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2012-11-06 Bernard Banner <banner@adacore.com>
[thirdparty/gcc.git] / gcc / ada / init.c
1 /****************************************************************************
2 * *
3 * GNAT COMPILER COMPONENTS *
4 * *
5 * I N I T *
6 * *
7 * C Implementation File *
8 * *
9 * Copyright (C) 1992-2012, Free Software Foundation, Inc. *
10 * *
11 * GNAT is free software; you can redistribute it and/or modify it under *
12 * terms of the GNU General Public License as published by the Free Soft- *
13 * ware Foundation; either version 3, or (at your option) any later ver- *
14 * sion. GNAT is distributed in the hope that it will be useful, but WITH- *
15 * OUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY *
16 * or FITNESS FOR A PARTICULAR PURPOSE. *
17 * *
18 * As a special exception under Section 7 of GPL version 3, you are granted *
19 * additional permissions described in the GCC Runtime Library Exception, *
20 * version 3.1, as published by the Free Software Foundation. *
21 * *
22 * You should have received a copy of the GNU General Public License and *
23 * a copy of the GCC Runtime Library Exception along with this program; *
24 * see the files COPYING3 and COPYING.RUNTIME respectively. If not, see *
25 * <http://www.gnu.org/licenses/>. *
26 * *
27 * GNAT was originally developed by the GNAT team at New York University. *
28 * Extensive contributions were provided by Ada Core Technologies Inc. *
29 * *
30 ****************************************************************************/
31
32 /* This unit contains initialization circuits that are system dependent.
33 A major part of the functionality involves stack overflow checking.
34 The GCC backend generates probe instructions to test for stack overflow.
35 For details on the exact approach used to generate these probes, see the
36 "Using and Porting GCC" manual, in particular the "Stack Checking" section
37 and the subsection "Specifying How Stack Checking is Done". The handlers
38 installed by this file are used to catch the resulting signals that come
39 from these probes failing (i.e. touching protected pages). */
40
41 #ifdef __cplusplus
42 extern "C" {
43 #endif
44
45 /* This file should be kept synchronized with 2sinit.ads, 2sinit.adb,
46 s-init-ae653-cert.adb and s-init-xi-sparc.adb. All these files implement
47 the required functionality for different targets. */
48
49 /* The following include is here to meet the published VxWorks requirement
50 that the __vxworks header appear before any other include. */
51 #ifdef __vxworks
52 #include "vxWorks.h"
53 #endif
54
55 #ifdef __ANDROID__
56 #undef linux
57 #endif
58
59 #ifdef IN_RTS
60 #include "tconfig.h"
61 #include "tsystem.h"
62 #include <sys/stat.h>
63
64 /* We don't have libiberty, so use malloc. */
65 #define xmalloc(S) malloc (S)
66 #else
67 #include "config.h"
68 #include "system.h"
69 #endif
70
71 #include "adaint.h"
72 #include "raise.h"
73
74 extern void __gnat_raise_program_error (const char *, int);
75
76 /* Addresses of exception data blocks for predefined exceptions. Tasking_Error
77 is not used in this unit, and the abort signal is only used on IRIX.
78 ??? Revisit this part since IRIX is no longer supported. */
79 extern struct Exception_Data constraint_error;
80 extern struct Exception_Data numeric_error;
81 extern struct Exception_Data program_error;
82 extern struct Exception_Data storage_error;
83
84 /* For the Cert run time we use the regular raise exception routine because
85 Raise_From_Signal_Handler is not available. */
86 #ifdef CERT
87 #define Raise_From_Signal_Handler \
88 __gnat_raise_exception
89 extern void Raise_From_Signal_Handler (struct Exception_Data *, const char *);
90 #else
91 #define Raise_From_Signal_Handler \
92 ada__exceptions__raise_from_signal_handler
93 extern void Raise_From_Signal_Handler (struct Exception_Data *, const char *);
94 #endif
95
96 /* Global values computed by the binder. */
97 int __gl_main_priority = -1;
98 int __gl_main_cpu = -1;
99 int __gl_time_slice_val = -1;
100 char __gl_wc_encoding = 'n';
101 char __gl_locking_policy = ' ';
102 char __gl_queuing_policy = ' ';
103 char __gl_task_dispatching_policy = ' ';
104 char *__gl_priority_specific_dispatching = 0;
105 int __gl_num_specific_dispatching = 0;
106 char *__gl_interrupt_states = 0;
107 int __gl_num_interrupt_states = 0;
108 int __gl_unreserve_all_interrupts = 0;
109 int __gl_exception_tracebacks = 0;
110 int __gl_detect_blocking = 0;
111 int __gl_default_stack_size = -1;
112 int __gl_leap_seconds_support = 0;
113 int __gl_canonical_streams = 0;
114
115 /* This value is not used anymore, but kept for bootstrapping purpose. */
116 int __gl_zero_cost_exceptions = 0;
117
118 /* Indication of whether synchronous signal handler has already been
119 installed by a previous call to adainit. */
120 int __gnat_handler_installed = 0;
121
122 #ifndef IN_RTS
123 int __gnat_inside_elab_final_code = 0;
124 /* ??? This variable is obsolete since 2001-08-29 but is kept to allow
125 bootstrap from old GNAT versions (< 3.15). */
126 #endif
127
128 /* HAVE_GNAT_INIT_FLOAT must be set on every targets where a __gnat_init_float
129 is defined. If this is not set then a void implementation will be defined
130 at the end of this unit. */
131 #undef HAVE_GNAT_INIT_FLOAT
132
133 /******************************/
134 /* __gnat_get_interrupt_state */
135 /******************************/
136
137 char __gnat_get_interrupt_state (int);
138
139 /* This routine is called from the runtime as needed to determine the state
140 of an interrupt, as set by an Interrupt_State pragma appearing anywhere
141 in the current partition. The input argument is the interrupt number,
142 and the result is one of the following:
143
144 'n' this interrupt not set by any Interrupt_State pragma
145 'u' Interrupt_State pragma set state to User
146 'r' Interrupt_State pragma set state to Runtime
147 's' Interrupt_State pragma set state to System */
148
149 char
150 __gnat_get_interrupt_state (int intrup)
151 {
152 if (intrup >= __gl_num_interrupt_states)
153 return 'n';
154 else
155 return __gl_interrupt_states [intrup];
156 }
157
158 /***********************************/
159 /* __gnat_get_specific_dispatching */
160 /***********************************/
161
162 char __gnat_get_specific_dispatching (int);
163
164 /* This routine is called from the runtime as needed to determine the
165 priority specific dispatching policy, as set by a
166 Priority_Specific_Dispatching pragma appearing anywhere in the current
167 partition. The input argument is the priority number, and the result
168 is the upper case first character of the policy name, e.g. 'F' for
169 FIFO_Within_Priorities. A space ' ' is returned if no
170 Priority_Specific_Dispatching pragma is used in the partition. */
171
172 char
173 __gnat_get_specific_dispatching (int priority)
174 {
175 if (__gl_num_specific_dispatching == 0)
176 return ' ';
177 else if (priority >= __gl_num_specific_dispatching)
178 return 'F';
179 else
180 return __gl_priority_specific_dispatching [priority];
181 }
182
183 #ifndef IN_RTS
184
185 /**********************/
186 /* __gnat_set_globals */
187 /**********************/
188
189 /* This routine is kept for bootstrapping purposes, since the binder generated
190 file now sets the __gl_* variables directly. */
191
192 void
193 __gnat_set_globals (void)
194 {
195 }
196
197 #endif
198
199 /***************/
200 /* AIX Section */
201 /***************/
202
203 #if defined (_AIX)
204
205 #include <signal.h>
206 #include <sys/time.h>
207
208 /* Some versions of AIX don't define SA_NODEFER. */
209
210 #ifndef SA_NODEFER
211 #define SA_NODEFER 0
212 #endif /* SA_NODEFER */
213
214 /* Versions of AIX before 4.3 don't have nanosleep but provide
215 nsleep instead. */
216
217 #ifndef _AIXVERSION_430
218
219 extern int nanosleep (struct timestruc_t *, struct timestruc_t *);
220
221 int
222 nanosleep (struct timestruc_t *Rqtp, struct timestruc_t *Rmtp)
223 {
224 return nsleep (Rqtp, Rmtp);
225 }
226
227 #endif /* _AIXVERSION_430 */
228
229 /* Version of AIX before 5.3 don't have pthread_condattr_setclock:
230 * supply it as a weak symbol here so that if linking on a 5.3 or newer
231 * machine, we get the real one.
