xref: /openbsd-src/gnu/usr.bin/perl/util.c (revision 4b70baf6e17fc8b27fc1f7fa7929335753fa94c3)
1 /*    util.c
2  *
3  *    Copyright (C) 1993, 1994, 1995, 1996, 1997, 1998, 1999, 2000, 2001,
4  *    2002, 2003, 2004, 2005, 2006, 2007, 2008 by Larry Wall and others
5  *
6  *    You may distribute under the terms of either the GNU General Public
7  *    License or the Artistic License, as specified in the README file.
8  *
9  */
10 
11 /*
12  * 'Very useful, no doubt, that was to Saruman; yet it seems that he was
13  *  not content.'                                    --Gandalf to Pippin
14  *
15  *     [p.598 of _The Lord of the Rings_, III/xi: "The Palantír"]
16  */
17 
18 /* This file contains assorted utility routines.
19  * Which is a polite way of saying any stuff that people couldn't think of
20  * a better place for. Amongst other things, it includes the warning and
21  * dieing stuff, plus wrappers for malloc code.
22  */
23 
24 #include "EXTERN.h"
25 #define PERL_IN_UTIL_C
26 #include "perl.h"
27 #include "reentr.h"
28 
29 #if defined(USE_PERLIO)
30 #include "perliol.h" /* For PerlIOUnix_refcnt */
31 #endif
32 
33 #ifndef PERL_MICRO
34 #include <signal.h>
35 #ifndef SIG_ERR
36 # define SIG_ERR ((Sighandler_t) -1)
37 #endif
38 #endif
39 
40 #include <math.h>
41 #include <stdlib.h>
42 
43 #ifdef __Lynx__
44 /* Missing protos on LynxOS */
45 int putenv(char *);
46 #endif
47 
48 #ifdef __amigaos__
49 # include "amigaos4/amigaio.h"
50 #endif
51 
52 #ifdef HAS_SELECT
53 # ifdef I_SYS_SELECT
54 #  include <sys/select.h>
55 # endif
56 #endif
57 
58 #ifdef USE_C_BACKTRACE
59 #  ifdef I_BFD
60 #    define USE_BFD
61 #    ifdef PERL_DARWIN
62 #      undef USE_BFD /* BFD is useless in OS X. */
63 #    endif
64 #    ifdef USE_BFD
65 #      include <bfd.h>
66 #    endif
67 #  endif
68 #  ifdef I_DLFCN
69 #    include <dlfcn.h>
70 #  endif
71 #  ifdef I_EXECINFO
72 #    include <execinfo.h>
73 #  endif
74 #endif
75 
76 #ifdef PERL_DEBUG_READONLY_COW
77 # include <sys/mman.h>
78 #endif
79 
80 #define FLUSH
81 
82 /* NOTE:  Do not call the next three routines directly.  Use the macros
83  * in handy.h, so that we can easily redefine everything to do tracking of
84  * allocated hunks back to the original New to track down any memory leaks.
85  * XXX This advice seems to be widely ignored :-(   --AD  August 1996.
86  */
87 
88 #if defined (DEBUGGING) || defined(PERL_IMPLICIT_SYS) || defined (PERL_TRACK_MEMPOOL)
89 #  define ALWAYS_NEED_THX
90 #endif
91 
92 #if defined(PERL_TRACK_MEMPOOL) && defined(PERL_DEBUG_READONLY_COW)
93 static void
94 S_maybe_protect_rw(pTHX_ struct perl_memory_debug_header *header)
95 {
96     if (header->readonly
97      && mprotect(header, header->size, PROT_READ|PROT_WRITE))
98 	Perl_warn(aTHX_ "mprotect for COW string %p %lu failed with %d",
99 			 header, header->size, errno);
100 }
101 
102 static void
103 S_maybe_protect_ro(pTHX_ struct perl_memory_debug_header *header)
104 {
105     if (header->readonly
106      && mprotect(header, header->size, PROT_READ))
107 	Perl_warn(aTHX_ "mprotect RW for COW string %p %lu failed with %d",
108 			 header, header->size, errno);
109 }
110 # define maybe_protect_rw(foo) S_maybe_protect_rw(aTHX_ foo)
111 # define maybe_protect_ro(foo) S_maybe_protect_ro(aTHX_ foo)
112 #else
113 # define maybe_protect_rw(foo) NOOP
114 # define maybe_protect_ro(foo) NOOP
115 #endif
116 
117 #if defined(PERL_TRACK_MEMPOOL) || defined(PERL_DEBUG_READONLY_COW)
118  /* Use memory_debug_header */
119 # define USE_MDH
120 # if (defined(PERL_POISON) && defined(PERL_TRACK_MEMPOOL)) \
121    || defined(PERL_DEBUG_READONLY_COW)
122 #  define MDH_HAS_SIZE
123 # endif
124 #endif
125 
126 /* paranoid version of system's malloc() */
127 
128 Malloc_t
129 Perl_safesysmalloc(MEM_SIZE size)
130 {
131 #ifdef ALWAYS_NEED_THX
132     dTHX;
133 #endif
134     Malloc_t ptr;
135 
136 #ifdef USE_MDH
137     if (size + PERL_MEMORY_DEBUG_HEADER_SIZE < size)
138         goto out_of_memory;
139     size += PERL_MEMORY_DEBUG_HEADER_SIZE;
140 #endif
141 #ifdef DEBUGGING
142     if ((SSize_t)size < 0)
143 	Perl_croak_nocontext("panic: malloc, size=%" UVuf, (UV) size);
144 #endif
145     if (!size) size = 1;	/* malloc(0) is NASTY on our system */
146 #ifdef PERL_DEBUG_READONLY_COW
147     if ((ptr = mmap(0, size, PROT_READ|PROT_WRITE,
148 		    MAP_ANON|MAP_PRIVATE, -1, 0)) == MAP_FAILED) {
149 	perror("mmap failed");
150 	abort();
151     }
152 #else
153     ptr = (Malloc_t)PerlMem_malloc(size?size:1);
154 #endif
155     PERL_ALLOC_CHECK(ptr);
156     if (ptr != NULL) {
157 #ifdef USE_MDH
158 	struct perl_memory_debug_header *const header
159 	    = (struct perl_memory_debug_header *)ptr;
160 #endif
161 
162 #ifdef PERL_POISON
163 	PoisonNew(((char *)ptr), size, char);
164 #endif
165 
166 #ifdef PERL_TRACK_MEMPOOL
167 	header->interpreter = aTHX;
168 	/* Link us into the list.  */
169 	header->prev = &PL_memory_debug_header;
170 	header->next = PL_memory_debug_header.next;
171 	PL_memory_debug_header.next = header;
172 	maybe_protect_rw(header->next);
173 	header->next->prev = header;
174 	maybe_protect_ro(header->next);
175 #  ifdef PERL_DEBUG_READONLY_COW
176 	header->readonly = 0;
177 #  endif
178 #endif
179 #ifdef MDH_HAS_SIZE
180 	header->size = size;
181 #endif
182 	ptr = (Malloc_t)((char*)ptr+PERL_MEMORY_DEBUG_HEADER_SIZE);
183 	DEBUG_m(PerlIO_printf(Perl_debug_log, "0x%" UVxf ": (%05ld) malloc %ld bytes\n",PTR2UV(ptr),(long)PL_an++,(long)size));
184 
185     }
186     else {
187 #ifdef USE_MDH
188       out_of_memory:
189 #endif
190         {
191 #ifndef ALWAYS_NEED_THX
192             dTHX;
193 #endif
194             if (PL_nomemok)
195                 ptr =  NULL;
196             else
197                 croak_no_mem();
198         }
199     }
200     return ptr;
201 }
202 
203 /* paranoid version of system's realloc() */
204 
205 Malloc_t
206 Perl_safesysrealloc(Malloc_t where,MEM_SIZE size)
207 {
208 #ifdef ALWAYS_NEED_THX
209     dTHX;
210 #endif
211     Malloc_t ptr;
212 #ifdef PERL_DEBUG_READONLY_COW
213     const MEM_SIZE oldsize = where
214 	? ((struct perl_memory_debug_header *)((char *)where - PERL_MEMORY_DEBUG_HEADER_SIZE))->size
215 	: 0;
216 #endif
217 
218     if (!size) {
219 	safesysfree(where);
220 	ptr = NULL;
221     }
222     else if (!where) {
223 	ptr = safesysmalloc(size);
224     }
225     else {
226 #ifdef USE_MDH
227 	where = (Malloc_t)((char*)where-PERL_MEMORY_DEBUG_HEADER_SIZE);
228         if (size + PERL_MEMORY_DEBUG_HEADER_SIZE < size)
229             goto out_of_memory;
230 	size += PERL_MEMORY_DEBUG_HEADER_SIZE;
231 	{
232 	    struct perl_memory_debug_header *const header
233 		= (struct perl_memory_debug_header *)where;
234 
235 # ifdef PERL_TRACK_MEMPOOL
236 	    if (header->interpreter != aTHX) {
237 		Perl_croak_nocontext("panic: realloc from wrong pool, %p!=%p",
238 				     header->interpreter, aTHX);
239 	    }
240 	    assert(header->next->prev == header);
241 	    assert(header->prev->next == header);
242 #  ifdef PERL_POISON
243 	    if (header->size > size) {
244 		const MEM_SIZE freed_up = header->size - size;
245 		char *start_of_freed = ((char *)where) + size;
246 		PoisonFree(start_of_freed, freed_up, char);
247 	    }
248 #  endif
249 # endif
250 # ifdef MDH_HAS_SIZE
251 	    header->size = size;
252 # endif
253 	}
254 #endif
255 #ifdef DEBUGGING
256 	if ((SSize_t)size < 0)
257 	    Perl_croak_nocontext("panic: realloc, size=%" UVuf, (UV)size);
258 #endif
259 #ifdef PERL_DEBUG_READONLY_COW
260 	if ((ptr = mmap(0, size, PROT_READ|PROT_WRITE,
261 			MAP_ANON|MAP_PRIVATE, -1, 0)) == MAP_FAILED) {
262 	    perror("mmap failed");
263 	    abort();
264 	}
265 	Copy(where,ptr,oldsize < size ? oldsize : size,char);
266 	if (munmap(where, oldsize)) {
267 	    perror("munmap failed");
268 	    abort();
269 	}
270 #else
271 	ptr = (Malloc_t)PerlMem_realloc(where,size);
272 #endif
273 	PERL_ALLOC_CHECK(ptr);
274 
275     /* MUST do this fixup first, before doing ANYTHING else, as anything else
276        might allocate memory/free/move memory, and until we do the fixup, it
277        may well be chasing (and writing to) free memory.  */
278 	if (ptr != NULL) {
279 #ifdef PERL_TRACK_MEMPOOL
280 	    struct perl_memory_debug_header *const header
281 		= (struct perl_memory_debug_header *)ptr;
282 
283 #  ifdef PERL_POISON
284 	    if (header->size < size) {
285 		const MEM_SIZE fresh = size - header->size;
286 		char *start_of_fresh = ((char *)ptr) + size;
287 		PoisonNew(start_of_fresh, fresh, char);
288 	    }
289 #  endif
290 
291 	    maybe_protect_rw(header->next);
292 	    header->next->prev = header;
293 	    maybe_protect_ro(header->next);
294 	    maybe_protect_rw(header->prev);
295 	    header->prev->next = header;
296 	    maybe_protect_ro(header->prev);
297 #endif
298 	    ptr = (Malloc_t)((char*)ptr+PERL_MEMORY_DEBUG_HEADER_SIZE);
299 	}
300 
301     /* In particular, must do that fixup above before logging anything via
302      *printf(), as it can reallocate memory, which can cause SEGVs.  */
303 
304 	DEBUG_m(PerlIO_printf(Perl_debug_log, "0x%" UVxf ": (%05ld) rfree\n",PTR2UV(where),(long)PL_an++));
305 	DEBUG_m(PerlIO_printf(Perl_debug_log, "0x%" UVxf ": (%05ld) realloc %ld bytes\n",PTR2UV(ptr),(long)PL_an++,(long)size));
306 
307 	if (ptr == NULL) {
308 #ifdef USE_MDH
309           out_of_memory:
310 #endif
311             {
312 #ifndef ALWAYS_NEED_THX
313                 dTHX;
314 #endif
315                 if (PL_nomemok)
316                     ptr = NULL;
317                 else
318                     croak_no_mem();
319             }
320 	}
321     }
322     return ptr;
323 }
324 
325 /* safe version of system's free() */
326 
327 Free_t
328 Perl_safesysfree(Malloc_t where)
329 {
330 #ifdef ALWAYS_NEED_THX
331     dTHX;
332 #endif
333     DEBUG_m( PerlIO_printf(Perl_debug_log, "0x%" UVxf ": (%05ld) free\n",PTR2UV(where),(long)PL_an++));
334     if (where) {
335 #ifdef USE_MDH
336 	Malloc_t where_intrn = (Malloc_t)((char*)where-PERL_MEMORY_DEBUG_HEADER_SIZE);
337 	{
338 	    struct perl_memory_debug_header *const header
339 		= (struct perl_memory_debug_header *)where_intrn;
340 
341 # ifdef MDH_HAS_SIZE
342 	    const MEM_SIZE size = header->size;
343 # endif
344 # ifdef PERL_TRACK_MEMPOOL
345 	    if (header->interpreter != aTHX) {
346 		Perl_croak_nocontext("panic: free from wrong pool, %p!=%p",
347 				     header->interpreter, aTHX);
348 	    }
349 	    if (!header->prev) {
350 		Perl_croak_nocontext("panic: duplicate free");
351 	    }
352 	    if (!(header->next))
353 		Perl_croak_nocontext("panic: bad free, header->next==NULL");
354 	    if (header->next->prev != header || header->prev->next != header) {
355 		Perl_croak_nocontext("panic: bad free, ->next->prev=%p, "
356 				     "header=%p, ->prev->next=%p",
357 				     header->next->prev, header,
358 				     header->prev->next);
359 	    }
360 	    /* Unlink us from the chain.  */
361 	    maybe_protect_rw(header->next);
362 	    header->next->prev = header->prev;
363 	    maybe_protect_ro(header->next);
364 	    maybe_protect_rw(header->prev);
365 	    header->prev->next = header->next;
366 	    maybe_protect_ro(header->prev);
367 	    maybe_protect_rw(header);
368 #  ifdef PERL_POISON
369 	    PoisonNew(where_intrn, size, char);
370 #  endif
371 	    /* Trigger the duplicate free warning.  */
372 	    header->next = NULL;
373 # endif
374 # ifdef PERL_DEBUG_READONLY_COW
375 	    if (munmap(where_intrn, size)) {
376 		perror("munmap failed");
377 		abort();
378 	    }
379 # endif
380 	}
381 #else
382 	Malloc_t where_intrn = where;
383 #endif /* USE_MDH */
384 #ifndef PERL_DEBUG_READONLY_COW
385 	PerlMem_free(where_intrn);
386 #endif
387     }
388 }
389 
390 /* safe version of system's calloc() */
391 
392 Malloc_t
393 Perl_safesyscalloc(MEM_SIZE count, MEM_SIZE size)
394 {
395 #ifdef ALWAYS_NEED_THX
396     dTHX;
397 #endif
398     Malloc_t ptr;
399 #if defined(USE_MDH) || defined(DEBUGGING)
400     MEM_SIZE total_size = 0;
401 #endif
402 
403     /* Even though calloc() for zero bytes is strange, be robust. */
404     if (size && (count <= MEM_SIZE_MAX / size)) {
405 #if defined(USE_MDH) || defined(DEBUGGING)
406 	total_size = size * count;
407 #endif
408     }
409     else
410 	croak_memory_wrap();
411 #ifdef USE_MDH
412     if (PERL_MEMORY_DEBUG_HEADER_SIZE <= MEM_SIZE_MAX - (MEM_SIZE)total_size)
413 	total_size += PERL_MEMORY_DEBUG_HEADER_SIZE;
414     else
415 	croak_memory_wrap();
416 #endif
417 #ifdef DEBUGGING
418     if ((SSize_t)size < 0 || (SSize_t)count < 0)
419 	Perl_croak_nocontext("panic: calloc, size=%" UVuf ", count=%" UVuf,
420 			     (UV)size, (UV)count);
421 #endif
422 #ifdef PERL_DEBUG_READONLY_COW
423     if ((ptr = mmap(0, total_size ? total_size : 1, PROT_READ|PROT_WRITE,
424 		    MAP_ANON|MAP_PRIVATE, -1, 0)) == MAP_FAILED) {
425 	perror("mmap failed");
426 	abort();
427     }
428 #elif defined(PERL_TRACK_MEMPOOL)
429     /* Have to use malloc() because we've added some space for our tracking
430        header.  */
431     /* malloc(0) is non-portable. */
432     ptr = (Malloc_t)PerlMem_malloc(total_size ? total_size : 1);
433 #else
434     /* Use calloc() because it might save a memset() if the memory is fresh
435        and clean from the OS.  */
436     if (count && size)
437 	ptr = (Malloc_t)PerlMem_calloc(count, size);
438     else /* calloc(0) is non-portable. */
439 	ptr = (Malloc_t)PerlMem_calloc(count ? count : 1, size ? size : 1);
440 #endif
441     PERL_ALLOC_CHECK(ptr);
442     DEBUG_m(PerlIO_printf(Perl_debug_log, "0x%" UVxf ": (%05ld) calloc %ld x %ld bytes\n",PTR2UV(ptr),(long)PL_an++,(long)count,(long)total_size));
443     if (ptr != NULL) {
444 #ifdef USE_MDH
445 	{
446 	    struct perl_memory_debug_header *const header
447 		= (struct perl_memory_debug_header *)ptr;
448 
449 #  ifndef PERL_DEBUG_READONLY_COW
450 	    memset((void*)ptr, 0, total_size);
451 #  endif
452 #  ifdef PERL_TRACK_MEMPOOL
453 	    header->interpreter = aTHX;
454 	    /* Link us into the list.  */
455 	    header->prev = &PL_memory_debug_header;
456 	    header->next = PL_memory_debug_header.next;
457 	    PL_memory_debug_header.next = header;
458 	    maybe_protect_rw(header->next);
459 	    header->next->prev = header;
460 	    maybe_protect_ro(header->next);
461 #    ifdef PERL_DEBUG_READONLY_COW
462 	    header->readonly = 0;
463 #    endif
464 #  endif
465 #  ifdef MDH_HAS_SIZE
466 	    header->size = total_size;
467 #  endif
468 	    ptr = (Malloc_t)((char*)ptr+PERL_MEMORY_DEBUG_HEADER_SIZE);
469 	}
470 #endif
471 	return ptr;
472     }
473     else {
474 #ifndef ALWAYS_NEED_THX
475 	dTHX;
476 #endif
477 	if (PL_nomemok)
478 	    return NULL;
479 	croak_no_mem();
480     }
481 }
482 
483 /* These must be defined when not using Perl's malloc for binary
484  * compatibility */
485 
486 #ifndef MYMALLOC
487 
488 Malloc_t Perl_malloc (MEM_SIZE nbytes)
489 {
490 #ifdef PERL_IMPLICIT_SYS
491     dTHX;
492 #endif
493     return (Malloc_t)PerlMem_malloc(nbytes);
494 }
495 
496 Malloc_t Perl_calloc (MEM_SIZE elements, MEM_SIZE size)
497 {
498 #ifdef PERL_IMPLICIT_SYS
499     dTHX;
500 #endif
501     return (Malloc_t)PerlMem_calloc(elements, size);
502 }
503 
504 Malloc_t Perl_realloc (Malloc_t where, MEM_SIZE nbytes)
505 {
506 #ifdef PERL_IMPLICIT_SYS
507     dTHX;
508 #endif
509     return (Malloc_t)PerlMem_realloc(where, nbytes);
510 }
511 
512 Free_t   Perl_mfree (Malloc_t where)
513 {
514 #ifdef PERL_IMPLICIT_SYS
515     dTHX;
516 #endif
517     PerlMem_free(where);
518 }
519 
520 #endif
521 
522 /* copy a string up to some (non-backslashed) delimiter, if any.
523  * With allow_escape, converts \<delimiter> to <delimiter>, while leaves
524  * \<non-delimiter> as-is.
525  * Returns the position in the src string of the closing delimiter, if
526  * any, or returns fromend otherwise.
527  * This is the internal implementation for Perl_delimcpy and
528  * Perl_delimcpy_no_escape.
529  */
530 
531 static char *
532 S_delimcpy_intern(char *to, const char *toend, const char *from,
533 	   const char *fromend, int delim, I32 *retlen,
534 	   const bool allow_escape)
535 {
536     I32 tolen;
537 
538     PERL_ARGS_ASSERT_DELIMCPY;
539 
540     for (tolen = 0; from < fromend; from++, tolen++) {
541 	if (allow_escape && *from == '\\' && from + 1 < fromend) {
542 	    if (from[1] != delim) {
543 		if (to < toend)
544 		    *to++ = *from;
545 		tolen++;
546 	    }
547 	    from++;
548 	}
549 	else if (*from == delim)
550 	    break;
551 	if (to < toend)
552 	    *to++ = *from;
553     }
554     if (to < toend)
555 	*to = '\0';
556     *retlen = tolen;
557     return (char *)from;
558 }
559 
560 char *
561 Perl_delimcpy(char *to, const char *toend, const char *from, const char *fromend, int delim, I32 *retlen)
562 {
563     PERL_ARGS_ASSERT_DELIMCPY;
564 
565     return S_delimcpy_intern(to, toend, from, fromend, delim, retlen, 1);
566 }
567 
568 char *
569 Perl_delimcpy_no_escape(char *to, const char *toend, const char *from,
570 			const char *fromend, int delim, I32 *retlen)
571 {
572     PERL_ARGS_ASSERT_DELIMCPY_NO_ESCAPE;
573 
574     return S_delimcpy_intern(to, toend, from, fromend, delim, retlen, 0);
575 }
576 
577 /*
578 =head1 Miscellaneous Functions
579 
580 =for apidoc Am|char *|ninstr|char * big|char * bigend|char * little|char * little_end
581 
582 Find the first (leftmost) occurrence of a sequence of bytes within another
583 sequence.  This is the Perl version of C<strstr()>, extended to handle
584 arbitrary sequences, potentially containing embedded C<NUL> characters (C<NUL>
585 is what the initial C<n> in the function name stands for; some systems have an
586 equivalent, C<memmem()>, but with a somewhat different API).
587 
588 Another way of thinking about this function is finding a needle in a haystack.
589 C<big> points to the first byte in the haystack.  C<big_end> points to one byte
590 beyond the final byte in the haystack.  C<little> points to the first byte in
591 the needle.  C<little_end> points to one byte beyond the final byte in the
592 needle.  All the parameters must be non-C<NULL>.
593 
594 The function returns C<NULL> if there is no occurrence of C<little> within
595 C<big>.  If C<little> is the empty string, C<big> is returned.
596 
597 Because this function operates at the byte level, and because of the inherent
598 characteristics of UTF-8 (or UTF-EBCDIC), it will work properly if both the
599 needle and the haystack are strings with the same UTF-8ness, but not if the
600 UTF-8ness differs.
601 
602 =cut
603 
604 */
605 
606 char *
607 Perl_ninstr(const char *big, const char *bigend, const char *little, const char *lend)
608 {
609     PERL_ARGS_ASSERT_NINSTR;
610 
611 #ifdef HAS_MEMMEM
612     return ninstr(big, bigend, little, lend);
613 #else
614 
615     if (little >= lend)
616         return (char*)big;
617     {
618         const char first = *little;
619         bigend -= lend - little++;
620     OUTER:
621         while (big <= bigend) {
622             if (*big++ == first) {
623                 const char *s, *x;
624                 for (x=big,s=little; s < lend; x++,s++) {
625                     if (*s != *x)
626                         goto OUTER;
627                 }
628                 return (char*)(big-1);
629             }
630         }
631     }
632     return NULL;
633 
634 #endif
635 
636 }
637 
638 /*
639 =head1 Miscellaneous Functions
640 
641 =for apidoc Am|char *|rninstr|char * big|char * bigend|char * little|char * little_end
642 
643 Like C<L</ninstr>>, but instead finds the final (rightmost) occurrence of a
644 sequence of bytes within another sequence, returning C<NULL> if there is no
645 such occurrence.
646 
647 =cut
648 
649 */
650 
651 char *
652 Perl_rninstr(const char *big, const char *bigend, const char *little, const char *lend)
653 {
654     const char *bigbeg;
655     const I32 first = *little;
656     const char * const littleend = lend;
657 
658     PERL_ARGS_ASSERT_RNINSTR;
659 
660     if (little >= littleend)
661 	return (char*)bigend;
662     bigbeg = big;
663     big = bigend - (littleend - little++);
664     while (big >= bigbeg) {
665 	const char *s, *x;
666 	if (*big-- != first)
667 	    continue;
668 	for (x=big+2,s=little; s < littleend; /**/ ) {
669 	    if (*s != *x)
670 		break;
671 	    else {
672 		x++;
673 		s++;
674 	    }
675 	}
676 	if (s >= littleend)
677 	    return (char*)(big+1);
678     }
679     return NULL;
680 }
681 
682 /* As a space optimization, we do not compile tables for strings of length
683    0 and 1, and for strings of length 2 unless FBMcf_TAIL.  These are
684    special-cased in fbm_instr().
685 
686    If FBMcf_TAIL, the table is created as if the string has a trailing \n. */
687 
688 /*
689 =head1 Miscellaneous Functions
690 
691 =for apidoc fbm_compile
692 
693 Analyzes the string in order to make fast searches on it using C<fbm_instr()>
694 -- the Boyer-Moore algorithm.
695 
696 =cut
697 */
698 
699 void
700 Perl_fbm_compile(pTHX_ SV *sv, U32 flags)
701 {
702     const U8 *s;
703     STRLEN i;
704     STRLEN len;
705     U32 frequency = 256;
706     MAGIC *mg;
707     PERL_DEB( STRLEN rarest = 0 );
708 
709     PERL_ARGS_ASSERT_FBM_COMPILE;
710 
711     if (isGV_with_GP(sv) || SvROK(sv))
712 	return;
713 
714     if (SvVALID(sv))
715 	return;
716 
717     if (flags & FBMcf_TAIL) {
718 	MAGIC * const mg = SvUTF8(sv) && SvMAGICAL(sv) ? mg_find(sv, PERL_MAGIC_utf8) : NULL;
719 	sv_catpvs(sv, "\n");		/* Taken into account in fbm_instr() */
720 	if (mg && mg->mg_len >= 0)
721 	    mg->mg_len++;
722     }
723     if (!SvPOK(sv) || SvNIOKp(sv))
724 	s = (U8*)SvPV_force_mutable(sv, len);
725     else s = (U8 *)SvPV_mutable(sv, len);
726     if (len == 0)		/* TAIL might be on a zero-length string. */
727 	return;
728     SvUPGRADE(sv, SVt_PVMG);
729     SvIOK_off(sv);
730     SvNOK_off(sv);
731 
732     /* add PERL_MAGIC_bm magic holding the FBM lookup table */
733 
734     assert(!mg_find(sv, PERL_MAGIC_bm));
735     mg = sv_magicext(sv, NULL, PERL_MAGIC_bm, &PL_vtbl_bm, NULL, 0);
736     assert(mg);
737 
738     if (len > 2) {
739 	/* Shorter strings are special-cased in Perl_fbm_instr(), and don't use
740 	   the BM table.  */
741 	const U8 mlen = (len>255) ? 255 : (U8)len;
742 	const unsigned char *const sb = s + len - mlen; /* first char (maybe) */
743 	U8 *table;
744 
745 	Newx(table, 256, U8);
746 	memset((void*)table, mlen, 256);
747 	mg->mg_ptr = (char *)table;
748 	mg->mg_len = 256;
749 
750 	s += len - 1; /* last char */
751 	i = 0;
752 	while (s >= sb) {
753 	    if (table[*s] == mlen)
754 		table[*s] = (U8)i;
755 	    s--, i++;
756 	}
757     }
758 
759     s = (const unsigned char*)(SvPVX_const(sv));	/* deeper magic */
760     for (i = 0; i < len; i++) {
761 	if (PL_freq[s[i]] < frequency) {
762 	    PERL_DEB( rarest = i );
763 	    frequency = PL_freq[s[i]];
764 	}
765     }
766     BmUSEFUL(sv) = 100;			/* Initial value */
767     ((XPVNV*)SvANY(sv))->xnv_u.xnv_bm_tail = cBOOL(flags & FBMcf_TAIL);
768     DEBUG_r(PerlIO_printf(Perl_debug_log, "rarest char %c at %" UVuf "\n",
769 			  s[rarest], (UV)rarest));
770 }
771 
772 
773 /*
774 =for apidoc fbm_instr
775 
776 Returns the location of the SV in the string delimited by C<big> and
777 C<bigend> (C<bigend>) is the char following the last char).
778 It returns C<NULL> if the string can't be found.  The C<sv>
779 does not have to be C<fbm_compiled>, but the search will not be as fast
780 then.
781 
782 =cut
783 
784 If SvTAIL(littlestr) is true, a fake "\n" was appended to to the string
785 during FBM compilation due to FBMcf_TAIL in flags. It indicates that
786 the littlestr must be anchored to the end of bigstr (or to any \n if
787 FBMrf_MULTILINE).
788 
789 E.g. The regex compiler would compile /abc/ to a littlestr of "abc",
790 while /abc$/ compiles to "abc\n" with SvTAIL() true.
791 
792 A littlestr of "abc", !SvTAIL matches as /abc/;
793 a littlestr of "ab\n", SvTAIL matches as:
794    without FBMrf_MULTILINE: /ab\n?\z/
795    with    FBMrf_MULTILINE: /ab\n/ || /ab\z/;
796 
797 (According to Ilya from 1999; I don't know if this is still true, DAPM 2015):
798   "If SvTAIL is actually due to \Z or \z, this gives false positives
799   if multiline".
800 */
801 
802 
803 char *
804 Perl_fbm_instr(pTHX_ unsigned char *big, unsigned char *bigend, SV *littlestr, U32 flags)
805 {
806     unsigned char *s;
807     STRLEN l;
808     const unsigned char *little = (const unsigned char *)SvPV_const(littlestr,l);
809     STRLEN littlelen = l;
810     const I32 multiline = flags & FBMrf_MULTILINE;
811     bool valid = SvVALID(littlestr);
812     bool tail = valid ? cBOOL(SvTAIL(littlestr)) : FALSE;
813 
814     PERL_ARGS_ASSERT_FBM_INSTR;
815 
816     assert(bigend >= big);
817 
818     if ((STRLEN)(bigend - big) < littlelen) {
819 	if (     tail
820 	     && ((STRLEN)(bigend - big) == littlelen - 1)
821 	     && (littlelen == 1
822 		 || (*big == *little &&
823 		     memEQ((char *)big, (char *)little, littlelen - 1))))
824 	    return (char*)big;
825 	return NULL;
826     }
827 
828     switch (littlelen) { /* Special cases for 0, 1 and 2  */
829     case 0:
830 	return (char*)big;		/* Cannot be SvTAIL! */
831 
832     case 1:
833 	    if (tail && !multiline) /* Anchor only! */
834 		/* [-1] is safe because we know that bigend != big.  */
835 		return (char *) (bigend - (bigend[-1] == '\n'));
836 
837 	    s = (unsigned char *)memchr((void*)big, *little, bigend-big);
838             if (s)
839                 return (char *)s;
840 	    if (tail)
841 		return (char *) bigend;
842 	    return NULL;
843 
844     case 2:
845 	if (tail && !multiline) {
846             /* a littlestr with SvTAIL must be of the form "X\n" (where X
847              * is a single char). It is anchored, and can only match
848              * "....X\n"  or  "....X" */
849             if (bigend[-2] == *little && bigend[-1] == '\n')
850 		return (char*)bigend - 2;
851 	    if (bigend[-1] == *little)
852 		return (char*)bigend - 1;
853 	    return NULL;
854 	}
855 
856 	{
857             /* memchr() is likely to be very fast, possibly using whatever
858              * hardware support is available, such as checking a whole
859              * cache line in one instruction.
860              * So for a 2 char pattern, calling memchr() is likely to be
861              * faster than running FBM, or rolling our own. The previous
862              * version of this code was roll-your-own which typically
863              * only needed to read every 2nd char, which was good back in
864              * the day, but no longer.
