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4b88f280 1#line 2 "op.c"
a0d0e21e 2/* op.c
79072805 3 *
1129b882
NC
4 * Copyright (C) 1991, 1992, 1993, 1994, 1995, 1996, 1997, 1998, 1999, 2000,
5 * 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008 by Larry Wall and others
79072805
LW
6 *
7 * You may distribute under the terms of either the GNU General Public
8 * License or the Artistic License, as specified in the README file.
9 *
a0d0e21e
LW
10 */
11
12/*
4ac71550
TC
13 * 'You see: Mr. Drogo, he married poor Miss Primula Brandybuck. She was
14 * our Mr. Bilbo's first cousin on the mother's side (her mother being the
15 * youngest of the Old Took's daughters); and Mr. Drogo was his second
16 * cousin. So Mr. Frodo is his first *and* second cousin, once removed
17 * either way, as the saying is, if you follow me.' --the Gaffer
18 *
19 * [p.23 of _The Lord of the Rings_, I/i: "A Long-Expected Party"]
79072805
LW
20 */
21
166f8a29
DM
22/* This file contains the functions that create, manipulate and optimize
23 * the OP structures that hold a compiled perl program.
24 *
25 * A Perl program is compiled into a tree of OPs. Each op contains
26 * structural pointers (eg to its siblings and the next op in the
27 * execution sequence), a pointer to the function that would execute the
28 * op, plus any data specific to that op. For example, an OP_CONST op
29 * points to the pp_const() function and to an SV containing the constant
30 * value. When pp_const() is executed, its job is to push that SV onto the
31 * stack.
32 *
33 * OPs are mainly created by the newFOO() functions, which are mainly
34 * called from the parser (in perly.y) as the code is parsed. For example
35 * the Perl code $a + $b * $c would cause the equivalent of the following
36 * to be called (oversimplifying a bit):
37 *
38 * newBINOP(OP_ADD, flags,
39 * newSVREF($a),
40 * newBINOP(OP_MULTIPLY, flags, newSVREF($b), newSVREF($c))
41 * )
42 *
43 * Note that during the build of miniperl, a temporary copy of this file
44 * is made, called opmini.c.
45 */
ccfc67b7 46
61b743bb
DM
47/*
48Perl's compiler is essentially a 3-pass compiler with interleaved phases:
49
50 A bottom-up pass
51 A top-down pass
52 An execution-order pass
53
54The bottom-up pass is represented by all the "newOP" routines and
55the ck_ routines. The bottom-upness is actually driven by yacc.
56So at the point that a ck_ routine fires, we have no idea what the
57context is, either upward in the syntax tree, or either forward or
58backward in the execution order. (The bottom-up parser builds that
59part of the execution order it knows about, but if you follow the "next"
60links around, you'll find it's actually a closed loop through the
ef9da979 61top level node.)
61b743bb
DM
62
63Whenever the bottom-up parser gets to a node that supplies context to
64its components, it invokes that portion of the top-down pass that applies
65to that part of the subtree (and marks the top node as processed, so
66if a node further up supplies context, it doesn't have to take the
67plunge again). As a particular subcase of this, as the new node is
68built, it takes all the closed execution loops of its subcomponents
69and links them into a new closed loop for the higher level node. But
70it's still not the real execution order.
71
72The actual execution order is not known till we get a grammar reduction
73to a top-level unit like a subroutine or file that will be called by
74"name" rather than via a "next" pointer. At that point, we can call
75into peep() to do that code's portion of the 3rd pass. It has to be
76recursive, but it's recursive on basic blocks, not on tree nodes.
77*/
78
06e0342d 79/* To implement user lexical pragmas, there needs to be a way at run time to
b3ca2e83
NC
80 get the compile time state of %^H for that block. Storing %^H in every
81 block (or even COP) would be very expensive, so a different approach is
82 taken. The (running) state of %^H is serialised into a tree of HE-like
83 structs. Stores into %^H are chained onto the current leaf as a struct
84 refcounted_he * with the key and the value. Deletes from %^H are saved
85 with a value of PL_sv_placeholder. The state of %^H at any point can be
86 turned back into a regular HV by walking back up the tree from that point's
06e0342d 87 leaf, ignoring any key you've already seen (placeholder or not), storing
b3ca2e83
NC
88 the rest into the HV structure, then removing the placeholders. Hence
89 memory is only used to store the %^H deltas from the enclosing COP, rather
90 than the entire %^H on each COP.
91
92 To cause actions on %^H to write out the serialisation records, it has
93 magic type 'H'. This magic (itself) does nothing, but its presence causes
94 the values to gain magic type 'h', which has entries for set and clear.
c28fe1ec 95 C<Perl_magic_sethint> updates C<PL_compiling.cop_hints_hash> with a store
34795b44 96 record, with deletes written by C<Perl_magic_clearhint>. C<SAVEHINTS>
c28fe1ec
NC
97 saves the current C<PL_compiling.cop_hints_hash> on the save stack, so that
98 it will be correctly restored when any inner compiling scope is exited.
b3ca2e83
NC
99*/
100
79072805 101#include "EXTERN.h"
864dbfa3 102#define PERL_IN_OP_C
79072805 103#include "perl.h"
77ca0c92 104#include "keywords.h"
2846acbf 105#include "feature.h"
74529a43 106#include "regcomp.h"
79072805 107
16c91539 108#define CALL_PEEP(o) PL_peepp(aTHX_ o)
1a0a2ba9 109#define CALL_RPEEP(o) PL_rpeepp(aTHX_ o)
16c91539 110#define CALL_OPFREEHOOK(o) if (PL_opfreehook) PL_opfreehook(aTHX_ o)
a2efc822 111
72621f84
DM
112/* remove any leading "empty" ops from the op_next chain whose first
113 * node's address is stored in op_p. Store the updated address of the
114 * first node in op_p.
115 */
116
117STATIC void
dc3bf405 118S_prune_chain_head(OP** op_p)
72621f84
DM
119{
120 while (*op_p
121 && ( (*op_p)->op_type == OP_NULL
122 || (*op_p)->op_type == OP_SCOPE
123 || (*op_p)->op_type == OP_SCALAR
124 || (*op_p)->op_type == OP_LINESEQ)
125 )
126 *op_p = (*op_p)->op_next;
127}
128
129
8be227ab
FC
130/* See the explanatory comments above struct opslab in op.h. */
131
7aef8e5b 132#ifdef PERL_DEBUG_READONLY_OPS
3107b51f
FC
133# define PERL_SLAB_SIZE 128
134# define PERL_MAX_SLAB_SIZE 4096
135# include <sys/mman.h>
7aef8e5b 136#endif
3107b51f 137
7aef8e5b 138#ifndef PERL_SLAB_SIZE
8be227ab 139# define PERL_SLAB_SIZE 64
7aef8e5b
FC
140#endif
141#ifndef PERL_MAX_SLAB_SIZE
e6cee8c0 142# define PERL_MAX_SLAB_SIZE 2048
7aef8e5b 143#endif
8be227ab
FC
144
145/* rounds up to nearest pointer */
7aef8e5b
FC
146#define SIZE_TO_PSIZE(x) (((x) + sizeof(I32 *) - 1)/sizeof(I32 *))
147#define DIFF(o,p) ((size_t)((I32 **)(p) - (I32**)(o)))
8be227ab
FC
148
149static OPSLAB *
150S_new_slab(pTHX_ size_t sz)
151{
7aef8e5b 152#ifdef PERL_DEBUG_READONLY_OPS
3107b51f
FC
153 OPSLAB *slab = (OPSLAB *) mmap(0, sz * sizeof(I32 *),
154 PROT_READ|PROT_WRITE,
155 MAP_ANON|MAP_PRIVATE, -1, 0);
156 DEBUG_m(PerlIO_printf(Perl_debug_log, "mapped %lu at %p\n",
157 (unsigned long) sz, slab));
158 if (slab == MAP_FAILED) {
159 perror("mmap failed");
160 abort();
161 }
162 slab->opslab_size = (U16)sz;
7aef8e5b 163#else
8be227ab 164 OPSLAB *slab = (OPSLAB *)PerlMemShared_calloc(sz, sizeof(I32 *));
7aef8e5b 165#endif
dc3bf405
BF
166#ifndef WIN32
167 /* The context is unused in non-Windows */
168 PERL_UNUSED_CONTEXT;
169#endif
8be227ab
FC
170 slab->opslab_first = (OPSLOT *)((I32 **)slab + sz - 1);
171 return slab;
172}
173
e7372881
FC
174/* requires double parens and aTHX_ */
175#define DEBUG_S_warn(args) \
176 DEBUG_S( \
177 PerlIO_printf(Perl_debug_log, "%s", SvPVx_nolen(Perl_mess args)) \
178 )
179
8be227ab
FC
180void *
181Perl_Slab_Alloc(pTHX_ size_t sz)
182{
8be227ab
FC
183 OPSLAB *slab;
184 OPSLAB *slab2;
185 OPSLOT *slot;
186 OP *o;
5cb52f30 187 size_t opsz, space;
8be227ab 188
2073970f
NC
189 /* We only allocate ops from the slab during subroutine compilation.
190 We find the slab via PL_compcv, hence that must be non-NULL. It could
191 also be pointing to a subroutine which is now fully set up (CvROOT()
192 pointing to the top of the optree for that sub), or a subroutine
193 which isn't using the slab allocator. If our sanity checks aren't met,
194 don't use a slab, but allocate the OP directly from the heap. */
8be227ab
FC
195 if (!PL_compcv || CvROOT(PL_compcv)
196 || (CvSTART(PL_compcv) && !CvSLABBED(PL_compcv)))
29e61fd9
DM
197 {
198 o = (OP*)PerlMemShared_calloc(1, sz);
199 goto gotit;
200 }
8be227ab 201
2073970f
NC
202 /* While the subroutine is under construction, the slabs are accessed via
203 CvSTART(), to avoid needing to expand PVCV by one pointer for something
204 unneeded at runtime. Once a subroutine is constructed, the slabs are
205 accessed via CvROOT(). So if CvSTART() is NULL, no slab has been
206 allocated yet. See the commit message for 8be227ab5eaa23f2 for more
207 details. */
208 if (!CvSTART(PL_compcv)) {
8be227ab
FC
209 CvSTART(PL_compcv) =
210 (OP *)(slab = S_new_slab(aTHX_ PERL_SLAB_SIZE));
211 CvSLABBED_on(PL_compcv);
212 slab->opslab_refcnt = 2; /* one for the CV; one for the new OP */
213 }
214 else ++(slab = (OPSLAB *)CvSTART(PL_compcv))->opslab_refcnt;
215
5cb52f30
FC
216 opsz = SIZE_TO_PSIZE(sz);
217 sz = opsz + OPSLOT_HEADER_P;
8be227ab 218
2073970f
NC
219 /* The slabs maintain a free list of OPs. In particular, constant folding
220 will free up OPs, so it makes sense to re-use them where possible. A
221 freed up slot is used in preference to a new allocation. */
8be227ab
FC
222 if (slab->opslab_freed) {
223 OP **too = &slab->opslab_freed;
224 o = *too;
eb212a1c 225 DEBUG_S_warn((aTHX_ "found free op at %p, slab %p", (void*)o, (void*)slab));
8be227ab 226 while (o && DIFF(OpSLOT(o), OpSLOT(o)->opslot_next) < sz) {
e7372881 227 DEBUG_S_warn((aTHX_ "Alas! too small"));
8be227ab 228 o = *(too = &o->op_next);
eb212a1c 229 if (o) { DEBUG_S_warn((aTHX_ "found another free op at %p", (void*)o)); }
8be227ab
FC
230 }
231 if (o) {
232 *too = o->op_next;
5cb52f30 233 Zero(o, opsz, I32 *);
8be227ab 234 o->op_slabbed = 1;
29e61fd9 235 goto gotit;
8be227ab
FC
236 }
237 }
238
7aef8e5b 239#define INIT_OPSLOT \
8be227ab
FC
240 slot->opslot_slab = slab; \
241 slot->opslot_next = slab2->opslab_first; \
242 slab2->opslab_first = slot; \
243 o = &slot->opslot_op; \
244 o->op_slabbed = 1
245
246 /* The partially-filled slab is next in the chain. */
247 slab2 = slab->opslab_next ? slab->opslab_next : slab;
248 if ((space = DIFF(&slab2->opslab_slots, slab2->opslab_first)) < sz) {
249 /* Remaining space is too small. */
250
8be227ab
FC
251 /* If we can fit a BASEOP, add it to the free chain, so as not
252 to waste it. */
253 if (space >= SIZE_TO_PSIZE(sizeof(OP)) + OPSLOT_HEADER_P) {
254 slot = &slab2->opslab_slots;
255 INIT_OPSLOT;
256 o->op_type = OP_FREED;
257 o->op_next = slab->opslab_freed;
258 slab->opslab_freed = o;
259 }
260
261 /* Create a new slab. Make this one twice as big. */
262 slot = slab2->opslab_first;
263 while (slot->opslot_next) slot = slot->opslot_next;
af7751f6
FC
264 slab2 = S_new_slab(aTHX_
265 (DIFF(slab2, slot)+1)*2 > PERL_MAX_SLAB_SIZE
e6cee8c0 266 ? PERL_MAX_SLAB_SIZE
af7751f6 267 : (DIFF(slab2, slot)+1)*2);
9963ffa2
FC
268 slab2->opslab_next = slab->opslab_next;
269 slab->opslab_next = slab2;
8be227ab
FC
270 }
271 assert(DIFF(&slab2->opslab_slots, slab2->opslab_first) >= sz);
272
273 /* Create a new op slot */
274 slot = (OPSLOT *)((I32 **)slab2->opslab_first - sz);
275 assert(slot >= &slab2->opslab_slots);
51c777ca
FC
276 if (DIFF(&slab2->opslab_slots, slot)
277 < SIZE_TO_PSIZE(sizeof(OP)) + OPSLOT_HEADER_P)
278 slot = &slab2->opslab_slots;
8be227ab 279 INIT_OPSLOT;
eb212a1c 280 DEBUG_S_warn((aTHX_ "allocating op at %p, slab %p", (void*)o, (void*)slab));
29e61fd9
DM
281
282 gotit:
283 /* lastsib == 1, op_sibling == 0 implies a solitary unattached op */
284 o->op_lastsib = 1;
285 assert(!o->op_sibling);
286
8be227ab
FC
287 return (void *)o;
288}
289
7aef8e5b 290#undef INIT_OPSLOT
8be227ab 291
7aef8e5b 292#ifdef PERL_DEBUG_READONLY_OPS
3107b51f
FC
293void
294Perl_Slab_to_ro(pTHX_ OPSLAB *slab)
295{
296 PERL_ARGS_ASSERT_SLAB_TO_RO;
297
298 if (slab->opslab_readonly) return;
299 slab->opslab_readonly = 1;
300 for (; slab; slab = slab->opslab_next) {
301 /*DEBUG_U(PerlIO_printf(Perl_debug_log,"mprotect ->ro %lu at %p\n",
302 (unsigned long) slab->opslab_size, slab));*/
303 if (mprotect(slab, slab->opslab_size * sizeof(I32 *), PROT_READ))
304 Perl_warn(aTHX_ "mprotect for %p %lu failed with %d", slab,
305 (unsigned long)slab->opslab_size, errno);
306 }
307}
308
7bbbc3c0
NC
309void
310Perl_Slab_to_rw(pTHX_ OPSLAB *const slab)
3107b51f 311{
3107b51f
FC
312 OPSLAB *slab2;
313
314 PERL_ARGS_ASSERT_SLAB_TO_RW;
315
3107b51f
FC
316 if (!slab->opslab_readonly) return;
317 slab2 = slab;
318 for (; slab2; slab2 = slab2->opslab_next) {
319 /*DEBUG_U(PerlIO_printf(Perl_debug_log,"mprotect ->rw %lu at %p\n",
320 (unsigned long) size, slab2));*/
321 if (mprotect((void *)slab2, slab2->opslab_size * sizeof(I32 *),
322 PROT_READ|PROT_WRITE)) {
323 Perl_warn(aTHX_ "mprotect RW for %p %lu failed with %d", slab,
324 (unsigned long)slab2->opslab_size, errno);
325 }
326 }
327 slab->opslab_readonly = 0;
328}
329
330#else
9e4d7a13 331# define Slab_to_rw(op) NOOP
3107b51f
FC
332#endif
333
8be227ab
FC
334/* This cannot possibly be right, but it was copied from the old slab
335 allocator, to which it was originally added, without explanation, in
336 commit 083fcd5. */
7aef8e5b 337#ifdef NETWARE
8be227ab 338# define PerlMemShared PerlMem
7aef8e5b 339#endif
8be227ab
FC
340
341void
342Perl_Slab_Free(pTHX_ void *op)
343{
344 OP * const o = (OP *)op;
345 OPSLAB *slab;
346
347 PERL_ARGS_ASSERT_SLAB_FREE;
348
349 if (!o->op_slabbed) {
90840c5d
RU
350 if (!o->op_static)
351 PerlMemShared_free(op);
8be227ab
FC
352 return;
353 }
354
355 slab = OpSLAB(o);
356 /* If this op is already freed, our refcount will get screwy. */
357 assert(o->op_type != OP_FREED);
358 o->op_type = OP_FREED;
359 o->op_next = slab->opslab_freed;
360 slab->opslab_freed = o;
eb212a1c 361 DEBUG_S_warn((aTHX_ "free op at %p, recorded in slab %p", (void*)o, (void*)slab));
8be227ab
FC
362 OpslabREFCNT_dec_padok(slab);
363}
364
365void
366Perl_opslab_free_nopad(pTHX_ OPSLAB *slab)
367{
8be227ab
FC
368 const bool havepad = !!PL_comppad;
369 PERL_ARGS_ASSERT_OPSLAB_FREE_NOPAD;
370 if (havepad) {
371 ENTER;
372 PAD_SAVE_SETNULLPAD();
373 }
374 opslab_free(slab);
375 if (havepad) LEAVE;
376}
377
378void
379Perl_opslab_free(pTHX_ OPSLAB *slab)
380{
381 OPSLAB *slab2;
382 PERL_ARGS_ASSERT_OPSLAB_FREE;
81611534 383 PERL_UNUSED_CONTEXT;
eb212a1c 384 DEBUG_S_warn((aTHX_ "freeing slab %p", (void*)slab));
8be227ab
FC
385 assert(slab->opslab_refcnt == 1);
386 for (; slab; slab = slab2) {
387 slab2 = slab->opslab_next;
7aef8e5b 388#ifdef DEBUGGING
8be227ab 389 slab->opslab_refcnt = ~(size_t)0;
7aef8e5b
FC
390#endif
391#ifdef PERL_DEBUG_READONLY_OPS
3107b51f 392 DEBUG_m(PerlIO_printf(Perl_debug_log, "Deallocate slab at %p\n",
eb212a1c 393 (void*)slab));
3107b51f
FC
394 if (munmap(slab, slab->opslab_size * sizeof(I32 *))) {
395 perror("munmap failed");
396 abort();
397 }
7aef8e5b 398#else
8be227ab 399 PerlMemShared_free(slab);
7aef8e5b 400#endif
8be227ab
FC
401 }
402}
403
404void
405Perl_opslab_force_free(pTHX_ OPSLAB *slab)
406{
407 OPSLAB *slab2;
408 OPSLOT *slot;
7aef8e5b 409#ifdef DEBUGGING
8be227ab 410 size_t savestack_count = 0;
7aef8e5b 411#endif
8be227ab
FC
412 PERL_ARGS_ASSERT_OPSLAB_FORCE_FREE;
413 slab2 = slab;
414 do {
415 for (slot = slab2->opslab_first;
416 slot->opslot_next;
417 slot = slot->opslot_next) {
418 if (slot->opslot_op.op_type != OP_FREED
419 && !(slot->opslot_op.op_savefree
7aef8e5b 420#ifdef DEBUGGING
8be227ab 421 && ++savestack_count
7aef8e5b 422#endif
8be227ab
FC
423 )
424 ) {
425 assert(slot->opslot_op.op_slabbed);
8be227ab 426 op_free(&slot->opslot_op);
3bf28c7e 427 if (slab->opslab_refcnt == 1) goto free;
8be227ab
FC
428 }
429 }
430 } while ((slab2 = slab2->opslab_next));
431 /* > 1 because the CV still holds a reference count. */
432 if (slab->opslab_refcnt > 1) { /* still referenced by the savestack */
7aef8e5b 433#ifdef DEBUGGING
8be227ab 434 assert(savestack_count == slab->opslab_refcnt-1);
7aef8e5b 435#endif
ee5ee853
FC
436 /* Remove the CV’s reference count. */
437 slab->opslab_refcnt--;
8be227ab
FC
438 return;
439 }
440 free:
441 opslab_free(slab);
442}
443
3107b51f
FC
444#ifdef PERL_DEBUG_READONLY_OPS
445OP *
446Perl_op_refcnt_inc(pTHX_ OP *o)
447{
448 if(o) {
372eab01
NC
449 OPSLAB *const slab = o->op_slabbed ? OpSLAB(o) : NULL;
450 if (slab && slab->opslab_readonly) {
83519873 451 Slab_to_rw(slab);
372eab01
NC
452 ++o->op_targ;
453 Slab_to_ro(slab);
454 } else {
455 ++o->op_targ;
456 }
3107b51f
FC
457 }
458 return o;
459
460}
461
462PADOFFSET
463Perl_op_refcnt_dec(pTHX_ OP *o)
464{
372eab01
NC
465 PADOFFSET result;
466 OPSLAB *const slab = o->op_slabbed ? OpSLAB(o) : NULL;
467
3107b51f 468 PERL_ARGS_ASSERT_OP_REFCNT_DEC;
372eab01
NC
469
470 if (slab && slab->opslab_readonly) {
83519873 471 Slab_to_rw(slab);
372eab01
NC
472 result = --o->op_targ;
473 Slab_to_ro(slab);
474 } else {
475 result = --o->op_targ;
476 }
477 return result;
3107b51f
FC
478}
479#endif
e50aee73 480/*
ce6f1cbc 481 * In the following definition, the ", (OP*)0" is just to make the compiler
a5f75d66 482 * think the expression is of the right type: croak actually does a Siglongjmp.
