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 us 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, in order to make sure that it points to an accessible
596 address in case it's used as the target CFA. The stack checking code
597 guarantees that this page is unused by the time this happens. */
600 unsigned long pattern = *(unsigned long *)mcontext->gregs[REG_EIP];
601 /* The pattern is "orl $0x0,(%esp)" for a probe in 32-bit mode. */
602 if (signo == SIGSEGV && pattern == 0x00240c83)
603 mcontext->gregs[REG_ESP] += 4096;
604 #elif defined (__x86_64__)
605 unsigned long pattern = *(unsigned long *)mcontext->gregs[REG_RIP];
606 /* The pattern is "orq $0x0,(%rsp)" for a probe in 64-bit mode. */
607 if (signo == SIGSEGV && (pattern & 0xffffffffff) == 0x00240c8348)
608 mcontext->gregs[REG_RSP] += 4096;
609 #elif defined (__ia64__)
610 /* ??? The IA-64 unwinder doesn't compensate for signals. */
618 __gnat_error_handler (int sig,
619 siginfo_t *siginfo ATTRIBUTE_UNUSED,
622 struct Exception_Data *exception;
624 static int recurse = 0;
629 /* If the problem was permissions, this is a constraint error.
630 Likewise if the failing address isn't maximally aligned or if
633 ??? Using a static variable here isn't task-safe, but it's
634 much too hard to do anything else and we're just determining
635 which exception to raise. */
638 exception = &constraint_error;
643 /* Here we would like a discrimination test to see whether the
644 page before the faulting address is accessible. Unfortunately
645 Linux seems to have no way of giving us the faulting address.
647 In versions of a-init.c before 1.95, we had a test of the page
648 before the stack pointer using:
652 ((long) info->esp_at_signal & - getpagesize ()))[getpagesize ()];
654 but that's wrong, since it tests the stack pointer location, and
655 the current stack probe code does not move the stack pointer
656 until all probes succeed.
658 For now we simply do not attempt any discrimination at all. Note
659 that this is quite acceptable, since a "real" SIGSEGV can only
660 occur as the result of an erroneous program. */
662 msg = "stack overflow (or erroneous memory access)";
663 exception = &storage_error;
668 exception = &constraint_error;
673 exception = &constraint_error;
678 exception = &program_error;
679 msg = "unhandled signal";
683 /* We adjust the interrupted context here (and not in the fallback
684 unwinding routine) because recent versions of the Native POSIX
685 Thread Library (NPTL) are compiled with unwind information, so
686 the fallback routine is never executed for signal frames. */
687 __gnat_adjust_context_for_raise (sig, ucontext);
689 Raise_From_Signal_Handler (exception, msg);
692 #if defined (i386) || defined (__x86_64__)
693 /* This must be in keeping with System.OS_Interface.Alternate_Stack_Size. */
694 char __gnat_alternate_stack[16 * 1024]; /* 2 * SIGSTKSZ */
698 #include <sys/mman.h>
699 #include <native/task.h>
705 __gnat_install_handler (void)
707 struct sigaction act;
712 if (__gl_main_priority == -1)
715 prio = __gl_main_priority;
717 /* Avoid memory swapping for this program */
719 mlockall (MCL_CURRENT|MCL_FUTURE);
721 /* Turn the current Linux task into a native Xenomai task */
723 rt_task_shadow(&main_task, "environment_task", prio, T_FPU);
726 /* Set up signal handler to map synchronous signals to appropriate
727 exceptions. Make sure that the handler isn't interrupted by another
728 signal that might cause a scheduling event! Also setup an alternate
729 stack region for the handler execution so that stack overflows can be
730 handled properly, avoiding a SEGV generation from stack usage by the
733 #if defined (i386) || defined (__x86_64__)
735 stack.ss_sp = __gnat_alternate_stack;
736 stack.ss_size = sizeof (__gnat_alternate_stack);
738 sigaltstack (&stack, NULL);
741 act.sa_sigaction = __gnat_error_handler;
742 act.sa_flags = SA_NODEFER | SA_RESTART | SA_SIGINFO;
743 sigemptyset (&act.sa_mask);
745 /* Do not install handlers if interrupt state is "System". */
746 if (__gnat_get_interrupt_state (SIGABRT) != 's')
747 sigaction (SIGABRT, &act, NULL);
748 if (__gnat_get_interrupt_state (SIGFPE) != 's')
749 sigaction (SIGFPE, &act, NULL);
750 if (__gnat_get_interrupt_state (SIGILL) != 's')
751 sigaction (SIGILL, &act, NULL);
752 if (__gnat_get_interrupt_state (SIGBUS) != 's')
753 sigaction (SIGBUS, &act, NULL);
754 #if defined (i386) || defined (__x86_64__)
755 act.sa_flags |= SA_ONSTACK;
757 if (__gnat_get_interrupt_state (SIGSEGV) != 's')
758 sigaction (SIGSEGV, &act, NULL);
760 __gnat_handler_installed = 1;
776 #define SIGADAABORT 48
777 #define SIGNAL_STACK_SIZE 4096
778 #define SIGNAL_STACK_ALIGNMENT 64
780 #define Check_Abort_Status \
781 system__soft_links__check_abort_status
782 extern int (*Check_Abort_Status) (void);
784 extern struct Exception_Data _abort_signal;
786 static void __gnat_error_handler (int, int, sigcontext_t *);
788 /* We are not setting the SA_SIGINFO bit in the sigaction flags when
789 connecting that handler, with the effects described in the sigaction
793 If cleared and the signal is caught, the first argument is
