1 /****************************************************************************
3 * GNAT COMPILER COMPONENTS *
7 * C Implementation File *
9 * Copyright (C) 1992-2009, Free Software Foundation, Inc. *
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. *
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. *
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/>. *
27 * GNAT was originally developed by the GNAT team at New York University. *
28 * Extensive contributions were provided by Ada Core Technologies Inc. *
30 ****************************************************************************/
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). */
41 /* This file should be kept synchronized with 2sinit.ads, 2sinit.adb,
42 s-init-ae653-cert.adb and s-init-xi-sparc.adb. All these files implement
43 the required functionality for different targets. */
45 /* The following include is here to meet the published VxWorks requirement
46 that the __vxworks header appear before any other include. */
56 /* We don't have libiberty, so use malloc. */
57 #define xmalloc(S) malloc (S)
66 extern void __gnat_raise_program_error (const char *, int);
68 /* Addresses of exception data blocks for predefined exceptions. Tasking_Error
69 is not used in this unit, and the abort signal is only used on IRIX. */
70 extern struct Exception_Data constraint_error;
71 extern struct Exception_Data numeric_error;
72 extern struct Exception_Data program_error;
73 extern struct Exception_Data storage_error;
75 /* For the Cert run time we use the regular raise exception routine because
76 Raise_From_Signal_Handler is not available. */
78 #define Raise_From_Signal_Handler \
79 __gnat_raise_exception
80 extern void Raise_From_Signal_Handler (struct Exception_Data *, const char *);
82 #define Raise_From_Signal_Handler \
83 ada__exceptions__raise_from_signal_handler
84 extern void Raise_From_Signal_Handler (struct Exception_Data *, const char *);
87 /* Global values computed by the binder. */
88 int __gl_main_priority = -1;
89 int __gl_time_slice_val = -1;
90 char __gl_wc_encoding = 'n';
91 char __gl_locking_policy = ' ';
92 char __gl_queuing_policy = ' ';
93 char __gl_task_dispatching_policy = ' ';
94 char *__gl_priority_specific_dispatching = 0;
95 int __gl_num_specific_dispatching = 0;
96 char *__gl_interrupt_states = 0;
97 int __gl_num_interrupt_states = 0;
98 int __gl_unreserve_all_interrupts = 0;
99 int __gl_exception_tracebacks = 0;
100 int __gl_zero_cost_exceptions = 0;
101 int __gl_detect_blocking = 0;
102 int __gl_default_stack_size = -1;
103 int __gl_leap_seconds_support = 0;
104 int __gl_canonical_streams = 0;
106 /* Indication of whether synchronous signal handler has already been
107 installed by a previous call to adainit. */
108 int __gnat_handler_installed = 0;
111 int __gnat_inside_elab_final_code = 0;
112 /* ??? This variable is obsolete since 2001-08-29 but is kept to allow
113 bootstrap from old GNAT versions (< 3.15). */
116 /* HAVE_GNAT_INIT_FLOAT must be set on every targets where a __gnat_init_float
117 is defined. If this is not set then a void implementation will be defined
118 at the end of this unit. */
119 #undef HAVE_GNAT_INIT_FLOAT
121 /******************************/
122 /* __gnat_get_interrupt_state */
123 /******************************/
125 char __gnat_get_interrupt_state (int);
127 /* This routine is called from the runtime as needed to determine the state
128 of an interrupt, as set by an Interrupt_State pragma appearing anywhere
129 in the current partition. The input argument is the interrupt number,
130 and the result is one of the following:
132 'n' this interrupt not set by any Interrupt_State pragma
133 'u' Interrupt_State pragma set state to User
134 'r' Interrupt_State pragma set state to Runtime
135 's' Interrupt_State pragma set state to System */
138 __gnat_get_interrupt_state (int intrup)
140 if (intrup >= __gl_num_interrupt_states)
143 return __gl_interrupt_states [intrup];
146 /***********************************/
147 /* __gnat_get_specific_dispatching */
148 /***********************************/
150 char __gnat_get_specific_dispatching (int);
152 /* This routine is called from the runtime as needed to determine the
153 priority specific dispatching policy, as set by a
154 Priority_Specific_Dispatching pragma appearing anywhere in the current
155 partition. The input argument is the priority number, and the result
156 is the upper case first character of the policy name, e.g. 'F' for
157 FIFO_Within_Priorities. A space ' ' is returned if no
158 Priority_Specific_Dispatching pragma is used in the partition. */
161 __gnat_get_specific_dispatching (int priority)
163 if (__gl_num_specific_dispatching == 0)
165 else if (priority >= __gl_num_specific_dispatching)
168 return __gl_priority_specific_dispatching [priority];
173 /**********************/
174 /* __gnat_set_globals */
175 /**********************/
177 /* This routine is kept for bootstrapping purposes, since the binder generated
178 file now sets the __gl_* variables directly. */
181 __gnat_set_globals ()
194 #include <sys/time.h>
196 /* Some versions of AIX don't define SA_NODEFER. */
200 #endif /* SA_NODEFER */
202 /* Versions of AIX before 4.3 don't have nanosleep but provide
205 #ifndef _AIXVERSION_430
207 extern int nanosleep (struct timestruc_t *, struct timestruc_t *);
210 nanosleep (struct timestruc_t *Rqtp, struct timestruc_t *Rmtp)
212 return nsleep (Rqtp, Rmtp);
215 #endif /* _AIXVERSION_430 */
217 static void __gnat_error_handler (int sig, siginfo_t * si, void * uc);
220 __gnat_error_handler (int sig, siginfo_t * si, void * uc)
222 struct Exception_Data *exception;
228 /* FIXME: we need to detect the case of a *real* SIGSEGV. */
229 exception = &storage_error;
230 msg = "stack overflow or erroneous memory access";
234 exception = &constraint_error;
239 exception = &constraint_error;
244 exception = &program_error;
245 msg = "unhandled signal";
248 Raise_From_Signal_Handler (exception, msg);
252 __gnat_install_handler (void)
254 struct sigaction act;
256 /* Set up signal handler to map synchronous signals to appropriate
257 exceptions. Make sure that the handler isn't interrupted by another
258 signal that might cause a scheduling event! */
260 act.sa_flags = SA_NODEFER | SA_RESTART | SA_SIGINFO;
261 act.sa_sigaction = __gnat_error_handler;
262 sigemptyset (&act.sa_mask);
264 /* Do not install handlers if interrupt state is "System". */
265 if (__gnat_get_interrupt_state (SIGABRT) != 's')
266 sigaction (SIGABRT, &act, NULL);
267 if (__gnat_get_interrupt_state (SIGFPE) != 's')
268 sigaction (SIGFPE, &act, NULL);
269 if (__gnat_get_interrupt_state (SIGILL) != 's')
270 sigaction (SIGILL, &act, NULL);
271 if (__gnat_get_interrupt_state (SIGSEGV) != 's')
272 sigaction (SIGSEGV, &act, NULL);
273 if (__gnat_get_interrupt_state (SIGBUS) != 's')
274 sigaction (SIGBUS, &act, NULL);
276 __gnat_handler_installed = 1;
283 #elif defined(__alpha__) && defined(__osf__)
286 #include <sys/siginfo.h>
288 static void __gnat_error_handler (int, siginfo_t *, struct sigcontext *);
289 extern char *__gnat_get_code_loc (struct sigcontext *);
290 extern void __gnat_set_code_loc (struct sigcontext *, char *);
291 extern size_t __gnat_machine_state_length (void);
293 #define HAVE_GNAT_ADJUST_CONTEXT_FOR_RAISE
296 __gnat_adjust_context_for_raise (int signo, void *ucontext)
298 struct sigcontext *sigcontext = (struct sigcontext *) ucontext;
300 /* The unwinder expects the signal context to contain the address of the
301 faulting instruction. For SIGFPE, this depends on the trap shadow
302 situation (see man ieee). We nonetheless always compensate for it,
303 considering that PC designates the instruction following the one that
304 trapped. This is not necessarily true but corresponds to what we have
312 (int sig, siginfo_t *sip, struct sigcontext *context)
314 struct Exception_Data *exception;
315 static int recurse = 0;
318 /* Adjusting is required for every fault context, so adjust for this one
319 now, before we possibly trigger a recursive fault below. */
320 __gnat_adjust_context_for_raise (sig, context);
322 /* If this was an explicit signal from a "kill", just resignal it. */
323 if (SI_FROMUSER (sip))
325 signal (sig, SIG_DFL);
326 kill (getpid(), sig);
329 /* Otherwise, treat it as something we handle. */
333 /* If the problem was permissions, this is a constraint error.
