sv */
2557 sv = vivify_ref(sv, OPpDEREF_AV);
2558 /* FALLTHROUGH */
2559
2560 do_AV_rv2av_aelem:
2561 /* this is basically a copy of pp_rv2av when it just has the
2562 * sKR/1 flags */
2563 SvGETMAGIC(sv);
2564 if (LIKELY(SvROK(sv))) {
2565 if (UNLIKELY(SvAMAGIC(sv))) {
2566 sv = amagic_deref_call(sv, to_av_amg);
2567 }
2568 sv = SvRV(sv);
2569 if (UNLIKELY(SvTYPE(sv) != SVt_PVAV))
2570 DIE(aTHX_ "Not an ARRAY reference");
2571 }
2572 else if (SvTYPE(sv) != SVt_PVAV) {
2573 if (!isGV_with_GP(sv))
2574 sv = (SV*)S_softref2xv_lite(aTHX_ sv, "an ARRAY", SVt_PVAV);
2575 sv = MUTABLE_SV(GvAVn((GV*)sv));
2576 }
2577 /* FALLTHROUGH */
2578
2579 do_AV_aelem:
2580 {
2581 /* retrieve the key; this may be either a lexical or package
2582 * var (whose index/ptr is stored as an item) or a signed
2583 * integer constant stored as an item.
2584 */
2585 SV *elemsv;
2586 IV elem = 0; /* to shut up stupid compiler warnings */
2587
2588
2589 assert(SvTYPE(sv) == SVt_PVAV);
2590
2591 switch (actions & MDEREF_INDEX_MASK) {
2592 case MDEREF_INDEX_none:
2593 goto finish;
2594 case MDEREF_INDEX_const:
2595 elem = (++items)->iv;
2596 break;
2597 case MDEREF_INDEX_padsv:
2598 elemsv = PAD_SVl((++items)->pad_offset);
2599 goto check_elem;
2600 case MDEREF_INDEX_gvsv:
2601 elemsv = UNOP_AUX_item_sv(++items);
2602 assert(isGV_with_GP(elemsv));
2603 elemsv = GvSVn((GV*)elemsv);
2604 check_elem:
2605 if (UNLIKELY(SvROK(elemsv) && !SvGAMAGIC(elemsv)
2606 && ckWARN(WARN_MISC)))
2607 Perl_warner(aTHX_ packWARN(WARN_MISC),
147e3846 2608 "Use of reference \"%" SVf "\" as array index",
fedf30e1
DM
2609 SVfARG(elemsv));
2610 /* the only time that S_find_uninit_var() needs this
2611 * is to determine which index value triggered the
2612 * undef warning. So just update it here. Note that
2613 * since we don't save and restore this var (e.g. for
2614 * tie or overload execution), its value will be
2615 * meaningless apart from just here */
2616 PL_multideref_pc = items;
2617 elem = SvIV(elemsv);
2618 break;
2619 }
2620
2621
2622 /* this is basically a copy of pp_aelem with OPpDEREF skipped */
2623
2624 if (!(actions & MDEREF_FLAG_last)) {
2625 SV** svp = av_fetch((AV*)sv, elem, 1);
2626 if (!svp || ! (sv=*svp))
2627 DIE(aTHX_ PL_no_aelem, elem);
2628 break;
2629 }
2630
2631 if (PL_op->op_private &
2632 (OPpMULTIDEREF_EXISTS|OPpMULTIDEREF_DELETE))
2633 {
2634 if (PL_op->op_private & OPpMULTIDEREF_EXISTS) {
2635 sv = av_exists((AV*)sv, elem) ? &PL_sv_yes : &PL_sv_no;
2636 }
2637 else {
2638 I32 discard = (GIMME_V == G_VOID) ? G_DISCARD : 0;
2639 sv = av_delete((AV*)sv, elem, discard);
2640 if (discard)
2641 return NORMAL;
2642 if (!sv)
2643 sv = &PL_sv_undef;
2644 }
2645 }
2646 else {
2647 const U32 lval = PL_op->op_flags & OPf_MOD || LVRET;
2648 const U32 defer = PL_op->op_private & OPpLVAL_DEFER;
2649 const bool localizing = PL_op->op_private & OPpLVAL_INTRO;
2650 bool preeminent = TRUE;
2651 AV *const av = (AV*)sv;
2652 SV** svp;
2653
2654 if (UNLIKELY(localizing)) {
2655 MAGIC *mg;
2656 HV *stash;
2657
2658 /* If we can determine whether the element exist,
2659 * Try to preserve the existenceness of a tied array
2660 * element by using EXISTS and DELETE if possible.
