1 #![feature(if_let_guard)]
2 #![feature(let_chains)]
3 #![feature(try_blocks)]
4 #![feature(never_type)]
5 #![feature(min_specialization)]
6 #![feature(control_flow_enum)]
7 #![feature(drain_filter)]
8 #![allow(rustc::potential_query_instability)]
9 #![recursion_limit = "256"]
15 extern crate rustc_middle;
31 pub mod expr_use_visitor;
35 mod generator_interior;
38 mod mem_categorization;
47 pub use diverges::Diverges;
48 pub use expectation::Expectation;
50 pub use inherited::{Inherited, InheritedBuilder};
52 use crate::check::check_fn;
53 use crate::coercion::DynamicCoerceMany;
54 use crate::gather_locals::GatherLocalsVisitor;
55 use rustc_data_structures::fx::FxHashSet;
56 use rustc_errors::{struct_span_err, MultiSpan};
58 use rustc_hir::def::Res;
59 use rustc_hir::intravisit::Visitor;
60 use rustc_hir::{HirIdMap, Node};
61 use rustc_hir_analysis::astconv::AstConv;
62 use rustc_hir_analysis::check::check_abi;
63 use rustc_infer::infer::type_variable::{TypeVariableOrigin, TypeVariableOriginKind};
64 use rustc_middle::traits;
65 use rustc_middle::ty::query::Providers;
66 use rustc_middle::ty::{self, Ty, TyCtxt};
67 use rustc_session::config;
68 use rustc_session::Session;
69 use rustc_span::def_id::{DefId, LocalDefId};
73 macro_rules! type_error_struct {
74 ($session:expr, $span:expr, $typ:expr, $code:ident, $($message:tt)*) => ({
75 let mut err = rustc_errors::struct_span_err!($session, $span, $code, $($message)*);
77 if $typ.references_error() {
78 err.downgrade_to_delayed_bug();
85 /// The type of a local binding, including the revealed type for anon types.
86 #[derive(Copy, Clone, Debug)]
87 pub struct LocalTy<'tcx> {
89 revealed_ty: Ty<'tcx>,
92 #[derive(Copy, Clone)]
93 pub struct UnsafetyState {
95 pub unsafety: hir::Unsafety,
100 pub fn function(unsafety: hir::Unsafety, def: hir::HirId) -> UnsafetyState {
101 UnsafetyState { def, unsafety, from_fn: true }
104 pub fn recurse(self, blk: &hir::Block<'_>) -> UnsafetyState {
105 use hir::BlockCheckMode;
106 match self.unsafety {
107 // If this unsafe, then if the outer function was already marked as
108 // unsafe we shouldn't attribute the unsafe'ness to the block. This
109 // way the block can be warned about instead of ignoring this
110 // extraneous block (functions are never warned about).
111 hir::Unsafety::Unsafe if self.from_fn => self,
114 let (unsafety, def) = match blk.rules {
115 BlockCheckMode::UnsafeBlock(..) => (hir::Unsafety::Unsafe, blk.hir_id),
116 BlockCheckMode::DefaultBlock => (unsafety, self.def),
118 UnsafetyState { def, unsafety, from_fn: false }
124 /// If this `DefId` is a "primary tables entry", returns
125 /// `Some((body_id, body_ty, fn_sig))`. Otherwise, returns `None`.
127 /// If this function returns `Some`, then `typeck_results(def_id)` will
128 /// succeed; if it returns `None`, then `typeck_results(def_id)` may or
129 /// may not succeed. In some cases where this function returns `None`
130 /// (notably closures), `typeck_results(def_id)` would wind up
131 /// redirecting to the owning function.
