OVMS3/OVMS.V3/components/duktape/src-separate/duk_api_call.c

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/*
* Calls.
*
* Protected variants should avoid ever throwing an error. Must be careful
* to catch errors related to value stack manipulation and property lookup,
* not just the call itself.
*
* The only exception is when arguments are insane, e.g. nargs/nrets are out
* of bounds; in such cases an error is thrown for two reasons. First, we
* can't always respect the value stack input/output guarantees in such cases
* so the caller would end up with the value stack in an unexpected state.
* Second, an attempt to create an error might itself fail (although this
* could be avoided by pushing a preallocated object/string or a primitive
* value).
*/
#include "duk_internal.h"
/*
* Helpers
*/
struct duk__pcall_prop_args {
duk_idx_t obj_idx;
duk_idx_t nargs;
duk_small_uint_t call_flags;
};
typedef struct duk__pcall_prop_args duk__pcall_prop_args;
struct duk__pcall_method_args {
duk_idx_t nargs;
duk_small_uint_t call_flags;
};
typedef struct duk__pcall_method_args duk__pcall_method_args;
struct duk__pcall_args {
duk_idx_t nargs;
duk_small_uint_t call_flags;
};
typedef struct duk__pcall_args duk__pcall_args;
/* Compute and validate idx_func for a certain 'nargs' and 'other'
* parameter count (1 or 2, depending on whether 'this' binding is
* present).
*/
DUK_LOCAL duk_idx_t duk__call_get_idx_func(duk_hthread *thr, duk_idx_t nargs, duk_idx_t other) {
duk_idx_t idx_func;
/* XXX: byte arithmetic? */
DUK_ASSERT(other >= 0);
idx_func = duk_get_top(thr) - nargs - other;
if (DUK_UNLIKELY((idx_func | nargs) < 0)) { /* idx_func < 0 || nargs < 0; OR sign bits */
DUK_ERROR_TYPE_INVALID_ARGS(thr);
DUK_WO_NORETURN(return 0;);
}
DUK_ASSERT(duk_is_valid_index(thr, idx_func));
return idx_func;
}
/* Compute idx_func, assume index will be valid. This is a valid assumption
* for protected calls: nargs < 0 is checked explicitly and duk_safe_call()
* validates the argument count.
*/
DUK_LOCAL duk_idx_t duk__call_get_idx_func_unvalidated(duk_hthread *thr, duk_idx_t nargs, duk_idx_t other) {
duk_idx_t idx_func;
/* XXX: byte arithmetic? */
DUK_ASSERT(nargs >= 0);
DUK_ASSERT(other >= 0);
idx_func = duk_get_top(thr) - nargs - other;
DUK_ASSERT(idx_func >= 0);
DUK_ASSERT(duk_is_valid_index(thr, idx_func));
return idx_func;
}
/* Prepare value stack for a method call through an object property.
* May currently throw an error e.g. when getting the property.
*/
DUK_LOCAL void duk__call_prop_prep_stack(duk_hthread *thr, duk_idx_t normalized_obj_idx, duk_idx_t nargs) {
DUK_CTX_ASSERT_VALID(thr);
DUK_ASSERT(nargs >= 0);
DUK_DDD(DUK_DDDPRINT("duk__call_prop_prep_stack, normalized_obj_idx=%ld, nargs=%ld, stacktop=%ld",
(long) normalized_obj_idx, (long) nargs, (long) duk_get_top(thr)));
/* [... key arg1 ... argN] */
/* duplicate key */
duk_dup(thr, -nargs - 1); /* Note: -nargs alone would fail for nargs == 0, this is OK */
(void) duk_get_prop(thr, normalized_obj_idx);
DUK_DDD(DUK_DDDPRINT("func: %!T", (duk_tval *) duk_get_tval(thr, -1)));
#if defined(DUK_USE_VERBOSE_ERRORS)
if (DUK_UNLIKELY(!duk_is_callable(thr, -1))) {
duk_tval *tv_base;
duk_tval *tv_key;
/* tv_targ is passed on stack top (at index -1). */
tv_base = DUK_GET_TVAL_POSIDX(thr, normalized_obj_idx);
tv_key = DUK_GET_TVAL_NEGIDX(thr, -nargs - 2);
DUK_ASSERT(tv_base >= thr->valstack_bottom && tv_base < thr->valstack_top);
