1 /****************************************************************************
3 * GNAT COMPILER COMPONENTS *
7 * C Implementation File *
9 * Copyright (C) 1992-2008, 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 2, 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. See the GNU General Public License *
17 * for more details. You should have received a copy of the GNU General *
18 * Public License distributed with GNAT; see file COPYING. If not, write *
19 * to the Free Software Foundation, 51 Franklin Street, Fifth Floor, *
20 * Boston, MA 02110-1301, USA. *
22 * As a special exception, if you link this file with other files to *
23 * produce an executable, this file does not by itself cause the resulting *
24 * executable to be covered by the GNU General Public License. This except- *
25 * ion does not however invalidate any other reasons why the executable *
26 * file might be covered by the GNU Public License. *
28 * GNAT was originally developed by the GNAT team at New York University. *
29 * Extensive contributions were provided by Ada Core Technologies Inc. *
31 ****************************************************************************/
33 /* This unit contains initialization circuits that are system dependent.
34 A major part of the functionality involves stack overflow checking.
35 The GCC backend generates probe instructions to test for stack overflow.
36 For details on the exact approach used to generate these probes, see the
37 "Using and Porting GCC" manual, in particular the "Stack Checking" section
38 and the subsection "Specifying How Stack Checking is Done". The handlers
39 installed by this file are used to catch the resulting signals that come
40 from these probes failing (i.e. touching protected pages). */
42 /* This file should be kept synchronized with 2sinit.ads, 2sinit.adb,
43 s-init-ae653-cert.adb and s-init-xi-sparc.adb. All these files implement
44 the required functionality for different targets. */
46 /* The following include is here to meet the published VxWorks requirement
47 that the __vxworks header appear before any other include. */
57 /* We don't have libiberty, so us malloc. */
58 #define xmalloc(S) malloc (S)
67 extern void __gnat_raise_program_error (const char *, int);
69 /* Addresses of exception data blocks for predefined exceptions. Tasking_Error
70 is not used in this unit, and the abort signal is only used on IRIX. */
71 extern struct Exception_Data constraint_error;
72 extern struct Exception_Data numeric_error;
73 extern struct Exception_Data program_error;
74 extern struct Exception_Data storage_error;
76 /* For the Cert run time we use the regular raise exception routine because
77 Raise_From_Signal_Handler is not available. */
79 #define Raise_From_Signal_Handler \
80 __gnat_raise_exception
81 extern void Raise_From_Signal_Handler (struct Exception_Data *, const char *);
83 #define Raise_From_Signal_Handler \
84 ada__exceptions__raise_from_signal_handler
85 extern void Raise_From_Signal_Handler (struct Exception_Data *, const char *);
88 /* Global values computed by the binder. */
89 int __gl_main_priority = -1;
90 int __gl_time_slice_val = -1;
91 char __gl_wc_encoding = 'n';
92 char __gl_locking_policy = ' ';
93 char __gl_queuing_policy = ' ';
94 char __gl_task_dispatching_policy = ' ';
95 char *__gl_priority_specific_dispatching = 0;
96 int __gl_num_specific_dispatching = 0;
97 char *__gl_interrupt_states = 0;
98 int __gl_num_interrupt_states = 0;
99 int __gl_unreserve_all_interrupts = 0;
100 int __gl_exception_tracebacks = 0;
101 int __gl_zero_cost_exceptions = 0;
102 int __gl_detect_blocking = 0;
103 int __gl_default_stack_size = -1;
104 int __gl_leap_seconds_support = 0;
105 int __gl_canonical_streams = 0;
107 /* Indication of whether synchronous signal handler has already been
108 installed by a previous call to adainit. */
109 int __gnat_handler_installed = 0;
112 int __gnat_inside_elab_final_code = 0;
113 /* ??? This variable is obsolete since 2001-08-29 but is kept to allow
114 bootstrap from old GNAT versions (< 3.15). */
117 /* HAVE_GNAT_INIT_FLOAT must be set on every targets where a __gnat_init_float
118 is defined. If this is not set then a void implementation will be defined
119 at the end of this unit. */
120 #undef HAVE_GNAT_INIT_FLOAT
122 /******************************/
123 /* __gnat_get_interrupt_state */
124 /******************************/
126 char __gnat_get_interrupt_state (int);
128 /* This routine is called from the runtime as needed to determine the state
129 of an interrupt, as set by an Interrupt_State pragma appearing anywhere
130 in the current partition. The input argument is the interrupt number,
131 and the result is one of the following:
133 'n' this interrupt not set by any Interrupt_State pragma
134 'u' Interrupt_State pragma set state to User
135 'r' Interrupt_State pragma set state to Runtime
136 's' Interrupt_State pragma set state to System */
139 __gnat_get_interrupt_state (int intrup)
141 if (intrup >= __gl_num_interrupt_states)
144 return __gl_interrupt_states [intrup];
147 /***********************************/
148 /* __gnat_get_specific_dispatching */
149 /***********************************/
151 char __gnat_get_specific_dispatching (int);
153 /* This routine is called from the runtime as needed to determine the
154 priority specific dispatching policy, as set by a
155 Priority_Specific_Dispatching pragma appearing anywhere in the current
156 partition. The input argument is the priority number, and the result
157 is the upper case first character of the policy name, e.g. 'F' for
158 FIFO_Within_Priorities. A space ' ' is returned if no
159 Priority_Specific_Dispatching pragma is used in the partition. */
162 __gnat_get_specific_dispatching (int priority)
164 if (__gl_num_specific_dispatching == 0)
166 else if (priority >= __gl_num_specific_dispatching)
169 return __gl_priority_specific_dispatching [priority];
174 /**********************/
175 /* __gnat_set_globals */
176 /**********************/
178 /* This routine is kept for bootstrapping purposes, since the binder generated
179 file now sets the __gl_* variables directly. */
182 __gnat_set_globals ()
195 #include <sys/time.h>
197 /* Some versions of AIX don't define SA_NODEFER. */
201 #endif /* SA_NODEFER */
203 /* Versions of AIX before 4.3 don't have nanosleep but provide
206 #ifndef _AIXVERSION_430
208 extern int nanosleep (struct timestruc_t *, struct timestruc_t *);
211 nanosleep (struct timestruc_t *Rqtp, struct timestruc_t *Rmtp)
213 return nsleep (Rqtp, Rmtp);
216 #endif /* _AIXVERSION_430 */
218 static void __gnat_error_handler (int sig, siginfo_t * si, void * uc);
221 __gnat_error_handler (int sig, siginfo_t * si, void * uc)
223 struct Exception_Data *exception;
229 /* FIXME: we need to detect the case of a *real* SIGSEGV. */
230 exception = &storage_error;
231 msg = "stack overflow or erroneous memory access";
235 exception = &constraint_error;
240 exception = &constraint_error;
245 exception = &program_error;
246 msg = "unhandled signal";
249 Raise_From_Signal_Handler (exception, msg);
253 __gnat_install_handler (void)
255 struct sigaction act;
257 /* Set up signal handler to map synchronous signals to appropriate
258 exceptions. Make sure that the handler isn't interrupted by another
259 signal that might cause a scheduling event! */
261 act.sa_flags = SA_NODEFER | SA_RESTART | SA_SIGINFO;
262 act.sa_sigaction = __gnat_error_handler;
263 sigemptyset (&act.sa_mask);
265 /* Do not install handlers if interrupt state is "System". */
266 if (__gnat_get_interrupt_state (SIGABRT) != 's')
267 sigaction (SIGABRT, &act, NULL);
268 if (__gnat_get_interrupt_state (SIGFPE) != 's')
269 sigaction (SIGFPE, &act, NULL);
270 if (__gnat_get_interrupt_state (SIGILL) != 's')
271 sigaction (SIGILL, &act, NULL);
272 if (__gnat_get_interrupt_state (SIGSEGV) != 's')
273 sigaction (SIGSEGV, &act, NULL);
274 if (__gnat_get_interrupt_state (SIGBUS) != 's')
275 sigaction (SIGBUS, &act, NULL);
277 __gnat_handler_installed = 1;
284 #elif defined(__alpha__) && defined(__osf__)
287 #include <sys/siginfo.h>
289 static void __gnat_error_handler (int, siginfo_t *, struct sigcontext *);
290 extern char *__gnat_get_code_loc (struct sigcontext *);
291 extern void __gnat_set_code_loc (struct sigcontext *, char *);
292 extern size_t __gnat_machine_state_length (void);
294 /* __gnat_adjust_context_for_raise - see comments along with the default
295 version later in this file. */
297 #define HAVE_GNAT_ADJUST_CONTEXT_FOR_RAISE
300 __gnat_adjust_context_for_raise (int signo, void *context)
302 struct sigcontext * sigcontext = (struct sigcontext *) context;
304 /* The fallback code fetches the faulting insn address from sc_pc, so
305 adjust that when need be. For SIGFPE, the required adjustment depends
306 on the trap shadow situation (see man ieee). */
309 /* ??? We never adjust here, considering that sc_pc always
310 designates the instruction following the one which trapped.
