mod regionck;
pub mod coercion;
pub mod demand;
+mod expr;
pub mod method;
mod upvar;
mod wfcheck;
use crate::astconv::{AstConv, PathSeg};
use errors::{Applicability, DiagnosticBuilder, DiagnosticId};
use rustc::hir::{self, ExprKind, GenericArg, ItemKind, Node, PatKind, QPath};
-use rustc::hir::def::{CtorOf, CtorKind, Res, DefKind};
+use rustc::hir::def::{CtorOf, Res, DefKind};
use rustc::hir::def_id::{CrateNum, DefId, LOCAL_CRATE};
use rustc::hir::intravisit::{self, Visitor, NestedVisitorMap};
use rustc::hir::itemlikevisit::ItemLikeVisitor;
+use rustc::hir::ptr::P;
use crate::middle::lang_items;
use crate::namespace::Namespace;
use rustc::infer::{self, InferCtxt, InferOk, InferResult};
use rustc::mir::interpret::{ConstValue, GlobalId};
use rustc::traits::{self, ObligationCause, ObligationCauseCode, TraitEngine};
use rustc::ty::{
- self, AdtKind, CanonicalUserType, Ty, TyCtxt, Const, GenericParamDefKind, Visibility,
+ self, AdtKind, CanonicalUserType, Ty, TyCtxt, Const, GenericParamDefKind,
ToPolyTraitRef, ToPredicate, RegionKind, UserType
};
use rustc::ty::adjustment::{
use syntax::ast;
use syntax::attr;
use syntax::feature_gate::{GateIssue, emit_feature_err};
-use syntax::ptr::P;
use syntax::source_map::{DUMMY_SP, original_sp};
-use syntax::symbol::{Symbol, LocalInternedString, kw, sym};
-use syntax::util::lev_distance::find_best_match_for_name;
+use syntax::symbol::{kw, sym};
use std::cell::{Cell, RefCell, Ref, RefMut};
use std::collections::hash_map::Entry;
use std::cmp;
-use std::fmt::Display;
use std::iter;
use std::mem::replace;
use std::ops::{self, Deref};
use crate::lint;
use crate::util::captures::Captures;
use crate::util::common::{ErrorReported, indenter};
-use crate::util::nodemap::{DefIdMap, DefIdSet, FxHashMap, FxHashSet, HirIdMap};
+use crate::util::nodemap::{DefIdMap, DefIdSet, FxHashSet, HirIdMap};
pub use self::Expectation::*;
use self::autoderef::Autoderef;
/// A wrapper for `InferCtxt`'s `in_progress_tables` field.
#[derive(Copy, Clone)]
-struct MaybeInProgressTables<'a, 'tcx: 'a> {
+struct MaybeInProgressTables<'a, 'tcx> {
maybe_tables: Option<&'a RefCell<ty::TypeckTables<'tcx>>>,
}
/// Here, the function `foo()` and the closure passed to
/// `bar()` will each have their own `FnCtxt`, but they will
/// share the inherited fields.
-pub struct Inherited<'a, 'tcx: 'a> {
+pub struct Inherited<'a, 'tcx> {
infcx: InferCtxt<'a, 'tcx>,
tables: MaybeInProgressTables<'a, 'tcx>,
deferred_cast_checks: RefCell<Vec<cast::CastCheck<'tcx>>>,
- deferred_generator_interiors: RefCell<Vec<(hir::BodyId, Ty<'tcx>)>>,
+ deferred_generator_interiors: RefCell<Vec<(hir::BodyId, Ty<'tcx>, hir::GeneratorKind)>>,
// Opaque types found in explicit return types and their
// associated fresh inference variable. Writeback resolves these
}
}
-pub struct FnCtxt<'a, 'tcx: 'a> {
+pub struct FnCtxt<'a, 'tcx> {
body_id: hir::HirId,
/// The parameter environment used for proving trait obligations
/// checking this function. On exit, if we find that *more* errors
/// have been reported, we will skip regionck and other work that
/// expects the types within the function to be consistent.
+ // FIXME(matthewjasper) This should not exist, and it's not correct
+ // if type checking is run in parallel.
err_count_on_creation: usize,
ret_coercion: Option<RefCell<DynamicCoerceMany<'tcx>>>,
fn new(infcx: InferCtxt<'a, 'tcx>, def_id: DefId) -> Self {
let tcx = infcx.tcx;
let item_id = tcx.hir().as_local_hir_id(def_id);
- let body_id = item_id.and_then(|id| tcx.hir().maybe_body_owned_by_by_hir_id(id));
+ let body_id = item_id.and_then(|id| tcx.hir().maybe_body_owned_by(id));
let implicit_region_bound = body_id.map(|body_id| {
let body = tcx.hir().body(body_id);
tcx.mk_region(ty::ReScope(region::Scope {
fn visit_impl_item(&mut self, _: &'tcx hir::ImplItem) { }
}
-pub fn check_wf_new<'tcx>(tcx: TyCtxt<'tcx>) -> Result<(), ErrorReported> {
- tcx.sess.track_errors(|| {
- let mut visit = wfcheck::CheckTypeWellFormedVisitor::new(tcx);
- tcx.hir().krate().par_visit_all_item_likes(&mut visit);
- })
+pub fn check_wf_new(tcx: TyCtxt<'_>) {
+ let mut visit = wfcheck::CheckTypeWellFormedVisitor::new(tcx);
+ tcx.hir().krate().par_visit_all_item_likes(&mut visit);
}
-fn check_mod_item_types<'tcx>(tcx: TyCtxt<'tcx>, module_def_id: DefId) {
+fn check_mod_item_types(tcx: TyCtxt<'_>, module_def_id: DefId) {
tcx.hir().visit_item_likes_in_module(module_def_id, &mut CheckItemTypesVisitor { tcx });
}
-fn typeck_item_bodies<'tcx>(tcx: TyCtxt<'tcx>, crate_num: CrateNum) {
+fn typeck_item_bodies(tcx: TyCtxt<'_>, crate_num: CrateNum) {
debug_assert!(crate_num == LOCAL_CRATE);
tcx.par_body_owners(|body_owner_def_id| {
tcx.ensure().typeck_tables_of(body_owner_def_id);
});
}
-fn check_item_well_formed<'tcx>(tcx: TyCtxt<'tcx>, def_id: DefId) {
+fn check_item_well_formed(tcx: TyCtxt<'_>, def_id: DefId) {
wfcheck::check_item_well_formed(tcx, def_id);
}
-fn check_trait_item_well_formed<'tcx>(tcx: TyCtxt<'tcx>, def_id: DefId) {
+fn check_trait_item_well_formed(tcx: TyCtxt<'_>, def_id: DefId) {
wfcheck::check_trait_item(tcx, def_id);
}
-fn check_impl_item_well_formed<'tcx>(tcx: TyCtxt<'tcx>, def_id: DefId) {
+fn check_impl_item_well_formed(tcx: TyCtxt<'_>, def_id: DefId) {
wfcheck::check_impl_item(tcx, def_id);
}
};
}
-fn adt_destructor<'tcx>(tcx: TyCtxt<'tcx>, def_id: DefId) -> Option<ty::Destructor> {
+fn adt_destructor(tcx: TyCtxt<'_>, def_id: DefId) -> Option<ty::Destructor> {
tcx.calculate_dtor(def_id, &mut dropck::check_drop_impl)
}
/// may not succeed. In some cases where this function returns `None`
/// (notably closures), `typeck_tables(def_id)` would wind up
/// redirecting to the owning function.
-fn primary_body_of<'tcx>(
- tcx: TyCtxt<'tcx>,
+fn primary_body_of(
+ tcx: TyCtxt<'_>,
id: hir::HirId,
-) -> Option<(hir::BodyId, Option<&'tcx hir::FnDecl>)> {
- match tcx.hir().get_by_hir_id(id) {
+) -> Option<(hir::BodyId, Option<&hir::FnDecl>)> {
+ match tcx.hir().get(id) {
Node::Item(item) => {
match item.node {
hir::ItemKind::Const(_, body) |
}
}
-fn has_typeck_tables<'tcx>(tcx: TyCtxt<'tcx>, def_id: DefId) -> bool {
+fn has_typeck_tables(tcx: TyCtxt<'_>, def_id: DefId) -> bool {
// Closures' tables come from their outermost function,
// as they are part of the same "inference environment".
let outer_def_id = tcx.closure_base_def_id(def_id);
primary_body_of(tcx, id).is_some()
}
-fn used_trait_imports<'tcx>(tcx: TyCtxt<'tcx>, def_id: DefId) -> &'tcx DefIdSet {
+fn used_trait_imports(tcx: TyCtxt<'_>, def_id: DefId) -> &DefIdSet {
&*tcx.typeck_tables_of(def_id).used_trait_imports
}
-fn typeck_tables_of<'tcx>(tcx: TyCtxt<'tcx>, def_id: DefId) -> &'tcx ty::TypeckTables<'tcx> {
+fn typeck_tables_of(tcx: TyCtxt<'_>, def_id: DefId) -> &ty::TypeckTables<'_> {
// Closures' tables come from their outermost function,
// as they are part of the same "inference environment".
let outer_def_id = tcx.closure_base_def_id(def_id);
}
let id = tcx.hir().as_local_hir_id(def_id).unwrap();
- let span = tcx.hir().span_by_hir_id(id);
+ let span = tcx.hir().span(id);
// Figure out what primary body this item has.
let (body_id, fn_decl) = primary_body_of(tcx, id).unwrap_or_else(|| {
let revealed_ty = if tcx.features().impl_trait_in_bindings {
fcx.instantiate_opaque_types_from_value(
id,
- &expected_type
+ &expected_type,
+ body.value.span,
)
} else {
expected_type
tables
}
-fn check_abi<'tcx>(tcx: TyCtxt<'tcx>, span: Span, abi: Abi) {
+fn check_abi(tcx: TyCtxt<'_>, span: Span, abi: Abi) {
if !tcx.sess.target.target.is_abi_supported(abi) {
struct_span_err!(tcx.sess, span, E0570,
"The ABI `{}` is not supported for the current target", abi).emit()
}
}
-struct GatherLocalsVisitor<'a, 'tcx: 'a> {
+struct GatherLocalsVisitor<'a, 'tcx> {
fcx: &'a FnCtxt<'a, 'tcx>,
parent_id: hir::HirId,
}
let revealed_ty = if self.fcx.tcx.features().impl_trait_in_bindings {
self.fcx.instantiate_opaque_types_from_value(
self.parent_id,
- &o_ty
+ &o_ty,
+ ty.span,
)
} else {
o_ty
if let PatKind::Binding(_, _, ident, _) = p.node {
let var_ty = self.assign(p.span, p.hir_id, None);
- let node_id = self.fcx.tcx.hir().hir_to_node_id(p.hir_id);
if !self.fcx.tcx.features().unsized_locals {
self.fcx.require_type_is_sized(var_ty, p.span,
- traits::VariableType(node_id));
+ traits::VariableType(p.hir_id));
}
debug!("Pattern binding {} is assigned to {} with type {:?}",
let declared_ret_ty = fn_sig.output();
fcx.require_type_is_sized(declared_ret_ty, decl.output.span(), traits::SizedReturnType);
- let revealed_ret_ty = fcx.instantiate_opaque_types_from_value(fn_id, &declared_ret_ty);
+ let revealed_ret_ty = fcx.instantiate_opaque_types_from_value(
+ fn_id,
+ &declared_ret_ty,
+ decl.output.span(),
+ );
fcx.ret_coercion = Some(RefCell::new(CoerceMany::new(revealed_ret_ty)));
fn_sig = fcx.tcx.mk_fn_sig(
fn_sig.inputs().iter().cloned(),
let span = body.value.span;
- if body.is_generator && can_be_generator.is_some() {
+ if body.generator_kind.is_some() && can_be_generator.is_some() {
let yield_ty = fcx.next_ty_var(TypeVariableOrigin {
kind: TypeVariableOriginKind::TypeInference,
span,
// We insert the deferred_generator_interiors entry after visiting the body.
