diff options
Diffstat (limited to 'compiler/rustc_lint/src')
| -rw-r--r-- | compiler/rustc_lint/src/builtin.rs | 105 | ||||
| -rw-r--r-- | compiler/rustc_lint/src/context.rs | 104 | ||||
| -rw-r--r-- | compiler/rustc_lint/src/drop_forget_useless.rs | 164 | ||||
| -rw-r--r-- | compiler/rustc_lint/src/early.rs | 2 | ||||
| -rw-r--r-- | compiler/rustc_lint/src/enum_intrinsics_non_enums.rs | 2 | ||||
| -rw-r--r-- | compiler/rustc_lint/src/errors.rs | 2 | ||||
| -rw-r--r-- | compiler/rustc_lint/src/expect.rs | 2 | ||||
| -rw-r--r-- | compiler/rustc_lint/src/internal.rs | 87 | ||||
| -rw-r--r-- | compiler/rustc_lint/src/late.rs | 10 | ||||
| -rw-r--r-- | compiler/rustc_lint/src/levels.rs | 14 | ||||
| -rw-r--r-- | compiler/rustc_lint/src/lib.rs | 8 | ||||
| -rw-r--r-- | compiler/rustc_lint/src/lints.rs | 53 | ||||
| -rw-r--r-- | compiler/rustc_lint/src/non_fmt_panic.rs | 2 | ||||
| -rw-r--r-- | compiler/rustc_lint/src/nonstandard_style.rs | 8 | ||||
| -rw-r--r-- | compiler/rustc_lint/src/noop_method_call.rs | 117 | ||||
| -rw-r--r-- | compiler/rustc_lint/src/opaque_hidden_inferred_bound.rs | 4 | ||||
| -rw-r--r-- | compiler/rustc_lint/src/types.rs | 6 | ||||
| -rw-r--r-- | compiler/rustc_lint/src/unused.rs | 95 |
18 files changed, 592 insertions, 193 deletions
diff --git a/compiler/rustc_lint/src/builtin.rs b/compiler/rustc_lint/src/builtin.rs index 6b387df78..85141836e 100644 --- a/compiler/rustc_lint/src/builtin.rs +++ b/compiler/rustc_lint/src/builtin.rs @@ -22,7 +22,7 @@ use crate::fluent_generated as fluent; use crate::{ - errors::BuiltinEllpisisInclusiveRangePatterns, + errors::BuiltinEllipsisInclusiveRangePatterns, lints::{ BuiltinAnonymousParams, BuiltinBoxPointers, BuiltinClashingExtern, BuiltinClashingExternSub, BuiltinConstNoMangle, BuiltinDeprecatedAttrLink, @@ -62,7 +62,9 @@ use rustc_middle::lint::in_external_macro; use rustc_middle::ty::layout::{LayoutError, LayoutOf}; use rustc_middle::ty::print::with_no_trimmed_paths; use rustc_middle::ty::subst::GenericArgKind; +use rustc_middle::ty::TypeVisitableExt; use rustc_middle::ty::{self, Instance, Ty, TyCtxt, VariantDef}; +use rustc_session::config::ExpectedValues; use rustc_session::lint::{BuiltinLintDiagnostics, FutureIncompatibilityReason}; use rustc_span::edition::Edition; use rustc_span::source_map::Spanned; @@ -116,8 +118,7 @@ impl EarlyLintPass for WhileTrue { #[inline] fn check_expr(&mut self, cx: &EarlyContext<'_>, e: &ast::Expr) { if let ast::ExprKind::While(cond, _, label) = &e.kind - && let cond = pierce_parens(cond) - && let ast::ExprKind::Lit(token_lit) = cond.kind + && let ast::ExprKind::Lit(token_lit) = pierce_parens(cond).kind && let token::Lit { kind: token::Bool, symbol: kw::True, .. } = token_lit && !cond.span.from_expansion() { @@ -166,10 +167,8 @@ declare_lint_pass!(BoxPointers => [BOX_POINTERS]); impl BoxPointers { fn check_heap_type(&self, cx: &LateContext<'_>, span: Span, ty: Ty<'_>) { for leaf in ty.walk() { - if let GenericArgKind::Type(leaf_ty) = leaf.unpack() { - if leaf_ty.is_box() { - cx.emit_spanned_lint(BOX_POINTERS, span, BuiltinBoxPointers { ty }); - } + if let GenericArgKind::Type(leaf_ty) = leaf.unpack() && leaf_ty.is_box() { + cx.emit_spanned_lint(BOX_POINTERS, span, BuiltinBoxPointers { ty }); } } } @@ -548,32 +547,17 @@ impl<'tcx> LateLintPass<'tcx> for MissingDoc { } fn check_item(&mut self, cx: &LateContext<'_>, it: &hir::Item<'_>) { - match it.kind { - hir::ItemKind::Trait(..) => { - // Issue #11592: traits are always considered exported, even when private. - if cx.tcx.visibility(it.owner_id) - == ty::Visibility::Restricted( - cx.tcx.parent_module_from_def_id(it.owner_id.def_id).to_def_id(), - ) - { - return; - } - } - hir::ItemKind::TyAlias(..) - | hir::ItemKind::Fn(..) - | hir::ItemKind::Macro(..) - | hir::ItemKind::Mod(..) - | hir::ItemKind::Enum(..) - | hir::ItemKind::Struct(..) - | hir::ItemKind::Union(..) - | hir::ItemKind::Const(..) - | hir::ItemKind::Static(..) => {} - - _ => return, - }; + // Previously the Impl and Use types have been excluded from missing docs, + // so we will continue to exclude them for compatibility. + // + // The documentation on `ExternCrate` is not used at the moment so no need to warn for it. + if let hir::ItemKind::Impl(..) | hir::ItemKind::Use(..) | hir::ItemKind::ExternCrate(_) = + it.kind + { + return; + } let (article, desc) = cx.tcx.article_and_description(it.owner_id.to_def_id()); - self.check_missing_docs_attrs(cx, it.owner_id.def_id, article, desc); } @@ -631,7 +615,7 @@ impl<'tcx> LateLintPass<'tcx> for MissingDoc { declare_lint! { /// The `missing_copy_implementations` lint detects potentially-forgotten - /// implementations of [`Copy`]. + /// implementations of [`Copy`] for public types. /// /// [`Copy`]: https://doc.rust-lang.org/std/marker/trait.Copy.html /// @@ -667,7 +651,9 @@ declare_lint_pass!(MissingCopyImplementations => [MISSING_COPY_IMPLEMENTATIONS]) impl<'tcx> LateLintPass<'tcx> for MissingCopyImplementations { fn check_item(&mut self, cx: &LateContext<'_>, item: &hir::Item<'_>) { - if !cx.effective_visibilities.is_reachable(item.owner_id.def_id) { + if !(cx.effective_visibilities.is_reachable(item.owner_id.def_id) + && cx.tcx.local_visibility(item.owner_id.def_id).is_public()) + { return; } let (def, ty) = match item.kind { @@ -747,7 +733,7 @@ impl<'tcx> LateLintPass<'tcx> for MissingCopyImplementations { declare_lint! { /// The `missing_debug_implementations` lint detects missing - /// implementations of [`fmt::Debug`]. + /// implementations of [`fmt::Debug`] for public types. /// /// [`fmt::Debug`]: https://doc.rust-lang.org/std/fmt/trait.Debug.html /// @@ -786,7 +772,9 @@ impl_lint_pass!(MissingDebugImplementations => [MISSING_DEBUG_IMPLEMENTATIONS]); impl<'tcx> LateLintPass<'tcx> for MissingDebugImplementations { fn check_item(&mut self, cx: &LateContext<'_>, item: &hir::Item<'_>) { - if !cx.effective_visibilities.is_reachable(item.owner_id.def_id) { + if !(cx.effective_visibilities.is_reachable(item.owner_id.def_id) + && cx.tcx.local_visibility(item.owner_id.def_id).is_public()) + { return; } @@ -977,7 +965,7 @@ fn warn_if_doc(cx: &EarlyContext<'_>, node_span: Span, node_kind: &str, attrs: & Some(sugared_span.map_or(attr.span, |span| span.with_hi(attr.span.hi()))); } - if attrs.peek().map_or(false, |next_attr| next_attr.is_doc_comment()) { + if attrs.peek().is_some_and(|next_attr| next_attr.is_doc_comment()) { continue; } @@ -1463,6 +1451,10 @@ impl<'tcx> LateLintPass<'tcx> for TypeAliasBounds { // Bounds are respected for `type X = impl Trait` return; } + if cx.tcx.type_of(item.owner_id).skip_binder().has_inherent_projections() { + // Bounds are respected for `type X = … Type::Inherent …` + return; + } // There must not be a where clause if type_alias_generics.predicates.is_empty() { return; @@ -1582,7 +1574,6 @@ declare_lint_pass!