/*
* Global symbol enumeration callback - fix up this symbol's compiler
* metaclass identifier, if this is an object symbol.
*/
static void fix_obj_meta_cb(void *ctx0, CTcSymbol *sym)
{
/* cast our context and set up to access VM globals */
fix_obj_meta_cb_ctx *ctx = (fix_obj_meta_cb_ctx *)ctx0;
VMGLOB_PTR(ctx->vmg);
/* if this is an object symbol, fix up its metaclass identifier */
if (sym->get_type() == TC_SYM_OBJ)
{
CVmObject *obj;
CVmMetaclass *meta;
uint idx;
tc_metaclass_t id;
/* cast the symbol to an object symbol */
CTcSymObj *obj_sym = (CTcSymObj *)sym;
/* get the object */
obj = vm_objp(vmg_ (vm_obj_id_t)obj_sym->get_obj_id());
/* look up its metaclass */
meta = obj->get_metaclass_reg();
/* get the registration table index */
idx = meta->get_reg_idx();
/* that's our index into the translation table - look it up */
id = ctx->xlat[idx];
/* store the compiler metaclass ID back in the symbol */
obj_sym->set_metaclass(id);
}
}
void CVmBifT3::get_stack_trace(VMG_ uint argc)
{
int single_level = 0;
int level;
vm_val_t *fp;
vm_val_t lst_val;
CVmObjList *lst;
const uchar *entry_addr;
ulong method_ofs;
vm_val_t stack_info_cls;
int want_named_args = FALSE;
int want_locals = FALSE;
int want_frefs = FALSE;
int flags = 0;
const vm_rcdesc *rc;
/* check arguments */
check_argc_range(vmg_ argc, 0, 2);
/* get the imported stack information class */
stack_info_cls.set_obj(G_predef->stack_info_cls);
if (stack_info_cls.val.obj == VM_INVALID_OBJ)
{
/*
* there's no stack information class - we can't return any
* meaningful information, so just return nil
*/
retval_nil(vmg0_);
return;
}
/*
* look up T3StackInfo.construct() to determine how many arguments it
* wants
*/
{
int min_args, opt_args, varargs;
if (vm_objp(vmg_ stack_info_cls.val.obj)->get_prop_interface(
vmg_ stack_info_cls.val.obj, G_predef->obj_construct,
min_args, opt_args, varargs))
{
/* check to see how many extra arguments they want */
want_named_args = (min_args + opt_args >= 7 || varargs);
want_locals = (min_args + opt_args >= 8 || varargs);
want_frefs = (min_args + opt_args >= 9 || varargs);
}
}
/* check to see if we're fetching a single level or the full trace */
if (argc >= 1)
{
/*
* Get the single level, and adjust to a 0 base. If the level is
* nil, we're still getting all levels.
*/
if (G_stk->get(0)->typ == VM_NIL)
{
/* it's nil - get all levels */
G_stk->discard();
}
else
{
/* get the level number */
single_level = pop_int_val(vmg0_);
/* make sure it's in range */
if (single_level <= 0)
err_throw(VMERR_BAD_VAL_BIF);
/* we won't need a return list */
lst_val.set_obj_or_nil(VM_INVALID_OBJ);
lst = 0;
}
}
/* get the flags argument, if present */
if (argc >= 2)
flags = pop_int_val(vmg0_);
/* if we're not doing a single level, we need a list for the result */
if (!single_level)
{
/*
* We're returning a full list, so we need to allocate the list for
* the return value. First, count stack levels to see how big a
* list we'll need.
*/
fp = G_interpreter->get_frame_ptr();
entry_addr = G_interpreter->get_entry_ptr();
method_ofs = G_interpreter->get_method_ofs();
for (level = 0 ; fp != 0 ;
fp = G_interpreter->get_enclosing_frame_ptr(vmg_ fp), ++level)
{
/* add an extra level for each system call */
if (method_ofs == 0 && entry_addr != 0)
++level;
/* get the return address */
entry_addr =
G_interpreter->get_enclosing_entry_ptr_from_frame(vmg_ fp);
method_ofs = G_interpreter->get_return_ofs_from_frame(vmg_ fp);
}
/* create the list */
lst_val.set_obj(CVmObjList::create(vmg_ FALSE, level));
lst = (CVmObjList *)vm_objp(vmg_ lst_val.val.obj);
/*
* we create other objects while building this list, so the gc
* could run - clear the list to ensure it contains valid data
*/
lst->cons_clear();
/* protect the list from garbage collection while we work */
G_stk->push(&lst_val);
/* flag that we're doing the whole stack */
single_level = -1;
}
else
{
/* adjust the level to a 0-based index */
single_level -= 1;
}
/* set up at the current function */
fp = G_interpreter->get_frame_ptr();
entry_addr = G_interpreter->get_entry_ptr();
method_ofs = G_interpreter->get_method_ofs();
rc = 0;
/* traverse the frames */
for (level = 0 ; fp != 0 ; ++level)
{
int fr_argc;
int i;
vm_obj_id_t def_obj;
vm_val_t info_self;
vm_val_t info_func;
vm_val_t info_obj;
vm_val_t info_prop;
vm_val_t info_args;
vm_val_t info_locals;
vm_val_t info_srcloc;
vm_val_t info_frameref;
CVmObjList *arglst;
vm_val_t ele;
CVmFuncPtr func_ptr;
int gc_cnt = 0;
int info_argc = 0;
/* if we're looking for a single level, and this isn't it, skip it */
if (single_level >= 0 && level != single_level)
goto done_with_level;
