diff options
Diffstat (limited to 'gcc-4.7/gcc/ada/init.c')
| -rw-r--r-- | gcc-4.7/gcc/ada/init.c | 2511 |
1 files changed, 0 insertions, 2511 deletions
diff --git a/gcc-4.7/gcc/ada/init.c b/gcc-4.7/gcc/ada/init.c deleted file mode 100644 index 80a02b173..000000000 --- a/gcc-4.7/gcc/ada/init.c +++ /dev/null @@ -1,2511 +0,0 @@ -/**************************************************************************** - * * - * GNAT COMPILER COMPONENTS * - * * - * I N I T * - * * - * C Implementation File * - * * - * Copyright (C) 1992-2012, Free Software Foundation, Inc. * - * * - * GNAT is free software; you can redistribute it and/or modify it under * - * terms of the GNU General Public License as published by the Free Soft- * - * ware Foundation; either version 3, or (at your option) any later ver- * - * sion. GNAT is distributed in the hope that it will be useful, but WITH- * - * OUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY * - * or FITNESS FOR A PARTICULAR PURPOSE. * - * * - * As a special exception under Section 7 of GPL version 3, you are granted * - * additional permissions described in the GCC Runtime Library Exception, * - * version 3.1, as published by the Free Software Foundation. * - * * - * You should have received a copy of the GNU General Public License and * - * a copy of the GCC Runtime Library Exception along with this program; * - * see the files COPYING3 and COPYING.RUNTIME respectively. If not, see * - * <http://www.gnu.org/licenses/>. * - * * - * GNAT was originally developed by the GNAT team at New York University. * - * Extensive contributions were provided by Ada Core Technologies Inc. * - * * - ****************************************************************************/ - -/* This unit contains initialization circuits that are system dependent. - A major part of the functionality involves stack overflow checking. - The GCC backend generates probe instructions to test for stack overflow. - For details on the exact approach used to generate these probes, see the - "Using and Porting GCC" manual, in particular the "Stack Checking" section - and the subsection "Specifying How Stack Checking is Done". The handlers - installed by this file are used to catch the resulting signals that come - from these probes failing (i.e. touching protected pages). */ - -#ifdef __cplusplus -extern "C" { -#endif - -/* This file should be kept synchronized with 2sinit.ads, 2sinit.adb, - s-init-ae653-cert.adb and s-init-xi-sparc.adb. All these files implement - the required functionality for different targets. */ - -/* The following include is here to meet the published VxWorks requirement - that the __vxworks header appear before any other include. */ -#ifdef __vxworks -#include "vxWorks.h" -#endif - -#ifdef IN_RTS -#include "tconfig.h" -#include "tsystem.h" -#include <sys/stat.h> - -/* We don't have libiberty, so use malloc. */ -#define xmalloc(S) malloc (S) -#else -#include "config.h" -#include "system.h" -#endif - -#include "adaint.h" -#include "raise.h" - -extern void __gnat_raise_program_error (const char *, int); - -/* Addresses of exception data blocks for predefined exceptions. Tasking_Error - is not used in this unit, and the abort signal is only used on IRIX. */ -extern struct Exception_Data constraint_error; -extern struct Exception_Data numeric_error; -extern struct Exception_Data program_error; -extern struct Exception_Data storage_error; - -/* For the Cert run time we use the regular raise exception routine because - Raise_From_Signal_Handler is not available. */ -#ifdef CERT -#define Raise_From_Signal_Handler \ - __gnat_raise_exception -extern void Raise_From_Signal_Handler (struct Exception_Data *, const char *); -#else -#define Raise_From_Signal_Handler \ - ada__exceptions__raise_from_signal_handler -extern void Raise_From_Signal_Handler (struct Exception_Data *, const char *); -#endif - -/* Global values computed by the binder. */ -int __gl_main_priority = -1; -int __gl_main_cpu = -1; -int __gl_time_slice_val = -1; -char __gl_wc_encoding = 'n'; -char __gl_locking_policy = ' '; -char __gl_queuing_policy = ' '; -char __gl_task_dispatching_policy = ' '; -char *__gl_priority_specific_dispatching = 0; -int __gl_num_specific_dispatching = 0; -char *__gl_interrupt_states = 0; -int __gl_num_interrupt_states = 0; -int __gl_unreserve_all_interrupts = 0; -int __gl_exception_tracebacks = 0; -int __gl_zero_cost_exceptions = 0; -int __gl_detect_blocking = 0; -int __gl_default_stack_size = -1; -int __gl_leap_seconds_support = 0; -int __gl_canonical_streams = 0; - -/* Indication of whether synchronous signal handler has already been - installed by a previous call to adainit. */ -int __gnat_handler_installed = 0; - -#ifndef IN_RTS -int __gnat_inside_elab_final_code = 0; -/* ??? This variable is obsolete since 2001-08-29 but is kept to allow - bootstrap from old GNAT versions (< 3.15). */ -#endif - -/* HAVE_GNAT_INIT_FLOAT must be set on every targets where a __gnat_init_float - is defined. If this is not set then a void implementation will be defined - at the end of this unit. */ -#undef HAVE_GNAT_INIT_FLOAT - -/******************************/ -/* __gnat_get_interrupt_state */ -/******************************/ - -char __gnat_get_interrupt_state (int); - -/* This routine is called from the runtime as needed to determine the state - of an interrupt, as set by an Interrupt_State pragma appearing anywhere - in the current partition. The input argument is the interrupt number, - and the result is one of the following: - - 'n' this interrupt not set by any Interrupt_State pragma - 'u' Interrupt_State pragma set state to User - 'r' Interrupt_State pragma set state to Runtime - 's' Interrupt_State pragma set state to System */ - -char -__gnat_get_interrupt_state (int intrup) -{ - if (intrup >= __gl_num_interrupt_states) - return 'n'; - else - return __gl_interrupt_states [intrup]; -} - -/***********************************/ -/* __gnat_get_specific_dispatching */ -/***********************************/ - -char __gnat_get_specific_dispatching (int); - -/* This routine is called from the runtime as needed to determine the - priority specific dispatching policy, as set by a - Priority_Specific_Dispatching pragma appearing anywhere in the current - partition. The input argument is the priority number, and the result - is the upper case first character of the policy name, e.g. 'F' for - FIFO_Within_Priorities. A space ' ' is returned if no - Priority_Specific_Dispatching pragma is used in the partition. */ - -char -__gnat_get_specific_dispatching (int priority) -{ - if (__gl_num_specific_dispatching == 0) - return ' '; - else if (priority >= __gl_num_specific_dispatching) - return 'F'; - else - return __gl_priority_specific_dispatching [priority]; -} - -#ifndef IN_RTS - -/**********************/ -/* __gnat_set_globals */ -/**********************/ - -/* This routine is kept for bootstrapping purposes, since the binder generated - file now sets the __gl_* variables directly. */ - -void -__gnat_set_globals (void) -{ -} - -#endif - -/***************/ -/* AIX Section */ -/***************/ - -#if defined (_AIX) - -#include <signal.h> -#include <sys/time.h> - -/* Some versions of AIX don't define SA_NODEFER. */ - -#ifndef SA_NODEFER -#define SA_NODEFER 0 -#endif /* SA_NODEFER */ - -/* Versions of AIX before 4.3 don't have nanosleep but provide - nsleep instead. */ - -#ifndef _AIXVERSION_430 - -extern int nanosleep (struct timestruc_t *, struct timestruc_t *); - -int -nanosleep (struct timestruc_t *Rqtp, struct timestruc_t *Rmtp) -{ - return nsleep (Rqtp, Rmtp); -} - -#endif /* _AIXVERSION_430 */ - -/* Version of AIX before 5.3 don't have pthread_condattr_setclock: - * supply it as a weak symbol here so that if linking on a 5.3 or newer - * machine, we get the real one. - */ - -#ifndef _AIXVERSION_530 -#pragma weak pthread_condattr_setclock -int -pthread_condattr_setclock (pthread_condattr_t *attr, clockid_t cl) { - return 0; -} -#endif - -static void -__gnat_error_handler (int sig, - siginfo_t *si ATTRIBUTE_UNUSED, - void *ucontext ATTRIBUTE_UNUSED) -{ - struct Exception_Data *exception; - const char *msg; - - switch (sig) - { - case SIGSEGV: - /* FIXME: we need to detect the case of a *real* SIGSEGV. */ - exception = &storage_error; - msg = "stack overflow or erroneous memory access"; - break; - - case SIGBUS: - exception = &constraint_error; - msg = "SIGBUS"; - break; - - case SIGFPE: - exception = &constraint_error; - msg = "SIGFPE"; - break; - - default: - exception = &program_error; - msg = "unhandled signal"; - } - - Raise_From_Signal_Handler (exception, msg); -} - -void -__gnat_install_handler (void) -{ - struct sigaction act; - - /* Set up signal handler to map synchronous signals to appropriate - exceptions. Make sure that the handler isn't interrupted by another - signal that might