311 This is not necessarily true but corresponds to what we have
315 sigcontext->sc_pc ++;
320 (int sig, siginfo_t *sip, struct sigcontext *context)
322 struct Exception_Data *exception;
323 static int recurse = 0;
326 /* Adjusting is required for every fault context, so adjust for this one
327 now, before we possibly trigger a recursive fault below. */
328 __gnat_adjust_context_for_raise (sig, context);
330 /* If this was an explicit signal from a "kill", just resignal it. */
331 if (SI_FROMUSER (sip))
333 signal (sig, SIG_DFL);
334 kill (getpid(), sig);
337 /* Otherwise, treat it as something we handle. */
341 /* If the problem was permissions, this is a constraint error.
342 Likewise if the failing address isn't maximally aligned or if
345 ??? Using a static variable here isn't task-safe, but it's
346 much too hard to do anything else and we're just determining
347 which exception to raise. */
348 if (sip->si_code == SEGV_ACCERR
349 || (((long) sip->si_addr) & 3) != 0
352 exception = &constraint_error;
357 /* See if the page before the faulting page is accessible. Do that
358 by trying to access it. We'd like to simply try to access
359 4096 + the faulting address, but it's not guaranteed to be
360 the actual address, just to be on the same page. */
363 ((long) sip->si_addr & - getpagesize ()))[getpagesize ()];
364 msg = "stack overflow (or erroneous memory access)";
365 exception = &storage_error;
370 exception = &program_error;
375 exception = &constraint_error;
380 exception = &program_error;
381 msg = "unhandled signal";
385 Raise_From_Signal_Handler (exception, (char *) msg);
389 __gnat_install_handler (void)
391 struct sigaction act;
393 /* Setup signal handler to map synchronous signals to appropriate
394 exceptions. Make sure that the handler isn't interrupted by another
395 signal that might cause a scheduling event! */
397 act.sa_handler = (void (*) (int)) __gnat_error_handler;
398 act.sa_flags = SA_RESTART | SA_NODEFER | SA_SIGINFO;
399 sigemptyset (&act.sa_mask);
401 /* Do not install handlers if interrupt state is "System". */
402 if (__gnat_get_interrupt_state (SIGABRT) != 's')
403 sigaction (SIGABRT, &act, NULL);
404 if (__gnat_get_interrupt_state (SIGFPE) != 's')
405 sigaction (SIGFPE, &act, NULL);
406 if (__gnat_get_interrupt_state (SIGILL) != 's')
407 sigaction (SIGILL, &act, NULL);
408 if (__gnat_get_interrupt_state (SIGSEGV) != 's')
409 sigaction (SIGSEGV, &act, NULL);
410 if (__gnat_get_interrupt_state (SIGBUS) != 's')
411 sigaction (SIGBUS, &act, NULL);
413 __gnat_handler_installed = 1;
416 /* Routines called by s-mastop-tru64.adb. */
421 __gnat_get_code_loc (struct sigcontext *context)
423 return (char *) context->sc_pc;
427 __gnat_set_code_loc (struct sigcontext *context, char *pc)
429 context->sc_pc = (long) pc;
433 __gnat_machine_state_length (void)
435 return sizeof (struct sigcontext);
442 #elif defined (__hpux__)
445 #include <sys/ucontext.h>
448 __gnat_error_handler (int sig, siginfo_t *siginfo, void *ucontext);
452 (int sig, siginfo_t *siginfo ATTRIBUTE_UNUSED, void *ucontext)
454 struct Exception_Data *exception;
460 /* FIXME: we need to detect the case of a *real* SIGSEGV. */
461 exception = &storage_error;
462 msg = "stack overflow or erroneous memory access";
466 exception = &constraint_error;
471 exception = &constraint_error;
476 exception = &program_error;
477 msg = "unhandled signal";
480 Raise_From_Signal_Handler (exception, msg);
483 /* This must be in keeping with System.OS_Interface.Alternate_Stack_Size. */
484 #if defined (__hppa__)
485 char __gnat_alternate_stack[16 * 1024]; /* 2 * SIGSTKSZ */
487 char __gnat_alternate_stack[128 * 1024]; /* MINSIGSTKSZ */
491 __gnat_install_handler (void)
493 struct sigaction act;
495 /* Set up signal handler to map synchronous signals to appropriate
496 exceptions. Make sure that the handler isn't interrupted by another
497 signal that might cause a scheduling event! Also setup an alternate
498 stack region for the handler execution so that stack overflows can be
499 handled properly, avoiding a SEGV generation from stack usage by the
503 stack.ss_sp = __gnat_alternate_stack;
504 stack.ss_size = sizeof (__gnat_alternate_stack);
506 sigaltstack (&stack, NULL);
508 act.sa_sigaction = __gnat_error_handler;
509 act.sa_flags = SA_NODEFER | SA_RESTART | SA_SIGINFO;
510 sigemptyset (&act.sa_mask);
512 /* Do not install handlers if interrupt state is "System". */
513 if (__gnat_get_interrupt_state (SIGABRT) != 's')
514 sigaction (SIGABRT, &act, NULL);
515 if (__gnat_get_interrupt_state (SIGFPE) != 's')
516 sigaction (SIGFPE, &act, NULL);
517 if (__gnat_get_interrupt_state (SIGILL) != 's')
518 sigaction (SIGILL, &act, NULL);
519 if (__gnat_get_interrupt_state (SIGBUS) != 's')
520 sigaction (SIGBUS, &act, NULL);
521 act.sa_flags |= SA_ONSTACK;
522 if (__gnat_get_interrupt_state (SIGSEGV) != 's')
523 sigaction (SIGSEGV, &act, NULL);
525 __gnat_handler_installed = 1;
528 /*********************/
529 /* GNU/Linux Section */
530 /*********************/
532 #elif defined (linux) && (defined (i386) || defined (__x86_64__) \
533 || defined (__ia64__) || defined (__powerpc__))
537 #define __USE_GNU 1 /* required to get REG_EIP/RIP from glibc's ucontext.h */
538 #include <sys/ucontext.h>
540 /* GNU/Linux, which uses glibc, does not define NULL in included
544 #define NULL ((void *) 0)
549 /* MaRTE OS provides its own version of sigaction, sigfillset, and
550 sigemptyset (overriding these symbol names). We want to make sure that
551 the versions provided by the underlying C library are used here (these
552 versions are renamed by MaRTE to linux_sigaction, fake_linux_sigfillset,
553 and fake_linux_sigemptyset, respectively). The MaRTE library will not
554 always be present (it will not be linked if no tasking constructs are
555 used), so we use the weak symbol mechanism to point always to the symbols
556 defined within the C library. */
558 #pragma weak linux_sigaction
559 int linux_sigaction (int signum, const struct sigaction *act,
560 struct sigaction *oldact) {
561 return sigaction (signum, act, oldact);
563 #define sigaction(signum, act, oldact) linux_sigaction (signum, act, oldact)
565 #pragma weak fake_linux_sigfillset
566 void fake_linux_sigfillset (sigset_t *set) {
569 #define sigfillset(set) fake_linux_sigfillset (set)
571 #pragma weak fake_linux_sigemptyset
572 void fake_linux_sigemptyset (sigset_t *set) {
575 #define sigemptyset(set) fake_linux_sigemptyset (set)
579 static void __gnat_error_handler (int, siginfo_t *siginfo, void *ucontext);
581 #if defined (i386) || defined (__x86_64__) || defined (__ia64__)
583 #define HAVE_GNAT_ADJUST_CONTEXT_FOR_RAISE
586 __gnat_adjust_context_for_raise (int signo ATTRIBUTE_UNUSED, void *ucontext)
588 mcontext_t *mcontext = &((ucontext_t *) ucontext)->uc_mcontext;
590 /* On the i386 and x86-64 architectures, stack checking is performed by
591 means of probes with moving stack pointer, that is to say the probed
592 address is always the value of the stack pointer. Upon hitting the
593 guard page, the stack pointer therefore points to an inaccessible
594 address and an alternate signal stack is needed to run the handler.