865              */
866 	    unsigned char c1 = little[0];
867 	    unsigned char c2 = little[1];
868 
869             /* *** for all this case, bigend points to the last char,
870              * not the trailing \0: this makes the conditions slightly
871              * simpler */
872             bigend--;
873 	    s = big;
874             if (c1 != c2) {
875                 while (s < bigend) {
876                     /* do a quick test for c1 before calling memchr();
877                      * this avoids the expensive fn call overhead when
878                      * there are lots of c1's */
879                     if (LIKELY(*s != c1)) {
880                         s++;
881                         s = (unsigned char *)memchr((void*)s, c1, bigend - s);
882                         if (!s)
883                             break;
884                     }
885                     if (s[1] == c2)
886                         return (char*)s;
887 
888                     /* failed; try searching for c2 this time; that way
889                      * we don't go pathologically slow when the string
890                      * consists mostly of c1's or vice versa.
891                      */
892                     s += 2;
893                     if (s > bigend)
894                         break;
895                     s = (unsigned char *)memchr((void*)s, c2, bigend - s + 1);
896                     if (!s)
897                         break;
898                     if (s[-1] == c1)
899                         return (char*)s - 1;
900                 }
901             }
902             else {
903                 /* c1, c2 the same */
904                 while (s < bigend) {
905                     if (s[0] == c1) {
906                       got_1char:
907                         if (s[1] == c1)
908                             return (char*)s;
909                         s += 2;
910                     }
911                     else {
912                         s++;
913                         s = (unsigned char *)memchr((void*)s, c1, bigend - s);
914                         if (!s || s >= bigend)
915                             break;
916                         goto got_1char;
917                     }
918                 }
919             }
920 
921             /* failed to find 2 chars; try anchored match at end without
922              * the \n */
923             if (tail && bigend[0] == little[0])
924                 return (char *)bigend;
925             return NULL;
926         }
927 
928     default:
929 	break; /* Only lengths 0 1 and 2 have special-case code.  */
930     }
931 
932     if (tail && !multiline) {	/* tail anchored? */
933 	s = bigend - littlelen;
934 	if (s >= big && bigend[-1] == '\n' && *s == *little
935 	    /* Automatically of length > 2 */
936 	    && memEQ((char*)s + 1, (char*)little + 1, littlelen - 2))
937 	{
938 	    return (char*)s;		/* how sweet it is */
939 	}
940 	if (s[1] == *little
941 	    && memEQ((char*)s + 2, (char*)little + 1, littlelen - 2))
942 	{
943 	    return (char*)s + 1;	/* how sweet it is */
944 	}
945 	return NULL;
946     }
947 
948     if (!valid) {
949         /* not compiled; use Perl_ninstr() instead */
950 	char * const b = ninstr((char*)big,(char*)bigend,
951 			 (char*)little, (char*)little + littlelen);
952 
953         assert(!tail); /* valid => FBM; tail only set on SvVALID SVs */
954 	return b;
955     }
956 
957     /* Do actual FBM.  */
958     if (littlelen > (STRLEN)(bigend - big))
959 	return NULL;
960 
961     {
962 	const MAGIC *const mg = mg_find(littlestr, PERL_MAGIC_bm);
963 	const unsigned char *oldlittle;
964 
965 	assert(mg);
966 
967 	--littlelen;			/* Last char found by table lookup */
968 
969 	s = big + littlelen;
970 	little += littlelen;		/* last char */
971 	oldlittle = little;
972 	if (s < bigend) {
973 	    const unsigned char * const table = (const unsigned char *) mg->mg_ptr;
974             const unsigned char lastc = *little;
975 	    I32 tmp;
976 
977 	  top2:
978 	    if ((tmp = table[*s])) {
979                 /* *s != lastc; earliest position it could match now is
980                  * tmp slots further on */
981 		if ((s += tmp) >= bigend)
982                     goto check_end;
983                 if (LIKELY(*s != lastc)) {
984                     s++;
985                     s = (unsigned char *)memchr((void*)s, lastc, bigend - s);
986                     if (!s) {
987                         s = bigend;
988                         goto check_end;
989                     }
990                     goto top2;
991                 }
992 	    }
993 
994 
995             /* hand-rolled strncmp(): less expensive than calling the
996              * real function (maybe???) */
997 	    {
998 		unsigned char * const olds = s;
999 
1000 		tmp = littlelen;
1001 
1002 		while (tmp--) {
1003 		    if (*--s == *--little)
1004 			continue;
1005 		    s = olds + 1;	/* here we pay the price for failure */
1006 		    little = oldlittle;
1007 		    if (s < bigend)	/* fake up continue to outer loop */
1008 			goto top2;
1009 		    goto check_end;
1010 		}
1011 		return (char *)s;
1012 	    }
1013 	}
1014       check_end:
1015 	if ( s == bigend
1016 	     && tail
1017 	     && memEQ((char *)(bigend - littlelen),
1018 		      (char *)(oldlittle - littlelen), littlelen) )
1019 	    return (char*)bigend - littlelen;
1020 	return NULL;
1021     }
1022 }
1023 
1024 /* copy a string to a safe spot */
1025 
1026 /*
1027 =head1 Memory Management
1028 
1029 =for apidoc savepv
1030 
1031 Perl's version of C<strdup()>.  Returns a pointer to a newly allocated
1032 string which is a duplicate of C<pv>.  The size of the string is
1033 determined by C<strlen()>, which means it may not contain embedded C<NUL>
1034 characters and must have a trailing C<NUL>.  The memory allocated for the new
1035 string can be freed with the C<Safefree()> function.
1036 
1037 On some platforms, Windows for example, all allocated memory owned by a thread
1038 is deallocated when that thread ends.  So if you need that not to happen, you
1039 need to use the shared memory functions, such as C<L</savesharedpv>>.
1040 
1041 =cut
1042 */
1043 
1044 char *
1045 Perl_savepv(pTHX_ const char *pv)
1046 {
1047     PERL_UNUSED_CONTEXT;
1048     if (!pv)
1049 	return NULL;
1050     else {
1051 	char *newaddr;
1052 	const STRLEN pvlen = strlen(pv)+1;
1053 	Newx(newaddr, pvlen, char);
1054 	return (char*)memcpy(newaddr, pv, pvlen);
1055     }
1056 }
1057 
1058 /* same thing but with a known length */
1059 
1060 /*
1061 =for apidoc savepvn
1062 
1063 Perl's version of what C<strndup()> would be if it existed.  Returns a
1064 pointer to a newly allocated string which is a duplicate of the first
1065 C<len> bytes from C<pv>, plus a trailing
1066 C<NUL> byte.  The memory allocated for
1067 the new string can be freed with the C<Safefree()> function.
1068 
1069 On some platforms, Windows for example, all allocated memory owned by a thread
1070 is deallocated when that thread ends.  So if you need that not to happen, you
1071 need to use the shared memory functions, such as C<L</savesharedpvn>>.
1072 
1073 =cut
1074 */
1075 
1076 char *
1077 Perl_savepvn(pTHX_ const char *pv, I32 len)
1078 {
1079     char *newaddr;
1080     PERL_UNUSED_CONTEXT;
1081 
1082     assert(len >= 0);
1083 
1084     Newx(newaddr,len+1,char);
1085     /* Give a meaning to NULL pointer mainly for the use in sv_magic() */
1086     if (pv) {
1087 	/* might not be null terminated */
1088     	newaddr[len] = '\0';
1089     	return (char *) CopyD(pv,newaddr,len,char);
1090     }
1091     else {
1092 	return (char *) ZeroD(newaddr,len+1,char);
1093     }
1094 }
1095 
1096 /*
1097 =for apidoc savesharedpv
1098 
1099 A version of C<savepv()> which allocates the duplicate string in memory
1100 which is shared between threads.
1101 
1102 =cut
1103 */
1104 char *
1105 Perl_savesharedpv(pTHX_ const char *pv)
1106 {
1107     char *newaddr;
1108     STRLEN pvlen;
1109 
1110     PERL_UNUSED_CONTEXT;
1111 
1112     if (!pv)
1113 	return NULL;
1114 
1115     pvlen = strlen(pv)+1;
1116     newaddr = (char*)PerlMemShared_malloc(pvlen);
1117     if (!newaddr) {
1118 	croak_no_mem();
1119     }
1120     return (char*)memcpy(newaddr, pv, pvlen);
1121 }
1122 
1123 /*
1124 =for apidoc savesharedpvn
1125 
1126 A version of C<savepvn()> which allocates the duplicate string in memory
1127 which is shared between threads.  (With the specific difference that a C<NULL>
1128 pointer is not acceptable)
1129 
1130 =cut
1131 */
1132 char *
1133 Perl_savesharedpvn(pTHX_ const char *const pv, const STRLEN len)
1134 {
1135     char *const newaddr = (char*)PerlMemShared_malloc(len + 1);
1136 
1137     PERL_UNUSED_CONTEXT;
1138     /* PERL_ARGS_ASSERT_SAVESHAREDPVN; */
1139 
1140     if (!newaddr) {
1141 	croak_no_mem();
1142     }
1143     newaddr[len] = '\0';
1144     return (char*)memcpy(newaddr, pv, len);
1145 }
1146 
1147 /*
1148 =for apidoc savesvpv
1149 
1150 A version of C<savepv()>/C<savepvn()> which gets the string to duplicate from
1151 the passed in SV using C<SvPV()>
1152 
1153 On some platforms, Windows for example, all allocated memory owned by a thread
1154 is deallocated when that thread ends.  So if you need that not to happen, you
1155 need to use the shared memory functions, such as C<L</savesharedsvpv>>.
1156 
1157 =cut
1158 */
1159 
1160 char *
1161 Perl_savesvpv(pTHX_ SV *sv)
1162 {
1163     STRLEN len;
1164     const char * const pv = SvPV_const(sv, len);
1165     char *newaddr;
1166 
1167     PERL_ARGS_ASSERT_SAVESVPV;
1168 
1169     ++len;
1170     Newx(newaddr,len,char);
1171     return (char *) CopyD(pv,newaddr,len,char);
1172 }
1173 
1174 /*
1175 =for apidoc savesharedsvpv
1176 
1177 A version of C<savesharedpv()> which allocates the duplicate string in
1178 memory which is shared between threads.
1179 
1180 =cut
1181 */
1182 
1183 char *
1184 Perl_savesharedsvpv(pTHX_ SV *sv)
1185 {
1186     STRLEN len;
1187     const char * const pv = SvPV_const(sv, len);
1188 
1189     PERL_ARGS_ASSERT_SAVESHAREDSVPV;
1190 
1191     return savesharedpvn(pv, len);
1192 }
1193 
1194 /* the SV for Perl_form() and mess() is not kept in an arena */
1195 
1196 STATIC SV *
1197 S_mess_alloc(pTHX)
1198 {
1199     SV *sv;
1200     XPVMG *any;
1201 
1202     if (PL_phase != PERL_PHASE_DESTRUCT)
1203 	return newSVpvs_flags("", SVs_TEMP);
1204 
1205     if (PL_mess_sv)
1206 	return PL_mess_sv;
1207 
1208     /* Create as PVMG now, to avoid any upgrading later */
1209     Newx(sv, 1, SV);
1210     Newxz(any, 1, XPVMG);
1211     SvFLAGS(sv) = SVt_PVMG;
1212     SvANY(sv) = (void*)any;
1213     SvPV_set(sv, NULL);
1214     SvREFCNT(sv) = 1 << 30; /* practically infinite */
1215     PL_mess_sv = sv;
1216     return sv;
1217 }
1218 
1219 #if defined(PERL_IMPLICIT_CONTEXT)
1220 char *
1221 Perl_form_nocontext(const char* pat, ...)
1222 {
1223     dTHX;
1224     char *retval;
1225     va_list args;
1226     PERL_ARGS_ASSERT_FORM_NOCONTEXT;
1227     va_start(args, pat);
1228     retval = vform(pat, &args);
1229     va_end(args);
1230     return retval;
1231 }
1232 #endif /* PERL_IMPLICIT_CONTEXT */
1233 
1234 /*
1235 =head1 Miscellaneous Functions
1236 =for apidoc form
1237 
1238 Takes a sprintf-style format pattern and conventional
1239 (non-SV) arguments and returns the formatted string.
1240 
1241     (char *) Perl_form(pTHX_ const char* pat, ...)
1242 
1243 can be used any place a string (char *) is required:
1244 
1245     char * s = Perl_form("%d.%d",major,minor);
1246 
1247 Uses a single private buffer so if you want to format several strings you
1248 must explicitly copy the earlier strings away (and free the copies when you
1249 are done).
1250 
1251 =cut
1252 */
1253 
1254 char *
1255 Perl_form(pTHX_ const char* pat, ...)
1256 {
1257     char *retval;
1258     va_list args;
1259     PERL_ARGS_ASSERT_FORM;
1260     va_start(args, pat);
1261     retval = vform(pat, &args);
1262     va_end(args);
1263     return retval;
1264 }
1265 
1266 char *
1267 Perl_vform(pTHX_ const char *pat, va_list *args)
1268 {
1269     SV * const sv = mess_alloc();
1270     PERL_ARGS_ASSERT_VFORM;
1271     sv_vsetpvfn(sv, pat, strlen(pat), args, NULL, 0, NULL);
1272     return SvPVX(sv);
1273 }
1274 
1275 /*
1276 =for apidoc Am|SV *|mess|const char *pat|...
1277 
1278 Take a sprintf-style format pattern and argument list.  These are used to
1279 generate a string message.  If the message does not end with a newline,
1280 then it will be extended with some indication of the current location
1281 in the code, as described for L</mess_sv>.
1282 
1283 Normally, the resulting message is returned in a new mortal SV.
1284 During global destruction a single SV may be shared between uses of
1285 this function.
1286 
1287 =cut
1288 */
1289 
1290 #if defined(PERL_IMPLICIT_CONTEXT)
1291 SV *
1292 Perl_mess_nocontext(const char *pat, ...)
1293 {
1294     dTHX;
1295     SV *retval;
1296     va_list args;
1297     PERL_ARGS_ASSERT_MESS_NOCONTEXT;
1298     va_start(args, pat);
1299     retval = vmess(pat, &args);
1300     va_end(args);
1301     return retval;
1302 }
1303 #endif /* PERL_IMPLICIT_CONTEXT */
1304 
1305 SV *
1306 Perl_mess(pTHX_ const char *pat, ...)
1307 {
1308     SV *retval;
1309     va_list args;
1310     PERL_ARGS_ASSERT_MESS;
1311     va_start(args, pat);
1312     retval = vmess(pat, &args);
1313     va_end(args);
1314     return retval;
1315 }
1316 
1317 const COP*
1318 Perl_closest_cop(pTHX_ const COP *cop, const OP *o, const OP *curop,
1319 		       bool opnext)
1320 {
1321     /* Look for curop starting from o.  cop is the last COP we've seen. */
1322     /* opnext means that curop is actually the ->op_next of the op we are
1323        seeking. */
1324 
1325     PERL_ARGS_ASSERT_CLOSEST_COP;
1326 
1327     if (!o || !curop || (
1328 	opnext ? o->op_next == curop && o->op_type != OP_SCOPE : o == curop
1329     ))
1330 	return cop;
1331 
1332     if (o->op_flags & OPf_KIDS) {
1333 	const OP *kid;
1334 	for (kid = cUNOPo->op_first; kid; kid = OpSIBLING(kid)) {
1335 	    const COP *new_cop;
1336 
1337 	    /* If the OP_NEXTSTATE has been optimised away we can still use it
1338 	     * the get the file and line number. */
1339 
1340 	    if (kid->op_type == OP_NULL && kid->op_targ == OP_NEXTSTATE)
1341 		cop = (const COP *)kid;
1342 
1343 	    /* Keep searching, and return when we've found something. */
1344 
1345 	    new_cop = closest_cop(cop, kid, curop, opnext);
1346 	    if (new_cop)
1347 		return new_cop;
1348 	}
1349     }
1350 
1351     /* Nothing found. */
1352 
1353     return NULL;
1354 }
1355 
1356 /*
1357 =for apidoc Am|SV *|mess_sv|SV *basemsg|bool consume
1358 
1359 Expands a message, intended for the user, to include an indication of
1360 the current location in the code, if the message does not already appear
1361 to be complete.
1362 
1363 C<basemsg> is the initial message or object.  If it is a reference, it
1364 will be used as-is and will be the result of this function.  Otherwise it
1365 is used as a string, and if it already ends with a newline, it is taken
1366 to be complete, and the result of this function will be the same string.
1367 If the message does not end with a newline, then a segment such as C<at
1368 foo.pl line 37> will be appended, and possibly other clauses indicating
1369 the current state of execution.  The resulting message will end with a
1370 dot and a newline.
1371 
1372 Normally, the resulting message is returned in a new mortal SV.
1373 During global destruction a single SV may be shared between uses of this
1374 function.  If C<consume> is true, then the function is permitted (but not
1375 required) to modify and return C<basemsg> instead of allocating a new SV.
1376 
1377 =cut
1378 */
1379 
1380 SV *
1381 Perl_mess_sv(pTHX_ SV *basemsg, bool consume)
1382 {
1383     SV *sv;
1384 
1385 #if defined(USE_C_BACKTRACE) && defined(USE_C_BACKTRACE_ON_ERROR)
1386     {
1387         char *ws;
1388         UV wi;
1389         /* The PERL_C_BACKTRACE_ON_WARN must be an integer of one or more. */
1390         if ((ws = PerlEnv_getenv("PERL_C_BACKTRACE_ON_ERROR"))
1391             && grok_atoUV(ws, &wi, NULL)
1392             && wi <= PERL_INT_MAX
1393         ) {
1394             Perl_dump_c_backtrace(aTHX_ Perl_debug_log, (int)wi, 1);
1395         }
1396     }
1397 #endif
1398 
1399     PERL_ARGS_ASSERT_MESS_SV;
1400 
1401     if (SvROK(basemsg)) {
1402 	if (consume) {
1403 	    sv = basemsg;
1404 	}
1405 	else {
1406 	    sv = mess_alloc();
1407 	    sv_setsv(sv, basemsg);
1408 	}
1409 	return sv;
1410     }
1411 
1412     if (SvPOK(basemsg) && consume) {
1413 	sv = basemsg;
1414     }
1415     else {
1416 	sv = mess_alloc();
1417 	sv_copypv(sv, basemsg);
1418     }
1419 
1420     if (!SvCUR(sv) || *(SvEND(sv) - 1) != '\n') {
1421 	/*
1422 	 * Try and find the file and line for PL_op.  This will usually be
1423 	 * PL_curcop, but it might be a cop that has been optimised away.  We
1424 	 * can try to find such a cop by searching through the optree starting
1425 	 * from the sibling of PL_curcop.
1426 	 */
1427 
1428         if (PL_curcop) {
1429             const COP *cop =
1430                 closest_cop(PL_curcop, OpSIBLING(PL_curcop), PL_op, FALSE);
1431             if (!cop)
1432                 cop = PL_curcop;
1433 
1434             if (CopLINE(cop))
1435                 Perl_sv_catpvf(aTHX_ sv, " at %s line %" IVdf,
1436                                 OutCopFILE(cop), (IV)CopLINE(cop));
1437         }
1438 
1439 	/* Seems that GvIO() can be untrustworthy during global destruction. */
1440 	if (GvIO(PL_last_in_gv) && (SvTYPE(GvIOp(PL_last_in_gv)) == SVt_PVIO)
1441 		&& IoLINES(GvIOp(PL_last_in_gv)))
1442 	{
1443 	    STRLEN l;
1444 	    const bool line_mode = (RsSIMPLE(PL_rs) &&
1445 				   *SvPV_const(PL_rs,l) == '\n' && l == 1);
1446 	    Perl_sv_catpvf(aTHX_ sv, ", <%" SVf "> %s %" IVdf,
1447 			   SVfARG(PL_last_in_gv == PL_argvgv
1448                                  ? &PL_sv_no
1449                                  : sv_2mortal(newSVhek(GvNAME_HEK(PL_last_in_gv)))),
1450 			   line_mode ? "line" : "chunk",
1451 			   (IV)IoLINES(GvIOp(PL_last_in_gv)));
1452 	}
1453 	if (PL_phase == PERL_PHASE_DESTRUCT)
1454 	    sv_catpvs(sv, " during global destruction");
1455 	sv_catpvs(sv, ".\n");
1456     }
1457     return sv;
1458 }
1459 
1460 /*
1461 =for apidoc Am|SV *|vmess|const char *pat|va_list *args
1462 
1463 C<pat> and C<args> are a sprintf-style format pattern and encapsulated
1464 argument list, respectively.  These are used to generate a string message.  If
1465 the
1466 message does not end with a newline, then it will be extended with
1467 some indication of the current location in the code, as described for
1468 L</mess_sv>.
1469 
1470 Normally, the resulting message is returned in a new mortal SV.
1471 During global destruction a single SV may be shared between uses of
1472 this function.
1473 
1474 =cut
1475 */
1476 
1477 SV *
1478 Perl_vmess(pTHX_ const char *pat, va_list *args)
1479 {
1480     SV * const sv = mess_alloc();
1481 
1482     PERL_ARGS_ASSERT_VMESS;
1483 
1484     sv_vsetpvfn(sv, pat, strlen(pat), args, NULL, 0, NULL);
1485     return mess_sv(sv, 1);
1486 }
1487 
1488 void
1489 Perl_write_to_stderr(pTHX_ SV* msv)
1490 {
1491     IO *io;
1492     MAGIC *mg;
1493 
1494     PERL_ARGS_ASSERT_WRITE_TO_STDERR;
1495 
1496     if (PL_stderrgv && SvREFCNT(PL_stderrgv)
1497 	&& (io = GvIO(PL_stderrgv))
1498 	&& (mg = SvTIED_mg((const SV *)io, PERL_MAGIC_tiedscalar)))
1499 	Perl_magic_methcall(aTHX_ MUTABLE_SV(io), mg, SV_CONST(PRINT),
1500 			    G_SCALAR | G_DISCARD | G_WRITING_TO_STDERR, 1, msv);
1501     else {
1502 	PerlIO * const serr = Perl_error_log;
1503 
1504 	do_print(msv, serr);
1505 	(void)PerlIO_flush(serr);
1506     }
1507 }
1508 
1509 /*
1510 =head1 Warning and Dieing
1511 */
1512 
1513 /* Common code used in dieing and warning */
1514 
1515 STATIC SV *
1516 S_with_queued_errors(pTHX_ SV *ex)
1517 {
1518     PERL_ARGS_ASSERT_WITH_QUEUED_ERRORS;
1519     if (PL_errors && SvCUR(PL_errors) && !SvROK(ex)) {
1520 	sv_catsv(PL_errors, ex);
1521 	ex = sv_mortalcopy(PL_errors);
1522 	SvCUR_set(PL_errors, 0);
1523     }
1524     return ex;
1525 }
1526 
1527 STATIC bool
1528 S_invoke_exception_hook(pTHX_ SV *ex, bool warn)
1529 {
1530     HV *stash;
1531     GV *gv;
1532     CV *cv;
1533     SV **const hook = warn ? &PL_warnhook : &PL_diehook;
1534     /* sv_2cv might call Perl_croak() or Perl_warner() */
1535     SV * const oldhook = *hook;
1536 
1537     if (!oldhook)
1538 	return FALSE;
1539 
1540     ENTER;
1541     SAVESPTR(*hook);
1542     *hook = NULL;
1543     cv = sv_2cv(oldhook, &stash, &gv, 0);
1544     LEAVE;
1545     if (cv && !CvDEPTH(cv) && (CvROOT(cv) || CvXSUB(cv))) {
1546 	dSP;
1547 	SV *exarg;
1548 
1549 	ENTER;
1550 	save_re_context();
1551 	if (warn) {
1552 	    SAVESPTR(*hook);
1553 	    *hook = NULL;
1554 	}
1555 	exarg = newSVsv(ex);
1556 	SvREADONLY_on(exarg);
1557 	SAVEFREESV(exarg);
1558 
1559 	PUSHSTACKi(warn ? PERLSI_WARNHOOK : PERLSI_DIEHOOK);
1560 	PUSHMARK(SP);
1561 	XPUSHs(exarg);
1562 	PUTBACK;
1563 	call_sv(MUTABLE_SV(cv), G_DISCARD);
1564 	POPSTACK;
1565 	LEAVE;
1566 	return TRUE;
1567     }
1568     return FALSE;
1569 }
1570 
1571 /*
1572 =for apidoc Am|OP *|die_sv|SV *baseex
1573 
1574 Behaves the same as L</croak_sv>, except for the return type.
1575 It should be used only where the C<OP *> return type is required.
1576 The function never actually returns.
1577 
1578 =cut
1579 */
1580 
1581 #ifdef _MSC_VER
1582 #  pragma warning( push )
1583 #  pragma warning( disable : 4646 ) /* warning C4646: function declared with
1584     __declspec(noreturn) has non-void return type */
1585 #  pragma warning( disable : 4645 ) /* warning C4645: function declared with
1586 __declspec(noreturn) has a return statement */
1587 #endif
1588 OP *
1589 Perl_die_sv(pTHX_ SV *baseex)
1590 {
1591     PERL_ARGS_ASSERT_DIE_SV;
1592     croak_sv(baseex);
1593     /* NOTREACHED */
1594     NORETURN_FUNCTION_END;
1595 }
1596 #ifdef _MSC_VER
1597 #  pragma warning( pop )
1598 #endif
1599 
1600 /*
1601 =for apidoc Am|OP *|die|const char *pat|...
1602 
1603 Behaves the same as L</croak>, except for the return type.
1604 It should be used only where the C<OP *> return type is required.
1605 The function never actually returns.
1606 
1607 =cut
1608 */
1609 
1610 #if defined(PERL_IMPLICIT_CONTEXT)
1611 #ifdef _MSC_VER
1612 #  pragma warning( push )
1613 #  pragma warning( disable : 4646 ) /* warning C4646: function declared with
1614     __declspec(noreturn) has non-void return type */
1615 #  pragma warning( disable : 4645 ) /* warning C4645: function declared with
1616 __declspec(noreturn) has a return statement */
1617 #endif
1618 OP *
1619 Perl_die_nocontext(const char* pat, ...)
1620 {
1621     dTHX;
1622     va_list args;
1623     va_start(args, pat);
1624     vcroak(pat, &args);
1625     NOT_REACHED; /* NOTREACHED */
1626     va_end(args);
1627     NORETURN_FUNCTION_END;
1628 }
1629 #ifdef _MSC_VER
1630 #  pragma warning( pop )
1631 #endif
1632 #endif /* PERL_IMPLICIT_CONTEXT */
1633 
1634 #ifdef _MSC_VER
1635 #  pragma warning( push )
1636 #  pragma warning( disable : 4646 ) /* warning C4646: function declared with
1637     __declspec(noreturn) has non-void return type */
1638 #  pragma warning( disable : 4645 ) /* warning C4645: function declared with
1639 __declspec(noreturn) has a return statement */
1640 #endif
1641 OP *
1642 Perl_die(pTHX_ const char* pat, ...)
1643 {
1644     va_list args;
1645     va_start(args, pat);
1646     vcroak(pat, &args);
1647     NOT_REACHED; /* NOTREACHED */
1648     va_end(args);
1649     NORETURN_FUNCTION_END;
1650 }
1651 #ifdef _MSC_VER
1652 #  pragma warning( pop )
1653 #endif
1654 
1655 /*
1656 =for apidoc Am|void|croak_sv|SV *baseex
1657 
1658 This is an XS interface to Perl's C<die> function.
1659 
1660 C<baseex> is the error message or object.  If it is a reference, it
1661 will be used as-is.  Otherwise it is used as a string, and if it does
1662 not end with a newline then it will be extended with some indication of
1663 the current location in the code, as described for L</mess_sv>.
1664 
1665 The error message or object will be used as an exception, by default
1666 returning control to the nearest enclosing C<eval>, but subject to
1667 modification by a C<$SIG{__DIE__}> handler.  In any case, the C<croak_sv>
1668 function never returns normally.
1669 
1670 To die with a simple string message, the L</croak> function may be
1671 more convenient.
1672 
1673 =cut
1674 */
1675 
1676 void
1677 Perl_croak_sv(pTHX_ SV *baseex)
1678 {
1679     SV *ex = with_queued_errors(mess_sv(baseex, 0));
1680     PERL_ARGS_ASSERT_CROAK_SV;
1681     invoke_exception_hook(ex, FALSE);
1682     die_unwind(ex);
1683 }
1684 
1685 /*
1686 =for apidoc Am|void|vcroak|const char *pat|va_list *args
1687 
1688 This is an XS interface to Perl's C<die> function.
1689 
1690 C<pat> and C<args> are a sprintf-style format pattern and encapsulated
1691 argument list.  These are used to generate a string message.  If the
1692 message does not end with a newline, then it will be extended with
1693 some indication of the current location in the code, as described for
1694 L</mess_sv>.
1695 
1696 The error message will be used as an exception, by default
1697 returning control to the nearest enclosing C<eval>, but subject to
1698 modification by a C<$SIG{__DIE__}> handler.  In any case, the C<croak>
1699 function never returns normally.
1700 
1701 For historical reasons, if C<pat> is null then the contents of C<ERRSV>
1702 (C<$@>) will be used as an error message or object instead of building an
1703 error message from arguments.  If you want to throw a non-string object,
1704 or build an error message in an SV yourself, it is preferable to use
1705 the L</croak_sv> function, which does not involve clobbering C<ERRSV>.
1706 
1707 =cut
1708 */
1709 
1710 void
1711 Perl_vcroak(pTHX_ const char* pat, va_list *args)
1712 {
1713     SV *ex = with_queued_errors(pat ? vmess(pat, args) : mess_sv(ERRSV, 0));
1714     invoke_exception_hook(ex, FALSE);
1715     die_unwind(ex);
1716 }
1717 
1718 /*
1719 =for apidoc Am|void|croak|const char *pat|...
1720 
1721 This is an XS interface to Perl's C<die> function.
1722 
1723 Take a sprintf-style format pattern and argument list.  These are used to
1724 generate a string message.  If the message does not end with a newline,
1725 then it will be extended with some indication of the current location
1726 in the code, as described for L</mess_sv>.
1727 
1728 The error message will be used as an exception, by default
1729 returning control to the nearest enclosing C<eval>, but subject to
1730 modification by a C<$SIG{__DIE__}> handler.  In any case, the C<croak>
1731 function never returns normally.
1732 
1733 For historical reasons, if C<pat> is null then the contents of C<ERRSV>
1734 (C<$@>) will be used as an error message or object instead of building an
1735 error message from arguments.  If you want to throw a non-string object,
1736 or build an error message in an SV yourself, it is preferable to use
1737 the L</croak_sv> function, which does not involve clobbering C<ERRSV>.
1738 
1739 =cut
1740 */
1741 
1742 #if defined(PERL_IMPLICIT_CONTEXT)
1743 void
1744 Perl_croak_nocontext(const char *pat, ...)
1745 {
1746     dTHX;
1747     va_list args;
1748     va_start(args, pat);
1749     vcroak(pat, &args);
1750     NOT_REACHED; /* NOTREACHED */
1751     va_end(args);
1752 }
1753 #endif /* PERL_IMPLICIT_CONTEXT */
1754 
1755 void
1756 Perl_croak(pTHX_ const char *pat, ...)
1757 {
1758     va_list args;
1759     va_start(args, pat);
1760     vcroak(pat, &args);
1761     NOT_REACHED; /* NOTREACHED */
1762     va_end(args);
1763 }
1764 
1765 /*
1766 =for apidoc Am|void|croak_no_modify
1767 
1768 Exactly equivalent to C<Perl_croak(aTHX_ "%s", PL_no_modify)>, but generates
1769 terser object code than using C<Perl_croak>.  Less code used on exception code
1770 paths reduces CPU cache pressure.