// This ensures that all nested generators appear before the entry of this generator.
// resolve_generator_interiors relies on this property.
- let gen_ty = if can_be_generator.is_some() && body.is_generator {
+ let gen_ty = if let (Some(_), Some(gen_kind)) = (can_be_generator, body.generator_kind) {
let interior = fcx.next_ty_var(TypeVariableOrigin {
kind: TypeVariableOriginKind::MiscVariable,
span,
});
- fcx.deferred_generator_interiors.borrow_mut().push((body.id(), interior));
+ fcx.deferred_generator_interiors.borrow_mut().push((body.id(), interior, gen_kind));
Some(GeneratorTypes {
yield_ty: fcx.yield_ty.unwrap(),
interior,
}
let inputs = fn_sig.inputs();
- let span = fcx.tcx.hir().span_by_hir_id(fn_id);
+ let span = fcx.tcx.hir().span(fn_id);
if inputs.len() == 1 {
let arg_is_panic_info = match inputs[0].sty {
ty::Ref(region, ty, mutbl) => match ty.sty {
);
}
- if let Node::Item(item) = fcx.tcx.hir().get_by_hir_id(fn_id) {
+ if let Node::Item(item) = fcx.tcx.hir().get(fn_id) {
if let ItemKind::Fn(_, _, ref generics, _) = item.node {
if !generics.params.is_empty() {
fcx.tcx.sess.span_err(
}
let inputs = fn_sig.inputs();
- let span = fcx.tcx.hir().span_by_hir_id(fn_id);
+ let span = fcx.tcx.hir().span(fn_id);
if inputs.len() == 1 {
let arg_is_alloc_layout = match inputs[0].sty {
ty::Adt(ref adt, _) => {
);
}
- if let Node::Item(item) = fcx.tcx.hir().get_by_hir_id(fn_id) {
+ if let Node::Item(item) = fcx.tcx.hir().get(fn_id) {
if let ItemKind::Fn(_, _, ref generics, _) = item.node {
if !generics.params.is_empty() {
fcx.tcx.sess.span_err(
(fcx, gen_ty)
}
-fn check_struct<'tcx>(tcx: TyCtxt<'tcx>, id: hir::HirId, span: Span) {
+fn check_struct(tcx: TyCtxt<'_>, id: hir::HirId, span: Span) {
let def_id = tcx.hir().local_def_id_from_hir_id(id);
let def = tcx.adt_def(def_id);
def.destructor(tcx); // force the destructor to be evaluated
check_packed(tcx, span, def_id);
}
-fn check_union<'tcx>(tcx: TyCtxt<'tcx>, id: hir::HirId, span: Span) {
+fn check_union(tcx: TyCtxt<'_>, id: hir::HirId, span: Span) {
let def_id = tcx.hir().local_def_id_from_hir_id(id);
let def = tcx.adt_def(def_id);
def.destructor(tcx); // force the destructor to be evaluated
};
let param_env = ty::ParamEnv::reveal_all();
if let Ok(static_) = tcx.const_eval(param_env.and(cid)) {
- let alloc = if let ConstValue::ByRef(_, allocation) = static_.val {
- allocation
+ let alloc = if let ConstValue::ByRef { alloc, .. } = static_.val {
+ alloc
} else {
bug!("Matching on non-ByRef static")
};
}
}
-fn check_on_unimplemented<'tcx>(tcx: TyCtxt<'tcx>, trait_def_id: DefId, item: &hir::Item) {
+fn check_on_unimplemented(tcx: TyCtxt<'_>, trait_def_id: DefId, item: &hir::Item) {
let item_def_id = tcx.hir().local_def_id_from_hir_id(item.hir_id);
// an error would be reported if this fails.
let _ = traits::OnUnimplementedDirective::of_item(tcx, trait_def_id, item_def_id);
}
-fn report_forbidden_specialization<'tcx>(
- tcx: TyCtxt<'tcx>,
+fn report_forbidden_specialization(
+ tcx: TyCtxt<'_>,
impl_item: &hir::ImplItem,
parent_impl: DefId,
) {
/// Checks whether a type can be represented in memory. In particular, it
/// identifies types that contain themselves without indirection through a
/// pointer, which would mean their size is unbounded.
-fn check_representable<'tcx>(tcx: TyCtxt<'tcx>, sp: Span, item_def_id: DefId) -> bool {
+fn check_representable(tcx: TyCtxt<'_>, sp: Span, item_def_id: DefId) -> bool {
let rty = tcx.type_of(item_def_id);
// Check that it is possible to represent this type. This call identifies
return true;
}
-pub fn check_simd<'tcx>(tcx: TyCtxt<'tcx>, sp: Span, def_id: DefId) {
+pub fn check_simd(tcx: TyCtxt<'_>, sp: Span, def_id: DefId) {
let t = tcx.type_of(def_id);
if let ty::Adt(def, substs) = t.sty {
if def.is_struct() {
}
}
-fn check_packed<'tcx>(tcx: TyCtxt<'tcx>, sp: Span, def_id: DefId) {
+fn check_packed(tcx: TyCtxt<'_>, sp: Span, def_id: DefId) {
let repr = tcx.adt_def(def_id).repr;
if repr.packed() {
for attr in tcx.get_attrs(def_id).iter() {
}
}
-fn check_packed_inner<'tcx>(tcx: TyCtxt<'tcx>, def_id: DefId, stack: &mut Vec<DefId>) -> bool {
+fn check_packed_inner(tcx: TyCtxt<'_>, def_id: DefId, stack: &mut Vec<DefId>) -> bool {
let t = tcx.type_of(def_id);
if stack.contains(&def_id) {
debug!("check_packed_inner: {:?} is recursive", t);
false
}
-fn check_transparent<'tcx>(tcx: TyCtxt<'tcx>, sp: Span, def_id: DefId) {
+/// Emit an error when encountering more or less than one variant in a transparent enum.
+fn bad_variant_count<'tcx>(tcx: TyCtxt<'tcx>, adt: &'tcx ty::AdtDef, sp: Span, did: DefId) {
+ let variant_spans: Vec<_> = adt.variants.iter().map(|variant| {
+ tcx.hir().span_if_local(variant.def_id).unwrap()
+ }).collect();
+ let msg = format!(
+ "needs exactly one variant, but has {}",
+ adt.variants.len(),
+ );
+ let mut err = struct_span_err!(tcx.sess, sp, E0731, "transparent enum {}", msg);
+ err.span_label(sp, &msg);
+ if let &[ref start.., ref end] = &variant_spans[..] {
+ for variant_span in start {
+ err.span_label(*variant_span, "");
+ }
+ err.span_label(*end, &format!("too many variants in `{}`", tcx.def_path_str(did)));
+ }
+ err.emit();
+}
+
+/// Emit an error when encountering more or less than one non-zero-sized field in a transparent
+/// enum.
+fn bad_non_zero_sized_fields<'tcx>(
+ tcx: TyCtxt<'tcx>,
+ adt: &'tcx ty::AdtDef,
+ field_count: usize,
+ field_spans: impl Iterator<Item = Span>,
+ sp: Span,
+) {
+ let msg = format!("needs exactly one non-zero-sized field, but has {}", field_count);
+ let mut err = struct_span_err!(
+ tcx.sess,
+ sp,
+ E0690,
+ "{}transparent {} {}",
+ if adt.is_enum() { "the variant of a " } else { "" },
+ adt.descr(),
+ msg,
+ );
+ err.span_label(sp, &msg);
+ for sp in field_spans {
+ err.span_label(sp, "this field is non-zero-sized");
+ }
+ err.emit();
+}
+
+fn check_transparent(tcx: TyCtxt<'_>, sp: Span, def_id: DefId) {
let adt = tcx.adt_def(def_id);
if !adt.repr.transparent() {
return;
}
+ let sp = tcx.sess.source_map().def_span(sp);
if adt.is_enum() {
if !tcx.features().transparent_enums {
- emit_feature_err(&tcx.sess.parse_sess,
- sym::transparent_enums,
- sp,
- GateIssue::Language,
- "transparent enums are unstable");
+ emit_feature_err(
+ &tcx.sess.parse_sess,
+ sym::transparent_enums,
+ sp,
+ GateIssue::Language,
+ "transparent enums are unstable",
+ );
}
if adt.variants.len() != 1 {
- let variant_spans: Vec<_> = adt.variants.iter().map(|variant| {
- tcx.hir().span_if_local(variant.def_id).unwrap()
- }).collect();
- let mut err = struct_span_err!(tcx.sess, sp, E0731,
- "transparent enum needs exactly one variant, but has {}",
- adt.variants.len());
- if !variant_spans.is_empty() {
- err.span_note(variant_spans, &format!("the following variants exist on `{}`",
- tcx.def_path_str(def_id)));
- }
- err.emit();
+ bad_variant_count(tcx, adt, sp, def_id);
if adt.variants.is_empty() {
// Don't bother checking the fields. No variants (and thus no fields) exist.
