DUK_EXTERNAL duk_int_t duk_get_magic(duk_context *ctx, duk_idx_t idx) {
duk_hthread *thr = (duk_hthread *) ctx;
duk_tval *tv;
duk_hobject *h;
DUK_ASSERT_CTX_VALID(ctx);
tv = duk_require_tval(ctx, idx);
if (DUK_TVAL_IS_OBJECT(tv)) {
h = DUK_TVAL_GET_OBJECT(tv);
DUK_ASSERT(h != NULL);
if (!DUK_HOBJECT_HAS_NATFUNC(h)) {
goto type_error;
}
return (duk_int_t) ((duk_hnatfunc *) h)->magic;
} else if (DUK_TVAL_IS_LIGHTFUNC(tv)) {
duk_small_uint_t lf_flags = DUK_TVAL_GET_LIGHTFUNC_FLAGS(tv);
return (duk_int_t) DUK_LFUNC_FLAGS_GET_MAGIC(lf_flags);
}
/* fall through */
type_error:
DUK_ERROR_TYPE(thr, DUK_STR_UNEXPECTED_TYPE);
return 0;
}
DUK_INTERNAL void duk_resolve_nonbound_function(duk_context *ctx) {
duk_uint_t sanity;
duk_tval *tv;
sanity = DUK_HOBJECT_BOUND_CHAIN_SANITY;
do {
tv = DUK_GET_TVAL_NEGIDX(ctx, -1);
if (DUK_TVAL_IS_LIGHTFUNC(tv)) {
/* Lightweight function: never bound, so terminate. */
break;
} else if (DUK_TVAL_IS_OBJECT(tv)) {
duk_hobject *func;
func = DUK_TVAL_GET_OBJECT(tv);
DUK_ASSERT(func != NULL);
if (!DUK_HOBJECT_IS_CALLABLE(func) || !DUK_HOBJECT_HAS_BOUNDFUNC(func)) {
break;
}
duk_get_prop_stridx_short(ctx, -1, DUK_STRIDX_INT_TARGET);
duk_replace(ctx, -2);
} else {
break;
}
} while (--sanity > 0);
}
DUK_INTERNAL duk_ret_t duk_bi_function_prototype_to_string(duk_context *ctx) {
duk_tval *tv;
/*
* E5 Section 15.3.4.2 places few requirements on the output of
* this function:
*
* - The result is an implementation dependent representation
* of the function; in particular
*
* - The result must follow the syntax of a FunctionDeclaration.
* In particular, the function must have a name (even in the
* case of an anonymous function or a function with an empty
* name).
*
* - Note in particular that the output does NOT need to compile
* into anything useful.
*/
/* XXX: faster internal way to get this */
duk_push_this(ctx);
tv = duk_get_tval(ctx, -1);
DUK_ASSERT(tv != NULL);
if (DUK_TVAL_IS_OBJECT(tv)) {
duk_hobject *obj = DUK_TVAL_GET_OBJECT(tv);
const char *func_name;
/* Function name: missing/undefined is mapped to empty string,
* otherwise coerce to string.
*/
/* XXX: currently no handling for non-allowed identifier characters,
* e.g. a '{' in the function name.
*/
duk_get_prop_stridx(ctx, -1, DUK_STRIDX_NAME);
if (duk_is_undefined(ctx, -1)) {
func_name = "";
} else {
func_name = duk_to_string(ctx, -1);
DUK_ASSERT(func_name != NULL);
}
/* Indicate function type in the function body using a dummy
* directive.
*/
if (DUK_HOBJECT_HAS_COMPILEDFUNCTION(obj)) {
duk_push_sprintf(ctx, "function %s() {\"ecmascript\"}", (const char *) func_name);
} else if (DUK_HOBJECT_HAS_NATIVEFUNCTION(obj)) {
duk_push_sprintf(ctx, "function %s() {\"native\"}", (const char *) func_name);
} else if (DUK_HOBJECT_HAS_BOUND(obj)) {
duk_push_sprintf(ctx, "function %s() {\"bound\"}", (const char *) func_name);
} else {
goto type_error;
}
} else if (DUK_TVAL_IS_LIGHTFUNC(tv)) {
duk_push_lightfunc_tostring(ctx, tv);
} else {
goto type_error;
}
return 1;
type_error:
return DUK_RET_TYPE_ERROR;
}
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.
