From 8611a0bb5cc401f90162449eaa82295ef5f70d68 Mon Sep 17 00:00:00 2001 From: Samuel Moelius Date: Sat, 1 Oct 2022 04:48:01 -0400 Subject: [PATCH] Expand `unnecessary_def_path` lint --- clippy_lints/src/lib.rs | 2 +- .../internal_lints/unnecessary_def_path.rs | 181 +++++++++++++----- tests/ui-internal/unnecessary_def_path.fixed | 6 +- tests/ui-internal/unnecessary_def_path.rs | 6 +- .../unnecessary_def_path_hardcoded_path.rs | 16 ++ ...unnecessary_def_path_hardcoded_path.stderr | 27 +++ 6 files changed, 182 insertions(+), 56 deletions(-) create mode 100644 tests/ui-internal/unnecessary_def_path_hardcoded_path.rs create mode 100644 tests/ui-internal/unnecessary_def_path_hardcoded_path.stderr diff --git a/clippy_lints/src/lib.rs b/clippy_lints/src/lib.rs index b2ee58ec7..893410dbf 100644 --- a/clippy_lints/src/lib.rs +++ b/clippy_lints/src/lib.rs @@ -542,7 +542,7 @@ pub fn register_plugins(store: &mut rustc_lint::LintStore, sess: &Session, conf: store.register_late_pass(|_| { Box::::default() }); - store.register_late_pass(|_| Box::new(utils::internal_lints::unnecessary_def_path::UnnecessaryDefPath)); + store.register_late_pass(|_| Box::::default()); store.register_late_pass(|_| Box::new(utils::internal_lints::outer_expn_data_pass::OuterExpnDataPass)); store.register_late_pass(|_| Box::new(utils::internal_lints::msrv_attr_impl::MsrvAttrImpl)); } diff --git a/clippy_lints/src/utils/internal_lints/unnecessary_def_path.rs b/clippy_lints/src/utils/internal_lints/unnecessary_def_path.rs index 9b524d5b0..0a3852c98 100644 --- a/clippy_lints/src/utils/internal_lints/unnecessary_def_path.rs +++ b/clippy_lints/src/utils/internal_lints/unnecessary_def_path.rs @@ -1,18 +1,20 @@ -use clippy_utils::diagnostics::span_lint_and_then; +use clippy_utils::diagnostics::{span_lint_and_help, span_lint_and_then}; use clippy_utils::source::snippet_with_applicability; use clippy_utils::{def_path_res, is_lint_allowed, match_any_def_paths, peel_hir_expr_refs}; use if_chain::if_chain; use rustc_ast::ast::LitKind; +use rustc_data_structures::fx::FxHashSet; use rustc_errors::Applicability; use rustc_hir as hir; use rustc_hir::def::{DefKind, Namespace, Res}; use rustc_hir::def_id::DefId; -use rustc_hir::{ExprKind, Local, Mutability, Node}; +use rustc_hir::{Expr, ExprKind, Local, Mutability, Node}; use rustc_lint::{LateContext, LateLintPass}; use rustc_middle::mir::interpret::{Allocation, ConstValue, GlobalAlloc}; use rustc_middle::ty::{self, AssocKind, DefIdTree, Ty}; -use rustc_session::{declare_lint_pass, declare_tool_lint}; +use rustc_session::{declare_tool_lint, impl_lint_pass}; use rustc_span::symbol::{Ident, Symbol}; +use rustc_span::Span; use std::str; @@ -38,11 +40,56 @@ declare_clippy_lint! { "using a def path when a diagnostic item or a `LangItem` is available" } -declare_lint_pass!(UnnecessaryDefPath => [UNNECESSARY_DEF_PATH]); +impl_lint_pass!(UnnecessaryDefPath => [UNNECESSARY_DEF_PATH]); + +#[derive(Default)] +pub struct UnnecessaryDefPath { + array_def_ids: FxHashSet<(DefId, Span)>, + linted_def_ids: FxHashSet, +} -#[allow(clippy::too_many_lines)] impl<'tcx> LateLintPass<'tcx> for UnnecessaryDefPath { fn check_expr(&mut self, cx: &LateContext<'tcx>, expr: &'tcx hir::Expr<'_>) { + if is_lint_allowed(cx, UNNECESSARY_DEF_PATH, expr.hir_id) { + return; + } + + match expr.kind { + ExprKind::Call(func, args) => self.check_call(cx, func, args, expr.span), + ExprKind::Array(elements) => self.check_array(cx, elements, expr.span), + _ => {}, + } + } + + fn check_crate_post(&mut self, cx: &LateContext<'tcx>) { + for &(def_id, span) in &self.array_def_ids { + if self.linted_def_ids.contains(&def_id) { + continue; + } + + let (msg, sugg) = if let Some(sym) = cx.tcx.get_diagnostic_name(def_id) { + ("diagnostic item", format!