xref: /openbsd-src/gnu/usr.bin/perl/util.c (revision 7350f337b9e3eb4461d99580e625c7ef148d107c)
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 	    setfd_cloexec_or_inhexec_by_sysfdness(p[THIS]);
2307 	    PerlLIO_close(p[THAT]);	/* close parent's end of _the_ pipe */
2308         }
2309 #if !defined(HAS_FCNTL) || !defined(F_SETFD)
2310 	/* No automatic close - do it by hand */
2311 #  ifndef NOFILE
2312 #  define NOFILE 20
2313 #  endif
2314 	{
2315 	    int fd;
2316 
2317 	    for (fd = PL_maxsysfd + 1; fd < NOFILE; fd++) {
2318 		if (fd != pp[1])
2319 		    PerlLIO_close(fd);
2320 	    }
2321 	}
2322 #endif
2323 	do_aexec5(NULL, args-1, args-1+n, pp[1], did_pipes);
2324 	PerlProc__exit(1);
2325 #undef THIS
2326 #undef THAT
2327     }
2328     /* Parent */
2329     if (did_pipes)
2330 	PerlLIO_close(pp[1]);
2331     /* Keep the lower of the two fd numbers */
2332     if (p[that] < p[This]) {
2333 	PerlLIO_dup2_cloexec(p[This], p[that]);
2334 	PerlLIO_close(p[This]);
2335 	p[This] = p[that];
2336     }
2337     else
2338 	PerlLIO_close(p[that]);		/* close child's end of pipe */
2339 
2340     sv = *av_fetch(PL_fdpid,p[This],TRUE);
2341     SvUPGRADE(sv,SVt_IV);
2342     SvIV_set(sv, pid);
2343     PL_forkprocess = pid;
2344     /* If we managed to get status pipe check for exec fail */
2345     if (did_pipes && pid > 0) {
2346 	int errkid;
2347 	unsigned n = 0;
2348 
2349 	while (n < sizeof(int)) {
2350             const SSize_t n1 = PerlLIO_read(pp[0],
2351 			      (void*)(((char*)&errkid)+n),
2352 			      (sizeof(int)) - n);
2353 	    if (n1 <= 0)
2354 		break;
2355 	    n += n1;
2356 	}
2357 	PerlLIO_close(pp[0]);
2358 	did_pipes = 0;
2359 	if (n) {			/* Error */
2360 	    int pid2, status;
2361 	    PerlLIO_close(p[This]);
2362 	    if (n != sizeof(int))
2363 		Perl_croak(aTHX_ "panic: kid popen errno read, n=%u", n);
2364 	    do {
2365 		pid2 = wait4pid(pid, &status, 0);
2366 	    } while (pid2 == -1 && errno == EINTR);
2367 	    errno = errkid;		/* Propagate errno from kid */
2368 	    return NULL;
2369 	}
2370     }
2371     if (did_pipes)
2372 	 PerlLIO_close(pp[0]);
2373     return PerlIO_fdopen(p[This], mode);
2374 #else
2375 #  if defined(OS2)	/* Same, without fork()ing and all extra overhead... */
2376     return my_syspopen4(aTHX_ NULL, mode, n, args);
2377 #  elif defined(WIN32)
2378     return win32_popenlist(mode, n, args);
2379 #  else
2380     Perl_croak(aTHX_ "List form of piped open not implemented");
2381     return (PerlIO *) NULL;
2382 #  endif
2383 #endif
2384 }
2385 
2386     /* VMS' my_popen() is in VMS.c, same with OS/2 and AmigaOS 4. */
2387 #if (!defined(DOSISH) || defined(HAS_FORK)) && !defined(VMS) && !defined(__LIBCATAMOUNT__) && !defined(__amigaos4__)
2388 PerlIO *
2389 Perl_my_popen(pTHX_ const char *cmd, const char *mode)
2390 {
2391     int p[2];
2392     I32 This, that;
2393     Pid_t pid;
2394     SV *sv;
2395     const I32 doexec = !(*cmd == '-' && cmd[1] == '\0');
2396     I32 did_pipes = 0;
2397     int pp[2];
2398 
2399     PERL_ARGS_ASSERT_MY_POPEN;
2400 
2401     PERL_FLUSHALL_FOR_CHILD;
2402 #ifdef OS2
2403     if (doexec) {
2404 	return my_syspopen(aTHX_ cmd,mode);
2405     }
2406 #endif
2407     This = (*mode == 'w');
2408     that = !This;
2409     if (doexec && TAINTING_get) {
2410 	taint_env();
2411 	taint_proper("Insecure %s%s", "EXEC");
2412     }
2413     if (PerlProc_pipe_cloexec(p) < 0)
2414 	return NULL;
2415     if (doexec && PerlProc_pipe_cloexec(pp) >= 0)
2416 	did_pipes = 1;
2417     while ((pid = PerlProc_fork()) < 0) {
2418 	if (errno != EAGAIN) {
2419 	    PerlLIO_close(p[This]);
2420 	    PerlLIO_close(p[that]);
2421 	    if (did_pipes) {
2422 		PerlLIO_close(pp[0]);
2423 		PerlLIO_close(pp[1]);
2424 	    }
2425 	    if (!doexec)
2426 		Perl_croak(aTHX_ "Can't fork: %s", Strerror(errno));
2427 	    return NULL;
2428 	}
2429 	Perl_ck_warner(aTHX_ packWARN(WARN_PIPE), "Can't fork, trying again in 5 seconds");
2430 	sleep(5);
2431     }
2432     if (pid == 0) {
2433 
2434 #undef THIS
2435 #undef THAT
2436 #define THIS that
2437 #define THAT This
2438 	if (did_pipes)
2439 	    PerlLIO_close(pp[0]);
2440 	if (p[THIS] != (*mode == 'r')) {
2441 	    PerlLIO_dup2(p[THIS], *mode == 'r');
2442 	    PerlLIO_close(p[THIS]);
2443 	    if (p[THAT] != (*mode == 'r'))	/* if dup2() didn't close it */
2444 		PerlLIO_close(p[THAT]);
2445 	}
2446 	else {
2447 	    setfd_cloexec_or_inhexec_by_sysfdness(p[THIS]);
2448 	    PerlLIO_close(p[THAT]);
2449 	}
2450 #ifndef OS2
2451 	if (doexec) {
2452 #if !defined(HAS_FCNTL) || !defined(F_SETFD)
2453 #ifndef NOFILE
2454 #define NOFILE 20
2455 #endif
2456 	    {
2457 		int fd;
2458 
2459 		for (fd = PL_maxsysfd + 1; fd < NOFILE; fd++)
2460 		    if (fd != pp[1])
2461 			PerlLIO_close(fd);
2462 	    }
2463 #endif
2464 	    /* may or may not use the shell */
2465 	    do_exec3(cmd, pp[1], did_pipes);
2466 	    PerlProc__exit(1);
2467 	}
2468 #endif	/* defined OS2 */
2469 
2470 #ifdef PERLIO_USING_CRLF
2471    /* Since we circumvent IO layers when we manipulate low-level
2472       filedescriptors directly, need to manually switch to the
2473       default, binary, low-level mode; see PerlIOBuf_open(). */
2474    PerlLIO_setmode((*mode == 'r'), O_BINARY);
2475 #endif
2476 	PL_forkprocess = 0;
2477 #ifdef PERL_USES_PL_PIDSTATUS
2478 	hv_clear(PL_pidstatus);	/* we have no children */
2479 #endif
2480 	return NULL;
2481 #undef THIS
2482 #undef THAT
2483     }
2484     if (did_pipes)
2485 	PerlLIO_close(pp[1]);
2486     if (p[that] < p[This]) {
2487 	PerlLIO_dup2_cloexec(p[This], p[that]);
2488 	PerlLIO_close(p[This]);
2489 	p[This] = p[that];
2490     }
2491     else
2492 	PerlLIO_close(p[that]);
2493 
2494     sv = *av_fetch(PL_fdpid,p[This],TRUE);
2495     SvUPGRADE(sv,SVt_IV);
2496     SvIV_set(sv, pid);
2497     PL_forkprocess = pid;
2498     if (did_pipes && pid > 0) {
2499 	int errkid;
2500 	unsigned n = 0;
2501 
2502 	while (n < sizeof(int)) {
2503             const SSize_t n1 = PerlLIO_read(pp[0],
2504 			      (void*)(((char*)&errkid)+n),
2505 			      (sizeof(int)) - n);
2506 	    if (n1 <= 0)
2507 		break;
2508 	    n += n1;
2509 	}
2510 	PerlLIO_close(pp[0]);
2511 	did_pipes = 0;
2512 	if (n) {			/* Error */
2513 	    int pid2, status;
2514 	    PerlLIO_close(p[This]);
2515 	    if (n != sizeof(int))
2516 		Perl_croak(aTHX_ "panic: kid popen errno read, n=%u", n);
2517 	    do {
2518 		pid2 = wait4pid(pid, &status, 0);
2519 	    } while (pid2 == -1 && errno == EINTR);
2520 	    errno = errkid;		/* Propagate errno from kid */
2521 	    return NULL;
2522 	}
2523     }
2524     if (did_pipes)
2525 	 PerlLIO_close(pp[0]);
2526     return PerlIO_fdopen(p[This], mode);
2527 }
2528 #elif defined(DJGPP)
2529 FILE *djgpp_popen();
2530 PerlIO *
2531 Perl_my_popen(pTHX_ const char *cmd, const char *mode)
2532 {
2533     PERL_FLUSHALL_FOR_CHILD;
2534     /* Call system's popen() to get a FILE *, then import it.
2535        used 0 for 2nd parameter to PerlIO_importFILE;
2536        apparently not used
2537     */
2538     return PerlIO_importFILE(djgpp_popen(cmd, mode), 0);
2539 }
2540 #elif defined(__LIBCATAMOUNT__)
2541 PerlIO *
2542 Perl_my_popen(pTHX_ const char *cmd, const char *mode)
2543 {
2544     return NULL;
2545 }
2546 
2547 #endif /* !DOSISH */
2548 
2549 /* this is called in parent before the fork() */
2550 void
2551 Perl_atfork_lock(void)
2552 #if defined(USE_ITHREADS)
2553 #  ifdef USE_PERLIO
2554   PERL_TSA_ACQUIRE(PL_perlio_mutex)
2555 #  endif
2556 #  ifdef MYMALLOC
2557   PERL_TSA_ACQUIRE(PL_malloc_mutex)
2558 #  endif
2559   PERL_TSA_ACQUIRE(PL_op_mutex)
2560 #endif
2561 {
2562 #if defined(USE_ITHREADS)
2563     dVAR;
2564     /* locks must be held in locking order (if any) */
2565 #  ifdef USE_PERLIO
2566     MUTEX_LOCK(&PL_perlio_mutex);
2567 #  endif
2568 #  ifdef MYMALLOC
2569     MUTEX_LOCK(&PL_malloc_mutex);
2570 #  endif
2571     OP_REFCNT_LOCK;
2572 #endif
2573 }
2574 
2575 /* this is called in both parent and child after the fork() */
2576 void
2577 Perl_atfork_unlock(void)
2578 #if defined(USE_ITHREADS)
2579 #  ifdef USE_PERLIO
2580   PERL_TSA_RELEASE(PL_perlio_mutex)
2581 #  endif
2582 #  ifdef MYMALLOC
2583   PERL_TSA_RELEASE(PL_malloc_mutex)
2584 #  endif
2585   PERL_TSA_RELEASE(PL_op_mutex)
2586 #endif
2587 {
2588 #if defined(USE_ITHREADS)
2589     dVAR;
2590     /* locks must be released in same order as in atfork_lock() */
2591 #  ifdef USE_PERLIO
2592     MUTEX_UNLOCK(&PL_perlio_mutex);
2593 #  endif
2594 #  ifdef MYMALLOC
2595     MUTEX_UNLOCK(&PL_malloc_mutex);
2596 #  endif
2597     OP_REFCNT_UNLOCK;
2598 #endif
2599 }
2600 
2601 Pid_t
2602 Perl_my_fork(void)
2603 {
2604 #if defined(HAS_FORK)
2605     Pid_t pid;
2606 #if defined(USE_ITHREADS) && !defined(HAS_PTHREAD_ATFORK)
2607     atfork_lock();
2608     pid = fork();
2609     atfork_unlock();
2610 #else
2611     /* atfork_lock() and atfork_unlock() are installed as pthread_atfork()
2612      * handlers elsewhere in the code */
2613     pid = fork();
2614 #endif
2615     return pid;
2616 #elif defined(__amigaos4__)
2617     return amigaos_fork();
2618 #else
2619     /* this "canna happen" since nothing should be calling here if !HAS_FORK */
2620     Perl_croak_nocontext("fork() not available");
2621     return 0;
2622 #endif /* HAS_FORK */
2623 }
2624 
2625 #ifndef HAS_DUP2
2626 int
2627 dup2(int oldfd, int newfd)
2628 {
2629 #if defined(HAS_FCNTL) && defined(F_DUPFD)
2630     if (oldfd == newfd)
2631 	return oldfd;
2632     PerlLIO_close(newfd);
2633     return fcntl(oldfd, F_DUPFD, newfd);
2634 #else
2635 #define DUP2_MAX_FDS 256
2636     int fdtmp[DUP2_MAX_FDS];
2637     I32 fdx = 0;
2638     int fd;
2639 
2640     if (oldfd == newfd)
2641 	return oldfd;
2642     PerlLIO_close(newfd);
2643     /* good enough for low fd's... */
2644     while ((fd = PerlLIO_dup(oldfd)) != newfd && fd >= 0) {
2645 	if (fdx >= DUP2_MAX_FDS) {
2646 	    PerlLIO_close(fd);
2647 	    fd = -1;
2648 	    break;
2649 	}
2650 	fdtmp[fdx++] = fd;
2651     }
2652     while (fdx > 0)
2653 	PerlLIO_close(fdtmp[--fdx]);
2654     return fd;
2655 #endif
2656 }
2657 #endif
2658 
2659 #ifndef PERL_MICRO
2660 #ifdef HAS_SIGACTION
2661 
2662 Sighandler_t
2663 Perl_rsignal(pTHX_ int signo, Sighandler_t handler)
2664 {
2665     struct sigaction act, oact;
2666 
2667 #ifdef USE_ITHREADS
2668     dVAR;
2669     /* only "parent" interpreter can diddle signals */
2670     if (PL_curinterp != aTHX)
2671 	return (Sighandler_t) SIG_ERR;
2672 #endif
2673 
2674     act.sa_handler = (void(*)(int))handler;
2675     sigemptyset(&act.sa_mask);
2676     act.sa_flags = 0;
2677 #ifdef SA_RESTART
2678     if (PL_signals & PERL_SIGNALS_UNSAFE_FLAG)
2679         act.sa_flags |= SA_RESTART;	/* SVR4, 4.3+BSD */
2680 #endif
2681 #if defined(SA_NOCLDWAIT) && !defined(BSDish) /* See [perl #18849] */
2682     if (signo == SIGCHLD && handler == (Sighandler_t) SIG_IGN)
2683 	act.sa_flags |= SA_NOCLDWAIT;
2684 #endif
2685     if (sigaction(signo, &act, &oact) == -1)
2686     	return (Sighandler_t) SIG_ERR;
2687     else
2688     	return (Sighandler_t) oact.sa_handler;
2689 }
2690 
2691 Sighandler_t
2692 Perl_rsignal_state(pTHX_ int signo)
2693 {
2694     struct sigaction oact;
2695     PERL_UNUSED_CONTEXT;
2696 
2697     if (sigaction(signo, (struct sigaction *)NULL, &oact) == -1)
2698 	return (Sighandler_t) SIG_ERR;
2699     else
2700 	return (Sighandler_t) oact.sa_handler;
2701 }
2702 
2703 int
2704 Perl_rsignal_save(pTHX_ int signo, Sighandler_t handler, Sigsave_t *save)
2705 {
2706 #ifdef USE_ITHREADS
2707     dVAR;
2708 #endif
2709     struct sigaction act;
2710 
2711     PERL_ARGS_ASSERT_RSIGNAL_SAVE;
2712 
2713 #ifdef USE_ITHREADS
2714     /* only "parent" interpreter can diddle signals */
2715     if (PL_curinterp != aTHX)
2716 	return -1;
2717 #endif
2718 
2719     act.sa_handler = (void(*)(int))handler;
2720     sigemptyset(&act.sa_mask);
2721     act.sa_flags = 0;
2722 #ifdef SA_RESTART
2723     if (PL_signals & PERL_SIGNALS_UNSAFE_FLAG)
2724         act.sa_flags |= SA_RESTART;	/* SVR4, 4.3+BSD */
2725 #endif
2726 #if defined(SA_NOCLDWAIT) && !defined(BSDish) /* See [perl #18849] */
2727     if (signo == SIGCHLD && handler == (Sighandler_t) SIG_IGN)
2728 	act.sa_flags |= SA_NOCLDWAIT;
2729 #endif
2730     return sigaction(signo, &act, save);
2731 }
2732 
2733 int
2734 Perl_rsignal_restore(pTHX_ int signo, Sigsave_t *save)
2735 {
2736 #ifdef USE_ITHREADS
2737     dVAR;
2738 #endif
2739     PERL_UNUSED_CONTEXT;
2740 #ifdef USE_ITHREADS
2741     /* only "parent" interpreter can diddle signals */
2742     if (PL_curinterp != aTHX)
2743 	return -1;
2744 #endif
2745 
2746     return sigaction(signo, save, (struct sigaction *)NULL);
2747 }
2748 
2749 #else /* !HAS_SIGACTION */
2750 
2751 Sighandler_t
2752 Perl_rsignal(pTHX_ int signo, Sighandler_t handler)
2753 {
2754 #if defined(USE_ITHREADS) && !defined(WIN32)
2755     /* only "parent" interpreter can diddle signals */
2756     if (PL_curinterp != aTHX)
2757 	return (Sighandler_t) SIG_ERR;
2758 #endif
2759 
2760     return PerlProc_signal(signo, handler);
2761 }
2762 
2763 static Signal_t
2764 sig_trap(int signo)
2765 {
2766     dVAR;
2767     PL_sig_trapped++;
2768 }
2769 
2770 Sighandler_t
2771 Perl_rsignal_state(pTHX_ int signo)
2772 {
2773     dVAR;
2774     Sighandler_t oldsig;
2775 
2776 #if defined(USE_ITHREADS) && !defined(WIN32)
2777     /* only "parent" interpreter can diddle signals */
2778     if (PL_curinterp != aTHX)
2779 	return (Sighandler_t) SIG_ERR;
2780 #endif
2781 
2782     PL_sig_trapped = 0;
2783     oldsig = PerlProc_signal(signo, sig_trap);
2784     PerlProc_signal(signo, oldsig);
2785     if (PL_sig_trapped)
2786 	PerlProc_kill(PerlProc_getpid(), signo);
2787     return oldsig;
2788 }
2789 
2790 int
2791 Perl_rsignal_save(pTHX_ int signo, Sighandler_t handler, Sigsave_t *save)
2792 {
2793 #if defined(USE_ITHREADS) && !defined(WIN32)
2794     /* only "parent" interpreter can diddle signals */
2795     if (PL_curinterp != aTHX)
2796 	return -1;
2797 #endif
2798     *save = PerlProc_signal(signo, handler);
2799     return (*save == (Sighandler_t) SIG_ERR) ? -1 : 0;
2800 }
2801 
2802 int
2803 Perl_rsignal_restore(pTHX_ int signo, Sigsave_t *save)
2804 {
2805 #if defined(USE_ITHREADS) && !defined(WIN32)
2806     /* only "parent" interpreter can diddle signals */
2807     if (PL_curinterp != aTHX)
2808 	return -1;
2809 #endif
2810     return (PerlProc_signal(signo, *save) == (Sighandler_t) SIG_ERR) ? -1 : 0;
2811 }
2812 
2813 #endif /* !HAS_SIGACTION */
2814 #endif /* !PERL_MICRO */
2815 
2816     /* VMS' my_pclose() is in VMS.c; same with OS/2 */
2817 #if (!defined(DOSISH) || defined(HAS_FORK)) && !defined(VMS) && !defined(__LIBCATAMOUNT__) && !defined(__amigaos4__)
2818 I32
2819 Perl_my_pclose(pTHX_ PerlIO *ptr)
2820 {
2821     int status;
2822     SV **svp;
2823     Pid_t pid;
2824     Pid_t pid2 = 0;
2825     bool close_failed;
2826     dSAVEDERRNO;
2827     const int fd = PerlIO_fileno(ptr);
2828     bool should_wait;
2829 
2830     svp = av_fetch(PL_fdpid,fd,TRUE);
2831     pid = (SvTYPE(*svp) == SVt_IV) ? SvIVX(*svp) : -1;
2832     SvREFCNT_dec(*svp);
2833     *svp = NULL;
2834 
2835 #if defined(USE_PERLIO)
2836     /* Find out whether the refcount is low enough for us to wait for the
2837        child proc without blocking. */
2838     should_wait = PerlIOUnix_refcnt(fd) == 1 && pid > 0;
2839 #else
2840     should_wait = pid > 0;
2841 #endif
2842 
2843 #ifdef OS2
2844     if (pid == -1) {			/* Opened by popen. */
2845 	return my_syspclose(ptr);
2846     }
2847 #endif
2848     close_failed = (PerlIO_close(ptr) == EOF);
2849     SAVE_ERRNO;
2850     if (should_wait) do {
2851 	pid2 = wait4pid(pid, &status, 0);
2852     } while (pid2 == -1 && errno == EINTR);
2853     if (close_failed) {
2854 	RESTORE_ERRNO;
2855 	return -1;
2856     }
2857     return(
2858       should_wait
2859        ? pid2 < 0 ? pid2 : status == 0 ? 0 : (errno = 0, status)
2860        : 0
2861     );
2862 }
2863 #elif defined(__LIBCATAMOUNT__)
2864 I32
2865 Perl_my_pclose(pTHX_ PerlIO *ptr)
2866 {
2867     return -1;
2868 }
2869 #endif /* !DOSISH */
2870 
2871 #if  (!defined(DOSISH) || defined(OS2) || defined(WIN32) || defined(NETWARE)) && !defined(__LIBCATAMOUNT__)
2872 I32
2873 Perl_wait4pid(pTHX_ Pid_t pid, int *statusp, int flags)
2874 {
2875     I32 result = 0;
2876     PERL_ARGS_ASSERT_WAIT4PID;
2877 #ifdef PERL_USES_PL_PIDSTATUS
2878     if (!pid) {
2879         /* PERL_USES_PL_PIDSTATUS is only defined when neither
2880            waitpid() nor wait4() is available, or on OS/2, which
2881            doesn't appear to support waiting for a progress group
2882            member, so we can only treat a 0 pid as an unknown child.