( impl<'tcx> LateLintPass<'tcx> for TrivialConstraints { fn check_item(&mut self, cx: &LateContext<'tcx>, item: &'tcx hir::Item<'tcx>) { - use rustc_middle::ty::visit::TypeVisitableExt; use rustc_middle::ty::Clause; use rustc_middle::ty::PredicateKind::*; @@ -1711,13 +1702,13 @@ impl EarlyLintPass for EllipsisInclusiveRangePatterns { } } - let (parenthesise, endpoints) = match &pat.kind { + let (parentheses, endpoints) = match &pat.kind { PatKind::Ref(subpat, _) => (true, matches_ellipsis_pat(&subpat)), _ => (false, matches_ellipsis_pat(pat)), }; if let Some((start, end, join)) = endpoints { - if parenthesise { + if parentheses { self.node_id = Some(pat.id); let end = expr_to_string(&end); let replace = match start { @@ -1725,7 +1716,7 @@ impl EarlyLintPass for EllipsisInclusiveRangePatterns { None => format!("&(..={})", end), }; if join.edition() >= Edition::Edition2021 { - cx.sess().emit_err(BuiltinEllpisisInclusiveRangePatterns { + cx.sess().emit_err(BuiltinEllipsisInclusiveRangePatterns { span: pat.span, suggestion: pat.span, replace, @@ -1743,7 +1734,7 @@ impl EarlyLintPass for EllipsisInclusiveRangePatterns { } else { let replace = "..="; if join.edition() >= Edition::Edition2021 { - cx.sess().emit_err(BuiltinEllpisisInclusiveRangePatterns { + cx.sess().emit_err(BuiltinEllipsisInclusiveRangePatterns { span: pat.span, suggestion: join, replace: replace.to_string(), @@ -1899,8 +1890,8 @@ declare_lint_pass!( struct UnderMacro(bool); impl KeywordIdents { - fn check_tokens(&mut self, cx: &EarlyContext<'_>, tokens: TokenStream) { - for tt in tokens.into_trees() { + fn check_tokens(&mut self, cx: &EarlyContext<'_>, tokens: &TokenStream) { + for tt in tokens.trees() { match tt { // Only report non-raw idents. TokenTree::Token(token, _) => { @@ -1961,10 +1952,10 @@ impl KeywordIdents { impl EarlyLintPass for KeywordIdents { fn check_mac_def(&mut self, cx: &EarlyContext<'_>, mac_def: &ast::MacroDef) { - self.check_tokens(cx, mac_def.body.tokens.clone()); + self.check_tokens(cx, &mac_def.body.tokens); } fn check_mac(&mut self, cx: &EarlyContext<'_>, mac: &ast::MacCall) { - self.check_tokens(cx, mac.args.tokens.clone()); + self.check_tokens(cx, &mac.args.tokens); } fn check_ident(&mut self, cx: &EarlyContext<'_>, ident: Ident) { self.check_ident_token(cx, UnderMacro(false), ident); @@ -2560,7 +2551,7 @@ impl<'tcx> LateLintPass<'tcx> for InvalidValue { .subst(cx.tcx, substs) .apply_any_module(cx.tcx, cx.param_env) { - // Entirely skip uninhbaited variants. + // Entirely skip uninhabited variants. Some(false) => return None, // Forward the others, but remember which ones are definitely inhabited. Some(true) => true, @@ -2628,7 +2619,7 @@ impl<'tcx> LateLintPass<'tcx> for InvalidValue { if let Some(err) = with_no_trimmed_paths!(ty_find_init_error(cx, conjured_ty, init)) { let msg = match init { InitKind::Zeroed => fluent::lint_builtin_unpermitted_type_init_zeroed, - InitKind::Uninit => fluent::lint_builtin_unpermitted_type_init_unint, + InitKind::Uninit => fluent::lint_builtin_unpermitted_type_init_uninit, }; let sub = BuiltinUnpermittedTypeInitSub { err }; cx.emit_spanned_lint( @@ -2919,6 +2910,7 @@ impl ClashingExternDeclarations { | (Generator(..), Generator(..)) | (GeneratorWitness(..), GeneratorWitness(..)) | (Alias(ty::Projection, ..), Alias(ty::Projection, ..)) + | (Alias(ty::Inherent, ..), Alias(ty::Inherent, ..)) | (Alias(ty::Opaque, ..), Alias(ty::Opaque, ..)) => false, // These definitely should have been caught above. @@ -3308,16 +3300,15 @@ impl EarlyLintPass for UnexpectedCfgs { let cfg = &cx.sess().parse_sess.config; let check_cfg = &cx.sess().parse_sess.check_config; for &(name, value) in cfg { - if let Some(names_valid) = &check_cfg.names_valid && !names_valid.contains(&name){ - cx.emit_lint(UNEXPECTED_CFGS, BuiltinUnexpectedCliConfigName { - name, - }); - } - if let Some(value) = value && let Some(values) = check_cfg.values_valid.get(&name) && !values.contains(&value) { - cx.emit_lint( - UNEXPECTED_CFGS, - BuiltinUnexpectedCliConfigValue { name, value }, - ); + match check_cfg.expecteds.get(&name) { + Some(ExpectedValues::Some(values)) if !values.contains(&value) => { + let value = value.unwrap_or(kw::Empty); + cx.emit_lint(UNEXPECTED_CFGS, BuiltinUnexpectedCliConfigValue { name, value }); + } + None if check_cfg.exhaustive_names => { + cx.emit_lint(UNEXPECTED_CFGS, BuiltinUnexpectedCliConfigName { name }); + } + _ => { /* expected */ } } } } diff --git a/compiler/rustc_lint/src/context.rs b/compiler/rustc_lint/src/context.rs index 626c09fea..1d0c43e95 100644 --- a/compiler/rustc_lint/src/context.rs +++ b/compiler/rustc_lint/src/context.rs @@ -36,6 +36,7 @@ use rustc_middle::middle::stability; use rustc_middle::ty::layout::{LayoutError, LayoutOfHelpers, TyAndLayout}; use rustc_middle::ty::print::with_no_trimmed_paths; use rustc_middle::ty::{self, print::Printer, subst::GenericArg, RegisteredTools, Ty, TyCtxt}; +use rustc_session::config::ExpectedValues; use rustc_session::lint::{BuiltinLintDiagnostics, LintExpectationId}; use rustc_session::lint::{FutureIncompatibleInfo, Level, Lint, LintBuffer, LintId}; use rustc_session::Session; @@ -48,9 +49,9 @@ use std::cell::Cell; use std::iter; use std::slice; -type EarlyLintPassFactory = dyn Fn() -> EarlyLintPassObject + sync::Send + sync::Sync; +type EarlyLintPassFactory = dyn Fn() -> EarlyLintPassObject + sync::DynSend + sync::DynSync; type LateLintPassFactory = - dyn for<'tcx> Fn(TyCtxt<'tcx>) -> LateLintPassObject<'tcx> + sync::Send + sync::Sync; + dyn for<'tcx> Fn(TyCtxt<'tcx>) -> LateLintPassObject<'tcx> + sync::DynSend + sync::DynSync; /// Information about the registered lints. /// @@ -168,7 +169,7 @@ impl LintStore { pub fn register_early_pass( &mut self, - pass: impl Fn() -> EarlyLintPassObject + 'static + sync::Send + sync::Sync, + pass: impl Fn() -> EarlyLintPassObject + 'static + sync::DynSend + sync::DynSync, ) { self.early_passes.push(Box::new(pass)); } @@ -181,7 +182,7 @@ impl LintStore { /// * See [rust-clippy#5518](https://github.com/rust-lang/rust-clippy/pull/5518) pub fn register_pre_expansion_pass( &mut self, - pass: impl Fn() -> EarlyLintPassObject + 'static + sync::Send + sync::Sync, + pass: impl Fn() -> EarlyLintPassObject + 'static + sync::DynSend + sync::DynSync, ) { self.pre_expansion_passes.push(Box::new(pass)); } @@ -190,8 +191,8 @@ impl LintStore { &mut self, pass: impl for<'tcx> Fn(TyCtxt<'tcx>) -> LateLintPassObject<'tcx> + 'static - + sync::Send - + sync::Sync, + + sync::DynSend + + sync::DynSync, ) { self.late_passes.push(Box::new(pass)); } @@ -200,8 +201,8 @@ impl LintStore { &mut self, pass: impl for<'tcx> Fn(TyCtxt<'tcx>) -> LateLintPassObject<'tcx> + 'static - + sync::Send - + sync::Sync, + + sync::DynSend + + sync::DynSync, ) { self.late_module_passes.push(Box::new(pass)); } @@ -616,7 +617,7 @@ pub trait LintContext: Sized { 1 => ("an ", ""), _ => ("", "s"), }; - db.span_label(span, &format!