return;
(span, zst, align1)
});
- let non_zst_fields = field_infos.clone().filter(|(_span, zst, _align1)| !*zst);
+ let non_zst_fields = field_infos.clone().filter_map(|(span, zst, _align1)| if !zst {
+ Some(span)
+ } else {
+ None
+ });
let non_zst_count = non_zst_fields.clone().count();
if non_zst_count != 1 {
- let field_spans: Vec<_> = non_zst_fields.map(|(span, _zst, _align1)| span).collect();
-
- let mut err = struct_span_err!(tcx.sess, sp, E0690,
- "{}transparent {} needs exactly one non-zero-sized field, but has {}",
- if adt.is_enum() { "the variant of a " } else { "" },
- adt.descr(),
- non_zst_count);
- if !field_spans.is_empty() {
- err.span_note(field_spans,
- &format!("the following non-zero-sized fields exist on `{}`:",
- tcx.def_path_str(def_id)));
- }
- err.emit();
+ bad_non_zero_sized_fields(tcx, adt, non_zst_count, non_zst_fields, sp);
}
for (span, zst, align1) in field_infos {
if zst && !align1 {
- span_err!(tcx.sess, span, E0691,
- "zero-sized field in transparent {} has alignment larger than 1",
- adt.descr());
+ struct_span_err!(
+ tcx.sess,
+ span,
+ E0691,
+ "zero-sized field in transparent {} has alignment larger than 1",
+ adt.descr(),
+ ).span_label(span, "has alignment larger than 1").emit();
}
}
}
}
}
+ if tcx.adt_def(def_id).repr.int.is_none() && tcx.features().arbitrary_enum_discriminant {
+ let is_unit =
+ |var: &hir::Variant| match var.node.data {
+ hir::VariantData::Unit(..) => true,
+ _ => false
+ };
+
+ let has_disr = |var: &hir::Variant| var.node.disr_expr.is_some();
+ let has_non_units = vs.iter().any(|var| !is_unit(var));
+ let disr_units = vs.iter().any(|var| is_unit(&var) && has_disr(&var));
+ let disr_non_unit = vs.iter().any(|var| !is_unit(&var) && has_disr(&var));
+
+ if disr_non_unit || (disr_units && has_non_units) {
+ let mut err = struct_span_err!(tcx.sess, sp, E0732,
+ "`#[repr(inttype)]` must be specified");
+ err.emit();
+ }
+ }
+
let mut disr_vals: Vec<Discr<'tcx>> = Vec::with_capacity(vs.len());
for ((_, discr), v) in def.discriminants(tcx).zip(vs) {
// Check for duplicate discriminant values
let variant_i_hir_id = tcx.hir().as_local_hir_id(variant_did).unwrap();
let variant_i = tcx.hir().expect_variant(variant_i_hir_id);
let i_span = match variant_i.node.disr_expr {
- Some(ref expr) => tcx.hir().span_by_hir_id(expr.hir_id),
- None => tcx.hir().span_by_hir_id(variant_i_hir_id)
+ Some(ref expr) => tcx.hir().span(expr.hir_id),
+ None => tcx.hir().span(variant_i_hir_id)
};
let span = match v.node.disr_expr {
- Some(ref expr) => tcx.hir().span_by_hir_id(expr.hir_id),
+ Some(ref expr) => tcx.hir().span(expr.hir_id),
None => v.span
};
struct_span_err!(tcx.sess, span, E0081,
check_transparent(tcx, sp, def_id);
}
-fn report_unexpected_variant_res<'tcx>(tcx: TyCtxt<'tcx>, res: Res, span: Span, qpath: &QPath) {
+fn report_unexpected_variant_res(tcx: TyCtxt<'_>, res: Res, span: Span, qpath: &QPath) {
span_err!(tcx.sess, span, E0533,
"expected unit struct/variant or constant, found {} `{}`",
res.descr(),
&self.tcx.sess
}
- pub fn err_count_since_creation(&self) -> usize {
- self.tcx.sess.err_count() - self.err_count_on_creation
+ pub fn errors_reported_since_creation(&self) -> bool {
+ self.tcx.sess.err_count() > self.err_count_on_creation
}
/// Produces warning on the given node, if the current point in the
pub fn local_ty(&self, span: Span, nid: hir::HirId) -> LocalTy<'tcx> {
self.locals.borrow().get(&nid).cloned().unwrap_or_else(||
span_bug!(span, "no type for local variable {}",
- self.tcx.hir().hir_to_string(nid))
+ self.tcx.hir().node_to_string(nid))
)
}
&self,
parent_id: hir::HirId,
value: &T,
+ value_span: Span,
) -> T {
let parent_def_id = self.tcx.hir().local_def_id_from_hir_id(parent_id);
debug!("instantiate_opaque_types_from_value(parent_def_id={:?}, value={:?})",
self.body_id,
self.param_env,
value,
+ value_span,
)
);
Some(&t) => t,
None if self.is_tainted_by_errors() => self.tcx.types.err,
None => {
- let node_id = self.tcx.hir().hir_to_node_id(id);
bug!("no type for node {}: {} in fcx {}",
- node_id, self.tcx.hir().node_to_string(node_id),
+ id, self.tcx.hir().node_to_string(id),
self.tag());
}
}
fn resolve_generator_interiors(&self, def_id: DefId) {
let mut generators = self.deferred_generator_interiors.borrow_mut();
- for (body_id, interior) in generators.drain(..) {
+ for (body_id, interior, kind) in generators.drain(..) {
self.select_obligations_where_possible(false);
- generator_interior::resolve_interior(self, def_id, body_id, interior);
+ generator_interior::resolve_interior(self, def_id, body_id, interior, kind);
}
}
}
}
- fn check_expr_eq_type(&self, expr: &'tcx hir::Expr, expected: Ty<'tcx>) {
- let ty = self.check_expr_with_hint(expr, expected);
- self.demand_eqtype(expr.span, expected, ty);
- }
-
- pub fn check_expr_has_type_or_error(
- &self,
- expr: &'tcx hir::Expr,
- expected: Ty<'tcx>,
- ) -> Ty<'tcx> {
- self.check_expr_meets_expectation_or_error(expr, ExpectHasType(expected))
- }
-
- fn check_expr_meets_expectation_or_error(
- &self,
- expr: &'tcx hir::Expr,
- expected: Expectation<'tcx>,
- ) -> Ty<'tcx> {
- let expected_ty = expected.to_option(&self).unwrap_or(self.tcx.types.bool);
- let mut ty = self.check_expr_with_expectation(expr, expected);
-
- // While we don't allow *arbitrary* coercions here, we *do* allow
- // coercions from ! to `expected`.
- if ty.is_never() {
- assert!(!self.tables.borrow().adjustments().contains_key(expr.hir_id),
- "expression with never type wound up being adjusted");
- let adj_ty = self.next_diverging_ty_var(
- TypeVariableOrigin {
- kind: TypeVariableOriginKind::AdjustmentType,
- span: expr.span,
- },
- );
- self.apply_adjustments(expr, vec![Adjustment {
- kind: Adjust::NeverToAny,
- target: adj_ty
- }]);
- ty = adj_ty;
- }
-
- if let Some(mut err) = self.demand_suptype_diag(expr.span, expected_ty, ty) {
- let expr = match &expr.node {
- ExprKind::DropTemps(expr) => expr,
- _ => expr,
- };
- // Error possibly reported in `check_assign` so avoid emitting error again.
- err.emit_unless(self.is_assign_to_bool(expr, expected_ty));
- }
- ty
- }
-
- fn check_expr_coercable_to_type(&self, expr: &'tcx hir::Expr, expected: Ty<'tcx>) -> Ty<'tcx> {
- let ty = self.check_expr_with_hint(expr, expected);
- // checks don't need two phase
- self.demand_coerce(expr, ty, expected, AllowTwoPhase::No)
- }
-
- fn check_expr_with_hint(&self, expr: &'tcx hir::Expr, expected: Ty<'tcx>) -> Ty<'tcx> {
- self.check_expr_with_expectation(expr, ExpectHasType(expected))
- }
-
- fn check_expr_with_expectation(
- &self,
- expr: &'tcx hir::Expr,
- expected: Expectation<'tcx>,
- ) -> Ty<'tcx> {
- self.check_expr_with_expectation_and_needs(expr, expected, Needs::None)
- }
-
- fn check_expr(&self, expr: &'tcx hir::Expr) -> Ty<'tcx> {
- self.check_expr_with_expectation(expr, NoExpectation)
- }
-
- fn check_expr_with_needs(&self, expr: &'tcx hir::Expr, needs: Needs) -> Ty<'tcx> {
- self.check_expr_with_expectation_and_needs(expr, NoExpectation, needs)
- }
-
// Determine the `Self` type, using fresh variables for all variables
// declared on the impl declaration e.g., `impl<A,B> for Vec<(A,B)>`
// would return `($0, $1)` where `$0` and `$1` are freshly instantiated type
expect_args
}
- // Checks a method call.
- fn check_method_call(
- &self,
- expr: &'tcx hir::Expr,
- segment: &hir::PathSegment,
- span: Span,
- args: &'tcx [hir::Expr],
- expected: Expectation<'tcx>,
- needs: Needs,
- ) -> Ty<'tcx> {
- let rcvr = &args[0];
- let rcvr_t = self.check_expr_with_needs(&rcvr, needs);
- // no need to check for bot/err -- callee does that
- let rcvr_t = self.structurally_resolved_type(args[0].span, rcvr_t);
-
- let method = match self.lookup_method(rcvr_t,
- segment,
- span,
- expr,
- rcvr) {
- Ok(method) => {
- self.write_method_call(expr.hir_id, method);
- Ok(method)
- }
- Err(error) => {
- if segment.ident.name != kw::Invalid {
- self.report_method_error(span,
- rcvr_t,
- segment.ident,
- SelfSource::MethodCall(rcvr),
- error,
- Some(args));
- }
- Err(())
- }
- };
-
- // Call the generic checker.
- self.check_method_argument_types(span,
- expr.span,
- method,
- &args[1..],
- DontTupleArguments,
- expected)
- }
-
- fn check_return_expr(&self, return_expr: &'tcx hir::Expr) {
- let ret_coercion =
- self.ret_coercion
- .as_ref()
- .unwrap_or_else(|| span_bug!(return_expr.span,
- "check_return_expr called outside fn body"));
-
- let ret_ty = ret_coercion.borrow().expected_ty();
- let return_expr_ty = self.check_expr_with_hint(return_expr, ret_ty.clone());
- ret_coercion.borrow_mut()
- .coerce(self,
- &self.cause(return_expr.span,
- ObligationCauseCode::ReturnType(return_expr.hir_id)),
- return_expr,
- return_expr_ty);
- }
-
- // Check field access expressions
- fn check_field(
- &self,
- expr: &'tcx hir::Expr,
- needs: Needs,
- base: &'tcx hir::Expr,
- field: ast::Ident,
- ) -> Ty<'tcx> {
- let expr_t = self.check_expr_with_needs(base, needs);
- let expr_t = self.structurally_resolved_type(base.span,
- expr_t);
- let mut private_candidate = None;
- let mut autoderef = self.autoderef(expr.span, expr_t);
- while let Some((base_t, _)) = autoderef.next() {
- match base_t.sty {
- ty::Adt(base_def, substs) if !base_def.is_enum() => {
- debug!("struct named {:?}", base_t);
- let (ident, def_scope) =
- self.tcx.adjust_ident_and_get_scope(field, base_def.did, self.body_id);
- let fields = &base_def.non_enum_variant().fields;
- if let Some(index) = fields.iter().position(|f| f.ident.modern() == ident) {
- let field = &fields[index];
- let field_ty = self.field_ty(expr.span, field, substs);
- // Save the index of all fields regardless of their visibility in case
- // of error recovery.
- self.write_field_index(expr.hir_id, index);
- if field.vis.is_accessible_from(def_scope, self.tcx) {
- let adjustments = autoderef.adjust_steps(self, needs);
- self.apply_adjustments(base, adjustments);
- autoderef.finalize(self);
-
- self.tcx.check_stability(field.did, Some(expr.hir_id), expr.span);
- return field_ty;
- }
- private_candidate = Some((base_def.did, field_ty));
- }
- }
- ty::Tuple(ref tys) => {
- let fstr = field.as_str();
- if let Ok(index) = fstr.parse::<usize>() {
- if fstr == index.to_string() {
- if let Some(field_ty) = tys.get(index) {
- let adjustments = autoderef.adjust_steps(self, needs);
- self.apply_adjustments(base, adjustments);
- autoderef.finalize(self);
-
- self.write_field_index(expr.hir_id, index);
- return field_ty.expect_ty();
- }
- }
- }
- }
- _ => {}
- }
- }
- autoderef.unambiguous_final_ty(self);
-
- if let Some((did, field_ty)) = private_candidate {
- let struct_path = self.tcx().def_path_str(did);
- let mut err = struct_span_err!(self.tcx().sess, expr.span, E0616,
- "field `{}` of struct `{}` is private",
- field, struct_path);
- // Also check if an accessible method exists, which is often what is meant.
