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use crate::hair::*;
use crate::hair::cx::Cx;
use crate::hair::cx::block;
use crate::hair::cx::to_ref::ToRef;
use crate::hair::util::UserAnnotatedTyHelpers;
use rustc_data_structures::indexed_vec::Idx;
use rustc::hir::def::{CtorOf, Res, DefKind, CtorKind};
use rustc::mir::interpret::{GlobalId, ErrorHandled, ConstValue};
use rustc::ty::{self, AdtKind, Ty};
use rustc::ty::adjustment::{Adjustment, Adjust, AutoBorrow, AutoBorrowMutability, PointerCast};
use rustc::ty::subst::{InternalSubsts, SubstsRef};
use rustc::hir;
use rustc::hir::def_id::LocalDefId;
use rustc::mir::BorrowKind;
use syntax_pos::Span;
impl<'tcx> Mirror<'tcx> for &'tcx hir::Expr {
type Output = Expr<'tcx>;
fn make_mirror(self, cx: &mut Cx<'_, 'tcx>) -> Expr<'tcx> {
let temp_lifetime = cx.region_scope_tree.temporary_scope(self.hir_id.local_id);
let expr_scope = region::Scope {
id: self.hir_id.local_id,
data: region::ScopeData::Node
};
debug!("Expr::make_mirror(): id={}, span={:?}", self.hir_id, self.span);
let mut expr = make_mirror_unadjusted(cx, self);
// Now apply adjustments, if any.
for adjustment in cx.tables().expr_adjustments(self) {
debug!("make_mirror: expr={:?} applying adjustment={:?}",
expr,
adjustment);
expr = apply_adjustment(cx, self, expr, adjustment);
}
// Next, wrap this up in the expr's scope.
expr = Expr {
temp_lifetime,
ty: expr.ty,
span: self.span,
kind: ExprKind::Scope {
region_scope: expr_scope,
value: expr.to_ref(),
lint_level: LintLevel::Explicit(self.hir_id),
},
};
// Finally, create a destruction scope, if any.
if let Some(region_scope) =
cx.region_scope_tree.opt_destruction_scope(self.hir_id.local_id) {
expr = Expr {
temp_lifetime,
ty: expr.ty,
span: self.span,
kind: ExprKind::Scope {
region_scope,
value: expr.to_ref(),
lint_level: LintLevel::Inherited,
},
};
}
// OK, all done!
expr
}
}
fn apply_adjustment<'a, 'tcx>(
cx: &mut Cx<'a, 'tcx>,
hir_expr: &'tcx hir::Expr,
mut expr: Expr<'tcx>,
adjustment: &Adjustment<'tcx>
) -> Expr<'tcx> {
let Expr { temp_lifetime, mut span, .. } = expr;
// Adjust the span from the block, to the last expression of the
// block. This is a better span when returning a mutable reference
// with too short a lifetime. The error message will use the span
// from the assignment to the return place, which should only point
// at the returned value, not the entire function body.
//
// fn return_short_lived<'a>(x: &'a mut i32) -> &'static mut i32 {
// x
// // ^ error message points at this expression.
// }
let mut adjust_span = |expr: &mut Expr<'tcx>| {
if let ExprKind::Block { body } = expr.kind {
if let Some(ref last_expr) = body.expr {
span = last_expr.span;
expr.span = span;
}
}
};
let kind = match adjustment.kind {
Adjust::Pointer(PointerCast::Unsize) => {
adjust_span(&mut expr);
ExprKind::Pointer { cast: PointerCast::Unsize, source: expr.to_ref() }
}
Adjust::Pointer(cast) => {
ExprKind::Pointer { cast, source: expr.to_ref() }
}
Adjust::NeverToAny => {
ExprKind::NeverToAny { source: expr.to_ref() }
}
Adjust::Deref(None) => {
adjust_span(&mut expr);
ExprKind::Deref { arg: expr.to_ref() }
}
Adjust::Deref(Some(deref)) => {
// We don't need to do call adjust_span here since
// deref coercions always start with a built-in deref.
let call = deref.method_call(cx.tcx(), expr.ty);
expr = Expr {
temp_lifetime,
ty: cx.tcx.mk_ref(deref.region,
ty::TypeAndMut {
ty: expr.ty,
mutbl: deref.mutbl,
}),
span,
kind: ExprKind::Borrow {
borrow_kind: deref.mutbl.to_borrow_kind(),
arg: expr.to_ref(),
},
};
overloaded_place(cx, hir_expr, adjustment.target, Some(call), vec![expr.to_ref()])
}
Adjust::Borrow(AutoBorrow::Ref(_, m)) => {
ExprKind::Borrow {
borrow_kind: m.to_borrow_kind(),
arg: expr.to_ref(),
}
}
Adjust::Borrow(AutoBorrow::RawPtr(m)) => {
// Convert this to a suitable `&foo` and
// then an unsafe coercion.
expr = Expr {
temp_lifetime,
ty: cx.tcx.mk_ref(cx.tcx.lifetimes.re_erased,
ty::TypeAndMut {
ty: expr.ty,
mutbl: m,
}),
span,
kind: ExprKind::Borrow {
borrow_kind: m.to_borrow_kind(),
arg: expr.to_ref(),
},
};
let cast_expr = Expr {
temp_lifetime,
ty: adjustment.target,
span,
kind: ExprKind::Cast { source: expr.to_ref() }
};
// To ensure that both implicit and explicit coercions are
// handled the same way, we insert an extra layer of indirection here.
