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(perl #133575) prevent set/longjmp clobbering locals in S_fold_constants
[perl5.git] / op.c
CommitLineData
4b88f280 1#line 2 "op.c"
a0d0e21e 2/* op.c
79072805 3 *
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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
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10 */
11
12/*
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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
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22/* This file contains the functions that create, manipulate and optimize
23 * the OP structures that hold a compiled perl program.
24 *
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25 * Note that during the build of miniperl, a temporary copy of this file
26 * is made, called opmini.c.
27 *
28 * A Perl program is compiled into a tree of OP nodes. Each op contains:
29 * * structural OP pointers to its children and siblings (op_sibling,
30 * op_first etc) that define the tree structure;
31 * * execution order OP pointers (op_next, plus sometimes op_other,
32 * op_lastop etc) that define the execution sequence plus variants;
33 * * a pointer to the C "pp" function that would execute the op;
34 * * any data specific to that op.
35 * For example, an OP_CONST op points to the pp_const() function and to an
36 * SV containing the constant value. When pp_const() is executed, its job
37 * is to push that SV onto the stack.
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DM
38 *
39 * OPs are mainly created by the newFOO() functions, which are mainly
40 * called from the parser (in perly.y) as the code is parsed. For example
41 * the Perl code $a + $b * $c would cause the equivalent of the following
42 * to be called (oversimplifying a bit):
43 *
44 * newBINOP(OP_ADD, flags,
45 * newSVREF($a),
46 * newBINOP(OP_MULTIPLY, flags, newSVREF($b), newSVREF($c))
47 * )
48 *
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DM
49 * As the parser reduces low-level rules, it creates little op subtrees;
50 * as higher-level rules are resolved, these subtrees get joined together
51 * as branches on a bigger subtree, until eventually a top-level rule like
52 * a subroutine definition is reduced, at which point there is one large
53 * parse tree left.
54 *
55 * The execution order pointers (op_next) are generated as the subtrees
56 * are joined together. Consider this sub-expression: A*B + C/D: at the
57 * point when it's just been parsed, the op tree looks like:
58 *
59 * [+]
60 * |
61 * [*]------[/]
62 * | |
63 * A---B C---D
64 *
65 * with the intended execution order being:
66 *
67 * [PREV] => A => B => [*] => C => D => [/] => [+] => [NEXT]
68 *
69 * At this point all the nodes' op_next pointers will have been set,
70 * except that:
71 * * we don't know what the [NEXT] node will be yet;
72 * * we don't know what the [PREV] node will be yet, but when it gets
73 * created and needs its op_next set, it needs to be set to point to
74 * A, which is non-obvious.
75 * To handle both those cases, we temporarily set the top node's
76 * op_next to point to the first node to be executed in this subtree (A in
77 * this case). This means that initially a subtree's op_next chain,
78 * starting from the top node, will visit each node in execution sequence
79 * then point back at the top node.
80 * When we embed this subtree in a larger tree, its top op_next is used
81 * to get the start node, then is set to point to its new neighbour.
82 * For example the two separate [*],A,B and [/],C,D subtrees would
83 * initially have had:
84 * [*] => A; A => B; B => [*]
85 * and
86 * [/] => C; C => D; D => [/]
87 * When these two subtrees were joined together to make the [+] subtree,
88 * [+]'s op_next was set to [*]'s op_next, i.e. A; then [*]'s op_next was
89 * set to point to [/]'s op_next, i.e. C.
90 *
91 * This op_next linking is done by the LINKLIST() macro and its underlying
92 * op_linklist() function. Given a top-level op, if its op_next is
93 * non-null, it's already been linked, so leave it. Otherwise link it with
94 * its children as described above, possibly recursively if any of the
95 * children have a null op_next.
96 *
97 * In summary: given a subtree, its top-level node's op_next will either
98 * be:
99 * NULL: the subtree hasn't been LINKLIST()ed yet;
100 * fake: points to the start op for this subtree;
101 * real: once the subtree has been embedded into a larger tree
166f8a29 102 */
ccfc67b7 103
61b743bb 104/*
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105
106Here's an older description from Larry.
107
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108Perl's compiler is essentially a 3-pass compiler with interleaved phases:
109
110 A bottom-up pass
111 A top-down pass
112 An execution-order pass
113
114The bottom-up pass is represented by all the "newOP" routines and
115the ck_ routines. The bottom-upness is actually driven by yacc.
116So at the point that a ck_ routine fires, we have no idea what the
117context is, either upward in the syntax tree, or either forward or
118backward in the execution order. (The bottom-up parser builds that
119part of the execution order it knows about, but if you follow the "next"
120links around, you'll find it's actually a closed loop through the
ef9da979 121top level node.)
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122
123Whenever the bottom-up parser gets to a node that supplies context to
124its components, it invokes that portion of the top-down pass that applies
125to that part of the subtree (and marks the top node as processed, so
126if a node further up supplies context, it doesn't have to take the
127plunge again). As a particular subcase of this, as the new node is
128built, it takes all the closed execution loops of its subcomponents
129and links them into a new closed loop for the higher level node. But
130it's still not the real execution order.
131
132The actual execution order is not known till we get a grammar reduction
133to a top-level unit like a subroutine or file that will be called by
134"name" rather than via a "next" pointer. At that point, we can call
135into peep() to do that code's portion of the 3rd pass. It has to be
136recursive, but it's recursive on basic blocks, not on tree nodes.
137*/
138
06e0342d 139/* To implement user lexical pragmas, there needs to be a way at run time to
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140 get the compile time state of %^H for that block. Storing %^H in every
141 block (or even COP) would be very expensive, so a different approach is
142 taken. The (running) state of %^H is serialised into a tree of HE-like
143 structs. Stores into %^H are chained onto the current leaf as a struct
144 refcounted_he * with the key and the value. Deletes from %^H are saved
145 with a value of PL_sv_placeholder. The state of %^H at any point can be
146 turned back into a regular HV by walking back up the tree from that point's
06e0342d 147 leaf, ignoring any key you've already seen (placeholder or not), storing
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NC
148 the rest into the HV structure, then removing the placeholders. Hence
149 memory is only used to store the %^H deltas from the enclosing COP, rather
150 than the entire %^H on each COP.
151
152 To cause actions on %^H to write out the serialisation records, it has
153 magic type 'H'. This magic (itself) does nothing, but its presence causes
154 the values to gain magic type 'h', which has entries for set and clear.
c28fe1ec 155 C<Perl_magic_sethint> updates C<PL_compiling.cop_hints_hash> with a store
34795b44 156 record, with deletes written by C<Perl_magic_clearhint>. C<SAVEHINTS>
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157 saves the current C<PL_compiling.cop_hints_hash> on the save stack, so that
158 it will be correctly restored when any inner compiling scope is exited.
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159*/
160
79072805 161#include "EXTERN.h"
864dbfa3 162#define PERL_IN_OP_C
79072805 163#include "perl.h"
77ca0c92 164#include "keywords.h"
2846acbf 165#include "feature.h"
74529a43 166#include "regcomp.h"
79072805 167
16c91539 168#define CALL_PEEP(o) PL_peepp(aTHX_ o)
1a0a2ba9 169#define CALL_RPEEP(o) PL_rpeepp(aTHX_ o)
16c91539 170#define CALL_OPFREEHOOK(o) if (PL_opfreehook) PL_opfreehook(aTHX_ o)
a2efc822 171
5068f264 172static const char array_passed_to_stat[] = "Array passed to stat will be coerced to a scalar";
637494ac 173
aa9d1253
TC
174/* Used to avoid recursion through the op tree in scalarvoid() and
175 op_free()
176*/
177
178#define DEFERRED_OP_STEP 100
179#define DEFER_OP(o) \
180 STMT_START { \
181 if (UNLIKELY(defer_ix == (defer_stack_alloc-1))) { \
182 defer_stack_alloc += DEFERRED_OP_STEP; \
183 assert(defer_stack_alloc > 0); \
184 Renew(defer_stack, defer_stack_alloc, OP *); \
185 } \
186 defer_stack[++defer_ix] = o; \
187 } STMT_END
188
189#define POP_DEFERRED_OP() (defer_ix >= 0 ? defer_stack[defer_ix--] : (OP *)NULL)
190
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191/* remove any leading "empty" ops from the op_next chain whose first
192 * node's address is stored in op_p. Store the updated address of the
193 * first node in op_p.
194 */
195
196STATIC void
dc3bf405 197S_prune_chain_head(OP** op_p)
72621f84
DM
198{
199 while (*op_p
200 && ( (*op_p)->op_type == OP_NULL
201 || (*op_p)->op_type == OP_SCOPE
202 || (*op_p)->op_type == OP_SCALAR
203 || (*op_p)->op_type == OP_LINESEQ)
204 )
205 *op_p = (*op_p)->op_next;
206}
207
208
8be227ab
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209/* See the explanatory comments above struct opslab in op.h. */
210
7aef8e5b 211#ifdef PERL_DEBUG_READONLY_OPS
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212# define PERL_SLAB_SIZE 128
213# define PERL_MAX_SLAB_SIZE 4096
214# include <sys/mman.h>
7aef8e5b 215#endif
3107b51f 216
7aef8e5b 217#ifndef PERL_SLAB_SIZE
8be227ab 218# define PERL_SLAB_SIZE 64
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FC
219#endif
220#ifndef PERL_MAX_SLAB_SIZE
e6cee8c0 221# define PERL_MAX_SLAB_SIZE 2048
7aef8e5b 222#endif
8be227ab
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223
224/* rounds up to nearest pointer */
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225#define SIZE_TO_PSIZE(x) (((x) + sizeof(I32 *) - 1)/sizeof(I32 *))
226#define DIFF(o,p) ((size_t)((I32 **)(p) - (I32**)(o)))
8be227ab
FC
227
228static OPSLAB *
229S_new_slab(pTHX_ size_t sz)
230{
7aef8e5b 231#ifdef PERL_DEBUG_READONLY_OPS
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232 OPSLAB *slab = (OPSLAB *) mmap(0, sz * sizeof(I32 *),
233 PROT_READ|PROT_WRITE,
234 MAP_ANON|MAP_PRIVATE, -1, 0);
235 DEBUG_m(PerlIO_printf(Perl_debug_log, "mapped %lu at %p\n",
236 (unsigned long) sz, slab));
237 if (slab == MAP_FAILED) {
238 perror("mmap failed");
239 abort();
240 }
241 slab->opslab_size = (U16)sz;
7aef8e5b 242#else
8be227ab 243 OPSLAB *slab = (OPSLAB *)PerlMemShared_calloc(sz, sizeof(I32 *));
7aef8e5b 244#endif
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245#ifndef WIN32
246 /* The context is unused in non-Windows */
247 PERL_UNUSED_CONTEXT;
248#endif
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FC
249 slab->opslab_first = (OPSLOT *)((I32 **)slab + sz - 1);
250 return slab;
251}
252
e7372881
FC
253/* requires double parens and aTHX_ */
254#define DEBUG_S_warn(args) \
255 DEBUG_S( \
256 PerlIO_printf(Perl_debug_log, "%s", SvPVx_nolen(Perl_mess args)) \
257 )
258
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259void *
260Perl_Slab_Alloc(pTHX_ size_t sz)
261{
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FC
262 OPSLAB *slab;
263 OPSLAB *slab2;
264 OPSLOT *slot;
265 OP *o;
5cb52f30 266 size_t opsz, space;
8be227ab 267
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NC
268 /* We only allocate ops from the slab during subroutine compilation.
269 We find the slab via PL_compcv, hence that must be non-NULL. It could
270 also be pointing to a subroutine which is now fully set up (CvROOT()
271 pointing to the top of the optree for that sub), or a subroutine
272 which isn't using the slab allocator. If our sanity checks aren't met,
273 don't use a slab, but allocate the OP directly from the heap. */
8be227ab
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274 if (!PL_compcv || CvROOT(PL_compcv)
275 || (CvSTART(PL_compcv) && !CvSLABBED(PL_compcv)))
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DM
276 {
277 o = (OP*)PerlMemShared_calloc(1, sz);
278 goto gotit;
279 }
8be227ab 280
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281 /* While the subroutine is under construction, the slabs are accessed via
282 CvSTART(), to avoid needing to expand PVCV by one pointer for something
283 unneeded at runtime. Once a subroutine is constructed, the slabs are
284 accessed via CvROOT(). So if CvSTART() is NULL, no slab has been
285 allocated yet. See the commit message for 8be227ab5eaa23f2 for more
286 details. */
287 if (!CvSTART(PL_compcv)) {
8be227ab
FC
288 CvSTART(PL_compcv) =
289 (OP *)(slab = S_new_slab(aTHX_ PERL_SLAB_SIZE));
290 CvSLABBED_on(PL_compcv);
291 slab->opslab_refcnt = 2; /* one for the CV; one for the new OP */
292 }
293 else ++(slab = (OPSLAB *)CvSTART(PL_compcv))->opslab_refcnt;
294
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FC
295 opsz = SIZE_TO_PSIZE(sz);
296 sz = opsz + OPSLOT_HEADER_P;
8be227ab 297
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NC
298 /* The slabs maintain a free list of OPs. In particular, constant folding
299 will free up OPs, so it makes sense to re-use them where possible. A
300 freed up slot is used in preference to a new allocation. */
8be227ab
FC
301 if (slab->opslab_freed) {
302 OP **too = &slab->opslab_freed;
303 o = *too;
eb212a1c 304 DEBUG_S_warn((aTHX_ "found free op at %p, slab %p", (void*)o, (void*)slab));
8be227ab 305 while (o && DIFF(OpSLOT(o), OpSLOT(o)->opslot_next) < sz) {
e7372881 306 DEBUG_S_warn((aTHX_ "Alas! too small"));
8be227ab 307 o = *(too = &o->op_next);
eb212a1c 308 if (o) { DEBUG_S_warn((aTHX_ "found another free op at %p", (void*)o)); }
8be227ab
FC
309 }
310 if (o) {
311 *too = o->op_next;
5cb52f30 312 Zero(o, opsz, I32 *);
8be227ab 313 o->op_slabbed = 1;
29e61fd9 314 goto gotit;
8be227ab
FC
315 }
316 }
317
7aef8e5b 318#define INIT_OPSLOT \
8be227ab
FC
319 slot->opslot_slab = slab; \
320 slot->opslot_next = slab2->opslab_first; \
321 slab2->opslab_first = slot; \
322 o = &slot->opslot_op; \
323 o->op_slabbed = 1
324
325 /* The partially-filled slab is next in the chain. */
326 slab2 = slab->opslab_next ? slab->opslab_next : slab;
327 if ((space = DIFF(&slab2->opslab_slots, slab2->opslab_first)) < sz) {
328 /* Remaining space is too small. */
329
8be227ab
FC
330 /* If we can fit a BASEOP, add it to the free chain, so as not
331 to waste it. */
332 if (space >= SIZE_TO_PSIZE(sizeof(OP)) + OPSLOT_HEADER_P) {
333 slot = &slab2->opslab_slots;
334 INIT_OPSLOT;
335 o->op_type = OP_FREED;
336 o->op_next = slab->opslab_freed;
337 slab->opslab_freed = o;
338 }
339
340 /* Create a new slab. Make this one twice as big. */
341 slot = slab2->opslab_first;
342 while (slot->opslot_next) slot = slot->opslot_next;
af7751f6
FC
343 slab2 = S_new_slab(aTHX_
344 (DIFF(slab2, slot)+1)*2 > PERL_MAX_SLAB_SIZE
e6cee8c0 345 ? PERL_MAX_SLAB_SIZE
af7751f6 346 : (DIFF(slab2, slot)+1)*2);
9963ffa2
FC
347 slab2->opslab_next = slab->opslab_next;
348 slab->opslab_next = slab2;
8be227ab
FC
349 }
350 assert(DIFF(&slab2->opslab_slots, slab2->opslab_first) >= sz);
351
352 /* Create a new op slot */
353 slot = (OPSLOT *)((I32 **)slab2->opslab_first - sz);
354 assert(slot >= &slab2->opslab_slots);
51c777ca
FC
355 if (DIFF(&slab2->opslab_slots, slot)
356 < SIZE_TO_PSIZE(sizeof(OP)) + OPSLOT_HEADER_P)
357 slot = &slab2->opslab_slots;
8be227ab 358 INIT_OPSLOT;
eb212a1c 359 DEBUG_S_warn((aTHX_ "allocating op at %p, slab %p", (void*)o, (void*)slab));
29e61fd9
DM
360
361 gotit:
93059c1a 362#ifdef PERL_OP_PARENT
87b5a8b9
DM
363 /* moresib == 0, op_sibling == 0 implies a solitary unattached op */
364 assert(!o->op_moresib);
86cd3a13 365 assert(!o->op_sibparent);
93059c1a 366#endif
29e61fd9 367
8be227ab
FC
368 return (void *)o;
369}
370
7aef8e5b 371#undef INIT_OPSLOT
8be227ab 372
7aef8e5b 373#ifdef PERL_DEBUG_READONLY_OPS
3107b51f
FC
374void
375Perl_Slab_to_ro(pTHX_ OPSLAB *slab)
376{
377 PERL_ARGS_ASSERT_SLAB_TO_RO;
378
379 if (slab->opslab_readonly) return;
380 slab->opslab_readonly = 1;
381 for (; slab; slab = slab->opslab_next) {
382 /*DEBUG_U(PerlIO_printf(Perl_debug_log,"mprotect ->ro %lu at %p\n",
383 (unsigned long) slab->opslab_size, slab));*/
384 if (mprotect(slab, slab->opslab_size * sizeof(I32 *), PROT_READ))
385 Perl_warn(aTHX_ "mprotect for %p %lu failed with %d", slab,
386 (unsigned long)slab->opslab_size, errno);
387 }
388}
389
7bbbc3c0
NC
390void
391Perl_Slab_to_rw(pTHX_ OPSLAB *const slab)
3107b51f 392{
3107b51f
FC
393 OPSLAB *slab2;
394
395 PERL_ARGS_ASSERT_SLAB_TO_RW;
396
3107b51f
FC
397 if (!slab->opslab_readonly) return;
398 slab2 = slab;
399 for (; slab2; slab2 = slab2->opslab_next) {
400 /*DEBUG_U(PerlIO_printf(Perl_debug_log,"mprotect ->rw %lu at %p\n",
401 (unsigned long) size, slab2));*/
402 if (mprotect((void *)slab2, slab2->opslab_size * sizeof(I32 *),
403 PROT_READ|PROT_WRITE)) {
404 Perl_warn(aTHX_ "mprotect RW for %p %lu failed with %d", slab,
405 (unsigned long)slab2->opslab_size, errno);
406 }
407 }
408 slab->opslab_readonly = 0;
409}
410
411#else
9e4d7a13 412# define Slab_to_rw(op) NOOP
3107b51f
FC
413#endif
414
8be227ab
FC
415/* This cannot possibly be right, but it was copied from the old slab
416 allocator, to which it was originally added, without explanation, in
417 commit 083fcd5. */
7aef8e5b 418#ifdef NETWARE
8be227ab 419# define PerlMemShared PerlMem
7aef8e5b 420#endif
8be227ab 421
c5cd8dab
DM
422/* make freed ops die if they're inadvertently executed */
423#ifdef DEBUGGING
424static OP *
425S_pp_freed(pTHX)
426{
427 DIE(aTHX_ "panic: freed op 0x%p called\n", PL_op);
428}
429#endif
430
8be227ab
FC
431void
432Perl_Slab_Free(pTHX_ void *op)
433{
434 OP * const o = (OP *)op;
435 OPSLAB *slab;
436
437 PERL_ARGS_ASSERT_SLAB_FREE;
438
c5cd8dab
DM
439#ifdef DEBUGGING
440 o->op_ppaddr = S_pp_freed;
441#endif
442
8be227ab 443 if (!o->op_slabbed) {
90840c5d
RU
444 if (!o->op_static)
445 PerlMemShared_free(op);
8be227ab
FC
446 return;
447 }
448
449 slab = OpSLAB(o);
450 /* If this op is already freed, our refcount will get screwy. */
451 assert(o->op_type != OP_FREED);
452 o->op_type = OP_FREED;
453 o->op_next = slab->opslab_freed;
454 slab->opslab_freed = o;
eb212a1c 455 DEBUG_S_warn((aTHX_ "free op at %p, recorded in slab %p", (void*)o, (void*)slab));
8be227ab
FC
456 OpslabREFCNT_dec_padok(slab);
457}
458
459void
460Perl_opslab_free_nopad(pTHX_ OPSLAB *slab)
461{
8be227ab
FC
462 const bool havepad = !!PL_comppad;
463 PERL_ARGS_ASSERT_OPSLAB_FREE_NOPAD;
464 if (havepad) {
465 ENTER;
466 PAD_SAVE_SETNULLPAD();
467 }
468 opslab_free(slab);
469 if (havepad) LEAVE;
470}
471
472void
473Perl_opslab_free(pTHX_ OPSLAB *slab)
474{
475 OPSLAB *slab2;
476 PERL_ARGS_ASSERT_OPSLAB_FREE;
81611534 477 PERL_UNUSED_CONTEXT;
eb212a1c 478 DEBUG_S_warn((aTHX_ "freeing slab %p", (void*)slab));
8be227ab 479 assert(slab->opslab_refcnt == 1);
3dc78631 480 do {
8be227ab 481 slab2 = slab->opslab_next;
7aef8e5b 482#ifdef DEBUGGING
8be227ab 483 slab->opslab_refcnt = ~(size_t)0;
7aef8e5b
FC
484#endif
485#ifdef PERL_DEBUG_READONLY_OPS
3107b51f 486 DEBUG_m(PerlIO_printf(Perl_debug_log, "Deallocate slab at %p\n",
eb212a1c 487 (void*)slab));
3107b51f
FC
488 if (munmap(slab, slab->opslab_size * sizeof(I32 *))) {
489 perror("munmap failed");
490 abort();
491 }
7aef8e5b 492#else
8be227ab 493 PerlMemShared_free(slab);
7aef8e5b 494#endif
3dc78631
DM
495 slab = slab2;
496 } while (slab);
8be227ab
FC
497}
498
499void
500Perl_opslab_force_free(pTHX_ OPSLAB *slab)
501{
502 OPSLAB *slab2;
7aef8e5b 503#ifdef DEBUGGING
8be227ab 504 size_t savestack_count = 0;
7aef8e5b 505#endif
8be227ab
FC
506 PERL_ARGS_ASSERT_OPSLAB_FORCE_FREE;
507 slab2 = slab;
508 do {
19742f39 509 OPSLOT *slot;
8be227ab
FC
510 for (slot = slab2->opslab_first;
511 slot->opslot_next;
512 slot = slot->opslot_next) {
513 if (slot->opslot_op.op_type != OP_FREED
514 && !(slot->opslot_op.op_savefree
7aef8e5b 515#ifdef DEBUGGING
8be227ab 516 && ++savestack_count
7aef8e5b 517#endif
8be227ab
FC
518 )
519 ) {
520 assert(slot->opslot_op.op_slabbed);
8be227ab 521 op_free(&slot->opslot_op);
3bf28c7e 522 if (slab->opslab_refcnt == 1) goto free;
8be227ab
FC
523 }
524 }
525 } while ((slab2 = slab2->opslab_next));
526 /* > 1 because the CV still holds a reference count. */
527 if (slab->opslab_refcnt > 1) { /* still referenced by the savestack */
7aef8e5b 528#ifdef DEBUGGING
8be227ab 529 assert(savestack_count == slab->opslab_refcnt-1);
7aef8e5b 530#endif
ee5ee853
FC
531 /* Remove the CV’s reference count. */
532 slab->opslab_refcnt--;
8be227ab
FC
533 return;
534 }
535 free:
536 opslab_free(slab);
537}
538
3107b51f
FC
539#ifdef PERL_DEBUG_READONLY_OPS
540OP *
541Perl_op_refcnt_inc(pTHX_ OP *o)
542{
543 if(o) {
372eab01
NC
544 OPSLAB *const slab = o->op_slabbed ? OpSLAB(o) : NULL;
545 if (slab && slab->opslab_readonly) {
83519873 546 Slab_to_rw(slab);
372eab01
NC
547 ++o->op_targ;
548 Slab_to_ro(slab);
549 } else {
550 ++o->op_targ;
551 }
3107b51f
FC
552 }
553 return o;
554
555}
556
557PADOFFSET
558Perl_op_refcnt_dec(pTHX_ OP *o)
559{
372eab01
NC
560 PADOFFSET result;
561 OPSLAB *const slab = o->op_slabbed ? OpSLAB(o) : NULL;
562
3107b51f 563 PERL_ARGS_ASSERT_OP_REFCNT_DEC;
372eab01
NC
564
565 if (slab && slab->opslab_readonly) {
83519873 566 Slab_to_rw(slab);
372eab01
NC
567 result = --o->op_targ;
568 Slab_to_ro(slab);
569 } else {
570 result = --o->op_targ;
571 }
572 return result;
3107b51f
FC
573}
574#endif
e50aee73 575/*
ce6f1cbc 576 * In the following definition, the ", (OP*)0" is just to make the compiler
a5f75d66 577 * think the expression is of the right type: croak actually does a Siglongjmp.
