[Clippy] Swap float_equality_without_abs to use diagnostic items instead of paths

Author: GnomedDev

compiler/rustc_span/src/symbol.rs

@@ -838,6 +838,7 @@ symbols! {
         f16_nan,
         f16c_target_feature,
         f32,
+        f32_epsilon,
         f32_legacy_const_digits,
         f32_legacy_const_epsilon,
         f32_legacy_const_infinity,
@@ -854,6 +855,7 @@ symbols! {
         f32_legacy_const_radix,
         f32_nan,
         f64,
+        f64_epsilon,
         f64_legacy_const_digits,
         f64_legacy_const_epsilon,
         f64_legacy_const_infinity,

library/core/src/num/f32.rs

@@ -415,6 +415,7 @@ impl f32 {
     /// [Machine epsilon]: https://en.wikipedia.org/wiki/Machine_epsilon
     /// [`MANTISSA_DIGITS`]: f32::MANTISSA_DIGITS
     #[stable(feature = "assoc_int_consts", since = "1.43.0")]
+    #[cfg_attr(not(test), rustc_diagnostic_item = "f32_epsilon")]
     pub const EPSILON: f32 = 1.19209290e-07_f32;
 
     /// Smallest finite `f32` value.

library/core/src/num/f64.rs

@@ -414,6 +414,7 @@ impl f64 {
     /// [Machine epsilon]: https://en.wikipedia.org/wiki/Machine_epsilon
     /// [`MANTISSA_DIGITS`]: f64::MANTISSA_DIGITS
     #[stable(feature = "assoc_int_consts", since = "1.43.0")]
+    #[cfg_attr(not(test), rustc_diagnostic_item = "f64_epsilon")]
     pub const EPSILON: f64 = 2.2204460492503131e-16_f64;
 
     /// Smallest finite `f64` value.

src/tools/clippy/clippy_lints/src/operators/float_equality_without_abs.rs

@@ -1,12 +1,12 @@
 use clippy_utils::diagnostics::span_lint_and_then;
-use clippy_utils::{match_def_path, paths, sugg};
+use clippy_utils::sugg;
 use rustc_ast::util::parser::AssocOp;
 use rustc_errors::Applicability;
 use rustc_hir::def::{DefKind, Res};
 use rustc_hir::{BinOpKind, Expr, ExprKind};
 use rustc_lint::LateContext;
 use rustc_middle::ty;
-use rustc_span::source_map::Spanned;
+use rustc_span::{sym, source_map::Spanned};
 
 use super::FLOAT_EQUALITY_WITHOUT_ABS;
 
@@ -36,7 +36,7 @@ pub(crate) fn check<'tcx>(
         // right hand side matches either f32::EPSILON or f64::EPSILON
         && let ExprKind::Path(ref epsilon_path) = rhs.kind
         && let Res::Def(DefKind::AssocConst, def_id) = cx.qpath_res(epsilon_path, rhs.hir_id)
-        && (match_def_path(cx, def_id, &paths::F32_EPSILON) || match_def_path(cx, def_id, &paths::F64_EPSILON))
+        && ([sym::f32_epsilon, sym::f64_epsilon].into_iter().any(|sym| cx.tcx.is_diagnostic_item(sym, def_id)))
 
         // values of the subtractions on the left hand side are of the type float
         && let t_val_l = cx.typeck_results().expr_ty(val_l)

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

@@ -14,8 +14,6 @@ pub const APPLICABILITY_VALUES: [[&str; 3]; 4] = [
 pub const DIAG: [&str; 2] = ["rustc_errors", "Diag"];
 pub const EARLY_CONTEXT: [&str; 2] = ["rustc_lint", "EarlyContext"];
 pub const EARLY_LINT_PASS: [&str; 3] = ["rustc_lint", "passes", "EarlyLintPass"];
-pub const F32_EPSILON: [&str; 4] = ["core", "f32", "<impl f32>", "EPSILON"];
-pub const F64_EPSILON: [&str; 4] = ["core", "f64", "<impl f64>", "EPSILON"];
 pub const FILE_OPTIONS: [&str; 4] = ["std", "fs", "File", "options"];
 #[expect(clippy::invalid_paths)] // internal lints do not know about all external crates
 pub const FUTURES_IO_ASYNCREADEXT: [&str; 3] = ["futures_util", "io", "AsyncReadExt"];