diff options
Diffstat (limited to 'clippy_lints/src')
| -rw-r--r-- | clippy_lints/src/lib.rs | 16 | ||||
| -rw-r--r-- | clippy_lints/src/loops.rs | 361 | ||||
| -rw-r--r-- | clippy_lints/src/manual_async_fn.rs | 159 | ||||
| -rw-r--r-- | clippy_lints/src/manual_non_exhaustive.rs | 173 | ||||
| -rw-r--r-- | clippy_lints/src/match_on_vec_items.rs | 23 | ||||
| -rw-r--r-- | clippy_lints/src/misc_early.rs | 21 | ||||
| -rw-r--r-- | clippy_lints/src/unwrap.rs | 21 | ||||
| -rw-r--r-- | clippy_lints/src/utils/conf.rs | 2 | ||||
| -rw-r--r-- | clippy_lints/src/utils/mod.rs | 34 | ||||
| -rw-r--r-- | clippy_lints/src/utils/paths.rs | 3 | ||||
| -rw-r--r-- | clippy_lints/src/wildcard_imports.rs | 74 |
11 files changed, 660 insertions, 227 deletions
diff --git a/clippy_lints/src/lib.rs b/clippy_lints/src/lib.rs index 1f135cba6e4..51b5401da7d 100644 --- a/clippy_lints/src/lib.rs +++ b/clippy_lints/src/lib.rs @@ -247,6 +247,8 @@ mod literal_representation; mod loops; mod macro_use; mod main_recursion; +mod manual_async_fn; +mod manual_non_exhaustive; mod map_clone; mod map_unit_fn; mod match_on_vec_items; @@ -628,6 +630,8 @@ pub fn register_plugins(store: &mut rustc_lint::LintStore, sess: &Session, conf: &loops::WHILE_LET_ON_ITERATOR, ¯o_use::MACRO_USE_IMPORTS, &main_recursion::MAIN_RECURSION, + &manual_async_fn::MANUAL_ASYNC_FN, + &manual_non_exhaustive::MANUAL_NON_EXHAUSTIVE, &map_clone::MAP_CLONE, &map_unit_fn::OPTION_MAP_UNIT_FN, &map_unit_fn::RESULT_MAP_UNIT_FN, @@ -1054,7 +1058,8 @@ pub fn register_plugins(store: &mut rustc_lint::LintStore, sess: &Session, conf: let max_struct_bools = conf.max_struct_bools; store.register_early_pass(move || box excessive_bools::ExcessiveBools::new(max_struct_bools, max_fn_params_bools)); store.register_early_pass(|| box option_env_unwrap::OptionEnvUnwrap); - store.register_late_pass(|| box wildcard_imports::WildcardImports); + let warn_on_all_wildcard_imports = conf.warn_on_all_wildcard_imports; + store.register_late_pass(move || box wildcard_imports::WildcardImports::new(warn_on_all_wildcard_imports)); store.register_early_pass(|| box macro_use::MacroUseImports); store.register_late_pass(|| box verbose_file_reads::VerboseFileReads); store.register_late_pass(|| box redundant_pub_crate::RedundantPubCrate::default()); @@ -1064,6 +1069,8 @@ pub fn register_plugins(store: &mut rustc_lint::LintStore, sess: &Session, conf: store.register_late_pass(|| box utils::internal_lints::CollapsibleCalls); store.register_late_pass(|| box if_let_mutex::IfLetMutex); store.register_late_pass(|| box match_on_vec_items::MatchOnVecItems); + store.register_early_pass(|| box manual_non_exhaustive::ManualNonExhaustive); + store.register_late_pass(|| box manual_async_fn::ManualAsyncFn); store.register_group(true, "clippy::restriction", Some("clippy_restriction"), vec![ LintId::of(&arithmetic::FLOAT_ARITHMETIC), @@ -1138,6 +1145,7 @@ pub fn register_plugins(store: &mut rustc_lint::LintStore, sess: &Session, conf: LintId::of(&loops::EXPLICIT_INTO_ITER_LOOP), LintId::of(&loops::EXPLICIT_ITER_LOOP), LintId::of(¯o_use::MACRO_USE_IMPORTS), + LintId::of(&match_on_vec_items::MATCH_ON_VEC_ITEMS), LintId::of(&matches::MATCH_BOOL), LintId::of(&matches::SINGLE_MATCH_ELSE), LintId::of(&methods::FILTER_MAP), @@ -1280,10 +1288,11 @@ pub fn register_plugins(store: &mut rustc_lint::LintStore, sess: &Session, conf: LintId::of(&loops::WHILE_LET_LOOP), LintId::of(&loops::WHILE_LET_ON_ITERATOR), LintId::of(&main_recursion::MAIN_RECURSION), + LintId::of(&manual_async_fn::MANUAL_ASYNC_FN), + LintId::of(&manual_non_exhaustive::MANUAL_NON_EXHAUSTIVE), LintId::of(&map_clone::MAP_CLONE), LintId::of(&map_unit_fn::OPTION_MAP_UNIT_FN), LintId::of(&map_unit_fn::RESULT_MAP_UNIT_FN), - LintId::of(&match_on_vec_items::MATCH_ON_VEC_ITEMS), LintId::of(&matches::INFALLIBLE_DESTRUCTURING_MATCH), LintId::of(&matches::MATCH_AS_REF), LintId::of(&matches::MATCH_OVERLAPPING_ARM), @@ -1474,6 +1483,8 @@ pub fn register_plugins(store: &mut rustc_lint::LintStore, sess: &Session, conf: LintId::of(&loops::NEEDLESS_RANGE_LOOP), LintId::of(&loops::WHILE_LET_ON_ITERATOR), LintId::of(&main_recursion::MAIN_RECURSION), + LintId::of(&manual_async_fn::MANUAL_ASYNC_FN), + LintId::of(&manual_non_exhaustive::MANUAL_NON_EXHAUSTIVE), LintId::of(&map_clone::MAP_CLONE), LintId::of(&matches::INFALLIBLE_DESTRUCTURING_MATCH), LintId::of(&matches::MATCH_OVERLAPPING_ARM), @@ -1647,7 +1658,6 @@ pub fn register_plugins(store: &mut rustc_lint::LintStore, sess: &Session, conf: LintId::of(&loops::NEVER_LOOP), LintId::of(&loops::REVERSE_RANGE_LOOP), LintId::of(&loops::WHILE_IMMUTABLE_CONDITION), - LintId::of(&match_on_vec_items::MATCH_ON_VEC_ITEMS), LintId::of(&mem_discriminant::MEM_DISCRIMINANT_NON_ENUM), LintId::of(&mem_replace::MEM_REPLACE_WITH_UNINIT), LintId::of(&methods::CLONE_DOUBLE_REF), diff --git a/clippy_lints/src/loops.rs b/clippy_lints/src/loops.rs index f7c7fd82d83..2bbf4dba614 100644 --- a/clippy_lints/src/loops.rs +++ b/clippy_lints/src/loops.rs @@ -10,7 +10,6 @@ use crate::utils::{ }; use crate::utils::{is_type_diagnostic_item, qpath_res, same_tys, sext, sugg}; use