2883         */
2884         errno = ECHILD;
2885         return -1;
2886     }
2887     {
2888 	if (pid > 0) {
2889 	    /* The keys in PL_pidstatus are now the raw 4 (or 8) bytes of the
2890 	       pid, rather than a string form.  */
2891 	    SV * const * const svp = hv_fetch(PL_pidstatus,(const char*) &pid,sizeof(Pid_t),FALSE);
2892 	    if (svp && *svp != &PL_sv_undef) {
2893 		*statusp = SvIVX(*svp);
2894 		(void)hv_delete(PL_pidstatus,(const char*) &pid,sizeof(Pid_t),
2895 				G_DISCARD);
2896 		return pid;
2897 	    }
2898 	}
2899 	else {
2900 	    HE *entry;
2901 
2902 	    hv_iterinit(PL_pidstatus);
2903 	    if ((entry = hv_iternext(PL_pidstatus))) {
2904 		SV * const sv = hv_iterval(PL_pidstatus,entry);
2905 		I32 len;
2906 		const char * const spid = hv_iterkey(entry,&len);
2907 
2908 		assert (len == sizeof(Pid_t));
2909 		memcpy((char *)&pid, spid, len);
2910 		*statusp = SvIVX(sv);
2911 		/* The hash iterator is currently on this entry, so simply
2912 		   calling hv_delete would trigger the lazy delete, which on
2913 		   aggregate does more work, because next call to hv_iterinit()
2914 		   would spot the flag, and have to call the delete routine,
2915 		   while in the meantime any new entries can't re-use that
2916 		   memory.  */
2917 		hv_iterinit(PL_pidstatus);
2918 		(void)hv_delete(PL_pidstatus,spid,len,G_DISCARD);
2919 		return pid;
2920 	    }
2921 	}
2922     }
2923 #endif
2924 #ifdef HAS_WAITPID
2925 #  ifdef HAS_WAITPID_RUNTIME
2926     if (!HAS_WAITPID_RUNTIME)
2927 	goto hard_way;
2928 #  endif
2929     result = PerlProc_waitpid(pid,statusp,flags);
2930     goto finish;
2931 #endif
2932 #if !defined(HAS_WAITPID) && defined(HAS_WAIT4)
2933     result = wait4(pid,statusp,flags,NULL);
2934     goto finish;
2935 #endif
2936 #ifdef PERL_USES_PL_PIDSTATUS
2937 #if defined(HAS_WAITPID) && defined(HAS_WAITPID_RUNTIME)
2938   hard_way:
2939 #endif
2940     {
2941 	if (flags)
2942 	    Perl_croak(aTHX_ "Can't do waitpid with flags");
2943 	else {
2944 	    while ((result = PerlProc_wait(statusp)) != pid && pid > 0 && result >= 0)
2945 		pidgone(result,*statusp);
2946 	    if (result < 0)
2947 		*statusp = -1;
2948 	}
2949     }
2950 #endif
2951 #if defined(HAS_WAITPID) || defined(HAS_WAIT4)
2952   finish:
2953 #endif
2954     if (result < 0 && errno == EINTR) {
2955 	PERL_ASYNC_CHECK();
2956 	errno = EINTR; /* reset in case a signal handler changed $! */
2957     }
2958     return result;
2959 }
2960 #endif /* !DOSISH || OS2 || WIN32 || NETWARE */
2961 
2962 #ifdef PERL_USES_PL_PIDSTATUS
2963 void
2964 S_pidgone(pTHX_ Pid_t pid, int status)
2965 {
2966     SV *sv;
2967 
2968     sv = *hv_fetch(PL_pidstatus,(const char*)&pid,sizeof(Pid_t),TRUE);
2969     SvUPGRADE(sv,SVt_IV);
2970     SvIV_set(sv, status);
2971     return;
2972 }
2973 #endif
2974 
2975 #if defined(OS2)
2976 int pclose();
2977 #ifdef HAS_FORK
2978 int					/* Cannot prototype with I32
2979 					   in os2ish.h. */
2980 my_syspclose(PerlIO *ptr)
2981 #else
2982 I32
2983 Perl_my_pclose(pTHX_ PerlIO *ptr)
2984 #endif
2985 {
2986     /* Needs work for PerlIO ! */
2987     FILE * const f = PerlIO_findFILE(ptr);
2988     const I32 result = pclose(f);
2989     PerlIO_releaseFILE(ptr,f);
2990     return result;
2991 }
2992 #endif
2993 
2994 #if defined(DJGPP)
2995 int djgpp_pclose();
2996 I32
2997 Perl_my_pclose(pTHX_ PerlIO *ptr)
2998 {
2999     /* Needs work for PerlIO ! */
3000     FILE * const f = PerlIO_findFILE(ptr);
3001     I32 result = djgpp_pclose(f);
3002     result = (result << 8) & 0xff00;
3003     PerlIO_releaseFILE(ptr,f);
3004     return result;
3005 }
3006 #endif
3007 
3008 #define PERL_REPEATCPY_LINEAR 4
3009 void
3010 Perl_repeatcpy(char *to, const char *from, I32 len, IV count)
3011 {
3012     PERL_ARGS_ASSERT_REPEATCPY;
3013 
3014     assert(len >= 0);
3015 
3016     if (count < 0)
3017 	croak_memory_wrap();
3018 
3019     if (len == 1)
3020 	memset(to, *from, count);
3021     else if (count) {
3022 	char *p = to;
3023 	IV items, linear, half;
3024 
3025 	linear = count < PERL_REPEATCPY_LINEAR ? count : PERL_REPEATCPY_LINEAR;
3026 	for (items = 0; items < linear; ++items) {
3027 	    const char *q = from;
3028 	    IV todo;
3029 	    for (todo = len; todo > 0; todo--)
3030 		*p++ = *q++;
3031         }
3032 
3033 	half = count / 2;
3034 	while (items <= half) {
3035 	    IV size = items * len;
3036 	    memcpy(p, to, size);
3037 	    p     += size;
3038 	    items *= 2;
3039 	}
3040 
3041 	if (count > items)
3042 	    memcpy(p, to, (count - items) * len);
3043     }
3044 }
3045 
3046 #ifndef HAS_RENAME
3047 I32
3048 Perl_same_dirent(pTHX_ const char *a, const char *b)
3049 {
3050     char *fa = strrchr(a,'/');
3051     char *fb = strrchr(b,'/');
3052     Stat_t tmpstatbuf1;
3053     Stat_t tmpstatbuf2;
3054     SV * const tmpsv = sv_newmortal();
3055 
3056     PERL_ARGS_ASSERT_SAME_DIRENT;
3057 
3058     if (fa)
3059 	fa++;
3060     else
3061 	fa = a;
3062     if (fb)
3063 	fb++;
3064     else
3065 	fb = b;
3066     if (strNE(a,b))
3067 	return FALSE;
3068     if (fa == a)
3069 	sv_setpvs(tmpsv, ".");
3070     else
3071 	sv_setpvn(tmpsv, a, fa - a);
3072     if (PerlLIO_stat(SvPVX_const(tmpsv), &tmpstatbuf1) < 0)
3073 	return FALSE;
3074     if (fb == b)
3075 	sv_setpvs(tmpsv, ".");
3076     else
3077 	sv_setpvn(tmpsv, b, fb - b);
3078     if (PerlLIO_stat(SvPVX_const(tmpsv), &tmpstatbuf2) < 0)
3079 	return FALSE;
3080     return tmpstatbuf1.st_dev == tmpstatbuf2.st_dev &&
3081 	   tmpstatbuf1.st_ino == tmpstatbuf2.st_ino;
3082 }
3083 #endif /* !HAS_RENAME */
3084 
3085 char*
3086 Perl_find_script(pTHX_ const char *scriptname, bool dosearch,
3087 		 const char *const *const search_ext, I32 flags)
3088 {
3089     const char *xfound = NULL;
3090     char *xfailed = NULL;
3091     char tmpbuf[MAXPATHLEN];
3092     char *s;
3093     I32 len = 0;
3094     int retval;
3095     char *bufend;
3096 #if defined(DOSISH) && !defined(OS2)
3097 #  define SEARCH_EXTS ".bat", ".cmd", NULL
3098 #  define MAX_EXT_LEN 4
3099 #endif
3100 #ifdef OS2
3101 #  define SEARCH_EXTS ".cmd", ".btm", ".bat", ".pl", NULL
3102 #  define MAX_EXT_LEN 4
3103 #endif
3104 #ifdef VMS
3105 #  define SEARCH_EXTS ".pl", ".com", NULL
3106 #  define MAX_EXT_LEN 4
3107 #endif
3108     /* additional extensions to try in each dir if scriptname not found */
3109 #ifdef SEARCH_EXTS
3110     static const char *const exts[] = { SEARCH_EXTS };
3111     const char *const *const ext = search_ext ? search_ext : exts;
3112     int extidx = 0, i = 0;
3113     const char *curext = NULL;
3114 #else
3115     PERL_UNUSED_ARG(search_ext);
3116 #  define MAX_EXT_LEN 0
3117 #endif
3118 
3119     PERL_ARGS_ASSERT_FIND_SCRIPT;
3120 
3121     /*
3122      * If dosearch is true and if scriptname does not contain path
3123      * delimiters, search the PATH for scriptname.
3124      *
3125      * If SEARCH_EXTS is also defined, will look for each
3126      * scriptname{SEARCH_EXTS} whenever scriptname is not found
3127      * while searching the PATH.
3128      *
3129      * Assuming SEARCH_EXTS is C<".foo",".bar",NULL>, PATH search
3130      * proceeds as follows:
3131      *   If DOSISH or VMSISH:
3132      *     + look for ./scriptname{,.foo,.bar}
3133      *     + search the PATH for scriptname{,.foo,.bar}
3134      *
3135      *   If !DOSISH:
3136      *     + look *only* in the PATH for scriptname{,.foo,.bar} (note
3137      *       this will not look in '.' if it's not in the PATH)
3138      */
3139     tmpbuf[0] = '\0';
3140 
3141 #ifdef VMS
3142 #  ifdef ALWAYS_DEFTYPES
3143     len = strlen(scriptname);
3144     if (!(len == 1 && *scriptname == '-') && scriptname[len-1] != ':') {
3145 	int idx = 0, deftypes = 1;
3146 	bool seen_dot = 1;
3147 
3148 	const int hasdir = !dosearch || (strpbrk(scriptname,":[</") != NULL);
3149 #  else
3150     if (dosearch) {
3151 	int idx = 0, deftypes = 1;
3152 	bool seen_dot = 1;
3153 
3154 	const int hasdir = (strpbrk(scriptname,":[</") != NULL);
3155 #  endif
3156 	/* The first time through, just add SEARCH_EXTS to whatever we
3157 	 * already have, so we can check for default file types. */
3158 	while (deftypes ||
3159 	       (!hasdir && my_trnlnm("DCL$PATH",tmpbuf,idx++)) )
3160 	{
3161 	    Stat_t statbuf;
3162 	    if (deftypes) {
3163 		deftypes = 0;
3164 		*tmpbuf = '\0';
3165 	    }
3166 	    if ((strlen(tmpbuf) + strlen(scriptname)
3167 		 + MAX_EXT_LEN) >= sizeof tmpbuf)
3168 		continue;	/* don't search dir with too-long name */
3169 	    my_strlcat(tmpbuf, scriptname, sizeof(tmpbuf));
3170 #else  /* !VMS */
3171 
3172 #ifdef DOSISH
3173     if (strEQ(scriptname, "-"))
3174  	dosearch = 0;
3175     if (dosearch) {		/* Look in '.' first. */
3176 	const char *cur = scriptname;
3177 #ifdef SEARCH_EXTS
3178 	if ((curext = strrchr(scriptname,'.')))	/* possible current ext */
3179 	    while (ext[i])
3180 		if (strEQ(ext[i++],curext)) {
3181 		    extidx = -1;		/* already has an ext */
3182 		    break;
3183 		}
3184 	do {
3185 #endif
3186 	    DEBUG_p(PerlIO_printf(Perl_debug_log,
3187 				  "Looking for %s\n",cur));
3188 	    {
3189 		Stat_t statbuf;
3190 		if (PerlLIO_stat(cur,&statbuf) >= 0
3191 		    && !S_ISDIR(statbuf.st_mode)) {
3192 		    dosearch = 0;
3193 		    scriptname = cur;
3194 #ifdef SEARCH_EXTS
3195 		    break;
3196 #endif
3197 		}
3198 	    }
3199 #ifdef SEARCH_EXTS
3200 	    if (cur == scriptname) {
3201 		len = strlen(scriptname);
3202 		if (len+MAX_EXT_LEN+1 >= sizeof(tmpbuf))
3203 		    break;
3204 		my_strlcpy(tmpbuf, scriptname, sizeof(tmpbuf));
3205 		cur = tmpbuf;
3206 	    }
3207 	} while (extidx >= 0 && ext[extidx]	/* try an extension? */
3208 		 && my_strlcpy(tmpbuf+len, ext[extidx++], sizeof(tmpbuf) - len));
3209 #endif
3210     }
3211 #endif
3212 
3213     if (dosearch && !strchr(scriptname, '/')
3214 #ifdef DOSISH
3215 		 && !strchr(scriptname, '\\')
3216 #endif
3217 		 && (s = PerlEnv_getenv("PATH")))
3218     {
3219 	bool seen_dot = 0;
3220 
3221 	bufend = s + strlen(s);
3222 	while (s < bufend) {
3223 	    Stat_t statbuf;
3224 #  ifdef DOSISH
3225 	    for (len = 0; *s
3226 		    && *s != ';'; len++, s++) {
3227 		if (len < sizeof tmpbuf)
3228 		    tmpbuf[len] = *s;
3229 	    }
3230 	    if (len < sizeof tmpbuf)
3231 		tmpbuf[len] = '\0';
3232 #  else
3233 	    s = delimcpy_no_escape(tmpbuf, tmpbuf + sizeof tmpbuf, s, bufend,
3234                                    ':', &len);
3235 #  endif
3236 	    if (s < bufend)
3237 		s++;
3238 	    if (len + 1 + strlen(scriptname) + MAX_EXT_LEN >= sizeof tmpbuf)
3239 		continue;	/* don't search dir with too-long name */
3240 	    if (len
3241 #  ifdef DOSISH
3242 		&& tmpbuf[len - 1] != '/'
3243 		&& tmpbuf[len - 1] != '\\'
3244 #  endif
3245 	       )
3246 		tmpbuf[len++] = '/';
3247 	    if (len == 2 && tmpbuf[0] == '.')
3248 		seen_dot = 1;
3249 	    (void)my_strlcpy(tmpbuf + len, scriptname, sizeof(tmpbuf) - len);
3250 #endif  /* !VMS */
3251 
3252 #ifdef SEARCH_EXTS
3253 	    len = strlen(tmpbuf);
3254 	    if (extidx > 0)	/* reset after previous loop */
3255 		extidx = 0;
3256 	    do {
3257 #endif
3258 	    	DEBUG_p(PerlIO_printf(Perl_debug_log, "Looking for %s\n",tmpbuf));
3259 		retval = PerlLIO_stat(tmpbuf,&statbuf);
3260 		if (S_ISDIR(statbuf.st_mode)) {
3261 		    retval = -1;
3262 		}
3263 #ifdef SEARCH_EXTS
3264 	    } while (  retval < 0		/* not there */
3265 		    && extidx>=0 && ext[extidx]	/* try an extension? */
3266 		    && my_strlcpy(tmpbuf+len, ext[extidx++], sizeof(tmpbuf) - len)
3267 		);
3268 #endif
3269 	    if (retval < 0)
3270 		continue;
3271 	    if (S_ISREG(statbuf.st_mode)
3272 		&& cando(S_IRUSR,TRUE,&statbuf)
3273 #if !defined(DOSISH)
3274 		&& cando(S_IXUSR,TRUE,&statbuf)
3275 #endif
3276 		)
3277 	    {
3278 		xfound = tmpbuf;		/* bingo! */
3279 		break;
3280 	    }
3281 	    if (!xfailed)
3282 		xfailed = savepv(tmpbuf);
3283 	}
3284 #ifndef DOSISH
3285 	{
3286 	    Stat_t statbuf;
3287 	    if (!xfound && !seen_dot && !xfailed &&
3288 		(PerlLIO_stat(scriptname,&statbuf) < 0
3289 		 || S_ISDIR(statbuf.st_mode)))
3290 #endif
3291 		seen_dot = 1;			/* Disable message. */
3292 #ifndef DOSISH
3293 	}
3294 #endif
3295 	if (!xfound) {
3296 	    if (flags & 1) {			/* do or die? */
3297 		/* diag_listed_as: Can't execute %s */
3298 		Perl_croak(aTHX_ "Can't %s %s%s%s",
3299 		      (xfailed ? "execute" : "find"),
3300 		      (xfailed ? xfailed : scriptname),
3301 		      (xfailed ? "" : " on PATH"),
3302 		      (xfailed || seen_dot) ? "" : ", '.' not in PATH");
3303 	    }
3304 	    scriptname = NULL;
3305 	}
3306 	Safefree(xfailed);
3307 	scriptname = xfound;
3308     }
3309     return (scriptname ? savepv(scriptname) : NULL);
3310 }
3311 
3312 #ifndef PERL_GET_CONTEXT_DEFINED
3313 
3314 void *
3315 Perl_get_context(void)
3316 {
3317 #if defined(USE_ITHREADS)
3318     dVAR;
3319 #  ifdef OLD_PTHREADS_API
3320     pthread_addr_t t;
3321     int error = pthread_getspecific(PL_thr_key, &t)
3322     if (error)
3323 	Perl_croak_nocontext("panic: pthread_getspecific, error=%d", error);
3324     return (void*)t;
3325 #  elif defined(I_MACH_CTHREADS)
3326     return (void*)cthread_data(cthread_self());
3327 #  else
3328     return (void*)PTHREAD_GETSPECIFIC(PL_thr_key);
3329 #  endif
3330 #else
3331     return (void*)NULL;
3332 #endif
3333 }
3334 
3335 void
3336 Perl_set_context(void *t)
3337 {
3338 #if defined(USE_ITHREADS)
3339     dVAR;
3340 #endif
3341     PERL_ARGS_ASSERT_SET_CONTEXT;
3342 #if defined(USE_ITHREADS)
3343 #  ifdef I_MACH_CTHREADS
3344     cthread_set_data(cthread_self(), t);
3345 #  else
3346     {
3347 	const int error = pthread_setspecific(PL_thr_key, t);
3348 	if (error)
3349 	    Perl_croak_nocontext("panic: pthread_setspecific, error=%d", error);
3350     }
3351 #  endif
3352 #else
3353     PERL_UNUSED_ARG(t);
3354 #endif
3355 }
3356 
3357 #endif /* !PERL_GET_CONTEXT_DEFINED */
3358 
3359 #if defined(PERL_GLOBAL_STRUCT) && !defined(PERL_GLOBAL_STRUCT_PRIVATE)
3360 struct perl_vars *
3361 Perl_GetVars(pTHX)
3362 {
3363     PERL_UNUSED_CONTEXT;
3364     return &PL_Vars;
3365 }
3366 #endif
3367 
3368 char **
3369 Perl_get_op_names(pTHX)
3370 {
3371     PERL_UNUSED_CONTEXT;
3372     return (char **)PL_op_name;
3373 }
3374 
3375 char **
3376 Perl_get_op_descs(pTHX)
3377 {
3378     PERL_UNUSED_CONTEXT;
3379     return (char **)PL_op_desc;
3380 }
3381 
3382 const char *
3383 Perl_get_no_modify(pTHX)
3384 {
3385     PERL_UNUSED_CONTEXT;
3386     return PL_no_modify;
3387 }
3388 
3389 U32 *
3390 Perl_get_opargs(pTHX)
3391 {
3392     PERL_UNUSED_CONTEXT;
3393     return (U32 *)PL_opargs;
3394 }
3395 
3396 PPADDR_t*
3397 Perl_get_ppaddr(pTHX)
3398 {
3399     dVAR;
3400     PERL_UNUSED_CONTEXT;
3401     return (PPADDR_t*)PL_ppaddr;
3402 }
3403 
3404 #ifndef HAS_GETENV_LEN
3405 char *
3406 Perl_getenv_len(pTHX_ const char *env_elem, unsigned long *len)
3407 {
3408     char * const env_trans = PerlEnv_getenv(env_elem);
3409     PERL_UNUSED_CONTEXT;
3410     PERL_ARGS_ASSERT_GETENV_LEN;
3411     if (env_trans)
3412 	*len = strlen(env_trans);
3413     return env_trans;
3414 }
3415 #endif
3416 
3417 
3418 MGVTBL*
3419 Perl_get_vtbl(pTHX_ int vtbl_id)
3420 {
3421     PERL_UNUSED_CONTEXT;
3422 
3423     return (vtbl_id < 0 || vtbl_id >= magic_vtable_max)
3424 	? NULL : (MGVTBL*)PL_magic_vtables + vtbl_id;
3425 }
3426 
3427 I32
3428 Perl_my_fflush_all(pTHX)
3429 {
3430 #if defined(USE_PERLIO) || defined(FFLUSH_NULL)
3431     return PerlIO_flush(NULL);
3432 #else
3433 # if defined(HAS__FWALK)
3434     extern int fflush(FILE *);
3435     /* undocumented, unprototyped, but very useful BSDism */
3436     extern void _fwalk(int (*)(FILE *));
3437     _fwalk(&fflush);
3438     return 0;
3439 # else
3440 #  if defined(FFLUSH_ALL) && defined(HAS_STDIO_STREAM_ARRAY)
3441     long open_max = -1;
3442 #   ifdef PERL_FFLUSH_ALL_FOPEN_MAX
3443     open_max = PERL_FFLUSH_ALL_FOPEN_MAX;
3444 #   elif defined(HAS_SYSCONF) && defined(_SC_OPEN_MAX)
3445     open_max = sysconf(_SC_OPEN_MAX);
3446 #   elif defined(FOPEN_MAX)
3447     open_max = FOPEN_MAX;
3448 #   elif defined(OPEN_MAX)
3449     open_max = OPEN_MAX;
3450 #   elif defined(_NFILE)
3451     open_max = _NFILE;
3452 #   endif
3453     if (open_max > 0) {
3454       long i;
3455       for (i = 0; i < open_max; i++)
3456 	    if (STDIO_STREAM_ARRAY[i]._file >= 0 &&
3457 		STDIO_STREAM_ARRAY[i]._file < open_max &&
3458 		STDIO_STREAM_ARRAY[i]._flag)
3459 		PerlIO_flush(&STDIO_STREAM_ARRAY[i]);
3460       return 0;
3461     }
3462 #  endif
3463     SETERRNO(EBADF,RMS_IFI);
3464     return EOF;
3465 # endif
3466 #endif
3467 }
3468 
3469 void
3470 Perl_report_wrongway_fh(pTHX_ const GV *gv, const char have)
3471 {
3472     if (ckWARN(WARN_IO)) {
3473         HEK * const name
3474            = gv && (isGV_with_GP(gv))
3475                 ? GvENAME_HEK((gv))
3476                 : NULL;
3477 	const char * const direction = have == '>' ? "out" : "in";
3478 
3479 	if (name && HEK_LEN(name))
3480 	    Perl_warner(aTHX_ packWARN(WARN_IO),
3481 			"Filehandle %" HEKf " opened only for %sput",
3482 			HEKfARG(name), direction);
3483 	else
3484 	    Perl_warner(aTHX_ packWARN(WARN_IO),
3485 			"Filehandle opened only for %sput", direction);
3486     }
3487 }
3488 
3489 void
3490 Perl_report_evil_fh(pTHX_ const GV *gv)
3491 {
3492     const IO *io = gv ? GvIO(gv) : NULL;
3493     const PERL_BITFIELD16 op = PL_op->op_type;
3494     const char *vile;
3495     I32 warn_type;
3496 
3497     if (io && IoTYPE(io) == IoTYPE_CLOSED) {
3498 	vile = "closed";
3499 	warn_type = WARN_CLOSED;
3500     }
3501     else {
3502 	vile = "unopened";
3503 	warn_type = WARN_UNOPENED;
3504     }
3505 
3506     if (ckWARN(warn_type)) {
3507         SV * const name
3508             = gv && isGV_with_GP(gv) && GvENAMELEN(gv) ?
