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/*!
* Methods for the various MIR types. These are intended for use after
* building is complete.
*/
use crate::mir::*;
use crate::ty::subst::Subst;
use crate::ty::{self, Ty, TyCtxt};
use rustc_hir as hir;
use rustc_target::abi::VariantIdx;
#[derive(Copy, Clone, Debug, TypeFoldable)]
pub struct PlaceTy<'tcx> {
pub ty: Ty<'tcx>,
/// Downcast to a particular variant of an enum, if included.
pub variant_index: Option<VariantIdx>,
}
// At least on 64 bit systems, `PlaceTy` should not be larger than two or three pointers.
#[cfg(target_arch = "x86_64")]
static_assert_size!(PlaceTy<'_>, 16);
impl<'tcx> PlaceTy<'tcx> {
pub fn from_ty(ty: Ty<'tcx>) -> PlaceTy<'tcx> {
PlaceTy { ty, variant_index: None }
}
/// `place_ty.field_ty(tcx, f)` computes the type at a given field
/// of a record or enum-variant. (Most clients of `PlaceTy` can
/// instead just extract the relevant type directly from their
/// `PlaceElem`, but some instances of `ProjectionElem<V, T>` do
/// not carry a `Ty` for `T`.)
///
/// Note that the resulting type has not been normalized.
pub fn field_ty(self, tcx: TyCtxt<'tcx>, f: &Field) -> Ty<'tcx> {
let answer = match self.ty.kind() {
ty::Adt(adt_def, substs) => {
let variant_def = match self.variant_index {
None => adt_def.non_enum_variant(),
Some(variant_index) => {
assert!(adt_def.is_enum());
&adt_def.variants[variant_index]
}
};
let field_def = &variant_def.fields[f.index()];
field_def.ty(tcx, substs)
}
ty::Tuple(ref tys) => tys[f.index()].expect_ty(),
_ => bug!("extracting field of non-tuple non-adt: {:?}", self),
};
debug!("field_ty self: {:?} f: {:?} yields: {:?}", self, f, answer);
answer
}
/// Convenience wrapper around `projection_ty_core` for
/// `PlaceElem`, where we can just use the `Ty` that is already
/// stored inline on field projection elems.
pub fn projection_ty(self, tcx: TyCtxt<'tcx>, elem: PlaceElem<'tcx>) -> PlaceTy<'tcx> {
self.projection_ty_core(tcx, ty::ParamEnv::empty(), &elem, |_, _, ty| ty)
}
/// `place_ty.projection_ty_core(tcx, elem, |...| { ... })`
/// projects `place_ty` onto `elem`, returning the appropriate
/// `Ty` or downcast variant corresponding to that projection.
/// The `handle_field` callback must map a `Field` to its `Ty`,
/// (which should be trivial when `T` = `Ty`).
