C++ DUK_UNREF函数代码示例

DUK_INTERNAL void duk_default_panic_handler(duk_errcode_t code, const char *msg) {
#ifdef DUK_USE_FILE_IO
	DUK_FPRINTF(DUK_STDERR, "PANIC %ld: %s ("
#if defined(DUK_USE_PANIC_ABORT)
	            "calling abort"
#elif defined(DUK_USE_PANIC_EXIT)
	            "calling exit"
#elif defined(DUK_USE_PANIC_SEGFAULT)
	            "segfaulting on purpose"
#else
#error no DUK_USE_PANIC_xxx macro defined
#endif
	            ")\n", (long) code, (const char *) (msg ? msg : "null"));
	DUK_FFLUSH(DUK_STDERR);
#else
	/* omit print */
	DUK_UNREF(code);
	DUK_UNREF(msg);
#endif

#if defined(DUK_USE_PANIC_ABORT)
	DUK_ABORT();
#elif defined(DUK_USE_PANIC_EXIT)
	DUK_EXIT(-1);
#elif defined(DUK_USE_PANIC_SEGFAULT)
	/* exit() afterwards to satisfy "noreturn" */
	DUK_CAUSE_SEGFAULT();  /* SCANBUILD: "Dereference of null pointer", normal */
	DUK_EXIT(-1);
#else
#error no DUK_USE_PANIC_xxx macro defined
#endif

	DUK_UNREACHABLE();
}

static void duk__free_hobject_inner(duk_heap *heap, duk_hobject *h) {
	DUK_ASSERT(heap != NULL);
	DUK_ASSERT(h != NULL);

	DUK_FREE(heap, h->p);

	if (DUK_HOBJECT_IS_COMPILEDFUNCTION(h)) {
		duk_hcompiledfunction *f = (duk_hcompiledfunction *) h;
		DUK_UNREF(f);
		/* Currently nothing to free; 'data' is a heap object */
	} else if (DUK_HOBJECT_IS_NATIVEFUNCTION(h)) {
		duk_hnativefunction *f = (duk_hnativefunction *) h;
		DUK_UNREF(f);
		/* Currently nothing to free */
	} else if (DUK_HOBJECT_IS_THREAD(h)) {
		duk_hthread *t = (duk_hthread *) h;
		DUK_FREE(heap, t->valstack);
		DUK_FREE(heap, t->callstack);
		DUK_FREE(heap, t->catchstack);
		/* Don't free h->resumer because it exists in the heap.
		 * Callstack entries also contain function pointers which
		 * are not freed for the same reason.
		 */

		/* XXX: with 'caller' property the callstack would need
		 * to be unwound to update the 'caller' properties of
		 * functions in the callstack.
		 */
	}
}

DUK_LOCAL void duk__mark_hstring(duk_heap *heap, duk_hstring *h) {
	DUK_UNREF(heap);
	DUK_UNREF(h);

	DUK_DDD(DUK_DDDPRINT("duk__mark_hstring: %p", (void *) h));
	DUK_ASSERT(h);

	/* nothing to process */
}

DUK_INTERNAL void duk_free_hstring_inner(duk_heap *heap, duk_hstring *h) {
	DUK_ASSERT(heap != NULL);
	DUK_ASSERT(h != NULL);

	DUK_UNREF(heap);
	DUK_UNREF(h);

#if defined(DUK_USE_HSTRING_EXTDATA) && defined(DUK_USE_EXTSTR_FREE)
	if (DUK_HSTRING_HAS_EXTDATA(h)) {
		DUK_DDD(DUK_DDDPRINT("free extstr: hstring %!O, extdata: %p",
		                     h, DUK_HSTRING_GET_EXTDATA((duk_hstring_external *) h)));
		DUK_USE_EXTSTR_FREE((const void *) DUK_HSTRING_GET_EXTDATA((duk_hstring_external *) h));
	}
#endif
}

