#![feature(box_patterns)] #![feature(in_band_lifetimes)] #![feature(iter_zip)] #![feature(rustc_private)] #![recursion_limit = "512"] #![cfg_attr(feature = "deny-warnings", deny(warnings))] #![allow(clippy::missing_errors_doc, clippy::missing_panics_doc, clippy::must_use_candidate)] // warn on the same lints as `clippy_lints` #![warn(trivial_casts, trivial_numeric_casts)] // warn on lints, that are included in `rust-lang/rust`s bootstrap #![warn(rust_2018_idioms, unused_lifetimes)] // warn on rustc internal lints #![warn(rustc::internal)] // FIXME: switch to something more ergonomic here, once available. // (Currently there is no way to opt into sysroot crates without `extern crate`.) extern crate rustc_ast; extern crate rustc_ast_pretty; extern crate rustc_attr; extern crate rustc_data_structures; extern crate rustc_errors; extern crate rustc_hir; extern crate rustc_infer; extern crate rustc_lexer; extern crate rustc_lint; extern crate rustc_middle; extern crate rustc_mir; extern crate rustc_session; extern crate rustc_span; extern crate rustc_target; extern crate rustc_trait_selection; extern crate rustc_typeck; #[macro_use] pub mod sym_helper; #[allow(clippy::module_name_repetitions)] pub mod ast_utils; pub mod attrs; pub mod camel_case; pub mod comparisons; pub mod consts; pub mod diagnostics; pub mod eager_or_lazy; pub mod higher; mod hir_utils; pub mod msrvs; pub mod numeric_literal; pub mod paths; pub mod ptr; pub mod qualify_min_const_fn; pub mod source; pub mod sugg; pub mod ty; pub mod usage; pub mod visitors; pub use self::attrs::*; pub use self::hir_utils::{both, count_eq, eq_expr_value, over, SpanlessEq, SpanlessHash}; use std::collections::hash_map::Entry; use std::hash::BuildHasherDefault; use if_chain::if_chain; use rustc_ast::ast::{self, Attribute, BorrowKind, LitKind}; use rustc_data_structures::unhash::UnhashMap; use rustc_hir as hir; use rustc_hir::def::{DefKind, Res}; use rustc_hir::def_id::DefId; use rustc_hir::intravisit::{self, walk_expr, ErasedMap, FnKind, NestedVisitorMap, Visitor}; use rustc_hir::LangItem::{ResultErr, ResultOk}; use rustc_hir::{ def, Arm, BindingAnnotation, Block, Body, Constness, Destination, Expr, ExprKind, FnDecl, GenericArgs, HirId, Impl, ImplItem, ImplItemKind, IsAsync, Item, ItemKind, LangItem, Local, MatchSource, Node, Param, Pat, PatKind, Path, PathSegment, QPath, Stmt, StmtKind, TraitItem, TraitItemKind, TraitRef, TyKind, UnOp, }; use rustc_lint::{LateContext, Level, Lint, LintContext}; use rustc_middle::hir::exports::Export; use rustc_middle::hir::map::Map; use rustc_middle::ty as rustc_ty; use rustc_middle::ty::{layout::IntegerExt, DefIdTree, Ty, TyCtxt, TypeFoldable}; use rustc_semver::RustcVersion; use rustc_session::Session; use rustc_span::hygiene::{ExpnKind, MacroKind}; use rustc_span::source_map::original_sp; use rustc_span::sym; use rustc_span::symbol::{kw, Symbol}; use rustc_span::{Span, DUMMY_SP}; use rustc_target::abi::Integer; use crate::consts::{constant, Constant}; use crate::ty::{can_partially_move_ty, is_recursively_primitive_type}; pub fn parse_msrv(msrv: &str, sess: Option<&Session>, span: Option) -> Option { if let Ok(version) = RustcVersion::parse(msrv) { return Some(version); } else if let Some(sess) = sess { if let Some(span) = span { sess.span_err(span, &format!("`{}` is not a valid Rust version", msrv)); } } None } pub fn meets_msrv(msrv: Option<&RustcVersion>, lint_msrv: &RustcVersion) -> bool { msrv.map_or(true, |msrv| msrv.meets(*lint_msrv)) } #[macro_export] macro_rules! extract_msrv_attr { (LateContext) => { extract_msrv_attr!(@LateContext, ()); }; (EarlyContext) => { extract_msrv_attr!(@EarlyContext); }; (@$context:ident$(, $call:tt)?) => { fn enter_lint_attrs(&mut self, cx: &rustc_lint::$context<'tcx>, attrs: &'tcx [rustc_ast::ast::Attribute]) { use $crate::get_unique_inner_attr; match get_unique_inner_attr(cx.sess$($call)?, attrs, "msrv") { Some(msrv_attr) => { if let Some(msrv) = msrv_attr.value_str() { self.msrv = $crate::parse_msrv( &msrv.to_string(), Some(cx.sess$($call)?), Some(msrv_attr.span), ); } else { cx.sess$($call)?.span_err(msrv_attr.span, "bad clippy attribute"); } }, _ => (), } } }; } /// Returns `true` if the two spans come from differing expansions (i.e., one is /// from a macro and one isn't). #[must_use] pub fn differing_macro_contexts(lhs: Span, rhs: Span) -> bool { rhs.ctxt() != lhs.ctxt() } /// If the given expression is a local binding, find the initializer expression. /// If that initializer expression is another local binding, find its initializer again. /// This process repeats as long as possible (but usually no more than once). Initializer /// expressions with adjustments are ignored. If this is not desired, use [`find_binding_init`] /// instead. /// /// Examples: /// ```ignore /// let abc = 1; /// // ^ output /// let def = abc; /// dbg!(def) /// // ^^^ input /// /// // or... /// let abc = 1; /// let def = abc + 2; /// // ^^^^^^^ output /// dbg!(def) /// // ^^^ input /// ``` pub fn expr_or_init<'a, 'b, 'tcx: 'b>(cx: &LateContext<'tcx>, mut expr: &'a Expr<'b>) -> &'a Expr<'b> { while let Some(init) = path_to_local(expr) .and_then(|id| find_binding_init(cx, id)) .filter(|init| cx.typeck_results().expr_adjustments(init).is_empty()) { expr = init; } expr } /// Finds the initializer expression for a local binding. Returns `None` if the binding is mutable. /// By only considering immutable bindings, we guarantee that the returned expression represents the /// value of the binding wherever it is referenced. /// /// Example: For `let x = 1`, if the `HirId` of `x` is provided, the `Expr` `1` is returned. /// Note: If you have an expression that references a binding `x`, use `path_to_local` to get the /// canonical binding `HirId`. pub fn find_binding_init<'tcx>(cx: &LateContext<'tcx>, hir_id: HirId) -> Option<&'tcx Expr<'tcx>> { let hir = cx.tcx.hir(); if_chain! { if let Some(Node::Binding(pat)) = hir.find(hir_id); if matches!