2661 * Fallback to FETCH and STORE otherwise. */
2662 if (SvCANEXISTDELETE(av))
2663 preeminent = av_exists(av, elem);
2664 }
2665
2666 svp = av_fetch(av, elem, lval && !defer);
2667
2668 if (lval) {
2669 if (!svp || !(sv = *svp)) {
2670 IV len;
2671 if (!defer)
2672 DIE(aTHX_ PL_no_aelem, elem);
2673 len = av_tindex(av);
2674 sv = sv_2mortal(newSVavdefelem(av,
2675 /* Resolve a negative index now, unless it points
2676 * before the beginning of the array, in which
2677 * case record it for error reporting in
2678 * magic_setdefelem. */
2679 elem < 0 && len + elem >= 0
2680 ? len + elem : elem, 1));
2681 }
2682 else {
2683 if (UNLIKELY(localizing)) {
2684 if (preeminent) {
2685 save_aelem(av, elem, svp);
2686 sv = *svp; /* may have changed */
2687 }
2688 else
2689 SAVEADELETE(av, elem);
2690 }
2691 }
2692 }
2693 else {
2694 sv = (svp ? *svp : &PL_sv_undef);
2695 /* see note in pp_helem() */
2696 if (SvRMAGICAL(av) && SvGMAGICAL(sv))
2697 mg_get(sv);
2698 }
2699 }
2700
2701 }
2702 finish:
2703 {
2704 dSP;
2705 XPUSHs(sv);
2706 RETURN;
2707 }
2708 /* NOTREACHED */
2709
2710
2711
2712
2713 case MDEREF_HV_padhv_helem: /* $lex{...} */
2714 sv = PAD_SVl((++items)->pad_offset);
2715 goto do_HV_helem;
2716
2717 case MDEREF_HV_gvhv_helem: /* $pkg{...} */
2718 sv = UNOP_AUX_item_sv(++items);
2719 assert(isGV_with_GP(sv));
2720 sv = (SV*)GvHVn((GV*)sv);
2721 goto do_HV_helem;
2722
2723 case MDEREF_HV_pop_rv2hv_helem: /* expr->{...} */
2724 {
2725 dSP;
2726 sv = POPs;
2727 PUTBACK;
2728 goto do_HV_rv2hv_helem;
2729 }
2730
2731 case MDEREF_HV_gvsv_vivify_rv2hv_helem: /* $pkg->{...} */
2732 sv = UNOP_AUX_item_sv(++items);
2733 assert(isGV_with_GP(sv));
2734 sv = GvSVn((GV*)sv);
2735 goto do_HV_vivify_rv2hv_helem;
2736
2737 case MDEREF_HV_padsv_vivify_rv2hv_helem: /* $lex->{...} */
2738 sv = PAD_SVl((++items)->pad_offset);
2739 /* FALLTHROUGH */
2740
2741 do_HV_vivify_rv2hv_helem:
2742 case MDEREF_HV_vivify_rv2hv_helem: /* vivify, ->{...} */
2743 /* this is the OPpDEREF action normally found at the end of
2744 * ops like aelem, helem, rv2sv */
2745 sv = vivify_ref(sv, OPpDEREF_HV);
2746 /* FALLTHROUGH */
2747
2748 do_HV_rv2hv_helem:
2749 /* this is basically a copy of pp_rv2hv when it just has the
2750 * sKR/1 flags (and pp_rv2hv is aliased to pp_rv2av) */
2751
2752 SvGETMAGIC(sv);
2753 if (LIKELY(SvROK(sv))) {
2754 if (UNLIKELY(SvAMAGIC(sv))) {
2755 sv = amagic_deref_call(sv, to_hv_amg);
2756 }
2757 sv = SvRV(sv);
2758 if (UNLIKELY(SvTYPE(sv) != SVt_PVHV))
2759 DIE(aTHX_ "Not a HASH reference");
2760 }
2761 else if (SvTYPE(sv) != SVt_PVHV) {
2762 if (!isGV_with_GP(sv))
2763 sv = (SV*)S_softref2xv_lite(aTHX_ sv, "a HASH", SVt_PVHV);
2764 sv = MUTABLE_SV(GvHVn((GV*)sv));
2765 }
2766 /* FALLTHROUGH */
2767
2768 do_HV_helem:
2769 {
2770 /* retrieve the key; this may be either a lexical / package
2771 * var or a string constant, whose index/ptr is stored as an
2772 * item
2773 */
2774 SV *keysv = NULL; /* to shut up stupid compiler warnings */
2775
2776 assert(SvTYPE(sv) == SVt_PVHV);
2777
2778 switch (actions & MDEREF_INDEX_MASK) {
2779 case MDEREF_INDEX_none:
2780 goto finish;
2781
2782 case MDEREF_INDEX_const:
2783 keysv = UNOP_AUX_item_sv(++items);
2784 break;
2785
2786 case MDEREF_INDEX_padsv:
2787 keysv = PAD_SVl((++items)->pad_offset);
2788 break;
2789
2790 case MDEREF_INDEX_gvsv:
2791 keysv = UNOP_AUX_item_sv(++items);
2792 keysv = GvSVn((GV*)keysv);
2793 break;
2794 }
2795
2796 /* see comment above about setting this var */
2797 PL_multideref_pc = items;
2798
2799
2800 /* ensure that candidate CONSTs have been HEKified */
2801 assert( ((actions & MDEREF_INDEX_MASK) != MDEREF_INDEX_const)
2802 || SvTYPE(keysv) >= SVt_PVMG
2803 || !SvOK(keysv)
2804 || SvROK(keysv)
2805 || SvIsCOW_shared_hash(keysv));
2806
2807 /* this is basically a copy of pp_helem with OPpDEREF skipped */
2808
2809 if (!(actions & MDEREF_FLAG_last)) {
2810 HE *he = hv_fetch_ent((HV*)sv, keysv, 1, 0);
2811 if (!he || !(sv=HeVAL(he)) || sv == &PL_sv_undef)
2812 DIE(aTHX_ PL_no_helem_sv, SVfARG(keysv));
2813 break;
2814 }
2815
2816 if (PL_op->op_private &
2817 (OPpMULTIDEREF_EXISTS|OPpMULTIDEREF_DELETE))
2818 {
2819 if (PL_op->op_private & OPpMULTIDEREF_EXISTS) {
2820 sv = hv_exists_ent((HV*)sv, keysv, 0)
2821 ? &PL_sv_yes : &PL_sv_no;
2822 }
2823 else {
2824 I32 discard = (GIMME_V == G_VOID) ? G_DISCARD : 0;
2825 sv = hv_delete_ent((HV*)sv, keysv, discard, 0);
2826 if (discard)
2827 return NORMAL;
2828 if (!sv)
2829 sv = &PL_sv_undef;
2830 }
2831 }
2832 else {
2833 const U32 lval = PL_op->op_flags & OPf_MOD || LVRET;
2834 const U32 defer = PL_op->op_private & OPpLVAL_DEFER;
2835 const bool localizing = PL_op->op_private & OPpLVAL_INTRO;
2836 bool preeminent = TRUE;
2837 SV **svp;
2838 HV * const hv = (HV*)sv;
2839 HE* he;
2840
2841 if (UNLIKELY(localizing)) {
2842 MAGIC *mg;
2843 HV *stash;
2844
2845 /* If we can determine whether the element exist,
2846 * Try to preserve the existenceness of a tied hash
2847 * element by using EXISTS and DELETE if possible.