794 also the signal number but the second argument is the signal
795 code identifying the cause of the signal. The third argument
796 points to a sigcontext_t structure containing the receiving
797 process's context when the signal was delivered. */
800 __gnat_error_handler (int sig, int code, sigcontext_t *sc ATTRIBUTE_UNUSED)
802 struct Exception_Data *exception;
810 exception = &program_error;
811 msg = "SIGSEGV: (Invalid virtual address)";
813 else if (code == ENXIO)
815 exception = &program_error;
816 msg = "SIGSEGV: (Read beyond mapped object)";
818 else if (code == ENOSPC)
820 exception = &program_error; /* ??? storage_error ??? */
821 msg = "SIGSEGV: (Autogrow for file failed)";
823 else if (code == EACCES || code == EEXIST)
825 /* ??? We handle stack overflows here, some of which do trigger
826 SIGSEGV + EEXIST on Irix 6.5 although EEXIST is not part of
827 the documented valid codes for SEGV in the signal(5) man
830 /* ??? Re-add smarts to further verify that we launched
831 the stack into a guard page, not an attempt to
832 write to .text or something. */
833 exception = &storage_error;
834 msg = "SIGSEGV: (stack overflow or erroneous memory access)";
838 /* Just in case the OS guys did it to us again. Sometimes
839 they fail to document all of the valid codes that are
840 passed to signal handlers, just in case someone depends
841 on knowing all the codes. */
842 exception = &program_error;
843 msg = "SIGSEGV: (Undocumented reason)";
848 /* Map all bus errors to Program_Error. */
849 exception = &program_error;
854 /* Map all fpe errors to Constraint_Error. */
855 exception = &constraint_error;
860 if ((*Check_Abort_Status) ())
862 exception = &_abort_signal;
871 /* Everything else is a Program_Error. */
872 exception = &program_error;
873 msg = "unhandled signal";
876 Raise_From_Signal_Handler (exception, msg);
880 __gnat_install_handler (void)
882 struct sigaction act;
884 /* Setup signal handler to map synchronous signals to appropriate
885 exceptions. Make sure that the handler isn't interrupted by another
886 signal that might cause a scheduling event! */
888 act.sa_handler = __gnat_error_handler;
889 act.sa_flags = SA_NODEFER + SA_RESTART;
890 sigfillset (&act.sa_mask);
891 sigemptyset (&act.sa_mask);
893 /* Do not install handlers if interrupt state is "System". */
894 if (__gnat_get_interrupt_state (SIGABRT) != 's')
895 sigaction (SIGABRT, &act, NULL);
896 if (__gnat_get_interrupt_state (SIGFPE) != 's')
897 sigaction (SIGFPE, &act, NULL);
898 if (__gnat_get_interrupt_state (SIGILL) != 's')
899 sigaction (SIGILL, &act, NULL);
900 if (__gnat_get_interrupt_state (SIGSEGV) != 's')
901 sigaction (SIGSEGV, &act, NULL);
902 if (__gnat_get_interrupt_state (SIGBUS) != 's')
903 sigaction (SIGBUS, &act, NULL);
904 if (__gnat_get_interrupt_state (SIGADAABORT) != 's')
905 sigaction (SIGADAABORT, &act, NULL);
907 __gnat_handler_installed = 1;
910 /*******************/
912 /*******************/
914 #elif defined (__Lynx__)
920 __gnat_error_handler (int sig)
922 struct Exception_Data *exception;
928 exception = &constraint_error;
932 exception = &constraint_error;
936 exception = &storage_error;
937 msg = "stack overflow or erroneous memory access";
940 exception = &constraint_error;
944 exception = &program_error;
945 msg = "unhandled signal";
948 Raise_From_Signal_Handler(exception, msg);
952 __gnat_install_handler(void)
954 struct sigaction act;
956 act.sa_handler = __gnat_error_handler;
958 sigemptyset (&act.sa_mask);
960 /* Do not install handlers if interrupt state is "System". */
961 if (__gnat_get_interrupt_state (SIGFPE) != 's')
962 sigaction (SIGFPE, &act, NULL);
963 if (__gnat_get_interrupt_state (SIGILL) != 's')
964 sigaction (SIGILL, &act, NULL);
965 if (__gnat_get_interrupt_state (SIGSEGV) != 's')
966 sigaction (SIGSEGV, &act, NULL);
967 if (__gnat_get_interrupt_state (SIGBUS) != 's')
968 sigaction (SIGBUS, &act, NULL);
970 __gnat_handler_installed = 1;
973 /*******************/
974 /* Solaris Section */
975 /*******************/
977 #elif defined (sun) && defined (__SVR4) && !defined (__vxworks)
981 #include <sys/ucontext.h>
982 #include <sys/regset.h>
984 /* The code below is common to SPARC and x86. Beware of the delay slot
985 differences for signal context adjustments. */
987 #if defined (__sparc)
988 #define RETURN_ADDR_OFFSET 8
990 #define RETURN_ADDR_OFFSET 0
993 /* Likewise regarding how the "instruction pointer" register slot can
994 be identified in signal machine contexts. We have either "REG_PC"
995 or "PC" at hand, depending on the target CPU and Solaris version. */
997 #if !defined (REG_PC)
1001 static void __gnat_error_handler (int, siginfo_t *, ucontext_t *);
1004 __gnat_error_handler (int sig, siginfo_t *sip, ucontext_t *uctx)
1006 struct Exception_Data *exception;
1007 static int recurse = 0;
1010 /* If this was an explicit signal from a "kill", just resignal it. */
1011 if (SI_FROMUSER (sip))
1013 signal (sig, SIG_DFL);
1014 kill (getpid(), sig);
1017 /* Otherwise, treat it as something we handle. */
1021 /* If the problem was permissions, this is a constraint error.