// For explicit casts (e.g., 'foo as *const T'), the source of the 'Use'
// will be an ExprKind::Hair with the appropriate cast expression. Here,
// we make our Use source the generated Cast from the original coercion.
//
// In both cases, this outer 'Use' ensures that the inner 'Cast' is handled by
// as_operand, not by as_rvalue - causing the cast result to be stored in a temporary.
// Ordinary, this is identical to using the cast directly as an rvalue. However, if the
// source of the cast was previously borrowed as mutable, storing the cast in a
// temporary gives the source a chance to expire before the cast is used. For
// structs with a self-referential *mut ptr, this allows assignment to work as
// expected.
//
// For example, consider the type 'struct Foo { field: *mut Foo }',
// The method 'fn bar(&mut self) { self.field = self }'
// triggers a coercion from '&mut self' to '*mut self'. In order
// for the assignment to be valid, the implicit borrow
// of 'self' involved in the coercion needs to end before the local
// containing the '*mut T' is assigned to 'self.field' - otherwise,
// we end up trying to assign to 'self.field' while we have another mutable borrow
// active.
//
// We only need to worry about this kind of thing for coercions from refs to ptrs,
// since they get rid of a borrow implicitly.
ExprKind::Use { source: cast_expr.to_ref() }
}
};
Expr {
temp_lifetime,
ty: adjustment.target,
span,
kind,
}
}
fn make_mirror_unadjusted<'a, 'tcx>(
cx: &mut Cx<'a, 'tcx>,
expr: &'tcx hir::Expr,
) -> Expr<'tcx> {
let expr_ty = cx.tables().expr_ty(expr);
let temp_lifetime = cx.region_scope_tree.temporary_scope(expr.hir_id.local_id);
let kind = match expr.node {
// Here comes the interesting stuff:
hir::ExprKind::MethodCall(_, method_span, ref args) => {
// Rewrite a.b(c) into UFCS form like Trait::b(a, c)
let expr = method_callee(cx, expr, method_span,None);
let args = args.iter()
.map(|e| e.to_ref())
.collect();
ExprKind::Call {
ty: expr.ty,
fun: expr.to_ref(),
args,
from_hir_call: true,
}
}
hir::ExprKind::Call(ref fun, ref args) => {
if cx.tables().is_method_call(expr) {
// The callee is something implementing Fn, FnMut, or FnOnce.
// Find the actual method implementation being called and
// build the appropriate UFCS call expression with the
// callee-object as expr parameter.
// rewrite f(u, v) into FnOnce::call_once(f, (u, v))
let method = method_callee(cx, expr, fun.span,None);
let arg_tys = args.iter().map(|e| cx.tables().expr_ty_adjusted(e));
let tupled_args = Expr {
ty: cx.tcx.mk_tup(arg_tys),
temp_lifetime,
span: expr.span,
kind: ExprKind::Tuple { fields: args.iter().map(ToRef::to_ref).collect() },
};
ExprKind::Call {
ty: method.ty,
fun: method.to_ref(),
args: vec![fun.to_ref(), tupled_args.to_ref()],
from_hir_call: true,
}
} else {
let adt_data = if let hir::ExprKind::Path(hir::QPath::Resolved(_, ref path)) =
fun.node
{
// Tuple-like ADTs are represented as ExprKind::Call. We convert them here.
expr_ty.ty_adt_def().and_then(|adt_def| {
match path.res {
Res::Def(DefKind::Ctor(_, CtorKind::Fn), ctor_id) =>
Some((adt_def, adt_def.variant_index_with_ctor_id(ctor_id))),
Res::SelfCtor(..) => Some((adt_def, VariantIdx::new(0))),
_ => None,
}
})
} else {
None
};
if let Some((adt_def, index)) = adt_data {
let substs = cx.tables().node_substs(fun.hir_id);
let user_provided_types = cx.tables().user_provided_types();
let user_ty = user_provided_types.get(fun.hir_id)
.map(|u_ty| *u_ty)
.map(|mut u_ty| {
if let UserType::TypeOf(ref mut did, _) = &mut u_ty.value {
*did = adt_def.did;
}
u_ty
});
debug!("make_mirror_unadjusted: (call) user_ty={:?}", user_ty);
let field_refs = args.iter()
.enumerate()
.map(|(idx, e)| {
FieldExprRef {
name: Field::new(idx),
expr: e.to_ref(),
}
})
.collect();
ExprKind::Adt {
adt_def,
substs,
variant_index: index,
fields: field_refs,
user_ty,
base: None,
}
} else {
ExprKind::Call {
ty: cx.tables().node_type(fun.hir_id),
fun: fun.to_ref(),
args: args.to_ref(),
from_hir_call: true,
}
}
}
}
hir::ExprKind::AddrOf(mutbl, ref expr) => {
ExprKind::Borrow {
borrow_kind: mutbl.to_borrow_kind(),
arg: expr.to_ref(),
}
}
hir::ExprKind::Block(ref blk, _) => ExprKind::Block { body: &blk },
hir::ExprKind::Assign(ref lhs, ref rhs) => {
ExprKind::Assign {
lhs: lhs.to_ref(),
rhs: rhs.to_ref(),
}
}
hir::ExprKind::AssignOp(op, ref lhs, ref rhs) => {
if cx.tables().is_method_call(expr) {
overloaded_operator(cx, expr, vec![lhs.to_ref(), rhs.to_ref()])
} else {
ExprKind::AssignOp {
op: bin_op(op.node),
lhs: lhs.to_ref(),
rhs: rhs.to_ref(),
}
}
}
hir::ExprKind::Lit(ref lit) => ExprKind::Literal {
literal: cx.const_eval_literal(&lit.node, expr_ty, lit.span, false),
user_ty: None,
},
hir::ExprKind::Binary(op, ref lhs, ref rhs) => {
if cx.tables().is_method_call(expr) {
overloaded_operator(cx, expr, vec![lhs.to_ref(), rhs.to_ref()])
} else {
// FIXME overflow
match (op.node, cx.constness) {
// FIXME(eddyb) use logical ops in constants when
// they can handle that kind of control-flow.
