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4b88f280 1#line 2 "op.c"
a0d0e21e 2/* op.c
79072805 3 *
1129b882
NC
4 * Copyright (C) 1991, 1992, 1993, 1994, 1995, 1996, 1997, 1998, 1999, 2000,
5 * 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008 by Larry Wall and others
79072805
LW
6 *
7 * You may distribute under the terms of either the GNU General Public
8 * License or the Artistic License, as specified in the README file.
9 *
a0d0e21e
LW
10 */
11
12/*
4ac71550
TC
13 * 'You see: Mr. Drogo, he married poor Miss Primula Brandybuck. She was
14 * our Mr. Bilbo's first cousin on the mother's side (her mother being the
15 * youngest of the Old Took's daughters); and Mr. Drogo was his second
16 * cousin. So Mr. Frodo is his first *and* second cousin, once removed
17 * either way, as the saying is, if you follow me.' --the Gaffer
18 *
19 * [p.23 of _The Lord of the Rings_, I/i: "A Long-Expected Party"]
79072805
LW
20 */
21
166f8a29
DM
22/* This file contains the functions that create, manipulate and optimize
23 * the OP structures that hold a compiled perl program.
24 *
25 * A Perl program is compiled into a tree of OPs. Each op contains
26 * structural pointers (eg to its siblings and the next op in the
27 * execution sequence), a pointer to the function that would execute the
28 * op, plus any data specific to that op. For example, an OP_CONST op
29 * points to the pp_const() function and to an SV containing the constant
30 * value. When pp_const() is executed, its job is to push that SV onto the
31 * stack.
32 *
33 * OPs are mainly created by the newFOO() functions, which are mainly
34 * called from the parser (in perly.y) as the code is parsed. For example
35 * the Perl code $a + $b * $c would cause the equivalent of the following
36 * to be called (oversimplifying a bit):
37 *
38 * newBINOP(OP_ADD, flags,
39 * newSVREF($a),
40 * newBINOP(OP_MULTIPLY, flags, newSVREF($b), newSVREF($c))
41 * )
42 *
43 * Note that during the build of miniperl, a temporary copy of this file
44 * is made, called opmini.c.
45 */
ccfc67b7 46
61b743bb
DM
47/*
48Perl's compiler is essentially a 3-pass compiler with interleaved phases:
49
50 A bottom-up pass
51 A top-down pass
52 An execution-order pass
53
54The bottom-up pass is represented by all the "newOP" routines and
55the ck_ routines. The bottom-upness is actually driven by yacc.
56So at the point that a ck_ routine fires, we have no idea what the
57context is, either upward in the syntax tree, or either forward or
58backward in the execution order. (The bottom-up parser builds that
59part of the execution order it knows about, but if you follow the "next"
60links around, you'll find it's actually a closed loop through the
ef9da979 61top level node.)
61b743bb
DM
62
63Whenever the bottom-up parser gets to a node that supplies context to
64its components, it invokes that portion of the top-down pass that applies
65to that part of the subtree (and marks the top node as processed, so
66if a node further up supplies context, it doesn't have to take the
67plunge again). As a particular subcase of this, as the new node is
68built, it takes all the closed execution loops of its subcomponents
69and links them into a new closed loop for the higher level node. But
70it's still not the real execution order.
71
72The actual execution order is not known till we get a grammar reduction
73to a top-level unit like a subroutine or file that will be called by
74"name" rather than via a "next" pointer. At that point, we can call
75into peep() to do that code's portion of the 3rd pass. It has to be
76recursive, but it's recursive on basic blocks, not on tree nodes.
77*/
78
06e0342d 79/* To implement user lexical pragmas, there needs to be a way at run time to
b3ca2e83
NC
80 get the compile time state of %^H for that block. Storing %^H in every
81 block (or even COP) would be very expensive, so a different approach is
82 taken. The (running) state of %^H is serialised into a tree of HE-like
83 structs. Stores into %^H are chained onto the current leaf as a struct
84 refcounted_he * with the key and the value. Deletes from %^H are saved
85 with a value of PL_sv_placeholder. The state of %^H at any point can be
86 turned back into a regular HV by walking back up the tree from that point's
06e0342d 87 leaf, ignoring any key you've already seen (placeholder or not), storing
b3ca2e83
NC
88 the rest into the HV structure, then removing the placeholders. Hence
89 memory is only used to store the %^H deltas from the enclosing COP, rather
90 than the entire %^H on each COP.
91
92 To cause actions on %^H to write out the serialisation records, it has
93 magic type 'H'. This magic (itself) does nothing, but its presence causes
94 the values to gain magic type 'h', which has entries for set and clear.
c28fe1ec 95 C<Perl_magic_sethint> updates C<PL_compiling.cop_hints_hash> with a store
34795b44 96 record, with deletes written by C<Perl_magic_clearhint>. C<SAVEHINTS>
c28fe1ec
NC
97 saves the current C<PL_compiling.cop_hints_hash> on the save stack, so that
98 it will be correctly restored when any inner compiling scope is exited.
b3ca2e83
NC
99*/
100
79072805 101#include "EXTERN.h"
864dbfa3 102#define PERL_IN_OP_C
79072805 103#include "perl.h"
77ca0c92 104#include "keywords.h"
2846acbf 105#include "feature.h"
74529a43 106#include "regcomp.h"
79072805 107
16c91539 108#define CALL_PEEP(o) PL_peepp(aTHX_ o)
1a0a2ba9 109#define CALL_RPEEP(o) PL_rpeepp(aTHX_ o)
16c91539 110#define CALL_OPFREEHOOK(o) if (PL_opfreehook) PL_opfreehook(aTHX_ o)
a2efc822 111
72621f84
DM
112/* remove any leading "empty" ops from the op_next chain whose first
113 * node's address is stored in op_p. Store the updated address of the
114 * first node in op_p.
115 */
116
117STATIC void
dc3bf405 118S_prune_chain_head(OP** op_p)
72621f84
DM
119{
120 while (*op_p
121 && ( (*op_p)->op_type == OP_NULL
122 || (*op_p)->op_type == OP_SCOPE
123 || (*op_p)->op_type == OP_SCALAR
124 || (*op_p)->op_type == OP_LINESEQ)
125 )
126 *op_p = (*op_p)->op_next;
127}
128
129
8be227ab
FC
130/* See the explanatory comments above struct opslab in op.h. */
131
7aef8e5b 132#ifdef PERL_DEBUG_READONLY_OPS
3107b51f
FC
133# define PERL_SLAB_SIZE 128
134# define PERL_MAX_SLAB_SIZE 4096
135# include <sys/mman.h>
7aef8e5b 136#endif
3107b51f 137
7aef8e5b 138#ifndef PERL_SLAB_SIZE
8be227ab 139# define PERL_SLAB_SIZE 64
7aef8e5b
FC
140#endif
141#ifndef PERL_MAX_SLAB_SIZE
e6cee8c0 142# define PERL_MAX_SLAB_SIZE 2048
7aef8e5b 143#endif
8be227ab
FC
144
145/* rounds up to nearest pointer */
7aef8e5b
FC
146#define SIZE_TO_PSIZE(x) (((x) + sizeof(I32 *) - 1)/sizeof(I32 *))
147#define DIFF(o,p) ((size_t)((I32 **)(p) - (I32**)(o)))
8be227ab
FC
148
149static OPSLAB *
150S_new_slab(pTHX_ size_t sz)
151{
7aef8e5b 152#ifdef PERL_DEBUG_READONLY_OPS
3107b51f
FC
153 OPSLAB *slab = (OPSLAB *) mmap(0, sz * sizeof(I32 *),
154 PROT_READ|PROT_WRITE,
155 MAP_ANON|MAP_PRIVATE, -1, 0);
156 DEBUG_m(PerlIO_printf(Perl_debug_log, "mapped %lu at %p\n",
157 (unsigned long) sz, slab));
158 if (slab == MAP_FAILED) {
159 perror("mmap failed");
160 abort();
161 }
162 slab->opslab_size = (U16)sz;
7aef8e5b 163#else
8be227ab 164 OPSLAB *slab = (OPSLAB *)PerlMemShared_calloc(sz, sizeof(I32 *));
7aef8e5b 165#endif
dc3bf405
BF
166#ifndef WIN32
167 /* The context is unused in non-Windows */
168 PERL_UNUSED_CONTEXT;
169#endif
8be227ab
FC
170 slab->opslab_first = (OPSLOT *)((I32 **)slab + sz - 1);
171 return slab;
172}
173
e7372881
FC
174/* requires double parens and aTHX_ */
175#define DEBUG_S_warn(args) \
176 DEBUG_S( \
177 PerlIO_printf(Perl_debug_log, "%s", SvPVx_nolen(Perl_mess args)) \
178 )
179
8be227ab
FC
180void *
181Perl_Slab_Alloc(pTHX_ size_t sz)
182{
8be227ab
FC
183 OPSLAB *slab;
184 OPSLAB *slab2;
185 OPSLOT *slot;
186 OP *o;
5cb52f30 187 size_t opsz, space;
8be227ab 188
2073970f
NC
189 /* We only allocate ops from the slab during subroutine compilation.
190 We find the slab via PL_compcv, hence that must be non-NULL. It could
191 also be pointing to a subroutine which is now fully set up (CvROOT()
192 pointing to the top of the optree for that sub), or a subroutine
193 which isn't using the slab allocator. If our sanity checks aren't met,
194 don't use a slab, but allocate the OP directly from the heap. */
8be227ab
FC
195 if (!PL_compcv || CvROOT(PL_compcv)
196 || (CvSTART(PL_compcv) && !CvSLABBED(PL_compcv)))
29e61fd9
DM
197 {
198 o = (OP*)PerlMemShared_calloc(1, sz);
199 goto gotit;
200 }
8be227ab 201
2073970f
NC
202 /* While the subroutine is under construction, the slabs are accessed via
203 CvSTART(), to avoid needing to expand PVCV by one pointer for something
204 unneeded at runtime. Once a subroutine is constructed, the slabs are
205 accessed via CvROOT(). So if CvSTART() is NULL, no slab has been
206 allocated yet. See the commit message for 8be227ab5eaa23f2 for more
207 details. */
208 if (!CvSTART(PL_compcv)) {
8be227ab
FC
209 CvSTART(PL_compcv) =
210 (OP *)(slab = S_new_slab(aTHX_ PERL_SLAB_SIZE));
211 CvSLABBED_on(PL_compcv);
212 slab->opslab_refcnt = 2; /* one for the CV; one for the new OP */
213 }
214 else ++(slab = (OPSLAB *)CvSTART(PL_compcv))->opslab_refcnt;
215
5cb52f30
FC
216 opsz = SIZE_TO_PSIZE(sz);
217 sz = opsz + OPSLOT_HEADER_P;
8be227ab 218
2073970f
NC
219 /* The slabs maintain a free list of OPs. In particular, constant folding
220 will free up OPs, so it makes sense to re-use them where possible. A
221 freed up slot is used in preference to a new allocation. */
8be227ab
FC
222 if (slab->opslab_freed) {
223 OP **too = &slab->opslab_freed;
224 o = *too;
eb212a1c 225 DEBUG_S_warn((aTHX_ "found free op at %p, slab %p", (void*)o, (void*)slab));
8be227ab 226 while (o && DIFF(OpSLOT(o), OpSLOT(o)->opslot_next) < sz) {
e7372881 227 DEBUG_S_warn((aTHX_ "Alas! too small"));
8be227ab 228 o = *(too = &o->op_next);
eb212a1c 229 if (o) { DEBUG_S_warn((aTHX_ "found another free op at %p", (void*)o)); }
8be227ab
FC
230 }
231 if (o) {
232 *too = o->op_next;
5cb52f30 233 Zero(o, opsz, I32 *);
8be227ab 234 o->op_slabbed = 1;
29e61fd9 235 goto gotit;
8be227ab
FC
236 }
237 }
238
7aef8e5b 239#define INIT_OPSLOT \
8be227ab
FC
240 slot->opslot_slab = slab; \
241 slot->opslot_next = slab2->opslab_first; \
242 slab2->opslab_first = slot; \
243 o = &slot->opslot_op; \
244 o->op_slabbed = 1
245
246 /* The partially-filled slab is next in the chain. */
247 slab2 = slab->opslab_next ? slab->opslab_next : slab;
248 if ((space = DIFF(&slab2->opslab_slots, slab2->opslab_first)) < sz) {
249 /* Remaining space is too small. */
250
8be227ab
FC
251 /* If we can fit a BASEOP, add it to the free chain, so as not
252 to waste it. */
253 if (space >= SIZE_TO_PSIZE(sizeof(OP)) + OPSLOT_HEADER_P) {
254 slot = &slab2->opslab_slots;
255 INIT_OPSLOT;
256 o->op_type = OP_FREED;
257 o->op_next = slab->opslab_freed;
258 slab->opslab_freed = o;
259 }
260
261 /* Create a new slab. Make this one twice as big. */
262 slot = slab2->opslab_first;
263 while (slot->opslot_next) slot = slot->opslot_next;
af7751f6
FC
264 slab2 = S_new_slab(aTHX_
265 (DIFF(slab2, slot)+1)*2 > PERL_MAX_SLAB_SIZE
e6cee8c0 266 ? PERL_MAX_SLAB_SIZE
af7751f6 267 : (DIFF(slab2, slot)+1)*2);
9963ffa2
FC
268 slab2->opslab_next = slab->opslab_next;
269 slab->opslab_next = slab2;
8be227ab
FC
270 }
271 assert(DIFF(&slab2->opslab_slots, slab2->opslab_first) >= sz);
272
273 /* Create a new op slot */
274 slot = (OPSLOT *)((I32 **)slab2->opslab_first - sz);
275 assert(slot >= &slab2->opslab_slots);
51c777ca
FC
276 if (DIFF(&slab2->opslab_slots, slot)
277 < SIZE_TO_PSIZE(sizeof(OP)) + OPSLOT_HEADER_P)
278 slot = &slab2->opslab_slots;
8be227ab 279 INIT_OPSLOT;
eb212a1c 280 DEBUG_S_warn((aTHX_ "allocating op at %p, slab %p", (void*)o, (void*)slab));
29e61fd9
DM
281
282 gotit:
283 /* lastsib == 1, op_sibling == 0 implies a solitary unattached op */
284 o->op_lastsib = 1;
285 assert(!o->op_sibling);
286
8be227ab
FC
287 return (void *)o;
288}
289
7aef8e5b 290#undef INIT_OPSLOT
8be227ab 291
7aef8e5b 292#ifdef PERL_DEBUG_READONLY_OPS
3107b51f
FC
293void
294Perl_Slab_to_ro(pTHX_ OPSLAB *slab)
295{
296 PERL_ARGS_ASSERT_SLAB_TO_RO;
297
298 if (slab->opslab_readonly) return;
299 slab->opslab_readonly = 1;
300 for (; slab; slab = slab->opslab_next) {
301 /*DEBUG_U(PerlIO_printf(Perl_debug_log,"mprotect ->ro %lu at %p\n",
302 (unsigned long) slab->opslab_size, slab));*/
303 if (mprotect(slab, slab->opslab_size * sizeof(I32 *), PROT_READ))
304 Perl_warn(aTHX_ "mprotect for %p %lu failed with %d", slab,
305 (unsigned long)slab->opslab_size, errno);
306 }
307}
308
7bbbc3c0
NC
309void
310Perl_Slab_to_rw(pTHX_ OPSLAB *const slab)
3107b51f 311{
3107b51f
FC
312 OPSLAB *slab2;
313
314 PERL_ARGS_ASSERT_SLAB_TO_RW;
315
3107b51f
FC
316 if (!slab->opslab_readonly) return;
317 slab2 = slab;
318 for (; slab2; slab2 = slab2->opslab_next) {
319 /*DEBUG_U(PerlIO_printf(Perl_debug_log,"mprotect ->rw %lu at %p\n",
320 (unsigned long) size, slab2));*/
321 if (mprotect((void *)slab2, slab2->opslab_size * sizeof(I32 *),
322 PROT_READ|PROT_WRITE)) {
323 Perl_warn(aTHX_ "mprotect RW for %p %lu failed with %d", slab,
324 (unsigned long)slab2->opslab_size, errno);
325 }
326 }
327 slab->opslab_readonly = 0;
328}
329
330#else
9e4d7a13 331# define Slab_to_rw(op) NOOP
3107b51f
FC
332#endif
333
8be227ab
FC
334/* This cannot possibly be right, but it was copied from the old slab
335 allocator, to which it was originally added, without explanation, in
336 commit 083fcd5. */
7aef8e5b 337#ifdef NETWARE
8be227ab 338# define PerlMemShared PerlMem
7aef8e5b 339#endif
8be227ab
FC
340
341void
342Perl_Slab_Free(pTHX_ void *op)
343{
344 OP * const o = (OP *)op;
345 OPSLAB *slab;
346
347 PERL_ARGS_ASSERT_SLAB_FREE;
348
349 if (!o->op_slabbed) {
90840c5d
RU
350 if (!o->op_static)
351 PerlMemShared_free(op);
8be227ab
FC
352 return;
353 }
354
355 slab = OpSLAB(o);
356 /* If this op is already freed, our refcount will get screwy. */
357 assert(o->op_type != OP_FREED);
358 o->op_type = OP_FREED;
359 o->op_next = slab->opslab_freed;
360 slab->opslab_freed = o;
eb212a1c 361 DEBUG_S_warn((aTHX_ "free op at %p, recorded in slab %p", (void*)o, (void*)slab));
8be227ab
FC
362 OpslabREFCNT_dec_padok(slab);
363}
364
365void
366Perl_opslab_free_nopad(pTHX_ OPSLAB *slab)
367{
8be227ab
FC
368 const bool havepad = !!PL_comppad;
369 PERL_ARGS_ASSERT_OPSLAB_FREE_NOPAD;
370 if (havepad) {
371 ENTER;
372 PAD_SAVE_SETNULLPAD();
373 }
374 opslab_free(slab);
375 if (havepad) LEAVE;
376}
377
378void
379Perl_opslab_free(pTHX_ OPSLAB *slab)
380{
381 OPSLAB *slab2;
382 PERL_ARGS_ASSERT_OPSLAB_FREE;
81611534 383 PERL_UNUSED_CONTEXT;
eb212a1c 384 DEBUG_S_warn((aTHX_ "freeing slab %p", (void*)slab));
8be227ab
FC
385 assert(slab->opslab_refcnt == 1);
386 for (; slab; slab = slab2) {
387 slab2 = slab->opslab_next;
7aef8e5b 388#ifdef DEBUGGING
8be227ab 389 slab->opslab_refcnt = ~(size_t)0;
7aef8e5b
FC
390#endif
391#ifdef PERL_DEBUG_READONLY_OPS
3107b51f 392 DEBUG_m(PerlIO_printf(Perl_debug_log, "Deallocate slab at %p\n",
eb212a1c 393 (void*)slab));
3107b51f
FC
394 if (munmap(slab, slab->opslab_size * sizeof(I32 *))) {
395 perror("munmap failed");
396 abort();
397 }
7aef8e5b 398#else
8be227ab 399 PerlMemShared_free(slab);
7aef8e5b 400#endif
8be227ab
FC
401 }
402}
403
404void
405Perl_opslab_force_free(pTHX_ OPSLAB *slab)
406{
407 OPSLAB *slab2;
408 OPSLOT *slot;
7aef8e5b 409#ifdef DEBUGGING
8be227ab 410 size_t savestack_count = 0;
7aef8e5b 411#endif
8be227ab
FC
412 PERL_ARGS_ASSERT_OPSLAB_FORCE_FREE;
413 slab2 = slab;
414 do {
415 for (slot = slab2->opslab_first;
416 slot->opslot_next;
417 slot = slot->opslot_next) {
418 if (slot->opslot_op.op_type != OP_FREED
419 && !(slot->opslot_op.op_savefree
7aef8e5b 420#ifdef DEBUGGING
8be227ab 421 && ++savestack_count
7aef8e5b 422#endif
8be227ab
FC
423 )
424 ) {
425 assert(slot->opslot_op.op_slabbed);
8be227ab 426 op_free(&slot->opslot_op);
3bf28c7e 427 if (slab->opslab_refcnt == 1) goto free;
8be227ab
FC
428 }
429 }
430 } while ((slab2 = slab2->opslab_next));
431 /* > 1 because the CV still holds a reference count. */
432 if (slab->opslab_refcnt > 1) { /* still referenced by the savestack */
7aef8e5b 433#ifdef DEBUGGING
8be227ab 434 assert(savestack_count == slab->opslab_refcnt-1);
7aef8e5b 435#endif
ee5ee853
FC
436 /* Remove the CV’s reference count. */
437 slab->opslab_refcnt--;
8be227ab
FC
438 return;
439 }
440 free:
441 opslab_free(slab);
442}
443
3107b51f
FC
444#ifdef PERL_DEBUG_READONLY_OPS
445OP *
446Perl_op_refcnt_inc(pTHX_ OP *o)
447{
448 if(o) {
372eab01
NC
449 OPSLAB *const slab = o->op_slabbed ? OpSLAB(o) : NULL;
450 if (slab && slab->opslab_readonly) {
83519873 451 Slab_to_rw(slab);
372eab01
NC
452 ++o->op_targ;
453 Slab_to_ro(slab);
454 } else {
455 ++o->op_targ;
456 }
3107b51f
FC
457 }
458 return o;
459
460}
461
462PADOFFSET
463Perl_op_refcnt_dec(pTHX_ OP *o)
464{
372eab01
NC
465 PADOFFSET result;
466 OPSLAB *const slab = o->op_slabbed ? OpSLAB(o) : NULL;
467
3107b51f 468 PERL_ARGS_ASSERT_OP_REFCNT_DEC;
372eab01
NC
469
470 if (slab && slab->opslab_readonly) {
83519873 471 Slab_to_rw(slab);
372eab01
NC
472 result = --o->op_targ;
473 Slab_to_ro(slab);
474 } else {
475 result = --o->op_targ;
476 }
477 return result;
3107b51f
FC
478}
479#endif
e50aee73 480/*
ce6f1cbc 481 * In the following definition, the ", (OP*)0" is just to make the compiler
a5f75d66 482 * think the expression is of the right type: croak actually does a Siglongjmp.
