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4b88f280 1#line 2 "op.c"
a0d0e21e 2/* op.c
79072805 3 *
1129b882
NC
4 * Copyright (C) 1991, 1992, 1993, 1994, 1995, 1996, 1997, 1998, 1999, 2000,
5 * 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008 by Larry Wall and others
79072805
LW
6 *
7 * You may distribute under the terms of either the GNU General Public
8 * License or the Artistic License, as specified in the README file.
9 *
a0d0e21e
LW
10 */
11
12/*
4ac71550
TC
13 * 'You see: Mr. Drogo, he married poor Miss Primula Brandybuck. She was
14 * our Mr. Bilbo's first cousin on the mother's side (her mother being the
15 * youngest of the Old Took's daughters); and Mr. Drogo was his second
16 * cousin. So Mr. Frodo is his first *and* second cousin, once removed
17 * either way, as the saying is, if you follow me.' --the Gaffer
18 *
19 * [p.23 of _The Lord of the Rings_, I/i: "A Long-Expected Party"]
79072805
LW
20 */
21
166f8a29
DM
22/* This file contains the functions that create, manipulate and optimize
23 * the OP structures that hold a compiled perl program.
24 *
25 * A Perl program is compiled into a tree of OPs. Each op contains
26 * structural pointers (eg to its siblings and the next op in the
27 * execution sequence), a pointer to the function that would execute the
28 * op, plus any data specific to that op. For example, an OP_CONST op
29 * points to the pp_const() function and to an SV containing the constant
30 * value. When pp_const() is executed, its job is to push that SV onto the
31 * stack.
32 *
33 * OPs are mainly created by the newFOO() functions, which are mainly
34 * called from the parser (in perly.y) as the code is parsed. For example
35 * the Perl code $a + $b * $c would cause the equivalent of the following
36 * to be called (oversimplifying a bit):
37 *
38 * newBINOP(OP_ADD, flags,
39 * newSVREF($a),
40 * newBINOP(OP_MULTIPLY, flags, newSVREF($b), newSVREF($c))
41 * )
42 *
43 * Note that during the build of miniperl, a temporary copy of this file
44 * is made, called opmini.c.
45 */
ccfc67b7 46
61b743bb
DM
47/*
48Perl's compiler is essentially a 3-pass compiler with interleaved phases:
49
50 A bottom-up pass
51 A top-down pass
52 An execution-order pass
53
54The bottom-up pass is represented by all the "newOP" routines and
55the ck_ routines. The bottom-upness is actually driven by yacc.
56So at the point that a ck_ routine fires, we have no idea what the
57context is, either upward in the syntax tree, or either forward or
58backward in the execution order. (The bottom-up parser builds that
59part of the execution order it knows about, but if you follow the "next"
60links around, you'll find it's actually a closed loop through the
ef9da979 61top level node.)
61b743bb
DM
62
63Whenever the bottom-up parser gets to a node that supplies context to
64its components, it invokes that portion of the top-down pass that applies
65to that part of the subtree (and marks the top node as processed, so
66if a node further up supplies context, it doesn't have to take the
67plunge again). As a particular subcase of this, as the new node is
68built, it takes all the closed execution loops of its subcomponents
69and links them into a new closed loop for the higher level node. But
70it's still not the real execution order.
71
72The actual execution order is not known till we get a grammar reduction
73to a top-level unit like a subroutine or file that will be called by
74"name" rather than via a "next" pointer. At that point, we can call
75into peep() to do that code's portion of the 3rd pass. It has to be
76recursive, but it's recursive on basic blocks, not on tree nodes.
77*/
78
06e0342d 79/* To implement user lexical pragmas, there needs to be a way at run time to
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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
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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>
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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
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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
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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)
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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
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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
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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)))
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DM
214 {
215 o = (OP*)PerlMemShared_calloc(1, sz);
216 goto gotit;
217 }
8be227ab 218
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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
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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 615 (is_our ? padadd_OUR :
2502ffdf 616 PL_parser->in_my == KEY_state ? padadd_STATE : 0),
12bd6ede 617 PL_parser->in_my_stash,
3edf23ff 618 (is_our
133706a6 619 /* $_ is always in main::, even with our */
ef00320b
FC
620 ? (PL_curstash && !memEQs(name,len,"$_")
621 ? PL_curstash
622 : PL_defstash)
5c284bb0 623 : NULL
cca43f78 624 )
dd2155a4 625 );
a74073ad
DM
626 /* anon sub prototypes contains state vars should always be cloned,
627 * otherwise the state var would be shared between anon subs */
628
629 if (PL_parser->in_my == KEY_state && CvANON(PL_compcv))
630 CvCLONE_on(PL_compcv);
631
dd2155a4 632 return off;
79072805
LW
633}
634
c0b8aebd 635/*
dcccc8ff
KW
636=head1 Optree Manipulation Functions
637
c0b8aebd
FC
638=for apidoc alloccopstash
639
640Available only under threaded builds, this function allocates an entry in
641C<PL_stashpad> for the stash passed to it.
642
643=cut
644*/
645
d4d03940
FC
646#ifdef USE_ITHREADS
647PADOFFSET
1dc74fdb 648Perl_alloccopstash(pTHX_ HV *hv)
d4d03940
FC
649{
650 PADOFFSET off = 0, o = 1;
651 bool found_slot = FALSE;
652
1dc74fdb
FC
653 PERL_ARGS_ASSERT_ALLOCCOPSTASH;
654
655 if (PL_stashpad[PL_stashpadix] == hv) return PL_stashpadix;
d4d03940 656
1dc74fdb
FC
657 for (; o < PL_stashpadmax; ++o) {
658 if (PL_stashpad[o] == hv) return PL_stashpadix = o;
659 if (!PL_stashpad[o] || SvTYPE(PL_stashpad[o]) != SVt_PVHV)
d4d03940
FC
660 found_slot = TRUE, off = o;
661 }
662 if (!found_slot) {
1dc74fdb
FC
663 Renew(PL_stashpad, PL_stashpadmax + 10, HV *);
664 Zero(PL_stashpad + PL_stashpadmax, 10, HV *);
665 off = PL_stashpadmax;
666 PL_stashpadmax += 10;
d4d03940
FC
667 }
668
1dc74fdb 669 PL_stashpad[PL_stashpadix = off] = hv;
d4d03940
FC
670 return off;
671}
672#endif
673
d2c837a0
DM
674/* free the body of an op without examining its contents.
675 * Always use this rather than FreeOp directly */
676
4136a0f7 677static void
d2c837a0
DM
678S_op_destroy(pTHX_ OP *o)
679{
d2c837a0
DM
680 FreeOp(o);
681}
682
79072805
LW
683/* Destructor */
684
6e53b6ca
DD
685/*
686=for apidoc Am|void|op_free|OP *o
687
cc41839b
FC
688Free an op. Only use this when an op is no longer linked to from any
689optree.
6e53b6ca
DD
690
691=cut
692*/
693
79072805 694void
864dbfa3 695Perl_op_free(pTHX_ OP *o)
79072805 696{
27da23d5 697 dVAR;
acb36ea4 698 OPCODE type;
0997db6f
TC
699 SSize_t defer_ix = -1;
700 SSize_t defer_stack_alloc = 0;
701 OP **defer_stack = NULL;
79072805 702
0997db6f 703 do {
79072805 704
0997db6f
TC
705 /* Though ops may be freed twice, freeing the op after its slab is a
706 big no-no. */
707 assert(!o || !o->op_slabbed || OpSLAB(o)->opslab_refcnt != ~(size_t)0);
708 /* During the forced freeing of ops after compilation failure, kidops
709 may be freed before their parents. */
710 if (!o || o->op_type == OP_FREED)
711 continue;
d0c8136d 712
0997db6f 713 type = o->op_type;
d0c8136d 714
0997db6f
TC
715 /* an op should only ever acquire op_private flags that we know about.
716 * If this fails, you may need to fix something in regen/op_private */
717 if (o->op_ppaddr == PL_ppaddr[o->op_type]) {
718 assert(!(o->op_private & ~PL_op_private_valid[type]));
719 }
7934575e 720
0997db6f
TC
721 if (o->op_private & OPpREFCOUNTED) {
722 switch (type) {
723 case OP_LEAVESUB:
724 case OP_LEAVESUBLV:
725 case OP_LEAVEEVAL:
726 case OP_LEAVE:
727 case OP_SCOPE:
728 case OP_LEAVEWRITE:
729 {
730 PADOFFSET refcnt;
731 OP_REFCNT_LOCK;
732 refcnt = OpREFCNT_dec(o);
733 OP_REFCNT_UNLOCK;
734 if (refcnt) {
735 /* Need to find and remove any pattern match ops from the list
736 we maintain for reset(). */
737 find_and_forget_pmops(o);
738 continue;
739 }
740 }
741 break;
742 default:
743 break;
744 }
745 }
f37b8c3f 746
0997db6f
TC
747 /* Call the op_free hook if it has been set. Do it now so that it's called
748 * at the right time for refcounted ops, but still before all of the kids
749 * are freed. */
750 CALL_OPFREEHOOK(o);
751
752 if (o->op_flags & OPf_KIDS) {
753 OP *kid, *nextkid;
754 for (kid = cUNOPo->op_first; kid; kid = nextkid) {
755 nextkid = OP_SIBLING(kid); /* Get before next freeing kid */
756 if (!kid || kid->op_type == OP_FREED)
757 /* During the forced freeing of ops after
758 compilation failure, kidops may be freed before
759 their parents. */
760 continue;
761 if (!(kid->op_flags & OPf_KIDS))
762 /* If it has no kids, just free it now */
763 op_free(kid);
764 else
aa9d1253 765 DEFER_OP(kid);
0997db6f
TC
766 }
767 }
768 if (type == OP_NULL)
769 type = (OPCODE)o->op_targ;
acb36ea4 770
0997db6f
TC
771 if (o->op_slabbed)
772 Slab_to_rw(OpSLAB(o));
fc97af9c 773
0997db6f
TC
774 /* COP* is not cleared by op_clear() so that we may track line
775 * numbers etc even after null() */
776 if (type == OP_NEXTSTATE || type == OP_DBSTATE) {
777 cop_free((COP*)o);
778 }
acb36ea4 779
0997db6f
TC
780 op_clear(o);
781 FreeOp(o);
4d494880 782#ifdef DEBUG_LEAKING_SCALARS
0997db6f
TC
783 if (PL_op == o)
784 PL_op = NULL;
4d494880 785#endif
aa9d1253 786 } while ( (o = POP_DEFERRED_OP()) );
0997db6f
TC
787
788 Safefree(defer_stack);
acb36ea4 789}
79072805 790
93c66552
DM
791void
792Perl_op_clear(pTHX_ OP *o)
acb36ea4 793{
13137afc 794
27da23d5 795 dVAR;
7918f24d
NC
796
797 PERL_ARGS_ASSERT_OP_CLEAR;
798
11343788 799 switch (o->op_type) {
acb36ea4 800 case OP_NULL: /* Was holding old type, if any. */
c67159e1 801 /* FALLTHROUGH */
4d193d44 802 case OP_ENTERTRY:
acb36ea4 803 case OP_ENTEREVAL: /* Was holding hints. */
acb36ea4 804 o->op_targ = 0;
a0d0e21e 805 break;
a6006777 806 default:
ac4c12e7 807 if (!(o->op_flags & OPf_REF)
ef69c8fc 808 || (PL_check[o->op_type] != Perl_ck_ftst))
a6006777 809 break;
924ba076 810 /* FALLTHROUGH */
463ee0b2 811 case OP_GVSV:
79072805 812 case OP_GV:
a6006777 813 case OP_AELEMFAST:
93bad3fd 814 {
f7461760
Z
815 GV *gv = (o->op_type == OP_GV || o->op_type == OP_GVSV)
816#ifdef USE_ITHREADS
817 && PL_curpad
818#endif
819 ? cGVOPo_gv : NULL;
b327b36f
NC
820 /* It's possible during global destruction that the GV is freed
821 before the optree. Whilst the SvREFCNT_inc is happy to bump from
822 0 to 1 on a freed SV, the corresponding SvREFCNT_dec from 1 to 0
823 will trigger an assertion failure, because the entry to sv_clear
824 checks that the scalar is not already freed. A check of for
825 !SvIS_FREED(gv) turns out to be invalid, because during global
826 destruction the reference count can be forced down to zero
827 (with SVf_BREAK set). In which case raising to 1 and then
828 dropping to 0 triggers cleanup before it should happen. I
829 *think* that this might actually be a general, systematic,
830 weakness of the whole idea of SVf_BREAK, in that code *is*
831 allowed to raise and lower references during global destruction,
832 so any *valid* code that happens to do this during global
833 destruction might well trigger premature cleanup. */
834 bool still_valid = gv && SvREFCNT(gv);
835
836 if (still_valid)
837 SvREFCNT_inc_simple_void(gv);
350de78d 838#ifdef USE_ITHREADS
6a077020 839 if (cPADOPo->op_padix > 0) {
6a077020
DM
840 pad_swipe(cPADOPo->op_padix, TRUE);
841 cPADOPo->op_padix = 0;
842 }
350de78d 843#else
6a077020 844 SvREFCNT_dec(cSVOPo->op_sv);
a0714e2c 845 cSVOPo->op_sv = NULL;
350de78d 846#endif
b327b36f 847 if (still_valid) {
f7461760 848 int try_downgrade = SvREFCNT(gv) == 2;
fc2b2dca 849 SvREFCNT_dec_NN(gv);
f7461760
Z
850 if (try_downgrade)
851 gv_try_downgrade(gv);
852 }
6a077020 853 }
79072805 854 break;
810bd8b7 855 case OP_METHOD_REDIR:
856 case OP_METHOD_REDIR_SUPER:
857#ifdef USE_ITHREADS
858 if (cMETHOPx(o)->op_rclass_targ) {
859 pad_swipe(cMETHOPx(o)->op_rclass_targ, 1);
860 cMETHOPx(o)->op_rclass_targ = 0;
861 }
862#else
863 SvREFCNT_dec(cMETHOPx(o)->op_rclass_sv);
864 cMETHOPx(o)->op_rclass_sv = NULL;
865#endif
a1ae71d2 866 case OP_METHOD_NAMED:
7d6c333c 867 case OP_METHOD_SUPER:
b46e009d 868 SvREFCNT_dec(cMETHOPx(o)->op_u.op_meth_sv);
869 cMETHOPx(o)->op_u.op_meth_sv = NULL;
870#ifdef USE_ITHREADS
871 if (o->op_targ) {
872 pad_swipe(o->op_targ, 1);
873 o->op_targ = 0;
874 }
875#endif
876 break;
79072805 877 case OP_CONST:
996c9baa 878 case OP_HINTSEVAL:
11343788 879 SvREFCNT_dec(cSVOPo->op_sv);
a0714e2c 880 cSVOPo->op_sv = NULL;
3b1c21fa
AB
881#ifdef USE_ITHREADS
882 /** Bug #15654
883 Even if op_clear does a pad_free for the target of the op,
6a077020 884 pad_free doesn't actually remove the sv that exists in the pad;
3b1c21fa
AB
885 instead it lives on. This results in that it could be reused as
886 a target later on when the pad was reallocated.