if_chain::if_chain; -use itertools::Itertools; use rustc_ast::ast; use rustc_data_structures::fx::{FxHashMap, FxHashSet}; use rustc_errors::Applicability; @@ -772,40 +771,48 @@ fn check_for_loop<'a, 'tcx>( fn same_var<'a, 'tcx>(cx: &LateContext<'a, 'tcx>, expr: &Expr<'_>, var: HirId) -> bool { if_chain! { - if let ExprKind::Path(ref qpath) = expr.kind; - if let QPath::Resolved(None, ref path) = *qpath; + 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) = qpath_res(cx, qpath, expr.hir_id); - // our variable! - if local_id == var; then { - return true; + // our variable! + local_id == var + } else { + false } } +} - false +#[derive(Clone, Copy)] +enum OffsetSign { + Positive, + Negative, } struct Offset { value: String, - negate: bool, + sign: OffsetSign, } impl Offset { - fn negative(s: String) -> Self { - Self { value: s, negate: true } + fn negative(value: String) -> Self { + Self { + value, + sign: OffsetSign::Negative, + } } - fn positive(s: String) -> Self { + fn positive(value: String) -> Self { Self { - value: s, - negate: false, + value, + sign: OffsetSign::Positive, } } } -struct FixedOffsetVar { - var_name: String, +struct FixedOffsetVar<'hir> { + var: &'hir Expr<'hir>, offset: Offset, } @@ -819,10 +826,20 @@ fn is_slice_like<'a, 'tcx>(cx: &LateContext<'a, 'tcx>, ty: Ty<'_>) -> bool { is_slice || is_type_diagnostic_item(cx, ty, sym!(vec_type)) || is_type_diagnostic_item(cx, ty, sym!(vecdeque_type)) } -fn get_fixed_offset_var<'a, 'tcx>(cx: &LateContext<'a, 'tcx>, expr: &Expr<'_>, var: HirId) -> Option<FixedOffsetVar> { +fn fetch_cloned_expr<'tcx>(expr: &'tcx Expr<'tcx>) -> &'tcx Expr<'tcx> { + if_chain! { + if let ExprKind::MethodCall(method, _, args) = expr.kind; + if method.ident.name == sym!(clone); + if args.len() == 1; + if let Some(arg) = args.get(0); + then { arg } else { expr } + } +} + +fn get_offset<'a, 'tcx>(cx: &LateContext<'a, 'tcx>, idx: &Expr<'_>, var: HirId) -> Option<Offset> { fn extract_offset<'a, 'tcx>(cx: &LateContext<'a, 'tcx>, e: &Expr<'_>, var: HirId) -> Option<String> { - match e.kind { - ExprKind::Lit(ref l) => match l.node { + match &e.kind { + ExprKind::Lit(l) => match l.node { ast::LitKind::Int(x, _ty) => Some(x.to_string()), _ => None, }, @@ -831,115 +848,139 @@ fn get_fixed_offset_var<'a, 'tcx>(cx: &LateContext<'a, 'tcx>, expr: &Expr<'_>, v } } - if let ExprKind::Index(ref seqexpr, ref idx) = expr.kind { - let ty = cx.tables.expr_ty(seqexpr); - if !is_slice_like(cx, ty) { - return None; - } - - let offset = match idx.kind { - ExprKind::Binary(op, ref lhs, ref rhs) => match op.node { - BinOpKind::Add => { - let offset_opt = if same_var(cx, lhs, var) { - extract_offset(cx, rhs, var) - } else if same_var(cx, rhs, var) { - extract_offset(cx, lhs, var) - } else { - None - }; - - offset_opt.map(Offset::positive) - }, - BinOpKind::Sub if same_var(cx, lhs, var) => extract_offset(cx, rhs, var).map(Offset::negative), - _ => None, - }, - ExprKind::Path(..) => { - if same_var(cx, idx, var) { - Some(Offset::positive("0".into())) + match idx.kind { + ExprKind::Binary(op, lhs, rhs) => match op.node { + BinOpKind::Add => { + let offset_opt = if same_var(cx, lhs, var) { + extract_offset(cx, rhs, var) + } else if same_var(cx, rhs, var) { + extract_offset(cx, lhs, var) } else { None - } + }; + + offset_opt.map(Offset::positive) }, + BinOpKind::Sub if same_var(cx, lhs, var) => extract_offset(cx, rhs, var).map(Offset::negative), _ => None, - }; - - offset.map(|o| FixedOffsetVar { - var_name: snippet_opt(cx, seqexpr.span).unwrap_or_else(|| "???".into()), - offset: o, - }) - } else { - None - } -} - -fn fetch_cloned_fixed_offset_var<'a, 'tcx>( - cx: &LateContext<'a, 'tcx>, - expr: &Expr<'_>, - var: HirId, -) -> Option<FixedOffsetVar> { - if_chain! { - if let ExprKind::MethodCall(ref method, _, ref args) = expr.kind; - if method.ident.name == sym!(clone); - if args.len() == 1; - if let Some(arg) = args.get(0); - then { - return get_fixed_offset_var(cx, arg, var); - } + }, + ExprKind::Path(..) if same_var(cx, idx, var) => Some(Offset::positive("0".into())), + _ => None, } - - get_fixed_offset_var(cx, expr, var) } -fn get_indexed_assignments<'a, 'tcx>( - cx: &LateContext<'a, 'tcx>, - body: &Expr<'_>, - var: HirId, -) -> Vec<(FixedOffsetVar, FixedOffsetVar)> { - fn get_assignment<'a, 'tcx>( - cx: &LateContext<'a, 'tcx>, - e: &Expr<'_>, - var: HirId, - ) -> Option<(FixedOffsetVar, FixedOffsetVar)> { - if let ExprKind::Assign(ref lhs, ref rhs, _) = e.kind { - match ( - get_fixed_offset_var(cx, lhs, var), - fetch_cloned_fixed_offset_var(cx, rhs, var), - ) { - (Some(offset_left), Some(offset_right)) => { - // Source and destination must be different - if offset_left.var_name == offset_right.var_name { - None - } else { - Some((offset_left, offset_right)) - } - }, - _ => None, - } +fn get_assignments<'tcx>(body: &'tcx Expr<'tcx>) -> impl Iterator<Item = Option<(&'tcx Expr<'tcx>, &'tcx Expr<'tcx>)>> { + fn get_assignment<'tcx>(e: &'tcx Expr<'tcx>) -> Option<(&'tcx Expr<'tcx>, &'tcx Expr<'tcx>)> { + if let ExprKind::Assign(lhs, rhs, _) = e.kind { + Some((lhs, rhs)) } else { None } } - if let ExprKind::Block(ref