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

compiler/rustc_span/src/symbol.rs

@@ -1876,11 +1876,14 @@ symbols! {
         store,
         str,
         str_chars,
+        str_ends_with,
         str_from_utf8,
         str_from_utf8_mut,
         str_from_utf8_unchecked,
         str_from_utf8_unchecked_mut,
+        str_len,
         str_split_whitespace,
+        str_starts_with,
         str_trim,
         str_trim_end,
         str_trim_start,

library/core/src/str/mod.rs

@@ -134,6 +134,7 @@ impl str {
     /// ```
     #[stable(feature = "rust1", since = "1.0.0")]
     #[rustc_const_stable(feature = "const_str_len", since = "1.39.0")]
+    #[cfg_attr(not(test), rustc_diagnostic_item = "str_len")]
     #[must_use]
     #[inline]
     pub const fn len(&self) -> usize {
@@ -1157,6 +1158,7 @@ impl str {
     /// assert!(bananas.starts_with(&['a', 'b', 'c', 'd']));
     /// ```
     #[stable(feature = "rust1", since = "1.0.0")]
+    #[cfg_attr(not(test), rustc_diagnostic_item = "str_starts_with")]
     pub fn starts_with<P: Pattern>(&self, pat: P) -> bool {
         pat.is_prefix_of(self)
     }
@@ -1181,6 +1183,7 @@ impl str {
     /// assert!(!bananas.ends_with("nana"));
     /// ```
     #[stable(feature = "rust1", since = "1.0.0")]
+    #[cfg_attr(not(test), rustc_diagnostic_item = "str_ends_with")]
     pub fn ends_with<P: Pattern>(&self, pat: P) -> bool
     where
         for<'a> P::Searcher<'a>: ReverseSearcher<'a>,

src/tools/clippy/clippy_lints/src/manual_strip.rs

@@ -4,7 +4,7 @@ use clippy_utils::consts::{ConstEvalCtxt, Constant};
 use clippy_utils::diagnostics::span_lint_and_then;
 use clippy_utils::source::snippet;
 use clippy_utils::usage::mutated_variables;
-use clippy_utils::{eq_expr_value, higher, match_def_path, paths};
+use clippy_utils::{eq_expr_value, higher};
 use rustc_ast::ast::LitKind;
 use rustc_errors::Applicability;
 use rustc_hir::def::Res;
@@ -14,7 +14,7 @@ use rustc_lint::{LateContext, LateLintPass};
 use rustc_middle::ty;
 use rustc_session::impl_lint_pass;
 use rustc_span::source_map::Spanned;
-use rustc_span::Span;
+use rustc_span::{sym, Span};
 use std::iter;
 
 declare_clippy_lint! {
@@ -76,9 +76,9 @@ impl<'tcx> LateLintPass<'tcx> for ManualStrip {
             && self.msrv.meets(msrvs::STR_STRIP_PREFIX)
             && let Some(method_def_id) = cx.typeck_results().type_dependent_def_id(cond.hir_id)
         {
-            let strip_kind = if match_def_path(cx, method_def_id, &paths::STR_STARTS_WITH) {
+            let strip_kind = if cx.tcx.is_diagnostic_item(sym::str_starts_with, method_def_id) {
                 StripKind::Prefix
-            } else if match_def_path(cx, method_def_id, &paths::STR_ENDS_WITH) {
+            } else if cx.tcx.is_diagnostic_item(sym::str_ends_with, method_def_id) {
                 StripKind::Suffix
             } else {
                 return;
@@ -137,7 +137,7 @@ impl<'tcx> LateLintPass<'tcx> for ManualStrip {
 fn len_arg<'tcx>(cx: &LateContext<'tcx>, expr: &'tcx Expr<'_>) -> Option<&'tcx Expr<'tcx>> {
     if let ExprKind::MethodCall(_, arg, [], _) = expr.kind
         && let Some(method_def_id) = cx.typeck_results().type_dependent_def_id(expr.hir_id)
-        && match_def_path(cx, method_def_id, &paths::STR_LEN)
+        && cx.tcx.is_diagnostic_item(sym::str_len, method_def_id)
     {
         Some(arg)
     } else {

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

@@ -52,9 +52,6 @@ pub const SERDE_DE_VISITOR: [&str; 3] = ["serde", "de", "Visitor"];
 pub const STD_IO_SEEK_FROM_CURRENT: [&str; 4] = ["std", "io", "SeekFrom", "Current"];
 pub const STD_IO_SEEKFROM_START: [&str; 4] = ["std", "io", "SeekFrom", "Start"];
 pub const STRING_NEW: [&str; 4] = ["alloc", "string", "String", "new"];
-pub const STR_ENDS_WITH: [&str; 4] = ["core", "str", "<impl str>", "ends_with"];
-pub const STR_LEN: [&str; 4] = ["core", "str", "<impl str>", "len"];
-pub const STR_STARTS_WITH: [&str; 4] = ["core", "str", "<impl str>", "starts_with"];
 pub const SYMBOL: [&str; 3] = ["rustc_span", "symbol", "Symbol"];
 pub const SYMBOL_AS_STR: [&str; 4] = ["rustc_span", "symbol", "Symbol", "as_str"];
 pub const SYMBOL_INTERN: [&str; 4] = ["rustc_span", "symbol", "Symbol", "intern"];