2848 * Fallback to FETCH and STORE otherwise. */
2849 if (SvCANEXISTDELETE(hv))
2850 preeminent = hv_exists_ent(hv, keysv, 0);
2851 }
2852
2853 he = hv_fetch_ent(hv, keysv, lval && !defer, 0);
2854 svp = he ? &HeVAL(he) : NULL;
2855
2856
2857 if (lval) {
2858 if (!svp || !(sv = *svp) || sv == &PL_sv_undef) {
2859 SV* lv;
2860 SV* key2;
2861 if (!defer)
2862 DIE(aTHX_ PL_no_helem_sv, SVfARG(keysv));
2863 lv = sv_newmortal();
2864 sv_upgrade(lv, SVt_PVLV);
2865 LvTYPE(lv) = 'y';
2866 sv_magic(lv, key2 = newSVsv(keysv),
2867 PERL_MAGIC_defelem, NULL, 0);
2868 /* sv_magic() increments refcount */
2869 SvREFCNT_dec_NN(key2);
0ad694a7 2870 LvTARG(lv) = SvREFCNT_inc_simple_NN(hv);
fedf30e1
DM
2871 LvTARGLEN(lv) = 1;
2872 sv = lv;
2873 }
2874 else {
2875 if (localizing) {
2876 if (HvNAME_get(hv) && isGV(sv))
2877 save_gp(MUTABLE_GV(sv),
2878 !(PL_op->op_flags & OPf_SPECIAL));
2879 else if (preeminent) {
2880 save_helem_flags(hv, keysv, svp,
2881 (PL_op->op_flags & OPf_SPECIAL)
2882 ? 0 : SAVEf_SETMAGIC);
2883 sv = *svp; /* may have changed */
2884 }
2885 else
2886 SAVEHDELETE(hv, keysv);
2887 }
2888 }
2889 }
2890 else {
2891 sv = (svp && *svp ? *svp : &PL_sv_undef);
2892 /* see note in pp_helem() */
2893 if (SvRMAGICAL(hv) && SvGMAGICAL(sv))
2894 mg_get(sv);
2895 }
2896 }
2897 goto finish;
2898 }
2899
2900 } /* switch */
2901
2902 actions >>= MDEREF_SHIFT;
2903 } /* while */
2904 /* NOTREACHED */
2905}
2906
2907
a0d0e21e
LW
2908PP(pp_iter)
2909{
eb578fdb 2910 PERL_CONTEXT *cx;
7d6c2cef 2911 SV *oldsv;
1d7c1841 2912 SV **itersvp;
a0d0e21e 2913
84f05d57
JH
2914 SV *sv;
2915 AV *av;
2916 IV ix;
2917 IV inc;
2918
4ebe6e95 2919 cx = CX_CUR();
1d7c1841 2920 itersvp = CxITERVAR(cx);
4b5c941e 2921 assert(itersvp);
a48ce6be
DM
2922
2923 switch (CxTYPE(cx)) {
17c91640 2924
b552b52c
DM
2925 case CXt_LOOP_LAZYSV: /* string increment */
2926 {
2927 SV* cur = cx->blk_loop.state_u.lazysv.cur;
2928 SV *end = cx->blk_loop.state_u.lazysv.end;
2929 /* If the maximum is !SvOK(), pp_enteriter substitutes PL_sv_no.
2930 It has SvPVX of "" and SvCUR of 0, which is what we want. */
2931 STRLEN maxlen = 0;
2932 const char *max = SvPV_const(end, maxlen);
d6c970c7
AC
2933 if (DO_UTF8(end) && IN_UNI_8_BIT)
2934 maxlen = sv_len_utf8_nomg(end);
5d9574c1 2935 if (UNLIKELY(SvNIOK(cur) || SvCUR(cur) > maxlen))
8a1f10dd 2936 goto retno;
b552b52c
DM
2937
2938 oldsv = *itersvp;
6d3ca00e
DM
2939 /* NB: on the first iteration, oldsv will have a ref count of at
2940 * least 2 (one extra from blk_loop.itersave), so the GV or pad
2941 * slot will get localised; on subsequent iterations the RC==1
2942 * optimisation may kick in and the SV will be reused. */
2943 if (oldsv && LIKELY(SvREFCNT(oldsv) == 1 && !SvMAGICAL(oldsv))) {
b552b52c
DM
2944 /* safe to reuse old SV */
2945 sv_setsv(oldsv, cur);
a48ce6be 2946 }
b552b52c
DM
2947 else
2948 {
2949 /* we need a fresh SV every time so that loop body sees a
2950 * completely new SV for closures/references to work as
2951 * they used to */
2952 *itersvp = newSVsv(cur);
6d3ca00e 2953 SvREFCNT_dec(oldsv);
b552b52c
DM
2954 }
2955 if (strEQ(SvPVX_const(cur), max))
2956 sv_setiv(cur, 0); /* terminate next time */
2957 else
2958 sv_inc(cur);
2959 break;
2960 }
a48ce6be 2961
fcef60b4
DM
2962 case CXt_LOOP_LAZYIV: /* integer increment */
2963 {
2964 IV cur = cx->blk_loop.state_u.lazyiv.cur;
5d9574c1 2965 if (UNLIKELY(cur > cx->blk_loop.state_u.lazyiv.end))
8a1f10dd 2966 goto retno;
7f61b687 2967
fcef60b4 2968 oldsv = *itersvp;
6d3ca00e
DM
2969 /* see NB comment above */
2970 if (oldsv && LIKELY(SvREFCNT(oldsv) == 1 && !SvMAGICAL(oldsv))) {
eaa5c2d6 2971 /* safe to reuse old SV */
47b96a1e
DM
2972
2973 if ( (SvFLAGS(oldsv) & (SVTYPEMASK|SVf_THINKFIRST|SVf_IVisUV))
2974 == SVt_IV)
2975 {
2976 /* Cheap SvIOK_only().