b, _) = body.kind { - let Block { - ref stmts, ref expr, .. - } = **b; + // This is one of few ways to return different iterators + // derived from: https://stackoverflow.com/questions/29760668/conditionally-iterate-over-one-of-several-possible-iterators/52064434#52064434 + let mut iter_a = None; + let mut iter_b = None; + + if let ExprKind::Block(b, _) = body.kind { + let Block { stmts, expr, .. } = *b; - stmts + iter_a = stmts .iter() - .map(|stmt| match stmt.kind { + .filter_map(|stmt| match stmt.kind { StmtKind::Local(..) | StmtKind::Item(..) => None, - StmtKind::Expr(ref e) | StmtKind::Semi(ref e) => Some(get_assignment(cx, e, var)), + StmtKind::Expr(e) | StmtKind::Semi(e) => Some(e), }) - .chain(expr.as_ref().into_iter().map(|e| Some(get_assignment(cx, &*e, var)))) - .filter_map(|op| op) - .collect::<Option<Vec<_>>>() - .unwrap_or_default() + .chain(expr.into_iter()) + .map(get_assignment) + .into() } else { - get_assignment(cx, body, var).into_iter().collect() + iter_b = Some(get_assignment(body)) } + + iter_a.into_iter().flatten().chain(iter_b.into_iter()) } +fn build_manual_memcpy_suggestion<'a, 'tcx>( + cx: &LateContext<'a, 'tcx>, + start: &Expr<'_>, + end: &Expr<'_>, + limits: ast::RangeLimits, + dst_var: FixedOffsetVar<'_>, + src_var: FixedOffsetVar<'_>, +) -> String { + fn print_sum(arg1: &str, arg2: &Offset) -> String { + match (arg1, &arg2.value[..], arg2.sign) { + ("0", "0", _) => "0".into(), + ("0", x, OffsetSign::Positive) | (x, "0", _) => x.into(), + ("0", x, OffsetSign::Negative) => format!("-{}", x), + (x, y, OffsetSign::Positive) => format!("({} + {})", x, y), + (x, y, OffsetSign::Negative) => { + if x == y { + "0".into() + } else { + format!("({} - {})", x, y) + } + }, + } + } + + fn print_offset(start_str: &str, inline_offset: &Offset) -> String { + let offset = print_sum(start_str, inline_offset); + if offset.as_str() == "0" { + "".into() + } else { + offset + } + } + + let print_limit = |end: &Expr<'_>, offset: Offset, var: &Expr<'_>| { + if_chain! { + if let ExprKind::MethodCall(method, _, len_args) = end.kind; + 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, var); + then { + match offset.sign { + OffsetSign::Negative => format!("({} - {})", snippet(cx, end.span, "<src>.len()"), offset.value), + OffsetSign::Positive => "".into(), + } + } else { + let end_str = match limits { + ast::RangeLimits::Closed => { + let end = sugg::Sugg::hir(cx, end, "<count>"); + format!("{}", end + sugg::ONE) + }, + ast::RangeLimits::HalfOpen => format!("{}", snippet(cx, end.span, "..")), + }; + + print_sum(&end_str, &offset) + } + } + }; + + let start_str = snippet(cx, start.span, "").to_string(); + let dst_offset = print_offset(&start_str, &dst_var.offset); + let dst_limit = print_limit(end, dst_var.offset, dst_var.var); + let src_offset = print_offset(&start_str, &src_var.offset); + let src_limit = print_limit(end, src_var.offset, src_var.var); + + let dst_var_name = snippet_opt(cx, dst_var.var.span).unwrap_or_else(|| "???".into()); + let src_var_name = snippet_opt(cx, src_var.var.span).unwrap_or_else(|| "???".into()); + + let dst = if dst_offset == "" && dst_limit == "" { + dst_var_name + } else { + format!("{}[{}..{}]", dst_var_name, dst_offset, dst_limit) + }; + + format!( + "{}.clone_from_slice(&{}[{}..{}])", + dst, src_var_name, src_offset, src_limit + ) +} /// Checks for for loops that sequentially copy items from one slice-like /// object to another. fn detect_manual_memcpy<'a, 'tcx>( @@ -951,93 +992,43 @@ fn detect_manual_memcpy<'a, 'tcx>( ) { if let Some(higher::Range { start: Some(start), - ref end, + end: Some(end), limits, }) = higher::range(cx, arg) { // the var must be a single name if let PatKind::Binding(_, canonical_id, _, _) = pat.kind { - let print_sum = |arg1: &Offset, arg2: &Offset| -> String { - match (&arg1.value[..], arg1.negate, &arg2.value[..], arg2.negate) { - ("0", _, "0", _) => "".into(), - ("0", _, x, false) | (x, false, "0", false) => x.into(), - ("0", _, x, true) | (x, false, "0", true) => format!("-{}", x), - (x, false, y, false) => format!("({} + {})", x, y), - (x, false, y, true) => { - if x == y { - "0".into() - } else { - format!("({} - {})", x, y) - } - }, - (x, true, y, false) => { - if x == y { - "0".into() - } else { - format!("({} - {})", y, x) - } - }, - (x, true, y, true) => format!("-({} + {})", x, y), - } - }; - - let print_limit = |end: &Option<&Expr<'_>>, offset: Offset, var_name: &str| { - if let Some(end) = *end { - if_chain! { - if let ExprKind::MethodCall(ref method, _, ref len_args) = end.kind; - if method.ident.name == sym!(len); - if len_args.len() == 1; - if let Some(arg) = len_args.get(0); - if snippet(cx, arg.span, "??") == var_name; - then { - return if offset.negate { - format!("({} - {})", snippet(cx, end.span, "<src>.len()"), offset.value) - } else { - String::new() - }; - } - } - - let end_str = match limits { - ast::RangeLimits::Closed => { - let end = sugg::Sugg::hir(cx, end, "<count>"); - format!("{}", end + sugg::ONE) - }, - ast::RangeLimits::HalfOpen => format!