e50aee73 578 */
11343788 579#define CHECKOP(type,o) \
ce6f1cbc 580 ((PL_op_mask && PL_op_mask[type]) \
5dc0d613 581 ? ( op_free((OP*)o), \
cb77fdf0 582 Perl_croak(aTHX_ "'%s' trapped by operation mask", PL_op_desc[type]), \
ce6f1cbc 583 (OP*)0 ) \
16c91539 584 : PL_check[type](aTHX_ (OP*)o))
e50aee73 585
e6438c1a 586#define RETURN_UNLIMITED_NUMBER (PERL_INT_MAX / 2)
c53d7c7d 587
b9a07097 588#define OpTYPE_set(o,type) \
cba5a3b0
DG
589 STMT_START { \
590 o->op_type = (OPCODE)type; \
591 o->op_ppaddr = PL_ppaddr[type]; \
592 } STMT_END
593
76e3520e 594STATIC OP *
cea2e8a9 595S_no_fh_allowed(pTHX_ OP *o)
79072805 596{
7918f24d
NC
597 PERL_ARGS_ASSERT_NO_FH_ALLOWED;
598
cea2e8a9 599 yyerror(Perl_form(aTHX_ "Missing comma after first argument to %s function",
53e06cf0 600 OP_DESC(o)));
11343788 601 return o;
79072805
LW
602}
603
76e3520e 604STATIC OP *
ce16c625
BF
605S_too_few_arguments_pv(pTHX_ OP *o, const char* name, U32 flags)
606{
607 PERL_ARGS_ASSERT_TOO_FEW_ARGUMENTS_PV;
608 yyerror_pv(Perl_form(aTHX_ "Not enough arguments for %s", name), flags);
609 return o;
610}
611
612STATIC OP *
613S_too_many_arguments_pv(pTHX_ OP *o, const char *name, U32 flags)
614{
615 PERL_ARGS_ASSERT_TOO_MANY_ARGUMENTS_PV;
7918f24d 616
ce16c625 617 yyerror_pv(Perl_form(aTHX_ "Too many arguments for %s", name), flags);
11343788 618 return o;
79072805
LW
619}
620
76e3520e 621STATIC void
ed9feedd 622S_bad_type_pv(pTHX_ I32 n, const char *t, const OP *o, const OP *kid)
8990e307 623{
ce16c625
BF
624 PERL_ARGS_ASSERT_BAD_TYPE_PV;
625
626 yyerror_pv(Perl_form(aTHX_ "Type of arg %d to %s must be %s (not %s)",
ed9feedd 627 (int)n, PL_op_desc[(o)->op_type], t, OP_DESC(kid)), 0);
ce16c625 628}
7918f24d 629
ed9feedd
DD
630/* remove flags var, its unused in all callers, move to to right end since gv
631 and kid are always the same */
ce16c625 632STATIC void
ed9feedd 633S_bad_type_gv(pTHX_ I32 n, GV *gv, const OP *kid, const char *t)
ce16c625 634{
ecf05a58 635 SV * const namesv = cv_name((CV *)gv, NULL, 0);
7b3b0904 636 PERL_ARGS_ASSERT_BAD_TYPE_GV;
ce16c625 637
147e3846 638 yyerror_pv(Perl_form(aTHX_ "Type of arg %d to %" SVf " must be %s (not %s)",
ed9feedd 639 (int)n, SVfARG(namesv), t, OP_DESC(kid)), SvUTF8(namesv));
8990e307
LW
640}
641
7a52d87a 642STATIC void
eb796c7f 643S_no_bareword_allowed(pTHX_ OP *o)
7a52d87a 644{
7918f24d
NC
645 PERL_ARGS_ASSERT_NO_BAREWORD_ALLOWED;
646
5a844595 647 qerror(Perl_mess(aTHX_
147e3846 648 "Bareword \"%" SVf "\" not allowed while \"strict subs\" in use",
be2597df 649 SVfARG(cSVOPo_sv)));
eb796c7f 650 o->op_private &= ~OPpCONST_STRICT; /* prevent warning twice about the same OP */
7a52d87a
GS
651}
652
79072805
LW
653/* "register" allocation */
654
655PADOFFSET
d6447115 656Perl_allocmy(pTHX_ const char *const name, const STRLEN len, const U32 flags)
93a17b20 657{
a0d0e21e 658 PADOFFSET off;
12bd6ede 659 const bool is_our = (PL_parser->in_my == KEY_our);
a0d0e21e 660
7918f24d
NC
661 PERL_ARGS_ASSERT_ALLOCMY;
662
48d0d1be 663 if (flags & ~SVf_UTF8)
d6447115
NC
664 Perl_croak(aTHX_ "panic: allocmy illegal flag bits 0x%" UVxf,
665 (UV)flags);
666
59f00321 667 /* complain about "my $<special_var>" etc etc */
7a207065
KW
668 if ( len
669 && !( is_our
670 || isALPHA(name[1])
671 || ( (flags & SVf_UTF8)
672 && isIDFIRST_utf8_safe((U8 *)name+1, name + len))
673 || (name[1] == '_' && len > 2)))
834a4ddd 674 {
b14845b4 675 if (!(flags & SVf_UTF8 && UTF8_IS_START(name[1]))
f6a1dc93 676 && isASCII(name[1])
b14845b4 677 && (!isPRINT(name[1]) || strchr("\t\n\r\f", name[1]))) {
8d9d0498 678 /* diag_listed_as: Can't use global %s in "%s" */
d6447115
NC
679 yyerror(Perl_form(aTHX_ "Can't use global %c^%c%.*s in \"%s\"",
680 name[0], toCTRL(name[1]), (int)(len - 2), name + 2,
aab6a793 681 PL_parser->in_my == KEY_state ? "state" : "my"));
d1544d85 682 } else {
ce16c625
BF
683 yyerror_pv(Perl_form(aTHX_ "Can't use global %.*s in \"%s\"", (int) len, name,
684 PL_parser->in_my == KEY_state ? "state" : "my"), flags & SVf_UTF8);
46fc3d4c 685 }
a0d0e21e 686 }
748a9306 687
dd2155a4 688 /* allocate a spare slot and store the name in that slot */
93a17b20 689
cc76b5cc 690 off = pad_add_name_pvn(name, len,
48d0d1be 691 (is_our ? padadd_OUR :
2502ffdf 692 PL_parser->in_my == KEY_state ? padadd_STATE : 0),
12bd6ede 693 PL_parser->in_my_stash,
3edf23ff 694 (is_our
133706a6 695 /* $_ is always in main::, even with our */
ef00320b
FC
696 ? (PL_curstash && !memEQs(name,len,"$_")
697 ? PL_curstash
698 : PL_defstash)
5c284bb0 699 : NULL
cca43f78 700 )
dd2155a4 701 );
a74073ad
DM
702 /* anon sub prototypes contains state vars should always be cloned,
703 * otherwise the state var would be shared between anon subs */
704
705 if (PL_parser->in_my == KEY_state && CvANON(PL_compcv))
706 CvCLONE_on(PL_compcv);
707
dd2155a4 708 return off;
79072805
LW
709}
710
c0b8aebd 711/*
dcccc8ff
KW
712=head1 Optree Manipulation Functions
713
c0b8aebd
FC
714=for apidoc alloccopstash
715
716Available only under threaded builds, this function allocates an entry in
717C<PL_stashpad> for the stash passed to it.
718
719=cut
720*/
721
d4d03940
FC
722#ifdef USE_ITHREADS
723PADOFFSET
1dc74fdb 724Perl_alloccopstash(pTHX_ HV *hv)
d4d03940
FC
725{
726 PADOFFSET off = 0, o = 1;
727 bool found_slot = FALSE;
728
1dc74fdb
FC
729 PERL_ARGS_ASSERT_ALLOCCOPSTASH;
730
731 if (PL_stashpad[PL_stashpadix] == hv) return PL_stashpadix;
d4d03940 732
1dc74fdb
FC
733 for (; o < PL_stashpadmax; ++o) {
734 if (PL_stashpad[o] == hv) return PL_stashpadix = o;
735 if (!PL_stashpad[o] || SvTYPE(PL_stashpad[o]) != SVt_PVHV)
d4d03940
FC
736 found_slot = TRUE, off = o;
737 }
738 if (!found_slot) {
1dc74fdb
FC
739 Renew(PL_stashpad, PL_stashpadmax + 10, HV *);
740 Zero(PL_stashpad + PL_stashpadmax, 10, HV *);
741 off = PL_stashpadmax;
742 PL_stashpadmax += 10;
d4d03940
FC
743 }
744
1dc74fdb 745 PL_stashpad[PL_stashpadix = off] = hv;
d4d03940
FC
746 return off;
747}
748#endif
749
d2c837a0
DM
750/* free the body of an op without examining its contents.
751 * Always use this rather than FreeOp directly */
752
4136a0f7 753static void
d2c837a0
DM
754S_op_destroy(pTHX_ OP *o)
755{
d2c837a0
DM
756 FreeOp(o);
757}
758
79072805
LW
759/* Destructor */
760
6e53b6ca
DD
761/*
762=for apidoc Am|void|op_free|OP *o
763
cc41839b
FC
764Free an op. Only use this when an op is no longer linked to from any
765optree.
6e53b6ca
DD
766
767=cut
768*/
769
79072805 770void
864dbfa3 771Perl_op_free(pTHX_ OP *o)
79072805 772{
27da23d5 773 dVAR;
acb36ea4 774 OPCODE type;
0997db6f
TC
775 SSize_t defer_ix = -1;
776 SSize_t defer_stack_alloc = 0;
777 OP **defer_stack = NULL;
79072805 778
0997db6f 779 do {
79072805 780
0997db6f
TC
781 /* Though ops may be freed twice, freeing the op after its slab is a
782 big no-no. */
783 assert(!o || !o->op_slabbed || OpSLAB(o)->opslab_refcnt != ~(size_t)0);
784 /* During the forced freeing of ops after compilation failure, kidops
785 may be freed before their parents. */
786 if (!o || o->op_type == OP_FREED)
787 continue;
d0c8136d 788
0997db6f 789 type = o->op_type;
d0c8136d 790
0997db6f 791 /* an op should only ever acquire op_private flags that we know about.
09681a13
DM
792 * If this fails, you may need to fix something in regen/op_private.
793 * Don't bother testing if:
794 * * the op_ppaddr doesn't match the op; someone may have
795 * overridden the op and be doing strange things with it;
796 * * we've errored, as op flags are often left in an
797 * inconsistent state then. Note that an error when
798 * compiling the main program leaves PL_parser NULL, so
ad53d4d4 799 * we can't spot faults in the main code, only
09681a13
DM
800 * evaled/required code */
801#ifdef DEBUGGING
802 if ( o->op_ppaddr == PL_ppaddr[o->op_type]
803 && PL_parser
804 && !PL_parser->error_count)
805 {
0997db6f
TC
806 assert(!(o->op_private & ~PL_op_private_valid[type]));
807 }
09681a13 808#endif
7934575e 809
0997db6f
TC
810 if (o->op_private & OPpREFCOUNTED) {
811 switch (type) {
812 case OP_LEAVESUB:
813 case OP_LEAVESUBLV:
814 case OP_LEAVEEVAL:
815 case OP_LEAVE:
816 case OP_SCOPE:
817 case OP_LEAVEWRITE:
818 {
819 PADOFFSET refcnt;
820 OP_REFCNT_LOCK;
821 refcnt = OpREFCNT_dec(o);
822 OP_REFCNT_UNLOCK;
823 if (refcnt) {
824 /* Need to find and remove any pattern match ops from the list
825 we maintain for reset(). */
826 find_and_forget_pmops(o);
827 continue;
828 }
829 }
830 break;
831 default:
832 break;
833 }
834 }
f37b8c3f 835
0997db6f
TC
836 /* Call the op_free hook if it has been set. Do it now so that it's called
837 * at the right time for refcounted ops, but still before all of the kids
838 * are freed. */
839 CALL_OPFREEHOOK(o);
840
841 if (o->op_flags & OPf_KIDS) {
842 OP *kid, *nextkid;
843 for (kid = cUNOPo->op_first; kid; kid = nextkid) {
e6dae479 844 nextkid = OpSIBLING(kid); /* Get before next freeing kid */
0997db6f
TC
845 if (!kid || kid->op_type == OP_FREED)
846 /* During the forced freeing of ops after
847 compilation failure, kidops may be freed before
848 their parents. */
849 continue;
850 if (!(kid->op_flags & OPf_KIDS))
851 /* If it has no kids, just free it now */
852 op_free(kid);
853 else
aa9d1253 854 DEFER_OP(kid);
0997db6f
TC
855 }
856 }
857 if (type == OP_NULL)
858 type = (OPCODE)o->op_targ;
acb36ea4 859
0997db6f
TC
860 if (o->op_slabbed)
861 Slab_to_rw(OpSLAB(o));
fc97af9c 862
0997db6f
TC
863 /* COP* is not cleared by op_clear() so that we may track line
864 * numbers etc even after null() */
865 if (type == OP_NEXTSTATE || type == OP_DBSTATE) {
866 cop_free((COP*)o);
867 }
acb36ea4 868
0997db6f
TC
869 op_clear(o);
870 FreeOp(o);
0997db6f
TC
871 if (PL_op == o)
872 PL_op = NULL;
aa9d1253 873 } while ( (o = POP_DEFERRED_OP()) );
0997db6f
TC
874
875 Safefree(defer_stack);
acb36ea4 876}
79072805 877
ab576797
DM
878/* S_op_clear_gv(): free a GV attached to an OP */
879
f9db5646 880STATIC
ab576797
DM
881#ifdef USE_ITHREADS
882void S_op_clear_gv(pTHX_ OP *o, PADOFFSET *ixp)
883#else
884void S_op_clear_gv(pTHX_ OP *o, SV**svp)
885#endif
886{
887
fedf30e1
DM
888 GV *gv = (o->op_type == OP_GV || o->op_type == OP_GVSV
889 || o->op_type == OP_MULTIDEREF)
ab576797
DM
890#ifdef USE_ITHREADS
891 && PL_curpad
892 ? ((GV*)PAD_SVl(*ixp)) : NULL;
893#else
894 ? (GV*)(*svp) : NULL;
895#endif
896 /* It's possible during global destruction that the GV is freed
897 before the optree. Whilst the SvREFCNT_inc is happy to bump from
898 0 to 1 on a freed SV, the corresponding SvREFCNT_dec from 1 to 0
899 will trigger an assertion failure, because the entry to sv_clear
900 checks that the scalar is not already freed. A check of for
901 !SvIS_FREED(gv) turns out to be invalid, because during global
902 destruction the reference count can be forced down to zero
903 (with SVf_BREAK set). In which case raising to 1 and then
904 dropping to 0 triggers cleanup before it should happen. I
905 *think* that this might actually be a general, systematic,
906 weakness of the whole idea of SVf_BREAK, in that code *is*
907 allowed to raise and lower references during global destruction,
908 so any *valid* code that happens to do this during global
909 destruction might well trigger premature cleanup. */
910 bool still_valid = gv && SvREFCNT(gv);
911
912 if (still_valid)
913 SvREFCNT_inc_simple_void(gv);
914#ifdef USE_ITHREADS
915 if (*ixp > 0) {
916 pad_swipe(*ixp, TRUE);
917 *ixp = 0;
918 }
919#else
920 SvREFCNT_dec(*svp);
921 *svp = NULL;
922#endif
923 if (still_valid) {
924 int try_downgrade = SvREFCNT(gv) == 2;
925 SvREFCNT_dec_NN(gv);
926 if (try_downgrade)
927 gv_try_downgrade(gv);
928 }
929}
930
931
93c66552
DM
932void
933Perl_op_clear(pTHX_ OP *o)
acb36ea4 934{
13137afc 935
27da23d5 936 dVAR;
7918f24d
NC
937
938 PERL_ARGS_ASSERT_OP_CLEAR;
939
11343788 940 switch (o->op_type) {
acb36ea4 941 case OP_NULL: /* Was holding old type, if any. */
c67159e1 942 /* FALLTHROUGH */
4d193d44 943 case OP_ENTERTRY:
acb36ea4 944 case OP_ENTEREVAL: /* Was holding hints. */
4fa06845 945 case OP_ARGDEFELEM: /* Was holding signature index. */
acb36ea4 946 o->op_targ = 0;
a0d0e21e 947 break;
a6006777 948 default:
ac4c12e7 949 if (!(o->op_flags & OPf_REF)
ef69c8fc 950 || (PL_check[o->op_type] != Perl_ck_ftst))
a6006777 951 break;
924ba076 952 /* FALLTHROUGH */
463ee0b2 953 case OP_GVSV:
79072805 954 case OP_GV:
a6006777 955 case OP_AELEMFAST:
f7461760 956#ifdef USE_ITHREADS
ab576797 957 S_op_clear_gv(aTHX_ o, &(cPADOPx(o)->op_padix));
350de78d 958#else
ab576797 959 S_op_clear_gv(aTHX_ o, &(cSVOPx(o)->op_sv));
350de78d 960#endif
79072805 961 break;
810bd8b7 962 case OP_METHOD_REDIR:
963 case OP_METHOD_REDIR_SUPER:
964#ifdef USE_ITHREADS
965 if (cMETHOPx(o)->op_rclass_targ) {
966 pad_swipe(cMETHOPx(o)->op_rclass_targ, 1);
967 cMETHOPx(o)->op_rclass_targ = 0;
968 }
969#else
970 SvREFCNT_dec(cMETHOPx(o)->op_rclass_sv);
971 cMETHOPx(o)->op_rclass_sv = NULL;
972#endif
2165bd23 973 /* FALLTHROUGH */
a1ae71d2 974 case OP_METHOD_NAMED:
7d6c333c 975 case OP_METHOD_SUPER:
b46e009d 976 SvREFCNT_dec(cMETHOPx(o)->op_u.op_meth_sv);
977 cMETHOPx(o)->op_u.op_meth_sv = NULL;
978#ifdef USE_ITHREADS
979 if (o->op_targ) {
980 pad_swipe(o->op_targ, 1);
981 o->op_targ = 0;
982 }
983#endif
984 break;
79072805 985 case OP_CONST:
996c9baa 986 case OP_HINTSEVAL:
11343788 987 SvREFCNT_dec(cSVOPo->op_sv);
a0714e2c 988 cSVOPo->op_sv = NULL;
3b1c21fa
AB
989#ifdef USE_ITHREADS
990 /** Bug #15654
991 Even if op_clear does a pad_free for the target of the op,
6a077020 992 pad_free doesn't actually remove the sv that exists in the pad;
3b1c21fa
AB
993 instead it lives on. This results in that it could be reused as
994 a target later on when the pad was reallocated.