1771 
1772 =cut
1773 */
1774 
1775 void
1776 Perl_croak_no_modify(void)
1777 {
1778     Perl_croak_nocontext( "%s", PL_no_modify);
1779 }
1780 
1781 /* does not return, used in util.c perlio.c and win32.c
1782    This is typically called when malloc returns NULL.
1783 */
1784 void
1785 Perl_croak_no_mem(void)
1786 {
1787     dTHX;
1788 
1789     int fd = PerlIO_fileno(Perl_error_log);
1790     if (fd < 0)
1791         SETERRNO(EBADF,RMS_IFI);
1792     else {
1793         /* Can't use PerlIO to write as it allocates memory */
1794         PERL_UNUSED_RESULT(PerlLIO_write(fd, PL_no_mem, sizeof(PL_no_mem)-1));
1795     }
1796     my_exit(1);
1797 }
1798 
1799 /* does not return, used only in POPSTACK */
1800 void
1801 Perl_croak_popstack(void)
1802 {
1803     dTHX;
1804     PerlIO_printf(Perl_error_log, "panic: POPSTACK\n");
1805     my_exit(1);
1806 }
1807 
1808 /*
1809 =for apidoc Am|void|warn_sv|SV *baseex
1810 
1811 This is an XS interface to Perl's C<warn> function.
1812 
1813 C<baseex> is the error message or object.  If it is a reference, it
1814 will be used as-is.  Otherwise it is used as a string, and if it does
1815 not end with a newline then it will be extended with some indication of
1816 the current location in the code, as described for L</mess_sv>.
1817 
1818 The error message or object will by default be written to standard error,
1819 but this is subject to modification by a C<$SIG{__WARN__}> handler.
1820 
1821 To warn with a simple string message, the L</warn> function may be
1822 more convenient.
1823 
1824 =cut
1825 */
1826 
1827 void
1828 Perl_warn_sv(pTHX_ SV *baseex)
1829 {
1830     SV *ex = mess_sv(baseex, 0);
1831     PERL_ARGS_ASSERT_WARN_SV;
1832     if (!invoke_exception_hook(ex, TRUE))
1833 	write_to_stderr(ex);
1834 }
1835 
1836 /*
1837 =for apidoc Am|void|vwarn|const char *pat|va_list *args
1838 
1839 This is an XS interface to Perl's C<warn> function.
1840 
1841 C<pat> and C<args> are a sprintf-style format pattern and encapsulated
1842 argument list.  These are used to generate a string message.  If the
1843 message does not end with a newline, then it will be extended with
1844 some indication of the current location in the code, as described for
1845 L</mess_sv>.
1846 
1847 The error message or object will by default be written to standard error,
1848 but this is subject to modification by a C<$SIG{__WARN__}> handler.
1849 
1850 Unlike with L</vcroak>, C<pat> is not permitted to be null.
1851 
1852 =cut
1853 */
1854 
1855 void
1856 Perl_vwarn(pTHX_ const char* pat, va_list *args)
1857 {
1858     SV *ex = vmess(pat, args);
1859     PERL_ARGS_ASSERT_VWARN;
1860     if (!invoke_exception_hook(ex, TRUE))
1861 	write_to_stderr(ex);
1862 }
1863 
1864 /*
1865 =for apidoc Am|void|warn|const char *pat|...
1866 
1867 This is an XS interface to Perl's C<warn> function.
1868 
1869 Take a sprintf-style format pattern and argument list.  These are used to
1870 generate a string message.  If the message does not end with a newline,
1871 then it will be extended with some indication of the current location
1872 in the code, as described for L</mess_sv>.
1873 
1874 The error message or object will by default be written to standard error,
1875 but this is subject to modification by a C<$SIG{__WARN__}> handler.
1876 
1877 Unlike with L</croak>, C<pat> is not permitted to be null.
1878 
1879 =cut
1880 */
1881 
1882 #if defined(PERL_IMPLICIT_CONTEXT)
1883 void
1884 Perl_warn_nocontext(const char *pat, ...)
1885 {
1886     dTHX;
1887     va_list args;
1888     PERL_ARGS_ASSERT_WARN_NOCONTEXT;
1889     va_start(args, pat);
1890     vwarn(pat, &args);
1891     va_end(args);
1892 }
1893 #endif /* PERL_IMPLICIT_CONTEXT */
1894 
1895 void
1896 Perl_warn(pTHX_ const char *pat, ...)
1897 {
1898     va_list args;
1899     PERL_ARGS_ASSERT_WARN;
1900     va_start(args, pat);
1901     vwarn(pat, &args);
1902     va_end(args);
1903 }
1904 
1905 #if defined(PERL_IMPLICIT_CONTEXT)
1906 void
1907 Perl_warner_nocontext(U32 err, const char *pat, ...)
1908 {
1909     dTHX;
1910     va_list args;
1911     PERL_ARGS_ASSERT_WARNER_NOCONTEXT;
1912     va_start(args, pat);
1913     vwarner(err, pat, &args);
1914     va_end(args);
1915 }
1916 #endif /* PERL_IMPLICIT_CONTEXT */
1917 
1918 void
1919 Perl_ck_warner_d(pTHX_ U32 err, const char* pat, ...)
1920 {
1921     PERL_ARGS_ASSERT_CK_WARNER_D;
1922 
1923     if (Perl_ckwarn_d(aTHX_ err)) {
1924 	va_list args;
1925 	va_start(args, pat);
1926 	vwarner(err, pat, &args);
1927 	va_end(args);
1928     }
1929 }
1930 
1931 void
1932 Perl_ck_warner(pTHX_ U32 err, const char* pat, ...)
1933 {
1934     PERL_ARGS_ASSERT_CK_WARNER;
1935 
1936     if (Perl_ckwarn(aTHX_ err)) {
1937 	va_list args;
1938 	va_start(args, pat);
1939 	vwarner(err, pat, &args);
1940 	va_end(args);
1941     }
1942 }
1943 
1944 void
1945 Perl_warner(pTHX_ U32  err, const char* pat,...)
1946 {
1947     va_list args;
1948     PERL_ARGS_ASSERT_WARNER;
1949     va_start(args, pat);
1950     vwarner(err, pat, &args);
1951     va_end(args);
1952 }
1953 
1954 void
1955 Perl_vwarner(pTHX_ U32  err, const char* pat, va_list* args)
1956 {
1957     dVAR;
1958     PERL_ARGS_ASSERT_VWARNER;
1959     if (
1960         (PL_warnhook == PERL_WARNHOOK_FATAL || ckDEAD(err)) &&
1961         !(PL_in_eval & EVAL_KEEPERR)
1962     ) {
1963 	SV * const msv = vmess(pat, args);
1964 
1965 	if (PL_parser && PL_parser->error_count) {
1966 	    qerror(msv);
1967 	}
1968 	else {
1969 	    invoke_exception_hook(msv, FALSE);
1970 	    die_unwind(msv);
1971 	}
1972     }
1973     else {
1974 	Perl_vwarn(aTHX_ pat, args);
1975     }
1976 }
1977 
1978 /* implements the ckWARN? macros */
1979 
1980 bool
1981 Perl_ckwarn(pTHX_ U32 w)
1982 {
1983     /* If lexical warnings have not been set, use $^W.  */
1984     if (isLEXWARN_off)
1985 	return PL_dowarn & G_WARN_ON;
1986 
1987     return ckwarn_common(w);
1988 }
1989 
1990 /* implements the ckWARN?_d macro */
1991 
1992 bool
1993 Perl_ckwarn_d(pTHX_ U32 w)
1994 {
1995     /* If lexical warnings have not been set then default classes warn.  */
1996     if (isLEXWARN_off)
1997 	return TRUE;
1998 
1999     return ckwarn_common(w);
2000 }
2001 
2002 static bool
2003 S_ckwarn_common(pTHX_ U32 w)
2004 {
2005     if (PL_curcop->cop_warnings == pWARN_ALL)
2006 	return TRUE;
2007 
2008     if (PL_curcop->cop_warnings == pWARN_NONE)
2009 	return FALSE;
2010 
2011     /* Check the assumption that at least the first slot is non-zero.  */
2012     assert(unpackWARN1(w));
2013 
2014     /* Check the assumption that it is valid to stop as soon as a zero slot is
2015        seen.  */
2016     if (!unpackWARN2(w)) {
2017 	assert(!unpackWARN3(w));
2018 	assert(!unpackWARN4(w));
2019     } else if (!unpackWARN3(w)) {
2020 	assert(!unpackWARN4(w));
2021     }
2022 
2023     /* Right, dealt with all the special cases, which are implemented as non-
2024        pointers, so there is a pointer to a real warnings mask.  */
2025     do {
2026 	if (isWARN_on(PL_curcop->cop_warnings, unpackWARN1(w)))
2027 	    return TRUE;
2028     } while (w >>= WARNshift);
2029 
2030     return FALSE;
2031 }
2032 
2033 /* Set buffer=NULL to get a new one.  */
2034 STRLEN *
2035 Perl_new_warnings_bitfield(pTHX_ STRLEN *buffer, const char *const bits,
2036 			   STRLEN size) {
2037     const MEM_SIZE len_wanted =
2038 	sizeof(STRLEN) + (size > WARNsize ? size : WARNsize);
2039     PERL_UNUSED_CONTEXT;
2040     PERL_ARGS_ASSERT_NEW_WARNINGS_BITFIELD;
2041 
2042     buffer = (STRLEN*)
2043 	(specialWARN(buffer) ?
2044 	 PerlMemShared_malloc(len_wanted) :
2045 	 PerlMemShared_realloc(buffer, len_wanted));
2046     buffer[0] = size;
2047     Copy(bits, (buffer + 1), size, char);
2048     if (size < WARNsize)
2049 	Zero((char *)(buffer + 1) + size, WARNsize - size, char);
2050     return buffer;
2051 }
2052 
2053 /* since we've already done strlen() for both nam and val
2054  * we can use that info to make things faster than
2055  * sprintf(s, "%s=%s", nam, val)
2056  */
2057 #define my_setenv_format(s, nam, nlen, val, vlen) \
2058    Copy(nam, s, nlen, char); \
2059    *(s+nlen) = '='; \
2060    Copy(val, s+(nlen+1), vlen, char); \
2061    *(s+(nlen+1+vlen)) = '\0'
2062 
2063 #ifdef USE_ENVIRON_ARRAY
2064 
2065 /* small wrapper for use by Perl_my_setenv that mallocs, or reallocs if
2066  * 'current' is non-null, with up to three sizes that are added together.
2067  * It handles integer overflow.
2068  */
2069 static char *
2070 S_env_alloc(void *current, Size_t l1, Size_t l2, Size_t l3, Size_t size)
2071 {
2072     void *p;
2073     Size_t sl, l = l1 + l2;
2074 
2075     if (l < l2)
2076         goto panic;
2077     l += l3;
2078     if (l < l3)
2079         goto panic;
2080     sl = l * size;
2081     if (sl < l)
2082         goto panic;
2083 
2084     p = current
2085             ? safesysrealloc(current, sl)
2086             : safesysmalloc(sl);
2087     if (p)
2088         return (char*)p;
2089 
2090   panic:
2091     croak_memory_wrap();
2092 }
2093 
2094 
2095 /* VMS' my_setenv() is in vms.c */
2096 #if !defined(WIN32) && !defined(NETWARE)
2097 
2098 void
2099 Perl_my_setenv(pTHX_ const char *nam, const char *val)
2100 {
2101   dVAR;
2102 #ifdef __amigaos4__
2103   amigaos4_obtain_environ(__FUNCTION__);
2104 #endif
2105 #ifdef USE_ITHREADS
2106   /* only parent thread can modify process environment */
2107   if (PL_curinterp == aTHX)
2108 #endif
2109   {
2110 #ifndef PERL_USE_SAFE_PUTENV
2111     if (!PL_use_safe_putenv) {
2112         /* most putenv()s leak, so we manipulate environ directly */
2113         UV i;
2114         Size_t vlen, nlen = strlen(nam);
2115 
2116         /* where does it go? */
2117         for (i = 0; environ[i]; i++) {
2118             if (strnEQ(environ[i], nam, nlen) && environ[i][nlen] == '=')
2119                 break;
2120         }
2121 
2122         if (environ == PL_origenviron) {   /* need we copy environment? */
2123             UV j, max;
2124             char **tmpenv;
2125 
2126             max = i;
2127             while (environ[max])
2128                 max++;
2129             /* XXX shouldn't that be max+1 rather than max+2 ??? - DAPM */
2130             tmpenv = (char**)S_env_alloc(NULL, max, 2, 0, sizeof(char*));
2131             for (j=0; j<max; j++) {         /* copy environment */
2132                 const Size_t len = strlen(environ[j]);
2133                 tmpenv[j] = S_env_alloc(NULL, len, 1, 0, 1);
2134                 Copy(environ[j], tmpenv[j], len+1, char);
2135             }
2136             tmpenv[max] = NULL;
2137             environ = tmpenv;               /* tell exec where it is now */
2138         }
2139         if (!val) {
2140             safesysfree(environ[i]);
2141             while (environ[i]) {
2142                 environ[i] = environ[i+1];
2143                 i++;
2144             }
2145 #ifdef __amigaos4__
2146             goto my_setenv_out;
2147 #else
2148             return;
2149 #endif
2150         }
2151         if (!environ[i]) {                 /* does not exist yet */
2152             environ = (char**)S_env_alloc(environ, i, 2, 0, sizeof(char*));
2153             environ[i+1] = NULL;    /* make sure it's null terminated */
2154         }
2155         else
2156             safesysfree(environ[i]);
2157 
2158         vlen = strlen(val);
2159 
2160         environ[i] = S_env_alloc(NULL, nlen, vlen, 2, 1);
2161         /* all that work just for this */
2162         my_setenv_format(environ[i], nam, nlen, val, vlen);
2163     } else {
2164 # endif
2165     /* This next branch should only be called #if defined(HAS_SETENV), but
2166        Configure doesn't test for that yet.  For Solaris, setenv() and unsetenv()
2167        were introduced in Solaris 9, so testing for HAS UNSETENV is sufficient.
2168     */
2169 #   if defined(__CYGWIN__)|| defined(__SYMBIAN32__) || defined(__riscos__) || (defined(__sun) && defined(HAS_UNSETENV)) || defined(PERL_DARWIN)
2170 #       if defined(HAS_UNSETENV)
2171         if (val == NULL) {
2172             (void)unsetenv(nam);
2173         } else {
2174             (void)setenv(nam, val, 1);
2175         }
2176 #       else /* ! HAS_UNSETENV */
2177         (void)setenv(nam, val, 1);
2178 #       endif /* HAS_UNSETENV */
2179 #   elif defined(HAS_UNSETENV)
2180         if (val == NULL) {
2181             if (environ) /* old glibc can crash with null environ */
2182                 (void)unsetenv(nam);
2183         } else {
2184 	    const Size_t nlen = strlen(nam);
2185 	    const Size_t vlen = strlen(val);
2186 	    char * const new_env = S_env_alloc(NULL, nlen, vlen, 2, 1);
2187             my_setenv_format(new_env, nam, nlen, val, vlen);
2188             (void)putenv(new_env);
2189         }
2190 #   else /* ! HAS_UNSETENV */
2191         char *new_env;
2192 	const Size_t nlen = strlen(nam);
2193 	Size_t vlen;
2194         if (!val) {
2195 	   val = "";
2196         }
2197         vlen = strlen(val);
2198         new_env = S_env_alloc(NULL, nlen, vlen, 2, 1);
2199         /* all that work just for this */
2200         my_setenv_format(new_env, nam, nlen, val, vlen);
2201         (void)putenv(new_env);
2202 #   endif /* __CYGWIN__ */
2203 #ifndef PERL_USE_SAFE_PUTENV
2204     }
2205 #endif
2206   }
2207 #ifdef __amigaos4__
2208 my_setenv_out:
2209   amigaos4_release_environ(__FUNCTION__);
2210 #endif
2211 }
2212 
2213 #else /* WIN32 || NETWARE */
2214 
2215 void
2216 Perl_my_setenv(pTHX_ const char *nam, const char *val)
2217 {
2218     dVAR;
2219     char *envstr;
2220     const Size_t nlen = strlen(nam);
2221     Size_t vlen;
2222 
2223     if (!val) {
2224        val = "";
2225     }
2226     vlen = strlen(val);
2227     envstr = S_env_alloc(NULL, nlen, vlen, 2, 1);
2228     my_setenv_format(envstr, nam, nlen, val, vlen);
2229     (void)PerlEnv_putenv(envstr);
2230     Safefree(envstr);
2231 }
2232 
2233 #endif /* WIN32 || NETWARE */
2234 
2235 #endif /* !VMS */
2236 
2237 #ifdef UNLINK_ALL_VERSIONS
2238 I32
2239 Perl_unlnk(pTHX_ const char *f)	/* unlink all versions of a file */
2240 {
2241     I32 retries = 0;
2242 
2243     PERL_ARGS_ASSERT_UNLNK;
2244 
2245     while (PerlLIO_unlink(f) >= 0)
2246 	retries++;
2247     return retries ? 0 : -1;
2248 }
2249 #endif
2250 
2251 PerlIO *
2252 Perl_my_popen_list(pTHX_ const char *mode, int n, SV **args)
2253 {
2254 #if (!defined(DOSISH) || defined(HAS_FORK)) && !defined(OS2) && !defined(VMS) && !defined(NETWARE) && !defined(__LIBCATAMOUNT__) && !defined(__amigaos4__)
2255     int p[2];
2256     I32 This, that;
2257     Pid_t pid;
2258     SV *sv;
2259     I32 did_pipes = 0;
2260     int pp[2];
2261 
2262     PERL_ARGS_ASSERT_MY_POPEN_LIST;
2263 
2264     PERL_FLUSHALL_FOR_CHILD;
2265     This = (*mode == 'w');
2266     that = !This;
2267     if (TAINTING_get) {
2268 	taint_env();
2269 	taint_proper("Insecure %s%s", "EXEC");
2270     }
2271     if (PerlProc_pipe_cloexec(p) < 0)
2272 	return NULL;
2273     /* Try for another pipe pair for error return */
2274     if (PerlProc_pipe_cloexec(pp) >= 0)
2275 	did_pipes = 1;
2276     while ((pid = PerlProc_fork()) < 0) {
2277 	if (errno != EAGAIN) {
2278 	    PerlLIO_close(p[This]);
2279 	    PerlLIO_close(p[that]);
2280 	    if (did_pipes) {
2281 		PerlLIO_close(pp[0]);
2282 		PerlLIO_close(pp[1]);
2283 	    }
2284 	    return NULL;
2285 	}
2286 	Perl_ck_warner(aTHX_ packWARN(WARN_PIPE), "Can't fork, trying again in 5 seconds");
2287 	sleep(5);
2288     }
2289     if (pid == 0) {
2290 	/* Child */
2291 #undef THIS
2292 #undef THAT
2293 #define THIS that
2294 #define THAT This
2295 	/* Close parent's end of error status pipe (if any) */
2296 	if (did_pipes)
2297 	    PerlLIO_close(pp[0]);
2298 	/* Now dup our end of _the_ pipe to right position */
2299 	if (p[THIS] != (*mode == 'r')) {
2300 	    PerlLIO_dup2(p[THIS], *mode == 'r');
2301 	    PerlLIO_close(p[THIS]);
2302 	    if (p[THAT] != (*mode == 'r'))	/* if dup2() didn't close it */
2303 		PerlLIO_close(p[THAT]);	/* close parent's end of _the_ pipe */
2304 	}
2305 	else
2306 	    PerlLIO_close(p[THAT]);	/* close parent's end of _the_ pipe */
2307 #if !defined(HAS_FCNTL) || !defined(F_SETFD)
2308 	/* No automatic close - do it by hand */
2309 #  ifndef NOFILE
2310 #  define NOFILE 20
2311 #  endif
2312 	{
2313 	    int fd;
2314 
2315 	    for (fd = PL_maxsysfd + 1; fd < NOFILE; fd++) {
2316 		if (fd != pp[1])
2317 		    PerlLIO_close(fd);
2318 	    }
2319 	}
2320 #endif
2321 	do_aexec5(NULL, args-1, args-1+n, pp[1], did_pipes);
2322 	PerlProc__exit(1);
2323 #undef THIS
2324 #undef THAT
2325     }
2326     /* Parent */
2327     if (did_pipes)
2328 	PerlLIO_close(pp[1]);
2329     /* Keep the lower of the two fd numbers */
2330     if (p[that] < p[This]) {
2331 	PerlLIO_dup2_cloexec(p[This], p[that]);
2332 	PerlLIO_close(p[This]);
2333 	p[This] = p[that];
2334     }
2335     else
2336 	PerlLIO_close(p[that]);		/* close child's end of pipe */
2337 
2338     sv = *av_fetch(PL_fdpid,p[This],TRUE);
2339     SvUPGRADE(sv,SVt_IV);
2340     SvIV_set(sv, pid);
2341     PL_forkprocess = pid;
2342     /* If we managed to get status pipe check for exec fail */
2343     if (did_pipes && pid > 0) {
2344 	int errkid;
2345 	unsigned n = 0;
2346 
2347 	while (n < sizeof(int)) {
2348             const SSize_t n1 = PerlLIO_read(pp[0],
2349 			      (void*)(((char*)&errkid)+n),
2350 			      (sizeof(int)) - n);
2351 	    if (n1 <= 0)
2352 		break;
2353 	    n += n1;
2354 	}
2355 	PerlLIO_close(pp[0]);
2356 	did_pipes = 0;
2357 	if (n) {			/* Error */
2358 	    int pid2, status;
2359 	    PerlLIO_close(p[This]);
2360 	    if (n != sizeof(int))
2361 		Perl_croak(aTHX_ "panic: kid popen errno read, n=%u", n);
2362 	    do {
2363 		pid2 = wait4pid(pid, &status, 0);
2364 	    } while (pid2 == -1 && errno == EINTR);
2365 	    errno = errkid;		/* Propagate errno from kid */
2366 	    return NULL;
2367 	}
2368     }
2369     if (did_pipes)
2370 	 PerlLIO_close(pp[0]);
2371     return PerlIO_fdopen(p[This], mode);
2372 #else
2373 #  if defined(OS2)	/* Same, without fork()ing and all extra overhead... */
2374     return my_syspopen4(aTHX_ NULL, mode, n, args);
2375 #  elif defined(WIN32)
2376     return win32_popenlist(mode, n, args);
2377 #  else
2378     Perl_croak(aTHX_ "List form of piped open not implemented");
2379     return (PerlIO *) NULL;
2380 #  endif
2381 #endif
2382 }
2383 
2384     /* VMS' my_popen() is in VMS.c, same with OS/2 and AmigaOS 4. */
2385 #if (!defined(DOSISH) || defined(HAS_FORK)) && !defined(VMS) && !defined(__LIBCATAMOUNT__) && !defined(__amigaos4__)
2386 PerlIO *
2387 Perl_my_popen(pTHX_ const char *cmd, const char *mode)
2388 {
2389     int p[2];
2390     I32 This, that;
2391     Pid_t pid;
2392     SV *sv;
2393     const I32 doexec = !(*cmd == '-' && cmd[1] == '\0');
2394     I32 did_pipes = 0;
2395     int pp[2];
2396 
2397     PERL_ARGS_ASSERT_MY_POPEN;
2398 
2399     PERL_FLUSHALL_FOR_CHILD;
2400 #ifdef OS2
2401     if (doexec) {
2402 	return my_syspopen(aTHX_ cmd,mode);
2403     }
2404 #endif
2405     This = (*mode == 'w');
2406     that = !This;
2407     if (doexec && TAINTING_get) {
2408 	taint_env();
2409 	taint_proper("Insecure %s%s", "EXEC");
2410     }
2411     if (PerlProc_pipe_cloexec(p) < 0)
2412 	return NULL;
2413     if (doexec && PerlProc_pipe_cloexec(pp) >= 0)
2414 	did_pipes = 1;
2415     while ((pid = PerlProc_fork()) < 0) {
2416 	if (errno != EAGAIN) {
2417 	    PerlLIO_close(p[This]);
2418 	    PerlLIO_close(p[that]);
2419 	    if (did_pipes) {
2420 		PerlLIO_close(pp[0]);
2421 		PerlLIO_close(pp[1]);
2422 	    }
2423 	    if (!doexec)
2424 		Perl_croak(aTHX_ "Can't fork: %s", Strerror(errno));
2425 	    return NULL;
2426 	}
2427 	Perl_ck_warner(aTHX_ packWARN(WARN_PIPE), "Can't fork, trying again in 5 seconds");
2428 	sleep(5);
2429     }
2430     if (pid == 0) {
2431 
2432 #undef THIS
2433 #undef THAT
2434 #define THIS that
2435 #define THAT This
2436 	if (did_pipes)
2437 	    PerlLIO_close(pp[0]);
2438 	if (p[THIS] != (*mode == 'r')) {
2439 	    PerlLIO_dup2(p[THIS], *mode == 'r');
2440 	    PerlLIO_close(p[THIS]);
2441 	    if (p[THAT] != (*mode == 'r'))	/* if dup2() didn't close it */
2442 		PerlLIO_close(p[THAT]);
2443 	}
2444 	else
2445 	    PerlLIO_close(p[THAT]);
2446 #ifndef OS2
2447 	if (doexec) {
2448 #if !defined(HAS_FCNTL) || !defined(F_SETFD)
2449 #ifndef NOFILE
2450 #define NOFILE 20
2451 #endif
2452 	    {
2453 		int fd;
2454 
2455 		for (fd = PL_maxsysfd + 1; fd < NOFILE; fd++)
2456 		    if (fd != pp[1])
2457 			PerlLIO_close(fd);
2458 	    }
2459 #endif
2460 	    /* may or may not use the shell */
2461 	    do_exec3(cmd, pp[1], did_pipes);
2462 	    PerlProc__exit(1);
2463 	}
2464 #endif	/* defined OS2 */
2465 
2466 #ifdef PERLIO_USING_CRLF
2467    /* Since we circumvent IO layers when we manipulate low-level
2468       filedescriptors directly, need to manually switch to the
2469       default, binary, low-level mode; see PerlIOBuf_open(). */
2470    PerlLIO_setmode((*mode == 'r'), O_BINARY);
2471 #endif
2472 	PL_forkprocess = 0;
2473 #ifdef PERL_USES_PL_PIDSTATUS
2474 	hv_clear(PL_pidstatus);	/* we have no children */
2475 #endif
2476 	return NULL;
2477 #undef THIS
2478 #undef THAT
2479     }
2480     if (did_pipes)
2481 	PerlLIO_close(pp[1]);
2482     if (p[that] < p[This]) {
2483 	PerlLIO_dup2_cloexec(p[This], p[that]);
2484 	PerlLIO_close(p[This]);
2485 	p[This] = p[that];
2486     }
2487     else
2488 	PerlLIO_close(p[that]);
2489 
2490     sv = *av_fetch(PL_fdpid,p[This],TRUE);
2491     SvUPGRADE(sv,SVt_IV);
2492     SvIV_set(sv, pid);
2493     PL_forkprocess = pid;
2494     if (did_pipes && pid > 0) {
2495 	int errkid;
2496 	unsigned n = 0;
2497 
2498 	while (n < sizeof(int)) {
2499             const SSize_t n1 = PerlLIO_read(pp[0],
2500 			      (void*)(((char*)&errkid)+n),
2501 			      (sizeof(int)) - n);
2502 	    if (n1 <= 0)
2503 		break;
2504 	    n += n1;
2505 	}
2506 	PerlLIO_close(pp[0]);
2507 	did_pipes = 0;
2508 	if (n) {			/* Error */
2509 	    int pid2, status;
2510 	    PerlLIO_close(p[This]);
2511 	    if (n != sizeof(int))
2512 		Perl_croak(aTHX_ "panic: kid popen errno read, n=%u", n);
2513 	    do {
2514 		pid2 = wait4pid(pid, &status, 0);
2515 	    } while (pid2 == -1 && errno == EINTR);
2516 	    errno = errkid;		/* Propagate errno from kid */
2517 	    return NULL;
2518 	}
2519     }
2520     if (did_pipes)
2521 	 PerlLIO_close(pp[0]);
2522     return PerlIO_fdopen(p[This], mode);
2523 }
2524 #elif defined(DJGPP)
2525 FILE *djgpp_popen();
2526 PerlIO *
2527 Perl_my_popen(pTHX_ const char *cmd, const char *mode)
2528 {
2529     PERL_FLUSHALL_FOR_CHILD;
2530     /* Call system's popen() to get a FILE *, then import it.