2977 * Assert that flags which SvIOK_only() would test or
2978 * clear can't be set, because we're SVt_IV */
2979 assert(!(SvFLAGS(oldsv) &
2980 (SVf_OOK|SVf_UTF8|(SVf_OK & ~(SVf_IOK|SVp_IOK)))));
2981 SvFLAGS(oldsv) |= (SVf_IOK|SVp_IOK);
2982 /* SvIV_set() where sv_any points to head */
2983 oldsv->sv_u.svu_iv = cur;
2984
2985 }
2986 else
2987 sv_setiv(oldsv, cur);
eaa5c2d6 2988 }
1c846c1f 2989 else
eaa5c2d6
GA
2990 {
2991 /* we need a fresh SV every time so that loop body sees a
2992 * completely new SV for closures/references to work as they
2993 * used to */
fcef60b4 2994 *itersvp = newSViv(cur);
6d3ca00e 2995 SvREFCNT_dec(oldsv);
eaa5c2d6 2996 }
a2309040 2997
5d9574c1 2998 if (UNLIKELY(cur == IV_MAX)) {
cdc1aa42
NC
2999 /* Handle end of range at IV_MAX */
3000 cx->blk_loop.state_u.lazyiv.end = IV_MIN;
3001 } else
3002 ++cx->blk_loop.state_u.lazyiv.cur;
a48ce6be 3003 break;
fcef60b4 3004 }
a48ce6be 3005
93661e56
DM
3006 case CXt_LOOP_LIST: /* for (1,2,3) */
3007
3008 assert(OPpITER_REVERSED == 2); /* so inc becomes -1 or 1 */
3009 inc = 1 - (PL_op->op_private & OPpITER_REVERSED);
3010 ix = (cx->blk_loop.state_u.stack.ix += inc);
3011 if (UNLIKELY(inc > 0
3012 ? ix > cx->blk_oldsp
3013 : ix <= cx->blk_loop.state_u.stack.basesp)
3014 )
8a1f10dd 3015 goto retno;
93661e56
DM
3016
3017 sv = PL_stack_base[ix];
3018 av = NULL;
3019 goto loop_ary_common;
3020
3021 case CXt_LOOP_ARY: /* for (@ary) */
3022
3023 av = cx->blk_loop.state_u.ary.ary;
3024 inc = 1 - (PL_op->op_private & OPpITER_REVERSED);
3025 ix = (cx->blk_loop.state_u.ary.ix += inc);
3026 if (UNLIKELY(inc > 0
3027 ? ix > AvFILL(av)
3028 : ix < 0)
3029 )
8a1f10dd 3030 goto retno;
de080daa 3031
9d1ee8e0 3032 if (UNLIKELY(SvRMAGICAL(av))) {
a8a20bb6
DM
3033 SV * const * const svp = av_fetch(av, ix, FALSE);
3034 sv = svp ? *svp : NULL;
3035 }
3036 else {
3037 sv = AvARRAY(av)[ix];
de080daa 3038 }
ef3e5ea9 3039
93661e56
DM
3040 loop_ary_common:
3041
d39c26a6
FC
3042 if (UNLIKELY(cx->cx_type & CXp_FOR_LVREF)) {
3043 SvSetMagicSV(*itersvp, sv);
3044 break;
3045 }
3046
5d9574c1
DM
3047 if (LIKELY(sv)) {
3048 if (UNLIKELY(SvIS_FREED(sv))) {
f38aa882
DM
3049 *itersvp = NULL;
3050 Perl_croak(aTHX_ "Use of freed value in iteration");
3051 }
60779a30 3052 if (SvPADTMP(sv)) {
8e079c2a 3053 sv = newSVsv(sv);
60779a30 3054 }
8e079c2a
FC
3055 else {
3056 SvTEMP_off(sv);
3057 SvREFCNT_inc_simple_void_NN(sv);
3058 }
de080daa 3059 }
93661e56 3060 else if (av) {
199f858d 3061 sv = newSVavdefelem(av, ix, 0);
de080daa 3062 }
a600f7e6
FC
3063 else
3064 sv = &PL_sv_undef;
a0d0e21e 3065
de080daa
DM
3066 oldsv = *itersvp;
3067 *itersvp = sv;
3068 SvREFCNT_dec(oldsv);
de080daa 3069 break;
a48ce6be
DM
3070
3071 default:
3072 DIE(aTHX_ "panic: pp_iter, type=%u", CxTYPE(cx));
3073 }
8a1f10dd 3074
7c114860
DM
3075 /* Bypass pushing &PL_sv_yes and calling pp_and(); instead
3076 * jump straight to the AND op's op_other */
3077 assert(PL_op->op_next->op_type == OP_AND);
3078 assert(PL_op->op_next->op_ppaddr == Perl_pp_and);
3079 return cLOGOPx(PL_op->op_next)->op_other;
3080
3081 retno:
3082 /* Bypass pushing &PL_sv_no and calling pp_and(); instead
3083 * jump straight to the AND op's op_next */
3084 assert(PL_op->op_next->op_type == OP_AND);
3085 assert(PL_op->op_next->op_ppaddr == Perl_pp_and);
8a1f10dd 3086 /* pp_enteriter should have pre-extended the stack */
87058c31 3087 EXTEND_SKIP(PL_stack_sp, 1);
7c114860
DM
3088 /* we only need this for the rare case where the OP_AND isn't
3089 * in void context, e.g. $x = do { for (..) {...} };
3090 * but its cheaper to just push it rather than testing first
3091 */
3092 *++PL_stack_sp = &PL_sv_no;
3093 return PL_op->op_next->op_next;
a0d0e21e
LW
3094}
3095
7c114860 3096
ef07e810
DM
3097/*
3098A description of how taint works in pattern matching and substitution.
3099
284167a5
SM
3100This is all conditional on NO_TAINT_SUPPORT not being defined. Under
3101NO_TAINT_SUPPORT, taint-related operations should become no-ops.
3102
4e19c54b 3103While the pattern is being assembled/concatenated and then compiled,
284167a5
SM
3104PL_tainted will get set (via TAINT_set) if any component of the pattern
3105is tainted, e.g. /.*$tainted/. At the end of pattern compilation,
3106the RXf_TAINTED flag is set on the pattern if PL_tainted is set (via
1738e041
DM
3107TAINT_get). It will also be set if any component of the pattern matches
3108based on locale-dependent behavior.
ef07e810 3109
0ab462a6
DM
3110When the pattern is copied, e.g. $r = qr/..../, the SV holding the ref to
3111the pattern is marked as tainted. This means that subsequent usage, such
284167a5
SM
3112as /x$r/, will set PL_tainted using TAINT_set, and thus RXf_TAINTED,
3113on the new pattern too.
ef07e810 3114
272d35c9 3115RXf_TAINTED_SEEN is used post-execution by the get magic code
ef07e810
DM
3116of $1 et al to indicate whether the returned value should be tainted.
3117It is the responsibility of the caller of the pattern (i.e. pp_match,
3118pp_subst etc) to set this flag for any other circumstances where $1 needs
3119to be tainted.
3120
3121The taint behaviour of pp_subst (and pp_substcont) is quite complex.
3122
3123There are three possible sources of taint
3124 * the source string
3125 * the pattern (both compile- and run-time, RXf_TAINTED / RXf_TAINTED_SEEN)
3126 * the replacement string (or expression under /e)
3127
3128There are four destinations of taint and they are affected by the sources
3129according to the rules below:
3130
3131 * the return value (not including /r):
3132 tainted by the source string and pattern, but only for the
3133 number-of-iterations case; boolean returns aren't tainted;
3134 * the modified string (or modified copy under /r):
3135 tainted by the source string, pattern, and replacement strings;
3136 * $1 et al:
3137 tainted by the pattern, and under 'use re "taint"', by the source
3138 string too;
3139 * PL_taint - i.e. whether subsequent code (e.g. in a /e block) is tainted:
3140 should always be unset before executing subsequent code.
