Replace str path utils with new PathLookup type

Author: Alexendoo

CONTRIBUTING.md

@@ -77,7 +77,7 @@ debugging to find the actual problem behind the issue.
 
 [`T-middle`] issues can be more involved and require verifying types. The [`ty`] module contains a
 lot of methods that are useful, though one of the most useful would be `expr_ty` (gives the type of
-an AST expression). `match_def_path()` in Clippy's `utils` module can also be useful.
+an AST expression).
 
 [`good-first-issue`]: https://github.com/rust-lang/rust-clippy/labels/good-first-issue
 [`S-inactive-closed`]: https://github.com/rust-lang/rust-clippy/pulls?q=is%3Aclosed+label%3AS-inactive-closed

book/src/development/common_tools_writing_lints.md

@@ -86,7 +86,7 @@ arguments have to be checked separately.
 
 ```rust
 use clippy_utils::ty::{is_type_diagnostic_item, is_type_lang_item};
-use clippy_utils::{paths, match_def_path};
+use clippy_utils::paths;
 use rustc_span::symbol::sym;
 use rustc_hir::LangItem;
 
@@ -108,7 +108,7 @@ impl LateLintPass<'_> for MyStructLint {
 
         // 3. Using the type path
         // This method should be avoided if possible
-        if match_def_path(cx, def_id, &paths::RESULT) {
+        if paths::RESULT.matches_ty(cx, ty) {
             // The type is a `core::result::Result`
         }
     }

book/src/development/trait_checking.md

@@ -73,22 +73,24 @@ impl LateLintPass<'_> for CheckDropTraitLint {
 ## Using Type Path
 
 If neither diagnostic item nor a language item is available, we can use
-[`clippy_utils::paths`][paths] with the `match_trait_method` to determine trait
-implementation.
+[`clippy_utils::paths`][paths] to determine get a trait's `DefId`.
 
 > **Note**: This approach should be avoided if possible, the best thing to do would be to make a PR to [`rust-lang/rust`][rust] adding a diagnostic item.
 
-Below, we check if the given `expr` implements the `Iterator`'s trait method `cloned` :
+Below, we check if the given `expr` implements [`core::iter::Step`](https://doc.rust-lang.org/std/iter/trait.Step.html):
 
 ```rust
-use clippy_utils::{match_trait_method, paths};
+use clippy_utils::{implements_trait, paths};
 use rustc_hir::Expr;
 use rustc_lint::{LateContext, LateLintPass};
 
-impl LateLintPass<'_> for CheckTokioAsyncReadExtTrait {
+impl LateLintPass<'_> for CheckIterStep {
     fn check_expr(&mut self, cx: &LateContext<'_>, expr: &Expr<'_>) {
-        if match_trait_method(cx, expr, &paths::CORE_ITER_CLONED) {
-            println!("`expr` implements `CORE_ITER_CLONED` trait!");
+        let ty = cx.typeck_results().expr_ty(expr);
+        if let Some(trait_def_id) = paths::ITER_STEP.first(cx)
+            && implements_trait(cx, ty, trait_def_id, &[])
+        {
+            println!("`expr` implements the `core::iter::Step` trait!");
         }
     }
 }

clippy_config/src/types.rs

@@ -1,10 +1,10 @@
 use rustc_data_structures::fx::FxHashMap;
 use rustc_errors::{Applicability, Diag};
 use rustc_hir::PrimTy;
-use rustc_hir::def::{DefKind, Res};
+use rustc_hir::def::DefKind;
 use rustc_hir::def_id::DefIdMap;
 use rustc_middle::ty::TyCtxt;
-use rustc_span::Span;
+use rustc_span::{Span, Symbol};
 use serde::de::{self, Deserializer, Visitor};
 use serde::{Deserialize, Serialize, ser};
 use std::collections::HashMap;
@@ -145,57 +145,41 @@ pub fn create_disallowed_map<const REPLACEMENT_ALLOWED: bool>(
         FxHashMap::default();
     for disallowed_path in disallowed_paths {
         let path = disallowed_path.path();
-        let mut resolutions = clippy_utils::def_path_res(tcx, &path.split("::").collect::<Vec<_>>());
-
-        let mut found_def_id = None;
-        let mut found_prim_ty = false;
-        resolutions.retain(|res| match res {
-            Res::Def(def_kind, def_id) => {
-                found_def_id = Some(*def_id);
-                def_kind_predicate(*def_kind)
-            },
-            Res::PrimTy(_) => {
-                found_prim_ty = true;
-                allow_prim_tys
-            },
-            _ => false,
-        });
+        let sym_path: Vec<Symbol> = path.split("::").map(Symbol::intern).collect();
+        let mut resolutions = clippy_utils::lookup_path(tcx, &sym_path);
 