e50aee73 483 */
11343788 484#define CHECKOP(type,o) \
ce6f1cbc 485 ((PL_op_mask && PL_op_mask[type]) \
5dc0d613 486 ? ( op_free((OP*)o), \
cb77fdf0 487 Perl_croak(aTHX_ "'%s' trapped by operation mask", PL_op_desc[type]), \
ce6f1cbc 488 (OP*)0 ) \
16c91539 489 : PL_check[type](aTHX_ (OP*)o))
e50aee73 490
e6438c1a 491#define RETURN_UNLIMITED_NUMBER (PERL_INT_MAX / 2)
c53d7c7d 492
cba5a3b0
DG
493#define CHANGE_TYPE(o,type) \
494 STMT_START { \
495 o->op_type = (OPCODE)type; \
496 o->op_ppaddr = PL_ppaddr[type]; \
497 } STMT_END
498
76e3520e 499STATIC OP *
cea2e8a9 500S_no_fh_allowed(pTHX_ OP *o)
79072805 501{
7918f24d
NC
502 PERL_ARGS_ASSERT_NO_FH_ALLOWED;
503
cea2e8a9 504 yyerror(Perl_form(aTHX_ "Missing comma after first argument to %s function",
53e06cf0 505 OP_DESC(o)));
11343788 506 return o;
79072805
LW
507}
508
76e3520e 509STATIC OP *
ce16c625
BF
510S_too_few_arguments_pv(pTHX_ OP *o, const char* name, U32 flags)
511{
512 PERL_ARGS_ASSERT_TOO_FEW_ARGUMENTS_PV;
513 yyerror_pv(Perl_form(aTHX_ "Not enough arguments for %s", name), flags);
514 return o;
515}
516
517STATIC OP *
518S_too_many_arguments_pv(pTHX_ OP *o, const char *name, U32 flags)
519{
520 PERL_ARGS_ASSERT_TOO_MANY_ARGUMENTS_PV;
7918f24d 521
ce16c625 522 yyerror_pv(Perl_form(aTHX_ "Too many arguments for %s", name), flags);
11343788 523 return o;
79072805
LW
524}
525
76e3520e 526STATIC void
ce16c625 527S_bad_type_pv(pTHX_ I32 n, const char *t, const char *name, U32 flags, const OP *kid)
8990e307 528{
ce16c625
BF
529 PERL_ARGS_ASSERT_BAD_TYPE_PV;
530
531 yyerror_pv(Perl_form(aTHX_ "Type of arg %d to %s must be %s (not %s)",
532 (int)n, name, t, OP_DESC(kid)), flags);
533}
7918f24d 534
ce16c625 535STATIC void
7b3b0904 536S_bad_type_gv(pTHX_ I32 n, const char *t, GV *gv, U32 flags, const OP *kid)
ce16c625 537{
a65cc145 538 SV * const namesv = cv_name((CV *)gv, NULL);
7b3b0904 539 PERL_ARGS_ASSERT_BAD_TYPE_GV;
ce16c625
BF
540
541 yyerror_pv(Perl_form(aTHX_ "Type of arg %d to %"SVf" must be %s (not %s)",
542 (int)n, SVfARG(namesv), t, OP_DESC(kid)), SvUTF8(namesv) | flags);
8990e307
LW
543}
544
7a52d87a 545STATIC void
eb796c7f 546S_no_bareword_allowed(pTHX_ OP *o)
7a52d87a 547{
7918f24d
NC
548 PERL_ARGS_ASSERT_NO_BAREWORD_ALLOWED;
549
5a844595 550 qerror(Perl_mess(aTHX_
35c1215d 551 "Bareword \"%"SVf"\" not allowed while \"strict subs\" in use",
be2597df 552 SVfARG(cSVOPo_sv)));
eb796c7f 553 o->op_private &= ~OPpCONST_STRICT; /* prevent warning twice about the same OP */
7a52d87a
GS
554}
555
79072805
LW
556/* "register" allocation */
557
558PADOFFSET
d6447115 559Perl_allocmy(pTHX_ const char *const name, const STRLEN len, const U32 flags)
93a17b20 560{
a0d0e21e 561 PADOFFSET off;
12bd6ede 562 const bool is_our = (PL_parser->in_my == KEY_our);
a0d0e21e 563
7918f24d
NC
564 PERL_ARGS_ASSERT_ALLOCMY;
565
48d0d1be 566 if (flags & ~SVf_UTF8)
d6447115
NC
567 Perl_croak(aTHX_ "panic: allocmy illegal flag bits 0x%" UVxf,
568 (UV)flags);
569
570 /* Until we're using the length for real, cross check that we're being
571 told the truth. */
572 assert(strlen(name) == len);
573
59f00321 574 /* complain about "my $<special_var>" etc etc */
d6447115 575 if (len &&
3edf23ff 576 !(is_our ||
155aba94 577 isALPHA(name[1]) ||
b14845b4 578 ((flags & SVf_UTF8) && isIDFIRST_utf8((U8 *)name+1)) ||
d6447115 579 (name[1] == '_' && (*name == '$' || len > 2))))
834a4ddd 580 {
6b58708b 581 /* name[2] is true if strlen(name) > 2 */
b14845b4
FC
582 if (!(flags & SVf_UTF8 && UTF8_IS_START(name[1]))
583 && (!isPRINT(name[1]) || strchr("\t\n\r\f", name[1]))) {
d6447115
NC
584 yyerror(Perl_form(aTHX_ "Can't use global %c^%c%.*s in \"%s\"",
585 name[0], toCTRL(name[1]), (int)(len - 2), name + 2,
aab6a793 586 PL_parser->in_my == KEY_state ? "state" : "my"));
d1544d85 587 } else {
ce16c625
BF
588 yyerror_pv(Perl_form(aTHX_ "Can't use global %.*s in \"%s\"", (int) len, name,
589 PL_parser->in_my == KEY_state ? "state" : "my"), flags & SVf_UTF8);
46fc3d4c 590 }
a0d0e21e 591 }
4055dbce
RS
592 else if (len == 2 && name[1] == '_' && !is_our)
593 /* diag_listed_as: Use of my $_ is experimental */
594 Perl_ck_warner_d(aTHX_ packWARN(WARN_EXPERIMENTAL__LEXICAL_TOPIC),
595 "Use of %s $_ is experimental",
596 PL_parser->in_my == KEY_state
597 ? "state"
598 : "my");
748a9306 599
dd2155a4 600 /* allocate a spare slot and store the name in that slot */
93a17b20 601
cc76b5cc 602 off = pad_add_name_pvn(name, len,
48d0d1be
BF
603 (is_our ? padadd_OUR :
604 PL_parser->in_my == KEY_state ? padadd_STATE : 0)
605 | ( flags & SVf_UTF8 ? SVf_UTF8 : 0 ),
12bd6ede 606 PL_parser->in_my_stash,
3edf23ff 607 (is_our
133706a6
RGS
608 /* $_ is always in main::, even with our */
609 ? (PL_curstash && !strEQ(name,"$_") ? PL_curstash : PL_defstash)
5c284bb0 610 : NULL
cca43f78 611 )
dd2155a4 612 );
a74073ad
DM
613 /* anon sub prototypes contains state vars should always be cloned,
614 * otherwise the state var would be shared between anon subs */
615
616 if (PL_parser->in_my == KEY_state && CvANON(PL_compcv))
617 CvCLONE_on(PL_compcv);
618
dd2155a4 619 return off;
79072805
LW
620}
621
c0b8aebd 622/*
dcccc8ff
KW
623=head1 Optree Manipulation Functions
624
c0b8aebd
FC
625=for apidoc alloccopstash
626
627Available only under threaded builds, this function allocates an entry in
628C<PL_stashpad> for the stash passed to it.
629
630=cut
631*/
632
d4d03940
FC
633#ifdef USE_ITHREADS
634PADOFFSET
1dc74fdb 635Perl_alloccopstash(pTHX_ HV *hv)
d4d03940
FC
636{
637 PADOFFSET off = 0, o = 1;
638 bool found_slot = FALSE;
639
1dc74fdb
FC
640 PERL_ARGS_ASSERT_ALLOCCOPSTASH;
641
642 if (PL_stashpad[PL_stashpadix] == hv) return PL_stashpadix;
d4d03940 643
1dc74fdb
FC
644 for (; o < PL_stashpadmax; ++o) {
645 if (PL_stashpad[o] == hv) return PL_stashpadix = o;
646 if (!PL_stashpad[o] || SvTYPE(PL_stashpad[o]) != SVt_PVHV)
d4d03940
FC
647 found_slot = TRUE, off = o;
648 }
649 if (!found_slot) {
1dc74fdb
FC
650 Renew(PL_stashpad, PL_stashpadmax + 10, HV *);
651 Zero(PL_stashpad + PL_stashpadmax, 10, HV *);
652 off = PL_stashpadmax;
653 PL_stashpadmax += 10;
d4d03940
FC
654 }
655
1dc74fdb 656 PL_stashpad[PL_stashpadix = off] = hv;
d4d03940
FC
657 return off;
658}
659#endif
660
d2c837a0
DM
661/* free the body of an op without examining its contents.
662 * Always use this rather than FreeOp directly */
663
4136a0f7 664static void
d2c837a0
DM
665S_op_destroy(pTHX_ OP *o)
666{
d2c837a0
DM
667 FreeOp(o);
668}
669
79072805
LW
670/* Destructor */
671
6e53b6ca
DD
672/*
673=for apidoc Am|void|op_free|OP *o
674
cc41839b
FC
675Free an op. Only use this when an op is no longer linked to from any
676optree.
6e53b6ca
DD
677
678=cut
679*/
680
79072805 681void
864dbfa3 682Perl_op_free(pTHX_ OP *o)
79072805 683{
20b7effb 684#ifdef USE_ITHREADS
27da23d5 685 dVAR;
20b7effb 686#endif
acb36ea4 687 OPCODE type;
79072805 688
8be227ab
FC
689 /* Though ops may be freed twice, freeing the op after its slab is a
690 big no-no. */
691 assert(!o || !o->op_slabbed || OpSLAB(o)->opslab_refcnt != ~(size_t)0);
8be227ab
FC
692 /* During the forced freeing of ops after compilation failure, kidops
693 may be freed before their parents. */
694 if (!o || o->op_type == OP_FREED)
79072805
LW
695 return;
696
67566ccd 697 type = o->op_type;
d0c8136d
DM
698
699 /* an op should only ever acquire op_private flags that we know about.
700 * If this fails, you may need to fix something in regen/op_private */
701 assert(!(o->op_private & ~PL_op_private_valid[type]));
702
7934575e 703 if (o->op_private & OPpREFCOUNTED) {
67566ccd 704 switch (type) {
7934575e
GS
705 case OP_LEAVESUB:
706 case OP_LEAVESUBLV:
707 case OP_LEAVEEVAL:
708 case OP_LEAVE:
709 case OP_SCOPE:
710 case OP_LEAVEWRITE:
67566ccd
AL
711 {
712 PADOFFSET refcnt;
7934575e 713 OP_REFCNT_LOCK;
4026c95a 714 refcnt = OpREFCNT_dec(o);
7934575e 715 OP_REFCNT_UNLOCK;
bfd0ff22
NC
716 if (refcnt) {
717 /* Need to find and remove any pattern match ops from the list
718 we maintain for reset(). */
719 find_and_forget_pmops(o);
4026c95a 720 return;
67566ccd 721 }
bfd0ff22 722 }
7934575e
GS
723 break;
724 default:
725 break;
726 }
727 }
728
f37b8c3f
VP
729 /* Call the op_free hook if it has been set. Do it now so that it's called
730 * at the right time for refcounted ops, but still before all of the kids
731 * are freed. */
732 CALL_OPFREEHOOK(o);
733
11343788 734 if (o->op_flags & OPf_KIDS) {
eb578fdb 735 OP *kid, *nextkid;
11343788 736 for (kid = cUNOPo->op_first; kid; kid = nextkid) {
1ed44841 737 nextkid = OP_SIBLING(kid); /* Get before next freeing kid */
79072805 738 op_free(kid);
85e6fe83 739 }
79072805 740 }
513f78f7
FC
741 if (type == OP_NULL)
742 type = (OPCODE)o->op_targ;
acb36ea4 743
9e4d7a13
NC
744 if (o->op_slabbed)
745 Slab_to_rw(OpSLAB(o));
fc97af9c 746
acb36ea4
GS
747 /* COP* is not cleared by op_clear() so that we may track line
748 * numbers etc even after null() */
513f78f7 749 if (type == OP_NEXTSTATE || type == OP_DBSTATE) {
acb36ea4 750 cop_free((COP*)o);
3235b7a3 751 }
acb36ea4
GS
752
753 op_clear(o);
238a4c30 754 FreeOp(o);
4d494880
DM
755#ifdef DEBUG_LEAKING_SCALARS
756 if (PL_op == o)
5f66b61c 757 PL_op = NULL;
4d494880 758#endif
acb36ea4 759}
79072805 760
93c66552
DM
761void
762Perl_op_clear(pTHX_ OP *o)
acb36ea4 763{
13137afc 764
27da23d5 765 dVAR;
7918f24d
NC
766
767 PERL_ARGS_ASSERT_OP_CLEAR;
768
11343788 769 switch (o->op_type) {
acb36ea4 770 case OP_NULL: /* Was holding old type, if any. */
c67159e1 771 /* FALLTHROUGH */
4d193d44 772 case OP_ENTERTRY:
acb36ea4 773 case OP_ENTEREVAL: /* Was holding hints. */
acb36ea4 774 o->op_targ = 0;
a0d0e21e 775 break;
a6006777 776 default:
ac4c12e7 777 if (!(o->op_flags & OPf_REF)
ef69c8fc 778 || (PL_check[o->op_type] != Perl_ck_ftst))
a6006777 779 break;
924ba076 780 /* FALLTHROUGH */
463ee0b2 781 case OP_GVSV:
79072805 782 case OP_GV:
a6006777 783 case OP_AELEMFAST:
93bad3fd 784 {
f7461760
Z
785 GV *gv = (o->op_type == OP_GV || o->op_type == OP_GVSV)
786#ifdef USE_ITHREADS
787 && PL_curpad
788#endif
789 ? cGVOPo_gv : NULL;
b327b36f
NC
790 /* It's possible during global destruction that the GV is freed
791 before the optree. Whilst the SvREFCNT_inc is happy to bump from
792 0 to 1 on a freed SV, the corresponding SvREFCNT_dec from 1 to 0
793 will trigger an assertion failure, because the entry to sv_clear
794 checks that the scalar is not already freed. A check of for
795 !SvIS_FREED(gv) turns out to be invalid, because during global
796 destruction the reference count can be forced down to zero
797 (with SVf_BREAK set). In which case raising to 1 and then
798 dropping to 0 triggers cleanup before it should happen. I
799 *think* that this might actually be a general, systematic,
800 weakness of the whole idea of SVf_BREAK, in that code *is*
801 allowed to raise and lower references during global destruction,
802 so any *valid* code that happens to do this during global
803 destruction might well trigger premature cleanup. */
804 bool still_valid = gv && SvREFCNT(gv);
805
806 if (still_valid)
807 SvREFCNT_inc_simple_void(gv);
350de78d 808#ifdef USE_ITHREADS
6a077020 809 if (cPADOPo->op_padix > 0) {
6a077020
DM
810 pad_swipe(cPADOPo->op_padix, TRUE);
811 cPADOPo->op_padix = 0;
812 }
350de78d 813#else
6a077020 814 SvREFCNT_dec(cSVOPo->op_sv);
a0714e2c 815 cSVOPo->op_sv = NULL;
350de78d 816#endif
b327b36f 817 if (still_valid) {
f7461760 818 int try_downgrade = SvREFCNT(gv) == 2;
fc2b2dca 819 SvREFCNT_dec_NN(gv);
f7461760
Z
820 if (try_downgrade)
821 gv_try_downgrade(gv);
822 }
6a077020 823 }
79072805 824 break;
a1ae71d2 825 case OP_METHOD_NAMED:
79072805 826 case OP_CONST:
996c9baa 827 case OP_HINTSEVAL:
11343788 828 SvREFCNT_dec(cSVOPo->op_sv);
a0714e2c 829 cSVOPo->op_sv = NULL;
3b1c21fa
AB
830#ifdef USE_ITHREADS
831 /** Bug #15654
832 Even if op_clear does a pad_free for the target of the op,
6a077020 833 pad_free doesn't actually remove the sv that exists in the pad;
3b1c21fa
AB
834 instead it lives on. This results in that it could be reused as
835 a target later on when the pad was reallocated.
