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Fix some pedantic pod erros in Thread::Queue
[perl5.git] / op.c
CommitLineData
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
aa9d1253
TC		 112/* Used to avoid recursion through the op tree in scalarvoid() and
113 op_free()
114*/
115
116#define DEFERRED_OP_STEP 100
117#define DEFER_OP(o) \
118 STMT_START { \
119 if (UNLIKELY(defer_ix == (defer_stack_alloc-1))) { \
120 defer_stack_alloc += DEFERRED_OP_STEP; \
121 assert(defer_stack_alloc > 0); \
122 Renew(defer_stack, defer_stack_alloc, OP *); \
123 } \
124 defer_stack[++defer_ix] = o; \
125 } STMT_END
126
127#define POP_DEFERRED_OP() (defer_ix >= 0 ? defer_stack[defer_ix--] : (OP *)NULL)
128
72621f84
DM		 129/* remove any leading "empty" ops from the op_next chain whose first
130 * node's address is stored in op_p. Store the updated address of the
131 * first node in op_p.
132 */
133
134STATIC void
dc3bf405 135S_prune_chain_head(OP** op_p)
72621f84
DM		 136{
137 while (*op_p
138 && ( (*op_p)->op_type == OP_NULL
139 || (*op_p)->op_type == OP_SCOPE
140 || (*op_p)->op_type == OP_SCALAR
141 || (*op_p)->op_type == OP_LINESEQ)
142 )
143 *op_p = (*op_p)->op_next;
144}
145
146
8be227ab
FC		 147/* See the explanatory comments above struct opslab in op.h. */
148
7aef8e5b 149#ifdef PERL_DEBUG_READONLY_OPS
3107b51f
FC		 150# define PERL_SLAB_SIZE 128
151# define PERL_MAX_SLAB_SIZE 4096
152# include <sys/mman.h>
7aef8e5b 153#endif
3107b51f 154
7aef8e5b 155#ifndef PERL_SLAB_SIZE
8be227ab 156# define PERL_SLAB_SIZE 64
7aef8e5b
FC		 157#endif
158#ifndef PERL_MAX_SLAB_SIZE
e6cee8c0 159# define PERL_MAX_SLAB_SIZE 2048
7aef8e5b 160#endif
8be227ab
FC		 161
162/* rounds up to nearest pointer */
7aef8e5b
FC		 163#define SIZE_TO_PSIZE(x) (((x) + sizeof(I32 *) - 1)/sizeof(I32 *))
164#define DIFF(o,p) ((size_t)((I32 **)(p) - (I32**)(o)))
8be227ab
FC		 165
166static OPSLAB *
167S_new_slab(pTHX_ size_t sz)
168{
7aef8e5b 169#ifdef PERL_DEBUG_READONLY_OPS
3107b51f
FC		 170 OPSLAB *slab = (OPSLAB *) mmap(0, sz * sizeof(I32 *),
171 PROT_READ|PROT_WRITE,
172 MAP_ANON|MAP_PRIVATE, -1, 0);
173 DEBUG_m(PerlIO_printf(Perl_debug_log, "mapped %lu at %p\n",
174 (unsigned long) sz, slab));
175 if (slab == MAP_FAILED) {
176 perror("mmap failed");
177 abort();
178 }
179 slab->opslab_size = (U16)sz;
7aef8e5b 180#else
8be227ab 181 OPSLAB *slab = (OPSLAB *)PerlMemShared_calloc(sz, sizeof(I32 *));
7aef8e5b 182#endif
dc3bf405
BF		 183#ifndef WIN32
184 /* The context is unused in non-Windows */
185 PERL_UNUSED_CONTEXT;
186#endif
8be227ab
FC		 187 slab->opslab_first = (OPSLOT *)((I32 **)slab + sz - 1);
188 return slab;
189}
190
e7372881
FC		 191/* requires double parens and aTHX_ */
192#define DEBUG_S_warn(args) \
193 DEBUG_S( \
194 PerlIO_printf(Perl_debug_log, "%s", SvPVx_nolen(Perl_mess args)) \
195 )
196
8be227ab
FC		 197void *
198Perl_Slab_Alloc(pTHX_ size_t sz)
199{
8be227ab
FC		 200 OPSLAB *slab;
201 OPSLAB *slab2;
202 OPSLOT *slot;
203 OP *o;
5cb52f30 204 size_t opsz, space;
8be227ab 205
2073970f
NC		 206 /* We only allocate ops from the slab during subroutine compilation.
207 We find the slab via PL_compcv, hence that must be non-NULL. It could
208 also be pointing to a subroutine which is now fully set up (CvROOT()
209 pointing to the top of the optree for that sub), or a subroutine
210 which isn't using the slab allocator. If our sanity checks aren't met,
211 don't use a slab, but allocate the OP directly from the heap. */
8be227ab
FC		 212 if (!PL_compcv || CvROOT(PL_compcv)
213 || (CvSTART(PL_compcv) && !CvSLABBED(PL_compcv)))
29e61fd9
DM		 214 {
215 o = (OP*)PerlMemShared_calloc(1, sz);
216 goto gotit;
217 }
8be227ab 218
2073970f
NC		 219 /* While the subroutine is under construction, the slabs are accessed via
220 CvSTART(), to avoid needing to expand PVCV by one pointer for something
221 unneeded at runtime. Once a subroutine is constructed, the slabs are
222 accessed via CvROOT(). So if CvSTART() is NULL, no slab has been
223 allocated yet. See the commit message for 8be227ab5eaa23f2 for more
224 details. */
225 if (!CvSTART(PL_compcv)) {
8be227ab
FC		 226 CvSTART(PL_compcv) =
227 (OP *)(slab = S_new_slab(aTHX_ PERL_SLAB_SIZE));
228 CvSLABBED_on(PL_compcv);
229 slab->opslab_refcnt = 2; /* one for the CV; one for the new OP */
230 }
231 else ++(slab = (OPSLAB *)CvSTART(PL_compcv))->opslab_refcnt;
232
5cb52f30
FC		 233 opsz = SIZE_TO_PSIZE(sz);
234 sz = opsz + OPSLOT_HEADER_P;
8be227ab 235
2073970f
NC		 236 /* The slabs maintain a free list of OPs. In particular, constant folding
237 will free up OPs, so it makes sense to re-use them where possible. A
238 freed up slot is used in preference to a new allocation. */
8be227ab
FC		 239 if (slab->opslab_freed) {
240 OP **too = &slab->opslab_freed;
241 o = *too;
eb212a1c 242 DEBUG_S_warn((aTHX_ "found free op at %p, slab %p", (void*)o, (void*)slab));
8be227ab 243 while (o && DIFF(OpSLOT(o), OpSLOT(o)->opslot_next) < sz) {
e7372881 244 DEBUG_S_warn((aTHX_ "Alas! too small"));
8be227ab 245 o = *(too = &o->op_next);
eb212a1c 246 if (o) { DEBUG_S_warn((aTHX_ "found another free op at %p", (void*)o)); }
8be227ab
FC		 247 }
248 if (o) {
249 *too = o->op_next;
5cb52f30 250 Zero(o, opsz, I32 *);
8be227ab 251 o->op_slabbed = 1;
29e61fd9 252 goto gotit;
8be227ab
FC		 253 }
254 }
255
7aef8e5b 256#define INIT_OPSLOT \
8be227ab
FC		 257 slot->opslot_slab = slab; \
258 slot->opslot_next = slab2->opslab_first; \
259 slab2->opslab_first = slot; \
260 o = &slot->opslot_op; \
261 o->op_slabbed = 1
262
263 /* The partially-filled slab is next in the chain. */
264 slab2 = slab->opslab_next ? slab->opslab_next : slab;
265 if ((space = DIFF(&slab2->opslab_slots, slab2->opslab_first)) < sz) {
266 /* Remaining space is too small. */
267
8be227ab
FC		 268 /* If we can fit a BASEOP, add it to the free chain, so as not
269 to waste it. */
270 if (space >= SIZE_TO_PSIZE(sizeof(OP)) + OPSLOT_HEADER_P) {
271 slot = &slab2->opslab_slots;
272 INIT_OPSLOT;
273 o->op_type = OP_FREED;
274 o->op_next = slab->opslab_freed;
275 slab->opslab_freed = o;
276 }
277
278 /* Create a new slab. Make this one twice as big. */
279 slot = slab2->opslab_first;
280 while (slot->opslot_next) slot = slot->opslot_next;
af7751f6
FC		 281 slab2 = S_new_slab(aTHX_
282 (DIFF(slab2, slot)+1)*2 > PERL_MAX_SLAB_SIZE
e6cee8c0 283 ? PERL_MAX_SLAB_SIZE
af7751f6 284 : (DIFF(slab2, slot)+1)*2);
9963ffa2
FC		 285 slab2->opslab_next = slab->opslab_next;
286 slab->opslab_next = slab2;
8be227ab
FC		 287 }
288 assert(DIFF(&slab2->opslab_slots, slab2->opslab_first) >= sz);
289
290 /* Create a new op slot */
291 slot = (OPSLOT *)((I32 **)slab2->opslab_first - sz);
292 assert(slot >= &slab2->opslab_slots);
51c777ca
FC		 293 if (DIFF(&slab2->opslab_slots, slot)
294 < SIZE_TO_PSIZE(sizeof(OP)) + OPSLOT_HEADER_P)
295 slot = &slab2->opslab_slots;
8be227ab 296 INIT_OPSLOT;
eb212a1c 297 DEBUG_S_warn((aTHX_ "allocating op at %p, slab %p", (void*)o, (void*)slab));
29e61fd9
DM		 298
299 gotit:
93059c1a 300#ifdef PERL_OP_PARENT
87b5a8b9
DM		 301 /* moresib == 0, op_sibling == 0 implies a solitary unattached op */
302 assert(!o->op_moresib);
86cd3a13 303 assert(!o->op_sibparent);
93059c1a 304#endif
29e61fd9 305
8be227ab
FC		 306 return (void *)o;
307}
308
7aef8e5b 309#undef INIT_OPSLOT
8be227ab 310
7aef8e5b 311#ifdef PERL_DEBUG_READONLY_OPS
3107b51f
FC		 312void
313Perl_Slab_to_ro(pTHX_ OPSLAB *slab)
314{
315 PERL_ARGS_ASSERT_SLAB_TO_RO;
316
317 if (slab->opslab_readonly) return;
318 slab->opslab_readonly = 1;
319 for (; slab; slab = slab->opslab_next) {
320 /*DEBUG_U(PerlIO_printf(Perl_debug_log,"mprotect ->ro %lu at %p\n",
321 (unsigned long) slab->opslab_size, slab));*/
322 if (mprotect(slab, slab->opslab_size * sizeof(I32 *), PROT_READ))
323 Perl_warn(aTHX_ "mprotect for %p %lu failed with %d", slab,
324 (unsigned long)slab->opslab_size, errno);
325 }
326}
327
7bbbc3c0
NC		 328void
329Perl_Slab_to_rw(pTHX_ OPSLAB *const slab)
3107b51f 330{
3107b51f
FC		 331 OPSLAB *slab2;
332
333 PERL_ARGS_ASSERT_SLAB_TO_RW;
334
3107b51f
FC		 335 if (!slab->opslab_readonly) return;
336 slab2 = slab;
337 for (; slab2; slab2 = slab2->opslab_next) {
338 /*DEBUG_U(PerlIO_printf(Perl_debug_log,"mprotect ->rw %lu at %p\n",
339 (unsigned long) size, slab2));*/
340 if (mprotect((void *)slab2, slab2->opslab_size * sizeof(I32 *),
341 PROT_READ|PROT_WRITE)) {
342 Perl_warn(aTHX_ "mprotect RW for %p %lu failed with %d", slab,
343 (unsigned long)slab2->opslab_size, errno);
344 }
345 }
346 slab->opslab_readonly = 0;
347}
348
349#else
9e4d7a13 350# define Slab_to_rw(op) NOOP
3107b51f
FC		 351#endif
352
8be227ab
FC		 353/* This cannot possibly be right, but it was copied from the old slab
354 allocator, to which it was originally added, without explanation, in
355 commit 083fcd5. */
7aef8e5b 356#ifdef NETWARE
8be227ab 357# define PerlMemShared PerlMem
7aef8e5b 358#endif
8be227ab
FC		 359
360void
361Perl_Slab_Free(pTHX_ void *op)
362{
363 OP * const o = (OP *)op;
364 OPSLAB *slab;
365
366 PERL_ARGS_ASSERT_SLAB_FREE;
367
368 if (!o->op_slabbed) {
90840c5d
RU		 369 if (!o->op_static)
370 PerlMemShared_free(op);
8be227ab
FC		 371 return;
372 }
373
374 slab = OpSLAB(o);
375 /* If this op is already freed, our refcount will get screwy. */
376 assert(o->op_type != OP_FREED);
377 o->op_type = OP_FREED;
378 o->op_next = slab->opslab_freed;
379 slab->opslab_freed = o;
eb212a1c 380 DEBUG_S_warn((aTHX_ "free op at %p, recorded in slab %p", (void*)o, (void*)slab));
8be227ab
FC		 381 OpslabREFCNT_dec_padok(slab);
382}
383
384void
385Perl_opslab_free_nopad(pTHX_ OPSLAB *slab)
386{
8be227ab
FC		 387 const bool havepad = !!PL_comppad;
388 PERL_ARGS_ASSERT_OPSLAB_FREE_NOPAD;
389 if (havepad) {
390 ENTER;
391 PAD_SAVE_SETNULLPAD();
392 }
393 opslab_free(slab);
394 if (havepad) LEAVE;
395}
396
397void
398Perl_opslab_free(pTHX_ OPSLAB *slab)
399{
400 OPSLAB *slab2;
401 PERL_ARGS_ASSERT_OPSLAB_FREE;
81611534 402 PERL_UNUSED_CONTEXT;
eb212a1c 403 DEBUG_S_warn((aTHX_ "freeing slab %p", (void*)slab));
8be227ab 404 assert(slab->opslab_refcnt == 1);
3dc78631 405 do {
8be227ab 406 slab2 = slab->opslab_next;
7aef8e5b 407#ifdef DEBUGGING
8be227ab 408 slab->opslab_refcnt = ~(size_t)0;
7aef8e5b
FC		 409#endif
410#ifdef PERL_DEBUG_READONLY_OPS
3107b51f 411 DEBUG_m(PerlIO_printf(Perl_debug_log, "Deallocate slab at %p\n",
eb212a1c 412 (void*)slab));
3107b51f
FC		 413 if (munmap(slab, slab->opslab_size * sizeof(I32 *))) {
414 perror("munmap failed");
415 abort();
416 }
7aef8e5b 417#else
8be227ab 418 PerlMemShared_free(slab);
7aef8e5b 419#endif
3dc78631
DM		 420 slab = slab2;
421 } while (slab);
8be227ab
FC		 422}
423
424void
425Perl_opslab_force_free(pTHX_ OPSLAB *slab)
426{
427 OPSLAB *slab2;
428 OPSLOT *slot;
7aef8e5b 429#ifdef DEBUGGING
8be227ab 430 size_t savestack_count = 0;
7aef8e5b 431#endif
8be227ab
FC		 432 PERL_ARGS_ASSERT_OPSLAB_FORCE_FREE;
433 slab2 = slab;
434 do {
435 for (slot = slab2->opslab_first;
436 slot->opslot_next;
437 slot = slot->opslot_next) {
438 if (slot->opslot_op.op_type != OP_FREED
439 && !(slot->opslot_op.op_savefree
7aef8e5b 440#ifdef DEBUGGING
8be227ab 441 && ++savestack_count
7aef8e5b 442#endif
8be227ab
FC		 443 )
444 ) {
445 assert(slot->opslot_op.op_slabbed);
8be227ab 446 op_free(&slot->opslot_op);
3bf28c7e 447 if (slab->opslab_refcnt == 1) goto free;
8be227ab
FC		 448 }
449 }
450 } while ((slab2 = slab2->opslab_next));
451 /* > 1 because the CV still holds a reference count. */
452 if (slab->opslab_refcnt > 1) { /* still referenced by the savestack */
7aef8e5b 453#ifdef DEBUGGING
8be227ab 454 assert(savestack_count == slab->opslab_refcnt-1);
7aef8e5b 455#endif
ee5ee853
FC		 456 /* Remove the CV’s reference count. */
457 slab->opslab_refcnt--;
8be227ab
FC		 458 return;
459 }
460 free:
461 opslab_free(slab);
462}
463
3107b51f
FC		 464#ifdef PERL_DEBUG_READONLY_OPS
465OP *
466Perl_op_refcnt_inc(pTHX_ OP *o)
467{
468 if(o) {
372eab01
NC		 469 OPSLAB *const slab = o->op_slabbed ? OpSLAB(o) : NULL;
470 if (slab && slab->opslab_readonly) {
83519873 471 Slab_to_rw(slab);
372eab01
NC		 472 ++o->op_targ;
473 Slab_to_ro(slab);
474 } else {
475 ++o->op_targ;
476 }
3107b51f
FC		 477 }
478 return o;
479
480}
481
482PADOFFSET
483Perl_op_refcnt_dec(pTHX_ OP *o)
484{
372eab01
NC		 485 PADOFFSET result;
486 OPSLAB *const slab = o->op_slabbed ? OpSLAB(o) : NULL;
487
3107b51f 488 PERL_ARGS_ASSERT_OP_REFCNT_DEC;
372eab01
NC		 489
490 if (slab && slab->opslab_readonly) {
83519873 491 Slab_to_rw(slab);
372eab01
NC		 492 result = --o->op_targ;
493 Slab_to_ro(slab);
494 } else {
495 result = --o->op_targ;
496 }
497 return result;
3107b51f
FC		 498}
499#endif
e50aee73 500/*
ce6f1cbc 501 * In the following definition, the ", (OP*)0" is just to make the compiler
a5f75d66 502 * think the expression is of the right type: croak actually does a Siglongjmp.