-        if resolutions.is_empty() {
-            let span = disallowed_path.span();
+        let found_def_id = resolutions.first().copied();
+        resolutions.retain(|&def_id| def_kind_predicate(tcx.def_kind(def_id)));
 
-            if let Some(def_id) = found_def_id {
-                tcx.sess.dcx().span_warn(
-                    span,
-                    format!(
-                        "expected a {predicate_description}, found {} {}",
-                        tcx.def_descr_article(def_id),
-                        tcx.def_descr(def_id)
-                    ),
-                );
+        let (prim_ty, found_prim_ty) = if let &[name] = sym_path.as_slice()
+            && let Some(prim) = PrimTy::from_name(name)
+        {
+            (allow_prim_tys.then_some(prim), true)
+        } else {
+            (None, false)
+        };
+
+        if resolutions.is_empty() && prim_ty.is_none() && !disallowed_path.allow_invalid {
+            let message = if let Some(def_id) = found_def_id {
+                let (article, description) = tcx.article_and_description(def_id);
+                format!("expected a {predicate_description}, found {article} {description}")
             } else if found_prim_ty {
-                tcx.sess.dcx().span_warn(
-                    span,
-                    format!("expected a {predicate_description}, found a primitive type",),
-                );
-            } else if !disallowed_path.allow_invalid {
-                tcx.sess.dcx().span_warn(
-                    span,
-                    format!("`{path}` does not refer to an existing {predicate_description}"),
-                );
-            }
+                format!("expected a {predicate_description}, found a primitive type")
+            } else {
+                format!("`{path}` does not refer to a reachable {predicate_description}")
+            };
+            tcx.sess
+                .dcx()
+                .struct_span_warn(disallowed_path.span(), message)
+                .with_help("add `allow-invalid = true` to the entry to suppress this warning")
+                .emit();
         }
 
-        for res in resolutions {
-            match res {
-                Res::Def(_, def_id) => {
-                    def_ids.insert(def_id, (path, disallowed_path));
-                },
-                Res::PrimTy(ty) => {
-                    prim_tys.insert(ty, (path, disallowed_path));
-                },
-                _ => unreachable!(),
-            }
+        for def_id in resolutions {
+            def_ids.insert(def_id, (path, disallowed_path));
+        }
+        if let Some(ty) = prim_ty {
+            prim_tys.insert(ty, (path, disallowed_path));
         }
     }
 

clippy_lints/src/await_holding_invalid.rs

@@ -1,7 +1,7 @@
 use clippy_config::Conf;
 use clippy_config::types::{DisallowedPathWithoutReplacement, create_disallowed_map};
 use clippy_utils::diagnostics::span_lint_and_then;
-use clippy_utils::{match_def_path, paths};
+use clippy_utils::paths;
 use rustc_hir as hir;
 use rustc_hir::def_id::{DefId, DefIdMap};
 use rustc_lint::{LateContext, LateLintPass};
@@ -275,12 +275,10 @@ fn emit_invalid_type(
 }
 