887 **/
888 if(o->op_targ) {
889 pad_swipe(o->op_targ,1);
890 o->op_targ = 0;
891 }
892#endif
79072805 893 break;
c9df4fda 894 case OP_DUMP:
748a9306
LW
895 case OP_GOTO:
896 case OP_NEXT:
897 case OP_LAST:
898 case OP_REDO:
11343788 899 if (o->op_flags & (OPf_SPECIAL|OPf_STACKED|OPf_KIDS))
748a9306 900 break;
924ba076 901 /* FALLTHROUGH */
a0d0e21e 902 case OP_TRANS:
bb16bae8 903 case OP_TRANSR:
acb36ea4 904 if (o->op_private & (OPpTRANS_FROM_UTF|OPpTRANS_TO_UTF)) {
99a1d0d1 905 assert(o->op_type == OP_TRANS || o->op_type == OP_TRANSR);
043e41b8
DM
906#ifdef USE_ITHREADS
907 if (cPADOPo->op_padix > 0) {
908 pad_swipe(cPADOPo->op_padix, TRUE);
909 cPADOPo->op_padix = 0;
910 }
911#else
a0ed51b3 912 SvREFCNT_dec(cSVOPo->op_sv);
a0714e2c 913 cSVOPo->op_sv = NULL;
043e41b8 914#endif
acb36ea4
GS
915 }
916 else {
ea71c68d 917 PerlMemShared_free(cPVOPo->op_pv);
bd61b366 918 cPVOPo->op_pv = NULL;
acb36ea4 919 }
a0d0e21e
LW
920 break;
921 case OP_SUBST:
20e98b0f 922 op_free(cPMOPo->op_pmreplrootu.op_pmreplroot);
971a9dd3 923 goto clear_pmop;
748a9306 924 case OP_PUSHRE:
971a9dd3 925#ifdef USE_ITHREADS
20e98b0f 926 if (cPMOPo->op_pmreplrootu.op_pmtargetoff) {
20e98b0f 927 pad_swipe(cPMOPo->op_pmreplrootu.op_pmtargetoff, TRUE);
971a9dd3
GS
928 }
929#else
ad64d0ec 930 SvREFCNT_dec(MUTABLE_SV(cPMOPo->op_pmreplrootu.op_pmtargetgv));
971a9dd3 931#endif
924ba076 932 /* FALLTHROUGH */
a0d0e21e 933 case OP_MATCH:
8782bef2 934 case OP_QR:
971a9dd3 935clear_pmop:
867940b8
DM
936 if (!(cPMOPo->op_pmflags & PMf_CODELIST_PRIVATE))
937 op_free(cPMOPo->op_code_list);
68e2671b 938 cPMOPo->op_code_list = NULL;
23083432 939 forget_pmop(cPMOPo);
20e98b0f 940 cPMOPo->op_pmreplrootu.op_pmreplroot = NULL;
9cddf794
NC
941 /* we use the same protection as the "SAFE" version of the PM_ macros
942 * here since sv_clean_all might release some PMOPs
5f8cb046
DM
943 * after PL_regex_padav has been cleared
944 * and the clearing of PL_regex_padav needs to
945 * happen before sv_clean_all
946 */
13137afc
AB
947#ifdef USE_ITHREADS
948 if(PL_regex_pad) { /* We could be in destruction */
402d2eb1 949 const IV offset = (cPMOPo)->op_pmoffset;
9cddf794 950 ReREFCNT_dec(PM_GETRE(cPMOPo));
402d2eb1
NC
951 PL_regex_pad[offset] = &PL_sv_undef;
952 sv_catpvn_nomg(PL_regex_pad[0], (const char *)&offset,
953 sizeof(offset));
13137afc 954 }
9cddf794
NC
955#else
956 ReREFCNT_dec(PM_GETRE(cPMOPo));
957 PM_SETRE(cPMOPo, NULL);
1eb1540c 958#endif
13137afc 959
a0d0e21e 960 break;
79072805
LW
961 }
962
743e66e6 963 if (o->op_targ > 0) {
11343788 964 pad_free(o->op_targ);
743e66e6
GS
965 o->op_targ = 0;
966 }
79072805
LW
967}
968
76e3520e 969STATIC void
3eb57f73
HS
970S_cop_free(pTHX_ COP* cop)
971{
7918f24d
NC
972 PERL_ARGS_ASSERT_COP_FREE;
973
05ec9bb3 974 CopFILE_free(cop);
0453d815 975 if (! specialWARN(cop->cop_warnings))
72dc9ed5 976 PerlMemShared_free(cop->cop_warnings);
20439bc7 977 cophh_free(CopHINTHASH_get(cop));
515abc43
FC
978 if (PL_curcop == cop)
979 PL_curcop = NULL;
3eb57f73
HS
980}
981
c2b1997a 982STATIC void
c4bd3ae5 983S_forget_pmop(pTHX_ PMOP *const o
c4bd3ae5 984 )
c2b1997a
NC
985{
986 HV * const pmstash = PmopSTASH(o);
7918f24d
NC
987
988 PERL_ARGS_ASSERT_FORGET_PMOP;
989
e39a6381 990 if (pmstash && !SvIS_FREED(pmstash) && SvMAGICAL(pmstash)) {
ad64d0ec 991 MAGIC * const mg = mg_find((const SV *)pmstash, PERL_MAGIC_symtab);
c2b1997a
NC
992 if (mg) {
993 PMOP **const array = (PMOP**) mg->mg_ptr;
994 U32 count = mg->mg_len / sizeof(PMOP**);
995 U32 i = count;
996
997 while (i--) {
998 if (array[i] == o) {
999 /* Found it. Move the entry at the end to overwrite it. */
1000 array[i] = array[--count];
1001 mg->mg_len = count * sizeof(PMOP**);
1002 /* Could realloc smaller at this point always, but probably
1003 not worth it. Probably worth free()ing if we're the
1004 last. */
1005 if(!count) {
1006 Safefree(mg->mg_ptr);
1007 mg->mg_ptr = NULL;
1008 }
1009 break;
1010 }
1011 }
1012 }
1013 }
1cdf7faf
NC
1014 if (PL_curpm == o)
1015 PL_curpm = NULL;
c2b1997a
NC
1016}
1017
bfd0ff22
NC
1018STATIC void
1019S_find_and_forget_pmops(pTHX_ OP *o)
1020{
7918f24d
NC
1021 PERL_ARGS_ASSERT_FIND_AND_FORGET_PMOPS;
1022
bfd0ff22
NC
1023 if (o->op_flags & OPf_KIDS) {
1024 OP *kid = cUNOPo->op_first;
1025 while (kid) {
1026 switch (kid->op_type) {
1027 case OP_SUBST:
1028 case OP_PUSHRE:
1029 case OP_MATCH:
1030 case OP_QR:
23083432 1031 forget_pmop((PMOP*)kid);
bfd0ff22
NC
1032 }
1033 find_and_forget_pmops(kid);
1ed44841 1034 kid = OP_SIBLING(kid);
bfd0ff22
NC
1035 }
1036 }
1037}
1038
6e53b6ca
DD
1039/*
1040=for apidoc Am|void|op_null|OP *o
1041
1042Neutralizes an op when it is no longer needed, but is still linked to from
1043other ops.
1044
1045=cut
1046*/
1047
93c66552
DM
1048void
1049Perl_op_null(pTHX_ OP *o)
8990e307 1050{
27da23d5 1051 dVAR;
7918f24d
NC
1052
1053 PERL_ARGS_ASSERT_OP_NULL;
1054
acb36ea4
GS
1055 if (o->op_type == OP_NULL)
1056 return;
b5bbe64a 1057 op_clear(o);
11343788 1058 o->op_targ = o->op_type;
10884df9 1059 CHANGE_TYPE(o, OP_NULL);
8990e307
LW
1060}
1061
4026c95a
SH
1062void
1063Perl_op_refcnt_lock(pTHX)
1064{
20b7effb 1065#ifdef USE_ITHREADS
27da23d5 1066 dVAR;
20b7effb 1067#endif
96a5add6 1068 PERL_UNUSED_CONTEXT;
4026c95a
SH
1069 OP_REFCNT_LOCK;
1070}
1071
1072void
1073Perl_op_refcnt_unlock(pTHX)
1074{
20b7effb 1075#ifdef USE_ITHREADS
27da23d5 1076 dVAR;
20b7effb 1077#endif
96a5add6 1078 PERL_UNUSED_CONTEXT;
4026c95a
SH
1079 OP_REFCNT_UNLOCK;
1080}
1081
3253bf85
DM
1082
1083/*
1084=for apidoc op_sibling_splice
1085
1086A general function for editing the structure of an existing chain of
7e234f81 1087op_sibling nodes. By analogy with the perl-level splice() function, allows
3253bf85
DM
1088you to delete zero or more sequential nodes, replacing them with zero or
1089more different nodes. Performs the necessary op_first/op_last
29e61fd9 1090housekeeping on the parent node and op_sibling manipulation on the
7e234f81 1091children. The last deleted node will be marked as as the last node by
8ae26bff 1092updating the op_sibling or op_lastsib field as appropriate.
3253bf85
DM
1093
1094Note that op_next is not manipulated, and nodes are not freed; that is the
7e234f81 1095responsibility of the caller. It also won't create a new list op for an
8ae26bff 1096empty list etc; use higher-level functions like op_append_elem() for that.
3253bf85
DM
1097
1098parent is the parent node of the sibling chain.
1099
7e234f81
FC
1100start is the node preceding the first node to be spliced. Node(s)
1101following it will be deleted, and ops will be inserted after it. If it is
3253bf85
DM
1102NULL, the first node onwards is deleted, and nodes are inserted at the
1103beginning.
1104
7e234f81 1105del_count is the number of nodes to delete. If zero, no nodes are deleted.
3253bf85
DM
1106If -1 or greater than or equal to the number of remaining kids, all
1107remaining kids are deleted.
1108
1109insert is the first of a chain of nodes to be inserted in place of the nodes.
1110If NULL, no nodes are inserted.
1111
8ae26bff 1112The head of the chain of deleted ops is returned, or NULL if no ops were
3253bf85
DM
1113deleted.
1114
1115For example:
1116
1117 action before after returns
1118 ------ ----- ----- -------
1119
1120 P P
8ae26bff
DM
1121 splice(P, A, 2, X-Y-Z) | | B-C
1122 A-B-C-D A-X-Y-Z-D
3253bf85
DM
1123
1124 P P
1125 splice(P, NULL, 1, X-Y) | | A
1126 A-B-C-D X-Y-B-C-D
1127
1128 P P
8ae26bff
DM
1129 splice(P, NULL, 3, NULL) | | A-B-C
1130 A-B-C-D D
3253bf85
DM
1131
1132 P P
1133 splice(P, B, 0, X-Y) | | NULL
1134 A-B-C-D A-B-X-Y-C-D
1135
1136=cut
1137*/
1138
1139OP *
8ae26bff 1140Perl_op_sibling_splice(OP *parent, OP *start, int del_count, OP* insert)
3253bf85 1141{
3253bf85
DM
1142 OP *first = start ? OP_SIBLING(start) : cLISTOPx(parent)->op_first;
1143 OP *rest;
1144 OP *last_del = NULL;
1145 OP *last_ins = NULL;
1146
1147 PERL_ARGS_ASSERT_OP_SIBLING_SPLICE;
1148
1149 assert(del_count >= -1);
1150
1151 if (del_count && first) {
1152 last_del = first;
1153 while (--del_count && OP_HAS_SIBLING(last_del))
1154 last_del = OP_SIBLING(last_del);
1155 rest = OP_SIBLING(last_del);
1156 OP_SIBLING_set(last_del, NULL);
29e61fd9 1157 last_del->op_lastsib = 1;
3253bf85
DM
1158 }
1159 else
1160 rest = first;
1161
1162 if (insert) {
1163 last_ins = insert;
1164 while (OP_HAS_SIBLING(last_ins))
1165 last_ins = OP_SIBLING(last_ins);
1166 OP_SIBLING_set(last_ins, rest);
29e61fd9 1167 last_ins->op_lastsib = rest ? 0 : 1;
3253bf85
DM
1168 }
1169 else
1170 insert = rest;
1171
29e61fd9 1172 if (start) {
3253bf85 1173 OP_SIBLING_set(start, insert);
29e61fd9
DM
1174 start->op_lastsib = insert ? 0 : 1;
1175 }
3253bf85
DM
1176 else
1177 cLISTOPx(parent)->op_first = insert;
1178
1179 if (!rest) {
29e61fd9 1180 /* update op_last etc */
3253bf85 1181 U32 type = parent->op_type;
29e61fd9 1182 OP *lastop;
3253bf85
DM
1183
1184 if (type == OP_NULL)
1185 type = parent->op_targ;
1186 type = PL_opargs[type] & OA_CLASS_MASK;
1187
29e61fd9 1188 lastop = last_ins ? last_ins : start ? start : NULL;
3253bf85
DM
1189 if ( type == OA_BINOP
1190 || type == OA_LISTOP
1191 || type == OA_PMOP
1192 || type == OA_LOOP
1193 )
29e61fd9
DM
1194 cLISTOPx(parent)->op_last = lastop;
1195
1196 if (lastop) {
1197 lastop->op_lastsib = 1;
1198#ifdef PERL_OP_PARENT
1199 lastop->op_sibling = parent;
1200#endif
1201 }
3253bf85
DM
1202 }
1203 return last_del ? first : NULL;
1204}
1205
29e61fd9
DM
1206/*
1207=for apidoc op_parent
1208
7e234f81 1209returns the parent OP of o, if it has a parent. Returns NULL otherwise.
29e61fd9
DM
1210(Currently perl must be built with C<-DPERL_OP_PARENT> for this feature to
1211work.
1212
1213=cut
1214*/
1215
1216OP *
8ae26bff 1217Perl_op_parent(OP *o)
29e61fd9
DM
1218{
1219 PERL_ARGS_ASSERT_OP_PARENT;
1220#ifdef PERL_OP_PARENT
1221 while (OP_HAS_SIBLING(o))
1222 o = OP_SIBLING(o);
1223 return o->op_sibling;
1224#else
1225 PERL_UNUSED_ARG(o);
1226 return NULL;
1227#endif
1228}
1229
3253bf85
DM
1230
1231/* replace the sibling following start with a new UNOP, which becomes
1232 * the parent of the original sibling; e.g.
1233 *
1234 * op_sibling_newUNOP(P, A, unop-args...)
1235 *
1236 * P P
1237 * | becomes |
1238 * A-B-C A-U-C
1239 * |
1240 * B
1241 *
1242 * where U is the new UNOP.
1243 *
1244 * parent and start args are the same as for op_sibling_splice();
1245 * type and flags args are as newUNOP().
1246 *
1247 * Returns the new UNOP.
1248 */
1249
1250OP *
1251S_op_sibling_newUNOP(pTHX_ OP *parent, OP *start, I32 type, I32 flags)
1252{
1253 OP *kid, *newop;
1254
1255 kid = op_sibling_splice(parent, start, 1, NULL);
1256 newop = newUNOP(type, flags, kid);
1257 op_sibling_splice(parent, start, 0, newop);
1258 return newop;
1259}
1260
1261
1262/* lowest-level newLOGOP-style function - just allocates and populates
1263 * the struct. Higher-level stuff should be done by S_new_logop() /
1264 * newLOGOP(). This function exists mainly to avoid op_first assignment
1265 * being spread throughout this file.
1266 */
1267
1268LOGOP *
1269S_alloc_LOGOP(pTHX_ I32 type, OP *first, OP* other)
1270{
1e8db68a 1271 dVAR;
3253bf85 1272 LOGOP *logop;
29e61fd9 1273 OP *kid = first;
3253bf85 1274 NewOp(1101, logop, 1, LOGOP);
ddacf109 1275 CHANGE_TYPE(logop, type);
3253bf85
DM
1276 logop->op_first = first;
1277 logop->op_other = other;
1278 logop->op_flags = OPf_KIDS;
29e61fd9
DM
1279 while (kid && OP_HAS_SIBLING(kid))
1280 kid = OP_SIBLING(kid);
1281 if (kid) {
1282 kid->op_lastsib = 1;
1283#ifdef PERL_OP_PARENT
1284 kid->op_sibling = (OP*)logop;
1285#endif
1286 }
3253bf85
DM
1287 return logop;
1288}
1289
1290
79072805
LW
1291/* Contextualizers */
1292
d9088386
Z
1293/*
1294=for apidoc Am|OP *|op_contextualize|OP *o|I32 context
1295
1296Applies a syntactic context to an op tree representing an expression.
1297I<o> is the op tree, and I<context> must be C<G_SCALAR>, C<G_ARRAY>,
1298or C<G_VOID> to specify the context to apply. The modified op tree
1299is returned.
1300
1301=cut
1302*/
1303
1304OP *
1305Perl_op_contextualize(pTHX_ OP *o, I32 context)
1306{
1307 PERL_ARGS_ASSERT_OP_CONTEXTUALIZE;
1308 switch (context) {
1309 case G_SCALAR: return scalar(o);
1310 case G_ARRAY: return list(o);
1311 case G_VOID: return scalarvoid(o);
1312 default:
5637ef5b
NC
1313 Perl_croak(aTHX_ "panic: op_contextualize bad context %ld",
1314 (long) context);
d9088386
Z
1315 }
1316}
1317
5983a79d 1318/*
79072805 1319
5983a79d 1320=for apidoc Am|OP*|op_linklist|OP *o
72d33970 1321This function is the implementation of the L</LINKLIST> macro. It should
5983a79d
BM
1322not be called directly.