232 */
233
234 #ifndef _AIXVERSION_530
235 #pragma weak pthread_condattr_setclock
236 int
237 pthread_condattr_setclock (pthread_condattr_t *attr, clockid_t cl) {
238 return 0;
239 }
240 #endif
241
242 static void
243 __gnat_error_handler (int sig,
244 siginfo_t *si ATTRIBUTE_UNUSED,
245 void *ucontext ATTRIBUTE_UNUSED)
246 {
247 struct Exception_Data *exception;
248 const char *msg;
249
250 switch (sig)
251 {
252 case SIGSEGV:
253 /* FIXME: we need to detect the case of a *real* SIGSEGV. */
254 exception = &storage_error;
255 msg = "stack overflow or erroneous memory access";
256 break;
257
258 case SIGBUS:
259 exception = &constraint_error;
260 msg = "SIGBUS";
261 break;
262
263 case SIGFPE:
264 exception = &constraint_error;
265 msg = "SIGFPE";
266 break;
267
268 default:
269 exception = &program_error;
270 msg = "unhandled signal";
271 }
272
273 Raise_From_Signal_Handler (exception, msg);
274 }
275
276 void
277 __gnat_install_handler (void)
278 {
279 struct sigaction act;
280
281 /* Set up signal handler to map synchronous signals to appropriate
282 exceptions. Make sure that the handler isn't interrupted by another
283 signal that might cause a scheduling event! */
284
285 act.sa_flags = SA_NODEFER | SA_RESTART | SA_SIGINFO;
286 act.sa_sigaction = __gnat_error_handler;
287 sigemptyset (&act.sa_mask);
288
289 /* Do not install handlers if interrupt state is "System". */
290 if (__gnat_get_interrupt_state (SIGABRT) != 's')
291 sigaction (SIGABRT, &act, NULL);
292 if (__gnat_get_interrupt_state (SIGFPE) != 's')
293 sigaction (SIGFPE, &act, NULL);
294 if (__gnat_get_interrupt_state (SIGILL) != 's')
295 sigaction (SIGILL, &act, NULL);
296 if (__gnat_get_interrupt_state (SIGSEGV) != 's')
297 sigaction (SIGSEGV, &act, NULL);
298 if (__gnat_get_interrupt_state (SIGBUS) != 's')
299 sigaction (SIGBUS, &act, NULL);
300
301 __gnat_handler_installed = 1;
302 }
303
304 /*****************/
305 /* HP-UX section */
306 /*****************/
307
308 #elif defined (__hpux__)
309
310 #include <signal.h>
311 #include <sys/ucontext.h>
312
313 #if defined (IN_RTS) && defined (__ia64__)
314
315 #include <sys/uc_access.h>
316
317 #define HAVE_GNAT_ADJUST_CONTEXT_FOR_RAISE
318
319 void
320 __gnat_adjust_context_for_raise (int signo ATTRIBUTE_UNUSED, void *ucontext)
321 {
322 ucontext_t *uc = (ucontext_t *) ucontext;
323 uint64_t ip;
324
325 /* Adjust on itanium, as GetIPInfo is not supported. */
326 __uc_get_ip (uc, &ip);
327 __uc_set_ip (uc, ip + 1);
328 }
329 #endif /* IN_RTS && __ia64__ */
330
331 /* Tasking and Non-tasking signal handler. Map SIGnal to Ada exception
332 propagation after the required low level adjustments. */
333
334 static void
335 __gnat_error_handler (int sig,
336 siginfo_t *si ATTRIBUTE_UNUSED,
337 void *ucontext ATTRIBUTE_UNUSED)
338 {
339 struct Exception_Data *exception;
340 const char *msg;
341
342 __gnat_adjust_context_for_raise (sig, ucontext);
343
344 switch (sig)
345 {
346 case SIGSEGV:
347 /* FIXME: we need to detect the case of a *real* SIGSEGV. */
348 exception = &storage_error;
349 msg = "stack overflow or erroneous memory access";
350 break;
351
352 case SIGBUS:
353 exception = &constraint_error;
354 msg = "SIGBUS";
355 break;
356
357 case SIGFPE:
358 exception = &constraint_error;
359 msg = "SIGFPE";
360 break;
361
362 default:
363 exception = &program_error;
364 msg = "unhandled signal";
365 }
366
367 Raise_From_Signal_Handler (exception, msg);
368 }
369
370 /* This must be in keeping with System.OS_Interface.Alternate_Stack_Size. */
371 #if defined (__hppa__)
372 char __gnat_alternate_stack[16 * 1024]; /* 2 * SIGSTKSZ */
373 #else
374 char __gnat_alternate_stack[128 * 1024]; /* MINSIGSTKSZ */
375 #endif
376
377 void
378 __gnat_install_handler (void)
379 {
380 struct sigaction act;
381
382 /* Set up signal handler to map synchronous signals to appropriate
383 exceptions. Make sure that the handler isn't interrupted by another
384 signal that might cause a scheduling event! Also setup an alternate
385 stack region for the handler execution so that stack overflows can be
386 handled properly, avoiding a SEGV generation from stack usage by the
387 handler itself. */
388
389 stack_t stack;
390 stack.ss_sp = __gnat_alternate_stack;
391 stack.ss_size = sizeof (__gnat_alternate_stack);
392 stack.ss_flags = 0;
393 sigaltstack (&stack, NULL);
394
395 act.sa_sigaction = __gnat_error_handler;
396 act.sa_flags = SA_NODEFER | SA_RESTART | SA_SIGINFO;
397 sigemptyset (&act.sa_mask);
398
399 /* Do not install handlers if interrupt state is "System". */
400 if (__gnat_get_interrupt_state (SIGABRT) != 's')
401 sigaction (SIGABRT, &act, NULL);
402 if (__gnat_get_interrupt_state (SIGFPE) != 's')
403 sigaction (SIGFPE, &act, NULL);
404 if (__gnat_get_interrupt_state (SIGILL) != 's')
405 sigaction (SIGILL, &act, NULL);
406 if (__gnat_get_interrupt_state (SIGBUS) != 's')
407 sigaction (SIGBUS, &act, NULL);
408 act.sa_flags |= SA_ONSTACK;
409 if (__gnat_get_interrupt_state (SIGSEGV) != 's')
410 sigaction (SIGSEGV, &act, NULL);
411
412 __gnat_handler_installed = 1;
413 }
414
415 /*********************/
416 /* GNU/Linux Section */
417 /*********************/
418
419 #elif defined (linux)
420
421 #include <signal.h>
422
423 #define __USE_GNU 1 /* required to get REG_EIP/RIP from glibc's ucontext.h */
424 #include <sys/ucontext.h>
425
426 /* GNU/Linux, which uses glibc, does not define NULL in included
427 header files. */
428
429 #if !defined (NULL)
430 #define NULL ((void *) 0)
431 #endif
432
433 #if defined (MaRTE)
434
435 /* MaRTE OS provides its own version of sigaction, sigfillset, and
436 sigemptyset (overriding these symbol names). We want to make sure that
437 the versions provided by the underlying C library are used here (these
438 versions are renamed by MaRTE to linux_sigaction, fake_linux_sigfillset,
439 and fake_linux_sigemptyset, respectively). The MaRTE library will not
440 always be present (it will not be linked if no tasking constructs are
441 used), so we use the weak symbol mechanism to point always to the symbols
442 defined within the C library. */
443
444 #pragma weak linux_sigaction
445 int linux_sigaction (int signum, const struct sigaction *act,
446 struct sigaction *oldact) {
447 return sigaction (signum, act, oldact);
448 }
449 #define sigaction(signum, act, oldact) linux_sigaction (signum, act, oldact)
450
451 #pragma weak fake_linux_sigfillset
452 void fake_linux_sigfillset (sigset_t *set) {
453 sigfillset (set);
454 }
455 #define sigfillset(set) fake_linux_sigfillset (set)
456
457 #pragma weak fake_linux_sigemptyset
458 void fake_linux_sigemptyset (sigset_t *set) {
459 sigemptyset (set);
460 }
461 #define sigemptyset(set) fake_linux_sigemptyset (set)
462
463 #endif
464
465 #if defined (i386) || defined (__x86_64__) || defined (__ia64__)
466
467 #define HAVE_GNAT_ADJUST_CONTEXT_FOR_RAISE
468
469 void
470 __gnat_adjust_context_for_raise (int signo ATTRIBUTE_UNUSED, void *ucontext)
471 {
472 mcontext_t *mcontext = &((ucontext_t *) ucontext)->uc_mcontext;
473
474 /* On the i386 and x86-64 architectures, stack checking is performed by
475 means of probes with moving stack pointer, that is to say the probed
476 address is always the value of the stack pointer. Upon hitting the
477 guard page, the stack pointer therefore points to an inaccessible
478 address and an alternate signal stack is needed to run the handler.
479 But there is an additional twist: on these architectures, the EH
480 return code writes the address of the handler at the target CFA's
481 value on the stack before doing the jump. As a consequence, if
482 there is an active handler in the frame whose stack has overflowed,
483 the stack pointer must nevertheless point to an accessible address
484 by the time the EH return is executed.
485
486 We therefore adjust the saved value of the stack pointer by the size
487 of one page + a small dope of 4 words, in order to make sure that it
488 points to an accessible address in case it's used as the target CFA.
489 The stack checking code guarantees that this address is unused by the
490 time this happens. */
491
492 #if defined (i386)
493 unsigned long *pc = (unsigned long *)mcontext->gregs[REG_EIP];
494 /* The pattern is "orl $0x0,(%esp)" for a probe in 32-bit mode. */
495 if (signo == SIGSEGV && pc && *pc == 0x00240c83)
496 mcontext->gregs[REG_ESP] += 4096 + 4 * sizeof (unsigned long);
497 #elif defined (__x86_64__)
498 unsigned long long *pc = (unsigned long long *)mcontext->gregs[REG_RIP];
499 if (signo == SIGSEGV && pc
500 /* The pattern is "orq $0x0,(%rsp)" for a probe in 64-bit mode. */
501 && ((*pc & 0xffffffffffLL) == 0x00240c8348LL
502 /* The pattern may also be "orl $0x0,(%esp)" for a probe in
503 x32 mode. */
504 || (*pc & 0xffffffffLL) == 0x00240c83LL))
505 mcontext->gregs[REG_RSP] += 4096 + 4 * sizeof (unsigned long);
506 #elif defined (__ia64__)
507 /* ??? The IA-64 unwinder doesn't compensate for signals. */
508 mcontext->sc_ip++;
509 #endif
510 }
511
512 #endif
513
514 static void
515 __gnat_error_handler (int sig, siginfo_t *si ATTRIBUTE_UNUSED, void *ucontext)
516 {
517 struct Exception_Data *exception;
518 const char *msg;
519
520 /* Adjusting is required for every fault context, so adjust for this one
521 now, before we possibly trigger a recursive fault below. */
522 __gnat_adjust_context_for_raise (sig, ucontext);
523
524 switch (sig)
525 {
526 case SIGSEGV:
527 /* Here we would like a discrimination test to see whether the page
528 before the faulting address is accessible. Unfortunately, Linux
529 seems to have no way of giving us the faulting address.
530
531 In old versions of init.c, we had a test of the page before the
532 stack pointer:
533
534 ((volatile char *)
535 ((long) si->esp_at_signal & - getpagesize ()))[getpagesize ()];
536
537 but that's wrong since it tests the stack pointer location and the
538 stack probing code may not move it until all probes succeed.
