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| author | flip1995 <philipp.krones@embecosm.com> | 2021-02-11 15:04:38 +0100 |
|---|---|---|
| committer | flip1995 <philipp.krones@embecosm.com> | 2021-02-11 15:04:38 +0100 |
| commit | d2e2f64ef7bd98c8ce2c9ce77db27ea1617892ea (patch) | |
| tree | a2147c3fa0e7a643165c22eb8a53a680d8da736a /src/tools/clippy/clippy_lints | |
| parent | 2918062d1d94b65dfd53d265e957d86fcb8bfdbd (diff) | |
| parent | 70c0f90453701e7d6d9b99aaa1fc6a765937b736 (diff) | |
| download | rust-d2e2f64ef7bd98c8ce2c9ce77db27ea1617892ea.tar.gz rust-d2e2f64ef7bd98c8ce2c9ce77db27ea1617892ea.zip | |
Merge commit '70c0f90453701e7d6d9b99aaa1fc6a765937b736' into clippyup
Diffstat (limited to 'src/tools/clippy/clippy_lints')
31 files changed, 719 insertions, 464 deletions
diff --git a/src/tools/clippy/clippy_lints/src/cargo_common_metadata.rs b/src/tools/clippy/clippy_lints/src/cargo_common_metadata.rs index 0d294761af5..cc2869ab495 100644 --- a/src/tools/clippy/clippy_lints/src/cargo_common_metadata.rs +++ b/src/tools/clippy/clippy_lints/src/cargo_common_metadata.rs @@ -5,7 +5,7 @@ use std::path::PathBuf; use crate::utils::{run_lints, span_lint}; use rustc_hir::{hir_id::CRATE_HIR_ID, Crate}; use rustc_lint::{LateContext, LateLintPass}; -use rustc_session::{declare_lint_pass, declare_tool_lint}; +use rustc_session::{declare_tool_lint, impl_lint_pass}; use rustc_span::source_map::DUMMY_SP; declare_clippy_lint! { @@ -51,6 +51,21 @@ declare_clippy_lint! { "common metadata is defined in `Cargo.toml`" } +#[derive(Copy, Clone, Debug)] +pub struct CargoCommonMetadata { + ignore_publish: bool, +} + +impl CargoCommonMetadata { + pub fn new(ignore_publish: bool) -> Self { + Self { ignore_publish } + } +} + +impl_lint_pass!(CargoCommonMetadata => [ + CARGO_COMMON_METADATA +]); + fn missing_warning(cx: &LateContext<'_>, package: &cargo_metadata::Package, field: &str) { let message = format!("package `{}` is missing `{}` metadata", package.name, field); span_lint(cx, CARGO_COMMON_METADATA, DUMMY_SP, &message); @@ -69,8 +84,6 @@ fn is_empty_vec(value: &[String]) -> bool { value.iter().all(String::is_empty) } -declare_lint_pass!(CargoCommonMetadata => [CARGO_COMMON_METADATA]); - impl LateLintPass<'_> for CargoCommonMetadata { fn check_crate(&mut self, cx: &LateContext<'_>, _: &Crate<'_>) { if !run_lints(cx, &[CARGO_COMMON_METADATA], CRATE_HIR_ID) { @@ -80,32 +93,36 @@ impl LateLintPass<'_> for CargoCommonMetadata { let metadata = unwrap_cargo_metadata!(cx, CARGO_COMMON_METADATA, false); for package in metadata.packages { - if is_empty_vec(&package.authors) { - missing_warning(cx, &package, "package.authors"); - } - - if is_empty_str(&package.description) { - missing_warning(cx, &package, "package.description"); - } - - if is_empty_str(&package.license) && is_empty_path(&package.license_file) { - missing_warning(cx, &package, "either package.license or package.license_file"); - } - - if is_empty_str(&package.repository) { - missing_warning(cx, &package, "package.repository"); - } - - if is_empty_path(&package.readme) { - missing_warning(cx, &package, "package.readme"); - } - - if is_empty_vec(&package.keywords) { - missing_warning(cx, &package, "package.keywords"); - } - - if is_empty_vec(&package.categories) { - missing_warning(cx, &package, "package.categories"); + // only run the lint if publish is `None` (`publish = true` or skipped entirely) + // or if the vector isn't empty (`publish = ["something"]`) + if package.publish.as_ref().filter(|publish| publish.is_empty()).is_none() || self.ignore_publish { + if is_empty_vec(&package.authors) { + missing_warning(cx, &package, "package.authors"); + } + + if is_empty_str(&package.description) { + missing_warning(cx, &package, "package.description"); + } + + if is_empty_str(&package.license) && is_empty_path(&package.license_file) { + missing_warning(cx, &package, "either package.license or package.license_file"); + } + + if is_empty_str(&package.repository) { + missing_warning(cx, &package, "package.repository"); + } + + if is_empty_path(&package.readme) { + missing_warning(cx, &package, "package.readme"); + } + + if is_empty_vec(&package.keywords) { + missing_warning(cx, &package, "package.keywords"); + } + + if is_empty_vec(&package.categories) { + missing_warning(cx, &package, "package.categories"); + } } } } diff --git a/src/tools/clippy/clippy_lints/src/collapsible_match.rs b/src/tools/clippy/clippy_lints/src/collapsible_match.rs index b83aae0e571..67282cb7900 100644 --- a/src/tools/clippy/clippy_lints/src/collapsible_match.rs +++ b/src/tools/clippy/clippy_lints/src/collapsible_match.rs @@ -1,10 +1,10 @@ use crate::utils::visitors::LocalUsedVisitor; -use crate::utils::{span_lint_and_then, SpanlessEq}; +use crate::utils::{path_to_local, span_lint_and_then, SpanlessEq}; use if_chain::if_chain; use rustc_hir::def::{CtorKind, CtorOf, DefKind, Res}; use rustc_hir::{Arm, Expr, ExprKind, Guard, HirId, Pat, PatKind, QPath, StmtKind, UnOp}; use rustc_lint::{LateContext, LateLintPass}; -use rustc_middle::ty::{DefIdTree, TyCtxt}; +use rustc_middle::ty::{DefIdTree, TyCtxt, TypeckResults}; use rustc_session::{declare_lint_pass, declare_tool_lint}; use rustc_span::{MultiSpan, Span}; @@ -60,7 +60,7 @@ impl<'tcx> LateLintPass<'tcx> for CollapsibleMatch { } } -fn check_arm(arm: &Arm<'_>, wild_outer_arm: &Arm<'_>, cx: &LateContext<'_>) { +fn check_arm<'tcx>(arm: &Arm<'tcx>, wild_outer_arm: &Arm<'tcx>, cx: &LateContext<'tcx>) { if_chain! { let expr = strip_singleton_blocks(arm.body); if let ExprKind::Match(expr_in, arms_inner, _) = expr.kind; @@ -72,7 +72,7 @@ fn check_arm(arm: &Arm<'_>, wild_outer_arm: &Arm<'_>, cx: &LateContext<'_>) { if arms_inner.iter().all(|arm| arm.guard.is_none()); // match expression must be a local binding // match <local> { .. } - if let Some(binding_id) = addr_adjusted_binding(expr_in, cx); + if let Some(binding_id) = path_to_local(strip_ref_operators(expr_in, cx.typeck_results())); // one of the branches must be "wild-like" if let Some(wild_inner_arm_idx) = arms_inner.iter().rposition(|arm_inner| arm_is_wild_like(arm_inner, cx.tcx)); let (wild_inner_arm, non_wild_inner_arm) = @@ -84,14 +84,13 @@ fn check_arm(arm: &Arm<'_>, wild_outer_arm: &Arm<'_>, cx: &LateContext<'_>) { // the "wild-like" branches must be equal if SpanlessEq::new(cx).eq_expr(wild_inner_arm.body, wild_outer_arm.body); // the binding must not be used in the if guard + let mut used_visitor = LocalUsedVisitor::new(cx, binding_id); if match arm.guard { None => true, - Some(Guard::If(expr) | Guard::IfLet(_, expr)) => { - !LocalUsedVisitor::new(binding_id).check_expr(expr) - } + Some(Guard::If(expr) | Guard::IfLet(_, expr)) => !used_visitor.check_expr(expr), }; // ...or anywhere in the inner match - if !arms_inner.iter().any(|arm| LocalUsedVisitor::new(binding_id).check_arm(arm)); + if !arms_inner.iter().any(|arm| used_visitor.check_arm(arm)); then { span_lint_and_then( cx, @@ -175,19 +174,15 @@ fn is_none_ctor(res: Res, tcx: TyCtxt<'_>) -> bool { false } -/// Retrieves a binding ID with optional `&` and/or `*` operators removed. (e.g. `&**foo`) -/// Returns `None` if a non-reference type is de-referenced. -/// For example, if `Vec` is de-referenced to a slice, `None` is returned. -fn addr_adjusted_binding(mut expr: &Expr<'_>, cx: &LateContext<'_>) -> Option<HirId> { +/// Removes `AddrOf` operators (`&`) or deref operators (`*`), but only if a reference type is +/// dereferenced. An overloaded deref such as `Vec` to slice would not be removed. +fn strip_ref_operators<'hir>(mut expr: &'hir Expr<'hir>, typeck_results: &TypeckResults<'_>) -> &'hir Expr<'hir> { loop { match expr.kind { ExprKind::AddrOf(_, _, e) => expr = e, - ExprKind::Path(QPath::Resolved(None, path)) => match path.res { - Res::Local(binding_id) => break Some(binding_id), - _ => break None, - }, - ExprKind::Unary(UnOp::Deref, e) if cx.typeck_results().expr_ty(e).is_ref() => expr = e, - _ => break None, + ExprKind::Unary(UnOp::Deref, e) if typeck_results.expr_ty(e).is_ref() => expr = e, + _ => break, } } + expr } diff --git a/src/tools/clippy/clippy_lints/src/disallowed_method.rs b/src/tools/clippy/clippy_lints/src/disallowed_method.rs index 581c3242e37..56dc6d18a58 100644 --- a/src/tools/clippy/clippy_lints/src/disallowed_method.rs +++ b/src/tools/clippy/clippy_lints/src/disallowed_method.rs @@ -1,29 +1,47 @@ -use crate::utils::span_lint; +use crate::utils::{fn_def_id, span_lint}; use rustc_data_structures::fx::FxHashSet; -use rustc_hir::{Expr, ExprKind}; +use rustc_hir::Expr; use rustc_lint::{LateContext, LateLintPass}; use rustc_session::{declare_tool_lint, impl_lint_pass}; use rustc_span::Symbol; declare_clippy_lint! { - /// **What it does:** Lints for specific trait methods defined in clippy.toml + /// **What it does:** Denies the configured methods and functions in clippy.toml /// /// **Why is this bad?** Some methods are undesirable in certain contexts, - /// and it would be beneficial to lint for them as needed. + /// and it's beneficial to lint for them as needed. /// - /// **Known problems:** None. + /// **Known problems:** Currently, you must write each function as a + /// fully-qualified path. This lint doesn't support aliases or reexported + /// names; be aware that many types in `std` are actually reexports. + /// + /// For example, if you want to disallow `Duration::as_secs`, your clippy.toml + /// configuration would look like + /// `disallowed-methods = ["core::time::Duration::as_secs"]` and not + /// `disallowed-methods = ["std::time::Duration::as_secs"]` as you might expect. /// /// **Example:** /// + /// An example clippy.toml configuration: + /// ```toml + /// # clippy.toml + /// disallowed-methods = ["alloc::vec::Vec::leak", "std::time::Instant::now"] + /// ``` + /// /// ```rust,ignore - /// // example code where clippy issues a warning - /// foo.bad_method(); // Foo::bad_method is disallowed in the configuration + /// // Example code where clippy issues a warning + /// let xs = vec![1, 2, 3, 4]; + /// xs.leak(); // Vec::leak is disallowed in the config. + /// + /// let _now = Instant::now(); // Instant::now is disallowed in the config. /// ``` + /// /// Use instead: /// ```rust,ignore - /// // example code which does not raise clippy warning - /// goodStruct.bad_method(); // GoodStruct::bad_method is not disallowed + /// // Example code which does not raise clippy warning + /// let mut xs = Vec::new(); // Vec::new is _not_ disallowed in the config. + /// xs.push(123); // Vec::push is _not_ disallowed in the config. /// ``` pub DISALLOWED_METHOD, nursery, @@ -50,14 +68,12 @@ impl_lint_pass!(DisallowedMethod => [DISALLOWED_METHOD]); impl<'tcx> LateLintPass<'tcx> for DisallowedMethod { fn check_expr(&mut self, cx: &LateContext<'tcx>, expr: &'tcx Expr<'_>) { - if let ExprKind::MethodCall(_path, _, _args, _) = &expr.kind { - let def_id = cx.typeck_results().type_dependent_def_id(expr.hir_id).unwrap(); - - let method_call = cx.get_def_path(def_id); - if self.disallowed.contains(&method_call) { - let method = method_call - .iter() - .map(|s| s.to_ident_string()) + if let Some(def_id) = fn_def_id(cx, expr) { + let func_path = cx.get_def_path(def_id); + if self.disallowed.contains(&func_path) { + let func_path_string = func_path + .into_iter() + .map(Symbol::to_ident_string) .collect::<Vec<_>>() .join("::"); @@ -65,7 +81,7 @@ impl<'tcx> LateLintPass<'tcx> for DisallowedMethod { cx, DISALLOWED_METHOD, expr.span, - &format!