836 **/
837 if(o->op_targ) {
838 pad_swipe(o->op_targ,1);
839 o->op_targ = 0;
840 }
841#endif
79072805 842 break;
c9df4fda 843 case OP_DUMP:
748a9306
LW
844 case OP_GOTO:
845 case OP_NEXT:
846 case OP_LAST:
847 case OP_REDO:
11343788 848 if (o->op_flags & (OPf_SPECIAL|OPf_STACKED|OPf_KIDS))
748a9306 849 break;
924ba076 850 /* FALLTHROUGH */
a0d0e21e 851 case OP_TRANS:
bb16bae8 852 case OP_TRANSR:
acb36ea4 853 if (o->op_private & (OPpTRANS_FROM_UTF|OPpTRANS_TO_UTF)) {
99a1d0d1 854 assert(o->op_type == OP_TRANS || o->op_type == OP_TRANSR);
043e41b8
DM
855#ifdef USE_ITHREADS
856 if (cPADOPo->op_padix > 0) {
857 pad_swipe(cPADOPo->op_padix, TRUE);
858 cPADOPo->op_padix = 0;
859 }
860#else
a0ed51b3 861 SvREFCNT_dec(cSVOPo->op_sv);
a0714e2c 862 cSVOPo->op_sv = NULL;
043e41b8 863#endif
acb36ea4
GS
864 }
865 else {
ea71c68d 866 PerlMemShared_free(cPVOPo->op_pv);
bd61b366 867 cPVOPo->op_pv = NULL;
acb36ea4 868 }
a0d0e21e
LW
869 break;
870 case OP_SUBST:
20e98b0f 871 op_free(cPMOPo->op_pmreplrootu.op_pmreplroot);
971a9dd3 872 goto clear_pmop;
748a9306 873 case OP_PUSHRE:
971a9dd3 874#ifdef USE_ITHREADS
20e98b0f 875 if (cPMOPo->op_pmreplrootu.op_pmtargetoff) {
20e98b0f 876 pad_swipe(cPMOPo->op_pmreplrootu.op_pmtargetoff, TRUE);
971a9dd3
GS
877 }
878#else
ad64d0ec 879 SvREFCNT_dec(MUTABLE_SV(cPMOPo->op_pmreplrootu.op_pmtargetgv));
971a9dd3 880#endif
924ba076 881 /* FALLTHROUGH */
a0d0e21e 882 case OP_MATCH:
8782bef2 883 case OP_QR:
971a9dd3 884clear_pmop:
867940b8
DM
885 if (!(cPMOPo->op_pmflags & PMf_CODELIST_PRIVATE))
886 op_free(cPMOPo->op_code_list);
68e2671b 887 cPMOPo->op_code_list = NULL;
23083432 888 forget_pmop(cPMOPo);
20e98b0f 889 cPMOPo->op_pmreplrootu.op_pmreplroot = NULL;
9cddf794
NC
890 /* we use the same protection as the "SAFE" version of the PM_ macros
891 * here since sv_clean_all might release some PMOPs
5f8cb046
DM
892 * after PL_regex_padav has been cleared
893 * and the clearing of PL_regex_padav needs to
894 * happen before sv_clean_all
895 */
13137afc
AB
896#ifdef USE_ITHREADS
897 if(PL_regex_pad) { /* We could be in destruction */
402d2eb1 898 const IV offset = (cPMOPo)->op_pmoffset;
9cddf794 899 ReREFCNT_dec(PM_GETRE(cPMOPo));
402d2eb1
NC
900 PL_regex_pad[offset] = &PL_sv_undef;
901 sv_catpvn_nomg(PL_regex_pad[0], (const char *)&offset,
902 sizeof(offset));
13137afc 903 }
9cddf794
NC
904#else
905 ReREFCNT_dec(PM_GETRE(cPMOPo));
906 PM_SETRE(cPMOPo, NULL);
1eb1540c 907#endif
13137afc 908
a0d0e21e 909 break;
79072805
LW
910 }
911
743e66e6 912 if (o->op_targ > 0) {
11343788 913 pad_free(o->op_targ);
743e66e6
GS
914 o->op_targ = 0;
915 }
79072805
LW
916}
917
76e3520e 918STATIC void
3eb57f73
HS
919S_cop_free(pTHX_ COP* cop)
920{
7918f24d
NC
921 PERL_ARGS_ASSERT_COP_FREE;
922
05ec9bb3 923 CopFILE_free(cop);
0453d815 924 if (! specialWARN(cop->cop_warnings))
72dc9ed5 925 PerlMemShared_free(cop->cop_warnings);
20439bc7 926 cophh_free(CopHINTHASH_get(cop));
515abc43
FC
927 if (PL_curcop == cop)
928 PL_curcop = NULL;
3eb57f73
HS
929}
930
c2b1997a 931STATIC void
c4bd3ae5 932S_forget_pmop(pTHX_ PMOP *const o
c4bd3ae5 933 )
c2b1997a
NC
934{
935 HV * const pmstash = PmopSTASH(o);
7918f24d
NC
936
937 PERL_ARGS_ASSERT_FORGET_PMOP;
938
e39a6381 939 if (pmstash && !SvIS_FREED(pmstash) && SvMAGICAL(pmstash)) {
ad64d0ec 940 MAGIC * const mg = mg_find((const SV *)pmstash, PERL_MAGIC_symtab);
c2b1997a
NC
941 if (mg) {
942 PMOP **const array = (PMOP**) mg->mg_ptr;
943 U32 count = mg->mg_len / sizeof(PMOP**);
944 U32 i = count;
945
946 while (i--) {
947 if (array[i] == o) {
948 /* Found it. Move the entry at the end to overwrite it. */
949 array[i] = array[--count];
950 mg->mg_len = count * sizeof(PMOP**);
951 /* Could realloc smaller at this point always, but probably
952 not worth it. Probably worth free()ing if we're the
953 last. */
954 if(!count) {
955 Safefree(mg->mg_ptr);
956 mg->mg_ptr = NULL;
957 }
958 break;
959 }
960 }
961 }
962 }
1cdf7faf
NC
963 if (PL_curpm == o)
964 PL_curpm = NULL;
c2b1997a
NC
965}
966
bfd0ff22
NC
967STATIC void
968S_find_and_forget_pmops(pTHX_ OP *o)
969{
7918f24d
NC
970 PERL_ARGS_ASSERT_FIND_AND_FORGET_PMOPS;
971
bfd0ff22
NC
972 if (o->op_flags & OPf_KIDS) {
973 OP *kid = cUNOPo->op_first;
974 while (kid) {
975 switch (kid->op_type) {
976 case OP_SUBST:
977 case OP_PUSHRE:
978 case OP_MATCH:
979 case OP_QR:
23083432 980 forget_pmop((PMOP*)kid);
bfd0ff22
NC
981 }
982 find_and_forget_pmops(kid);
1ed44841 983 kid = OP_SIBLING(kid);
bfd0ff22
NC
984 }
985 }
986}
987
6e53b6ca
DD
988/*
989=for apidoc Am|void|op_null|OP *o
990
991Neutralizes an op when it is no longer needed, but is still linked to from
992other ops.
993
994=cut
995*/
996
93c66552
DM
997void
998Perl_op_null(pTHX_ OP *o)
8990e307 999{
27da23d5 1000 dVAR;
7918f24d
NC
1001
1002 PERL_ARGS_ASSERT_OP_NULL;
1003
acb36ea4
GS
1004 if (o->op_type == OP_NULL)
1005 return;
b5bbe64a 1006 op_clear(o);
11343788
MB
1007 o->op_targ = o->op_type;
1008 o->op_type = OP_NULL;
22c35a8c 1009 o->op_ppaddr = PL_ppaddr[OP_NULL];
8990e307
LW
1010}
1011
4026c95a
SH
1012void
1013Perl_op_refcnt_lock(pTHX)
1014{
20b7effb 1015#ifdef USE_ITHREADS
27da23d5 1016 dVAR;
20b7effb 1017#endif
96a5add6 1018 PERL_UNUSED_CONTEXT;
4026c95a
SH
1019 OP_REFCNT_LOCK;
1020}
1021
1022void
1023Perl_op_refcnt_unlock(pTHX)
1024{
20b7effb 1025#ifdef USE_ITHREADS
27da23d5 1026 dVAR;
20b7effb 1027#endif
96a5add6 1028 PERL_UNUSED_CONTEXT;
4026c95a
SH
1029 OP_REFCNT_UNLOCK;
1030}
1031
3253bf85
DM
1032
1033/*
1034=for apidoc op_sibling_splice
1035
1036A general function for editing the structure of an existing chain of
1037op_sibling nodes. By analogy with the perl-level splice() function, allows
1038you to delete zero or more sequential nodes, replacing them with zero or
1039more different nodes. Performs the necessary op_first/op_last
29e61fd9 1040housekeeping on the parent node and op_sibling manipulation on the
8ae26bff
DM
1041children. The last deleted node will be marked as as the last node by
1042updating the op_sibling or op_lastsib field as appropriate.
3253bf85
DM
1043
1044Note that op_next is not manipulated, and nodes are not freed; that is the
8ae26bff
DM
1045responsibility of the caller. It also won't create a new list op for an
1046empty list etc; use higher-level functions like op_append_elem() for that.
3253bf85
DM
1047
1048parent is the parent node of the sibling chain.
1049
1050start is the node preceding the first node to be spliced. Node(s)
1051following it will be deleted, and ops will be inserted after it. If it is
1052NULL, the first node onwards is deleted, and nodes are inserted at the
1053beginning.
1054
1055del_count is the number of nodes to delete. If zero, no nodes are deleted.
1056If -1 or greater than or equal to the number of remaining kids, all
1057remaining kids are deleted.
1058
1059insert is the first of a chain of nodes to be inserted in place of the nodes.
1060If NULL, no nodes are inserted.
1061
8ae26bff 1062The head of the chain of deleted ops is returned, or NULL if no ops were
3253bf85
DM
1063deleted.
1064
1065For example:
1066
1067 action before after returns
1068 ------ ----- ----- -------
1069
1070 P P
8ae26bff
DM
1071 splice(P, A, 2, X-Y-Z) | | B-C
1072 A-B-C-D A-X-Y-Z-D
3253bf85
DM
1073
1074 P P
1075 splice(P, NULL, 1, X-Y) | | A
1076 A-B-C-D X-Y-B-C-D
1077
1078 P P
8ae26bff
DM
1079 splice(P, NULL, 3, NULL) | | A-B-C
1080 A-B-C-D D
3253bf85
DM
1081
1082 P P
1083 splice(P, B, 0, X-Y) | | NULL
1084 A-B-C-D A-B-X-Y-C-D
1085
1086=cut
1087*/
1088
1089OP *
8ae26bff 1090Perl_op_sibling_splice(OP *parent, OP *start, int del_count, OP* insert)
3253bf85 1091{
3253bf85
DM
1092 OP *first = start ? OP_SIBLING(start) : cLISTOPx(parent)->op_first;
1093 OP *rest;
1094 OP *last_del = NULL;
1095 OP *last_ins = NULL;
1096
1097 PERL_ARGS_ASSERT_OP_SIBLING_SPLICE;
1098
1099 assert(del_count >= -1);
1100
1101 if (del_count && first) {
1102 last_del = first;
1103 while (--del_count && OP_HAS_SIBLING(last_del))
1104 last_del = OP_SIBLING(last_del);
1105 rest = OP_SIBLING(last_del);
1106 OP_SIBLING_set(last_del, NULL);
29e61fd9 1107 last_del->op_lastsib = 1;
3253bf85
DM
1108 }
1109 else
1110 rest = first;
1111
1112 if (insert) {
1113 last_ins = insert;
1114 while (OP_HAS_SIBLING(last_ins))
1115 last_ins = OP_SIBLING(last_ins);
1116 OP_SIBLING_set(last_ins, rest);
29e61fd9 1117 last_ins->op_lastsib = rest ? 0 : 1;
3253bf85
DM
1118 }
1119 else
1120 insert = rest;
1121
29e61fd9 1122 if (start) {
3253bf85 1123 OP_SIBLING_set(start, insert);
29e61fd9
DM
1124 start->op_lastsib = insert ? 0 : 1;
1125 }
3253bf85
DM
1126 else
1127 cLISTOPx(parent)->op_first = insert;
1128
1129 if (!rest) {
29e61fd9 1130 /* update op_last etc */
3253bf85 1131 U32 type = parent->op_type;
29e61fd9 1132 OP *lastop;
3253bf85
DM
1133
1134 if (type == OP_NULL)
1135 type = parent->op_targ;
1136 type = PL_opargs[type] & OA_CLASS_MASK;
1137
29e61fd9 1138 lastop = last_ins ? last_ins : start ? start : NULL;
3253bf85
DM
1139 if ( type == OA_BINOP
1140 || type == OA_LISTOP
1141 || type == OA_PMOP
1142 || type == OA_LOOP
1143 )
29e61fd9
DM
1144 cLISTOPx(parent)->op_last = lastop;
1145
1146 if (lastop) {
1147 lastop->op_lastsib = 1;
1148#ifdef PERL_OP_PARENT
1149 lastop->op_sibling = parent;
1150#endif
1151 }
3253bf85
DM
1152 }
1153 return last_del ? first : NULL;
1154}
1155
29e61fd9
DM
1156/*
1157=for apidoc op_parent
1158
1159returns the parent OP of o, if it has a parent. Returns NULL otherwise.
1160(Currently perl must be built with C<-DPERL_OP_PARENT> for this feature to
1161work.
1162
1163=cut
1164*/
1165
1166OP *
8ae26bff 1167Perl_op_parent(OP *o)
29e61fd9
DM
1168{
1169 PERL_ARGS_ASSERT_OP_PARENT;
1170#ifdef PERL_OP_PARENT
1171 while (OP_HAS_SIBLING(o))
1172 o = OP_SIBLING(o);
1173 return o->op_sibling;
1174#else
1175 PERL_UNUSED_ARG(o);
1176 return NULL;
1177#endif
1178}
1179
3253bf85
DM
1180
1181/* replace the sibling following start with a new UNOP, which becomes
1182 * the parent of the original sibling; e.g.
1183 *
1184 * op_sibling_newUNOP(P, A, unop-args...)
1185 *
1186 * P P
1187 * | becomes |
1188 * A-B-C A-U-C
1189 * |
1190 * B
1191 *
1192 * where U is the new UNOP.
1193 *
1194 * parent and start args are the same as for op_sibling_splice();
1195 * type and flags args are as newUNOP().
1196 *
1197 * Returns the new UNOP.
1198 */
1199
1200OP *
1201S_op_sibling_newUNOP(pTHX_ OP *parent, OP *start, I32 type, I32 flags)
1202{
1203 OP *kid, *newop;
1204
1205 kid = op_sibling_splice(parent, start, 1, NULL);
1206 newop = newUNOP(type, flags, kid);
1207 op_sibling_splice(parent, start, 0, newop);
1208 return newop;
1209}
1210
1211
1212/* lowest-level newLOGOP-style function - just allocates and populates
1213 * the struct. Higher-level stuff should be done by S_new_logop() /
1214 * newLOGOP(). This function exists mainly to avoid op_first assignment
1215 * being spread throughout this file.
1216 */
1217
1218LOGOP *
1219S_alloc_LOGOP(pTHX_ I32 type, OP *first, OP* other)
1220{
1221 LOGOP *logop;
29e61fd9 1222 OP *kid = first;
3253bf85 1223 NewOp(1101, logop, 1, LOGOP);
8ae26bff 1224 logop->op_type = (OPCODE)type;
3253bf85
DM
1225 logop->op_first = first;
1226 logop->op_other = other;
1227 logop->op_flags = OPf_KIDS;
29e61fd9
DM
1228 while (kid && OP_HAS_SIBLING(kid))
1229 kid = OP_SIBLING(kid);
1230 if (kid) {
1231 kid->op_lastsib = 1;
1232#ifdef PERL_OP_PARENT
1233 kid->op_sibling = (OP*)logop;
1234#endif
1235 }
3253bf85
DM
1236 return logop;
1237}
1238
1239
79072805
LW
1240/* Contextualizers */
1241
d9088386
Z
1242/*
1243=for apidoc Am|OP *|op_contextualize|OP *o|I32 context
1244
1245Applies a syntactic context to an op tree representing an expression.
1246I<o> is the op tree, and I<context> must be C<G_SCALAR>, C<G_ARRAY>,
1247or C<G_VOID> to specify the context to apply. The modified op tree
1248is returned.
1249
1250=cut
1251*/
1252
1253OP *
1254Perl_op_contextualize(pTHX_ OP *o, I32 context)
1255{
1256 PERL_ARGS_ASSERT_OP_CONTEXTUALIZE;
1257 switch (context) {
1258 case G_SCALAR: return scalar(o);
1259 case G_ARRAY: return list(o);
1260 case G_VOID: return scalarvoid(o);
1261 default:
5637ef5b
NC
1262 Perl_croak(aTHX_ "panic: op_contextualize bad context %ld",
1263 (long) context);
d9088386
Z
1264 }
1265}
1266
5983a79d 1267/*
79072805 1268
5983a79d 1269=for apidoc Am|OP*|op_linklist|OP *o
72d33970 1270This function is the implementation of the L</LINKLIST> macro. It should
5983a79d
BM
1271not be called directly.
1272
1273=cut
1274*/
1275
1276OP *
1277Perl_op_linklist(pTHX_ OP *o)
79072805 1278{
3edf23ff 1279 OP *first;
79072805 1280
5983a79d 1281 PERL_ARGS_ASSERT_OP_LINKLIST;
7918f24d 1282
11343788
MB
1283 if (o->op_next)
1284 return o->op_next;
79072805
LW
1285
1286 /* establish postfix order */
3edf23ff
AL
1287 first = cUNOPo->op_first;
1288 if (first) {
eb578fdb 1289 OP *kid;
3edf23ff
AL
1290 o->op_next = LINKLIST(first);
1291 kid = first;
1292 for (;;) {
29e61fd9
DM
1293 OP *sibl = OP_SIBLING(kid);
1294 if (sibl) {
1295 kid->op_next = LINKLIST(sibl);
1296 kid = sibl;
3edf23ff 1297 } else {
11343788 1298 kid->op_next = o;
3edf23ff
AL
1299 break;
1300 }
79072805
LW
1301 }
1302 }
1303 else
11343788 1304 o->op_next = o;
79072805 1305
11343788 1306 return o->op_next;
79072805
LW
1307}
1308
1f676739 1309static OP *
2dd5337b 1310S_scalarkids(pTHX_ OP *o)
79072805 1311{
11343788 1312 if (o && o->op_flags & OPf_KIDS) {
bfed75c6 1313 OP *kid;
1ed44841 1314 for (kid = cLISTOPo->op_first; kid; kid = OP_SIBLING(kid))
79072805
LW
1315 scalar(kid);
1316 }
11343788 1317 return o;
79072805
LW
1318}
1319
76e3520e 1320STATIC OP *
cea2e8a9 1321S_scalarboolean(pTHX_ OP *o)
8990e307 1322{
7918f24d
NC
1323 PERL_ARGS_ASSERT_SCALARBOOLEAN;
1324
6b7c6d95
FC
1325 if (o->op_type == OP_SASSIGN && cBINOPo->op_first->op_type == OP_CONST
1326 && !(cBINOPo->op_first->op_flags & OPf_SPECIAL)) {
d008e5eb 1327 if (ckWARN(WARN_SYNTAX)) {
6867be6d 1328 const line_t oldline = CopLINE(PL_curcop);
a0d0e21e 1329
2b7cddde
NC
1330 if (PL_parser && PL_parser->copline != NOLINE) {
1331 /* This ensures that warnings are reported at the first line
1332 of the conditional, not the last. */
53a7735b 1333 CopLINE_set(PL_curcop, PL_parser->copline);
2b7cddde 1334 }
9014280d 1335 Perl_warner(aTHX_ packWARN(WARN_SYNTAX), "Found = in conditional, should be ==");
57843af0 1336 CopLINE_set(PL_curcop, oldline);
d008e5eb 1337 }
a0d0e21e 1338 }
11343788 1339 return scalar(o);
8990e307
LW
1340}
1341
0920b7fa
FC
1342static SV *
1343S_op_varname(pTHX_ const OP *o)
1344{
1345 assert(o);
1346 assert(o->op_type == OP_PADAV || o->op_type == OP_RV2AV ||
1347 o->op_type == OP_PADHV || o->op_type == OP_RV2HV);
1348 {
1349 const char funny = o->op_type == OP_PADAV
1350 || o->op_type == OP_RV2AV ? '@' : '%';
1351 if (o->op_type == OP_RV2AV || o->op_type == OP_RV2HV) {
1352 GV *gv;
1353 if (cUNOPo->op_first->op_type != OP_GV
1354 || !(gv = cGVOPx_gv(cUNOPo->op_first)))
1355 return NULL;
1356 return varname(gv, funny, 0, NULL, 0, 1);
1357 }
1358 return
1359 varname(MUTABLE_GV(PL_compcv), funny, o->op_targ, NULL, 0, 1);
1360 }
1361}
1362
429a2555 1363static void
2186f873
FC
1364S_op_pretty(pTHX_ const OP *o, SV **retsv, const char **retpv)
1365{ /* or not so pretty :-) */
2186f873
FC
1366 if (o->op_type == OP_CONST) {
1367 *retsv = cSVOPo_sv;
1368 if (SvPOK(*retsv)) {
1369 SV *sv = *retsv;
1370 *retsv = sv_newmortal();
1371 pv_pretty(*retsv, SvPVX_const(sv), SvCUR(sv), 32, NULL, NULL,
1372 PERL_PV_PRETTY_DUMP |PERL_PV_ESCAPE_UNI_DETECT);
1373 }
1374 else if (!SvOK(*retsv))
1375 *retpv = "undef";
1376 }
1377 else *retpv = "...";
1378}
1379
1380static void
429a2555
FC
1381S_scalar_slice_warning(pTHX_ const OP *o)
1382{
1383 OP *kid;
1384 const char lbrack =
2186f873 1385 o->op_type == OP_HSLICE ? '{' : '[';
429a2555 1386 const char rbrack =
2186f873 1387 o->op_type == OP_HSLICE ? '}' : ']';
429a2555 1388 SV *name;
32e9ec8f 1389 SV *keysv = NULL; /* just to silence compiler warnings */
429a2555
FC
1390 const char *key = NULL;
1391
1392 if (!(o->op_private & OPpSLICEWARNING))
1393 return;
1394 if (PL_parser && PL_parser->error_count)
1395 /* This warning can be nonsensical when there is a syntax error. */
1396 return;
1397
1398 kid = cLISTOPo->op_first;
1ed44841 1399 kid = OP_SIBLING(kid); /* get past pushmark */
429a2555
FC
1400 /* weed out false positives: any ops that can return lists */
1401 switch (kid->op_type) {
1402 case OP_BACKTICK:
1403 case OP_GLOB:
1404 case OP_READLINE:
1405 case OP_MATCH:
1406 case OP_RV2AV:
1407 case OP_EACH:
1408 case OP_VALUES:
1409 case OP_KEYS:
1410 case OP_SPLIT:
1411 case OP_LIST:
1412 case OP_SORT:
1413 case OP_REVERSE:
1414 case OP_ENTERSUB:
1415 case OP_CALLER:
1416 case OP_LSTAT:
1417 case OP_STAT:
1418 case OP_READDIR:
1419 case OP_SYSTEM:
1420 case OP_TMS:
1421 case OP_LOCALTIME:
1422 case OP_GMTIME:
1423 case OP_ENTEREVAL:
1424 case OP_REACH:
1425 case OP_RKEYS:
1426 case OP_RVALUES:
1427 return;
1428 }
7d3c8a68
SM
1429
1430 /* Don't warn if we have a nulled list either. */
1431 if (kid->op_type == OP_NULL && kid->op_targ == OP_LIST)
1432 return;
1433
1ed44841
DM
1434 assert(OP_SIBLING(kid));
1435 name = S_op_varname(aTHX_ OP_SIBLING(kid));
429a2555
FC
1436 if (!name) /* XS module fiddling with the op tree */
1437 return;
2186f873 1438 S_op_pretty(aTHX_ kid, &keysv, &key);
429a2555
FC
1439 assert(SvPOK(name));
1440 sv_chop(name,SvPVX(name)+1);
1441 if (key)
2186f873 1442 /* diag_listed_as: Scalar value @%s[%s] better written as $%s[%s] */
429a2555 1443 Perl_warner(aTHX_ packWARN(WARN_SYNTAX),
2186f873 1444 "Scalar value @%"SVf"%c%s%c better written as $%"SVf
429a2555 1445 "%c%s%c",
