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use rustc::mir::BasicBlock;
use rustc::ty::{self, Ty};
use syntax::codemap::Span;
use rustc::mir::interpret::{EvalResult, Scalar, Value};
use interpret::{Machine, ValTy, EvalContext, Place, PlaceExtra};
impl<'a, 'mir, 'tcx, M: Machine<'mir, 'tcx>> EvalContext<'a, 'mir, 'tcx, M> {
pub(crate) fn drop_place(
&mut self,
place: Place,
instance: ty::Instance<'tcx>,
ty: Ty<'tcx>,
span: Span,
target: BasicBlock,
) -> EvalResult<'tcx> {
trace!("drop_place: {:#?}", place);
let val = match self.force_allocation(place)? {
Place::Ptr {
ptr,
align: _,
extra: PlaceExtra::Vtable(vtable),
} => ptr.to_value_with_vtable(vtable),
Place::Ptr {
ptr,
align: _,
extra: PlaceExtra::Length(len),
} => ptr.to_value_with_len(len, self.tcx.tcx),
Place::Ptr {
ptr,
align: _,
extra: PlaceExtra::None,
} => ptr.to_value(),
_ => bug!("force_allocation broken"),
};
self.drop(val, instance, ty, span, target)
}
fn drop(
&mut self,
arg: Value,
instance: ty::Instance<'tcx>,
ty: Ty<'tcx>,
span: Span,
target: BasicBlock,
) -> EvalResult<'tcx> {
trace!("drop: {:#?}, {:?}, {:?}", arg, ty.sty, instance.def);
let instance = match ty.sty {
ty::TyDynamic(..) => {
let vtable = match arg {
Value::ScalarPair(_, Scalar::Ptr(vtable)) => vtable,
_ => bug!("expected fat ptr, got {:?}", arg),
};
match self.read_drop_type_from_vtable(vtable)? {
Some(func) => func,
None => {
self.goto_block(target);
return Ok(())
},
}
}
_ => instance,
};
let valty = ValTy {
value: arg,
ty: self.tcx.mk_mut_ptr(ty),
};
let fn_sig = self.tcx.fn_sig(instance.def_id()).skip_binder().clone();
self.eval_fn_call(
instance,
Some((Place::undef(), target)),
&vec![valty],
span,
fn_sig,
)
}
}