595 But there is an additional twist: on these architectures, the EH
596 return code writes the address of the handler at the target CFA's
597 value on the stack before doing the jump. As a consequence, if
598 there is an active handler in the frame whose stack has overflowed,
599 the stack pointer must nevertheless point to an accessible address
600 by the time the EH return is executed.
602 We therefore adjust the saved value of the stack pointer by the size
603 of one page, in order to make sure that it points to an accessible
604 address in case it's used as the target CFA. The stack checking code
605 guarantees that this page is unused by the time this happens. */
608 unsigned long pattern = *(unsigned long *)mcontext->gregs[REG_EIP];
609 /* The pattern is "orl $0x0,(%esp)" for a probe in 32-bit mode. */
610 if (signo == SIGSEGV && pattern == 0x00240c83)
611 mcontext->gregs[REG_ESP] += 4096;
612 #elif defined (__x86_64__)
613 unsigned long pattern = *(unsigned long *)mcontext->gregs[REG_RIP];
614 /* The pattern is "orq $0x0,(%rsp)" for a probe in 64-bit mode. */
615 if (signo == SIGSEGV && (pattern & 0xffffffffff) == 0x00240c8348)
616 mcontext->gregs[REG_RSP] += 4096;
617 #elif defined (__ia64__)
618 /* ??? The IA-64 unwinder doesn't compensate for signals. */
626 __gnat_error_handler (int sig,
627 siginfo_t *siginfo ATTRIBUTE_UNUSED,
630 struct Exception_Data *exception;
632 static int recurse = 0;
637 /* If the problem was permissions, this is a constraint error.
638 Likewise if the failing address isn't maximally aligned or if
641 ??? Using a static variable here isn't task-safe, but it's
642 much too hard to do anything else and we're just determining
643 which exception to raise. */
646 exception = &constraint_error;
651 /* Here we would like a discrimination test to see whether the
652 page before the faulting address is accessible. Unfortunately
653 Linux seems to have no way of giving us the faulting address.
655 In versions of a-init.c before 1.95, we had a test of the page
656 before the stack pointer using:
660 ((long) info->esp_at_signal & - getpagesize ()))[getpagesize ()];
662 but that's wrong, since it tests the stack pointer location, and
663 the current stack probe code does not move the stack pointer
664 until all probes succeed.
666 For now we simply do not attempt any discrimination at all. Note
667 that this is quite acceptable, since a "real" SIGSEGV can only
668 occur as the result of an erroneous program. */
670 msg = "stack overflow (or erroneous memory access)";
671 exception = &storage_error;
676 exception = &constraint_error;
681 exception = &constraint_error;
686 exception = &program_error;
687 msg = "unhandled signal";
691 /* We adjust the interrupted context here (and not in the fallback
692 unwinding routine) because recent versions of the Native POSIX
693 Thread Library (NPTL) are compiled with unwind information, so
694 the fallback routine is never executed for signal frames. */
695 __gnat_adjust_context_for_raise (sig, ucontext);
697 Raise_From_Signal_Handler (exception, msg);
700 #if defined (i386) || defined (__x86_64__)
701 /* This must be in keeping with System.OS_Interface.Alternate_Stack_Size. */
702 char __gnat_alternate_stack[16 * 1024]; /* 2 * SIGSTKSZ */
706 #include <sys/mman.h>
707 #include <native/task.h>
713 __gnat_install_handler (void)
715 struct sigaction act;
720 if (__gl_main_priority == -1)
723 prio = __gl_main_priority;
725 /* Avoid memory swapping for this program */
727 mlockall (MCL_CURRENT|MCL_FUTURE);
729 /* Turn the current Linux task into a native Xenomai task */
731 rt_task_shadow(&main_task, "environment_task", prio, T_FPU);
734 /* Set up signal handler to map synchronous signals to appropriate
735 exceptions. Make sure that the handler isn't interrupted by another
736 signal that might cause a scheduling event! Also setup an alternate
737 stack region for the handler execution so that stack overflows can be
738 handled properly, avoiding a SEGV generation from stack usage by the
741 #if defined (i386) || defined (__x86_64__)
743 stack.ss_sp = __gnat_alternate_stack;
744 stack.ss_size = sizeof (__gnat_alternate_stack);
746 sigaltstack (&stack, NULL);
749 act.sa_sigaction = __gnat_error_handler;
750 act.sa_flags = SA_NODEFER | SA_RESTART | SA_SIGINFO;
751 sigemptyset (&act.sa_mask);
753 /* Do not install handlers if interrupt state is "System". */
754 if (__gnat_get_interrupt_state (SIGABRT) != 's')
755 sigaction (SIGABRT, &act, NULL);
756 if (__gnat_get_interrupt_state (SIGFPE) != 's')
757 sigaction (SIGFPE, &act, NULL);
758 if (__gnat_get_interrupt_state (SIGILL) != 's')
759 sigaction (SIGILL, &act, NULL);
760 if (__gnat_get_interrupt_state (SIGBUS) != 's')
761 sigaction (SIGBUS, &act, NULL);
762 #if defined (i386) || defined (__x86_64__)
763 act.sa_flags |= SA_ONSTACK;
765 if (__gnat_get_interrupt_state (SIGSEGV) != 's')
766 sigaction (SIGSEGV, &act, NULL);
768 __gnat_handler_installed = 1;
784 #define SIGADAABORT 48
785 #define SIGNAL_STACK_SIZE 4096
786 #define SIGNAL_STACK_ALIGNMENT 64
788 #define Check_Abort_Status \
789 system__soft_links__check_abort_status
790 extern int (*Check_Abort_Status) (void);
792 extern struct Exception_Data _abort_signal;
794 static void __gnat_error_handler (int, int, sigcontext_t *);
796 /* We are not setting the SA_SIGINFO bit in the sigaction flags when
797 connecting that handler, with the effects described in the sigaction
801 If cleared and the signal is caught, the first argument is
802 also the signal number but the second argument is the signal
803 code identifying the cause of the signal. The third argument
804 points to a sigcontext_t structure containing the receiving
805 process's context when the signal was delivered. */
808 __gnat_error_handler (int sig, int code, sigcontext_t *sc ATTRIBUTE_UNUSED)
810 struct Exception_Data *exception;
818 exception = &program_error;
819 msg = "SIGSEGV: (Invalid virtual address)";
821 else if (code == ENXIO)
823 exception = &program_error;
824 msg = "SIGSEGV: (Read beyond mapped object)";
826 else if (code == ENOSPC)
828 exception = &program_error; /* ??? storage_error ??? */
829 msg = "SIGSEGV: (Autogrow for file failed)";
831 else if (code == EACCES || code == EEXIST)
833 /* ??? We handle stack overflows here, some of which do trigger
834 SIGSEGV + EEXIST on Irix 6.5 although EEXIST is not part of
835 the documented valid codes for SEGV in the signal(5) man
838 /* ??? Re-add smarts to further verify that we launched
839 the stack into a guard page, not an attempt to
840 write to .text or something. */
841 exception = &storage_error;
842 msg = "SIGSEGV: (stack overflow or erroneous memory access)";