/* Shared helper to implement Object.getPrototypeOf and the ES6
 * Object.prototype.__proto__ getter.
 *
 * http://www.ecma-international.org/ecma-262/6.0/index.html#sec-get-object.prototype.__proto__
 */
DUK_INTERNAL duk_ret_t duk_bi_object_getprototype_shared(duk_context *ctx) {
	duk_hthread *thr = (duk_hthread *) ctx;
	duk_hobject *h;
	duk_hobject *proto;

	DUK_UNREF(thr);

	/* magic: 0=getter call, 1=Object.getPrototypeOf */
	if (duk_get_current_magic(ctx) == 0) {
		duk_push_this_coercible_to_object(ctx);
		duk_insert(ctx, 0);
	}

	h = duk_require_hobject_or_lfunc(ctx, 0);
	/* h is NULL for lightfunc */

	/* XXX: should the API call handle this directly, i.e. attempt
	 * to duk_push_hobject(ctx, null) would push a null instead?
	 * (On the other hand 'undefined' would be just as logical, but
	 * not wanted here.)
	 */

	if (h == NULL) {
		duk_push_hobject_bidx(ctx, DUK_BIDX_FUNCTION_PROTOTYPE);
	} else {
		proto = DUK_HOBJECT_GET_PROTOTYPE(thr->heap, h);
		if (proto) {
			duk_push_hobject(ctx, proto);
		} else {
			duk_push_null(ctx);
		}
	}
	return 1;
}

DUK_EXTERNAL duk_double_t duk_components_to_time(duk_context *ctx, duk_time_components *comp) {
	duk_double_t d;
	duk_double_t dparts[DUK_DATE_IDX_NUM_PARTS];
	duk_uint_t flags;

	DUK_ASSERT(ctx != NULL);
	DUK_ASSERT(comp != NULL);  /* XXX: or check? */
	DUK_UNREF(ctx);

	/* Match Date constructor behavior (with UTC time).  Month is given
	 * as zero-based.  Day-of-month is given as one-based so normalize
	 * it to zero-based as the internal conversion helpers expects all
	 * components to be zero-based.
	 */
	flags = 0;

	/* XXX: expensive conversion; use array format in API instead, or unify
	 * time provider and time API to use same struct?
	 */

	dparts[DUK_DATE_IDX_YEAR] = comp->year;
	dparts[DUK_DATE_IDX_MONTH] = comp->month;
	dparts[DUK_DATE_IDX_DAY] = comp->day - 1.0;
	dparts[DUK_DATE_IDX_HOUR] = comp->hours;
	dparts[DUK_DATE_IDX_MINUTE] = comp->minutes;
	dparts[DUK_DATE_IDX_SECOND] = comp->seconds;
	dparts[DUK_DATE_IDX_MILLISECOND] = comp->milliseconds;
	dparts[DUK_DATE_IDX_WEEKDAY] = 0;  /* ignored */

	d = duk_bi_date_get_timeval_from_dparts(dparts, flags);

	return d;
}

DUK_EXTERNAL void duk_time_to_components(duk_context *ctx, duk_double_t timeval, duk_time_components *comp) {
	duk_int_t parts[DUK_DATE_IDX_NUM_PARTS];
	duk_double_t dparts[DUK_DATE_IDX_NUM_PARTS];
	duk_uint_t flags;

	DUK_ASSERT(ctx != NULL);
	DUK_ASSERT(comp != NULL);  /* XXX: or check? */
	DUK_UNREF(ctx);

	/* Convert as one-based, but change month to zero-based to match the
	 * Ecmascript Date built-in behavior 1:1.
	 */
	flags = DUK_DATE_FLAG_ONEBASED | DUK_DATE_FLAG_NAN_TO_ZERO;

	duk_bi_date_timeval_to_parts(timeval, parts, dparts, flags);