334 Likewise if the failing address isn't maximally aligned or if
337 ??? Using a static variable here isn't task-safe, but it's
338 much too hard to do anything else and we're just determining
339 which exception to raise. */
340 if (sip->si_code == SEGV_ACCERR
341 || (((long) sip->si_addr) & 3) != 0
344 exception = &constraint_error;
349 /* See if the page before the faulting page is accessible. Do that
350 by trying to access it. We'd like to simply try to access
351 4096 + the faulting address, but it's not guaranteed to be
352 the actual address, just to be on the same page. */
355 ((long) sip->si_addr & - getpagesize ()))[getpagesize ()];
356 msg = "stack overflow (or erroneous memory access)";
357 exception = &storage_error;
362 exception = &program_error;
367 exception = &constraint_error;
372 exception = &program_error;
373 msg = "unhandled signal";
377 Raise_From_Signal_Handler (exception, (char *) msg);
381 __gnat_install_handler (void)
383 struct sigaction act;
385 /* Setup signal handler to map synchronous signals to appropriate
386 exceptions. Make sure that the handler isn't interrupted by another
387 signal that might cause a scheduling event! */
389 act.sa_handler = (void (*) (int)) __gnat_error_handler;
390 act.sa_flags = SA_RESTART | SA_NODEFER | SA_SIGINFO;
391 sigemptyset (&act.sa_mask);
393 /* Do not install handlers if interrupt state is "System". */
394 if (__gnat_get_interrupt_state (SIGABRT) != 's')
395 sigaction (SIGABRT, &act, NULL);
396 if (__gnat_get_interrupt_state (SIGFPE) != 's')
397 sigaction (SIGFPE, &act, NULL);
398 if (__gnat_get_interrupt_state (SIGILL) != 's')
399 sigaction (SIGILL, &act, NULL);
400 if (__gnat_get_interrupt_state (SIGSEGV) != 's')
401 sigaction (SIGSEGV, &act, NULL);
402 if (__gnat_get_interrupt_state (SIGBUS) != 's')
403 sigaction (SIGBUS, &act, NULL);
405 __gnat_handler_installed = 1;
408 /* Routines called by s-mastop-tru64.adb. */
413 __gnat_get_code_loc (struct sigcontext *context)
415 return (char *) context->sc_pc;
419 __gnat_set_code_loc (struct sigcontext *context, char *pc)
421 context->sc_pc = (long) pc;
425 __gnat_machine_state_length (void)
427 return sizeof (struct sigcontext);
434 #elif defined (__hpux__)
437 #include <sys/ucontext.h>
440 __gnat_error_handler (int sig, siginfo_t *siginfo, void *ucontext);
444 (int sig, siginfo_t *siginfo ATTRIBUTE_UNUSED, void *ucontext)
446 struct Exception_Data *exception;
452 /* FIXME: we need to detect the case of a *real* SIGSEGV. */
453 exception = &storage_error;
454 msg = "stack overflow or erroneous memory access";
458 exception = &constraint_error;
463 exception = &constraint_error;
468 exception = &program_error;
469 msg = "unhandled signal";
472 Raise_From_Signal_Handler (exception, msg);
475 /* This must be in keeping with System.OS_Interface.Alternate_Stack_Size. */
476 #if defined (__hppa__)
477 char __gnat_alternate_stack[16 * 1024]; /* 2 * SIGSTKSZ */
479 char __gnat_alternate_stack[128 * 1024]; /* MINSIGSTKSZ */
483 __gnat_install_handler (void)
485 struct sigaction act;
487 /* Set up signal handler to map synchronous signals to appropriate
488 exceptions. Make sure that the handler isn't interrupted by another
489 signal that might cause a scheduling event! Also setup an alternate
490 stack region for the handler execution so that stack overflows can be
491 handled properly, avoiding a SEGV generation from stack usage by the
495 stack.ss_sp = __gnat_alternate_stack;
496 stack.ss_size = sizeof (__gnat_alternate_stack);
498 sigaltstack (&stack, NULL);
500 act.sa_sigaction = __gnat_error_handler;
501 act.sa_flags = SA_NODEFER | SA_RESTART | SA_SIGINFO;
502 sigemptyset (&act.sa_mask);
504 /* Do not install handlers if interrupt state is "System". */
505 if (__gnat_get_interrupt_state (SIGABRT) != 's')
506 sigaction (SIGABRT, &act, NULL);
507 if (__gnat_get_interrupt_state (SIGFPE) != 's')
508 sigaction (SIGFPE, &act, NULL);
509 if (__gnat_get_interrupt_state (SIGILL) != 's')
510 sigaction (SIGILL, &act, NULL);
511 if (__gnat_get_interrupt_state (SIGBUS) != 's')
512 sigaction (SIGBUS, &act, NULL);
513 act.sa_flags |= SA_ONSTACK;
514 if (__gnat_get_interrupt_state (SIGSEGV) != 's')
515 sigaction (SIGSEGV, &act, NULL);
517 __gnat_handler_installed = 1;
520 /*********************/
521 /* GNU/Linux Section */
522 /*********************/
524 #elif defined (linux) && (defined (i386) || defined (__x86_64__) \
525 || defined (__ia64__) || defined (__powerpc__))
529 #define __USE_GNU 1 /* required to get REG_EIP/RIP from glibc's ucontext.h */
530 #include <sys/ucontext.h>
532 /* GNU/Linux, which uses glibc, does not define NULL in included
536 #define NULL ((void *) 0)
541 /* MaRTE OS provides its own version of sigaction, sigfillset, and
542 sigemptyset (overriding these symbol names). We want to make sure that
543 the versions provided by the underlying C library are used here (these
544 versions are renamed by MaRTE to linux_sigaction, fake_linux_sigfillset,
545 and fake_linux_sigemptyset, respectively). The MaRTE library will not
546 always be present (it will not be linked if no tasking constructs are
547 used), so we use the weak symbol mechanism to point always to the symbols
548 defined within the C library. */
550 #pragma weak linux_sigaction
551 int linux_sigaction (int signum, const struct sigaction *act,
552 struct sigaction *oldact) {
553 return sigaction (signum, act, oldact);
555 #define sigaction(signum, act, oldact) linux_sigaction (signum, act, oldact)
557 #pragma weak fake_linux_sigfillset
558 void fake_linux_sigfillset (sigset_t *set) {
561 #define sigfillset(set) fake_linux_sigfillset (set)
563 #pragma weak fake_linux_sigemptyset
564 void fake_linux_sigemptyset (sigset_t *set) {
567 #define sigemptyset(set) fake_linux_sigemptyset (set)
571 static void __gnat_error_handler (int, siginfo_t *siginfo, void *ucontext);
573 #if defined (i386) || defined (__x86_64__) || defined (__ia64__)
575 #define HAVE_GNAT_ADJUST_CONTEXT_FOR_RAISE
578 __gnat_adjust_context_for_raise (int signo ATTRIBUTE_UNUSED, void *ucontext)
580 mcontext_t *mcontext = &((ucontext_t *) ucontext)->uc_mcontext;
582 /* On the i386 and x86-64 architectures, stack checking is performed by
583 means of probes with moving stack pointer, that is to say the probed
584 address is always the value of the stack pointer. Upon hitting the
585 guard page, the stack pointer therefore points to an inaccessible
586 address and an alternate signal stack is needed to run the handler.
587 But there is an additional twist: on these architectures, the EH
588 return code writes the address of the handler at the target CFA's
589 value on the stack before doing the jump. As a consequence, if
590 there is an active handler in the frame whose stack has overflowed,
591 the stack pointer must nevertheless point to an accessible address
592 by the time the EH return is executed.
594 We therefore adjust the saved value of the stack pointer by the size
595 of one page + a small dope of 4 words, in order to make sure that it
596 points to an accessible address in case it's used as the target CFA.
