/**************************************************************************** * * * GNAT COMPILER COMPONENTS * * * * I N I T * * * * C Implementation File * * * * Copyright (C) 1992-2005, 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 2, 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. See the GNU General Public License * * for more details. You should have received a copy of the GNU General * * Public License distributed with GNAT; see file COPYING. If not, write * * to the Free Software Foundation, 59 Temple Place - Suite 330, Boston, * * MA 02111-1307, USA. * * * * As a special exception, if you link this file with other files to * * produce an executable, this file does not by itself cause the resulting * * executable to be covered by the GNU General Public License. This except- * * ion does not however invalidate any other reasons why the executable * * file might be covered by the GNU Public License. * * * * 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 involved 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 handle resulting signals that come from these probes failing (i.e. touching protected pages) */ /* This file should be kept synchronized with 2sinit.ads, 2sinit.adb, and 5zinit.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 /* We don't have libiberty, so us 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. */ extern struct Exception_Data constraint_error; extern struct Exception_Data numeric_error; extern struct Exception_Data program_error; extern struct Exception_Data storage_error; extern struct Exception_Data tasking_error; extern struct Exception_Data _abort_signal; #define Lock_Task system__soft_links__lock_task extern void (*Lock_Task) (void); #define Unlock_Task system__soft_links__unlock_task extern void (*Unlock_Task) (void); #define Get_Machine_State_Addr \ system__soft_links__get_machine_state_addr extern struct Machine_State *(*Get_Machine_State_Addr) (void); #define Check_Abort_Status \ system__soft_links__check_abort_status extern int (*Check_Abort_Status) (void); #define Raise_From_Signal_Handler \ ada__exceptions__raise_from_signal_handler extern void Raise_From_Signal_Handler (struct Exception_Data *, const char *); #define Propagate_Signal_Exception \ __gnat_propagate_sig_exc extern void Propagate_Signal_Exception (struct Machine_State *, struct Exception_Data *, const char *); /* Copies of global values computed by the binder */ int __gl_main_priority = -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_restrictions = 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; /* Indication of whether synchronous signal handler has already been installed by a previous call to adainit */ int __gnat_handler_installed = 0; /* HAVE_GNAT_INIT_FLOAT must be set on every targets where a __gnat_init_float is defined. If this is not set them 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_set_globals */ /**********************/ /* This routine is called from the binder generated main program. It copies the values for global quantities computed by the binder into the following global locations. The reason that we go through this copy, rather than just define the global locations in the binder generated file, is that they are referenced from the runtime, which may be in a shared library, and the binder file is not in the shared library. Global references across library boundaries like this are not handled correctly in all systems. */ /* For detailed description of the parameters to this routine, see the section titled Run-Time Globals in package Bindgen (bindgen.adb) */ void __gnat_set_globals (int main_priority, int time_slice_val, char wc_encoding, char locking_policy, char queuing_policy, char task_dispatching_policy, char *restrictions, char *interrupt_states, int num_interrupt_states, int unreserve_all_interrupts, int exception_tracebacks, int zero_cost_exceptions, int detect_blocking) { static int already_called = 0; /* If this procedure has been already called once, check that the arguments in this call are consistent with the ones in the previous calls. Otherwise, raise a Program_Error exception. We do not check for consistency of the wide character encoding method. This default affects only Wide_Text_IO where no explicit coding method is given, and there is no particular reason to let this default be affected by the source