Auto merge of #10752 - Alexendoo:default-units-macros, r=giraffate

Ignore expressions from macros in `default_constructed_unit_structs`

changelog: none, should be the same release as the lint itself

Author: bors

clippy_lints/src/default_constructed_unit_structs.rs

@@ -1,4 +1,4 @@
-use clippy_utils::{diagnostics::span_lint_and_sugg, is_from_proc_macro, match_def_path, paths};
+use clippy_utils::{diagnostics::span_lint_and_sugg, match_def_path, paths};
 use hir::{def::Res, ExprKind};
 use rustc_errors::Applicability;
 use rustc_hir as hir;
@@ -55,7 +55,8 @@ impl LateLintPass<'_> for DefaultConstructedUnitStructs {
             if let ty::Adt(def, ..) = cx.typeck_results().expr_ty(expr).kind();
             if def.is_struct();
             if let var @ ty::VariantDef { ctor: Some((hir::def::CtorKind::Const, _)), .. } = def.non_enum_variant();
-            if !var.is_field_list_non_exhaustive() && !is_from_proc_macro(cx, expr);
+            if !var.is_field_list_non_exhaustive();
+            if !expr.span.from_expansion() && !qpath.span().from_expansion();
             then {
                 span_lint_and_sugg(
                     cx,

tests/ui/default_constructed_unit_structs.fixed

@@ -105,6 +105,7 @@ fn main() {
     // should lint
     let _ = PhantomData::<usize>;
     let _: PhantomData<i32> = PhantomData;
+    let _: PhantomData<i32> = std::marker::PhantomData;
     let _ = UnitStruct;
 
     // should not lint
@@ -116,4 +117,21 @@ fn main() {
     let _ = EmptyStruct::default();
     let _ = FakeDefault::default();
     let _ = <FakeDefault as Default>::default();
+
+    macro_rules! in_macro {
+        ($i:ident) => {{
+            let _ = UnitStruct::default();
+            let _ = $i::default();
+        }};
+    }
+
+    in_macro!(UnitStruct);
+
+    macro_rules! struct_from_macro {
+        () => {
+            UnitStruct
+        };
+    }
+
+    let _ = <struct_from_macro!()>::default();
 }

tests/ui/default_constructed_unit_structs.rs

@@ -105,6 +105,7 @@ fn main() {
     // should lint
     let _ = PhantomData::<usize>::default();
     let _: PhantomData<i32> = PhantomData::default();
+    let _: PhantomData<i32> = std::marker::PhantomData::default();
     let _ = UnitStruct::default();
 
     // should not lint
@@ -116,4 +117,21 @@ fn main() {
     let _ = EmptyStruct::default();
     let _ = FakeDefault::default();
     let _ = <FakeDefault as Default>::default();
+
+    macro_rules! in_macro {
+        ($i:ident) => {{
+            let _ = UnitStruct::default();
+            let _ = $i::default();
+        }};
+    }
+
+    in_macro!(UnitStruct);
+
+    macro_rules! struct_from_macro {
+        () => {
+            UnitStruct
+        };
+    }
+
+    let _ = <struct_from_macro!()>::default();
 }

tests/ui/default_constructed_unit_structs.stderr

@@ -25,10 +25,16 @@ LL |     let _: PhantomData<i32> = PhantomData::default();
    |                                          ^^^^^^^^^^^ help: remove this call to `default`
 
 error: use of `default` to create a unit struct
-  --> $DIR/default_constructed_unit_structs.rs:108:23
+  --> $DIR/default_constructed_unit_structs.rs:108:55
+   |
+LL |     let _: PhantomData<i32> = std::marker::PhantomData::default();
+   |                                                       ^^^^^^^^^^^ help: remove this call to `default`
+
+error: use of `default` to create a unit struct
+  --> $DIR/default_constructed_unit_structs.rs:109:23
    |
 LL |     let _ = UnitStruct::default();
    |                       ^^^^^^^^^^^ help: remove this call to `default`
 
-error: aborting due to 5 previous errors
+error: aborting due to 6 previous errors