pub fn projection_ty_core<V, T>(
self,
tcx: TyCtxt<'tcx>,
param_env: ty::ParamEnv<'tcx>,
elem: &ProjectionElem<V, T>,
mut handle_field: impl FnMut(&Self, &Field, &T) -> Ty<'tcx>,
) -> PlaceTy<'tcx>
where
V: ::std::fmt::Debug,
T: ::std::fmt::Debug,
{
let answer = match *elem {
ProjectionElem::Deref => {
let ty = self
.ty
.builtin_deref(true)
.unwrap_or_else(|| {
bug!("deref projection of non-dereferenceable ty {:?}", self)
})
.ty;
PlaceTy::from_ty(ty)
}
ProjectionElem::Index(_) | ProjectionElem::ConstantIndex { .. } => {
PlaceTy::from_ty(self.ty.builtin_index().unwrap())
}
ProjectionElem::Subslice { from, to, from_end } => {
PlaceTy::from_ty(match self.ty.kind() {
ty::Slice(..) => self.ty,
ty::Array(inner, _) if !from_end => tcx.mk_array(inner, (to - from) as u64),
ty::Array(inner, size) if from_end => {
let size = size.eval_usize(tcx, param_env);
let len = size - (from as u64) - (to as u64);
tcx.mk_array(inner, len)
}
_ => bug!("cannot subslice non-array type: `{:?}`", self),
})
}
ProjectionElem::Downcast(_name, index) => {
PlaceTy { ty: self.ty, variant_index: Some(index) }
}
ProjectionElem::Field(ref f, ref fty) => PlaceTy::from_ty(handle_field(&self, f, fty)),
};
debug!("projection_ty self: {:?} elem: {:?} yields: {:?}", self, elem, answer);
answer
}
}
impl<'tcx> Place<'tcx> {
pub fn ty_from<D>(
local: Local,
projection: &[PlaceElem<'tcx>],
local_decls: &D,
tcx: TyCtxt<'tcx>,
) -> PlaceTy<'tcx>
where
D: HasLocalDecls<'tcx>,
{
projection
.iter()
.fold(PlaceTy::from_ty(local_decls.local_decls()[local].ty), |place_ty, &elem| {
place_ty.projection_ty(tcx, elem)
})
}
pub fn ty<D>(&self, local_decls: &D, tcx: TyCtxt<'tcx>) -> PlaceTy<'tcx>
where
D: HasLocalDecls<'tcx>,
{
Place::ty_from(self.local, &self.projection, local_decls, tcx)
}
}
pub enum RvalueInitializationState {
Shallow,
Deep,
}
impl<'tcx> Rvalue<'tcx> {
pub fn ty<D>(&self, local_decls: &D, tcx: TyCtxt<'tcx>) -> Ty<'tcx>
where
D: HasLocalDecls<'tcx>,
{
match *self {
Rvalue::Use(ref operand) => operand.ty(local_decls, tcx),
Rvalue::Repeat(ref operand, count) => {
tcx.mk_ty(ty::Array(operand.ty(local_decls, tcx), count))
}
Rvalue::ThreadLocalRef(did) => {
if tcx.is_mutable_static(did) {
tcx.mk_mut_ptr(tcx.type_of(did))
} else {
tcx.mk_imm_ref(tcx.lifetimes.re_static, tcx.type_of(did))
}
}
Rvalue::Ref(reg, bk, ref place) => {
let place_ty = place.ty(local_decls, tcx).ty;
tcx.mk_ref(reg, ty::TypeAndMut { ty: place_ty, mutbl: bk.to_mutbl_lossy() })
}
Rvalue::AddressOf(mutability, ref place) => {
let place_ty = place.ty(local_decls, tcx).ty;
tcx.mk_ptr(ty::TypeAndMut { ty: place_ty, mutbl: mutability })
}
Rvalue::Len(..) => tcx.types.usize,
Rvalue::Cast(.., ty) => ty,
Rvalue::BinaryOp(op, ref lhs, ref rhs) => {
let lhs_ty = lhs.ty(local_decls, tcx);
let rhs_ty = rhs.ty(local_decls, tcx);
op.ty(tcx, lhs_ty, rhs_ty)
}
Rvalue::CheckedBinaryOp(op, ref lhs, ref rhs) => {
let lhs_ty = lhs.ty(local_decls, tcx);
let rhs_ty = rhs.ty(local_decls, tcx);
let ty = op.ty(tcx, lhs_ty, rhs_ty);
tcx.intern_tup(&[ty, tcx.types.bool])
}
Rvalue::UnaryOp(UnOp::Not | UnOp::Neg, ref operand) => operand.ty(local_decls, tcx),
Rvalue::Discriminant(ref place) => place.ty(local_decls, tcx).ty.discriminant_ty(tcx),
Rvalue::NullaryOp(NullOp::Box, t) => tcx.mk_box(t),
Rvalue::NullaryOp(NullOp::SizeOf, _) => tcx.types.usize,
Rvalue::Aggregate(ref ak, ref ops) => match **ak {
AggregateKind::Array(ty) => tcx.mk_array(ty, ops.len() as u64),
AggregateKind::Tuple => tcx.mk_tup(ops.iter().map(|op| op.ty(local_decls, tcx))),
AggregateKind::Adt(def, _, substs, _, _) => tcx.type_of(def.did).subst(tcx, substs),
AggregateKind::Closure(did, substs) => tcx.mk_closure(did, substs),
AggregateKind::Generator(did, substs, movability) => {
tcx.mk_generator(did, substs, movability)
}
},
}
}
#[inline]
/// Returns `true` if this rvalue is deeply initialized (most rvalues) or
/// whether its only shallowly initialized (`Rvalue::Box`).