2186f873 1446 SVfARG(name), lbrack, key, rbrack, SVfARG(name),
429a2555
FC
1447 lbrack, key, rbrack);
1448 else
2186f873 1449 /* diag_listed_as: Scalar value @%s[%s] better written as $%s[%s] */
429a2555 1450 Perl_warner(aTHX_ packWARN(WARN_SYNTAX),
2186f873 1451 "Scalar value @%"SVf"%c%"SVf"%c better written as $%"
429a2555 1452 SVf"%c%"SVf"%c",
c1f6cd39
BF
1453 SVfARG(name), lbrack, SVfARG(keysv), rbrack,
1454 SVfARG(name), lbrack, SVfARG(keysv), rbrack);
429a2555
FC
1455}
1456
8990e307 1457OP *
864dbfa3 1458Perl_scalar(pTHX_ OP *o)
79072805
LW
1459{
1460 OP *kid;
1461
a0d0e21e 1462 /* assumes no premature commitment */
13765c85
DM
1463 if (!o || (PL_parser && PL_parser->error_count)
1464 || (o->op_flags & OPf_WANT)
5dc0d613 1465 || o->op_type == OP_RETURN)
7e363e51 1466 {
11343788 1467 return o;
7e363e51 1468 }
79072805 1469
5dc0d613 1470 o->op_flags = (o->op_flags & ~OPf_WANT) | OPf_WANT_SCALAR;
79072805 1471
11343788 1472 switch (o->op_type) {
79072805 1473 case OP_REPEAT:
11343788 1474 scalar(cBINOPo->op_first);
8990e307 1475 break;
79072805
LW
1476 case OP_OR:
1477 case OP_AND:
1478 case OP_COND_EXPR:
1ed44841 1479 for (kid = OP_SIBLING(cUNOPo->op_first); kid; kid = OP_SIBLING(kid))
8990e307 1480 scalar(kid);
79072805 1481 break;
924ba076 1482 /* FALLTHROUGH */
a6d8037e 1483 case OP_SPLIT:
79072805 1484 case OP_MATCH:
8782bef2 1485 case OP_QR:
79072805
LW
1486 case OP_SUBST:
1487 case OP_NULL:
8990e307 1488 default:
11343788 1489 if (o->op_flags & OPf_KIDS) {
1ed44841 1490 for (kid = cUNOPo->op_first; kid; kid = OP_SIBLING(kid))
8990e307
LW
1491 scalar(kid);
1492 }
79072805
LW
1493 break;
1494 case OP_LEAVE:
1495 case OP_LEAVETRY:
5dc0d613 1496 kid = cLISTOPo->op_first;
54310121 1497 scalar(kid);
1ed44841 1498 kid = OP_SIBLING(kid);
25b991bf
VP
1499 do_kids:
1500 while (kid) {
1ed44841 1501 OP *sib = OP_SIBLING(kid);
c08f093b
VP
1502 if (sib && kid->op_type != OP_LEAVEWHEN)
1503 scalarvoid(kid);
1504 else
54310121 1505 scalar(kid);
25b991bf 1506 kid = sib;
54310121 1507 }
11206fdd 1508 PL_curcop = &PL_compiling;
54310121 1509 break;
748a9306 1510 case OP_SCOPE:
79072805 1511 case OP_LINESEQ:
8990e307 1512 case OP_LIST:
25b991bf
VP
1513 kid = cLISTOPo->op_first;
1514 goto do_kids;
a801c63c 1515 case OP_SORT:
a2a5de95 1516 Perl_ck_warner(aTHX_ packWARN(WARN_VOID), "Useless use of sort in scalar context");
553e7bb0 1517 break;
95a31aad
FC
1518 case OP_KVHSLICE:
1519 case OP_KVASLICE:
2186f873
FC
1520 {
1521 /* Warn about scalar context */
1522 const char lbrack = o->op_type == OP_KVHSLICE ? '{' : '[';
1523 const char rbrack = o->op_type == OP_KVHSLICE ? '}' : ']';
1524 SV *name;
1525 SV *keysv;
1526 const char *key = NULL;
1527
1528 /* This warning can be nonsensical when there is a syntax error. */
1529 if (PL_parser && PL_parser->error_count)
1530 break;
1531
1532 if (!ckWARN(WARN_SYNTAX)) break;
1533
1534 kid = cLISTOPo->op_first;
1ed44841
DM
1535 kid = OP_SIBLING(kid); /* get past pushmark */
1536 assert(OP_SIBLING(kid));
1537 name = S_op_varname(aTHX_ OP_SIBLING(kid));
2186f873
FC
1538 if (!name) /* XS module fiddling with the op tree */
1539 break;
1540 S_op_pretty(aTHX_ kid, &keysv, &key);
1541 assert(SvPOK(name));
1542 sv_chop(name,SvPVX(name)+1);
1543 if (key)
1544 /* diag_listed_as: %%s[%s] in scalar context better written as $%s[%s] */
1545 Perl_warner(aTHX_ packWARN(WARN_SYNTAX),
1546 "%%%"SVf"%c%s%c in scalar context better written "
1547 "as $%"SVf"%c%s%c",
1548 SVfARG(name), lbrack, key, rbrack, SVfARG(name),
1549 lbrack, key, rbrack);
1550 else
1551 /* diag_listed_as: %%s[%s] in scalar context better written as $%s[%s] */
1552 Perl_warner(aTHX_ packWARN(WARN_SYNTAX),
1553 "%%%"SVf"%c%"SVf"%c in scalar context better "
1554 "written as $%"SVf"%c%"SVf"%c",
c1f6cd39
BF
1555 SVfARG(name), lbrack, SVfARG(keysv), rbrack,
1556 SVfARG(name), lbrack, SVfARG(keysv), rbrack);
2186f873 1557 }
79072805 1558 }
11343788 1559 return o;
79072805
LW
1560}
1561
1562OP *
864dbfa3 1563Perl_scalarvoid(pTHX_ OP *o)
79072805 1564{
27da23d5 1565 dVAR;
79072805 1566 OP *kid;
095b19d1 1567 SV *useless_sv = NULL;
c445ea15 1568 const char* useless = NULL;
8990e307 1569 SV* sv;
2ebea0a1
GS
1570 U8 want;
1571
7918f24d
NC
1572 PERL_ARGS_ASSERT_SCALARVOID;
1573
acb36ea4 1574 if (o->op_type == OP_NEXTSTATE
acb36ea4
GS
1575 || o->op_type == OP_DBSTATE
1576 || (o->op_type == OP_NULL && (o->op_targ == OP_NEXTSTATE
acb36ea4 1577 || o->op_targ == OP_DBSTATE)))
2ebea0a1 1578 PL_curcop = (COP*)o; /* for warning below */
79072805 1579
54310121 1580 /* assumes no premature commitment */
2ebea0a1 1581 want = o->op_flags & OPf_WANT;
13765c85
DM
1582 if ((want && want != OPf_WANT_SCALAR)
1583 || (PL_parser && PL_parser->error_count)
25b991bf 1584 || o->op_type == OP_RETURN || o->op_type == OP_REQUIRE || o->op_type == OP_LEAVEWHEN)
7e363e51 1585 {
11343788 1586 return o;
7e363e51 1587 }
79072805 1588
b162f9ea 1589 if ((o->op_private & OPpTARGET_MY)
7e363e51
GS
1590 && (PL_opargs[o->op_type] & OA_TARGLEX))/* OPp share the meaning */
1591 {
b162f9ea 1592 return scalar(o); /* As if inside SASSIGN */
7e363e51 1593 }
1c846c1f 1594
5dc0d613 1595 o->op_flags = (o->op_flags & ~OPf_WANT) | OPf_WANT_VOID;
79072805 1596
11343788 1597 switch (o->op_type) {
79072805 1598 default:
22c35a8c 1599 if (!(PL_opargs[o->op_type] & OA_FOLDCONST))
8990e307 1600 break;
924ba076 1601 /* FALLTHROUGH */
36477c24 1602 case OP_REPEAT:
11343788 1603 if (o->op_flags & OPf_STACKED)
8990e307 1604 break;
5d82c453
GA
1605 goto func_ops;
1606 case OP_SUBSTR:
1607 if (o->op_private == 4)
1608 break;
924ba076 1609 /* FALLTHROUGH */
8990e307
LW
1610 case OP_GVSV:
1611 case OP_WANTARRAY:
1612 case OP_GV:
74295f0b 1613 case OP_SMARTMATCH:
8990e307
LW
1614 case OP_PADSV:
1615 case OP_PADAV:
1616 case OP_PADHV:
1617 case OP_PADANY:
1618 case OP_AV2ARYLEN:
8990e307 1619 case OP_REF:
a0d0e21e
LW
1620 case OP_REFGEN:
1621 case OP_SREFGEN:
8990e307
LW
1622 case OP_DEFINED:
1623 case OP_HEX:
1624 case OP_OCT:
1625 case OP_LENGTH:
8990e307
LW
1626 case OP_VEC:
1627 case OP_INDEX:
1628 case OP_RINDEX:
1629 case OP_SPRINTF:
1630 case OP_AELEM:
1631 case OP_AELEMFAST:
93bad3fd 1632 case OP_AELEMFAST_LEX:
8990e307 1633 case OP_ASLICE:
6dd3e0f2 1634 case OP_KVASLICE:
8990e307
LW
1635 case OP_HELEM:
1636 case OP_HSLICE:
5cae3edb 1637 case OP_KVHSLICE:
8990e307
LW
1638 case OP_UNPACK:
1639 case OP_PACK:
8990e307
LW
1640 case OP_JOIN:
1641 case OP_LSLICE:
1642 case OP_ANONLIST:
1643 case OP_ANONHASH:
1644 case OP_SORT:
1645 case OP_REVERSE:
1646 case OP_RANGE:
1647 case OP_FLIP:
1648 case OP_FLOP:
1649 case OP_CALLER:
1650 case OP_FILENO:
1651 case OP_EOF:
1652 case OP_TELL:
1653 case OP_GETSOCKNAME:
1654 case OP_GETPEERNAME:
1655 case OP_READLINK:
1656 case OP_TELLDIR:
1657 case OP_GETPPID:
1658 case OP_GETPGRP:
1659 case OP_GETPRIORITY:
1660 case OP_TIME:
1661 case OP_TMS:
1662 case OP_LOCALTIME:
1663 case OP_GMTIME:
1664 case OP_GHBYNAME:
1665 case OP_GHBYADDR:
1666 case OP_GHOSTENT:
1667 case OP_GNBYNAME:
1668 case OP_GNBYADDR:
1669 case OP_GNETENT:
1670 case OP_GPBYNAME:
1671 case OP_GPBYNUMBER:
1672 case OP_GPROTOENT:
1673 case OP_GSBYNAME:
1674 case OP_GSBYPORT:
1675 case OP_GSERVENT:
1676 case OP_GPWNAM:
1677 case OP_GPWUID:
1678 case OP_GGRNAM:
1679 case OP_GGRGID:
1680 case OP_GETLOGIN:
78e1b766 1681 case OP_PROTOTYPE:
703227f5 1682 case OP_RUNCV:
5d82c453 1683 func_ops:
64aac5a9 1684 if (!(o->op_private & (OPpLVAL_INTRO|OPpOUR_INTRO)))
74295f0b 1685 /* Otherwise it's "Useless use of grep iterator" */
f5df4782 1686 useless = OP_DESC(o);
75068674
RGS
1687 break;
1688
1689 case OP_SPLIT:
1690 kid = cLISTOPo->op_first;
1691 if (kid && kid->op_type == OP_PUSHRE
1692#ifdef USE_ITHREADS
1693 && !((PMOP*)kid)->op_pmreplrootu.op_pmtargetoff)
1694#else
1695 && !((PMOP*)kid)->op_pmreplrootu.op_pmtargetgv)
1696#endif
1697 useless = OP_DESC(o);
8990e307
LW
1698 break;
1699
9f82cd5f
YST
1700 case OP_NOT:
1701 kid = cUNOPo->op_first;
1702 if (kid->op_type != OP_MATCH && kid->op_type != OP_SUBST &&
bb16bae8 1703 kid->op_type != OP_TRANS && kid->op_type != OP_TRANSR) {
9f82cd5f
YST
1704 goto func_ops;
1705 }
1706 useless = "negative pattern binding (!~)";
1707 break;
1708
4f4d7508
DC
1709 case OP_SUBST:
1710 if (cPMOPo->op_pmflags & PMf_NONDESTRUCT)
8db9069c 1711 useless = "non-destructive substitution (s///r)";
4f4d7508
DC
1712 break;
1713
bb16bae8
FC
1714 case OP_TRANSR:
1715 useless = "non-destructive transliteration (tr///r)";
1716 break;
1717
8990e307
LW
1718 case OP_RV2GV:
1719 case OP_RV2SV:
1720 case OP_RV2AV:
1721 case OP_RV2HV:
192587c2 1722 if (!(o->op_private & (OPpLVAL_INTRO|OPpOUR_INTRO)) &&
1ed44841 1723 (!OP_HAS_SIBLING(o) || OP_SIBLING(o)->op_type != OP_READLINE))
8990e307
LW
1724 useless = "a variable";
1725 break;
79072805
LW
1726
1727 case OP_CONST:
7766f137 1728 sv = cSVOPo_sv;
7a52d87a
GS
1729 if (cSVOPo->op_private & OPpCONST_STRICT)
1730 no_bareword_allowed(o);
1731 else {
d008e5eb 1732 if (ckWARN(WARN_VOID)) {
e7fec78e 1733 /* don't warn on optimised away booleans, eg
b5a930ec 1734 * use constant Foo, 5; Foo || print; */
e7fec78e 1735 if (cSVOPo->op_private & OPpCONST_SHORTCIRCUIT)
d4c19fe8 1736 useless = NULL;
960b4253
MG
1737 /* the constants 0 and 1 are permitted as they are
1738 conventionally used as dummies in constructs like
1739 1 while some_condition_with_side_effects; */
659c4b96 1740 else if (SvNIOK(sv) && (SvNV(sv) == 0.0 || SvNV(sv) == 1.0))
d4c19fe8 1741 useless = NULL;
d008e5eb 1742 else if (SvPOK(sv)) {
1e3f3188
KW
1743 SV * const dsv = newSVpvs("");
1744 useless_sv
1745 = Perl_newSVpvf(aTHX_
1746 "a constant (%s)",
1747 pv_pretty(dsv, SvPVX_const(sv),
1748 SvCUR(sv), 32, NULL, NULL,
1749 PERL_PV_PRETTY_DUMP
1750 | PERL_PV_ESCAPE_NOCLEAR
1751 | PERL_PV_ESCAPE_UNI_DETECT));
1752 SvREFCNT_dec_NN(dsv);
d008e5eb 1753 }
919f76a3 1754 else if (SvOK(sv)) {
c1f6cd39 1755 useless_sv = Perl_newSVpvf(aTHX_ "a constant (%"SVf")", SVfARG(sv));
919f76a3
RGS
1756 }
1757 else
1758 useless = "a constant (undef)";
8990e307
LW
1759 }
1760 }
93c66552 1761 op_null(o); /* don't execute or even remember it */
79072805
LW
1762 break;
1763
1764 case OP_POSTINC:
11343788 1765 o->op_type = OP_PREINC; /* pre-increment is faster */
22c35a8c 1766 o->op_ppaddr = PL_ppaddr[OP_PREINC];
79072805
LW
1767 break;
1768
1769 case OP_POSTDEC:
11343788 1770 o->op_type = OP_PREDEC; /* pre-decrement is faster */
22c35a8c 1771 o->op_ppaddr = PL_ppaddr[OP_PREDEC];
79072805
LW
1772 break;
1773
679d6c4e
HS
1774 case OP_I_POSTINC:
1775 o->op_type = OP_I_PREINC; /* pre-increment is faster */
1776 o->op_ppaddr = PL_ppaddr[OP_I_PREINC];
1777 break;
1778
1779 case OP_I_POSTDEC:
1780 o->op_type = OP_I_PREDEC; /* pre-decrement is faster */
1781 o->op_ppaddr = PL_ppaddr[OP_I_PREDEC];
1782 break;
1783
f2f8fd84
GG
1784 case OP_SASSIGN: {
1785 OP *rv2gv;
1786 UNOP *refgen, *rv2cv;
1787 LISTOP *exlist;
1788
1789 if ((o->op_private & ~OPpASSIGN_BACKWARDS) != 2)
1790 break;
1791
1792 rv2gv = ((BINOP *)o)->op_last;
1793 if (!rv2gv || rv2gv->op_type != OP_RV2GV)
1794 break;
1795
1796 refgen = (UNOP *)((BINOP *)o)->op_first;
1797
1798 if (!refgen || refgen->op_type != OP_REFGEN)
1799 break;
1800
1801 exlist = (LISTOP *)refgen->op_first;
1802 if (!exlist || exlist->op_type != OP_NULL
1803 || exlist->op_targ != OP_LIST)
1804 break;
1805
1806 if (exlist->op_first->op_type != OP_PUSHMARK)
1807 break;
1808
1809 rv2cv = (UNOP*)exlist->op_last;
1810
1811 if (rv2cv->op_type != OP_RV2CV)
1812 break;
1813
1814 assert ((rv2gv->op_private & OPpDONT_INIT_GV) == 0);
1815 assert ((o->op_private & OPpASSIGN_CV_TO_GV) == 0);
1816 assert ((rv2cv->op_private & OPpMAY_RETURN_CONSTANT) == 0);
1817
1818 o->op_private |= OPpASSIGN_CV_TO_GV;
1819 rv2gv->op_private |= OPpDONT_INIT_GV;
1820 rv2cv->op_private |= OPpMAY_RETURN_CONSTANT;
1821
1822 break;
1823 }
1824
540dd770
GG
1825 case OP_AASSIGN: {
1826 inplace_aassign(o);
1827 break;
1828 }
1829
79072805
LW
1830 case OP_OR:
1831 case OP_AND:
edbe35ea
VP
1832 kid = cLOGOPo->op_first;
1833 if (kid->op_type == OP_NOT
b5bbe64a 1834 && (kid->op_flags & OPf_KIDS)) {
edbe35ea
VP
1835 if (o->op_type == OP_AND) {
1836 o->op_type = OP_OR;
1837 o->op_ppaddr = PL_ppaddr[OP_OR];
1838 } else {
1839 o->op_type = OP_AND;
1840 o->op_ppaddr = PL_ppaddr[OP_AND];
1841 }
1842 op_null(kid);
1843 }
c67159e1 1844 /* FALLTHROUGH */
edbe35ea 1845
c963b151 1846 case OP_DOR:
79072805 1847 case OP_COND_EXPR:
0d863452
RH
1848 case OP_ENTERGIVEN:
1849 case OP_ENTERWHEN:
1ed44841 1850 for (kid = OP_SIBLING(cUNOPo->op_first); kid; kid = OP_SIBLING(kid))
79072805
LW
1851 scalarvoid(kid);
1852 break;
5aabfad6 1853
a0d0e21e 1854 case OP_NULL:
11343788 1855 if (o->op_flags & OPf_STACKED)
a0d0e21e 1856 break;
924ba076 1857 /* FALLTHROUGH */
2ebea0a1
GS
1858 case OP_NEXTSTATE:
1859 case OP_DBSTATE:
79072805
LW
1860 case OP_ENTERTRY:
1861 case OP_ENTER:
11343788 1862 if (!(o->op_flags & OPf_KIDS))
79072805 1863 break;
924ba076 1864 /* FALLTHROUGH */
463ee0b2 1865 case OP_SCOPE:
79072805
LW
1866 case OP_LEAVE:
1867 case OP_LEAVETRY:
a0d0e21e 1868 case OP_LEAVELOOP:
79072805 1869 case OP_LINESEQ:
79072805 1870 case OP_LIST:
0d863452
RH
1871 case OP_LEAVEGIVEN:
1872 case OP_LEAVEWHEN:
1ed44841 1873 for (kid = cLISTOPo->op_first; kid; kid = OP_SIBLING(kid))
79072805
LW
1874 scalarvoid(kid);
1875 break;
c90c0ff4 1876 case OP_ENTEREVAL:
5196be3e 1877 scalarkids(o);
c90c0ff4 1878 break;
d6483035 1879 case OP_SCALAR:
5196be3e 1880 return scalar(o);
79072805 1881 }
095b19d1
NC
1882
1883 if (useless_sv) {
1884 /* mortalise it, in case warnings are fatal. */
1885 Perl_ck_warner(aTHX_ packWARN(WARN_VOID),
1886 "Useless use of %"SVf" in void context",
c1f6cd39 1887 SVfARG(sv_2mortal(useless_sv)));
095b19d1
NC
1888 }
1889 else if (useless) {
1890 Perl_ck_warner(aTHX_ packWARN(WARN_VOID),
1891 "Useless use of %s in void context",
1892 useless);
1893 }
11343788 1894 return o;
79072805
LW
1895}
1896
1f676739 1897static OP *
412da003 1898S_listkids(pTHX_ OP *o)
79072805 1899{
11343788 1900 if (o && o->op_flags & OPf_KIDS) {
6867be6d 1901 OP *kid;
1ed44841 1902 for (kid = cLISTOPo->op_first; kid; kid = OP_SIBLING(kid))
79072805
LW
1903 list(kid);
1904 }
11343788 1905 return o;
79072805
LW
1906}
1907
1908OP *
864dbfa3 1909Perl_list(pTHX_ OP *o)
79072805
LW
1910{
1911 OP *kid;
1912
a0d0e21e 1913 /* assumes no premature commitment */
13765c85
DM
1914 if (!o || (o->op_flags & OPf_WANT)
1915 || (PL_parser && PL_parser->error_count)
5dc0d613 1916 || o->op_type == OP_RETURN)
7e363e51 1917 {
11343788 1918 return o;
7e363e51 1919 }
79072805 1920
b162f9ea 1921 if ((o->op_private & OPpTARGET_MY)
7e363e51
GS
1922 && (PL_opargs[o->op_type] & OA_TARGLEX))/* OPp share the meaning */
1923 {
b162f9ea 1924 return o; /* As if inside SASSIGN */
7e363e51 1925 }
1c846c1f 1926
5dc0d613 1927 o->op_flags = (o->op_flags & ~OPf_WANT) | OPf_WANT_LIST;
79072805 1928
11343788 1929 switch (o->op_type) {
79072805
LW
1930 case OP_FLOP:
1931 case OP_REPEAT:
11343788 1932 list(cBINOPo->op_first);
79072805
LW
1933 break;
1934 case OP_OR:
1935 case OP_AND:
1936 case OP_COND_EXPR:
1ed44841 1937 for (kid = OP_SIBLING(cUNOPo->op_first); kid; kid = OP_SIBLING(kid))
79072805
LW
1938 list(kid);
1939 break;
1940 default:
1941 case OP_MATCH:
8782bef2 1942 case OP_QR:
79072805
LW
1943 case OP_SUBST:
1944 case OP_NULL:
11343788 1945 if (!(o->op_flags & OPf_KIDS))
79072805 1946 break;
11343788
MB
1947 if (!o->op_next && cUNOPo->op_first->op_type == OP_FLOP) {
1948 list(cBINOPo->op_first);
1949 return gen_constant_list(o);
79072805
LW
1950 }
1951 case OP_LIST:
11343788 1952 listkids(o);
79072805
LW
1953 break;
1954 case OP_LEAVE:
1955 case OP_LEAVETRY:
5dc0d613 1956 kid = cLISTOPo->op_first;
54310121 1957 list(kid);
1ed44841 1958 kid = OP_SIBLING(kid);
25b991bf
VP
1959 do_kids:
1960 while (kid) {
1ed44841 1961 OP *sib = OP_SIBLING(kid);
c08f093b
VP
1962 if (sib && kid->op_type != OP_LEAVEWHEN)
1963 scalarvoid(kid);
1964 else
54310121 1965 list(kid);
25b991bf 1966 kid = sib;
54310121 1967 }
11206fdd 1968 PL_curcop = &PL_compiling;
54310121 1969 break;
748a9306 1970 case OP_SCOPE:
79072805 1971 case OP_LINESEQ:
25b991bf
VP
1972 kid = cLISTOPo->op_first;
1973 goto do_kids;
79072805 1974 }
11343788 1975 return o;
79072805
LW
1976}
1977
1f676739 1978static OP *
2dd5337b 1979S_scalarseq(pTHX_ OP *o)
79072805 1980{
11343788 1981 if (o) {
1496a290
AL
1982 const OPCODE type = o->op_type;
1983
1984 if (type == OP_LINESEQ || type == OP_SCOPE ||
1985 type == OP_LEAVE || type == OP_LEAVETRY)
463ee0b2 1986 {
6867be6d 1987 OP *kid;
1ed44841
DM
1988 for (kid = cLISTOPo->op_first; kid; kid = OP_SIBLING(kid)) {
1989 if (OP_HAS_SIBLING(kid)) {
463ee0b2 1990 scalarvoid(kid);
ed6116ce 1991 }
463ee0b2 1992 }
3280af22 1993 PL_curcop = &PL_compiling;
79072805 1994 }
11343788 1995 o->op_flags &= ~OPf_PARENS;
3280af22 1996 if (PL_hints & HINT_BLOCK_SCOPE)
11343788 1997 o->op_flags |= OPf_PARENS;
79072805 1998 }
8990e307 1999 else
11343788
MB
2000 o = newOP(OP_STUB, 0);
2001 return o;
79072805
LW
2002}
2003
76e3520e 2004STATIC OP *
cea2e8a9 2005S_modkids(pTHX_ OP *o, I32 type)
79072805 2006{
11343788 2007 if (o && o->op_flags & OPf_KIDS) {
6867be6d 2008 OP *kid;
1ed44841 2009 for (kid = cLISTOPo->op_first; kid; kid = OP_SIBLING(kid))
3ad73efd 2010 op_lvalue(kid, type);
79072805 2011 }
11343788 2012 return o;
79072805
LW
2013}
2014
3ad73efd 2015/*
d164302a
GG
2016=for apidoc finalize_optree
2017
72d33970
FC
2018This function finalizes the optree. Should be called directly after
2019the complete optree is built. It does some additional
d164302a
GG
2020checking which can't be done in the normal ck_xxx functions and makes
2021the tree thread-safe.