- if self.method_exists(field, expr_t, expr.hir_id, false)
- && !self.expr_in_place(expr.hir_id)
- {
- self.suggest_method_call(
- &mut err,
- &format!("a method `{}` also exists, call it with parentheses", field),
- field,
- expr_t,
- expr.hir_id,
- );
- }
- err.emit();
- field_ty
- } else if field.name == kw::Invalid {
- self.tcx().types.err
- } else if self.method_exists(field, expr_t, expr.hir_id, true) {
- let mut err = type_error_struct!(self.tcx().sess, field.span, expr_t, E0615,
- "attempted to take value of method `{}` on type `{}`",
- field, expr_t);
-
- if !self.expr_in_place(expr.hir_id) {
- self.suggest_method_call(
- &mut err,
- "use parentheses to call the method",
- field,
- expr_t,
- expr.hir_id
- );
- } else {
- err.help("methods are immutable and cannot be assigned to");
- }
-
- err.emit();
- self.tcx().types.err
- } else {
- if !expr_t.is_primitive_ty() {
- let mut err = self.no_such_field_err(field.span, field, expr_t);
-
- match expr_t.sty {
- ty::Adt(def, _) if !def.is_enum() => {
- if let Some(suggested_field_name) =
- Self::suggest_field_name(def.non_enum_variant(),
- &field.as_str(), vec![]) {
- err.span_suggestion(
- field.span,
- "a field with a similar name exists",
- suggested_field_name.to_string(),
- Applicability::MaybeIncorrect,
- );
- } else {
- err.span_label(field.span, "unknown field");
- let struct_variant_def = def.non_enum_variant();
- let field_names = self.available_field_names(struct_variant_def);
- if !field_names.is_empty() {
- err.note(&format!("available fields are: {}",
- self.name_series_display(field_names)));
- }
- };
- }
- ty::Array(_, len) => {
- if let (Some(len), Ok(user_index)) = (
- len.assert_usize(self.tcx),
- field.as_str().parse::<u64>()
- ) {
- let base = self.tcx.sess.source_map()
- .span_to_snippet(base.span)
- .unwrap_or_else(|_|
- self.tcx.hir().hir_to_pretty_string(base.hir_id));
- let help = "instead of using tuple indexing, use array indexing";
- let suggestion = format!("{}[{}]", base, field);
- let applicability = if len < user_index {
- Applicability::MachineApplicable
- } else {
- Applicability::MaybeIncorrect
- };
- err.span_suggestion(
- expr.span, help, suggestion, applicability
- );
- }
- }
- ty::RawPtr(..) => {
- let base = self.tcx.sess.source_map()
- .span_to_snippet(base.span)
- .unwrap_or_else(|_| self.tcx.hir().hir_to_pretty_string(base.hir_id));
- let msg = format!("`{}` is a raw pointer; try dereferencing it", base);
- let suggestion = format!("(*{}).{}", base, field);
- err.span_suggestion(
- expr.span,
- &msg,
- suggestion,
- Applicability::MaybeIncorrect,
- );
- }
- _ => {}
- }
- err
- } else {
- type_error_struct!(self.tcx().sess, field.span, expr_t, E0610,
- "`{}` is a primitive type and therefore doesn't have fields",
- expr_t)
- }.emit();
- self.tcx().types.err
- }
- }
-
- // Return an hint about the closest match in field names
- fn suggest_field_name(variant: &'tcx ty::VariantDef,
- field: &str,
- skip: Vec<LocalInternedString>)
- -> Option<Symbol> {
- let names = variant.fields.iter().filter_map(|field| {
- // ignore already set fields and private fields from non-local crates
- if skip.iter().any(|x| *x == field.ident.as_str()) ||
- (!variant.def_id.is_local() && field.vis != Visibility::Public)
- {
- None
- } else {
- Some(&field.ident.name)
- }
- });
-
- find_best_match_for_name(names, field, None)
- }
-
- fn available_field_names(&self, variant: &'tcx ty::VariantDef) -> Vec<ast::Name> {
- variant.fields.iter().filter(|field| {
- let def_scope =
- self.tcx.adjust_ident_and_get_scope(field.ident, variant.def_id, self.body_id).1;
- field.vis.is_accessible_from(def_scope, self.tcx)
- })
- .map(|field| field.ident.name)
- .collect()
- }
-
- fn name_series_display(&self, names: Vec<ast::Name>) -> String {
- // dynamic limit, to never omit just one field
- let limit = if names.len() == 6 { 6 } else { 5 };
- let mut display = names.iter().take(limit)
- .map(|n| format!("`{}`", n)).collect::<Vec<_>>().join(", ");
- if names.len() > limit {
- display = format!("{} ... and {} others", display, names.len() - limit);
- }
- display
- }
-
- fn no_such_field_err<T: Display>(&self, span: Span, field: T, expr_t: &ty::TyS<'_>)
- -> DiagnosticBuilder<'_> {
- type_error_struct!(self.tcx().sess, span, expr_t, E0609,
- "no field `{}` on type `{}`",
- field, expr_t)
- }
-
- fn report_unknown_field(
- &self,
- ty: Ty<'tcx>,
- variant: &'tcx ty::VariantDef,
- field: &hir::Field,
- skip_fields: &[hir::Field],
- kind_name: &str,
- ) {
- if variant.recovered {
- return;
- }
- let mut err = self.type_error_struct_with_diag(
- field.ident.span,
- |actual| match ty.sty {
- ty::Adt(adt, ..) if adt.is_enum() => {
- struct_span_err!(self.tcx.sess, field.ident.span, E0559,
- "{} `{}::{}` has no field named `{}`",
- kind_name, actual, variant.ident, field.ident)
- }
- _ => {
- struct_span_err!(self.tcx.sess, field.ident.span, E0560,
- "{} `{}` has no field named `{}`",
- kind_name, actual, field.ident)
- }
- },
- ty);
- // prevent all specified fields from being suggested
- let skip_fields = skip_fields.iter().map(|ref x| x.ident.as_str());
- if let Some(field_name) = Self::suggest_field_name(variant,
- &field.ident.as_str(),
- skip_fields.collect()) {
- err.span_suggestion(
- field.ident.span,
- "a field with a similar name exists",
- field_name.to_string(),
- Applicability::MaybeIncorrect,
- );
- } else {
- match ty.sty {
- ty::Adt(adt, ..) => {
- if adt.is_enum() {
- err.span_label(field.ident.span,
- format!("`{}::{}` does not have this field",
- ty, variant.ident));
- } else {
- err.span_label(field.ident.span,
- format!("`{}` does not have this field", ty));
- }
- let available_field_names = self.available_field_names(variant);
- if !available_field_names.is_empty() {
- err.note(&format!("available fields are: {}",
- self.name_series_display(available_field_names)));
- }
- }
- _ => bug!("non-ADT passed to report_unknown_field")
- }
- };
- err.emit();
- }
-
- fn check_expr_struct_fields(
- &self,
- adt_ty: Ty<'tcx>,
- expected: Expectation<'tcx>,
- expr_id: hir::HirId,
- span: Span,
- variant: &'tcx ty::VariantDef,
- ast_fields: &'tcx [hir::Field],
- check_completeness: bool,
- ) -> bool {
- let tcx = self.tcx;
-
- let adt_ty_hint =
- self.expected_inputs_for_expected_output(span, expected, adt_ty, &[adt_ty])
- .get(0).cloned().unwrap_or(adt_ty);
- // re-link the regions that EIfEO can erase.
- self.demand_eqtype(span, adt_ty_hint, adt_ty);
-
- let (substs, adt_kind, kind_name) = match &adt_ty.sty {
- &ty::Adt(adt, substs) => {
- (substs, adt.adt_kind(), adt.variant_descr())
- }
- _ => span_bug!(span, "non-ADT passed to check_expr_struct_fields")
- };
-
- let mut remaining_fields = variant.fields.iter().enumerate().map(|(i, field)|
- (field.ident.modern(), (i, field))
- ).collect::<FxHashMap<_, _>>();
-
- let mut seen_fields = FxHashMap::default();
-
- let mut error_happened = false;
-
- // Type-check each field.
- for field in ast_fields {
- let ident = tcx.adjust_ident(field.ident, variant.def_id);
- let field_type = if let Some((i, v_field)) = remaining_fields.remove(&ident) {
- seen_fields.insert(ident, field.span);
- self.write_field_index(field.hir_id, i);
-
- // We don't look at stability attributes on
- // struct-like enums (yet...), but it's definitely not
- // a bug to have constructed one.
- if adt_kind != AdtKind::Enum {
- tcx.check_stability(v_field.did, Some(expr_id), field.span);
- }
-
- self.field_ty(field.span, v_field, substs)
- } else {
- error_happened = true;
- if let Some(prev_span) = seen_fields.get(&ident) {
- let mut err = struct_span_err!(self.tcx.sess,
- field.ident.span,
- E0062,
- "field `{}` specified more than once",
- ident);
-
- err.span_label(field.ident.span, "used more than once");
- err.span_label(*prev_span, format!("first use of `{}`", ident));
-
- err.emit();
- } else {
- self.report_unknown_field(adt_ty, variant, field, ast_fields, kind_name);
- }
-
- tcx.types.err
- };
-
- // Make sure to give a type to the field even if there's
- // an error, so we can continue type-checking.
- self.check_expr_coercable_to_type(&field.expr, field_type);
- }
-
- // Make sure the programmer specified correct number of fields.