995 **/
996 if(o->op_targ) {
997 pad_swipe(o->op_targ,1);
998 o->op_targ = 0;
999 }
1000#endif
79072805 1001 break;
c9df4fda 1002 case OP_DUMP:
748a9306
LW
1003 case OP_GOTO:
1004 case OP_NEXT:
1005 case OP_LAST:
1006 case OP_REDO:
11343788 1007 if (o->op_flags & (OPf_SPECIAL|OPf_STACKED|OPf_KIDS))
748a9306 1008 break;
924ba076 1009 /* FALLTHROUGH */
a0d0e21e 1010 case OP_TRANS:
bb16bae8 1011 case OP_TRANSR:
abd07ec0
DM
1012 if ( (o->op_type == OP_TRANS || o->op_type == OP_TRANSR)
1013 && (o->op_private & (OPpTRANS_FROM_UTF|OPpTRANS_TO_UTF)))
1014 {
043e41b8
DM
1015#ifdef USE_ITHREADS
1016 if (cPADOPo->op_padix > 0) {
1017 pad_swipe(cPADOPo->op_padix, TRUE);
1018 cPADOPo->op_padix = 0;
1019 }
1020#else
a0ed51b3 1021 SvREFCNT_dec(cSVOPo->op_sv);
a0714e2c 1022 cSVOPo->op_sv = NULL;
043e41b8 1023#endif
acb36ea4
GS
1024 }
1025 else {
ea71c68d 1026 PerlMemShared_free(cPVOPo->op_pv);
bd61b366 1027 cPVOPo->op_pv = NULL;
acb36ea4 1028 }
a0d0e21e
LW
1029 break;
1030 case OP_SUBST:
20e98b0f 1031 op_free(cPMOPo->op_pmreplrootu.op_pmreplroot);
971a9dd3 1032 goto clear_pmop;
5012eebe
DM
1033
1034 case OP_SPLIT:
692044df
DM
1035 if ( (o->op_private & OPpSPLIT_ASSIGN) /* @array = split */
1036 && !(o->op_flags & OPf_STACKED)) /* @{expr} = split */
5012eebe
DM
1037 {
1038 if (o->op_private & OPpSPLIT_LEX)
1039 pad_free(cPMOPo->op_pmreplrootu.op_pmtargetoff);
1040 else
971a9dd3 1041#ifdef USE_ITHREADS
5012eebe 1042 pad_swipe(cPMOPo->op_pmreplrootu.op_pmtargetoff, TRUE);
971a9dd3 1043#else
5012eebe 1044 SvREFCNT_dec(MUTABLE_SV(cPMOPo->op_pmreplrootu.op_pmtargetgv));
971a9dd3 1045#endif
5012eebe 1046 }
924ba076 1047 /* FALLTHROUGH */
a0d0e21e 1048 case OP_MATCH:
8782bef2 1049 case OP_QR:
7b52d656 1050 clear_pmop:
867940b8
DM
1051 if (!(cPMOPo->op_pmflags & PMf_CODELIST_PRIVATE))
1052 op_free(cPMOPo->op_code_list);
68e2671b 1053 cPMOPo->op_code_list = NULL;
23083432 1054 forget_pmop(cPMOPo);
20e98b0f 1055 cPMOPo->op_pmreplrootu.op_pmreplroot = NULL;
9cddf794
NC
1056 /* we use the same protection as the "SAFE" version of the PM_ macros
1057 * here since sv_clean_all might release some PMOPs
5f8cb046
DM
1058 * after PL_regex_padav has been cleared
1059 * and the clearing of PL_regex_padav needs to
1060 * happen before sv_clean_all
1061 */
13137afc
AB
1062#ifdef USE_ITHREADS
1063 if(PL_regex_pad) { /* We could be in destruction */
402d2eb1 1064 const IV offset = (cPMOPo)->op_pmoffset;
9cddf794 1065 ReREFCNT_dec(PM_GETRE(cPMOPo));
402d2eb1
NC
1066 PL_regex_pad[offset] = &PL_sv_undef;
1067 sv_catpvn_nomg(PL_regex_pad[0], (const char *)&offset,
1068 sizeof(offset));
13137afc 1069 }
9cddf794
NC
1070#else
1071 ReREFCNT_dec(PM_GETRE(cPMOPo));
1072 PM_SETRE(cPMOPo, NULL);
1eb1540c 1073#endif
13137afc 1074
a0d0e21e 1075 break;
fedf30e1 1076
4fa06845
DM
1077 case OP_ARGCHECK:
1078 PerlMemShared_free(cUNOP_AUXo->op_aux);
1079 break;
1080
e839e6ed
DM
1081 case OP_MULTICONCAT:
1082 {
1083 UNOP_AUX_item *aux = cUNOP_AUXo->op_aux;
1084 /* aux[PERL_MULTICONCAT_IX_PLAIN_PV] and/or
1085 * aux[PERL_MULTICONCAT_IX_UTF8_PV] point to plain and/or
1086 * utf8 shared strings */
1087 char *p1 = aux[PERL_MULTICONCAT_IX_PLAIN_PV].pv;
1088 char *p2 = aux[PERL_MULTICONCAT_IX_UTF8_PV].pv;
1089 if (p1)
1090 PerlMemShared_free(p1);
1091 if (p2 && p1 != p2)
1092 PerlMemShared_free(p2);
1093 PerlMemShared_free(aux);
1094 }
1095 break;
1096
fedf30e1
DM
1097 case OP_MULTIDEREF:
1098 {
1099 UNOP_AUX_item *items = cUNOP_AUXo->op_aux;
1100 UV actions = items->uv;
1101 bool last = 0;
1102 bool is_hash = FALSE;
1103
1104 while (!last) {
1105 switch (actions & MDEREF_ACTION_MASK) {
1106
1107 case MDEREF_reload:
1108 actions = (++items)->uv;
1109 continue;
1110
1111 case MDEREF_HV_padhv_helem:
1112 is_hash = TRUE;
2165bd23 1113 /* FALLTHROUGH */
fedf30e1
DM
1114 case MDEREF_AV_padav_aelem:
1115 pad_free((++items)->pad_offset);
1116 goto do_elem;
1117
1118 case MDEREF_HV_gvhv_helem:
1119 is_hash = TRUE;
2165bd23 1120 /* FALLTHROUGH */
fedf30e1
DM
1121 case MDEREF_AV_gvav_aelem:
1122#ifdef USE_ITHREADS
1123 S_op_clear_gv(aTHX_ o, &((++items)->pad_offset));
1124#else
1125 S_op_clear_gv(aTHX_ o, &((++items)->sv));
1126#endif
1127 goto do_elem;
1128
1129 case MDEREF_HV_gvsv_vivify_rv2hv_helem:
1130 is_hash = TRUE;
2165bd23 1131 /* FALLTHROUGH */
fedf30e1
DM
1132 case MDEREF_AV_gvsv_vivify_rv2av_aelem:
1133#ifdef USE_ITHREADS
1134 S_op_clear_gv(aTHX_ o, &((++items)->pad_offset));
1135#else
1136 S_op_clear_gv(aTHX_ o, &((++items)->sv));
1137#endif
1138 goto do_vivify_rv2xv_elem;
1139
1140 case MDEREF_HV_padsv_vivify_rv2hv_helem:
1141 is_hash = TRUE;
2165bd23 1142 /* FALLTHROUGH */
fedf30e1
DM
1143 case MDEREF_AV_padsv_vivify_rv2av_aelem:
1144 pad_free((++items)->pad_offset);
1145 goto do_vivify_rv2xv_elem;
1146
1147 case MDEREF_HV_pop_rv2hv_helem:
1148 case MDEREF_HV_vivify_rv2hv_helem:
1149 is_hash = TRUE;
2165bd23 1150 /* FALLTHROUGH */
fedf30e1
DM
1151 do_vivify_rv2xv_elem:
1152 case MDEREF_AV_pop_rv2av_aelem:
1153 case MDEREF_AV_vivify_rv2av_aelem:
1154 do_elem:
1155 switch (actions & MDEREF_INDEX_MASK) {
1156 case MDEREF_INDEX_none:
1157 last = 1;
1158 break;
1159 case MDEREF_INDEX_const:
1160 if (is_hash) {
1161#ifdef USE_ITHREADS
1162 /* see RT #15654 */
1163 pad_swipe((++items)->pad_offset, 1);
1164#else
1165 SvREFCNT_dec((++items)->sv);
1166#endif
1167 }
1168 else
1169 items++;
1170 break;
1171 case MDEREF_INDEX_padsv:
1172 pad_free((++items)->pad_offset);
1173 break;
1174 case MDEREF_INDEX_gvsv:
1175#ifdef USE_ITHREADS
1176 S_op_clear_gv(aTHX_ o, &((++items)->pad_offset));
1177#else
1178 S_op_clear_gv(aTHX_ o, &((++items)->sv));
1179#endif
1180 break;
1181 }
1182
1183 if (actions & MDEREF_FLAG_last)
1184 last = 1;
1185 is_hash = FALSE;
1186
1187 break;
1188
1189 default:
1190 assert(0);
1191 last = 1;
1192 break;
1193
1194 } /* switch */
1195
1196 actions >>= MDEREF_SHIFT;
1197 } /* while */
1198
1199 /* start of malloc is at op_aux[-1], where the length is
1200 * stored */
1201 PerlMemShared_free(cUNOP_AUXo->op_aux - 1);
1202 }
1203 break;
79072805
LW
1204 }
1205
743e66e6 1206 if (o->op_targ > 0) {
11343788 1207 pad_free(o->op_targ);
743e66e6
GS
1208 o->op_targ = 0;
1209 }
79072805
LW
1210}
1211
76e3520e 1212STATIC void
3eb57f73
HS
1213S_cop_free(pTHX_ COP* cop)
1214{
7918f24d
NC
1215 PERL_ARGS_ASSERT_COP_FREE;
1216
05ec9bb3 1217 CopFILE_free(cop);
0453d815 1218 if (! specialWARN(cop->cop_warnings))
72dc9ed5 1219 PerlMemShared_free(cop->cop_warnings);
20439bc7 1220 cophh_free(CopHINTHASH_get(cop));
515abc43
FC
1221 if (PL_curcop == cop)
1222 PL_curcop = NULL;
3eb57f73
HS
1223}
1224
c2b1997a 1225STATIC void
ddda3df5 1226S_forget_pmop(pTHX_ PMOP *const o)
c2b1997a
NC
1227{
1228 HV * const pmstash = PmopSTASH(o);
7918f24d
NC
1229
1230 PERL_ARGS_ASSERT_FORGET_PMOP;
1231
e39a6381 1232 if (pmstash && !SvIS_FREED(pmstash) && SvMAGICAL(pmstash)) {
ad64d0ec 1233 MAGIC * const mg = mg_find((const SV *)pmstash, PERL_MAGIC_symtab);
c2b1997a
NC
1234 if (mg) {
1235 PMOP **const array = (PMOP**) mg->mg_ptr;
1236 U32 count = mg->mg_len / sizeof(PMOP**);
1237 U32 i = count;
1238
1239 while (i--) {
1240 if (array[i] == o) {
1241 /* Found it. Move the entry at the end to overwrite it. */
1242 array[i] = array[--count];
1243 mg->mg_len = count * sizeof(PMOP**);
1244 /* Could realloc smaller at this point always, but probably
1245 not worth it. Probably worth free()ing if we're the
1246 last. */
1247 if(!count) {
1248 Safefree(mg->mg_ptr);
1249 mg->mg_ptr = NULL;
1250 }
1251 break;
1252 }
1253 }
1254 }
1255 }
1cdf7faf
NC
1256 if (PL_curpm == o)
1257 PL_curpm = NULL;
c2b1997a
NC
1258}
1259
bfd0ff22
NC
1260STATIC void
1261S_find_and_forget_pmops(pTHX_ OP *o)
1262{
7918f24d
NC
1263 PERL_ARGS_ASSERT_FIND_AND_FORGET_PMOPS;
1264
bfd0ff22
NC
1265 if (o->op_flags & OPf_KIDS) {
1266 OP *kid = cUNOPo->op_first;
1267 while (kid) {
1268 switch (kid->op_type) {
1269 case OP_SUBST:
5012eebe 1270 case OP_SPLIT:
bfd0ff22
NC
1271 case OP_MATCH:
1272 case OP_QR:
23083432 1273 forget_pmop((PMOP*)kid);
bfd0ff22
NC
1274 }
1275 find_and_forget_pmops(kid);
e6dae479 1276 kid = OpSIBLING(kid);
bfd0ff22
NC
1277 }
1278 }
1279}
1280
6e53b6ca
DD
1281/*
1282=for apidoc Am|void|op_null|OP *o
1283
1284Neutralizes an op when it is no longer needed, but is still linked to from
1285other ops.
1286
1287=cut
1288*/
1289
93c66552
DM
1290void
1291Perl_op_null(pTHX_ OP *o)
8990e307 1292{
27da23d5 1293 dVAR;
7918f24d
NC
1294
1295 PERL_ARGS_ASSERT_OP_NULL;
1296
acb36ea4
GS
1297 if (o->op_type == OP_NULL)
1298 return;
b5bbe64a 1299 op_clear(o);
11343788 1300 o->op_targ = o->op_type;
b9a07097 1301 OpTYPE_set(o, OP_NULL);
8990e307
LW
1302}
1303
4026c95a
SH
1304void
1305Perl_op_refcnt_lock(pTHX)
e1fc825d 1306 PERL_TSA_ACQUIRE(PL_op_mutex)
4026c95a 1307{
20b7effb 1308#ifdef USE_ITHREADS
27da23d5 1309 dVAR;
20b7effb 1310#endif
96a5add6 1311 PERL_UNUSED_CONTEXT;
4026c95a
SH
1312 OP_REFCNT_LOCK;
1313}
1314
1315void
1316Perl_op_refcnt_unlock(pTHX)
e1fc825d 1317 PERL_TSA_RELEASE(PL_op_mutex)
4026c95a 1318{
20b7effb 1319#ifdef USE_ITHREADS
27da23d5 1320 dVAR;
20b7effb 1321#endif
96a5add6 1322 PERL_UNUSED_CONTEXT;
4026c95a
SH
1323 OP_REFCNT_UNLOCK;
1324}
1325
3253bf85
DM
1326
1327/*
1328=for apidoc op_sibling_splice
1329
1330A general function for editing the structure of an existing chain of
796b6530 1331op_sibling nodes. By analogy with the perl-level C<splice()> function, allows
3253bf85
DM
1332you to delete zero or more sequential nodes, replacing them with zero or
1333more different nodes. Performs the necessary op_first/op_last
29e61fd9 1334housekeeping on the parent node and op_sibling manipulation on the
7e234f81 1335children. The last deleted node will be marked as as the last node by
87b5a8b9 1336updating the op_sibling/op_sibparent or op_moresib field as appropriate.
3253bf85
DM
1337
1338Note that op_next is not manipulated, and nodes are not freed; that is the
7e234f81 1339responsibility of the caller. It also won't create a new list op for an
8ae26bff 1340empty list etc; use higher-level functions like op_append_elem() for that.
3253bf85 1341
796b6530 1342C<parent> is the parent node of the sibling chain. It may passed as C<NULL> if
3269ea41 1343the splicing doesn't affect the first or last op in the chain.
3253bf85 1344
796b6530 1345C<start> is the node preceding the first node to be spliced. Node(s)
7e234f81 1346following it will be deleted, and ops will be inserted after it. If it is
796b6530 1347C<NULL>, the first node onwards is deleted, and nodes are inserted at the
3253bf85
DM
1348beginning.
1349
796b6530 1350C<del_count> is the number of nodes to delete. If zero, no nodes are deleted.
3253bf85
DM
1351If -1 or greater than or equal to the number of remaining kids, all
1352remaining kids are deleted.
1353
796b6530
KW
1354C<insert> is the first of a chain of nodes to be inserted in place of the nodes.
1355If C<NULL>, no nodes are inserted.
3253bf85 1356
796b6530 1357The head of the chain of deleted ops is returned, or C<NULL> if no ops were
3253bf85
DM
1358deleted.
1359
1360For example:
1361
1362 action before after returns
1363 ------ ----- ----- -------
1364
1365 P P
8ae26bff
DM
1366 splice(P, A, 2, X-Y-Z) | | B-C
1367 A-B-C-D A-X-Y-Z-D
3253bf85
DM
1368
1369 P P
1370 splice(P, NULL, 1, X-Y) | | A
1371 A-B-C-D X-Y-B-C-D
1372
1373 P P
8ae26bff
DM
1374 splice(P, NULL, 3, NULL) | | A-B-C
1375 A-B-C-D D
3253bf85
DM
1376
1377 P P
1378 splice(P, B, 0, X-Y) | | NULL
1379 A-B-C-D A-B-X-Y-C-D
1380
5e24af7d
DM
1381
1382For lower-level direct manipulation of C<op_sibparent> and C<op_moresib>,
fbe13c60 1383see C<L</OpMORESIB_set>>, C<L</OpLASTSIB_set>>, C<L</OpMAYBESIB_set>>.
5e24af7d 1384
3253bf85
DM
1385=cut
1386*/
1387
1388OP *
8ae26bff 1389Perl_op_sibling_splice(OP *parent, OP *start, int del_count, OP* insert)
3253bf85 1390{
3269ea41 1391 OP *first;
3253bf85
DM
1392 OP *rest;
1393 OP *last_del = NULL;
1394 OP *last_ins = NULL;
1395
3269ea41
DM
1396 if (start)
1397 first = OpSIBLING(start);
1398 else if (!parent)
1399 goto no_parent;
1400 else
1401 first = cLISTOPx(parent)->op_first;
3253bf85
DM
1402
1403 assert(del_count >= -1);
1404
1405 if (del_count && first) {
1406 last_del = first;
e6dae479
FC
1407 while (--del_count && OpHAS_SIBLING(last_del))
1408 last_del = OpSIBLING(last_del);
1409 rest = OpSIBLING(last_del);
5e24af7d 1410 OpLASTSIB_set(last_del, NULL);
3253bf85
DM
1411 }
1412 else
1413 rest = first;
1414
1415 if (insert) {
1416 last_ins = insert;
e6dae479
FC
1417 while (OpHAS_SIBLING(last_ins))
1418 last_ins = OpSIBLING(last_ins);
5e24af7d 1419 OpMAYBESIB_set(last_ins, rest, NULL);
3253bf85
DM
1420 }
1421 else
1422 insert = rest;
1423
29e61fd9 1424 if (start) {
5e24af7d 1425 OpMAYBESIB_set(start, insert, NULL);
29e61fd9 1426 }
b3e29a8d 1427 else {
3269ea41
DM
1428 if (!parent)
1429 goto no_parent;
3253bf85 1430 cLISTOPx(parent)->op_first = insert;
b3e29a8d
DM
1431 if (insert)
1432 parent->op_flags |= OPf_KIDS;
1433 else
1434 parent->op_flags &= ~OPf_KIDS;
1435 }
3253bf85
DM
1436
1437 if (!rest) {
29e61fd9 1438 /* update op_last etc */
3269ea41 1439 U32 type;
29e61fd9 1440 OP *lastop;
3253bf85 1441
3269ea41
DM
1442 if (!parent)
1443 goto no_parent;
1444
05039abd
DM
1445 /* ought to use OP_CLASS(parent) here, but that can't handle
1446 * ex-foo OP_NULL ops. Also note that XopENTRYCUSTOM() can't
1447 * either */
3269ea41 1448 type = parent->op_type;
05039abd
DM
1449 if (type == OP_CUSTOM) {
1450 dTHX;
1451 type = XopENTRYCUSTOM(parent, xop_class);
1452 }
1453 else {
1454 if (type == OP_NULL)
1455 type = parent->op_targ;
1456 type = PL_opargs[type] & OA_CLASS_MASK;
1457 }
3253bf85 1458
29e61fd9 1459 lastop = last_ins ? last_ins : start ? start : NULL;
3253bf85
DM
1460 if ( type == OA_BINOP
1461 || type == OA_LISTOP
1462 || type == OA_PMOP
1463 || type == OA_LOOP
1464 )
29e61fd9
DM
1465 cLISTOPx(parent)->op_last = lastop;
1466
5e24af7d
DM
1467 if (lastop)
1468 OpLASTSIB_set(lastop, parent);
3253bf85
DM
1469 }
1470 return last_del ? first : NULL;
3269ea41
DM
1471
1472 no_parent:
1473 Perl_croak_nocontext("panic: op_sibling_splice(): NULL parent");
3253bf85
DM
1474}
1475
3269ea41 1476
1fafe688
DM
1477#ifdef PERL_OP_PARENT
1478
29e61fd9
DM
1479/*
1480=for apidoc op_parent
1481
796b6530 1482Returns the parent OP of C<o>, if it has a parent. Returns C<NULL> otherwise.
