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move the closing ) out of the #ifdef USE_ITHREADS to avoid confusing tools
[perl5.git] / op.c
CommitLineData
4b88f280 1#line 2 "op.c"
a0d0e21e 2/* op.c
79072805 3 *
1129b882
NC
4 * Copyright (C) 1991, 1992, 1993, 1994, 1995, 1996, 1997, 1998, 1999, 2000,
5 * 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008 by Larry Wall and others
79072805
LW
6 *
7 * You may distribute under the terms of either the GNU General Public
8 * License or the Artistic License, as specified in the README file.
9 *
a0d0e21e
LW
10 */
11
12/*
4ac71550
TC
13 * 'You see: Mr. Drogo, he married poor Miss Primula Brandybuck. She was
14 * our Mr. Bilbo's first cousin on the mother's side (her mother being the
15 * youngest of the Old Took's daughters); and Mr. Drogo was his second
16 * cousin. So Mr. Frodo is his first *and* second cousin, once removed
17 * either way, as the saying is, if you follow me.' --the Gaffer
18 *
19 * [p.23 of _The Lord of the Rings_, I/i: "A Long-Expected Party"]
79072805
LW
20 */
21
166f8a29
DM
22/* This file contains the functions that create, manipulate and optimize
23 * the OP structures that hold a compiled perl program.
24 *
25 * A Perl program is compiled into a tree of OPs. Each op contains
26 * structural pointers (eg to its siblings and the next op in the
27 * execution sequence), a pointer to the function that would execute the
28 * op, plus any data specific to that op. For example, an OP_CONST op
29 * points to the pp_const() function and to an SV containing the constant
30 * value. When pp_const() is executed, its job is to push that SV onto the
31 * stack.
32 *
33 * OPs are mainly created by the newFOO() functions, which are mainly
34 * called from the parser (in perly.y) as the code is parsed. For example
35 * the Perl code $a + $b * $c would cause the equivalent of the following
36 * to be called (oversimplifying a bit):
37 *
38 * newBINOP(OP_ADD, flags,
39 * newSVREF($a),
40 * newBINOP(OP_MULTIPLY, flags, newSVREF($b), newSVREF($c))
41 * )
42 *
43 * Note that during the build of miniperl, a temporary copy of this file
44 * is made, called opmini.c.
45 */
ccfc67b7 46
61b743bb
DM
47/*
48Perl's compiler is essentially a 3-pass compiler with interleaved phases:
49
50 A bottom-up pass
51 A top-down pass
52 An execution-order pass
53
54The bottom-up pass is represented by all the "newOP" routines and
55the ck_ routines. The bottom-upness is actually driven by yacc.
56So at the point that a ck_ routine fires, we have no idea what the
57context is, either upward in the syntax tree, or either forward or
58backward in the execution order. (The bottom-up parser builds that
59part of the execution order it knows about, but if you follow the "next"
60links around, you'll find it's actually a closed loop through the
ef9da979 61top level node.)
61b743bb
DM
62
63Whenever the bottom-up parser gets to a node that supplies context to
64its components, it invokes that portion of the top-down pass that applies
65to that part of the subtree (and marks the top node as processed, so
66if a node further up supplies context, it doesn't have to take the
67plunge again). As a particular subcase of this, as the new node is
68built, it takes all the closed execution loops of its subcomponents
69and links them into a new closed loop for the higher level node. But
70it's still not the real execution order.
71
72The actual execution order is not known till we get a grammar reduction
73to a top-level unit like a subroutine or file that will be called by
74"name" rather than via a "next" pointer. At that point, we can call
75into peep() to do that code's portion of the 3rd pass. It has to be
76recursive, but it's recursive on basic blocks, not on tree nodes.
77*/
78
06e0342d 79/* To implement user lexical pragmas, there needs to be a way at run time to
b3ca2e83
NC
80 get the compile time state of %^H for that block. Storing %^H in every
81 block (or even COP) would be very expensive, so a different approach is
82 taken. The (running) state of %^H is serialised into a tree of HE-like
83 structs. Stores into %^H are chained onto the current leaf as a struct
84 refcounted_he * with the key and the value. Deletes from %^H are saved
85 with a value of PL_sv_placeholder. The state of %^H at any point can be
86 turned back into a regular HV by walking back up the tree from that point's
06e0342d 87 leaf, ignoring any key you've already seen (placeholder or not), storing
b3ca2e83
NC
88 the rest into the HV structure, then removing the placeholders. Hence
89 memory is only used to store the %^H deltas from the enclosing COP, rather
90 than the entire %^H on each COP.
91
92 To cause actions on %^H to write out the serialisation records, it has
93 magic type 'H'. This magic (itself) does nothing, but its presence causes
94 the values to gain magic type 'h', which has entries for set and clear.
c28fe1ec 95 C<Perl_magic_sethint> updates C<PL_compiling.cop_hints_hash> with a store
34795b44 96 record, with deletes written by C<Perl_magic_clearhint>. C<SAVEHINTS>
c28fe1ec
NC
97 saves the current C<PL_compiling.cop_hints_hash> on the save stack, so that
98 it will be correctly restored when any inner compiling scope is exited.
b3ca2e83
NC
99*/
100
79072805 101#include "EXTERN.h"
864dbfa3 102#define PERL_IN_OP_C
79072805 103#include "perl.h"
77ca0c92 104#include "keywords.h"
2846acbf 105#include "feature.h"
74529a43 106#include "regcomp.h"
79072805 107
16c91539 108#define CALL_PEEP(o) PL_peepp(aTHX_ o)
1a0a2ba9 109#define CALL_RPEEP(o) PL_rpeepp(aTHX_ o)
16c91539 110#define CALL_OPFREEHOOK(o) if (PL_opfreehook) PL_opfreehook(aTHX_ o)
a2efc822 111
aa9d1253
TC
112/* Used to avoid recursion through the op tree in scalarvoid() and
113 op_free()
114*/
115
116#define DEFERRED_OP_STEP 100
117#define DEFER_OP(o) \
118 STMT_START { \
119 if (UNLIKELY(defer_ix == (defer_stack_alloc-1))) { \
120 defer_stack_alloc += DEFERRED_OP_STEP; \
121 assert(defer_stack_alloc > 0); \
122 Renew(defer_stack, defer_stack_alloc, OP *); \
123 } \
124 defer_stack[++defer_ix] = o; \
125 } STMT_END
126
127#define POP_DEFERRED_OP() (defer_ix >= 0 ? defer_stack[defer_ix--] : (OP *)NULL)
128
72621f84
DM
129/* remove any leading "empty" ops from the op_next chain whose first
130 * node's address is stored in op_p. Store the updated address of the
131 * first node in op_p.
132 */
133
134STATIC void
dc3bf405 135S_prune_chain_head(OP** op_p)
72621f84
DM
136{
137 while (*op_p
138 && ( (*op_p)->op_type == OP_NULL
139 || (*op_p)->op_type == OP_SCOPE
140 || (*op_p)->op_type == OP_SCALAR
141 || (*op_p)->op_type == OP_LINESEQ)
142 )
143 *op_p = (*op_p)->op_next;
144}
145
146
8be227ab
FC
147/* See the explanatory comments above struct opslab in op.h. */
148
7aef8e5b 149#ifdef PERL_DEBUG_READONLY_OPS
3107b51f
FC
150# define PERL_SLAB_SIZE 128
151# define PERL_MAX_SLAB_SIZE 4096
152# include <sys/mman.h>
7aef8e5b 153#endif
3107b51f 154
7aef8e5b 155#ifndef PERL_SLAB_SIZE
8be227ab 156# define PERL_SLAB_SIZE 64
7aef8e5b
FC
157#endif
158#ifndef PERL_MAX_SLAB_SIZE
e6cee8c0 159# define PERL_MAX_SLAB_SIZE 2048
7aef8e5b 160#endif
8be227ab
FC
161
162/* rounds up to nearest pointer */
7aef8e5b
FC
163#define SIZE_TO_PSIZE(x) (((x) + sizeof(I32 *) - 1)/sizeof(I32 *))
164#define DIFF(o,p) ((size_t)((I32 **)(p) - (I32**)(o)))
8be227ab
FC
165
166static OPSLAB *
167S_new_slab(pTHX_ size_t sz)
168{
7aef8e5b 169#ifdef PERL_DEBUG_READONLY_OPS
3107b51f
FC
170 OPSLAB *slab = (OPSLAB *) mmap(0, sz * sizeof(I32 *),
171 PROT_READ|PROT_WRITE,
172 MAP_ANON|MAP_PRIVATE, -1, 0);
173 DEBUG_m(PerlIO_printf(Perl_debug_log, "mapped %lu at %p\n",
174 (unsigned long) sz, slab));
175 if (slab == MAP_FAILED) {
176 perror("mmap failed");
177 abort();
178 }
179 slab->opslab_size = (U16)sz;
7aef8e5b 180#else
8be227ab 181 OPSLAB *slab = (OPSLAB *)PerlMemShared_calloc(sz, sizeof(I32 *));
7aef8e5b 182#endif
dc3bf405
BF
183#ifndef WIN32
184 /* The context is unused in non-Windows */
185 PERL_UNUSED_CONTEXT;
186#endif
8be227ab
FC
187 slab->opslab_first = (OPSLOT *)((I32 **)slab + sz - 1);
188 return slab;
189}
190
e7372881
FC
191/* requires double parens and aTHX_ */
192#define DEBUG_S_warn(args) \
193 DEBUG_S( \
194 PerlIO_printf(Perl_debug_log, "%s", SvPVx_nolen(Perl_mess args)) \
195 )
196
8be227ab
FC
197void *
198Perl_Slab_Alloc(pTHX_ size_t sz)
199{
8be227ab
FC
200 OPSLAB *slab;
201 OPSLAB *slab2;
202 OPSLOT *slot;
203 OP *o;
5cb52f30 204 size_t opsz, space;
8be227ab 205
2073970f
NC
206 /* We only allocate ops from the slab during subroutine compilation.
207 We find the slab via PL_compcv, hence that must be non-NULL. It could
208 also be pointing to a subroutine which is now fully set up (CvROOT()
209 pointing to the top of the optree for that sub), or a subroutine
210 which isn't using the slab allocator. If our sanity checks aren't met,
211 don't use a slab, but allocate the OP directly from the heap. */
8be227ab
FC
212 if (!PL_compcv || CvROOT(PL_compcv)
213 || (CvSTART(PL_compcv) && !CvSLABBED(PL_compcv)))
29e61fd9
DM
214 {
215 o = (OP*)PerlMemShared_calloc(1, sz);
216 goto gotit;
217 }
8be227ab 218
2073970f
NC
219 /* While the subroutine is under construction, the slabs are accessed via
220 CvSTART(), to avoid needing to expand PVCV by one pointer for something
221 unneeded at runtime. Once a subroutine is constructed, the slabs are
222 accessed via CvROOT(). So if CvSTART() is NULL, no slab has been
223 allocated yet. See the commit message for 8be227ab5eaa23f2 for more
224 details. */
225 if (!CvSTART(PL_compcv)) {
8be227ab
FC
226 CvSTART(PL_compcv) =
227 (OP *)(slab = S_new_slab(aTHX_ PERL_SLAB_SIZE));
228 CvSLABBED_on(PL_compcv);
229 slab->opslab_refcnt = 2; /* one for the CV; one for the new OP */
230 }
231 else ++(slab = (OPSLAB *)CvSTART(PL_compcv))->opslab_refcnt;
232
5cb52f30
FC
233 opsz = SIZE_TO_PSIZE(sz);
234 sz = opsz + OPSLOT_HEADER_P;
8be227ab 235
2073970f
NC
236 /* The slabs maintain a free list of OPs. In particular, constant folding
237 will free up OPs, so it makes sense to re-use them where possible. A
238 freed up slot is used in preference to a new allocation. */
8be227ab
FC
239 if (slab->opslab_freed) {
240 OP **too = &slab->opslab_freed;
241 o = *too;
eb212a1c 242 DEBUG_S_warn((aTHX_ "found free op at %p, slab %p", (void*)o, (void*)slab));
8be227ab 243 while (o && DIFF(OpSLOT(o), OpSLOT(o)->opslot_next) < sz) {
e7372881 244 DEBUG_S_warn((aTHX_ "Alas! too small"));
8be227ab 245 o = *(too = &o->op_next);
eb212a1c 246 if (o) { DEBUG_S_warn((aTHX_ "found another free op at %p", (void*)o)); }
8be227ab
FC
247 }
248 if (o) {
249 *too = o->op_next;
5cb52f30 250 Zero(o, opsz, I32 *);
8be227ab 251 o->op_slabbed = 1;
29e61fd9 252 goto gotit;
8be227ab
FC
253 }
254 }
255
7aef8e5b 256#define INIT_OPSLOT \
8be227ab
FC
257 slot->opslot_slab = slab; \
258 slot->opslot_next = slab2->opslab_first; \
259 slab2->opslab_first = slot; \
260 o = &slot->opslot_op; \
261 o->op_slabbed = 1
262
263 /* The partially-filled slab is next in the chain. */
264 slab2 = slab->opslab_next ? slab->opslab_next : slab;
265 if ((space = DIFF(&slab2->opslab_slots, slab2->opslab_first)) < sz) {
266 /* Remaining space is too small. */
267
8be227ab
FC
268 /* If we can fit a BASEOP, add it to the free chain, so as not
269 to waste it. */
270 if (space >= SIZE_TO_PSIZE(sizeof(OP)) + OPSLOT_HEADER_P) {
271 slot = &slab2->opslab_slots;
272 INIT_OPSLOT;
273 o->op_type = OP_FREED;
274 o->op_next = slab->opslab_freed;
275 slab->opslab_freed = o;
276 }
277
278 /* Create a new slab. Make this one twice as big. */
279 slot = slab2->opslab_first;
280 while (slot->opslot_next) slot = slot->opslot_next;
af7751f6
FC
281 slab2 = S_new_slab(aTHX_
282 (DIFF(slab2, slot)+1)*2 > PERL_MAX_SLAB_SIZE
e6cee8c0 283 ? PERL_MAX_SLAB_SIZE
af7751f6 284 : (DIFF(slab2, slot)+1)*2);
9963ffa2
FC
285 slab2->opslab_next = slab->opslab_next;
286 slab->opslab_next = slab2;
8be227ab
FC
287 }
288 assert(DIFF(&slab2->opslab_slots, slab2->opslab_first) >= sz);
289
290 /* Create a new op slot */
291 slot = (OPSLOT *)((I32 **)slab2->opslab_first - sz);
292 assert(slot >= &slab2->opslab_slots);
51c777ca
FC
293 if (DIFF(&slab2->opslab_slots, slot)
294 < SIZE_TO_PSIZE(sizeof(OP)) + OPSLOT_HEADER_P)
295 slot = &slab2->opslab_slots;
8be227ab 296 INIT_OPSLOT;
eb212a1c 297 DEBUG_S_warn((aTHX_ "allocating op at %p, slab %p", (void*)o, (void*)slab));
29e61fd9
DM
298
299 gotit:
300 /* lastsib == 1, op_sibling == 0 implies a solitary unattached op */
301 o->op_lastsib = 1;
302 assert(!o->op_sibling);
303
8be227ab
FC
304 return (void *)o;
305}
306
7aef8e5b 307#undef INIT_OPSLOT
8be227ab 308
7aef8e5b 309#ifdef PERL_DEBUG_READONLY_OPS
3107b51f
FC
310void
311Perl_Slab_to_ro(pTHX_ OPSLAB *slab)
312{
313 PERL_ARGS_ASSERT_SLAB_TO_RO;
314
315 if (slab->opslab_readonly) return;
316 slab->opslab_readonly = 1;
317 for (; slab; slab = slab->opslab_next) {
318 /*DEBUG_U(PerlIO_printf(Perl_debug_log,"mprotect ->ro %lu at %p\n",
319 (unsigned long) slab->opslab_size, slab));*/
320 if (mprotect(slab, slab->opslab_size * sizeof(I32 *), PROT_READ))
321 Perl_warn(aTHX_ "mprotect for %p %lu failed with %d", slab,
322 (unsigned long)slab->opslab_size, errno);
323 }
324}
325
7bbbc3c0
NC
326void
327Perl_Slab_to_rw(pTHX_ OPSLAB *const slab)
3107b51f 328{
3107b51f
FC
329 OPSLAB *slab2;
330
331 PERL_ARGS_ASSERT_SLAB_TO_RW;
332
3107b51f
FC
333 if (!slab->opslab_readonly) return;
334 slab2 = slab;
335 for (; slab2; slab2 = slab2->opslab_next) {
336 /*DEBUG_U(PerlIO_printf(Perl_debug_log,"mprotect ->rw %lu at %p\n",
337 (unsigned long) size, slab2));*/
338 if (mprotect((void *)slab2, slab2->opslab_size * sizeof(I32 *),
339 PROT_READ|PROT_WRITE)) {
340 Perl_warn(aTHX_ "mprotect RW for %p %lu failed with %d", slab,
341 (unsigned long)slab2->opslab_size, errno);
342 }
343 }
344 slab->opslab_readonly = 0;
345}
346
347#else
9e4d7a13 348# define Slab_to_rw(op) NOOP
3107b51f
FC
349#endif
350
8be227ab
FC
351/* This cannot possibly be right, but it was copied from the old slab
352 allocator, to which it was originally added, without explanation, in
353 commit 083fcd5. */
7aef8e5b 354#ifdef NETWARE
8be227ab 355# define PerlMemShared PerlMem
7aef8e5b 356#endif
8be227ab
FC
357
358void
359Perl_Slab_Free(pTHX_ void *op)
360{
361 OP * const o = (OP *)op;
362 OPSLAB *slab;
363
364 PERL_ARGS_ASSERT_SLAB_FREE;
365
366 if (!o->op_slabbed) {
90840c5d
RU
367 if (!o->op_static)
368 PerlMemShared_free(op);
8be227ab
FC
369 return;
370 }
371
372 slab = OpSLAB(o);
373 /* If this op is already freed, our refcount will get screwy. */
374 assert(o->op_type != OP_FREED);
375 o->op_type = OP_FREED;
376 o->op_next = slab->opslab_freed;
377 slab->opslab_freed = o;
eb212a1c 378 DEBUG_S_warn((aTHX_ "free op at %p, recorded in slab %p", (void*)o, (void*)slab));
8be227ab
FC
379 OpslabREFCNT_dec_padok(slab);
380}
381
382void
383Perl_opslab_free_nopad(pTHX_ OPSLAB *slab)
384{
8be227ab
FC
385 const bool havepad = !!PL_comppad;
386 PERL_ARGS_ASSERT_OPSLAB_FREE_NOPAD;
387 if (havepad) {
388 ENTER;
389 PAD_SAVE_SETNULLPAD();
390 }
391 opslab_free(slab);
392 if (havepad) LEAVE;
393}
394
395void
396Perl_opslab_free(pTHX_ OPSLAB *slab)
397{
398 OPSLAB *slab2;
399 PERL_ARGS_ASSERT_OPSLAB_FREE;
81611534 400 PERL_UNUSED_CONTEXT;
eb212a1c 401 DEBUG_S_warn((aTHX_ "freeing slab %p", (void*)slab));
8be227ab
FC
402 assert(slab->opslab_refcnt == 1);
403 for (; slab; slab = slab2) {
404 slab2 = slab->opslab_next;
7aef8e5b 405#ifdef DEBUGGING
8be227ab 406 slab->opslab_refcnt = ~(size_t)0;
7aef8e5b
FC
407#endif
408#ifdef PERL_DEBUG_READONLY_OPS
3107b51f 409 DEBUG_m(PerlIO_printf(Perl_debug_log, "Deallocate slab at %p\n",
eb212a1c 410 (void*)slab));
3107b51f
FC
411 if (munmap(slab, slab->opslab_size * sizeof(I32 *))) {
412 perror("munmap failed");
413 abort();
414 }
7aef8e5b 415#else
8be227ab 416 PerlMemShared_free(slab);
7aef8e5b 417#endif
8be227ab
FC
418 }
419}
420
421void
422Perl_opslab_force_free(pTHX_ OPSLAB *slab)
423{
424 OPSLAB *slab2;
425 OPSLOT *slot;
7aef8e5b 426#ifdef DEBUGGING
8be227ab 427 size_t savestack_count = 0;
7aef8e5b 428#endif
8be227ab
FC
429 PERL_ARGS_ASSERT_OPSLAB_FORCE_FREE;
430 slab2 = slab;
431 do {
432 for (slot = slab2->opslab_first;
433 slot->opslot_next;
434 slot = slot->opslot_next) {
435 if (slot->opslot_op.op_type != OP_FREED
436 && !(slot->opslot_op.op_savefree
7aef8e5b 437#ifdef DEBUGGING
8be227ab 438 && ++savestack_count
7aef8e5b 439#endif
8be227ab
FC
440 )
441 ) {
442 assert(slot->opslot_op.op_slabbed);
8be227ab 443 op_free(&slot->opslot_op);
3bf28c7e 444 if (slab->opslab_refcnt == 1) goto free;
8be227ab
FC
445 }
446 }
447 } while ((slab2 = slab2->opslab_next));
448 /* > 1 because the CV still holds a reference count. */
449 if (slab->opslab_refcnt > 1) { /* still referenced by the savestack */
7aef8e5b 450#ifdef DEBUGGING
8be227ab 451 assert(savestack_count == slab->opslab_refcnt-1);
7aef8e5b 452#endif
ee5ee853
FC
453 /* Remove the CV’s reference count. */
454 slab->opslab_refcnt--;
8be227ab
FC
455 return;
456 }
457 free:
458 opslab_free(slab);
459}
460
3107b51f
FC
461#ifdef PERL_DEBUG_READONLY_OPS
462OP *
463Perl_op_refcnt_inc(pTHX_ OP *o)
464{
465 if(o) {
372eab01
NC
466 OPSLAB *const slab = o->op_slabbed ? OpSLAB(o) : NULL;
467 if (slab && slab->opslab_readonly) {
83519873 468 Slab_to_rw(slab);
372eab01
NC
469 ++o->op_targ;
470 Slab_to_ro(slab);
471 } else {
472 ++o->op_targ;
473 }
3107b51f
FC
474 }
475 return o;
476
477}
478
479PADOFFSET
480Perl_op_refcnt_dec(pTHX_ OP *o)
481{
372eab01
NC
482 PADOFFSET result;
483 OPSLAB *const slab = o->op_slabbed ? OpSLAB(o) : NULL;
484
3107b51f 485 PERL_ARGS_ASSERT_OP_REFCNT_DEC;
372eab01
NC
486
487 if (slab && slab->opslab_readonly) {
83519873 488 Slab_to_rw(slab);
372eab01
NC
489 result = --o->op_targ;
490 Slab_to_ro(slab);
491 } else {
492 result = --o->op_targ;
493 }
494 return result;
3107b51f
FC
495}
496#endif
e50aee73 497/*
ce6f1cbc 498 * In the following definition, the ", (OP*)0" is just to make the compiler
a5f75d66 499 * think the expression is of the right type: croak actually does a Siglongjmp.