1022 Likewise if the failing address isn't maximally aligned or if
1025 ??? Using a static variable here isn't task-safe, but it's
1026 much too hard to do anything else and we're just determining
1027 which exception to raise. */
1028 if (sip->si_code == SEGV_ACCERR
1029 || (((long) sip->si_addr) & 3) != 0
1032 exception = &constraint_error;
1037 /* See if the page before the faulting page is accessible. Do that
1038 by trying to access it. We'd like to simply try to access
1039 4096 + the faulting address, but it's not guaranteed to be
1040 the actual address, just to be on the same page. */
1043 ((long) sip->si_addr & - getpagesize ()))[getpagesize ()];
1044 exception = &storage_error;
1045 msg = "stack overflow (or erroneous memory access)";
1050 exception = &program_error;
1055 exception = &constraint_error;
1060 exception = &program_error;
1061 msg = "unhandled signal";
1066 Raise_From_Signal_Handler (exception, msg);
1070 __gnat_install_handler (void)
1072 struct sigaction act;
1074 /* Set up signal handler to map synchronous signals to appropriate
1075 exceptions. Make sure that the handler isn't interrupted by another
1076 signal that might cause a scheduling event! */
1078 act.sa_handler = __gnat_error_handler;
1079 act.sa_flags = SA_NODEFER | SA_RESTART | SA_SIGINFO;
1080 sigemptyset (&act.sa_mask);
1082 /* Do not install handlers if interrupt state is "System". */
1083 if (__gnat_get_interrupt_state (SIGABRT) != 's')
1084 sigaction (SIGABRT, &act, NULL);
1085 if (__gnat_get_interrupt_state (SIGFPE) != 's')
1086 sigaction (SIGFPE, &act, NULL);
1087 if (__gnat_get_interrupt_state (SIGSEGV) != 's')
1088 sigaction (SIGSEGV, &act, NULL);
1089 if (__gnat_get_interrupt_state (SIGBUS) != 's')
1090 sigaction (SIGBUS, &act, NULL);
1092 __gnat_handler_installed = 1;
1101 /* Routine called from binder to override default feature values. */
1102 void __gnat_set_features ();
1103 int __gnat_features_set = 0;
1105 long __gnat_error_handler (int *, void *);
1108 #define lib_get_curr_invo_context LIB$I64_GET_CURR_INVO_CONTEXT
1109 #define lib_get_prev_invo_context LIB$I64_GET_PREV_INVO_CONTEXT
1110 #define lib_get_invo_handle LIB$I64_GET_INVO_HANDLE
1112 #define lib_get_curr_invo_context LIB$GET_CURR_INVO_CONTEXT
1113 #define lib_get_prev_invo_context LIB$GET_PREV_INVO_CONTEXT
1114 #define lib_get_invo_handle LIB$GET_INVO_HANDLE
1117 #if defined (IN_RTS) && !defined (__IA64)
1119 /* The prehandler actually gets control first on a condition. It swaps the
1120 stack pointer and calls the handler (__gnat_error_handler). */
1121 extern long __gnat_error_prehandler (void);
1123 extern char *__gnat_error_prehandler_stack; /* Alternate signal stack */
1126 /* Define macro symbols for the VMS conditions that become Ada exceptions.
1127 Most of these are also defined in the header file ssdef.h which has not
1128 yet been converted to be recognized by GNU C. */
1130 /* Defining these as macros, as opposed to external addresses, allows
1131 them to be used in a case statement below. */
1132 #define SS$_ACCVIO 12
1133 #define SS$_HPARITH 1284
1134 #define SS$_STKOVF 1364
1135 #define SS$_RESIGNAL 2328
1137 /* These codes are in standard message libraries. */
1138 extern int CMA$_EXIT_THREAD;
1139 extern int SS$_DEBUG;
1140 extern int SS$_INTDIV;
1141 extern int LIB$_KEYNOTFOU;
1142 extern int LIB$_ACTIMAGE;
1143 extern int MTH$_FLOOVEMAT; /* Some ACVC_21 CXA tests */
1145 /* These codes are non standard, which is to say the author is
1146 not sure if they are defined in the standard message libraries
1147 so keep them as macros for now. */
1148 #define RDB$_STREAM_EOF 20480426
1149 #define FDL$_UNPRIKW 11829410
1151 struct cond_except {
1153 const struct Exception_Data *except;
1156 struct descriptor_s {unsigned short len, mbz; __char_ptr32 adr; };
1158 /* Conditions that don't have an Ada exception counterpart must raise
1159 Non_Ada_Error. Since this is defined in s-auxdec, it should only be
1160 referenced by user programs, not the compiler or tools. Hence the
1165 #define Status_Error ada__io_exceptions__status_error
1166 extern struct Exception_Data Status_Error;
1168 #define Mode_Error ada__io_exceptions__mode_error
1169 extern struct Exception_Data Mode_Error;
1171 #define Name_Error ada__io_exceptions__name_error
1172 extern struct Exception_Data Name_Error;
1174 #define Use_Error ada__io_exceptions__use_error
1175 extern struct Exception_Data Use_Error;
1177 #define Device_Error ada__io_exceptions__device_error