representation of a library in any case. We do not check either for the consistency of exception tracebacks, because exception tracebacks are not normally set in Stand-Alone libraries. If a library or the main program set the exception tracebacks, then they are never reset afterwards (see below). The value of main_priority is meaningful only when we are invoked from the main program elaboration routine of an Ada application. Checking the consistency of this parameter should therefore not be done. Since it is assured that the main program elaboration will always invoke this procedure before any library elaboration routine, only the value of main_priority during the first call should be taken into account and all the subsequent ones should be ignored. Note that the case where the main program is not written in Ada is also properly handled, since the default value will then be used for this parameter. For identical reasons, the consistency of time_slice_val should not be checked. */ if (already_called) { if (__gl_locking_policy != locking_policy || __gl_queuing_policy != queuing_policy || __gl_task_dispatching_policy != task_dispatching_policy || __gl_unreserve_all_interrupts != unreserve_all_interrupts || __gl_zero_cost_exceptions != zero_cost_exceptions) __gnat_raise_program_error (__FILE__, __LINE__); /* If either a library or the main program set the exception traceback flag, it is never reset later */ if (exception_tracebacks != 0) __gl_exception_tracebacks = exception_tracebacks; return; } already_called = 1; __gl_main_priority = main_priority; __gl_time_slice_val = time_slice_val; __gl_wc_encoding = wc_encoding; __gl_locking_policy = locking_policy; __gl_queuing_policy = queuing_policy; __gl_restrictions = restrictions; __gl_interrupt_states = interrupt_states; __gl_num_interrupt_states = num_interrupt_states; __gl_task_dispatching_policy = task_dispatching_policy; __gl_unreserve_all_interrupts = unreserve_all_interrupts; __gl_exception_tracebacks = exception_tracebacks; __gl_detect_blocking = detect_blocking; /* ??? __gl_zero_cost_exceptions is new in 3.15 and is referenced from a-except.adb, which is also part of the compiler sources. Since the compiler is built with an older release of GNAT, the call generated by the old binder to this function does not provide any value for the corresponding argument, so the global has to be initialized in some reasonable other way. This could be removed as soon as the next major release is out. */ #ifdef IN_RTS __gl_zero_cost_exceptions = zero_cost_exceptions; #else __gl_zero_cost_exceptions = 0; /* We never build the compiler to run in ZCX mode currently anyway. */ #endif } /*********************/ /* __gnat_initialize */ /*********************/ /* __gnat_initialize is called at the start of execution of an Ada program (the call is generated by the binder). The standard routine does nothing at all; the intention is that this be replaced by system specific code where initialization is required. */ /* Notes on the Zero Cost Exceptions scheme and its impact on the signal handlers implemented below : What we call Zero Cost Exceptions is implemented using the GCC eh circuitry, even if the underlying implementation is setjmp/longjmp based. In any case ... 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 in this chain, the propagation engine needs to determine what region the corresponding call instruction pertains to. The return address may not be attached to the same region as the call, so the unwinder unconditionally substracts "some" amount to the return addresses it gets to search the region tables. The exact amount is computed to ensure that the resulting address is inside the call instruction, and is thus target dependant (think about delay slots for instance). 