1323
1324=cut
1325*/
1326
1327OP *
1328Perl_op_linklist(pTHX_ OP *o)
79072805 1329{
3edf23ff 1330 OP *first;
79072805 1331
5983a79d 1332 PERL_ARGS_ASSERT_OP_LINKLIST;
7918f24d 1333
11343788
MB
1334 if (o->op_next)
1335 return o->op_next;
79072805
LW
1336
1337 /* establish postfix order */
3edf23ff
AL
1338 first = cUNOPo->op_first;
1339 if (first) {
eb578fdb 1340 OP *kid;
3edf23ff
AL
1341 o->op_next = LINKLIST(first);
1342 kid = first;
1343 for (;;) {
29e61fd9
DM
1344 OP *sibl = OP_SIBLING(kid);
1345 if (sibl) {
1346 kid->op_next = LINKLIST(sibl);
1347 kid = sibl;
3edf23ff 1348 } else {
11343788 1349 kid->op_next = o;
3edf23ff
AL
1350 break;
1351 }
79072805
LW
1352 }
1353 }
1354 else
11343788 1355 o->op_next = o;
79072805 1356
11343788 1357 return o->op_next;
79072805
LW
1358}
1359
1f676739 1360static OP *
2dd5337b 1361S_scalarkids(pTHX_ OP *o)
79072805 1362{
11343788 1363 if (o && o->op_flags & OPf_KIDS) {
bfed75c6 1364 OP *kid;
1ed44841 1365 for (kid = cLISTOPo->op_first; kid; kid = OP_SIBLING(kid))
79072805
LW
1366 scalar(kid);
1367 }
11343788 1368 return o;
79072805
LW
1369}
1370
76e3520e 1371STATIC OP *
cea2e8a9 1372S_scalarboolean(pTHX_ OP *o)
8990e307 1373{
7918f24d
NC
1374 PERL_ARGS_ASSERT_SCALARBOOLEAN;
1375
6b7c6d95
FC
1376 if (o->op_type == OP_SASSIGN && cBINOPo->op_first->op_type == OP_CONST
1377 && !(cBINOPo->op_first->op_flags & OPf_SPECIAL)) {
d008e5eb 1378 if (ckWARN(WARN_SYNTAX)) {
6867be6d 1379 const line_t oldline = CopLINE(PL_curcop);
a0d0e21e 1380
2b7cddde
NC
1381 if (PL_parser && PL_parser->copline != NOLINE) {
1382 /* This ensures that warnings are reported at the first line
1383 of the conditional, not the last. */
53a7735b 1384 CopLINE_set(PL_curcop, PL_parser->copline);
2b7cddde 1385 }
9014280d 1386 Perl_warner(aTHX_ packWARN(WARN_SYNTAX), "Found = in conditional, should be ==");
57843af0 1387 CopLINE_set(PL_curcop, oldline);
d008e5eb 1388 }
a0d0e21e 1389 }
11343788 1390 return scalar(o);
8990e307
LW
1391}
1392
0920b7fa
FC
1393static SV *
1394S_op_varname(pTHX_ const OP *o)
1395{
1396 assert(o);
1397 assert(o->op_type == OP_PADAV || o->op_type == OP_RV2AV ||
1398 o->op_type == OP_PADHV || o->op_type == OP_RV2HV);
1399 {
1400 const char funny = o->op_type == OP_PADAV
1401 || o->op_type == OP_RV2AV ? '@' : '%';
1402 if (o->op_type == OP_RV2AV || o->op_type == OP_RV2HV) {
1403 GV *gv;
1404 if (cUNOPo->op_first->op_type != OP_GV
1405 || !(gv = cGVOPx_gv(cUNOPo->op_first)))
1406 return NULL;
1407 return varname(gv, funny, 0, NULL, 0, 1);
1408 }
1409 return
1410 varname(MUTABLE_GV(PL_compcv), funny, o->op_targ, NULL, 0, 1);
1411 }
1412}
1413
429a2555 1414static void
2186f873
FC
1415S_op_pretty(pTHX_ const OP *o, SV **retsv, const char **retpv)
1416{ /* or not so pretty :-) */
2186f873
FC
1417 if (o->op_type == OP_CONST) {
1418 *retsv = cSVOPo_sv;
1419 if (SvPOK(*retsv)) {
1420 SV *sv = *retsv;
1421 *retsv = sv_newmortal();
1422 pv_pretty(*retsv, SvPVX_const(sv), SvCUR(sv), 32, NULL, NULL,
1423 PERL_PV_PRETTY_DUMP |PERL_PV_ESCAPE_UNI_DETECT);
1424 }
1425 else if (!SvOK(*retsv))
1426 *retpv = "undef";
1427 }
1428 else *retpv = "...";
1429}
1430
1431static void
429a2555
FC
1432S_scalar_slice_warning(pTHX_ const OP *o)
1433{
1434 OP *kid;
1435 const char lbrack =
2186f873 1436 o->op_type == OP_HSLICE ? '{' : '[';
429a2555 1437 const char rbrack =
2186f873 1438 o->op_type == OP_HSLICE ? '}' : ']';
429a2555 1439 SV *name;
32e9ec8f 1440 SV *keysv = NULL; /* just to silence compiler warnings */
429a2555
FC
1441 const char *key = NULL;
1442
1443 if (!(o->op_private & OPpSLICEWARNING))
1444 return;
1445 if (PL_parser && PL_parser->error_count)
1446 /* This warning can be nonsensical when there is a syntax error. */
1447 return;
1448
1449 kid = cLISTOPo->op_first;
1ed44841 1450 kid = OP_SIBLING(kid); /* get past pushmark */
429a2555
FC
1451 /* weed out false positives: any ops that can return lists */
1452 switch (kid->op_type) {
1453 case OP_BACKTICK:
1454 case OP_GLOB:
1455 case OP_READLINE:
1456 case OP_MATCH:
1457 case OP_RV2AV:
1458 case OP_EACH:
1459 case OP_VALUES:
1460 case OP_KEYS:
1461 case OP_SPLIT:
1462 case OP_LIST:
1463 case OP_SORT:
1464 case OP_REVERSE:
1465 case OP_ENTERSUB:
1466 case OP_CALLER:
1467 case OP_LSTAT:
1468 case OP_STAT:
1469 case OP_READDIR:
1470 case OP_SYSTEM:
1471 case OP_TMS:
1472 case OP_LOCALTIME:
1473 case OP_GMTIME:
1474 case OP_ENTEREVAL:
1475 case OP_REACH:
1476 case OP_RKEYS:
1477 case OP_RVALUES:
1478 return;
1479 }
7d3c8a68
SM
1480
1481 /* Don't warn if we have a nulled list either. */
1482 if (kid->op_type == OP_NULL && kid->op_targ == OP_LIST)
1483 return;
1484
1ed44841
DM
1485 assert(OP_SIBLING(kid));
1486 name = S_op_varname(aTHX_ OP_SIBLING(kid));
429a2555
FC
1487 if (!name) /* XS module fiddling with the op tree */
1488 return;
2186f873 1489 S_op_pretty(aTHX_ kid, &keysv, &key);
429a2555
FC
1490 assert(SvPOK(name));
1491 sv_chop(name,SvPVX(name)+1);
1492 if (key)
2186f873 1493 /* diag_listed_as: Scalar value @%s[%s] better written as $%s[%s] */
429a2555 1494 Perl_warner(aTHX_ packWARN(WARN_SYNTAX),
2186f873 1495 "Scalar value @%"SVf"%c%s%c better written as $%"SVf
429a2555 1496 "%c%s%c",
2186f873 1497 SVfARG(name), lbrack, key, rbrack, SVfARG(name),
429a2555
FC
1498 lbrack, key, rbrack);
1499 else
2186f873 1500 /* diag_listed_as: Scalar value @%s[%s] better written as $%s[%s] */
429a2555 1501 Perl_warner(aTHX_ packWARN(WARN_SYNTAX),
2186f873 1502 "Scalar value @%"SVf"%c%"SVf"%c better written as $%"
429a2555 1503 SVf"%c%"SVf"%c",
c1f6cd39
BF
1504 SVfARG(name), lbrack, SVfARG(keysv), rbrack,
1505 SVfARG(name), lbrack, SVfARG(keysv), rbrack);
429a2555
FC
1506}
1507
8990e307 1508OP *
864dbfa3 1509Perl_scalar(pTHX_ OP *o)
79072805
LW
1510{
1511 OP *kid;
1512
a0d0e21e 1513 /* assumes no premature commitment */
13765c85
DM
1514 if (!o || (PL_parser && PL_parser->error_count)
1515 || (o->op_flags & OPf_WANT)
5dc0d613 1516 || o->op_type == OP_RETURN)
7e363e51 1517 {
11343788 1518 return o;
7e363e51 1519 }
79072805 1520
5dc0d613 1521 o->op_flags = (o->op_flags & ~OPf_WANT) | OPf_WANT_SCALAR;
79072805 1522
11343788 1523 switch (o->op_type) {
79072805 1524 case OP_REPEAT:
11343788 1525 scalar(cBINOPo->op_first);
82e4f303
FC
1526 if (o->op_private & OPpREPEAT_DOLIST) {
1527 kid = cLISTOPx(cUNOPo->op_first)->op_first;
1528 assert(kid->op_type == OP_PUSHMARK);
1529 if (OP_HAS_SIBLING(kid) && !OP_HAS_SIBLING(OP_SIBLING(kid))) {
1530 op_null(cLISTOPx(cUNOPo->op_first)->op_first);
1531 o->op_private &=~ OPpREPEAT_DOLIST;
1532 }
1533 }
8990e307 1534 break;
79072805
LW
1535 case OP_OR:
1536 case OP_AND:
1537 case OP_COND_EXPR:
1ed44841 1538 for (kid = OP_SIBLING(cUNOPo->op_first); kid; kid = OP_SIBLING(kid))
8990e307 1539 scalar(kid);
79072805 1540 break;
924ba076 1541 /* FALLTHROUGH */
a6d8037e 1542 case OP_SPLIT:
79072805 1543 case OP_MATCH:
8782bef2 1544 case OP_QR:
79072805
LW
1545 case OP_SUBST:
1546 case OP_NULL:
8990e307 1547 default:
11343788 1548 if (o->op_flags & OPf_KIDS) {
1ed44841 1549 for (kid = cUNOPo->op_first; kid; kid = OP_SIBLING(kid))
8990e307
LW
1550 scalar(kid);
1551 }
79072805
LW
1552 break;
1553 case OP_LEAVE:
1554 case OP_LEAVETRY:
5dc0d613 1555 kid = cLISTOPo->op_first;
54310121 1556 scalar(kid);
1ed44841 1557 kid = OP_SIBLING(kid);
25b991bf
VP
1558 do_kids:
1559 while (kid) {
1ed44841 1560 OP *sib = OP_SIBLING(kid);
34b54951
FC
1561 if (sib && kid->op_type != OP_LEAVEWHEN
1562 && ( OP_HAS_SIBLING(sib) || sib->op_type != OP_NULL
1563 || ( sib->op_targ != OP_NEXTSTATE
1564 && sib->op_targ != OP_DBSTATE )))
c08f093b
VP
1565 scalarvoid(kid);
1566 else
54310121 1567 scalar(kid);
25b991bf 1568 kid = sib;
54310121 1569 }
11206fdd 1570 PL_curcop = &PL_compiling;
54310121 1571 break;
748a9306 1572 case OP_SCOPE:
79072805 1573 case OP_LINESEQ:
8990e307 1574 case OP_LIST:
25b991bf
VP
1575 kid = cLISTOPo->op_first;
1576 goto do_kids;
a801c63c 1577 case OP_SORT:
a2a5de95 1578 Perl_ck_warner(aTHX_ packWARN(WARN_VOID), "Useless use of sort in scalar context");
553e7bb0 1579 break;
95a31aad
FC
1580 case OP_KVHSLICE:
1581 case OP_KVASLICE:
2186f873
FC
1582 {
1583 /* Warn about scalar context */
1584 const char lbrack = o->op_type == OP_KVHSLICE ? '{' : '[';
1585 const char rbrack = o->op_type == OP_KVHSLICE ? '}' : ']';
1586 SV *name;
1587 SV *keysv;
1588 const char *key = NULL;
1589
1590 /* This warning can be nonsensical when there is a syntax error. */
1591 if (PL_parser && PL_parser->error_count)
1592 break;
1593
1594 if (!ckWARN(WARN_SYNTAX)) break;
1595
1596 kid = cLISTOPo->op_first;
1ed44841
DM
1597 kid = OP_SIBLING(kid); /* get past pushmark */
1598 assert(OP_SIBLING(kid));
1599 name = S_op_varname(aTHX_ OP_SIBLING(kid));
2186f873
FC
1600 if (!name) /* XS module fiddling with the op tree */
1601 break;
1602 S_op_pretty(aTHX_ kid, &keysv, &key);
1603 assert(SvPOK(name));
1604 sv_chop(name,SvPVX(name)+1);
1605 if (key)
1606 /* diag_listed_as: %%s[%s] in scalar context better written as $%s[%s] */
1607 Perl_warner(aTHX_ packWARN(WARN_SYNTAX),
1608 "%%%"SVf"%c%s%c in scalar context better written "
1609 "as $%"SVf"%c%s%c",
1610 SVfARG(name), lbrack, key, rbrack, SVfARG(name),
1611 lbrack, key, rbrack);
1612 else
1613 /* diag_listed_as: %%s[%s] in scalar context better written as $%s[%s] */
1614 Perl_warner(aTHX_ packWARN(WARN_SYNTAX),
1615 "%%%"SVf"%c%"SVf"%c in scalar context better "
1616 "written as $%"SVf"%c%"SVf"%c",
c1f6cd39
BF
1617 SVfARG(name), lbrack, SVfARG(keysv), rbrack,
1618 SVfARG(name), lbrack, SVfARG(keysv), rbrack);
2186f873 1619 }
79072805 1620 }
11343788 1621 return o;
79072805
LW
1622}
1623
1624OP *
aa9d1253 1625Perl_scalarvoid(pTHX_ OP *arg)
79072805 1626{
27da23d5 1627 dVAR;
79072805 1628 OP *kid;
8990e307 1629 SV* sv;
2ebea0a1 1630 U8 want;
aa9d1253
TC
1631 SSize_t defer_stack_alloc = 0;
1632 SSize_t defer_ix = -1;
1633 OP **defer_stack = NULL;
1634 OP *o = arg;
2ebea0a1 1635
7918f24d
NC
1636 PERL_ARGS_ASSERT_SCALARVOID;
1637
aa9d1253
TC
1638 do {
1639 SV *useless_sv = NULL;
1640 const char* useless = NULL;
1641
26f0e7d5
TC
1642 if (o->op_type == OP_NEXTSTATE
1643 || o->op_type == OP_DBSTATE
1644 || (o->op_type == OP_NULL && (o->op_targ == OP_NEXTSTATE
1645 || o->op_targ == OP_DBSTATE)))
1646 PL_curcop = (COP*)o; /* for warning below */
1647
1648 /* assumes no premature commitment */
1649 want = o->op_flags & OPf_WANT;
1650 if ((want && want != OPf_WANT_SCALAR)
1651 || (PL_parser && PL_parser->error_count)
1652 || o->op_type == OP_RETURN || o->op_type == OP_REQUIRE || o->op_type == OP_LEAVEWHEN)
1653 {
1654 continue;
1655 }
1c846c1f 1656
26f0e7d5
TC
1657 if ((o->op_private & OPpTARGET_MY)
1658 && (PL_opargs[o->op_type] & OA_TARGLEX))/* OPp share the meaning */
1659 {
0d18dd72
FC
1660 /* newASSIGNOP has already applied scalar context, which we
1661 leave, as if this op is inside SASSIGN. */
26f0e7d5
TC
1662 continue;
1663 }
79072805 1664
26f0e7d5 1665 o->op_flags = (o->op_flags & ~OPf_WANT) | OPf_WANT_VOID;
75068674 1666
26f0e7d5
TC
1667 switch (o->op_type) {
1668 default:
1669 if (!(PL_opargs[o->op_type] & OA_FOLDCONST))
1670 break;
1671 /* FALLTHROUGH */
1672 case OP_REPEAT:
1673 if (o->op_flags & OPf_STACKED)
1674 break;
1675 goto func_ops;
1676 case OP_SUBSTR:
1677 if (o->op_private == 4)
1678 break;
1679 /* FALLTHROUGH */
26f0e7d5
TC
1680 case OP_WANTARRAY:
1681 case OP_GV:
1682 case OP_SMARTMATCH:
26f0e7d5
TC
1683 case OP_AV2ARYLEN:
1684 case OP_REF:
1685 case OP_REFGEN:
1686 case OP_SREFGEN:
1687 case OP_DEFINED:
1688 case OP_HEX:
1689 case OP_OCT:
1690 case OP_LENGTH:
1691 case OP_VEC:
1692 case OP_INDEX:
1693 case OP_RINDEX:
1694 case OP_SPRINTF:
26f0e7d5 1695 case OP_KVASLICE:
26f0e7d5
TC
1696 case OP_KVHSLICE:
1697 case OP_UNPACK:
1698 case OP_PACK:
1699 case OP_JOIN:
1700 case OP_LSLICE:
1701 case OP_ANONLIST:
1702 case OP_ANONHASH:
1703 case OP_SORT:
1704 case OP_REVERSE:
1705 case OP_RANGE:
1706 case OP_FLIP:
1707 case OP_FLOP:
1708 case OP_CALLER:
1709 case OP_FILENO:
1710 case OP_EOF:
1711 case OP_TELL:
1712 case OP_GETSOCKNAME:
1713 case OP_GETPEERNAME:
1714 case OP_READLINK:
1715 case OP_TELLDIR:
1716 case OP_GETPPID:
1717 case OP_GETPGRP:
1718 case OP_GETPRIORITY:
1719 case OP_TIME:
1720 case OP_TMS:
1721 case OP_LOCALTIME:
1722 case OP_GMTIME:
1723 case OP_GHBYNAME:
1724 case OP_GHBYADDR:
1725 case OP_GHOSTENT:
1726 case OP_GNBYNAME:
1727 case OP_GNBYADDR:
1728 case OP_GNETENT:
1729 case OP_GPBYNAME:
1730 case OP_GPBYNUMBER:
