| // Copyright 2012-2015 The Rust Project Developers. See the COPYRIGHT |
| // file at the top-level directory of this distribution and at |
| // http://rust-lang.org/COPYRIGHT. |
| // |
| // Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or |
| // http://www.apache.org/licenses/LICENSE-2.0> or the MIT license |
| // <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your |
| // option. This file may not be copied, modified, or distributed |
| // except according to those terms. |
| |
| //! Lints in the Rust compiler. |
| //! |
| //! This contains lints which can feasibly be implemented as their own |
| //! AST visitor. Also see `rustc::lint::builtin`, which contains the |
| //! definitions of lints that are emitted directly inside the main |
| //! compiler. |
| //! |
| //! To add a new lint to rustc, declare it here using `declare_lint!()`. |
| //! Then add code to emit the new lint in the appropriate circumstances. |
| //! You can do that in an existing `LintPass` if it makes sense, or in a |
| //! new `LintPass`, or using `Session::add_lint` elsewhere in the |
| //! compiler. Only do the latter if the check can't be written cleanly as a |
| //! `LintPass` (also, note that such lints will need to be defined in |
| //! `rustc::lint::builtin`, not here). |
| //! |
| //! If you define a new `LintPass`, you will also need to add it to the |
| //! `add_builtin!` or `add_builtin_with_new!` invocation in `lib.rs`. |
| //! Use the former for unit-like structs and the latter for structs with |
| //! a `pub fn new()`. |
| |
| use rustc::hir::def::Def; |
| use rustc::hir::def_id::DefId; |
| use rustc::cfg; |
| use rustc::ty::subst::Substs; |
| use rustc::ty::{self, Ty}; |
| use rustc::traits; |
| use rustc::hir::map as hir_map; |
| use util::nodemap::NodeSet; |
| use lint::{LateContext, LintContext, LintArray}; |
| use lint::{LintPass, LateLintPass, EarlyLintPass, EarlyContext}; |
| |
| use std::collections::HashSet; |
| use rustc::util::nodemap::FxHashSet; |
| |
| use syntax::tokenstream::{TokenTree, TokenStream}; |
| use syntax::ast; |
| use syntax::attr; |
| use syntax::source_map::Spanned; |
| use syntax::edition::Edition; |
| use syntax::feature_gate::{AttributeGate, AttributeType, Stability, deprecated_attributes}; |
| use syntax_pos::{BytePos, Span, SyntaxContext}; |
| use syntax::symbol::keywords; |
| use syntax::errors::{Applicability, DiagnosticBuilder}; |
| |
| use rustc::hir::{self, GenericParamKind, PatKind}; |
| use rustc::hir::intravisit::FnKind; |
| |
| use bad_style::{MethodLateContext, method_context}; |
| |
| // hardwired lints from librustc |
| pub use lint::builtin::*; |
| |
| declare_lint! { |
| WHILE_TRUE, |
| Warn, |
| "suggest using `loop { }` instead of `while true { }`" |
| } |
| |
| #[derive(Copy, Clone)] |
| pub struct WhileTrue; |
| |
| impl LintPass for WhileTrue { |
| fn get_lints(&self) -> LintArray { |
| lint_array!(WHILE_TRUE) |
| } |
| } |
| |
| impl<'a, 'tcx> LateLintPass<'a, 'tcx> for WhileTrue { |
| fn check_expr(&mut self, cx: &LateContext, e: &hir::Expr) { |
| if let hir::ExprKind::While(ref cond, ..) = e.node { |
| if let hir::ExprKind::Lit(ref lit) = cond.node { |
| if let ast::LitKind::Bool(true) = lit.node { |
| if lit.span.ctxt() == SyntaxContext::empty() { |
| let msg = "denote infinite loops with `loop { ... }`"; |
| let condition_span = cx.tcx.sess.source_map().def_span(e.span); |
| let mut err = cx.struct_span_lint(WHILE_TRUE, condition_span, msg); |
| err.span_suggestion_short_with_applicability( |
| condition_span, |
| "use `loop`", |
| "loop".to_owned(), |
| Applicability::MachineApplicable |
| ); |
| err.emit(); |
| } |
| } |
| } |
| } |
| } |
| } |
| |
| declare_lint! { |
| BOX_POINTERS, |
| Allow, |
| "use of owned (Box type) heap memory" |
| } |
| |
| #[derive(Copy, Clone)] |
| pub struct BoxPointers; |
| |
| impl BoxPointers { |
| fn check_heap_type<'a, 'tcx>(&self, cx: &LateContext, span: Span, ty: Ty) { |
| for leaf_ty in ty.walk() { |
| if leaf_ty.is_box() { |
| let m = format!("type uses owned (Box type) pointers: {}", ty); |
| cx.span_lint(BOX_POINTERS, span, &m); |
| } |
| } |
| } |
| } |
| |
| impl LintPass for BoxPointers { |
| fn get_lints(&self) -> LintArray { |
| lint_array!(BOX_POINTERS) |
| } |
| } |
| |
| impl<'a, 'tcx> LateLintPass<'a, 'tcx> for BoxPointers { |
| fn check_item(&mut self, cx: &LateContext, it: &hir::Item) { |
| match it.node { |
| hir::ItemKind::Fn(..) | |
| hir::ItemKind::Ty(..) | |
| hir::ItemKind::Enum(..) | |
| hir::ItemKind::Struct(..) | |
| hir::ItemKind::Union(..) => { |
| let def_id = cx.tcx.hir.local_def_id(it.id); |
| self.check_heap_type(cx, it.span, cx.tcx.type_of(def_id)) |
| } |
| _ => () |
| } |
| |
| // If it's a struct, we also have to check the fields' types |
| match it.node { |
| hir::ItemKind::Struct(ref struct_def, _) | |
| hir::ItemKind::Union(ref struct_def, _) => { |
| for struct_field in struct_def.fields() { |
| let def_id = cx.tcx.hir.local_def_id(struct_field.id); |
| self.check_heap_type(cx, struct_field.span, |
| cx.tcx.type_of(def_id)); |
| } |
| } |
| _ => (), |
| } |
| } |
| |
| fn check_expr(&mut self, cx: &LateContext, e: &hir::Expr) { |
| let ty = cx.tables.node_id_to_type(e.hir_id); |
| self.check_heap_type(cx, e.span, ty); |
| } |
| } |
| |
| declare_lint! { |
| NON_SHORTHAND_FIELD_PATTERNS, |
| Warn, |
| "using `Struct { x: x }` instead of `Struct { x }` in a pattern" |
| } |
| |
| #[derive(Copy, Clone)] |
| pub struct NonShorthandFieldPatterns; |
| |
| impl LintPass for NonShorthandFieldPatterns { |
| fn get_lints(&self) -> LintArray { |
| lint_array!(NON_SHORTHAND_FIELD_PATTERNS) |
| } |
| } |
| |
| impl<'a, 'tcx> LateLintPass<'a, 'tcx> for NonShorthandFieldPatterns { |
| fn check_pat(&mut self, cx: &LateContext, pat: &hir::Pat) { |
| if let PatKind::Struct(ref qpath, ref field_pats, _) = pat.node { |
| let variant = cx.tables.pat_ty(pat).ty_adt_def() |
| .expect("struct pattern type is not an ADT") |
| .variant_of_def(cx.tables.qpath_def(qpath, pat.hir_id)); |
| for fieldpat in field_pats { |
| if fieldpat.node.is_shorthand { |
| continue; |
| } |
| if fieldpat.span.ctxt().outer().expn_info().is_some() { |
| // Don't lint if this is a macro expansion: macro authors |
| // shouldn't have to worry about this kind of style issue |
| // (Issue #49588) |
| continue; |
| } |
| if let PatKind::Binding(_, _, ident, None) = fieldpat.node.pat.node { |
| if cx.tcx.find_field_index(ident, &variant) == |
| Some(cx.tcx.field_index(fieldpat.node.id, cx.tables)) { |
| let mut err = cx.struct_span_lint(NON_SHORTHAND_FIELD_PATTERNS, |
| fieldpat.span, |
| &format!("the `{}:` in this pattern is redundant", ident)); |
| let subspan = cx.tcx.sess.source_map().span_through_char(fieldpat.span, |
| ':'); |
| err.span_suggestion_short_with_applicability( |
| subspan, |
| "remove this", |
| ident.to_string(), |
| Applicability::MachineApplicable |
| ); |
| err.emit(); |
| } |
| } |
| } |
| } |
| } |
| } |
| |
| declare_lint! { |
| UNSAFE_CODE, |
| Allow, |
| "usage of `unsafe` code" |
| } |
| |
| #[derive(Copy, Clone)] |
| pub struct UnsafeCode; |
| |
| impl LintPass for UnsafeCode { |
| fn get_lints(&self) -> LintArray { |
| lint_array!(UNSAFE_CODE) |
| } |
| } |
| |
| impl UnsafeCode { |