539
540 For now we simply do not attempt any discrimination at all. Note
541 that this is quite acceptable, since a "real" SIGSEGV can only
542 occur as the result of an erroneous program. */
543 exception = &storage_error;
544 msg = "stack overflow or erroneous memory access";
545 break;
546
547 case SIGBUS:
548 exception = &storage_error;
549 msg = "SIGBUS: possible stack overflow";
550 break;
551
552 case SIGFPE:
553 exception = &constraint_error;
554 msg = "SIGFPE";
555 break;
556
557 default:
558 exception = &program_error;
559 msg = "unhandled signal";
560 }
561
562 Raise_From_Signal_Handler (exception, msg);
563 }
564
565 #if defined (i386) || defined (__x86_64__) || defined (__powerpc__)
566 /* This must be in keeping with System.OS_Interface.Alternate_Stack_Size. */
567 char __gnat_alternate_stack[16 * 1024]; /* 2 * SIGSTKSZ */
568 #endif
569
570 #ifdef __XENO__
571 #include <sys/mman.h>
572 #include <native/task.h>
573
574 RT_TASK main_task;
575 #endif
576
577 void
578 __gnat_install_handler (void)
579 {
580 struct sigaction act;
581
582 #ifdef __XENO__
583 int prio;
584
585 if (__gl_main_priority == -1)
586 prio = 49;
587 else
588 prio = __gl_main_priority;
589
590 /* Avoid memory swapping for this program */
591
592 mlockall (MCL_CURRENT|MCL_FUTURE);
593
594 /* Turn the current Linux task into a native Xenomai task */
595
596 rt_task_shadow(&main_task, "environment_task", prio, T_FPU);
597 #endif
598
599 /* Set up signal handler to map synchronous signals to appropriate
600 exceptions. Make sure that the handler isn't interrupted by another
601 signal that might cause a scheduling event! Also setup an alternate
602 stack region for the handler execution so that stack overflows can be
603 handled properly, avoiding a SEGV generation from stack usage by the
604 handler itself. */
605
606 #if defined (i386) || defined (__x86_64__) || defined (__powerpc__)
607 stack_t stack;
608 stack.ss_sp = __gnat_alternate_stack;
609 stack.ss_size = sizeof (__gnat_alternate_stack);
610 stack.ss_flags = 0;
611 sigaltstack (&stack, NULL);
612 #endif
613
614 act.sa_sigaction = __gnat_error_handler;
615 act.sa_flags = SA_NODEFER | SA_RESTART | SA_SIGINFO;
616 sigemptyset (&act.sa_mask);
617
618 /* Do not install handlers if interrupt state is "System". */
619 if (__gnat_get_interrupt_state (SIGABRT) != 's')
620 sigaction (SIGABRT, &act, NULL);
621 if (__gnat_get_interrupt_state (SIGFPE) != 's')
622 sigaction (SIGFPE, &act, NULL);
623 if (__gnat_get_interrupt_state (SIGILL) != 's')
624 sigaction (SIGILL, &act, NULL);
625 if (__gnat_get_interrupt_state (SIGBUS) != 's')
626 sigaction (SIGBUS, &act, NULL);
627 #if defined (i386) || defined (__x86_64__) || defined (__powerpc__)
628 act.sa_flags |= SA_ONSTACK;
629 #endif
630 if (__gnat_get_interrupt_state (SIGSEGV) != 's')
631 sigaction (SIGSEGV, &act, NULL);
632
633 __gnat_handler_installed = 1;
634 }
635
636 /*******************/
637 /* LynxOS Section */
638 /*******************/
639
640 #elif defined (__Lynx__)
641
642 #include <signal.h>
643 #include <unistd.h>
644
645 static void
646 __gnat_error_handler (int sig)
647 {
648 struct Exception_Data *exception;
649 const char *msg;
650
651 switch(sig)
652 {
653 case SIGFPE:
654 exception = &constraint_error;
655 msg = "SIGFPE";
656 break;
657 case SIGILL:
658 exception = &constraint_error;
659 msg = "SIGILL";
660 break;
661 case SIGSEGV:
662 exception = &storage_error;
663 msg = "stack overflow or erroneous memory access";
664 break;
665 case SIGBUS:
666 exception = &constraint_error;
667 msg = "SIGBUS";
668 break;
669 default:
670 exception = &program_error;
671 msg = "unhandled signal";
672 }
673
674 Raise_From_Signal_Handler(exception, msg);
675 }
676
677 void
678 __gnat_install_handler(void)
679 {
680 struct sigaction act;
681
682 act.sa_handler = __gnat_error_handler;
683 act.sa_flags = 0x0;
684 sigemptyset (&act.sa_mask);
685
686 /* Do not install handlers if interrupt state is "System". */
687 if (__gnat_get_interrupt_state (SIGFPE) != 's')
688 sigaction (SIGFPE, &act, NULL);
689 if (__gnat_get_interrupt_state (SIGILL) != 's')
690 sigaction (SIGILL, &act, NULL);
691 if (__gnat_get_interrupt_state (SIGSEGV) != 's')
692 sigaction (SIGSEGV, &act, NULL);
693 if (__gnat_get_interrupt_state (SIGBUS) != 's')
694 sigaction (SIGBUS, &act, NULL);
695
696 __gnat_handler_installed = 1;
697 }
698
699 /*******************/
700 /* Solaris Section */
701 /*******************/
702
703 #elif defined (sun) && defined (__SVR4) && !defined (__vxworks)
704
705 #include <signal.h>
706 #include <siginfo.h>
707 #include <sys/ucontext.h>
708 #include <sys/regset.h>
709
710 /* The code below is common to SPARC and x86. Beware of the delay slot
711 differences for signal context adjustments. */
712
713 #if defined (__sparc)
714 #define RETURN_ADDR_OFFSET 8
715 #else
716 #define RETURN_ADDR_OFFSET 0
717 #endif
718
719 static void
720 __gnat_error_handler (int sig, siginfo_t *si, void *ucontext ATTRIBUTE_UNUSED)
721 {
722 struct Exception_Data *exception;
723 static int recurse = 0;
724 const char *msg;
725
726 switch (sig)
727 {
728 case SIGSEGV:
729 /* If the problem was permissions, this is a constraint error.
730 Likewise if the failing address isn't maximally aligned or if
731 we've recursed.
732
733 ??? Using a static variable here isn't task-safe, but it's
734 much too hard to do anything else and we're just determining
735 which exception to raise. */
736 if (si->si_code == SEGV_ACCERR
737 || (long) si->si_addr == 0
738 || (((long) si->si_addr) & 3) != 0
739 || recurse)
740 {
741 exception = &constraint_error;
742 msg = "SIGSEGV";
743 }
744 else
745 {
746 /* See if the page before the faulting page is accessible. Do that
747 by trying to access it. We'd like to simply try to access
748 4096 + the faulting address, but it's not guaranteed to be
749 the actual address, just to be on the same page. */
750 recurse++;
751 ((volatile char *)
752 ((long) si->si_addr & - getpagesize ()))[getpagesize ()];
753 exception = &storage_error;
754 msg = "stack overflow or erroneous memory access";
755 }
756 break;
757
758 case SIGBUS:
759 exception = &program_error;
760 msg = "SIGBUS";
761 break;
762
763 case SIGFPE:
764 exception = &constraint_error;
765 msg = "SIGFPE";
766 break;
767
768 default:
769 exception = &program_error;
770 msg = "unhandled signal";
771 }
772
773 recurse = 0;
774 Raise_From_Signal_Handler (exception, msg);
775 }
776
777 void
778 __gnat_install_handler (void)
779 {
780 struct sigaction act;
781
782 /* Set up signal handler to map synchronous signals to appropriate
783 exceptions. Make sure that the handler isn't interrupted by another
784 signal that might cause a scheduling event! */
785
786 act.sa_sigaction = __gnat_error_handler;
787 act.sa_flags = SA_NODEFER | SA_RESTART | SA_SIGINFO;
788 sigemptyset (&act.sa_mask);
789
790 /* Do not install handlers if interrupt state is "System". */
791 if (__gnat_get_interrupt_state (SIGABRT) != 's')
792 sigaction (SIGABRT, &act, NULL);
793 if (__gnat_get_interrupt_state (SIGFPE) != 's')
794 sigaction (SIGFPE, &act, NULL);
795 if (__gnat_get_interrupt_state (SIGSEGV) != 's')
796 sigaction (SIGSEGV, &act, NULL);
797 if (__gnat_get_interrupt_state (SIGBUS) != 's')
798 sigaction (SIGBUS, &act, NULL);
799
800 __gnat_handler_installed = 1;
801 }
802
803 /***************/
804 /* VMS Section */
805 /***************/
806
807 #elif defined (VMS)
808
809 /* Routine called from binder to override default feature values. */
810 void __gnat_set_features (void);
811 int __gnat_features_set = 0;
812
813 #ifdef __IA64
814 #define lib_get_curr_invo_context LIB$I64_GET_CURR_INVO_CONTEXT
815 #define lib_get_prev_invo_context LIB$I64_GET_PREV_INVO_CONTEXT
816 #define lib_get_invo_handle LIB$I64_GET_INVO_HANDLE
817 #else
818 #define lib_get_curr_invo_context LIB$GET_CURR_INVO_CONTEXT
819 #define lib_get_prev_invo_context LIB$GET_PREV_INVO_CONTEXT
820 #define lib_get_invo_handle LIB$GET_INVO_HANDLE
821 #endif
822
823 /* Define macro symbols for the VMS conditions that become Ada exceptions.