1731 case OP_GPROTOENT:
1732 case OP_GSBYNAME:
1733 case OP_GSBYPORT:
1734 case OP_GSERVENT:
1735 case OP_GPWNAM:
1736 case OP_GPWUID:
1737 case OP_GGRNAM:
1738 case OP_GGRGID:
1739 case OP_GETLOGIN:
1740 case OP_PROTOTYPE:
1741 case OP_RUNCV:
1742 func_ops:
9e209402
FC
1743 useless = OP_DESC(o);
1744 break;
1745
1746 case OP_GVSV:
1747 case OP_PADSV:
1748 case OP_PADAV:
1749 case OP_PADHV:
1750 case OP_PADANY:
1751 case OP_AELEM:
1752 case OP_AELEMFAST:
1753 case OP_AELEMFAST_LEX:
1754 case OP_ASLICE:
1755 case OP_HELEM:
1756 case OP_HSLICE:
26f0e7d5
TC
1757 if (!(o->op_private & (OPpLVAL_INTRO|OPpOUR_INTRO)))
1758 /* Otherwise it's "Useless use of grep iterator" */
1759 useless = OP_DESC(o);
1760 break;
1761
1762 case OP_SPLIT:
1763 kid = cLISTOPo->op_first;
1764 if (kid && kid->op_type == OP_PUSHRE
1765 && !kid->op_targ
1766 && !(o->op_flags & OPf_STACKED)
75068674 1767#ifdef USE_ITHREADS
26f0e7d5 1768 && !((PMOP*)kid)->op_pmreplrootu.op_pmtargetoff
75068674 1769#else
26f0e7d5 1770 && !((PMOP*)kid)->op_pmreplrootu.op_pmtargetgv
75068674 1771#endif
26f0e7d5
TC
1772 )
1773 useless = OP_DESC(o);
1774 break;
1775
1776 case OP_NOT:
1777 kid = cUNOPo->op_first;
1778 if (kid->op_type != OP_MATCH && kid->op_type != OP_SUBST &&
1779 kid->op_type != OP_TRANS && kid->op_type != OP_TRANSR) {
1780 goto func_ops;
1781 }
1782 useless = "negative pattern binding (!~)";
1783 break;
1784
1785 case OP_SUBST:
1786 if (cPMOPo->op_pmflags & PMf_NONDESTRUCT)
1787 useless = "non-destructive substitution (s///r)";
1788 break;
1789
1790 case OP_TRANSR:
1791 useless = "non-destructive transliteration (tr///r)";
1792 break;
1793
1794 case OP_RV2GV:
1795 case OP_RV2SV:
1796 case OP_RV2AV:
1797 case OP_RV2HV:
1798 if (!(o->op_private & (OPpLVAL_INTRO|OPpOUR_INTRO)) &&
1799 (!OP_HAS_SIBLING(o) || OP_SIBLING(o)->op_type != OP_READLINE))
1800 useless = "a variable";
1801 break;
1802
1803 case OP_CONST:
1804 sv = cSVOPo_sv;
1805 if (cSVOPo->op_private & OPpCONST_STRICT)
1806 no_bareword_allowed(o);
1807 else {
1808 if (ckWARN(WARN_VOID)) {
1809 NV nv;
1810 /* don't warn on optimised away booleans, eg
1811 * use constant Foo, 5; Foo || print; */
1812 if (cSVOPo->op_private & OPpCONST_SHORTCIRCUIT)
1813 useless = NULL;
1814 /* the constants 0 and 1 are permitted as they are
1815 conventionally used as dummies in constructs like
1816 1 while some_condition_with_side_effects; */
1817 else if (SvNIOK(sv) && ((nv = SvNV(sv)) == 0.0 || nv == 1.0))
1818 useless = NULL;
1819 else if (SvPOK(sv)) {
1820 SV * const dsv = newSVpvs("");
1821 useless_sv
1822 = Perl_newSVpvf(aTHX_
1823 "a constant (%s)",
1824 pv_pretty(dsv, SvPVX_const(sv),
1825 SvCUR(sv), 32, NULL, NULL,
1826 PERL_PV_PRETTY_DUMP
1827 | PERL_PV_ESCAPE_NOCLEAR
1828 | PERL_PV_ESCAPE_UNI_DETECT));
1829 SvREFCNT_dec_NN(dsv);
1830 }
1831 else if (SvOK(sv)) {
1832 useless_sv = Perl_newSVpvf(aTHX_ "a constant (%"SVf")", SVfARG(sv));
1833 }
1834 else
1835 useless = "a constant (undef)";
1836 }
1837 }
1838 op_null(o); /* don't execute or even remember it */
1839 break;
79072805 1840
26f0e7d5
TC
1841 case OP_POSTINC:
1842 CHANGE_TYPE(o, OP_PREINC); /* pre-increment is faster */
1843 break;
79072805 1844
26f0e7d5
TC
1845 case OP_POSTDEC:
1846 CHANGE_TYPE(o, OP_PREDEC); /* pre-decrement is faster */
1847 break;
79072805 1848
26f0e7d5
TC
1849 case OP_I_POSTINC:
1850 CHANGE_TYPE(o, OP_I_PREINC); /* pre-increment is faster */
1851 break;
79072805 1852
26f0e7d5
TC
1853 case OP_I_POSTDEC:
1854 CHANGE_TYPE(o, OP_I_PREDEC); /* pre-decrement is faster */
1855 break;
679d6c4e 1856
26f0e7d5
TC
1857 case OP_SASSIGN: {
1858 OP *rv2gv;
1859 UNOP *refgen, *rv2cv;
1860 LISTOP *exlist;
679d6c4e 1861
26f0e7d5
TC
1862 if ((o->op_private & ~OPpASSIGN_BACKWARDS) != 2)
1863 break;
f2f8fd84 1864
26f0e7d5
TC
1865 rv2gv = ((BINOP *)o)->op_last;
1866 if (!rv2gv || rv2gv->op_type != OP_RV2GV)
1867 break;
f2f8fd84 1868
26f0e7d5 1869 refgen = (UNOP *)((BINOP *)o)->op_first;
f2f8fd84 1870
26f0e7d5
TC
1871 if (!refgen || (refgen->op_type != OP_REFGEN
1872 && refgen->op_type != OP_SREFGEN))
1873 break;
f2f8fd84 1874
26f0e7d5
TC
1875 exlist = (LISTOP *)refgen->op_first;
1876 if (!exlist || exlist->op_type != OP_NULL
1877 || exlist->op_targ != OP_LIST)
1878 break;
f2f8fd84 1879
26f0e7d5
TC
1880 if (exlist->op_first->op_type != OP_PUSHMARK
1881 && exlist->op_first != exlist->op_last)
1882 break;
f2f8fd84 1883
26f0e7d5 1884 rv2cv = (UNOP*)exlist->op_last;
f2f8fd84 1885
26f0e7d5
TC
1886 if (rv2cv->op_type != OP_RV2CV)
1887 break;
f2f8fd84 1888
26f0e7d5
TC
1889 assert ((rv2gv->op_private & OPpDONT_INIT_GV) == 0);
1890 assert ((o->op_private & OPpASSIGN_CV_TO_GV) == 0);
1891 assert ((rv2cv->op_private & OPpMAY_RETURN_CONSTANT) == 0);
f2f8fd84 1892
26f0e7d5
TC
1893 o->op_private |= OPpASSIGN_CV_TO_GV;
1894 rv2gv->op_private |= OPpDONT_INIT_GV;
1895 rv2cv->op_private |= OPpMAY_RETURN_CONSTANT;
f2f8fd84 1896
26f0e7d5
TC
1897 break;
1898 }
540dd770 1899
26f0e7d5
TC
1900 case OP_AASSIGN: {
1901 inplace_aassign(o);
1902 break;
1903 }
edbe35ea 1904
26f0e7d5
TC
1905 case OP_OR:
1906 case OP_AND:
1907 kid = cLOGOPo->op_first;
1908 if (kid->op_type == OP_NOT
1909 && (kid->op_flags & OPf_KIDS)) {
1910 if (o->op_type == OP_AND) {
1911 CHANGE_TYPE(o, OP_OR);
1912 } else {
1913 CHANGE_TYPE(o, OP_AND);
1914 }
1915 op_null(kid);
1916 }
1917 /* FALLTHROUGH */
5aabfad6 1918
26f0e7d5
TC
1919 case OP_DOR:
1920 case OP_COND_EXPR:
1921 case OP_ENTERGIVEN:
1922 case OP_ENTERWHEN:
1923 for (kid = OP_SIBLING(cUNOPo->op_first); kid; kid = OP_SIBLING(kid))
1924 if (!(kid->op_flags & OPf_KIDS))
1925 scalarvoid(kid);
1926 else
1927 DEFER_OP(kid);
aa9d1253 1928 break;
095b19d1 1929
26f0e7d5
TC
1930 case OP_NULL:
1931 if (o->op_flags & OPf_STACKED)
1932 break;
1933 /* FALLTHROUGH */
1934 case OP_NEXTSTATE:
1935 case OP_DBSTATE:
1936 case OP_ENTERTRY:
1937 case OP_ENTER:
1938 if (!(o->op_flags & OPf_KIDS))
1939 break;
1940 /* FALLTHROUGH */
1941 case OP_SCOPE:
1942 case OP_LEAVE:
1943 case OP_LEAVETRY:
1944 case OP_LEAVELOOP:
1945 case OP_LINESEQ:
1946 case OP_LEAVEGIVEN:
1947 case OP_LEAVEWHEN:
1948 kids:
1949 for (kid = cLISTOPo->op_first; kid; kid = OP_SIBLING(kid))
1950 if (!(kid->op_flags & OPf_KIDS))
1951 scalarvoid(kid);
1952 else
1953 DEFER_OP(kid);
1954 break;
1955 case OP_LIST:
1956 /* If the first kid after pushmark is something that the padrange
1957 optimisation would reject, then null the list and the pushmark.
1958 */
1959 if ((kid = cLISTOPo->op_first)->op_type == OP_PUSHMARK
1960 && ( !(kid = OP_SIBLING(kid))
1961 || ( kid->op_type != OP_PADSV
1962 && kid->op_type != OP_PADAV
1963 && kid->op_type != OP_PADHV)
1964 || kid->op_private & ~OPpLVAL_INTRO
1965 || !(kid = OP_SIBLING(kid))
1966 || ( kid->op_type != OP_PADSV
1967 && kid->op_type != OP_PADAV
1968 && kid->op_type != OP_PADHV)
1969 || kid->op_private & ~OPpLVAL_INTRO)
1970 ) {
1971 op_null(cUNOPo->op_first); /* NULL the pushmark */
1972 op_null(o); /* NULL the list */
1973 }
1974 goto kids;
1975 case OP_ENTEREVAL:
1976 scalarkids(o);
1977 break;
1978 case OP_SCALAR:
1979 scalar(o);
1980 break;
1981 }
1982
1983 if (useless_sv) {
1984 /* mortalise it, in case warnings are fatal. */
1985 Perl_ck_warner(aTHX_ packWARN(WARN_VOID),
1986 "Useless use of %"SVf" in void context",
1987 SVfARG(sv_2mortal(useless_sv)));
1988 }
1989 else if (useless) {
1990 Perl_ck_warner(aTHX_ packWARN(WARN_VOID),
1991 "Useless use of %s in void context",
1992 useless);
1993 }
aa9d1253
TC
1994 } while ( (o = POP_DEFERRED_OP()) );
1995
1996 Safefree(defer_stack);
1997
1998 return arg;
79072805
LW
1999}
2000
1f676739 2001static OP *
412da003 2002S_listkids(pTHX_ OP *o)
79072805 2003{
11343788 2004 if (o && o->op_flags & OPf_KIDS) {
6867be6d 2005 OP *kid;
1ed44841 2006 for (kid = cLISTOPo->op_first; kid; kid = OP_SIBLING(kid))
79072805
LW
2007 list(kid);
2008 }
11343788 2009 return o;
79072805
LW
2010}
2011
2012OP *
864dbfa3 2013Perl_list(pTHX_ OP *o)
79072805
LW
2014{
2015 OP *kid;
2016
a0d0e21e 2017 /* assumes no premature commitment */
13765c85
DM
2018 if (!o || (o->op_flags & OPf_WANT)
2019 || (PL_parser && PL_parser->error_count)
5dc0d613 2020 || o->op_type == OP_RETURN)
7e363e51 2021 {
11343788 2022 return o;
7e363e51 2023 }
79072805 2024
b162f9ea 2025 if ((o->op_private & OPpTARGET_MY)
7e363e51
GS
2026 && (PL_opargs[o->op_type] & OA_TARGLEX))/* OPp share the meaning */
2027 {
b162f9ea 2028 return o; /* As if inside SASSIGN */
7e363e51 2029 }
1c846c1f 2030
5dc0d613 2031 o->op_flags = (o->op_flags & ~OPf_WANT) | OPf_WANT_LIST;
79072805 2032
11343788 2033 switch (o->op_type) {
79072805 2034 case OP_FLOP:
11343788 2035 list(cBINOPo->op_first);
79072805 2036 break;
c57eecc5
FC
2037 case OP_REPEAT:
2038 if (o->op_private & OPpREPEAT_DOLIST
2039 && !(o->op_flags & OPf_STACKED))
2040 {
2041 list(cBINOPo->op_first);
2042 kid = cBINOPo->op_last;
2043 if (kid->op_type == OP_CONST && SvIOK(kSVOP_sv)
2044 && SvIVX(kSVOP_sv) == 1)
2045 {
2046 op_null(o); /* repeat */
2047 op_null(cUNOPx(cBINOPo->op_first)->op_first);/* pushmark */
2048 /* const (rhs): */
2049 op_free(op_sibling_splice(o, cBINOPo->op_first, 1, NULL));
2050 }
2051 }
2052 break;
79072805
LW
2053 case OP_OR:
2054 case OP_AND:
2055 case OP_COND_EXPR:
1ed44841 2056 for (kid = OP_SIBLING(cUNOPo->op_first); kid; kid = OP_SIBLING(kid))
79072805
LW
2057 list(kid);
2058 break;
2059 default:
2060 case OP_MATCH:
8782bef2 2061 case OP_QR:
79072805
LW
2062 case OP_SUBST:
2063 case OP_NULL:
11343788 2064 if (!(o->op_flags & OPf_KIDS))
79072805 2065 break;
11343788
MB
2066 if (!o->op_next && cUNOPo->op_first->op_type == OP_FLOP) {
2067 list(cBINOPo->op_first);
2068 return gen_constant_list(o);
79072805 2069 }
6aa68307
FC
2070 listkids(o);
2071 break;
79072805 2072 case OP_LIST:
11343788 2073 listkids(o);
6aa68307
FC
2074 if (cLISTOPo->op_first->op_type == OP_PUSHMARK) {
2075 op_null(cUNOPo->op_first); /* NULL the pushmark */
2076 op_null(o); /* NULL the list */
2077 }
79072805
LW
2078 break;
2079 case OP_LEAVE:
2080 case OP_LEAVETRY:
5dc0d613 2081 kid = cLISTOPo->op_first;
54310121 2082 list(kid);
1ed44841 2083 kid = OP_SIBLING(kid);
25b991bf
VP
2084 do_kids:
2085 while (kid) {
1ed44841 2086 OP *sib = OP_SIBLING(kid);
c08f093b
VP
2087 if (sib && kid->op_type != OP_LEAVEWHEN)
2088 scalarvoid(kid);
2089 else
54310121 2090 list(kid);
25b991bf 2091 kid = sib;
54310121 2092 }
11206fdd 2093 PL_curcop = &PL_compiling;
54310121 2094 break;
748a9306 2095 case OP_SCOPE:
79072805 2096 case OP_LINESEQ:
25b991bf
VP
2097 kid = cLISTOPo->op_first;
2098 goto do_kids;
79072805 2099 }
11343788 2100 return o;
79072805
LW
2101}
2102
1f676739 2103static OP *
2dd5337b 2104S_scalarseq(pTHX_ OP *o)
79072805 2105{
11343788 2106 if (o) {
1496a290
AL
2107 const OPCODE type = o->op_type;
2108
2109 if (type == OP_LINESEQ || type == OP_SCOPE ||
2110 type == OP_LEAVE || type == OP_LEAVETRY)
463ee0b2 2111 {
b7bea5da
FC
2112 OP *kid, *sib;
2113 for (kid = cLISTOPo->op_first; kid; kid = sib) {
2114 if ((sib = OP_SIBLING(kid))
2115 && ( OP_HAS_SIBLING(sib) || sib->op_type != OP_NULL
2116 || ( sib->op_targ != OP_NEXTSTATE
2117 && sib->op_targ != OP_DBSTATE )))
2118 {
463ee0b2 2119 scalarvoid(kid);
ed6116ce 2120 }
463ee0b2 2121 }
3280af22 2122 PL_curcop = &PL_compiling;
79072805 2123 }
11343788 2124 o->op_flags &= ~OPf_PARENS;
3280af22 2125 if (PL_hints & HINT_BLOCK_SCOPE)
11343788 2126 o->op_flags |= OPf_PARENS;
79072805 2127 }
8990e307 2128 else
11343788
MB
2129 o = newOP(OP_STUB, 0);
2130 return o;
79072805
LW
2131}
2132
76e3520e 2133STATIC OP *
cea2e8a9 2134S_modkids(pTHX_ OP *o, I32 type)
79072805 2135{
11343788 2136 if (o && o->op_flags & OPf_KIDS) {
6867be6d 2137 OP *kid;
1ed44841 2138 for (kid = cLISTOPo->op_first; kid; kid = OP_SIBLING(kid))
3ad73efd 2139 op_lvalue(kid, type);
79072805 2140 }
11343788 2141 return o;
79072805
LW
2142}
2143
3ad73efd 2144/*
d164302a
GG
2145=for apidoc finalize_optree
2146
72d33970
FC
2147This function finalizes the optree. Should be called directly after
2148the complete optree is built. It does some additional
d164302a
GG
2149checking which can't be done in the normal ck_xxx functions and makes
2150the tree thread-safe.
2151
2152=cut
2153*/
2154void
2155Perl_finalize_optree(pTHX_ OP* o)
2156{
2157 PERL_ARGS_ASSERT_FINALIZE_OPTREE;
2158
2159 ENTER;
2160 SAVEVPTR(PL_curcop);
2161
2162 finalize_op(o);
2163
2164 LEAVE;
2165}
2166
b46e009d 2167#ifdef USE_ITHREADS
2168/* Relocate sv to the pad for thread safety.