1178 extern struct Exception_Data Device_Error;
1180 #define End_Error ada__io_exceptions__end_error
1181 extern struct Exception_Data End_Error;
1183 #define Data_Error ada__io_exceptions__data_error
1184 extern struct Exception_Data Data_Error;
1186 #define Layout_Error ada__io_exceptions__layout_error
1187 extern struct Exception_Data Layout_Error;
1189 #define Non_Ada_Error system__aux_dec__non_ada_error
1190 extern struct Exception_Data Non_Ada_Error;
1192 #define Coded_Exception system__vms_exception_table__coded_exception
1193 extern struct Exception_Data *Coded_Exception (Exception_Code);
1195 #define Base_Code_In system__vms_exception_table__base_code_in
1196 extern Exception_Code Base_Code_In (Exception_Code);
1198 /* DEC Ada exceptions are not defined in a header file, so they
1199 must be declared as external addresses. */
1201 extern int ADA$_PROGRAM_ERROR;
1202 extern int ADA$_LOCK_ERROR;
1203 extern int ADA$_EXISTENCE_ERROR;
1204 extern int ADA$_KEY_ERROR;
1205 extern int ADA$_KEYSIZERR;
1206 extern int ADA$_STAOVF;
1207 extern int ADA$_CONSTRAINT_ERRO;
1208 extern int ADA$_IOSYSFAILED;
1209 extern int ADA$_LAYOUT_ERROR;
1210 extern int ADA$_STORAGE_ERROR;
1211 extern int ADA$_DATA_ERROR;
1212 extern int ADA$_DEVICE_ERROR;
1213 extern int ADA$_END_ERROR;
1214 extern int ADA$_MODE_ERROR;
1215 extern int ADA$_NAME_ERROR;
1216 extern int ADA$_STATUS_ERROR;
1217 extern int ADA$_NOT_OPEN;
1218 extern int ADA$_ALREADY_OPEN;
1219 extern int ADA$_USE_ERROR;
1220 extern int ADA$_UNSUPPORTED;
1221 extern int ADA$_FAC_MODE_MISMAT;
1222 extern int ADA$_ORG_MISMATCH;
1223 extern int ADA$_RFM_MISMATCH;
1224 extern int ADA$_RAT_MISMATCH;
1225 extern int ADA$_MRS_MISMATCH;
1226 extern int ADA$_MRN_MISMATCH;
1227 extern int ADA$_KEY_MISMATCH;
1228 extern int ADA$_MAXLINEXC;
1229 extern int ADA$_LINEXCMRS;
1231 /* DEC Ada specific conditions. */
1232 static const struct cond_except dec_ada_cond_except_table [] = {
1233 {&ADA$_PROGRAM_ERROR, &program_error},
1234 {&ADA$_USE_ERROR, &Use_Error},
1235 {&ADA$_KEYSIZERR, &program_error},
1236 {&ADA$_STAOVF, &storage_error},
1237 {&ADA$_CONSTRAINT_ERRO, &constraint_error},
1238 {&ADA$_IOSYSFAILED, &Device_Error},
1239 {&ADA$_LAYOUT_ERROR, &Layout_Error},
1240 {&ADA$_STORAGE_ERROR, &storage_error},
1241 {&ADA$_DATA_ERROR, &Data_Error},
1242 {&ADA$_DEVICE_ERROR, &Device_Error},
1243 {&ADA$_END_ERROR, &End_Error},
1244 {&ADA$_MODE_ERROR, &Mode_Error},
1245 {&ADA$_NAME_ERROR, &Name_Error},
1246 {&ADA$_STATUS_ERROR, &Status_Error},
1247 {&ADA$_NOT_OPEN, &Use_Error},
1248 {&ADA$_ALREADY_OPEN, &Use_Error},
1249 {&ADA$_USE_ERROR, &Use_Error},
1250 {&ADA$_UNSUPPORTED, &Use_Error},
1251 {&ADA$_FAC_MODE_MISMAT, &Use_Error},
1252 {&ADA$_ORG_MISMATCH, &Use_Error},
1253 {&ADA$_RFM_MISMATCH, &Use_Error},
1254 {&ADA$_RAT_MISMATCH, &Use_Error},
1255 {&ADA$_MRS_MISMATCH, &Use_Error},
1256 {&ADA$_MRN_MISMATCH, &Use_Error},
1257 {&ADA$_KEY_MISMATCH, &Use_Error},
1258 {&ADA$_MAXLINEXC, &constraint_error},
1259 {&ADA$_LINEXCMRS, &constraint_error},
1264 /* Already handled by a pragma Import_Exception
1265 in Aux_IO_Exceptions */
1266 {&ADA$_LOCK_ERROR, &Lock_Error},
1267 {&ADA$_EXISTENCE_ERROR, &Existence_Error},
1268 {&ADA$_KEY_ERROR, &Key_Error},
1273 /* Non-DEC Ada specific conditions. We could probably also put
1274 SS$_HPARITH here and possibly SS$_ACCVIO, SS$_STKOVF. */
1275 static const struct cond_except cond_except_table [] = {
1276 {&MTH$_FLOOVEMAT, &constraint_error},
1277 {&SS$_INTDIV, &constraint_error},
1281 /* To deal with VMS conditions and their mapping to Ada exceptions,
1282 the __gnat_error_handler routine below is installed as an exception
1283 vector having precedence over DEC frame handlers. Some conditions
1284 still need to be handled by such handlers, however, in which case
1285 __gnat_error_handler needs to return SS$_RESIGNAL. Consider for
1286 instance the use of a third party library compiled with DECAda and
1287 performing its own exception handling internally.
1289 To allow some user-level flexibility, which conditions should be
1290 resignaled is controlled by a predicate function, provided with the
1291 condition value and returning a boolean indication stating whether
1292 this condition should be resignaled or not.
1294 That predicate function is called indirectly, via a function pointer,
1295 by __gnat_error_handler, and changing that pointer is allowed to the
1296 the user code by way of the __gnat_set_resignal_predicate interface.
