diff options
| author | Ashley Mannix <kodraus@hey.com> | 2021-01-18 21:53:22 +1000 |
|---|---|---|
| committer | GitHub <noreply@github.com> | 2021-01-18 21:53:22 +1000 |
| commit | 9009f8f0319fb0f1a9ef712e6f379c2bfda2d101 (patch) | |
| tree | b491a34a71d1c9f0f6f63236bbd6451e6e955208 /clippy_lints | |
| parent | e47710540560b6a52e9305db5872de07a9e0d8a4 (diff) | |
| parent | 488153ff2ff678051f06a94dc4486632d788c328 (diff) | |
Rollup merge of #81038 - flip1995:clippyup, r=Manishearth
Update Clippy Biweekly Clippy update r? ``@Manishearth``
Diffstat (limited to 'clippy_lints')
53 files changed, 914 insertions, 134 deletions
diff --git a/clippy_lints/src/attrs.rs b/clippy_lints/src/attrs.rs index 7607394b2fe..652d1fa16b6 100644 --- a/clippy_lints/src/attrs.rs +++ b/clippy_lints/src/attrs.rs @@ -370,7 +370,7 @@ fn extract_clippy_lint(lint: &NestedMetaItem) -> Option<SymbolStr> { if let Some(meta_item) = lint.meta_item(); if meta_item.path.segments.len() > 1; if let tool_name = meta_item.path.segments[0].ident; - if tool_name.as_str() == "clippy"; + if tool_name.name == sym::clippy; let lint_name = meta_item.path.segments.last().unwrap().ident.name; then { return Some(lint_name.as_str()); diff --git a/clippy_lints/src/collapsible_if.rs b/clippy_lints/src/collapsible_if.rs index 42bff564de0..93ccc76d0c9 100644 --- a/clippy_lints/src/collapsible_if.rs +++ b/clippy_lints/src/collapsible_if.rs @@ -23,9 +23,7 @@ use rustc_errors::Applicability; declare_clippy_lint! { /// **What it does:** Checks for nested `if` statements which can be collapsed - /// by `&&`-combining their conditions and for `else { if ... }` expressions - /// that - /// can be collapsed to `else if ...`. + /// by `&&`-combining their conditions. /// /// **Why is this bad?** Each `if`-statement adds one level of nesting, which /// makes code look more complex than it really is. @@ -40,7 +38,31 @@ declare_clippy_lint! { /// } /// } /// - /// // or + /// ``` + /// + /// Should be written: + /// + /// ```rust.ignore + /// if x && y { + /// … + /// } + /// ``` + pub COLLAPSIBLE_IF, + style, + "nested `if`s that can be collapsed (e.g., `if x { if y { ... } }`" +} + +declare_clippy_lint! { + /// **What it does:** Checks for collapsible `else { if ... }` expressions + /// that can be collapsed to `else if ...`. + /// + /// **Why is this bad?** Each `if`-statement adds one level of nesting, which + /// makes code look more complex than it really is. + /// + /// **Known problems:** None. + /// + /// **Example:** + /// ```rust,ignore /// /// if x { /// … @@ -54,24 +76,18 @@ declare_clippy_lint! { /// Should be written: /// /// ```rust.ignore - /// if x && y { - /// … - /// } - /// - /// // or - /// /// if x { /// … /// } else if y { /// … /// } /// ``` - pub COLLAPSIBLE_IF, + pub COLLAPSIBLE_ELSE_IF, style, - "`if`s that can be collapsed (e.g., `if x { if y { ... } }` and `else { if x { ... } }`)" + "nested `else`-`if` expressions that can be collapsed (e.g., `else { if x { ... } }`)" } -declare_lint_pass!(CollapsibleIf => [COLLAPSIBLE_IF]); +declare_lint_pass!(CollapsibleIf => [COLLAPSIBLE_IF, COLLAPSIBLE_ELSE_IF]); impl EarlyLintPass for CollapsibleIf { fn check_expr(&mut self, cx: &EarlyContext<'_>, expr: &ast::Expr) { @@ -112,7 +128,7 @@ fn check_collapsible_maybe_if_let(cx: &EarlyContext<'_>, else_: &ast::Expr) { let mut applicability = Applicability::MachineApplicable; span_lint_and_sugg( cx, - COLLAPSIBLE_IF, + COLLAPSIBLE_ELSE_IF, block.span, "this `else { if .. }` block can be collapsed", "collapse nested if block", diff --git a/clippy_lints/src/comparison_chain.rs b/clippy_lints/src/comparison_chain.rs index ae1143b2c50..90d31dece13 100644 --- a/clippy_lints/src/comparison_chain.rs +++ b/clippy_lints/src/comparison_chain.rs @@ -13,7 +13,7 @@ declare_clippy_lint! { /// repetitive /// /// **Known problems:** The match statement may be slower due to the compiler - /// not inlining the call to cmp. See issue #5354 + /// not inlining the call to cmp. See issue [#5354](https://github.com/rust-lang/rust-clippy/issues/5354) /// /// **Example:** /// ```rust,ignore diff --git a/clippy_lints/src/copies.rs b/clippy_lints/src/copies.rs index 6f48ffeb0e9..944aaafb46d 100644 --- a/clippy_lints/src/copies.rs +++ b/clippy_lints/src/copies.rs @@ -112,7 +112,8 @@ impl<'tcx> LateLintPass<'tcx> for CopyAndPaste { if let Some(&Expr { kind: ExprKind::If(_, _, Some(ref else_expr)), .. - }) = get_parent_expr(cx, expr) { + }) = get_parent_expr(cx, expr) + { if else_expr.hir_id == expr.hir_id { return; } diff --git a/clippy_lints/src/copy_iterator.rs b/clippy_lints/src/copy_iterator.rs index a7aa2cb35c1..48899b33899 100644 --- a/clippy_lints/src/copy_iterator.rs +++ b/clippy_lints/src/copy_iterator.rs @@ -1,5 +1,5 @@ use crate::utils::{is_copy, match_path, paths, span_lint_and_note}; -use rustc_hir::{Item, ItemKind, Impl}; +use rustc_hir::{Impl, Item, ItemKind}; use rustc_lint::{LateContext, LateLintPass}; use rustc_session::{declare_lint_pass, declare_tool_lint}; diff --git a/clippy_lints/src/default.rs b/clippy_lints/src/default.rs index b0d7c7b3baa..f7224811e6e 100644 --- a/clippy_lints/src/default.rs +++ b/clippy_lints/src/default.rs @@ -1,4 +1,6 @@ -use crate::utils::{any_parent_is_automatically_derived, contains_name, match_def_path, paths, qpath_res, snippet}; +use crate::utils::{ + any_parent_is_automatically_derived, contains_name, match_def_path, paths, qpath_res, snippet_with_macro_callsite, +}; use crate::utils::{span_lint_and_note, span_lint_and_sugg}; use if_chain::if_chain; use rustc_data_structures::fx::FxHashSet; @@ -6,6 +8,7 @@ use rustc_errors::Applicability; use rustc_hir::def::Res; use rustc_hir::{Block, Expr, ExprKind, PatKind, QPath, Stmt, StmtKind}; use rustc_lint::{LateContext, LateLintPass}; +use rustc_middle::lint::in_external_macro; use rustc_middle::ty; use rustc_session::{declare_tool_lint, impl_lint_pass}; use rustc_span::symbol::{Ident, Symbol}; @@ -118,6 +121,8 @@ impl LateLintPass<'_> for Default { // only take `let ...` statements if let StmtKind::Local(local) = stmt.kind; if let Some(expr) = local.init; + if !any_parent_is_automatically_derived(cx.tcx, expr.hir_id); + if !in_external_macro(cx.tcx.sess, expr.span); // only take bindings to identifiers if let PatKind::Binding(_, binding_id, ident, _) = local.pat.kind; // only when assigning `... = Default::default()` @@ -187,7 +192,7 @@ impl LateLintPass<'_> for Default { .into_iter() .map(|(field, rhs)| { // extract and store the assigned value for help message - let value_snippet = snippet(cx, rhs.span, ".."); + let value_snippet = snippet_with_macro_callsite(cx, rhs.span, ".."); format!("{}: {}", field, value_snippet) }) .collect::<Vec<String>>() diff --git a/clippy_lints/src/derive.rs b/clippy_lints/src/derive.rs index b55f59f021d..b1e363663bb 100644 --- a/clippy_lints/src/derive.rs +++ b/clippy_lints/src/derive.rs @@ -7,7 +7,7 @@ use if_chain::if_chain; use rustc_hir::def_id::DefId; use rustc_hir::intravisit::{walk_expr, walk_fn, walk_item, FnKind, NestedVisitorMap, Visitor}; use rustc_hir::{ - BlockCheckMode, BodyId, Expr, ExprKind, FnDecl, HirId, Item, ItemKind, Impl, TraitRef, UnsafeSource, Unsafety, + BlockCheckMode, BodyId, Expr, ExprKind, FnDecl, HirId, Impl, Item, ItemKind, TraitRef, UnsafeSource, Unsafety, }; use rustc_lint::{LateContext, LateLintPass}; use rustc_middle::hir::map::Map; diff --git a/clippy_lints/src/empty_enum.rs b/clippy_lints/src/empty_enum.rs index a249117d182..853b3afdc3a 100644 --- a/clippy_lints/src/empty_enum.rs +++ b/clippy_lints/src/empty_enum.rs @@ -8,8 +8,12 @@ use rustc_session::{declare_lint_pass, declare_tool_lint}; declare_clippy_lint! { /// **What it does:** Checks for `enum`s with no variants. /// + /// As of this writing, the `never_type` is still a + /// nightly-only experimental API. Therefore, this lint is only triggered + /// if the `never_type` is enabled. + /// /// **Why is this bad?** If you want to introduce a type which - /// can't be instantiated, you should use `!` (the never type), + /// can't be instantiated, you should use `!` (the primitive type "never"), /// or a wrapper around it, because `!` has more extensive /// compiler support (type inference, etc...) and wrappers /// around it are the conventional way to define an uninhabited type. @@ -40,6 +44,11 @@ declare_lint_pass!(EmptyEnum => [EMPTY_ENUM]); impl<'tcx> LateLintPass<'tcx> for EmptyEnum { fn check_item(&mut self, cx: &LateContext<'_>, item: &Item<'_>) { + // Only suggest the `never_type` if the feature is enabled + if !cx.tcx.features().never_type { + return; + } + let did = cx.tcx.hir().local_def_id(item.hir_id); if let ItemKind::Enum(..) = item.kind { let ty = cx.tcx.type_of(did); diff --git a/clippy_lints/src/escape.rs b/clippy_lints/src/escape.rs index 55087697812..40e93da8dff 100644 --- a/clippy_lints/src/escape.rs +++ b/clippy_lints/src/escape.rs @@ -1,15 +1,16 @@ use rustc_hir::intravisit; -use rustc_hir::{self, Body, FnDecl, HirId, HirIdSet, ItemKind, Impl, Node}; +use rustc_hir::{self, AssocItemKind, Body, FnDecl, HirId, HirIdSet, Impl, ItemKind, Node}; use rustc_infer::infer::TyCtxtInferExt; use rustc_lint::{LateContext, LateLintPass}; -use rustc_middle::ty::{self, Ty}; +use rustc_middle::ty::{self, TraitRef, Ty}; use rustc_session::{declare_tool_lint, impl_lint_pass}; use rustc_span::source_map::Span; +use rustc_span::symbol::kw; use rustc_target::abi::LayoutOf; use rustc_target::spec::abi::Abi; use rustc_typeck::expr_use_visitor::{ConsumeMode, Delegate, ExprUseVisitor, PlaceBase, PlaceWithHirId}; -use crate::utils::span_lint; +use crate::utils::{contains_ty, span_lint}; #[derive(Copy, Clone)] pub struct BoxedLocal { @@ -51,6 +52,7 @@ fn is_non_trait_box(ty: Ty<'_>) -> bool { struct EscapeDelegate<'a, 'tcx> { cx: &'a LateContext<'tcx>, set: HirIdSet, + trait_self_ty: Option<Ty<'a>>, too_large_for_stack: u64, } @@ -72,19 +74,34 @@ impl<'tcx> LateLintPass<'tcx> for BoxedLocal { } } - // If