3141
3142The overall action of pp_subst is:
3143
3144 * at the start, set bits in rxtainted indicating the taint status of
3145 the various sources.
3146
3147 * After each pattern execution, update the SUBST_TAINT_PAT bit in
3148 rxtainted if RXf_TAINTED_SEEN has been set, to indicate that the
3149 pattern has subsequently become tainted via locale ops.
3150
3151 * If control is being passed to pp_substcont to execute a /e block,
3152 save rxtainted in the CXt_SUBST block, for future use by
3153 pp_substcont.
3154
3155 * Whenever control is being returned to perl code (either by falling
3156 off the "end" of pp_subst/pp_substcont, or by entering a /e block),
3157 use the flag bits in rxtainted to make all the appropriate types of
0ab462a6
DM
3158 destination taint visible; e.g. set RXf_TAINTED_SEEN so that $1
3159 et al will appear tainted.
ef07e810
DM
3160
3161pp_match is just a simpler version of the above.
3162
3163*/
3164
a0d0e21e
LW
3165PP(pp_subst)
3166{
20b7effb 3167 dSP; dTARG;
eb578fdb 3168 PMOP *pm = cPMOP;
a0d0e21e 3169 PMOP *rpm = pm;
eb578fdb 3170 char *s;
a0d0e21e 3171 char *strend;
5c144d81 3172 const char *c;
a0d0e21e 3173 STRLEN clen;
3c6ef0a5
FC
3174 SSize_t iters = 0;
3175 SSize_t maxiters;
a0d0e21e 3176 bool once;
ef07e810
DM
3177 U8 rxtainted = 0; /* holds various SUBST_TAINT_* flag bits.
3178 See "how taint works" above */
a0d0e21e 3179 char *orig;
1ed74d04 3180 U8 r_flags;
eb578fdb 3181 REGEXP *rx = PM_GETRE(pm);
196a02af 3182 regexp *prog = ReANY(rx);
a0d0e21e
LW
3183 STRLEN len;
3184 int force_on_match = 0;
0bcc34c2 3185 const I32 oldsave = PL_savestack_ix;
792b2c16 3186 STRLEN slen;
26a74523 3187 bool doutf8 = FALSE; /* whether replacement is in utf8 */
db2c6cb3 3188#ifdef PERL_ANY_COW
106d9a13 3189 bool was_cow;
ed252734 3190#endif
a0714e2c 3191 SV *nsv = NULL;
b770e143 3192 /* known replacement string? */
eb578fdb 3193 SV *dstr = (pm->op_pmflags & PMf_CONST) ? POPs : NULL;
a0d0e21e 3194
f410a211
NC
3195 PERL_ASYNC_CHECK();
3196
533c011a 3197 if (PL_op->op_flags & OPf_STACKED)
a0d0e21e
LW
3198 TARG = POPs;
3199 else {
9399c607
DM
3200 if (ARGTARG)
3201 GETTARGET;
3202 else {
3203 TARG = DEFSV;
3204 }
a0d0e21e 3205 EXTEND(SP,1);
1c846c1f 3206 }
d9f424b2 3207
64534138 3208 SvGETMAGIC(TARG); /* must come before cow check */
db2c6cb3 3209#ifdef PERL_ANY_COW
106d9a13
DM
3210 /* note that a string might get converted to COW during matching */
3211 was_cow = cBOOL(SvIsCOW(TARG));
ed252734 3212#endif
d13a5d3b
TC
3213 if (!(rpm->op_pmflags & PMf_NONDESTRUCT)) {
3214#ifndef PERL_ANY_COW
3215 if (SvIsCOW(TARG))
3216 sv_force_normal_flags(TARG,0);
3217#endif
3218 if ((SvREADONLY(TARG)
3219 || ( ((SvTYPE(TARG) == SVt_PVGV && isGV_with_GP(TARG))
3220 || SvTYPE(TARG) > SVt_PVLV)
3221 && !(SvTYPE(TARG) == SVt_PVGV && SvFAKE(TARG)))))
3222 Perl_croak_no_modify();
3223 }
8ec5e241
NIS
3224 PUTBACK;
3225
6ac6605d
DM
3226 orig = SvPV_nomg(TARG, len);
3227 /* note we don't (yet) force the var into being a string; if we fail
92711104 3228 * to match, we leave as-is; on successful match however, we *will*
6ac6605d 3229 * coerce into a string, then repeat the match */
4499db73 3230 if (!SvPOKp(TARG) || SvTYPE(TARG) == SVt_PVGV || SvVOK(TARG))
a0d0e21e 3231 force_on_match = 1;
20be6587
DM
3232
3233 /* only replace once? */
3234 once = !(rpm->op_pmflags & PMf_GLOBAL);
3235
ef07e810 3236 /* See "how taint works" above */
284167a5 3237 if (TAINTING_get) {
20be6587
DM
3238 rxtainted = (
3239 (SvTAINTED(TARG) ? SUBST_TAINT_STR : 0)
196a02af 3240 | (RXp_ISTAINTED(prog) ? SUBST_TAINT_PAT : 0)
20be6587
DM
3241 | ((pm->op_pmflags & PMf_RETAINT) ? SUBST_TAINT_RETAINT : 0)
3242 | ((once && !(rpm->op_pmflags & PMf_NONDESTRUCT))
3243 ? SUBST_TAINT_BOOLRET : 0));
3244 TAINT_NOT;
3245 }
a12c0f56 3246
a0d0e21e 3247 force_it:
6ac6605d
DM
3248 if (!pm || !orig)
3249 DIE(aTHX_ "panic: pp_subst, pm=%p, orig=%p", pm, orig);
a0d0e21e 3250
6ac6605d
DM
3251 strend = orig + len;
3252 slen = DO_UTF8(TARG) ? utf8_length((U8*)orig, (U8*)strend) : len;
792b2c16
JH
3253 maxiters = 2 * slen + 10; /* We can match twice at each
3254 position, once with zero-length,
3255 second time with non-zero. */
a0d0e21e 3256
794826f4 3257 /* handle the empty pattern */
196a02af 3258 if (!RX_PRELEN(rx) && PL_curpm && !prog->mother_re) {
5585e758
YO
3259 if (PL_curpm == PL_reg_curpm) {
3260 if (PL_curpm_under) {
3261 if (PL_curpm_under == PL_reg_curpm) {
3262 Perl_croak(aTHX_ "Infinite recursion via empty pattern");
3263 } else {
3264 pm = PL_curpm_under;
3265 }
3266 }
3267 } else {
3268 pm = PL_curpm;
3269 }
3270 rx = PM_GETRE(pm);
196a02af 3271 prog = ReANY(rx);
a0d0e21e 3272 }
6502e081 3273
6e240d0b 3274#ifdef PERL_SAWAMPERSAND
196a02af 3275 r_flags = ( RXp_NPARENS(prog)
6502e081 3276 || PL_sawampersand
196a02af 3277 || (RXp_EXTFLAGS(prog) & (RXf_EVAL_SEEN|RXf_PMf_KEEPCOPY))
