/* Helper which can be called both directly and with duk_safe_call(). */
DUK_LOCAL duk_ret_t duk__do_compile(duk_context *ctx, void *udata) {
duk_hthread *thr = (duk_hthread *) ctx;
duk__compile_raw_args *comp_args;
duk_uint_t flags;
duk_small_uint_t comp_flags;
duk_hcompfunc *h_templ;
DUK_ASSERT_CTX_VALID(ctx);
DUK_ASSERT(udata != NULL);
/* Note: strictness is not inherited from the current Duktape/C
* context. Otherwise it would not be possible to compile
* non-strict code inside a Duktape/C activation (which is
* always strict now). See tests/api/test-eval-strictness.c
* for discussion.
*/
/* [ ... source? filename? ] (depends on flags) */
comp_args = (duk__compile_raw_args *) udata;
flags = comp_args->flags;
if (flags & DUK_COMPILE_NOFILENAME) {
/* Automatic filename: 'eval' or 'input'. */
duk_push_hstring_stridx(ctx, (flags & DUK_COMPILE_EVAL) ? DUK_STRIDX_EVAL : DUK_STRIDX_INPUT);
}
/* [ ... source? filename ] */
if (!comp_args->src_buffer) {
duk_hstring *h_sourcecode;
h_sourcecode = duk_get_hstring(ctx, -2);
if ((flags & DUK_COMPILE_NOSOURCE) || /* args incorrect */
(h_sourcecode == NULL)) { /* e.g. duk_push_string_file_raw() pushed undefined */
DUK_ERROR_TYPE(thr, DUK_STR_NO_SOURCECODE);
}
DUK_ASSERT(h_sourcecode != NULL);
comp_args->src_buffer = (const duk_uint8_t *) DUK_HSTRING_GET_DATA(h_sourcecode);
comp_args->src_length = (duk_size_t) DUK_HSTRING_GET_BYTELEN(h_sourcecode);
}
DUK_ASSERT(comp_args->src_buffer != NULL);
/* XXX: unnecessary translation of flags */
comp_flags = 0;
if (flags & DUK_COMPILE_EVAL) {
comp_flags |= DUK_JS_COMPILE_FLAG_EVAL;
}
if (flags & DUK_COMPILE_FUNCTION) {
comp_flags |= DUK_JS_COMPILE_FLAG_EVAL |
DUK_JS_COMPILE_FLAG_FUNCEXPR;
}
if (flags & DUK_COMPILE_STRICT) {
comp_flags |= DUK_JS_COMPILE_FLAG_STRICT;
}
/* [ ... source? filename ] */
duk_js_compile(thr, comp_args->src_buffer, comp_args->src_length, comp_flags);
/* [ ... source? func_template ] */
if (flags & DUK_COMPILE_NOSOURCE) {
;
} else {
duk_remove(ctx, -2);
}
/* [ ... func_template ] */
h_templ = (duk_hcompfunc *) duk_get_hobject(ctx, -1);
DUK_ASSERT(h_templ != NULL);
duk_js_push_closure(thr,
h_templ,
thr->builtins[DUK_BIDX_GLOBAL_ENV],
thr->builtins[DUK_BIDX_GLOBAL_ENV],
1 /*add_auto_proto*/);
duk_remove(ctx, -2); /* -> [ ... closure ] */
/* [ ... closure ] */
return 1;
}
/* XXX: Make this obsolete by adding a function flag for rejecting a
* non-constructor call automatically?
*/
DUK_INTERNAL void duk_require_constructor_call(duk_context *ctx) {
if (!duk_is_constructor_call(ctx)) {
DUK_ERROR_TYPE((duk_hthread *) ctx, DUK_STR_CONSTRUCT_ONLY);
}
}
DUK_INTERNAL duk_bool_t duk_js_instanceof(duk_hthread *thr, duk_tval *tv_x, duk_tval *tv_y) {
duk_context *ctx = (duk_context *) thr;
duk_hobject *func;
duk_hobject *val;
duk_hobject *proto;
duk_uint_t sanity;
/*
* Get the values onto the stack first. It would be possible to cover
* some normal cases without resorting to the value stack.