846 /* Just in case the OS guys did it to us again. Sometimes
847 they fail to document all of the valid codes that are
848 passed to signal handlers, just in case someone depends
849 on knowing all the codes. */
850 exception = &program_error;
851 msg = "SIGSEGV: (Undocumented reason)";
856 /* Map all bus errors to Program_Error. */
857 exception = &program_error;
862 /* Map all fpe errors to Constraint_Error. */
863 exception = &constraint_error;
868 if ((*Check_Abort_Status) ())
870 exception = &_abort_signal;
879 /* Everything else is a Program_Error. */
880 exception = &program_error;
881 msg = "unhandled signal";
884 Raise_From_Signal_Handler (exception, msg);
888 __gnat_install_handler (void)
890 struct sigaction act;
892 /* Setup signal handler to map synchronous signals to appropriate
893 exceptions. Make sure that the handler isn't interrupted by another
894 signal that might cause a scheduling event! */
896 act.sa_handler = __gnat_error_handler;
897 act.sa_flags = SA_NODEFER + SA_RESTART;
898 sigfillset (&act.sa_mask);
899 sigemptyset (&act.sa_mask);
901 /* Do not install handlers if interrupt state is "System". */
902 if (__gnat_get_interrupt_state (SIGABRT) != 's')
903 sigaction (SIGABRT, &act, NULL);
904 if (__gnat_get_interrupt_state (SIGFPE) != 's')
905 sigaction (SIGFPE, &act, NULL);
906 if (__gnat_get_interrupt_state (SIGILL) != 's')
907 sigaction (SIGILL, &act, NULL);
908 if (__gnat_get_interrupt_state (SIGSEGV) != 's')
909 sigaction (SIGSEGV, &act, NULL);
910 if (__gnat_get_interrupt_state (SIGBUS) != 's')
911 sigaction (SIGBUS, &act, NULL);
912 if (__gnat_get_interrupt_state (SIGADAABORT) != 's')
913 sigaction (SIGADAABORT, &act, NULL);
915 __gnat_handler_installed = 1;
918 /*******************/
920 /*******************/
922 #elif defined (__Lynx__)
928 __gnat_error_handler (int sig)
930 struct Exception_Data *exception;
936 exception = &constraint_error;
940 exception = &constraint_error;
944 exception = &storage_error;
945 msg = "stack overflow or erroneous memory access";
948 exception = &constraint_error;
952 exception = &program_error;
953 msg = "unhandled signal";
956 Raise_From_Signal_Handler(exception, msg);
960 __gnat_install_handler(void)
962 struct sigaction act;
964 act.sa_handler = __gnat_error_handler;
966 sigemptyset (&act.sa_mask);
968 /* Do not install handlers if interrupt state is "System". */
969 if (__gnat_get_interrupt_state (SIGFPE) != 's')
970 sigaction (SIGFPE, &act, NULL);
971 if (__gnat_get_interrupt_state (SIGILL) != 's')
972 sigaction (SIGILL, &act, NULL);
973 if (__gnat_get_interrupt_state (SIGSEGV) != 's')
974 sigaction (SIGSEGV, &act, NULL);
975 if (__gnat_get_interrupt_state (SIGBUS) != 's')
976 sigaction (SIGBUS, &act, NULL);
978 __gnat_handler_installed = 1;
981 /*******************/
982 /* Solaris Section */
983 /*******************/
985 #elif defined (sun) && defined (__SVR4) && !defined (__vxworks)
989 #include <sys/ucontext.h>
990 #include <sys/regset.h>
992 /* The code below is common to SPARC and x86. Beware of the delay slot
993 differences for signal context adjustments. */
995 #if defined (__sparc)
996 #define RETURN_ADDR_OFFSET 8
998 #define RETURN_ADDR_OFFSET 0
1001 /* Likewise regarding how the "instruction pointer" register slot can
1002 be identified in signal machine contexts. We have either "REG_PC"
1003 or "PC" at hand, depending on the target CPU and Solaris version. */
1005 #if !defined (REG_PC)
1009 static void __gnat_error_handler (int, siginfo_t *, ucontext_t *);
1012 __gnat_error_handler (int sig, siginfo_t *sip, ucontext_t *uctx)
1014 struct Exception_Data *exception;
1015 static int recurse = 0;
1018 /* If this was an explicit signal from a "kill", just resignal it. */
1019 if (SI_FROMUSER (sip))
1021 signal (sig, SIG_DFL);
1022 kill (getpid(), sig);
1025 /* Otherwise, treat it as something we handle. */
1029 /* If the problem was permissions, this is a constraint error.
1030 Likewise if the failing address isn't maximally aligned or if
1033 ??? Using a static variable here isn't task-safe, but it's
1034 much too hard to do anything else and we're just determining
1035 which exception to raise. */
1036 if (sip->si_code == SEGV_ACCERR
1037 || (((long) sip->si_addr) & 3) != 0
1040 exception = &constraint_error;
1045 /* See if the page before the faulting page is accessible. Do that
1046 by trying to access it. We'd like to simply try to access
1047 4096 + the faulting address, but it's not guaranteed to be
1048 the actual address, just to be on the same page. */
1051 ((long) sip->si_addr & - getpagesize ()))[getpagesize ()];
1052 exception = &storage_error;
1053 msg = "stack overflow (or erroneous memory access)";
1058 exception = &program_error;
1063 exception = &constraint_error;
1068 exception = &program_error;
1069 msg = "unhandled signal";
1074 Raise_From_Signal_Handler (exception, msg);
1078 __gnat_install_handler (void)
1080 struct sigaction act;
1082 /* Set up signal handler to map synchronous signals to appropriate
1083 exceptions. Make sure that the handler isn't interrupted by another
1084 signal that might cause a scheduling event! */
1086 act.sa_handler = __gnat_error_handler;
1087 act.sa_flags = SA_NODEFER | SA_RESTART | SA_SIGINFO;
1088 sigemptyset (&act.sa_mask);
1090 /* Do not install handlers if interrupt state is "System". */
1091 if (__gnat_get_interrupt_state (SIGABRT) != 's')
1092 sigaction (SIGABRT, &act, NULL);
1093 if (__gnat_get_interrupt_state (SIGFPE) != 's')
1094 sigaction (SIGFPE, &act, NULL);
1095 if (__gnat_get_interrupt_state (SIGSEGV) != 's')
1096 sigaction (SIGSEGV, &act, NULL);
1097 if (__gnat_get_interrupt_state (SIGBUS) != 's')
1098 sigaction (SIGBUS, &act, NULL);
1100 __gnat_handler_installed = 1;
1109 /* Routine called from binder to override default feature values. */
1110 void __gnat_set_features ();
1111 int __gnat_features_set = 0;
1113 long __gnat_error_handler (int *, void *);
1116 #define lib_get_curr_invo_context LIB$I64_GET_CURR_INVO_CONTEXT
1117 #define lib_get_prev_invo_context LIB$I64_GET_PREV_INVO_CONTEXT
1118 #define lib_get_invo_handle LIB$I64_GET_INVO_HANDLE
1120 #define lib_get_curr_invo_context LIB$GET_CURR_INVO_CONTEXT
1121 #define lib_get_prev_invo_context LIB$GET_PREV_INVO_CONTEXT
1122 #define lib_get_invo_handle LIB$GET_INVO_HANDLE
1125 #if defined (IN_RTS) && !defined (__IA64)
1127 /* The prehandler actually gets control first on a condition. It swaps the
1128 stack pointer and calls the handler (__gnat_error_handler). */
1129 extern long __gnat_error_prehandler (void);
1131 extern char *__gnat_error_prehandler_stack; /* Alternate signal stack */
1134 /* Define macro symbols for the VMS conditions that become Ada exceptions.