( + db.span_label(span, format!( "this comment contains {}invisible unicode text flow control codepoint{}", an, s, @@ -680,12 +681,12 @@ pub trait LintContext: Sized { ); } BuiltinLintDiagnostics::UnknownCrateTypes(span, note, sugg) => { - db.span_suggestion(span, ¬e, sugg, Applicability::MaybeIncorrect); + db.span_suggestion(span, note, sugg, Applicability::MaybeIncorrect); } BuiltinLintDiagnostics::UnusedImports(message, replaces, in_test_module) => { if !replaces.is_empty() { db.tool_only_multipart_suggestion( - &message, + message, replaces, Applicability::MachineApplicable, ); @@ -720,13 +721,13 @@ pub trait LintContext: Sized { } BuiltinLintDiagnostics::MissingAbi(span, default_abi) => { db.span_label(span, "ABI should be specified here"); - db.help(&format!("the default ABI is {}", default_abi.name())); + db.help(format!("the default ABI is {}", default_abi.name())); } BuiltinLintDiagnostics::LegacyDeriveHelpers(span) => { db.span_label(span, "the attribute is introduced here"); } BuiltinLintDiagnostics::ProcMacroBackCompat(note) => { - db.note(¬e); + db.note(note); } BuiltinLintDiagnostics::OrPatternsBackCompat(span,suggestion) => { db.span_suggestion(span, "use pat_param to preserve semantics", suggestion, Applicability::MachineApplicable); @@ -747,13 +748,13 @@ pub trait LintContext: Sized { } => { db.span_note( invoc_span, - &format!("the built-in attribute `{attr_name}` will be ignored, since it's applied to the macro invocation `{macro_name}`") + format!("the built-in attribute `{attr_name}` will be ignored, since it's applied to the macro invocation `{macro_name}`") ); } BuiltinLintDiagnostics::TrailingMacro(is_trailing, name) => { if is_trailing { db.note("macro invocations at the end of a block are treated as expressions"); - db.note(&format!("to ignore the value produced by the macro, add a semicolon after the invocation of `{name}`")); + db.note(format!("to ignore the value produced by the macro, add a semicolon after the invocation of `{name}`")); } } BuiltinLintDiagnostics::BreakWithLabelAndLoop(span) => { @@ -765,25 +766,55 @@ pub trait LintContext: Sized { ); } BuiltinLintDiagnostics::NamedAsmLabel(help) => { - db.help(&help); + db.help(help); db.note("see the asm section of Rust By Example <https://doc.rust-lang.org/nightly/rust-by-example/unsafe/asm.html#labels> for more information"); }, - BuiltinLintDiagnostics::UnexpectedCfg((name, name_span), None) => { - let Some(names_valid) = &sess.parse_sess.check_config.names_valid else { - bug!("it shouldn't be possible to have a diagnostic on a name if name checking is not enabled"); - }; - let possibilities: Vec<Symbol> = names_valid.iter().map(|s| *s).collect(); + BuiltinLintDiagnostics::UnexpectedCfgName((name, name_span), value) => { + let possibilities: Vec<Symbol> = sess.parse_sess.check_config.expecteds.keys().map(|s| *s).collect(); // Suggest the most probable if we found one if let Some(best_match) = find_best_match_for_name(&possibilities, name, None) { - db.span_suggestion(name_span, "did you mean", best_match, Applicability::MaybeIncorrect); + if let Some(ExpectedValues::Some(best_match_values)) = + sess.parse_sess.check_config.expecteds.get(&best_match) { + let mut possibilities = best_match_values.iter() + .flatten() + .map(Symbol::as_str) + .collect::<Vec<_>>(); + possibilities.sort(); + + if let Some((value, value_span)) = value { + if best_match_values.contains(&Some(value)) { + db.span_suggestion(name_span, "there is a config with a similar name and value", best_match, Applicability::MaybeIncorrect); + } else if best_match_values.contains(&None) { + db.span_suggestion(name_span.to(value_span), "there is a config with a similar name and no value", best_match, Applicability::MaybeIncorrect); + } else if let Some(first_value) = possibilities.first() { + db.span_suggestion(name_span.to(value_span), "there is a config with a similar name and different values", format!("{best_match} = \"{first_value}\""), Applicability::MaybeIncorrect); + } else { + db.span_suggestion(name_span.to(value_span), "there is a config with a similar name and different values", best_match, Applicability::MaybeIncorrect); + }; + } else { + db.span_suggestion(name_span, "there is a config with a similar name", best_match, Applicability::MaybeIncorrect); + } + + if !possibilities.is_empty() { + let possibilities = possibilities.join("`, `"); + db.help(format!("expected values for `{best_match}` are: `{possibilities}`")); + } + } else { + db.span_suggestion(name_span, "there is a config with a similar name", best_match, Applicability::MaybeIncorrect); + } } }, - BuiltinLintDiagnostics::UnexpectedCfg((name, name_span), Some((value, value_span))) => { - let Some(values) = &sess.parse_sess.check_config.values_valid.get(&name) else { + BuiltinLintDiagnostics::UnexpectedCfgValue((name, name_span), value) => { + let Some(ExpectedValues::Some(values)) = &sess.parse_sess.check_config.expecteds.get(&name) else { bug!("it shouldn't be possible to have a diagnostic on a value whose name is not in values"); }; - let possibilities: Vec<Symbol> = values.iter().map(|&s| s).collect(); + let mut have_none_possibility = false; + let possibilities: Vec<Symbol> = values.iter() + .inspect(|a| have_none_possibility |= a.is_none()) + .copied() + .flatten() + .collect(); // Show the full list if all possible values for a given name, but don't do it // for names as the possibilities could be very long @@ -792,17 +823,24 @@ pub trait LintContext: Sized { let mut possibilities = possibilities.iter().map(Symbol::as_str).collect::<Vec<_>>(); possibilities.sort(); - let possibilities = possibilities.join(", "); - db.note(&format!("expected values for `{name}` are: {possibilities}")); + let possibilities = possibilities.join("`, `"); + let none = if have_none_possibility { "(none), " } else { "" }; + + db.note(format!("expected values for `{name}` are: {none}`{possibilities}`")); } - // Suggest the most probable if we found one - if let Some(best_match) = find_best_match_for_name(&possibilities, value, None) { - db.span_suggestion(value_span, "did you mean", format!("\"{best_match}\""), Applicability::MaybeIncorrect); + if let Some((value, value_span)) = value { + // Suggest the most probable if we found one + if let Some(best_match) = find_best_match_for_name(&possibilities, value, None) { + db.span_suggestion(value_span, "there is a expected value with a similar name", format!