2169 * Despite being a "constant", the SV is written to,
2170 * for reference counts, sv_upgrade() etc. */
2171PERL_STATIC_INLINE void
2172S_op_relocate_sv(pTHX_ SV** svp, PADOFFSET* targp)
2173{
2174 PADOFFSET ix;
2175 PERL_ARGS_ASSERT_OP_RELOCATE_SV;
2176 if (!*svp) return;
2177 ix = pad_alloc(OP_CONST, SVf_READONLY);
2178 SvREFCNT_dec(PAD_SVl(ix));
2179 PAD_SETSV(ix, *svp);
2180 /* XXX I don't know how this isn't readonly already. */
2181 if (!SvIsCOW(PAD_SVl(ix))) SvREADONLY_on(PAD_SVl(ix));
2182 *svp = NULL;
2183 *targp = ix;
2184}
2185#endif
2186
2187
60dde6b2 2188STATIC void
d164302a
GG
2189S_finalize_op(pTHX_ OP* o)
2190{
2191 PERL_ARGS_ASSERT_FINALIZE_OP;
2192
d164302a
GG
2193
2194 switch (o->op_type) {
2195 case OP_NEXTSTATE:
2196 case OP_DBSTATE:
2197 PL_curcop = ((COP*)o); /* for warnings */
2198 break;
2199 case OP_EXEC:
1ed44841
DM
2200 if (OP_HAS_SIBLING(o)) {
2201 OP *sib = OP_SIBLING(o);
2202 if (( sib->op_type == OP_NEXTSTATE || sib->op_type == OP_DBSTATE)
2203 && ckWARN(WARN_EXEC)
2204 && OP_HAS_SIBLING(sib))
2205 {
2206 const OPCODE type = OP_SIBLING(sib)->op_type;
d164302a
GG
2207 if (type != OP_EXIT && type != OP_WARN && type != OP_DIE) {
2208 const line_t oldline = CopLINE(PL_curcop);
1ed44841 2209 CopLINE_set(PL_curcop, CopLINE((COP*)sib));
d164302a
GG
2210 Perl_warner(aTHX_ packWARN(WARN_EXEC),
2211 "Statement unlikely to be reached");
2212 Perl_warner(aTHX_ packWARN(WARN_EXEC),
2213 "\t(Maybe you meant system() when you said exec()?)\n");
2214 CopLINE_set(PL_curcop, oldline);
2215 }
d164302a 2216 }
1ed44841 2217 }
d164302a
GG
2218 break;
2219
2220 case OP_GV:
2221 if ((o->op_private & OPpEARLY_CV) && ckWARN(WARN_PROTOTYPE)) {
2222 GV * const gv = cGVOPo_gv;
2223 if (SvTYPE(gv) == SVt_PVGV && GvCV(gv) && SvPVX_const(GvCV(gv))) {
2224 /* XXX could check prototype here instead of just carping */
2225 SV * const sv = sv_newmortal();
2226 gv_efullname3(sv, gv, NULL);
2227 Perl_warner(aTHX_ packWARN(WARN_PROTOTYPE),
2228 "%"SVf"() called too early to check prototype",
2229 SVfARG(sv));
2230 }
2231 }
2232 break;
2233
2234 case OP_CONST:
eb796c7f
GG
2235 if (cSVOPo->op_private & OPpCONST_STRICT)
2236 no_bareword_allowed(o);
2237 /* FALLTHROUGH */
d164302a
GG
2238#ifdef USE_ITHREADS
2239 case OP_HINTSEVAL:
b46e009d 2240 op_relocate_sv(&cSVOPo->op_sv, &o->op_targ);
2241#endif
2242 break;
2243
2244#ifdef USE_ITHREADS
2245 /* Relocate all the METHOP's SVs to the pad for thread safety. */
d164302a 2246 case OP_METHOD_NAMED:
7d6c333c 2247 case OP_METHOD_SUPER:
810bd8b7 2248 case OP_METHOD_REDIR:
2249 case OP_METHOD_REDIR_SUPER:
b46e009d 2250 op_relocate_sv(&cMETHOPx(o)->op_u.op_meth_sv, &o->op_targ);
2251 break;
d164302a 2252#endif
d164302a
GG
2253
2254 case OP_HELEM: {
2255 UNOP *rop;
a1c2aa4c 2256 PADNAME *lexname;
d164302a 2257 GV **fields;
565e6f7e
FC
2258 SVOP *key_op;
2259 OP *kid;
2260 bool check_fields;
d164302a 2261
565e6f7e 2262 if ((key_op = cSVOPx(((BINOP*)o)->op_last))->op_type != OP_CONST)
d164302a
GG
2263 break;
2264
2265 rop = (UNOP*)((BINOP*)o)->op_first;
e6307ed0 2266
565e6f7e 2267 goto check_keys;
d164302a 2268
565e6f7e 2269 case OP_HSLICE:
429a2555 2270 S_scalar_slice_warning(aTHX_ o);
c67159e1 2271 /* FALLTHROUGH */
429a2555 2272
c5f75dba 2273 case OP_KVHSLICE:
1ed44841 2274 kid = OP_SIBLING(cLISTOPo->op_first);
71323522 2275 if (/* I bet there's always a pushmark... */
7d3c8a68
SM
2276 OP_TYPE_ISNT_AND_WASNT_NN(kid, OP_LIST)
2277 && OP_TYPE_ISNT_NN(kid, OP_CONST))
2278 {
d164302a 2279 break;
7d3c8a68 2280 }
565e6f7e
FC
2281
2282 key_op = (SVOP*)(kid->op_type == OP_CONST
2283 ? kid
1ed44841 2284 : OP_SIBLING(kLISTOP->op_first));
565e6f7e
FC
2285
2286 rop = (UNOP*)((LISTOP*)o)->op_last;
2287
2288 check_keys:
2289 if (o->op_private & OPpLVAL_INTRO || rop->op_type != OP_RV2HV)
71323522 2290 rop = NULL;
565e6f7e 2291 else if (rop->op_first->op_type == OP_PADSV)
d164302a
GG
2292 /* @$hash{qw(keys here)} */
2293 rop = (UNOP*)rop->op_first;
565e6f7e 2294 else {
d164302a
GG
2295 /* @{$hash}{qw(keys here)} */
2296 if (rop->op_first->op_type == OP_SCOPE
2297 && cLISTOPx(rop->op_first)->op_last->op_type == OP_PADSV)
2298 {
2299 rop = (UNOP*)cLISTOPx(rop->op_first)->op_last;
2300 }
2301 else
71323522 2302 rop = NULL;
d164302a 2303 }
71323522 2304
32e9ec8f 2305 lexname = NULL; /* just to silence compiler warnings */
03acb648
DM
2306 fields = NULL; /* just to silence compiler warnings */
2307
71323522
FC
2308 check_fields =
2309 rop
9b7476d7 2310 && (lexname = padnamelist_fetch(PL_comppad_name, rop->op_targ),
71323522 2311 SvPAD_TYPED(lexname))
a1c2aa4c
FC
2312 && (fields =
2313 (GV**)hv_fetchs(PadnameTYPE(lexname), "FIELDS", FALSE))
71323522 2314 && isGV(*fields) && GvHV(*fields);
0e706dd4 2315 for (; key_op;
1ed44841 2316 key_op = (SVOP*)OP_SIBLING(key_op)) {
565e6f7e 2317 SV **svp, *sv;
d164302a
GG
2318 if (key_op->op_type != OP_CONST)
2319 continue;
2320 svp = cSVOPx_svp(key_op);
71323522
FC
2321
2322 /* Make the CONST have a shared SV */
2323 if ((!SvIsCOW_shared_hash(sv = *svp))
2324 && SvTYPE(sv) < SVt_PVMG && SvOK(sv) && !SvROK(sv)) {
2325 SSize_t keylen;
2326 const char * const key = SvPV_const(sv, *(STRLEN*)&keylen);
2327 SV *nsv = newSVpvn_share(key,
2328 SvUTF8(sv) ? -keylen : keylen, 0);
2329 SvREFCNT_dec_NN(sv);
2330 *svp = nsv;
2331 }
2332
2333 if (check_fields
2334 && !hv_fetch_ent(GvHV(*fields), *svp, FALSE, 0)) {
ce16c625 2335 Perl_croak(aTHX_ "No such class field \"%"SVf"\" "
a1c2aa4c
FC
2336 "in variable %"PNf" of type %"HEKf,
2337 SVfARG(*svp), PNfARG(lexname),
2338 HEKfARG(HvNAME_HEK(PadnameTYPE(lexname))));
d164302a
GG
2339 }
2340 }
2341 break;
2342 }
429a2555
FC
2343 case OP_ASLICE:
2344 S_scalar_slice_warning(aTHX_ o);
2345 break;
a7fd8ef6 2346
d164302a
GG
2347 case OP_SUBST: {
2348 if (cPMOPo->op_pmreplrootu.op_pmreplroot)
2349 finalize_op(cPMOPo->op_pmreplrootu.op_pmreplroot);
2350 break;
2351 }
2352 default:
2353 break;
2354 }
2355
2356 if (o->op_flags & OPf_KIDS) {
2357 OP *kid;
c4b20975
DM
2358
2359#ifdef DEBUGGING
20220689
DM
2360 /* check that op_last points to the last sibling, and that
2361 * the last op_sibling field points back to the parent, and
2362 * that the only ops with KIDS are those which are entitled to
2363 * them */
c4b20975
DM
2364 U32 type = o->op_type;
2365 U32 family;
20220689 2366 bool has_last;
c4b20975
DM
2367
2368 if (type == OP_NULL) {
2369 type = o->op_targ;
2370 /* ck_glob creates a null UNOP with ex-type GLOB
2371 * (which is a list op. So pretend it wasn't a listop */
2372 if (type == OP_GLOB)
2373 type = OP_NULL;
2374 }
2375 family = PL_opargs[type] & OA_CLASS_MASK;
2376
20220689
DM
2377 has_last = ( family == OA_BINOP
2378 || family == OA_LISTOP
2379 || family == OA_PMOP
2380 || family == OA_LOOP
2381 );
2382 assert( has_last /* has op_first and op_last, or ...
2383 ... has (or may have) op_first: */
2384 || family == OA_UNOP
2385 || family == OA_LOGOP
2386 || family == OA_BASEOP_OR_UNOP
2387 || family == OA_FILESTATOP
2388 || family == OA_LOOPEXOP
b46e009d 2389 || family == OA_METHOP
20220689
DM
2390 /* I don't know why SASSIGN is tagged as OA_BASEOP - DAPM */
2391 || type == OP_SASSIGN
2392 || type == OP_CUSTOM
2393 || type == OP_NULL /* new_logop does this */
2394 );
2395 /* XXX list form of 'x' is has a null op_last. This is wrong,
2396 * but requires too much hacking (e.g. in Deparse) to fix for
2397 * now */
2398 if (type == OP_REPEAT && (o->op_private & OPpREPEAT_DOLIST)) {
2399 assert(has_last);
2400 has_last = 0;
2401 }
2402
2403 for (kid = cUNOPo->op_first; kid; kid = OP_SIBLING(kid)) {
29e61fd9 2404# ifdef PERL_OP_PARENT
20220689
DM
2405 if (!OP_HAS_SIBLING(kid)) {
2406 if (has_last)
29e61fd9 2407 assert(kid == cLISTOPo->op_last);
20220689
DM
2408 assert(kid->op_sibling == o);
2409 }
29e61fd9 2410# else
20220689
DM
2411 if (OP_HAS_SIBLING(kid)) {
2412 assert(!kid->op_lastsib);
2413 }
2414 else {
2415 assert(kid->op_lastsib);
2416 if (has_last)
29e61fd9 2417 assert(kid == cLISTOPo->op_last);
c4b20975 2418 }
20220689 2419# endif
c4b20975
DM
2420 }
2421#endif
2422
1ed44841 2423 for (kid = cUNOPo->op_first; kid; kid = OP_SIBLING(kid))
d164302a
GG
2424 finalize_op(kid);
2425 }
2426}
2427
2428/*
3ad73efd
Z
2429=for apidoc Amx|OP *|op_lvalue|OP *o|I32 type
2430
2431Propagate lvalue ("modifiable") context to an op and its children.
2432I<type> represents the context type, roughly based on the type of op that
2433would do the modifying, although C<local()> is represented by OP_NULL,
2434because it has no op type of its own (it is signalled by a flag on
001c3c51
FC
2435the lvalue op).
2436
2437This function detects things that can't be modified, such as C<$x+1>, and
72d33970 2438generates errors for them. For example, C<$x+1 = 2> would cause it to be
001c3c51
FC
2439called with an op of type OP_ADD and a C<type> argument of OP_SASSIGN.
2440
2441It also flags things that need to behave specially in an lvalue context,
2442such as C<$$x = 5> which might have to vivify a reference in C<$x>.
3ad73efd
Z
2443
2444=cut
2445*/
ddeae0f1 2446
03414f05
FC
2447static void
2448S_mark_padname_lvalue(pTHX_ PADNAME *pn)
2449{
2450 CV *cv = PL_compcv;
2451 PadnameLVALUE_on(pn);
2452 while (PadnameOUTER(pn) && PARENT_PAD_INDEX(pn)) {
2453 cv = CvOUTSIDE(cv);
2454 assert(cv);
2455 assert(CvPADLIST(cv));
2456 pn =
2457 PadlistNAMESARRAY(CvPADLIST(cv))[PARENT_PAD_INDEX(pn)];
2458 assert(PadnameLEN(pn));
2459 PadnameLVALUE_on(pn);
2460 }
2461}
2462
375879aa
FC
2463static bool
2464S_vivifies(const OPCODE type)
2465{
2466 switch(type) {
2467 case OP_RV2AV: case OP_ASLICE:
2468 case OP_RV2HV: case OP_KVASLICE:
2469 case OP_RV2SV: case OP_HSLICE:
2470 case OP_AELEMFAST: case OP_KVHSLICE:
2471 case OP_HELEM:
2472 case OP_AELEM:
2473 return 1;
2474 }
2475 return 0;
2476}
2477
7664512e 2478static void
63702de8 2479S_lvref(pTHX_ OP *o, I32 type)
7664512e 2480{
727d2dc6 2481 dVAR;
7664512e
FC
2482 OP *kid;
2483 switch (o->op_type) {
2484 case OP_COND_EXPR:
2485 for (kid = OP_SIBLING(cUNOPo->op_first); kid;
2486 kid = OP_SIBLING(kid))
63702de8 2487 S_lvref(aTHX_ kid, type);
7664512e
FC
2488 /* FALLTHROUGH */
2489 case OP_PUSHMARK:
2490 return;
2491 case OP_RV2AV:
2492 if (cUNOPo->op_first->op_type != OP_GV) goto badref;
2493 o->op_flags |= OPf_STACKED;
2494 if (o->op_flags & OPf_PARENS) {
2495 if (o->op_private & OPpLVAL_INTRO) {
7664512e
FC
2496 yyerror(Perl_form(aTHX_ "Can't modify reference to "
2497 "localized parenthesized array in list assignment"));
2498 return;
2499 }
2500 slurpy:
10884df9 2501 CHANGE_TYPE(o, OP_LVAVREF);
7664512e
FC
2502 o->op_private &= OPpLVAL_INTRO|OPpPAD_STATE;
2503 o->op_flags |= OPf_MOD|OPf_REF;
2504 return;
2505 }
2506 o->op_private |= OPpLVREF_AV;
2507 goto checkgv;
408e9044 2508 case OP_RV2CV:
19abb1ea
FC
2509 kid = cUNOPo->op_first;
2510 if (kid->op_type == OP_NULL)
2511 kid = cUNOPx(kUNOP->op_first->op_sibling)
408e9044
FC
2512 ->op_first;
2513 o->op_private = OPpLVREF_CV;
2514 if (kid->op_type == OP_GV)
2515 o->op_flags |= OPf_STACKED;
2516 else if (kid->op_type == OP_PADCV) {
2517 o->op_targ = kid->op_targ;
2518 kid->op_targ = 0;
2519 op_free(cUNOPo->op_first);
2520 cUNOPo->op_first = NULL;
2521 o->op_flags &=~ OPf_KIDS;
2522 }
2523 else goto badref;
2524 break;
7664512e
FC
2525 case OP_RV2HV:
2526 if (o->op_flags & OPf_PARENS) {
2527 parenhash:
7664512e
FC
2528 yyerror(Perl_form(aTHX_ "Can't modify reference to "
2529 "parenthesized hash in list assignment"));
2530 return;
2531 }
2532 o->op_private |= OPpLVREF_HV;
2533 /* FALLTHROUGH */
2534 case OP_RV2SV:
2535 checkgv:
2536 if (cUNOPo->op_first->op_type != OP_GV) goto badref;
2537 o->op_flags |= OPf_STACKED;
6f5dab3c
FC
2538 break;
2539 case OP_PADHV:
2540 if (o->op_flags & OPf_PARENS) goto parenhash;
2541 o->op_private |= OPpLVREF_HV;
7664512e
FC
2542 /* FALLTHROUGH */
2543 case OP_PADSV:
6f5dab3c 2544 PAD_COMPNAME_GEN_set(o->op_targ, PERL_INT_MAX);
7664512e
FC
2545 break;
2546 case OP_PADAV:
6f5dab3c 2547 PAD_COMPNAME_GEN_set(o->op_targ, PERL_INT_MAX);
7664512e
FC
2548 if (o->op_flags & OPf_PARENS) goto slurpy;
2549 o->op_private |= OPpLVREF_AV;
2550 break;
7664512e
FC
2551 case OP_AELEM:
2552 case OP_HELEM:
2553 o->op_private |= OPpLVREF_ELEM;
2554 o->op_flags |= OPf_STACKED;
2555 break;
2556 case OP_ASLICE:
2557 case OP_HSLICE:
10884df9 2558 CHANGE_TYPE(o, OP_LVREFSLICE);
7664512e
FC