1fafe688 1483This function is only available on perls built with C<-DPERL_OP_PARENT>.
29e61fd9
DM
1484
1485=cut
1486*/
1487
1488OP *
8ae26bff 1489Perl_op_parent(OP *o)
29e61fd9
DM
1490{
1491 PERL_ARGS_ASSERT_OP_PARENT;
e6dae479
FC
1492 while (OpHAS_SIBLING(o))
1493 o = OpSIBLING(o);
86cd3a13 1494 return o->op_sibparent;
29e61fd9
DM
1495}
1496
1fafe688
DM
1497#endif
1498
3253bf85
DM
1499
1500/* replace the sibling following start with a new UNOP, which becomes
1501 * the parent of the original sibling; e.g.
1502 *
1503 * op_sibling_newUNOP(P, A, unop-args...)
1504 *
1505 * P P
1506 * | becomes |
1507 * A-B-C A-U-C
1508 * |
1509 * B
1510 *
1511 * where U is the new UNOP.
1512 *
1513 * parent and start args are the same as for op_sibling_splice();
1514 * type and flags args are as newUNOP().
1515 *
1516 * Returns the new UNOP.
1517 */
1518
f9db5646 1519STATIC OP *
3253bf85
DM
1520S_op_sibling_newUNOP(pTHX_ OP *parent, OP *start, I32 type, I32 flags)
1521{
1522 OP *kid, *newop;
1523
1524 kid = op_sibling_splice(parent, start, 1, NULL);
1525 newop = newUNOP(type, flags, kid);
1526 op_sibling_splice(parent, start, 0, newop);
1527 return newop;
1528}
1529
1530
1531/* lowest-level newLOGOP-style function - just allocates and populates
1532 * the struct. Higher-level stuff should be done by S_new_logop() /
1533 * newLOGOP(). This function exists mainly to avoid op_first assignment
1534 * being spread throughout this file.
1535 */
1536
6cb4123e
DM
1537LOGOP *
1538Perl_alloc_LOGOP(pTHX_ I32 type, OP *first, OP* other)
3253bf85 1539{
1e8db68a 1540 dVAR;
3253bf85 1541 LOGOP *logop;
29e61fd9 1542 OP *kid = first;
3253bf85 1543 NewOp(1101, logop, 1, LOGOP);
b9a07097 1544 OpTYPE_set(logop, type);
3253bf85
DM
1545 logop->op_first = first;
1546 logop->op_other = other;
d2d35729
FC
1547 if (first)
1548 logop->op_flags = OPf_KIDS;
e6dae479
FC
1549 while (kid && OpHAS_SIBLING(kid))
1550 kid = OpSIBLING(kid);
5e24af7d
DM
1551 if (kid)
1552 OpLASTSIB_set(kid, (OP*)logop);
3253bf85
DM
1553 return logop;
1554}
1555
1556
79072805
LW
1557/* Contextualizers */
1558
d9088386
Z
1559/*
1560=for apidoc Am|OP *|op_contextualize|OP *o|I32 context
1561
1562Applies a syntactic context to an op tree representing an expression.
2d7f6611 1563C<o> is the op tree, and C<context> must be C<G_SCALAR>, C<G_ARRAY>,
d9088386
Z
1564or C<G_VOID> to specify the context to apply. The modified op tree
1565is returned.
1566
1567=cut
1568*/
1569
1570OP *
1571Perl_op_contextualize(pTHX_ OP *o, I32 context)
1572{
1573 PERL_ARGS_ASSERT_OP_CONTEXTUALIZE;
1574 switch (context) {
1575 case G_SCALAR: return scalar(o);
1576 case G_ARRAY: return list(o);
1577 case G_VOID: return scalarvoid(o);
1578 default:
5637ef5b
NC
1579 Perl_croak(aTHX_ "panic: op_contextualize bad context %ld",
1580 (long) context);
d9088386
Z
1581 }
1582}
1583
5983a79d 1584/*
79072805 1585
5983a79d 1586=for apidoc Am|OP*|op_linklist|OP *o
72d33970 1587This function is the implementation of the L</LINKLIST> macro. It should
5983a79d
BM
1588not be called directly.
1589
1590=cut
1591*/
1592
1593OP *
1594Perl_op_linklist(pTHX_ OP *o)
79072805 1595{
3edf23ff 1596 OP *first;
79072805 1597
5983a79d 1598 PERL_ARGS_ASSERT_OP_LINKLIST;
7918f24d 1599
11343788
MB
1600 if (o->op_next)
1601 return o->op_next;
79072805
LW
1602
1603 /* establish postfix order */
3edf23ff
AL
1604 first = cUNOPo->op_first;
1605 if (first) {
eb578fdb 1606 OP *kid;
3edf23ff
AL
1607 o->op_next = LINKLIST(first);
1608 kid = first;
1609 for (;;) {
e6dae479 1610 OP *sibl = OpSIBLING(kid);
29e61fd9
DM
1611 if (sibl) {
1612 kid->op_next = LINKLIST(sibl);
1613 kid = sibl;
3edf23ff 1614 } else {
11343788 1615 kid->op_next = o;
3edf23ff
AL
1616 break;
1617 }
79072805
LW
1618 }
1619 }
1620 else
11343788 1621 o->op_next = o;
79072805 1622
11343788 1623 return o->op_next;
79072805
LW
1624}
1625
1f676739 1626static OP *
2dd5337b 1627S_scalarkids(pTHX_ OP *o)
79072805 1628{
11343788 1629 if (o && o->op_flags & OPf_KIDS) {
bfed75c6 1630 OP *kid;
e6dae479 1631 for (kid = cLISTOPo->op_first; kid; kid = OpSIBLING(kid))
79072805
LW
1632 scalar(kid);
1633 }
11343788 1634 return o;
79072805
LW
1635}
1636
76e3520e 1637STATIC OP *
cea2e8a9 1638S_scalarboolean(pTHX_ OP *o)
8990e307 1639{
7918f24d
NC
1640 PERL_ARGS_ASSERT_SCALARBOOLEAN;
1641
0a44e30b
DC
1642 if ((o->op_type == OP_SASSIGN && cBINOPo->op_first->op_type == OP_CONST &&
1643 !(cBINOPo->op_first->op_flags & OPf_SPECIAL)) ||
1644 (o->op_type == OP_NOT && cUNOPo->op_first->op_type == OP_SASSIGN &&
1645 cBINOPx(cUNOPo->op_first)->op_first->op_type == OP_CONST &&
1646 !(cBINOPx(cUNOPo->op_first)->op_first->op_flags & OPf_SPECIAL))) {
d008e5eb 1647 if (ckWARN(WARN_SYNTAX)) {
6867be6d 1648 const line_t oldline = CopLINE(PL_curcop);
a0d0e21e 1649
2b7cddde
NC
1650 if (PL_parser && PL_parser->copline != NOLINE) {
1651 /* This ensures that warnings are reported at the first line
1652 of the conditional, not the last. */
53a7735b 1653 CopLINE_set(PL_curcop, PL_parser->copline);
2b7cddde 1654 }
9014280d 1655 Perl_warner(aTHX_ packWARN(WARN_SYNTAX), "Found = in conditional, should be ==");
57843af0 1656 CopLINE_set(PL_curcop, oldline);
d008e5eb 1657 }
a0d0e21e 1658 }
11343788 1659 return scalar(o);
8990e307
LW
1660}
1661
0920b7fa 1662static SV *
637494ac 1663S_op_varname_subscript(pTHX_ const OP *o, int subscript_type)
0920b7fa
FC
1664{
1665 assert(o);
1666 assert(o->op_type == OP_PADAV || o->op_type == OP_RV2AV ||
1667 o->op_type == OP_PADHV || o->op_type == OP_RV2HV);
1668 {
1669 const char funny = o->op_type == OP_PADAV
1670 || o->op_type == OP_RV2AV ? '@' : '%';
1671 if (o->op_type == OP_RV2AV || o->op_type == OP_RV2HV) {
1672 GV *gv;
1673 if (cUNOPo->op_first->op_type != OP_GV
1674 || !(gv = cGVOPx_gv(cUNOPo->op_first)))
1675 return NULL;
637494ac 1676 return varname(gv, funny, 0, NULL, 0, subscript_type);
0920b7fa
FC
1677 }
1678 return
637494ac 1679 varname(MUTABLE_GV(PL_compcv), funny, o->op_targ, NULL, 0, subscript_type);
0920b7fa
FC
1680 }
1681}
1682
637494ac
TC
1683static SV *
1684S_op_varname(pTHX_ const OP *o)
1685{
1686 return S_op_varname_subscript(aTHX_ o, 1);
1687}
1688
429a2555 1689static void
2186f873
FC
1690S_op_pretty(pTHX_ const OP *o, SV **retsv, const char **retpv)
1691{ /* or not so pretty :-) */
2186f873
FC
1692 if (o->op_type == OP_CONST) {
1693 *retsv = cSVOPo_sv;
1694 if (SvPOK(*retsv)) {
1695 SV *sv = *retsv;
1696 *retsv = sv_newmortal();
1697 pv_pretty(*retsv, SvPVX_const(sv), SvCUR(sv), 32, NULL, NULL,
1698 PERL_PV_PRETTY_DUMP |PERL_PV_ESCAPE_UNI_DETECT);
1699 }
1700 else if (!SvOK(*retsv))
1701 *retpv = "undef";
1702 }
1703 else *retpv = "...";
1704}
1705
1706static void
429a2555
FC
1707S_scalar_slice_warning(pTHX_ const OP *o)
1708{
1709 OP *kid;
fe7df09e
FC
1710 const bool h = o->op_type == OP_HSLICE
1711 || (o->op_type == OP_NULL && o->op_targ == OP_HSLICE);
429a2555 1712 const char lbrack =
fe7df09e 1713 h ? '{' : '[';
429a2555 1714 const char rbrack =
fe7df09e 1715 h ? '}' : ']';
429a2555 1716 SV *name;
32e9ec8f 1717 SV *keysv = NULL; /* just to silence compiler warnings */
429a2555
FC
1718 const char *key = NULL;
1719
1720 if (!(o->op_private & OPpSLICEWARNING))
1721 return;
1722 if (PL_parser && PL_parser->error_count)
1723 /* This warning can be nonsensical when there is a syntax error. */
1724 return;
1725
1726 kid = cLISTOPo->op_first;
e6dae479 1727 kid = OpSIBLING(kid); /* get past pushmark */
429a2555
FC
1728 /* weed out false positives: any ops that can return lists */
1729 switch (kid->op_type) {
1730 case OP_BACKTICK:
1731 case OP_GLOB:
1732 case OP_READLINE:
1733 case OP_MATCH:
1734 case OP_RV2AV:
1735 case OP_EACH:
1736 case OP_VALUES:
1737 case OP_KEYS:
1738 case OP_SPLIT:
1739 case OP_LIST:
1740 case OP_SORT:
1741 case OP_REVERSE:
1742 case OP_ENTERSUB:
1743 case OP_CALLER:
1744 case OP_LSTAT:
1745 case OP_STAT:
1746 case OP_READDIR:
1747 case OP_SYSTEM:
1748 case OP_TMS:
1749 case OP_LOCALTIME:
1750 case OP_GMTIME:
1751 case OP_ENTEREVAL:
429a2555
FC
1752 return;
1753 }
7d3c8a68
SM
1754
1755 /* Don't warn if we have a nulled list either. */
1756 if (kid->op_type == OP_NULL && kid->op_targ == OP_LIST)
1757 return;
1758
e6dae479
FC
1759 assert(OpSIBLING(kid));
1760 name = S_op_varname(aTHX_ OpSIBLING(kid));
429a2555
FC
1761 if (!name) /* XS module fiddling with the op tree */
1762 return;
2186f873 1763 S_op_pretty(aTHX_ kid, &keysv, &key);
429a2555
FC
1764 assert(SvPOK(name));
1765 sv_chop(name,SvPVX(name)+1);
1766 if (key)
2186f873 1767 /* diag_listed_as: Scalar value @%s[%s] better written as $%s[%s] */
429a2555 1768 Perl_warner(aTHX_ packWARN(WARN_SYNTAX),
147e3846 1769 "Scalar value @%" SVf "%c%s%c better written as $%" SVf
429a2555 1770 "%c%s%c",
2186f873 1771 SVfARG(name), lbrack, key, rbrack, SVfARG(name),
429a2555
FC
1772 lbrack, key, rbrack);
1773 else
2186f873 1774 /* diag_listed_as: Scalar value @%s[%s] better written as $%s[%s] */
429a2555 1775 Perl_warner(aTHX_ packWARN(WARN_SYNTAX),
147e3846
KW
1776 "Scalar value @%" SVf "%c%" SVf "%c better written as $%"
1777 SVf "%c%" SVf "%c",
c1f6cd39
BF
1778 SVfARG(name), lbrack, SVfARG(keysv), rbrack,
1779 SVfARG(name), lbrack, SVfARG(keysv), rbrack);
429a2555
FC
1780}
1781
8990e307 1782OP *
864dbfa3 1783Perl_scalar(pTHX_ OP *o)
79072805
LW
1784{
1785 OP *kid;
1786
a0d0e21e 1787 /* assumes no premature commitment */
13765c85
DM
1788 if (!o || (PL_parser && PL_parser->error_count)
1789 || (o->op_flags & OPf_WANT)
5dc0d613 1790 || o->op_type == OP_RETURN)
7e363e51 1791 {
11343788 1792 return o;
7e363e51 1793 }
79072805 1794
5dc0d613 1795 o->op_flags = (o->op_flags & ~OPf_WANT) | OPf_WANT_SCALAR;
79072805 1796
11343788 1797 switch (o->op_type) {
79072805 1798 case OP_REPEAT:
11343788 1799 scalar(cBINOPo->op_first);
82e4f303
FC
1800 if (o->op_private & OPpREPEAT_DOLIST) {
1801 kid = cLISTOPx(cUNOPo->op_first)->op_first;
1802 assert(kid->op_type == OP_PUSHMARK);
e6dae479 1803 if (OpHAS_SIBLING(kid) && !OpHAS_SIBLING(OpSIBLING(kid))) {
82e4f303
FC
1804 op_null(cLISTOPx(cUNOPo->op_first)->op_first);
1805 o->op_private &=~ OPpREPEAT_DOLIST;
1806 }
1807 }
8990e307 1808 break;
79072805
LW
1809 case OP_OR:
1810 case OP_AND:
1811 case OP_COND_EXPR:
e6dae479 1812 for (kid = OpSIBLING(cUNOPo->op_first); kid; kid = OpSIBLING(kid))
8990e307 1813 scalar(kid);
79072805 1814 break;
924ba076 1815 /* FALLTHROUGH */
a6d8037e 1816 case OP_SPLIT:
79072805 1817 case OP_MATCH:
8782bef2 1818 case OP_QR:
79072805
LW
1819 case OP_SUBST:
1820 case OP_NULL:
8990e307 1821 default:
11343788 1822 if (o->op_flags & OPf_KIDS) {
e6dae479 1823 for (kid = cUNOPo->op_first; kid; kid = OpSIBLING(kid))
8990e307
LW
1824 scalar(kid);
1825 }
79072805
LW
1826 break;
1827 case OP_LEAVE:
1828 case OP_LEAVETRY:
5dc0d613 1829 kid = cLISTOPo->op_first;
54310121 1830 scalar(kid);
e6dae479 1831 kid = OpSIBLING(kid);
25b991bf
VP
1832 do_kids:
1833 while (kid) {
e6dae479 1834 OP *sib = OpSIBLING(kid);
7896dde7 1835 if (sib && kid->op_type != OP_LEAVEWHEN
e6dae479 1836 && ( OpHAS_SIBLING(sib) || sib->op_type != OP_NULL
34b54951
FC
1837 || ( sib->op_targ != OP_NEXTSTATE
1838 && sib->op_targ != OP_DBSTATE )))
c08f093b
VP
1839 scalarvoid(kid);
1840 else
54310121 1841 scalar(kid);
25b991bf 1842 kid = sib;
54310121 1843 }
11206fdd 1844 PL_curcop = &PL_compiling;
54310121 1845 break;
748a9306 1846 case OP_SCOPE:
79072805 1847 case OP_LINESEQ:
8990e307 1848 case OP_LIST:
25b991bf
VP
1849 kid = cLISTOPo->op_first;
1850 goto do_kids;
a801c63c 1851 case OP_SORT:
a2a5de95 1852 Perl_ck_warner(aTHX_ packWARN(WARN_VOID), "Useless use of sort in scalar context");
553e7bb0 1853 break;
95a31aad
FC
1854 case OP_KVHSLICE:
1855 case OP_KVASLICE:
2186f873
FC
1856 {
1857 /* Warn about scalar context */
1858 const char lbrack = o->op_type == OP_KVHSLICE ? '{' : '[';
1859 const char rbrack = o->op_type == OP_KVHSLICE ? '}' : ']';
1860 SV *name;
1861 SV *keysv;
1862 const char *key = NULL;
1863
1864 /* This warning can be nonsensical when there is a syntax error. */
1865 if (PL_parser && PL_parser->error_count)
1866 break;
1867
1868 if (!ckWARN(WARN_SYNTAX)) break;
1869
1870 kid = cLISTOPo->op_first;
e6dae479
FC
1871 kid = OpSIBLING(kid); /* get past pushmark */
1872 assert(OpSIBLING(kid));
1873 name = S_op_varname(aTHX_ OpSIBLING(kid));
2186f873
FC
1874 if (!name) /* XS module fiddling with the op tree */
1875 break;
1876 S_op_pretty(aTHX_ kid, &keysv, &key);
1877 assert(SvPOK(name));
1878 sv_chop(name,SvPVX(name)+1);
1879 if (key)
1880 /* diag_listed_as: %%s[%s] in scalar context better written as $%s[%s] */
1881 Perl_warner(aTHX_ packWARN(WARN_SYNTAX),
147e3846
KW
1882 "%%%" SVf "%c%s%c in scalar context better written "
1883 "as $%" SVf "%c%s%c",
2186f873
FC
1884 SVfARG(name), lbrack, key, rbrack, SVfARG(name),
1885 lbrack, key, rbrack);
1886 else
1887 /* diag_listed_as: %%s[%s] in scalar context better written as $%s[%s] */
1888 Perl_warner(aTHX_ packWARN(WARN_SYNTAX),
147e3846
KW
1889 "%%%" SVf "%c%" SVf "%c in scalar context better "
1890 "written as $%" SVf "%c%" SVf "%c",
c1f6cd39
BF
1891 SVfARG(name), lbrack, SVfARG(keysv), rbrack,
1892 SVfARG(name), lbrack, SVfARG(keysv), rbrack);
2186f873 1893 }
79072805 1894 }
11343788 1895 return o;
79072805
LW
1896}
1897
1898OP *
aa9d1253 1899Perl_scalarvoid(pTHX_ OP *arg)
79072805 1900{
27da23d5 1901 dVAR;
79072805 1902 OP *kid;
8990e307 1903 SV* sv;
aa9d1253
TC
1904 SSize_t defer_stack_alloc = 0;
1905 SSize_t defer_ix = -1;
1906 OP **defer_stack = NULL;
1907 OP *o = arg;
2ebea0a1 1908
7918f24d
NC
1909 PERL_ARGS_ASSERT_SCALARVOID;
1910
aa9d1253 1911 do {
19742f39 1912 U8 want;
aa9d1253
TC
1913 SV *useless_sv = NULL;
1914 const char* useless = NULL;
1915
26f0e7d5
TC
1916 if (o->op_type == OP_NEXTSTATE
1917 || o->op_type == OP_DBSTATE
1918 || (o->op_type == OP_NULL && (o->op_targ == OP_NEXTSTATE
1919 || o->op_targ == OP_DBSTATE)))
1920 PL_curcop = (COP*)o; /* for warning below */
1921
1922 /* assumes no premature commitment */
1923 want = o->op_flags & OPf_WANT;
1924 if ((want && want != OPf_WANT_SCALAR)
1925 || (PL_parser && PL_parser->error_count)
7896dde7 1926 || o->op_type == OP_RETURN || o->op_type == OP_REQUIRE || o->op_type == OP_LEAVEWHEN)
26f0e7d5
TC
1927 {