597 The stack checking code guarantees that this address is unused by the
598 time this happens. */
601 unsigned long pattern = *(unsigned long *)mcontext->gregs[REG_EIP];
602 /* The pattern is "orl $0x0,(%esp)" for a probe in 32-bit mode. */
603 if (signo == SIGSEGV && pattern == 0x00240c83)
604 mcontext->gregs[REG_ESP] += 4096 + 4 * sizeof (unsigned long);
605 #elif defined (__x86_64__)
606 unsigned long pattern = *(unsigned long *)mcontext->gregs[REG_RIP];
607 /* The pattern is "orq $0x0,(%rsp)" for a probe in 64-bit mode. */
608 if (signo == SIGSEGV && (pattern & 0xffffffffff) == 0x00240c8348)
609 mcontext->gregs[REG_RSP] += 4096 + 4 * sizeof (unsigned long);
610 #elif defined (__ia64__)
611 /* ??? The IA-64 unwinder doesn't compensate for signals. */
619 __gnat_error_handler (int sig,
620 siginfo_t *siginfo ATTRIBUTE_UNUSED,
623 struct Exception_Data *exception;
625 static int recurse = 0;
630 /* If the problem was permissions, this is a constraint error.
631 Likewise if the failing address isn't maximally aligned or if
634 ??? Using a static variable here isn't task-safe, but it's
635 much too hard to do anything else and we're just determining
636 which exception to raise. */
639 exception = &constraint_error;
644 /* Here we would like a discrimination test to see whether the
645 page before the faulting address is accessible. Unfortunately
646 Linux seems to have no way of giving us the faulting address.
648 In versions of a-init.c before 1.95, we had a test of the page
649 before the stack pointer using:
653 ((long) info->esp_at_signal & - getpagesize ()))[getpagesize ()];
655 but that's wrong, since it tests the stack pointer location, and
656 the current stack probe code does not move the stack pointer
657 until all probes succeed.
659 For now we simply do not attempt any discrimination at all. Note
660 that this is quite acceptable, since a "real" SIGSEGV can only
661 occur as the result of an erroneous program. */
663 msg = "stack overflow (or erroneous memory access)";
664 exception = &storage_error;
669 exception = &constraint_error;
674 exception = &constraint_error;
679 exception = &program_error;
680 msg = "unhandled signal";
684 /* We adjust the interrupted context here (and not in the fallback
685 unwinding routine) because recent versions of the Native POSIX
686 Thread Library (NPTL) are compiled with unwind information, so
687 the fallback routine is never executed for signal frames. */
688 __gnat_adjust_context_for_raise (sig, ucontext);
690 Raise_From_Signal_Handler (exception, msg);
693 #if defined (i386) || defined (__x86_64__)
694 /* This must be in keeping with System.OS_Interface.Alternate_Stack_Size. */
695 char __gnat_alternate_stack[16 * 1024]; /* 2 * SIGSTKSZ */
699 #include <sys/mman.h>
700 #include <native/task.h>
706 __gnat_install_handler (void)
708 struct sigaction act;
713 if (__gl_main_priority == -1)
716 prio = __gl_main_priority;
718 /* Avoid memory swapping for this program */
720 mlockall (MCL_CURRENT|MCL_FUTURE);
722 /* Turn the current Linux task into a native Xenomai task */
724 rt_task_shadow(&main_task, "environment_task", prio, T_FPU);
727 /* Set up signal handler to map synchronous signals to appropriate
728 exceptions. Make sure that the handler isn't interrupted by another
729 signal that might cause a scheduling event! Also setup an alternate
730 stack region for the handler execution so that stack overflows can be
731 handled properly, avoiding a SEGV generation from stack usage by the
734 #if defined (i386) || defined (__x86_64__)
736 stack.ss_sp = __gnat_alternate_stack;
737 stack.ss_size = sizeof (__gnat_alternate_stack);
739 sigaltstack (&stack, NULL);
742 act.sa_sigaction = __gnat_error_handler;
743 act.sa_flags = SA_NODEFER | SA_RESTART | SA_SIGINFO;
744 sigemptyset (&act.sa_mask);
746 /* Do not install handlers if interrupt state is "System". */
747 if (__gnat_get_interrupt_state (SIGABRT) != 's')
748 sigaction (SIGABRT, &act, NULL);
749 if (__gnat_get_interrupt_state (SIGFPE) != 's')
750 sigaction (SIGFPE, &act, NULL);
751 if (__gnat_get_interrupt_state (SIGILL) != 's')
752 sigaction (SIGILL, &act, NULL);
753 if (__gnat_get_interrupt_state (SIGBUS) != 's')
754 sigaction (SIGBUS, &act, NULL);
755 #if defined (i386) || defined (__x86_64__)
756 act.sa_flags |= SA_ONSTACK;
758 if (__gnat_get_interrupt_state (SIGSEGV) != 's')
759 sigaction (SIGSEGV, &act, NULL);
761 __gnat_handler_installed = 1;
777 #define SIGADAABORT 48
778 #define SIGNAL_STACK_SIZE 4096
779 #define SIGNAL_STACK_ALIGNMENT 64
781 #define Check_Abort_Status \
782 system__soft_links__check_abort_status
783 extern int (*Check_Abort_Status) (void);
785 extern struct Exception_Data _abort_signal;
787 static void __gnat_error_handler (int, int, sigcontext_t *);
789 /* We are not setting the SA_SIGINFO bit in the sigaction flags when
790 connecting that handler, with the effects described in the sigaction
794 If cleared and the signal is caught, the first argument is
795 also the signal number but the second argument is the signal
796 code identifying the cause of the signal. The third argument
797 points to a sigcontext_t structure containing the receiving
798 process's context when the signal was delivered. */
801 __gnat_error_handler (int sig, int code, sigcontext_t *sc ATTRIBUTE_UNUSED)
803 struct Exception_Data *exception;
811 exception = &program_error;
812 msg = "SIGSEGV: (Invalid virtual address)";
814 else if (code == ENXIO)
816 exception = &program_error;
817 msg = "SIGSEGV: (Read beyond mapped object)";
819 else if (code == ENOSPC)
821 exception = &program_error; /* ??? storage_error ??? */
822 msg = "SIGSEGV: (Autogrow for file failed)";
824 else if (code == EACCES || code == EEXIST)
826 /* ??? We handle stack overflows here, some of which do trigger
827 SIGSEGV + EEXIST on Irix 6.5 although EEXIST is not part of
828 the documented valid codes for SEGV in the signal(5) man
831 /* ??? Re-add smarts to further verify that we launched
832 the stack into a guard page, not an attempt to
833 write to .text or something. */
834 exception = &storage_error;
835 msg = "SIGSEGV: (stack overflow or erroneous memory access)";
839 /* Just in case the OS guys did it to us again. Sometimes
840 they fail to document all of the valid codes that are
841 passed to signal handlers, just in case someone depends
842 on knowing all the codes. */
843 exception = &program_error;