the method is an impl for a trait, don't warn. let parent_id = cx.tcx.hir().get_parent_item(hir_id); let parent_node = cx.tcx.hir().find(parent_id); + let mut trait_self_ty = None; if let Some(Node::Item(item)) = parent_node { + // If the method is an impl for a trait, don't warn. if let ItemKind::Impl(Impl { of_trait: Some(_), .. }) = item.kind { return; } + + // find `self` ty for this trait if relevant + if let ItemKind::Trait(_, _, _, _, items) = item.kind { + for trait_item in items { + if trait_item.id.hir_id == hir_id { + // be sure we have `self` parameter in this function + if let AssocItemKind::Fn { has_self: true } = trait_item.kind { + trait_self_ty = + Some(TraitRef::identity(cx.tcx, trait_item.id.hir_id.owner.to_def_id()).self_ty()); + } + } + } + } } let mut v = EscapeDelegate { cx, set: HirIdSet::default(), + trait_self_ty, too_large_for_stack: self.too_large_for_stack, }; @@ -153,10 +170,17 @@ impl<'a, 'tcx> Delegate<'tcx> for EscapeDelegate<'a, 'tcx> { return; } + // skip if there is a `self` parameter binding to a type + // that contains `Self` (i.e.: `self: Box<Self>`), see #4804 + if let Some(trait_self_ty) = self.trait_self_ty { + if map.name(cmt.hir_id) == kw::SelfLower && contains_ty(cmt.place.ty(), trait_self_ty) { + return; + } + } + if is_non_trait_box(cmt.place.ty()) && !self.is_large_box(cmt.place.ty()) { self.set.insert(cmt.hir_id); } - return; } } } diff --git a/clippy_lints/src/eta_reduction.rs b/clippy_lints/src/eta_reduction.rs index 53df3abbf54..1a722d39f73 100644 --- a/clippy_lints/src/eta_reduction.rs +++ b/clippy_lints/src/eta_reduction.rs @@ -22,7 +22,7 @@ declare_clippy_lint! { /// **Known problems:** If creating the closure inside the closure has a side- /// effect then moving the closure creation out will change when that side- /// effect runs. - /// See rust-lang/rust-clippy#1439 for more details. + /// See [#1439](https://github.com/rust-lang/rust-clippy/issues/1439) for more details. /// /// **Example:** /// ```rust,ignore @@ -45,8 +45,9 @@ declare_clippy_lint! { /// /// **Why is this bad?** It's unnecessary to create the closure. /// - /// **Known problems:** rust-lang/rust-clippy#3071, rust-lang/rust-clippy#4002, - /// rust-lang/rust-clippy#3942 + /// **Known problems:** [#3071](https://github.com/rust-lang/rust-clippy/issues/3071), + /// [#3942](https://github.com/rust-lang/rust-clippy/issues/3942), + /// [#4002](https://github.com/rust-lang/rust-clippy/issues/4002) /// /// /// **Example:** diff --git a/clippy_lints/src/from_over_into.rs b/clippy_lints/src/from_over_into.rs index 1e7e5f53cc2..b010abda24d 100644 --- a/clippy_lints/src/from_over_into.rs +++ b/clippy_lints/src/from_over_into.rs @@ -70,7 +70,7 @@ impl LateLintPass<'_> for FromOverInto { span_lint_and_help( cx, FROM_OVER_INTO, - item.span, + cx.tcx.sess.source_map().guess_head_span(item.span), "an implementation of `From` is preferred since it gives you `Into<_>` for free where the reverse isn't true", None, "consider to implement `From` instead", diff --git a/clippy_lints/src/if_let_mutex.rs b/clippy_lints/src/if_let_mutex.rs index 2e55094d90c..58511c6d57c 100644 --- a/clippy_lints/src/if_let_mutex.rs +++ b/clippy_lints/src/if_let_mutex.rs @@ -145,7 +145,7 @@ impl<'tcx, 'l> ArmVisitor<'tcx, 'l> { fn is_mutex_lock_call<'tcx>(cx: &LateContext<'tcx>, expr: &'tcx Expr<'_>) -> Option<&'tcx Expr<'tcx>> { if_chain! { if let ExprKind::MethodCall(path, _span, args, _) = &expr.kind; - if path.ident.to_string() == "lock"; + if path.ident.as_str() == "lock"; let ty = cx.typeck_results().expr_ty(&args[0]); if is_type_diagnostic_item(cx, ty, sym!(mutex_type)); then { diff --git a/clippy_lints/src/inherent_impl.rs b/clippy_lints/src/inherent_impl.rs index e287aecb044..ea26c84cde1 100644 --- a/clippy_lints/src/inherent_impl.rs +++ b/clippy_lints/src/inherent_impl.rs @@ -2,7 +2,7 @@ use crate::utils::{in_macro, span_lint_and_then}; use rustc_data_structures::fx::FxHashMap; -use rustc_hir::{def_id, Crate, Item, ItemKind, Impl}; +use rustc_hir::{def_id, Crate, Impl, Item, ItemKind}; use rustc_lint::{LateContext, LateLintPass}; use rustc_session::{declare_tool_lint, impl_lint_pass}; use rustc_span::Span; diff --git a/clippy_lints/src/len_zero.rs b/clippy_lints/src/len_zero.rs index 5474b30bdec..e95caf6a35f 100644 --- a/clippy_lints/src/len_zero.rs +++ b/clippy_lints/src/len_zero.rs @@ -3,7 +3,7 @@ use rustc_ast::ast::LitKind; use rustc_data_structures::fx::FxHashSet; use rustc_errors::Applicability; use rustc_hir::def_id::DefId; -use rustc_hir::{AssocItemKind, BinOpKind, Expr, ExprKind, ImplItemRef, Item, ItemKind, Impl, TraitItemRef}; +use rustc_hir::{AssocItemKind, BinOpKind, Expr, ExprKind, Impl, ImplItemRef, Item, ItemKind, TraitItemRef}; use rustc_lint::{LateContext, LateLintPass}; use rustc_middle::ty; use rustc_session::{declare_lint_pass, declare_tool_lint}; diff --git a/clippy_lints/src/lib.rs b/clippy_lints/src/lib.rs index aaa17561f06..781282cdfbd 100644 --- a/clippy_lints/src/lib.rs +++ b/clippy_lints/src/lib.rs @@ -271,6 +271,7 @@ mod needless_borrow; mod needless_borrowed_ref; mod needless_continue; mod needless_pass_by_value; +mod needless_question_mark; mod needless_update; mod neg_cmp_op_on_partial_ord; mod neg_multiply; @@ -341,6 +342,7 @@ mod unwrap_in_result; mod use_self; mod useless_conversion; mod vec; +mod vec_init_then_push; mod vec_resize_to_zero; mod verbose_file_reads; mod wildcard_dependencies; @@ -528,6 +530,8 @@ pub fn register_plugins(store: &mut rustc_lint::LintStore, sess: &Session, conf: &utils::internal_lints::OUTER_EXPN_EXPN_DATA, #[cfg(feature = "internal-lints")] &utils::internal_lints::PRODUCE_ICE, + #[cfg(feature = "internal-lints")] + &utils::internal_lints::UNNECESSARY_SYMBOL_STR, &approx_const::APPROX_CONSTANT, &arithmetic::FLOAT_ARITHMETIC, &arithmetic::INTEGER_ARITHMETIC, @@ -559,6 +563,7 @@ pub fn register_plugins(store: &mut rustc_lint::LintStore, sess: &Session, conf: &cargo_common_metadata::CARGO_COMMON_METADATA, &checked_conversions::CHECKED_CONVERSIONS, &cognitive_complexity::COGNITIVE_COMPLEXITY, + &collapsible_if::COLLAPSIBLE_ELSE_IF, &collapsible_if::COLLAPSIBLE_IF, &collapsible_match::COLLAPSIBLE_MATCH, &comparison_chain::COMPARISON_CHAIN, @@ -802,6 +807,7 @@ pub fn register_plugins(store: &mut rustc_lint::LintStore, sess: &Session, conf: &needless_borrowed_ref::NEEDLESS_BORROWED_REFERENCE, &needless_continue::NEEDLESS_CONTINUE, &needless_pass_by_value::NEEDLESS_PASS_BY_VALUE, + &needless_question_mark::NEEDLESS_QUESTION_MARK, &needless_update::NEEDLESS_UPDATE, &neg_cmp_op_on_partial_ord::NEG_CMP_OP_ON_PARTIAL_ORD, &neg_multiply::NEG_MULTIPLY, @@ -911,6 +917,7 @@ pub fn register_plugins(store: &mut rustc_lint::LintStore, sess: &Session, conf: &types::LET_UNIT_VALUE, &types::LINKEDLIST, &types::OPTION_OPTION, + &types::PTR_AS_PTR, &types::RC_BUFFER, &types::REDUNDANT_ALLOCATION, &types::TYPE_COMPLEXITY, @@ -938,6 +945,7 @@ pub fn register_plugins(store: &mut rustc_lint::LintStore, sess: &Session, conf: &use_self::USE_SELF, &useless_conversion::USELESS_CONVERSION, &vec::USELESS_VEC, + &vec_init_then_push::VEC_INIT_THEN_PUSH, &vec_resize_to_zero::VEC_RESIZE_TO_ZERO, &verbose_file_reads::VERBOSE_FILE_READS, &wildcard_dependencies::WILDCARD_DEPENDENCIES, @@ -1022,6 +1030,7 @@ pub fn register_plugins(store: &mut rustc_lint::LintStore, sess: &Session, conf: store.register_late_pass(move || box from_over_into::FromOverInto::new(msrv)); store.register_late_pass(move || box use_self::UseSelf::new(msrv)); store.register_late_pass(move || box missing_const_for_fn::MissingConstForFn::new(msrv)); + store.register_late_pass(move || box needless_question_mark::NeedlessQuestionMark::new(msrv)); store.register_late_pass(|| box size_of_in_element_count::SizeOfInElementCount); store.register_late_pass(|| box map_clone::MapClone); @@ -1218,6 +1227,8 @@ pub fn register_plugins(store: &mut rustc_lint::LintStore, sess: &Session, conf: store.register_late_pass(|| box strings::StrToString); store.register_late_pass(|| box strings::StringToString); store.register_late_pass(|| box zero_sized_map_values::ZeroSizedMapValues); + store.register_late_pass(|| box vec_init_then_push::VecInitThenPush::default()); + store.register_late_pass(move || box types::PtrAsPtr::new(msrv)); store.register_group(true, "clippy::restriction", Some("clippy_restriction"), vec![ LintId::of(&arithmetic::FLOAT_ARITHMETIC), @@ -1344,6 +1355,7 @@ pub fn register_plugins(store: &mut rustc_lint::LintStore, sess: &Session, conf: LintId::of(&types::LET_UNIT_VALUE), LintId::of(&types::LINKEDLIST), LintId::of(&types::OPTION_OPTION), + LintId::of(&types::PTR_AS_PTR), LintId::of(&unicode::NON_ASCII_LITERAL), LintId::of(&unicode::UNICODE_NOT_NFC), LintId::of(&unnested_or_patterns::UNNESTED_OR_PATTERNS), @@ -1365,6 +1377,7 @@ pub fn register_plugins(store: &mut rustc_lint::LintStore, sess: &Session, conf: LintId::of(&utils::internal_lints::MATCH_TYPE_ON_DIAGNOSTIC_ITEM), LintId::of(&utils::internal_lints::OUTER_EXPN_EXPN_DATA), LintId::of(&utils::internal_lints::PRODUCE_ICE), + LintId::of(&utils::internal_lints::UNNECESSARY_SYMBOL_STR), ]); store.register_group(true, "clippy::all", Some("clippy"), vec![ @@ -1386,6 +1399,7 @@ pub fn register_plugins(store: &mut rustc_lint::LintStore, sess: &Session, conf: LintId::of(&booleans::LOGIC_BUG), LintId::of(&booleans::NONMINIMAL_BOOL), LintId::of(&bytecount::NAIVE_BYTECOUNT), + LintId::of(&collapsible_if::COLLAPSIBLE_ELSE_IF), LintId::of(&collapsible_if::COLLAPSIBLE_IF), LintId::of(&collapsible_match::COLLAPSIBLE_MATCH), LintId::of(&comparison_chain::COMPARISON_CHAIN), @@ -1547,6 +1561,7 @@ pub fn register_plugins(store: &mut rustc_lint::LintStore, sess: &Session, conf: LintId::of(&needless_bool::BOOL_COMPARISON), LintId::of(&needless_bool::NEEDLESS_BOOL), LintId::of(&needless_borrowed_ref::NEEDLESS_BORROWED_REFERENCE), + LintId::of(&needless_question_mark::NEEDLESS_QUESTION_MARK), LintId::of(&needless_update::NEEDLESS_UPDATE), LintId::of(&neg_cmp_op_on_partial_ord::NEG_CMP_OP_ON_PARTIAL_ORD), LintId::of(&neg_multiply::NEG_MULTIPLY), @@ -1638,6 +1653,7 @@ pub fn register_plugins(store: &mut rustc_lint::LintStore, sess: &Session, conf: LintId::of(&unwrap::UNNECESSARY_UNWRAP), LintId::of(&useless_conversion::USELESS_CONVERSION), LintId::of(&vec::USELESS_VEC), + LintId::of(&vec_init_then_push::VEC_INIT_THEN_PUSH), LintId::of(&vec_resize_to_zero::VEC_RESIZE_TO_ZERO), LintId::of(&write::PRINTLN_EMPTY_STRING), LintId::of(&write::PRINT_LITERAL), @@ -1654,6 +1670,7 @@ pub fn register_plugins(store: &mut rustc_lint::LintStore, sess: &Session, conf: LintId::of(&attrs::BLANKET_CLIPPY_RESTRICTION_LINTS), LintId::of(&blacklisted_name::BLACKLISTED_NAME), LintId::of(&blocks_in_if_conditions::BLOCKS_IN_IF_CONDITIONS), + LintId::of(&collapsible_if::COLLAPSIBLE_ELSE_IF), LintId::of(&collapsible_if::COLLAPSIBLE_IF), LintId::of(&collapsible_match::COLLAPSIBLE_MATCH), LintId::of(&comparison_chain::COMPARISON_CHAIN), @@ -1804,6 +1821,7 @@ pub fn register_plugins(store: &mut rustc_lint::LintStore, sess: &Session, conf: LintId::of(&needless_bool::BOOL_COMPARISON), LintId::of(&needless_bool::NEEDLESS_BOOL), LintId::of(&needless_borrowed_ref::NEEDLESS_BORROWED_REFERENCE), + LintId::of(&needless_question_mark::NEEDLESS_QUESTION_MARK), LintId::of(&needless_update::NEEDLESS_UPDATE), LintId::of(&neg_cmp_op_on_partial_ord::NEG_CMP_OP_ON_PARTIAL_ORD), LintId::of(&no_effect::NO_EFFECT), @@ -1936,6 +1954,7 @@ pub fn register_plugins(store: &mut rustc_lint::LintStore, sess: &Session, conf: LintId::of(&types::BOX_VEC), LintId::of(&types::REDUNDANT_ALLOCATION), LintId::of(&vec::USELESS_VEC), + LintId::of(&vec_init_then_push::VEC_INIT_THEN_PUSH), ]); store.register_group(true, "clippy::cargo", Some("clippy_cargo"), vec). /// /// **Example:** /// ```rust,no_run diff --git a/clippy_lints/src/manual_async_fn.rs b/clippy_lints/src/manual_async_fn.rs index 29439e52c48..89f5b2ff311 100644 --- a/clippy_lints/src/manual_async_fn.rs +++ b/clippy_lints/src/manual_async_fn.rs @@ -9,7 +9,7 @@ use rustc_hir::{ }; use rustc_lint::{LateContext, LateLintPass}; use rustc_session::{declare_lint_pass, declare_tool_lint}; -use rustc_span::Span; +use rustc_span::{sym, Span}; declare_clippy_lint! { /// **What it does:** It checks for manual implementations of `async` functions. @@ -137,7 +137,7 @@ fn future_output_ty<'tcx>(trait_ref: &'tcx TraitRef<'tcx>) -> Option<&'tcx Ty<'t if let Some(args) = segment.args; if args.bindings.len() == 1; let binding = &args.bindings[0]; - if binding.ident.as_str() == "Output"; + if binding.ident.name == sym::Output; if let TypeBindingKind::Equality{ty: output} = binding.kind; then { return Some(output) diff --git a/clippy_lints/src/map_clone.rs b/clippy_lints/src/map_clone.rs index 220240acb7a..1818836d5d5 100644 --- a/clippy_lints/src/map_clone.rs +++ b/clippy_lints/src/map_clone.rs @@ -53,7 +53,7 @@ impl<'tcx> LateLintPass<'tcx> for MapClone { if_chain! { if let hir::ExprKind::MethodCall(ref method, _, ref args, _) = e.kind; if args.len() == 2; - if method.ident.as_str() == "map"; + if method.ident.name == sym::map; let ty = cx.typeck_results().expr_ty(&args[0]); if is_type_diagnostic_item(cx, ty, sym::option_type) || match_trait_method(cx, e, &paths::ITERATOR); if let hir::ExprKind::Closure(_, _, body_id, _, _) = args[1].kind; diff --git a/clippy_lints/src/map_identity.rs b/clippy_lints/src/map_identity.rs index 6b782385a38..9f9c108a85a 100644 --- a/clippy_lints/src/map_identity.rs +++ b/clippy_lints/src/map_identity.rs @@ -63,7 +63,7 @@ impl<'tcx> LateLintPass<'tcx> for MapIdentity { fn get_map_argument<'a>(cx: &LateContext<'_>, expr: &'a Expr<'a>) -> Option<&'a [Expr<'a>]> { if_chain! { if let ExprKind::MethodCall(ref method, _, ref args, _) = expr.kind; - if args.len() == 2 && method.ident.as_str() == "map"; + if args.len() == 2 && method.ident.name == sym::map; let caller_ty = cx.typeck_results().expr_ty(&args[0]); if match_trait_method(cx, expr, &paths::ITERATOR) || is_type_diagnostic_item(cx, caller_ty, sym::result_type) diff --git a/clippy_lints/src/methods/mod.rs b/clippy_lints/src/methods/mod.rs index f7231bba175..7adf6bdeac5 100644 --- a/clippy_lints/src/methods/mod.rs +++ b/clippy_lints/src/methods/mod.rs @@ -3096,7 +3096,7 @@ fn lint_flat_map_identity<'tcx>( if let hir::ExprKind::Path(hir::QPath::Resolved(_, ref path)) = body.value.kind; if path.segments.len() == 1; - if path.segments[0].ident.as_str() == binding_ident.as_str(); + if path.segments[0].ident.name == binding_ident.name; then { apply_lint("called `flat_map(|x| x)` on an `Iterator`"); diff --git a/clippy_lints/src/minmax.rs b/clippy_lints/src/minmax.rs index 004dd50a31b..8d0c3b8e0fe 100644 --- a/clippy_lints/src/minmax.rs +++ b/clippy_lints/src/minmax.rs @@ -89,9 +89,9 @@ fn min_max<'a>(cx: &LateContext<'_>, expr: &'a Expr<'a>) -> Option<(MinMax, Cons if let [obj, _] = args; if cx.typeck_results().expr_ty(obj).is_floating_point() || match_trait_method(cx, expr, &paths::ORD); then { - if path.ident.as_str() == sym!(max).as_str() { + if path.ident.name == sym!(max) { fetch_const(cx, args, MinMax::Max) - } else if path.ident.as_str() == sym!(min).as_str() { + } else if path.ident.name == sym!(min) { fetch_const(cx, args, MinMax::Min) } else { None diff --git a/clippy_lints/src/missing_doc.rs b/clippy_lints/src/missing_doc.rs index 27f1074a0dd..0e49eaab436 100644 --- a/clippy_lints/src/missing_doc.rs +++ b/clippy_lints/src/missing_doc.rs @@ -63,7 +63,7 @@ impl MissingDoc { if let Some(meta) = list.get(0); if let Some(name) = meta.ident(); then { - name.as_str() == "include" + name.name == sym::include } else { false } diff --git a/clippy_lints/src/needless_bool.rs b/clippy_lints/src/needless_bool.rs index 6b9a37b5252..d795f126457 100644 --- a/clippy_lints/src/needless_bool.rs +++ b/clippy_lints/src/needless_bool.rs @@ -3,9 +3,7 @@ //! This lint is **warn** by default use crate::utils::sugg::Sugg; -use crate::utils::{ - is_expn_of, parent_node_is_if_expr, snippet_with_applicability, span_lint, span_lint_and_sugg, -}; +use crate::utils::{is_expn_of, parent_node_is_if_expr, snippet_with_applicability, span_lint, span_lint_and_sugg}; use rustc_ast::ast::LitKind; use rustc_errors::Applicability; use rustc_hir::{BinOpKind, Block, Expr, ExprKind, StmtKind, UnOp}; diff --git a/clippy_lints/src/needless_borrow.rs b/clippy_lints/src/needless_borrow.rs index bff53eb8cca..f1c06692e30 100644 --- a/clippy_lints/src/needless_borrow.rs +++ b/clippy_lints/src/needless_borrow.rs @@ -2,7 +2,7 @@ //! //! This lint is **warn** by default -use crate::utils::{snippet_opt, span_lint_and_then}; +use crate::utils::{is_automatically_derived, snippet_opt, span_lint_and_then}; use if_chain::if_chain; use rustc_errors::Applicability; use rustc_hir::{BindingAnnotation, BorrowKind, Expr, ExprKind, HirId, Item, Mutability, Pat, PatKind}; @@ -10,7 +10,6 @@ use rustc_lint::{LateContext, LateLintPass}; use rustc_middle::ty; use rustc_middle::ty::adjustment::{Adjust, Adjustment}; use rustc_session::{declare_tool_lint, impl_lint_pass}; -use rustc_span::sym; declare_clippy_lint! { /// **What it does:** Checks for address of operations (`&`) that are going to @@ -116,7 +115,7 @@ impl<'tcx> LateLintPass<'tcx> for NeedlessBorrow { } fn check_item(&mut self, _: &LateContext<'tcx>, item: &'tcx Item<'_>) { - if item.attrs.iter().any(|a| a.has_name(sym::automatically_derived)) { + if is_automatically_derived(item.attrs) { debug_assert!(self.derived_item.is_none()); self.derived_item = Some(item.hir_id); } diff --git a/clippy_lints/src/needless_pass_by_value.rs b/clippy_lints/src/needless_pass_by_value.rs index 3b71f1b46e2..89fe2c19a57 100644 --- a/clippy_lints/src/needless_pass_by_value.rs +++ b/clippy_lints/src/needless_pass_by_value.rs @@ -8,11 +8,12 @@ use rustc_ast::ast::Attribute; use rustc_data_structures::fx::{FxHashMap, FxHashSet}; use rustc_errors::{Applicability, DiagnosticBuilder}; use rustc_hir::intravisit::FnKind; -use rustc_hir::{BindingAnnotation, Body, FnDecl, GenericArg, HirId, ItemKind, Impl, Node, PatKind, QPath, TyKind}; +use rustc_hir::{BindingAnnotation, Body, FnDecl, GenericArg, HirId, Impl, ItemKind, Node, PatKind, QPath, TyKind}; use rustc_infer::infer::TyCtxtInferExt; use rustc_lint::{LateContext, LateLintPass}; use rustc_middle::ty::{self, TypeFoldable}; use rustc_session::{declare_lint_pass, declare_tool_lint}; +use rustc_span::symbol::kw; use rustc_span::{sym, Span}; use rustc_target::spec::abi::Abi; use rustc_trait_selection::traits; @@ -151,7 +152,7 @@ impl<'tcx> LateLintPass<'tcx> for NeedlessPassByValue { // Ignore `self`s. if idx == 0 { if let PatKind::Binding(.., ident, _) = arg.pat.kind { - if ident.as_str() == "self" { + if ident.name == kw::SelfLower { continue; } } diff --git a/clippy_lints/src/needless_question_mark.rs b/clippy_lints/src/needless_question_mark.rs new file mode 100644 index 00000000000..9e9b79ee1cf --- /dev/null +++ b/clippy_lints/src/needless_question_mark.rs @@ -0,0 +1,232 @@ +use rustc_errors::Applicability; +use rustc_hir::def::{CtorKind, CtorOf, DefKind, Res}; +use rustc_hir::{Body, Expr, ExprKind, LangItem, MatchSource, QPath}; +use rustc_lint::{LateContext, LateLintPass, LintContext}; +use rustc_middle::ty::DefIdTree; +use rustc_semver::RustcVersion; +use rustc_session::{declare_tool_lint, impl_lint_pass}; +use rustc_span::sym; + +use crate::utils; +use if_chain::if_chain; + +declare_clippy_lint! { + /// **What it does:** + /// Suggests alternatives for useless applications of `?` in terminating expressions + /// + /// **Why is this bad?** There's no reason to use `?