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 corresponding signal context pushed by the kernel. Leaving this address untouched may loose, because if the triggering instruction happens to be the very first of a region, the later adjustments performed by the unwinder would yield an address outside that region. We need to compensate for those adjustments at some point, which we currently do in the GCC unwinding fallback macro. The thread at http://gcc.gnu.org/ml/gcc-patches/2004-05/msg00343.html describes a couple of issues with our current approach. Basically: on some targets the adjustment to apply depends on the triggering signal, which is not easily accessible from the macro, and we actually do not tackle this as of today. Besides, other languages, e.g. Java, deal with this by performing the adjustment in the signal handler before the raise, so our adjustments may break those front-ends. To have it all right, we should either find a way to deal with the signal variants from the macro and convert Java on all targets (ugh), or remove our macro adjustments and update our signal handlers a-la-java way. The latter option appears the simplest, although some targets have their share of subtleties to account for. See for instance the syscall(SYS_sigaction) story in libjava/include/i386-signal.h. */ /***********************************/ /* __gnat_initialize (AIX Version) */ /***********************************/ #if defined (_AIX) #include #include /* 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 */ static void __gnat_error_handler (int); static void __gnat_error_handler (int sig) { 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_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 (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; } void __gnat_initialize (void *eh ATTRIBUTE_UNUSED) { } /***************************************/ /* __gnat_initialize (RTEMS version) */ /***************************************/ #elif defined(__rtems__) extern void __gnat_install_handler (void); /* For RTEMS, each bsp will provide a custom __gnat_install_handler (). */ void __gnat_initialize (void *eh ATTRIBUTE_UNUSED) { __gnat_install_handler (); } /****************************************/ /* __gnat_initialize (Dec Unix Version) */ /****************************************/ #elif defined(__alpha__) && defined(__osf__) && ! defined(__alpha_vxworks) /* Note: it seems that __osf__ is defined for the Alpha VXWorks case. Not clear that this is reasonable, but in any case we have to be sure to exclude this case in the above test. */ #include #include static void __gnat_error_handler (int, siginfo_t *, struct sigcontext *); extern char *__gnat_get_code_loc (struct sigcontext *); extern void __gnat_enter_handler (struct sigcontext *, char *); extern size_t __gnat_machine_state_length (void); extern long exc_lookup_gp (char *); extern void exc_resume (struct sigcontext *); static void __gnat_error_handler (int sig, siginfo_t *sip, struct sigcontext *context) { struct Exception_Data *exception; static int recurse = 0; struct sigcontext *mstate; const char *msg; /* If this was an explicit signal from a "kill", just resignal it. */ if (SI_FROMUSER (sip)) { 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 (sip->si_code == SEGV_ACCERR || (((long) sip->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) sip->si_addr & - getpagesize ()))[getpagesize ()]; msg = "stack overflow (or erroneous memory access)"; exception = &storage_error; } 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; mstate = (struct sigcontext *) (*Get_Machine_State_Addr) (); if (mstate != 0) *mstate = *context; Raise_From_Signal_Handler (exception, (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; } void __gnat_initialize (void *eh ATTRIBUTE_UNUSED) { } /* 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_enter_handler (struct sigcontext *context, char *pc) { context->sc_pc = (long) pc; context->sc_regs[SC_GP] = exc_lookup_gp (pc); exc_resume (context); } size_t __gnat_machine_state_length (void) { return sizeof (struct sigcontext); } /************************************/ /* __gnat_initialize (HPUX Version) */ /************************************/ #elif defined (__hpux__) #include #include static void __gnat_error_handler (int sig, siginfo_t *siginfo, void *ucontext); /* __gnat_adjust_context_for_raise - see comments along with the default version later in this file. */ #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; if (UseWideRegs (mcontext)) mcontext->ss_wide.ss_32.ss_pcoq_head_lo ++; else mcontext->ss_narrow.ss_pcoq_head ++; } static void __gnat_error_handler (int sig, siginfo_t *siginfo, void *ucontext) { struct Exception_Data *exception; 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"; } __gnat_adjust_context_for_raise (sig, ucontext); 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. */ static char handler_stack[SIGSTKSZ*2]; /* SIGSTKSZ appeared to be "short" for