Add diagnostic items for Clippy

compiler/rustc_span/src/symbol.rs

@@ -642,6 +642,7 @@ symbols! {
         cfi_encoding,
         char,
         char_is_ascii,
+        char_to_digit,
         child_id,
         child_kill,
         client,
@@ -1217,6 +1218,8 @@ symbols! {
         intrinsics,
         intrinsics_unaligned_volatile_load,
         intrinsics_unaligned_volatile_store,
+        io_error_new,
+        io_errorkind,
         io_stderr,
         io_stdout,
         irrefutable_let_patterns,
@@ -1306,6 +1309,7 @@ symbols! {
         m68k_target_feature,
         macro_at_most_once_rep,
         macro_attributes_in_derive_output,
+        macro_concat,
         macro_escape,
         macro_export,
         macro_lifetime_matcher,
@@ -1340,6 +1344,7 @@ symbols! {
         maybe_uninit,
         maybe_uninit_uninit,
         maybe_uninit_zeroed,
+        mem_align_of,
         mem_discriminant,
         mem_drop,
         mem_forget,
@@ -1707,6 +1712,7 @@ symbols! {
         question_mark,
         quote,
         range_inclusive_new,
+        range_step,
         raw_dylib,
         raw_dylib_elf,
         raw_eq,
@@ -2023,6 +2029,7 @@ symbols! {
         slice,
         slice_from_raw_parts,
         slice_from_raw_parts_mut,
+        slice_from_ref,
         slice_get_unchecked,
         slice_into_vec,
         slice_iter,

library/core/src/char/methods.rs

@@ -395,6 +395,7 @@ impl char {
     /// ```
     #[stable(feature = "rust1", since = "1.0.0")]
     #[rustc_const_stable(feature = "const_char_convert", since = "1.67.0")]
+    #[rustc_diagnostic_item = "char_to_digit"]
     #[must_use = "this returns the result of the operation, \
                   without modifying the original"]
     #[inline]

library/core/src/iter/range.rs

@@ -20,6 +20,7 @@ unsafe_impl_trusted_step![AsciiChar char i8 i16 i32 i64 i128 isize u8 u16 u32 u6
 ///
 /// The *successor* operation moves towards values that compare greater.
 /// The *predecessor* operation moves towards values that compare lesser.
+#[rustc_diagnostic_item = "range_step"]
 #[unstable(feature = "step_trait", issue = "42168")]
 pub trait Step: Clone + PartialOrd + Sized {
     /// Returns the bounds on the number of *successor* steps required to get from `start` to `end`

library/core/src/macros/mod.rs

@@ -1192,6 +1192,7 @@ pub(crate) mod builtin {
     /// ```
     #[stable(feature = "rust1", since = "1.0.0")]
     #[rustc_builtin_macro]
+    #[rustc_diagnostic_item = "macro_concat"]
     #[macro_export]
     macro_rules! concat {
         ($($e:expr),* $(,)?) => {{ /* compiler built-in */ }};

library/core/src/mem/mod.rs

@@ -481,6 +481,7 @@ pub fn min_align_of_val<T: ?Sized>(val: &T) -> usize {
 #[stable(feature = "rust1", since = "1.0.0")]
 #[rustc_promotable]
 #[rustc_const_stable(feature = "const_align_of", since = "1.24.0")]
+#[rustc_diagnostic_item = "mem_align_of"]
 pub const fn align_of<T>() -> usize {
     intrinsics::align_of::<T>()
 }

library/core/src/slice/raw.rs

@@ -198,6 +198,7 @@ pub const unsafe fn from_raw_parts_mut<'a, T>(data: *mut T, len: usize) -> &'a m
 /// Converts a reference to T into a slice of length 1 (without copying).
 #[stable(feature = "from_ref", since = "1.28.0")]
 #[rustc_const_stable(feature = "const_slice_from_ref_shared", since = "1.63.0")]
+#[rustc_diagnostic_item = "slice_from_ref"]
 #[must_use]
 pub const fn from_ref<T>(s: &T) -> &[T] {
     array::from_ref(s)