3509                                      sv_2mortal(newSVhek(GvENAME_HEK(gv))) : NULL;
3510 	const char * const pars =
3511 	    (const char *)(OP_IS_FILETEST(op) ? "" : "()");
3512 	const char * const func =
3513 	    (const char *)
3514 	    (op == OP_READLINE || op == OP_RCATLINE
3515 				 ? "readline"  :	/* "<HANDLE>" not nice */
3516 	     op == OP_LEAVEWRITE ? "write" :		/* "write exit" not nice */
3517 	     PL_op_desc[op]);
3518 	const char * const type =
3519 	    (const char *)
3520 	    (OP_IS_SOCKET(op) || (io && IoTYPE(io) == IoTYPE_SOCKET)
3521 	     ? "socket" : "filehandle");
3522 	const bool have_name = name && SvCUR(name);
3523 	Perl_warner(aTHX_ packWARN(warn_type),
3524 		   "%s%s on %s %s%s%" SVf, func, pars, vile, type,
3525 		    have_name ? " " : "",
3526 		    SVfARG(have_name ? name : &PL_sv_no));
3527 	if (io && IoDIRP(io) && !(IoFLAGS(io) & IOf_FAKE_DIRP))
3528 		Perl_warner(
3529 			    aTHX_ packWARN(warn_type),
3530 			"\t(Are you trying to call %s%s on dirhandle%s%" SVf "?)\n",
3531 			func, pars, have_name ? " " : "",
3532 			SVfARG(have_name ? name : &PL_sv_no)
3533 			    );
3534     }
3535 }
3536 
3537 /* To workaround core dumps from the uninitialised tm_zone we get the
3538  * system to give us a reasonable struct to copy.  This fix means that
3539  * strftime uses the tm_zone and tm_gmtoff values returned by
3540  * localtime(time()). That should give the desired result most of the
3541  * time. But probably not always!
3542  *
3543  * This does not address tzname aspects of NETaa14816.
3544  *
3545  */
3546 
3547 #ifdef __GLIBC__
3548 # ifndef STRUCT_TM_HASZONE
3549 #    define STRUCT_TM_HASZONE
3550 # endif
3551 #endif
3552 
3553 #ifdef STRUCT_TM_HASZONE /* Backward compat */
3554 # ifndef HAS_TM_TM_ZONE
3555 #    define HAS_TM_TM_ZONE
3556 # endif
3557 #endif
3558 
3559 void
3560 Perl_init_tm(pTHX_ struct tm *ptm)	/* see mktime, strftime and asctime */
3561 {
3562 #ifdef HAS_TM_TM_ZONE
3563     Time_t now;
3564     const struct tm* my_tm;
3565     PERL_UNUSED_CONTEXT;
3566     PERL_ARGS_ASSERT_INIT_TM;
3567     (void)time(&now);
3568     my_tm = localtime(&now);
3569     if (my_tm)
3570         Copy(my_tm, ptm, 1, struct tm);
3571 #else
3572     PERL_UNUSED_CONTEXT;
3573     PERL_ARGS_ASSERT_INIT_TM;
3574     PERL_UNUSED_ARG(ptm);
3575 #endif
3576 }
3577 
3578 /*
3579  * mini_mktime - normalise struct tm values without the localtime()
3580  * semantics (and overhead) of mktime().
3581  */
3582 void
3583 Perl_mini_mktime(struct tm *ptm)
3584 {
3585     int yearday;
3586     int secs;
3587     int month, mday, year, jday;
3588     int odd_cent, odd_year;
3589 
3590     PERL_ARGS_ASSERT_MINI_MKTIME;
3591 
3592 #define	DAYS_PER_YEAR	365
3593 #define	DAYS_PER_QYEAR	(4*DAYS_PER_YEAR+1)
3594 #define	DAYS_PER_CENT	(25*DAYS_PER_QYEAR-1)
3595 #define	DAYS_PER_QCENT	(4*DAYS_PER_CENT+1)
3596 #define	SECS_PER_HOUR	(60*60)
3597 #define	SECS_PER_DAY	(24*SECS_PER_HOUR)
3598 /* parentheses deliberately absent on these two, otherwise they don't work */
3599 #define	MONTH_TO_DAYS	153/5
3600 #define	DAYS_TO_MONTH	5/153
3601 /* offset to bias by March (month 4) 1st between month/mday & year finding */
3602 #define	YEAR_ADJUST	(4*MONTH_TO_DAYS+1)
3603 /* as used here, the algorithm leaves Sunday as day 1 unless we adjust it */
3604 #define	WEEKDAY_BIAS	6	/* (1+6)%7 makes Sunday 0 again */
3605 
3606 /*
3607  * Year/day algorithm notes:
3608  *
3609  * With a suitable offset for numeric value of the month, one can find
3610  * an offset into the year by considering months to have 30.6 (153/5) days,
3611  * using integer arithmetic (i.e., with truncation).  To avoid too much
3612  * messing about with leap days, we consider January and February to be
3613  * the 13th and 14th month of the previous year.  After that transformation,
3614  * we need the month index we use to be high by 1 from 'normal human' usage,
3615  * so the month index values we use run from 4 through 15.
3616  *
3617  * Given that, and the rules for the Gregorian calendar (leap years are those
3618  * divisible by 4 unless also divisible by 100, when they must be divisible
3619  * by 400 instead), we can simply calculate the number of days since some
3620  * arbitrary 'beginning of time' by futzing with the (adjusted) year number,
3621  * the days we derive from our month index, and adding in the day of the
3622  * month.  The value used here is not adjusted for the actual origin which
3623  * it normally would use (1 January A.D. 1), since we're not exposing it.
3624  * We're only building the value so we can turn around and get the
3625  * normalised values for the year, month, day-of-month, and day-of-year.
3626  *
3627  * For going backward, we need to bias the value we're using so that we find
3628  * the right year value.  (Basically, we don't want the contribution of
3629  * March 1st to the number to apply while deriving the year).  Having done
3630  * that, we 'count up' the contribution to the year number by accounting for
3631  * full quadracenturies (400-year periods) with their extra leap days, plus
3632  * the contribution from full centuries (to avoid counting in the lost leap
3633  * days), plus the contribution from full quad-years (to count in the normal
3634  * leap days), plus the leftover contribution from any non-leap years.
3635  * At this point, if we were working with an actual leap day, we'll have 0
3636  * days left over.  This is also true for March 1st, however.  So, we have
3637  * to special-case that result, and (earlier) keep track of the 'odd'
3638  * century and year contributions.  If we got 4 extra centuries in a qcent,
3639  * or 4 extra years in a qyear, then it's a leap day and we call it 29 Feb.
3640  * Otherwise, we add back in the earlier bias we removed (the 123 from
3641  * figuring in March 1st), find the month index (integer division by 30.6),
3642  * and the remainder is the day-of-month.  We then have to convert back to
3643  * 'real' months (including fixing January and February from being 14/15 in
3644  * the previous year to being in the proper year).  After that, to get
3645  * tm_yday, we work with the normalised year and get a new yearday value for
3646  * January 1st, which we subtract from the yearday value we had earlier,
3647  * representing the date we've re-built.  This is done from January 1
3648  * because tm_yday is 0-origin.
3649  *
3650  * Since POSIX time routines are only guaranteed to work for times since the
3651  * UNIX epoch (00:00:00 1 Jan 1970 UTC), the fact that this algorithm
3652  * applies Gregorian calendar rules even to dates before the 16th century
3653  * doesn't bother me.  Besides, you'd need cultural context for a given
3654  * date to know whether it was Julian or Gregorian calendar, and that's
3655  * outside the scope for this routine.  Since we convert back based on the
3656  * same rules we used to build the yearday, you'll only get strange results
3657  * for input which needed normalising, or for the 'odd' century years which
3658  * were leap years in the Julian calendar but not in the Gregorian one.
3659  * I can live with that.
3660  *
3661  * This algorithm also fails to handle years before A.D. 1 gracefully, but
3662  * that's still outside the scope for POSIX time manipulation, so I don't
3663  * care.
3664  *
3665  * - lwall
3666  */
3667 
3668     year = 1900 + ptm->tm_year;
3669     month = ptm->tm_mon;
3670     mday = ptm->tm_mday;
3671     jday = 0;
3672     if (month >= 2)
3673 	month+=2;
3674     else
3675 	month+=14, year--;
3676     yearday = DAYS_PER_YEAR * year + year/4 - year/100 + year/400;
3677     yearday += month*MONTH_TO_DAYS + mday + jday;
3678     /*
3679      * Note that we don't know when leap-seconds were or will be,
3680      * so we have to trust the user if we get something which looks
3681      * like a sensible leap-second.  Wild values for seconds will
3682      * be rationalised, however.
3683      */
3684     if ((unsigned) ptm->tm_sec <= 60) {
3685 	secs = 0;
3686     }
3687     else {
3688 	secs = ptm->tm_sec;
3689 	ptm->tm_sec = 0;
3690     }
3691     secs += 60 * ptm->tm_min;
3692     secs += SECS_PER_HOUR * ptm->tm_hour;
3693     if (secs < 0) {
3694 	if (secs-(secs/SECS_PER_DAY*SECS_PER_DAY) < 0) {
3695 	    /* got negative remainder, but need positive time */
3696 	    /* back off an extra day to compensate */
3697 	    yearday += (secs/SECS_PER_DAY)-1;
3698 	    secs -= SECS_PER_DAY * (secs/SECS_PER_DAY - 1);
3699 	}
3700 	else {
3701 	    yearday += (secs/SECS_PER_DAY);
3702 	    secs -= SECS_PER_DAY * (secs/SECS_PER_DAY);
3703 	}
3704     }
3705     else if (secs >= SECS_PER_DAY) {
3706 	yearday += (secs/SECS_PER_DAY);
3707 	secs %= SECS_PER_DAY;
3708     }
3709     ptm->tm_hour = secs/SECS_PER_HOUR;
3710     secs %= SECS_PER_HOUR;
3711     ptm->tm_min = secs/60;
3712     secs %= 60;
3713     ptm->tm_sec += secs;
3714     /* done with time of day effects */
3715     /*
3716      * The algorithm for yearday has (so far) left it high by 428.
3717      * To avoid mistaking a legitimate Feb 29 as Mar 1, we need to
3718      * bias it by 123 while trying to figure out what year it
3719      * really represents.  Even with this tweak, the reverse
3720      * translation fails for years before A.D. 0001.
3721      * It would still fail for Feb 29, but we catch that one below.
3722      */
3723     jday = yearday;	/* save for later fixup vis-a-vis Jan 1 */
3724     yearday -= YEAR_ADJUST;
3725     year = (yearday / DAYS_PER_QCENT) * 400;
3726     yearday %= DAYS_PER_QCENT;
3727     odd_cent = yearday / DAYS_PER_CENT;
3728     year += odd_cent * 100;
3729     yearday %= DAYS_PER_CENT;
3730     year += (yearday / DAYS_PER_QYEAR) * 4;
3731     yearday %= DAYS_PER_QYEAR;
3732     odd_year = yearday / DAYS_PER_YEAR;
3733     year += odd_year;
3734     yearday %= DAYS_PER_YEAR;
3735     if (!yearday && (odd_cent==4 || odd_year==4)) { /* catch Feb 29 */
3736 	month = 1;
3737 	yearday = 29;
3738     }
3739     else {
3740 	yearday += YEAR_ADJUST;	/* recover March 1st crock */
3741 	month = yearday*DAYS_TO_MONTH;
3742 	yearday -= month*MONTH_TO_DAYS;
3743 	/* recover other leap-year adjustment */
3744 	if (month > 13) {
3745 	    month-=14;
3746 	    year++;
3747 	}
3748 	else {
3749 	    month-=2;
3750 	}
3751     }
3752     ptm->tm_year = year - 1900;
3753     if (yearday) {
3754       ptm->tm_mday = yearday;
3755       ptm->tm_mon = month;
3756     }
3757     else {
3758       ptm->tm_mday = 31;
3759       ptm->tm_mon = month - 1;
3760     }
3761     /* re-build yearday based on Jan 1 to get tm_yday */
3762     year--;
3763     yearday = year*DAYS_PER_YEAR + year/4 - year/100 + year/400;
3764     yearday += 14*MONTH_TO_DAYS + 1;
3765     ptm->tm_yday = jday - yearday;
3766     ptm->tm_wday = (jday + WEEKDAY_BIAS) % 7;
3767 }
3768 
3769 char *
3770 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)
3771 {
3772 #ifdef HAS_STRFTIME
3773 
3774   /* strftime(), but with a different API so that the return value is a pointer
3775    * to the formatted result (which MUST be arranged to be FREED BY THE
3776    * CALLER).  This allows this function to increase the buffer size as needed,
3777    * so that the caller doesn't have to worry about that.
3778    *
3779    * Note that yday and wday effectively are ignored by this function, as
3780    * mini_mktime() overwrites them */
3781 
3782   char *buf;
3783   int buflen;
3784   struct tm mytm;
3785   int len;
3786 
3787   PERL_ARGS_ASSERT_MY_STRFTIME;
3788 
3789   init_tm(&mytm);	/* XXX workaround - see init_tm() above */
3790   mytm.tm_sec = sec;
3791   mytm.tm_min = min;
3792   mytm.tm_hour = hour;
3793   mytm.tm_mday = mday;
3794   mytm.tm_mon = mon;
3795   mytm.tm_year = year;
3796   mytm.tm_wday = wday;
3797   mytm.tm_yday = yday;
3798   mytm.tm_isdst = isdst;
3799   mini_mktime(&mytm);
3800   /* use libc to get the values for tm_gmtoff and tm_zone [perl #18238] */
3801 #if defined(HAS_MKTIME) && (defined(HAS_TM_TM_GMTOFF) || defined(HAS_TM_TM_ZONE))
3802   STMT_START {
3803     struct tm mytm2;
3804     mytm2 = mytm;
3805     mktime(&mytm2);
3806 #ifdef HAS_TM_TM_GMTOFF
3807     mytm.tm_gmtoff = mytm2.tm_gmtoff;
3808 #endif
3809 #ifdef HAS_TM_TM_ZONE
3810     mytm.tm_zone = mytm2.tm_zone;
3811 #endif
3812   } STMT_END;
3813 #endif
3814   buflen = 64;
3815   Newx(buf, buflen, char);
3816 
3817   GCC_DIAG_IGNORE_STMT(-Wformat-nonliteral); /* fmt checked by caller */
3818   len = strftime(buf, buflen, fmt, &mytm);
3819   GCC_DIAG_RESTORE_STMT;
3820 
3821   /*
3822   ** The following is needed to handle to the situation where
3823   ** tmpbuf overflows.  Basically we want to allocate a buffer
3824   ** and try repeatedly.  The reason why it is so complicated
3825   ** is that getting a return value of 0 from strftime can indicate
3826   ** one of the following:
3827   ** 1. buffer overflowed,
3828   ** 2. illegal conversion specifier, or
3829   ** 3. the format string specifies nothing to be returned(not
3830   **	  an error).  This could be because format is an empty string
3831   **    or it specifies %p that yields an empty string in some locale.
3832   ** If there is a better way to make it portable, go ahead by
3833   ** all means.
3834   */
3835   if ((len > 0 && len < buflen) || (len == 0 && *fmt == '\0'))
3836     return buf;
3837   else {
3838     /* Possibly buf overflowed - try again with a bigger buf */
3839     const int fmtlen = strlen(fmt);
3840     int bufsize = fmtlen + buflen;
3841 
3842     Renew(buf, bufsize, char);
3843     while (buf) {
3844 
3845       GCC_DIAG_IGNORE_STMT(-Wformat-nonliteral); /* fmt checked by caller */
3846       buflen = strftime(buf, bufsize, fmt, &mytm);
3847       GCC_DIAG_RESTORE_STMT;
3848 
3849       if (buflen > 0 && buflen < bufsize)
3850 	break;
3851       /* heuristic to prevent out-of-memory errors */
3852       if (bufsize > 100*fmtlen) {
3853 	Safefree(buf);
3854 	buf = NULL;
3855 	break;
3856       }
3857       bufsize *= 2;
3858       Renew(buf, bufsize, char);
3859     }
3860     return buf;
3861   }
3862 #else
3863   Perl_croak(aTHX_ "panic: no strftime");
3864   return NULL;
3865 #endif
3866 }
3867 
3868 
3869 #define SV_CWD_RETURN_UNDEF \
3870     sv_set_undef(sv); \
3871     return FALSE
3872 
3873 #define SV_CWD_ISDOT(dp) \
3874     (dp->d_name[0] == '.' && (dp->d_name[1] == '\0' || \
3875 	(dp->d_name[1] == '.' && dp->d_name[2] == '\0')))
3876 
3877 /*
3878 =head1 Miscellaneous Functions
3879 
3880 =for apidoc getcwd_sv
3881 
3882 Fill C<sv> with current working directory
3883 
3884 =cut
3885 */
3886 
3887 /* Originally written in Perl by John Bazik; rewritten in C by Ben Sugars.
3888  * rewritten again by dougm, optimized for use with xs TARG, and to prefer
3889  * getcwd(3) if available
3890  * Comments from the original:
3891  *     This is a faster version of getcwd.  It's also more dangerous
3892  *     because you might chdir out of a directory that you can't chdir
3893  *     back into. */
3894 
3895 int
3896 Perl_getcwd_sv(pTHX_ SV *sv)
3897 {
3898 #ifndef PERL_MICRO
3899     SvTAINTED_on(sv);
3900 
3901     PERL_ARGS_ASSERT_GETCWD_SV;
3902 
3903 #ifdef HAS_GETCWD
3904     {
3905 	char buf[MAXPATHLEN];
3906 
3907 	/* Some getcwd()s automatically allocate a buffer of the given
3908 	 * size from the heap if they are given a NULL buffer pointer.