| fn report_unsafe(&self, cx: &LateContext, span: Span, desc: &'static str) { |
| // This comes from a macro that has #[allow_internal_unsafe]. |
| if span.allows_unsafe() { |
| return; |
| } |
| |
| cx.span_lint(UNSAFE_CODE, span, desc); |
| } |
| } |
| |
| impl<'a, 'tcx> LateLintPass<'a, 'tcx> for UnsafeCode { |
| fn check_expr(&mut self, cx: &LateContext, e: &hir::Expr) { |
| if let hir::ExprKind::Block(ref blk, _) = e.node { |
| // Don't warn about generated blocks, that'll just pollute the output. |
| if blk.rules == hir::UnsafeBlock(hir::UserProvided) { |
| self.report_unsafe(cx, blk.span, "usage of an `unsafe` block"); |
| } |
| } |
| } |
| |
| fn check_item(&mut self, cx: &LateContext, it: &hir::Item) { |
| match it.node { |
| hir::ItemKind::Trait(_, hir::Unsafety::Unsafe, ..) => { |
| self.report_unsafe(cx, it.span, "declaration of an `unsafe` trait") |
| } |
| |
| hir::ItemKind::Impl(hir::Unsafety::Unsafe, ..) => { |
| self.report_unsafe(cx, it.span, "implementation of an `unsafe` trait") |
| } |
| |
| _ => return, |
| } |
| } |
| |
| fn check_fn(&mut self, |
| cx: &LateContext, |
| fk: FnKind<'tcx>, |
| _: &hir::FnDecl, |
| _: &hir::Body, |
| span: Span, |
| _: ast::NodeId) { |
| match fk { |
| FnKind::ItemFn(_, _, hir::FnHeader { unsafety: hir::Unsafety::Unsafe, .. }, ..) => { |
| self.report_unsafe(cx, span, "declaration of an `unsafe` function") |
| } |
| |
| FnKind::Method(_, sig, ..) => { |
| if sig.header.unsafety == hir::Unsafety::Unsafe { |
| self.report_unsafe(cx, span, "implementation of an `unsafe` method") |
| } |
| } |
| |
| _ => (), |
| } |
| } |
| |
| fn check_trait_item(&mut self, cx: &LateContext, item: &hir::TraitItem) { |
| if let hir::TraitItemKind::Method(ref sig, hir::TraitMethod::Required(_)) = item.node { |
| if sig.header.unsafety == hir::Unsafety::Unsafe { |
| self.report_unsafe(cx, item.span, "declaration of an `unsafe` method") |
| } |
| } |
| } |
| } |
| |
| declare_lint! { |
| pub MISSING_DOCS, |
| Allow, |
| "detects missing documentation for public members" |
| } |
| |
| pub struct MissingDoc { |
| /// Stack of whether #[doc(hidden)] is set |
| /// at each level which has lint attributes. |
| doc_hidden_stack: Vec<bool>, |
| |
| /// Private traits or trait items that leaked through. Don't check their methods. |
| private_traits: HashSet<ast::NodeId>, |
| } |
| |
| impl MissingDoc { |
| pub fn new() -> MissingDoc { |
| MissingDoc { |
| doc_hidden_stack: vec![false], |
| private_traits: HashSet::new(), |
| } |
| } |
| |
| fn doc_hidden(&self) -> bool { |
| *self.doc_hidden_stack.last().expect("empty doc_hidden_stack") |
| } |
| |
| fn check_missing_docs_attrs(&self, |
| cx: &LateContext, |
| id: Option<ast::NodeId>, |
| attrs: &[ast::Attribute], |
| sp: Span, |
| desc: &'static str) { |
| // If we're building a test harness, then warning about |
| // documentation is probably not really relevant right now. |
| if cx.sess().opts.test { |
| return; |
| } |
| |
| // `#[doc(hidden)]` disables missing_docs check. |
| if self.doc_hidden() { |
| return; |
| } |
| |
| // Only check publicly-visible items, using the result from the privacy pass. |
| // It's an option so the crate root can also use this function (it doesn't |
| // have a NodeId). |
| if let Some(id) = id { |
| if !cx.access_levels.is_exported(id) { |
| return; |
| } |
| } |
| |
| fn has_doc(attr: &ast::Attribute) -> bool { |
| if !attr.check_name("doc") { |
| return false; |
| } |
| |
| if attr.is_value_str() { |
| return true; |
| } |
| |
| if let Some(list) = attr.meta_item_list() { |
| for meta in list { |
| if meta.check_name("include") { |
| return true; |
| } |
| } |
| } |
| |
| false |
| } |
| |
| let has_doc = attrs.iter().any(|a| has_doc(a)); |
| if !has_doc { |
| cx.span_lint(MISSING_DOCS, |
| cx.tcx.sess.source_map().def_span(sp), |
| &format!("missing documentation for {}", desc)); |
| } |
| } |
| } |
| |
| impl LintPass for MissingDoc { |
| fn get_lints(&self) -> LintArray { |
| lint_array!(MISSING_DOCS) |
| } |
| } |
| |
| impl<'a, 'tcx> LateLintPass<'a, 'tcx> for MissingDoc { |
| fn enter_lint_attrs(&mut self, _: &LateContext, attrs: &[ast::Attribute]) { |
| let doc_hidden = self.doc_hidden() || |
| attrs.iter().any(|attr| { |
| attr.check_name("doc") && |
| match attr.meta_item_list() { |
| None => false, |
| Some(l) => attr::list_contains_name(&l, "hidden"), |
| } |
| }); |
| self.doc_hidden_stack.push(doc_hidden); |
| } |
| |
| fn exit_lint_attrs(&mut self, _: &LateContext, _attrs: &[ast::Attribute]) { |
| self.doc_hidden_stack.pop().expect("empty doc_hidden_stack"); |
| } |
| |
| fn check_crate(&mut self, cx: &LateContext, krate: &hir::Crate) { |
| self.check_missing_docs_attrs(cx, None, &krate.attrs, krate.span, "crate"); |
| } |
| |
| fn check_item(&mut self, cx: &LateContext, it: &hir::Item) { |
| let desc = match it.node { |
| hir::ItemKind::Fn(..) => "a function", |
| hir::ItemKind::Mod(..) => "a module", |
| hir::ItemKind::Enum(..) => "an enum", |
| hir::ItemKind::Struct(..) => "a struct", |
| hir::ItemKind::Union(..) => "a union", |
| hir::ItemKind::Trait(.., ref trait_item_refs) => { |
| // Issue #11592, traits are always considered exported, even when private. |
| if let hir::VisibilityKind::Inherited = it.vis.node { |
| self.private_traits.insert(it.id); |
| for trait_item_ref in trait_item_refs { |
| self.private_traits.insert(trait_item_ref.id.node_id); |
| } |
| return; |
| } |
| "a trait" |
| } |
| hir::ItemKind::Ty(..) => "a type alias", |
| hir::ItemKind::Impl(.., Some(ref trait_ref), _, ref impl_item_refs) => { |
| // If the trait is private, add the impl items to private_traits so they don't get |
| // reported for missing docs. |
| let real_trait = trait_ref.path.def.def_id(); |
| if let Some(node_id) = cx.tcx.hir.as_local_node_id(real_trait) { |
| match cx.tcx.hir.find(node_id) { |
| Some(hir_map::NodeItem(item)) => { |
| if let hir::VisibilityKind::Inherited = item.vis.node { |
| for impl_item_ref in impl_item_refs { |
| self.private_traits.insert(impl_item_ref.id.node_id); |
| } |
| } |
| } |
| _ => {} |
| } |
| } |
| return; |
| } |
| hir::ItemKind::Const(..) => "a constant", |
| hir::ItemKind::Static(..) => "a static", |
| _ => return, |
| }; |
| |
| self.check_missing_docs_attrs(cx, Some(it.id), &it.attrs, it.span, desc); |
| } |
| |
| fn check_trait_item(&mut self, cx: &LateContext, trait_item: &hir::TraitItem) { |
| if self.private_traits.contains(&trait_item.id) { |
| return; |
| } |
| |
| let desc = match trait_item.node { |
| hir::TraitItemKind::Const(..) => "an associated constant", |
| hir::TraitItemKind::Method(..) => "a trait method", |
| hir::TraitItemKind::Type(..) => "an associated type", |
| }; |
| |
| self.check_missing_docs_attrs(cx, |
| Some(trait_item.id), |
| &trait_item.attrs, |
| trait_item.span, |
| desc); |
| } |
| |
| fn check_impl_item(&mut self, cx: &LateContext, impl_item: &hir::ImplItem) { |
| // If the method is an impl for a trait, don't doc. |
| if method_context(cx, impl_item.id) == MethodLateContext::TraitImpl { |
| return; |
| } |
| |
| let desc = match impl_item.node { |
| hir::ImplItemKind::Const(..) => "an associated constant", |
| hir::ImplItemKind::Method(..) => "a method", |
| hir::ImplItemKind::Type(_) => "an associated type", |