135 ) -> Option<(hir::BodyId, Option<&hir::Ty<'_>>, Option<&hir::FnSig<'_>>)> {
136 match tcx.hir().get(id) {
137 Node::Item(item) => match item.kind {
138 hir::ItemKind::Const(ty, body) | hir::ItemKind::Static(ty, _, body) => {
139 Some((body, Some(ty), None))
141 hir::ItemKind::Fn(ref sig, .., body) => Some((body, None, Some(sig))),
144 Node::TraitItem(item) => match item.kind {
145 hir::TraitItemKind::Const(ty, Some(body)) => Some((body, Some(ty), None)),
146 hir::TraitItemKind::Fn(ref sig, hir::TraitFn::Provided(body)) => {
147 Some((body, None, Some(sig)))
151 Node::ImplItem(item) => match item.kind {
152 hir::ImplItemKind::Const(ty, body) => Some((body, Some(ty), None)),
153 hir::ImplItemKind::Fn(ref sig, body) => Some((body, None, Some(sig))),
156 Node::AnonConst(constant) => Some((constant.body, None, None)),
161 fn has_typeck_results(tcx: TyCtxt<'_>, def_id: DefId) -> bool {
162 // Closures' typeck results come from their outermost function,
163 // as they are part of the same "inference environment".
164 let typeck_root_def_id = tcx.typeck_root_def_id(def_id);
165 if typeck_root_def_id != def_id {
166 return tcx.has_typeck_results(typeck_root_def_id);
169 if let Some(def_id) = def_id.as_local() {
170 let id = tcx.hir().local_def_id_to_hir_id(def_id);
171 primary_body_of(tcx, id).is_some()
177 fn used_trait_imports(tcx: TyCtxt<'_>, def_id: LocalDefId) -> &FxHashSet<LocalDefId> {
178 &*tcx.typeck(def_id).used_trait_imports
181 fn typeck_item_bodies(tcx: TyCtxt<'_>, (): ()) {
182 tcx.hir().par_body_owners(|body_owner_def_id| tcx.ensure().typeck(body_owner_def_id));
185 fn typeck_const_arg<'tcx>(
187 (did, param_did): (LocalDefId, DefId),
188 ) -> &ty::TypeckResults<'tcx> {
189 let fallback = move || tcx.type_of(param_did);
190 typeck_with_fallback(tcx, did, fallback)
193 fn typeck<'tcx>(tcx: TyCtxt<'tcx>, def_id: LocalDefId) -> &ty::TypeckResults<'tcx> {
194 if let Some(param_did) = tcx.opt_const_param_of(def_id) {
195 tcx.typeck_const_arg((def_id, param_did))
197 let fallback = move || tcx.type_of(def_id.to_def_id());
198 typeck_with_fallback(tcx, def_id, fallback)
202 /// Used only to get `TypeckResults` for type inference during error recovery.
203 /// Currently only used for type inference of `static`s and `const`s to avoid type cycle errors.
204 fn diagnostic_only_typeck<'tcx>(tcx: TyCtxt<'tcx>, def_id: LocalDefId) -> &ty::TypeckResults<'tcx> {
205 let fallback = move || {
206 let span = tcx.hir().span(tcx.hir().local_def_id_to_hir_id(def_id));
207 tcx.ty_error_with_message(span, "diagnostic only typeck table used")
209 typeck_with_fallback(tcx, def_id, fallback)
212 fn typeck_with_fallback<'tcx>(
215 fallback: impl Fn() -> Ty<'tcx> + 'tcx,
216 ) -> &'tcx ty::TypeckResults<'tcx> {
217 // Closures' typeck results come from their outermost function,
218 // as they are part of the same "inference environment".
219 let typeck_root_def_id = tcx.typeck_root_def_id(def_id.to_def_id()).expect_local();
220 if typeck_root_def_id != def_id {
221 return tcx.typeck(typeck_root_def_id);
224 let id = tcx.hir().local_def_id_to_hir_id(def_id);
225 let span = tcx.hir().span(id);
227 // Figure out what primary body this item has.
228 let (body_id, body_ty, fn_sig) = primary_body_of(tcx, id).unwrap_or_else(|| {
229 span_bug!(span, "can't type-check body of {:?}", def_id);
231 let body = tcx.hir().body(body_id);
233 let typeck_results = Inherited::build(tcx, def_id).enter(|inh| {
234 let param_env = tcx.param_env(def_id);
235 let mut fcx = if let Some(hir::FnSig { header, decl, .. }) = fn_sig {
236 let fn_sig = if rustc_hir_analysis::collect::get_infer_ret_ty(&decl.output).is_some() {
237 let fcx = FnCtxt::new(&inh, param_env, body.value.hir_id);
238 <dyn AstConv<'_>>::ty_of_fn(&fcx, id, header.unsafety, header.abi, decl, None, None)
243 check_abi(tcx, id, span, fn_sig.abi());
245 // Compute the function signature from point of view of inside the fn.
