Esempio n. 1
0
duk_heap *duk_heap_alloc(duk_alloc_function alloc_func,
                         duk_realloc_function realloc_func,
                         duk_free_function free_func,
                         void *alloc_udata,
                         duk_fatal_function fatal_func) {
	duk_heap *res = NULL;

	DUK_D(DUK_DPRINT("allocate heap"));

	/* Debug dump type sizes */
#ifdef DUK_USE_DEBUG
	duk__dump_type_sizes();
#endif

	/* If selftests enabled, run them as early as possible. */
#ifdef DUK_USE_SELF_TESTS
	DUK_D(DUK_DPRINT("running self tests"));
	duk_selftest_run_tests();
	DUK_D(DUK_DPRINT("self tests passed"));
#endif

#ifdef DUK_USE_COMPUTED_NAN
	do {
		/* Workaround for some exotic platforms where NAN is missing
		 * and the expression (0.0 / 0.0) does NOT result in a NaN.
		 * Such platforms use the global 'duk_computed_nan' which must
		 * be initialized at runtime.  Use 'volatile' to ensure that
		 * the compiler will actually do the computation and not try
		 * to do constant folding which might result in the original
		 * problem.
		 */
		volatile double dbl1 = 0.0;
		volatile double dbl2 = 0.0;
		duk_computed_nan = dbl1 / dbl2;
	} while (0);
#endif

#ifdef DUK_USE_COMPUTED_INFINITY
	do {
		/* Similar workaround for INFINITY. */
		volatile double dbl1 = 1.0;
		volatile double dbl2 = 0.0;
		duk_computed_infinity = dbl1 / dbl2;
	} while (0);
#endif

	/* use a raw call, all macros expect the heap to be initialized */
	res = (duk_heap *) alloc_func(alloc_udata, sizeof(duk_heap));
	if (!res) {
		goto error;
	}

	/* zero everything */
	DUK_MEMZERO(res, sizeof(*res));

	/* explicit NULL inits */
#ifdef DUK_USE_EXPLICIT_NULL_INIT
	res->alloc_udata = NULL;
	res->heap_allocated = NULL;
#ifdef DUK_USE_REFERENCE_COUNTING
	res->refzero_list = NULL;
	res->refzero_list_tail = NULL;
#endif
#ifdef DUK_USE_MARK_AND_SWEEP
	res->finalize_list = NULL;
#endif
	res->heap_thread = NULL;
	res->curr_thread = NULL;
	res->heap_object = NULL;
	res->log_buffer = NULL;
	res->st = NULL;
	{
		int i;
	        for (i = 0; i < DUK_HEAP_NUM_STRINGS; i++) {
        	        res->strs[i] = NULL;
	        }
	}
#endif

	/* initialize the structure, roughly in order */
	res->alloc_func = alloc_func;
	res->realloc_func = realloc_func;
	res->free_func = free_func;
	res->alloc_udata = alloc_udata;
	res->fatal_func = fatal_func;

	/* res->mark_and_sweep_trigger_counter == 0 -> now causes immediate GC; which is OK */

	res->call_recursion_depth = 0;
	res->call_recursion_limit = DUK_HEAP_DEFAULT_CALL_RECURSION_LIMIT;

	/* FIXME: use the pointer as a seed for now: mix in time at least */

	/* cast through C99 intptr_t to avoid GCC warning:
	 *
	 *   warning: cast from pointer to integer of different size [-Wpointer-to-int-cast]
	 */
	res->hash_seed = (duk_uint32_t) (duk_intptr_t) res;
	res->rnd_state = (duk_uint32_t) (duk_intptr_t) res;

#ifdef DUK_USE_INTERRUPT_COUNTER
	/* zero value causes an interrupt before executing first instruction */
	DUK_ASSERT(res->interrupt_counter == 0);
	DUK_ASSERT(res->interrupt_init == 0);
#endif

#ifdef DUK_USE_EXPLICIT_NULL_INIT
	res->lj.jmpbuf_ptr = NULL;
#endif
	DUK_ASSERT(res->lj.type == DUK_LJ_TYPE_UNKNOWN);  /* zero */

