1 /****************************************************************************
3 * GNAT COMPILER COMPONENTS *
7 * C Implementation File *
9 * Copyright (C) 1992-2013, 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. */
60 /* We don't have libiberty, so use malloc. */
61 #define xmalloc(S) malloc (S)
74 extern void __gnat_raise_program_error (const char *, int);
76 /* Addresses of exception data blocks for predefined exceptions. Tasking_Error
77 is not used in this unit, and the abort signal is only used on IRIX.
78 ??? Revisit this part since IRIX is no longer supported. */
79 extern struct Exception_Data constraint_error
;
80 extern struct Exception_Data numeric_error
;
81 extern struct Exception_Data program_error
;
82 extern struct Exception_Data storage_error
;
84 /* For the Cert run time we use the regular raise exception routine because
85 Raise_From_Signal_Handler is not available. */
87 #define Raise_From_Signal_Handler \
88 __gnat_raise_exception
89 extern void Raise_From_Signal_Handler (struct Exception_Data
*, const char *);
91 #define Raise_From_Signal_Handler \
92 ada__exceptions__raise_from_signal_handler
93 extern void Raise_From_Signal_Handler (struct Exception_Data
*, const char *);
96 /* Global values computed by the binder. */
97 int __gl_main_priority
= -1;
98 int __gl_main_cpu
= -1;
99 int __gl_time_slice_val
= -1;
100 char __gl_wc_encoding
= 'n';
101 char __gl_locking_policy
= ' ';
102 char __gl_queuing_policy
= ' ';
103 char __gl_task_dispatching_policy
= ' ';
104 char *__gl_priority_specific_dispatching
= 0;
105 int __gl_num_specific_dispatching
= 0;
106 char *__gl_interrupt_states
= 0;
107 int __gl_num_interrupt_states
= 0;
108 int __gl_unreserve_all_interrupts
= 0;
109 int __gl_exception_tracebacks
= 0;
110 int __gl_detect_blocking
= 0;
111 int __gl_default_stack_size
= -1;
112 int __gl_leap_seconds_support
= 0;
113 int __gl_canonical_streams
= 0;
115 /* This value is not used anymore, but kept for bootstrapping purpose. */
116 int __gl_zero_cost_exceptions
= 0;
118 /* Indication of whether synchronous signal handler has already been
119 installed by a previous call to adainit. */
120 int __gnat_handler_installed
= 0;
123 int __gnat_inside_elab_final_code
= 0;
124 /* ??? This variable is obsolete since 2001-08-29 but is kept to allow
125 bootstrap from old GNAT versions (< 3.15). */
128 /* HAVE_GNAT_INIT_FLOAT must be set on every targets where a __gnat_init_float
129 is defined. If this is not set then a void implementation will be defined
130 at the end of this unit. */
131 #undef HAVE_GNAT_INIT_FLOAT
133 /******************************/
134 /* __gnat_get_interrupt_state */
135 /******************************/
137 char __gnat_get_interrupt_state (int);
139 /* This routine is called from the runtime as needed to determine the state
140 of an interrupt, as set by an Interrupt_State pragma appearing anywhere
141 in the current partition. The input argument is the interrupt number,
142 and the result is one of the following:
144 'n' this interrupt not set by any Interrupt_State pragma
145 'u' Interrupt_State pragma set state to User
146 'r' Interrupt_State pragma set state to Runtime
147 's' Interrupt_State pragma set state to System */
150 __gnat_get_interrupt_state (int intrup
)
152 if (intrup
>= __gl_num_interrupt_states
)
155 return __gl_interrupt_states
[intrup
];
158 /***********************************/
159 /* __gnat_get_specific_dispatching */
160 /***********************************/
162 char __gnat_get_specific_dispatching (int);
164 /* This routine is called from the runtime as needed to determine the
165 priority specific dispatching policy, as set by a
166 Priority_Specific_Dispatching pragma appearing anywhere in the current
167 partition. The input argument is the priority number, and the result
168 is the upper case first character of the policy name, e.g. 'F' for
169 FIFO_Within_Priorities. A space ' ' is returned if no
170 Priority_Specific_Dispatching pragma is used in the partition. */
173 __gnat_get_specific_dispatching (int priority
)
175 if (__gl_num_specific_dispatching
== 0)
177 else if (priority
>= __gl_num_specific_dispatching
)
180 return __gl_priority_specific_dispatching
[priority
];
185 /**********************/
186 /* __gnat_set_globals */
187 /**********************/
189 /* This routine is kept for bootstrapping purposes, since the binder generated
190 file now sets the __gl_* variables directly. */
193 __gnat_set_globals (void)
206 #include <sys/time.h>
208 /* Some versions of AIX don't define SA_NODEFER. */
212 #endif /* SA_NODEFER */
214 /* Versions of AIX before 4.3 don't have nanosleep but provide
217 #ifndef _AIXVERSION_430
219 extern int nanosleep (struct timestruc_t
*, struct timestruc_t
*);
222 nanosleep (struct timestruc_t
*Rqtp
, struct timestruc_t
*Rmtp
)
224 return nsleep (Rqtp
, Rmtp
);
227 #endif /* _AIXVERSION_430 */
230 __gnat_error_handler (int sig
,
231 siginfo_t
*si ATTRIBUTE_UNUSED
,
232 void *ucontext ATTRIBUTE_UNUSED
)
234 struct Exception_Data
*exception
;
240 /* FIXME: we need to detect the case of a *real* SIGSEGV. */
241 exception
= &storage_error
;
242 msg
= "stack overflow or erroneous memory access";
246 exception
= &constraint_error
;
251 exception
= &constraint_error
;
256 exception
= &program_error
;
257 msg
= "unhandled signal";
260 Raise_From_Signal_Handler (exception
, msg
);
264 __gnat_install_handler (void)
266 struct sigaction act
;
268 /* Set up signal handler to map synchronous signals to appropriate
269 exceptions. Make sure that the handler isn't interrupted by another
270 signal that might cause a scheduling event! */
272 act
.sa_flags
= SA_NODEFER
| SA_RESTART
| SA_SIGINFO
;
273 act
.sa_sigaction
= __gnat_error_handler
;
274 sigemptyset (&act
.sa_mask
);
276 /* Do not install handlers if interrupt state is "System". */
277 if (__gnat_get_interrupt_state (SIGABRT
) != 's')
278 sigaction (SIGABRT
, &act
, NULL
);
279 if (__gnat_get_interrupt_state (SIGFPE
) != 's')
280 sigaction (SIGFPE
, &act
, NULL
);
281 if (__gnat_get_interrupt_state (SIGILL
) != 's')
282 sigaction (SIGILL
, &act
, NULL
);
283 if (__gnat_get_interrupt_state (SIGSEGV
) != 's')
284 sigaction (SIGSEGV
, &act
, NULL
);
285 if (__gnat_get_interrupt_state (SIGBUS
) != 's')
286 sigaction (SIGBUS
, &act
, NULL
);
288 __gnat_handler_installed
= 1;
295 #elif defined (__hpux__)
298 #include <sys/ucontext.h>
300 #if defined (IN_RTS) && defined (__ia64__)
302 #include <sys/uc_access.h>
304 #define HAVE_GNAT_ADJUST_CONTEXT_FOR_RAISE
307 __gnat_adjust_context_for_raise (int signo ATTRIBUTE_UNUSED
, void *ucontext
)
309 ucontext_t
*uc
= (ucontext_t
*) ucontext
;
312 /* Adjust on itanium, as GetIPInfo is not supported. */
313 __uc_get_ip (uc
, &ip
);
314 __uc_set_ip (uc
, ip
+ 1);
316 #endif /* IN_RTS && __ia64__ */
318 /* Tasking and Non-tasking signal handler. Map SIGnal to Ada exception
319 propagation after the required low level adjustments. */
322 __gnat_error_handler (int sig
,
323 siginfo_t
*si ATTRIBUTE_UNUSED
,
324 void *ucontext ATTRIBUTE_UNUSED
)
326 struct Exception_Data
*exception
;
329 __gnat_adjust_context_for_raise (sig
, ucontext
);
334 /* FIXME: we need to detect the case of a *real* SIGSEGV. */
335 exception
= &storage_error
;
336 msg
= "stack overflow or erroneous memory access";
340 exception
= &constraint_error
;
345 exception
= &constraint_error
;
350 exception
= &program_error
;
351 msg
= "unhandled signal";
354 Raise_From_Signal_Handler (exception
, msg
);
357 /* This must be in keeping with System.OS_Interface.Alternate_Stack_Size. */
358 #if defined (__hppa__)
359 char __gnat_alternate_stack
[16 * 1024]; /* 2 * SIGSTKSZ */
361 char __gnat_alternate_stack
[128 * 1024]; /* MINSIGSTKSZ */
365 __gnat_install_handler (void)
367 struct sigaction act
;
369 /* Set up signal handler to map synchronous signals to appropriate
370 exceptions. Make sure that the handler isn't interrupted by another
371 signal that might cause a scheduling event! Also setup an alternate
372 stack region for the handler execution so that stack overflows can be
373 handled properly, avoiding a SEGV generation from stack usage by the
377 stack
.ss_sp
= __gnat_alternate_stack
;
378 stack
.ss_size
= sizeof (__gnat_alternate_stack
);
380 sigaltstack (&stack
, NULL
);
382 act
.sa_sigaction
= __gnat_error_handler
;
383 act
.sa_flags
= SA_NODEFER
| SA_RESTART
| SA_SIGINFO
;
384 sigemptyset (&act
.sa_mask
);
386 /* Do not install handlers if interrupt state is "System". */
387 if (__gnat_get_interrupt_state (SIGABRT
) != 's')
388 sigaction (SIGABRT
, &act
, NULL
);
389 if (__gnat_get_interrupt_state (SIGFPE
) != 's')
390 sigaction (SIGFPE
, &act
, NULL
);
391 if (__gnat_get_interrupt_state (SIGILL
) != 's')
392 sigaction (SIGILL
, &act
, NULL
);
393 if (__gnat_get_interrupt_state (SIGBUS
) != 's')
394 sigaction (SIGBUS
, &act
, NULL
);
395 act
.sa_flags
|= SA_ONSTACK
;
396 if (__gnat_get_interrupt_state (SIGSEGV
) != 's')
397 sigaction (SIGSEGV
, &act
, NULL
);
399 __gnat_handler_installed
= 1;
402 /*********************/
403 /* GNU/Linux Section */
404 /*********************/
406 #elif defined (linux)
410 #define __USE_GNU 1 /* required to get REG_EIP/RIP from glibc's ucontext.h */
411 #include <sys/ucontext.h>
413 /* GNU/Linux, which uses glibc, does not define NULL in included
417 #define NULL ((void *) 0)
422 /* MaRTE OS provides its own version of sigaction, sigfillset, and
423 sigemptyset (overriding these symbol names). We want to make sure that
424 the versions provided by the underlying C library are used here (these
425 versions are renamed by MaRTE to linux_sigaction, fake_linux_sigfillset,
426 and fake_linux_sigemptyset, respectively). The MaRTE library will not
427 always be present (it will not be linked if no tasking constructs are
428 used), so we use the weak symbol mechanism to point always to the symbols
429 defined within the C library. */
431 #pragma weak linux_sigaction
432 int linux_sigaction (int signum
, const struct sigaction
*act
,
433 struct sigaction
*oldact
)
435 return sigaction (signum
, act
, oldact
);
437 #define sigaction(signum, act, oldact) linux_sigaction (signum, act, oldact)
439 #pragma weak fake_linux_sigfillset
440 void fake_linux_sigfillset (sigset_t
*set
)
444 #define sigfillset(set) fake_linux_sigfillset (set)
446 #pragma weak fake_linux_sigemptyset
447 void fake_linux_sigemptyset (sigset_t
*set
)
451 #define sigemptyset(set) fake_linux_sigemptyset (set)
455 #if defined (i386) || defined (__x86_64__) || defined (__ia64__) \
456 || defined (__ARMEL__)
458 #define HAVE_GNAT_ADJUST_CONTEXT_FOR_RAISE
461 __gnat_adjust_context_for_raise (int signo ATTRIBUTE_UNUSED
, void *ucontext
)
463 mcontext_t
*mcontext
= &((ucontext_t
*) ucontext
)->uc_mcontext
;
465 /* On the i386 and x86-64 architectures, stack checking is performed by
466 means of probes with moving stack pointer, that is to say the probed
467 address is always the value of the stack pointer. Upon hitting the
468 guard page, the stack pointer therefore points to an inaccessible
469 address and an alternate signal stack is needed to run the handler.