 fn is_mutex_guard(cx: &LateContext<'_>, def_id: DefId) -> bool {
-    cx.tcx.is_diagnostic_item(sym::MutexGuard, def_id)
-        || cx.tcx.is_diagnostic_item(sym::RwLockReadGuard, def_id)
-        || cx.tcx.is_diagnostic_item(sym::RwLockWriteGuard, def_id)
-        || match_def_path(cx, def_id, &paths::PARKING_LOT_MUTEX_GUARD)
-        || match_def_path(cx, def_id, &paths::PARKING_LOT_RWLOCK_READ_GUARD)
-        || match_def_path(cx, def_id, &paths::PARKING_LOT_RWLOCK_WRITE_GUARD)
+    match cx.tcx.get_diagnostic_name(def_id) {
+        Some(name) => matches!(name, sym::MutexGuard | sym::RwLockReadGuard | sym::RwLockWriteGuard),
+        None => paths::PARKING_LOT_GUARDS.iter().any(|guard| guard.matches(cx, def_id)),
+    }
 }
 
 fn is_refcell_ref(cx: &LateContext<'_>, def_id: DefId) -> bool {

clippy_lints/src/casts/manual_dangling_ptr.rs

@@ -1,7 +1,7 @@
 use clippy_utils::diagnostics::span_lint_and_sugg;
 use clippy_utils::source::SpanRangeExt;
 use clippy_utils::ty::is_normalizable;
-use clippy_utils::{expr_or_init, match_def_path, path_def_id, paths, std_or_core};
+use clippy_utils::{expr_or_init, path_def_id, paths, std_or_core};
 use rustc_ast::LitKind;
 use rustc_errors::Applicability;
 use rustc_hir::{Expr, ExprKind, GenericArg, Mutability, QPath, Ty, TyKind};
@@ -55,7 +55,7 @@ fn is_expr_const_aligned(cx: &LateContext<'_>, expr: &Expr<'_>, to: &Ty<'_>) ->
 fn is_align_of_call(cx: &LateContext<'_>, fun: &Expr<'_>, to: &Ty<'_>) -> bool {
     if let ExprKind::Path(QPath::Resolved(_, path)) = fun.kind
         && let Some(fun_id) = path_def_id(cx, fun)
-        && match_def_path(cx, fun_id, &paths::ALIGN_OF)
+        && paths::ALIGN_OF.matches(cx, fun_id)
         && let Some(args) = path.segments.last().and_then(|seg| seg.args)
         && let [GenericArg::Type(generic_ty)] = args.args
     {

clippy_lints/src/derive.rs

@@ -2,7 +2,7 @@ use std::ops::ControlFlow;
 
 use clippy_utils::diagnostics::{span_lint_and_note, span_lint_and_then, span_lint_hir_and_then};
 use clippy_utils::ty::{implements_trait, implements_trait_with_env, is_copy};
-use clippy_utils::{has_non_exhaustive_attr, is_lint_allowed, match_def_path, paths};
+use clippy_utils::{has_non_exhaustive_attr, is_lint_allowed, paths};
 use rustc_errors::Applicability;
 use rustc_hir::def_id::DefId;
 use rustc_hir::intravisit::{FnKind, Visitor, walk_expr, walk_fn, walk_item};
@@ -377,7 +377,7 @@ fn check_unsafe_derive_deserialize<'tcx>(
     }
 
     if let Some(trait_def_id) = trait_ref.trait_def_id()
-        && match_def_path(cx, trait_def_id, &paths::SERDE_DESERIALIZE)
+        && paths::SERDE_DESERIALIZE.matches(cx, trait_def_id)
         && let ty::Adt(def, _) = ty.kind()
         && let Some(local_def_id) = def.did().as_local()
         && let adt_hir_id = cx.tcx.local_def_id_to_hir_id(local_def_id)

clippy_lints/src/functions/mod.rs

@@ -9,7 +9,7 @@ mod too_many_arguments;
 mod too_many_lines;
 
 use clippy_config::Conf;
-use clippy_utils::def_path_def_ids;
+use clippy_utils::lookup_path_str;
 use clippy_utils::msrvs::Msrv;
 use rustc_hir as hir;
 use rustc_hir::intravisit;
@@ -469,7 +469,7 @@ impl Functions {
             trait_ids: conf
                 .allow_renamed_params_for
                 .iter()
-                .flat_map(|p| def_path_def_ids(tcx, &p.split("::").collect::<Vec<_>>()))
+                .flat_map(|p| lookup_path_str(tcx, p))
                 .collect(),
             msrv: conf.msrv,
         }