e50aee73 503 */
11343788 504#define CHECKOP(type,o) \
ce6f1cbc 505 ((PL_op_mask && PL_op_mask[type]) \
5dc0d613 506 ? ( op_free((OP*)o), \
cb77fdf0 507 Perl_croak(aTHX_ "'%s' trapped by operation mask", PL_op_desc[type]), \
ce6f1cbc 508 (OP*)0 ) \
16c91539 509 : PL_check[type](aTHX_ (OP*)o))
e50aee73 510
e6438c1a 511#define RETURN_UNLIMITED_NUMBER (PERL_INT_MAX / 2)
c53d7c7d 512
b9a07097 513#define OpTYPE_set(o,type) \
cba5a3b0
DG		 514 STMT_START { \
515 o->op_type = (OPCODE)type; \
516 o->op_ppaddr = PL_ppaddr[type]; \
517 } STMT_END
518
76e3520e 519STATIC OP *
cea2e8a9 520S_no_fh_allowed(pTHX_ OP *o)
79072805 521{
7918f24d
NC		 522 PERL_ARGS_ASSERT_NO_FH_ALLOWED;
523
cea2e8a9 524 yyerror(Perl_form(aTHX_ "Missing comma after first argument to %s function",
53e06cf0 525 OP_DESC(o)));
11343788 526 return o;
79072805
LW		 527}
528
76e3520e 529STATIC OP *
ce16c625
BF		 530S_too_few_arguments_pv(pTHX_ OP *o, const char* name, U32 flags)
531{
532 PERL_ARGS_ASSERT_TOO_FEW_ARGUMENTS_PV;
533 yyerror_pv(Perl_form(aTHX_ "Not enough arguments for %s", name), flags);
534 return o;
535}
536
537STATIC OP *
538S_too_many_arguments_pv(pTHX_ OP *o, const char *name, U32 flags)
539{
540 PERL_ARGS_ASSERT_TOO_MANY_ARGUMENTS_PV;
7918f24d 541
ce16c625 542 yyerror_pv(Perl_form(aTHX_ "Too many arguments for %s", name), flags);
11343788 543 return o;
79072805
LW		 544}
545
76e3520e 546STATIC void
ed9feedd 547S_bad_type_pv(pTHX_ I32 n, const char *t, const OP *o, const OP *kid)
8990e307 548{
ce16c625
BF		 549 PERL_ARGS_ASSERT_BAD_TYPE_PV;
550
551 yyerror_pv(Perl_form(aTHX_ "Type of arg %d to %s must be %s (not %s)",
ed9feedd 552 (int)n, PL_op_desc[(o)->op_type], t, OP_DESC(kid)), 0);
ce16c625 553}
7918f24d 554
ed9feedd
DD		 555/* remove flags var, its unused in all callers, move to to right end since gv
556 and kid are always the same */
ce16c625 557STATIC void
ed9feedd 558S_bad_type_gv(pTHX_ I32 n, GV *gv, const OP *kid, const char *t)
ce16c625 559{
ecf05a58 560 SV * const namesv = cv_name((CV *)gv, NULL, 0);
7b3b0904 561 PERL_ARGS_ASSERT_BAD_TYPE_GV;
ce16c625
BF		 562
563 yyerror_pv(Perl_form(aTHX_ "Type of arg %d to %"SVf" must be %s (not %s)",
ed9feedd 564 (int)n, SVfARG(namesv), t, OP_DESC(kid)), SvUTF8(namesv));
8990e307
LW		 565}
566
7a52d87a 567STATIC void
eb796c7f 568S_no_bareword_allowed(pTHX_ OP *o)
7a52d87a 569{
7918f24d
NC		 570 PERL_ARGS_ASSERT_NO_BAREWORD_ALLOWED;
571
5a844595 572 qerror(Perl_mess(aTHX_
35c1215d 573 "Bareword \"%"SVf"\" not allowed while \"strict subs\" in use",
be2597df 574 SVfARG(cSVOPo_sv)));
eb796c7f 575 o->op_private &= ~OPpCONST_STRICT; /* prevent warning twice about the same OP */
7a52d87a
GS		 576}
577
79072805
LW		 578/* "register" allocation */
579
580PADOFFSET
d6447115 581Perl_allocmy(pTHX_ const char *const name, const STRLEN len, const U32 flags)
93a17b20 582{
a0d0e21e 583 PADOFFSET off;
12bd6ede 584 const bool is_our = (PL_parser->in_my == KEY_our);
a0d0e21e 585
7918f24d
NC		 586 PERL_ARGS_ASSERT_ALLOCMY;
587
48d0d1be 588 if (flags & ~SVf_UTF8)
d6447115
NC		 589 Perl_croak(aTHX_ "panic: allocmy illegal flag bits 0x%" UVxf,
590 (UV)flags);
591
59f00321 592 /* complain about "my $<special_var>" etc etc */
d6447115 593 if (len &&
3edf23ff 594 !(is_our ||
155aba94 595 isALPHA(name[1]) ||
b14845b4 596 ((flags & SVf_UTF8) && isIDFIRST_utf8((U8 *)name+1)) ||
d6447115 597 (name[1] == '_' && (*name == '$' || len > 2))))
834a4ddd 598 {
b14845b4 599 if (!(flags & SVf_UTF8 && UTF8_IS_START(name[1]))
f6a1dc93 600 && isASCII(name[1])
b14845b4 601 && (!isPRINT(name[1]) || strchr("\t\n\r\f", name[1]))) {
d6447115
NC		 602 yyerror(Perl_form(aTHX_ "Can't use global %c^%c%.*s in \"%s\"",
603 name[0], toCTRL(name[1]), (int)(len - 2), name + 2,
aab6a793 604 PL_parser->in_my == KEY_state ? "state" : "my"));
d1544d85 605 } else {
ce16c625
BF		 606 yyerror_pv(Perl_form(aTHX_ "Can't use global %.*s in \"%s\"", (int) len, name,
607 PL_parser->in_my == KEY_state ? "state" : "my"), flags & SVf_UTF8);
46fc3d4c 608 }
a0d0e21e 609 }
4055dbce
RS		 610 else if (len == 2 && name[1] == '_' && !is_our)
611 /* diag_listed_as: Use of my $_ is experimental */
612 Perl_ck_warner_d(aTHX_ packWARN(WARN_EXPERIMENTAL__LEXICAL_TOPIC),
613 "Use of %s $_ is experimental",
614 PL_parser->in_my == KEY_state
615 ? "state"
616 : "my");
748a9306 617
dd2155a4 618 /* allocate a spare slot and store the name in that slot */
93a17b20 619
cc76b5cc 620 off = pad_add_name_pvn(name, len,
48d0d1be 621 (is_our ? padadd_OUR :
2502ffdf 622 PL_parser->in_my == KEY_state ? padadd_STATE : 0),
12bd6ede 623 PL_parser->in_my_stash,
3edf23ff 624 (is_our
133706a6 625 /* $_ is always in main::, even with our */
ef00320b
FC		 626 ? (PL_curstash && !memEQs(name,len,"$_")
627 ? PL_curstash
628 : PL_defstash)
5c284bb0 629 : NULL
cca43f78 630 )
dd2155a4 631 );
a74073ad
DM		 632 /* anon sub prototypes contains state vars should always be cloned,
633 * otherwise the state var would be shared between anon subs */
634
635 if (PL_parser->in_my == KEY_state && CvANON(PL_compcv))
636 CvCLONE_on(PL_compcv);
637
dd2155a4 638 return off;
79072805
LW		 639}
640
c0b8aebd 641/*
dcccc8ff
KW		 642=head1 Optree Manipulation Functions
643
c0b8aebd
FC		 644=for apidoc alloccopstash
645
646Available only under threaded builds, this function allocates an entry in
647C<PL_stashpad> for the stash passed to it.
648
649=cut
650*/
651
d4d03940
FC		 652#ifdef USE_ITHREADS
653PADOFFSET
1dc74fdb 654Perl_alloccopstash(pTHX_ HV *hv)
d4d03940
FC		 655{
656 PADOFFSET off = 0, o = 1;
657 bool found_slot = FALSE;
658
1dc74fdb
FC		 659 PERL_ARGS_ASSERT_ALLOCCOPSTASH;
660
661 if (PL_stashpad[PL_stashpadix] == hv) return PL_stashpadix;
d4d03940 662
1dc74fdb
FC		 663 for (; o < PL_stashpadmax; ++o) {
664 if (PL_stashpad[o] == hv) return PL_stashpadix = o;
665 if (!PL_stashpad[o] || SvTYPE(PL_stashpad[o]) != SVt_PVHV)
d4d03940
FC		 666 found_slot = TRUE, off = o;
667 }
668 if (!found_slot) {
1dc74fdb
FC		 669 Renew(PL_stashpad, PL_stashpadmax + 10, HV *);
670 Zero(PL_stashpad + PL_stashpadmax, 10, HV *);
671 off = PL_stashpadmax;
672 PL_stashpadmax += 10;
d4d03940
FC		 673 }
674
1dc74fdb 675 PL_stashpad[PL_stashpadix = off] = hv;
d4d03940
FC		 676 return off;
677}
678#endif
679
d2c837a0
DM		 680/* free the body of an op without examining its contents.
681 * Always use this rather than FreeOp directly */
682
4136a0f7 683static void
d2c837a0
DM		 684S_op_destroy(pTHX_ OP *o)
685{
d2c837a0
DM		 686 FreeOp(o);
687}
688
79072805
LW		 689/* Destructor */
690
6e53b6ca
DD		 691/*
692=for apidoc Am|void|op_free|OP *o
693
cc41839b
FC		 694Free an op. Only use this when an op is no longer linked to from any
695optree.
6e53b6ca
DD		 696
697=cut
698*/
699
79072805 700void
864dbfa3 701Perl_op_free(pTHX_ OP *o)
79072805 702{
27da23d5 703 dVAR;
acb36ea4 704 OPCODE type;
0997db6f
TC		 705 SSize_t defer_ix = -1;
706 SSize_t defer_stack_alloc = 0;
707 OP **defer_stack = NULL;
79072805 708
0997db6f 709 do {
79072805 710
0997db6f
TC		 711 /* Though ops may be freed twice, freeing the op after its slab is a
712 big no-no. */
713 assert(!o || !o->op_slabbed || OpSLAB(o)->opslab_refcnt != ~(size_t)0);
714 /* During the forced freeing of ops after compilation failure, kidops
715 may be freed before their parents. */
716 if (!o || o->op_type == OP_FREED)
717 continue;
d0c8136d 718
0997db6f 719 type = o->op_type;
d0c8136d 720
0997db6f
TC		 721 /* an op should only ever acquire op_private flags that we know about.
722 * If this fails, you may need to fix something in regen/op_private */
723 if (o->op_ppaddr == PL_ppaddr[o->op_type]) {
724 assert(!(o->op_private & ~PL_op_private_valid[type]));
725 }
7934575e 726
0997db6f
TC		 727 if (o->op_private & OPpREFCOUNTED) {
728 switch (type) {
729 case OP_LEAVESUB:
730 case OP_LEAVESUBLV:
731 case OP_LEAVEEVAL:
732 case OP_LEAVE:
733 case OP_SCOPE:
734 case OP_LEAVEWRITE:
735 {
736 PADOFFSET refcnt;
737 OP_REFCNT_LOCK;
738 refcnt = OpREFCNT_dec(o);
739 OP_REFCNT_UNLOCK;
740 if (refcnt) {
741 /* Need to find and remove any pattern match ops from the list
742 we maintain for reset(). */
743 find_and_forget_pmops(o);
744 continue;
745 }
746 }
747 break;
748 default:
749 break;
750 }
751 }
f37b8c3f 752
0997db6f
TC		 753 /* Call the op_free hook if it has been set. Do it now so that it's called
754 * at the right time for refcounted ops, but still before all of the kids
755 * are freed. */
756 CALL_OPFREEHOOK(o);
757
758 if (o->op_flags & OPf_KIDS) {
759 OP *kid, *nextkid;
760 for (kid = cUNOPo->op_first; kid; kid = nextkid) {
e6dae479 761 nextkid = OpSIBLING(kid); /* Get before next freeing kid */
0997db6f
TC		 762 if (!kid || kid->op_type == OP_FREED)
763 /* During the forced freeing of ops after
764 compilation failure, kidops may be freed before
765 their parents. */
766 continue;
767 if (!(kid->op_flags & OPf_KIDS))
768 /* If it has no kids, just free it now */
769 op_free(kid);
770 else
aa9d1253 771 DEFER_OP(kid);
0997db6f
TC		 772 }
773 }
774 if (type == OP_NULL)
775 type = (OPCODE)o->op_targ;
acb36ea4 776
0997db6f
TC		 777 if (o->op_slabbed)
778 Slab_to_rw(OpSLAB(o));
fc97af9c 779
0997db6f
TC		 780 /* COP* is not cleared by op_clear() so that we may track line
781 * numbers etc even after null() */
782 if (type == OP_NEXTSTATE || type == OP_DBSTATE) {
783 cop_free((COP*)o);
784 }
acb36ea4 785
0997db6f
TC		 786 op_clear(o);
787 FreeOp(o);
4d494880 788#ifdef DEBUG_LEAKING_SCALARS
0997db6f
TC		 789 if (PL_op == o)
790 PL_op = NULL;
4d494880 791#endif
aa9d1253 792 } while ( (o = POP_DEFERRED_OP()) );
0997db6f
TC		 793
794 Safefree(defer_stack);
acb36ea4 795}
79072805 796
ab576797
DM		 797/* S_op_clear_gv(): free a GV attached to an OP */
798
799#ifdef USE_ITHREADS
800void S_op_clear_gv(pTHX_ OP *o, PADOFFSET *ixp)
801#else
802void S_op_clear_gv(pTHX_ OP *o, SV**svp)
803#endif
804{
805
fedf30e1
DM		 806 GV *gv = (o->op_type == OP_GV || o->op_type == OP_GVSV
807 || o->op_type == OP_MULTIDEREF)
ab576797
DM		 808#ifdef USE_ITHREADS
809 && PL_curpad
810 ? ((GV*)PAD_SVl(*ixp)) : NULL;
811#else
812 ? (GV*)(*svp) : NULL;
813#endif
814 /* It's possible during global destruction that the GV is freed
815 before the optree. Whilst the SvREFCNT_inc is happy to bump from
816 0 to 1 on a freed SV, the corresponding SvREFCNT_dec from 1 to 0
817 will trigger an assertion failure, because the entry to sv_clear
818 checks that the scalar is not already freed. A check of for
819 !SvIS_FREED(gv) turns out to be invalid, because during global
820 destruction the reference count can be forced down to zero
821 (with SVf_BREAK set). In which case raising to 1 and then
822 dropping to 0 triggers cleanup before it should happen. I
823 *think* that this might actually be a general, systematic,
824 weakness of the whole idea of SVf_BREAK, in that code *is*
825 allowed to raise and lower references during global destruction,
826 so any *valid* code that happens to do this during global
827 destruction might well trigger premature cleanup. */
828 bool still_valid = gv && SvREFCNT(gv);
829
830 if (still_valid)
831 SvREFCNT_inc_simple_void(gv);
832#ifdef USE_ITHREADS
833 if (*ixp > 0) {
834 pad_swipe(*ixp, TRUE);
835 *ixp = 0;
836 }
837#else
838 SvREFCNT_dec(*svp);
839 *svp = NULL;
840#endif
841 if (still_valid) {
842 int try_downgrade = SvREFCNT(gv) == 2;
843 SvREFCNT_dec_NN(gv);
844 if (try_downgrade)
845 gv_try_downgrade(gv);
846 }
847}
848
849
93c66552
DM		 850void
851Perl_op_clear(pTHX_ OP *o)
acb36ea4 852{
13137afc 853
27da23d5 854 dVAR;
7918f24d
NC		 855
856 PERL_ARGS_ASSERT_OP_CLEAR;
857
11343788 858 switch (o->op_type) {
acb36ea4 859 case OP_NULL: /* Was holding old type, if any. */
c67159e1 860 /* FALLTHROUGH */
4d193d44 861 case OP_ENTERTRY:
acb36ea4 862 case OP_ENTEREVAL: /* Was holding hints. */
acb36ea4 863 o->op_targ = 0;
a0d0e21e 864 break;
a6006777 865 default:
ac4c12e7 866 if (!(o->op_flags & OPf_REF)
ef69c8fc 867 || (PL_check[o->op_type] != Perl_ck_ftst))
a6006777 868 break;
924ba076 869 /* FALLTHROUGH */
463ee0b2 870 case OP_GVSV:
79072805 871 case OP_GV:
a6006777 872 case OP_AELEMFAST:
f7461760 873#ifdef USE_ITHREADS
ab576797 874 S_op_clear_gv(aTHX_ o, &(cPADOPx(o)->op_padix));
350de78d 875#else
ab576797 876 S_op_clear_gv(aTHX_ o, &(cSVOPx(o)->op_sv));
350de78d 877#endif
79072805 878 break;
810bd8b7 879 case OP_METHOD_REDIR:
880 case OP_METHOD_REDIR_SUPER:
881#ifdef USE_ITHREADS
882 if (cMETHOPx(o)->op_rclass_targ) {
883 pad_swipe(cMETHOPx(o)->op_rclass_targ, 1);
884 cMETHOPx(o)->op_rclass_targ = 0;
885 }
886#else
887 SvREFCNT_dec(cMETHOPx(o)->op_rclass_sv);
888 cMETHOPx(o)->op_rclass_sv = NULL;
889#endif
a1ae71d2 890 case OP_METHOD_NAMED:
7d6c333c 891 case OP_METHOD_SUPER:
b46e009d 892 SvREFCNT_dec(cMETHOPx(o)->op_u.op_meth_sv);
893 cMETHOPx(o)->op_u.op_meth_sv = NULL;
894#ifdef USE_ITHREADS
895 if (o->op_targ) {
896 pad_swipe(o->op_targ, 1);
897 o->op_targ = 0;
898 }
899#endif
900 break;
79072805 901 case OP_CONST:
996c9baa 902 case OP_HINTSEVAL:
11343788 903 SvREFCNT_dec(cSVOPo->op_sv);
a0714e2c 904 cSVOPo->op_sv = NULL;
3b1c21fa
AB		 905#ifdef USE_ITHREADS
906 /** Bug #15654
907 Even if op_clear does a pad_free for the target of the op,
6a077020 908 pad_free doesn't actually remove the sv that exists in the pad;
3b1c21fa
AB		 909 instead it lives on. This results in that it could be reused as
910 a target later on when the pad was reallocated.