(pat.kind, PatKind::Binding(BindingAnnotation::Unannotated, ..)); let parent = hir.get_parent_node(hir_id); if let Some(Node::Local(local)) = hir.find(parent); then { return local.init; } } None } /// Returns `true` if the given `NodeId` is inside a constant context /// /// # Example /// /// ```rust,ignore /// if in_constant(cx, expr.hir_id) { /// // Do something /// } /// ``` pub fn in_constant(cx: &LateContext<'_>, id: HirId) -> bool { let parent_id = cx.tcx.hir().get_parent_item(id); match cx.tcx.hir().get(parent_id) { Node::Item(&Item { kind: ItemKind::Const(..) | ItemKind::Static(..), .. }) | Node::TraitItem(&TraitItem { kind: TraitItemKind::Const(..), .. }) | Node::ImplItem(&ImplItem { kind: ImplItemKind::Const(..), .. }) | Node::AnonConst(_) => true, Node::Item(&Item { kind: ItemKind::Fn(ref sig, ..), .. }) | Node::ImplItem(&ImplItem { kind: ImplItemKind::Fn(ref sig, _), .. }) => sig.header.constness == Constness::Const, _ => false, } } /// Checks if a `QPath` resolves to a constructor of a `LangItem`. /// For example, use this to check whether a function call or a pattern is `Some(..)`. pub fn is_lang_ctor(cx: &LateContext<'_>, qpath: &QPath<'_>, lang_item: LangItem) -> bool { if let QPath::Resolved(_, path) = qpath { if let Res::Def(DefKind::Ctor(..), ctor_id) = path.res { if let Ok(item_id) = cx.tcx.lang_items().require(lang_item) { return cx.tcx.parent(ctor_id) == Some(item_id); } } } false } /// Returns `true` if this `span` was expanded by any macro. #[must_use] pub fn in_macro(span: Span) -> bool { if span.from_expansion() { !matches!(span.ctxt().outer_expn_data().kind, ExpnKind::Desugaring(..)) } else { false } } /// Checks if given pattern is a wildcard (`_`) pub fn is_wild<'tcx>(pat: &impl std::ops::Deref>) -> bool { matches!(pat.kind, PatKind::Wild) } /// Checks if the first type parameter is a lang item. pub fn is_ty_param_lang_item(cx: &LateContext<'_>, qpath: &QPath<'tcx>, item: LangItem) -> Option<&'tcx hir::Ty<'tcx>> { let ty = get_qpath_generic_tys(qpath).next()?; if let TyKind::Path(qpath) = &ty.kind { cx.qpath_res(qpath, ty.hir_id) .opt_def_id() .map_or(false, |id| { cx.tcx.lang_items().require(item).map_or(false, |lang_id| id == lang_id) }) .then(|| ty) } else { None } } /// Checks if the first type parameter is a diagnostic item. pub fn is_ty_param_diagnostic_item( cx: &LateContext<'_>, qpath: &QPath<'tcx>, item: Symbol, ) -> Option<&'tcx hir::Ty<'tcx>> { let ty = get_qpath_generic_tys(qpath).next()?; if let TyKind::Path(qpath) = &ty.kind { cx.qpath_res(qpath, ty.hir_id) .opt_def_id() .map_or(false, |id| cx.tcx.is_diagnostic_item(item, id)) .then(|| ty) } else { None } } /// Checks if the method call given in `expr` belongs to the given trait. /// This is a deprecated function, consider using [`is_trait_method`]. pub fn match_trait_method(cx: &LateContext<'_>, expr: &Expr<'_>, path: &[&str]) -> bool { let def_id = cx.typeck_results().type_dependent_def_id(expr.hir_id).unwrap(); let trt_id = cx.tcx.trait_of_item(def_id); trt_id.map_or(false, |trt_id| match_def_path(cx, trt_id, path)) } /// Checks if a method is defined in an impl of a diagnostic item pub fn is_diag_item_method(cx: &LateContext<'_>, def_id: DefId, diag_item: Symbol) -> bool { if let Some(impl_did) = cx.tcx.impl_of_method(def_id) { if let Some(adt) = cx.tcx.type_of(impl_did).ty_adt_def() { return cx.tcx.is_diagnostic_item(diag_item, adt.did); } } false } /// Checks if a method is in a diagnostic item trait pub fn is_diag_trait_item(cx: &LateContext<'_>, def_id: DefId, diag_item: Symbol) -> bool { if let Some(trait_did) = cx.tcx.trait_of_item(def_id) { return cx.tcx.is_diagnostic_item(diag_item, trait_did); } false } /// Checks if the method call given in `expr` belongs to the given trait. pub fn is_trait_method(cx: &LateContext<'_>, expr: &Expr<'_>, diag_item: Symbol) -> bool { cx.typeck_results() .type_dependent_def_id(expr.hir_id) .map_or(false, |did| is_diag_trait_item(cx, did, diag_item)) } pub fn last_path_segment<'tcx>(path: &QPath<'tcx>) -> &'tcx PathSegment<'tcx> { match *path { QPath::Resolved(_, path) => path.segments.last().expect("A path must have at least one segment"), QPath::TypeRelative(_, seg) => seg, QPath::LangItem(..) => panic!("last_path_segment: lang item has no path segments"), } } pub fn get_qpath_generics(path: &QPath<'tcx>) -> Option<&'tcx GenericArgs<'tcx>> { match path { QPath::Resolved(_, p) => p.segments.last().and_then(|s| s.args), QPath::TypeRelative(_, s) => s.args, QPath::LangItem(..) => None, } } pub fn get_qpath_generic_tys(path: &QPath<'tcx>) -> impl Iterator> { get_qpath_generics(path) .map_or([].as_ref(), |a| a.args) .iter() .filter_map(|a| { if let hir::GenericArg::Type(ty) = a { Some(ty) } else { None } }) } pub fn single_segment_path<'tcx>(path: &QPath<'tcx>) -> Option<&'tcx PathSegment<'tcx>> { match *path { QPath::Resolved(_, path) => path.segments.get(0), QPath::TypeRelative(_, seg) => Some(seg), QPath::LangItem(..) => None, } } /// THIS METHOD IS DEPRECATED and will eventually be removed since it does not match against the /// entire path or resolved `DefId`. Prefer using `match_def_path`. Consider getting a `DefId` from /// `QPath::Resolved.1.res.opt_def_id()`. /// /// Matches a `QPath` against a slice of segment string literals. /// /// There is also `match_path` if you are dealing with a `rustc_hir::Path` instead of a /// `rustc_hir::QPath`. /// /// # Examples /// ```rust,ignore /// match_qpath(path, &["std", "rt", "begin_unwind"]) /// ``` pub fn match_qpath(path: &QPath<'_>, segments: &[&str]) -> bool { match *path { QPath::Resolved(_, path) => match_path(path, segments), QPath::TypeRelative(ty, segment) => match ty.kind { TyKind::Path(ref inner_path) => { if let [prefix @ .., end] = segments { if match_qpath(inner_path, prefix) { return segment.ident.name.as_str() == *end; } } false }, _ => false, }, QPath::LangItem(..) => false, } } /// If the expression is a path, resolve it. Otherwise, return `Res::Err`. pub fn expr_path_res(cx: &LateContext<'_>, expr: &Expr<'_>) -> Res { if let ExprKind::Path(p) = &expr.kind { cx.qpath_res(p, expr.hir_id) } else { Res::Err } } /// Resolves the path to a `DefId` and checks if it matches the given path. pub fn is_qpath_def_path(cx: &LateContext<'_>, path: &QPath<'_>, hir_id: HirId, segments: &[&str]) -> bool { cx.qpath_res(path, hir_id) .opt_def_id() .map_or(false, |id| match_def_path(cx, id, segments)) } /// If the expression is a path, resolves it to a `DefId` and checks if it matches the given path. pub fn is_expr_path_def_path(cx: &LateContext<'_>, expr: &Expr<'_>, segments: &[&str]) -> bool { expr_path_res(cx, expr) .opt_def_id() .map_or(false, |id| match_def_path(cx, id, segments)) } /// THIS METHOD IS DEPRECATED and will eventually be removed since it does not match against the /// entire path or resolved `DefId`. Prefer using `match_def_path`. Consider getting a `DefId` from /// `QPath::Resolved.1.res.opt_def_id()`. /// /// Matches a `Path` against a slice of segment string literals. /// /// There is also `match_qpath` if you are dealing with a `rustc_hir::QPath` instead of a /// `rustc_hir::Path`. /// /// # Examples /// /// ```rust,ignore /// if match_path(&trait_ref.path, &paths::HASH) { /// // This is the `std::hash::Hash` trait. /// } /// /// if match_path(ty_path, &["rustc", "lint", "Lint"]) { /// // This is a `rustc_middle::lint::Lint`. /// } /// ``` pub fn match_path(path: &Path<'_>, segments: &[&str]) -> bool { path.segments .iter() .rev() .zip(segments.iter().rev()) .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 { if let ExprKind::Path(QPath::Resolved(None, 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 { macro_rules! try_res { ($e:expr) => { match $e { Some(e) => e, None => return Res::Err, } }; } fn item_child_by_name<'tcx>(tcx: TyCtxt<'tcx>, def_id: DefId, name: &str) -> Option<&'tcx Export> { tcx.item_children(def_id) .iter() .find(|item| item.ident.name.as_str() == name) } let (krate, first, path) = match *path { [krate, first, ref path @ ..] => (krate, first, path), _ => return Res::Err, }; let tcx = cx.tcx; let crates = tcx.crates(()); let krate = try_res!(crates.iter().find(|&&num| tcx.crate_name(num).as_str() == krate)); let first = try_res!(item_child_by_name(tcx, krate.as_def_id(), first)); let last = path .iter() .copied() // `get_def_path` seems to generate these empty segments for extern blocks. // We can just ignore them. .filter(|segment| !segment.is_empty()) // for each segment, find the child item .try_fold(first, |item, segment| { let def_id = item.res.def_id(); if let Some(item) = item_child_by_name(tcx, def_id, segment) { Some(item) } else if matches!(item.res, Res::Def(DefKind::Enum | DefKind::Struct, _)) { // it is not a child item so check inherent impl items tcx.inherent_impls(def_id) .iter() .find_map(|&impl_def_id| item_child_by_name(tcx, impl_def_id, segment)) } else { None } }); try_res!(last).res } /// Convenience function to get the `DefId` of a trait by path. /// It could be a trait or trait alias. pub fn get_trait_def_id(cx: &LateContext<'_>, path: &[&str]) -> Option { match path_to_res(cx, path) { Res::Def(DefKind::Trait | DefKind::TraitAlias, trait_id) => Some(trait_id), _ => None, } } /// Gets the `hir::TraitRef` of the trait the given method is implemented for. /// /// Use this if you want to find the `TraitRef` of the `Add` trait in this example: /// /// ```rust /// struct Point(isize, isize); /// /// impl std::ops::Add for Point { /// type Output = Self; /// /// fn add(self, other: Self) -> Self { /// Point(0, 0) /// } /// } /// ``` pub fn trait_ref_of_method<'tcx>(cx: &LateContext<'tcx>, hir_id: HirId) -> Option<&'tcx TraitRef<'tcx>> { // Get the implemented trait for the current function let parent_impl = cx.tcx.hir().get_parent_item(hir_id); if_chain! { if parent_impl != hir::CRATE_HIR_ID; if let hir::Node::Item(item) = cx.tcx.hir().get(parent_impl); if let hir::ItemKind::Impl(impl_) = &item.kind; then { return impl_.of_trait.as_ref(); } } None } /// Checks if the top level expression can be moved into a closure as is. pub fn can_move_expr_to_closure_no_visit(cx: &LateContext<'tcx>, expr: &'tcx Expr<'_>, jump_targets: &[HirId]) -> bool { match expr.kind { ExprKind::Break(Destination { target_id: Ok(id), .. }, _) | ExprKind::Continue(Destination { target_id: Ok(id), .. }) if jump_targets.contains(&id) => { true }, ExprKind::Break(..) | ExprKind::Continue(_) | ExprKind::Ret(_) | ExprKind::Yield(..) | ExprKind::InlineAsm(_) | ExprKind::LlvmInlineAsm(_) => false, // Accessing a field of a local value can only be done if the type isn't // partially moved. ExprKind::Field(base_expr, _) if matches!( base_expr.kind, ExprKind::Path(QPath::Resolved(_, Path { res: Res::Local(_), .. })) ) && can_partially_move_ty(cx, cx.typeck_results().expr_ty(base_expr)) => { // TODO: check if the local has been partially moved. Assume it has for now. false } _ => true, } } /// Checks if the expression can be moved into a closure as is. pub fn can_move_expr_to_closure(cx: &LateContext<'tcx>, expr: &'tcx Expr<'_>) -> bool { struct V<'cx, 'tcx> { cx: &'cx LateContext<'tcx>, loops: Vec, allow_closure: bool, } impl Visitor<'tcx> for V<'_, 'tcx> { type Map = ErasedMap<'tcx>; fn nested_visit_map(&mut self) -> NestedVisitorMap { NestedVisitorMap::None } fn visit_expr(&mut self, e: &'tcx Expr<'_>) { if !self.allow_closure { return; } if let ExprKind::Loop(b, ..) = e.kind { self.loops.push(e.hir_id); self.visit_block(b); self.loops.pop(); } else { self.allow_closure &= can_move_expr_to_closure_no_visit(self.cx, e, &self.loops); walk_expr(self, e); } } } let mut v = V { cx, allow_closure: true, loops: Vec::new(), }; v.visit_expr(expr); v.allow_closure } /// Returns the method names and argument list of nested method call expressions that make up /// `expr`. method/span lists are sorted with the most recent call first. pub fn method_calls<'tcx>( expr: &'tcx Expr<'tcx>, max_depth: usize, ) -> (Vec, Vec<&'tcx [Expr<'tcx>]>, Vec) { let mut method_names = Vec::with_capacity(max_depth); let mut arg_lists = Vec::with_capacity(max_depth); let mut spans = Vec::with_capacity(max_depth); let mut current = expr; for _ in 0..max_depth { if let ExprKind::MethodCall(path, span, args, _) = ¤t.kind { if args.iter().any(|e| e.span.from_expansion()) { break; } method_names.push(path.ident.name); arg_lists.push(&**args); spans.push(*span); current = &args[0]; } else { break; } } (method_names, arg_lists, spans) } /// Matches an `Expr` against a chain of methods, and return the matched `Expr`s. /// /// For example, if `expr` represents the `.baz()` in `foo.bar().baz()`, /// `method_chain_args(expr, &["bar", "baz"])` will return a `Vec` /// containing the `Expr`s for /// `.bar()` and `.baz()` pub fn method_chain_args<'a>(expr: &'a Expr<'_>, methods: &[&str]) -> Option]>> { let mut current = expr; let mut matched = Vec::with_capacity(methods.len()); for method_name in methods.iter().rev() { // method chains are stored last -> first if let ExprKind::MethodCall(path, _, args, _) = current.kind { if path.ident.name.as_str() == *method_name { if args.iter().any(|e| e.span.from_expansion()) { return None; } matched.push(args); // build up `matched` backwards current = &args[0]; // go to parent expression } else { return None; } } else { return None; } } // Reverse `matched` so that it is in the same order as `methods`. matched.reverse(); Some(matched) } /// Returns `true` if the provided `def_id` is an entrypoint to a program. pub fn is_entrypoint_fn(cx: &LateContext<'_>, def_id: DefId) -> bool { cx.tcx .entry_fn(()) .map_or(false, |(entry_fn_def_id, _)| def_id == entry_fn_def_id) } /// Returns `true` if the expression is in the program's `#[panic_handler]`. pub fn is_in_panic_handler(cx: &LateContext<'_>, e: &Expr<'_>) -> bool { let parent = cx.tcx.hir().get_parent_item(e.hir_id); let def_id = cx.tcx.hir().local_def_id(parent).to_def_id(); Some(def_id) == cx.tcx.lang_items().panic_impl() } /// Gets the name of the item the expression is in, if available. pub fn get_item_name(cx: &LateContext<'_>, expr: &Expr<'_>) -> Option { let parent_id = cx.tcx.hir().get_parent_item(expr.hir_id); match cx.tcx.hir().find(parent_id) { Some( Node::Item(Item { ident, .. }) | Node::TraitItem(TraitItem { ident, .. }) | Node::ImplItem(ImplItem { ident, .. }), ) => Some(ident.name), _ => None, } } pub struct ContainsName { pub name: Symbol, pub result: bool, } impl<'tcx> Visitor<'tcx> for ContainsName { type Map = Map<'tcx>; fn visit_name(&mut self, _: Span, name: Symbol) { if self.name == name { self.result = true; } } fn nested_visit_map(&mut self) -> NestedVisitorMap { NestedVisitorMap::None } } /// Checks if an `Expr` contains a certain name. pub fn contains_name(name: Symbol, expr: &Expr<'_>) -> bool { let mut cn = ContainsName { name, result: false }; cn.visit_expr(expr); cn.result } /// Returns `true` if `expr` contains a return expression pub fn contains_return(expr: &hir::Expr<'_>) -> bool { struct RetCallFinder { found: bool, } impl<'tcx> hir::intravisit::Visitor<'tcx> for RetCallFinder { type Map = Map<'tcx>; fn visit_expr(&mut self, expr: &'tcx hir::Expr<'_>) { if self.found { return; } if let hir::ExprKind::Ret(..) = &expr.kind { self.found = true; } else { hir::intravisit::walk_expr(self, expr); } } fn nested_visit_map(&mut self) -> hir::intravisit::NestedVisitorMap { hir::intravisit::NestedVisitorMap::None } } let mut visitor = RetCallFinder { found: false }; visitor.visit_expr(expr); visitor.found } struct FindMacroCalls<'a, 'b> { names: &'a [&'b str], result: Vec, } impl<'a, 'b, 'tcx> Visitor<'tcx> for FindMacroCalls<'a, 'b> { type Map = Map<'tcx>; fn visit_expr(&mut self, expr: &'tcx Expr<'_>) { if self.names.iter().any(|fun| is_expn_of(expr.span, fun).is_some()) { self.result.push(expr.span); } // and check sub-expressions intravisit::walk_expr(self, expr); } fn nested_visit_map(&mut self) -> NestedVisitorMap { NestedVisitorMap::None } } /// Finds calls of the specified macros in a function body. pub fn find_macro_calls(names: &[&str], body: &Body<'_>) -> Vec { let mut fmc = FindMacroCalls { names, result: Vec::new(), }; fmc.visit_expr(&body.value); fmc.result } /// Extends the span to the beginning of the spans line, incl. whitespaces. /// /// ```rust,ignore /// let x = (); /// // ^^ /// // will be converted to /// let x = (); /// // ^^^^^^^^^^^^^^ /// ``` fn line_span(cx: &T, span: Span) -> Span { let span = original_sp(span, DUMMY_SP); let source_map_and_line = cx.sess().source_map().lookup_line(span.lo()).unwrap(); let line_no = source_map_and_line.line; let line_start = source_map_and_line.sf.lines[line_no]; Span::new(line_start, span.hi(), span.ctxt()) } /// Gets the parent node, if any. pub fn get_parent_node(tcx: TyCtxt<'_>, id: HirId) -> Option> { tcx.hir().parent_iter(id).next().map(|(_, node)| node) } /// Gets the parent expression, if any –- this is useful to constrain a lint. pub fn get_parent_expr<'tcx>(cx: &LateContext<'tcx>, e: &Expr<'_>) -> Option<&'tcx Expr<'tcx>> { get_parent_expr_for_hir(cx, e.hir_id) } /// This retrieves the parent for the given `HirId` if it's an expression. This is useful for /// constraint lints pub fn get_parent_expr_for_hir<'tcx>(cx: &LateContext<'tcx>, hir_id: hir::HirId) -> Option<&'tcx Expr<'tcx>> { match get_parent_node(cx.tcx, hir_id) { Some(Node::Expr(parent)) => Some(parent), _ => None, } } pub fn get_enclosing_block<'tcx>(cx: &LateContext<'tcx>, hir_id: HirId) -> Option<&'tcx Block<'tcx>> { let map = &cx.tcx.hir(); let enclosing_node = map .get_enclosing_scope(hir_id) .and_then(|enclosing_id| map.find(enclosing_id)); enclosing_node.and_then(|node| match node { Node::Block(block) => Some(block), Node::Item(&Item { kind: ItemKind::Fn(_, _, eid), .. }) | Node::ImplItem(&ImplItem { kind: ImplItemKind::Fn(_, eid), .. }) => match cx.tcx.hir().body(eid).value.kind { ExprKind::Block(block, _) => Some(block), _ => None, }, _ => None, }) } /// Gets the