1135 Most of these are also defined in the header file ssdef.h which has not
1136 yet been converted to be recognized by GNU C. */
1138 /* Defining these as macros, as opposed to external addresses, allows
1139 them to be used in a case statement below. */
1140 #define SS$_ACCVIO 12
1141 #define SS$_HPARITH 1284
1142 #define SS$_STKOVF 1364
1143 #define SS$_RESIGNAL 2328
1145 /* These codes are in standard message libraries. */
1146 extern int CMA$_EXIT_THREAD;
1147 extern int SS$_DEBUG;
1148 extern int SS$_INTDIV;
1149 extern int LIB$_KEYNOTFOU;
1150 extern int LIB$_ACTIMAGE;
1151 extern int MTH$_FLOOVEMAT; /* Some ACVC_21 CXA tests */
1153 /* These codes are non standard, which is to say the author is
1154 not sure if they are defined in the standard message libraries
1155 so keep them as macros for now. */
1156 #define RDB$_STREAM_EOF 20480426
1157 #define FDL$_UNPRIKW 11829410
1159 struct cond_except {
1161 const struct Exception_Data *except;
1164 struct descriptor_s {unsigned short len, mbz; __char_ptr32 adr; };
1166 /* Conditions that don't have an Ada exception counterpart must raise
1167 Non_Ada_Error. Since this is defined in s-auxdec, it should only be
1168 referenced by user programs, not the compiler or tools. Hence the
1173 #define Status_Error ada__io_exceptions__status_error
1174 extern struct Exception_Data Status_Error;
1176 #define Mode_Error ada__io_exceptions__mode_error
1177 extern struct Exception_Data Mode_Error;
1179 #define Name_Error ada__io_exceptions__name_error
1180 extern struct Exception_Data Name_Error;
1182 #define Use_Error ada__io_exceptions__use_error
1183 extern struct Exception_Data Use_Error;
1185 #define Device_Error ada__io_exceptions__device_error
1186 extern struct Exception_Data Device_Error;
1188 #define End_Error ada__io_exceptions__end_error
1189 extern struct Exception_Data End_Error;
1191 #define Data_Error ada__io_exceptions__data_error
1192 extern struct Exception_Data Data_Error;
1194 #define Layout_Error ada__io_exceptions__layout_error
1195 extern struct Exception_Data Layout_Error;
1197 #define Non_Ada_Error system__aux_dec__non_ada_error
1198 extern struct Exception_Data Non_Ada_Error;
1200 #define Coded_Exception system__vms_exception_table__coded_exception
1201 extern struct Exception_Data *Coded_Exception (Exception_Code);
1203 #define Base_Code_In system__vms_exception_table__base_code_in
1204 extern Exception_Code Base_Code_In (Exception_Code);
1206 /* DEC Ada exceptions are not defined in a header file, so they
1207 must be declared as external addresses. */
1209 extern int ADA$_PROGRAM_ERROR;
1210 extern int ADA$_LOCK_ERROR;
1211 extern int ADA$_EXISTENCE_ERROR;
1212 extern int ADA$_KEY_ERROR;
1213 extern int ADA$_KEYSIZERR;
1214 extern int ADA$_STAOVF;
1215 extern int ADA$_CONSTRAINT_ERRO;
1216 extern int ADA$_IOSYSFAILED;
1217 extern int ADA$_LAYOUT_ERROR;
1218 extern int ADA$_STORAGE_ERROR;
1219 extern int ADA$_DATA_ERROR;
1220 extern int ADA$_DEVICE_ERROR;
1221 extern int ADA$_END_ERROR;
1222 extern int ADA$_MODE_ERROR;
1223 extern int ADA$_NAME_ERROR;
1224 extern int ADA$_STATUS_ERROR;
1225 extern int ADA$_NOT_OPEN;
1226 extern int ADA$_ALREADY_OPEN;
1227 extern int ADA$_USE_ERROR;
1228 extern int ADA$_UNSUPPORTED;
1229 extern int ADA$_FAC_MODE_MISMAT;
1230 extern int ADA$_ORG_MISMATCH;
1231 extern int ADA$_RFM_MISMATCH;
1232 extern int ADA$_RAT_MISMATCH;
1233 extern int ADA$_MRS_MISMATCH;
1234 extern int ADA$_MRN_MISMATCH;
1235 extern int ADA$_KEY_MISMATCH;
1236 extern int ADA$_MAXLINEXC;
1237 extern int ADA$_LINEXCMRS;
1239 /* DEC Ada specific conditions. */
1240 static const struct cond_except dec_ada_cond_except_table [] = {
1241 {&ADA$_PROGRAM_ERROR, &program_error},
1242 {&ADA$_USE_ERROR, &Use_Error},
1243 {&ADA$_KEYSIZERR, &program_error},
1244 {&ADA$_STAOVF, &storage_error},
1245 {&ADA$_CONSTRAINT_ERRO, &constraint_error},
1246 {&ADA$_IOSYSFAILED, &Device_Error},
1247 {&ADA$_LAYOUT_ERROR, &Layout_Error},
1248 {&ADA$_STORAGE_ERROR, &storage_error},
1249 {&ADA$_DATA_ERROR, &Data_Error},
1250 {&ADA$_DEVICE_ERROR, &Device_Error},
1251 {&ADA$_END_ERROR, &End_Error},
1252 {&ADA$_MODE_ERROR, &Mode_Error},
1253 {&ADA$_NAME_ERROR, &Name_Error},
1254 {&ADA$_STATUS_ERROR, &Status_Error},
1255 {&ADA$_NOT_OPEN, &Use_Error},
1256 {&ADA$_ALREADY_OPEN, &Use_Error},
1257 {&ADA$_USE_ERROR, &Use_Error},
1258 {&ADA$_UNSUPPORTED, &Use_Error},
1259 {&ADA$_FAC_MODE_MISMAT, &Use_Error},
1260 {&ADA$_ORG_MISMATCH, &Use_Error},
1261 {&ADA$_RFM_MISMATCH, &Use_Error},
1262 {&ADA$_RAT_MISMATCH, &Use_Error},
1263 {&ADA$_MRS_MISMATCH, &Use_Error},
1264 {&ADA$_MRN_MISMATCH, &Use_Error},
1265 {&ADA$_KEY_MISMATCH, &Use_Error},
1266 {&ADA$_MAXLINEXC, &constraint_error},
1267 {&ADA$_LINEXCMRS, &constraint_error},
1272 /* Already handled by a pragma Import_Exception
1273 in Aux_IO_Exceptions */
1274 {&ADA$_LOCK_ERROR, &Lock_Error},
1275 {&ADA$_EXISTENCE_ERROR, &Existence_Error},
1276 {&ADA$_KEY_ERROR, &Key_Error},
1281 /* Non-DEC Ada specific conditions. We could probably also put
1282 SS$_HPARITH here and possibly SS$_ACCVIO, SS$_STKOVF. */
1283 static const struct cond_except cond_except_table [] = {
1284 {&MTH$_FLOOVEMAT, &constraint_error},
1285 {&SS$_INTDIV, &constraint_error},
1289 /* To deal with VMS conditions and their mapping to Ada exceptions,
1290 the __gnat_error_handler routine below is installed as an exception
1291 vector having precedence over DEC frame handlers. Some conditions
1292 still need to be handled by such handlers, however, in which case
1293 __gnat_error_handler needs to return SS$_RESIGNAL. Consider for
1294 instance the use of a third party library compiled with DECAda and
1295 performing its own exception handling internally.
1297 To allow some user-level flexibility, which conditions should be
1298 resignaled is controlled by a predicate function, provided with the
1299 condition value and returning a boolean indication stating whether
1300 this condition should be resignaled or not.
1302 That predicate function is called indirectly, via a function pointer,
1303 by __gnat_error_handler, and changing that pointer is allowed to the
1304 the user code by way of the __gnat_set_resignal_predicate interface.
