| //! A pass that annotates every item and method with its stability level, |
| //! propagating default levels lexically from parent to children ast nodes. |
| |
| pub use self::StabilityLevel::*; |
| |
| use crate::lint::{self, Lint, in_derive_expansion}; |
| use crate::lint::builtin::BuiltinLintDiagnostics; |
| use crate::hir::{self, Item, Generics, StructField, Variant, HirId}; |
| use crate::hir::def::{Res, DefKind}; |
| use crate::hir::def_id::{CrateNum, CRATE_DEF_INDEX, DefId, LOCAL_CRATE}; |
| use crate::hir::intravisit::{self, Visitor, NestedVisitorMap}; |
| use crate::ty::query::Providers; |
| use crate::middle::privacy::AccessLevels; |
| use crate::session::{DiagnosticMessageId, Session}; |
| use errors::DiagnosticBuilder; |
| use syntax::symbol::{Symbol, sym}; |
| use syntax_pos::{Span, MultiSpan}; |
| use syntax::ast::{Attribute, CRATE_NODE_ID}; |
| use syntax::errors::Applicability; |
| use syntax::feature_gate::{GateIssue, emit_feature_err}; |
| use syntax::attr::{self, Stability, Deprecation, RustcDeprecation}; |
| use crate::ty::{self, TyCtxt}; |
| use crate::util::nodemap::{FxHashSet, FxHashMap}; |
| |
| use std::mem::replace; |
| use std::cmp::Ordering; |
| |
| #[derive(RustcEncodable, RustcDecodable, PartialEq, PartialOrd, Clone, Copy, Debug, Eq, Hash)] |
| pub enum StabilityLevel { |
| Unstable, |
| Stable, |
| } |
| |
| impl StabilityLevel { |
| pub fn from_attr_level(level: &attr::StabilityLevel) -> Self { |
| if level.is_stable() { Stable } else { Unstable } |
| } |
| } |
| |
| #[derive(PartialEq)] |
| enum AnnotationKind { |
| // Annotation is required if not inherited from unstable parents |
| Required, |
| // Annotation is useless, reject it |
| Prohibited, |
| // Annotation itself is useless, but it can be propagated to children |
| Container, |
| } |
| |
| /// An entry in the `depr_map`. |
| #[derive(Clone)] |
| pub struct DeprecationEntry { |
| /// The metadata of the attribute associated with this entry. |
| pub attr: Deprecation, |
| /// The `DefId` where the attr was originally attached. `None` for non-local |
| /// `DefId`'s. |
| origin: Option<HirId>, |
| } |
| |
| impl_stable_hash_for!(struct self::DeprecationEntry { |
| attr, |
| origin |
| }); |
| |
| impl DeprecationEntry { |
| fn local(attr: Deprecation, id: HirId) -> DeprecationEntry { |
| DeprecationEntry { |
| attr, |
| origin: Some(id), |
| } |
| } |
| |
| pub fn external(attr: Deprecation) -> DeprecationEntry { |
| DeprecationEntry { |
| attr, |
| origin: None, |
| } |
| } |
| |
| pub fn same_origin(&self, other: &DeprecationEntry) -> bool { |
| match (self.origin, other.origin) { |
| (Some(o1), Some(o2)) => o1 == o2, |
| _ => false |
| } |
| } |
| } |
| |
| /// A stability index, giving the stability level for items and methods. |
| pub struct Index<'tcx> { |
| /// This is mostly a cache, except the stabilities of local items |
| /// are filled by the annotator. |
| stab_map: FxHashMap<HirId, &'tcx Stability>, |
| depr_map: FxHashMap<HirId, DeprecationEntry>, |
| |
| /// Maps for each crate whether it is part of the staged API. |
| staged_api: FxHashMap<CrateNum, bool>, |
| |
| /// Features enabled for this crate. |
| active_features: FxHashSet<Symbol>, |
| } |
| |
| impl_stable_hash_for!(struct self::Index<'tcx> { |
| stab_map, |
| depr_map, |
| staged_api, |
| active_features |
| }); |
| |
| // A private tree-walker for producing an Index. |
| struct Annotator<'a, 'tcx> { |
| tcx: TyCtxt<'tcx>, |
| index: &'a mut Index<'tcx>, |
| parent_stab: Option<&'tcx Stability>, |
| parent_depr: Option<DeprecationEntry>, |
| in_trait_impl: bool, |
| } |
| |
| impl<'a, 'tcx> Annotator<'a, 'tcx> { |
| // Determine the stability for a node based on its attributes and inherited |
| // stability. The stability is recorded in the index and used as the parent. |
| fn annotate<F>(&mut self, hir_id: HirId, attrs: &[Attribute], |
| item_sp: Span, kind: AnnotationKind, visit_children: F) |
| where F: FnOnce(&mut Self) |
| { |
| if self.tcx.features().staged_api { |
| // This crate explicitly wants staged API. |
| debug!("annotate(id = {:?}, attrs = {:?})", hir_id, attrs); |
| if let Some(..) = attr::find_deprecation(&self.tcx.sess.parse_sess, attrs, item_sp) { |