	DUK_ASSERT(dparts[DUK_DATE_IDX_MONTH] >= 1.0 && dparts[DUK_DATE_IDX_MONTH] <= 12.0);
	comp->year = dparts[DUK_DATE_IDX_YEAR];
	comp->month = dparts[DUK_DATE_IDX_MONTH] - 1.0;
	comp->day = dparts[DUK_DATE_IDX_DAY];
	comp->hours = dparts[DUK_DATE_IDX_HOUR];
	comp->minutes = dparts[DUK_DATE_IDX_MINUTE];
	comp->seconds = dparts[DUK_DATE_IDX_SECOND];
	comp->milliseconds = dparts[DUK_DATE_IDX_MILLISECOND];
	comp->weekday = dparts[DUK_DATE_IDX_WEEKDAY];
}

DUK_EXTERNAL void duk_debugger_cooperate(duk_context *ctx) {
	duk_hthread *thr;
	duk_bool_t processed_messages;

	thr = (duk_hthread *) ctx;
	DUK_ASSERT(ctx != NULL);
	DUK_ASSERT(thr != NULL);
	DUK_ASSERT(thr->heap != NULL);

	if (!DUK_HEAP_IS_DEBUGGER_ATTACHED(thr->heap)) {
		return;
	}
	if (thr->callstack_top > 0 || thr->heap->dbg_processing) {
		/* Calling duk_debugger_cooperate() while Duktape is being
		 * called into is not supported.  This is not a 100% check
		 * but prevents any damage in most cases.
		 */
		return;
	}

	thr->heap->dbg_processing = 1;
	processed_messages = duk_debug_process_messages(thr, 1 /*no_block*/);
	thr->heap->dbg_processing = 0;
	DUK_UNREF(processed_messages);
}

DUK_LOCAL duk_ret_t duk__finalize_helper(duk_context *ctx, void *udata) {
	duk_hthread *thr;

	DUK_ASSERT(ctx != NULL);
	thr = (duk_hthread *) ctx;
	DUK_UNREF(udata);

	DUK_DDD(DUK_DDDPRINT("protected finalization helper running"));

	/* [... obj] */

	/* XXX: Finalizer lookup should traverse the prototype chain (to allow
	 * inherited finalizers) but should not invoke accessors or proxy object
	 * behavior.  At the moment this lookup will invoke proxy behavior, so
	 * caller must ensure that this function is not called if the target is
	 * a Proxy.
	 */

	duk_get_prop_stridx_short(ctx, -1, DUK_STRIDX_INT_FINALIZER);  /* -> [... obj finalizer] */
	if (!duk_is_callable(ctx, -1)) {
		DUK_DDD(DUK_DDDPRINT("-> no finalizer or finalizer not callable"));
		return 0;
	}
	duk_dup_m2(ctx);
	duk_push_boolean(ctx, DUK_HEAP_HAS_FINALIZER_NORESCUE(thr->heap));
	DUK_DDD(DUK_DDDPRINT("-> finalizer found, calling finalizer"));
	duk_call(ctx, 2);  /* [ ... obj finalizer obj heapDestruct ]  -> [ ... obj retval ] */
	DUK_DDD(DUK_DDDPRINT("finalizer finished successfully"));
	return 0;

	/* Note: we rely on duk_safe_call() to fix up the stack for the caller,
	 * so we don't need to pop stuff here.  There is no return value;
	 * caller determines rescued status based on object refcount.
	 */
}

int duk_bi_error_prototype_nop_setter(duk_context *ctx) {
	/* Attempt to write 'stack', 'fileName', 'lineNumber' is a silent no-op.
	 * User can use Object.defineProperty() to override this behavior.
	 */
	DUK_ASSERT_TOP(ctx, 1);  /* fixed arg count */
	DUK_UNREF(ctx);
	return 0;
}

DUK_LOCAL int duk__protected_compact_object(duk_context *ctx, void *udata) {
	duk_hobject *obj;
	/* XXX: for threads, compact value stack, call stack, catch stack? */