(hir::BinOpKind::And, hir::Constness::Const) => {
cx.control_flow_destroyed.push((
op.span,
"`&&` operator".into(),
));
ExprKind::Binary {
op: BinOp::BitAnd,
lhs: lhs.to_ref(),
rhs: rhs.to_ref(),
}
}
(hir::BinOpKind::Or, hir::Constness::Const) => {
cx.control_flow_destroyed.push((
op.span,
"`||` operator".into(),
));
ExprKind::Binary {
op: BinOp::BitOr,
lhs: lhs.to_ref(),
rhs: rhs.to_ref(),
}
}
(hir::BinOpKind::And, hir::Constness::NotConst) => {
ExprKind::LogicalOp {
op: LogicalOp::And,
lhs: lhs.to_ref(),
rhs: rhs.to_ref(),
}
}
(hir::BinOpKind::Or, hir::Constness::NotConst) => {
ExprKind::LogicalOp {
op: LogicalOp::Or,
lhs: lhs.to_ref(),
rhs: rhs.to_ref(),
}
}
_ => {
let op = bin_op(op.node);
ExprKind::Binary {
op,
lhs: lhs.to_ref(),
rhs: rhs.to_ref(),
}
}
}
}
}
hir::ExprKind::Index(ref lhs, ref index) => {
if cx.tables().is_method_call(expr) {
overloaded_place(cx, expr, expr_ty, None, vec![lhs.to_ref(), index.to_ref()])
} else {
ExprKind::Index {
lhs: lhs.to_ref(),
index: index.to_ref(),
}
}
}
hir::ExprKind::Unary(hir::UnOp::UnDeref, ref arg) => {
if cx.tables().is_method_call(expr) {
overloaded_place(cx, expr, expr_ty, None, vec![arg.to_ref()])
} else {
ExprKind::Deref { arg: arg.to_ref() }
}
}
hir::ExprKind::Unary(hir::UnOp::UnNot, ref arg) => {
if cx.tables().is_method_call(expr) {
overloaded_operator(cx, expr, vec![arg.to_ref()])
} else {
ExprKind::Unary {
op: UnOp::Not,
arg: arg.to_ref(),
}
}
}
hir::ExprKind::Unary(hir::UnOp::UnNeg, ref arg) => {
if cx.tables().is_method_call(expr) {
overloaded_operator(cx, expr, vec![arg.to_ref()])
} else {
if let hir::ExprKind::Lit(ref lit) = arg.node {
ExprKind::Literal {
literal: cx.const_eval_literal(&lit.node, expr_ty, lit.span, true),
user_ty: None,
}
} else {
ExprKind::Unary {
op: UnOp::Neg,
arg: arg.to_ref(),
}
}
}
}
hir::ExprKind::Struct(ref qpath, ref fields, ref base) => {
match expr_ty.sty {
ty::Adt(adt, substs) => {
match adt.adt_kind() {
AdtKind::Struct | AdtKind::Union => {
let user_provided_types = cx.tables().user_provided_types();
let user_ty = user_provided_types.get(expr.hir_id).map(|u_ty| *u_ty);
debug!("make_mirror_unadjusted: (struct/union) user_ty={:?}", user_ty);
ExprKind::Adt {
adt_def: adt,
variant_index: VariantIdx::new(0),
substs,
user_ty,
fields: field_refs(cx, fields),
base: base.as_ref().map(|base| {
FruInfo {
base: base.to_ref(),
field_types: cx.tables()
.fru_field_types()[expr.hir_id]
.clone(),
}
}),
}
}
AdtKind::Enum => {
let res = cx.tables().qpath_res(qpath, expr.hir_id);
match res {
Res::Def(DefKind::Variant, variant_id) => {
assert!(base.is_none());
let index = adt.variant_index_with_id(variant_id);
let user_provided_types = cx.tables().user_provided_types();
let user_ty = user_provided_types.get(expr.hir_id)
.map(|u_ty| *u_ty);
debug!(
"make_mirror_unadjusted: (variant) user_ty={:?}",
user_ty
);
ExprKind::Adt {
adt_def: adt,
variant_index: index,
substs,
user_ty,
fields: field_refs(cx, fields),
base: None,
}
}
_ => {
span_bug!(expr.span, "unexpected res: {:?}", res);
}
}
}
}
}
_ => {
span_bug!(expr.span,
"unexpected type for struct literal: {:?}",
expr_ty);
}
}
}
hir::ExprKind::Closure(..) => {