1928 continue;
1929 }
1c846c1f 1930
26f0e7d5
TC
1931 if ((o->op_private & OPpTARGET_MY)
1932 && (PL_opargs[o->op_type] & OA_TARGLEX))/* OPp share the meaning */
1933 {
0d18dd72
FC
1934 /* newASSIGNOP has already applied scalar context, which we
1935 leave, as if this op is inside SASSIGN. */
26f0e7d5
TC
1936 continue;
1937 }
79072805 1938
26f0e7d5 1939 o->op_flags = (o->op_flags & ~OPf_WANT) | OPf_WANT_VOID;
75068674 1940
26f0e7d5
TC
1941 switch (o->op_type) {
1942 default:
1943 if (!(PL_opargs[o->op_type] & OA_FOLDCONST))
1944 break;
1945 /* FALLTHROUGH */
1946 case OP_REPEAT:
1947 if (o->op_flags & OPf_STACKED)
1948 break;
1e2dd519
FC
1949 if (o->op_type == OP_REPEAT)
1950 scalar(cBINOPo->op_first);
26f0e7d5 1951 goto func_ops;
3d033384
Z
1952 case OP_CONCAT:
1953 if ((o->op_flags & OPf_STACKED) &&
1954 !(o->op_private & OPpCONCAT_NESTED))
1955 break;
1956 goto func_ops;
26f0e7d5
TC
1957 case OP_SUBSTR:
1958 if (o->op_private == 4)
1959 break;
1960 /* FALLTHROUGH */
26f0e7d5
TC
1961 case OP_WANTARRAY:
1962 case OP_GV:
1963 case OP_SMARTMATCH:
26f0e7d5
TC
1964 case OP_AV2ARYLEN:
1965 case OP_REF:
1966 case OP_REFGEN:
1967 case OP_SREFGEN:
1968 case OP_DEFINED:
1969 case OP_HEX:
1970 case OP_OCT:
1971 case OP_LENGTH:
1972 case OP_VEC:
1973 case OP_INDEX:
1974 case OP_RINDEX:
1975 case OP_SPRINTF:
26f0e7d5 1976 case OP_KVASLICE:
26f0e7d5
TC
1977 case OP_KVHSLICE:
1978 case OP_UNPACK:
1979 case OP_PACK:
1980 case OP_JOIN:
1981 case OP_LSLICE:
1982 case OP_ANONLIST:
1983 case OP_ANONHASH:
1984 case OP_SORT:
1985 case OP_REVERSE:
1986 case OP_RANGE:
1987 case OP_FLIP:
1988 case OP_FLOP:
1989 case OP_CALLER:
1990 case OP_FILENO:
1991 case OP_EOF:
1992 case OP_TELL:
1993 case OP_GETSOCKNAME:
1994 case OP_GETPEERNAME:
1995 case OP_READLINK:
1996 case OP_TELLDIR:
1997 case OP_GETPPID:
1998 case OP_GETPGRP:
1999 case OP_GETPRIORITY:
2000 case OP_TIME:
2001 case OP_TMS:
2002 case OP_LOCALTIME:
2003 case OP_GMTIME:
2004 case OP_GHBYNAME:
2005 case OP_GHBYADDR:
2006 case OP_GHOSTENT:
2007 case OP_GNBYNAME:
2008 case OP_GNBYADDR:
2009 case OP_GNETENT:
2010 case OP_GPBYNAME:
2011 case OP_GPBYNUMBER:
2012 case OP_GPROTOENT:
2013 case OP_GSBYNAME:
2014 case OP_GSBYPORT:
2015 case OP_GSERVENT:
2016 case OP_GPWNAM:
2017 case OP_GPWUID:
2018 case OP_GGRNAM:
2019 case OP_GGRGID:
2020 case OP_GETLOGIN:
2021 case OP_PROTOTYPE:
2022 case OP_RUNCV:
2023 func_ops:
9e209402
FC
2024 useless = OP_DESC(o);
2025 break;
2026
2027 case OP_GVSV:
2028 case OP_PADSV:
2029 case OP_PADAV:
2030 case OP_PADHV:
2031 case OP_PADANY:
2032 case OP_AELEM:
2033 case OP_AELEMFAST:
2034 case OP_AELEMFAST_LEX:
2035 case OP_ASLICE:
2036 case OP_HELEM:
2037 case OP_HSLICE:
26f0e7d5 2038 if (!(o->op_private & (OPpLVAL_INTRO|OPpOUR_INTRO)))
ea5519d6 2039 /* Otherwise it's "Useless use of grep iterator" */
3c3f8cd6 2040 useless = OP_DESC(o);
ea5519d6 2041 break;
26f0e7d5
TC
2042
2043 case OP_SPLIT:
5012eebe 2044 if (!(o->op_private & OPpSPLIT_ASSIGN))
26f0e7d5
TC
2045 useless = OP_DESC(o);
2046 break;
2047
2048 case OP_NOT:
2049 kid = cUNOPo->op_first;
2050 if (kid->op_type != OP_MATCH && kid->op_type != OP_SUBST &&
2051 kid->op_type != OP_TRANS && kid->op_type != OP_TRANSR) {
2052 goto func_ops;
2053 }
2054 useless = "negative pattern binding (!~)";
2055 break;
2056
2057 case OP_SUBST:
2058 if (cPMOPo->op_pmflags & PMf_NONDESTRUCT)
2059 useless = "non-destructive substitution (s///r)";
2060 break;
2061
2062 case OP_TRANSR:
2063 useless = "non-destructive transliteration (tr///r)";
2064 break;
2065
2066 case OP_RV2GV:
2067 case OP_RV2SV:
2068 case OP_RV2AV:
2069 case OP_RV2HV:
2070 if (!(o->op_private & (OPpLVAL_INTRO|OPpOUR_INTRO)) &&
e6dae479 2071 (!OpHAS_SIBLING(o) || OpSIBLING(o)->op_type != OP_READLINE))
26f0e7d5
TC
2072 useless = "a variable";
2073 break;
2074
2075 case OP_CONST:
2076 sv = cSVOPo_sv;
2077 if (cSVOPo->op_private & OPpCONST_STRICT)
2078 no_bareword_allowed(o);
2079 else {
2080 if (ckWARN(WARN_VOID)) {
2081 NV nv;
2082 /* don't warn on optimised away booleans, eg
2083 * use constant Foo, 5; Foo || print; */
2084 if (cSVOPo->op_private & OPpCONST_SHORTCIRCUIT)
2085 useless = NULL;
2086 /* the constants 0 and 1 are permitted as they are
2087 conventionally used as dummies in constructs like
2088 1 while some_condition_with_side_effects; */
2089 else if (SvNIOK(sv) && ((nv = SvNV(sv)) == 0.0 || nv == 1.0))
2090 useless = NULL;
2091 else if (SvPOK(sv)) {
2092 SV * const dsv = newSVpvs("");
2093 useless_sv
2094 = Perl_newSVpvf(aTHX_
2095 "a constant (%s)",
2096 pv_pretty(dsv, SvPVX_const(sv),
2097 SvCUR(sv), 32, NULL, NULL,
2098 PERL_PV_PRETTY_DUMP
2099 | PERL_PV_ESCAPE_NOCLEAR
2100 | PERL_PV_ESCAPE_UNI_DETECT));
2101 SvREFCNT_dec_NN(dsv);
2102 }
2103 else if (SvOK(sv)) {
147e3846 2104 useless_sv = Perl_newSVpvf(aTHX_ "a constant (%" SVf ")", SVfARG(sv));
26f0e7d5
TC
2105 }
2106 else
2107 useless = "a constant (undef)";
2108 }
2109 }
2110 op_null(o); /* don't execute or even remember it */
2111 break;
79072805 2112
26f0e7d5 2113 case OP_POSTINC:
b9a07097 2114 OpTYPE_set(o, OP_PREINC); /* pre-increment is faster */
26f0e7d5 2115 break;
79072805 2116
26f0e7d5 2117 case OP_POSTDEC:
b9a07097 2118 OpTYPE_set(o, OP_PREDEC); /* pre-decrement is faster */
26f0e7d5 2119 break;
79072805 2120
26f0e7d5 2121 case OP_I_POSTINC:
b9a07097 2122 OpTYPE_set(o, OP_I_PREINC); /* pre-increment is faster */
26f0e7d5 2123 break;
79072805 2124
26f0e7d5 2125 case OP_I_POSTDEC:
b9a07097 2126 OpTYPE_set(o, OP_I_PREDEC); /* pre-decrement is faster */
26f0e7d5 2127 break;
679d6c4e 2128
26f0e7d5
TC
2129 case OP_SASSIGN: {
2130 OP *rv2gv;
2131 UNOP *refgen, *rv2cv;
2132 LISTOP *exlist;
679d6c4e 2133
26f0e7d5
TC
2134 if ((o->op_private & ~OPpASSIGN_BACKWARDS) != 2)
2135 break;
f2f8fd84 2136
26f0e7d5
TC
2137 rv2gv = ((BINOP *)o)->op_last;
2138 if (!rv2gv || rv2gv->op_type != OP_RV2GV)
2139 break;
f2f8fd84 2140
26f0e7d5 2141 refgen = (UNOP *)((BINOP *)o)->op_first;
f2f8fd84 2142
26f0e7d5
TC
2143 if (!refgen || (refgen->op_type != OP_REFGEN
2144 && refgen->op_type != OP_SREFGEN))
2145 break;
f2f8fd84 2146
26f0e7d5
TC
2147 exlist = (LISTOP *)refgen->op_first;
2148 if (!exlist || exlist->op_type != OP_NULL
2149 || exlist->op_targ != OP_LIST)
2150 break;
f2f8fd84 2151
26f0e7d5
TC
2152 if (exlist->op_first->op_type != OP_PUSHMARK
2153 && exlist->op_first != exlist->op_last)
2154 break;
f2f8fd84 2155
26f0e7d5 2156 rv2cv = (UNOP*)exlist->op_last;
f2f8fd84 2157
26f0e7d5
TC
2158 if (rv2cv->op_type != OP_RV2CV)
2159 break;
f2f8fd84 2160
26f0e7d5
TC
2161 assert ((rv2gv->op_private & OPpDONT_INIT_GV) == 0);
2162 assert ((o->op_private & OPpASSIGN_CV_TO_GV) == 0);
2163 assert ((rv2cv->op_private & OPpMAY_RETURN_CONSTANT) == 0);
f2f8fd84 2164
26f0e7d5
TC
2165 o->op_private |= OPpASSIGN_CV_TO_GV;
2166 rv2gv->op_private |= OPpDONT_INIT_GV;
2167 rv2cv->op_private |= OPpMAY_RETURN_CONSTANT;
f2f8fd84 2168
26f0e7d5
TC
2169 break;
2170 }
540dd770 2171
26f0e7d5
TC
2172 case OP_AASSIGN: {
2173 inplace_aassign(o);
2174 break;
2175 }
edbe35ea 2176
26f0e7d5
TC
2177 case OP_OR:
2178 case OP_AND:
2179 kid = cLOGOPo->op_first;
2180 if (kid->op_type == OP_NOT
2181 && (kid->op_flags & OPf_KIDS)) {
2182 if (o->op_type == OP_AND) {
b9a07097 2183 OpTYPE_set(o, OP_OR);
26f0e7d5 2184 } else {
b9a07097 2185 OpTYPE_set(o, OP_AND);
26f0e7d5
TC
2186 }
2187 op_null(kid);
2188 }
2189 /* FALLTHROUGH */
5aabfad6 2190
26f0e7d5
TC
2191 case OP_DOR:
2192 case OP_COND_EXPR:
2193 case OP_ENTERGIVEN:
7896dde7 2194 case OP_ENTERWHEN:
e6dae479 2195 for (kid = OpSIBLING(cUNOPo->op_first); kid; kid = OpSIBLING(kid))
26f0e7d5
TC
2196 if (!(kid->op_flags & OPf_KIDS))
2197 scalarvoid(kid);
2198 else
2199 DEFER_OP(kid);
aa9d1253 2200 break;
095b19d1 2201
26f0e7d5
TC
2202 case OP_NULL:
2203 if (o->op_flags & OPf_STACKED)
2204 break;
2205 /* FALLTHROUGH */
2206 case OP_NEXTSTATE:
2207 case OP_DBSTATE:
2208 case OP_ENTERTRY:
2209 case OP_ENTER:
2210 if (!(o->op_flags & OPf_KIDS))
2211 break;
2212 /* FALLTHROUGH */
2213 case OP_SCOPE:
2214 case OP_LEAVE:
2215 case OP_LEAVETRY:
2216 case OP_LEAVELOOP:
2217 case OP_LINESEQ:
7896dde7
Z
2218 case OP_LEAVEGIVEN:
2219 case OP_LEAVEWHEN:
26f0e7d5 2220 kids:
e6dae479 2221 for (kid = cLISTOPo->op_first; kid; kid = OpSIBLING(kid))
26f0e7d5
TC
2222 if (!(kid->op_flags & OPf_KIDS))
2223 scalarvoid(kid);
2224 else
2225 DEFER_OP(kid);
2226 break;
2227 case OP_LIST:
2228 /* If the first kid after pushmark is something that the padrange
2229 optimisation would reject, then null the list and the pushmark.
2230 */
2231 if ((kid = cLISTOPo->op_first)->op_type == OP_PUSHMARK
e6dae479 2232 && ( !(kid = OpSIBLING(kid))
26f0e7d5
TC
2233 || ( kid->op_type != OP_PADSV
2234 && kid->op_type != OP_PADAV
2235 && kid->op_type != OP_PADHV)
2236 || kid->op_private & ~OPpLVAL_INTRO
e6dae479 2237 || !(kid = OpSIBLING(kid))
26f0e7d5
TC
2238 || ( kid->op_type != OP_PADSV
2239 && kid->op_type != OP_PADAV
2240 && kid->op_type != OP_PADHV)
2241 || kid->op_private & ~OPpLVAL_INTRO)
2242 ) {
2243 op_null(cUNOPo->op_first); /* NULL the pushmark */
2244 op_null(o); /* NULL the list */
2245 }
2246 goto kids;
2247 case OP_ENTEREVAL:
2248 scalarkids(o);
2249 break;
2250 case OP_SCALAR:
2251 scalar(o);
2252 break;
2253 }
2254
2255 if (useless_sv) {
2256 /* mortalise it, in case warnings are fatal. */
2257 Perl_ck_warner(aTHX_ packWARN(WARN_VOID),
147e3846 2258 "Useless use of %" SVf " in void context",
26f0e7d5
TC
2259 SVfARG(sv_2mortal(useless_sv)));
2260 }
2261 else if (useless) {
3c3f8cd6
AB
2262 Perl_ck_warner(aTHX_ packWARN(WARN_VOID),
2263 "Useless use of %s in void context",
2264 useless);
26f0e7d5 2265 }
aa9d1253
TC
2266 } while ( (o = POP_DEFERRED_OP()) );
2267
2268 Safefree(defer_stack);
2269
2270 return arg;
79072805
LW
2271}
2272
1f676739 2273static OP *
412da003 2274S_listkids(pTHX_ OP *o)
79072805 2275{
11343788 2276 if (o && o->op_flags & OPf_KIDS) {
6867be6d 2277 OP *kid;
e6dae479 2278 for (kid = cLISTOPo->op_first; kid; kid = OpSIBLING(kid))
79072805
LW
2279 list(kid);
2280 }
11343788 2281 return o;
79072805
LW
2282}
2283
2284OP *
864dbfa3 2285Perl_list(pTHX_ OP *o)
79072805
LW
2286{
2287 OP *kid;
2288
a0d0e21e 2289 /* assumes no premature commitment */
13765c85
DM
2290 if (!o || (o->op_flags & OPf_WANT)
2291 || (PL_parser && PL_parser->error_count)
5dc0d613 2292 || o->op_type == OP_RETURN)
7e363e51 2293 {
11343788 2294 return o;
7e363e51 2295 }
79072805 2296
b162f9ea 2297 if ((o->op_private & OPpTARGET_MY)
7e363e51
GS
2298 && (PL_opargs[o->op_type] & OA_TARGLEX))/* OPp share the meaning */
2299 {
b162f9ea 2300 return o; /* As if inside SASSIGN */
7e363e51 2301 }
1c846c1f 2302
5dc0d613 2303 o->op_flags = (o->op_flags & ~OPf_WANT) | OPf_WANT_LIST;
79072805 2304
11343788 2305 switch (o->op_type) {
79072805 2306 case OP_FLOP:
11343788 2307 list(cBINOPo->op_first);
79072805 2308 break;
c57eecc5
FC
2309 case OP_REPEAT:
2310 if (o->op_private & OPpREPEAT_DOLIST
2311 && !(o->op_flags & OPf_STACKED))
2312 {
2313 list(cBINOPo->op_first);
2314 kid = cBINOPo->op_last;
2315 if (kid->op_type == OP_CONST && SvIOK(kSVOP_sv)
2316 && SvIVX(kSVOP_sv) == 1)
2317 {
2318 op_null(o); /* repeat */
2319 op_null(cUNOPx(cBINOPo->op_first)->op_first);/* pushmark */
2320 /* const (rhs): */
2321 op_free(op_sibling_splice(o, cBINOPo->op_first, 1, NULL));
2322 }
2323 }
2324 break;
79072805
LW
2325 case OP_OR:
2326 case OP_AND:
2327 case OP_COND_EXPR:
e6dae479 2328 for (kid = OpSIBLING(cUNOPo->op_first); kid; kid = OpSIBLING(kid))
79072805
LW
2329 list(kid);
2330 break;
2331 default:
2332 case OP_MATCH:
8782bef2 2333 case OP_QR:
79072805
LW
2334 case OP_SUBST:
2335 case OP_NULL:
11343788 2336 if (!(o->op_flags & OPf_KIDS))
79072805 2337 break;
11343788
MB
2338 if (!o->op_next && cUNOPo->op_first->op_type == OP_FLOP) {
2339 list(cBINOPo->op_first);
2340 return gen_constant_list(o);
79072805 2341 }
6aa68307
FC
2342 listkids(o);
2343 break;
79072805 2344 case OP_LIST:
11343788 2345 listkids(o);
6aa68307
FC
2346 if (cLISTOPo->op_first->op_type == OP_PUSHMARK) {
2347 op_null(cUNOPo->op_first); /* NULL the pushmark */
2348 op_null(o); /* NULL the list */
2349 }
79072805
LW
2350 break;
2351 case OP_LEAVE:
2352 case OP_LEAVETRY:
5dc0d613 2353 kid = cLISTOPo->op_first;
54310121 2354 list(kid);
e6dae479 2355 kid = OpSIBLING(kid);
25b991bf
VP
2356 do_kids:
2357 while (kid) {
e6dae479 2358 OP *sib = OpSIBLING(kid);
7896dde7 2359 if (sib && kid->op_type != OP_LEAVEWHEN)
c08f093b
VP
2360 scalarvoid(kid);
2361 else
54310121 2362 list(kid);
25b991bf 2363 kid = sib;
54310121 2364 }
11206fdd 2365 PL_curcop = &PL_compiling;
54310121 2366 break;
748a9306 2367 case OP_SCOPE:
79072805 2368 case OP_LINESEQ:
25b991bf
VP
2369 kid = cLISTOPo->op_first;
2370 goto do_kids;
79072805 2371 }
11343788 2372 return o;
79072805
LW
2373}
2374
1f676739 2375static OP *
2dd5337b 2376S_scalarseq(pTHX_ OP *o)
79072805 2377{
11343788 2378 if (o) {
1496a290
AL
2379 const OPCODE type = o->op_type;
2380
2381 if (type == OP_LINESEQ || type == OP_SCOPE ||
2382 type == OP_LEAVE || type == OP_LEAVETRY)
463ee0b2 2383 {
b7bea5da
FC
2384 OP *kid, *sib;
2385 for (kid = cLISTOPo->op_first; kid; kid = sib) {
e6dae479
FC
2386 if ((sib = OpSIBLING(kid))
2387 && ( OpHAS_SIBLING(sib) || sib->op_type != OP_NULL
b7bea5da
FC
2388 || ( sib->op_targ != OP_NEXTSTATE
2389 && sib->op_targ != OP_DBSTATE )))
2390 {
463ee0b2 2391 scalarvoid(kid);
ed6116ce 2392 }
463ee0b2 2393 }
3280af22 2394 PL_curcop = &PL_compiling;
79072805 2395 }
11343788 2396 o->op_flags &= ~OPf_PARENS;
3280af22 2397 if (PL_hints & HINT_BLOCK_SCOPE)
11343788 2398 o->op_flags |= OPf_PARENS;
79072805 2399 }
8990e307 2400 else
11343788
MB
2401 o = newOP(OP_STUB, 0);
2402 return o;
79072805
LW
2403}
2404
76e3520e 2405STATIC OP *
cea2e8a9 2406S_modkids(pTHX_ OP *o, I32 type)
79072805 2407{
11343788 2408 if (o && o->op_flags & OPf_KIDS) {
6867be6d 2409 OP *kid;
e6dae479 2410 for (kid = cLISTOPo->op_first; kid; kid = OpSIBLING(kid))
3ad73efd 2411 op_lvalue(kid, type);
79072805 2412 }
11343788 2413 return o;
79072805
LW
2414}
2415
12ee5d32
DM
2416
2417/* for a helem/hslice/kvslice, if its a fixed hash, croak on invalid
2418 * const fields. Also, convert CONST keys to HEK-in-SVs.