470 But there is an additional twist: on these architectures, the EH
471 return code writes the address of the handler at the target CFA's
472 value on the stack before doing the jump. As a consequence, if
473 there is an active handler in the frame whose stack has overflowed,
474 the stack pointer must nevertheless point to an accessible address
475 by the time the EH return is executed.
477 We therefore adjust the saved value of the stack pointer by the size
478 of one page + a small dope of 4 words, in order to make sure that it
479 points to an accessible address in case it's used as the target CFA.
480 The stack checking code guarantees that this address is unused by the
481 time this happens. */
484 unsigned long *pc
= (unsigned long *)mcontext
->gregs
[REG_EIP
];
485 /* The pattern is "orl $0x0,(%esp)" for a probe in 32-bit mode. */
486 if (signo
== SIGSEGV
&& pc
&& *pc
== 0x00240c83)
487 mcontext
->gregs
[REG_ESP
] += 4096 + 4 * sizeof (unsigned long);
488 #elif defined (__x86_64__)
489 unsigned long long *pc
= (unsigned long long *)mcontext
->gregs
[REG_RIP
];
490 if (signo
== SIGSEGV
&& pc
491 /* The pattern is "orq $0x0,(%rsp)" for a probe in 64-bit mode. */
492 && ((*pc
& 0xffffffffffLL
) == 0x00240c8348LL
493 /* The pattern may also be "orl $0x0,(%esp)" for a probe in
495 || (*pc
& 0xffffffffLL
) == 0x00240c83LL
))
496 mcontext
->gregs
[REG_RSP
] += 4096 + 4 * sizeof (unsigned long);
497 #elif defined (__ia64__)
498 /* ??? The IA-64 unwinder doesn't compensate for signals. */
500 #elif defined (__ARMEL__)
501 /* ARM Bump has to be an even number because of odd/even architecture. */
509 __gnat_error_handler (int sig
, siginfo_t
*si ATTRIBUTE_UNUSED
, void *ucontext
)
511 struct Exception_Data
*exception
;
514 /* Adjusting is required for every fault context, so adjust for this one
515 now, before we possibly trigger a recursive fault below. */
516 __gnat_adjust_context_for_raise (sig
, ucontext
);
521 /* Here we would like a discrimination test to see whether the page
522 before the faulting address is accessible. Unfortunately, Linux
523 seems to have no way of giving us the faulting address.
525 In old versions of init.c, we had a test of the page before the
529 ((long) si->esp_at_signal & - getpagesize ()))[getpagesize ()];
531 but that's wrong since it tests the stack pointer location and the
532 stack probing code may not move it until all probes succeed.
534 For now we simply do not attempt any discrimination at all. Note
535 that this is quite acceptable, since a "real" SIGSEGV can only
536 occur as the result of an erroneous program. */
537 exception
= &storage_error
;
538 msg
= "stack overflow or erroneous memory access";
542 exception
= &storage_error
;
543 msg
= "SIGBUS: possible stack overflow";
547 exception
= &constraint_error
;
552 exception
= &program_error
;
553 msg
= "unhandled signal";
556 Raise_From_Signal_Handler (exception
, msg
);
560 #define HAVE_GNAT_ALTERNATE_STACK 1
561 /* This must be in keeping with System.OS_Interface.Alternate_Stack_Size.
562 It must be larger than MINSIGSTKSZ and hopefully near 2 * SIGSTKSZ. */
563 # if 16 * 1024 < MINSIGSTKSZ
564 # error "__gnat_alternate_stack too small"
566 char __gnat_alternate_stack
[16 * 1024];
570 #include <sys/mman.h>
571 #include <native/task.h>
577 __gnat_install_handler (void)
579 struct sigaction act
;
584 if (__gl_main_priority
== -1)
587 prio
= __gl_main_priority
;
589 /* Avoid memory swapping for this program */
591 mlockall (MCL_CURRENT
|MCL_FUTURE
);
593 /* Turn the current Linux task into a native Xenomai task */
595 rt_task_shadow (&main_task
, "environment_task", prio
, T_FPU
);
598 /* Set up signal handler to map synchronous signals to appropriate
599 exceptions. Make sure that the handler isn't interrupted by another
600 signal that might cause a scheduling event! Also setup an alternate
601 stack region for the handler execution so that stack overflows can be
602 handled properly, avoiding a SEGV generation from stack usage by the
605 act
.sa_sigaction
= __gnat_error_handler
;
606 act
.sa_flags
= SA_NODEFER
| SA_RESTART
| SA_SIGINFO
;
607 sigemptyset (&act
.sa_mask
);
609 /* Do not install handlers if interrupt state is "System". */
610 if (__gnat_get_interrupt_state (SIGABRT
) != 's')
611 sigaction (SIGABRT
, &act
, NULL
);
612 if (__gnat_get_interrupt_state (SIGFPE
) != 's')
613 sigaction (SIGFPE
, &act
, NULL
);
614 if (__gnat_get_interrupt_state (SIGILL
) != 's')
615 sigaction (SIGILL
, &act
, NULL
);
616 if (__gnat_get_interrupt_state (SIGBUS
) != 's')
617 sigaction (SIGBUS
, &act
, NULL
);
618 if (__gnat_get_interrupt_state (SIGSEGV
) != 's')
620 #ifdef HAVE_GNAT_ALTERNATE_STACK
621 /* Setup an alternate stack region for the handler execution so that
622 stack overflows can be handled properly, avoiding a SEGV generation
623 from stack usage by the handler itself. */
626 stack
.ss_sp
= __gnat_alternate_stack
;
627 stack
.ss_size
= sizeof (__gnat_alternate_stack
);
629 sigaltstack (&stack
, NULL
);
631 act
.sa_flags
|= SA_ONSTACK
;
633 sigaction (SIGSEGV
, &act
, NULL
);
636 __gnat_handler_installed
= 1;
639 /*******************/
641 /*******************/
643 #elif defined (__Lynx__)
649 __gnat_error_handler (int sig
)
651 struct Exception_Data
*exception
;
657 exception
= &constraint_error
;
661 exception
= &constraint_error
;
665 exception
= &storage_error
;
666 msg
= "stack overflow or erroneous memory access";
669 exception
= &constraint_error
;
673 exception
= &program_error
;
674 msg
= "unhandled signal";
677 Raise_From_Signal_Handler(exception
, msg
);
681 __gnat_install_handler(void)
683 struct sigaction act
;
685 act
.sa_handler
= __gnat_error_handler
;
687 sigemptyset (&act
.sa_mask
);
689 /* Do not install handlers if interrupt state is "System". */
690 if (__gnat_get_interrupt_state (SIGFPE
) != 's')
691 sigaction (SIGFPE
, &act
, NULL
);
692 if (__gnat_get_interrupt_state (SIGILL
) != 's')
693 sigaction (SIGILL
, &act
, NULL
);
694 if (__gnat_get_interrupt_state (SIGSEGV
) != 's')
695 sigaction (SIGSEGV
, &act
, NULL
);
696 if (__gnat_get_interrupt_state (SIGBUS
) != 's')
697 sigaction (SIGBUS
, &act
, NULL
);
699 __gnat_handler_installed
= 1;
702 /*******************/
703 /* Solaris Section */
704 /*******************/
706 #elif defined (sun) && defined (__SVR4) && !defined (__vxworks)
710 #include <sys/ucontext.h>
711 #include <sys/regset.h>
714 __gnat_error_handler (int sig
, siginfo_t
*si
, void *ucontext ATTRIBUTE_UNUSED
)
716 struct Exception_Data
*exception
;
717 static int recurse
= 0;
723 /* If the problem was permissions, this is a constraint error.