*
* The right hand side could be a light function (as they generally
* behave like objects). Light functions never have a 'prototype'
* property so E5.1 Section 15.3.5.3 step 3 always throws a TypeError.
* Using duk_require_hobject() is thus correct (except for error msg).
*/
duk_push_tval(ctx, tv_x);
duk_push_tval(ctx, tv_y);
func = duk_require_hobject(ctx, -1);
/*
* For bound objects, [[HasInstance]] just calls the target function
* [[HasInstance]]. If that is again a bound object, repeat until
* we find a non-bound Function object.
*/
/* XXX: this bound function resolution also happens elsewhere,
* move into a shared helper.
*/
sanity = DUK_HOBJECT_BOUND_CHAIN_SANITY;
do {
/* check func supports [[HasInstance]] (this is checked for every function
* in the bound chain, including the final one)
*/
if (!DUK_HOBJECT_IS_CALLABLE(func)) {
/*
* Note: of native Ecmascript objects, only Function instances
* have a [[HasInstance]] internal property. Custom objects might
* also have it, but not in current implementation.
*
* XXX: add a separate flag, DUK_HOBJECT_FLAG_ALLOW_INSTANCEOF?
*/
DUK_ERROR_TYPE(thr, "invalid instanceof rval");
}
if (!DUK_HOBJECT_HAS_BOUND(func)) {
break;
}
/* [ ... lval rval ] */
duk_get_prop_stridx(ctx, -1, DUK_STRIDX_INT_TARGET); /* -> [ ... lval rval new_rval ] */
duk_replace(ctx, -1); /* -> [ ... lval new_rval ] */
func = duk_require_hobject(ctx, -1);
/* func support for [[HasInstance]] checked in the beginning of the loop */
} while (--sanity > 0);
if (sanity == 0) {
DUK_ERROR_RANGE(thr, DUK_STR_BOUND_CHAIN_LIMIT);
}
/*
* 'func' is now a non-bound object which supports [[HasInstance]]
* (which here just means DUK_HOBJECT_FLAG_CALLABLE). Move on
* to execute E5 Section 15.3.5.3.
*/
DUK_ASSERT(!DUK_HOBJECT_HAS_BOUND(func));
DUK_ASSERT(DUK_HOBJECT_IS_CALLABLE(func));
/* [ ... lval rval(func) ] */
/* Handle lightfuncs through object coercion for now. */
/* XXX: direct implementation */
val = duk_get_hobject_or_lfunc_coerce(ctx, -2);
if (!val) {
goto pop_and_false;
}
duk_get_prop_stridx(ctx, -1, DUK_STRIDX_PROTOTYPE); /* -> [ ... lval rval rval.prototype ] */
proto = duk_require_hobject(ctx, -1);
duk_pop(ctx); /* -> [ ... lval rval ] */
DUK_ASSERT(val != NULL);
#if defined(DUK_USE_ES6_PROXY)
val = duk_hobject_resolve_proxy_target(thr, val);
DUK_ASSERT(val != NULL);
#endif
sanity = DUK_HOBJECT_PROTOTYPE_CHAIN_SANITY;
do {
/*
* Note: prototype chain is followed BEFORE first comparison. This
* means that the instanceof lval is never itself compared to the
* rval.prototype property. This is apparently intentional, see E5
* Section 15.3.5.3, step 4.a.
*
* Also note:
*
* js> (function() {}) instanceof Function
* true
* js> Function instanceof Function
* true
*
* For the latter, h_proto will be Function.prototype, which is the
* built-in Function prototype. Because Function.[[Prototype]] is
* also the built-in Function prototype, the result is true.