2419 * rop is the op that retrieves the hash;
2420 * key_op is the first key
2421 */
2422
f9db5646 2423STATIC void
fedf30e1 2424S_check_hash_fields_and_hekify(pTHX_ UNOP *rop, SVOP *key_op)
12ee5d32
DM
2425{
2426 PADNAME *lexname;
2427 GV **fields;
2428 bool check_fields;
2429
2430 /* find the padsv corresponding to $lex->{} or @{$lex}{} */
2431 if (rop) {
2432 if (rop->op_first->op_type == OP_PADSV)
2433 /* @$hash{qw(keys here)} */
2434 rop = (UNOP*)rop->op_first;
2435 else {
2436 /* @{$hash}{qw(keys here)} */
2437 if (rop->op_first->op_type == OP_SCOPE
2438 && cLISTOPx(rop->op_first)->op_last->op_type == OP_PADSV)
2439 {
2440 rop = (UNOP*)cLISTOPx(rop->op_first)->op_last;
2441 }
2442 else
2443 rop = NULL;
2444 }
2445 }
2446
2447 lexname = NULL; /* just to silence compiler warnings */
2448 fields = NULL; /* just to silence compiler warnings */
2449
2450 check_fields =
2451 rop
2452 && (lexname = padnamelist_fetch(PL_comppad_name, rop->op_targ),
2453 SvPAD_TYPED(lexname))
2454 && (fields = (GV**)hv_fetchs(PadnameTYPE(lexname), "FIELDS", FALSE))
2455 && isGV(*fields) && GvHV(*fields);
2456
e6dae479 2457 for (; key_op; key_op = (SVOP*)OpSIBLING(key_op)) {
12ee5d32
DM
2458 SV **svp, *sv;
2459 if (key_op->op_type != OP_CONST)
2460 continue;
2461 svp = cSVOPx_svp(key_op);
2462
e1ccd220
DIM
2463 /* make sure it's not a bareword under strict subs */
2464 if (key_op->op_private & OPpCONST_BARE &&
2465 key_op->op_private & OPpCONST_STRICT)
2466 {
2467 no_bareword_allowed((OP*)key_op);
2468 }
2469
12ee5d32
DM
2470 /* Make the CONST have a shared SV */
2471 if ( !SvIsCOW_shared_hash(sv = *svp)
2472 && SvTYPE(sv) < SVt_PVMG
2473 && SvOK(sv)
2474 && !SvROK(sv))
2475 {
2476 SSize_t keylen;
2477 const char * const key = SvPV_const(sv, *(STRLEN*)&keylen);
2478 SV *nsv = newSVpvn_share(key, SvUTF8(sv) ? -keylen : keylen, 0);
2479 SvREFCNT_dec_NN(sv);
2480 *svp = nsv;
2481 }
2482
2483 if ( check_fields
2484 && !hv_fetch_ent(GvHV(*fields), *svp, FALSE, 0))
2485 {
147e3846
KW
2486 Perl_croak(aTHX_ "No such class field \"%" SVf "\" "
2487 "in variable %" PNf " of type %" HEKf,
12ee5d32
DM
2488 SVfARG(*svp), PNfARG(lexname),
2489 HEKfARG(HvNAME_HEK(PadnameTYPE(lexname))));
2490 }
2491 }
2492}
2493
e839e6ed
DM
2494/* info returned by S_sprintf_is_multiconcatable() */
2495
2496struct sprintf_ismc_info {
ca84e88e 2497 SSize_t nargs; /* num of args to sprintf (not including the format) */
e839e6ed
DM
2498 char *start; /* start of raw format string */
2499 char *end; /* bytes after end of raw format string */
2500 STRLEN total_len; /* total length (in bytes) of format string, not
2501 including '%s' and half of '%%' */
2502 STRLEN variant; /* number of bytes by which total_len_p would grow
2503 if upgraded to utf8 */
2504 bool utf8; /* whether the format is utf8 */
2505};
2506
2507
2508/* is the OP_SPRINTF o suitable for converting into a multiconcat op?
2509 * i.e. its format argument is a const string with only '%s' and '%%'
2510 * formats, and the number of args is known, e.g.
2511 * sprintf "a=%s f=%s", $a[0], scalar(f());
2512 * but not
2513 * sprintf "i=%d a=%s f=%s", $i, @a, f();
2514 *
2515 * If successful, the sprintf_ismc_info struct pointed to by info will be
2516 * populated.
2517 */
2518
2519STATIC bool
2520S_sprintf_is_multiconcatable(pTHX_ OP *o,struct sprintf_ismc_info *info)
2521{
2522 OP *pm, *constop, *kid;
2523 SV *sv;
2524 char *s, *e, *p;
ca84e88e 2525 SSize_t nargs, nformats;
e839e6ed
DM
2526 STRLEN cur, total_len, variant;
2527 bool utf8;
2528
2529 /* if sprintf's behaviour changes, die here so that someone
2530 * can decide whether to enhance this function or skip optimising
2531 * under those new circumstances */
2532 assert(!(o->op_flags & OPf_STACKED));
2533 assert(!(PL_opargs[OP_SPRINTF] & OA_TARGLEX));
2534 assert(!(o->op_private & ~OPpARG4_MASK));
2535
2536 pm = cUNOPo->op_first;
2537 if (pm->op_type != OP_PUSHMARK) /* weird coreargs stuff */
2538 return FALSE;
2539 constop = OpSIBLING(pm);
2540 if (!constop || constop->op_type != OP_CONST)
2541 return FALSE;
2542 sv = cSVOPx_sv(constop);
2543 if (SvMAGICAL(sv) || !SvPOK(sv))
2544 return FALSE;
2545
2546 s = SvPV(sv, cur);
2547 e = s + cur;
2548
2549 /* Scan format for %% and %s and work out how many %s there are.
2550 * Abandon if other format types are found.
2551 */
2552
2553 nformats = 0;
2554 total_len = 0;
2555 variant = 0;
2556
2557 for (p = s; p < e; p++) {
2558 if (*p != '%') {
2559 total_len++;
b3baa1fe 2560 if (!UTF8_IS_INVARIANT(*p))
e839e6ed
DM
2561 variant++;
2562 continue;
2563 }
2564 p++;
2565 if (p >= e)
2566 return FALSE; /* lone % at end gives "Invalid conversion" */
2567 if (*p == '%')
2568 total_len++;
2569 else if (*p == 's')
2570 nformats++;
2571 else
2572 return FALSE;
2573 }
2574
2575 if (!nformats || nformats > PERL_MULTICONCAT_MAXARG)
2576 return FALSE;
2577
2578 utf8 = cBOOL(SvUTF8(sv));
2579 if (utf8)
2580 variant = 0;
2581
2582 /* scan args; they must all be in scalar cxt */
2583
2584 nargs = 0;
2585 kid = OpSIBLING(constop);
2586
2587 while (kid) {
2588 if ((kid->op_flags & OPf_WANT) != OPf_WANT_SCALAR)
2589 return FALSE;
2590 nargs++;
2591 kid = OpSIBLING(kid);
2592 }
2593
2594 if (nargs != nformats)
2595 return FALSE; /* e.g. sprintf("%s%s", $a); */
2596
2597
2598 info->nargs = nargs;
2599 info->start = s;
2600 info->end = e;
2601 info->total_len = total_len;
2602 info->variant = variant;
2603 info->utf8 = utf8;
2604
2605 return TRUE;
2606}
2607
2608
2609
2610/* S_maybe_multiconcat():
2611 *
2612 * given an OP_STRINGIFY, OP_SASSIGN, OP_CONCAT or OP_SPRINTF op, possibly
2613 * convert it (and its children) into an OP_MULTICONCAT. See the code
2614 * comments just before pp_multiconcat() for the full details of what
2615 * OP_MULTICONCAT supports.
2616 *
2617 * Basically we're looking for an optree with a chain of OP_CONCATS down
2618 * the LHS (or an OP_SPRINTF), with possibly an OP_SASSIGN, and/or
2619 * OP_STRINGIFY, and/or OP_CONCAT acting as '.=' at its head, e.g.
2620 *
2621 * $x = "$a$b-$c"
2622 *
2623 * looks like
2624 *
2625 * SASSIGN
2626 * |
2627 * STRINGIFY -- PADSV[$x]
2628 * |
2629 * |
2630 * ex-PUSHMARK -- CONCAT/S
2631 * |
2632 * CONCAT/S -- PADSV[$d]
2633 * |
2634 * CONCAT -- CONST["-"]
2635 * |
2636 * PADSV[$a] -- PADSV[$b]
2637 *
2638 * Note that at this stage the OP_SASSIGN may have already been optimised
2639 * away with OPpTARGET_MY set on the OP_STRINGIFY or OP_CONCAT.
2640 */
2641
2642STATIC void
2643S_maybe_multiconcat(pTHX_ OP *o)
2644{
2645 OP *lastkidop; /* the right-most of any kids unshifted onto o */
2646 OP *topop; /* the top-most op in the concat tree (often equals o,
2647 unless there are assign/stringify ops above it */
2648 OP *parentop; /* the parent op of topop (or itself if no parent) */
2649 OP *targmyop; /* the op (if any) with the OPpTARGET_MY flag */
2650 OP *targetop; /* the op corresponding to target=... or target.=... */
2651 OP *stringop; /* the OP_STRINGIFY op, if any */
2652 OP *nextop; /* used for recreating the op_next chain without consts */
2653 OP *kid; /* general-purpose op pointer */
2654 UNOP_AUX_item *aux;
2655 UNOP_AUX_item *lenp;
2656 char *const_str, *p;
2657 struct sprintf_ismc_info sprintf_info;
2658
2659 /* store info about each arg in args[];
2660 * toparg is the highest used slot; argp is a general
2661 * pointer to args[] slots */
2662 struct {
2663 void *p; /* initially points to const sv (or null for op);
2664 later, set to SvPV(constsv), with ... */
2665 STRLEN len; /* ... len set to SvPV(..., len) */
2666 } *argp, *toparg, args[PERL_MULTICONCAT_MAXARG*2 + 1];
2667
ca84e88e
DM
2668 SSize_t nargs = 0;
2669 SSize_t nconst = 0;
f08f2d03 2670 SSize_t nadjconst = 0; /* adjacent consts - may be demoted to args */
e839e6ed
DM
2671 STRLEN variant;
2672 bool utf8 = FALSE;
2673 bool kid_is_last = FALSE; /* most args will be the RHS kid of a concat op;
2674 the last-processed arg will the LHS of one,
2675 as args are processed in reverse order */
2676 U8 stacked_last = 0; /* whether the last seen concat op was STACKED */
2677 STRLEN total_len = 0; /* sum of the lengths of the const segments */
2678 U8 flags = 0; /* what will become the op_flags and ... */
2679 U8 private_flags = 0; /* ... op_private of the multiconcat op */
2680 bool is_sprintf = FALSE; /* we're optimising an sprintf */
2681 bool is_targable = FALSE; /* targetop is an OPpTARGET_MY candidate */
f08f2d03 2682 bool prev_was_const = FALSE; /* previous arg was a const */
e839e6ed
DM
2683
2684 /* -----------------------------------------------------------------
2685 * Phase 1:
2686 *
2687 * Examine the optree non-destructively to determine whether it's
2688 * suitable to be converted into an OP_MULTICONCAT. Accumulate
2689 * information about the optree in args[].
2690 */
2691
2692 argp = args;
2693 targmyop = NULL;
2694 targetop = NULL;
2695 stringop = NULL;
2696 topop = o;
2697 parentop = o;
2698
2699 assert( o->op_type == OP_SASSIGN
2700 || o->op_type == OP_CONCAT
2701 || o->op_type == OP_SPRINTF
2702 || o->op_type == OP_STRINGIFY);
2703
da431b10
JH
2704 Zero(&sprintf_info, 1, struct sprintf_ismc_info);
2705
e839e6ed
DM
2706 /* first see if, at the top of the tree, there is an assign,
2707 * append and/or stringify */
2708
2709 if (topop->op_type == OP_SASSIGN) {
2710 /* expr = ..... */
2711 if (o->op_ppaddr != PL_ppaddr[OP_SASSIGN])
2712 return;
2713 if (o->op_private & (OPpASSIGN_BACKWARDS|OPpASSIGN_CV_TO_GV))
2714 return;
2715 assert(!(o->op_private & ~OPpARG2_MASK)); /* barf on unknown flags */
2716
2717 parentop = topop;
2718 topop = cBINOPo->op_first;
2719 targetop = OpSIBLING(topop);
2720 if (!targetop) /* probably some sort of syntax error */
2721 return;
2722 }
2723 else if ( topop->op_type == OP_CONCAT
2724 && (topop->op_flags & OPf_STACKED)
62c1220c
DM
2725 && (!(topop->op_private & OPpCONCAT_NESTED))
2726 )
e839e6ed
DM
2727 {
2728 /* expr .= ..... */
2729
2730 /* OPpTARGET_MY shouldn't be able to be set here. If it is,
2731 * decide what to do about it */
2732 assert(!(o->op_private & OPpTARGET_MY));
2733
2734 /* barf on unknown flags */
2735 assert(!(o->op_private & ~(OPpARG2_MASK|OPpTARGET_MY)));
2736 private_flags |= OPpMULTICONCAT_APPEND;
2737 targetop = cBINOPo->op_first;
2738 parentop = topop;
2739 topop = OpSIBLING(targetop);
2740
2741 /* $x .= <FOO> gets optimised to rcatline instead */
2742 if (topop->op_type == OP_READLINE)
2743 return;
2744 }
2745
2746 if (targetop) {
2747 /* Can targetop (the LHS) if it's a padsv, be be optimised
2748 * away and use OPpTARGET_MY instead?
2749 */
2750 if ( (targetop->op_type == OP_PADSV)
2751 && !(targetop->op_private & OPpDEREF)
2752 && !(targetop->op_private & OPpPAD_STATE)
2753 /* we don't support 'my $x .= ...' */
2754 && ( o->op_type == OP_SASSIGN
2755 || !(targetop->op_private & OPpLVAL_INTRO))
2756 )
2757 is_targable = TRUE;
2758 }
2759
2760 if (topop->op_type == OP_STRINGIFY) {
2761 if (topop->op_ppaddr != PL_ppaddr[OP_STRINGIFY])
2762 return;
2763 stringop = topop;
2764
2765 /* barf on unknown flags */
2766 assert(!(o->op_private & ~(OPpARG4_MASK|OPpTARGET_MY)));
2767
2768 if ((topop->op_private & OPpTARGET_MY)) {
2769 if (o->op_type == OP_SASSIGN)
2770 return; /* can't have two assigns */
2771 targmyop = topop;
2772 }
2773
2774 private_flags |= OPpMULTICONCAT_STRINGIFY;
2775 parentop = topop;
2776 topop = cBINOPx(topop)->op_first;
2777 assert(OP_TYPE_IS_OR_WAS_NN(topop, OP_PUSHMARK));
2778 topop = OpSIBLING(topop);
2779 }
2780
2781 if (topop->op_type == OP_SPRINTF) {
2782 if (topop->op_ppaddr != PL_ppaddr[OP_SPRINTF])
2783 return;
2784 if (S_sprintf_is_multiconcatable(aTHX_ topop, &sprintf_info)) {
2785 nargs = sprintf_info.nargs;
2786 total_len = sprintf_info.total_len;
2787 variant = sprintf_info.variant;
2788 utf8 = sprintf_info.utf8;
2789 is_sprintf = TRUE;
2790 private_flags |= OPpMULTICONCAT_FAKE;
2791 toparg = argp;
2792 /* we have an sprintf op rather than a concat optree.
2793 * Skip most of the code below which is associated with
2794 * processing that optree. We also skip phase 2, determining
2795 * whether its cost effective to optimise, since for sprintf,
2796 * multiconcat is *always* faster */
2797 goto create_aux;
2798 }
2799 /* note that even if the sprintf itself isn't multiconcatable,
2800 * the expression as a whole may be, e.g. in
2801 * $x .= sprintf("%d",...)
2802 * the sprintf op will be left as-is, but the concat/S op may
2803 * be upgraded to multiconcat
2804 */
2805 }
2806 else if (topop->op_type == OP_CONCAT) {
2807 if (topop->op_ppaddr != PL_ppaddr[OP_CONCAT])
2808 return;
2809
2810 if ((topop->op_private & OPpTARGET_MY)) {
2811 if (o->op_type == OP_SASSIGN || targmyop)
2812 return; /* can't have two assigns */
2813 targmyop = topop;
2814 }
2815 }
2816
2817 /* Is it safe to convert a sassign/stringify/concat op into
2818 * a multiconcat? */
2819 assert((PL_opargs[OP_SASSIGN] & OA_CLASS_MASK) == OA_BINOP);
2820 assert((PL_opargs[OP_CONCAT] & OA_CLASS_MASK) == OA_BINOP);
2821 assert((PL_opargs[OP_STRINGIFY] & OA_CLASS_MASK) == OA_LISTOP);
2822 assert((PL_opargs[OP_SPRINTF] & OA_CLASS_MASK) == OA_LISTOP);
2823 STATIC_ASSERT_STMT( STRUCT_OFFSET(BINOP, op_last)
2824 == STRUCT_OFFSET(UNOP_AUX, op_aux));
2825 STATIC_ASSERT_STMT( STRUCT_OFFSET(LISTOP, op_last)
2826 == STRUCT_OFFSET(UNOP_AUX, op_aux));
2827
2828 /* Now scan the down the tree looking for a series of
2829 * CONCAT/OPf_STACKED ops on the LHS (with the last one not
2830 * stacked). For example this tree:
2831 *
2832 * |
2833 * CONCAT/STACKED
2834 * |
2835 * CONCAT/STACKED -- EXPR5
2836 * |
2837 * CONCAT/STACKED -- EXPR4
2838 * |
2839 * CONCAT -- EXPR3
2840 * |
2841 * EXPR1 -- EXPR2
2842 *
2843 * corresponds to an expression like
2844 *
2845 * (EXPR1 . EXPR2 . EXPR3 . EXPR4 . EXPR5)
2846 *
2847 * Record info about each EXPR in args[]: in particular, whether it is
2848 * a stringifiable OP_CONST and if so what the const sv is.
2849 *
2850 * The reason why the last concat can't be STACKED is the difference
2851 * between
2852 *
2853 * ((($a .= $a) .= $a) .= $a) .= $a
2854 *
2855 * and
2856 * $a . $a . $a . $a . $a
2857 *
2858 * The main difference between the optrees for those two constructs
2859 * is the presence of the last STACKED. As well as modifying $a,
2860 * the former sees the changed $a between each concat, so if $s is
2861 * initially 'a', the first returns 'a' x 16, while the latter returns
2862 * 'a' x 5. And pp_multiconcat can't handle that kind of thing.
2863 */
2864
2865 kid = topop;
2866
2867 for (;;) {
2868 OP *argop;
2869 SV *sv;
2870 bool last = FALSE;
2871
2872 if ( kid->op_type == OP_CONCAT
2873 && !kid_is_last
2874 ) {
2875 OP *k1, *k2;
2876 k1 = cUNOPx(kid)->op_first;
2877 k2 = OpSIBLING(k1);
2878 /* shouldn't happen except maybe after compile err? */
2879 if (!k2)
2880 return;
2881
2882 /* avoid turning (A . B . ($lex = C) ...) into (A . B . C ...) */
2883 if (kid->op_private & OPpTARGET_MY)
2884 kid_is_last = TRUE;
2885
2886 stacked_last = (kid->op_flags & OPf_STACKED);
2887 if (!stacked_last)
2888 kid_is_last = TRUE;
2889
2890 kid = k1;
2891 argop = k2;
2892 }
2893 else {
2894 argop = kid;
2895 last = TRUE;
2896 }
2897
f08f2d03 2898 if ( nargs + nadjconst > PERL_MULTICONCAT_MAXARG - 2
e839e6ed
DM
2899 || (argp - args + 1) > (PERL_MULTICONCAT_MAXARG*2 + 1) - 2)
2900 {
2901 /* At least two spare slots are needed to decompose both
2902 * concat args. If there are no slots left, continue to
2903 * examine the rest of the optree, but don't push new values
2904 * on args[]. If the optree as a whole is legal for conversion
2905 * (in particular that the last concat isn't STACKED), then
2906 * the first PERL_MULTICONCAT_MAXARG elements of the optree
2907 * can be converted into an OP_MULTICONCAT now, with the first
2908 * child of that op being the remainder of the optree -
2909 * which may itself later be converted to a multiconcat op
2910 * too.