911 **/
912 if(o->op_targ) {
913 pad_swipe(o->op_targ,1);
914 o->op_targ = 0;
915 }
916#endif
79072805 917 break;
c9df4fda 918 case OP_DUMP:
748a9306
LW		 919 case OP_GOTO:
920 case OP_NEXT:
921 case OP_LAST:
922 case OP_REDO:
11343788 923 if (o->op_flags & (OPf_SPECIAL|OPf_STACKED|OPf_KIDS))
748a9306 924 break;
924ba076 925 /* FALLTHROUGH */
a0d0e21e 926 case OP_TRANS:
bb16bae8 927 case OP_TRANSR:
acb36ea4 928 if (o->op_private & (OPpTRANS_FROM_UTF|OPpTRANS_TO_UTF)) {
99a1d0d1 929 assert(o->op_type == OP_TRANS || o->op_type == OP_TRANSR);
043e41b8
DM		 930#ifdef USE_ITHREADS
931 if (cPADOPo->op_padix > 0) {
932 pad_swipe(cPADOPo->op_padix, TRUE);
933 cPADOPo->op_padix = 0;
934 }
935#else
a0ed51b3 936 SvREFCNT_dec(cSVOPo->op_sv);
a0714e2c 937 cSVOPo->op_sv = NULL;
043e41b8 938#endif
acb36ea4
GS		 939 }
940 else {
ea71c68d 941 PerlMemShared_free(cPVOPo->op_pv);
bd61b366 942 cPVOPo->op_pv = NULL;
acb36ea4 943 }
a0d0e21e
LW		 944 break;
945 case OP_SUBST:
20e98b0f 946 op_free(cPMOPo->op_pmreplrootu.op_pmreplroot);
971a9dd3 947 goto clear_pmop;
748a9306 948 case OP_PUSHRE:
971a9dd3 949#ifdef USE_ITHREADS
20e98b0f 950 if (cPMOPo->op_pmreplrootu.op_pmtargetoff) {
20e98b0f 951 pad_swipe(cPMOPo->op_pmreplrootu.op_pmtargetoff, TRUE);
971a9dd3
GS		 952 }
953#else
ad64d0ec 954 SvREFCNT_dec(MUTABLE_SV(cPMOPo->op_pmreplrootu.op_pmtargetgv));
971a9dd3 955#endif
924ba076 956 /* FALLTHROUGH */
a0d0e21e 957 case OP_MATCH:
8782bef2 958 case OP_QR:
7b52d656 959 clear_pmop:
867940b8
DM		 960 if (!(cPMOPo->op_pmflags & PMf_CODELIST_PRIVATE))
961 op_free(cPMOPo->op_code_list);
68e2671b 962 cPMOPo->op_code_list = NULL;
23083432 963 forget_pmop(cPMOPo);
20e98b0f 964 cPMOPo->op_pmreplrootu.op_pmreplroot = NULL;
9cddf794
NC		 965 /* we use the same protection as the "SAFE" version of the PM_ macros
966 * here since sv_clean_all might release some PMOPs
5f8cb046
DM		 967 * after PL_regex_padav has been cleared
968 * and the clearing of PL_regex_padav needs to
969 * happen before sv_clean_all
970 */
13137afc
AB		 971#ifdef USE_ITHREADS
972 if(PL_regex_pad) { /* We could be in destruction */
402d2eb1 973 const IV offset = (cPMOPo)->op_pmoffset;
9cddf794 974 ReREFCNT_dec(PM_GETRE(cPMOPo));
402d2eb1
NC		 975 PL_regex_pad[offset] = &PL_sv_undef;
976 sv_catpvn_nomg(PL_regex_pad[0], (const char *)&offset,
977 sizeof(offset));
13137afc 978 }
9cddf794
NC		 979#else
980 ReREFCNT_dec(PM_GETRE(cPMOPo));
981 PM_SETRE(cPMOPo, NULL);
1eb1540c 982#endif
13137afc 983
a0d0e21e 984 break;
fedf30e1
DM		 985
986 case OP_MULTIDEREF:
987 {
988 UNOP_AUX_item *items = cUNOP_AUXo->op_aux;
989 UV actions = items->uv;
990 bool last = 0;
991 bool is_hash = FALSE;
992
993 while (!last) {
994 switch (actions & MDEREF_ACTION_MASK) {
995
996 case MDEREF_reload:
997 actions = (++items)->uv;
998 continue;
999
1000 case MDEREF_HV_padhv_helem:
1001 is_hash = TRUE;
1002 case MDEREF_AV_padav_aelem:
1003 pad_free((++items)->pad_offset);
1004 goto do_elem;
1005
1006 case MDEREF_HV_gvhv_helem:
1007 is_hash = TRUE;
1008 case MDEREF_AV_gvav_aelem:
1009#ifdef USE_ITHREADS
1010 S_op_clear_gv(aTHX_ o, &((++items)->pad_offset));
1011#else
1012 S_op_clear_gv(aTHX_ o, &((++items)->sv));
1013#endif
1014 goto do_elem;
1015
1016 case MDEREF_HV_gvsv_vivify_rv2hv_helem:
1017 is_hash = TRUE;
1018 case MDEREF_AV_gvsv_vivify_rv2av_aelem:
1019#ifdef USE_ITHREADS
1020 S_op_clear_gv(aTHX_ o, &((++items)->pad_offset));
1021#else
1022 S_op_clear_gv(aTHX_ o, &((++items)->sv));
1023#endif
1024 goto do_vivify_rv2xv_elem;
1025
1026 case MDEREF_HV_padsv_vivify_rv2hv_helem:
1027 is_hash = TRUE;
1028 case MDEREF_AV_padsv_vivify_rv2av_aelem:
1029 pad_free((++items)->pad_offset);
1030 goto do_vivify_rv2xv_elem;
1031
1032 case MDEREF_HV_pop_rv2hv_helem:
1033 case MDEREF_HV_vivify_rv2hv_helem:
1034 is_hash = TRUE;
1035 do_vivify_rv2xv_elem:
1036 case MDEREF_AV_pop_rv2av_aelem:
1037 case MDEREF_AV_vivify_rv2av_aelem:
1038 do_elem:
1039 switch (actions & MDEREF_INDEX_MASK) {
1040 case MDEREF_INDEX_none:
1041 last = 1;
1042 break;
1043 case MDEREF_INDEX_const:
1044 if (is_hash) {
1045#ifdef USE_ITHREADS
1046 /* see RT #15654 */
1047 pad_swipe((++items)->pad_offset, 1);
1048#else
1049 SvREFCNT_dec((++items)->sv);
1050#endif
1051 }
1052 else
1053 items++;
1054 break;
1055 case MDEREF_INDEX_padsv:
1056 pad_free((++items)->pad_offset);
1057 break;
1058 case MDEREF_INDEX_gvsv:
1059#ifdef USE_ITHREADS
1060 S_op_clear_gv(aTHX_ o, &((++items)->pad_offset));
1061#else
1062 S_op_clear_gv(aTHX_ o, &((++items)->sv));
1063#endif
1064 break;
1065 }
1066
1067 if (actions & MDEREF_FLAG_last)
1068 last = 1;
1069 is_hash = FALSE;
1070
1071 break;
1072
1073 default:
1074 assert(0);
1075 last = 1;
1076 break;
1077
1078 } /* switch */
1079
1080 actions >>= MDEREF_SHIFT;
1081 } /* while */
1082
1083 /* start of malloc is at op_aux[-1], where the length is
1084 * stored */
1085 PerlMemShared_free(cUNOP_AUXo->op_aux - 1);
1086 }
1087 break;
79072805
LW		 1088 }
1089
743e66e6 1090 if (o->op_targ > 0) {
11343788 1091 pad_free(o->op_targ);
743e66e6
GS		 1092 o->op_targ = 0;
1093 }
79072805
LW		 1094}
1095
76e3520e 1096STATIC void
3eb57f73
HS		 1097S_cop_free(pTHX_ COP* cop)
1098{
7918f24d
NC		 1099 PERL_ARGS_ASSERT_COP_FREE;
1100
05ec9bb3 1101 CopFILE_free(cop);
0453d815 1102 if (! specialWARN(cop->cop_warnings))
72dc9ed5 1103 PerlMemShared_free(cop->cop_warnings);
20439bc7 1104 cophh_free(CopHINTHASH_get(cop));
515abc43
FC		 1105 if (PL_curcop == cop)
1106 PL_curcop = NULL;
3eb57f73
HS		 1107}
1108
c2b1997a 1109STATIC void
c4bd3ae5 1110S_forget_pmop(pTHX_ PMOP *const o
c4bd3ae5 1111 )
c2b1997a
NC		 1112{
1113 HV * const pmstash = PmopSTASH(o);
7918f24d
NC		 1114
1115 PERL_ARGS_ASSERT_FORGET_PMOP;
1116
e39a6381 1117 if (pmstash && !SvIS_FREED(pmstash) && SvMAGICAL(pmstash)) {
ad64d0ec 1118 MAGIC * const mg = mg_find((const SV *)pmstash, PERL_MAGIC_symtab);
c2b1997a
NC		 1119 if (mg) {
1120 PMOP **const array = (PMOP**) mg->mg_ptr;
1121 U32 count = mg->mg_len / sizeof(PMOP**);
1122 U32 i = count;
1123
1124 while (i--) {
1125 if (array[i] == o) {
1126 /* Found it. Move the entry at the end to overwrite it. */
1127 array[i] = array[--count];
1128 mg->mg_len = count * sizeof(PMOP**);
1129 /* Could realloc smaller at this point always, but probably
1130 not worth it. Probably worth free()ing if we're the
1131 last. */
1132 if(!count) {
1133 Safefree(mg->mg_ptr);
1134 mg->mg_ptr = NULL;
1135 }
1136 break;
1137 }
1138 }
1139 }
1140 }
1cdf7faf
NC		 1141 if (PL_curpm == o)
1142 PL_curpm = NULL;
c2b1997a
NC		 1143}
1144
bfd0ff22
NC		 1145STATIC void
1146S_find_and_forget_pmops(pTHX_ OP *o)
1147{
7918f24d
NC		 1148 PERL_ARGS_ASSERT_FIND_AND_FORGET_PMOPS;
1149
bfd0ff22
NC		 1150 if (o->op_flags & OPf_KIDS) {
1151 OP *kid = cUNOPo->op_first;
1152 while (kid) {
1153 switch (kid->op_type) {
1154 case OP_SUBST:
1155 case OP_PUSHRE:
1156 case OP_MATCH:
1157 case OP_QR:
23083432 1158 forget_pmop((PMOP*)kid);
bfd0ff22
NC		 1159 }
1160 find_and_forget_pmops(kid);
e6dae479 1161 kid = OpSIBLING(kid);
bfd0ff22
NC		 1162 }
1163 }
1164}
1165
6e53b6ca
DD		 1166/*
1167=for apidoc Am|void|op_null|OP *o
1168
1169Neutralizes an op when it is no longer needed, but is still linked to from
1170other ops.
1171
1172=cut
1173*/
1174
93c66552
DM		 1175void
1176Perl_op_null(pTHX_ OP *o)
8990e307 1177{
27da23d5 1178 dVAR;
7918f24d
NC		 1179
1180 PERL_ARGS_ASSERT_OP_NULL;
1181
acb36ea4
GS		 1182 if (o->op_type == OP_NULL)
1183 return;
b5bbe64a 1184 op_clear(o);
11343788 1185 o->op_targ = o->op_type;
b9a07097 1186 OpTYPE_set(o, OP_NULL);
8990e307
LW		 1187}
1188
4026c95a
SH		 1189void
1190Perl_op_refcnt_lock(pTHX)
1191{
20b7effb 1192#ifdef USE_ITHREADS
27da23d5 1193 dVAR;
20b7effb 1194#endif
96a5add6 1195 PERL_UNUSED_CONTEXT;
4026c95a
SH		 1196 OP_REFCNT_LOCK;
1197}
1198
1199void
1200Perl_op_refcnt_unlock(pTHX)
1201{
20b7effb 1202#ifdef USE_ITHREADS
27da23d5 1203 dVAR;
20b7effb 1204#endif
96a5add6 1205 PERL_UNUSED_CONTEXT;
4026c95a
SH		 1206 OP_REFCNT_UNLOCK;
1207}
1208
3253bf85
DM		 1209
1210/*
1211=for apidoc op_sibling_splice
1212
1213A general function for editing the structure of an existing chain of
7e234f81 1214op_sibling nodes. By analogy with the perl-level splice() function, allows
3253bf85
DM		 1215you to delete zero or more sequential nodes, replacing them with zero or
1216more different nodes. Performs the necessary op_first/op_last
29e61fd9 1217housekeeping on the parent node and op_sibling manipulation on the
7e234f81 1218children. The last deleted node will be marked as as the last node by
87b5a8b9 1219updating the op_sibling/op_sibparent or op_moresib field as appropriate.
3253bf85
DM		 1220
1221Note that op_next is not manipulated, and nodes are not freed; that is the
7e234f81 1222responsibility of the caller. It also won't create a new list op for an
8ae26bff 1223empty list etc; use higher-level functions like op_append_elem() for that.
3253bf85 1224
3269ea41
DM		 1225parent is the parent node of the sibling chain. It may passed as NULL if
1226the splicing doesn't affect the first or last op in the chain.
3253bf85 1227
7e234f81
FC		 1228start is the node preceding the first node to be spliced. Node(s)
1229following it will be deleted, and ops will be inserted after it. If it is
3253bf85
DM		 1230NULL, the first node onwards is deleted, and nodes are inserted at the
1231beginning.
1232
7e234f81 1233del_count is the number of nodes to delete. If zero, no nodes are deleted.
3253bf85
DM		 1234If -1 or greater than or equal to the number of remaining kids, all
1235remaining kids are deleted.
1236
1237insert is the first of a chain of nodes to be inserted in place of the nodes.
1238If NULL, no nodes are inserted.
1239
8ae26bff 1240The head of the chain of deleted ops is returned, or NULL if no ops were
3253bf85
DM		 1241deleted.
1242
1243For example:
1244
1245 action before after returns
1246 ------ ----- ----- -------
1247
1248 P P
8ae26bff
DM		 1249 splice(P, A, 2, X-Y-Z) | | B-C
1250 A-B-C-D A-X-Y-Z-D
3253bf85
DM		 1251
1252 P P
1253 splice(P, NULL, 1, X-Y) | | A
1254 A-B-C-D X-Y-B-C-D
1255
1256 P P
8ae26bff
DM		 1257 splice(P, NULL, 3, NULL) | | A-B-C
1258 A-B-C-D D
3253bf85
DM		 1259
1260 P P
1261 splice(P, B, 0, X-Y) | | NULL
1262 A-B-C-D A-B-X-Y-C-D
1263
5e24af7d
DM		 1264
1265For lower-level direct manipulation of C<op_sibparent> and C<op_moresib>,
fbe13c60 1266see C<L</OpMORESIB_set>>, C<L</OpLASTSIB_set>>, C<L</OpMAYBESIB_set>>.
5e24af7d 1267
3253bf85
DM		 1268=cut
1269*/
1270
1271OP *
8ae26bff 1272Perl_op_sibling_splice(OP *parent, OP *start, int del_count, OP* insert)
3253bf85 1273{
3269ea41 1274 OP *first;
3253bf85
DM		 1275 OP *rest;
1276 OP *last_del = NULL;
1277 OP *last_ins = NULL;
1278
3269ea41
DM		 1279 if (start)
1280 first = OpSIBLING(start);
1281 else if (!parent)
1282 goto no_parent;
1283 else
1284 first = cLISTOPx(parent)->op_first;
3253bf85
DM		 1285
1286 assert(del_count >= -1);
1287
1288 if (del_count && first) {
1289 last_del = first;
e6dae479
FC		 1290 while (--del_count && OpHAS_SIBLING(last_del))
1291 last_del = OpSIBLING(last_del);
1292 rest = OpSIBLING(last_del);
5e24af7d 1293 OpLASTSIB_set(last_del, NULL);
3253bf85
DM		 1294 }
1295 else
1296 rest = first;
1297
1298 if (insert) {
1299 last_ins = insert;
e6dae479
FC		 1300 while (OpHAS_SIBLING(last_ins))
1301 last_ins = OpSIBLING(last_ins);
5e24af7d 1302 OpMAYBESIB_set(last_ins, rest, NULL);
3253bf85
DM		 1303 }
1304 else
1305 insert = rest;
1306
29e61fd9 1307 if (start) {
5e24af7d 1308 OpMAYBESIB_set(start, insert, NULL);
29e61fd9 1309 }
b3e29a8d 1310 else {
3269ea41
DM		 1311 if (!parent)
1312 goto no_parent;
3253bf85 1313 cLISTOPx(parent)->op_first = insert;
b3e29a8d
DM		 1314 if (insert)
1315 parent->op_flags |= OPf_KIDS;
1316 else
1317 parent->op_flags &= ~OPf_KIDS;
1318 }
3253bf85
DM		 1319
1320 if (!rest) {
29e61fd9 1321 /* update op_last etc */
3269ea41 1322 U32 type;
29e61fd9 1323 OP *lastop;
3253bf85 1324
3269ea41
DM		 1325 if (!parent)
1326 goto no_parent;
1327
05039abd
DM		 1328 /* ought to use OP_CLASS(parent) here, but that can't handle
1329 * ex-foo OP_NULL ops. Also note that XopENTRYCUSTOM() can't
1330 * either */
3269ea41 1331 type = parent->op_type;
05039abd
DM		 1332 if (type == OP_CUSTOM) {
1333 dTHX;
1334 type = XopENTRYCUSTOM(parent, xop_class);
1335 }
1336 else {
1337 if (type == OP_NULL)
1338 type = parent->op_targ;
1339 type = PL_opargs[type] & OA_CLASS_MASK;
1340 }
3253bf85 1341
29e61fd9 1342 lastop = last_ins ? last_ins : start ? start : NULL;
3253bf85
DM		 1343 if ( type == OA_BINOP
1344 || type == OA_LISTOP
1345 || type == OA_PMOP
1346 || type == OA_LOOP
1347 )
29e61fd9
DM		 1348 cLISTOPx(parent)->op_last = lastop;
1349
5e24af7d
DM		 1350 if (lastop)
1351 OpLASTSIB_set(lastop, parent);
3253bf85
DM		 1352 }
1353 return last_del ? first : NULL;
3269ea41
DM		 1354
1355 no_parent:
1356 Perl_croak_nocontext("panic: op_sibling_splice(): NULL parent");
3253bf85
DM		 1357}
1358
3269ea41 1359
1fafe688
DM		 1360#ifdef PERL_OP_PARENT
1361
29e61fd9
DM		 1362/*
1363=for apidoc op_parent
1364
1fafe688
DM		 1365Returns the parent OP of o, if it has a parent. Returns NULL otherwise.
1366This function is only available on perls built with C<-DPERL_OP_PARENT>.
29e61fd9
DM		 1367
1368=cut
1369*/
1370
1371OP *
8ae26bff 1372Perl_op_parent(OP *o)
29e61fd9
DM		 1373{
1374 PERL_ARGS_ASSERT_OP_PARENT;
e6dae479
FC		 1375 while (OpHAS_SIBLING(o))
1376 o = OpSIBLING(o);
86cd3a13 1377 return o->op_sibparent;
29e61fd9
DM		 1378}
1379
1fafe688
DM		 1380#endif
1381
3253bf85
DM		 1382
1383/* replace the sibling following start with a new UNOP, which becomes
1384 * the parent of the original sibling; e.g.
1385 *
1386 * op_sibling_newUNOP(P, A, unop-args...)
1387 *
1388 * P P
1389 * | becomes |
1390 * A-B-C A-U-C
1391 * |
1392 * B
1393 *
1394 * where U is the new UNOP.
1395 *
1396 * parent and start args are the same as for op_sibling_splice();
1397 * type and flags args are as newUNOP().
1398 *
1399 * Returns the new UNOP.
1400 */
1401
1402OP *
1403S_op_sibling_newUNOP(pTHX_ OP *parent, OP *start, I32 type, I32 flags)
1404{
1405 OP *kid, *newop;
1406
1407 kid = op_sibling_splice(parent, start, 1, NULL);
1408 newop = newUNOP(type, flags, kid);
1409 op_sibling_splice(parent, start, 0, newop);
1410 return newop;
1411}
1412
1413
1414/* lowest-level newLOGOP-style function - just allocates and populates
1415 * the struct. Higher-level stuff should be done by S_new_logop() /
1416 * newLOGOP(). This function exists mainly to avoid op_first assignment
1417 * being spread throughout this file.
1418 */
1419
1420LOGOP *
1421S_alloc_LOGOP(pTHX_ I32 type, OP *first, OP* other)
1422{
1e8db68a 1423 dVAR;
3253bf85 1424 LOGOP *logop;
29e61fd9 1425 OP *kid = first;
3253bf85 1426 NewOp(1101, logop, 1, LOGOP);
b9a07097 1427 OpTYPE_set(logop, type);
3253bf85
DM		 1428 logop->op_first = first;
1429 logop->op_other = other;
1430 logop->op_flags = OPf_KIDS;
e6dae479
FC		 1431 while (kid && OpHAS_SIBLING(kid))
1432 kid = OpSIBLING(kid);
5e24af7d
DM		 1433 if (kid)
1434 OpLASTSIB_set(kid, (OP*)logop);
3253bf85
DM		 1435 return logop;
1436}
1437
1438
79072805
LW		 1439/* Contextualizers */
1440
d9088386
Z		 1441/*
1442=for apidoc Am|OP *|op_contextualize|OP *o|I32 context
1443
1444Applies a syntactic context to an op tree representing an expression.
2d7f6611 1445C<o> is the op tree, and C<context> must be C<G_SCALAR>, C<G_ARRAY>,
d9088386
Z		 1446or C<G_VOID> to specify the context to apply. The modified op tree
1447is returned.
1448
1449=cut
1450*/
1451
1452OP *
1453Perl_op_contextualize(pTHX_ OP *o, I32 context)
1454{
1455 PERL_ARGS_ASSERT_OP_CONTEXTUALIZE;
1456 switch (context) {
1457 case G_SCALAR: return scalar(o);
1458 case G_ARRAY: return list(o);
1459 case G_VOID: return scalarvoid(o);
1460 default:
5637ef5b
NC		 1461 Perl_croak(aTHX_ "panic: op_contextualize bad context %ld",
1462 (long) context);
d9088386
Z		 1463 }
1464}
1465
5983a79d 1466/*
79072805 1467
5983a79d 1468=for apidoc Am|OP*|op_linklist|OP *o
72d33970 1469This function is the implementation of the L</LINKLIST> macro. It should
5983a79d
BM		 1470not be called directly.