824 Most of these are also defined in the header file ssdef.h which has not
825 yet been converted to be recognized by GNU C. */
826
827 /* Defining these as macros, as opposed to external addresses, allows
828 them to be used in a case statement below. */
829 #define SS$_ACCVIO 12
830 #define SS$_HPARITH 1284
831 #define SS$_STKOVF 1364
832 #define SS$_RESIGNAL 2328
833
834 /* These codes are in standard message libraries. */
835 extern int C$_SIGKILL;
836 extern int SS$_DEBUG;
837 extern int LIB$_KEYNOTFOU;
838 extern int LIB$_ACTIMAGE;
839 #define CMA$_EXIT_THREAD 4227492
840 #define MTH$_FLOOVEMAT 1475268 /* Some ACVC_21 CXA tests */
841 #define SS$_INTDIV 1156
842
843 /* These codes are non standard, which is to say the author is
844 not sure if they are defined in the standard message libraries
845 so keep them as macros for now. */
846 #define RDB$_STREAM_EOF 20480426
847 #define FDL$_UNPRIKW 11829410
848
849 struct cond_except {
850 unsigned int cond;
851 const struct Exception_Data *except;
852 };
853
854 struct descriptor_s {
855 unsigned short len, mbz;
856 __char_ptr32 adr;
857 };
858
859 /* Conditions that don't have an Ada exception counterpart must raise
860 Non_Ada_Error. Since this is defined in s-auxdec, it should only be
861 referenced by user programs, not the compiler or tools. Hence the
862 #ifdef IN_RTS. */
863
864 #ifdef IN_RTS
865
866 #define Status_Error ada__io_exceptions__status_error
867 extern struct Exception_Data Status_Error;
868
869 #define Mode_Error ada__io_exceptions__mode_error
870 extern struct Exception_Data Mode_Error;
871
872 #define Name_Error ada__io_exceptions__name_error
873 extern struct Exception_Data Name_Error;
874
875 #define Use_Error ada__io_exceptions__use_error
876 extern struct Exception_Data Use_Error;
877
878 #define Device_Error ada__io_exceptions__device_error
879 extern struct Exception_Data Device_Error;
880
881 #define End_Error ada__io_exceptions__end_error
882 extern struct Exception_Data End_Error;
883
884 #define Data_Error ada__io_exceptions__data_error
885 extern struct Exception_Data Data_Error;
886
887 #define Layout_Error ada__io_exceptions__layout_error
888 extern struct Exception_Data Layout_Error;
889
890 #define Non_Ada_Error system__aux_dec__non_ada_error
891 extern struct Exception_Data Non_Ada_Error;
892
893 #define Coded_Exception system__vms_exception_table__coded_exception
894 extern struct Exception_Data *Coded_Exception (Exception_Code);
895
896 #define Base_Code_In system__vms_exception_table__base_code_in
897 extern Exception_Code Base_Code_In (Exception_Code);
898
899 /* DEC Ada exceptions are not defined in a header file, so they
900 must be declared. */
901
902 #define ADA$_ALREADY_OPEN 0x0031a594
903 #define ADA$_CONSTRAINT_ERRO 0x00318324
904 #define ADA$_DATA_ERROR 0x003192c4
905 #define ADA$_DEVICE_ERROR 0x003195e4
906 #define ADA$_END_ERROR 0x00319904
907 #define ADA$_FAC_MODE_MISMAT 0x0031a8b3
908 #define ADA$_IOSYSFAILED 0x0031af04
909 #define ADA$_KEYSIZERR 0x0031aa3c
910 #define ADA$_KEY_MISMATCH 0x0031a8e3
911 #define ADA$_LAYOUT_ERROR 0x00319c24
912 #define ADA$_LINEXCMRS 0x0031a8f3
913 #define ADA$_MAXLINEXC 0x0031a8eb
914 #define ADA$_MODE_ERROR 0x00319f44
915 #define ADA$_MRN_MISMATCH 0x0031a8db
916 #define ADA$_MRS_MISMATCH 0x0031a8d3
917 #define ADA$_NAME_ERROR 0x0031a264
918 #define ADA$_NOT_OPEN 0x0031a58c
919 #define ADA$_ORG_MISMATCH 0x0031a8bb
920 #define ADA$_PROGRAM_ERROR 0x00318964
921 #define ADA$_RAT_MISMATCH 0x0031a8cb
922 #define ADA$_RFM_MISMATCH 0x0031a8c3
923 #define ADA$_STAOVF 0x00318cac
924 #define ADA$_STATUS_ERROR 0x0031a584
925 #define ADA$_STORAGE_ERROR 0x00318c84
926 #define ADA$_UNSUPPORTED 0x0031a8ab
927 #define ADA$_USE_ERROR 0x0031a8a4
928
929 /* DEC Ada specific conditions. */
930 static const struct cond_except dec_ada_cond_except_table [] = {
931 {ADA$_PROGRAM_ERROR, &program_error},
932 {ADA$_USE_ERROR, &Use_Error},
933 {ADA$_KEYSIZERR, &program_error},
934 {ADA$_STAOVF, &storage_error},
935 {ADA$_CONSTRAINT_ERRO, &constraint_error},
936 {ADA$_IOSYSFAILED, &Device_Error},
937 {ADA$_LAYOUT_ERROR, &Layout_Error},
938 {ADA$_STORAGE_ERROR, &storage_error},
939 {ADA$_DATA_ERROR, &Data_Error},
940 {ADA$_DEVICE_ERROR, &Device_Error},
941 {ADA$_END_ERROR, &End_Error},
942 {ADA$_MODE_ERROR, &Mode_Error},
943 {ADA$_NAME_ERROR, &Name_Error},
944 {ADA$_STATUS_ERROR, &Status_Error},
945 {ADA$_NOT_OPEN, &Use_Error},
946 {ADA$_ALREADY_OPEN, &Use_Error},
947 {ADA$_USE_ERROR, &Use_Error},
948 {ADA$_UNSUPPORTED, &Use_Error},
949 {ADA$_FAC_MODE_MISMAT, &Use_Error},
950 {ADA$_ORG_MISMATCH, &Use_Error},
951 {ADA$_RFM_MISMATCH, &Use_Error},
952 {ADA$_RAT_MISMATCH, &Use_Error},
953 {ADA$_MRS_MISMATCH, &Use_Error},
954 {ADA$_MRN_MISMATCH, &Use_Error},
955 {ADA$_KEY_MISMATCH, &Use_Error},
956 {ADA$_MAXLINEXC, &constraint_error},
957 {ADA$_LINEXCMRS, &constraint_error},
958
959 #if 0
960 /* Already handled by a pragma Import_Exception
961 in Aux_IO_Exceptions */
962 {ADA$_LOCK_ERROR, &Lock_Error},
963 {ADA$_EXISTENCE_ERROR, &Existence_Error},
964 {ADA$_KEY_ERROR, &Key_Error},
965 #endif
966
967 {0, 0}
968 };
969
970 #endif /* IN_RTS */
971
972 /* Non-DEC Ada specific conditions. We could probably also put
973 SS$_HPARITH here and possibly SS$_ACCVIO, SS$_STKOVF. */
974 static const struct cond_except cond_except_table [] = {
975 {MTH$_FLOOVEMAT, &constraint_error},
976 {SS$_INTDIV, &constraint_error},
977 {0, 0}
978 };
979
980 /* To deal with VMS conditions and their mapping to Ada exceptions,
981 the __gnat_error_handler routine below is installed as an exception
982 vector having precedence over DEC frame handlers. Some conditions
983 still need to be handled by such handlers, however, in which case
984 __gnat_error_handler needs to return SS$_RESIGNAL. Consider for
985 instance the use of a third party library compiled with DECAda and
986 performing its own exception handling internally.
987
988 To allow some user-level flexibility, which conditions should be
989 resignaled is controlled by a predicate function, provided with the
990 condition value and returning a boolean indication stating whether
991 this condition should be resignaled or not.
992
993 That predicate function is called indirectly, via a function pointer,
994 by __gnat_error_handler, and changing that pointer is allowed to the
995 user code by way of the __gnat_set_resignal_predicate interface.
996
997 The user level function may then implement what it likes, including
998 for instance the maintenance of a dynamic data structure if the set
999 of to be resignalled conditions has to change over the program's
1000 lifetime.
1001
1002 ??? This is not a perfect solution to deal with the possible
1003 interactions between the GNAT and the DECAda exception handling
1004 models and better (more general) schemes are studied. This is so
1005 just provided as a convenient workaround in the meantime, and
1006 should be use with caution since the implementation has been kept
1007 very simple. */
1008
1009 typedef int
1010 resignal_predicate (int code);
1011
1012 static const int * const cond_resignal_table [] = {
1013 &C$_SIGKILL,
1014 (int *)CMA$_EXIT_THREAD,
1015 &SS$_DEBUG,
1016 &LIB$_KEYNOTFOU,
1017 &LIB$_ACTIMAGE,
1018 (int *) RDB$_STREAM_EOF,
1019 (int *) FDL$_UNPRIKW,
1020 0
1021 };
1022
1023 static const int facility_resignal_table [] = {
1024 0x1380000, /* RDB */
1025 0x2220000, /* SQL */
1026 0
1027 };
1028
1029 /* Default GNAT predicate for resignaling conditions. */
1030
1031 static int
1032 __gnat_default_resignal_p (int code)
1033 {
1034 int i, iexcept;
1035
1036 for (i = 0; facility_resignal_table [i]; i++)
1037 if ((code & 0xfff0000) == facility_resignal_table [i])
1038 return 1;
1039
1040 for (i = 0, iexcept = 0;
1041 cond_resignal_table [i]
1042 && !(iexcept = LIB$MATCH_COND (&code, &cond_resignal_table [i]));
1043 i++);
1044
1045 return iexcept;
1046 }
1047
1048 /* Static pointer to predicate that the __gnat_error_handler exception
1049 vector invokes to determine if it should resignal a condition. */
1050
1051 static resignal_predicate *__gnat_resignal_p = __gnat_default_resignal_p;
1052
1053 /* User interface to change the predicate pointer to PREDICATE. Reset to
1054 the default if PREDICATE is null. */
1055
1056 void
1057 __gnat_set_resignal_predicate (resignal_predicate *predicate)
1058 {
1059 if (predicate == NULL)
1060 __gnat_resignal_p = __gnat_default_resignal_p;
1061 else
1062 __gnat_resignal_p = predicate;
1063 }
1064
1065 /* Should match System.Parameters.Default_Exception_Msg_Max_Length. */
1066 #define Default_Exception_Msg_Max_Length 512
1067
1068 /* Action routine for SYS$PUTMSG. There may be multiple
1069 conditions, each with text to be appended to MESSAGE
1070 and separated by line termination. */
1071
1072 static int
1073 copy_msg (struct descriptor_s *msgdesc, char *message)
1074 {
1075 int len = strlen (message);
1076 int copy_len;
1077
1078 /* Check for buffer overflow and skip. */
1079 if (len > 0 && len <= Default_Exception_Msg_Max_Length - 3)
1080 {
1081 strcat (message, "\r\n");
1082 len += 2;
1083 }
1084
1085 /* Check for buffer overflow and truncate if necessary. */
1086 copy_len = (len + msgdesc->len <= Default_Exception_Msg_Max_Length - 1 ?