	DUK_UNREF(udata);
	obj = duk_known_hobject(ctx, -1);
	duk_hobject_compact_props((duk_hthread *) ctx, obj);
	return 0;
}

DUK_LOCAL void duk__get_this_regexp(duk_hthread *thr) {
	duk_hobject *h;

	duk_push_this(thr);
	h = duk_require_hobject_with_class(thr, -1, DUK_HOBJECT_CLASS_REGEXP);
	DUK_ASSERT(h != NULL);
	DUK_UNREF(h);
	duk_insert(thr, 0);  /* prepend regexp to valstack 0 index */
}

/* Default function to write a formatted log line.  Writes to stderr,
 * appending a newline to the log line.
 *
 * The argument is a buffer whose visible size contains the log message.
 * This function should avoid coercing the buffer to a string to avoid
 * string table traffic.
 */
DUK_INTERNAL duk_ret_t duk_bi_logger_prototype_raw(duk_context *ctx) {
	const char *data;
	duk_size_t data_len;

	DUK_UNREF(ctx);
	DUK_UNREF(data);
	DUK_UNREF(data_len);

#ifdef DUK_USE_FILE_IO
	data = (const char *) duk_require_buffer(ctx, 0, &data_len);
	DUK_FWRITE((const void *) data, 1, data_len, DUK_STDERR);
	DUK_FPUTC((int) '\n', DUK_STDERR);
	DUK_FFLUSH(DUK_STDERR);
#else
	/* nop */
#endif
	return 0;
}

	/*
	 *  String comparison (E5 Section 11.8.5, step 4), which
	 *  needs to compare codepoint by codepoint.
	 *
	 *  However, UTF-8 allows us to use strcmp directly: the shared
	 *  prefix will be encoded identically (UTF-8 has unique encoding)
	 *  and the first differing character can be compared with a simple
	 *  unsigned byte comparison (which strcmp does).
	 *
	 *  This will not work properly for non-xutf-8 strings, but this
	 *  is not an issue for compliance.
	 */

	DUK_ASSERT(h1 != NULL);
	DUK_ASSERT(h2 != NULL);

	return duk_js_data_compare((const duk_uint8_t *) DUK_HSTRING_GET_DATA(h1),
	                           (const duk_uint8_t *) DUK_HSTRING_GET_DATA(h2),
	                           (duk_size_t) DUK_HSTRING_GET_BYTELEN(h1),
	                           (duk_size_t) DUK_HSTRING_GET_BYTELEN(h2));
}

#if 0  /* unused */
DUK_INTERNAL duk_small_int_t duk_js_buffer_compare(duk_heap *heap, duk_hbuffer *h1, duk_hbuffer *h2) {
	/* Similar to String comparison. */

	DUK_ASSERT(h1 != NULL);
	DUK_ASSERT(h2 != NULL);
	DUK_UNREF(heap);

	return duk_js_data_compare((const duk_uint8_t *) DUK_HBUFFER_GET_DATA_PTR(heap, h1),
	                           (const duk_uint8_t *) DUK_HBUFFER_GET_DATA_PTR(heap, h2),
	                           (duk_size_t) DUK_HBUFFER_GET_SIZE(h1),
	                           (duk_size_t) DUK_HBUFFER_GET_SIZE(h2));
}

DUK_INTERNAL void duk_default_fatal_handler(duk_context *ctx, duk_errcode_t code, const char *msg) {
	DUK_UNREF(ctx);
#ifdef DUK_USE_FILE_IO
	DUK_FPRINTF(DUK_STDERR, "FATAL %ld: %s\n", (long) code, (const char *) (msg ? msg : "null"));
	DUK_FFLUSH(DUK_STDERR);
#else
	/* omit print */
#endif
	DUK_D(DUK_DPRINT("default fatal handler called, code %ld -> calling DUK_PANIC()", (long) code));
	DUK_PANIC(code, msg);
	DUK_UNREACHABLE();
}