let closure_ty = cx.tables().expr_ty(expr);
let (def_id, substs, movability) = match closure_ty.sty {
ty::Closure(def_id, substs) => (def_id, UpvarSubsts::Closure(substs), None),
ty::Generator(def_id, substs, movability) => {
(def_id, UpvarSubsts::Generator(substs), Some(movability))
}
_ => {
span_bug!(expr.span, "closure expr w/o closure type: {:?}", closure_ty);
}
};
let upvars = cx.tcx.upvars(def_id).iter()
.flat_map(|upvars| upvars.iter())
.zip(substs.upvar_tys(def_id, cx.tcx))
.map(|((&var_hir_id, _), ty)| capture_upvar(cx, expr, var_hir_id, ty))
.collect();
ExprKind::Closure {
closure_id: def_id,
substs,
upvars,
movability,
}
}
hir::ExprKind::Path(ref qpath) => {
let res = cx.tables().qpath_res(qpath, expr.hir_id);
convert_path_expr(cx, expr, res)
}
hir::ExprKind::InlineAsm(ref asm, ref outputs, ref inputs) => {
ExprKind::InlineAsm {
asm,
outputs: outputs.to_ref(),
inputs: inputs.to_ref(),
}
}
// Now comes the rote stuff:
hir::ExprKind::Repeat(ref v, ref count) => {
let def_id = cx.tcx.hir().local_def_id(count.hir_id);
let substs = InternalSubsts::identity_for_item(cx.tcx.global_tcx(), def_id);
let instance = ty::Instance::resolve(
cx.tcx.global_tcx(),
cx.param_env,
def_id,
substs,
).unwrap();
let global_id = GlobalId {
instance,
promoted: None
};
let span = cx.tcx.def_span(def_id);
let count = match cx.tcx.at(span).const_eval(cx.param_env.and(global_id)) {
Ok(cv) => cv.unwrap_usize(cx.tcx),
Err(ErrorHandled::Reported) => 0,
Err(ErrorHandled::TooGeneric) => {
cx.tcx.sess.span_err(span, "array lengths can't depend on generic parameters");
0
},
};
ExprKind::Repeat {
value: v.to_ref(),
count,
}
}
hir::ExprKind::Ret(ref v) => ExprKind::Return { value: v.to_ref() },
hir::ExprKind::Break(dest, ref value) => {
match dest.target_id {
Ok(target_id) => ExprKind::Break {
label: region::Scope {
id: target_id.local_id,
data: region::ScopeData::Node
},
value: value.to_ref(),
},
Err(err) => bug!("invalid loop id for break: {}", err)
}
}
hir::ExprKind::Continue(dest) => {
match dest.target_id {
Ok(loop_id) => ExprKind::Continue {
label: region::Scope {
id: loop_id.local_id,
data: region::ScopeData::Node
},
},
Err(err) => bug!("invalid loop id for continue: {}", err)
}
}
hir::ExprKind::Match(ref discr, ref arms, _) => {
ExprKind::Match {
scrutinee: discr.to_ref(),
arms: arms.iter().map(|a| convert_arm(cx, a)).collect(),
}
}
hir::ExprKind::Loop(ref body, _, _) => {
ExprKind::Loop {
body: block::to_expr_ref(cx, body),
}
}
hir::ExprKind::Field(ref source, ..) => {
ExprKind::Field {
lhs: source.to_ref(),
name: Field::new(cx.tcx.field_index(expr.hir_id, cx.tables)),
}
}
hir::ExprKind::Cast(ref source, ref cast_ty) => {
// Check for a user-given type annotation on this `cast`
let user_provided_types = cx.tables.user_provided_types();
let user_ty = user_provided_types.get(cast_ty.hir_id);
debug!(
"cast({:?}) has ty w/ hir_id {:?} and user provided ty {:?}",
expr,
cast_ty.hir_id,
user_ty,
);
// Check to see if this cast is a "coercion cast", where the cast is actually done
// using a coercion (or is a no-op).
let cast = if cx.tables().is_coercion_cast(source.hir_id) {
// Convert the lexpr to a vexpr.