e50aee73 483 */
11343788 484#define CHECKOP(type,o) \
ce6f1cbc 485 ((PL_op_mask && PL_op_mask[type]) \
5dc0d613 486 ? ( op_free((OP*)o), \
cb77fdf0 487 Perl_croak(aTHX_ "'%s' trapped by operation mask", PL_op_desc[type]), \
ce6f1cbc 488 (OP*)0 ) \
16c91539 489 : PL_check[type](aTHX_ (OP*)o))
e50aee73 490
e6438c1a 491#define RETURN_UNLIMITED_NUMBER (PERL_INT_MAX / 2)
c53d7c7d 492
cba5a3b0
DG
493#define CHANGE_TYPE(o,type) \
494 STMT_START { \
495 o->op_type = (OPCODE)type; \
496 o->op_ppaddr = PL_ppaddr[type]; \
497 } STMT_END
498
76e3520e 499STATIC OP *
cea2e8a9 500S_no_fh_allowed(pTHX_ OP *o)
79072805 501{
7918f24d
NC
502 PERL_ARGS_ASSERT_NO_FH_ALLOWED;
503
cea2e8a9 504 yyerror(Perl_form(aTHX_ "Missing comma after first argument to %s function",
53e06cf0 505 OP_DESC(o)));
11343788 506 return o;
79072805
LW
507}
508
76e3520e 509STATIC OP *
ce16c625
BF
510S_too_few_arguments_pv(pTHX_ OP *o, const char* name, U32 flags)
511{
512 PERL_ARGS_ASSERT_TOO_FEW_ARGUMENTS_PV;
513 yyerror_pv(Perl_form(aTHX_ "Not enough arguments for %s", name), flags);
514 return o;
515}
516
517STATIC OP *
518S_too_many_arguments_pv(pTHX_ OP *o, const char *name, U32 flags)
519{
520 PERL_ARGS_ASSERT_TOO_MANY_ARGUMENTS_PV;
7918f24d 521
ce16c625 522 yyerror_pv(Perl_form(aTHX_ "Too many arguments for %s", name), flags);
11343788 523 return o;
79072805
LW
524}
525
76e3520e 526STATIC void
ce16c625 527S_bad_type_pv(pTHX_ I32 n, const char *t, const char *name, U32 flags, const OP *kid)
8990e307 528{
ce16c625
BF
529 PERL_ARGS_ASSERT_BAD_TYPE_PV;
530
531 yyerror_pv(Perl_form(aTHX_ "Type of arg %d to %s must be %s (not %s)",
532 (int)n, name, t, OP_DESC(kid)), flags);
533}
7918f24d 534
ce16c625 535STATIC void
7b3b0904 536S_bad_type_gv(pTHX_ I32 n, const char *t, GV *gv, U32 flags, const OP *kid)
ce16c625 537{
ecf05a58 538 SV * const namesv = cv_name((CV *)gv, NULL, 0);
7b3b0904 539 PERL_ARGS_ASSERT_BAD_TYPE_GV;
ce16c625
BF
540
541 yyerror_pv(Perl_form(aTHX_ "Type of arg %d to %"SVf" must be %s (not %s)",
542 (int)n, SVfARG(namesv), t, OP_DESC(kid)), SvUTF8(namesv) | flags);
8990e307
LW
543}
544
7a52d87a 545STATIC void
eb796c7f 546S_no_bareword_allowed(pTHX_ OP *o)
7a52d87a 547{
7918f24d
NC
548 PERL_ARGS_ASSERT_NO_BAREWORD_ALLOWED;
549
5a844595 550 qerror(Perl_mess(aTHX_
35c1215d 551 "Bareword \"%"SVf"\" not allowed while \"strict subs\" in use",
be2597df 552 SVfARG(cSVOPo_sv)));
eb796c7f 553 o->op_private &= ~OPpCONST_STRICT; /* prevent warning twice about the same OP */
7a52d87a
GS
554}
555
79072805
LW
556/* "register" allocation */
557
558PADOFFSET
d6447115 559Perl_allocmy(pTHX_ const char *const name, const STRLEN len, const U32 flags)
93a17b20 560{
a0d0e21e 561 PADOFFSET off;
12bd6ede 562 const bool is_our = (PL_parser->in_my == KEY_our);
a0d0e21e 563
7918f24d
NC
564 PERL_ARGS_ASSERT_ALLOCMY;
565
48d0d1be 566 if (flags & ~SVf_UTF8)
d6447115
NC
567 Perl_croak(aTHX_ "panic: allocmy illegal flag bits 0x%" UVxf,
568 (UV)flags);
569
59f00321 570 /* complain about "my $<special_var>" etc etc */
d6447115 571 if (len &&
3edf23ff 572 !(is_our ||
155aba94 573 isALPHA(name[1]) ||
b14845b4 574 ((flags & SVf_UTF8) && isIDFIRST_utf8((U8 *)name+1)) ||
d6447115 575 (name[1] == '_' && (*name == '$' || len > 2))))
834a4ddd 576 {
b14845b4
FC
577 if (!(flags & SVf_UTF8 && UTF8_IS_START(name[1]))
578 && (!isPRINT(name[1]) || strchr("\t\n\r\f", name[1]))) {
d6447115
NC
579 yyerror(Perl_form(aTHX_ "Can't use global %c^%c%.*s in \"%s\"",
580 name[0], toCTRL(name[1]), (int)(len - 2), name + 2,
aab6a793 581 PL_parser->in_my == KEY_state ? "state" : "my"));
d1544d85 582 } else {
ce16c625
BF
583 yyerror_pv(Perl_form(aTHX_ "Can't use global %.*s in \"%s\"", (int) len, name,
584 PL_parser->in_my == KEY_state ? "state" : "my"), flags & SVf_UTF8);
46fc3d4c 585 }
a0d0e21e 586 }
4055dbce
RS
587 else if (len == 2 && name[1] == '_' && !is_our)
588 /* diag_listed_as: Use of my $_ is experimental */
589 Perl_ck_warner_d(aTHX_ packWARN(WARN_EXPERIMENTAL__LEXICAL_TOPIC),
590 "Use of %s $_ is experimental",
591 PL_parser->in_my == KEY_state
592 ? "state"
593 : "my");
748a9306 594
dd2155a4 595 /* allocate a spare slot and store the name in that slot */
93a17b20 596
cc76b5cc 597 off = pad_add_name_pvn(name, len,
48d0d1be
BF
598 (is_our ? padadd_OUR :
599 PL_parser->in_my == KEY_state ? padadd_STATE : 0)
600 | ( flags & SVf_UTF8 ? SVf_UTF8 : 0 ),
12bd6ede 601 PL_parser->in_my_stash,
3edf23ff 602 (is_our
133706a6 603 /* $_ is always in main::, even with our */
ef00320b
FC
604 ? (PL_curstash && !memEQs(name,len,"$_")
605 ? PL_curstash
606 : PL_defstash)
5c284bb0 607 : NULL
cca43f78 608 )
dd2155a4 609 );
a74073ad
DM
610 /* anon sub prototypes contains state vars should always be cloned,
611 * otherwise the state var would be shared between anon subs */
612
613 if (PL_parser->in_my == KEY_state && CvANON(PL_compcv))
614 CvCLONE_on(PL_compcv);
615
dd2155a4 616 return off;
79072805
LW
617}
618
c0b8aebd 619/*
dcccc8ff
KW
620=head1 Optree Manipulation Functions
621
c0b8aebd
FC
622=for apidoc alloccopstash
623
624Available only under threaded builds, this function allocates an entry in
625C<PL_stashpad> for the stash passed to it.
626
627=cut
628*/
629
d4d03940
FC
630#ifdef USE_ITHREADS
631PADOFFSET
1dc74fdb 632Perl_alloccopstash(pTHX_ HV *hv)
d4d03940
FC
633{
634 PADOFFSET off = 0, o = 1;
635 bool found_slot = FALSE;
636
1dc74fdb
FC
637 PERL_ARGS_ASSERT_ALLOCCOPSTASH;
638
639 if (PL_stashpad[PL_stashpadix] == hv) return PL_stashpadix;
d4d03940 640
1dc74fdb
FC
641 for (; o < PL_stashpadmax; ++o) {
642 if (PL_stashpad[o] == hv) return PL_stashpadix = o;
643 if (!PL_stashpad[o] || SvTYPE(PL_stashpad[o]) != SVt_PVHV)
d4d03940
FC
644 found_slot = TRUE, off = o;
645 }
646 if (!found_slot) {
1dc74fdb
FC
647 Renew(PL_stashpad, PL_stashpadmax + 10, HV *);
648 Zero(PL_stashpad + PL_stashpadmax, 10, HV *);
649 off = PL_stashpadmax;
650 PL_stashpadmax += 10;
d4d03940
FC
651 }
652
1dc74fdb 653 PL_stashpad[PL_stashpadix = off] = hv;
d4d03940
FC
654 return off;
655}
656#endif
657
d2c837a0
DM
658/* free the body of an op without examining its contents.
659 * Always use this rather than FreeOp directly */
660
4136a0f7 661static void
d2c837a0
DM
662S_op_destroy(pTHX_ OP *o)
663{
d2c837a0
DM
664 FreeOp(o);
665}
666
79072805
LW
667/* Destructor */
668
6e53b6ca
DD
669/*
670=for apidoc Am|void|op_free|OP *o
671
cc41839b
FC
672Free an op. Only use this when an op is no longer linked to from any
673optree.
6e53b6ca
DD
674
675=cut
676*/
677
79072805 678void
864dbfa3 679Perl_op_free(pTHX_ OP *o)
79072805 680{
27da23d5 681 dVAR;
acb36ea4 682 OPCODE type;
79072805 683
8be227ab
FC
684 /* Though ops may be freed twice, freeing the op after its slab is a
685 big no-no. */
686 assert(!o || !o->op_slabbed || OpSLAB(o)->opslab_refcnt != ~(size_t)0);
8be227ab
FC
687 /* During the forced freeing of ops after compilation failure, kidops
688 may be freed before their parents. */
689 if (!o || o->op_type == OP_FREED)
79072805
LW
690 return;
691
67566ccd 692 type = o->op_type;
d0c8136d
DM
693
694 /* an op should only ever acquire op_private flags that we know about.
695 * If this fails, you may need to fix something in regen/op_private */
e2a5b720
FC
696 if (o->op_ppaddr == PL_ppaddr[o->op_type]) {
697 assert(!(o->op_private & ~PL_op_private_valid[type]));
698 }
d0c8136d 699
7934575e 700 if (o->op_private & OPpREFCOUNTED) {
67566ccd 701 switch (type) {
7934575e
GS
702 case OP_LEAVESUB:
703 case OP_LEAVESUBLV:
704 case OP_LEAVEEVAL:
705 case OP_LEAVE:
706 case OP_SCOPE:
707 case OP_LEAVEWRITE:
67566ccd
AL
708 {
709 PADOFFSET refcnt;
7934575e 710 OP_REFCNT_LOCK;
4026c95a 711 refcnt = OpREFCNT_dec(o);
7934575e 712 OP_REFCNT_UNLOCK;
bfd0ff22
NC
713 if (refcnt) {
714 /* Need to find and remove any pattern match ops from the list
715 we maintain for reset(). */
716 find_and_forget_pmops(o);
4026c95a 717 return;
67566ccd 718 }
bfd0ff22 719 }
7934575e
GS
720 break;
721 default:
722 break;
723 }
724 }
725
f37b8c3f
VP
726 /* Call the op_free hook if it has been set. Do it now so that it's called
727 * at the right time for refcounted ops, but still before all of the kids
728 * are freed. */
729 CALL_OPFREEHOOK(o);
730
11343788 731 if (o->op_flags & OPf_KIDS) {
eb578fdb 732 OP *kid, *nextkid;
11343788 733 for (kid = cUNOPo->op_first; kid; kid = nextkid) {
1ed44841 734 nextkid = OP_SIBLING(kid); /* Get before next freeing kid */
79072805 735 op_free(kid);
85e6fe83 736 }
79072805 737 }
513f78f7
FC
738 if (type == OP_NULL)
739 type = (OPCODE)o->op_targ;
acb36ea4 740
9e4d7a13
NC
741 if (o->op_slabbed)
742 Slab_to_rw(OpSLAB(o));
fc97af9c 743
acb36ea4
GS
744 /* COP* is not cleared by op_clear() so that we may track line
745 * numbers etc even after null() */
513f78f7 746 if (type == OP_NEXTSTATE || type == OP_DBSTATE) {
acb36ea4 747 cop_free((COP*)o);
3235b7a3 748 }
acb36ea4
GS
749
750 op_clear(o);
238a4c30 751 FreeOp(o);
4d494880
DM
752#ifdef DEBUG_LEAKING_SCALARS
753 if (PL_op == o)
5f66b61c 754 PL_op = NULL;
4d494880 755#endif
acb36ea4 756}
79072805 757
93c66552
DM
758void
759Perl_op_clear(pTHX_ OP *o)
acb36ea4 760{
13137afc 761
27da23d5 762 dVAR;
7918f24d
NC
763
764 PERL_ARGS_ASSERT_OP_CLEAR;
765
11343788 766 switch (o->op_type) {
acb36ea4 767 case OP_NULL: /* Was holding old type, if any. */
c67159e1 768 /* FALLTHROUGH */
4d193d44 769 case OP_ENTERTRY:
acb36ea4 770 case OP_ENTEREVAL: /* Was holding hints. */
acb36ea4 771 o->op_targ = 0;
a0d0e21e 772 break;
a6006777 773 default:
ac4c12e7 774 if (!(o->op_flags & OPf_REF)
ef69c8fc 775 || (PL_check[o->op_type] != Perl_ck_ftst))
a6006777 776 break;
924ba076 777 /* FALLTHROUGH */
463ee0b2 778 case OP_GVSV:
79072805 779 case OP_GV:
a6006777 780 case OP_AELEMFAST:
93bad3fd 781 {
f7461760
Z
782 GV *gv = (o->op_type == OP_GV || o->op_type == OP_GVSV)
783#ifdef USE_ITHREADS
784 && PL_curpad
785#endif
786 ? cGVOPo_gv : NULL;
b327b36f
NC
787 /* It's possible during global destruction that the GV is freed
788 before the optree. Whilst the SvREFCNT_inc is happy to bump from
789 0 to 1 on a freed SV, the corresponding SvREFCNT_dec from 1 to 0
790 will trigger an assertion failure, because the entry to sv_clear
791 checks that the scalar is not already freed. A check of for
792 !SvIS_FREED(gv) turns out to be invalid, because during global
793 destruction the reference count can be forced down to zero
794 (with SVf_BREAK set). In which case raising to 1 and then
795 dropping to 0 triggers cleanup before it should happen. I
796 *think* that this might actually be a general, systematic,
797 weakness of the whole idea of SVf_BREAK, in that code *is*
798 allowed to raise and lower references during global destruction,
799 so any *valid* code that happens to do this during global
800 destruction might well trigger premature cleanup. */
801 bool still_valid = gv && SvREFCNT(gv);
802
803 if (still_valid)
804 SvREFCNT_inc_simple_void(gv);
350de78d 805#ifdef USE_ITHREADS
6a077020 806 if (cPADOPo->op_padix > 0) {
6a077020
DM
807 pad_swipe(cPADOPo->op_padix, TRUE);
808 cPADOPo->op_padix = 0;
809 }
350de78d 810#else
6a077020 811 SvREFCNT_dec(cSVOPo->op_sv);
a0714e2c 812 cSVOPo->op_sv = NULL;
350de78d 813#endif
b327b36f 814 if (still_valid) {
f7461760 815 int try_downgrade = SvREFCNT(gv) == 2;
fc2b2dca 816 SvREFCNT_dec_NN(gv);
f7461760
Z
817 if (try_downgrade)
818 gv_try_downgrade(gv);
819 }
6a077020 820 }
79072805 821 break;
a1ae71d2 822 case OP_METHOD_NAMED:
b46e009d 823 SvREFCNT_dec(cMETHOPx(o)->op_u.op_meth_sv);
824 cMETHOPx(o)->op_u.op_meth_sv = NULL;
825#ifdef USE_ITHREADS
826 if (o->op_targ) {
827 pad_swipe(o->op_targ, 1);
828 o->op_targ = 0;
829 }
830#endif
831 break;
79072805 832 case OP_CONST:
996c9baa 833 case OP_HINTSEVAL:
11343788 834 SvREFCNT_dec(cSVOPo->op_sv);
a0714e2c 835 cSVOPo->op_sv = NULL;
3b1c21fa
AB
836#ifdef USE_ITHREADS
837 /** Bug #15654
838 Even if op_clear does a pad_free for the target of the op,
6a077020 839 pad_free doesn't actually remove the sv that exists in the pad;
3b1c21fa
AB
840 instead it lives on. This results in that it could be reused as
841 a target later on when the pad was reallocated.