- if kind_name == "union" {
- if ast_fields.len() != 1 {
- tcx.sess.span_err(span, "union expressions should have exactly one field");
- }
- } else if check_completeness && !error_happened && !remaining_fields.is_empty() {
- let len = remaining_fields.len();
-
- let mut displayable_field_names = remaining_fields
- .keys()
- .map(|ident| ident.as_str())
- .collect::<Vec<_>>();
-
- displayable_field_names.sort();
-
- let truncated_fields_error = if len <= 3 {
- String::new()
- } else {
- format!(" and {} other field{}", (len - 3), if len - 3 == 1 {""} else {"s"})
- };
-
- let remaining_fields_names = displayable_field_names.iter().take(3)
- .map(|n| format!("`{}`", n))
- .collect::<Vec<_>>()
- .join(", ");
-
- struct_span_err!(tcx.sess, span, E0063,
- "missing field{} {}{} in initializer of `{}`",
- if remaining_fields.len() == 1 { "" } else { "s" },
- remaining_fields_names,
- truncated_fields_error,
- adt_ty)
- .span_label(span, format!("missing {}{}",
- remaining_fields_names,
- truncated_fields_error))
- .emit();
- }
- error_happened
- }
-
- fn check_struct_fields_on_error(
- &self,
- fields: &'tcx [hir::Field],
- base_expr: &'tcx Option<P<hir::Expr>>,
- ) {
- for field in fields {
- self.check_expr(&field.expr);
- }
- if let Some(ref base) = *base_expr {
- self.check_expr(&base);
- }
- }
-
pub fn check_struct_path(&self,
qpath: &QPath,
hir_id: hir::HirId)
}
}
- fn check_expr_struct(
- &self,
- expr: &hir::Expr,
- expected: Expectation<'tcx>,
- qpath: &QPath,
- fields: &'tcx [hir::Field],
- base_expr: &'tcx Option<P<hir::Expr>>,
- ) -> Ty<'tcx> {
- // Find the relevant variant
- let (variant, adt_ty) =
- if let Some(variant_ty) = self.check_struct_path(qpath, expr.hir_id) {
- variant_ty
- } else {
- self.check_struct_fields_on_error(fields, base_expr);
- return self.tcx.types.err;
- };
+ // Finish resolving a path in a struct expression or pattern `S::A { .. }` if necessary.
+ // The newly resolved definition is written into `type_dependent_defs`.
+ fn finish_resolving_struct_path(&self,
+ qpath: &QPath,
+ path_span: Span,
+ hir_id: hir::HirId)
+ -> (Res, Ty<'tcx>)
+ {
+ match *qpath {
+ QPath::Resolved(ref maybe_qself, ref path) => {
+ let self_ty = maybe_qself.as_ref().map(|qself| self.to_ty(qself));
+ let ty = AstConv::res_to_ty(self, self_ty, path, true);
+ (path.res, ty)
+ }
+ QPath::TypeRelative(ref qself, ref segment) => {
+ let ty = self.to_ty(qself);
- let path_span = match *qpath {
- QPath::Resolved(_, ref path) => path.span,
- QPath::TypeRelative(ref qself, _) => qself.span
- };
+ let res = if let hir::TyKind::Path(QPath::Resolved(_, ref path)) = qself.node {
+ path.res
+ } else {
+ Res::Err
+ };
+ let result = AstConv::associated_path_to_ty(
+ self,
+ hir_id,
+ path_span,
+ ty,
+ res,
+ segment,
+ true,
+ );
+ let ty = result.map(|(ty, _, _)| ty).unwrap_or(self.tcx().types.err);
+ let result = result.map(|(_, kind, def_id)| (kind, def_id));
- // Prohibit struct expressions when non-exhaustive flag is set.
- let adt = adt_ty.ty_adt_def().expect("`check_struct_path` returned non-ADT type");
- if !adt.did.is_local() && variant.is_field_list_non_exhaustive() {
- span_err!(self.tcx.sess, expr.span, E0639,
- "cannot create non-exhaustive {} using struct expression",
- adt.variant_descr());
- }
+ // Write back the new resolution.
+ self.write_resolution(hir_id, result);
- let error_happened = self.check_expr_struct_fields(adt_ty, expected, expr.hir_id, path_span,
- variant, fields, base_expr.is_none());
- if let &Some(ref base_expr) = base_expr {
- // If check_expr_struct_fields hit an error, do not attempt to populate
- // the fields with the base_expr. This could cause us to hit errors later
- // when certain fields are assumed to exist that in fact do not.
- if !error_happened {
- self.check_expr_has_type_or_error(base_expr, adt_ty);
- match adt_ty.sty {
- ty::Adt(adt, substs) if adt.is_struct() => {
- let fru_field_types = adt.non_enum_variant().fields.iter().map(|f| {
- self.normalize_associated_types_in(expr.span, &f.ty(self.tcx, substs))
- }).collect();
-
- self.tables
- .borrow_mut()
- .fru_field_types_mut()
- .insert(expr.hir_id, fru_field_types);
- }
- _ => {
- span_err!(self.tcx.sess, base_expr.span, E0436,
- "functional record update syntax requires a struct");
- }
- }
- }
- }
- self.require_type_is_sized(adt_ty, expr.span, traits::StructInitializerSized);
- adt_ty
- }
-
-
- /// Invariant:
- /// If an expression has any sub-expressions that result in a type error,
- /// inspecting that expression's type with `ty.references_error()` will return
- /// true. Likewise, if an expression is known to diverge, inspecting its
- /// type with `ty::type_is_bot` will return true (n.b.: since Rust is
- /// strict, _|_ can appear in the type of an expression that does not,
- /// itself, diverge: for example, fn() -> _|_.)
- /// Note that inspecting a type's structure *directly* may expose the fact
- /// that there are actually multiple representations for `Error`, so avoid
- /// that when err needs to be handled differently.
- fn check_expr_with_expectation_and_needs(
- &self,
- expr: &'tcx hir::Expr,
- expected: Expectation<'tcx>,
- needs: Needs,
- ) -> Ty<'tcx> {
- debug!(">> type-checking: expr={:?} expected={:?}",
- expr, expected);
-
- // Warn for expressions after diverging siblings.
- self.warn_if_unreachable(expr.hir_id, expr.span, "expression");
-
- // Hide the outer diverging and has_errors flags.
- let old_diverges = self.diverges.get();
- let old_has_errors = self.has_errors.get();
- self.diverges.set(Diverges::Maybe);
- self.has_errors.set(false);
-
- let ty = self.check_expr_kind(expr, expected, needs);
-
- // Warn for non-block expressions with diverging children.
- match expr.node {
- ExprKind::Block(..) |
- ExprKind::Loop(..) | ExprKind::While(..) |
- ExprKind::Match(..) => {}
-
- _ => self.warn_if_unreachable(expr.hir_id, expr.span, "expression")
- }
-
- // Any expression that produces a value of type `!` must have diverged
- if ty.is_never() {
- self.diverges.set(self.diverges.get() | Diverges::Always);
- }
-
- // Record the type, which applies it effects.
- // We need to do this after the warning above, so that
- // we don't warn for the diverging expression itself.
- self.write_ty(expr.hir_id, ty);
-
- // Combine the diverging and has_error flags.
- self.diverges.set(self.diverges.get() | old_diverges);
- self.has_errors.set(self.has_errors.get() | old_has_errors);
-
- debug!("type of {} is...", self.tcx.hir().hir_to_string(expr.hir_id));
- debug!("... {:?}, expected is {:?}", ty, expected);
-
- ty
- }
-
- fn check_expr_kind(
- &self,
- expr: &'tcx hir::Expr,
- expected: Expectation<'tcx>,
- needs: Needs,
- ) -> Ty<'tcx> {
- debug!(
- "check_expr_kind(expr={:?}, expected={:?}, needs={:?})",
- expr,
- expected,
- needs,
- );
-
- let tcx = self.tcx;
- let id = expr.hir_id;
- match expr.node {
- ExprKind::Box(ref subexpr) => {
- let expected_inner = expected.to_option(self).map_or(NoExpectation, |ty| {
- match ty.sty {
- ty::Adt(def, _) if def.is_box()
- => Expectation::rvalue_hint(self, ty.boxed_ty()),
- _ => NoExpectation
- }
- });
- let referent_ty = self.check_expr_with_expectation(subexpr, expected_inner);
- tcx.mk_box(referent_ty)
- }
-
- ExprKind::Lit(ref lit) => {
- self.check_lit(&lit, expected)
- }
- ExprKind::Binary(op, ref lhs, ref rhs) => {
- self.check_binop(expr, op, lhs, rhs)
- }
- ExprKind::AssignOp(op, ref lhs, ref rhs) => {
- self.check_binop_assign(expr, op, lhs, rhs)
- }
- ExprKind::Unary(unop, ref oprnd) => {
- let expected_inner = match unop {
- hir::UnNot | hir::UnNeg => {
- expected
- }
- hir::UnDeref => {
- NoExpectation
- }
- };
- let needs = match unop {
- hir::UnDeref => needs,
- _ => Needs::None
- };
- let mut oprnd_t = self.check_expr_with_expectation_and_needs(&oprnd,
- expected_inner,
- needs);
-
- if !oprnd_t.references_error() {
- oprnd_t = self.structurally_resolved_type(expr.span, oprnd_t);
- match unop {
- hir::UnDeref => {
- if let Some(mt) = oprnd_t.builtin_deref(true) {
- oprnd_t = mt.ty;
- } else if let Some(ok) = self.try_overloaded_deref(
- expr.span, oprnd_t, needs) {
- let method = self.register_infer_ok_obligations(ok);
- if let ty::Ref(region, _, mutbl) = method.sig.inputs()[0].sty {
- let mutbl = match mutbl {
- hir::MutImmutable => AutoBorrowMutability::Immutable,
- hir::MutMutable => AutoBorrowMutability::Mutable {
- // (It shouldn't actually matter for unary ops whether
- // we enable two-phase borrows or not, since a unary
- // op has no additional operands.)
- allow_two_phase_borrow: AllowTwoPhase::No,
- }
- };
- self.apply_adjustments(oprnd, vec![Adjustment {
- kind: Adjust::Borrow(AutoBorrow::Ref(region, mutbl)),
- target: method.sig.inputs()[0]
- }]);
- }
- oprnd_t = self.make_overloaded_place_return_type(method).ty;
- self.write_method_call(expr.hir_id, method);
- } else {
- let mut err = type_error_struct!(
- tcx.sess,
- expr.span,
- oprnd_t,
- E0614,
- "type `{}` cannot be dereferenced",
- oprnd_t,
- );
- let sp = tcx.sess.source_map().start_point(expr.span);
- if let Some(sp) = tcx.sess.parse_sess.ambiguous_block_expr_parse
- .borrow().get(&sp)
- {
- tcx.sess.parse_sess.expr_parentheses_needed(
- &mut err,
- *sp,
- None,
- );
- }
- err.emit();
- oprnd_t = tcx.types.err;
- }
- }
- hir::UnNot => {
- let result = self.check_user_unop(expr, oprnd_t, unop);
- // If it's builtin, we can reuse the type, this helps inference.
- if !(oprnd_t.is_integral() || oprnd_t.sty == ty::Bool) {
- oprnd_t = result;
- }
- }
- hir::UnNeg => {
- let result = self.check_user_unop(expr, oprnd_t, unop);
- // If it's builtin, we can reuse the type, this helps inference.
- if !oprnd_t.is_numeric() {
- oprnd_t = result;
- }
- }
- }
- }
- oprnd_t
- }
- ExprKind::AddrOf(mutbl, ref oprnd) => {
- let hint = expected.only_has_type(self).map_or(NoExpectation, |ty| {
- match ty.sty {
- ty::Ref(_, ty, _) | ty::RawPtr(ty::TypeAndMut { ty, .. }) => {
- if oprnd.is_place_expr() {
- // Places may legitimately have unsized types.
- // For example, dereferences of a fat pointer and
- // the last field of a struct can be unsized.
