| 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.eval_usize(cx.tcx, cx.param_env), |
| 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.top_pats_hack().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.tables().node_type(expr.hir_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() |
| } |