2022
2023=cut
2024*/
2025void
2026Perl_finalize_optree(pTHX_ OP* o)
2027{
2028 PERL_ARGS_ASSERT_FINALIZE_OPTREE;
2029
2030 ENTER;
2031 SAVEVPTR(PL_curcop);
2032
2033 finalize_op(o);
2034
2035 LEAVE;
2036}
2037
60dde6b2 2038STATIC void
d164302a
GG
2039S_finalize_op(pTHX_ OP* o)
2040{
2041 PERL_ARGS_ASSERT_FINALIZE_OP;
2042
d164302a
GG
2043
2044 switch (o->op_type) {
2045 case OP_NEXTSTATE:
2046 case OP_DBSTATE:
2047 PL_curcop = ((COP*)o); /* for warnings */
2048 break;
2049 case OP_EXEC:
1ed44841
DM
2050 if (OP_HAS_SIBLING(o)) {
2051 OP *sib = OP_SIBLING(o);
2052 if (( sib->op_type == OP_NEXTSTATE || sib->op_type == OP_DBSTATE)
2053 && ckWARN(WARN_EXEC)
2054 && OP_HAS_SIBLING(sib))
2055 {
2056 const OPCODE type = OP_SIBLING(sib)->op_type;
d164302a
GG
2057 if (type != OP_EXIT && type != OP_WARN && type != OP_DIE) {
2058 const line_t oldline = CopLINE(PL_curcop);
1ed44841 2059 CopLINE_set(PL_curcop, CopLINE((COP*)sib));
d164302a
GG
2060 Perl_warner(aTHX_ packWARN(WARN_EXEC),
2061 "Statement unlikely to be reached");
2062 Perl_warner(aTHX_ packWARN(WARN_EXEC),
2063 "\t(Maybe you meant system() when you said exec()?)\n");
2064 CopLINE_set(PL_curcop, oldline);
2065 }
d164302a 2066 }
1ed44841 2067 }
d164302a
GG
2068 break;
2069
2070 case OP_GV:
2071 if ((o->op_private & OPpEARLY_CV) && ckWARN(WARN_PROTOTYPE)) {
2072 GV * const gv = cGVOPo_gv;
2073 if (SvTYPE(gv) == SVt_PVGV && GvCV(gv) && SvPVX_const(GvCV(gv))) {
2074 /* XXX could check prototype here instead of just carping */
2075 SV * const sv = sv_newmortal();
2076 gv_efullname3(sv, gv, NULL);
2077 Perl_warner(aTHX_ packWARN(WARN_PROTOTYPE),
2078 "%"SVf"() called too early to check prototype",
2079 SVfARG(sv));
2080 }
2081 }
2082 break;
2083
2084 case OP_CONST:
eb796c7f
GG
2085 if (cSVOPo->op_private & OPpCONST_STRICT)
2086 no_bareword_allowed(o);
2087 /* FALLTHROUGH */
d164302a
GG
2088#ifdef USE_ITHREADS
2089 case OP_HINTSEVAL:
2090 case OP_METHOD_NAMED:
2091 /* Relocate sv to the pad for thread safety.
2092 * Despite being a "constant", the SV is written to,
2093 * for reference counts, sv_upgrade() etc. */
2094 if (cSVOPo->op_sv) {
325e1816 2095 const PADOFFSET ix = pad_alloc(OP_CONST, SVf_READONLY);
d054cdb0
FC
2096 SvREFCNT_dec(PAD_SVl(ix));
2097 PAD_SETSV(ix, cSVOPo->op_sv);
2098 /* XXX I don't know how this isn't readonly already. */
2099 if (!SvIsCOW(PAD_SVl(ix))) SvREADONLY_on(PAD_SVl(ix));
d164302a
GG
2100 cSVOPo->op_sv = NULL;
2101 o->op_targ = ix;
2102 }
2103#endif
2104 break;
2105
2106 case OP_HELEM: {
2107 UNOP *rop;
2108 SV *lexname;
2109 GV **fields;
565e6f7e
FC
2110 SVOP *key_op;
2111 OP *kid;
2112 bool check_fields;
d164302a 2113
565e6f7e 2114 if ((key_op = cSVOPx(((BINOP*)o)->op_last))->op_type != OP_CONST)
d164302a
GG
2115 break;
2116
2117 rop = (UNOP*)((BINOP*)o)->op_first;
e6307ed0 2118
565e6f7e 2119 goto check_keys;
d164302a 2120
565e6f7e 2121 case OP_HSLICE:
429a2555 2122 S_scalar_slice_warning(aTHX_ o);
c67159e1 2123 /* FALLTHROUGH */
429a2555 2124
c5f75dba 2125 case OP_KVHSLICE:
1ed44841 2126 kid = OP_SIBLING(cLISTOPo->op_first);
71323522 2127 if (/* I bet there's always a pushmark... */
7d3c8a68
SM
2128 OP_TYPE_ISNT_AND_WASNT_NN(kid, OP_LIST)
2129 && OP_TYPE_ISNT_NN(kid, OP_CONST))
2130 {
d164302a 2131 break;
7d3c8a68 2132 }
565e6f7e
FC
2133
2134 key_op = (SVOP*)(kid->op_type == OP_CONST
2135 ? kid
1ed44841 2136 : OP_SIBLING(kLISTOP->op_first));
565e6f7e
FC
2137
2138 rop = (UNOP*)((LISTOP*)o)->op_last;
2139
2140 check_keys:
2141 if (o->op_private & OPpLVAL_INTRO || rop->op_type != OP_RV2HV)
71323522 2142 rop = NULL;
565e6f7e 2143 else if (rop->op_first->op_type == OP_PADSV)
d164302a
GG
2144 /* @$hash{qw(keys here)} */
2145 rop = (UNOP*)rop->op_first;
565e6f7e 2146 else {
d164302a
GG
2147 /* @{$hash}{qw(keys here)} */
2148 if (rop->op_first->op_type == OP_SCOPE
2149 && cLISTOPx(rop->op_first)->op_last->op_type == OP_PADSV)
2150 {
2151 rop = (UNOP*)cLISTOPx(rop->op_first)->op_last;
2152 }
2153 else
71323522 2154 rop = NULL;
d164302a 2155 }
71323522 2156
32e9ec8f 2157 lexname = NULL; /* just to silence compiler warnings */
03acb648
DM
2158 fields = NULL; /* just to silence compiler warnings */
2159
71323522
FC
2160 check_fields =
2161 rop
2162 && (lexname = *av_fetch(PL_comppad_name, rop->op_targ, TRUE),
2163 SvPAD_TYPED(lexname))
2164 && (fields = (GV**)hv_fetchs(SvSTASH(lexname), "FIELDS", FALSE))
2165 && isGV(*fields) && GvHV(*fields);
0e706dd4 2166 for (; key_op;
1ed44841 2167 key_op = (SVOP*)OP_SIBLING(key_op)) {
565e6f7e 2168 SV **svp, *sv;
d164302a
GG
2169 if (key_op->op_type != OP_CONST)
2170 continue;
2171 svp = cSVOPx_svp(key_op);
71323522
FC
2172
2173 /* Make the CONST have a shared SV */
2174 if ((!SvIsCOW_shared_hash(sv = *svp))
2175 && SvTYPE(sv) < SVt_PVMG && SvOK(sv) && !SvROK(sv)) {
2176 SSize_t keylen;
2177 const char * const key = SvPV_const(sv, *(STRLEN*)&keylen);
2178 SV *nsv = newSVpvn_share(key,
2179 SvUTF8(sv) ? -keylen : keylen, 0);
2180 SvREFCNT_dec_NN(sv);
2181 *svp = nsv;
2182 }
2183
2184 if (check_fields
2185 && !hv_fetch_ent(GvHV(*fields), *svp, FALSE, 0)) {
ce16c625 2186 Perl_croak(aTHX_ "No such class field \"%"SVf"\" "
84cf752c 2187 "in variable %"SVf" of type %"HEKf,
ce16c625 2188 SVfARG(*svp), SVfARG(lexname),
84cf752c 2189 HEKfARG(HvNAME_HEK(SvSTASH(lexname))));
d164302a
GG
2190 }
2191 }
2192 break;
2193 }
429a2555
FC
2194 case OP_ASLICE:
2195 S_scalar_slice_warning(aTHX_ o);
2196 break;
a7fd8ef6 2197
d164302a
GG
2198 case OP_SUBST: {
2199 if (cPMOPo->op_pmreplrootu.op_pmreplroot)
2200 finalize_op(cPMOPo->op_pmreplrootu.op_pmreplroot);
2201 break;
2202 }
2203 default:
2204 break;
2205 }
2206
2207 if (o->op_flags & OPf_KIDS) {
2208 OP *kid;
c4b20975
DM
2209
2210#ifdef DEBUGGING
20220689
DM
2211 /* check that op_last points to the last sibling, and that
2212 * the last op_sibling field points back to the parent, and
2213 * that the only ops with KIDS are those which are entitled to
2214 * them */
c4b20975
DM
2215 U32 type = o->op_type;
2216 U32 family;
20220689 2217 bool has_last;
c4b20975
DM
2218
2219 if (type == OP_NULL) {
2220 type = o->op_targ;
2221 /* ck_glob creates a null UNOP with ex-type GLOB
2222 * (which is a list op. So pretend it wasn't a listop */
2223 if (type == OP_GLOB)
2224 type = OP_NULL;
2225 }
2226 family = PL_opargs[type] & OA_CLASS_MASK;
2227
20220689
DM
2228 has_last = ( family == OA_BINOP
2229 || family == OA_LISTOP
2230 || family == OA_PMOP
2231 || family == OA_LOOP
2232 );
2233 assert( has_last /* has op_first and op_last, or ...
2234 ... has (or may have) op_first: */
2235 || family == OA_UNOP
2236 || family == OA_LOGOP
2237 || family == OA_BASEOP_OR_UNOP
2238 || family == OA_FILESTATOP
2239 || family == OA_LOOPEXOP
2240 /* I don't know why SASSIGN is tagged as OA_BASEOP - DAPM */
2241 || type == OP_SASSIGN
2242 || type == OP_CUSTOM
2243 || type == OP_NULL /* new_logop does this */
2244 );
2245 /* XXX list form of 'x' is has a null op_last. This is wrong,
2246 * but requires too much hacking (e.g. in Deparse) to fix for
2247 * now */
2248 if (type == OP_REPEAT && (o->op_private & OPpREPEAT_DOLIST)) {
2249 assert(has_last);
2250 has_last = 0;
2251 }
2252
2253 for (kid = cUNOPo->op_first; kid; kid = OP_SIBLING(kid)) {
29e61fd9 2254# ifdef PERL_OP_PARENT
20220689
DM
2255 if (!OP_HAS_SIBLING(kid)) {
2256 if (has_last)
29e61fd9 2257 assert(kid == cLISTOPo->op_last);
20220689
DM
2258 assert(kid->op_sibling == o);
2259 }
29e61fd9 2260# else
20220689
DM
2261 if (OP_HAS_SIBLING(kid)) {
2262 assert(!kid->op_lastsib);
2263 }
2264 else {
2265 assert(kid->op_lastsib);
2266 if (has_last)
29e61fd9 2267 assert(kid == cLISTOPo->op_last);
c4b20975 2268 }
20220689 2269# endif
c4b20975
DM
2270 }
2271#endif
2272
1ed44841 2273 for (kid = cUNOPo->op_first; kid; kid = OP_SIBLING(kid))
d164302a
GG
2274 finalize_op(kid);
2275 }
2276}
2277
2278/*
3ad73efd
Z
2279=for apidoc Amx|OP *|op_lvalue|OP *o|I32 type
2280
2281Propagate lvalue ("modifiable") context to an op and its children.
2282I<type> represents the context type, roughly based on the type of op that
2283would do the modifying, although C<local()> is represented by OP_NULL,
2284because it has no op type of its own (it is signalled by a flag on
001c3c51
FC
2285the lvalue op).
2286
2287This function detects things that can't be modified, such as C<$x+1>, and
72d33970 2288generates errors for them. For example, C<$x+1 = 2> would cause it to be
001c3c51
FC
2289called with an op of type OP_ADD and a C<type> argument of OP_SASSIGN.
2290
2291It also flags things that need to behave specially in an lvalue context,
2292such as C<$$x = 5> which might have to vivify a reference in C<$x>.