ExprKind::Use { source: source.to_ref() }
} else {
// check whether this is casting an enum variant discriminant
// to prevent cycles, we refer to the discriminant initializer
// which is always an integer and thus doesn't need to know the
// enum's layout (or its tag type) to compute it during const eval
// Example:
// enum Foo {
// A,
// B = A as isize + 4,
// }
// The correct solution would be to add symbolic computations to miri,
// so we wouldn't have to compute and store the actual value
let var = if let hir::ExprKind::Path(ref qpath) = source.node {
let res = cx.tables().qpath_res(qpath, source.hir_id);
cx
.tables()
.node_type(source.hir_id)
.ty_adt_def()
.and_then(|adt_def| {
match res {
Res::Def(
DefKind::Ctor(CtorOf::Variant, CtorKind::Const),
variant_ctor_id,
) => {
let idx = adt_def.variant_index_with_ctor_id(variant_ctor_id);
let (d, o) = adt_def.discriminant_def_for_variant(idx);
use rustc::ty::util::IntTypeExt;
let ty = adt_def.repr.discr_type();
let ty = ty.to_ty(cx.tcx());
Some((d, o, ty))
}
_ => None,
}
})
} else {
None
};
let source = if let Some((did, offset, var_ty)) = var {
let mk_const = |literal| Expr {
temp_lifetime,
ty: var_ty,
span: expr.span,
kind: ExprKind::Literal {
literal,
user_ty: None
},
}.to_ref();
let offset = mk_const(ty::Const::from_bits(
cx.tcx,
offset as u128,
cx.param_env.and(var_ty),
));
match did {
Some(did) => {
// in case we are offsetting from a computed discriminant
// and not the beginning of discriminants (which is always `0`)
let substs = InternalSubsts::identity_for_item(cx.tcx(), did);
let lhs = mk_const(cx.tcx().mk_const(ty::Const {
val: ConstValue::Unevaluated(did, substs),
ty: var_ty,
}));
let bin = ExprKind::Binary {
op: BinOp::Add,
lhs,
rhs: offset,
};
Expr {
temp_lifetime,
ty: var_ty,
span: expr.span,
kind: bin,
}.to_ref()
},
None => offset,
}
} else {
source.to_ref()
};
ExprKind::Cast { source }
};
if let Some(user_ty) = user_ty {
// NOTE: Creating a new Expr and wrapping a Cast inside of it may be
// inefficient, revisit this when performance becomes an issue.
let cast_expr = Expr {
temp_lifetime,
ty: expr_ty,
span: expr.span,
kind: cast,
};
debug!("make_mirror_unadjusted: (cast) user_ty={:?}", user_ty);
ExprKind::ValueTypeAscription {
source: cast_expr.to_ref(),
user_ty: Some(*user_ty),
}
} else {
cast
}
}
hir::ExprKind::Type(ref source, ref ty) => {
let user_provided_types = cx.tables.user_provided_types();
let user_ty = user_provided_types.get(ty.hir_id).map(|u_ty| *u_ty);
debug!("make_mirror_unadjusted: (type) user_ty={:?}", user_ty);
if source.is_place_expr() {
ExprKind::PlaceTypeAscription {
source: source.to_ref(),
user_ty,
}
} else {
ExprKind::ValueTypeAscription {
source: source.to_ref(),
user_ty,
}
}
}
hir::ExprKind::DropTemps(ref source) => {
ExprKind::Use { source: source.to_ref() }
}
hir::ExprKind::Box(ref value) => {
ExprKind::Box {
value: value.to_ref(),
}
}
hir::ExprKind::Array(ref fields) => ExprKind::Array { fields: fields.to_ref() },
hir::ExprKind::Tup(ref fields) => ExprKind::Tuple { fields: fields.to_ref() },
hir::ExprKind::Yield(ref v, _) => ExprKind::Yield { value: v.to_ref() },
hir::ExprKind::Err => unreachable!(),
};
Expr {
temp_lifetime,
ty: expr_ty,
span: expr.span,
kind,
}
}
fn user_substs_applied_to_res(
cx: &mut Cx<'a, 'tcx>,
hir_id: hir::HirId,
res: Res,
) -> Option<ty::CanonicalUserType<'tcx>> {
debug!("user_substs_applied_to_res: res={:?}", res);
let user_provided_type = match res {
// A reference to something callable -- e.g., a fn, method, or
// a tuple-struct or tuple-variant. This has the type of a
// `Fn` but with the user-given substitutions.
Res::Def(DefKind::Fn, _) |
Res::Def(DefKind::Method, _) |
Res::Def(DefKind::Ctor(_, CtorKind::Fn), _) |
Res::Def(DefKind::Const, _) |
Res::Def(DefKind::AssocConst, _) =>
cx.tables().user_provided_types().get(hir_id).map(|u_ty| *u_ty),
// A unit struct/variant which is used as a value (e.g.,
// `None`). This has the type of the enum/struct that defines
// this variant -- but with the substitutions given by the
// user.