2559 o->op_private &= OPpLVAL_INTRO|OPpLVREF_ELEM;
2560 return;
2561 case OP_NULL:
2562 if (o->op_flags & OPf_SPECIAL) /* do BLOCK */
2563 goto badref;
2564 else if (!(o->op_flags & OPf_KIDS))
2565 return;
2566 if (o->op_targ != OP_LIST) {
63702de8 2567 S_lvref(aTHX_ cBINOPo->op_first, type);
7664512e
FC
2568 return;
2569 }
2570 /* FALLTHROUGH */
2571 case OP_LIST:
2572 for (kid = cLISTOPo->op_first; kid; kid = OP_SIBLING(kid)) {
2573 assert((kid->op_flags & OPf_WANT) != OPf_WANT_VOID);
63702de8 2574 S_lvref(aTHX_ kid, type);
7664512e
FC
2575 }
2576 return;
2577 case OP_STUB:
2578 if (o->op_flags & OPf_PARENS)
2579 return;
2580 /* FALLTHROUGH */
2581 default:
2582 badref:
cf6e1fa1 2583 /* diag_listed_as: Can't modify reference to %s in %s assignment */
63702de8 2584 yyerror(Perl_form(aTHX_ "Can't modify reference to %s in %s",
7664512e
FC
2585 o->op_type == OP_NULL && o->op_flags & OPf_SPECIAL
2586 ? "do block"
63702de8
FC
2587 : OP_DESC(o),
2588 PL_op_desc[type]));
7664512e
FC
2589 return;
2590 }
10884df9 2591 CHANGE_TYPE(o, OP_LVREF);
3ad7d304
FC
2592 o->op_private &=
2593 OPpLVAL_INTRO|OPpLVREF_ELEM|OPpLVREF_TYPE|OPpPAD_STATE;
d39c26a6
FC
2594 if (type == OP_ENTERLOOP)
2595 o->op_private |= OPpLVREF_ITER;
7664512e
FC
2596}
2597
79072805 2598OP *
d3d7d28f 2599Perl_op_lvalue_flags(pTHX_ OP *o, I32 type, U32 flags)
79072805 2600{
27da23d5 2601 dVAR;
79072805 2602 OP *kid;
ddeae0f1
DM
2603 /* -1 = error on localize, 0 = ignore localize, 1 = ok to localize */
2604 int localize = -1;
79072805 2605
13765c85 2606 if (!o || (PL_parser && PL_parser->error_count))
11343788 2607 return o;
79072805 2608
b162f9ea 2609 if ((o->op_private & OPpTARGET_MY)
7e363e51
GS
2610 && (PL_opargs[o->op_type] & OA_TARGLEX))/* OPp share the meaning */
2611 {
b162f9ea 2612 return o;
7e363e51 2613 }
1c846c1f 2614
5c906035
GG
2615 assert( (o->op_flags & OPf_WANT) != OPf_WANT_VOID );
2616
69974ce6
FC
2617 if (type == OP_PRTF || type == OP_SPRINTF) type = OP_ENTERSUB;
2618
11343788 2619 switch (o->op_type) {
68dc0745 2620 case OP_UNDEF:
3280af22 2621 PL_modcount++;
5dc0d613 2622 return o;
5f05dabc 2623 case OP_STUB:
b5bbe64a 2624 if ((o->op_flags & OPf_PARENS))
5f05dabc
PP
2625 break;
2626 goto nomod;
a0d0e21e 2627 case OP_ENTERSUB:
f79aa60b 2628 if ((type == OP_UNDEF || type == OP_REFGEN || type == OP_LOCK) &&
11343788 2629 !(o->op_flags & OPf_STACKED)) {
10884df9 2630 CHANGE_TYPE(o, OP_RV2CV); /* entersub => rv2cv */
11343788 2631 assert(cUNOPo->op_first->op_type == OP_NULL);
93c66552 2632 op_null(((LISTOP*)cUNOPo->op_first)->op_first);/* disable pushmark */
79072805
LW
2633 break;
2634 }
cd06dffe 2635 else { /* lvalue subroutine call */
9411a3c7 2636 o->op_private |= OPpLVAL_INTRO;
e6438c1a 2637 PL_modcount = RETURN_UNLIMITED_NUMBER;
9411a3c7
FC
2638 if (type == OP_GREPSTART || type == OP_ENTERSUB
2639 || type == OP_REFGEN || type == OP_LEAVESUBLV) {
d0887bf3 2640 /* Potential lvalue context: */
cd06dffe
GS
2641 o->op_private |= OPpENTERSUB_INARGS;
2642 break;
2643 }
2644 else { /* Compile-time error message: */
2645 OP *kid = cUNOPo->op_first;
2646 CV *cv;
2eaf799e 2647 GV *gv;
cd06dffe 2648
3ea285d1
AL
2649 if (kid->op_type != OP_PUSHMARK) {
2650 if (kid->op_type != OP_NULL || kid->op_targ != OP_LIST)
2651 Perl_croak(aTHX_
2652 "panic: unexpected lvalue entersub "
2653 "args: type/targ %ld:%"UVuf,
2654 (long)kid->op_type, (UV)kid->op_targ);
2655 kid = kLISTOP->op_first;
2656 }
1ed44841
DM
2657 while (OP_HAS_SIBLING(kid))
2658 kid = OP_SIBLING(kid);
cd06dffe 2659 if (!(kid->op_type == OP_NULL && kid->op_targ == OP_RV2CV)) {
cd06dffe
GS
2660 break; /* Postpone until runtime */
2661 }
b2ffa427 2662
cd06dffe
GS
2663 kid = kUNOP->op_first;
2664 if (kid->op_type == OP_NULL && kid->op_targ == OP_RV2SV)
2665 kid = kUNOP->op_first;
b2ffa427 2666 if (kid->op_type == OP_NULL)
cd06dffe
GS
2667 Perl_croak(aTHX_
2668 "Unexpected constant lvalue entersub "
55140b79 2669 "entry via type/targ %ld:%"UVuf,
3d811634 2670 (long)kid->op_type, (UV)kid->op_targ);
cd06dffe 2671 if (kid->op_type != OP_GV) {
cd06dffe
GS
2672 break;
2673 }
b2ffa427 2674
2eaf799e
FC
2675 gv = kGVOP_gv;
2676 cv = isGV(gv)
2677 ? GvCV(gv)
2678 : SvROK(gv) && SvTYPE(SvRV(gv)) == SVt_PVCV
2679 ? MUTABLE_CV(SvRV(gv))
2680 : NULL;
1c846c1f 2681 if (!cv)
da1dff94 2682 break;
cd06dffe
GS
2683 if (CvLVALUE(cv))
2684 break;
2685 }
2686 }
924ba076 2687 /* FALLTHROUGH */
79072805 2688 default:
a0d0e21e 2689 nomod:
f5d552b4 2690 if (flags & OP_LVALUE_NO_CROAK) return NULL;
6fbb66d6 2691 /* grep, foreach, subcalls, refgen */
145b2bbb
FC
2692 if (type == OP_GREPSTART || type == OP_ENTERSUB
2693 || type == OP_REFGEN || type == OP_LEAVESUBLV)
a0d0e21e 2694 break;
cea2e8a9 2695 yyerror(Perl_form(aTHX_ "Can't modify %s in %s",
638bc118 2696 (o->op_type == OP_NULL && (o->op_flags & OPf_SPECIAL)
cd06dffe
GS
2697 ? "do block"
2698 : (o->op_type == OP_ENTERSUB
2699 ? "non-lvalue subroutine call"
53e06cf0 2700 : OP_DESC(o))),
22c35a8c 2701 type ? PL_op_desc[type] : "local"));
11343788 2702 return o;
79072805 2703
a0d0e21e
LW
2704 case OP_PREINC:
2705 case OP_PREDEC:
2706 case OP_POW:
2707 case OP_MULTIPLY:
2708 case OP_DIVIDE:
2709 case OP_MODULO:
a0d0e21e
LW
2710 case OP_ADD:
2711 case OP_SUBTRACT:
2712 case OP_CONCAT:
2713 case OP_LEFT_SHIFT:
2714 case OP_RIGHT_SHIFT:
2715 case OP_BIT_AND:
2716 case OP_BIT_XOR:
2717 case OP_BIT_OR:
2718 case OP_I_MULTIPLY:
2719 case OP_I_DIVIDE:
2720 case OP_I_MODULO:
2721 case OP_I_ADD:
2722 case OP_I_SUBTRACT:
11343788 2723 if (!(o->op_flags & OPf_STACKED))
a0d0e21e 2724 goto nomod;
3280af22 2725 PL_modcount++;
a0d0e21e 2726 break;
b2ffa427 2727
82209a5d
FC
2728 case OP_REPEAT:
2729 if (o->op_flags & OPf_STACKED) {
2730 PL_modcount++;
2731 break;
2732 }
ff781254 2733 if (!(o->op_private & OPpREPEAT_DOLIST))
82209a5d
FC
2734 goto nomod;
2735 else {
2736 const I32 mods = PL_modcount;
ff781254
FC
2737 modkids(cBINOPo->op_first, type);
2738 if (type != OP_AASSIGN)
2739 goto nomod;
5e462669 2740 kid = cBINOPo->op_last;
82209a5d 2741 if (kid->op_type == OP_CONST && SvIOK(kSVOP_sv)) {
565e104c 2742 const IV iv = SvIV(kSVOP_sv);
82209a5d
FC
2743 if (PL_modcount != RETURN_UNLIMITED_NUMBER)
2744 PL_modcount =
2745 mods + (PL_modcount - mods) * (iv < 0 ? 0 : iv);
2746 }
2747 else
2748 PL_modcount = RETURN_UNLIMITED_NUMBER;
2749 }
2750 break;
2751
79072805 2752 case OP_COND_EXPR:
ddeae0f1 2753 localize = 1;
1ed44841 2754 for (kid = OP_SIBLING(cUNOPo->op_first); kid; kid = OP_SIBLING(kid))
3ad73efd 2755 op_lvalue(kid, type);
79072805
LW
2756 break;
2757
2758 case OP_RV2AV:
2759 case OP_RV2HV:
11343788 2760 if (type == OP_REFGEN && o->op_flags & OPf_PARENS) {
e6438c1a 2761 PL_modcount = RETURN_UNLIMITED_NUMBER;
11343788 2762 return o; /* Treat \(@foo) like ordinary list. */
748a9306 2763 }
924ba076 2764 /* FALLTHROUGH */
79072805 2765 case OP_RV2GV:
5dc0d613 2766 if (scalar_mod_type(o, type))
3fe9a6f1 2767 goto nomod;
11343788 2768 ref(cUNOPo->op_first, o->op_type);
924ba076 2769 /* FALLTHROUGH */
79072805
LW
2770 case OP_ASLICE:
2771 case OP_HSLICE:
ddeae0f1 2772 localize = 1;
924ba076 2773 /* FALLTHROUGH */
78f9721b 2774 case OP_AASSIGN:
32cbae3f
FC
2775 /* Do not apply the lvsub flag for rv2[ah]v in scalar context. */
2776 if (type == OP_LEAVESUBLV && (
2777 (o->op_type != OP_RV2AV && o->op_type != OP_RV2HV)
2778 || (o->op_flags & OPf_WANT) != OPf_WANT_SCALAR
2779 ))
631dbaa2 2780 o->op_private |= OPpMAYBE_LVSUB;
924ba076 2781 /* FALLTHROUGH */
93a17b20
LW
2782 case OP_NEXTSTATE:
2783 case OP_DBSTATE:
e6438c1a 2784 PL_modcount = RETURN_UNLIMITED_NUMBER;
79072805 2785 break;
5cae3edb 2786 case OP_KVHSLICE:
6dd3e0f2 2787 case OP_KVASLICE:
5cae3edb
RZ
2788 if (type == OP_LEAVESUBLV)
2789 o->op_private |= OPpMAYBE_LVSUB;
2790 goto nomod;
28c5b5bc
RGS
2791 case OP_AV2ARYLEN:
2792 PL_hints |= HINT_BLOCK_SCOPE;
2793 if (type == OP_LEAVESUBLV)
2794 o->op_private |= OPpMAYBE_LVSUB;
2795 PL_modcount++;
2796 break;
463ee0b2 2797 case OP_RV2SV:
aeea060c 2798 ref(cUNOPo->op_first, o->op_type);
ddeae0f1 2799 localize = 1;
924ba076 2800 /* FALLTHROUGH */
79072805 2801 case OP_GV:
3280af22 2802 PL_hints |= HINT_BLOCK_SCOPE;
924ba076 2803 /* FALLTHROUGH */
463ee0b2 2804 case OP_SASSIGN:
bf4b1e52
GS
2805 case OP_ANDASSIGN:
2806 case OP_ORASSIGN:
c963b151 2807 case OP_DORASSIGN:
ddeae0f1
DM
2808 PL_modcount++;
2809 break;
2810
8990e307 2811 case OP_AELEMFAST:
93bad3fd 2812 case OP_AELEMFAST_LEX:
6a077020 2813 localize = -1;
3280af22 2814 PL_modcount++;
8990e307
LW
2815 break;
2816
748a9306
LW
2817 case OP_PADAV:
2818 case OP_PADHV:
e6438c1a 2819 PL_modcount = RETURN_UNLIMITED_NUMBER;
5196be3e
MB
2820 if (type == OP_REFGEN && o->op_flags & OPf_PARENS)
2821 return o; /* Treat \(@foo) like ordinary list. */
2822 if (scalar_mod_type(o, type))
3fe9a6f1 2823 goto nomod;
32cbae3f
FC
2824 if ((o->op_flags & OPf_WANT) != OPf_WANT_SCALAR
2825 && type == OP_LEAVESUBLV)
78f9721b 2826 o->op_private |= OPpMAYBE_LVSUB;
924ba076 2827 /* FALLTHROUGH */
748a9306 2828 case OP_PADSV:
3280af22 2829 PL_modcount++;
ddeae0f1 2830 if (!type) /* local() */
ea9a9e77
FC
2831 Perl_croak(aTHX_ "Can't localize lexical variable %"PNf,
2832 PNfARG(PAD_COMPNAME(o->op_targ)));
e4211fee
FC
2833 if (!(o->op_private & OPpLVAL_INTRO)
2834 || ( type != OP_SASSIGN && type != OP_AASSIGN
2835 && PadnameIsSTATE(PAD_COMPNAME_SV(o->op_targ)) ))
03414f05 2836 S_mark_padname_lvalue(aTHX_ PAD_COMPNAME_SV(o->op_targ));
463ee0b2
LW
2837 break;
2838
748a9306 2839 case OP_PUSHMARK:
ddeae0f1 2840 localize = 0;
748a9306 2841 break;
b2ffa427 2842
69969c6f 2843 case OP_KEYS:
d8065907 2844 case OP_RKEYS:
fad4a2e4 2845 if (type != OP_SASSIGN && type != OP_LEAVESUBLV)
69969c6f 2846 goto nomod;
5d82c453
GA
2847 goto lvalue_func;
2848 case OP_SUBSTR:
2849 if (o->op_private == 4) /* don't allow 4 arg substr as lvalue */
2850 goto nomod;
924ba076 2851 /* FALLTHROUGH */
a0d0e21e 2852 case OP_POS:
463ee0b2 2853 case OP_VEC:
fad4a2e4 2854 lvalue_func:
78f9721b
SM
2855 if (type == OP_LEAVESUBLV)
2856 o->op_private |= OPpMAYBE_LVSUB;
11343788 2857 if (o->op_flags & OPf_KIDS)
1ed44841 2858 op_lvalue(OP_SIBLING(cBINOPo->op_first), type);
463ee0b2 2859 break;
a0d0e21e 2860
463ee0b2
LW
2861 case OP_AELEM:
2862 case OP_HELEM:
11343788 2863 ref(cBINOPo->op_first, o->op_type);
68dc0745 2864 if (type == OP_ENTERSUB &&
5dc0d613
MB
2865 !(o->op_private & (OPpLVAL_INTRO | OPpDEREF)))
2866 o->op_private |= OPpLVAL_DEFER;
78f9721b
SM
2867 if (type == OP_LEAVESUBLV)
2868 o->op_private |= OPpMAYBE_LVSUB;
ddeae0f1 2869 localize = 1;
3280af22 2870 PL_modcount++;
463ee0b2
LW
2871 break;
2872
463ee0b2 2873 case OP_LEAVE:
a373464f 2874 case OP_LEAVELOOP:
2ec7f6f2 2875 o->op_private |= OPpLVALUE;
924ba076 2876 /* FALLTHROUGH */
2ec7f6f2 2877 case OP_SCOPE:
463ee0b2 2878 case OP_ENTER:
78f9721b 2879 case OP_LINESEQ:
ddeae0f1 2880 localize = 0;
11343788 2881 if (o->op_flags & OPf_KIDS)
3ad73efd 2882 op_lvalue(cLISTOPo->op_last, type);
a0d0e21e
LW
2883 break;
2884
2885 case OP_NULL:
ddeae0f1 2886 localize = 0;
638bc118
GS
2887 if (o->op_flags & OPf_SPECIAL) /* do BLOCK */
2888 goto nomod;
2889 else if (!(o->op_flags & OPf_KIDS))
463ee0b2 2890 break;
11343788 2891 if (o->op_targ != OP_LIST) {
3ad73efd 2892 op_lvalue(cBINOPo->op_first, type);
a0d0e21e
LW
2893 break;
2894 }
924ba076 2895 /* FALLTHROUGH */
463ee0b2 2896 case OP_LIST:
ddeae0f1 2897 localize = 0;
1ed44841 2898 for (kid = cLISTOPo->op_first; kid; kid = OP_SIBLING(kid))
5c906035
GG
2899 /* elements might be in void context because the list is
2900 in scalar context or because they are attribute sub calls */
2901 if ( (kid->op_flags & OPf_WANT) != OPf_WANT_VOID )
2902 op_lvalue(kid, type);
463ee0b2 2903 break;
78f9721b 2904
1efec5ed
FC
2905 case OP_COREARGS:
2906 return o;
2ec7f6f2
FC
2907
2908 case OP_AND:
2909 case OP_OR:
375879aa
FC
2910 if (type == OP_LEAVESUBLV
2911 || !S_vivifies(cLOGOPo->op_first->op_type))
2912 op_lvalue(cLOGOPo->op_first, type);
2913 if (type == OP_LEAVESUBLV
1ed44841
DM
2914 || !S_vivifies(OP_SIBLING(cLOGOPo->op_first)->op_type))
2915 op_lvalue(OP_SIBLING(cLOGOPo->op_first), type);
2ec7f6f2 2916 goto nomod;
26a50d99
FC
2917
2918 case OP_SREFGEN:
d39c26a6
FC
2919 if (type != OP_AASSIGN && type != OP_SASSIGN
2920 && type != OP_ENTERLOOP)
2921 goto nomod;
7664512e 2922 /* Don’t bother applying lvalue context to the ex-list. */
