static void
get_action_description_for (_Unwind_Ptr ip,
_Unwind_Exception *uw_exception,
_Unwind_Action uw_phase,
region_descriptor *region,
action_descriptor *action)
{
_GNAT_Exception *gnat_exception = (_GNAT_Exception *) uw_exception;
/* Search the call site table first, which may get us a landing pad as well
as the head of an action record list. */
get_call_site_action_for (ip, region, action);
db_action_for (action, ip);
/* If there is not even a call_site entry, we are done. */
if (action->kind == nothing)
return;
/* Otherwise, check what we have at the place of the call site. */
/* No landing pad => no cleanups or handlers. */
if (action->landing_pad == 0)
{
action->kind = nothing;
return;
}
/* Landing pad + null table entry => only cleanups. */
else if (action->table_entry == 0)
{
action->kind = cleanup;
action->ttype_filter = cleanup_filter;
/* The filter initialization is not strictly necessary, as cleanup-only
landing pads don't look at the filter value. It is there to ensure
we don't pass random values and so trigger potential confusion when
installing the context later on. */
return;
}
/* Landing pad + Table entry => handlers + possible cleanups. */
else
{
const unsigned char * p = action->table_entry;
_sleb128_t ar_filter, ar_disp;
action->kind = nothing;
while (1)
{
p = read_sleb128 (p, &ar_filter);
read_sleb128 (p, &ar_disp);
/* Don't assign p here, as it will be incremented by ar_disp
below. */
/* Null filters are for cleanups. */
if (ar_filter == cleanup_filter)
{
action->kind = cleanup;
action->ttype_filter = cleanup_filter;
/* The filter initialization is required here, to ensure
the target landing pad branches to the cleanup code if
we happen not to find a matching handler. */
}
/* Positive filters are for regular handlers. */
else if (ar_filter > 0)
{
/* Do not catch an exception if the _UA_FORCE_UNWIND flag is
passed (to follow the ABI). */
if (!(uw_phase & _UA_FORCE_UNWIND))
{
enum action_kind act;
/* See if the filter we have is for an exception which
matches the one we are propagating. */
_Unwind_Ptr choice = get_ttype_entry_for (region, ar_filter);
act = is_handled_by (choice, gnat_exception);
if (act != nothing)
{
action->kind = act;
action->ttype_filter = ar_filter;
return;
}
}
}
/* Negative filter values are for C++ exception specifications.
Should not be there for Ada :/ */
else
db (DB_ERR, "========> Err, filter < 0 for Ada/dwarf\n");
if (ar_disp == 0)
return;
p += ar_disp;
}
}
}
_Unwind_Reason_Code
__gnat_eh_personality (int uw_version,
_Unwind_Action uw_phases,
_Unwind_Exception_Class uw_exception_class,
_Unwind_Exception *uw_exception,
_Unwind_Context *uw_context)
{
_GNAT_Exception * gnat_exception = (_GNAT_Exception *) uw_exception;
region_descriptor region;
action_descriptor action;
if (uw_version != 1)
return _URC_FATAL_PHASE1_ERROR;
db_indent (DB_INDENT_RESET);
db_phases (uw_phases);
db_indent (DB_INDENT_INCREASE);
/* Get the region description for the context we were provided with. This
will tell us if there is some lsda, call_site, action and/or ttype data
for the associated ip. */
get_region_description_for (uw_context, ®ion);
db_region_for (®ion, uw_context);
/* No LSDA => no handlers or cleanups => we shall unwind further up. */
if (! region.lsda)
return _URC_CONTINUE_UNWIND;
/* Search the call-site and action-record tables for the action associated
with this IP. */
get_action_description_for (uw_context, uw_exception, ®ion, &action);
db_action_for (&action, uw_context);
/* Whatever the phase, if there is nothing relevant in this frame,
unwinding should just go on. */
if (action.kind == nothing)
return _URC_CONTINUE_UNWIND;
/* If we found something in search phase, we should return a code indicating
what to do next depending on what we found. If we only have cleanups
around, we shall try to unwind further up to find a handler, otherwise,
tell we have a handler, which will trigger the second phase. */
if (uw_phases & _UA_SEARCH_PHASE)
{
if (action.kind == cleanup)
{
gnat_exception->n_cleanups_to_trigger ++;
return _URC_CONTINUE_UNWIND;
}
else
{
/* Trigger the appropriate notification routines before the second
phase starts, which ensures the stack is still intact. */
__gnat_notify_handled_exception ();
return _URC_HANDLER_FOUND;
}
}
/* We found something in cleanup/handler phase, which might be the handler
or a cleanup for a handled occurrence, or a cleanup for an unhandled
occurrence (we are in a FORCED_UNWIND phase in this case). Install the
context to get there. */
/* If we are going to install a cleanup context, decrement the cleanup
count. This is required in a FORCED_UNWINDing phase (for an unhandled
exception), as this is used from the forced unwinding handler in
Ada.Exceptions.Exception_Propagation to decide wether unwinding should
proceed further or Unhandled_Exception_Terminate should be called. */
if (action.kind == cleanup)
gnat_exception->n_cleanups_to_trigger --;
setup_to_install
(uw_context, uw_exception, action.landing_pad, action.ttype_filter);
return _URC_INSTALL_CONTEXT;
}
_Unwind_Reason_Code
PERSONALITY_FUNCTION (version_arg_t version_arg,
phases_arg_t phases_arg,
_Unwind_Exception_Class uw_exception_class