3ad73efd
Z
2293
2294=cut
2295*/
ddeae0f1 2296
375879aa
FC
2297static bool
2298S_vivifies(const OPCODE type)
2299{
2300 switch(type) {
2301 case OP_RV2AV: case OP_ASLICE:
2302 case OP_RV2HV: case OP_KVASLICE:
2303 case OP_RV2SV: case OP_HSLICE:
2304 case OP_AELEMFAST: case OP_KVHSLICE:
2305 case OP_HELEM:
2306 case OP_AELEM:
2307 return 1;
2308 }
2309 return 0;
2310}
2311
79072805 2312OP *
d3d7d28f 2313Perl_op_lvalue_flags(pTHX_ OP *o, I32 type, U32 flags)
79072805 2314{
27da23d5 2315 dVAR;
79072805 2316 OP *kid;
ddeae0f1
DM
2317 /* -1 = error on localize, 0 = ignore localize, 1 = ok to localize */
2318 int localize = -1;
79072805 2319
13765c85 2320 if (!o || (PL_parser && PL_parser->error_count))
11343788 2321 return o;
79072805 2322
b162f9ea 2323 if ((o->op_private & OPpTARGET_MY)
7e363e51
GS
2324 && (PL_opargs[o->op_type] & OA_TARGLEX))/* OPp share the meaning */
2325 {
b162f9ea 2326 return o;
7e363e51 2327 }
1c846c1f 2328
5c906035
GG
2329 assert( (o->op_flags & OPf_WANT) != OPf_WANT_VOID );
2330
69974ce6
FC
2331 if (type == OP_PRTF || type == OP_SPRINTF) type = OP_ENTERSUB;
2332
11343788 2333 switch (o->op_type) {
68dc0745 2334 case OP_UNDEF:
3280af22 2335 PL_modcount++;
5dc0d613 2336 return o;
5f05dabc 2337 case OP_STUB:
b5bbe64a 2338 if ((o->op_flags & OPf_PARENS))
5f05dabc
PP
2339 break;
2340 goto nomod;
a0d0e21e 2341 case OP_ENTERSUB:
f79aa60b 2342 if ((type == OP_UNDEF || type == OP_REFGEN || type == OP_LOCK) &&
11343788
MB
2343 !(o->op_flags & OPf_STACKED)) {
2344 o->op_type = OP_RV2CV; /* entersub => rv2cv */
22c35a8c 2345 o->op_ppaddr = PL_ppaddr[OP_RV2CV];
11343788 2346 assert(cUNOPo->op_first->op_type == OP_NULL);
93c66552 2347 op_null(((LISTOP*)cUNOPo->op_first)->op_first);/* disable pushmark */
79072805
LW
2348 break;
2349 }
cd06dffe 2350 else { /* lvalue subroutine call */
777d9014
FC
2351 o->op_private |= OPpLVAL_INTRO
2352 |(OPpENTERSUB_INARGS * (type == OP_LEAVESUBLV));
e6438c1a 2353 PL_modcount = RETURN_UNLIMITED_NUMBER;
4978d6d9 2354 if (type == OP_GREPSTART || type == OP_ENTERSUB || type == OP_REFGEN) {
d0887bf3 2355 /* Potential lvalue context: */
cd06dffe
GS
2356 o->op_private |= OPpENTERSUB_INARGS;
2357 break;
2358 }
2359 else { /* Compile-time error message: */
2360 OP *kid = cUNOPo->op_first;
2361 CV *cv;
2eaf799e 2362 GV *gv;
cd06dffe 2363
3ea285d1
AL
2364 if (kid->op_type != OP_PUSHMARK) {
2365 if (kid->op_type != OP_NULL || kid->op_targ != OP_LIST)
2366 Perl_croak(aTHX_
2367 "panic: unexpected lvalue entersub "
2368 "args: type/targ %ld:%"UVuf,
2369 (long)kid->op_type, (UV)kid->op_targ);
2370 kid = kLISTOP->op_first;
2371 }
1ed44841
DM
2372 while (OP_HAS_SIBLING(kid))
2373 kid = OP_SIBLING(kid);
cd06dffe 2374 if (!(kid->op_type == OP_NULL && kid->op_targ == OP_RV2CV)) {
cd06dffe
GS
2375 break; /* Postpone until runtime */
2376 }
b2ffa427 2377
cd06dffe
GS
2378 kid = kUNOP->op_first;
2379 if (kid->op_type == OP_NULL && kid->op_targ == OP_RV2SV)
2380 kid = kUNOP->op_first;
b2ffa427 2381 if (kid->op_type == OP_NULL)
cd06dffe
GS
2382 Perl_croak(aTHX_
2383 "Unexpected constant lvalue entersub "
55140b79 2384 "entry via type/targ %ld:%"UVuf,
3d811634 2385 (long)kid->op_type, (UV)kid->op_targ);
cd06dffe 2386 if (kid->op_type != OP_GV) {
cd06dffe
GS
2387 break;
2388 }
b2ffa427 2389
2eaf799e
FC
2390 gv = kGVOP_gv;
2391 cv = isGV(gv)
2392 ? GvCV(gv)
2393 : SvROK(gv) && SvTYPE(SvRV(gv)) == SVt_PVCV
2394 ? MUTABLE_CV(SvRV(gv))
2395 : NULL;
1c846c1f 2396 if (!cv)
da1dff94 2397 break;
cd06dffe
GS
2398 if (CvLVALUE(cv))
2399 break;
2400 }
2401 }
924ba076 2402 /* FALLTHROUGH */
79072805 2403 default:
a0d0e21e 2404 nomod:
f5d552b4 2405 if (flags & OP_LVALUE_NO_CROAK) return NULL;
6fbb66d6 2406 /* grep, foreach, subcalls, refgen */
145b2bbb
FC
2407 if (type == OP_GREPSTART || type == OP_ENTERSUB
2408 || type == OP_REFGEN || type == OP_LEAVESUBLV)
a0d0e21e 2409 break;
cea2e8a9 2410 yyerror(Perl_form(aTHX_ "Can't modify %s in %s",
638bc118 2411 (o->op_type == OP_NULL && (o->op_flags & OPf_SPECIAL)
cd06dffe
GS
2412 ? "do block"
2413 : (o->op_type == OP_ENTERSUB
2414 ? "non-lvalue subroutine call"
53e06cf0 2415 : OP_DESC(o))),
22c35a8c 2416 type ? PL_op_desc[type] : "local"));
11343788 2417 return o;
79072805 2418
a0d0e21e
LW
2419 case OP_PREINC:
2420 case OP_PREDEC:
2421 case OP_POW:
2422 case OP_MULTIPLY:
2423 case OP_DIVIDE:
2424 case OP_MODULO:
2425 case OP_REPEAT:
2426 case OP_ADD:
2427 case OP_SUBTRACT:
2428 case OP_CONCAT:
2429 case OP_LEFT_SHIFT:
2430 case OP_RIGHT_SHIFT:
2431 case OP_BIT_AND:
2432 case OP_BIT_XOR:
2433 case OP_BIT_OR:
2434 case OP_I_MULTIPLY:
2435 case OP_I_DIVIDE:
2436 case OP_I_MODULO:
2437 case OP_I_ADD:
2438 case OP_I_SUBTRACT:
11343788 2439 if (!(o->op_flags & OPf_STACKED))
a0d0e21e 2440 goto nomod;
3280af22 2441 PL_modcount++;
a0d0e21e 2442 break;
b2ffa427 2443
79072805 2444 case OP_COND_EXPR:
ddeae0f1 2445 localize = 1;
1ed44841 2446 for (kid = OP_SIBLING(cUNOPo->op_first); kid; kid = OP_SIBLING(kid))
3ad73efd 2447 op_lvalue(kid, type);
79072805
LW
2448 break;
2449
2450 case OP_RV2AV:
2451 case OP_RV2HV:
11343788 2452 if (type == OP_REFGEN && o->op_flags & OPf_PARENS) {
e6438c1a 2453 PL_modcount = RETURN_UNLIMITED_NUMBER;
11343788 2454 return o; /* Treat \(@foo) like ordinary list. */
748a9306 2455 }
924ba076 2456 /* FALLTHROUGH */
79072805 2457 case OP_RV2GV:
5dc0d613 2458 if (scalar_mod_type(o, type))
3fe9a6f1 2459 goto nomod;
11343788 2460 ref(cUNOPo->op_first, o->op_type);
924ba076 2461 /* FALLTHROUGH */
79072805
LW
2462 case OP_ASLICE:
2463 case OP_HSLICE:
ddeae0f1 2464 localize = 1;
924ba076 2465 /* FALLTHROUGH */
78f9721b 2466 case OP_AASSIGN:
32cbae3f
FC
2467 /* Do not apply the lvsub flag for rv2[ah]v in scalar context. */
2468 if (type == OP_LEAVESUBLV && (
2469 (o->op_type != OP_RV2AV && o->op_type != OP_RV2HV)
2470 || (o->op_flags & OPf_WANT) != OPf_WANT_SCALAR
2471 ))
631dbaa2 2472 o->op_private |= OPpMAYBE_LVSUB;
924ba076 2473 /* FALLTHROUGH */
93a17b20
LW
2474 case OP_NEXTSTATE:
2475 case OP_DBSTATE:
e6438c1a 2476 PL_modcount = RETURN_UNLIMITED_NUMBER;
79072805 2477 break;
5cae3edb 2478 case OP_KVHSLICE:
6dd3e0f2 2479 case OP_KVASLICE:
5cae3edb
RZ
2480 if (type == OP_LEAVESUBLV)
2481 o->op_private |= OPpMAYBE_LVSUB;
2482 goto nomod;
28c5b5bc
RGS
2483 case OP_AV2ARYLEN:
2484 PL_hints |= HINT_BLOCK_SCOPE;
2485 if (type == OP_LEAVESUBLV)
2486 o->op_private |= OPpMAYBE_LVSUB;
2487 PL_modcount++;
2488 break;
463ee0b2 2489 case OP_RV2SV:
aeea060c 2490 ref(cUNOPo->op_first, o->op_type);
ddeae0f1 2491 localize = 1;
924ba076 2492 /* FALLTHROUGH */
79072805 2493 case OP_GV:
3280af22 2494 PL_hints |= HINT_BLOCK_SCOPE;
924ba076 2495 /* FALLTHROUGH */
463ee0b2 2496 case OP_SASSIGN:
bf4b1e52
GS
2497 case OP_ANDASSIGN:
2498 case OP_ORASSIGN:
c963b151 2499 case OP_DORASSIGN:
ddeae0f1
DM
2500 PL_modcount++;
2501 break;
2502
8990e307 2503 case OP_AELEMFAST:
93bad3fd 2504 case OP_AELEMFAST_LEX:
6a077020 2505 localize = -1;
3280af22 2506 PL_modcount++;
8990e307
LW
2507 break;
2508
748a9306
LW
2509 case OP_PADAV:
2510 case OP_PADHV:
e6438c1a 2511 PL_modcount = RETURN_UNLIMITED_NUMBER;
5196be3e
MB
2512 if (type == OP_REFGEN && o->op_flags & OPf_PARENS)
2513 return o; /* Treat \(@foo) like ordinary list. */
2514 if (scalar_mod_type(o, type))
3fe9a6f1 2515 goto nomod;
32cbae3f
FC
2516 if ((o->op_flags & OPf_WANT) != OPf_WANT_SCALAR
2517 && type == OP_LEAVESUBLV)
78f9721b 2518 o->op_private |= OPpMAYBE_LVSUB;
924ba076 2519 /* FALLTHROUGH */
748a9306 2520 case OP_PADSV:
3280af22 2521 PL_modcount++;
ddeae0f1 2522 if (!type) /* local() */
5ede95a0
BF
2523 Perl_croak(aTHX_ "Can't localize lexical variable %"SVf,
2524 PAD_COMPNAME_SV(o->op_targ));
463ee0b2
LW
2525 break;
2526
748a9306 2527 case OP_PUSHMARK:
ddeae0f1 2528 localize = 0;
748a9306 2529 break;
b2ffa427 2530
69969c6f 2531 case OP_KEYS:
d8065907 2532 case OP_RKEYS:
fad4a2e4 2533 if (type != OP_SASSIGN && type != OP_LEAVESUBLV)
69969c6f 2534 goto nomod;
5d82c453
GA
2535 goto lvalue_func;
2536 case OP_SUBSTR:
2537 if (o->op_private == 4) /* don't allow 4 arg substr as lvalue */
2538 goto nomod;
924ba076 2539 /* FALLTHROUGH */
a0d0e21e 2540 case OP_POS:
463ee0b2 2541 case OP_VEC:
fad4a2e4 2542 lvalue_func:
78f9721b
SM
2543 if (type == OP_LEAVESUBLV)
2544 o->op_private |= OPpMAYBE_LVSUB;
11343788 2545 if (o->op_flags & OPf_KIDS)
1ed44841 2546 op_lvalue(OP_SIBLING(cBINOPo->op_first), type);
463ee0b2 2547 break;
a0d0e21e 2548
463ee0b2
LW
2549 case OP_AELEM:
2550 case OP_HELEM:
11343788 2551 ref(cBINOPo->op_first, o->op_type);
68dc0745 2552 if (type == OP_ENTERSUB &&
5dc0d613
MB
2553 !(o->op_private & (OPpLVAL_INTRO | OPpDEREF)))
2554 o->op_private |= OPpLVAL_DEFER;
78f9721b
SM
2555 if (type == OP_LEAVESUBLV)
2556 o->op_private |= OPpMAYBE_LVSUB;
ddeae0f1 2557 localize = 1;
3280af22 2558 PL_modcount++;
463ee0b2
LW
2559 break;
2560
463ee0b2 2561 case OP_LEAVE:
a373464f 2562 case OP_LEAVELOOP:
2ec7f6f2 2563 o->op_private |= OPpLVALUE;
924ba076 2564 /* FALLTHROUGH */
2ec7f6f2 2565 case OP_SCOPE:
463ee0b2 2566 case OP_ENTER:
78f9721b 2567 case OP_LINESEQ:
ddeae0f1 2568 localize = 0;
11343788 2569 if (o->op_flags & OPf_KIDS)
3ad73efd 2570 op_lvalue(cLISTOPo->op_last, type);
a0d0e21e
LW
2571 break;
2572
2573 case OP_NULL:
ddeae0f1 2574 localize = 0;
638bc118
GS
2575 if (o->op_flags & OPf_SPECIAL) /* do BLOCK */
2576 goto nomod;
2577 else if (!(o->op_flags & OPf_KIDS))
463ee0b2 2578 break;
11343788 2579 if (o->op_targ != OP_LIST) {
3ad73efd 2580 op_lvalue(cBINOPo->op_first, type);
a0d0e21e
LW
2581 break;
2582 }
924ba076 2583 /* FALLTHROUGH */
463ee0b2 2584 case OP_LIST:
ddeae0f1 2585 localize = 0;
1ed44841 2586 for (kid = cLISTOPo->op_first; kid; kid = OP_SIBLING(kid))
5c906035
GG
2587 /* elements might be in void context because the list is
2588 in scalar context or because they are attribute sub calls */
2589 if ( (kid->op_flags & OPf_WANT) != OPf_WANT_VOID )
2590 op_lvalue(kid, type);
463ee0b2 2591 break;
78f9721b
SM
2592
2593 case OP_RETURN:
2594 if (type != OP_LEAVESUBLV)
2595 goto nomod;
3ad73efd 2596 break; /* op_lvalue()ing was handled by ck_return() */
1efec5ed
FC
2597
2598 case OP_COREARGS:
2599 return o;
2ec7f6f2
FC
2600
2601 case OP_AND:
2602 case OP_OR:
375879aa
FC
2603 if (type == OP_LEAVESUBLV
2604 || !S_vivifies(cLOGOPo->op_first->op_type))
2605 op_lvalue(cLOGOPo->op_first, type);
2606 if (type == OP_LEAVESUBLV
1ed44841
DM
2607 || !S_vivifies(OP_SIBLING(cLOGOPo->op_first)->op_type))
2608 op_lvalue(OP_SIBLING(cLOGOPo->op_first), type);
2ec7f6f2 2609 goto nomod;
463ee0b2 2610 }
58d95175 2611
8be1be90
AMS
2612 /* [20011101.069] File test operators interpret OPf_REF to mean that
2613 their argument is a filehandle; thus \stat(".") should not set
2614 it. AMS 20011102 */
2615 if (type == OP_REFGEN &&
ef69c8fc 2616 PL_check[o->op_type] == Perl_ck_ftst)
8be1be90
AMS
2617 return o;
2618
2619 if (type != OP_LEAVESUBLV)
2620 o->op_flags |= OPf_MOD;
2621
2622 if (type == OP_AASSIGN || type == OP_SASSIGN)
2623 o->op_flags |= OPf_SPECIAL|OPf_REF;
ddeae0f1
DM
2624 else if (!type) { /* local() */
2625 switch (localize) {
2626 case 1:
2627 o->op_private |= OPpLVAL_INTRO;
2628 o->op_flags &= ~OPf_SPECIAL;
2629 PL_hints |= HINT_BLOCK_SCOPE;
2630 break;
2631 case 0:
2632 break;
2633 case -1:
a2a5de95
NC
2634 Perl_ck_warner(aTHX_ packWARN(WARN_SYNTAX),
2635 "Useless localization of %s", OP_DESC(o));
ddeae0f1 2636 }
463ee0b2 2637 }
8be1be90
AMS
2638 else if (type != OP_GREPSTART && type != OP_ENTERSUB
2639 && type != OP_LEAVESUBLV)
2640 o->op_flags |= OPf_REF;
11343788 2641 return o;
463ee0b2
LW
2642}
2643
864dbfa3 2644STATIC bool
5f66b61c 2645S_scalar_mod_type(const OP *o, I32 type)
3fe9a6f1
PP
2646{
2647 switch (type) {
32a60974 2648 case OP_POS:
3fe9a6f1 2649 case OP_SASSIGN:
1efec5ed 2650 if (o && o->op_type == OP_RV2GV)
3fe9a6f1 2651 return FALSE;
924ba076 2652 /* FALLTHROUGH */
3fe9a6f1
PP
2653 case OP_PREINC:
2654 case OP_PREDEC:
2655 case OP_POSTINC:
2656 case OP_POSTDEC:
2657 case OP_I_PREINC:
2658 case OP_I_PREDEC:
2659 case OP_I_POSTINC:
2660 case OP_I_POSTDEC:
2661 case OP_POW:
2662 case OP_MULTIPLY:
2663 case OP_DIVIDE:
2664 case OP_MODULO:
2665 case OP_REPEAT:
2666 case OP_ADD:
2667 case OP_SUBTRACT:
2668 case OP_I_MULTIPLY:
2669 case OP_I_DIVIDE:
2670 case OP_I_MODULO:
2671 case OP_I_ADD:
2672 case OP_I_SUBTRACT:
2673 case OP_LEFT_SHIFT:
2674 case OP_RIGHT_SHIFT:
2675 case OP_BIT_AND:
2676 case OP_BIT_XOR:
2677 case OP_BIT_OR:
2678 case OP_CONCAT:
2679 case OP_SUBST:
2680 case OP_TRANS:
bb16bae8 2681 case OP_TRANSR:
49e9fbe6
GS
2682 case OP_READ:
2683 case OP_SYSREAD:
2684 case OP_RECV:
bf4b1e52
GS
2685 case OP_ANDASSIGN:
2686 case OP_ORASSIGN:
410d09fe 2687 case OP_DORASSIGN:
3fe9a6f1
PP
2688 return TRUE;
2689 default:
2690 return FALSE;
2691 }
2692}
2693
35cd451c 2694STATIC bool
5f66b61c 2695S_is_handle_constructor(const OP *o, I32 numargs)
35cd451c 2696{
7918f24d
NC
2697 PERL_ARGS_ASSERT_IS_HANDLE_CONSTRUCTOR;
2698
35cd451c
GS
2699 switch (o->op_type) {
2700 case OP_PIPE_OP:
2701 case OP_SOCKPAIR:
504618e9 2702 if (numargs == 2)
35cd451c 2703 return TRUE;
924ba076 2704 /* FALLTHROUGH */
35cd451c
GS
2705 case OP_SYSOPEN:
2706 case OP_OPEN:
ded8aa31 2707 case OP_SELECT: /* XXX c.f. SelectSaver.pm */
35cd451c
GS
2708 case OP_SOCKET:
2709 case OP_OPEN_DIR:
2710 case OP_ACCEPT:
504618e9 2711 if (numargs == 1)
35cd451c 2712 return TRUE;
5f66b61c 2713 /* FALLTHROUGH */
35cd451c
GS
2714 default:
2715 return FALSE;
2716 }
2717}
2718
0d86688d
NC
2719static OP *
2720S_refkids(pTHX_ OP *o, I32 type)
463ee0b2 2721{
11343788 2722 if (o && o->op_flags & OPf_KIDS) {
6867be6d 2723 OP *kid;
1ed44841 2724 for (kid = cLISTOPo->op_first; kid; kid = OP_SIBLING(kid))
463ee0b2
LW
2725 ref(kid, type);
2726 }
11343788 2727 return o;
463ee0b2
LW
2728}
2729
2730OP *
e4c5ccf3 2731Perl_doref(pTHX_ OP *o, I32 type, bool set_op_ref)
463ee0b2 2732{
27da23d5 2733 dVAR;
463ee0b2 2734 OP *kid;
463ee0b2 2735
7918f24d
NC
2736 PERL_ARGS_ASSERT_DOREF;
2737
13765c85 2738 if (!o || (PL_parser && PL_parser->error_count))
11343788 2739 return o;
463ee0b2 2740
11343788 2741 switch (o->op_type) {
a0d0e21e 2742 case OP_ENTERSUB:
f4df43b5 2743 if ((type == OP_EXISTS || type == OP_DEFINED) &&
11343788
MB
2744 !(o->op_flags & OPf_STACKED)) {
2745 o->op_type = OP_RV2CV; /* entersub => rv2cv */
22c35a8c 2746 o->op_ppaddr = PL_ppaddr[OP_RV2CV];
11343788 2747 assert(cUNOPo->op_first->op_type == OP_NULL);
93c66552 2748 op_null(((LISTOP*)cUNOPo->op_first)->op_first); /* disable pushmark */
11343788 2749 o->op_flags |= OPf_SPECIAL;
8990e307 2750 }
767eda44 2751 else if (type == OP_RV2SV || type == OP_RV2AV || type == OP_RV2HV){
0e9700df
GG
2752 o->op_private |= (type == OP_RV2AV ? OPpDEREF_AV
2753 : type == OP_RV2HV ? OPpDEREF_HV
2754 : OPpDEREF_SV);
767eda44
FC
2755 o->op_flags |= OPf_MOD;
2756 }
2757
8990e307 2758 break;
aeea060c 2759
463ee0b2 2760 case OP_COND_EXPR:
1ed44841 2761 for (kid = OP_SIBLING(cUNOPo->op_first); kid; kid = OP_SIBLING(kid))
e4c5ccf3 2762 doref(kid, type, set_op_ref);
463ee0b2 2763 break;
8990e307 2764 case OP_RV2SV:
35cd451c
GS
2765 if (type == OP_DEFINED)
2766 o->op_flags |= OPf_SPECIAL; /* don't create GV */
e4c5ccf3 2767 doref(cUNOPo->op_first, o->op_type, set_op_ref);
924ba076 2768 /* FALLTHROUGH */
4633a7c4 2769 case OP_PADSV:
5f05dabc 2770 if (type == OP_RV2SV || type == OP_RV2AV || type == OP_RV2HV) {
5dc0d613
MB
2771 o->op_private |= (type == OP_RV2AV ? OPpDEREF_AV
2772 : type == OP_RV2HV ? OPpDEREF_HV
2773 : OPpDEREF_SV);
11343788 2774 o->op_flags |= OPf_MOD;
a0d0e21e 2775 }
8990e307 2776 break;
1c846c1f 2777
463ee0b2
LW
2778 case OP_RV2AV:
2779 case OP_RV2HV:
e4c5ccf3
RH
2780 if (set_op_ref)
2781 o->op_flags |= OPf_REF;
924ba076 2782 /* FALLTHROUGH */
463ee0b2 2783 case OP_RV2GV:
35cd451c
GS
2784 if (type == OP_DEFINED)
2785 o->op_flags |= OPf_SPECIAL; /* don't create GV */
e4c5ccf3 2786 doref(cUNOPo->op_first, o->op_type, set_op_ref);
463ee0b2 2787 break;
8990e307 2788
463ee0b2
LW
2789 case OP_PADAV:
2790 case OP_PADHV:
e4c5ccf3
RH
2791 if (set_op_ref)
2792 o->op_flags |= OPf_REF;
79072805 2793 break;
aeea060c 2794
8990e307 2795 case OP_SCALAR:
79072805 2796 case OP_NULL:
518618af 2797 if (!(o->op_flags & OPf_KIDS) || type == OP_DEFINED)
463ee0b2 2798 break;
e4c5ccf3 2799 doref(cBINOPo->op_first, type, set_op_ref);
79072805
LW
2800 break;
2801 case OP_AELEM:
2802 case OP_HELEM:
e4c5ccf3 2803 doref(cBINOPo->op_first, o->op_type, set_op_ref);
5f05dabc 2804 if (type == OP_RV2SV || type == OP_RV2AV || type == OP_RV2HV) {
5dc0d613
MB
2805 o->op_private |= (type == OP_RV2AV ? OPpDEREF_AV
2806 : type == OP_RV2HV ? OPpDEREF_HV
2807 : OPpDEREF_SV);
11343788 2808 o->op_flags |= OPf_MOD;
8990e307 2809 }
79072805
LW
2810 break;
2811
463ee0b2 2812 case OP_SCOPE:
79072805 2813 case OP_LEAVE:
e4c5ccf3 2814 set_op_ref = FALSE;
924ba076 2815 /* FALLTHROUGH */
79072805 2816 case OP_ENTER:
8990e307 2817 case OP_LIST:
11343788 2818 if (!(o->op_flags & OPf_KIDS))
79072805 2819 break;
e4c5ccf3 2820 doref(cLISTOPo->op_last, type, set_op_ref);
79072805 2821 break;
a0d0e21e
LW
2822 default:
2823 break;
79072805 2824 }
11343788 2825 return scalar(o);
8990e307 2826
79072805
LW
2827}
2828
09bef843
SB
2829STATIC OP *
2830S_dup_attrlist(pTHX_ OP *o)
2831{
0bd48802 2832 OP *rop;
09bef843 2833
7918f24d
NC
2834 PERL_ARGS_ASSERT_DUP_ATTRLIST;
2835
09bef843
SB
2836 /* An attrlist is either a simple OP_CONST or an OP_LIST with kids,
2837 * where the first kid is OP_PUSHMARK and the remaining ones
2838 * are OP_CONST. We need to push the OP_CONST values.