DUK_ASSERT(tv_key >= thr->valstack_bottom && tv_key < thr->valstack_top);
duk_call_setup_propcall_error(thr, tv_base, tv_key);
}
#endif
/* [... key arg1 ... argN func] */
duk_replace(thr, -nargs - 2);
/* [... func arg1 ... argN] */
duk_dup(thr, normalized_obj_idx);
duk_insert(thr, -nargs - 1);
/* [... func this arg1 ... argN] */
}
DUK_EXTERNAL void duk_call(duk_hthread *thr, duk_idx_t nargs) {
duk_small_uint_t call_flags;
duk_idx_t idx_func;
DUK_ASSERT_API_ENTRY(thr);
idx_func = duk__call_get_idx_func(thr, nargs, 1);
DUK_ASSERT(duk_is_valid_index(thr, idx_func));
duk_insert_undefined(thr, idx_func + 1);
call_flags = 0; /* not protected, respect reclimit, not constructor */
duk_handle_call_unprotected(thr, idx_func, call_flags);
}
DUK_EXTERNAL void duk_call_method(duk_hthread *thr, duk_idx_t nargs) {
duk_small_uint_t call_flags;
duk_idx_t idx_func;
DUK_ASSERT_API_ENTRY(thr);
idx_func = duk__call_get_idx_func(thr, nargs, 2);
DUK_ASSERT(duk_is_valid_index(thr, idx_func));
call_flags = 0; /* not protected, respect reclimit, not constructor */
duk_handle_call_unprotected(thr, idx_func, call_flags);
}
DUK_EXTERNAL void duk_call_prop(duk_hthread *thr, duk_idx_t obj_idx, duk_idx_t nargs) {
/*
* XXX: if duk_handle_call() took values through indices, this could be
* made much more sensible. However, duk_handle_call() needs to fudge
* the 'this' and 'func' values to handle bound functions, which is now
* done "in-place", so this is not a trivial change.
*/
DUK_ASSERT_API_ENTRY(thr);
obj_idx = duk_require_normalize_index(thr, obj_idx); /* make absolute */
if (DUK_UNLIKELY(nargs < 0)) {
DUK_ERROR_TYPE_INVALID_ARGS(thr);
DUK_WO_NORETURN(return;);
}
duk__call_prop_prep_stack(thr, obj_idx, nargs);
duk_call_method(thr, nargs);
}
DUK_LOCAL duk_ret_t duk__pcall_raw(duk_hthread *thr, void *udata) {
duk__pcall_args *args;
duk_idx_t idx_func;
duk_int_t ret;
DUK_CTX_ASSERT_VALID(thr);
DUK_ASSERT(udata != NULL);
args = (duk__pcall_args *) udata;
idx_func = duk__call_get_idx_func_unvalidated(thr, args->nargs, 1);
DUK_ASSERT(duk_is_valid_index(thr, idx_func));
duk_insert_undefined(thr, idx_func + 1);
ret = duk_handle_call_unprotected(thr, idx_func, args->call_flags);
DUK_ASSERT(ret == 0);
DUK_UNREF(ret);
return 1;
}
DUK_EXTERNAL duk_int_t duk_pcall(duk_hthread *thr, duk_idx_t nargs) {
duk__pcall_args args;
DUK_ASSERT_API_ENTRY(thr);
args.nargs = nargs;
if (DUK_UNLIKELY(nargs < 0)) {
DUK_ERROR_TYPE_INVALID_ARGS(thr);
DUK_WO_NORETURN(return DUK_EXEC_ERROR;);
}
args.call_flags = 0;
return duk_safe_call(thr, duk__pcall_raw, (void *) &args /*udata*/, nargs + 1 /*nargs*/, 1 /*nrets*/);
}
DUK_LOCAL duk_ret_t duk__pcall_method_raw(duk_hthread *thr, void *udata) {
duk__pcall_method_args *args;
duk_idx_t idx_func;
duk_int_t ret;
DUK_CTX_ASSERT_VALID(thr);
DUK_ASSERT(udata != NULL);
args = (duk__pcall_method_args *) udata;
idx_func = duk__call_get_idx_func_unvalidated(thr, args->nargs, 2);
DUK_ASSERT(duk_is_valid_index(thr, idx_func));
ret = duk_handle_call_unprotected(thr, idx_func, args->call_flags);
DUK_ASSERT(ret == 0);
DUK_UNREF(ret);
return 1;
}
DUK_INTERNAL duk_int_t duk_pcall_method_flags(duk_hthread *thr, duk_idx_t nargs, duk_small_uint_t call_flags) {
duk__pcall_method_args args;
DUK_ASSERT_API_ENTRY(thr);
args.nargs = nargs;
if (DUK_UNLIKELY(nargs < 0)) {
DUK_ERROR_TYPE_INVALID_ARGS(thr);
DUK_WO_NORETURN(return DUK_EXEC_ERROR;);
}
args.call_flags = call_flags;