3909 	 * The problem is that this behaviour is not portable. */
3910 	if (getcwd(buf, sizeof(buf) - 1)) {
3911 	    sv_setpv(sv, buf);
3912 	    return TRUE;
3913 	}
3914 	else {
3915 	    SV_CWD_RETURN_UNDEF;
3916 	}
3917     }
3918 
3919 #else
3920 
3921     Stat_t statbuf;
3922     int orig_cdev, orig_cino, cdev, cino, odev, oino, tdev, tino;
3923     int pathlen=0;
3924     Direntry_t *dp;
3925 
3926     SvUPGRADE(sv, SVt_PV);
3927 
3928     if (PerlLIO_lstat(".", &statbuf) < 0) {
3929 	SV_CWD_RETURN_UNDEF;
3930     }
3931 
3932     orig_cdev = statbuf.st_dev;
3933     orig_cino = statbuf.st_ino;
3934     cdev = orig_cdev;
3935     cino = orig_cino;
3936 
3937     for (;;) {
3938 	DIR *dir;
3939 	int namelen;
3940 	odev = cdev;
3941 	oino = cino;
3942 
3943 	if (PerlDir_chdir("..") < 0) {
3944 	    SV_CWD_RETURN_UNDEF;
3945 	}
3946 	if (PerlLIO_stat(".", &statbuf) < 0) {
3947 	    SV_CWD_RETURN_UNDEF;
3948 	}
3949 
3950 	cdev = statbuf.st_dev;
3951 	cino = statbuf.st_ino;
3952 
3953 	if (odev == cdev && oino == cino) {
3954 	    break;
3955 	}
3956 	if (!(dir = PerlDir_open("."))) {
3957 	    SV_CWD_RETURN_UNDEF;
3958 	}
3959 
3960 	while ((dp = PerlDir_read(dir)) != NULL) {
3961 #ifdef DIRNAMLEN
3962 	    namelen = dp->d_namlen;
3963 #else
3964 	    namelen = strlen(dp->d_name);
3965 #endif
3966 	    /* skip . and .. */
3967 	    if (SV_CWD_ISDOT(dp)) {
3968 		continue;
3969 	    }
3970 
3971 	    if (PerlLIO_lstat(dp->d_name, &statbuf) < 0) {
3972 		SV_CWD_RETURN_UNDEF;
3973 	    }
3974 
3975 	    tdev = statbuf.st_dev;
3976 	    tino = statbuf.st_ino;
3977 	    if (tino == oino && tdev == odev) {
3978 		break;
3979 	    }
3980 	}
3981 
3982 	if (!dp) {
3983 	    SV_CWD_RETURN_UNDEF;
3984 	}
3985 
3986 	if (pathlen + namelen + 1 >= MAXPATHLEN) {
3987 	    SV_CWD_RETURN_UNDEF;
3988 	}
3989 
3990 	SvGROW(sv, pathlen + namelen + 1);
3991 
3992 	if (pathlen) {
3993 	    /* shift down */
3994 	    Move(SvPVX_const(sv), SvPVX(sv) + namelen + 1, pathlen, char);
3995 	}
3996 
3997 	/* prepend current directory to the front */
3998 	*SvPVX(sv) = '/';
3999 	Move(dp->d_name, SvPVX(sv)+1, namelen, char);
4000 	pathlen += (namelen + 1);
4001 
4002 #ifdef VOID_CLOSEDIR
4003 	PerlDir_close(dir);
4004 #else
4005 	if (PerlDir_close(dir) < 0) {
4006 	    SV_CWD_RETURN_UNDEF;
4007 	}
4008 #endif
4009     }
4010 
4011     if (pathlen) {
4012 	SvCUR_set(sv, pathlen);
4013 	*SvEND(sv) = '\0';
4014 	SvPOK_only(sv);
4015 
4016 	if (PerlDir_chdir(SvPVX_const(sv)) < 0) {
4017 	    SV_CWD_RETURN_UNDEF;
4018 	}
4019     }
4020     if (PerlLIO_stat(".", &statbuf) < 0) {
4021 	SV_CWD_RETURN_UNDEF;
4022     }
4023 
4024     cdev = statbuf.st_dev;
4025     cino = statbuf.st_ino;
4026 
4027     if (cdev != orig_cdev || cino != orig_cino) {
4028 	Perl_croak(aTHX_ "Unstable directory path, "
4029 		   "current directory changed unexpectedly");
4030     }
4031 
4032     return TRUE;
4033 #endif
4034 
4035 #else
4036     return FALSE;
4037 #endif
4038 }
4039 
4040 #include "vutil.c"
4041 
4042 #if !defined(HAS_SOCKETPAIR) && defined(HAS_SOCKET) && defined(AF_INET) && defined(PF_INET) && defined(SOCK_DGRAM) && defined(HAS_SELECT)
4043 #   define EMULATE_SOCKETPAIR_UDP
4044 #endif
4045 
4046 #ifdef EMULATE_SOCKETPAIR_UDP
4047 static int
4048 S_socketpair_udp (int fd[2]) {
4049     dTHX;
4050     /* Fake a datagram socketpair using UDP to localhost.  */
4051     int sockets[2] = {-1, -1};
4052     struct sockaddr_in addresses[2];
4053     int i;
4054     Sock_size_t size = sizeof(struct sockaddr_in);
4055     unsigned short port;
4056     int got;
4057 
4058     memset(&addresses, 0, sizeof(addresses));
4059     i = 1;
4060     do {
4061 	sockets[i] = PerlSock_socket(AF_INET, SOCK_DGRAM, PF_INET);
4062 	if (sockets[i] == -1)
4063 	    goto tidy_up_and_fail;
4064 
4065 	addresses[i].sin_family = AF_INET;
4066 	addresses[i].sin_addr.s_addr = htonl(INADDR_LOOPBACK);
4067 	addresses[i].sin_port = 0;	/* kernel choses port.  */
4068 	if (PerlSock_bind(sockets[i], (struct sockaddr *) &addresses[i],
4069 		sizeof(struct sockaddr_in)) == -1)
4070 	    goto tidy_up_and_fail;
4071     } while (i--);
4072 
4073     /* Now have 2 UDP sockets. Find out which port each is connected to, and
4074        for each connect the other socket to it.  */
4075     i = 1;
4076     do {
4077 	if (PerlSock_getsockname(sockets[i], (struct sockaddr *) &addresses[i],
4078 		&size) == -1)
4079 	    goto tidy_up_and_fail;
4080 	if (size != sizeof(struct sockaddr_in))
4081 	    goto abort_tidy_up_and_fail;
4082 	/* !1 is 0, !0 is 1 */
4083 	if (PerlSock_connect(sockets[!i], (struct sockaddr *) &addresses[i],
4084 		sizeof(struct sockaddr_in)) == -1)
4085 	    goto tidy_up_and_fail;
4086     } while (i--);
4087 
4088     /* Now we have 2 sockets connected to each other. I don't trust some other
4089        process not to have already sent a packet to us (by random) so send
4090        a packet from each to the other.  */
4091     i = 1;
4092     do {
4093 	/* I'm going to send my own port number.  As a short.
4094 	   (Who knows if someone somewhere has sin_port as a bitfield and needs
4095 	   this routine. (I'm assuming crays have socketpair)) */
4096 	port = addresses[i].sin_port;
4097 	got = PerlLIO_write(sockets[i], &port, sizeof(port));
4098 	if (got != sizeof(port)) {
4099 	    if (got == -1)
4100 		goto tidy_up_and_fail;
4101 	    goto abort_tidy_up_and_fail;
4102 	}
4103     } while (i--);
4104 
4105     /* Packets sent. I don't trust them to have arrived though.
4106        (As I understand it Solaris TCP stack is multithreaded. Non-blocking
4107        connect to localhost will use a second kernel thread. In 2.6 the
4108        first thread running the connect() returns before the second completes,
4109        so EINPROGRESS> In 2.7 the improved stack is faster and connect()
4110        returns 0. Poor programs have tripped up. One poor program's authors'
4111        had a 50-1 reverse stock split. Not sure how connected these were.)
4112        So I don't trust someone not to have an unpredictable UDP stack.
4113     */
4114 
4115     {
4116 	struct timeval waitfor = {0, 100000}; /* You have 0.1 seconds */
4117 	int max = sockets[1] > sockets[0] ? sockets[1] : sockets[0];
4118 	fd_set rset;
4119 
4120 	FD_ZERO(&rset);
4121 	FD_SET((unsigned int)sockets[0], &rset);
4122 	FD_SET((unsigned int)sockets[1], &rset);
4123 
4124 	got = PerlSock_select(max + 1, &rset, NULL, NULL, &waitfor);
4125 	if (got != 2 || !FD_ISSET(sockets[0], &rset)
4126 		|| !FD_ISSET(sockets[1], &rset)) {
4127 	    /* I hope this is portable and appropriate.  */
4128 	    if (got == -1)
4129 		goto tidy_up_and_fail;
4130 	    goto abort_tidy_up_and_fail;
4131 	}
4132     }
4133 
4134     /* And the paranoia department even now doesn't trust it to have arrive
4135        (hence MSG_DONTWAIT). Or that what arrives was sent by us.  */
4136     {
4137 	struct sockaddr_in readfrom;
4138 	unsigned short buffer[2];
4139 
4140 	i = 1;
4141 	do {
4142 #ifdef MSG_DONTWAIT
4143 	    got = PerlSock_recvfrom(sockets[i], (char *) &buffer,
4144 		    sizeof(buffer), MSG_DONTWAIT,
4145 		    (struct sockaddr *) &readfrom, &size);
4146 #else
4147 	    got = PerlSock_recvfrom(sockets[i], (char *) &buffer,
4148 		    sizeof(buffer), 0,
4149 		    (struct sockaddr *) &readfrom, &size);
4150 #endif
4151 
4152 	    if (got == -1)
4153 		goto tidy_up_and_fail;
4154 	    if (got != sizeof(port)
4155 		    || size != sizeof(struct sockaddr_in)
4156 		    /* Check other socket sent us its port.  */
4157 		    || buffer[0] != (unsigned short) addresses[!i].sin_port
4158 		    /* Check kernel says we got the datagram from that socket */
4159 		    || readfrom.sin_family != addresses[!i].sin_family
4160 		    || readfrom.sin_addr.s_addr != addresses[!i].sin_addr.s_addr
4161 		    || readfrom.sin_port != addresses[!i].sin_port)
4162 		goto abort_tidy_up_and_fail;
4163 	} while (i--);
4164     }
4165     /* My caller (my_socketpair) has validated that this is non-NULL  */
4166     fd[0] = sockets[0];
4167     fd[1] = sockets[1];
4168     /* I hereby declare this connection open.  May God bless all who cross
4169        her.  */
4170     return 0;
4171 
4172   abort_tidy_up_and_fail:
4173     errno = ECONNABORTED;
4174   tidy_up_and_fail:
4175     {
4176 	dSAVE_ERRNO;
4177 	if (sockets[0] != -1)
4178 	    PerlLIO_close(sockets[0]);
4179 	if (sockets[1] != -1)
4180 	    PerlLIO_close(sockets[1]);
4181 	RESTORE_ERRNO;
4182 	return -1;
4183     }
4184 }
4185 #endif /*  EMULATE_SOCKETPAIR_UDP */
4186 
4187 #if !defined(HAS_SOCKETPAIR) && defined(HAS_SOCKET) && defined(AF_INET) && defined(PF_INET)
4188 int
4189 Perl_my_socketpair (int family, int type, int protocol, int fd[2]) {
4190     /* Stevens says that family must be AF_LOCAL, protocol 0.
4191        I'm going to enforce that, then ignore it, and use TCP (or UDP).  */
4192     dTHXa(NULL);
4193     int listener = -1;
4194     int connector = -1;
4195     int acceptor = -1;
4196     struct sockaddr_in listen_addr;
4197     struct sockaddr_in connect_addr;
4198     Sock_size_t size;
4199 
4200     if (protocol
4201 #ifdef AF_UNIX
4202 	|| family != AF_UNIX
4203 #endif
4204     ) {
4205 	errno = EAFNOSUPPORT;
4206 	return -1;
4207     }
4208     if (!fd) {
4209 	errno = EINVAL;
4210 	return -1;
4211     }
4212 
4213 #ifdef SOCK_CLOEXEC
4214     type &= ~SOCK_CLOEXEC;
4215 #endif
4216 
4217 #ifdef EMULATE_SOCKETPAIR_UDP
4218     if (type == SOCK_DGRAM)
4219 	return S_socketpair_udp(fd);
4220 #endif
4221 
4222     aTHXa(PERL_GET_THX);
4223     listener = PerlSock_socket(AF_INET, type, 0);
4224     if (listener == -1)
4225 	return -1;
4226     memset(&listen_addr, 0, sizeof(listen_addr));
4227     listen_addr.sin_family = AF_INET;
4228     listen_addr.sin_addr.s_addr = htonl(INADDR_LOOPBACK);
4229     listen_addr.sin_port = 0;	/* kernel choses port.  */
4230     if (PerlSock_bind(listener, (struct sockaddr *) &listen_addr,
4231 	    sizeof(listen_addr)) == -1)
4232 	goto tidy_up_and_fail;
4233     if (PerlSock_listen(listener, 1) == -1)
4234 	goto tidy_up_and_fail;
4235 
4236     connector = PerlSock_socket(AF_INET, type, 0);
4237     if (connector == -1)
4238 	goto tidy_up_and_fail;
4239     /* We want to find out the port number to connect to.  */
4240     size = sizeof(connect_addr);
4241     if (PerlSock_getsockname(listener, (struct sockaddr *) &connect_addr,
4242 	    &size) == -1)
4243 	goto tidy_up_and_fail;
4244     if (size != sizeof(connect_addr))
4245 	goto abort_tidy_up_and_fail;
4246     if (PerlSock_connect(connector, (struct sockaddr *) &connect_addr,
4247 	    sizeof(connect_addr)) == -1)
4248 	goto tidy_up_and_fail;
4249 
4250     size = sizeof(listen_addr);
4251     acceptor = PerlSock_accept(listener, (struct sockaddr *) &listen_addr,
4252 	    &size);
4253     if (acceptor == -1)
4254 	goto tidy_up_and_fail;
4255     if (size != sizeof(listen_addr))
4256 	goto abort_tidy_up_and_fail;
4257     PerlLIO_close(listener);
4258     /* Now check we are talking to ourself by matching port and host on the
4259        two sockets.  */
4260     if (PerlSock_getsockname(connector, (struct sockaddr *) &connect_addr,
4261 	    &size) == -1)
4262 	goto tidy_up_and_fail;
4263     if (size != sizeof(connect_addr)
4264 	    || listen_addr.sin_family != connect_addr.sin_family
4265 	    || listen_addr.sin_addr.s_addr != connect_addr.sin_addr.s_addr
4266 	    || listen_addr.sin_port != connect_addr.sin_port) {
4267 	goto abort_tidy_up_and_fail;
4268     }
4269     fd[0] = connector;
4270     fd[1] = acceptor;
4271     return 0;
4272 
4273   abort_tidy_up_and_fail:
4274 #ifdef ECONNABORTED
4275   errno = ECONNABORTED;	/* This would be the standard thing to do. */
4276 #elif defined(ECONNREFUSED)
4277   errno = ECONNREFUSED;	/* E.g. Symbian does not have ECONNABORTED. */
4278 #else
4279   errno = ETIMEDOUT;	/* Desperation time. */
4280 #endif
4281   tidy_up_and_fail:
4282     {
4283 	dSAVE_ERRNO;
4284 	if (listener != -1)
4285 	    PerlLIO_close(listener);
4286 	if (connector != -1)
4287 	    PerlLIO_close(connector);
4288 	if (acceptor != -1)
4289 	    PerlLIO_close(acceptor);
4290 	RESTORE_ERRNO;
4291 	return -1;
4292     }
4293 }
4294 #else
4295 /* In any case have a stub so that there's code corresponding
4296  * to the my_socketpair in embed.fnc. */
4297 int
4298 Perl_my_socketpair (int family, int type, int protocol, int fd[2]) {
4299 #ifdef HAS_SOCKETPAIR
4300     return socketpair(family, type, protocol, fd);
4301 #else
4302     return -1;
4303 #endif
4304 }
4305 #endif
4306 
4307 /*
4308 
4309 =for apidoc sv_nosharing
4310 
4311 Dummy routine which "shares" an SV when there is no sharing module present.
4312 Or "locks" it.  Or "unlocks" it.  In other
4313 words, ignores its single SV argument.
4314 Exists to avoid test for a C<NULL> function pointer and because it could
4315 potentially warn under some level of strict-ness.
4316 
4317 =cut
4318 */
4319 
4320 void
4321 Perl_sv_nosharing(pTHX_ SV *sv)
4322 {
4323     PERL_UNUSED_CONTEXT;
4324     PERL_UNUSED_ARG(sv);
4325 }
4326 
4327 /*
4328 
4329 =for apidoc sv_destroyable
4330 
4331 Dummy routine which reports that object can be destroyed when there is no
4332 sharing module present.  It ignores its single SV argument, and returns
4333 'true'.  Exists to avoid test for a C<NULL> function pointer and because it
4334 could potentially warn under some level of strict-ness.
4335 
4336 =cut
4337 */
4338 
4339 bool
4340 Perl_sv_destroyable(pTHX_ SV *sv)
4341 {
4342     PERL_UNUSED_CONTEXT;
4343     PERL_UNUSED_ARG(sv);
4344     return TRUE;
4345 }
4346 
4347 U32
4348 Perl_parse_unicode_opts(pTHX_ const char **popt)
4349 {
4350   const char *p = *popt;
4351   U32 opt = 0;
4352 
4353   PERL_ARGS_ASSERT_PARSE_UNICODE_OPTS;
4354 
4355   if (*p) {
4356        if (isDIGIT(*p)) {
4357             const char* endptr;
4358             UV uv;
4359             if (grok_atoUV(p, &uv, &endptr) && uv <= U32_MAX) {
4360                 opt = (U32)uv;
4361                 p = endptr;
4362                 if (p && *p && *p != '\n' && *p != '\r') {
4363                     if (isSPACE(*p))
4364                         goto the_end_of_the_opts_parser;
4365                     else
4366                         Perl_croak(aTHX_ "Unknown Unicode option letter '%c'", *p);
4367                 }
4368             }
4369             else {
4370                 Perl_croak(aTHX_ "Invalid number '%s' for -C option.\n", p);
4371             }
4372         }
4373         else {
4374 	    for (; *p; p++) {
4375 		 switch (*p) {
4376 		 case PERL_UNICODE_STDIN:
4377 		      opt |= PERL_UNICODE_STDIN_FLAG;	break;
4378 		 case PERL_UNICODE_STDOUT:
4379 		      opt |= PERL_UNICODE_STDOUT_FLAG;	break;
4380 		 case PERL_UNICODE_STDERR:
4381 		      opt |= PERL_UNICODE_STDERR_FLAG;	break;
4382 		 case PERL_UNICODE_STD:
4383 		      opt |= PERL_UNICODE_STD_FLAG;    	break;
4384 		 case PERL_UNICODE_IN:
4385 		      opt |= PERL_UNICODE_IN_FLAG;	break;
4386 		 case PERL_UNICODE_OUT:
4387 		      opt |= PERL_UNICODE_OUT_FLAG;	break;
4388 		 case PERL_UNICODE_INOUT:
4389 		      opt |= PERL_UNICODE_INOUT_FLAG;	break;
4390 		 case PERL_UNICODE_LOCALE:
4391 		      opt |= PERL_UNICODE_LOCALE_FLAG;	break;
4392 		 case PERL_UNICODE_ARGV:
4393 		      opt |= PERL_UNICODE_ARGV_FLAG;	break;
4394 		 case PERL_UNICODE_UTF8CACHEASSERT:
4395 		      opt |= PERL_UNICODE_UTF8CACHEASSERT_FLAG; break;
4396 		 default:
4397 		      if (*p != '\n' && *p != '\r') {
4398 			if(isSPACE(*p)) goto the_end_of_the_opts_parser;
4399 			else
4400 			  Perl_croak(aTHX_
4401 				     "Unknown Unicode option letter '%c'", *p);
4402 		      }
4403 		 }
4404 	    }
4405        }
4406   }
4407   else
4408        opt = PERL_UNICODE_DEFAULT_FLAGS;
4409 
4410   the_end_of_the_opts_parser:
4411 
4412   if (opt & ~PERL_UNICODE_ALL_FLAGS)
4413        Perl_croak(aTHX_ "Unknown Unicode option value %" UVuf,
4414 		  (UV) (opt & ~PERL_UNICODE_ALL_FLAGS));
4415 
4416   *popt = p;
4417 
4418   return opt;
4419 }
4420 
4421 #ifdef VMS
4422 #  include <starlet.h>
4423 #endif
4424 
4425 U32
4426 Perl_seed(pTHX)
4427 {
4428 #if defined(__OpenBSD__)
4429 	return arc4random();
4430 #else
4431     /*
4432      * This is really just a quick hack which grabs various garbage
4433      * values.  It really should be a real hash algorithm which
4434      * spreads the effect of every input bit onto every output bit,
4435      * if someone who knows about such things would bother to write it.
4436      * Might be a good idea to add that function to CORE as well.
4437      * No numbers below come from careful analysis or anything here,
4438      * except they are primes and SEED_C1 > 1E6 to get a full-width
4439      * value from (tv_sec * SEED_C1 + tv_usec).  The multipliers should
4440      * probably be bigger too.