2531        used 0 for 2nd parameter to PerlIO_importFILE;
2532        apparently not used
2533     */
2534     return PerlIO_importFILE(djgpp_popen(cmd, mode), 0);
2535 }
2536 #elif defined(__LIBCATAMOUNT__)
2537 PerlIO *
2538 Perl_my_popen(pTHX_ const char *cmd, const char *mode)
2539 {
2540     return NULL;
2541 }
2542 
2543 #endif /* !DOSISH */
2544 
2545 /* this is called in parent before the fork() */
2546 void
2547 Perl_atfork_lock(void)
2548 #if defined(USE_ITHREADS)
2549 #  ifdef USE_PERLIO
2550   PERL_TSA_ACQUIRE(PL_perlio_mutex)
2551 #  endif
2552 #  ifdef MYMALLOC
2553   PERL_TSA_ACQUIRE(PL_malloc_mutex)
2554 #  endif
2555   PERL_TSA_ACQUIRE(PL_op_mutex)
2556 #endif
2557 {
2558 #if defined(USE_ITHREADS)
2559     dVAR;
2560     /* locks must be held in locking order (if any) */
2561 #  ifdef USE_PERLIO
2562     MUTEX_LOCK(&PL_perlio_mutex);
2563 #  endif
2564 #  ifdef MYMALLOC
2565     MUTEX_LOCK(&PL_malloc_mutex);
2566 #  endif
2567     OP_REFCNT_LOCK;
2568 #endif
2569 }
2570 
2571 /* this is called in both parent and child after the fork() */
2572 void
2573 Perl_atfork_unlock(void)
2574 #if defined(USE_ITHREADS)
2575 #  ifdef USE_PERLIO
2576   PERL_TSA_RELEASE(PL_perlio_mutex)
2577 #  endif
2578 #  ifdef MYMALLOC
2579   PERL_TSA_RELEASE(PL_malloc_mutex)
2580 #  endif
2581   PERL_TSA_RELEASE(PL_op_mutex)
2582 #endif
2583 {
2584 #if defined(USE_ITHREADS)
2585     dVAR;
2586     /* locks must be released in same order as in atfork_lock() */
2587 #  ifdef USE_PERLIO
2588     MUTEX_UNLOCK(&PL_perlio_mutex);
2589 #  endif
2590 #  ifdef MYMALLOC
2591     MUTEX_UNLOCK(&PL_malloc_mutex);
2592 #  endif
2593     OP_REFCNT_UNLOCK;
2594 #endif
2595 }
2596 
2597 Pid_t
2598 Perl_my_fork(void)
2599 {
2600 #if defined(HAS_FORK)
2601     Pid_t pid;
2602 #if defined(USE_ITHREADS) && !defined(HAS_PTHREAD_ATFORK)
2603     atfork_lock();
2604     pid = fork();
2605     atfork_unlock();
2606 #else
2607     /* atfork_lock() and atfork_unlock() are installed as pthread_atfork()
2608      * handlers elsewhere in the code */
2609     pid = fork();
2610 #endif
2611     return pid;
2612 #elif defined(__amigaos4__)
2613     return amigaos_fork();
2614 #else
2615     /* this "canna happen" since nothing should be calling here if !HAS_FORK */
2616     Perl_croak_nocontext("fork() not available");
2617     return 0;
2618 #endif /* HAS_FORK */
2619 }
2620 
2621 #ifndef HAS_DUP2
2622 int
2623 dup2(int oldfd, int newfd)
2624 {
2625 #if defined(HAS_FCNTL) && defined(F_DUPFD)
2626     if (oldfd == newfd)
2627 	return oldfd;
2628     PerlLIO_close(newfd);
2629     return fcntl(oldfd, F_DUPFD, newfd);
2630 #else
2631 #define DUP2_MAX_FDS 256
2632     int fdtmp[DUP2_MAX_FDS];
2633     I32 fdx = 0;
2634     int fd;
2635 
2636     if (oldfd == newfd)
2637 	return oldfd;
2638     PerlLIO_close(newfd);
2639     /* good enough for low fd's... */
2640     while ((fd = PerlLIO_dup(oldfd)) != newfd && fd >= 0) {
2641 	if (fdx >= DUP2_MAX_FDS) {
2642 	    PerlLIO_close(fd);
2643 	    fd = -1;
2644 	    break;
2645 	}
2646 	fdtmp[fdx++] = fd;
2647     }
2648     while (fdx > 0)
2649 	PerlLIO_close(fdtmp[--fdx]);
2650     return fd;
2651 #endif
2652 }
2653 #endif
2654 
2655 #ifndef PERL_MICRO
2656 #ifdef HAS_SIGACTION
2657 
2658 Sighandler_t
2659 Perl_rsignal(pTHX_ int signo, Sighandler_t handler)
2660 {
2661     struct sigaction act, oact;
2662 
2663 #ifdef USE_ITHREADS
2664     dVAR;
2665     /* only "parent" interpreter can diddle signals */
2666     if (PL_curinterp != aTHX)
2667 	return (Sighandler_t) SIG_ERR;
2668 #endif
2669 
2670     act.sa_handler = (void(*)(int))handler;
2671     sigemptyset(&act.sa_mask);
2672     act.sa_flags = 0;
2673 #ifdef SA_RESTART
2674     if (PL_signals & PERL_SIGNALS_UNSAFE_FLAG)
2675         act.sa_flags |= SA_RESTART;	/* SVR4, 4.3+BSD */
2676 #endif
2677 #if defined(SA_NOCLDWAIT) && !defined(BSDish) /* See [perl #18849] */
2678     if (signo == SIGCHLD && handler == (Sighandler_t) SIG_IGN)
2679 	act.sa_flags |= SA_NOCLDWAIT;
2680 #endif
2681     if (sigaction(signo, &act, &oact) == -1)
2682     	return (Sighandler_t) SIG_ERR;
2683     else
2684     	return (Sighandler_t) oact.sa_handler;
2685 }
2686 
2687 Sighandler_t
2688 Perl_rsignal_state(pTHX_ int signo)
2689 {
2690     struct sigaction oact;
2691     PERL_UNUSED_CONTEXT;
2692 
2693     if (sigaction(signo, (struct sigaction *)NULL, &oact) == -1)
2694 	return (Sighandler_t) SIG_ERR;
2695     else
2696 	return (Sighandler_t) oact.sa_handler;
2697 }
2698 
2699 int
2700 Perl_rsignal_save(pTHX_ int signo, Sighandler_t handler, Sigsave_t *save)
2701 {
2702 #ifdef USE_ITHREADS
2703     dVAR;
2704 #endif
2705     struct sigaction act;
2706 
2707     PERL_ARGS_ASSERT_RSIGNAL_SAVE;
2708 
2709 #ifdef USE_ITHREADS
2710     /* only "parent" interpreter can diddle signals */
2711     if (PL_curinterp != aTHX)
2712 	return -1;
2713 #endif
2714 
2715     act.sa_handler = (void(*)(int))handler;
2716     sigemptyset(&act.sa_mask);
2717     act.sa_flags = 0;
2718 #ifdef SA_RESTART
2719     if (PL_signals & PERL_SIGNALS_UNSAFE_FLAG)
2720         act.sa_flags |= SA_RESTART;	/* SVR4, 4.3+BSD */
2721 #endif
2722 #if defined(SA_NOCLDWAIT) && !defined(BSDish) /* See [perl #18849] */
2723     if (signo == SIGCHLD && handler == (Sighandler_t) SIG_IGN)
2724 	act.sa_flags |= SA_NOCLDWAIT;
2725 #endif
2726     return sigaction(signo, &act, save);
2727 }
2728 
2729 int
2730 Perl_rsignal_restore(pTHX_ int signo, Sigsave_t *save)
2731 {
2732 #ifdef USE_ITHREADS
2733     dVAR;
2734 #endif
2735     PERL_UNUSED_CONTEXT;
2736 #ifdef USE_ITHREADS
2737     /* only "parent" interpreter can diddle signals */
2738     if (PL_curinterp != aTHX)
2739 	return -1;
2740 #endif
2741 
2742     return sigaction(signo, save, (struct sigaction *)NULL);
2743 }
2744 
2745 #else /* !HAS_SIGACTION */
2746 
2747 Sighandler_t
2748 Perl_rsignal(pTHX_ int signo, Sighandler_t handler)
2749 {
2750 #if defined(USE_ITHREADS) && !defined(WIN32)
2751     /* only "parent" interpreter can diddle signals */
2752     if (PL_curinterp != aTHX)
2753 	return (Sighandler_t) SIG_ERR;
2754 #endif
2755 
2756     return PerlProc_signal(signo, handler);
2757 }
2758 
2759 static Signal_t
2760 sig_trap(int signo)
2761 {
2762     dVAR;
2763     PL_sig_trapped++;
2764 }
2765 
2766 Sighandler_t
2767 Perl_rsignal_state(pTHX_ int signo)
2768 {
2769     dVAR;
2770     Sighandler_t oldsig;
2771 
2772 #if defined(USE_ITHREADS) && !defined(WIN32)
2773     /* only "parent" interpreter can diddle signals */
2774     if (PL_curinterp != aTHX)
2775 	return (Sighandler_t) SIG_ERR;
2776 #endif
2777 
2778     PL_sig_trapped = 0;
2779     oldsig = PerlProc_signal(signo, sig_trap);
2780     PerlProc_signal(signo, oldsig);
2781     if (PL_sig_trapped)
2782 	PerlProc_kill(PerlProc_getpid(), signo);
2783     return oldsig;
2784 }
2785 
2786 int
2787 Perl_rsignal_save(pTHX_ int signo, Sighandler_t handler, Sigsave_t *save)
2788 {
2789 #if defined(USE_ITHREADS) && !defined(WIN32)
2790     /* only "parent" interpreter can diddle signals */
2791     if (PL_curinterp != aTHX)
2792 	return -1;
2793 #endif
2794     *save = PerlProc_signal(signo, handler);
2795     return (*save == (Sighandler_t) SIG_ERR) ? -1 : 0;
2796 }
2797 
2798 int
2799 Perl_rsignal_restore(pTHX_ int signo, Sigsave_t *save)
2800 {
2801 #if defined(USE_ITHREADS) && !defined(WIN32)
2802     /* only "parent" interpreter can diddle signals */
2803     if (PL_curinterp != aTHX)
2804 	return -1;
2805 #endif
2806     return (PerlProc_signal(signo, *save) == (Sighandler_t) SIG_ERR) ? -1 : 0;
2807 }
2808 
2809 #endif /* !HAS_SIGACTION */
2810 #endif /* !PERL_MICRO */
2811 
2812     /* VMS' my_pclose() is in VMS.c; same with OS/2 */
2813 #if (!defined(DOSISH) || defined(HAS_FORK)) && !defined(VMS) && !defined(__LIBCATAMOUNT__) && !defined(__amigaos4__)
2814 I32
2815 Perl_my_pclose(pTHX_ PerlIO *ptr)
2816 {
2817     int status;
2818     SV **svp;
2819     Pid_t pid;
2820     Pid_t pid2 = 0;
2821     bool close_failed;
2822     dSAVEDERRNO;
2823     const int fd = PerlIO_fileno(ptr);
2824     bool should_wait;
2825 
2826     svp = av_fetch(PL_fdpid,fd,TRUE);
2827     pid = (SvTYPE(*svp) == SVt_IV) ? SvIVX(*svp) : -1;
2828     SvREFCNT_dec(*svp);
2829     *svp = NULL;
2830 
2831 #if defined(USE_PERLIO)
2832     /* Find out whether the refcount is low enough for us to wait for the
2833        child proc without blocking. */
2834     should_wait = PerlIOUnix_refcnt(fd) == 1 && pid > 0;
2835 #else
2836     should_wait = pid > 0;
2837 #endif
2838 
2839 #ifdef OS2
2840     if (pid == -1) {			/* Opened by popen. */
2841 	return my_syspclose(ptr);
2842     }
2843 #endif
2844     close_failed = (PerlIO_close(ptr) == EOF);
2845     SAVE_ERRNO;
2846     if (should_wait) do {
2847 	pid2 = wait4pid(pid, &status, 0);
2848     } while (pid2 == -1 && errno == EINTR);
2849     if (close_failed) {
2850 	RESTORE_ERRNO;
2851 	return -1;
2852     }
2853     return(
2854       should_wait
2855        ? pid2 < 0 ? pid2 : status == 0 ? 0 : (errno = 0, status)
2856        : 0
2857     );
2858 }
2859 #elif defined(__LIBCATAMOUNT__)
2860 I32
2861 Perl_my_pclose(pTHX_ PerlIO *ptr)
2862 {
2863     return -1;
2864 }
2865 #endif /* !DOSISH */
2866 
2867 #if  (!defined(DOSISH) || defined(OS2) || defined(WIN32) || defined(NETWARE)) && !defined(__LIBCATAMOUNT__)
2868 I32
2869 Perl_wait4pid(pTHX_ Pid_t pid, int *statusp, int flags)
2870 {
2871     I32 result = 0;
2872     PERL_ARGS_ASSERT_WAIT4PID;
2873 #ifdef PERL_USES_PL_PIDSTATUS
2874     if (!pid) {
2875         /* PERL_USES_PL_PIDSTATUS is only defined when neither
2876            waitpid() nor wait4() is available, or on OS/2, which
2877            doesn't appear to support waiting for a progress group
2878            member, so we can only treat a 0 pid as an unknown child.
2879         */
2880         errno = ECHILD;
2881         return -1;
2882     }
2883     {
2884 	if (pid > 0) {
2885 	    /* The keys in PL_pidstatus are now the raw 4 (or 8) bytes of the
2886 	       pid, rather than a string form.  */
2887 	    SV * const * const svp = hv_fetch(PL_pidstatus,(const char*) &pid,sizeof(Pid_t),FALSE);
2888 	    if (svp && *svp != &PL_sv_undef) {
2889 		*statusp = SvIVX(*svp);
2890 		(void)hv_delete(PL_pidstatus,(const char*) &pid,sizeof(Pid_t),
2891 				G_DISCARD);
2892 		return pid;
2893 	    }
2894 	}
2895 	else {
2896 	    HE *entry;
2897 
2898 	    hv_iterinit(PL_pidstatus);
2899 	    if ((entry = hv_iternext(PL_pidstatus))) {
2900 		SV * const sv = hv_iterval(PL_pidstatus,entry);
2901 		I32 len;
2902 		const char * const spid = hv_iterkey(entry,&len);
2903 
2904 		assert (len == sizeof(Pid_t));
2905 		memcpy((char *)&pid, spid, len);
2906 		*statusp = SvIVX(sv);
2907 		/* The hash iterator is currently on this entry, so simply
2908 		   calling hv_delete would trigger the lazy delete, which on
2909 		   aggregate does more work, because next call to hv_iterinit()
2910 		   would spot the flag, and have to call the delete routine,
2911 		   while in the meantime any new entries can't re-use that
2912 		   memory.  */
2913 		hv_iterinit(PL_pidstatus);
2914 		(void)hv_delete(PL_pidstatus,spid,len,G_DISCARD);
2915 		return pid;
2916 	    }
2917 	}
2918     }
2919 #endif
2920 #ifdef HAS_WAITPID
2921 #  ifdef HAS_WAITPID_RUNTIME
2922     if (!HAS_WAITPID_RUNTIME)
2923 	goto hard_way;
2924 #  endif
2925     result = PerlProc_waitpid(pid,statusp,flags);
2926     goto finish;
2927 #endif
2928 #if !defined(HAS_WAITPID) && defined(HAS_WAIT4)
2929     result = wait4(pid,statusp,flags,NULL);
2930     goto finish;
2931 #endif
2932 #ifdef PERL_USES_PL_PIDSTATUS
2933 #if defined(HAS_WAITPID) && defined(HAS_WAITPID_RUNTIME)
2934   hard_way:
2935 #endif
2936     {
2937 	if (flags)
2938 	    Perl_croak(aTHX_ "Can't do waitpid with flags");
2939 	else {
2940 	    while ((result = PerlProc_wait(statusp)) != pid && pid > 0 && result >= 0)
2941 		pidgone(result,*statusp);
2942 	    if (result < 0)
2943 		*statusp = -1;
2944 	}
2945     }
2946 #endif
2947 #if defined(HAS_WAITPID) || defined(HAS_WAIT4)
2948   finish:
2949 #endif
2950     if (result < 0 && errno == EINTR) {
2951 	PERL_ASYNC_CHECK();
2952 	errno = EINTR; /* reset in case a signal handler changed $! */
2953     }
2954     return result;
2955 }
2956 #endif /* !DOSISH || OS2 || WIN32 || NETWARE */
2957 
2958 #ifdef PERL_USES_PL_PIDSTATUS
2959 void
2960 S_pidgone(pTHX_ Pid_t pid, int status)
2961 {
2962     SV *sv;
2963 
2964     sv = *hv_fetch(PL_pidstatus,(const char*)&pid,sizeof(Pid_t),TRUE);
2965     SvUPGRADE(sv,SVt_IV);
2966     SvIV_set(sv, status);
2967     return;
2968 }
2969 #endif
2970 
2971 #if defined(OS2)
2972 int pclose();
2973 #ifdef HAS_FORK
2974 int					/* Cannot prototype with I32
2975 					   in os2ish.h. */
2976 my_syspclose(PerlIO *ptr)
2977 #else
2978 I32
2979 Perl_my_pclose(pTHX_ PerlIO *ptr)
2980 #endif
2981 {
2982     /* Needs work for PerlIO ! */
2983     FILE * const f = PerlIO_findFILE(ptr);
2984     const I32 result = pclose(f);
2985     PerlIO_releaseFILE(ptr,f);
2986     return result;
2987 }
2988 #endif
2989 
2990 #if defined(DJGPP)
2991 int djgpp_pclose();
2992 I32
2993 Perl_my_pclose(pTHX_ PerlIO *ptr)
2994 {
2995     /* Needs work for PerlIO ! */
2996     FILE * const f = PerlIO_findFILE(ptr);
2997     I32 result = djgpp_pclose(f);
2998     result = (result << 8) & 0xff00;
2999     PerlIO_releaseFILE(ptr,f);
3000     return result;
3001 }
3002 #endif
3003 
3004 #define PERL_REPEATCPY_LINEAR 4
3005 void
3006 Perl_repeatcpy(char *to, const char *from, I32 len, IV count)
3007 {
3008     PERL_ARGS_ASSERT_REPEATCPY;
3009 
3010     assert(len >= 0);
3011 
3012     if (count < 0)
3013 	croak_memory_wrap();
3014 
3015     if (len == 1)
3016 	memset(to, *from, count);
3017     else if (count) {
3018 	char *p = to;
3019 	IV items, linear, half;
3020 
3021 	linear = count < PERL_REPEATCPY_LINEAR ? count : PERL_REPEATCPY_LINEAR;
3022 	for (items = 0; items < linear; ++items) {
3023 	    const char *q = from;
3024 	    IV todo;
3025 	    for (todo = len; todo > 0; todo--)
3026 		*p++ = *q++;
3027         }
3028 
3029 	half = count / 2;
3030 	while (items <= half) {
3031 	    IV size = items * len;
3032 	    memcpy(p, to, size);
3033 	    p     += size;
3034 	    items *= 2;
3035 	}
3036 
3037 	if (count > items)
3038 	    memcpy(p, to, (count - items) * len);
3039     }
3040 }
3041 
3042 #ifndef HAS_RENAME
3043 I32
3044 Perl_same_dirent(pTHX_ const char *a, const char *b)
3045 {
3046     char *fa = strrchr(a,'/');
3047     char *fb = strrchr(b,'/');
3048     Stat_t tmpstatbuf1;
3049     Stat_t tmpstatbuf2;
3050     SV * const tmpsv = sv_newmortal();
3051 
3052     PERL_ARGS_ASSERT_SAME_DIRENT;
3053 
3054     if (fa)
3055 	fa++;
3056     else
3057 	fa = a;
3058     if (fb)
3059 	fb++;
3060     else
3061 	fb = b;
3062     if (strNE(a,b))
3063 	return FALSE;
3064     if (fa == a)
3065 	sv_setpvs(tmpsv, ".");
3066     else
3067 	sv_setpvn(tmpsv, a, fa - a);
3068     if (PerlLIO_stat(SvPVX_const(tmpsv), &tmpstatbuf1) < 0)
3069 	return FALSE;
3070     if (fb == b)
3071 	sv_setpvs(tmpsv, ".");
3072     else
3073 	sv_setpvn(tmpsv, b, fb - b);
3074     if (PerlLIO_stat(SvPVX_const(tmpsv), &tmpstatbuf2) < 0)
3075 	return FALSE;
3076     return tmpstatbuf1.st_dev == tmpstatbuf2.st_dev &&
3077 	   tmpstatbuf1.st_ino == tmpstatbuf2.st_ino;
3078 }
3079 #endif /* !HAS_RENAME */
3080 
3081 char*
3082 Perl_find_script(pTHX_ const char *scriptname, bool dosearch,
3083 		 const char *const *const search_ext, I32 flags)
3084 {
3085     const char *xfound = NULL;
3086     char *xfailed = NULL;
3087     char tmpbuf[MAXPATHLEN];
3088     char *s;
3089     I32 len = 0;
3090     int retval;
3091     char *bufend;
3092 #if defined(DOSISH) && !defined(OS2)
3093 #  define SEARCH_EXTS ".bat", ".cmd", NULL
3094 #  define MAX_EXT_LEN 4
3095 #endif
3096 #ifdef OS2
3097 #  define SEARCH_EXTS ".cmd", ".btm", ".bat", ".pl", NULL
3098 #  define MAX_EXT_LEN 4
3099 #endif
3100 #ifdef VMS
3101 #  define SEARCH_EXTS ".pl", ".com", NULL
3102 #  define MAX_EXT_LEN 4
3103 #endif
3104     /* additional extensions to try in each dir if scriptname not found */
3105 #ifdef SEARCH_EXTS
3106     static const char *const exts[] = { SEARCH_EXTS };
3107     const char *const *const ext = search_ext ? search_ext : exts;
3108     int extidx = 0, i = 0;
3109     const char *curext = NULL;
3110 #else
3111     PERL_UNUSED_ARG(search_ext);
3112 #  define MAX_EXT_LEN 0
3113 #endif
3114 
3115     PERL_ARGS_ASSERT_FIND_SCRIPT;
3116 
3117     /*
3118      * If dosearch is true and if scriptname does not contain path
3119      * delimiters, search the PATH for scriptname.
3120      *
3121      * If SEARCH_EXTS is also defined, will look for each
3122      * scriptname{SEARCH_EXTS} whenever scriptname is not found
3123      * while searching the PATH.
3124      *
3125      * Assuming SEARCH_EXTS is C<".foo",".bar",NULL>, PATH search
3126      * proceeds as follows:
3127      *   If DOSISH or VMSISH:
3128      *     + look for ./scriptname{,.foo,.bar}
3129      *     + search the PATH for scriptname{,.foo,.bar}
3130      *
3131      *   If !DOSISH:
3132      *     + look *only* in the PATH for scriptname{,.foo,.bar} (note
3133      *       this will not look in '.' if it's not in the PATH)
3134      */
3135     tmpbuf[0] = '\0';
3136 
3137 #ifdef VMS
3138 #  ifdef ALWAYS_DEFTYPES
3139     len = strlen(scriptname);
3140     if (!(len == 1 && *scriptname == '-') && scriptname[len-1] != ':') {
3141 	int idx = 0, deftypes = 1;
3142 	bool seen_dot = 1;
3143 
3144 	const int hasdir = !dosearch || (strpbrk(scriptname,":[</") != NULL);
3145 #  else
3146     if (dosearch) {
3147 	int idx = 0, deftypes = 1;
3148 	bool seen_dot = 1;
3149 
3150 	const int hasdir = (strpbrk(scriptname,":[</") != NULL);
3151 #  endif
3152 	/* The first time through, just add SEARCH_EXTS to whatever we
3153 	 * already have, so we can check for default file types. */
3154 	while (deftypes ||
3155 	       (!hasdir && my_trnlnm("DCL$PATH",tmpbuf,idx++)) )
3156 	{
3157 	    Stat_t statbuf;
3158 	    if (deftypes) {
3159 		deftypes = 0;
3160 		*tmpbuf = '\0';
3161 	    }
3162 	    if ((strlen(tmpbuf) + strlen(scriptname)
3163 		 + MAX_EXT_LEN) >= sizeof tmpbuf)
3164 		continue;	/* don't search dir with too-long name */
3165 	    my_strlcat(tmpbuf, scriptname, sizeof(tmpbuf));
3166 #else  /* !VMS */
3167 
3168 #ifdef DOSISH
3169     if (strEQ(scriptname, "-"))
3170  	dosearch = 0;
3171     if (dosearch) {		/* Look in '.' first. */
3172 	const char *cur = scriptname;
3173 #ifdef SEARCH_EXTS
3174 	if ((curext = strrchr(scriptname,'.')))	/* possible current ext */
3175 	    while (ext[i])
3176 		if (strEQ(ext[i++],curext)) {
3177 		    extidx = -1;		/* already has an ext */
3178 		    break;
3179 		}
3180 	do {
3181 #endif
3182 	    DEBUG_p(PerlIO_printf(Perl_debug_log,
3183 				  "Looking for %s\n",cur));
3184 	    {
3185 		Stat_t statbuf;
3186 		if (PerlLIO_stat(cur,&statbuf) >= 0
3187 		    && !S_ISDIR(statbuf.st_mode)) {
3188 		    dosearch = 0;
3189 		    scriptname = cur;
3190 #ifdef SEARCH_EXTS
3191 		    break;
3192 #endif
3193 		}
3194 	    }
3195 #ifdef SEARCH_EXTS
3196 	    if (cur == scriptname) {
3197 		len = strlen(scriptname);
3198 		if (len+MAX_EXT_LEN+1 >= sizeof(tmpbuf))
3199 		    break;
3200 		my_strlcpy(tmpbuf, scriptname, sizeof(tmpbuf));
3201 		cur = tmpbuf;
3202 	    }
3203 	} while (extidx >= 0 && ext[extidx]	/* try an extension? */
3204 		 && my_strlcpy(tmpbuf+len, ext[extidx++], sizeof(tmpbuf) - len));
3205 #endif
3206     }
3207 #endif
3208 
3209     if (dosearch && !strchr(scriptname, '/')
3210 #ifdef DOSISH
3211 		 && !strchr(scriptname, '\\')
3212 #endif
3213 		 && (s = PerlEnv_getenv("PATH")))
3214     {
3215 	bool seen_dot = 0;
3216 
3217 	bufend = s + strlen(s);
3218 	while (s < bufend) {
3219 	    Stat_t statbuf;
3220 #  ifdef DOSISH
3221 	    for (len = 0; *s
3222 		    && *s != ';'; len++, s++) {
3223 		if (len < sizeof tmpbuf)
3224 		    tmpbuf[len] = *s;
3225 	    }
3226 	    if (len < sizeof tmpbuf)
3227 		tmpbuf[len] = '\0';
3228 #  else
3229 	    s = delimcpy_no_escape(tmpbuf, tmpbuf + sizeof tmpbuf, s, bufend,
3230                                    ':', &len);
3231 #  endif
3232 	    if (s < bufend)
3233 		s++;
3234 	    if (len + 1 + strlen(scriptname) + MAX_EXT_LEN >= sizeof tmpbuf)
3235 		continue;	/* don't search dir with too-long name */
3236 	    if (len
3237 #  ifdef DOSISH
3238 		&& tmpbuf[len - 1] != '/'
3239 		&& tmpbuf[len - 1] != '\\'
3240 #  endif
3241 	       )
3242 		tmpbuf[len++] = '/';
3243 	    if (len == 2 && tmpbuf[0] == '.')
3244 		seen_dot = 1;
3245 	    (void)my_strlcpy(tmpbuf + len, scriptname, sizeof(tmpbuf) - len);
3246 #endif  /* !VMS */
3247 
3248 #ifdef SEARCH_EXTS
3249 	    len = strlen(tmpbuf);
3250 	    if (extidx > 0)	/* reset after previous loop */
3251 		extidx = 0;
3252 	    do {
3253 #endif
3254 	    	DEBUG_p(PerlIO_printf(Perl_debug_log, "Looking for %s\n",tmpbuf));
3255 		retval = PerlLIO_stat(tmpbuf,&statbuf);
3256 		if (S_ISDIR(statbuf.st_mode)) {
3257 		    retval = -1;
3258 		}
3259 #ifdef SEARCH_EXTS
3260 	    } while (  retval < 0		/* not there */
3261 		    && extidx>=0 && ext[extidx]	/* try an extension? */
3262 		    && my_strlcpy(tmpbuf+len, ext[extidx++], sizeof(tmpbuf) - len)
3263 		);
3264 #endif
3265 	    if (retval < 0)
3266 		continue;
3267 	    if (S_ISREG(statbuf.st_mode)
3268 		&& cando(S_IRUSR,TRUE,&statbuf)
3269 #if !defined(DOSISH)
3270 		&& cando(S_IXUSR,TRUE,&statbuf)
3271 #endif
3272 		)
3273 	    {
3274 		xfound = tmpbuf;		/* bingo! */
3275 		break;
3276 	    }
3277 	    if (!xfailed)
3278 		xfailed = savepv(tmpbuf);
3279 	}
3280 #ifndef DOSISH
3281 	{
3282 	    Stat_t statbuf;
3283 	    if (!xfound && !seen_dot && !xfailed &&
3284 		(PerlLIO_stat(scriptname,&statbuf) < 0
3285 		 || S_ISDIR(statbuf.st_mode)))
3286 #endif
3287 		seen_dot = 1;			/* Disable message. */
3288 #ifndef DOSISH
3289 	}
3290 #endif
3291 	if (!xfound) {
3292 	    if (flags & 1) {			/* do or die? */
3293 		/* diag_listed_as: Can't execute %s */
3294 		Perl_croak(aTHX_ "Can't %s %s%s%s",
3295 		      (xfailed ? "execute" : "find"),
3296 		      (xfailed ? xfailed : scriptname),
3297 		      (xfailed ? "" : " on PATH"),
3298 		      (xfailed || seen_dot) ? "" : ", '.' not in PATH");
3299 	    }
3300 	    scriptname = NULL;
3301 	}
3302 	Safefree(xfailed);
3303 	scriptname = xfound;
3304     }
3305     return (scriptname ? savepv(scriptname) : NULL);
3306 }
3307 
3308 #ifndef PERL_GET_CONTEXT_DEFINED
3309 
3310 void *
3311 Perl_get_context(void)
3312 {
3313 #if defined(USE_ITHREADS)
3314     dVAR;
3315 #  ifdef OLD_PTHREADS_API
3316     pthread_addr_t t;
3317     int error = pthread_getspecific(PL_thr_key, &t)
3318     if (error)
3319 	Perl_croak_nocontext("panic: pthread_getspecific, error=%d", error);
3320     return (void*)t;
3321 #  elif defined(I_MACH_CTHREADS)
3322     return (void*)cthread_data(cthread_self());
3323 #  else
3324     return (void*)PTHREAD_GETSPECIFIC(PL_thr_key);
3325 #  endif
3326 #else
3327     return (void*)NULL;
3328 #endif
3329 }
3330 
3331 void
3332 Perl_set_context(void *t)
3333 {
3334 #if defined(USE_ITHREADS)
3335     dVAR;
3336 #endif
3337     PERL_ARGS_ASSERT_SET_CONTEXT;
3338 #if defined(USE_ITHREADS)
3339 #  ifdef I_MACH_CTHREADS
3340     cthread_set_data(cthread_self(), t);
3341 #  else
3342     {
3343 	const int error = pthread_setspecific(PL_thr_key, t);
3344 	if (error)
3345 	    Perl_croak_nocontext("panic: pthread_setspecific, error=%d", error);
3346     }
3347 #  endif
3348 #else
3349     PERL_UNUSED_ARG(t);
3350 #endif
3351 }
3352 
3353 #endif /* !PERL_GET_CONTEXT_DEFINED */
3354 
3355 #if defined(PERL_GLOBAL_STRUCT) && !defined(PERL_GLOBAL_STRUCT_PRIVATE)
3356 struct perl_vars *
3357 Perl_GetVars(pTHX)
3358 {
3359     PERL_UNUSED_CONTEXT;
3360     return &PL_Vars;
3361 }
3362 #endif
3363 
3364 char **
3365 Perl_get_op_names(pTHX)
3366 {
3367     PERL_UNUSED_CONTEXT;
3368     return (char **)PL_op_name;
3369 }
3370 
3371 char **
3372 Perl_get_op_descs(pTHX)
3373 {
3374     PERL_UNUSED_CONTEXT;
3375     return (char **)PL_op_desc;
3376 }
3377 
3378 const char *
3379 Perl_get_no_modify(pTHX)
3380 {
3381     PERL_UNUSED_CONTEXT;
3382     return PL_no_modify;
3383 }
3384 
3385 U32 *
3386 Perl_get_opargs(pTHX)
3387 {
3388     PERL_UNUSED_CONTEXT;
3389     return (U32 *)PL_opargs;
3390 }
3391 
3392 PPADDR_t*
3393 Perl_get_ppaddr(pTHX)
3394 {
3395     dVAR;
3396     PERL_UNUSED_CONTEXT;
3397     return (PPADDR_t*)PL_ppaddr;
3398 }
3399 
3400 #ifndef HAS_GETENV_LEN
3401 char *
3402 Perl_getenv_len(pTHX_ const char *env_elem, unsigned long *len)
3403 {
3404     char * const env_trans = PerlEnv_getenv(env_elem);
3405     PERL_UNUSED_CONTEXT;
3406     PERL_ARGS_ASSERT_GETENV_LEN;
3407     if (env_trans)
3408 	*len = strlen(env_trans);
3409     return env_trans;
3410 }
3411 #endif
3412 
3413 
3414 MGVTBL*
3415 Perl_get_vtbl(pTHX_ int vtbl_id)
3416 {
3417     PERL_UNUSED_CONTEXT;
3418 
3419     return (vtbl_id < 0 || vtbl_id >= magic_vtable_max)
3420 	? NULL : (MGVTBL*)PL_magic_vtables + vtbl_id;
3421 }
3422 
3423 I32
3424 Perl_my_fflush_all(pTHX)
3425 {
3426 #if defined(USE_PERLIO) || defined(FFLUSH_NULL)
3427     return PerlIO_flush(NULL);
3428 #else
3429 # if defined(HAS__FWALK)
3430     extern int fflush(FILE *);
3431     /* undocumented, unprototyped, but very useful BSDism */
3432     extern void _fwalk(int (*)(FILE *));
3433     _fwalk(&fflush);
3434     return 0;
3435 # else
3436 #  if defined(FFLUSH_ALL) && defined(HAS_STDIO_STREAM_ARRAY)
3437     long open_max = -1;
3438 #   ifdef PERL_FFLUSH_ALL_FOPEN_MAX
3439     open_max = PERL_FFLUSH_ALL_FOPEN_MAX;
3440 #   elif defined(HAS_SYSCONF) && defined(_SC_OPEN_MAX)
3441     open_max = sysconf(_SC_OPEN_MAX);
3442 #   elif defined(FOPEN_MAX)
3443     open_max = FOPEN_MAX;
3444 #   elif defined(OPEN_MAX)
3445     open_max = OPEN_MAX;
3446 #   elif defined(_NFILE)
3447     open_max = _NFILE;
3448 #   endif
3449     if (open_max > 0) {
3450       long i;
3451       for (i = 0; i < open_max; i++)
3452 	    if (STDIO_STREAM_ARRAY[i]._file >= 0 &&
3453 		STDIO_STREAM_ARRAY[i]._file < open_max &&
3454 		STDIO_STREAM_ARRAY[i]._flag)
3455 		PerlIO_flush(&STDIO_STREAM_ARRAY[i]);
3456       return 0;
3457     }
3458 #  endif
3459     SETERRNO(EBADF,RMS_IFI);
3460     return EOF;
3461 # endif
3462 #endif
3463 }
3464 
3465 void
3466 Perl_report_wrongway_fh(pTHX_ const GV *gv, const char have)
3467 {
3468     if (ckWARN(WARN_IO)) {
3469         HEK * const name
3470            = gv && (isGV_with_GP(gv))
3471                 ? GvENAME_HEK((gv))
3472                 : NULL;
3473 	const char * const direction = have == '>' ? "out" : "in";
3474 
3475 	if (name && HEK_LEN(name))
3476 	    Perl_warner(aTHX_ packWARN(WARN_IO),
3477 			"Filehandle %" HEKf " opened only for %sput",
3478 			HEKfARG(name), direction);
3479 	else
3480 	    Perl_warner(aTHX_ packWARN(WARN_IO),
3481 			"Filehandle opened only for %sput", direction);
3482     }
3483 }
3484 
3485 void
3486 Perl_report_evil_fh(pTHX_ const GV *gv)
3487 {
3488     const IO *io = gv ? GvIO(gv) : NULL;
3489     const PERL_BITFIELD16 op = PL_op->op_type;
3490     const char *vile;
3491     I32 warn_type;
3492 
3493     if (io && IoTYPE(io) == IoTYPE_CLOSED) {
3494 	vile = "closed";
3495 	warn_type = WARN_CLOSED;
3496     }
3497     else {
3498 	vile = "unopened";
3499 	warn_type = WARN_UNOPENED;
3500     }
3501 
3502     if (ckWARN(warn_type)) {
3503         SV * const name
3504             = gv && isGV_with_GP(gv) && GvENAMELEN(gv) ?