pub fn initialization_state(&self) -> RvalueInitializationState {
match *self {
Rvalue::NullaryOp(NullOp::Box, _) => RvalueInitializationState::Shallow,
_ => RvalueInitializationState::Deep,
}
}
}
impl<'tcx> Operand<'tcx> {
pub fn ty<D>(&self, local_decls: &D, tcx: TyCtxt<'tcx>) -> Ty<'tcx>
where
D: HasLocalDecls<'tcx>,
{
match self {
&Operand::Copy(ref l) | &Operand::Move(ref l) => l.ty(local_decls, tcx).ty,
&Operand::Constant(ref c) => c.literal.ty,
}
}
}
impl<'tcx> BinOp {
pub fn ty(&self, tcx: TyCtxt<'tcx>, lhs_ty: Ty<'tcx>, rhs_ty: Ty<'tcx>) -> Ty<'tcx> {
// FIXME: handle SIMD correctly
match self {
&BinOp::Add
| &BinOp::Sub
| &BinOp::Mul
| &BinOp::Div
| &BinOp::Rem
| &BinOp::BitXor
| &BinOp::BitAnd
| &BinOp::BitOr => {
// these should be integers or floats of the same size.
assert_eq!(lhs_ty, rhs_ty);
lhs_ty
}
&BinOp::Shl | &BinOp::Shr | &BinOp::Offset => {
lhs_ty // lhs_ty can be != rhs_ty
}
&BinOp::Eq | &BinOp::Lt | &BinOp::Le | &BinOp::Ne | &BinOp::Ge | &BinOp::Gt => {
tcx.types.bool
}
}
}
}
impl BorrowKind {
pub fn to_mutbl_lossy(self) -> hir::Mutability {
match self {
BorrowKind::Mut { .. } => hir::Mutability::Mut,
BorrowKind::Shared => hir::Mutability::Not,
// We have no type corresponding to a unique imm borrow, so
// use `&mut`. It gives all the capabilities of an `&uniq`
// and hence is a safe "over approximation".
BorrowKind::Unique => hir::Mutability::Mut,
// We have no type corresponding to a shallow borrow, so use
// `&` as an approximation.
BorrowKind::Shallow => hir::Mutability::Not,
}
}
}
impl BinOp {
pub fn to_hir_binop(self) -> hir::BinOpKind {
match self {
BinOp::Add => hir::BinOpKind::Add,
BinOp::Sub => hir::BinOpKind::Sub,
BinOp::Mul => hir::BinOpKind::Mul,
BinOp::Div => hir::BinOpKind::Div,
BinOp::Rem => hir::BinOpKind::Rem,
BinOp::BitXor => hir::BinOpKind::BitXor,
BinOp::BitAnd => hir::BinOpKind::BitAnd,
BinOp::BitOr => hir::BinOpKind::BitOr,
BinOp::Shl => hir::BinOpKind::Shl,
BinOp::Shr => hir::BinOpKind::Shr,
BinOp::Eq => hir::BinOpKind::Eq,
BinOp::Ne => hir::BinOpKind::Ne,
BinOp::Lt => hir::BinOpKind::Lt,
BinOp::Gt => hir::BinOpKind::Gt,
BinOp::Le => hir::BinOpKind::Le,
BinOp::Ge => hir::BinOpKind::Ge,
BinOp::Offset => unreachable!(),
}
}
}