("{}", snippet(cx, end.span, "..")), - }; - - print_sum(&Offset::positive(end_str), &offset) - } else { - "..".into() - } - }; - // The only statements in the for loops can be indexed assignments from // indexed retrievals. - let manual_copies = get_indexed_assignments(cx, body, canonical_id); - - let big_sugg = manual_copies - .into_iter() - .map(|(dst_var, src_var)| { - let start_str = Offset::positive(snippet(cx, start.span, "").to_string()); - let dst_offset = print_sum(&start_str, &dst_var.offset); - let dst_limit = print_limit(end, dst_var.offset, &dst_var.var_name); - let src_offset = print_sum(&start_str, &src_var.offset); - let src_limit = print_limit(end, src_var.offset, &src_var.var_name); - let dst = if dst_offset == "" && dst_limit == "" { - dst_var.var_name - } else { - format!("{}[{}..{}]", dst_var.var_name, dst_offset, dst_limit) - }; - - format!( - "{}.clone_from_slice(&{}[{}..{}])", - dst, src_var.var_name, src_offset, src_limit - ) + let big_sugg = get_assignments(body) + .map(|o| { + o.and_then(|(lhs, rhs)| { + let rhs = fetch_cloned_expr(rhs); + if_chain! { + if let ExprKind::Index(seqexpr_left, idx_left) = lhs.kind; + if let ExprKind::Index(seqexpr_right, idx_right) = rhs.kind; + if is_slice_like(cx, cx.tables.expr_ty(seqexpr_left)) + && is_slice_like(cx, cx.tables.expr_ty(seqexpr_right)); + if let Some(offset_left) = get_offset(cx, &idx_left, canonical_id); + if let Some(offset_right) = get_offset(cx, &idx_right, canonical_id); + + // Source and destination must be different + if var_def_id(cx, seqexpr_left) != var_def_id(cx, seqexpr_right); + then { + Some((FixedOffsetVar { var: seqexpr_left, offset: offset_left }, + FixedOffsetVar { var: seqexpr_right, offset: offset_right })) + } else { + None + } + } + }) }) - .join("\n "); + .map(|o| o.map(|(dst, src)| build_manual_memcpy_suggestion(cx, start, end, limits, dst, src))) + .collect::<Option<Vec<_>>>() + .filter(|v| !v.is_empty()) + .map(|v| v.join("\n ")); - if !big_sugg.is_empty() { + if let Some(big_sugg) = big_sugg { span_lint_and_sugg( cx, MANUAL_MEMCPY, diff --git a/clippy_lints/src/manual_async_fn.rs b/clippy_lints/src/manual_async_fn.rs new file mode 100644 index 00000000000..cb72a240582 --- /dev/null +++ b/clippy_lints/src/manual_async_fn.rs @@ -0,0 +1,159 @@ +use crate::utils::paths::FUTURE_FROM_GENERATOR; +use crate::utils::{match_function_call, snippet_block, snippet_opt, span_lint_and_then}; +use if_chain::if_chain; +use rustc_errors::Applicability; +use rustc_hir::intravisit::FnKind; +use rustc_hir::{ + AsyncGeneratorKind, Block, Body, Expr, ExprKind, FnDecl, FnRetTy, GeneratorKind, GenericBound, HirId, IsAsync, + ItemKind, TraitRef, Ty, TyKind, TypeBindingKind, +}; +use rustc_lint::{LateContext, LateLintPass}; +use rustc_session::{declare_lint_pass, declare_tool_lint}; +use rustc_span::Span; + +declare_clippy_lint! { + /// **What it does:** It checks for manual implementations of `async` functions. + /// + /// **Why is this bad?** It's more idiomatic to use the dedicated syntax. + /// + /// **Known problems:** None. + /// + /// **Example:** + /// + /// ```rust + /// use std::future::Future; + /// + /// fn foo() -> impl Future<Output = i32> { async { 42 } } + /// ``` + /// Use instead: + /// ```rust + /// use std::future::Future; + /// + /// async fn foo() -> i32 { 42 } + /// ``` + pub MANUAL_ASYNC_FN, + style, + "manual implementations of `async` functions can be simplified using the dedicated syntax" +} + +declare_lint_pass!(ManualAsyncFn => [MANUAL_ASYNC_FN]); + +impl<'a, 'tcx> LateLintPass<'a, 'tcx> for ManualAsyncFn { + fn check_fn( + &mut self, + cx: &LateContext<'a, 'tcx>, + kind: FnKind<'tcx>, + decl: &'tcx FnDecl<'_>, + body: &'tcx Body<'_>, + span: Span, + _: HirId, + ) { + if_chain! { + if let Some(header) = kind.header(); + if let IsAsync::NotAsync = header.asyncness; + // Check that this function returns `impl Future` + if let FnRetTy::Return(ret_ty) = decl.output; + if let Some(trait_ref) = future_trait_ref(cx, ret_ty); + if let Some(output) = future_output_ty(trait_ref); + // Check that the body of the function consists of one async block + if let ExprKind::Block(block, _) = body.value.kind; + if block.stmts.is_empty(); + if let Some(closure_body) = desugared_async_block(cx, block); + then { + let header_span = span.with_hi(ret_ty.span.hi()); + + span_lint_and_then( + cx, + MANUAL_ASYNC_FN, + header_span, + "this function can be simplified using the `async fn` syntax", + |diag| { + if_chain! { + if let Some(header_snip) = snippet_opt(cx, header_span); + if let Some(ret_pos) = header_snip.rfind("->"); + if let Some((ret_sugg, ret_snip)) = suggested_ret(cx, output); + then { + let help = format!("make the function `async` and {}", ret_sugg); + diag.span_suggestion( + header_span, + &help, + format!