| self.tcx.sess.span_err(item_sp, "`#[deprecated]` cannot be used in staged API; \ |
| use `#[rustc_deprecated]` instead"); |
| } |
| if let Some(mut stab) = attr::find_stability(&self.tcx.sess.parse_sess, |
| attrs, item_sp) { |
| // Error if prohibited, or can't inherit anything from a container. |
| if kind == AnnotationKind::Prohibited || |
| (kind == AnnotationKind::Container && |
| stab.level.is_stable() && |
| stab.rustc_depr.is_none()) { |
| self.tcx.sess.span_err(item_sp, "This stability annotation is useless"); |
| } |
| |
| debug!("annotate: found {:?}", stab); |
| // If parent is deprecated and we're not, inherit this by merging |
| // deprecated_since and its reason. |
| if let Some(parent_stab) = self.parent_stab { |
| if parent_stab.rustc_depr.is_some() && stab.rustc_depr.is_none() { |
| stab.rustc_depr = parent_stab.rustc_depr.clone() |
| } |
| } |
| |
| let stab = self.tcx.intern_stability(stab); |
| |
| // Check if deprecated_since < stable_since. If it is, |
| // this is *almost surely* an accident. |
| if let (&Some(attr::RustcDeprecation {since: dep_since, ..}), |
| &attr::Stable {since: stab_since}) = (&stab.rustc_depr, &stab.level) { |
| // Explicit version of iter::order::lt to handle parse errors properly |
| for (dep_v, stab_v) in dep_since.as_str() |
| .split('.') |
| .zip(stab_since.as_str().split('.')) |
| { |
| if let (Ok(dep_v), Ok(stab_v)) = (dep_v.parse::<u64>(), stab_v.parse()) { |
| match dep_v.cmp(&stab_v) { |
| Ordering::Less => { |
| self.tcx.sess.span_err(item_sp, "An API can't be stabilized \ |
| after it is deprecated"); |
| break |
| } |
| Ordering::Equal => continue, |
| Ordering::Greater => break, |
| } |
| } else { |
| // Act like it isn't less because the question is now nonsensical, |
| // and this makes us not do anything else interesting. |
| self.tcx.sess.span_err(item_sp, "Invalid stability or deprecation \ |
| version found"); |
| break |
| } |
| } |
| } |
| |
| self.index.stab_map.insert(hir_id, stab); |
| |
| let orig_parent_stab = replace(&mut self.parent_stab, Some(stab)); |
| visit_children(self); |
| self.parent_stab = orig_parent_stab; |
| } else { |
| debug!("annotate: not found, parent = {:?}", self.parent_stab); |
| if let Some(stab) = self.parent_stab { |
| if stab.level.is_unstable() { |
| self.index.stab_map.insert(hir_id, stab); |
| } |
| } |
| visit_children(self); |
| } |
| } else { |
| // Emit errors for non-staged-api crates. |
| for attr in attrs { |
| let name = attr.name_or_empty(); |
| if [sym::unstable, sym::stable, sym::rustc_deprecated].contains(&name) { |
| attr::mark_used(attr); |
| self.tcx.sess.span_err(attr.span, "stability attributes may not be used \ |
| outside of the standard library"); |
| } |
| } |
| |
| // Propagate unstability. This can happen even for non-staged-api crates in case |
| // -Zforce-unstable-if-unmarked is set. |
| if let Some(stab) = self.parent_stab { |
| if stab.level.is_unstable() { |
| self.index.stab_map.insert(hir_id, stab); |
| } |
| } |
| |
| if let Some(depr) = attr::find_deprecation(&self.tcx.sess.parse_sess, attrs, item_sp) { |
| if kind == AnnotationKind::Prohibited { |
| self.tcx.sess.span_err(item_sp, "This deprecation annotation is useless"); |
| } |
| |
| // `Deprecation` is just two pointers, no need to intern it |
| let depr_entry = DeprecationEntry::local(depr, hir_id); |
| self.index.depr_map.insert(hir_id, depr_entry.clone()); |
| |
| let orig_parent_depr = replace(&mut self.parent_depr, |
| Some(depr_entry)); |
| visit_children(self); |
| self.parent_depr = orig_parent_depr; |
| } else if let Some(parent_depr) = self.parent_depr.clone() { |
| self.index.depr_map.insert(hir_id, parent_depr); |
| visit_children(self); |
| } else { |
| visit_children(self); |
| } |
| } |
| } |
| } |
| |
| impl<'a, 'tcx> Visitor<'tcx> for Annotator<'a, 'tcx> { |
| /// Because stability levels are scoped lexically, we want to walk |
| /// nested items in the context of the outer item, so enable |
| /// deep-walking. |
| fn nested_visit_map<'this>(&'this mut self) -> NestedVisitorMap<'this, 'tcx> { |
| NestedVisitorMap::All(&self.tcx.hir()) |
| } |
| |
| fn visit_item(&mut self, i: &'tcx Item) { |
| let orig_in_trait_impl = self.in_trait_impl; |