- ExpectHasType(ty)
- } else {
- Expectation::rvalue_hint(self, ty)
- }
- }
- _ => NoExpectation
- }
- });
- let needs = Needs::maybe_mut_place(mutbl);
- let ty = self.check_expr_with_expectation_and_needs(&oprnd, hint, needs);
-
- let tm = ty::TypeAndMut { ty: ty, mutbl: mutbl };
- if tm.ty.references_error() {
- tcx.types.err
- } else {
- // Note: at this point, we cannot say what the best lifetime
- // is to use for resulting pointer. We want to use the
- // shortest lifetime possible so as to avoid spurious borrowck
- // errors. Moreover, the longest lifetime will depend on the
- // precise details of the value whose address is being taken
- // (and how long it is valid), which we don't know yet until type
- // inference is complete.
- //
- // Therefore, here we simply generate a region variable. The
- // region inferencer will then select the ultimate value.
- // Finally, borrowck is charged with guaranteeing that the
- // value whose address was taken can actually be made to live
- // as long as it needs to live.
- let region = self.next_region_var(infer::AddrOfRegion(expr.span));
- tcx.mk_ref(region, tm)
- }
- }
- ExprKind::Path(ref qpath) => {
- let (res, opt_ty, segs) = self.resolve_ty_and_res_ufcs(qpath, expr.hir_id,
- expr.span);
- let ty = match res {
- Res::Err => {
- self.set_tainted_by_errors();
- tcx.types.err
- }
- Res::Def(DefKind::Ctor(_, CtorKind::Fictive), _) => {
- report_unexpected_variant_res(tcx, res, expr.span, qpath);
- tcx.types.err
- }
- _ => self.instantiate_value_path(segs, opt_ty, res, expr.span, id).0,
- };
-
- if let ty::FnDef(..) = ty.sty {
- let fn_sig = ty.fn_sig(tcx);
- if !tcx.features().unsized_locals {
- // We want to remove some Sized bounds from std functions,
- // but don't want to expose the removal to stable Rust.
- // i.e., we don't want to allow
- //
- // ```rust
- // drop as fn(str);
- // ```
- //
- // to work in stable even if the Sized bound on `drop` is relaxed.
- for i in 0..fn_sig.inputs().skip_binder().len() {
- // We just want to check sizedness, so instead of introducing
- // placeholder lifetimes with probing, we just replace higher lifetimes
- // with fresh vars.
- let input = self.replace_bound_vars_with_fresh_vars(
- expr.span,
- infer::LateBoundRegionConversionTime::FnCall,
- &fn_sig.input(i)).0;
- self.require_type_is_sized_deferred(input, expr.span,
- traits::SizedArgumentType);
- }
- }
- // Here we want to prevent struct constructors from returning unsized types.
- // There were two cases this happened: fn pointer coercion in stable
- // and usual function call in presense of unsized_locals.
- // Also, as we just want to check sizedness, instead of introducing
- // placeholder lifetimes with probing, we just replace higher lifetimes
- // with fresh vars.
- let output = self.replace_bound_vars_with_fresh_vars(
- expr.span,
- infer::LateBoundRegionConversionTime::FnCall,
- &fn_sig.output()).0;
- self.require_type_is_sized_deferred(output, expr.span, traits::SizedReturnType);
- }
-
- // We always require that the type provided as the value for
- // a type parameter outlives the moment of instantiation.
- let substs = self.tables.borrow().node_substs(expr.hir_id);
- self.add_wf_bounds(substs, expr);
-
- ty
- }
- ExprKind::InlineAsm(_, ref outputs, ref inputs) => {
- for expr in outputs.iter().chain(inputs.iter()) {
- self.check_expr(expr);
- }
- tcx.mk_unit()
- }
- ExprKind::Break(destination, ref expr_opt) => {
- if let Ok(target_id) = destination.target_id {
- let (e_ty, cause);
- if let Some(ref e) = *expr_opt {
- // If this is a break with a value, we need to type-check
- // the expression. Get an expected type from the loop context.
- let opt_coerce_to = {
- let mut enclosing_breakables = self.enclosing_breakables.borrow_mut();
- enclosing_breakables.find_breakable(target_id)
- .coerce
- .as_ref()
- .map(|coerce| coerce.expected_ty())
- };
-
- // If the loop context is not a `loop { }`, then break with
- // a value is illegal, and `opt_coerce_to` will be `None`.
- // Just set expectation to error in that case.
- let coerce_to = opt_coerce_to.unwrap_or(tcx.types.err);
-
- // Recurse without `enclosing_breakables` borrowed.
- e_ty = self.check_expr_with_hint(e, coerce_to);
- cause = self.misc(e.span);
- } else {
- // Otherwise, this is a break *without* a value. That's
- // always legal, and is equivalent to `break ()`.
- e_ty = tcx.mk_unit();
- cause = self.misc(expr.span);
- }
-
- // Now that we have type-checked `expr_opt`, borrow
- // the `enclosing_loops` field and let's coerce the
- // type of `expr_opt` into what is expected.
- let mut enclosing_breakables = self.enclosing_breakables.borrow_mut();
- let ctxt = enclosing_breakables.find_breakable(target_id);
- if let Some(ref mut coerce) = ctxt.coerce {
- if let Some(ref e) = *expr_opt {
- coerce.coerce(self, &cause, e, e_ty);
- } else {
- assert!(e_ty.is_unit());
- coerce.coerce_forced_unit(self, &cause, &mut |_| (), true);
- }
- } else {
- // If `ctxt.coerce` is `None`, we can just ignore
- // the type of the expresison. This is because
- // either this was a break *without* a value, in
- // which case it is always a legal type (`()`), or
- // else an error would have been flagged by the
- // `loops` pass for using break with an expression
- // where you are not supposed to.
- assert!(expr_opt.is_none() || self.tcx.sess.err_count() > 0);
- }
-
- ctxt.may_break = true;
-
- // the type of a `break` is always `!`, since it diverges
- tcx.types.never
- } else {
- // Otherwise, we failed to find the enclosing loop;
- // this can only happen if the `break` was not
- // inside a loop at all, which is caught by the
- // loop-checking pass.
- if self.tcx.sess.err_count() == 0 {
- self.tcx.sess.delay_span_bug(expr.span,
- "break was outside loop, but no error was emitted");
- }
-
- // We still need to assign a type to the inner expression to
- // prevent the ICE in #43162.
- if let Some(ref e) = *expr_opt {
- self.check_expr_with_hint(e, tcx.types.err);
-
- // ... except when we try to 'break rust;'.
- // ICE this expression in particular (see #43162).
- if let ExprKind::Path(QPath::Resolved(_, ref path)) = e.node {
- if path.segments.len() == 1 &&
- path.segments[0].ident.name == sym::rust {
- fatally_break_rust(self.tcx.sess);
- }
- }
- }
- // There was an error; make type-check fail.
- tcx.types.err
- }
-
- }
- ExprKind::Continue(destination) => {
- if destination.target_id.is_ok() {
- tcx.types.never
- } else {
- // There was an error; make type-check fail.
- tcx.types.err
- }
- }
- ExprKind::Ret(ref expr_opt) => {
- if self.ret_coercion.is_none() {
- struct_span_err!(self.tcx.sess, expr.span, E0572,
- "return statement outside of function body").emit();
- } else if let Some(ref e) = *expr_opt {
- if self.ret_coercion_span.borrow().is_none() {
- *self.ret_coercion_span.borrow_mut() = Some(e.span);
- }
- self.check_return_expr(e);
- } else {
- let mut coercion = self.ret_coercion.as_ref().unwrap().borrow_mut();
- if self.ret_coercion_span.borrow().is_none() {
- *self.ret_coercion_span.borrow_mut() = Some(expr.span);
- }
- let cause = self.cause(expr.span, ObligationCauseCode::ReturnNoExpression);
- if let Some((fn_decl, _)) = self.get_fn_decl(expr.hir_id) {
- coercion.coerce_forced_unit(
- self,
- &cause,
- &mut |db| {
- db.span_label(
- fn_decl.output.span(),
- format!(
- "expected `{}` because of this return type",
- fn_decl.output,
- ),
- );
- },
- true,
- );
- } else {
- coercion.coerce_forced_unit(self, &cause, &mut |_| (), true);
- }
- }
- tcx.types.never
- }
- ExprKind::Assign(ref lhs, ref rhs) => {
- self.check_assign(expr, expected, lhs, rhs)
- }
- ExprKind::While(ref cond, ref body, _) => {
- let ctxt = BreakableCtxt {
- // cannot use break with a value from a while loop
- coerce: None,
- may_break: false, // Will get updated if/when we find a `break`.
- };
-
- let (ctxt, ()) = self.with_breakable_ctxt(expr.hir_id, ctxt, || {
- self.check_expr_has_type_or_error(&cond, tcx.types.bool);
- let cond_diverging = self.diverges.get();
- self.check_block_no_value(&body);
-
- // We may never reach the body so it diverging means nothing.
- self.diverges.set(cond_diverging);
- });
-
- if ctxt.may_break {
- // No way to know whether it's diverging because
- // of a `break` or an outer `break` or `return`.
- self.diverges.set(Diverges::Maybe);
- }
-
- self.tcx.mk_unit()
- }
- ExprKind::Loop(ref body, _, source) => {
- let coerce = match source {
- // you can only use break with a value from a normal `loop { }`
- hir::LoopSource::Loop => {
- let coerce_to = expected.coercion_target_type(self, body.span);
- Some(CoerceMany::new(coerce_to))
- }
-
- hir::LoopSource::WhileLet |
- hir::LoopSource::ForLoop => {
- None
- }
- };
-
- let ctxt = BreakableCtxt {
- coerce,
- may_break: false, // Will get updated if/when we find a `break`.
- };
-
- let (ctxt, ()) = self.with_breakable_ctxt(expr.hir_id, ctxt, || {
- self.check_block_no_value(&body);
- });
-
- if ctxt.may_break {
- // No way to know whether it's diverging because
- // of a `break` or an outer `break` or `return`.
- self.diverges.set(Diverges::Maybe);
- }
-
- // If we permit break with a value, then result type is
- // the LUB of the breaks (possibly ! if none); else, it
- // is nil. This makes sense because infinite loops
- // (which would have type !) are only possible iff we
- // permit break with a value [1].
- if ctxt.coerce.is_none() && !ctxt.may_break {
- // [1]
- self.tcx.sess.delay_span_bug(body.span, "no coercion, but loop may not break");
- }
- ctxt.coerce.map(|c| c.complete(self)).unwrap_or_else(|| self.tcx.mk_unit())
- }
- ExprKind::Match(ref discrim, ref arms, match_src) => {
- self.check_match(expr, &discrim, arms, expected, match_src)
- }
- ExprKind::Closure(capture, ref decl, body_id, _, gen) => {
- self.check_expr_closure(expr, capture, &decl, body_id, gen, expected)
- }
- ExprKind::Block(ref body, _) => {
- self.check_block_with_expected(&body, expected)
- }
- ExprKind::Call(ref callee, ref args) => {
- self.check_call(expr, &callee, args, expected)
- }
- ExprKind::MethodCall(ref segment, span, ref args) => {
- self.check_method_call(expr, segment, span, args, expected, needs)
- }
- ExprKind::Cast(ref e, ref t) => {
- // Find the type of `e`. Supply hints based on the type we are casting to,
- // if appropriate.
