X-Git-Url: https://git.lizzy.rs/?a=blobdiff_plain;f=src%2Flibrustc_typeck%2Fcheck%2Fmod.rs;h=fe742a74fffec7e49f35590cc07d05bb3a06e297;hb=e8a88f7d4330c62bc039c21831894c2758a43e60;hp=c857eac5d3c18fa5bc0bcacc086961d322291991;hpb=9f8cd9da7b6380b5658163141c767a321f5f0f62;p=rust.git diff --git a/src/librustc_typeck/check/mod.rs b/src/librustc_typeck/check/mod.rs index c857eac5d3c..fb7d681a72d 100644 --- a/src/librustc_typeck/check/mod.rs +++ b/src/librustc_typeck/check/mod.rs @@ -74,6 +74,7 @@ mod regionck; pub mod coercion; pub mod demand; +mod expr; pub mod method; mod upvar; mod wfcheck; @@ -88,10 +89,11 @@ 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}; @@ -105,7 +107,7 @@ 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::{ @@ -121,15 +123,12 @@ 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}; @@ -142,7 +141,7 @@ 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; @@ -161,7 +160,7 @@ pub struct LocalTy<'tcx> { /// 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>>, } @@ -194,7 +193,7 @@ fn borrow_mut(self) -> RefMut<'a, 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>, @@ -218,7 +217,7 @@ pub struct Inherited<'a, 'tcx: 'a> { deferred_cast_checks: RefCell>>, - deferred_generator_interiors: RefCell)>>, + deferred_generator_interiors: RefCell, hir::GeneratorKind)>>, // Opaque types found in explicit return types and their // associated fresh inference variable. Writeback resolves these @@ -513,7 +512,7 @@ fn find_breakable(&mut self, target_id: hir::HirId) -> &mut BreakableCtxt<'tcx> } } -pub struct FnCtxt<'a, 'tcx: 'a> { +pub struct FnCtxt<'a, 'tcx> { body_id: hir::HirId, /// The parameter environment used for proving trait obligations @@ -528,6 +527,8 @@ pub struct FnCtxt<'a, 'tcx: 'a> { /// 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>>, @@ -623,7 +624,7 @@ impl Inherited<'a, '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 { @@ -697,33 +698,31 @@ fn visit_trait_item(&mut self, _: &'tcx hir::TraitItem) { } 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); } @@ -743,7 +742,7 @@ pub fn provide(providers: &mut Providers<'_>) { }; } -fn adt_destructor<'tcx>(tcx: TyCtxt<'tcx>, def_id: DefId) -> Option { +fn adt_destructor(tcx: TyCtxt<'_>, def_id: DefId) -> Option { tcx.calculate_dtor(def_id, &mut dropck::check_drop_impl) } @@ -756,11 +755,11 @@ fn adt_destructor<'tcx>(tcx: TyCtxt<'tcx>, def_id: DefId) -> Option( - 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) | @@ -797,7 +796,7 @@ fn primary_body_of<'tcx>( } } -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); @@ -809,11 +808,11 @@ fn has_typeck_tables<'tcx>(tcx: TyCtxt<'tcx>, def_id: DefId) -> bool { 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); @@ -822,7 +821,7 @@ fn typeck_tables_of<'tcx>(tcx: TyCtxt<'tcx>, def_id: DefId) -> &'tcx ty::TypeckT } 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(|| { @@ -857,7 +856,8 @@ fn typeck_tables_of<'tcx>(tcx: TyCtxt<'tcx>, def_id: DefId) -> &'tcx ty::TypeckT 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 @@ -913,14 +913,14 @@ fn typeck_tables_of<'tcx>(tcx: TyCtxt<'tcx>, def_id: DefId) -> &'tcx ty::TypeckT 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, } @@ -963,7 +963,8 @@ fn visit_local(&mut self, local: &'tcx hir::Local) { 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 @@ -994,10 +995,9 @@ fn visit_pat(&mut self, p: &'tcx hir::Pat) { 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 {:?}", @@ -1060,7 +1060,11 @@ fn check_fn<'a, 'tcx>( 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(), @@ -1072,7 +1076,7 @@ fn check_fn<'a, 'tcx>( 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, @@ -1109,12 +1113,12 @@ fn check_fn<'a, 'tcx>( // 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, @@ -1194,7 +1198,7 @@ fn check_fn<'a, 'tcx>( } 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 { @@ -1215,7 +1219,7 @@ fn check_fn<'a, 'tcx>( ); } - 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( @@ -1247,7 +1251,7 @@ fn check_fn<'a, 'tcx>( } 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, _) => { @@ -1263,7 +1267,7 @@ fn check_fn<'a, 'tcx>( ); } - 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( @@ -1287,7 +1291,7 @@ fn check_fn<'a, 'tcx>( (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 @@ -1301,7 +1305,7 @@ fn check_struct<'tcx>(tcx: TyCtxt<'tcx>, id: hir::HirId, span: Span) { 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 @@ -1449,8 +1453,8 @@ fn maybe_check_static_with_link_section(tcx: TyCtxt<'_>, id: DefId, span: Span) }; 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") }; @@ -1463,14 +1467,14 @@ fn maybe_check_static_with_link_section(tcx: TyCtxt<'_>, id: DefId, span: Span) } } -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, ) { @@ -1686,7 +1690,7 @@ fn check_impl_items_against_trait<'tcx>( /// 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 @@ -1708,7 +1712,7 @@ fn check_representable<'tcx>(tcx: TyCtxt<'tcx>, sp: Span, item_def_id: DefId) -> 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() { @@ -1737,7 +1741,7 @@ pub fn check_simd<'tcx>(tcx: TyCtxt<'tcx>, sp: Span, def_id: DefId) { } } -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() { @@ -1761,7 +1765,7 @@ fn check_packed<'tcx>(tcx: TyCtxt<'tcx>, sp: Span, def_id: DefId) { } } -fn check_packed_inner<'tcx>(tcx: TyCtxt<'tcx>, def_id: DefId, stack: &mut Vec) -> bool { +fn check_packed_inner(tcx: TyCtxt<'_>, def_id: DefId, stack: &mut Vec) -> bool { let t = tcx.type_of(def_id); if stack.contains(&def_id) { debug!