1087 msgdesc->len :
1088 Default_Exception_Msg_Max_Length - 1 - len);
1089 strncpy (&message [len], msgdesc->adr, copy_len);
1090 message [len + copy_len] = 0;
1091
1092 return 0;
1093 }
1094
1095 long
1096 __gnat_handle_vms_condition (int *sigargs, void *mechargs)
1097 {
1098 struct Exception_Data *exception = 0;
1099 Exception_Code base_code;
1100 struct descriptor_s gnat_facility = {4, 0, "GNAT"};
1101 char message [Default_Exception_Msg_Max_Length];
1102
1103 const char *msg = "";
1104
1105 /* Check for conditions to resignal which aren't effected by pragma
1106 Import_Exception. */
1107 if (__gnat_resignal_p (sigargs [1]))
1108 return SS$_RESIGNAL;
1109
1110 #ifdef IN_RTS
1111 /* See if it's an imported exception. Beware that registered exceptions
1112 are bound to their base code, with the severity bits masked off. */
1113 base_code = Base_Code_In ((Exception_Code) sigargs[1]);
1114 exception = Coded_Exception (base_code);
1115
1116 if (exception)
1117 {
1118 message[0] = 0;
1119
1120 /* Subtract PC & PSL fields which messes with PUTMSG. */
1121 sigargs[0] -= 2;
1122 SYS$PUTMSG (sigargs, copy_msg, &gnat_facility, message);
1123 sigargs[0] += 2;
1124 msg = message;
1125
1126 exception->Name_Length = 19;
1127 /* ??? The full name really should be get SYS$GETMSG returns. */
1128 exception->Full_Name = "IMPORTED_EXCEPTION";
1129 exception->Import_Code = base_code;
1130
1131 #ifdef __IA64
1132 /* Do not adjust the program counter as already points to the next
1133 instruction (just after the call to LIB$STOP). */
1134 Raise_From_Signal_Handler (exception, msg);
1135 #endif
1136 }
1137 #endif
1138
1139 if (exception == 0)
1140 switch (sigargs[1])
1141 {
1142 case SS$_ACCVIO:
1143 if (sigargs[3] == 0)
1144 {
1145 exception = &constraint_error;
1146 msg = "access zero";
1147 }
1148 else
1149 {
1150 exception = &storage_error;
1151 msg = "stack overflow or erroneous memory access";
1152 }
1153 __gnat_adjust_context_for_raise (SS$_ACCVIO, (void *)mechargs);
1154 break;
1155
1156 case SS$_STKOVF:
1157 exception = &storage_error;
1158 msg = "stack overflow";
1159 __gnat_adjust_context_for_raise (SS$_STKOVF, (void *)mechargs);
1160 break;
1161
1162 case SS$_HPARITH:
1163 #ifndef IN_RTS
1164 return SS$_RESIGNAL; /* toplev.c handles for compiler */
1165 #else
1166 exception = &constraint_error;
1167 msg = "arithmetic error";
1168 __gnat_adjust_context_for_raise (SS$_HPARITH, (void *)mechargs);
1169 #endif
1170 break;
1171
1172 default:
1173 #ifdef IN_RTS
1174 {
1175 int i;
1176
1177 /* Scan the DEC Ada exception condition table for a match and fetch
1178 the associated GNAT exception pointer. */
1179 for (i = 0;
1180 dec_ada_cond_except_table [i].cond &&
1181 !LIB$MATCH_COND (&sigargs [1],
1182 &dec_ada_cond_except_table [i].cond);
1183 i++);
1184 exception = (struct Exception_Data *)
1185 dec_ada_cond_except_table [i].except;
1186
1187 if (!exception)
1188 {
1189 /* Scan the VMS standard condition table for a match and fetch
1190 the associated GNAT exception pointer. */
1191 for (i = 0;
1192 cond_except_table[i].cond &&
1193 !LIB$MATCH_COND (&sigargs[1], &cond_except_table[i].cond);
1194 i++);
1195 exception = (struct Exception_Data *)
1196 cond_except_table [i].except;
1197
1198 if (!exception)
1199 /* User programs expect Non_Ada_Error to be raised, reference
1200 DEC Ada test CXCONDHAN. */
1201 exception = &Non_Ada_Error;
1202 }
1203 }
1204 #else
1205 exception = &program_error;
1206 #endif
1207 message[0] = 0;
1208 /* Subtract PC & PSL fields which messes with PUTMSG. */
1209 sigargs[0] -= 2;
1210 SYS$PUTMSG (sigargs, copy_msg, &gnat_facility, message);
1211 sigargs[0] += 2;
1212 msg = message;
1213 break;
1214 }
1215
1216 Raise_From_Signal_Handler (exception, msg);
1217 }
1218
1219 void
1220 __gnat_install_handler (void)
1221 {
1222 long prvhnd ATTRIBUTE_UNUSED;
1223
1224 #if !defined (IN_RTS)
1225 SYS$SETEXV (1, __gnat_handle_vms_condition, 3, &prvhnd);
1226 #endif
1227
1228 __gnat_handler_installed = 1;
1229 }
1230
1231 /* __gnat_adjust_context_for_raise for Alpha - see comments along with the
1232 default version later in this file. */
1233
1234 #if defined (IN_RTS) && defined (__alpha__)
1235
1236 #include <vms/chfctxdef.h>
1237 #include <vms/chfdef.h>
1238
1239 #define HAVE_GNAT_ADJUST_CONTEXT_FOR_RAISE
1240
1241 void
1242 __gnat_adjust_context_for_raise (int signo ATTRIBUTE_UNUSED, void *ucontext)
1243 {
1244 if (signo == SS$_HPARITH)
1245 {
1246 /* Sub one to the address of the instruction signaling the condition,
1247 located in the sigargs array. */
1248
1249 CHF$MECH_ARRAY * mechargs = (CHF$MECH_ARRAY *) ucontext;
1250 CHF$SIGNAL_ARRAY * sigargs
1251 = (CHF$SIGNAL_ARRAY *) mechargs->chf$q_mch_sig_addr;
1252
1253 int vcount = sigargs->chf$is_sig_args;
1254 int * pc_slot = & (&sigargs->chf$l_sig_name)[vcount-2];
1255
1256 (*pc_slot)--;
1257 }
1258 }
1259
1260 #endif
1261
1262 /* __gnat_adjust_context_for_raise for ia64. */
1263
1264 #if defined (IN_RTS) && defined (__IA64)
1265
1266 #include <vms/chfctxdef.h>
1267 #include <vms/chfdef.h>
1268
1269 #define HAVE_GNAT_ADJUST_CONTEXT_FOR_RAISE
1270
1271 typedef unsigned long long u64;
1272
1273 void
1274 __gnat_adjust_context_for_raise (int signo ATTRIBUTE_UNUSED, void *ucontext)
1275 {
1276 /* Add one to the address of the instruction signaling the condition,
1277 located in the 64bits sigargs array. */
1278
1279 CHF$MECH_ARRAY * mechargs = (CHF$MECH_ARRAY *) ucontext;
1280
1281 CHF64$SIGNAL_ARRAY *chfsig64
1282 = (CHF64$SIGNAL_ARRAY *) mechargs->chf$ph_mch_sig64_addr;
1283
1284 u64 * post_sigarray
1285 = (u64 *)chfsig64 + 1 + chfsig64->chf64$l_sig_args;
1286
1287 u64 * ih_pc_loc = post_sigarray - 2;
1288
1289 (*ih_pc_loc) ++;
1290 }
1291
1292 #endif
1293
1294 /* Easier interface for LIB$GET_LOGICAL: put the equivalence of NAME into BUF,
1295 always NUL terminated. In case of error or if the result is longer than
1296 LEN (length of BUF) an empty string is written info BUF. */
1297
1298 static void
1299 __gnat_vms_get_logical (const char *name, char *buf, int len)
1300 {
1301 struct descriptor_s name_desc, result_desc;
1302 int status;
1303 unsigned short rlen;
1304
1305 /* Build the descriptor for NAME. */
1306 name_desc.len = strlen (name);
1307 name_desc.mbz = 0;
1308 name_desc.adr = (char *)name;
1309
1310 /* Build the descriptor for the result. */
1311 result_desc.len = len;
1312 result_desc.mbz = 0;
1313 result_desc.adr = buf;
1314
1315 status = LIB$GET_LOGICAL (&name_desc, &result_desc, &rlen);
1316
1317 if ((status & 1) == 1 && rlen < len)
1318 buf[rlen] = 0;
1319 else
1320 buf[0] = 0;
1321 }
1322
1323 /* Size of a page on ia64 and alpha VMS. */
1324 #define VMS_PAGESIZE 8192
1325
1326 /* User mode. */
1327 #define PSL__C_USER 3
1328
1329 /* No access. */
1330 #define PRT__C_NA 0
1331
1332 /* Descending region. */
1333 #define VA__M_DESCEND 1
1334
1335 /* Get by virtual address. */
1336 #define VA___REGSUM_BY_VA 1
1337
1338 /* Memory region summary. */
1339 struct regsum
1340 {
1341 unsigned long long q_region_id;
1342 unsigned int l_flags;
1343 unsigned int l_region_protection;
1344 void *pq_start_va;
1345 unsigned long long q_region_size;
1346 void *pq_first_free_va;
1347 };
1348
1349 extern int SYS$GET_REGION_INFO (unsigned int, unsigned long long *,
1350 void *, void *, unsigned int,
1351 void *, unsigned int *);
1352 extern int SYS$EXPREG_64 (unsigned long long *, unsigned long long,
1353 unsigned int, unsigned int, void **,
1354 unsigned long long *);
1355 extern int SYS$SETPRT_64 (void *, unsigned long long, unsigned int,
1356 unsigned int, void **, unsigned long long *,
1357 unsigned int *);
1358 extern int SYS$PUTMSG (void *, int (*)(), void *, unsigned long long);
1359
1360 /* Add a guard page in the memory region containing ADDR at ADDR +/- SIZE.