("use of a disallowed method `{}`", method), + &format!("use of a disallowed method `{}`", func_path_string), ); } } diff --git a/src/tools/clippy/clippy_lints/src/eval_order_dependence.rs b/src/tools/clippy/clippy_lints/src/eval_order_dependence.rs index bc2b2904698..83cee11c3a8 100644 --- a/src/tools/clippy/clippy_lints/src/eval_order_dependence.rs +++ b/src/tools/clippy/clippy_lints/src/eval_order_dependence.rs @@ -1,7 +1,6 @@ -use crate::utils::{get_parent_expr, span_lint, span_lint_and_note}; -use if_chain::if_chain; +use crate::utils::{get_parent_expr, path_to_local, path_to_local_id, span_lint, span_lint_and_note}; use rustc_hir::intravisit::{walk_expr, NestedVisitorMap, Visitor}; -use rustc_hir::{def, BinOpKind, Block, Expr, ExprKind, Guard, HirId, Local, Node, QPath, Stmt, StmtKind}; +use rustc_hir::{BinOpKind, Block, Expr, ExprKind, Guard, HirId, Local, Node, Stmt, StmtKind}; use rustc_lint::{LateContext, LateLintPass}; use rustc_middle::hir::map::Map; use rustc_middle::ty; @@ -72,20 +71,14 @@ impl<'tcx> LateLintPass<'tcx> for EvalOrderDependence { // Find a write to a local variable. match expr.kind { ExprKind::Assign(ref lhs, ..) | ExprKind::AssignOp(_, ref lhs, _) => { - if let ExprKind::Path(ref qpath) = lhs.kind { - if let QPath::Resolved(_, ref path) = *qpath { - if path.segments.len() == 1 { - if let def::Res::Local(var) = cx.qpath_res(qpath, lhs.hir_id) { - let mut visitor = ReadVisitor { - cx, - var, - write_expr: expr, - last_expr: expr, - }; - check_for_unsequenced_reads(&mut visitor); - } - } - } + if let Some(var) = path_to_local(lhs) { + let mut visitor = ReadVisitor { + cx, + var, + write_expr: expr, + last_expr: expr, + }; + check_for_unsequenced_reads(&mut visitor); } }, _ => {}, @@ -304,27 +297,20 @@ impl<'a, 'tcx> Visitor<'tcx> for ReadVisitor<'a, 'tcx> { return; } - match expr.kind { - ExprKind::Path(ref qpath) => { - if_chain! { - if let QPath::Resolved(None, ref path) = *qpath; - if path.segments.len() == 1; - if let def::Res::Local(local_id) = self.cx.qpath_res(qpath, expr.hir_id); - if local_id == self.var; - // Check that this is a read, not a write. - if !is_in_assignment_position(self.cx, expr); - then { - span_lint_and_note( - self.cx, - EVAL_ORDER_DEPENDENCE, - expr.span, - "unsequenced read of a variable", - Some(self.write_expr.span), - "whether read occurs before this write depends on evaluation order" - ); - } - } + if path_to_local_id(expr, self.var) { + // Check that this is a read, not a write. + if !is_in_assignment_position(self.cx, expr) { + span_lint_and_note( + self.cx, + EVAL_ORDER_DEPENDENCE, + expr.span, + "unsequenced read of a variable", + Some(self.write_expr.span), + "whether read occurs before this write depends on evaluation order", + ); } + } + match expr.kind { // We're about to descend a closure. Since we don't know when (or // if) the closure will be evaluated, any reads in it might not // occur here (or ever). Like above, bail to avoid false positives. diff --git a/src/tools/clippy/clippy_lints/src/functions.rs b/src/tools/clippy/clippy_lints/src/functions.rs index 71a146cc298..94200a15420 100644 --- a/src/tools/clippy/clippy_lints/src/functions.rs +++ b/src/tools/clippy/clippy_lints/src/functions.rs @@ -1,7 +1,7 @@ use crate::utils::{ attr_by_name, attrs::is_proc_macro, is_must_use_ty, is_trait_impl_item, is_type_diagnostic_item, iter_input_pats, - last_path_segment, match_def_path, must_use_attr, return_ty, snippet, snippet_opt, span_lint, span_lint_and_help, - span_lint_and_then, trait_ref_of_method, type_is_unsafe_function, + last_path_segment, match_def_path, must_use_attr, path_to_local, return_ty, snippet, snippet_opt, span_lint, + span_lint_and_help, span_lint_and_then, trait_ref_of_method, type_is_unsafe_function, }; use if_chain::if_chain; use rustc_ast::ast::Attribute; @@ -9,7 +9,7 @@ use rustc_data_structures::fx::FxHashSet; use rustc_errors::Applicability; use rustc_hir as hir; use rustc_hir::intravisit; -use rustc_hir::{def::Res, def_id::DefId}; +use rustc_hir::{def::Res, def_id::DefId, QPath}; use rustc_lint::{LateContext, LateLintPass, LintContext}; use rustc_middle::hir::map::Map; use rustc_middle::lint::in_external_macro; @@ -658,16 +658,14 @@ impl<'a, 'tcx> intravisit::Visitor<'tcx> for DerefVisitor<'a, 'tcx> { impl<'a, 'tcx> DerefVisitor<'a, 'tcx> { fn check_arg(&self, ptr: &hir::Expr<'_>) { - if let hir::ExprKind::Path(ref qpath) = ptr.kind { - if let Res::Local(id) = self.cx.qpath_res(qpath, ptr.hir_id) { - if self.ptrs.contains(&id) { - span_lint( - self.cx, - NOT_UNSAFE_PTR_ARG_DEREF, - ptr.span, - "this public function dereferences a raw pointer but is not marked `unsafe`", - ); - } + if let Some(id) = path_to_local(ptr) { + if self.ptrs.contains(&id) { + span_lint( + self.cx, + NOT_UNSAFE_PTR_ARG_DEREF, + ptr.span, + "this public function dereferences a raw pointer but is not marked `unsafe`", + ); } } } @@ -698,7 +696,7 @@ impl<'a, 'tcx> intravisit::Visitor<'tcx> for StaticMutVisitor<'a, 'tcx> { arg.span, &mut tys, ) - && is_mutated_static(self.cx, arg) + && is_mutated_static(arg) { self.mutates_static = true; return; @@ -707,7 +705,7 @@ impl<'a, 'tcx> intravisit::Visitor<'tcx> for StaticMutVisitor<'a, 'tcx> { } }, Assign(ref target, ..) | AssignOp(_, ref target, _) | AddrOf(_, hir::Mutability::Mut, ref target) => { - self.mutates_static |= is_mutated_static(self.cx, target) + self.mutates_static |= is_mutated_static(target) }, _ => {}, } @@ -718,12 +716,13 @@ impl<'a, 'tcx> intravisit::Visitor<'tcx> for StaticMutVisitor<'a, 'tcx> { } } -fn is_mutated_static(cx: &LateContext<'_>, e: &hir::Expr<'_>) -> bool { +fn is_mutated_static(e: &hir::Expr<'_>) -> bool { use hir::ExprKind::{Field, Index, Path}; match e.kind { - Path(ref qpath) => !matches!(cx.qpath_res(qpath, e.hir_id), Res::Local(_)), - Field(ref inner, _) | Index(ref inner, _) => is_mutated_static(cx, inner), + Path(QPath::Resolved(_, path)) => !matches!(path.res, Res::Local(_)), + Path(_) => true, + Field(ref inner, _) | Index(ref inner, _) => is_mutated_static(inner), _ => false, } } diff --git a/src/tools/clippy/clippy_lints/src/let_if_seq.rs b/src/tools/clippy/clippy_lints/src/let_if_seq.rs index 5886c2360e3..5863eef8a26 100644 --- a/src/tools/clippy/clippy_lints/src/let_if_seq.rs +++ b/src/tools/clippy/clippy_lints/src/let_if_seq.rs @@ -1,8 +1,7 @@ -use crate::utils::{snippet, span_lint_and_then, visitors::LocalUsedVisitor}; +use crate::utils::{path_to_local_id, snippet, span_lint_and_then, visitors::LocalUsedVisitor}; use if_chain::if_chain; use rustc_errors::Applicability; use rustc_hir as hir; -use rustc_hir::def::Res; use rustc_hir::BindingAnnotation; use rustc_lint::{LateContext, LateLintPass}; use rustc_session::{declare_lint_pass, declare_tool_lint}; @@ -64,10 +63,11 @@ impl<'tcx> LateLintPass<'tcx> for LetIfSeq { if let hir::PatKind::Binding(mode, canonical_id, ident, None) = local.pat.kind; if let hir::StmtKind::Expr(ref if_) = expr.kind; if let hir::ExprKind::If(ref cond, ref then, ref else_) = if_.kind; - if !LocalUsedVisitor::new(canonical_id).check_expr(cond); + let mut used_visitor = LocalUsedVisitor::new(cx, canonical_id); + if !used_visitor.check_expr(cond); if let hir::ExprKind::Block(ref then, _) = then.kind; if let Some(value) = check_assign(cx, canonical_id, &*then); - if !LocalUsedVisitor::new(canonical_id).check_expr(value); + if !used_visitor.check_expr(value); then { let span = stmt.span.to(if_.span); @@ -144,11 +144,9 @@ fn check_assign<'tcx>( if let Some(expr) = block.stmts.iter().last(); if let hir::StmtKind::Semi(ref expr) = expr.kind; if let hir::ExprKind::Assign(ref var, ref value, _) = expr.kind; - if let hir::ExprKind::Path(ref qpath) = var.kind; - if let Res::Local(local_id) = cx.qpath_res(qpath, var.hir_id); - if decl == local_id; + if path_to_local_id(var, decl); then { - let mut v = LocalUsedVisitor::new(decl); + let mut v = LocalUsedVisitor::new(cx, decl); if block.stmts.iter().take(block.stmts.len()-1).any(|stmt| v.check_stmt(stmt)) { return None; diff --git a/src/tools/clippy/clippy_lints/src/let_underscore.rs b/src/tools/clippy/clippy_lints/src/let_underscore.rs index 6a5a77f8690..7e96dfcc7da 100644 --- a/src/tools/clippy/clippy_lints/src/let_underscore.rs +++ b/src/tools/clippy/clippy_lints/src/let_underscore.rs @@ -5,7 +5,7 @@ use rustc_middle::lint::in_external_macro; use rustc_middle::ty::subst::GenericArgKind; use rustc_session::{declare_lint_pass, declare_tool_lint}; -use crate::utils::{implements_trait, is_must_use_func_call, is_must_use_ty, match_type, paths, span_lint_and_help}; +use crate::utils::{is_must_use_func_call, is_must_use_ty, match_type, paths, span_lint_and_help}; declare_clippy_lint! { /// **What it does:** Checks for `let _ = <expr>` @@ -125,15 +125,6 @@ impl<'tcx> LateLintPass<'tcx> for LetUnderscore { GenericArgKind::Lifetime(_) | GenericArgKind::Const(_) => false, }); - let implements_drop = cx.tcx.lang_items().drop_trait().map_or(false, |drop_trait| - init_ty.walk().any(|inner| match inner.unpack() { - GenericArgKind::Type(inner_ty) => { - implements_trait(cx, inner_ty, drop_trait, &[]) - }, - - GenericArgKind::Lifetime(_) | GenericArgKind::Const(_) => false, - }) - ); if contains_sync_guard { span_lint_and_help( cx, @@ -144,7 +135,7 @@ impl<'tcx> LateLintPass<'tcx> for LetUnderscore { "consider using an underscore-prefixed named \ binding or dropping explicitly with `std::mem::drop`" ) - } else if implements_drop { + } else if init_ty.needs_drop(cx.tcx, cx.param_env) { span_lint_and_help( cx, LET_UNDERSCORE_DROP, diff --git a/src/tools/clippy/clippy_lints/src/lib.rs b/src/tools/clippy/clippy_lints/src/lib.rs index 5a40c00bd67..d96911fac1a 100644 --- a/src/tools/clippy/clippy_lints/src/lib.rs +++ b/src/tools/clippy/clippy_lints/src/lib.rs @@ -310,6 +310,7 @@ mod regex; mod repeat_once; mod returns; mod self_assignment; +mod semicolon_if_nothing_returned; mod serde_api; mod shadow; mod single_component_path_imports; @@ -687,6 +688,7 @@ pub fn register_plugins(store: &mut rustc_lint::LintStore, sess: &Session, conf: &loops::FOR_KV_MAP, &loops::FOR_LOOPS_OVER_FALLIBLES, &loops::ITER_NEXT_LOOP, + &loops::MANUAL_FLATTEN, &loops::MANUAL_MEMCPY, &loops::MUT_RANGE_BOUND, &loops::NEEDLESS_COLLECT, @@ -732,6 +734,7 @@ pub fn register_plugins(store: &mut rustc_lint::LintStore, sess: &Session, conf: &mem_replace::MEM_REPLACE_WITH_DEFAULT, &mem_replace::MEM_REPLACE_WITH_UNINIT, &methods::BIND_INSTEAD_OF_MAP, + &methods::BYTES_NTH, &methods::CHARS_LAST_CMP, &methods::CHARS_NEXT_CMP, &methods::CLONE_DOUBLE_REF, @@ -741,6 +744,7 @@ pub fn register_plugins(store: &mut rustc_lint::LintStore, sess: &Session, conf: &methods::EXPECT_USED, &methods::FILETYPE_IS_FILE, &methods::FILTER_MAP, + &methods::FILTER_MAP_IDENTITY, &methods::FILTER_MAP_NEXT, &methods::FILTER_NEXT, &methods::FLAT_MAP_IDENTITY, @@ -875,6 +879,7 @@ pub fn register_plugins(store: &mut rustc_lint::LintStore, sess: &Session, conf: &returns::LET_AND_RETURN, &returns::NEEDLESS_RETURN, &self_assignment::SELF_ASSIGNMENT, + &semicolon_if_nothing_returned::SEMICOLON_IF_NOTHING_RETURNED, &serde_api::SERDE_API_MISUSE, &shadow::SHADOW_REUSE, &shadow::SHADOW_SAME, @@ -1179,7 +1184,8 @@ pub fn register_plugins(store: &mut rustc_lint::LintStore, sess: &Session, conf: store.register_early_pass(|| box redundant_else::RedundantElse); store.register_late_pass(|| box create_dir::CreateDir); store.register_early_pass(|| box needless_arbitrary_self_type::NeedlessArbitrarySelfType); - store.register_late_pass(|| box cargo_common_metadata::CargoCommonMetadata); + let cargo_ignore_publish = conf.cargo_ignore_publish; + store.register_late_pass(move || box cargo_common_metadata::CargoCommonMetadata::new(cargo_ignore_publish)); store.register_late_pass(|| box multiple_crate_versions::MultipleCrateVersions); store.register_late_pass(|| box wildcard_dependencies::WildcardDependencies); let literal_representation_lint_fraction_readability = conf.unreadable_literal_lint_fractions; @@ -1236,6 +1242,7 @@ pub fn register_plugins(store: &mut rustc_lint::LintStore, sess: &Session, conf: store.register_late_pass(|| box manual_unwrap_or::ManualUnwrapOr); store.register_late_pass(|| box manual_ok_or::ManualOkOr); store.register_late_pass(|| box float_equality_without_abs::FloatEqualityWithoutAbs); + store.register_late_pass(|| box semicolon_if_nothing_returned::SemicolonIfNothingReturned); store.register_late_pass(|| box async_yields_async::AsyncYieldsAsync); let disallowed_methods = conf.disallowed_methods.iter().cloned().collect::<FxHashSet<_>>(); store.register_late_pass(move || box disallowed_method::DisallowedMethod::new(&disallowed_methods)); @@ -1290,6 +1297,7 @@ pub fn register_plugins(store: &mut rustc_lint::LintStore, sess: &Session, conf: LintId::of(&panic_unimplemented::UNIMPLEMENTED), LintId::of(&panic_unimplemented::UNREACHABLE), LintId::of(&pattern_type_mismatch::PATTERN_TYPE_MISMATCH), + LintId::of(&semicolon_if_nothing_returned::SEMICOLON_IF_NOTHING_RETURNED), LintId::of(&shadow::SHADOW_REUSE), LintId::of(&shadow::SHADOW_SAME), LintId::of(&strings::STRING_ADD), @@ -1491,6 +1499,7 @@ pub fn register_plugins(store: &mut rustc_lint::LintStore, sess: &Session, conf: LintId::of(&loops::FOR_KV_MAP), LintId::of(&loops::FOR_LOOPS_OVER_FALLIBLES), LintId::of(&loops::ITER_NEXT_LOOP), + LintId::of(&loops::MANUAL_FLATTEN), LintId::of(&loops::MANUAL_MEMCPY), LintId::of(&loops::MUT_RANGE_BOUND), LintId::of(&loops::NEEDLESS_COLLECT), @@ -1524,11 +1533,13 @@ pub fn register_plugins(store: &mut rustc_lint::LintStore, sess: &Session, conf: LintId::of(&mem_replace::MEM_REPLACE_WITH_DEFAULT), LintId::of(&mem_replace::MEM_REPLACE_WITH_UNINIT), LintId::of(&methods::BIND_INSTEAD_OF_MAP), + LintId::of(&methods::BYTES_NTH), LintId::of(&methods::CHARS_LAST_CMP), LintId::of(&methods::CHARS_NEXT_CMP), LintId::of(&methods::CLONE_DOUBLE_REF), LintId::of(&methods::CLONE_ON_COPY), LintId::of(&methods::EXPECT_FUN_CALL), + LintId::of(&methods::FILTER_MAP_IDENTITY), LintId::of(&methods::FILTER_NEXT), LintId::of(&methods::FLAT_MAP_IDENTITY), LintId::of(&methods::FROM_ITER_INSTEAD_OF_COLLECT), @@ -1620,7 +1631,6 @@ pub fn register_plugins(store: &mut rustc_lint::LintStore, sess: &Session, conf: LintId::of(&reference::DEREF_ADDROF), LintId::of(&reference::REF_IN_DEREF), LintId::of(®ex::INVALID_REGEX), - LintId::of(®ex::TRIVIAL_REGEX), LintId::of(&repeat_once::REPEAT_ONCE), LintId::of(&returns::LET_AND_RETURN), LintId::of(&returns::NEEDLESS_RETURN), @@ -1741,6 +1751,7 @@ pub fn register_plugins(store: &mut rustc_lint::LintStore, sess: &Session, conf: LintId::of(&matches::SINGLE_MATCH), LintId::of(&mem_replace::MEM_REPLACE_OPTION_WITH_NONE), LintId::of(&mem_replace::MEM_REPLACE_WITH_DEFAULT), + LintId::of(&methods::BYTES_NTH), LintId::of(&methods::CHARS_LAST_CMP), LintId::of(&methods::CHARS_NEXT_CMP), LintId::of(&methods::FROM_ITER_INSTEAD_OF_COLLECT), @@ -1783,7 +1794,6 @@ pub fn register_plugins(store: &mut rustc_lint::LintStore, sess: &Session, conf: LintId::of(&ranges::MANUAL_RANGE_CONTAINS), LintId::of(&redundant_field_names::REDUNDANT_FIELD_NAMES), LintId::of(&redundant_static_lifetimes::REDUNDANT_STATIC_LIFETIMES), - LintId::of(®ex::TRIVIAL_REGEX), LintId::of(&returns::LET_AND_RETURN), LintId::of(&returns::NEEDLESS_RETURN), LintId::of(&single_component_path_imports::SINGLE_COMPONENT_PATH_IMPORTS), @@ -1822,6 +1832,7 @@ pub fn register_plugins(store: &mut rustc_lint::LintStore, sess: &Session, conf: LintId::of(&lifetimes::EXTRA_UNUSED_LIFETIMES), LintId::of(&lifetimes::NEEDLESS_LIFETIMES), LintId::of(&loops::EXPLICIT_COUNTER_LOOP), + LintId::of(&loops::MANUAL_FLATTEN), LintId::of(&loops::MUT_RANGE_BOUND), LintId::of(&loops::SINGLE_ELEMENT_LOOP), LintId::of(&loops::WHILE_LET_LOOP), @@ -1835,6 +1846,7 @@ pub fn register_plugins(store: &mut rustc_lint::LintStore, sess: &Session, conf: LintId::of(&matches::WILDCARD_IN_OR_PATTERNS), LintId::of(&methods::BIND_INSTEAD_OF_MAP), LintId::of(&methods::CLONE_ON_COPY), + LintId::of(&methods::FILTER_MAP_IDENTITY), LintId::of(&methods::FILTER_NEXT), LintId::of(&methods::FLAT_MAP_IDENTITY), LintId::of(&methods::INSPECT_FOR_EACH), @@ -2011,6 +2023,7 @@ pub fn register_plugins(store: &mut rustc_lint::LintStore, sess: &Session, conf: LintId::of(&needless_borrow::NEEDLESS_BORROW), LintId::of(&path_buf_push_overwrite::PATH_BUF_PUSH_OVERWRITE), LintId::of(&redundant_pub_crate::REDUNDANT_PUB_CRATE), + LintId::of(®ex::TRIVIAL_REGEX), LintId::of(&strings::STRING_LIT_AS_BYTES), LintId::of(&transmute::USELESS_TRANSMUTE), LintId::of(&use_self::USE_SELF), diff --git a/src/tools/clippy/clippy_lints/src/loops.rs b/src/tools/clippy/clippy_lints/src/loops.rs index 5211ca7da32..eb185377e20 100644 --- a/src/tools/clippy/clippy_lints/src/loops.rs +++ b/src/tools/clippy/clippy_lints/src/loops.rs @@ -1,14 +1,13 @@ use crate::consts::constant; -use crate::utils::paths; use crate::utils::sugg::Sugg; -use crate::utils::usage::{is_unused, mutated_variables}; +use crate::utils::usage::mutated_variables; use crate::utils::visitors::LocalUsedVisitor; use crate::utils::{ contains_name, get_enclosing_block, get_parent_expr, get_trait_def_id, has_iter_method, higher, implements_trait, - indent_of, is_in_panic_handler, is_integer_const, is_no_std_crate, is_refutable, is_type_diagnostic_item, - last_path_segment, match_trait_method, match_type, match_var, multispan_sugg, single_segment_path, snippet, - snippet_with_applicability, snippet_with_macro_callsite, span_lint, span_lint_and_help, span_lint_and_sugg, - span_lint_and_then, sugg, SpanlessEq, + indent_of, is_in_panic_handler, is_integer_const, is_no_std_crate, is_ok_ctor, is_refutable, is_some_ctor, + is_type_diagnostic_item, last_path_segment, match_trait_method, match_type, multispan_sugg, path_to_local, + path_to_local_id, paths, single_segment_path, snippet, snippet_with_applicability, snippet_with_macro_callsite, + span_lint, span_lint_and_help, span_lint_and_sugg, span_lint_and_then, sugg, SpanlessEq, }; use if_chain::if_chain; use rustc_ast::ast; @@ -494,8 +493,40 @@ declare_clippy_lint! { "there is no reason to have a single element loop" } +declare_clippy_lint! { + /// **What it does:** Check for unnecessary `if let` usage in a for loop + /// where only the `Some` or `Ok` variant of the iterator element is used. + /// + /// **Why is this bad?** It is verbose and can be simplified + /// by first calling the `flatten` method on the `Iterator`. + /// + /// **Known problems:** None. + /// + /// **Example:** + /// + /// ```rust + /// let x = vec![Some(1), Some(2), Some(3)]; + /// for n in x { + /// if let Some(n) = n { + /// println!("{}", n); + /// } + /// } + /// ``` + /// Use instead: + /// ```rust + /// let x = vec![Some(1), Some(2), Some(3)]; + /// for n in x.into_iter().flatten() { + /// println!("{}", n); + /// } + /// ``` + pub MANUAL_FLATTEN, + complexity, + "for loops over `Option`s or `Result`s with a single expression can be simplified" +} + declare_lint_pass!(Loops => [ MANUAL_MEMCPY, + MANUAL_FLATTEN, NEEDLESS_RANGE_LOOP, EXPLICIT_ITER_LOOP, EXPLICIT_INTO_ITER_LOOP, @@ -517,14 +548,14 @@ declare_lint_pass!(Loops => [ impl<'tcx> LateLintPass<'tcx> for Loops { #[allow(clippy::too_many_lines)] fn check_expr(&mut self, cx: &LateContext<'tcx>, expr: &'tcx Expr<'_>) { - if let Some((pat, arg, body)) = higher::for_loop(expr) { + if let Some((pat, arg, body, span)) = higher::for_loop(expr) { // we don't want to check expanded macros // this check is not at the top of the function // since higher::for_loop expressions are marked as expansions if body.span.from_expansion() { return; } - check_for_loop(cx, pat, arg, body, expr); + check_for_loop(cx, pat, arg, body, expr, span); } // we don't want to check expanded macros @@ -707,7 +738,7 @@ fn combine_branches(b1: NeverLoopResult, b2: NeverLoopResult) -> NeverLoopResult fn never_loop_block(block: &Block<'_>, main_loop_id: HirId) -> NeverLoopResult { let stmts = block.stmts.iter().map(stmt_to_expr); let expr = once(block.expr.as_deref()); - let mut iter = stmts.chain(expr).filter_map(|e| e); + let mut iter = stmts.chain(expr).flatten(); never_loop_expr_seq(&mut iter, main_loop_id) } @@ -819,6 +850,7 @@ fn check_for_loop<'tcx>( arg: &'tcx Expr<'_>, body: &'tcx Expr<'_>, expr: &'tcx Expr<'_>, + span: Span, ) { let is_manual_memcpy_triggered = detect_manual_memcpy(cx, pat, arg, body, expr); if !is_manual_memcpy_triggered { @@ -830,6 +862,7 @@ fn check_for_loop<'tcx>( check_for_mut_range_bound(cx, arg, body); check_for_single_element_loop(cx, pat, arg, body, expr); detect_same_item_push(cx, pat, arg, body, expr); + check_manual_flatten(cx, pat, arg, body, span); } // this function assumes the given expression is a `for` loop. @@ -843,21 +876,6 @@ fn get_span_of_entire_for_loop(expr: &Expr<'_>) -> Span { } } -fn same_var<'tcx>(cx: &LateContext<'tcx>, expr: &Expr<'_>, var: HirId) -> bool { - if_chain! { - if let ExprKind::Path(qpath) = &expr.kind; - if let QPath::Resolved(None, path) = qpath; - if path.segments.len() == 1; - if let Res::Local(local_id) = cx.qpath_res(qpath, expr.hir_id); - then { - // our variable! - local_id == var - } else { - false - } - } -} - /// a wrapper of `Sugg`. Besides what `Sugg` do, this removes unnecessary `0`; /// and also, it avoids subtracting a variable from the same one by replacing it with `0`. /// it exists for the convenience of the overloaded operators while normal functions can do the @@ -1010,14 +1028,9 @@ fn get_details_from_idx<'tcx>( idx: &Expr<'_>, starts: &[Start<'tcx>], ) -> Option<(StartKind<'tcx>, Offset)> { - fn get_start<'tcx>(cx: &LateContext<'tcx>, e: &Expr<'_>, starts: &[Start<'tcx>]) -> Option<StartKind<'tcx>> { - starts.iter().find_map(|start| { - if same_var(cx, e, start.id) { - Some(start.kind) - } else { - None - } - }) + fn get_start<'tcx>(e: &Expr<'_>, starts: &[Start<'tcx>]) -> Option<StartKind<'tcx>> { + let id = path_to_local(e)?; + starts.iter().find(|start| start.id == id).map(|start| start.kind) } fn get_offset<'tcx>(cx: &LateContext<'tcx>, e: &Expr<'_>, starts: &[Start<'tcx>]) -> Option<Sugg<'static>> { @@ -1026,7 +1039,7 @@ fn get_details_from_idx<'tcx>( ast::LitKind::Int(x, _ty) => Some(Sugg::NonParen(x.to_string().into())), _ => None, }, - ExprKind::Path(..) if get_start(cx, e, starts).is_none() => Some(Sugg::hir(cx, e, "???")), + ExprKind::Path(..) if get_start(e, starts).is_none() => Some(Sugg::hir(cx, e, "???")), _ => None, } } @@ -1034,18 +1047,18 @@ fn get_details_from_idx<'tcx>( match idx.kind { ExprKind::Binary(op, lhs, rhs) => match op.node { BinOpKind::Add => { - let offset_opt = get_start(cx, lhs, starts) + let offset_opt = get_start(lhs, starts) .and_then(|s| get_offset(cx, rhs, starts).map(|o| (s, o))) - .or_else(|| get_start(cx, rhs, starts).and_then(|s| get_offset(cx, lhs, starts).map(|o| (s, o)))); + .or_else(|| get_start(rhs, starts).and_then(|s| get_offset(cx, lhs, starts).map(|o| (s, o)))); offset_opt.map(|(s, o)| (s, Offset::positive(o))) }, BinOpKind::Sub => { - get_start(cx, lhs, starts).and_then(|s| get_offset(cx, rhs, starts).map(|o| (s, Offset::negative(o)))) + get_start(lhs, starts).and_then(|s| get_offset(cx, rhs, starts).map(|o| (s, Offset::negative(o)))) }, _ => None, }, - ExprKind::Path(..) => get_start(cx, idx, starts).map(|s| (s, Offset::empty())), + ExprKind::Path(..) => get_start(idx, starts).map(|s| (s, Offset::empty())), _ => None, } } @@ -1062,11 +1075,10 @@ fn get_assignment<'tcx>(e: &'tcx Expr<'tcx>) -> Option<(&'tcx Expr<'tcx>, &'tcx /// The returned iterator yields `None` if no assignment expressions are there, /// filtering out the increments of the given whitelisted loop counters; /// because its job is to make sure there's nothing other than assignments and the increments. -fn get_assignments<'a: 'c, 'tcx: 'c, 'c>( - cx: &'a LateContext<'tcx>, +fn get_assignments<'a, 'tcx>( Block { stmts, expr, .. }: &'tcx Block<'tcx>, - loop_counters: &'c [Start<'tcx>], -) -> impl Iterator<Item = Option<(&'tcx Expr<'tcx>, &'tcx Expr<'tcx>)>> + 'c { + loop_counters: &'a [Start<'tcx>], +) -> impl Iterator<Item = Option<(&'tcx Expr<'tcx>, &'tcx Expr<'tcx>)>> + 'a { // As the `filter` and `map` below do different things, I think putting together // just increases complexity. (cc #3188 and #4193) stmts @@ -1078,12 +1090,14 @@ fn get_assignments<'a: 'c, 'tcx: 'c, 'c>( .chain((*expr).into_iter()) .filter(move |e| { if let ExprKind::AssignOp(_, place, _) = e.kind { - !loop_counters - .iter() - // skip the first item which should be `StartKind::Range` - // this makes it possible to use the slice with `StartKind::Range` in the same iterator loop. - .skip(1) - .any(|counter| same_var(cx, place, counter.id)) + path_to_local(place).map_or(false, |id| { + !loop_counters + .iter() + // skip the first item which should be `StartKind::Range` + // this makes it possible to use the slice with `StartKind::Range` in the same iterator loop. + .skip(1) + .any(|counter| counter.id == id) + }) } else { true } @@ -1140,7 +1154,7 @@ fn build_manual_memcpy_suggestion<'tcx>( if method.ident.name == sym!(len); if len_args.len() == 1; if let Some(arg) = len_args.get(0); - if var_def_id(cx, arg) == var_def_id(cx, base); + if path_to_local(arg) == path_to_local(base); then { if sugg.as_str() == end_str { sugg::EMPTY.into() @@ -1245,7 +1259,7 @@ fn detect_manual_memcpy<'tcx>( if let Some(loop_counters) = get_loop_counters(cx, block, expr) { starts.extend(loop_counters); } - iter_a = Some(get_assignments(cx, block, &starts)); + iter_a = Some(get_assignments(block, &starts)); } else { iter_b = Some(get_assignment(body)); } @@ -1267,7 +1281,7 @@ fn detect_manual_memcpy<'tcx>( if let Some((start_right, offset_right)) = get_details_from_idx(cx, &idx_right, &starts); // Source and destination must be different - if var_def_id(cx, base_left) != var_def_id(cx, base_right); + if path_to_local(base_left) != path_to_local(base_right); then { Some((IndexExpr { base: base_left, idx: start_left, idx_offset: offset_left }, IndexExpr { base: base_right, idx: start_right, idx_offset: offset_right })) @@ -1879,8 +1893,8 @@ fn check_for_loop_over_map_kv<'tcx>( let arg_span = arg.span; let (new_pat_span, kind, ty, mutbl) = match *cx.typeck_results().expr_ty(arg).kind() { ty::Ref(_, ty, mutbl) => match (&pat[0].kind, &pat[1].kind) { - (key, _) if pat_is_wild(key, body) => (pat[1].span, "value", ty, mutbl), - (_, value) if pat_is_wild(value, body) => (pat[0].span, "key", ty, Mutability::Not), + (key, _) if pat_is_wild(cx, key, body) => (pat[1].span, "value", ty, mutbl), + (_, value) if pat_is_wild(cx, value, body) => (pat[0].span, "key", ty, Mutability::Not), _ => return, }, _ => return, @@ -1953,6 +1967,77 @@ fn check_for_single_element_loop<'tcx>( } } +/// Check for unnecessary `if let` usage in a for loop where only the `Some` or `Ok` variant of the +/// iterator element is used. +fn check_manual_flatten<'tcx>( + cx: &LateContext<'tcx>, + pat: &'tcx Pat<'_>, + arg: &'tcx Expr<'_>, + body: &'tcx Expr<'_>, + span: Span, +) { + if let ExprKind::Block(ref block, _) = body.kind { + // Ensure the `if let` statement is the only expression or statement in the for-loop + let inner_expr = if block.stmts.len() == 1 && block.expr.is_none() { + let match_stmt = &block.stmts[0]; + if let StmtKind::Semi(inner_expr) = match_stmt.kind { + Some(inner_expr) + } else { + None + } + } else if block.stmts.is_empty() { + block.expr + } else { + None + }; + + if_chain! { + if let Some(inner_expr) = inner_expr; + if let ExprKind::Match( + ref match_expr, ref match_arms, MatchSource::IfLetDesugar{ contains_else_clause: false } + ) = inner_expr.kind; + // Ensure match_expr in `if let` statement is the same as the pat from the for-loop + if let PatKind::Binding(_, pat_hir_id, _, _) = pat.kind; + if path_to_local_id(match_expr, pat_hir_id); + // Ensure the `if let` statement is for the `Some` variant of `Option` or the `Ok` variant of `Result` + if let PatKind::TupleStruct(QPath::Resolved(None, path), _, _) = match_arms[0].pat.kind; + let some_ctor = is_some_ctor(cx, path.res); + let ok_ctor = is_ok_ctor(cx, path.res); + if some_ctor || ok_ctor; + let if_let_type = if some_ctor { "Some" } else { "Ok" }; + + then { + // Prepare the error message + let msg = format!("unnecessary `if let` since only the `{}` variant of the iterator element is used", if_let_type); + + // Prepare the help message + let mut applicability = Applicability::MaybeIncorrect; + let arg_snippet = make_iterator_snippet(cx, arg, &mut applicability); + + span_lint_and_then( + cx, + MANUAL_FLATTEN, + span, + &msg, + |diag| { + let sugg = format!("{}.flatten()", arg_snippet); + diag.span_suggestion( + arg.span, + "try", + sugg, + Applicability::MaybeIncorrect, + ); + diag.span_help( + inner_expr.span, + "...and remove the `if let` statement in the for loop", + ); + } + ); + } + } + } +} + struct MutatePairDelegate<'a, 'tcx> { cx: &'a LateContext<'tcx>, hir_id_low: Option<HirId>, @@ -2024,20 +2109,11 @@ fn mut_warn_with_span(cx: &LateContext<'_>, span: Option<Span>) { fn check_for_mutability(cx: &LateContext<'_>, bound: &Expr<'_>) -> Option<HirId> { if_chain! { - if let ExprKind::Path(ref qpath) = bound.kind; - if let QPath::Resolved(None, _) = *qpath; + if let Some(hir_id) = path_to_local(bound); + if let Node::Binding(pat) = cx.tcx.hir().get(hir_id); + if let PatKind::Binding(BindingAnnotation::Mutable, ..) = pat.kind; then { - let res = cx.qpath_res(qpath, bound.hir_id); - if let Res::Local(hir_id) = res { - let node_str = cx.tcx.hir().get(hir_id); - if_chain! { - if let Node::Binding(pat) = node_str; - if let PatKind::Binding(BindingAnnotation::Mutable, ..) = pat.kind; - then { - return Some(hir_id); - } - } - } + return Some(hir_id); } } None @@ -2069,10 +2145,12 @@ fn check_for_mutation<'tcx>( } /// Returns `true` if the pattern is a `PatWild` or an ident prefixed with `_`. -fn pat_is_wild<'tcx>(pat: &'tcx PatKind<'_>, body: &'tcx Expr<'_>) -> bool { +fn pat_is_wild<'tcx>(cx: &LateContext<'tcx>, pat: &'tcx PatKind<'_>, body: &'tcx Expr<'_>) -> bool { match *pat { PatKind::Wild => true, - PatKind::Binding(.., ident, None) if ident.as_str().starts_with('_') => is_unused(&ident, body), + PatKind::Binding(_, id, ident, None) if ident.as_str().starts_with('_') => { + !LocalUsedVisitor::new(cx, id).check_expr(body) + }, _ => false, } } @@ -2108,9 +2186,9 @@ impl<'a, 'tcx> VarVisitor<'a, 'tcx> { if let QPath::Resolved(None, ref seqvar) = *seqpath; if seqvar.segments.len() == 1; then { - let index_used_directly = same_var(self.cx, idx, self.var); + let index_used_directly = path_to_local_id(idx, self.var); let indexed_indirectly = { - let mut used_visitor = LocalUsedVisitor::new(self.var); + let mut used_visitor = LocalUsedVisitor::new(self.cx, self.var); walk_expr(&mut used_visitor, idx); used_visitor.used }; @@ -2179,17 +2257,14 @@ impl<'a, 'tcx> Visitor<'tcx> for VarVisitor<'a, 'tcx> { if_chain! { // directly using a variable - if let ExprKind::Path(ref qpath) = expr.kind; - if let QPath::Resolved(None, ref path) = *qpath; - if path.segments.len() == 1; + if let ExprKind::Path(QPath::Resolved(None, path)) = expr.kind; + if let Res::Local(local_id) = path.res; then { - if let Res::Local(local_id) = self.cx.qpath_res(qpath, expr.hir_id) { - if local_id == self.var { - self.nonindex = true; - } else { - // not the correct variable, but still a variable - self.referenced.insert(path.segments[0].ident.name); - } + if local_id == self.var { + self.nonindex = true; + } else { + // not the correct variable, but still a variable + self.referenced.insert(path.segments[0].ident.name); } } } @@ -2247,7 +2322,7 @@ impl<'a, 'tcx> Visitor<'tcx> for VarVisitor<'a, 'tcx> { } fn is_used_inside<'tcx>(cx: &LateContext<'tcx>, expr: &'tcx Expr<'_>, container: &'tcx Expr<'_>) -> bool { - let def_id = match var_def_id(cx, expr) { + let def_id = match path_to_local(expr) { Some(id) => id, None => return false, }; @@ -2260,12 +2335,11 @@ fn is_used_inside<'tcx>(cx: &LateContext<'tcx>, expr: &'tcx Expr<'_>, container: } fn is_iterator_used_after_while_let<'tcx>(cx: &LateContext<'tcx>, iter_expr: &'tcx Expr<'_>) -> bool { - let def_id = match var_def_id(cx, iter_expr) { + let def_id = match path_to_local(iter_expr) { Some(id) => id, None => return false, }; let mut visitor = VarUsedAfterLoopVisitor { - cx, def_id, iter_expr_id: iter_expr.hir_id, past_while_let: false, @@ -2277,20 +2351,19 @@ fn is_iterator_used_after_while_let<'tcx>(cx: &LateContext<'tcx>, iter_expr: &'t visitor.var_used_after_while_let } -struct VarUsedAfterLoopVisitor<'a, 'tcx> { - cx: &'a LateContext<'tcx>, +struct VarUsedAfterLoopVisitor { def_id: HirId, iter_expr_id: HirId, past_while_let: bool, var_used_after_while_let: bool, } -impl<'a, 'tcx> Visitor<'tcx> for VarUsedAfterLoopVisitor<'a, 'tcx> { +impl<'tcx> Visitor<'tcx> for VarUsedAfterLoopVisitor { type Map = Map<'tcx>; fn visit_expr(&mut self, expr: &'tcx Expr<'_>) { if self.past_while_let { - if Some(self.def_id) == var_def_id(self.cx, expr) { + if path_to_local_id(expr, self.def_id) { self.var_used_after_while_let = true; } } else if self.iter_expr_id == expr.hir_id { @@ -2412,7 +2485,7 @@ impl<'a, 'tcx> Visitor<'tcx> for IncrementVisitor<'a, 'tcx> { } // If node is a variable - if let Some(def_id) = var_def_id(self.cx, expr) { + if let Some(def_id) = path_to_local(expr) { if let Some(parent) = get_parent_expr(self.cx, expr) { let state = self.states.entry(def_id).or_insert(IncrementVisitorVarState::Initial); if *state == IncrementVisitorVarState::IncrOnce { @@ -2539,7 +2612,7 @@ impl<'a, 'tcx> Visitor<'tcx> for InitializeVisitor<'a, 'tcx> { } // If node is the desired variable, see how it's used - if var_def_id(self.cx, expr) == Some(self.var_id) { + if path_to_local_id(expr, self.var_id) { if self.past_loop { self.state = InitializeVisitorState::DontWarn; return; @@ -2586,16 +2659,6 @@ impl<'a, 'tcx> Visitor<'tcx> for InitializeVisitor<'a, 'tcx> { } } -fn var_def_id(cx: &LateContext<'_>, expr: &Expr<'_>) -> Option<HirId> { - if let ExprKind::Path(ref qpath) = expr.kind { - let path_res = cx.qpath_res(qpath, expr.hir_id); - if let Res::Local(hir_id) = path_res { - return Some(hir_id); - } - } - None -} - fn is_loop(expr: &Expr<'_>) -> bool { matches!