3505                                      sv_2mortal(newSVhek(GvENAME_HEK(gv))) : NULL;
3506 	const char * const pars =
3507 	    (const char *)(OP_IS_FILETEST(op) ? "" : "()");
3508 	const char * const func =
3509 	    (const char *)
3510 	    (op == OP_READLINE || op == OP_RCATLINE
3511 				 ? "readline"  :	/* "<HANDLE>" not nice */
3512 	     op == OP_LEAVEWRITE ? "write" :		/* "write exit" not nice */
3513 	     PL_op_desc[op]);
3514 	const char * const type =
3515 	    (const char *)
3516 	    (OP_IS_SOCKET(op) || (io && IoTYPE(io) == IoTYPE_SOCKET)
3517 	     ? "socket" : "filehandle");
3518 	const bool have_name = name && SvCUR(name);
3519 	Perl_warner(aTHX_ packWARN(warn_type),
3520 		   "%s%s on %s %s%s%" SVf, func, pars, vile, type,
3521 		    have_name ? " " : "",
3522 		    SVfARG(have_name ? name : &PL_sv_no));
3523 	if (io && IoDIRP(io) && !(IoFLAGS(io) & IOf_FAKE_DIRP))
3524 		Perl_warner(
3525 			    aTHX_ packWARN(warn_type),
3526 			"\t(Are you trying to call %s%s on dirhandle%s%" SVf "?)\n",
3527 			func, pars, have_name ? " " : "",
3528 			SVfARG(have_name ? name : &PL_sv_no)
3529 			    );
3530     }
3531 }
3532 
3533 /* To workaround core dumps from the uninitialised tm_zone we get the
3534  * system to give us a reasonable struct to copy.  This fix means that
3535  * strftime uses the tm_zone and tm_gmtoff values returned by
3536  * localtime(time()). That should give the desired result most of the
3537  * time. But probably not always!
3538  *
3539  * This does not address tzname aspects of NETaa14816.
3540  *
3541  */
3542 
3543 #ifdef __GLIBC__
3544 # ifndef STRUCT_TM_HASZONE
3545 #    define STRUCT_TM_HASZONE
3546 # endif
3547 #endif
3548 
3549 #ifdef STRUCT_TM_HASZONE /* Backward compat */
3550 # ifndef HAS_TM_TM_ZONE
3551 #    define HAS_TM_TM_ZONE
3552 # endif
3553 #endif
3554 
3555 void
3556 Perl_init_tm(pTHX_ struct tm *ptm)	/* see mktime, strftime and asctime */
3557 {
3558 #ifdef HAS_TM_TM_ZONE
3559     Time_t now;
3560     const struct tm* my_tm;
3561     PERL_UNUSED_CONTEXT;
3562     PERL_ARGS_ASSERT_INIT_TM;
3563     (void)time(&now);
3564     my_tm = localtime(&now);
3565     if (my_tm)
3566         Copy(my_tm, ptm, 1, struct tm);
3567 #else
3568     PERL_UNUSED_CONTEXT;
3569     PERL_ARGS_ASSERT_INIT_TM;
3570     PERL_UNUSED_ARG(ptm);
3571 #endif
3572 }
3573 
3574 /*
3575  * mini_mktime - normalise struct tm values without the localtime()
3576  * semantics (and overhead) of mktime().
3577  */
3578 void
3579 Perl_mini_mktime(struct tm *ptm)
3580 {
3581     int yearday;
3582     int secs;
3583     int month, mday, year, jday;
3584     int odd_cent, odd_year;
3585 
3586     PERL_ARGS_ASSERT_MINI_MKTIME;
3587 
3588 #define	DAYS_PER_YEAR	365
3589 #define	DAYS_PER_QYEAR	(4*DAYS_PER_YEAR+1)
3590 #define	DAYS_PER_CENT	(25*DAYS_PER_QYEAR-1)
3591 #define	DAYS_PER_QCENT	(4*DAYS_PER_CENT+1)
3592 #define	SECS_PER_HOUR	(60*60)
3593 #define	SECS_PER_DAY	(24*SECS_PER_HOUR)
3594 /* parentheses deliberately absent on these two, otherwise they don't work */
3595 #define	MONTH_TO_DAYS	153/5
3596 #define	DAYS_TO_MONTH	5/153
3597 /* offset to bias by March (month 4) 1st between month/mday & year finding */
3598 #define	YEAR_ADJUST	(4*MONTH_TO_DAYS+1)
3599 /* as used here, the algorithm leaves Sunday as day 1 unless we adjust it */
3600 #define	WEEKDAY_BIAS	6	/* (1+6)%7 makes Sunday 0 again */
3601 
3602 /*
3603  * Year/day algorithm notes:
3604  *
3605  * With a suitable offset for numeric value of the month, one can find
3606  * an offset into the year by considering months to have 30.6 (153/5) days,
3607  * using integer arithmetic (i.e., with truncation).  To avoid too much
3608  * messing about with leap days, we consider January and February to be
3609  * the 13th and 14th month of the previous year.  After that transformation,
3610  * we need the month index we use to be high by 1 from 'normal human' usage,
3611  * so the month index values we use run from 4 through 15.
3612  *
3613  * Given that, and the rules for the Gregorian calendar (leap years are those
3614  * divisible by 4 unless also divisible by 100, when they must be divisible
3615  * by 400 instead), we can simply calculate the number of days since some
3616  * arbitrary 'beginning of time' by futzing with the (adjusted) year number,
3617  * the days we derive from our month index, and adding in the day of the
3618  * month.  The value used here is not adjusted for the actual origin which
3619  * it normally would use (1 January A.D. 1), since we're not exposing it.
3620  * We're only building the value so we can turn around and get the
3621  * normalised values for the year, month, day-of-month, and day-of-year.
3622  *
3623  * For going backward, we need to bias the value we're using so that we find
3624  * the right year value.  (Basically, we don't want the contribution of
3625  * March 1st to the number to apply while deriving the year).  Having done
3626  * that, we 'count up' the contribution to the year number by accounting for
3627  * full quadracenturies (400-year periods) with their extra leap days, plus
3628  * the contribution from full centuries (to avoid counting in the lost leap
3629  * days), plus the contribution from full quad-years (to count in the normal
3630  * leap days), plus the leftover contribution from any non-leap years.
3631  * At this point, if we were working with an actual leap day, we'll have 0
3632  * days left over.  This is also true for March 1st, however.  So, we have
3633  * to special-case that result, and (earlier) keep track of the 'odd'
3634  * century and year contributions.  If we got 4 extra centuries in a qcent,
3635  * or 4 extra years in a qyear, then it's a leap day and we call it 29 Feb.
3636  * Otherwise, we add back in the earlier bias we removed (the 123 from
3637  * figuring in March 1st), find the month index (integer division by 30.6),
3638  * and the remainder is the day-of-month.  We then have to convert back to
3639  * 'real' months (including fixing January and February from being 14/15 in
3640  * the previous year to being in the proper year).  After that, to get
3641  * tm_yday, we work with the normalised year and get a new yearday value for
3642  * January 1st, which we subtract from the yearday value we had earlier,
3643  * representing the date we've re-built.  This is done from January 1
3644  * because tm_yday is 0-origin.
3645  *
3646  * Since POSIX time routines are only guaranteed to work for times since the
3647  * UNIX epoch (00:00:00 1 Jan 1970 UTC), the fact that this algorithm
3648  * applies Gregorian calendar rules even to dates before the 16th century
3649  * doesn't bother me.  Besides, you'd need cultural context for a given
3650  * date to know whether it was Julian or Gregorian calendar, and that's
3651  * outside the scope for this routine.  Since we convert back based on the
3652  * same rules we used to build the yearday, you'll only get strange results
3653  * for input which needed normalising, or for the 'odd' century years which
3654  * were leap years in the Julian calendar but not in the Gregorian one.
3655  * I can live with that.
3656  *
3657  * This algorithm also fails to handle years before A.D. 1 gracefully, but
3658  * that's still outside the scope for POSIX time manipulation, so I don't
3659  * care.
3660  *
3661  * - lwall
3662  */
3663 
3664     year = 1900 + ptm->tm_year;
3665     month = ptm->tm_mon;
3666     mday = ptm->tm_mday;
3667     jday = 0;
3668     if (month >= 2)
3669 	month+=2;
3670     else
3671 	month+=14, year--;
3672     yearday = DAYS_PER_YEAR * year + year/4 - year/100 + year/400;
3673     yearday += month*MONTH_TO_DAYS + mday + jday;
3674     /*
3675      * Note that we don't know when leap-seconds were or will be,
3676      * so we have to trust the user if we get something which looks
3677      * like a sensible leap-second.  Wild values for seconds will
3678      * be rationalised, however.
3679      */
3680     if ((unsigned) ptm->tm_sec <= 60) {
3681 	secs = 0;
3682     }
3683     else {
3684 	secs = ptm->tm_sec;
3685 	ptm->tm_sec = 0;
3686     }
3687     secs += 60 * ptm->tm_min;
3688     secs += SECS_PER_HOUR * ptm->tm_hour;
3689     if (secs < 0) {
3690 	if (secs-(secs/SECS_PER_DAY*SECS_PER_DAY) < 0) {
3691 	    /* got negative remainder, but need positive time */
3692 	    /* back off an extra day to compensate */
3693 	    yearday += (secs/SECS_PER_DAY)-1;
3694 	    secs -= SECS_PER_DAY * (secs/SECS_PER_DAY - 1);
3695 	}
3696 	else {
3697 	    yearday += (secs/SECS_PER_DAY);
3698 	    secs -= SECS_PER_DAY * (secs/SECS_PER_DAY);
3699 	}
3700     }
3701     else if (secs >= SECS_PER_DAY) {
3702 	yearday += (secs/SECS_PER_DAY);
3703 	secs %= SECS_PER_DAY;
3704     }
3705     ptm->tm_hour = secs/SECS_PER_HOUR;
3706     secs %= SECS_PER_HOUR;
3707     ptm->tm_min = secs/60;
3708     secs %= 60;
3709     ptm->tm_sec += secs;
3710     /* done with time of day effects */
3711     /*
3712      * The algorithm for yearday has (so far) left it high by 428.
3713      * To avoid mistaking a legitimate Feb 29 as Mar 1, we need to
3714      * bias it by 123 while trying to figure out what year it
3715      * really represents.  Even with this tweak, the reverse
3716      * translation fails for years before A.D. 0001.
3717      * It would still fail for Feb 29, but we catch that one below.
3718      */
3719     jday = yearday;	/* save for later fixup vis-a-vis Jan 1 */
3720     yearday -= YEAR_ADJUST;
3721     year = (yearday / DAYS_PER_QCENT) * 400;
3722     yearday %= DAYS_PER_QCENT;
3723     odd_cent = yearday / DAYS_PER_CENT;
3724     year += odd_cent * 100;
3725     yearday %= DAYS_PER_CENT;
3726     year += (yearday / DAYS_PER_QYEAR) * 4;
3727     yearday %= DAYS_PER_QYEAR;
3728     odd_year = yearday / DAYS_PER_YEAR;
3729     year += odd_year;
3730     yearday %= DAYS_PER_YEAR;
3731     if (!yearday && (odd_cent==4 || odd_year==4)) { /* catch Feb 29 */
3732 	month = 1;
3733 	yearday = 29;
3734     }
3735     else {
3736 	yearday += YEAR_ADJUST;	/* recover March 1st crock */
3737 	month = yearday*DAYS_TO_MONTH;
3738 	yearday -= month*MONTH_TO_DAYS;
3739 	/* recover other leap-year adjustment */
3740 	if (month > 13) {
3741 	    month-=14;
3742 	    year++;
3743 	}
3744 	else {
3745 	    month-=2;
3746 	}
3747     }
3748     ptm->tm_year = year - 1900;
3749     if (yearday) {
3750       ptm->tm_mday = yearday;
3751       ptm->tm_mon = month;
3752     }
3753     else {
3754       ptm->tm_mday = 31;
3755       ptm->tm_mon = month - 1;
3756     }
3757     /* re-build yearday based on Jan 1 to get tm_yday */
3758     year--;
3759     yearday = year*DAYS_PER_YEAR + year/4 - year/100 + year/400;
3760     yearday += 14*MONTH_TO_DAYS + 1;
3761     ptm->tm_yday = jday - yearday;
3762     ptm->tm_wday = (jday + WEEKDAY_BIAS) % 7;
3763 }
3764 
3765 char *
3766 Perl_my_strftime(pTHX_ const char *fmt, int sec, int min, int hour, int mday, int mon, int year, int wday, int yday, int isdst)
3767 {
3768 #ifdef HAS_STRFTIME
3769 
3770   /* strftime(), but with a different API so that the return value is a pointer
3771    * to the formatted result (which MUST be arranged to be FREED BY THE
3772    * CALLER).  This allows this function to increase the buffer size as needed,
3773    * so that the caller doesn't have to worry about that.
3774    *
3775    * Note that yday and wday effectively are ignored by this function, as
3776    * mini_mktime() overwrites them */
3777 
3778   char *buf;
3779   int buflen;
3780   struct tm mytm;
3781   int len;
3782 
3783   PERL_ARGS_ASSERT_MY_STRFTIME;
3784 
3785   init_tm(&mytm);	/* XXX workaround - see init_tm() above */
3786   mytm.tm_sec = sec;
3787   mytm.tm_min = min;
3788   mytm.tm_hour = hour;
3789   mytm.tm_mday = mday;
3790   mytm.tm_mon = mon;
3791   mytm.tm_year = year;
3792   mytm.tm_wday = wday;
3793   mytm.tm_yday = yday;
3794   mytm.tm_isdst = isdst;
3795   mini_mktime(&mytm);
3796   /* use libc to get the values for tm_gmtoff and tm_zone [perl #18238] */
3797 #if defined(HAS_MKTIME) && (defined(HAS_TM_TM_GMTOFF) || defined(HAS_TM_TM_ZONE))
3798   STMT_START {
3799     struct tm mytm2;
3800     mytm2 = mytm;
3801     mktime(&mytm2);
3802 #ifdef HAS_TM_TM_GMTOFF
3803     mytm.tm_gmtoff = mytm2.tm_gmtoff;
3804 #endif
3805 #ifdef HAS_TM_TM_ZONE
3806     mytm.tm_zone = mytm2.tm_zone;
3807 #endif
3808   } STMT_END;
3809 #endif
3810   buflen = 64;
3811   Newx(buf, buflen, char);
3812 
3813   GCC_DIAG_IGNORE_STMT(-Wformat-nonliteral); /* fmt checked by caller */
3814   len = strftime(buf, buflen, fmt, &mytm);
3815   GCC_DIAG_RESTORE_STMT;
3816 
3817   /*
3818   ** The following is needed to handle to the situation where
3819   ** tmpbuf overflows.  Basically we want to allocate a buffer
3820   ** and try repeatedly.  The reason why it is so complicated
3821   ** is that getting a return value of 0 from strftime can indicate
3822   ** one of the following:
3823   ** 1. buffer overflowed,
3824   ** 2. illegal conversion specifier, or
3825   ** 3. the format string specifies nothing to be returned(not
3826   **	  an error).  This could be because format is an empty string
3827   **    or it specifies %p that yields an empty string in some locale.
3828   ** If there is a better way to make it portable, go ahead by
3829   ** all means.
3830   */
3831   if ((len > 0 && len < buflen) || (len == 0 && *fmt == '\0'))
3832     return buf;
3833   else {
3834     /* Possibly buf overflowed - try again with a bigger buf */
3835     const int fmtlen = strlen(fmt);
3836     int bufsize = fmtlen + buflen;
3837 
3838     Renew(buf, bufsize, char);
3839     while (buf) {
3840 
3841       GCC_DIAG_IGNORE_STMT(-Wformat-nonliteral); /* fmt checked by caller */
3842       buflen = strftime(buf, bufsize, fmt, &mytm);
3843       GCC_DIAG_RESTORE_STMT;
3844 
3845       if (buflen > 0 && buflen < bufsize)
3846 	break;
3847       /* heuristic to prevent out-of-memory errors */
3848       if (bufsize > 100*fmtlen) {
3849 	Safefree(buf);
3850 	buf = NULL;
3851 	break;
3852       }
3853       bufsize *= 2;
3854       Renew(buf, bufsize, char);
3855     }
3856     return buf;
3857   }
3858 #else
3859   Perl_croak(aTHX_ "panic: no strftime");
3860   return NULL;
3861 #endif
3862 }
3863 
3864 
3865 #define SV_CWD_RETURN_UNDEF \
3866     sv_set_undef(sv); \
3867     return FALSE
3868 
3869 #define SV_CWD_ISDOT(dp) \
3870     (dp->d_name[0] == '.' && (dp->d_name[1] == '\0' || \
3871 	(dp->d_name[1] == '.' && dp->d_name[2] == '\0')))
3872 
3873 /*
3874 =head1 Miscellaneous Functions
3875 
3876 =for apidoc getcwd_sv
3877 
3878 Fill C<sv> with current working directory
3879 
3880 =cut
3881 */
3882 
3883 /* Originally written in Perl by John Bazik; rewritten in C by Ben Sugars.
3884  * rewritten again by dougm, optimized for use with xs TARG, and to prefer
3885  * getcwd(3) if available
3886  * Comments from the original:
3887  *     This is a faster version of getcwd.  It's also more dangerous
3888  *     because you might chdir out of a directory that you can't chdir
3889  *     back into. */
3890 
3891 int
3892 Perl_getcwd_sv(pTHX_ SV *sv)
3893 {
3894 #ifndef PERL_MICRO
3895     SvTAINTED_on(sv);
3896 
3897     PERL_ARGS_ASSERT_GETCWD_SV;
3898 
3899 #ifdef HAS_GETCWD
3900     {
3901 	char buf[MAXPATHLEN];
3902 
3903 	/* Some getcwd()s automatically allocate a buffer of the given
3904 	 * size from the heap if they are given a NULL buffer pointer.
3905 	 * The problem is that this behaviour is not portable. */
3906 	if (getcwd(buf, sizeof(buf) - 1)) {
3907 	    sv_setpv(sv, buf);
3908 	    return TRUE;
3909 	}
3910 	else {
3911 	    SV_CWD_RETURN_UNDEF;
3912 	}
3913     }
3914 
3915 #else
3916 
3917     Stat_t statbuf;
3918     int orig_cdev, orig_cino, cdev, cino, odev, oino, tdev, tino;
3919     int pathlen=0;
3920     Direntry_t *dp;
3921 
3922     SvUPGRADE(sv, SVt_PV);
3923 
3924     if (PerlLIO_lstat(".", &statbuf) < 0) {
3925 	SV_CWD_RETURN_UNDEF;
3926     }
3927 
3928     orig_cdev = statbuf.st_dev;
3929     orig_cino = statbuf.st_ino;
3930     cdev = orig_cdev;
3931     cino = orig_cino;
3932 
3933     for (;;) {
3934 	DIR *dir;
3935 	int namelen;
3936 	odev = cdev;
3937 	oino = cino;
3938 
3939 	if (PerlDir_chdir("..") < 0) {
3940 	    SV_CWD_RETURN_UNDEF;
3941 	}
3942 	if (PerlLIO_stat(".", &statbuf) < 0) {
3943 	    SV_CWD_RETURN_UNDEF;
3944 	}
3945 
3946 	cdev = statbuf.st_dev;
3947 	cino = statbuf.st_ino;
3948 
3949 	if (odev == cdev && oino == cino) {
3950 	    break;
3951 	}
3952 	if (!(dir = PerlDir_open("."))) {
3953 	    SV_CWD_RETURN_UNDEF;
3954 	}
3955 
3956 	while ((dp = PerlDir_read(dir)) != NULL) {
3957 #ifdef DIRNAMLEN
3958 	    namelen = dp->d_namlen;
3959 #else
3960 	    namelen = strlen(dp->d_name);
3961 #endif
3962 	    /* skip . and .. */
3963 	    if (SV_CWD_ISDOT(dp)) {
3964 		continue;
3965 	    }
3966 
3967 	    if (PerlLIO_lstat(dp->d_name, &statbuf) < 0) {
3968 		SV_CWD_RETURN_UNDEF;
3969 	    }
3970 
3971 	    tdev = statbuf.st_dev;
3972 	    tino = statbuf.st_ino;
3973 	    if (tino == oino && tdev == odev) {
3974 		break;
3975 	    }
3976 	}
3977 
3978 	if (!dp) {
3979 	    SV_CWD_RETURN_UNDEF;
3980 	}
3981 
3982 	if (pathlen + namelen + 1 >= MAXPATHLEN) {
3983 	    SV_CWD_RETURN_UNDEF;
3984 	}
3985 
3986 	SvGROW(sv, pathlen + namelen + 1);
3987 
3988 	if (pathlen) {
3989 	    /* shift down */
3990 	    Move(SvPVX_const(sv), SvPVX(sv) + namelen + 1, pathlen, char);
3991 	}
3992 
3993 	/* prepend current directory to the front */
3994 	*SvPVX(sv) = '/';
3995 	Move(dp->d_name, SvPVX(sv)+1, namelen, char);
3996 	pathlen += (namelen + 1);
3997 
3998 #ifdef VOID_CLOSEDIR
3999 	PerlDir_close(dir);
4000 #else
4001 	if (PerlDir_close(dir) < 0) {
4002 	    SV_CWD_RETURN_UNDEF;
4003 	}
4004 #endif
4005     }
4006 
4007     if (pathlen) {
4008 	SvCUR_set(sv, pathlen);
4009 	*SvEND(sv) = '\0';
4010 	SvPOK_only(sv);
4011 
4012 	if (PerlDir_chdir(SvPVX_const(sv)) < 0) {
4013 	    SV_CWD_RETURN_UNDEF;
4014 	}
4015     }
4016     if (PerlLIO_stat(".", &statbuf) < 0) {
4017 	SV_CWD_RETURN_UNDEF;
4018     }
4019 
4020     cdev = statbuf.st_dev;
4021     cino = statbuf.st_ino;
4022 
4023     if (cdev != orig_cdev || cino != orig_cino) {
4024 	Perl_croak(aTHX_ "Unstable directory path, "
4025 		   "current directory changed unexpectedly");
4026     }
4027 
4028     return TRUE;
4029 #endif
4030 
4031 #else
4032     return FALSE;
4033 #endif
4034 }
4035 
4036 #include "vutil.c"
4037 
4038 #if !defined(HAS_SOCKETPAIR) && defined(HAS_SOCKET) && defined(AF_INET) && defined(PF_INET) && defined(SOCK_DGRAM) && defined(HAS_SELECT)
4039 #   define EMULATE_SOCKETPAIR_UDP
4040 #endif
4041 
4042 #ifdef EMULATE_SOCKETPAIR_UDP
4043 static int
4044 S_socketpair_udp (int fd[2]) {
4045     dTHX;
4046     /* Fake a datagram socketpair using UDP to localhost.  */
4047     int sockets[2] = {-1, -1};
4048     struct sockaddr_in addresses[2];
4049     int i;
4050     Sock_size_t size = sizeof(struct sockaddr_in);
4051     unsigned short port;
4052     int got;
4053 
4054     memset(&addresses, 0, sizeof(addresses));
4055     i = 1;
4056     do {
4057 	sockets[i] = PerlSock_socket(AF_INET, SOCK_DGRAM, PF_INET);
4058 	if (sockets[i] == -1)
4059 	    goto tidy_up_and_fail;
4060 
4061 	addresses[i].sin_family = AF_INET;
4062 	addresses[i].sin_addr.s_addr = htonl(INADDR_LOOPBACK);
4063 	addresses[i].sin_port = 0;	/* kernel choses port.  */
4064 	if (PerlSock_bind(sockets[i], (struct sockaddr *) &addresses[i],
4065 		sizeof(struct sockaddr_in)) == -1)
4066 	    goto tidy_up_and_fail;
4067     } while (i--);
4068 
4069     /* Now have 2 UDP sockets. Find out which port each is connected to, and
4070        for each connect the other socket to it.  */
4071     i = 1;
4072     do {
4073 	if (PerlSock_getsockname(sockets[i], (struct sockaddr *) &addresses[i],
4074 		&size) == -1)
4075 	    goto tidy_up_and_fail;
4076 	if (size != sizeof(struct sockaddr_in))
4077 	    goto abort_tidy_up_and_fail;
4078 	/* !1 is 0, !0 is 1 */
4079 	if (PerlSock_connect(sockets[!i], (struct sockaddr *) &addresses[i],
4080 		sizeof(struct sockaddr_in)) == -1)
4081 	    goto tidy_up_and_fail;
4082     } while (i--);
4083 
4084     /* Now we have 2 sockets connected to each other. I don't trust some other
4085        process not to have already sent a packet to us (by random) so send
4086        a packet from each to the other.  */
4087     i = 1;
4088     do {
4089 	/* I'm going to send my own port number.  As a short.
4090 	   (Who knows if someone somewhere has sin_port as a bitfield and needs
4091 	   this routine. (I'm assuming crays have socketpair)) */
4092 	port = addresses[i].sin_port;
4093 	got = PerlLIO_write(sockets[i], &port, sizeof(port));
4094 	if (got != sizeof(port)) {
4095 	    if (got == -1)
4096 		goto tidy_up_and_fail;
4097 	    goto abort_tidy_up_and_fail;
4098 	}
4099     } while (i--);
4100 
4101     /* Packets sent. I don't trust them to have arrived though.
4102        (As I understand it Solaris TCP stack is multithreaded. Non-blocking
4103        connect to localhost will use a second kernel thread. In 2.6 the
4104        first thread running the connect() returns before the second completes,
4105        so EINPROGRESS> In 2.7 the improved stack is faster and connect()
4106        returns 0. Poor programs have tripped up. One poor program's authors'
4107        had a 50-1 reverse stock split. Not sure how connected these were.)
4108        So I don't trust someone not to have an unpredictable UDP stack.
4109     */
4110 
4111     {
4112 	struct timeval waitfor = {0, 100000}; /* You have 0.1 seconds */
4113 	int max = sockets[1] > sockets[0] ? sockets[1] : sockets[0];
4114 	fd_set rset;
4115 
4116 	FD_ZERO(&rset);
4117 	FD_SET((unsigned int)sockets[0], &rset);
4118 	FD_SET((unsigned int)sockets[1], &rset);
4119 
4120 	got = PerlSock_select(max + 1, &rset, NULL, NULL, &waitfor);
4121 	if (got != 2 || !FD_ISSET(sockets[0], &rset)
4122 		|| !FD_ISSET(sockets[1], &rset)) {
4123 	    /* I hope this is portable and appropriate.  */
4124 	    if (got == -1)
4125 		goto tidy_up_and_fail;
4126 	    goto abort_tidy_up_and_fail;
4127 	}
4128     }
4129 
4130     /* And the paranoia department even now doesn't trust it to have arrive
4131        (hence MSG_DONTWAIT). Or that what arrives was sent by us.  */
4132     {
4133 	struct sockaddr_in readfrom;
4134 	unsigned short buffer[2];
4135 
4136 	i = 1;
4137 	do {
4138 #ifdef MSG_DONTWAIT
4139 	    got = PerlSock_recvfrom(sockets[i], (char *) &buffer,
4140 		    sizeof(buffer), MSG_DONTWAIT,
4141 		    (struct sockaddr *) &readfrom, &size);
4142 #else
4143 	    got = PerlSock_recvfrom(sockets[i], (char *) &buffer,
4144 		    sizeof(buffer), 0,
4145 		    (struct sockaddr *) &readfrom, &size);
4146 #endif
4147 
4148 	    if (got == -1)
4149 		goto tidy_up_and_fail;
4150 	    if (got != sizeof(port)
4151 		    || size != sizeof(struct sockaddr_in)
4152 		    /* Check other socket sent us its port.  */
4153 		    || buffer[0] != (unsigned short) addresses[!i].sin_port
4154 		    /* Check kernel says we got the datagram from that socket */
4155 		    || readfrom.sin_family != addresses[!i].sin_family
4156 		    || readfrom.sin_addr.s_addr != addresses[!i].sin_addr.s_addr
4157 		    || readfrom.sin_port != addresses[!i].sin_port)
4158 		goto abort_tidy_up_and_fail;
4159 	} while (i--);
4160     }
4161     /* My caller (my_socketpair) has validated that this is non-NULL  */
4162     fd[0] = sockets[0];
4163     fd[1] = sockets[1];
4164     /* I hereby declare this connection open.  May God bless all who cross
4165        her.  */
4166     return 0;
4167 
4168   abort_tidy_up_and_fail:
4169     errno = ECONNABORTED;
4170   tidy_up_and_fail:
4171     {
4172 	dSAVE_ERRNO;
4173 	if (sockets[0] != -1)
4174 	    PerlLIO_close(sockets[0]);
4175 	if (sockets[1] != -1)
4176 	    PerlLIO_close(sockets[1]);
4177 	RESTORE_ERRNO;
4178 	return -1;
4179     }
4180 }
4181 #endif /*  EMULATE_SOCKETPAIR_UDP */
4182 
4183 #if !defined(HAS_SOCKETPAIR) && defined(HAS_SOCKET) && defined(AF_INET) && defined(PF_INET)
4184 int
4185 Perl_my_socketpair (int family, int type, int protocol, int fd[2]) {
4186     /* Stevens says that family must be AF_LOCAL, protocol 0.