cause a scheduling event! */ - - act.sa_flags = SA_NODEFER | SA_RESTART | SA_SIGINFO; - act.sa_sigaction = __gnat_error_handler; - sigemptyset (&act.sa_mask); - - /* Do not install handlers if interrupt state is "System". */ - if (__gnat_get_interrupt_state (SIGABRT) != 's') - sigaction (SIGABRT, &act, NULL); - if (__gnat_get_interrupt_state (SIGFPE) != 's') - sigaction (SIGFPE, &act, NULL); - if (__gnat_get_interrupt_state (SIGILL) != 's') - sigaction (SIGILL, &act, NULL); - if (__gnat_get_interrupt_state (SIGSEGV) != 's') - sigaction (SIGSEGV, &act, NULL); - if (__gnat_get_interrupt_state (SIGBUS) != 's') - sigaction (SIGBUS, &act, NULL); - - __gnat_handler_installed = 1; -} - -/*****************/ -/* Tru64 section */ -/*****************/ - -#elif defined(__alpha__) && defined(__osf__) - -#include <signal.h> -#include <sys/siginfo.h> - -extern char *__gnat_get_code_loc (struct sigcontext *); -extern void __gnat_set_code_loc (struct sigcontext *, char *); -extern size_t __gnat_machine_state_length (void); - -#define HAVE_GNAT_ADJUST_CONTEXT_FOR_RAISE - -void -__gnat_adjust_context_for_raise (int signo, void *ucontext) -{ - struct sigcontext *sigcontext = (struct sigcontext *) ucontext; - - /* The unwinder expects the signal context to contain the address of the - faulting instruction. For SIGFPE, this depends on the trap shadow - situation (see man ieee). We nonetheless always compensate for it, - considering that PC designates the instruction following the one that - trapped. This is not necessarily true but corresponds to what we have - always observed. */ - if (signo == SIGFPE) - sigcontext->sc_pc--; -} - -static void -__gnat_error_handler (int sig, siginfo_t *si, void *ucontext) -{ - struct Exception_Data *exception; - static int recurse = 0; - const char *msg; - - /* Adjusting is required for every fault context, so adjust for this one - now, before we possibly trigger a recursive fault below. */ - __gnat_adjust_context_for_raise (sig, ucontext); - - /* If this was an explicit signal from a "kill", just resignal it. */ - if (SI_FROMUSER (si)) - { - signal (sig, SIG_DFL); - kill (getpid(), sig); - } - - /* Otherwise, treat it as something we handle. */ - switch (sig) - { - case SIGSEGV: - /* If the problem was permissions, this is a constraint error. - Likewise if the failing address isn't maximally aligned or if - we've recursed. - - ??? Using a static variable here isn't task-safe, but it's - much too hard to do anything else and we're just determining - which exception to raise. */ - if (si->si_code == SEGV_ACCERR - || (long) si->si_addr == 0 - || (((long) si->si_addr) & 3) != 0 - || recurse) - { - exception = &constraint_error; - msg = "SIGSEGV"; - } - else - { - /* See if the page before the faulting page is accessible. Do that - by trying to access it. We'd like to simply try to access - 4096 + the faulting address, but it's not guaranteed to be - the actual address, just to be on the same page. */ - recurse++; - ((volatile char *) - ((long) si->si_addr & - getpagesize ()))[getpagesize ()]; - exception = &storage_error; - msg = "stack overflow or erroneous memory access"; - } - break; - - case SIGBUS: - exception = &program_error; - msg = "SIGBUS"; - break; - - case SIGFPE: - exception = &constraint_error; - msg = "SIGFPE"; - break; - - default: - exception = &program_error; - msg = "unhandled signal"; - } - - recurse = 0; - Raise_From_Signal_Handler (exception, CONST_CAST (char *, msg)); -} - -void -__gnat_install_handler (void) -{ - struct sigaction act; - - /* Setup signal handler to map synchronous signals to appropriate - exceptions. Make sure that the handler isn't interrupted by another - signal that might cause a scheduling event! */ - - act.sa_handler = (void (*) (int)) __gnat_error_handler; - act.sa_flags = SA_RESTART | SA_NODEFER | SA_SIGINFO; - sigemptyset (&act.sa_mask); - - /* Do not install handlers if interrupt state is "System". */ - if (__gnat_get_interrupt_state (SIGABRT) != 's') - sigaction (SIGABRT, &act, NULL); - if (__gnat_get_interrupt_state (SIGFPE) != 's') - sigaction (SIGFPE, &act, NULL); - if (__gnat_get_interrupt_state (SIGILL) != 's') - sigaction (SIGILL, &act, NULL); - if (__gnat_get_interrupt_state (SIGSEGV) != 's') - sigaction (SIGSEGV, &act, NULL); - if (__gnat_get_interrupt_state (SIGBUS) != 's') - sigaction (SIGBUS, &act, NULL); - - __gnat_handler_installed = 1; -} - -/* Routines called by s-mastop-tru64.adb. */ - -#define SC_GP 29 - -char * -__gnat_get_code_loc (struct sigcontext *context) -{ - return (char *) context->sc_pc; -} - -void -__gnat_set_code_loc (struct sigcontext *context, char *pc) -{ - context->sc_pc = (long) pc; -} - -size_t -__gnat_machine_state_length (void) -{ - return sizeof (struct sigcontext); -} - -/*****************/ -/* HP-UX section */ -/*****************/ - -#elif defined (__hpux__) - -#include <signal.h> -#include <sys/ucontext.h> - -static void -__gnat_error_handler (int sig, - siginfo_t *si ATTRIBUTE_UNUSED, - void *ucontext ATTRIBUTE_UNUSED) -{ - struct Exception_Data *exception; - const char *msg; - - switch (sig) - { - case SIGSEGV: - /* FIXME: we need to detect the case of a *real* SIGSEGV. */ - exception = &storage_error; - msg = "stack overflow or erroneous memory access"; - break; - - case SIGBUS: - exception = &constraint_error; - msg = "SIGBUS"; - break; - - case SIGFPE: - exception = &constraint_error; - msg = "SIGFPE"; - break; - - default: - exception = &program_error; - msg = "unhandled signal"; - } - - Raise_From_Signal_Handler (exception, msg); -} - -/* This must be in keeping with System.OS_Interface.Alternate_Stack_Size. */ -#if defined (__hppa__) -char __gnat_alternate_stack[16 * 1024]; /* 2 * SIGSTKSZ */ -#else -char __gnat_alternate_stack[128 * 1024]; /* MINSIGSTKSZ */ -#endif - -void -__gnat_install_handler (void) -{ - struct sigaction act; - - /* Set up signal handler to map synchronous signals to appropriate - exceptions. Make sure that the handler isn't interrupted by another - signal that might cause a scheduling event! Also setup an alternate - stack region for the handler execution so that stack overflows can be - handled properly, avoiding a SEGV generation from stack usage by the - handler itself. */ - - stack_t stack; - stack.ss_sp = __gnat_alternate_stack; - stack.ss_size = sizeof (__gnat_alternate_stack); - stack.ss_flags = 0; - sigaltstack (&stack, NULL); - - act.sa_sigaction = __gnat_error_handler; - act.sa_flags = SA_NODEFER | SA_RESTART | SA_SIGINFO; - sigemptyset (&act.sa_mask); - - /* Do not install handlers if interrupt state is "System". */ - if (__gnat_get_interrupt_state (SIGABRT) != 's') - sigaction (SIGABRT, &act, NULL); - if (__gnat_get_interrupt_state (SIGFPE) != 's') - sigaction (SIGFPE, &act, NULL); - if (__gnat_get_interrupt_state (SIGILL) != 's') - sigaction (SIGILL, &act, NULL); - if (__gnat_get_interrupt_state (SIGBUS) != 's') - sigaction (SIGBUS, &act, NULL); - act.sa_flags |= SA_ONSTACK; - if (__gnat_get_interrupt_state (SIGSEGV) != 's') - sigaction (SIGSEGV, &act, NULL); - - __gnat_handler_installed = 1; -} - -/*********************/ -/* GNU/Linux Section */ -/*********************/ - -#elif defined (linux) - -#include <signal.h> - -#define __USE_GNU 1 /* required to get REG_EIP/RIP from glibc's ucontext.h */ -#include <sys/ucontext.h> - -/* GNU/Linux, which uses glibc, does not define NULL in included - header files. */ - -#if !defined (NULL) -#define NULL ((void *) 0) -#endif - -#if defined (MaRTE) - -/* MaRTE OS provides its own version of sigaction, sigfillset, and - sigemptyset (overriding these symbol names). We want to make sure that - the versions provided by the underlying C library are used here (these - versions are renamed by MaRTE to linux_sigaction, fake_linux_sigfillset, - and fake_linux_sigemptyset, respectively). The MaRTE library will not - always be present (it will not be linked if no tasking constructs are - used), so we use the weak symbol mechanism to point always to the symbols - defined within the C library. */ - -#pragma weak linux_sigaction -int linux_sigaction (int signum, const struct sigaction *act, - struct sigaction *oldact) { - return sigaction (signum, act, oldact); -} -#define sigaction(signum, act, oldact) linux_sigaction (signum, act, oldact) - -#pragma weak fake_linux_sigfillset -void fake_linux_sigfillset (sigset_t *set) { - sigfillset (set); -} -#define sigfillset(set) fake_linux_sigfillset (set) - -#pragma weak fake_linux_sigemptyset -void fake_linux_sigemptyset (sigset_t *set) { - sigemptyset (set); -} -#define sigemptyset(set) fake_linux_sigemptyset (set) - -#endif - -#if defined (i386) || defined (__x86_64__) || defined (__ia64__) - -#define HAVE_GNAT_ADJUST_CONTEXT_FOR_RAISE - -void -__gnat_adjust_context_for_raise (int signo ATTRIBUTE_UNUSED, void *ucontext) -{ - mcontext_t *mcontext = &((ucontext_t *) ucontext)->uc_mcontext; - - /* On the i386 and x86-64 architectures, stack checking is performed by - means of probes with moving stack pointer, that is to say the probed - address is always the value of the stack pointer. Upon hitting the - guard page, the stack pointer therefore points to an inaccessible - address and an alternate signal stack is needed to run the handler. - But there is an additional twist: on these architectures, the EH - return code writes the address of the handler at the target CFA's - value on the stack before doing the jump. As a consequence, if - there is an active handler in the frame whose stack has overflowed, - the stack pointer must nevertheless point to an accessible address - by the time the EH return is executed. - - We therefore adjust the saved value of the stack pointer by the size - of one page + a small dope of 4 words, in order to make sure that it - points to an accessible address in case it's used as the target CFA. - The stack checking code guarantees that this address is unused by the - time this happens. */ - -#if defined (i386) - unsigned long *pc = (unsigned long *)mcontext->gregs[REG_EIP]; - /* The pattern is "orl $0x0,(%esp)" for a probe in 32-bit mode. */ - if (signo == SIGSEGV && pc && *pc == 0x00240c83) - mcontext->gregs[REG_ESP] += 4096 + 4 * sizeof (unsigned long); -#elif defined (__x86_64__) - unsigned long long *pc = (unsigned long long *)mcontext->gregs[REG_RIP]; - if (signo == SIGSEGV && pc - /* The pattern is "orq $0x0,(%rsp)" for a probe in 64-bit mode. */ - && ((*pc & 0xffffffffffLL) == 0x00240c8348LL - /* The pattern may also be "orl $0x0,(%esp)" for a probe in - x32 mode. */ - || (*pc & 0xffffffffLL) == 0x00240c83LL)) - mcontext->gregs[REG_RSP] += 4096 + 4 * sizeof (unsigned long); -#elif defined (__ia64__) - /* ??? The IA-64 unwinder doesn't compensate for signals. */ - mcontext->sc_ip++; -#endif -} - -#endif - -static void -__gnat_error_handler (int sig, siginfo_t *si ATTRIBUTE_UNUSED, void *ucontext) -{ - struct Exception_Data *exception; - const char *msg; - - /* Adjusting is required for every fault context, so adjust for this one - now, before we possibly trigger a recursive fault below. */ - __gnat_adjust_context_for_raise (sig, ucontext); - - switch (sig) - { - case SIGSEGV: - /* Here we would like a discrimination test to see whether the page - before the faulting address is accessible. Unfortunately, Linux - seems to have no way of giving us the faulting address. - - In old versions of init.c, we had a test of the page before the - stack pointer: - - ((volatile char *) - ((long) si->esp_at_signal & - getpagesize ()))[getpagesize ()]; - - but that's wrong since it tests the stack pointer location and the - stack probing code may not move it until all probes succeed. - - For now we simply do not attempt any discrimination at all. Note - that this is quite acceptable, since a "real" SIGSEGV can only - occur as the result of an erroneous program. */ - exception = &storage_error; - msg = "stack overflow or erroneous memory access"; - break; - - case SIGBUS: - exception = &storage_error; - msg = "SIGBUS: possible stack overflow"; - break; - - case SIGFPE: - exception = &constraint_error; - msg = "SIGFPE"; - break; - - default: - exception = &program_error; - msg = "unhandled signal"; - } - - Raise_From_Signal_Handler (exception, msg); -} - -#if defined (i386) || defined (__x86_64__) || defined (__powerpc__) -/* This must be in keeping with System.OS_Interface.Alternate_Stack_Size. */ -char __gnat_alternate_stack[16 * 1024]; /* 2 * SIGSTKSZ */ -#endif - -#ifdef __XENO__ -#include <sys/mman.h> -#include <native/task.h> - -RT_TASK main_task; -#endif - -void -__gnat_install_handler (void) -{ - struct sigaction act; - -#ifdef __XENO__ - int prio; - - if (__gl_main_priority == -1) - prio = 49; - else - prio = __gl_main_priority; - - /* Avoid memory swapping for this program */ - - mlockall (MCL_CURRENT|MCL_FUTURE); - - /* Turn the current Linux task into a native Xenomai task */ - - rt_task_shadow(&main_task, "environment_task", prio, T_FPU); -#endif - - /* Set up signal handler to map synchronous signals to appropriate - exceptions. Make sure that the handler isn't interrupted by another - signal that might cause a scheduling event! Also setup an alternate - stack region for the handler execution so that stack overflows can be - handled properly, avoiding a SEGV generation from stack usage by the - handler itself. */ - -#if defined (i386) || defined (__x86_64__) || defined (__powerpc__) - stack_t stack; - stack.ss_sp = __gnat_alternate_stack; - stack.ss_size = sizeof (__gnat_alternate_stack); - stack.ss_flags = 0; - sigaltstack (&stack, NULL); -#endif - - act.sa_sigaction = __gnat_error_handler; - act.sa_flags = SA_NODEFER | SA_RESTART | SA_SIGINFO; - sigemptyset (&act.sa_mask); - - /* Do not install handlers if interrupt state is "System". */ - if (__gnat_get_interrupt_state (SIGABRT) != 's') - sigaction (SIGABRT, &act, NULL); - if (__gnat_get_interrupt_state (SIGFPE) != 's') - sigaction (SIGFPE, &act, NULL); - if (__gnat_get_interrupt_state (SIGILL) != 's') - sigaction (SIGILL, &act, NULL); - if (__gnat_get_interrupt_state (SIGBUS) != 's') - sigaction (SIGBUS, &act, NULL); -#if defined (i386) || defined (__x86_64__) || defined (__powerpc__) - act.sa_flags |= SA_ONSTACK; -#endif - if (__gnat_get_interrupt_state (SIGSEGV) != 's') - sigaction (SIGSEGV, &act, NULL); - - __gnat_handler_installed = 1; -} - -/****************/ -/* IRIX Section */ -/****************/ - -#elif defined (sgi) - -#include <signal.h> -#include <siginfo.h> - -#ifndef NULL -#define NULL 0 -#endif - -#define SIGADAABORT 48 -#define SIGNAL_STACK_SIZE 4096 -#define SIGNAL_STACK_ALIGNMENT 64 - -#define Check_Abort_Status \ - system__soft_links__check_abort_status -extern int (*Check_Abort_Status) (void); - -extern struct Exception_Data _abort_signal; - -/* We are not setting the SA_SIGINFO bit in the sigaction flags when - connecting that handler, with the effects described in the sigaction - man page: - - SA_SIGINFO If set and the signal is caught, sig is passed as the - first argument to the signal-catching function. If the - second argument is not equal to NULL, it points to a - siginfo_t structure containing the reason why the - signal was generated [see siginfo(5)]; the third - argument points to a ucontext_t structure containing - the receiving process's context when the signal was - delivered [see ucontext(5)]. If cleared and the signal - is caught, the first argument is also the signal number - but the second argument is the signal code identifying - the cause of the signal. The third argument points to a - sigcontext_t structure containing the receiving - process's context when the signal was delivered. This - is the default behavior (see signal(5) for more - details). Additionally, when SA_SIGINFO is set for a - signal, multiple occurrences of that signal will be - queued for delivery in FIFO order (see sigqueue(3) for - a more detailed explanation of this concept), if those - occurrences of that signal were generated using - sigqueue(3). */ - -static void -__gnat_error_handler (int sig, siginfo_t *reason, void *uc ATTRIBUTE_UNUSED) -{ - /* This handler is installed with SA_SIGINFO cleared, but there's no - prototype for the resulting alternative three-argument form, so we - have to hack around this by casting reason to the int actually - passed. */ - int code = (int) reason; - struct Exception_Data *exception; - const char *msg; - - switch (sig) - { - case SIGSEGV: - if (code == EFAULT) - { - exception = &program_error; - msg = "SIGSEGV: (Invalid virtual address)"; - } - else if (code == ENXIO) - { - exception = &program_error; - msg = "SIGSEGV: (Read beyond mapped object)"; - } - else if (code == ENOSPC) - { - exception = &program_error; /* ??? storage_error ??? */ - msg = "SIGSEGV: (Autogrow for file failed)"; - } - else if (code == EACCES || code == EEXIST) - { - /* ??? We handle stack overflows here, some of which do trigger - SIGSEGV + EEXIST on Irix 6.5 although EEXIST is not part of - the documented valid codes for SEGV in the signal(5) man - page. */ - - /* ??? Re-add smarts to further verify that we launched - the stack into a guard page, not an attempt to - write to .text or something. */ - exception = &storage_error; - msg = "SIGSEGV: stack overflow or erroneous memory access"; - } - else - { - /* Just in case the OS guys did it to us again. Sometimes - they fail to document all of the valid codes that are - passed to signal handlers, just in case someone depends - on knowing all the codes. */ - exception = &program_error; - msg = "SIGSEGV: (Undocumented reason)"; - } - break; - - case SIGBUS: - /* Map all bus errors to Program_Error. */ - exception = &program_error; - msg = "SIGBUS"; - break; - - case SIGFPE: - /* Map all fpe errors to Constraint_Error. */ - exception = &constraint_error; - msg = "SIGFPE"; - break; - - case SIGADAABORT: - if ((*Check_Abort_Status) ()) - { - exception = &_abort_signal; - msg = ""; - } - else - return; - - break; - - default: - /* Everything else is a Program_Error. */ - exception = &program_error; - msg = "unhandled signal"; - } - - Raise_From_Signal_Handler (exception, msg); -} - -void -__gnat_install_handler (void) -{ - struct sigaction act; - - /* Setup signal handler to map synchronous signals to appropriate - exceptions. Make sure that the handler isn't interrupted by another - signal that might cause a scheduling event! - - The handler is installed with SA_SIGINFO cleared, but there's no - C++ prototype for the three-argument form, so fake it by using - sa_sigaction and casting the arguments instead. */ - - act.sa_sigaction = __gnat_error_handler; - act.sa_flags = SA_NODEFER + SA_RESTART; - sigfillset (&act.sa_mask); - sigemptyset (&act.sa_mask); - - /* Do not install handlers if interrupt state is "System". */ - if (__gnat_get_interrupt_state (SIGABRT) != 's') - sigaction (SIGABRT, &act, NULL); - if (__gnat_get_interrupt_state (SIGFPE) != 's') - sigaction (SIGFPE, &act, NULL); - if (__gnat_get_interrupt_state (SIGILL) != 's') - sigaction (SIGILL, &act, NULL); - if (__gnat_get_interrupt_state (SIGSEGV) != 's') - sigaction (SIGSEGV, &act, NULL); - if (__gnat_get_interrupt_state (SIGBUS) != 's') - sigaction (SIGBUS, &act, NULL); - if (__gnat_get_interrupt_state (SIGADAABORT) != 's') - sigaction (SIGADAABORT, &act, NULL); - - __gnat_handler_installed = 1; -} - -/*******************/ -/* LynxOS Section */ -/*******************/ - -#elif defined (__Lynx__) - -#include <signal.h> -#include <unistd.h> - -static void -__gnat_error_handler (int sig) -{ - struct Exception_Data *exception; - const char *msg; - - switch(sig) - { - case SIGFPE: - exception = &constraint_error; - msg = "SIGFPE"; - break; - case SIGILL: - exception = &constraint_error; - msg = "SIGILL"; - break; - case SIGSEGV: - exception = &storage_error; - msg = "stack overflow or erroneous memory access"; - break; - case SIGBUS: - exception = &constraint_error; - msg = "SIGBUS"; - break; - default: - exception = &program_error; - msg = "unhandled signal"; - } - - Raise_From_Signal_Handler(exception, msg); -} - -void -__gnat_install_handler(void) -{ - struct sigaction act; - - act.sa_handler = __gnat_error_handler; - act.sa_flags = 0x0; - sigemptyset (&act.sa_mask); - - /* Do not install handlers if interrupt state is "System". */ - if (__gnat_get_interrupt_state (SIGFPE) != 's') - sigaction (SIGFPE, &act, NULL); - if (__gnat_get_interrupt_state (SIGILL) != 's') - sigaction (SIGILL, &act, NULL); - if (__gnat_get_interrupt_state (SIGSEGV) != 's') - sigaction (SIGSEGV, &act, NULL); - if (__gnat_get_interrupt_state (SIGBUS) != 's') - sigaction (SIGBUS, &act, NULL); - - __gnat_handler_installed = 1; -} - -/*******************/ -/* Solaris Section */ -/*******************/ - -#elif defined (sun) && defined (__SVR4) && !defined (__vxworks) - -#include <signal.h> -#include <siginfo.h> -#include <sys/ucontext.h> -#include <sys/regset.h> - -/* The code below is common to SPARC and x86. Beware of the delay slot - differences for signal context adjustments. */ - -#if defined (__sparc) -#define RETURN_ADDR_OFFSET 8 -#else -#define RETURN_ADDR_OFFSET 0 -#endif - -static void -__gnat_error_handler (int sig, siginfo_t *si, void *ucontext ATTRIBUTE_UNUSED) -{ - struct Exception_Data *exception; - static int recurse = 0; - const char *msg; - - switch (sig) - { - case SIGSEGV: - /* If the problem was permissions, this is a constraint error. - Likewise if the failing address isn't maximally aligned or if - we've recursed. - - ??? Using a static variable here isn't task-safe, but it's - much too hard to do anything else and we're just determining - which exception to raise. */ - if (si->si_code == SEGV_ACCERR - || (long) si->si_addr == 0 - || (((long) si->si_addr) & 3) != 0 - || recurse) - { - exception = &constraint_error; - msg = "SIGSEGV"; - } - else - { - /* See if the page before the faulting page is accessible. Do that - by trying to access it. We'd like to simply try to access - 4096 + the faulting address, but it's not guaranteed to be - the actual address, just to be on the same page. */ - recurse++; - ((volatile char *) - ((long) si->si_addr & - getpagesize ()))[getpagesize ()]; - exception = &storage_error; - msg = "stack overflow or erroneous memory access"; - } - break; - - case SIGBUS: - exception = &program_error; - msg = "SIGBUS"; - break; - - case SIGFPE: - exception = &constraint_error; - msg = "SIGFPE"; - break; - - default: - exception = &program_error; - msg = "unhandled signal"; - } - - recurse = 0; - Raise_From_Signal_Handler (exception, msg); -} - -void -__gnat_install_handler (void) -{ - struct sigaction act; - - /* Set up signal handler to map synchronous signals to appropriate - exceptions. Make sure that the handler isn't interrupted by another - signal that might cause a scheduling event! */ - - act.sa_sigaction = __gnat_error_handler; - act.sa_flags = SA_NODEFER | SA_RESTART | SA_SIGINFO; - sigemptyset (&act.sa_mask); - - /* Do not install handlers if interrupt state is "System". */ - if (__gnat_get_interrupt_state (SIGABRT) != 's') - sigaction (SIGABRT, &act, NULL); - if (__gnat_get_interrupt_state (SIGFPE) != 's') - sigaction (SIGFPE, &act, NULL); - if (__gnat_get_interrupt_state (SIGSEGV) != 's') - sigaction (SIGSEGV, &act, NULL); - if (__gnat_get_interrupt_state (SIGBUS) != 's') - sigaction (SIGBUS, &act, NULL); - - __gnat_handler_installed = 1; -} - -/***************/ -/* VMS Section */ -/***************/ - -#elif defined (VMS) - -/* Routine called from binder to override default feature values. */ -void __gnat_set_features (void); -int __gnat_features_set = 0; - -#ifdef __IA64 -#define lib_get_curr_invo_context LIB$I64_GET_CURR_INVO_CONTEXT -#define lib_get_prev_invo_context LIB$I64_GET_PREV_INVO_CONTEXT -#define lib_get_invo_handle LIB$I64_GET_INVO_HANDLE -#else -#define lib_get_curr_invo_context LIB$GET_CURR_INVO_CONTEXT -#define lib_get_prev_invo_context LIB$GET_PREV_INVO_CONTEXT -#define lib_get_invo_handle LIB$GET_INVO_HANDLE -#endif - -/* Define macro symbols for the VMS conditions that become Ada exceptions. - Most of these are also defined in the header file ssdef.h which has not - yet been converted to be recognized by GNU C. */ - -/* Defining these as macros, as opposed to external addresses, allows - them to be used in a case statement below. */ -#define SS$_ACCVIO 12 -#define SS$_HPARITH 1284 -#define SS$_STKOVF 1364 -#define SS$_RESIGNAL 2328 - -/* These codes are in standard message libraries. */ -extern int C$_SIGKILL; -extern int SS$_DEBUG; -extern int LIB$_KEYNOTFOU; -extern int LIB$_ACTIMAGE; -#define CMA$_EXIT_THREAD 4227492 -#define MTH$_FLOOVEMAT 1475268 /* Some ACVC_21 CXA tests */ -#define SS$_INTDIV 1156 - -/* These codes are non standard, which is to say the author is - not sure if they are defined in the standard message libraries - so keep them as macros for now. */ -#define RDB$_STREAM_EOF 20480426 -#define FDL$_UNPRIKW 11829410 - -struct cond_except { - unsigned int cond; - const struct Exception_Data *except; -}; - -struct descriptor_s { - unsigned short len, mbz; - __char_ptr32 adr; -}; - -/* Conditions that don't have an Ada exception counterpart must raise - Non_Ada_Error. Since this is defined in s-auxdec, it should only be - referenced by user programs, not the compiler or tools. Hence the - #ifdef IN_RTS. */ - -#ifdef IN_RTS - -#define Status_Error ada__io_exceptions__status_error -extern struct Exception_Data Status_Error; - -#define Mode_Error ada__io_exceptions__mode_error -extern struct Exception_Data Mode_Error; - -#define Name_Error ada__io_exceptions__name_error -extern struct Exception_Data Name_Error; - -#define Use_Error ada__io_exceptions__use_error -extern struct Exception_Data Use_Error; - -#define Device_Error ada__io_exceptions__device_error -extern struct Exception_Data Device_Error; - -#define End_Error ada__io_exceptions__end_error -extern struct Exception_Data End_Error; - -#define Data_Error ada__io_exceptions__data_error -extern struct Exception_Data Data_Error; - -#define Layout_Error ada__io_exceptions__layout_error -extern struct Exception_Data Layout_Error; - -#define Non_Ada_Error system__aux_dec__non_ada_error -extern struct Exception_Data Non_Ada_Error; - -#define Coded_Exception system__vms_exception_table__coded_exception -extern struct Exception_Data *Coded_Exception (Exception_Code); - -#define Base_Code_In system__vms_exception_table__base_code_in -extern Exception_Code Base_Code_In (Exception_Code); - -/* DEC Ada exceptions are not defined in a header file, so they - must be declared. */ - -#define