844 msg = "SIGSEGV: (Undocumented reason)";
849 /* Map all bus errors to Program_Error. */
850 exception = &program_error;
855 /* Map all fpe errors to Constraint_Error. */
856 exception = &constraint_error;
861 if ((*Check_Abort_Status) ())
863 exception = &_abort_signal;
872 /* Everything else is a Program_Error. */
873 exception = &program_error;
874 msg = "unhandled signal";
877 Raise_From_Signal_Handler (exception, msg);
881 __gnat_install_handler (void)
883 struct sigaction act;
885 /* Setup signal handler to map synchronous signals to appropriate
886 exceptions. Make sure that the handler isn't interrupted by another
887 signal that might cause a scheduling event! */
889 act.sa_handler = __gnat_error_handler;
890 act.sa_flags = SA_NODEFER + SA_RESTART;
891 sigfillset (&act.sa_mask);
892 sigemptyset (&act.sa_mask);
894 /* Do not install handlers if interrupt state is "System". */
895 if (__gnat_get_interrupt_state (SIGABRT) != 's')
896 sigaction (SIGABRT, &act, NULL);
897 if (__gnat_get_interrupt_state (SIGFPE) != 's')
898 sigaction (SIGFPE, &act, NULL);
899 if (__gnat_get_interrupt_state (SIGILL) != 's')
900 sigaction (SIGILL, &act, NULL);
901 if (__gnat_get_interrupt_state (SIGSEGV) != 's')
902 sigaction (SIGSEGV, &act, NULL);
903 if (__gnat_get_interrupt_state (SIGBUS) != 's')
904 sigaction (SIGBUS, &act, NULL);
905 if (__gnat_get_interrupt_state (SIGADAABORT) != 's')
906 sigaction (SIGADAABORT, &act, NULL);
908 __gnat_handler_installed = 1;
911 /*******************/
913 /*******************/
915 #elif defined (__Lynx__)
921 __gnat_error_handler (int sig)
923 struct Exception_Data *exception;
929 exception = &constraint_error;
933 exception = &constraint_error;
937 exception = &storage_error;
938 msg = "stack overflow or erroneous memory access";
941 exception = &constraint_error;
945 exception = &program_error;
946 msg = "unhandled signal";
949 Raise_From_Signal_Handler(exception, msg);
953 __gnat_install_handler(void)
955 struct sigaction act;
957 act.sa_handler = __gnat_error_handler;
959 sigemptyset (&act.sa_mask);
961 /* Do not install handlers if interrupt state is "System". */
962 if (__gnat_get_interrupt_state (SIGFPE) != 's')
963 sigaction (SIGFPE, &act, NULL);
964 if (__gnat_get_interrupt_state (SIGILL) != 's')
965 sigaction (SIGILL, &act, NULL);
966 if (__gnat_get_interrupt_state (SIGSEGV) != 's')
967 sigaction (SIGSEGV, &act, NULL);
968 if (__gnat_get_interrupt_state (SIGBUS) != 's')
969 sigaction (SIGBUS, &act, NULL);
971 __gnat_handler_installed = 1;
974 /*******************/
975 /* Solaris Section */
976 /*******************/
978 #elif defined (sun) && defined (__SVR4) && !defined (__vxworks)
982 #include <sys/ucontext.h>
983 #include <sys/regset.h>
985 /* The code below is common to SPARC and x86. Beware of the delay slot
986 differences for signal context adjustments. */
988 #if defined (__sparc)
989 #define RETURN_ADDR_OFFSET 8
991 #define RETURN_ADDR_OFFSET 0
994 /* Likewise regarding how the "instruction pointer" register slot can
995 be identified in signal machine contexts. We have either "REG_PC"
996 or "PC" at hand, depending on the target CPU and Solaris version. */
998 #if !defined (REG_PC)
1002 static void __gnat_error_handler (int, siginfo_t *, ucontext_t *);
1005 __gnat_error_handler (int sig, siginfo_t *sip, ucontext_t *uctx)
1007 struct Exception_Data *exception;
1008 static int recurse = 0;
1011 /* If this was an explicit signal from a "kill", just resignal it. */
1012 if (SI_FROMUSER (sip))
1014 signal (sig, SIG_DFL);
1015 kill (getpid(), sig);
1018 /* Otherwise, treat it as something we handle. */
1022 /* If the problem was permissions, this is a constraint error.
1023 Likewise if the failing address isn't maximally aligned or if
1026 ??? Using a static variable here isn't task-safe, but it's
1027 much too hard to do anything else and we're just determining
1028 which exception to raise. */
1029 if (sip->si_code == SEGV_ACCERR
1030 || (((long) sip->si_addr) & 3) != 0
1033 exception = &constraint_error;
1038 /* See if the page before the faulting page is accessible. Do that
1039 by trying to access it. We'd like to simply try to access
1040 4096 + the faulting address, but it's not guaranteed to be
1041 the actual address, just to be on the same page. */
1044 ((long) sip->si_addr & - getpagesize ()))[getpagesize ()];
1045 exception = &storage_error;
1046 msg = "stack overflow (or erroneous memory access)";
1051 exception = &program_error;
1056 exception = &constraint_error;
1061 exception = &program_error;
1062 msg = "unhandled signal";
1067 Raise_From_Signal_Handler (exception, msg);
1071 __gnat_install_handler (void)
1073 struct sigaction act;
1075 /* Set up signal handler to map synchronous signals to appropriate
1076 exceptions. Make sure that the handler isn't interrupted by another
1077 signal that might cause a scheduling event! */
1079 act.sa_handler = __gnat_error_handler;
1080 act.sa_flags = SA_NODEFER | SA_RESTART | SA_SIGINFO;
1081 sigemptyset (&act.sa_mask);
1083 /* Do not install handlers if interrupt state is "System". */
1084 if (__gnat_get_interrupt_state (SIGABRT) != 's')
1085 sigaction (SIGABRT, &act, NULL);
1086 if (__gnat_get_interrupt_state (SIGFPE) != 's')
1087 sigaction (SIGFPE, &act, NULL);
1088 if (__gnat_get_interrupt_state (SIGSEGV) != 's')
1089 sigaction (SIGSEGV, &act, NULL);
1090 if (__gnat_get_interrupt_state (SIGBUS) != 's')
1091 sigaction (SIGBUS, &act, NULL);
1093 __gnat_handler_installed = 1;
1102 /* Routine called from binder to override default feature values. */
1103 void __gnat_set_features ();
1104 int __gnat_features_set = 0;
1106 long __gnat_error_handler (int *, void *);
1109 #define lib_get_curr_invo_context LIB$I64_GET_CURR_INVO_CONTEXT
1110 #define lib_get_prev_invo_context LIB$I64_GET_PREV_INVO_CONTEXT
1111 #define lib_get_invo_handle LIB$I64_GET_INVO_HANDLE
1113 #define lib_get_curr_invo_context LIB$GET_CURR_INVO_CONTEXT
1114 #define lib_get_prev_invo_context LIB$GET_PREV_INVO_CONTEXT
1115 #define lib_get_invo_handle LIB$GET_INVO_HANDLE
1118 #if defined (IN_RTS) && !defined (__IA64)
1120 /* The prehandler actually gets control first on a condition. It swaps the
1121 stack pointer and calls the handler (__gnat_error_handler). */
1122 extern long __gnat_error_prehandler (void);
1124 extern char *__gnat_error_prehandler_stack; /* Alternate signal stack */
1127 /* Define macro symbols for the VMS conditions that become Ada exceptions.