- let t_cast = self.to_ty_saving_user_provided_ty(t);
- let t_cast = self.resolve_vars_if_possible(&t_cast);
- let t_expr = self.check_expr_with_expectation(e, ExpectCastableToType(t_cast));
- let t_cast = self.resolve_vars_if_possible(&t_cast);
-
- // Eagerly check for some obvious errors.
- if t_expr.references_error() || t_cast.references_error() {
- tcx.types.err
- } else {
- // Defer other checks until we're done type checking.
- let mut deferred_cast_checks = self.deferred_cast_checks.borrow_mut();
- match cast::CastCheck::new(self, e, t_expr, t_cast, t.span, expr.span) {
- Ok(cast_check) => {
- deferred_cast_checks.push(cast_check);
- t_cast
- }
- Err(ErrorReported) => {
- tcx.types.err
- }
- }
- }
- }
- ExprKind::Type(ref e, ref t) => {
- let ty = self.to_ty_saving_user_provided_ty(&t);
- self.check_expr_eq_type(&e, ty);
- ty
- }
- ExprKind::DropTemps(ref e) => {
- self.check_expr_with_expectation(e, expected)
- }
- ExprKind::Array(ref args) => {
- let uty = expected.to_option(self).and_then(|uty| {
- match uty.sty {
- ty::Array(ty, _) | ty::Slice(ty) => Some(ty),
- _ => None
- }
- });
-
- let element_ty = if !args.is_empty() {
- let coerce_to = uty.unwrap_or_else(|| {
- self.next_ty_var(TypeVariableOrigin {
- kind: TypeVariableOriginKind::TypeInference,
- span: expr.span,
- })
- });
- let mut coerce = CoerceMany::with_coercion_sites(coerce_to, args);
- assert_eq!(self.diverges.get(), Diverges::Maybe);
- for e in args {
- let e_ty = self.check_expr_with_hint(e, coerce_to);
- let cause = self.misc(e.span);
- coerce.coerce(self, &cause, e, e_ty);
- }
- coerce.complete(self)
- } else {
- self.next_ty_var(TypeVariableOrigin {
- kind: TypeVariableOriginKind::TypeInference,
- span: expr.span,
- })
- };
- tcx.mk_array(element_ty, args.len() as u64)
- }
- ExprKind::Repeat(ref element, ref count) => {
- let count_def_id = tcx.hir().local_def_id_from_hir_id(count.hir_id);
- let count = if self.const_param_def_id(count).is_some() {
- Ok(self.to_const(count, self.tcx.type_of(count_def_id)))
- } else {
- let param_env = ty::ParamEnv::empty();
- let substs = InternalSubsts::identity_for_item(tcx.global_tcx(), count_def_id);
- let instance = ty::Instance::resolve(
- tcx.global_tcx(),
- param_env,
- count_def_id,
- substs,
- ).unwrap();
- let global_id = GlobalId {
- instance,
- promoted: None
- };
-
- tcx.const_eval(param_env.and(global_id))
- };
-
- let uty = match expected {
- ExpectHasType(uty) => {
- match uty.sty {
- ty::Array(ty, _) | ty::Slice(ty) => Some(ty),
- _ => None
- }
- }
- _ => None
- };
-
- let (element_ty, t) = match uty {
- Some(uty) => {
- self.check_expr_coercable_to_type(&element, uty);
- (uty, uty)
- }
- None => {
- let ty = self.next_ty_var(TypeVariableOrigin {
- kind: TypeVariableOriginKind::MiscVariable,
- span: element.span,
- });
- let element_ty = self.check_expr_has_type_or_error(&element, ty);
- (element_ty, ty)
- }
- };
-
- if let Ok(count) = count {
- let zero_or_one = count.assert_usize(tcx).map_or(false, |count| count <= 1);
- if !zero_or_one {
- // For [foo, ..n] where n > 1, `foo` must have
- // Copy type:
- let lang_item = self.tcx.require_lang_item(lang_items::CopyTraitLangItem);
- self.require_type_meets(t, expr.span, traits::RepeatVec, lang_item);
- }
- }
-
- if element_ty.references_error() {
- tcx.types.err
- } else if let Ok(count) = count {
- tcx.mk_ty(ty::Array(t, count))
- } else {
- tcx.types.err
- }
- }
- ExprKind::Tup(ref elts) => {
- let flds = expected.only_has_type(self).and_then(|ty| {
- let ty = self.resolve_type_vars_with_obligations(ty);
- match ty.sty {
- ty::Tuple(ref flds) => Some(&flds[..]),
- _ => None
- }
- });
-
- let elt_ts_iter = elts.iter().enumerate().map(|(i, e)| {
- let t = match flds {
- Some(ref fs) if i < fs.len() => {
- let ety = fs[i].expect_ty();
- self.check_expr_coercable_to_type(&e, ety);
- ety
- }
- _ => {
- self.check_expr_with_expectation(&e, NoExpectation)
- }
- };
- t
- });
- let tuple = tcx.mk_tup(elt_ts_iter);
- if tuple.references_error() {
- tcx.types.err
- } else {
- self.require_type_is_sized(tuple, expr.span, traits::TupleInitializerSized);
- tuple
- }
- }
- ExprKind::Struct(ref qpath, ref fields, ref base_expr) => {
- self.check_expr_struct(expr, expected, qpath, fields, base_expr)
- }
- ExprKind::Field(ref base, field) => {
- self.check_field(expr, needs, &base, field)
- }
- ExprKind::Index(ref base, ref idx) => {
- let base_t = self.check_expr_with_needs(&base, needs);
- let idx_t = self.check_expr(&idx);
-
- if base_t.references_error() {
- base_t
- } else if idx_t.references_error() {
- idx_t
- } else {
- let base_t = self.structurally_resolved_type(base.span, base_t);
- match self.lookup_indexing(expr, base, base_t, idx_t, needs) {
- Some((index_ty, element_ty)) => {
- // two-phase not needed because index_ty is never mutable
- self.demand_coerce(idx, idx_t, index_ty, AllowTwoPhase::No);
- element_ty
- }
- None => {
- let mut err =
- type_error_struct!(tcx.sess, expr.span, base_t, E0608,
- "cannot index into a value of type `{}`",
- base_t);
- // Try to give some advice about indexing tuples.
- if let ty::Tuple(..) = base_t.sty {
- let mut needs_note = true;
- // If the index is an integer, we can show the actual
- // fixed expression:
- if let ExprKind::Lit(ref lit) = idx.node {
- if let ast::LitKind::Int(i,
- ast::LitIntType::Unsuffixed) = lit.node {
- let snip = tcx.sess.source_map().span_to_snippet(base.span);
- if let Ok(snip) = snip {
- err.span_suggestion(
- expr.span,
- "to access tuple elements, use",
- format!("{}.{}", snip, i),
- Applicability::MachineApplicable,
- );
- needs_note = false;
- }
- }
- }
- if needs_note {
- err.help("to access tuple elements, use tuple indexing \
- syntax (e.g., `tuple.0`)");
- }
- }
- err.emit();
- self.tcx.types.err
- }
- }
- }
- }
- ExprKind::Yield(ref value) => {
- match self.yield_ty {
- Some(ty) => {
- self.check_expr_coercable_to_type(&value, ty);
- }
- None => {
- struct_span_err!(self.tcx.sess, expr.span, E0627,
- "yield statement outside of generator literal").emit();
- }
- }
- tcx.mk_unit()
- }
- hir::ExprKind::Err => {
- tcx.types.err
- }
- }
- }
-
- /// Type check assignment expression `expr` of form `lhs = rhs`.
- /// The expected type is `()` and is passsed to the function for the purposes of diagnostics.
- fn check_assign(
- &self,
- expr: &'tcx hir::Expr,
- expected: Expectation<'tcx>,
- lhs: &'tcx hir::Expr,
- rhs: &'tcx hir::Expr,
- ) -> Ty<'tcx> {
- let lhs_ty = self.check_expr_with_needs(&lhs, Needs::MutPlace);
- let rhs_ty = self.check_expr_coercable_to_type(&rhs, lhs_ty);
-
- let expected_ty = expected.coercion_target_type(self, expr.span);
- if expected_ty == self.tcx.types.bool {
- // The expected type is `bool` but this will result in `()` so we can reasonably
- // say that the user intended to write `lhs == rhs` instead of `lhs = rhs`.
- // The likely cause of this is `if foo = bar { .. }`.
- let actual_ty = self.tcx.mk_unit();
- let mut err = self.demand_suptype_diag(expr.span, expected_ty, actual_ty).unwrap();
- let msg = "try comparing for equality";
- let left = self.tcx.sess.source_map().span_to_snippet(lhs.span);
- let right = self.tcx.sess.source_map().span_to_snippet(rhs.span);
- if let (Ok(left), Ok(right)) = (left, right) {
- let help = format!("{} == {}", left, right);
- err.span_suggestion(expr.span, msg, help, Applicability::MaybeIncorrect);
- } else {
- err.help(msg);
- }
- err.emit();
- } else if !lhs.is_place_expr() {
- struct_span_err!(self.tcx.sess, expr.span, E0070,
- "invalid left-hand side expression")
- .span_label(expr.span, "left-hand of expression not valid")
- .emit();
- }
-
- self.require_type_is_sized(lhs_ty, lhs.span, traits::AssignmentLhsSized);
-
- if lhs_ty.references_error() || rhs_ty.references_error() {
- self.tcx.types.err
- } else {
- self.tcx.mk_unit()
- }
- }
-
- // Finish resolving a path in a struct expression or pattern `S::A { .. }` if necessary.
- // The newly resolved definition is written into `type_dependent_defs`.
- fn finish_resolving_struct_path(&self,
- qpath: &QPath,
- path_span: Span,
- hir_id: hir::HirId)
- -> (Res, Ty<'tcx>)
- {
- match *qpath {
- QPath::Resolved(ref maybe_qself, ref path) => {
- let self_ty = maybe_qself.as_ref().map(|qself| self.to_ty(qself));
- let ty = AstConv::res_to_ty(self, self_ty, path, true);
- (path.res, ty)
- }
- QPath::TypeRelative(ref qself, ref segment) => {
- let ty = self.to_ty(qself);
-
- let res = if let hir::TyKind::Path(QPath::Resolved(_, ref path)) = qself.node {
- path.res
- } else {
- Res::Err
- };
- let result = AstConv::associated_path_to_ty(
- self,
- hir_id,
- path_span,
- ty,
- res,
- segment,
- true,
- );
- let ty = result.map(|(ty, _, _)| ty).unwrap_or(self.tcx().types.err);
- let result = result.map(|(_, kind, def_id)| (kind, def_id));
-
- // Write back the new resolution.
- self.write_resolution(hir_id, result);
-
- (result.map(|(kind, def_id)| Res::Def(kind, def_id)).unwrap_or(Res::Err), ty)
+ (result.map(|(kind, def_id)| Res::Def(kind, def_id)).unwrap_or(Res::Err), ty)
}
}
}
}
fn parent_item_span(&self, id: hir::HirId) -> Option<Span> {
- let node = self.tcx.hir().get_by_hir_id(self.tcx.hir().get_parent_item(id));
+ let node = self.tcx.hir().get(self.tcx.hir().get_parent_item(id));
match node {
Node::Item(&hir::Item {
node: hir::ItemKind::Fn(_, _, _, body_id), ..