724 Likewise if the failing address isn't maximally aligned or if
727 ??? Using a static variable here isn't task-safe, but it's
728 much too hard to do anything else and we're just determining
729 which exception to raise. */
730 if (si
->si_code
== SEGV_ACCERR
731 || (long) si
->si_addr
== 0
732 || (((long) si
->si_addr
) & 3) != 0
735 exception
= &constraint_error
;
740 /* See if the page before the faulting page is accessible. Do that
741 by trying to access it. We'd like to simply try to access
742 4096 + the faulting address, but it's not guaranteed to be
743 the actual address, just to be on the same page. */
746 ((long) si
->si_addr
& - getpagesize ()))[getpagesize ()];
747 exception
= &storage_error
;
748 msg
= "stack overflow or erroneous memory access";
753 exception
= &program_error
;
758 exception
= &constraint_error
;
763 exception
= &program_error
;
764 msg
= "unhandled signal";
768 Raise_From_Signal_Handler (exception
, msg
);
772 __gnat_install_handler (void)
774 struct sigaction act
;
776 /* Set up signal handler to map synchronous signals to appropriate
777 exceptions. Make sure that the handler isn't interrupted by another
778 signal that might cause a scheduling event! */
780 act
.sa_sigaction
= __gnat_error_handler
;
781 act
.sa_flags
= SA_NODEFER
| SA_RESTART
| SA_SIGINFO
;
782 sigemptyset (&act
.sa_mask
);
784 /* Do not install handlers if interrupt state is "System". */
785 if (__gnat_get_interrupt_state (SIGABRT
) != 's')
786 sigaction (SIGABRT
, &act
, NULL
);
787 if (__gnat_get_interrupt_state (SIGFPE
) != 's')
788 sigaction (SIGFPE
, &act
, NULL
);
789 if (__gnat_get_interrupt_state (SIGSEGV
) != 's')
790 sigaction (SIGSEGV
, &act
, NULL
);
791 if (__gnat_get_interrupt_state (SIGBUS
) != 's')
792 sigaction (SIGBUS
, &act
, NULL
);
794 __gnat_handler_installed
= 1;
803 /* Routine called from binder to override default feature values. */
804 void __gnat_set_features (void);
805 int __gnat_features_set
= 0;
806 void (*__gnat_ctrl_c_handler
) (void) = 0;
809 #define lib_get_curr_invo_context LIB$I64_GET_CURR_INVO_CONTEXT
810 #define lib_get_prev_invo_context LIB$I64_GET_PREV_INVO_CONTEXT
811 #define lib_get_invo_handle LIB$I64_GET_INVO_HANDLE
813 #define lib_get_curr_invo_context LIB$GET_CURR_INVO_CONTEXT
814 #define lib_get_prev_invo_context LIB$GET_PREV_INVO_CONTEXT
815 #define lib_get_invo_handle LIB$GET_INVO_HANDLE
818 /* Masks for facility identification. */
819 #define FAC_MASK 0x0fff0000
820 #define DECADA_M_FACILITY 0x00310000
822 /* Define macro symbols for the VMS conditions that become Ada exceptions.
823 It would be better to just include <ssdef.h> */
825 #define SS$_CONTINUE 1
826 #define SS$_ACCVIO 12
827 #define SS$_HPARITH 1284
828 #define SS$_INTDIV 1156
829 #define SS$_STKOVF 1364
830 #define SS$_CONTROLC 1617
831 #define SS$_RESIGNAL 2328
833 #define MTH$_FLOOVEMAT 1475268 /* Some ACVC_21 CXA tests */
835 /* The following codes must be resignalled, and not handled here. */
837 /* These codes are in standard message libraries. */
838 extern int C$_SIGKILL
;
839 extern int C$_SIGINT
;
840 extern int SS$_DEBUG
;
841 extern int LIB$_KEYNOTFOU
;
842 extern int LIB$_ACTIMAGE
;
844 /* These codes are non standard, which is to say the author is
845 not sure if they are defined in the standard message libraries
846 so keep them as macros for now. */
847 #define RDB$_STREAM_EOF 20480426
848 #define FDL$_UNPRIKW 11829410
849 #define CMA$_EXIT_THREAD 4227492
854 unsigned int sigargval
;
860 const struct cond_sigargs sigargs
[];
866 const struct Exception_Data
*except
;
867 unsigned int needs_adjust
; /* 1 = adjust PC, 0 = no adjust */
868 const struct cond_subtests
*subtests
;
873 unsigned short len
, mbz
;
877 /* Conditions that don't have an Ada exception counterpart must raise
878 Non_Ada_Error. Since this is defined in s-auxdec, it should only be
879 referenced by user programs, not the compiler or tools. Hence the
884 #define Status_Error ada__io_exceptions__status_error
885 extern struct Exception_Data Status_Error
;
887 #define Mode_Error ada__io_exceptions__mode_error
888 extern struct Exception_Data Mode_Error
;
890 #define Name_Error ada__io_exceptions__name_error
891 extern struct Exception_Data Name_Error
;
893 #define Use_Error ada__io_exceptions__use_error
894 extern struct Exception_Data Use_Error
;
896 #define Device_Error ada__io_exceptions__device_error
897 extern struct Exception_Data Device_Error
;
899 #define End_Error ada__io_exceptions__end_error
900 extern struct Exception_Data End_Error
;
902 #define Data_Error ada__io_exceptions__data_error
903 extern struct Exception_Data Data_Error
;
905 #define Layout_Error ada__io_exceptions__layout_error
906 extern struct Exception_Data Layout_Error
;
908 #define Non_Ada_Error system__aux_dec__non_ada_error
909 extern struct Exception_Data Non_Ada_Error
;
911 #define Coded_Exception system__vms_exception_table__coded_exception
912 extern struct Exception_Data
*Coded_Exception (void *);
914 #define Base_Code_In system__vms_exception_table__base_code_in
915 extern void *Base_Code_In (void *);
917 /* DEC Ada exceptions are not defined in a header file, so they
920 #define ADA$_ALREADY_OPEN 0x0031a594
921 #define ADA$_CONSTRAINT_ERRO 0x00318324
922 #define ADA$_DATA_ERROR 0x003192c4
923 #define ADA$_DEVICE_ERROR 0x003195e4
924 #define ADA$_END_ERROR 0x00319904
925 #define ADA$_FAC_MODE_MISMAT 0x0031a8b3
926 #define ADA$_IOSYSFAILED 0x0031af04
927 #define ADA$_KEYSIZERR 0x0031aa3c
928 #define ADA$_KEY_MISMATCH 0x0031a8e3
929 #define ADA$_LAYOUT_ERROR 0x00319c24
930 #define ADA$_LINEXCMRS 0x0031a8f3
931 #define ADA$_MAXLINEXC 0x0031a8eb
932 #define ADA$_MODE_ERROR 0x00319f44
933 #define ADA$_MRN_MISMATCH 0x0031a8db
934 #define ADA$_MRS_MISMATCH 0x0031a8d3
935 #define ADA$_NAME_ERROR 0x0031a264
936 #define ADA$_NOT_OPEN 0x0031a58c
937 #define ADA$_ORG_MISMATCH 0x0031a8bb
938 #define ADA$_PROGRAM_ERROR 0x00318964
939 #define ADA$_RAT_MISMATCH 0x0031a8cb
940 #define ADA$_RFM_MISMATCH 0x0031a8c3
941 #define ADA$_STAOVF 0x00318cac
942 #define ADA$_STATUS_ERROR 0x0031a584
943 #define ADA$_STORAGE_ERROR 0x00318c84
944 #define ADA$_UNSUPPORTED 0x0031a8ab
945 #define ADA$_USE_ERROR 0x0031a8a4
947 /* DEC Ada specific conditions. */
948 static const struct cond_except dec_ada_cond_except_table
[] =
950 {ADA$_PROGRAM_ERROR
, &program_error
, 0, 0},
951 {ADA$_USE_ERROR
, &Use_Error
, 0, 0},
952 {ADA$_KEYSIZERR
, &program_error
, 0, 0},
953 {ADA$_STAOVF
, &storage_error
, 0, 0},
954 {ADA$_CONSTRAINT_ERRO
, &constraint_error
, 0, 0},
955 {ADA$_IOSYSFAILED
, &Device_Error
, 0, 0},
956 {ADA$_LAYOUT_ERROR
, &Layout_Error
, 0, 0},
957 {ADA$_STORAGE_ERROR
, &storage_error
, 0, 0},
958 {ADA$_DATA_ERROR
, &Data_Error
, 0, 0},
959 {ADA$_DEVICE_ERROR
, &Device_Error
, 0, 0},
960 {ADA$_END_ERROR
, &End_Error
, 0, 0},
961 {ADA$_MODE_ERROR
, &Mode_Error
, 0, 0},
962 {ADA$_NAME_ERROR
, &Name_Error
, 0, 0},
963 {ADA$_STATUS_ERROR
, &Status_Error
, 0, 0},
964 {ADA$_NOT_OPEN
, &Use_Error
, 0, 0},
965 {ADA$_ALREADY_OPEN
, &Use_Error
, 0, 0},
966 {ADA$_USE_ERROR
, &Use_Error
, 0, 0},
967 {ADA$_UNSUPPORTED
, &Use_Error
, 0, 0},
968 {ADA$_FAC_MODE_MISMAT
, &Use_Error
, 0, 0},
969 {ADA$_ORG_MISMATCH
, &Use_Error
, 0, 0},
970 {ADA$_RFM_MISMATCH
, &Use_Error
, 0, 0},
971 {ADA$_RAT_MISMATCH
, &Use_Error
, 0, 0},
972 {ADA$_MRS_MISMATCH
, &Use_Error
, 0, 0},
973 {ADA$_MRN_MISMATCH
, &Use_Error
, 0, 0},
974 {ADA$_KEY_MISMATCH
, &Use_Error
, 0, 0},
975 {ADA$_MAXLINEXC
, &constraint_error
, 0, 0},
976 {ADA$_LINEXCMRS
, &constraint_error
, 0, 0},
979 /* Already handled by a pragma Import_Exception
980 in Aux_IO_Exceptions */
981 {ADA$_LOCK_ERROR
, &Lock_Error
, 0, 0},
982 {ADA$_EXISTENCE_ERROR
, &Existence_Error
, 0, 0},
983 {ADA$_KEY_ERROR
, &Key_Error
, 0, 0},
991 /* Non-DEC Ada specific conditions that map to Ada exceptions. */
993 /* Subtest for ACCVIO Constraint_Error, kept for compatibility,
994 in hindsight should have just made ACCVIO == Storage_Error. */
995 #define ACCVIO_VIRTUAL_ADDR 3
996 static const struct cond_subtests accvio_c_e
=
997 {1, /* number of subtests below */
999 { ACCVIO_VIRTUAL_ADDR
, 0 }
1003 /* Macro flag to adjust PC which gets off by one for some conditions,
1004 not sure if this is reliably true, PC could be off by more for
1005 HPARITH for example, unless a trapb is inserted. */
1006 #define NEEDS_ADJUST 1
1008 static const struct cond_except system_cond_except_table
[] =
1010 {MTH$_FLOOVEMAT
, &constraint_error
, 0, 0},
1011 {SS$_INTDIV
, &constraint_error
, 0, 0},
1012 {SS$_HPARITH
, &constraint_error
, NEEDS_ADJUST
, 0},
1013 {SS$_ACCVIO
, &constraint_error
, NEEDS_ADJUST
, &accvio_c_e
},
1014 {SS$_ACCVIO
, &storage_error
, NEEDS_ADJUST
, 0},
1015 {SS$_STKOVF
, &storage_error
, NEEDS_ADJUST
, 0},
1019 /* To deal with VMS conditions and their mapping to Ada exceptions,
1020 the __gnat_error_handler routine below is installed as an exception
1021 vector having precedence over DEC frame handlers. Some conditions
1022 still need to be handled by such handlers, however, in which case
1023 __gnat_error_handler needs to return SS$_RESIGNAL. Consider for
1024 instance the use of a third party library compiled with DECAda and
1025 performing its own exception handling internally.