2911 */
2912 if (last) {
2913 /* the last arg is the rest of the optree */
2914 argp++->p = NULL;
2915 nargs++;
2916 }
2917 }
2918 else if ( argop->op_type == OP_CONST
2919 && ((sv = cSVOPx_sv(argop)))
2920 /* defer stringification until runtime of 'constant'
2921 * things that might stringify variantly, e.g. the radix
2922 * point of NVs, or overloaded RVs */
2923 && (SvPOK(sv) || SvIOK(sv))
2924 && (!SvGMAGICAL(sv))
2925 ) {
2926 argp++->p = sv;
2927 utf8 |= cBOOL(SvUTF8(sv));
2928 nconst++;
f08f2d03
DM
2929 if (prev_was_const)
2930 /* this const may be demoted back to a plain arg later;
2931 * make sure we have enough arg slots left */
2932 nadjconst++;
2933 prev_was_const = !prev_was_const;
e839e6ed
DM
2934 }
2935 else {
2936 argp++->p = NULL;
2937 nargs++;
f08f2d03 2938 prev_was_const = FALSE;
e839e6ed
DM
2939 }
2940
2941 if (last)
2942 break;
2943 }
2944
2945 toparg = argp - 1;
2946
2947 if (stacked_last)
2948 return; /* we don't support ((A.=B).=C)...) */
2949
bcc30fd0
DM
2950 /* look for two adjacent consts and don't fold them together:
2951 * $o . "a" . "b"
2952 * should do
2953 * $o->concat("a")->concat("b")
2954 * rather than
2955 * $o->concat("ab")
2956 * (but $o .= "a" . "b" should still fold)
2957 */
2958 {
2959 bool seen_nonconst = FALSE;
2960 for (argp = toparg; argp >= args; argp--) {
2961 if (argp->p == NULL) {
2962 seen_nonconst = TRUE;
2963 continue;
2964 }
2965 if (!seen_nonconst)
2966 continue;
2967 if (argp[1].p) {
2968 /* both previous and current arg were constants;
2969 * leave the current OP_CONST as-is */
2970 argp->p = NULL;
2971 nconst--;
2972 nargs++;
2973 }
2974 }
2975 }
2976
e839e6ed
DM
2977 /* -----------------------------------------------------------------
2978 * Phase 2:
2979 *
2980 * At this point we have determined that the optree *can* be converted
2981 * into a multiconcat. Having gathered all the evidence, we now decide
2982 * whether it *should*.
2983 */
2984
2985
2986 /* we need at least one concat action, e.g.:
2987 *
2988 * Y . Z
2989 * X = Y . Z
2990 * X .= Y
2991 *
2992 * otherwise we could be doing something like $x = "foo", which
2993 * if treated as as a concat, would fail to COW.
2994 */
2995 if (nargs + nconst + cBOOL(private_flags & OPpMULTICONCAT_APPEND) < 2)
2996 return;
2997
2998 /* Benchmarking seems to indicate that we gain if:
2999 * * we optimise at least two actions into a single multiconcat
3000 * (e.g concat+concat, sassign+concat);
3001 * * or if we can eliminate at least 1 OP_CONST;
3002 * * or if we can eliminate a padsv via OPpTARGET_MY
3003 */
3004
3005 if (
3006 /* eliminated at least one OP_CONST */
3007 nconst >= 1
3008 /* eliminated an OP_SASSIGN */
3009 || o->op_type == OP_SASSIGN
3010 /* eliminated an OP_PADSV */
3011 || (!targmyop && is_targable)
3012 )
3013 /* definitely a net gain to optimise */
3014 goto optimise;
3015
3016 /* ... if not, what else? */
3017
3018 /* special-case '$lex1 = expr . $lex1' (where expr isn't lex1):
3019 * multiconcat is faster (due to not creating a temporary copy of
3020 * $lex1), whereas for a general $lex1 = $lex2 . $lex3, concat is
3021 * faster.
3022 */
3023 if ( nconst == 0
3024 && nargs == 2
3025 && targmyop
3026 && topop->op_type == OP_CONCAT
3027 ) {
3028 PADOFFSET t = targmyop->op_targ;
3029 OP *k1 = cBINOPx(topop)->op_first;
3030 OP *k2 = cBINOPx(topop)->op_last;
3031 if ( k2->op_type == OP_PADSV
3032 && k2->op_targ == t
3033 && ( k1->op_type != OP_PADSV
3034 || k1->op_targ != t)
3035 )
3036 goto optimise;
3037 }
3038
3039 /* need at least two concats */
3040 if (nargs + nconst + cBOOL(private_flags & OPpMULTICONCAT_APPEND) < 3)
3041 return;
3042
3043
3044
3045 /* -----------------------------------------------------------------
3046 * Phase 3:
3047 *
3048 * At this point the optree has been verified as ok to be optimised
3049 * into an OP_MULTICONCAT. Now start changing things.
3050 */
3051
3052 optimise:
3053
3054 /* stringify all const args and determine utf8ness */
3055
3056 variant = 0;
3057 for (argp = args; argp <= toparg; argp++) {
3058 SV *sv = (SV*)argp->p;
3059 if (!sv)
3060 continue; /* not a const op */
3061 if (utf8 && !SvUTF8(sv))
3062 sv_utf8_upgrade_nomg(sv);
3063 argp->p = SvPV_nomg(sv, argp->len);
3064 total_len += argp->len;
3065
3066 /* see if any strings would grow if converted to utf8 */
3067 if (!utf8) {
3068 char *p = (char*)argp->p;
3069 STRLEN len = argp->len;
3070 while (len--) {
3071 U8 c = *p++;
3072 if (!UTF8_IS_INVARIANT(c))
3073 variant++;
3074 }
3075 }
3076 }
3077
3078 /* create and populate aux struct */
3079
3080 create_aux:
3081
3082 aux = (UNOP_AUX_item*)PerlMemShared_malloc(
3083 sizeof(UNOP_AUX_item)
3084 * (
3085 PERL_MULTICONCAT_HEADER_SIZE
3086 + ((nargs + 1) * (variant ? 2 : 1))
3087 )
3088 );
6623aa6a 3089 const_str = (char *)PerlMemShared_malloc(total_len ? total_len : 1);
e839e6ed
DM
3090
3091 /* Extract all the non-const expressions from the concat tree then
3092 * dispose of the old tree, e.g. convert the tree from this:
3093 *
3094 * o => SASSIGN
3095 * |
3096 * STRINGIFY -- TARGET
3097 * |
3098 * ex-PUSHMARK -- CONCAT
3099 * |
3100 * CONCAT -- EXPR5
3101 * |
3102 * CONCAT -- EXPR4
3103 * |
3104 * CONCAT -- EXPR3
3105 * |
3106 * EXPR1 -- EXPR2
3107 *
3108 *
3109 * to:
3110 *
3111 * o => MULTICONCAT
3112 * |
3113 * ex-PUSHMARK -- EXPR1 -- EXPR2 -- EXPR3 -- EXPR4 -- EXPR5 -- TARGET
3114 *
3115 * except that if EXPRi is an OP_CONST, it's discarded.
3116 *
3117 * During the conversion process, EXPR ops are stripped from the tree
3118 * and unshifted onto o. Finally, any of o's remaining original
3119 * childen are discarded and o is converted into an OP_MULTICONCAT.
3120 *
3121 * In this middle of this, o may contain both: unshifted args on the
3122 * left, and some remaining original args on the right. lastkidop
3123 * is set to point to the right-most unshifted arg to delineate
3124 * between the two sets.
3125 */
3126
3127
3128 if (is_sprintf) {
3129 /* create a copy of the format with the %'s removed, and record
3130 * the sizes of the const string segments in the aux struct */
3131 char *q, *oldq;
3132 lenp = aux + PERL_MULTICONCAT_IX_LENGTHS;
3133
3134 p = sprintf_info.start;
3135 q = const_str;
3136 oldq = q;
3137 for (; p < sprintf_info.end; p++) {
3138 if (*p == '%') {
3139 p++;
3140 if (*p != '%') {
b5bf9f73 3141 (lenp++)->ssize = q - oldq;
e839e6ed
DM
3142 oldq = q;
3143 continue;
3144 }
3145 }
3146 *q++ = *p;
3147 }
b5bf9f73 3148 lenp->ssize = q - oldq;
e839e6ed
DM
3149 assert((STRLEN)(q - const_str) == total_len);
3150
3151 /* Attach all the args (i.e. the kids of the sprintf) to o (which
3152 * may or may not be topop) The pushmark and const ops need to be
3153 * kept in case they're an op_next entry point.
3154 */
3155 lastkidop = cLISTOPx(topop)->op_last;
3156 kid = cUNOPx(topop)->op_first; /* pushmark */
3157 op_null(kid);
3158 op_null(OpSIBLING(kid)); /* const */
3159 if (o != topop) {
3160 kid = op_sibling_splice(topop, NULL, -1, NULL); /* cut all args */
3161 op_sibling_splice(o, NULL, 0, kid); /* and attach to o */
3162 lastkidop->op_next = o;
3163 }
3164 }
3165 else {
3166 p = const_str;
3167 lenp = aux + PERL_MULTICONCAT_IX_LENGTHS;
3168
b5bf9f73 3169 lenp->ssize = -1;
e839e6ed
DM
3170
3171 /* Concatenate all const strings into const_str.
3172 * Note that args[] contains the RHS args in reverse order, so
3173 * we scan args[] from top to bottom to get constant strings
3174 * in L-R order
3175 */
3176 for (argp = toparg; argp >= args; argp--) {
3177 if (!argp->p)
3178 /* not a const op */
b5bf9f73 3179 (++lenp)->ssize = -1;
e839e6ed
DM
3180 else {
3181 STRLEN l = argp->len;
3182 Copy(argp->p, p, l, char);
3183 p += l;
b5bf9f73
DM
3184 if (lenp->ssize == -1)
3185 lenp->ssize = l;
e839e6ed 3186 else
b5bf9f73 3187 lenp->ssize += l;
e839e6ed
DM
3188 }
3189 }
3190
3191 kid = topop;
3192 nextop = o;
3193 lastkidop = NULL;
3194
3195 for (argp = args; argp <= toparg; argp++) {
3196 /* only keep non-const args, except keep the first-in-next-chain
3197 * arg no matter what it is (but nulled if OP_CONST), because it
3198 * may be the entry point to this subtree from the previous
3199 * op_next.
3200 */
3201 bool last = (argp == toparg);
3202 OP *prev;
3203
3204 /* set prev to the sibling *before* the arg to be cut out,
789a38b6 3205 * e.g. when cutting EXPR:
e839e6ed
DM
3206 *
3207 * |
789a38b6 3208 * kid= CONCAT
e839e6ed 3209 * |
789a38b6 3210 * prev= CONCAT -- EXPR
e839e6ed
DM
3211 * |
3212 */
3213 if (argp == args && kid->op_type != OP_CONCAT) {
789a38b6 3214 /* in e.g. '$x .= f(1)' there's no RHS concat tree
e839e6ed
DM
3215 * so the expression to be cut isn't kid->op_last but
3216 * kid itself */
3217 OP *o1, *o2;
3218 /* find the op before kid */
3219 o1 = NULL;
3220 o2 = cUNOPx(parentop)->op_first;
3221 while (o2 && o2 != kid) {
3222 o1 = o2;
3223 o2 = OpSIBLING(o2);
3224 }
3225 assert(o2 == kid);
3226 prev = o1;
3227 kid = parentop;
3228 }
3229 else if (kid == o && lastkidop)
3230 prev = last ? lastkidop : OpSIBLING(lastkidop);
3231 else
3232 prev = last ? NULL : cUNOPx(kid)->op_first;
3233
3234 if (!argp->p || last) {
3235 /* cut RH op */
3236 OP *aop = op_sibling_splice(kid, prev, 1, NULL);
3237 /* and unshift to front of o */
3238 op_sibling_splice(o, NULL, 0, aop);
3239 /* record the right-most op added to o: later we will
3240 * free anything to the right of it */
3241 if (!lastkidop)
3242 lastkidop = aop;
3243 aop->op_next = nextop;
3244 if (last) {
3245 if (argp->p)
3246 /* null the const at start of op_next chain */
3247 op_null(aop);
3248 }
3249 else if (prev)
3250 nextop = prev->op_next;
3251 }
3252
3253 /* the last two arguments are both attached to the same concat op */
3254 if (argp < toparg - 1)
3255 kid = prev;
3256 }
3257 }
3258
3259 /* Populate the aux struct */
3260
ca84e88e 3261 aux[PERL_MULTICONCAT_IX_NARGS].ssize = nargs;
e839e6ed 3262 aux[PERL_MULTICONCAT_IX_PLAIN_PV].pv = utf8 ? NULL : const_str;
b5bf9f73 3263 aux[PERL_MULTICONCAT_IX_PLAIN_LEN].ssize = utf8 ? 0 : total_len;
e839e6ed 3264 aux[PERL_MULTICONCAT_IX_UTF8_PV].pv = const_str;
b5bf9f73 3265 aux[PERL_MULTICONCAT_IX_UTF8_LEN].ssize = total_len;
e839e6ed
DM
3266
3267 /* if variant > 0, calculate a variant const string and lengths where
3268 * the utf8 version of the string will take 'variant' more bytes than
3269 * the plain one. */
3270
3271 if (variant) {
3272 char *p = const_str;
3273 STRLEN ulen = total_len + variant;
3274 UNOP_AUX_item *lens = aux + PERL_MULTICONCAT_IX_LENGTHS;
3275 UNOP_AUX_item *ulens = lens + (nargs + 1);
3276 char *up = (char*)PerlMemShared_malloc(ulen);
ca84e88e 3277 SSize_t n;
e839e6ed
DM
3278
3279 aux[PERL_MULTICONCAT_IX_UTF8_PV].pv = up;
b5bf9f73 3280 aux[PERL_MULTICONCAT_IX_UTF8_LEN].ssize = ulen;
e839e6ed
DM
3281
3282 for (n = 0; n < (nargs + 1); n++) {
576915da
DM
3283 SSize_t i;
3284 char * orig_up = up;
b5bf9f73 3285 for (i = (lens++)->ssize; i > 0; i--) {
e839e6ed 3286 U8 c = *p++;
576915da 3287 append_utf8_from_native_byte(c, (U8**)&up);
e839e6ed 3288 }
b5bf9f73 3289 (ulens++)->ssize = (i < 0) ? i : up - orig_up;
e839e6ed
DM
3290 }
3291 }
3292
3293 if (stringop) {
3294 /* if there was a top(ish)-level OP_STRINGIFY, we need to keep
3295 * that op's first child - an ex-PUSHMARK - because the op_next of
3296 * the previous op may point to it (i.e. it's the entry point for
3297 * the o optree)
3298 */
3299 OP *pmop =
3300 (stringop == o)
3301 ? op_sibling_splice(o, lastkidop, 1, NULL)
3302 : op_sibling_splice(stringop, NULL, 1, NULL);
3303 assert(OP_TYPE_IS_OR_WAS_NN(pmop, OP_PUSHMARK));
3304 op_sibling_splice(o, NULL, 0, pmop);
3305 if (!lastkidop)
3306 lastkidop = pmop;
3307 }
3308
3309 /* Optimise
3310 * target = A.B.C...
3311 * target .= A.B.C...
3312 */
3313
3314 if (targetop) {
3315 assert(!targmyop);
3316
3317 if (o->op_type == OP_SASSIGN) {
3318 /* Move the target subtree from being the last of o's children
3319 * to being the last of o's preserved children.
3320 * Note the difference between 'target = ...' and 'target .= ...':
3321 * for the former, target is executed last; for the latter,
3322 * first.
3323 */
3324 kid = OpSIBLING(lastkidop);
3325 op_sibling_splice(o, kid, 1, NULL); /* cut target op */
3326 op_sibling_splice(o, lastkidop, 0, targetop); /* and paste */
3327 lastkidop->op_next = kid->op_next;
3328 lastkidop = targetop;
3329 }
3330 else {
3331 /* Move the target subtree from being the first of o's
3332 * original children to being the first of *all* o's children.
3333 */
3334 if (lastkidop) {
3335 op_sibling_splice(o, lastkidop, 1, NULL); /* cut target op */
3336 op_sibling_splice(o, NULL, 0, targetop); /* and paste*/
3337 }
3338 else {
3339 /* if the RHS of .= doesn't contain a concat (e.g.
3340 * $x .= "foo"), it gets missed by the "strip ops from the
3341 * tree and add to o" loop earlier */
3342 assert(topop->op_type != OP_CONCAT);
3343 if (stringop) {
3344 /* in e.g. $x .= "$y", move the $y expression
3345 * from being a child of OP_STRINGIFY to being the
3346 * second child of the OP_CONCAT
3347 */
3348 assert(cUNOPx(stringop)->op_first == topop);
3349 op_sibling_splice(stringop, NULL, 1, NULL);
3350 op_sibling_splice(o, cUNOPo->op_first, 0, topop);
3351 }
3352 assert(topop == OpSIBLING(cBINOPo->op_first));
3353 if (toparg->p)
3354 op_null(topop);
3355 lastkidop = topop;
3356 }
3357 }
3358
3359 if (is_targable) {
3360 /* optimise
3361 * my $lex = A.B.C...
3362 * $lex = A.B.C...
3363 * $lex .= A.B.C...
3364 * The original padsv op is kept but nulled in case it's the
3365 * entry point for the optree (which it will be for
3366 * '$lex .= ... '
3367 */
3368 private_flags |= OPpTARGET_MY;
3369 private_flags |= (targetop->op_private & OPpLVAL_INTRO);
3370 o->op_targ = targetop->op_targ;
3371 targetop->op_targ = 0;
3372 op_null(targetop);
3373 }
3374 else
3375 flags |= OPf_STACKED;
3376 }
3377 else if (targmyop) {
3378 private_flags |= OPpTARGET_MY;
3379 if (o != targmyop) {
3380 o->op_targ = targmyop->op_targ;
3381 targmyop->op_targ = 0;
3382 }
3383 }
3384
3385 /* detach the emaciated husk of the sprintf/concat optree and free it */
3386 for (;;) {
3387 kid = op_sibling_splice(o, lastkidop, 1, NULL);
3388 if (!kid)
3389 break;
3390 op_free(kid);
3391 }
3392
3393 /* and convert o into a multiconcat */
3394
3395 o->op_flags = (flags|OPf_KIDS|stacked_last
3396 |(o->op_flags & (OPf_WANT|OPf_PARENS)));
3397 o->op_private = private_flags;
3398 o->op_type = OP_MULTICONCAT;
3399 o->op_ppaddr = PL_ppaddr[OP_MULTICONCAT];
3400 cUNOP_AUXo->op_aux = aux;
3401}
3402
12ee5d32 3403
01f9673f
DM
3404/* do all the final processing on an optree (e.g. running the peephole
3405 * optimiser on it), then attach it to cv (if cv is non-null)
3406 */
3407
3408static void
3409S_process_optree(pTHX_ CV *cv, OP *optree, OP* start)
3410{
3411 OP **startp;
3412
3413 /* XXX for some reason, evals, require and main optrees are
3414 * never attached to their CV; instead they just hang off
3415 * PL_main_root + PL_main_start or PL_eval_root + PL_eval_start
3416 * and get manually freed when appropriate */
3417 if (cv)
3418 startp = &CvSTART(cv);
3419 else
3420 startp = PL_in_eval? &PL_eval_start : &PL_main_start;
3421
3422 *startp = start;
3423 optree->op_private |= OPpREFCOUNTED;
3424 OpREFCNT_set(optree, 1);
d2905138 3425 optimize_optree(optree);
01f9673f
DM
3426 CALL_PEEP(*startp);
3427 finalize_optree(optree);
3428 S_prune_chain_head(startp);
3429
3430 if (cv) {
3431 /* now that optimizer has done its work, adjust pad values */
3432 pad_tidy(optree->op_type == OP_LEAVEWRITE ? padtidy_FORMAT
3433 : CvCLONE(cv) ? padtidy_SUBCLONE : padtidy_SUB);
3434 }
3435}
3436
3437
3ad73efd 3438/*
d2905138
DM
3439=for apidoc optimize_optree
3440
3441This function applies some optimisations to the optree in top-down order.
3442It is called before the peephole optimizer, which processes ops in
3443execution order. Note that finalize_optree() also does a top-down scan,
3444but is called *after* the peephole optimizer.
3445
3446=cut
3447*/
3448
3449void
3450Perl_optimize_optree(pTHX_ OP* o)
3451{
3452 PERL_ARGS_ASSERT_OPTIMIZE_OPTREE;
3453
3454 ENTER;
3455 SAVEVPTR(PL_curcop);
3456
3457 optimize_op(o);
3458
3459 LEAVE;
3460}
3461
3462
3463/* helper for optimize_optree() which optimises on op then recurses
3464 * to optimise any children.