loop or closure enclosing the given expression, if any. pub fn get_enclosing_loop_or_closure(tcx: TyCtxt<'tcx>, expr: &Expr<'_>) -> Option<&'tcx Expr<'tcx>> { let map = tcx.hir(); for (_, node) in map.parent_iter(expr.hir_id) { match node { Node::Expr( e @ Expr { kind: ExprKind::Loop(..) | ExprKind::Closure(..), .. }, ) => return Some(e), Node::Expr(_) | Node::Stmt(_) | Node::Block(_) | Node::Local(_) | Node::Arm(_) => (), _ => break, } } None } /// Gets the parent node if it's an impl block. pub fn get_parent_as_impl(tcx: TyCtxt<'_>, id: HirId) -> Option<&Impl<'_>> { let map = tcx.hir(); match map.parent_iter(id).next() { Some(( _, Node::Item(Item { kind: ItemKind::Impl(imp), .. }), )) => Some(imp), _ => None, } } /// Checks if the given expression is the else clause of either an `if` or `if let` expression. pub fn is_else_clause(tcx: TyCtxt<'_>, expr: &Expr<'_>) -> bool { let map = tcx.hir(); let mut iter = map.parent_iter(expr.hir_id); match iter.next() { Some((arm_id, Node::Arm(..))) => matches!( iter.next(), Some(( _, Node::Expr(Expr { kind: ExprKind::Match(_, [_, else_arm], MatchSource::IfLetDesugar { .. }), .. }) )) if else_arm.hir_id == arm_id ), Some(( _, Node::Expr(Expr { kind: ExprKind::If(_, _, Some(else_expr)), .. }), )) => else_expr.hir_id == expr.hir_id, _ => false, } } /// Checks whether the given expression is a constant integer of the given value. /// unlike `is_integer_literal`, this version does const folding pub fn is_integer_const(cx: &LateContext<'_>, e: &Expr<'_>, value: u128) -> bool { if is_integer_literal(e, value) { return true; } let map = cx.tcx.hir(); let parent_item = map.get_parent_item(e.hir_id); if let Some((Constant::Int(v), _)) = map .maybe_body_owned_by(parent_item) .and_then(|body_id| constant(cx, cx.tcx.typeck_body(body_id), e)) { value == v } else { false } } /// Checks whether the given expression is a constant literal of the given value. pub fn is_integer_literal(expr: &Expr<'_>, value: u128) -> bool { // FIXME: use constant folding if let ExprKind::Lit(ref spanned) = expr.kind { if let LitKind::Int(v, _) = spanned.node { return v == value; } } false } /// Returns `true` if the given `Expr` has been coerced before. /// /// Examples of coercions can be found in the Nomicon at /// . /// /// See `rustc_middle::ty::adjustment::Adjustment` and `rustc_typeck::check::coercion` for more /// information on adjustments and coercions. pub fn is_adjusted(cx: &LateContext<'_>, e: &Expr<'_>) -> bool { cx.typeck_results().adjustments().get(e.hir_id).is_some() } /// Returns the pre-expansion span if is this comes from an expansion of the /// macro `name`. /// See also `is_direct_expn_of`. #[must_use] pub fn is_expn_of(mut span: Span, name: &str) -> Option { loop { if span.from_expansion() { let data = span.ctxt().outer_expn_data(); let new_span = data.call_site; if let ExpnKind::Macro(MacroKind::Bang, mac_name) = data.kind { if mac_name.as_str() == name { return Some(new_span); } } span = new_span; } else { return None; } } } /// Returns the pre-expansion span if the span directly comes from an expansion /// of the macro `name`. /// The difference with `is_expn_of` is that in /// ```rust,ignore /// foo!(bar!(42)); /// ``` /// `42` is considered expanded from `foo!` and `bar!` by `is_expn_of` but only /// `bar!` by /// `is_direct_expn_of`. #[must_use] pub fn is_direct_expn_of(span: Span, name: &str) -> Option { if span.from_expansion() { let data = span.ctxt().outer_expn_data(); let new_span = data.call_site; if let ExpnKind::Macro(MacroKind::Bang, mac_name) = data.kind { if mac_name.as_str() == name { return Some(new_span); } } } None } /// Convenience function to get the return type of a function. pub fn return_ty<'tcx>(cx: &LateContext<'tcx>, fn_item: hir::HirId) -> Ty<'tcx> { let fn_def_id = cx.tcx.hir().local_def_id(fn_item); let ret_ty = cx.tcx.fn_sig(fn_def_id).output(); cx.tcx.erase_late_bound_regions(ret_ty) } /// Checks if an expression is constructing a tuple-like enum variant or struct pub fn is_ctor_or_promotable_const_function(cx: &LateContext<'_>, expr: &Expr<'_>) -> bool { if let ExprKind::Call(fun, _) = expr.kind { if let ExprKind::Path(ref qp) = fun.kind { let res = cx.qpath_res(qp, fun.hir_id); return match res { def::Res::Def(DefKind::Variant | DefKind::Ctor(..), ..) => true, def::Res::Def(_, def_id) => cx.tcx.is_promotable_const_fn(def_id), _ => false, }; } } false } /// Returns `true` if a pattern is refutable. // TODO: should be implemented using rustc/mir_build/thir machinery pub fn is_refutable(cx: &LateContext<'_>, pat: &Pat<'_>) -> bool { fn is_enum_variant(cx: &LateContext<'_>, qpath: &QPath<'_>, id: HirId) -> bool { matches!( cx.qpath_res(qpath, id), def::Res::Def(DefKind::Variant, ..) | Res::Def(DefKind::Ctor(def::CtorOf::Variant, _), _) ) } fn are_refutable<'a, I: Iterator>>(cx: &LateContext<'_>, mut i: I) -> bool { i.any(|pat| is_refutable(cx, pat)) } match pat.kind { PatKind::Wild => false, PatKind::Binding(_, _, _, pat) => pat.map_or(false, |pat| is_refutable(cx, pat)), PatKind::Box(pat) | PatKind::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(pats) => { // TODO: should be the honest check, that pats is exhaustive set are_refutable(cx, pats.iter().map(|pat| &**pat)) }, PatKind::Tuple(pats, _) => are_refutable(cx, pats.iter().map(|pat| &**pat)), PatKind::Struct(ref qpath, fields, _) => { is_enum_variant(cx, qpath, pat.hir_id) || are_refutable(cx, fields.iter().map(|field| &*field.pat)) }, PatKind::TupleStruct(ref qpath, pats, _) => { is_enum_variant(cx, qpath, pat.hir_id) || are_refutable(cx, pats.iter().map(|pat| &**pat)) }, PatKind::Slice(head, ref middle, tail) => { match &cx.typeck_results().node_type(pat.hir_id).kind() { rustc_ty::Slice(..) => { // [..] is the only irrefutable slice pattern. !head.is_empty() || middle.is_none() || !tail.is_empty() }, rustc_ty::Array(..) => { are_refutable(cx, head.iter().chain(middle).chain(tail.iter()).map(|pat| &**pat)) }, _ => { // unreachable!