1027 To allow some user-level flexibility, which conditions should be
1028 resignaled is controlled by a predicate function, provided with the
1029 condition value and returning a boolean indication stating whether
1030 this condition should be resignaled or not.
1032 That predicate function is called indirectly, via a function pointer,
1033 by __gnat_error_handler, and changing that pointer is allowed to the
1034 user code by way of the __gnat_set_resignal_predicate interface.
1036 The user level function may then implement what it likes, including
1037 for instance the maintenance of a dynamic data structure if the set
1038 of to be resignalled conditions has to change over the program's
1041 ??? This is not a perfect solution to deal with the possible
1042 interactions between the GNAT and the DECAda exception handling
1043 models and better (more general) schemes are studied. This is so
1044 just provided as a convenient workaround in the meantime, and
1045 should be use with caution since the implementation has been kept
1048 typedef int resignal_predicate (int code
);
1050 static const int * const cond_resignal_table
[] =
1053 (int *)CMA$_EXIT_THREAD
,
1057 (int *) RDB$_STREAM_EOF
,
1058 (int *) FDL$_UNPRIKW
,
1062 static const int facility_resignal_table
[] =
1064 0x1380000, /* RDB */
1065 0x2220000, /* SQL */
1069 /* Default GNAT predicate for resignaling conditions. */
1072 __gnat_default_resignal_p (int code
)
1076 for (i
= 0; facility_resignal_table
[i
]; i
++)
1077 if ((code
& FAC_MASK
) == facility_resignal_table
[i
])
1080 for (i
= 0, iexcept
= 0;
1081 cond_resignal_table
[i
]
1082 && !(iexcept
= LIB$
MATCH_COND (&code
, &cond_resignal_table
[i
]));
1088 /* Static pointer to predicate that the __gnat_error_handler exception
1089 vector invokes to determine if it should resignal a condition. */
1091 static resignal_predicate
*__gnat_resignal_p
= __gnat_default_resignal_p
;
1093 /* User interface to change the predicate pointer to PREDICATE. Reset to
1094 the default if PREDICATE is null. */
1097 __gnat_set_resignal_predicate (resignal_predicate
*predicate
)
1099 if (predicate
== NULL
)
1100 __gnat_resignal_p
= __gnat_default_resignal_p
;
1102 __gnat_resignal_p
= predicate
;
1105 /* Should match System.Parameters.Default_Exception_Msg_Max_Length. */
1106 #define Default_Exception_Msg_Max_Length 512
1108 /* Action routine for SYS$PUTMSG. There may be multiple
1109 conditions, each with text to be appended to MESSAGE
1110 and separated by line termination. */
1112 copy_msg (struct descriptor_s
*msgdesc
, char *message
)
1114 int len
= strlen (message
);
1117 /* Check for buffer overflow and skip. */
1118 if (len
> 0 && len
<= Default_Exception_Msg_Max_Length
- 3)
1120 strcat (message
, "\r\n");
1124 /* Check for buffer overflow and truncate if necessary. */
1125 copy_len
= (len
+ msgdesc
->len
<= Default_Exception_Msg_Max_Length
- 1 ?
1127 Default_Exception_Msg_Max_Length
- 1 - len
);
1128 strncpy (&message
[len
], msgdesc
->adr
, copy_len
);
1129 message
[len
+ copy_len
] = 0;
1134 /* Scan TABLE for a match for the condition contained in SIGARGS,
1135 and return the entry, or the empty entry if no match found. */
1136 static const struct cond_except
*
1137 scan_conditions ( int *sigargs
, const struct cond_except
*table
[])
1140 struct cond_except entry
;
1142 /* Scan the exception condition table for a match and fetch
1143 the associated GNAT exception pointer. */
1144 for (i
= 0; (*table
) [i
].cond
; i
++)
1146 unsigned int match
= LIB$
MATCH_COND (&sigargs
[1], &(*table
) [i
].cond
);
1147 const struct cond_subtests
*subtests
= (*table
) [i
].subtests
;
1153 return &(*table
) [i
];
1158 int num
= (*subtests
).num
;
1160 /* Perform subtests to differentiate exception. */
1161 for (ii
= 0; ii
< num
; ii
++)
1163 unsigned int arg
= (*subtests
).sigargs
[ii
].sigarg
;
1164 unsigned int argval
= (*subtests
).sigargs
[ii
].sigargval
;
1166 if (sigargs
[arg
] != argval
)
1173 /* All subtests passed. */
1174 if (num
== (*subtests
).num
)
1175 return &(*table
) [i
];
1180 /* No match, return the null terminating entry. */
1181 return &(*table
) [i
];
1184 /* __gnat_handle_vms_condtition is both a frame based handler
1185 for the runtime, and an exception vector for the compiler. */
1187 __gnat_handle_vms_condition (int *sigargs
, void *mechargs
)
1189 struct Exception_Data
*exception
= 0;
1190 unsigned int needs_adjust
= 0;
1192 struct descriptor_s gnat_facility
= {4, 0, "GNAT"};
1193 char message
[Default_Exception_Msg_Max_Length
];
1195 const char *msg
= "";
1197 /* Check for conditions to resignal which aren't effected by pragma
1198 Import_Exception. */
1199 if (__gnat_resignal_p (sigargs
[1]))
1200 return SS$_RESIGNAL
;
1202 /* toplev.c handles this for compiler. */
1203 if (sigargs
[1] == SS$_HPARITH
)
1204 return SS$_RESIGNAL
;
1208 /* See if it's an imported exception. Beware that registered exceptions
1209 are bound to their base code, with the severity bits masked off. */
1210 base_code
= Base_Code_In ((void *) sigargs
[1]);
1211 exception
= Coded_Exception (base_code
);
1218 struct cond_except cond
;
1219 const struct cond_except
*cond_table
;
1220 const struct cond_except
*cond_tables
[] = {dec_ada_cond_except_table
,
1221 system_cond_except_table
,
1223 unsigned int ctrlc
= SS$_CONTROLC
;
1224 unsigned int *sigint
= &C$_SIGINT
;
1225 int ctrlc_match
= LIB$
MATCH_COND (&sigargs
[1], &ctrlc
);
1226 int sigint_match
= LIB$
MATCH_COND (&sigargs
[1], &sigint
);
1228 extern int SYS$
DCLAST (void (*astadr
)(), unsigned long long astprm
,
1229 unsigned int acmode
);
1231 /* If SS$_CONTROLC has been imported as an exception, it will take
1232 priority over a a Ctrl/C handler. See above. SIGINT has a
1233 different condition value due to it's DECCCRTL roots and it's
1234 the condition that gets raised for a "kill -INT". */
1235 if ((ctrlc_match
|| sigint_match
) && __gnat_ctrl_c_handler
)
1237 SYS$
DCLAST (__gnat_ctrl_c_handler
, 0, 0);
1238 return SS$_CONTINUE
;
1242 while ((cond_table
= cond_tables
[i
++]) && !exception
)
1244 cond
= *scan_conditions (sigargs
, &cond_table
);
1245 exception
= (struct Exception_Data
*) cond
.except
;
1249 needs_adjust
= cond
.needs_adjust
;
1251 /* User programs expect Non_Ada_Error to be raised if no match,
1252 reference DEC Ada test CXCONDHAN. */
1253 exception
= &Non_Ada_Error
;
1257 /* Pretty much everything is just a program error in the compiler */
1258 exception
= &program_error
;
1263 /* Subtract PC & PSL fields as per ABI for SYS$PUTMSG. */
1266 extern int SYS$
PUTMSG (void *, int (*)(), void *, unsigned long long);