4187        I'm going to enforce that, then ignore it, and use TCP (or UDP).  */
4188     dTHXa(NULL);
4189     int listener = -1;
4190     int connector = -1;
4191     int acceptor = -1;
4192     struct sockaddr_in listen_addr;
4193     struct sockaddr_in connect_addr;
4194     Sock_size_t size;
4195 
4196     if (protocol
4197 #ifdef AF_UNIX
4198 	|| family != AF_UNIX
4199 #endif
4200     ) {
4201 	errno = EAFNOSUPPORT;
4202 	return -1;
4203     }
4204     if (!fd) {
4205 	errno = EINVAL;
4206 	return -1;
4207     }
4208 
4209 #ifdef SOCK_CLOEXEC
4210     type &= ~SOCK_CLOEXEC;
4211 #endif
4212 
4213 #ifdef EMULATE_SOCKETPAIR_UDP
4214     if (type == SOCK_DGRAM)
4215 	return S_socketpair_udp(fd);
4216 #endif
4217 
4218     aTHXa(PERL_GET_THX);
4219     listener = PerlSock_socket(AF_INET, type, 0);
4220     if (listener == -1)
4221 	return -1;
4222     memset(&listen_addr, 0, sizeof(listen_addr));
4223     listen_addr.sin_family = AF_INET;
4224     listen_addr.sin_addr.s_addr = htonl(INADDR_LOOPBACK);
4225     listen_addr.sin_port = 0;	/* kernel choses port.  */
4226     if (PerlSock_bind(listener, (struct sockaddr *) &listen_addr,
4227 	    sizeof(listen_addr)) == -1)
4228 	goto tidy_up_and_fail;
4229     if (PerlSock_listen(listener, 1) == -1)
4230 	goto tidy_up_and_fail;
4231 
4232     connector = PerlSock_socket(AF_INET, type, 0);
4233     if (connector == -1)
4234 	goto tidy_up_and_fail;
4235     /* We want to find out the port number to connect to.  */
4236     size = sizeof(connect_addr);
4237     if (PerlSock_getsockname(listener, (struct sockaddr *) &connect_addr,
4238 	    &size) == -1)
4239 	goto tidy_up_and_fail;
4240     if (size != sizeof(connect_addr))
4241 	goto abort_tidy_up_and_fail;
4242     if (PerlSock_connect(connector, (struct sockaddr *) &connect_addr,
4243 	    sizeof(connect_addr)) == -1)
4244 	goto tidy_up_and_fail;
4245 
4246     size = sizeof(listen_addr);
4247     acceptor = PerlSock_accept(listener, (struct sockaddr *) &listen_addr,
4248 	    &size);
4249     if (acceptor == -1)
4250 	goto tidy_up_and_fail;
4251     if (size != sizeof(listen_addr))
4252 	goto abort_tidy_up_and_fail;
4253     PerlLIO_close(listener);
4254     /* Now check we are talking to ourself by matching port and host on the
4255        two sockets.  */
4256     if (PerlSock_getsockname(connector, (struct sockaddr *) &connect_addr,
4257 	    &size) == -1)
4258 	goto tidy_up_and_fail;
4259     if (size != sizeof(connect_addr)
4260 	    || listen_addr.sin_family != connect_addr.sin_family
4261 	    || listen_addr.sin_addr.s_addr != connect_addr.sin_addr.s_addr
4262 	    || listen_addr.sin_port != connect_addr.sin_port) {
4263 	goto abort_tidy_up_and_fail;
4264     }
4265     fd[0] = connector;
4266     fd[1] = acceptor;
4267     return 0;
4268 
4269   abort_tidy_up_and_fail:
4270 #ifdef ECONNABORTED
4271   errno = ECONNABORTED;	/* This would be the standard thing to do. */
4272 #elif defined(ECONNREFUSED)
4273   errno = ECONNREFUSED;	/* E.g. Symbian does not have ECONNABORTED. */
4274 #else
4275   errno = ETIMEDOUT;	/* Desperation time. */
4276 #endif
4277   tidy_up_and_fail:
4278     {
4279 	dSAVE_ERRNO;
4280 	if (listener != -1)
4281 	    PerlLIO_close(listener);
4282 	if (connector != -1)
4283 	    PerlLIO_close(connector);
4284 	if (acceptor != -1)
4285 	    PerlLIO_close(acceptor);
4286 	RESTORE_ERRNO;
4287 	return -1;
4288     }
4289 }
4290 #else
4291 /* In any case have a stub so that there's code corresponding
4292  * to the my_socketpair in embed.fnc. */
4293 int
4294 Perl_my_socketpair (int family, int type, int protocol, int fd[2]) {
4295 #ifdef HAS_SOCKETPAIR
4296     return socketpair(family, type, protocol, fd);
4297 #else
4298     return -1;
4299 #endif
4300 }
4301 #endif
4302 
4303 /*
4304 
4305 =for apidoc sv_nosharing
4306 
4307 Dummy routine which "shares" an SV when there is no sharing module present.
4308 Or "locks" it.  Or "unlocks" it.  In other
4309 words, ignores its single SV argument.
4310 Exists to avoid test for a C<NULL> function pointer and because it could
4311 potentially warn under some level of strict-ness.
4312 
4313 =cut
4314 */
4315 
4316 void
4317 Perl_sv_nosharing(pTHX_ SV *sv)
4318 {
4319     PERL_UNUSED_CONTEXT;
4320     PERL_UNUSED_ARG(sv);
4321 }
4322 
4323 /*
4324 
4325 =for apidoc sv_destroyable
4326 
4327 Dummy routine which reports that object can be destroyed when there is no
4328 sharing module present.  It ignores its single SV argument, and returns
4329 'true'.  Exists to avoid test for a C<NULL> function pointer and because it
4330 could potentially warn under some level of strict-ness.
4331 
4332 =cut
4333 */
4334 
4335 bool
4336 Perl_sv_destroyable(pTHX_ SV *sv)
4337 {
4338     PERL_UNUSED_CONTEXT;
4339     PERL_UNUSED_ARG(sv);
4340     return TRUE;
4341 }
4342 
4343 U32
4344 Perl_parse_unicode_opts(pTHX_ const char **popt)
4345 {
4346   const char *p = *popt;
4347   U32 opt = 0;
4348 
4349   PERL_ARGS_ASSERT_PARSE_UNICODE_OPTS;
4350 
4351   if (*p) {
4352        if (isDIGIT(*p)) {
4353             const char* endptr;
4354             UV uv;
4355             if (grok_atoUV(p, &uv, &endptr) && uv <= U32_MAX) {
4356                 opt = (U32)uv;
4357                 p = endptr;
4358                 if (p && *p && *p != '\n' && *p != '\r') {
4359                     if (isSPACE(*p))
4360                         goto the_end_of_the_opts_parser;
4361                     else
4362                         Perl_croak(aTHX_ "Unknown Unicode option letter '%c'", *p);
4363                 }
4364             }
4365             else {
4366                 Perl_croak(aTHX_ "Invalid number '%s' for -C option.\n", p);
4367             }
4368         }
4369         else {
4370 	    for (; *p; p++) {
4371 		 switch (*p) {
4372 		 case PERL_UNICODE_STDIN:
4373 		      opt |= PERL_UNICODE_STDIN_FLAG;	break;
4374 		 case PERL_UNICODE_STDOUT:
4375 		      opt |= PERL_UNICODE_STDOUT_FLAG;	break;
4376 		 case PERL_UNICODE_STDERR:
4377 		      opt |= PERL_UNICODE_STDERR_FLAG;	break;
4378 		 case PERL_UNICODE_STD:
4379 		      opt |= PERL_UNICODE_STD_FLAG;    	break;
4380 		 case PERL_UNICODE_IN:
4381 		      opt |= PERL_UNICODE_IN_FLAG;	break;
4382 		 case PERL_UNICODE_OUT:
4383 		      opt |= PERL_UNICODE_OUT_FLAG;	break;
4384 		 case PERL_UNICODE_INOUT:
4385 		      opt |= PERL_UNICODE_INOUT_FLAG;	break;
4386 		 case PERL_UNICODE_LOCALE:
4387 		      opt |= PERL_UNICODE_LOCALE_FLAG;	break;
4388 		 case PERL_UNICODE_ARGV:
4389 		      opt |= PERL_UNICODE_ARGV_FLAG;	break;
4390 		 case PERL_UNICODE_UTF8CACHEASSERT:
4391 		      opt |= PERL_UNICODE_UTF8CACHEASSERT_FLAG; break;
4392 		 default:
4393 		      if (*p != '\n' && *p != '\r') {
4394 			if(isSPACE(*p)) goto the_end_of_the_opts_parser;
4395 			else
4396 			  Perl_croak(aTHX_
4397 				     "Unknown Unicode option letter '%c'", *p);
4398 		      }
4399 		 }
4400 	    }
4401        }
4402   }
4403   else
4404        opt = PERL_UNICODE_DEFAULT_FLAGS;
4405 
4406   the_end_of_the_opts_parser:
4407 
4408   if (opt & ~PERL_UNICODE_ALL_FLAGS)
4409        Perl_croak(aTHX_ "Unknown Unicode option value %" UVuf,
4410 		  (UV) (opt & ~PERL_UNICODE_ALL_FLAGS));
4411 
4412   *popt = p;
4413 
4414   return opt;
4415 }
4416 
4417 #ifdef VMS
4418 #  include <starlet.h>
4419 #endif
4420 
4421 U32
4422 Perl_seed(pTHX)
4423 {
4424 #if defined(__OpenBSD__)
4425 	return arc4random();
4426 #else
4427     /*
4428      * This is really just a quick hack which grabs various garbage
4429      * values.  It really should be a real hash algorithm which
4430      * spreads the effect of every input bit onto every output bit,
4431      * if someone who knows about such things would bother to write it.
4432      * Might be a good idea to add that function to CORE as well.
4433      * No numbers below come from careful analysis or anything here,
4434      * except they are primes and SEED_C1 > 1E6 to get a full-width
4435      * value from (tv_sec * SEED_C1 + tv_usec).  The multipliers should
4436      * probably be bigger too.
4437      */
4438 #if RANDBITS > 16
4439 #  define SEED_C1	1000003
4440 #define   SEED_C4	73819
4441 #else
4442 #  define SEED_C1	25747
4443 #define   SEED_C4	20639
4444 #endif
4445 #define   SEED_C2	3
4446 #define   SEED_C3	269
4447 #define   SEED_C5	26107
4448 
4449 #ifndef PERL_NO_DEV_RANDOM
4450     int fd;
4451 #endif
4452     U32 u;
4453 #ifdef HAS_GETTIMEOFDAY
4454     struct timeval when;
4455 #else
4456     Time_t when;
4457 #endif
4458 
4459 /* This test is an escape hatch, this symbol isn't set by Configure. */
4460 #ifndef PERL_NO_DEV_RANDOM
4461 #ifndef PERL_RANDOM_DEVICE
4462    /* /dev/random isn't used by default because reads from it will block
4463     * if there isn't enough entropy available.  You can compile with
4464     * PERL_RANDOM_DEVICE to it if you'd prefer Perl to block until there
4465     * is enough real entropy to fill the seed. */
4466 #  ifdef __amigaos4__
4467 #    define PERL_RANDOM_DEVICE "RANDOM:SIZE=4"
4468 #  else
4469 #    define PERL_RANDOM_DEVICE "/dev/urandom"
4470 #  endif
4471 #endif
4472     fd = PerlLIO_open_cloexec(PERL_RANDOM_DEVICE, 0);
4473     if (fd != -1) {
4474     	if (PerlLIO_read(fd, (void*)&u, sizeof u) != sizeof u)
4475 	    u = 0;
4476 	PerlLIO_close(fd);
4477 	if (u)
4478 	    return u;
4479     }
4480 #endif
4481 
4482 #ifdef HAS_GETTIMEOFDAY
4483     PerlProc_gettimeofday(&when,NULL);
4484     u = (U32)SEED_C1 * when.tv_sec + (U32)SEED_C2 * when.tv_usec;
4485 #else
4486     (void)time(&when);
4487     u = (U32)SEED_C1 * when;
4488 #endif
4489     u += SEED_C3 * (U32)PerlProc_getpid();
4490     u += SEED_C4 * (U32)PTR2UV(PL_stack_sp);
4491 #ifndef PLAN9           /* XXX Plan9 assembler chokes on this; fix needed  */
4492     u += SEED_C5 * (U32)PTR2UV(&when);
4493 #endif
4494     return u;
4495 #endif
4496 }
4497 
4498 void
4499 Perl_get_hash_seed(pTHX_ unsigned char * const seed_buffer)
4500 {
4501 #ifndef NO_PERL_HASH_ENV
4502     const char *env_pv;
4503 #endif
4504     unsigned long i;
4505 
4506     PERL_ARGS_ASSERT_GET_HASH_SEED;
4507 
4508 #ifndef NO_PERL_HASH_ENV
4509     env_pv= PerlEnv_getenv("PERL_HASH_SEED");
4510 
4511     if ( env_pv )
4512     {
4513         /* ignore leading spaces */
4514         while (isSPACE(*env_pv))
4515             env_pv++;
4516 #    ifdef USE_PERL_PERTURB_KEYS
4517         /* if they set it to "0" we disable key traversal randomization completely */
4518         if (strEQ(env_pv,"0")) {
4519             PL_hash_rand_bits_enabled= 0;
4520         } else {
4521             /* otherwise switch to deterministic mode */
4522             PL_hash_rand_bits_enabled= 2;
4523         }
4524 #    endif
4525         /* ignore a leading 0x... if it is there */
4526         if (env_pv[0] == '0' && env_pv[1] == 'x')
4527             env_pv += 2;
4528 
4529         for( i = 0; isXDIGIT(*env_pv) && i < PERL_HASH_SEED_BYTES; i++ ) {
4530             seed_buffer[i] = READ_XDIGIT(env_pv) << 4;
4531             if ( isXDIGIT(*env_pv)) {
4532                 seed_buffer[i] |= READ_XDIGIT(env_pv);
4533             }
4534         }
4535         while (isSPACE(*env_pv))
4536             env_pv++;
4537 
4538         if (*env_pv && !isXDIGIT(*env_pv)) {
4539             Perl_warn(aTHX_ "perl: warning: Non hex character in '$ENV{PERL_HASH_SEED}', seed only partially set\n");
4540         }
4541         /* should we check for unparsed crap? */
4542         /* should we warn about unused hex? */
4543         /* should we warn about insufficient hex? */
4544     }
4545     else
4546 #endif /* NO_PERL_HASH_ENV */
4547     {
4548         for( i = 0; i < PERL_HASH_SEED_BYTES; i++ ) {
4549             seed_buffer[i] = (unsigned char)(Perl_internal_drand48() * (U8_MAX+1));
4550         }
4551     }
4552 #ifdef USE_PERL_PERTURB_KEYS
4553     {   /* initialize PL_hash_rand_bits from the hash seed.
4554          * This value is highly volatile, it is updated every
4555          * hash insert, and is used as part of hash bucket chain
4556          * randomization and hash iterator randomization. */
4557         PL_hash_rand_bits= 0xbe49d17f; /* I just picked a number */
4558         for( i = 0; i < sizeof(UV) ; i++ ) {
4559             PL_hash_rand_bits += seed_buffer[i % PERL_HASH_SEED_BYTES];
4560             PL_hash_rand_bits = ROTL_UV(PL_hash_rand_bits,8);
4561         }
4562     }
4563 #  ifndef NO_PERL_HASH_ENV
4564     env_pv= PerlEnv_getenv("PERL_PERTURB_KEYS");
4565     if (env_pv) {
4566         if (strEQ(env_pv,"0") || strEQ(env_pv,"NO")) {
4567             PL_hash_rand_bits_enabled= 0;
4568         } else if (strEQ(env_pv,"1") || strEQ(env_pv,"RANDOM")) {
4569             PL_hash_rand_bits_enabled= 1;
4570         } else if (strEQ(env_pv,"2") || strEQ(env_pv,"DETERMINISTIC")) {
4571             PL_hash_rand_bits_enabled= 2;
4572         } else {
4573             Perl_warn(aTHX_ "perl: warning: strange setting in '$ENV{PERL_PERTURB_KEYS}': '%s'\n", env_pv);
4574         }
4575     }
4576 #  endif
4577 #endif
4578 }
4579 
4580 #ifdef PERL_GLOBAL_STRUCT
4581 
4582 #define PERL_GLOBAL_STRUCT_INIT
4583 #include "opcode.h" /* the ppaddr and check */
4584 
4585 struct perl_vars *
4586 Perl_init_global_struct(pTHX)
4587 {
4588     struct perl_vars *plvarsp = NULL;
4589 # ifdef PERL_GLOBAL_STRUCT
4590     const IV nppaddr = C_ARRAY_LENGTH(Gppaddr);
4591     const IV ncheck  = C_ARRAY_LENGTH(Gcheck);
4592     PERL_UNUSED_CONTEXT;
4593 #  ifdef PERL_GLOBAL_STRUCT_PRIVATE
4594     /* PerlMem_malloc() because can't use even safesysmalloc() this early. */
4595     plvarsp = (struct perl_vars*)PerlMem_malloc(sizeof(struct perl_vars));
4596     if (!plvarsp)
4597         exit(1);
4598 #  else
4599     plvarsp = PL_VarsPtr;
4600 #  endif /* PERL_GLOBAL_STRUCT_PRIVATE */
4601 #  undef PERLVAR
4602 #  undef PERLVARA
4603 #  undef PERLVARI
4604 #  undef PERLVARIC
4605 #  define PERLVAR(prefix,var,type) /**/
4606 #  define PERLVARA(prefix,var,n,type) /**/
4607 #  define PERLVARI(prefix,var,type,init) plvarsp->prefix##var = init;
4608 #  define PERLVARIC(prefix,var,type,init) plvarsp->prefix##var = init;
4609 #  include "perlvars.h"
4610 #  undef PERLVAR
4611 #  undef PERLVARA
4612 #  undef PERLVARI
4613 #  undef PERLVARIC
4614 #  ifdef PERL_GLOBAL_STRUCT
4615     plvarsp->Gppaddr =
4616 	(Perl_ppaddr_t*)
4617 	PerlMem_malloc(nppaddr * sizeof(Perl_ppaddr_t));
4618     if (!plvarsp->Gppaddr)
4619         exit(1);
4620     plvarsp->Gcheck  =
4621 	(Perl_check_t*)
4622 	PerlMem_malloc(ncheck  * sizeof(Perl_check_t));
4623     if (!plvarsp->Gcheck)
4624         exit(1);
4625     Copy(Gppaddr, plvarsp->Gppaddr, nppaddr, Perl_ppaddr_t);
4626     Copy(Gcheck,  plvarsp->Gcheck,  ncheck,  Perl_check_t);
4627 #  endif
4628 #  ifdef PERL_SET_VARS
4629     PERL_SET_VARS(plvarsp);
4630 #  endif
4631 #  ifdef PERL_GLOBAL_STRUCT_PRIVATE
4632     plvarsp->Gsv_placeholder.sv_flags = 0;
4633     memset(plvarsp->Ghash_seed, 0, sizeof(plvarsp->Ghash_seed));
4634 #  endif
4635 # undef PERL_GLOBAL_STRUCT_INIT
4636 # endif
4637     return plvarsp;
4638 }
4639 
4640 #endif /* PERL_GLOBAL_STRUCT */
4641 
4642 #ifdef PERL_GLOBAL_STRUCT
4643 
4644 void
4645 Perl_free_global_struct(pTHX_ struct perl_vars *plvarsp)
4646 {
4647     int veto = plvarsp->Gveto_cleanup;
4648 
4649     PERL_ARGS_ASSERT_FREE_GLOBAL_STRUCT;
4650     PERL_UNUSED_CONTEXT;
4651 # ifdef PERL_GLOBAL_STRUCT
4652 #  ifdef PERL_UNSET_VARS
4653     PERL_UNSET_VARS(plvarsp);
4654 #  endif
4655     if (veto)
4656         return;
4657     free(plvarsp->Gppaddr);
4658     free(plvarsp->Gcheck);
4659 #  ifdef PERL_GLOBAL_STRUCT_PRIVATE
4660     free(plvarsp);
4661 #  endif
4662 # endif
4663 }
4664 
4665 #endif /* PERL_GLOBAL_STRUCT */
4666 
4667 #ifdef PERL_MEM_LOG
4668 
4669 /* -DPERL_MEM_LOG: the Perl_mem_log_..() is compiled, including
4670  * the default implementation, unless -DPERL_MEM_LOG_NOIMPL is also
4671  * given, and you supply your own implementation.
4672  *
4673  * The default implementation reads a single env var, PERL_MEM_LOG,
4674  * expecting one or more of the following:
4675  *
4676  *    \d+ - fd		fd to write to		: must be 1st (grok_atoUV)
4677  *    'm' - memlog	was PERL_MEM_LOG=1
4678  *    's' - svlog	was PERL_SV_LOG=1
4679  *    't' - timestamp	was PERL_MEM_LOG_TIMESTAMP=1
4680  *
4681  * This makes the logger controllable enough that it can reasonably be
4682  * added to the system perl.
4683  */
4684 
4685 /* -DPERL_MEM_LOG_SPRINTF_BUF_SIZE=X: size of a (stack-allocated) buffer
4686  * the Perl_mem_log_...() will use (either via sprintf or snprintf).
4687  */
4688 #define PERL_MEM_LOG_SPRINTF_BUF_SIZE 128
4689 
4690 /* -DPERL_MEM_LOG_FD=N: the file descriptor the Perl_mem_log_...()
4691  * writes to.  In the default logger, this is settable at runtime.
4692  */
4693 #ifndef PERL_MEM_LOG_FD
4694 #  define PERL_MEM_LOG_FD 2 /* If STDERR is too boring for you. */
4695 #endif
4696 
4697 #ifndef PERL_MEM_LOG_NOIMPL
4698 
4699 # ifdef DEBUG_LEAKING_SCALARS
4700 #   define SV_LOG_SERIAL_FMT	    " [%lu]"
4701 #   define _SV_LOG_SERIAL_ARG(sv)   , (unsigned long) (sv)->sv_debug_serial
4702 # else
4703 #   define SV_LOG_SERIAL_FMT
4704 #   define _SV_LOG_SERIAL_ARG(sv)
4705 # endif
4706 
4707 static void
4708 S_mem_log_common(enum mem_log_type mlt, const UV n,
4709 		 const UV typesize, const char *type_name, const SV *sv,
4710 		 Malloc_t oldalloc, Malloc_t newalloc,
4711 		 const char *filename, const int linenumber,
4712 		 const char *funcname)
4713 {
4714     const char *pmlenv;
4715 
4716     PERL_ARGS_ASSERT_MEM_LOG_COMMON;
4717 
4718     pmlenv = PerlEnv_getenv("PERL_MEM_LOG");
4719     if (!pmlenv)
4720 	return;
4721     if (mlt < MLT_NEW_SV ? strchr(pmlenv,'m') : strchr(pmlenv,'s'))
4722     {
4723 	/* We can't use SVs or PerlIO for obvious reasons,
4724 	 * so we'll use stdio and low-level IO instead. */
4725 	char buf[PERL_MEM_LOG_SPRINTF_BUF_SIZE];
4726 
4727 #   ifdef HAS_GETTIMEOFDAY
4728 #     define MEM_LOG_TIME_FMT	"%10d.%06d: "
4729 #     define MEM_LOG_TIME_ARG	(int)tv.tv_sec, (int)tv.tv_usec
4730 	struct timeval tv;
4731 	gettimeofday(&tv, 0);
4732 #   else
4733 #     define MEM_LOG_TIME_FMT	"%10d: "
4734 #     define MEM_LOG_TIME_ARG	(int)when
4735         Time_t when;
4736         (void)time(&when);
4737 #   endif
4738 	/* If there are other OS specific ways of hires time than
4739 	 * gettimeofday() (see dist/Time-HiRes), the easiest way is
4740 	 * probably that they would be used to fill in the struct
4741 	 * timeval. */
4742 	{
4743 	    STRLEN len;
4744             const char* endptr;
4745 	    int fd;
4746             UV uv;
4747             if (grok_atoUV(pmlenv, &uv, &endptr) /* Ignore endptr. */
4748                 && uv && uv <= PERL_INT_MAX
4749             ) {
4750                 fd = (int)uv;
4751             } else {
4752 		fd = PERL_MEM_LOG_FD;
4753             }
4754 
4755 	    if (strchr(pmlenv, 't')) {
4756 		len = my_snprintf(buf, sizeof(buf),
4757 				MEM_LOG_TIME_FMT, MEM_LOG_TIME_ARG);
4758 		PERL_UNUSED_RESULT(PerlLIO_write(fd, buf, len));
4759 	    }
4760 	    switch (mlt) {
4761 	    case MLT_ALLOC:
4762 		len = my_snprintf(buf, sizeof(buf),
4763 			"alloc: %s:%d:%s: %" IVdf " %" UVuf
4764 			" %s = %" IVdf ": %" UVxf "\n",
4765 			filename, linenumber, funcname, n, typesize,
4766 			type_name, n * typesize, PTR2UV(newalloc));
4767 		break;
4768 	    case MLT_REALLOC:
4769 		len = my_snprintf(buf, sizeof(buf),
4770 			"realloc: %s:%d:%s: %" IVdf " %" UVuf
4771 			" %s = %" IVdf ": %" UVxf " -> %" UVxf "\n",
4772 			filename, linenumber, funcname, n, typesize,
4773 			type_name, n * typesize, PTR2UV(oldalloc),
4774 			PTR2UV(newalloc));
4775 		break;
4776 	    case MLT_FREE:
4777 		len = my_snprintf(buf, sizeof(buf),
4778 			"free: %s:%d:%s: %" UVxf "\n",
4779 			filename, linenumber, funcname,
4780 			PTR2UV(oldalloc));
4781 		break;
4782 	    case MLT_NEW_SV:
4783 	    case MLT_DEL_SV:
4784 		len = my_snprintf(buf, sizeof(buf),
4785 			"%s_SV: %s:%d:%s: %" UVxf SV_LOG_SERIAL_FMT "\n",
4786 			mlt == MLT_NEW_SV ? "new" : "del",
4787 			filename, linenumber, funcname,
4788 			PTR2UV(sv) _SV_LOG_SERIAL_ARG(sv));
4789 		break;
4790 	    default:
4791 		len = 0;
4792 	    }
4793 	    PERL_UNUSED_RESULT(PerlLIO_write(fd, buf, len));
4794 	}
4795     }
4796 }
4797 #endif /* !PERL_MEM_LOG_NOIMPL */
4798 
4799 #ifndef PERL_MEM_LOG_NOIMPL
4800 # define \
4801     mem_log_common_if(alty, num, tysz, tynm, sv, oal, nal, flnm, ln, fnnm) \
4802     mem_log_common   (alty, num, tysz, tynm, sv, oal, nal, flnm, ln, fnnm)
4803 #else
4804 /* this is suboptimal, but bug compatible.  User is providing their
4805    own implementation, but is getting these functions anyway, and they
4806    do nothing. But _NOIMPL users should be able to cope or fix */
4807 # define \
4808     mem_log_common_if(alty, num, tysz, tynm, u, oal, nal, flnm, ln, fnnm) \
4809     /* mem_log_common_if_PERL_MEM_LOG_NOIMPL */
4810 #endif
4811 
4812 Malloc_t
4813 Perl_mem_log_alloc(const UV n, const UV typesize, const char *type_name,
4814 		   Malloc_t newalloc,
4815 		   const char *filename, const int linenumber,
4816 		   const char *funcname)
4817 {
4818     PERL_ARGS_ASSERT_MEM_LOG_ALLOC;
4819 
4820     mem_log_common_if(MLT_ALLOC, n, typesize, type_name,
4821 		      NULL, NULL, newalloc,
4822 		      filename, linenumber, funcname);
4823     return newalloc;
4824 }
4825 
4826 Malloc_t
4827 Perl_mem_log_realloc(const UV n, const UV typesize, const char *type_name,
4828 		     Malloc_t oldalloc, Malloc_t newalloc,
4829 		     const char *filename, const int linenumber,
4830 		     const char *funcname)
4831 {
4832     PERL_ARGS_ASSERT_MEM_LOG_REALLOC;
4833 
4834     mem_log_common_if(MLT_REALLOC, n, typesize, type_name,
4835 		      NULL, oldalloc, newalloc,
4836 		      filename, linenumber, funcname);
4837     return newalloc;
4838 }
4839 
4840 Malloc_t
4841 Perl_mem_log_free(Malloc_t oldalloc,
4842 		  const char *filename, const int linenumber,
4843 		  const char *funcname)
4844 {
4845     PERL_ARGS_ASSERT_MEM_LOG_FREE;
4846 
4847     mem_log_common_if(MLT_FREE, 0, 0, "", NULL, oldalloc, NULL,
4848 		      filename, linenumber, funcname);
4849     return oldalloc;
4850 }
4851 
4852 void
4853 Perl_mem_log_new_sv(const SV *sv,
4854 		    const char *filename, const int linenumber,
4855 		    const char *funcname)
4856 {
4857     mem_log_common_if(MLT_NEW_SV, 0, 0, "", sv, NULL, NULL,
4858 		      filename, linenumber, funcname);
4859 }
4860 
4861 void
4862 Perl_mem_log_del_sv(const SV *sv,
4863 		    const char *filename, const int linenumber,
4864 		    const char *funcname)
4865 {
4866     mem_log_common_if(MLT_DEL_SV, 0, 0, "", sv, NULL, NULL,
4867 		      filename, linenumber, funcname);
4868 }
4869 
4870 #endif /* PERL_MEM_LOG */
4871 
4872 /*
4873 =for apidoc quadmath_format_single
4874 
4875 C<quadmath_snprintf()> is very strict about its C<format> string and will
4876 fail, returning -1, if the format is invalid.  It accepts exactly
4877 one format spec.
4878 
4879 C<quadmath_format_single()> checks that the intended single spec looks
4880 sane: begins with C<%>, has only one C<%>, ends with C<[efgaEFGA]>,
4881 and has C<Q> before it.  This is not a full "printf syntax check",
4882 just the basics.
4883 
4884 Returns the format if it is valid, NULL if not.
4885 
4886 C<quadmath_format_single()> can and will actually patch in the missing
4887 C<Q>, if necessary.  In this case it will return the modified copy of
4888 the format, B<which the caller will need to free.>
4889 
4890 See also L</quadmath_format_needed>.
4891 
4892 =cut
4893 */
4894 #ifdef USE_QUADMATH
4895 const char*
4896 Perl_quadmath_format_single(const char* format)
4897 {
4898     STRLEN len;
4899 
4900     PERL_ARGS_ASSERT_QUADMATH_FORMAT_SINGLE;
4901 
4902     if (format[0] != '%' || strchr(format + 1, '%'))
4903         return NULL;
4904     len = strlen(format);
4905     /* minimum length three: %Qg */
4906     if (len < 3 || strchr("efgaEFGA", format[len - 1]) == NULL)
4907         return NULL;
4908     if (format[len - 2] != 'Q') {
4909         char* fixed;
4910         Newx(fixed, len + 1, char);
4911         memcpy(fixed, format, len - 1);
4912         fixed[len - 1] = 'Q';
4913         fixed[len    ] = format[len - 1];
4914         fixed[len + 1] = 0;
4915         return (const char*)fixed;
4916     }
4917     return format;
4918 }
4919 #endif
4920 
4921 /*
4922 =for apidoc quadmath_format_needed
4923 
4924 C<quadmath_format_needed()> returns true if the C<format> string seems to
4925 contain at least one non-Q-prefixed C<%[efgaEFGA]> format specifier,
4926 or returns false otherwise.
4927 
4928 The format specifier detection is not complete printf-syntax detection,
4929 but it should catch most common cases.
4930 
4931 If true is returned, those arguments B<should> in theory be processed
4932 with C<quadmath_snprintf()>, but in case there is more than one such
4933 format specifier (see L</quadmath_format_single>), and if there is
4934 anything else beyond that one (even just a single byte), they
4935 B<cannot> be processed because C<quadmath_snprintf()> is very strict,
4936 accepting only one format spec, and nothing else.
4937 In this case, the code should probably fail.
4938 
4939 =cut
4940 */
4941 #ifdef USE_QUADMATH
4942 bool
4943 Perl_quadmath_format_needed(const char* format)
4944 {
4945   const char *p = format;
4946   const char *q;
4947 
4948   PERL_ARGS_ASSERT_QUADMATH_FORMAT_NEEDED;
4949 
4950   while ((q = strchr(p, '%'))) {
4951     q++;
4952     if (*q == '+') /* plus */
4953       q++;
4954     if (*q == '#') /* alt */
4955       q++;
4956     if (*q == '*') /* width */
4957       q++;
4958     else {
4959       if (isDIGIT(*q)) {
4960         while (isDIGIT(*q)) q++;
4961       }
4962     }
4963     if (*q == '.' && (q[1] == '*' || isDIGIT(q[1]))) { /* prec */
4964       q++;
4965       if (*q == '*')
4966         q++;
4967       else
4968         while (isDIGIT(*q)) q++;
4969     }
4970     if (strchr("efgaEFGA", *q)) /* Would have needed 'Q' in front. */
4971       return TRUE;
4972     p = q + 1;
4973   }
4974   return FALSE;
4975 }
4976 #endif
4977 
4978 /*
4979 =for apidoc my_snprintf
4980 
4981 The C library C<snprintf> functionality, if available and
4982 standards-compliant (uses C<vsnprintf>, actually).  However, if the
4983 C<vsnprintf> is not available, will unfortunately use the unsafe
4984 C<vsprintf> which can overrun the buffer (there is an overrun check,
4985 but that may be too late).  Consider using C<sv_vcatpvf> instead, or
4986 getting C<vsnprintf>.
4987 
4988 =cut
4989 */
4990 int
4991 Perl_my_snprintf(char *buffer, const Size_t len, const char *format, ...)
4992 {
4993     int retval = -1;
4994     va_list ap;
4995     PERL_ARGS_ASSERT_MY_SNPRINTF;
4996 #ifndef HAS_VSNPRINTF
4997     PERL_UNUSED_VAR(len);
4998 #endif
4999     va_start(ap, format);
5000 #ifdef USE_QUADMATH
5001     {
5002         const char* qfmt = quadmath_format_single(format);
5003         bool quadmath_valid = FALSE;
5004         if (qfmt) {
5005             /* If the format looked promising, use it as quadmath. */
5006             retval = quadmath_snprintf(buffer, len, qfmt, va_arg(ap, NV));
5007             if (retval == -1) {
5008                 if (qfmt != format) {
5009                     dTHX;
5010                     SAVEFREEPV(qfmt);
5011                 }
5012                 Perl_croak_nocontext("panic: quadmath_snprintf failed, format \"%s\"", qfmt);
5013             }
5014             quadmath_valid = TRUE;
5015             if (qfmt != format)
5016                 Safefree(qfmt);
5017             qfmt = NULL;
5018         }
5019         assert(qfmt == NULL);
5020         /* quadmath_format_single() will return false for example for
5021          * "foo = %g", or simply "%g".  We could handle the %g by
5022          * using quadmath for the NV args.  More complex cases of
5023          * course exist: "foo = %g, bar = %g", or "foo=%Qg" (otherwise
5024          * quadmath-valid but has stuff in front).