e50aee73 500 */
11343788 501#define CHECKOP(type,o) \
ce6f1cbc 502 ((PL_op_mask && PL_op_mask[type]) \
5dc0d613 503 ? ( op_free((OP*)o), \
cb77fdf0 504 Perl_croak(aTHX_ "'%s' trapped by operation mask", PL_op_desc[type]), \
ce6f1cbc 505 (OP*)0 ) \
16c91539 506 : PL_check[type](aTHX_ (OP*)o))
e50aee73 507
e6438c1a 508#define RETURN_UNLIMITED_NUMBER (PERL_INT_MAX / 2)
c53d7c7d 509
cba5a3b0
DG
510#define CHANGE_TYPE(o,type) \
511 STMT_START { \
512 o->op_type = (OPCODE)type; \
513 o->op_ppaddr = PL_ppaddr[type]; \
514 } STMT_END
515
76e3520e 516STATIC OP *
cea2e8a9 517S_no_fh_allowed(pTHX_ OP *o)
79072805 518{
7918f24d
NC
519 PERL_ARGS_ASSERT_NO_FH_ALLOWED;
520
cea2e8a9 521 yyerror(Perl_form(aTHX_ "Missing comma after first argument to %s function",
53e06cf0 522 OP_DESC(o)));
11343788 523 return o;
79072805
LW
524}
525
76e3520e 526STATIC OP *
ce16c625
BF
527S_too_few_arguments_pv(pTHX_ OP *o, const char* name, U32 flags)
528{
529 PERL_ARGS_ASSERT_TOO_FEW_ARGUMENTS_PV;
530 yyerror_pv(Perl_form(aTHX_ "Not enough arguments for %s", name), flags);
531 return o;
532}
533
534STATIC OP *
535S_too_many_arguments_pv(pTHX_ OP *o, const char *name, U32 flags)
536{
537 PERL_ARGS_ASSERT_TOO_MANY_ARGUMENTS_PV;
7918f24d 538
ce16c625 539 yyerror_pv(Perl_form(aTHX_ "Too many arguments for %s", name), flags);
11343788 540 return o;
79072805
LW
541}
542
76e3520e 543STATIC void
ce16c625 544S_bad_type_pv(pTHX_ I32 n, const char *t, const char *name, U32 flags, const OP *kid)
8990e307 545{
ce16c625
BF
546 PERL_ARGS_ASSERT_BAD_TYPE_PV;
547
548 yyerror_pv(Perl_form(aTHX_ "Type of arg %d to %s must be %s (not %s)",
549 (int)n, name, t, OP_DESC(kid)), flags);
550}
7918f24d 551
ce16c625 552STATIC void
7b3b0904 553S_bad_type_gv(pTHX_ I32 n, const char *t, GV *gv, U32 flags, const OP *kid)
ce16c625 554{
ecf05a58 555 SV * const namesv = cv_name((CV *)gv, NULL, 0);
7b3b0904 556 PERL_ARGS_ASSERT_BAD_TYPE_GV;
ce16c625
BF
557
558 yyerror_pv(Perl_form(aTHX_ "Type of arg %d to %"SVf" must be %s (not %s)",
559 (int)n, SVfARG(namesv), t, OP_DESC(kid)), SvUTF8(namesv) | flags);
8990e307
LW
560}
561
7a52d87a 562STATIC void
eb796c7f 563S_no_bareword_allowed(pTHX_ OP *o)
7a52d87a 564{
7918f24d
NC
565 PERL_ARGS_ASSERT_NO_BAREWORD_ALLOWED;
566
5a844595 567 qerror(Perl_mess(aTHX_
35c1215d 568 "Bareword \"%"SVf"\" not allowed while \"strict subs\" in use",
be2597df 569 SVfARG(cSVOPo_sv)));
eb796c7f 570 o->op_private &= ~OPpCONST_STRICT; /* prevent warning twice about the same OP */
7a52d87a
GS
571}
572
79072805
LW
573/* "register" allocation */
574
575PADOFFSET
d6447115 576Perl_allocmy(pTHX_ const char *const name, const STRLEN len, const U32 flags)
93a17b20 577{
a0d0e21e 578 PADOFFSET off;
12bd6ede 579 const bool is_our = (PL_parser->in_my == KEY_our);
a0d0e21e 580
7918f24d
NC
581 PERL_ARGS_ASSERT_ALLOCMY;
582
48d0d1be 583 if (flags & ~SVf_UTF8)
d6447115
NC
584 Perl_croak(aTHX_ "panic: allocmy illegal flag bits 0x%" UVxf,
585 (UV)flags);
586
59f00321 587 /* complain about "my $<special_var>" etc etc */
d6447115 588 if (len &&
3edf23ff 589 !(is_our ||
155aba94 590 isALPHA(name[1]) ||
b14845b4 591 ((flags & SVf_UTF8) && isIDFIRST_utf8((U8 *)name+1)) ||
d6447115 592 (name[1] == '_' && (*name == '$' || len > 2))))
834a4ddd 593 {
b14845b4
FC
594 if (!(flags & SVf_UTF8 && UTF8_IS_START(name[1]))
595 && (!isPRINT(name[1]) || strchr("\t\n\r\f", name[1]))) {
d6447115
NC
596 yyerror(Perl_form(aTHX_ "Can't use global %c^%c%.*s in \"%s\"",
597 name[0], toCTRL(name[1]), (int)(len - 2), name + 2,
aab6a793 598 PL_parser->in_my == KEY_state ? "state" : "my"));
d1544d85 599 } else {
ce16c625
BF
600 yyerror_pv(Perl_form(aTHX_ "Can't use global %.*s in \"%s\"", (int) len, name,
601 PL_parser->in_my == KEY_state ? "state" : "my"), flags & SVf_UTF8);
46fc3d4c 602 }
a0d0e21e 603 }
4055dbce
RS
604 else if (len == 2 && name[1] == '_' && !is_our)
605 /* diag_listed_as: Use of my $_ is experimental */
606 Perl_ck_warner_d(aTHX_ packWARN(WARN_EXPERIMENTAL__LEXICAL_TOPIC),
607 "Use of %s $_ is experimental",
608 PL_parser->in_my == KEY_state
609 ? "state"
610 : "my");
748a9306 611
dd2155a4 612 /* allocate a spare slot and store the name in that slot */
93a17b20 613
cc76b5cc 614 off = pad_add_name_pvn(name, len,
48d0d1be
BF
615 (is_our ? padadd_OUR :
616 PL_parser->in_my == KEY_state ? padadd_STATE : 0)
617 | ( flags & SVf_UTF8 ? SVf_UTF8 : 0 ),
12bd6ede 618 PL_parser->in_my_stash,
3edf23ff 619 (is_our
133706a6 620 /* $_ is always in main::, even with our */
ef00320b
FC
621 ? (PL_curstash && !memEQs(name,len,"$_")
622 ? PL_curstash
623 : PL_defstash)
5c284bb0 624 : NULL
cca43f78 625 )
dd2155a4 626 );
a74073ad
DM
627 /* anon sub prototypes contains state vars should always be cloned,
628 * otherwise the state var would be shared between anon subs */
629
630 if (PL_parser->in_my == KEY_state && CvANON(PL_compcv))
631 CvCLONE_on(PL_compcv);
632
dd2155a4 633 return off;
79072805
LW
634}
635
c0b8aebd 636/*
dcccc8ff
KW
637=head1 Optree Manipulation Functions
638
c0b8aebd
FC
639=for apidoc alloccopstash
640
641Available only under threaded builds, this function allocates an entry in
642C<PL_stashpad> for the stash passed to it.
643
644=cut
645*/
646
d4d03940
FC
647#ifdef USE_ITHREADS
648PADOFFSET
1dc74fdb 649Perl_alloccopstash(pTHX_ HV *hv)
d4d03940
FC
650{
651 PADOFFSET off = 0, o = 1;
652 bool found_slot = FALSE;
653
1dc74fdb
FC
654 PERL_ARGS_ASSERT_ALLOCCOPSTASH;
655
656 if (PL_stashpad[PL_stashpadix] == hv) return PL_stashpadix;
d4d03940 657
1dc74fdb
FC
658 for (; o < PL_stashpadmax; ++o) {
659 if (PL_stashpad[o] == hv) return PL_stashpadix = o;
660 if (!PL_stashpad[o] || SvTYPE(PL_stashpad[o]) != SVt_PVHV)
d4d03940
FC
661 found_slot = TRUE, off = o;
662 }
663 if (!found_slot) {
1dc74fdb
FC
664 Renew(PL_stashpad, PL_stashpadmax + 10, HV *);
665 Zero(PL_stashpad + PL_stashpadmax, 10, HV *);
666 off = PL_stashpadmax;
667 PL_stashpadmax += 10;
d4d03940
FC
668 }
669
1dc74fdb 670 PL_stashpad[PL_stashpadix = off] = hv;
d4d03940
FC
671 return off;
672}
673#endif
674
d2c837a0
DM
675/* free the body of an op without examining its contents.
676 * Always use this rather than FreeOp directly */
677
4136a0f7 678static void
d2c837a0
DM
679S_op_destroy(pTHX_ OP *o)
680{
d2c837a0
DM
681 FreeOp(o);
682}
683
79072805
LW
684/* Destructor */
685
6e53b6ca
DD
686/*
687=for apidoc Am|void|op_free|OP *o
688
cc41839b
FC
689Free an op. Only use this when an op is no longer linked to from any
690optree.
6e53b6ca
DD
691
692=cut
693*/
694
79072805 695void
864dbfa3 696Perl_op_free(pTHX_ OP *o)
79072805 697{
27da23d5 698 dVAR;
acb36ea4 699 OPCODE type;
0997db6f
TC
700 SSize_t defer_ix = -1;
701 SSize_t defer_stack_alloc = 0;
702 OP **defer_stack = NULL;
79072805 703
0997db6f 704 do {
79072805 705
0997db6f
TC
706 /* Though ops may be freed twice, freeing the op after its slab is a
707 big no-no. */
708 assert(!o || !o->op_slabbed || OpSLAB(o)->opslab_refcnt != ~(size_t)0);
709 /* During the forced freeing of ops after compilation failure, kidops
710 may be freed before their parents. */
711 if (!o || o->op_type == OP_FREED)
712 continue;
d0c8136d 713
0997db6f 714 type = o->op_type;
d0c8136d 715
0997db6f
TC
716 /* an op should only ever acquire op_private flags that we know about.
717 * If this fails, you may need to fix something in regen/op_private */
718 if (o->op_ppaddr == PL_ppaddr[o->op_type]) {
719 assert(!(o->op_private & ~PL_op_private_valid[type]));
720 }
7934575e 721
0997db6f
TC
722 if (o->op_private & OPpREFCOUNTED) {
723 switch (type) {
724 case OP_LEAVESUB:
725 case OP_LEAVESUBLV:
726 case OP_LEAVEEVAL:
727 case OP_LEAVE:
728 case OP_SCOPE:
729 case OP_LEAVEWRITE:
730 {
731 PADOFFSET refcnt;
732 OP_REFCNT_LOCK;
733 refcnt = OpREFCNT_dec(o);
734 OP_REFCNT_UNLOCK;
735 if (refcnt) {
736 /* Need to find and remove any pattern match ops from the list
737 we maintain for reset(). */
738 find_and_forget_pmops(o);
739 continue;
740 }
741 }
742 break;
743 default:
744 break;
745 }
746 }
f37b8c3f 747
0997db6f
TC
748 /* Call the op_free hook if it has been set. Do it now so that it's called
749 * at the right time for refcounted ops, but still before all of the kids
750 * are freed. */
751 CALL_OPFREEHOOK(o);
752
753 if (o->op_flags & OPf_KIDS) {
754 OP *kid, *nextkid;
755 for (kid = cUNOPo->op_first; kid; kid = nextkid) {
756 nextkid = OP_SIBLING(kid); /* Get before next freeing kid */
757 if (!kid || kid->op_type == OP_FREED)
758 /* During the forced freeing of ops after
759 compilation failure, kidops may be freed before
760 their parents. */
761 continue;
762 if (!(kid->op_flags & OPf_KIDS))
763 /* If it has no kids, just free it now */
764 op_free(kid);
765 else
aa9d1253 766 DEFER_OP(kid);
0997db6f
TC
767 }
768 }
769 if (type == OP_NULL)
770 type = (OPCODE)o->op_targ;
acb36ea4 771
0997db6f
TC
772 if (o->op_slabbed)
773 Slab_to_rw(OpSLAB(o));
fc97af9c 774
0997db6f
TC
775 /* COP* is not cleared by op_clear() so that we may track line
776 * numbers etc even after null() */
777 if (type == OP_NEXTSTATE || type == OP_DBSTATE) {
778 cop_free((COP*)o);
779 }
acb36ea4 780
0997db6f
TC
781 op_clear(o);
782 FreeOp(o);
4d494880 783#ifdef DEBUG_LEAKING_SCALARS
0997db6f
TC
784 if (PL_op == o)
785 PL_op = NULL;
4d494880 786#endif
aa9d1253 787 } while ( (o = POP_DEFERRED_OP()) );
0997db6f
TC
788
789 Safefree(defer_stack);
acb36ea4 790}
79072805 791
93c66552
DM
792void
793Perl_op_clear(pTHX_ OP *o)
acb36ea4 794{
13137afc 795
27da23d5 796 dVAR;
7918f24d
NC
797
798 PERL_ARGS_ASSERT_OP_CLEAR;
799
11343788 800 switch (o->op_type) {
acb36ea4 801 case OP_NULL: /* Was holding old type, if any. */
c67159e1 802 /* FALLTHROUGH */
4d193d44 803 case OP_ENTERTRY:
acb36ea4 804 case OP_ENTEREVAL: /* Was holding hints. */
acb36ea4 805 o->op_targ = 0;
a0d0e21e 806 break;
a6006777 807 default:
ac4c12e7 808 if (!(o->op_flags & OPf_REF)
ef69c8fc 809 || (PL_check[o->op_type] != Perl_ck_ftst))
a6006777 810 break;
924ba076 811 /* FALLTHROUGH */
463ee0b2 812 case OP_GVSV:
79072805 813 case OP_GV:
a6006777 814 case OP_AELEMFAST:
93bad3fd 815 {
f7461760
Z
816 GV *gv = (o->op_type == OP_GV || o->op_type == OP_GVSV)
817#ifdef USE_ITHREADS
818 && PL_curpad
819#endif
820 ? cGVOPo_gv : NULL;
b327b36f
NC
821 /* It's possible during global destruction that the GV is freed
822 before the optree. Whilst the SvREFCNT_inc is happy to bump from
823 0 to 1 on a freed SV, the corresponding SvREFCNT_dec from 1 to 0
824 will trigger an assertion failure, because the entry to sv_clear
825 checks that the scalar is not already freed. A check of for
826 !SvIS_FREED(gv) turns out to be invalid, because during global
827 destruction the reference count can be forced down to zero
828 (with SVf_BREAK set). In which case raising to 1 and then
829 dropping to 0 triggers cleanup before it should happen. I
830 *think* that this might actually be a general, systematic,
831 weakness of the whole idea of SVf_BREAK, in that code *is*
832 allowed to raise and lower references during global destruction,
833 so any *valid* code that happens to do this during global
834 destruction might well trigger premature cleanup. */
835 bool still_valid = gv && SvREFCNT(gv);
836
837 if (still_valid)
838 SvREFCNT_inc_simple_void(gv);
350de78d 839#ifdef USE_ITHREADS
6a077020 840 if (cPADOPo->op_padix > 0) {
6a077020
DM
841 pad_swipe(cPADOPo->op_padix, TRUE);
842 cPADOPo->op_padix = 0;
843 }
350de78d 844#else
6a077020 845 SvREFCNT_dec(cSVOPo->op_sv);
a0714e2c 846 cSVOPo->op_sv = NULL;
350de78d 847#endif
b327b36f 848 if (still_valid) {
f7461760 849 int try_downgrade = SvREFCNT(gv) == 2;
fc2b2dca 850 SvREFCNT_dec_NN(gv);
f7461760
Z
851 if (try_downgrade)
852 gv_try_downgrade(gv);
853 }
6a077020 854 }
79072805 855 break;
a1ae71d2 856 case OP_METHOD_NAMED:
b46e009d 857 SvREFCNT_dec(cMETHOPx(o)->op_u.op_meth_sv);
858 cMETHOPx(o)->op_u.op_meth_sv = NULL;
859#ifdef USE_ITHREADS
860 if (o->op_targ) {
861 pad_swipe(o->op_targ, 1);
862 o->op_targ = 0;
863 }
864#endif
865 break;
79072805 866 case OP_CONST:
996c9baa 867 case OP_HINTSEVAL:
11343788 868 SvREFCNT_dec(cSVOPo->op_sv);
a0714e2c 869 cSVOPo->op_sv = NULL;
3b1c21fa
AB
870#ifdef USE_ITHREADS
871 /** Bug #15654
872 Even if op_clear does a pad_free for the target of the op,
6a077020 873 pad_free doesn't actually remove the sv that exists in the pad;
3b1c21fa
AB
874 instead it lives on. This results in that it could be reused as
875 a target later on when the pad was reallocated.