1471
1472=cut
1473*/
1474
1475OP *
1476Perl_op_linklist(pTHX_ OP *o)
79072805 1477{
3edf23ff 1478 OP *first;
79072805 1479
5983a79d 1480 PERL_ARGS_ASSERT_OP_LINKLIST;
7918f24d 1481
11343788
MB		 1482 if (o->op_next)
1483 return o->op_next;
79072805
LW		 1484
1485 /* establish postfix order */
3edf23ff
AL		 1486 first = cUNOPo->op_first;
1487 if (first) {
eb578fdb 1488 OP *kid;
3edf23ff
AL		 1489 o->op_next = LINKLIST(first);
1490 kid = first;
1491 for (;;) {
e6dae479 1492 OP *sibl = OpSIBLING(kid);
29e61fd9
DM		 1493 if (sibl) {
1494 kid->op_next = LINKLIST(sibl);
1495 kid = sibl;
3edf23ff 1496 } else {
11343788 1497 kid->op_next = o;
3edf23ff
AL		 1498 break;
1499 }
79072805
LW		 1500 }
1501 }
1502 else
11343788 1503 o->op_next = o;
79072805 1504
11343788 1505 return o->op_next;
79072805
LW		 1506}
1507
1f676739 1508static OP *
2dd5337b 1509S_scalarkids(pTHX_ OP *o)
79072805 1510{
11343788 1511 if (o && o->op_flags & OPf_KIDS) {
bfed75c6 1512 OP *kid;
e6dae479 1513 for (kid = cLISTOPo->op_first; kid; kid = OpSIBLING(kid))
79072805
LW		 1514 scalar(kid);
1515 }
11343788 1516 return o;
79072805
LW		 1517}
1518
76e3520e 1519STATIC OP *
cea2e8a9 1520S_scalarboolean(pTHX_ OP *o)
8990e307 1521{
7918f24d
NC		 1522 PERL_ARGS_ASSERT_SCALARBOOLEAN;
1523
6b7c6d95
FC		 1524 if (o->op_type == OP_SASSIGN && cBINOPo->op_first->op_type == OP_CONST
1525 && !(cBINOPo->op_first->op_flags & OPf_SPECIAL)) {
d008e5eb 1526 if (ckWARN(WARN_SYNTAX)) {
6867be6d 1527 const line_t oldline = CopLINE(PL_curcop);
a0d0e21e 1528
2b7cddde
NC		 1529 if (PL_parser && PL_parser->copline != NOLINE) {
1530 /* This ensures that warnings are reported at the first line
1531 of the conditional, not the last. */
53a7735b 1532 CopLINE_set(PL_curcop, PL_parser->copline);
2b7cddde 1533 }
9014280d 1534 Perl_warner(aTHX_ packWARN(WARN_SYNTAX), "Found = in conditional, should be ==");
57843af0 1535 CopLINE_set(PL_curcop, oldline);
d008e5eb 1536 }
a0d0e21e 1537 }
11343788 1538 return scalar(o);
8990e307
LW		 1539}
1540
0920b7fa
FC		 1541static SV *
1542S_op_varname(pTHX_ const OP *o)
1543{
1544 assert(o);
1545 assert(o->op_type == OP_PADAV || o->op_type == OP_RV2AV ||
1546 o->op_type == OP_PADHV || o->op_type == OP_RV2HV);
1547 {
1548 const char funny = o->op_type == OP_PADAV
1549 || o->op_type == OP_RV2AV ? '@' : '%';
1550 if (o->op_type == OP_RV2AV || o->op_type == OP_RV2HV) {
1551 GV *gv;
1552 if (cUNOPo->op_first->op_type != OP_GV
1553 || !(gv = cGVOPx_gv(cUNOPo->op_first)))
1554 return NULL;
1555 return varname(gv, funny, 0, NULL, 0, 1);
1556 }
1557 return
1558 varname(MUTABLE_GV(PL_compcv), funny, o->op_targ, NULL, 0, 1);
1559 }
1560}
1561
429a2555 1562static void
2186f873
FC		 1563S_op_pretty(pTHX_ const OP *o, SV **retsv, const char **retpv)
1564{ /* or not so pretty :-) */
2186f873
FC		 1565 if (o->op_type == OP_CONST) {
1566 *retsv = cSVOPo_sv;
1567 if (SvPOK(*retsv)) {
1568 SV *sv = *retsv;
1569 *retsv = sv_newmortal();
1570 pv_pretty(*retsv, SvPVX_const(sv), SvCUR(sv), 32, NULL, NULL,
1571 PERL_PV_PRETTY_DUMP |PERL_PV_ESCAPE_UNI_DETECT);
1572 }
1573 else if (!SvOK(*retsv))
1574 *retpv = "undef";
1575 }
1576 else *retpv = "...";
1577}
1578
1579static void
429a2555
FC		 1580S_scalar_slice_warning(pTHX_ const OP *o)
1581{
1582 OP *kid;
1583 const char lbrack =
2186f873 1584 o->op_type == OP_HSLICE ? '{' : '[';
429a2555 1585 const char rbrack =
2186f873 1586 o->op_type == OP_HSLICE ? '}' : ']';
429a2555 1587 SV *name;
32e9ec8f 1588 SV *keysv = NULL; /* just to silence compiler warnings */
429a2555
FC		 1589 const char *key = NULL;
1590
1591 if (!(o->op_private & OPpSLICEWARNING))
1592 return;
1593 if (PL_parser && PL_parser->error_count)
1594 /* This warning can be nonsensical when there is a syntax error. */
1595 return;
1596
1597 kid = cLISTOPo->op_first;
e6dae479 1598 kid = OpSIBLING(kid); /* get past pushmark */
429a2555
FC		 1599 /* weed out false positives: any ops that can return lists */
1600 switch (kid->op_type) {
1601 case OP_BACKTICK:
1602 case OP_GLOB:
1603 case OP_READLINE:
1604 case OP_MATCH:
1605 case OP_RV2AV:
1606 case OP_EACH:
1607 case OP_VALUES:
1608 case OP_KEYS:
1609 case OP_SPLIT:
1610 case OP_LIST:
1611 case OP_SORT:
1612 case OP_REVERSE:
1613 case OP_ENTERSUB:
1614 case OP_CALLER:
1615 case OP_LSTAT:
1616 case OP_STAT:
1617 case OP_READDIR:
1618 case OP_SYSTEM:
1619 case OP_TMS:
1620 case OP_LOCALTIME:
1621 case OP_GMTIME:
1622 case OP_ENTEREVAL:
429a2555
FC		 1623 return;
1624 }
7d3c8a68
S		 1625
1626 /* Don't warn if we have a nulled list either. */
1627 if (kid->op_type == OP_NULL && kid->op_targ == OP_LIST)
1628 return;
1629
e6dae479
FC		 1630 assert(OpSIBLING(kid));
1631 name = S_op_varname(aTHX_ OpSIBLING(kid));
429a2555
FC		 1632 if (!name) /* XS module fiddling with the op tree */
1633 return;
2186f873 1634 S_op_pretty(aTHX_ kid, &keysv, &key);
429a2555
FC		 1635 assert(SvPOK(name));
1636 sv_chop(name,SvPVX(name)+1);
1637 if (key)
2186f873 1638 /* diag_listed_as: Scalar value @%s[%s] better written as $%s[%s] */
429a2555 1639 Perl_warner(aTHX_ packWARN(WARN_SYNTAX),
2186f873 1640 "Scalar value @%"SVf"%c%s%c better written as $%"SVf
429a2555 1641 "%c%s%c",
2186f873 1642 SVfARG(name), lbrack, key, rbrack, SVfARG(name),
429a2555
FC		 1643 lbrack, key, rbrack);
1644 else
2186f873 1645 /* diag_listed_as: Scalar value @%s[%s] better written as $%s[%s] */
429a2555 1646 Perl_warner(aTHX_ packWARN(WARN_SYNTAX),
2186f873 1647 "Scalar value @%"SVf"%c%"SVf"%c better written as $%"
429a2555 1648 SVf"%c%"SVf"%c",
c1f6cd39
BF		 1649 SVfARG(name), lbrack, SVfARG(keysv), rbrack,
1650 SVfARG(name), lbrack, SVfARG(keysv), rbrack);
429a2555
FC		 1651}
1652
8990e307 1653OP *
864dbfa3 1654Perl_scalar(pTHX_ OP *o)
79072805
LW		 1655{
1656 OP *kid;
1657
a0d0e21e 1658 /* assumes no premature commitment */
13765c85
DM		 1659 if (!o || (PL_parser && PL_parser->error_count)
1660 || (o->op_flags & OPf_WANT)
5dc0d613 1661 || o->op_type == OP_RETURN)
7e363e51 1662 {
11343788 1663 return o;
7e363e51 1664 }
79072805 1665
5dc0d613 1666 o->op_flags = (o->op_flags & ~OPf_WANT) | OPf_WANT_SCALAR;
79072805 1667
11343788 1668 switch (o->op_type) {
79072805 1669 case OP_REPEAT:
11343788 1670 scalar(cBINOPo->op_first);
82e4f303
FC		 1671 if (o->op_private & OPpREPEAT_DOLIST) {
1672 kid = cLISTOPx(cUNOPo->op_first)->op_first;
1673 assert(kid->op_type == OP_PUSHMARK);
e6dae479 1674 if (OpHAS_SIBLING(kid) && !OpHAS_SIBLING(OpSIBLING(kid))) {
82e4f303
FC		 1675 op_null(cLISTOPx(cUNOPo->op_first)->op_first);
1676 o->op_private &=~ OPpREPEAT_DOLIST;
1677 }
1678 }
8990e307 1679 break;
79072805
LW		 1680 case OP_OR:
1681 case OP_AND:
1682 case OP_COND_EXPR:
e6dae479 1683 for (kid = OpSIBLING(cUNOPo->op_first); kid; kid = OpSIBLING(kid))
8990e307 1684 scalar(kid);
79072805 1685 break;
924ba076 1686 /* FALLTHROUGH */
a6d8037e 1687 case OP_SPLIT:
79072805 1688 case OP_MATCH:
8782bef2 1689 case OP_QR:
79072805
LW		 1690 case OP_SUBST:
1691 case OP_NULL:
8990e307 1692 default:
11343788 1693 if (o->op_flags & OPf_KIDS) {
e6dae479 1694 for (kid = cUNOPo->op_first; kid; kid = OpSIBLING(kid))
8990e307
LW		 1695 scalar(kid);
1696 }
79072805
LW		 1697 break;
1698 case OP_LEAVE:
1699 case OP_LEAVETRY:
5dc0d613 1700 kid = cLISTOPo->op_first;
54310121 1701 scalar(kid);
e6dae479 1702 kid = OpSIBLING(kid);
25b991bf
VP		 1703 do_kids:
1704 while (kid) {
e6dae479 1705 OP *sib = OpSIBLING(kid);
34b54951 1706 if (sib && kid->op_type != OP_LEAVEWHEN
e6dae479 1707 && ( OpHAS_SIBLING(sib) || sib->op_type != OP_NULL
34b54951
FC		 1708 || ( sib->op_targ != OP_NEXTSTATE
1709 && sib->op_targ != OP_DBSTATE )))
c08f093b
VP		 1710 scalarvoid(kid);
1711 else
54310121 1712 scalar(kid);
25b991bf 1713 kid = sib;
54310121 1714 }
11206fdd 1715 PL_curcop = &PL_compiling;
54310121 1716 break;
748a9306 1717 case OP_SCOPE:
79072805 1718 case OP_LINESEQ:
8990e307 1719 case OP_LIST:
25b991bf
VP		 1720 kid = cLISTOPo->op_first;
1721 goto do_kids;
a801c63c 1722 case OP_SORT:
a2a5de95 1723 Perl_ck_warner(aTHX_ packWARN(WARN_VOID), "Useless use of sort in scalar context");
553e7bb0 1724 break;
95a31aad
FC		 1725 case OP_KVHSLICE:
1726 case OP_KVASLICE:
2186f873
FC		 1727 {
1728 /* Warn about scalar context */
1729 const char lbrack = o->op_type == OP_KVHSLICE ? '{' : '[';
1730 const char rbrack = o->op_type == OP_KVHSLICE ? '}' : ']';
1731 SV *name;
1732 SV *keysv;
1733 const char *key = NULL;
1734
1735 /* This warning can be nonsensical when there is a syntax error. */
1736 if (PL_parser && PL_parser->error_count)
1737 break;
1738
1739 if (!ckWARN(WARN_SYNTAX)) break;
1740
1741 kid = cLISTOPo->op_first;
e6dae479
FC		 1742 kid = OpSIBLING(kid); /* get past pushmark */
1743 assert(OpSIBLING(kid));
1744 name = S_op_varname(aTHX_ OpSIBLING(kid));
2186f873
FC		 1745 if (!name) /* XS module fiddling with the op tree */
1746 break;
1747 S_op_pretty(aTHX_ kid, &keysv, &key);
1748 assert(SvPOK(name));
1749 sv_chop(name,SvPVX(name)+1);
1750 if (key)
1751 /* diag_listed_as: %%s[%s] in scalar context better written as $%s[%s] */
1752 Perl_warner(aTHX_ packWARN(WARN_SYNTAX),
1753 "%%%"SVf"%c%s%c in scalar context better written "
1754 "as $%"SVf"%c%s%c",
1755 SVfARG(name), lbrack, key, rbrack, SVfARG(name),
1756 lbrack, key, rbrack);
1757 else
1758 /* diag_listed_as: %%s[%s] in scalar context better written as $%s[%s] */
1759 Perl_warner(aTHX_ packWARN(WARN_SYNTAX),
1760 "%%%"SVf"%c%"SVf"%c in scalar context better "
1761 "written as $%"SVf"%c%"SVf"%c",
c1f6cd39
BF		 1762 SVfARG(name), lbrack, SVfARG(keysv), rbrack,
1763 SVfARG(name), lbrack, SVfARG(keysv), rbrack);
2186f873 1764 }
79072805 1765 }
11343788 1766 return o;
79072805
LW		 1767}
1768
1769OP *
aa9d1253 1770Perl_scalarvoid(pTHX_ OP *arg)
79072805 1771{
27da23d5 1772 dVAR;
79072805 1773 OP *kid;
8990e307 1774 SV* sv;
2ebea0a1 1775 U8 want;
aa9d1253
TC		 1776 SSize_t defer_stack_alloc = 0;
1777 SSize_t defer_ix = -1;
1778 OP **defer_stack = NULL;
1779 OP *o = arg;
2ebea0a1 1780
7918f24d
NC		 1781 PERL_ARGS_ASSERT_SCALARVOID;
1782
aa9d1253
TC		 1783 do {
1784 SV *useless_sv = NULL;
1785 const char* useless = NULL;
1786
26f0e7d5
TC		 1787 if (o->op_type == OP_NEXTSTATE
1788 || o->op_type == OP_DBSTATE
1789 || (o->op_type == OP_NULL && (o->op_targ == OP_NEXTSTATE
1790 || o->op_targ == OP_DBSTATE)))
1791 PL_curcop = (COP*)o; /* for warning below */
1792
1793 /* assumes no premature commitment */
1794 want = o->op_flags & OPf_WANT;
1795 if ((want && want != OPf_WANT_SCALAR)
1796 || (PL_parser && PL_parser->error_count)
1797 || o->op_type == OP_RETURN || o->op_type == OP_REQUIRE || o->op_type == OP_LEAVEWHEN)
1798 {
1799 continue;
1800 }
1c846c1f 1801
26f0e7d5
TC		 1802 if ((o->op_private & OPpTARGET_MY)
1803 && (PL_opargs[o->op_type] & OA_TARGLEX))/* OPp share the meaning */
1804 {
0d18dd72
FC		 1805 /* newASSIGNOP has already applied scalar context, which we
1806 leave, as if this op is inside SASSIGN. */
26f0e7d5
TC		 1807 continue;
1808 }
79072805 1809
26f0e7d5 1810 o->op_flags = (o->op_flags & ~OPf_WANT) | OPf_WANT_VOID;
75068674 1811
26f0e7d5
TC		 1812 switch (o->op_type) {
1813 default:
1814 if (!(PL_opargs[o->op_type] & OA_FOLDCONST))
1815 break;
1816 /* FALLTHROUGH */
1817 case OP_REPEAT:
1818 if (o->op_flags & OPf_STACKED)
1819 break;
1e2dd519
FC		 1820 if (o->op_type == OP_REPEAT)
1821 scalar(cBINOPo->op_first);
26f0e7d5
TC		 1822 goto func_ops;
1823 case OP_SUBSTR:
1824 if (o->op_private == 4)
1825 break;
1826 /* FALLTHROUGH */
26f0e7d5
TC		 1827 case OP_WANTARRAY:
1828 case OP_GV:
1829 case OP_SMARTMATCH:
26f0e7d5
TC		 1830 case OP_AV2ARYLEN:
1831 case OP_REF:
1832 case OP_REFGEN:
1833 case OP_SREFGEN:
1834 case OP_DEFINED:
1835 case OP_HEX:
1836 case OP_OCT:
1837 case OP_LENGTH:
1838 case OP_VEC:
1839 case OP_INDEX:
1840 case OP_RINDEX:
1841 case OP_SPRINTF:
26f0e7d5 1842 case OP_KVASLICE:
26f0e7d5
TC		 1843 case OP_KVHSLICE:
1844 case OP_UNPACK:
1845 case OP_PACK:
1846 case OP_JOIN:
1847 case OP_LSLICE:
1848 case OP_ANONLIST:
1849 case OP_ANONHASH:
1850 case OP_SORT:
1851 case OP_REVERSE:
1852 case OP_RANGE:
1853 case OP_FLIP:
1854 case OP_FLOP:
1855 case OP_CALLER:
1856 case OP_FILENO:
1857 case OP_EOF:
1858 case OP_TELL:
1859 case OP_GETSOCKNAME:
1860 case OP_GETPEERNAME:
1861 case OP_READLINK:
1862 case OP_TELLDIR:
1863 case OP_GETPPID:
1864 case OP_GETPGRP:
1865 case OP_GETPRIORITY:
1866 case OP_TIME:
1867 case OP_TMS:
1868 case OP_LOCALTIME:
1869 case OP_GMTIME:
1870 case OP_GHBYNAME:
1871 case OP_GHBYADDR:
1872 case OP_GHOSTENT:
1873 case OP_GNBYNAME:
1874 case OP_GNBYADDR:
1875 case OP_GNETENT:
1876 case OP_GPBYNAME:
1877 case OP_GPBYNUMBER:
1878 case OP_GPROTOENT:
1879 case OP_GSBYNAME:
1880 case OP_GSBYPORT:
1881 case OP_GSERVENT:
1882 case OP_GPWNAM:
1883 case OP_GPWUID:
1884 case OP_GGRNAM:
1885 case OP_GGRGID:
1886 case OP_GETLOGIN:
1887 case OP_PROTOTYPE:
1888 case OP_RUNCV:
1889 func_ops:
9e209402
FC		 1890 useless = OP_DESC(o);
1891 break;
1892
1893 case OP_GVSV:
1894 case OP_PADSV:
1895 case OP_PADAV:
1896 case OP_PADHV:
1897 case OP_PADANY:
1898 case OP_AELEM:
1899 case OP_AELEMFAST:
1900 case OP_AELEMFAST_LEX:
1901 case OP_ASLICE:
1902 case OP_HELEM:
1903 case OP_HSLICE:
26f0e7d5 1904 if (!(o->op_private & (OPpLVAL_INTRO|OPpOUR_INTRO)))
ea5519d6 1905 /* Otherwise it's "Useless use of grep iterator" */
3c3f8cd6 1906 useless = OP_DESC(o);
ea5519d6 1907 break;
26f0e7d5
TC		 1908
1909 case OP_SPLIT:
1910 kid = cLISTOPo->op_first;
1911 if (kid && kid->op_type == OP_PUSHRE
1912 && !kid->op_targ
1913 && !(o->op_flags & OPf_STACKED)
75068674 1914#ifdef USE_ITHREADS
26f0e7d5 1915 && !((PMOP*)kid)->op_pmreplrootu.op_pmtargetoff
75068674 1916#else
26f0e7d5 1917 && !((PMOP*)kid)->op_pmreplrootu.op_pmtargetgv
75068674 1918#endif
26f0e7d5
TC		 1919 )
1920 useless = OP_DESC(o);
1921 break;
1922
1923 case OP_NOT:
1924 kid = cUNOPo->op_first;
1925 if (kid->op_type != OP_MATCH && kid->op_type != OP_SUBST &&
1926 kid->op_type != OP_TRANS && kid->op_type != OP_TRANSR) {
1927 goto func_ops;
1928 }
1929 useless = "negative pattern binding (!~)";
1930 break;
1931
1932 case OP_SUBST:
1933 if (cPMOPo->op_pmflags & PMf_NONDESTRUCT)
1934 useless = "non-destructive substitution (s///r)";
1935 break;
1936
1937 case OP_TRANSR:
1938 useless = "non-destructive transliteration (tr///r)";
1939 break;
1940
1941 case OP_RV2GV:
1942 case OP_RV2SV:
1943 case OP_RV2AV:
1944 case OP_RV2HV:
1945 if (!(o->op_private & (OPpLVAL_INTRO|OPpOUR_INTRO)) &&
e6dae479 1946 (!OpHAS_SIBLING(o) || OpSIBLING(o)->op_type != OP_READLINE))
26f0e7d5
TC		 1947 useless = "a variable";
1948 break;
1949
1950 case OP_CONST:
1951 sv = cSVOPo_sv;
1952 if (cSVOPo->op_private & OPpCONST_STRICT)
1953 no_bareword_allowed(o);
1954 else {
1955 if (ckWARN(WARN_VOID)) {
1956 NV nv;
1957 /* don't warn on optimised away booleans, eg
1958 * use constant Foo, 5; Foo || print; */
1959 if (cSVOPo->op_private & OPpCONST_SHORTCIRCUIT)
1960 useless = NULL;
1961 /* the constants 0 and 1 are permitted as they are
1962 conventionally used as dummies in constructs like
1963 1 while some_condition_with_side_effects; */
1964 else if (SvNIOK(sv) && ((nv = SvNV(sv)) == 0.0 || nv == 1.0))
1965 useless = NULL;
1966 else if (SvPOK(sv)) {
1967 SV * const dsv = newSVpvs("");
1968 useless_sv
1969 = Perl_newSVpvf(aTHX_
1970 "a constant (%s)",
1971 pv_pretty(dsv, SvPVX_const(sv),
1972 SvCUR(sv), 32, NULL, NULL,
1973 PERL_PV_PRETTY_DUMP
1974 | PERL_PV_ESCAPE_NOCLEAR
1975 | PERL_PV_ESCAPE_UNI_DETECT));
1976 SvREFCNT_dec_NN(dsv);
1977 }
1978 else if (SvOK(sv)) {
1979 useless_sv = Perl_newSVpvf(aTHX_ "a constant (%"SVf")", SVfARG(sv));
1980 }
1981 else
1982 useless = "a constant (undef)";
1983 }
1984 }
1985 op_null(o); /* don't execute or even remember it */
1986 break;
79072805 1987
26f0e7d5 1988 case OP_POSTINC:
b9a07097 1989 OpTYPE_set(o, OP_PREINC); /* pre-increment is faster */
26f0e7d5 1990 break;
79072805 1991
26f0e7d5 1992 case OP_POSTDEC:
b9a07097 1993 OpTYPE_set(o, OP_PREDEC); /* pre-decrement is faster */
26f0e7d5 1994 break;
79072805 1995
26f0e7d5 1996 case OP_I_POSTINC:
b9a07097 1997 OpTYPE_set(o, OP_I_PREINC); /* pre-increment is faster */
26f0e7d5 1998 break;
79072805 1999
26f0e7d5 2000 case OP_I_POSTDEC:
b9a07097 2001 OpTYPE_set(o, OP_I_PREDEC); /* pre-decrement is faster */
26f0e7d5 2002 break;
679d6c4e 2003
26f0e7d5
TC		 2004 case OP_SASSIGN: {
2005 OP *rv2gv;
2006 UNOP *refgen, *rv2cv;
2007 LISTOP *exlist;
679d6c4e 2008
26f0e7d5
TC		 2009 if ((o->op_private & ~OPpASSIGN_BACKWARDS) != 2)
2010 break;
f2f8fd84 2011
26f0e7d5
TC		 2012 rv2gv = ((BINOP *)o)->op_last;
2013 if (!rv2gv || rv2gv->op_type != OP_RV2GV)
2014 break;
f2f8fd84 2015
26f0e7d5 2016 refgen = (UNOP *)((BINOP *)o)->op_first;
f2f8fd84 2017
26f0e7d5
TC		 2018 if (!refgen || (refgen->op_type != OP_REFGEN
2019 && refgen->op_type != OP_SREFGEN))
2020 break;
f2f8fd84 2021
26f0e7d5
TC		 2022 exlist = (LISTOP *)refgen->op_first;
2023 if (!exlist || exlist->op_type != OP_NULL
2024 || exlist->op_targ != OP_LIST)
2025 break;
f2f8fd84 2026
26f0e7d5
TC		 2027 if (exlist->op_first->op_type != OP_PUSHMARK
2028 && exlist->op_first != exlist->op_last)
2029 break;
f2f8fd84 2030
26f0e7d5 2031 rv2cv = (UNOP*)exlist->op_last;
f2f8fd84 2032
26f0e7d5
TC		 2033 if (rv2cv->op_type != OP_RV2CV)
2034 break;
f2f8fd84 2035
26f0e7d5
TC		 2036 assert ((rv2gv->op_private & OPpDONT_INIT_GV) == 0);
2037 assert ((o->op_private & OPpASSIGN_CV_TO_GV) == 0);
2038 assert ((rv2cv->op_private & OPpMAY_RETURN_CONSTANT) == 0);
f2f8fd84 2039
26f0e7d5
TC		 2040 o->op_private |= OPpASSIGN_CV_TO_GV;
2041 rv2gv->op_private |= OPpDONT_INIT_GV;
2042 rv2cv->op_private |= OPpMAY_RETURN_CONSTANT;
f2f8fd84 2043
26f0e7d5
TC		 2044 break;
2045 }
540dd770 2046
26f0e7d5
TC		 2047 case OP_AASSIGN: {
2048 inplace_aassign(o);
2049 break;
2050 }
edbe35ea 2051
26f0e7d5
TC		 2052 case OP_OR:
2053 case OP_AND:
2054 kid = cLOGOPo->op_first;
2055 if (kid->op_type == OP_NOT
2056 && (kid->op_flags & OPf_KIDS)) {
2057 if (o->op_type == OP_AND) {
b9a07097 2058 OpTYPE_set(o, OP_OR);
26f0e7d5 2059 } else {
b9a07097 2060 OpTYPE_set(o, OP_AND);
26f0e7d5
TC		 2061 }
2062 op_null(kid);
2063 }
2064 /* FALLTHROUGH */
5aabfad6 2065
26f0e7d5
TC		 2066 case OP_DOR:
2067 case OP_COND_EXPR:
2068 case OP_ENTERGIVEN:
2069 case OP_ENTERWHEN:
e6dae479 2070 for (kid = OpSIBLING(cUNOPo->op_first); kid; kid = OpSIBLING(kid))
26f0e7d5
TC		 2071 if (!(kid->op_flags & OPf_KIDS))
2072 scalarvoid(kid);
2073 else
2074 DEFER_OP(kid);
aa9d1253 2075 break;
095b19d1 2076
26f0e7d5
TC		 2077 case OP_NULL:
2078 if (o->op_flags & OPf_STACKED)
2079 break;
2080 /* FALLTHROUGH */
2081 case OP_NEXTSTATE:
2082 case OP_DBSTATE:
2083 case OP_ENTERTRY:
2084 case OP_ENTER:
2085 if (!(o->op_flags & OPf_KIDS))
2086 break;
2087 /* FALLTHROUGH */
2088 case OP_SCOPE:
2089 case OP_LEAVE:
2090 case OP_LEAVETRY:
2091 case OP_LEAVELOOP:
2092 case OP_LINESEQ:
2093 case OP_LEAVEGIVEN:
2094 case OP_LEAVEWHEN:
2095 kids:
e6dae479 2096 for (kid = cLISTOPo->op_first; kid; kid = OpSIBLING(kid))
26f0e7d5
TC		 2097 if (!(kid->op_flags & OPf_KIDS))
2098 scalarvoid(kid);
2099 else
2100 DEFER_OP(kid);
2101 break;
2102 case OP_LIST:
2103 /* If the first kid after pushmark is something that the padrange
2104 optimisation would reject, then null the list and the pushmark.