(expr.kind, ExprKind::Loop(..)) } @@ -2618,8 +2681,8 @@ fn is_nested(cx: &LateContext<'_>, match_expr: &Expr<'_>, iter_expr: &Expr<'_>) fn is_loop_nested(cx: &LateContext<'_>, loop_expr: &Expr<'_>, iter_expr: &Expr<'_>) -> bool { let mut id = loop_expr.hir_id; - let iter_name = if let Some(name) = path_name(iter_expr) { - name + let iter_id = if let Some(id) = path_to_local(iter_expr) { + id } else { return true; }; @@ -2637,7 +2700,7 @@ fn is_loop_nested(cx: &LateContext<'_>, loop_expr: &Expr<'_>, iter_expr: &Expr<' Some(Node::Block(block)) => { let mut block_visitor = LoopNestVisitor { hir_id: id, - iterator: iter_name, + iterator: iter_id, nesting: Unknown, }; walk_block(&mut block_visitor, block); @@ -2665,7 +2728,7 @@ use self::Nesting::{LookFurther, RuledOut, Unknown}; struct LoopNestVisitor { hir_id: HirId, - iterator: Symbol, + iterator: HirId, nesting: Nesting, } @@ -2690,7 +2753,7 @@ impl<'tcx> Visitor<'tcx> for LoopNestVisitor { } match expr.kind { ExprKind::Assign(ref path, _, _) | ExprKind::AssignOp(_, ref path, _) => { - if match_var(path, self.iterator) { + if path_to_local_id(path, self.iterator) { self.nesting = RuledOut; } }, @@ -2702,8 +2765,8 @@ impl<'tcx> Visitor<'tcx> for LoopNestVisitor { if self.nesting != Unknown { return; } - if let PatKind::Binding(.., span_name, _) = pat.kind { - if self.iterator == span_name.name { + if let PatKind::Binding(_, id, ..) = pat.kind { + if id == self.iterator { self.nesting = RuledOut; return; } @@ -2716,16 +2779,6 @@ impl<'tcx> Visitor<'tcx> for LoopNestVisitor { } } -fn path_name(e: &Expr<'_>) -> Option<Symbol> { - if let ExprKind::Path(QPath::Resolved(_, ref path)) = e.kind { - let segments = &path.segments; - if segments.len() == 1 { - return Some(segments[0].ident.name); - } - }; - None -} - fn check_infinite_loop<'tcx>(cx: &LateContext<'tcx>, cond: &'tcx Expr<'_>, expr: &'tcx Expr<'_>) { if constant(cx, cx.typeck_results(), cond).is_some() { // A pure constant condition (e.g., `while false`) is not linted. @@ -3087,7 +3140,7 @@ impl<'a, 'tcx> Visitor<'tcx> for UsedCountVisitor<'a, 'tcx> { type Map = Map<'tcx>; fn visit_expr(&mut self, expr: &'tcx Expr<'_>) { - if same_var(self.cx, expr, self.id) { + if path_to_local_id(expr, self.id) { self.count += 1; } else { walk_expr(self, expr); diff --git a/src/tools/clippy/clippy_lints/src/macro_use.rs b/src/tools/clippy/clippy_lints/src/macro_use.rs index bb52888883a..40f04bd677d 100644 --- a/src/tools/clippy/clippy_lints/src/macro_use.rs +++ b/src/tools/clippy/clippy_lints/src/macro_use.rs @@ -160,7 +160,7 @@ impl<'tcx> LateLintPass<'tcx> for MacroUseImports { let found_idx = self.mac_refs.iter().position(|mac| import.ends_with(&mac.name)); if let Some(idx) = found_idx { - let _ = self.mac_refs.remove(idx); + self.mac_refs.remove(idx); let seg = import.split("::").collect::<Vec<_>>(); match seg.as_slice() { diff --git a/src/tools/clippy/clippy_lints/src/manual_ok_or.rs b/src/tools/clippy/clippy_lints/src/manual_ok_or.rs index 8c77e155b70..efb05b8ffdf 100644 --- a/src/tools/clippy/clippy_lints/src/manual_ok_or.rs +++ b/src/tools/clippy/clippy_lints/src/manual_ok_or.rs @@ -1,9 +1,10 @@ use crate::utils::{ - indent_of, is_type_diagnostic_item, match_qpath, paths, reindent_multiline, snippet_opt, span_lint_and_sugg, + indent_of, is_type_diagnostic_item, match_qpath, path_to_local_id, paths, reindent_multiline, snippet_opt, + span_lint_and_sugg, }; use if_chain::if_chain; use rustc_errors::Applicability; -use rustc_hir::{def, Expr, ExprKind, PatKind, QPath}; +use rustc_hir::{Expr, ExprKind, PatKind}; use rustc_lint::LintContext; use rustc_lint::{LateContext, LateLintPass}; use rustc_middle::lint::in_external_macro; @@ -90,8 +91,6 @@ fn is_ok_wrapping(cx: &LateContext<'_>, map_expr: &Expr<'_>) -> bool { if let PatKind::Binding(_, param_id, ..) = body.params[0].pat.kind; if let ExprKind::Call(Expr { kind: ExprKind::Path(ok_path), .. }, &[ref ok_arg]) = body.value.kind; if match_qpath(ok_path, &paths::RESULT_OK); - if let ExprKind::Path(QPath::Resolved(_, ok_arg_path)) = ok_arg.kind; - if let def::Res::Local(ok_arg_path_id) = ok_arg_path.res; - then { param_id == ok_arg_path_id } else { false } + then { path_to_local_id(ok_arg, param_id) } else { false } } } diff --git a/src/tools/clippy/clippy_lints/src/manual_unwrap_or.rs b/src/tools/clippy/clippy_lints/src/manual_unwrap_or.rs index 9e2c6c7f231..b452225b5db 100644 --- a/src/tools/clippy/clippy_lints/src/manual_unwrap_or.rs +++ b/src/tools/clippy/clippy_lints/src/manual_unwrap_or.rs @@ -1,9 +1,9 @@ use crate::consts::constant_simple; use crate::utils; -use crate::utils::sugg; +use crate::utils::{path_to_local_id, sugg}; use if_chain::if_chain; use rustc_errors::Applicability; -use rustc_hir::{def, Arm, Expr, ExprKind, Pat, PatKind, QPath}; +use rustc_hir::{Arm, Expr, ExprKind, Pat, PatKind}; use rustc_lint::LintContext; use rustc_lint::{LateContext, LateLintPass}; use rustc_middle::lint::in_external_macro; @@ -83,9 +83,7 @@ fn lint_manual_unwrap_or<'tcx>(cx: &LateContext<'tcx>, expr: &'tcx Expr<'tcx>) { if utils::match_qpath(unwrap_qpath, &utils::paths::OPTION_SOME) || utils::match_qpath(unwrap_qpath, &utils::paths::RESULT_OK); if let PatKind::Binding(_, binding_hir_id, ..) = unwrap_pat.kind; - if let ExprKind::Path(QPath::Resolved(_, body_path)) = unwrap_arm.body.kind; - if let def::Res::Local(body_path_hir_id) = body_path.res; - if body_path_hir_id == binding_hir_id; + if path_to_local_id(unwrap_arm.body, binding_hir_id); if !utils::usage::contains_return_break_continue_macro(or_arm.body); then { Some(or_arm) diff --git a/src/tools/clippy/clippy_lints/src/matches.rs b/src/tools/clippy/clippy_lints/src/matches.rs index ba7b9bd0424..e33001b16bc 100644 --- a/src/tools/clippy/clippy_lints/src/matches.rs +++ b/src/tools/clippy/clippy_lints/src/matches.rs @@ -1,11 +1,12 @@ use crate::consts::{constant, miri_to_const, Constant}; use crate::utils::sugg::Sugg; -use crate::utils::usage::is_unused; +use crate::utils::visitors::LocalUsedVisitor; use crate::utils::{ - expr_block, get_arg_name, get_parent_expr, implements_trait, in_macro, indent_of, is_allowed, is_expn_of, - is_refutable, is_type_diagnostic_item, is_wild, match_qpath, match_type, match_var, meets_msrv, multispan_sugg, + expr_block, get_parent_expr, implements_trait, in_macro, indent_of, is_allowed, is_expn_of, is_refutable, + is_type_diagnostic_item, is_wild, match_qpath, match_type, meets_msrv, multispan_sugg, path_to_local_id, peel_hir_pat_refs, peel_mid_ty_refs, peel_n_hir_expr_refs, remove_blocks, snippet, snippet_block, snippet_opt, snippet_with_applicability, span_lint_and_help, span_lint_and_note, span_lint_and_sugg, span_lint_and_then, + strip_pat_refs, }; use crate::utils::{paths, search_same, SpanlessEq, SpanlessHash}; use if_chain::if_chain; @@ -616,9 +617,9 @@ impl<'tcx> LateLintPass<'tcx> for Matches { if let PatKind::TupleStruct( QPath::Resolved(None, ref variant_name), ref args, _) = arms[0].pat.kind; if args.len() == 1; - if let Some(arg) = get_arg_name(&args[0]); + if let PatKind::Binding(_, arg, ..) = strip_pat_refs(&args[0]).kind; let body = remove_blocks(&arms[0].body); - if match_var(body, arg); + if path_to_local_id(body, arg); then { let mut applicability = Applicability::MachineApplicable; @@ -910,7 +911,7 @@ fn check_overlapping_arms<'tcx>(cx: &LateContext<'tcx>, ex: &'tcx Expr<'_>, arms } } -fn check_wild_err_arm(cx: &LateContext<'_>, ex: &Expr<'_>, arms: &[Arm<'_>]) { +fn check_wild_err_arm<'tcx>(cx: &LateContext<'tcx>, ex: &Expr<'tcx>, arms: &[Arm<'tcx>]) { let ex_ty = cx.typeck_results().expr_ty(ex).peel_refs(); if is_type_diagnostic_item(cx, ex_ty, sym::result_type) { for arm in arms { @@ -922,8 +923,10 @@ fn check_wild_err_arm(cx: &LateContext<'_>, ex: &Expr<'_>, arms: &[Arm<'_>]) { if !matching_wild { // Looking for unused bindings (i.e.: `_e`) inner.iter().for_each(|pat| { - if let PatKind::Binding(.., ident, None) = &pat.kind { - if ident.as_str().starts_with('_') && is_unused(ident, arm.body) { + if let PatKind::Binding(_, id, ident, None) = pat.kind { + if ident.as_str().starts_with('_') + && !LocalUsedVisitor::new(cx, id).check_expr(arm.body) + { ident_bind_name = (&ident.name.as_str()).to_string(); matching_wild = true; } diff --git a/src/tools/clippy/clippy_lints/src/methods/bytes_nth.rs b/src/tools/clippy/clippy_lints/src/methods/bytes_nth.rs new file mode 100644 index 00000000000..defc50ede22 --- /dev/null +++ b/src/tools/clippy/clippy_lints/src/methods/bytes_nth.rs @@ -0,0 +1,39 @@ +use crate::utils::{is_type_diagnostic_item, snippet_with_applicability, span_lint_and_sugg}; +use if_chain::if_chain; +use rustc_errors::Applicability; +use rustc_hir::{Expr, ExprKind}; +use rustc_lint::LateContext; +use rustc_span::sym; + +use super::BYTES_NTH; + +pub(super) fn lints<'tcx>(cx: &LateContext<'tcx>, expr: &Expr<'_>, iter_args: &'tcx [Expr<'tcx>]) { + if_chain! { + if let ExprKind::MethodCall(_, _, ref args, _) = expr.kind; + let ty = cx.typeck_results().expr_ty(&iter_args[0]).peel_refs(); + let caller_type = if is_type_diagnostic_item(cx, ty, sym::string_type) { + Some("String") + } else if ty.is_str() { + Some("str") + } else { + None + }; + if let Some(caller_type) = caller_type; + then { + let mut applicability = Applicability::MachineApplicable; + span_lint_and_sugg( + cx, + BYTES_NTH, + expr.span, + &format!("called `.byte().nth()` on a `{}`", caller_type), + "try", + format!