| let mut kind = AnnotationKind::Required; |
| match i.node { |
| // Inherent impls and foreign modules serve only as containers for other items, |
| // they don't have their own stability. They still can be annotated as unstable |
| // and propagate this unstability to children, but this annotation is completely |
| // optional. They inherit stability from their parents when unannotated. |
| hir::ItemKind::Impl(.., None, _, _) | hir::ItemKind::ForeignMod(..) => { |
| self.in_trait_impl = false; |
| kind = AnnotationKind::Container; |
| } |
| hir::ItemKind::Impl(.., Some(_), _, _) => { |
| self.in_trait_impl = true; |
| } |
| hir::ItemKind::Struct(ref sd, _) => { |
| if let Some(ctor_hir_id) = sd.ctor_hir_id() { |
| self.annotate(ctor_hir_id, &i.attrs, i.span, AnnotationKind::Required, |_| {}) |
| } |
| } |
| _ => {} |
| } |
| |
| self.annotate(i.hir_id, &i.attrs, i.span, kind, |v| { |
| intravisit::walk_item(v, i) |
| }); |
| self.in_trait_impl = orig_in_trait_impl; |
| } |
| |
| fn visit_trait_item(&mut self, ti: &'tcx hir::TraitItem) { |
| self.annotate(ti.hir_id, &ti.attrs, ti.span, AnnotationKind::Required, |v| { |
| intravisit::walk_trait_item(v, ti); |
| }); |
| } |
| |
| fn visit_impl_item(&mut self, ii: &'tcx hir::ImplItem) { |
| let kind = if self.in_trait_impl { |
| AnnotationKind::Prohibited |
| } else { |
| AnnotationKind::Required |
| }; |
| self.annotate(ii.hir_id, &ii.attrs, ii.span, kind, |v| { |
| intravisit::walk_impl_item(v, ii); |
| }); |
| } |
| |
| fn visit_variant(&mut self, var: &'tcx Variant, g: &'tcx Generics, item_id: HirId) { |
| self.annotate(var.id, &var.attrs, var.span, AnnotationKind::Required, |
| |v| { |
| if let Some(ctor_hir_id) = var.data.ctor_hir_id() { |
| v.annotate(ctor_hir_id, &var.attrs, var.span, AnnotationKind::Required, |
| |_| {}); |
| } |
| |
| intravisit::walk_variant(v, var, g, item_id) |
| }) |
| } |
| |
| fn visit_struct_field(&mut self, s: &'tcx StructField) { |
| self.annotate(s.hir_id, &s.attrs, s.span, AnnotationKind::Required, |v| { |
| intravisit::walk_struct_field(v, s); |
| }); |
| } |
| |
| fn visit_foreign_item(&mut self, i: &'tcx hir::ForeignItem) { |
| self.annotate(i.hir_id, &i.attrs, i.span, AnnotationKind::Required, |v| { |
| intravisit::walk_foreign_item(v, i); |
| }); |
| } |
| |
| fn visit_macro_def(&mut self, md: &'tcx hir::MacroDef) { |
| self.annotate(md.hir_id, &md.attrs, md.span, AnnotationKind::Required, |_| {}); |
| } |
| } |
| |
| struct MissingStabilityAnnotations<'a, 'tcx> { |
| tcx: TyCtxt<'tcx>, |
| access_levels: &'a AccessLevels, |
| } |
| |
| impl<'a, 'tcx> MissingStabilityAnnotations<'a, 'tcx> { |
| fn check_missing_stability(&self, hir_id: HirId, span: Span, name: &str) { |
| let stab = self.tcx.stability().local_stability(hir_id); |
| let is_error = !self.tcx.sess.opts.test && |
| stab.is_none() && |
| self.access_levels.is_reachable(hir_id); |
| if is_error { |
| self.tcx.sess.span_err( |
| span, |
| &format!("{} has missing stability attribute", name), |
| ); |
| } |
| } |
| } |
| |
| impl<'a, 'tcx> Visitor<'tcx> for MissingStabilityAnnotations<'a, 'tcx> { |
| fn nested_visit_map<'this>(&'this mut self) -> NestedVisitorMap<'this, 'tcx> { |
| NestedVisitorMap::OnlyBodies(&self.tcx.hir()) |
| } |
| |
| fn visit_item(&mut self, i: &'tcx Item) { |
| match i.node { |
| // Inherent impls and foreign modules serve only as containers for other items, |
| // they don't have their own stability. They still can be annotated as unstable |
| // and propagate this unstability to children, but this annotation is completely |
| // optional. They inherit stability from their parents when unannotated. |
| hir::ItemKind::Impl(.., None, _, _) | hir::ItemKind::ForeignMod(..) => {} |
| |
| _ => self.check_missing_stability(i.hir_id, i.span, i.node.descriptive_variant()) |
| } |
| |
| intravisit::walk_item(self, i) |
| } |
| |
| fn visit_trait_item(&mut self, ti: &'tcx hir::TraitItem) { |
| self.check_missing_stability(ti.hir_id, ti.span, "item"); |
| intravisit::walk_trait_item(self, ti); |
| } |
| |
| fn visit_impl_item(&mut self, ii: &'tcx hir::ImplItem) { |
| let impl_def_id = self.tcx.hir().local_def_id( |
| self.tcx.hir().get_parent_item(ii.hir_id)); |
| if self.tcx.impl_trait_ref(impl_def_id).is_none() { |