2105 */
2106 if ((kid = cLISTOPo->op_first)->op_type == OP_PUSHMARK
e6dae479 2107 && ( !(kid = OpSIBLING(kid))
26f0e7d5
TC		 2108 || ( kid->op_type != OP_PADSV
2109 && kid->op_type != OP_PADAV
2110 && kid->op_type != OP_PADHV)
2111 || kid->op_private & ~OPpLVAL_INTRO
e6dae479 2112 || !(kid = OpSIBLING(kid))
26f0e7d5
TC		 2113 || ( kid->op_type != OP_PADSV
2114 && kid->op_type != OP_PADAV
2115 && kid->op_type != OP_PADHV)
2116 || kid->op_private & ~OPpLVAL_INTRO)
2117 ) {
2118 op_null(cUNOPo->op_first); /* NULL the pushmark */
2119 op_null(o); /* NULL the list */
2120 }
2121 goto kids;
2122 case OP_ENTEREVAL:
2123 scalarkids(o);
2124 break;
2125 case OP_SCALAR:
2126 scalar(o);
2127 break;
2128 }
2129
2130 if (useless_sv) {
2131 /* mortalise it, in case warnings are fatal. */
2132 Perl_ck_warner(aTHX_ packWARN(WARN_VOID),
2133 "Useless use of %"SVf" in void context",
2134 SVfARG(sv_2mortal(useless_sv)));
2135 }
2136 else if (useless) {
3c3f8cd6
AB		 2137 Perl_ck_warner(aTHX_ packWARN(WARN_VOID),
2138 "Useless use of %s in void context",
2139 useless);
26f0e7d5 2140 }
aa9d1253
TC		 2141 } while ( (o = POP_DEFERRED_OP()) );
2142
2143 Safefree(defer_stack);
2144
2145 return arg;
79072805
LW		 2146}
2147
1f676739 2148static OP *
412da003 2149S_listkids(pTHX_ OP *o)
79072805 2150{
11343788 2151 if (o && o->op_flags & OPf_KIDS) {
6867be6d 2152 OP *kid;
e6dae479 2153 for (kid = cLISTOPo->op_first; kid; kid = OpSIBLING(kid))
79072805
LW		 2154 list(kid);
2155 }
11343788 2156 return o;
79072805
LW		 2157}
2158
2159OP *
864dbfa3 2160Perl_list(pTHX_ OP *o)
79072805
LW		 2161{
2162 OP *kid;
2163
a0d0e21e 2164 /* assumes no premature commitment */
13765c85
DM		 2165 if (!o || (o->op_flags & OPf_WANT)
2166 || (PL_parser && PL_parser->error_count)
5dc0d613 2167 || o->op_type == OP_RETURN)
7e363e51 2168 {
11343788 2169 return o;
7e363e51 2170 }
79072805 2171
b162f9ea 2172 if ((o->op_private & OPpTARGET_MY)
7e363e51
GS		 2173 && (PL_opargs[o->op_type] & OA_TARGLEX))/* OPp share the meaning */
2174 {
b162f9ea 2175 return o; /* As if inside SASSIGN */
7e363e51 2176 }
1c846c1f 2177
5dc0d613 2178 o->op_flags = (o->op_flags & ~OPf_WANT) | OPf_WANT_LIST;
79072805 2179
11343788 2180 switch (o->op_type) {
79072805 2181 case OP_FLOP:
11343788 2182 list(cBINOPo->op_first);
79072805 2183 break;
c57eecc5
FC		 2184 case OP_REPEAT:
2185 if (o->op_private & OPpREPEAT_DOLIST
2186 && !(o->op_flags & OPf_STACKED))
2187 {
2188 list(cBINOPo->op_first);
2189 kid = cBINOPo->op_last;
2190 if (kid->op_type == OP_CONST && SvIOK(kSVOP_sv)
2191 && SvIVX(kSVOP_sv) == 1)
2192 {
2193 op_null(o); /* repeat */
2194 op_null(cUNOPx(cBINOPo->op_first)->op_first);/* pushmark */
2195 /* const (rhs): */
2196 op_free(op_sibling_splice(o, cBINOPo->op_first, 1, NULL));
2197 }
2198 }
2199 break;
79072805
LW		 2200 case OP_OR:
2201 case OP_AND:
2202 case OP_COND_EXPR:
e6dae479 2203 for (kid = OpSIBLING(cUNOPo->op_first); kid; kid = OpSIBLING(kid))
79072805
LW		 2204 list(kid);
2205 break;
2206 default:
2207 case OP_MATCH:
8782bef2 2208 case OP_QR:
79072805
LW		 2209 case OP_SUBST:
2210 case OP_NULL:
11343788 2211 if (!(o->op_flags & OPf_KIDS))
79072805 2212 break;
11343788
MB		 2213 if (!o->op_next && cUNOPo->op_first->op_type == OP_FLOP) {
2214 list(cBINOPo->op_first);
2215 return gen_constant_list(o);
79072805 2216 }
6aa68307
FC		 2217 listkids(o);
2218 break;
79072805 2219 case OP_LIST:
11343788 2220 listkids(o);
6aa68307
FC		 2221 if (cLISTOPo->op_first->op_type == OP_PUSHMARK) {
2222 op_null(cUNOPo->op_first); /* NULL the pushmark */
2223 op_null(o); /* NULL the list */
2224 }
79072805
LW		 2225 break;
2226 case OP_LEAVE:
2227 case OP_LEAVETRY:
5dc0d613 2228 kid = cLISTOPo->op_first;
54310121 2229 list(kid);
e6dae479 2230 kid = OpSIBLING(kid);
25b991bf
VP		 2231 do_kids:
2232 while (kid) {
e6dae479 2233 OP *sib = OpSIBLING(kid);
c08f093b
VP		 2234 if (sib && kid->op_type != OP_LEAVEWHEN)
2235 scalarvoid(kid);
2236 else
54310121 2237 list(kid);
25b991bf 2238 kid = sib;
54310121 2239 }
11206fdd 2240 PL_curcop = &PL_compiling;
54310121 2241 break;
748a9306 2242 case OP_SCOPE:
79072805 2243 case OP_LINESEQ:
25b991bf
VP		 2244 kid = cLISTOPo->op_first;
2245 goto do_kids;
79072805 2246 }
11343788 2247 return o;
79072805
LW		 2248}
2249
1f676739 2250static OP *
2dd5337b 2251S_scalarseq(pTHX_ OP *o)
79072805 2252{
11343788 2253 if (o) {
1496a290
AL		 2254 const OPCODE type = o->op_type;
2255
2256 if (type == OP_LINESEQ || type == OP_SCOPE ||
2257 type == OP_LEAVE || type == OP_LEAVETRY)
463ee0b2 2258 {
b7bea5da
FC		 2259 OP *kid, *sib;
2260 for (kid = cLISTOPo->op_first; kid; kid = sib) {
e6dae479
FC		 2261 if ((sib = OpSIBLING(kid))
2262 && ( OpHAS_SIBLING(sib) || sib->op_type != OP_NULL
b7bea5da
FC		 2263 || ( sib->op_targ != OP_NEXTSTATE
2264 && sib->op_targ != OP_DBSTATE )))
2265 {
463ee0b2 2266 scalarvoid(kid);
ed6116ce 2267 }
463ee0b2 2268 }
3280af22 2269 PL_curcop = &PL_compiling;
79072805 2270 }
11343788 2271 o->op_flags &= ~OPf_PARENS;
3280af22 2272 if (PL_hints & HINT_BLOCK_SCOPE)
11343788 2273 o->op_flags |= OPf_PARENS;
79072805 2274 }
8990e307 2275 else
11343788
MB		 2276 o = newOP(OP_STUB, 0);
2277 return o;
79072805
LW		 2278}
2279
76e3520e 2280STATIC OP *
cea2e8a9 2281S_modkids(pTHX_ OP *o, I32 type)
79072805 2282{
11343788 2283 if (o && o->op_flags & OPf_KIDS) {
6867be6d 2284 OP *kid;
e6dae479 2285 for (kid = cLISTOPo->op_first; kid; kid = OpSIBLING(kid))
3ad73efd 2286 op_lvalue(kid, type);
79072805 2287 }
11343788 2288 return o;
79072805
LW		 2289}
2290
12ee5d32
DM		 2291
2292/* for a helem/hslice/kvslice, if its a fixed hash, croak on invalid
2293 * const fields. Also, convert CONST keys to HEK-in-SVs.
2294 * rop is the op that retrieves the hash;
2295 * key_op is the first key
2296 */
2297
2298void
fedf30e1 2299S_check_hash_fields_and_hekify(pTHX_ UNOP *rop, SVOP *key_op)
12ee5d32
DM		 2300{
2301 PADNAME *lexname;
2302 GV **fields;
2303 bool check_fields;
2304
2305 /* find the padsv corresponding to $lex->{} or @{$lex}{} */
2306 if (rop) {
2307 if (rop->op_first->op_type == OP_PADSV)
2308 /* @$hash{qw(keys here)} */
2309 rop = (UNOP*)rop->op_first;
2310 else {
2311 /* @{$hash}{qw(keys here)} */
2312 if (rop->op_first->op_type == OP_SCOPE
2313 && cLISTOPx(rop->op_first)->op_last->op_type == OP_PADSV)
2314 {
2315 rop = (UNOP*)cLISTOPx(rop->op_first)->op_last;
2316 }
2317 else
2318 rop = NULL;
2319 }
2320 }
2321
2322 lexname = NULL; /* just to silence compiler warnings */
2323 fields = NULL; /* just to silence compiler warnings */
2324
2325 check_fields =
2326 rop
2327 && (lexname = padnamelist_fetch(PL_comppad_name, rop->op_targ),
2328 SvPAD_TYPED(lexname))
2329 && (fields = (GV**)hv_fetchs(PadnameTYPE(lexname), "FIELDS", FALSE))
2330 && isGV(*fields) && GvHV(*fields);
2331
e6dae479 2332 for (; key_op; key_op = (SVOP*)OpSIBLING(key_op)) {
12ee5d32
DM		 2333 SV **svp, *sv;
2334 if (key_op->op_type != OP_CONST)
2335 continue;
2336 svp = cSVOPx_svp(key_op);
2337
2338 /* Make the CONST have a shared SV */
2339 if ( !SvIsCOW_shared_hash(sv = *svp)
2340 && SvTYPE(sv) < SVt_PVMG
2341 && SvOK(sv)
2342 && !SvROK(sv))
2343 {
2344 SSize_t keylen;
2345 const char * const key = SvPV_const(sv, *(STRLEN*)&keylen);
2346 SV *nsv = newSVpvn_share(key, SvUTF8(sv) ? -keylen : keylen, 0);
2347 SvREFCNT_dec_NN(sv);
2348 *svp = nsv;
2349 }
2350
2351 if ( check_fields
2352 && !hv_fetch_ent(GvHV(*fields), *svp, FALSE, 0))
2353 {
2354 Perl_croak(aTHX_ "No such class field \"%"SVf"\" "
2355 "in variable %"PNf" of type %"HEKf,
2356 SVfARG(*svp), PNfARG(lexname),
2357 HEKfARG(HvNAME_HEK(PadnameTYPE(lexname))));
2358 }
2359 }
2360}
2361
2362
3ad73efd 2363/*
d164302a
GG		 2364=for apidoc finalize_optree
2365
72d33970
FC		 2366This function finalizes the optree. Should be called directly after
2367the complete optree is built. It does some additional
d164302a
GG		 2368checking which can't be done in the normal ck_xxx functions and makes
2369the tree thread-safe.
2370
2371=cut
2372*/
2373void
2374Perl_finalize_optree(pTHX_ OP* o)
2375{
2376 PERL_ARGS_ASSERT_FINALIZE_OPTREE;
2377
2378 ENTER;
2379 SAVEVPTR(PL_curcop);
2380
2381 finalize_op(o);
2382
2383 LEAVE;
2384}
2385
b46e009d 2386#ifdef USE_ITHREADS
2387/* Relocate sv to the pad for thread safety.