Res::Def(DefKind::Ctor(_, CtorKind::Const), _) =>
cx.user_substs_applied_to_ty_of_hir_id(hir_id),
// `Self` is used in expression as a tuple struct constructor or an unit struct constructor
Res::SelfCtor(_) =>
cx.user_substs_applied_to_ty_of_hir_id(hir_id),
_ =>
bug!("user_substs_applied_to_res: unexpected res {:?} at {:?}", res, hir_id)
};
debug!("user_substs_applied_to_res: user_provided_type={:?}", user_provided_type);
user_provided_type
}
fn method_callee<'a, 'tcx>(
cx: &mut Cx<'a, 'tcx>,
expr: &hir::Expr,
span: Span,
overloaded_callee: Option<(DefId, SubstsRef<'tcx>)>,
) -> Expr<'tcx> {
let temp_lifetime = cx.region_scope_tree.temporary_scope(expr.hir_id.local_id);
let (def_id, substs, user_ty) = match overloaded_callee {
Some((def_id, substs)) => (def_id, substs, None),
None => {
let (kind, def_id) = cx.tables().type_dependent_def(expr.hir_id)
.unwrap_or_else(|| {
span_bug!(expr.span, "no type-dependent def for method callee")
});
let user_ty = user_substs_applied_to_res(cx, expr.hir_id, Res::Def(kind, def_id));
debug!("method_callee: user_ty={:?}", user_ty);
(def_id, cx.tables().node_substs(expr.hir_id), user_ty)
}
};
let ty = cx.tcx().mk_fn_def(def_id, substs);
Expr {
temp_lifetime,
ty,
span,
kind: ExprKind::Literal {
literal: ty::Const::zero_sized(cx.tcx(), ty),
user_ty,
},
}
}
trait ToBorrowKind { fn to_borrow_kind(&self) -> BorrowKind; }
impl ToBorrowKind for AutoBorrowMutability {
fn to_borrow_kind(&self) -> BorrowKind {
use rustc::ty::adjustment::AllowTwoPhase;
match *self {
AutoBorrowMutability::Mutable { allow_two_phase_borrow } =>
BorrowKind::Mut { allow_two_phase_borrow: match allow_two_phase_borrow {
AllowTwoPhase::Yes => true,
AllowTwoPhase::No => false
}},
AutoBorrowMutability::Immutable =>
BorrowKind::Shared,
}
}
}
impl ToBorrowKind for hir::Mutability {
fn to_borrow_kind(&self) -> BorrowKind {
match *self {
hir::MutMutable => BorrowKind::Mut { allow_two_phase_borrow: false },
hir::MutImmutable => BorrowKind::Shared,
}
}
}
fn convert_arm<'a, 'tcx>(cx: &mut Cx<'a, 'tcx>, arm: &'tcx hir::Arm) -> Arm<'tcx> {
Arm {
patterns: arm.pats.iter().map(|p| cx.pattern_from_hir(p)).collect(),
guard: match arm.guard {
Some(hir::Guard::If(ref e)) => Some(Guard::If(e.to_ref())),
_ => None,
},
body: arm.body.to_ref(),
lint_level: LintLevel::Explicit(arm.hir_id),
scope: region::Scope {
id: arm.hir_id.local_id,
data: region::ScopeData::Node
},
span: arm.span,
}
}
fn convert_path_expr<'a, 'tcx>(
cx: &mut Cx<'a, 'tcx>,
expr: &'tcx hir::Expr,
res: Res,
) -> ExprKind<'tcx> {
let substs = cx.tables().node_substs(expr.hir_id);
match res {
// A regular function, constructor function or a constant.
Res::Def(DefKind::Fn, _) |
Res::Def(DefKind::Method, _) |
Res::Def(DefKind::Ctor(_, CtorKind::Fn), _) |
Res::SelfCtor(..) => {
let user_ty = user_substs_applied_to_res(cx, expr.hir_id, res);
debug!("convert_path_expr: user_ty={:?}", user_ty);
ExprKind::Literal {
literal: ty::Const::zero_sized(
cx.tcx,
cx.tables().node_type(expr.hir_id),
),
user_ty,
}
}
Res::Def(DefKind::ConstParam, def_id) => {
let hir_id = cx.tcx.hir().as_local_hir_id(def_id).unwrap();
let item_id = cx.tcx.hir().get_parent_node(hir_id);
let item_def_id = cx.tcx.hir().local_def_id(item_id);
let generics = cx.tcx.generics_of(item_def_id);
let local_def_id = cx.tcx.hir().local_def_id(hir_id);
let index = generics.param_def_id_to_index[&local_def_id];
let name = cx.tcx.hir().name(hir_id).as_interned_str();
let val = ConstValue::Param(ty::ParamConst::new(index, name));
ExprKind::Literal {
literal: cx.tcx.mk_const(
ty::Const {
val,
ty: cx.tables().node_type(expr.hir_id),
}
),
user_ty: None,
}
}
Res::Def(DefKind::Const, def_id) |
Res::Def(DefKind::AssocConst, def_id) => {
let user_ty = user_substs_applied_to_res(cx, expr.hir_id, res);
debug!("convert_path_expr: (const) user_ty={:?}", user_ty);
ExprKind::Literal {
literal: cx.tcx.mk_const(ty::Const {
val: ConstValue::Unevaluated(def_id, substs),
ty: cx.tcx.type_of(def_id),
}),
user_ty,
}
},
Res::Def(DefKind::Ctor(_, CtorKind::Const), def_id) => {
let user_provided_types = cx.tables.user_provided_types();
let user_provided_type = user_provided_types.get(expr.hir_id).map(|u_ty| *u_ty);
debug!("convert_path_expr: user_provided_type={:?}", user_provided_type);
let ty = cx.tables().node_type(expr.hir_id);
match ty.sty {
// A unit struct/variant which is used as a value.