` to short-circuit when execution of the body will end there anyway. + /// + /// **Known problems:** None. + /// + /// **Example:** + /// + /// ```rust + /// struct TO { + /// magic: Option<usize>, + /// } + /// + /// fn f(to: TO) -> Option<usize> { + /// Some(to.magic?) + /// } + /// + /// struct TR { + /// magic: Result<usize, bool>, + /// } + /// + /// fn g(tr: Result<TR, bool>) -> Result<usize, bool> { + /// tr.and_then(|t| Ok(t.magic?)) + /// } + /// + /// ``` + /// Use instead: + /// ```rust + /// struct TO { + /// magic: Option<usize>, + /// } + /// + /// fn f(to: TO) -> Option<usize> { + /// to.magic + /// } + /// + /// struct TR { + /// magic: Result<usize, bool>, + /// } + /// + /// fn g(tr: Result<TR, bool>) -> Result<usize, bool> { + /// tr.and_then(|t| t.magic) + /// } + /// ``` + pub NEEDLESS_QUESTION_MARK, + complexity, + "Suggest `value.inner_option` instead of `Some(value.inner_option?)`. The same goes for `Result<T, E>`." +} + +const NEEDLESS_QUESTION_MARK_RESULT_MSRV: RustcVersion = RustcVersion::new(1, 13, 0); +const NEEDLESS_QUESTION_MARK_OPTION_MSRV: RustcVersion = RustcVersion::new(1, 22, 0); + +pub struct NeedlessQuestionMark { + msrv: Option<RustcVersion>, +} + +impl NeedlessQuestionMark { + #[must_use] + pub fn new(msrv: Option<RustcVersion>) -> Self { + Self { msrv } + } +} + +impl_lint_pass!(NeedlessQuestionMark => [NEEDLESS_QUESTION_MARK]); + +#[derive(Debug)] +enum SomeOkCall<'a> { + SomeCall(&'a Expr<'a>, &'a Expr<'a>), + OkCall(&'a Expr<'a>, &'a Expr<'a>), +} + +impl LateLintPass<'_> for NeedlessQuestionMark { + /* + * The question mark operator is compatible with both Result<T, E> and Option<T>, + * from Rust 1.13 and 1.22 respectively. + */ + + /* + * What do we match: + * Expressions that look like this: + * Some(option?), Ok(result?) + * + * Where do we match: + * Last expression of a body + * Return statement + * A body's value (single line closure) + * + * What do we not match: + * Implicit calls to `from(..)` on the error value + */ + + fn check_expr(&mut self, cx: &LateContext<'_>, expr: &'_ Expr<'_>) { + let e = match &expr.kind { + ExprKind::Ret(Some(e)) => e, + _ => return, + }; + + if let Some(ok_some_call) = is_some_or_ok_call(self, cx, e) { + emit_lint(cx, &ok_some_call); + } + } + + fn check_body(&mut self, cx: &LateContext<'_>, body: &'_ Body<'_>) { + // Function / Closure block + let expr_opt = if let ExprKind::Block(block, _) = &body.value.kind { + block.expr + } else { + // Single line closure + Some(&body.value) + }; + + if_chain! { + if let Some(expr) = expr_opt; + if let Some(ok_some_call) = is_some_or_ok_call(self, cx, expr); + then { + emit_lint(cx, &ok_some_call); + } + }; + } + + extract_msrv_attr!(LateContext); +} + +fn emit_lint(cx: &LateContext<'_>, expr: &SomeOkCall<'_>) { + let (entire_expr, inner_expr) = match expr { + SomeOkCall::OkCall(outer, inner) | SomeOkCall::SomeCall(outer, inner) => (outer, inner), + }; + + utils::span_lint_and_sugg( + cx, + NEEDLESS_QUESTION_MARK, + entire_expr.span, + "Question mark operator is useless here", + "try", + format!("{}", utils::snippet(cx, inner_expr.span, r#""...""#)), + Applicability::MachineApplicable, + ); +} + +fn is_some_or_ok_call<'a>( + nqml: &NeedlessQuestionMark, + cx: &'a LateContext<'_>, + expr: &'a Expr<'_>, +) -> Option<SomeOkCall<'a>> { + if_chain! { + // Check outer expression matches CALL_IDENT(ARGUMENT) format + if let ExprKind::Call(path, args) = &expr.kind; + if let ExprKind::Path(QPath::Resolved(None, path)) = &path.kind; + if is_some_ctor(cx, path.res) || is_ok_ctor(cx, path.res); + + // Extract inner expression from ARGUMENT + if let ExprKind::Match(inner_expr_with_q, _, MatchSource::TryDesugar) = &args[0].kind; + if let ExprKind::Call(called, args) = &inner_expr_with_q.kind; + if args.len() == 1; + + if let ExprKind::Path(QPath::LangItem(LangItem::TryIntoResult, _)) = &called.kind; + then { + // Extract inner expr type from match argument generated by + // question mark operator + let inner_expr = &args[0]; + + let inner_ty = cx.typeck_results().expr_ty(inner_expr); + let outer_ty = cx.typeck_results().expr_ty(expr); + + // Check if outer and inner type are Option + let outer_is_some = utils::is_type_diagnostic_item(cx, outer_ty, sym::option_type); + let inner_is_some = utils::is_type_diagnostic_item(cx, inner_ty, sym::option_type); + + // Check for Option MSRV + let meets_option_msrv = utils::meets_msrv(nqml.msrv.as_ref(), &NEEDLESS_QUESTION_MARK_OPTION_MSRV); + if outer_is_some && inner_is_some && meets_option_msrv { + return Some(SomeOkCall::SomeCall(expr, inner_expr)); + } + + // Check if outer and inner type are Result + let outer_is_result = utils::is_type_diagnostic_item(cx, outer_ty, sym::result_type); + let inner_is_result = utils::is_type_diagnostic_item(cx, inner_ty, sym::result_type); + + // Additional check: if the error type of the Result can be converted + // via the From trait, then don't match + let does_not_call_from = !has_implicit_error_from(cx, expr, inner_expr); + + // Must meet Result MSRV + let meets_result_msrv = utils::meets_msrv(nqml.msrv.as_ref(), &NEEDLESS_QUESTION_MARK_RESULT_MSRV); + if outer_is_result && inner_is_result && does_not_call_from && meets_result_msrv { + return Some(SomeOkCall::OkCall(expr, inner_expr)); + } + } + } + + None +} + +fn has_implicit_error_from(cx: &LateContext<'_>, entire_expr: &Expr<'_>, inner_result_expr: &Expr<'_>) -> bool { + return cx.typeck_results().expr_ty(entire_expr) != cx.typeck_results().expr_ty(inner_result_expr); +} + +fn is_ok_ctor(cx: &LateContext<'_>, res: Res) -> bool { + if let Some(ok_id) = cx.tcx.lang_items().result_ok_variant() { + if let Res::Def(DefKind::Ctor(CtorOf::Variant, CtorKind::Fn), id) = res { + if let Some(variant_id) = cx.tcx.parent(id) { + return variant_id == ok_id; + } + } + } + false +} + +fn is_some_ctor(cx: &LateContext<'_>, res: Res) -> bool { + if let Some(some_id) = cx.tcx.lang_items().option_some_variant() { + if let Res::Def(DefKind::Ctor(CtorOf::Variant, CtorKind::Fn), id) = res { + if let Some(variant_id) = cx.tcx.parent(id) { + return variant_id == some_id; + } + } + } + false +} diff --git a/clippy_lints/src/option_if_let_else.rs b/clippy_lints/src/option_if_let_else.rs index 391f893ef35..7bdf975ffd4 100644 --- a/clippy_lints/src/option_if_let_else.rs +++ b/clippy_lints/src/option_if_let_else.rs @@ -66,7 +66,7 @@ declare_lint_pass!(OptionIfLetElse => [OPTION_IF_LET_ELSE]); /// Returns true iff the given expression is the result of calling `Result::ok` fn is_result_ok(cx: &LateContext<'_>, expr: &'_ Expr<'_>) -> bool { if let ExprKind::MethodCall(ref path, _, &[ref receiver], _) = &expr.kind { - path.ident.name.to_ident_string() == "ok" + path.ident.name.as_str() == "ok" && is_type_diagnostic_item(cx, &cx.typeck_results().expr_ty(&receiver), sym::result_type) } else { false @@ -110,7 +110,7 @@ fn extract_body_from_arm<'a>(arm: &'a Arm<'a>) -> Option<&'a Expr<'a>> { fn should_wrap_in_braces(cx: &LateContext<'_>, expr: &Expr<'_>) -> bool { utils::get_enclosing_block(cx, expr.hir_id).map_or(false, |parent| { let mut should_wrap = false; - + if let Some(Expr { kind: ExprKind::Match( @@ -124,7 +124,11 @@ fn should_wrap_in_braces(cx: &LateContext<'_>, expr: &Expr<'_>) -> bool { }) = parent.expr { should_wrap = expr.hir_id == arms[1].body.hir_id; - } else if let Some(Expr { kind: ExprKind::If(_, _, Some(else_clause)), .. }) = parent.expr { + } else if let Some(Expr { + kind: ExprKind::If(_, _, Some(else_clause)), + .. + }) = parent.expr + { should_wrap = expr.hir_id == else_clause.hir_id; } diff --git a/clippy_lints/src/partialeq_ne_impl.rs b/clippy_lints/src/partialeq_ne_impl.rs index 04b6e5d5847..ed314937ce8 100644 --- a/clippy_lints/src/partialeq_ne_impl.rs +++ b/clippy_lints/src/partialeq_ne_impl.rs @@ -1,6 +1,6 @@ use crate::utils::{is_automatically_derived, span_lint_hir}; use if_chain::if_chain; -use rustc_hir::{Item, ItemKind, Impl}; +use rustc_hir::{Impl, Item, ItemKind}; use rustc_lint::{LateContext, LateLintPass}; use rustc_session::{declare_lint_pass, declare_tool_lint}; use rustc_span::sym; diff --git a/clippy_lints/src/pass_by_ref_or_value.rs b/clippy_lints/src/pass_by_ref_or_value.rs index 7814065e31a..d96a9b025f0 100644 --- a/clippy_lints/src/pass_by_ref_or_value.rs +++ b/clippy_lints/src/pass_by_ref_or_value.rs @@ -6,7 +6,7 @@ use rustc_ast::attr; use rustc_errors::Applicability; use rustc_hir as hir; use rustc_hir::intravisit::FnKind; -use rustc_hir::{BindingAnnotation, Body, FnDecl, HirId, ItemKind, MutTy, Mutability, Node, PatKind, Impl}; +use rustc_hir::{BindingAnnotation, Body, FnDecl, HirId, Impl, ItemKind, MutTy, Mutability, Node, PatKind}; use rustc_lint::{LateContext, LateLintPass}; use rustc_middle::ty; use rustc_session::{declare_tool_lint, impl_lint_pass}; @@ -63,7 +63,7 @@ declare_clippy_lint! { /// /// **Why is this bad?** Arguments passed by value might result in an unnecessary /// shallow copy, taking up more space in the stack and requiring a call to - /// `memcpy`, which which can be expensive. + /// `memcpy`, which can be expensive. /// /// **Example:** /// diff --git a/clippy_lints/src/ptr.rs b/clippy_lints/src/ptr.rs index b832add009f..c6329a1381c 100644 --- a/clippy_lints/src/ptr.rs +++ b/clippy_lints/src/ptr.rs @@ -8,8 +8,8 @@ use crate::utils::{ use if_chain::if_chain; use rustc_errors::Applicability; use rustc_hir::{ - BinOpKind, BodyId, Expr, ExprKind, FnDecl, FnRetTy, GenericArg, HirId, ImplItem, ImplItemKind, Item, ItemKind, Impl, - Lifetime, MutTy, Mutability, Node, PathSegment, QPath, TraitFn, TraitItem, TraitItemKind, Ty, TyKind, + BinOpKind, BodyId, Expr, ExprKind, FnDecl, FnRetTy, GenericArg, HirId, Impl, ImplItem, ImplItemKind, Item, + ItemKind, Lifetime, MutTy, Mutability, Node, PathSegment, QPath, TraitFn, TraitItem, TraitItemKind, Ty, TyKind, }; use rustc_lint::{LateContext, LateLintPass}; use rustc_middle::ty; diff --git a/clippy_lints/src/ref_option_ref.rs b/clippy_lints/src/ref_option_ref.rs index 803ebada54b..8cd6692ce03 100644 --- a/clippy_lints/src/ref_option_ref.rs +++ b/clippy_lints/src/ref_option_ref.rs @@ -13,7 +13,7 @@ declare_clippy_lint! { /// **Why is this bad?