*
* Currently we follow the bound function chain here to get the
* "prototype" property value from the final, non-bound function.
* However, we let duk_handle_call() handle the argument "piling"
* when the constructor is called. The bound function chain is
* thus now processed twice.
*
* 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);
for (;;) {
duk_tval *tv;
tv = DUK_GET_TVAL_NEGIDX(ctx, -1);
DUK_ASSERT(tv != NULL);
if (DUK_TVAL_IS_OBJECT(tv)) {
cons = DUK_TVAL_GET_OBJECT(tv);
DUK_ASSERT(cons != NULL);
if (!DUK_HOBJECT_IS_CALLABLE(cons) || !DUK_HOBJECT_HAS_CONSTRUCTABLE(cons)) {
/* Checking callability of the immediate target
* is important, same for constructability.
* Checking it for functions down the bound
* function chain is not strictly necessary
* because .bind() should normally reject them.
* But it's good to check anyway because it's
* technically possible to edit the bound function
* chain via internal keys.
*/
goto not_constructable;
}
if (!DUK_HOBJECT_HAS_BOUNDFUNC(cons)) {
break;
}
} else if (DUK_TVAL_IS_LIGHTFUNC(tv)) {
/* Lightfuncs cannot be bound. */
break;
} else {
/* Anything else is not constructable. */
goto not_constructable;
}
duk_get_prop_stridx_short(ctx, -1, DUK_STRIDX_INT_TARGET); /* -> [... cons target] */
duk_remove_m2(ctx); /* -> [... target] */
}
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_get_hobject(ctx, -2);
DUK_ASSERT(fallback != NULL);
DUK_HOBJECT_SET_PROTOTYPE_UPDREF(thr, fallback, proto);
}
duk_pop(ctx);
/* [... constructor arg1 ... argN final_cons fallback] */
/*
* Manipulate callstack 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
}
DUK_LOCAL void duk__add_traceback(duk_hthread *thr, duk_hthread *thr_callstack, const char *c_filename, duk_int_t c_line, duk_bool_t noblame_fileline) {
duk_context *ctx = (duk_context *) thr;
duk_small_uint_t depth;
duk_int_t i, i_min;
duk_int_t arr_size;
duk_harray *a;
duk_tval *tv;
duk_hstring *s;
duk_uint32_t u32;
duk_double_t d;
DUK_ASSERT(thr != NULL);
DUK_ASSERT(thr_callstack != NULL);
DUK_ASSERT(ctx != NULL);
/* [ ... error ] */
/*
* The traceback format is pretty arcane in an attempt to keep it compact
* and cheap to create. It may change arbitrarily from version to version.
* It should be decoded/accessed through version specific accessors only.
*
* See doc/error-objects.rst.
*/
DUK_DDD(DUK_DDDPRINT("adding traceback to object: %!T",
(duk_tval *) duk_get_tval(ctx, -1)));
/* Preallocate array to correct size, so that we can just write out
* the _Tracedata values into the array part.
*/
depth = DUK_USE_TRACEBACK_DEPTH;
arr_size = (duk_int_t) (thr_callstack->callstack_top <= depth ? thr_callstack->callstack_top : depth) * 2;
if (thr->compile_ctx != NULL && thr->compile_ctx->h_filename != NULL) {
arr_size += 2;
}
if (c_filename) {
/* We need the C filename to be interned before getting the
* array part pointer to avoid any GC interference while the
* array part is populated.
*/
duk_push_string(ctx, c_filename);
arr_size += 2;
}
DUK_D(DUK_DPRINT("preallocated _Tracedata to %ld items", (long) arr_size));
a = duk_push_harray_with_size(ctx, (duk_uint32_t) arr_size); /* XXX: call which returns array part pointer directly */
DUK_ASSERT(a != NULL);
tv = DUK_HOBJECT_A_GET_BASE(thr->heap, (duk_hobject *) a);
DUK_ASSERT(tv != NULL || arr_size == 0);
/* Compiler SyntaxErrors (and other errors) come first, and are
* blamed by default (not flagged "noblame").