| hir::ImplItemKind::Existential(_) => "an associated existential type", |
| }; |
| self.check_missing_docs_attrs(cx, |
| Some(impl_item.id), |
| &impl_item.attrs, |
| impl_item.span, |
| desc); |
| } |
| |
| fn check_struct_field(&mut self, cx: &LateContext, sf: &hir::StructField) { |
| if !sf.is_positional() { |
| self.check_missing_docs_attrs(cx, |
| Some(sf.id), |
| &sf.attrs, |
| sf.span, |
| "a struct field") |
| } |
| } |
| |
| fn check_variant(&mut self, cx: &LateContext, v: &hir::Variant, _: &hir::Generics) { |
| self.check_missing_docs_attrs(cx, |
| Some(v.node.data.id()), |
| &v.node.attrs, |
| v.span, |
| "a variant"); |
| } |
| } |
| |
| declare_lint! { |
| pub MISSING_COPY_IMPLEMENTATIONS, |
| Allow, |
| "detects potentially-forgotten implementations of `Copy`" |
| } |
| |
| #[derive(Copy, Clone)] |
| pub struct MissingCopyImplementations; |
| |
| impl LintPass for MissingCopyImplementations { |
| fn get_lints(&self) -> LintArray { |
| lint_array!(MISSING_COPY_IMPLEMENTATIONS) |
| } |
| } |
| |
| impl<'a, 'tcx> LateLintPass<'a, 'tcx> for MissingCopyImplementations { |
| fn check_item(&mut self, cx: &LateContext, item: &hir::Item) { |
| if !cx.access_levels.is_reachable(item.id) { |
| return; |
| } |
| let (def, ty) = match item.node { |
| hir::ItemKind::Struct(_, ref ast_generics) => { |
| if !ast_generics.params.is_empty() { |
| return; |
| } |
| let def = cx.tcx.adt_def(cx.tcx.hir.local_def_id(item.id)); |
| (def, cx.tcx.mk_adt(def, cx.tcx.intern_substs(&[]))) |
| } |
| hir::ItemKind::Union(_, ref ast_generics) => { |
| if !ast_generics.params.is_empty() { |
| return; |
| } |
| let def = cx.tcx.adt_def(cx.tcx.hir.local_def_id(item.id)); |
| (def, cx.tcx.mk_adt(def, cx.tcx.intern_substs(&[]))) |
| } |
| hir::ItemKind::Enum(_, ref ast_generics) => { |
| if !ast_generics.params.is_empty() { |
| return; |
| } |
| let def = cx.tcx.adt_def(cx.tcx.hir.local_def_id(item.id)); |
| (def, cx.tcx.mk_adt(def, cx.tcx.intern_substs(&[]))) |
| } |
| _ => return, |
| }; |
| if def.has_dtor(cx.tcx) { |
| return; |
| } |
| let param_env = ty::ParamEnv::empty(); |
| if !ty.moves_by_default(cx.tcx, param_env, item.span) { |
| return; |
| } |
| if param_env.can_type_implement_copy(cx.tcx, ty).is_ok() { |
| cx.span_lint(MISSING_COPY_IMPLEMENTATIONS, |
| item.span, |
| "type could implement `Copy`; consider adding `impl \ |
| Copy`") |
| } |
| } |
| } |
| |
| declare_lint! { |
| MISSING_DEBUG_IMPLEMENTATIONS, |
| Allow, |
| "detects missing implementations of fmt::Debug" |
| } |
| |
| pub struct MissingDebugImplementations { |
| impling_types: Option<NodeSet>, |
| } |
| |
| impl MissingDebugImplementations { |
| pub fn new() -> MissingDebugImplementations { |
| MissingDebugImplementations { impling_types: None } |
| } |
| } |
| |
| impl LintPass for MissingDebugImplementations { |
| fn get_lints(&self) -> LintArray { |
| lint_array!(MISSING_DEBUG_IMPLEMENTATIONS) |
| } |
| } |
| |
| impl<'a, 'tcx> LateLintPass<'a, 'tcx> for MissingDebugImplementations { |
| fn check_item(&mut self, cx: &LateContext, item: &hir::Item) { |
| if !cx.access_levels.is_reachable(item.id) { |
| return; |
| } |
| |
| match item.node { |
| hir::ItemKind::Struct(..) | |
| hir::ItemKind::Union(..) | |
| hir::ItemKind::Enum(..) => {} |
| _ => return, |
| } |
| |
| let debug = match cx.tcx.lang_items().debug_trait() { |
| Some(debug) => debug, |
| None => return, |
| }; |
| |
| if self.impling_types.is_none() { |
| let mut impls = NodeSet(); |
| cx.tcx.for_each_impl(debug, |d| { |
| if let Some(ty_def) = cx.tcx.type_of(d).ty_adt_def() { |
| if let Some(node_id) = cx.tcx.hir.as_local_node_id(ty_def.did) { |
| impls.insert(node_id); |
| } |
| } |
| }); |
| |
| self.impling_types = Some(impls); |
| debug!("{:?}", self.impling_types); |
| } |
| |
| if !self.impling_types.as_ref().unwrap().contains(&item.id) { |
| cx.span_lint(MISSING_DEBUG_IMPLEMENTATIONS, |
| item.span, |
| "type does not implement `fmt::Debug`; consider adding #[derive(Debug)] \ |
| or a manual implementation") |
| } |
| } |
| } |
| |
| declare_lint! { |
| pub ANONYMOUS_PARAMETERS, |
| Allow, |
| "detects anonymous parameters", |
| Edition::Edition2018 => Warn |
| } |
| |
| /// Checks for use of anonymous parameters (RFC 1685) |
| #[derive(Clone)] |
| pub struct AnonymousParameters; |
| |
| impl LintPass for AnonymousParameters { |
| fn get_lints(&self) -> LintArray { |
| lint_array!(ANONYMOUS_PARAMETERS) |
| } |
| } |
| |
| impl EarlyLintPass for AnonymousParameters { |
| fn check_trait_item(&mut self, cx: &EarlyContext, it: &ast::TraitItem) { |
| match it.node { |
| ast::TraitItemKind::Method(ref sig, _) => { |
| for arg in sig.decl.inputs.iter() { |
| match arg.pat.node { |
| ast::PatKind::Ident(_, ident, None) => { |
| if ident.name == keywords::Invalid.name() { |
| let ty_snip = cx |
| .sess |
| .source_map() |
| .span_to_snippet(arg.ty.span); |
| |
| let (ty_snip, appl) = if let Ok(snip) = ty_snip { |
| (snip, Applicability::MachineApplicable) |
| } else { |
| ("<type>".to_owned(), Applicability::HasPlaceholders) |
| }; |
| |
| cx.struct_span_lint( |
| ANONYMOUS_PARAMETERS, |
| arg.pat.span, |
| "anonymous parameters are deprecated and will be \ |
| removed in the next edition." |
| ).span_suggestion_with_applicability( |
| arg.pat.span, |
| "Try naming the parameter or explicitly \ |
| ignoring it", |
| format!("_: {}", ty_snip), |
| appl |
| ).emit(); |
| } |
| } |
| _ => (), |
| } |
| } |
| }, |
| _ => (), |
| } |
| } |
| } |
| |
| /// Checks for incorrect use use of `repr` attributes. |
| #[derive(Clone)] |
| pub struct BadRepr; |
| |
| impl LintPass for BadRepr { |
| fn get_lints(&self) -> LintArray { |
| lint_array!() |
| } |
| } |
| |
| impl EarlyLintPass for BadRepr { |
| fn check_attribute(&mut self, cx: &EarlyContext, attr: &ast::Attribute) { |
| if attr.name() == "repr" { |
| let list = attr.meta_item_list(); |
| |
| let repr_str = |lit: &str| { format!("#[repr({})]", lit) }; |
| |
| // Emit warnings with `repr` either has a literal assignment (`#[repr = "C"]`) or |
| // no hints (``#[repr]`) |
| let has_hints = list.as_ref().map(|ref list| !list.is_empty()).unwrap_or(false); |
| if !has_hints { |
| let mut suggested = false; |
| let mut warn = if let Some(ref lit) = attr.value_str() { |
| // avoid warning about empty `repr` on `#[repr = "foo"]` |
| let mut warn = cx.struct_span_lint( |
| BAD_REPR, |
| attr.span, |
| "`repr` attribute isn't configurable with a literal", |
| ); |
| match lit.to_string().as_ref() { |
| | "C" | "packed" | "rust" | "transparent" |
| | "u8" | "u16" | "u32" | "u64" | "u128" | "usize" |
| | "i8" | "i16" | "i32" | "i64" | "i128" | "isize" => { |
| // if the literal could have been a valid `repr` arg, |
| // suggest the correct syntax |
| warn.span_suggestion_with_applicability( |
| attr.span, |
| "give `repr` a hint", |
| repr_str(&lit.as_str()), |
| Applicability::MachineApplicable |
| ); |
| suggested = true; |
| } |
| _ => { // the literal wasn't a valid `repr` arg |
| warn.span_label(attr.span, "needs a hint"); |
| } |
| }; |
| warn |
| } else { |
| let mut warn = cx.struct_span_lint( |
| BAD_REPR, |
| attr.span, |
| "`repr` attribute must have a hint", |
| ); |
| warn.span_label(attr.span, "needs a hint"); |