	DUK_TVAL_SET_UNDEFINED_UNUSED(&res->lj.value1);
	DUK_TVAL_SET_UNDEFINED_UNUSED(&res->lj.value2);

#if (DUK_STRTAB_INITIAL_SIZE < DUK_UTIL_MIN_HASH_PRIME)
#error initial heap stringtable size is defined incorrectly
#endif

	res->st = (duk_hstring **) alloc_func(alloc_udata, sizeof(duk_hstring *) * DUK_STRTAB_INITIAL_SIZE);
	if (!res->st) {
		goto error;
	}
	res->st_size = DUK_STRTAB_INITIAL_SIZE;
#ifdef DUK_USE_EXPLICIT_NULL_INIT
	{
		duk_uint_fast32_t i;
	        for (i = 0; i < res->st_size; i++) {
        	        res->st[i] = NULL;
	        }
	}
#else
	DUK_MEMZERO(res->st, sizeof(duk_hstring *) * DUK_STRTAB_INITIAL_SIZE);
#endif

	/* strcache init */
#ifdef DUK_USE_EXPLICIT_NULL_INIT
	{
		int i;
		for (i = 0; i < DUK_HEAP_STRCACHE_SIZE; i++) {
			res->strcache[i].h = NULL;
		}
	}
#endif

	/* FIXME: error handling is incomplete.  It would be cleanest if
	 * there was a setjmp catchpoint, so that all init code could
	 * freely throw errors.  If that were the case, the return code
	 * passing here could be removed.
	 */

	/* built-in strings */
	DUK_DD(DUK_DDPRINT("HEAP: INIT STRINGS"));
	if (!duk__init_heap_strings(res)) {
		goto error;
	}

	/* heap thread */
	DUK_DD(DUK_DDPRINT("HEAP: INIT HEAP THREAD"));
	if (!duk__init_heap_thread(res)) {
		goto error;
	}

	/* heap object */
	DUK_DD(DUK_DDPRINT("HEAP: INIT HEAP OBJECT"));
	DUK_ASSERT(res->heap_thread != NULL);
	res->heap_object = duk_hobject_alloc(res, DUK_HOBJECT_FLAG_EXTENSIBLE |
	                                          DUK_HOBJECT_CLASS_AS_FLAGS(DUK_HOBJECT_CLASS_OBJECT));
	if (!res->heap_object) {
		goto error;
	}
	DUK_HOBJECT_INCREF(res->heap_thread, res->heap_object);

	/* log buffer */
	DUK_DD(DUK_DDPRINT("HEAP: INIT LOG BUFFER"));
	res->log_buffer = (duk_hbuffer_dynamic *) duk_hbuffer_alloc(res,
	                                                            DUK_BI_LOGGER_SHORT_MSG_LIMIT,
	                                                            1 /*dynamic*/);
	if (!res->log_buffer) {
		goto error;
	}
	DUK_HBUFFER_INCREF(res->heap_thread, res->log_buffer);

	DUK_D(DUK_DPRINT("allocated heap: %p", res));
	return res;

 error:
	DUK_D(DUK_DPRINT("heap allocation failed"));

	if (res) {
		/* assumes that allocated pointers and alloc funcs are valid
		 * if res exists
		 */
		DUK_ASSERT(res->alloc_func != NULL);
		DUK_ASSERT(res->realloc_func != NULL);
		DUK_ASSERT(res->free_func != NULL);
		duk_heap_free(res);
	}
	return NULL;
}
Esempio n. 2
0
static duk_uint8_t *duk__load_func(duk_context *ctx, duk_uint8_t *p, duk_uint8_t *p_end) {
	duk_hthread *thr;
	duk_hcompiledfunction *h_fun;
	duk_hbuffer *h_data;
	duk_size_t data_size;
	duk_uint32_t count_instr, count_const, count_funcs;
	duk_uint32_t n;
	duk_uint32_t tmp32;
	duk_small_uint_t const_type;
	duk_uint8_t *fun_data;
	duk_uint8_t *q;
	duk_idx_t idx_base;
	duk_tval *tv;
	duk_uarridx_t arr_idx;

	/* XXX: There's some overlap with duk_js_closure() here, but
	 * seems difficult to share code.  Ensure that the final function
	 * looks the same as created by duk_js_closure().
	 */