("\"{best_match}\""), Applicability::MaybeIncorrect); + + } + } else if let &[first_possibility] = &possibilities[..] { + db.span_suggestion(name_span.shrink_to_hi(), "specify a config value", format!(" = \"{first_possibility}\""), Applicability::MaybeIncorrect); } - } else { - db.note(&format!("no expected value for `{name}`")); - if name != sym::feature { + } else if have_none_possibility { + db.note(format!("no expected value for `{name}`")); + if let Some((_value, value_span)) = value { db.span_suggestion(name_span.shrink_to_hi().to(value_span), "remove the value", "", Applicability::MaybeIncorrect); } } diff --git a/compiler/rustc_lint/src/drop_forget_useless.rs b/compiler/rustc_lint/src/drop_forget_useless.rs new file mode 100644 index 000000000..77e4a7669 --- /dev/null +++ b/compiler/rustc_lint/src/drop_forget_useless.rs @@ -0,0 +1,164 @@ +use rustc_hir::{Arm, Expr, ExprKind, Node}; +use rustc_span::sym; + +use crate::{ + lints::{DropCopyDiag, DropRefDiag, ForgetCopyDiag, ForgetRefDiag}, + LateContext, LateLintPass, LintContext, +}; + +declare_lint! { + /// The `dropping_references` lint checks for calls to `std::mem::drop` with a reference + /// instead of an owned value. + /// + /// ### Example + /// + /// ```rust + /// # fn operation_that_requires_mutex_to_be_unlocked() {} // just to make it compile + /// # let mutex = std::sync::Mutex::new(1); // just to make it compile + /// let mut lock_guard = mutex.lock(); + /// std::mem::drop(&lock_guard); // Should have been drop(lock_guard), mutex + /// // still locked + /// operation_that_requires_mutex_to_be_unlocked(); + /// ``` + /// + /// {{produces}} + /// + /// ### Explanation + /// + /// Calling `drop` on a reference will only drop the + /// reference itself, which is a no-op. It will not call the `drop` method (from + /// the `Drop` trait implementation) on the underlying referenced value, which + /// is likely what was intended. + pub DROPPING_REFERENCES, + Warn, + "calls to `std::mem::drop` with a reference instead of an owned value" +} + +declare_lint! { + /// The `forgetting_references` lint checks for calls to `std::mem::forget` with a reference + /// instead of an owned value. + /// + /// ### Example + /// + /// ```rust + /// let x = Box::new(1); + /// std::mem::forget(&x); // Should have been forget(x), x will still be dropped + /// ``` + /// + /// {{produces}} + /// + /// ### Explanation + /// + /// Calling `forget` on a reference will only forget the + /// reference itself, which is a no-op. It will not forget the underlying + /// referenced value, which is likely what was intended. + pub FORGETTING_REFERENCES, + Warn, + "calls to `std::mem::forget` with a reference instead of an owned value" +} + +declare_lint! { + /// The `dropping_copy_types` lint checks for calls to `std::mem::drop` with a value + /// that derives the Copy trait. + /// + /// ### Example + /// + /// ```rust + /// let x: i32 = 42; // i32 implements Copy + /// std::mem::drop(x); // A copy of x is passed to the function, leaving the + /// // original unaffected + /// ``` + /// + /// {{produces}} + /// + /// ### Explanation + /// + /// Calling `std::mem::drop` [does nothing for types that + /// implement Copy](https://doc.rust-lang.org/std/mem/fn.drop.html), since the + /// value will be copied and moved into the function on invocation. + pub DROPPING_COPY_TYPES, + Warn, + "calls to `std::mem::drop` with a value that implements Copy" +} + +declare_lint! { + /// The `forgetting_copy_types` lint checks for calls to `std::mem::forget` with a value + /// that derives the Copy trait. + /// + /// ### Example + /// + /// ```rust + /// let x: i32 = 42; // i32 implements Copy + /// std::mem::forget(x); // A copy of x is passed to the function, leaving the + /// // original unaffected + /// ``` + /// + /// {{produces}} + /// + /// ### Explanation + /// + /// Calling `std::mem::forget` [does nothing for types that + /// implement Copy](https://doc.rust-lang.org/std/mem/fn.drop.html) since the + /// value will be copied and moved into the function on invocation. + /// + /// An alternative, but also valid, explanation is that Copy types do not + /// implement the Drop trait, which means they have no destructors. Without a + /// destructor, there is nothing for `std::mem::forget` to ignore. + pub FORGETTING_COPY_TYPES, + Warn, + "calls to `std::mem::forget` with a value that implements Copy" +} + +declare_lint_pass!(DropForgetUseless => [DROPPING_REFERENCES, FORGETTING_REFERENCES, DROPPING_COPY_TYPES, FORGETTING_COPY_TYPES]); + +impl<'tcx> LateLintPass<'tcx> for DropForgetUseless { + fn check_expr(&mut self, cx: &LateContext<'tcx>, expr: &'tcx Expr<'tcx>) { + if let ExprKind::Call(path, [arg]) = expr.kind + && let ExprKind::Path(ref qpath) = path.kind + && let Some(def_id) = cx.qpath_res(qpath, path.hir_id).opt_def_id() + && let Some(fn_name) = cx.tcx.get_diagnostic_name(def_id) + { + let arg_ty = cx.typeck_results().expr_ty(arg); + let is_copy = arg_ty.is_copy_modulo_regions(cx.tcx, cx.param_env); + let drop_is_single_call_in_arm = is_single_call_in_arm(cx, arg, expr); + match fn_name { + sym::mem_drop if arg_ty.is_ref() && !drop_is_single_call_in_arm => { + cx.emit_spanned_lint(DROPPING_REFERENCES, expr.span, DropRefDiag { arg_ty, label: arg.span }); + }, + sym::mem_forget if arg_ty.is_ref() => { + cx.emit_spanned_lint(FORGETTING_REFERENCES, expr.span, ForgetRefDiag { arg_ty, label: arg.span }); + }, + sym::mem_drop if is_copy && !drop_is_single_call_in_arm => { + cx.emit_spanned_lint(DROPPING_COPY_TYPES, expr.span, DropCopyDiag { arg_ty, label: arg.span }); + } + sym::mem_forget if is_copy => { + cx.emit_spanned_lint(FORGETTING_COPY_TYPES, expr.span, ForgetCopyDiag { arg_ty, label: arg.span }); + } + _ => return, + }; + } + } +} + +// Dropping returned value of a function, as in the following snippet is considered idiomatic, see +// rust-lang/rust-clippy#9482 for examples. +// +// ``` +// match <var> { +// <pat> => drop(fn_with_side_effect_and_returning_some_value()), +// .. +// } +// ``` +fn is_single_call_in_arm<'tcx>( + cx: &LateContext<'tcx>, + arg: &'tcx Expr<'_>, + drop_expr: &'tcx Expr<'_>, +) -> bool { + if arg.can_have_side_effects() { + let parent_node = cx.tcx.hir().find_parent(drop_expr.hir_id); + if let Some(Node::Arm(Arm { body, .. })) = &parent_node { + return body.hir_id == drop_expr.hir_id; + } + } + false +} diff --git a/compiler/rustc_lint/src/early.rs b/compiler/rustc_lint/src/early.rs index 65607d718..9f1f5a26e 100644 --- a/compiler/rustc_lint/src/early.rs +++ b/compiler/rustc_lint/src/early.rs @@ -428,7 +428,7 @@ pub fn check_ast_node_inner<'a, T: EarlyLintPass>( for early_lint in lints { sess.delay_span_bug( early_lint.span, - &format!( + format!