clippy_lints/src/let_underscore.rs

@@ -1,5 +1,5 @@
 use clippy_utils::diagnostics::span_lint_and_then;
-use clippy_utils::ty::{implements_trait, is_must_use_ty, match_type};
+use clippy_utils::ty::{implements_trait, is_must_use_ty};
 use clippy_utils::{is_from_proc_macro, is_must_use_func_call, paths};
 use rustc_hir::{LetStmt, LocalSource, PatKind};
 use rustc_lint::{LateContext, LateLintPass};
@@ -129,12 +129,6 @@ declare_clippy_lint! {
 
 declare_lint_pass!(LetUnderscore => [LET_UNDERSCORE_MUST_USE, LET_UNDERSCORE_LOCK, LET_UNDERSCORE_FUTURE, LET_UNDERSCORE_UNTYPED]);
 
-const SYNC_GUARD_PATHS: [&[&str]; 3] = [
-    &paths::PARKING_LOT_MUTEX_GUARD,
-    &paths::PARKING_LOT_RWLOCK_READ_GUARD,
-    &paths::PARKING_LOT_RWLOCK_WRITE_GUARD,
-];
-
 impl<'tcx> LateLintPass<'tcx> for LetUnderscore {
     fn check_local(&mut self, cx: &LateContext<'tcx>, local: &LetStmt<'tcx>) {
         if matches!(local.source, LocalSource::Normal)
@@ -144,7 +138,9 @@ impl<'tcx> LateLintPass<'tcx> for LetUnderscore {
         {
             let init_ty = cx.typeck_results().expr_ty(init);
             let contains_sync_guard = init_ty.walk().any(|inner| match inner.unpack() {
-                GenericArgKind::Type(inner_ty) => SYNC_GUARD_PATHS.iter().any(|path| match_type(cx, inner_ty, path)),
+                GenericArgKind::Type(inner_ty) => inner_ty
+                    .ty_adt_def()
+                    .is_some_and(|adt| paths::PARKING_LOT_GUARDS.iter().any(|path| path.matches(cx, adt.did()))),
                 GenericArgKind::Lifetime(_) | GenericArgKind::Const(_) => false,
             });
             if contains_sync_guard {

clippy_lints/src/manual_option_as_slice.rs

@@ -1,7 +1,7 @@
 use clippy_config::Conf;
 use clippy_utils::diagnostics::{span_lint, span_lint_and_sugg};
 use clippy_utils::msrvs::Msrv;
-use clippy_utils::{is_none_arm, msrvs, peel_hir_expr_refs, sym};
+use clippy_utils::{is_none_arm, msrvs, paths, peel_hir_expr_refs, sym};
 use rustc_errors::Applicability;
 use rustc_hir::def::{DefKind, Res};
 use rustc_hir::{Arm, Expr, ExprKind, LangItem, Pat, PatKind, QPath, is_range_literal};
@@ -220,5 +220,5 @@ fn is_empty_slice(cx: &LateContext<'_>, expr: &Expr<'_>) -> bool {
 }
 
 fn is_slice_from_ref(cx: &LateContext<'_>, expr: &Expr<'_>) -> bool {
-    clippy_utils::is_expr_path_def_path(cx, expr, &["core", "slice", "raw", "from_ref"])
+    paths::SLICE_FROM_REF.matches_path(cx, expr)
 }

