Emit unnecessary_def_path in source order.

Author: Jarcho

clippy_lints/src/utils/internal_lints/unnecessary_def_path.rs

@@ -3,7 +3,7 @@ use clippy_utils::source::snippet_with_applicability;
 use clippy_utils::{def_path_def_ids, is_lint_allowed, match_any_def_paths, peel_hir_expr_refs};
 use if_chain::if_chain;
 use rustc_ast::ast::LitKind;
-use rustc_data_structures::fx::FxHashSet;
+use rustc_data_structures::fx::{FxHashSet, FxIndexSet};
 use rustc_errors::Applicability;
 use rustc_hir as hir;
 use rustc_hir::def::{DefKind, Res};
@@ -44,7 +44,7 @@ impl_lint_pass!(UnnecessaryDefPath => [UNNECESSARY_DEF_PATH]);
 
 #[derive(Default)]
 pub struct UnnecessaryDefPath {
-    array_def_ids: FxHashSet<(DefId, Span)>,
+    array_def_ids: FxIndexSet<(DefId, Span)>,
     linted_def_ids: FxHashSet<DefId>,
 }
 

tests/ui-internal/unnecessary_def_path_hardcoded_path.stderr

@@ -1,19 +1,11 @@
-error: hardcoded path to a diagnostic item
-  --> $DIR/unnecessary_def_path_hardcoded_path.rs:12:43
-   |
-LL |     const DEREF_TRAIT_METHOD: [&str; 5] = ["core", "ops", "deref", "Deref", "deref"];
-   |                                           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
-   |
-   = help: convert all references to use `sym::deref_method`
-   = note: `-D clippy::unnecessary-def-path` implied by `-D warnings`
-
 error: hardcoded path to a diagnostic item
   --> $DIR/unnecessary_def_path_hardcoded_path.rs:10:36
    |
 LL |     const DEREF_TRAIT: [&str; 4] = ["core", "ops", "deref", "Deref"];
    |                                    ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
    |
    = help: convert all references to use `sym::Deref`
+   = note: `-D clippy::unnecessary-def-path` implied by `-D warnings`
 
 error: hardcoded path to a language item
   --> $DIR/unnecessary_def_path_hardcoded_path.rs:11:40
@@ -23,5 +15,13 @@ LL |     const DEREF_MUT_TRAIT: [&str; 4] = ["core", "ops", "deref", "DerefMut"]
    |
    = help: convert all references to use `LangItem::DerefMut`
 
+error: hardcoded path to a diagnostic item
+  --> $DIR/unnecessary_def_path_hardcoded_path.rs:12:43
+   |
+LL |     const DEREF_TRAIT_METHOD: [&str; 5] = ["core", "ops", "deref", "Deref", "deref"];
+   |                                           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+   |
+   = help: convert all references to use `sym::deref_method`
+
 error: aborting due to 3 previous errors