3465 */
3466
3467STATIC void
3468S_optimize_op(pTHX_ OP* o)
3469{
3470 OP *kid;
3471
3472 PERL_ARGS_ASSERT_OPTIMIZE_OP;
3473 assert(o->op_type != OP_FREED);
3474
3475 switch (o->op_type) {
3476 case OP_NEXTSTATE:
3477 case OP_DBSTATE:
3478 PL_curcop = ((COP*)o); /* for warnings */
3479 break;
3480
3481
e839e6ed
DM
3482 case OP_CONCAT:
3483 case OP_SASSIGN:
3484 case OP_STRINGIFY:
3485 case OP_SPRINTF:
3486 S_maybe_multiconcat(aTHX_ o);
3487 break;
3488
d2905138
DM
3489 case OP_SUBST:
3490 if (cPMOPo->op_pmreplrootu.op_pmreplroot)
3491 optimize_op(cPMOPo->op_pmreplrootu.op_pmreplroot);
3492 break;
3493
3494 default:
3495 break;
3496 }
3497
3498 if (!(o->op_flags & OPf_KIDS))
3499 return;
3500
3501 for (kid = cUNOPo->op_first; kid; kid = OpSIBLING(kid))
3502 optimize_op(kid);
3503}
3504
3505
3506/*
d164302a
GG
3507=for apidoc finalize_optree
3508
72d33970
FC
3509This function finalizes the optree. Should be called directly after
3510the complete optree is built. It does some additional
796b6530 3511checking which can't be done in the normal C<ck_>xxx functions and makes
d164302a
GG
3512the tree thread-safe.
3513
3514=cut
3515*/
3516void
3517Perl_finalize_optree(pTHX_ OP* o)
3518{
3519 PERL_ARGS_ASSERT_FINALIZE_OPTREE;
3520
3521 ENTER;
3522 SAVEVPTR(PL_curcop);
3523
3524 finalize_op(o);
3525
3526 LEAVE;
3527}
3528
b46e009d 3529#ifdef USE_ITHREADS
3530/* Relocate sv to the pad for thread safety.
3531 * Despite being a "constant", the SV is written to,
3532 * for reference counts, sv_upgrade() etc. */
3533PERL_STATIC_INLINE void
3534S_op_relocate_sv(pTHX_ SV** svp, PADOFFSET* targp)
3535{
3536 PADOFFSET ix;
3537 PERL_ARGS_ASSERT_OP_RELOCATE_SV;
3538 if (!*svp) return;
3539 ix = pad_alloc(OP_CONST, SVf_READONLY);
3540 SvREFCNT_dec(PAD_SVl(ix));
3541 PAD_SETSV(ix, *svp);
3542 /* XXX I don't know how this isn't readonly already. */
3543 if (!SvIsCOW(PAD_SVl(ix))) SvREADONLY_on(PAD_SVl(ix));
3544 *svp = NULL;
3545 *targp = ix;
3546}
3547#endif
3548
3549
60dde6b2 3550STATIC void
d164302a
GG
3551S_finalize_op(pTHX_ OP* o)
3552{
3553 PERL_ARGS_ASSERT_FINALIZE_OP;
3554
68d1ee85 3555 assert(o->op_type != OP_FREED);
d164302a
GG
3556
3557 switch (o->op_type) {
3558 case OP_NEXTSTATE:
3559 case OP_DBSTATE:
3560 PL_curcop = ((COP*)o); /* for warnings */
3561 break;
3562 case OP_EXEC:
e6dae479
FC
3563 if (OpHAS_SIBLING(o)) {
3564 OP *sib = OpSIBLING(o);
1ed44841
DM
3565 if (( sib->op_type == OP_NEXTSTATE || sib->op_type == OP_DBSTATE)
3566 && ckWARN(WARN_EXEC)
e6dae479 3567 && OpHAS_SIBLING(sib))
1ed44841 3568 {
e6dae479 3569 const OPCODE type = OpSIBLING(sib)->op_type;
d164302a
GG
3570 if (type != OP_EXIT && type != OP_WARN && type != OP_DIE) {
3571 const line_t oldline = CopLINE(PL_curcop);
1ed44841 3572 CopLINE_set(PL_curcop, CopLINE((COP*)sib));
d164302a
GG
3573 Perl_warner(aTHX_ packWARN(WARN_EXEC),
3574 "Statement unlikely to be reached");
3575 Perl_warner(aTHX_ packWARN(WARN_EXEC),
3576 "\t(Maybe you meant system() when you said exec()?)\n");
3577 CopLINE_set(PL_curcop, oldline);
3578 }
d164302a 3579 }
1ed44841 3580 }
d164302a
GG
3581 break;
3582
3583 case OP_GV:
3584 if ((o->op_private & OPpEARLY_CV) && ckWARN(WARN_PROTOTYPE)) {
3585 GV * const gv = cGVOPo_gv;
3586 if (SvTYPE(gv) == SVt_PVGV && GvCV(gv) && SvPVX_const(GvCV(gv))) {
3587 /* XXX could check prototype here instead of just carping */
3588 SV * const sv = sv_newmortal();
3589 gv_efullname3(sv, gv, NULL);
3590 Perl_warner(aTHX_ packWARN(WARN_PROTOTYPE),
147e3846 3591 "%" SVf "() called too early to check prototype",
d164302a
GG
3592 SVfARG(sv));
3593 }
3594 }
3595 break;
3596
3597 case OP_CONST:
eb796c7f
GG
3598 if (cSVOPo->op_private & OPpCONST_STRICT)
3599 no_bareword_allowed(o);
d164302a 3600#ifdef USE_ITHREADS
146930d1 3601 /* FALLTHROUGH */
d164302a 3602 case OP_HINTSEVAL:
b46e009d 3603 op_relocate_sv(&cSVOPo->op_sv, &o->op_targ);
3604#endif
3605 break;
3606
3607#ifdef USE_ITHREADS
3608 /* Relocate all the METHOP's SVs to the pad for thread safety. */
d164302a 3609 case OP_METHOD_NAMED:
7d6c333c 3610 case OP_METHOD_SUPER:
810bd8b7 3611 case OP_METHOD_REDIR:
3612 case OP_METHOD_REDIR_SUPER:
b46e009d 3613 op_relocate_sv(&cMETHOPx(o)->op_u.op_meth_sv, &o->op_targ);
3614 break;
d164302a 3615#endif
d164302a
GG
3616
3617 case OP_HELEM: {
3618 UNOP *rop;
565e6f7e
FC
3619 SVOP *key_op;
3620 OP *kid;
d164302a 3621
565e6f7e 3622 if ((key_op = cSVOPx(((BINOP*)o)->op_last))->op_type != OP_CONST)
d164302a
GG
3623 break;
3624
3625 rop = (UNOP*)((BINOP*)o)->op_first;
e6307ed0 3626
565e6f7e 3627 goto check_keys;
d164302a 3628
565e6f7e 3629 case OP_HSLICE:
429a2555 3630 S_scalar_slice_warning(aTHX_ o);
c67159e1 3631 /* FALLTHROUGH */
429a2555 3632
c5f75dba 3633 case OP_KVHSLICE:
e6dae479 3634 kid = OpSIBLING(cLISTOPo->op_first);
71323522 3635 if (/* I bet there's always a pushmark... */
7d3c8a68
SM
3636 OP_TYPE_ISNT_AND_WASNT_NN(kid, OP_LIST)
3637 && OP_TYPE_ISNT_NN(kid, OP_CONST))
3638 {
d164302a 3639 break;
7d3c8a68 3640 }
565e6f7e
FC
3641
3642 key_op = (SVOP*)(kid->op_type == OP_CONST
3643 ? kid
e6dae479 3644 : OpSIBLING(kLISTOP->op_first));
565e6f7e
FC
3645
3646 rop = (UNOP*)((LISTOP*)o)->op_last;
3647
3648 check_keys:
12ee5d32
DM
3649 if (o->op_private & OPpLVAL_INTRO || rop->op_type != OP_RV2HV)
3650 rop = NULL;
fedf30e1 3651 S_check_hash_fields_and_hekify(aTHX_ rop, key_op);
d164302a
GG
3652 break;
3653 }
fe7df09e
FC
3654 case OP_NULL:
3655 if (o->op_targ != OP_HSLICE && o->op_targ != OP_ASLICE)
3656 break;
3657 /* FALLTHROUGH */
429a2555
FC
3658 case OP_ASLICE:
3659 S_scalar_slice_warning(aTHX_ o);
3660 break;
a7fd8ef6 3661
d164302a
GG
3662 case OP_SUBST: {
3663 if (cPMOPo->op_pmreplrootu.op_pmreplroot)
3664 finalize_op(cPMOPo->op_pmreplrootu.op_pmreplroot);
3665 break;
3666 }
3667 default:
3668 break;
3669 }
3670
3671 if (o->op_flags & OPf_KIDS) {
3672 OP *kid;
c4b20975
DM
3673
3674#ifdef DEBUGGING
20220689 3675 /* check that op_last points to the last sibling, and that
86cd3a13
DM
3676 * the last op_sibling/op_sibparent field points back to the
3677 * parent, and that the only ops with KIDS are those which are
3678 * entitled to them */
c4b20975
DM
3679 U32 type = o->op_type;
3680 U32 family;
20220689 3681 bool has_last;
c4b20975
DM
3682
3683 if (type == OP_NULL) {
3684 type = o->op_targ;
3685 /* ck_glob creates a null UNOP with ex-type GLOB
3686 * (which is a list op. So pretend it wasn't a listop */
3687 if (type == OP_GLOB)
3688 type = OP_NULL;
3689 }
3690 family = PL_opargs[type] & OA_CLASS_MASK;
3691
20220689
DM
3692 has_last = ( family == OA_BINOP
3693 || family == OA_LISTOP
3694 || family == OA_PMOP
3695 || family == OA_LOOP
3696 );
3697 assert( has_last /* has op_first and op_last, or ...
3698 ... has (or may have) op_first: */
3699 || family == OA_UNOP
2f7c6295 3700 || family == OA_UNOP_AUX
20220689
DM
3701 || family == OA_LOGOP
3702 || family == OA_BASEOP_OR_UNOP
3703 || family == OA_FILESTATOP
3704 || family == OA_LOOPEXOP
b46e009d 3705 || family == OA_METHOP
20220689
DM
3706 || type == OP_CUSTOM
3707 || type == OP_NULL /* new_logop does this */
3708 );
20220689 3709
e6dae479 3710 for (kid = cUNOPo->op_first; kid; kid = OpSIBLING(kid)) {
29e61fd9 3711# ifdef PERL_OP_PARENT
e6dae479 3712 if (!OpHAS_SIBLING(kid)) {
20220689 3713 if (has_last)
29e61fd9 3714 assert(kid == cLISTOPo->op_last);
86cd3a13 3715 assert(kid->op_sibparent == o);
20220689 3716 }
29e61fd9 3717# else
35a2929b 3718 if (has_last && !OpHAS_SIBLING(kid))
93059c1a 3719 assert(kid == cLISTOPo->op_last);
20220689 3720# endif
c4b20975
DM
3721 }
3722#endif
3723
e6dae479 3724 for (kid = cUNOPo->op_first; kid; kid = OpSIBLING(kid))
d164302a
GG
3725 finalize_op(kid);
3726 }
3727}
3728
3729/*
3ad73efd
Z
3730=for apidoc Amx|OP *|op_lvalue|OP *o|I32 type
3731
3732Propagate lvalue ("modifiable") context to an op and its children.
2d7f6611 3733C<type> represents the context type, roughly based on the type of op that
796b6530 3734would do the modifying, although C<local()> is represented by C<OP_NULL>,
3ad73efd 3735because it has no op type of its own (it is signalled by a flag on
001c3c51
FC
3736the lvalue op).
3737
3738This function detects things that can't be modified, such as C<$x+1>, and
72d33970 3739generates errors for them. For example, C<$x+1 = 2> would cause it to be
796b6530 3740called with an op of type C<OP_ADD> and a C<type> argument of C<OP_SASSIGN>.
001c3c51
FC
3741
3742It also flags things that need to behave specially in an lvalue context,
3743such as C<$$x = 5> which might have to vivify a reference in C<$x>.
3ad73efd
Z
3744
3745=cut
3746*/
ddeae0f1 3747
03414f05
FC
3748static void
3749S_mark_padname_lvalue(pTHX_ PADNAME *pn)
3750{
3751 CV *cv = PL_compcv;
3752 PadnameLVALUE_on(pn);
3753 while (PadnameOUTER(pn) && PARENT_PAD_INDEX(pn)) {
3754 cv = CvOUTSIDE(cv);
aea0412a
DM
3755 /* RT #127786: cv can be NULL due to an eval within the DB package
3756 * called from an anon sub - anon subs don't have CvOUTSIDE() set
3757 * unless they contain an eval, but calling eval within DB
3758 * pretends the eval was done in the caller's scope.
3759 */
3760 if (!cv)
3761 break;
03414f05
FC
3762 assert(CvPADLIST(cv));
3763 pn =
3764 PadlistNAMESARRAY(CvPADLIST(cv))[PARENT_PAD_INDEX(pn)];
3765 assert(PadnameLEN(pn));
3766 PadnameLVALUE_on(pn);
3767 }
3768}
3769
375879aa
FC
3770static bool
3771S_vivifies(const OPCODE type)
3772{
3773 switch(type) {
3774 case OP_RV2AV: case OP_ASLICE:
3775 case OP_RV2HV: case OP_KVASLICE:
3776 case OP_RV2SV: case OP_HSLICE:
3777 case OP_AELEMFAST: case OP_KVHSLICE:
3778 case OP_HELEM:
3779 case OP_AELEM:
3780 return 1;
3781 }
3782 return 0;
3783}
3784
7664512e 3785static void
63702de8 3786S_lvref(pTHX_ OP *o, I32 type)
7664512e 3787{
727d2dc6 3788 dVAR;
7664512e
FC
3789 OP *kid;
3790 switch (o->op_type) {
3791 case OP_COND_EXPR:
e6dae479
FC
3792 for (kid = OpSIBLING(cUNOPo->op_first); kid;
3793 kid = OpSIBLING(kid))
63702de8 3794 S_lvref(aTHX_ kid, type);
7664512e
FC
3795 /* FALLTHROUGH */
3796 case OP_PUSHMARK:
3797 return;
3798 case OP_RV2AV:
3799 if (cUNOPo->op_first->op_type != OP_GV) goto badref;
3800 o->op_flags |= OPf_STACKED;
3801 if (o->op_flags & OPf_PARENS) {
3802 if (o->op_private & OPpLVAL_INTRO) {
7664512e
FC
3803 yyerror(Perl_form(aTHX_ "Can't modify reference to "
3804 "localized parenthesized array in list assignment"));
3805 return;
3806 }
3807 slurpy:
b9a07097 3808 OpTYPE_set(o, OP_LVAVREF);
7664512e
FC
3809 o->op_private &= OPpLVAL_INTRO|OPpPAD_STATE;
3810 o->op_flags |= OPf_MOD|OPf_REF;
3811 return;
3812 }
3813 o->op_private |= OPpLVREF_AV;
3814 goto checkgv;
408e9044 3815 case OP_RV2CV:
19abb1ea
FC
3816 kid = cUNOPo->op_first;
3817 if (kid->op_type == OP_NULL)
cb748240 3818 kid = cUNOPx(OpSIBLING(kUNOP->op_first))
408e9044
FC
3819 ->op_first;
3820 o->op_private = OPpLVREF_CV;
3821 if (kid->op_type == OP_GV)
3822 o->op_flags |= OPf_STACKED;
3823 else if (kid->op_type == OP_PADCV) {
3824 o->op_targ = kid->op_targ;
3825 kid->op_targ = 0;
3826 op_free(cUNOPo->op_first);
3827 cUNOPo->op_first = NULL;
3828 o->op_flags &=~ OPf_KIDS;
3829 }
3830 else goto badref;
3831 break;
7664512e
FC
3832 case OP_RV2HV:
3833 if (o->op_flags & OPf_PARENS) {
3834 parenhash:
7664512e
FC
3835 yyerror(Perl_form(aTHX_ "Can't modify reference to "
3836 "parenthesized hash in list assignment"));
3837 return;
3838 }
3839 o->op_private |= OPpLVREF_HV;
3840 /* FALLTHROUGH */
3841 case OP_RV2SV:
3842 checkgv:
3843 if (cUNOPo->op_first->op_type != OP_GV) goto badref;
3844 o->op_flags |= OPf_STACKED;
6f5dab3c
FC
3845 break;
3846 case OP_PADHV:
3847 if (o->op_flags & OPf_PARENS) goto parenhash;
3848 o->op_private |= OPpLVREF_HV;
7664512e
FC
3849 /* FALLTHROUGH */
3850 case OP_PADSV:
6f5dab3c 3851 PAD_COMPNAME_GEN_set(o->op_targ, PERL_INT_MAX);
7664512e
FC
3852 break;
3853 case OP_PADAV:
6f5dab3c 3854 PAD_COMPNAME_GEN_set(o->op_targ, PERL_INT_MAX);
7664512e
FC
3855 if (o->op_flags & OPf_PARENS) goto slurpy;
3856 o->op_private |= OPpLVREF_AV;
3857 break;
7664512e
FC
3858 case OP_AELEM:
3859 case OP_HELEM:
3860 o->op_private |= OPpLVREF_ELEM;
3861 o->op_flags |= OPf_STACKED;
3862 break;
3863 case OP_ASLICE:
3864 case OP_HSLICE:
b9a07097 3865 OpTYPE_set(o, OP_LVREFSLICE);
36efb5a6 3866 o->op_private &= OPpLVAL_INTRO;
7664512e
FC
3867 return;
3868 case OP_NULL:
3869 if (o->op_flags & OPf_SPECIAL) /* do BLOCK */
3870 goto badref;
3871 else if (!(o->op_flags & OPf_KIDS))
3872 return;
3873 if (o->op_targ != OP_LIST) {
63702de8 3874 S_lvref(aTHX_ cBINOPo->op_first, type);
7664512e
FC
3875 return;
3876 }
3877 /* FALLTHROUGH */
3878 case OP_LIST:
e6dae479 3879 for (kid = cLISTOPo->op_first; kid; kid = OpSIBLING(kid)) {
7664512e 3880 assert((kid->op_flags & OPf_WANT) != OPf_WANT_VOID);
63702de8 3881 S_lvref(aTHX_ kid, type);
7664512e
FC
3882 }
3883 return;
3884 case OP_STUB:
3885 if (o->op_flags & OPf_PARENS)
3886 return;
3887 /* FALLTHROUGH */
3888 default:
3889 badref:
cf6e1fa1 3890 /* diag_listed_as: Can't modify reference to %s in %s assignment */
63702de8 3891 yyerror(Perl_form(aTHX_ "Can't modify reference to %s in %s",
7664512e
FC
3892 o->op_type == OP_NULL && o->op_flags & OPf_SPECIAL
3893 ? "do block"
63702de8
FC
3894 : OP_DESC(o),
3895 PL_op_desc[type]));
2b6a5bfb 3896 return;
7664512e 3897 }
b9a07097 3898 OpTYPE_set(o, OP_LVREF);
3ad7d304
FC
3899 o->op_private &=
3900 OPpLVAL_INTRO|OPpLVREF_ELEM|OPpLVREF_TYPE|OPpPAD_STATE;
d39c26a6
FC
3901 if (type == OP_ENTERLOOP)
3902 o->op_private |= OPpLVREF_ITER;
7664512e
FC
3903}
3904
1a3e9724
FC
3905PERL_STATIC_INLINE bool
3906S_potential_mod_type(I32 type)
3907{
3908 /* Types that only potentially result in modification. */
3909 return type == OP_GREPSTART || type == OP_ENTERSUB
3910 || type == OP_REFGEN || type == OP_LEAVESUBLV;
3911}
3912
79072805 3913OP *
d3d7d28f 3914Perl_op_lvalue_flags(pTHX_ OP *o, I32 type, U32 flags)
79072805 3915{
27da23d5 3916 dVAR;
79072805 3917 OP *kid;
ddeae0f1
DM
3918 /* -1 = error on localize, 0 = ignore localize, 1 = ok to localize */
3919 int localize = -1;
79072805 3920
13765c85 3921 if (!o || (PL_parser && PL_parser->error_count))
11343788 3922 return o;
79072805 3923
b162f9ea 3924 if ((o->op_private & OPpTARGET_MY)
7e363e51
GS
3925 && (PL_opargs[o->op_type] & OA_TARGLEX))/* OPp share the meaning */
3926 {
b162f9ea 3927 return o;
7e363e51 3928 }
1c846c1f 3929
5c906035
GG
3930 assert( (o->op_flags & OPf_WANT) != OPf_WANT_VOID );
3931
69974ce6
FC
3932 if (type == OP_PRTF || type == OP_SPRINTF) type = OP_ENTERSUB;
3933
11343788 3934 switch (o->op_type) {
68dc0745 3935 case OP_UNDEF:
3280af22