1306 The user level function may then implement what it likes, including
1307 for instance the maintenance of a dynamic data structure if the set
1308 of to be resignalled conditions has to change over the program's
1311 ??? This is not a perfect solution to deal with the possible
1312 interactions between the GNAT and the DECAda exception handling
1313 models and better (more general) schemes are studied. This is so
1314 just provided as a convenient workaround in the meantime, and
1315 should be use with caution since the implementation has been kept
1319 resignal_predicate (int code);
1321 const int *cond_resignal_table [] = {
1326 (int *) RDB$_STREAM_EOF,
1327 (int *) FDL$_UNPRIKW,
1331 const int facility_resignal_table [] = {
1332 0x1380000, /* RDB */
1333 0x2220000, /* SQL */
1337 /* Default GNAT predicate for resignaling conditions. */
1340 __gnat_default_resignal_p (int code)
1344 for (i = 0; facility_resignal_table [i]; i++)
1345 if ((code & 0xfff0000) == facility_resignal_table [i])
1348 for (i = 0, iexcept = 0;
1349 cond_resignal_table [i] &&
1350 !(iexcept = LIB$MATCH_COND (&code, &cond_resignal_table [i]));
1356 /* Static pointer to predicate that the __gnat_error_handler exception
1357 vector invokes to determine if it should resignal a condition. */
1359 static resignal_predicate * __gnat_resignal_p = __gnat_default_resignal_p;
1361 /* User interface to change the predicate pointer to PREDICATE. Reset to
1362 the default if PREDICATE is null. */
1365 __gnat_set_resignal_predicate (resignal_predicate * predicate)
1368 __gnat_resignal_p = __gnat_default_resignal_p;
1370 __gnat_resignal_p = predicate;
1373 /* Should match System.Parameters.Default_Exception_Msg_Max_Length. */
1374 #define Default_Exception_Msg_Max_Length 512
1376 /* Action routine for SYS$PUTMSG. There may be multiple
1377 conditions, each with text to be appended to MESSAGE
1378 and separated by line termination. */
1381 copy_msg (msgdesc, message)
1382 struct descriptor_s *msgdesc;
1385 int len = strlen (message);
1388 /* Check for buffer overflow and skip. */
1389 if (len > 0 && len <= Default_Exception_Msg_Max_Length - 3)
1391 strcat (message, "\r\n");
1395 /* Check for buffer overflow and truncate if necessary. */
1396 copy_len = (len + msgdesc->len <= Default_Exception_Msg_Max_Length - 1 ?
1398 Default_Exception_Msg_Max_Length - 1 - len);
1399 strncpy (&message [len], msgdesc->adr, copy_len);
1400 message [len + copy_len] = 0;
1406 __gnat_handle_vms_condition (int *sigargs, void *mechargs)
1408 struct Exception_Data *exception = 0;
1409 Exception_Code base_code;
1410 struct descriptor_s gnat_facility = {4,0,"GNAT"};
1411 char message [Default_Exception_Msg_Max_Length];
1413 const char *msg = "";
1415 /* Check for conditions to resignal which aren't effected by pragma
1416 Import_Exception. */
1417 if (__gnat_resignal_p (sigargs [1]))
1418 return SS$_RESIGNAL;
1421 /* See if it's an imported exception. Beware that registered exceptions
1422 are bound to their base code, with the severity bits masked off. */
1423 base_code = Base_Code_In ((Exception_Code) sigargs [1]);
1424 exception = Coded_Exception (base_code);
1430 /* Subtract PC & PSL fields which messes with PUTMSG. */
1432 SYS$PUTMSG (sigargs, copy_msg, &gnat_facility, message);
1436 exception->Name_Length = 19;
1437 /* ??? The full name really should be get sys$getmsg returns. */
1438 exception->Full_Name = "IMPORTED_EXCEPTION";
1439 exception->Import_Code = base_code;
1442 /* Do not adjust the program counter as already points to the next
1443 instruction (just after the call to LIB$STOP). */
1444 Raise_From_Signal_Handler (exception, msg);
1453 if (sigargs[3] == 0)
1455 exception = &constraint_error;
1456 msg = "access zero";
1460 exception = &storage_error;
1461 msg = "stack overflow (or erroneous memory access)";
1463 __gnat_adjust_context_for_raise (0, (void *)mechargs);
1467 exception = &storage_error;
1468 msg = "stack overflow";
1469 __gnat_adjust_context_for_raise (0, (void *)mechargs);
1474 return SS$_RESIGNAL; /* toplev.c handles for compiler */
1476 exception = &constraint_error;
1477 msg = "arithmetic error";
1479 /* No need to adjust pc on Alpha: the pc is already on the instruction
1480 after the trapping one. */
1481 __gnat_adjust_context_for_raise (0, (void *)mechargs);
1491 /* Scan the DEC Ada exception condition table for a match and fetch
1492 the associated GNAT exception pointer. */
1494 dec_ada_cond_except_table [i].cond &&
1495 !LIB$MATCH_COND (&sigargs [1],
1496 &dec_ada_cond_except_table [i].cond);
1498 exception = (struct Exception_Data *)
1499 dec_ada_cond_except_table [i].except;
1503 /* Scan the VMS standard condition table for a match and fetch
1504 the associated GNAT exception pointer. */
1506 cond_except_table [i].cond &&
1507 !LIB$MATCH_COND (&sigargs [1], &cond_except_table [i].cond);
1509 exception = (struct Exception_Data *)
1510 cond_except_table [i].except;
1513 /* User programs expect Non_Ada_Error to be raised, reference
1514 DEC Ada test CXCONDHAN. */
1515 exception = &Non_Ada_Error;
1519 exception = &program_error;
1522 /* Subtract PC & PSL fields which messes with PUTMSG. */
1524 SYS$PUTMSG (sigargs, copy_msg, &gnat_facility, message);
1530 Raise_From_Signal_Handler (exception, msg);
1534 __gnat_error_handler (int *sigargs, void *mechargs)
1536 return __gnat_handle_vms_condition (sigargs, mechargs);
1540 __gnat_install_handler (void)
1542 long prvhnd ATTRIBUTE_UNUSED;
1544 #if !defined (IN_RTS)
1545 SYS$SETEXV (1, __gnat_error_handler, 3, &prvhnd);
1548 /* On alpha-vms, we avoid the global vector annoyance thanks to frame based
1549 handlers to turn conditions into exceptions since GCC 3.4. The global
1550 vector is still required for earlier GCC versions. We're resorting to
1551 the __gnat_error_prehandler assembly function in this case. */
1553 #if defined (IN_RTS) && defined (__alpha__)
1554 if ((__GNUC__ * 10 + __GNUC_MINOR__) < 34)
1556 char * c = (char *) xmalloc (2049);
1558 __gnat_error_prehandler_stack = &c[2048];
1559 SYS$SETEXV (1, __gnat_error_prehandler, 3, &prvhnd);
1563 __gnat_handler_installed = 1;
1566 /* __gnat_adjust_context_for_raise for Alpha - see comments along with the
1567 default version later in this file. */
1569 #if defined (IN_RTS) && defined (__alpha__)
1571 #include <vms/chfctxdef.h>
1572 #include <vms/chfdef.h>
1574 #define HAVE_GNAT_ADJUST_CONTEXT_FOR_RAISE
1577 __gnat_adjust_context_for_raise (int signo ATTRIBUTE_UNUSED, void *ucontext)
1579 /* Add one to the address of the instruction signaling the condition,
1580 located in the sigargs array. */
1582 CHF$MECH_ARRAY * mechargs = (CHF$MECH_ARRAY *) ucontext;
1583 CHF$SIGNAL_ARRAY * sigargs
1584 = (CHF$SIGNAL_ARRAY *) mechargs->chf$q_mch_sig_addr;
1586 int vcount = sigargs->chf$is_sig_args;
1587 int * pc_slot = & (&sigargs->chf$l_sig_name)[vcount-2];
1594 /* __gnat_adjust_context_for_raise for ia64. */
1596 #if defined (IN_RTS) && defined (__IA64)
1598 #include <vms/chfctxdef.h>
1599 #include <vms/chfdef.h>
1601 #define HAVE_GNAT_ADJUST_CONTEXT_FOR_RAISE
1603 typedef unsigned long long u64;
1606 __gnat_adjust_context_for_raise (int signo ATTRIBUTE_UNUSED, void *ucontext)
1608 /* Add one to the address of the instruction signaling the condition,
1609 located in the 64bits sigargs array. */
1611 CHF$MECH_ARRAY * mechargs = (CHF$MECH_ARRAY *) ucontext;