library/std/src/io/error.rs

@@ -219,6 +219,7 @@ struct Custom {
 /// the recognized error kinds and fail in those cases.
 #[derive(Clone, Copy, Debug, Eq, Hash, Ord, PartialEq, PartialOrd)]
 #[stable(feature = "rust1", since = "1.0.0")]
+#[cfg_attr(not(test), rustc_diagnostic_item = "io_errorkind")]
 #[allow(deprecated)]
 #[non_exhaustive]
 pub enum ErrorKind {
@@ -562,6 +563,7 @@ impl Error {
     /// let eof_error = Error::from(ErrorKind::UnexpectedEof);
     /// ```
     #[stable(feature = "rust1", since = "1.0.0")]
+    #[cfg_attr(not(test), rustc_diagnostic_item = "io_error_new")]
     #[inline(never)]
     pub fn new<E>(kind: ErrorKind, error: E) -> Error
     where

src/tools/clippy/clippy_lints/src/casts/manual_dangling_ptr.rs

@@ -1,6 +1,6 @@
 use clippy_utils::diagnostics::span_lint_and_sugg;
 use clippy_utils::source::SpanRangeExt;
-use clippy_utils::{expr_or_init, path_def_id, paths, std_or_core};
+use clippy_utils::{expr_or_init, is_path_diagnostic_item, std_or_core, sym};
 use rustc_ast::LitKind;
 use rustc_errors::Applicability;
 use rustc_hir::{Expr, ExprKind, GenericArg, Mutability, QPath, Ty, TyKind};
@@ -53,8 +53,7 @@ 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)
-        && paths::ALIGN_OF.matches(cx, fun_id)
+        && is_path_diagnostic_item(cx, fun, sym::mem_align_of)
         && let Some(args) = path.segments.last().and_then(|seg| seg.args)
         && let [GenericArg::Type(generic_ty)] = args.args
     {

src/tools/clippy/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, paths, peel_hir_expr_refs, sym};
+use clippy_utils::{is_none_arm, msrvs, 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 {
-    paths::SLICE_FROM_REF.matches_path(cx, expr)
+    clippy_utils::is_path_diagnostic_item(cx, expr, sym::slice_from_ref)
 }

src/tools/clippy/clippy_lints/src/methods/io_other_error.rs

@@ -1,6 +1,6 @@
 use clippy_utils::diagnostics::span_lint_and_then;
 use clippy_utils::msrvs::{self, Msrv};
-use clippy_utils::{expr_or_init, paths};
+use clippy_utils::{expr_or_init, is_path_diagnostic_item, sym};
 use rustc_errors::Applicability;
 use rustc_hir::{Expr, ExprKind, QPath};
 use rustc_lint::LateContext;
@@ -10,8 +10,11 @@ pub(super) fn check(cx: &LateContext<'_>, expr: &Expr<'_>, path: &Expr<'_>, args
         && !expr.span.from_expansion()
         && !error_kind.span.from_expansion()
         && let ExprKind::Path(QPath::TypeRelative(_, new_segment)) = path.kind
-        && paths::IO_ERROR_NEW.matches_path(cx, path)
-        && paths::IO_ERRORKIND_OTHER_CTOR.matches_path(cx, expr_or_init(cx, error_kind))
+        && is_path_diagnostic_item(cx, path, sym::io_error_new)
+        && let ExprKind::Path(QPath::Resolved(_, init_path)) = &expr_or_init(cx, error_kind).kind
+        && let [.., error_kind_ty, error_kind_variant] = init_path.segments
+        && cx.tcx.is_diagnostic_item(sym::io_errorkind, error_kind_ty.res.def_id())
+        && error_kind_variant.ident.name == sym::Other
         && msrv.meets(cx, msrvs::IO_ERROR_OTHER)
     {
         span_lint_and_then(

