/* The implementation of exception handling primitives for Objective-C.
- Copyright (C) 2004 Free Software Foundation, Inc.
+ Copyright (C) 2004, 2005, 2007, 2008, 2009, 2010 Free Software Foundation, Inc.
This file is part of GCC.
GCC is free software; you can redistribute it and/or modify it
under the terms of the GNU General Public License as published by the
-Free Software Foundation; either version 2, or (at your option) any
+Free Software Foundation; either version 3, or (at your option) any
later version.
GCC is distributed in the hope that it will be useful, but WITHOUT
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
-along with GCC; see the file COPYING. If not, write to
-the Free Software Foundation, 59 Temple Place - Suite 330,
-Boston, MA 02111-1307, USA. */
+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.
-/* As a special exception, if you link this library with files compiled
- with GCC to produce an executable, this does not cause the resulting
- executable to be covered by the GNU General Public License. This
- exception does not however invalidate any other reasons why the
- executable file might be covered by the GNU General Public License. */
+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/>. */
+#include "objc-private/common.h"
#include <stdlib.h>
#include "config.h"
-#include "objc/objc-api.h"
+#include "objc/runtime.h"
+#include "objc/objc-exception.h"
#include "unwind.h"
#include "unwind-pe.h"
+#include <string.h> /* For memcpy */
+
+/* 'is_kind_of_exception_matcher' is our default exception matcher -
+ it determines if the object 'exception' is of class 'catch_class',
+ or of a subclass. */
+static int
+is_kind_of_exception_matcher (Class catch_class, id exception)
+{
+ /* NULL catch_class is catch-all (eg, @catch (id object)). */
+ if (catch_class == Nil)
+ return 1;
+
+ /* If exception is nil (eg, @throw nil;), then it can only be
+ catched by a catch-all (eg, @catch (id object)). */
+ if (exception != nil)
+ {
+ Class c;
+
+ for (c = exception->class_pointer; c != Nil;
+ c = class_getSuperclass (c))
+ if (c == catch_class)
+ return 1;
+ }
+ return 0;
+}
+
+/* The exception matcher currently in use. */
+static objc_exception_matcher
+__objc_exception_matcher = is_kind_of_exception_matcher;
+
+objc_exception_matcher
+objc_setExceptionMatcher (objc_exception_matcher new_matcher)
+{
+ objc_exception_matcher old_matcher = __objc_exception_matcher;
+ __objc_exception_matcher = new_matcher;
+ return old_matcher;
+}
+
+/* The uncaught exception handler currently in use. */
+static objc_uncaught_exception_handler
+__objc_uncaught_exception_handler = NULL;
+
+objc_uncaught_exception_handler
+objc_setUncaughtExceptionHandler (objc_uncaught_exception_handler
+ new_handler)
+{
+ objc_uncaught_exception_handler old_handler
+ = __objc_uncaught_exception_handler;
+ __objc_uncaught_exception_handler = new_handler;
+ return old_handler;
+}
+
\f
+#ifdef __ARM_EABI_UNWINDER__
+
+const _Unwind_Exception_Class __objc_exception_class
+ = {'G', 'N', 'U', 'C', 'O', 'B', 'J', 'C'};
+
+#else
+
/* This is the exception class we report -- "GNUCOBJC". */
-#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')
+static const _Unwind_Exception_Class __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');
+
+#endif
/* This is the object that is passed around by the Objective C runtime
to represent the exception in flight. */
-
struct ObjcException
{
/* This bit is needed in order to interact with the unwind runtime. */
struct _Unwind_Exception base;
- /* The actual object we want to throw. */
+ /* The actual object we want to throw. Note: must come immediately
+ after unwind header. */
id value;
+#ifdef __ARM_EABI_UNWINDER__
+ /* Note: we use the barrier cache defined in the unwind control
+ block for ARM EABI. */
+#else
/* Cache some internal unwind data between phase 1 and phase 2. */
_Unwind_Ptr landingPad;
int handlerSwitchValue;
+#endif
};
\f
parse_lsda_header (struct _Unwind_Context *context, const unsigned char *p,
struct lsda_header_info *info)
{
- _Unwind_Word tmp;
+ _uleb128_t tmp;
unsigned char lpstart_encoding;
info->Start = (context ? _Unwind_GetRegionStart (context) : 0);
- /* Find @LPStart, the base to which landing pad offsets are relative. */
+ /* Find @LPStart, the base to which landing pad offsets are
+ relative. */