** Since `&` is Copy, it's useless to have a /// reference on `Option<&T>`. /// - /// **Known problems:** It may be irrevelent to use this lint on + /// **Known problems:** It may be irrelevant to use this lint on /// public API code as it will make a breaking change to apply it. /// /// **Example:** diff --git a/clippy_lints/src/returns.rs b/clippy_lints/src/returns.rs index 35827e027aa..63548d8fdb4 100644 --- a/clippy_lints/src/returns.rs +++ b/clippy_lints/src/returns.rs @@ -202,7 +202,7 @@ fn check_final_expr<'tcx>( check_final_expr(cx, &arm.body, Some(arm.body.span), RetReplacement::Block); } }, - | MatchSource::IfLetDesugar { + MatchSource::IfLetDesugar { contains_else_clause: true, } => { if let ExprKind::Block(ref ifblock, _) = arms[0].body.kind { @@ -217,6 +217,9 @@ fn check_final_expr<'tcx>( } fn emit_return_lint(cx: &LateContext<'_>, ret_span: Span, inner_span: Option<Span>, replacement: RetReplacement) { + if ret_span.from_expansion() { + return; + } match inner_span { Some(inner_span) => { if in_external_macro(cx.tcx.sess, inner_span) || inner_span.from_expansion() { diff --git a/clippy_lints/src/serde_api.rs b/clippy_lints/src/serde_api.rs index ca4fd9f3559..44e739725c8 100644 --- a/clippy_lints/src/serde_api.rs +++ b/clippy_lints/src/serde_api.rs @@ -1,5 +1,5 @@ use crate::utils::{get_trait_def_id, paths, span_lint}; -use rustc_hir::{Item, ItemKind, Impl}; +use rustc_hir::{Impl, Item, ItemKind}; use rustc_lint::{LateContext, LateLintPass}; use rustc_session::{declare_lint_pass, declare_tool_lint}; diff --git a/clippy_lints/src/shadow.rs b/clippy_lints/src/shadow.rs index f2f3dfa09a7..24da056770c 100644 --- a/clippy_lints/src/shadow.rs +++ b/clippy_lints/src/shadow.rs @@ -396,5 +396,5 @@ fn is_self_shadow(name: Symbol, expr: &Expr<'_>) -> bool { } fn path_eq_name(name: Symbol, path: &Path<'_>) -> bool { - !path.is_global() && path.segments.len() == 1 && path.segments[0].ident.as_str() == name.as_str() + !path.is_global() && path.segments.len() == 1 && path.segments[0].ident.name == name } diff --git a/clippy_lints/src/swap.rs b/clippy_lints/src/swap.rs index 386987eb181..699fd51ccc1 100644 --- a/clippy_lints/src/swap.rs +++ b/clippy_lints/src/swap.rs @@ -91,7 +91,7 @@ fn check_manual_swap(cx: &LateContext<'_>, block: &Block<'_>) { if let ExprKind::Path(QPath::Resolved(None, ref rhs2)) = rhs2.kind; if rhs2.segments.len() == 1; - if ident.as_str() == rhs2.segments[0].ident.as_str(); + if ident.name == rhs2.segments[0].ident.name; if eq_expr_value(cx, tmp_init, lhs1); if eq_expr_value(cx, rhs1, lhs2); then { diff --git a/clippy_lints/src/to_string_in_display.rs b/clippy_lints/src/to_string_in_display.rs index 675eaf4277a..c53727ba160 100644 --- a/clippy_lints/src/to_string_in_display.rs +++ b/clippy_lints/src/to_string_in_display.rs @@ -1,7 +1,7 @@ use crate::utils::{match_def_path, match_trait_method, paths, qpath_res, span_lint}; use if_chain::if_chain; use rustc_hir::def::Res; -use rustc_hir::{Expr, ExprKind, HirId, ImplItem, ImplItemKind, Item, ItemKind, Impl}; +use rustc_hir::{Expr, ExprKind, HirId, Impl, ImplItem, ImplItemKind, Item, ItemKind}; use rustc_lint::{LateContext, LateLintPass}; use rustc_session::{declare_tool_lint, impl_lint_pass}; diff --git a/clippy_lints/src/types.rs b/clippy_lints/src/types.rs index 2696c5e781a..3b5a83d2a0b 100644 --- a/clippy_lints/src/types.rs +++ b/clippy_lints/src/types.rs @@ -8,7 +8,6 @@ use if_chain::if_chain; use rustc_ast::{FloatTy, IntTy, LitFloatType, LitIntType, LitKind, UintTy}; use rustc_errors::{Applicability, DiagnosticBuilder}; use rustc_hir as hir; -use rustc_hir::def::Res; use rustc_hir::intravisit::{walk_body, walk_expr, walk_ty, FnKind, NestedVisitorMap, Visitor}; use rustc_hir::{ BinOpKind, Block, Body, Expr, ExprKind, FnDecl, FnRetTy, FnSig, GenericArg, GenericBounds, GenericParamKind, HirId, @@ -19,7 +18,8 @@ use rustc_lint::{LateContext, LateLintPass, LintContext}; use rustc_middle::hir::map::Map; use rustc_middle::lint::in_external_macro; use rustc_middle::ty::TypeFoldable; -use rustc_middle::ty::{self, InferTy, Ty, TyCtxt, TyS, TypeckResults}; +use rustc_middle::ty::{self, InferTy, Ty, TyCtxt, TyS, TypeAndMut, TypeckResults}; +use rustc_semver::RustcVersion; use rustc_session::{declare_lint_pass, declare_tool_lint, impl_lint_pass}; use rustc_span::hygiene::{ExpnKind, MacroKind}; use rustc_span::source_map::Span; @@ -30,11 +30,13 @@ use rustc_typeck::hir_ty_to_ty; use crate::consts::{constant, Constant}; use crate::utils::paths; +use crate::utils::sugg::Sugg; use crate::utils::{ - clip, comparisons, differing_macro_contexts, higher, in_constant, indent_of, int_bits, is_type_diagnostic_item, - last_path_segment, match_def_path, match_path, method_chain_args, multispan_sugg, numeric_literal::NumericLiteral, - qpath_res, reindent_multiline, sext, snippet, snippet_opt, snippet_with_applicability, snippet_with_macro_callsite, - span_lint, span_lint_and_help, span_lint_and_sugg, span_lint_and_then, unsext, + clip, comparisons, differing_macro_contexts, higher, in_constant, indent_of, int_bits, is_hir_ty_cfg_dependant, + is_type_diagnostic_item, last_path_segment, match_def_path, match_path, meets_msrv, method_chain_args, + multispan_sugg, numeric_literal::NumericLiteral, qpath_res, reindent_multiline, sext, snippet, snippet_opt, + snippet_with_applicability, snippet_with_macro_callsite, span_lint, span_lint_and_help, span_lint_and_sugg, + span_lint_and_then, unsext, }; declare_clippy_lint! { @@ -73,7 +75,7 @@ declare_clippy_lint! { /// **Why is this bad?** `Vec` already keeps its contents in a separate area on /// the heap. So if you `Box` its contents, you just add another level of indirection. /// - /// **Known problems:** Vec<Box<T: Sized>> makes sense if T is a large type (see #3530, + /// **Known problems:** Vec<Box<T: Sized>> makes sense if T is a large type (see [#3530](https://github.com/rust-lang/rust-clippy/issues/3530), /// 1st comment). /// /// **Example:** @@ -1279,8 +1281,8 @@ declare_clippy_lint! { } declare_clippy_lint! { - /// **What it does:** Checks for casts from a less-strictly-aligned pointer to a - /// more-strictly-aligned pointer + /// **What it does:** Checks for casts, using `as` or `pointer::cast`, + /// from a less-strictly-aligned pointer to a more-strictly-aligned pointer /// /// **Why is this bad?** Dereferencing the resulting pointer may be undefined /// behavior. @@ -1293,6 +1295,9 @@ declare_clippy_lint! { /// ```rust /// let _ = (&1u8 as *const u8) as *const u16; /// let _ = (&mut 1u8 as *mut u8) as *mut u16; + /// + /// (&1u8 as *const u8).cast::<u16>(); + /// (&mut 1u8 as *mut u8).cast::<u16>(); /// ``` pub CAST_PTR_ALIGNMENT, pedantic, @@ -1634,12 +1639,8 @@ impl<'tcx> LateLintPass<'tcx> for Casts { return; } if let ExprKind::Cast(ref ex, cast_to) = expr.kind { - if let TyKind::Path(QPath::Resolved(_, path)) = cast_to.kind { - if let Res::Def(_, def_id) = path.res { - if cx.tcx.has_attr(def_id, sym::cfg) || cx.tcx.has_attr(def_id, sym::cfg_attr) { - return; - } - } + if is_hir_ty_cfg_dependant(cx, cast_to) { + return; } let (cast_from, cast_to) = (cx.typeck_results().expr_ty(ex), cx.typeck_results().expr_ty(expr)); lint_fn_to_numeric_cast(cx, expr, ex, cast_from, cast_to); @@ -1689,6 +1690,19 @@ impl<'tcx> LateLintPass<'tcx> for Casts { } lint_cast_ptr_alignment(cx, expr, cast_from, cast_to); + } else if let ExprKind::MethodCall(method_path, _, args, _) = expr.kind { + if_chain! { + if method_path.ident.name == sym!(cast); + if let Some(generic_args) = method_path.args; + if let [GenericArg::Type(cast_to)] = generic_args.args; + // There probably is no obvious reason to do this, just to be consistent with `as` cases. + if !is_hir_ty_cfg_dependant(cx, cast_to); + then { + let (cast_from, cast_to) = + (cx.typeck_results().expr_ty(&args[0]), cx.typeck_results().expr_ty(expr)); + lint_cast_ptr_alignment(cx, expr, cast_from, cast_to); + } + } } } } @@ -2873,3 +2887,93 @@ impl<'tcx> LateLintPass<'tcx> for RefToMut { } } } + +const PTR_AS_PTR_MSRV: RustcVersion = RustcVersion::new(1, 38, 0); + +declare_clippy_lint! { + /// **What it does:** + /// Checks for `as` casts between raw pointers without changing its mutability, + /// namely `*const T` to `*const U` and `*mut T` to `*mut U`. + /// + /// **Why is this bad?** + /// Though `as` casts between raw pointers is not terrible, `pointer::cast` is safer because + /// it cannot accidentally change the pointer's mutability nor cast the pointer to other types like `usize`. + /// + /// **Known problems:** None. + /// + /// **Example:** + /// + /// ```rust + /// let ptr: *const u32 = &42_u32; + /// let mut_ptr: *mut u32 = &mut 42_u32; + /// let _ = ptr as *const i32; + /// let _ = mut_ptr as *mut i32; + /// ``` + /// Use instead: + /// ```rust + /// let ptr: *const u32 = &42_u32; + /// let mut_ptr: *mut u32 = &mut 42_u32; + /// let _ = ptr.cast::<i32>(); + /// let _ = mut_ptr.cast::<i32>(); + /// ``` + pub PTR_AS_PTR, + pedantic, + "casting using `as` from and to raw pointers that doesn't change its mutability, where `pointer::cast` could take the place of `as`" +} + +pub struct PtrAsPtr { + msrv: Option<RustcVersion>, +} + +impl PtrAsPtr { + #[must_use] + pub fn new(msrv: Option<RustcVersion>) -> Self { + Self { msrv } + } +} + +impl_lint_pass!(PtrAsPtr => [PTR_AS_PTR]); + +impl<'tcx> LateLintPass<'tcx> for PtrAsPtr { + fn check_expr(&mut self, cx: &LateContext<'tcx>, expr: &'tcx Expr<'_>) { + if !meets_msrv(self.msrv.as_ref(), &PTR_AS_PTR_MSRV) { + return; + } + + if expr.span.from_expansion() { + return; + } + + if_chain! { + if let ExprKind::Cast(cast_expr, cast_to_hir_ty) = expr.kind; + let (cast_from, cast_to) = (cx.typeck_results().expr_ty(cast_expr), cx.typeck_results().expr_ty(expr)); + if let ty::RawPtr(TypeAndMut { mutbl: from_mutbl, .. }) = cast_from.kind(); + if let ty::RawPtr(TypeAndMut { ty: to_pointee_ty, mutbl: to_mutbl }) = cast_to.kind(); + if matches!