the needs in some contexts (e.g. experiments with GCC ZCX exceptions). */ stack_t stack; stack.ss_sp = handler_stack; stack.ss_size = sizeof (handler_stack); stack.ss_flags = 0; sigaltstack (&stack, NULL); act.sa_sigaction = __gnat_error_handler; act.sa_flags = SA_NODEFER | SA_RESTART | SA_ONSTACK | 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; } void __gnat_initialize (void *eh ATTRIBUTE_UNUSED) { } /*****************************************/ /* __gnat_initialize (GNU/Linux Version) */ /*****************************************/ #elif defined (linux) && defined (i386) && !defined (__RT__) #include #include /* GNU/Linux, which uses glibc, does not define NULL in included header files */ #if !defined (NULL) #define NULL ((void *) 0) #endif struct Machine_State { unsigned long eip; unsigned long ebx; unsigned long esp; unsigned long ebp; unsigned long esi; unsigned long edi; }; static void __gnat_error_handler (int); static void __gnat_error_handler (int sig) { struct Exception_Data *exception; const char *msg; static int recurse = 0; struct sigcontext *info = (struct sigcontext *) (((char *) &sig) + sizeof (int)); /* The Linux kernel does not document how to get the machine state in a signal handler, but in fact the necessary data is in a sigcontext_struct value that is on the stack immediately above the signal number parameter, and the above messing accesses this value on the stack. */ struct Machine_State *mstate; 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 (recurse) { exception = &constraint_error; msg = "SIGSEGV"; } else { /* 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 versions of a-init.c before 1.95, we had a test of the page before the stack pointer using: recurse++; ((volatile char *) ((long) info->esp_at_signal & - getpagesize ()))[getpagesize ()]; but that's wrong, since it tests the stack pointer location, and the current stack probe code does not move the stack pointer 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 */ msg = "stack overflow (or erroneous memory access)"; exception = &storage_error; } break; case SIGBUS: exception = &constraint_error; msg = "SIGBUS"; break; case SIGFPE: exception = &constraint_error; msg = "SIGFPE"; break; default: exception = &program_error; msg = "unhandled signal"; } mstate = (*Get_Machine_State_Addr) (); if (mstate) { mstate->eip = info->eip; mstate->ebx = info->ebx; mstate->esp = info->esp_at_signal; mstate->ebp = info->ebp; mstate->esi = info->esi; mstate->edi = info->edi; } 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_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 (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; } void __gnat_initialize (void *eh ATTRIBUTE_UNUSED) { } /******************************************/ /* __gnat_initialize (NT-mingw32 Version) */ /******************************************/ #elif defined (__MINGW32__) #include void __gnat_install_handler (void) { } void __gnat_initialize (void *eh ATTRIBUTE_UNUSED) { /* Initialize floating-point coprocessor. This call is needed because the MS libraries default to 64-bit precision instead of 80-bit precision, and we require the full precision for proper operation, given that we have set Max_Digits etc with this in mind */ __gnat_init_float (); /* Initialize a lock for a process handle list - see a-adaint.c for the implementation of __gnat_portable_no_block_spawn, __gnat_portable_wait */ __gnat_plist_init(); /* Note that we do not activate this for the compiler itself to avoid a bootstrap path problem. Older version of gnatbind will generate a call to __gnat_initialize() without argument. Therefore we cannot use eh in this case. It will be possible to remove the following #ifdef at some point. */ #ifdef IN_RTS /* Install the Structured Exception handler. */ if (eh) __gnat_install_SEH_handler (eh); #endif } /***************************************/ /* __gnat_initialize (Interix Version) */ /***************************************/ #elif defined (__INTERIX) #include static void __gnat_error_handler (int); static void __gnat_error_handler (int sig) { struct Exception_Data *exception; char *msg; switch (sig) { case 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_handler = __gnat_error_handler; act.sa_flags = 0; sigemptyset (&act.sa_mask); /* Handlers for signals besides SIGSEGV cause c974013 to hang */ /* sigaction (SIGILL, &act, NULL); */ /* sigaction (SIGABRT, &act, NULL); */ /* sigaction (SIGFPE, &act, NULL); */ /* sigaction (SIGBUS, &act, NULL); */ /* Do not install handlers if interrupt state is "System" */ if (__gnat_get_interrupt_state (SIGSEGV) != 's') sigaction (SIGSEGV, &act, NULL); __gnat_handler_installed = 1; } void __gnat_initialize (void *eh ATTRIBUTE_UNUSED) { __gnat_init_float (); } /**************************************/ /* __gnat_initialize (LynxOS Version) */ /**************************************/ #elif defined (__Lynx__) void __gnat_initialize (void *eh ATTRIBUTE_UNUSED) { __gnat_init_float (); } /*********************************/ /* __gnat_install_handler (Lynx) */ /*********************************/ void __gnat_install_handler (void) { __gnat_handler_installed = 1; } /****************************/ /* __gnat_initialize (OS/2) */ /****************************/ #elif defined (__EMX__) /* OS/2 dependent initialization */ void __gnat_initialize (void *eh ATTRIBUTE_UNUSED) { } /*********************************/ /* __gnat_install_handler (OS/2) */ /*********************************/ void __gnat_install_handler (void) { __gnat_handler_installed = 1; } /***********************************/ /* __gnat_initialize (SGI Version) */ /***********************************/ #elif defined (sgi) #include #include #ifndef NULL #define NULL 0 #endif #define SIGADAABORT 48 #define SIGNAL_STACK_SIZE 4096 #define SIGNAL_STACK_ALIGNMENT 64 struct Machine_State { sigcontext_t context; }; static void __gnat_error_handler (int, int, sigcontext_t *); /* 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 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. */ static void __gnat_error_handler (int sig, int code, sigcontext_t *sc) { struct Machine_State *mstate; 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"; } mstate = (*Get_Machine_State_Addr) (); if (mstate != 0) memcpy ((void *) mstate, (const void *) sc, sizeof (sigcontext_t)); 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! */ act.sa_handler = __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; } void __gnat_initialize (void *eh ATTRIBUTE_UNUSED) { } /*************************************************/ /* __gnat_initialize (Solaris and SunOS Version) */ /*************************************************/ #elif defined (sun) && defined (__SVR4) && !defined (__vxworks) #include #include static void __gnat_error_handler (int, siginfo_t *); static void __gnat_error_handler (int sig, siginfo_t *sip) { struct Exception_Data *exception; static int recurse = 0; const char *msg; /* If this was an explicit signal from a "kill", just resignal it. */ if (SI_FROMUSER (sip)) { 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 (sip->si_code == SEGV_ACCERR || (((long) sip->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) sip->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_handler = __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; } void __gnat_initialize (void *eh ATTRIBUTE_UNUSED) { } /***********************************/ /* __gnat_initialize (VMS Version) */ /***********************************/ #elif defined (VMS) #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 #if defined (IN_RTS) && !defined (__IA64) /* The prehandler actually gets control first on a condition. It swaps the stack pointer and calls the handler (__gnat_error_handler). */ extern long __gnat_error_prehandler (void); extern char *__gnat_error_prehandler_stack; /* Alternate signal stack */ #endif /* 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 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); #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. Some, which couldn't be located, are assigned names based on the DEC test suite tests which raise them. */ #define SS$_ACCVIO 12 #define SS$_DEBUG 1132 #define SS$_INTDIV 1156 #define SS$_HPARITH 1284 #define SS$_STKOVF 1364 #define SS$_RESIGNAL 2328 #define MTH$_FLOOVEMAT 1475268 /* Some ACVC_21 CXA tests */ #define SS$_CE24VRU 3253636 /* Write to unopened file */ #define SS$_C980VTE 3246436 /* AST requests time slice */ #define CMA$_EXIT_THREAD 4227492 #define CMA$_EXCCOPLOS 4228108 #define CMA$_ALERTED 4227460 struct descriptor_s {unsigned short len, mbz; char *adr; }; long __gnat_error_handler (int *, void *); /* 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$_RESIGNAL. Consider for instance