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;
- /* Find @TType, the base of the handler and exception spec type data. */
+ /* Find @TType, the base of the handler and exception spec type
+ data. */
info->ttype_encoding = *p++;
if (info->ttype_encoding != DW_EH_PE_omit)
{
+#if _GLIBCXX_OVERRIDE_TTYPE_ENCODING
+ /* Older ARM EABI toolchains set this value incorrectly, so use a
+ hardcoded OS-specific format. */
+ info->ttype_encoding = _GLIBCXX_OVERRIDE_TTYPE_ENCODING;
+#endif
p = read_uleb128 (p, &tmp);
info->TType = p + tmp;
}
read_encoded_value_with_base (info->ttype_encoding, info->ttype_base,
info->TType - i, &ptr);
- /* NULL ptr means catch-all. */
+ /* NULL ptr means catch-all. Note that if the class is not found,
+ this will abort the program. */
if (ptr)
- return objc_get_class ((const char *) ptr);
+ return objc_getRequiredClass ((const char *) ptr);
else
return 0;
}
-/* Like unto the method of the same name on Object, but takes an id. */
-/* ??? Does this bork the meta-type system? Can/should we look up an
- isKindOf method on the id? */
-
-static int
-isKindOf (id value, Class target)
-{
- Class c;
-
- /* NULL target is catch-all. */
- if (target == 0)
- return 1;
-
- for (c = value->class_pointer; c; c = class_get_super_class (c))
- if (c == target)
- return 1;
- return 0;
-}
-
/* Using a different personality function name causes link failures
- when trying to mix code using different exception handling models. */
+ when trying to mix code using different exception handling
+ models. */
#ifdef SJLJ_EXCEPTIONS
#define PERSONALITY_FUNCTION __gnu_objc_personality_sj0
#define __builtin_eh_return_data_regno(x) x
#define PERSONALITY_FUNCTION __gnu_objc_personality_v0
#endif
+#ifdef __ARM_EABI_UNWINDER__
+
+#define CONTINUE_UNWINDING \
+ do \
+ { \
+ if (__gnu_unwind_frame(ue_header, context) != _URC_OK) \
+ return _URC_FAILURE; \
+ return _URC_CONTINUE_UNWIND; \
+ } \
+ while (0)
+
+_Unwind_Reason_Code
+PERSONALITY_FUNCTION (_Unwind_State state,
+ struct _Unwind_Exception *ue_header,
+ struct _Unwind_Context *context)
+#else
+
+#define CONTINUE_UNWINDING return _URC_CONTINUE_UNWIND
+
_Unwind_Reason_Code
PERSONALITY_FUNCTION (int version,
_Unwind_Action actions,
_Unwind_Exception_Class exception_class,
struct _Unwind_Exception *ue_header,
struct _Unwind_Context *context)
+#endif
{
struct ObjcException *xh = (struct ObjcException *) ue_header;
const unsigned char *p;
_Unwind_Ptr landing_pad, ip;
int handler_switch_value;
- int saw_cleanup = 0, saw_handler;
+ int saw_cleanup = 0, saw_handler, foreign_exception;
void *return_object;
+ int ip_before_insn = 0;
+
+#ifdef __ARM_EABI_UNWINDER__
+ _Unwind_Action actions;
+
+ switch (state & _US_ACTION_MASK)
+ {
+ case _US_VIRTUAL_UNWIND_FRAME:
+ actions = _UA_SEARCH_PHASE;
+ break;
+
+ case _US_UNWIND_FRAME_STARTING:
+ actions = _UA_CLEANUP_PHASE;
+ if (!(state & _US_FORCE_UNWIND)
+ && ue_header->barrier_cache.sp == _Unwind_GetGR (context, 13))
+ actions |= _UA_HANDLER_FRAME;
+ break;
+
+ case _US_UNWIND_FRAME_RESUME:
+ CONTINUE_UNWINDING;
+ break;
+
+ default:
+ abort();
+ }
+ actions |= state & _US_FORCE_UNWIND;
+
+ /* TODO: Foreign exceptions need some attention (e.g. rethrowing
+ doesn't work). */
+ foreign_exception = 0;
+ /* The dwarf unwinder assumes the context structure holds things
+ like the function and LSDA pointers. The ARM implementation
+ caches these in the exception header (UCB). To avoid rewriting
+ everything we make the virtual IP register point at the UCB. */
+ ip = (_Unwind_Ptr) ue_header;
+ _Unwind_SetGR (context, 12, ip);
+
+#else /* !__ARM_EABI_UNWINDER. */
/* Interface version check. */
if (version != 1)
return _URC_FATAL_PHASE1_ERROR;
+
+ foreign_exception = (exception_class != __objc_exception_class);
+#endif
/* Shortcut for phase 2 found handler for domestic exception. */
if (actions == (_UA_CLEANUP_PHASE | _UA_HANDLER_FRAME)
- && exception_class == __objc_exception_class)
+ && !foreign_exception)
{
+#ifdef __ARM_EABI_UNWINDER__
+ handler_switch_value = (int) ue_header->barrier_cache.bitpattern[1];
+ landing_pad = (_Unwind_Ptr) ue_header->barrier_cache.bitpattern[3];
+#else
handler_switch_value = xh->handlerSwitchValue;
landing_pad = xh->landingPad;
+#endif
goto install_context;
}
/* If no LSDA, then there are no handlers or cleanups. */
if (! language_specific_data)