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

	DUK_DD(DUK_DDPRINT("loading function, p=%p, p_end=%p", (void *) p, (void *) p_end));

	DUK__ASSERT_LEFT(3 * 4);
	count_instr = DUK_RAW_READ_U32_BE(p);
	count_const = DUK_RAW_READ_U32_BE(p);
	count_funcs = DUK_RAW_READ_U32_BE(p);

	data_size = sizeof(duk_tval) * count_const +
	            sizeof(duk_hobject *) * count_funcs +
	            sizeof(duk_instr_t) * count_instr;

	DUK_DD(DUK_DDPRINT("instr=%ld, const=%ld, funcs=%ld, data_size=%ld",
	                   (long) count_instr, (long) count_const,
	                   (long) count_const, (long) data_size));

	/* Value stack is used to ensure reachability of constants and
	 * inner functions being loaded.  Require enough space to handle
	 * large functions correctly.
	 */
	duk_require_stack(ctx, 2 + count_const + count_funcs);
	idx_base = duk_get_top(ctx);

	/* Push function object, init flags etc.  This must match
	 * duk_js_push_closure() quite carefully.
	 */
	duk_push_compiledfunction(ctx);
	h_fun = duk_get_hcompiledfunction(ctx, -1);
	DUK_ASSERT(h_fun != NULL);
	DUK_ASSERT(DUK_HOBJECT_IS_COMPILEDFUNCTION((duk_hobject *) h_fun));
	DUK_ASSERT(DUK_HCOMPILEDFUNCTION_GET_DATA(thr->heap, h_fun) == NULL);
	DUK_ASSERT(DUK_HCOMPILEDFUNCTION_GET_FUNCS(thr->heap, h_fun) == NULL);
	DUK_ASSERT(DUK_HCOMPILEDFUNCTION_GET_BYTECODE(thr->heap, h_fun) == NULL);

	h_fun->nregs = DUK_RAW_READ_U16_BE(p);
	h_fun->nargs = DUK_RAW_READ_U16_BE(p);
#if defined(DUK_USE_DEBUGGER_SUPPORT)
	h_fun->start_line = DUK_RAW_READ_U32_BE(p);
	h_fun->end_line = DUK_RAW_READ_U32_BE(p);
#else
	p += 8;  /* skip line info */
#endif

	/* duk_hcompiledfunction flags; quite version specific */
	tmp32 = DUK_RAW_READ_U32_BE(p);
	DUK_HEAPHDR_SET_FLAGS((duk_heaphdr *) h_fun, tmp32);

	/* standard prototype */
	DUK_HOBJECT_SET_PROTOTYPE_UPDREF(thr, &h_fun->obj, thr->builtins[DUK_BIDX_FUNCTION_PROTOTYPE]);

	/* assert just a few critical flags */
	DUK_ASSERT(DUK_HEAPHDR_GET_TYPE((duk_heaphdr *) h_fun) == DUK_HTYPE_OBJECT);
	DUK_ASSERT(!DUK_HOBJECT_HAS_BOUND(&h_fun->obj));
	DUK_ASSERT(DUK_HOBJECT_HAS_COMPILEDFUNCTION(&h_fun->obj));
	DUK_ASSERT(!DUK_HOBJECT_HAS_NATIVEFUNCTION(&h_fun->obj));
	DUK_ASSERT(!DUK_HOBJECT_HAS_THREAD(&h_fun->obj));
	DUK_ASSERT(!DUK_HOBJECT_HAS_EXOTIC_ARRAY(&h_fun->obj));
	DUK_ASSERT(!DUK_HOBJECT_HAS_EXOTIC_STRINGOBJ(&h_fun->obj));
	DUK_ASSERT(!DUK_HOBJECT_HAS_EXOTIC_ARGUMENTS(&h_fun->obj));

	/* Create function 'data' buffer but don't attach it yet. */
	fun_data = (duk_uint8_t *) duk_push_fixed_buffer(ctx, data_size);
	DUK_ASSERT(fun_data != NULL);