2388 * Despite being a "constant", the SV is written to,
2389 * for reference counts, sv_upgrade() etc. */
2390PERL_STATIC_INLINE void
2391S_op_relocate_sv(pTHX_ SV** svp, PADOFFSET* targp)
2392{
2393 PADOFFSET ix;
2394 PERL_ARGS_ASSERT_OP_RELOCATE_SV;
2395 if (!*svp) return;
2396 ix = pad_alloc(OP_CONST, SVf_READONLY);
2397 SvREFCNT_dec(PAD_SVl(ix));
2398 PAD_SETSV(ix, *svp);
2399 /* XXX I don't know how this isn't readonly already. */
2400 if (!SvIsCOW(PAD_SVl(ix))) SvREADONLY_on(PAD_SVl(ix));
2401 *svp = NULL;
2402 *targp = ix;
2403}
2404#endif
2405
2406
60dde6b2 2407STATIC void
d164302a
GG		 2408S_finalize_op(pTHX_ OP* o)
2409{
2410 PERL_ARGS_ASSERT_FINALIZE_OP;
2411
d164302a
GG		 2412
2413 switch (o->op_type) {
2414 case OP_NEXTSTATE:
2415 case OP_DBSTATE:
2416 PL_curcop = ((COP*)o); /* for warnings */
2417 break;
2418 case OP_EXEC:
e6dae479
FC		 2419 if (OpHAS_SIBLING(o)) {
2420 OP *sib = OpSIBLING(o);
1ed44841
DM		 2421 if (( sib->op_type == OP_NEXTSTATE || sib->op_type == OP_DBSTATE)
2422 && ckWARN(WARN_EXEC)
e6dae479 2423 && OpHAS_SIBLING(sib))
1ed44841 2424 {
e6dae479 2425 const OPCODE type = OpSIBLING(sib)->op_type;
d164302a
GG		 2426 if (type != OP_EXIT && type != OP_WARN && type != OP_DIE) {
2427 const line_t oldline = CopLINE(PL_curcop);
1ed44841 2428 CopLINE_set(PL_curcop, CopLINE((COP*)sib));
d164302a
GG		 2429 Perl_warner(aTHX_ packWARN(WARN_EXEC),
2430 "Statement unlikely to be reached");
2431 Perl_warner(aTHX_ packWARN(WARN_EXEC),
2432 "\t(Maybe you meant system() when you said exec()?)\n");
2433 CopLINE_set(PL_curcop, oldline);
2434 }
d164302a 2435 }
1ed44841 2436 }
d164302a
GG		 2437 break;
2438
2439 case OP_GV:
2440 if ((o->op_private & OPpEARLY_CV) && ckWARN(WARN_PROTOTYPE)) {
2441 GV * const gv = cGVOPo_gv;
2442 if (SvTYPE(gv) == SVt_PVGV && GvCV(gv) && SvPVX_const(GvCV(gv))) {
2443 /* XXX could check prototype here instead of just carping */
2444 SV * const sv = sv_newmortal();
2445 gv_efullname3(sv, gv, NULL);
2446 Perl_warner(aTHX_ packWARN(WARN_PROTOTYPE),
2447 "%"SVf"() called too early to check prototype",
2448 SVfARG(sv));
2449 }
2450 }
2451 break;
2452
2453 case OP_CONST:
eb796c7f
GG		 2454 if (cSVOPo->op_private & OPpCONST_STRICT)
2455 no_bareword_allowed(o);
2456 /* FALLTHROUGH */
d164302a
GG		 2457#ifdef USE_ITHREADS
2458 case OP_HINTSEVAL:
b46e009d 2459 op_relocate_sv(&cSVOPo->op_sv, &o->op_targ);
2460#endif
2461 break;
2462
2463#ifdef USE_ITHREADS
2464 /* Relocate all the METHOP's SVs to the pad for thread safety. */
d164302a 2465 case OP_METHOD_NAMED:
7d6c333c 2466 case OP_METHOD_SUPER:
810bd8b7 2467 case OP_METHOD_REDIR:
2468 case OP_METHOD_REDIR_SUPER:
b46e009d 2469 op_relocate_sv(&cMETHOPx(o)->op_u.op_meth_sv, &o->op_targ);
2470 break;
d164302a 2471#endif
d164302a
GG		 2472
2473 case OP_HELEM: {
2474 UNOP *rop;
565e6f7e
FC		 2475 SVOP *key_op;
2476 OP *kid;
d164302a 2477
565e6f7e 2478 if ((key_op = cSVOPx(((BINOP*)o)->op_last))->op_type != OP_CONST)
d164302a
GG		 2479 break;
2480
2481 rop = (UNOP*)((BINOP*)o)->op_first;
e6307ed0 2482
565e6f7e 2483 goto check_keys;
d164302a 2484
565e6f7e 2485 case OP_HSLICE:
429a2555 2486 S_scalar_slice_warning(aTHX_ o);
c67159e1 2487 /* FALLTHROUGH */
429a2555 2488
c5f75dba 2489 case OP_KVHSLICE:
e6dae479 2490 kid = OpSIBLING(cLISTOPo->op_first);
71323522 2491 if (/* I bet there's always a pushmark... */
7d3c8a68
S		 2492 OP_TYPE_ISNT_AND_WASNT_NN(kid, OP_LIST)
2493 && OP_TYPE_ISNT_NN(kid, OP_CONST))
2494 {
d164302a 2495 break;
7d3c8a68 2496 }
565e6f7e
FC		 2497
2498 key_op = (SVOP*)(kid->op_type == OP_CONST
2499 ? kid
e6dae479 2500 : OpSIBLING(kLISTOP->op_first));
565e6f7e
FC		 2501
2502 rop = (UNOP*)((LISTOP*)o)->op_last;
2503
2504 check_keys:
12ee5d32
DM		 2505 if (o->op_private & OPpLVAL_INTRO || rop->op_type != OP_RV2HV)
2506 rop = NULL;
fedf30e1 2507 S_check_hash_fields_and_hekify(aTHX_ rop, key_op);
d164302a
GG		 2508 break;
2509 }
429a2555
FC		 2510 case OP_ASLICE:
2511 S_scalar_slice_warning(aTHX_ o);
2512 break;
a7fd8ef6 2513
d164302a
GG		 2514 case OP_SUBST: {
2515 if (cPMOPo->op_pmreplrootu.op_pmreplroot)
2516 finalize_op(cPMOPo->op_pmreplrootu.op_pmreplroot);
2517 break;
2518 }
2519 default:
2520 break;
2521 }
2522
2523 if (o->op_flags & OPf_KIDS) {
2524 OP *kid;
c4b20975
DM		 2525
2526#ifdef DEBUGGING
20220689 2527 /* check that op_last points to the last sibling, and that
86cd3a13
DM		 2528 * the last op_sibling/op_sibparent field points back to the
2529 * parent, and that the only ops with KIDS are those which are
2530 * entitled to them */
c4b20975
DM		 2531 U32 type = o->op_type;
2532 U32 family;
20220689 2533 bool has_last;
c4b20975
DM		 2534
2535 if (type == OP_NULL) {
2536 type = o->op_targ;
2537 /* ck_glob creates a null UNOP with ex-type GLOB
2538 * (which is a list op. So pretend it wasn't a listop */
2539 if (type == OP_GLOB)
2540 type = OP_NULL;
2541 }
2542 family = PL_opargs[type] & OA_CLASS_MASK;
2543
20220689
DM		 2544 has_last = ( family == OA_BINOP
2545 || family == OA_LISTOP
2546 || family == OA_PMOP
2547 || family == OA_LOOP
2548 );
2549 assert( has_last /* has op_first and op_last, or ...
2550 ... has (or may have) op_first: */
2551 || family == OA_UNOP
2f7c6295 2552 || family == OA_UNOP_AUX
20220689
DM		 2553 || family == OA_LOGOP
2554 || family == OA_BASEOP_OR_UNOP
2555 || family == OA_FILESTATOP
2556 || family == OA_LOOPEXOP
b46e009d 2557 || family == OA_METHOP
20220689
DM		 2558 /* I don't know why SASSIGN is tagged as OA_BASEOP - DAPM */
2559 || type == OP_SASSIGN
2560 || type == OP_CUSTOM
2561 || type == OP_NULL /* new_logop does this */
2562 );
20220689 2563
e6dae479 2564 for (kid = cUNOPo->op_first; kid; kid = OpSIBLING(kid)) {
29e61fd9 2565# ifdef PERL_OP_PARENT
e6dae479 2566 if (!OpHAS_SIBLING(kid)) {
20220689 2567 if (has_last)
29e61fd9 2568 assert(kid == cLISTOPo->op_last);
86cd3a13 2569 assert(kid->op_sibparent == o);
20220689 2570 }
29e61fd9 2571# else
93059c1a
DM		 2572 if (has_last && !OpHAS_SIBLING(kid))
2573 assert(kid == cLISTOPo->op_last);
20220689 2574# endif
c4b20975
DM		 2575 }
2576#endif
2577
e6dae479 2578 for (kid = cUNOPo->op_first; kid; kid = OpSIBLING(kid))
d164302a
GG		 2579 finalize_op(kid);
2580 }
2581}
2582
2583/*
3ad73efd
Z		 2584=for apidoc Amx|OP *|op_lvalue|OP *o|I32 type
2585
2586Propagate lvalue ("modifiable") context to an op and its children.
2d7f6611 2587C<type> represents the context type, roughly based on the type of op that
3ad73efd
Z		 2588would do the modifying, although C<local()> is represented by OP_NULL,
2589because it has no op type of its own (it is signalled by a flag on
001c3c51
FC		 2590the lvalue op).
2591
2592This function detects things that can't be modified, such as C<$x+1>, and
72d33970 2593generates errors for them. For example, C<$x+1 = 2> would cause it to be
001c3c51
FC		 2594called with an op of type OP_ADD and a C<type> argument of OP_SASSIGN.
2595
2596It also flags things that need to behave specially in an lvalue context,
2597such as C<$$x = 5> which might have to vivify a reference in C<$x>.
3ad73efd
Z		 2598
2599=cut
2600*/
ddeae0f1 2601
03414f05
FC		 2602static void
2603S_mark_padname_lvalue(pTHX_ PADNAME *pn)
2604{
2605 CV *cv = PL_compcv;
2606 PadnameLVALUE_on(pn);
2607 while (PadnameOUTER(pn) && PARENT_PAD_INDEX(pn)) {
2608 cv = CvOUTSIDE(cv);
2609 assert(cv);
2610 assert(CvPADLIST(cv));
2611 pn =
2612 PadlistNAMESARRAY(CvPADLIST(cv))[PARENT_PAD_INDEX(pn)];
2613 assert(PadnameLEN(pn));
2614 PadnameLVALUE_on(pn);
2615 }
2616}
2617
375879aa
FC		 2618static bool
2619S_vivifies(const OPCODE type)
2620{
2621 switch(type) {
2622 case OP_RV2AV: case OP_ASLICE:
2623 case OP_RV2HV: case OP_KVASLICE:
2624 case OP_RV2SV: case OP_HSLICE:
2625 case OP_AELEMFAST: case OP_KVHSLICE:
2626 case OP_HELEM:
2627 case OP_AELEM:
2628 return 1;
2629 }
2630 return 0;
2631}
2632
7664512e 2633static void
63702de8 2634S_lvref(pTHX_ OP *o, I32 type)
7664512e 2635{
727d2dc6 2636 dVAR;
7664512e
FC		 2637 OP *kid;
2638 switch (o->op_type) {
2639 case OP_COND_EXPR:
e6dae479
FC		 2640 for (kid = OpSIBLING(cUNOPo->op_first); kid;
2641 kid = OpSIBLING(kid))
63702de8 2642 S_lvref(aTHX_ kid, type);
7664512e
FC		 2643 /* FALLTHROUGH */
2644 case OP_PUSHMARK:
2645 return;
2646 case OP_RV2AV:
2647 if (cUNOPo->op_first->op_type != OP_GV) goto badref;
2648 o->op_flags |= OPf_STACKED;
2649 if (o->op_flags & OPf_PARENS) {
2650 if (o->op_private & OPpLVAL_INTRO) {
7664512e
FC		 2651 yyerror(Perl_form(aTHX_ "Can't modify reference to "
2652 "localized parenthesized array in list assignment"));
2653 return;
2654 }
2655 slurpy:
b9a07097 2656 OpTYPE_set(o, OP_LVAVREF);
7664512e
FC		 2657 o->op_private &= OPpLVAL_INTRO|OPpPAD_STATE;
2658 o->op_flags |= OPf_MOD|OPf_REF;
2659 return;
2660 }
2661 o->op_private |= OPpLVREF_AV;
2662 goto checkgv;
408e9044 2663 case OP_RV2CV:
19abb1ea
FC		 2664 kid = cUNOPo->op_first;
2665 if (kid->op_type == OP_NULL)
cb748240 2666 kid = cUNOPx(OpSIBLING(kUNOP->op_first))
408e9044
FC		 2667 ->op_first;
2668 o->op_private = OPpLVREF_CV;
2669 if (kid->op_type == OP_GV)
2670 o->op_flags |= OPf_STACKED;
2671 else if (kid->op_type == OP_PADCV) {
2672 o->op_targ = kid->op_targ;
2673 kid->op_targ = 0;
2674 op_free(cUNOPo->op_first);
2675 cUNOPo->op_first = NULL;
2676 o->op_flags &=~ OPf_KIDS;
2677 }
2678 else goto badref;
2679 break;
7664512e
FC		 2680 case OP_RV2HV:
2681 if (o->op_flags & OPf_PARENS) {
2682 parenhash:
7664512e
FC		 2683 yyerror(Perl_form(aTHX_ "Can't modify reference to "
2684 "parenthesized hash in list assignment"));
2685 return;
2686 }
2687 o->op_private |= OPpLVREF_HV;
2688 /* FALLTHROUGH */
2689 case OP_RV2SV:
2690 checkgv:
2691 if (cUNOPo->op_first->op_type != OP_GV) goto badref;
2692 o->op_flags |= OPf_STACKED;
6f5dab3c
FC		 2693 break;
2694 case OP_PADHV:
2695 if (o->op_flags & OPf_PARENS) goto parenhash;
2696 o->op_private |= OPpLVREF_HV;
7664512e
FC		 2697 /* FALLTHROUGH */
2698 case OP_PADSV:
6f5dab3c 2699 PAD_COMPNAME_GEN_set(o->op_targ, PERL_INT_MAX);
7664512e
FC		 2700 break;
2701 case OP_PADAV:
6f5dab3c 2702 PAD_COMPNAME_GEN_set(o->op_targ, PERL_INT_MAX);
7664512e
FC		 2703 if (o->op_flags & OPf_PARENS) goto slurpy;
2704 o->op_private |= OPpLVREF_AV;
2705 break;
7664512e
FC		 2706 case OP_AELEM:
2707 case OP_HELEM:
2708 o->op_private |= OPpLVREF_ELEM;
2709 o->op_flags |= OPf_STACKED;
2710 break;
2711 case OP_ASLICE:
2712 case OP_HSLICE:
b9a07097 2713 OpTYPE_set(o, OP_LVREFSLICE);
7664512e
FC		 2714 o->op_private &= OPpLVAL_INTRO|OPpLVREF_ELEM;
2715 return;
2716 case OP_NULL:
2717 if (o->op_flags & OPf_SPECIAL) /* do BLOCK */
2718 goto badref;
2719 else if (!(o->op_flags & OPf_KIDS))
2720 return;
2721 if (o->op_targ != OP_LIST) {
63702de8 2722 S_lvref(aTHX_ cBINOPo->op_first, type);
7664512e
FC		 2723 return;
2724 }
2725 /* FALLTHROUGH */
2726 case OP_LIST:
e6dae479 2727 for (kid = cLISTOPo->op_first; kid; kid = OpSIBLING(kid)) {
7664512e 2728 assert((kid->op_flags & OPf_WANT) != OPf_WANT_VOID);
63702de8 2729 S_lvref(aTHX_ kid, type);
7664512e
FC		 2730 }
2731 return;
2732 case OP_STUB:
2733 if (o->op_flags & OPf_PARENS)
2734 return;
2735 /* FALLTHROUGH */
2736 default:
2737 badref:
cf6e1fa1 2738 /* diag_listed_as: Can't modify reference to %s in %s assignment */
63702de8 2739 yyerror(Perl_form(aTHX_ "Can't modify reference to %s in %s",
7664512e
FC		 2740 o->op_type == OP_NULL && o->op_flags & OPf_SPECIAL
2741 ? "do block"
63702de8
FC		 2742 : OP_DESC(o),
2743 PL_op_desc[type]));
7664512e 2744 }
b9a07097 2745 OpTYPE_set(o, OP_LVREF);
3ad7d304
FC		 2746 o->op_private &=
2747 OPpLVAL_INTRO|OPpLVREF_ELEM|OPpLVREF_TYPE|OPpPAD_STATE;
d39c26a6
FC		 2748 if (type == OP_ENTERLOOP)
2749 o->op_private |= OPpLVREF_ITER;
7664512e
FC		 2750}
2751
79072805 2752OP *
d3d7d28f 2753Perl_op_lvalue_flags(pTHX_ OP *o, I32 type, U32 flags)
79072805 2754{
27da23d5 2755 dVAR;
79072805 2756 OP *kid;
ddeae0f1
DM		 2757 /* -1 = error on localize, 0 = ignore localize, 1 = ok to localize */
2758 int localize = -1;
79072805 2759
13765c85 2760 if (!o || (PL_parser && PL_parser->error_count))
11343788 2761 return o;
79072805 2762
b162f9ea 2763 if ((o->op_private & OPpTARGET_MY)
7e363e51
GS		 2764 && (PL_opargs[o->op_type] & OA_TARGLEX))/* OPp share the meaning */
2765 {
b162f9ea 2766 return o;
7e363e51 2767 }
1c846c1f 2768
5c906035
GG		 2769 assert( (o->op_flags & OPf_WANT) != OPf_WANT_VOID );
2770
69974ce6
FC		 2771 if (type == OP_PRTF || type == OP_SPRINTF) type = OP_ENTERSUB;
2772
11343788 2773 switch (o->op_type) {
68dc0745 2774 case OP_UNDEF:
3280af22 2775 PL_modcount++;
5dc0d613 2776 return o;
5f05dabc 2777 case OP_STUB:
b5bbe64a 2778 if ((o->op_flags & OPf_PARENS))
5f05dabc 2779 break;
2780 goto nomod;
a0d0e21e 2781 case OP_ENTERSUB:
f79aa60b 2782 if ((type == OP_UNDEF || type == OP_REFGEN || type == OP_LOCK) &&
11343788 2783 !(o->op_flags & OPf_STACKED)) {
b9a07097 2784 OpTYPE_set(o, OP_RV2CV); /* entersub => rv2cv */
11343788 2785 assert(cUNOPo->op_first->op_type == OP_NULL);
93c66552 2786 op_null(((LISTOP*)cUNOPo->op_first)->op_first);/* disable pushmark */
79072805
LW		 2787 break;
2788 }
cd06dffe 2789 else { /* lvalue subroutine call */
9411a3c7 2790 o->op_private |= OPpLVAL_INTRO;
e6438c1a 2791 PL_modcount = RETURN_UNLIMITED_NUMBER;
9411a3c7
FC		 2792 if (type == OP_GREPSTART || type == OP_ENTERSUB
2793 || type == OP_REFGEN || type == OP_LEAVESUBLV) {
d0887bf3 2794 /* Potential lvalue context: */
cd06dffe
GS		 2795 o->op_private |= OPpENTERSUB_INARGS;
2796 break;
2797 }
2798 else { /* Compile-time error message: */
2799 OP *kid = cUNOPo->op_first;
2800 CV *cv;
2eaf799e 2801 GV *gv;
cd06dffe 2802
3ea285d1
AL		 2803 if (kid->op_type != OP_PUSHMARK) {
2804 if (kid->op_type != OP_NULL || kid->op_targ != OP_LIST)
2805 Perl_croak(aTHX_
2806 "panic: unexpected lvalue entersub "
2807 "args: type/targ %ld:%"UVuf,
2808 (long)kid->op_type, (UV)kid->op_targ);
2809 kid = kLISTOP->op_first;
2810 }
e6dae479
FC		 2811 while (OpHAS_SIBLING(kid))
2812 kid = OpSIBLING(kid);
cd06dffe 2813 if (!(kid->op_type == OP_NULL && kid->op_targ == OP_RV2CV)) {
cd06dffe
GS		 2814 break; /* Postpone until runtime */
2815 }
b2ffa427 2816
cd06dffe
GS		 2817 kid = kUNOP->op_first;
2818 if (kid->op_type == OP_NULL && kid->op_targ == OP_RV2SV)
2819 kid = kUNOP->op_first;
b2ffa427 2820 if (kid->op_type == OP_NULL)
cd06dffe
GS		 2821 Perl_croak(aTHX_
2822 "Unexpected constant lvalue entersub "
55140b79 2823 "entry via type/targ %ld:%"UVuf,
3d811634 2824 (long)kid->op_type, (UV)kid->op_targ);
cd06dffe 2825 if (kid->op_type != OP_GV) {
cd06dffe
GS		 2826 break;
2827 }
b2ffa427 2828
2eaf799e
FC		 2829 gv = kGVOP_gv;
2830 cv = isGV(gv)
2831 ? GvCV(gv)
2832 : SvROK(gv) && SvTYPE(SvRV(gv)) == SVt_PVCV
2833 ? MUTABLE_CV(SvRV(gv))
2834 : NULL;
1c846c1f 2835 if (!cv)
da1dff94 2836 break;
cd06dffe
GS		 2837 if (CvLVALUE(cv))
2838 break;
2839 }
2840 }
924ba076 2841 /* FALLTHROUGH */
79072805 2842 default:
a0d0e21e 2843 nomod:
f5d552b4 2844 if (flags & OP_LVALUE_NO_CROAK) return NULL;
6fbb66d6 2845 /* grep, foreach, subcalls, refgen */
145b2bbb
FC		 2846 if (type == OP_GREPSTART || type == OP_ENTERSUB
2847 || type == OP_REFGEN || type == OP_LEAVESUBLV)
a0d0e21e 2848 break;
cea2e8a9 2849 yyerror(Perl_form(aTHX_ "Can't modify %s in %s",
638bc118 2850 (o->op_type == OP_NULL && (o->op_flags & OPf_SPECIAL)
cd06dffe
GS		 2851 ? "do block"
2852 : (o->op_type == OP_ENTERSUB
2853 ? "non-lvalue subroutine call"
53e06cf0 2854 : OP_DESC(o))),
22c35a8c 2855 type ? PL_op_desc[type] : "local"));
11343788 2856 return o;
79072805 2857
a0d0e21e
LW		 2858 case OP_PREINC:
2859 case OP_PREDEC:
2860 case OP_POW:
2861 case OP_MULTIPLY:
2862 case OP_DIVIDE:
2863 case OP_MODULO:
a0d0e21e