*/
DUK_ASSERT(val != NULL);
val = DUK_HOBJECT_GET_PROTOTYPE(thr->heap, val);
if (!val) {
goto pop_and_false;
}
DUK_ASSERT(val != NULL);
#if defined(DUK_USE_ES6_PROXY)
val = duk_hobject_resolve_proxy_target(thr, val);
#endif
if (val == proto) {
goto pop_and_true;
}
/* follow prototype chain */
} while (--sanity > 0);
if (sanity == 0) {
DUK_ERROR_RANGE(thr, DUK_STR_PROTOTYPE_CHAIN_LIMIT);
}
DUK_UNREACHABLE();
pop_and_false:
duk_pop_2(ctx);
return 0;
pop_and_true:
duk_pop_2(ctx);
return 1;
}
DUK_EXTERNAL void duk_new(duk_context *ctx, duk_idx_t nargs) {
/*
* There are two [[Construct]] operations in the specification:
*
* - E5 Section 13.2.2: for Function objects
* - E5 Section 15.3.4.5.2: for "bound" Function objects
*
* The chain of bound functions is resolved in Section 15.3.4.5.2,
* with arguments "piling up" until the [[Construct]] internal
* method is called on the final, actual Function object. Note
* that the "prototype" property is looked up *only* from the
* final object, *before* calling the constructor.
*
* Since Duktape 2.2 bound functions are represented with the
* duk_hboundfunc internal type, and bound function chains are
* collapsed when a bound function is created. As a result, the
* direct target of a duk_hboundfunc is always non-bound and the
* this/argument lists have been resolved.
*
* When constructing new Array instances, an unnecessary object is
* created and discarded now: the standard [[Construct]] creates an
* object, and calls the Array constructor. The Array constructor
* returns an Array instance, which is used as the result value for
* the "new" operation; the object created before the Array constructor
* call is discarded.
*
* This would be easy to fix, e.g. by knowing that the Array constructor
* will always create a replacement object and skip creating the fallback
* object in that case.
*
* Note: functions called via "new" need to know they are called as a
* constructor. For instance, built-in constructors behave differently
* depending on how they are called.
*/
/* XXX: merge this with duk_js_call.c, as this function implements
* core semantics (or perhaps merge the two files altogether).
*/
duk_hthread *thr = (duk_hthread *) ctx;
duk_hobject *proto;
duk_hobject *cons;
duk_hobject *fallback;
duk_idx_t idx_cons;
duk_small_uint_t call_flags;
DUK_ASSERT_CTX_VALID(ctx);
/* [... constructor arg1 ... argN] */
idx_cons = duk_require_normalize_index(ctx, -nargs - 1);
DUK_DDD(DUK_DDDPRINT("top=%ld, nargs=%ld, idx_cons=%ld",
(long) duk_get_top(ctx), (long) nargs, (long) idx_cons));
/* XXX: code duplication */
/*
* Figure out the final, non-bound constructor, to get "prototype"
* property.
*/
duk_dup(ctx, idx_cons);
duk_resolve_nonbound_function(ctx);
duk_require_callable(ctx, -1);
cons = duk_get_hobject(ctx, -1);
/* Result is a lightfunc or a callable actual function. */
DUK_ASSERT(cons == NULL || DUK_HOBJECT_IS_CALLABLE(cons));
if (cons != NULL && !DUK_HOBJECT_HAS_CONSTRUCTABLE(cons)) {
/* Check constructability from the final, non-bound object.
* The constructable flag is 1:1 for the bound function and
* its target so this should be sufficient. Lightfuncs are
* always constructable.
*/
goto not_constructable;
}
DUK_ASSERT(duk_is_callable(ctx, -1));
DUK_ASSERT(duk_is_lightfunc(ctx, -1) ||
(duk_get_hobject(ctx, -1) != NULL && !DUK_HOBJECT_HAS_BOUNDFUNC(duk_get_hobject(ctx, -1))));
/* [... constructor arg1 ... argN final_cons] */
/*
* Create "fallback" object to be used as the object instance,
* unless the constructor returns a replacement value.
* Its internal prototype needs to be set based on "prototype"
* property of the constructor.