("async {}{}", &header_snip[..ret_pos], ret_snip), + Applicability::MachineApplicable + ); + + let body_snip = snippet_block(cx, closure_body.value.span, "..", Some(block.span)); + diag.span_suggestion( + block.span, + "move the body of the async block to the enclosing function", + body_snip.to_string(), + Applicability::MachineApplicable + ); + } + } + }, + ); + } + } + } +} + +fn future_trait_ref<'tcx>(cx: &LateContext<'_, 'tcx>, ty: &'tcx Ty<'tcx>) -> Option<&'tcx TraitRef<'tcx>> { + if_chain! { + if let TyKind::Def(item_id, _) = ty.kind; + let item = cx.tcx.hir().item(item_id.id); + if let ItemKind::OpaqueTy(opaque) = &item.kind; + if opaque.bounds.len() == 1; + if let GenericBound::Trait(poly, _) = &opaque.bounds[0]; + if poly.trait_ref.trait_def_id() == cx.tcx.lang_items().future_trait(); + then { + return Some(&poly.trait_ref); + } + } + + None +} + +fn future_output_ty<'tcx>(trait_ref: &'tcx TraitRef<'tcx>) -> Option<&'tcx Ty<'tcx>> { + if_chain! { + if let Some(segment) = trait_ref.path.segments.last(); + if let Some(args) = segment.args; + if args.bindings.len() == 1; + let binding = &args.bindings[0]; + if binding.ident.as_str() == "Output"; + if let TypeBindingKind::Equality{ty: output} = binding.kind; + then { + return Some(output) + } + } + + None +} + +fn desugared_async_block<'tcx>(cx: &LateContext<'_, 'tcx>, block: &'tcx Block<'tcx>) -> Option<&'tcx Body<'tcx>> { + if_chain! { + if let Some(block_expr) = block.expr; + if let Some(args) = match_function_call(cx, block_expr, &FUTURE_FROM_GENERATOR); + if args.len() == 1; + if let Expr{kind: ExprKind::Closure(_, _, body_id, ..), ..} = args[0]; + let closure_body = cx.tcx.hir().body(body_id); + if let Some(GeneratorKind::Async(AsyncGeneratorKind::Block)) = closure_body.generator_kind; + then { + return Some(closure_body); + } + } + + None +} + +fn suggested_ret(cx: &LateContext<'_, '_>, output: &Ty<'_>) -> Option<(&'static str, String)> { + match output.kind { + TyKind::Tup(tys) if tys.is_empty() => { + let sugg = "remove the return type"; + Some((sugg, "".into())) + }, + _ => { + let sugg = "return the output of the future directly"; + snippet_opt(cx, output.span).map(|snip| (sugg, format!("-> {}", snip))) + }, + } +} diff --git a/clippy_lints/src/manual_non_exhaustive.rs b/clippy_lints/src/manual_non_exhaustive.rs new file mode 100644 index 00000000000..f3b8902e26f --- /dev/null +++ b/clippy_lints/src/manual_non_exhaustive.rs @@ -0,0 +1,173 @@ +use crate::utils::{snippet_opt, span_lint_and_then}; +use if_chain::if_chain; +use rustc_ast::ast::{Attribute, Item, ItemKind, StructField, Variant, VariantData, VisibilityKind}; +use rustc_attr as attr; +use rustc_errors::Applicability; +use rustc_lint::{EarlyContext, EarlyLintPass}; +use rustc_session::{declare_lint_pass, declare_tool_lint}; +use rustc_span::Span; + +declare_clippy_lint! { + /// **What it does:** Checks for manual implementations of the non-exhaustive pattern. + /// + /// **Why is this bad?** Using the #[non_exhaustive] attribute expresses better the intent + /// and allows possible optimizations when applied to enums. + /// + /// **Known problems:** None. + /// + /// **Example:** + /// + /// ```rust + /// struct S { + /// pub a: i32, + /// pub b: i32, + /// _c: (), + /// } + /// + /// enum E { + /// A, + /// B, + /// #[doc(hidden)] + /// _C, + /// } + /// + /// struct T(pub i32, pub i32, ()); + /// ``` + /// Use instead: + /// ```rust + /// #[non_exhaustive] + /// struct S { + /// pub a: i32, + /// pub b: i32, + /// } + /// + /// #[non_exhaustive] + /// enum E { + /// A, + /// B, + /// } + /// + /// #[non_exhaustive] + /// struct T(pub i32, pub i32); + /// ``` + pub MANUAL_NON_EXHAUSTIVE, + style, + "manual implementations of the non-exhaustive pattern can be simplified using #[non_exhaustive]" +} + +declare_lint_pass!(ManualNonExhaustive => [MANUAL_NON_EXHAUSTIVE]); + +impl EarlyLintPass for ManualNonExhaustive { + fn check_item(&mut self, cx: &EarlyContext<'_>, item: &Item) { + match &item.kind { + ItemKind::Enum(def, _) => { + check_manual_non_exhaustive_enum(cx, item, &def.variants); + }, + ItemKind::Struct(variant_data, _) => { + if let VariantData::Unit(..) = variant_data { + return; + } + + check_manual_non_exhaustive_struct(cx, item, variant_data); + }, + _ => {}, + } + } +} + +fn check_manual_non_exhaustive_enum(cx: &EarlyContext<'_>, item: &Item, variants: &[Variant]) { + fn is_non_exhaustive_marker(variant: &Variant) -> bool { + matches!(variant.data, VariantData::Unit(_)) + && variant.ident.as_str().starts_with('_') + && variant.attrs.iter().any(|a| is_doc_hidden(a)) + } + + fn is_doc_hidden(attr: &Attribute) -> bool { + attr.check_name(sym!(doc)) + && match attr.meta_item_list() { + Some(l) => attr::list_contains_name(&l, sym!(hidden)), + None => false, + } + } + + if_chain! { + let mut markers = variants.iter().filter(|v| is_non_exhaustive_marker(v)); + if let Some(marker) = markers.next(); + if markers.count() == 0 && variants.len() > 1; + then { + span_lint_and_then( + cx, + MANUAL_NON_EXHAUSTIVE, + item.span, + "this seems like a manual implementation of the non-exhaustive pattern", + |diag| { + if_chain! { + if !attr::contains_name(&item.attrs, sym!(non_exhaustive)); + let header_span = cx.sess.source_map().span_until_char(item.span, '{'); + if let Some(snippet) = snippet_opt(cx, header_span); + then { + diag.span_suggestion( + header_span, + "add the attribute", + format!