| self.check_missing_stability(ii.hir_id, ii.span, "item"); |
| } |
| intravisit::walk_impl_item(self, ii); |
| } |
| |
| fn visit_variant(&mut self, var: &'tcx Variant, g: &'tcx Generics, item_id: HirId) { |
| self.check_missing_stability(var.id, var.span, "variant"); |
| intravisit::walk_variant(self, var, g, item_id); |
| } |
| |
| fn visit_struct_field(&mut self, s: &'tcx StructField) { |
| self.check_missing_stability(s.hir_id, s.span, "field"); |
| intravisit::walk_struct_field(self, s); |
| } |
| |
| fn visit_foreign_item(&mut self, i: &'tcx hir::ForeignItem) { |
| self.check_missing_stability(i.hir_id, i.span, i.node.descriptive_variant()); |
| intravisit::walk_foreign_item(self, i); |
| } |
| |
| fn visit_macro_def(&mut self, md: &'tcx hir::MacroDef) { |
| self.check_missing_stability(md.hir_id, md.span, "macro"); |
| } |
| } |
| |
| impl<'tcx> Index<'tcx> { |
| pub fn new(tcx: TyCtxt<'tcx>) -> Index<'tcx> { |
| let is_staged_api = |
| tcx.sess.opts.debugging_opts.force_unstable_if_unmarked || |
| tcx.features().staged_api; |
| let mut staged_api = FxHashMap::default(); |
| staged_api.insert(LOCAL_CRATE, is_staged_api); |
| let mut index = Index { |
| staged_api, |
| stab_map: Default::default(), |
| depr_map: Default::default(), |
| active_features: Default::default(), |
| }; |
| |
| let active_lib_features = &tcx.features().declared_lib_features; |
| let active_lang_features = &tcx.features().declared_lang_features; |
| |
| // Put the active features into a map for quick lookup. |
| index.active_features = |
| active_lib_features.iter().map(|&(ref s, ..)| s.clone()) |
| .chain(active_lang_features.iter().map(|&(ref s, ..)| s.clone())) |
| .collect(); |
| |
| { |
| let krate = tcx.hir().krate(); |
| let mut annotator = Annotator { |
| tcx, |
| index: &mut index, |
| parent_stab: None, |
| parent_depr: None, |
| in_trait_impl: false, |
| }; |
| |
| // If the `-Z force-unstable-if-unmarked` flag is passed then we provide |
| // a parent stability annotation which indicates that this is private |
| // with the `rustc_private` feature. This is intended for use when |
| // compiling librustc crates themselves so we can leverage crates.io |
| // while maintaining the invariant that all sysroot crates are unstable |
| // by default and are unable to be used. |
| if tcx.sess.opts.debugging_opts.force_unstable_if_unmarked { |
| let reason = "this crate is being loaded from the sysroot, an \ |
| unstable location; did you mean to load this crate \ |
| from crates.io via `Cargo.toml` instead?"; |
| let stability = tcx.intern_stability(Stability { |
| level: attr::StabilityLevel::Unstable { |
| reason: Some(Symbol::intern(reason)), |
| issue: 27812, |
| is_soft: false, |
| }, |
| feature: sym::rustc_private, |
| rustc_depr: None, |
| const_stability: None, |
| promotable: false, |
| allow_const_fn_ptr: false, |
| }); |
| annotator.parent_stab = Some(stability); |
| } |
| |
| annotator.annotate(hir::CRATE_HIR_ID, |
| &krate.attrs, |
| krate.span, |
| AnnotationKind::Required, |
| |v| intravisit::walk_crate(v, krate)); |
| } |
| return index; |
| } |
| |
| pub fn local_stability(&self, id: HirId) -> Option<&'tcx Stability> { |
| self.stab_map.get(&id).cloned() |
| } |
| |
| pub fn local_deprecation_entry(&self, id: HirId) -> Option<DeprecationEntry> { |
| self.depr_map.get(&id).cloned() |
| } |
| } |
| |
| /// Cross-references the feature names of unstable APIs with enabled |
| /// features and possibly prints errors. |
| fn check_mod_unstable_api_usage(tcx: TyCtxt<'_>, module_def_id: DefId) { |
| tcx.hir().visit_item_likes_in_module(module_def_id, &mut Checker { tcx }.as_deep_visitor()); |
| } |
| |
| pub fn provide(providers: &mut Providers<'_>) { |
| *providers = Providers { |
| check_mod_unstable_api_usage, |
| ..*providers |
| }; |
| } |
| |
| pub fn report_unstable( |
| sess: &Session, feature: Symbol, reason: Option<Symbol>, issue: u32, is_soft: bool, span: Span |
| ) { |
| let msg = match reason { |
| Some(r) => format!("use of unstable library feature '{}': {}", feature, r), |
| None => format!("use of unstable library feature '{}'", &feature) |
| }; |
| |
| let msp: MultiSpan = span.into(); |
| let cm = &sess.parse_sess.source_map(); |