/*
* start with the information values to nil - we'll set the
* appropriate ones when we find out what we have
*/
info_func.set_nil();
info_obj.set_nil();
info_prop.set_nil();
info_self.set_nil();
info_locals.set_nil();
info_frameref.set_nil();
/* get the number of arguments to the function in this frame */
fr_argc = G_interpreter->get_argc_from_frame(vmg_ fp);
/* set up a function pointer for the method's entry address */
func_ptr.set(entry_addr);
/* get the current frame's defining object */
def_obj = G_interpreter->get_defining_obj_from_frame(vmg_ fp);
/* check for special method offsets */
switch (method_ofs)
{
case VMRUN_RET_OP:
/* the real return address is one past the last argument */
method_ofs = G_interpreter->get_param_from_frame(vmg_ fp, argc)
->val.intval;
break;
case VMRUN_RET_OP_ASILCL:
/* the real return address is two past the last argument */
method_ofs = G_interpreter->get_param_from_frame(vmg_ fp, argc+1)
->val.intval;
break;
}
/* determine whether it's an object.prop or a function call */
if (method_ofs == 0)
{
/*
* A zero method offset indicates a recursive VM invocation
* from a native function. Presume we have no information on
* the caller.
*/
info_self.set_nil();
fr_argc = 0;
/* check for a native caller context */
if (rc != 0)
{
/* check which kind of native caller we have */
if (rc->bifptr.typ != VM_NIL)
{
/* we have a built-in function at this level */
info_func = rc->bifptr;
}
else if (rc->self.typ != VM_NIL)
{
/* it's an intrinsic class method - get the 'self' */
info_obj = info_self = rc->self;
/* get the metaclass */
CVmMetaclass *mc;
switch (info_obj.typ)
{
case VM_OBJ:
/* get the metaclass from the object */
mc = vm_objp(vmg_ info_obj.val.obj)
->get_metaclass_reg();
break;
case VM_LIST:
/* list constant - use the List metaclass */
mc = CVmObjList::metaclass_reg_;
break;
case VM_SSTRING:
/* string constant - use the String metaclass */
mc = CVmObjString::metaclass_reg_;
break;
default:
/* other types don't have metaclasses */
mc = 0;
break;
}
/* get the registration table entry */
vm_meta_entry_t *me =
mc == 0 ? 0 :
G_meta_table->get_entry_from_reg(mc->get_reg_idx());
/* get the metaclass and property from the entry */
if (me != 0)
{
/* set 'obj' to the IntrinsicClass object */
info_obj.set_obj(me->class_obj_);
/* get the property ID */
info_prop.set_propid(me->xlat_func(rc->method_idx));
}
}
}
}
else if (def_obj == VM_INVALID_OBJ)
{
/* there's no defining object, so this is a function call */
func_ptr.get_fnptr(vmg_ &info_func);
}
else
{
/* it's an object.prop invocation */
info_obj.set_obj(def_obj); // $$$ walk up to base modified obj?
info_prop.set_propid(
G_interpreter->get_target_prop_from_frame(vmg_ fp));
/* get the 'self' in this frame */
info_self.set_obj(G_interpreter->get_self_from_frame(vmg_ fp));
}
/*
* build the argument list and source location, except for system
* routines
*/
if (method_ofs != 0 || rc != 0)
{
/* allocate a list object to store the argument list */
int ac = (rc != 0 ? rc->argc : fr_argc);
info_args.set_obj(CVmObjList::create(vmg_ FALSE, ac));
arglst = (CVmObjList *)vm_objp(vmg_ info_args.val.obj);
/* push the argument list for gc protection */
G_stk->push(&info_args);
++gc_cnt;
/* build the argument list */
for (i = 0 ; i < ac ; ++i)
{
/* add this element to the argument list */
const vm_val_t *v =
(rc != 0
? rc->argp - i
: G_interpreter->get_param_from_frame(vmg_ fp, i));
arglst->cons_set_element(i, v);
}
/* get the source location */
get_source_info(vmg_ entry_addr, method_ofs, &info_srcloc);
/*
* if they want locals, and this isn't a recursive native
* caller, retrieve them
*/
if (rc == 0
&& (((flags & T3_GST_LOCALS) != 0 && want_locals)
|| ((flags & T3_GST_FREFS) != 0 && want_frefs)))
{
/* get the locals */
get_stack_locals(vmg_ fp, entry_addr, method_ofs,
(flags & T3_GST_LOCALS) != 0 && want_locals
? &info_locals : 0,
(flags & T3_GST_FREFS) != 0 && want_frefs
? &info_frameref : 0);
/*
* that leaves the LookupTable and StackFrameDesc on the
* stack, so note that we need to discard the stack level
* when we're done with it
*/
if (info_locals.typ == VM_OBJ)
++gc_cnt;
if (info_frameref.typ == VM_OBJ)
++gc_cnt;
}
}
else
{
/*
* it's a system routine - no argument information is
* available, so return nil rather than an empty list to to
* indicate the absence
*/
info_args.set_nil();
/* there's obviously no source location for system code */
info_srcloc.set_nil();
}
/*
* We have all of the information on this level now, so create the
* information object for the level. This is an object of the
* exported stack-info class, which is a TadsObject type.