1268 /* If it was a DEC Ada specific condtiion, make it GNAT otherwise
1269 keep the old facility. */
1270 if (sigargs
[1] & FAC_MASK
== DECADA_M_FACILITY
)
1271 SYS$
PUTMSG (sigargs
, copy_msg
, &gnat_facility
,
1272 (unsigned long long ) message
);
1274 SYS$
PUTMSG (sigargs
, copy_msg
, 0,
1275 (unsigned long long ) message
);
1277 /* Add back PC & PSL fields as per ABI for SYS$PUTMSG. */
1282 __gnat_adjust_context_for_raise (sigargs
[1], (void *)mechargs
);
1284 Raise_From_Signal_Handler (exception
, msg
);
1287 #if defined (IN_RTS) && defined (__IA64)
1288 /* Called only from adasigio.b32. This is a band aid to avoid going
1289 through the VMS signal handling code which results in a 0x8000 per
1290 handled exception memory leak in P2 space (see VMS source listing
1291 sys/lis/exception.lis) due to the allocation of working space that
1292 is expected to be deallocated upon return from the condition handler,
1293 which doesn't return in GNAT compiled code. */
1295 GNAT$
STOP (int *sigargs
)
1297 /* Note that there are no mechargs. We rely on the fact that condtions
1298 raised from DEClib I/O do not require an "adjust". Also the count
1299 will be off by 2, since LIB$STOP didn't get a chance to add the
1300 PC and PSL fields, so we bump it so PUTMSG comes out right. */
1302 __gnat_handle_vms_condition (sigargs
, 0);
1307 __gnat_install_handler (void)
1309 long prvhnd ATTRIBUTE_UNUSED
;
1311 #if !defined (IN_RTS)
1312 extern int SYS$
SETEXV (unsigned int vector
, int (*addres
)(),
1313 unsigned int accmode
, void *(*(prvhnd
)));
1314 SYS$
SETEXV (1, __gnat_handle_vms_condition
, 3, &prvhnd
);
1317 __gnat_handler_installed
= 1;
1320 /* __gnat_adjust_context_for_raise for Alpha - see comments along with the
1321 default version later in this file. */
1323 #if defined (IN_RTS) && defined (__alpha__)
1325 #include <vms/chfctxdef.h>
1326 #include <vms/chfdef.h>
1328 #define HAVE_GNAT_ADJUST_CONTEXT_FOR_RAISE
1331 __gnat_adjust_context_for_raise (int signo ATTRIBUTE_UNUSED
, void *ucontext
)
1333 if (signo
== SS$_HPARITH
)
1335 /* Sub one to the address of the instruction signaling the condition,
1336 located in the sigargs array. */
1338 CHF$MECH_ARRAY
* mechargs
= (CHF$MECH_ARRAY
*) ucontext
;
1339 CHF$SIGNAL_ARRAY
* sigargs
1340 = (CHF$SIGNAL_ARRAY
*) mechargs
->chf$q_mch_sig_addr
;
1342 int vcount
= sigargs
->chf$is_sig_args
;
1343 int * pc_slot
= & (&sigargs
->chf$l_sig_name
)[vcount
-2];
1351 /* __gnat_adjust_context_for_raise for ia64. */
1353 #if defined (IN_RTS) && defined (__IA64)
1355 #include <vms/chfctxdef.h>
1356 #include <vms/chfdef.h>
1358 #define HAVE_GNAT_ADJUST_CONTEXT_FOR_RAISE
1360 typedef unsigned long long u64
;
1363 __gnat_adjust_context_for_raise (int signo ATTRIBUTE_UNUSED
, void *ucontext
)
1365 /* Add one to the address of the instruction signaling the condition,
1366 located in the 64bits sigargs array. */
1368 CHF$MECH_ARRAY
* mechargs
= (CHF$MECH_ARRAY
*) ucontext
;
1370 CHF64$SIGNAL_ARRAY
*chfsig64
1371 = (CHF64$SIGNAL_ARRAY
*) mechargs
->chf$ph_mch_sig64_addr
;
1374 = (u64
*)chfsig64
+ 1 + chfsig64
->chf64$l_sig_args
;
1376 u64
* ih_pc_loc
= post_sigarray
- 2;
1383 /* Easier interface for LIB$GET_LOGICAL: put the equivalence of NAME into BUF,
1384 always NUL terminated. In case of error or if the result is longer than
1385 LEN (length of BUF) an empty string is written info BUF. */
1388 __gnat_vms_get_logical (const char *name
, char *buf
, int len
)
1390 struct descriptor_s name_desc
, result_desc
;
1392 unsigned short rlen
;
1394 /* Build the descriptor for NAME. */
1395 name_desc
.len
= strlen (name
);
1397 name_desc
.adr
= (char *)name
;
1399 /* Build the descriptor for the result. */
1400 result_desc
.len
= len
;
1401 result_desc
.mbz
= 0;
1402 result_desc
.adr
= buf
;
1404 status
= LIB$
GET_LOGICAL (&name_desc
, &result_desc
, &rlen
);
1406 if ((status
& 1) == 1 && rlen
< len
)
1412 /* Size of a page on ia64 and alpha VMS. */
1413 #define VMS_PAGESIZE 8192
1416 #define PSL__C_USER 3
1421 /* Descending region. */
1422 #define VA__M_DESCEND 1
1424 /* Get by virtual address. */
1425 #define VA___REGSUM_BY_VA 1
1427 /* Memory region summary. */
1430 unsigned long long q_region_id
;
1431 unsigned int l_flags
;
1432 unsigned int l_region_protection
;
1434 unsigned long long q_region_size
;
1435 void *pq_first_free_va
;
1438 extern int SYS$
GET_REGION_INFO (unsigned int, unsigned long long *,
1439 void *, void *, unsigned int,
1440 void *, unsigned int *);
1441 extern int SYS$
EXPREG_64 (unsigned long long *, unsigned long long,
1442 unsigned int, unsigned int, void **,
1443 unsigned long long *);
1444 extern int SYS$
SETPRT_64 (void *, unsigned long long, unsigned int,
1445 unsigned int, void **, unsigned long long *,
1448 /* Add a guard page in the memory region containing ADDR at ADDR +/- SIZE.
1449 (The sign depends on the kind of the memory region). */
1452 __gnat_set_stack_guard_page (void *addr
, unsigned long size
)
1456 unsigned long long ret_len
;
1457 unsigned int ret_prot
;
1459 unsigned long long length
;
1460 unsigned int retlen
;
1461 struct regsum buffer
;
1463 /* Get the region for ADDR. */
1464 status
= SYS$GET_REGION_INFO
1465 (VA___REGSUM_BY_VA
, NULL
, addr
, NULL
, sizeof (buffer
), &buffer
, &retlen
);
1467 if ((status
& 1) != 1)
1470 /* Extend the region. */
1471 status
= SYS$
EXPREG_64 (&buffer
.q_region_id
,
1472 size
, 0, 0, &start_va
, &length
);
1474 if ((status
& 1) != 1)
1477 /* Create a guard page. */
1478 if (!(buffer
.l_flags
& VA__M_DESCEND
))
1479 start_va
= (void *)((unsigned long long)start_va
+ length
- VMS_PAGESIZE
);
1481 status
= SYS$
SETPRT_64 (start_va
, VMS_PAGESIZE
, PSL__C_USER
, PRT__C_NA
,
1482 &ret_va
, &ret_len
, &ret_prot
);
1484 if ((status
& 1) != 1)
1489 /* Read logicals to limit the stack(s) size. */
1492 __gnat_set_stack_limit (void)
1500 /* The main stack. */
1501 __gnat_vms_get_logical ("GNAT_STACK_SIZE", value
, sizeof (value
));
1502 size
= strtoul (value
, &e
, 0);
1503 if (e
> value
&& *e
== 0)
1505 asm ("mov %0=sp" : "=r" (sp
));
1506 __gnat_set_stack_guard_page (sp
, size
* 1024);
1509 /* The register stack. */
1510 __gnat_vms_get_logical ("GNAT_RBS_SIZE", value
, sizeof (value
));
1511 size
= strtoul (value
, &e
, 0);
1512 if (e
> value
&& *e
== 0)
1514 asm ("mov %0=ar.bsp" : "=r" (sp
));
1515 __gnat_set_stack_guard_page (sp
, size
* 1024);
1521 extern int SYS$
IEEE_SET_FP_CONTROL (void *, void *, void *);
1523 #define __int64 long long
1524 #define __NEW_STARLET
1525 #include <vms/ieeedef.h>
1528 /* Feature logical name and global variable address pair.