842 **/
843 if(o->op_targ) {
844 pad_swipe(o->op_targ,1);
845 o->op_targ = 0;
846 }
847#endif
79072805 848 break;
c9df4fda 849 case OP_DUMP:
748a9306
LW
850 case OP_GOTO:
851 case OP_NEXT:
852 case OP_LAST:
853 case OP_REDO:
11343788 854 if (o->op_flags & (OPf_SPECIAL|OPf_STACKED|OPf_KIDS))
748a9306 855 break;
924ba076 856 /* FALLTHROUGH */
a0d0e21e 857 case OP_TRANS:
bb16bae8 858 case OP_TRANSR:
acb36ea4 859 if (o->op_private & (OPpTRANS_FROM_UTF|OPpTRANS_TO_UTF)) {
99a1d0d1 860 assert(o->op_type == OP_TRANS || o->op_type == OP_TRANSR);
043e41b8
DM
861#ifdef USE_ITHREADS
862 if (cPADOPo->op_padix > 0) {
863 pad_swipe(cPADOPo->op_padix, TRUE);
864 cPADOPo->op_padix = 0;
865 }
866#else
a0ed51b3 867 SvREFCNT_dec(cSVOPo->op_sv);
a0714e2c 868 cSVOPo->op_sv = NULL;
043e41b8 869#endif
acb36ea4
GS
870 }
871 else {
ea71c68d 872 PerlMemShared_free(cPVOPo->op_pv);
bd61b366 873 cPVOPo->op_pv = NULL;
acb36ea4 874 }
a0d0e21e
LW
875 break;
876 case OP_SUBST:
20e98b0f 877 op_free(cPMOPo->op_pmreplrootu.op_pmreplroot);
971a9dd3 878 goto clear_pmop;
748a9306 879 case OP_PUSHRE:
971a9dd3 880#ifdef USE_ITHREADS
20e98b0f 881 if (cPMOPo->op_pmreplrootu.op_pmtargetoff) {
20e98b0f 882 pad_swipe(cPMOPo->op_pmreplrootu.op_pmtargetoff, TRUE);
971a9dd3
GS
883 }
884#else
ad64d0ec 885 SvREFCNT_dec(MUTABLE_SV(cPMOPo->op_pmreplrootu.op_pmtargetgv));
971a9dd3 886#endif
924ba076 887 /* FALLTHROUGH */
a0d0e21e 888 case OP_MATCH:
8782bef2 889 case OP_QR:
971a9dd3 890clear_pmop:
867940b8
DM
891 if (!(cPMOPo->op_pmflags & PMf_CODELIST_PRIVATE))
892 op_free(cPMOPo->op_code_list);
68e2671b 893 cPMOPo->op_code_list = NULL;
23083432 894 forget_pmop(cPMOPo);
20e98b0f 895 cPMOPo->op_pmreplrootu.op_pmreplroot = NULL;
9cddf794
NC
896 /* we use the same protection as the "SAFE" version of the PM_ macros
897 * here since sv_clean_all might release some PMOPs
5f8cb046
DM
898 * after PL_regex_padav has been cleared
899 * and the clearing of PL_regex_padav needs to
900 * happen before sv_clean_all
901 */
13137afc
AB
902#ifdef USE_ITHREADS
903 if(PL_regex_pad) { /* We could be in destruction */
402d2eb1 904 const IV offset = (cPMOPo)->op_pmoffset;
9cddf794 905 ReREFCNT_dec(PM_GETRE(cPMOPo));
402d2eb1
NC
906 PL_regex_pad[offset] = &PL_sv_undef;
907 sv_catpvn_nomg(PL_regex_pad[0], (const char *)&offset,
908 sizeof(offset));
13137afc 909 }
9cddf794
NC
910#else
911 ReREFCNT_dec(PM_GETRE(cPMOPo));
912 PM_SETRE(cPMOPo, NULL);
1eb1540c 913#endif
13137afc 914
a0d0e21e 915 break;
79072805
LW
916 }
917
743e66e6 918 if (o->op_targ > 0) {
11343788 919 pad_free(o->op_targ);
743e66e6
GS
920 o->op_targ = 0;
921 }
79072805
LW
922}
923
76e3520e 924STATIC void
3eb57f73
HS
925S_cop_free(pTHX_ COP* cop)
926{
7918f24d
NC
927 PERL_ARGS_ASSERT_COP_FREE;
928
05ec9bb3 929 CopFILE_free(cop);
0453d815 930 if (! specialWARN(cop->cop_warnings))
72dc9ed5 931 PerlMemShared_free(cop->cop_warnings);
20439bc7 932 cophh_free(CopHINTHASH_get(cop));
515abc43
FC
933 if (PL_curcop == cop)
934 PL_curcop = NULL;
3eb57f73
HS
935}
936
c2b1997a 937STATIC void
c4bd3ae5 938S_forget_pmop(pTHX_ PMOP *const o
c4bd3ae5 939 )
c2b1997a
NC
940{
941 HV * const pmstash = PmopSTASH(o);
7918f24d
NC
942
943 PERL_ARGS_ASSERT_FORGET_PMOP;
944
e39a6381 945 if (pmstash && !SvIS_FREED(pmstash) && SvMAGICAL(pmstash)) {
ad64d0ec 946 MAGIC * const mg = mg_find((const SV *)pmstash, PERL_MAGIC_symtab);
c2b1997a
NC
947 if (mg) {
948 PMOP **const array = (PMOP**) mg->mg_ptr;
949 U32 count = mg->mg_len / sizeof(PMOP**);
950 U32 i = count;
951
952 while (i--) {
953 if (array[i] == o) {
954 /* Found it. Move the entry at the end to overwrite it. */
955 array[i] = array[--count];
956 mg->mg_len = count * sizeof(PMOP**);
957 /* Could realloc smaller at this point always, but probably
958 not worth it. Probably worth free()ing if we're the
959 last. */
960 if(!count) {
961 Safefree(mg->mg_ptr);
962 mg->mg_ptr = NULL;
963 }
964 break;
965 }
966 }
967 }
968 }
1cdf7faf
NC
969 if (PL_curpm == o)
970 PL_curpm = NULL;
c2b1997a
NC
971}
972
bfd0ff22
NC
973STATIC void
974S_find_and_forget_pmops(pTHX_ OP *o)
975{
7918f24d
NC
976 PERL_ARGS_ASSERT_FIND_AND_FORGET_PMOPS;
977
bfd0ff22
NC
978 if (o->op_flags & OPf_KIDS) {
979 OP *kid = cUNOPo->op_first;
980 while (kid) {
981 switch (kid->op_type) {
982 case OP_SUBST:
983 case OP_PUSHRE:
984 case OP_MATCH:
985 case OP_QR:
23083432 986 forget_pmop((PMOP*)kid);
bfd0ff22
NC
987 }
988 find_and_forget_pmops(kid);
1ed44841 989 kid = OP_SIBLING(kid);
bfd0ff22
NC
990 }
991 }
992}
993
6e53b6ca
DD
994/*
995=for apidoc Am|void|op_null|OP *o
996
997Neutralizes an op when it is no longer needed, but is still linked to from
998other ops.
999
1000=cut
1001*/
1002
93c66552
DM
1003void
1004Perl_op_null(pTHX_ OP *o)
8990e307 1005{
27da23d5 1006 dVAR;
7918f24d
NC
1007
1008 PERL_ARGS_ASSERT_OP_NULL;
1009
acb36ea4
GS
1010 if (o->op_type == OP_NULL)
1011 return;
b5bbe64a 1012 op_clear(o);
11343788
MB
1013 o->op_targ = o->op_type;
1014 o->op_type = OP_NULL;
22c35a8c 1015 o->op_ppaddr = PL_ppaddr[OP_NULL];
8990e307
LW
1016}
1017
4026c95a
SH
1018void
1019Perl_op_refcnt_lock(pTHX)
1020{
20b7effb 1021#ifdef USE_ITHREADS
27da23d5 1022 dVAR;
20b7effb 1023#endif
96a5add6 1024 PERL_UNUSED_CONTEXT;
4026c95a
SH
1025 OP_REFCNT_LOCK;
1026}
1027
1028void
1029Perl_op_refcnt_unlock(pTHX)
1030{
20b7effb 1031#ifdef USE_ITHREADS
27da23d5 1032 dVAR;
20b7effb 1033#endif
96a5add6 1034 PERL_UNUSED_CONTEXT;
4026c95a
SH
1035 OP_REFCNT_UNLOCK;
1036}
1037
3253bf85
DM
1038
1039/*
1040=for apidoc op_sibling_splice
1041
1042A general function for editing the structure of an existing chain of
7e234f81 1043op_sibling nodes. By analogy with the perl-level splice() function, allows
3253bf85
DM
1044you to delete zero or more sequential nodes, replacing them with zero or
1045more different nodes. Performs the necessary op_first/op_last
29e61fd9 1046housekeeping on the parent node and op_sibling manipulation on the
7e234f81 1047children. The last deleted node will be marked as as the last node by
8ae26bff 1048updating the op_sibling or op_lastsib field as appropriate.
3253bf85
DM
1049
1050Note that op_next is not manipulated, and nodes are not freed; that is the
7e234f81 1051responsibility of the caller. It also won't create a new list op for an
8ae26bff 1052empty list etc; use higher-level functions like op_append_elem() for that.
3253bf85
DM
1053
1054parent is the parent node of the sibling chain.
1055
7e234f81
FC
1056start is the node preceding the first node to be spliced. Node(s)
1057following it will be deleted, and ops will be inserted after it. If it is
3253bf85
DM
1058NULL, the first node onwards is deleted, and nodes are inserted at the
1059beginning.
1060
7e234f81 1061del_count is the number of nodes to delete. If zero, no nodes are deleted.
3253bf85
DM
1062If -1 or greater than or equal to the number of remaining kids, all
1063remaining kids are deleted.
1064
1065insert is the first of a chain of nodes to be inserted in place of the nodes.
1066If NULL, no nodes are inserted.
1067
8ae26bff 1068The head of the chain of deleted ops is returned, or NULL if no ops were
3253bf85
DM
1069deleted.
1070
1071For example:
1072
1073 action before after returns
1074 ------ ----- ----- -------
1075
1076 P P
8ae26bff
DM
1077 splice(P, A, 2, X-Y-Z) | | B-C
1078 A-B-C-D A-X-Y-Z-D
3253bf85
DM
1079
1080 P P
1081 splice(P, NULL, 1, X-Y) | | A
1082 A-B-C-D X-Y-B-C-D
1083
1084 P P
8ae26bff
DM
1085 splice(P, NULL, 3, NULL) | | A-B-C
1086 A-B-C-D D
3253bf85
DM
1087
1088 P P
1089 splice(P, B, 0, X-Y) | | NULL
1090 A-B-C-D A-B-X-Y-C-D
1091
1092=cut
1093*/
1094
1095OP *
8ae26bff 1096Perl_op_sibling_splice(OP *parent, OP *start, int del_count, OP* insert)
3253bf85 1097{
3253bf85
DM
1098 OP *first = start ? OP_SIBLING(start) : cLISTOPx(parent)->op_first;
1099 OP *rest;
1100 OP *last_del = NULL;
1101 OP *last_ins = NULL;
1102
1103 PERL_ARGS_ASSERT_OP_SIBLING_SPLICE;
1104
1105 assert(del_count >= -1);
1106
1107 if (del_count && first) {
1108 last_del = first;
1109 while (--del_count && OP_HAS_SIBLING(last_del))
1110 last_del = OP_SIBLING(last_del);
1111 rest = OP_SIBLING(last_del);
1112 OP_SIBLING_set(last_del, NULL);
29e61fd9 1113 last_del->op_lastsib = 1;
3253bf85
DM
1114 }
1115 else
1116 rest = first;
1117
1118 if (insert) {
1119 last_ins = insert;
1120 while (OP_HAS_SIBLING(last_ins))
1121 last_ins = OP_SIBLING(last_ins);
1122 OP_SIBLING_set(last_ins, rest);
29e61fd9 1123 last_ins->op_lastsib = rest ? 0 : 1;
3253bf85
DM
1124 }
1125 else
1126 insert = rest;
1127
29e61fd9 1128 if (start) {
3253bf85 1129 OP_SIBLING_set(start, insert);
29e61fd9
DM
1130 start->op_lastsib = insert ? 0 : 1;
1131 }
3253bf85
DM
1132 else
1133 cLISTOPx(parent)->op_first = insert;
1134
1135 if (!rest) {
29e61fd9 1136 /* update op_last etc */
3253bf85 1137 U32 type = parent->op_type;
29e61fd9 1138 OP *lastop;
3253bf85
DM
1139
1140 if (type == OP_NULL)
1141 type = parent->op_targ;
1142 type = PL_opargs[type] & OA_CLASS_MASK;
1143
29e61fd9 1144 lastop = last_ins ? last_ins : start ? start : NULL;
3253bf85
DM
1145 if ( type == OA_BINOP
1146 || type == OA_LISTOP
1147 || type == OA_PMOP
1148 || type == OA_LOOP
1149 )
29e61fd9
DM
1150 cLISTOPx(parent)->op_last = lastop;
1151
1152 if (lastop) {
1153 lastop->op_lastsib = 1;
1154#ifdef PERL_OP_PARENT
1155 lastop->op_sibling = parent;
1156#endif
1157 }
3253bf85
DM
1158 }
1159 return last_del ? first : NULL;
1160}
1161
29e61fd9
DM
1162/*
1163=for apidoc op_parent
1164
7e234f81 1165returns the parent OP of o, if it has a parent. Returns NULL otherwise.
29e61fd9
DM
1166(Currently perl must be built with C<-DPERL_OP_PARENT> for this feature to
1167work.
1168
1169=cut
1170*/
1171
1172OP *
8ae26bff 1173Perl_op_parent(OP *o)
29e61fd9
DM
1174{
1175 PERL_ARGS_ASSERT_OP_PARENT;
1176#ifdef PERL_OP_PARENT
1177 while (OP_HAS_SIBLING(o))
1178 o = OP_SIBLING(o);
1179 return o->op_sibling;
1180#else
1181 PERL_UNUSED_ARG(o);
1182 return NULL;
1183#endif
1184}
1185
3253bf85
DM
1186
1187/* replace the sibling following start with a new UNOP, which becomes
1188 * the parent of the original sibling; e.g.
1189 *
1190 * op_sibling_newUNOP(P, A, unop-args...)
1191 *
1192 * P P
1193 * | becomes |
1194 * A-B-C A-U-C
1195 * |
1196 * B
1197 *
1198 * where U is the new UNOP.
1199 *
1200 * parent and start args are the same as for op_sibling_splice();
1201 * type and flags args are as newUNOP().
1202 *
1203 * Returns the new UNOP.
1204 */
1205
1206OP *
1207S_op_sibling_newUNOP(pTHX_ OP *parent, OP *start, I32 type, I32 flags)
1208{
1209 OP *kid, *newop;
1210
1211 kid = op_sibling_splice(parent, start, 1, NULL);
1212 newop = newUNOP(type, flags, kid);
1213 op_sibling_splice(parent, start, 0, newop);
1214 return newop;
1215}
1216
1217
1218/* lowest-level newLOGOP-style function - just allocates and populates
1219 * the struct. Higher-level stuff should be done by S_new_logop() /
1220 * newLOGOP(). This function exists mainly to avoid op_first assignment
1221 * being spread throughout this file.
1222 */
1223
1224LOGOP *
1225S_alloc_LOGOP(pTHX_ I32 type, OP *first, OP* other)
1226{
1227 LOGOP *logop;
29e61fd9 1228 OP *kid = first;
3253bf85 1229 NewOp(1101, logop, 1, LOGOP);
8ae26bff 1230 logop->op_type = (OPCODE)type;
3253bf85
DM
1231 logop->op_first = first;
1232 logop->op_other = other;
1233 logop->op_flags = OPf_KIDS;
29e61fd9
DM
1234 while (kid && OP_HAS_SIBLING(kid))
1235 kid = OP_SIBLING(kid);
1236 if (kid) {
1237 kid->op_lastsib = 1;
1238#ifdef PERL_OP_PARENT
1239 kid->op_sibling = (OP*)logop;
1240#endif
1241 }
3253bf85
DM
1242 return logop;
1243}
1244
1245
79072805
LW
1246/* Contextualizers */
1247
d9088386
Z
1248/*
1249=for apidoc Am|OP *|op_contextualize|OP *o|I32 context
1250
1251Applies a syntactic context to an op tree representing an expression.
1252I<o> is the op tree, and I<context> must be C<G_SCALAR>, C<G_ARRAY>,
1253or C<G_VOID> to specify the context to apply. The modified op tree
1254is returned.
1255
1256=cut
1257*/
1258
1259OP *
1260Perl_op_contextualize(pTHX_ OP *o, I32 context)
1261{
1262 PERL_ARGS_ASSERT_OP_CONTEXTUALIZE;
1263 switch (context) {
1264 case G_SCALAR: return scalar(o);
1265 case G_ARRAY: return list(o);
1266 case G_VOID: return scalarvoid(o);
1267 default:
5637ef5b
NC
1268 Perl_croak(aTHX_ "panic: op_contextualize bad context %ld",
1269 (long) context);
d9088386
Z
1270 }
1271}
1272
5983a79d 1273/*
79072805 1274
5983a79d 1275=for apidoc Am|OP*|op_linklist|OP *o
72d33970 1276This function is the implementation of the L</LINKLIST> macro. It should
5983a79d
BM
1277not be called directly.
1278
1279=cut
1280*/
1281
1282OP *
1283Perl_op_linklist(pTHX_ OP *o)
79072805 1284{
3edf23ff 1285 OP *first;
79072805 1286
5983a79d 1287 PERL_ARGS_ASSERT_OP_LINKLIST;
7918f24d 1288
11343788
MB
1289 if (o->op_next)
1290 return o->op_next;
79072805
LW
1291
1292 /* establish postfix order */
3edf23ff
AL
1293 first = cUNOPo->op_first;
1294 if (first) {
eb578fdb 1295 OP *kid;
3edf23ff
AL
1296 o->op_next = LINKLIST(first);
1297 kid = first;
1298 for (;;) {
29e61fd9
DM
1299 OP *sibl = OP_SIBLING(kid);
1300 if (sibl) {
1301 kid->op_next = LINKLIST(sibl);
1302 kid = sibl;
3edf23ff 1303 } else {
11343788 1304 kid->op_next = o;
3edf23ff
AL
1305 break;
1306 }
79072805
LW
1307 }
1308 }
1309 else
11343788 1310 o->op_next = o;
79072805 1311
11343788 1312 return o->op_next;
79072805
LW
1313}
1314
1f676739 1315static OP *
2dd5337b 1316S_scalarkids(pTHX_ OP *o)
79072805 1317{
11343788 1318 if (o && o->op_flags & OPf_KIDS) {
bfed75c6 1319 OP *kid;
1ed44841 1320 for (kid = cLISTOPo->op_first; kid; kid = OP_SIBLING(kid))
79072805
LW
1321 scalar(kid);
1322 }
11343788 1323 return o;
79072805
LW
1324}
1325
76e3520e 1326STATIC OP *
cea2e8a9 1327S_scalarboolean(pTHX_ OP *o)
8990e307 1328{
7918f24d
NC
1329 PERL_ARGS_ASSERT_SCALARBOOLEAN;
1330
6b7c6d95
FC
1331 if (o->op_type == OP_SASSIGN && cBINOPo->op_first->op_type == OP_CONST
1332 && !(cBINOPo->op_first->op_flags & OPf_SPECIAL)) {
d008e5eb 1333 if (ckWARN(WARN_SYNTAX)) {
6867be6d 1334 const line_t oldline = CopLINE(PL_curcop);
a0d0e21e 1335
2b7cddde
NC
1336 if (PL_parser && PL_parser->copline != NOLINE) {
1337 /* This ensures that warnings are reported at the first line
1338 of the conditional, not the last. */
53a7735b 1339 CopLINE_set(PL_curcop, PL_parser->copline);
2b7cddde 1340 }
9014280d 1341 Perl_warner(aTHX_ packWARN(WARN_SYNTAX), "Found = in conditional, should be ==");
57843af0 1342 CopLINE_set(PL_curcop, oldline);
d008e5eb 1343 }
a0d0e21e 1344 }
11343788 1345 return scalar(o);
8990e307
LW
1346}
1347
0920b7fa
FC
1348static SV *
1349S_op_varname(pTHX_ const OP *o)
1350{
1351 assert(o);
1352 assert(o->op_type == OP_PADAV || o->op_type == OP_RV2AV ||
1353 o->op_type == OP_PADHV || o->op_type == OP_RV2HV);
1354 {
1355 const char funny = o->op_type == OP_PADAV
1356 || o->op_type == OP_RV2AV ? '@' : '%';
1357 if (o->op_type == OP_RV2AV || o->op_type == OP_RV2HV) {
1358 GV *gv;
1359 if (cUNOPo->op_first->op_type != OP_GV
1360 || !(gv = cGVOPx_gv(cUNOPo->op_first)))
1361 return NULL;
1362 return varname(gv, funny, 0, NULL, 0, 1);
1363 }
1364 return
1365 varname(MUTABLE_GV(PL_compcv), funny, o->op_targ, NULL, 0, 1);
1366 }
1367}
1368
429a2555 1369static void
2186f873
FC
1370S_op_pretty(pTHX_ const OP *o, SV **retsv, const char **retpv)
1371{ /* or not so pretty :-) */
2186f873
FC
1372 if (o->op_type == OP_CONST) {
1373 *retsv = cSVOPo_sv;
1374 if (SvPOK(*retsv)) {
1375 SV *sv = *retsv;
1376 *retsv = sv_newmortal();
1377 pv_pretty(*retsv, SvPVX_const(sv), SvCUR(sv), 32, NULL, NULL,
1378 PERL_PV_PRETTY_DUMP |PERL_PV_ESCAPE_UNI_DETECT);
1379 }
1380 else if (!SvOK(*retsv))
1381 *retpv = "undef";
1382 }
1383 else *retpv = "...";
1384}
1385
1386static void
429a2555
FC
1387S_scalar_slice_warning(pTHX_ const OP *o)
1388{
1389 OP *kid;
1390 const char lbrack =
2186f873 1391 o->op_type == OP_HSLICE ? '{' : '[';
429a2555 1392 const char rbrack =
2186f873 1393 o->op_type == OP_HSLICE ? '}' : ']';
429a2555 1394 SV *name;
32e9ec8f 1395 SV *keysv = NULL; /* just to silence compiler warnings */
429a2555
FC
1396 const char *key = NULL;
1397
1398 if (!(o->op_private & OPpSLICEWARNING))
1399 return;
1400 if (PL_parser && PL_parser->error_count)
1401 /* This warning can be nonsensical when there is a syntax error. */
1402 return;
1403
1404 kid = cLISTOPo->op_first;
1ed44841 1405 kid = OP_SIBLING(kid); /* get past pushmark */
429a2555
FC
1406 /* weed out false positives: any ops that can return lists */
1407 switch (kid->op_type) {
1408 case OP_BACKTICK:
1409 case OP_GLOB:
1410 case OP_READLINE:
1411 case OP_MATCH:
1412 case OP_RV2AV:
1413 case OP_EACH:
1414 case OP_VALUES:
1415 case OP_KEYS:
1416 case OP_SPLIT:
1417 case OP_LIST:
1418 case OP_SORT:
1419 case OP_REVERSE:
1420 case OP_ENTERSUB:
1421 case OP_CALLER:
1422 case OP_LSTAT:
1423 case OP_STAT:
1424 case OP_READDIR:
1425 case OP_SYSTEM:
1426 case OP_TMS:
1427 case OP_LOCALTIME:
1428 case OP_GMTIME:
1429 case OP_ENTEREVAL:
1430 case OP_REACH:
1431 case OP_RKEYS:
1432 case OP_RVALUES:
1433 return;
1434 }
7d3c8a68
SM
1435
1436 /* Don't warn if we have a nulled list either. */
1437 if (kid->op_type == OP_NULL && kid->op_targ == OP_LIST)
1438 return;
1439
1ed44841
DM
1440 assert(OP_SIBLING(kid));
1441 name = S_op_varname(aTHX_ OP_SIBLING(kid));
429a2555
FC
1442 if (!name) /* XS module fiddling with the op tree */
1443 return;
2186f873 1444 S_op_pretty(aTHX_ kid, &keysv, &key);
429a2555
FC
1445 assert(SvPOK(name));
1446 sv_chop(name,SvPVX(name)+1);
1447 if (key)
2186f873 1448 /* diag_listed_as: Scalar value @%s[%s] better written as $%s[%s] */
429a2555 1449 Perl_warner(aTHX_ packWARN(WARN_SYNTAX),
2186f873 1450 "Scalar value @%"SVf"%c%s%c better written as $%"SVf
429a2555 1451 "%c%s%c",
2186f873 1452 SVfARG(name), lbrack, key, rbrack, SVfARG(name),
429a2555
FC
1453 lbrack, key, rbrack);