26a50d99 2923 kid = cUNOPx(cUNOPo->op_first)->op_first;
217e3565
FC
2924 assert (!OP_HAS_SIBLING(kid));
2925 goto kid_2lvref;
2926 case OP_REFGEN:
2927 if (type != OP_AASSIGN) goto nomod;
7664512e
FC
2928 kid = cUNOPo->op_first;
2929 kid_2lvref:
2930 {
2931 const U8 ec = PL_parser ? PL_parser->error_count : 0;
63702de8 2932 S_lvref(aTHX_ kid, type);
7664512e 2933 if (!PL_parser || PL_parser->error_count == ec) {
baabe3fb 2934 if (!FEATURE_REFALIASING_IS_ENABLED)
7664512e 2935 Perl_croak(aTHX_
baabe3fb 2936 "Experimental aliasing via reference not enabled");
7664512e 2937 Perl_ck_warner_d(aTHX_
baabe3fb
FC
2938 packWARN(WARN_EXPERIMENTAL__REFALIASING),
2939 "Aliasing via reference is experimental");
7664512e
FC
2940 }
2941 }
217e3565
FC
2942 if (o->op_type == OP_REFGEN)
2943 op_null(cUNOPx(cUNOPo->op_first)->op_first); /* pushmark */
2944 op_null(o);
26a50d99 2945 return o;
e4e95921
FC
2946
2947 case OP_SPLIT:
2948 kid = cLISTOPo->op_first;
2949 if (kid && kid->op_type == OP_PUSHRE &&
2950 ( kid->op_targ
2951 || o->op_flags & OPf_STACKED
2952#ifdef USE_ITHREADS
2953 || ((PMOP*)kid)->op_pmreplrootu.op_pmtargetoff
2954#else
2955 || ((PMOP*)kid)->op_pmreplrootu.op_pmtargetgv
2956#endif
2957 )) {
2958 /* This is actually @array = split. */
2959 PL_modcount = RETURN_UNLIMITED_NUMBER;
2960 break;
2961 }
2962 goto nomod;
569ddb4a
FC
2963
2964 case OP_SCALAR:
2965 op_lvalue(cUNOPo->op_first, OP_ENTERSUB);
2966 goto nomod;
463ee0b2 2967 }
58d95175 2968
8be1be90
AMS
2969 /* [20011101.069] File test operators interpret OPf_REF to mean that
2970 their argument is a filehandle; thus \stat(".") should not set
2971 it. AMS 20011102 */
2972 if (type == OP_REFGEN &&
ef69c8fc 2973 PL_check[o->op_type] == Perl_ck_ftst)
8be1be90
AMS
2974 return o;
2975
2976 if (type != OP_LEAVESUBLV)
2977 o->op_flags |= OPf_MOD;
2978
2979 if (type == OP_AASSIGN || type == OP_SASSIGN)
2980 o->op_flags |= OPf_SPECIAL|OPf_REF;
ddeae0f1
DM
2981 else if (!type) { /* local() */
2982 switch (localize) {
2983 case 1:
2984 o->op_private |= OPpLVAL_INTRO;
2985 o->op_flags &= ~OPf_SPECIAL;
2986 PL_hints |= HINT_BLOCK_SCOPE;
2987 break;
2988 case 0:
2989 break;
2990 case -1:
a2a5de95
NC
2991 Perl_ck_warner(aTHX_ packWARN(WARN_SYNTAX),
2992 "Useless localization of %s", OP_DESC(o));
ddeae0f1 2993 }
463ee0b2 2994 }
8be1be90
AMS
2995 else if (type != OP_GREPSTART && type != OP_ENTERSUB
2996 && type != OP_LEAVESUBLV)
2997 o->op_flags |= OPf_REF;
11343788 2998 return o;
463ee0b2
LW
2999}
3000
864dbfa3 3001STATIC bool
5f66b61c 3002S_scalar_mod_type(const OP *o, I32 type)
3fe9a6f1
PP
3003{
3004 switch (type) {
32a60974 3005 case OP_POS:
3fe9a6f1 3006 case OP_SASSIGN:
1efec5ed 3007 if (o && o->op_type == OP_RV2GV)
3fe9a6f1 3008 return FALSE;
924ba076 3009 /* FALLTHROUGH */
3fe9a6f1
PP
3010 case OP_PREINC:
3011 case OP_PREDEC:
3012 case OP_POSTINC:
3013 case OP_POSTDEC:
3014 case OP_I_PREINC:
3015 case OP_I_PREDEC:
3016 case OP_I_POSTINC:
3017 case OP_I_POSTDEC:
3018 case OP_POW:
3019 case OP_MULTIPLY:
3020 case OP_DIVIDE:
3021 case OP_MODULO:
3022 case OP_REPEAT:
3023 case OP_ADD:
3024 case OP_SUBTRACT:
3025 case OP_I_MULTIPLY:
3026 case OP_I_DIVIDE:
3027 case OP_I_MODULO:
3028 case OP_I_ADD:
3029 case OP_I_SUBTRACT:
3030 case OP_LEFT_SHIFT:
3031 case OP_RIGHT_SHIFT:
3032 case OP_BIT_AND:
3033 case OP_BIT_XOR:
3034 case OP_BIT_OR:
3035 case OP_CONCAT:
3036 case OP_SUBST:
3037 case OP_TRANS:
bb16bae8 3038 case OP_TRANSR:
49e9fbe6
GS
3039 case OP_READ:
3040 case OP_SYSREAD:
3041 case OP_RECV:
bf4b1e52
GS
3042 case OP_ANDASSIGN:
3043 case OP_ORASSIGN:
410d09fe 3044 case OP_DORASSIGN:
3fe9a6f1
PP
3045 return TRUE;
3046 default:
3047 return FALSE;
3048 }
3049}
3050
35cd451c 3051STATIC bool
5f66b61c 3052S_is_handle_constructor(const OP *o, I32 numargs)
35cd451c 3053{
7918f24d
NC
3054 PERL_ARGS_ASSERT_IS_HANDLE_CONSTRUCTOR;
3055
35cd451c
GS
3056 switch (o->op_type) {
3057 case OP_PIPE_OP:
3058 case OP_SOCKPAIR:
504618e9 3059 if (numargs == 2)
35cd451c 3060 return TRUE;
924ba076 3061 /* FALLTHROUGH */
35cd451c
GS
3062 case OP_SYSOPEN:
3063 case OP_OPEN:
ded8aa31 3064 case OP_SELECT: /* XXX c.f. SelectSaver.pm */
35cd451c
GS
3065 case OP_SOCKET:
3066 case OP_OPEN_DIR:
3067 case OP_ACCEPT:
504618e9 3068 if (numargs == 1)
35cd451c 3069 return TRUE;
5f66b61c 3070 /* FALLTHROUGH */
35cd451c
GS
3071 default:
3072 return FALSE;
3073 }
3074}
3075
0d86688d
NC
3076static OP *
3077S_refkids(pTHX_ OP *o, I32 type)
463ee0b2 3078{
11343788 3079 if (o && o->op_flags & OPf_KIDS) {
6867be6d 3080 OP *kid;
1ed44841 3081 for (kid = cLISTOPo->op_first; kid; kid = OP_SIBLING(kid))
463ee0b2
LW
3082 ref(kid, type);
3083 }
11343788 3084 return o;
463ee0b2
LW
3085}
3086
3087OP *
e4c5ccf3 3088Perl_doref(pTHX_ OP *o, I32 type, bool set_op_ref)
463ee0b2 3089{
27da23d5 3090 dVAR;
463ee0b2 3091 OP *kid;
463ee0b2 3092
7918f24d
NC
3093 PERL_ARGS_ASSERT_DOREF;
3094
13765c85 3095 if (!o || (PL_parser && PL_parser->error_count))
11343788 3096 return o;
463ee0b2 3097
11343788 3098 switch (o->op_type) {
a0d0e21e 3099 case OP_ENTERSUB:
f4df43b5 3100 if ((type == OP_EXISTS || type == OP_DEFINED) &&
11343788 3101 !(o->op_flags & OPf_STACKED)) {
10884df9 3102 CHANGE_TYPE(o, OP_RV2CV); /* entersub => rv2cv */
11343788 3103 assert(cUNOPo->op_first->op_type == OP_NULL);
93c66552 3104 op_null(((LISTOP*)cUNOPo->op_first)->op_first); /* disable pushmark */
11343788 3105 o->op_flags |= OPf_SPECIAL;
8990e307 3106 }
767eda44 3107 else if (type == OP_RV2SV || type == OP_RV2AV || type == OP_RV2HV){
0e9700df
GG
3108 o->op_private |= (type == OP_RV2AV ? OPpDEREF_AV
3109 : type == OP_RV2HV ? OPpDEREF_HV
3110 : OPpDEREF_SV);
767eda44
FC
3111 o->op_flags |= OPf_MOD;
3112 }
3113
8990e307 3114 break;
aeea060c 3115
463ee0b2 3116 case OP_COND_EXPR:
1ed44841 3117 for (kid = OP_SIBLING(cUNOPo->op_first); kid; kid = OP_SIBLING(kid))
e4c5ccf3 3118 doref(kid, type, set_op_ref);
463ee0b2 3119 break;
8990e307 3120 case OP_RV2SV:
35cd451c
GS
3121 if (type == OP_DEFINED)
3122 o->op_flags |= OPf_SPECIAL; /* don't create GV */
e4c5ccf3 3123 doref(cUNOPo->op_first, o->op_type, set_op_ref);
924ba076 3124 /* FALLTHROUGH */
4633a7c4 3125 case OP_PADSV:
5f05dabc 3126 if (type == OP_RV2SV || type == OP_RV2AV || type == OP_RV2HV) {
5dc0d613
MB
3127 o->op_private |= (type == OP_RV2AV ? OPpDEREF_AV
3128 : type == OP_RV2HV ? OPpDEREF_HV
3129 : OPpDEREF_SV);
11343788 3130 o->op_flags |= OPf_MOD;
a0d0e21e 3131 }
8990e307 3132 break;
1c846c1f 3133
463ee0b2
LW
3134 case OP_RV2AV:
3135 case OP_RV2HV:
e4c5ccf3
RH
3136 if (set_op_ref)
3137 o->op_flags |= OPf_REF;
924ba076 3138 /* FALLTHROUGH */
463ee0b2 3139 case OP_RV2GV:
35cd451c
GS
3140 if (type == OP_DEFINED)
3141 o->op_flags |= OPf_SPECIAL; /* don't create GV */
e4c5ccf3 3142 doref(cUNOPo->op_first, o->op_type, set_op_ref);
463ee0b2 3143 break;
8990e307 3144
463ee0b2
LW
3145 case OP_PADAV:
3146 case OP_PADHV:
e4c5ccf3
RH
3147 if (set_op_ref)
3148 o->op_flags |= OPf_REF;
79072805 3149 break;
aeea060c 3150
8990e307 3151 case OP_SCALAR:
79072805 3152 case OP_NULL:
518618af 3153 if (!(o->op_flags & OPf_KIDS) || type == OP_DEFINED)
463ee0b2 3154 break;
e4c5ccf3 3155 doref(cBINOPo->op_first, type, set_op_ref);
79072805
LW
3156 break;
3157 case OP_AELEM:
3158 case OP_HELEM:
e4c5ccf3 3159 doref(cBINOPo->op_first, o->op_type, set_op_ref);
5f05dabc 3160 if (type == OP_RV2SV || type == OP_RV2AV || type == OP_RV2HV) {
5dc0d613
MB
3161 o->op_private |= (type == OP_RV2AV ? OPpDEREF_AV
3162 : type == OP_RV2HV ? OPpDEREF_HV
3163 : OPpDEREF_SV);
11343788 3164 o->op_flags |= OPf_MOD;
8990e307 3165 }
79072805
LW
3166 break;
3167
463ee0b2 3168 case OP_SCOPE:
79072805 3169 case OP_LEAVE:
e4c5ccf3 3170 set_op_ref = FALSE;
924ba076 3171 /* FALLTHROUGH */
79072805 3172 case OP_ENTER:
8990e307 3173 case OP_LIST:
11343788 3174 if (!(o->op_flags & OPf_KIDS))
79072805 3175 break;
e4c5ccf3 3176 doref(cLISTOPo->op_last, type, set_op_ref);
79072805 3177 break;
a0d0e21e
LW
3178 default:
3179 break;
79072805 3180 }
11343788 3181 return scalar(o);
8990e307 3182
79072805
LW
3183}
3184
09bef843
SB
3185STATIC OP *
3186S_dup_attrlist(pTHX_ OP *o)
3187{
0bd48802 3188 OP *rop;
09bef843 3189
7918f24d
NC
3190 PERL_ARGS_ASSERT_DUP_ATTRLIST;
3191
09bef843
SB
3192 /* An attrlist is either a simple OP_CONST or an OP_LIST with kids,
3193 * where the first kid is OP_PUSHMARK and the remaining ones
3194 * are OP_CONST. We need to push the OP_CONST values.
3195 */
3196 if (o->op_type == OP_CONST)
b37c2d43 3197 rop = newSVOP(OP_CONST, o->op_flags, SvREFCNT_inc_NN(cSVOPo->op_sv));
09bef843
SB
3198 else {
3199 assert((o->op_type == OP_LIST) && (o->op_flags & OPf_KIDS));
5f66b61c 3200 rop = NULL;
1ed44841 3201 for (o = cLISTOPo->op_first; o; o = OP_SIBLING(o)) {
09bef843 3202 if (o->op_type == OP_CONST)
2fcb4757 3203 rop = op_append_elem(OP_LIST, rop,
09bef843 3204 newSVOP(OP_CONST, o->op_flags,
b37c2d43 3205 SvREFCNT_inc_NN(cSVOPo->op_sv)));
09bef843
SB
3206 }
3207 }
3208 return rop;
3209}
3210
3211STATIC void
ad0dc73b 3212S_apply_attrs(pTHX_ HV *stash, SV *target, OP *attrs)
09bef843 3213{
ad0dc73b 3214 SV * const stashsv = stash ? newSVhek(HvNAME_HEK(stash)) : &PL_sv_no;
09bef843 3215
7918f24d
NC
3216 PERL_ARGS_ASSERT_APPLY_ATTRS;
3217
09bef843 3218 /* fake up C<use attributes $pkg,$rv,@attrs> */
e4783991 3219
09bef843 3220#define ATTRSMODULE "attributes"
95f0a2f1
SB
3221#define ATTRSMODULE_PM "attributes.pm"
3222
ad0dc73b 3223 Perl_load_module(aTHX_ PERL_LOADMOD_IMPORT_OPS,
6136c704
AL
3224 newSVpvs(ATTRSMODULE),
3225 NULL,
2fcb4757 3226 op_prepend_elem(OP_LIST,
95f0a2f1 3227 newSVOP(OP_CONST, 0, stashsv),
2fcb4757 3228 op_prepend_elem(OP_LIST,
95f0a2f1
SB
3229 newSVOP(OP_CONST, 0,
3230 newRV(target)),
3231 dup_attrlist(attrs))));
09bef843
SB
3232}
3233
95f0a2f1
SB
3234STATIC void
3235S_apply_attrs_my(pTHX_ HV *stash, OP *target, OP *attrs, OP **imopsp)
3236{
3237 OP *pack, *imop, *arg;
ad0dc73b 3238 SV *meth, *stashsv, **svp;
95f0a2f1 3239
7918f24d
NC
3240 PERL_ARGS_ASSERT_APPLY_ATTRS_MY;
3241
95f0a2f1
SB
3242 if (!attrs)
3243 return;
3244
3245 assert(target->op_type == OP_PADSV ||
3246 target->op_type == OP_PADHV ||
3247 target->op_type == OP_PADAV);
3248
3249 /* Ensure that attributes.pm is loaded. */
ad0dc73b
FC
3250 /* Don't force the C<use> if we don't need it. */
3251 svp = hv_fetchs(GvHVn(PL_incgv), ATTRSMODULE_PM, FALSE);
3252 if (svp && *svp != &PL_sv_undef)
3253 NOOP; /* already in %INC */
3254 else
3255 Perl_load_module(aTHX_ PERL_LOADMOD_NOIMPORT,
3256 newSVpvs(ATTRSMODULE), NULL);
95f0a2f1
SB
3257
3258 /* Need package name for method call. */
6136c704 3259 pack = newSVOP(OP_CONST, 0, newSVpvs(ATTRSMODULE));
95f0a2f1
SB
3260
3261 /* Build up the real arg-list. */
5aaec2b4
NC
3262 stashsv = stash ? newSVhek(HvNAME_HEK(stash)) : &PL_sv_no;
3263
95f0a2f1
SB
3264 arg = newOP(OP_PADSV, 0);
3265 arg->op_targ = target->op_targ;
2fcb4757 3266 arg = op_prepend_elem(OP_LIST,
95f0a2f1 3267 newSVOP(OP_CONST, 0, stashsv),
2fcb4757 3268 op_prepend_elem(OP_LIST,
95f0a2f1 3269 newUNOP(OP_REFGEN, 0,
3ad73efd 3270 op_lvalue(arg, OP_REFGEN)),
95f0a2f1
SB
3271 dup_attrlist(attrs)));
3272
3273 /* Fake up a method call to import */
18916d0d 3274 meth = newSVpvs_share("import");
03d05f6e 3275 imop = op_convert_list(OP_ENTERSUB, OPf_STACKED|OPf_SPECIAL|OPf_WANT_VOID,
2fcb4757 3276 op_append_elem(OP_LIST,
6aa68307 3277 op_prepend_elem(OP_LIST, pack, arg),
b46e009d 3278 newMETHOP_named(OP_METHOD_NAMED, 0, meth)));
95f0a2f1
SB
3279
3280 /* Combine the ops. */
2fcb4757 3281 *imopsp = op_append_elem(OP_LIST, *imopsp, imop);
95f0a2f1
SB
3282}
3283
3284/*
3285=notfor apidoc apply_attrs_string
3286
3287Attempts to apply a list of attributes specified by the C<attrstr> and
3288C<len> arguments to the subroutine identified by the C<cv> argument which
3289is expected to be associated with the package identified by the C<stashpv>
3290argument (see L<attributes>). It gets this wrong, though, in that it
3291does not correctly identify the boundaries of the individual attribute
3292specifications within C<attrstr>. This is not really intended for the
3293public API, but has to be listed here for systems such as AIX which
3294need an explicit export list for symbols. (It's called from XS code
3295in support of the C<ATTRS:> keyword from F<xsubpp>.) Patches to fix it
3296to respect attribute syntax properly would be welcome.