() true }, } }, } } /// If the pattern is an `or` pattern, call the function once for each sub pattern. Otherwise, call /// the function once on the given pattern. pub fn recurse_or_patterns<'tcx, F: FnMut(&'tcx Pat<'tcx>)>(pat: &'tcx Pat<'tcx>, mut f: F) { if let PatKind::Or(pats) = pat.kind { pats.iter().copied().for_each(f); } else { f(pat); } } /// Checks for the `#[automatically_derived]` attribute all `#[derive]`d /// implementations have. pub fn is_automatically_derived(attrs: &[ast::Attribute]) -> bool { attrs.iter().any(|attr| attr.has_name(sym::automatically_derived)) } /// Remove blocks around an expression. /// /// Ie. `x`, `{ x }` and `{{{{ x }}}}` all give `x`. `{ x; y }` and `{}` return /// themselves. pub fn remove_blocks<'tcx>(mut expr: &'tcx Expr<'tcx>) -> &'tcx Expr<'tcx> { while let ExprKind::Block(block, ..) = expr.kind { match (block.stmts.is_empty(), block.expr.as_ref()) { (true, Some(e)) => expr = e, _ => break, } } expr } pub fn is_self(slf: &Param<'_>) -> bool { if let PatKind::Binding(.., name, _) = slf.pat.kind { name.name == kw::SelfLower } else { false } } pub fn is_self_ty(slf: &hir::Ty<'_>) -> bool { if_chain! { if let TyKind::Path(QPath::Resolved(None, path)) = slf.kind; if let Res::SelfTy(..) = path.res; then { return true } } false } pub fn iter_input_pats<'tcx>(decl: &FnDecl<'_>, body: &'tcx Body<'_>) -> impl Iterator> { (0..decl.inputs.len()).map(move |i| &body.params[i]) } /// Checks if a given expression is a match expression expanded from the `?` /// operator or the `try` macro. pub fn is_try<'tcx>(cx: &LateContext<'_>, expr: &'tcx Expr<'tcx>) -> Option<&'tcx Expr<'tcx>> { fn is_ok(cx: &LateContext<'_>, arm: &Arm<'_>) -> bool { if_chain! { if let PatKind::TupleStruct(ref path, pat, None) = arm.pat.kind; if is_lang_ctor(cx, path, ResultOk); if let PatKind::Binding(_, hir_id, _, None) = pat[0].kind; if path_to_local_id(arm.body, hir_id); then { return true; } } false } fn is_err(cx: &LateContext<'_>, arm: &Arm<'_>) -> bool { if let PatKind::TupleStruct(ref path, _, _) = arm.pat.kind { is_lang_ctor(cx, path, ResultErr) } else { false } } if let ExprKind::Match(_, arms, ref source) = expr.kind { // desugared from a `?` operator if let MatchSource::TryDesugar = *source { return Some(expr); } if_chain! { if arms.len() == 2; if arms[0].guard.is_none(); if arms[1].guard.is_none(); if (is_ok(cx, &arms[0]) && is_err(cx, &arms[1])) || (is_ok(cx, &arms[1]) && is_err(cx, &arms[0])); then { return Some(expr); } } } None } /// Returns `true` if the lint is allowed in the current context /// /// Useful for skipping long running code when it's unnecessary 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 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: rustc_ty::IntTy) -> u64 { Integer::from_int_ty(&tcx, ity).size().bits() } #[allow(clippy::cast_possible_wrap)] /// Turn a constant int byte representation into an i128 pub fn sext(tcx: TyCtxt<'_>, u: u128, ity: rustc_ty::IntTy) -> i128 { let amt = 128 - int_bits(tcx, ity); ((u as i128) << amt) >> amt } #[allow(clippy::cast_sign_loss)] /// clip unused bytes pub fn unsext(tcx: TyCtxt<'_>, u: i128, ity: rustc_ty::IntTy) -> u128 { let amt = 128 - int_bits(tcx, ity); ((u as u128) << amt) >> amt } /// clip unused bytes pub fn clip(tcx: TyCtxt<'_>, u: u128, ity: rustc_ty::UintTy) -> u128 { let bits = Integer::from_uint_ty(&tcx, ity).size().bits(); let amt = 128 - bits; (u << amt) >> amt } pub fn any_parent_is_automatically_derived(tcx: TyCtxt<'_>, node: HirId) -> bool { let map = &tcx.hir(); let mut prev_enclosing_node = None; let mut enclosing_node = node; while Some(enclosing_node) != prev_enclosing_node { if is_automatically_derived(map.attrs(enclosing_node)) { return true; } prev_enclosing_node = Some(enclosing_node); enclosing_node = map.get_parent_item(enclosing_node); } false } /// Matches a function call with the given path and returns the arguments. /// /// Usage: /// /// ```rust,ignore /// if let Some(args) = match_function_call(cx, cmp_max_call, &paths::CMP_MAX); /// ``` pub fn match_function_call<'tcx>( cx: &LateContext<'tcx>, expr: &'tcx Expr<'_>, path: &[&str], ) -> Option<&'tcx [Expr<'tcx>]> { if_chain! { if let ExprKind::Call(fun, args) = expr.kind; if let ExprKind::Path(ref qpath) = fun.kind; if let Some(fun_def_id) = cx.qpath_res(qpath, fun.hir_id).opt_def_id(); if match_def_path(cx, fun_def_id, path); then { return Some(args) } }; None } /// Checks if the given `DefId` matches any of the paths. Returns the index of matching path, if /// any. pub fn match_any_def_paths(cx: &LateContext<'_>, did: DefId, paths: &[&[&str]]) -> Option { let search_path = cx.get_def_path(did); paths .iter() .position(|p| p.iter().map(|x| Symbol::intern(x)).eq(search_path.iter().copied())) } /// Checks if the given `DefId` matches the path. pub fn match_def_path<'tcx>(cx: &LateContext<'tcx>, did: DefId, syms: &[&str]) -> bool { // We should probably move to Symbols in Clippy as well rather than interning every time. let path = cx.get_def_path(did); syms.iter().map(|x| Symbol::intern(x)).eq(path.iter().copied()) } pub fn match_panic_call(cx: &LateContext<'_>, expr: &'tcx Expr<'_>) -> Option<&'tcx Expr<'tcx>> { if let ExprKind::Call(func, [arg]) = expr.kind { expr_path_res(cx, func) .opt_def_id() .map_or(false, |id| match_panic_def_id(cx, id)) .then(|| arg) } else { None } } pub fn match_panic_def_id(cx: &LateContext<'_>, did: DefId) -> bool { match_any_def_paths( cx, did, &[ &paths::BEGIN_PANIC, &paths::BEGIN_PANIC_FMT, &paths::PANIC_ANY, &paths::PANICKING_PANIC, &paths::PANICKING_PANIC_FMT, &paths::PANICKING_PANIC_STR, ], ) .is_some() } /// Returns the list of condition expressions and the list of blocks in a /// sequence of `if/else`. /// E.g., this returns `([a, b], [c, d, e])` for the expression /// `if a { c } else if b { d } else { e }`. pub fn if_sequence<'tcx>(mut expr: &'tcx Expr<'tcx>) -> (Vec<&'tcx Expr<'tcx>>, Vec<&'tcx Block<'tcx>>) { let mut conds = Vec::new(); let mut blocks: Vec<&Block<'_>> = Vec::new(); while let ExprKind::If(cond, then_expr, ref else_expr) = expr.kind { conds.push(cond); if let ExprKind::Block(block, _) = then_expr.kind { blocks.push(block); } else { panic!