duk_ret_t duk_bi_duktape_object_act(duk_context *ctx) {
duk_hthread *thr = (duk_hthread *) ctx;
duk_activation *act;
duk_hobject *h_func;
duk_uint_fast32_t pc;
duk_uint_fast32_t line;
duk_int_t level;
/* -1 = top callstack entry, callstack[callstack_top - 1]
* -callstack_top = bottom callstack entry, callstack[0]
*/
level = duk_to_int(ctx, 0);
if (level >= 0 || -level > (duk_int_t) thr->callstack_top) {
return 0;
}
DUK_ASSERT(level >= -((duk_int_t) thr->callstack_top) && level <= -1);
act = thr->callstack + thr->callstack_top + level;
duk_push_object(ctx);
h_func = act->func;
DUK_ASSERT(h_func != NULL);
duk_push_hobject(ctx, h_func);
pc = (duk_uint_fast32_t) act->pc;
duk_push_int(ctx, (int) pc); /* FIXME: typing */
line = duk_hobject_pc2line_query(ctx, -2, pc);
duk_push_int(ctx, (int) line); /* FIXME: typing */
/* Providing access to e.g. act->lex_env would be dangerous: these
* internal structures must never be accessible to the application.
* Duktape relies on them having consistent data, and this consistency
* is only asserted for, not checked for.
*/
/* [ level obj func pc line ] */
/* FIXME: version specific array format instead? */
duk_def_prop_stridx_wec(ctx, -4, DUK_STRIDX_LINE_NUMBER);
duk_def_prop_stridx_wec(ctx, -3, DUK_STRIDX_PC);
duk_def_prop_stridx_wec(ctx, -2, DUK_STRIDX_LC_FUNCTION);
return 1;
}
static void duk__add_traceback(duk_hthread *thr, duk_hthread *thr_callstack, const char *filename, duk_int_t line, duk_bool_t noblame_fileline) {
duk_context *ctx = (duk_context *) thr;
duk_small_uint_t depth;
duk_int_t i, i_min;
duk_uarridx_t arr_idx;
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.txt.
*/
DUK_DDD(DUK_DDDPRINT("adding traceback to object: %!T",
(duk_tval *) duk_get_tval(ctx, -1)));
duk_push_array(ctx); /* XXX: specify array size, as we know it */
arr_idx = 0;
/* 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.
*/
/* XXX: optimize: allocate an array part to the necessary size (upwards
* estimate) and fill in the values directly into the array part; finally
* update 'length'.
*/
/* XXX: using duk_put_prop_index() would cause obscure error cases when Array.prototype
* has write-protected array index named properties. This was seen as DoubleErrors
* in e.g. some test262 test cases. Using duk_def_prop_index() is better but heavier.
* The best fix is to fill in the tracedata directly into the array part.
*/
/* [ ... error arr ] */
if (filename) {
duk_push_string(ctx, filename);
duk_def_prop_index_wec(ctx, -2, arr_idx);
arr_idx++;
d = (noblame_fileline ? ((duk_double_t) DUK_TB_FLAG_NOBLAME_FILELINE) * DUK_DOUBLE_2TO32 : 0.0) +
(duk_double_t) line;
duk_push_number(ctx, d);
duk_def_prop_index_wec(ctx, -2, arr_idx);
arr_idx++;
}
/* 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 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;
/*
* 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(thr_callstack->callstack[i].func != NULL);
DUK_ASSERT_DISABLE(thr_callstack->callstack[i].pc >= 0); /* unsigned */
/* add function */
duk_push_hobject(ctx, thr_callstack->callstack[i].func); /* -> [... arr func] */
duk_def_prop_index_wec(ctx, -2, arr_idx);
arr_idx++;
/* add a number containing: pc, activation flags */
/* Add a number containing: pc, activation flag
*
* PC points to next instruction, find offending PC. Note that
* PC == 0 for native code.
*/
pc = thr_callstack->callstack[i].pc;
if (pc > 0) {
pc--;
}
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_push_number(ctx, d); /* -> [... arr num] */
duk_def_prop_index_wec(ctx, -2, arr_idx);
arr_idx++;
}
/* XXX: set with duk_hobject_set_length() when tracedata is filled directly */
duk_push_uint(ctx, (duk_uint_t) arr_idx);
duk_def_prop_stridx(ctx, -2, DUK_STRIDX_LENGTH, DUK_PROPDESC_FLAGS_WC);
/* [ ... error arr ] */
duk_def_prop_stridx_wec(ctx, -2, DUK_STRIDX_TRACEDATA); /* -> [ ... error ] */
}