5025          *
5026          * Handling the "Q-less" cases right would require walking
5027          * through the va_list and rewriting the format, calling
5028          * quadmath for the NVs, building a new va_list, and then
5029          * letting vsnprintf/vsprintf to take care of the other
5030          * arguments.  This may be doable.
5031          *
5032          * We do not attempt that now.  But for paranoia, we here try
5033          * to detect some common (but not all) cases where the
5034          * "Q-less" %[efgaEFGA] formats are present, and die if
5035          * detected.  This doesn't fix the problem, but it stops the
5036          * vsnprintf/vsprintf pulling doubles off the va_list when
5037          * __float128 NVs should be pulled off instead.
5038          *
5039          * If quadmath_format_needed() returns false, we are reasonably
5040          * certain that we can call vnsprintf() or vsprintf() safely. */
5041         if (!quadmath_valid && quadmath_format_needed(format))
5042           Perl_croak_nocontext("panic: quadmath_snprintf failed, format \"%s\"", format);
5043 
5044     }
5045 #endif
5046     if (retval == -1)
5047 #ifdef HAS_VSNPRINTF
5048         retval = vsnprintf(buffer, len, format, ap);
5049 #else
5050         retval = vsprintf(buffer, format, ap);
5051 #endif
5052     va_end(ap);
5053     /* vsprintf() shows failure with < 0 */
5054     if (retval < 0
5055 #ifdef HAS_VSNPRINTF
5056     /* vsnprintf() shows failure with >= len */
5057         ||
5058         (len > 0 && (Size_t)retval >= len)
5059 #endif
5060     )
5061 	Perl_croak_nocontext("panic: my_snprintf buffer overflow");
5062     return retval;
5063 }
5064 
5065 /*
5066 =for apidoc my_vsnprintf
5067 
5068 The C library C<vsnprintf> if available and standards-compliant.
5069 However, if if the C<vsnprintf> is not available, will unfortunately
5070 use the unsafe C<vsprintf> which can overrun the buffer (there is an
5071 overrun check, but that may be too late).  Consider using
5072 C<sv_vcatpvf> instead, or getting C<vsnprintf>.
5073 
5074 =cut
5075 */
5076 int
5077 Perl_my_vsnprintf(char *buffer, const Size_t len, const char *format, va_list ap)
5078 {
5079 #ifdef USE_QUADMATH
5080     PERL_UNUSED_ARG(buffer);
5081     PERL_UNUSED_ARG(len);
5082     PERL_UNUSED_ARG(format);
5083     /* the cast is to avoid gcc -Wsizeof-array-argument complaining */
5084     PERL_UNUSED_ARG((void*)ap);
5085     Perl_croak_nocontext("panic: my_vsnprintf not available with quadmath");
5086     return 0;
5087 #else
5088     int retval;
5089 #ifdef NEED_VA_COPY
5090     va_list apc;
5091 
5092     PERL_ARGS_ASSERT_MY_VSNPRINTF;
5093     Perl_va_copy(ap, apc);
5094 # ifdef HAS_VSNPRINTF
5095     retval = vsnprintf(buffer, len, format, apc);
5096 # else
5097     PERL_UNUSED_ARG(len);
5098     retval = vsprintf(buffer, format, apc);
5099 # endif
5100     va_end(apc);
5101 #else
5102 # ifdef HAS_VSNPRINTF
5103     retval = vsnprintf(buffer, len, format, ap);
5104 # else
5105     PERL_UNUSED_ARG(len);
5106     retval = vsprintf(buffer, format, ap);
5107 # endif
5108 #endif /* #ifdef NEED_VA_COPY */
5109     /* vsprintf() shows failure with < 0 */
5110     if (retval < 0
5111 #ifdef HAS_VSNPRINTF
5112     /* vsnprintf() shows failure with >= len */
5113         ||
5114         (len > 0 && (Size_t)retval >= len)
5115 #endif
5116     )
5117 	Perl_croak_nocontext("panic: my_vsnprintf buffer overflow");
5118     return retval;
5119 #endif
5120 }
5121 
5122 void
5123 Perl_my_clearenv(pTHX)
5124 {
5125     dVAR;
5126 #if ! defined(PERL_MICRO)
5127 #  if defined(PERL_IMPLICIT_SYS) || defined(WIN32)
5128     PerlEnv_clearenv();
5129 #  else /* ! (PERL_IMPLICIT_SYS || WIN32) */
5130 #    if defined(USE_ENVIRON_ARRAY)
5131 #      if defined(USE_ITHREADS)
5132     /* only the parent thread can clobber the process environment */
5133     if (PL_curinterp == aTHX)
5134 #      endif /* USE_ITHREADS */
5135     {
5136 #      if ! defined(PERL_USE_SAFE_PUTENV)
5137     if ( !PL_use_safe_putenv) {
5138       I32 i;
5139       if (environ == PL_origenviron)
5140         environ = (char**)safesysmalloc(sizeof(char*));
5141       else
5142         for (i = 0; environ[i]; i++)
5143           (void)safesysfree(environ[i]);
5144     }
5145     environ[0] = NULL;
5146 #      else /* PERL_USE_SAFE_PUTENV */
5147 #        if defined(HAS_CLEARENV)
5148     (void)clearenv();
5149 #        elif defined(HAS_UNSETENV)
5150     int bsiz = 80; /* Most envvar names will be shorter than this. */
5151     char *buf = (char*)safesysmalloc(bsiz);
5152     while (*environ != NULL) {
5153       char *e = strchr(*environ, '=');
5154       int l = e ? e - *environ : (int)strlen(*environ);
5155       if (bsiz < l + 1) {
5156         (void)safesysfree(buf);
5157         bsiz = l + 1; /* + 1 for the \0. */
5158         buf = (char*)safesysmalloc(bsiz);
5159       }
5160       memcpy(buf, *environ, l);
5161       buf[l] = '\0';
5162       (void)unsetenv(buf);
5163     }
5164     (void)safesysfree(buf);
5165 #        else /* ! HAS_CLEARENV && ! HAS_UNSETENV */
5166     /* Just null environ and accept the leakage. */
5167     *environ = NULL;
5168 #        endif /* HAS_CLEARENV || HAS_UNSETENV */
5169 #      endif /* ! PERL_USE_SAFE_PUTENV */
5170     }
5171 #    endif /* USE_ENVIRON_ARRAY */
5172 #  endif /* PERL_IMPLICIT_SYS || WIN32 */
5173 #endif /* PERL_MICRO */
5174 }
5175 
5176 #ifdef PERL_IMPLICIT_CONTEXT
5177 
5178 /* Implements the MY_CXT_INIT macro. The first time a module is loaded,
5179 the global PL_my_cxt_index is incremented, and that value is assigned to
5180 that module's static my_cxt_index (who's address is passed as an arg).
5181 Then, for each interpreter this function is called for, it makes sure a
5182 void* slot is available to hang the static data off, by allocating or
5183 extending the interpreter's PL_my_cxt_list array */
5184 
5185 #ifndef PERL_GLOBAL_STRUCT_PRIVATE
5186 void *
5187 Perl_my_cxt_init(pTHX_ int *index, size_t size)
5188 {
5189     dVAR;
5190     void *p;
5191     PERL_ARGS_ASSERT_MY_CXT_INIT;
5192     if (*index == -1) {
5193 	/* this module hasn't been allocated an index yet */
5194 	MUTEX_LOCK(&PL_my_ctx_mutex);
5195 	*index = PL_my_cxt_index++;
5196 	MUTEX_UNLOCK(&PL_my_ctx_mutex);
5197     }
5198 
5199     /* make sure the array is big enough */
5200     if (PL_my_cxt_size <= *index) {
5201 	if (PL_my_cxt_size) {
5202             IV new_size = PL_my_cxt_size;
5203 	    while (new_size <= *index)
5204 		new_size *= 2;
5205 	    Renew(PL_my_cxt_list, new_size, void *);
5206             PL_my_cxt_size = new_size;
5207 	}
5208 	else {
5209 	    PL_my_cxt_size = 16;
5210 	    Newx(PL_my_cxt_list, PL_my_cxt_size, void *);
5211 	}
5212     }
5213     /* newSV() allocates one more than needed */
5214     p = (void*)SvPVX(newSV(size-1));
5215     PL_my_cxt_list[*index] = p;
5216     Zero(p, size, char);
5217     return p;
5218 }
5219 
5220 #else /* #ifndef PERL_GLOBAL_STRUCT_PRIVATE */
5221 
5222 int
5223 Perl_my_cxt_index(pTHX_ const char *my_cxt_key)
5224 {
5225     dVAR;
5226     int index;
5227 
5228     PERL_ARGS_ASSERT_MY_CXT_INDEX;
5229 
5230     for (index = 0; index < PL_my_cxt_index; index++) {
5231 	const char *key = PL_my_cxt_keys[index];
5232 	/* try direct pointer compare first - there are chances to success,
5233 	 * and it's much faster.
5234 	 */
5235 	if ((key == my_cxt_key) || strEQ(key, my_cxt_key))
5236 	    return index;
5237     }
5238     return -1;
5239 }
5240 
5241 void *
5242 Perl_my_cxt_init(pTHX_ const char *my_cxt_key, size_t size)
5243 {
5244     dVAR;
5245     void *p;
5246     int index;
5247 
5248     PERL_ARGS_ASSERT_MY_CXT_INIT;
5249 
5250     index = Perl_my_cxt_index(aTHX_ my_cxt_key);
5251     if (index == -1) {
5252 	/* this module hasn't been allocated an index yet */
5253 	MUTEX_LOCK(&PL_my_ctx_mutex);
5254 	index = PL_my_cxt_index++;
5255 	MUTEX_UNLOCK(&PL_my_ctx_mutex);
5256     }
5257 
5258     /* make sure the array is big enough */
5259     if (PL_my_cxt_size <= index) {
5260 	int old_size = PL_my_cxt_size;
5261 	int i;
5262 	if (PL_my_cxt_size) {
5263             IV new_size = PL_my_cxt_size;
5264 	    while (new_size <= index)
5265 		new_size *= 2;
5266 	    Renew(PL_my_cxt_list, new_size, void *);
5267 	    Renew(PL_my_cxt_keys, new_size, const char *);
5268             PL_my_cxt_size = new_size;
5269 	}
5270 	else {
5271 	    PL_my_cxt_size = 16;
5272 	    Newx(PL_my_cxt_list, PL_my_cxt_size, void *);
5273 	    Newx(PL_my_cxt_keys, PL_my_cxt_size, const char *);
5274 	}
5275 	for (i = old_size; i < PL_my_cxt_size; i++) {
5276 	    PL_my_cxt_keys[i] = 0;
5277 	    PL_my_cxt_list[i] = 0;
5278 	}
5279     }
5280     PL_my_cxt_keys[index] = my_cxt_key;
5281     /* newSV() allocates one more than needed */
5282     p = (void*)SvPVX(newSV(size-1));
5283     PL_my_cxt_list[index] = p;
5284     Zero(p, size, char);
5285     return p;
5286 }
5287 #endif /* #ifndef PERL_GLOBAL_STRUCT_PRIVATE */
5288 #endif /* PERL_IMPLICIT_CONTEXT */
5289 
5290 
5291 /* Perl_xs_handshake():
5292    implement the various XS_*_BOOTCHECK macros, which are added to .c
5293    files by ExtUtils::ParseXS, to check that the perl the module was built
5294    with is binary compatible with the running perl.
5295 
5296    usage:
5297        Perl_xs_handshake(U32 key, void * v_my_perl, const char * file,
5298             [U32 items, U32 ax], [char * api_version], [char * xs_version])
5299 
5300    The meaning of the varargs is determined the U32 key arg (which is not
5301    a format string). The fields of key are assembled by using HS_KEY().
5302 
5303    Under PERL_IMPLICIT_CONTEX, the v_my_perl arg is of type
5304    "PerlInterpreter *" and represents the callers context; otherwise it is
5305    of type "CV *", and is the boot xsub's CV.
5306 
5307    v_my_perl will catch where a threaded future perl526.dll calling IO.dll
5308    for example, and IO.dll was linked with threaded perl524.dll, and both
5309    perl526.dll and perl524.dll are in %PATH and the Win32 DLL loader
5310    successfully can load IO.dll into the process but simultaneously it
5311    loaded an interpreter of a different version into the process, and XS
5312    code will naturally pass SV*s created by perl524.dll for perl526.dll to
5313    use through perl526.dll's my_perl->Istack_base.
5314 
5315    v_my_perl cannot be the first arg, since then 'key' will be out of
5316    place in a threaded vs non-threaded mixup; and analyzing the key
5317    number's bitfields won't reveal the problem, since it will be a valid
5318    key (unthreaded perl) on interp side, but croak will report the XS mod's
5319    key as gibberish (it is really a my_perl ptr) (threaded XS mod); or if
5320    it's a threaded perl and an unthreaded XS module, threaded perl will
5321    look at an uninit C stack or an uninit register to get 'key'
5322    (remember that it assumes that the 1st arg is the interp cxt).
5323 
5324    'file' is the source filename of the caller.
5325 */
5326 
5327 I32
5328 Perl_xs_handshake(const U32 key, void * v_my_perl, const char * file, ...)
5329 {
5330     va_list args;
5331     U32 items, ax;
5332     void * got;
5333     void * need;
5334 #ifdef PERL_IMPLICIT_CONTEXT
5335     dTHX;
5336     tTHX xs_interp;
5337 #else
5338     CV* cv;
5339     SV *** xs_spp;
5340 #endif
5341     PERL_ARGS_ASSERT_XS_HANDSHAKE;
5342     va_start(args, file);
5343 
5344     got = INT2PTR(void*, (UV)(key & HSm_KEY_MATCH));
5345     need = (void *)(HS_KEY(FALSE, FALSE, "", "") & HSm_KEY_MATCH);
5346     if (UNLIKELY(got != need))
5347 	goto bad_handshake;
5348 /* try to catch where a 2nd threaded perl interp DLL is loaded into a process
5349    by a XS DLL compiled against the wrong interl DLL b/c of bad @INC, and the
5350    2nd threaded perl interp DLL never initialized its TLS/PERL_SYS_INIT3 so
5351    dTHX call from 2nd interp DLL can't return the my_perl that pp_entersub
5352    passed to the XS DLL */
5353 #ifdef PERL_IMPLICIT_CONTEXT
5354     xs_interp = (tTHX)v_my_perl;
5355     got = xs_interp;
5356     need = my_perl;
5357 #else
5358 /* try to catch where an unthreaded perl interp DLL (for ex. perl522.dll) is
5359    loaded into a process by a XS DLL built by an unthreaded perl522.dll perl,
5360    but the DynaLoder/Perl that started the process and loaded the XS DLL is
5361    unthreaded perl524.dll, since unthreadeds don't pass my_perl (a unique *)
5362    through pp_entersub, use a unique value (which is a pointer to PL_stack_sp's
5363    location in the unthreaded perl binary) stored in CV * to figure out if this
5364    Perl_xs_handshake was called by the same pp_entersub */
5365     cv = (CV*)v_my_perl;
5366     xs_spp = (SV***)CvHSCXT(cv);
5367     got = xs_spp;
5368     need = &PL_stack_sp;
5369 #endif
5370     if(UNLIKELY(got != need)) {
5371 	bad_handshake:/* recycle branch and string from above */
5372 	if(got != (void *)HSf_NOCHK)
5373 	    noperl_die("%s: loadable library and perl binaries are mismatched"
5374                        " (got handshake key %p, needed %p)\n",
5375 		file, got, need);
5376     }
5377 
5378     if(key & HSf_SETXSUBFN) {     /* this might be called from a module bootstrap */
5379 	SAVEPPTR(PL_xsubfilename);/* which was require'd from a XSUB BEGIN */
5380 	PL_xsubfilename = file;   /* so the old name must be restored for
5381 				     additional XSUBs to register themselves */
5382 	/* XSUBs can't be perl lang/perl5db.pl debugged
5383 	if (PERLDB_LINE_OR_SAVESRC)
5384 	    (void)gv_fetchfile(file); */
5385     }
5386 
5387     if(key & HSf_POPMARK) {
5388 	ax = POPMARK;
5389 	{   SV **mark = PL_stack_base + ax++;
5390 	    {   dSP;
5391 		items = (I32)(SP - MARK);
5392 	    }
5393 	}
5394     } else {
5395 	items = va_arg(args, U32);
5396 	ax = va_arg(args, U32);
5397     }
5398     {
5399 	U32 apiverlen;
5400 	assert(HS_GETAPIVERLEN(key) <= UCHAR_MAX);
5401 	if((apiverlen = HS_GETAPIVERLEN(key))) {
5402 	    char * api_p = va_arg(args, char*);
5403 	    if(apiverlen != sizeof("v" PERL_API_VERSION_STRING)-1
5404 		|| memNE(api_p, "v" PERL_API_VERSION_STRING,
5405 			 sizeof("v" PERL_API_VERSION_STRING)-1))
5406 		Perl_croak_nocontext("Perl API version %s of %" SVf " does not match %s",
5407 				    api_p, SVfARG(PL_stack_base[ax + 0]),
5408 				    "v" PERL_API_VERSION_STRING);
5409 	}
5410     }
5411     {
5412 	U32 xsverlen;
5413 	assert(HS_GETXSVERLEN(key) <= UCHAR_MAX && HS_GETXSVERLEN(key) <= HS_APIVERLEN_MAX);
5414 	if((xsverlen = HS_GETXSVERLEN(key)))
5415 	    S_xs_version_bootcheck(aTHX_
5416 		items, ax, va_arg(args, char*), xsverlen);
5417     }
5418     va_end(args);
5419     return ax;
5420 }
5421 
5422 
5423 STATIC void
5424 S_xs_version_bootcheck(pTHX_ U32 items, U32 ax, const char *xs_p,
5425 			  STRLEN xs_len)
5426 {
5427     SV *sv;
5428     const char *vn = NULL;
5429     SV *const module = PL_stack_base[ax];
5430 
5431     PERL_ARGS_ASSERT_XS_VERSION_BOOTCHECK;
5432 
5433     if (items >= 2)	 /* version supplied as bootstrap arg */
5434 	sv = PL_stack_base[ax + 1];
5435     else {
5436 	/* XXX GV_ADDWARN */
5437 	vn = "XS_VERSION";
5438 	sv = get_sv(Perl_form(aTHX_ "%" SVf "::%s", SVfARG(module), vn), 0);
5439 	if (!sv || !SvOK(sv)) {
5440 	    vn = "VERSION";
5441 	    sv = get_sv(Perl_form(aTHX_ "%" SVf "::%s", SVfARG(module), vn), 0);
5442 	}
5443     }
5444     if (sv) {
5445 	SV *xssv = Perl_newSVpvn_flags(aTHX_ xs_p, xs_len, SVs_TEMP);
5446 	SV *pmsv = sv_isobject(sv) && sv_derived_from(sv, "version")
5447 	    ? sv : sv_2mortal(new_version(sv));
5448 	xssv = upg_version(xssv, 0);
5449 	if ( vcmp(pmsv,xssv) ) {
5450 	    SV *string = vstringify(xssv);
5451 	    SV *xpt = Perl_newSVpvf(aTHX_ "%" SVf " object version %" SVf
5452 				    " does not match ", SVfARG(module), SVfARG(string));
5453 
5454 	    SvREFCNT_dec(string);
5455 	    string = vstringify(pmsv);
5456 
5457 	    if (vn) {
5458 		Perl_sv_catpvf(aTHX_ xpt, "$%" SVf "::%s %" SVf, SVfARG(module), vn,
5459 			       SVfARG(string));
5460 	    } else {
5461 		Perl_sv_catpvf(aTHX_ xpt, "bootstrap parameter %" SVf, SVfARG(string));
5462 	    }
5463 	    SvREFCNT_dec(string);
5464 
5465 	    Perl_sv_2mortal(aTHX_ xpt);
5466 	    Perl_croak_sv(aTHX_ xpt);
5467 	}
5468     }
5469 }
5470 
5471 /*
5472 =for apidoc my_strlcat
5473 
5474 The C library C<strlcat> if available, or a Perl implementation of it.
5475 This operates on C C<NUL>-terminated strings.
5476 
5477 C<my_strlcat()> appends string C<src> to the end of C<dst>.  It will append at
5478 most S<C<size - strlen(dst) - 1>> characters.  It will then C<NUL>-terminate,
5479 unless C<size> is 0 or the original C<dst> string was longer than C<size> (in
5480 practice this should not happen as it means that either C<size> is incorrect or
5481 that C<dst> is not a proper C<NUL>-terminated string).
5482 
5483 Note that C<size> is the full size of the destination buffer and
5484 the result is guaranteed to be C<NUL>-terminated if there is room.  Note that
5485 room for the C<NUL> should be included in C<size>.
5486 
5487 The return value is the total length that C<dst> would have if C<size> is
5488 sufficiently large.  Thus it is the initial length of C<dst> plus the length of
5489 C<src>.  If C<size> is smaller than the return, the excess was not appended.
5490 
5491 =cut
5492 
5493 Description stolen from http://man.openbsd.org/strlcat.3
5494 */
5495 #ifndef HAS_STRLCAT
5496 Size_t
5497 Perl_my_strlcat(char *dst, const char *src, Size_t size)
5498 {
5499     Size_t used, length, copy;
5500 
5501     used = strlen(dst);
5502     length = strlen(src);
5503     if (size > 0 && used < size - 1) {
5504         copy = (length >= size - used) ? size - used - 1 : length;
5505         memcpy(dst + used, src, copy);
5506         dst[used + copy] = '\0';
5507     }
5508     return used + length;
5509 }
5510 #endif
5511 
5512 
5513 /*
5514 =for apidoc my_strlcpy
5515 
5516 The C library C<strlcpy> if available, or a Perl implementation of it.
5517 This operates on C C<NUL>-terminated strings.
5518 
5519 C<my_strlcpy()> copies up to S<C<size - 1>> characters from the string C<src>
5520 to C<dst>, C<NUL>-terminating the result if C<size> is not 0.
5521 
5522 The return value is the total length C<src> would be if the copy completely
5523 succeeded.  If it is larger than C<size>, the excess was not copied.
5524 
5525 =cut
5526 
5527 Description stolen from http://man.openbsd.org/strlcpy.3
5528 */
5529 #ifndef HAS_STRLCPY
5530 Size_t
5531 Perl_my_strlcpy(char *dst, const char *src, Size_t size)
5532 {
5533     Size_t length, copy;
5534 
5535     length = strlen(src);
5536     if (size > 0) {
5537         copy = (length >= size) ? size - 1 : length;
5538         memcpy(dst, src, copy);
5539         dst[copy] = '\0';
5540     }
5541     return length;
5542 }
5543 #endif
5544 
5545 /*
5546 =for apidoc my_strnlen
5547 
5548 The C library C<strnlen> if available, or a Perl implementation of it.
5549 
5550 C<my_strnlen()> computes the length of the string, up to C<maxlen>
5551 characters.  It will will never attempt to address more than C<maxlen>
5552 characters, making it suitable for use with strings that are not
5553 guaranteed to be NUL-terminated.
5554 
5555 =cut
5556 
5557 Description stolen from http://man.openbsd.org/strnlen.3,
5558 implementation stolen from PostgreSQL.
5559 */
5560 #ifndef HAS_STRNLEN
5561 Size_t
5562 Perl_my_strnlen(const char *str, Size_t maxlen)
5563 {
5564     const char *p = str;
5565 
5566     PERL_ARGS_ASSERT_MY_STRNLEN;
5567 
5568     while(maxlen-- && *p)
5569         p++;
5570 
5571     return p - str;
5572 }
5573 #endif
5574 
5575 #if defined(_MSC_VER) && (_MSC_VER >= 1300) && (_MSC_VER < 1400) && (WINVER < 0x0500)
5576 /* VC7 or 7.1, building with pre-VC7 runtime libraries. */
5577 long _ftol( double ); /* Defined by VC6 C libs. */
5578 long _ftol2( double dblSource ) { return _ftol( dblSource ); }
5579 #endif
5580 
5581 PERL_STATIC_INLINE bool
5582 S_gv_has_usable_name(pTHX_ GV *gv)
5583 {
5584     GV **gvp;
5585     return GvSTASH(gv)
5586 	&& HvENAME(GvSTASH(gv))
5587 	&& (gvp = (GV **)hv_fetchhek(
5588 			GvSTASH(gv), GvNAME_HEK(gv), 0
5589 	   ))
5590 	&& *gvp == gv;
5591 }
5592 
5593 void
5594 Perl_get_db_sub(pTHX_ SV **svp, CV *cv)
5595 {
5596     SV * const dbsv = GvSVn(PL_DBsub);
5597     const bool save_taint = TAINT_get;
5598 
5599     /* When we are called from pp_goto (svp is null),
5600      * we do not care about using dbsv to call CV;
5601      * it's for informational purposes only.
5602      */
5603 
5604     PERL_ARGS_ASSERT_GET_DB_SUB;
5605 
5606     TAINT_set(FALSE);
5607     save_item(dbsv);
5608     if (!PERLDB_SUB_NN) {
5609 	GV *gv = CvGV(cv);
5610 
5611 	if (!svp && !CvLEXICAL(cv)) {
5612 	    gv_efullname3(dbsv, gv, NULL);
5613 	}
5614 	else if ( (CvFLAGS(cv) & (CVf_ANON | CVf_CLONED)) || CvLEXICAL(cv)
5615 	     || strEQ(GvNAME(gv), "END")
5616 	     || ( /* Could be imported, and old sub redefined. */
5617 		 (GvCV(gv) != cv || !S_gv_has_usable_name(aTHX_ gv))
5618 		 &&
5619 		 !( (SvTYPE(*svp) == SVt_PVGV)
5620 		    && (GvCV((const GV *)*svp) == cv)
5621 		    /* Use GV from the stack as a fallback. */
5622 		    && S_gv_has_usable_name(aTHX_ gv = (GV *)*svp)
5623 		  )
5624 		)
5625 	) {
5626 	    /* GV is potentially non-unique, or contain different CV. */
5627 	    SV * const tmp = newRV(MUTABLE_SV(cv));
5628 	    sv_setsv(dbsv, tmp);
5629 	    SvREFCNT_dec(tmp);
5630 	}
5631 	else {
5632 	    sv_sethek(dbsv, HvENAME_HEK(GvSTASH(gv)));
5633 	    sv_catpvs(dbsv, "::");
5634 	    sv_cathek(dbsv, GvNAME_HEK(gv));
5635 	}
5636     }
5637     else {
5638 	const int type = SvTYPE(dbsv);
5639 	if (type < SVt_PVIV && type != SVt_IV)
5640 	    sv_upgrade(dbsv, SVt_PVIV);
5641 	(void)SvIOK_on(dbsv);
5642 	SvIV_set(dbsv, PTR2IV(cv));	/* Do it the quickest way  */
5643     }
5644     SvSETMAGIC(dbsv);
5645     TAINT_IF(save_taint);
5646 #ifdef NO_TAINT_SUPPORT
5647     PERL_UNUSED_VAR(save_taint);
5648 #endif
5649 }
5650 
5651 int
5652 Perl_my_dirfd(DIR * dir) {
5653 
5654     /* Most dirfd implementations have problems when passed NULL. */
5655     if(!dir)
5656         return -1;
5657 #ifdef HAS_DIRFD
5658     return dirfd(dir);
5659 #elif defined(HAS_DIR_DD_FD)
5660     return dir->dd_fd;
5661 #else
5662     Perl_croak_nocontext(PL_no_func, "dirfd");
5663     NOT_REACHED; /* NOTREACHED */
5664     return 0;
5665 #endif
5666 }
5667 
5668 #if !defined(HAS_MKOSTEMP) || !defined(HAS_MKSTEMP)
5669 
5670 #define TEMP_FILE_CH "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvxyz0123456789"
5671 #define TEMP_FILE_CH_COUNT (sizeof(TEMP_FILE_CH)-1)
5672 
5673 static int
5674 S_my_mkostemp(char *templte, int flags) {
5675     dTHX;
5676     STRLEN len = strlen(templte);
5677     int fd;
5678     int attempts = 0;
5679 
5680     if (len < 6 ||
5681         templte[len-1] != 'X' || templte[len-2] != 'X' || templte[len-3] != 'X' ||
5682         templte[len-4] != 'X' || templte[len-5] != 'X' || templte[len-6] != 'X') {
5683         SETERRNO(EINVAL, LIB_INVARG);
5684         return -1;
5685     }
5686 
5687     do {
5688         int i;
5689         for (i = 1; i <= 6; ++i) {
5690             templte[len-i] = TEMP_FILE_CH[(int)(Perl_internal_drand48() * TEMP_FILE_CH_COUNT)];
5691         }
5692         fd = PerlLIO_open3(templte, O_RDWR | O_CREAT | O_EXCL | flags, 0600);
5693     } while (fd == -1 && errno == EEXIST && ++attempts <= 100);
5694 
5695     return fd;
5696 }
5697 
5698 #endif
5699 
5700 #ifndef HAS_MKOSTEMP
5701 int
5702 Perl_my_mkostemp(char *templte, int flags)
5703 {
5704     PERL_ARGS_ASSERT_MY_MKOSTEMP;
5705     return S_my_mkostemp(templte, flags);
5706 }
5707 #endif
5708 
5709 #ifndef HAS_MKSTEMP
5710 int
5711 Perl_my_mkstemp(char *templte)
5712 {
5713     PERL_ARGS_ASSERT_MY_MKSTEMP;
5714     return S_my_mkostemp(templte, 0);
5715 }
5716 #endif
5717 
5718 REGEXP *
5719 Perl_get_re_arg(pTHX_ SV *sv) {
5720 
5721     if (sv) {
5722         if (SvMAGICAL(sv))
5723             mg_get(sv);
5724         if (SvROK(sv))
5725 	    sv = MUTABLE_SV(SvRV(sv));
5726         if (SvTYPE(sv) == SVt_REGEXP)
5727             return (REGEXP*) sv;
5728     }
5729 
5730     return NULL;
5731 }
5732 
5733 /*
5734  * This code is derived from drand48() implementation from FreeBSD,
5735  * found in lib/libc/gen/_rand48.c.
5736  *
5737  * The U64 implementation is original, based on the POSIX
5738  * specification for drand48().
5739  */
5740 
5741 /*
5742 * Copyright (c) 1993 Martin Birgmeier
5743 * All rights reserved.
5744 *
5745 * You may redistribute unmodified or modified versions of this source
5746 * code provided that the above copyright notice and this and the
5747 * following conditions are retained.
5748 *
5749 * This software is provided ``as is'', and comes with no warranties
5750 * of any kind. I shall in no event be liable for anything that happens
5751 * to anyone/anything when using this software.