((from_mutbl, to_mutbl), + (Mutability::Not, Mutability::Not) | (Mutability::Mut, Mutability::Mut)); + // The `U` in `pointer::cast` have to be `Sized` + // as explained here: https://github.com/rust-lang/rust/issues/60602. + if to_pointee_ty.is_sized(cx.tcx.at(expr.span), cx.param_env); + then { + let mut applicability = Applicability::MachineApplicable; + let cast_expr_sugg = Sugg::hir_with_applicability(cx, cast_expr, "_", &mut applicability); + let turbofish = match &cast_to_hir_ty.kind { + TyKind::Infer => Cow::Borrowed(""), + TyKind::Ptr(mut_ty) if matches!(mut_ty.ty.kind, TyKind::Infer) => Cow::Borrowed(""), + _ => Cow::Owned(format!("::<{}>", to_pointee_ty)), + }; + span_lint_and_sugg( + cx, + PTR_AS_PTR, + expr.span, + "`as` casting between raw pointers without changing its mutability", + "try `pointer::cast`, a safer alternative", + format!("{}.cast{}()", cast_expr_sugg.maybe_par(), turbofish), + applicability, + ); + } + } + } + + extract_msrv_attr!(LateContext); +} diff --git a/clippy_lints/src/unnecessary_sort_by.rs b/clippy_lints/src/unnecessary_sort_by.rs index 0bccfc15678..9b45d38afd4 100644 --- a/clippy_lints/src/unnecessary_sort_by.rs +++ b/clippy_lints/src/unnecessary_sort_by.rs @@ -183,7 +183,7 @@ fn detect_lint(cx: &LateContext<'_>, expr: &Expr<'_>) -> Option<LintTrigger> { Param { pat: Pat { kind: PatKind::Binding(_, _, right_ident, _), .. }, .. } ] = &closure_body.params; if let ExprKind::MethodCall(method_path, _, [ref left_expr, ref right_expr], _) = &closure_body.value.kind; - if method_path.ident.name.to_ident_string() == "cmp"; + if method_path.ident.name == sym::cmp; then { let (closure_body, closure_arg, reverse) = if mirrored_exprs( &cx, diff --git a/clippy_lints/src/unnecessary_wraps.rs b/clippy_lints/src/unnecessary_wraps.rs index 07cd752184b..8ac5dd696b7 100644 --- a/clippy_lints/src/unnecessary_wraps.rs +++ b/clippy_lints/src/unnecessary_wraps.rs @@ -5,7 +5,7 @@ use crate::utils::{ use if_chain::if_chain; use rustc_errors::Applicability; use rustc_hir::intravisit::FnKind; -use rustc_hir::{Body, ExprKind, FnDecl, HirId, ItemKind, Impl, Node}; +use rustc_hir::{Body, ExprKind, FnDecl, HirId, Impl, ItemKind, Node}; use rustc_lint::{LateContext, LateLintPass}; use rustc_middle::ty::subst::GenericArgKind; use rustc_session::{declare_lint_pass, declare_tool_lint}; diff --git a/clippy_lints/src/unused_self.rs b/clippy_lints/src/unused_self.rs index a6171794311..5349c4f7eb8 100644 --- a/clippy_lints/src/unused_self.rs +++ b/clippy_lints/src/unused_self.rs @@ -1,7 +1,7 @@ use if_chain::if_chain; use rustc_hir::def::Res; use rustc_hir::intravisit::{walk_path, NestedVisitorMap, Visitor}; -use rustc_hir::{HirId, ImplItem, ImplItemKind, ItemKind, Impl, Path}; +use rustc_hir::{HirId, Impl, ImplItem, ImplItemKind, ItemKind, Path}; use rustc_lint::{LateContext, LateLintPass}; use rustc_middle::hir::map::Map; use rustc_session::{declare_lint_pass, declare_tool_lint}; diff --git a/clippy_lints/src/unwrap.rs b/clippy_lints/src/unwrap.rs index 6a87f534369..b82909eaea6 100644 --- a/clippy_lints/src/unwrap.rs +++ b/clippy_lints/src/unwrap.rs @@ -1,6 +1,5 @@ use crate::utils::{ - differing_macro_contexts, is_type_diagnostic_item, span_lint_and_then, - usage::is_potentially_mutated, + differing_macro_contexts, is_type_diagnostic_item, span_lint_and_then, usage::is_potentially_mutated, }; use if_chain::if_chain; use rustc_hir::intravisit::{walk_expr, walk_fn, FnKind, NestedVisitorMap, Visitor}; diff --git a/clippy_lints/src/use_self.rs b/clippy_lints/src/use_self.rs index b82ea66190f..72d1ca73929 100644 --- a/clippy_lints/src/use_self.rs +++ b/clippy_lints/src/use_self.rs @@ -28,8 +28,8 @@ declare_clippy_lint! { /// feels inconsistent. /// /// **Known problems:** - /// - False positive when using associated types (#2843) - /// - False positives in some situations when using generics (#3410) + /// - False positive when using associated types ([#2843](https://github.com/rust-lang/rust-clippy/issues/2843)) + /// - False positives in some situations when using generics ([#3410](https://github.com/rust-lang/rust-clippy/issues/3410)) /// /// **Example:** /// ```rust diff --git a/clippy_lints/src/useless_conversion.rs b/clippy_lints/src/useless_conversion.rs index efa9c3fab4a..c5334853986 100644 --- a/clippy_lints/src/useless_conversion.rs +++ b/clippy_lints/src/useless_conversion.rs @@ -80,10 +80,10 @@ impl<'tcx> LateLintPass<'tcx> for UselessConversion { ); } } - if match_trait_method(cx, e, &paths::INTO_ITERATOR) && &*name.ident.as_str() == "into_iter" { + if match_trait_method(cx, e, &paths::INTO_ITERATOR) && name.ident.name == sym::into_iter { if let Some(parent_expr) = get_parent_expr(cx, e) { if let ExprKind::MethodCall(ref parent_name, ..) = parent_expr.kind { - if &*parent_name.ident.as_str() != "into_iter" { + if parent_name.ident.name != sym::into_iter { return; } } diff --git a/clippy_lints/src/utils/attrs.rs b/clippy_lints/src/utils/attrs.rs index 24052a243af..8d28421d70d 100644 --- a/clippy_lints/src/utils/attrs.rs +++ b/clippy_lints/src/utils/attrs.rs @@ -1,6 +1,7 @@ use rustc_ast::ast; use rustc_errors::Applicability; use rustc_session::Session; +use rustc_span::sym; use std::str::FromStr; /// Deprecation status of attributes known by Clippy. @@ -64,11 +65,11 @@ pub fn get_attr<'a>( return false; }; let attr_segments = &attr.path.segments; - if attr_segments.len() == 2 && attr_segments[0].ident.to_string() == "clippy" { + if attr_segments.len() == 2 && attr_segments[0].ident.name == sym::clippy { BUILTIN_ATTRIBUTES .iter() - .find_map(|(builtin_name, deprecation_status)| { - if *builtin_name == attr_segments[1].ident.to_string() { + .find_map(|&(builtin_name, ref deprecation_status)| { + if attr_segments[1].ident.name.as_str() == builtin_name { Some(deprecation_status) } else { None @@ -99,7 +100,7 @@ pub fn get_attr<'a>( }, DeprecationStatus::None => { diag.cancel(); - attr_segments[1].ident.to_string() == name + attr_segments[1].ident.name.as_str() == name }, } }, diff --git a/clippy_lints/src/utils/hir_utils.rs b/clippy_lints/src/utils/hir_utils.rs index 062df68c0a4..10120a8805d 100644 --- a/clippy_lints/src/utils/hir_utils.rs +++ b/clippy_lints/src/utils/hir_utils.rs @@ -86,7 +86,7 @@ impl<'a, 'tcx> SpanlessEq<'a, 'tcx> { lb == rb && l_mut == r_mut && self.eq_expr(le, re) }, (&ExprKind::Continue(li), &ExprKind::Continue(ri)) => { - both(&li.label, &ri.label, |l, r| l.ident.as_str() == r.ident.as_str()) + both(&li.label, &ri.label, |l, r| l.ident.name == r.ident.name) }, (&ExprKind::Assign(ref ll, ref lr, _), &ExprKind::Assign(ref rl, ref rr, _)) => { self.allow_side_effects && self.eq_expr(ll, rl) && self.eq_expr(lr, rr) @@ -102,7 +102,7 @@ impl<'a, 'tcx> SpanlessEq<'a, 'tcx> { }) }, (&ExprKind::Break(li, ref le), &ExprKind::Break(ri, ref re)) => { - both(&li.label, &ri.label, |l, r| l.ident.as_str() == r.ident.as_str()) + both(&li.label, &ri.label, |l, r| l.ident.name == r.ident.name) && both(le, re, |l, r| self.eq_expr(l, r)) }, (&ExprKind::Box(ref l), &ExprKind::Box(ref r)) => self.eq_expr(l, r), @@ -124,7 +124,7 @@ impl<'a, 'tcx> SpanlessEq<'a, 'tcx> { }, (&ExprKind::Lit(ref l), &ExprKind::Lit(ref r)) => l.node == r.node, (&ExprKind::Loop(ref lb, ref ll, ref lls), &ExprKind::Loop(ref rb, ref rl, ref rls)) => { - lls == rls && self.eq_block(lb, rb) && both(ll, rl, |l, r| l.ident.as_str() == r.ident.as_str()) + lls == rls && self.eq_block(lb, rb) && both(ll, rl, |l, r| l.ident.name == r.ident.name) }, (&ExprKind::Match(ref le, ref la, ref ls), &ExprKind::Match(ref re, ref ra, ref rs)) => { ls == rs @@ -191,7 +191,7 @@ impl<'a, 'tcx> SpanlessEq<'a, 'tcx> { pub fn eq_fieldpat(&mut self, left: &FieldPat<'_>, right: &FieldPat<'_>) -> bool { let (FieldPat { ident: li, pat: lp, .. }, FieldPat { ident: ri, pat: rp, .. }) = (&left, &right); - li.name.as_str() == ri.name.as_str() && self.eq_pat(lp, rp) + li.name == ri.name && self.eq_pat(lp, rp) } /// Checks whether two patterns are the same. @@ -205,7 +205,7 @@ impl<'a, 'tcx> SpanlessEq<'a, 'tcx> { self.eq_qpath(lp, rp) && over(la, ra, |l, r| self.eq_pat(l, r)) && ls == rs }, (&PatKind::Binding(ref lb, .., ref li, ref lp), &PatKind::Binding(ref rb, .., ref ri, ref rp)) => { - lb == rb && li.name.as_str() == ri.name.as_str() && both(lp, rp, |l, r| self.eq_pat(l, r)) + lb == rb && li.name == ri.name && both(lp, rp, |l, r| self.eq_pat(l, r)) }, (&PatKind::Path(ref l), &PatKind::Path(ref r)) => self.eq_qpath(l, r), (&PatKind::Lit(ref l), &PatKind::Lit(ref r)) => self.eq_expr(l, r), @@ -266,8 +266,7 @@ impl<'a, 'tcx> SpanlessEq<'a, 'tcx> { pub fn eq_path_segment(&mut self, left: &PathSegment<'_>, right: &PathSegment<'_>) -> bool { // The == of idents doesn't work with different contexts, // we have to be explicit about hygiene - left.ident.as_str() == right.ident.as_str() - && both(&left.args, &right.args, |l, r| self.eq_path_parameters(l, r)) + left.ident.name == right.ident.name && both(&left.args, &right.args, |l, r| self.eq_path_parameters(l, r)) } pub fn eq_ty(&mut self, left: &Ty<'_>, right: &Ty<'_>) -> bool { diff --git a/clippy_lints/src/utils/internal_lints.rs b/clippy_lints/src/utils/internal_lints.rs index 407f06f4894..7aa17520ba7 100644 --- a/clippy_lints/src/utils/internal_lints.rs +++ b/clippy_lints/src/utils/internal_lints.rs @@ -10,9 +10,12 @@ use rustc_data_structures::fx::{FxHashMap, FxHashSet}; use rustc_errors::Applicability; use rustc_hir as hir; use rustc_hir::def::{DefKind, Res}; +use rustc_hir::def_id::DefId; use rustc_hir::hir_id::CRATE_HIR_ID; use rustc_hir::intravisit::{NestedVisitorMap, Visitor}; -use rustc_hir::{Crate, Expr, ExprKind, HirId, Item, MutTy, Mutability, Node, Path, StmtKind, Ty, TyKind}; +use rustc_hir::{ + BinOpKind, Crate, Expr, ExprKind, HirId, Item, MutTy, Mutability, Node, Path, StmtKind, Ty, TyKind, UnOp, +}; use rustc_lint::{EarlyContext, EarlyLintPass, LateContext, LateLintPass}; use rustc_middle::hir::map::Map; use rustc_middle::mir::interpret::ConstValue; @@ -272,6 +275,28 @@ declare_clippy_lint! { "interning a symbol that is pre-interned and defined as a constant" } +declare_clippy_lint! { + /// **What it does:** Checks for unnecessary conversion from Symbol to a string. + /// + /// **Why is this bad?