| warn |
| }; |
| if !suggested { |
| warn.help(&format!( |
| "valid hints include `{}`, `{}`, `{}` and `{}`", |
| repr_str("C"), |
| repr_str("packed"), |
| repr_str("rust"), |
| repr_str("transparent"), |
| )); |
| warn.note("for more information, visit \ |
| <https://doc.rust-lang.org/reference/type-layout.html>"); |
| } |
| warn.emit(); |
| } |
| } |
| } |
| } |
| |
| /// Checks for use of attributes which have been deprecated. |
| #[derive(Clone)] |
| pub struct DeprecatedAttr { |
| // This is not free to compute, so we want to keep it around, rather than |
| // compute it for every attribute. |
| depr_attrs: Vec<&'static (&'static str, AttributeType, AttributeGate)>, |
| } |
| |
| impl DeprecatedAttr { |
| pub fn new() -> DeprecatedAttr { |
| DeprecatedAttr { |
| depr_attrs: deprecated_attributes(), |
| } |
| } |
| } |
| |
| impl LintPass for DeprecatedAttr { |
| fn get_lints(&self) -> LintArray { |
| lint_array!() |
| } |
| } |
| |
| impl EarlyLintPass for DeprecatedAttr { |
| fn check_attribute(&mut self, cx: &EarlyContext, attr: &ast::Attribute) { |
| for &&(n, _, ref g) in &self.depr_attrs { |
| if attr.name() == n { |
| if let &AttributeGate::Gated(Stability::Deprecated(link), |
| ref name, |
| ref reason, |
| _) = g { |
| let msg = format!("use of deprecated attribute `{}`: {}. See {}", |
| name, reason, link); |
| let mut err = cx.struct_span_lint(DEPRECATED, attr.span, &msg); |
| err.span_suggestion_short_with_applicability( |
| attr.span, |
| "remove this attribute", |
| "".to_owned(), |
| Applicability::MachineApplicable |
| ); |
| err.emit(); |
| } |
| return; |
| } |
| } |
| } |
| } |
| |
| declare_lint! { |
| pub UNUSED_DOC_COMMENTS, |
| Warn, |
| "detects doc comments that aren't used by rustdoc" |
| } |
| |
| #[derive(Copy, Clone)] |
| pub struct UnusedDocComment; |
| |
| impl LintPass for UnusedDocComment { |
| fn get_lints(&self) -> LintArray { |
| lint_array![UNUSED_DOC_COMMENTS] |
| } |
| } |
| |
| impl UnusedDocComment { |
| fn warn_if_doc<'a, 'tcx, |
| I: Iterator<Item=&'a ast::Attribute>, |
| C: LintContext<'tcx>>(&self, mut attrs: I, cx: &C) { |
| if let Some(attr) = attrs.find(|a| a.is_value_str() && a.check_name("doc")) { |
| cx.struct_span_lint(UNUSED_DOC_COMMENTS, attr.span, "doc comment not used by rustdoc") |
| .emit(); |
| } |
| } |
| } |
| |
| impl EarlyLintPass for UnusedDocComment { |
| fn check_local(&mut self, cx: &EarlyContext, decl: &ast::Local) { |
| self.warn_if_doc(decl.attrs.iter(), cx); |
| } |
| |
| fn check_arm(&mut self, cx: &EarlyContext, arm: &ast::Arm) { |
| self.warn_if_doc(arm.attrs.iter(), cx); |
| } |
| |
| fn check_expr(&mut self, cx: &EarlyContext, expr: &ast::Expr) { |
| self.warn_if_doc(expr.attrs.iter(), cx); |
| } |
| } |
| |
| declare_lint! { |
| pub UNCONDITIONAL_RECURSION, |
| Warn, |
| "functions that cannot return without calling themselves" |
| } |
| |
| #[derive(Copy, Clone)] |
| pub struct UnconditionalRecursion; |
| |
| |
| impl LintPass for UnconditionalRecursion { |
| fn get_lints(&self) -> LintArray { |
| lint_array![UNCONDITIONAL_RECURSION] |
| } |
| } |
| |
| impl<'a, 'tcx> LateLintPass<'a, 'tcx> for UnconditionalRecursion { |
| fn check_fn(&mut self, |
| cx: &LateContext, |
| fn_kind: FnKind, |
| _: &hir::FnDecl, |
| body: &hir::Body, |
| sp: Span, |
| id: ast::NodeId) { |
| let method = match fn_kind { |
| FnKind::ItemFn(..) => None, |
| FnKind::Method(..) => { |
| Some(cx.tcx.associated_item(cx.tcx.hir.local_def_id(id))) |
| } |
| // closures can't recur, so they don't matter. |
| FnKind::Closure(_) => return, |
| }; |
| |
| // Walk through this function (say `f`) looking to see if |
| // every possible path references itself, i.e. the function is |
| // called recursively unconditionally. This is done by trying |
| // to find a path from the entry node to the exit node that |
| // *doesn't* call `f` by traversing from the entry while |
| // pretending that calls of `f` are sinks (i.e. ignoring any |
| // exit edges from them). |
| // |
| // NB. this has an edge case with non-returning statements, |
| // like `loop {}` or `panic!()`: control flow never reaches |
| // the exit node through these, so one can have a function |
| // that never actually calls itselfs but is still picked up by |
| // this lint: |
| // |
| // fn f(cond: bool) { |
| // if !cond { panic!() } // could come from `assert!(cond)` |
| // f(false) |
| // } |
| // |
| // In general, functions of that form may be able to call |
| // itself a finite number of times and then diverge. The lint |
| // considers this to be an error for two reasons, (a) it is |
| // easier to implement, and (b) it seems rare to actually want |
| // to have behaviour like the above, rather than |
| // e.g. accidentally recurring after an assert. |
| |
| let cfg = cfg::CFG::new(cx.tcx, &body); |
| |
| let mut work_queue = vec![cfg.entry]; |
| let mut reached_exit_without_self_call = false; |
| let mut self_call_spans = vec![]; |
| let mut visited = HashSet::new(); |
| |
| while let Some(idx) = work_queue.pop() { |
| if idx == cfg.exit { |
| // found a path! |
| reached_exit_without_self_call = true; |
| break; |
| } |
| |
| let cfg_id = idx.node_id(); |
| if visited.contains(&cfg_id) { |
| // already done |
| continue; |
| } |
| visited.insert(cfg_id); |
| |
| // is this a recursive call? |
| let local_id = cfg.graph.node_data(idx).id(); |
| if local_id != hir::DUMMY_ITEM_LOCAL_ID { |
| let node_id = cx.tcx.hir.hir_to_node_id(hir::HirId { |
| owner: body.value.hir_id.owner, |
| local_id |
| }); |
| let self_recursive = match method { |
| Some(ref method) => expr_refers_to_this_method(cx, method, node_id), |
| None => expr_refers_to_this_fn(cx, id, node_id), |
| }; |
| if self_recursive { |
| self_call_spans.push(cx.tcx.hir.span(node_id)); |
| // this is a self call, so we shouldn't explore past |
| // this node in the CFG. |
| continue; |
| } |
| } |
| |
| // add the successors of this node to explore the graph further. |
| for (_, edge) in cfg.graph.outgoing_edges(idx) { |
| let target_idx = edge.target(); |
| let target_cfg_id = target_idx.node_id(); |
| if !visited.contains(&target_cfg_id) { |
| work_queue.push(target_idx) |
| } |
| } |
| } |
| |
| // Check the number of self calls because a function that |
| // doesn't return (e.g. calls a `-> !` function or `loop { /* |
| // no break */ }`) shouldn't be linted unless it actually |
| // recurs. |
| if !reached_exit_without_self_call && !self_call_spans.is_empty() { |
| let sp = cx.tcx.sess.source_map().def_span(sp); |
| let mut db = cx.struct_span_lint(UNCONDITIONAL_RECURSION, |
| sp, |
| "function cannot return without recurring"); |
| db.span_label(sp, "cannot return without recurring"); |
| // offer some help to the programmer. |
| for call in &self_call_spans { |
| db.span_label(*call, "recursive call site"); |
| } |
| db.help("a `loop` may express intention better if this is on purpose"); |
| db.emit(); |
| } |
| |
| // all done |
| return; |
| |
| // Functions for identifying if the given Expr NodeId `id` |
| // represents a call to the function `fn_id`/method `method`. |
| |
| fn expr_refers_to_this_fn(cx: &LateContext, fn_id: ast::NodeId, id: ast::NodeId) -> bool { |
| match cx.tcx.hir.get(id) { |