1361 (The sign depends on the kind of the memory region). */
1362
1363 static int
1364 __gnat_set_stack_guard_page (void *addr, unsigned long size)
1365 {
1366 int status;
1367 void *ret_va;
1368 unsigned long long ret_len;
1369 unsigned int ret_prot;
1370 void *start_va;
1371 unsigned long long length;
1372 unsigned int retlen;
1373 struct regsum buffer;
1374
1375 /* Get the region for ADDR. */
1376 status = SYS$GET_REGION_INFO
1377 (VA___REGSUM_BY_VA, NULL, addr, NULL, sizeof (buffer), &buffer, &retlen);
1378
1379 if ((status & 1) != 1)
1380 return -1;
1381
1382 /* Extend the region. */
1383 status = SYS$EXPREG_64 (&buffer.q_region_id,
1384 size, 0, 0, &start_va, &length);
1385
1386 if ((status & 1) != 1)
1387 return -1;
1388
1389 /* Create a guard page. */
1390 if (!(buffer.l_flags & VA__M_DESCEND))
1391 start_va = (void *)((unsigned long long)start_va + length - VMS_PAGESIZE);
1392
1393 status = SYS$SETPRT_64 (start_va, VMS_PAGESIZE, PSL__C_USER, PRT__C_NA,
1394 &ret_va, &ret_len, &ret_prot);
1395
1396 if ((status & 1) != 1)
1397 return -1;
1398 return 0;
1399 }
1400
1401 /* Read logicals to limit the stack(s) size. */
1402
1403 static void
1404 __gnat_set_stack_limit (void)
1405 {
1406 #ifdef __ia64__
1407 void *sp;
1408 unsigned long size;
1409 char value[16];
1410 char *e;
1411
1412 /* The main stack. */
1413 __gnat_vms_get_logical ("GNAT_STACK_SIZE", value, sizeof (value));
1414 size = strtoul (value, &e, 0);
1415 if (e > value && *e == 0)
1416 {
1417 asm ("mov %0=sp" : "=r" (sp));
1418 __gnat_set_stack_guard_page (sp, size * 1024);
1419 }
1420
1421 /* The register stack. */
1422 __gnat_vms_get_logical ("GNAT_RBS_SIZE", value, sizeof (value));
1423 size = strtoul (value, &e, 0);
1424 if (e > value && *e == 0)
1425 {
1426 asm ("mov %0=ar.bsp" : "=r" (sp));
1427 __gnat_set_stack_guard_page (sp, size * 1024);
1428 }
1429 #endif
1430 }
1431
1432 /* Feature logical name and global variable address pair.
1433 If we ever add another feature logical to this list, the
1434 feature struct will need to be enhanced to take into account
1435 possible values for *gl_addr. */
1436 struct feature {
1437 const char *name;
1438 int *gl_addr;
1439 };
1440
1441 /* Default values for GNAT features set by environment. */
1442 int __gl_heap_size = 64;
1443
1444 /* Array feature logical names and global variable addresses. */
1445 static const struct feature features[] = {
1446 {"GNAT$NO_MALLOC_64", &__gl_heap_size},
1447 {0, 0}
1448 };
1449
1450 void
1451 __gnat_set_features (void)
1452 {
1453 int i;
1454 char buff[16];
1455
1456 /* Loop through features array and test name for enable/disable. */
1457 for (i = 0; features[i].name; i++)
1458 {
1459 __gnat_vms_get_logical (features[i].name, buff, sizeof (buff));
1460
1461 if (strcmp (buff, "ENABLE") == 0
1462 || strcmp (buff, "TRUE") == 0
1463 || strcmp (buff, "1") == 0)
1464 *features[i].gl_addr = 32;
1465 else if (strcmp (buff, "DISABLE") == 0
1466 || strcmp (buff, "FALSE") == 0
1467 || strcmp (buff, "0") == 0)
1468 *features[i].gl_addr = 64;
1469 }
1470
1471 /* Features to artificially limit the stack size. */
1472 __gnat_set_stack_limit ();
1473
1474 __gnat_features_set = 1;
1475 }
1476
1477 /* Return true if the VMS version is 7.x. */
1478
1479 extern unsigned int LIB$GETSYI (int *, ...);
1480
1481 #define SYI$_VERSION 0x1000
1482
1483 int
1484 __gnat_is_vms_v7 (void)
1485 {
1486 struct descriptor_s desc;
1487 char version[8];
1488 int status;
1489 int code = SYI$_VERSION;
1490
1491 desc.len = sizeof (version);
1492 desc.mbz = 0;
1493 desc.adr = version;
1494
1495 status = LIB$GETSYI (&code, 0, &desc);
1496 if ((status & 1) == 1 && version[1] == '7' && version[2] == '.')
1497 return 1;
1498 else
1499 return 0;
1500 }
1501
1502 /*******************/
1503 /* FreeBSD Section */
1504 /*******************/
1505
1506 #elif defined (__FreeBSD__)
1507
1508 #include <signal.h>
1509 #include <sys/ucontext.h>
1510 #include <unistd.h>
1511
1512 static void
1513 __gnat_error_handler (int sig,
1514 siginfo_t *si ATTRIBUTE_UNUSED,
1515 void *ucontext ATTRIBUTE_UNUSED)
1516 {
1517 struct Exception_Data *exception;
1518 const char *msg;
1519
1520 switch (sig)
1521 {
1522 case SIGFPE:
1523 exception = &constraint_error;
1524 msg = "SIGFPE";
1525 break;
1526
1527 case SIGILL:
1528 exception = &constraint_error;
1529 msg = "SIGILL";
1530 break;
1531
1532 case SIGSEGV:
1533 exception = &storage_error;
1534 msg = "stack overflow or erroneous memory access";
1535 break;
1536
1537 case SIGBUS:
1538 exception = &storage_error;
1539 msg = "SIGBUS: possible stack overflow";
1540 break;
1541
1542 default:
1543 exception = &program_error;
1544 msg = "unhandled signal";
1545 }
1546
1547 Raise_From_Signal_Handler (exception, msg);
1548 }
1549
1550 void
1551 __gnat_install_handler ()
1552 {
1553 struct sigaction act;
1554
1555 /* Set up signal handler to map synchronous signals to appropriate
1556 exceptions. Make sure that the handler isn't interrupted by another
1557 signal that might cause a scheduling event! */
1558
1559 act.sa_sigaction
1560 = (void (*)(int, struct __siginfo *, void*)) __gnat_error_handler;
1561 act.sa_flags = SA_NODEFER | SA_RESTART | SA_SIGINFO;
1562 (void) sigemptyset (&act.sa_mask);
1563
1564 (void) sigaction (SIGILL, &act, NULL);
1565 (void) sigaction (SIGFPE, &act, NULL);
1566 (void) sigaction (SIGSEGV, &act, NULL);
1567 (void) sigaction (SIGBUS, &act, NULL);
1568
1569 __gnat_handler_installed = 1;
1570 }
1571
1572 /*******************/
1573 /* VxWorks Section */
1574 /*******************/
1575
1576 #elif defined(__vxworks)
1577
1578 #include <signal.h>
1579 #include <taskLib.h>
1580
1581 #ifndef __RTP__
1582 #include <intLib.h>
1583 #include <iv.h>
1584 #endif
1585
1586 #ifdef VTHREADS
1587 #include "private/vThreadsP.h"
1588 #endif
1589
1590 void __gnat_error_handler (int, void *, struct sigcontext *);
1591
1592 #ifndef __RTP__
1593
1594 /* Directly vectored Interrupt routines are not supported when using RTPs. */
1595
1596 extern int __gnat_inum_to_ivec (int);
1597
1598 /* This is needed by the GNAT run time to handle Vxworks interrupts. */
1599 int
1600 __gnat_inum_to_ivec (int num)
1601 {
1602 return INUM_TO_IVEC (num);
1603 }
1604 #endif
1605
1606 #if !defined(__alpha_vxworks) && (_WRS_VXWORKS_MAJOR != 6) && !defined(__RTP__)
1607
1608 /* getpid is used by s-parint.adb, but is not defined by VxWorks, except
1609 on Alpha VxWorks and VxWorks 6.x (including RTPs). */
1610
1611 extern long getpid (void);
1612
1613 long
1614 getpid (void)
1615 {
1616 return taskIdSelf ();
1617 }
1618 #endif
1619
1620 /* VxWorks 653 vThreads expects the field excCnt to be zeroed when a signal is.