246 let fn_sig = tcx.liberate_late_bound_regions(def_id.to_def_id(), fn_sig);
247 let fn_sig = inh.normalize_associated_types_in(
253 check_fn(&inh, param_env, fn_sig, decl, id, body, None, true).0
255 let fcx = FnCtxt::new(&inh, param_env, body.value.hir_id);
256 let expected_type = body_ty
257 .and_then(|ty| match ty.kind {
258 hir::TyKind::Infer => Some(<dyn AstConv<'_>>::ast_ty_to_ty(&fcx, ty)),
261 .unwrap_or_else(|| match tcx.hir().get(id) {
262 Node::AnonConst(_) => match tcx.hir().get(tcx.hir().get_parent_node(id)) {
263 Node::Expr(&hir::Expr {
264 kind: hir::ExprKind::ConstBlock(ref anon_const),
266 }) if anon_const.hir_id == id => fcx.next_ty_var(TypeVariableOrigin {
267 kind: TypeVariableOriginKind::TypeInference,
271 kind: hir::TyKind::Typeof(ref anon_const), ..
272 }) if anon_const.hir_id == id => fcx.next_ty_var(TypeVariableOrigin {
273 kind: TypeVariableOriginKind::TypeInference,
276 Node::Expr(&hir::Expr { kind: hir::ExprKind::InlineAsm(asm), .. })
277 | Node::Item(&hir::Item { kind: hir::ItemKind::GlobalAsm(asm), .. }) => {
281 .filter_map(|(op, _op_sp)| match op {
282 hir::InlineAsmOperand::Const { anon_const }
283 if anon_const.hir_id == id =>
285 // Inline assembly constants must be integers.
286 Some(fcx.next_int_var())
288 hir::InlineAsmOperand::SymFn { anon_const }
289 if anon_const.hir_id == id =>
291 Some(fcx.next_ty_var(TypeVariableOrigin {
292 kind: TypeVariableOriginKind::MiscVariable,
299 operand_ty.unwrap_or_else(fallback)
306 let expected_type = fcx.normalize_associated_types_in(body.value.span, expected_type);
307 fcx.require_type_is_sized(expected_type, body.value.span, traits::ConstSized);
309 // Gather locals in statics (because of block expressions).
310 GatherLocalsVisitor::new(&fcx).visit_body(body);
312 fcx.check_expr_coercable_to_type(&body.value, expected_type, None);
314 fcx.write_ty(id, expected_type);
319 let fallback_has_occurred = fcx.type_inference_fallback();
321 // Even though coercion casts provide type hints, we check casts after fallback for
322 // backwards compatibility. This makes fallback a stronger type hint than a cast coercion.
324 fcx.select_obligations_where_possible(fallback_has_occurred, |_| {});
326 // Closure and generator analysis may run after fallback
327 // because they don't constrain other type variables.
328 // Closure analysis only runs on closures. Therefore they only need to fulfill non-const predicates (as of now)
329 let prev_constness = fcx.param_env.constness();
330 fcx.param_env = fcx.param_env.without_const();
331 fcx.closure_analyze(body);
332 fcx.param_env = fcx.param_env.with_constness(prev_constness);
333 assert!(fcx.deferred_call_resolutions.borrow().is_empty());
334 // Before the generator analysis, temporary scopes shall be marked to provide more
335 // precise information on types to be captured.