1298 The user level function may then implement what it likes, including
1299 for instance the maintenance of a dynamic data structure if the set
1300 of to be resignalled conditions has to change over the program's
1303 ??? This is not a perfect solution to deal with the possible
1304 interactions between the GNAT and the DECAda exception handling
1305 models and better (more general) schemes are studied. This is so
1306 just provided as a convenient workaround in the meantime, and
1307 should be use with caution since the implementation has been kept
1311 resignal_predicate (int code);
1313 const int *cond_resignal_table [] = {
1318 (int *) RDB$_STREAM_EOF,
1319 (int *) FDL$_UNPRIKW,
1323 const int facility_resignal_table [] = {
1324 0x1380000, /* RDB */
1325 0x2220000, /* SQL */
1329 /* Default GNAT predicate for resignaling conditions. */
1332 __gnat_default_resignal_p (int code)
1336 for (i = 0; facility_resignal_table [i]; i++)
1337 if ((code & 0xfff0000) == facility_resignal_table [i])
1340 for (i = 0, iexcept = 0;
1341 cond_resignal_table [i] &&
1342 !(iexcept = LIB$MATCH_COND (&code, &cond_resignal_table [i]));
1348 /* Static pointer to predicate that the __gnat_error_handler exception
1349 vector invokes to determine if it should resignal a condition. */
1351 static resignal_predicate * __gnat_resignal_p = __gnat_default_resignal_p;
1353 /* User interface to change the predicate pointer to PREDICATE. Reset to
1354 the default if PREDICATE is null. */
1357 __gnat_set_resignal_predicate (resignal_predicate * predicate)
1360 __gnat_resignal_p = __gnat_default_resignal_p;
1362 __gnat_resignal_p = predicate;
1365 /* Should match System.Parameters.Default_Exception_Msg_Max_Length. */
1366 #define Default_Exception_Msg_Max_Length 512
1368 /* Action routine for SYS$PUTMSG. There may be multiple
1369 conditions, each with text to be appended to MESSAGE
1370 and separated by line termination. */
1373 copy_msg (msgdesc, message)
1374 struct descriptor_s *msgdesc;
1377 int len = strlen (message);
1380 /* Check for buffer overflow and skip. */
1381 if (len > 0 && len <= Default_Exception_Msg_Max_Length - 3)
1383 strcat (message, "\r\n");
1387 /* Check for buffer overflow and truncate if necessary. */
1388 copy_len = (len + msgdesc->len <= Default_Exception_Msg_Max_Length - 1 ?
1390 Default_Exception_Msg_Max_Length - 1 - len);
1391 strncpy (&message [len], msgdesc->adr, copy_len);
1392 message [len + copy_len] = 0;
1398 __gnat_handle_vms_condition (int *sigargs, void *mechargs)
1400 struct Exception_Data *exception = 0;
1401 Exception_Code base_code;
1402 struct descriptor_s gnat_facility = {4,0,"GNAT"};
1403 char message [Default_Exception_Msg_Max_Length];
1405 const char *msg = "";
1407 /* Check for conditions to resignal which aren't effected by pragma
1408 Import_Exception. */
1409 if (__gnat_resignal_p (sigargs [1]))
1410 return SS$_RESIGNAL;
1413 /* See if it's an imported exception. Beware that registered exceptions
1414 are bound to their base code, with the severity bits masked off. */
1415 base_code = Base_Code_In ((Exception_Code) sigargs [1]);
1416 exception = Coded_Exception (base_code);
1422 /* Subtract PC & PSL fields which messes with PUTMSG. */
1424 SYS$PUTMSG (sigargs, copy_msg, &gnat_facility, message);
1428 exception->Name_Length = 19;
1429 /* ??? The full name really should be get sys$getmsg returns. */
1430 exception->Full_Name = "IMPORTED_EXCEPTION";
1431 exception->Import_Code = base_code;
1434 /* Do not adjust the program counter as already points to the next
1435 instruction (just after the call to LIB$STOP). */
1436 Raise_From_Signal_Handler (exception, msg);
1445 if (sigargs[3] == 0)
1447 exception = &constraint_error;
1448 msg = "access zero";
1452 exception = &storage_error;
1453 msg = "stack overflow (or erroneous memory access)";
1455 __gnat_adjust_context_for_raise (0, (void *)mechargs);
1459 exception = &storage_error;
1460 msg = "stack overflow";
1461 __gnat_adjust_context_for_raise (0, (void *)mechargs);
1466 return SS$_RESIGNAL; /* toplev.c handles for compiler */
1468 exception = &constraint_error;
1469 msg = "arithmetic error";
1471 /* No need to adjust pc on Alpha: the pc is already on the instruction
1472 after the trapping one. */
1473 __gnat_adjust_context_for_raise (0, (void *)mechargs);
1483 /* Scan the DEC Ada exception condition table for a match and fetch
1484 the associated GNAT exception pointer. */
1486 dec_ada_cond_except_table [i].cond &&
1487 !LIB$MATCH_COND (&sigargs [1],
1488 &dec_ada_cond_except_table [i].cond);
1490 exception = (struct Exception_Data *)
1491 dec_ada_cond_except_table [i].except;
1495 /* Scan the VMS standard condition table for a match and fetch
1496 the associated GNAT exception pointer. */
1498 cond_except_table [i].cond &&
1499 !LIB$MATCH_COND (&sigargs [1], &cond_except_table [i].cond);
1501 exception = (struct Exception_Data *)
1502 cond_except_table [i].except;
1505 /* User programs expect Non_Ada_Error to be raised, reference
1506 DEC Ada test CXCONDHAN. */
1507 exception = &Non_Ada_Error;
1511 exception = &program_error;
1514 /* Subtract PC & PSL fields which messes with PUTMSG. */
1516 SYS$PUTMSG (sigargs, copy_msg, &gnat_facility, message);
1522 Raise_From_Signal_Handler (exception, msg);
1526 __gnat_error_handler (int *sigargs, void *mechargs)
1528 return __gnat_handle_vms_condition (sigargs, mechargs);
1532 __gnat_install_handler (void)