("check_packed_inner: {:?} is recursive", t); @@ -1789,32 +1793,71 @@ fn check_packed_inner<'tcx>(tcx: TyCtxt<'tcx>, def_id: DefId, stack: &mut Vec(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, + 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; @@ -1842,28 +1885,24 @@ fn check_transparent<'tcx>(tcx: TyCtxt<'tcx>, sp: Span, def_id: DefId) { (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(); } } } @@ -1902,6 +1941,25 @@ pub fn check_enum<'tcx>(tcx: TyCtxt<'tcx>, sp: Span, vs: &'tcx [hir::Variant], i } } + 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> = Vec::with_capacity(vs.len()); for ((_, discr), v) in def.discriminants(tcx).zip(vs) { // Check for duplicate discriminant values @@ -1910,11 +1968,11 @@ pub fn check_enum<'tcx>(tcx: TyCtxt<'tcx>, sp: Span, vs: &'tcx [hir::Variant], i 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, @@ -1930,7 +1988,7 @@ pub fn check_enum<'tcx>(tcx: TyCtxt<'tcx>, sp: Span, vs: &'tcx [hir::Variant], i 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(), @@ -2095,8 +2153,8 @@ pub fn sess(&self) -> &Session { &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 @@ -2182,7 +2240,7 @@ pub fn tag(&self) -> String { 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)) ) } @@ -2393,6 +2451,7 @@ fn instantiate_opaque_types_from_value>( &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={:?})", @@ -2405,6 +2464,7 @@ fn instantiate_opaque_types_from_value>( self.body_id, self.param_env, value, + value_span, ) ); @@ -2518,9 +2578,8 @@ pub fn node_ty(&self, id: hir::HirId) -> Ty<'tcx> { 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()); } } @@ -2600,9 +2659,9 @@ fn check_casts(&self) { 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); } } @@ -3196,82 +3255,6 @@ fn check_lit(&self, } } - 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 for Vec<(A,B)>` // would return `($0, $1)` where `$0` and `$1` are freshly instantiated type @@ -3341,470 +3324,6 @@ fn expected_inputs_for_expected_output(&self, 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::() { - 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::() - ) { - 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) - -> Option { - 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 { - 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) -> 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::>().join(", "); - if names.len() > limit { - display = format!("{} ... and {} others", display, names.len() - limit); - } - display - } - - fn no_such_field_err(&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::>(); - - 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::>(); - - 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::>() - .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>, - ) { - 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) @@ -3863,885 +3382,49 @@ pub fn check_struct_path(&self, } } - fn check_expr_struct( - &self, - expr: &hir::Expr, - expected: Expectation<'tcx>, - qpath: &QPath, - fields: &'tcx [hir::Field], - base_expr: &'tcx Option>, - ) -> 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 + (result.map(|(kind, def_id)| Res::Def(kind, def_id)).unwrap_or(Res::Err), ty) } } } - /// 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) - } - } - } - - /// Resolves associated value path into a base type and associated constant or method + /// Resolves an associated value path into a base type and associated constant, or method /// resolution. The newly resolved definition is written into `type_dependent_defs`. pub fn resolve_ty_and_res_ufcs<'b>(&self, qpath: &'b QPath, @@ -5020,7 +3703,7 @@ fn check_block_with_expected( } fn parent_item_span(&self, id: hir::HirId) -> Option { - 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), .. @@ -5039,43 +3722,43 @@ fn parent_item_span(&self, id: hir::HirId) -> Option { } /// 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)) }) } @@ -5257,6 +3940,72 @@ fn suggest_missing_return_type( } } + /// 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` 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: `::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 { + // `::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: /// /// ``` @@ -5300,52 +4049,6 @@ fn could_remove_semicolon(&self, blk: &'tcx hir::Block, expected_ty: Ty<'tcx>) - 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 { - 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, @@ -5365,12 +4068,8 @@ 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), @@ -5475,13 +4174,53 @@ pub fn instantiate_value_path(&self, 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, &[][..], @@ -5551,7 +4290,7 @@ pub fn instantiate_value_path(&self, } } }, - ); + )); assert!(!substs.has_escaping_bound_vars()); assert!(!ty.has_escaping_bound_vars()); @@ -5612,8 +4351,8 @@ fn check_rustc_args_require_const(&self, // 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 { @@ -5688,7 +4427,7 @@ fn expr_in_place(&self, mut expr_id: hir::HirId) -> bool { 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, ..) => { @@ -5729,7 +4468,7 @@ pub fn check_bounds_are_used<'tcx>(tcx: TyCtxt<'tcx>, generics: &ty::Generics, t } 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; } } @@ -5741,7 +4480,7 @@ pub fn check_bounds_are_used<'tcx>(tcx: TyCtxt<'tcx>, generics: &ty::Generics, t 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();