ATTRIBUTE_UNUSED,
_Unwind_Exception *uw_exception,
_Unwind_Context *uw_context)
{
/* Fetch the version and phases args with their nominal ABI types for later
use. This is a noop everywhere except on ia64-vms when called from the
Condition Handling Facility. */
int uw_version = (int) version_arg;
_Unwind_Action uw_phases = (_Unwind_Action) phases_arg;
region_descriptor region;
action_descriptor action;
_Unwind_Ptr ip;
/* Check that we're called from the ABI context we expect, with a major
possible variation on VMS for IA64. */
if (uw_version != 1)
{
#if defined (VMS) && defined (__IA64)
/* Assume we're called with sigargs/mechargs arguments if really
unexpected bits are set in our first two formals. Redirect to the
GNAT condition handling code in this case. */
extern long __gnat_handle_vms_condition (void *, void *);
unsigned int version_unexpected_bits_mask = 0xffffff00U;
unsigned int phases_unexpected_bits_mask = 0xffffff00U;
if ((unsigned int)uw_version & version_unexpected_bits_mask
&& (unsigned int)uw_phases & phases_unexpected_bits_mask)
return __gnat_handle_vms_condition (version_arg, phases_arg);
#endif
return _URC_FATAL_PHASE1_ERROR;
}
db_indent (DB_INDENT_RESET);
db_phases (uw_phases);
db_indent (DB_INDENT_INCREASE);
/* Get the region description for the context we were provided with. This
will tell us if there is some lsda, call_site, action and/or ttype data
for the associated ip. */
get_region_description_for (uw_context, ®ion);
ip = get_ip_from_context (uw_context);
db_region_for (®ion, ip);
/* No LSDA => no handlers or cleanups => we shall unwind further up. */
if (! region.lsda)
return _URC_CONTINUE_UNWIND;
/* Search the call-site and action-record tables for the action associated
with this IP. */
get_action_description_for (ip, uw_exception, uw_phases, ®ion, &action);
db_action_for (&action, ip);
/* Whatever the phase, if there is nothing relevant in this frame,
unwinding should just go on. */
if (action.kind == nothing)
return _URC_CONTINUE_UNWIND;
/* If we found something in search phase, we should return a code indicating
what to do next depending on what we found. If we only have cleanups
around, we shall try to unwind further up to find a handler, otherwise,
tell we have a handler, which will trigger the second phase. */
if (uw_phases & _UA_SEARCH_PHASE)
{
if (action.kind == cleanup)
{
return _URC_CONTINUE_UNWIND;
}
else
{
struct Exception_Occurrence *excep;
/* Trigger the appropriate notification routines before the second
phase starts, which ensures the stack is still intact.
First, setup the Ada occurrence. */
excep = __gnat_setup_current_excep (uw_exception);
if (action.kind == unhandler)
__gnat_notify_unhandled_exception (excep);
else
__gnat_notify_handled_exception (excep);
return _URC_HANDLER_FOUND;
}
}
/* We found something in cleanup/handler phase, which might be the handler
or a cleanup for a handled occurrence, or a cleanup for an unhandled
occurrence (we are in a FORCED_UNWIND phase in this case). Install the
context to get there. */
setup_to_install
(uw_context, uw_exception, action.landing_pad, action.ttype_filter);
/* Write current exception, so that it can be retrieved from Ada. */
__gnat_setup_current_excep (uw_exception);
return _URC_INSTALL_CONTEXT;
}
static void
get_action_description_for (_Unwind_Context *uw_context,
_Unwind_Exception *uw_exception,
region_descriptor *region,
action_descriptor *action)
{
_GNAT_Exception * gnat_exception = (_GNAT_Exception *) uw_exception;
/* Search the call site table first, which may get us a landing pad as well
as the head of an action record list. */
get_call_site_action_for (uw_context, region, action);
db_action_for (action, uw_context);
/* If there is not even a call_site entry, we are done. */
if (action->kind == nothing)
return;
/* Otherwise, check what we have at the place of the call site */
/* No landing pad => no cleanups or handlers. */
if (action->landing_pad == 0)
{
action->kind = nothing;
return;
}
/* Landing pad + null table entry => only cleanups. */
else if (action->table_entry == 0)
{
action->kind = cleanup;
return;
}
/* Landing pad + Table entry => handlers + possible cleanups. */
else
{
const unsigned char * p = action->table_entry;
_Unwind_Sword ar_filter, ar_disp;
action->kind = nothing;
while (1)
{
p = read_sleb128 (p, &ar_filter);
read_sleb128 (p, &ar_disp);
/* Don't assign p here, as it will be incremented by ar_disp
below. */
/* Null filters are for cleanups. */
if (ar_filter == 0)
action->kind = cleanup;
/* Positive filters are for regular handlers. */
else if (ar_filter > 0)
{
/* See if the filter we have is for an exception which matches
the one we are propagating. */
_Unwind_Ptr eid = get_ttype_entry_for (region, ar_filter);
if (eid == gnat_exception->id
|| eid == GNAT_ALL_OTHERS
|| (eid == GNAT_OTHERS && gnat_exception->handled_by_others))
{
action->ttype_filter = ar_filter;
action->ttype_entry = eid;
action->kind = handler;
return;
}
}
/* Negative filter values are for C++ exception specifications.
Should not be there for Ada :/ */
else
db (DB_ERR, "========> Err, filter < 0 for Ada/dwarf\n");
if (ar_disp == 0)
return;
p += ar_disp;
}
}
}
