/* The implementation of exception handling primitives for Objective-C.
- Copyright (C) 2004, 2005, 2007, 2008, 2009 Free Software Foundation, Inc.
+ Copyright (C) 2004-2020 Free Software Foundation, Inc.
This file is part of GCC.
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__
/* 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. Note: must come immediately after
- unwind header. */
+ /* 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. */
+ /* 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;
unsigned char call_site_encoding;
};
-/* This hook allows libraries to sepecify special actions when an
- exception is thrown without a handler in place.
- */
-void (*_objc_unexpected_exception) (id exception); /* !T:SAFE */
-
static const unsigned char *
parse_lsda_header (struct _Unwind_Context *context, const unsigned char *p,
struct lsda_header_info *info)
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;
}
return p;
}
-#ifdef __ARM_EABI_UNWINDER__
-
-static Class
-get_ttype_entry (struct lsda_header_info *info, _uleb128_t i)
-{
- _Unwind_Ptr ptr;
-
- ptr = (_Unwind_Ptr) (info->TType - (i * 4));
- ptr = _Unwind_decode_target2 (ptr);
-
- if (ptr)
- return objc_get_class ((const char *) ptr);
- else
- return 0;
-}
-
-#else
-
static Class
get_ttype_entry (struct lsda_header_info *info, _Unwind_Word i)
{
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;
}
-#endif
-
-/* 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. */
-#ifdef SJLJ_EXCEPTIONS
+ when trying to mix code using different exception handling
+ models. */
+#ifdef __USING_SJLJ_EXCEPTIONS__
#define PERSONALITY_FUNCTION __gnu_objc_personality_sj0
#define __builtin_eh_return_data_regno(x) x
+#elif defined(__SEH__)
+#define PERSONALITY_FUNCTION __gnu_objc_personality_imp
#else
#define PERSONALITY_FUNCTION __gnu_objc_personality_v0
#endif
while (0)
_Unwind_Reason_Code
+__attribute__((target ("general-regs-only")))
PERSONALITY_FUNCTION (_Unwind_State state,
struct _Unwind_Exception *ue_header,
struct _Unwind_Context *context)
#define CONTINUE_UNWINDING return _URC_CONTINUE_UNWIND
+#if defined (__SEH__) && !defined (__USING_SJLJ_EXCEPTIONS__)
+static
+#endif
_Unwind_Reason_Code
PERSONALITY_FUNCTION (int version,
_Unwind_Action actions,
}
actions |= state & _US_FORCE_UNWIND;
- /* TODO: Foreign exceptions need some attention (e.g. rethrowing doesn't
- work). */
+ /* 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. */
+ /* 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);
action_record = 0;
handler_switch_value = 0;
-#ifdef SJLJ_EXCEPTIONS
+#ifdef __USING_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
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;
_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);
goto found_something;
}
}
-#endif /* SJLJ_EXCEPTIONS */
+#endif /* __USING_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. */
+ /* ??? As with Java, it's perhaps better to tweek the LSDA to that
+ no-action is mapped to no-entry. */
CONTINUE_UNWINDING;
found_something:
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)
{
}
/* During forced unwinding, we only run cleanups. With a
- foreign exception class, we have no class info to match. */
+ 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)
CONTINUE_UNWINDING;
- /* For domestic exceptions, we cache data from phase 1 for phase 2. */
+ /* For domestic exceptions, we cache data from phase 1 for phase
+ 2. */
if (!foreign_exception)
{
#ifdef __ARM_EABI_UNWINDER__
}
void
-objc_exception_throw (id value)
+objc_exception_throw (id exception)
{
struct ObjcException *header = calloc (1, sizeof (*header));
-
+
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
+#ifdef __USING_SJLJ_EXCEPTIONS__
_Unwind_SjLj_RaiseException (&header->base);
#else
_Unwind_RaiseException (&header->base);
#endif
- /* Some sort of unwinding error. */
- if (_objc_unexpected_exception != 0)
+ /* No exception handler was installed. Call the uncaught exception
+ handler if any is defined. */
+ if (__objc_uncaught_exception_handler != 0)
{
- (*_objc_unexpected_exception) (value);
+ (*__objc_uncaught_exception_handler) (exception);
}
+
abort ();
}
+
+#if defined (__SEH__) && !defined (__USING_SJLJ_EXCEPTIONS__)
+EXCEPTION_DISPOSITION
+__gnu_objc_personality_seh0 (PEXCEPTION_RECORD ms_exc, void *this_frame,
+ PCONTEXT ms_orig_context,
+ PDISPATCHER_CONTEXT ms_disp)
+{
+ return _GCC_specific_handler (ms_exc, this_frame, ms_orig_context,
+ ms_disp, __gnu_objc_personality_imp);
+}
+#endif
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