( + "{}.as_bytes().get({})", + snippet_with_applicability(cx, iter_args[0].span, "..", &mut applicability), + snippet_with_applicability(cx, args[1].span, "..", &mut applicability) + ), + applicability, + ); + } + } +} diff --git a/src/tools/clippy/clippy_lints/src/methods/filter_map_identity.rs b/src/tools/clippy/clippy_lints/src/methods/filter_map_identity.rs new file mode 100644 index 00000000000..9e646360a40 --- /dev/null +++ b/src/tools/clippy/clippy_lints/src/methods/filter_map_identity.rs @@ -0,0 +1,52 @@ +use crate::utils::{match_qpath, match_trait_method, path_to_local_id, paths, span_lint_and_sugg}; +use if_chain::if_chain; +use rustc_errors::Applicability; +use rustc_hir as hir; +use rustc_lint::LateContext; +use rustc_span::source_map::Span; + +use super::FILTER_MAP_IDENTITY; + +pub(super) fn check( + cx: &LateContext<'_>, + expr: &hir::Expr<'_>, + filter_map_args: &[hir::Expr<'_>], + filter_map_span: Span, +) { + if match_trait_method(cx, expr, &paths::ITERATOR) { + let arg_node = &filter_map_args[1].kind; + + let apply_lint = |message: &str| { + span_lint_and_sugg( + cx, + FILTER_MAP_IDENTITY, + filter_map_span.with_hi(expr.span.hi()), + message, + "try", + "flatten()".to_string(), + Applicability::MachineApplicable, + ); + }; + + if_chain! { + if let hir::ExprKind::Closure(_, _, body_id, _, _) = arg_node; + let body = cx.tcx.hir().body(*body_id); + + if let hir::PatKind::Binding(_, binding_id, ..) = body.params[0].pat.kind; + if path_to_local_id(&body.value, binding_id); + then { + apply_lint("called `filter_map(|x| x)` on an `Iterator`"); + } + } + + if_chain! { + if let hir::ExprKind::Path(ref qpath) = arg_node; + + if match_qpath(qpath, &paths::STD_CONVERT_IDENTITY); + + then { + apply_lint("called `filter_map(std::convert::identity)` on an `Iterator`"); + } + } + } +} diff --git a/src/tools/clippy/clippy_lints/src/methods/mod.rs b/src/tools/clippy/clippy_lints/src/methods/mod.rs index 0918843294d..433f513b1a8 100644 --- a/src/tools/clippy/clippy_lints/src/methods/mod.rs +++ b/src/tools/clippy/clippy_lints/src/methods/mod.rs @@ -1,4 +1,6 @@ mod bind_instead_of_map; +mod bytes_nth; +mod filter_map_identity; mod inefficient_to_string; mod inspect_for_each; mod manual_saturating_arithmetic; @@ -15,8 +17,7 @@ use if_chain::if_chain; use rustc_ast::ast; use rustc_errors::Applicability; use rustc_hir as hir; -use rustc_hir::def::Res; -use rustc_hir::{Expr, ExprKind, PatKind, QPath, TraitItem, TraitItemKind, UnOp}; +use rustc_hir::{Expr, ExprKind, PatKind, TraitItem, TraitItemKind, UnOp}; use rustc_lint::{LateContext, LateLintPass, Lint, LintContext}; use rustc_middle::lint::in_external_macro; use rustc_middle::ty::{self, TraitRef, Ty, TyS}; @@ -30,12 +31,12 @@ use crate::consts::{constant, Constant}; use crate::utils::eager_or_lazy::is_lazyness_candidate; use crate::utils::usage::mutated_variables; use crate::utils::{ - contains_return, contains_ty, get_arg_name, get_parent_expr, get_trait_def_id, has_iter_method, higher, - implements_trait, in_macro, is_copy, is_expn_of, is_type_diagnostic_item, iter_input_pats, last_path_segment, - match_def_path, match_qpath, match_trait_method, match_type, match_var, meets_msrv, method_calls, - method_chain_args, paths, remove_blocks, return_ty, single_segment_path, snippet, snippet_with_applicability, - snippet_with_macro_callsite, span_lint, span_lint_and_help, span_lint_and_sugg, span_lint_and_then, sugg, - walk_ptrs_ty_depth, SpanlessEq, + contains_return, contains_ty, get_parent_expr, get_trait_def_id, has_iter_method, higher, implements_trait, + in_macro, is_copy, is_expn_of, is_type_diagnostic_item, iter_input_pats, last_path_segment, match_def_path, + match_qpath, match_trait_method, match_type, meets_msrv, method_calls, method_chain_args, path_to_local_id, paths, + remove_blocks, return_ty, single_segment_path, snippet, snippet_with_applicability, snippet_with_macro_callsite, + span_lint, span_lint_and_help, span_lint_and_sugg, span_lint_and_then, strip_pat_refs, sugg, walk_ptrs_ty_depth, + SpanlessEq, }; declare_clippy_lint! { @@ -1467,6 +1468,51 @@ declare_clippy_lint! { "using `.inspect().for_each()`, which can be replaced with `.for_each()`" } +declare_clippy_lint! { + /// **What it does:** Checks for usage of `filter_map(|x| x)`. + /// + /// **Why is this bad?** Readability, this can be written more concisely by using `flatten`. + /// + /// **Known problems:** None. + /// + /// **Example:** + /// + /// ```rust + /// # let iter = vec![Some(1)].into_iter(); + /// iter.filter_map(|x| x); + /// ``` + /// Use instead: + /// ```rust + /// # let iter = vec![Some(1)].into_iter(); + /// iter.flatten(); + /// ``` + pub FILTER_MAP_IDENTITY, + complexity, + "call to `filter_map` where `flatten` is sufficient" +} + +declare_clippy_lint! { + /// **What it does:** Checks for the use of `.bytes().nth()`. + /// + /// **Why is this bad?** `.as_bytes().get()` is more efficient and more + /// readable. + /// + /// **Known problems:** None. + /// + /// **Example:** + /// + /// ```rust + /// // Bad + /// let _ = "Hello".bytes().nth(3); + /// + /// // Good + /// let _ = "Hello".as_bytes().get(3); + /// ``` + pub BYTES_NTH, + style, + "replace `.bytes().nth()` with `.as_bytes().get()`" +} + pub struct Methods { msrv: Option<RustcVersion>, } @@ -1504,6 +1550,7 @@ impl_lint_pass!(Methods => [ FILTER_NEXT, SKIP_WHILE_NEXT, FILTER_MAP, + FILTER_MAP_IDENTITY, MANUAL_FILTER_MAP, MANUAL_FIND_MAP, FILTER_MAP_NEXT, @@ -1513,6 +1560,7 @@ impl_lint_pass!(Methods => [ ITER_NEXT_SLICE, ITER_NTH, ITER_NTH_ZERO, + BYTES_NTH, ITER_SKIP_NEXT, GET_UNWRAP, STRING_EXTEND_CHARS, @@ -1590,6 +1638,7 @@ impl<'tcx> LateLintPass<'tcx> for Methods { ["extend", ..] => lint_extend(cx, expr, arg_lists[0]), ["nth", "iter"] => lint_iter_nth(cx, expr, &arg_lists, false), ["nth", "iter_mut"] => lint_iter_nth(cx, expr, &arg_lists, true), + ["nth", "bytes"] => bytes_nth::lints(cx, expr, &arg_lists[1]), ["nth", ..] => lint_iter_nth_zero(cx, expr, arg_lists[0]), ["step_by", ..] => lint_step_by(cx, expr, arg_lists[0]), ["next", "skip"] => lint_iter_skip_next(cx, expr, arg_lists[1]), @@ -1597,7 +1646,10 @@ impl<'tcx> LateLintPass<'tcx> for Methods { ["as_ref"] => lint_asref(cx, expr, "as_ref", arg_lists[0]), ["as_mut"] => lint_asref(cx, expr, "as_mut", arg_lists[0]), ["fold", ..] => lint_unnecessary_fold(cx, expr, arg_lists[0], method_spans[0]), - ["filter_map", ..] => unnecessary_filter_map::lint(cx, expr, arg_lists[0]), + ["filter_map", ..] => { + unnecessary_filter_map::lint(cx, expr, arg_lists[0]); + filter_map_identity::check(cx, expr, arg_lists[0], method_spans[0]); + }, ["count", "map"] => lint_suspicious_map(cx, expr), ["assume_init"] => lint_maybe_uninit(cx, &arg_lists[0][0], expr), ["unwrap_or", arith @ ("checked_add" | "checked_sub" | "checked_mul")] => { @@ -2183,7 +2235,10 @@ fn lint_expect_fun_call( span_replace_word, &format!("use of `{}` followed by a function call", name), "try this", - format!("unwrap_or_else({} {{ panic!(\"{{}}\", {}) }})", closure_args, arg_root_snippet), + format!( + "unwrap_or_else({} {{ panic!(\"{{}}\", {}) }})", + closure_args, arg_root_snippet + ), applicability, ); } @@ -2396,11 +2451,12 @@ fn lint_unnecessary_fold(cx: &LateContext<'_>, expr: &hir::Expr<'_>, fold_args: if bin_op.node == op; // Extract the names of the two arguments to the closure - if let Some(first_arg_ident) = get_arg_name(&closure_body.params[0].pat); - if let Some(second_arg_ident) = get_arg_name(&closure_body.params[1].pat); + if let [param_a, param_b] = closure_body.params; + if let PatKind::Binding(_, first_arg_id, ..) = strip_pat_refs(¶m_a.pat).kind; + if let PatKind::Binding(_, second_arg_id, second_arg_ident, _) = strip_pat_refs(¶m_b.pat).kind; - if match_var(&*left_expr, first_arg_ident); - if replacement_has_args || match_var(&*right_expr, second_arg_ident); + if path_to_local_id(left_expr, first_arg_id); + if replacement_has_args || path_to_local_id(right_expr, second_arg_id); then { let mut applicability = Applicability::MachineApplicable; @@ -3068,10 +3124,8 @@ fn lint_filter_map<'tcx>(cx: &LateContext<'tcx>, expr: &'tcx hir::Expr<'_>, is_f }; // let the filter closure arg and the map closure arg be equal if_chain! { - if let ExprKind::Path(QPath::Resolved(None, a_path)) = a_path.kind; - if let ExprKind::Path(QPath::Resolved(None, b_path)) = b.kind; - if a_path.res == Res::Local(filter_param_id); - if b_path.res == Res::Local(map_param_id); + if path_to_local_id(a_path, filter_param_id); + if path_to_local_id(b, map_param_id); if TyS::same_type(cx.typeck_results().expr_ty_adjusted(a), cx.typeck_results().expr_ty_adjusted(b)); then { return true; @@ -3255,8 +3309,9 @@ fn lint_search_is_some<'tcx>( then { if let hir::PatKind::Ref(..) = closure_arg.pat.kind { Some(search_snippet.replacen('&', "", 1)) - } else if let Some(name) = get_arg_name(&closure_arg.pat) { - Some(search_snippet.replace(&format!("*{}", name), &name.as_str())) + } else if let PatKind::Binding(_, _, ident, _) = strip_pat_refs(&closure_arg.pat).kind { + let name = &*ident.name.as_str(); + Some(search_snippet.replace(&format!("*{}", name), name)) } else { None } @@ -3688,9 +3743,7 @@ fn lint_option_as_ref_deref<'tcx>( hir::ExprKind::MethodCall(_, _, args, _) => { if_chain! { if args.len() == 1; - if let hir::ExprKind::Path(qpath) = &args[0].kind; - if let hir::def::Res::Local(local_id) = cx.qpath_res(qpath, args[0].hir_id); - if closure_body.params[0].pat.hir_id == local_id; + if path_to_local_id(&args[0], closure_body.params[0].pat.hir_id); let adj = cx .typeck_results() .expr_adjustments(&args[0]) @@ -3710,10 +3763,8 @@ fn lint_option_as_ref_deref<'tcx>( if_chain! { if let hir::ExprKind::Unary(hir::UnOp::Deref, ref inner1) = inner.kind; if let hir::ExprKind::Unary(hir::UnOp::Deref, ref inner2) = inner1.kind; - if let hir::ExprKind::Path(ref qpath) = inner2.kind; - if let hir::def::Res::Local(local_id) = cx.qpath_res(qpath, inner2.hir_id); then { - closure_body.params[0].pat.hir_id == local_id + path_to_local_id(inner2, closure_body.params[0].pat.hir_id) } else { false } @@ -4094,20 +4145,54 @@ fn lint_from_iter(cx: &LateContext<'_>, expr: &hir::Expr<'_>, args: &[hir::Expr< if implements_trait(cx, ty, from_iter_id, &[]) && implements_trait(cx, arg_ty, iter_id, &[]); then { // `expr` implements `FromIterator` trait - let iter_expr = snippet(cx, args[0].span, ".."); + let iter_expr = sugg::Sugg::hir(cx, &args[0], "..").maybe_par(); + let turbofish = extract_turbofish(cx, expr, ty); + let sugg = format!("{}.collect::<{}>()", iter_expr, turbofish); span_lint_and_sugg( cx, FROM_ITER_INSTEAD_OF_COLLECT, expr.span, "usage of `FromIterator::from_iter`", "use `.collect()` instead of `::from_iter()`", - format!("{}.collect()", iter_expr), + sugg, Applicability::MaybeIncorrect, ); } } } +fn extract_turbofish(cx: &LateContext<'_>, expr: &hir::Expr<'_>, ty: Ty<'tcx>) -> String { + if_chain! { + let call_site = expr.span.source_callsite(); + if let Ok(snippet) = cx.sess().source_map().span_to_snippet(call_site); + let snippet_split = snippet.split("::").collect::<Vec<_>>(); + if let Some((_, elements)) = snippet_split.split_last(); + + then { + // is there a type specifier? (i.e.: like `<u32>` in `collections::BTreeSet::<u32>::`) + if let Some(type_specifier) = snippet_split.iter().find(|e| e.starts_with('<') && e.ends_with('>')) { + // remove the type specifier from the path elements + let without_ts = elements.iter().filter_map(|e| { + if e == type_specifier { None } else { Some((*e).to_string()) } + }).collect::<Vec<_>>(); + // join and add the type specifier at the end (i.e.: `collections::BTreeSet<u32>`) + format!