| let span_key = msp.primary_span().and_then(|sp: Span| |
| if !sp.is_dummy() { |
| let file = cm.lookup_char_pos(sp.lo()).file; |
| if file.name.is_macros() { |
| None |
| } else { |
| Some(span) |
| } |
| } else { |
| None |
| } |
| ); |
| |
| let error_id = (DiagnosticMessageId::StabilityId(issue), span_key, msg.clone()); |
| let fresh = sess.one_time_diagnostics.borrow_mut().insert(error_id); |
| if fresh { |
| if is_soft { |
| sess.buffer_lint(lint::builtin::SOFT_UNSTABLE, CRATE_NODE_ID, span, &msg); |
| } else { |
| emit_feature_err( |
| &sess.parse_sess, feature, span, GateIssue::Library(Some(issue)), &msg |
| ); |
| } |
| } |
| } |
| |
| /// Checks whether an item marked with `deprecated(since="X")` is currently |
| /// deprecated (i.e., whether X is not greater than the current rustc version). |
| pub fn deprecation_in_effect(since: &str) -> bool { |
| fn parse_version(ver: &str) -> Vec<u32> { |
| // We ignore non-integer components of the version (e.g., "nightly"). |
| ver.split(|c| c == '.' || c == '-').flat_map(|s| s.parse()).collect() |
| } |
| |
| if let Some(rustc) = option_env!("CFG_RELEASE") { |
| let since: Vec<u32> = parse_version(since); |
| let rustc: Vec<u32> = parse_version(rustc); |
| // We simply treat invalid `since` attributes as relating to a previous |
| // Rust version, thus always displaying the warning. |
| if since.len() != 3 { |
| return true; |
| } |
| since <= rustc |
| } else { |
| // By default, a deprecation warning applies to |
| // the current version of the compiler. |
| true |
| } |
| } |
| |
| pub fn deprecation_suggestion( |
| diag: &mut DiagnosticBuilder<'_>, suggestion: Option<Symbol>, span: Span |
| ) { |
| if let Some(suggestion) = suggestion { |
| diag.span_suggestion( |
| span, |
| "replace the use of the deprecated item", |
| suggestion.to_string(), |
| Applicability::MachineApplicable, |
| ); |
| } |
| } |
| |
| fn deprecation_message_common(message: String, reason: Option<Symbol>) -> String { |
| match reason { |
| Some(reason) => format!("{}: {}", message, reason), |
| None => message, |
| } |
| } |
| |
| pub fn deprecation_message(depr: &Deprecation, path: &str) -> (String, &'static Lint) { |
| let message = format!("use of deprecated item '{}'", path); |
| (deprecation_message_common(message, depr.note), lint::builtin::DEPRECATED) |
| } |
| |
| pub fn rustc_deprecation_message(depr: &RustcDeprecation, path: &str) -> (String, &'static Lint) { |
| let (message, lint) = if deprecation_in_effect(&depr.since.as_str()) { |
| (format!("use of deprecated item '{}'", path), lint::builtin::DEPRECATED) |
| } else { |
| (format!("use of item '{}' that will be deprecated in future version {}", path, depr.since), |
| lint::builtin::DEPRECATED_IN_FUTURE) |
| }; |
| (deprecation_message_common(message, Some(depr.reason)), lint) |
| } |
| |
| pub fn early_report_deprecation( |
| sess: &Session, |
| message: &str, |
| suggestion: Option<Symbol>, |
| lint: &'static Lint, |
| span: Span, |
| ) { |
| if in_derive_expansion(span) { |
| return; |
| } |
| |
| let diag = BuiltinLintDiagnostics::DeprecatedMacro(suggestion, span); |
| sess.buffer_lint_with_diagnostic(lint, CRATE_NODE_ID, span, message, diag); |
| } |
| |
| fn late_report_deprecation( |
| tcx: TyCtxt<'_>, |
| message: &str, |
| suggestion: Option<Symbol>, |
| lint: &'static Lint, |
| span: Span, |
| def_id: DefId, |
| hir_id: HirId, |
| ) { |
| if in_derive_expansion(span) { |
| return; |
| } |
| |
| let mut diag = tcx.struct_span_lint_hir(lint, hir_id, span, message); |
| if let hir::Node::Expr(_) = tcx.hir().get(hir_id) { |
| deprecation_suggestion(&mut diag, suggestion, span); |
| } |
| diag.emit(); |
| if hir_id == hir::DUMMY_HIR_ID { |
| span_bug!(span, "emitted a {} lint with dummy HIR id: {:?}", lint.name, def_id); |
| } |
| } |
| |
| struct Checker<'tcx> { |
| tcx: TyCtxt<'tcx>, |
| } |
| |
| /// Result of `TyCtxt::eval_stability`. |
| pub enum EvalResult { |
| /// We can use the item because it is stable or we provided the |
| /// corresponding feature gate. |
| Allow, |
| /// We cannot use the item because it is unstable and we did not provide the |
| /// corresponding feature gate. |
| Deny { |
| feature: Symbol, |