876 **/
877 if(o->op_targ) {
878 pad_swipe(o->op_targ,1);
879 o->op_targ = 0;
880 }
881#endif
79072805 882 break;
c9df4fda 883 case OP_DUMP:
748a9306
LW
884 case OP_GOTO:
885 case OP_NEXT:
886 case OP_LAST:
887 case OP_REDO:
11343788 888 if (o->op_flags & (OPf_SPECIAL|OPf_STACKED|OPf_KIDS))
748a9306 889 break;
924ba076 890 /* FALLTHROUGH */
a0d0e21e 891 case OP_TRANS:
bb16bae8 892 case OP_TRANSR:
acb36ea4 893 if (o->op_private & (OPpTRANS_FROM_UTF|OPpTRANS_TO_UTF)) {
99a1d0d1 894 assert(o->op_type == OP_TRANS || o->op_type == OP_TRANSR);
043e41b8
DM
895#ifdef USE_ITHREADS
896 if (cPADOPo->op_padix > 0) {
897 pad_swipe(cPADOPo->op_padix, TRUE);
898 cPADOPo->op_padix = 0;
899 }
900#else
a0ed51b3 901 SvREFCNT_dec(cSVOPo->op_sv);
a0714e2c 902 cSVOPo->op_sv = NULL;
043e41b8 903#endif
acb36ea4
GS
904 }
905 else {
ea71c68d 906 PerlMemShared_free(cPVOPo->op_pv);
bd61b366 907 cPVOPo->op_pv = NULL;
acb36ea4 908 }
a0d0e21e
LW
909 break;
910 case OP_SUBST:
20e98b0f 911 op_free(cPMOPo->op_pmreplrootu.op_pmreplroot);
971a9dd3 912 goto clear_pmop;
748a9306 913 case OP_PUSHRE:
971a9dd3 914#ifdef USE_ITHREADS
20e98b0f 915 if (cPMOPo->op_pmreplrootu.op_pmtargetoff) {
20e98b0f 916 pad_swipe(cPMOPo->op_pmreplrootu.op_pmtargetoff, TRUE);
971a9dd3
GS
917 }
918#else
ad64d0ec 919 SvREFCNT_dec(MUTABLE_SV(cPMOPo->op_pmreplrootu.op_pmtargetgv));
971a9dd3 920#endif
924ba076 921 /* FALLTHROUGH */
a0d0e21e 922 case OP_MATCH:
8782bef2 923 case OP_QR:
971a9dd3 924clear_pmop:
867940b8
DM
925 if (!(cPMOPo->op_pmflags & PMf_CODELIST_PRIVATE))
926 op_free(cPMOPo->op_code_list);
68e2671b 927 cPMOPo->op_code_list = NULL;
23083432 928 forget_pmop(cPMOPo);
20e98b0f 929 cPMOPo->op_pmreplrootu.op_pmreplroot = NULL;
9cddf794
NC
930 /* we use the same protection as the "SAFE" version of the PM_ macros
931 * here since sv_clean_all might release some PMOPs
5f8cb046
DM
932 * after PL_regex_padav has been cleared
933 * and the clearing of PL_regex_padav needs to
934 * happen before sv_clean_all
935 */
13137afc
AB
936#ifdef USE_ITHREADS
937 if(PL_regex_pad) { /* We could be in destruction */
402d2eb1 938 const IV offset = (cPMOPo)->op_pmoffset;
9cddf794 939 ReREFCNT_dec(PM_GETRE(cPMOPo));
402d2eb1
NC
940 PL_regex_pad[offset] = &PL_sv_undef;
941 sv_catpvn_nomg(PL_regex_pad[0], (const char *)&offset,
942 sizeof(offset));
13137afc 943 }
9cddf794
NC
944#else
945 ReREFCNT_dec(PM_GETRE(cPMOPo));
946 PM_SETRE(cPMOPo, NULL);
1eb1540c 947#endif
13137afc 948
a0d0e21e 949 break;
79072805
LW
950 }
951
743e66e6 952 if (o->op_targ > 0) {
11343788 953 pad_free(o->op_targ);
743e66e6
GS
954 o->op_targ = 0;
955 }
79072805
LW
956}
957
76e3520e 958STATIC void
3eb57f73
HS
959S_cop_free(pTHX_ COP* cop)
960{
7918f24d
NC
961 PERL_ARGS_ASSERT_COP_FREE;
962
05ec9bb3 963 CopFILE_free(cop);
0453d815 964 if (! specialWARN(cop->cop_warnings))
72dc9ed5 965 PerlMemShared_free(cop->cop_warnings);
20439bc7 966 cophh_free(CopHINTHASH_get(cop));
515abc43
FC
967 if (PL_curcop == cop)
968 PL_curcop = NULL;
3eb57f73
HS
969}
970
c2b1997a 971STATIC void
c4bd3ae5 972S_forget_pmop(pTHX_ PMOP *const o
c4bd3ae5 973 )
c2b1997a
NC
974{
975 HV * const pmstash = PmopSTASH(o);
7918f24d
NC
976
977 PERL_ARGS_ASSERT_FORGET_PMOP;
978
e39a6381 979 if (pmstash && !SvIS_FREED(pmstash) && SvMAGICAL(pmstash)) {
ad64d0ec 980 MAGIC * const mg = mg_find((const SV *)pmstash, PERL_MAGIC_symtab);
c2b1997a
NC
981 if (mg) {
982 PMOP **const array = (PMOP**) mg->mg_ptr;
983 U32 count = mg->mg_len / sizeof(PMOP**);
984 U32 i = count;
985
986 while (i--) {
987 if (array[i] == o) {
988 /* Found it. Move the entry at the end to overwrite it. */
989 array[i] = array[--count];
990 mg->mg_len = count * sizeof(PMOP**);
991 /* Could realloc smaller at this point always, but probably
992 not worth it. Probably worth free()ing if we're the
993 last. */
994 if(!count) {
995 Safefree(mg->mg_ptr);
996 mg->mg_ptr = NULL;
997 }
998 break;
999 }
1000 }
1001 }
1002 }
1cdf7faf
NC
1003 if (PL_curpm == o)
1004 PL_curpm = NULL;
c2b1997a
NC
1005}
1006
bfd0ff22
NC
1007STATIC void
1008S_find_and_forget_pmops(pTHX_ OP *o)
1009{
7918f24d
NC
1010 PERL_ARGS_ASSERT_FIND_AND_FORGET_PMOPS;
1011
bfd0ff22
NC
1012 if (o->op_flags & OPf_KIDS) {
1013 OP *kid = cUNOPo->op_first;
1014 while (kid) {
1015 switch (kid->op_type) {
1016 case OP_SUBST:
1017 case OP_PUSHRE:
1018 case OP_MATCH:
1019 case OP_QR:
23083432 1020 forget_pmop((PMOP*)kid);
bfd0ff22
NC
1021 }
1022 find_and_forget_pmops(kid);
1ed44841 1023 kid = OP_SIBLING(kid);
bfd0ff22
NC
1024 }
1025 }
1026}
1027
6e53b6ca
DD
1028/*
1029=for apidoc Am|void|op_null|OP *o
1030
1031Neutralizes an op when it is no longer needed, but is still linked to from
1032other ops.
1033
1034=cut
1035*/
1036
93c66552
DM
1037void
1038Perl_op_null(pTHX_ OP *o)
8990e307 1039{
27da23d5 1040 dVAR;
7918f24d
NC
1041
1042 PERL_ARGS_ASSERT_OP_NULL;
1043
acb36ea4
GS
1044 if (o->op_type == OP_NULL)
1045 return;
b5bbe64a 1046 op_clear(o);
11343788 1047 o->op_targ = o->op_type;
10884df9 1048 CHANGE_TYPE(o, OP_NULL);
8990e307
LW
1049}
1050
4026c95a
SH
1051void
1052Perl_op_refcnt_lock(pTHX)
1053{
20b7effb 1054#ifdef USE_ITHREADS
27da23d5 1055 dVAR;
20b7effb 1056#endif
96a5add6 1057 PERL_UNUSED_CONTEXT;
4026c95a
SH
1058 OP_REFCNT_LOCK;
1059}
1060
1061void
1062Perl_op_refcnt_unlock(pTHX)
1063{
20b7effb 1064#ifdef USE_ITHREADS
27da23d5 1065 dVAR;
20b7effb 1066#endif
96a5add6 1067 PERL_UNUSED_CONTEXT;
4026c95a
SH
1068 OP_REFCNT_UNLOCK;
1069}
1070
3253bf85
DM
1071
1072/*
1073=for apidoc op_sibling_splice
1074
1075A general function for editing the structure of an existing chain of
7e234f81 1076op_sibling nodes. By analogy with the perl-level splice() function, allows
3253bf85
DM
1077you to delete zero or more sequential nodes, replacing them with zero or
1078more different nodes. Performs the necessary op_first/op_last
29e61fd9 1079housekeeping on the parent node and op_sibling manipulation on the
7e234f81 1080children. The last deleted node will be marked as as the last node by
8ae26bff 1081updating the op_sibling or op_lastsib field as appropriate.
3253bf85
DM
1082
1083Note that op_next is not manipulated, and nodes are not freed; that is the
7e234f81 1084responsibility of the caller. It also won't create a new list op for an
8ae26bff 1085empty list etc; use higher-level functions like op_append_elem() for that.
3253bf85
DM
1086
1087parent is the parent node of the sibling chain.
1088
7e234f81
FC
1089start is the node preceding the first node to be spliced. Node(s)
1090following it will be deleted, and ops will be inserted after it. If it is
3253bf85
DM
1091NULL, the first node onwards is deleted, and nodes are inserted at the
1092beginning.
1093
7e234f81 1094del_count is the number of nodes to delete. If zero, no nodes are deleted.
3253bf85
DM
1095If -1 or greater than or equal to the number of remaining kids, all
1096remaining kids are deleted.
1097
1098insert is the first of a chain of nodes to be inserted in place of the nodes.
1099If NULL, no nodes are inserted.
1100
8ae26bff 1101The head of the chain of deleted ops is returned, or NULL if no ops were
3253bf85
DM
1102deleted.
1103
1104For example:
1105
1106 action before after returns
1107 ------ ----- ----- -------
1108
1109 P P
8ae26bff
DM
1110 splice(P, A, 2, X-Y-Z) | | B-C
1111 A-B-C-D A-X-Y-Z-D
3253bf85
DM
1112
1113 P P
1114 splice(P, NULL, 1, X-Y) | | A
1115 A-B-C-D X-Y-B-C-D
1116
1117 P P
8ae26bff
DM
1118 splice(P, NULL, 3, NULL) | | A-B-C
1119 A-B-C-D D
3253bf85
DM
1120
1121 P P
1122 splice(P, B, 0, X-Y) | | NULL
1123 A-B-C-D A-B-X-Y-C-D
1124
1125=cut
1126*/
1127
1128OP *
8ae26bff 1129Perl_op_sibling_splice(OP *parent, OP *start, int del_count, OP* insert)
3253bf85 1130{
3253bf85
DM
1131 OP *first = start ? OP_SIBLING(start) : cLISTOPx(parent)->op_first;
1132 OP *rest;
1133 OP *last_del = NULL;
1134 OP *last_ins = NULL;
1135
1136 PERL_ARGS_ASSERT_OP_SIBLING_SPLICE;
1137
1138 assert(del_count >= -1);
1139
1140 if (del_count && first) {
1141 last_del = first;
1142 while (--del_count && OP_HAS_SIBLING(last_del))
1143 last_del = OP_SIBLING(last_del);
1144 rest = OP_SIBLING(last_del);
1145 OP_SIBLING_set(last_del, NULL);
29e61fd9 1146 last_del->op_lastsib = 1;
3253bf85
DM
1147 }
1148 else
1149 rest = first;
1150
1151 if (insert) {
1152 last_ins = insert;
1153 while (OP_HAS_SIBLING(last_ins))
1154 last_ins = OP_SIBLING(last_ins);
1155 OP_SIBLING_set(last_ins, rest);
29e61fd9 1156 last_ins->op_lastsib = rest ? 0 : 1;
3253bf85
DM
1157 }
1158 else
1159 insert = rest;
1160
29e61fd9 1161 if (start) {
3253bf85 1162 OP_SIBLING_set(start, insert);
29e61fd9
DM
1163 start->op_lastsib = insert ? 0 : 1;
1164 }
3253bf85
DM
1165 else
1166 cLISTOPx(parent)->op_first = insert;
1167
1168 if (!rest) {
29e61fd9 1169 /* update op_last etc */
3253bf85 1170 U32 type = parent->op_type;
29e61fd9 1171 OP *lastop;
3253bf85
DM
1172
1173 if (type == OP_NULL)
1174 type = parent->op_targ;
1175 type = PL_opargs[type] & OA_CLASS_MASK;
1176
29e61fd9 1177 lastop = last_ins ? last_ins : start ? start : NULL;
3253bf85
DM
1178 if ( type == OA_BINOP
1179 || type == OA_LISTOP
1180 || type == OA_PMOP
1181 || type == OA_LOOP
1182 )
29e61fd9
DM
1183 cLISTOPx(parent)->op_last = lastop;
1184
1185 if (lastop) {
1186 lastop->op_lastsib = 1;
1187#ifdef PERL_OP_PARENT
1188 lastop->op_sibling = parent;
1189#endif
1190 }
3253bf85
DM
1191 }
1192 return last_del ? first : NULL;
1193}
1194
29e61fd9
DM
1195/*
1196=for apidoc op_parent
1197
7e234f81 1198returns the parent OP of o, if it has a parent. Returns NULL otherwise.
29e61fd9
DM
1199(Currently perl must be built with C<-DPERL_OP_PARENT> for this feature to
1200work.
1201
1202=cut
1203*/
1204
1205OP *
8ae26bff 1206Perl_op_parent(OP *o)
29e61fd9
DM
1207{
1208 PERL_ARGS_ASSERT_OP_PARENT;
1209#ifdef PERL_OP_PARENT
1210 while (OP_HAS_SIBLING(o))
1211 o = OP_SIBLING(o);
1212 return o->op_sibling;
1213#else
1214 PERL_UNUSED_ARG(o);
1215 return NULL;
1216#endif
1217}
1218
3253bf85
DM
1219
1220/* replace the sibling following start with a new UNOP, which becomes
1221 * the parent of the original sibling; e.g.
1222 *
1223 * op_sibling_newUNOP(P, A, unop-args...)
1224 *
1225 * P P
1226 * | becomes |
1227 * A-B-C A-U-C
1228 * |
1229 * B
1230 *
1231 * where U is the new UNOP.
1232 *
1233 * parent and start args are the same as for op_sibling_splice();
1234 * type and flags args are as newUNOP().
1235 *
1236 * Returns the new UNOP.
1237 */
1238
1239OP *
1240S_op_sibling_newUNOP(pTHX_ OP *parent, OP *start, I32 type, I32 flags)
1241{
1242 OP *kid, *newop;
1243
1244 kid = op_sibling_splice(parent, start, 1, NULL);
1245 newop = newUNOP(type, flags, kid);
1246 op_sibling_splice(parent, start, 0, newop);
1247 return newop;
1248}
1249
1250
1251/* lowest-level newLOGOP-style function - just allocates and populates
1252 * the struct. Higher-level stuff should be done by S_new_logop() /
1253 * newLOGOP(). This function exists mainly to avoid op_first assignment
1254 * being spread throughout this file.
1255 */
1256
1257LOGOP *
1258S_alloc_LOGOP(pTHX_ I32 type, OP *first, OP* other)
1259{
1e8db68a 1260 dVAR;
3253bf85 1261 LOGOP *logop;
29e61fd9 1262 OP *kid = first;
3253bf85 1263 NewOp(1101, logop, 1, LOGOP);
ddacf109 1264 CHANGE_TYPE(logop, type);
3253bf85
DM
1265 logop->op_first = first;
1266 logop->op_other = other;
1267 logop->op_flags = OPf_KIDS;
29e61fd9
DM
1268 while (kid && OP_HAS_SIBLING(kid))
1269 kid = OP_SIBLING(kid);
1270 if (kid) {
1271 kid->op_lastsib = 1;
1272#ifdef PERL_OP_PARENT
1273 kid->op_sibling = (OP*)logop;
1274#endif
1275 }
3253bf85
DM
1276 return logop;
1277}
1278
1279
79072805
LW
1280/* Contextualizers */
1281
d9088386
Z
1282/*
1283=for apidoc Am|OP *|op_contextualize|OP *o|I32 context
1284
1285Applies a syntactic context to an op tree representing an expression.
1286I<o> is the op tree, and I<context> must be C<G_SCALAR>, C<G_ARRAY>,
1287or C<G_VOID> to specify the context to apply. The modified op tree
1288is returned.
1289
1290=cut
1291*/
1292
1293OP *
1294Perl_op_contextualize(pTHX_ OP *o, I32 context)
1295{
1296 PERL_ARGS_ASSERT_OP_CONTEXTUALIZE;
1297 switch (context) {
1298 case G_SCALAR: return scalar(o);
1299 case G_ARRAY: return list(o);
1300 case G_VOID: return scalarvoid(o);
1301 default:
5637ef5b
NC
1302 Perl_croak(aTHX_ "panic: op_contextualize bad context %ld",
1303 (long) context);
d9088386
Z
1304 }
1305}
1306
5983a79d 1307/*
79072805 1308
5983a79d 1309=for apidoc Am|OP*|op_linklist|OP *o
72d33970 1310This function is the implementation of the L</LINKLIST> macro. It should
5983a79d
BM
1311not be called directly.