("sym::{sym}")) + } else if let Some(sym) = get_lang_item_name(cx, def_id) { + ("language item", format!("LangItem::{sym}")) + } else { + continue; + }; + + span_lint_and_help( + cx, + UNNECESSARY_DEF_PATH, + span, + &format!("hardcoded path to a {msg}"), + None, + &format!("convert all references to use `{sugg}`"), + ); + } + } +} + +impl UnnecessaryDefPath { + #[allow(clippy::too_many_lines)] + fn check_call(&mut self, cx: &LateContext<'_>, func: &Expr<'_>, args: &[Expr<'_>], span: Span) { enum Item { LangItem(Symbol), DiagnosticItem(Symbol), @@ -54,12 +101,8 @@ impl<'tcx> LateLintPass<'tcx> for UnnecessaryDefPath { &["clippy_utils", "is_expr_path_def_path"], ]; - if is_lint_allowed(cx, UNNECESSARY_DEF_PATH, expr.hir_id) { - return; - } - if_chain! { - if let ExprKind::Call(func, [cx_arg, def_arg, args@..]) = expr.kind; + if let [cx_arg, def_arg, args@..] = args; if let ExprKind::Path(path) = &func.kind; if let Some(id) = cx.qpath_res(path, func.hir_id).opt_def_id(); if let Some(which_path) = match_any_def_paths(cx, id, PATHS); @@ -67,29 +110,8 @@ impl<'tcx> LateLintPass<'tcx> for UnnecessaryDefPath { // Extract the path to the matched type if let Some(segments) = path_to_matched_type(cx, item_arg); let segments: Vec<&str> = segments.iter().map(|sym| &**sym).collect(); - if let Some(def_id) = def_path_res(cx, &segments[..], None).opt_def_id(); + if let Some(def_id) = inherent_def_path_res(cx, &segments[..]); then { - // def_path_res will match field names before anything else, but for this we want to match - // inherent functions first. - let def_id = if cx.tcx.def_kind(def_id) == DefKind::Field { - let method_name = *segments.last().unwrap(); - cx.tcx.def_key(def_id).parent - .and_then(|parent_idx| - cx.tcx.inherent_impls(DefId { index: parent_idx, krate: def_id.krate }).iter() - .find_map(|impl_id| cx.tcx.associated_items(*impl_id) - .find_by_name_and_kind( - cx.tcx, - Ident::from_str(method_name), - AssocKind::Fn, - *impl_id, - ) - ) - ) - .map_or(def_id, |item| item.def_id) - } else { - def_id - }; - // Check if the target item is a diagnostic item or LangItem. let (msg, item) = if let Some(item_name) = cx.tcx.diagnostic_items(def_id.krate).id_to_name.get(&def_id) @@ -98,9 +120,7 @@ impl<'tcx> LateLintPass<'tcx> for UnnecessaryDefPath { "use of a def path to a diagnostic item", Item::DiagnosticItem(*item_name), ) - } else if let Some(lang_item) = cx.tcx.lang_items().items().iter().position(|id| *id == Some(def_id)) { - let lang_items = def_path_res(cx, &["rustc_hir", "lang_items", "LangItem"], Some(Namespace::TypeNS)).def_id(); - let item_name = cx.tcx.adt_def(lang_items).variants().iter().nth(lang_item).unwrap().name; + } else if let Some(item_name) = get_lang_item_name(cx, def_id) { ( "use of a def path to a `LangItem`", Item::LangItem(item_name), @@ -168,10 +188,10 @@ impl<'tcx> LateLintPass<'tcx> for UnnecessaryDefPath { span_lint_and_then( cx, UNNECESSARY_DEF_PATH, - expr.span, + span, msg, |diag| { - diag.span_suggestion(expr.span, "try", sugg, app); + diag.span_suggestion(span, "try", sugg, app); if