the use of a third party library compiled with DECAda and performing its own exception handling internally. To allow some user-level flexibility, which conditions should be resignaled is controlled by a predicate function, provided with the condition value and returning a boolean indication stating whether this condition should be resignaled or not. That predicate function is called indirectly, via a function pointer, by __gnat_error_handler, and changing that pointer is allowed to the the user code by way of the __gnat_set_resignal_predicate interface. The user level function may then implement what it likes, including for instance the maintenance of a dynamic data structure if the set of to be resignalled conditions has to change over the program's lifetime. ??? This is not a perfect solution to deal with the possible interactions between the GNAT and the DECAda exception handling models and better (more general) schemes are studied. This is so just provided as a convenient workaround in the meantime, and should be use with caution since the implementation has been kept very simple. */ typedef int resignal_predicate (int code); /* Default GNAT predicate for resignaling conditions. */ static int __gnat_default_resignal_p (int code) { return code == CMA$_EXIT_THREAD || code == SS$_DEBUG /* Gdb attach, resignal to merge activate gdbstub. */ || code == 1409786 /* Nickerson bug #33 ??? */ || code == 1381050 /* Nickerson bug #33 ??? */ || code == 20480426 /* RDB-E-STREAM_EOF */ || code == 11829410 /* Resignalled as Use_Error for CE10VRC */ ; } /* Static pointer to predicate that the __gnat_error_handler exception vector invokes to determine if it should resignal a condition. */ static resignal_predicate * __gnat_resignal_p = __gnat_default_resignal_p; /* User interface to change the predicate pointer to PREDICATE. Reset to the default if PREDICATE is null. */ void __gnat_set_resignal_predicate (resignal_predicate * predicate) { if (predicate == 0) __gnat_resignal_p = __gnat_default_resignal_p; else __gnat_resignal_p = predicate; } long __gnat_error_handler (int *sigargs, void *mechargs) { struct Exception_Data *exception = 0; Exception_Code base_code; char *msg = ""; char message[256]; long prvhnd; struct descriptor_s msgdesc; int msg_flag = 0x000f; /* 1 bit for each of the four message parts */ unsigned short outlen; char curr_icb[544]; long curr_invo_handle; long *mstate; /* Check for conditions to resignal which aren't effected by pragma Import_Exception. */ if (__gnat_resignal_p (sigargs [1])) return SS$_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) { msgdesc.len = 256; msgdesc.mbz = 0; msgdesc.adr = message; SYS$GETMSG (sigargs[1], &outlen, &msgdesc, msg_flag, 0); message[outlen] = 0; msg = message; exception->Name_Length = 19; /* The full name really should be get sys$getmsg returns. ??? */ exception->Full_Name = "IMPORTED_EXCEPTION"; exception->Import_Code = base_code; } #endif if (exception == 0) switch (sigargs[1]) { case SS$_ACCVIO: if (sigargs[3] == 0) { exception = &constraint_error; msg = "access zero"; } else { exception = &storage_error; msg = "stack overflow (or erroneous memory access)"; } break; case SS$_STKOVF: exception = &storage_error; msg = "stack overflow"; break; case SS$_INTDIV: exception = &constraint_error; msg = "division by zero"; break; case SS$_HPARITH: #ifndef IN_RTS return SS$_RESIGNAL; /* toplev.c handles for compiler */ #else { exception = &constraint_error; msg = "arithmetic error"; } #endif break; case MTH$_FLOOVEMAT: exception = &constraint_error; msg = "floating overflow in math library"; break; case SS$_CE24VRU: exception = &constraint_error; msg = ""; break; case SS$_C980VTE: exception = &program_error; msg = ""; break; default: #ifndef IN_RTS exception = &program_error; #else /* User programs expect Non_Ada_Error to be raised, reference DEC Ada test CXCONDHAN. */ exception = &Non_Ada_Error; #endif msgdesc.len = 256; msgdesc.mbz = 0; msgdesc.adr = message; SYS$GETMSG (sigargs[1], &outlen, &msgdesc, msg_flag, 0); message[outlen] = 0; msg = message; break; } mstate = (long *) (*Get_Machine_State_Addr) (); if (mstate != 0) { lib_get_curr_invo_context (&curr_icb); lib_get_prev_invo_context (&curr_icb); lib_get_prev_invo_context (&curr_icb); curr_invo_handle = lib_get_invo_handle (&curr_icb); *mstate = curr_invo_handle; } Raise_From_Signal_Handler (exception, msg); } void __gnat_install_handler (void) { long prvhnd; #if defined (IN_RTS) && !defined (__IA64) char *c; c = (char *) xmalloc (2049); __gnat_error_prehandler_stack = &c[2048]; /* __gnat_error_prehandler is an assembly function. */ SYS$SETEXV (1, __gnat_error_prehandler, 3, &prvhnd); #else SYS$SETEXV (1, __gnat_error_handler, 3, &prvhnd); #endif __gnat_handler_installed = 1; } void __gnat_initialize(void *eh ATTRIBUTE_UNUSED) { } /*************************************************/ /* __gnat_initialize (FreeBSD version) */ /*************************************************/ #elif defined (__FreeBSD__) #include #include static void __gnat_error_handler (int, int, struct sigcontext *); static void __gnat_error_handler (int sig, int code __attribute__ ((unused)), struct sigcontext *sc __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 = &constraint_error; msg = "SIGBUS"; 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_handler = __gnat_error_handler; act.sa_flags = SA_NODEFER | SA_RESTART; (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); } void __gnat_initialize (void *eh ATTRIBUTE_UNUSED) { __gnat_install_handler (); /* XXX - Initialize floating-point coprocessor. This call is needed because FreeBSD defaults to 64-bit precision instead of 80-bit precision? We require the full precision for proper operation, given that we have set Max_Digits etc with this in mind */ __gnat_init_float (); } /***************************************/ /* __gnat_initialize (VXWorks Version) */ /***************************************/ #elif defined(__vxworks) #include #include #include #include #ifdef VTHREADS #include "private/vThreadsP.h" #endif extern int __gnat_inum_to_ivec (int); static void __gnat_error_handler (int, int, struct sigcontext *); void __gnat_map_signal (int); #ifndef __alpha_vxworks /* getpid is used by s-parint.adb, but is not defined by VxWorks, except on Alpha VxWorks */ extern long getpid (void); long getpid (void) { return taskIdSelf (); } #endif /* This is needed by the GNAT run time to handle Vxworks interrupts */ int __gnat_inum_to_ivec (int num) { return INUM_TO_IVEC (num); } /* VxWorks expects the field excCnt to be zeroed when a signal is handled. The VxWorks version of longjmp does this; gcc's builtin_longjmp does not */ void __gnat_clear_exception_count (void) { #ifdef VTHREADS WIND_TCB *currentTask = (WIND_TCB *) taskIdSelf(); currentTask->vThreads.excCnt = 0; #endif } /* Exported to 5zintman.adb in order to handle different signal to exception mappings in different VxWorks versions */ void __gnat_map_signal (int sig) { struct Exception_Data *exception; char *msg; switch (sig) { case SIGFPE: exception = &constraint_error; msg = "SIGFPE"; break; #ifdef VTHREADS case SIGILL: exception = &constraint_error; msg = "Floating point exception or SIGILL"; break; case SIGSEGV: exception = &storage_error; msg = "SIGSEGV: possible stack overflow"; break; case SIGBUS: exception = &storage_error; msg = "SIGBUS: possible stack overflow"; break; #else case SIGILL: exception = &constraint_error; msg = "SIGILL"; break; case SIGSEGV: exception = &program_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); } static void __gnat_error_handler (int sig, int code, struct sigcontext *sc) { sigset_t mask; int result; /* 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); __gnat_map_signal (sig); } 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, this is 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) asm ("mtfsb0 25"); asm ("mtfsb0 26"); #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 } void __gnat_initialize (void *eh ATTRIBUTE_UNUSED) { __gnat_init_float (); /* On targets where we might be using the ZCX scheme, we need to register the frame tables. For applications loaded as a set of "modules", the crtstuff objects linked in (crtbegin/end) are tailored to provide this service a-la C++ constructor fashion, typically triggered by the VxWorks loader. This is achieved by way of a special variable declaration in the crt object, the name of which has been deduced by analyzing the output of the "munching" step documented for C++. The de-registration is handled symetrically, a-la C++ destructor fashion and typically triggered by the dynamic unloader. Note that since the tables shall be registered against a common datastructure, libgcc should be one of the