Rollup merge of #5870 - ebroto:5789_allow_unsafe_derive_deserialize, …

…r=flip1995

enable #[allow(clippy::unsafe_derive_deserialize)]

Before this change this lint could not be allowed as the code we are checking is automatically generated.

changelog: Enable using the `allow` attribute on top of an ADT linted by [`unsafe_derive_deserialize`].

Fixes: #5789

clippy_lints/src/derive.rs

@@ -1,7 +1,7 @@
 use crate::utils::paths;
 use crate::utils::{
-    get_trait_def_id, is_automatically_derived, is_copy, match_path, span_lint_and_help, span_lint_and_note,
-    span_lint_and_then,
+    get_trait_def_id, is_allowed, is_automatically_derived, is_copy, match_path, span_lint_and_help,
+    span_lint_and_note, span_lint_and_then,
 };
 use if_chain::if_chain;
 use rustc_hir::def_id::DefId;
@@ -354,7 +354,9 @@ fn check_unsafe_derive_deserialize<'tcx>(
     if_chain! {
         if match_path(&trait_ref.path, &paths::SERDE_DESERIALIZE);
         if let ty::Adt(def, _) = ty.kind;
-        if def.did.is_local();
+        if let Some(local_def_id) = def.did.as_local();
+        let adt_hir_id = cx.tcx.hir().as_local_hir_id(local_def_id);
+        if !is_allowed(cx, UNSAFE_DERIVE_DESERIALIZE, adt_hir_id);
         if cx.tcx.inherent_impls(def.did)
             .iter()
             .map(|imp_did| item_from_def_id(cx, *imp_did))

tests/ui/unsafe_derive_deserialize.rs

@@ -57,4 +57,14 @@ impl E {
 #[derive(Deserialize)]
 pub struct F {}
 
+// Check that we honor the `allow` attribute on the ADT
+#[allow(clippy::unsafe_derive_deserialize)]
+#[derive(Deserialize)]
+pub struct G {}
+impl G {
+    pub fn unsafe_block(&self) {
+        unsafe {}
+    }
+}
+
 fn main() {}