| reason: Option<Symbol>, |
| issue: u32, |
| is_soft: bool, |
| }, |
| /// The item does not have the `#[stable]` or `#[unstable]` marker assigned. |
| Unmarked, |
| } |
| |
| impl<'tcx> TyCtxt<'tcx> { |
| // See issue #38412. |
| fn skip_stability_check_due_to_privacy(self, mut def_id: DefId) -> bool { |
| // Check if `def_id` is a trait method. |
| match self.def_kind(def_id) { |
| Some(DefKind::Method) | |
| Some(DefKind::AssocTy) | |
| Some(DefKind::AssocConst) => { |
| if let ty::TraitContainer(trait_def_id) = self.associated_item(def_id).container { |
| // Trait methods do not declare visibility (even |
| // for visibility info in cstore). Use containing |
| // trait instead, so methods of `pub` traits are |
| // themselves considered `pub`. |
| def_id = trait_def_id; |
| } |
| } |
| _ => {} |
| } |
| |
| let visibility = self.visibility(def_id); |
| |
| match visibility { |
| // Must check stability for `pub` items. |
| ty::Visibility::Public => false, |
| |
| // These are not visible outside crate; therefore |
| // stability markers are irrelevant, if even present. |
| ty::Visibility::Restricted(..) | |
| ty::Visibility::Invisible => true, |
| } |
| } |
| |
| /// Evaluates the stability of an item. |
| /// |
| /// Returns `EvalResult::Allow` if the item is stable, or unstable but the corresponding |
| /// `#![feature]` has been provided. Returns `EvalResult::Deny` which describes the offending |
| /// unstable feature otherwise. |
| /// |
| /// If `id` is `Some(_)`, this function will also check if the item at `def_id` has been |
| /// deprecated. If the item is indeed deprecated, we will emit a deprecation lint attached to |
| /// `id`. |
| pub fn eval_stability(self, def_id: DefId, id: Option<HirId>, span: Span) -> EvalResult { |
| // Deprecated attributes apply in-crate and cross-crate. |
| if let Some(id) = id { |
| if let Some(depr_entry) = self.lookup_deprecation_entry(def_id) { |
| let parent_def_id = self.hir().local_def_id( |
| self.hir().get_parent_item(id)); |
| let skip = self.lookup_deprecation_entry(parent_def_id) |
| .map_or(false, |parent_depr| parent_depr.same_origin(&depr_entry)); |
| |
| if !skip { |
| let (message, lint) = |
| deprecation_message(&depr_entry.attr, &self.def_path_str(def_id)); |
| late_report_deprecation(self, &message, None, lint, span, def_id, id); |
| } |
| }; |
| } |
| |
| let is_staged_api = self.lookup_stability(DefId { |
| index: CRATE_DEF_INDEX, |
| ..def_id |
| }).is_some(); |
| if !is_staged_api { |
| return EvalResult::Allow; |
| } |
| |
| let stability = self.lookup_stability(def_id); |
| debug!("stability: \ |
| inspecting def_id={:?} span={:?} of stability={:?}", def_id, span, stability); |
| |
| if let Some(id) = id { |
| if let Some(stability) = stability { |
| if let Some(depr) = &stability.rustc_depr { |
| let (message, lint) = |
| rustc_deprecation_message(depr, &self.def_path_str(def_id)); |
| late_report_deprecation( |
| self, &message, depr.suggestion, lint, span, def_id, id |
| ); |
| } |
| } |
| } |
| |
| // Only the cross-crate scenario matters when checking unstable APIs |
| let cross_crate = !def_id.is_local(); |
| if !cross_crate { |
| return EvalResult::Allow; |
| } |
| |
| // Issue #38412: private items lack stability markers. |
| if self.skip_stability_check_due_to_privacy(def_id) { |
| return EvalResult::Allow; |
| } |
| |
| match stability { |
| Some(&Stability { |
| level: attr::Unstable { reason, issue, is_soft }, feature, .. |
| }) => { |
| if span.allows_unstable(feature) { |
| debug!("stability: skipping span={:?} since it is internal", span); |
| return EvalResult::Allow; |
| } |
| if self.stability().active_features.contains(&feature) { |
| return EvalResult::Allow; |
| } |
| |
| // When we're compiling the compiler itself we may pull in |
| // crates from crates.io, but those crates may depend on other |
| // crates also pulled in from crates.io. We want to ideally be |
| // able to compile everything without requiring upstream |
| // modifications, so in the case that this looks like a |
| // `rustc_private` crate (e.g., a compiler crate) and we also have |
| // the `-Z force-unstable-if-unmarked` flag present (we're |
| // compiling a compiler crate), then let this missing feature |
