Don't lint redundant_field_names across macro boundaries

Author: Alexendoo

clippy_lints/src/redundant_field_names.rs

@@ -59,24 +59,22 @@ impl EarlyLintPass for RedundantFieldNames {
         }
         if let ExprKind::Struct(ref se) = expr.kind {
             for field in &se.fields {
-                if field.is_shorthand {
-                    continue;
-                }
-                if let ExprKind::Path(None, path) = &field.expr.kind {
-                    if path.segments.len() == 1
-                        && path.segments[0].ident == field.ident
-                        && path.segments[0].args.is_none()
-                    {
-                        span_lint_and_sugg(
-                            cx,
-                            REDUNDANT_FIELD_NAMES,
-                            field.span,
-                            "redundant field names in struct initialization",
-                            "replace it with",
-                            field.ident.to_string(),
-                            Applicability::MachineApplicable,
-                        );
-                    }
+                if !field.is_shorthand
+                    && let ExprKind::Path(None, path) = &field.expr.kind
+                    && let [segment] = path.segments.as_slice()
+                    && segment.args.is_none()
+                    && segment.ident == field.ident
+                    && field.span.eq_ctxt(field.ident.span)
+                {
+                    span_lint_and_sugg(
+                        cx,
+                        REDUNDANT_FIELD_NAMES,
+                        field.span,
+                        "redundant field names in struct initialization",
+                        "replace it with",
+                        field.ident.to_string(),
+                        Applicability::MachineApplicable,
+                    );
                 }
             }
         }

tests/ui/redundant_field_names.fixed

@@ -20,7 +20,7 @@ struct Person {
 }
 
 pub struct S {
-    v: String,
+    v: usize,
 }
 
 fn main() {
@@ -59,11 +59,22 @@ fn main() {
     let _ = RangeToInclusive { end };
 
     external! {
-        let v = String::new();
+        let v = 1;
         let _ = S {
             v: v
         };
     }
+
+    let v = 2;
+    macro_rules! internal {
+        ($i:ident) => {
+            let _ = S { v };
+            let _ = S { $i: v };
+            let _ = S { v: $i };
+            let _ = S { $i: $i };
+        };
+    }
+    internal!(v);
 }
 
 fn issue_3476() {

tests/ui/redundant_field_names.rs

@@ -20,7 +20,7 @@ struct Person {
 }
 
 pub struct S {
-    v: String,
+    v: usize,
 }
 
 fn main() {
@@ -59,11 +59,22 @@ fn main() {
     let _ = RangeToInclusive { end: end };
 
     external! {
-        let v = String::new();
+        let v = 1;
         let _ = S {
             v: v
         };
     }
+
+    let v = 2;
+    macro_rules! internal {
+        ($i:ident) => {
+            let _ = S { v: v };
+            let _ = S { $i: v };
+            let _ = S { v: $i };
+            let _ = S { $i: $i };
+        };
+    }
+    internal!(v);
 }
 
 fn issue_3476() {

tests/ui/redundant_field_names.stderr

@@ -44,10 +44,21 @@ LL |     let _ = RangeToInclusive { end: end };
    |                                ^^^^^^^^ help: replace it with: `end`
 
 error: redundant field names in struct initialization
-  --> tests/ui/redundant_field_names.rs:88:25
+  --> tests/ui/redundant_field_names.rs:71:25
+   |
+LL |             let _ = S { v: v };
+   |                         ^^^^ help: replace it with: `v`
+...
+LL |     internal!(v);
+   |     ------------ in this macro invocation
+   |
+   = note: this error originates in the macro `internal` (in Nightly builds, run with -Z macro-backtrace for more info)
+
+error: redundant field names in struct initialization
+  --> tests/ui/redundant_field_names.rs:99:25
    |
 LL |     let _ = RangeFrom { start: start };
    |                         ^^^^^^^^^^^^ help: replace it with: `start`
 
-error: aborting due to 8 previous errors
+error: aborting due to 9 previous errors