("{}{}", without_ts.join("::"), type_specifier) + } else { + // type is not explicitly specified so wildcards are needed + // i.e.: 2 wildcards in `std::collections::BTreeMap<&i32, &char>` + let ty_str = ty.to_string(); + let start = ty_str.find('<').unwrap_or(0); + let end = ty_str.find('>').unwrap_or_else(|| ty_str.len()); + let nb_wildcard = ty_str[start..end].split(',').count(); + let wildcards = format!("_{}", ", _".repeat(nb_wildcard - 1)); + format!("{}<{}>", elements.join("::"), wildcards) + } + } else { + ty.to_string() + } + } +} + fn fn_header_equals(expected: hir::FnHeader, actual: hir::FnHeader) -> bool { expected.constness == actual.constness && expected.unsafety == actual.unsafety diff --git a/src/tools/clippy/clippy_lints/src/methods/unnecessary_filter_map.rs b/src/tools/clippy/clippy_lints/src/methods/unnecessary_filter_map.rs index d98e6160d30..5691fcb88e9 100644 --- a/src/tools/clippy/clippy_lints/src/methods/unnecessary_filter_map.rs +++ b/src/tools/clippy/clippy_lints/src/methods/unnecessary_filter_map.rs @@ -1,8 +1,6 @@ -use crate::utils::paths; use crate::utils::usage::mutated_variables; -use crate::utils::{match_qpath, match_trait_method, span_lint}; +use crate::utils::{match_qpath, match_trait_method, path_to_local_id, paths, span_lint}; use rustc_hir as hir; -use rustc_hir::def::Res; use rustc_hir::intravisit::{walk_expr, NestedVisitorMap, Visitor}; use rustc_lint::LateContext; use rustc_middle::hir::map::Map; @@ -59,14 +57,8 @@ fn check_expression<'tcx>(cx: &LateContext<'tcx>, arg_id: hir::HirId, expr: &'tc if let hir::ExprKind::Path(ref path) = func.kind; then { if match_qpath(path, &paths::OPTION_SOME) { - if_chain! { - if let hir::ExprKind::Path(path) = &args[0].kind; - if let Res::Local(ref local) = cx.qpath_res(path, args[0].hir_id); - then { - if arg_id == *local { - return (false, false) - } - } + if path_to_local_id(&args[0], arg_id) { + return (false, false) } return (true, false); } diff --git a/src/tools/clippy/clippy_lints/src/mut_mut.rs b/src/tools/clippy/clippy_lints/src/mut_mut.rs index 2f3cdb894f0..d7239b328bb 100644 --- a/src/tools/clippy/clippy_lints/src/mut_mut.rs +++ b/src/tools/clippy/clippy_lints/src/mut_mut.rs @@ -52,7 +52,7 @@ impl<'a, 'tcx> intravisit::Visitor<'tcx> for MutVisitor<'a, 'tcx> { return; } - if let Some((_, arg, body)) = higher::for_loop(expr) { + if let Some((_, arg, body, _)) = higher::for_loop(expr) { // A `for` loop lowers to: // ```rust // match ::std::iter::Iterator::next(&mut iter) { diff --git a/src/tools/clippy/clippy_lints/src/needless_question_mark.rs b/src/tools/clippy/clippy_lints/src/needless_question_mark.rs index 9e9b79ee1cf..fe8d4d07abc 100644 --- a/src/tools/clippy/clippy_lints/src/needless_question_mark.rs +++ b/src/tools/clippy/clippy_lints/src/needless_question_mark.rs @@ -1,8 +1,6 @@ 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; @@ -160,7 +158,7 @@ fn is_some_or_ok_call<'a>( // 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); + if utils::is_some_ctor(cx, path.res) || utils::is_ok_ctor(cx, path.res); // Extract inner expression from ARGUMENT if let ExprKind::Match(inner_expr_with_q, _, MatchSource::TryDesugar) = &args[0].kind; @@ -208,25 +206,3 @@ fn is_some_or_ok_call<'a>( 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/src/tools/clippy/clippy_lints/src/ranges.rs b/src/tools/clippy/clippy_lints/src/ranges.rs index 3e454eecd97..59503817c0f 100644 --- a/src/tools/clippy/clippy_lints/src/ranges.rs +++ b/src/tools/clippy/clippy_lints/src/ranges.rs @@ -442,7 +442,7 @@ fn check_reversed_empty_range(cx: &LateContext<'_>, expr: &Expr<'_>) { let mut cur_expr = expr; while let Some(parent_expr) = get_parent_expr(cx, cur_expr) { match higher::for_loop(parent_expr) { - Some((_, args, _)) if args.hir_id == expr.hir_id => return true, + Some((_, args, _, _)) if args.hir_id == expr.hir_id => return true, _ => cur_expr = parent_expr, } } diff --git a/src/tools/clippy/clippy_lints/src/regex.rs b/src/tools/clippy/clippy_lints/src/regex.rs index d06ab143482..1edea613148 100644 --- a/src/tools/clippy/clippy_lints/src/regex.rs +++ b/src/tools/clippy/clippy_lints/src/regex.rs @@ -35,14 +35,16 @@ declare_clippy_lint! { /// `str::starts_with`, `str::ends_with` or `std::contains` or other `str` /// methods. /// - /// **Known problems:** None. + /// **Known problems:** If the same regex is going to be applied to multiple + /// inputs, the precomputations done by `Regex` construction can give + /// significantly better performance than any of the `str`-based methods. /// /// **Example:** /// ```ignore /// Regex::new("^foobar") /// ``` pub TRIVIAL_REGEX, - style, + nursery, "trivial regular expressions" } diff --git a/src/tools/clippy/clippy_lints/src/semicolon_if_nothing_returned.rs b/src/tools/clippy/clippy_lints/src/semicolon_if_nothing_returned.rs new file mode 100644 index 00000000000..839c995e525 --- /dev/null +++ b/src/tools/clippy/clippy_lints/src/semicolon_if_nothing_returned.rs @@ -0,0 +1,66 @@ +use crate::utils::{in_macro, snippet_with_macro_callsite, span_lint_and_sugg, sugg}; +use if_chain::if_chain; +use rustc_errors::Applicability; +use rustc_hir::{Block, ExprKind}; +use rustc_lint::{LateContext, LateLintPass}; +use rustc_session::{declare_lint_pass, declare_tool_lint}; + +declare_clippy_lint! { + /// **What it does:** Looks for blocks of expressions and fires if the last expression returns `()` + /// but is not followed by a semicolon. + /// + /// **Why is this bad?** The semicolon might be optional but when + /// extending the block with new code, it doesn't require a change in previous last line. + /// + /// **Known problems:** None. + /// + /// **Example:** + /// + /// ```rust + /// fn main() { + /// println!("Hello world") + /// } + /// ``` + /// Use instead: + /// ```rust + /// fn main() { + /// println!("Hello world"); + /// } + /// ``` + pub SEMICOLON_IF_NOTHING_RETURNED, + restriction, + "add a semicolon if nothing is returned" +} + +declare_lint_pass!(SemicolonIfNothingReturned => [SEMICOLON_IF_NOTHING_RETURNED]); + +impl LateLintPass<'_> for SemicolonIfNothingReturned { + fn check_block(&mut self, cx: &LateContext<'tcx>, block: &'tcx Block<'tcx>) { + if_chain! { + if !in_macro(block.span); + if let Some(expr) = block.expr; + let t_expr = cx.typeck_results().expr_ty(expr); + if t_expr.is_unit(); + if let snippet = snippet_with_macro_callsite(cx, expr.span, "}"); + if !snippet.ends_with('}'); + then { + // filter out the desugared `for` loop + if let ExprKind::DropTemps(..) = &expr.kind { + return; + } + + let sugg = sugg::Sugg::hir_with_macro_callsite(cx, &expr, ".."); + let suggestion = format!("{0};", sugg); + span_lint_and_sugg( + cx, + SEMICOLON_IF_NOTHING_RETURNED, + expr.span.source_callsite(), + "consider adding a `;` to the last statement for consistent formatting", + "add a `;` here", + suggestion, + Applicability::MaybeIncorrect, + ); + } + } + } +} diff --git a/src/tools/clippy/clippy_lints/src/to_string_in_display.rs b/src/tools/clippy/clippy_lints/src/to_string_in_display.rs index fa508df865e..fdd105e6246 100644 --- a/src/tools/clippy/clippy_lints/src/to_string_in_display.rs +++ b/src/tools/clippy/clippy_lints/src/to_string_in_display.rs @@ -1,6 +1,5 @@ -use crate::utils::{match_def_path, match_trait_method, paths, span_lint}; +use crate::utils::{match_def_path, match_trait_method, path_to_local_id, paths, span_lint}; use if_chain::if_chain; -use rustc_hir::def::Res; 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}; @@ -89,14 +88,12 @@ impl LateLintPass<'_> for ToStringInDisplay { fn check_expr(&mut self, cx: &LateContext<'_>, expr: &Expr<'_>) { if_chain! { + if self.in_display_impl; + if let Some(self_hir_id) = self.self_hir_id; if let ExprKind::MethodCall(ref path, _, args, _) = expr.kind; if path.ident.name == sym!(to_string); if match_trait_method(cx, expr, &paths::TO_STRING); - if self.in_display_impl; - if let ExprKind::Path(ref qpath) = args[0].kind; - if let Res::Local(hir_id) = cx.qpath_res(qpath, args[0].hir_id); - if let Some(self_hir_id) = self.self_hir_id; - if hir_id == self_hir_id; + if path_to_local_id(&args[0], self_hir_id); then { span_lint( cx, diff --git a/src/tools/clippy/clippy_lints/src/unused_self.rs b/src/tools/clippy/clippy_lints/src/unused_self.rs index 5349c4f7eb8..9d61bd0cc2f 100644 --- a/src/tools/clippy/clippy_lints/src/unused_self.rs +++ b/src/tools/clippy/clippy_lints/src/unused_self.rs @@ -1,12 +1,10 @@ use if_chain::if_chain; -use rustc_hir::def::Res; -use rustc_hir::intravisit::{walk_path, NestedVisitorMap, Visitor}; -use rustc_hir::{HirId, Impl, ImplItem, ImplItemKind, ItemKind, Path}; +use rustc_hir::{Impl, ImplItem, ImplItemKind, ItemKind}; use rustc_lint::{LateContext, LateLintPass}; -use rustc_middle::hir::map::Map; use rustc_session::{declare_lint_pass, declare_tool_lint}; use crate::utils::span_lint_and_help; +use crate::utils::visitors::LocalUsedVisitor; declare_clippy_lint! { /// **What it does:** Checks methods that contain a `self` argument but don't use it @@ -57,13 +55,7 @@ impl<'tcx> LateLintPass<'tcx> for UnusedSelf { then { let self_param = &body.params[0]; let self_hir_id = self_param.pat.hir_id; - let mut visitor = UnusedSelfVisitor { - cx, - uses_self: false, - self_hir_id: &self_hir_id, - }; - visitor.visit_body(body); - if !visitor.uses_self { + if !LocalUsedVisitor::new(cx, self_hir_id).check_body(body) { span_lint_and_help( cx, UNUSED_SELF, @@ -78,28 +70,3 @@ impl<'tcx> LateLintPass<'tcx> for UnusedSelf { } } } - -struct UnusedSelfVisitor<'a, 'tcx> { - cx: &'a LateContext<'tcx>, - uses_self: bool, - self_hir_id: &'a HirId, -} - -impl<'a, 'tcx> Visitor<'tcx> for UnusedSelfVisitor<'a, 'tcx> { - type Map = Map<'tcx>; - - fn visit_path(&mut self, path: &'tcx Path<'_>, _id: HirId) { - if self.uses_self { - // This function already uses `self` - return; - } - if let Res::Local(hir_id) = &path.res { - self.uses_self = self.self_hir_id == hir_id - } - walk_path(self, path); - } - - fn nested_visit_map(&mut self) -> NestedVisitorMap<Self::Map> { - NestedVisitorMap::OnlyBodies(self.cx.tcx.hir()) - } -} diff --git a/src/tools/clippy/clippy_lints/src/utils/conf.rs b/src/tools/clippy/clippy_lints/src/utils/conf.rs index b5a8300376c..7d7b35c2168 100644 --- a/src/tools/clippy/clippy_lints/src/utils/conf.rs +++ b/src/tools/clippy/clippy_lints/src/utils/conf.rs @@ -169,10 +169,12 @@ define_Conf! { (max_fn_params_bools, "max_fn_params_bools": u64, 3), /// Lint: WILDCARD_IMPORTS. Whether to allow certain wildcard imports (prelude, super in tests). (warn_on_all_wildcard_imports, "warn_on_all_wildcard_imports": bool, false), - /// Lint: DISALLOWED_METHOD. The list of blacklisted methods to lint about. NB: `bar` is not here since it has legitimate uses + /// Lint: DISALLOWED_METHOD. The list of disallowed methods, written as fully qualified paths. (disallowed_methods, "disallowed_methods": Vec<String>, Vec::<String>::new()), /// Lint: UNREADABLE_LITERAL. Should the fraction of a decimal be linted to include separators. (unreadable_literal_lint_fractions, "unreadable_literal_lint_fractions": bool, true), + /// Lint: _CARGO_COMMON_METADATA. For