5752 */
5753 
5754 #define FREEBSD_DRAND48_SEED_0   (0x330e)
5755 
5756 #ifdef PERL_DRAND48_QUAD
5757 
5758 #define DRAND48_MULT UINT64_C(0x5deece66d)
5759 #define DRAND48_ADD  0xb
5760 #define DRAND48_MASK UINT64_C(0xffffffffffff)
5761 
5762 #else
5763 
5764 #define FREEBSD_DRAND48_SEED_1   (0xabcd)
5765 #define FREEBSD_DRAND48_SEED_2   (0x1234)
5766 #define FREEBSD_DRAND48_MULT_0   (0xe66d)
5767 #define FREEBSD_DRAND48_MULT_1   (0xdeec)
5768 #define FREEBSD_DRAND48_MULT_2   (0x0005)
5769 #define FREEBSD_DRAND48_ADD      (0x000b)
5770 
5771 const unsigned short _rand48_mult[3] = {
5772                 FREEBSD_DRAND48_MULT_0,
5773                 FREEBSD_DRAND48_MULT_1,
5774                 FREEBSD_DRAND48_MULT_2
5775 };
5776 const unsigned short _rand48_add = FREEBSD_DRAND48_ADD;
5777 
5778 #endif
5779 
5780 void
5781 Perl_drand48_init_r(perl_drand48_t *random_state, U32 seed)
5782 {
5783     PERL_ARGS_ASSERT_DRAND48_INIT_R;
5784 
5785 #ifdef PERL_DRAND48_QUAD
5786     *random_state = FREEBSD_DRAND48_SEED_0 + ((U64)seed << 16);
5787 #else
5788     random_state->seed[0] = FREEBSD_DRAND48_SEED_0;
5789     random_state->seed[1] = (U16) seed;
5790     random_state->seed[2] = (U16) (seed >> 16);
5791 #endif
5792 }
5793 
5794 double
5795 Perl_drand48_r(perl_drand48_t *random_state)
5796 {
5797     PERL_ARGS_ASSERT_DRAND48_R;
5798 
5799 #ifdef PERL_DRAND48_QUAD
5800     *random_state = (*random_state * DRAND48_MULT + DRAND48_ADD)
5801         & DRAND48_MASK;
5802 
5803     return ldexp((double)*random_state, -48);
5804 #else
5805     {
5806     U32 accu;
5807     U16 temp[2];
5808 
5809     accu = (U32) _rand48_mult[0] * (U32) random_state->seed[0]
5810          + (U32) _rand48_add;
5811     temp[0] = (U16) accu;        /* lower 16 bits */
5812     accu >>= sizeof(U16) * 8;
5813     accu += (U32) _rand48_mult[0] * (U32) random_state->seed[1]
5814           + (U32) _rand48_mult[1] * (U32) random_state->seed[0];
5815     temp[1] = (U16) accu;        /* middle 16 bits */
5816     accu >>= sizeof(U16) * 8;
5817     accu += _rand48_mult[0] * random_state->seed[2]
5818           + _rand48_mult[1] * random_state->seed[1]
5819           + _rand48_mult[2] * random_state->seed[0];
5820     random_state->seed[0] = temp[0];
5821     random_state->seed[1] = temp[1];
5822     random_state->seed[2] = (U16) accu;
5823 
5824     return ldexp((double) random_state->seed[0], -48) +
5825            ldexp((double) random_state->seed[1], -32) +
5826            ldexp((double) random_state->seed[2], -16);
5827     }
5828 #endif
5829 }
5830 
5831 #ifdef USE_C_BACKTRACE
5832 
5833 /* Possibly move all this USE_C_BACKTRACE code into a new file. */
5834 
5835 #ifdef USE_BFD
5836 
5837 typedef struct {
5838     /* abfd is the BFD handle. */
5839     bfd* abfd;
5840     /* bfd_syms is the BFD symbol table. */
5841     asymbol** bfd_syms;
5842     /* bfd_text is handle to the the ".text" section of the object file. */
5843     asection* bfd_text;
5844     /* Since opening the executable and scanning its symbols is quite
5845      * heavy operation, we remember the filename we used the last time,
5846      * and do the opening and scanning only if the filename changes.
5847      * This removes most (but not all) open+scan cycles. */
5848     const char* fname_prev;
5849 } bfd_context;
5850 
5851 /* Given a dl_info, update the BFD context if necessary. */
5852 static void bfd_update(bfd_context* ctx, Dl_info* dl_info)
5853 {
5854     /* BFD open and scan only if the filename changed. */
5855     if (ctx->fname_prev == NULL ||
5856         strNE(dl_info->dli_fname, ctx->fname_prev)) {
5857         if (ctx->abfd) {
5858             bfd_close(ctx->abfd);
5859         }
5860         ctx->abfd = bfd_openr(dl_info->dli_fname, 0);
5861         if (ctx->abfd) {
5862             if (bfd_check_format(ctx->abfd, bfd_object)) {
5863                 IV symbol_size = bfd_get_symtab_upper_bound(ctx->abfd);
5864                 if (symbol_size > 0) {
5865                     Safefree(ctx->bfd_syms);
5866                     Newx(ctx->bfd_syms, symbol_size, asymbol*);
5867                     ctx->bfd_text =
5868                         bfd_get_section_by_name(ctx->abfd, ".text");
5869                 }
5870                 else
5871                     ctx->abfd = NULL;
5872             }
5873             else
5874                 ctx->abfd = NULL;
5875         }
5876         ctx->fname_prev = dl_info->dli_fname;
5877     }
5878 }
5879 
5880 /* Given a raw frame, try to symbolize it and store
5881  * symbol information (source file, line number) away. */
5882 static void bfd_symbolize(bfd_context* ctx,
5883                           void* raw_frame,
5884                           char** symbol_name,
5885                           STRLEN* symbol_name_size,
5886                           char** source_name,
5887                           STRLEN* source_name_size,
5888                           STRLEN* source_line)
5889 {
5890     *symbol_name = NULL;
5891     *symbol_name_size = 0;
5892     if (ctx->abfd) {
5893         IV offset = PTR2IV(raw_frame) - PTR2IV(ctx->bfd_text->vma);
5894         if (offset > 0 &&
5895             bfd_canonicalize_symtab(ctx->abfd, ctx->bfd_syms) > 0) {
5896             const char *file;
5897             const char *func;
5898             unsigned int line = 0;
5899             if (bfd_find_nearest_line(ctx->abfd, ctx->bfd_text,
5900                                       ctx->bfd_syms, offset,
5901                                       &file, &func, &line) &&
5902                 file && func && line > 0) {
5903                 /* Size and copy the source file, use only
5904                  * the basename of the source file.
5905                  *
5906                  * NOTE: the basenames are fine for the
5907                  * Perl source files, but may not always
5908                  * be the best idea for XS files. */
5909                 const char *p, *b = NULL;
5910                 /* Look for the last slash. */
5911                 for (p = file; *p; p++) {
5912                     if (*p == '/')
5913                         b = p + 1;
5914                 }
5915                 if (b == NULL || *b == 0) {
5916                     b = file;
5917                 }
5918                 *source_name_size = p - b + 1;
5919                 Newx(*source_name, *source_name_size + 1, char);
5920                 Copy(b, *source_name, *source_name_size + 1, char);
5921 
5922                 *symbol_name_size = strlen(func);
5923                 Newx(*symbol_name, *symbol_name_size + 1, char);
5924                 Copy(func, *symbol_name, *symbol_name_size + 1, char);
5925 
5926                 *source_line = line;
5927             }
5928         }
5929     }
5930 }
5931 
5932 #endif /* #ifdef USE_BFD */
5933 
5934 #ifdef PERL_DARWIN
5935 
5936 /* OS X has no public API for for 'symbolicating' (Apple official term)
5937  * stack addresses to {function_name, source_file, line_number}.
5938  * Good news: there is command line utility atos(1) which does that.
5939  * Bad news 1: it's a command line utility.
5940  * Bad news 2: one needs to have the Developer Tools installed.
5941  * Bad news 3: in newer releases it needs to be run as 'xcrun atos'.
5942  *
5943  * To recap: we need to open a pipe for reading for a utility which
5944  * might not exist, or exists in different locations, and then parse
5945  * the output.  And since this is all for a low-level API, we cannot
5946  * use high-level stuff.  Thanks, Apple. */
5947 
5948 typedef struct {
5949     /* tool is set to the absolute pathname of the tool to use:
5950      * xcrun or atos. */
5951     const char* tool;
5952     /* format is set to a printf format string used for building
5953      * the external command to run. */
5954     const char* format;
5955     /* unavail is set if e.g. xcrun cannot be found, or something
5956      * else happens that makes getting the backtrace dubious.  Note,
5957      * however, that the context isn't persistent, the next call to
5958      * get_c_backtrace() will start from scratch. */
5959     bool unavail;
5960     /* fname is the current object file name. */
5961     const char* fname;
5962     /* object_base_addr is the base address of the shared object. */
5963     void* object_base_addr;
5964 } atos_context;
5965 
5966 /* Given |dl_info|, updates the context.  If the context has been
5967  * marked unavailable, return immediately.  If not but the tool has
5968  * not been set, set it to either "xcrun atos" or "atos" (also set the
5969  * format to use for creating commands for piping), or if neither is
5970  * unavailable (one needs the Developer Tools installed), mark the context
5971  * an unavailable.  Finally, update the filename (object name),
5972  * and its base address. */
5973 
5974 static void atos_update(atos_context* ctx,
5975                         Dl_info* dl_info)
5976 {
5977     if (ctx->unavail)
5978         return;
5979     if (ctx->tool == NULL) {
5980         const char* tools[] = {
5981             "/usr/bin/xcrun",
5982             "/usr/bin/atos"
5983         };
5984         const char* formats[] = {
5985             "/usr/bin/xcrun atos -o '%s' -l %08x %08x 2>&1",
5986             "/usr/bin/atos -d -o '%s' -l %08x %08x 2>&1"
5987         };
5988         struct stat st;
5989         UV i;
5990         for (i = 0; i < C_ARRAY_LENGTH(tools); i++) {
5991             if (stat(tools[i], &st) == 0 && S_ISREG(st.st_mode)) {
5992                 ctx->tool = tools[i];
5993                 ctx->format = formats[i];
5994                 break;
5995             }
5996         }
5997         if (ctx->tool == NULL) {
5998             ctx->unavail = TRUE;
5999             return;
6000         }
6001     }
6002     if (ctx->fname == NULL ||
6003         strNE(dl_info->dli_fname, ctx->fname)) {
6004         ctx->fname = dl_info->dli_fname;
6005         ctx->object_base_addr = dl_info->dli_fbase;
6006     }
6007 }
6008 
6009 /* Given an output buffer end |p| and its |start|, matches
6010  * for the atos output, extracting the source code location
6011  * and returning non-NULL if possible, returning NULL otherwise. */
6012 static const char* atos_parse(const char* p,
6013                               const char* start,
6014                               STRLEN* source_name_size,
6015                               STRLEN* source_line) {
6016     /* atos() output is something like:
6017      * perl_parse (in miniperl) (perl.c:2314)\n\n".
6018      * We cannot use Perl regular expressions, because we need to
6019      * stay low-level.  Therefore here we have a rolled-out version
6020      * of a state machine which matches _backwards_from_the_end_ and
6021      * if there's a success, returns the starts of the filename,
6022      * also setting the filename size and the source line number.
6023      * The matched regular expression is roughly "\(.*:\d+\)\s*$" */
6024     const char* source_number_start;
6025     const char* source_name_end;
6026     const char* source_line_end;
6027     const char* close_paren;
6028     UV uv;
6029 
6030     /* Skip trailing whitespace. */
6031     while (p > start && isSPACE(*p)) p--;
6032     /* Now we should be at the close paren. */
6033     if (p == start || *p != ')')
6034         return NULL;
6035     close_paren = p;
6036     p--;
6037     /* Now we should be in the line number. */
6038     if (p == start || !isDIGIT(*p))
6039         return NULL;
6040     /* Skip over the digits. */
6041     while (p > start && isDIGIT(*p))
6042         p--;
6043     /* Now we should be at the colon. */
6044     if (p == start || *p != ':')
6045         return NULL;
6046     source_number_start = p + 1;
6047     source_name_end = p; /* Just beyond the end. */
6048     p--;
6049     /* Look for the open paren. */
6050     while (p > start && *p != '(')
6051         p--;
6052     if (p == start)
6053         return NULL;
6054     p++;
6055     *source_name_size = source_name_end - p;
6056     if (grok_atoUV(source_number_start, &uv,  &source_line_end)
6057         && source_line_end == close_paren
6058         && uv <= PERL_INT_MAX
6059     ) {
6060         *source_line = (STRLEN)uv;
6061         return p;
6062     }
6063     return NULL;
6064 }
6065 
6066 /* Given a raw frame, read a pipe from the symbolicator (that's the
6067  * technical term) atos, reads the result, and parses the source code
6068  * location.  We must stay low-level, so we use snprintf(), pipe(),
6069  * and fread(), and then also parse the output ourselves. */
6070 static void atos_symbolize(atos_context* ctx,
6071                            void* raw_frame,
6072                            char** source_name,
6073                            STRLEN* source_name_size,
6074                            STRLEN* source_line)
6075 {
6076     char cmd[1024];
6077     const char* p;
6078     Size_t cnt;
6079 
6080     if (ctx->unavail)
6081         return;
6082     /* Simple security measure: if there's any funny business with
6083      * the object name (used as "-o '%s'" ), leave since at least
6084      * partially the user controls it. */
6085     for (p = ctx->fname; *p; p++) {
6086         if (*p == '\'' || isCNTRL(*p)) {
6087             ctx->unavail = TRUE;
6088             return;
6089         }
6090     }
6091     cnt = snprintf(cmd, sizeof(cmd), ctx->format,
6092                    ctx->fname, ctx->object_base_addr, raw_frame);
6093     if (cnt < sizeof(cmd)) {
6094         /* Undo nostdio.h #defines that disable stdio.
6095          * This is somewhat naughty, but is used elsewhere
6096          * in the core, and affects only OS X. */
6097 #undef FILE
6098 #undef popen
6099 #undef fread
6100 #undef pclose
6101         FILE* fp = popen(cmd, "r");
6102         /* At the moment we open a new pipe for each stack frame.
6103          * This is naturally somewhat slow, but hopefully generating
6104          * stack traces is never going to in a performance critical path.
6105          *
6106          * We could play tricks with atos by batching the stack
6107          * addresses to be resolved: atos can either take multiple
6108          * addresses from the command line, or read addresses from
6109          * a file (though the mess of creating temporary files would
6110          * probably negate much of any possible speedup).
6111          *
6112          * Normally there are only two objects present in the backtrace:
6113          * perl itself, and the libdyld.dylib.  (Note that the object
6114          * filenames contain the full pathname, so perl may not always
6115          * be in the same place.)  Whenever the object in the
6116          * backtrace changes, the base address also changes.
6117          *
6118          * The problem with batching the addresses, though, would be
6119          * matching the results with the addresses: the parsing of
6120          * the results is already painful enough with a single address. */
6121         if (fp) {
6122             char out[1024];
6123             UV cnt = fread(out, 1, sizeof(out), fp);
6124             if (cnt < sizeof(out)) {
6125                 const char* p = atos_parse(out + cnt - 1, out,
6126                                            source_name_size,
6127                                            source_line);
6128                 if (p) {
6129                     Newx(*source_name,
6130                          *source_name_size, char);
6131                     Copy(p, *source_name,
6132                          *source_name_size,  char);
6133                 }
6134             }
6135             pclose(fp);
6136         }
6137     }
6138 }
6139 
6140 #endif /* #ifdef PERL_DARWIN */
6141 
6142 /*
6143 =for apidoc get_c_backtrace
6144 
6145 Collects the backtrace (aka "stacktrace") into a single linear
6146 malloced buffer, which the caller B<must> C<Perl_free_c_backtrace()>.
6147 
6148 Scans the frames back by S<C<depth + skip>>, then drops the C<skip> innermost,
6149 returning at most C<depth> frames.
6150 
6151 =cut
6152 */
6153 
6154 Perl_c_backtrace*
6155 Perl_get_c_backtrace(pTHX_ int depth, int skip)
6156 {
6157     /* Note that here we must stay as low-level as possible: Newx(),
6158      * Copy(), Safefree(); since we may be called from anywhere,
6159      * so we should avoid higher level constructs like SVs or AVs.
6160      *
6161      * Since we are using safesysmalloc() via Newx(), don't try
6162      * getting backtrace() there, unless you like deep recursion. */
6163 
6164     /* Currently only implemented with backtrace() and dladdr(),
6165      * for other platforms NULL is returned. */
6166 
6167 #if defined(HAS_BACKTRACE) && defined(HAS_DLADDR)
6168     /* backtrace() is available via <execinfo.h> in glibc and in most
6169      * modern BSDs; dladdr() is available via <dlfcn.h>. */
6170 
6171     /* We try fetching this many frames total, but then discard
6172      * the |skip| first ones.  For the remaining ones we will try
6173      * retrieving more information with dladdr(). */
6174     int try_depth = skip +  depth;
6175 
6176     /* The addresses (program counters) returned by backtrace(). */
6177     void** raw_frames;
6178 
6179     /* Retrieved with dladdr() from the addresses returned by backtrace(). */
6180     Dl_info* dl_infos;
6181 
6182     /* Sizes _including_ the terminating \0 of the object name
6183      * and symbol name strings. */
6184     STRLEN* object_name_sizes;
6185     STRLEN* symbol_name_sizes;
6186 
6187 #ifdef USE_BFD
6188     /* The symbol names comes either from dli_sname,
6189      * or if using BFD, they can come from BFD. */
6190     char** symbol_names;
6191 #endif
6192 
6193     /* The source code location information.  Dug out with e.g. BFD. */
6194     char** source_names;
6195     STRLEN* source_name_sizes;
6196     STRLEN* source_lines;
6197 
6198     Perl_c_backtrace* bt = NULL;  /* This is what will be returned. */
6199     int got_depth; /* How many frames were returned from backtrace(). */
6200     UV frame_count = 0; /* How many frames we return. */
6201     UV total_bytes = 0; /* The size of the whole returned backtrace. */
6202 
6203 #ifdef USE_BFD
6204     bfd_context bfd_ctx;
6205 #endif
6206 #ifdef PERL_DARWIN
6207     atos_context atos_ctx;
6208 #endif
6209 
6210     /* Here are probably possibilities for optimizing.  We could for
6211      * example have a struct that contains most of these and then
6212      * allocate |try_depth| of them, saving a bunch of malloc calls.
6213      * Note, however, that |frames| could not be part of that struct
6214      * because backtrace() will want an array of just them.  Also be
6215      * careful about the name strings. */
6216     Newx(raw_frames, try_depth, void*);
6217     Newx(dl_infos, try_depth, Dl_info);
6218     Newx(object_name_sizes, try_depth, STRLEN);
6219     Newx(symbol_name_sizes, try_depth, STRLEN);
6220     Newx(source_names, try_depth, char*);
6221     Newx(source_name_sizes, try_depth, STRLEN);
6222     Newx(source_lines, try_depth, STRLEN);
6223 #ifdef USE_BFD
6224     Newx(symbol_names, try_depth, char*);
6225 #endif
6226 
6227     /* Get the raw frames. */
6228     got_depth = (int)backtrace(raw_frames, try_depth);
6229 
6230     /* We use dladdr() instead of backtrace_symbols() because we want
6231      * the full details instead of opaque strings.  This is useful for
6232      * two reasons: () the details are needed for further symbolic
6233      * digging, for example in OS X (2) by having the details we fully
6234      * control the output, which in turn is useful when more platforms
6235      * are added: we can keep out output "portable". */
6236 
6237     /* We want a single linear allocation, which can then be freed
6238      * with a single swoop.  We will do the usual trick of first
6239      * walking over the structure and seeing how much we need to
6240      * allocate, then allocating, and then walking over the structure
6241      * the second time and populating it. */
6242 
6243     /* First we must compute the total size of the buffer. */
6244     total_bytes = sizeof(Perl_c_backtrace_header);
6245     if (got_depth > skip) {
6246         int i;
6247 #ifdef USE_BFD
6248         bfd_init(); /* Is this safe to call multiple times? */
6249         Zero(&bfd_ctx, 1, bfd_context);
6250 #endif
6251 #ifdef PERL_DARWIN
6252         Zero(&atos_ctx, 1, atos_context);
6253 #endif
6254         for (i = skip; i < try_depth; i++) {
6255             Dl_info* dl_info = &dl_infos[i];
6256 
6257             object_name_sizes[i] = 0;
6258             source_names[i] = NULL;
6259             source_name_sizes[i] = 0;
6260             source_lines[i] = 0;
6261 
6262             /* Yes, zero from dladdr() is failure. */
6263             if (dladdr(raw_frames[i], dl_info)) {
6264                 total_bytes += sizeof(Perl_c_backtrace_frame);
6265 
6266                 object_name_sizes[i] =
6267                     dl_info->dli_fname ? strlen(dl_info->dli_fname) : 0;
6268                 symbol_name_sizes[i] =
6269                     dl_info->dli_sname ? strlen(dl_info->dli_sname) : 0;
6270 #ifdef USE_BFD
6271                 bfd_update(&bfd_ctx, dl_info);
6272                 bfd_symbolize(&bfd_ctx, raw_frames[i],
6273                               &symbol_names[i],
6274                               &symbol_name_sizes[i],
6275                               &source_names[i],
6276                               &source_name_sizes[i],
6277                               &source_lines[i]);
6278 #endif
6279 #if PERL_DARWIN
6280                 atos_update(&atos_ctx, dl_info);
6281                 atos_symbolize(&atos_ctx,
6282                                raw_frames[i],
6283                                &source_names[i],
6284                                &source_name_sizes[i],
6285                                &source_lines[i]);
6286 #endif
6287 
6288                 /* Plus ones for the terminating \0. */
6289                 total_bytes += object_name_sizes[i] + 1;
6290                 total_bytes += symbol_name_sizes[i] + 1;
6291                 total_bytes += source_name_sizes[i] + 1;
6292 
6293                 frame_count++;
6294             } else {
6295                 break;
6296             }
6297         }
6298 #ifdef USE_BFD
6299         Safefree(bfd_ctx.bfd_syms);
6300 #endif
6301     }
6302 
6303     /* Now we can allocate and populate the result buffer. */
6304     Newxc(bt, total_bytes, char, Perl_c_backtrace);
6305     Zero(bt, total_bytes, char);
6306     bt->header.frame_count = frame_count;
6307     bt->header.total_bytes = total_bytes;
6308     if (frame_count > 0) {
6309         Perl_c_backtrace_frame* frame = bt->frame_info;
6310         char* name_base = (char *)(frame + frame_count);
6311         char* name_curr = name_base; /* Outputting the name strings here. */
6312         UV i;
6313         for (i = skip; i < skip + frame_count; i++) {
6314             Dl_info* dl_info = &dl_infos[i];
6315 
6316             frame->addr = raw_frames[i];
6317             frame->object_base_addr = dl_info->dli_fbase;
6318             frame->symbol_addr = dl_info->dli_saddr;
6319 
6320             /* Copies a string, including the \0, and advances the name_curr.
6321              * Also copies the start and the size to the frame. */
6322 #define PERL_C_BACKTRACE_STRCPY(frame, doffset, src, dsize, size) \
6323             if (size && src) \
6324                 Copy(src, name_curr, size, char); \
6325             frame->doffset = name_curr - (char*)bt; \
6326             frame->dsize = size; \
6327             name_curr += size; \
6328             *name_curr++ = 0;
6329 
6330             PERL_C_BACKTRACE_STRCPY(frame, object_name_offset,
6331                                     dl_info->dli_fname,
6332                                     object_name_size, object_name_sizes[i]);
6333 
6334 #ifdef USE_BFD
6335             PERL_C_BACKTRACE_STRCPY(frame, symbol_name_offset,
6336                                     symbol_names[i],
6337                                     symbol_name_size, symbol_name_sizes[i]);
6338             Safefree(symbol_names[i]);
6339 #else
6340             PERL_C_BACKTRACE_STRCPY(frame, symbol_name_offset,
6341                                     dl_info->dli_sname,
6342                                     symbol_name_size, symbol_name_sizes[i]);
6343 #endif
6344 
6345             PERL_C_BACKTRACE_STRCPY(frame, source_name_offset,
6346                                     source_names[i],
6347                                     source_name_size, source_name_sizes[i]);
6348             Safefree(source_names[i]);
6349 
6350 #undef PERL_C_BACKTRACE_STRCPY
6351 
6352             frame->source_line_number = source_lines[i];
6353 
6354             frame++;
6355         }
6356         assert(total_bytes ==
6357                (UV)(sizeof(Perl_c_backtrace_header) +
6358                     frame_count * sizeof(Perl_c_backtrace_frame) +
6359                     name_curr - name_base));
6360     }
6361 #ifdef USE_BFD
6362     Safefree(symbol_names);
6363     if (bfd_ctx.abfd) {
6364         bfd_close(bfd_ctx.abfd);
6365     }
6366 #endif
6367     Safefree(source_lines);
6368     Safefree(source_name_sizes);
6369     Safefree(source_names);
6370     Safefree(symbol_name_sizes);
6371     Safefree(object_name_sizes);
6372     /* Assuming the strings returned by dladdr() are pointers
6373      * to read-only static memory (the object file), so that
6374      * they do not need freeing (and cannot be). */
6375     Safefree(dl_infos);
6376     Safefree(raw_frames);
6377     return bt;
6378 #else
6379     PERL_UNUSED_ARGV(depth);
6380     PERL_UNUSED_ARGV(skip);
6381     return NULL;
6382 #endif
6383 }
6384 
6385 /*
6386 =for apidoc free_c_backtrace
6387 
6388 Deallocates a backtrace received from get_c_bracktrace.
6389 
6390 =cut
6391 */
6392 
6393 /*
6394 =for apidoc get_c_backtrace_dump
6395 
6396 Returns a SV containing a dump of C<depth> frames of the call stack, skipping
6397 the C<skip> innermost ones.  C<depth> of 20 is usually enough.
6398 
6399 The appended output looks like:
6400 
6401 ...
6402 1   10e004812:0082   Perl_croak   util.c:1716    /usr/bin/perl
6403 2   10df8d6d2:1d72   perl_parse   perl.c:3975    /usr/bin/perl
6404 ...
6405 
6406 The fields are tab-separated.  The first column is the depth (zero
6407 being the innermost non-skipped frame).  In the hex:offset, the hex is
6408 where the program counter was in C<S_parse_body>, and the :offset (might
6409 be missing) tells how much inside the C<S_parse_body> the program counter was.
6410 
6411 The C<util.c:1716> is the source code file and line number.
6412 
6413 The F</usr/bin/perl> is obvious (hopefully).
6414 
6415 Unknowns are C<"-">.  Unknowns can happen unfortunately quite easily:
6416 if the platform doesn't support retrieving the information;
6417 if the binary is missing the debug information;
6418 if the optimizer has transformed the code by for example inlining.
6419 
6420 =cut
6421 */
6422 
6423 SV*
6424 Perl_get_c_backtrace_dump(pTHX_ int depth, int skip)
6425 {
6426     Perl_c_backtrace* bt;
6427 
6428     bt = get_c_backtrace(depth, skip + 1 /* Hide ourselves. */);
6429     if (bt) {
6430         Perl_c_backtrace_frame* frame;
6431         SV* dsv = newSVpvs("");
6432         UV i;
6433         for (i = 0, frame = bt->frame_info;
6434              i < bt->header.frame_count; i++, frame++) {
6435             Perl_sv_catpvf(aTHX_ dsv, "%d", (int)i);
6436             Perl_sv_catpvf(aTHX_ dsv, "\t%p", frame->addr ? frame->addr : "-");
6437             /* Symbol (function) names might disappear without debug info.
6438              *
6439              * The source code location might disappear in case of the
6440              * optimizer inlining or otherwise rearranging the code. */
6441             if (frame->symbol_addr) {
6442                 Perl_sv_catpvf(aTHX_ dsv, ":%04x",
6443                                (int)
6444                                ((char*)frame->addr - (char*)frame->symbol_addr));
6445             }
6446             Perl_sv_catpvf(aTHX_ dsv, "\t%s",
6447                            frame->symbol_name_size &&
6448                            frame->symbol_name_offset ?
6449                            (char*)bt + frame->symbol_name_offset : "-");
6450             if (frame->source_name_size &&
6451                 frame->source_name_offset &&
6452                 frame->source_line_number) {
6453                 Perl_sv_catpvf(aTHX_ dsv, "\t%s:%" UVuf,
6454                                (char*)bt + frame->source_name_offset,
6455                                (UV)frame->source_line_number);
6456             } else {
6457                 Perl_sv_catpvf(aTHX_ dsv, "\t-");
6458             }
6459             Perl_sv_catpvf(aTHX_ dsv, "\t%s",
6460                            frame->object_name_size &&
6461                            frame->object_name_offset ?
6462                            (char*)bt + frame->object_name_offset : "-");
6463             /* The frame->object_base_addr is not output,
6464              * but it is used for symbolizing/symbolicating. */
6465             sv_catpvs(dsv, "\n");
6466         }
6467 
6468         Perl_free_c_backtrace(bt);
6469 
6470         return dsv;
6471     }
6472 
6473     return NULL;
6474 }
6475 
6476 /*
6477 =for apidoc dump_c_backtrace
6478 
6479 Dumps the C backtrace to the given C<fp>.
6480 
6481 Returns true if a backtrace could be retrieved, false if not.
6482 
6483 =cut
6484 */
6485 
6486 bool
6487 Perl_dump_c_backtrace(pTHX_ PerlIO* fp, int depth, int skip)
6488 {
6489     SV* sv;
6490 
6491     PERL_ARGS_ASSERT_DUMP_C_BACKTRACE;
6492 
6493     sv = Perl_get_c_backtrace_dump(aTHX_ depth, skip);
6494     if (sv) {
6495         sv_2mortal(sv);
6496         PerlIO_printf(fp, "%s", SvPV_nolen(sv));
6497         return TRUE;
6498     }
6499     return FALSE;
6500 }
6501 
6502 #endif /* #ifdef USE_C_BACKTRACE */
6503 
6504 #ifdef PERL_TSA_ACTIVE
6505 
6506 /* pthread_mutex_t and perl_mutex are typedef equivalent
6507  * so casting the pointers is fine. */
6508 
6509 int perl_tsa_mutex_lock(perl_mutex* mutex)
6510 {
6511     return pthread_mutex_lock((pthread_mutex_t *) mutex);
6512 }
6513 
6514 int perl_tsa_mutex_unlock(perl_mutex* mutex)
6515 {
6516     return pthread_mutex_unlock((pthread_mutex_t *) mutex);
6517 }
6518 
6519 int perl_tsa_mutex_destroy(perl_mutex* mutex)
6520 {
6521     return pthread_mutex_destroy((pthread_mutex_t *) mutex);
6522 }
6523 
6524 #endif
6525 
6526 
6527 #ifdef USE_DTRACE
6528 
6529 /* log a sub call or return */
6530 
6531 void
6532 Perl_dtrace_probe_call(pTHX_ CV *cv, bool is_call)
6533 {
6534     const char *func;
6535     const char *file;
6536     const char *stash;
6537     const COP  *start;
6538     line_t      line;
6539 
6540     PERL_ARGS_ASSERT_DTRACE_PROBE_CALL;
6541 
6542     if (CvNAMED(cv)) {
6543         HEK *hek = CvNAME_HEK(cv);
6544         func = HEK_KEY(hek);
6545     }
6546     else {
6547         GV  *gv = CvGV(cv);
6548         func = GvENAME(gv);
6549     }
6550     start = (const COP *)CvSTART(cv);
6551     file  = CopFILE(start);
6552     line  = CopLINE(start);
6553     stash = CopSTASHPV(start);
6554 
6555     if (is_call) {
6556         PERL_SUB_ENTRY(func, file, line, stash);
6557     }
6558     else {
6559         PERL_SUB_RETURN(func, file, line, stash);
6560     }
6561 }
6562 
6563 
6564 /* log a require file loading/loaded  */
6565 
6566 void
6567 Perl_dtrace_probe_load(pTHX_ const char *name, bool is_loading)
6568 {
6569     PERL_ARGS_ASSERT_DTRACE_PROBE_LOAD;
6570 
6571     if (is_loading) {
6572 	PERL_LOADING_FILE(name);
6573     }
6574     else {
6575 	PERL_LOADED_FILE(name);
6576     }
6577 }
6578 
6579 
6580 /* log an op execution */
6581 
6582 void
6583 Perl_dtrace_probe_op(pTHX_ const OP *op)
6584 {
6585     PERL_ARGS_ASSERT_DTRACE_PROBE_OP;
6586 
6587     PERL_OP_ENTRY(OP_NAME(op));
6588 }
6589 
6590 
6591 /* log a compile/run phase change */
6592 
6593 void
6594 Perl_dtrace_probe_phase(pTHX_ enum perl_phase phase)
6595 {
6596     const char *ph_old = PL_phase_names[PL_phase];
6597     const char *ph_new = PL_phase_names[phase];
6598 
6599     PERL_PHASE_CHANGE(ph_new, ph_old);
6600 }
6601 
6602 #endif
6603 
6604 /*
6605  * ex: set ts=8 sts=4 sw=4 et:
6606  */
6607