Avoid looking regex crate up multiple times

Author: GnomedDev

clippy_lints/src/regex.rs

@@ -3,7 +3,7 @@ use std::fmt::Display;
 use clippy_utils::consts::{ConstEvalCtxt, Constant};
 use clippy_utils::diagnostics::{span_lint, span_lint_and_help};
 use clippy_utils::source::SpanRangeExt;
-use clippy_utils::{def_path_def_ids, path_def_id, paths};
+use clippy_utils::{def_path_res_in_crates, find_crates, path_def_id, paths};
 use rustc_ast::ast::{LitKind, StrStyle};
 use rustc_hir::def_id::DefIdMap;
 use rustc_hir::{BorrowKind, Expr, ExprKind};
@@ -75,11 +75,14 @@ impl<'tcx> LateLintPass<'tcx> for Regex {
         // We don't use `match_def_path` here because that relies on matching the exact path, which changed
         // between regex 1.8 and 1.9
         //
-        // `def_path_def_ids` will resolve through re-exports but is relatively heavy, so we only perform
-        // the operation once and store the results
+        // `def_path_res_in_crates` will resolve through re-exports but is relatively heavy, so we only
+        // perform the operation once and store the results
+        let regex_crates = find_crates(cx.tcx, sym!(regex));
         let mut resolve = |path, kind| {
-            for id in def_path_def_ids(cx.tcx, path) {
-                self.definitions.insert(id, kind);
+            for res in def_path_res_in_crates(cx.tcx, regex_crates.clone(), path) {
+                if let Some(id) = res.opt_def_id() {
+                    self.definitions.insert(id, kind);
+                }
             }
         };
 

clippy_utils/src/paths.rs

@@ -67,12 +67,12 @@ pub const PATH_TO_PATH_BUF: [&str; 4] = ["std", "path", "Path", "to_path_buf"];
 #[cfg_attr(not(unix), allow(clippy::invalid_paths))]
 pub const PERMISSIONS_FROM_MODE: [&str; 6] = ["std", "os", "unix", "fs", "PermissionsExt", "from_mode"];
 pub const PUSH_STR: [&str; 4] = ["alloc", "string", "String", "push_str"];
-pub const REGEX_BUILDER_NEW: [&str; 3] = ["regex", "RegexBuilder", "new"];
-pub const REGEX_BYTES_BUILDER_NEW: [&str; 4] = ["regex", "bytes", "RegexBuilder", "new"];
-pub const REGEX_BYTES_NEW: [&str; 4] = ["regex", "bytes", "Regex", "new"];
-pub const REGEX_BYTES_SET_NEW: [&str; 4] = ["regex", "bytes", "RegexSet", "new"];
-pub const REGEX_NEW: [&str; 3] = ["regex", "Regex", "new"];
-pub const REGEX_SET_NEW: [&str; 3] = ["regex", "RegexSet", "new"];
+pub const REGEX_BUILDER_NEW: [&str; 2] = ["RegexBuilder", "new"];
+pub const REGEX_BYTES_BUILDER_NEW: [&str; 3] = ["bytes", "RegexBuilder", "new"];
+pub const REGEX_BYTES_NEW: [&str; 3] = ["bytes", "Regex", "new"];
+pub const REGEX_BYTES_SET_NEW: [&str; 3] = ["bytes", "RegexSet", "new"];
+pub const REGEX_NEW: [&str; 2] = ["Regex", "new"];
+pub const REGEX_SET_NEW: [&str; 2] = ["RegexSet", "new"];
 pub const SERDE_DESERIALIZE: [&str; 3] = ["serde", "de", "Deserialize"];
 pub const SERDE_DE_VISITOR: [&str; 3] = ["serde", "de", "Visitor"];
 pub const SLICE_INTO_VEC: [&str; 4] = ["alloc", "slice", "<impl [T]>", "into_vec"];