1128 Most of these are also defined in the header file ssdef.h which has not
1129 yet been converted to be recognized by GNU C. */
1131 /* Defining these as macros, as opposed to external addresses, allows
1132 them to be used in a case statement below. */
1133 #define SS$_ACCVIO 12
1134 #define SS$_HPARITH 1284
1135 #define SS$_STKOVF 1364
1136 #define SS$_RESIGNAL 2328
1138 /* These codes are in standard message libraries. */
1139 extern int CMA$_EXIT_THREAD;
1140 extern int SS$_DEBUG;
1141 extern int SS$_INTDIV;
1142 extern int LIB$_KEYNOTFOU;
1143 extern int LIB$_ACTIMAGE;
1144 extern int MTH$_FLOOVEMAT; /* Some ACVC_21 CXA tests */
1146 /* These codes are non standard, which is to say the author is
1147 not sure if they are defined in the standard message libraries
1148 so keep them as macros for now. */
1149 #define RDB$_STREAM_EOF 20480426
1150 #define FDL$_UNPRIKW 11829410
1152 struct cond_except {
1154 const struct Exception_Data *except;
1157 struct descriptor_s {unsigned short len, mbz; __char_ptr32 adr; };
1159 /* Conditions that don't have an Ada exception counterpart must raise
1160 Non_Ada_Error. Since this is defined in s-auxdec, it should only be
1161 referenced by user programs, not the compiler or tools. Hence the
1166 #define Status_Error ada__io_exceptions__status_error
1167 extern struct Exception_Data Status_Error;
1169 #define Mode_Error ada__io_exceptions__mode_error
1170 extern struct Exception_Data Mode_Error;
1172 #define Name_Error ada__io_exceptions__name_error
1173 extern struct Exception_Data Name_Error;
1175 #define Use_Error ada__io_exceptions__use_error
1176 extern struct Exception_Data Use_Error;
1178 #define Device_Error ada__io_exceptions__device_error
1179 extern struct Exception_Data Device_Error;
1181 #define End_Error ada__io_exceptions__end_error
1182 extern struct Exception_Data End_Error;
1184 #define Data_Error ada__io_exceptions__data_error
1185 extern struct Exception_Data Data_Error;
1187 #define Layout_Error ada__io_exceptions__layout_error
1188 extern struct Exception_Data Layout_Error;
1190 #define Non_Ada_Error system__aux_dec__non_ada_error
1191 extern struct Exception_Data Non_Ada_Error;
1193 #define Coded_Exception system__vms_exception_table__coded_exception
1194 extern struct Exception_Data *Coded_Exception (Exception_Code);
1196 #define Base_Code_In system__vms_exception_table__base_code_in
1197 extern Exception_Code Base_Code_In (Exception_Code);
1199 /* DEC Ada exceptions are not defined in a header file, so they
1200 must be declared as external addresses. */
1202 extern int ADA$_PROGRAM_ERROR;
1203 extern int ADA$_LOCK_ERROR;
1204 extern int ADA$_EXISTENCE_ERROR;
1205 extern int ADA$_KEY_ERROR;
1206 extern int ADA$_KEYSIZERR;
1207 extern int ADA$_STAOVF;
1208 extern int ADA$_CONSTRAINT_ERRO;
1209 extern int ADA$_IOSYSFAILED;
1210 extern int ADA$_LAYOUT_ERROR;
1211 extern int ADA$_STORAGE_ERROR;
1212 extern int ADA$_DATA_ERROR;
1213 extern int ADA$_DEVICE_ERROR;
1214 extern int ADA$_END_ERROR;
1215 extern int ADA$_MODE_ERROR;
1216 extern int ADA$_NAME_ERROR;
1217 extern int ADA$_STATUS_ERROR;
1218 extern int ADA$_NOT_OPEN;
1219 extern int ADA$_ALREADY_OPEN;
1220 extern int ADA$_USE_ERROR;
1221 extern int ADA$_UNSUPPORTED;
1222 extern int ADA$_FAC_MODE_MISMAT;
1223 extern int ADA$_ORG_MISMATCH;
1224 extern int ADA$_RFM_MISMATCH;
1225 extern int ADA$_RAT_MISMATCH;
1226 extern int ADA$_MRS_MISMATCH;
1227 extern int ADA$_MRN_MISMATCH;
1228 extern int ADA$_KEY_MISMATCH;
1229 extern int ADA$_MAXLINEXC;
1230 extern int ADA$_LINEXCMRS;
1232 /* DEC Ada specific conditions. */
1233 static const struct cond_except dec_ada_cond_except_table [] = {
1234 {&ADA$_PROGRAM_ERROR, &program_error},
1235 {&ADA$_USE_ERROR, &Use_Error},
1236 {&ADA$_KEYSIZERR, &program_error},
1237 {&ADA$_STAOVF, &storage_error},
1238 {&ADA$_CONSTRAINT_ERRO, &constraint_error},
1239 {&ADA$_IOSYSFAILED, &Device_Error},
1240 {&ADA$_LAYOUT_ERROR, &Layout_Error},
1241 {&ADA$_STORAGE_ERROR, &storage_error},
1242 {&ADA$_DATA_ERROR, &Data_Error},
1243 {&ADA$_DEVICE_ERROR, &Device_Error},
1244 {&ADA$_END_ERROR, &End_Error},
1245 {&ADA$_MODE_ERROR, &Mode_Error},
1246 {&ADA$_NAME_ERROR, &Name_Error},
1247 {&ADA$_STATUS_ERROR, &Status_Error},
1248 {&ADA$_NOT_OPEN, &Use_Error},
1249 {&ADA$_ALREADY_OPEN, &Use_Error},
1250 {&ADA$_USE_ERROR, &Use_Error},
1251 {&ADA$_UNSUPPORTED, &Use_Error},
1252 {&ADA$_FAC_MODE_MISMAT, &Use_Error},
1253 {&ADA$_ORG_MISMATCH, &Use_Error},
1254 {&ADA$_RFM_MISMATCH, &Use_Error},
1255 {&ADA$_RAT_MISMATCH, &Use_Error},
1256 {&ADA$_MRS_MISMATCH, &Use_Error},
1257 {&ADA$_MRN_MISMATCH, &Use_Error},
1258 {&ADA$_KEY_MISMATCH, &Use_Error},
1259 {&ADA$_MAXLINEXC, &constraint_error},
1260 {&ADA$_LINEXCMRS, &constraint_error},
1265 /* Already handled by a pragma Import_Exception
1266 in Aux_IO_Exceptions */
1267 {&ADA$_LOCK_ERROR, &Lock_Error},
1268 {&ADA$_EXISTENCE_ERROR, &Existence_Error},
1269 {&ADA$_KEY_ERROR, &Key_Error},
1274 /* Non-DEC Ada specific conditions. We could probably also put
1275 SS$_HPARITH here and possibly SS$_ACCVIO, SS$_STKOVF. */
1276 static const struct cond_except cond_except_table [] = {
1277 {&MTH$_FLOOVEMAT, &constraint_error},
1278 {&SS$_INTDIV, &constraint_error},
1282 /* To deal with VMS conditions and their mapping to Ada exceptions,
1283 the __gnat_error_handler routine below is installed as an exception
1284 vector having precedence over DEC frame handlers. Some conditions
1285 still need to be handled by such handlers, however, in which case
1286 __gnat_error_handler needs to return SS$_RESIGNAL. Consider for
1287 instance the use of a third party library compiled with DECAda and
1288 performing its own exception handling internally.
1290 To allow some user-level flexibility, which conditions should be
1291 resignaled is controlled by a predicate function, provided with the
1292 condition value and returning a boolean indication stating whether
1293 this condition should be resignaled or not.
1295 That predicate function is called indirectly, via a function pointer,
1296 by __gnat_error_handler, and changing that pointer is allowed to the
1297 the user code by way of the __gnat_set_resignal_predicate interface.
1299 The user level function may then implement what it likes, including
1300 for instance the maintenance of a dynamic data structure if the set
1301 of to be resignalled conditions has to change over the program's
1304 ??? This is not a perfect solution to deal with the possible
1305 interactions between the GNAT and the DECAda exception handling
1306 models and better (more general) schemes are studied. This is so
1307 just provided as a convenient workaround in the meantime, and
1308 should be use with caution since the implementation has been kept
1312 resignal_predicate (int code);
1314 const int *cond_resignal_table [] = {
1319 (int *) RDB$_STREAM_EOF,
1320 (int *) FDL$_UNPRIKW,
1324 const int facility_resignal_table [] = {
1325 0x1380000, /* RDB */
1326 0x2220000, /* SQL */
1330 /* Default GNAT predicate for resignaling conditions. */
1333 __gnat_default_resignal_p (int code)
1337 for (i = 0; facility_resignal_table [i]; i++)
1338 if ((code & 0xfff0000) == facility_resignal_table [i])
1341 for (i = 0, iexcept = 0;
1342 cond_resignal_table [i] &&
1343 !(iexcept = LIB$MATCH_COND (&code, &cond_resignal_table [i]));
1349 /* Static pointer to predicate that the __gnat_error_handler exception
1350 vector invokes to determine if it should resignal a condition. */
1352 static resignal_predicate * __gnat_resignal_p = __gnat_default_resignal_p;
1354 /* User interface to change the predicate pointer to PREDICATE. Reset to
1355 the default if PREDICATE is null. */
1358 __gnat_set_resignal_predicate (resignal_predicate * predicate)
1361 __gnat_resignal_p = __gnat_default_resignal_p;
1363 __gnat_resignal_p = predicate;
1366 /* Should match System.Parameters.Default_Exception_Msg_Max_Length. */
1367 #define Default_Exception_Msg_Max_Length 512
1369 /* Action routine for SYS$PUTMSG. There may be multiple
1370 conditions, each with text to be appended to MESSAGE
1371 and separated by line termination. */
1374 copy_msg (msgdesc, message)
1375 struct descriptor_s *msgdesc;
1378 int len = strlen (message);
1381 /* Check for buffer overflow and skip. */
1382 if (len > 0 && len <= Default_Exception_Msg_Max_Length - 3)
1384 strcat (message, "\r\n");
1388 /* Check for buffer overflow and truncate if necessary. */
1389 copy_len = (len + msgdesc->len <= Default_Exception_Msg_Max_Length - 1 ?