	/* Load bytecode instructions. */
	DUK_ASSERT(sizeof(duk_instr_t) == 4);
	DUK__ASSERT_LEFT(count_instr * sizeof(duk_instr_t));
#if defined(DUK_USE_INTEGER_BE)
	q = fun_data + sizeof(duk_tval) * count_const + sizeof(duk_hobject *) * count_funcs;
	DUK_MEMCPY((void *) q,
	           (const void *) p,
	           sizeof(duk_instr_t) * count_instr);
	p += sizeof(duk_instr_t) * count_instr;
#else
	q = fun_data + sizeof(duk_tval) * count_const + sizeof(duk_hobject *) * count_funcs;
	for (n = count_instr; n > 0; n--) {
		*((duk_instr_t *) (void *) q) = DUK_RAW_READ_U32_BE(p);
		q += sizeof(duk_instr_t);
	}
#endif

	/* Load constants onto value stack but don't yet copy to buffer. */
	for (n = count_const; n > 0; n--) {
		DUK__ASSERT_LEFT(1);
		const_type = DUK_RAW_READ_U8(p);
		switch (const_type) {
		case DUK__SER_STRING: {
			p = duk__load_string_raw(ctx, p);
			break;
		}
		case DUK__SER_NUMBER: {
			/* Important to do a fastint check so that constants are
			 * properly read back as fastints.
			 */
			duk_tval tv_tmp;
			duk_double_t val;
			DUK__ASSERT_LEFT(8);
			val = DUK_RAW_READ_DOUBLE_BE(p);
			DUK_TVAL_SET_NUMBER_CHKFAST(&tv_tmp, val);
			duk_push_tval(ctx, &tv_tmp);
			break;
		}
		default: {
			goto format_error;
		}
		}
	}

	/* Load inner functions to value stack, but don't yet copy to buffer. */
	for (n = count_funcs; n > 0; n--) {
		p = duk__load_func(ctx, p, p_end);
		if (p == NULL) {
			goto format_error;
		}
	}

	/* With constants and inner functions on value stack, we can now
	 * atomically finish the function 'data' buffer, bump refcounts,
	 * etc.
	 *
	 * Here we take advantage of the value stack being just a duk_tval
	 * array: we can just memcpy() the constants as long as we incref
	 * them afterwards.
	 */

	h_data = (duk_hbuffer *) duk_get_hbuffer(ctx, idx_base + 1);
	DUK_ASSERT(h_data != NULL);
	DUK_ASSERT(!DUK_HBUFFER_HAS_DYNAMIC(h_data));
	DUK_HCOMPILEDFUNCTION_SET_DATA(thr->heap, h_fun, h_data);
	DUK_HBUFFER_INCREF(thr, h_data);

	tv = duk_get_tval(ctx, idx_base + 2);  /* may be NULL if no constants or inner funcs */
	DUK_ASSERT((count_const == 0 && count_funcs == 0) || tv != NULL);

	q = fun_data;
	if (count_const > 0) {
		/* Explicit zero size check to avoid NULL 'tv'. */
		DUK_MEMCPY((void *) q, (const void *) tv, sizeof(duk_tval) * count_const);
		for (n = count_const; n > 0; n--) {
			DUK_TVAL_INCREF_FAST(thr, (duk_tval *) (void *) q);  /* no side effects */
			q += sizeof(duk_tval);
		}
		tv += count_const;
	}

	DUK_HCOMPILEDFUNCTION_SET_FUNCS(thr->heap, h_fun, (duk_hobject **) (void *) q);
	for (n = count_funcs; n > 0; n--) {
		duk_hobject *h_obj;

		DUK_ASSERT(DUK_TVAL_IS_OBJECT(tv));
		h_obj = DUK_TVAL_GET_OBJECT(tv);
		DUK_ASSERT(h_obj != NULL);
		tv++;
		DUK_HOBJECT_INCREF(thr, h_obj);

		*((duk_hobject **) (void *) q) = h_obj;
		q += sizeof(duk_hobject *);
	}

	DUK_HCOMPILEDFUNCTION_SET_BYTECODE(thr->heap, h_fun, (duk_instr_t *) (void *) q);

	/* The function object is now reachable and refcounts are fine,
	 * so we can pop off all the temporaries.
	 */
	DUK_DDD(DUK_DDDPRINT("function is reachable, reset top; func: %!iT", duk_get_tval(ctx, idx_base)));
	duk_set_top(ctx, idx_base + 1);