1529 If we ever add another feature logical to this list, the
1530 feature struct will need to be enhanced to take into account
1531 possible values for *gl_addr. */
1537 /* Default values for GNAT features set by environment or binder. */
1538 int __gl_heap_size
= 64;
1540 /* Default float format is 'I' meaning IEEE. If gnatbind detetcts that a
1541 VAX Float format is specified, it will set this global variable to 'V'.
1542 Subsequently __gnat_set_features will test the variable and if set for
1543 VAX Float will call a Starlet function to enable trapping for invalid
1544 operation, drivide by zero, and overflow. This will prevent the VMS runtime
1545 (specifically OTS$CHECK_FP_MODE) from complaining about inconsistent
1546 floating point settings in a mixed language program. Ideally the setting
1547 would be determined at link time based on setttings in the object files,
1548 however the VMS linker seems to take the setting from the first object
1549 in the link, e.g. pcrt0.o which is float representation neutral. */
1550 char __gl_float_format
= 'I';
1552 /* Array feature logical names and global variable addresses. */
1553 static const struct feature features
[] =
1555 {"GNAT$NO_MALLOC_64", &__gl_heap_size
},
1560 __gnat_set_features (void)
1565 IEEE clrmsk
, setmsk
, prvmsk
;
1567 clrmsk
.ieee$q_flags
= 0LL;
1568 setmsk
.ieee$q_flags
= 0LL;
1571 /* Loop through features array and test name for enable/disable. */
1572 for (i
= 0; features
[i
].name
; i
++)
1574 __gnat_vms_get_logical (features
[i
].name
, buff
, sizeof (buff
));
1576 if (strcmp (buff
, "ENABLE") == 0
1577 || strcmp (buff
, "TRUE") == 0
1578 || strcmp (buff
, "1") == 0)
1579 *features
[i
].gl_addr
= 32;
1580 else if (strcmp (buff
, "DISABLE") == 0
1581 || strcmp (buff
, "FALSE") == 0
1582 || strcmp (buff
, "0") == 0)
1583 *features
[i
].gl_addr
= 64;
1586 /* Features to artificially limit the stack size. */
1587 __gnat_set_stack_limit ();
1590 if (__gl_float_format
== 'V')
1592 setmsk
.ieee$v_trap_enable_inv
= K_TRUE
;
1593 setmsk
.ieee$v_trap_enable_dze
= K_TRUE
;
1594 setmsk
.ieee$v_trap_enable_ovf
= K_TRUE
;
1595 SYS$
IEEE_SET_FP_CONTROL (&clrmsk
, &setmsk
, &prvmsk
);
1599 __gnat_features_set
= 1;
1602 /* Return true if the VMS version is 7.x. */
1604 extern unsigned int LIB$
GETSYI (int *, ...);
1606 #define SYI$_VERSION 0x1000
1609 __gnat_is_vms_v7 (void)
1611 struct descriptor_s desc
;
1614 int code
= SYI$_VERSION
;
1616 desc
.len
= sizeof (version
);
1620 status
= LIB$
GETSYI (&code
, 0, &desc
);
1621 if ((status
& 1) == 1 && version
[1] == '7' && version
[2] == '.')
1627 /*******************/
1628 /* FreeBSD Section */
1629 /*******************/
1631 #elif defined (__FreeBSD__)
1634 #include <sys/ucontext.h>
1638 __gnat_error_handler (int sig
,
1639 siginfo_t
*si ATTRIBUTE_UNUSED
,
1640 void *ucontext ATTRIBUTE_UNUSED
)
1642 struct Exception_Data
*exception
;
1648 exception
= &constraint_error
;
1653 exception
= &constraint_error
;
1658 exception
= &storage_error
;
1659 msg
= "stack overflow or erroneous memory access";
1663 exception
= &storage_error
;
1664 msg
= "SIGBUS: possible stack overflow";
1668 exception
= &program_error
;
1669 msg
= "unhandled signal";
1672 Raise_From_Signal_Handler (exception
, msg
);
1676 __gnat_install_handler ()
1678 struct sigaction act
;
1680 /* Set up signal handler to map synchronous signals to appropriate
1681 exceptions. Make sure that the handler isn't interrupted by another
1682 signal that might cause a scheduling event! */
1685 = (void (*)(int, struct __siginfo
*, void*)) __gnat_error_handler
;
1686 act
.sa_flags
= SA_NODEFER
| SA_RESTART
| SA_SIGINFO
;
1687 (void) sigemptyset (&act
.sa_mask
);
1689 (void) sigaction (SIGILL
, &act
, NULL
);
1690 (void) sigaction (SIGFPE
, &act
, NULL
);
1691 (void) sigaction (SIGSEGV
, &act
, NULL
);
1692 (void) sigaction (SIGBUS
, &act
, NULL
);
1694 __gnat_handler_installed
= 1;
1697 /*******************/
1698 /* VxWorks Section */
1699 /*******************/
1701 #elif defined(__vxworks)
1704 #include <taskLib.h>
1711 #if defined (ARMEL) && (_WRS_VXWORKS_MAJOR == 6)
1716 #include "private/vThreadsP.h"
1721 /* Directly vectored Interrupt routines are not supported when using RTPs. */
1723 extern int __gnat_inum_to_ivec (int);
1725 /* This is needed by the GNAT run time to handle Vxworks interrupts. */
1727 __gnat_inum_to_ivec (int num
)
1729 return (int) INUM_TO_IVEC (num
);
1733 #if !defined(__alpha_vxworks) && (_WRS_VXWORKS_MAJOR != 6) && !defined(__RTP__)
1735 /* getpid is used by s-parint.adb, but is not defined by VxWorks, except
1736 on Alpha VxWorks and VxWorks 6.x (including RTPs). */
1738 extern long getpid (void);
1743 return taskIdSelf ();
1747 /* VxWorks 653 vThreads expects the field excCnt to be zeroed when a signal is.
1748 handled. The VxWorks version of longjmp does this; GCC's builtin_longjmp
1751 __gnat_clear_exception_count (void)
1754 WIND_TCB
*currentTask
= (WIND_TCB
*) taskIdSelf();
1756 currentTask
->vThreads
.excCnt
= 0;
1760 /* Handle different SIGnal to exception mappings in different VxWorks
1763 __gnat_map_signal (int sig
, siginfo_t
*si ATTRIBUTE_UNUSED
,
1764 void *sc ATTRIBUTE_UNUSED
)
1766 struct Exception_Data
*exception
;
1772 exception
= &constraint_error
;
1776 #ifdef __VXWORKSMILS__
1778 exception
= &storage_error
;
1779 msg
= "SIGILL: possible stack overflow";
1782 exception
= &storage_error
;
1786 exception
= &program_error
;
1791 exception
= &constraint_error
;
1792 msg
= "Floating point exception or SIGILL";
1795 exception
= &storage_error
;
1799 exception
= &storage_error
;
1800 msg
= "SIGBUS: possible stack overflow";
1803 #elif (_WRS_VXWORKS_MAJOR == 6)
1805 exception
= &constraint_error
;
1809 /* In RTP mode a SIGSEGV is most likely due to a stack overflow,
1810 since stack checking uses the probing mechanism. */
1812 exception
= &storage_error
;
1813 msg
= "SIGSEGV: possible stack overflow";
1816 exception
= &program_error
;
1820 /* VxWorks 6 kernel mode with probing. SIGBUS for guard page hit */
1822 exception
= &storage_error
;
1826 exception
= &storage_error
;
1827 msg
= "SIGBUS: possible stack overflow";
1831 /* VxWorks 5: a SIGILL is most likely due to a stack overflow,
1832 since stack checking uses the stack limit mechanism. */
1834 exception
= &storage_error
;
1835 msg
= "SIGILL: possible stack overflow";
1838 exception
= &storage_error
;
1842 exception
= &program_error
;
1847 exception
= &program_error
;
1848 msg
= "unhandled signal";
1851 /* On ARM VxWorks 6.x, the guard page is left un-armed by the kernel
1852 after being violated, so subsequent violations aren't detected.