| // annotation slide. |
| if feature == sym::rustc_private && issue == 27812 { |
| if self.sess.opts.debugging_opts.force_unstable_if_unmarked { |
| return EvalResult::Allow; |
| } |
| } |
| |
| EvalResult::Deny { feature, reason, issue, is_soft } |
| } |
| Some(_) => { |
| // Stable APIs are always ok to call and deprecated APIs are |
| // handled by the lint emitting logic above. |
| EvalResult::Allow |
| } |
| None => { |
| EvalResult::Unmarked |
| } |
| } |
| } |
| |
| /// Checks if an item is stable or error out. |
| /// |
| /// If the item defined by `def_id` is unstable and the corresponding `#![feature]` does not |
| /// exist, emits an error. |
| /// |
| /// Additionally, this function will also check if the item is deprecated. If so, and `id` is |
| /// not `None`, a deprecated lint attached to `id` will be emitted. |
| pub fn check_stability(self, def_id: DefId, id: Option<HirId>, span: Span) { |
| match self.eval_stability(def_id, id, span) { |
| EvalResult::Allow => {} |
| EvalResult::Deny { feature, reason, issue, is_soft } => |
| report_unstable(self.sess, feature, reason, issue, is_soft, span), |
| EvalResult::Unmarked => { |
| // The API could be uncallable for other reasons, for example when a private module |
| // was referenced. |
| self.sess.delay_span_bug(span, &format!("encountered unmarked API: {:?}", def_id)); |
| } |
| } |
| } |
| } |
| |
| impl Visitor<'tcx> for Checker<'tcx> { |
| /// Because stability levels are scoped lexically, we want to walk |
| /// nested items in the context of the outer item, so enable |
| /// deep-walking. |
| fn nested_visit_map<'this>(&'this mut self) -> NestedVisitorMap<'this, 'tcx> { |
| NestedVisitorMap::OnlyBodies(&self.tcx.hir()) |
| } |
| |
| fn visit_item(&mut self, item: &'tcx hir::Item) { |
| match item.node { |
| hir::ItemKind::ExternCrate(_) => { |
| // compiler-generated `extern crate` items have a dummy span. |
| if item.span.is_dummy() { return } |
| |
| let def_id = self.tcx.hir().local_def_id(item.hir_id); |
| let cnum = match self.tcx.extern_mod_stmt_cnum(def_id) { |
| Some(cnum) => cnum, |
| None => return, |
| }; |
| let def_id = DefId { krate: cnum, index: CRATE_DEF_INDEX }; |
| self.tcx.check_stability(def_id, Some(item.hir_id), item.span); |
| } |
| |
| // For implementations of traits, check the stability of each item |
| // individually as it's possible to have a stable trait with unstable |
| // items. |
| hir::ItemKind::Impl(.., Some(ref t), _, ref impl_item_refs) => { |
| if let Res::Def(DefKind::Trait, trait_did) = t.path.res { |
| for impl_item_ref in impl_item_refs { |
| let impl_item = self.tcx.hir().impl_item(impl_item_ref.id); |
| let trait_item_def_id = self.tcx.associated_items(trait_did) |
| .find(|item| item.ident.name == impl_item.ident.name) |
| .map(|item| item.def_id); |
| if let Some(def_id) = trait_item_def_id { |
| // Pass `None` to skip deprecation warnings. |
| self.tcx.check_stability(def_id, None, impl_item.span); |
| } |
| } |
| } |
| } |
| |
| // There's no good place to insert stability check for non-Copy unions, |
| // so semi-randomly perform it here in stability.rs |
| hir::ItemKind::Union(..) if !self.tcx.features().untagged_unions => { |
| let def_id = self.tcx.hir().local_def_id(item.hir_id); |
| let adt_def = self.tcx.adt_def(def_id); |
| let ty = self.tcx.type_of(def_id); |
| |
| if adt_def.has_dtor(self.tcx) { |
| emit_feature_err(&self.tcx.sess.parse_sess, |
| sym::untagged_unions, item.span, GateIssue::Language, |
| "unions with `Drop` implementations are unstable"); |
| } else { |
| let param_env = self.tcx.param_env(def_id); |
| if !param_env.can_type_implement_copy(self.tcx, ty).is_ok() { |
| emit_feature_err(&self.tcx.sess.parse_sess, |
| sym::untagged_unions, item.span, GateIssue::Language, |
| "unions with non-`Copy` fields are unstable"); |
| } |
| } |
| } |
| |
| _ => (/* pass */) |
| } |
| intravisit::walk_item(self, item); |
| } |
| |
| fn visit_path(&mut self, path: &'tcx hir::Path, id: hir::HirId) { |
| if let Some(def_id) = path.res.opt_def_id() { |
| self.tcx.check_stability(def_id, Some(id), path.span) |
| } |
| intravisit::walk_path(self, path) |
| } |
| } |
| |
| impl<'tcx> TyCtxt<'tcx> { |
