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use rustc::mir;
use rustc::ty::{self, Ty};
use rustc::ty::layout::LayoutOf;
use syntax::codemap::Span;
use rustc_target::spec::abi::Abi;
use rustc::mir::interpret::EvalResult;
use super::{EvalContext, Place, Machine, ValTy};
use rustc_data_structures::indexed_vec::Idx;
use interpret::memory::HasMemory;
mod drop;
impl<'a, 'mir, 'tcx, M: Machine<'mir, 'tcx>> EvalContext<'a, 'mir, 'tcx, M> {
pub fn goto_block(&mut self, target: mir::BasicBlock) {
self.frame_mut().block = target;
self.frame_mut().stmt = 0;
}
pub(super) fn eval_terminator(
&mut self,
terminator: &mir::Terminator<'tcx>,
) -> EvalResult<'tcx> {
use rustc::mir::TerminatorKind::*;
match terminator.kind {
Return => {
self.dump_local(self.frame().return_place);
self.pop_stack_frame()?
}
Goto { target } => self.goto_block(target),
SwitchInt {
ref discr,
ref values,
ref targets,
..
} => {
let discr_val = self.eval_operand(discr)?;
let discr_prim = self.value_to_scalar(discr_val)?;
let discr_layout = self.layout_of(discr_val.ty).unwrap();
trace!("SwitchInt({:?}, {:#?})", discr_prim, discr_layout);
let discr_prim = discr_prim.to_bits(discr_layout.size)?;
let mut target_block = targets[targets.len() - 1];
for (index, &const_int) in values.iter().enumerate() {
if discr_prim == const_int {
target_block = targets[index];
break;
}
}
self.goto_block(target_block);
}
Call {
ref func,
ref args,
ref destination,
..
} => {
let destination = match *destination {
Some((ref lv, target)) => Some((self.eval_place(lv)?, target)),
None => None,
};
let func = self.eval_operand(func)?;
let (fn_def, sig) = match func.ty.sty {
ty::TyFnPtr(sig) => {
let fn_ptr = self.value_to_scalar(func)?.to_ptr()?;
let instance = self.memory.get_fn(fn_ptr)?;
let instance_ty = instance.ty(*self.tcx);
match instance_ty.sty {
ty::TyFnDef(..) => {
let real_sig = instance_ty.fn_sig(*self.tcx);
let sig = self.tcx.normalize_erasing_late_bound_regions(
ty::ParamEnv::reveal_all(),
&sig,
);
let real_sig = self.tcx.normalize_erasing_late_bound_regions(
ty::ParamEnv::reveal_all(),
&real_sig,
);
if !self.check_sig_compat(sig, real_sig)? {
return err!(FunctionPointerTyMismatch(real_sig, sig));
}
}
ref other => bug!("instance def ty: {:?}", other),
}
(instance, sig)
}
ty::TyFnDef(def_id, substs) => (
self.resolve(def_id, substs)?,
func.ty.fn_sig(*self.tcx),
),
_ => {
let msg = format!("can't handle callee of type {:?}", func.ty);
return err!(Unimplemented(msg));
}
};
let args = self.operands_to_args(args)?;
let sig = self.tcx.normalize_erasing_late_bound_regions(
ty::ParamEnv::reveal_all(),
&sig,
);
self.eval_fn_call(
fn_def,
destination,
&args,
terminator.source_info.span,
sig,
)?;
}
Drop {
ref location,
target,
..
} => {
let place = self.eval_place(location)?;
let ty = self.place_ty(location);
let ty = self.tcx.subst_and_normalize_erasing_regions(
self.substs(),
ty::ParamEnv::reveal_all(),
&ty,
);
trace!("TerminatorKind::drop: {:?}, type {}", location, ty);
let instance = ::monomorphize::resolve_drop_in_place(*self.tcx, ty);
self.drop_place(
place,
instance,
ty,
terminator.source_info.span,
target,
)?;
}
Assert {
ref cond,
expected,
ref msg,
target,
..