| hir_map::NodeExpr(&hir::Expr { node: hir::ExprKind::Call(ref callee, _), .. }) => { |
| let def = if let hir::ExprKind::Path(ref qpath) = callee.node { |
| cx.tables.qpath_def(qpath, callee.hir_id) |
| } else { |
| return false; |
| }; |
| match def { |
| Def::Local(..) | Def::Upvar(..) => false, |
| _ => def.def_id() == cx.tcx.hir.local_def_id(fn_id) |
| } |
| } |
| _ => false, |
| } |
| } |
| |
| // Check if the expression `id` performs a call to `method`. |
| fn expr_refers_to_this_method(cx: &LateContext, |
| method: &ty::AssociatedItem, |
| id: ast::NodeId) |
| -> bool { |
| use rustc::ty::adjustment::*; |
| |
| // Ignore non-expressions. |
| let expr = if let hir_map::NodeExpr(e) = cx.tcx.hir.get(id) { |
| e |
| } else { |
| return false; |
| }; |
| |
| // Check for overloaded autoderef method calls. |
| let mut source = cx.tables.expr_ty(expr); |
| for adjustment in cx.tables.expr_adjustments(expr) { |
| if let Adjust::Deref(Some(deref)) = adjustment.kind { |
| let (def_id, substs) = deref.method_call(cx.tcx, source); |
| if method_call_refers_to_method(cx, method, def_id, substs, id) { |
| return true; |
| } |
| } |
| source = adjustment.target; |
| } |
| |
| // Check for method calls and overloaded operators. |
| if cx.tables.is_method_call(expr) { |
| let hir_id = cx.tcx.hir.definitions().node_to_hir_id(id); |
| if let Some(def) = cx.tables.type_dependent_defs().get(hir_id) { |
| let def_id = def.def_id(); |
| let substs = cx.tables.node_substs(hir_id); |
| if method_call_refers_to_method(cx, method, def_id, substs, id) { |
| return true; |
| } |
| } else { |
| cx.tcx.sess.delay_span_bug(expr.span, |
| "no type-dependent def for method call"); |
| } |
| } |
| |
| // Check for calls to methods via explicit paths (e.g. `T::method()`). |
| match expr.node { |
| hir::ExprKind::Call(ref callee, _) => { |
| let def = if let hir::ExprKind::Path(ref qpath) = callee.node { |
| cx.tables.qpath_def(qpath, callee.hir_id) |
| } else { |
| return false; |
| }; |
| match def { |
| Def::Method(def_id) => { |
| let substs = cx.tables.node_substs(callee.hir_id); |
| method_call_refers_to_method(cx, method, def_id, substs, id) |
| } |
| _ => false, |
| } |
| } |
| _ => false, |
| } |
| } |
| |
| // Check if the method call to the method with the ID `callee_id` |
| // and instantiated with `callee_substs` refers to method `method`. |
| fn method_call_refers_to_method<'a, 'tcx>(cx: &LateContext<'a, 'tcx>, |
| method: &ty::AssociatedItem, |
| callee_id: DefId, |
| callee_substs: &Substs<'tcx>, |
| expr_id: ast::NodeId) |
| -> bool { |
| let tcx = cx.tcx; |
| let callee_item = tcx.associated_item(callee_id); |
| |
| match callee_item.container { |
| // This is an inherent method, so the `def_id` refers |
| // directly to the method definition. |
| ty::ImplContainer(_) => callee_id == method.def_id, |
| |
| // A trait method, from any number of possible sources. |
| // Attempt to select a concrete impl before checking. |
| ty::TraitContainer(trait_def_id) => { |
| let trait_ref = ty::TraitRef::from_method(tcx, trait_def_id, callee_substs); |
| let trait_ref = ty::Binder::bind(trait_ref); |
| let span = tcx.hir.span(expr_id); |
| let obligation = |
| traits::Obligation::new(traits::ObligationCause::misc(span, expr_id), |
| cx.param_env, |
| trait_ref.to_poly_trait_predicate()); |
| |
| tcx.infer_ctxt().enter(|infcx| { |
| let mut selcx = traits::SelectionContext::new(&infcx); |
| match selcx.select(&obligation) { |
| // The method comes from a `T: Trait` bound. |
| // If `T` is `Self`, then this call is inside |
| // a default method definition. |
| Ok(Some(traits::VtableParam(_))) => { |
| let on_self = trait_ref.self_ty().is_self(); |
| // We can only be recurring in a default |
| // method if we're being called literally |
| // on the `Self` type. |
| on_self && callee_id == method.def_id |
| } |
| |
| // The `impl` is known, so we check that with a |
| // special case: |
| Ok(Some(traits::VtableImpl(vtable_impl))) => { |
| let container = ty::ImplContainer(vtable_impl.impl_def_id); |
| // It matches if it comes from the same impl, |
| // and has the same method name. |
| container == method.container && |
| callee_item.ident.name == method.ident.name |
| } |
| |
| // There's no way to know if this call is |
| // recursive, so we assume it's not. |
| _ => false, |
| } |
| }) |
| } |
| } |
| } |
| } |
| } |
| |
| declare_lint! { |
| PLUGIN_AS_LIBRARY, |
| Warn, |
| "compiler plugin used as ordinary library in non-plugin crate" |
| } |
| |
| #[derive(Copy, Clone)] |
| pub struct PluginAsLibrary; |
| |
| impl LintPass for PluginAsLibrary { |
| fn get_lints(&self) -> LintArray { |
| lint_array![PLUGIN_AS_LIBRARY] |
| } |
| } |
| |
| impl<'a, 'tcx> LateLintPass<'a, 'tcx> for PluginAsLibrary { |
| fn check_item(&mut self, cx: &LateContext, it: &hir::Item) { |
| if cx.sess().plugin_registrar_fn.get().is_some() { |
| // We're compiling a plugin; it's fine to link other plugins. |
| return; |
| } |
| |
| match it.node { |
| hir::ItemKind::ExternCrate(..) => (), |
| _ => return, |
| }; |
| |
| let def_id = cx.tcx.hir.local_def_id(it.id); |
| let prfn = match cx.tcx.extern_mod_stmt_cnum(def_id) { |
| Some(cnum) => cx.tcx.plugin_registrar_fn(cnum), |
| None => { |
| // Probably means we aren't linking the crate for some reason. |
| // |
| // Not sure if / when this could happen. |
| return; |
| } |
| }; |
| |
| if prfn.is_some() { |
| cx.span_lint(PLUGIN_AS_LIBRARY, |
| it.span, |
| "compiler plugin used as an ordinary library"); |
| } |
| } |
| } |
| |
| declare_lint! { |
| PRIVATE_NO_MANGLE_FNS, |
| Warn, |
| "functions marked #[no_mangle] should be exported" |
| } |
| |
| declare_lint! { |
| PRIVATE_NO_MANGLE_STATICS, |
| Warn, |
| "statics marked #[no_mangle] should be exported" |
| } |
| |
| declare_lint! { |
| NO_MANGLE_CONST_ITEMS, |
| Deny, |
| "const items will not have their symbols exported" |
| } |
| |
| declare_lint! { |
| NO_MANGLE_GENERIC_ITEMS, |
| Warn, |
| "generic items must be mangled" |
| } |
| |
| #[derive(Copy, Clone)] |
| pub struct InvalidNoMangleItems; |
| |
| impl LintPass for InvalidNoMangleItems { |
| fn get_lints(&self) -> LintArray { |
| lint_array!(PRIVATE_NO_MANGLE_FNS, |
| PRIVATE_NO_MANGLE_STATICS, |
| NO_MANGLE_CONST_ITEMS, |
| NO_MANGLE_GENERIC_ITEMS) |
| } |
| } |
| |
| impl<'a, 'tcx> LateLintPass<'a, 'tcx> for InvalidNoMangleItems { |
| fn check_item(&mut self, cx: &LateContext, it: &hir::Item) { |
| let suggest_export = |vis: &hir::Visibility, err: &mut DiagnosticBuilder| { |
| let suggestion = match vis.node { |
| hir::VisibilityKind::Inherited => { |
| // inherited visibility is empty span at item start; need an extra space |
| Some("pub ".to_owned()) |
| }, |
| hir::VisibilityKind::Restricted { .. } | |
| hir::VisibilityKind::Crate(_) => { |
| Some("pub".to_owned()) |
| }, |
| hir::VisibilityKind::Public => { |
| err.help("try exporting the item with a `pub use` statement"); |
| None |
| } |
| }; |
| if let Some(replacement) = suggestion { |
| err.span_suggestion_with_applicability( |
| vis.span, |
| "try making it public", |
| replacement, |
| Applicability::MachineApplicable |
| ); |
| } |
| }; |
| |
| match it.node { |
| hir::ItemKind::Fn(.., ref generics, _) => { |