1391 Default_Exception_Msg_Max_Length - 1 - len);
1392 strncpy (&message [len], msgdesc->adr, copy_len);
1393 message [len + copy_len] = 0;
1399 __gnat_handle_vms_condition (int *sigargs, void *mechargs)
1401 struct Exception_Data *exception = 0;
1402 Exception_Code base_code;
1403 struct descriptor_s gnat_facility = {4,0,"GNAT"};
1404 char message [Default_Exception_Msg_Max_Length];
1406 const char *msg = "";
1408 /* Check for conditions to resignal which aren't effected by pragma
1409 Import_Exception. */
1410 if (__gnat_resignal_p (sigargs [1]))
1411 return SS$_RESIGNAL;
1414 /* See if it's an imported exception. Beware that registered exceptions
1415 are bound to their base code, with the severity bits masked off. */
1416 base_code = Base_Code_In ((Exception_Code) sigargs [1]);
1417 exception = Coded_Exception (base_code);
1423 /* Subtract PC & PSL fields which messes with PUTMSG. */
1425 SYS$PUTMSG (sigargs, copy_msg, &gnat_facility, message);
1429 exception->Name_Length = 19;
1430 /* ??? The full name really should be get sys$getmsg returns. */
1431 exception->Full_Name = "IMPORTED_EXCEPTION";
1432 exception->Import_Code = base_code;
1435 /* Do not adjust the program counter as already points to the next
1436 instruction (just after the call to LIB$STOP). */
1437 Raise_From_Signal_Handler (exception, msg);
1446 if (sigargs[3] == 0)
1448 exception = &constraint_error;
1449 msg = "access zero";
1453 exception = &storage_error;
1454 msg = "stack overflow (or erroneous memory access)";
1456 __gnat_adjust_context_for_raise (0, (void *)mechargs);
1460 exception = &storage_error;
1461 msg = "stack overflow";
1462 __gnat_adjust_context_for_raise (0, (void *)mechargs);
1467 return SS$_RESIGNAL; /* toplev.c handles for compiler */
1469 exception = &constraint_error;
1470 msg = "arithmetic error";
1472 /* No need to adjust pc on Alpha: the pc is already on the instruction
1473 after the trapping one. */
1474 __gnat_adjust_context_for_raise (0, (void *)mechargs);
1484 /* Scan the DEC Ada exception condition table for a match and fetch
1485 the associated GNAT exception pointer. */
1487 dec_ada_cond_except_table [i].cond &&
1488 !LIB$MATCH_COND (&sigargs [1],
1489 &dec_ada_cond_except_table [i].cond);
1491 exception = (struct Exception_Data *)
1492 dec_ada_cond_except_table [i].except;
1496 /* Scan the VMS standard condition table for a match and fetch
1497 the associated GNAT exception pointer. */
1499 cond_except_table [i].cond &&
1500 !LIB$MATCH_COND (&sigargs [1], &cond_except_table [i].cond);
1502 exception = (struct Exception_Data *)
1503 cond_except_table [i].except;
1506 /* User programs expect Non_Ada_Error to be raised, reference
1507 DEC Ada test CXCONDHAN. */
1508 exception = &Non_Ada_Error;
1512 exception = &program_error;
1515 /* Subtract PC & PSL fields which messes with PUTMSG. */
1517 SYS$PUTMSG (sigargs, copy_msg, &gnat_facility, message);
1523 Raise_From_Signal_Handler (exception, msg);
1527 __gnat_error_handler (int *sigargs, void *mechargs)
1529 return __gnat_handle_vms_condition (sigargs, mechargs);
1533 __gnat_install_handler (void)
1535 long prvhnd ATTRIBUTE_UNUSED;
1537 #if !defined (IN_RTS)
1538 SYS$SETEXV (1, __gnat_error_handler, 3, &prvhnd);
1541 /* On alpha-vms, we avoid the global vector annoyance thanks to frame based
1542 handlers to turn conditions into exceptions since GCC 3.4. The global
1543 vector is still required for earlier GCC versions. We're resorting to
1544 the __gnat_error_prehandler assembly function in this case. */
1546 #if defined (IN_RTS) && defined (__alpha__)
1547 if ((__GNUC__ * 10 + __GNUC_MINOR__) < 34)
1549 char * c = (char *) xmalloc (2049);
1551 __gnat_error_prehandler_stack = &c[2048];
1552 SYS$SETEXV (1, __gnat_error_prehandler, 3, &prvhnd);
1556 __gnat_handler_installed = 1;
1559 /* __gnat_adjust_context_for_raise for Alpha - see comments along with the
1560 default version later in this file. */
1562 #if defined (IN_RTS) && defined (__alpha__)
1564 #include <vms/chfctxdef.h>
1565 #include <vms/chfdef.h>
1567 #define HAVE_GNAT_ADJUST_CONTEXT_FOR_RAISE
1570 __gnat_adjust_context_for_raise (int signo ATTRIBUTE_UNUSED, void *ucontext)
1572 /* Add one to the address of the instruction signaling the condition,
1573 located in the sigargs array. */
1575 CHF$MECH_ARRAY * mechargs = (CHF$MECH_ARRAY *) ucontext;
1576 CHF$SIGNAL_ARRAY * sigargs
1577 = (CHF$SIGNAL_ARRAY *) mechargs->chf$q_mch_sig_addr;
1579 int vcount = sigargs->chf$is_sig_args;
1580 int * pc_slot = & (&sigargs->chf$l_sig_name)[vcount-2];
1587 /* __gnat_adjust_context_for_raise for ia64. */
1589 #if defined (IN_RTS) && defined (__IA64)
1591 #include <vms/chfctxdef.h>
1592 #include <vms/chfdef.h>
1594 #define HAVE_GNAT_ADJUST_CONTEXT_FOR_RAISE
1596 typedef unsigned long long u64;
1599 __gnat_adjust_context_for_raise (int signo ATTRIBUTE_UNUSED, void *ucontext)
1601 /* Add one to the address of the instruction signaling the condition,
1602 located in the 64bits sigargs array. */
1604 CHF$MECH_ARRAY * mechargs = (CHF$MECH_ARRAY *) ucontext;
1606 CHF64$SIGNAL_ARRAY *chfsig64
1607 = (CHF64$SIGNAL_ARRAY *) mechargs->chf$ph_mch_sig64_addr;
1610 = (u64 *)chfsig64 + 1 + chfsig64->chf64$l_sig_args;
1612 u64 * ih_pc_loc = post_sigarray - 2;
1619 /* Feature logical name and global variable address pair */
1620 struct feature {char *name; int* gl_addr;};
1622 /* Default values for GNAT features set by environment. */
1623 int __gl_no_malloc_64 = 0;
1625 /* Array feature logical names and global variable addresses */
1626 static struct feature features[] = {
1627 {"GNAT$NO_MALLOC_64", &__gl_no_malloc_64},
1631 void __gnat_set_features ()
1633 struct descriptor_s name_desc, result_desc;
1635 unsigned short rlen;
1638 char buff [MAXEQUIV];
1640 /* Loop through features array and test name for enable/disable */
1641 for (i=0; features [i].name; i++)
1643 name_desc.len = strlen (features [i].name);
1645 name_desc.adr = features [i].name;
1647 result_desc.len = MAXEQUIV - 1;
1648 result_desc.mbz = 0;
1649 result_desc.adr = buff;
1651 status = LIB$GET_LOGICAL (&name_desc, &result_desc, &rlen);
1653 if (((status & 1) == 1) && (rlen < MAXEQUIV))
1658 if (strcmp (buff, "ENABLE") == 0)
1659 *features [i].gl_addr = 1;
1660 else if (strcmp (buff, "DISABLE") == 0)
1661 *features [i].gl_addr = 0;
1664 __gnat_features_set = 1;
1667 /*******************/
1668 /* FreeBSD Section */
1669 /*******************/
1671 #elif defined (__FreeBSD__)
1674 #include <sys/ucontext.h>
1677 static void __gnat_error_handler (int, siginfo_t *, ucontext_t *);
1680 __gnat_error_handler (int sig, siginfo_t *info __attribute__ ((unused)),
1681 ucontext_t *ucontext)
1683 struct Exception_Data *exception;
1689 exception = &constraint_error;
1694 exception = &constraint_error;
1699 exception = &storage_error;
1700 msg = "stack overflow or erroneous memory access";
1704 exception = &constraint_error;
1709 exception = &program_error;
1710 msg = "unhandled signal";
1713 Raise_From_Signal_Handler (exception, msg);
1717 __gnat_install_handler ()
1719 struct sigaction act;
1721 /* Set up signal handler to map synchronous signals to appropriate
1722 exceptions. Make sure that the handler isn't interrupted by another
1723 signal that might cause a scheduling event! */
1726 = (void (*)(int, struct __siginfo *, void*)) __gnat_error_handler;
1727 act.sa_flags = SA_NODEFER | SA_RESTART | SA_SIGINFO;
1728 (void) sigemptyset (&act.sa_mask);
1730 (void) sigaction (SIGILL, &act, NULL);
1731 (void) sigaction (SIGFPE, &act, NULL);
1732 (void) sigaction (SIGSEGV, &act, NULL);
1733 (void) sigaction (SIGBUS, &act, NULL);
1735 __gnat_handler_installed = 1;
1738 /*******************/
1739 /* VxWorks Section */
1740 /*******************/
1742 #elif defined(__vxworks)
1745 #include <taskLib.h>
1753 #include "private/vThreadsP.h"
1756 void __gnat_error_handler (int, void *, struct sigcontext *);
1760 /* Directly vectored Interrupt routines are not supported when using RTPs. */
1762 extern int __gnat_inum_to_ivec (int);
1764 /* This is needed by the GNAT run time to handle Vxworks interrupts. */
1766 __gnat_inum_to_ivec (int num)
1768 return INUM_TO_IVEC (num);
1772 #if !defined(__alpha_vxworks) && (_WRS_VXWORKS_MAJOR != 6) && !defined(__RTP__)
1774 /* getpid is used by s-parint.adb, but is not defined by VxWorks, except
1775 on Alpha VxWorks and VxWorks 6.x (including RTPs). */
1777 extern long getpid (void);
1782 return taskIdSelf ();
1786 /* VxWorks 653 vThreads expects the field excCnt to be zeroed when a signal is.