("#[non_exhaustive] {}", snippet), + Applicability::Unspecified, + ); + } + } + diag.span_help(marker.span, "remove this variant"); + }); + } + } +} + +fn check_manual_non_exhaustive_struct(cx: &EarlyContext<'_>, item: &Item, data: &VariantData) { + fn is_private(field: &StructField) -> bool { + matches!(field.vis.node, VisibilityKind::Inherited) + } + + fn is_non_exhaustive_marker(field: &StructField) -> bool { + is_private(field) && field.ty.kind.is_unit() && field.ident.map_or(true, |n| n.as_str().starts_with('_')) + } + + fn find_header_span(cx: &EarlyContext<'_>, item: &Item, data: &VariantData) -> Span { + let delimiter = match data { + VariantData::Struct(..) => '{', + VariantData::Tuple(..) => '(', + VariantData::Unit(_) => unreachable!("`VariantData::Unit` is already handled above"), + }; + + cx.sess.source_map().span_until_char(item.span, delimiter) + } + + let fields = data.fields(); + let private_fields = fields.iter().filter(|f| is_private(f)).count(); + let public_fields = fields.iter().filter(|f| f.vis.node.is_pub()).count(); + + if_chain! { + if private_fields == 1 && public_fields >= 1 && public_fields == fields.len() - 1; + if let Some(marker) = fields.iter().find(|f| is_non_exhaustive_marker(f)); + then { + span_lint_and_then( + cx, + MANUAL_NON_EXHAUSTIVE, + item.span, + "this seems like a manual implementation of the non-exhaustive pattern", + |diag| { + if_chain! { + if !attr::contains_name(&item.attrs, sym!(non_exhaustive)); + let header_span = find_header_span(cx, item, data); + if let Some(snippet) = snippet_opt(cx, header_span); + then { + diag.span_suggestion( + header_span, + "add the attribute", + format!("#[non_exhaustive] {}", snippet), + Applicability::Unspecified, + ); + } + } + diag.span_help(marker.span, "remove this field"); + }); + } + } +} diff --git a/clippy_lints/src/match_on_vec_items.rs b/clippy_lints/src/match_on_vec_items.rs index 4071406cc84..ee69628e9f0 100644 --- a/clippy_lints/src/match_on_vec_items.rs +++ b/clippy_lints/src/match_on_vec_items.rs @@ -1,4 +1,4 @@ -use crate::utils::{is_type_diagnostic_item, snippet, span_lint_and_sugg, walk_ptrs_ty}; +use crate::utils::{self, is_type_diagnostic_item, match_type, snippet, span_lint_and_sugg, walk_ptrs_ty}; use if_chain::if_chain; use rustc_errors::Applicability; use rustc_hir::{Expr, ExprKind, MatchSource}; @@ -38,7 +38,7 @@ declare_clippy_lint! { /// } /// ``` pub MATCH_ON_VEC_ITEMS, - correctness, + pedantic, "matching on vector elements can panic" } @@ -75,10 +75,9 @@ impl<'a, 'tcx> LateLintPass<'a, 'tcx> for MatchOnVecItems { fn is_vec_indexing<'a, 'tcx>(cx: &LateContext<'a, 'tcx>, expr: &'tcx Expr<'tcx>) -> Option<&'tcx Expr<'tcx>> { if_chain! { - if let ExprKind::Index(ref array, _) = expr.kind; - let ty = cx.tables.expr_ty(array); - let ty = walk_ptrs_ty(ty); - if is_type_diagnostic_item(cx, ty, sym!(vec_type)); + if let ExprKind::Index(ref array, ref index) = expr.kind; + if is_vector(cx, array); + if !is_full_range(cx, index); then { return Some(expr); @@ -87,3 +86,15 @@ fn is_vec_indexing<'a, 'tcx>(cx: &LateContext<'a, 'tcx>, expr: &'tcx Expr<'tcx>) None } + +fn is_vector(cx: &LateContext<'_, '_>, expr: &Expr<'_>) -> bool { + let ty = cx.tables.expr_ty(expr); + let ty = walk_ptrs_ty(ty); + is_type_diagnostic_item(cx, ty, sym!(vec_type)) +} + +fn is_full_range(cx: &LateContext<'_, '_>, expr: &Expr<'_>) -> bool { + let ty = cx.tables.expr_ty(expr); + let ty = walk_ptrs_ty(ty); + match_type(cx, ty, &utils::paths::RANGE_FULL) +} diff --git a/clippy_lints/src/misc_early.rs b/clippy_lints/src/misc_early.rs index adfd8dfb1c1..62ee051624b 100644 --- a/clippy_lints/src/misc_early.rs +++ b/clippy_lints/src/misc_early.rs @@ -24,8 +24,25 @@ declare_clippy_lint! { /// **Known problems:** None. /// /// **Example:** - /// ```ignore - /// let { a: _, b: ref b, c: _ } = .. + /// ```rust + /// # struct Foo { + /// # a: i32, + /// # b: i32, + /// # c: i32, + /// # } + /// let f = Foo { a: 0, b: 0, c: 0 }; + /// + /// // Bad + /// match f { + /// Foo { a: _, b: 0, .. } => {}, + /// Foo { a: _, b: _, c: _ } => {}, + /// } + /// + /// // Good + /// match f { + /// Foo { b: 0, .. } => {}, + /// Foo { .. } => {}, + /// } /// ``` pub UNNEEDED_FIELD_PATTERN, restriction, diff --git a/clippy_lints/src/unwrap.rs b/clippy_lints/src/unwrap.rs index 5235c98efab..f3844c7d3b6 100644 --- a/clippy_lints/src/unwrap.rs +++ b/clippy_lints/src/unwrap.rs @@ -1,4 +1,7 @@ -use crate::utils::{higher::if_block, is_type_diagnostic_item, span_lint_and_then, usage::is_potentially_mutated}; +use crate::utils::{ + differing_macro_contexts, higher::if_block, 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}; use rustc_hir::{BinOpKind, Body, Expr, ExprKind, FnDecl, HirId, Path, QPath, UnOp}; @@ -73,6 +76,8 @@ struct UnwrapInfo<'tcx> { ident: &'tcx Path<'tcx>, /// The check, like `x.is_ok()` check: &'tcx Expr<'tcx>, + /// The branch where the check takes place, like `if x.is_ok() { .. }` + branch: &'tcx Expr<'tcx>, /// Whether `is_some()` or `is_ok()` was called (as opposed to `is_err()` or `is_none()`). safe_to_unwrap: bool, } @@ -82,19 +87,20 @@ struct UnwrapInfo<'tcx> { fn collect_unwrap_info<'a, 'tcx>( cx: &'a LateContext<'a, 'tcx>, expr: &'tcx