4441      */
4442 #if RANDBITS > 16
4443 #  define SEED_C1	1000003
4444 #define   SEED_C4	73819
4445 #else
4446 #  define SEED_C1	25747
4447 #define   SEED_C4	20639
4448 #endif
4449 #define   SEED_C2	3
4450 #define   SEED_C3	269
4451 #define   SEED_C5	26107
4452 
4453 #ifndef PERL_NO_DEV_RANDOM
4454     int fd;
4455 #endif
4456     U32 u;
4457 #ifdef HAS_GETTIMEOFDAY
4458     struct timeval when;
4459 #else
4460     Time_t when;
4461 #endif
4462 
4463 /* This test is an escape hatch, this symbol isn't set by Configure. */
4464 #ifndef PERL_NO_DEV_RANDOM
4465 #ifndef PERL_RANDOM_DEVICE
4466    /* /dev/random isn't used by default because reads from it will block
4467     * if there isn't enough entropy available.  You can compile with
4468     * PERL_RANDOM_DEVICE to it if you'd prefer Perl to block until there
4469     * is enough real entropy to fill the seed. */
4470 #  ifdef __amigaos4__
4471 #    define PERL_RANDOM_DEVICE "RANDOM:SIZE=4"
4472 #  else
4473 #    define PERL_RANDOM_DEVICE "/dev/urandom"
4474 #  endif
4475 #endif
4476     fd = PerlLIO_open_cloexec(PERL_RANDOM_DEVICE, 0);
4477     if (fd != -1) {
4478     	if (PerlLIO_read(fd, (void*)&u, sizeof u) != sizeof u)
4479 	    u = 0;
4480 	PerlLIO_close(fd);
4481 	if (u)
4482 	    return u;
4483     }
4484 #endif
4485 
4486 #ifdef HAS_GETTIMEOFDAY
4487     PerlProc_gettimeofday(&when,NULL);
4488     u = (U32)SEED_C1 * when.tv_sec + (U32)SEED_C2 * when.tv_usec;
4489 #else
4490     (void)time(&when);
4491     u = (U32)SEED_C1 * when;
4492 #endif
4493     u += SEED_C3 * (U32)PerlProc_getpid();
4494     u += SEED_C4 * (U32)PTR2UV(PL_stack_sp);
4495 #ifndef PLAN9           /* XXX Plan9 assembler chokes on this; fix needed  */
4496     u += SEED_C5 * (U32)PTR2UV(&when);
4497 #endif
4498     return u;
4499 #endif
4500 }
4501 
4502 void
4503 Perl_get_hash_seed(pTHX_ unsigned char * const seed_buffer)
4504 {
4505 #ifndef NO_PERL_HASH_ENV
4506     const char *env_pv;
4507 #endif
4508     unsigned long i;
4509 
4510     PERL_ARGS_ASSERT_GET_HASH_SEED;
4511 
4512 #ifndef NO_PERL_HASH_ENV
4513     env_pv= PerlEnv_getenv("PERL_HASH_SEED");
4514 
4515     if ( env_pv )
4516     {
4517         /* ignore leading spaces */
4518         while (isSPACE(*env_pv))
4519             env_pv++;
4520 #    ifdef USE_PERL_PERTURB_KEYS
4521         /* if they set it to "0" we disable key traversal randomization completely */
4522         if (strEQ(env_pv,"0")) {
4523             PL_hash_rand_bits_enabled= 0;
4524         } else {
4525             /* otherwise switch to deterministic mode */
4526             PL_hash_rand_bits_enabled= 2;
4527         }
4528 #    endif
4529         /* ignore a leading 0x... if it is there */
4530         if (env_pv[0] == '0' && env_pv[1] == 'x')
4531             env_pv += 2;
4532 
4533         for( i = 0; isXDIGIT(*env_pv) && i < PERL_HASH_SEED_BYTES; i++ ) {
4534             seed_buffer[i] = READ_XDIGIT(env_pv) << 4;
4535             if ( isXDIGIT(*env_pv)) {
4536                 seed_buffer[i] |= READ_XDIGIT(env_pv);
4537             }
4538         }
4539         while (isSPACE(*env_pv))
4540             env_pv++;
4541 
4542         if (*env_pv && !isXDIGIT(*env_pv)) {
4543             Perl_warn(aTHX_ "perl: warning: Non hex character in '$ENV{PERL_HASH_SEED}', seed only partially set\n");
4544         }
4545         /* should we check for unparsed crap? */
4546         /* should we warn about unused hex? */
4547         /* should we warn about insufficient hex? */
4548     }
4549     else
4550 #endif /* NO_PERL_HASH_ENV */
4551     {
4552         for( i = 0; i < PERL_HASH_SEED_BYTES; i++ ) {
4553             seed_buffer[i] = (unsigned char)(Perl_internal_drand48() * (U8_MAX+1));
4554         }
4555     }
4556 #ifdef USE_PERL_PERTURB_KEYS
4557     {   /* initialize PL_hash_rand_bits from the hash seed.
4558          * This value is highly volatile, it is updated every
4559          * hash insert, and is used as part of hash bucket chain
4560          * randomization and hash iterator randomization. */
4561         PL_hash_rand_bits= 0xbe49d17f; /* I just picked a number */
4562         for( i = 0; i < sizeof(UV) ; i++ ) {
4563             PL_hash_rand_bits += seed_buffer[i % PERL_HASH_SEED_BYTES];
4564             PL_hash_rand_bits = ROTL_UV(PL_hash_rand_bits,8);
4565         }
4566     }
4567 #  ifndef NO_PERL_HASH_ENV
4568     env_pv= PerlEnv_getenv("PERL_PERTURB_KEYS");
4569     if (env_pv) {
4570         if (strEQ(env_pv,"0") || strEQ(env_pv,"NO")) {
4571             PL_hash_rand_bits_enabled= 0;
4572         } else if (strEQ(env_pv,"1") || strEQ(env_pv,"RANDOM")) {
4573             PL_hash_rand_bits_enabled= 1;
4574         } else if (strEQ(env_pv,"2") || strEQ(env_pv,"DETERMINISTIC")) {
4575             PL_hash_rand_bits_enabled= 2;
4576         } else {
4577             Perl_warn(aTHX_ "perl: warning: strange setting in '$ENV{PERL_PERTURB_KEYS}': '%s'\n", env_pv);
4578         }
4579     }
4580 #  endif
4581 #endif
4582 }
4583 
4584 #ifdef PERL_GLOBAL_STRUCT
4585 
4586 #define PERL_GLOBAL_STRUCT_INIT
4587 #include "opcode.h" /* the ppaddr and check */
4588 
4589 struct perl_vars *
4590 Perl_init_global_struct(pTHX)
4591 {
4592     struct perl_vars *plvarsp = NULL;
4593 # ifdef PERL_GLOBAL_STRUCT
4594     const IV nppaddr = C_ARRAY_LENGTH(Gppaddr);
4595     const IV ncheck  = C_ARRAY_LENGTH(Gcheck);
4596     PERL_UNUSED_CONTEXT;
4597 #  ifdef PERL_GLOBAL_STRUCT_PRIVATE
4598     /* PerlMem_malloc() because can't use even safesysmalloc() this early. */
4599     plvarsp = (struct perl_vars*)PerlMem_malloc(sizeof(struct perl_vars));
4600     if (!plvarsp)
4601         exit(1);
4602 #  else
4603     plvarsp = PL_VarsPtr;
4604 #  endif /* PERL_GLOBAL_STRUCT_PRIVATE */
4605 #  undef PERLVAR
4606 #  undef PERLVARA
4607 #  undef PERLVARI
4608 #  undef PERLVARIC
4609 #  define PERLVAR(prefix,var,type) /**/
4610 #  define PERLVARA(prefix,var,n,type) /**/
4611 #  define PERLVARI(prefix,var,type,init) plvarsp->prefix##var = init;
4612 #  define PERLVARIC(prefix,var,type,init) plvarsp->prefix##var = init;
4613 #  include "perlvars.h"
4614 #  undef PERLVAR
4615 #  undef PERLVARA
4616 #  undef PERLVARI
4617 #  undef PERLVARIC
4618 #  ifdef PERL_GLOBAL_STRUCT
4619     plvarsp->Gppaddr =
4620 	(Perl_ppaddr_t*)
4621 	PerlMem_malloc(nppaddr * sizeof(Perl_ppaddr_t));
4622     if (!plvarsp->Gppaddr)
4623         exit(1);
4624     plvarsp->Gcheck  =
4625 	(Perl_check_t*)
4626 	PerlMem_malloc(ncheck  * sizeof(Perl_check_t));
4627     if (!plvarsp->Gcheck)
4628         exit(1);
4629     Copy(Gppaddr, plvarsp->Gppaddr, nppaddr, Perl_ppaddr_t);
4630     Copy(Gcheck,  plvarsp->Gcheck,  ncheck,  Perl_check_t);
4631 #  endif
4632 #  ifdef PERL_SET_VARS
4633     PERL_SET_VARS(plvarsp);
4634 #  endif
4635 #  ifdef PERL_GLOBAL_STRUCT_PRIVATE
4636     plvarsp->Gsv_placeholder.sv_flags = 0;
4637     memset(plvarsp->Ghash_seed, 0, sizeof(plvarsp->Ghash_seed));
4638 #  endif
4639 # undef PERL_GLOBAL_STRUCT_INIT
4640 # endif
4641     return plvarsp;
4642 }
4643 
4644 #endif /* PERL_GLOBAL_STRUCT */
4645 
4646 #ifdef PERL_GLOBAL_STRUCT
4647 
4648 void
4649 Perl_free_global_struct(pTHX_ struct perl_vars *plvarsp)
4650 {
4651     int veto = plvarsp->Gveto_cleanup;
4652 
4653     PERL_ARGS_ASSERT_FREE_GLOBAL_STRUCT;
4654     PERL_UNUSED_CONTEXT;
4655 # ifdef PERL_GLOBAL_STRUCT
4656 #  ifdef PERL_UNSET_VARS
4657     PERL_UNSET_VARS(plvarsp);
4658 #  endif
4659     if (veto)
4660         return;
4661     free(plvarsp->Gppaddr);
4662     free(plvarsp->Gcheck);
4663 #  ifdef PERL_GLOBAL_STRUCT_PRIVATE
4664     free(plvarsp);
4665 #  endif
4666 # endif
4667 }
4668 
4669 #endif /* PERL_GLOBAL_STRUCT */
4670 
4671 #ifdef PERL_MEM_LOG
4672 
4673 /* -DPERL_MEM_LOG: the Perl_mem_log_..() is compiled, including
4674  * the default implementation, unless -DPERL_MEM_LOG_NOIMPL is also
4675  * given, and you supply your own implementation.
4676  *
4677  * The default implementation reads a single env var, PERL_MEM_LOG,
4678  * expecting one or more of the following:
4679  *
4680  *    \d+ - fd		fd to write to		: must be 1st (grok_atoUV)
4681  *    'm' - memlog	was PERL_MEM_LOG=1
4682  *    's' - svlog	was PERL_SV_LOG=1
4683  *    't' - timestamp	was PERL_MEM_LOG_TIMESTAMP=1
4684  *
4685  * This makes the logger controllable enough that it can reasonably be
4686  * added to the system perl.
4687  */
4688 
4689 /* -DPERL_MEM_LOG_SPRINTF_BUF_SIZE=X: size of a (stack-allocated) buffer
4690  * the Perl_mem_log_...() will use (either via sprintf or snprintf).
4691  */
4692 #define PERL_MEM_LOG_SPRINTF_BUF_SIZE 128
4693 
4694 /* -DPERL_MEM_LOG_FD=N: the file descriptor the Perl_mem_log_...()
4695  * writes to.  In the default logger, this is settable at runtime.
4696  */
4697 #ifndef PERL_MEM_LOG_FD
4698 #  define PERL_MEM_LOG_FD 2 /* If STDERR is too boring for you. */
4699 #endif
4700 
4701 #ifndef PERL_MEM_LOG_NOIMPL
4702 
4703 # ifdef DEBUG_LEAKING_SCALARS
4704 #   define SV_LOG_SERIAL_FMT	    " [%lu]"
4705 #   define _SV_LOG_SERIAL_ARG(sv)   , (unsigned long) (sv)->sv_debug_serial
4706 # else
4707 #   define SV_LOG_SERIAL_FMT
4708 #   define _SV_LOG_SERIAL_ARG(sv)
4709 # endif
4710 
4711 static void
4712 S_mem_log_common(enum mem_log_type mlt, const UV n,
4713 		 const UV typesize, const char *type_name, const SV *sv,
4714 		 Malloc_t oldalloc, Malloc_t newalloc,
4715 		 const char *filename, const int linenumber,
4716 		 const char *funcname)
4717 {
4718     const char *pmlenv;
4719 
4720     PERL_ARGS_ASSERT_MEM_LOG_COMMON;
4721 
4722     pmlenv = PerlEnv_getenv("PERL_MEM_LOG");
4723     if (!pmlenv)
4724 	return;
4725     if (mlt < MLT_NEW_SV ? strchr(pmlenv,'m') : strchr(pmlenv,'s'))
4726     {
4727 	/* We can't use SVs or PerlIO for obvious reasons,
4728 	 * so we'll use stdio and low-level IO instead. */
4729 	char buf[PERL_MEM_LOG_SPRINTF_BUF_SIZE];
4730 
4731 #   ifdef HAS_GETTIMEOFDAY
4732 #     define MEM_LOG_TIME_FMT	"%10d.%06d: "
4733 #     define MEM_LOG_TIME_ARG	(int)tv.tv_sec, (int)tv.tv_usec
4734 	struct timeval tv;
4735 	gettimeofday(&tv, 0);
4736 #   else
4737 #     define MEM_LOG_TIME_FMT	"%10d: "
4738 #     define MEM_LOG_TIME_ARG	(int)when
4739         Time_t when;
4740         (void)time(&when);
4741 #   endif
4742 	/* If there are other OS specific ways of hires time than
4743 	 * gettimeofday() (see dist/Time-HiRes), the easiest way is
4744 	 * probably that they would be used to fill in the struct
4745 	 * timeval. */
4746 	{
4747 	    STRLEN len;
4748             const char* endptr;
4749 	    int fd;
4750             UV uv;
4751             if (grok_atoUV(pmlenv, &uv, &endptr) /* Ignore endptr. */
4752                 && uv && uv <= PERL_INT_MAX
4753             ) {
4754                 fd = (int)uv;
4755             } else {
4756 		fd = PERL_MEM_LOG_FD;
4757             }
4758 
4759 	    if (strchr(pmlenv, 't')) {
4760 		len = my_snprintf(buf, sizeof(buf),
4761 				MEM_LOG_TIME_FMT, MEM_LOG_TIME_ARG);
4762 		PERL_UNUSED_RESULT(PerlLIO_write(fd, buf, len));
4763 	    }
4764 	    switch (mlt) {
4765 	    case MLT_ALLOC:
4766 		len = my_snprintf(buf, sizeof(buf),
4767 			"alloc: %s:%d:%s: %" IVdf " %" UVuf
4768 			" %s = %" IVdf ": %" UVxf "\n",
4769 			filename, linenumber, funcname, n, typesize,
4770 			type_name, n * typesize, PTR2UV(newalloc));
4771 		break;
4772 	    case MLT_REALLOC:
4773 		len = my_snprintf(buf, sizeof(buf),
4774 			"realloc: %s:%d:%s: %" IVdf " %" UVuf
4775 			" %s = %" IVdf ": %" UVxf " -> %" UVxf "\n",
4776 			filename, linenumber, funcname, n, typesize,
4777 			type_name, n * typesize, PTR2UV(oldalloc),
4778 			PTR2UV(newalloc));
4779 		break;
4780 	    case MLT_FREE:
4781 		len = my_snprintf(buf, sizeof(buf),
4782 			"free: %s:%d:%s: %" UVxf "\n",
4783 			filename, linenumber, funcname,
4784 			PTR2UV(oldalloc));
4785 		break;
4786 	    case MLT_NEW_SV:
4787 	    case MLT_DEL_SV:
4788 		len = my_snprintf(buf, sizeof(buf),
4789 			"%s_SV: %s:%d:%s: %" UVxf SV_LOG_SERIAL_FMT "\n",
4790 			mlt == MLT_NEW_SV ? "new" : "del",
4791 			filename, linenumber, funcname,
4792 			PTR2UV(sv) _SV_LOG_SERIAL_ARG(sv));
4793 		break;
4794 	    default:
4795 		len = 0;
4796 	    }
4797 	    PERL_UNUSED_RESULT(PerlLIO_write(fd, buf, len));
4798 	}
4799     }
4800 }
4801 #endif /* !PERL_MEM_LOG_NOIMPL */
4802 
4803 #ifndef PERL_MEM_LOG_NOIMPL
4804 # define \
4805     mem_log_common_if(alty, num, tysz, tynm, sv, oal, nal, flnm, ln, fnnm) \
4806     mem_log_common   (alty, num, tysz, tynm, sv, oal, nal, flnm, ln, fnnm)
4807 #else
4808 /* this is suboptimal, but bug compatible.  User is providing their
4809    own implementation, but is getting these functions anyway, and they
4810    do nothing. But _NOIMPL users should be able to cope or fix */
4811 # define \
4812     mem_log_common_if(alty, num, tysz, tynm, u, oal, nal, flnm, ln, fnnm) \
4813     /* mem_log_common_if_PERL_MEM_LOG_NOIMPL */
4814 #endif
4815 
4816 Malloc_t
4817 Perl_mem_log_alloc(const UV n, const UV typesize, const char *type_name,
4818 		   Malloc_t newalloc,
4819 		   const char *filename, const int linenumber,
4820 		   const char *funcname)
4821 {
4822     PERL_ARGS_ASSERT_MEM_LOG_ALLOC;
4823 
4824     mem_log_common_if(MLT_ALLOC, n, typesize, type_name,
4825 		      NULL, NULL, newalloc,
4826 		      filename, linenumber, funcname);
4827     return newalloc;
4828 }
4829 
4830 Malloc_t
4831 Perl_mem_log_realloc(const UV n, const UV typesize, const char *type_name,
4832 		     Malloc_t oldalloc, Malloc_t newalloc,
4833 		     const char *filename, const int linenumber,
4834 		     const char *funcname)
4835 {
4836     PERL_ARGS_ASSERT_MEM_LOG_REALLOC;
4837 
4838     mem_log_common_if(MLT_REALLOC, n, typesize, type_name,
4839 		      NULL, oldalloc, newalloc,
4840 		      filename, linenumber, funcname);
4841     return newalloc;
4842 }
4843 
4844 Malloc_t
4845 Perl_mem_log_free(Malloc_t oldalloc,
4846 		  const char *filename, const int linenumber,
4847 		  const char *funcname)
4848 {
4849     PERL_ARGS_ASSERT_MEM_LOG_FREE;
4850 
4851     mem_log_common_if(MLT_FREE, 0, 0, "", NULL, oldalloc, NULL,
4852 		      filename, linenumber, funcname);
4853     return oldalloc;
4854 }
4855 
4856 void
4857 Perl_mem_log_new_sv(const SV *sv,
4858 		    const char *filename, const int linenumber,
4859 		    const char *funcname)
4860 {
4861     mem_log_common_if(MLT_NEW_SV, 0, 0, "", sv, NULL, NULL,
4862 		      filename, linenumber, funcname);
4863 }
4864 
4865 void
4866 Perl_mem_log_del_sv(const SV *sv,
4867 		    const char *filename, const int linenumber,
4868 		    const char *funcname)
4869 {
4870     mem_log_common_if(MLT_DEL_SV, 0, 0, "", sv, NULL, NULL,
4871 		      filename, linenumber, funcname);
4872 }
4873 
4874 #endif /* PERL_MEM_LOG */
4875 
4876 /*
4877 =for apidoc quadmath_format_single
4878 
4879 C<quadmath_snprintf()> is very strict about its C<format> string and will
4880 fail, returning -1, if the format is invalid.  It accepts exactly
4881 one format spec.
4882 
4883 C<quadmath_format_single()> checks that the intended single spec looks
4884 sane: begins with C<%>, has only one C<%>, ends with C<[efgaEFGA]>,
4885 and has C<Q> before it.  This is not a full "printf syntax check",
4886 just the basics.
4887 
4888 Returns the format if it is valid, NULL if not.
4889 
4890 C<quadmath_format_single()> can and will actually patch in the missing
4891 C<Q>, if necessary.  In this case it will return the modified copy of
4892 the format, B<which the caller will need to free.>
4893 
4894 See also L</quadmath_format_needed>.
4895 
4896 =cut
4897 */
4898 #ifdef USE_QUADMATH
4899 const char*
4900 Perl_quadmath_format_single(const char* format)
4901 {
4902     STRLEN len;
4903 
4904     PERL_ARGS_ASSERT_QUADMATH_FORMAT_SINGLE;
4905 
4906     if (format[0] != '%' || strchr(format + 1, '%'))
4907         return NULL;
4908     len = strlen(format);
4909     /* minimum length three: %Qg */
4910     if (len < 3 || strchr("efgaEFGA", format[len - 1]) == NULL)
4911         return NULL;
4912     if (format[len - 2] != 'Q') {
4913         char* fixed;
4914         Newx(fixed, len + 1, char);
4915         memcpy(fixed, format, len - 1);
4916         fixed[len - 1] = 'Q';
4917         fixed[len    ] = format[len - 1];
4918         fixed[len + 1] = 0;
4919         return (const char*)fixed;
4920     }
4921     return format;
4922 }
4923 #endif
4924 
4925 /*
4926 =for apidoc quadmath_format_needed
4927 
4928 C<quadmath_format_needed()> returns true if the C<format> string seems to
4929 contain at least one non-Q-prefixed C<%[efgaEFGA]> format specifier,
4930 or returns false otherwise.
4931 
4932 The format specifier detection is not complete printf-syntax detection,
4933 but it should catch most common cases.
4934 
4935 If true is returned, those arguments B<should> in theory be processed
4936 with C<quadmath_snprintf()>, but in case there is more than one such
4937 format specifier (see L</quadmath_format_single>), and if there is
4938 anything else beyond that one (even just a single byte), they
4939 B<cannot> be processed because C<quadmath_snprintf()> is very strict,
4940 accepting only one format spec, and nothing else.
4941 In this case, the code should probably fail.
4942 
4943 =cut
4944 */
4945 #ifdef USE_QUADMATH
4946 bool
4947 Perl_quadmath_format_needed(const char* format)
4948 {
4949   const char *p = format;
4950   const char *q;
4951 
4952   PERL_ARGS_ASSERT_QUADMATH_FORMAT_NEEDED;
4953 
4954   while ((q = strchr(p, '%'))) {
4955     q++;
4956     if (*q == '+') /* plus */
4957       q++;
4958     if (*q == '#') /* alt */
4959       q++;
4960     if (*q == '*') /* width */
4961       q++;
4962     else {
4963       if (isDIGIT(*q)) {
4964         while (isDIGIT(*q)) q++;
4965       }
4966     }
4967     if (*q == '.' && (q[1] == '*' || isDIGIT(q[1]))) { /* prec */
4968       q++;
4969       if (*q == '*')
4970         q++;
4971       else
4972         while (isDIGIT(*q)) q++;
4973     }
4974     if (strchr("efgaEFGA", *q)) /* Would have needed 'Q' in front. */
4975       return TRUE;
4976     p = q + 1;
4977   }
4978   return FALSE;
4979 }
4980 #endif
4981 
4982 /*
4983 =for apidoc my_snprintf
4984 
4985 The C library C<snprintf> functionality, if available and
4986 standards-compliant (uses C<vsnprintf>, actually).  However, if the
4987 C<vsnprintf> is not available, will unfortunately use the unsafe
4988 C<vsprintf> which can overrun the buffer (there is an overrun check,
4989 but that may be too late).  Consider using C<sv_vcatpvf> instead, or
4990 getting C<vsnprintf>.