1312
1313=cut
1314*/
1315
1316OP *
1317Perl_op_linklist(pTHX_ OP *o)
79072805 1318{
3edf23ff 1319 OP *first;
79072805 1320
5983a79d 1321 PERL_ARGS_ASSERT_OP_LINKLIST;
7918f24d 1322
11343788
MB
1323 if (o->op_next)
1324 return o->op_next;
79072805
LW
1325
1326 /* establish postfix order */
3edf23ff
AL
1327 first = cUNOPo->op_first;
1328 if (first) {
eb578fdb 1329 OP *kid;
3edf23ff
AL
1330 o->op_next = LINKLIST(first);
1331 kid = first;
1332 for (;;) {
29e61fd9
DM
1333 OP *sibl = OP_SIBLING(kid);
1334 if (sibl) {
1335 kid->op_next = LINKLIST(sibl);
1336 kid = sibl;
3edf23ff 1337 } else {
11343788 1338 kid->op_next = o;
3edf23ff
AL
1339 break;
1340 }
79072805
LW
1341 }
1342 }
1343 else
11343788 1344 o->op_next = o;
79072805 1345
11343788 1346 return o->op_next;
79072805
LW
1347}
1348
1f676739 1349static OP *
2dd5337b 1350S_scalarkids(pTHX_ OP *o)
79072805 1351{
11343788 1352 if (o && o->op_flags & OPf_KIDS) {
bfed75c6 1353 OP *kid;
1ed44841 1354 for (kid = cLISTOPo->op_first; kid; kid = OP_SIBLING(kid))
79072805
LW
1355 scalar(kid);
1356 }
11343788 1357 return o;
79072805
LW
1358}
1359
76e3520e 1360STATIC OP *
cea2e8a9 1361S_scalarboolean(pTHX_ OP *o)
8990e307 1362{
7918f24d
NC
1363 PERL_ARGS_ASSERT_SCALARBOOLEAN;
1364
6b7c6d95
FC
1365 if (o->op_type == OP_SASSIGN && cBINOPo->op_first->op_type == OP_CONST
1366 && !(cBINOPo->op_first->op_flags & OPf_SPECIAL)) {
d008e5eb 1367 if (ckWARN(WARN_SYNTAX)) {
6867be6d 1368 const line_t oldline = CopLINE(PL_curcop);
a0d0e21e 1369
2b7cddde
NC
1370 if (PL_parser && PL_parser->copline != NOLINE) {
1371 /* This ensures that warnings are reported at the first line
1372 of the conditional, not the last. */
53a7735b 1373 CopLINE_set(PL_curcop, PL_parser->copline);
2b7cddde 1374 }
9014280d 1375 Perl_warner(aTHX_ packWARN(WARN_SYNTAX), "Found = in conditional, should be ==");
57843af0 1376 CopLINE_set(PL_curcop, oldline);
d008e5eb 1377 }
a0d0e21e 1378 }
11343788 1379 return scalar(o);
8990e307
LW
1380}
1381
0920b7fa
FC
1382static SV *
1383S_op_varname(pTHX_ const OP *o)
1384{
1385 assert(o);
1386 assert(o->op_type == OP_PADAV || o->op_type == OP_RV2AV ||
1387 o->op_type == OP_PADHV || o->op_type == OP_RV2HV);
1388 {
1389 const char funny = o->op_type == OP_PADAV
1390 || o->op_type == OP_RV2AV ? '@' : '%';
1391 if (o->op_type == OP_RV2AV || o->op_type == OP_RV2HV) {
1392 GV *gv;
1393 if (cUNOPo->op_first->op_type != OP_GV
1394 || !(gv = cGVOPx_gv(cUNOPo->op_first)))
1395 return NULL;
1396 return varname(gv, funny, 0, NULL, 0, 1);
1397 }
1398 return
1399 varname(MUTABLE_GV(PL_compcv), funny, o->op_targ, NULL, 0, 1);
1400 }
1401}
1402
429a2555 1403static void
2186f873
FC
1404S_op_pretty(pTHX_ const OP *o, SV **retsv, const char **retpv)
1405{ /* or not so pretty :-) */
2186f873
FC
1406 if (o->op_type == OP_CONST) {
1407 *retsv = cSVOPo_sv;
1408 if (SvPOK(*retsv)) {
1409 SV *sv = *retsv;
1410 *retsv = sv_newmortal();
1411 pv_pretty(*retsv, SvPVX_const(sv), SvCUR(sv), 32, NULL, NULL,
1412 PERL_PV_PRETTY_DUMP |PERL_PV_ESCAPE_UNI_DETECT);
1413 }
1414 else if (!SvOK(*retsv))
1415 *retpv = "undef";
1416 }
1417 else *retpv = "...";
1418}
1419
1420static void
429a2555
FC
1421S_scalar_slice_warning(pTHX_ const OP *o)
1422{
1423 OP *kid;
1424 const char lbrack =
2186f873 1425 o->op_type == OP_HSLICE ? '{' : '[';
429a2555 1426 const char rbrack =
2186f873 1427 o->op_type == OP_HSLICE ? '}' : ']';
429a2555 1428 SV *name;
32e9ec8f 1429 SV *keysv = NULL; /* just to silence compiler warnings */
429a2555
FC
1430 const char *key = NULL;
1431
1432 if (!(o->op_private & OPpSLICEWARNING))
1433 return;
1434 if (PL_parser && PL_parser->error_count)
1435 /* This warning can be nonsensical when there is a syntax error. */
1436 return;
1437
1438 kid = cLISTOPo->op_first;
1ed44841 1439 kid = OP_SIBLING(kid); /* get past pushmark */
429a2555
FC
1440 /* weed out false positives: any ops that can return lists */
1441 switch (kid->op_type) {
1442 case OP_BACKTICK:
1443 case OP_GLOB:
1444 case OP_READLINE:
1445 case OP_MATCH:
1446 case OP_RV2AV:
1447 case OP_EACH:
1448 case OP_VALUES:
1449 case OP_KEYS:
1450 case OP_SPLIT:
1451 case OP_LIST:
1452 case OP_SORT:
1453 case OP_REVERSE:
1454 case OP_ENTERSUB:
1455 case OP_CALLER:
1456 case OP_LSTAT:
1457 case OP_STAT:
1458 case OP_READDIR:
1459 case OP_SYSTEM:
1460 case OP_TMS:
1461 case OP_LOCALTIME:
1462 case OP_GMTIME:
1463 case OP_ENTEREVAL:
1464 case OP_REACH:
1465 case OP_RKEYS:
1466 case OP_RVALUES:
1467 return;
1468 }
7d3c8a68
SM
1469
1470 /* Don't warn if we have a nulled list either. */
1471 if (kid->op_type == OP_NULL && kid->op_targ == OP_LIST)
1472 return;
1473
1ed44841
DM
1474 assert(OP_SIBLING(kid));
1475 name = S_op_varname(aTHX_ OP_SIBLING(kid));
429a2555
FC
1476 if (!name) /* XS module fiddling with the op tree */
1477 return;
2186f873 1478 S_op_pretty(aTHX_ kid, &keysv, &key);
429a2555
FC
1479 assert(SvPOK(name));
1480 sv_chop(name,SvPVX(name)+1);
1481 if (key)
2186f873 1482 /* diag_listed_as: Scalar value @%s[%s] better written as $%s[%s] */
429a2555 1483 Perl_warner(aTHX_ packWARN(WARN_SYNTAX),
2186f873 1484 "Scalar value @%"SVf"%c%s%c better written as $%"SVf
429a2555 1485 "%c%s%c",
2186f873 1486 SVfARG(name), lbrack, key, rbrack, SVfARG(name),
429a2555
FC
1487 lbrack, key, rbrack);
1488 else
2186f873 1489 /* diag_listed_as: Scalar value @%s[%s] better written as $%s[%s] */
429a2555 1490 Perl_warner(aTHX_ packWARN(WARN_SYNTAX),
2186f873 1491 "Scalar value @%"SVf"%c%"SVf"%c better written as $%"
429a2555 1492 SVf"%c%"SVf"%c",
c1f6cd39
BF
1493 SVfARG(name), lbrack, SVfARG(keysv), rbrack,
1494 SVfARG(name), lbrack, SVfARG(keysv), rbrack);
429a2555
FC
1495}
1496
8990e307 1497OP *
864dbfa3 1498Perl_scalar(pTHX_ OP *o)
79072805
LW
1499{
1500 OP *kid;
1501
a0d0e21e 1502 /* assumes no premature commitment */
13765c85
DM
1503 if (!o || (PL_parser && PL_parser->error_count)
1504 || (o->op_flags & OPf_WANT)
5dc0d613 1505 || o->op_type == OP_RETURN)
7e363e51 1506 {
11343788 1507 return o;
7e363e51 1508 }
79072805 1509
5dc0d613 1510 o->op_flags = (o->op_flags & ~OPf_WANT) | OPf_WANT_SCALAR;
79072805 1511
11343788 1512 switch (o->op_type) {
79072805 1513 case OP_REPEAT:
11343788 1514 scalar(cBINOPo->op_first);
82e4f303
FC
1515 if (o->op_private & OPpREPEAT_DOLIST) {
1516 kid = cLISTOPx(cUNOPo->op_first)->op_first;
1517 assert(kid->op_type == OP_PUSHMARK);
1518 if (OP_HAS_SIBLING(kid) && !OP_HAS_SIBLING(OP_SIBLING(kid))) {
1519 op_null(cLISTOPx(cUNOPo->op_first)->op_first);
1520 o->op_private &=~ OPpREPEAT_DOLIST;
1521 }
1522 }
8990e307 1523 break;
79072805
LW
1524 case OP_OR:
1525 case OP_AND:
1526 case OP_COND_EXPR:
1ed44841 1527 for (kid = OP_SIBLING(cUNOPo->op_first); kid; kid = OP_SIBLING(kid))
8990e307 1528 scalar(kid);
79072805 1529 break;
924ba076 1530 /* FALLTHROUGH */
a6d8037e 1531 case OP_SPLIT:
79072805 1532 case OP_MATCH:
8782bef2 1533 case OP_QR:
79072805
LW
1534 case OP_SUBST:
1535 case OP_NULL:
8990e307 1536 default:
11343788 1537 if (o->op_flags & OPf_KIDS) {
1ed44841 1538 for (kid = cUNOPo->op_first; kid; kid = OP_SIBLING(kid))
8990e307
LW
1539 scalar(kid);
1540 }
79072805
LW
1541 break;
1542 case OP_LEAVE:
1543 case OP_LEAVETRY:
5dc0d613 1544 kid = cLISTOPo->op_first;
54310121 1545 scalar(kid);
1ed44841 1546 kid = OP_SIBLING(kid);
25b991bf
VP
1547 do_kids:
1548 while (kid) {
1ed44841 1549 OP *sib = OP_SIBLING(kid);
c08f093b
VP
1550 if (sib && kid->op_type != OP_LEAVEWHEN)
1551 scalarvoid(kid);
1552 else
54310121 1553 scalar(kid);
25b991bf 1554 kid = sib;
54310121 1555 }
11206fdd 1556 PL_curcop = &PL_compiling;
54310121 1557 break;
748a9306 1558 case OP_SCOPE:
79072805 1559 case OP_LINESEQ:
8990e307 1560 case OP_LIST:
25b991bf
VP
1561 kid = cLISTOPo->op_first;
1562 goto do_kids;
a801c63c 1563 case OP_SORT:
a2a5de95 1564 Perl_ck_warner(aTHX_ packWARN(WARN_VOID), "Useless use of sort in scalar context");
553e7bb0 1565 break;
95a31aad
FC
1566 case OP_KVHSLICE:
1567 case OP_KVASLICE:
2186f873
FC
1568 {
1569 /* Warn about scalar context */
1570 const char lbrack = o->op_type == OP_KVHSLICE ? '{' : '[';
1571 const char rbrack = o->op_type == OP_KVHSLICE ? '}' : ']';
1572 SV *name;
1573 SV *keysv;
1574 const char *key = NULL;
1575
1576 /* This warning can be nonsensical when there is a syntax error. */
1577 if (PL_parser && PL_parser->error_count)
1578 break;
1579
1580 if (!ckWARN(WARN_SYNTAX)) break;
1581
1582 kid = cLISTOPo->op_first;
1ed44841
DM
1583 kid = OP_SIBLING(kid); /* get past pushmark */
1584 assert(OP_SIBLING(kid));
1585 name = S_op_varname(aTHX_ OP_SIBLING(kid));
2186f873
FC
1586 if (!name) /* XS module fiddling with the op tree */
1587 break;
1588 S_op_pretty(aTHX_ kid, &keysv, &key);
1589 assert(SvPOK(name));
1590 sv_chop(name,SvPVX(name)+1);
1591 if (key)
1592 /* diag_listed_as: %%s[%s] in scalar context better written as $%s[%s] */
1593 Perl_warner(aTHX_ packWARN(WARN_SYNTAX),
1594 "%%%"SVf"%c%s%c in scalar context better written "
1595 "as $%"SVf"%c%s%c",
1596 SVfARG(name), lbrack, key, rbrack, SVfARG(name),
1597 lbrack, key, rbrack);
1598 else
1599 /* diag_listed_as: %%s[%s] in scalar context better written as $%s[%s] */
1600 Perl_warner(aTHX_ packWARN(WARN_SYNTAX),
1601 "%%%"SVf"%c%"SVf"%c in scalar context better "
1602 "written as $%"SVf"%c%"SVf"%c",
c1f6cd39
BF
1603 SVfARG(name), lbrack, SVfARG(keysv), rbrack,
1604 SVfARG(name), lbrack, SVfARG(keysv), rbrack);
2186f873 1605 }
79072805 1606 }
11343788 1607 return o;
79072805
LW
1608}
1609
1610OP *
aa9d1253 1611Perl_scalarvoid(pTHX_ OP *arg)
79072805 1612{
27da23d5 1613 dVAR;
79072805 1614 OP *kid;
8990e307 1615 SV* sv;
2ebea0a1 1616 U8 want;
aa9d1253
TC
1617 SSize_t defer_stack_alloc = 0;
1618 SSize_t defer_ix = -1;
1619 OP **defer_stack = NULL;
1620 OP *o = arg;
2ebea0a1 1621
7918f24d
NC
1622 PERL_ARGS_ASSERT_SCALARVOID;
1623
aa9d1253
TC
1624 do {
1625 SV *useless_sv = NULL;
1626 const char* useless = NULL;
1627
acb36ea4 1628 if (o->op_type == OP_NEXTSTATE
acb36ea4
GS
1629 || o->op_type == OP_DBSTATE
1630 || (o->op_type == OP_NULL && (o->op_targ == OP_NEXTSTATE
acb36ea4 1631 || o->op_targ == OP_DBSTATE)))
2ebea0a1 1632 PL_curcop = (COP*)o; /* for warning below */
79072805 1633
54310121 1634 /* assumes no premature commitment */
2ebea0a1 1635 want = o->op_flags & OPf_WANT;
13765c85
DM
1636 if ((want && want != OPf_WANT_SCALAR)
1637 || (PL_parser && PL_parser->error_count)
25b991bf 1638 || o->op_type == OP_RETURN || o->op_type == OP_REQUIRE || o->op_type == OP_LEAVEWHEN)
7e363e51 1639 {
aa9d1253 1640 continue;
7e363e51 1641 }
79072805 1642
b162f9ea 1643 if ((o->op_private & OPpTARGET_MY)
7e363e51
GS
1644 && (PL_opargs[o->op_type] & OA_TARGLEX))/* OPp share the meaning */
1645 {
aa9d1253
TC
1646 scalar(o); /* As if inside SASSIGN */
1647 continue;
7e363e51 1648 }
1c846c1f 1649
5dc0d613 1650 o->op_flags = (o->op_flags & ~OPf_WANT) | OPf_WANT_VOID;
79072805 1651
11343788 1652 switch (o->op_type) {
79072805 1653 default:
22c35a8c 1654 if (!(PL_opargs[o->op_type] & OA_FOLDCONST))
8990e307 1655 break;
924ba076 1656 /* FALLTHROUGH */
36477c24 1657 case OP_REPEAT:
11343788 1658 if (o->op_flags & OPf_STACKED)
8990e307 1659 break;
5d82c453
GA
1660 goto func_ops;
1661 case OP_SUBSTR:
1662 if (o->op_private == 4)
1663 break;
924ba076 1664 /* FALLTHROUGH */
8990e307
LW
1665 case OP_GVSV:
1666 case OP_WANTARRAY:
1667 case OP_GV:
74295f0b 1668 case OP_SMARTMATCH:
8990e307
LW
1669 case OP_PADSV:
1670 case OP_PADAV:
1671 case OP_PADHV:
1672 case OP_PADANY:
1673 case OP_AV2ARYLEN:
8990e307 1674 case OP_REF:
a0d0e21e
LW
1675 case OP_REFGEN:
1676 case OP_SREFGEN:
8990e307
LW
1677 case OP_DEFINED:
1678 case OP_HEX:
1679 case OP_OCT:
1680 case OP_LENGTH:
8990e307
LW
1681 case OP_VEC:
1682 case OP_INDEX:
1683 case OP_RINDEX:
1684 case OP_SPRINTF:
1685 case OP_AELEM:
1686 case OP_AELEMFAST:
93bad3fd 1687 case OP_AELEMFAST_LEX:
8990e307 1688 case OP_ASLICE:
6dd3e0f2 1689 case OP_KVASLICE:
8990e307
LW
1690 case OP_HELEM:
1691 case OP_HSLICE:
5cae3edb 1692 case OP_KVHSLICE:
8990e307
LW
1693 case OP_UNPACK:
1694 case OP_PACK:
8990e307
LW
1695 case OP_JOIN:
1696 case OP_LSLICE:
1697 case OP_ANONLIST:
1698 case OP_ANONHASH:
1699 case OP_SORT:
1700 case OP_REVERSE:
1701 case OP_RANGE:
1702 case OP_FLIP:
1703 case OP_FLOP:
1704 case OP_CALLER:
1705 case OP_FILENO:
1706 case OP_EOF:
1707 case OP_TELL:
1708 case OP_GETSOCKNAME:
1709 case OP_GETPEERNAME:
1710 case OP_READLINK:
1711 case OP_TELLDIR:
1712 case OP_GETPPID:
1713 case OP_GETPGRP:
1714 case OP_GETPRIORITY:
1715 case OP_TIME:
1716 case OP_TMS:
1717 case OP_LOCALTIME:
1718 case OP_GMTIME:
1719 case OP_GHBYNAME:
1720 case OP_GHBYADDR:
1721 case OP_GHOSTENT:
1722 case OP_GNBYNAME:
1723 case OP_GNBYADDR:
1724 case OP_GNETENT:
1725 case OP_GPBYNAME:
1726 case OP_GPBYNUMBER:
1727 case OP_GPROTOENT:
1728 case OP_GSBYNAME:
1729 case OP_GSBYPORT:
1730 case OP_GSERVENT:
1731 case OP_GPWNAM:
1732 case OP_GPWUID:
1733 case OP_GGRNAM:
1734 case OP_GGRGID:
1735 case OP_GETLOGIN:
78e1b766 1736 case OP_PROTOTYPE:
703227f5 1737 case OP_RUNCV:
5d82c453 1738 func_ops:
64aac5a9 1739 if (!(o->op_private & (OPpLVAL_INTRO|OPpOUR_INTRO)))
74295f0b 1740 /* Otherwise it's "Useless use of grep iterator" */
f5df4782 1741 useless = OP_DESC(o);
75068674
RGS
1742 break;
1743
1744 case OP_SPLIT:
1745 kid = cLISTOPo->op_first;
1746 if (kid && kid->op_type == OP_PUSHRE
fd017c00 1747 && !kid->op_targ
ef7999f1 1748 && !(o->op_flags & OPf_STACKED)
75068674 1749#ifdef USE_ITHREADS
0937eeac 1750 && !((PMOP*)kid)->op_pmreplrootu.op_pmtargetoff
75068674 1751#else
0937eeac 1752 && !((PMOP*)kid)->op_pmreplrootu.op_pmtargetgv
75068674 1753#endif
0937eeac 1754 )
75068674 1755 useless = OP_DESC(o);
8990e307
LW
1756 break;
1757
9f82cd5f
YST
1758 case OP_NOT:
1759 kid = cUNOPo->op_first;
1760 if (kid->op_type != OP_MATCH && kid->op_type != OP_SUBST &&
bb16bae8 1761 kid->op_type != OP_TRANS && kid->op_type != OP_TRANSR) {
9f82cd5f
YST
1762 goto func_ops;
1763 }
1764 useless = "negative pattern binding (!~)";
1765 break;
1766
4f4d7508
DC
1767 case OP_SUBST:
1768 if (cPMOPo->op_pmflags & PMf_NONDESTRUCT)
8db9069c 1769 useless = "non-destructive substitution (s///r)";
4f4d7508
DC
1770 break;
1771
bb16bae8
FC
1772 case OP_TRANSR:
1773 useless = "non-destructive transliteration (tr///r)";
1774 break;
1775
8990e307
LW
1776 case OP_RV2GV:
1777 case OP_RV2SV:
1778 case OP_RV2AV:
1779 case OP_RV2HV:
192587c2 1780 if (!(o->op_private & (OPpLVAL_INTRO|OPpOUR_INTRO)) &&
1ed44841 1781 (!OP_HAS_SIBLING(o) || OP_SIBLING(o)->op_type != OP_READLINE))
8990e307
LW
1782 useless = "a variable";
1783 break;
79072805
LW
1784
1785 case OP_CONST:
7766f137 1786 sv = cSVOPo_sv;
7a52d87a
GS
1787 if (cSVOPo->op_private & OPpCONST_STRICT)
1788 no_bareword_allowed(o);
1789 else {
d008e5eb 1790 if (ckWARN(WARN_VOID)) {
365c7d0c 1791 NV nv;
e7fec78e 1792 /* don't warn on optimised away booleans, eg
b5a930ec 1793 * use constant Foo, 5; Foo || print; */
e7fec78e 1794 if (cSVOPo->op_private & OPpCONST_SHORTCIRCUIT)
d4c19fe8 1795 useless = NULL;
960b4253
MG
1796 /* the constants 0 and 1 are permitted as they are
1797 conventionally used as dummies in constructs like
1798 1 while some_condition_with_side_effects; */
365c7d0c 1799 else if (SvNIOK(sv) && ((nv = SvNV(sv)) == 0.0 || nv == 1.0))
d4c19fe8 1800 useless = NULL;
d008e5eb 1801 else if (SvPOK(sv)) {
1e3f3188
KW
1802 SV * const dsv = newSVpvs("");
1803 useless_sv
1804 = Perl_newSVpvf(aTHX_
1805 "a constant (%s)",
1806 pv_pretty(dsv, SvPVX_const(sv),
1807 SvCUR(sv), 32, NULL, NULL,
1808 PERL_PV_PRETTY_DUMP
1809 | PERL_PV_ESCAPE_NOCLEAR
1810 | PERL_PV_ESCAPE_UNI_DETECT));
1811 SvREFCNT_dec_NN(dsv);
d008e5eb 1812 }
919f76a3 1813 else if (SvOK(sv)) {
c1f6cd39 1814 useless_sv = Perl_newSVpvf(aTHX_ "a constant (%"SVf")", SVfARG(sv));
919f76a3
RGS
1815 }
1816 else
1817 useless = "a constant (undef)";
8990e307
LW
1818 }
1819 }
93c66552 1820 op_null(o); /* don't execute or even remember it */
79072805
LW
1821 break;
1822
1823 case OP_POSTINC:
10884df9 1824 CHANGE_TYPE(o, OP_PREINC); /* pre-increment is faster */
79072805
LW
1825 break;
1826
1827 case OP_POSTDEC:
10884df9 1828 CHANGE_TYPE(o, OP_PREDEC); /* pre-decrement is faster */
79072805
LW
1829 break;
1830
679d6c4e 1831 case OP_I_POSTINC:
10884df9 1832 CHANGE_TYPE(o, OP_I_PREINC); /* pre-increment is faster */
679d6c4e
HS
1833 break;
1834
1835 case OP_I_POSTDEC:
10884df9 1836 CHANGE_TYPE(o, OP_I_PREDEC); /* pre-decrement is faster */
679d6c4e
HS
1837 break;
1838
f2f8fd84
GG
1839 case OP_SASSIGN: {
1840 OP *rv2gv;
1841 UNOP *refgen, *rv2cv;
1842 LISTOP *exlist;
1843
1844 if ((o->op_private & ~OPpASSIGN_BACKWARDS) != 2)
1845 break;
1846
1847 rv2gv = ((BINOP *)o)->op_last;
1848 if (!rv2gv || rv2gv->op_type != OP_RV2GV)
1849 break;
1850
1851 refgen = (UNOP *)((BINOP *)o)->op_first;
1852
18690b0b
FC
1853 if (!refgen || (refgen->op_type != OP_REFGEN
1854 && refgen->op_type != OP_SREFGEN))
f2f8fd84
GG
1855 break;
1856
1857 exlist = (LISTOP *)refgen->op_first;
1858 if (!exlist || exlist->op_type != OP_NULL
1859 || exlist->op_targ != OP_LIST)
1860 break;
1861
18690b0b
FC
1862 if (exlist->op_first->op_type != OP_PUSHMARK
1863 && exlist->op_first != exlist->op_last)
f2f8fd84
GG
1864 break;
1865
1866 rv2cv = (UNOP*)exlist->op_last;
1867
1868 if (rv2cv->op_type != OP_RV2CV)
1869 break;
1870
1871 assert ((rv2gv->op_private & OPpDONT_INIT_GV) == 0);
1872 assert ((o->op_private & OPpASSIGN_CV_TO_GV) == 0);
1873 assert ((rv2cv->op_private & OPpMAY_RETURN_CONSTANT) == 0);
1874
1875 o->op_private |= OPpASSIGN_CV_TO_GV;
1876 rv2gv->op_private |= OPpDONT_INIT_GV;
1877 rv2cv->op_private |= OPpMAY_RETURN_CONSTANT;
1878
1879 break;
1880 }
1881
540dd770
GG
1882 case OP_AASSIGN: {
1883 inplace_aassign(o);
1884 break;
1885 }
1886
79072805
LW
1887 case OP_OR:
1888 case OP_AND:
edbe35ea
VP
1889 kid = cLOGOPo->op_first;
1890 if (kid->op_type == OP_NOT
b5bbe64a 1891 && (kid->op_flags & OPf_KIDS)) {
edbe35ea 1892 if (o->op_type == OP_AND) {
10884df9 1893 CHANGE_TYPE(o, OP_OR);
edbe35ea 1894 } else {
10884df9 1895 CHANGE_TYPE(o, OP_AND);
edbe35ea
VP
1896 }
1897 op_null(kid);
1898 }
c67159e1 1899 /* FALLTHROUGH */
edbe35ea 1900
c963b151 1901 case OP_DOR:
79072805 1902 case OP_COND_EXPR:
0d863452
RH
1903 case OP_ENTERGIVEN:
1904 case OP_ENTERWHEN:
1ed44841 1905 for (kid = OP_SIBLING(cUNOPo->op_first); kid; kid = OP_SIBLING(kid))
aa9d1253
TC
1906 if (!(kid->op_flags & OPf_KIDS))
1907 scalarvoid(kid);
1908 else
1909 DEFER_OP(kid);
79072805 1910 break;
5aabfad6 1911
a0d0e21e 1912 case OP_NULL:
11343788 1913 if (o->op_flags & OPf_STACKED)
a0d0e21e 1914 break;
924ba076 1915 /* FALLTHROUGH */
2ebea0a1
GS
1916 case OP_NEXTSTATE:
1917 case OP_DBSTATE:
79072805
LW
1918 case OP_ENTERTRY:
1919 case OP_ENTER:
11343788 1920 if (!(o->op_flags & OPf_KIDS))
79072805 1921 break;
924ba076 1922 /* FALLTHROUGH */
463ee0b2 1923 case OP_SCOPE:
79072805
LW
1924 case OP_LEAVE:
1925 case OP_LEAVETRY:
a0d0e21e 1926 case OP_LEAVELOOP:
79072805 1927 case OP_LINESEQ:
0d863452
RH
1928 case OP_LEAVEGIVEN:
1929 case OP_LEAVEWHEN:
6aa68307 1930 kids:
1ed44841 1931 for (kid = cLISTOPo->op_first; kid; kid = OP_SIBLING(kid))
aa9d1253
TC
1932 if (!(kid->op_flags & OPf_KIDS))
1933 scalarvoid(kid);
1934 else
1935 DEFER_OP(kid);
79072805 1936 break;
6aa68307
FC
1937 case OP_LIST:
1938 /* If the first kid after pushmark is something that the padrange
1939 optimisation would reject, then null the list and the pushmark.
