ObjFW  Check-in [d55f62409f]

/*
 * Define HAVE_DWARF_EXCEPTIONS if HAVE_SEH_EXCEPTIONS is defined, as SEH
 * exceptions are implemented as a wrapper around DWARF exceptions.
 */
#ifdef HAVE_SEH_EXCEPTIONS
# define HAVE_DWARF_EXCEPTIONS
#endif

#if defined(OF_ARM) && !defined(__ARM_DWARF_EH__)
# define HAVE_ARM_EHABI_EXCEPTIONS
#endif

#ifdef HAVE_DWARF_EXCEPTIONS
struct _Unwind_Context;
typedef enum {
	_URC_OK		  = 0,
	_URC_END_OF_STACK = 5
}_Unwind_Reason_Code;

struct backtrace_ctx {
	void **backtrace;
	uint8_t i;
};

extern _Unwind_Reason_Code _Unwind_Backtrace(
    _Unwind_Reason_Code(*)(struct _Unwind_Context*, void*), void*);
# ifndef HAVE_ARM_EHABI_EXCEPTIONS
extern uintptr_t _Unwind_GetIP(struct _Unwind_Context*);
# else
extern int _Unwind_VRS_Get(struct _Unwind_Context*, int, uint32_t, int, void*);
# endif
#endif

#if !defined(HAVE_STRERROR_R) && defined(OF_HAVE_THREADS)
static of_mutex_t mutex;

static void __attribute__((__constructor__))

#ifdef HAVE_DWARF_EXCEPTIONS
static _Unwind_Reason_Code
backtrace_callback(struct _Unwind_Context *ctx, void *data)
{
	struct backtrace_ctx *bt = data;

	if (bt->i < OF_BACKTRACE_SIZE) {
# ifndef HAVE_ARM_EHABI_EXCEPTIONS
		bt->backtrace[bt->i++] = (void*)_Unwind_GetIP(ctx);
# else
		uintptr_t ip;

		_Unwind_VRS_Get(ctx, 0, 15, 0, &ip);
		bt->backtrace[bt->i++] = (void*)(ip & ~1);


# endif
		return _URC_OK;
	}

	return _URC_END_OF_STACK;
}
#endif

# define _Unwind_RaiseException _Unwind_SjLj_RaiseException
# define __builtin_eh_return_data_regno(i) (i)
#elif defined(HAVE_SEH_EXCEPTIONS)
# define PERSONALITY gnu_objc_personality
#else
# error Unknown exception type!
#endif

#if defined(OF_ARM) && !defined(__ARM_DWARF_EH__)
# define HAVE_ARM_EHABI_EXCEPTIONS
#endif

static const uint64_t objc_exception_class = 0x474E55434F424A43; /* GNUCOBJC */

#define _UA_SEARCH_PHASE  0x01
#define _UA_CLEANUP_PHASE 0x02
#define _UA_HANDLER_FRAME 0x04
#define _UA_FORCE_UNWIND  0x08

	_URC_FAILURE		= 9
} _Unwind_Reason_Code;

struct objc_exception {
	struct _Unwind_Exception {
		uint64_t class;
		void (*cleanup)(_Unwind_Reason_Code, struct _Unwind_Exception*);
#ifndef HAVE_ARM_EHABI_EXCEPTIONS
# ifdef HAVE_SEH_EXCEPTIONS
		uint64_t private[6];
# else
		/*
		 * The Itanium Exception ABI says to have those and never touch
		 * them.
		 */
		uint64_t private1, private2;
# endif
#else
		/* From "Exception Handling ABI for the ARM(R) Architecture" */
		struct {
			uint32_t reserved1, reserved2, reserved3, reserved4;
			uint32_t reserved;
		} unwinder_cache;
		struct {
			uint32_t sp;
			uint32_t bitpattern[5];
		} barrier_cache;
		struct {
			uint32_t bitpattern[4];
		} cleanup_cache;
		struct {
			uint32_t fnstart;
			uint32_t *ehtp;
			uint32_t additional;
			uint32_t reserved1;
		} pr_cache;
		long long int : 0;










#endif
	} exception;
	id object;
#ifndef HAVE_ARM_EHABI_EXCEPTIONS
	uintptr_t landingpad;
	intptr_t filter;
#endif
};

struct lsda {
	uintptr_t region_start, landingpads_start;

extern _Unwind_Reason_Code _Unwind_RaiseException(struct _Unwind_Exception*);
extern void _Unwind_DeleteException(struct _Unwind_Exception*);
extern void* _Unwind_GetLanguageSpecificData(struct _Unwind_Context*);
extern uintptr_t _Unwind_GetRegionStart(struct _Unwind_Context*);
extern uintptr_t _Unwind_GetDataRelBase(struct _Unwind_Context*);
extern uintptr_t _Unwind_GetTextRelBase(struct _Unwind_Context*);

#ifndef HAVE_ARM_EHABI_EXCEPTIONS
# define CONTINUE_UNWIND return _URC_CONTINUE_UNWIND

extern uintptr_t _Unwind_GetIP(struct _Unwind_Context*);
extern void _Unwind_SetIP(struct _Unwind_Context*, uintptr_t);
extern void _Unwind_SetGR(struct _Unwind_Context*, int, uintptr_t);
#else
extern _Unwind_Reason_Code __gnu_unwind_frame(struct _Unwind_Exception*,
    struct _Unwind_Context*);
extern int _Unwind_VRS_Get(struct _Unwind_Context*, int, uint32_t, int, void*);
extern int _Unwind_VRS_Set(struct _Unwind_Context*, int, uint32_t, int, void*);