4991 
4992 =cut
4993 */
4994 int
4995 Perl_my_snprintf(char *buffer, const Size_t len, const char *format, ...)
4996 {
4997     int retval = -1;
4998     va_list ap;
4999     PERL_ARGS_ASSERT_MY_SNPRINTF;
5000 #ifndef HAS_VSNPRINTF
5001     PERL_UNUSED_VAR(len);
5002 #endif
5003     va_start(ap, format);
5004 #ifdef USE_QUADMATH
5005     {
5006         const char* qfmt = quadmath_format_single(format);
5007         bool quadmath_valid = FALSE;
5008         if (qfmt) {
5009             /* If the format looked promising, use it as quadmath. */
5010             retval = quadmath_snprintf(buffer, len, qfmt, va_arg(ap, NV));
5011             if (retval == -1) {
5012                 if (qfmt != format) {
5013                     dTHX;
5014                     SAVEFREEPV(qfmt);
5015                 }
5016                 Perl_croak_nocontext("panic: quadmath_snprintf failed, format \"%s\"", qfmt);
5017             }
5018             quadmath_valid = TRUE;
5019             if (qfmt != format)
5020                 Safefree(qfmt);
5021             qfmt = NULL;
5022         }
5023         assert(qfmt == NULL);
5024         /* quadmath_format_single() will return false for example for
5025          * "foo = %g", or simply "%g".  We could handle the %g by
5026          * using quadmath for the NV args.  More complex cases of
5027          * course exist: "foo = %g, bar = %g", or "foo=%Qg" (otherwise
5028          * quadmath-valid but has stuff in front).
5029          *
5030          * Handling the "Q-less" cases right would require walking
5031          * through the va_list and rewriting the format, calling
5032          * quadmath for the NVs, building a new va_list, and then
5033          * letting vsnprintf/vsprintf to take care of the other
5034          * arguments.  This may be doable.
5035          *
5036          * We do not attempt that now.  But for paranoia, we here try
5037          * to detect some common (but not all) cases where the
5038          * "Q-less" %[efgaEFGA] formats are present, and die if
5039          * detected.  This doesn't fix the problem, but it stops the
5040          * vsnprintf/vsprintf pulling doubles off the va_list when
5041          * __float128 NVs should be pulled off instead.
5042          *
5043          * If quadmath_format_needed() returns false, we are reasonably
5044          * certain that we can call vnsprintf() or vsprintf() safely. */
5045         if (!quadmath_valid && quadmath_format_needed(format))
5046           Perl_croak_nocontext("panic: quadmath_snprintf failed, format \"%s\"", format);
5047 
5048     }
5049 #endif
5050     if (retval == -1)
5051 #ifdef HAS_VSNPRINTF
5052         retval = vsnprintf(buffer, len, format, ap);
5053 #else
5054         retval = vsprintf(buffer, format, ap);
5055 #endif
5056     va_end(ap);
5057     /* vsprintf() shows failure with < 0 */
5058     if (retval < 0
5059 #ifdef HAS_VSNPRINTF
5060     /* vsnprintf() shows failure with >= len */
5061         ||
5062         (len > 0 && (Size_t)retval >= len)
5063 #endif
5064     )
5065 	Perl_croak_nocontext("panic: my_snprintf buffer overflow");
5066     return retval;
5067 }
5068 
5069 /*
5070 =for apidoc my_vsnprintf
5071 
5072 The C library C<vsnprintf> if available and standards-compliant.
5073 However, if if the C<vsnprintf> is not available, will unfortunately
5074 use the unsafe C<vsprintf> which can overrun the buffer (there is an
5075 overrun check, but that may be too late).  Consider using
5076 C<sv_vcatpvf> instead, or getting C<vsnprintf>.
5077 
5078 =cut
5079 */
5080 int
5081 Perl_my_vsnprintf(char *buffer, const Size_t len, const char *format, va_list ap)
5082 {
5083 #ifdef USE_QUADMATH
5084     PERL_UNUSED_ARG(buffer);
5085     PERL_UNUSED_ARG(len);
5086     PERL_UNUSED_ARG(format);
5087     /* the cast is to avoid gcc -Wsizeof-array-argument complaining */
5088     PERL_UNUSED_ARG((void*)ap);
5089     Perl_croak_nocontext("panic: my_vsnprintf not available with quadmath");
5090     return 0;
5091 #else
5092     int retval;
5093 #ifdef NEED_VA_COPY
5094     va_list apc;
5095 
5096     PERL_ARGS_ASSERT_MY_VSNPRINTF;
5097     Perl_va_copy(ap, apc);
5098 # ifdef HAS_VSNPRINTF
5099     retval = vsnprintf(buffer, len, format, apc);
5100 # else
5101     PERL_UNUSED_ARG(len);
5102     retval = vsprintf(buffer, format, apc);
5103 # endif
5104     va_end(apc);
5105 #else
5106 # ifdef HAS_VSNPRINTF
5107     retval = vsnprintf(buffer, len, format, ap);
5108 # else
5109     PERL_UNUSED_ARG(len);
5110     retval = vsprintf(buffer, format, ap);
5111 # endif
5112 #endif /* #ifdef NEED_VA_COPY */
5113     /* vsprintf() shows failure with < 0 */
5114     if (retval < 0
5115 #ifdef HAS_VSNPRINTF
5116     /* vsnprintf() shows failure with >= len */
5117         ||
5118         (len > 0 && (Size_t)retval >= len)
5119 #endif
5120     )
5121 	Perl_croak_nocontext("panic: my_vsnprintf buffer overflow");
5122     return retval;
5123 #endif
5124 }
5125 
5126 void
5127 Perl_my_clearenv(pTHX)
5128 {
5129     dVAR;
5130 #if ! defined(PERL_MICRO)
5131 #  if defined(PERL_IMPLICIT_SYS) || defined(WIN32)
5132     PerlEnv_clearenv();
5133 #  else /* ! (PERL_IMPLICIT_SYS || WIN32) */
5134 #    if defined(USE_ENVIRON_ARRAY)
5135 #      if defined(USE_ITHREADS)
5136     /* only the parent thread can clobber the process environment */
5137     if (PL_curinterp == aTHX)
5138 #      endif /* USE_ITHREADS */
5139     {
5140 #      if ! defined(PERL_USE_SAFE_PUTENV)
5141     if ( !PL_use_safe_putenv) {
5142       I32 i;
5143       if (environ == PL_origenviron)
5144         environ = (char**)safesysmalloc(sizeof(char*));
5145       else
5146         for (i = 0; environ[i]; i++)
5147           (void)safesysfree(environ[i]);
5148     }
5149     environ[0] = NULL;
5150 #      else /* PERL_USE_SAFE_PUTENV */
5151 #        if defined(HAS_CLEARENV)
5152     (void)clearenv();
5153 #        elif defined(HAS_UNSETENV)
5154     int bsiz = 80; /* Most envvar names will be shorter than this. */
5155     char *buf = (char*)safesysmalloc(bsiz);
5156     while (*environ != NULL) {
5157       char *e = strchr(*environ, '=');
5158       int l = e ? e - *environ : (int)strlen(*environ);
5159       if (bsiz < l + 1) {
5160         (void)safesysfree(buf);
5161         bsiz = l + 1; /* + 1 for the \0. */
5162         buf = (char*)safesysmalloc(bsiz);
5163       }
5164       memcpy(buf, *environ, l);
5165       buf[l] = '\0';
5166       (void)unsetenv(buf);
5167     }
5168     (void)safesysfree(buf);
5169 #        else /* ! HAS_CLEARENV && ! HAS_UNSETENV */
5170     /* Just null environ and accept the leakage. */
5171     *environ = NULL;
5172 #        endif /* HAS_CLEARENV || HAS_UNSETENV */
5173 #      endif /* ! PERL_USE_SAFE_PUTENV */
5174     }
5175 #    endif /* USE_ENVIRON_ARRAY */
5176 #  endif /* PERL_IMPLICIT_SYS || WIN32 */
5177 #endif /* PERL_MICRO */
5178 }
5179 
5180 #ifdef PERL_IMPLICIT_CONTEXT
5181 
5182 /* Implements the MY_CXT_INIT macro. The first time a module is loaded,
5183 the global PL_my_cxt_index is incremented, and that value is assigned to
5184 that module's static my_cxt_index (who's address is passed as an arg).
5185 Then, for each interpreter this function is called for, it makes sure a
5186 void* slot is available to hang the static data off, by allocating or
5187 extending the interpreter's PL_my_cxt_list array */
5188 
5189 #ifndef PERL_GLOBAL_STRUCT_PRIVATE
5190 void *
5191 Perl_my_cxt_init(pTHX_ int *index, size_t size)
5192 {
5193     dVAR;
5194     void *p;
5195     PERL_ARGS_ASSERT_MY_CXT_INIT;
5196     if (*index == -1) {
5197 	/* this module hasn't been allocated an index yet */
5198 	MUTEX_LOCK(&PL_my_ctx_mutex);
5199 	*index = PL_my_cxt_index++;
5200 	MUTEX_UNLOCK(&PL_my_ctx_mutex);
5201     }
5202 
5203     /* make sure the array is big enough */
5204     if (PL_my_cxt_size <= *index) {
5205 	if (PL_my_cxt_size) {
5206             IV new_size = PL_my_cxt_size;
5207 	    while (new_size <= *index)
5208 		new_size *= 2;
5209 	    Renew(PL_my_cxt_list, new_size, void *);
5210             PL_my_cxt_size = new_size;
5211 	}
5212 	else {
5213 	    PL_my_cxt_size = 16;
5214 	    Newx(PL_my_cxt_list, PL_my_cxt_size, void *);
5215 	}
5216     }
5217     /* newSV() allocates one more than needed */
5218     p = (void*)SvPVX(newSV(size-1));
5219     PL_my_cxt_list[*index] = p;
5220     Zero(p, size, char);
5221     return p;
5222 }
5223 
5224 #else /* #ifndef PERL_GLOBAL_STRUCT_PRIVATE */
5225 
5226 int
5227 Perl_my_cxt_index(pTHX_ const char *my_cxt_key)
5228 {
5229     dVAR;
5230     int index;
5231 
5232     PERL_ARGS_ASSERT_MY_CXT_INDEX;
5233 
5234     for (index = 0; index < PL_my_cxt_index; index++) {
5235 	const char *key = PL_my_cxt_keys[index];
5236 	/* try direct pointer compare first - there are chances to success,
5237 	 * and it's much faster.
5238 	 */
5239 	if ((key == my_cxt_key) || strEQ(key, my_cxt_key))
5240 	    return index;
5241     }
5242     return -1;
5243 }
5244 
5245 void *
5246 Perl_my_cxt_init(pTHX_ const char *my_cxt_key, size_t size)
5247 {
5248     dVAR;
5249     void *p;
5250     int index;
5251 
5252     PERL_ARGS_ASSERT_MY_CXT_INIT;
5253 
5254     index = Perl_my_cxt_index(aTHX_ my_cxt_key);
5255     if (index == -1) {
5256 	/* this module hasn't been allocated an index yet */
5257 	MUTEX_LOCK(&PL_my_ctx_mutex);
5258 	index = PL_my_cxt_index++;
5259 	MUTEX_UNLOCK(&PL_my_ctx_mutex);
5260     }
5261 
5262     /* make sure the array is big enough */
5263     if (PL_my_cxt_size <= index) {
5264 	int old_size = PL_my_cxt_size;
5265 	int i;
5266 	if (PL_my_cxt_size) {
5267             IV new_size = PL_my_cxt_size;
5268 	    while (new_size <= index)
5269 		new_size *= 2;
5270 	    Renew(PL_my_cxt_list, new_size, void *);
5271 	    Renew(PL_my_cxt_keys, new_size, const char *);
5272             PL_my_cxt_size = new_size;
5273 	}
5274 	else {
5275 	    PL_my_cxt_size = 16;
5276 	    Newx(PL_my_cxt_list, PL_my_cxt_size, void *);
5277 	    Newx(PL_my_cxt_keys, PL_my_cxt_size, const char *);
5278 	}
5279 	for (i = old_size; i < PL_my_cxt_size; i++) {
5280 	    PL_my_cxt_keys[i] = 0;
5281 	    PL_my_cxt_list[i] = 0;
5282 	}
5283     }
5284     PL_my_cxt_keys[index] = my_cxt_key;
5285     /* newSV() allocates one more than needed */
5286     p = (void*)SvPVX(newSV(size-1));
5287     PL_my_cxt_list[index] = p;
5288     Zero(p, size, char);
5289     return p;
5290 }
5291 #endif /* #ifndef PERL_GLOBAL_STRUCT_PRIVATE */
5292 #endif /* PERL_IMPLICIT_CONTEXT */
5293 
5294 
5295 /* Perl_xs_handshake():
5296    implement the various XS_*_BOOTCHECK macros, which are added to .c
5297    files by ExtUtils::ParseXS, to check that the perl the module was built
5298    with is binary compatible with the running perl.
5299 
5300    usage:
5301        Perl_xs_handshake(U32 key, void * v_my_perl, const char * file,
5302             [U32 items, U32 ax], [char * api_version], [char * xs_version])
5303 
5304    The meaning of the varargs is determined the U32 key arg (which is not
5305    a format string). The fields of key are assembled by using HS_KEY().
5306 
5307    Under PERL_IMPLICIT_CONTEX, the v_my_perl arg is of type
5308    "PerlInterpreter *" and represents the callers context; otherwise it is
5309    of type "CV *", and is the boot xsub's CV.
5310 
5311    v_my_perl will catch where a threaded future perl526.dll calling IO.dll
5312    for example, and IO.dll was linked with threaded perl524.dll, and both
5313    perl526.dll and perl524.dll are in %PATH and the Win32 DLL loader
5314    successfully can load IO.dll into the process but simultaneously it
5315    loaded an interpreter of a different version into the process, and XS
5316    code will naturally pass SV*s created by perl524.dll for perl526.dll to
5317    use through perl526.dll's my_perl->Istack_base.
5318 
5319    v_my_perl cannot be the first arg, since then 'key' will be out of
5320    place in a threaded vs non-threaded mixup; and analyzing the key
5321    number's bitfields won't reveal the problem, since it will be a valid
5322    key (unthreaded perl) on interp side, but croak will report the XS mod's
5323    key as gibberish (it is really a my_perl ptr) (threaded XS mod); or if
5324    it's a threaded perl and an unthreaded XS module, threaded perl will
5325    look at an uninit C stack or an uninit register to get 'key'
5326    (remember that it assumes that the 1st arg is the interp cxt).
5327 
5328    'file' is the source filename of the caller.
5329 */
5330 
5331 I32
5332 Perl_xs_handshake(const U32 key, void * v_my_perl, const char * file, ...)
5333 {
5334     va_list args;
5335     U32 items, ax;
5336     void * got;
5337     void * need;
5338 #ifdef PERL_IMPLICIT_CONTEXT
5339     dTHX;
5340     tTHX xs_interp;
5341 #else
5342     CV* cv;
5343     SV *** xs_spp;
5344 #endif
5345     PERL_ARGS_ASSERT_XS_HANDSHAKE;
5346     va_start(args, file);
5347 
5348     got = INT2PTR(void*, (UV)(key & HSm_KEY_MATCH));
5349     need = (void *)(HS_KEY(FALSE, FALSE, "", "") & HSm_KEY_MATCH);
5350     if (UNLIKELY(got != need))
5351 	goto bad_handshake;
5352 /* try to catch where a 2nd threaded perl interp DLL is loaded into a process
5353    by a XS DLL compiled against the wrong interl DLL b/c of bad @INC, and the
5354    2nd threaded perl interp DLL never initialized its TLS/PERL_SYS_INIT3 so
5355    dTHX call from 2nd interp DLL can't return the my_perl that pp_entersub
5356    passed to the XS DLL */
5357 #ifdef PERL_IMPLICIT_CONTEXT
5358     xs_interp = (tTHX)v_my_perl;
5359     got = xs_interp;
5360     need = my_perl;
5361 #else
5362 /* try to catch where an unthreaded perl interp DLL (for ex. perl522.dll) is
5363    loaded into a process by a XS DLL built by an unthreaded perl522.dll perl,
5364    but the DynaLoder/Perl that started the process and loaded the XS DLL is
5365    unthreaded perl524.dll, since unthreadeds don't pass my_perl (a unique *)
5366    through pp_entersub, use a unique value (which is a pointer to PL_stack_sp's
5367    location in the unthreaded perl binary) stored in CV * to figure out if this
5368    Perl_xs_handshake was called by the same pp_entersub */
5369     cv = (CV*)v_my_perl;
5370     xs_spp = (SV***)CvHSCXT(cv);
5371     got = xs_spp;
5372     need = &PL_stack_sp;
5373 #endif
5374     if(UNLIKELY(got != need)) {
5375 	bad_handshake:/* recycle branch and string from above */
5376 	if(got != (void *)HSf_NOCHK)
5377 	    noperl_die("%s: loadable library and perl binaries are mismatched"
5378                        " (got handshake key %p, needed %p)\n",
5379 		file, got, need);
5380     }
5381 
5382     if(key & HSf_SETXSUBFN) {     /* this might be called from a module bootstrap */
5383 	SAVEPPTR(PL_xsubfilename);/* which was require'd from a XSUB BEGIN */
5384 	PL_xsubfilename = file;   /* so the old name must be restored for
5385 				     additional XSUBs to register themselves */
5386 	/* XSUBs can't be perl lang/perl5db.pl debugged
5387 	if (PERLDB_LINE_OR_SAVESRC)
5388 	    (void)gv_fetchfile(file); */
5389     }
5390 
5391     if(key & HSf_POPMARK) {
5392 	ax = POPMARK;
5393 	{   SV **mark = PL_stack_base + ax++;
5394 	    {   dSP;
5395 		items = (I32)(SP - MARK);
5396 	    }
5397 	}
5398     } else {
5399 	items = va_arg(args, U32);
5400 	ax = va_arg(args, U32);
5401     }
5402     {
5403 	U32 apiverlen;
5404 	assert(HS_GETAPIVERLEN(key) <= UCHAR_MAX);
5405 	if((apiverlen = HS_GETAPIVERLEN(key))) {
5406 	    char * api_p = va_arg(args, char*);
5407 	    if(apiverlen != sizeof("v" PERL_API_VERSION_STRING)-1
5408 		|| memNE(api_p, "v" PERL_API_VERSION_STRING,
5409 			 sizeof("v" PERL_API_VERSION_STRING)-1))
5410 		Perl_croak_nocontext("Perl API version %s of %" SVf " does not match %s",
5411 				    api_p, SVfARG(PL_stack_base[ax + 0]),
5412 				    "v" PERL_API_VERSION_STRING);
5413 	}
5414     }
5415     {
5416 	U32 xsverlen;
5417 	assert(HS_GETXSVERLEN(key) <= UCHAR_MAX && HS_GETXSVERLEN(key) <= HS_APIVERLEN_MAX);
5418 	if((xsverlen = HS_GETXSVERLEN(key)))
5419 	    S_xs_version_bootcheck(aTHX_
5420 		items, ax, va_arg(args, char*), xsverlen);
5421     }
5422     va_end(args);
5423     return ax;
5424 }
5425 
5426 
5427 STATIC void
5428 S_xs_version_bootcheck(pTHX_ U32 items, U32 ax, const char *xs_p,
5429 			  STRLEN xs_len)
5430 {
5431     SV *sv;
5432     const char *vn = NULL;
5433     SV *const module = PL_stack_base[ax];
5434 
5435     PERL_ARGS_ASSERT_XS_VERSION_BOOTCHECK;
5436 
5437     if (items >= 2)	 /* version supplied as bootstrap arg */
5438 	sv = PL_stack_base[ax + 1];
5439     else {
5440 	/* XXX GV_ADDWARN */
5441 	vn = "XS_VERSION";
5442 	sv = get_sv(Perl_form(aTHX_ "%" SVf "::%s", SVfARG(module), vn), 0);
5443 	if (!sv || !SvOK(sv)) {
5444 	    vn = "VERSION";
5445 	    sv = get_sv(Perl_form(aTHX_ "%" SVf "::%s", SVfARG(module), vn), 0);
5446 	}
5447     }
5448     if (sv) {
5449 	SV *xssv = Perl_newSVpvn_flags(aTHX_ xs_p, xs_len, SVs_TEMP);
5450 	SV *pmsv = sv_isobject(sv) && sv_derived_from(sv, "version")
5451 	    ? sv : sv_2mortal(new_version(sv));
5452 	xssv = upg_version(xssv, 0);
5453 	if ( vcmp(pmsv,xssv) ) {
5454 	    SV *string = vstringify(xssv);
5455 	    SV *xpt = Perl_newSVpvf(aTHX_ "%" SVf " object version %" SVf
5456 				    " does not match ", SVfARG(module), SVfARG(string));
5457 
5458 	    SvREFCNT_dec(string);
5459 	    string = vstringify(pmsv);
5460 
5461 	    if (vn) {
5462 		Perl_sv_catpvf(aTHX_ xpt, "$%" SVf "::%s %" SVf, SVfARG(module), vn,
5463 			       SVfARG(string));
5464 	    } else {
5465 		Perl_sv_catpvf(aTHX_ xpt, "bootstrap parameter %" SVf, SVfARG(string));
5466 	    }
5467 	    SvREFCNT_dec(string);
5468 
5469 	    Perl_sv_2mortal(aTHX_ xpt);
5470 	    Perl_croak_sv(aTHX_ xpt);
5471 	}
5472     }
5473 }
5474 
5475 /*
5476 =for apidoc my_strlcat
5477 
5478 The C library C<strlcat> if available, or a Perl implementation of it.
5479 This operates on C C<NUL>-terminated strings.
5480 
5481 C<my_strlcat()> appends string C<src> to the end of C<dst>.  It will append at
5482 most S<C<size - strlen(dst) - 1>> characters.  It will then C<NUL>-terminate,
5483 unless C<size> is 0 or the original C<dst> string was longer than C<size> (in
5484 practice this should not happen as it means that either C<size> is incorrect or
5485 that C<dst> is not a proper C<NUL>-terminated string).