336 fcx.resolve_rvalue_scopes(def_id.to_def_id());
337 fcx.resolve_generator_interiors(def_id.to_def_id());
339 for (ty, span, code) in fcx.deferred_sized_obligations.borrow_mut().drain(..) {
340 let ty = fcx.normalize_ty(span, ty);
341 fcx.require_type_is_sized(ty, span, code);
344 fcx.select_all_obligations_or_error();
346 if !fcx.infcx.is_tainted_by_errors() {
347 fcx.check_transmutes();
352 fcx.infcx.skip_region_resolution();
354 fcx.resolve_type_vars_in_body(body)
357 // Consistency check our TypeckResults instance can hold all ItemLocalIds
358 // it will need to hold.
359 assert_eq!(typeck_results.hir_owner, id.owner);
364 /// When `check_fn` is invoked on a generator (i.e., a body that
365 /// includes yield), it returns back some information about the yield
367 struct GeneratorTypes<'tcx> {
368 /// Type of generator argument / values returned by `yield`.
371 /// Type of value that is yielded.
374 /// Types that are captured (see `GeneratorInterior` for more).
377 /// Indicates if the generator is movable or static (immovable).
378 movability: hir::Movability,
381 #[derive(Copy, Clone, Debug, PartialEq, Eq)]
388 fn maybe_mut_place(m: hir::Mutability) -> Self {
390 hir::Mutability::Mut => Needs::MutPlace,
391 hir::Mutability::Not => Needs::None,
396 #[derive(Debug, Copy, Clone)]
402 pub struct BreakableCtxt<'tcx> {
405 // this is `null` for loops where break with a value is illegal,
406 // such as `while`, `for`, and `while let`
407 coerce: Option<DynamicCoerceMany<'tcx>>,
410 pub struct EnclosingBreakables<'tcx> {
411 stack: Vec<BreakableCtxt<'tcx>>,
412 by_id: HirIdMap<usize>,
415 impl<'tcx> EnclosingBreakables<'tcx> {
416 fn find_breakable(&mut self, target_id: hir::HirId) -> &mut BreakableCtxt<'tcx> {
417 self.opt_find_breakable(target_id).unwrap_or_else(|| {
418 bug!("could not find enclosing breakable with id {}", target_id);
422 fn opt_find_breakable(&mut self, target_id: hir::HirId) -> Option<&mut BreakableCtxt<'tcx>> {
423 match self.by_id.get(&target_id) {
424 Some(ix) => Some(&mut self.stack[*ix]),
430 fn report_unexpected_variant_res(tcx: TyCtxt<'_>, res: Res, qpath: &hir::QPath<'_>, span: Span) {
435 "expected unit struct, unit variant or constant, found {} `{}`",
437 rustc_hir_pretty::qpath_to_string(qpath),
442 /// Controls whether the arguments are tupled. This is used for the call
445 /// Tupling means that all call-side arguments are packed into a tuple and
446 /// passed as a single parameter. For example, if tupling is enabled, this
449 /// fn f(x: (isize, isize)) {}
451 /// Can be called as:
452 /// ```ignore UNSOLVED (can this be done in user code?)
453 /// # fn f(x: (isize, isize)) {}
458 /// # fn f(x: (isize, isize)) {}
461 #[derive(Clone, Eq, PartialEq)]
462 enum TupleArgumentsFlag {
467 fn fatally_break_rust(sess: &Session) {
468 let handler = sess.diagnostic();
469 handler.span_bug_no_panic(
471 "It looks like you're trying to break rust; would you like some ICE?",
473 handler.note_without_error("the compiler expectedly panicked. this is a feature.");
474 handler.note_without_error(
475 "we would appreciate a joke overview: \
476 https://github.com/rust-lang/rust/issues/43162#issuecomment-320764675",
478 handler.note_without_error(&format!(
479 "rustc {} running on {}",
480 option_env!("CFG_VERSION").unwrap_or("unknown_version"),
481 config::host_triple(),
485 fn has_expected_num_generic_args<'tcx>(
487 trait_did: Option<DefId>,
490 trait_did.map_or(true, |trait_did| {
491 let generics = tcx.generics_of(trait_did);
492 generics.count() == expected + if generics.has_self { 1 } else { 0 }
496 pub fn provide(providers: &mut Providers) {
497 method::provide(providers);
498 *providers = Providers {
502 diagnostic_only_typeck,