1853 so we retrieve the address of the guard page from the TCB and compare it
1854 with the page that is violated (pREG 12 in the context) and re-arm that
1855 page if there's a match. Additionally we're are assured this is a
1856 genuine stack overflow condition and and set the message and exception
1858 #if defined (ARMEL) && (_WRS_VXWORKS_MAJOR == 6)
1860 /* We re-arm the guard page by marking it invalid */
1862 #define PAGE_SIZE 4096
1865 if (sig
== SIGSEGV
|| sig
== SIGBUS
|| sig
== SIGILL
)
1867 TASK_ID tid
= taskIdSelf ();
1868 WIND_TCB
*pTcb
= taskTcb (tid
);
1869 unsigned long violated_page
1870 = ((struct sigcontext
*) sc
)->sc_pregs
->r
[REG_IP
] & ~(PAGE_SIZE
- 1);
1872 if ((unsigned long) (pTcb
->pStackEnd
- PAGE_SIZE
) == violated_page
)
1874 vmStateSet (NULL
, violated_page
,
1875 PAGE_SIZE
, VM_STATE_MASK_VALID
, VM_STATE_VALID_NOT
);
1876 exception
= &storage_error
;
1881 msg
= "SIGSEGV: stack overflow";
1884 msg
= "SIGBUS: stack overflow";
1887 msg
= "SIGILL: stack overflow";
1892 #endif /* defined (ARMEL) && (_WRS_VXWORKS_MAJOR == 6) */
1894 __gnat_clear_exception_count ();
1895 Raise_From_Signal_Handler (exception
, msg
);
1898 /* Tasking and Non-tasking signal handler. Map SIGnal to Ada exception
1899 propagation after the required low level adjustments. */
1902 __gnat_error_handler (int sig
, siginfo_t
*si
, void *sc
)
1906 /* VxWorks will always mask out the signal during the signal handler and
1907 will reenable it on a longjmp. GNAT does not generate a longjmp to
1908 return from a signal handler so the signal will still be masked unless
1910 sigprocmask (SIG_SETMASK
, NULL
, &mask
);
1911 sigdelset (&mask
, sig
);
1912 sigprocmask (SIG_SETMASK
, &mask
, NULL
);
1914 #if (defined (__ARMEL__) || defined (__PPC__)) && defined(_WRS_KERNEL)
1915 /* On PowerPC, kernel mode, we process signals through a Call Frame Info
1916 trampoline, voiding the need for myriads of fallback_frame_state
1917 variants in the ZCX runtime. We have no simple way to distinguish ZCX
1918 from SJLJ here, so we do this for SJLJ as well even though this is not
1919 necessary. This only incurs a few extra instructions and a tiny
1920 amount of extra stack usage. */
1922 #include "sigtramp.h"
1924 __gnat_sigtramp (sig
, (void *)si
, (void *)sc
,
1925 (sighandler_t
*)&__gnat_map_signal
);
1928 __gnat_map_signal (sig
, si
, sc
);
1932 #if defined(__leon__) && defined(_WRS_KERNEL)
1933 /* For LEON VxWorks we need to install a trap handler for stack overflow */
1935 extern void excEnt (void);
1936 /* VxWorks exception handler entry */
1939 unsigned long inst_first
;
1940 unsigned long inst_second
;
1941 unsigned long inst_third
;
1942 unsigned long inst_fourth
;
1944 /* Four instructions representing entries in the trap table */
1946 struct trap_entry
*trap_0_entry
;
1947 /* We will set the location of the entry for software trap 0 in the trap
1952 __gnat_install_handler (void)
1954 struct sigaction act
;
1956 /* Setup signal handler to map synchronous signals to appropriate
1957 exceptions. Make sure that the handler isn't interrupted by another
1958 signal that might cause a scheduling event! */
1960 act
.sa_sigaction
= __gnat_error_handler
;
1961 act
.sa_flags
= SA_SIGINFO
| SA_ONSTACK
;
1962 sigemptyset (&act
.sa_mask
);
1964 /* For VxWorks, install all signal handlers, since pragma Interrupt_State
1965 applies to vectored hardware interrupts, not signals. */
1966 sigaction (SIGFPE
, &act
, NULL
);
1967 sigaction (SIGILL
, &act
, NULL
);
1968 sigaction (SIGSEGV
, &act
, NULL
);
1969 sigaction (SIGBUS
, &act
, NULL
);
1971 #if defined(__leon__) && defined(_WRS_KERNEL)
1972 /* Specific to the LEON VxWorks kernel run-time library */
1974 /* For stack checking the compiler triggers a software trap 0 (ta 0) in
1975 case of overflow (we use the stack limit mechanism). We need to install
1976 the trap handler here for this software trap (the OS does not handle
1977 it) as if it were a data_access_exception (trap 9). We do the same as
1978 if we put in the trap table a VXSPARC_BAD_TRAP(9). Software trap 0 is
1979 located at vector 0x80, and each entry takes 4 words. */
1981 trap_0_entry
= (struct trap_entry
*)(intVecBaseGet () + 0x80 * 4);
1985 trap_0_entry
->inst_first
= 0xae102000 + 9;
1987 /* sethi %hi(excEnt), %l6 */
1989 /* The 22 most significant bits of excEnt are obtained shifting 10 times
1992 trap_0_entry
->inst_second
= 0x2d000000 + ((unsigned long)excEnt
>> 10);
1994 /* jmp %l6+%lo(excEnt) */
1996 /* The 10 least significant bits of excEnt are obtained by masking */
1998 trap_0_entry
->inst_third
= 0x81c5a000 + ((unsigned long)excEnt
& 0x3ff);
2002 trap_0_entry
->inst_fourth
= 0xa1480000;
2005 __gnat_handler_installed
= 1;
2008 #define HAVE_GNAT_INIT_FLOAT
2011 __gnat_init_float (void)
2013 /* Disable overflow/underflow exceptions on the PPC processor, needed
2014 to get correct Ada semantics. Note that for AE653 vThreads, the HW
2015 overflow settings are an OS configuration issue. The instructions
2016 below have no effect. */
2017 #if defined (_ARCH_PPC) && !defined (_SOFT_FLOAT) && (!defined (VTHREADS) || defined (__VXWORKSMILS__))
2018 #if defined (__SPE__)
2020 const unsigned long spefscr_mask
= 0xfffffff3;
2021 unsigned long spefscr
;
2022 asm ("mfspr %0, 512" : "=r" (spefscr
));
2023 spefscr
= spefscr
& spefscr_mask
;
2024 asm ("mtspr 512, %0\n\tisync" : : "r" (spefscr
));
2032 #if (defined (__i386__) || defined (i386)) && !defined (VTHREADS)
2033 /* This is used to properly initialize the FPU on an x86 for each
2038 /* Similarly for SPARC64. Achieved by masking bits in the Trap Enable Mask
2039 field of the Floating-point Status Register (see the SPARC Architecture
2040 Manual Version 9, p 48). */
2041 #if defined (sparc64)
2043 #define FSR_TEM_NVM (1 << 27) /* Invalid operand */
2044 #define FSR_TEM_OFM (1 << 26) /* Overflow */
2045 #define FSR_TEM_UFM (1 << 25) /* Underflow */
2046 #define FSR_TEM_DZM (1 << 24) /* Division by Zero */
2047 #define FSR_TEM_NXM (1 << 23) /* Inexact result */
2051 __asm__("st %%fsr, %0" : "=m" (fsr
));
2052 fsr
&= ~(FSR_TEM_OFM
| FSR_TEM_UFM
);
2053 __asm__("ld %0, %%fsr" : : "m" (fsr
));
2058 /* This subprogram is called by System.Task_Primitives.Operations.Enter_Task
2059 (if not null) when a new task is created. It is initialized by
2060 System.Stack_Checking.Operations.Initialize_Stack_Limit.
2061 The use of a hook avoids to drag stack checking subprograms if stack
2062 checking is not used. */
2063 void (*__gnat_set_stack_limit_hook
)(void) = (void (*)(void))0;
2065 /******************/
2066 /* NetBSD Section */
2067 /******************/
2069 #elif defined(__NetBSD__)
2075 __gnat_error_handler (int sig
)
2077 struct Exception_Data
*exception
;
2083 exception
= &constraint_error
;
2087 exception
= &constraint_error
;
2091 exception
= &storage_error
;
2092 msg
= "stack overflow or erroneous memory access";
2095 exception
= &constraint_error
;
2099 exception
= &program_error
;
2100 msg
= "unhandled signal";
2103 Raise_From_Signal_Handler(exception
, msg
);
2107 __gnat_install_handler(void)
2109 struct sigaction act
;
2111 act
.sa_handler
= __gnat_error_handler
;
2112 act
.sa_flags
= SA_NODEFER
| SA_RESTART
;
2113 sigemptyset (&act
.sa_mask
);
2115 /* Do not install handlers if interrupt state is "System". */
2116 if (__gnat_get_interrupt_state (SIGFPE
) != 's')
2117 sigaction (SIGFPE
, &act
, NULL
);
2118 if (__gnat_get_interrupt_state (SIGILL
) != 's')
2119 sigaction (SIGILL
, &act
, NULL
);
2120 if (__gnat_get_interrupt_state (SIGSEGV
) != 's')
2121 sigaction (SIGSEGV
, &act
, NULL
);
2122 if (__gnat_get_interrupt_state (SIGBUS
) != 's')
2123 sigaction (SIGBUS
, &act
, NULL
);
2125 __gnat_handler_installed
= 1;
2128 /*******************/
2129 /* OpenBSD Section */
2130 /*******************/
2132 #elif defined(__OpenBSD__)
2138 __gnat_error_handler (int sig
)
2140 struct Exception_Data
*exception
;
2146 exception
= &constraint_error
;
2150 exception
= &constraint_error
;
2154 exception
= &storage_error
;
2155 msg
= "stack overflow or erroneous memory access";
2158 exception
= &constraint_error
;
2162 exception
= &program_error
;
2163 msg
= "unhandled signal";
2166 Raise_From_Signal_Handler(exception
, msg
);
2170 __gnat_install_handler(void)
2172 struct sigaction act
;
2174 act
.sa_handler
= __gnat_error_handler
;
2175 act
.sa_flags
= SA_NODEFER
| SA_RESTART
;
2176 sigemptyset (&act
.sa_mask
);
2178 /* Do not install handlers if interrupt state is "System" */
2179 if (__gnat_get_interrupt_state (SIGFPE
) != 's')
2180 sigaction (SIGFPE
, &act
, NULL
);
2181 if (__gnat_get_interrupt_state (SIGILL
) != 's')
2182 sigaction (SIGILL
, &act
, NULL
);
2183 if (__gnat_get_interrupt_state (SIGSEGV
) != 's')
2184 sigaction (SIGSEGV
, &act
, NULL
);
2185 if (__gnat_get_interrupt_state (SIGBUS
) != 's')
2186 sigaction (SIGBUS
, &act
, NULL
);
2188 __gnat_handler_installed
= 1;
2191 /******************/
2192 /* Darwin Section */
2193 /******************/
2195 #elif defined(__APPLE__)
2199 #include <sys/syscall.h>
2200 #include <sys/sysctl.h>
2201 #include <mach/mach_vm.h>
2202 #include <mach/mach_init.h>
2203 #include <mach/vm_statistics.h>
2205 /* This must be in keeping with System.OS_Interface.Alternate_Stack_Size. */
2206 char __gnat_alternate_stack
[32 * 1024]; /* 1 * MINSIGSTKSZ */
2208 /* Defined in xnu unix_signal.c.