} => {
let cond_val = self.eval_operand_to_scalar(cond)?.to_bool()?;
if expected == cond_val {
self.goto_block(target);
} else {
use rustc::mir::interpret::EvalErrorKind::*;
return match *msg {
BoundsCheck { ref len, ref index } => {
let len = self.eval_operand_to_scalar(len)
.expect("can't eval len")
.to_bits(self.memory().pointer_size())? as u64;
let index = self.eval_operand_to_scalar(index)
.expect("can't eval index")
.to_bits(self.memory().pointer_size())? as u64;
err!(BoundsCheck { len, index })
}
Overflow(op) => Err(Overflow(op).into()),
OverflowNeg => Err(OverflowNeg.into()),
DivisionByZero => Err(DivisionByZero.into()),
RemainderByZero => Err(RemainderByZero.into()),
GeneratorResumedAfterReturn |
GeneratorResumedAfterPanic => unimplemented!(),
_ => bug!(),
};
}
}
Yield { .. } => unimplemented!("{:#?}", terminator.kind),
GeneratorDrop => unimplemented!(),
DropAndReplace { .. } => unimplemented!(),
Resume => unimplemented!(),
Abort => unimplemented!(),
FalseEdges { .. } => bug!("should have been eliminated by `simplify_branches` mir pass"),
FalseUnwind { .. } => bug!("should have been eliminated by `simplify_branches` mir pass"),
Unreachable => return err!(Unreachable),
}
Ok(())
}
fn check_sig_compat(
&mut self,
sig: ty::FnSig<'tcx>,
real_sig: ty::FnSig<'tcx>,
) -> EvalResult<'tcx, bool> {
fn check_ty_compat<'tcx>(ty: Ty<'tcx>, real_ty: Ty<'tcx>) -> bool {
if ty == real_ty {
return true;
}
return match (&ty.sty, &real_ty.sty) {
(&ty::TyRawPtr(_), &ty::TyRawPtr(_)) => true,
(&ty::TyRef(_, _, _), &ty::TyRef(_, _, _)) => {
ty.is_mutable_pointer() == real_ty.is_mutable_pointer()
}
_ => false,
};
}
if sig.abi == real_sig.abi && sig.variadic == real_sig.variadic &&
sig.inputs_and_output.len() == real_sig.inputs_and_output.len() &&
sig.inputs_and_output
.iter()
.zip(real_sig.inputs_and_output)
.all(|(ty, real_ty)| check_ty_compat(ty, real_ty))
{
return Ok(true);
}
if sig.variadic || real_sig.variadic {
return Ok(false);
}
match (sig.abi, real_sig.abi) {
(Abi::Rust, Abi::RustCall)
if check_ty_compat(sig.output(), real_sig.output()) && real_sig.inputs_and_output.len() == 3 => {
let fst_ty = real_sig.inputs_and_output[0];
if self.layout_of(fst_ty)?.is_zst() {
let snd_ty = real_sig.inputs_and_output[1];
match snd_ty.sty {
ty::TyTuple(tys) if sig.inputs().len() == tys.len() =>
if sig.inputs().iter().zip(tys).all(|(ty, real_ty)| check_ty_compat(ty, real_ty)) {
return Ok(true)
},
_ => {}
}
}
}
_ => {}
};
return Ok(false);
}
fn eval_fn_call(
&mut self,
instance: ty::Instance<'tcx>,
destination: Option<(Place, mir::BasicBlock)>,
args: &[ValTy<'tcx>],
span: Span,
sig: ty::FnSig<'tcx>,
) -> EvalResult<'tcx> {
trace!("eval_fn_call: {:#?}", instance);
match instance.def {
ty::InstanceDef::Intrinsic(..) => {
let (ret, target) = match destination {
Some(dest) => dest,
_ => return err!(Unreachable),
};
let ty = sig.output();
let layout = self.layout_of(ty)?;