# define CONTINUE_UNWIND					\
	{							\

static inline void
_Unwind_SetIP(struct _Unwind_Context *ctx, uintptr_t value)
{
	uintptr_t thumb = _Unwind_GetGR(ctx, 15) & 1;
	_Unwind_SetGR(ctx, 15, (value | thumb));
}






#endif

#ifdef HAVE_SEH_EXCEPTIONS
extern EXCEPTION_DISPOSITION _GCC_specific_handler(PEXCEPTION_RECORD, void*,
    PCONTEXT, PDISPATCHER_CONTEXT, _Unwind_Reason_Code(*)(int, int, uint64_t,
    struct _Unwind_Exception*, struct _Unwind_Context*));
#endif

		abort();
	}
#undef READ

	return value;
}

#ifndef HAVE_ARM_EHABI_EXCEPTIONS
static uint64_t
resolve_value(uint64_t value, uint8_t enc, const uint8_t *start, uint64_t base)
{
	if (value == 0)
		return 0;

	value += ((enc & 0x70) == DW_EH_PE_pcrel ? (uintptr_t)start : base);

		if (filter > 0 && !(actions & _UA_FORCE_UNWIND) && !foreign) {
			Class class;
			const char *className;
			uintptr_t c;
			const uint8_t *tmp;

#ifndef HAVE_ARM_EHABI_EXCEPTIONS
			uintptr_t i;

			i = filter * size_for_encoding(lsda->typestable_enc);
			tmp = lsda->typestable - i;
			c = (uintptr_t)read_value(lsda->typestable_enc, &tmp);
			c = (uintptr_t)resolve_value(c, lsda->typestable_enc,
			    lsda->typestable - i, lsda->typestable_base);
#else
			tmp = lsda->typestable - (filter * 4);
			c = *(uintptr_t*)(void*)tmp;

			if (c != 0) {
				c += (uintptr_t)tmp;
# if defined(OF_LINUX) || defined(OF_NETBSD)
				c = *(uintptr_t*)c;
# endif
			}








#endif

			className = (const char*)c;

			if (className != NULL && *className != '\0' &&
			    strcmp(className, "@id") != 0)
				class = objc_getRequiredClass(className);

		else
			abort();
	} while (displacement != 0);

	return 0;
}

#ifndef HAVE_ARM_EHABI_EXCEPTIONS
# ifdef HAVE_SEH_EXCEPTIONS
static
# endif
_Unwind_Reason_Code
PERSONALITY(int version, int actions, uint64_t ex_class,
    struct _Unwind_Exception *ex, struct _Unwind_Context *ctx)
{
#else
_Unwind_Reason_Code
PERSONALITY(uint32_t state, struct _Unwind_Exception *ex,
    struct _Unwind_Context *ctx)
{
	int version = 1;
	uint64_t ex_class = ex->class;
	int actions;

	case 2:	/* _US_UNWIND_FRAME_RESUME */
		CONTINUE_UNWIND;
	default:
		return _URC_FAILURE;
	}

	_Unwind_SetGR(ctx, 12, (uintptr_t)ex);








#endif
	struct objc_exception *e = (struct objc_exception*)ex;
	bool foreign = (ex_class != objc_exception_class);
	const uint8_t *lsda_addr, *actionrecords;
	struct lsda lsda;
	uintptr_t landingpad = 0;
	uint8_t found = 0;

	if (actions & _UA_HANDLER_FRAME && !foreign) {
		/*
		 * For handlers, reg #0 must be the exception's object and reg
		 * #1 the filter.
		 */
		_Unwind_SetGR(ctx, __builtin_eh_return_data_regno(0),
		    (uintptr_t)e->object);
#ifndef HAVE_ARM_EHABI_EXCEPTIONS
		_Unwind_SetGR(ctx, __builtin_eh_return_data_regno(1),
		    e->filter);
		_Unwind_SetIP(ctx, e->landingpad);
#else
		_Unwind_SetGR(ctx, __builtin_eh_return_data_regno(1),
		    ex->barrier_cache.bitpattern[1]);
		_Unwind_SetIP(ctx, ex->barrier_cache.bitpattern[3]);




#endif

		_Unwind_DeleteException(ex);

		return _URC_INSTALL_CONTEXT;
	}

		CONTINUE_UNWIND;

	if (actions & _UA_SEARCH_PHASE) {
		if (!(found & HANDLER_FOUND) || foreign)
			CONTINUE_UNWIND;

		/* Cache it so we don't have to search it again in phase 2 */
#ifndef HAVE_ARM_EHABI_EXCEPTIONS
		e->landingpad = landingpad;
		e->filter = filter;
#else
		ex->barrier_cache.sp = _Unwind_GetGR(ctx, 13);
		ex->barrier_cache.bitpattern[1] = filter;
		ex->barrier_cache.bitpattern[3] = landingpad;



#endif

		return _URC_HANDLER_FOUND;
	} else if (actions & _UA_CLEANUP_PHASE) {
		if (!(found & CLEANUP_FOUND))
			CONTINUE_UNWIND;