3297
3298=cut
3299*/
3300
be3174d2 3301void
6867be6d
AL
3302Perl_apply_attrs_string(pTHX_ const char *stashpv, CV *cv,
3303 const char *attrstr, STRLEN len)
be3174d2 3304{
5f66b61c 3305 OP *attrs = NULL;
be3174d2 3306
7918f24d
NC
3307 PERL_ARGS_ASSERT_APPLY_ATTRS_STRING;
3308
be3174d2
GS
3309 if (!len) {
3310 len = strlen(attrstr);
3311 }
3312
3313 while (len) {
3314 for (; isSPACE(*attrstr) && len; --len, ++attrstr) ;
3315 if (len) {
890ce7af 3316 const char * const sstr = attrstr;
be3174d2 3317 for (; !isSPACE(*attrstr) && len; --len, ++attrstr) ;
2fcb4757 3318 attrs = op_append_elem(OP_LIST, attrs,
be3174d2
GS
3319 newSVOP(OP_CONST, 0,
3320 newSVpvn(sstr, attrstr-sstr)));
3321 }
3322 }
3323
3324 Perl_load_module(aTHX_ PERL_LOADMOD_IMPORT_OPS,
6136c704 3325 newSVpvs(ATTRSMODULE),
2fcb4757 3326 NULL, op_prepend_elem(OP_LIST,
be3174d2 3327 newSVOP(OP_CONST, 0, newSVpv(stashpv,0)),
2fcb4757 3328 op_prepend_elem(OP_LIST,
be3174d2 3329 newSVOP(OP_CONST, 0,
ad64d0ec 3330 newRV(MUTABLE_SV(cv))),
be3174d2
GS
3331 attrs)));
3332}
3333
eedb00fa
PM
3334STATIC void
3335S_move_proto_attr(pTHX_ OP **proto, OP **attrs, const GV * name)
3336{
3337 OP *new_proto = NULL;
3338 STRLEN pvlen;
3339 char *pv;
3340 OP *o;
3341
3342 PERL_ARGS_ASSERT_MOVE_PROTO_ATTR;
3343
3344 if (!*attrs)
3345 return;
3346
3347 o = *attrs;
3348 if (o->op_type == OP_CONST) {
3349 pv = SvPV(cSVOPo_sv, pvlen);
3350 if (pvlen >= 10 && memEQ(pv, "prototype(", 10)) {
3351 SV * const tmpsv = newSVpvn_flags(pv + 10, pvlen - 11, SvUTF8(cSVOPo_sv));
3352 SV ** const tmpo = cSVOPx_svp(o);
3353 SvREFCNT_dec(cSVOPo_sv);
3354 *tmpo = tmpsv;
3355 new_proto = o;
3356 *attrs = NULL;
3357 }
3358 } else if (o->op_type == OP_LIST) {
e78bc664 3359 OP * lasto;
eedb00fa 3360 assert(o->op_flags & OPf_KIDS);
e78bc664
PM
3361 lasto = cLISTOPo->op_first;
3362 assert(lasto->op_type == OP_PUSHMARK);
1ed44841 3363 for (o = OP_SIBLING(lasto); o; o = OP_SIBLING(o)) {
eedb00fa
PM
3364 if (o->op_type == OP_CONST) {
3365 pv = SvPV(cSVOPo_sv, pvlen);
3366 if (pvlen >= 10 && memEQ(pv, "prototype(", 10)) {
3367 SV * const tmpsv = newSVpvn_flags(pv + 10, pvlen - 11, SvUTF8(cSVOPo_sv));
3368 SV ** const tmpo = cSVOPx_svp(o);
3369 SvREFCNT_dec(cSVOPo_sv);
3370 *tmpo = tmpsv;
3371 if (new_proto && ckWARN(WARN_MISC)) {
3372 STRLEN new_len;
3373 const char * newp = SvPV(cSVOPo_sv, new_len);
3374 Perl_warner(aTHX_ packWARN(WARN_MISC),
3375 "Attribute prototype(%"UTF8f") discards earlier prototype attribute in same sub",
3376 UTF8fARG(SvUTF8(cSVOPo_sv), new_len, newp));
3377 op_free(new_proto);
3378 }
3379 else if (new_proto)
3380 op_free(new_proto);
3381 new_proto = o;
3253bf85
DM
3382 /* excise new_proto from the list */
3383 op_sibling_splice(*attrs, lasto, 1, NULL);
3384 o = lasto;
eedb00fa
PM
3385 continue;
3386 }
3387 }
3388 lasto = o;
3389 }
3390 /* If the list is now just the PUSHMARK, scrap the whole thing; otherwise attributes.xs
3391 would get pulled in with no real need */
1ed44841 3392 if (!OP_HAS_SIBLING(cLISTOPx(*attrs)->op_first)) {
eedb00fa
PM
3393 op_free(*attrs);
3394 *attrs = NULL;
3395 }
3396 }
3397
3398 if (new_proto) {
3399 SV *svname;
3400 if (isGV(name)) {
3401 svname = sv_newmortal();
3402 gv_efullname3(svname, name, NULL);
3403 }
3404 else if (SvPOK(name) && *SvPVX((SV *)name) == '&')
3405 svname = newSVpvn_flags(SvPVX((SV *)name)+1, SvCUR(name)-1, SvUTF8(name)|SVs_TEMP);
3406 else
3407 svname = (SV *)name;
3408 if (ckWARN(WARN_ILLEGALPROTO))
3409 (void)validate_proto(svname, cSVOPx_sv(new_proto), TRUE);
3410 if (*proto && ckWARN(WARN_PROTOTYPE)) {
3411 STRLEN old_len, new_len;
3412 const char * oldp = SvPV(cSVOPx_sv(*proto), old_len);
3413 const char * newp = SvPV(cSVOPx_sv(new_proto), new_len);
3414
3415 Perl_warner(aTHX_ packWARN(WARN_PROTOTYPE),
3416 "Prototype '%"UTF8f"' overridden by attribute 'prototype(%"UTF8f")'"
3417 " in %"SVf,
3418 UTF8fARG(SvUTF8(cSVOPx_sv(*proto)), old_len, oldp),
3419 UTF8fARG(SvUTF8(cSVOPx_sv(new_proto)), new_len, newp),
3420 SVfARG(svname));
3421 }
3422 if (*proto)
3423 op_free(*proto);
3424 *proto = new_proto;
3425 }
3426}
3427
92bd82a0
FC
3428static void
3429S_cant_declare(pTHX_ OP *o)
3430{
4748e002
FC
3431 if (o->op_type == OP_NULL
3432 && (o->op_flags & (OPf_SPECIAL|OPf_KIDS)) == OPf_KIDS)
3433 o = cUNOPo->op_first;
92bd82a0 3434 yyerror(Perl_form(aTHX_ "Can't declare %s in \"%s\"",
4748e002
FC
3435 o->op_type == OP_NULL
3436 && o->op_flags & OPf_SPECIAL
3437 ? "do block"
3438 : OP_DESC(o),
92bd82a0
FC
3439 PL_parser->in_my == KEY_our ? "our" :
3440 PL_parser->in_my == KEY_state ? "state" :
3441 "my"));
3442}
3443
09bef843 3444STATIC OP *
95f0a2f1 3445S_my_kid(pTHX_ OP *o, OP *attrs, OP **imopsp)
93a17b20 3446{
93a17b20 3447 I32 type;
a1fba7eb 3448 const bool stately = PL_parser && PL_parser->in_my == KEY_state;
93a17b20 3449
7918f24d
NC
3450 PERL_ARGS_ASSERT_MY_KID;
3451
13765c85 3452 if (!o || (PL_parser && PL_parser->error_count))
11343788 3453 return o;
93a17b20 3454
bc61e325 3455 type = o->op_type;
eb8433b7 3456
93a17b20 3457 if (type == OP_LIST) {
6867be6d 3458 OP *kid;
1ed44841 3459 for (kid = cLISTOPo->op_first; kid; kid = OP_SIBLING(kid))
95f0a2f1 3460 my_kid(kid, attrs, imopsp);
0865059d 3461 return o;
8b8c1fb9 3462 } else if (type == OP_UNDEF || type == OP_STUB) {
7766148a 3463 return o;
77ca0c92
LW
3464 } else if (type == OP_RV2SV || /* "our" declaration */
3465 type == OP_RV2AV ||
3466 type == OP_RV2HV) { /* XXX does this let anything illegal in? */
1ce0b88c 3467 if (cUNOPo->op_first->op_type != OP_GV) { /* MJD 20011224 */
92bd82a0 3468 S_cant_declare(aTHX_ o);
1ce0b88c 3469 } else if (attrs) {
551405c4 3470 GV * const gv = cGVOPx_gv(cUNOPo->op_first);
316ebaf2 3471 assert(PL_parser);
12bd6ede
DM
3472 PL_parser->in_my = FALSE;
3473 PL_parser->in_my_stash = NULL;
1ce0b88c
RGS
3474 apply_attrs(GvSTASH(gv),
3475 (type == OP_RV2SV ? GvSV(gv) :
ad64d0ec
NC
3476 type == OP_RV2AV ? MUTABLE_SV(GvAV(gv)) :
3477 type == OP_RV2HV ? MUTABLE_SV(GvHV(gv)) : MUTABLE_SV(gv)),
ad0dc73b 3478 attrs);
1ce0b88c 3479 }
192587c2 3480 o->op_private |= OPpOUR_INTRO;
77ca0c92 3481 return o;
95f0a2f1
SB
3482 }
3483 else if (type != OP_PADSV &&
93a17b20
LW
3484 type != OP_PADAV &&
3485 type != OP_PADHV &&
3486 type != OP_PUSHMARK)
3487 {
92bd82a0 3488 S_cant_declare(aTHX_ o);
11343788 3489 return o;
93a17b20 3490 }
09bef843
SB
3491 else if (attrs && type != OP_PUSHMARK) {
3492 HV *stash;
09bef843 3493
316ebaf2 3494 assert(PL_parser);
12bd6ede
DM
3495 PL_parser->in_my = FALSE;
3496 PL_parser->in_my_stash = NULL;
eb64745e 3497
09bef843 3498 /* check for C<my Dog $spot> when deciding package */
dd2155a4
DM
3499 stash = PAD_COMPNAME_TYPE(o->op_targ);
3500 if (!stash)
09bef843 3501 stash = PL_curstash;
95f0a2f1 3502 apply_attrs_my(stash, o, attrs, imopsp);
09bef843 3503 }
11343788
MB
3504 o->op_flags |= OPf_MOD;
3505 o->op_private |= OPpLVAL_INTRO;
a1fba7eb 3506 if (stately)
952306ac 3507 o->op_private |= OPpPAD_STATE;
11343788 3508 return o;
93a17b20
LW
3509}
3510
3511OP *
09bef843
SB
3512Perl_my_attrs(pTHX_ OP *o, OP *attrs)
3513{
0bd48802 3514 OP *rops;
95f0a2f1
SB
3515 int maybe_scalar = 0;
3516
7918f24d
NC
3517 PERL_ARGS_ASSERT_MY_ATTRS;
3518
d2be0de5 3519/* [perl #17376]: this appears to be premature, and results in code such as
c754c3d7 3520 C< our(%x); > executing in list mode rather than void mode */
d2be0de5 3521#if 0
09bef843
SB
3522 if (o->op_flags & OPf_PARENS)
3523 list(o);
95f0a2f1
SB
3524 else
3525 maybe_scalar = 1;
d2be0de5
YST
3526#else
3527 maybe_scalar = 1;
3528#endif
09bef843
SB
3529 if (attrs)
3530 SAVEFREEOP(attrs);
5f66b61c 3531 rops = NULL;
95f0a2f1
SB
3532 o = my_kid(o, attrs, &rops);
3533 if (rops) {
3534 if (maybe_scalar && o->op_type == OP_PADSV) {
2fcb4757 3535 o = scalar(op_append_list(OP_LIST, rops, o));
95f0a2f1
SB
3536 o->op_private |= OPpLVAL_INTRO;
3537 }
f5d1ed10
FC
3538 else {
3539 /* The listop in rops might have a pushmark at the beginning,
3540 which will mess up list assignment. */
3541 LISTOP * const lrops = (LISTOP *)rops; /* for brevity */
3542 if (rops->op_type == OP_LIST &&
3543 lrops->op_first && lrops->op_first->op_type == OP_PUSHMARK)
3544 {
3545 OP * const pushmark = lrops->op_first;
3253bf85
DM
3546 /* excise pushmark */
3547 op_sibling_splice(rops, NULL, 1, NULL);
f5d1ed10
FC
3548 op_free(pushmark);
3549 }
2fcb4757 3550 o = op_append_list(OP_LIST, o, rops);
f5d1ed10 3551 }
95f0a2f1 3552 }
12bd6ede
DM
3553 PL_parser->in_my = FALSE;
3554 PL_parser->in_my_stash = NULL;
eb64745e 3555 return o;
09bef843
SB
3556}
3557
3558OP *
864dbfa3 3559Perl_sawparens(pTHX_ OP *o)
79072805 3560{
96a5add6 3561 PERL_UNUSED_CONTEXT;
79072805
LW
3562 if (o)
3563 o->op_flags |= OPf_PARENS;
3564 return o;
3565}
3566
3567OP *
864dbfa3 3568Perl_bind_match(pTHX_ I32 type, OP *left, OP *right)
79072805 3569{
11343788 3570 OP *o;
59f00321 3571 bool ismatchop = 0;
1496a290
AL
3572 const OPCODE ltype = left->op_type;
3573 const OPCODE rtype = right->op_type;
79072805 3574
7918f24d
NC
3575 PERL_ARGS_ASSERT_BIND_MATCH;
3576
1496a290
AL
3577 if ( (ltype == OP_RV2AV || ltype == OP_RV2HV || ltype == OP_PADAV
3578 || ltype == OP_PADHV) && ckWARN(WARN_MISC))
041457d9 3579 {
1496a290 3580 const char * const desc
bb16bae8
FC
3581 = PL_op_desc[(
3582 rtype == OP_SUBST || rtype == OP_TRANS
3583 || rtype == OP_TRANSR
3584 )
666ea192 3585 ? (int)rtype : OP_MATCH];
c6771ab6 3586 const bool isary = ltype == OP_RV2AV || ltype == OP_PADAV;
c6771ab6 3587 SV * const name =
0920b7fa 3588 S_op_varname(aTHX_ left);
c6771ab6
FC
3589 if (name)
3590 Perl_warner(aTHX_ packWARN(WARN_MISC),
3591 "Applying %s to %"SVf" will act on scalar(%"SVf")",
c1f6cd39 3592 desc, SVfARG(name), SVfARG(name));
c6771ab6
FC
3593 else {
3594 const char * const sample = (isary
666ea192 3595 ? "@array" : "%hash");
c6771ab6 3596 Perl_warner(aTHX_ packWARN(WARN_MISC),
1c846c1f 3597 "Applying %s to %s will act on scalar(%s)",
599cee73 3598 desc, sample, sample);
c6771ab6 3599 }
2ae324a7
PP
3600 }
3601
1496a290 3602 if (rtype == OP_CONST &&
5cc9e5c9
RH
3603 cSVOPx(right)->op_private & OPpCONST_BARE &&
3604 cSVOPx(right)->op_private & OPpCONST_STRICT)
3605 {
3606 no_bareword_allowed(right);
3607 }
3608
bb16bae8 3609 /* !~ doesn't make sense with /r, so error on it for now */
4f4d7508
DC
3610 if (rtype == OP_SUBST && (cPMOPx(right)->op_pmflags & PMf_NONDESTRUCT) &&
3611 type == OP_NOT)
ce0e31fe 3612 /* diag_listed_as: Using !~ with %s doesn't make sense */
4f4d7508 3613 yyerror("Using !~ with s///r doesn't make sense");
bb16bae8 3614 if (rtype == OP_TRANSR && type == OP_NOT)
ce0e31fe 3615 /* diag_listed_as: Using !~ with %s doesn't make sense */
bb16bae8 3616 yyerror("Using !~ with tr///r doesn't make sense");
4f4d7508 3617
2474a784
FC
3618 ismatchop = (rtype == OP_MATCH ||
3619 rtype == OP_SUBST ||
bb16bae8 3620 rtype == OP_TRANS || rtype == OP_TRANSR)
2474a784 3621 && !(right->op_flags & OPf_SPECIAL);
59f00321
RGS
3622 if (ismatchop && right->op_private & OPpTARGET_MY) {
3623 right->op_targ = 0;
3624 right->op_private &= ~OPpTARGET_MY;
3625 }
05a502dc 3626 if (!(right->op_flags & OPf_STACKED) && !right->op_targ && ismatchop) {
05a502dc
FC
3627 if (left->op_type == OP_PADSV
3628 && !(left->op_private & OPpLVAL_INTRO))
3629 {
3630 right->op_targ = left->op_targ;
3631 op_free(left);
3632 o = right;
3633 }
3634 else {
3635 right->op_flags |= OPf_STACKED;
3636 if (rtype != OP_MATCH && rtype != OP_TRANSR &&
1496a290 3637 ! (rtype == OP_TRANS &&
4f4d7508
DC
3638 right->op_private & OPpTRANS_IDENTICAL) &&
3639 ! (rtype == OP_SUBST &&
3640 (cPMOPx(right)->op_pmflags & PMf_NONDESTRUCT)))
a5b2ef19 3641 left = op_lvalue(left, rtype);
05a502dc 3642 if (right->op_type == OP_TRANS || right->op_type == OP_TRANSR)
a5b2ef19 3643 o = newBINOP(OP_NULL, OPf_STACKED, scalar(left), right);
05a502dc 3644 else
a5b2ef19 3645 o = op_prepend_elem(rtype, scalar(left), right);
05a502dc 3646 }
79072805 3647 if (type == OP_NOT)
11343788
MB
3648 return newUNOP(OP_NOT, 0, scalar(o));
3649 return o;
79072805
LW
3650 }
3651 else
3652 return bind_match(type, left,
d63c20f2 3653 pmruntime(newPMOP(OP_MATCH, 0), right, 0, 0));
79072805
LW
3654}
3655
3656OP *
864dbfa3 3657Perl_invert(pTHX_ OP *o)
79072805 3658{
11343788 3659 if (!o)
1d866c12 3660 return NULL;
11343788 3661 return newUNOP(OP_NOT, OPf_SPECIAL, scalar(o));
79072805
LW
3662}
3663
3ad73efd
Z
3664/*
3665=for apidoc Amx|OP *|op_scope|OP *o
3666
3667Wraps up an op tree with some additional ops so that at runtime a dynamic
3668scope will be created. The original ops run in the new dynamic scope,
3669and then, provided that they exit normally, the scope will be unwound.
3670The additional ops used to create and unwind the dynamic scope will
3671normally be an C<enter>/C<leave> pair, but a C<scope> op may be used
3672instead if the ops are simple enough to not need the full dynamic scope
3673structure.
3674
3675=cut
3676*/
3677
79072805 3678OP *
3ad73efd 3679Perl_op_scope(pTHX_ OP *o)
79072805 3680{
27da23d5 3681 dVAR;
79072805 3682 if (o) {
284167a5 3683 if (o->op_flags & OPf_PARENS || PERLDB_NOOPT || TAINTING_get) {
2fcb4757 3684 o = op_prepend_elem(OP_LINESEQ, newOP(OP_ENTER, 0), o);
10884df9 3685 CHANGE_TYPE(o, OP_LEAVE);
463ee0b2 3686 }
fdb22418
HS
3687 else if (o->op_type == OP_LINESEQ) {
3688 OP *kid;
10884df9 3689 CHANGE_TYPE(o, OP_SCOPE);
fdb22418 3690 kid = ((LISTOP*)o)->op_first;
59110972 3691 if (kid->op_type == OP_NEXTSTATE || kid->op_type == OP_DBSTATE) {
fdb22418 3692 op_null(kid);
59110972
RH
3693
3694 /* The following deals with things like 'do {1 for 1}' */
1ed44841 3695 kid = OP_SIBLING(kid);
59110972
RH
3696 if (kid &&
3697 (kid->op_type == OP_NEXTSTATE || kid->op_type == OP_DBSTATE))
3698 op_null(kid);
3699 }
463ee0b2 3700 }
fdb22418 3701 else
5f66b61c 3702 o = newLISTOP(OP_SCOPE, 0, o, NULL);
79072805
LW
3703 }