** It's faster use symbols directly intead of strings. + /// + /// **Known problems:** None. + /// + /// **Example:** + /// Bad: + /// ```rust,ignore + /// symbol.as_str() == "clippy"; + /// ``` + /// + /// Good: + /// ```rust,ignore + /// symbol == sym::clippy; + /// ``` + pub UNNECESSARY_SYMBOL_STR, + internal, + "unnecessary conversion between Symbol and string" +} + declare_lint_pass!(ClippyLintsInternal => [CLIPPY_LINTS_INTERNAL]); impl EarlyLintPass for ClippyLintsInternal { @@ -868,11 +893,11 @@ impl<'tcx> LateLintPass<'tcx> for InvalidPaths { #[derive(Default)] pub struct InterningDefinedSymbol { - // Maps the symbol value to the constant name. - symbol_map: FxHashMap<u32, String>, + // Maps the symbol value to the constant DefId. + symbol_map: FxHashMap<u32, DefId>, } -impl_lint_pass!(InterningDefinedSymbol => [INTERNING_DEFINED_SYMBOL]); +impl_lint_pass!(InterningDefinedSymbol => [INTERNING_DEFINED_SYMBOL, UNNECESSARY_SYMBOL_STR]); impl<'tcx> LateLintPass<'tcx> for InterningDefinedSymbol { fn check_crate(&mut self, cx: &LateContext<'_>, _: &Crate<'_>) { @@ -880,16 +905,18 @@ impl<'tcx> LateLintPass<'tcx> for InterningDefinedSymbol { return; } - if let Some(Res::Def(_, def_id)) = path_to_res(cx, &paths::SYM_MODULE) { - for item in cx.tcx.item_children(def_id).iter() { - if_chain! { - if let Res::Def(DefKind::Const, item_def_id) = item.res; - let ty = cx.tcx.type_of(item_def_id); - if match_type(cx, ty, &paths::SYMBOL); - if let Ok(ConstValue::Scalar(value)) = cx.tcx.const_eval_poly(item_def_id); - if let Ok(value) = value.to_u32(); - then { - self.symbol_map.insert(value, item.ident.to_string()); + for &module in &[&paths::KW_MODULE, &paths::SYM_MODULE] { + if let Some(Res::Def(_, def_id)) = path_to_res(cx, module) { + for item in cx.tcx.item_children(def_id).iter() { + if_chain! { + if let Res::Def(DefKind::Const, item_def_id) = item.res; + let ty = cx.tcx.type_of(item_def_id); + if match_type(cx, ty, &paths::SYMBOL); + if let Ok(ConstValue::Scalar(value)) = cx.tcx.const_eval_poly(item_def_id); + if let Ok(value) = value.to_u32(); + then { + self.symbol_map.insert(value, item_def_id); + } } } } @@ -903,7 +930,7 @@ impl<'tcx> LateLintPass<'tcx> for InterningDefinedSymbol { if match_def_path(cx, *def_id, &paths::SYMBOL_INTERN); if let Some(Constant::Str(arg)) = constant_simple(cx, cx.typeck_results(), arg); let value = Symbol::intern(&arg).as_u32(); - if let Some(symbol_const) = self.symbol_map.get(&value); + if let Some(&def_id) = self.symbol_map.get(&value); then { span_lint_and_sugg( cx, @@ -911,10 +938,135 @@ impl<'tcx> LateLintPass<'tcx> for InterningDefinedSymbol { is_expn_of(expr.span, "sym").unwrap_or(expr.span), "interning a defined symbol", "try", - format!("rustc_span::symbol::sym::{}", symbol_const), + cx.tcx.def_path_str(def_id), Applicability::MachineApplicable, ); } } + if let ExprKind::Binary(op, left, right) = expr.kind { + if matches!(op.node, BinOpKind::Eq | BinOpKind::Ne) { + let data = [ + (left, self.symbol_str_expr(left, cx)), + (right, self.symbol_str_expr(right, cx)), + ]; + match data { + // both operands are a symbol string + [(_, Some(left)), (_, Some(right))] => { + span_lint_and_sugg( + cx, + UNNECESSARY_SYMBOL_STR, + expr.span, + "unnecessary `Symbol` to string conversion", + "try", + format!( + "{} {} {}", + left.as_symbol_snippet(cx), + op.node.as_str(), + right.as_symbol_snippet(cx), + ), + Applicability::MachineApplicable, + ); + }, + // one of the operands is a symbol string + [(expr, Some(symbol)), _] | [_, (expr, Some(symbol))] => { + // creating an owned string for comparison + if matches!(symbol, SymbolStrExpr::Expr { is_to_owned: true, .. }) { + span_lint_and_sugg( + cx, + UNNECESSARY_SYMBOL_STR, + expr.span, + "unnecessary string allocation", + "try", + format!("{}.as_str()", symbol.as_symbol_snippet(cx)), + Applicability::MachineApplicable, + ); + } + }, + // nothing found + [(_, None), (_, None)] => {}, + } + } + } + } +} + +impl InterningDefinedSymbol { + fn symbol_str_expr<'tcx>(&self, expr: &'tcx Expr<'tcx>, cx: &LateContext<'tcx>) -> Option<SymbolStrExpr<'tcx>> { + static IDENT_STR_PATHS: &[&[&str]] = &[&paths::IDENT_AS_STR, &paths::TO_STRING_METHOD]; + static SYMBOL_STR_PATHS: &[&[&str]] = &[ + &paths::SYMBOL_AS_STR, + &paths::SYMBOL_TO_IDENT_STRING, + &paths::TO_STRING_METHOD, + ]; + // SymbolStr might be de-referenced: `&*symbol.as_str()` + let call = if_chain! { + if let ExprKind::AddrOf(_, _, e) = expr.kind; + if let ExprKind::Unary(UnOp::UnDeref, e) = e.kind; + then { e } else { expr } + }; + if_chain! { + // is a method call + if let ExprKind::MethodCall(_, _, [item], _) = call.kind; + if let Some(did) = cx.typeck_results().type_dependent_def_id(call.hir_id); + let ty = cx.typeck_results().expr_ty(item); + // ...on either an Ident or a Symbol + if let Some(is_ident) = if match_type(cx, ty, &paths::SYMBOL) { + Some(false) + } else if match_type(cx, ty, &paths::IDENT) { + Some(true) + } else { + None + }; + // ...which converts it to a string + let paths = if is_ident { IDENT_STR_PATHS } else { SYMBOL_STR_PATHS }; + if let Some(path) = paths.iter().find(|path| match_def_path(cx, did, path)); + then { + let is_to_owned = path.last().unwrap().ends_with("string"); + return Some(SymbolStrExpr::Expr { + item, + is_ident, + is_to_owned, + }); + } + } + // is a string constant + if let Some(Constant::Str(s)) = constant_simple(cx, cx.typeck_results(), expr) { + let value = Symbol::intern(&s).as_u32(); + // ...which matches a symbol constant + if let Some(&def_id) = self.symbol_map.get(&value) { + return Some(SymbolStrExpr::Const(def_id)); + } + } + None + } +} + +enum SymbolStrExpr<'tcx> { + /// a string constant with a corresponding symbol constant + Const(DefId), + /// a "symbol to string" expression like `symbol.as_str()` + Expr { + /// part that evaluates to `Symbol` or `Ident` + item: &'tcx Expr<'tcx>, + is_ident: bool, + /// whether an owned `String` is created like `to_ident_string()` + is_to_owned: bool, + }, +} + +impl<'tcx> SymbolStrExpr<'tcx> { + /// Returns a snippet that evaluates to a `Symbol` and is const if possible + fn as_symbol_snippet(&self, cx: &LateContext<'_>) -> Cow<'tcx, str> { + match *self { + Self::Const(def_id) => cx.tcx.def_path_str(def_id).into(), + Self::Expr { item, is_ident, .. } => { + let mut snip = snippet(cx, item.span.source_callsite(), ".."); + if is_ident { + // get `Ident.name` + snip.to_mut().push_str(".name"); + } + snip + }, + } } } diff --git a/clippy_lints/src/utils/mod.rs b/clippy_lints/src/utils/mod.rs index 4c707c4b904..9b262517a98 100644 --- a/clippy_lints/src/utils/mod.rs +++ b/clippy_lints/src/utils/mod.rs @@ -1,5 +1,5 @@ #[macro_use] -pub mod sym; +pub mod sym_helper; #[allow(clippy::module_name_repetitions)] pub mod ast_utils; @@ -56,8 +56,8 @@ use rustc_semver::RustcVersion; use rustc_session::Session; use rustc_span::hygiene::{ExpnKind, MacroKind}; use rustc_span::source_map::original_sp; -use rustc_span::sym as rustc_sym; -use rustc_span::symbol::{self, kw, Symbol}; +use rustc_span::sym; +use rustc_span::symbol::{kw, Symbol}; use rustc_span::{BytePos, Pos, Span, DUMMY_SP}; use rustc_target::abi::Integer; use rustc_trait_selection::traits::query::normalize::AtExt; @@ -1121,7 +1121,7 @@ pub fn is_refutable(cx: &LateContext<'_>, pat: &Pat<'_>) -> bool { /// Checks for the `#[automatically_derived]` attribute all `#[derive]`d /// implementations have. pub fn is_automatically_derived(attrs: &[ast::Attribute]) -> bool { - attrs.iter().any(|attr| attr.has_name(rustc_sym::automatically_derived)) + attrs.iter().any(|attr| attr.has_name(sym::automatically_derived)) } /// Remove blocks around an expression. @@ -1434,12 +1434,13 @@ pub fn parent_node_is_if_expr(expr: &Expr<'_>, cx: &LateContext<'_>) -> bool { let map = cx.tcx.hir(); let parent_id = map.get_parent_node(expr.hir_id); let parent_node = map.get(parent_id); - if let Node::Expr(Expr { kind: ExprKind::If(_, _, _), .. }) = parent_node { - true - } - else { - false - } + matches!( + parent_node, + Node::Expr(Expr { + kind: ExprKind::If(_, _, _), + .. + }) + ) } // Finds the attribute with the given name, if any @@ -1514,7 +1515,7 @@ pub fn is_must_use_func_call(cx: &LateContext<'_>, expr: &Expr<'_>) -> bool { pub fn is_no_std_crate(krate: &Crate<'_>) -> bool { krate.item.attrs.iter().any(|attr| { if let ast::AttrKind::Normal(ref attr, _) = attr.kind { - attr.path == symbol::sym::no_std + attr.path == sym::no_std } else { false } @@ -1686,6 +1687,18 @@ macro_rules! unwrap_cargo_metadata { }}; } +pub fn is_hir_ty_cfg_dependant(cx: &LateContext<'_>, ty: &hir::Ty<'_>) -> bool { + if_chain! { + if let TyKind::Path(QPath::Resolved(_, path)) = ty.kind; + if let Res::Def(_, def_id) = path.res; + then { + cx.tcx.has_attr(def_id, sym::cfg) || cx.tcx.has_attr(def_id, sym::cfg_attr) + } else { + false + } + } +} + #[cfg(test)] mod test { use super::{reindent_multiline, without_block_comments}; diff --git a/clippy_lints/src/utils/paths.rs b/clippy_lints/src/utils/paths.rs index 2080a49a11c..c0b203b5388 100644 --- a/clippy_lints/src/utils/paths.rs +++ b/clippy_lints/src/utils/paths.rs @@ -54,6 +54,10 @@ pub const HASH: [&str; 3] = ["core", "hash", "Hash"]; pub const HASHMAP: [&str; 5] = ["std", "collections", "hash", "map", "HashMap"]; pub const HASHMAP_ENTRY: [&str; 5] = ["std", "collections", "hash", "map", "Entry"]; pub const HASHSET: [&str; 5] = ["std", "collections", "hash", "set", "HashSet"]; +#[cfg(feature = "internal-lints")] +pub const IDENT: [&str; 3] = ["rustc_span", "symbol", "Ident"]; +#[cfg(feature = "internal-lints")] +pub const IDENT_AS_STR: [&str; 4] = ["rustc_span", "symbol", "Ident", "as_str"]; pub const INDEX: [&str; 3] = ["core", "ops", "Index"]; pub const INDEX_MUT: [&str; 