*/
duk_push_object(ctx); /* class Object, extensible */
/* [... constructor arg1 ... argN final_cons fallback] */
duk_get_prop_stridx_short(ctx, -2, DUK_STRIDX_PROTOTYPE);
proto = duk_get_hobject(ctx, -1);
if (!proto) {
DUK_DDD(DUK_DDDPRINT("constructor has no 'prototype' property, or value not an object "
"-> leave standard Object prototype as fallback prototype"));
} else {
DUK_DDD(DUK_DDDPRINT("constructor has 'prototype' property with object value "
"-> set fallback prototype to that value: %!iO", (duk_heaphdr *) proto));
fallback = duk_known_hobject(ctx, -2);
DUK_ASSERT(fallback != NULL);
DUK_HOBJECT_SET_PROTOTYPE_UPDREF(thr, fallback, proto);
}
duk_pop(ctx);
#if 0 /* XXX: smaller alternative */
if (duk_is_object(ctx, -1)) {
DUK_DDD(DUK_DDDPRINT("constructor has 'prototype' property with object value "
"-> set fallback prototype to that value: %!iT", duk_get_tval(ctx, -1)));
duk_set_prototype(ctx, -2);
} else {
DUK_DDD(DUK_DDDPRINT("constructor has no 'prototype' property, or value not an object "
"-> leave standard Object prototype as fallback prototype"));
duk_pop(ctx);
}
#endif
/* [... constructor arg1 ... argN final_cons fallback] */
/*
* Manipulate value stack for the call.
*/
duk_dup_top(ctx);
duk_insert(ctx, idx_cons + 1); /* use fallback as 'this' value */
duk_insert(ctx, idx_cons); /* also stash it before constructor,
* in case we need it (as the fallback value)
*/
duk_pop(ctx); /* pop final_cons */
/* [... fallback constructor fallback(this) arg1 ... argN];
* Note: idx_cons points to first 'fallback', not 'constructor'.
*/
DUK_DDD(DUK_DDDPRINT("before call, idx_cons+1 (constructor) -> %!T, idx_cons+2 (fallback/this) -> %!T, "
"nargs=%ld, top=%ld",
(duk_tval *) duk_get_tval(ctx, idx_cons + 1),
(duk_tval *) duk_get_tval(ctx, idx_cons + 2),
(long) nargs,
(long) duk_get_top(ctx)));
/*
* Call the constructor function (called in "constructor mode").
*/
call_flags = DUK_CALL_FLAG_CONSTRUCTOR_CALL; /* not protected, respect reclimit, is a constructor call */
duk_handle_call_unprotected(thr, /* thread */
nargs, /* num_stack_args */
call_flags); /* call_flags */
/* [... fallback retval] */
DUK_DDD(DUK_DDDPRINT("constructor call finished, fallback=%!iT, retval=%!iT",
(duk_tval *) duk_get_tval(ctx, -2),
(duk_tval *) duk_get_tval(ctx, -1)));
/*
* Determine whether to use the constructor return value as the created
* object instance or not.
*/
if (duk_check_type_mask(ctx, -1, DUK_TYPE_MASK_OBJECT |
DUK_TYPE_MASK_BUFFER |
DUK_TYPE_MASK_LIGHTFUNC)) {
duk_remove_m2(ctx);
} else {
duk_pop(ctx);
}
/*
* Augment created errors upon creation (not when they are thrown or
* rethrown). __FILE__ and __LINE__ are not desirable here; the call
* stack reflects the caller which is correct.
*/
#if defined(DUK_USE_AUGMENT_ERROR_CREATE)
duk_hthread_sync_currpc(thr);
duk_err_augment_error_create(thr, thr, NULL, 0, 1 /*noblame_fileline*/);
#endif
/* [... retval] */
return;
not_constructable:
#if defined(DUK_USE_VERBOSE_ERRORS)
#if defined(DUK_USE_PARANOID_ERRORS)
DUK_ERROR_FMT1(thr, DUK_ERR_TYPE_ERROR, "%s not constructable", duk_get_type_name(ctx, -1));
#else
DUK_ERROR_FMT1(thr, DUK_ERR_TYPE_ERROR, "%s not constructable", duk_push_string_readable(ctx, -1));
#endif
#else
DUK_ERROR_TYPE(thr, "not constructable");
#endif
}