1940 */
1941 if ((kid = cLISTOPo->op_first)->op_type == OP_PUSHMARK
1942 && ( !(kid = OP_SIBLING(kid))
1943 || ( kid->op_type != OP_PADSV
1944 && kid->op_type != OP_PADAV
1945 && kid->op_type != OP_PADHV)
8c225ab7
FC
1946 || kid->op_private & ~OPpLVAL_INTRO
1947 || !(kid = OP_SIBLING(kid))
1948 || ( kid->op_type != OP_PADSV
1949 && kid->op_type != OP_PADAV
1950 && kid->op_type != OP_PADHV)
6aa68307
FC
1951 || kid->op_private & ~OPpLVAL_INTRO)
1952 ) {
1953 op_null(cUNOPo->op_first); /* NULL the pushmark */
1954 op_null(o); /* NULL the list */
1955 }
1956 goto kids;
c90c0ff4 1957 case OP_ENTEREVAL:
5196be3e 1958 scalarkids(o);
c90c0ff4 1959 break;
d6483035 1960 case OP_SCALAR:
aa9d1253
TC
1961 scalar(o);
1962 break;
79072805 1963 }
095b19d1
NC
1964
1965 if (useless_sv) {
1966 /* mortalise it, in case warnings are fatal. */
1967 Perl_ck_warner(aTHX_ packWARN(WARN_VOID),
1968 "Useless use of %"SVf" in void context",
c1f6cd39 1969 SVfARG(sv_2mortal(useless_sv)));
095b19d1
NC
1970 }
1971 else if (useless) {
1972 Perl_ck_warner(aTHX_ packWARN(WARN_VOID),
1973 "Useless use of %s in void context",
1974 useless);
1975 }
aa9d1253
TC
1976 } while ( (o = POP_DEFERRED_OP()) );
1977
1978 Safefree(defer_stack);
1979
1980 return arg;
79072805
LW
1981}
1982
1f676739 1983static OP *
412da003 1984S_listkids(pTHX_ OP *o)
79072805 1985{
11343788 1986 if (o && o->op_flags & OPf_KIDS) {
6867be6d 1987 OP *kid;
1ed44841 1988 for (kid = cLISTOPo->op_first; kid; kid = OP_SIBLING(kid))
79072805
LW
1989 list(kid);
1990 }
11343788 1991 return o;
79072805
LW
1992}
1993
1994OP *
864dbfa3 1995Perl_list(pTHX_ OP *o)
79072805
LW
1996{
1997 OP *kid;
1998
a0d0e21e 1999 /* assumes no premature commitment */
13765c85
DM
2000 if (!o || (o->op_flags & OPf_WANT)
2001 || (PL_parser && PL_parser->error_count)
5dc0d613 2002 || o->op_type == OP_RETURN)
7e363e51 2003 {
11343788 2004 return o;
7e363e51 2005 }
79072805 2006
b162f9ea 2007 if ((o->op_private & OPpTARGET_MY)
7e363e51
GS
2008 && (PL_opargs[o->op_type] & OA_TARGLEX))/* OPp share the meaning */
2009 {
b162f9ea 2010 return o; /* As if inside SASSIGN */
7e363e51 2011 }
1c846c1f 2012
5dc0d613 2013 o->op_flags = (o->op_flags & ~OPf_WANT) | OPf_WANT_LIST;
79072805 2014
11343788 2015 switch (o->op_type) {
79072805 2016 case OP_FLOP:
11343788 2017 list(cBINOPo->op_first);
79072805 2018 break;
c57eecc5
FC
2019 case OP_REPEAT:
2020 if (o->op_private & OPpREPEAT_DOLIST
2021 && !(o->op_flags & OPf_STACKED))
2022 {
2023 list(cBINOPo->op_first);
2024 kid = cBINOPo->op_last;
2025 if (kid->op_type == OP_CONST && SvIOK(kSVOP_sv)
2026 && SvIVX(kSVOP_sv) == 1)
2027 {
2028 op_null(o); /* repeat */
2029 op_null(cUNOPx(cBINOPo->op_first)->op_first);/* pushmark */
2030 /* const (rhs): */
2031 op_free(op_sibling_splice(o, cBINOPo->op_first, 1, NULL));
2032 }
2033 }
2034 break;
79072805
LW
2035 case OP_OR:
2036 case OP_AND:
2037 case OP_COND_EXPR:
1ed44841 2038 for (kid = OP_SIBLING(cUNOPo->op_first); kid; kid = OP_SIBLING(kid))
79072805
LW
2039 list(kid);
2040 break;
2041 default:
2042 case OP_MATCH:
8782bef2 2043 case OP_QR:
79072805
LW
2044 case OP_SUBST:
2045 case OP_NULL:
11343788 2046 if (!(o->op_flags & OPf_KIDS))
79072805 2047 break;
11343788
MB
2048 if (!o->op_next && cUNOPo->op_first->op_type == OP_FLOP) {
2049 list(cBINOPo->op_first);
2050 return gen_constant_list(o);
79072805 2051 }
6aa68307
FC
2052 listkids(o);
2053 break;
79072805 2054 case OP_LIST:
11343788 2055 listkids(o);
6aa68307
FC
2056 if (cLISTOPo->op_first->op_type == OP_PUSHMARK) {
2057 op_null(cUNOPo->op_first); /* NULL the pushmark */
2058 op_null(o); /* NULL the list */
2059 }
79072805
LW
2060 break;
2061 case OP_LEAVE:
2062 case OP_LEAVETRY:
5dc0d613 2063 kid = cLISTOPo->op_first;
54310121 2064 list(kid);
1ed44841 2065 kid = OP_SIBLING(kid);
25b991bf
VP
2066 do_kids:
2067 while (kid) {
1ed44841 2068 OP *sib = OP_SIBLING(kid);
c08f093b
VP
2069 if (sib && kid->op_type != OP_LEAVEWHEN)
2070 scalarvoid(kid);
2071 else
54310121 2072 list(kid);
25b991bf 2073 kid = sib;
54310121 2074 }
11206fdd 2075 PL_curcop = &PL_compiling;
54310121 2076 break;
748a9306 2077 case OP_SCOPE:
79072805 2078 case OP_LINESEQ:
25b991bf
VP
2079 kid = cLISTOPo->op_first;
2080 goto do_kids;
79072805 2081 }
11343788 2082 return o;
79072805
LW
2083}
2084
1f676739 2085static OP *
2dd5337b 2086S_scalarseq(pTHX_ OP *o)
79072805 2087{
11343788 2088 if (o) {
1496a290
AL
2089 const OPCODE type = o->op_type;
2090
2091 if (type == OP_LINESEQ || type == OP_SCOPE ||
2092 type == OP_LEAVE || type == OP_LEAVETRY)
463ee0b2 2093 {
6867be6d 2094 OP *kid;
1ed44841
DM
2095 for (kid = cLISTOPo->op_first; kid; kid = OP_SIBLING(kid)) {
2096 if (OP_HAS_SIBLING(kid)) {
463ee0b2 2097 scalarvoid(kid);
ed6116ce 2098 }
463ee0b2 2099 }
3280af22 2100 PL_curcop = &PL_compiling;
79072805 2101 }
11343788 2102 o->op_flags &= ~OPf_PARENS;
3280af22 2103 if (PL_hints & HINT_BLOCK_SCOPE)
11343788 2104 o->op_flags |= OPf_PARENS;
79072805 2105 }
8990e307 2106 else
11343788
MB
2107 o = newOP(OP_STUB, 0);
2108 return o;
79072805
LW
2109}
2110
76e3520e 2111STATIC OP *
cea2e8a9 2112S_modkids(pTHX_ OP *o, I32 type)
79072805 2113{
11343788 2114 if (o && o->op_flags & OPf_KIDS) {
6867be6d 2115 OP *kid;
1ed44841 2116 for (kid = cLISTOPo->op_first; kid; kid = OP_SIBLING(kid))
3ad73efd 2117 op_lvalue(kid, type);
79072805 2118 }
11343788 2119 return o;
79072805
LW
2120}
2121
3ad73efd 2122/*
d164302a
GG
2123=for apidoc finalize_optree
2124
72d33970
FC
2125This function finalizes the optree. Should be called directly after
2126the complete optree is built. It does some additional
d164302a
GG
2127checking which can't be done in the normal ck_xxx functions and makes
2128the tree thread-safe.
2129
2130=cut
2131*/
2132void
2133Perl_finalize_optree(pTHX_ OP* o)
2134{
2135 PERL_ARGS_ASSERT_FINALIZE_OPTREE;
2136
2137 ENTER;
2138 SAVEVPTR(PL_curcop);
2139
2140 finalize_op(o);
2141
2142 LEAVE;
2143}
2144
b46e009d 2145#ifdef USE_ITHREADS
2146/* Relocate sv to the pad for thread safety.
2147 * Despite being a "constant", the SV is written to,
2148 * for reference counts, sv_upgrade() etc. */
2149PERL_STATIC_INLINE void
2150S_op_relocate_sv(pTHX_ SV** svp, PADOFFSET* targp)
2151{
2152 PADOFFSET ix;
2153 PERL_ARGS_ASSERT_OP_RELOCATE_SV;
2154 if (!*svp) return;
2155 ix = pad_alloc(OP_CONST, SVf_READONLY);
2156 SvREFCNT_dec(PAD_SVl(ix));
2157 PAD_SETSV(ix, *svp);
2158 /* XXX I don't know how this isn't readonly already. */
2159 if (!SvIsCOW(PAD_SVl(ix))) SvREADONLY_on(PAD_SVl(ix));
2160 *svp = NULL;
2161 *targp = ix;
2162}
2163#endif
2164
2165
60dde6b2 2166STATIC void
d164302a
GG
2167S_finalize_op(pTHX_ OP* o)
2168{
2169 PERL_ARGS_ASSERT_FINALIZE_OP;
2170
d164302a
GG
2171
2172 switch (o->op_type) {
2173 case OP_NEXTSTATE:
2174 case OP_DBSTATE:
2175 PL_curcop = ((COP*)o); /* for warnings */
2176 break;
2177 case OP_EXEC:
1ed44841
DM
2178 if (OP_HAS_SIBLING(o)) {
2179 OP *sib = OP_SIBLING(o);
2180 if (( sib->op_type == OP_NEXTSTATE || sib->op_type == OP_DBSTATE)
2181 && ckWARN(WARN_EXEC)
2182 && OP_HAS_SIBLING(sib))
2183 {
2184 const OPCODE type = OP_SIBLING(sib)->op_type;
d164302a
GG
2185 if (type != OP_EXIT && type != OP_WARN && type != OP_DIE) {
2186 const line_t oldline = CopLINE(PL_curcop);
1ed44841 2187 CopLINE_set(PL_curcop, CopLINE((COP*)sib));
d164302a
GG
2188 Perl_warner(aTHX_ packWARN(WARN_EXEC),
2189 "Statement unlikely to be reached");
2190 Perl_warner(aTHX_ packWARN(WARN_EXEC),
2191 "\t(Maybe you meant system() when you said exec()?)\n");
2192 CopLINE_set(PL_curcop, oldline);
2193 }
d164302a 2194 }
1ed44841 2195 }
d164302a
GG
2196 break;
2197
2198 case OP_GV:
2199 if ((o->op_private & OPpEARLY_CV) && ckWARN(WARN_PROTOTYPE)) {
2200 GV * const gv = cGVOPo_gv;
2201 if (SvTYPE(gv) == SVt_PVGV && GvCV(gv) && SvPVX_const(GvCV(gv))) {
2202 /* XXX could check prototype here instead of just carping */
2203 SV * const sv = sv_newmortal();
2204 gv_efullname3(sv, gv, NULL);
2205 Perl_warner(aTHX_ packWARN(WARN_PROTOTYPE),
2206 "%"SVf"() called too early to check prototype",
2207 SVfARG(sv));
2208 }
2209 }
2210 break;
2211
2212 case OP_CONST:
eb796c7f
GG
2213 if (cSVOPo->op_private & OPpCONST_STRICT)
2214 no_bareword_allowed(o);
2215 /* FALLTHROUGH */
d164302a
GG
2216#ifdef USE_ITHREADS
2217 case OP_HINTSEVAL:
b46e009d 2218 op_relocate_sv(&cSVOPo->op_sv, &o->op_targ);
2219#endif
2220 break;
2221
2222#ifdef USE_ITHREADS
2223 /* Relocate all the METHOP's SVs to the pad for thread safety. */
d164302a 2224 case OP_METHOD_NAMED:
b46e009d 2225 op_relocate_sv(&cMETHOPx(o)->op_u.op_meth_sv, &o->op_targ);
2226 break;
d164302a 2227#endif
d164302a
GG
2228
2229 case OP_HELEM: {
2230 UNOP *rop;
2231 SV *lexname;
2232 GV **fields;
565e6f7e
FC
2233 SVOP *key_op;
2234 OP *kid;
2235 bool check_fields;
d164302a 2236
565e6f7e 2237 if ((key_op = cSVOPx(((BINOP*)o)->op_last))->op_type != OP_CONST)
d164302a
GG
2238 break;
2239
2240 rop = (UNOP*)((BINOP*)o)->op_first;
e6307ed0 2241
565e6f7e 2242 goto check_keys;
d164302a 2243
565e6f7e 2244 case OP_HSLICE:
429a2555 2245 S_scalar_slice_warning(aTHX_ o);
c67159e1 2246 /* FALLTHROUGH */
429a2555 2247
c5f75dba 2248 case OP_KVHSLICE:
1ed44841 2249 kid = OP_SIBLING(cLISTOPo->op_first);
71323522 2250 if (/* I bet there's always a pushmark... */
7d3c8a68
SM
2251 OP_TYPE_ISNT_AND_WASNT_NN(kid, OP_LIST)
2252 && OP_TYPE_ISNT_NN(kid, OP_CONST))
2253 {
d164302a 2254 break;
7d3c8a68 2255 }
565e6f7e
FC
2256
2257 key_op = (SVOP*)(kid->op_type == OP_CONST
2258 ? kid
1ed44841 2259 : OP_SIBLING(kLISTOP->op_first));
565e6f7e
FC
2260
2261 rop = (UNOP*)((LISTOP*)o)->op_last;
2262
2263 check_keys:
2264 if (o->op_private & OPpLVAL_INTRO || rop->op_type != OP_RV2HV)
71323522 2265 rop = NULL;
565e6f7e 2266 else if (rop->op_first->op_type == OP_PADSV)
d164302a
GG
2267 /* @$hash{qw(keys here)} */
2268 rop = (UNOP*)rop->op_first;
565e6f7e 2269 else {
d164302a
GG
2270 /* @{$hash}{qw(keys here)} */
2271 if (rop->op_first->op_type == OP_SCOPE
2272 && cLISTOPx(rop->op_first)->op_last->op_type == OP_PADSV)
2273 {
2274 rop = (UNOP*)cLISTOPx(rop->op_first)->op_last;
2275 }
2276 else
71323522 2277 rop = NULL;
d164302a 2278 }
71323522 2279
32e9ec8f 2280 lexname = NULL; /* just to silence compiler warnings */
03acb648
DM
2281 fields = NULL; /* just to silence compiler warnings */
2282
71323522
FC
2283 check_fields =
2284 rop
2285 && (lexname = *av_fetch(PL_comppad_name, rop->op_targ, TRUE),
2286 SvPAD_TYPED(lexname))
2287 && (fields = (GV**)hv_fetchs(SvSTASH(lexname), "FIELDS", FALSE))
2288 && isGV(*fields) && GvHV(*fields);
0e706dd4 2289 for (; key_op;
1ed44841 2290 key_op = (SVOP*)OP_SIBLING(key_op)) {
565e6f7e 2291 SV **svp, *sv;
d164302a
GG
2292 if (key_op->op_type != OP_CONST)
2293 continue;
2294 svp = cSVOPx_svp(key_op);
71323522
FC
2295
2296 /* Make the CONST have a shared SV */
2297 if ((!SvIsCOW_shared_hash(sv = *svp))
2298 && SvTYPE(sv) < SVt_PVMG && SvOK(sv) && !SvROK(sv)) {
2299 SSize_t keylen;
2300 const char * const key = SvPV_const(sv, *(STRLEN*)&keylen);
2301 SV *nsv = newSVpvn_share(key,
2302 SvUTF8(sv) ? -keylen : keylen, 0);
2303 SvREFCNT_dec_NN(sv);
2304 *svp = nsv;
2305 }
2306
2307 if (check_fields
2308 && !hv_fetch_ent(GvHV(*fields), *svp, FALSE, 0)) {
ce16c625 2309 Perl_croak(aTHX_ "No such class field \"%"SVf"\" "
84cf752c 2310 "in variable %"SVf" of type %"HEKf,
ce16c625 2311 SVfARG(*svp), SVfARG(lexname),
84cf752c 2312 HEKfARG(HvNAME_HEK(SvSTASH(lexname))));
d164302a
GG
2313 }
2314 }
2315 break;
2316 }
429a2555
FC
2317 case OP_ASLICE:
2318 S_scalar_slice_warning(aTHX_ o);
2319 break;
a7fd8ef6 2320
d164302a
GG
2321 case OP_SUBST: {
2322 if (cPMOPo->op_pmreplrootu.op_pmreplroot)
2323 finalize_op(cPMOPo->op_pmreplrootu.op_pmreplroot);
2324 break;
2325 }
2326 default:
2327 break;
2328 }
2329
2330 if (o->op_flags & OPf_KIDS) {
2331 OP *kid;
c4b20975
DM
2332
2333#ifdef DEBUGGING
20220689
DM
2334 /* check that op_last points to the last sibling, and that
2335 * the last op_sibling field points back to the parent, and
2336 * that the only ops with KIDS are those which are entitled to
2337 * them */
c4b20975
DM
2338 U32 type = o->op_type;
2339 U32 family;
20220689 2340 bool has_last;
c4b20975
DM
2341
2342 if (type == OP_NULL) {
2343 type = o->op_targ;
2344 /* ck_glob creates a null UNOP with ex-type GLOB
2345 * (which is a list op. So pretend it wasn't a listop */
2346 if (type == OP_GLOB)
2347 type = OP_NULL;
2348 }
2349 family = PL_opargs[type] & OA_CLASS_MASK;
2350
20220689
DM
2351 has_last = ( family == OA_BINOP
2352 || family == OA_LISTOP
2353 || family == OA_PMOP
2354 || family == OA_LOOP
2355 );
2356 assert( has_last /* has op_first and op_last, or ...