LW		 2864 case OP_ADD:
2865 case OP_SUBTRACT:
2866 case OP_CONCAT:
2867 case OP_LEFT_SHIFT:
2868 case OP_RIGHT_SHIFT:
2869 case OP_BIT_AND:
2870 case OP_BIT_XOR:
2871 case OP_BIT_OR:
2872 case OP_I_MULTIPLY:
2873 case OP_I_DIVIDE:
2874 case OP_I_MODULO:
2875 case OP_I_ADD:
2876 case OP_I_SUBTRACT:
11343788 2877 if (!(o->op_flags & OPf_STACKED))
a0d0e21e 2878 goto nomod;
3280af22 2879 PL_modcount++;
a0d0e21e 2880 break;
b2ffa427 2881
82209a5d
FC		 2882 case OP_REPEAT:
2883 if (o->op_flags & OPf_STACKED) {
2884 PL_modcount++;
2885 break;
2886 }
ff781254 2887 if (!(o->op_private & OPpREPEAT_DOLIST))
82209a5d
FC		 2888 goto nomod;
2889 else {
2890 const I32 mods = PL_modcount;
ff781254
FC		 2891 modkids(cBINOPo->op_first, type);
2892 if (type != OP_AASSIGN)
2893 goto nomod;
5e462669 2894 kid = cBINOPo->op_last;
82209a5d 2895 if (kid->op_type == OP_CONST && SvIOK(kSVOP_sv)) {
565e104c 2896 const IV iv = SvIV(kSVOP_sv);
82209a5d
FC		 2897 if (PL_modcount != RETURN_UNLIMITED_NUMBER)
2898 PL_modcount =
2899 mods + (PL_modcount - mods) * (iv < 0 ? 0 : iv);
2900 }
2901 else
2902 PL_modcount = RETURN_UNLIMITED_NUMBER;
2903 }
2904 break;
2905
79072805 2906 case OP_COND_EXPR:
ddeae0f1 2907 localize = 1;
e6dae479 2908 for (kid = OpSIBLING(cUNOPo->op_first); kid; kid = OpSIBLING(kid))
3ad73efd 2909 op_lvalue(kid, type);
79072805
LW		 2910 break;
2911
2912 case OP_RV2AV:
2913 case OP_RV2HV:
11343788 2914 if (type == OP_REFGEN && o->op_flags & OPf_PARENS) {
e6438c1a 2915 PL_modcount = RETURN_UNLIMITED_NUMBER;
11343788 2916 return o; /* Treat \(@foo) like ordinary list. */
748a9306 2917 }
924ba076 2918 /* FALLTHROUGH */
79072805 2919 case OP_RV2GV:
5dc0d613 2920 if (scalar_mod_type(o, type))
3fe9a6f1 2921 goto nomod;
11343788 2922 ref(cUNOPo->op_first, o->op_type);
924ba076 2923 /* FALLTHROUGH */
79072805
LW		 2924 case OP_ASLICE:
2925 case OP_HSLICE:
ddeae0f1 2926 localize = 1;
924ba076 2927 /* FALLTHROUGH */
78f9721b 2928 case OP_AASSIGN:
32cbae3f
FC		 2929 /* Do not apply the lvsub flag for rv2[ah]v in scalar context. */
2930 if (type == OP_LEAVESUBLV && (
2931 (o->op_type != OP_RV2AV && o->op_type != OP_RV2HV)
2932 || (o->op_flags & OPf_WANT) != OPf_WANT_SCALAR
2933 ))
631dbaa2 2934 o->op_private |= OPpMAYBE_LVSUB;
924ba076 2935 /* FALLTHROUGH */
93a17b20
LW		 2936 case OP_NEXTSTATE:
2937 case OP_DBSTATE:
e6438c1a 2938 PL_modcount = RETURN_UNLIMITED_NUMBER;
79072805 2939 break;
5cae3edb 2940 case OP_KVHSLICE:
6dd3e0f2 2941 case OP_KVASLICE:
5cae3edb
RZ		 2942 if (type == OP_LEAVESUBLV)
2943 o->op_private |= OPpMAYBE_LVSUB;
2944 goto nomod;
28c5b5bc
RGS		 2945 case OP_AV2ARYLEN:
2946 PL_hints |= HINT_BLOCK_SCOPE;
2947 if (type == OP_LEAVESUBLV)
2948 o->op_private |= OPpMAYBE_LVSUB;
2949 PL_modcount++;
2950 break;
463ee0b2 2951 case OP_RV2SV:
aeea060c 2952 ref(cUNOPo->op_first, o->op_type);
ddeae0f1 2953 localize = 1;
924ba076 2954 /* FALLTHROUGH */
79072805 2955 case OP_GV:
3280af22 2956 PL_hints |= HINT_BLOCK_SCOPE;
924ba076 2957 /* FALLTHROUGH */
463ee0b2 2958 case OP_SASSIGN:
bf4b1e52
GS		 2959 case OP_ANDASSIGN:
2960 case OP_ORASSIGN:
c963b151 2961 case OP_DORASSIGN:
ddeae0f1
DM		 2962 PL_modcount++;
2963 break;
2964
8990e307 2965 case OP_AELEMFAST:
93bad3fd 2966 case OP_AELEMFAST_LEX:
6a077020 2967 localize = -1;
3280af22 2968 PL_modcount++;
8990e307
LW		 2969 break;
2970
748a9306
LW		 2971 case OP_PADAV:
2972 case OP_PADHV:
e6438c1a 2973 PL_modcount = RETURN_UNLIMITED_NUMBER;
5196be3e
MB		 2974 if (type == OP_REFGEN && o->op_flags & OPf_PARENS)
2975 return o; /* Treat \(@foo) like ordinary list. */
2976 if (scalar_mod_type(o, type))
3fe9a6f1 2977 goto nomod;
32cbae3f
FC		 2978 if ((o->op_flags & OPf_WANT) != OPf_WANT_SCALAR
2979 && type == OP_LEAVESUBLV)
78f9721b 2980 o->op_private |= OPpMAYBE_LVSUB;
924ba076 2981 /* FALLTHROUGH */
748a9306 2982 case OP_PADSV:
3280af22 2983 PL_modcount++;
ddeae0f1 2984 if (!type) /* local() */
ea9a9e77
FC		 2985 Perl_croak(aTHX_ "Can't localize lexical variable %"PNf,
2986 PNfARG(PAD_COMPNAME(o->op_targ)));
e4211fee
FC		 2987 if (!(o->op_private & OPpLVAL_INTRO)
2988 || ( type != OP_SASSIGN && type != OP_AASSIGN
2989 && PadnameIsSTATE(PAD_COMPNAME_SV(o->op_targ)) ))
03414f05 2990 S_mark_padname_lvalue(aTHX_ PAD_COMPNAME_SV(o->op_targ));
463ee0b2
LW		 2991 break;
2992
748a9306 2993 case OP_PUSHMARK:
ddeae0f1 2994 localize = 0;
748a9306 2995 break;
b2ffa427 2996
69969c6f 2997 case OP_KEYS:
fad4a2e4 2998 if (type != OP_SASSIGN && type != OP_LEAVESUBLV)
69969c6f 2999 goto nomod;
5d82c453
GA		 3000 goto lvalue_func;
3001 case OP_SUBSTR:
3002 if (o->op_private == 4) /* don't allow 4 arg substr as lvalue */
3003 goto nomod;
924ba076 3004 /* FALLTHROUGH */
a0d0e21e 3005 case OP_POS:
463ee0b2 3006 case OP_VEC:
fad4a2e4 3007 lvalue_func:
78f9721b
SM		 3008 if (type == OP_LEAVESUBLV)
3009 o->op_private |= OPpMAYBE_LVSUB;
11343788 3010 if (o->op_flags & OPf_KIDS)
e6dae479 3011 op_lvalue(OpSIBLING(cBINOPo->op_first), type);
463ee0b2 3012 break;
a0d0e21e 3013
463ee0b2
LW		 3014 case OP_AELEM:
3015 case OP_HELEM:
11343788 3016 ref(cBINOPo->op_first, o->op_type);
68dc0745 3017 if (type == OP_ENTERSUB &&
5dc0d613
MB		 3018 !(o->op_private & (OPpLVAL_INTRO | OPpDEREF)))
3019 o->op_private |= OPpLVAL_DEFER;
78f9721b
SM		 3020 if (type == OP_LEAVESUBLV)
3021 o->op_private |= OPpMAYBE_LVSUB;
ddeae0f1 3022 localize = 1;
3280af22 3023 PL_modcount++;
463ee0b2
LW		 3024 break;
3025
463ee0b2 3026 case OP_LEAVE:
a373464f 3027 case OP_LEAVELOOP:
2ec7f6f2 3028 o->op_private |= OPpLVALUE;
924ba076 3029 /* FALLTHROUGH */
2ec7f6f2 3030 case OP_SCOPE:
463ee0b2 3031 case OP_ENTER:
78f9721b 3032 case OP_LINESEQ:
ddeae0f1 3033 localize = 0;
11343788 3034 if (o->op_flags & OPf_KIDS)
3ad73efd 3035 op_lvalue(cLISTOPo->op_last, type);
a0d0e21e
LW		 3036 break;
3037
3038 case OP_NULL:
ddeae0f1 3039 localize = 0;
638bc118
GS		 3040 if (o->op_flags & OPf_SPECIAL) /* do BLOCK */
3041 goto nomod;
3042 else if (!(o->op_flags & OPf_KIDS))
463ee0b2 3043 break;
11343788 3044 if (o->op_targ != OP_LIST) {
3ad73efd 3045 op_lvalue(cBINOPo->op_first, type);
a0d0e21e
LW		 3046 break;
3047 }
924ba076 3048 /* FALLTHROUGH */
463ee0b2 3049 case OP_LIST:
ddeae0f1 3050 localize = 0;
e6dae479 3051 for (kid = cLISTOPo->op_first; kid; kid = OpSIBLING(kid))
5c906035
GG		 3052 /* elements might be in void context because the list is
3053 in scalar context or because they are attribute sub calls */
3054 if ( (kid->op_flags & OPf_WANT) != OPf_WANT_VOID )
3055 op_lvalue(kid, type);
463ee0b2 3056 break;
78f9721b 3057
1efec5ed
FC		 3058 case OP_COREARGS:
3059 return o;
2ec7f6f2
FC		 3060
3061 case OP_AND:
3062 case OP_OR:
375879aa
FC		 3063 if (type == OP_LEAVESUBLV
3064 || !S_vivifies(cLOGOPo->op_first->op_type))
3065 op_lvalue(cLOGOPo->op_first, type);
3066 if (type == OP_LEAVESUBLV
e6dae479
FC		 3067 || !S_vivifies(OpSIBLING(cLOGOPo->op_first)->op_type))
3068 op_lvalue(OpSIBLING(cLOGOPo->op_first), type);
2ec7f6f2 3069 goto nomod;
26a50d99
FC		 3070
3071 case OP_SREFGEN:
d39c26a6
FC		 3072 if (type != OP_AASSIGN && type != OP_SASSIGN
3073 && type != OP_ENTERLOOP)
3074 goto nomod;
7664512e 3075 /* Don’t bother applying lvalue context to the ex-list. */
26a50d99 3076 kid = cUNOPx(cUNOPo->op_first)->op_first;
e6dae479 3077 assert (!OpHAS_SIBLING(kid));
217e3565
FC		 3078 goto kid_2lvref;
3079 case OP_REFGEN:
3080 if (type != OP_AASSIGN) goto nomod;
7664512e
FC		 3081 kid = cUNOPo->op_first;
3082 kid_2lvref:
3083 {
3084 const U8 ec = PL_parser ? PL_parser->error_count : 0;
63702de8 3085 S_lvref(aTHX_ kid, type);
7664512e 3086 if (!PL_parser || PL_parser->error_count == ec) {
baabe3fb 3087 if (!FEATURE_REFALIASING_IS_ENABLED)
7664512e 3088 Perl_croak(aTHX_
baabe3fb 3089 "Experimental aliasing via reference not enabled");
7664512e 3090 Perl_ck_warner_d(aTHX_
baabe3fb
FC		 3091 packWARN(WARN_EXPERIMENTAL__REFALIASING),
3092 "Aliasing via reference is experimental");
7664512e
FC		 3093 }
3094 }
217e3565
FC		 3095 if (o->op_type == OP_REFGEN)
3096 op_null(cUNOPx(cUNOPo->op_first)->op_first); /* pushmark */
3097 op_null(o);
26a50d99 3098 return o;
e4e95921
FC		 3099
3100 case OP_SPLIT:
3101 kid = cLISTOPo->op_first;
3102 if (kid && kid->op_type == OP_PUSHRE &&
3103 ( kid->op_targ
3104 || o->op_flags & OPf_STACKED
3105#ifdef USE_ITHREADS
3106 || ((PMOP*)kid)->op_pmreplrootu.op_pmtargetoff
3107#else
3108 || ((PMOP*)kid)->op_pmreplrootu.op_pmtargetgv
3109#endif
3110 )) {
3111 /* This is actually @array = split. */
3112 PL_modcount = RETURN_UNLIMITED_NUMBER;
3113 break;
3114 }
3115 goto nomod;
569ddb4a
FC		 3116
3117 case OP_SCALAR:
3118 op_lvalue(cUNOPo->op_first, OP_ENTERSUB);
3119 goto nomod;
463ee0b2 3120 }
58d95175 3121
8be1be90
AMS		 3122 /* [20011101.069] File test operators interpret OPf_REF to mean that
3123 their argument is a filehandle; thus \stat(".") should not set
3124 it. AMS 20011102 */
3125 if (type == OP_REFGEN &&
ef69c8fc 3126 PL_check[o->op_type] == Perl_ck_ftst)
8be1be90
AMS		 3127 return o;
3128
3129 if (type != OP_LEAVESUBLV)
3130 o->op_flags |= OPf_MOD;
3131
3132 if (type == OP_AASSIGN || type == OP_SASSIGN)
3133 o->op_flags |= OPf_SPECIAL|OPf_REF;
ddeae0f1
DM		 3134 else if (!type) { /* local() */
3135 switch (localize) {
3136 case 1:
3137 o->op_private |= OPpLVAL_INTRO;
3138 o->op_flags &= ~OPf_SPECIAL;
3139 PL_hints |= HINT_BLOCK_SCOPE;
3140 break;
3141 case 0:
3142 break;
3143 case -1:
a2a5de95
NC		 3144 Perl_ck_warner(aTHX_ packWARN(WARN_SYNTAX),
3145 "Useless localization of %s", OP_DESC(o));
ddeae0f1 3146 }
463ee0b2 3147 }
8be1be90
AMS		 3148 else if (type != OP_GREPSTART && type != OP_ENTERSUB
3149 && type != OP_LEAVESUBLV)
3150 o->op_flags |= OPf_REF;
11343788 3151 return o;
463ee0b2
LW		 3152}
3153
864dbfa3 3154STATIC bool
5f66b61c 3155S_scalar_mod_type(const OP *o, I32 type)
3fe9a6f1 3156{
3157 switch (type) {
32a60974 3158 case OP_POS:
3fe9a6f1 3159 case OP_SASSIGN:
1efec5ed 3160 if (o && o->op_type == OP_RV2GV)
3fe9a6f1 3161 return FALSE;
924ba076 3162 /* FALLTHROUGH */
3fe9a6f1 3163 case OP_PREINC:
3164 case OP_PREDEC:
3165 case OP_POSTINC:
3166 case OP_POSTDEC:
3167 case OP_I_PREINC:
3168 case OP_I_PREDEC:
3169 case OP_I_POSTINC:
3170 case OP_I_POSTDEC:
3171 case OP_POW:
3172 case OP_MULTIPLY:
3173 case OP_DIVIDE:
3174 case OP_MODULO:
3175 case OP_REPEAT:
3176 case OP_ADD:
3177 case OP_SUBTRACT:
3178 case OP_I_MULTIPLY:
3179 case OP_I_DIVIDE:
3180 case OP_I_MODULO:
3181 case OP_I_ADD:
3182 case OP_I_SUBTRACT:
3183 case OP_LEFT_SHIFT:
3184 case OP_RIGHT_SHIFT:
3185 case OP_BIT_AND:
3186 case OP_BIT_XOR:
3187 case OP_BIT_OR:
3188 case OP_CONCAT:
3189 case OP_SUBST:
3190 case OP_TRANS:
bb16bae8 3191 case OP_TRANSR:
49e9fbe6
GS		 3192 case OP_READ:
3193 case OP_SYSREAD:
3194 case OP_RECV:
bf4b1e52
GS		 3195 case OP_ANDASSIGN:
3196 case OP_ORASSIGN:
410d09fe 3197 case OP_DORASSIGN:
3fe9a6f1 3198 return TRUE;
3199 default:
3200 return FALSE;
3201 }
3202}
3203
35cd451c 3204STATIC bool
5f66b61c 3205S_is_handle_constructor(const OP *o, I32 numargs)
35cd451c 3206{
7918f24d
NC		 3207 PERL_ARGS_ASSERT_IS_HANDLE_CONSTRUCTOR;
3208
35cd451c
GS		 3209 switch (o->op_type) {
3210 case OP_PIPE_OP:
3211 case OP_SOCKPAIR:
504618e9 3212 if (numargs == 2)
35cd451c 3213 return TRUE;
924ba076 3214 /* FALLTHROUGH */
35cd451c
GS		 3215 case OP_SYSOPEN:
3216 case OP_OPEN:
ded8aa31 3217 case OP_SELECT: /* XXX c.f. SelectSaver.pm */
35cd451c
GS		 3218 case OP_SOCKET:
3219 case OP_OPEN_DIR:
3220 case OP_ACCEPT:
504618e9 3221 if (numargs == 1)
35cd451c 3222 return TRUE;
5f66b61c 3223 /* FALLTHROUGH */
35cd451c
GS		 3224 default:
3225 return FALSE;
3226 }
3227}
3228
0d86688d
NC		 3229static OP *
3230S_refkids(pTHX_ OP *o, I32 type)
463ee0b2 3231{
11343788 3232 if (o && o->op_flags & OPf_KIDS) {
6867be6d 3233 OP *kid;
e6dae479 3234 for (kid = cLISTOPo->op_first; kid; kid = OpSIBLING(kid))
463ee0b2
LW		 3235 ref(kid, type);
3236 }
11343788 3237 return o;
463ee0b2
LW		 3238}
3239
3240OP *
e4c5ccf3 3241Perl_doref(pTHX_ OP *o, I32 type, bool set_op_ref)
463ee0b2 3242{
27da23d5 3243 dVAR;
463ee0b2 3244 OP *kid;
463ee0b2 3245
7918f24d
NC		 3246 PERL_ARGS_ASSERT_DOREF;
3247
3dc78631 3248 if (PL_parser && PL_parser->error_count)
11343788 3249 return o;
463ee0b2 3250
11343788 3251 switch (o->op_type) {
a0d0e21e 3252 case OP_ENTERSUB:
f4df43b5 3253 if ((type == OP_EXISTS || type == OP_DEFINED) &&
11343788 3254 !(o->op_flags & OPf_STACKED)) {
b9a07097 3255 OpTYPE_set(o, OP_RV2CV); /* entersub => rv2cv */
11343788 3256 assert(cUNOPo->op_first->op_type == OP_NULL);
93c66552 3257 op_null(((LISTOP*)cUNOPo->op_first)->op_first); /* disable pushmark */
11343788 3258 o->op_flags |= OPf_SPECIAL;
8990e307 3259 }
767eda44 3260 else if (type == OP_RV2SV || type == OP_RV2AV || type == OP_RV2HV){
0e9700df
GG		 3261 o->op_private |= (type == OP_RV2AV ? OPpDEREF_AV
3262 : type == OP_RV2HV ? OPpDEREF_HV
3263 : OPpDEREF_SV);
767eda44
FC		 3264 o->op_flags |= OPf_MOD;
3265 }
3266
8990e307 3267 break;
aeea060c 3268
463ee0b2 3269 case OP_COND_EXPR:
e6dae479 3270 for (kid = OpSIBLING(cUNOPo->op_first); kid; kid = OpSIBLING(kid))
e4c5ccf3 3271 doref(kid, type, set_op_ref);
463ee0b2 3272 break;
8990e307 3273 case OP_RV2SV:
35cd451c
GS		 3274 if (type == OP_DEFINED)
3275 o->op_flags |= OPf_SPECIAL; /* don't create GV */
e4c5ccf3 3276 doref(cUNOPo->op_first, o->op_type, set_op_ref);
924ba076 3277 /* FALLTHROUGH */
4633a7c4 3278 case OP_PADSV:
5f05dabc 3279 if (type == OP_RV2SV || type == OP_RV2AV || type == OP_RV2HV) {
5dc0d613
MB		 3280 o->op_private |= (type == OP_RV2AV ? OPpDEREF_AV
3281 : type == OP_RV2HV ? OPpDEREF_HV
3282 : OPpDEREF_SV);
11343788 3283 o->op_flags |= OPf_MOD;
a0d0e21e 3284 }
8990e307 3285 break;
1c846c1f 3286
463ee0b2
LW		 3287 case OP_RV2AV:
3288 case OP_RV2HV:
e4c5ccf3
RH		 3289 if (set_op_ref)
3290 o->op_flags |= OPf_REF;
924ba076 3291 /* FALLTHROUGH */
463ee0b2 3292 case OP_RV2GV:
35cd451c
GS		 3293 if (type == OP_DEFINED)
3294 o->op_flags |= OPf_SPECIAL; /* don't create GV */
e4c5ccf3 3295 doref(cUNOPo->op_first, o->op_type, set_op_ref);
463ee0b2 3296 break;
8990e307 3297
463ee0b2
LW		 3298 case OP_PADAV:
3299 case OP_PADHV:
e4c5ccf3
RH		 3300 if (set_op_ref)
3301 o->op_flags |= OPf_REF;
79072805 3302 break;
aeea060c 3303
8990e307 3304 case OP_SCALAR:
79072805 3305 case OP_NULL:
518618af 3306 if (!(o->op_flags & OPf_KIDS) || type == OP_DEFINED)
463ee0b2 3307 break;
e4c5ccf3 3308 doref(cBINOPo->op_first, type, set_op_ref);
79072805
LW		 3309 break;
3310 case OP_AELEM:
3311 case OP_HELEM:
e4c5ccf3 3312 doref(cBINOPo->op_first, o->op_type, set_op_ref);
5f05dabc 3313 if (type == OP_RV2SV || type == OP_RV2AV || type == OP_RV2HV) {
5dc0d613
MB		 3314 o->op_private |= (type == OP_RV2AV ? OPpDEREF_AV
3315 : type == OP_RV2HV ? OPpDEREF_HV
3316 : OPpDEREF_SV);
11343788 3317 o->op_flags |= OPf_MOD;
8990e307 3318 }
79072805
LW		 3319 break;
3320
463ee0b2 3321 case OP_SCOPE:
79072805 3322 case OP_LEAVE:
e4c5ccf3 3323 set_op_ref = FALSE;
924ba076 3324 /* FALLTHROUGH */
79072805 3325 case OP_ENTER:
8990e307 3326 case OP_LIST:
11343788 3327 if (!(o->op_flags & OPf_KIDS))
79072805 3328 break;
e4c5ccf3 3329 doref(cLISTOPo->op_last, type, set_op_ref);
79072805 3330 break;
a0d0e21e
LW		 3331 default:
3332 break;
79072805 3333 }
11343788 3334 return scalar(o);
8990e307 3335
79072805
LW		 3336}
3337
09bef843
SB		 3338STATIC OP *
3339S_dup_attrlist(pTHX_ OP *o)
3340{
0bd48802 3341 OP *rop;
09bef843 3342
7918f24d
NC		 3343 PERL_ARGS_ASSERT_DUP_ATTRLIST;
3344
09bef843
SB		 3345 /* An attrlist is either a simple OP_CONST or an OP_LIST with kids,
3346 * where the first kid is OP_PUSHMARK and the remaining ones
3347 * are OP_CONST. We need to push the OP_CONST values.