1621 handled. The VxWorks version of longjmp does this; GCC's builtin_longjmp
1622 doesn't. */
1623 void
1624 __gnat_clear_exception_count (void)
1625 {
1626 #ifdef VTHREADS
1627 WIND_TCB *currentTask = (WIND_TCB *) taskIdSelf();
1628
1629 currentTask->vThreads.excCnt = 0;
1630 #endif
1631 }
1632
1633 /* Handle different SIGnal to exception mappings in different VxWorks
1634 versions. */
1635 static void
1636 __gnat_map_signal (int sig, void *si ATTRIBUTE_UNUSED,
1637 struct sigcontext *sc ATTRIBUTE_UNUSED)
1638 {
1639 struct Exception_Data *exception;
1640 const char *msg;
1641
1642 switch (sig)
1643 {
1644 case SIGFPE:
1645 exception = &constraint_error;
1646 msg = "SIGFPE";
1647 break;
1648 #ifdef VTHREADS
1649 #ifdef __VXWORKSMILS__
1650 case SIGILL:
1651 exception = &storage_error;
1652 msg = "SIGILL: possible stack overflow";
1653 break;
1654 case SIGSEGV:
1655 exception = &storage_error;
1656 msg = "SIGSEGV";
1657 break;
1658 case SIGBUS:
1659 exception = &program_error;
1660 msg = "SIGBUS";
1661 break;
1662 #else
1663 case SIGILL:
1664 exception = &constraint_error;
1665 msg = "Floating point exception or SIGILL";
1666 break;
1667 case SIGSEGV:
1668 exception = &storage_error;
1669 msg = "SIGSEGV";
1670 break;
1671 case SIGBUS:
1672 exception = &storage_error;
1673 msg = "SIGBUS: possible stack overflow";
1674 break;
1675 #endif
1676 #elif (_WRS_VXWORKS_MAJOR == 6)
1677 case SIGILL:
1678 exception = &constraint_error;
1679 msg = "SIGILL";
1680 break;
1681 #ifdef __RTP__
1682 /* In RTP mode a SIGSEGV is most likely due to a stack overflow,
1683 since stack checking uses the probing mechanism. */
1684 case SIGSEGV:
1685 exception = &storage_error;
1686 msg = "SIGSEGV: possible stack overflow";
1687 break;
1688 case SIGBUS:
1689 exception = &program_error;
1690 msg = "SIGBUS";
1691 break;
1692 #else
1693 /* VxWorks 6 kernel mode with probing. SIGBUS for guard page hit */
1694 case SIGSEGV:
1695 exception = &storage_error;
1696 msg = "SIGSEGV";
1697 break;
1698 case SIGBUS:
1699 exception = &storage_error;
1700 msg = "SIGBUS: possible stack overflow";
1701 break;
1702 #endif
1703 #else
1704 /* VxWorks 5: a SIGILL is most likely due to a stack overflow,
1705 since stack checking uses the stack limit mechanism. */
1706 case SIGILL:
1707 exception = &storage_error;
1708 msg = "SIGILL: possible stack overflow";
1709 break;
1710 case SIGSEGV:
1711 exception = &storage_error;
1712 msg = "SIGSEGV";
1713 break;
1714 case SIGBUS:
1715 exception = &program_error;
1716 msg = "SIGBUS";
1717 break;
1718 #endif
1719 default:
1720 exception = &program_error;
1721 msg = "unhandled signal";
1722 }
1723
1724 __gnat_clear_exception_count ();
1725 Raise_From_Signal_Handler (exception, msg);
1726 }
1727
1728 /* Tasking and Non-tasking signal handler. Map SIGnal to Ada exception
1729 propagation after the required low level adjustments. */
1730
1731 void
1732 __gnat_error_handler (int sig, void *si, struct sigcontext *sc)
1733 {
1734 sigset_t mask;
1735
1736 /* VxWorks will always mask out the signal during the signal handler and
1737 will reenable it on a longjmp. GNAT does not generate a longjmp to
1738 return from a signal handler so the signal will still be masked unless
1739 we unmask it. */
1740 sigprocmask (SIG_SETMASK, NULL, &mask);
1741 sigdelset (&mask, sig);
1742 sigprocmask (SIG_SETMASK, &mask, NULL);
1743
1744 #if defined (__PPC__) && defined(_WRS_KERNEL)
1745 /* On PowerPC, kernel mode, we process signals through a Call Frame Info
1746 trampoline, voiding the need for myriads of fallback_frame_state
1747 variants in the ZCX runtime. We have no simple way to distinguish ZCX
1748 from SJLJ here, so we do this for SJLJ as well even though this is not
1749 necessary. This only incurs a few extra instructions and a tiny
1750 amount of extra stack usage. */
1751
1752 #include "sigtramp.h"
1753
1754 __gnat_sigtramp (sig, (void *)si, (void *)sc,
1755 (sighandler_t *)&__gnat_map_signal);
1756
1757 #else
1758 __gnat_map_signal (sig, si, sc);
1759 #endif
1760 }
1761
1762 void
1763 __gnat_install_handler (void)
1764 {
1765 struct sigaction act;
1766
1767 /* Setup signal handler to map synchronous signals to appropriate
1768 exceptions. Make sure that the handler isn't interrupted by another
1769 signal that might cause a scheduling event! */
1770
1771 act.sa_handler = __gnat_error_handler;
1772 act.sa_flags = SA_SIGINFO | SA_ONSTACK;
1773 sigemptyset (&act.sa_mask);
1774
1775 /* For VxWorks, install all signal handlers, since pragma Interrupt_State
1776 applies to vectored hardware interrupts, not signals. */
1777 sigaction (SIGFPE, &act, NULL);
1778 sigaction (SIGILL, &act, NULL);
1779 sigaction (SIGSEGV, &act, NULL);
1780 sigaction (SIGBUS, &act, NULL);
1781
1782 __gnat_handler_installed = 1;
1783 }
1784
1785 #define HAVE_GNAT_INIT_FLOAT
1786
1787 void
1788 __gnat_init_float (void)
1789 {
1790 /* Disable overflow/underflow exceptions on the PPC processor, needed
1791 to get correct Ada semantics. Note that for AE653 vThreads, the HW
1792 overflow settings are an OS configuration issue. The instructions
1793 below have no effect. */
1794 #if defined (_ARCH_PPC) && !defined (_SOFT_FLOAT) && (!defined (VTHREADS) || defined (__VXWORKSMILS__))
1795 #if defined (__SPE__)
1796 {
1797 const unsigned long spefscr_mask = 0xfffffff3;
1798 unsigned long spefscr;
1799 asm ("mfspr %0, 512" : "=r" (spefscr));
1800 spefscr = spefscr & spefscr_mask;
1801 asm ("mtspr 512, %0\n\tisync" : : "r" (spefscr));
1802 }
1803 #else
1804 asm ("mtfsb0 25");
1805 asm ("mtfsb0 26");
1806 #endif
1807 #endif
1808
1809 #if (defined (__i386__) || defined (i386)) && !defined (VTHREADS)
1810 /* This is used to properly initialize the FPU on an x86 for each
1811 process thread. */
1812 asm ("finit");
1813 #endif
1814
1815 /* Similarly for SPARC64. Achieved by masking bits in the Trap Enable Mask
1816 field of the Floating-point Status Register (see the SPARC Architecture
1817 Manual Version 9, p 48). */
1818 #if defined (sparc64)
1819
1820 #define FSR_TEM_NVM (1 << 27) /* Invalid operand */
1821 #define FSR_TEM_OFM (1 << 26) /* Overflow */
1822 #define FSR_TEM_UFM (1 << 25) /* Underflow */
1823 #define FSR_TEM_DZM (1 << 24) /* Division by Zero */
1824 #define FSR_TEM_NXM (1 << 23) /* Inexact result */
1825 {
1826 unsigned int fsr;
1827
1828 __asm__("st %%fsr, %0" : "=m" (fsr));
1829 fsr &= ~(FSR_TEM_OFM | FSR_TEM_UFM);
1830 __asm__("ld %0, %%fsr" : : "m" (fsr));
1831 }
1832 #endif
1833 }
1834
1835 /* This subprogram is called by System.Task_Primitives.Operations.Enter_Task
1836 (if not null) when a new task is created. It is initialized by
1837 System.Stack_Checking.Operations.Initialize_Stack_Limit.
1838 The use of a hook avoids to drag stack checking subprograms if stack
1839 checking is not used. */
1840 void (*__gnat_set_stack_limit_hook)(void) = (void (*)(void))0;
1841
1842 /******************/
1843 /* NetBSD Section */
1844 /******************/
1845
1846 #elif defined(__NetBSD__)
1847
1848 #include <signal.h>
1849 #include <unistd.h>
1850
1851 static void
1852 __gnat_error_handler (int sig)
1853 {
1854 struct Exception_Data *exception;
1855 const char *msg;
1856
1857 switch(sig)
1858 {
1859 case SIGFPE:
1860 exception = &constraint_error;
1861 msg = "SIGFPE";
1862 break;
1863 case SIGILL:
1864 exception = &constraint_error;
1865 msg = "SIGILL";
1866 break;
1867 case SIGSEGV:
1868 exception = &storage_error;
1869 msg = "stack overflow or erroneous memory access";
1870 break;
1871 case SIGBUS:
1872 exception = &constraint_error;
1873 msg = "SIGBUS";
1874 break;
1875 default:
1876 exception = &program_error;
1877 msg = "unhandled signal";
1878 }
1879
1880 Raise_From_Signal_Handler(exception, msg);
1881 }
1882
1883 void
1884 __gnat_install_handler(void)
1885 {
1886 struct sigaction act;
1887
1888 act.sa_handler = __gnat_error_handler;
1889 act.sa_flags = SA_NODEFER | SA_RESTART;
1890 sigemptyset (&act.sa_mask);
1891
1892 /* Do not install handlers if interrupt state is "System". */
1893 if (__gnat_get_interrupt_state (SIGFPE) != 's')
1894 sigaction (SIGFPE, &act, NULL);
1895 if (__gnat_get_interrupt_state (SIGILL) != 's')
1896 sigaction (SIGILL, &act, NULL);
1897 if (__gnat_get_interrupt_state (SIGSEGV) != 's')
1898 sigaction (SIGSEGV, &act, NULL);
1899 if (__gnat_get_interrupt_state (SIGBUS) != 's')
1900 sigaction (SIGBUS, &act, NULL);
1901
1902 __gnat_handler_installed = 1;
1903 }
1904
1905 /*******************/
1906 /* OpenBSD Section */
1907 /*******************/
1908
1909 #elif defined(__OpenBSD__)
1910
1911 #include <signal.h>
1912 #include <unistd.h>
1913
1914 static void
1915 __gnat_error_handler (int sig)
1916 {
1917 struct Exception_Data *exception;
1918 const char *msg;
1919
1920 switch(sig)
1921 {
1922 case SIGFPE:
1923 exception = &constraint_error;
1924 msg = "SIGFPE";
1925 break;
1926 case SIGILL:
1927 exception = &constraint_error;
1928 msg = "SIGILL";
1929 break;
1930 case SIGSEGV:
1931 exception = &storage_error;
1932 msg = "stack overflow or erroneous memory access";
1933 break;
1934 case SIGBUS:
1935 exception = &constraint_error;
1936 msg = "SIGBUS";
1937 break;
1938 default:
1939 exception = &program_error;
1940 msg = "unhandled signal";
1941 }
1942
1943 Raise_From_Signal_Handler(exception, msg);
1944 }
1945
1946 void
1947 __gnat_install_handler(void)
1948 {
1949 struct sigaction act;
1950
1951 act.sa_handler = __gnat_error_handler;
1952 act.sa_flags = SA_NODEFER | SA_RESTART;
1953 sigemptyset (&act.sa_mask);
1954
1955 /* Do not install handlers if interrupt state is "System" */
1956 if (__gnat_get_interrupt_state (SIGFPE) != 's')
1957 sigaction (SIGFPE, &act, NULL);
1958 if (__gnat_get_interrupt_state (SIGILL) != 's')
1959 sigaction (SIGILL, &act, NULL);
1960 if (__gnat_get_interrupt_state (SIGSEGV) != 's')
1961 sigaction (SIGSEGV, &act, NULL);
1962 if (__gnat_get_interrupt_state (SIGBUS) != 's')
1963 sigaction (SIGBUS, &act, NULL);
1964
1965 __gnat_handler_installed = 1;
1966 }
1967
1968 /******************/
1969 /* Darwin Section */
1970 /******************/
1971
1972 #elif defined(__APPLE__)
1973
1974 #include <signal.h>
1975 #include <sys/syscall.h>
1976 #include <mach/mach_vm.h>
1977 #include <mach/mach_init.h>
1978 #include <mach/vm_statistics.h>
1979
1980 /* This must be in keeping with System.OS_Interface.Alternate_Stack_Size. */
1981 char __gnat_alternate_stack[32 * 1024]; /* 1 * MINSIGSTKSZ */
1982
1983 /* Defined in xnu unix_signal.c.