clippy_lints/src/methods/io_other_error.rs

@@ -1,5 +1,6 @@
 use clippy_utils::diagnostics::span_lint_and_then;
 use clippy_utils::msrvs::{self, Msrv};
+use clippy_utils::{expr_or_init, paths};
 use rustc_errors::Applicability;
 use rustc_hir::{Expr, ExprKind, QPath};
 use rustc_lint::LateContext;
@@ -8,13 +9,9 @@ pub(super) fn check(cx: &LateContext<'_>, expr: &Expr<'_>, path: &Expr<'_>, args
     if let [error_kind, error] = args
         && !expr.span.from_expansion()
         && !error_kind.span.from_expansion()
-        && clippy_utils::is_expr_path_def_path(cx, path, &clippy_utils::paths::IO_ERROR_NEW)
-        && clippy_utils::is_expr_path_def_path(
-            cx,
-            clippy_utils::expr_or_init(cx, error_kind),
-            &clippy_utils::paths::IO_ERRORKIND_OTHER,
-        )
         && let ExprKind::Path(QPath::TypeRelative(_, new_segment)) = path.kind
+        && paths::IO_ERROR_NEW.matches_path(cx, path)
+        && paths::IO_ERRORKIND_OTHER.matches_path(cx, expr_or_init(cx, error_kind))
         && msrv.meets(cx, msrvs::IO_ERROR_OTHER)
     {
         span_lint_and_then(

clippy_lints/src/methods/manual_saturating_arithmetic.rs

@@ -1,9 +1,10 @@
 use clippy_utils::diagnostics::span_lint_and_sugg;
 use clippy_utils::source::snippet_with_applicability;
-use clippy_utils::{match_def_path, path_def_id};
+use clippy_utils::{path_res, sym};
 use rustc_ast::ast;
 use rustc_errors::Applicability;
 use rustc_hir as hir;
+use rustc_hir::def::Res;
 use rustc_lint::LateContext;
 use rustc_middle::ty::layout::LayoutOf;
 
@@ -79,16 +80,15 @@ fn is_min_or_max(cx: &LateContext<'_>, expr: &hir::Expr<'_>) -> Option<MinMax> {
     }
 
     let ty = cx.typeck_results().expr_ty(expr);
-    let ty_str = ty.to_string();
 
-    // `std::T::MAX` `std::T::MIN` constants
-    if let Some(id) = path_def_id(cx, expr) {
-        if match_def_path(cx, id, &["core", &ty_str, "MAX"]) {
-            return Some(MinMax::Max);
-        }
-
-        if match_def_path(cx, id, &["core", &ty_str, "MIN"]) {
-            return Some(MinMax::Min);
+    // `T::MAX` and `T::MIN` constants
+    if let hir::ExprKind::Path(hir::QPath::TypeRelative(base, seg)) = expr.kind
+        && let Res::PrimTy(_) = path_res(cx, base)
+    {
+        match seg.ident.name {
+            sym::MAX => return Some(MinMax::Max),
+            sym::MIN => return Some(MinMax::Min),
+            _ => {},
         }
     }
 

clippy_lints/src/methods/needless_character_iteration.rs

@@ -7,9 +7,8 @@ use rustc_span::Span;
 use super::NEEDLESS_CHARACTER_ITERATION;
 use super::utils::get_last_chain_binding_hir_id;
 use clippy_utils::diagnostics::span_lint_and_sugg;
-use clippy_utils::paths::CHAR_IS_ASCII;
 use clippy_utils::source::SpanRangeExt;
-use clippy_utils::{match_def_path, path_to_local_id, peel_blocks, sym};
+use clippy_utils::{is_path_diagnostic_item, path_to_local_id, peel_blocks, sym};
 
 fn peels_expr_ref<'a, 'tcx>(mut expr: &'a Expr<'tcx>) -> &'a Expr<'tcx> {
     while let ExprKind::AddrOf(_, _, e) = expr.kind {
@@ -76,9 +75,7 @@ fn handle_expr(
             // If we have `!is_ascii`, then only `.any()` should warn. And if the condition is
             // `is_ascii`, then only `.all()` should warn.
             if revert != is_all
-                && let ExprKind::Path(path) = fn_path.kind
-                && let Some(fn_def_id) = cx.qpath_res(&path, fn_path.hir_id).opt_def_id()
-                && match_def_path(cx, fn_def_id, &CHAR_IS_ASCII)
+                && is_path_diagnostic_item(cx, fn_path, sym::char_is_ascii)
                 && path_to_local_id(peels_expr_ref(arg), first_param)
                 && let Some(snippet) = before_chars.get_source_text(cx)
             {