1534 long prvhnd ATTRIBUTE_UNUSED;
1536 #if !defined (IN_RTS)
1537 SYS$SETEXV (1, __gnat_error_handler, 3, &prvhnd);
1540 /* On alpha-vms, we avoid the global vector annoyance thanks to frame based
1541 handlers to turn conditions into exceptions since GCC 3.4. The global
1542 vector is still required for earlier GCC versions. We're resorting to
1543 the __gnat_error_prehandler assembly function in this case. */
1545 #if defined (IN_RTS) && defined (__alpha__)
1546 if ((__GNUC__ * 10 + __GNUC_MINOR__) < 34)
1548 char * c = (char *) xmalloc (2049);
1550 __gnat_error_prehandler_stack = &c[2048];
1551 SYS$SETEXV (1, __gnat_error_prehandler, 3, &prvhnd);
1555 __gnat_handler_installed = 1;
1558 /* __gnat_adjust_context_for_raise for Alpha - see comments along with the
1559 default version later in this file. */
1561 #if defined (IN_RTS) && defined (__alpha__)
1563 #include <vms/chfctxdef.h>
1564 #include <vms/chfdef.h>
1566 #define HAVE_GNAT_ADJUST_CONTEXT_FOR_RAISE
1569 __gnat_adjust_context_for_raise (int signo ATTRIBUTE_UNUSED, void *ucontext)
1571 /* Add one to the address of the instruction signaling the condition,
1572 located in the sigargs array. */
1574 CHF$MECH_ARRAY * mechargs = (CHF$MECH_ARRAY *) ucontext;
1575 CHF$SIGNAL_ARRAY * sigargs
1576 = (CHF$SIGNAL_ARRAY *) mechargs->chf$q_mch_sig_addr;
1578 int vcount = sigargs->chf$is_sig_args;
1579 int * pc_slot = & (&sigargs->chf$l_sig_name)[vcount-2];
1586 /* __gnat_adjust_context_for_raise for ia64. */
1588 #if defined (IN_RTS) && defined (__IA64)
1590 #include <vms/chfctxdef.h>
1591 #include <vms/chfdef.h>
1593 #define HAVE_GNAT_ADJUST_CONTEXT_FOR_RAISE
1595 typedef unsigned long long u64;
1598 __gnat_adjust_context_for_raise (int signo ATTRIBUTE_UNUSED, void *ucontext)
1600 /* Add one to the address of the instruction signaling the condition,
1601 located in the 64bits sigargs array. */
1603 CHF$MECH_ARRAY * mechargs = (CHF$MECH_ARRAY *) ucontext;
1605 CHF64$SIGNAL_ARRAY *chfsig64
1606 = (CHF64$SIGNAL_ARRAY *) mechargs->chf$ph_mch_sig64_addr;
1609 = (u64 *)chfsig64 + 1 + chfsig64->chf64$l_sig_args;
1611 u64 * ih_pc_loc = post_sigarray - 2;
1618 /* Feature logical name and global variable address pair */
1619 struct feature {char *name; int* gl_addr;};
1621 /* Default values for GNAT features set by environment. */
1622 int __gl_no_malloc_64 = 0;
1624 /* Array feature logical names and global variable addresses */
1625 static struct feature features[] = {
1626 {"GNAT$NO_MALLOC_64", &__gl_no_malloc_64},
1630 void __gnat_set_features ()
1632 struct descriptor_s name_desc, result_desc;
1634 unsigned short rlen;
1637 char buff [MAXEQUIV];
1639 /* Loop through features array and test name for enable/disable */
1640 for (i=0; features [i].name; i++)
1642 name_desc.len = strlen (features [i].name);
1644 name_desc.adr = features [i].name;
1646 result_desc.len = MAXEQUIV - 1;
1647 result_desc.mbz = 0;
1648 result_desc.adr = buff;
1650 status = LIB$GET_LOGICAL (&name_desc, &result_desc, &rlen);
1652 if (((status & 1) == 1) && (rlen < MAXEQUIV))
1657 if (strcmp (buff, "ENABLE") == 0)
1658 *features [i].gl_addr = 1;
1659 else if (strcmp (buff, "DISABLE") == 0)
1660 *features [i].gl_addr = 0;
1663 __gnat_features_set = 1;
1666 /*******************/
1667 /* FreeBSD Section */
1668 /*******************/
1670 #elif defined (__FreeBSD__)
1673 #include <sys/ucontext.h>
1676 static void __gnat_error_handler (int, siginfo_t *, ucontext_t *);
1679 __gnat_error_handler (int sig, siginfo_t *info __attribute__ ((unused)),
1680 ucontext_t *ucontext)
1682 struct Exception_Data *exception;
1688 exception = &constraint_error;
1693 exception = &constraint_error;
1698 exception = &storage_error;
1699 msg = "stack overflow or erroneous memory access";
1703 exception = &constraint_error;
1708 exception = &program_error;
1709 msg = "unhandled signal";
1712 Raise_From_Signal_Handler (exception, msg);
1716 __gnat_install_handler ()
1718 struct sigaction act;
1720 /* Set up signal handler to map synchronous signals to appropriate
1721 exceptions. Make sure that the handler isn't interrupted by another
1722 signal that might cause a scheduling event! */
1725 = (void (*)(int, struct __siginfo *, void*)) __gnat_error_handler;
1726 act.sa_flags = SA_NODEFER | SA_RESTART | SA_SIGINFO;
1727 (void) sigemptyset (&act.sa_mask);
1729 (void) sigaction (SIGILL, &act, NULL);
1730 (void) sigaction (SIGFPE, &act, NULL);
1731 (void) sigaction (SIGSEGV, &act, NULL);
1732 (void) sigaction (SIGBUS, &act, NULL);
1734 __gnat_handler_installed = 1;
1737 /*******************/
1738 /* VxWorks Section */
1739 /*******************/
1741 #elif defined(__vxworks)
1744 #include <taskLib.h>
1752 #include "private/vThreadsP.h"
1755 void __gnat_error_handler (int, void *, struct sigcontext *);
1759 /* Directly vectored Interrupt routines are not supported when using RTPs. */
1761 extern int __gnat_inum_to_ivec (int);
1763 /* This is needed by the GNAT run time to handle Vxworks interrupts. */
1765 __gnat_inum_to_ivec (int num)
1767 return INUM_TO_IVEC (num);
1771 #if !defined(__alpha_vxworks) && (_WRS_VXWORKS_MAJOR != 6) && !defined(__RTP__)
1773 /* getpid is used by s-parint.adb, but is not defined by VxWorks, except
1774 on Alpha VxWorks and VxWorks 6.x (including RTPs). */
1776 extern long getpid (void);
1781 return taskIdSelf ();
1785 /* VxWorks 653 vThreads expects the field excCnt to be zeroed when a signal is.