3] = ["core", "ops", "IndexMut"]; pub const INSERT_STR: [&str; 4] = ["alloc", "string", "String", "insert_str"]; @@ -65,6 +69,8 @@ pub const IPADDR_V4: [&str; 4] = ["std", "net", "IpAddr", "V4"]; pub const IPADDR_V6: [&str; 4] = ["std", "net", "IpAddr", "V6"]; pub const ITERATOR: [&str; 5] = ["core", "iter", "traits", "iterator", "Iterator"]; #[cfg(feature = "internal-lints")] +pub const KW_MODULE: [&str; 3] = ["rustc_span", "symbol", "kw"]; +#[cfg(feature = "internal-lints")] pub const LATE_CONTEXT: [&str; 2] = ["rustc_lint", "LateContext"]; pub const LINKED_LIST: [&str; 4] = ["alloc", "collections", "linked_list", "LinkedList"]; #[cfg(feature = "internal-lints")] @@ -148,8 +154,12 @@ pub const STR_STARTS_WITH: [&str; 4] = ["core", "str", "<impl str>", "starts_wit #[cfg(feature = "internal-lints")] pub const SYMBOL: [&str; 3] = ["rustc_span", "symbol", "Symbol"]; #[cfg(feature = "internal-lints")] +pub const SYMBOL_AS_STR: [&str; 4] = ["rustc_span", "symbol", "Symbol", "as_str"]; +#[cfg(feature = "internal-lints")] pub const SYMBOL_INTERN: [&str; 4] = ["rustc_span", "symbol", "Symbol", "intern"]; #[cfg(feature = "internal-lints")] +pub const SYMBOL_TO_IDENT_STRING: [&str; 4] = ["rustc_span", "symbol", "Symbol", "to_ident_string"]; +#[cfg(feature = "internal-lints")] pub const SYM_MODULE: [&str; 3] = ["rustc_span", "symbol", "sym"]; #[cfg(feature = "internal-lints")] pub const SYNTAX_CONTEXT: [&str; 3] = ["rustc_span", "hygiene", "SyntaxContext"]; diff --git a/clippy_lints/src/utils/sym.rs b/clippy_lints/src/utils/sym_helper.rs index 273288c3d52..f47dc80ebad 100644 --- a/clippy_lints/src/utils/sym.rs +++ b/clippy_lints/src/utils/sym_helper.rs @@ -1,4 +1,5 @@ #[macro_export] +/// Convenience wrapper around rustc's `Symbol::intern` macro_rules! sym { ($tt:tt) => { rustc_span::symbol::Symbol::intern(stringify!($tt)) diff --git a/clippy_lints/src/utils/visitors.rs b/clippy_lints/src/utils/visitors.rs index b769a18802b..ebf69df31ca 100644 --- a/clippy_lints/src/utils/visitors.rs +++ b/clippy_lints/src/utils/visitors.rs @@ -107,7 +107,7 @@ where if let Some(el) = else_opt { self.visit_expr(el); } - } + }, hir::ExprKind::Match(cond, arms, _) => { self.inside_stmt(true).visit_expr(cond); for arm in arms { diff --git a/clippy_lints/src/vec_init_then_push.rs b/clippy_lints/src/vec_init_then_push.rs new file mode 100644 index 00000000000..e632a7e57ee --- /dev/null +++ b/clippy_lints/src/vec_init_then_push.rs @@ -0,0 +1,187 @@ +use crate::utils::{is_type_diagnostic_item, match_def_path, paths, snippet, span_lint_and_sugg}; +use if_chain::if_chain; +use rustc_ast::ast::LitKind; +use rustc_errors::Applicability; +use rustc_hir::{BindingAnnotation, Block, Expr, ExprKind, Local, PatKind, QPath, Stmt, StmtKind}; +use rustc_lint::{LateContext, LateLintPass, LintContext}; +use rustc_middle::lint::in_external_macro; +use rustc_session::{declare_tool_lint, impl_lint_pass}; +use rustc_span::{symbol::sym, Span, Symbol}; +use std::convert::TryInto; + +declare_clippy_lint! { + /// **What it does:** Checks for calls to `push` immediately after creating a new `Vec`. + /// + /// **Why is this bad?** The `vec![]` macro is both more performant and easier to read than + /// multiple `push` calls. + /// + /// **Known problems:** None. + /// + /// **Example:** + /// + /// ```rust + /// let mut v = Vec::new(); + /// v.push(0); + /// ``` + /// Use instead: + /// ```rust + /// let v = vec![0]; + /// ``` + pub VEC_INIT_THEN_PUSH, + perf, + "`push` immediately after `Vec` creation" +} + +impl_lint_pass!(VecInitThenPush => [VEC_INIT_THEN_PUSH]); + +#[derive(Default)] +pub struct VecInitThenPush { + searcher: Option<VecPushSearcher>, +} + +#[derive(Clone, Copy)] +enum VecInitKind { + New, + WithCapacity(u64), +} +struct VecPushSearcher { + init: VecInitKind, + name: Symbol, + lhs_is_local: bool, + lhs_span: Span, + err_span: Span, + found: u64, +} +impl VecPushSearcher { + fn display_err(&self, cx: &LateContext<'_>) { + match self.init { + _ if self.found == 0 => return, + VecInitKind::WithCapacity(x) if x > self.found => return, + _ => (), + }; + + let mut s = if self.lhs_is_local { + String::from("let ") + } else { + String::new() + }; + s.push_str(&snippet(cx, self.lhs_span, "..")); + s.push_str(" = vec![..];"); + + span_lint_and_sugg( + cx, + VEC_INIT_THEN_PUSH, + self.err_span, + "calls to `push` immediately after creation", + "consider using the `vec![]` macro", + s, + Applicability::HasPlaceholders, + ); + } +} + +impl LateLintPass<'_> for VecInitThenPush { + fn check_local(&mut self, cx: &LateContext<'tcx>, local: &'tcx Local<'tcx>) { + self.searcher = None; + if_chain! { + if !in_external_macro(cx.sess(), local.span); + if let Some(init) = local.init; + if let PatKind::Binding(BindingAnnotation::Mutable, _, ident, None) = local.pat.kind; + if let Some(init_kind) = get_vec_init_kind(cx, init); + then { + self.searcher = Some(VecPushSearcher { + init: init_kind, + name: ident.name, + lhs_is_local: true, + lhs_span: local.ty.map_or(local.pat.span, |t| local.pat.span.to(t.span)), + err_span: local.span, + found: 0, + }); + } + } + } + + fn check_expr(&mut self, cx: &LateContext<'tcx>, expr: &'tcx Expr<'_>) { + if self.searcher.is_none() { + if_chain! { + if !in_external_macro(cx.sess(), expr.span); + if let ExprKind::Assign(left, right, _) = expr.kind; + if let ExprKind::Path(QPath::Resolved(_, path)) = left.kind; + if let Some(name) = path.segments.get(0); + if let Some(init_kind) = get_vec_init_kind(cx, right); + then { + self.searcher = Some(VecPushSearcher { + init: init_kind, + name: name.ident.name, + lhs_is_local: false, + lhs_span: left.span, + err_span: expr.span, + found: 0, + }); + } + } + } + } + + fn check_stmt(&mut self, cx: &LateContext<'tcx>, stmt: &'tcx Stmt<'_>) { + if let Some(searcher) = self.searcher.take() { + if_chain! { + if let StmtKind::Expr(expr) | StmtKind::Semi(expr) = stmt.kind; + if let ExprKind::MethodCall(path, _, [self_arg, _], _) = expr.kind; + if path.ident.name.as_str() == "push"; + if let ExprKind::Path(QPath::Resolved(_, self_path)) = self_arg.kind; + if let [self_name] = self_path.segments; + if self_name.ident.name == searcher.name; + then { + self.searcher = Some(VecPushSearcher { + found: searcher.found + 1, + err_span: searcher.err_span.to(stmt.span), + .. searcher + }); + } else { + searcher.display_err(cx); + } + } + } + } + + fn check_block_post(&mut self, cx: &LateContext<'tcx>, _: &'tcx Block<'tcx>) { + if let Some(searcher) = self.searcher.take() { + searcher.display_err(cx); + } + } +} + +fn get_vec_init_kind<'tcx>(cx: &LateContext<'tcx>, expr: &'tcx Expr<'tcx>) -> Option<VecInitKind> { + if let ExprKind::Call(func, args) = expr.kind { + match func.kind { + ExprKind::Path(QPath::TypeRelative(ty, name)) + if is_type_diagnostic_item(cx, cx.typeck_results().node_type(ty.hir_id), sym::vec_type) => + { + if name.ident.name == sym::new { + return Some(VecInitKind::New); + } else if name.ident.name.as_str() == "with_capacity" { + return args.get(0).and_then(|arg| { + if_chain! { + if let ExprKind::Lit(lit) = &arg.kind; + if let LitKind::Int(num, _) = lit.node; + then { + Some(VecInitKind::WithCapacity(num.try_into().ok()?)) + } else { + None + } + } + }); + } + } + ExprKind::Path(QPath::Resolved(_, path)) + if match_def_path(cx, path.res.opt_def_id()?, &paths::DEFAULT_TRAIT_METHOD) + && is_type_diagnostic_item(cx, cx.typeck_results().expr_ty(expr), sym::vec_type) => + { + return Some(VecInitKind::New); + } + _ => (), + } + } + None +} diff --git a/clippy_lints/src/wildcard_imports.rs b/clippy_lints/src/wildcard_imports.rs index 5683a71efea..10005a7fc81 100644 --- a/clippy_lints/src/wildcard_imports.rs +++ b/clippy_lints/src/wildcard_imports.rs @@ -7,7 +7,8 @@ use rustc_hir::{ }; use rustc_lint::{LateContext, LateLintPass}; use rustc_session::{declare_tool_lint, impl_lint_pass}; -use rustc_span::BytePos; +use rustc_span::symbol::kw; +use rustc_span::{sym, BytePos}; declare_clippy_lint! { /// **What it does:** Checks for `use Enum::*`. @@ -198,12 +199,12 @@ impl WildcardImports { // Allow "...prelude::..::*" imports. // Many crates have a prelude, and it is imported as a glob by design. fn is_prelude_import(segments: &[PathSegment<'_>]) -> bool { - segments.iter().any(|ps| ps.ident.as_str() == "prelude") + segments.iter().any(|ps| ps.ident.name == sym::prelude) } // Allow "super::*" imports in tests. fn is_super_only_import(segments: &[PathSegment<'_>]) -> bool { - segments.len() == 1 && segments[0].ident.as_str() == "super" + segments.len() == 1 && segments[0].ident.name == kw::Super } fn is_test_module_or_function(item: &Item<'_>) -> bool { diff --git a/clippy_lints/src/write.rs b/clippy_lints/src/write.rs index 337f7a229b9..af324f831df 100644 --- a/clippy_lints/src/write.rs +++ b/clippy_lints/src/write.rs @@ -10,7 +10,8 @@ use rustc_lexer::unescape::{self, EscapeError}; use rustc_lint::{EarlyContext, EarlyLintPass}; use rustc_parse::parser; use rustc_session::{declare_tool_lint, impl_lint_pass}; -use rustc_span::{sym, BytePos, Span, Symbol}; +use rustc_span::symbol::kw; +use rustc_span::{sym, BytePos, Span}; declare_clippy_lint! { /// **What it does:** This lint warns when you use `println!("")` to @@ -301,7 +302,7 @@ impl EarlyLintPass for Write { } } else if mac.path == sym!(writeln) { if let (Some(fmt_str), expr) = self.check_tts(cx, mac.args.inner_tokens(), true) { - if fmt_str.symbol == Symbol::intern("") { + if fmt_str.symbol == kw::Empty { let mut applicability = Applicability::MachineApplicable; // FIXME: remove this `#[allow(...)]` once the issue #5822 gets fixed #[allow(clippy::option_if_let_else)] @@ -484,7 +485,7 @@ impl Write { fn lint_println_empty_string(&self, cx: &EarlyContext<'_>, mac: &MacCall) { if let (Some(fmt_str), _) = self.check_tts(cx, mac.args.inner_tokens(), false) { - if fmt_str.symbol == Symbol::intern("") { + if fmt_str.symbol == kw::Empty { let name = mac.path.segments[0].ident.name; span_lint_and_sugg( cx, |