*/
if (thr->compile_ctx != NULL && thr->compile_ctx->h_filename != NULL) {
s = thr->compile_ctx->h_filename;
DUK_TVAL_SET_STRING(tv, s);
DUK_HSTRING_INCREF(thr, s);
tv++;
u32 = (duk_uint32_t) thr->compile_ctx->curr_token.start_line; /* (flags<<32) + (line), flags = 0 */
DUK_TVAL_SET_U32(tv, u32);
tv++;
}
/* Filename/line from C macros (__FILE__, __LINE__) are added as an
* entry with a special format: (string, number). The number contains
* the line and flags.
*/
/* [ ... error c_filename? arr ] */
if (c_filename) {
DUK_ASSERT(DUK_TVAL_IS_STRING(thr->valstack_top - 2));
s = DUK_TVAL_GET_STRING(thr->valstack_top - 2); /* interned c_filename */
DUK_ASSERT(s != NULL);
DUK_TVAL_SET_STRING(tv, s);
DUK_HSTRING_INCREF(thr, s);
tv++;
d = (noblame_fileline ? ((duk_double_t) DUK_TB_FLAG_NOBLAME_FILELINE) * DUK_DOUBLE_2TO32 : 0.0) +
(duk_double_t) c_line;
DUK_TVAL_SET_DOUBLE(tv, d);
tv++;
}
/* traceback depth doesn't take into account the filename/line
* special handling above (intentional)
*/
depth = DUK_USE_TRACEBACK_DEPTH;
i_min = (thr_callstack->callstack_top > (duk_size_t) depth ? (duk_int_t) (thr_callstack->callstack_top - depth) : 0);
DUK_ASSERT(i_min >= 0);
/* [ ... error c_filename? arr ] */
DUK_ASSERT(thr_callstack->callstack_top <= DUK_INT_MAX); /* callstack limits */
for (i = (duk_int_t) (thr_callstack->callstack_top - 1); i >= i_min; i--) {
duk_uint32_t pc;
duk_tval *tv_src;
/*
* Note: each API operation potentially resizes the callstack,
* so be careful to re-lookup after every operation. Currently
* these is no issue because we don't store a temporary 'act'
* pointer at all. (This would be a non-issue if we operated
* directly on the array part.)
*/
/* [... arr] */
DUK_ASSERT_DISABLE(thr_callstack->callstack[i].pc >= 0); /* unsigned */
/* Add function object. */
tv_src = &(thr_callstack->callstack + i)->tv_func; /* object (function) or lightfunc */
DUK_ASSERT(DUK_TVAL_IS_OBJECT(tv_src) || DUK_TVAL_IS_LIGHTFUNC(tv_src));
DUK_TVAL_SET_TVAL(tv, tv_src);
DUK_TVAL_INCREF(thr, tv);
tv++;
/* Add a number containing: pc, activation flags.
*
* PC points to next instruction, find offending PC. Note that
* PC == 0 for native code.
*/
pc = duk_hthread_get_act_prev_pc(thr_callstack, thr_callstack->callstack + i);
DUK_ASSERT_DISABLE(pc >= 0); /* unsigned */
DUK_ASSERT((duk_double_t) pc < DUK_DOUBLE_2TO32); /* assume PC is at most 32 bits and non-negative */
d = ((duk_double_t) thr_callstack->callstack[i].flags) * DUK_DOUBLE_2TO32 + (duk_double_t) pc;
DUK_TVAL_SET_DOUBLE(tv, d);
tv++;
}
DUK_ASSERT((duk_uint32_t) (tv - DUK_HOBJECT_A_GET_BASE(thr->heap, (duk_hobject *) a)) == a->length);
DUK_ASSERT(a->length == (duk_uint32_t) arr_size);
/* [ ... error c_filename? arr ] */
if (c_filename) {
duk_remove(ctx, -2);
}
/* [ ... error arr ] */
duk_xdef_prop_stridx_wec(ctx, -2, DUK_STRIDX_INT_TRACEDATA); /* -> [ ... error ] */
}