ADA$_ALREADY_OPEN 0x0031a594 -#define ADA$_CONSTRAINT_ERRO 0x00318324 -#define ADA$_DATA_ERROR 0x003192c4 -#define ADA$_DEVICE_ERROR 0x003195e4 -#define ADA$_END_ERROR 0x00319904 -#define ADA$_FAC_MODE_MISMAT 0x0031a8b3 -#define ADA$_IOSYSFAILED 0x0031af04 -#define ADA$_KEYSIZERR 0x0031aa3c -#define ADA$_KEY_MISMATCH 0x0031a8e3 -#define ADA$_LAYOUT_ERROR 0x00319c24 -#define ADA$_LINEXCMRS 0x0031a8f3 -#define ADA$_MAXLINEXC 0x0031a8eb -#define ADA$_MODE_ERROR 0x00319f44 -#define ADA$_MRN_MISMATCH 0x0031a8db -#define ADA$_MRS_MISMATCH 0x0031a8d3 -#define ADA$_NAME_ERROR 0x0031a264 -#define ADA$_NOT_OPEN 0x0031a58c -#define ADA$_ORG_MISMATCH 0x0031a8bb -#define ADA$_PROGRAM_ERROR 0x00318964 -#define ADA$_RAT_MISMATCH 0x0031a8cb -#define ADA$_RFM_MISMATCH 0x0031a8c3 -#define ADA$_STAOVF 0x00318cac -#define ADA$_STATUS_ERROR 0x0031a584 -#define ADA$_STORAGE_ERROR 0x00318c84 -#define ADA$_UNSUPPORTED 0x0031a8ab -#define ADA$_USE_ERROR 0x0031a8a4 - -/* DEC Ada specific conditions. */ -static const struct cond_except dec_ada_cond_except_table [] = { - {ADA$_PROGRAM_ERROR, &program_error}, - {ADA$_USE_ERROR, &Use_Error}, - {ADA$_KEYSIZERR, &program_error}, - {ADA$_STAOVF, &storage_error}, - {ADA$_CONSTRAINT_ERRO, &constraint_error}, - {ADA$_IOSYSFAILED, &Device_Error}, - {ADA$_LAYOUT_ERROR, &Layout_Error}, - {ADA$_STORAGE_ERROR, &storage_error}, - {ADA$_DATA_ERROR, &Data_Error}, - {ADA$_DEVICE_ERROR, &Device_Error}, - {ADA$_END_ERROR, &End_Error}, - {ADA$_MODE_ERROR, &Mode_Error}, - {ADA$_NAME_ERROR, &Name_Error}, - {ADA$_STATUS_ERROR, &Status_Error}, - {ADA$_NOT_OPEN, &Use_Error}, - {ADA$_ALREADY_OPEN, &Use_Error}, - {ADA$_USE_ERROR, &Use_Error}, - {ADA$_UNSUPPORTED, &Use_Error}, - {ADA$_FAC_MODE_MISMAT, &Use_Error}, - {ADA$_ORG_MISMATCH, &Use_Error}, - {ADA$_RFM_MISMATCH, &Use_Error}, - {ADA$_RAT_MISMATCH, &Use_Error}, - {ADA$_MRS_MISMATCH, &Use_Error}, - {ADA$_MRN_MISMATCH, &Use_Error}, - {ADA$_KEY_MISMATCH, &Use_Error}, - {ADA$_MAXLINEXC, &constraint_error}, - {ADA$_LINEXCMRS, &constraint_error}, - -#if 0 - /* Already handled by a pragma Import_Exception - in Aux_IO_Exceptions */ - {ADA$_LOCK_ERROR, &Lock_Error}, - {ADA$_EXISTENCE_ERROR, &Existence_Error}, - {ADA$_KEY_ERROR, &Key_Error}, -#endif - - {0, 0} -}; - -#endif /* IN_RTS */ - -/* Non-DEC Ada specific conditions. We could probably also put - SS$_HPARITH here and possibly SS$_ACCVIO, SS$_STKOVF. */ -static const struct cond_except cond_except_table [] = { - {MTH$_FLOOVEMAT, &constraint_error}, - {SS$_INTDIV, &constraint_error}, - {0, 0} -}; - -/* To deal with VMS conditions and their mapping to Ada exceptions, - the __gnat_error_handler routine below is installed as an exception - vector having precedence over DEC frame handlers. Some conditions - still need to be handled by such handlers, however, in which case - __gnat_error_handler needs to return SS$_RESIGNAL. Consider for - instance the use of a third party library compiled with DECAda and - performing its own exception handling internally. - - To allow some user-level flexibility, which conditions should be - resignaled is controlled by a predicate function, provided with the - condition value and returning a boolean indication stating whether - this condition should be resignaled or not. - - That predicate function is called indirectly, via a function pointer, - by __gnat_error_handler, and changing that pointer is allowed to the - user code by way of the __gnat_set_resignal_predicate interface. - - The user level function may then implement what it likes, including - for instance the maintenance of a dynamic data structure if the set - of to be resignalled conditions has to change over the program's - lifetime. - - ??? This is not a perfect solution to deal with the possible - interactions between the GNAT and the DECAda exception handling - models and better (more general) schemes are studied. This is so - just provided as a convenient workaround in the meantime, and - should be use with caution since the implementation has been kept - very simple. */ - -typedef int -resignal_predicate (int code); - -static const int * const cond_resignal_table [] = { - &C$_SIGKILL, - (int *)CMA$_EXIT_THREAD, - &SS$_DEBUG, - &LIB$_KEYNOTFOU, - &LIB$_ACTIMAGE, - (int *) RDB$_STREAM_EOF, - (int *) FDL$_UNPRIKW, - 0 -}; - -static const int facility_resignal_table [] = { - 0x1380000, /* RDB */ - 0x2220000, /* SQL */ - 0 -}; - -/* Default GNAT predicate for resignaling conditions. */ - -static int -__gnat_default_resignal_p (int code) -{ - int i, iexcept; - - for (i = 0; facility_resignal_table [i]; i++) - if ((code & 0xfff0000) == facility_resignal_table [i]) - return 1; - - for (i = 0, iexcept = 0; - cond_resignal_table [i] - && !(iexcept = LIB$MATCH_COND (&code, &cond_resignal_table [i])); - i++); - - return iexcept; -} - -/* Static pointer to predicate that the __gnat_error_handler exception - vector invokes to determine if it should resignal a condition. */ - -static resignal_predicate *__gnat_resignal_p = __gnat_default_resignal_p; - -/* User interface to change the predicate pointer to PREDICATE. Reset to - the default if PREDICATE is null. */ - -void -__gnat_set_resignal_predicate (resignal_predicate *predicate) -{ - if (predicate == NULL) - __gnat_resignal_p = __gnat_default_resignal_p; - else - __gnat_resignal_p = predicate; -} - -/* Should match System.Parameters.Default_Exception_Msg_Max_Length. */ -#define Default_Exception_Msg_Max_Length 512 - -/* Action routine for SYS$PUTMSG. There may be multiple - conditions, each with text to be appended to MESSAGE - and separated by line termination. */ - -static int -copy_msg (struct descriptor_s *msgdesc, char *message) -{ - int len = strlen (message); - int copy_len; - - /* Check for buffer overflow and skip. */ - if (len > 0 && len <= Default_Exception_Msg_Max_Length - 3) - { - strcat (message, "\r\n"); - len += 2; - } - - /* Check for buffer overflow and truncate if necessary. */ - copy_len = (len + msgdesc->len <= Default_Exception_Msg_Max_Length - 1 ? - msgdesc->len : - Default_Exception_Msg_Max_Length - 1 - len); - strncpy (&message [len], msgdesc->adr, copy_len); - message [len + copy_len] = 0; - - return 0; -} - -long -__gnat_handle_vms_condition (int *sigargs, void *mechargs) -{ - struct Exception_Data *exception = 0; - Exception_Code base_code; - struct descriptor_s gnat_facility = {4, 0, "GNAT"}; - char message [Default_Exception_Msg_Max_Length]; - - const char *msg = ""; - - /* Check for conditions to resignal which aren't effected by pragma - Import_Exception. */ - if (__gnat_resignal_p (sigargs [1])) - return SS$_RESIGNAL; - -#ifdef IN_RTS - /* See if it's an imported exception. Beware that registered exceptions - are bound to their base code, with the severity bits masked off. */ - base_code = Base_Code_In ((Exception_Code) sigargs[1]); - exception = Coded_Exception (base_code); - - if (exception) - { - message[0] = 0; - - /* Subtract PC & PSL fields which messes with PUTMSG. */ - sigargs[0] -= 2; - SYS$PUTMSG (sigargs, copy_msg, &gnat_facility, message); - sigargs[0] += 2; - msg = message; - - exception->Name_Length = 19; - /* ??? The full name really should be get SYS$GETMSG returns. */ - exception->Full_Name = "IMPORTED_EXCEPTION"; - exception->Import_Code = base_code; - -#ifdef __IA64 - /* Do not adjust the program counter as already points to the next - instruction (just after the call to LIB$STOP). */ - Raise_From_Signal_Handler (exception, msg); -#endif - } -#endif - - if (exception == 0) - switch (sigargs[1]) - { - case SS$_ACCVIO: - if (sigargs[3] == 0) - { - exception = &constraint_error; - msg = "access zero"; - } - else - { - exception = &storage_error; - msg = "stack overflow or erroneous memory access"; - } - __gnat_adjust_context_for_raise (SS$_ACCVIO, (void *)mechargs); - break; - - case SS$_STKOVF: - exception = &storage_error; - msg = "stack overflow"; - __gnat_adjust_context_for_raise (SS$_STKOVF, (void *)mechargs); - break; - - case SS$_HPARITH: -#ifndef IN_RTS - return SS$_RESIGNAL; /* toplev.c handles for compiler */ -#else - exception = &constraint_error; - msg = "arithmetic error"; - __gnat_adjust_context_for_raise (SS$_HPARITH, (void *)mechargs); -#endif - break; - - default: -#ifdef IN_RTS - { - int i; - - /* Scan the DEC Ada exception condition table for a match and fetch - the associated GNAT exception pointer. */ - for (i = 0; - dec_ada_cond_except_table [i].cond && - !LIB$MATCH_COND (&sigargs [1], - &dec_ada_cond_except_table [i].cond); - i++); - exception = (struct Exception_Data *) - dec_ada_cond_except_table [i].except; - - if (!exception) - { - /* Scan the VMS standard condition table for a match and fetch - the associated GNAT exception pointer. */ - for (i = 0; - cond_except_table[i].cond && - !LIB$MATCH_COND (&sigargs[1], &cond_except_table[i].cond); - i++); - exception = (struct