#include <stdlib.h>
#include "config.h"
#include "objc/objc-api.h"
#include "unwind.h"
#include "unwind-pe.h"
#define __objc_exception_class \
((((((((_Unwind_Exception_Class) 'G' \
<< 8 | (_Unwind_Exception_Class) 'N') \
<< 8 | (_Unwind_Exception_Class) 'U') \
<< 8 | (_Unwind_Exception_Class) 'C') \
<< 8 | (_Unwind_Exception_Class) 'O') \
<< 8 | (_Unwind_Exception_Class) 'B') \
<< 8 | (_Unwind_Exception_Class) 'J') \
<< 8 | (_Unwind_Exception_Class) 'C')
struct ObjcException
{
struct _Unwind_Exception base;
id value;
_Unwind_Ptr landingPad;
int handlerSwitchValue;
};
struct lsda_header_info
{
_Unwind_Ptr Start;
_Unwind_Ptr LPStart;
_Unwind_Ptr ttype_base;
const unsigned char *TType;
const unsigned char *action_table;
unsigned char ttype_encoding;
unsigned char call_site_encoding;
};
static const unsigned char *
parse_lsda_header (struct _Unwind_Context *context, const unsigned char *p,
struct lsda_header_info *info)
{
_Unwind_Word tmp;
unsigned char lpstart_encoding;
info->Start = (context ? _Unwind_GetRegionStart (context) : 0);
lpstart_encoding = *p++;
if (lpstart_encoding != DW_EH_PE_omit)
p = read_encoded_value (context, lpstart_encoding, p, &info->LPStart);
else
info->LPStart = info->Start;
info->ttype_encoding = *p++;
if (info->ttype_encoding != DW_EH_PE_omit)
{
p = read_uleb128 (p, &tmp);
info->TType = p + tmp;
}
else
info->TType = 0;
info->call_site_encoding = *p++;
p = read_uleb128 (p, &tmp);
info->action_table = p + tmp;
return p;
}
static Class
get_ttype_entry (struct lsda_header_info *info, _Unwind_Word i)
{
_Unwind_Ptr ptr;
i *= size_of_encoded_value (info->ttype_encoding);
read_encoded_value_with_base (info->ttype_encoding, info->ttype_base,
info->TType - i, &ptr);
if (ptr)
return objc_get_class ((const char *) ptr);
else
return 0;
}
static int
isKindOf (id value, Class target)
{
Class c;
if (target == 0)
return 1;
for (c = value->class_pointer; c; c = class_get_super_class (c))
if (c == target)
return 1;
return 0;
}
#ifdef SJLJ_EXCEPTIONS
#define PERSONALITY_FUNCTION __gnu_objc_personality_sj0
#define __builtin_eh_return_data_regno(x) x
#else
#define PERSONALITY_FUNCTION __gnu_objc_personality_v0
#endif
_Unwind_Reason_Code
PERSONALITY_FUNCTION (int version,
_Unwind_Action actions,
_Unwind_Exception_Class exception_class,
struct _Unwind_Exception *ue_header,
struct _Unwind_Context *context)
{
struct ObjcException *xh = (struct ObjcException *) ue_header;
struct lsda_header_info info;
const unsigned char *language_specific_data;
const unsigned char *action_record;
const unsigned char *p;
_Unwind_Ptr landing_pad, ip;
int handler_switch_value;
int saw_cleanup, saw_handler;
if (version != 1)
return _URC_FATAL_PHASE1_ERROR;
if (actions == (_UA_CLEANUP_PHASE | _UA_HANDLER_FRAME)
&& exception_class == __objc_exception_class)
{
handler_switch_value = xh->handlerSwitchValue;
landing_pad = xh->landingPad;
goto install_context;
}
language_specific_data = (const unsigned char *)
_Unwind_GetLanguageSpecificData (context);
if (! language_specific_data)
return _URC_CONTINUE_UNWIND;
p = parse_lsda_header (context, language_specific_data, &info);
info.ttype_base = base_of_encoded_value (info.ttype_encoding, context);
ip = _Unwind_GetIP (context) - 1;
landing_pad = 0;
action_record = 0;
handler_switch_value = 0;
#ifdef SJLJ_EXCEPTIONS
if ((int) ip < 0)
return _URC_CONTINUE_UNWIND;
else
{
_Unwind_Word cs_lp, cs_action;
do
{
p = read_uleb128 (p, &cs_lp);
p = read_uleb128 (p, &cs_action);
}
while (--ip);
landing_pad = cs_lp + 1;
if (cs_action)
action_record = info.action_table + cs_action - 1;
goto found_something;
}
#else
while (p < info.action_table)
{
_Unwind_Ptr cs_start, cs_len, cs_lp;
_Unwind_Word cs_action;
p = read_encoded_value (0, info.call_site_encoding, p, &cs_start);
p = read_encoded_value (0, info.call_site_encoding, p, &cs_len);
p = read_encoded_value (0, info.call_site_encoding, p, &cs_lp);
p = read_uleb128 (p, &cs_action);
if (ip < info.Start + cs_start)
p = info.action_table;
else if (ip < info.Start + cs_start + cs_len)
{
if (cs_lp)
landing_pad = info.LPStart + cs_lp;
if (cs_action)
action_record = info.action_table + cs_action - 1;
goto found_something;
}
}
#endif
return _URC_CONTINUE_UNWIND;
found_something:
saw_cleanup = 0;
saw_handler = 0;
if (landing_pad == 0)
{
}
else if (action_record == 0)
{
saw_cleanup = 1;
}
else
{
_Unwind_Sword ar_filter, ar_disp;
while (1)
{
p = action_record;
p = read_sleb128 (p, &ar_filter);
read_sleb128 (p, &ar_disp);
if (ar_filter == 0)
{
saw_cleanup = 1;
}
else if ((actions & _UA_FORCE_UNWIND)
|| exception_class != __objc_exception_class)
;
else if (ar_filter > 0)
{
Class catch_type = get_ttype_entry (&info, ar_filter);
if (isKindOf (xh->value, catch_type))
{
handler_switch_value = ar_filter;
saw_handler = 1;
break;
}
}
else
{
abort ();
}
if (ar_disp == 0)
break;
action_record = p + ar_disp;
}
}
if (! saw_handler && ! saw_cleanup)
return _URC_CONTINUE_UNWIND;
if (actions & _UA_SEARCH_PHASE)
{
if (!saw_handler)
return _URC_CONTINUE_UNWIND;
if (exception_class == __objc_exception_class)
{
xh->handlerSwitchValue = handler_switch_value;
xh->landingPad = landing_pad;
}
return _URC_HANDLER_FOUND;
}
install_context:
_Unwind_SetGR (context, __builtin_eh_return_data_regno (0),
__builtin_extend_pointer (xh->value));
_Unwind_SetGR (context, __builtin_eh_return_data_regno (1),
handler_switch_value);
_Unwind_SetIP (context, landing_pad);
return _URC_INSTALL_CONTEXT;
}
static void
__objc_exception_cleanup (_Unwind_Reason_Code code __attribute__((unused)),
struct _Unwind_Exception *exc)
{
free (exc);
}
void
objc_exception_throw (id value)
{
struct ObjcException *header = calloc (1, sizeof (*header));
header->base.exception_class = __objc_exception_class;
header->base.exception_cleanup = __objc_exception_cleanup;
header->value = value;
#ifdef SJLJ_EXCEPTIONS
_Unwind_SjLj_RaiseException (&header->base);
#else
_Unwind_RaiseException (&header->base);
#endif
abort ();
}