("ExprKind::If node is not an ExprKind::Block"); } if let Some(else_expr) = *else_expr { expr = else_expr; } else { break; } } // final `else {..}` if !blocks.is_empty() { if let ExprKind::Block(block, _) = expr.kind { blocks.push(block); } } (conds, blocks) } /// Checks if the given function kind is an async function. pub fn is_async_fn(kind: FnKind<'_>) -> bool { matches!(kind, FnKind::ItemFn(_, _, header, _) if header.asyncness == IsAsync::Async) } /// Peels away all the compiler generated code surrounding the body of an async function, pub fn get_async_fn_body(tcx: TyCtxt<'tcx>, body: &Body<'_>) -> Option<&'tcx Expr<'tcx>> { if let ExprKind::Call( _, &[Expr { kind: ExprKind::Closure(_, _, body, _, _), .. }], ) = body.value.kind { if let ExprKind::Block( Block { stmts: [], expr: Some(Expr { kind: ExprKind::DropTemps(expr), .. }), .. }, _, ) = tcx.hir().body(body).value.kind { return Some(expr); } }; None } // Finds the `#[must_use]` attribute, if any pub fn must_use_attr(attrs: &[Attribute]) -> Option<&Attribute> { attrs.iter().find(|a| a.has_name(sym::must_use)) } // check if expr is calling method or function with #[must_use] attribute pub fn is_must_use_func_call(cx: &LateContext<'_>, expr: &Expr<'_>) -> bool { let did = match expr.kind { ExprKind::Call(path, _) => if_chain! { if let ExprKind::Path(ref qpath) = path.kind; if let def::Res::Def(_, did) = cx.qpath_res(qpath, path.hir_id); then { Some(did) } else { None } }, ExprKind::MethodCall(_, _, _, _) => cx.typeck_results().type_dependent_def_id(expr.hir_id), _ => None, }; did.map_or(false, |did| must_use_attr(cx.tcx.get_attrs(did)).is_some()) } /// Checks if an expression represents the identity function /// Only examines closures and `std::convert::identity` pub fn is_expr_identity_function(cx: &LateContext<'_>, expr: &Expr<'_>) -> bool { /// Checks if a function's body represents the identity function. Looks for bodies of the form: /// * `|x| x` /// * `|x| return x` /// * `|x| { return x }` /// * `|x| { return x; }` fn is_body_identity_function(cx: &LateContext<'_>, func: &Body<'_>) -> bool { let id = if_chain! { if let [param] = func.params; if let PatKind::Binding(_, id, _, _) = param.pat.kind; then { id } else { return false; } }; let mut expr = &func.value; loop { match expr.kind { #[rustfmt::skip] ExprKind::Block(&Block { stmts: [], expr: Some(e), .. }, _, ) | ExprKind::Ret(Some(e)) => expr = e, #[rustfmt::skip] ExprKind::Block(&Block { stmts: [stmt], expr: None, .. }, _) => { if_chain! { if let StmtKind::Semi(e) | StmtKind::Expr(e) = stmt.kind; if let ExprKind::Ret(Some(ret_val)) = e.kind; then { expr = ret_val; } else { return false; } } }, _ => return path_to_local_id(expr, id) && cx.typeck_results().expr_adjustments(expr).is_empty(), } } } match expr.kind { ExprKind::Closure(_, _, body_id, _, _) => is_body_identity_function(cx, cx.tcx.hir().body(body_id)), ExprKind::Path(ref path) => is_qpath_def_path(cx, path, expr.hir_id, &paths::CONVERT_IDENTITY), _ => false, } } /// Gets the node where an expression is either used, or it's type is unified with another branch. pub fn get_expr_use_or_unification_node(tcx: TyCtxt<'tcx>, expr: &Expr<'_>) -> Option> { let map = tcx.hir(); let mut child_id = expr.hir_id; let mut iter = map.parent_iter(child_id); loop { match iter.next() { None => break None, Some((id, Node::Block(_))) => child_id = id, Some((id, Node::Arm(arm))) if arm.body.hir_id == child_id => child_id = id, Some((_, Node::Expr(expr))) => match expr.kind { ExprKind::Match(_, [arm], _) if arm.hir_id == child_id => child_id = expr.hir_id, ExprKind::Block(..) | ExprKind::DropTemps(_) => child_id = expr.hir_id, ExprKind::If(_, then_expr, None) if then_expr.hir_id == child_id => break None, _ => break Some(Node::Expr(expr)), }, Some((_, node)) => break Some(node), } } } /// Checks if the result of an expression is used, or it's type is unified with another branch. pub fn is_expr_used_or_unified(tcx: TyCtxt<'_>, expr: &Expr<'_>) -> bool { !matches!( get_expr_use_or_unification_node(tcx, expr), None | Some(Node::Stmt(Stmt { kind: StmtKind::Expr(_) | StmtKind::Semi(_) | StmtKind::Local(Local { pat: Pat { kind: PatKind::Wild, .. }, .. }), .. })) ) } /// Checks if the expression is the final expression returned from a block. pub fn is_expr_final_block_expr(tcx: TyCtxt<'_>, expr: &Expr<'_>) -> bool { matches!(get_parent_node(tcx, expr.hir_id), Some(Node::Block(..))) } pub fn is_no_std_crate(cx: &LateContext<'_>) -> bool { cx.tcx.hir().attrs(hir::CRATE_HIR_ID).iter().any(|attr| { if let ast::AttrKind::Normal(ref attr, _) = attr.kind { attr.path == sym::no_std } else { false } }) } /// Check if parent of a hir node is a trait implementation block. /// For example, `f` in /// ```rust,ignore /// impl Trait for S { /// fn f() {} /// } /// ``` pub fn is_trait_impl_item(cx: &LateContext<'_>, hir_id: HirId) -> bool { if let Some(Node::Item(item)) = cx.tcx.hir().find(cx.tcx.hir().get_parent_node(hir_id)) { matches!(item.kind, ItemKind::Impl(hir::Impl { of_trait: Some(_), .. })) } else { false } } /// Check if it's even possible to satisfy the `where` clause for the item. /// /// `trivial_bounds` feature allows functions with unsatisfiable bounds, for example: /// /// ```ignore /// fn foo() where i32: Iterator { /// for _ in 2i32 {} /// } /// ``` pub fn fn_has_unsatisfiable_preds(cx: &LateContext<'_>, did: DefId) -> bool { use rustc_trait_selection::traits; let predicates = cx .tcx .predicates_of(did) .predicates .iter() .filter_map(|(p, _)| if p.is_global() { Some(*p) } else { None }); traits::impossible_predicates( cx.tcx, traits::elaborate_predicates(cx.tcx, predicates) .map(|o| o.predicate) .collect::>(), ) } /// Returns the `DefId` of the callee if the given expression is a function or method call. pub fn fn_def_id(cx: &LateContext<'_>, expr: &Expr<'_>) -> Option { match &expr.kind { ExprKind::MethodCall(..) => cx.typeck_results().type_dependent_def_id(expr.hir_id), ExprKind::Call( Expr { kind: ExprKind::Path(qpath), hir_id: path_hir_id, .. }, .., ) => cx.typeck_results().qpath_res(qpath, *path_hir_id).opt_def_id(), _ => None, } } /// This function checks if any of the lints in the slice is enabled for the provided `HirId`. /// A lint counts as enabled with any of the levels: `Level::Forbid` | `Level::Deny` | `Level::Warn` /// /// ```ignore /// #[deny(clippy::YOUR_AWESOME_LINT)] /// println!