2209 Tell the kernel to re-use alt stack when delivering a signal. */
2210 #define UC_RESET_ALT_STACK 0x80000000
2212 /* Return true if ADDR is within a stack guard area. */
2214 __gnat_is_stack_guard (mach_vm_address_t addr
)
2217 vm_region_submap_info_data_64_t info
;
2218 mach_vm_address_t start
;
2219 mach_vm_size_t size
;
2221 mach_msg_type_number_t count
;
2223 count
= VM_REGION_SUBMAP_INFO_COUNT_64
;
2227 kret
= mach_vm_region_recurse (mach_task_self (), &start
, &size
, &depth
,
2228 (vm_region_recurse_info_t
) &info
, &count
);
2229 if (kret
== KERN_SUCCESS
2230 && addr
>= start
&& addr
< (start
+ size
)
2231 && info
.protection
== VM_PROT_NONE
2232 && info
.user_tag
== VM_MEMORY_STACK
)
2237 #define HAVE_GNAT_ADJUST_CONTEXT_FOR_RAISE
2239 #if defined (__x86_64__)
2241 __darwin_major_version (void)
2243 static int cache
= -1;
2246 int mib
[2] = {CTL_KERN
, KERN_OSRELEASE
};
2249 /* Find out how big the buffer needs to be (and set cache to 0
2251 if (sysctl (mib
, 2, NULL
, &len
, NULL
, 0) == 0)
2254 sysctl (mib
, 2, release
, &len
, NULL
, 0);
2255 /* Darwin releases are of the form L.M.N where L is the major
2256 version, so strtol will return L. */
2257 cache
= (int) strtol (release
, NULL
, 10);
2269 __gnat_adjust_context_for_raise (int signo ATTRIBUTE_UNUSED
,
2270 void *ucontext ATTRIBUTE_UNUSED
)
2272 #if defined (__x86_64__)
2273 if (__darwin_major_version () < 12)
2275 /* Work around radar #10302855, where the unwinders (libunwind or
2276 libgcc_s depending on the system revision) and the DWARF unwind
2277 data for sigtramp have different ideas about register numbering,
2278 causing rbx and rdx to be transposed. */
2279 ucontext_t
*uc
= (ucontext_t
*)ucontext
;
2280 unsigned long t
= uc
->uc_mcontext
->__ss
.__rbx
;
2282 uc
->uc_mcontext
->__ss
.__rbx
= uc
->uc_mcontext
->__ss
.__rdx
;
2283 uc
->uc_mcontext
->__ss
.__rdx
= t
;
2289 __gnat_error_handler (int sig
, siginfo_t
*si
, void *ucontext
)
2291 struct Exception_Data
*exception
;
2294 __gnat_adjust_context_for_raise (sig
, ucontext
);
2300 if (__gnat_is_stack_guard ((unsigned long)si
->si_addr
))
2302 exception
= &storage_error
;
2303 msg
= "stack overflow";
2307 exception
= &constraint_error
;
2308 msg
= "erroneous memory access";
2310 /* Reset the use of alt stack, so that the alt stack will be used
2311 for the next signal delivery.
2312 The stack can't be used in case of stack checking. */
2313 syscall (SYS_sigreturn
, NULL
, UC_RESET_ALT_STACK
);
2317 exception
= &constraint_error
;
2322 exception
= &program_error
;
2323 msg
= "unhandled signal";
2326 Raise_From_Signal_Handler (exception
, msg
);
2330 __gnat_install_handler (void)
2332 struct sigaction act
;
2334 /* Set up signal handler to map synchronous signals to appropriate
2335 exceptions. Make sure that the handler isn't interrupted by another
2336 signal that might cause a scheduling event! Also setup an alternate
2337 stack region for the handler execution so that stack overflows can be
2338 handled properly, avoiding a SEGV generation from stack usage by the
2339 handler itself (and it is required by Darwin). */
2342 stack
.ss_sp
= __gnat_alternate_stack
;
2343 stack
.ss_size
= sizeof (__gnat_alternate_stack
);
2345 sigaltstack (&stack
, NULL
);
2347 act
.sa_flags
= SA_NODEFER
| SA_RESTART
| SA_SIGINFO
;
2348 act
.sa_sigaction
= __gnat_error_handler
;
2349 sigemptyset (&act
.sa_mask
);
2351 /* Do not install handlers if interrupt state is "System". */
2352 if (__gnat_get_interrupt_state (SIGABRT
) != 's')
2353 sigaction (SIGABRT
, &act
, NULL
);
2354 if (__gnat_get_interrupt_state (SIGFPE
) != 's')
2355 sigaction (SIGFPE
, &act
, NULL
);
2356 if (__gnat_get_interrupt_state (SIGILL
) != 's')
2357 sigaction (SIGILL
, &act
, NULL
);
2359 act
.sa_flags
|= SA_ONSTACK
;
2360 if (__gnat_get_interrupt_state (SIGSEGV
) != 's')
2361 sigaction (SIGSEGV
, &act
, NULL
);
2362 if (__gnat_get_interrupt_state (SIGBUS
) != 's')
2363 sigaction (SIGBUS
, &act
, NULL
);
2365 __gnat_handler_installed
= 1;
2368 #elif defined(__ANDROID__)
2370 /*******************/
2371 /* Android Section */
2372 /*******************/
2378 __gnat_error_handler (int sig
,
2379 siginfo_t
*si ATTRIBUTE_UNUSED
,
2380 void *ucontext ATTRIBUTE_UNUSED
)
2382 struct Exception_Data
*exception
;
2388 exception
= &storage_error
;
2389 msg
= "stack overflow or erroneous memory access";
2393 exception
= &constraint_error
;
2398 exception
= &constraint_error
;
2403 exception
= &program_error
;
2404 msg
= "unhandled signal";
2407 Raise_From_Signal_Handler (exception
, msg
);
2410 /* This must be in keeping with System.OS_Interface.Alternate_Stack_Size. */
2411 char __gnat_alternate_stack
[16 * 1024];
2414 __gnat_install_handler (void)
2416 struct sigaction act
;
2418 /* Set up signal handler to map synchronous signals to appropriate
2419 exceptions. Make sure that the handler isn't interrupted by another
2420 signal that might cause a scheduling event! Also setup an alternate
2421 stack region for the handler execution so that stack overflows can be
2422 handled properly, avoiding a SEGV generation from stack usage by the
2426 stack
.ss_sp
= __gnat_alternate_stack
;
2427 stack
.ss_size
= sizeof (__gnat_alternate_stack
);
2429 sigaltstack (&stack
, NULL
);
2431 act
.sa_sigaction
= __gnat_error_handler
;
2432 act
.sa_flags
= SA_NODEFER
| SA_RESTART
| SA_SIGINFO
;
2433 sigemptyset (&act
.sa_mask
);
2435 sigaction (SIGABRT
, &act
, NULL
);
2436 sigaction (SIGFPE
, &act
, NULL
);
2437 sigaction (SIGILL
, &act
, NULL
);
2438 sigaction (SIGBUS
, &act
, NULL
);
2439 act
.sa_flags
|= SA_ONSTACK
;
2440 sigaction (SIGSEGV
, &act
, NULL
);
2442 __gnat_handler_installed
= 1;
2447 /* For all other versions of GNAT, the handler does nothing. */
2449 /*******************/
2450 /* Default Section */
2451 /*******************/
2454 __gnat_install_handler (void)
2456 __gnat_handler_installed
= 1;
2461 /*********************/
2462 /* __gnat_init_float */
2463 /*********************/
2465 /* This routine is called as each process thread is created, for possible
2466 initialization of the FP processor. This version is used under INTERIX
2469 #if defined (_WIN32) || defined (__INTERIX) \
2470 || defined (__Lynx__) || defined(__NetBSD__) || defined(__FreeBSD__) \
2471 || defined (__OpenBSD__)
2473 #define HAVE_GNAT_INIT_FLOAT
2476 __gnat_init_float (void)
2478 #if defined (__i386__) || defined (i386) || defined (__x86_64)
2480 /* This is used to properly initialize the FPU on an x86 for each
2485 #endif /* Defined __i386__ */
2489 #ifndef HAVE_GNAT_INIT_FLOAT
2491 /* All targets without a specific __gnat_init_float will use an empty one. */
2493 __gnat_init_float (void)
2498 /***********************************/
2499 /* __gnat_adjust_context_for_raise */
2500 /***********************************/
2502 #ifndef HAVE_GNAT_ADJUST_CONTEXT_FOR_RAISE
2504 /* All targets without a specific version will use an empty one. */
2506 /* Given UCONTEXT a pointer to a context structure received by a signal
2507 handler for SIGNO, perform the necessary adjustments to let the handler
2508 raise an exception. Calls to this routine are not conditioned by the
2509 propagation scheme in use. */
2512 __gnat_adjust_context_for_raise (int signo ATTRIBUTE_UNUSED
,
2513 void *ucontext ATTRIBUTE_UNUSED
)
2515 /* We used to compensate here for the raised from call vs raised from signal
2516 exception discrepancy with the GCC ZCX scheme, but this now can be dealt
2517 with generically in the unwinder (see GCC PR other/26208). This however
2518 requires the use of the _Unwind_GetIPInfo routine in raise-gcc.c, which
2519 is predicated on the definition of HAVE_GETIPINFO at compile time. Only
2520 the VMS ports still do the compensation described in the few lines below.
2522 *** Call vs signal exception discrepancy with GCC ZCX scheme ***
2524 The GCC unwinder expects to be dealing with call return addresses, since
2525 this is the "nominal" case of what we retrieve while unwinding a regular
2528 To evaluate if a handler applies at some point identified by a return
2529 address, the propagation engine needs to determine what region the
2530 corresponding call instruction pertains to. Because the return address
2531 may not be attached to the same region as the call, the unwinder always
2532 subtracts "some" amount from a return address to search the region
2533 tables, amount chosen to ensure that the resulting address is inside the
2536 When we raise an exception from a signal handler, e.g. to transform a
2537 SIGSEGV into Storage_Error, things need to appear as if the signal
2538 handler had been "called" by the instruction which triggered the signal,
2539 so that exception handlers that apply there are considered. What the
2540 unwinder will retrieve as the return address from the signal handler is
2541 what it will find as the faulting instruction address in the signal
2542 context pushed by the kernel. Leaving this address untouched looses, if
2543 the triggering instruction happens to be the very first of a region, as
2544 the later adjustments performed by the unwinder would yield an address
2545 outside that region. We need to compensate for the unwinder adjustments
2546 at some point, and this is what this routine is expected to do.
2548 signo is passed because on some targets for some signals the PC in
2549 context points to the instruction after the faulting one, in which case
2550 the unwinder adjustment is still desired. */