| if let Some(no_mangle_attr) = attr::find_by_name(&it.attrs, "no_mangle") { |
| if attr::contains_name(&it.attrs, "linkage") { |
| return; |
| } |
| if !cx.access_levels.is_reachable(it.id) { |
| let msg = "function is marked #[no_mangle], but not exported"; |
| let mut err = cx.struct_span_lint(PRIVATE_NO_MANGLE_FNS, it.span, msg); |
| suggest_export(&it.vis, &mut err); |
| err.emit(); |
| } |
| for param in &generics.params { |
| match param.kind { |
| GenericParamKind::Lifetime { .. } => {} |
| GenericParamKind::Type { .. } => { |
| let mut err = cx.struct_span_lint(NO_MANGLE_GENERIC_ITEMS, |
| it.span, |
| "functions generic over \ |
| types must be mangled"); |
| err.span_suggestion_short_with_applicability( |
| no_mangle_attr.span, |
| "remove this attribute", |
| "".to_owned(), |
| // Use of `#[no_mangle]` suggests FFI intent; correct |
| // fix may be to monomorphize source by hand |
| Applicability::MaybeIncorrect |
| ); |
| err.emit(); |
| break; |
| } |
| } |
| } |
| } |
| } |
| hir::ItemKind::Static(..) => { |
| if attr::contains_name(&it.attrs, "no_mangle") && |
| !cx.access_levels.is_reachable(it.id) { |
| let msg = "static is marked #[no_mangle], but not exported"; |
| let mut err = cx.struct_span_lint(PRIVATE_NO_MANGLE_STATICS, it.span, msg); |
| suggest_export(&it.vis, &mut err); |
| err.emit(); |
| } |
| } |
| hir::ItemKind::Const(..) => { |
| if attr::contains_name(&it.attrs, "no_mangle") { |
| // Const items do not refer to a particular location in memory, and therefore |
| // don't have anything to attach a symbol to |
| let msg = "const items should never be #[no_mangle]"; |
| let mut err = cx.struct_span_lint(NO_MANGLE_CONST_ITEMS, it.span, msg); |
| |
| // account for "pub const" (#45562) |
| let start = cx.tcx.sess.source_map().span_to_snippet(it.span) |
| .map(|snippet| snippet.find("const").unwrap_or(0)) |
| .unwrap_or(0) as u32; |
| // `const` is 5 chars |
| let const_span = it.span.with_hi(BytePos(it.span.lo().0 + start + 5)); |
| err.span_suggestion_with_applicability( |
| const_span, |
| "try a static value", |
| "pub static".to_owned(), |
| Applicability::MachineApplicable |
| ); |
| err.emit(); |
| } |
| } |
| _ => {} |
| } |
| } |
| } |
| |
| #[derive(Clone, Copy)] |
| pub struct MutableTransmutes; |
| |
| declare_lint! { |
| MUTABLE_TRANSMUTES, |
| Deny, |
| "mutating transmuted &mut T from &T may cause undefined behavior" |
| } |
| |
| impl LintPass for MutableTransmutes { |
| fn get_lints(&self) -> LintArray { |
| lint_array!(MUTABLE_TRANSMUTES) |
| } |
| } |
| |
| impl<'a, 'tcx> LateLintPass<'a, 'tcx> for MutableTransmutes { |
| fn check_expr(&mut self, cx: &LateContext, expr: &hir::Expr) { |
| use rustc_target::spec::abi::Abi::RustIntrinsic; |
| |
| let msg = "mutating transmuted &mut T from &T may cause undefined behavior, \ |
| consider instead using an UnsafeCell"; |
| match get_transmute_from_to(cx, expr) { |
| Some((&ty::TyRef(_, _, from_mt), &ty::TyRef(_, _, to_mt))) => { |
| if to_mt == hir::Mutability::MutMutable && |
| from_mt == hir::Mutability::MutImmutable { |
| cx.span_lint(MUTABLE_TRANSMUTES, expr.span, msg); |
| } |
| } |
| _ => (), |
| } |
| |
| fn get_transmute_from_to<'a, 'tcx> |
| (cx: &LateContext<'a, 'tcx>, |
| expr: &hir::Expr) |
| -> Option<(&'tcx ty::TypeVariants<'tcx>, &'tcx ty::TypeVariants<'tcx>)> { |
| let def = if let hir::ExprKind::Path(ref qpath) = expr.node { |
| cx.tables.qpath_def(qpath, expr.hir_id) |
| } else { |
| return None; |
| }; |
| if let Def::Fn(did) = def { |
| if !def_id_is_transmute(cx, did) { |
| return None; |
| } |
| let sig = cx.tables.node_id_to_type(expr.hir_id).fn_sig(cx.tcx); |
| let from = sig.inputs().skip_binder()[0]; |
| let to = *sig.output().skip_binder(); |
| return Some((&from.sty, &to.sty)); |
| } |
| None |
| } |
| |
| fn def_id_is_transmute(cx: &LateContext, def_id: DefId) -> bool { |
| cx.tcx.fn_sig(def_id).abi() == RustIntrinsic && |
| cx.tcx.item_name(def_id) == "transmute" |
| } |
| } |
| } |
| |
| /// Forbids using the `#[feature(...)]` attribute |
| #[derive(Copy, Clone)] |
| pub struct UnstableFeatures; |
| |
| declare_lint! { |
| UNSTABLE_FEATURES, |
| Allow, |
| "enabling unstable features (deprecated. do not use)" |
| } |
| |
| impl LintPass for UnstableFeatures { |
| fn get_lints(&self) -> LintArray { |
| lint_array!(UNSTABLE_FEATURES) |
| } |
| } |
| |
| impl<'a, 'tcx> LateLintPass<'a, 'tcx> for UnstableFeatures { |
| fn check_attribute(&mut self, ctx: &LateContext, attr: &ast::Attribute) { |
| if attr.check_name("feature") { |
| if let Some(items) = attr.meta_item_list() { |
| for item in items { |
| ctx.span_lint(UNSTABLE_FEATURES, item.span(), "unstable feature"); |
| } |
| } |
| } |
| } |
| } |
| |
| /// Lint for unions that contain fields with possibly non-trivial destructors. |
| pub struct UnionsWithDropFields; |
| |
| declare_lint! { |
| UNIONS_WITH_DROP_FIELDS, |
| Warn, |
| "use of unions that contain fields with possibly non-trivial drop code" |
| } |
| |
| impl LintPass for UnionsWithDropFields { |
| fn get_lints(&self) -> LintArray { |
| lint_array!(UNIONS_WITH_DROP_FIELDS) |
| } |
| } |
| |
| impl<'a, 'tcx> LateLintPass<'a, 'tcx> for UnionsWithDropFields { |
| fn check_item(&mut self, ctx: &LateContext, item: &hir::Item) { |
| if let hir::ItemKind::Union(ref vdata, _) = item.node { |
| for field in vdata.fields() { |
| let field_ty = ctx.tcx.type_of(ctx.tcx.hir.local_def_id(field.id)); |
| if field_ty.needs_drop(ctx.tcx, ctx.param_env) { |
| ctx.span_lint(UNIONS_WITH_DROP_FIELDS, |
| field.span, |
| "union contains a field with possibly non-trivial drop code, \ |
| drop code of union fields is ignored when dropping the union"); |
| return; |
| } |
| } |
| } |
| } |
| } |
| |
| /// Lint for items marked `pub` that aren't reachable from other crates |
| pub struct UnreachablePub; |
| |
| declare_lint! { |
| pub UNREACHABLE_PUB, |
| Allow, |
| "`pub` items not reachable from crate root" |
| } |
| |
| impl LintPass for UnreachablePub { |
| fn get_lints(&self) -> LintArray { |
| lint_array!(UNREACHABLE_PUB) |
| } |
| } |
| |
| impl UnreachablePub { |
| fn perform_lint(&self, cx: &LateContext, what: &str, id: ast::NodeId, |
| vis: &hir::Visibility, span: Span, exportable: bool) { |
| let mut applicability = Applicability::MachineApplicable; |
| match vis.node { |
| hir::VisibilityKind::Public if !cx.access_levels.is_reachable(id) => { |
| if span.ctxt().outer().expn_info().is_some() { |
| applicability = Applicability::MaybeIncorrect; |
| } |
| let def_span = cx.tcx.sess.source_map().def_span(span); |
| let mut err = cx.struct_span_lint(UNREACHABLE_PUB, def_span, |
| &format!("unreachable `pub` {}", what)); |
| let replacement = if cx.tcx.features().crate_visibility_modifier { |
| "crate" |
| } else { |
| "pub(crate)" |
| }.to_owned(); |
| |
| err.span_suggestion_with_applicability(vis.span, |
| "consider restricting its visibility", |
| replacement, |
| applicability); |
| if exportable { |
| err.help("or consider exporting it for use by other crates"); |
| } |
| err.emit(); |
| }, |
| _ => {} |
| } |
| } |
| } |
| |
| |
| impl<'a, 'tcx> LateLintPass<'a, 'tcx> for UnreachablePub { |
| fn check_item(&mut self, cx: &LateContext, item: &hir::Item) { |