1786 handled. The VxWorks version of longjmp does this; GCC's builtin_longjmp
1789 __gnat_clear_exception_count (void)
1792 WIND_TCB *currentTask = (WIND_TCB *) taskIdSelf();
1794 currentTask->vThreads.excCnt = 0;
1798 /* Handle different SIGnal to exception mappings in different VxWorks
1801 __gnat_map_signal (int sig)
1803 struct Exception_Data *exception;
1809 exception = &constraint_error;
1814 exception = &constraint_error;
1815 msg = "Floating point exception or SIGILL";
1818 exception = &storage_error;
1822 exception = &storage_error;
1823 msg = "SIGBUS: possible stack overflow";
1825 #elif (_WRS_VXWORKS_MAJOR == 6)
1827 exception = &constraint_error;
1831 /* In RTP mode a SIGSEGV is most likely due to a stack overflow,
1832 since stack checking uses the probing mechanism. */
1834 exception = &storage_error;
1835 msg = "SIGSEGV: possible stack overflow";
1838 exception = &program_error;
1842 /* VxWorks 6 kernel mode with probing. SIGBUS for guard page hit */
1844 exception = &storage_error;
1848 exception = &storage_error;
1849 msg = "SIGBUS: possible stack overflow";
1853 /* VxWorks 5: a SIGILL is most likely due to a stack overflow,
1854 since stack checking uses the stack limit mechanism. */
1856 exception = &storage_error;
1857 msg = "SIGILL: possible stack overflow";
1860 exception = &storage_error;
1864 exception = &program_error;
1869 exception = &program_error;
1870 msg = "unhandled signal";
1873 __gnat_clear_exception_count ();
1874 Raise_From_Signal_Handler (exception, msg);
1877 /* Tasking and Non-tasking signal handler. Map SIGnal to Ada exception
1878 propagation after the required low level adjustments. */
1881 __gnat_error_handler (int sig, void * si ATTRIBUTE_UNUSED,
1882 struct sigcontext * sc)
1886 /* VxWorks will always mask out the signal during the signal handler and
1887 will reenable it on a longjmp. GNAT does not generate a longjmp to
1888 return from a signal handler so the signal will still be masked unless
1890 sigprocmask (SIG_SETMASK, NULL, &mask);
1891 sigdelset (&mask, sig);
1892 sigprocmask (SIG_SETMASK, &mask, NULL);
1894 __gnat_map_signal (sig);
1898 __gnat_install_handler (void)
1900 struct sigaction act;
1902 /* Setup signal handler to map synchronous signals to appropriate
1903 exceptions. Make sure that the handler isn't interrupted by another
1904 signal that might cause a scheduling event! */
1906 act.sa_handler = __gnat_error_handler;
1907 act.sa_flags = SA_SIGINFO | SA_ONSTACK;
1908 sigemptyset (&act.sa_mask);
1910 /* For VxWorks, install all signal handlers, since pragma Interrupt_State
1911 applies to vectored hardware interrupts, not signals. */
1912 sigaction (SIGFPE, &act, NULL);
1913 sigaction (SIGILL, &act, NULL);
1914 sigaction (SIGSEGV, &act, NULL);
1915 sigaction (SIGBUS, &act, NULL);
1917 __gnat_handler_installed = 1;
1920 #define HAVE_GNAT_INIT_FLOAT
1923 __gnat_init_float (void)
1925 /* Disable overflow/underflow exceptions on the PPC processor, needed
1926 to get correct Ada semantics. Note that for AE653 vThreads, the HW
1927 overflow settings are an OS configuration issue. The instructions
1928 below have no effect. */
1929 #if defined (_ARCH_PPC) && !defined (_SOFT_FLOAT) && !defined (VTHREADS)
1934 #if (defined (__i386__) || defined (i386)) && !defined (VTHREADS)
1935 /* This is used to properly initialize the FPU on an x86 for each
1940 /* Similarly for SPARC64. Achieved by masking bits in the Trap Enable Mask
1941 field of the Floating-point Status Register (see the SPARC Architecture
1942 Manual Version 9, p 48). */
1943 #if defined (sparc64)
1945 #define FSR_TEM_NVM (1 << 27) /* Invalid operand */
1946 #define FSR_TEM_OFM (1 << 26) /* Overflow */
1947 #define FSR_TEM_UFM (1 << 25) /* Underflow */
1948 #define FSR_TEM_DZM (1 << 24) /* Division by Zero */
1949 #define FSR_TEM_NXM (1 << 23) /* Inexact result */
1953 __asm__("st %%fsr, %0" : "=m" (fsr));
1954 fsr &= ~(FSR_TEM_OFM | FSR_TEM_UFM);
1955 __asm__("ld %0, %%fsr" : : "m" (fsr));
1960 /* This subprogram is called by System.Task_Primitives.Operations.Enter_Task