5b0e71e9 3278 || (rpm->op_pmflags & PMf_KEEPCOPY)
6502e081
DM
3279 )
3280 ? REXEC_COPY_STR
3281 : 0;
6e240d0b
FC
3282#else
3283 r_flags = REXEC_COPY_STR;
3284#endif
7fba1cd6 3285
0395280b 3286 if (!CALLREGEXEC(rx, orig, strend, orig, 0, TARG, NULL, r_flags))
8b64c330 3287 {
5e79dfb9
DM
3288 SPAGAIN;
3289 PUSHs(rpm->op_pmflags & PMf_NONDESTRUCT ? TARG : &PL_sv_no);
3290 LEAVE_SCOPE(oldsave);
3291 RETURN;
3292 }
1754320d
FC
3293 PL_curpm = pm;
3294
71be2cbc 3295 /* known replacement string? */
f272994b 3296 if (dstr) {
8514a05a
JH
3297 /* replacement needing upgrading? */
3298 if (DO_UTF8(TARG) && !doutf8) {
db79b45b 3299 nsv = sv_newmortal();
4a176938 3300 SvSetSV(nsv, dstr);
8df0e7a2 3301 sv_utf8_upgrade(nsv);
5c144d81 3302 c = SvPV_const(nsv, clen);
4a176938
JH
3303 doutf8 = TRUE;
3304 }
3305 else {
5c144d81 3306 c = SvPV_const(dstr, clen);
4a176938 3307 doutf8 = DO_UTF8(dstr);
8514a05a 3308 }
bb933b9b
FC
3309
3310 if (SvTAINTED(dstr))
3311 rxtainted |= SUBST_TAINT_REPL;
f272994b
A
3312 }
3313 else {
6136c704 3314 c = NULL;
f272994b
A
3315 doutf8 = FALSE;
3316 }
3317
71be2cbc 3318 /* can do inplace substitution? */
ed252734 3319 if (c
db2c6cb3 3320#ifdef PERL_ANY_COW
106d9a13 3321 && !was_cow
ed252734 3322#endif
196a02af 3323 && (I32)clen <= RXp_MINLENRET(prog)
9cefd268
FC
3324 && ( once
3325 || !(r_flags & REXEC_COPY_STR)
196a02af 3326 || (!SvGMAGICAL(dstr) && !(RXp_EXTFLAGS(prog) & RXf_EVAL_SEEN))
9cefd268 3327 )
196a02af 3328 && !(RXp_EXTFLAGS(prog) & RXf_NO_INPLACE_SUBST)
8ca8a454
NC
3329 && (!doutf8 || SvUTF8(TARG))
3330 && !(rpm->op_pmflags & PMf_NONDESTRUCT))
8b030b38 3331 {
ec911639 3332
db2c6cb3 3333#ifdef PERL_ANY_COW
106d9a13 3334 /* string might have got converted to COW since we set was_cow */
ed252734 3335 if (SvIsCOW(TARG)) {
f7a8268c 3336 if (!force_on_match)
ed252734 3337 goto have_a_cow;
f7a8268c 3338 assert(SvVOK(TARG));
ed252734
NC
3339 }
3340#endif
71be2cbc 3341 if (force_on_match) {
6ac6605d
DM
3342 /* redo the first match, this time with the orig var
3343 * forced into being a string */
71be2cbc 3344 force_on_match = 0;
6ac6605d 3345 orig = SvPV_force_nomg(TARG, len);
71be2cbc
PP
3346 goto force_it;
3347 }
39b40493 3348
71be2cbc 3349 if (once) {
c67ab8f2 3350 char *d, *m;
196a02af 3351 if (RXp_MATCH_TAINTED(prog)) /* run time pattern taint, eg locale */
20be6587 3352 rxtainted |= SUBST_TAINT_PAT;
196a02af
DM
3353 m = orig + RXp_OFFS(prog)[0].start;
3354 d = orig + RXp_OFFS(prog)[0].end;
71be2cbc
PP
3355 s = orig;
3356 if (m - s > strend - d) { /* faster to shorten from end */
2ec7214c 3357 I32 i;
71be2cbc
PP
3358 if (clen) {
3359 Copy(c, m, clen, char);
3360 m += clen;
a0d0e21e 3361 }
71be2cbc
PP
3362 i = strend - d;
3363 if (i > 0) {
3364 Move(d, m, i, char);
3365 m += i;
a0d0e21e 3366 }
71be2cbc
PP
3367 *m = '\0';
3368 SvCUR_set(TARG, m - s);
3369 }
2ec7214c
DM
3370 else { /* faster from front */
3371 I32 i = m - s;
71be2cbc 3372 d -= clen;
2ec7214c
DM
3373 if (i > 0)
3374 Move(s, d - i, i, char);
71be2cbc 3375 sv_chop(TARG, d-i);
71be2cbc 3376 if (clen)
c947cd8d 3377 Copy(c, d, clen, char);
71be2cbc 3378 }
8ec5e241 3379 SPAGAIN;
8ca8a454 3380 PUSHs(&PL_sv_yes);
71be2cbc
PP
3381 }
3382 else {
c67ab8f2 3383 char *d, *m;
196a02af 3384 d = s = RXp_OFFS(prog)[0].start + orig;
71be2cbc 3385 do {
2b25edcf 3386 I32 i;
5d9574c1 3387 if (UNLIKELY(iters++ > maxiters))
cea2e8a9 3388 DIE(aTHX_ "Substitution loop");
196a02af
DM
3389 /* run time pattern taint, eg locale */
3390 if (UNLIKELY(RXp_MATCH_TAINTED(prog)))
20be6587 3391 rxtainted |= SUBST_TAINT_PAT;
196a02af 3392 m = RXp_OFFS(prog)[0].start + orig;
155aba94 3393 if ((i = m - s)) {
71be2cbc
PP
3394 if (s != d)
3395 Move(s, d, i, char);
3396 d += i;
a0d0e21e 3397 }
71be2cbc
PP
3398 if (clen) {
3399 Copy(c, d, clen, char);
3400 d += clen;
3401 }
196a02af 3402 s = RXp_OFFS(prog)[0].end + orig;
7ce41e5c
FC
3403 } while (CALLREGEXEC(rx, s, strend, orig,
3404 s == m, /* don't match same null twice */
f722798b 3405 TARG, NULL,
d5e7783a 3406 REXEC_NOT_FIRST|REXEC_IGNOREPOS|REXEC_FAIL_ON_UNDERFLOW));
71be2cbc 3407 if (s != d) {
2b25edcf 3408 I32 i = strend - s;
aa07b2f6 3409 SvCUR_set(TARG, d - SvPVX_const(TARG) + i);
71be2cbc 3410 Move(s, d, i+1, char); /* include the NUL */
a0d0e21e 3411 }
8ec5e241 3412 SPAGAIN;
7b394f12
DM
3413 if (PL_op->op_private & OPpTRUEBOOL)
3414 PUSHs(iters ? &PL_sv_yes : &PL_sv_zero);
3415 else
3416 mPUSHi(iters);
a0d0e21e
LW
3417 }
3418 }
ff6e92e8 3419 else {
1754320d 3420 bool first;
c67ab8f2 3421 char *m;
1754320d 3422 SV *repl;
a0d0e21e 3423 if (force_on_match) {
6ac6605d
DM
3424 /* redo the first match, this time with the orig var
3425 * forced into being a string */
a0d0e21e 3426 force_on_match = 0;
0c1438a1
NC
3427 if (rpm->op_pmflags & PMf_NONDESTRUCT) {
3428 /* I feel that it should be possible to avoid this mortal copy
3429 given that the code below copies into a new destination.