("Hello, World!"); // <- Clippy code: run_lints(cx, &[YOUR_AWESOME_LINT], id) == true /// /// #[allow(clippy::YOUR_AWESOME_LINT)] /// println!("See you soon!"); // <- Clippy code: run_lints(cx, &[YOUR_AWESOME_LINT], id) == false /// ``` pub fn run_lints(cx: &LateContext<'_>, lints: &[&'static Lint], id: HirId) -> bool { lints.iter().any(|lint| { matches!( cx.tcx.lint_level_at_node(lint, id), (Level::Forbid | Level::Deny | Level::Warn, _) ) }) } /// Returns Option where String is a textual representation of the type encapsulated in the /// slice iff the given expression is a slice of primitives (as defined in the /// `is_recursively_primitive_type` function) and None otherwise. pub fn is_slice_of_primitives(cx: &LateContext<'_>, expr: &Expr<'_>) -> Option { let expr_type = cx.typeck_results().expr_ty_adjusted(expr); let expr_kind = expr_type.kind(); let is_primitive = match expr_kind { rustc_ty::Slice(element_type) => is_recursively_primitive_type(element_type), rustc_ty::Ref(_, inner_ty, _) if matches!(inner_ty.kind(), &rustc_ty::Slice(_)) => { if let rustc_ty::Slice(element_type) = inner_ty.kind() { is_recursively_primitive_type(element_type) } else { unreachable!() } }, _ => false, }; if is_primitive { // if we have wrappers like Array, Slice or Tuple, print these // and get the type enclosed in the slice ref match expr_type.peel_refs().walk().nth(1).unwrap().expect_ty().kind() { rustc_ty::Slice(..) => return Some("slice".into()), rustc_ty::Array(..) => return Some("array".into()), rustc_ty::Tuple(..) => return Some("tuple".into()), _ => { // is_recursively_primitive_type() should have taken care // of the rest and we can rely on the type that is found let refs_peeled = expr_type.peel_refs(); return Some(refs_peeled.walk().last().unwrap().to_string()); }, } } None } /// returns list of all pairs (a, b) from `exprs` such that `eq(a, b)` /// `hash` must be comformed with `eq` pub fn search_same(exprs: &[T], hash: Hash, eq: Eq) -> Vec<(&T, &T)> where Hash: Fn(&T) -> u64, Eq: Fn(&T, &T) -> bool, { match exprs { [a, b] if eq(a, b) => return vec![(a, b)], _ if exprs.len() <= 2 => return vec![], _ => {}, } let mut match_expr_list: Vec<(&T, &T)> = Vec::new(); let mut map: UnhashMap> = UnhashMap::with_capacity_and_hasher(exprs.len(), BuildHasherDefault::default()); for expr in exprs { match map.entry(hash(expr)) { Entry::Occupied(mut o) => { for o in o.get() { if eq(o, expr) { match_expr_list.push((o, expr)); } } o.get_mut().push(expr); }, Entry::Vacant(v) => { v.insert(vec![expr]); }, } } match_expr_list } /// Peels off all references on the pattern. Returns the underlying pattern and the number of /// references removed. pub fn peel_hir_pat_refs(pat: &'a Pat<'a>) -> (&'a Pat<'a>, usize) { fn peel(pat: &'a Pat<'a>, count: usize) -> (&'a Pat<'a>, usize) { if let PatKind::Ref(pat, _) = pat.kind { peel(pat, count + 1) } else { (pat, count) } } peel(pat, 0) } /// Peels of expressions while the given closure returns `Some`. pub fn peel_hir_expr_while<'tcx>( mut expr: &'tcx Expr<'tcx>, mut f: impl FnMut(&'tcx Expr<'tcx>) -> Option<&'tcx Expr<'tcx>>, ) -> &'tcx Expr<'tcx> { while let Some(e) = f(expr) { expr = e; } expr } /// Peels off up to the given number of references on the expression. Returns the underlying /// expression and the number of references removed. pub fn peel_n_hir_expr_refs(expr: &'a Expr<'a>, count: usize) -> (&'a Expr<'a>, usize) { let mut remaining = count; let e = peel_hir_expr_while(expr, |e| match e.kind { ExprKind::AddrOf(BorrowKind::Ref, _, e) if remaining != 0 => { remaining -= 1; Some(e) }, _ => None, }); (e, count - remaining) } /// Peels off all references on the expression. Returns the underlying expression and the number of /// references removed. pub fn peel_hir_expr_refs(expr: &'a Expr<'a>) -> (&'a Expr<'a>, usize) { let mut count = 0; let e = peel_hir_expr_while(expr, |e| match e.kind { ExprKind::AddrOf(BorrowKind::Ref, _, e) => { count += 1; Some(e) }, _ => None, }); (e, count) } /// 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. pub fn peel_ref_operators<'hir>(cx: &LateContext<'_>, mut expr: &'hir Expr<'hir>) -> &'hir Expr<'hir> { loop { match expr.kind { ExprKind::AddrOf(_, _, e) => expr = e, ExprKind::Unary(UnOp::Deref, e) if cx.typeck_results().expr_ty(e).is_ref() => expr = e, _ => break, } } expr } #[macro_export] macro_rules! unwrap_cargo_metadata { ($cx: ident, $lint: ident, $deps: expr) => {{ let mut command = cargo_metadata::MetadataCommand::new(); if !$deps { command.no_deps(); } match command.exec() { Ok(metadata) => metadata, Err(err) => { span_lint($cx, $lint, DUMMY_SP, &format!("could not read cargo metadata: {}", err)); return; }, } }}; } pub fn is_hir_ty_cfg_dependant(cx: &LateContext<'_>, ty: &hir::Ty<'_>) -> bool { if_chain! { if let TyKind::Path(QPath::Resolved(_, path)) = ty.kind; if let Res::Def(_, def_id) = path.res; then { cx.tcx.has_attr(def_id, sym::cfg) || cx.tcx.has_attr(def_id, sym::cfg_attr) } else { false } } } /// Checks whether item either has `test` attribute applied, or /// is a module with `test` in its name. pub fn is_test_module_or_function(tcx: TyCtxt<'_>, item: &Item<'_>) -> bool { if let Some(def_id) = tcx.hir().opt_local_def_id(item.hir_id()) { if tcx.has_attr(def_id.to_def_id(), sym::test) { return true; } } matches!(item.kind, ItemKind::Mod(..)) && item.ident.name.as_str().contains("test") }