2839 */
2840 if (o->op_type == OP_CONST)
b37c2d43 2841 rop = newSVOP(OP_CONST, o->op_flags, SvREFCNT_inc_NN(cSVOPo->op_sv));
09bef843
SB
2842 else {
2843 assert((o->op_type == OP_LIST) && (o->op_flags & OPf_KIDS));
5f66b61c 2844 rop = NULL;
1ed44841 2845 for (o = cLISTOPo->op_first; o; o = OP_SIBLING(o)) {
09bef843 2846 if (o->op_type == OP_CONST)
2fcb4757 2847 rop = op_append_elem(OP_LIST, rop,
09bef843 2848 newSVOP(OP_CONST, o->op_flags,
b37c2d43 2849 SvREFCNT_inc_NN(cSVOPo->op_sv)));
09bef843
SB
2850 }
2851 }
2852 return rop;
2853}
2854
2855STATIC void
ad0dc73b 2856S_apply_attrs(pTHX_ HV *stash, SV *target, OP *attrs)
09bef843 2857{
ad0dc73b 2858 SV * const stashsv = stash ? newSVhek(HvNAME_HEK(stash)) : &PL_sv_no;
09bef843 2859
7918f24d
NC
2860 PERL_ARGS_ASSERT_APPLY_ATTRS;
2861
09bef843 2862 /* fake up C<use attributes $pkg,$rv,@attrs> */
e4783991 2863
09bef843 2864#define ATTRSMODULE "attributes"
95f0a2f1
SB
2865#define ATTRSMODULE_PM "attributes.pm"
2866
ad0dc73b 2867 Perl_load_module(aTHX_ PERL_LOADMOD_IMPORT_OPS,
6136c704
AL
2868 newSVpvs(ATTRSMODULE),
2869 NULL,
2fcb4757 2870 op_prepend_elem(OP_LIST,
95f0a2f1 2871 newSVOP(OP_CONST, 0, stashsv),
2fcb4757 2872 op_prepend_elem(OP_LIST,
95f0a2f1
SB
2873 newSVOP(OP_CONST, 0,
2874 newRV(target)),
2875 dup_attrlist(attrs))));
09bef843
SB
2876}
2877
95f0a2f1
SB
2878STATIC void
2879S_apply_attrs_my(pTHX_ HV *stash, OP *target, OP *attrs, OP **imopsp)
2880{
2881 OP *pack, *imop, *arg;
ad0dc73b 2882 SV *meth, *stashsv, **svp;
95f0a2f1 2883
7918f24d
NC
2884 PERL_ARGS_ASSERT_APPLY_ATTRS_MY;
2885
95f0a2f1
SB
2886 if (!attrs)
2887 return;
2888
2889 assert(target->op_type == OP_PADSV ||
2890 target->op_type == OP_PADHV ||
2891 target->op_type == OP_PADAV);
2892
2893 /* Ensure that attributes.pm is loaded. */
ad0dc73b
FC
2894 /* Don't force the C<use> if we don't need it. */
2895 svp = hv_fetchs(GvHVn(PL_incgv), ATTRSMODULE_PM, FALSE);
2896 if (svp && *svp != &PL_sv_undef)
2897 NOOP; /* already in %INC */
2898 else
2899 Perl_load_module(aTHX_ PERL_LOADMOD_NOIMPORT,
2900 newSVpvs(ATTRSMODULE), NULL);
95f0a2f1
SB
2901
2902 /* Need package name for method call. */
6136c704 2903 pack = newSVOP(OP_CONST, 0, newSVpvs(ATTRSMODULE));
95f0a2f1
SB
2904
2905 /* Build up the real arg-list. */
5aaec2b4
NC
2906 stashsv = stash ? newSVhek(HvNAME_HEK(stash)) : &PL_sv_no;
2907
95f0a2f1
SB
2908 arg = newOP(OP_PADSV, 0);
2909 arg->op_targ = target->op_targ;
2fcb4757 2910 arg = op_prepend_elem(OP_LIST,
95f0a2f1 2911 newSVOP(OP_CONST, 0, stashsv),
2fcb4757 2912 op_prepend_elem(OP_LIST,
95f0a2f1 2913 newUNOP(OP_REFGEN, 0,
3ad73efd 2914 op_lvalue(arg, OP_REFGEN)),
95f0a2f1
SB
2915 dup_attrlist(attrs)));
2916
2917 /* Fake up a method call to import */
18916d0d 2918 meth = newSVpvs_share("import");
95f0a2f1 2919 imop = convert(OP_ENTERSUB, OPf_STACKED|OPf_SPECIAL|OPf_WANT_VOID,
2fcb4757
Z
2920 op_append_elem(OP_LIST,
2921 op_prepend_elem(OP_LIST, pack, list(arg)),
95f0a2f1 2922 newSVOP(OP_METHOD_NAMED, 0, meth)));
95f0a2f1
SB
2923
2924 /* Combine the ops. */
2fcb4757 2925 *imopsp = op_append_elem(OP_LIST, *imopsp, imop);
95f0a2f1
SB
2926}
2927
2928/*
2929=notfor apidoc apply_attrs_string
2930
2931Attempts to apply a list of attributes specified by the C<attrstr> and
2932C<len> arguments to the subroutine identified by the C<cv> argument which
2933is expected to be associated with the package identified by the C<stashpv>
2934argument (see L<attributes>). It gets this wrong, though, in that it
2935does not correctly identify the boundaries of the individual attribute
2936specifications within C<attrstr>. This is not really intended for the
2937public API, but has to be listed here for systems such as AIX which
2938need an explicit export list for symbols. (It's called from XS code
2939in support of the C<ATTRS:> keyword from F<xsubpp>.) Patches to fix it
2940to respect attribute syntax properly would be welcome.
2941
2942=cut
2943*/
2944
be3174d2 2945void
6867be6d
AL
2946Perl_apply_attrs_string(pTHX_ const char *stashpv, CV *cv,
2947 const char *attrstr, STRLEN len)
be3174d2 2948{
5f66b61c 2949 OP *attrs = NULL;
be3174d2 2950
7918f24d
NC
2951 PERL_ARGS_ASSERT_APPLY_ATTRS_STRING;
2952
be3174d2
GS
2953 if (!len) {
2954 len = strlen(attrstr);
2955 }
2956
2957 while (len) {
2958 for (; isSPACE(*attrstr) && len; --len, ++attrstr) ;
2959 if (len) {
890ce7af 2960 const char * const sstr = attrstr;
be3174d2 2961 for (; !isSPACE(*attrstr) && len; --len, ++attrstr) ;
2fcb4757 2962 attrs = op_append_elem(OP_LIST, attrs,
be3174d2
GS
2963 newSVOP(OP_CONST, 0,
2964 newSVpvn(sstr, attrstr-sstr)));
2965 }
2966 }
2967
2968 Perl_load_module(aTHX_ PERL_LOADMOD_IMPORT_OPS,
6136c704 2969 newSVpvs(ATTRSMODULE),
2fcb4757 2970 NULL, op_prepend_elem(OP_LIST,
be3174d2 2971 newSVOP(OP_CONST, 0, newSVpv(stashpv,0)),
2fcb4757 2972 op_prepend_elem(OP_LIST,
be3174d2 2973 newSVOP(OP_CONST, 0,
ad64d0ec 2974 newRV(MUTABLE_SV(cv))),
be3174d2
GS
2975 attrs)));
2976}
2977
eedb00fa
PM
2978STATIC void
2979S_move_proto_attr(pTHX_ OP **proto, OP **attrs, const GV * name)
2980{
2981 OP *new_proto = NULL;
2982 STRLEN pvlen;
2983 char *pv;
2984 OP *o;
2985
2986 PERL_ARGS_ASSERT_MOVE_PROTO_ATTR;
2987
2988 if (!*attrs)
2989 return;
2990
2991 o = *attrs;
2992 if (o->op_type == OP_CONST) {
2993 pv = SvPV(cSVOPo_sv, pvlen);
2994 if (pvlen >= 10 && memEQ(pv, "prototype(", 10)) {
2995 SV * const tmpsv = newSVpvn_flags(pv + 10, pvlen - 11, SvUTF8(cSVOPo_sv));
2996 SV ** const tmpo = cSVOPx_svp(o);
2997 SvREFCNT_dec(cSVOPo_sv);
2998 *tmpo = tmpsv;
2999 new_proto = o;
3000 *attrs = NULL;
3001 }
3002 } else if (o->op_type == OP_LIST) {
e78bc664 3003 OP * lasto;
eedb00fa 3004 assert(o->op_flags & OPf_KIDS);
e78bc664
PM
3005 lasto = cLISTOPo->op_first;
3006 assert(lasto->op_type == OP_PUSHMARK);
1ed44841 3007 for (o = OP_SIBLING(lasto); o; o = OP_SIBLING(o)) {
eedb00fa
PM
3008 if (o->op_type == OP_CONST) {
3009 pv = SvPV(cSVOPo_sv, pvlen);
3010 if (pvlen >= 10 && memEQ(pv, "prototype(", 10)) {
3011 SV * const tmpsv = newSVpvn_flags(pv + 10, pvlen - 11, SvUTF8(cSVOPo_sv));
3012 SV ** const tmpo = cSVOPx_svp(o);
3013 SvREFCNT_dec(cSVOPo_sv);
3014 *tmpo = tmpsv;
3015 if (new_proto && ckWARN(WARN_MISC)) {
3016 STRLEN new_len;
3017 const char * newp = SvPV(cSVOPo_sv, new_len);
3018 Perl_warner(aTHX_ packWARN(WARN_MISC),
3019 "Attribute prototype(%"UTF8f") discards earlier prototype attribute in same sub",
3020 UTF8fARG(SvUTF8(cSVOPo_sv), new_len, newp));
3021 op_free(new_proto);
3022 }
3023 else if (new_proto)
3024 op_free(new_proto);
3025 new_proto = o;
3253bf85
DM
3026 /* excise new_proto from the list */
3027 op_sibling_splice(*attrs, lasto, 1, NULL);
3028 o = lasto;
eedb00fa
PM
3029 continue;
3030 }
3031 }
3032 lasto = o;
3033 }
3034 /* If the list is now just the PUSHMARK, scrap the whole thing; otherwise attributes.xs
3035 would get pulled in with no real need */
1ed44841 3036 if (!OP_HAS_SIBLING(cLISTOPx(*attrs)->op_first)) {
eedb00fa
PM
3037 op_free(*attrs);
3038 *attrs = NULL;
3039 }
3040 }
3041
3042 if (new_proto) {
3043 SV *svname;
3044 if (isGV(name)) {
3045 svname = sv_newmortal();
3046 gv_efullname3(svname, name, NULL);
3047 }
3048 else if (SvPOK(name) && *SvPVX((SV *)name) == '&')
3049 svname = newSVpvn_flags(SvPVX((SV *)name)+1, SvCUR(name)-1, SvUTF8(name)|SVs_TEMP);
3050 else
3051 svname = (SV *)name;
3052 if (ckWARN(WARN_ILLEGALPROTO))
3053 (void)validate_proto(svname, cSVOPx_sv(new_proto), TRUE);
3054 if (*proto && ckWARN(WARN_PROTOTYPE)) {
3055 STRLEN old_len, new_len;
3056 const char * oldp = SvPV(cSVOPx_sv(*proto), old_len);
3057 const char * newp = SvPV(cSVOPx_sv(new_proto), new_len);
3058
3059 Perl_warner(aTHX_ packWARN(WARN_PROTOTYPE),
3060 "Prototype '%"UTF8f"' overridden by attribute 'prototype(%"UTF8f")'"
3061 " in %"SVf,
3062 UTF8fARG(SvUTF8(cSVOPx_sv(*proto)), old_len, oldp),
3063 UTF8fARG(SvUTF8(cSVOPx_sv(new_proto)), new_len, newp),
3064 SVfARG(svname));
3065 }
3066 if (*proto)
3067 op_free(*proto);
3068 *proto = new_proto;
3069 }
3070}
3071
92bd82a0
FC
3072static void
3073S_cant_declare(pTHX_ OP *o)
3074{
4748e002
FC
3075 if (o->op_type == OP_NULL
3076 && (o->op_flags & (OPf_SPECIAL|OPf_KIDS)) == OPf_KIDS)
3077 o = cUNOPo->op_first;
92bd82a0 3078 yyerror(Perl_form(aTHX_ "Can't declare %s in \"%s\"",
4748e002
FC
3079 o->op_type == OP_NULL
3080 && o->op_flags & OPf_SPECIAL
3081 ? "do block"
3082 : OP_DESC(o),
92bd82a0
FC
3083 PL_parser->in_my == KEY_our ? "our" :
3084 PL_parser->in_my == KEY_state ? "state" :
3085 "my"));
3086}
3087
09bef843 3088STATIC OP *
95f0a2f1 3089S_my_kid(pTHX_ OP *o, OP *attrs, OP **imopsp)
93a17b20 3090{
93a17b20 3091 I32 type;
a1fba7eb 3092 const bool stately = PL_parser && PL_parser->in_my == KEY_state;
93a17b20 3093
7918f24d
NC
3094 PERL_ARGS_ASSERT_MY_KID;
3095
13765c85 3096 if (!o || (PL_parser && PL_parser->error_count))
11343788 3097 return o;
93a17b20 3098
bc61e325 3099 type = o->op_type;
eb8433b7 3100
93a17b20 3101 if (type == OP_LIST) {
6867be6d 3102 OP *kid;
1ed44841 3103 for (kid = cLISTOPo->op_first; kid; kid = OP_SIBLING(kid))
95f0a2f1 3104 my_kid(kid, attrs, imopsp);
0865059d 3105 return o;
8b8c1fb9 3106 } else if (type == OP_UNDEF || type == OP_STUB) {
7766148a 3107 return o;
77ca0c92
LW
3108 } else if (type == OP_RV2SV || /* "our" declaration */
3109 type == OP_RV2AV ||
3110 type == OP_RV2HV) { /* XXX does this let anything illegal in? */
1ce0b88c 3111 if (cUNOPo->op_first->op_type != OP_GV) { /* MJD 20011224 */
92bd82a0 3112 S_cant_declare(aTHX_ o);
1ce0b88c 3113 } else if (attrs) {
551405c4 3114 GV * const gv = cGVOPx_gv(cUNOPo->op_first);
316ebaf2 3115 assert(PL_parser);
12bd6ede
DM
3116 PL_parser->in_my = FALSE;
3117 PL_parser->in_my_stash = NULL;
1ce0b88c
RGS
3118 apply_attrs(GvSTASH(gv),
3119 (type == OP_RV2SV ? GvSV(gv) :
ad64d0ec
NC
3120 type == OP_RV2AV ? MUTABLE_SV(GvAV(gv)) :
3121 type == OP_RV2HV ? MUTABLE_SV(GvHV(gv)) : MUTABLE_SV(gv)),
ad0dc73b 3122 attrs);
1ce0b88c 3123 }
192587c2 3124 o->op_private |= OPpOUR_INTRO;
77ca0c92 3125 return o;
95f0a2f1
SB
3126 }
3127 else if (type != OP_PADSV &&
93a17b20
LW
3128 type != OP_PADAV &&
3129 type != OP_PADHV &&
3130 type != OP_PUSHMARK)
3131 {
92bd82a0 3132 S_cant_declare(aTHX_ o);
11343788 3133 return o;
93a17b20 3134 }
09bef843
SB
3135 else if (attrs && type != OP_PUSHMARK) {
3136 HV *stash;
09bef843 3137
316ebaf2 3138 assert(PL_parser);
12bd6ede
DM
3139 PL_parser->in_my = FALSE;
3140 PL_parser->in_my_stash = NULL;
eb64745e 3141
09bef843 3142 /* check for C<my Dog $spot> when deciding package */
dd2155a4
DM
3143 stash = PAD_COMPNAME_TYPE(o->op_targ);
3144 if (!stash)
09bef843 3145 stash = PL_curstash;
95f0a2f1 3146 apply_attrs_my(stash, o, attrs, imopsp);
09bef843 3147 }
11343788
MB
3148 o->op_flags |= OPf_MOD;
3149 o->op_private |= OPpLVAL_INTRO;
a1fba7eb 3150 if (stately)
952306ac 3151 o->op_private |= OPpPAD_STATE;
11343788 3152 return o;
93a17b20
LW
3153}
3154
3155OP *
09bef843
SB
3156Perl_my_attrs(pTHX_ OP *o, OP *attrs)
3157{
0bd48802 3158 OP *rops;
95f0a2f1
SB
3159 int maybe_scalar = 0;
3160
7918f24d
NC
3161 PERL_ARGS_ASSERT_MY_ATTRS;
3162
d2be0de5 3163/* [perl #17376]: this appears to be premature, and results in code such as
c754c3d7 3164 C< our(%x); > executing in list mode rather than void mode */
d2be0de5 3165#if 0
09bef843
SB
3166 if (o->op_flags & OPf_PARENS)
3167 list(o);
95f0a2f1
SB
3168 else
3169 maybe_scalar = 1;
d2be0de5
YST
3170#else
3171 maybe_scalar = 1;
3172#endif
09bef843
SB
3173 if (attrs)
3174 SAVEFREEOP(attrs);
5f66b61c 3175 rops = NULL;
95f0a2f1
SB
3176 o = my_kid(o, attrs, &rops);
3177 if (rops) {
3178 if (maybe_scalar && o->op_type == OP_PADSV) {
2fcb4757 3179 o = scalar(op_append_list(OP_LIST, rops, o));
95f0a2f1
SB
3180 o->op_private |= OPpLVAL_INTRO;
3181 }
f5d1ed10
FC
3182 else {
3183 /* The listop in rops might have a pushmark at the beginning,
3184 which will mess up list assignment. */
3185 LISTOP * const lrops = (LISTOP *)rops; /* for brevity */
3186 if (rops->op_type == OP_LIST &&
3187 lrops->op_first && lrops->op_first->op_type == OP_PUSHMARK)
3188 {
3189 OP * const pushmark = lrops->op_first;
3253bf85
DM
3190 /* excise pushmark */
3191 op_sibling_splice(rops, NULL, 1, NULL);
f5d1ed10
FC
3192 op_free(pushmark);
3193 }
2fcb4757 3194 o = op_append_list(OP_LIST, o, rops);
f5d1ed10 3195 }
95f0a2f1 3196 }
12bd6ede
DM
3197 PL_parser->in_my = FALSE;
3198 PL_parser->in_my_stash = NULL;
eb64745e 3199 return o;
09bef843
SB
3200}
3201
3202OP *
864dbfa3 3203Perl_sawparens(pTHX_ OP *o)
79072805 3204{
96a5add6 3205 PERL_UNUSED_CONTEXT;
79072805
LW
3206 if (o)
3207 o->op_flags |= OPf_PARENS;
3208 return o;
3209}
3210
3211OP *
864dbfa3 3212Perl_bind_match(pTHX_ I32 type, OP *left, OP *right)
79072805 3213{
11343788 3214 OP *o;
59f00321 3215 bool ismatchop = 0;
1496a290
AL
3216 const OPCODE ltype = left->op_type;
3217 const OPCODE rtype = right->op_type;
79072805 3218
7918f24d
NC
3219 PERL_ARGS_ASSERT_BIND_MATCH;
3220
1496a290
AL
3221 if ( (ltype == OP_RV2AV || ltype == OP_RV2HV || ltype == OP_PADAV
3222 || ltype == OP_PADHV) && ckWARN(WARN_MISC))
041457d9 3223 {
1496a290 3224 const char * const desc
bb16bae8
FC
3225 = PL_op_desc[(
3226 rtype == OP_SUBST || rtype == OP_TRANS
3227 || rtype == OP_TRANSR
3228 )
666ea192 3229 ? (int)rtype : OP_MATCH];
c6771ab6 3230 const bool isary = ltype == OP_RV2AV || ltype == OP_PADAV;
c6771ab6 3231 SV * const name =
0920b7fa 3232 S_op_varname(aTHX_ left);
c6771ab6
FC
3233 if (name)
3234 Perl_warner(aTHX_ packWARN(WARN_MISC),
3235 "Applying %s to %"SVf" will act on scalar(%"SVf")",
c1f6cd39 3236 desc, SVfARG(name), SVfARG(name));
c6771ab6
FC
3237 else {
3238 const char * const sample = (isary
666ea192 3239 ? "@array" : "%hash");
c6771ab6 3240 Perl_warner(aTHX_ packWARN(WARN_MISC),
1c846c1f 3241 "Applying %s to %s will act on scalar(%s)",
599cee73 3242 desc, sample, sample);
c6771ab6 3243 }
2ae324a7
PP
3244 }
3245
1496a290 3246 if (rtype == OP_CONST &&
5cc9e5c9
RH
3247 cSVOPx(right)->op_private & OPpCONST_BARE &&
3248 cSVOPx(right)->op_private & OPpCONST_STRICT)
3249 {
3250 no_bareword_allowed(right);
3251 }
3252
bb16bae8 3253 /* !~ doesn't make sense with /r, so error on it for now */
4f4d7508
DC
3254 if (rtype == OP_SUBST && (cPMOPx(right)->op_pmflags & PMf_NONDESTRUCT) &&
3255 type == OP_NOT)
ce0e31fe 3256 /* diag_listed_as: Using !~ with %s doesn't make sense */
4f4d7508 3257 yyerror("Using !~ with s///r doesn't make sense");
bb16bae8 3258 if (rtype == OP_TRANSR && type == OP_NOT)
ce0e31fe 3259 /* diag_listed_as: Using !~ with %s doesn't make sense */
bb16bae8 3260 yyerror("Using !~ with tr///r doesn't make sense");
4f4d7508 3261
2474a784
FC
3262 ismatchop = (rtype == OP_MATCH ||
3263 rtype == OP_SUBST ||
bb16bae8 3264 rtype == OP_TRANS || rtype == OP_TRANSR)
2474a784 3265 && !(right->op_flags & OPf_SPECIAL);
59f00321
RGS
3266 if (ismatchop && right->op_private & OPpTARGET_MY) {
3267 right->op_targ = 0;
3268 right->op_private &= ~OPpTARGET_MY;
3269 }
3270 if (!(right->op_flags & OPf_STACKED) && ismatchop) {
1496a290
AL
3271 OP *newleft;
3272
79072805 3273 right->op_flags |= OPf_STACKED;
bb16bae8 3274 if (rtype != OP_MATCH && rtype != OP_TRANSR &&
1496a290 3275 ! (rtype == OP_TRANS &&
4f4d7508
DC
3276 right->op_private & OPpTRANS_IDENTICAL) &&
3277 ! (rtype == OP_SUBST &&
3278 (cPMOPx(right)->op_pmflags & PMf_NONDESTRUCT)))
3ad73efd 3279 newleft = op_lvalue(left, rtype);
1496a290
AL
3280 else
3281 newleft = left;
bb16bae8 3282 if (right->op_type == OP_TRANS || right->op_type == OP_TRANSR)
1496a290 3283 o = newBINOP(OP_NULL, OPf_STACKED, scalar(newleft), right);
79072805 3284 else
2fcb4757 3285 o = op_prepend_elem(rtype, scalar(newleft), right);
79072805 3286 if (type == OP_NOT)
11343788
MB
3287 return newUNOP(OP_NOT, 0, scalar(o));
3288 return o;
79072805
LW
3289 }
3290 else
3291 return bind_match(type, left,
d63c20f2 3292 pmruntime(newPMOP(OP_MATCH, 0), right, 0, 0));
79072805
LW
3293}
3294
3295OP *
864dbfa3 3296Perl_invert(pTHX_ OP *o)
79072805 3297{
11343788 3298 if (!o)
1d866c12 3299 return NULL;
11343788 3300 return newUNOP(OP_NOT, OPf_SPECIAL, scalar(o));
79072805
LW
3301}
3302
3ad73efd
Z
3303/*
3304=for apidoc Amx|OP *|op_scope|OP *o
3305
3306Wraps up an op tree with some additional ops so that at runtime a dynamic
3307scope will be created. The original ops run in the new dynamic scope,
3308and then, provided that they exit normally, the scope will be unwound.