}
/// Given a function block's `HirId`, returns its `FnDecl` if it exists, or `None` otherwise.
- fn get_parent_fn_decl(&self, blk_id: hir::HirId) -> Option<(hir::FnDecl, ast::Ident)> {
- let parent = self.tcx.hir().get_by_hir_id(self.tcx.hir().get_parent_item(blk_id));
+ fn get_parent_fn_decl(&self, blk_id: hir::HirId) -> Option<(&'tcx hir::FnDecl, ast::Ident)> {
+ let parent = self.tcx.hir().get(self.tcx.hir().get_parent_item(blk_id));
self.get_node_fn_decl(parent).map(|(fn_decl, ident, _)| (fn_decl, ident))
}
/// Given a function `Node`, return its `FnDecl` if it exists, or `None` otherwise.
- fn get_node_fn_decl(&self, node: Node<'_>) -> Option<(hir::FnDecl, ast::Ident, bool)> {
+ fn get_node_fn_decl(&self, node: Node<'tcx>) -> Option<(&'tcx hir::FnDecl, ast::Ident, bool)> {
match node {
Node::Item(&hir::Item {
ident, node: hir::ItemKind::Fn(ref decl, ..), ..
- }) => decl.clone().and_then(|decl| {
+ }) => {
// This is less than ideal, it will not suggest a return type span on any
// method called `main`, regardless of whether it is actually the entry point,
// but it will still present it as the reason for the expected type.
Some((decl, ident, ident.name != sym::main))
- }),
+ }
Node::TraitItem(&hir::TraitItem {
ident, node: hir::TraitItemKind::Method(hir::MethodSig {
ref decl, ..
}, ..), ..
- }) => decl.clone().and_then(|decl| Some((decl, ident, true))),
+ }) => Some((decl, ident, true)),
Node::ImplItem(&hir::ImplItem {
ident, node: hir::ImplItemKind::Method(hir::MethodSig {
ref decl, ..
}, ..), ..
- }) => decl.clone().and_then(|decl| Some((decl, ident, false))),
+ }) => Some((decl, ident, false)),
_ => None,
}
}
/// Given a `HirId`, return the `FnDecl` of the method it is enclosed by and whether a
/// suggestion can be made, `None` otherwise.
- pub fn get_fn_decl(&self, blk_id: hir::HirId) -> Option<(hir::FnDecl, bool)> {
+ pub fn get_fn_decl(&self, blk_id: hir::HirId) -> Option<(&'tcx hir::FnDecl, bool)> {
// Get enclosing Fn, if it is a function or a trait method, unless there's a `loop` or
// `while` before reaching it, as block tail returns are not available in them.
self.tcx.hir().get_return_block(blk_id).and_then(|blk_id| {
- let parent = self.tcx.hir().get_by_hir_id(blk_id);
+ let parent = self.tcx.hir().get(blk_id);
self.get_node_fn_decl(parent).map(|(fn_decl, _, is_main)| (fn_decl, is_main))
})
}
}
}
+ /// A possible error is to forget to add `.await` when using futures:
+ ///
+ /// ```
+ /// #![feature(async_await)]
+ ///
+ /// async fn make_u32() -> u32 {
+ /// 22
+ /// }
+ ///
+ /// fn take_u32(x: u32) {}
+ ///
+ /// async fn foo() {
+ /// let x = make_u32();
+ /// take_u32(x);
+ /// }
+ /// ```
+ ///
+ /// This routine checks if the found type `T` implements `Future<Output=U>` where `U` is the
+ /// expected type. If this is the case, and we are inside of an async body, it suggests adding
+ /// `.await` to the tail of the expression.
+ fn suggest_missing_await(
+ &self,
+ err: &mut DiagnosticBuilder<'tcx>,
+ expr: &hir::Expr,
+ expected: Ty<'tcx>,
+ found: Ty<'tcx>,
+ ) {
+ // `.await` is not permitted outside of `async` bodies, so don't bother to suggest if the
+ // body isn't `async`.
+ let item_id = self.tcx().hir().get_parent_node(self.body_id);
+ if let Some(body_id) = self.tcx().hir().maybe_body_owned_by(item_id) {
+ let body = self.tcx().hir().body(body_id);
+ if let Some(hir::GeneratorKind::Async) = body.generator_kind {
+ let sp = expr.span;
+ // Check for `Future` implementations by constructing a predicate to
+ // prove: `<T as Future>::Output == U`
+ let future_trait = self.tcx.lang_items().future_trait().unwrap();
+ let item_def_id = self.tcx.associated_items(future_trait).next().unwrap().def_id;
+ let predicate = ty::Predicate::Projection(ty::Binder::bind(ty::ProjectionPredicate {
+ // `<T as Future>::Output`
+ projection_ty: ty::ProjectionTy {
+ // `T`
+ substs: self.tcx.mk_substs_trait(
+ found,
+ self.fresh_substs_for_item(sp, item_def_id)
+ ),
+ // `Future::Output`
+ item_def_id,
+ },
+ ty: expected,
+ }));
+ let obligation = traits::Obligation::new(self.misc(sp), self.param_env, predicate);
+ if self.infcx.predicate_may_hold(&obligation) {
+ if let Ok(code) = self.sess().source_map().span_to_snippet(sp) {
+ err.span_suggestion(
+ sp,
+ "consider using `.await` here",
+ format!("{}.await", code),
+ Applicability::MaybeIncorrect,
+ );
+ }
+ }
+ }
+ }
+ }
+
/// A common error is to add an extra semicolon:
///
/// ```
Some(original_span.with_lo(original_span.hi() - BytePos(1)))
}
- // Rewrite `SelfCtor` to `Ctor`
- pub fn rewrite_self_ctor(
- &self,
- res: Res,
- span: Span,
- ) -> Result<Res, ErrorReported> {
- let tcx = self.tcx;
- if let Res::SelfCtor(impl_def_id) = res {
- let ty = self.impl_self_ty(span, impl_def_id).ty;
- let adt_def = ty.ty_adt_def();
-
- match adt_def {
- Some(adt_def) if adt_def.has_ctor() => {
- let variant = adt_def.non_enum_variant();
- let ctor_def_id = variant.ctor_def_id.unwrap();
- Ok(Res::Def(DefKind::Ctor(CtorOf::Struct, variant.ctor_kind), ctor_def_id))
- }
- _ => {
- let mut err = tcx.sess.struct_span_err(span,
- "the `Self` constructor can only be used with tuple or unit structs");
- if let Some(adt_def) = adt_def {
- match adt_def.adt_kind() {
- AdtKind::Enum => {
- err.help("did you mean to use one of the enum's variants?");
- },
- AdtKind::Struct |
- AdtKind::Union => {
- err.span_suggestion(
- span,
- "use curly brackets",
- String::from("Self { /* fields */ }"),
- Applicability::HasPlaceholders,
- );
- }
- }
- }
- err.emit();
-
- Err(ErrorReported)
- }
- }
- } else {
- Ok(res)
- }
- }
-
// Instantiates the given path, which must refer to an item with the given
// number of type parameters and type.
pub fn instantiate_value_path(&self,
let tcx = self.tcx;
- let res = match self.rewrite_self_ctor(res, span) {
- Ok(res) => res,
- Err(ErrorReported) => return (tcx.types.err, res),
- };
let path_segs = match res {
- Res::Local(_) => vec![],
+ Res::Local(_) | Res::SelfCtor(_) => vec![],
Res::Def(kind, def_id) =>
AstConv::def_ids_for_value_path_segments(self, segments, self_ty, kind, def_id),
_ => bug!("instantiate_value_path on {:?}", res),
tcx.generics_of(*def_id).has_self
}).unwrap_or(false);
+ let (res, self_ctor_substs) = if let Res::SelfCtor(impl_def_id) = res {
+ let ty = self.impl_self_ty(span, impl_def_id).ty;
+ let adt_def = ty.ty_adt_def();
+
+ match ty.sty {
+ ty::Adt(adt_def, substs) if adt_def.has_ctor() => {
+ let variant = adt_def.non_enum_variant();
+ let ctor_def_id = variant.ctor_def_id.unwrap();
+ (
+ Res::Def(DefKind::Ctor(CtorOf::Struct, variant.ctor_kind), ctor_def_id),
+ Some(substs),
+ )
+ }
+ _ => {
+ let mut err = tcx.sess.struct_span_err(span,
+ "the `Self` constructor can only be used with tuple or unit structs");
+ if let Some(adt_def) = adt_def {
+ match adt_def.adt_kind() {
+ AdtKind::Enum => {
+ err.help("did you mean to use one of the enum's variants?");
+ },
+ AdtKind::Struct |
+ AdtKind::Union => {
+ err.span_suggestion(
+ span,
+ "use curly brackets",
+ String::from("Self { /* fields */ }"),
+ Applicability::HasPlaceholders,
+ );
+ }
+ }
+ }
+ err.emit();
+
+ return (tcx.types.err, res)
+ }
+ }
+ } else {
+ (res, None)
+ };
let def_id = res.def_id();
// The things we are substituting into the type should not contain
// escaping late-bound regions, and nor should the base type scheme.
let ty = tcx.type_of(def_id);
- let substs = AstConv::create_substs_for_generic_args(
+ let substs = self_ctor_substs.unwrap_or_else(|| AstConv::create_substs_for_generic_args(
tcx,
def_id,
&[][..],
}
}
},
- );
+ ));
assert!(!substs.has_escaping_bound_vars());
assert!(!ty.has_escaping_bound_vars());
// If our calling expression is indeed the function itself, we're good!
// If not, generate an error that this can only be called directly.
- if let Node::Expr(expr) = self.tcx.hir().get_by_hir_id(
- self.tcx.hir().get_parent_node_by_hir_id(hir_id))
+ if let Node::Expr(expr) = self.tcx.hir().get(
+ self.tcx.hir().get_parent_node(hir_id))
{
if let ExprKind::Call(ref callee, ..) = expr.node {
if callee.hir_id == hir_id {
let mut contained_in_place = false;
while let hir::Node::Expr(parent_expr) =
- self.tcx.hir().get_by_hir_id(self.tcx.hir().get_parent_node_by_hir_id(expr_id))
+ self.tcx.hir().get(self.tcx.hir().get_parent_node(expr_id))
{
match &parent_expr.node {
hir::ExprKind::Assign(lhs, ..) | hir::ExprKind::AssignOp(_, lhs, ..) => {
} else if let ty::Error = leaf_ty.sty {
// If there is already another error, do not emit
// an error for not using a type Parameter.
- assert!(tcx.sess.err_count() > 0);
+ assert!(tcx.sess.has_errors());
return;
}
}
for (&used, param) in types_used.iter().zip(types) {
if !used {
let id = tcx.hir().as_local_hir_id(param.def_id).unwrap();
- let span = tcx.hir().span_by_hir_id(id);
+ let span = tcx.hir().span(id);
struct_span_err!(tcx.sess, span, E0091, "type parameter `{}` is unused", param.name)
.span_label(span, "unused type parameter")
.emit();