( "failed to process buffered lint here (dummy = {})", id == ast::DUMMY_NODE_ID ), diff --git a/compiler/rustc_lint/src/enum_intrinsics_non_enums.rs b/compiler/rustc_lint/src/enum_intrinsics_non_enums.rs index f1ba192f2..2ce28f3a0 100644 --- a/compiler/rustc_lint/src/enum_intrinsics_non_enums.rs +++ b/compiler/rustc_lint/src/enum_intrinsics_non_enums.rs @@ -42,7 +42,7 @@ declare_lint_pass!(EnumIntrinsicsNonEnums => [ENUM_INTRINSICS_NON_ENUMS]); /// Returns `true` if we know for sure that the given type is not an enum. Note that for cases where /// the type is generic, we can't be certain if it will be an enum so we have to assume that it is. fn is_non_enum(t: Ty<'_>) -> bool { - !t.is_enum() && !t.needs_subst() + !t.is_enum() && !t.has_param() } fn enforce_mem_discriminant( diff --git a/compiler/rustc_lint/src/errors.rs b/compiler/rustc_lint/src/errors.rs index 9af5284df..bbae3d368 100644 --- a/compiler/rustc_lint/src/errors.rs +++ b/compiler/rustc_lint/src/errors.rs @@ -81,7 +81,7 @@ pub struct UnknownToolInScopedLint { #[derive(Diagnostic)] #[diag(lint_builtin_ellipsis_inclusive_range_patterns, code = "E0783")] -pub struct BuiltinEllpisisInclusiveRangePatterns { +pub struct BuiltinEllipsisInclusiveRangePatterns { #[primary_span] pub span: Span, #[suggestion(style = "short", code = "{replace}", applicability = "machine-applicable")] diff --git a/compiler/rustc_lint/src/expect.rs b/compiler/rustc_lint/src/expect.rs index e9eb14ea1..b1266b58a 100644 --- a/compiler/rustc_lint/src/expect.rs +++ b/compiler/rustc_lint/src/expect.rs @@ -1,5 +1,5 @@ use crate::lints::{Expectation, ExpectationNote}; -use rustc_middle::ty::query::Providers; +use rustc_middle::query::Providers; use rustc_middle::ty::TyCtxt; use rustc_session::lint::builtin::UNFULFILLED_LINT_EXPECTATIONS; use rustc_session::lint::LintExpectationId; diff --git a/compiler/rustc_lint/src/internal.rs b/compiler/rustc_lint/src/internal.rs index 4ac589c2e..6f773e04a 100644 --- a/compiler/rustc_lint/src/internal.rs +++ b/compiler/rustc_lint/src/internal.rs @@ -4,6 +4,7 @@ use crate::lints::{ BadOptAccessDiag, DefaultHashTypesDiag, DiagOutOfImpl, LintPassByHand, NonExistentDocKeyword, QueryInstability, TyQualified, TykindDiag, TykindKind, UntranslatableDiag, + UntranslatableDiagnosticTrivial, }; use crate::{EarlyContext, EarlyLintPass, LateContext, LateLintPass, LintContext}; use rustc_ast as ast; @@ -366,7 +367,15 @@ declare_tool_lint! { report_in_external_macro: true } -declare_lint_pass!(Diagnostics => [ UNTRANSLATABLE_DIAGNOSTIC, DIAGNOSTIC_OUTSIDE_OF_IMPL ]); +declare_tool_lint! { + /// The `untranslatable_diagnostic_trivial` lint detects diagnostics created using only static strings. + pub rustc::UNTRANSLATABLE_DIAGNOSTIC_TRIVIAL, + Deny, + "prevent creation of diagnostics which cannot be translated, which use only static strings", + report_in_external_macro: true +} + +declare_lint_pass!(Diagnostics => [ UNTRANSLATABLE_DIAGNOSTIC, DIAGNOSTIC_OUTSIDE_OF_IMPL, UNTRANSLATABLE_DIAGNOSTIC_TRIVIAL ]); impl LateLintPass<'_> for Diagnostics { fn check_expr(&mut self, cx: &LateContext<'_>, expr: &Expr<'_>) { @@ -374,9 +383,8 @@ impl LateLintPass<'_> for Diagnostics { debug!(?span, ?def_id, ?substs); let has_attr = ty::Instance::resolve(cx.tcx, cx.param_env, def_id, substs) .ok() - .and_then(|inst| inst) - .map(|inst| cx.tcx.has_attr(inst.def_id(), sym::rustc_lint_diagnostics)) - .unwrap_or(false); + .flatten() + .is_some_and(|inst| cx.tcx.has_attr(inst.def_id(), sym::rustc_lint_diagnostics)); if !has_attr { return; } @@ -423,6 +431,77 @@ impl LateLintPass<'_> for Diagnostics { } } +impl EarlyLintPass for Diagnostics { + #[allow(unused_must_use)] + fn check_stmt(&mut self, cx: &EarlyContext<'_>, stmt: &ast::Stmt) { + // Looking for a straight chain of method calls from 'struct_span_err' to 'emit'. + let ast::StmtKind::Semi(expr) = &stmt.kind else { + return; + }; + let ast::ExprKind::MethodCall(meth) = &expr.kind else { + return; + }; + if meth.seg.ident.name != sym::emit || !meth.args.is_empty() { + return; + } + let mut segments = vec![]; + let mut cur = &meth.receiver; + let fake = &[].into(); + loop { + match &cur.kind { + ast::ExprKind::Call(func, args) => { + if let ast::ExprKind::Path(_, path) = &func.kind { + segments.push((path.segments.last().unwrap().ident.name, args)) + } + break; + } + ast::ExprKind::MethodCall(method) => { + segments.push((method.seg.ident.name, &method.args)); + cur = &method.receiver; + } + ast::ExprKind::MacCall(mac) => { + segments.push((mac.path.segments.last().unwrap().ident.name, fake)); + break; + } + _ => { + break; + } + } + } + segments.reverse(); + if segments.is_empty() { + return; + } + if segments[0].0.as_str() != "struct_span_err" { + return; + } + if !segments.iter().all(|(name, args)| { + let arg = match name.as_str() { + "struct_span_err" | "span_note" | "span_label" | "span_help" if args.len() == 2 => { + &args[1] + } + "note" | "help" if args.len() == 1 => &args[0], + _ => { + return false; + } + }; + if let ast::ExprKind::Lit(lit) = arg.kind + && let ast::token::LitKind::Str = lit.kind { + true + } else { + false + } + }) { + return; + } + cx.emit_spanned_lint( + UNTRANSLATABLE_DIAGNOSTIC_TRIVIAL, + stmt.span, + UntranslatableDiagnosticTrivial, + ); + } +} + declare_tool_lint! { /// The `bad_opt_access` lint detects accessing options by field instead of /// the wrapper function. diff --git a/compiler/rustc_lint/src/late.rs b/compiler/rustc_lint/src/late.rs index b42878a02..8a4a451f8 100644 --- a/compiler/rustc_lint/src/late.rs +++ b/compiler/rustc_lint/src/late.rs @@ -16,7 +16,7 @@ use crate::{passes::LateLintPassObject, LateContext, LateLintPass, LintStore}; use rustc_ast as ast; -use rustc_data_structures::sync::join; +use rustc_data_structures::sync::{join, DynSend}; use rustc_hir as hir; use rustc_hir::def_id::LocalDefId; use rustc_hir::intravisit as hir_visit; @@ -240,8 +240,10 @@ impl<'tcx, T: LateLintPass<'tcx>> hir_visit::Visitor<'tcx> for LateContextAndPas } fn visit_arm(&mut self, a: &'tcx hir::Arm<'tcx>) { - lint_callback!(self, check_arm, a); - hir_visit::walk_arm(self, a); + self.with_lint_attrs(a.hir_id, |cx| { + lint_callback!