1454 else
2186f873 1455 /* diag_listed_as: Scalar value @%s[%s] better written as $%s[%s] */
429a2555 1456 Perl_warner(aTHX_ packWARN(WARN_SYNTAX),
2186f873 1457 "Scalar value @%"SVf"%c%"SVf"%c better written as $%"
429a2555 1458 SVf"%c%"SVf"%c",
c1f6cd39
BF
1459 SVfARG(name), lbrack, SVfARG(keysv), rbrack,
1460 SVfARG(name), lbrack, SVfARG(keysv), rbrack);
429a2555
FC
1461}
1462
8990e307 1463OP *
864dbfa3 1464Perl_scalar(pTHX_ OP *o)
79072805
LW
1465{
1466 OP *kid;
1467
a0d0e21e 1468 /* assumes no premature commitment */
13765c85
DM
1469 if (!o || (PL_parser && PL_parser->error_count)
1470 || (o->op_flags & OPf_WANT)
5dc0d613 1471 || o->op_type == OP_RETURN)
7e363e51 1472 {
11343788 1473 return o;
7e363e51 1474 }
79072805 1475
5dc0d613 1476 o->op_flags = (o->op_flags & ~OPf_WANT) | OPf_WANT_SCALAR;
79072805 1477
11343788 1478 switch (o->op_type) {
79072805 1479 case OP_REPEAT:
11343788 1480 scalar(cBINOPo->op_first);
8990e307 1481 break;
79072805
LW
1482 case OP_OR:
1483 case OP_AND:
1484 case OP_COND_EXPR:
1ed44841 1485 for (kid = OP_SIBLING(cUNOPo->op_first); kid; kid = OP_SIBLING(kid))
8990e307 1486 scalar(kid);
79072805 1487 break;
924ba076 1488 /* FALLTHROUGH */
a6d8037e 1489 case OP_SPLIT:
79072805 1490 case OP_MATCH:
8782bef2 1491 case OP_QR:
79072805
LW
1492 case OP_SUBST:
1493 case OP_NULL:
8990e307 1494 default:
11343788 1495 if (o->op_flags & OPf_KIDS) {
1ed44841 1496 for (kid = cUNOPo->op_first; kid; kid = OP_SIBLING(kid))
8990e307
LW
1497 scalar(kid);
1498 }
79072805
LW
1499 break;
1500 case OP_LEAVE:
1501 case OP_LEAVETRY:
5dc0d613 1502 kid = cLISTOPo->op_first;
54310121 1503 scalar(kid);
1ed44841 1504 kid = OP_SIBLING(kid);
25b991bf
VP
1505 do_kids:
1506 while (kid) {
1ed44841 1507 OP *sib = OP_SIBLING(kid);
c08f093b
VP
1508 if (sib && kid->op_type != OP_LEAVEWHEN)
1509 scalarvoid(kid);
1510 else
54310121 1511 scalar(kid);
25b991bf 1512 kid = sib;
54310121 1513 }
11206fdd 1514 PL_curcop = &PL_compiling;
54310121 1515 break;
748a9306 1516 case OP_SCOPE:
79072805 1517 case OP_LINESEQ:
8990e307 1518 case OP_LIST:
25b991bf
VP
1519 kid = cLISTOPo->op_first;
1520 goto do_kids;
a801c63c 1521 case OP_SORT:
a2a5de95 1522 Perl_ck_warner(aTHX_ packWARN(WARN_VOID), "Useless use of sort in scalar context");
553e7bb0 1523 break;
95a31aad
FC
1524 case OP_KVHSLICE:
1525 case OP_KVASLICE:
2186f873
FC
1526 {
1527 /* Warn about scalar context */
1528 const char lbrack = o->op_type == OP_KVHSLICE ? '{' : '[';
1529 const char rbrack = o->op_type == OP_KVHSLICE ? '}' : ']';
1530 SV *name;
1531 SV *keysv;
1532 const char *key = NULL;
1533
1534 /* This warning can be nonsensical when there is a syntax error. */
1535 if (PL_parser && PL_parser->error_count)
1536 break;
1537
1538 if (!ckWARN(WARN_SYNTAX)) break;
1539
1540 kid = cLISTOPo->op_first;
1ed44841
DM
1541 kid = OP_SIBLING(kid); /* get past pushmark */
1542 assert(OP_SIBLING(kid));
1543 name = S_op_varname(aTHX_ OP_SIBLING(kid));
2186f873
FC
1544 if (!name) /* XS module fiddling with the op tree */
1545 break;
1546 S_op_pretty(aTHX_ kid, &keysv, &key);
1547 assert(SvPOK(name));
1548 sv_chop(name,SvPVX(name)+1);
1549 if (key)
1550 /* diag_listed_as: %%s[%s] in scalar context better written as $%s[%s] */
1551 Perl_warner(aTHX_ packWARN(WARN_SYNTAX),
1552 "%%%"SVf"%c%s%c in scalar context better written "
1553 "as $%"SVf"%c%s%c",
1554 SVfARG(name), lbrack, key, rbrack, SVfARG(name),
1555 lbrack, key, rbrack);
1556 else
1557 /* diag_listed_as: %%s[%s] in scalar context better written as $%s[%s] */
1558 Perl_warner(aTHX_ packWARN(WARN_SYNTAX),
1559 "%%%"SVf"%c%"SVf"%c in scalar context better "
1560 "written as $%"SVf"%c%"SVf"%c",
c1f6cd39
BF
1561 SVfARG(name), lbrack, SVfARG(keysv), rbrack,
1562 SVfARG(name), lbrack, SVfARG(keysv), rbrack);
2186f873 1563 }
79072805 1564 }
11343788 1565 return o;
79072805
LW
1566}
1567
1568OP *
864dbfa3 1569Perl_scalarvoid(pTHX_ OP *o)
79072805 1570{
27da23d5 1571 dVAR;
79072805 1572 OP *kid;
095b19d1 1573 SV *useless_sv = NULL;
c445ea15 1574 const char* useless = NULL;
8990e307 1575 SV* sv;
2ebea0a1
GS
1576 U8 want;
1577
7918f24d
NC
1578 PERL_ARGS_ASSERT_SCALARVOID;
1579
acb36ea4 1580 if (o->op_type == OP_NEXTSTATE
acb36ea4
GS
1581 || o->op_type == OP_DBSTATE
1582 || (o->op_type == OP_NULL && (o->op_targ == OP_NEXTSTATE
acb36ea4 1583 || o->op_targ == OP_DBSTATE)))
2ebea0a1 1584 PL_curcop = (COP*)o; /* for warning below */
79072805 1585
54310121 1586 /* assumes no premature commitment */
2ebea0a1 1587 want = o->op_flags & OPf_WANT;
13765c85
DM
1588 if ((want && want != OPf_WANT_SCALAR)
1589 || (PL_parser && PL_parser->error_count)
25b991bf 1590 || o->op_type == OP_RETURN || o->op_type == OP_REQUIRE || o->op_type == OP_LEAVEWHEN)
7e363e51 1591 {
11343788 1592 return o;
7e363e51 1593 }
79072805 1594
b162f9ea 1595 if ((o->op_private & OPpTARGET_MY)
7e363e51
GS
1596 && (PL_opargs[o->op_type] & OA_TARGLEX))/* OPp share the meaning */
1597 {
b162f9ea 1598 return scalar(o); /* As if inside SASSIGN */
7e363e51 1599 }
1c846c1f 1600
5dc0d613 1601 o->op_flags = (o->op_flags & ~OPf_WANT) | OPf_WANT_VOID;
79072805 1602
11343788 1603 switch (o->op_type) {
79072805 1604 default:
22c35a8c 1605 if (!(PL_opargs[o->op_type] & OA_FOLDCONST))
8990e307 1606 break;
924ba076 1607 /* FALLTHROUGH */
36477c24 1608 case OP_REPEAT:
11343788 1609 if (o->op_flags & OPf_STACKED)
8990e307 1610 break;
5d82c453
GA
1611 goto func_ops;
1612 case OP_SUBSTR:
1613 if (o->op_private == 4)
1614 break;
924ba076 1615 /* FALLTHROUGH */
8990e307
LW
1616 case OP_GVSV:
1617 case OP_WANTARRAY:
1618 case OP_GV:
74295f0b 1619 case OP_SMARTMATCH:
8990e307
LW
1620 case OP_PADSV:
1621 case OP_PADAV:
1622 case OP_PADHV:
1623 case OP_PADANY:
1624 case OP_AV2ARYLEN:
8990e307 1625 case OP_REF:
a0d0e21e
LW
1626 case OP_REFGEN:
1627 case OP_SREFGEN:
8990e307
LW
1628 case OP_DEFINED:
1629 case OP_HEX:
1630 case OP_OCT:
1631 case OP_LENGTH:
8990e307
LW
1632 case OP_VEC:
1633 case OP_INDEX:
1634 case OP_RINDEX:
1635 case OP_SPRINTF:
1636 case OP_AELEM:
1637 case OP_AELEMFAST:
93bad3fd 1638 case OP_AELEMFAST_LEX:
8990e307 1639 case OP_ASLICE:
6dd3e0f2 1640 case OP_KVASLICE:
8990e307
LW
1641 case OP_HELEM:
1642 case OP_HSLICE:
5cae3edb 1643 case OP_KVHSLICE:
8990e307
LW
1644 case OP_UNPACK:
1645 case OP_PACK:
8990e307
LW
1646 case OP_JOIN:
1647 case OP_LSLICE:
1648 case OP_ANONLIST:
1649 case OP_ANONHASH:
1650 case OP_SORT:
1651 case OP_REVERSE:
1652 case OP_RANGE:
1653 case OP_FLIP:
1654 case OP_FLOP:
1655 case OP_CALLER:
1656 case OP_FILENO:
1657 case OP_EOF:
1658 case OP_TELL:
1659 case OP_GETSOCKNAME:
1660 case OP_GETPEERNAME:
1661 case OP_READLINK:
1662 case OP_TELLDIR:
1663 case OP_GETPPID:
1664 case OP_GETPGRP:
1665 case OP_GETPRIORITY:
1666 case OP_TIME:
1667 case OP_TMS:
1668 case OP_LOCALTIME:
1669 case OP_GMTIME:
1670 case OP_GHBYNAME:
1671 case OP_GHBYADDR:
1672 case OP_GHOSTENT:
1673 case OP_GNBYNAME:
1674 case OP_GNBYADDR:
1675 case OP_GNETENT:
1676 case OP_GPBYNAME:
1677 case OP_GPBYNUMBER:
1678 case OP_GPROTOENT:
1679 case OP_GSBYNAME:
1680 case OP_GSBYPORT:
1681 case OP_GSERVENT:
1682 case OP_GPWNAM:
1683 case OP_GPWUID:
1684 case OP_GGRNAM:
1685 case OP_GGRGID:
1686 case OP_GETLOGIN:
78e1b766 1687 case OP_PROTOTYPE:
703227f5 1688 case OP_RUNCV:
5d82c453 1689 func_ops:
64aac5a9 1690 if (!(o->op_private & (OPpLVAL_INTRO|OPpOUR_INTRO)))
74295f0b 1691 /* Otherwise it's "Useless use of grep iterator" */
f5df4782 1692 useless = OP_DESC(o);
75068674
RGS
1693 break;
1694
1695 case OP_SPLIT:
1696 kid = cLISTOPo->op_first;
1697 if (kid && kid->op_type == OP_PUSHRE
fd017c00 1698 && !kid->op_targ
ef7999f1 1699 && !(o->op_flags & OPf_STACKED)
75068674
RGS
1700#ifdef USE_ITHREADS
1701 && !((PMOP*)kid)->op_pmreplrootu.op_pmtargetoff)
1702#else
1703 && !((PMOP*)kid)->op_pmreplrootu.op_pmtargetgv)
1704#endif
1705 useless = OP_DESC(o);
8990e307
LW
1706 break;
1707
9f82cd5f
YST
1708 case OP_NOT:
1709 kid = cUNOPo->op_first;
1710 if (kid->op_type != OP_MATCH && kid->op_type != OP_SUBST &&
bb16bae8 1711 kid->op_type != OP_TRANS && kid->op_type != OP_TRANSR) {
9f82cd5f
YST
1712 goto func_ops;
1713 }
1714 useless = "negative pattern binding (!~)";
1715 break;
1716
4f4d7508
DC
1717 case OP_SUBST:
1718 if (cPMOPo->op_pmflags & PMf_NONDESTRUCT)
8db9069c 1719 useless = "non-destructive substitution (s///r)";
4f4d7508
DC
1720 break;
1721
bb16bae8
FC
1722 case OP_TRANSR:
1723 useless = "non-destructive transliteration (tr///r)";
1724 break;
1725
8990e307
LW
1726 case OP_RV2GV:
1727 case OP_RV2SV:
1728 case OP_RV2AV:
1729 case OP_RV2HV:
192587c2 1730 if (!(o->op_private & (OPpLVAL_INTRO|OPpOUR_INTRO)) &&
1ed44841 1731 (!OP_HAS_SIBLING(o) || OP_SIBLING(o)->op_type != OP_READLINE))
8990e307
LW
1732 useless = "a variable";
1733 break;
79072805
LW
1734
1735 case OP_CONST:
7766f137 1736 sv = cSVOPo_sv;
7a52d87a
GS
1737 if (cSVOPo->op_private & OPpCONST_STRICT)
1738 no_bareword_allowed(o);
1739 else {
d008e5eb 1740 if (ckWARN(WARN_VOID)) {
365c7d0c 1741 NV nv;
e7fec78e 1742 /* don't warn on optimised away booleans, eg
b5a930ec 1743 * use constant Foo, 5; Foo || print; */
e7fec78e 1744 if (cSVOPo->op_private & OPpCONST_SHORTCIRCUIT)
d4c19fe8 1745 useless = NULL;
960b4253
MG
1746 /* the constants 0 and 1 are permitted as they are
1747 conventionally used as dummies in constructs like
1748 1 while some_condition_with_side_effects; */
365c7d0c 1749 else if (SvNIOK(sv) && ((nv = SvNV(sv)) == 0.0 || nv == 1.0))
d4c19fe8 1750 useless = NULL;
d008e5eb 1751 else if (SvPOK(sv)) {
1e3f3188
KW
1752 SV * const dsv = newSVpvs("");
1753 useless_sv
1754 = Perl_newSVpvf(aTHX_
1755 "a constant (%s)",
1756 pv_pretty(dsv, SvPVX_const(sv),
1757 SvCUR(sv), 32, NULL, NULL,
1758 PERL_PV_PRETTY_DUMP
1759 | PERL_PV_ESCAPE_NOCLEAR
1760 | PERL_PV_ESCAPE_UNI_DETECT));
1761 SvREFCNT_dec_NN(dsv);
d008e5eb 1762 }
919f76a3 1763 else if (SvOK(sv)) {
c1f6cd39 1764 useless_sv = Perl_newSVpvf(aTHX_ "a constant (%"SVf")", SVfARG(sv));
919f76a3
RGS
1765 }
1766 else
1767 useless = "a constant (undef)";
8990e307
LW
1768 }
1769 }
93c66552 1770 op_null(o); /* don't execute or even remember it */
79072805
LW
1771 break;
1772
1773 case OP_POSTINC:
11343788 1774 o->op_type = OP_PREINC; /* pre-increment is faster */
22c35a8c 1775 o->op_ppaddr = PL_ppaddr[OP_PREINC];
79072805
LW
1776 break;
1777
1778 case OP_POSTDEC:
11343788 1779 o->op_type = OP_PREDEC; /* pre-decrement is faster */
22c35a8c 1780 o->op_ppaddr = PL_ppaddr[OP_PREDEC];
79072805
LW
1781 break;
1782
679d6c4e
HS
1783 case OP_I_POSTINC:
1784 o->op_type = OP_I_PREINC; /* pre-increment is faster */
1785 o->op_ppaddr = PL_ppaddr[OP_I_PREINC];
1786 break;
1787
1788 case OP_I_POSTDEC:
1789 o->op_type = OP_I_PREDEC; /* pre-decrement is faster */
1790 o->op_ppaddr = PL_ppaddr[OP_I_PREDEC];
1791 break;
1792
f2f8fd84
GG
1793 case OP_SASSIGN: {
1794 OP *rv2gv;
1795 UNOP *refgen, *rv2cv;
1796 LISTOP *exlist;
1797
1798 if ((o->op_private & ~OPpASSIGN_BACKWARDS) != 2)
1799 break;
1800
1801 rv2gv = ((BINOP *)o)->op_last;
1802 if (!rv2gv || rv2gv->op_type != OP_RV2GV)
1803 break;
1804
1805 refgen = (UNOP *)((BINOP *)o)->op_first;
1806
18690b0b
FC
1807 if (!refgen || (refgen->op_type != OP_REFGEN
1808 && refgen->op_type != OP_SREFGEN))
f2f8fd84
GG
1809 break;
1810
1811 exlist = (LISTOP *)refgen->op_first;
1812 if (!exlist || exlist->op_type != OP_NULL
1813 || exlist->op_targ != OP_LIST)
1814 break;
1815
18690b0b
FC
1816 if (exlist->op_first->op_type != OP_PUSHMARK
1817 && exlist->op_first != exlist->op_last)
f2f8fd84
GG
1818 break;
1819
1820 rv2cv = (UNOP*)exlist->op_last;
1821
1822 if (rv2cv->op_type != OP_RV2CV)
1823 break;
1824
1825 assert ((rv2gv->op_private & OPpDONT_INIT_GV) == 0);
1826 assert ((o->op_private & OPpASSIGN_CV_TO_GV) == 0);
1827 assert ((rv2cv->op_private & OPpMAY_RETURN_CONSTANT) == 0);
1828
1829 o->op_private |= OPpASSIGN_CV_TO_GV;
1830 rv2gv->op_private |= OPpDONT_INIT_GV;
1831 rv2cv->op_private |= OPpMAY_RETURN_CONSTANT;
1832
1833 break;
1834 }
1835
540dd770
GG
1836 case OP_AASSIGN: {
1837 inplace_aassign(o);
1838 break;
1839 }
1840
79072805
LW
1841 case OP_OR:
1842 case OP_AND:
edbe35ea
VP
1843 kid = cLOGOPo->op_first;
1844 if (kid->op_type == OP_NOT
b5bbe64a 1845 && (kid->op_flags & OPf_KIDS)) {
edbe35ea
VP
1846 if (o->op_type == OP_AND) {
1847 o->op_type = OP_OR;
1848 o->op_ppaddr = PL_ppaddr[OP_OR];
1849 } else {
1850 o->op_type = OP_AND;
1851 o->op_ppaddr = PL_ppaddr[OP_AND];
1852 }
1853 op_null(kid);
1854 }
c67159e1 1855 /* FALLTHROUGH */
edbe35ea 1856
c963b151 1857 case OP_DOR:
79072805 1858 case OP_COND_EXPR:
0d863452
RH
1859 case OP_ENTERGIVEN:
1860 case OP_ENTERWHEN:
1ed44841 1861 for (kid = OP_SIBLING(cUNOPo->op_first); kid; kid = OP_SIBLING(kid))
79072805
LW
1862 scalarvoid(kid);
1863 break;
5aabfad6 1864
a0d0e21e 1865 case OP_NULL:
11343788 1866 if (o->op_flags & OPf_STACKED)
a0d0e21e 1867 break;
924ba076 1868 /* FALLTHROUGH */
2ebea0a1
GS
1869 case OP_NEXTSTATE:
1870 case OP_DBSTATE:
79072805
LW
1871 case OP_ENTERTRY:
1872 case OP_ENTER:
11343788 1873 if (!(o->op_flags & OPf_KIDS))
79072805 1874 break;
924ba076 1875 /* FALLTHROUGH */
463ee0b2 1876 case OP_SCOPE:
79072805
LW
1877 case OP_LEAVE:
1878 case OP_LEAVETRY:
a0d0e21e 1879 case OP_LEAVELOOP:
79072805 1880 case OP_LINESEQ:
79072805 1881 case OP_LIST:
0d863452
RH
1882 case OP_LEAVEGIVEN:
1883 case OP_LEAVEWHEN:
1ed44841 1884 for (kid = cLISTOPo->op_first; kid; kid = OP_SIBLING(kid))
79072805
LW
1885 scalarvoid(kid);
1886 break;
c90c0ff4 1887 case OP_ENTEREVAL:
5196be3e 1888 scalarkids(o);
c90c0ff4 1889 break;
d6483035 1890 case OP_SCALAR:
5196be3e 1891 return scalar(o);
79072805 1892 }
095b19d1
NC
1893
1894 if (useless_sv) {
1895 /* mortalise it, in case warnings are fatal. */
1896 Perl_ck_warner(aTHX_ packWARN(WARN_VOID),
1897 "Useless use of %"SVf" in void context",
c1f6cd39 1898 SVfARG(sv_2mortal(useless_sv)));
095b19d1
NC
1899 }
1900 else if (useless) {
1901 Perl_ck_warner(aTHX_ packWARN(WARN_VOID),
1902 "Useless use of %s in void context",
1903 useless);
1904 }
11343788 1905 return o;
79072805
LW
1906}
1907
1f676739 1908static OP *
412da003 1909S_listkids(pTHX_ OP *o)
79072805 1910{
11343788 1911 if (o && o->op_flags & OPf_KIDS) {
6867be6d 1912 OP *kid;
1ed44841 1913 for (kid = cLISTOPo->op_first; kid; kid = OP_SIBLING(kid))
79072805
LW
1914 list(kid);
1915 }
11343788 1916 return o;
79072805
LW
1917}
1918
1919OP *
864dbfa3 1920Perl_list(pTHX_ OP *o)
79072805
LW
1921{
1922 OP *kid;
1923
a0d0e21e 1924 /* assumes no premature commitment */
13765c85
DM
1925 if (!o || (o->op_flags & OPf_WANT)
1926 || (PL_parser && PL_parser->error_count)
5dc0d613 1927 || o->op_type == OP_RETURN)
7e363e51 1928 {
11343788 1929 return o;
7e363e51 1930 }
79072805 1931
b162f9ea 1932 if ((o->op_private & OPpTARGET_MY)
7e363e51
GS
1933 && (PL_opargs[o->op_type] & OA_TARGLEX))/* OPp share the meaning */
1934 {
b162f9ea 1935 return o; /* As if inside SASSIGN */
7e363e51 1936 }
1c846c1f 1937
5dc0d613 1938 o->op_flags = (o->op_flags & ~OPf_WANT) | OPf_WANT_LIST;
79072805 1939
11343788 1940 switch (o->op_type) {
79072805
LW
1941 case OP_FLOP:
1942 case OP_REPEAT:
11343788 1943 list(cBINOPo->op_first);
79072805
LW
1944 break;
1945 case OP_OR:
1946 case OP_AND:
1947 case OP_COND_EXPR:
1ed44841 1948 for (kid = OP_SIBLING(cUNOPo->op_first); kid; kid = OP_SIBLING(kid))
79072805
LW
1949 list(kid);
1950 break;
1951 default:
1952 case OP_MATCH:
8782bef2 1953 case OP_QR:
79072805
LW
1954 case OP_SUBST:
1955 case OP_NULL:
11343788 1956 if (!(o->op_flags & OPf_KIDS))
79072805 1957 break;
11343788
MB
1958 if (!o->op_next && cUNOPo->op_first->op_type == OP_FLOP) {
1959 list(cBINOPo->op_first);
1960 return gen_constant_list(o);
79072805
LW
1961 }
1962 case OP_LIST:
11343788 1963 listkids(o);
79072805
LW
1964 break;
1965 case OP_LEAVE:
1966 case OP_LEAVETRY:
5dc0d613 1967 kid = cLISTOPo->op_first;
54310121 1968 list(kid);
1ed44841 1969 kid = OP_SIBLING(kid);
25b991bf
VP
1970 do_kids:
1971 while (kid) {
1ed44841 1972 OP *sib = OP_SIBLING(kid);
c08f093b
VP
1973 if (sib && kid->op_type != OP_LEAVEWHEN)
1974 scalarvoid(kid);
1975 else
54310121 1976 list(kid);
25b991bf 1977 kid = sib;
54310121 1978 }
11206fdd 1979 PL_curcop = &PL_compiling;
54310121 1980 break;
748a9306 1981 case OP_SCOPE:
79072805 1982 case OP_LINESEQ:
25b991bf
VP
1983 kid = cLISTOPo->op_first;
1984 goto do_kids;
79072805 1985 }
11343788 1986 return o;
79072805
LW
1987}
1988
1f676739 1989static OP *
2dd5337b 1990S_scalarseq(pTHX_ OP *o)
79072805 1991{
11343788 1992 if (o) {
1496a290
AL
1993 const OPCODE type = o->op_type;
1994
1995 if (type == OP_LINESEQ || type == OP_SCOPE ||
1996 type == OP_LEAVE || type == OP_LEAVETRY)
463ee0b2 1997 {
6867be6d 1998 OP *kid;
1ed44841
DM
1999 for (kid = cLISTOPo->op_first; kid; kid = OP_SIBLING(kid)) {
2000 if (OP_HAS_SIBLING(kid)) {
463ee0b2 2001 scalarvoid(kid);
ed6116ce 2002 }
463ee0b2 2003 }
3280af22 2004 PL_curcop = &PL_compiling;
79072805 2005 }
11343788 2006 o->op_flags &= ~OPf_PARENS;
3280af22 2007 if (PL_hints & HINT_BLOCK_SCOPE)
11343788 2008 o->op_flags |= OPf_PARENS;
79072805 2009 }
8990e307 2010 else
11343788
MB
2011 o = newOP(OP_STUB, 0);
2012 return o;
79072805
LW
2013}
2014
76e3520e 2015STATIC OP *
cea2e8a9 2016S_modkids(pTHX_ OP *o, I32 type)
79072805 2017{
11343788 2018 if (o && o->op_flags & OPf_KIDS) {
6867be6d 2019 OP *kid;
1ed44841 2020 for (kid = cLISTOPo->op_first; kid; kid = OP_SIBLING(kid))
3ad73efd 2021 op_lvalue(kid, type);
79072805 2022 }
11343788 2023 return o;
79072805
LW
2024}
2025
3ad73efd 2026/*
d164302a
GG
2027=for apidoc finalize_optree
2028
72d33970
FC
2029This function finalizes the optree. Should be called directly after
2030the complete optree is built. It does some additional
d164302a
GG
2031checking which can't be done in the normal ck_xxx functions and makes
2032the tree thread-safe.
