{
}
-/* Routines called by 5amastop.adb. */
+/* Routines called by s-mastop-tru64.adb. */
#define SC_GP 29
}
void
-__gnat_enter_handler ( struct sigcontext *context, char *pc)
+__gnat_enter_handler (struct sigcontext *context, char *pc)
{
context->sc_pc = (long) pc;
context->sc_regs[SC_GP] = exc_lookup_gp (pc);
#elif defined (__hpux__)
#include <signal.h>
+#include <sys/ucontext.h>
-static void __gnat_error_handler (int);
+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)
+__gnat_error_handler (int sig, siginfo_t *siginfo, void *ucontext)
{
struct Exception_Data *exception;
char *msg;
msg = "unhandled signal";
}
+ __gnat_adjust_context_for_raise (sig, ucontext);
+
Raise_From_Signal_Handler (exception, msg);
}
sigaltstack (&stack, NULL);
- act.sa_handler = __gnat_error_handler;
- act.sa_flags = SA_NODEFER | SA_RESTART | SA_ONSTACK;
+ 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" */
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
}
/***************************************/
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$_RESIGNAL. Consider for
+ instance the use of a third party library compiled with DECAda and
+ performing it's own exception handling internally.
+
+ To allow some user-level flexibility, which conditions should be
+ resignaled is controlled by a predicate function, provided with the
+ condition value and returning a boolean indication stating whether
+ this condition should be resignaled or not.
+
+ That predicate function is called indirectly, via a function pointer,
+ by __gnat_error_handler, and changing that pointer is allowed to the
+ the user code by way of the __gnat_set_resignal_predicate interface.
+
+ The user level function may then implement what it likes, including
+ for instance the maintenance of a dynamic data structure if the set
+ of to be resignalled conditions has to change over the program's
+ lifetime.
+
+ ??? This is not a perfect solution to deal with the possible
+ interactions between the GNAT and the DECAda exception handling
+ models and better (more general) schemes are studied. This is so
+ just provided as a conveniency workaround in the meantime, and
+ should be use with caution since the implementation has been kept
+ very simple. */
+
+typedef int
+resignal_predicate (int code);
+
+/* Default GNAT predicate for resignaling conditions. */
+
+static int
+__gnat_default_resignal_p (int code)
+{
+ return
+ code == CMA$_EXIT_THREAD
+ || code == SS$_DEBUG /* Gdb attach, resignal to merge activate gdbstub. */
+ || code == 1409786 /* Nickerson bug #33 ??? */
+ || code == 1381050 /* Nickerson bug #33 ??? */
+ || code == 20480426 /* RDB-E-STREAM_EOF */
+ || code == 11829410 /* Resignalled as Use_Error for CE10VRC */
+ ;
+}
+
+/* Static pointer to predicate that the __gnat_error_handler exception
+ vector invokes to determine if it should resignal a condition. */
+
+static resignal_predicate * __gnat_resignal_p = __gnat_default_resignal_p;
+
+/* User interface to change the predicate pointer to PREDICATE. Reset to
+ the default if PREDICATE is null. */
+
+void
+__gnat_set_resignal_predicate (resignal_predicate * predicate)
+{
+ if (predicate == 0)
+ __gnat_resignal_p = __gnat_default_resignal_p;
+ else
+ __gnat_resignal_p = predicate;
+}
+
long
__gnat_error_handler (int *sigargs, void *mechargs)
{
long curr_invo_handle;
long *mstate;
- /* Resignaled condtions aren't effected by by pragma Import_Exception */
-
- switch (sigargs[1])
- {
-
- case CMA$_EXIT_THREAD:
- return SS$_RESIGNAL;
-
- case SS$_DEBUG: /* Gdb attach, resignal to merge activate gdbstub. */
- return SS$_RESIGNAL;
-
- case 1409786: /* Nickerson bug #33 ??? */
- return SS$_RESIGNAL;
-
- case 1381050: /* Nickerson bug #33 ??? */
- return SS$_RESIGNAL;
-
- case 20480426: /* RDB-E-STREAM_EOF */
- return SS$_RESIGNAL;
-
- case 11829410: /* Resignalled as Use_Error for CE10VRC */
- return SS$_RESIGNAL;
-
- }
+ /* Check for conditions to resignal which aren't effected by pragma
+ Import_Exception. */
+ if (__gnat_resignal_p (sigargs [1]))
+ return SS$_RESIGNAL;
#ifdef IN_RTS
/* See if it's an imported exception. Beware that registered exceptions
{
}
#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
-- --
-- B o d y --
-- --
--- Copyright (C) 1992-2003, Free Software Foundation, Inc. --
+-- Copyright (C) 1992-2005, Free Software Foundation, Inc. --
-- --
-- GNARL 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- --
-- Local Subprograms --
-----------------------
- procedure Notify_Exception (signo : Signal);
+ procedure Notify_Exception
+ (signo : Signal;
+ siginfo : System.Address;
+ ucontext : System.Address);
-- This function identifies the Ada exception to be raised using
-- the information when the system received a synchronous signal.
-- Since this function is machine and OS dependent, different code
Signal_Mask : aliased sigset_t;
-- The set of signals handled by Notify_Exception
- procedure Notify_Exception (signo : Signal) is
+ procedure Notify_Exception
+ (signo : Signal;
+ siginfo : System.Address;
+ ucontext : System.Address)
+ is
+ pragma Unreferenced (siginfo);
+
+ -- The GCC unwinder requires adjustments to the signal's machine
+ -- context to be able to properly unwind through the signal handler.
+ -- This is achieved by the target specific subprogram below, provided
+ -- by init.c to be usable by the non-tasking handler also.
+
+ procedure Adjust_Context_For_Raise
+ (signo : Signal;
+ ucontext : System.Address);
+ pragma Import
+ (C, Adjust_Context_For_Raise, "__gnat_adjust_context_for_raise");
+
Result : Interfaces.C.int;
begin
Result := pthread_sigmask (SIG_UNBLOCK, Signal_Mask'Access, null);
pragma Assert (Result = 0);
+ -- Perform the necessary context adjustments required by the GCC/ZCX
+ -- unwinder, harmless in the SJLJ case.
+
+ Adjust_Context_For_Raise (signo, ucontext);
+
-- Check that treatment of exception propagation here
-- is consistent with treatment of the abort signal in
-- System.Task_Primitives.Operations.
-- Setting SA_SIGINFO asks the kernel to pass more than just the signal
-- number argument to the handler when it is called. The set of extra
- -- parameters typically includes a pointer to a structure describing
- -- the interrupted context. Although the Notify_Exception handler does
- -- not use this information, it is actually required for the GCC/ZCX
- -- exception propagation scheme because on some targets (at least
- -- alpha-tru64), the structure contents are not even filled when this
- -- flag is not set.
+ -- parameters includes a pointer to the interrupted context, which the
+ -- ZCX propagation scheme needs.
+
+ -- Most man pages for sigaction mention that sa_sigaction should be set
+ -- instead of sa_handler when SA_SIGINFO is on. In practice, the two
+ -- fields are actually union'ed and located at the same offset.
-- On some targets, we set sa_flags to SA_NODEFER so that during the
-- handler execution we do not change the Signal_Mask to be masked for
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