internal testing only, ignores the current `publish` settings in the Cargo manifest. + (cargo_ignore_publish, "cargo_ignore_publish": bool, false), } impl Default for Conf { diff --git a/src/tools/clippy/clippy_lints/src/utils/higher.rs b/src/tools/clippy/clippy_lints/src/utils/higher.rs index 145703d1bdc..1cf1aa363d5 100644 --- a/src/tools/clippy/clippy_lints/src/utils/higher.rs +++ b/src/tools/clippy/clippy_lints/src/utils/higher.rs @@ -9,6 +9,7 @@ use rustc_ast::ast; use rustc_hir as hir; use rustc_hir::{BorrowKind, Expr, ExprKind, StmtKind, UnOp}; use rustc_lint::LateContext; +use rustc_span::source_map::Span; /// Converts a hir binary operator to the corresponding `ast` type. #[must_use] @@ -133,11 +134,11 @@ pub fn is_from_for_desugar(local: &hir::Local<'_>) -> bool { false } -/// Recover the essential nodes of a desugared for loop: -/// `for pat in arg { body }` becomes `(pat, arg, body)`. +/// Recover the essential nodes of a desugared for loop as well as the entire span: +/// `for pat in arg { body }` becomes `(pat, arg, body)`. Return `(pat, arg, body, span)`. pub fn for_loop<'tcx>( expr: &'tcx hir::Expr<'tcx>, -) -> Option<(&hir::Pat<'_>, &'tcx hir::Expr<'tcx>, &'tcx hir::Expr<'tcx>)> { +) -> Option<(&hir::Pat<'_>, &'tcx hir::Expr<'tcx>, &'tcx hir::Expr<'tcx>, Span)> { if_chain! { if let hir::ExprKind::Match(ref iterexpr, ref arms, hir::MatchSource::ForLoopDesugar) = expr.kind; if let hir::ExprKind::Call(_, ref iterargs) = iterexpr.kind; @@ -148,7 +149,7 @@ pub fn for_loop<'tcx>( if let hir::StmtKind::Local(ref local) = let_stmt.kind; if let hir::StmtKind::Expr(ref expr) = body.kind; then { - return Some((&*local.pat, &iterargs[0], expr)); + return Some((&*local.pat, &iterargs[0], expr, arms[0].span)); } } None diff --git a/src/tools/clippy/clippy_lints/src/utils/internal_lints.rs b/src/tools/clippy/clippy_lints/src/utils/internal_lints.rs index ff3be590317..d8c602fab22 100644 --- a/src/tools/clippy/clippy_lints/src/utils/internal_lints.rs +++ b/src/tools/clippy/clippy_lints/src/utils/internal_lints.rs @@ -841,15 +841,13 @@ pub fn check_path(cx: &LateContext<'_>, path: &[&str]) -> bool { // implementations of native types. Check lang items. let path_syms: Vec<_> = path.iter().map(|p| Symbol::intern(p)).collect(); let lang_items = cx.tcx.lang_items(); - for lang_item in lang_items.items() { - if let Some(def_id) = lang_item { - let lang_item_path = cx.get_def_path(*def_id); - if path_syms.starts_with(&lang_item_path) { - if let [item] = &path_syms[lang_item_path.len()..] { - for child in cx.tcx.item_children(*def_id) { - if child.ident.name == *item { - return true; - } + for item_def_id in lang_items.items().iter().flatten() { + let lang_item_path = cx.get_def_path(*item_def_id); + if path_syms.starts_with(&lang_item_path) { + if let [item] = &path_syms[lang_item_path.len()..] { + for child in cx.tcx.item_children(*item_def_id) { + if child.ident.name == *item { + return true; } } } diff --git a/src/tools/clippy/clippy_lints/src/utils/mod.rs b/src/tools/clippy/clippy_lints/src/utils/mod.rs index de1538233a8..fafa1400156 100644 --- a/src/tools/clippy/clippy_lints/src/utils/mod.rs +++ b/src/tools/clippy/clippy_lints/src/utils/mod.rs @@ -36,7 +36,7 @@ use rustc_ast::ast::{self, Attribute, LitKind}; use rustc_data_structures::fx::FxHashMap; use rustc_errors::Applicability; use rustc_hir as hir; -use rustc_hir::def::{DefKind, Res}; +use rustc_hir::def::{CtorKind, CtorOf, DefKind, Res}; use rustc_hir::def_id::{DefId, LOCAL_CRATE}; use rustc_hir::intravisit::{self, NestedVisitorMap, Visitor}; use rustc_hir::Node; @@ -49,7 +49,7 @@ use rustc_lint::{LateContext, Level, Lint, LintContext}; use rustc_middle::hir::exports::Export; use rustc_middle::hir::map::Map; use rustc_middle::ty::subst::{GenericArg, GenericArgKind}; -use rustc_middle::ty::{self, layout::IntegerExt, Ty, TyCtxt, TypeFoldable}; +use rustc_middle::ty::{self, layout::IntegerExt, DefIdTree, Ty, TyCtxt, TypeFoldable}; use rustc_semver::RustcVersion; use rustc_session::Session; use rustc_span::hygiene::{ExpnKind, MacroKind}; @@ -306,6 +306,22 @@ pub fn match_path_ast(path: &ast::Path, segments: &[&str]) -> bool { .all(|(a, b)| a.ident.name.as_str() == *b) } +/// If the expression is a path to a local, returns the canonical `HirId` of the local. +pub fn path_to_local(expr: &Expr<'_>) -> Option<HirId> { + if let ExprKind::Path(QPath::Resolved(None, ref path)) = expr.kind { + if let Res::Local(id) = path.res { + return Some(id); + } + } + None +} + +/// Returns true if the expression is a path to a local with the specified `HirId`. +/// Use this function to see if an expression matches a function argument or a match binding. +pub fn path_to_local_id(expr: &Expr<'_>, id: HirId) -> bool { + path_to_local(expr) == Some(id) +} + /// Gets the definition associated to a path. #[allow(clippy::shadow_unrelated)] // false positive #6563 pub fn path_to_res(cx: &LateContext<'_>, path: &[&str]) -> Res { @@ -1134,9 +1150,7 @@ pub fn is_try<'tcx>(expr: &'tcx Expr<'tcx>) -> Option<&'tcx Expr<'tcx>> { if let PatKind::TupleStruct(ref path, ref pat, None) = arm.pat.kind; if match_qpath(path, &paths::RESULT_OK[1..]); if let PatKind::Binding(_, hir_id, _, None) = pat[0].kind; - if let ExprKind::Path(QPath::Resolved(None, ref path)) = arm.body.kind; - if let Res::Local(lid) = path.res; - if lid == hir_id; + if path_to_local_id(arm.body, hir_id); then { return true; } @@ -1180,12 +1194,11 @@ pub fn is_allowed(cx: &LateContext<'_>, lint: &'static Lint, id: HirId) -> bool cx.tcx.lint_level_at_node(lint, id).0 == Level::Allow } -pub fn get_arg_name(pat: &Pat<'_>) -> Option<Symbol> { - match pat.kind { - PatKind::Binding(.., ident, None) => Some(ident.name), - PatKind::Ref(ref subpat, _) => get_arg_name(subpat), - _ => None, +pub fn strip_pat_refs<'hir>(mut pat: &'hir Pat<'hir>) -> &'hir Pat<'hir> { + while let PatKind::Ref(subpat, _) = pat.kind { + pat = subpat; } + pat } pub fn int_bits(tcx: TyCtxt<'_>, ity: ty::IntTy) -> u64 { @@ -1702,6 +1715,30 @@ pub fn is_hir_ty_cfg_dependant(cx: &LateContext<'_>, ty: &hir::Ty<'_>) -> bool { } } +/// Check if the resolution of a given path is an `Ok` variant of `Result`. +pub 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 +} + +/// Check if the resolution of a given path is a `Some` variant of `Option`. +pub 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 +} + #[cfg(test)] mod test { use super::{reindent_multiline, without_block_comments}; diff --git a/src/tools/clippy/clippy_lints/src/utils/usage.rs b/src/tools/clippy/clippy_lints/src/utils/usage.rs index fc0db7f64ec..7c7580a2c66 100644 --- a/src/tools/clippy/clippy_lints/src/utils/usage.rs +++ b/src/tools/clippy/clippy_lints/src/utils/usage.rs @@ -1,16 +1,14 @@ use crate::utils; -use crate::utils::match_var; use rustc_data_structures::fx::FxHashSet; use rustc_hir as hir; use rustc_hir::def::Res; use rustc_hir::intravisit; -use rustc_hir::intravisit::{walk_expr, NestedVisitorMap, Visitor}; +use rustc_hir::intravisit::{NestedVisitorMap, Visitor}; use rustc_hir::{Expr, ExprKind, HirId, Path}; use rustc_infer::infer::TyCtxtInferExt; use rustc_lint::LateContext; use rustc_middle::hir::map::Map; use rustc_middle::ty; -use rustc_span::symbol::{Ident, Symbol}; use rustc_typeck::expr_use_visitor::{ConsumeMode, Delegate, ExprUseVisitor, PlaceBase, PlaceWithHirId}; /// Returns a set of mutated local variable IDs, or `None` if mutations could not be determined. @@ -81,36 +79,6 @@ impl<'tcx> Delegate<'tcx> for MutVarsDelegate { } } -pub struct UsedVisitor { - pub var: Symbol, // var to look for - pub used: bool, // has the var been used otherwise? -} - -impl<'tcx> Visitor<'tcx> for UsedVisitor { - type Map = Map<'tcx>; - - fn visit_expr(&mut self, expr: &'tcx Expr<'_>) { - if match_var(expr, self.var) { - self.used = true; - } else { - walk_expr(self, expr); - } - } - - fn nested_visit_map(&mut self) -> NestedVisitorMap<Self::Map> { - NestedVisitorMap::None - } -} - -pub fn is_unused<'tcx>(ident: &'tcx Ident, body: &'tcx Expr<'_>) -> bool { - let mut visitor = UsedVisitor { - var: ident.name, - used: false, - }; - walk_expr(&mut visitor, body); - !visitor.used -} - pub struct ParamBindingIdCollector { binding_hir_ids: Vec<hir::HirId>, } diff --git a/src/tools/clippy/clippy_lints/src/utils/visitors.rs b/src/tools/clippy/clippy_lints/src/utils/visitors.rs index ebf69df31ca..085c1f9c0cb 100644 --- a/src/tools/clippy/clippy_lints/src/utils/visitors.rs +++ b/src/tools/clippy/clippy_lints/src/utils/visitors.rs @@ -1,7 +1,7 @@ +use crate::utils::path_to_local_id; use rustc_hir as hir; -use rustc_hir::def::Res; use rustc_hir::intravisit::{self, walk_expr, NestedVisitorMap, Visitor}; -use rustc_hir::{Arm, Expr, ExprKind, HirId, QPath, Stmt}; +use rustc_hir::{Arm, Body, Expr, HirId, Stmt}; use rustc_lint::LateContext; use rustc_middle::hir::map::Map; @@ -133,14 +133,16 @@ where } } -pub struct LocalUsedVisitor { +pub struct LocalUsedVisitor<'hir> { + hir: Map<'hir>, pub local_hir_id: HirId, pub used: bool, } -impl LocalUsedVisitor { - pub fn new(local_hir_id: HirId) -> Self { +impl<'hir> LocalUsedVisitor<'hir> { + pub fn new(cx: &LateContext<'hir>, local_hir_id: HirId) -> Self { Self { + hir: cx.tcx.hir(), local_hir_id, used: false, } @@ -151,35 +153,38 @@ impl LocalUsedVisitor { std::mem::replace(&mut self.used, false) } - pub fn check_arm(&mut self, arm: &Arm<'_>) -> bool { + pub fn check_arm(&mut self, arm: &'hir Arm<'_>) -> bool { self.check(arm, Self::visit_arm) } - pub fn check_expr(&mut self, expr: &Expr<'_>) -> bool { + pub fn check_body(&mut self, body: &'hir Body<'_>) -> bool { + self.check(body, Self::visit_body) + } + + pub fn check_expr(&mut self, expr: &'hir Expr<'_>) -> bool { self.check(expr, Self::visit_expr) } - pub fn check_stmt(&mut self, stmt: &Stmt<'_>) -> bool { + pub fn check_stmt(&mut self, stmt: &'hir Stmt<'_>) -> bool { self.check(stmt, Self::visit_stmt) } } -impl<'v> Visitor<'v> for LocalUsedVisitor { +impl<'v> Visitor<'v> for LocalUsedVisitor<'v> { type Map = Map<'v>; fn visit_expr(&mut self, expr: &'v Expr<'v>) { - if let ExprKind::Path(QPath::Resolved(None, path)) = expr.kind { - if let Res::Local(id) = path.res { - if id == self.local_hir_id { - self.used = true; - return; - } - } + if self.used { + return; + } + if path_to_local_id(expr, self.local_hir_id) { + self.used = true; + } else { + walk_expr(self, expr); } - walk_expr(self, expr); } fn nested_visit_map(&mut self) -> NestedVisitorMap<Self::Map> { - NestedVisitorMap::None + NestedVisitorMap::OnlyBodies(self.hir) } } diff --git a/src/tools/clippy/clippy_lints/src/vec.rs b/src/tools/clippy/clippy_lints/src/vec.rs index 149cceb39dd..c132e4de4f6 100644 --- a/src/tools/clippy/clippy_lints/src/vec.rs +++ b/src/tools/clippy/clippy_lints/src/vec.rs @@ -55,7 +55,7 @@ impl<'tcx> LateLintPass<'tcx> for UselessVec { // search for `for _ in vec![…]` if_chain! { - if let Some((_, arg, _)) = higher::for_loop(expr); + if let Some((_, arg, _, _)) = higher::for_loop(expr); if let Some(vec_args) = higher::vec_macro(cx, arg); if is_copy(cx, vec_type(cx.typeck_results().expr_ty_adjusted(arg))); then { |