2357 ... has (or may have) op_first: */
2358 || family == OA_UNOP
2359 || family == OA_LOGOP
2360 || family == OA_BASEOP_OR_UNOP
2361 || family == OA_FILESTATOP
2362 || family == OA_LOOPEXOP
b46e009d 2363 || family == OA_METHOP
20220689
DM
2364 /* I don't know why SASSIGN is tagged as OA_BASEOP - DAPM */
2365 || type == OP_SASSIGN
2366 || type == OP_CUSTOM
2367 || type == OP_NULL /* new_logop does this */
2368 );
2369 /* XXX list form of 'x' is has a null op_last. This is wrong,
2370 * but requires too much hacking (e.g. in Deparse) to fix for
2371 * now */
2372 if (type == OP_REPEAT && (o->op_private & OPpREPEAT_DOLIST)) {
2373 assert(has_last);
2374 has_last = 0;
2375 }
2376
2377 for (kid = cUNOPo->op_first; kid; kid = OP_SIBLING(kid)) {
29e61fd9 2378# ifdef PERL_OP_PARENT
20220689
DM
2379 if (!OP_HAS_SIBLING(kid)) {
2380 if (has_last)
29e61fd9 2381 assert(kid == cLISTOPo->op_last);
20220689
DM
2382 assert(kid->op_sibling == o);
2383 }
29e61fd9 2384# else
20220689
DM
2385 if (OP_HAS_SIBLING(kid)) {
2386 assert(!kid->op_lastsib);
2387 }
2388 else {
2389 assert(kid->op_lastsib);
2390 if (has_last)
29e61fd9 2391 assert(kid == cLISTOPo->op_last);
c4b20975 2392 }
20220689 2393# endif
c4b20975
DM
2394 }
2395#endif
2396
1ed44841 2397 for (kid = cUNOPo->op_first; kid; kid = OP_SIBLING(kid))
d164302a
GG
2398 finalize_op(kid);
2399 }
2400}
2401
2402/*
3ad73efd
Z
2403=for apidoc Amx|OP *|op_lvalue|OP *o|I32 type
2404
2405Propagate lvalue ("modifiable") context to an op and its children.
2406I<type> represents the context type, roughly based on the type of op that
2407would do the modifying, although C<local()> is represented by OP_NULL,
2408because it has no op type of its own (it is signalled by a flag on
001c3c51
FC
2409the lvalue op).
2410
2411This function detects things that can't be modified, such as C<$x+1>, and
72d33970 2412generates errors for them. For example, C<$x+1 = 2> would cause it to be
001c3c51
FC
2413called with an op of type OP_ADD and a C<type> argument of OP_SASSIGN.
2414
2415It also flags things that need to behave specially in an lvalue context,
2416such as C<$$x = 5> which might have to vivify a reference in C<$x>.
3ad73efd
Z
2417
2418=cut
2419*/
ddeae0f1 2420
375879aa
FC
2421static bool
2422S_vivifies(const OPCODE type)
2423{
2424 switch(type) {
2425 case OP_RV2AV: case OP_ASLICE:
2426 case OP_RV2HV: case OP_KVASLICE:
2427 case OP_RV2SV: case OP_HSLICE:
2428 case OP_AELEMFAST: case OP_KVHSLICE:
2429 case OP_HELEM:
2430 case OP_AELEM:
2431 return 1;
2432 }
2433 return 0;
2434}
2435
7664512e 2436static void
63702de8 2437S_lvref(pTHX_ OP *o, I32 type)
7664512e 2438{
727d2dc6 2439 dVAR;
7664512e
FC
2440 OP *kid;
2441 switch (o->op_type) {
2442 case OP_COND_EXPR:
2443 for (kid = OP_SIBLING(cUNOPo->op_first); kid;
2444 kid = OP_SIBLING(kid))
63702de8 2445 S_lvref(aTHX_ kid, type);
7664512e
FC
2446 /* FALLTHROUGH */
2447 case OP_PUSHMARK:
2448 return;
2449 case OP_RV2AV:
2450 if (cUNOPo->op_first->op_type != OP_GV) goto badref;
2451 o->op_flags |= OPf_STACKED;
2452 if (o->op_flags & OPf_PARENS) {
2453 if (o->op_private & OPpLVAL_INTRO) {
7664512e
FC
2454 yyerror(Perl_form(aTHX_ "Can't modify reference to "
2455 "localized parenthesized array in list assignment"));
2456 return;
2457 }
2458 slurpy:
10884df9 2459 CHANGE_TYPE(o, OP_LVAVREF);
7664512e
FC
2460 o->op_private &= OPpLVAL_INTRO|OPpPAD_STATE;
2461 o->op_flags |= OPf_MOD|OPf_REF;
2462 return;
2463 }
2464 o->op_private |= OPpLVREF_AV;
2465 goto checkgv;
408e9044 2466 case OP_RV2CV:
19abb1ea
FC
2467 kid = cUNOPo->op_first;
2468 if (kid->op_type == OP_NULL)
2469 kid = cUNOPx(kUNOP->op_first->op_sibling)
408e9044
FC
2470 ->op_first;
2471 o->op_private = OPpLVREF_CV;
2472 if (kid->op_type == OP_GV)
2473 o->op_flags |= OPf_STACKED;
2474 else if (kid->op_type == OP_PADCV) {
2475 o->op_targ = kid->op_targ;
2476 kid->op_targ = 0;
2477 op_free(cUNOPo->op_first);
2478 cUNOPo->op_first = NULL;
2479 o->op_flags &=~ OPf_KIDS;
2480 }
2481 else goto badref;
2482 break;
7664512e
FC
2483 case OP_RV2HV:
2484 if (o->op_flags & OPf_PARENS) {
2485 parenhash:
7664512e
FC
2486 yyerror(Perl_form(aTHX_ "Can't modify reference to "
2487 "parenthesized hash in list assignment"));
2488 return;
2489 }
2490 o->op_private |= OPpLVREF_HV;
2491 /* FALLTHROUGH */
2492 case OP_RV2SV:
2493 checkgv:
2494 if (cUNOPo->op_first->op_type != OP_GV) goto badref;
2495 o->op_flags |= OPf_STACKED;
6f5dab3c
FC
2496 break;
2497 case OP_PADHV:
2498 if (o->op_flags & OPf_PARENS) goto parenhash;
2499 o->op_private |= OPpLVREF_HV;
7664512e
FC
2500 /* FALLTHROUGH */
2501 case OP_PADSV:
6f5dab3c 2502 PAD_COMPNAME_GEN_set(o->op_targ, PERL_INT_MAX);
7664512e
FC
2503 break;
2504 case OP_PADAV:
6f5dab3c 2505 PAD_COMPNAME_GEN_set(o->op_targ, PERL_INT_MAX);
7664512e
FC
2506 if (o->op_flags & OPf_PARENS) goto slurpy;
2507 o->op_private |= OPpLVREF_AV;
2508 break;
7664512e
FC
2509 case OP_AELEM:
2510 case OP_HELEM:
2511 o->op_private |= OPpLVREF_ELEM;
2512 o->op_flags |= OPf_STACKED;
2513 break;
2514 case OP_ASLICE:
2515 case OP_HSLICE:
10884df9 2516 CHANGE_TYPE(o, OP_LVREFSLICE);
7664512e
FC
2517 o->op_private &= OPpLVAL_INTRO|OPpLVREF_ELEM;
2518 return;
2519 case OP_NULL:
2520 if (o->op_flags & OPf_SPECIAL) /* do BLOCK */
2521 goto badref;
2522 else if (!(o->op_flags & OPf_KIDS))
2523 return;
2524 if (o->op_targ != OP_LIST) {
63702de8 2525 S_lvref(aTHX_ cBINOPo->op_first, type);
7664512e
FC
2526 return;
2527 }
2528 /* FALLTHROUGH */
2529 case OP_LIST:
2530 for (kid = cLISTOPo->op_first; kid; kid = OP_SIBLING(kid)) {
2531 assert((kid->op_flags & OPf_WANT) != OPf_WANT_VOID);
63702de8 2532 S_lvref(aTHX_ kid, type);
7664512e
FC
2533 }
2534 return;
2535 case OP_STUB:
2536 if (o->op_flags & OPf_PARENS)
2537 return;
2538 /* FALLTHROUGH */
2539 default:
2540 badref:
cf6e1fa1 2541 /* diag_listed_as: Can't modify reference to %s in %s assignment */
63702de8 2542 yyerror(Perl_form(aTHX_ "Can't modify reference to %s in %s",
7664512e
FC
2543 o->op_type == OP_NULL && o->op_flags & OPf_SPECIAL
2544 ? "do block"
63702de8
FC
2545 : OP_DESC(o),
2546 PL_op_desc[type]));
7664512e
FC
2547 return;
2548 }
10884df9 2549 CHANGE_TYPE(o, OP_LVREF);
3ad7d304
FC
2550 o->op_private &=
2551 OPpLVAL_INTRO|OPpLVREF_ELEM|OPpLVREF_TYPE|OPpPAD_STATE;
d39c26a6
FC
2552 if (type == OP_ENTERLOOP)
2553 o->op_private |= OPpLVREF_ITER;
7664512e
FC
2554}
2555
79072805 2556OP *
d3d7d28f 2557Perl_op_lvalue_flags(pTHX_ OP *o, I32 type, U32 flags)
79072805 2558{
27da23d5 2559 dVAR;
79072805 2560 OP *kid;
ddeae0f1
DM
2561 /* -1 = error on localize, 0 = ignore localize, 1 = ok to localize */
2562 int localize = -1;
79072805 2563
13765c85 2564 if (!o || (PL_parser && PL_parser->error_count))
11343788 2565 return o;
79072805 2566
b162f9ea 2567 if ((o->op_private & OPpTARGET_MY)
7e363e51
GS
2568 && (PL_opargs[o->op_type] & OA_TARGLEX))/* OPp share the meaning */
2569 {
b162f9ea 2570 return o;
7e363e51 2571 }
1c846c1f 2572
5c906035
GG
2573 assert( (o->op_flags & OPf_WANT) != OPf_WANT_VOID );
2574
69974ce6
FC
2575 if (type == OP_PRTF || type == OP_SPRINTF) type = OP_ENTERSUB;
2576
11343788 2577 switch (o->op_type) {
68dc0745 2578 case OP_UNDEF:
3280af22 2579 PL_modcount++;
5dc0d613 2580 return o;
5f05dabc 2581 case OP_STUB:
b5bbe64a 2582 if ((o->op_flags & OPf_PARENS))
5f05dabc
PP
2583 break;
2584 goto nomod;
a0d0e21e 2585 case OP_ENTERSUB:
f79aa60b 2586 if ((type == OP_UNDEF || type == OP_REFGEN || type == OP_LOCK) &&
11343788 2587 !(o->op_flags & OPf_STACKED)) {
10884df9 2588 CHANGE_TYPE(o, OP_RV2CV); /* entersub => rv2cv */
11343788 2589 assert(cUNOPo->op_first->op_type == OP_NULL);
93c66552 2590 op_null(((LISTOP*)cUNOPo->op_first)->op_first);/* disable pushmark */
79072805
LW
2591 break;
2592 }
cd06dffe 2593 else { /* lvalue subroutine call */
9411a3c7 2594 o->op_private |= OPpLVAL_INTRO;
e6438c1a 2595 PL_modcount = RETURN_UNLIMITED_NUMBER;
9411a3c7
FC
2596 if (type == OP_GREPSTART || type == OP_ENTERSUB
2597 || type == OP_REFGEN || type == OP_LEAVESUBLV) {
d0887bf3 2598 /* Potential lvalue context: */
cd06dffe
GS
2599 o->op_private |= OPpENTERSUB_INARGS;
2600 break;
2601 }
2602 else { /* Compile-time error message: */
2603 OP *kid = cUNOPo->op_first;
2604 CV *cv;
2eaf799e 2605 GV *gv;
cd06dffe 2606
3ea285d1
AL
2607 if (kid->op_type != OP_PUSHMARK) {
2608 if (kid->op_type != OP_NULL || kid->op_targ != OP_LIST)
2609 Perl_croak(aTHX_
2610 "panic: unexpected lvalue entersub "
2611 "args: type/targ %ld:%"UVuf,
2612 (long)kid->op_type, (UV)kid->op_targ);
2613 kid = kLISTOP->op_first;
2614 }
1ed44841
DM
2615 while (OP_HAS_SIBLING(kid))
2616 kid = OP_SIBLING(kid);
cd06dffe 2617 if (!(kid->op_type == OP_NULL && kid->op_targ == OP_RV2CV)) {
cd06dffe
GS
2618 break; /* Postpone until runtime */
2619 }
b2ffa427 2620
cd06dffe
GS
2621 kid = kUNOP->op_first;
2622 if (kid->op_type == OP_NULL && kid->op_targ == OP_RV2SV)
2623 kid = kUNOP->op_first;
b2ffa427 2624 if (kid->op_type == OP_NULL)
cd06dffe
GS
2625 Perl_croak(aTHX_
2626 "Unexpected constant lvalue entersub "
55140b79 2627 "entry via type/targ %ld:%"UVuf,
3d811634 2628 (long)kid->op_type, (UV)kid->op_targ);
cd06dffe 2629 if (kid->op_type != OP_GV) {
cd06dffe
GS
2630 break;
2631 }
b2ffa427 2632
2eaf799e
FC
2633 gv = kGVOP_gv;
2634 cv = isGV(gv)
2635 ? GvCV(gv)
2636 : SvROK(gv) && SvTYPE(SvRV(gv)) == SVt_PVCV
2637 ? MUTABLE_CV(SvRV(gv))
2638 : NULL;
1c846c1f 2639 if (!cv)
da1dff94 2640 break;
cd06dffe
GS
2641 if (CvLVALUE(cv))
2642 break;
2643 }
2644 }
924ba076 2645 /* FALLTHROUGH */
79072805 2646 default:
a0d0e21e 2647 nomod:
f5d552b4 2648 if (flags & OP_LVALUE_NO_CROAK) return NULL;
6fbb66d6 2649 /* grep, foreach, subcalls, refgen */
145b2bbb
FC
2650 if (type == OP_GREPSTART || type == OP_ENTERSUB
2651 || type == OP_REFGEN || type == OP_LEAVESUBLV)
a0d0e21e 2652 break;
cea2e8a9 2653 yyerror(Perl_form(aTHX_ "Can't modify %s in %s",
638bc118 2654 (o->op_type == OP_NULL && (o->op_flags & OPf_SPECIAL)
cd06dffe
GS
2655 ? "do block"
2656 : (o->op_type == OP_ENTERSUB
2657 ? "non-lvalue subroutine call"
53e06cf0 2658 : OP_DESC(o))),
22c35a8c 2659 type ? PL_op_desc[type] : "local"));
11343788 2660 return o;
79072805 2661
a0d0e21e
LW
2662 case OP_PREINC:
2663 case OP_PREDEC:
2664 case OP_POW:
2665 case OP_MULTIPLY:
2666 case OP_DIVIDE:
2667 case OP_MODULO:
a0d0e21e
LW
2668 case OP_ADD:
2669 case OP_SUBTRACT:
2670 case OP_CONCAT:
2671 case OP_LEFT_SHIFT:
2672 case OP_RIGHT_SHIFT:
2673 case OP_BIT_AND:
2674 case OP_BIT_XOR:
2675 case OP_BIT_OR:
2676 case OP_I_MULTIPLY:
2677 case OP_I_DIVIDE:
2678 case OP_I_MODULO:
2679 case OP_I_ADD:
2680 case OP_I_SUBTRACT:
11343788 2681 if (!(o->op_flags & OPf_STACKED))
a0d0e21e 2682 goto nomod;
3280af22 2683 PL_modcount++;
a0d0e21e 2684 break;
b2ffa427 2685
82209a5d
FC
2686 case OP_REPEAT:
2687 if (o->op_flags & OPf_STACKED) {
2688 PL_modcount++;
2689 break;
2690 }
ff781254 2691 if (!(o->op_private & OPpREPEAT_DOLIST))
82209a5d
FC
2692 goto nomod;
2693 else {
2694 const I32 mods = PL_modcount;
ff781254
FC
2695 modkids(cBINOPo->op_first, type);
2696 if (type != OP_AASSIGN)
2697 goto nomod;
5e462669 2698 kid = cBINOPo->op_last;
82209a5d 2699 if (kid->op_type == OP_CONST && SvIOK(kSVOP_sv)) {
565e104c 2700 const IV iv = SvIV(kSVOP_sv);
82209a5d
FC
2701 if (PL_modcount != RETURN_UNLIMITED_NUMBER)
2702 PL_modcount =
2703 mods + (PL_modcount - mods) * (iv < 0 ? 0 : iv);
2704 }
2705 else
2706 PL_modcount = RETURN_UNLIMITED_NUMBER;
2707 }
2708 break;
2709
79072805 2710 case OP_COND_EXPR:
ddeae0f1 2711 localize = 1;
1ed44841 2712 for (kid = OP_SIBLING(cUNOPo->op_first); kid; kid = OP_SIBLING(kid))
3ad73efd 2713 op_lvalue(kid, type);
79072805
LW
2714 break;
2715
2716 case OP_RV2AV:
2717 case OP_RV2HV:
11343788 2718 if (type == OP_REFGEN && o->op_flags & OPf_PARENS) {
e6438c1a 2719 PL_modcount = RETURN_UNLIMITED_NUMBER;
11343788 2720 return o; /* Treat \(@foo) like ordinary list. */
748a9306 2721 }
924ba076 2722 /* FALLTHROUGH */
79072805 2723 case OP_RV2GV:
5dc0d613 2724 if (scalar_mod_type(o, type))
3fe9a6f1 2725 goto nomod;
11343788 2726 ref(cUNOPo->op_first, o->op_type);
924ba076 2727 /* FALLTHROUGH */
79072805
LW
2728 case OP_ASLICE:
2729 case OP_HSLICE:
ddeae0f1 2730 localize = 1;
924ba076 2731 /* FALLTHROUGH */
78f9721b 2732 case OP_AASSIGN:
32cbae3f
FC
2733 /* Do not apply the lvsub flag for rv2[ah]v in scalar context. */
2734 if (type == OP_LEAVESUBLV && (
2735 (o->op_type != OP_RV2AV && o->op_type != OP_RV2HV)
2736 || (o->op_flags & OPf_WANT) != OPf_WANT_SCALAR
2737 ))
631dbaa2 2738 o->op_private |= OPpMAYBE_LVSUB;
924ba076 2739 /* FALLTHROUGH */
93a17b20
LW
2740 case OP_NEXTSTATE:
2741 case OP_DBSTATE:
e6438c1a 2742 PL_modcount = RETURN_UNLIMITED_NUMBER;
79072805 2743 break;
5cae3edb 2744 case OP_KVHSLICE:
6dd3e0f2 2745 case OP_KVASLICE:
5cae3edb
RZ
2746 if (type == OP_LEAVESUBLV)
2747 o->op_private |= OPpMAYBE_LVSUB;
2748 goto nomod;
28c5b5bc
RGS
2749 case OP_AV2ARYLEN:
2750 PL_hints |= HINT_BLOCK_SCOPE;
2751 if (type == OP_LEAVESUBLV)
2752 o->op_private |= OPpMAYBE_LVSUB;
2753 PL_modcount++;
2754 break;
463ee0b2 2755 case OP_RV2SV:
aeea060c 2756 ref(cUNOPo->op_first, o->op_type);
ddeae0f1 2757 localize = 1;
924ba076 2758 /* FALLTHROUGH */
79072805 2759 case OP_GV:
3280af22 2760 PL_hints |= HINT_BLOCK_SCOPE;
924ba076 2761 /* FALLTHROUGH */
463ee0b2 2762 case OP_SASSIGN:
bf4b1e52
GS
2763 case OP_ANDASSIGN:
2764 case OP_ORASSIGN:
c963b151 2765 case OP_DORASSIGN:
ddeae0f1
DM
2766 PL_modcount++;
2767 break;
2768
8990e307 2769 case OP_AELEMFAST:
93bad3fd 2770 case OP_AELEMFAST_LEX:
6a077020 2771 localize = -1;
3280af22 2772 PL_modcount++;
8990e307
LW
2773 break;
2774
748a9306
LW
2775 case OP_PADAV:
2776 case OP_PADHV:
e6438c1a 2777 PL_modcount = RETURN_UNLIMITED_NUMBER;
5196be3e
MB
2778 if (type == OP_REFGEN && o->op_flags & OPf_PARENS)
2779 return o; /* Treat \(@foo) like ordinary list. */
2780 if (scalar_mod_type(o, type))
3fe9a6f1 2781 goto nomod;
32cbae3f
FC
2782 if ((o->op_flags & OPf_WANT) != OPf_WANT_SCALAR
2783 && type == OP_LEAVESUBLV)
78f9721b 2784 o->op_private |= OPpMAYBE_LVSUB;
924ba076 2785 /* FALLTHROUGH */
748a9306 2786 case OP_PADSV:
3280af22 2787 PL_modcount++;
ddeae0f1 2788 if (!type) /* local() */
5ede95a0
BF
2789 Perl_croak(aTHX_ "Can't localize lexical variable %"SVf,
2790 PAD_COMPNAME_SV(o->op_targ));
463ee0b2
LW
2791 break;
2792
748a9306 2793 case OP_PUSHMARK:
ddeae0f1 2794 localize = 0;
748a9306 2795 break;
b2ffa427 2796
69969c6f 2797 case OP_KEYS:
d8065907 2798 case OP_RKEYS:
fad4a2e4 2799 if (type != OP_SASSIGN && type != OP_LEAVESUBLV)
69969c6f 2800 goto nomod;
5d82c453
GA
2801 goto lvalue_func;
2802 case OP_SUBSTR:
2803 if (o->op_private == 4) /* don't allow 4 arg substr as lvalue */
2804 goto nomod;
924ba076 2805 /* FALLTHROUGH */