| self.perform_lint(cx, "item", item.id, &item.vis, item.span, true); |
| } |
| |
| fn check_foreign_item(&mut self, cx: &LateContext, foreign_item: &hir::ForeignItem) { |
| self.perform_lint(cx, "item", foreign_item.id, &foreign_item.vis, |
| foreign_item.span, true); |
| } |
| |
| fn check_struct_field(&mut self, cx: &LateContext, field: &hir::StructField) { |
| self.perform_lint(cx, "field", field.id, &field.vis, field.span, false); |
| } |
| |
| fn check_impl_item(&mut self, cx: &LateContext, impl_item: &hir::ImplItem) { |
| self.perform_lint(cx, "item", impl_item.id, &impl_item.vis, impl_item.span, false); |
| } |
| } |
| |
| /// Lint for trait and lifetime bounds in type aliases being mostly ignored: |
| /// They are relevant when using associated types, but otherwise neither checked |
| /// at definition site nor enforced at use site. |
| |
| pub struct TypeAliasBounds; |
| |
| declare_lint! { |
| TYPE_ALIAS_BOUNDS, |
| Warn, |
| "bounds in type aliases are not enforced" |
| } |
| |
| impl LintPass for TypeAliasBounds { |
| fn get_lints(&self) -> LintArray { |
| lint_array!(TYPE_ALIAS_BOUNDS) |
| } |
| } |
| |
| impl TypeAliasBounds { |
| fn is_type_variable_assoc(qpath: &hir::QPath) -> bool { |
| match *qpath { |
| hir::QPath::TypeRelative(ref ty, _) => { |
| // If this is a type variable, we found a `T::Assoc`. |
| match ty.node { |
| hir::TyKind::Path(hir::QPath::Resolved(None, ref path)) => { |
| match path.def { |
| Def::TyParam(_) => true, |
| _ => false |
| } |
| } |
| _ => false |
| } |
| } |
| hir::QPath::Resolved(..) => false, |
| } |
| } |
| |
| fn suggest_changing_assoc_types(ty: &hir::Ty, err: &mut DiagnosticBuilder) { |
| // Access to associates types should use `<T as Bound>::Assoc`, which does not need a |
| // bound. Let's see if this type does that. |
| |
| // We use a HIR visitor to walk the type. |
| use rustc::hir::intravisit::{self, Visitor}; |
| struct WalkAssocTypes<'a, 'db> where 'db: 'a { |
| err: &'a mut DiagnosticBuilder<'db> |
| } |
| impl<'a, 'db, 'v> Visitor<'v> for WalkAssocTypes<'a, 'db> { |
| fn nested_visit_map<'this>(&'this mut self) -> intravisit::NestedVisitorMap<'this, 'v> |
| { |
| intravisit::NestedVisitorMap::None |
| } |
| |
| fn visit_qpath(&mut self, qpath: &'v hir::QPath, id: hir::HirId, span: Span) { |
| if TypeAliasBounds::is_type_variable_assoc(qpath) { |
| self.err.span_help(span, |
| "use fully disambiguated paths (i.e., `<T as Trait>::Assoc`) to refer to \ |
| associated types in type aliases"); |
| } |
| intravisit::walk_qpath(self, qpath, id, span) |
| } |
| } |
| |
| // Let's go for a walk! |
| let mut visitor = WalkAssocTypes { err }; |
| visitor.visit_ty(ty); |
| } |
| } |
| |
| impl<'a, 'tcx> LateLintPass<'a, 'tcx> for TypeAliasBounds { |
| fn check_item(&mut self, cx: &LateContext, item: &hir::Item) { |
| let (ty, type_alias_generics) = match item.node { |
| hir::ItemKind::Ty(ref ty, ref generics) => (&*ty, generics), |
| _ => return, |
| }; |
| let mut suggested_changing_assoc_types = false; |
| // There must not be a where clause |
| if !type_alias_generics.where_clause.predicates.is_empty() { |
| let spans : Vec<_> = type_alias_generics.where_clause.predicates.iter() |
| .map(|pred| pred.span()).collect(); |
| let mut err = cx.struct_span_lint(TYPE_ALIAS_BOUNDS, spans, |
| "where clauses are not enforced in type aliases"); |
| err.help("the clause will not be checked when the type alias is used, \ |
| and should be removed"); |
| if !suggested_changing_assoc_types { |
| TypeAliasBounds::suggest_changing_assoc_types(ty, &mut err); |
| suggested_changing_assoc_types = true; |
| } |
| err.emit(); |
| } |
| // The parameters must not have bounds |
| for param in type_alias_generics.params.iter() { |
| let spans: Vec<_> = param.bounds.iter().map(|b| b.span()).collect(); |
| if !spans.is_empty() { |
| let mut err = cx.struct_span_lint( |
| TYPE_ALIAS_BOUNDS, |
| spans, |
| "bounds on generic parameters are not enforced in type aliases", |
| ); |
| err.help("the bound will not be checked when the type alias is used, \ |
| and should be removed"); |
| if !suggested_changing_assoc_types { |
| TypeAliasBounds::suggest_changing_assoc_types(ty, &mut err); |
| suggested_changing_assoc_types = true; |
| } |
| err.emit(); |
| } |
| } |
| } |
| } |
| |
| /// Lint constants that are erroneous. |
| /// Without this lint, we might not get any diagnostic if the constant is |
| /// unused within this crate, even though downstream crates can't use it |
| /// without producing an error. |
| pub struct UnusedBrokenConst; |
| |
| impl LintPass for UnusedBrokenConst { |
| fn get_lints(&self) -> LintArray { |
| lint_array!() |
| } |
| } |
| |
| fn validate_const<'a, 'tcx>( |
| tcx: ty::TyCtxt<'a, 'tcx, 'tcx>, |
| constant: &ty::Const<'tcx>, |
| param_env: ty::ParamEnv<'tcx>, |
| gid: ::rustc::mir::interpret::GlobalId<'tcx>, |
| what: &str, |
| ) { |
| let mut ecx = ::rustc_mir::interpret::mk_eval_cx(tcx, gid.instance, param_env).unwrap(); |
| let result = (|| { |
| let val = ecx.const_to_value(constant.val)?; |
| use rustc_target::abi::LayoutOf; |
| let layout = ecx.layout_of(constant.ty)?; |
| let place = ecx.allocate_place_for_value(val, layout, None)?; |
| let ptr = place.to_ptr()?; |
| let mut todo = vec![(ptr, layout.ty, String::new())]; |
| let mut seen = FxHashSet(); |
| seen.insert((ptr, layout.ty)); |
| while let Some((ptr, ty, path)) = todo.pop() { |
| let layout = ecx.layout_of(ty)?; |
| ecx.validate_ptr_target( |
| ptr, |
| layout.align, |
| layout, |
| path, |
| &mut seen, |
| &mut todo, |
| )?; |
| } |
| Ok(()) |
| })(); |
| if let Err(err) = result { |
| let (trace, span) = ecx.generate_stacktrace(None); |
| let err = ::rustc::mir::interpret::ConstEvalErr { |
| error: err, |
| stacktrace: trace, |
| span, |
| }; |
| let err = err.struct_error( |
| tcx.at(span), |
| &format!("this {} likely exhibits undefined behavior", what), |
| ); |
| if let Some(mut err) = err { |
| err.note("The rules on what exactly is undefined behavior aren't clear, \ |
| so this check might be overzealous. Please open an issue on the rust compiler \ |
| repository if you believe it should not be considered undefined behavior", |
| ); |
| err.emit(); |
| } |
| } |
| } |
| |
| fn check_const(cx: &LateContext, body_id: hir::BodyId, what: &str) { |
| let def_id = cx.tcx.hir.body_owner_def_id(body_id); |
| let is_static = cx.tcx.is_static(def_id).is_some(); |
| let param_env = if is_static { |
| // Use the same param_env as `codegen_static_initializer`, to reuse the cache. |
| ty::ParamEnv::reveal_all() |
| } else { |
| cx.tcx.param_env(def_id) |
| }; |
| let cid = ::rustc::mir::interpret::GlobalId { |
| instance: ty::Instance::mono(cx.tcx, def_id), |
| promoted: None |
| }; |
| match cx.tcx.const_eval(param_env.and(cid)) { |
| Ok(val) => validate_const(cx.tcx, val, param_env, cid, what), |
| Err(err) => { |
| // errors for statics are already reported directly in the query, avoid duplicates |
| if !is_static { |
| let span = cx.tcx.def_span(def_id); |
| err.report_as_lint( |
| cx.tcx.at(span), |
| &format!("this {} cannot be used", what), |
| cx.current_lint_root(), |
| ); |
| } |
| }, |
| } |
| } |
| |
| struct UnusedBrokenConstVisitor<'a, 'tcx: 'a>(&'a LateContext<'a, 'tcx>); |
| |