// We return a completely different ExprKind here to account for this special case.
ty::Adt(adt_def, substs) => {
ExprKind::Adt {
adt_def,
variant_index: adt_def.variant_index_with_ctor_id(def_id),
substs,
user_ty: user_provided_type,
fields: vec![],
base: None,
}
}
_ => bug!("unexpected ty: {:?}", ty),
}
}
Res::Def(DefKind::Static, id) => ExprKind::StaticRef { id },
Res::Local(var_hir_id) => convert_var(cx, expr, var_hir_id),
_ => span_bug!(expr.span, "res `{:?}` not yet implemented", res),
}
}
fn convert_var(
cx: &mut Cx<'_, 'tcx>,
expr: &'tcx hir::Expr,
var_hir_id: hir::HirId,
) -> ExprKind<'tcx> {
let upvar_index = cx.tables().upvar_list.get(&cx.body_owner)
.and_then(|upvars| upvars.get_full(&var_hir_id).map(|(i, _, _)| i));
debug!("convert_var({:?}): upvar_index={:?}, body_owner={:?}",
var_hir_id, upvar_index, cx.body_owner);
let temp_lifetime = cx.region_scope_tree.temporary_scope(expr.hir_id.local_id);
match upvar_index {
None => ExprKind::VarRef { id: var_hir_id },
Some(upvar_index) => {
let closure_def_id = cx.body_owner;
let upvar_id = ty::UpvarId {
var_path: ty::UpvarPath {hir_id: var_hir_id},
closure_expr_id: LocalDefId::from_def_id(closure_def_id),
};
let var_ty = cx.tables().node_type(var_hir_id);
// FIXME free regions in closures are not right
let closure_ty = cx.tables().node_type(
cx.tcx.hir().local_def_id_to_hir_id(upvar_id.closure_expr_id),
);
// FIXME we're just hard-coding the idea that the
// signature will be &self or &mut self and hence will
// have a bound region with number 0
let region = ty::ReFree(ty::FreeRegion {
scope: closure_def_id,
bound_region: ty::BoundRegion::BrAnon(0),
});
let region = cx.tcx.mk_region(region);
let self_expr = if let ty::Closure(_, closure_substs) = closure_ty.sty {
match cx.infcx.closure_kind(closure_def_id, closure_substs).unwrap() {
ty::ClosureKind::Fn => {
let ref_closure_ty = cx.tcx.mk_ref(region,
ty::TypeAndMut {
ty: closure_ty,
mutbl: hir::MutImmutable,
});
Expr {
ty: closure_ty,
temp_lifetime: temp_lifetime,
span: expr.span,
kind: ExprKind::Deref {
arg: Expr {
ty: ref_closure_ty,
temp_lifetime,
span: expr.span,
kind: ExprKind::SelfRef,
}
.to_ref(),
},
}
}
ty::ClosureKind::FnMut => {
let ref_closure_ty = cx.tcx.mk_ref(region,
ty::TypeAndMut {
ty: closure_ty,
mutbl: hir::MutMutable,
});
Expr {
ty: closure_ty,
temp_lifetime,
span: expr.span,
kind: ExprKind::Deref {
arg: Expr {
ty: ref_closure_ty,
temp_lifetime,
span: expr.span,
kind: ExprKind::SelfRef,
}.to_ref(),
},
}
}
ty::ClosureKind::FnOnce => {
Expr {
ty: closure_ty,
temp_lifetime,
span: expr.span,
kind: ExprKind::SelfRef,
}
}
}
} else {
Expr {
ty: closure_ty,
temp_lifetime,
span: expr.span,
kind: ExprKind::SelfRef,
}
};
// at this point we have `self.n`, which loads up the upvar
let field_kind = ExprKind::Field {
lhs: self_expr.to_ref(),
name: Field::new(upvar_index),
};
// ...but the upvar might be an `&T` or `&mut T` capture, at which
// point we need an implicit deref
match cx.tables().upvar_capture(upvar_id) {
ty::UpvarCapture::ByValue => field_kind,
ty::UpvarCapture::ByRef(borrow) => {
ExprKind::Deref {
arg: Expr {
temp_lifetime,
ty: cx.tcx.mk_ref(borrow.region,
ty::TypeAndMut {
ty: var_ty,
mutbl: borrow.kind.to_mutbl_lossy(),
}),
span: expr.span,
kind: field_kind,
}.to_ref(),
}
}
}
}
}
}
fn bin_op(op: hir::BinOpKind) -> BinOp {
match op {
hir::BinOpKind::Add => BinOp::Add,
hir::BinOpKind::Sub => BinOp::Sub,
hir::BinOpKind::Mul => BinOp::Mul,
hir::BinOpKind::Div => BinOp::Div,
hir::BinOpKind::Rem => BinOp::Rem,
hir::BinOpKind::BitXor => BinOp::BitXor,
hir::BinOpKind::BitAnd => BinOp::BitAnd,