(cx, check_arm, a); + hir_visit::walk_arm(cx, a); + }) } fn visit_generic_param(&mut self, p: &'tcx hir::GenericParam<'tcx>) { @@ -429,7 +431,7 @@ fn late_lint_crate_inner<'tcx, T: LateLintPass<'tcx>>( /// Performs lint checking on a crate. pub fn check_crate<'tcx, T: LateLintPass<'tcx> + 'tcx>( tcx: TyCtxt<'tcx>, - builtin_lints: impl FnOnce() -> T + Send, + builtin_lints: impl FnOnce() -> T + Send + DynSend, ) { join( || { diff --git a/compiler/rustc_lint/src/levels.rs b/compiler/rustc_lint/src/levels.rs index bb863f095..8376835f5 100644 --- a/compiler/rustc_lint/src/levels.rs +++ b/compiler/rustc_lint/src/levels.rs @@ -14,13 +14,13 @@ use rustc_errors::{DecorateLint, DiagnosticBuilder, DiagnosticMessage, MultiSpan use rustc_hir as hir; use rustc_hir::intravisit::{self, Visitor}; use rustc_hir::HirId; -use rustc_index::vec::IndexVec; +use rustc_index::IndexVec; use rustc_middle::hir::nested_filter; use rustc_middle::lint::{ reveal_actual_level, struct_lint_level, LevelAndSource, LintExpectation, LintLevelSource, ShallowLintLevelMap, }; -use rustc_middle::ty::query::Providers; +use rustc_middle::query::Providers; use rustc_middle::ty::{RegisteredTools, TyCtxt}; use rustc_session::lint::builtin::{RENAMED_AND_REMOVED_LINTS, UNKNOWN_LINTS, UNUSED_ATTRIBUTES}; use rustc_session::lint::{ @@ -242,7 +242,9 @@ impl LintLevelsProvider for LintLevelQueryMap<'_> { struct QueryMapExpectationsWrapper<'tcx> { tcx: TyCtxt<'tcx>, + /// HirId of the currently investigated element. cur: HirId, + /// Level map for `cur`. specs: ShallowLintLevelMap, expectations: Vec<(LintExpectationId, LintExpectation)>, unstable_to_stable_ids: FxHashMap<LintExpectationId, LintExpectationId>, @@ -255,11 +257,11 @@ impl LintLevelsProvider for QueryMapExpectationsWrapper<'_> { self.specs.specs.get(&self.cur.local_id).unwrap_or(&self.empty) } fn insert(&mut self, id: LintId, lvl: LevelAndSource) { - let specs = self.specs.specs.get_mut_or_insert_default(self.cur.local_id); - specs.clear(); - specs.insert(id, lvl); + self.specs.specs.get_mut_or_insert_default(self.cur.local_id).insert(id, lvl); } fn get_lint_level(&self, lint: &'static Lint, _: &Session) -> LevelAndSource { + // We cannot use `tcx.lint_level_at_node` because we want to know in which order the + // attributes have been inserted, in particular whether an `expect` follows a `forbid`. self.specs.lint_level_id_at_node(self.tcx, LintId::of(lint), self.cur) } fn push_expectation(&mut self, id: LintExpectationId, expectation: LintExpectation) { @@ -355,7 +357,9 @@ impl<'tcx> Visitor<'tcx> for LintLevelsBuilder<'_, LintLevelQueryMap<'tcx>> { impl<'tcx> LintLevelsBuilder<'_, QueryMapExpectationsWrapper<'tcx>> { fn add_id(&mut self, hir_id: HirId) { + // Change both the `HirId` and the associated specs. self.provider.cur = hir_id; + self.provider.specs.specs.clear(); self.add(self.provider.tcx.hir().attrs(hir_id), hir_id == hir::CRATE_HIR_ID, Some(hir_id)); } } diff --git a/compiler/rustc_lint/src/lib.rs b/compiler/rustc_lint/src/lib.rs index b35785405..dfddfe09a 100644 --- a/compiler/rustc_lint/src/lib.rs +++ b/compiler/rustc_lint/src/lib.rs @@ -52,6 +52,7 @@ mod array_into_iter; pub mod builtin; mod context; mod deref_into_dyn_supertrait; +mod drop_forget_useless; mod early; mod enum_intrinsics_non_enums; mod errors; @@ -82,10 +83,10 @@ pub use array_into_iter::ARRAY_INTO_ITER; use rustc_ast as ast; use rustc_errors::{DiagnosticMessage, SubdiagnosticMessage}; +use rustc_fluent_macro::fluent_messages; use rustc_hir as hir; use rustc_hir::def_id::LocalDefId; -use rustc_macros::fluent_messages; -use rustc_middle::ty::query::Providers; +use rustc_middle::query::Providers; use rustc_middle::ty::TyCtxt; use rustc_session::lint::builtin::{ BARE_TRAIT_OBJECTS, ELIDED_LIFETIMES_IN_PATHS, EXPLICIT_OUTLIVES_REQUIREMENTS, @@ -96,6 +97,7 @@ use rustc_span::Span; use array_into_iter::ArrayIntoIter; use builtin::*; use deref_into_dyn_supertrait::*; +use drop_forget_useless::*; use enum_intrinsics_non_enums::EnumIntrinsicsNonEnums; use for_loops_over_fallibles::*; use hidden_unicode_codepoints::*; @@ -201,6 +203,7 @@ late_lint_methods!( [ ForLoopsOverFallibles: ForLoopsOverFallibles, DerefIntoDynSupertrait: DerefIntoDynSupertrait, + DropForgetUseless: DropForgetUseless, HardwiredLints: HardwiredLints, ImproperCTypesDeclarations: ImproperCTypesDeclarations, ImproperCTypesDefinitions: ImproperCTypesDefinitions, @@ -518,6 +521,7 @@ fn register_internals(store: &mut LintStore) { store.register_lints(&TyTyKind::get_lints()); store.register_late_pass(|_| Box::new(TyTyKind)); store.register_lints(&Diagnostics::get_lints()); + store.register_early_pass(|| Box::new(Diagnostics)); store.register_late_pass(|_| Box::new(Diagnostics)); store.register_lints(&BadOptAccess::get_lints()); store.register_late_pass(|_| Box::new(BadOptAccess)); diff --git a/compiler/rustc_lint/src/lints.rs b/compiler/rustc_lint/src/lints.rs index 1d5e02369..d96723a68 100644 --- a/compiler/rustc_lint/src/lints.rs +++ b/compiler/rustc_lint/src/lints.rs @@ -662,6 +662,43 @@ pub struct ForLoopsOverFalliblesSuggestion<'a> { pub end_span: Span, } +// drop_forget_useless.rs +#[derive(LintDiagnostic)] +#[diag(lint_dropping_references)] +#[note] +pub struct DropRefDiag<'a> { + pub arg_ty: Ty<'a>, + #[label] + pub label: Span, +} + +#[derive(LintDiagnostic)] +#[diag(lint_dropping_copy_types)] +#[note] +pub struct DropCopyDiag<'a> { + pub arg_ty: Ty<'a>, + #[label] + pub label: Span, +} + +#[derive(LintDiagnostic)] +#[diag(lint_forgetting_references)] +#[note] +pub struct ForgetRefDiag<'a> { + pub arg_ty: Ty<'a>, + #[label] + pub label: Span, +} + +#[derive(LintDiagnostic)] +#[diag(lint_forgetting_copy_types)] +#[note] +pub struct ForgetCopyDiag<'a> { + pub arg_ty: Ty<'a>, + #[label] + pub label: Span, +} + // hidden_unicode_codepoints.rs #[derive(LintDiagnostic)] #[diag(lint_hidden_unicode_codepoints)] @@ -821,6 +858,10 @@ pub struct DiagOutOfImpl; pub struct UntranslatableDiag; #[derive(LintDiagnostic)] +#[diag(lint_trivial_untranslatable_diag)] +pub struct UntranslatableDiagnosticTrivial; + +#[derive(LintDiagnostic)] #[diag(lint_bad_opt_access)] pub struct BadOptAccessDiag<'a> { pub msg: &'a str, @@ -1146,6 +1187,18 @@ pub struct NoopMethodCallDiag<'a> { pub label: Span, } +#[derive(LintDiagnostic)] +#[diag(lint_suspicious_double_ref_deref)] +pub struct SuspiciousDoubleRefDerefDiag<'a> { + pub ty: Ty<'a>, +} + +#[derive(LintDiagnostic)] +#[diag(lint_suspicious_double_ref_clone)] +pub struct SuspiciousDoubleRefCloneDiag<'a> { + pub ty: Ty<'a>, +} + // pass_by_value.rs #[derive(LintDiagnostic)] #[diag(lint_pass_by_value)] diff --git a/compiler/rustc_lint/src/non_fmt_panic.rs b/compiler/rustc_lint/src/non_fmt_panic.rs index 5bb1abfd2..b218cc578 100644 --- a/compiler/rustc_lint/src/non_fmt_panic.rs +++ b/compiler/rustc_lint/src/non_fmt_panic.rs @@ -128,7 +128,7 @@ fn check_panic<'tcx>(cx: &LateContext<'tcx>, f: &'tcx hir::Expr<'tcx>, arg: &'tc // No clue where this argument is coming from. return lint; } - if arg_macro.map_or(false, |id| cx.tcx.is_diagnostic_item(sym::format_macro, id)) { + if arg_macro.is_some_and(|id| cx.tcx.is_diagnostic_item(sym::format_macro, id)) { // A case of `panic!(format!(..))