- return _URC_CONTINUE_UNWIND;
+ CONTINUE_UNWINDING;
/* Parse the LSDA header. */
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;
+#ifdef HAVE_GETIPINFO
+ ip = _Unwind_GetIPInfo (context, &ip_before_insn);
+#else
+ ip = _Unwind_GetIP (context);
+#endif
+ if (!ip_before_insn)
+ --ip;
landing_pad = 0;
action_record = 0;
handler_switch_value = 0;
#ifdef SJLJ_EXCEPTIONS
/* The given "IP" is an index into the call-site table, with two
exceptions -- -1 means no-action, and 0 means terminate. But
- since we're using uleb128 values, we've not got random access
- to the array. */
+ since we're using uleb128 values, we've not got random access to
+ the array. */
if ((int) ip < 0)
return _URC_CONTINUE_UNWIND;
else
{
- _Unwind_Word cs_lp, cs_action;
+ _uleb128_t cs_lp, cs_action;
do
{
p = read_uleb128 (p, &cs_lp);
goto found_something;
}
#else
- /* Search the call-site table for the action associated with this IP. */
+ /* Search the call-site table for the action associated with this
+ IP. */
while (p < info.action_table)
{
_Unwind_Ptr cs_start, cs_len, cs_lp;
- _Unwind_Word cs_action;
+ _uleb128_t cs_action;
- /* Note that all call-site encodings are "absolute" displacements. */
+ /* Note that all call-site encodings are "absolute"
+ displacements. */
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);
#endif /* SJLJ_EXCEPTIONS */
/* If ip is not present in the table, C++ would call terminate. */
- /* ??? As with Java, it's perhaps better to tweek the LSDA to
- that no-action is mapped to no-entry. */
- return _URC_CONTINUE_UNWIND;
+ /* ??? As with Java, it's perhaps better to tweek the LSDA to that
+ no-action is mapped to no-entry. */
+ CONTINUE_UNWINDING;
found_something:
saw_cleanup = 0;
if (landing_pad == 0)
{
- /* If ip is present, and has a null landing pad, there are
- no cleanups or handlers to be run. */
+ /* If ip is present, and has a null landing pad, there are no
+ cleanups or handlers to be run. */
}
else if (action_record == 0)
{
else
{
/* Otherwise we have a catch handler. */
- _Unwind_Sword ar_filter, ar_disp;
+ _sleb128_t ar_filter, ar_disp;
while (1)
{
}
/* During forced unwinding, we only run cleanups. With a
- foreign exception class, we have no class info to match. */
- else if ((actions & _UA_FORCE_UNWIND)
- || exception_class != __objc_exception_class)
+ foreign exception class, we have no class info to
+ match. */
+ else if ((actions & _UA_FORCE_UNWIND) || foreign_exception)
;
else if (ar_filter > 0)
{
/* Positive filter values are handlers. */
-
Class catch_type = get_ttype_entry (&info, ar_filter);
- if (isKindOf (xh->value, catch_type))
+ if ((*__objc_exception_matcher) (catch_type, xh->value))
{
handler_switch_value = ar_filter;
saw_handler = 1;
}
if (! saw_handler && ! saw_cleanup)
- return _URC_CONTINUE_UNWIND;
+ CONTINUE_UNWINDING;
if (actions & _UA_SEARCH_PHASE)
{
if (!saw_handler)
- return _URC_CONTINUE_UNWIND;
+ CONTINUE_UNWINDING;
- /* For domestic exceptions, we cache data from phase 1 for phase 2. */
- if (exception_class == __objc_exception_class)
+ /* For domestic exceptions, we cache data from phase 1 for phase
+ 2. */
+ if (!foreign_exception)
{
+#ifdef __ARM_EABI_UNWINDER__
+ ue_header->barrier_cache.sp = _Unwind_GetGR (context, 13);
+ ue_header->barrier_cache.bitpattern[1] = (_uw) handler_switch_value;
+ ue_header->barrier_cache.bitpattern[3] = (_uw) landing_pad;
+#else
xh->handlerSwitchValue = handler_switch_value;
xh->landingPad = landing_pad;
+#endif
}
return _URC_HANDLER_FOUND;
}
}
void
-objc_exception_throw (id value)
+objc_exception_throw (id exception)
{
struct ObjcException *header = calloc (1, sizeof (*header));
- header->base.exception_class = __objc_exception_class;
+
+ memcpy (&header->base.exception_class, &__objc_exception_class,
+ sizeof (__objc_exception_class));
header->base.exception_cleanup = __objc_exception_cleanup;
- header->value = value;
+ header->value = exception;
#ifdef SJLJ_EXCEPTIONS
_Unwind_SjLj_RaiseException (&header->base);
_Unwind_RaiseException (&header->base);
#endif
- /* Some sort of unwinding error. */
+ /* No exception handler was installed. Call the uncaught exception
+ handler if any is defined. */
+ if (__objc_uncaught_exception_handler != 0)
+ {
+ (*__objc_uncaught_exception_handler) (exception);
+ }
+
abort ();
}
+
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