	/* Setup function properties. */
	tmp32 = DUK_RAW_READ_U32_BE(p);
	duk_push_u32(ctx, tmp32);
	duk_xdef_prop_stridx(ctx, -2, DUK_STRIDX_LENGTH, DUK_PROPDESC_FLAGS_NONE);

	p = duk__load_string_raw(ctx, p);
	if (DUK_HOBJECT_HAS_NAMEBINDING((duk_hobject *) h_fun)) {
		/* Original function instance/template had NAMEBINDING.
		 * Must create a lexical environment on loading to allow
		 * recursive functions like 'function foo() { foo(); }'.
		 */
		duk_hobject *proto;

		proto = thr->builtins[DUK_BIDX_GLOBAL_ENV];
		(void) duk_push_object_helper_proto(ctx,
		                                    DUK_HOBJECT_FLAG_EXTENSIBLE |
		                                    DUK_HOBJECT_CLASS_AS_FLAGS(DUK_HOBJECT_CLASS_DECENV),
		                                    proto);
		duk_dup(ctx, -2);                                 /* -> [ func funcname env funcname ] */
		duk_dup(ctx, idx_base);                           /* -> [ func funcname env funcname func ] */
		duk_xdef_prop(ctx, -3, DUK_PROPDESC_FLAGS_NONE);  /* -> [ func funcname env ] */
		duk_xdef_prop_stridx(ctx, idx_base, DUK_STRIDX_INT_LEXENV, DUK_PROPDESC_FLAGS_WC);
		/* since closure has NEWENV, never define DUK_STRIDX_INT_VARENV, as it
		 * will be ignored anyway
		 */
	}
	duk_xdef_prop_stridx(ctx, -2, DUK_STRIDX_NAME, DUK_PROPDESC_FLAGS_NONE);

	p = duk__load_string_raw(ctx, p);
	duk_xdef_prop_stridx(ctx, -2, DUK_STRIDX_FILE_NAME, DUK_PROPDESC_FLAGS_WC);

	duk_push_object(ctx);
	duk_dup(ctx, -2);
	duk_xdef_prop_stridx(ctx, -2, DUK_STRIDX_CONSTRUCTOR, DUK_PROPDESC_FLAGS_WC);  /* func.prototype.constructor = func */
	duk_compact(ctx, -1);
	duk_xdef_prop_stridx(ctx, -2, DUK_STRIDX_PROTOTYPE, DUK_PROPDESC_FLAGS_W);

	p = duk__load_buffer_raw(ctx, p);
	duk_xdef_prop_stridx(ctx, -2, DUK_STRIDX_INT_PC2LINE, DUK_PROPDESC_FLAGS_WC);

	duk_push_object(ctx);  /* _Varmap */
	for (;;) {
		/* XXX: awkward */
		p = duk__load_string_raw(ctx, p);
		if (duk_get_length(ctx, -1) == 0) {
			duk_pop(ctx);
			break;
		}
		tmp32 = DUK_RAW_READ_U32_BE(p);
		duk_push_u32(ctx, tmp32);
		duk_put_prop(ctx, -3);
	}
	duk_compact(ctx, -1);
	duk_xdef_prop_stridx(ctx, -2, DUK_STRIDX_INT_VARMAP, DUK_PROPDESC_FLAGS_NONE);

	duk_push_array(ctx);  /* _Formals */
	for (arr_idx = 0; ; arr_idx++) {
		/* XXX: awkward */
		p = duk__load_string_raw(ctx, p);
		if (duk_get_length(ctx, -1) == 0) {
			duk_pop(ctx);
			break;
		}
		duk_put_prop_index(ctx, -2, arr_idx);
	}
	duk_compact(ctx, -1);
	duk_xdef_prop_stridx(ctx, -2, DUK_STRIDX_INT_FORMALS, DUK_PROPDESC_FLAGS_NONE);

	/* Return with final function pushed on stack top. */
	DUK_DD(DUK_DDPRINT("final loaded function: %!iT", duk_get_tval(ctx, -1)));
	DUK_ASSERT_TOP(ctx, idx_base + 1);
	return p;

 format_error:
	return NULL;
}