with_note { diag.help( "if this `DefId` came from a constructor expression or pattern then the \ @@ -180,9 +200,19 @@ impl<'tcx> LateLintPass<'tcx> for UnnecessaryDefPath { } }, ); + + self.linted_def_ids.insert(def_id); } } } + + fn check_array(&mut self, cx: &LateContext<'_>, elements: &[Expr<'_>], span: Span) { + let Some(path) = path_from_array(elements) else { return }; + + if let Some(def_id) = inherent_def_path_res(cx, &path.iter().map(AsRef::as_ref).collect::>()) { + self.array_def_ids.insert((def_id, span)); + } + } } fn path_to_matched_type(cx: &LateContext<'_>, expr: &hir::Expr<'_>) -> Option> { @@ -209,18 +239,7 @@ fn path_to_matched_type(cx: &LateContext<'_>, expr: &hir::Expr<'_>) -> Option None, }, - ExprKind::Array(exprs) => exprs - .iter() - .map(|expr| { - if let ExprKind::Lit(lit) = &expr.kind { - if let LitKind::Str(sym, _) = lit.node { - return Some((*sym.as_str()).to_owned()); - } - } - - None - }) - .collect(), + ExprKind::Array(exprs) => path_from_array(exprs), _ => None, } } @@ -258,3 +277,67 @@ fn read_mir_alloc_def_path<'tcx>(cx: &LateContext<'tcx>, alloc: &'tcx Allocation None } } + +fn path_from_array(exprs: &[Expr<'_>]) -> Option> { + exprs + .iter() + .map(|expr| { + if let ExprKind::Lit(lit) = &expr.kind { + if let LitKind::Str(sym, _) = lit.node { + return Some((*sym.as_str()).to_owned()); + } + } + + None + }) + .collect() +} + +// def_path_res will match field names before anything else, but for this we want to match +// inherent functions first. +fn inherent_def_path_res(cx: &LateContext<'_>, segments: &[&str]) -> Option { + def_path_res(cx, segments, None).opt_def_id().map(|def_id| { + if cx.tcx.def_kind(def_id) == DefKind::Field { + let method_name = *segments.last().unwrap(); + cx.tcx + .def_key(def_id) + .parent + .and_then(|parent_idx| { + cx.tcx + .inherent_impls(DefId { + index: parent_idx, + krate: def_id.krate, + }) + .iter() + .find_map(|impl_id| { + cx.tcx.associated_items(*impl_id).find_by_name_and_kind( + cx.tcx, + Ident::from_str(method_name), + AssocKind::Fn, + *impl_id, + ) + }) + }) + .map_or(def_id, |item| item.def_id) + } else { + def_id + } + }) +} + +fn get_lang_item_name(cx: &LateContext<'_>, def_id: DefId) -> Option { + if let Some(lang_item) = cx.tcx.lang_items().items().iter().position(|id| *id == Some(def_id)) { + let lang_items = def_path_res(cx, &["rustc_hir", "lang_items", "LangItem"], Some(Namespace::TypeNS)).def_id(); + let item_name = cx + .tcx + .adt_def(lang_items) + .variants() + .iter() + .nth(lang_item) + .unwrap() + .name; + Some(item_name) + } else { + None + } +} diff --git a/tests/ui-internal/unnecessary_def_path.fixed b/tests/ui-internal/unnecessary_def_path.fixed index 4c050332f..cbbb46523 100644 --- a/tests/ui-internal/unnecessary_def_path.fixed +++ b/tests/ui-internal/unnecessary_def_path.fixed @@ -28,9 +28,9 @@ use rustc_hir::Expr; use rustc_lint::LateContext; use rustc_middle::ty::Ty; -#[allow(unused)] +#[allow(unused, clippy::unnecessary_def_path)] static OPTION: [&str; 3] = ["core", "option", "Option"]; -#[allow(unused)] +#[allow(unused, clippy::unnecessary_def_path)] const RESULT: &[&str] = &["core", "result", "Result"]; fn _f<'tcx>(cx: &LateContext<'tcx>, ty: Ty<'tcx>, did: DefId, expr: &Expr<'_>) { @@ -38,7 +38,7 @@ fn _f<'tcx>(cx: &LateContext<'tcx>, ty: Ty<'tcx>, did: DefId, expr: &Expr<'_>) { let _ = is_type_diagnostic_item(cx, ty, sym::Result); let _ = is_type_diagnostic_item(cx, ty, sym::Result); - #[allow(unused)] + #[allow(unused, clippy::unnecessary_def_path)] let rc_path = &["alloc", "rc", "Rc"]; let _ = is_type_diagnostic_item(cx, ty, sym::Rc); diff --git a/tests/ui-internal/unnecessary_def_path.rs b/tests/ui-internal/unnecessary_def_path.rs index 6506f1f16..f17fed6c6 100644 --- a/tests/ui-internal/unnecessary_def_path.rs +++ b/tests/ui-internal/unnecessary_def_path.rs @@ -28,9 +28,9 @@ use rustc_hir::Expr; use rustc_lint::LateContext; use rustc_middle::ty::Ty; -#[allow(unused)] +#[allow(unused, clippy::unnecessary_def_path)] static OPTION: [&str; 3] = ["core", "option", "Option"]; -#[allow(unused)] +#[allow(unused, clippy::unnecessary_def_path)] const RESULT: &[&str] = &["core", "result", "Result"]; fn _f<'tcx>(cx: &LateContext<'tcx>, ty: Ty<'tcx>, did: DefId, expr: &Expr<'_>) { @@ -38,7 +38,7 @@ fn _f<'tcx>(cx: &LateContext<'tcx>, ty: Ty<'tcx>, did: DefId, expr: &Expr<'_>) { let _ = match_type(cx, ty, RESULT); let _ = match_type(cx, ty, &["core", "result", "Result"]); - #[allow(unused)] + #[allow(unused, clippy::unnecessary_def_path)] let rc_path = &["alloc", "rc", "Rc"]; let _ = clippy_utils::ty::match_type(cx, ty, rc_path); diff --git a/tests/ui-internal/unnecessary_def_path_hardcoded_path.rs b/tests/ui-internal/unnecessary_def_path_hardcoded_path.rs new file mode 100644 index 000000000..b5ff3a542 --- /dev/null +++ b/tests/ui-internal/unnecessary_def_path_hardcoded_path.rs @@ -0,0 +1,16 @@ +#![feature(rustc_private)] +#![allow(unused)] +#![warn(clippy::unnecessary_def_path)] + +extern crate rustc_hir; + +use rustc_hir::LangItem; + +fn main() { + const DEREF_TRAIT: [&str; 4] = ["core", "ops", "deref", "Deref"]; + const DEREF_MUT_TRAIT: [&str; 4] = ["core", "ops", "deref", "DerefMut"]; + const DEREF_TRAIT_METHOD: [&str; 5] = ["core", "ops", "deref", "Deref", "deref"]; + + // Don't lint, not yet a diagnostic or language item + const DEREF_MUT_TRAIT_METHOD: [&str; 5] = ["core", "ops", "deref", "DerefMut", "deref_mut"]; +} diff --git a/tests/ui-internal/unnecessary_def_path_hardcoded_path.stderr b/tests/ui-internal/unnecessary_def_path_hardcoded_path.stderr new file mode 100644 index 000000000..af46d87bf --- /dev/null +++ b/tests/ui-internal/unnecessary_def_path_hardcoded_path.stderr @@ -0,0 +1,27 @@ +error: hardcoded path to a language item + --> $DIR/unnecessary_def_path_hardcoded_path.rs:11:40 + | +LL | const DEREF_MUT_TRAIT: [&str; 4] = ["core", "ops", "deref", "DerefMut"]; + | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ + | + = help: convert all references to use `LangItem::DerefMut` + = note: `-D clippy::unnecessary-def-path` implied by `-D warnings` + +error: hardcoded path to a diagnostic item + --> $DIR/unnecessary_def_path_hardcoded_path.rs:12:43 + | +LL | const DEREF_TRAIT_METHOD: [&str; 5] = ["core", "ops", "deref", "Deref", "deref"]; + | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ + | + = help: convert all references to use `sym::deref_method` + +error: hardcoded path to a diagnostic item + --> $DIR/unnecessary_def_path_hardcoded_path.rs:10:36 + | +LL | const DEREF_TRAIT: [&str; 4] = ["core", "ops", "deref", "Deref"]; + | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ + | + = help: convert all references to use `sym::Deref` + +error: aborting due to 3 previous errors +