1787 handled. The VxWorks version of longjmp does this; GCC's builtin_longjmp
1790 __gnat_clear_exception_count (void)
1793 WIND_TCB *currentTask = (WIND_TCB *) taskIdSelf();
1795 currentTask->vThreads.excCnt = 0;
1799 /* Handle different SIGnal to exception mappings in different VxWorks
1802 __gnat_map_signal (int sig)
1804 struct Exception_Data *exception;
1810 exception = &constraint_error;
1815 exception = &constraint_error;
1816 msg = "Floating point exception or SIGILL";
1819 exception = &storage_error;
1823 exception = &storage_error;
1824 msg = "SIGBUS: possible stack overflow";
1826 #elif (_WRS_VXWORKS_MAJOR == 6)
1828 exception = &constraint_error;
1832 /* In RTP mode a SIGSEGV is most likely due to a stack overflow,
1833 since stack checking uses the probing mechanism. */
1835 exception = &storage_error;
1836 msg = "SIGSEGV: possible stack overflow";
1839 exception = &program_error;
1843 /* VxWorks 6 kernel mode with probing. SIGBUS for guard page hit */
1845 exception = &storage_error;
1849 exception = &storage_error;
1850 msg = "SIGBUS: possible stack overflow";
1854 /* VxWorks 5: a SIGILL is most likely due to a stack overflow,
1855 since stack checking uses the stack limit mechanism. */
1857 exception = &storage_error;
1858 msg = "SIGILL: possible stack overflow";
1861 exception = &storage_error;
1865 exception = &program_error;
1870 exception = &program_error;
1871 msg = "unhandled signal";
1874 __gnat_clear_exception_count ();
1875 Raise_From_Signal_Handler (exception, msg);
1878 /* Tasking and Non-tasking signal handler. Map SIGnal to Ada exception
1879 propagation after the required low level adjustments. */
1882 __gnat_error_handler (int sig, void * si ATTRIBUTE_UNUSED,
1883 struct sigcontext * sc)
1887 /* VxWorks will always mask out the signal during the signal handler and
1888 will reenable it on a longjmp. GNAT does not generate a longjmp to
1889 return from a signal handler so the signal will still be masked unless
1891 sigprocmask (SIG_SETMASK, NULL, &mask);
1892 sigdelset (&mask, sig);
1893 sigprocmask (SIG_SETMASK, &mask, NULL);
1895 __gnat_map_signal (sig);
1899 __gnat_install_handler (void)
1901 struct sigaction act;
1903 /* Setup signal handler to map synchronous signals to appropriate
1904 exceptions. Make sure that the handler isn't interrupted by another
1905 signal that might cause a scheduling event! */
1907 act.sa_handler = __gnat_error_handler;
1908 act.sa_flags = SA_SIGINFO | SA_ONSTACK;
1909 sigemptyset (&act.sa_mask);
1911 /* For VxWorks, install all signal handlers, since pragma Interrupt_State
1912 applies to vectored hardware interrupts, not signals. */
1913 sigaction (SIGFPE, &act, NULL);
1914 sigaction (SIGILL, &act, NULL);
1915 sigaction (SIGSEGV, &act, NULL);
1916 sigaction (SIGBUS, &act, NULL);
1918 __gnat_handler_installed = 1;
1921 #define HAVE_GNAT_INIT_FLOAT
1924 __gnat_init_float (void)
1926 /* Disable overflow/underflow exceptions on the PPC processor, needed
1927 to get correct Ada semantics. Note that for AE653 vThreads, the HW
1928 overflow settings are an OS configuration issue. The instructions
1929 below have no effect. */
1930 #if defined (_ARCH_PPC) && !defined (_SOFT_FLOAT) && !defined (VTHREADS)
1935 #if (defined (__i386__) || defined (i386)) && !defined (VTHREADS)
1936 /* This is used to properly initialize the FPU on an x86 for each
1941 /* Similarly for SPARC64. Achieved by masking bits in the Trap Enable Mask
1942 field of the Floating-point Status Register (see the SPARC Architecture
1943 Manual Version 9, p 48). */
1944 #if defined (sparc64)
1946 #define FSR_TEM_NVM (1 << 27) /* Invalid operand */
1947 #define FSR_TEM_OFM (1 << 26) /* Overflow */
1948 #define FSR_TEM_UFM (1 << 25) /* Underflow */
1949 #define FSR_TEM_DZM (1 << 24) /* Division by Zero */
1950 #define FSR_TEM_NXM (1 << 23) /* Inexact result */
1954 __asm__("st %%fsr, %0" : "=m" (fsr));
1955 fsr &= ~(FSR_TEM_OFM | FSR_TEM_UFM);
1956 __asm__("ld %0, %%fsr" : : "m" (fsr));
1961 /* This subprogram is called by System.Task_Primitives.Operations.Enter_Task