return duk_safe_call(thr, duk__pcall_method_raw, (void *) &args /*udata*/, nargs + 2 /*nargs*/, 1 /*nrets*/);
}
DUK_EXTERNAL duk_int_t duk_pcall_method(duk_hthread *thr, duk_idx_t nargs) {
DUK_ASSERT_API_ENTRY(thr);
return duk_pcall_method_flags(thr, nargs, 0);
}
DUK_LOCAL duk_ret_t duk__pcall_prop_raw(duk_hthread *thr, void *udata) {
duk__pcall_prop_args *args;
duk_idx_t obj_idx;
duk_int_t ret;
DUK_CTX_ASSERT_VALID(thr);
DUK_ASSERT(udata != NULL);
args = (duk__pcall_prop_args *) udata;
obj_idx = duk_require_normalize_index(thr, args->obj_idx); /* make absolute */
duk__call_prop_prep_stack(thr, obj_idx, args->nargs);
ret = duk_handle_call_unprotected_nargs(thr, args->nargs, args->call_flags);
DUK_ASSERT(ret == 0);
DUK_UNREF(ret);
return 1;
}
DUK_EXTERNAL duk_int_t duk_pcall_prop(duk_hthread *thr, duk_idx_t obj_idx, duk_idx_t nargs) {
duk__pcall_prop_args args;
DUK_ASSERT_API_ENTRY(thr);
args.obj_idx = obj_idx;
args.nargs = nargs;
if (DUK_UNLIKELY(nargs < 0)) {
DUK_ERROR_TYPE_INVALID_ARGS(thr);
DUK_WO_NORETURN(return DUK_EXEC_ERROR;);
}
args.call_flags = 0;
return duk_safe_call(thr, duk__pcall_prop_raw, (void *) &args /*udata*/, nargs + 1 /*nargs*/, 1 /*nrets*/);
}
DUK_EXTERNAL duk_int_t duk_safe_call(duk_hthread *thr, duk_safe_call_function func, void *udata, duk_idx_t nargs, duk_idx_t nrets) {
duk_int_t rc;
DUK_ASSERT_API_ENTRY(thr);
/* nargs condition; fail if: top - bottom < nargs
* <=> top < bottom + nargs
* nrets condition; fail if: end - (top - nargs) < nrets
* <=> end - top + nargs < nrets
* <=> end + nargs < top + nrets
*/
/* XXX: check for any reserve? */
if (DUK_UNLIKELY((nargs | nrets) < 0 || /* nargs < 0 || nrets < 0; OR sign bits */
thr->valstack_top < thr->valstack_bottom + nargs || /* nargs too large compared to top */
thr->valstack_end + nargs < thr->valstack_top + nrets)) { /* nrets too large compared to reserve */
DUK_D(DUK_DPRINT("not enough stack reserve for safe call or invalid arguments: "
"nargs=%ld < 0 (?), nrets=%ld < 0 (?), top=%ld < bottom=%ld + nargs=%ld (?), "
"end=%ld + nargs=%ld < top=%ld + nrets=%ld (?)",
(long) nargs,
(long) nrets,
(long) (thr->valstack_top - thr->valstack),
(long) (thr->valstack_bottom - thr->valstack),
(long) nargs,
(long) (thr->valstack_end - thr->valstack),
(long) nargs,
(long) (thr->valstack_top - thr->valstack),
(long) nrets));
DUK_ERROR_TYPE_INVALID_ARGS(thr);
DUK_WO_NORETURN(return DUK_EXEC_ERROR;);
}
rc = duk_handle_safe_call(thr, /* thread */
func, /* func */
udata, /* udata */
nargs, /* num_stack_args */
nrets); /* num_stack_res */
return rc;
}
DUK_EXTERNAL void duk_new(duk_hthread *thr, duk_idx_t nargs) {
duk_idx_t idx_func;
DUK_ASSERT_API_ENTRY(thr);
idx_func = duk__call_get_idx_func(thr, nargs, 1);
DUK_ASSERT(duk_is_valid_index(thr, idx_func));
duk_push_object(thr); /* default instance; internal proto updated by call handling */
duk_insert(thr, idx_func + 1);
duk_handle_call_unprotected(thr, idx_func, DUK_CALL_FLAG_CONSTRUCT);
}
DUK_LOCAL duk_ret_t duk__pnew_helper(duk_hthread *thr, void *udata) {
duk_idx_t nargs;
DUK_ASSERT(udata != NULL);
nargs = *((duk_idx_t *) udata);
duk_new(thr, nargs);
return 1;
}
DUK_EXTERNAL duk_int_t duk_pnew(duk_hthread *thr, duk_idx_t nargs) {
duk_int_t rc;
DUK_ASSERT_API_ENTRY(thr);
/* For now, just use duk_safe_call() to wrap duk_new(). We can't
* simply use a protected duk_handle_call() because pushing the
* default instance might throw.