2033
2034=cut
2035*/
2036void
2037Perl_finalize_optree(pTHX_ OP* o)
2038{
2039 PERL_ARGS_ASSERT_FINALIZE_OPTREE;
2040
2041 ENTER;
2042 SAVEVPTR(PL_curcop);
2043
2044 finalize_op(o);
2045
2046 LEAVE;
2047}
2048
b46e009d 2049#ifdef USE_ITHREADS
2050/* Relocate sv to the pad for thread safety.
2051 * Despite being a "constant", the SV is written to,
2052 * for reference counts, sv_upgrade() etc. */
2053PERL_STATIC_INLINE void
2054S_op_relocate_sv(pTHX_ SV** svp, PADOFFSET* targp)
2055{
2056 PADOFFSET ix;
2057 PERL_ARGS_ASSERT_OP_RELOCATE_SV;
2058 if (!*svp) return;
2059 ix = pad_alloc(OP_CONST, SVf_READONLY);
2060 SvREFCNT_dec(PAD_SVl(ix));
2061 PAD_SETSV(ix, *svp);
2062 /* XXX I don't know how this isn't readonly already. */
2063 if (!SvIsCOW(PAD_SVl(ix))) SvREADONLY_on(PAD_SVl(ix));
2064 *svp = NULL;
2065 *targp = ix;
2066}
2067#endif
2068
2069
60dde6b2 2070STATIC void
d164302a
GG
2071S_finalize_op(pTHX_ OP* o)
2072{
2073 PERL_ARGS_ASSERT_FINALIZE_OP;
2074
d164302a
GG
2075
2076 switch (o->op_type) {
2077 case OP_NEXTSTATE:
2078 case OP_DBSTATE:
2079 PL_curcop = ((COP*)o); /* for warnings */
2080 break;
2081 case OP_EXEC:
1ed44841
DM
2082 if (OP_HAS_SIBLING(o)) {
2083 OP *sib = OP_SIBLING(o);
2084 if (( sib->op_type == OP_NEXTSTATE || sib->op_type == OP_DBSTATE)
2085 && ckWARN(WARN_EXEC)
2086 && OP_HAS_SIBLING(sib))
2087 {
2088 const OPCODE type = OP_SIBLING(sib)->op_type;
d164302a
GG
2089 if (type != OP_EXIT && type != OP_WARN && type != OP_DIE) {
2090 const line_t oldline = CopLINE(PL_curcop);
1ed44841 2091 CopLINE_set(PL_curcop, CopLINE((COP*)sib));
d164302a
GG
2092 Perl_warner(aTHX_ packWARN(WARN_EXEC),
2093 "Statement unlikely to be reached");
2094 Perl_warner(aTHX_ packWARN(WARN_EXEC),
2095 "\t(Maybe you meant system() when you said exec()?)\n");
2096 CopLINE_set(PL_curcop, oldline);
2097 }
d164302a 2098 }
1ed44841 2099 }
d164302a
GG
2100 break;
2101
2102 case OP_GV:
2103 if ((o->op_private & OPpEARLY_CV) && ckWARN(WARN_PROTOTYPE)) {
2104 GV * const gv = cGVOPo_gv;
2105 if (SvTYPE(gv) == SVt_PVGV && GvCV(gv) && SvPVX_const(GvCV(gv))) {
2106 /* XXX could check prototype here instead of just carping */
2107 SV * const sv = sv_newmortal();
2108 gv_efullname3(sv, gv, NULL);
2109 Perl_warner(aTHX_ packWARN(WARN_PROTOTYPE),
2110 "%"SVf"() called too early to check prototype",
2111 SVfARG(sv));
2112 }
2113 }
2114 break;
2115
2116 case OP_CONST:
eb796c7f
GG
2117 if (cSVOPo->op_private & OPpCONST_STRICT)
2118 no_bareword_allowed(o);
2119 /* FALLTHROUGH */
d164302a
GG
2120#ifdef USE_ITHREADS
2121 case OP_HINTSEVAL:
b46e009d 2122 op_relocate_sv(&cSVOPo->op_sv, &o->op_targ);
2123#endif
2124 break;
2125
2126#ifdef USE_ITHREADS
2127 /* Relocate all the METHOP's SVs to the pad for thread safety. */
d164302a 2128 case OP_METHOD_NAMED:
b46e009d 2129 op_relocate_sv(&cMETHOPx(o)->op_u.op_meth_sv, &o->op_targ);
2130 break;
d164302a 2131#endif
d164302a
GG
2132
2133 case OP_HELEM: {
2134 UNOP *rop;
2135 SV *lexname;
2136 GV **fields;
565e6f7e
FC
2137 SVOP *key_op;
2138 OP *kid;
2139 bool check_fields;
d164302a 2140
565e6f7e 2141 if ((key_op = cSVOPx(((BINOP*)o)->op_last))->op_type != OP_CONST)
d164302a
GG
2142 break;
2143
2144 rop = (UNOP*)((BINOP*)o)->op_first;
e6307ed0 2145
565e6f7e 2146 goto check_keys;
d164302a 2147
565e6f7e 2148 case OP_HSLICE:
429a2555 2149 S_scalar_slice_warning(aTHX_ o);
c67159e1 2150 /* FALLTHROUGH */
429a2555 2151
c5f75dba 2152 case OP_KVHSLICE:
1ed44841 2153 kid = OP_SIBLING(cLISTOPo->op_first);
71323522 2154 if (/* I bet there's always a pushmark... */
7d3c8a68
SM
2155 OP_TYPE_ISNT_AND_WASNT_NN(kid, OP_LIST)
2156 && OP_TYPE_ISNT_NN(kid, OP_CONST))
2157 {
d164302a 2158 break;
7d3c8a68 2159 }
565e6f7e
FC
2160
2161 key_op = (SVOP*)(kid->op_type == OP_CONST
2162 ? kid
1ed44841 2163 : OP_SIBLING(kLISTOP->op_first));
565e6f7e
FC
2164
2165 rop = (UNOP*)((LISTOP*)o)->op_last;
2166
2167 check_keys:
2168 if (o->op_private & OPpLVAL_INTRO || rop->op_type != OP_RV2HV)
71323522 2169 rop = NULL;
565e6f7e 2170 else if (rop->op_first->op_type == OP_PADSV)
d164302a
GG
2171 /* @$hash{qw(keys here)} */
2172 rop = (UNOP*)rop->op_first;
565e6f7e 2173 else {
d164302a
GG
2174 /* @{$hash}{qw(keys here)} */
2175 if (rop->op_first->op_type == OP_SCOPE
2176 && cLISTOPx(rop->op_first)->op_last->op_type == OP_PADSV)
2177 {
2178 rop = (UNOP*)cLISTOPx(rop->op_first)->op_last;
2179 }
2180 else
71323522 2181 rop = NULL;
d164302a 2182 }
71323522 2183
32e9ec8f 2184 lexname = NULL; /* just to silence compiler warnings */
03acb648
DM
2185 fields = NULL; /* just to silence compiler warnings */
2186
71323522
FC
2187 check_fields =
2188 rop
2189 && (lexname = *av_fetch(PL_comppad_name, rop->op_targ, TRUE),
2190 SvPAD_TYPED(lexname))
2191 && (fields = (GV**)hv_fetchs(SvSTASH(lexname), "FIELDS", FALSE))
2192 && isGV(*fields) && GvHV(*fields);
0e706dd4 2193 for (; key_op;
1ed44841 2194 key_op = (SVOP*)OP_SIBLING(key_op)) {
565e6f7e 2195 SV **svp, *sv;
d164302a
GG
2196 if (key_op->op_type != OP_CONST)
2197 continue;
2198 svp = cSVOPx_svp(key_op);
71323522
FC
2199
2200 /* Make the CONST have a shared SV */
2201 if ((!SvIsCOW_shared_hash(sv = *svp))
2202 && SvTYPE(sv) < SVt_PVMG && SvOK(sv) && !SvROK(sv)) {
2203 SSize_t keylen;
2204 const char * const key = SvPV_const(sv, *(STRLEN*)&keylen);
2205 SV *nsv = newSVpvn_share(key,
2206 SvUTF8(sv) ? -keylen : keylen, 0);
2207 SvREFCNT_dec_NN(sv);
2208 *svp = nsv;
2209 }
2210
2211 if (check_fields
2212 && !hv_fetch_ent(GvHV(*fields), *svp, FALSE, 0)) {
ce16c625 2213 Perl_croak(aTHX_ "No such class field \"%"SVf"\" "
84cf752c 2214 "in variable %"SVf" of type %"HEKf,
ce16c625 2215 SVfARG(*svp), SVfARG(lexname),
84cf752c 2216 HEKfARG(HvNAME_HEK(SvSTASH(lexname))));
d164302a
GG
2217 }
2218 }
2219 break;
2220 }
429a2555
FC
2221 case OP_ASLICE:
2222 S_scalar_slice_warning(aTHX_ o);
2223 break;
a7fd8ef6 2224
d164302a
GG
2225 case OP_SUBST: {
2226 if (cPMOPo->op_pmreplrootu.op_pmreplroot)
2227 finalize_op(cPMOPo->op_pmreplrootu.op_pmreplroot);
2228 break;
2229 }
2230 default:
2231 break;
2232 }
2233
2234 if (o->op_flags & OPf_KIDS) {
2235 OP *kid;
c4b20975
DM
2236
2237#ifdef DEBUGGING
20220689
DM
2238 /* check that op_last points to the last sibling, and that
2239 * the last op_sibling field points back to the parent, and
2240 * that the only ops with KIDS are those which are entitled to
2241 * them */
c4b20975
DM
2242 U32 type = o->op_type;
2243 U32 family;
20220689 2244 bool has_last;
c4b20975
DM
2245
2246 if (type == OP_NULL) {
2247 type = o->op_targ;
2248 /* ck_glob creates a null UNOP with ex-type GLOB
2249 * (which is a list op. So pretend it wasn't a listop */
2250 if (type == OP_GLOB)
2251 type = OP_NULL;
2252 }
2253 family = PL_opargs[type] & OA_CLASS_MASK;
2254
20220689
DM
2255 has_last = ( family == OA_BINOP
2256 || family == OA_LISTOP
2257 || family == OA_PMOP
2258 || family == OA_LOOP
2259 );
2260 assert( has_last /* has op_first and op_last, or ...
2261 ... has (or may have) op_first: */
2262 || family == OA_UNOP
2263 || family == OA_LOGOP
2264 || family == OA_BASEOP_OR_UNOP
2265 || family == OA_FILESTATOP
2266 || family == OA_LOOPEXOP
b46e009d 2267 || family == OA_METHOP
20220689
DM
2268 /* I don't know why SASSIGN is tagged as OA_BASEOP - DAPM */
2269 || type == OP_SASSIGN
2270 || type == OP_CUSTOM
2271 || type == OP_NULL /* new_logop does this */
2272 );
2273 /* XXX list form of 'x' is has a null op_last. This is wrong,
2274 * but requires too much hacking (e.g. in Deparse) to fix for
2275 * now */
2276 if (type == OP_REPEAT && (o->op_private & OPpREPEAT_DOLIST)) {
2277 assert(has_last);
2278 has_last = 0;
2279 }
2280
2281 for (kid = cUNOPo->op_first; kid; kid = OP_SIBLING(kid)) {
29e61fd9 2282# ifdef PERL_OP_PARENT
20220689
DM
2283 if (!OP_HAS_SIBLING(kid)) {
2284 if (has_last)
29e61fd9 2285 assert(kid == cLISTOPo->op_last);
20220689
DM
2286 assert(kid->op_sibling == o);
2287 }
29e61fd9 2288# else
20220689
DM
2289 if (OP_HAS_SIBLING(kid)) {
2290 assert(!kid->op_lastsib);
2291 }
2292 else {
2293 assert(kid->op_lastsib);
2294 if (has_last)
29e61fd9 2295 assert(kid == cLISTOPo->op_last);
c4b20975 2296 }
20220689 2297# endif
c4b20975
DM
2298 }
2299#endif
2300
1ed44841 2301 for (kid = cUNOPo->op_first; kid; kid = OP_SIBLING(kid))
d164302a
GG
2302 finalize_op(kid);
2303 }
2304}
2305
2306/*
3ad73efd
Z
2307=for apidoc Amx|OP *|op_lvalue|OP *o|I32 type
2308
2309Propagate lvalue ("modifiable") context to an op and its children.
2310I<type> represents the context type, roughly based on the type of op that
2311would do the modifying, although C<local()> is represented by OP_NULL,
2312because it has no op type of its own (it is signalled by a flag on
001c3c51
FC
2313the lvalue op).
2314
2315This function detects things that can't be modified, such as C<$x+1>, and
72d33970 2316generates errors for them. For example, C<$x+1 = 2> would cause it to be
001c3c51
FC
2317called with an op of type OP_ADD and a C<type> argument of OP_SASSIGN.
2318
2319It also flags things that need to behave specially in an lvalue context,
2320such as C<$$x = 5> which might have to vivify a reference in C<$x>.