3309The additional ops used to create and unwind the dynamic scope will
3310normally be an C<enter>/C<leave> pair, but a C<scope> op may be used
3311instead if the ops are simple enough to not need the full dynamic scope
3312structure.
3313
3314=cut
3315*/
3316
79072805 3317OP *
3ad73efd 3318Perl_op_scope(pTHX_ OP *o)
79072805 3319{
27da23d5 3320 dVAR;
79072805 3321 if (o) {
284167a5 3322 if (o->op_flags & OPf_PARENS || PERLDB_NOOPT || TAINTING_get) {
2fcb4757 3323 o = op_prepend_elem(OP_LINESEQ, newOP(OP_ENTER, 0), o);
463ee0b2 3324 o->op_type = OP_LEAVE;
22c35a8c 3325 o->op_ppaddr = PL_ppaddr[OP_LEAVE];
463ee0b2 3326 }
fdb22418
HS
3327 else if (o->op_type == OP_LINESEQ) {
3328 OP *kid;
3329 o->op_type = OP_SCOPE;
3330 o->op_ppaddr = PL_ppaddr[OP_SCOPE];
3331 kid = ((LISTOP*)o)->op_first;
59110972 3332 if (kid->op_type == OP_NEXTSTATE || kid->op_type == OP_DBSTATE) {
fdb22418 3333 op_null(kid);
59110972
RH
3334
3335 /* The following deals with things like 'do {1 for 1}' */
1ed44841 3336 kid = OP_SIBLING(kid);
59110972
RH
3337 if (kid &&
3338 (kid->op_type == OP_NEXTSTATE || kid->op_type == OP_DBSTATE))
3339 op_null(kid);
3340 }
463ee0b2 3341 }
fdb22418 3342 else
5f66b61c 3343 o = newLISTOP(OP_SCOPE, 0, o, NULL);
79072805
LW
3344 }
3345 return o;
3346}
1930840b 3347
705fe0e5
FC
3348OP *
3349Perl_op_unscope(pTHX_ OP *o)
3350{
3351 if (o && o->op_type == OP_LINESEQ) {
3352 OP *kid = cLISTOPo->op_first;
1ed44841 3353 for(; kid; kid = OP_SIBLING(kid))
705fe0e5
FC
3354 if (kid->op_type == OP_NEXTSTATE || kid->op_type == OP_DBSTATE)
3355 op_null(kid);
3356 }
3357 return o;
3358}
3359
a0d0e21e 3360int
864dbfa3 3361Perl_block_start(pTHX_ int full)
79072805 3362{
73d840c0 3363 const int retval = PL_savestack_ix;
1930840b 3364
dd2155a4 3365 pad_block_start(full);
b3ac6de7 3366 SAVEHINTS();
3280af22 3367 PL_hints &= ~HINT_BLOCK_SCOPE;
68da3b2f 3368 SAVECOMPILEWARNINGS();
72dc9ed5 3369 PL_compiling.cop_warnings = DUP_WARNINGS(PL_compiling.cop_warnings);
1930840b 3370
a88d97bf 3371 CALL_BLOCK_HOOKS(bhk_start, full);
1930840b 3372
a0d0e21e
LW
3373 return retval;
3374}
3375
3376OP*
864dbfa3 3377Perl_block_end(pTHX_ I32 floor, OP *seq)
a0d0e21e 3378{
6867be6d 3379 const int needblockscope = PL_hints & HINT_BLOCK_SCOPE;
1930840b 3380 OP* retval = scalarseq(seq);
6d5c2147 3381 OP *o;
1930840b 3382
a88d97bf 3383 CALL_BLOCK_HOOKS(bhk_pre_end, &retval);
1930840b 3384
e9818f4e 3385 LEAVE_SCOPE(floor);
a0d0e21e 3386 if (needblockscope)
3280af22 3387 PL_hints |= HINT_BLOCK_SCOPE; /* propagate out */
6d5c2147
FC
3388 o = pad_leavemy();
3389
3390 if (o) {
3391 /* pad_leavemy has created a sequence of introcv ops for all my
3392 subs declared in the block. We have to replicate that list with
3393 clonecv ops, to deal with this situation:
3394
3395 sub {
3396 my sub s1;
3397 my sub s2;
3398 sub s1 { state sub foo { \&s2 } }
3399 }->()
3400
3401 Originally, I was going to have introcv clone the CV and turn
3402 off the stale flag. Since &s1 is declared before &s2, the
3403 introcv op for &s1 is executed (on sub entry) before the one for
3404 &s2. But the &foo sub inside &s1 (which is cloned when &s1 is
3405 cloned, since it is a state sub) closes over &s2 and expects
3406 to see it in its outer CV’s pad. If the introcv op clones &s1,
3407 then &s2 is still marked stale. Since &s1 is not active, and
3408 &foo closes over &s1’s implicit entry for &s2, we get a ‘Varia-
3409 ble will not stay shared’ warning. Because it is the same stub
3410 that will be used when the introcv op for &s2 is executed, clos-
3411 ing over it is safe. Hence, we have to turn off the stale flag
3412 on all lexical subs in the block before we clone any of them.
3413 Hence, having introcv clone the sub cannot work. So we create a
3414 list of ops like this:
3415
3416 lineseq
3417 |
3418 +-- introcv
3419 |
3420 +-- introcv
3421 |
3422 +-- introcv
3423 |
3424 .
3425 .
3426 .
3427 |
3428 +-- clonecv
3429 |
3430 +-- clonecv
3431 |
3432 +-- clonecv
3433 |
3434 .
3435 .
3436 .
3437 */
3438 OP *kid = o->op_flags & OPf_KIDS ? cLISTOPo->op_first : o;
3439 OP * const last = o->op_flags & OPf_KIDS ? cLISTOPo->op_last : o;
1ed44841 3440 for (;; kid = OP_SIBLING(kid)) {
6d5c2147
FC
3441 OP *newkid = newOP(OP_CLONECV, 0);
3442 newkid->op_targ = kid->op_targ;
3443 o = op_append_elem(OP_LINESEQ, o, newkid);
3444 if (kid == last) break;
3445 }
3446 retval = op_prepend_elem(OP_LINESEQ, o, retval);
3447 }
1930840b 3448
a88d97bf 3449 CALL_BLOCK_HOOKS(bhk_post_end, &retval);
1930840b 3450
a0d0e21e
LW
3451 return retval;
3452}
3453
fd85fad2
BM
3454/*
3455=head1 Compile-time scope hooks
3456
3e4ddde5 3457=for apidoc Aox||blockhook_register
fd85fad2
BM
3458
3459Register a set of hooks to be called when the Perl lexical scope changes
72d33970 3460at compile time. See L<perlguts/"Compile-time scope hooks">.
fd85fad2
BM
3461
3462=cut
3463*/
3464
bb6c22e7
BM
3465void
3466Perl_blockhook_register(pTHX_ BHK *hk)
3467{
3468 PERL_ARGS_ASSERT_BLOCKHOOK_REGISTER;
3469
3470 Perl_av_create_and_push(aTHX_ &PL_blockhooks, newSViv(PTR2IV(hk)));
3471}
3472
76e3520e 3473STATIC OP *
cea2e8a9 3474S_newDEFSVOP(pTHX)
54b9620d 3475{
cc76b5cc 3476 const PADOFFSET offset = pad_findmy_pvs("$_", 0);
00b1698f 3477 if (offset == NOT_IN_PAD || PAD_COMPNAME_FLAGS_isOUR(offset)) {
59f00321
RGS
3478 return newSVREF(newGVOP(OP_GV, 0, PL_defgv));
3479 }
3480 else {
551405c4 3481 OP * const o = newOP(OP_PADSV, 0);
59f00321
RGS
3482 o->op_targ = offset;
3483 return o;
3484 }
54b9620d
MB
3485}
3486
a0d0e21e 3487void
864dbfa3 3488Perl_newPROG(pTHX_ OP *o)
a0d0e21e 3489{
7918f24d
NC
3490 PERL_ARGS_ASSERT_NEWPROG;
3491
3280af22 3492 if (PL_in_eval) {
86a64801 3493 PERL_CONTEXT *cx;
63429d50 3494 I32 i;
b295d113
TH
3495 if (PL_eval_root)
3496 return;
faef0170
HS
3497 PL_eval_root = newUNOP(OP_LEAVEEVAL,
3498 ((PL_in_eval & EVAL_KEEPERR)
3499 ? OPf_SPECIAL : 0), o);
86a64801
GG
3500
3501 cx = &cxstack[cxstack_ix];
3502 assert(CxTYPE(cx) == CXt_EVAL);
3503
3504 if ((cx->blk_gimme & G_WANT) == G_VOID)
3505 scalarvoid(PL_eval_root);
3506 else if ((cx->blk_gimme & G_WANT) == G_ARRAY)
3507 list(PL_eval_root);
3508 else
3509 scalar(PL_eval_root);
3510
5983a79d 3511 PL_eval_start = op_linklist(PL_eval_root);
7934575e
GS
3512 PL_eval_root->op_private |= OPpREFCOUNTED;
3513 OpREFCNT_set(PL_eval_root, 1);
3280af22 3514 PL_eval_root->op_next = 0;
63429d50
FC
3515 i = PL_savestack_ix;
3516 SAVEFREEOP(o);
3517 ENTER;
a2efc822 3518 CALL_PEEP(PL_eval_start);
86a64801 3519 finalize_optree(PL_eval_root);
dc3bf405 3520 S_prune_chain_head(&PL_eval_start);
63429d50
FC
3521 LEAVE;
3522 PL_savestack_ix = i;
a0d0e21e
LW
3523 }
3524 else {
6be89cf9 3525 if (o->op_type == OP_STUB) {
22e660b4
NC
3526 /* This block is entered if nothing is compiled for the main
3527 program. This will be the case for an genuinely empty main
3528 program, or one which only has BEGIN blocks etc, so already
3529 run and freed.
3530
3531 Historically (5.000) the guard above was !o. However, commit
3532 f8a08f7b8bd67b28 (Jun 2001), integrated to blead as
3533 c71fccf11fde0068, changed perly.y so that newPROG() is now
3534 called with the output of block_end(), which returns a new
3535 OP_STUB for the case of an empty optree. ByteLoader (and
3536 maybe other things) also take this path, because they set up
3537 PL_main_start and PL_main_root directly, without generating an
3538 optree.
8b31d4e4
NC
3539
3540 If the parsing the main program aborts (due to parse errors,
3541 or due to BEGIN or similar calling exit), then newPROG()
3542 isn't even called, and hence this code path and its cleanups
3543 are skipped. This shouldn't make a make a difference:
3544 * a non-zero return from perl_parse is a failure, and
3545 perl_destruct() should be called immediately.
3546 * however, if exit(0) is called during the parse, then
3547 perl_parse() returns 0, and perl_run() is called. As
3548 PL_main_start will be NULL, perl_run() will return
3549 promptly, and the exit code will remain 0.
22e660b4
NC
3550 */
3551
6be89cf9
AE
3552 PL_comppad_name = 0;
3553 PL_compcv = 0;
d2c837a0 3554 S_op_destroy(aTHX_ o);
a0d0e21e 3555 return;
6be89cf9 3556 }
3ad73efd 3557 PL_main_root = op_scope(sawparens(scalarvoid(o)));
3280af22
NIS
3558 PL_curcop = &PL_compiling;
3559 PL_main_start = LINKLIST(PL_main_root);
7934575e
GS
3560 PL_main_root->op_private |= OPpREFCOUNTED;
3561 OpREFCNT_set(PL_main_root, 1);
3280af22 3562 PL_main_root->op_next = 0;
a2efc822 3563 CALL_PEEP(PL_main_start);
d164302a 3564 finalize_optree(PL_main_root);
dc3bf405 3565 S_prune_chain_head(&PL_main_start);
8be227ab 3566 cv_forget_slab(PL_compcv);
3280af22 3567 PL_compcv = 0;
3841441e 3568
4fdae800 3569 /* Register with debugger */
84902520 3570 if (PERLDB_INTER) {
b96d8cd9 3571 CV * const cv = get_cvs("DB::postponed", 0);
3841441e
CS
3572 if (cv) {
3573 dSP;
924508f0 3574 PUSHMARK(SP);
ad64d0ec 3575 XPUSHs(MUTABLE_SV(CopFILEGV(&PL_compiling)));
3841441e 3576 PUTBACK;
ad64d0ec 3577 call_sv(MUTABLE_SV(cv), G_DISCARD);
3841441e
CS
3578 }
3579 }
79072805 3580 }
79072805
LW
3581}
3582
3583OP *
864dbfa3 3584Perl_localize(pTHX_ OP *o, I32 lex)
79072805 3585{
7918f24d
NC
3586 PERL_ARGS_ASSERT_LOCALIZE;
3587
79072805 3588 if (o->op_flags & OPf_PARENS)
d2be0de5
YST
3589/* [perl #17376]: this appears to be premature, and results in code such as
3590 C< our(%x); > executing in list mode rather than void mode */
3591#if 0
79072805 3592 list(o);
d2be0de5 3593#else
6f207bd3 3594 NOOP;
d2be0de5 3595#endif
8990e307 3596 else {
f06b5848
DM
3597 if ( PL_parser->bufptr > PL_parser->oldbufptr
3598 && PL_parser->bufptr[-1] == ','
041457d9 3599 && ckWARN(WARN_PARENTHESIS))
64420d0d 3600 {
f06b5848 3601 char *s = PL_parser->bufptr;
bac662ee 3602 bool sigil = FALSE;
64420d0d 3603
8473848f 3604 /* some heuristics to detect a potential error */
bac662ee 3605 while (*s && (strchr(", \t\n", *s)))
64420d0d 3606 s++;
8473848f 3607
bac662ee
ST
3608 while (1) {
3609 if (*s && strchr("@$%*", *s) && *++s
0eb30aeb 3610 && (isWORDCHAR(*s) || UTF8_IS_CONTINUED(*s))) {
bac662ee
ST
3611 s++;
3612 sigil = TRUE;
0eb30aeb 3613 while (*s && (isWORDCHAR(*s) || UTF8_IS_CONTINUED(*s)))
bac662ee
ST
3614 s++;
3615 while (*s && (strchr(", \t\n", *s)))
3616 s++;
3617 }
3618 else
3619 break;
3620 }
3621 if (sigil && (*s == ';' || *s == '=')) {
3622 Perl_warner(aTHX_ packWARN(WARN_PARENTHESIS),
8473848f 3623 "Parentheses missing around \"%s\" list",
12bd6ede
DM
3624 lex
3625 ? (PL_parser->in_my == KEY_our
3626 ? "our"
3627 : PL_parser->in_my == KEY_state
3628 ? "state"
3629 : "my")
3630 : "local");
8473848f 3631 }
8990e307
LW
3632 }
3633 }
93a17b20