`. lint.note(fluent::lint_supports_fmt_note); if let Some((open, close, _)) = find_delimiters(cx, arg_span) { diff --git a/compiler/rustc_lint/src/nonstandard_style.rs b/compiler/rustc_lint/src/nonstandard_style.rs index 9efc14849..79253cbc8 100644 --- a/compiler/rustc_lint/src/nonstandard_style.rs +++ b/compiler/rustc_lint/src/nonstandard_style.rs @@ -33,6 +33,11 @@ pub fn method_context(cx: &LateContext<'_>, id: LocalDefId) -> MethodLateContext } } +fn assoc_item_in_trait_impl(cx: &LateContext<'_>, ii: &hir::ImplItem<'_>) -> bool { + let item = cx.tcx.associated_item(ii.owner_id); + item.trait_item_def_id.is_some() +} + declare_lint! { /// The `non_camel_case_types` lint detects types, variants, traits and /// type parameters that don't have camel case names. @@ -177,6 +182,7 @@ impl EarlyLintPass for NonCamelCaseTypes { // trait impls where we should have warned for the trait definition already. ast::ItemKind::Impl(box ast::Impl { of_trait: None, items, .. }) => { for it in items { + // FIXME: this doesn't respect `#[allow(..)]` on the item itself. if let ast::AssocItemKind::Type(..) = it.kind { self.check_case(cx, "associated type", &it.ident); } @@ -505,7 +511,7 @@ impl<'tcx> LateLintPass<'tcx> for NonUpperCaseGlobals { } fn check_impl_item(&mut self, cx: &LateContext<'_>, ii: &hir::ImplItem<'_>) { - if let hir::ImplItemKind::Const(..) = ii.kind { + if let hir::ImplItemKind::Const(..) = ii.kind && !assoc_item_in_trait_impl(cx, ii) { NonUpperCaseGlobals::check_upper_case(cx, "associated constant", &ii.ident); } } diff --git a/compiler/rustc_lint/src/noop_method_call.rs b/compiler/rustc_lint/src/noop_method_call.rs index d67a00619..d56c35bb6 100644 --- a/compiler/rustc_lint/src/noop_method_call.rs +++ b/compiler/rustc_lint/src/noop_method_call.rs @@ -1,10 +1,13 @@ use crate::context::LintContext; -use crate::lints::NoopMethodCallDiag; +use crate::lints::{ + NoopMethodCallDiag, SuspiciousDoubleRefCloneDiag, SuspiciousDoubleRefDerefDiag, +}; use crate::LateContext; use crate::LateLintPass; use rustc_hir::def::DefKind; use rustc_hir::{Expr, ExprKind}; use rustc_middle::ty; +use rustc_middle::ty::adjustment::Adjust; use rustc_span::symbol::sym; declare_lint! { @@ -35,32 +38,62 @@ declare_lint! { "detects the use of well-known noop methods" } -declare_lint_pass!(NoopMethodCall => [NOOP_METHOD_CALL]); +declare_lint! { + /// The `suspicious_double_ref_op` lint checks for usage of `.clone()`/`.borrow()`/`.deref()` + /// on an `&&T` when `T: !Deref/Borrow/Clone`, which means the call will return the inner `&T`, + /// instead of performing the operation on the underlying `T` and can be confusing. + /// + /// ### Example + /// + /// ```rust + /// # #![allow(unused)] + /// struct Foo; + /// let foo = &&Foo; + /// let clone: &Foo = foo.clone(); + /// ``` + /// + /// {{produces}} + /// + /// ### Explanation + /// + /// Since `Foo` doesn't implement `Clone`, running `.clone()` only dereferences the double + /// reference, instead of cloning the inner type which should be what was intended. + pub SUSPICIOUS_DOUBLE_REF_OP, + Warn, + "suspicious call of trait method on `&&T`" +} + +declare_lint_pass!(NoopMethodCall => [NOOP_METHOD_CALL, SUSPICIOUS_DOUBLE_REF_OP]); impl<'tcx> LateLintPass<'tcx> for NoopMethodCall { fn check_expr(&mut self, cx: &LateContext<'tcx>, expr: &'tcx Expr<'_>) { // We only care about method calls. - let ExprKind::MethodCall(call, receiver, ..) = &expr.kind else { - return + let ExprKind::MethodCall(call, receiver, _, call_span) = &expr.kind else { + return; }; + + if call_span.from_expansion() { + return; + } + // We only care about method calls corresponding to the `Clone`, `Deref` and `Borrow` // traits and ignore any other method call. - let did = match cx.typeck_results().type_dependent_def(expr.hir_id) { - // Verify we are dealing with a method/associated function. - Some((DefKind::AssocFn, did)) => match cx.tcx.trait_of_item(did) { - // Check that we're dealing with a trait method for one of the traits we care about. - Some(trait_id) - if matches!( - cx.tcx.get_diagnostic_name(trait_id), - Some(sym::Borrow | sym::Clone | sym::Deref) - ) => - { - did - } - _ => return, - }, - _ => return, + + let Some((DefKind::AssocFn, did)) = + cx.typeck_results().type_dependent_def(expr.hir_id) + else { + return; }; + + let Some(trait_id) = cx.tcx.trait_of_item(did) else { return }; + + if !matches!( + cx.tcx.get_diagnostic_name(trait_id), + Some(sym::Borrow | sym::Clone | sym::Deref) + ) { + return; + }; + let substs = cx .tcx .normalize_erasing_regions(cx.param_env, cx.typeck_results().node_substs(expr.hir_id)); @@ -70,25 +103,43 @@ impl<'tcx> LateLintPass<'tcx> for NoopMethodCall { }; // (Re)check that it implements the noop diagnostic. let Some(name) = cx.tcx.get_diagnostic_name(i.def_id()) else { return }; - if !matches!( - name, - sym::noop_method_borrow | sym::noop_method_clone | sym::noop_method_deref - ) { - return; - } + let receiver_ty = cx.typeck_results().expr_ty(receiver); let expr_ty = cx.typeck_results().expr_ty_adjusted(expr); - if receiver_ty != expr_ty { - // This lint will only trigger if the receiver type and resulting expression \ - // type are the same, implying that the method call is unnecessary. + let arg_adjustments = cx.typeck_results().expr_adjustments(receiver); + + // If there is any user defined auto-deref step, then we don't want to warn. + // https://github.com/rust-lang/rust-clippy/issues/9272 + if arg_adjustments.iter().any(|adj| matches!(adj.kind, Adjust::Deref(Some(_)))) { return; } + let expr_span = expr.span; let span = expr_span.with_lo(receiver.span.hi()); - cx.emit_spanned_lint( - NOOP_METHOD_CALL, - span, - NoopMethodCallDiag { method: call.ident.name, receiver_ty, label: span }, - ); + + if receiver_ty == expr_ty { + cx.emit_spanned_lint( + NOOP_METHOD_CALL, + span, + NoopMethodCallDiag { method: call.ident.name, receiver_ty, label: span }, + ); + } else { + match name { + // If `type_of(x) == T` and `x.borrow()` is used to get `&T`, + // then that should be allowed + sym::noop_method_borrow => return, + sym::noop_method_clone => cx.emit_spanned_lint( + SUSPICIOUS_DOUBLE_REF_OP, + span, + SuspiciousDoubleRefCloneDiag { ty: expr_ty }, + ), + sym::noop_method_deref => cx.emit_spanned_lint( + SUSPICIOUS_DOUBLE_REF_OP, + span, + SuspiciousDoubleRefDerefDiag { ty: expr_ty }, + ), + _ => return, + } + } } } diff --git a/compiler/rustc_lint/src/opaque_hidden_inferred_bound.rs b/compiler/rustc_lint/src/opaque_hidden_inferred_bound.rs index f9d43fe22..15715c8fc 100644 --- a/compiler/rustc_lint/src/opaque_hidden_inferred_bound.rs +++ b/compiler/rustc_lint/src/opaque_hidden_inferred_bound.rs @@ -74,7 +74,7 @@ impl<'tcx> LateLintPass<'tcx> for OpaqueHiddenInferredBound { // For every projection predicate in the opaque type's explicit bounds, // check