1613 CHF64$SIGNAL_ARRAY *chfsig64
1614 = (CHF64$SIGNAL_ARRAY *) mechargs->chf$ph_mch_sig64_addr;
1617 = (u64 *)chfsig64 + 1 + chfsig64->chf64$l_sig_args;
1619 u64 * ih_pc_loc = post_sigarray - 2;
1626 /* Feature logical name and global variable address pair */
1627 struct feature {char *name; int* gl_addr;};
1629 /* Default values for GNAT features set by environment. */
1630 int __gl_no_malloc_64 = 0;
1632 /* Array feature logical names and global variable addresses */
1633 static struct feature features[] = {
1634 {"GNAT$NO_MALLOC_64", &__gl_no_malloc_64},
1638 void __gnat_set_features ()
1640 struct descriptor_s name_desc, result_desc;
1642 unsigned short rlen;
1645 char buff [MAXEQUIV];
1647 /* Loop through features array and test name for enable/disable */
1648 for (i=0; features [i].name; i++)
1650 name_desc.len = strlen (features [i].name);
1652 name_desc.adr = features [i].name;
1654 result_desc.len = MAXEQUIV - 1;
1655 result_desc.mbz = 0;
1656 result_desc.adr = buff;
1658 status = LIB$GET_LOGICAL (&name_desc, &result_desc, &rlen);
1660 if (((status & 1) == 1) && (rlen < MAXEQUIV))
1665 if (strcmp (buff, "ENABLE") == 0)
1666 *features [i].gl_addr = 1;
1667 else if (strcmp (buff, "DISABLE") == 0)
1668 *features [i].gl_addr = 0;
1671 __gnat_features_set = 1;
1674 /*******************/
1675 /* FreeBSD Section */
1676 /*******************/
1678 #elif defined (__FreeBSD__)
1681 #include <sys/ucontext.h>
1684 static void __gnat_error_handler (int, siginfo_t *, ucontext_t *);
1687 __gnat_error_handler (int sig, siginfo_t *info __attribute__ ((unused)),
1688 ucontext_t *ucontext)
1690 struct Exception_Data *exception;
1696 exception = &constraint_error;
1701 exception = &constraint_error;
1706 exception = &storage_error;
1707 msg = "stack overflow or erroneous memory access";
1711 exception = &constraint_error;
1716 exception = &program_error;
1717 msg = "unhandled signal";
1720 Raise_From_Signal_Handler (exception, msg);
1724 __gnat_install_handler ()
1726 struct sigaction act;
1728 /* Set up signal handler to map synchronous signals to appropriate
1729 exceptions. Make sure that the handler isn't interrupted by another
1730 signal that might cause a scheduling event! */
1733 = (void (*)(int, struct __siginfo *, void*)) __gnat_error_handler;
1734 act.sa_flags = SA_NODEFER | SA_RESTART | SA_SIGINFO;
1735 (void) sigemptyset (&act.sa_mask);
1737 (void) sigaction (SIGILL, &act, NULL);
1738 (void) sigaction (SIGFPE, &act, NULL);
1739 (void) sigaction (SIGSEGV, &act, NULL);
1740 (void) sigaction (SIGBUS, &act, NULL);
1742 __gnat_handler_installed = 1;
1745 /*******************/
1746 /* VxWorks Section */
1747 /*******************/
1749 #elif defined(__vxworks)
1752 #include <taskLib.h>
1760 #include "private/vThreadsP.h"
1763 void __gnat_error_handler (int, void *, struct sigcontext *);
1767 /* Directly vectored Interrupt routines are not supported when using RTPs. */
1769 extern int __gnat_inum_to_ivec (int);
1771 /* This is needed by the GNAT run time to handle Vxworks interrupts. */
1773 __gnat_inum_to_ivec (int num)
1775 return INUM_TO_IVEC (num);
1779 #if !defined(__alpha_vxworks) && (_WRS_VXWORKS_MAJOR != 6) && !defined(__RTP__)
1781 /* getpid is used by s-parint.adb, but is not defined by VxWorks, except
1782 on Alpha VxWorks and VxWorks 6.x (including RTPs). */
1784 extern long getpid (void);
1789 return taskIdSelf ();
1793 /* VxWorks expects the field excCnt to be zeroed when a signal is handled.
1794 The VxWorks version of longjmp does this; GCC's builtin_longjmp doesn't. */
1796 __gnat_clear_exception_count (void)
1799 WIND_TCB *currentTask = (WIND_TCB *) taskIdSelf();
1801 currentTask->vThreads.excCnt = 0;
1805 /* Handle different SIGnal to exception mappings in different VxWorks
1808 __gnat_map_signal (int sig)
1810 struct Exception_Data *exception;
1816 exception = &constraint_error;
1821 exception = &constraint_error;
1822 msg = "Floating point exception or SIGILL";
1825 exception = &storage_error;
1826 msg = "SIGSEGV: possible stack overflow";
1829 exception = &storage_error;
1830 msg = "SIGBUS: possible stack overflow";
1834 /* In RTP mode a SIGSEGV is most likely due to a stack overflow,
1835 since stack checking uses the probing mechanism. */
1837 exception = &constraint_error;
1841 exception = &storage_error;
1842 msg = "SIGSEGV: possible stack overflow";
1845 /* In kernel mode a SIGILL is most likely due to a stack overflow,
1846 since stack checking uses the stack limit mechanism. */
1848 exception = &storage_error;
1849 msg = "SIGILL: possible stack overflow";
1852 exception = &program_error;
1857 exception = &program_error;
1862 exception = &program_error;
1863 msg = "unhandled signal";
1866 __gnat_clear_exception_count ();
1867 Raise_From_Signal_Handler (exception, msg);
1870 /* Tasking and Non-tasking signal handler. Map SIGnal to Ada exception
1871 propagation after the required low level adjustments. */
1874 __gnat_error_handler (int sig, void * si ATTRIBUTE_UNUSED,
1875 struct sigcontext * sc)
1879 /* VxWorks will always mask out the signal during the signal handler and
1880 will reenable it on a longjmp. GNAT does not generate a longjmp to
1881 return from a signal handler so the signal will still be masked unless
1883 sigprocmask (SIG_SETMASK, NULL, &mask);
1884 sigdelset (&mask, sig);
1885 sigprocmask (SIG_SETMASK, &mask, NULL);
1887 __gnat_map_signal (sig);
1891 __gnat_install_handler (void)
1893 struct sigaction act;
1895 /* Setup signal handler to map synchronous signals to appropriate
1896 exceptions. Make sure that the handler isn't interrupted by another
1897 signal that might cause a scheduling event! */
1899 act.sa_handler = __gnat_error_handler;
1900 act.sa_flags = SA_SIGINFO | SA_ONSTACK;
1901 sigemptyset (&act.sa_mask);
1903 /* For VxWorks, install all signal handlers, since pragma Interrupt_State
1904 applies to vectored hardware interrupts, not signals. */
1905 sigaction (SIGFPE, &act, NULL);
1906 sigaction (SIGILL, &act, NULL);
1907 sigaction (SIGSEGV, &act, NULL);
1908 sigaction (SIGBUS, &act, NULL);
1910 __gnat_handler_installed = 1;
1913 #define HAVE_GNAT_INIT_FLOAT
1916 __gnat_init_float (void)
1918 /* Disable overflow/underflow exceptions on the PPC processor, needed
1919 to get correct Ada semantics. Note that for AE653 vThreads, the HW
1920 overflow settings are an OS configuration issue. The instructions
1921 below have no effect. */
1922 #if defined (_ARCH_PPC) && !defined (_SOFT_FLOAT) && !defined (VTHREADS)
1927 #if (defined (__i386__) || defined (i386)) && !defined (VTHREADS)
1928 /* This is used to properly initialize the FPU on an x86 for each
1933 /* Similarly for SPARC64. Achieved by masking bits in the Trap Enable Mask
1934 field of the Floating-point Status Register (see the SPARC Architecture
1935 Manual Version 9, p 48). */
1936 #if defined (sparc64)
1938 #define FSR_TEM_NVM (1 << 27) /* Invalid operand */
1939 #define FSR_TEM_OFM (1 << 26) /* Overflow */
1940 #define FSR_TEM_UFM (1 << 25) /* Underflow */
1941 #define FSR_TEM_DZM (1 << 24) /* Division by Zero */
1942 #define FSR_TEM_NXM (1 << 23) /* Inexact result */
1946 __asm__("st %%fsr, %0" : "=m" (fsr));
1947 fsr &= ~(FSR_TEM_OFM | FSR_TEM_UFM);
1948 __asm__("ld %0, %%fsr" : : "m" (fsr));
1953 /* This subprogram is called by System.Task_Primitives.Operations.Enter_Task