modules (vs beeing partially linked against all the others at build time) and shall be loaded first. For applications linked with the kernel, the scheme above would lead to duplicated symbols because the VxWorks kernel build "munches" by default. To prevent those conflicts, we link against crtbegin/endS objects that don't include the special variable and directly call the appropriate function here. We'll never unload that, so there is no de-registration to worry about. For whole applications loaded as a single module, we may use one scheme or the other, except for the mixed Ada/C++ case in which the first scheme would fail for the same reason as in the linked-with-kernel situation. We can differentiate by looking at the __module_has_ctors value provided by each class of crt objects. As of today, selecting the crt set with the ctors/dtors capabilities (first scheme above) is triggered by adding "-dynamic" to the gcc *link* command line options. Selecting the other set of crt objects is achieved by "-static" instead. This is a first approach, tightly synchronized with a number of GCC configuration and crtstuff changes. We need to ensure that those changes are there to activate this circuitry. */ #if (__GNUC__ >= 3) && (defined (_ARCH_PPC) || defined (__ppc)) { /* The scheme described above is only useful for the actual ZCX case, and we don't want any reference to the crt provided symbols otherwise. We may not link with any of the crt objects in the non-ZCX case, e.g. from documented procedures instructing the use of -nostdlib, and references to the ctors symbols here would just remain unsatisfied. We have no way to avoid those references in the right conditions in this C module, because we have nothing like a IN_ZCX_RTS macro. This aspect is then deferred to an Ada routine, which can do that based on a test against a constant System flag value. */ extern void __gnat_vxw_setup_for_eh (void); __gnat_vxw_setup_for_eh (); } #endif } /********************************/ /* __gnat_initialize for NetBSD */ /********************************/ #elif defined(__NetBSD__) #include #include 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; } void __gnat_initialize (void *eh ATTRIBUTE_UNUSED) { __gnat_install_handler (); __gnat_init_float (); } #else /* For all other versions of GNAT, the initialize routine and handler installation do nothing */ /***************************************/ /* __gnat_initialize (Default Version) */ /***************************************/ void __gnat_initialize (void *eh ATTRIBUTE_UNUSED) { } /********************************************/ /* __gnat_install_handler (Default Version) */ /********************************************/ 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, WIN32 and could be used under OS/2 */ #if defined (_WIN32) || defined (__INTERIX) || defined (__EMX__) \ || defined (__Lynx__) || defined(__NetBSD__) || defined(__FreeBSD__) #define HAVE_GNAT_INIT_FLOAT void __gnat_init_float (void) { #if defined (__i386__) || defined (i386) /* 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 */ /* UCONTEXT is a pointer to a context structure received by a signal handler about to propagate an exception. Adjust it to compensate the fact that the generic unwinder thinks the corresponding PC is a call return address. */ void __gnat_adjust_context_for_raise (int signo ATTRIBUTE_UNUSED, void *ucontext ATTRIBUTE_UNUSED) { /* The point is that the interrupted context PC typically is the address that we should search an EH region for, which is different from the call return address case. The target independant part of the GCC unwinder don't differentiate the two situations, so we compensate here for the adjustments it will blindly make. 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. */ /* On a number of targets, we have arranged for the adjustment to be performed by the MD_FALLBACK_FRAME_STATE circuitry, so we don't provide a specific instance of this routine. The MD_FALLBACK doesn't have access to the signal number, though, so the compensation is systematic there and might be wrong in some cases. */ /* Having the compensation wrong leads to potential failures. A very typical case is what happens when there is no compensation and a signal triggers for the first instruction in a region : the unwinder adjustment has it search in the wrong EH region. */ } #endif