1984 Tell the kernel to re-use alt stack when delivering a signal. */
1985 #define UC_RESET_ALT_STACK 0x80000000
1986
1987 /* Return true if ADDR is within a stack guard area. */
1988 static int
1989 __gnat_is_stack_guard (mach_vm_address_t addr)
1990 {
1991 kern_return_t kret;
1992 vm_region_submap_info_data_64_t info;
1993 mach_vm_address_t start;
1994 mach_vm_size_t size;
1995 natural_t depth;
1996 mach_msg_type_number_t count;
1997
1998 count = VM_REGION_SUBMAP_INFO_COUNT_64;
1999 start = addr;
2000 size = -1;
2001 depth = 9999;
2002 kret = mach_vm_region_recurse (mach_task_self (), &start, &size, &depth,
2003 (vm_region_recurse_info_t) &info, &count);
2004 if (kret == KERN_SUCCESS
2005 && addr >= start && addr < (start + size)
2006 && info.protection == VM_PROT_NONE
2007 && info.user_tag == VM_MEMORY_STACK)
2008 return 1;
2009 return 0;
2010 }
2011
2012 #define HAVE_GNAT_ADJUST_CONTEXT_FOR_RAISE
2013
2014 void
2015 __gnat_adjust_context_for_raise (int signo ATTRIBUTE_UNUSED,
2016 void *ucontext ATTRIBUTE_UNUSED)
2017 {
2018 #if defined (__x86_64__)
2019 /* Work around radar #10302855/pr50678, where the unwinders (libunwind or
2020 libgcc_s depending on the system revision) and the DWARF unwind data for
2021 the sigtramp have different ideas about register numbering (causing rbx
2022 and rdx to be transposed).. */
2023 ucontext_t *uc = (ucontext_t *)ucontext ;
2024 unsigned long t = uc->uc_mcontext->__ss.__rbx;
2025
2026 uc->uc_mcontext->__ss.__rbx = uc->uc_mcontext->__ss.__rdx;
2027 uc->uc_mcontext->__ss.__rdx = t;
2028 #endif
2029 }
2030
2031 static void
2032 __gnat_error_handler (int sig, siginfo_t *si, void *ucontext)
2033 {
2034 struct Exception_Data *exception;
2035 const char *msg;
2036
2037 __gnat_adjust_context_for_raise (sig, ucontext);
2038
2039 switch (sig)
2040 {
2041 case SIGSEGV:
2042 case SIGBUS:
2043 if (__gnat_is_stack_guard ((unsigned long)si->si_addr))
2044 {
2045 exception = &storage_error;
2046 msg = "stack overflow";
2047 }
2048 else
2049 {
2050 exception = &constraint_error;
2051 msg = "erroneous memory access";
2052 }
2053 /* Reset the use of alt stack, so that the alt stack will be used
2054 for the next signal delivery.
2055 The stack can't be used in case of stack checking. */
2056 syscall (SYS_sigreturn, NULL, UC_RESET_ALT_STACK);
2057 break;
2058
2059 case SIGFPE:
2060 exception = &constraint_error;
2061 msg = "SIGFPE";
2062 break;
2063
2064 default:
2065 exception = &program_error;
2066 msg = "unhandled signal";
2067 }
2068
2069 Raise_From_Signal_Handler (exception, msg);
2070 }
2071
2072 void
2073 __gnat_install_handler (void)
2074 {
2075 struct sigaction act;
2076
2077 /* Set up signal handler to map synchronous signals to appropriate
2078 exceptions. Make sure that the handler isn't interrupted by another
2079 signal that might cause a scheduling event! Also setup an alternate
2080 stack region for the handler execution so that stack overflows can be
2081 handled properly, avoiding a SEGV generation from stack usage by the
2082 handler itself (and it is required by Darwin). */
2083
2084 stack_t stack;
2085 stack.ss_sp = __gnat_alternate_stack;
2086 stack.ss_size = sizeof (__gnat_alternate_stack);
2087 stack.ss_flags = 0;
2088 sigaltstack (&stack, NULL);
2089
2090 act.sa_flags = SA_NODEFER | SA_RESTART | SA_SIGINFO;
2091 act.sa_sigaction = __gnat_error_handler;
2092 sigemptyset (&act.sa_mask);
2093
2094 /* Do not install handlers if interrupt state is "System". */
2095 if (__gnat_get_interrupt_state (SIGABRT) != 's')
2096 sigaction (SIGABRT, &act, NULL);
2097 if (__gnat_get_interrupt_state (SIGFPE) != 's')
2098 sigaction (SIGFPE, &act, NULL);
2099 if (__gnat_get_interrupt_state (SIGILL) != 's')
2100 sigaction (SIGILL, &act, NULL);
2101
2102 act.sa_flags |= SA_ONSTACK;
2103 if (__gnat_get_interrupt_state (SIGSEGV) != 's')
2104 sigaction (SIGSEGV, &act, NULL);
2105 if (__gnat_get_interrupt_state (SIGBUS) != 's')
2106 sigaction (SIGBUS, &act, NULL);
2107
2108 __gnat_handler_installed = 1;
2109 }
2110
2111 #else
2112
2113 /* For all other versions of GNAT, the handler does nothing. */
2114
2115 /*******************/
2116 /* Default Section */
2117 /*******************/
2118
2119 void
2120 __gnat_install_handler (void)
2121 {
2122 __gnat_handler_installed = 1;
2123 }
2124
2125 #endif
2126
2127 /*********************/
2128 /* __gnat_init_float */
2129 /*********************/
2130
2131 /* This routine is called as each process thread is created, for possible
2132 initialization of the FP processor. This version is used under INTERIX
2133 and WIN32. */
2134
2135 #if defined (_WIN32) || defined (__INTERIX) \
2136 || defined (__Lynx__) || defined(__NetBSD__) || defined(__FreeBSD__) \
2137 || defined (__OpenBSD__)
2138
2139 #define HAVE_GNAT_INIT_FLOAT
2140
2141 void
2142 __gnat_init_float (void)
2143 {
2144 #if defined (__i386__) || defined (i386) || defined (__x86_64)
2145
2146 /* This is used to properly initialize the FPU on an x86 for each
2147 process thread. */
2148
2149 asm ("finit");
2150
2151 #endif /* Defined __i386__ */
2152 }
2153 #endif
2154
2155 #ifndef HAVE_GNAT_INIT_FLOAT
2156
2157 /* All targets without a specific __gnat_init_float will use an empty one. */
2158 void
2159 __gnat_init_float (void)
2160 {
2161 }
2162 #endif
2163
2164 /***********************************/
2165 /* __gnat_adjust_context_for_raise */
2166 /***********************************/
2167
2168 #ifndef HAVE_GNAT_ADJUST_CONTEXT_FOR_RAISE
2169
2170 /* All targets without a specific version will use an empty one. */
2171
2172 /* Given UCONTEXT a pointer to a context structure received by a signal
2173 handler for SIGNO, perform the necessary adjustments to let the handler
2174 raise an exception. Calls to this routine are not conditioned by the
2175 propagation scheme in use. */
2176
2177 void
2178 __gnat_adjust_context_for_raise (int signo ATTRIBUTE_UNUSED,
2179 void *ucontext ATTRIBUTE_UNUSED)
2180 {
2181 /* We used to compensate here for the raised from call vs raised from signal
2182 exception discrepancy with the GCC ZCX scheme, but this now can be dealt
2183 with generically in the unwinder (see GCC PR other/26208). This however
2184 requires the use of the _Unwind_GetIPInfo routine in raise-gcc.c, which
2185 is predicated on the definition of HAVE_GETIPINFO at compile time. Only
2186 the VMS ports still do the compensation described in the few lines below.
2187
2188 *** Call vs signal exception discrepancy with GCC ZCX scheme ***
2189
2190 The GCC unwinder expects to be dealing with call return addresses, since
2191 this is the "nominal" case of what we retrieve while unwinding a regular
2192 call chain.
2193
2194 To evaluate if a handler applies at some point identified by a return
2195 address, the propagation engine needs to determine what region the
2196 corresponding call instruction pertains to. Because the return address
2197 may not be attached to the same region as the call, the unwinder always
2198 subtracts "some" amount from a return address to search the region
2199 tables, amount chosen to ensure that the resulting address is inside the
2200 call instruction.
2201
2202 When we raise an exception from a signal handler, e.g. to transform a
2203 SIGSEGV into Storage_Error, things need to appear as if the signal
2204 handler had been "called" by the instruction which triggered the signal,
2205 so that exception handlers that apply there are considered. What the
2206 unwinder will retrieve as the return address from the signal handler is
2207 what it will find as the faulting instruction address in the signal
2208 context pushed by the kernel. Leaving this address untouched looses, if
2209 the triggering instruction happens to be the very first of a region, as
2210 the later adjustments performed by the unwinder would yield an address
2211 outside that region. We need to compensate for the unwinder adjustments
2212 at some point, and this is what this routine is expected to do.
2213
2214 signo is passed because on some targets for some signals the PC in
2215 context points to the instruction after the faulting one, in which case
2216 the unwinder adjustment is still desired. */
2217 }
2218
2219 #endif
2220
2221 #ifdef __cplusplus
2222 }
2223 #endif
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