3ad73efd
Z
2321
2322=cut
2323*/
ddeae0f1 2324
375879aa
FC
2325static bool
2326S_vivifies(const OPCODE type)
2327{
2328 switch(type) {
2329 case OP_RV2AV: case OP_ASLICE:
2330 case OP_RV2HV: case OP_KVASLICE:
2331 case OP_RV2SV: case OP_HSLICE:
2332 case OP_AELEMFAST: case OP_KVHSLICE:
2333 case OP_HELEM:
2334 case OP_AELEM:
2335 return 1;
2336 }
2337 return 0;
2338}
2339
7664512e 2340static void
63702de8 2341S_lvref(pTHX_ OP *o, I32 type)
7664512e 2342{
727d2dc6 2343 dVAR;
7664512e
FC
2344 OP *kid;
2345 switch (o->op_type) {
2346 case OP_COND_EXPR:
2347 for (kid = OP_SIBLING(cUNOPo->op_first); kid;
2348 kid = OP_SIBLING(kid))
63702de8 2349 S_lvref(aTHX_ kid, type);
7664512e
FC
2350 /* FALLTHROUGH */
2351 case OP_PUSHMARK:
2352 return;
2353 case OP_RV2AV:
2354 if (cUNOPo->op_first->op_type != OP_GV) goto badref;
2355 o->op_flags |= OPf_STACKED;
2356 if (o->op_flags & OPf_PARENS) {
2357 if (o->op_private & OPpLVAL_INTRO) {
7664512e
FC
2358 yyerror(Perl_form(aTHX_ "Can't modify reference to "
2359 "localized parenthesized array in list assignment"));
2360 return;
2361 }
2362 slurpy:
2363 o->op_type = OP_LVAVREF;
2364 o->op_ppaddr = PL_ppaddr[OP_LVAVREF];
2365 o->op_private &= OPpLVAL_INTRO|OPpPAD_STATE;
2366 o->op_flags |= OPf_MOD|OPf_REF;
2367 return;
2368 }
2369 o->op_private |= OPpLVREF_AV;
2370 goto checkgv;
408e9044 2371 case OP_RV2CV:
19abb1ea
FC
2372 kid = cUNOPo->op_first;
2373 if (kid->op_type == OP_NULL)
2374 kid = cUNOPx(kUNOP->op_first->op_sibling)
408e9044
FC
2375 ->op_first;
2376 o->op_private = OPpLVREF_CV;
2377 if (kid->op_type == OP_GV)
2378 o->op_flags |= OPf_STACKED;
2379 else if (kid->op_type == OP_PADCV) {
2380 o->op_targ = kid->op_targ;
2381 kid->op_targ = 0;
2382 op_free(cUNOPo->op_first);
2383 cUNOPo->op_first = NULL;
2384 o->op_flags &=~ OPf_KIDS;
2385 }
2386 else goto badref;
2387 break;
7664512e
FC
2388 case OP_RV2HV:
2389 if (o->op_flags & OPf_PARENS) {
2390 parenhash:
7664512e
FC
2391 yyerror(Perl_form(aTHX_ "Can't modify reference to "
2392 "parenthesized hash in list assignment"));
2393 return;
2394 }
2395 o->op_private |= OPpLVREF_HV;
2396 /* FALLTHROUGH */
2397 case OP_RV2SV:
2398 checkgv:
2399 if (cUNOPo->op_first->op_type != OP_GV) goto badref;
2400 o->op_flags |= OPf_STACKED;
6f5dab3c
FC
2401 break;
2402 case OP_PADHV:
2403 if (o->op_flags & OPf_PARENS) goto parenhash;
2404 o->op_private |= OPpLVREF_HV;
7664512e
FC
2405 /* FALLTHROUGH */
2406 case OP_PADSV:
6f5dab3c 2407 PAD_COMPNAME_GEN_set(o->op_targ, PERL_INT_MAX);
7664512e
FC
2408 break;
2409 case OP_PADAV:
6f5dab3c 2410 PAD_COMPNAME_GEN_set(o->op_targ, PERL_INT_MAX);
7664512e
FC
2411 if (o->op_flags & OPf_PARENS) goto slurpy;
2412 o->op_private |= OPpLVREF_AV;
2413 break;
7664512e
FC
2414 case OP_AELEM:
2415 case OP_HELEM:
2416 o->op_private |= OPpLVREF_ELEM;
2417 o->op_flags |= OPf_STACKED;
2418 break;
2419 case OP_ASLICE:
2420 case OP_HSLICE:
2421 o->op_type = OP_LVREFSLICE;
2422 o->op_ppaddr = PL_ppaddr[OP_LVREFSLICE];
2423 o->op_private &= OPpLVAL_INTRO|OPpLVREF_ELEM;
2424 return;
2425 case OP_NULL:
2426 if (o->op_flags & OPf_SPECIAL) /* do BLOCK */
2427 goto badref;
2428 else if (!(o->op_flags & OPf_KIDS))
2429 return;
2430 if (o->op_targ != OP_LIST) {
63702de8 2431 S_lvref(aTHX_ cBINOPo->op_first, type);
7664512e
FC
2432 return;
2433 }
2434 /* FALLTHROUGH */
2435 case OP_LIST:
2436 for (kid = cLISTOPo->op_first; kid; kid = OP_SIBLING(kid)) {
2437 assert((kid->op_flags & OPf_WANT) != OPf_WANT_VOID);
63702de8 2438 S_lvref(aTHX_ kid, type);
7664512e
FC
2439 }
2440 return;
2441 case OP_STUB:
2442 if (o->op_flags & OPf_PARENS)
2443 return;
2444 /* FALLTHROUGH */
2445 default:
2446 badref:
cf6e1fa1 2447 /* diag_listed_as: Can't modify reference to %s in %s assignment */
63702de8 2448 yyerror(Perl_form(aTHX_ "Can't modify reference to %s in %s",
7664512e
FC
2449 o->op_type == OP_NULL && o->op_flags & OPf_SPECIAL
2450 ? "do block"
63702de8
FC
2451 : OP_DESC(o),
2452 PL_op_desc[type]));
7664512e
FC
2453 return;
2454 }
2455 o->op_type = OP_LVREF;
2456 o->op_ppaddr = PL_ppaddr[OP_LVREF];
3ad7d304
FC
2457 o->op_private &=
2458 OPpLVAL_INTRO|OPpLVREF_ELEM|OPpLVREF_TYPE|OPpPAD_STATE;
d39c26a6
FC
2459 if (type == OP_ENTERLOOP)
2460 o->op_private |= OPpLVREF_ITER;
7664512e
FC
2461}
2462
79072805 2463OP *
d3d7d28f 2464Perl_op_lvalue_flags(pTHX_ OP *o, I32 type, U32 flags)
79072805 2465{
27da23d5 2466 dVAR;
79072805 2467 OP *kid;
ddeae0f1
DM
2468 /* -1 = error on localize, 0 = ignore localize, 1 = ok to localize */
2469 int localize = -1;
79072805 2470
13765c85 2471 if (!o || (PL_parser && PL_parser->error_count))
11343788 2472 return o;
79072805 2473
b162f9ea 2474 if ((o->op_private & OPpTARGET_MY)
7e363e51
GS
2475 && (PL_opargs[o->op_type] & OA_TARGLEX))/* OPp share the meaning */
2476 {
b162f9ea 2477 return o;
7e363e51 2478 }
1c846c1f 2479
5c906035
GG
2480 assert( (o->op_flags & OPf_WANT) != OPf_WANT_VOID );
2481
69974ce6
FC
2482 if (type == OP_PRTF || type == OP_SPRINTF) type = OP_ENTERSUB;
2483
11343788 2484 switch (o->op_type) {
68dc0745 2485 case OP_UNDEF:
3280af22 2486 PL_modcount++;
5dc0d613 2487 return o;
5f05dabc 2488 case OP_STUB:
b5bbe64a 2489 if ((o->op_flags & OPf_PARENS))
5f05dabc
PP
2490 break;
2491 goto nomod;
a0d0e21e 2492 case OP_ENTERSUB:
f79aa60b 2493 if ((type == OP_UNDEF || type == OP_REFGEN || type == OP_LOCK) &&
11343788
MB
2494 !(o->op_flags & OPf_STACKED)) {
2495 o->op_type = OP_RV2CV; /* entersub => rv2cv */
22c35a8c 2496 o->op_ppaddr = PL_ppaddr[OP_RV2CV];
11343788 2497 assert(cUNOPo->op_first->op_type == OP_NULL);
93c66552 2498 op_null(((LISTOP*)cUNOPo->op_first)->op_first);/* disable pushmark */
79072805
LW
2499 break;
2500 }
cd06dffe 2501 else { /* lvalue subroutine call */
9411a3c7 2502 o->op_private |= OPpLVAL_INTRO;
e6438c1a 2503 PL_modcount = RETURN_UNLIMITED_NUMBER;
9411a3c7
FC
2504 if (type == OP_GREPSTART || type == OP_ENTERSUB
2505 || type == OP_REFGEN || type == OP_LEAVESUBLV) {
d0887bf3 2506 /* Potential lvalue context: */
cd06dffe
GS
2507 o->op_private |= OPpENTERSUB_INARGS;
2508 break;
2509 }
2510 else { /* Compile-time error message: */
2511 OP *kid = cUNOPo->op_first;
2512 CV *cv;
2eaf799e 2513 GV *gv;
cd06dffe 2514
3ea285d1
AL
2515 if (kid->op_type != OP_PUSHMARK) {
2516 if (kid->op_type != OP_NULL || kid->op_targ != OP_LIST)
2517 Perl_croak(aTHX_
2518 "panic: unexpected lvalue entersub "
2519 "args: type/targ %ld:%"UVuf,
2520 (long)kid->op_type, (UV)kid->op_targ);
2521 kid = kLISTOP->op_first;
2522 }
1ed44841
DM
2523 while (OP_HAS_SIBLING(kid))
2524 kid = OP_SIBLING(kid);
cd06dffe 2525 if (!(kid->op_type == OP_NULL && kid->op_targ == OP_RV2CV)) {
cd06dffe
GS
2526 break; /* Postpone until runtime */
2527 }
b2ffa427 2528
cd06dffe
GS
2529 kid = kUNOP->op_first;
2530 if (kid->op_type == OP_NULL && kid->op_targ == OP_RV2SV)
2531 kid = kUNOP->op_first;
b2ffa427 2532 if (kid->op_type == OP_NULL)
cd06dffe
GS
2533 Perl_croak(aTHX_
2534 "Unexpected constant lvalue entersub "
55140b79 2535 "entry via type/targ %ld:%"UVuf,
3d811634 2536 (long)kid->op_type, (UV)kid->op_targ);
cd06dffe 2537 if (kid->op_type != OP_GV) {
cd06dffe
GS
2538 break;
2539 }
b2ffa427 2540
2eaf799e
FC
2541 gv = kGVOP_gv;
2542 cv = isGV(gv)
2543 ? GvCV(gv)
2544 : SvROK(gv) && SvTYPE(SvRV(gv)) == SVt_PVCV
2545 ? MUTABLE_CV(SvRV(gv))
2546 : NULL;
1c846c1f 2547 if (!cv)
da1dff94 2548 break;
cd06dffe
GS
2549 if (CvLVALUE(cv))
2550 break;
2551 }
2552 }
924ba076 2553 /* FALLTHROUGH */
79072805 2554 default:
a0d0e21e 2555 nomod:
f5d552b4 2556 if (flags & OP_LVALUE_NO_CROAK) return NULL;
6fbb66d6 2557 /* grep, foreach, subcalls, refgen */
145b2bbb
FC
2558 if (type == OP_GREPSTART || type == OP_ENTERSUB
2559 || type == OP_REFGEN || type == OP_LEAVESUBLV)
a0d0e21e 2560 break;
cea2e8a9 2561 yyerror(Perl_form(aTHX_ "Can't modify %s in %s",
638bc118 2562 (o->op_type == OP_NULL && (o->op_flags & OPf_SPECIAL)
cd06dffe
GS
2563 ? "do block"
2564 : (o->op_type == OP_ENTERSUB
2565 ? "non-lvalue subroutine call"
53e06cf0 2566 : OP_DESC(o))),
22c35a8c 2567 type ? PL_op_desc[type] : "local"));
11343788 2568 return o;
79072805 2569
a0d0e21e
LW
2570 case OP_PREINC:
2571 case OP_PREDEC:
2572 case OP_POW:
2573 case OP_MULTIPLY:
2574 case OP_DIVIDE:
2575 case OP_MODULO:
2576 case OP_REPEAT:
2577 case OP_ADD:
2578 case OP_SUBTRACT:
2579 case OP_CONCAT:
2580 case OP_LEFT_SHIFT:
2581 case OP_RIGHT_SHIFT:
2582 case OP_BIT_AND:
2583 case OP_BIT_XOR:
2584 case OP_BIT_OR:
2585 case OP_I_MULTIPLY:
2586 case OP_I_DIVIDE:
2587 case OP_I_MODULO:
2588 case OP_I_ADD:
2589 case OP_I_SUBTRACT:
11343788 2590 if (!(o->op_flags & OPf_STACKED))
a0d0e21e 2591 goto nomod;
3280af22 2592 PL_modcount++;
a0d0e21e 2593 break;
b2ffa427 2594
79072805 2595 case OP_COND_EXPR:
ddeae0f1 2596 localize = 1;
1ed44841 2597 for (kid = OP_SIBLING(cUNOPo->op_first); kid; kid = OP_SIBLING(kid))
3ad73efd 2598 op_lvalue(kid, type);
79072805
LW
2599 break;
2600
2601 case OP_RV2AV:
2602 case OP_RV2HV:
11343788 2603 if (type == OP_REFGEN && o->op_flags & OPf_PARENS) {
e6438c1a 2604 PL_modcount = RETURN_UNLIMITED_NUMBER;
11343788 2605 return o; /* Treat \(@foo) like ordinary list. */
748a9306 2606 }
924ba076 2607 /* FALLTHROUGH */
79072805 2608 case OP_RV2GV:
5dc0d613 2609 if (scalar_mod_type(o, type))
3fe9a6f1 2610 goto nomod;
11343788 2611 ref(cUNOPo->op_first, o->op_type);
924ba076 2612 /* FALLTHROUGH */
79072805
LW
2613 case OP_ASLICE:
2614 case OP_HSLICE:
ddeae0f1 2615 localize = 1;
924ba076 2616 /* FALLTHROUGH */
78f9721b 2617 case OP_AASSIGN:
32cbae3f
FC
2618 /* Do not apply the lvsub flag for rv2[ah]v in scalar context. */
2619 if (type == OP_LEAVESUBLV && (
2620 (o->op_type != OP_RV2AV && o->op_type != OP_RV2HV)
2621 || (o->op_flags & OPf_WANT) != OPf_WANT_SCALAR
2622 ))
631dbaa2 2623 o->op_private |= OPpMAYBE_LVSUB;
924ba076 2624 /* FALLTHROUGH */
93a17b20
LW
2625 case OP_NEXTSTATE:
2626 case OP_DBSTATE:
e6438c1a 2627 PL_modcount = RETURN_UNLIMITED_NUMBER;
79072805 2628 break;
5cae3edb 2629 case OP_KVHSLICE:
6dd3e0f2 2630 case OP_KVASLICE:
5cae3edb
RZ
2631 if (type == OP_LEAVESUBLV)
2632 o->op_private |= OPpMAYBE_LVSUB;
2633 goto nomod;
28c5b5bc
RGS
2634 case OP_AV2ARYLEN:
2635 PL_hints |= HINT_BLOCK_SCOPE;
2636 if (type == OP_LEAVESUBLV)
2637 o->op_private |= OPpMAYBE_LVSUB;
2638 PL_modcount++;
2639 break;
463ee0b2 2640 case OP_RV2SV:
aeea060c 2641 ref(cUNOPo->op_first, o->op_type);
ddeae0f1 2642 localize = 1;
924ba076 2643 /* FALLTHROUGH */
79072805 2644 case OP_GV:
3280af22 2645 PL_hints |= HINT_BLOCK_SCOPE;
924ba076 2646 /* FALLTHROUGH */
463ee0b2 2647 case OP_SASSIGN:
bf4b1e52
GS
2648 case OP_ANDASSIGN:
2649 case OP_ORASSIGN:
c963b151 2650 case OP_DORASSIGN:
ddeae0f1
DM
2651 PL_modcount++;
2652 break;
2653
8990e307 2654 case OP_AELEMFAST:
93bad3fd 2655 case OP_AELEMFAST_LEX:
6a077020 2656 localize = -1;
3280af22 2657 PL_modcount++;
8990e307
LW
2658 break;
2659
748a9306
LW
2660 case OP_PADAV:
2661 case OP_PADHV:
e6438c1a 2662 PL_modcount = RETURN_UNLIMITED_NUMBER;
5196be3e
MB
2663 if (type == OP_REFGEN && o->op_flags & OPf_PARENS)
2664 return o; /* Treat \(@foo) like ordinary list. */
2665 if (scalar_mod_type(o, type))
3fe9a6f1 2666 goto nomod;
32cbae3f
FC
2667 if ((o->op_flags & OPf_WANT) != OPf_WANT_SCALAR
2668 && type == OP_LEAVESUBLV)
78f9721b 2669 o->op_private |= OPpMAYBE_LVSUB;
924ba076 2670 /* FALLTHROUGH */
748a9306 2671 case OP_PADSV:
3280af22 2672 PL_modcount++;
ddeae0f1 2673 if (!type) /* local() */
5ede95a0
BF
2674 Perl_croak(aTHX_ "Can't localize lexical variable %"SVf,
2675 PAD_COMPNAME_SV(o->op_targ));
463ee0b2
LW
2676 break;
2677
748a9306 2678 case OP_PUSHMARK:
ddeae0f1 2679 localize = 0;
748a9306 2680 break;
b2ffa427 2681
69969c6f 2682 case OP_KEYS:
d8065907 2683 case OP_RKEYS:
fad4a2e4 2684 if (type != OP_SASSIGN && type != OP_LEAVESUBLV)
69969c6f 2685 goto nomod;
5d82c453
GA
2686 goto lvalue_func;
2687 case OP_SUBSTR:
2688 if (o->op_private == 4) /* don't allow 4 arg substr as lvalue */
2689 goto nomod;
924ba076 2690 /* FALLTHROUGH */
a0d0e21e 2691 case OP_POS:
463ee0b2 2692 case OP_VEC:
fad4a2e4 2693 lvalue_func:
78f9721b
SM
2694 if (type == OP_LEAVESUBLV)
2695 o->op_private |= OPpMAYBE_LVSUB;
11343788 2696 if (o->op_flags & OPf_KIDS)
1ed44841 2697 op_lvalue(OP_SIBLING(cBINOPo->op_first), type);
463ee0b2 2698 break;
a0d0e21e 2699
463ee0b2
LW
2700 case OP_AELEM:
2701 case OP_HELEM:
11343788 2702 ref(cBINOPo->op_first, o->op_type);
68dc0745 2703 if (type == OP_ENTERSUB &&
5dc0d613
MB
2704 !(o->op_private & (OPpLVAL_INTRO | OPpDEREF)))
2705 o->op_private |= OPpLVAL_DEFER;
78f9721b
SM
2706 if (type == OP_LEAVESUBLV)
2707 o->op_private |= OPpMAYBE_LVSUB;
ddeae0f1 2708 localize = 1;
3280af22 2709 PL_modcount++;
463ee0b2
LW
2710 break;
2711
463ee0b2 2712 case OP_LEAVE:
a373464f 2713 case OP_LEAVELOOP:
2ec7f6f2 2714 o->op_private |= OPpLVALUE;
924ba076 2715 /* FALLTHROUGH */
2ec7f6f2 2716 case OP_SCOPE:
463ee0b2 2717 case OP_ENTER:
78f9721b 2718 case OP_LINESEQ:
ddeae0f1 2719 localize = 0;
11343788 2720 if (o->op_flags & OPf_KIDS)
3ad73efd 2721 op_lvalue(cLISTOPo->op_last, type);
a0d0e21e
LW
2722 break;
2723
2724 case OP_NULL:
ddeae0f1 2725 localize = 0;
638bc118
GS