that the type that we're assigning actually satisfies the bounds // of the associated type. - for &(pred, pred_span) in cx.tcx.explicit_item_bounds(def_id) { + for (pred, pred_span) in cx.tcx.explicit_item_bounds(def_id).subst_identity_iter_copied() { // Liberate bound regions in the predicate since we // don't actually care about lifetimes in this check. let predicate = cx.tcx.liberate_late_bound_regions(def_id, pred.kind()); @@ -112,7 +112,7 @@ impl<'tcx> LateLintPass<'tcx> for OpaqueHiddenInferredBound { // with `impl Send: OtherTrait`. for (assoc_pred, assoc_pred_span) in cx .tcx - .bound_explicit_item_bounds(proj.projection_ty.def_id) + .explicit_item_bounds(proj.projection_ty.def_id) .subst_iter_copied(cx.tcx, &proj.projection_ty.substs) { let assoc_pred = assoc_pred.fold_with(proj_replacer); diff --git a/compiler/rustc_lint/src/types.rs b/compiler/rustc_lint/src/types.rs index a6ba74220..4bf4fda82 100644 --- a/compiler/rustc_lint/src/types.rs +++ b/compiler/rustc_lint/src/types.rs @@ -677,7 +677,7 @@ pub fn transparent_newtype_field<'a, 'tcx>( let param_env = tcx.param_env(variant.def_id); variant.fields.iter().find(|field| { let field_ty = tcx.type_of(field.did).subst_identity(); - let is_zst = tcx.layout_of(param_env.and(field_ty)).map_or(false, |layout| layout.is_zst()); + let is_zst = tcx.layout_of(param_env.and(field_ty)).is_ok_and(|layout| layout.is_zst()); !is_zst }) } @@ -1119,14 +1119,14 @@ impl<'a, 'tcx> ImproperCTypesVisitor<'a, 'tcx> { // `extern "C" fn` functions can have type parameters, which may or may not be FFI-safe, // so they are currently ignored for the purposes of this lint. - ty::Param(..) | ty::Alias(ty::Projection, ..) + ty::Param(..) | ty::Alias(ty::Projection | ty::Inherent, ..) if matches!(self.mode, CItemKind::Definition) => { FfiSafe } ty::Param(..) - | ty::Alias(ty::Projection, ..) + | ty::Alias(ty::Projection | ty::Inherent, ..) | ty::Infer(..) | ty::Bound(..) | ty::Error(_) diff --git a/compiler/rustc_lint/src/unused.rs b/compiler/rustc_lint/src/unused.rs index 28cc63198..8f75fa11d 100644 --- a/compiler/rustc_lint/src/unused.rs +++ b/compiler/rustc_lint/src/unused.rs @@ -256,7 +256,7 @@ impl<'tcx> LateLintPass<'tcx> for UnusedResults { } ty::Adt(def, _) => is_def_must_use(cx, def.did(), span), ty::Alias(ty::Opaque, ty::AliasTy { def_id: def, .. }) => { - elaborate(cx.tcx, cx.tcx.explicit_item_bounds(def).iter().cloned()) + elaborate(cx.tcx, cx.tcx.explicit_item_bounds(def).subst_identity_iter_copied()) // We only care about self bounds for the impl-trait .filter_only_self() .find_map(|(pred, _span)| { @@ -571,36 +571,50 @@ trait UnusedDelimLint { } } - // Prevent false-positives in cases like `fn x() -> u8 { ({ 0 } + 1) }` - let lhs_needs_parens = { + // Check if LHS needs parens to prevent false-positives in cases like `fn x() -> u8 { ({ 0 } + 1) }`. + { let mut innermost = inner; loop { innermost = match &innermost.kind { - ExprKind::Binary(_, lhs, _rhs) => lhs, + ExprKind::Binary(_op, lhs, _rhs) => lhs, ExprKind::Call(fn_, _params) => fn_, ExprKind::Cast(expr, _ty) => expr, ExprKind::Type(expr, _ty) => expr, ExprKind::Index(base, _subscript) => base, - _ => break false, + _ => break, }; if !classify::expr_requires_semi_to_be_stmt(innermost) { - break true; + return true; } } - }; + } - lhs_needs_parens - || (followed_by_block - && match &inner.kind { - ExprKind::Ret(_) - | ExprKind::Break(..) - | ExprKind::Yield(..) - | ExprKind::Yeet(..) => true, - ExprKind::Range(_lhs, Some(rhs), _limits) => { - matches!(rhs.kind, ExprKind::Block(..)) - } - _ => parser::contains_exterior_struct_lit(&inner), - }) + // Check if RHS needs parens to prevent false-positives in cases like `if (() == return) {}`. + if !followed_by_block { + return false; + } + let mut innermost = inner; + loop { + innermost = match &innermost.kind { + ExprKind::Unary(_op, expr) => expr, + ExprKind::Binary(_op, _lhs, rhs) => rhs, + ExprKind::AssignOp(_op, _lhs, rhs) => rhs, + ExprKind::Assign(_lhs, rhs, _span) => rhs, + + ExprKind::Ret(_) | ExprKind::Yield(..) | ExprKind::Yeet(..) => return true, + + ExprKind::Break(_label, None) => return false, + ExprKind::Break(_label, Some(break_expr)) => { + return matches!(break_expr.kind, ExprKind::Block(..)); + } + + ExprKind::Range(_lhs, Some(rhs), _limits) => { + return matches!(rhs.kind, ExprKind::Block(..)); + } + + _ => return parser::contains_exterior_struct_lit(&inner), + } + } } fn emit_unused_delims_expr( @@ -638,26 +652,20 @@ trait UnusedDelimLint { return; } let spans = match value.kind { - ast::ExprKind::Block(ref block, None) if block.stmts.len() == 1 => { - if let Some(span) = block.stmts[0].span.find_ancestor_inside(value.span) { - Some((value.span.with_hi(span.lo()), value.span.with_lo(span.hi()))) - } else { - None - } - } + ast::ExprKind::Block(ref block, None) if block.stmts.len() == 1 => block.stmts[0] + .span + .find_ancestor_inside(value.span) + .map(|span| (value.span.with_hi(span.lo()), value.span.with_lo(span.hi()))), ast::ExprKind::Paren(ref expr) => { - let expr_span = expr.span.find_ancestor_inside(value.span); - if let Some(expr_span) = expr_span { - Some((value.span.with_hi(expr_span.lo()), value.span.with_lo(expr_span.hi()))) - } else { - None - } + expr.span.find_ancestor_inside(value.span).map(|expr_span| { + (value.span.with_hi(expr_span.lo()), value.span.with_lo(expr_span.hi())) + }) } _ => return, }; let keep_space = ( - left_pos.map_or(false, |s| s >= value.span.lo()), - right_pos.map_or(false, |s| s <= value.span.hi()), + left_pos.is_some_and(|s| s >= value.span.lo()), + right_pos.is_some_and(|s| s <= value.span.hi()), ); self.emit_unused_delims(cx, value.span, spans, ctx.into(), keep_space); } @@ -930,11 +938,10 @@ impl UnusedParens { // Otherwise proceed with linting. _ => {} } - let spans = if let Some(inner) = inner.span.find_ancestor_inside(value.span) { - Some((value.span.with_hi(inner.lo()), value.span.with_lo(inner.hi()))) - } else { - None - }; + let spans = inner + .span + .find_ancestor_inside(value.span) + .map(|inner| (value.span.with_hi(inner.lo()), value.span.with_lo(inner.hi()))); self.emit_unused_delims(cx, value.span, spans, "pattern", keep_space); } } @@ -1045,11 +1052,11 @@ impl EarlyLintPass for UnusedParens { if self.with_self_ty_parens && b.generic_params.len() > 0 => {} ast::TyKind::ImplTrait(_, bounds) if bounds.len() > 1 => {} _ => { - let spans = if let Some(r) = r.span.find_ancestor_inside(ty.span) { - Some((ty.span.with_hi(r.lo()), ty.span.with_lo(r.hi()))) - } else { - None - }; + let spans = r + .span + .find_ancestor_inside(ty.span) + .map(|r| (ty.span.with_hi(r.lo()), ty.span.with_lo(r.hi()))); + self.emit_unused_delims(cx, ty.span, spans, "type", (false, false)); } } |