1962 (if not null) when a new task is created. It is initialized by
1963 System.Stack_Checking.Operations.Initialize_Stack_Limit.
1964 The use of a hook avoids to drag stack checking subprograms if stack
1965 checking is not used. */
1966 void (*__gnat_set_stack_limit_hook)(void) = (void (*)(void))0;
1968 /******************/
1969 /* NetBSD Section */
1970 /******************/
1972 #elif defined(__NetBSD__)
1978 __gnat_error_handler (int sig)
1980 struct Exception_Data *exception;
1986 exception = &constraint_error;
1990 exception = &constraint_error;
1994 exception = &storage_error;
1995 msg = "stack overflow or erroneous memory access";
1998 exception = &constraint_error;
2002 exception = &program_error;
2003 msg = "unhandled signal";
2006 Raise_From_Signal_Handler(exception, msg);
2010 __gnat_install_handler(void)
2012 struct sigaction act;
2014 act.sa_handler = __gnat_error_handler;
2015 act.sa_flags = SA_NODEFER | SA_RESTART;
2016 sigemptyset (&act.sa_mask);
2018 /* Do not install handlers if interrupt state is "System". */
2019 if (__gnat_get_interrupt_state (SIGFPE) != 's')
2020 sigaction (SIGFPE, &act, NULL);
2021 if (__gnat_get_interrupt_state (SIGILL) != 's')
2022 sigaction (SIGILL, &act, NULL);
2023 if (__gnat_get_interrupt_state (SIGSEGV) != 's')
2024 sigaction (SIGSEGV, &act, NULL);
2025 if (__gnat_get_interrupt_state (SIGBUS) != 's')
2026 sigaction (SIGBUS, &act, NULL);
2028 __gnat_handler_installed = 1;
2031 /*******************/
2032 /* OpenBSD Section */
2033 /*******************/
2035 #elif defined(__OpenBSD__)
2041 __gnat_error_handler (int sig)
2043 struct Exception_Data *exception;
2049 exception = &constraint_error;
2053 exception = &constraint_error;
2057 exception = &storage_error;
2058 msg = "stack overflow or erroneous memory access";
2061 exception = &constraint_error;
2065 exception = &program_error;
2066 msg = "unhandled signal";
2069 Raise_From_Signal_Handler(exception, msg);
2073 __gnat_install_handler(void)
2075 struct sigaction act;
2077 act.sa_handler = __gnat_error_handler;
2078 act.sa_flags = SA_NODEFER | SA_RESTART;
2079 sigemptyset (&act.sa_mask);
2081 /* Do not install handlers if interrupt state is "System" */
2082 if (__gnat_get_interrupt_state (SIGFPE) != 's')
2083 sigaction (SIGFPE, &act, NULL);
2084 if (__gnat_get_interrupt_state (SIGILL) != 's')
2085 sigaction (SIGILL, &act, NULL);
2086 if (__gnat_get_interrupt_state (SIGSEGV) != 's')
2087 sigaction (SIGSEGV, &act, NULL);
2088 if (__gnat_get_interrupt_state (SIGBUS) != 's')
2089 sigaction (SIGBUS, &act, NULL);
2091 __gnat_handler_installed = 1;
2094 /******************/
2095 /* Darwin Section */
2096 /******************/
2098 #elif defined(__APPLE__)
2101 #include <mach/mach_vm.h>
2102 #include <mach/vm_statistics.h>
2104 /* This must be in keeping with System.OS_Interface.Alternate_Stack_Size. */
2105 char __gnat_alternate_stack[64 * 1024]; /* 2 * MINSIGSTKSZ */
2107 static void __gnat_error_handler (int sig, siginfo_t * si, void * uc);
2109 /* Defined in xnu unix_signal.c */
2110 #define UC_RESET_ALT_STACK 0x80000000
2111 extern int sigreturn (void *uc, int flavour);
2113 /* Return true if ADDR is within a stack guard area. */
2115 __gnat_is_stack_guard (mach_vm_address_t addr)
2118 vm_region_submap_info_data_64_t info;
2119 mach_vm_address_t start;
2120 mach_vm_size_t size;
2122 mach_msg_type_number_t count;
2124 count = VM_REGION_SUBMAP_INFO_COUNT_64;
2128 kret = mach_vm_region_recurse (mach_task_self (), &start, &size, &depth,
2129 (vm_region_recurse_info_t) &info, &count);
2130 if (kret == KERN_SUCCESS
2131 && addr >= start && addr < (start + size)
2132 && info.protection == VM_PROT_NONE
2133 && info.user_tag == VM_MEMORY_STACK)
2139 __gnat_error_handler (int sig, siginfo_t * si, void * uc)
2141 struct Exception_Data *exception;
2148 if (__gnat_is_stack_guard ((unsigned long)si->si_addr))
2150 exception = &storage_error;
2151 msg = "stack overflow";
2155 exception = &constraint_error;
2156 msg = "erroneous memory access";
2158 /* Reset the use of alt stack, so that the alt stack will be used
2159 for the next signal delivery. */
2160 sigreturn (NULL, UC_RESET_ALT_STACK);
2164 exception = &constraint_error;
2169 exception = &program_error;
2170 msg = "unhandled signal";
2173 Raise_From_Signal_Handler (exception, msg);
2177 __gnat_install_handler (void)
2179 struct sigaction act;
2181 /* Set up signal handler to map synchronous signals to appropriate
2182 exceptions. Make sure that the handler isn't interrupted by another
2183 signal that might cause a scheduling event! Also setup an alternate
2184 stack region for the handler execution so that stack overflows can be
2185 handled properly, avoiding a SEGV generation from stack usage by the
2186 handler itself (and it is required by Darwin). */
2189 stack.ss_sp = __gnat_alternate_stack;
2190 stack.ss_size = sizeof (__gnat_alternate_stack);
2192 sigaltstack (&stack, NULL);
2194 act.sa_flags = SA_NODEFER | SA_RESTART | SA_SIGINFO;
2195 act.sa_sigaction = __gnat_error_handler;
2196 sigemptyset (&act.sa_mask);
2198 /* Do not install handlers if interrupt state is "System". */
2199 if (__gnat_get_interrupt_state (SIGABRT) != 's')
2200 sigaction (SIGABRT, &act, NULL);
2201 if (__gnat_get_interrupt_state (SIGFPE) != 's')
2202 sigaction (SIGFPE, &act, NULL);
2203 if (__gnat_get_interrupt_state (SIGILL) != 's')
2204 sigaction (SIGILL, &act, NULL);
2206 act.sa_flags |= SA_ONSTACK;
2207 if (__gnat_get_interrupt_state (SIGSEGV) != 's')
2208 sigaction (SIGSEGV, &act, NULL);
2209 if (__gnat_get_interrupt_state (SIGBUS) != 's')
2210 sigaction (SIGBUS, &act, NULL);
2212 __gnat_handler_installed = 1;
2217 /* For all other versions of GNAT, the handler does nothing. */
2219 /*******************/
2220 /* Default Section */
2221 /*******************/
2224 __gnat_install_handler (void)
2226 __gnat_handler_installed = 1;
2231 /*********************/
2232 /* __gnat_init_float */
2233 /*********************/
2235 /* This routine is called as each process thread is created, for possible
2236 initialization of the FP processor. This version is used under INTERIX,
2237 WIN32 and could be used under OS/2. */
2239 #if defined (_WIN32) || defined (__INTERIX) || defined (__EMX__) \
2240 || defined (__Lynx__) || defined(__NetBSD__) || defined(__FreeBSD__) \
2241 || defined (__OpenBSD__)
2243 #define HAVE_GNAT_INIT_FLOAT
2246 __gnat_init_float (void)
2248 #if defined (__i386__) || defined (i386) || defined (__x86_64)
2250 /* This is used to properly initialize the FPU on an x86 for each
2255 #endif /* Defined __i386__ */
2259 #ifndef HAVE_GNAT_INIT_FLOAT
2261 /* All targets without a specific __gnat_init_float will use an empty one. */
2263 __gnat_init_float (void)
2268 /***********************************/
2269 /* __gnat_adjust_context_for_raise */
2270 /***********************************/
2272 #ifndef HAVE_GNAT_ADJUST_CONTEXT_FOR_RAISE
2274 /* All targets without a specific version will use an empty one. */
2276 /* Given UCONTEXT a pointer to a context structure received by a signal
2277 handler for SIGNO, perform the necessary adjustments to let the handler
2278 raise an exception. Calls to this routine are not conditioned by the
2279 propagation scheme in use. */
2282 __gnat_adjust_context_for_raise (int signo ATTRIBUTE_UNUSED,
2283 void *ucontext ATTRIBUTE_UNUSED)
2285 /* We used to compensate here for the raised from call vs raised from signal
2286 exception discrepancy with the GCC ZCX scheme, but this now can be dealt
2287 with generically in the unwinder (see GCC PR other/26208). Only the VMS
2288 ports still do the compensation described in the few lines below.
2290 *** Call vs signal exception discrepancy with GCC ZCX scheme ***
2292 The GCC unwinder expects to be dealing with call return addresses, since
2293 this is the "nominal" case of what we retrieve while unwinding a regular
2296 To evaluate if a handler applies at some point identified by a return
2297 address, the propagation engine needs to determine what region the
2298 corresponding call instruction pertains to. Because the return address
2299 may not be attached to the same region as the call, the unwinder always
2300 subtracts "some" amount from a return address to search the region
2301 tables, amount chosen to ensure that the resulting address is inside the
2304 When we raise an exception from a signal handler, e.g. to transform a
2305 SIGSEGV into Storage_Error, things need to appear as if the signal
2306 handler had been "called" by the instruction which triggered the signal,
2307 so that exception handlers that apply there are considered. What the
2308 unwinder will retrieve as the return address from the signal handler is
2309 what it will find as the faulting instruction address in the signal
2310 context pushed by the kernel. Leaving this address untouched looses, if
2311 the triggering instruction happens to be the very first of a region, as
2312 the later adjustments performed by the unwinder would yield an address
2313 outside that region. We need to compensate for the unwinder adjustments
2314 at some point, and this is what this routine is expected to do.
2316 signo is passed because on some targets for some signals the PC in
2317 context points to the instruction after the faulting one, in which case
2318 the unwinder adjustment is still desired. */