2726 if (o->op_flags & OPf_SPECIAL) /* do BLOCK */
2727 goto nomod;
2728 else if (!(o->op_flags & OPf_KIDS))
463ee0b2 2729 break;
11343788 2730 if (o->op_targ != OP_LIST) {
3ad73efd 2731 op_lvalue(cBINOPo->op_first, type);
a0d0e21e
LW
2732 break;
2733 }
924ba076 2734 /* FALLTHROUGH */
463ee0b2 2735 case OP_LIST:
ddeae0f1 2736 localize = 0;
1ed44841 2737 for (kid = cLISTOPo->op_first; kid; kid = OP_SIBLING(kid))
5c906035
GG
2738 /* elements might be in void context because the list is
2739 in scalar context or because they are attribute sub calls */
2740 if ( (kid->op_flags & OPf_WANT) != OPf_WANT_VOID )
2741 op_lvalue(kid, type);
463ee0b2 2742 break;
78f9721b 2743
1efec5ed
FC
2744 case OP_COREARGS:
2745 return o;
2ec7f6f2
FC
2746
2747 case OP_AND:
2748 case OP_OR:
375879aa
FC
2749 if (type == OP_LEAVESUBLV
2750 || !S_vivifies(cLOGOPo->op_first->op_type))
2751 op_lvalue(cLOGOPo->op_first, type);
2752 if (type == OP_LEAVESUBLV
1ed44841
DM
2753 || !S_vivifies(OP_SIBLING(cLOGOPo->op_first)->op_type))
2754 op_lvalue(OP_SIBLING(cLOGOPo->op_first), type);
2ec7f6f2 2755 goto nomod;
26a50d99
FC
2756
2757 case OP_SREFGEN:
d39c26a6
FC
2758 if (type != OP_AASSIGN && type != OP_SASSIGN
2759 && type != OP_ENTERLOOP)
2760 goto nomod;
7664512e 2761 /* Don’t bother applying lvalue context to the ex-list. */
26a50d99 2762 kid = cUNOPx(cUNOPo->op_first)->op_first;
217e3565
FC
2763 assert (!OP_HAS_SIBLING(kid));
2764 goto kid_2lvref;
2765 case OP_REFGEN:
2766 if (type != OP_AASSIGN) goto nomod;
7664512e
FC
2767 kid = cUNOPo->op_first;
2768 kid_2lvref:
2769 {
2770 const U8 ec = PL_parser ? PL_parser->error_count : 0;
63702de8 2771 S_lvref(aTHX_ kid, type);
7664512e 2772 if (!PL_parser || PL_parser->error_count == ec) {
baabe3fb 2773 if (!FEATURE_REFALIASING_IS_ENABLED)
7664512e 2774 Perl_croak(aTHX_
baabe3fb 2775 "Experimental aliasing via reference not enabled");
7664512e 2776 Perl_ck_warner_d(aTHX_
baabe3fb
FC
2777 packWARN(WARN_EXPERIMENTAL__REFALIASING),
2778 "Aliasing via reference is experimental");
7664512e
FC
2779 }
2780 }
217e3565
FC
2781 if (o->op_type == OP_REFGEN)
2782 op_null(cUNOPx(cUNOPo->op_first)->op_first); /* pushmark */
2783 op_null(o);
26a50d99 2784 return o;
463ee0b2 2785 }
58d95175 2786
8be1be90
AMS
2787 /* [20011101.069] File test operators interpret OPf_REF to mean that
2788 their argument is a filehandle; thus \stat(".") should not set
2789 it. AMS 20011102 */
2790 if (type == OP_REFGEN &&
ef69c8fc 2791 PL_check[o->op_type] == Perl_ck_ftst)
8be1be90
AMS
2792 return o;
2793
2794 if (type != OP_LEAVESUBLV)
2795 o->op_flags |= OPf_MOD;
2796
2797 if (type == OP_AASSIGN || type == OP_SASSIGN)
2798 o->op_flags |= OPf_SPECIAL|OPf_REF;
ddeae0f1
DM
2799 else if (!type) { /* local() */
2800 switch (localize) {
2801 case 1:
2802 o->op_private |= OPpLVAL_INTRO;
2803 o->op_flags &= ~OPf_SPECIAL;
2804 PL_hints |= HINT_BLOCK_SCOPE;
2805 break;
2806 case 0:
2807 break;
2808 case -1:
a2a5de95
NC
2809 Perl_ck_warner(aTHX_ packWARN(WARN_SYNTAX),
2810 "Useless localization of %s", OP_DESC(o));
ddeae0f1 2811 }
463ee0b2 2812 }
8be1be90
AMS
2813 else if (type != OP_GREPSTART && type != OP_ENTERSUB
2814 && type != OP_LEAVESUBLV)
2815 o->op_flags |= OPf_REF;
11343788 2816 return o;
463ee0b2
LW
2817}
2818
864dbfa3 2819STATIC bool
5f66b61c 2820S_scalar_mod_type(const OP *o, I32 type)
3fe9a6f1
PP
2821{
2822 switch (type) {
32a60974 2823 case OP_POS:
3fe9a6f1 2824 case OP_SASSIGN:
1efec5ed 2825 if (o && o->op_type == OP_RV2GV)
3fe9a6f1 2826 return FALSE;
924ba076 2827 /* FALLTHROUGH */
3fe9a6f1
PP
2828 case OP_PREINC:
2829 case OP_PREDEC:
2830 case OP_POSTINC:
2831 case OP_POSTDEC:
2832 case OP_I_PREINC:
2833 case OP_I_PREDEC:
2834 case OP_I_POSTINC:
2835 case OP_I_POSTDEC:
2836 case OP_POW:
2837 case OP_MULTIPLY:
2838 case OP_DIVIDE:
2839 case OP_MODULO:
2840 case OP_REPEAT:
2841 case OP_ADD:
2842 case OP_SUBTRACT:
2843 case OP_I_MULTIPLY:
2844 case OP_I_DIVIDE:
2845 case OP_I_MODULO:
2846 case OP_I_ADD:
2847 case OP_I_SUBTRACT:
2848 case OP_LEFT_SHIFT:
2849 case OP_RIGHT_SHIFT:
2850 case OP_BIT_AND:
2851 case OP_BIT_XOR:
2852 case OP_BIT_OR:
2853 case OP_CONCAT:
2854 case OP_SUBST:
2855 case OP_TRANS:
bb16bae8 2856 case OP_TRANSR:
49e9fbe6
GS
2857 case OP_READ:
2858 case OP_SYSREAD:
2859 case OP_RECV:
bf4b1e52
GS
2860 case OP_ANDASSIGN:
2861 case OP_ORASSIGN:
410d09fe 2862 case OP_DORASSIGN:
3fe9a6f1
PP
2863 return TRUE;
2864 default:
2865 return FALSE;
2866 }
2867}
2868
35cd451c 2869STATIC bool
5f66b61c 2870S_is_handle_constructor(const OP *o, I32 numargs)
35cd451c 2871{
7918f24d
NC
2872 PERL_ARGS_ASSERT_IS_HANDLE_CONSTRUCTOR;
2873
35cd451c
GS
2874 switch (o->op_type) {
2875 case OP_PIPE_OP:
2876 case OP_SOCKPAIR:
504618e9 2877 if (numargs == 2)
35cd451c 2878 return TRUE;
924ba076 2879 /* FALLTHROUGH */
35cd451c
GS
2880 case OP_SYSOPEN:
2881 case OP_OPEN:
ded8aa31 2882 case OP_SELECT: /* XXX c.f. SelectSaver.pm */
35cd451c
GS
2883 case OP_SOCKET:
2884 case OP_OPEN_DIR:
2885 case OP_ACCEPT:
504618e9 2886 if (numargs == 1)
35cd451c 2887 return TRUE;
5f66b61c 2888 /* FALLTHROUGH */
35cd451c
GS
2889 default:
2890 return FALSE;
2891 }
2892}
2893
0d86688d
NC
2894static OP *
2895S_refkids(pTHX_ OP *o, I32 type)
463ee0b2 2896{
11343788 2897 if (o && o->op_flags & OPf_KIDS) {
6867be6d 2898 OP *kid;
1ed44841 2899 for (kid = cLISTOPo->op_first; kid; kid = OP_SIBLING(kid))
463ee0b2
LW
2900 ref(kid, type);
2901 }
11343788 2902 return o;
463ee0b2
LW
2903}
2904
2905OP *
e4c5ccf3 2906Perl_doref(pTHX_ OP *o, I32 type, bool set_op_ref)
463ee0b2 2907{
27da23d5 2908 dVAR;
463ee0b2 2909 OP *kid;
463ee0b2 2910
7918f24d
NC
2911 PERL_ARGS_ASSERT_DOREF;
2912
13765c85 2913 if (!o || (PL_parser && PL_parser->error_count))
11343788 2914 return o;
463ee0b2 2915
11343788 2916 switch (o->op_type) {
a0d0e21e 2917 case OP_ENTERSUB:
f4df43b5 2918 if ((type == OP_EXISTS || type == OP_DEFINED) &&
11343788
MB
2919 !(o->op_flags & OPf_STACKED)) {
2920 o->op_type = OP_RV2CV; /* entersub => rv2cv */
22c35a8c 2921 o->op_ppaddr = PL_ppaddr[OP_RV2CV];
11343788 2922 assert(cUNOPo->op_first->op_type == OP_NULL);
93c66552 2923 op_null(((LISTOP*)cUNOPo->op_first)->op_first); /* disable pushmark */
11343788 2924 o->op_flags |= OPf_SPECIAL;
8990e307 2925 }
767eda44 2926 else if (type == OP_RV2SV || type == OP_RV2AV || type == OP_RV2HV){
0e9700df
GG
2927 o->op_private |= (type == OP_RV2AV ? OPpDEREF_AV
2928 : type == OP_RV2HV ? OPpDEREF_HV
2929 : OPpDEREF_SV);
767eda44
FC
2930 o->op_flags |= OPf_MOD;
2931 }
2932
8990e307 2933 break;
aeea060c 2934
463ee0b2 2935 case OP_COND_EXPR:
1ed44841 2936 for (kid = OP_SIBLING(cUNOPo->op_first); kid; kid = OP_SIBLING(kid))
e4c5ccf3 2937 doref(kid, type, set_op_ref);
463ee0b2 2938 break;
8990e307 2939 case OP_RV2SV:
35cd451c
GS
2940 if (type == OP_DEFINED)
2941 o->op_flags |= OPf_SPECIAL; /* don't create GV */
e4c5ccf3 2942 doref(cUNOPo->op_first, o->op_type, set_op_ref);
924ba076 2943 /* FALLTHROUGH */
4633a7c4 2944 case OP_PADSV:
5f05dabc 2945 if (type == OP_RV2SV || type == OP_RV2AV || type == OP_RV2HV) {
5dc0d613
MB
2946 o->op_private |= (type == OP_RV2AV ? OPpDEREF_AV
2947 : type == OP_RV2HV ? OPpDEREF_HV
2948 : OPpDEREF_SV);
11343788 2949 o->op_flags |= OPf_MOD;
a0d0e21e 2950 }
8990e307 2951 break;
1c846c1f 2952
463ee0b2
LW
2953 case OP_RV2AV:
2954 case OP_RV2HV:
e4c5ccf3
RH
2955 if (set_op_ref)
2956 o->op_flags |= OPf_REF;
924ba076 2957 /* FALLTHROUGH */
463ee0b2 2958 case OP_RV2GV:
35cd451c
GS
2959 if (type == OP_DEFINED)
2960 o->op_flags |= OPf_SPECIAL; /* don't create GV */
e4c5ccf3 2961 doref(cUNOPo->op_first, o->op_type, set_op_ref);
463ee0b2 2962 break;
8990e307 2963
463ee0b2
LW
2964 case OP_PADAV:
2965 case OP_PADHV:
e4c5ccf3
RH
2966 if (set_op_ref)
2967 o->op_flags |= OPf_REF;
79072805 2968 break;
aeea060c 2969
8990e307 2970 case OP_SCALAR:
79072805 2971 case OP_NULL:
518618af 2972 if (!(o->op_flags & OPf_KIDS) || type == OP_DEFINED)
463ee0b2 2973 break;
e4c5ccf3 2974 doref(cBINOPo->op_first, type, set_op_ref);
79072805
LW
2975 break;
2976 case OP_AELEM:
2977 case OP_HELEM:
e4c5ccf3 2978 doref(cBINOPo->op_first, o->op_type, set_op_ref);
5f05dabc 2979 if (type == OP_RV2SV || type == OP_RV2AV || type == OP_RV2HV) {
5dc0d613
MB
2980 o->op_private |= (type == OP_RV2AV ? OPpDEREF_AV
2981 : type == OP_RV2HV ? OPpDEREF_HV
2982 : OPpDEREF_SV);
11343788 2983 o->op_flags |= OPf_MOD;
8990e307 2984 }
79072805
LW
2985 break;
2986
463ee0b2 2987 case OP_SCOPE:
79072805 2988 case OP_LEAVE:
e4c5ccf3 2989 set_op_ref = FALSE;
924ba076 2990 /* FALLTHROUGH */
79072805 2991 case OP_ENTER:
8990e307 2992 case OP_LIST:
11343788 2993 if (!(o->op_flags & OPf_KIDS))
79072805 2994 break;
e4c5ccf3 2995 doref(cLISTOPo->op_last, type, set_op_ref);
79072805 2996 break;
a0d0e21e
LW
2997 default:
2998 break;
79072805 2999 }
11343788 3000 return scalar(o);
8990e307 3001
79072805
LW
3002}
3003
09bef843
SB
3004STATIC OP *
3005S_dup_attrlist(pTHX_ OP *o)
3006{
0bd48802 3007 OP *rop;
09bef843 3008
7918f24d
NC
3009 PERL_ARGS_ASSERT_DUP_ATTRLIST;
3010
09bef843
SB
3011 /* An attrlist is either a simple OP_CONST or an OP_LIST with kids,
3012 * where the first kid is OP_PUSHMARK and the remaining ones
3013 * are OP_CONST. We need to push the OP_CONST values.
3014 */
3015 if (o->op_type == OP_CONST)
b37c2d43 3016 rop = newSVOP(OP_CONST, o->op_flags, SvREFCNT_inc_NN(cSVOPo->op_sv));
09bef843
SB
3017 else {
3018 assert((o->op_type == OP_LIST) && (o->op_flags & OPf_KIDS));
5f66b61c 3019 rop = NULL;
1ed44841 3020 for (o = cLISTOPo->op_first; o; o = OP_SIBLING(o)) {
09bef843 3021 if (o->op_type == OP_CONST)
2fcb4757 3022 rop = op_append_elem(OP_LIST, rop,
09bef843 3023 newSVOP(OP_CONST, o->op_flags,
b37c2d43 3024 SvREFCNT_inc_NN(cSVOPo->op_sv)));
09bef843
SB
3025 }
3026 }
3027 return rop;
3028}
3029
3030STATIC void
ad0dc73b 3031S_apply_attrs(pTHX_ HV *stash, SV *target, OP *attrs)
09bef843 3032{
ad0dc73b 3033 SV * const stashsv = stash ? newSVhek(HvNAME_HEK(stash)) : &PL_sv_no;
09bef843 3034
7918f24d
NC
3035 PERL_ARGS_ASSERT_APPLY_ATTRS;
3036
09bef843 3037 /* fake up C<use attributes $pkg,$rv,@attrs> */
e4783991 3038
09bef843 3039#define ATTRSMODULE "attributes"
95f0a2f1
SB
3040#define ATTRSMODULE_PM "attributes.pm"
3041
ad0dc73b 3042 Perl_load_module(aTHX_ PERL_LOADMOD_IMPORT_OPS,
6136c704
AL
3043 newSVpvs(ATTRSMODULE),
3044 NULL,
2fcb4757 3045 op_prepend_elem(OP_LIST,
95f0a2f1 3046 newSVOP(OP_CONST, 0, stashsv),
2fcb4757 3047 op_prepend_elem(OP_LIST,
95f0a2f1
SB
3048 newSVOP(OP_CONST, 0,
3049 newRV(target)),
3050 dup_attrlist(attrs))));
09bef843
SB
3051}
3052
95f0a2f1
SB
3053STATIC void
3054S_apply_attrs_my(pTHX_ HV *stash, OP *target, OP *attrs, OP **imopsp)
3055{
3056 OP *pack, *imop, *arg;
ad0dc73b 3057 SV *meth, *stashsv, **svp;
95f0a2f1 3058
7918f24d
NC
3059 PERL_ARGS_ASSERT_APPLY_ATTRS_MY;
3060
95f0a2f1
SB
3061 if (!attrs)
3062 return;
3063
3064 assert(target->op_type == OP_PADSV ||
3065 target->op_type == OP_PADHV ||
3066 target->op_type == OP_PADAV);
3067
3068 /* Ensure that attributes.pm is loaded. */
ad0dc73b
FC
3069 /* Don't force the C<use> if we don't need it. */
3070 svp = hv_fetchs(GvHVn(PL_incgv), ATTRSMODULE_PM, FALSE);
3071 if (svp && *svp != &PL_sv_undef)
3072 NOOP; /* already in %INC */
3073 else
3074 Perl_load_module(aTHX_ PERL_LOADMOD_NOIMPORT,
3075 newSVpvs(ATTRSMODULE), NULL);
95f0a2f1
SB
3076
3077 /* Need package name for method call. */
6136c704 3078 pack = newSVOP(OP_CONST, 0, newSVpvs(ATTRSMODULE));
95f0a2f1
SB
3079
3080 /* Build up the real arg-list. */
5aaec2b4
NC
3081 stashsv = stash ? newSVhek(HvNAME_HEK(stash)) : &PL_sv_no;
3082
95f0a2f1
SB
3083 arg = newOP(OP_PADSV, 0);
3084 arg->op_targ = target->op_targ;
2fcb4757 3085 arg = op_prepend_elem(OP_LIST,
95f0a2f1 3086 newSVOP(OP_CONST, 0, stashsv),
2fcb4757 3087 op_prepend_elem(OP_LIST,
95f0a2f1 3088 newUNOP(OP_REFGEN, 0,
3ad73efd 3089 op_lvalue(arg, OP_REFGEN)),
95f0a2f1
SB
3090 dup_attrlist(attrs)));
3091
3092 /* Fake up a method call to import */
18916d0d 3093 meth = newSVpvs_share("import");
95f0a2f1 3094 imop = convert(OP_ENTERSUB, OPf_STACKED|OPf_SPECIAL|OPf_WANT_VOID,
2fcb4757
Z
3095 op_append_elem(OP_LIST,
3096 op_prepend_elem(OP_LIST, pack, list(arg)),
b46e009d 3097 newMETHOP_named(OP_METHOD_NAMED, 0, meth)));
95f0a2f1
SB
3098
3099 /* Combine the ops. */
2fcb4757 3100 *imopsp = op_append_elem(OP_LIST, *imopsp, imop);
95f0a2f1
SB
3101}
3102
3103/*
3104=notfor apidoc apply_attrs_string
3105
3106Attempts to apply a list of attributes specified by the C<attrstr> and
3107C<len> arguments to the subroutine identified by the C<cv> argument which
3108is expected to be associated with the package identified by the C<stashpv>
3109argument (see L<attributes>). It gets this wrong, though, in that it
3110does not correctly identify the boundaries of the individual attribute
3111specifications within C<attrstr>. This is not really intended for the
3112public API, but has to be listed here for systems such as AIX which
3113need an explicit export list for symbols. (It's called from XS code
3114in support of the C<ATTRS:> keyword from F<xsubpp>.) Patches to fix it
3115to respect attribute syntax properly would be welcome.