3430 However, I suspect it isn't worth the complexity of
3431 unravelling the C<goto force_it> for the small number of
3432 cases where it would be viable to drop into the copy code. */
3433 TARG = sv_2mortal(newSVsv(TARG));
3434 }
6ac6605d 3435 orig = SvPV_force_nomg(TARG, len);
a0d0e21e
LW
3436 goto force_it;
3437 }
db2c6cb3 3438#ifdef PERL_ANY_COW
ed252734
NC
3439 have_a_cow:
3440#endif
196a02af 3441 if (RXp_MATCH_TAINTED(prog)) /* run time pattern taint, eg locale */
20be6587 3442 rxtainted |= SUBST_TAINT_PAT;
1754320d 3443 repl = dstr;
196a02af 3444 s = RXp_OFFS(prog)[0].start + orig;
0395280b
DM
3445 dstr = newSVpvn_flags(orig, s-orig,
3446 SVs_TEMP | (DO_UTF8(TARG) ? SVf_UTF8 : 0));
a0d0e21e 3447 if (!c) {
eb578fdb 3448 PERL_CONTEXT *cx;
8ec5e241 3449 SPAGAIN;
0395280b 3450 m = orig;
20be6587
DM
3451 /* note that a whole bunch of local vars are saved here for
3452 * use by pp_substcont: here's a list of them in case you're
3453 * searching for places in this sub that uses a particular var:
3454 * iters maxiters r_flags oldsave rxtainted orig dstr targ
3455 * s m strend rx once */
490576d1 3456 CX_PUSHSUBST(cx);
20e98b0f 3457 RETURNOP(cPMOP->op_pmreplrootu.op_pmreplroot);
a0d0e21e 3458 }
1754320d 3459 first = TRUE;
a0d0e21e 3460 do {
5d9574c1 3461 if (UNLIKELY(iters++ > maxiters))
cea2e8a9 3462 DIE(aTHX_ "Substitution loop");
196a02af 3463 if (UNLIKELY(RXp_MATCH_TAINTED(prog)))
20be6587 3464 rxtainted |= SUBST_TAINT_PAT;
196a02af 3465 if (RXp_MATCH_COPIED(prog) && RXp_SUBBEG(prog) != orig) {
c67ab8f2
DM
3466 char *old_s = s;
3467 char *old_orig = orig;
196a02af 3468 assert(RXp_SUBOFFSET(prog) == 0);
c67ab8f2 3469
196a02af 3470 orig = RXp_SUBBEG(prog);
c67ab8f2
DM
3471 s = orig + (old_s - old_orig);
3472 strend = s + (strend - old_s);
a0d0e21e 3473 }
196a02af 3474 m = RXp_OFFS(prog)[0].start + orig;
64534138 3475 sv_catpvn_nomg_maybeutf8(dstr, s, m - s, DO_UTF8(TARG));
196a02af 3476 s = RXp_OFFS(prog)[0].end + orig;
1754320d
FC
3477 if (first) {
3478 /* replacement already stringified */
3479 if (clen)
64534138 3480 sv_catpvn_nomg_maybeutf8(dstr, c, clen, doutf8);
1754320d
FC
3481 first = FALSE;
3482 }
3483 else {
8df0e7a2 3484 sv_catsv(dstr, repl);
5d9574c1 3485 if (UNLIKELY(SvTAINTED(repl)))
bb933b9b 3486 rxtainted |= SUBST_TAINT_REPL;
1754320d 3487 }
a0d0e21e
LW
3488 if (once)
3489 break;
ff27773b
KW
3490 } while (CALLREGEXEC(rx, s, strend, orig,
3491 s == m, /* Yields minend of 0 or 1 */
d5e7783a
DM
3492 TARG, NULL,
3493 REXEC_NOT_FIRST|REXEC_IGNOREPOS|REXEC_FAIL_ON_UNDERFLOW));
aba224f7 3494 assert(strend >= s);
64534138 3495 sv_catpvn_nomg_maybeutf8(dstr, s, strend - s, DO_UTF8(TARG));
748a9306 3496
8ca8a454
NC
3497 if (rpm->op_pmflags & PMf_NONDESTRUCT) {
3498 /* From here on down we're using the copy, and leaving the original
3499 untouched. */
3500 TARG = dstr;
3501 SPAGAIN;
3502 PUSHs(dstr);
3503 } else {
db2c6cb3 3504#ifdef PERL_ANY_COW
8ca8a454
NC
3505 /* The match may make the string COW. If so, brilliant, because
3506 that's just saved us one malloc, copy and free - the regexp has
3507 donated the old buffer, and we malloc an entirely new one, rather
3508 than the regexp malloc()ing a buffer and copying our original,
3509 only for us to throw it away here during the substitution. */
3510 if (SvIsCOW(TARG)) {
3511 sv_force_normal_flags(TARG, SV_COW_DROP_PV);
3512 } else
ed252734 3513#endif
8ca8a454
NC
3514 {
3515 SvPV_free(TARG);
3516 }
3517 SvPV_set(TARG, SvPVX(dstr));
3518 SvCUR_set(TARG, SvCUR(dstr));
3519 SvLEN_set(TARG, SvLEN(dstr));
64534138 3520 SvFLAGS(TARG) |= SvUTF8(dstr);
8ca8a454 3521 SvPV_set(dstr, NULL);
748a9306 3522
8ca8a454 3523 SPAGAIN;
3c6ef0a5 3524 mPUSHi(iters);
8ca8a454
NC
3525 }
3526 }
3527
3528 if (!(rpm->op_pmflags & PMf_NONDESTRUCT)) {