3348 */
3349 if (o->op_type == OP_CONST)
b37c2d43 3350 rop = newSVOP(OP_CONST, o->op_flags, SvREFCNT_inc_NN(cSVOPo->op_sv));
09bef843
SB		 3351 else {
3352 assert((o->op_type == OP_LIST) && (o->op_flags & OPf_KIDS));
5f66b61c 3353 rop = NULL;
e6dae479 3354 for (o = cLISTOPo->op_first; o; o = OpSIBLING(o)) {
09bef843 3355 if (o->op_type == OP_CONST)
2fcb4757 3356 rop = op_append_elem(OP_LIST, rop,
09bef843 3357 newSVOP(OP_CONST, o->op_flags,
b37c2d43 3358 SvREFCNT_inc_NN(cSVOPo->op_sv)));
09bef843
SB		 3359 }
3360 }
3361 return rop;
3362}
3363
3364STATIC void
ad0dc73b 3365S_apply_attrs(pTHX_ HV *stash, SV *target, OP *attrs)
09bef843 3366{
7918f24d 3367 PERL_ARGS_ASSERT_APPLY_ATTRS;
976258ec
JH		 3368 {
3369 SV * const stashsv = newSVhek(HvNAME_HEK(stash));
7918f24d 3370
976258ec 3371 /* fake up C<use attributes $pkg,$rv,@attrs> */
e4783991 3372
09bef843 3373#define ATTRSMODULE "attributes"
95f0a2f1
SB		 3374#define ATTRSMODULE_PM "attributes.pm"
3375
976258ec
JH		 3376 Perl_load_module(
3377 aTHX_ PERL_LOADMOD_IMPORT_OPS,
3378 newSVpvs(ATTRSMODULE),
3379 NULL,
3380 op_prepend_elem(OP_LIST,
3381 newSVOP(OP_CONST, 0, stashsv),
3382 op_prepend_elem(OP_LIST,
3383 newSVOP(OP_CONST, 0,
3384 newRV(target)),
3385 dup_attrlist(attrs))));
3386 }
09bef843
SB		 3387}
3388
95f0a2f1
SB		 3389STATIC void
3390S_apply_attrs_my(pTHX_ HV *stash, OP *target, OP *attrs, OP **imopsp)
3391{
3392 OP *pack, *imop, *arg;
ad0dc73b 3393 SV *meth, *stashsv, **svp;
95f0a2f1 3394
7918f24d
NC		 3395 PERL_ARGS_ASSERT_APPLY_ATTRS_MY;
3396
95f0a2f1
SB		 3397 if (!attrs)
3398 return;
3399
3400 assert(target->op_type == OP_PADSV ||
3401 target->op_type == OP_PADHV ||
3402 target->op_type == OP_PADAV);
3403
3404 /* Ensure that attributes.pm is loaded. */
ad0dc73b
FC		 3405 /* Don't force the C<use> if we don't need it. */
3406 svp = hv_fetchs(GvHVn(PL_incgv), ATTRSMODULE_PM, FALSE);
3407 if (svp && *svp != &PL_sv_undef)
3408 NOOP; /* already in %INC */
3409 else
3410 Perl_load_module(aTHX_ PERL_LOADMOD_NOIMPORT,
3411 newSVpvs(ATTRSMODULE), NULL);
95f0a2f1
SB		 3412
3413 /* Need package name for method call. */
6136c704 3414 pack = newSVOP(OP_CONST, 0, newSVpvs(ATTRSMODULE));
95f0a2f1
SB		 3415
3416 /* Build up the real arg-list. */
976258ec 3417 stashsv = newSVhek(HvNAME_HEK(stash));
5aaec2b4 3418
95f0a2f1
SB		 3419 arg = newOP(OP_PADSV, 0);
3420 arg->op_targ = target->op_targ;
2fcb4757 3421 arg = op_prepend_elem(OP_LIST,
95f0a2f1 3422 newSVOP(OP_CONST, 0, stashsv),
2fcb4757 3423 op_prepend_elem(OP_LIST,
95f0a2f1 3424 newUNOP(OP_REFGEN, 0,
a282984d 3425 arg),
95f0a2f1
SB		 3426 dup_attrlist(attrs)));
3427
3428 /* Fake up a method call to import */
18916d0d 3429 meth = newSVpvs_share("import");
03d05f6e 3430 imop = op_convert_list(OP_ENTERSUB, OPf_STACKED|OPf_SPECIAL|OPf_WANT_VOID,
2fcb4757 3431 op_append_elem(OP_LIST,
6aa68307 3432 op_prepend_elem(OP_LIST, pack, arg),
b46e009d 3433 newMETHOP_named(OP_METHOD_NAMED, 0, meth)));
95f0a2f1
SB		 3434
3435 /* Combine the ops. */
2fcb4757 3436 *imopsp = op_append_elem(OP_LIST, *imopsp, imop);
95f0a2f1
SB		 3437}
3438
3439/*
3440=notfor apidoc apply_attrs_string
3441
3442Attempts to apply a list of attributes specified by the C<attrstr> and
3443C<len> arguments to the subroutine identified by the C<cv> argument which
3444is expected to be associated with the package identified by the C<stashpv>
3445argument (see L<attributes>). It gets this wrong, though, in that it
3446does not correctly identify the boundaries of the individual attribute
3447specifications within C<attrstr>. This is not really intended for the
3448public API, but has to be listed here for systems such as AIX which
3449need an explicit export list for symbols. (It's called from XS code
3450in support of the C<ATTRS:> keyword from F<xsubpp>.) Patches to fix it
3451to respect attribute syntax properly would be welcome.
3452
3453=cut
3454*/
3455
be3174d2 3456void
6867be6d
AL		 3457Perl_apply_attrs_string(pTHX_ const char *stashpv, CV *cv,
3458 const char *attrstr, STRLEN len)
be3174d2 3459{
5f66b61c 3460 OP *attrs = NULL;
be3174d2 3461
7918f24d
NC		 3462 PERL_ARGS_ASSERT_APPLY_ATTRS_STRING;
3463
be3174d2
GS		 3464 if (!len) {
3465 len = strlen(attrstr);
3466 }
3467
3468 while (len) {
3469 for (; isSPACE(*attrstr) && len; --len, ++attrstr) ;
3470 if (len) {
890ce7af 3471 const char * const sstr = attrstr;
be3174d2 3472 for (; !isSPACE(*attrstr) && len; --len, ++attrstr) ;
2fcb4757 3473 attrs = op_append_elem(OP_LIST, attrs,
be3174d2
GS		 3474 newSVOP(OP_CONST, 0,
3475 newSVpvn(sstr, attrstr-sstr)));
3476 }
3477 }
3478
3479 Perl_load_module(aTHX_ PERL_LOADMOD_IMPORT_OPS,
6136c704 3480 newSVpvs(ATTRSMODULE),
2fcb4757 3481 NULL, op_prepend_elem(OP_LIST,
be3174d2 3482 newSVOP(OP_CONST, 0, newSVpv(stashpv,0)),
2fcb4757 3483 op_prepend_elem(OP_LIST,
be3174d2 3484 newSVOP(OP_CONST, 0,
ad64d0ec 3485 newRV(MUTABLE_SV(cv))),
be3174d2
GS		 3486 attrs)));
3487}
3488
eedb00fa
PM		 3489STATIC void
3490S_move_proto_attr(pTHX_ OP **proto, OP **attrs, const GV * name)
3491{
3492 OP *new_proto = NULL;
3493 STRLEN pvlen;
3494 char *pv;
3495 OP *o;
3496
3497 PERL_ARGS_ASSERT_MOVE_PROTO_ATTR;
3498
3499 if (!*attrs)
3500 return;
3501
3502 o = *attrs;
3503 if (o->op_type == OP_CONST) {
3504 pv = SvPV(cSVOPo_sv, pvlen);
3505 if (pvlen >= 10 && memEQ(pv, "prototype(", 10)) {
3506 SV * const tmpsv = newSVpvn_flags(pv + 10, pvlen - 11, SvUTF8(cSVOPo_sv));
3507 SV ** const tmpo = cSVOPx_svp(o);
3508 SvREFCNT_dec(cSVOPo_sv);
3509 *tmpo = tmpsv;
3510 new_proto = o;
3511 *attrs = NULL;
3512 }
3513 } else if (o->op_type == OP_LIST) {
e78bc664 3514 OP * lasto;
eedb00fa 3515 assert(o->op_flags & OPf_KIDS);
e78bc664
PM		 3516 lasto = cLISTOPo->op_first;
3517 assert(lasto->op_type == OP_PUSHMARK);
e6dae479 3518 for (o = OpSIBLING(lasto); o; o = OpSIBLING(o)) {
eedb00fa
PM		 3519 if (o->op_type == OP_CONST) {
3520 pv = SvPV(cSVOPo_sv, pvlen);
3521 if (pvlen >= 10 && memEQ(pv, "prototype(", 10)) {
3522 SV * const tmpsv = newSVpvn_flags(pv + 10, pvlen - 11, SvUTF8(cSVOPo_sv));
3523 SV ** const tmpo = cSVOPx_svp(o);
3524 SvREFCNT_dec(cSVOPo_sv);
3525 *tmpo = tmpsv;
3526 if (new_proto && ckWARN(WARN_MISC)) {
3527 STRLEN new_len;
3528 const char * newp = SvPV(cSVOPo_sv, new_len);
3529 Perl_warner(aTHX_ packWARN(WARN_MISC),
3530 "Attribute prototype(%"UTF8f") discards earlier prototype attribute in same sub",
3531 UTF8fARG(SvUTF8(cSVOPo_sv), new_len, newp));
3532 op_free(new_proto);
3533 }
3534 else if (new_proto)
3535 op_free(new_proto);
3536 new_proto = o;
3253bf85
DM		 3537 /* excise new_proto from the list */
3538 op_sibling_splice(*attrs, lasto, 1, NULL);
3539 o = lasto;
eedb00fa
PM		 3540 continue;
3541 }
3542 }
3543 lasto = o;
3544 }
3545 /* If the list is now just the PUSHMARK, scrap the whole thing; otherwise attributes.xs
3546 would get pulled in with no real need */
e6dae479 3547 if (!OpHAS_SIBLING(cLISTOPx(*attrs)->op_first)) {
eedb00fa
PM		 3548 op_free(*attrs);
3549 *attrs = NULL;
3550 }
3551 }
3552
3553 if (new_proto) {
3554 SV *svname;
3555 if (isGV(name)) {
3556 svname = sv_newmortal();
3557 gv_efullname3(svname, name, NULL);
3558 }
3559 else if (SvPOK(name) && *SvPVX((SV *)name) == '&')
3560 svname = newSVpvn_flags(SvPVX((SV *)name)+1, SvCUR(name)-1, SvUTF8(name)|SVs_TEMP);
3561 else
3562 svname = (SV *)name;
3563 if (ckWARN(WARN_ILLEGALPROTO))
3564 (void)validate_proto(svname, cSVOPx_sv(new_proto), TRUE);
3565 if (*proto && ckWARN(WARN_PROTOTYPE)) {
3566 STRLEN old_len, new_len;
3567 const char * oldp = SvPV(cSVOPx_sv(*proto), old_len);
3568 const char * newp = SvPV(cSVOPx_sv(new_proto), new_len);
3569
3570 Perl_warner(aTHX_ packWARN(WARN_PROTOTYPE),
3571 "Prototype '%"UTF8f"' overridden by attribute 'prototype(%"UTF8f")'"
3572 " in %"SVf,
3573 UTF8fARG(SvUTF8(cSVOPx_sv(*proto)), old_len, oldp),
3574 UTF8fARG(SvUTF8(cSVOPx_sv(new_proto)), new_len, newp),
3575 SVfARG(svname));
3576 }
3577 if (*proto)
3578 op_free(*proto);
3579 *proto = new_proto;
3580 }
3581}
3582
92bd82a0
FC		 3583static void
3584S_cant_declare(pTHX_ OP *o)
3585{
4748e002
FC		 3586 if (o->op_type == OP_NULL
3587 && (o->op_flags & (OPf_SPECIAL|OPf_KIDS)) == OPf_KIDS)
3588 o = cUNOPo->op_first;
92bd82a0 3589 yyerror(Perl_form(aTHX_ "Can't declare %s in \"%s\"",
4748e002
FC		 3590 o->op_type == OP_NULL
3591 && o->op_flags & OPf_SPECIAL
3592 ? "do block"
3593 : OP_DESC(o),
92bd82a0
FC		 3594 PL_parser->in_my == KEY_our ? "our" :
3595 PL_parser->in_my == KEY_state ? "state" :
3596 "my"));
3597}
3598
09bef843 3599STATIC OP *
95f0a2f1 3600S_my_kid(pTHX_ OP *o, OP *attrs, OP **imopsp)
93a17b20 3601{
93a17b20 3602 I32 type;
a1fba7eb 3603 const bool stately = PL_parser && PL_parser->in_my == KEY_state;
93a17b20 3604
7918f24d
NC		 3605 PERL_ARGS_ASSERT_MY_KID;
3606
13765c85 3607 if (!o || (PL_parser && PL_parser->error_count))
11343788 3608 return o;
93a17b20 3609
bc61e325 3610 type = o->op_type;
eb8433b7 3611
93a17b20 3612 if (type == OP_LIST) {
6867be6d 3613 OP *kid;
e6dae479 3614 for (kid = cLISTOPo->op_first; kid; kid = OpSIBLING(kid))
95f0a2f1 3615 my_kid(kid, attrs, imopsp);
0865059d 3616 return o;
8b8c1fb9 3617 } else if (type == OP_UNDEF || type == OP_STUB) {
7766148a 3618 return o;
77ca0c92
LW		 3619 } else if (type == OP_RV2SV || /* "our" declaration */
3620 type == OP_RV2AV ||
3621 type == OP_RV2HV) { /* XXX does this let anything illegal in? */
1ce0b88c 3622 if (cUNOPo->op_first->op_type != OP_GV) { /* MJD 20011224 */
92bd82a0 3623 S_cant_declare(aTHX_ o);
1ce0b88c 3624 } else if (attrs) {
551405c4 3625 GV * const gv = cGVOPx_gv(cUNOPo->op_first);
316ebaf2 3626 assert(PL_parser);
12bd6ede
DM		 3627 PL_parser->in_my = FALSE;
3628 PL_parser->in_my_stash = NULL;
1ce0b88c
RGS		 3629 apply_attrs(GvSTASH(gv),
3630 (type == OP_RV2SV ? GvSV(gv) :
ad64d0ec
NC		 3631 type == OP_RV2AV ? MUTABLE_SV(GvAV(gv)) :
3632 type == OP_RV2HV ? MUTABLE_SV(GvHV(gv)) : MUTABLE_SV(gv)),
ad0dc73b 3633 attrs);
1ce0b88c 3634 }
192587c2 3635 o->op_private |= OPpOUR_INTRO;
77ca0c92 3636 return o;
95f0a2f1
SB		 3637 }
3638 else if (type != OP_PADSV &&
93a17b20
LW		 3639 type != OP_PADAV &&
3640 type != OP_PADHV &&
3641 type != OP_PUSHMARK)
3642 {
92bd82a0 3643 S_cant_declare(aTHX_ o);
11343788 3644 return o;
93a17b20 3645 }
09bef843
SB		 3646 else if (attrs && type != OP_PUSHMARK) {
3647 HV *stash;
09bef843 3648
316ebaf2 3649 assert(PL_parser);
12bd6ede
DM		 3650 PL_parser->in_my = FALSE;
3651 PL_parser->in_my_stash = NULL;
eb64745e 3652
09bef843 3653 /* check for C<my Dog $spot> when deciding package */
dd2155a4
DM		 3654 stash = PAD_COMPNAME_TYPE(o->op_targ);
3655 if (!stash)
09bef843 3656 stash = PL_curstash;
95f0a2f1 3657 apply_attrs_my(stash, o, attrs, imopsp);
09bef843 3658 }
11343788
MB		 3659 o->op_flags |= OPf_MOD;
3660 o->op_private |= OPpLVAL_INTRO;
a1fba7eb 3661 if (stately)
952306ac 3662 o->op_private |= OPpPAD_STATE;
11343788 3663 return o;
93a17b20
LW		 3664}
3665
3666OP *
09bef843
SB		 3667Perl_my_attrs(pTHX_ OP *o, OP *attrs)
3668{
0bd48802 3669 OP *rops;
95f0a2f1
SB		 3670 int maybe_scalar = 0;
3671
7918f24d
NC		 3672 PERL_ARGS_ASSERT_MY_ATTRS;
3673
d2be0de5 3674/* [perl #17376]: this appears to be premature, and results in code such as
c754c3d7 3675 C< our(%x); > executing in list mode rather than void mode */
d2be0de5 3676#if 0
09bef843
SB		 3677 if (o->op_flags & OPf_PARENS)
3678 list(o);
95f0a2f1
SB		 3679 else
3680 maybe_scalar = 1;
d2be0de5
YST		 3681#else
3682 maybe_scalar = 1;
3683#endif
09bef843
SB		 3684 if (attrs)
3685 SAVEFREEOP(attrs);
5f66b61c 3686 rops = NULL;
95f0a2f1
SB		 3687 o = my_kid(o, attrs, &rops);
3688 if (rops) {
3689 if (maybe_scalar && o->op_type == OP_PADSV) {
2fcb4757 3690 o = scalar(op_append_list(OP_LIST, rops, o));
95f0a2f1
SB		 3691 o->op_private |= OPpLVAL_INTRO;
3692 }
f5d1ed10
FC		 3693 else {
3694 /* The listop in rops might have a pushmark at the beginning,
3695 which will mess up list assignment. */
3696 LISTOP * const lrops = (LISTOP *)rops; /* for brevity */
3697 if (rops->op_type == OP_LIST &&
3698 lrops->op_first && lrops->op_first->op_type == OP_PUSHMARK)
3699 {
3700 OP * const pushmark = lrops->op_first;
3253bf85
DM		 3701 /* excise pushmark */
3702 op_sibling_splice(rops, NULL, 1, NULL);
f5d1ed10
FC		 3703 op_free(pushmark);
3704 }
2fcb4757 3705 o = op_append_list(OP_LIST, o, rops);
f5d1ed10 3706 }
95f0a2f1 3707 }
12bd6ede
DM		 3708 PL_parser->in_my = FALSE;
3709 PL_parser->in_my_stash = NULL;
eb64745e 3710 return o;