3116
3117=cut
3118*/
3119
be3174d2 3120void
6867be6d
AL
3121Perl_apply_attrs_string(pTHX_ const char *stashpv, CV *cv,
3122 const char *attrstr, STRLEN len)
be3174d2 3123{
5f66b61c 3124 OP *attrs = NULL;
be3174d2 3125
7918f24d
NC
3126 PERL_ARGS_ASSERT_APPLY_ATTRS_STRING;
3127
be3174d2
GS
3128 if (!len) {
3129 len = strlen(attrstr);
3130 }
3131
3132 while (len) {
3133 for (; isSPACE(*attrstr) && len; --len, ++attrstr) ;
3134 if (len) {
890ce7af 3135 const char * const sstr = attrstr;
be3174d2 3136 for (; !isSPACE(*attrstr) && len; --len, ++attrstr) ;
2fcb4757 3137 attrs = op_append_elem(OP_LIST, attrs,
be3174d2
GS
3138 newSVOP(OP_CONST, 0,
3139 newSVpvn(sstr, attrstr-sstr)));
3140 }
3141 }
3142
3143 Perl_load_module(aTHX_ PERL_LOADMOD_IMPORT_OPS,
6136c704 3144 newSVpvs(ATTRSMODULE),
2fcb4757 3145 NULL, op_prepend_elem(OP_LIST,
be3174d2 3146 newSVOP(OP_CONST, 0, newSVpv(stashpv,0)),
2fcb4757 3147 op_prepend_elem(OP_LIST,
be3174d2 3148 newSVOP(OP_CONST, 0,
ad64d0ec 3149 newRV(MUTABLE_SV(cv))),
be3174d2
GS
3150 attrs)));
3151}
3152
eedb00fa
PM
3153STATIC void
3154S_move_proto_attr(pTHX_ OP **proto, OP **attrs, const GV * name)
3155{
3156 OP *new_proto = NULL;
3157 STRLEN pvlen;
3158 char *pv;
3159 OP *o;
3160
3161 PERL_ARGS_ASSERT_MOVE_PROTO_ATTR;
3162
3163 if (!*attrs)
3164 return;
3165
3166 o = *attrs;
3167 if (o->op_type == OP_CONST) {
3168 pv = SvPV(cSVOPo_sv, pvlen);
3169 if (pvlen >= 10 && memEQ(pv, "prototype(", 10)) {
3170 SV * const tmpsv = newSVpvn_flags(pv + 10, pvlen - 11, SvUTF8(cSVOPo_sv));
3171 SV ** const tmpo = cSVOPx_svp(o);
3172 SvREFCNT_dec(cSVOPo_sv);
3173 *tmpo = tmpsv;
3174 new_proto = o;
3175 *attrs = NULL;
3176 }
3177 } else if (o->op_type == OP_LIST) {
e78bc664 3178 OP * lasto;
eedb00fa 3179 assert(o->op_flags & OPf_KIDS);
e78bc664
PM
3180 lasto = cLISTOPo->op_first;
3181 assert(lasto->op_type == OP_PUSHMARK);
1ed44841 3182 for (o = OP_SIBLING(lasto); o; o = OP_SIBLING(o)) {
eedb00fa
PM
3183 if (o->op_type == OP_CONST) {
3184 pv = SvPV(cSVOPo_sv, pvlen);
3185 if (pvlen >= 10 && memEQ(pv, "prototype(", 10)) {
3186 SV * const tmpsv = newSVpvn_flags(pv + 10, pvlen - 11, SvUTF8(cSVOPo_sv));
3187 SV ** const tmpo = cSVOPx_svp(o);
3188 SvREFCNT_dec(cSVOPo_sv);
3189 *tmpo = tmpsv;
3190 if (new_proto && ckWARN(WARN_MISC)) {
3191 STRLEN new_len;
3192 const char * newp = SvPV(cSVOPo_sv, new_len);
3193 Perl_warner(aTHX_ packWARN(WARN_MISC),
3194 "Attribute prototype(%"UTF8f") discards earlier prototype attribute in same sub",
3195 UTF8fARG(SvUTF8(cSVOPo_sv), new_len, newp));
3196 op_free(new_proto);
3197 }
3198 else if (new_proto)
3199 op_free(new_proto);
3200 new_proto = o;
3253bf85
DM
3201 /* excise new_proto from the list */
3202 op_sibling_splice(*attrs, lasto, 1, NULL);
3203 o = lasto;
eedb00fa
PM
3204 continue;
3205 }
3206 }
3207 lasto = o;
3208 }
3209 /* If the list is now just the PUSHMARK, scrap the whole thing; otherwise attributes.xs
3210 would get pulled in with no real need */
1ed44841 3211 if (!OP_HAS_SIBLING(cLISTOPx(*attrs)->op_first)) {
eedb00fa
PM
3212 op_free(*attrs);
3213 *attrs = NULL;
3214 }
3215 }
3216
3217 if (new_proto) {
3218 SV *svname;
3219 if (isGV(name)) {
3220 svname = sv_newmortal();
3221 gv_efullname3(svname, name, NULL);
3222 }
3223 else if (SvPOK(name) && *SvPVX((SV *)name) == '&')
3224 svname = newSVpvn_flags(SvPVX((SV *)name)+1, SvCUR(name)-1, SvUTF8(name)|SVs_TEMP);
3225 else
3226 svname = (SV *)name;
3227 if (ckWARN(WARN_ILLEGALPROTO))
3228 (void)validate_proto(svname, cSVOPx_sv(new_proto), TRUE);
3229 if (*proto && ckWARN(WARN_PROTOTYPE)) {
3230 STRLEN old_len, new_len;
3231 const char * oldp = SvPV(cSVOPx_sv(*proto), old_len);
3232 const char * newp = SvPV(cSVOPx_sv(new_proto), new_len);
3233
3234 Perl_warner(aTHX_ packWARN(WARN_PROTOTYPE),
3235 "Prototype '%"UTF8f"' overridden by attribute 'prototype(%"UTF8f")'"
3236 " in %"SVf,
3237 UTF8fARG(SvUTF8(cSVOPx_sv(*proto)), old_len, oldp),
3238 UTF8fARG(SvUTF8(cSVOPx_sv(new_proto)), new_len, newp),
3239 SVfARG(svname));
3240 }
3241 if (*proto)
3242 op_free(*proto);
3243 *proto = new_proto;
3244 }
3245}
3246
92bd82a0
FC
3247static void
3248S_cant_declare(pTHX_ OP *o)
3249{
4748e002
FC
3250 if (o->op_type == OP_NULL
3251 && (o->op_flags & (OPf_SPECIAL|OPf_KIDS)) == OPf_KIDS)
3252 o = cUNOPo->op_first;
92bd82a0 3253 yyerror(Perl_form(aTHX_ "Can't declare %s in \"%s\"",
4748e002
FC
3254 o->op_type == OP_NULL
3255 && o->op_flags & OPf_SPECIAL
3256 ? "do block"
3257 : OP_DESC(o),
92bd82a0
FC
3258 PL_parser->in_my == KEY_our ? "our" :
3259 PL_parser->in_my == KEY_state ? "state" :
3260 "my"));
3261}
3262
09bef843 3263STATIC OP *
95f0a2f1 3264S_my_kid(pTHX_ OP *o, OP *attrs, OP **imopsp)
93a17b20 3265{
93a17b20 3266 I32 type;
a1fba7eb 3267 const bool stately = PL_parser && PL_parser->in_my == KEY_state;
93a17b20 3268
7918f24d
NC
3269 PERL_ARGS_ASSERT_MY_KID;
3270
13765c85 3271 if (!o || (PL_parser && PL_parser->error_count))
11343788 3272 return o;
93a17b20 3273
bc61e325 3274 type = o->op_type;
eb8433b7 3275
93a17b20 3276 if (type == OP_LIST) {
6867be6d 3277 OP *kid;
1ed44841 3278 for (kid = cLISTOPo->op_first; kid; kid = OP_SIBLING(kid))
95f0a2f1 3279 my_kid(kid, attrs, imopsp);
0865059d 3280 return o;
8b8c1fb9 3281 } else if (type == OP_UNDEF || type == OP_STUB) {
7766148a 3282 return o;
77ca0c92
LW
3283 } else if (type == OP_RV2SV || /* "our" declaration */
3284 type == OP_RV2AV ||
3285 type == OP_RV2HV) { /* XXX does this let anything illegal in? */
1ce0b88c 3286 if (cUNOPo->op_first->op_type != OP_GV) { /* MJD 20011224 */
92bd82a0 3287 S_cant_declare(aTHX_ o);
1ce0b88c 3288 } else if (attrs) {
551405c4 3289 GV * const gv = cGVOPx_gv(cUNOPo->op_first);
316ebaf2 3290 assert(PL_parser);
12bd6ede
DM
3291 PL_parser->in_my = FALSE;
3292 PL_parser->in_my_stash = NULL;
1ce0b88c
RGS
3293 apply_attrs(GvSTASH(gv),
3294 (type == OP_RV2SV ? GvSV(gv) :
ad64d0ec
NC
3295 type == OP_RV2AV ? MUTABLE_SV(GvAV(gv)) :
3296 type == OP_RV2HV ? MUTABLE_SV(GvHV(gv)) : MUTABLE_SV(gv)),
ad0dc73b 3297 attrs);
1ce0b88c 3298 }
192587c2 3299 o->op_private |= OPpOUR_INTRO;
77ca0c92 3300 return o;
95f0a2f1
SB
3301 }
3302 else if (type != OP_PADSV &&
93a17b20
LW
3303 type != OP_PADAV &&
3304 type != OP_PADHV &&
3305 type != OP_PUSHMARK)
3306 {
92bd82a0 3307 S_cant_declare(aTHX_ o);
11343788 3308 return o;
93a17b20 3309 }
09bef843
SB
3310 else if (attrs && type != OP_PUSHMARK) {
3311 HV *stash;
09bef843 3312
316ebaf2 3313 assert(PL_parser);
12bd6ede
DM
3314 PL_parser->in_my = FALSE;
3315 PL_parser->in_my_stash = NULL;
eb64745e 3316
09bef843 3317 /* check for C<my Dog $spot> when deciding package */
dd2155a4
DM
3318 stash = PAD_COMPNAME_TYPE(o->op_targ);
3319 if (!stash)
09bef843 3320 stash = PL_curstash;
95f0a2f1 3321 apply_attrs_my(stash, o, attrs, imopsp);
09bef843 3322 }
11343788
MB
3323 o->op_flags |= OPf_MOD;
3324 o->op_private |= OPpLVAL_INTRO;
a1fba7eb 3325 if (stately)
952306ac 3326 o->op_private |= OPpPAD_STATE;
11343788 3327 return o;
93a17b20
LW
3328}
3329
3330OP *
09bef843
SB
3331Perl_my_attrs(pTHX_ OP *o, OP *attrs)
3332{
0bd48802 3333 OP *rops;
95f0a2f1
SB
3334 int maybe_scalar = 0;
3335
7918f24d
NC
3336 PERL_ARGS_ASSERT_MY_ATTRS;
3337
d2be0de5 3338/* [perl #17376]: this appears to be premature, and results in code such as
c754c3d7 3339 C< our(%x); > executing in list mode rather than void mode */
d2be0de5 3340#if 0
09bef843
SB
3341 if (o->op_flags & OPf_PARENS)
3342 list(o);
95f0a2f1
SB
3343 else
3344 maybe_scalar = 1;
d2be0de5
YST
3345#else
3346 maybe_scalar = 1;
3347#endif
09bef843
SB
3348 if (attrs)
3349 SAVEFREEOP(attrs);
5f66b61c 3350 rops = NULL;
95f0a2f1
SB
3351 o = my_kid(o, attrs, &rops);
3352 if (rops) {
3353 if (maybe_scalar && o->op_type == OP_PADSV) {
2fcb4757 3354 o = scalar(op_append_list(OP_LIST, rops, o));
95f0a2f1
SB
3355 o->op_private |= OPpLVAL_INTRO;
3356 }
f5d1ed10
FC
3357 else {
3358 /* The listop in rops might have a pushmark at the beginning,
3359 which will mess up list assignment. */
3360 LISTOP * const lrops = (LISTOP *)rops; /* for brevity */
3361 if (rops->op_type == OP_LIST &&
3362 lrops->op_first && lrops->op_first->op_type == OP_PUSHMARK)
3363 {
3364 OP * const pushmark = lrops->op_first;
3253bf85
DM
3365 /* excise pushmark */
3366 op_sibling_splice(rops, NULL, 1, NULL);
f5d1ed10
FC
3367 op_free(pushmark);
3368 }
2fcb4757 3369 o = op_append_list(OP_LIST, o, rops);
f5d1ed10 3370 }
95f0a2f1 3371 }
12bd6ede
DM
3372 PL_parser->in_my = FALSE;
3373 PL_parser->in_my_stash = NULL;
eb64745e 3374 return o;
09bef843
SB
3375}
3376
3377OP *
864dbfa3 3378Perl_sawparens(pTHX_ OP *o)
79072805 3379{
96a5add6 3380 PERL_UNUSED_CONTEXT;
79072805
LW
3381 if (o)
3382 o->op_flags |= OPf_PARENS;
3383 return o;
3384}
3385
3386OP *
864dbfa3 3387Perl_bind_match(pTHX_ I32 type, OP *left, OP *right)
79072805 3388{
11343788 3389 OP *o;
59f00321 3390 bool ismatchop = 0;
1496a290
AL
3391 const OPCODE ltype = left->op_type;
3392 const OPCODE rtype = right->op_type;
79072805 3393
7918f24d
NC
3394 PERL_ARGS_ASSERT_BIND_MATCH;
3395
1496a290
AL
3396 if ( (ltype == OP_RV2AV || ltype == OP_RV2HV || ltype == OP_PADAV
3397 || ltype == OP_PADHV) && ckWARN(WARN_MISC))
041457d9 3398 {
1496a290 3399 const char * const desc
bb16bae8
FC
3400 = PL_op_desc[(
3401 rtype == OP_SUBST || rtype == OP_TRANS
3402 || rtype == OP_TRANSR
3403 )
666ea192 3404 ? (int)rtype : OP_MATCH];
c6771ab6 3405 const bool isary = ltype == OP_RV2AV || ltype == OP_PADAV;
c6771ab6 3406 SV * const name =
0920b7fa 3407 S_op_varname(aTHX_ left);
c6771ab6
FC
3408 if (name)
3409 Perl_warner(aTHX_ packWARN(WARN_MISC),
3410 "Applying %s to %"SVf" will act on scalar(%"SVf")",
c1f6cd39 3411 desc, SVfARG(name), SVfARG(name));
c6771ab6
FC
3412 else {
3413 const char * const sample = (isary
666ea192 3414 ? "@array" : "%hash");
c6771ab6 3415 Perl_warner(aTHX_ packWARN(WARN_MISC),
1c846c1f 3416 "Applying %s to %s will act on scalar(%s)",
599cee73 3417 desc, sample, sample);
c6771ab6 3418 }
2ae324a7
PP
3419 }
3420
1496a290 3421 if (rtype == OP_CONST &&
5cc9e5c9
RH
3422 cSVOPx(right)->op_private & OPpCONST_BARE &&
3423 cSVOPx(right)->op_private & OPpCONST_STRICT)
3424 {
3425 no_bareword_allowed(right);
3426 }
3427
bb16bae8 3428 /* !~ doesn't make sense with /r, so error on it for now */
4f4d7508
DC
3429 if (rtype == OP_SUBST && (cPMOPx(right)->op_pmflags & PMf_NONDESTRUCT) &&
3430 type == OP_NOT)
ce0e31fe 3431 /* diag_listed_as: Using !~ with %s doesn't make sense */
4f4d7508 3432 yyerror("Using !~ with s///r doesn't make sense");
bb16bae8 3433 if (rtype == OP_TRANSR && type == OP_NOT)
ce0e31fe 3434 /* diag_listed_as: Using !~ with %s doesn't make sense */
bb16bae8 3435 yyerror("Using !~ with tr///r doesn't make sense");
4f4d7508 3436
2474a784
FC
3437 ismatchop = (rtype == OP_MATCH ||
3438 rtype == OP_SUBST ||
bb16bae8 3439 rtype == OP_TRANS || rtype == OP_TRANSR)
2474a784 3440 && !(right->op_flags & OPf_SPECIAL);
59f00321
RGS
3441 if (ismatchop && right->op_private & OPpTARGET_MY) {
3442 right->op_targ = 0;
3443 right->op_private &= ~OPpTARGET_MY;
3444 }
3445 if (!(right->op_flags & OPf_STACKED) && ismatchop) {
1496a290
AL
3446 OP *newleft;
3447
79072805 3448 right->op_flags |= OPf_STACKED;
bb16bae8 3449 if (rtype != OP_MATCH && rtype != OP_TRANSR &&
1496a290 3450 ! (rtype == OP_TRANS &&
4f4d7508
DC
3451 right->op_private & OPpTRANS_IDENTICAL) &&
3452 ! (rtype == OP_SUBST &&
3453 (cPMOPx(right)->op_pmflags & PMf_NONDESTRUCT)))
3ad73efd 3454 newleft = op_lvalue(left, rtype);
1496a290
AL
3455 else
3456 newleft = left;
bb16bae8 3457 if (right->op_type == OP_TRANS || right->op_type == OP_TRANSR)
1496a290 3458 o = newBINOP(OP_NULL, OPf_STACKED, scalar(newleft), right);
79072805 3459 else
2fcb4757 3460 o = op_prepend_elem(rtype, scalar(newleft), right);
79072805 3461 if (type == OP_NOT)
11343788
MB
3462 return newUNOP(OP_NOT, 0, scalar(o));
3463 return o;
79072805
LW
3464 }
3465 else
3466 return bind_match(type, left,
d63c20f2 3467 pmruntime(newPMOP(OP_MATCH, 0), right, 0, 0));
79072805
LW
3468}
3469
3470OP *
864dbfa3 3471Perl_invert(pTHX_ OP *o)
79072805 3472{
11343788 3473 if (!o)
1d866c12 3474 return NULL;
11343788 3475 return newUNOP(OP_NOT, OPf_SPECIAL, scalar(o));
79072805
LW
3476}
3477
3ad73efd
Z
3478/*
3479=for apidoc Amx|OP *|op_scope|OP *o
3480
3481Wraps up an op tree with some additional ops so that at runtime a dynamic
3482scope will be created. The original ops run in the new dynamic scope,
3483and then, provided that they exit normally, the scope will be unwound.
3484The additional ops used to create and unwind the dynamic scope will
3485normally be an C<enter>/C<leave> pair, but a C<scope> op may be used
3486instead if the ops are simple enough to not need the full dynamic scope
3487structure.
3488
3489=cut
3490*/
3491
79072805 3492OP *
3ad73efd 3493Perl_op_scope(pTHX_ OP *o)
79072805 3494{
27da23d5 3495 dVAR;
79072805 3496 if (o) {
284167a5 3497 if (o->op_flags & OPf_PARENS || PERLDB_NOOPT || TAINTING_get) {
2fcb4757 3498 o = op_prepend_elem(OP_LINESEQ, newOP(OP_ENTER, 0), o);
463ee0b2 3499 o->op_type = OP_LEAVE;
22c35a8c 3500 o->op_ppaddr = PL_ppaddr[OP_LEAVE];
463ee0b2 3501 }
fdb22418
HS
3502 else if (o->op_type == OP_LINESEQ) {
3503 OP *kid;
3504 o->op_type = OP_SCOPE;
3505 o->op_ppaddr = PL_ppaddr[OP_SCOPE];
3506 kid = ((LISTOP*)o)->op_first;
59110972 3507 if (kid->op_type == OP_NEXTSTATE || kid->op_type == OP_DBSTATE) {
fdb22418 3508 op_null(kid);
59110972
RH
3509
3510 /* The following deals with things like 'do {1 for 1}' */
1ed44841 3511 kid = OP_SIBLING(kid);
59110972
RH
3512 if (kid &&
3513 (kid->op_type == OP_NEXTSTATE || kid->op_type == OP_DBSTATE))
3514 op_null(kid);
3515 }
463ee0b2 3516 }
fdb22418 3517 else
5f66b61c 3518 o = newLISTOP(OP_SCOPE, 0, o, NULL);
79072805
LW
3519 }
3520 return o;
3521}
1930840b 3522
705fe0e5
FC
3523OP *
3524Perl_op_unscope(pTHX_ OP *o)
3525{
3526 if (o && o->op_type == OP_LINESEQ) {
3527 OP *kid = cLISTOPo->op_first;
1ed44841 3528 for(; kid; kid = OP_SIBLING(kid))
705fe0e5
FC
3529 if (kid->op_type == OP_NEXTSTATE || kid->op_type == OP_DBSTATE)
3530 op_null(kid);
3531 }
3532 return o;
3533}
3534
a0d0e21e 3535int
864dbfa3 3536Perl_block_start(pTHX_ int full)
79072805 3537{
73d840c0 3538 const int retval = PL_savestack_ix;
1930840b 3539
dd2155a4 3540 pad_block_start(full);
b3ac6de7 3541 SAVEHINTS();
3280af22 3542 PL_hints &= ~HINT_BLOCK_SCOPE;
68da3b2f 3543 SAVECOMPILEWARNINGS();
72dc9ed5 3544 PL_compiling.cop_warnings = DUP_WARNINGS(PL_compiling.cop_warnings);
1930840b 3545
a88d97bf 3546 CALL_BLOCK_HOOKS(bhk_start, full);
1930840b 3547
a0d0e21e
LW
3548 return retval;
3549}
3550
3551OP*
864dbfa3 3552Perl_block_end(pTHX_ I32 floor, OP *seq)
a0d0e21e 3553{
6867be6d 3554 const int needblockscope = PL_hints & HINT_BLOCK_SCOPE;
1930840b 3555 OP* retval = scalarseq(seq);
6d5c2147 3556 OP *o;
1930840b 3557
a88d97bf 3558 CALL_BLOCK_HOOKS(bhk_pre_end, &retval);
1930840b 3559
e9818f4e 3560 LEAVE_SCOPE(floor);
a0d0e21e 3561 if (needblockscope)
3280af22 3562 PL_hints |= HINT_BLOCK_SCOPE; /* propagate out */
6d5c2147
FC
3563 o = pad_leavemy();
3564
3565 if (o) {
3566 /* pad_leavemy has created a sequence of introcv ops for all my
3567 subs declared in the block. We have to replicate that list with
3568 clonecv ops, to deal with this situation:
3569
3570 sub {
3571 my sub s1;
3572 my sub s2;
3573 sub s1 { state sub foo { \&s2 } }
3574 }->()
3575
3576 Originally, I was going to have introcv clone the CV and turn
3577 off the stale flag. Since &s1 is declared before &s2, the
3578 introcv op for &s1 is executed (on sub entry) before the one for
3579 &s2. But the &foo sub inside &s1 (which is cloned when &s1 is
3580 cloned, since it is a state sub) closes over &s2 and expects
3581 to see it in its outer CV’s pad. If the introcv op clones &s1,
3582 then &s2 is still marked stale. Since &s1 is not active, and
3583 &foo closes over &s1’s implicit entry for &s2, we get a ‘Varia-
3584 ble will not stay shared’ warning. Because it is the same stub
3585 that will be used when the introcv op for &s2 is executed, clos-
3586 ing over it is safe. Hence, we have to turn off the stale flag
3587 on all lexical subs in the block before we clone any of them.
3588 Hence, having introcv clone the sub cannot work. So we create a
3589 list of ops like this:
3590
3591 lineseq
3592 |
3593 +-- introcv
3594 |
3595 +-- introcv
3596 |
3597 +-- introcv
3598 |
3599 .
3600 .
3601 .
3602 |
3603 +-- clonecv
3604 |
3605 +-- clonecv
3606 |
3607 +-- clonecv
3608 |
3609 .
3610 .
3611 .
3612 */
3613 OP *kid = o->op_flags & OPf_KIDS ? cLISTOPo->op_first : o;
3614 OP * const last = o->op_flags & OPf_KIDS ? cLISTOPo->op_last : o;
1ed44841 3615 for (;; kid = OP_SIBLING(kid)) {
6d5c2147
FC
3616 OP *newkid = newOP(OP_CLONECV, 0);
3617 newkid->op_targ = kid->op_targ;
3618 o = op_append_elem(OP_LINESEQ, o, newkid);
3619 if (kid == last) break;
3620 }
3621 retval = op_prepend_elem(OP_LINESEQ, o, retval);
3622 }
1930840b 3623
a88d97bf 3624 CALL_BLOCK_HOOKS(bhk_post_end, &retval);
1930840b 3625
a0d0e21e
LW
3626 return retval;
3627}
3628
fd85fad2
BM
3629/*
3630=head1 Compile-time scope hooks
3631
3e4ddde5 3632=for apidoc Aox||blockhook_register
fd85fad2
BM
3633
3634Register a set of hooks to be called when the Perl lexical scope changes
72d33970 3635at compile time. See L<perlguts/"Compile-time scope hooks">.
fd85fad2
BM
3636
3637=cut
3638*/
3639
bb6c22e7
BM
3640void
3641Perl_blockhook_register(pTHX_ BHK *hk)
3642{
3643 PERL_ARGS_ASSERT_BLOCKHOOK_REGISTER;
3644
3645 Perl_av_create_and_push(aTHX_ &PL_blockhoo