hir::BinOpKind::BitOr => BinOp::BitOr,
hir::BinOpKind::Shl => BinOp::Shl,
hir::BinOpKind::Shr => BinOp::Shr,
hir::BinOpKind::Eq => BinOp::Eq,
hir::BinOpKind::Lt => BinOp::Lt,
hir::BinOpKind::Le => BinOp::Le,
hir::BinOpKind::Ne => BinOp::Ne,
hir::BinOpKind::Ge => BinOp::Ge,
hir::BinOpKind::Gt => BinOp::Gt,
_ => bug!("no equivalent for ast binop {:?}", op),
}
}
fn overloaded_operator<'a, 'tcx>(
cx: &mut Cx<'a, 'tcx>,
expr: &'tcx hir::Expr,
args: Vec<ExprRef<'tcx>>
) -> ExprKind<'tcx> {
let fun = method_callee(cx, expr, expr.span, None);
ExprKind::Call {
ty: fun.ty,
fun: fun.to_ref(),
args,
from_hir_call: false,
}
}
fn overloaded_place<'a, 'tcx>(
cx: &mut Cx<'a, 'tcx>,
expr: &'tcx hir::Expr,
place_ty: Ty<'tcx>,
overloaded_callee: Option<(DefId, SubstsRef<'tcx>)>,
args: Vec<ExprRef<'tcx>>,
) -> ExprKind<'tcx> {
// For an overloaded *x or x[y] expression of type T, the method
// call returns an &T and we must add the deref so that the types
// line up (this is because `*x` and `x[y]` represent places):
let recv_ty = match args[0] {
ExprRef::Hair(e) => cx.tables().expr_ty_adjusted(e),
ExprRef::Mirror(ref e) => e.ty
};
// Reconstruct the output assuming it's a reference with the
// same region and mutability as the receiver. This holds for
// `Deref(Mut)::Deref(_mut)` and `Index(Mut)::index(_mut)`.
let (region, mutbl) = match recv_ty.sty {
ty::Ref(region, _, mutbl) => (region, mutbl),
_ => span_bug!(expr.span, "overloaded_place: receiver is not a reference"),
};
let ref_ty = cx.tcx.mk_ref(region, ty::TypeAndMut {
ty: place_ty,
mutbl,
});
// construct the complete expression `foo()` for the overloaded call,
// which will yield the &T type
let temp_lifetime = cx.region_scope_tree.temporary_scope(expr.hir_id.local_id);
let fun = method_callee(cx, expr, expr.span, overloaded_callee);
let ref_expr = Expr {
temp_lifetime,
ty: ref_ty,
span: expr.span,
kind: ExprKind::Call {
ty: fun.ty,
fun: fun.to_ref(),
args,
from_hir_call: false,
},
};
// construct and return a deref wrapper `*foo()`
ExprKind::Deref { arg: ref_expr.to_ref() }
}
fn capture_upvar<'tcx>(
cx: &mut Cx<'_, 'tcx>,
closure_expr: &'tcx hir::Expr,
var_hir_id: hir::HirId,
upvar_ty: Ty<'tcx>
) -> ExprRef<'tcx> {
let upvar_id = ty::UpvarId {
var_path: ty::UpvarPath { hir_id: var_hir_id },
closure_expr_id: cx.tcx.hir().local_def_id(closure_expr.hir_id).to_local(),
};
let upvar_capture = cx.tables().upvar_capture(upvar_id);
let temp_lifetime = cx.region_scope_tree.temporary_scope(closure_expr.hir_id.local_id);
let var_ty = cx.tables().node_type(var_hir_id);
let captured_var = Expr {
temp_lifetime,
ty: var_ty,
span: closure_expr.span,
kind: convert_var(cx, closure_expr, var_hir_id),
};
match upvar_capture {
ty::UpvarCapture::ByValue => captured_var.to_ref(),
ty::UpvarCapture::ByRef(upvar_borrow) => {
let borrow_kind = match upvar_borrow.kind {
ty::BorrowKind::ImmBorrow => BorrowKind::Shared,
ty::BorrowKind::UniqueImmBorrow => BorrowKind::Unique,
ty::BorrowKind::MutBorrow => BorrowKind::Mut { allow_two_phase_borrow: false }
};
Expr {
temp_lifetime,
ty: upvar_ty,
span: closure_expr.span,
kind: ExprKind::Borrow {
borrow_kind,
arg: captured_var.to_ref(),
},
}.to_ref()
}
}
}
/// Converts a list of named fields (i.e., for struct-like struct/enum ADTs) into FieldExprRef.
fn field_refs<'a, 'tcx>(
cx: &mut Cx<'a, 'tcx>,
fields: &'tcx [hir::Field]
) -> Vec<FieldExprRef<'tcx>> {
fields.iter()
.map(|field| {
FieldExprRef {
name: Field::new(cx.tcx.field_index(field.hir_id, cx.tables)),
expr: field.expr.to_ref(),
}
})
.collect()
}
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