5486 
5487 Note that C<size> is the full size of the destination buffer and
5488 the result is guaranteed to be C<NUL>-terminated if there is room.  Note that
5489 room for the C<NUL> should be included in C<size>.
5490 
5491 The return value is the total length that C<dst> would have if C<size> is
5492 sufficiently large.  Thus it is the initial length of C<dst> plus the length of
5493 C<src>.  If C<size> is smaller than the return, the excess was not appended.
5494 
5495 =cut
5496 
5497 Description stolen from http://man.openbsd.org/strlcat.3
5498 */
5499 #ifndef HAS_STRLCAT
5500 Size_t
5501 Perl_my_strlcat(char *dst, const char *src, Size_t size)
5502 {
5503     Size_t used, length, copy;
5504 
5505     used = strlen(dst);
5506     length = strlen(src);
5507     if (size > 0 && used < size - 1) {
5508         copy = (length >= size - used) ? size - used - 1 : length;
5509         memcpy(dst + used, src, copy);
5510         dst[used + copy] = '\0';
5511     }
5512     return used + length;
5513 }
5514 #endif
5515 
5516 
5517 /*
5518 =for apidoc my_strlcpy
5519 
5520 The C library C<strlcpy> if available, or a Perl implementation of it.
5521 This operates on C C<NUL>-terminated strings.
5522 
5523 C<my_strlcpy()> copies up to S<C<size - 1>> characters from the string C<src>
5524 to C<dst>, C<NUL>-terminating the result if C<size> is not 0.
5525 
5526 The return value is the total length C<src> would be if the copy completely
5527 succeeded.  If it is larger than C<size>, the excess was not copied.
5528 
5529 =cut
5530 
5531 Description stolen from http://man.openbsd.org/strlcpy.3
5532 */
5533 #ifndef HAS_STRLCPY
5534 Size_t
5535 Perl_my_strlcpy(char *dst, const char *src, Size_t size)
5536 {
5537     Size_t length, copy;
5538 
5539     length = strlen(src);
5540     if (size > 0) {
5541         copy = (length >= size) ? size - 1 : length;
5542         memcpy(dst, src, copy);
5543         dst[copy] = '\0';
5544     }
5545     return length;
5546 }
5547 #endif
5548 
5549 /*
5550 =for apidoc my_strnlen
5551 
5552 The C library C<strnlen> if available, or a Perl implementation of it.
5553 
5554 C<my_strnlen()> computes the length of the string, up to C<maxlen>
5555 characters.  It will will never attempt to address more than C<maxlen>
5556 characters, making it suitable for use with strings that are not
5557 guaranteed to be NUL-terminated.
5558 
5559 =cut
5560 
5561 Description stolen from http://man.openbsd.org/strnlen.3,
5562 implementation stolen from PostgreSQL.
5563 */
5564 #ifndef HAS_STRNLEN
5565 Size_t
5566 Perl_my_strnlen(const char *str, Size_t maxlen)
5567 {
5568     const char *p = str;
5569 
5570     PERL_ARGS_ASSERT_MY_STRNLEN;
5571 
5572     while(maxlen-- && *p)
5573         p++;
5574 
5575     return p - str;
5576 }
5577 #endif
5578 
5579 #if defined(_MSC_VER) && (_MSC_VER >= 1300) && (_MSC_VER < 1400) && (WINVER < 0x0500)
5580 /* VC7 or 7.1, building with pre-VC7 runtime libraries. */
5581 long _ftol( double ); /* Defined by VC6 C libs. */
5582 long _ftol2( double dblSource ) { return _ftol( dblSource ); }
5583 #endif
5584 
5585 PERL_STATIC_INLINE bool
5586 S_gv_has_usable_name(pTHX_ GV *gv)
5587 {
5588     GV **gvp;
5589     return GvSTASH(gv)
5590 	&& HvENAME(GvSTASH(gv))
5591 	&& (gvp = (GV **)hv_fetchhek(
5592 			GvSTASH(gv), GvNAME_HEK(gv), 0
5593 	   ))
5594 	&& *gvp == gv;
5595 }
5596 
5597 void
5598 Perl_get_db_sub(pTHX_ SV **svp, CV *cv)
5599 {
5600     SV * const dbsv = GvSVn(PL_DBsub);
5601     const bool save_taint = TAINT_get;
5602 
5603     /* When we are called from pp_goto (svp is null),
5604      * we do not care about using dbsv to call CV;
5605      * it's for informational purposes only.
5606      */
5607 
5608     PERL_ARGS_ASSERT_GET_DB_SUB;
5609 
5610     TAINT_set(FALSE);
5611     save_item(dbsv);
5612     if (!PERLDB_SUB_NN) {
5613 	GV *gv = CvGV(cv);
5614 
5615 	if (!svp && !CvLEXICAL(cv)) {
5616 	    gv_efullname3(dbsv, gv, NULL);
5617 	}
5618 	else if ( (CvFLAGS(cv) & (CVf_ANON | CVf_CLONED)) || CvLEXICAL(cv)
5619 	     || strEQ(GvNAME(gv), "END")
5620 	     || ( /* Could be imported, and old sub redefined. */
5621 		 (GvCV(gv) != cv || !S_gv_has_usable_name(aTHX_ gv))
5622 		 &&
5623 		 !( (SvTYPE(*svp) == SVt_PVGV)
5624 		    && (GvCV((const GV *)*svp) == cv)
5625 		    /* Use GV from the stack as a fallback. */
5626 		    && S_gv_has_usable_name(aTHX_ gv = (GV *)*svp)
5627 		  )
5628 		)
5629 	) {
5630 	    /* GV is potentially non-unique, or contain different CV. */
5631 	    SV * const tmp = newRV(MUTABLE_SV(cv));
5632 	    sv_setsv(dbsv, tmp);
5633 	    SvREFCNT_dec(tmp);
5634 	}
5635 	else {
5636 	    sv_sethek(dbsv, HvENAME_HEK(GvSTASH(gv)));
5637 	    sv_catpvs(dbsv, "::");
5638 	    sv_cathek(dbsv, GvNAME_HEK(gv));
5639 	}
5640     }
5641     else {
5642 	const int type = SvTYPE(dbsv);
5643 	if (type < SVt_PVIV && type != SVt_IV)
5644 	    sv_upgrade(dbsv, SVt_PVIV);
5645 	(void)SvIOK_on(dbsv);
5646 	SvIV_set(dbsv, PTR2IV(cv));	/* Do it the quickest way  */
5647     }
5648     SvSETMAGIC(dbsv);
5649     TAINT_IF(save_taint);
5650 #ifdef NO_TAINT_SUPPORT
5651     PERL_UNUSED_VAR(save_taint);
5652 #endif
5653 }
5654 
5655 int
5656 Perl_my_dirfd(DIR * dir) {
5657 
5658     /* Most dirfd implementations have problems when passed NULL. */
5659     if(!dir)
5660         return -1;
5661 #ifdef HAS_DIRFD
5662     return dirfd(dir);
5663 #elif defined(HAS_DIR_DD_FD)
5664     return dir->dd_fd;
5665 #else
5666     Perl_croak_nocontext(PL_no_func, "dirfd");
5667     NOT_REACHED; /* NOTREACHED */
5668     return 0;
5669 #endif
5670 }
5671 
5672 #if !defined(HAS_MKOSTEMP) || !defined(HAS_MKSTEMP)
5673 
5674 #define TEMP_FILE_CH "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvxyz0123456789"
5675 #define TEMP_FILE_CH_COUNT (sizeof(TEMP_FILE_CH)-1)
5676 
5677 static int
5678 S_my_mkostemp(char *templte, int flags) {
5679     dTHX;
5680     STRLEN len = strlen(templte);
5681     int fd;
5682     int attempts = 0;
5683 
5684     if (len < 6 ||
5685         templte[len-1] != 'X' || templte[len-2] != 'X' || templte[len-3] != 'X' ||
5686         templte[len-4] != 'X' || templte[len-5] != 'X' || templte[len-6] != 'X') {
5687         SETERRNO(EINVAL, LIB_INVARG);
5688         return -1;
5689     }
5690 
5691     do {
5692         int i;
5693         for (i = 1; i <= 6; ++i) {
5694             templte[len-i] = TEMP_FILE_CH[(int)(Perl_internal_drand48() * TEMP_FILE_CH_COUNT)];
5695         }
5696         fd = PerlLIO_open3(templte, O_RDWR | O_CREAT | O_EXCL | flags, 0600);
5697     } while (fd == -1 && errno == EEXIST && ++attempts <= 100);
5698 
5699     return fd;
5700 }
5701 
5702 #endif
5703 
5704 #ifndef HAS_MKOSTEMP
5705 int
5706 Perl_my_mkostemp(char *templte, int flags)
5707 {
5708     PERL_ARGS_ASSERT_MY_MKOSTEMP;
5709     return S_my_mkostemp(templte, flags);
5710 }
5711 #endif
5712 
5713 #ifndef HAS_MKSTEMP
5714 int
5715 Perl_my_mkstemp(char *templte)
5716 {
5717     PERL_ARGS_ASSERT_MY_MKSTEMP;
5718     return S_my_mkostemp(templte, 0);
5719 }
5720 #endif
5721 
5722 REGEXP *
5723 Perl_get_re_arg(pTHX_ SV *sv) {
5724 
5725     if (sv) {
5726         if (SvMAGICAL(sv))
5727             mg_get(sv);
5728         if (SvROK(sv))
5729 	    sv = MUTABLE_SV(SvRV(sv));
5730         if (SvTYPE(sv) == SVt_REGEXP)
5731             return (REGEXP*) sv;
5732     }
5733 
5734     return NULL;
5735 }
5736 
5737 /*
5738  * This code is derived from drand48() implementation from FreeBSD,
5739  * found in lib/libc/gen/_rand48.c.
5740  *
5741  * The U64 implementation is original, based on the POSIX
5742  * specification for drand48().
5743  */
5744 
5745 /*
5746 * Copyright (c) 1993 Martin Birgmeier
5747 * All rights reserved.
5748 *
5749 * You may redistribute unmodified or modified versions of this source
5750 * code provided that the above copyright notice and this and the
5751 * following conditions are retained.
5752 *
5753 * This software is provided ``as is'', and comes with no warranties
5754 * of any kind. I shall in no event be liable for anything that happens
5755 * to anyone/anything when using this software.
5756 */
5757 
5758 #define FREEBSD_DRAND48_SEED_0   (0x330e)
5759 
5760 #ifdef PERL_DRAND48_QUAD
5761 
5762 #define DRAND48_MULT UINT64_C(0x5deece66d)
5763 #define DRAND48_ADD  0xb
5764 #define DRAND48_MASK UINT64_C(0xffffffffffff)
5765 
5766 #else
5767 
5768 #define FREEBSD_DRAND48_SEED_1   (0xabcd)
5769 #define FREEBSD_DRAND48_SEED_2   (0x1234)
5770 #define FREEBSD_DRAND48_MULT_0   (0xe66d)
5771 #define FREEBSD_DRAND48_MULT_1   (0xdeec)
5772 #define FREEBSD_DRAND48_MULT_2   (0x0005)
5773 #define FREEBSD_DRAND48_ADD      (0x000b)
5774 
5775 const unsigned short _rand48_mult[3] = {
5776                 FREEBSD_DRAND48_MULT_0,
5777                 FREEBSD_DRAND48_MULT_1,
5778                 FREEBSD_DRAND48_MULT_2
5779 };
5780 const unsigned short _rand48_add = FREEBSD_DRAND48_ADD;
5781 
5782 #endif
5783 
5784 void
5785 Perl_drand48_init_r(perl_drand48_t *random_state, U32 seed)
5786 {
5787     PERL_ARGS_ASSERT_DRAND48_INIT_R;
5788 
5789 #ifdef PERL_DRAND48_QUAD
5790     *random_state = FREEBSD_DRAND48_SEED_0 + ((U64)seed << 16);
5791 #else
5792     random_state->seed[0] = FREEBSD_DRAND48_SEED_0;
5793     random_state->seed[1] = (U16) seed;
5794     random_state->seed[2] = (U16) (seed >> 16);
5795 #endif
5796 }
5797 
5798 double
5799 Perl_drand48_r(perl_drand48_t *random_state)
5800 {
5801     PERL_ARGS_ASSERT_DRAND48_R;
5802 
5803 #ifdef PERL_DRAND48_QUAD
5804     *random_state = (*random_state * DRAND48_MULT + DRAND48_ADD)
5805         & DRAND48_MASK;
5806 
5807     return ldexp((double)*random_state, -48);
5808 #else
5809     {
5810     U32 accu;
5811     U16 temp[2];
5812 
5813     accu = (U32) _rand48_mult[0] * (U32) random_state->seed[0]
5814          + (U32) _rand48_add;
5815     temp[0] = (U16) accu;        /* lower 16 bits */
5816     accu >>= sizeof(U16) * 8;
5817     accu += (U32) _rand48_mult[0] * (U32) random_state->seed[1]
5818           + (U32) _rand48_mult[1] * (U32) random_state->seed[0];
5819     temp[1] = (U16) accu;        /* middle 16 bits */
5820     accu >>= sizeof(U16) * 8;
5821     accu += _rand48_mult[0] * random_state->seed[2]
5822           + _rand48_mult[1] * random_state->seed[1]
5823           + _rand48_mult[2] * random_state->seed[0];
5824     random_state->seed[0] = temp[0];
5825     random_state->seed[1] = temp[1];
5826     random_state->seed[2] = (U16) accu;
5827 
5828     return ldexp((double) random_state->seed[0], -48) +
5829            ldexp((double) random_state->seed[1], -32) +
5830            ldexp((double) random_state->seed[2], -16);
5831     }
5832 #endif
5833 }
5834 
5835 #ifdef USE_C_BACKTRACE
5836 
5837 /* Possibly move all this USE_C_BACKTRACE code into a new file. */
5838 
5839 #ifdef USE_BFD
5840 
5841 typedef struct {
5842     /* abfd is the BFD handle. */
5843     bfd* abfd;
5844     /* bfd_syms is the BFD symbol table. */
5845     asymbol** bfd_syms;
5846     /* bfd_text is handle to the the ".text" section of the object file. */
5847     asection* bfd_text;
5848     /* Since opening the executable and scanning its symbols is quite
5849      * heavy operation, we remember the filename we used the last time,
5850      * and do the opening and scanning only if the filename changes.
5851      * This removes most (but not all) open+scan cycles. */
5852     const char* fname_prev;
5853 } bfd_context;
5854 
5855 /* Given a dl_info, update the BFD context if necessary. */
5856 static void bfd_update(bfd_context* ctx, Dl_info* dl_info)
5857 {
5858     /* BFD open and scan only if the filename changed. */
5859     if (ctx->fname_prev == NULL ||
5860         strNE(dl_info->dli_fname, ctx->fname_prev)) {
5861         if (ctx->abfd) {
5862             bfd_close(ctx->abfd);
5863         }
5864         ctx->abfd = bfd_openr(dl_info->dli_fname, 0);
5865         if (ctx->abfd) {
5866             if (bfd_check_format(ctx->abfd, bfd_object)) {
5867                 IV symbol_size = bfd_get_symtab_upper_bound(ctx->abfd);
5868                 if (symbol_size > 0) {
5869                     Safefree(ctx->bfd_syms);
5870                     Newx(ctx->bfd_syms, symbol_size, asymbol*);
5871                     ctx->bfd_text =
5872                         bfd_get_section_by_name(ctx->abfd, ".text");
5873                 }
5874                 else
5875                     ctx->abfd = NULL;
5876             }
5877             else
5878                 ctx->abfd = NULL;
5879         }
5880         ctx->fname_prev = dl_info->dli_fname;
5881     }
5882 }
5883 
5884 /* Given a raw frame, try to symbolize it and store
5885  * symbol information (source file, line number) away. */
5886 static void bfd_symbolize(bfd_context* ctx,
5887                           void* raw_frame,
5888                           char** symbol_name,
5889                           STRLEN* symbol_name_size,
5890                           char** source_name,
5891                           STRLEN* source_name_size,
5892                           STRLEN* source_line)
5893 {
5894     *symbol_name = NULL;
5895     *symbol_name_size = 0;
5896     if (ctx->abfd) {
5897         IV offset = PTR2IV(raw_frame) - PTR2IV(ctx->bfd_text->vma);
5898         if (offset > 0 &&
5899             bfd_canonicalize_symtab(ctx->abfd, ctx->bfd_syms) > 0) {
5900             const char *file;
5901             const char *func;
5902             unsigned int line = 0;
5903             if (bfd_find_nearest_line(ctx->abfd, ctx->bfd_text,
5904                                       ctx->bfd_syms, offset,
5905                                       &file, &func, &line) &&
5906                 file && func && line > 0) {
5907                 /* Size and copy the source file, use only
5908                  * the basename of the source file.
5909                  *
5910                  * NOTE: the basenames are fine for the
5911                  * Perl source files, but may not always
5912                  * be the best idea for XS files. */
5913                 const char *p, *b = NULL;
5914                 /* Look for the last slash. */
5915                 for (p = file; *p; p++) {
5916                     if (*p == '/')
5917                         b = p + 1;
5918                 }
5919                 if (b == NULL || *b == 0) {
5920                     b = file;
5921                 }
5922                 *source_name_size = p - b + 1;
5923                 Newx(*source_name, *source_name_size + 1, char);
5924                 Copy(b, *source_name, *source_name_size + 1, char);
5925 
5926                 *symbol_name_size = strlen(func);
5927                 Newx(*symbol_name, *symbol_name_size + 1, char);
5928                 Copy(func, *symbol_name, *symbol_name_size + 1, char);
5929 
5930                 *source_line = line;
5931             }
5932         }
5933     }
5934 }
5935 
5936 #endif /* #ifdef USE_BFD */
5937 
5938 #ifdef PERL_DARWIN
5939 
5940 /* OS X has no public API for for 'symbolicating' (Apple official term)
5941  * stack addresses to {function_name, source_file, line_number}.
5942  * Good news: there is command line utility atos(1) which does that.
5943  * Bad news 1: it's a command line utility.
5944  * Bad news 2: one needs to have the Developer Tools installed.
5945  * Bad news 3: in newer releases it needs to be run as 'xcrun atos'.
5946  *
5947  * To recap: we need to open a pipe for reading for a utility which
5948  * might not exist, or exists in different locations, and then parse
5949  * the output.  And since this is all for a low-level API, we cannot
5950  * use high-level stuff.  Thanks, Apple. */
5951 
5952 typedef struct {
5953     /* tool is set to the absolute pathname of the tool to use:
5954      * xcrun or atos. */
5955     const char* tool;
5956     /* format is set to a printf format string used for building
5957      * the external command to run. */
5958     const char* format;
5959     /* unavail is set if e.g. xcrun cannot be found, or something
5960      * else happens that makes getting the backtrace dubious.  Note,
5961      * however, that the context isn't persistent, the next call to
5962      * get_c_backtrace() will start from scratch. */
5963     bool unavail;
5964     /* fname is the current object file name. */
5965     const char* fname;
5966     /* object_base_addr is the base address of the shared object. */
5967     void* object_base_addr;
5968 } atos_context;
5969 
5970 /* Given |dl_info|, updates the context.  If the context has been
5971  * marked unavailable, return immediately.  If not but the tool has
5972  * not been set, set it to either "xcrun atos" or "atos" (also set the
5973  * format to use for creating commands for piping), or if neither is
5974  * unavailable (one needs the Developer Tools installed), mark the context
5975  * an unavailable.  Finally, update the filename (object name),
5976  * and its base address. */
5977 
5978 static void atos_update(atos_context* ctx,
5979                         Dl_info* dl_info)
5980 {
5981     if (ctx->unavail)
5982         return;
5983     if (ctx->tool == NULL) {
5984         const char* tools[] = {
5985             "/usr/bin/xcrun",
5986             "/usr/bin/atos"
5987         };
5988         const char* formats[] = {
5989             "/usr/bin/xcrun atos -o '%s' -l %08x %08x 2>&1",
5990             "/usr/bin/atos -d -o '%s' -l %08x %08x 2>&1"
5991         };
5992         struct stat st;
5993         UV i;
5994         for (i = 0; i < C_ARRAY_LENGTH(tools); i++) {
5995             if (stat(tools[i], &st) == 0 && S_ISREG(st.st_mode)) {
5996                 ctx->tool = tools[i];
5997                 ctx->format = formats[i];
5998                 break;
5999             }
6000         }
6001         if (ctx->tool == NULL) {
6002             ctx->unavail = TRUE;
6003             return;
6004         }
6005     }
6006     if (ctx->fname == NULL ||
6007         strNE(dl_info->dli_fname, ctx->fname)) {
6008         ctx->fname = dl_info->dli_fname;
6009         ctx->object_base_addr = dl_info->dli_fbase;
6010     }
6011 }
6012 
6013 /* Given an output buffer end |p| and its |start|, matches
6014  * for the atos output, extracting the source code location
6015  * and returning non-NULL if possible, returning NULL otherwise. */
6016 static const char* atos_parse(const char* p,
6017                               const char* start,
6018                               STRLEN* source_name_size,
6019                               STRLEN* source_line) {
6020     /* atos() output is something like:
6021      * perl_parse (in miniperl) (perl.c:2314)\n\n".
6022      * We cannot use Perl regular expressions, because we need to
6023      * stay low-level.  Therefore here we have a rolled-out version
6024      * of a state machine which matches _backwards_from_the_end_ and
6025      * if there's a success, returns the starts of the filename,
6026      * also setting the filename size and the source line number.