Expr<'_>, + branch: &'tcx Expr<'_>, invert: bool, ) -> Vec<UnwrapInfo<'tcx>> { if let ExprKind::Binary(op, left, right) = &expr.kind { match (invert, op.node) { (false, BinOpKind::And) | (false, BinOpKind::BitAnd) | (true, BinOpKind::Or) | (true, BinOpKind::BitOr) => { - let mut unwrap_info = collect_unwrap_info(cx, left, invert); - unwrap_info.append(&mut collect_unwrap_info(cx, right, invert)); + let mut unwrap_info = collect_unwrap_info(cx, left, branch, invert); + unwrap_info.append(&mut collect_unwrap_info(cx, right, branch, invert)); return unwrap_info; }, _ => (), } } else if let ExprKind::Unary(UnOp::UnNot, expr) = &expr.kind { - return collect_unwrap_info(cx, expr, !invert); + return collect_unwrap_info(cx, expr, branch, !invert); } else { if_chain! { if let ExprKind::MethodCall(method_name, _, args) = &expr.kind; @@ -111,7 +117,7 @@ fn collect_unwrap_info<'a, 'tcx>( _ => unreachable!(), }; let safe_to_unwrap = unwrappable != invert; - return vec![UnwrapInfo { ident: path, check: expr, safe_to_unwrap }]; + return vec![UnwrapInfo { ident: path, check: expr, branch, safe_to_unwrap }]; } } } @@ -121,7 +127,7 @@ fn collect_unwrap_info<'a, 'tcx>( impl<'a, 'tcx> UnwrappableVariablesVisitor<'a, 'tcx> { fn visit_branch(&mut self, cond: &'tcx Expr<'_>, branch: &'tcx Expr<'_>, else_branch: bool) { let prev_len = self.unwrappables.len(); - for unwrap_info in collect_unwrap_info(self.cx, cond, else_branch) { + for unwrap_info in collect_unwrap_info(self.cx, cond, branch, else_branch) { if is_potentially_mutated(unwrap_info.ident, cond, self.cx) || is_potentially_mutated(unwrap_info.ident, branch, self.cx) { @@ -158,6 +164,9 @@ impl<'a, 'tcx> Visitor<'tcx> for UnwrappableVariablesVisitor<'a, 'tcx> { let call_to_unwrap = method_name.ident.name == sym!(unwrap); if let Some(unwrappable) = self.unwrappables.iter() .find(|u| u.ident.res == path.res); + // Span contexts should not differ with the conditional branch + if !differing_macro_contexts(unwrappable.branch.span, expr.span); + if !differing_macro_contexts(unwrappable.branch.span, unwrappable.check.span); then { if call_to_unwrap == unwrappable.safe_to_unwrap { span_lint_and_then( diff --git a/clippy_lints/src/utils/conf.rs b/clippy_lints/src/utils/conf.rs index 4b81ff33495..57b9eafd14d 100644 --- a/clippy_lints/src/utils/conf.rs +++ b/clippy_lints/src/utils/conf.rs @@ -158,6 +158,8 @@ define_Conf! { (max_struct_bools, "max_struct_bools": u64, 3), /// Lint: FN_PARAMS_EXCESSIVE_BOOLS. The maximum number of bools function parameters can have (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), } impl Default for Conf { diff --git a/clippy_lints/src/utils/mod.rs b/clippy_lints/src/utils/mod.rs index 2fd080e9ef0..3b8ef18bfab 100644 --- a/clippy_lints/src/utils/mod.rs +++ b/clippy_lints/src/utils/mod.rs @@ -933,6 +933,7 @@ pub fn is_ctor_or_promotable_const_function(cx: &LateContext<'_, '_>, expr: &Exp } /// Returns `true` if a pattern is refutable. +// TODO: should be implemented using rustc/mir_build/hair machinery pub fn is_refutable(cx: &LateContext<'_, '_>, pat: &Pat<'_>) -> bool { fn is_enum_variant(cx: &LateContext<'_, '_>, qpath: &QPath<'_>, id: HirId) -> bool { matches!( @@ -946,27 +947,34 @@ pub fn is_refutable(cx: &LateContext<'_, '_>, pat: &Pat<'_>) -> bool { } match pat.kind { - PatKind::Binding(..) | PatKind::Wild => false, + PatKind::Wild => false, + PatKind::Binding(_, _, _, pat) => pat.map_or(false, |pat| is_refutable(cx, pat)), PatKind::Box(ref pat) | PatKind::Ref(ref pat, _) => is_refutable(cx, pat), PatKind::Lit(..) | PatKind::Range(..) => true, PatKind::Path(ref qpath) => is_enum_variant(cx, qpath, pat.hir_id), - PatKind::Or(ref pats) | PatKind::Tuple(ref pats, _) => are_refutable(cx, pats.iter().map(|pat| &**pat)), + PatKind::Or(ref pats) => { + // TODO: should be the honest check, that pats is exhaustive set + are_refutable(cx, pats.iter().map(|pat| &**pat)) + }, + PatKind::Tuple(ref pats, _) => are_refutable(cx, pats.iter().map(|pat| &**pat)), PatKind::Struct(ref qpath, ref fields, _) => { - if is_enum_variant(cx, qpath, pat.hir_id) { - true - } else { - are_refutable(cx, fields.iter().map(|field| &*field.pat)) - } + is_enum_variant(cx, qpath, pat.hir_id) || are_refutable(cx, fields.iter().map(|field| &*field.pat)) }, PatKind::TupleStruct(ref qpath, ref pats, _) => { - if is_enum_variant(cx, qpath, pat.hir_id) { - true - } else { - are_refutable(cx, pats.iter().map(|pat| &**pat)) - } + is_enum_variant(cx, qpath, pat.hir_id) || are_refutable(cx, pats.iter().map(|pat| &**pat)) }, PatKind::Slice(ref head, ref middle, ref tail) => { - are_refutable(cx, head.iter().chain(middle).chain(tail.iter()).map(|pat| &**pat)) + match &cx.tables.node_type(pat.hir_id).kind { + ty::Slice(..) => { + // [..] is the only irrefutable slice pattern. + !head.is_empty() || middle.is_none() || !tail.is_empty() + }, + ty::Array(..) => are_refutable(cx, head.iter().chain(middle).chain(tail.iter()).map(|pat| &**pat)), + _ => { + // unreachable!