3529 (void)SvPOK_only_UTF8(TARG);
a0d0e21e 3530 }
20be6587 3531
ef07e810 3532 /* See "how taint works" above */
284167a5 3533 if (TAINTING_get) {
20be6587
DM
3534 if ((rxtainted & SUBST_TAINT_PAT) ||
3535 ((rxtainted & (SUBST_TAINT_STR|SUBST_TAINT_RETAINT)) ==
3536 (SUBST_TAINT_STR|SUBST_TAINT_RETAINT))
3537 )
196a02af 3538 (RXp_MATCH_TAINTED_on(prog)); /* taint $1 et al */
20be6587
DM
3539
3540 if (!(rxtainted & SUBST_TAINT_BOOLRET)
3541 && (rxtainted & (SUBST_TAINT_STR|SUBST_TAINT_PAT))
3542 )
3543 SvTAINTED_on(TOPs); /* taint return value */
3544 else
3545 SvTAINTED_off(TOPs); /* may have got tainted earlier */
3546
3547 /* needed for mg_set below */
284167a5
SM
3548 TAINT_set(
3549 cBOOL(rxtainted & (SUBST_TAINT_STR|SUBST_TAINT_PAT|SUBST_TAINT_REPL))
3550 );
20be6587
DM
3551 SvTAINT(TARG);
3552 }
3553 SvSETMAGIC(TARG); /* PL_tainted must be correctly set for this mg_set */
3554 TAINT_NOT;
f1a76097
DM
3555 LEAVE_SCOPE(oldsave);
3556 RETURN;
a0d0e21e
LW
3557}
3558
3559PP(pp_grepwhile)
3560{
20b7effb 3561 dSP;
f4c975aa 3562 dPOPss;
a0d0e21e 3563
f4c975aa 3564 if (SvTRUE_NN(sv))
3280af22
NIS
3565 PL_stack_base[PL_markstack_ptr[-1]++] = PL_stack_base[*PL_markstack_ptr];
3566 ++*PL_markstack_ptr;
b2a2a901 3567 FREETMPS;
d343c3ef 3568 LEAVE_with_name("grep_item"); /* exit inner scope */
a0d0e21e
LW
3569
3570 /* All done yet? */
5d9574c1 3571 if (UNLIKELY(PL_stack_base + *PL_markstack_ptr > SP)) {
a0d0e21e 3572 I32 items;
1c23e2bd 3573 const U8 gimme = GIMME_V;
a0d0e21e 3574
d343c3ef 3575 LEAVE_with_name("grep"); /* exit outer scope */
a0d0e21e 3576 (void)POPMARK; /* pop src */
3280af22 3577 items = --*PL_markstack_ptr - PL_markstack_ptr[-1];
a0d0e21e 3578 (void)POPMARK; /* pop dst */
3280af22 3579 SP = PL_stack_base + POPMARK; /* pop original mark */
54310121 3580 if (gimme == G_SCALAR) {
7b394f12
DM
3581 if (PL_op->op_private & OPpTRUEBOOL)
3582 XPUSHs(items ? &PL_sv_yes : &PL_sv_zero);
3583 else {
7cc47870
RGS
3584 dTARGET;
3585 XPUSHi(items);
7b394f12 3586 }
a0d0e21e 3587 }
54310121
PP
3588 else if (gimme == G_ARRAY)
3589 SP += items;
a0d0e21e
LW
3590 RETURN;
3591 }
3592 else {
3593 SV *src;
3594
d343c3ef 3595 ENTER_with_name("grep_item"); /* enter inner scope */
1d7c1841 3596 SAVEVPTR(PL_curpm);
a0d0e21e 3597
6cae08a8 3598 src = PL_stack_base[TOPMARK];
60779a30 3599 if (SvPADTMP(src)) {
6cae08a8 3600 src = PL_stack_base[TOPMARK] = sv_mortalcopy(src);
a0ed822e
FC
3601 PL_tmps_floor++;
3602 }
a0d0e21e 3603 SvTEMP_off(src);
ffd49c98 3604 DEFSV_set(src);
a0d0e21e
LW
3605
3606 RETURNOP(cLOGOP->op_other);
3607 }
3608}
3609
799da9d7 3610/* leave_adjust_stacks():
f7a874b8 3611 *
e02ce34b
DM
3612 * Process a scope's return args (in the range from_sp+1 .. PL_stack_sp),
3613 * positioning them at to_sp+1 onwards, and do the equivalent of a
3614 * FREEMPS and TAINT_NOT.
3615 *
f7a874b8
DM
3616 * Not intended to be called in void context.
3617 *
799da9d7
DM
3618 * When leaving a sub, eval, do{} or other scope, the things that need
3619 * doing to process the return args are:
f7a874b8 3620 * * in scalar context, only return the last arg (or PL_sv_undef if none);
799da9d7
DM
3621 * * for the types of return that return copies of their args (such
3622 * as rvalue sub return), make a mortal copy of every return arg,
3623 * except where we can optimise the copy away without it being
3624 * semantically visible;
3625 * * make sure that the arg isn't prematurely freed; in the case of an
3626 * arg not copied, this may involve mortalising it. For example, in
f7a874b8
DM
3627 * C<sub f { my $x = ...; $x }>, $x would be freed when we do
3628 * CX_LEAVE_SCOPE(cx) unless it's protected or copied.
3629 *
799da9d7
DM
3630 * What condition to use when deciding whether to pass the arg through