Object* rbx_add_scope(STATE, CallFrame* call_frame, Object* top) {
Module* mod = as<Module>(top);
StaticScope* scope = StaticScope::create(state);
scope->module(state, mod);
scope->parent(state, call_frame->static_scope());
call_frame->cm->scope(state, scope);
// call_frame->static_scope_ = scope;
return Qnil;
}
void attach_method(STATE, CallFrame* call_frame, Object* recv, Symbol* name, CompiledMethod* method) {
if(Module* mod = try_as<Module>(recv)) {
StaticScope* ss = StaticScope::create(state);
ss->module(state, mod);
ss->parent(state, method->scope());
method->scope(state, ss);
} else {
/* Push the current scope down. */
method->scope(state, call_frame->static_scope());
}
add_method(state, call_frame, recv->metaclass(state), name, method);
}
Object* const_get(STATE, CallFrame* call_frame, Symbol* name, bool* found) {
StaticScope *cur;
Object* result;
*found = false;
call_frame = call_frame->top_ruby_frame();
// Ok, this has to be explained or it will be considered black magic.
// The scope chain always ends with an entry at the top that contains
// a parent of nil, and a module of Object. This entry is put in
// regardless of lexical scoping, it's the default scope.
//
// When looking up a constant, we don't want to consider the default
// scope (ie, Object) initially because we need to lookup up
// the superclass chain first, because falling back on the default.
//
// The rub comes from the fact that if a user explicitly opens up
// Object in their code, we DO consider it. Like:
//
// class Idiot
// A = 2
// end
//
// class ::Object
// A = 1
// class Stupid < Idiot
// def foo
// p A
// end
// end
// end
//
// In this code, when A is looked up, Object must be considering during
// the scope walk, NOT during the superclass walk.
//
// So, in this case, foo would print "1", not "2".
//
cur = call_frame->static_scope();
while(!cur->nil_p()) {
// Detect the toplevel scope (the default) and get outta dodge.
if(cur->top_level_p(state)) break;
result = cur->module()->get_const(state, name, found);
if(*found) return result;
cur = cur->parent();
}
// Now look up the superclass chain.
cur = call_frame->static_scope();
if(!cur->nil_p()) {
Module* mod = cur->module();
while(!mod->nil_p()) {
result = mod->get_const(state, name, found);
if(*found) return result;
mod = mod->superclass();
}
}
// Lastly, check Object specifically
result = G(object)->get_const(state, name, found, true);
if(*found) return result;
return Qnil;
}