*/
if (DUK_UNLIKELY(nargs < 0)) {
DUK_ERROR_TYPE_INVALID_ARGS(thr);
DUK_WO_NORETURN(return DUK_EXEC_ERROR;);
}
rc = duk_safe_call(thr, duk__pnew_helper, (void *) &nargs /*udata*/, nargs + 1 /*nargs*/, 1 /*nrets*/);
return rc;
}
DUK_EXTERNAL duk_bool_t duk_is_constructor_call(duk_hthread *thr) {
duk_activation *act;
DUK_ASSERT_API_ENTRY(thr);
act = thr->callstack_curr;
if (act != NULL) {
return ((act->flags & DUK_ACT_FLAG_CONSTRUCT) != 0 ? 1 : 0);
}
return 0;
}
DUK_EXTERNAL void duk_require_constructor_call(duk_hthread *thr) {
DUK_ASSERT_API_ENTRY(thr);
if (!duk_is_constructor_call(thr)) {
DUK_ERROR_TYPE(thr, DUK_STR_CONSTRUCT_ONLY);
DUK_WO_NORETURN(return;);
}
}
DUK_EXTERNAL duk_bool_t duk_is_strict_call(duk_hthread *thr) {
duk_activation *act;
/* For user code this could just return 1 (strict) always
* because all Duktape/C functions are considered strict,
* and strict is also the default when nothing is running.
* However, Duktape may call this function internally when
* the current activation is an ECMAScript function, so
* this cannot be replaced by a 'return 1' without fixing
* the internal call sites.
*/
DUK_ASSERT_API_ENTRY(thr);
act = thr->callstack_curr;
if (act != NULL) {
return ((act->flags & DUK_ACT_FLAG_STRICT) != 0 ? 1 : 0);
} else {
/* Strict by default. */
return 1;
}
}
/*
* Duktape/C function magic
*/
DUK_EXTERNAL duk_int_t duk_get_current_magic(duk_hthread *thr) {
duk_activation *act;
duk_hobject *func;
DUK_ASSERT_API_ENTRY(thr);
act = thr->callstack_curr;
if (act) {
func = DUK_ACT_GET_FUNC(act);
if (!func) {
duk_tval *tv = &act->tv_func;
duk_small_uint_t lf_flags;
lf_flags = DUK_TVAL_GET_LIGHTFUNC_FLAGS(tv);
return (duk_int_t) DUK_LFUNC_FLAGS_GET_MAGIC(lf_flags);
}
DUK_ASSERT(func != NULL);
if (DUK_HOBJECT_IS_NATFUNC(func)) {
duk_hnatfunc *nf = (duk_hnatfunc *) func;
return (duk_int_t) nf->magic;
}
}
return 0;
}
DUK_EXTERNAL duk_int_t duk_get_magic(duk_hthread *thr, duk_idx_t idx) {
duk_tval *tv;
duk_hobject *h;
DUK_ASSERT_API_ENTRY(thr);
tv = duk_require_tval(thr, 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);
DUK_WO_NORETURN(return 0;);
}
DUK_EXTERNAL void duk_set_magic(duk_hthread *thr, duk_idx_t idx, duk_int_t magic) {
duk_hnatfunc *nf;
DUK_ASSERT_API_ENTRY(thr);
nf = duk_require_hnatfunc(thr, idx);
DUK_ASSERT(nf != NULL);
nf->magic = (duk_int16_t) magic;
}
/*
* Misc helpers
*/
/* Resolve a bound function on value stack top to a non-bound target
* (leave other values as is).
*/
DUK_INTERNAL void duk_resolve_nonbound_function(duk_hthread *thr) {
duk_tval *tv;
DUK_HTHREAD_ASSERT_VALID(thr);
tv = DUK_GET_TVAL_NEGIDX(thr, -1);
if (DUK_TVAL_IS_OBJECT(tv)) {
duk_hobject *h;
h = DUK_TVAL_GET_OBJECT(tv);
DUK_ASSERT(h != NULL);
if (DUK_HOBJECT_HAS_BOUNDFUNC(h)) {
duk_push_tval(thr, &((duk_hboundfunc *) (void *) h)->target);
duk_replace(thr, -2);
#if 0
DUK_TVAL_SET_TVAL(tv, &((duk_hboundfunc *) h)->target);
DUK_TVAL_INCREF(thr, tv);
DUK_HOBJECT_DECREF_NORZ(thr, h);
#endif
/* Rely on Function.prototype.bind() on never creating a bound
* function whose target is not proper. This is now safe
* because the target is not even an internal property but a
* struct member.
*/
DUK_ASSERT(duk_is_lightfunc(thr, -1) || duk_is_callable(thr, -1));
}
}
/* Lightfuncs cannot be bound but are always callable and
* constructable.
*/
}