Exception_Data *) - cond_except_table [i].except; - - if (!exception) - /* User programs expect Non_Ada_Error to be raised, reference - DEC Ada test CXCONDHAN. */ - exception = &Non_Ada_Error; - } - } -#else - exception = &program_error; -#endif - message[0] = 0; - /* Subtract PC & PSL fields which messes with PUTMSG. */ - sigargs[0] -= 2; - SYS$PUTMSG (sigargs, copy_msg, &gnat_facility, message); - sigargs[0] += 2; - msg = message; - break; - } - - Raise_From_Signal_Handler (exception, msg); -} - -void -__gnat_install_handler (void) -{ - long prvhnd ATTRIBUTE_UNUSED; - -#if !defined (IN_RTS) - SYS$SETEXV (1, __gnat_handle_vms_condition, 3, &prvhnd); -#endif - - __gnat_handler_installed = 1; -} - -/* __gnat_adjust_context_for_raise for Alpha - see comments along with the - default version later in this file. */ - -#if defined (IN_RTS) && defined (__alpha__) - -#include <vms/chfctxdef.h> -#include <vms/chfdef.h> - -#define HAVE_GNAT_ADJUST_CONTEXT_FOR_RAISE - -void -__gnat_adjust_context_for_raise (int signo ATTRIBUTE_UNUSED, void *ucontext) -{ - if (signo == SS$_HPARITH) - { - /* Sub one to the address of the instruction signaling the condition, - located in the sigargs array. */ - - CHF$MECH_ARRAY * mechargs = (CHF$MECH_ARRAY *) ucontext; - CHF$SIGNAL_ARRAY * sigargs - = (CHF$SIGNAL_ARRAY *) mechargs->chf$q_mch_sig_addr; - - int vcount = sigargs->chf$is_sig_args; - int * pc_slot = & (&sigargs->chf$l_sig_name)[vcount-2]; - - (*pc_slot)--; - } -} - -#endif - -/* __gnat_adjust_context_for_raise for ia64. */ - -#if defined (IN_RTS) && defined (__IA64) - -#include <vms/chfctxdef.h> -#include <vms/chfdef.h> - -#define HAVE_GNAT_ADJUST_CONTEXT_FOR_RAISE - -typedef unsigned long long u64; - -void -__gnat_adjust_context_for_raise (int signo ATTRIBUTE_UNUSED, void *ucontext) -{ - /* Add one to the address of the instruction signaling the condition, - located in the 64bits sigargs array. */ - - CHF$MECH_ARRAY * mechargs = (CHF$MECH_ARRAY *) ucontext; - - CHF64$SIGNAL_ARRAY *chfsig64 - = (CHF64$SIGNAL_ARRAY *) mechargs->chf$ph_mch_sig64_addr; - - u64 * post_sigarray - = (u64 *)chfsig64 + 1 + chfsig64->chf64$l_sig_args; - - u64 * ih_pc_loc = post_sigarray - 2; - - (*ih_pc_loc) ++; -} - -#endif - -/* Easier interface for LIB$GET_LOGICAL: put the equivalence of NAME into BUF, - always NUL terminated. In case of error or if the result is longer than - LEN (length of BUF) an empty string is written info BUF. */ - -static void -__gnat_vms_get_logical (const char *name, char *buf, int len) -{ - struct descriptor_s name_desc, result_desc; - int status; - unsigned short rlen; - - /* Build the descriptor for NAME. */ - name_desc.len = strlen (name); - name_desc.mbz = 0; - name_desc.adr = (char *)name; - - /* Build the descriptor for the result. */ - result_desc.len = len; - result_desc.mbz = 0; - result_desc.adr = buf; - - status = LIB$GET_LOGICAL (&name_desc, &result_desc, &rlen); - - if ((status & 1) == 1 && rlen < len) - buf[rlen] = 0; - else - buf[0] = 0; -} - -/* Size of a page on ia64 and alpha VMS. */ -#define VMS_PAGESIZE 8192 - -/* User mode. */ -#define PSL__C_USER 3 - -/* No access. */ -#define PRT__C_NA 0 - -/* Descending region. */ -#define VA__M_DESCEND 1 - -/* Get by virtual address. */ -#define VA___REGSUM_BY_VA 1 - -/* Memory region summary. */ -struct regsum -{ - unsigned long long q_region_id; - unsigned int l_flags; - unsigned int l_region_protection; - void *pq_start_va; - unsigned long long q_region_size; - void *pq_first_free_va; -}; - -extern int SYS$GET_REGION_INFO (unsigned int, unsigned long long *, - void *, void *, unsigned int, - void *, unsigned int *); -extern int SYS$EXPREG_64 (unsigned long long *, unsigned long long, - unsigned int, unsigned int, void **, - unsigned long long *); -extern int SYS$SETPRT_64 (void *, unsigned long long, unsigned int, - unsigned int, void **, unsigned long long *, - unsigned int *); -extern int SYS$PUTMSG (void *, int (*)(), void *, unsigned long long); - -/* Add a guard page in the memory region containing ADDR at ADDR +/- SIZE. - (The sign depends on the kind of the memory region). */ - -static int -__gnat_set_stack_guard_page (void *addr, unsigned long size) -{ - int status; - void *ret_va; - unsigned long long ret_len; - unsigned int ret_prot; - void *start_va; - unsigned long long length; - unsigned int retlen; - struct regsum buffer; - - /* Get the region for ADDR. */ - status = SYS$GET_REGION_INFO - (VA___REGSUM_BY_VA, NULL, addr, NULL, sizeof (buffer), &buffer, &retlen); - - if ((status & 1) != 1) - return -1; - - /* Extend the region. */ - status = SYS$EXPREG_64 (&buffer.q_region_id, - size, 0, 0, &start_va, &length); - - if ((status & 1) != 1) - return -1; - - /* Create a guard page. */ - if (!(buffer.l_flags & VA__M_DESCEND)) - start_va = (void *)((unsigned long long)start_va + length - VMS_PAGESIZE); - - status = SYS$SETPRT_64 (start_va, VMS_PAGESIZE, PSL__C_USER, PRT__C_NA, - &ret_va, &ret_len, &ret_prot); - - if ((status & 1) != 1) - return -1; - return 0; -} - -/* Read logicals to limit the stack(s) size. */ - -static void -__gnat_set_stack_limit (void) -{ -#ifdef __ia64__ - void *sp; - unsigned long size; - char value[16]; - char *e; - - /* The main stack. */ - __gnat_vms_get_logical ("GNAT_STACK_SIZE", value, sizeof (value)); - size = strtoul (value, &e, 0); - if (e > value && *e == 0) - { - asm ("mov %0=sp" : "=r" (sp)); - __gnat_set_stack_guard_page (sp, size * 1024); - } - - /* The register stack. */ - __gnat_vms_get_logical ("GNAT_RBS_SIZE", value, sizeof (value)); - size = strtoul (value, &e, 0); - if (e > value && *e == 0) - { - asm ("mov %0=ar.bsp" : "=r" (sp)); - __gnat_set_stack_guard_page (sp, size * 1024); - } -#endif -} - -/* Feature logical name and global variable address pair. - If we ever add another feature logical to this list, the - feature struct will need to be enhanced to take into account - possible values for *gl_addr. */ -struct feature { - const char *name; - int *gl_addr; -}; - -/* Default values for GNAT features set by environment. */ -int __gl_heap_size = 64; - -/* Array feature logical names and global variable addresses. */ -static const struct feature features[] = { - {"GNAT$NO_MALLOC_64", &__gl_heap_size}, - {0, 0} -}; - -void -__gnat_set_features (void) -{ - int i; - char buff[16]; - - /* Loop through features array and test name for enable/disable. */ - for (i = 0; features[i].name; i++) - { - __gnat_vms_get_logical (features[i].name, buff, sizeof (buff)); - - if (strcmp (buff, "ENABLE") == 0 - || strcmp (buff, "TRUE") == 0 - || strcmp (buff, "1") == 0) - *features[i].gl_addr = 32; - else if (strcmp (buff, "DISABLE") == 0 - || strcmp (buff, "FALSE") == 0 - || strcmp (buff, "0") == 0) - *features[i].gl_addr = 64; - } - - /* Features to artificially limit the stack size. */ - __gnat_set_stack_limit (); - - __gnat_features_set = 1; -} - -/* Return true if the VMS version is 7.x. */ - -extern unsigned int LIB$GETSYI (int *, ...); - -#define SYI$_VERSION 0x1000 - -int -__gnat_is_vms_v7 (void) -{ - struct descriptor_s desc; - char version[8]; - int status; - int code = SYI$_VERSION; - - desc.len = sizeof (version); - desc.mbz = 0; - desc.adr = version; - - status = LIB$GETSYI (&code, 0, &desc); - if ((status & 1) == 1 && version[1] == '7' && version[2] == '.') - return 1; - else - return 0; -} - -/*******************/ -/* FreeBSD Section */ -/*******************/ - -#elif defined (__FreeBSD__) - -#include <signal.h> -#include <sys/ucontext.h> -#include <unistd.h> - -static void -__gnat_error_handler (int sig, - siginfo_t *si ATTRIBUTE_UNUSED, - void *ucontext ATTRIBUTE_UNUSED) -{ - struct Exception_Data *exception; - const char *msg; - - switch (sig) - { - case SIGFPE: - exception = &constraint_error; - msg = "SIGFPE"; - break; - - case SIGILL: - exception = &constraint_error; - msg = "SIGILL"; - break; - - case SIGSEGV: - exception = &storage_error; - msg = "stack overflow or erroneous memory access"; - break; - - case SIGBUS: - exception = &storage_error; - msg = "SIGBUS: possible stack overflow"; - break; - - default: - exception = &program_error; - msg = "unhandled signal"; - } - - Raise_From_Signal_Handler (exception, msg); -} - -void -__gnat_install_handler () -{ - struct sigaction act; - - /* Set up signal handler to map synchronous signals to appropriate - exceptions. Make sure that the handler isn't interrupted by another - signal that might cause a scheduling event! */ - - act.sa_sigaction - = (void (*)(int, struct __siginfo *, void*)) __gnat_error_handler; - act.sa_flags = SA_NODEFER | SA_RESTART | SA_SIGINFO; - (void) sigemptyset (&act.sa_mask); - - (void) sigaction (SIGILL, &act, NULL); - (void) sigaction (SIGFPE, &act, NULL); - (void) sigaction (SIGSEGV, &act, NULL); - (void) sigaction (SIGBUS, &act, NULL); - - __gnat_handler_installed = 1; -} - -/*******************/ -/* VxWorks Section */ -/*******************/ - -#elif defined(__vxworks) - -#include <signal.h> -#include <taskLib.h> - -#ifndef __RTP__ -#include <intLib.h> -#include <iv.h> -#endif - -#ifdef VTHREADS -#include "private/vThreadsP.h" -#endif - -void __gnat_error_handler (int, void *, struct sigcontext *); - -#ifndef __RTP__ - -/* Directly vectored Interrupt routines are not supported when using RTPs. */ - -extern int __gnat_inum_to_ivec (int); - -/* This is needed by the GNAT run time to handle Vxworks interrupts. */ -int -__gnat_inum_to_ivec (int num) -{ - return INUM_TO_IVEC (num); -} -#endif - -#if !defined(__alpha_vxworks) && (_WRS_VXWORKS_MAJOR != 6) && !defined(__RTP__) - -/* getpid is used by s-parint.adb, but is not defined by VxWorks, except - on Alpha VxWorks and VxWorks 6.x (including RTPs). */ - -extern long getpid (void); - -long -getpid (void) -{ - return taskIdSelf (); -} -#endif - -/* VxWorks 653 vThreads expects the field excCnt to be zeroed when a signal is. - handled. The VxWorks version of longjmp does this; GCC's builtin_longjmp - doesn't. */ -void -__gnat_clear_exception_count (void) -{ -#ifdef VTHREADS - WIND_TCB *currentTask = (WIND_TCB *) taskIdSelf(); - - currentTask->vThreads.excCnt = 0; -#endif -} - -/* Handle different SIGnal to exception mappings in different VxWorks - versions. */ -static void -__gnat_map_signal (int sig, void *si ATTRIBUTE_UNUSED, - struct sigcontext *sc ATTRIBUTE_UNUSED) -{ - struct Exception_Data *exception; - const char *msg; - - switch (sig) - { - case SIGFPE: - exception = &constraint_error; - msg = "SIGFPE"; - break; -#ifdef VTHREADS -#ifdef __VXWORKSMILS__ - case SIGILL: - exception = &storage_error; - msg = "SIGILL: possible stack overflow"; - break; - case SIGSEGV: - exception = &storage_error; - msg = "SIGSEGV"; - break; - case SIGBUS: - exception = &program_error; - msg = "SIGBUS"; - break; -#else - case SIGILL: - exception = &constraint_error; - msg = "Floating point exception or SIGILL"; - break; - case SIGSEGV: - exception = &storage_error; - msg = "SIGSEGV"; - break; - case SIGBUS: - exception = &storage_error; - msg = "SIGBUS: possible stack overflow"; - break; -#endif -#elif (_WRS_VXWORKS_MAJOR == 6) - case SIGILL: - exception = &constraint_error; - msg = "SIGILL"; - break; -#ifdef __RTP__ - /* In RTP mode a SIGSEGV is most likely due to a stack overflow, - since stack checking uses the probing mechanism. */ - case SIGSEGV: - exception = &storage_error; - msg = "SIGSEGV: possible stack overflow"; - break; - case SIGBUS: - exception = &program_error; - msg = "SIGBUS"; - break; -#else - /* VxWorks 6 kernel mode with probing. SIGBUS for guard page hit */ - case SIGSEGV: - exception = &storage_error; - msg = "SIGSEGV"; - break; - case SIGBUS: - exception = &storage_error; - msg = "SIGBUS: possible stack overflow"; - break; -#endif -#else - /* VxWorks 5: a SIGILL is most likely due to a stack overflow, - since stack checking uses the stack limit mechanism. */ - case SIGILL: - exception = &storage_error; - msg = "SIGILL: possible stack overflow"; - break; - case SIGSEGV: - exception = &storage_error; - msg = "SIGSEGV"; - break; - case SIGBUS: - exception = &program_error; - msg = "SIGBUS"; - break; -#endif - default: - exception = &program_error; - msg = "unhandled signal"; - } - - __gnat_clear_exception_count (); - Raise_From_Signal_Handler (exception, msg); -} - -/* Tasking and Non-tasking signal handler. Map SIGnal to Ada exception - propagation after the required low level adjustments. */ - -void -__gnat_error_handler (int sig, void *si, struct sigcontext *sc) -{ - sigset_t mask; - - /* VxWorks will always mask out the signal during the signal handler and - will reenable it on a longjmp. GNAT does not generate a longjmp to - return from a signal handler so the signal will still be masked unless - we unmask it. */ - sigprocmask (SIG_SETMASK, NULL, &mask); - sigdelset (&mask, sig); - sigprocmask (SIG_SETMASK, &mask, NULL); - -#if defined (__PPC__) && defined(_WRS_KERNEL) - /* On PowerPC, kernel mode, we process signals through a Call Frame Info - trampoline, voiding the need for myriads of fallback_frame_state - variants in the ZCX runtime. We have no simple way to distinguish ZCX - from SJLJ here, so we do this for SJLJ as well even though this is not - necessary. This only incurs a few extra instructions and a tiny - amount of extra stack usage. */ - - #include "sigtramp.h" - - __gnat_sigtramp (sig, (void *)si, (void *)sc, - (sighandler_t *)&__gnat_map_signal); - -#else - __gnat_map_signal (sig, si, sc); -#endif -} - -void -__gnat_install_handler (void) -{ - struct sigaction act; - - /* Setup signal handler to map synchronous signals to appropriate - exceptions. Make sure that the handler isn't interrupted by another - signal that might cause a scheduling event! */ - - act.sa_handler = __gnat_error_handler; - act.sa_flags = SA_SIGINFO | SA_ONSTACK; - sigemptyset (&act.sa_mask); - - /* For VxWorks, install all signal handlers, since pragma Interrupt_State - applies to vectored hardware interrupts, not signals. */ - sigaction (SIGFPE, &act, NULL); - sigaction (SIGILL, &act, NULL); - sigaction (SIGSEGV, &act, NULL); - sigaction (SIGBUS, &act, NULL); - - __gnat_handler_installed = 1; -} - -#define HAVE_GNAT_INIT_FLOAT - -void -__gnat_init_float (void) -{ - /* Disable overflow/underflow exceptions on the PPC processor, needed - to get correct Ada semantics. Note that for AE653 vThreads, the HW - overflow settings are an OS configuration issue. The instructions - below have no effect. */ -#if defined (_ARCH_PPC) && !defined (_SOFT_FLOAT) && (!defined (VTHREADS) || defined (__VXWORKSMILS__)) -#if defined (__SPE__) - { - const unsigned long spefscr_mask = 0xfffffff3; - unsigned long spefscr; - asm ("mfspr %0, 512" : "=r" (spefscr)); - spefscr = spefscr & spefscr_mask; - asm ("mtspr 512, %0\n\tisync" : : "r" (spefscr)); - } -#else - asm ("mtfsb0 25"); - asm ("mtfsb0 26"); -#endif -#endif - -#if (defined (__i386__) || defined (i386)) && !defined (VTHREADS) - /* This is used to properly initialize the FPU on an x86 for each - process thread. */ - asm ("finit"); -#endif - - /* Similarly for SPARC64. Achieved by masking bits in the Trap Enable Mask - field of the Floating-point Status Register (see the SPARC Architecture - Manual Version 9, p 48). */ -#if defined (sparc64) - -#define FSR_TEM_NVM (1 << 27) /* Invalid operand */ -#define FSR_TEM_OFM (1 << 26) /* Overflow */ -#define FSR_TEM_UFM (1 << 25) /* Underflow */ -#define FSR_TEM_DZM (1 << 24) /* Division by Zero */ -#define FSR_TEM_NXM (1 << 23) /* Inexact result */ - { - unsigned int fsr; - - __asm__("st %%fsr, %0" : "=m" (fsr)); - fsr &= ~(FSR_TEM_OFM | FSR_TEM_UFM); - __asm__("ld %0, %%fsr" : : "m" (fsr)); - } -#endif -} - -/* This subprogram is called by System.Task_Primitives.Operations.Enter_Task - (if not null) when a new task is created. It is initialized by - System.Stack_Checking.Operations.Initialize_Stack_Limit. - The use of a hook avoids to drag stack checking subprograms if stack - checking is not used. */ -void (*__gnat_set_stack_limit_hook)(void) = (void (*)(void))0; - -/******************/ -/* NetBSD Section */ -/******************/ - -#elif defined(__NetBSD__) - -#include <signal.h> -#include <unistd.h> - -static void -__gnat_error_handler (int sig) -{ - struct Exception_Data *exception; - const char *msg; - - switch(sig) - { - case SIGFPE: - exception = &constraint_error; - msg = "SIGFPE"; - break; - case SIGILL: - exception = &constraint_error; - msg = "SIGILL"; - break; - case SIGSEGV: - exception = &storage_error; - msg = "stack overflow or erroneous memory access"; - break; - case SIGBUS: - exception = &constraint_error; - msg = "SIGBUS"; - break; - default: - exception = &program_error; - msg = "unhandled signal"; - } - - Raise_From_Signal_Handler(exception, msg); -} - -void -__gnat_install_handler(void) -{ - struct sigaction act; - - act.sa_handler = __gnat_error_handler; - act.sa_flags = SA_NODEFER | SA_RESTART; - sigemptyset (&act.sa_mask); - - /* Do not install handlers if interrupt state is "System". */ - if (__gnat_get_interrupt_state (SIGFPE) != 's') - sigaction (SIGFPE, &act, NULL); - if (__gnat_get_interrupt_state (SIGILL) != 's') - sigaction (SIGILL, &act, NULL); - if (__gnat_get_interrupt_state (SIGSEGV) != 's') - sigaction (SIGSEGV, &act, NULL); - if (__gnat_get_interrupt_state (SIGBUS) != 's') - sigaction (SIGBUS, &act, NULL); - - __gnat_handler_installed = 1; -} - -/*******************/ -/* OpenBSD Section */ -/*******************/ - -#elif defined(__OpenBSD__) - -#include <signal.h> -#include <unistd.h> - -static void -__gnat_error_handler (int sig) -{ - struct Exception_Data *exception; - const char *msg; - - switch(sig) - { - case SIGFPE: - exception = &constraint_error; - msg = "SIGFPE"; - break; - case SIGILL: - exception = &constraint_error; - msg = "SIGILL"; - break; - case SIGSEGV: - exception = &storage_error; - msg = "stack overflow or erroneous memory access"; - break; - case SIGBUS: - exception = &constraint_error; - msg = "SIGBUS"; - break; - default: - exception = &program_error; - msg = "unhandled signal"; - } - - Raise_From_Signal_Handler(exception, msg); -} - -void -__gnat_install_handler(void) -{ - struct sigaction act; - - act.sa_handler = __gnat_error_handler; - act.sa_flags = SA_NODEFER | SA_RESTART; - sigemptyset (&act.sa_mask); - - /* Do not install handlers if interrupt state is "System" */ - if (__gnat_get_interrupt_state (SIGFPE) != 's') - sigaction (SIGFPE, &act, NULL); - if (__gnat_get_interrupt_state (SIGILL) != 's') - sigaction (SIGILL, &act, NULL); - if (__gnat_get_interrupt_state (SIGSEGV) != 's') - sigaction (SIGSEGV, &act, NULL); - if (__gnat_get_interrupt_state (SIGBUS) != 's') - sigaction (SIGBUS, &act, NULL); - - __gnat_handler_installed = 1; -} - -/******************/ -/* Darwin Section */ -/******************/ - -#elif defined(__APPLE__) - -#include <signal.h> -#include <sys/syscall.h> -#include <mach/mach_vm.h> -#include <mach/mach_init.h> -#include <mach/vm_statistics.h> - -/* This must be in keeping with System.OS_Interface.Alternate_Stack_Size. */ -char __gnat_alternate_stack[32 * 1024]; /* 1 * MINSIGSTKSZ */ - -/* Defined in xnu unix_signal.c. - Tell the kernel to re-use alt stack when delivering a signal. */ -#define UC_RESET_ALT_STACK 0x80000000 - -/* Return true if ADDR is within a stack guard area. */ -static int -__gnat_is_stack_guard (mach_vm_address_t addr) -{ - kern_return_t kret; - vm_region_submap_info_data_64_t info; - mach_vm_address_t start; - mach_vm_size_t size; - natural_t depth; - mach_msg_type_number_t count; - - count = VM_REGION_SUBMAP_INFO_COUNT_64; - start = addr; - size = -1; - depth = 9999; - kret = mach_vm_region_recurse (mach_task_self (), &start, &size, &depth, - (vm_region_recurse_info_t) &info, &count); - if (kret == KERN_SUCCESS - && addr >= start && addr < (start + size) - && info.protection == VM_PROT_NONE - && info.user_tag == VM_MEMORY_STACK) - return 1; - return 0; -} - -#define HAVE_GNAT_ADJUST_CONTEXT_FOR_RAISE - -void -__gnat_adjust_context_for_raise (int signo ATTRIBUTE_UNUSED, - void *ucontext ATTRIBUTE_UNUSED) -{ -#if defined (__x86_64__) - /* Work around radar #10302855/pr50678, where the unwinders (libunwind or - libgcc_s depending on the system revision) and the DWARF unwind data for - the sigtramp have different ideas about register numbering (causing rbx - and rdx to be transposed).. */ - ucontext_t *uc = (ucontext_t *)ucontext ; - unsigned long t = uc->uc_mcontext->__ss.__rbx; - - uc->uc_mcontext->__ss.__rbx = uc->uc_mcontext->__ss.__rdx; - uc->uc_mcontext->__ss.__rdx = t; -#endif -} - -static void -__gnat_error_handler (int sig, siginfo_t *si, void *ucontext) -{ - struct Exception_Data *exception; - const char *msg; - - __gnat_adjust_context_for_raise (sig, ucontext); - - switch (sig) - { - case SIGSEGV: - case SIGBUS: - if (__gnat_is_stack_guard ((unsigned long)si->si_addr)) - { - exception = &storage_error; - msg = "stack overflow"; - } - else - { - exception = &constraint_error; - msg = "erroneous memory access"; - } - /* Reset the use of alt stack, so that the alt stack will be used - for the next signal delivery. - The stack can't be used in case of stack checking. */ - syscall (SYS_sigreturn, NULL, UC_RESET_ALT_STACK); - break; - - case SIGFPE: - exception = &constraint_error; - msg = "SIGFPE"; - break; - - default: - exception = &program_error; - msg = "unhandled signal"; - } - - Raise_From_Signal_Handler (exception, msg); -} - -void -__gnat_install_handler (void) -{ - struct sigaction act; - - /* Set up signal handler to map synchronous signals to appropriate - exceptions. Make sure that the handler isn't interrupted by another - signal that might cause a scheduling event! Also setup an alternate - stack region for the handler execution so that stack overflows can be - handled properly, avoiding a SEGV generation from stack usage by the - handler itself (and it is required by Darwin). */ - - stack_t stack; - stack.ss_sp = __gnat_alternate_stack; - stack.ss_size = sizeof (__gnat_alternate_stack); - stack.ss_flags = 0; - sigaltstack (&stack, NULL); - - act.sa_flags = SA_NODEFER | SA_RESTART | SA_SIGINFO; - act.sa_sigaction = __gnat_error_handler; - sigemptyset (&act.sa_mask); - - /* Do not install handlers if interrupt state is "System". */ - if (__gnat_get_interrupt_state (SIGABRT) != 's') - sigaction (SIGABRT, &act, NULL); - if (__gnat_get_interrupt_state (SIGFPE) != 's') - sigaction (SIGFPE, &act, NULL); - if (__gnat_get_interrupt_state (SIGILL) != 's') - sigaction (SIGILL, &act, NULL); - - act.sa_flags |= SA_ONSTACK; - if (__gnat_get_interrupt_state (SIGSEGV) != 's') - sigaction (SIGSEGV, &act, NULL); - if (__gnat_get_interrupt_state (SIGBUS) != 's') - sigaction (SIGBUS, &act, NULL); - - __gnat_handler_installed = 1; -} - -#else - -/* For all other versions of GNAT, the handler does nothing. */ - -/*******************/ -/* Default Section */ -/*******************/ - -void -__gnat_install_handler (void) -{ - __gnat_handler_installed = 1; -} - -#endif - -/*********************/ -/* __gnat_init_float */ -/*********************/ - -/* This routine is called as each process thread is created, for possible - initialization of the FP processor. This version is used under INTERIX - and WIN32. */ - -#if defined (_WIN32) || defined (__INTERIX) \ - || defined (__Lynx__) || defined(__NetBSD__) || defined(__FreeBSD__) \ - || defined (__OpenBSD__) - -#define HAVE_GNAT_INIT_FLOAT - -void -__gnat_init_float (void) -{ -#if defined (__i386__) || defined (i386) || defined (__x86_64) - - /* This is used to properly initialize the FPU on an x86 for each - process thread. */ - - asm ("finit"); - -#endif /* Defined __i386__ */ -} -#endif - -#ifndef HAVE_GNAT_INIT_FLOAT - -/* All targets without a specific __gnat_init_float will use an empty one. */ -void -__gnat_init_float (void) -{ -} -#endif - -/***********************************/ -/* __gnat_adjust_context_for_raise */ -/***********************************/ - -#ifndef HAVE_GNAT_ADJUST_CONTEXT_FOR_RAISE - -/* All targets without a specific version will use an empty one. */ - -/* Given UCONTEXT a pointer to a context structure received by a signal - handler for SIGNO, perform the necessary adjustments to let the handler - raise an exception. Calls to this routine are not conditioned by the - propagation scheme in use. */ - -void -__gnat_adjust_context_for_raise (int signo ATTRIBUTE_UNUSED, - void *ucontext ATTRIBUTE_UNUSED) -{ - /* We used to compensate here for the raised from call vs raised from signal - exception discrepancy with the GCC ZCX scheme, but this now can be dealt - with generically in the unwinder (see GCC PR other/26208). This however - requires the use of the _Unwind_GetIPInfo routine in raise-gcc.c, which - is predicated on the definition of HAVE_GETIPINFO at compile time. Only - the VMS ports still do the compensation described in the few lines below. - - *** Call vs signal exception discrepancy with GCC ZCX scheme *** - - The GCC unwinder expects to be dealing with call return addresses, since - this is the "nominal" case of what we retrieve while unwinding a regular - call chain. - - To evaluate if a handler applies at some point identified by a return - address, the propagation engine needs to determine what region the - corresponding call instruction pertains to. Because the return address - may not be attached to the same region as the call, the unwinder always - subtracts "some" amount from a return address to search the region - tables, amount chosen to ensure that the resulting address is inside the - call instruction. - - When we raise an exception from a signal handler, e.g. to transform a - SIGSEGV into Storage_Error, things need to appear as if the signal - handler had been "called" by the instruction which triggered the signal, - so that exception handlers that apply there are considered. What the - unwinder will retrieve as the return address from the signal handler is - what it will find as the faulting instruction address in the signal - context pushed by the kernel. Leaving this address untouched looses, if - the triggering instruction happens to be the very first of a region, as - the later adjustments performed by the unwinder would yield an address - outside that region. We need to compensate for the unwinder adjustments - at some point, and this is what this routine is expected to do. - - signo is passed because on some targets for some signals the PC in - context points to the instruction after the faulting one, in which case - the unwinder adjustment is still desired. */ -} - -#endif - -#ifdef __cplusplus -} -#endif |