1961 (if not null) when a new task is created. It is initialized by
1962 System.Stack_Checking.Operations.Initialize_Stack_Limit.
1963 The use of a hook avoids to drag stack checking subprograms if stack
1964 checking is not used. */
1965 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__)
2102 /* This must be in keeping with System.OS_Interface.Alternate_Stack_Size. */
2103 char __gnat_alternate_stack[64 * 1024]; /* 2 * MINSIGSTKSZ */
2105 static void __gnat_error_handler (int sig, siginfo_t * si, void * uc);
2107 /* Defined in xnu unix_signal.c */
2108 #define UC_RESET_ALT_STACK 0x80000000
2109 extern int sigreturn (void *uc, int flavour);
2112 __gnat_error_handler (int sig, siginfo_t * si, void * uc)
2114 struct Exception_Data *exception;
2121 /* FIXME: we need to detect the case of a *real* SIGSEGV. */
2122 exception = &storage_error;
2123 msg = "stack overflow or erroneous memory access";
2124 /* Reset the use of alt stack, so that the alt stack will be used
2125 for the next signal delivery. */
2126 sigreturn (NULL, UC_RESET_ALT_STACK);
2130 exception = &constraint_error;
2135 exception = &program_error;
2136 msg = "unhandled signal";
2139 Raise_From_Signal_Handler (exception, msg);
2143 __gnat_install_handler (void)
2145 struct sigaction act;
2147 /* Set up signal handler to map synchronous signals to appropriate
2148 exceptions. Make sure that the handler isn't interrupted by another
2149 signal that might cause a scheduling event! Also setup an alternate
2150 stack region for the handler execution so that stack overflows can be
2151 handled properly, avoiding a SEGV generation from stack usage by the
2152 handler itself (and it is required by Darwin). */
2155 stack.ss_sp = __gnat_alternate_stack;
2156 stack.ss_size = sizeof (__gnat_alternate_stack);
2158 sigaltstack (&stack, NULL);
2160 act.sa_flags = SA_NODEFER | SA_RESTART | SA_SIGINFO;
2161 act.sa_sigaction = __gnat_error_handler;
2162 sigemptyset (&act.sa_mask);
2164 /* Do not install handlers if interrupt state is "System". */
2165 if (__gnat_get_interrupt_state (SIGABRT) != 's')
2166 sigaction (SIGABRT, &act, NULL);
2167 if (__gnat_get_interrupt_state (SIGFPE) != 's')
2168 sigaction (SIGFPE, &act, NULL);
2169 if (__gnat_get_interrupt_state (SIGILL) != 's')
2170 sigaction (SIGILL, &act, NULL);
2172 act.sa_flags |= SA_ONSTACK;
2173 if (__gnat_get_interrupt_state (SIGSEGV) != 's')
2174 sigaction (SIGSEGV, &act, NULL);
2175 if (__gnat_get_interrupt_state (SIGBUS) != 's')
2176 sigaction (SIGBUS, &act, NULL);
2178 __gnat_handler_installed = 1;
2183 /* For all other versions of GNAT, the handler does nothing. */
2185 /*******************/
2186 /* Default Section */
2187 /*******************/
2190 __gnat_install_handler (void)
2192 __gnat_handler_installed = 1;
2197 /*********************/
2198 /* __gnat_init_float */
2199 /*********************/
2201 /* This routine is called as each process thread is created, for possible
2202 initialization of the FP processor. This version is used under INTERIX,
2203 WIN32 and could be used under OS/2. */
2205 #if defined (_WIN32) || defined (__INTERIX) || defined (__EMX__) \
2206 || defined (__Lynx__) || defined(__NetBSD__) || defined(__FreeBSD__) \
2207 || defined (__OpenBSD__)
2209 #define HAVE_GNAT_INIT_FLOAT
2212 __gnat_init_float (void)
2214 #if defined (__i386__) || defined (i386) || defined (__x86_64)
2216 /* This is used to properly initialize the FPU on an x86 for each
2221 #endif /* Defined __i386__ */
2225 #ifndef HAVE_GNAT_INIT_FLOAT
2227 /* All targets without a specific __gnat_init_float will use an empty one. */
2229 __gnat_init_float (void)
2234 /***********************************/
2235 /* __gnat_adjust_context_for_raise */
2236 /***********************************/
2238 #ifndef HAVE_GNAT_ADJUST_CONTEXT_FOR_RAISE
2240 /* All targets without a specific version will use an empty one. */
2242 /* Given UCONTEXT a pointer to a context structure received by a signal
2243 handler for SIGNO, perform the necessary adjustments to let the handler
2244 raise an exception. Calls to this routine are not conditioned by the
2245 propagation scheme in use. */
2248 __gnat_adjust_context_for_raise (int signo ATTRIBUTE_UNUSED,
2249 void *ucontext ATTRIBUTE_UNUSED)
2251 /* We used to compensate here for the raised from call vs raised from signal
2252 exception discrepancy with the GCC ZCX scheme, but this now can be dealt
2253 with generically in the unwinder (see GCC PR other/26208). Only the VMS
2254 ports still do the compensation described in the few lines below.
2256 *** Call vs signal exception discrepancy with GCC ZCX scheme ***
2258 The GCC unwinder expects to be dealing with call return addresses, since
2259 this is the "nominal" case of what we retrieve while unwinding a regular
2262 To evaluate if a handler applies at some point identified by a return
2263 address, the propagation engine needs to determine what region the
2264 corresponding call instruction pertains to. Because the return address
2265 may not be attached to the same region as the call, the unwinder always
2266 subtracts "some" amount from a return address to search the region
2267 tables, amount chosen to ensure that the resulting address is inside the
2270 When we raise an exception from a signal handler, e.g. to transform a
2271 SIGSEGV into Storage_Error, things need to appear as if the signal
2272 handler had been "called" by the instruction which triggered the signal,
2273 so that exception handlers that apply there are considered. What the
2274 unwinder will retrieve as the return address from the signal handler is
2275 what it will find as the faulting instruction address in the signal
2276 context pushed by the kernel. Leaving this address untouched looses, if
2277 the triggering instruction happens to be the very first of a region, as
2278 the later adjustments performed by the unwinder would yield an address
2279 outside that region. We need to compensate for the unwinder adjustments
2280 at some point, and this is what this routine is expected to do.
2282 signo is passed because on some targets for some signals the PC in
2283 context points to the instruction after the faulting one, in which case
2284 the unwinder adjustment is still desired. */