a0d0e21e 2806 case OP_POS:
463ee0b2 2807 case OP_VEC:
fad4a2e4 2808 lvalue_func:
78f9721b
SM
2809 if (type == OP_LEAVESUBLV)
2810 o->op_private |= OPpMAYBE_LVSUB;
11343788 2811 if (o->op_flags & OPf_KIDS)
1ed44841 2812 op_lvalue(OP_SIBLING(cBINOPo->op_first), type);
463ee0b2 2813 break;
a0d0e21e 2814
463ee0b2
LW
2815 case OP_AELEM:
2816 case OP_HELEM:
11343788 2817 ref(cBINOPo->op_first, o->op_type);
68dc0745 2818 if (type == OP_ENTERSUB &&
5dc0d613
MB
2819 !(o->op_private & (OPpLVAL_INTRO | OPpDEREF)))
2820 o->op_private |= OPpLVAL_DEFER;
78f9721b
SM
2821 if (type == OP_LEAVESUBLV)
2822 o->op_private |= OPpMAYBE_LVSUB;
ddeae0f1 2823 localize = 1;
3280af22 2824 PL_modcount++;
463ee0b2
LW
2825 break;
2826
463ee0b2 2827 case OP_LEAVE:
a373464f 2828 case OP_LEAVELOOP:
2ec7f6f2 2829 o->op_private |= OPpLVALUE;
924ba076 2830 /* FALLTHROUGH */
2ec7f6f2 2831 case OP_SCOPE:
463ee0b2 2832 case OP_ENTER:
78f9721b 2833 case OP_LINESEQ:
ddeae0f1 2834 localize = 0;
11343788 2835 if (o->op_flags & OPf_KIDS)
3ad73efd 2836 op_lvalue(cLISTOPo->op_last, type);
a0d0e21e
LW
2837 break;
2838
2839 case OP_NULL:
ddeae0f1 2840 localize = 0;
638bc118
GS
2841 if (o->op_flags & OPf_SPECIAL) /* do BLOCK */
2842 goto nomod;
2843 else if (!(o->op_flags & OPf_KIDS))
463ee0b2 2844 break;
11343788 2845 if (o->op_targ != OP_LIST) {
3ad73efd 2846 op_lvalue(cBINOPo->op_first, type);
a0d0e21e
LW
2847 break;
2848 }
924ba076 2849 /* FALLTHROUGH */
463ee0b2 2850 case OP_LIST:
ddeae0f1 2851 localize = 0;
1ed44841 2852 for (kid = cLISTOPo->op_first; kid; kid = OP_SIBLING(kid))
5c906035
GG
2853 /* elements might be in void context because the list is
2854 in scalar context or because they are attribute sub calls */
2855 if ( (kid->op_flags & OPf_WANT) != OPf_WANT_VOID )
2856 op_lvalue(kid, type);
463ee0b2 2857 break;
78f9721b 2858
1efec5ed
FC
2859 case OP_COREARGS:
2860 return o;
2ec7f6f2
FC
2861
2862 case OP_AND:
2863 case OP_OR:
375879aa
FC
2864 if (type == OP_LEAVESUBLV
2865 || !S_vivifies(cLOGOPo->op_first->op_type))
2866 op_lvalue(cLOGOPo->op_first, type);
2867 if (type == OP_LEAVESUBLV
1ed44841
DM
2868 || !S_vivifies(OP_SIBLING(cLOGOPo->op_first)->op_type))
2869 op_lvalue(OP_SIBLING(cLOGOPo->op_first), type);
2ec7f6f2 2870 goto nomod;
26a50d99
FC
2871
2872 case OP_SREFGEN:
d39c26a6
FC
2873 if (type != OP_AASSIGN && type != OP_SASSIGN
2874 && type != OP_ENTERLOOP)
2875 goto nomod;
7664512e 2876 /* Don’t bother applying lvalue context to the ex-list. */
26a50d99 2877 kid = cUNOPx(cUNOPo->op_first)->op_first;
217e3565
FC
2878 assert (!OP_HAS_SIBLING(kid));
2879 goto kid_2lvref;
2880 case OP_REFGEN:
2881 if (type != OP_AASSIGN) goto nomod;
7664512e
FC
2882 kid = cUNOPo->op_first;
2883 kid_2lvref:
2884 {
2885 const U8 ec = PL_parser ? PL_parser->error_count : 0;
63702de8 2886 S_lvref(aTHX_ kid, type);
7664512e 2887 if (!PL_parser || PL_parser->error_count == ec) {
baabe3fb 2888 if (!FEATURE_REFALIASING_IS_ENABLED)
7664512e 2889 Perl_croak(aTHX_
baabe3fb 2890 "Experimental aliasing via reference not enabled");
7664512e 2891 Perl_ck_warner_d(aTHX_
baabe3fb
FC
2892 packWARN(WARN_EXPERIMENTAL__REFALIASING),
2893 "Aliasing via reference is experimental");
7664512e
FC
2894 }
2895 }
217e3565
FC
2896 if (o->op_type == OP_REFGEN)
2897 op_null(cUNOPx(cUNOPo->op_first)->op_first); /* pushmark */
2898 op_null(o);
26a50d99 2899 return o;
e4e95921
FC
2900
2901 case OP_SPLIT:
2902 kid = cLISTOPo->op_first;
2903 if (kid && kid->op_type == OP_PUSHRE &&
2904 ( kid->op_targ
2905 || o->op_flags & OPf_STACKED
2906#ifdef USE_ITHREADS
2907 || ((PMOP*)kid)->op_pmreplrootu.op_pmtargetoff
2908#else
2909 || ((PMOP*)kid)->op_pmreplrootu.op_pmtargetgv
2910#endif
2911 )) {
2912 /* This is actually @array = split. */
2913 PL_modcount = RETURN_UNLIMITED_NUMBER;
2914 break;
2915 }
2916 goto nomod;
463ee0b2 2917 }
58d95175 2918
8be1be90
AMS
2919 /* [20011101.069] File test operators interpret OPf_REF to mean that
2920 their argument is a filehandle; thus \stat(".") should not set
2921 it. AMS 20011102 */
2922 if (type == OP_REFGEN &&
ef69c8fc 2923 PL_check[o->op_type] == Perl_ck_ftst)
8be1be90
AMS
2924 return o;
2925
2926 if (type != OP_LEAVESUBLV)
2927 o->op_flags |= OPf_MOD;
2928
2929 if (type == OP_AASSIGN || type == OP_SASSIGN)
2930 o->op_flags |= OPf_SPECIAL|OPf_REF;
ddeae0f1
DM
2931 else if (!type) { /* local() */
2932 switch (localize) {
2933 case 1:
2934 o->op_private |= OPpLVAL_INTRO;
2935 o->op_flags &= ~OPf_SPECIAL;
2936 PL_hints |= HINT_BLOCK_SCOPE;
2937 break;
2938 case 0:
2939 break;
2940 case -1:
a2a5de95
NC
2941 Perl_ck_warner(aTHX_ packWARN(WARN_SYNTAX),
2942 "Useless localization of %s", OP_DESC(o));
ddeae0f1 2943 }
463ee0b2 2944 }
8be1be90
AMS
2945 else if (type != OP_GREPSTART && type != OP_ENTERSUB
2946 && type != OP_LEAVESUBLV)
2947 o->op_flags |= OPf_REF;
11343788 2948 return o;
463ee0b2
LW
2949}
2950
864dbfa3 2951STATIC bool
5f66b61c 2952S_scalar_mod_type(const OP *o, I32 type)
3fe9a6f1
PP
2953{
2954 switch (type) {
32a60974 2955 case OP_POS:
3fe9a6f1 2956 case OP_SASSIGN:
1efec5ed 2957 if (o && o->op_type == OP_RV2GV)
3fe9a6f1 2958 return FALSE;
924ba076 2959 /* FALLTHROUGH */
3fe9a6f1
PP
2960 case OP_PREINC:
2961 case OP_PREDEC:
2962 case OP_POSTINC:
2963 case OP_POSTDEC:
2964 case OP_I_PREINC:
2965 case OP_I_PREDEC:
2966 case OP_I_POSTINC:
2967 case OP_I_POSTDEC:
2968 case OP_POW:
2969 case OP_MULTIPLY:
2970 case OP_DIVIDE:
2971 case OP_MODULO:
2972 case OP_REPEAT:
2973 case OP_ADD:
2974 case OP_SUBTRACT:
2975 case OP_I_MULTIPLY:
2976 case OP_I_DIVIDE:
2977 case OP_I_MODULO:
2978 case OP_I_ADD:
2979 case OP_I_SUBTRACT:
2980 case OP_LEFT_SHIFT:
2981 case OP_RIGHT_SHIFT:
2982 case OP_BIT_AND:
2983 case OP_BIT_XOR:
2984 case OP_BIT_OR:
2985 case OP_CONCAT:
2986 case OP_SUBST:
2987 case OP_TRANS:
bb16bae8 2988 case OP_TRANSR:
49e9fbe6
GS
2989 case OP_READ:
2990 case OP_SYSREAD:
2991 case OP_RECV:
bf4b1e52
GS
2992 case OP_ANDASSIGN:
2993 case OP_ORASSIGN:
410d09fe 2994 case OP_DORASSIGN:
3fe9a6f1
PP
2995 return TRUE;
2996 default:
2997 return FALSE;
2998 }
2999}
3000
35cd451c 3001STATIC bool
5f66b61c 3002S_is_handle_constructor(const OP *o, I32 numargs)
35cd451c 3003{
7918f24d
NC
3004 PERL_ARGS_ASSERT_IS_HANDLE_CONSTRUCTOR;
3005
35cd451c
GS
3006 switch (o->op_type) {
3007 case OP_PIPE_OP:
3008 case OP_SOCKPAIR:
504618e9 3009 if (numargs == 2)
35cd451c 3010 return TRUE;
924ba076 3011 /* FALLTHROUGH */
35cd451c
GS
3012 case OP_SYSOPEN:
3013 case OP_OPEN:
ded8aa31 3014 case OP_SELECT: /* XXX c.f. SelectSaver.pm */
35cd451c
GS
3015 case OP_SOCKET:
3016 case OP_OPEN_DIR:
3017 case OP_ACCEPT:
504618e9 3018 if (numargs == 1)
35cd451c 3019 return TRUE;
5f66b61c 3020 /* FALLTHROUGH */
35cd451c
GS
3021 default:
3022 return FALSE;
3023 }
3024}
3025
0d86688d
NC
3026static OP *
3027S_refkids(pTHX_ OP *o, I32 type)
463ee0b2 3028{
11343788 3029 if (o && o->op_flags & OPf_KIDS) {
6867be6d 3030 OP *kid;
1ed44841 3031 for (kid = cLISTOPo->op_first; kid; kid = OP_SIBLING(kid))
463ee0b2
LW
3032 ref(kid, type);
3033 }
11343788 3034 return o;
463ee0b2
LW
3035}
3036
3037OP *
e4c5ccf3 3038Perl_doref(pTHX_ OP *o, I32 type, bool set_op_ref)
463ee0b2 3039{
27da23d5 3040 dVAR;
463ee0b2 3041 OP *kid;
463ee0b2 3042
7918f24d
NC
3043 PERL_ARGS_ASSERT_DOREF;
3044
13765c85 3045 if (!o || (PL_parser && PL_parser->error_count))
11343788 3046 return o;
463ee0b2 3047
11343788 3048 switch (o->op_type) {
a0d0e21e 3049 case OP_ENTERSUB:
f4df43b5 3050 if ((type == OP_EXISTS || type == OP_DEFINED) &&
11343788 3051 !(o->op_flags & OPf_STACKED)) {
10884df9 3052 CHANGE_TYPE(o, OP_RV2CV); /* entersub => rv2cv */
11343788 3053 assert(cUNOPo->op_first->op_type == OP_NULL);
93c66552 3054 op_null(((LISTOP*)cUNOPo->op_first)->op_first); /* disable pushmark */
11343788 3055 o->op_flags |= OPf_SPECIAL;
8990e307 3056 }
767eda44 3057 else if (type == OP_RV2SV || type == OP_RV2AV || type == OP_RV2HV){
0e9700df
GG
3058 o->op_private |= (type == OP_RV2AV ? OPpDEREF_AV
3059 : type == OP_RV2HV ? OPpDEREF_HV
3060 : OPpDEREF_SV);
767eda44
FC
3061 o->op_flags |= OPf_MOD;
3062 }
3063
8990e307 3064 break;
aeea060c 3065
463ee0b2 3066 case OP_COND_EXPR:
1ed44841 3067 for (kid = OP_SIBLING(cUNOPo->op_first); kid; kid = OP_SIBLING(kid))
e4c5ccf3 3068 doref(kid, type, set_op_ref);
463ee0b2 3069 break;
8990e307 3070 case OP_RV2SV:
35cd451c
GS
3071 if (type == OP_DEFINED)
3072 o->op_flags |= OPf_SPECIAL; /* don't create GV */
e4c5ccf3 3073 doref(cUNOPo->op_first, o->op_type, set_op_ref);
924ba076 3074 /* FALLTHROUGH */
4633a7c4 3075 case OP_PADSV:
5f05dabc 3076 if (type == OP_RV2SV || type == OP_RV2AV || type == OP_RV2HV) {
5dc0d613
MB
3077 o->op_private |= (type == OP_RV2AV ? OPpDEREF_AV
3078 : type == OP_RV2HV ? OPpDEREF_HV
3079 : OPpDEREF_SV);
11343788 3080 o->op_flags |= OPf_MOD;
a0d0e21e 3081 }
8990e307 3082 break;
1c846c1f 3083
463ee0b2
LW
3084 case OP_RV2AV:
3085 case OP_RV2HV:
e4c5ccf3
RH
3086 if (set_op_ref)
3087 o->op_flags |= OPf_REF;
924ba076 3088 /* FALLTHROUGH */
463ee0b2 3089 case OP_RV2GV:
35cd451c
GS
3090 if (type == OP_DEFINED)
3091 o->op_flags |= OPf_SPECIAL; /* don't create GV */
e4c5ccf3 3092 doref(cUNOPo->op_first, o->op_type, set_op_ref);
463ee0b2 3093 break;
8990e307 3094
463ee0b2
LW
3095 case OP_PADAV:
3096 case OP_PADHV:
e4c5ccf3
RH
3097 if (set_op_ref)
3098 o->op_flags |= OPf_REF;
79072805 3099 break;
aeea060c 3100
8990e307 3101 case OP_SCALAR:
79072805 3102 case OP_NULL:
518618af 3103 if (!(o->op_flags & OPf_KIDS) || type == OP_DEFINED)
463ee0b2 3104 break;
e4c5ccf3 3105 doref(cBINOPo->op_first, type, set_op_ref);
79072805
LW
3106 break;
3107 case OP_AELEM:
3108 case OP_HELEM:
e4c5ccf3 3109 doref(cBINOPo->op_first, o->op_type, set_op_ref);
5f05dabc 3110 if (type == OP_RV2SV || type == OP_RV2AV || type == OP_RV2HV) {
5dc0d613
MB
3111 o->op_private |= (type == OP_RV2AV ? OPpDEREF_AV
3112 : type == OP_RV2HV ? OPpDEREF_HV
3113 : OPpDEREF_SV);
11343788 3114 o->op_flags |= OPf_MOD;
8990e307 3115 }
79072805
LW
3116 break;
3117
463ee0b2 3118 case OP_SCOPE:
79072805 3119 case OP_LEAVE:
e4c5ccf3 3120 set_op_ref = FALSE;
924ba076 3121 /* FALLTHROUGH */
79072805 3122 case OP_ENTER:
8990e307 3123 case OP_LIST:
11343788 3124 if (!(o->op_flags & OPf_KIDS))
79072805 3125 break;
e4c5ccf3 3126 doref(cLISTOPo->op_last, type, set_op_ref);
79072805 3127 break;
a0d0e21e
LW
3128 default:
3129 break;
79072805 3130 }
11343788 3131 return scalar(o);
8990e307 3132
79072805
LW
3133}
3134
09bef843
SB
3135STATIC OP *
3136S_dup_attrlist(pTHX_ OP *o)
3137{
0bd48802 3138 OP *rop;
09bef843 3139
7918f24d
NC
3140 PERL_ARGS_ASSERT_DUP_ATTRLIST;
3141
09bef843
SB
3142 /* An attrlist is either a simple OP_CONST or an OP_LIST with kids,
3143 * where the first kid is OP_PUSHMARK and the remaining ones
3144 * are OP_CONST. We need to push the OP_CONST values.
3145 */
3146 if (o->op_type == OP_CONST)
b37c2d43 3147 rop = newSVOP(OP_CONST, o->op_flags, SvREFCNT_inc_NN(cSVOPo->op_sv));
09bef843
SB
3148 else {
3149 assert((o->op_type == OP_LIST) && (o->op_flags & OPf_KIDS));
5f66b61c 3150 rop = NULL;
1ed44841 3151 for (o = cLISTOPo->op_first; o; o = OP_SIBLING(o)) {
09bef843 3152 if (o->op_type == OP_CONST)
2fcb4757 3153 rop = op_append_elem(OP_LIST, rop,
09bef843 3154 newSVOP(OP_CONST, o->op_flags,
b37c2d43 3155 SvREFCNT_inc_NN(cSVOPo->op_sv)));
09bef843
SB
3156 }
3157 }
3158 return rop;
3159}
3160
3161STATIC void
ad0dc73b 3162S_apply_attrs(pTHX_ HV *stash, SV *target, OP *attrs)
09bef843 3163{
ad0dc73b 3164 SV * const stashsv = stash ? newSVhek(HvNAME_HEK(stash)) : &PL_sv_no;
09bef843 3165
7918f24d
NC
3166 PERL_ARGS_ASSERT_APPLY_ATTRS;
3167
09bef843 3168 /* fake up C<use attributes $pkg,$rv,@attrs> */
e4783991 3169
09bef843 3170#define ATTRSMODULE "attributes"
95f0a2f1
SB
3171#define ATTRSMODULE_PM "attributes.pm"
3172
ad0dc73b 3173 Perl_load_module(aTHX_ PERL_LOADMOD_IMPORT_OPS,
6136c704
AL
3174 newSVpvs(ATTRSMODULE),
3175 NULL,
2fcb4757 3176 op_prepend_elem(OP_LIST,
95f0a2f1 3177 newSVOP(OP_CONST, 0, stashsv),
2fcb4757 3178 op_prepend_elem(OP_LIST,
95f0a2f1
SB
3179 newSVOP(OP_CONST, 0,
3180 newRV(target)),
3181 dup_attrlist(attrs))));
09bef843
SB
3182}
3183
95f0a2f1
SB
3184STATIC void
3185S_apply_attrs_my(pTHX_ HV *stash, OP *target, OP *attrs, OP **imopsp)
3186{
3187 OP *pack, *imop, *arg;
ad0dc73b 3188 SV *meth, *stashsv, **svp;
95f0a2f1 3189
7918f24d
NC
3190 PERL_ARGS_ASSERT_APPLY_ATTRS_MY;
3191
95f0a2f1
SB
3192 if (!attrs)
3193 return;
3194
3195 assert(target->op_type == OP_PADSV ||
3196 target->op_type == OP_PADHV ||
3197 target->op_type == OP_PADAV);
3198
3199 /* Ensure that attributes.pm is loaded. */
ad0dc73b
FC
3200 /* Don't force the C<use> if we don't need it. */
3201 svp = hv_fetchs(GvHVn(PL_incgv), ATTRSMODULE_PM, FALSE);
3202 if (svp && *svp != &PL_sv_undef)
3203 NOOP; /* already in %INC */
3204 else
3205 Perl_load_module(aTHX_ PERL_LOADMOD_NOIMPORT,
3206 newSVpvs(ATTRSMODULE), NULL);
95f0a2f1
SB
3207
3208 /* Need package name for method call. */
6136c704 3209 pack = newSVOP(OP_CONST, 0, newSVpvs(ATTRSMODULE));
95f0a2f1
SB
3210
3211 /* Build up the real arg-list. */
5aaec2b4
NC
3212 stashsv = stash ? newSVhek(HvNAME_HEK(stash)) : &PL_sv_no;
3213
95f0a2f1
SB
3214 arg = newOP(OP_PADSV, 0);
3215 arg->op_targ = target->op_targ;
2fcb4757 3216 arg = op_prepend_elem(OP_LIST,
95f0a2f1 3217 newSVOP(OP_CONST, 0, stashsv),
2fcb4757 3218 op_prepend_elem(OP_LIST,
95f0a2f1 3219 newUNOP(OP_REFGEN, 0,
3ad73efd 3220 op_lvalue(arg, OP_REFGEN)),
95f0a2f1
SB
3221 dup_attrlist(attrs)));
3222
3223 /* Fake up a method call to import */
18916d0d 3224 meth = newSVpvs_share("import");
03d05f6e 3225 imop = op_convert_list(OP_ENTERSUB, OPf_STACKED|OPf_SPECIAL|OPf_WANT_VOID,
2fcb4757 3226 op_append_elem(OP_LIST,
6aa68307 3227 op_prepend_elem(OP_LIST, pack, arg),
b46e009d 3228 newMETHOP_named(OP_METHOD_NAMED, 0, meth)));
95f0a2f1
SB
3229
3230 /* Combine the ops. */
2fcb4757 3231 *imopsp = op_append_elem(OP_LIST, *imopsp, imop);
95f0a2f1
SB
3232}
3233
3234/*
3235=notfor apidoc apply_attrs_string
3236
3237Attempts to apply a list of attributes specified by the C<attrstr> and
3238C<len> arguments to the subroutine identified by the C<cv> argument which
3239is expected to be associated with the package identified by the C<stashpv>
3240argument (see L<attributes>). It gets this wrong, though, in that it
3241does not correctly identify the boundaries of the individual attribute
3242specifications within C<attrstr>. This is not really intended for the
3243public API, but has to be listed here for systems such as AIX which
3244need an explicit export list for symbols. (It's called from XS code
3245in support of the C<ATTRS:> keyword from F<xsubpp>.) Patches to fix it
3246to respect attribute syntax properly would be welcome.