M::call_intrinsic(self, instance, args, ret, layout, target)?;
self.dump_local(ret);
Ok(())
}
ty::InstanceDef::ClosureOnceShim { .. } => {
if M::eval_fn_call(self, instance, destination, args, span, sig)? {
return Ok(());
}
let mut arg_locals = self.frame().mir.args_iter();
match sig.abi {
Abi::RustCall => {
for (arg_local, &valty) in arg_locals.zip(args) {
let dest = self.eval_place(&mir::Place::Local(arg_local))?;
self.write_value(valty, dest)?;
}
}
Abi::Rust => {
trace!(
"arg_locals: {:#?}",
self.frame().mir.args_iter().collect::<Vec<_>>()
);
trace!("args: {:#?}", args);
let local = arg_locals.nth(1).unwrap();
for (i, &valty) in args.into_iter().enumerate() {
let dest = self.eval_place(&mir::Place::Local(local).field(
mir::Field::new(i),
valty.ty,
))?;
self.write_value(valty, dest)?;
}
}
_ => bug!("bad ABI for ClosureOnceShim: {:?}", sig.abi),
}
Ok(())
}
ty::InstanceDef::FnPtrShim(..) |
ty::InstanceDef::DropGlue(..) |
ty::InstanceDef::CloneShim(..) |
ty::InstanceDef::Item(_) => {
if M::eval_fn_call(self, instance, destination, args, span, sig)? {
return Ok(());
}
let mut arg_locals = self.frame().mir.args_iter();
trace!("ABI: {:?}", sig.abi);
trace!(
"arg_locals: {:#?}",
self.frame().mir.args_iter().collect::<Vec<_>>()
);
trace!("args: {:#?}", args);
match sig.abi {
Abi::RustCall => {
assert_eq!(args.len(), 2);
{
let first_local = arg_locals.next().unwrap();
let dest = self.eval_place(&mir::Place::Local(first_local))?;
self.write_value(args[0], dest)?;
}
let layout = self.layout_of(args[1].ty)?;
if let ty::TyTuple(_) = args[1].ty.sty {
if layout.is_zst() {
return Ok(());
}
if self.frame().mir.args_iter().count() == layout.fields.count() + 1 {
for (i, arg_local) in arg_locals.enumerate() {
let field = mir::Field::new(i);
let valty = self.read_field(args[1].value, None, field, args[1].ty)?;
let dest = self.eval_place(&mir::Place::Local(arg_local))?;
self.write_value(valty, dest)?;
}
} else {
trace!("manual impl of rust-call ABI");
let dest = self.eval_place(
&mir::Place::Local(arg_locals.next().unwrap()),
)?;
self.write_value(args[1], dest)?;
}
} else {
bug!(
"rust-call ABI tuple argument was {:#?}, {:#?}",
args[1].ty,
layout
);
}
}
_ => {
for (arg_local, &valty) in arg_locals.zip(args) {
let dest = self.eval_place(&mir::Place::Local(arg_local))?;
self.write_value(valty, dest)?;
}
}
}
Ok(())
}
ty::InstanceDef::Virtual(_, idx) => {
let ptr_size = self.memory.pointer_size();
let ptr_align = self.tcx.data_layout.pointer_align;
let (ptr, vtable) = self.into_ptr_vtable_pair(args[0].value)?;
let fn_ptr = self.memory.read_ptr_sized(
vtable.offset(ptr_size * (idx as u64 + 3), &self)?,
ptr_align
)?.to_ptr()?;
let instance = self.memory.get_fn(fn_ptr)?;
let mut args = args.to_vec();
let ty = self.layout_of(args[0].ty)?.field(&self, 0)?.ty;
args[0].ty = ty;
args[0].value = ptr.to_value();
self.eval_fn_call(instance, destination, &args, span, sig)
}
}
}
}