1954 (if not null) when a new task is created. It is initialized by
1955 System.Stack_Checking.Operations.Initialize_Stack_Limit.
1956 The use of a hook avoids to drag stack checking subprograms if stack
1957 checking is not used. */
1958 void (*__gnat_set_stack_limit_hook)(void) = (void (*)(void))0;
1961 /******************/
1962 /* NetBSD Section */
1963 /******************/
1965 #elif defined(__NetBSD__)
1971 __gnat_error_handler (int sig)
1973 struct Exception_Data *exception;
1979 exception = &constraint_error;
1983 exception = &constraint_error;
1987 exception = &storage_error;
1988 msg = "stack overflow or erroneous memory access";
1991 exception = &constraint_error;
1995 exception = &program_error;
1996 msg = "unhandled signal";
1999 Raise_From_Signal_Handler(exception, msg);
2003 __gnat_install_handler(void)
2005 struct sigaction act;
2007 act.sa_handler = __gnat_error_handler;
2008 act.sa_flags = SA_NODEFER | SA_RESTART;
2009 sigemptyset (&act.sa_mask);
2011 /* Do not install handlers if interrupt state is "System". */
2012 if (__gnat_get_interrupt_state (SIGFPE) != 's')
2013 sigaction (SIGFPE, &act, NULL);
2014 if (__gnat_get_interrupt_state (SIGILL) != 's')
2015 sigaction (SIGILL, &act, NULL);
2016 if (__gnat_get_interrupt_state (SIGSEGV) != 's')
2017 sigaction (SIGSEGV, &act, NULL);
2018 if (__gnat_get_interrupt_state (SIGBUS) != 's')
2019 sigaction (SIGBUS, &act, NULL);
2021 __gnat_handler_installed = 1;
2024 /*******************/
2025 /* OpenBSD Section */
2026 /*******************/
2028 #elif defined(__OpenBSD__)
2034 __gnat_error_handler (int sig)
2036 struct Exception_Data *exception;
2042 exception = &constraint_error;
2046 exception = &constraint_error;
2050 exception = &storage_error;
2051 msg = "stack overflow or erroneous memory access";
2054 exception = &constraint_error;
2058 exception = &program_error;
2059 msg = "unhandled signal";
2062 Raise_From_Signal_Handler(exception, msg);
2066 __gnat_install_handler(void)
2068 struct sigaction act;
2070 act.sa_handler = __gnat_error_handler;
2071 act.sa_flags = SA_NODEFER | SA_RESTART;
2072 sigemptyset (&act.sa_mask);
2074 /* Do not install handlers if interrupt state is "System" */
2075 if (__gnat_get_interrupt_state (SIGFPE) != 's')
2076 sigaction (SIGFPE, &act, NULL);
2077 if (__gnat_get_interrupt_state (SIGILL) != 's')
2078 sigaction (SIGILL, &act, NULL);
2079 if (__gnat_get_interrupt_state (SIGSEGV) != 's')
2080 sigaction (SIGSEGV, &act, NULL);
2081 if (__gnat_get_interrupt_state (SIGBUS) != 's')
2082 sigaction (SIGBUS, &act, NULL);
2084 __gnat_handler_installed = 1;
2089 /* For all other versions of GNAT, the handler does nothing. */
2091 /*******************/
2092 /* Default Section */
2093 /*******************/
2096 __gnat_install_handler (void)
2098 __gnat_handler_installed = 1;
2103 /*********************/
2104 /* __gnat_init_float */
2105 /*********************/
2107 /* This routine is called as each process thread is created, for possible
2108 initialization of the FP processor. This version is used under INTERIX,
2109 WIN32 and could be used under OS/2. */
2111 #if defined (_WIN32) || defined (__INTERIX) || defined (__EMX__) \
2112 || defined (__Lynx__) || defined(__NetBSD__) || defined(__FreeBSD__) \
2113 || defined (__OpenBSD__)
2115 #define HAVE_GNAT_INIT_FLOAT
2118 __gnat_init_float (void)
2120 #if defined (__i386__) || defined (i386)
2122 /* This is used to properly initialize the FPU on an x86 for each
2127 #endif /* Defined __i386__ */
2131 #ifndef HAVE_GNAT_INIT_FLOAT
2133 /* All targets without a specific __gnat_init_float will use an empty one. */
2135 __gnat_init_float (void)
2140 /***********************************/
2141 /* __gnat_adjust_context_for_raise */
2142 /***********************************/
2144 #ifndef HAVE_GNAT_ADJUST_CONTEXT_FOR_RAISE
2146 /* All targets without a specific version will use an empty one. */
2148 /* Given UCONTEXT a pointer to a context structure received by a signal
2149 handler for SIGNO, perform the necessary adjustments to let the handler
2150 raise an exception. Calls to this routine are not conditioned by the
2151 propagation scheme in use. */
2154 __gnat_adjust_context_for_raise (int signo ATTRIBUTE_UNUSED,
2155 void *ucontext ATTRIBUTE_UNUSED)
2157 /* We used to compensate here for the raised from call vs raised from signal
2158 exception discrepancy with the GCC ZCX scheme, but this is now dealt with
2159 generically (except for the Alpha and IA-64), see GCC PR other/26208.
2161 *** Call vs signal exception discrepancy with GCC ZCX scheme ***
2163 The GCC unwinder expects to be dealing with call return addresses, since
2164 this is the "nominal" case of what we retrieve while unwinding a regular
2167 To evaluate if a handler applies at some point identified by a return
2168 address, the propagation engine needs to determine what region the
2169 corresponding call instruction pertains to. Because the return address
2170 may not be attached to the same region as the call, the unwinder always
2171 subtracts "some" amount from a return address to search the region
2172 tables, amount chosen to ensure that the resulting address is inside the
2175 When we raise an exception from a signal handler, e.g. to transform a
2176 SIGSEGV into Storage_Error, things need to appear as if the signal
2177 handler had been "called" by the instruction which triggered the signal,
2178 so that exception handlers that apply there are considered. What the
2179 unwinder will retrieve as the return address from the signal handler is
2180 what it will find as the faulting instruction address in the signal
2181 context pushed by the kernel. Leaving this address untouched looses, if
2182 the triggering instruction happens to be the very first of a region, as
2183 the later adjustments performed by the unwinder would yield an address
2184 outside that region. We need to compensate for the unwinder adjustments
2185 at some point, and this is what this routine is expected to do.
2187 signo is passed because on some targets for some signals the PC in
2188 context points to the instruction after the faulting one, in which case
2189 the unwinder adjustment is still desired. */