| impl<'a, 'tcx, 'v> hir::intravisit::Visitor<'v> for UnusedBrokenConstVisitor<'a, 'tcx> { |
| fn visit_nested_body(&mut self, id: hir::BodyId) { |
| check_const(self.0, id, "array length"); |
| } |
| fn nested_visit_map<'this>(&'this mut self) -> hir::intravisit::NestedVisitorMap<'this, 'v> { |
| hir::intravisit::NestedVisitorMap::None |
| } |
| } |
| |
| impl<'a, 'tcx> LateLintPass<'a, 'tcx> for UnusedBrokenConst { |
| fn check_item(&mut self, cx: &LateContext, it: &hir::Item) { |
| match it.node { |
| hir::ItemKind::Const(_, body_id) => { |
| check_const(cx, body_id, "constant"); |
| }, |
| hir::ItemKind::Static(_, _, body_id) => { |
| check_const(cx, body_id, "static"); |
| }, |
| hir::ItemKind::Ty(ref ty, _) => hir::intravisit::walk_ty( |
| &mut UnusedBrokenConstVisitor(cx), |
| ty |
| ), |
| _ => {}, |
| } |
| } |
| } |
| |
| /// Lint for trait and lifetime bounds that don't depend on type parameters |
| /// which either do nothing, or stop the item from being used. |
| pub struct TrivialConstraints; |
| |
| declare_lint! { |
| TRIVIAL_BOUNDS, |
| Warn, |
| "these bounds don't depend on an type parameters" |
| } |
| |
| impl LintPass for TrivialConstraints { |
| fn get_lints(&self) -> LintArray { |
| lint_array!(TRIVIAL_BOUNDS) |
| } |
| } |
| |
| impl<'a, 'tcx> LateLintPass<'a, 'tcx> for TrivialConstraints { |
| fn check_item( |
| &mut self, |
| cx: &LateContext<'a, 'tcx>, |
| item: &'tcx hir::Item, |
| ) { |
| use rustc::ty::fold::TypeFoldable; |
| use rustc::ty::Predicate::*; |
| |
| |
| if cx.tcx.features().trivial_bounds { |
| let def_id = cx.tcx.hir.local_def_id(item.id); |
| let predicates = cx.tcx.predicates_of(def_id); |
| for predicate in &predicates.predicates { |
| let predicate_kind_name = match *predicate { |
| Trait(..) => "Trait", |
| TypeOutlives(..) | |
| RegionOutlives(..) => "Lifetime", |
| |
| // Ignore projections, as they can only be global |
| // if the trait bound is global |
| Projection(..) | |
| // Ignore bounds that a user can't type |
| WellFormed(..) | |
| ObjectSafe(..) | |
| ClosureKind(..) | |
| Subtype(..) | |
| ConstEvaluatable(..) => continue, |
| }; |
| if predicate.is_global() { |
| cx.span_lint( |
| TRIVIAL_BOUNDS, |
| item.span, |
| &format!("{} bound {} does not depend on any type \ |
| or lifetime parameters", predicate_kind_name, predicate), |
| ); |
| } |
| } |
| } |
| } |
| } |
| |
| |
| /// Does nothing as a lint pass, but registers some `Lint`s |
| /// which are used by other parts of the compiler. |
| #[derive(Copy, Clone)] |
| pub struct SoftLints; |
| |
| impl LintPass for SoftLints { |
| fn get_lints(&self) -> LintArray { |
| lint_array!( |
| WHILE_TRUE, |
| BOX_POINTERS, |
| NON_SHORTHAND_FIELD_PATTERNS, |
| UNSAFE_CODE, |
| MISSING_DOCS, |
| MISSING_COPY_IMPLEMENTATIONS, |
| MISSING_DEBUG_IMPLEMENTATIONS, |
| ANONYMOUS_PARAMETERS, |
| UNUSED_DOC_COMMENTS, |
| UNCONDITIONAL_RECURSION, |
| PLUGIN_AS_LIBRARY, |
| PRIVATE_NO_MANGLE_FNS, |
| PRIVATE_NO_MANGLE_STATICS, |
| NO_MANGLE_CONST_ITEMS, |
| NO_MANGLE_GENERIC_ITEMS, |
| MUTABLE_TRANSMUTES, |
| UNSTABLE_FEATURES, |
| UNIONS_WITH_DROP_FIELDS, |
| UNREACHABLE_PUB, |
| TYPE_ALIAS_BOUNDS, |
| TRIVIAL_BOUNDS |
| ) |
| } |
| } |
| |
| declare_lint! { |
| pub ELLIPSIS_INCLUSIVE_RANGE_PATTERNS, |
| Allow, |
| "`...` range patterns are deprecated" |
| } |
| |
| |
| pub struct EllipsisInclusiveRangePatterns; |
| |
| impl LintPass for EllipsisInclusiveRangePatterns { |
| fn get_lints(&self) -> LintArray { |
| lint_array!(ELLIPSIS_INCLUSIVE_RANGE_PATTERNS) |
| } |
| } |
| |
| impl EarlyLintPass for EllipsisInclusiveRangePatterns { |
| fn check_pat(&mut self, cx: &EarlyContext, pat: &ast::Pat) { |
| use self::ast::{PatKind, RangeEnd, RangeSyntax}; |
| |
| if let PatKind::Range( |
| _, _, Spanned { span, node: RangeEnd::Included(RangeSyntax::DotDotDot) } |
| ) = pat.node { |
| let msg = "`...` range patterns are deprecated"; |
| let mut err = cx.struct_span_lint(ELLIPSIS_INCLUSIVE_RANGE_PATTERNS, span, msg); |
| err.span_suggestion_short_with_applicability( |
| span, "use `..=` for an inclusive range", "..=".to_owned(), |
| // FIXME: outstanding problem with precedence in ref patterns: |
| // https://github.com/rust-lang/rust/issues/51043#issuecomment-392252285 |
| Applicability::MaybeIncorrect |
| ); |
| err.emit() |
| } |
| } |
| } |
| |
| declare_lint! { |
| UNNAMEABLE_TEST_FUNCTIONS, |
| Warn, |
| "detects an function that cannot be named being marked as #[test]" |
| } |
| |
| pub struct UnnameableTestFunctions; |
| |
| impl LintPass for UnnameableTestFunctions { |
| fn get_lints(&self) -> LintArray { |
| lint_array!(UNNAMEABLE_TEST_FUNCTIONS) |
| } |
| } |
| |
| impl<'a, 'tcx> LateLintPass<'a, 'tcx> for UnnameableTestFunctions { |
| fn check_item(&mut self, cx: &LateContext, it: &hir::Item) { |
| match it.node { |
| hir::ItemKind::Fn(..) => { |
| for attr in &it.attrs { |
| if attr.name() == "test" { |
| let parent = cx.tcx.hir.get_parent(it.id); |
| match cx.tcx.hir.find(parent) { |
| Some(hir_map::NodeItem(hir::Item {node: hir::ItemKind::Mod(_), ..})) | |
| None => {} |
| _ => { |
| cx.struct_span_lint( |
| UNNAMEABLE_TEST_FUNCTIONS, |
| attr.span, |
| "cannot test inner function", |
| ).emit(); |
| } |
| } |
| break; |
| } |
| } |
| } |
| _ => return, |
| }; |
| } |
| } |
| |
| declare_lint! { |
| pub ASYNC_IDENTS, |
| Allow, |
| "detects `async` being used as an identifier" |
| } |
| |
| /// Checks for uses of `async` as an identifier |
| #[derive(Clone)] |
| pub struct Async2018; |
| |
| impl LintPass for Async2018 { |
| fn get_lints(&self) -> LintArray { |
| lint_array!(ASYNC_IDENTS) |
| } |
| } |
| |
| impl Async2018 { |
| fn check_tokens(&mut self, cx: &EarlyContext, tokens: TokenStream) { |
| for tt in tokens.into_trees() { |
| match tt { |
| TokenTree::Token(span, tok) => match tok.ident() { |
| // only report non-raw idents |
| Some((ident, false)) if ident.as_str() == "async" => { |
| self.report(cx, span.substitute_dummy(ident.span)) |
| }, |
| _ => {}, |
| } |
| TokenTree::Delimited(_, ref delim) => { |
| self.check_tokens(cx, delim.tts.clone().into()) |
| }, |
| } |
| } |
| } |
| fn report(&mut self, cx: &EarlyContext, span: Span) { |
| // don't lint `r#async` |
| if cx.sess.parse_sess.raw_identifier_spans.borrow().contains(&span) { |
| return; |
| } |
| let mut lint = cx.struct_span_lint( |
| ASYNC_IDENTS, |
| span, |
| "`async` is a keyword in the 2018 edition", |
| ); |
| |
| // Don't suggest about raw identifiers if the feature isn't active |
| if cx.sess.features_untracked().raw_identifiers { |
| lint.span_suggestion_with_applicability( |
| span, |
| "you can use a raw identifier to stay compatible", |
| "r#async".to_string(), |
| Applicability::MachineApplicable, |
| ); |
| } |
| lint.emit() |
| } |
| } |
| |
| impl EarlyLintPass for Async2018 { |
| fn check_mac_def(&mut self, cx: &EarlyContext, mac_def: &ast::MacroDef, _id: ast::NodeId) { |
| self.check_tokens(cx, mac_def.stream()); |
| } |
| fn check_mac(&mut self, cx: &EarlyContext, mac: &ast::Mac) { |
| self.check_tokens(cx, mac.node.tts.clone().into()); |
| } |
| fn check_ident(&mut self, cx: &EarlyContext, ident: ast::Ident) { |
| if ident.as_str() == "async" { |
| self.report(cx, ident.span); |
| } |
| } |
| } |