src/tools/clippy/clippy_lints/src/single_range_in_vec_init.rs

@@ -3,7 +3,7 @@ use clippy_utils::higher::VecArgs;
 use clippy_utils::macros::root_macro_call_first_node;
 use clippy_utils::source::SpanRangeExt;
 use clippy_utils::ty::implements_trait;
-use clippy_utils::{is_no_std_crate, paths};
+use clippy_utils::{is_no_std_crate, sym};
 use rustc_ast::{LitIntType, LitKind, UintTy};
 use rustc_errors::Applicability;
 use rustc_hir::{Expr, ExprKind, LangItem, QPath, StructTailExpr};
@@ -100,7 +100,7 @@ impl LateLintPass<'_> for SingleRangeInVecInit {
             && let Some(start_snippet) = start.span.get_source_text(cx)
             && let Some(end_snippet) = end.span.get_source_text(cx)
         {
-            let should_emit_every_value = if let Some(step_def_id) = paths::ITER_STEP.only(cx)
+            let should_emit_every_value = if let Some(step_def_id) = cx.tcx.get_diagnostic_item(sym::range_step)
                 && implements_trait(cx, ty, step_def_id, &[])
             {
                 true

src/tools/clippy/clippy_lints/src/to_digit_is_some.rs

@@ -2,7 +2,7 @@ use clippy_config::Conf;
 use clippy_utils::diagnostics::span_lint_and_sugg;
 use clippy_utils::msrvs::{self, Msrv};
 use clippy_utils::source::snippet_with_applicability;
-use clippy_utils::{is_in_const_context, paths, sym};
+use clippy_utils::{is_in_const_context, is_path_diagnostic_item, sym};
 use rustc_errors::Applicability;
 use rustc_hir as hir;
 use rustc_lint::{LateContext, LateLintPass};
@@ -62,7 +62,7 @@ impl<'tcx> LateLintPass<'tcx> for ToDigitIsSome {
                     }
                 },
                 hir::ExprKind::Call(to_digits_call, [char_arg, radix_arg]) => {
-                    if paths::CHAR_TO_DIGIT.matches_path(cx, to_digits_call) {
+                    if is_path_diagnostic_item(cx, to_digits_call, sym::char_to_digit) {
                         Some((false, char_arg, radix_arg))
                     } else {
                         None

src/tools/clippy/clippy_lints/src/useless_concat.rs

@@ -1,8 +1,7 @@
 use clippy_utils::diagnostics::span_lint_and_sugg;
 use clippy_utils::macros::macro_backtrace;
-use clippy_utils::paths::CONCAT;
 use clippy_utils::source::snippet_opt;
-use clippy_utils::tokenize_with_text;
+use clippy_utils::{sym, tokenize_with_text};
 use rustc_ast::LitKind;
 use rustc_errors::Applicability;
 use rustc_hir::{Expr, ExprKind};
@@ -43,7 +42,7 @@ impl LateLintPass<'_> for UselessConcat {
             // Get the direct parent of the expression.
             && let Some(macro_call) = macro_backtrace(expr.span).next()
             // Check if the `concat` macro from the `core` library.
-            && CONCAT.matches(cx, macro_call.def_id)
+            && cx.tcx.is_diagnostic_item(sym::macro_concat, macro_call.def_id)
             // We get the original code to parse it.
             && let Some(original_code) = snippet_opt(cx, macro_call.span)
             // This check allows us to ensure that the code snippet:

src/tools/clippy/clippy_utils/src/paths.rs

@@ -126,15 +126,6 @@ path_macros! {
     macro_path: PathNS::Macro,
 }
 
-// Paths in `core`/`alloc`/`std`. This should be avoided and cleaned up by adding diagnostic items.
-pub static ALIGN_OF: PathLookup = value_path!(core::mem::align_of);
-pub static CHAR_TO_DIGIT: PathLookup = value_path!(char::to_digit);
-pub static CONCAT: PathLookup = macro_path!(core::concat);
-pub static IO_ERROR_NEW: PathLookup = value_path!(std::io::Error::new);
-pub static IO_ERRORKIND_OTHER_CTOR: PathLookup = value_path!(std::io::ErrorKind::Other);
-pub static ITER_STEP: PathLookup = type_path!(core::iter::Step);
-pub static SLICE_FROM_REF: PathLookup = value_path!(core::slice::from_ref);
-
 // Paths in external crates
 pub static FUTURES_IO_ASYNCREADEXT: PathLookup = type_path!(futures_util::AsyncReadExt);
 pub static FUTURES_IO_ASYNCWRITEEXT: PathLookup = type_path!(futures_util::AsyncWriteExt);