6027      * The matched regular expression is roughly "\(.*:\d+\)\s*$" */
6028     const char* source_number_start;
6029     const char* source_name_end;
6030     const char* source_line_end;
6031     const char* close_paren;
6032     UV uv;
6033 
6034     /* Skip trailing whitespace. */
6035     while (p > start && isSPACE(*p)) p--;
6036     /* Now we should be at the close paren. */
6037     if (p == start || *p != ')')
6038         return NULL;
6039     close_paren = p;
6040     p--;
6041     /* Now we should be in the line number. */
6042     if (p == start || !isDIGIT(*p))
6043         return NULL;
6044     /* Skip over the digits. */
6045     while (p > start && isDIGIT(*p))
6046         p--;
6047     /* Now we should be at the colon. */
6048     if (p == start || *p != ':')
6049         return NULL;
6050     source_number_start = p + 1;
6051     source_name_end = p; /* Just beyond the end. */
6052     p--;
6053     /* Look for the open paren. */
6054     while (p > start && *p != '(')
6055         p--;
6056     if (p == start)
6057         return NULL;
6058     p++;
6059     *source_name_size = source_name_end - p;
6060     if (grok_atoUV(source_number_start, &uv,  &source_line_end)
6061         && source_line_end == close_paren
6062         && uv <= PERL_INT_MAX
6063     ) {
6064         *source_line = (STRLEN)uv;
6065         return p;
6066     }
6067     return NULL;
6068 }
6069 
6070 /* Given a raw frame, read a pipe from the symbolicator (that's the
6071  * technical term) atos, reads the result, and parses the source code
6072  * location.  We must stay low-level, so we use snprintf(), pipe(),
6073  * and fread(), and then also parse the output ourselves. */
6074 static void atos_symbolize(atos_context* ctx,
6075                            void* raw_frame,
6076                            char** source_name,
6077                            STRLEN* source_name_size,
6078                            STRLEN* source_line)
6079 {
6080     char cmd[1024];
6081     const char* p;
6082     Size_t cnt;
6083 
6084     if (ctx->unavail)
6085         return;
6086     /* Simple security measure: if there's any funny business with
6087      * the object name (used as "-o '%s'" ), leave since at least
6088      * partially the user controls it. */
6089     for (p = ctx->fname; *p; p++) {
6090         if (*p == '\'' || isCNTRL(*p)) {
6091             ctx->unavail = TRUE;
6092             return;
6093         }
6094     }
6095     cnt = snprintf(cmd, sizeof(cmd), ctx->format,
6096                    ctx->fname, ctx->object_base_addr, raw_frame);
6097     if (cnt < sizeof(cmd)) {
6098         /* Undo nostdio.h #defines that disable stdio.
6099          * This is somewhat naughty, but is used elsewhere
6100          * in the core, and affects only OS X. */
6101 #undef FILE
6102 #undef popen
6103 #undef fread
6104 #undef pclose
6105         FILE* fp = popen(cmd, "r");
6106         /* At the moment we open a new pipe for each stack frame.
6107          * This is naturally somewhat slow, but hopefully generating
6108          * stack traces is never going to in a performance critical path.
6109          *
6110          * We could play tricks with atos by batching the stack
6111          * addresses to be resolved: atos can either take multiple
6112          * addresses from the command line, or read addresses from
6113          * a file (though the mess of creating temporary files would
6114          * probably negate much of any possible speedup).
6115          *
6116          * Normally there are only two objects present in the backtrace:
6117          * perl itself, and the libdyld.dylib.  (Note that the object
6118          * filenames contain the full pathname, so perl may not always
6119          * be in the same place.)  Whenever the object in the
6120          * backtrace changes, the base address also changes.
6121          *
6122          * The problem with batching the addresses, though, would be
6123          * matching the results with the addresses: the parsing of
6124          * the results is already painful enough with a single address. */
6125         if (fp) {
6126             char out[1024];
6127             UV cnt = fread(out, 1, sizeof(out), fp);
6128             if (cnt < sizeof(out)) {
6129                 const char* p = atos_parse(out + cnt - 1, out,
6130                                            source_name_size,
6131                                            source_line);
6132                 if (p) {
6133                     Newx(*source_name,
6134                          *source_name_size, char);
6135                     Copy(p, *source_name,
6136                          *source_name_size,  char);
6137                 }
6138             }
6139             pclose(fp);
6140         }
6141     }
6142 }
6143 
6144 #endif /* #ifdef PERL_DARWIN */
6145 
6146 /*
6147 =for apidoc get_c_backtrace
6148 
6149 Collects the backtrace (aka "stacktrace") into a single linear
6150 malloced buffer, which the caller B<must> C<Perl_free_c_backtrace()>.
6151 
6152 Scans the frames back by S<C<depth + skip>>, then drops the C<skip> innermost,
6153 returning at most C<depth> frames.
6154 
6155 =cut
6156 */
6157 
6158 Perl_c_backtrace*
6159 Perl_get_c_backtrace(pTHX_ int depth, int skip)
6160 {
6161     /* Note that here we must stay as low-level as possible: Newx(),
6162      * Copy(), Safefree(); since we may be called from anywhere,
6163      * so we should avoid higher level constructs like SVs or AVs.
6164      *
6165      * Since we are using safesysmalloc() via Newx(), don't try
6166      * getting backtrace() there, unless you like deep recursion. */
6167 
6168     /* Currently only implemented with backtrace() and dladdr(),
6169      * for other platforms NULL is returned. */
6170 
6171 #if defined(HAS_BACKTRACE) && defined(HAS_DLADDR)
6172     /* backtrace() is available via <execinfo.h> in glibc and in most
6173      * modern BSDs; dladdr() is available via <dlfcn.h>. */
6174 
6175     /* We try fetching this many frames total, but then discard
6176      * the |skip| first ones.  For the remaining ones we will try
6177      * retrieving more information with dladdr(). */
6178     int try_depth = skip +  depth;
6179 
6180     /* The addresses (program counters) returned by backtrace(). */
6181     void** raw_frames;
6182 
6183     /* Retrieved with dladdr() from the addresses returned by backtrace(). */
6184     Dl_info* dl_infos;
6185 
6186     /* Sizes _including_ the terminating \0 of the object name
6187      * and symbol name strings. */
6188     STRLEN* object_name_sizes;
6189     STRLEN* symbol_name_sizes;
6190 
6191 #ifdef USE_BFD
6192     /* The symbol names comes either from dli_sname,
6193      * or if using BFD, they can come from BFD. */
6194     char** symbol_names;
6195 #endif
6196 
6197     /* The source code location information.  Dug out with e.g. BFD. */
6198     char** source_names;
6199     STRLEN* source_name_sizes;
6200     STRLEN* source_lines;
6201 
6202     Perl_c_backtrace* bt = NULL;  /* This is what will be returned. */
6203     int got_depth; /* How many frames were returned from backtrace(). */
6204     UV frame_count = 0; /* How many frames we return. */
6205     UV total_bytes = 0; /* The size of the whole returned backtrace. */
6206 
6207 #ifdef USE_BFD
6208     bfd_context bfd_ctx;
6209 #endif
6210 #ifdef PERL_DARWIN
6211     atos_context atos_ctx;
6212 #endif
6213 
6214     /* Here are probably possibilities for optimizing.  We could for
6215      * example have a struct that contains most of these and then
6216      * allocate |try_depth| of them, saving a bunch of malloc calls.
6217      * Note, however, that |frames| could not be part of that struct
6218      * because backtrace() will want an array of just them.  Also be
6219      * careful about the name strings. */
6220     Newx(raw_frames, try_depth, void*);
6221     Newx(dl_infos, try_depth, Dl_info);
6222     Newx(object_name_sizes, try_depth, STRLEN);
6223     Newx(symbol_name_sizes, try_depth, STRLEN);
6224     Newx(source_names, try_depth, char*);
6225     Newx(source_name_sizes, try_depth, STRLEN);
6226     Newx(source_lines, try_depth, STRLEN);
6227 #ifdef USE_BFD
6228     Newx(symbol_names, try_depth, char*);
6229 #endif
6230 
6231     /* Get the raw frames. */
6232     got_depth = (int)backtrace(raw_frames, try_depth);
6233 
6234     /* We use dladdr() instead of backtrace_symbols() because we want
6235      * the full details instead of opaque strings.  This is useful for
6236      * two reasons: () the details are needed for further symbolic
6237      * digging, for example in OS X (2) by having the details we fully
6238      * control the output, which in turn is useful when more platforms
6239      * are added: we can keep out output "portable". */
6240 
6241     /* We want a single linear allocation, which can then be freed
6242      * with a single swoop.  We will do the usual trick of first
6243      * walking over the structure and seeing how much we need to
6244      * allocate, then allocating, and then walking over the structure
6245      * the second time and populating it. */
6246 
6247     /* First we must compute the total size of the buffer. */
6248     total_bytes = sizeof(Perl_c_backtrace_header);
6249     if (got_depth > skip) {
6250         int i;
6251 #ifdef USE_BFD
6252         bfd_init(); /* Is this safe to call multiple times? */
6253         Zero(&bfd_ctx, 1, bfd_context);
6254 #endif
6255 #ifdef PERL_DARWIN
6256         Zero(&atos_ctx, 1, atos_context);
6257 #endif
6258         for (i = skip; i < try_depth; i++) {
6259             Dl_info* dl_info = &dl_infos[i];
6260 
6261             object_name_sizes[i] = 0;
6262             source_names[i] = NULL;
6263             source_name_sizes[i] = 0;
6264             source_lines[i] = 0;
6265 
6266             /* Yes, zero from dladdr() is failure. */
6267             if (dladdr(raw_frames[i], dl_info)) {
6268                 total_bytes += sizeof(Perl_c_backtrace_frame);
6269 
6270                 object_name_sizes[i] =
6271                     dl_info->dli_fname ? strlen(dl_info->dli_fname) : 0;
6272                 symbol_name_sizes[i] =
6273                     dl_info->dli_sname ? strlen(dl_info->dli_sname) : 0;
6274 #ifdef USE_BFD
6275                 bfd_update(&bfd_ctx, dl_info);
6276                 bfd_symbolize(&bfd_ctx, raw_frames[i],
6277                               &symbol_names[i],
6278                               &symbol_name_sizes[i],
6279                               &source_names[i],
6280                               &source_name_sizes[i],
6281                               &source_lines[i]);
6282 #endif
6283 #if PERL_DARWIN
6284                 atos_update(&atos_ctx, dl_info);
6285                 atos_symbolize(&atos_ctx,
6286                                raw_frames[i],
6287                                &source_names[i],
6288                                &source_name_sizes[i],
6289                                &source_lines[i]);
6290 #endif
6291 
6292                 /* Plus ones for the terminating \0. */
6293                 total_bytes += object_name_sizes[i] + 1;
6294                 total_bytes += symbol_name_sizes[i] + 1;
6295                 total_bytes += source_name_sizes[i] + 1;
6296 
6297                 frame_count++;
6298             } else {
6299                 break;
6300             }
6301         }
6302 #ifdef USE_BFD
6303         Safefree(bfd_ctx.bfd_syms);
6304 #endif
6305     }
6306 
6307     /* Now we can allocate and populate the result buffer. */
6308     Newxc(bt, total_bytes, char, Perl_c_backtrace);
6309     Zero(bt, total_bytes, char);
6310     bt->header.frame_count = frame_count;
6311     bt->header.total_bytes = total_bytes;
6312     if (frame_count > 0) {
6313         Perl_c_backtrace_frame* frame = bt->frame_info;
6314         char* name_base = (char *)(frame + frame_count);
6315         char* name_curr = name_base; /* Outputting the name strings here. */
6316         UV i;
6317         for (i = skip; i < skip + frame_count; i++) {
6318             Dl_info* dl_info = &dl_infos[i];
6319 
6320             frame->addr = raw_frames[i];
6321             frame->object_base_addr = dl_info->dli_fbase;
6322             frame->symbol_addr = dl_info->dli_saddr;
6323 
6324             /* Copies a string, including the \0, and advances the name_curr.
6325              * Also copies the start and the size to the frame. */
6326 #define PERL_C_BACKTRACE_STRCPY(frame, doffset, src, dsize, size) \
6327             if (size && src) \
6328                 Copy(src, name_curr, size, char); \
6329             frame->doffset = name_curr - (char*)bt; \
6330             frame->dsize = size; \
6331             name_curr += size; \
6332             *name_curr++ = 0;
6333 
6334             PERL_C_BACKTRACE_STRCPY(frame, object_name_offset,
6335                                     dl_info->dli_fname,
6336                                     object_name_size, object_name_sizes[i]);
6337 
6338 #ifdef USE_BFD
6339             PERL_C_BACKTRACE_STRCPY(frame, symbol_name_offset,
6340                                     symbol_names[i],
6341                                     symbol_name_size, symbol_name_sizes[i]);
6342             Safefree(symbol_names[i]);
6343 #else
6344             PERL_C_BACKTRACE_STRCPY(frame, symbol_name_offset,
6345                                     dl_info->dli_sname,
6346                                     symbol_name_size, symbol_name_sizes[i]);
6347 #endif
6348 
6349             PERL_C_BACKTRACE_STRCPY(frame, source_name_offset,
6350                                     source_names[i],
6351                                     source_name_size, source_name_sizes[i]);
6352             Safefree(source_names[i]);
6353 
6354 #undef PERL_C_BACKTRACE_STRCPY
6355 
6356             frame->source_line_number = source_lines[i];
6357 
6358             frame++;
6359         }
6360         assert(total_bytes ==
6361                (UV)(sizeof(Perl_c_backtrace_header) +
6362                     frame_count * sizeof(Perl_c_backtrace_frame) +
6363                     name_curr - name_base));
6364     }
6365 #ifdef USE_BFD
6366     Safefree(symbol_names);
6367     if (bfd_ctx.abfd) {
6368         bfd_close(bfd_ctx.abfd);
6369     }
6370 #endif
6371     Safefree(source_lines);
6372     Safefree(source_name_sizes);
6373     Safefree(source_names);
6374     Safefree(symbol_name_sizes);
6375     Safefree(object_name_sizes);
6376     /* Assuming the strings returned by dladdr() are pointers
6377      * to read-only static memory (the object file), so that
6378      * they do not need freeing (and cannot be). */
6379     Safefree(dl_infos);
6380     Safefree(raw_frames);
6381     return bt;
6382 #else
6383     PERL_UNUSED_ARGV(depth);
6384     PERL_UNUSED_ARGV(skip);
6385     return NULL;
6386 #endif
6387 }
6388 
6389 /*
6390 =for apidoc free_c_backtrace
6391 
6392 Deallocates a backtrace received from get_c_bracktrace.
6393 
6394 =cut
6395 */
6396 
6397 /*
6398 =for apidoc get_c_backtrace_dump
6399 
6400 Returns a SV containing a dump of C<depth> frames of the call stack, skipping
6401 the C<skip> innermost ones.  C<depth> of 20 is usually enough.
6402 
6403 The appended output looks like:
6404 
6405 ...
6406 1   10e004812:0082   Perl_croak   util.c:1716    /usr/bin/perl
6407 2   10df8d6d2:1d72   perl_parse   perl.c:3975    /usr/bin/perl
6408 ...
6409 
6410 The fields are tab-separated.  The first column is the depth (zero
6411 being the innermost non-skipped frame).  In the hex:offset, the hex is
6412 where the program counter was in C<S_parse_body>, and the :offset (might
6413 be missing) tells how much inside the C<S_parse_body> the program counter was.
6414 
6415 The C<util.c:1716> is the source code file and line number.
6416 
6417 The F</usr/bin/perl> is obvious (hopefully).
6418 
6419 Unknowns are C<"-">.  Unknowns can happen unfortunately quite easily:
6420 if the platform doesn't support retrieving the information;
6421 if the binary is missing the debug information;
6422 if the optimizer has transformed the code by for example inlining.
6423 
6424 =cut
6425 */
6426 
6427 SV*
6428 Perl_get_c_backtrace_dump(pTHX_ int depth, int skip)
6429 {
6430     Perl_c_backtrace* bt;
6431 
6432     bt = get_c_backtrace(depth, skip + 1 /* Hide ourselves. */);
6433     if (bt) {
6434         Perl_c_backtrace_frame* frame;
6435         SV* dsv = newSVpvs("");
6436         UV i;
6437         for (i = 0, frame = bt->frame_info;
6438              i < bt->header.frame_count; i++, frame++) {
6439             Perl_sv_catpvf(aTHX_ dsv, "%d", (int)i);
6440             Perl_sv_catpvf(aTHX_ dsv, "\t%p", frame->addr ? frame->addr : "-");
6441             /* Symbol (function) names might disappear without debug info.
6442              *
6443              * The source code location might disappear in case of the
6444              * optimizer inlining or otherwise rearranging the code. */
6445             if (frame->symbol_addr) {
6446                 Perl_sv_catpvf(aTHX_ dsv, ":%04x",
6447                                (int)
6448                                ((char*)frame->addr - (char*)frame->symbol_addr));
6449             }
6450             Perl_sv_catpvf(aTHX_ dsv, "\t%s",
6451                            frame->symbol_name_size &&
6452                            frame->symbol_name_offset ?
6453                            (char*)bt + frame->symbol_name_offset : "-");
6454             if (frame->source_name_size &&
6455                 frame->source_name_offset &&
6456                 frame->source_line_number) {
6457                 Perl_sv_catpvf(aTHX_ dsv, "\t%s:%" UVuf,
6458                                (char*)bt + frame->source_name_offset,
6459                                (UV)frame->source_line_number);
6460             } else {
6461                 Perl_sv_catpvf(aTHX_ dsv, "\t-");
6462             }
6463             Perl_sv_catpvf(aTHX_ dsv, "\t%s",
6464                            frame->object_name_size &&
6465                            frame->object_name_offset ?
6466                            (char*)bt + frame->object_name_offset : "-");
6467             /* The frame->object_base_addr is not output,
6468              * but it is used for symbolizing/symbolicating. */
6469             sv_catpvs(dsv, "\n");
6470         }
6471 
6472         Perl_free_c_backtrace(bt);
6473 
6474         return dsv;
6475     }
6476 
6477     return NULL;
6478 }
6479 
6480 /*
6481 =for apidoc dump_c_backtrace
6482 
6483 Dumps the C backtrace to the given C<fp>.
6484 
6485 Returns true if a backtrace could be retrieved, false if not.
6486 
6487 =cut
6488 */
6489 
6490 bool
6491 Perl_dump_c_backtrace(pTHX_ PerlIO* fp, int depth, int skip)
6492 {
6493     SV* sv;
6494 
6495     PERL_ARGS_ASSERT_DUMP_C_BACKTRACE;
6496 
6497     sv = Perl_get_c_backtrace_dump(aTHX_ depth, skip);
6498     if (sv) {
6499         sv_2mortal(sv);
6500         PerlIO_printf(fp, "%s", SvPV_nolen(sv));
6501         return TRUE;
6502     }
6503     return FALSE;
6504 }
6505 
6506 #endif /* #ifdef USE_C_BACKTRACE */
6507 
6508 #ifdef PERL_TSA_ACTIVE
6509 
6510 /* pthread_mutex_t and perl_mutex are typedef equivalent
6511  * so casting the pointers is fine. */
6512 
6513 int perl_tsa_mutex_lock(perl_mutex* mutex)
6514 {
6515     return pthread_mutex_lock((pthread_mutex_t *) mutex);
6516 }
6517 
6518 int perl_tsa_mutex_unlock(perl_mutex* mutex)
6519 {
6520     return pthread_mutex_unlock((pthread_mutex_t *) mutex);
6521 }
6522 
6523 int perl_tsa_mutex_destroy(perl_mutex* mutex)
6524 {
6525     return pthread_mutex_destroy((pthread_mutex_t *) mutex);
6526 }
6527 
6528 #endif
6529 
6530 
6531 #ifdef USE_DTRACE
6532 
6533 /* log a sub call or return */
6534 
6535 void
6536 Perl_dtrace_probe_call(pTHX_ CV *cv, bool is_call)
6537 {
6538     const char *func;
6539     const char *file;
6540     const char *stash;
6541     const COP  *start;
6542     line_t      line;
6543 
6544     PERL_ARGS_ASSERT_DTRACE_PROBE_CALL;
6545 
6546     if (CvNAMED(cv)) {
6547         HEK *hek = CvNAME_HEK(cv);
6548         func = HEK_KEY(hek);
6549     }
6550     else {
6551         GV  *gv = CvGV(cv);
6552         func = GvENAME(gv);
6553     }
6554     start = (const COP *)CvSTART(cv);
6555     file  = CopFILE(start);
6556     line  = CopLINE(start);
6557     stash = CopSTASHPV(start);
6558 
6559     if (is_call) {
6560         PERL_SUB_ENTRY(func, file, line, stash);
6561     }
6562     else {
6563         PERL_SUB_RETURN(func, file, line, stash);
6564     }
6565 }
6566 
6567 
6568 /* log a require file loading/loaded  */
6569 
6570 void
6571 Perl_dtrace_probe_load(pTHX_ const char *name, bool is_loading)
6572 {
6573     PERL_ARGS_ASSERT_DTRACE_PROBE_LOAD;
6574 
6575     if (is_loading) {
6576 	PERL_LOADING_FILE(name);
6577     }
6578     else {
6579 	PERL_LOADED_FILE(name);
6580     }
6581 }
6582 
6583 
6584 /* log an op execution */
6585 
6586 void
6587 Perl_dtrace_probe_op(pTHX_ const OP *op)
6588 {
6589     PERL_ARGS_ASSERT_DTRACE_PROBE_OP;
6590 
6591     PERL_OP_ENTRY(OP_NAME(op));
6592 }
6593 
6594 
6595 /* log a compile/run phase change */
6596 
6597 void
6598 Perl_dtrace_probe_phase(pTHX_ enum perl_phase phase)
6599 {
6600     const char *ph_old = PL_phase_names[PL_phase];
6601     const char *ph_new = PL_phase_names[phase];
6602 
6603     PERL_PHASE_CHANGE(ph_new, ph_old);
6604 }
6605 
6606 #endif
6607 
6608 /*
6609  * ex: set ts=8 sts=4 sw=4 et:
6610  */
6611