| pub fn lookup_deprecation(self, id: DefId) -> Option<Deprecation> { |
| self.lookup_deprecation_entry(id).map(|depr| depr.attr) |
| } |
| } |
| |
| /// Given the list of enabled features that were not language features (i.e., that |
| /// were expected to be library features), and the list of features used from |
| /// libraries, identify activated features that don't exist and error about them. |
| pub fn check_unused_or_stable_features(tcx: TyCtxt<'_>) { |
| let access_levels = &tcx.privacy_access_levels(LOCAL_CRATE); |
| |
| if tcx.stability().staged_api[&LOCAL_CRATE] { |
| let krate = tcx.hir().krate(); |
| let mut missing = MissingStabilityAnnotations { |
| tcx, |
| access_levels, |
| }; |
| missing.check_missing_stability(hir::CRATE_HIR_ID, krate.span, "crate"); |
| intravisit::walk_crate(&mut missing, krate); |
| krate.visit_all_item_likes(&mut missing.as_deep_visitor()); |
| } |
| |
| let declared_lang_features = &tcx.features().declared_lang_features; |
| let mut lang_features = FxHashSet::default(); |
| for &(feature, span, since) in declared_lang_features { |
| if let Some(since) = since { |
| // Warn if the user has enabled an already-stable lang feature. |
| unnecessary_stable_feature_lint(tcx, span, feature, since); |
| } |
| if lang_features.contains(&feature) { |
| // Warn if the user enables a lang feature multiple times. |
| duplicate_feature_err(tcx.sess, span, feature); |
| } |
| lang_features.insert(feature); |
| } |
| |
| let declared_lib_features = &tcx.features().declared_lib_features; |
| let mut remaining_lib_features = FxHashMap::default(); |
| for (feature, span) in declared_lib_features { |
| if remaining_lib_features.contains_key(&feature) { |
| // Warn if the user enables a lib feature multiple times. |
| duplicate_feature_err(tcx.sess, *span, *feature); |
| } |
| remaining_lib_features.insert(feature, span.clone()); |
| } |
| // `stdbuild` has special handling for `libc`, so we need to |
| // recognise the feature when building std. |
| // Likewise, libtest is handled specially, so `test` isn't |
| // available as we'd like it to be. |
| // FIXME: only remove `libc` when `stdbuild` is active. |
| // FIXME: remove special casing for `test`. |
| remaining_lib_features.remove(&Symbol::intern("libc")); |
| remaining_lib_features.remove(&sym::test); |
| |
| let check_features = |
| |remaining_lib_features: &mut FxHashMap<_, _>, defined_features: &[_]| { |
| for &(feature, since) in defined_features { |
| if let Some(since) = since { |
| if let Some(span) = remaining_lib_features.get(&feature) { |
| // Warn if the user has enabled an already-stable lib feature. |
| unnecessary_stable_feature_lint(tcx, *span, feature, since); |
| } |
| } |
| remaining_lib_features.remove(&feature); |
| if remaining_lib_features.is_empty() { |
| break; |
| } |
| } |
| }; |
| |
| // We always collect the lib features declared in the current crate, even if there are |
| // no unknown features, because the collection also does feature attribute validation. |
| let local_defined_features = tcx.lib_features().to_vec(); |
| if !remaining_lib_features.is_empty() { |
| check_features(&mut remaining_lib_features, &local_defined_features); |
| |
| for &cnum in &*tcx.crates() { |
| if remaining_lib_features.is_empty() { |
| break; |
| } |
| check_features(&mut remaining_lib_features, tcx.defined_lib_features(cnum)); |
| } |
| } |
| |
| for (feature, span) in remaining_lib_features { |
| struct_span_err!(tcx.sess, span, E0635, "unknown feature `{}`", feature).emit(); |
| } |
| |
| // FIXME(#44232): the `used_features` table no longer exists, so we |
| // don't lint about unused features. We should reenable this one day! |
| } |
| |
| fn unnecessary_stable_feature_lint( |
| tcx: TyCtxt<'_>, |
| span: Span, |
| feature: Symbol, |
| since: Symbol, |
| ) { |
| tcx.lint_hir(lint::builtin::STABLE_FEATURES, |
| hir::CRATE_HIR_ID, |
| span, |
| &format!("the feature `{}` has been stable since {} and no longer requires \ |
| an attribute to enable", feature, since)); |
| } |
| |
| fn duplicate_feature_err(sess: &Session, span: Span, feature: Symbol) { |
| struct_span_err!(sess, span, E0636, "the feature `{}` has already been declared", feature) |
| .emit(); |
| } |
