Auto merge of rust-lang#11191 - Alexendoo:redundant-type-annotations-…

…ice, r=llogiq

redundant_type_annotations: only pass certain def kinds to type_of

Fixes rust-lang#11190
Fixes rust-lang#113516

Also adds an `is_lint_allowed` check to skip the lint when it's not needed

changelog: none

src/tools/clippy/clippy_lints/src/redundant_type_annotations.rs

@@ -1,6 +1,8 @@
 use clippy_utils::diagnostics::span_lint;
+use clippy_utils::is_lint_allowed;
 use rustc_ast::LitKind;
 use rustc_hir as hir;
+use rustc_hir::def::DefKind;
 use rustc_lint::{LateContext, LateLintPass};
 use rustc_middle::ty::Ty;
 use rustc_session::{declare_lint_pass, declare_tool_lint};
@@ -45,8 +47,8 @@ fn is_same_type<'tcx>(cx: &LateContext<'tcx>, ty_resolved_path: hir::def::Res, f
         return primty.name() == func_return_type_sym;
     }
 
-    // type annotation is any other non generic type
-    if let hir::def::Res::Def(_, defid) = ty_resolved_path
+    // type annotation is a non generic type
+    if let hir::def::Res::Def(DefKind::Struct | DefKind::Union | DefKind::Enum, defid) = ty_resolved_path
         && let Some(annotation_ty) = cx.tcx.type_of(defid).no_bound_vars()
     {
         return annotation_ty == func_return_type;
@@ -130,8 +132,9 @@ fn extract_primty(ty_kind: &hir::TyKind<'_>) -> Option<hir::PrimTy> {
 
 impl LateLintPass<'_> for RedundantTypeAnnotations {
     fn check_local<'tcx>(&mut self, cx: &LateContext<'tcx>, local: &'tcx rustc_hir::Local<'tcx>) {
-        // type annotation part
-        if !local.span.from_expansion()
+        if !is_lint_allowed(cx, REDUNDANT_TYPE_ANNOTATIONS, local.hir_id)
+            // type annotation part
+            && !local.span.from_expansion()
             && let Some(ty) = &local.ty
 
             // initialization part

src/tools/clippy/tests/ui/redundant_type_annotations.rs

@@ -6,8 +6,8 @@ struct Cake<T> {
     _data: T,
 }
 
-fn make_something<T: Default>() -> T {
-    T::default()
+fn make_something<T>() -> T {
+    unimplemented!()
 }
 
 fn make_cake<T: Default>() -> Cake<T> {
@@ -117,7 +117,15 @@ fn test_non_locals() {
     let _closure_arg = |x: u32| x;
 }
 
-fn test_complex_types() {
+trait Trait {
+    type AssocTy;
+}
+
+impl Trait for () {
+    type AssocTy = String;
+}
+
+fn test_complex_types<T>() {
     // Shouldn't be lint, since the literal will be i32 otherwise
     let _u8: u8 = 128;
 
@@ -135,6 +143,10 @@ fn test_complex_types() {
 
     // Shouldn't be lint
     let _array: [u32; 2] = [8, 9];
+
+    let ty_param: T = make_something();
+
+    let assoc_ty: <() as Trait>::AssocTy = String::new();
 }
 
 fn test_functions() {
@@ -173,4 +185,6 @@ fn test_simple_types() {
     let _var: bool = false;
 }
 
+fn issue11190() {}
+
 fn main() {}

src/tools/clippy/tests/ui/redundant_type_annotations.stderr

@@ -19,85 +19,85 @@ LL |         let v: &Slice = self.return_a_ref_to_struct();
    |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
 error: redundant type annotation
-  --> $DIR/redundant_type_annotations.rs:143:5
+  --> $DIR/redundant_type_annotations.rs:155:5
    |
 LL |     let _return: String = return_a_string();
    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
 error: redundant type annotation
-  --> $DIR/redundant_type_annotations.rs:145:5
+  --> $DIR/redundant_type_annotations.rs:157:5
    |
 LL |     let _return: Pie = return_a_struct();
    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
 error: redundant type annotation
-  --> $DIR/redundant_type_annotations.rs:147:5
+  --> $DIR/redundant_type_annotations.rs:159:5
    |
 LL |     let _return: Pizza = return_an_enum();
    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
 error: redundant type annotation
-  --> $DIR/redundant_type_annotations.rs:149:5
+  --> $DIR/redundant_type_annotations.rs:161:5
    |
 LL |     let _return: u32 = return_an_int();
    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
 error: redundant type annotation
-  --> $DIR/redundant_type_annotations.rs:151:5
+  --> $DIR/redundant_type_annotations.rs:163:5
    |
 LL |     let _return: String = String::new();
    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
 error: redundant type annotation
-  --> $DIR/redundant_type_annotations.rs:153:5
+  --> $DIR/redundant_type_annotations.rs:165:5
    |
 LL |     let new_pie: Pie = Pie::new();
    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
 error: redundant type annotation
-  --> $DIR/redundant_type_annotations.rs:155:5
+  --> $DIR/redundant_type_annotations.rs:167:5
    |
 LL |     let _return: u32 = new_pie.return_an_int();
    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
 error: redundant type annotation
-  --> $DIR/redundant_type_annotations.rs:157:5
+  --> $DIR/redundant_type_annotations.rs:169:5
    |
 LL |     let _return: u32 = Pie::associated_return_an_int();
    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
 error: redundant type annotation
-  --> $DIR/redundant_type_annotations.rs:159:5
+  --> $DIR/redundant_type_annotations.rs:171:5
    |
 LL |     let _return: String = Pie::associated_return_a_string();
    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
 error: redundant type annotation
-  --> $DIR/redundant_type_annotations.rs:165:5
+  --> $DIR/redundant_type_annotations.rs:177:5
    |
 LL |     let _var: u32 = u32::MAX;
    |     ^^^^^^^^^^^^^^^^^^^^^^^^^
 
 error: redundant type annotation
-  --> $DIR/redundant_type_annotations.rs:167:5
+  --> $DIR/redundant_type_annotations.rs:179:5
    |
 LL |     let _var: u32 = 5_u32;
    |     ^^^^^^^^^^^^^^^^^^^^^^
 
 error: redundant type annotation
-  --> $DIR/redundant_type_annotations.rs:169:5
+  --> $DIR/redundant_type_annotations.rs:181:5
    |
 LL |     let _var: &str = "test";
    |     ^^^^^^^^^^^^^^^^^^^^^^^^
 
 error: redundant type annotation
-  --> $DIR/redundant_type_annotations.rs:171:5
+  --> $DIR/redundant_type_annotations.rs:183:5
    |
 LL |     let _var: &[u8] = b"test";
    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^
 
 error: redundant type annotation
-  --> $DIR/redundant_type_annotations.rs:173:5
+  --> $DIR/redundant_type_annotations.rs:185:5
    |
 LL |     let _var: bool = false;
    |     ^^^^^^^^^^^^^^^^^^^^^^^