Merge pull request #3007 from mikerite/issue3000

Fix #3000

clippy_lints/src/lib.rs

@@ -178,6 +178,7 @@ mod reexport {
 
 pub fn register_pre_expansion_lints(session: &rustc::session::Session, store: &mut rustc::lint::LintStore) {
     store.register_pre_expansion_pass(Some(session), box write::Pass);
+    store.register_pre_expansion_pass(Some(session), box redundant_field_names::RedundantFieldNames);
 }
 
 #[cfg_attr(rustfmt, rustfmt_skip)]
@@ -390,7 +391,6 @@ pub fn register_plugins(reg: &mut rustc_plugin::Registry<'_>) {
     reg.register_late_lint_pass(box double_comparison::DoubleComparisonPass);
     reg.register_late_lint_pass(box question_mark::QuestionMarkPass);
     reg.register_late_lint_pass(box suspicious_trait_impl::SuspiciousImpl);
-    reg.register_late_lint_pass(box redundant_field_names::RedundantFieldNames);
     reg.register_early_lint_pass(box multiple_crate_versions::Pass);
     reg.register_late_lint_pass(box map_unit_fn::Pass);
     reg.register_late_lint_pass(box infallible_destructuring_match::Pass);

clippy_lints/src/redundant_field_names.rs

@@ -1,7 +1,7 @@
 use rustc::lint::*;
 use rustc::{declare_lint, lint_array};
-use rustc::hir::*;
-use crate::utils::{in_macro, match_var, span_lint_and_sugg};
+use syntax::ast::*;
+use crate::utils::{span_lint_and_sugg};
 
 /// **What it does:** Checks for fields in struct literals where shorthands
 /// could be used.
@@ -35,28 +35,24 @@ impl LintPass for RedundantFieldNames {
     }
 }
 
-impl<'a, 'tcx> LateLintPass<'a, 'tcx> for RedundantFieldNames {
-    fn check_expr(&mut self, cx: &LateContext<'a, 'tcx>, expr: &'tcx Expr) {
-        // Ignore all macros including range expressions.
-        // They can have redundant field names when expanded.
-        // e.g. range expression `start..end` is desugared to `Range { start: start, end: end }`
-        if in_macro(expr.span) {
-            return;
-        }
-
+impl EarlyLintPass for RedundantFieldNames {
+    fn check_expr(&mut self, cx: &EarlyContext<'_>, expr: &Expr) {
         if let ExprKind::Struct(_, ref fields, _) = expr.node {
             for field in fields {
-                let name = field.ident.name;
-
-                if match_var(&field.expr, name) && !field.is_shorthand {
-                    span_lint_and_sugg (
-                        cx,
-                        REDUNDANT_FIELD_NAMES,
-                        field.span,
-                        "redundant field names in struct initialization",
-                        "replace it with",
-                        name.to_string()
-                    );
+                if field.is_shorthand {
+                    continue;
+                }
+                if let ExprKind::Path(None, path) = &field.expr.node {
+                    if path.segments.len() == 1 && path.segments[0].ident == field.ident {
+                        span_lint_and_sugg (
+                            cx,
+                            REDUNDANT_FIELD_NAMES,
+                            field.span,
+                            "redundant field names in struct initialization",
+                            "replace it with",
+                            field.ident.to_string()
+                        );
+                    }
                 }
             }
         }

tests/ui/redundant_field_names.stderr

@@ -12,36 +12,6 @@ error: redundant field names in struct initialization
 35 |         age: age,
    |         ^^^^^^^^ help: replace it with: `age`
 
-error: redundant field names in struct initialization
-  --> $DIR/redundant_field_names.rs:45:13
-   |
-45 |     let _ = start..;
-   |             ^^^^^ help: replace it with: `start`
-
-error: redundant field names in struct initialization
-  --> $DIR/redundant_field_names.rs:46:15
-   |
-46 |     let _ = ..end;
-   |               ^^^ help: replace it with: `end`
-
-error: redundant field names in struct initialization
-  --> $DIR/redundant_field_names.rs:47:13
-   |
-47 |     let _ = start..end;
-   |             ^^^^^ help: replace it with: `start`
-
-error: redundant field names in struct initialization
-  --> $DIR/redundant_field_names.rs:47:20
-   |
-47 |     let _ = start..end;
-   |                    ^^^ help: replace it with: `end`
-
-error: redundant field names in struct initialization
-  --> $DIR/redundant_field_names.rs:49:16
-   |
-49 |     let _ = ..=end;
-   |                ^^^ help: replace it with: `end`
-
 error: redundant field names in struct initialization
   --> $DIR/redundant_field_names.rs:53:25
    |
@@ -72,5 +42,5 @@ error: redundant field names in struct initialization
 57 |     let _ = RangeToInclusive { end: end };
    |                                ^^^^^^^^ help: replace it with: `end`
 
-error: aborting due to 12 previous errors
+error: aborting due to 7 previous errors
 

tests/ui/trivially_copy_pass_by_ref.rs

@@ -1,4 +1,4 @@
-#![allow(many_single_char_names, blacklisted_name)]
+#![allow(many_single_char_names, blacklisted_name, redundant_field_names)]
 
 #[derive(Copy, Clone)]
 struct Foo(u32);