hash xor peq

Author: robertbastian

clippy_lints/src/derive.rs

@@ -243,7 +243,7 @@ fn check_hash_peq<'tcx>(
             cx.tcx.for_each_relevant_impl(peq_trait_def_id, ty, |impl_id| {
                 let peq_is_automatically_derived = cx.tcx.has_attr(impl_id, sym::automatically_derived);
 
-                if peq_is_automatically_derived == hash_is_automatically_derived {
+                if !hash_is_automatically_derived || peq_is_automatically_derived {
                     return;
                 }
 
@@ -252,17 +252,11 @@ fn check_hash_peq<'tcx>(
                 // Only care about `impl PartialEq<Foo> for Foo`
                 // For `impl PartialEq<B> for A, input_types is [A, B]
                 if trait_ref.substs.type_at(1) == ty {
-                    let mess = if peq_is_automatically_derived {
-                        "you are implementing `Hash` explicitly but have derived `PartialEq`"
-                    } else {
-                        "you are deriving `Hash` but have implemented `PartialEq` explicitly"
-                    };
-
                     span_lint_and_then(
                         cx,
                         DERIVE_HASH_XOR_EQ,
                         span,
-                        mess,
+                        "you are deriving `Hash` but have implemented `PartialEq` explicitly",
                         |diag| {
                             if let Some(local_def_id) = impl_id.as_local() {
                                 let hir_id = cx.tcx.hir().local_def_id_to_hir_id(local_def_id);

tests/ui/derive_hash_xor_eq.rs

@@ -34,23 +34,4 @@ impl std::hash::Hash for Bah {
     fn hash<H: std::hash::Hasher>(&self, _: &mut H) {}
 }
 
-#[derive(PartialEq)]
-struct Foo2;
-
-trait Hash {}
-
-// We don't want to lint on user-defined traits called `Hash`
-impl Hash for Foo2 {}
-
-mod use_hash {
-    use std::hash::{Hash, Hasher};
-
-    #[derive(PartialEq)]
-    struct Foo3;
-
-    impl Hash for Foo3 {
-        fn hash<H: std::hash::Hasher>(&self, _: &mut H) {}
-    }
-}
-
 fn main() {}

tests/ui/derive_hash_xor_eq.stderr

@@ -25,35 +25,5 @@ LL | impl PartialEq<Baz> for Baz {
    | ^^^^^^^^^^^^^^^^^^^^^^^^^^^
    = note: this error originates in the derive macro `Hash` (in Nightly builds, run with -Z macro-backtrace for more info)
 
-error: you are implementing `Hash` explicitly but have derived `PartialEq`
-  --> $DIR/derive_hash_xor_eq.rs:33:1
-   |
-LL | / impl std::hash::Hash for Bah {
-LL | |     fn hash<H: std::hash::Hasher>(&self, _: &mut H) {}
-LL | | }
-   | |_^
-   |
-note: `PartialEq` implemented here
-  --> $DIR/derive_hash_xor_eq.rs:30:10
-   |
-LL | #[derive(PartialEq)]
-   |          ^^^^^^^^^
-   = note: this error originates in the derive macro `PartialEq` (in Nightly builds, run with -Z macro-backtrace for more info)
-
-error: you are implementing `Hash` explicitly but have derived `PartialEq`
-  --> $DIR/derive_hash_xor_eq.rs:51:5
-   |
-LL | /     impl Hash for Foo3 {
-LL | |         fn hash<H: std::hash::Hasher>(&self, _: &mut H) {}
-LL | |     }
-   | |_____^
-   |
-note: `PartialEq` implemented here
-  --> $DIR/derive_hash_xor_eq.rs:48:14
-   |
-LL |     #[derive(PartialEq)]
-   |              ^^^^^^^^^
-   = note: this error originates in the derive macro `PartialEq` (in Nightly builds, run with -Z macro-backtrace for more info)
-
-error: aborting due to 4 previous errors
+error: aborting due to 2 previous errors