3247
3248=cut
3249*/
3250
be3174d2 3251void
6867be6d
AL
3252Perl_apply_attrs_string(pTHX_ const char *stashpv, CV *cv,
3253 const char *attrstr, STRLEN len)
be3174d2 3254{
5f66b61c 3255 OP *attrs = NULL;
be3174d2 3256
7918f24d
NC
3257 PERL_ARGS_ASSERT_APPLY_ATTRS_STRING;
3258
be3174d2
GS
3259 if (!len) {
3260 len = strlen(attrstr);
3261 }
3262
3263 while (len) {
3264 for (; isSPACE(*attrstr) && len; --len, ++attrstr) ;
3265 if (len) {
890ce7af 3266 const char * const sstr = attrstr;
be3174d2 3267 for (; !isSPACE(*attrstr) && len; --len, ++attrstr) ;
2fcb4757 3268 attrs = op_append_elem(OP_LIST, attrs,
be3174d2
GS
3269 newSVOP(OP_CONST, 0,
3270 newSVpvn(sstr, attrstr-sstr)));
3271 }
3272 }
3273
3274 Perl_load_module(aTHX_ PERL_LOADMOD_IMPORT_OPS,
6136c704 3275 newSVpvs(ATTRSMODULE),
2fcb4757 3276 NULL, op_prepend_elem(OP_LIST,
be3174d2 3277 newSVOP(OP_CONST, 0, newSVpv(stashpv,0)),
2fcb4757 3278 op_prepend_elem(OP_LIST,
be3174d2 3279 newSVOP(OP_CONST, 0,
ad64d0ec 3280 newRV(MUTABLE_SV(cv))),
be3174d2
GS
3281 attrs)));
3282}
3283
eedb00fa
PM
3284STATIC void
3285S_move_proto_attr(pTHX_ OP **proto, OP **attrs, const GV * name)
3286{
3287 OP *new_proto = NULL;
3288 STRLEN pvlen;
3289 char *pv;
3290 OP *o;
3291
3292 PERL_ARGS_ASSERT_MOVE_PROTO_ATTR;
3293
3294 if (!*attrs)
3295 return;
3296
3297 o = *attrs;
3298 if (o->op_type == OP_CONST) {
3299 pv = SvPV(cSVOPo_sv, pvlen);
3300 if (pvlen >= 10 && memEQ(pv, "prototype(", 10)) {
3301 SV * const tmpsv = newSVpvn_flags(pv + 10, pvlen - 11, SvUTF8(cSVOPo_sv));
3302 SV ** const tmpo = cSVOPx_svp(o);
3303 SvREFCNT_dec(cSVOPo_sv);
3304 *tmpo = tmpsv;
3305 new_proto = o;
3306 *attrs = NULL;
3307 }
3308 } else if (o->op_type == OP_LIST) {
e78bc664 3309 OP * lasto;
eedb00fa 3310 assert(o->op_flags & OPf_KIDS);
e78bc664
PM
3311 lasto = cLISTOPo->op_first;
3312 assert(lasto->op_type == OP_PUSHMARK);
1ed44841 3313 for (o = OP_SIBLING(lasto); o; o = OP_SIBLING(o)) {
eedb00fa
PM
3314 if (o->op_type == OP_CONST) {
3315 pv = SvPV(cSVOPo_sv, pvlen);
3316 if (pvlen >= 10 && memEQ(pv, "prototype(", 10)) {
3317 SV * const tmpsv = newSVpvn_flags(pv + 10, pvlen - 11, SvUTF8(cSVOPo_sv));
3318 SV ** const tmpo = cSVOPx_svp(o);
3319 SvREFCNT_dec(cSVOPo_sv);
3320 *tmpo = tmpsv;
3321 if (new_proto && ckWARN(WARN_MISC)) {
3322 STRLEN new_len;
3323 const char * newp = SvPV(cSVOPo_sv, new_len);
3324 Perl_warner(aTHX_ packWARN(WARN_MISC),
3325 "Attribute prototype(%"UTF8f") discards earlier prototype attribute in same sub",
3326 UTF8fARG(SvUTF8(cSVOPo_sv), new_len, newp));
3327 op_free(new_proto);
3328 }
3329 else if (new_proto)
3330 op_free(new_proto);
3331 new_proto = o;
3253bf85
DM
3332 /* excise new_proto from the list */
3333 op_sibling_splice(*attrs, lasto, 1, NULL);
3334 o = lasto;
eedb00fa
PM
3335 continue;
3336 }
3337 }
3338 lasto = o;
3339 }
3340 /* If the list is now just the PUSHMARK, scrap the whole thing; otherwise attributes.xs
3341 would get pulled in with no real need */
1ed44841 3342 if (!OP_HAS_SIBLING(cLISTOPx(*attrs)->op_first)) {
eedb00fa
PM
3343 op_free(*attrs);
3344 *attrs = NULL;
3345 }
3346 }
3347
3348 if (new_proto) {
3349 SV *svname;
3350 if (isGV(name)) {
3351 svname = sv_newmortal();
3352 gv_efullname3(svname, name, NULL);
3353 }
3354 else if (SvPOK(name) && *SvPVX((SV *)name) == '&')
3355 svname = newSVpvn_flags(SvPVX((SV *)name)+1, SvCUR(name)-1, SvUTF8(name)|SVs_TEMP);
3356 else
3357 svname = (SV *)name;
3358 if (ckWARN(WARN_ILLEGALPROTO))
3359 (void)validate_proto(svname, cSVOPx_sv(new_proto), TRUE);
3360 if (*proto && ckWARN(WARN_PROTOTYPE)) {
3361 STRLEN old_len, new_len;
3362 const char * oldp = SvPV(cSVOPx_sv(*proto), old_len);
3363 const char * newp = SvPV(cSVOPx_sv(new_proto), new_len);
3364
3365 Perl_warner(aTHX_ packWARN(WARN_PROTOTYPE),
3366 "Prototype '%"UTF8f"' overridden by attribute 'prototype(%"UTF8f")'"
3367 " in %"SVf,
3368 UTF8fARG(SvUTF8(cSVOPx_sv(*proto)), old_len, oldp),
3369 UTF8fARG(SvUTF8(cSVOPx_sv(new_proto)), new_len, newp),
3370 SVfARG(svname));
3371 }
3372 if (*proto)
3373 op_free(*proto);
3374 *proto = new_proto;
3375 }
3376}
3377
92bd82a0
FC
3378static void
3379S_cant_declare(pTHX_ OP *o)
3380{
4748e002
FC
3381 if (o->op_type == OP_NULL
3382 && (o->op_flags & (OPf_SPECIAL|OPf_KIDS)) == OPf_KIDS)
3383 o = cUNOPo->op_first;
92bd82a0 3384 yyerror(Perl_form(aTHX_ "Can't declare %s in \"%s\"",
4748e002
FC
3385 o->op_type == OP_NULL
3386 && o->op_flags & OPf_SPECIAL
3387 ? "do block"
3388 : OP_DESC(o),
92bd82a0
FC
3389 PL_parser->in_my == KEY_our ? "our" :
3390 PL_parser->in_my == KEY_state ? "state" :
3391 "my"));
3392}
3393
09bef843 3394STATIC OP *
95f0a2f1 3395S_my_kid(pTHX_ OP *o, OP *attrs, OP **imopsp)
93a17b20 3396{
93a17b20 3397 I32 type;
a1fba7eb 3398 const bool stately = PL_parser && PL_parser->in_my == KEY_state;
93a17b20 3399
7918f24d
NC
3400 PERL_ARGS_ASSERT_MY_KID;
3401
13765c85 3402 if (!o || (PL_parser && PL_parser->error_count))
11343788 3403 return o;
93a17b20 3404
bc61e325 3405 type = o->op_type;
eb8433b7 3406
93a17b20 3407 if (type == OP_LIST) {
6867be6d 3408 OP *kid;
1ed44841 3409 for (kid = cLISTOPo->op_first; kid; kid = OP_SIBLING(kid))
95f0a2f1 3410 my_kid(kid, attrs, imopsp);
0865059d 3411 return o;
8b8c1fb9 3412 } else if (type == OP_UNDEF || type == OP_STUB) {
7766148a 3413 return o;
77ca0c92
LW
3414 } else if (type == OP_RV2SV || /* "our" declaration */
3415 type == OP_RV2AV ||
3416 type == OP_RV2HV) { /* XXX does this let anything illegal in? */
1ce0b88c 3417 if (cUNOPo->op_first->op_type != OP_GV) { /* MJD 20011224 */
92bd82a0 3418 S_cant_declare(aTHX_ o);
1ce0b88c 3419 } else if (attrs) {
551405c4 3420 GV * const gv = cGVOPx_gv(cUNOPo->op_first);
316ebaf2 3421 assert(PL_parser);
12bd6ede
DM
3422 PL_parser->in_my = FALSE;
3423 PL_parser->in_my_stash = NULL;
1ce0b88c
RGS
3424 apply_attrs(GvSTASH(gv),
3425 (type == OP_RV2SV ? GvSV(gv) :
ad64d0ec
NC
3426 type == OP_RV2AV ? MUTABLE_SV(GvAV(gv)) :
3427 type == OP_RV2HV ? MUTABLE_SV(GvHV(gv)) : MUTABLE_SV(gv)),
ad0dc73b 3428 attrs);
1ce0b88c 3429 }
192587c2 3430 o->op_private |= OPpOUR_INTRO;
77ca0c92 3431 return o;
95f0a2f1
SB
3432 }
3433 else if (type != OP_PADSV &&
93a17b20
LW
3434 type != OP_PADAV &&
3435 type != OP_PADHV &&
3436 type != OP_PUSHMARK)
3437 {
92bd82a0 3438 S_cant_declare(aTHX_ o);
11343788 3439 return o;
93a17b20 3440 }
09bef843
SB
3441 else if (attrs && type != OP_PUSHMARK) {
3442 HV *stash;
09bef843 3443
316ebaf2 3444 assert(PL_parser);
12bd6ede
DM
3445 PL_parser->in_my = FALSE;
3446 PL_parser->in_my_stash = NULL;
eb64745e 3447
09bef843 3448 /* check for C<my Dog $spot> when deciding package */
dd2155a4
DM
3449 stash = PAD_COMPNAME_TYPE(o->op_targ);
3450 if (!stash)
09bef843 3451 stash = PL_curstash;
95f0a2f1 3452 apply_attrs_my(stash, o, attrs, imopsp);
09bef843 3453 }
11343788
MB
3454 o->op_flags |= OPf_MOD;
3455 o->op_private |= OPpLVAL_INTRO;
a1fba7eb 3456 if (stately)
952306ac 3457 o->op_private |= OPpPAD_STATE;
11343788 3458 return o;
93a17b20
LW
3459}
3460
3461OP *
09bef843
SB
3462Perl_my_attrs(pTHX_ OP *o, OP *attrs)
3463{
0bd48802 3464 OP *rops;
95f0a2f1
SB
3465 int maybe_scalar = 0;
3466
7918f24d
NC
3467 PERL_ARGS_ASSERT_MY_ATTRS;
3468
d2be0de5 3469/* [perl #17376]: this appears to be premature, and results in code such as
c754c3d7 3470 C< our(%x); > executing in list mode rather than void mode */
d2be0de5 3471#if 0
09bef843
SB
3472 if (o->op_flags & OPf_PARENS)
3473 list(o);
95f0a2f1
SB
3474 else
3475 maybe_scalar = 1;
d2be0de5
YST
3476#else
3477 maybe_scalar = 1;
3478#endif
09bef843
SB
3479 if (attrs)
3480 SAVEFREEOP(attrs);
5f66b61c 3481 rops = NULL;
95f0a2f1
SB
3482 o = my_kid(o, attrs, &rops);
3483 if (rops) {
3484 if (maybe_scalar && o->op_type == OP_PADSV) {
2fcb4757 3485 o = scalar(op_append_list(OP_LIST, rops, o));
95f0a2f1
SB
3486 o->op_private |= OPpLVAL_INTRO;
3487 }
f5d1ed10
FC
3488 else {
3489 /* The listop in rops might have a pushmark at the beginning,
3490 which will mess up list assignment. */
3491 LISTOP * const lrops = (LISTOP *)rops; /* for brevity */
3492 if (rops->op_type == OP_LIST &&
3493 lrops->op_first && lrops->op_first->op_type == OP_PUSHMARK)
3494 {
3495 OP * const pushmark = lrops->op_first;
3253bf85
DM
3496 /* excise pushmark */
3497 op_sibling_splice(rops, NULL, 1, NULL);
f5d1ed10
FC
3498 op_free(pushmark);
3499 }
2fcb4757 3500 o = op_append_list(OP_LIST, o, rops);
f5d1ed10 3501 }
95f0a2f1 3502 }
12bd6ede
DM
3503 PL_parser->in_my = FALSE;
3504 PL_parser->in_my_stash = NULL;
eb64745e 3505 return o;
09bef843
SB
3506}
3507
3508OP *
864dbfa3 3509Perl_sawparens(pTHX_ OP *o)
79072805 3510{
96a5add6 3511 PERL_UNUSED_CONTEXT;
79072805
LW
3512 if (o)
3513 o->op_flags |= OPf_PARENS;
3514 return o;
3515}
3516
3517OP *
864dbfa3 3518Perl_bind_match(pTHX_ I32 type, OP *left, OP *right)
79072805 3519{
11343788 3520 OP *o;
59f00321 3521 bool ismatchop = 0;
1496a290
AL
3522 const OPCODE ltype = left->op_type;
3523 const OPCODE rtype = right->op_type;
79072805 3524
7918f24d
NC
3525 PERL_ARGS_ASSERT_BIND_MATCH;
3526
1496a290
AL
3527 if ( (ltype == OP_RV2AV || ltype == OP_RV2HV || ltype == OP_PADAV
3528 || ltype == OP_PADHV) && ckWARN(WARN_MISC))
041457d9 3529 {
1496a290 3530 const char * const desc
bb16bae8
FC
3531 = PL_op_desc[(
3532 rtype == OP_SUBST || rtype == OP_TRANS
3533 || rtype == OP_TRANSR
3534 )
666ea192 3535 ? (int)rtype : OP_MATCH];
c6771ab6 3536 const bool isary = ltype == OP_RV2AV || ltype == OP_PADAV;
c6771ab6 3537 SV * const name =
0920b7fa 3538 S_op_varname(aTHX_ left);
c6771ab6
FC
3539 if (name)
3540 Perl_warner(aTHX_ packWARN(WARN_MISC),
3541 "Applying %s to %"SVf" will act on scalar(%"SVf")",
c1f6cd39 3542 desc, SVfARG(name), SVfARG(name));
c6771ab6
FC
3543 else {
3544 const char * const sample = (isary
666ea192 3545 ? "@array" : "%hash");
c6771ab6 3546 Perl_warner(aTHX_ packWARN(WARN_MISC),
1c846c1f 3547 "Applying %s to %s will act on scalar(%s)",
599cee73 3548 desc, sample, sample);
c6771ab6 3549 }
2ae324a7
PP
3550 }
3551
1496a290 3552 if (rtype == OP_CONST &&
5cc9e5c9
RH
3553 cSVOPx(right)->op_private & OPpCONST_BARE &&
3554 cSVOPx(right)->op_private & OPpCONST_STRICT)
3555 {
3556 no_bareword_allowed(right);
3557 }
3558
bb16bae8 3559 /* !~ doesn't make sense with /r, so error on it for now */
4f4d7508
DC
3560 if (rtype == OP_SUBST && (cPMOPx(right)->op_pmflags & PMf_NONDESTRUCT) &&
3561 type == OP_NOT)
ce0e31fe 3562 /* diag_listed_as: Using !~ with %s doesn't make sense */
4f4d7508 3563 yyerror("Using !~ with s///r doesn't make sense");
bb16bae8 3564 if (rtype == OP_TRANSR && type == OP_NOT)
ce0e31fe 3565 /* diag_listed_as: Using !~ with %s doesn't make sense */
bb16bae8 3566 yyerror("Using !~ with tr///r doesn't make sense");
4f4d7508 3567
2474a784
FC
3568 ismatchop = (rtype == OP_MATCH ||
3569 rtype == OP_SUBST ||
bb16bae8 3570 rtype == OP_TRANS || rtype == OP_TRANSR)
2474a784 3571 && !(right->op_flags & OPf_SPECIAL);
59f00321
RGS
3572 if (ismatchop && right->op_private & OPpTARGET_MY) {
3573 right->op_targ = 0;
3574 right->op_private &= ~OPpTARGET_MY;
3575 }
3576 if (!(right->op_flags & OPf_STACKED) && ismatchop) {
1496a290
AL
3577 OP *newleft;
3578
79072805 3579 right->op_flags |= OPf_STACKED;
bb16bae8 3580 if (rtype != OP_MATCH && rtype != OP_TRANSR &&
1496a290 3581 ! (rtype == OP_TRANS &&
4f4d7508
DC
3582 right->op_private & OPpTRANS_IDENTICAL) &&
3583 ! (rtype == OP_SUBST &&
3584 (cPMOPx(right)->op_pmflags & PMf_NONDESTRUCT)))
3ad73efd 3585 newleft = op_lvalue(left, rtype);
1496a290
AL
3586 else
3587 newleft = left;
bb16bae8 3588 if (right->op_type == OP_TRANS || right->op_type == OP_TRANSR)
1496a290 3589 o = newBINOP(OP_NULL, OPf_STACKED, scalar(newleft), right);
79072805 3590 else
2fcb4757 3591 o = op_prepend_elem(rtype, scalar(newleft), right);
79072805 3592 if (type == OP_NOT)
11343788
MB
3593 return newUNOP(OP_NOT, 0, scalar(o));
3594 return o;
79072805
LW
3595 }
3596 else
3597 return bind_match(type, left,
d63c20f2 3598 pmruntime(newPMOP(OP_MATCH, 0), right, 0, 0));
79072805
LW
3599}
3600
3601OP *
864dbfa3 3602Perl_invert(pTHX_ OP *o)
79072805 3603{
11343788 3604 if (!o)
1d866c12 3605 return NULL;
11343788 3606 return newUNOP(OP_NOT, OPf_SPECIAL, scalar(o));
79072805
LW
3607}
3608
3ad73efd
Z
3609/*
3610=for apidoc Amx|OP *|op_scope|OP *o
3611
3612Wraps up an op tree with some additional ops so that at runtime a dynamic
3613scope will be created. The original ops run in the new dynamic scope,
3614and then, provided that they exit normally, the scope will be unwound.
3615The additional ops used to create and unwind the dynamic scope will
3616normally be an C<enter>/C<leave> pair, but a C<scope> op may be used
3617instead if the ops are simple enough to not need the full dynamic scope
3618structure.
3619
3620=cut
3621*/
3622
79072805 3623OP *
3ad73efd 3624Perl_op_scope(pTHX_ OP *o)
79072805 3625{
27da23d5 3626 dVAR;
79072805 3627 if (o) {
284167a5 3628 if (o->op_flags & OPf_PARENS || PERLDB_NOOPT || TAINTING_get) {
2fcb4757 3629 o = op_prepend_elem(OP_LINESEQ, newOP(OP_ENTER, 0), o);
10884df9 3630 CHANGE_TYPE(o, OP_LEAVE);
463ee0b2 3631 }
fdb22418
HS
3632 else if (o->op_type == OP_LINESEQ) {
3633 OP *kid;
10884df9 3634 CHANGE_TYPE(o, OP_SCOPE);
fdb22418 3635 kid = ((LISTOP*)o)->op_first;
59110972 3636 if (kid->op_type == OP_NEXTSTATE || kid->op_type == OP_DBSTATE) {
fdb22418 3637 op_null(kid);
59110972
RH
3638
3639 /* The following deals with things like 'do {1 for 1}' */
1ed44841 3640 kid = OP_SIBLING(kid);
59110972
RH
3641 if (kid &&
3642 (kid->op_type == OP_NEXTSTATE || kid->op_type == OP_DBSTATE))
3643 op_null(kid);
3644 }
463ee0b2 3645 }
fdb22418 3646 else
5f66b61c 3647 o = newLISTOP(OP_SCOPE, 0, o, NULL);
79072805
LW
3648 }
3649 return o;
3650}