*/
/* start with the original complement of arguments */
info_argc = 7;
/*
* if we have a modern T3StackInfo object, push the locals,
* named argument elements, and frame reference object
*/
if (want_frefs)
{
G_stk->push(&info_frameref);
++info_argc;
}
if (want_named_args)
{
/*
* the constructor has a slot for named arguments - push either
* a table or nil, depending...
*/
vm_val_t *argp;
const uchar *t = 0;
/* if the flags request locals, retrieve the named arguments */
if ((flags & T3_GST_LOCALS) != 0)
t = CVmRun::get_named_args_from_frame(vmg_ fp, &argp);
/*
* if we do in fact have named arguments, build a lookup table
* copy and push it; otherwise just push nil
*/
if (t != 0)
{
/* get the number of table entries */
int n = osrp2(t);
t += 2;
/* create a lookup table for the arguments */
G_stk->push()->set_obj(CVmObjLookupTable::create(
vmg_ FALSE, n <= 8 ? 8 : n <= 32 ? 32 : 64, n));
CVmObjLookupTable *lt = (CVmObjLookupTable *)vm_objp(
vmg_ G_stk->get(0)->val.obj);
/*
* Populate the lookup table with the named arguments. The
* compiler builds the table in the order pushed, which is
* right to left. Lookup tables preserve the order in
* which elements are added, and reflect this order in key
* lists, so to that extent the order of building the
* lookup table matters. For readability of the generated
* list, in case it's presented to the user, build the
* table in left-to-right order, which is the reverse of
* the table order in the bytecode table.
*/
argp += n - 1;
for (int i = (n-1)*2 ; i >= 0 ; i -= 2, --argp)
{
/* get the name pointer and length from the index */
uint ofs = osrp2(t + i), nxtofs = osrp2(t + i + 2);
const char *name = (const char *)t + ofs;
size_t len = nxtofs - ofs;
/* create a string from the name */
vm_val_t str;
str.set_obj(CVmObjString::create(vmg_ FALSE, name, len));
/* add it to the table */
lt->add_entry(vmg_ &str, argp);
}
}
else
{
/* there are no named arguments - push nil */
G_stk->push()->set_nil();
}
/* count the argument */
++info_argc;
}
if (want_locals)
{
G_stk->push(&info_locals);
++info_argc;
}
/* push the rest of the arguments */
G_stk->push(&info_srcloc);
G_stk->push(&info_args);
G_stk->push(&info_self);
G_stk->push(&info_prop);
G_stk->push(&info_obj);
G_stk->push(&info_func);
G_stk->push(&stack_info_cls);
ele.set_obj(CVmObjTads::create_from_stack(vmg_ 0, info_argc));
/* discard the gc protection items */
G_stk->discard(gc_cnt);
/*
* if we're fetching a single level, this is it - return the new
* stack info object and we're done
*/
if (single_level >= 0)
{
/* return the single level object */
retval_obj(vmg_ ele.val.obj);
/* we're done */
return;
}
/* add the new element to our list */
lst->cons_set_element(level, &ele);
done_with_level:
/*
* If this is a system call level, and we're not in debug mode,
* this recursive frame contains the entry address for the caller,
* but not the calling byte-code address. Stay on the current
* level in this case.
*/
if (method_ofs == 0 && entry_addr != 0)
{
/*
* This is a recursive caller, and we have a valid entry
* address for the prior frame. Stay in the current frame, and
* retrieve the actual return address from the calling frame.
*/
if (rc != 0)
{
/* get the actual return address from the recursive context */
method_ofs = rc->return_addr - entry_addr;
/*
* we're now in the bytecode part of the frame, so forget
* the recursive context
*/
rc = 0;
}
else
{
/* no recursive context - use a fake return address */
method_ofs = G_interpreter->get_funchdr_size();
}
}
else
{
/* move up to the enclosing frame */
entry_addr =
G_interpreter->get_enclosing_entry_ptr_from_frame(vmg_ fp);
method_ofs = G_interpreter->get_return_ofs_from_frame(vmg_ fp);
rc = G_interpreter->get_rcdesc_from_frame(vmg_ fp);
fp = G_interpreter->get_enclosing_frame_ptr(vmg_ fp);
}
}
/* return the list */
retval_obj(vmg_ lst_val.val.obj);
/* discard our gc protection */
G_stk->discard();
}