() + true + }, + } }, } } diff --git a/clippy_lints/src/utils/paths.rs b/clippy_lints/src/utils/paths.rs index ca2c4ade155..b3ad2ad9d99 100644 --- a/clippy_lints/src/utils/paths.rs +++ b/clippy_lints/src/utils/paths.rs @@ -42,6 +42,7 @@ pub const FMT_ARGUMENTS_NEW_V1_FORMATTED: [&str; 4] = ["core", "fmt", "Arguments pub const FMT_ARGUMENTV1_NEW: [&str; 4] = ["core", "fmt", "ArgumentV1", "new"]; pub const FROM_FROM: [&str; 4] = ["core", "convert", "From", "from"]; pub const FROM_TRAIT: [&str; 3] = ["core", "convert", "From"]; +pub const FUTURE_FROM_GENERATOR: [&str; 3] = ["core", "future", "from_generator"]; pub const HASH: [&str; 2] = ["hash", "Hash"]; pub const HASHMAP: [&str; 5] = ["std", "collections", "hash", "map", "HashMap"]; pub const HASHMAP_ENTRY: [&str; 5] = ["std", "collections", "hash", "map", "Entry"]; @@ -85,7 +86,7 @@ pub const RANGE: [&str; 3] = ["core", "ops", "Range"]; pub const RANGE_ARGUMENT_TRAIT: [&str; 3] = ["core", "ops", "RangeBounds"]; pub const RANGE_FROM: [&str; 3] = ["core", "ops", "RangeFrom"]; pub const RANGE_FROM_STD: [&str; 3] = ["std", "ops", "RangeFrom"]; -pub const RANGE_FULL: [&str; 3] = ["core", "ops", "RangeFull"]; +pub const RANGE_FULL: [&str; 4] = ["core", "ops", "range", "RangeFull"]; pub const RANGE_FULL_STD: [&str; 3] = ["std", "ops", "RangeFull"]; pub const RANGE_INCLUSIVE_NEW: [&str; 4] = ["core", "ops", "RangeInclusive", "new"]; pub const RANGE_INCLUSIVE_STD_NEW: [&str; 4] = ["std", "ops", "RangeInclusive", "new"]; diff --git a/clippy_lints/src/wildcard_imports.rs b/clippy_lints/src/wildcard_imports.rs index f3038861cee..32d9a45c37d 100644 --- a/clippy_lints/src/wildcard_imports.rs +++ b/clippy_lints/src/wildcard_imports.rs @@ -3,10 +3,10 @@ use if_chain::if_chain; use rustc_errors::Applicability; use rustc_hir::{ def::{DefKind, Res}, - Item, ItemKind, UseKind, + Item, ItemKind, PathSegment, UseKind, }; 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::BytePos; declare_clippy_lint! { @@ -43,9 +43,14 @@ declare_clippy_lint! { /// /// This can lead to confusing error messages at best and to unexpected behavior at worst. /// - /// Note that this will not warn about wildcard imports from modules named `prelude`; many - /// crates (including the standard library) provide modules named "prelude" specifically - /// designed for wildcard import. + /// **Exceptions:** + /// + /// Wildcard imports are allowed from modules named `prelude`. Many crates (including the standard library) + /// provide modules named "prelude" specifically designed for wildcard import. + /// + /// `use super::*` is allowed in test modules. This is defined as any module with "test" in the name. + /// + /// These exceptions can be disabled using the `warn-on-all-wildcard-imports` configuration flag. /// /// **Known problems:** If macros are imported through the wildcard, this macro is not included /// by the suggestion and has to be added by hand. @@ -73,18 +78,34 @@ declare_clippy_lint! { "lint `use _::*` statements" } -declare_lint_pass!(WildcardImports => [ENUM_GLOB_USE, WILDCARD_IMPORTS]); +#[derive(Default)] +pub struct WildcardImports { + warn_on_all: bool, + test_modules_deep: u32, +} + +impl WildcardImports { + pub fn new(warn_on_all: bool) -> Self { + Self { + warn_on_all, + test_modules_deep: 0, + } + } +} + +impl_lint_pass!(WildcardImports => [ENUM_GLOB_USE, WILDCARD_IMPORTS]); impl LateLintPass<'_, '_> for WildcardImports { fn check_item(&mut self, cx: &LateContext<'_, '_>, item: &Item<'_>) { + if is_test_module_or_function(item) { + self.test_modules_deep = self.test_modules_deep.saturating_add(1); + } if item.vis.node.is_pub() || item.vis.node.is_pub_restricted() { return; } if_chain! { - if !in_macro(item.span); if let ItemKind::Use(use_path, UseKind::Glob) = &item.kind; - // don't lint prelude glob imports - if !use_path.segments.iter().last().map_or(false, |ps| ps.ident.as_str() == "prelude"); + if self.warn_on_all || !self.check_exceptions(item, use_path.segments); let used_imports = cx.tcx.names_imported_by_glob_use(item.hir_id.owner); if !used_imports.is_empty(); // Already handled by `unused_imports` then { @@ -109,8 +130,7 @@ impl LateLintPass<'_, '_> for WildcardImports { span = use_path.span.with_hi(item.span.hi() - BytePos(1)); } ( - span, - false, + span, false, ) }; @@ -153,4 +173,36 @@ impl LateLintPass<'_, '_> for WildcardImports { } } } + + fn check_item_post(&mut self, _: &LateContext<'_, '_>, item: &Item<'_>) { + if is_test_module_or_function(item) { + self.test_modules_deep = self.test_modules_deep.saturating_sub(1); + } + } +} + +impl WildcardImports { + fn check_exceptions(&self, item: &Item<'_>, segments: &[PathSegment<'_>]) -> bool { + in_macro(item.span) + || is_prelude_import(segments) + || (is_super_only_import(segments) && self.test_modules_deep > 0) + } +} + +// 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() + .last() + .map_or(false, |ps| ps.ident.as_str() == "prelude") +} + +// Allow "super::*" imports in tests. +fn is_super_only_import(segments: &[PathSegment<'_>]) -> bool { + segments.len() == 1 && segments[0].ident.as_str() == "super" +} + +fn is_test_module_or_function(item: &Item<'_>) -> bool { + matches!(item.kind, ItemKind::Mod(..)) && item.ident.name.as_str().contains("test") } |