Use UFCS for Ord::cmp

compiler/rustc_builtin_macros/src/deriving/cmp/partial_ord.rs

@@ -100,15 +100,12 @@ pub(crate) fn expand_deriving_partial_ord(
 
 // Special case for the type deriving both `PartialOrd` and `Ord`. Builds:
 // ```
-// Some(self.cmp(other))
+// Some(::core::cmp::Ord::cmp(self, other))
 // ```
 fn cs_partial_cmp_simple(cx: &ExtCtxt<'_>, span: Span, other_expr: Box<ast::Expr>) -> BlockOrExpr {
-    let cmp_expr = cx.expr_method_call(
-        span,
-        cx.expr_self(span),
-        Ident::new(sym::cmp, span),
-        thin_vec![other_expr],
-    );
+    let ord_cmp_path = cx.std_path(&[sym::cmp, sym::Ord, sym::cmp]);
+    let cmp_expr =
+        cx.expr_call_global(span, ord_cmp_path, thin_vec![cx.expr_self(span), other_expr]);
     BlockOrExpr::new_expr(cx.expr_some(span, cmp_expr))
 }
 

tests/ui/derives/deriving-all-codegen.rs

@@ -235,3 +235,21 @@ pub union Union {
 #[derive(Clone)]
 #[derive(Copy)]
 struct FooCloneAndCopy(i32);
+
+#[derive(PartialOrd, Ord)]
+struct FooPartialOrdOrd(i32);
+
+#[derive(Ord, PartialOrd)]
+struct FooOrdPartialOrd(i32);
+
+#[derive(Ord)]
+#[derive(PartialOrd)]
+struct FooOrdBeforePartialOrd(i32);
+
+// FIXME: this case should also have a trivial `PartialOrd` impl.
+#[derive(PartialOrd)]
+#[derive(Ord)]
+struct FooPartialOrdBeforeOrd(i32);
+
+#[derive(PartialOrd, Ord)]
+struct UnitStruct;

tests/ui/derives/deriving-all-codegen.stdout

@@ -72,7 +72,7 @@ impl ::core::cmp::PartialOrd for Empty {
     #[inline]
     fn partial_cmp(&self, other: &Empty)
         -> ::core::option::Option<::core::cmp::Ordering> {
-        ::core::option::Option::Some(self.cmp(other))
+        ::core::option::Option::Some(::core::cmp::Ord::cmp(self, other))
     }
 }
 #[automatically_derived]
@@ -151,7 +151,7 @@ impl ::core::cmp::PartialOrd for Point {
     #[inline]
     fn partial_cmp(&self, other: &Point)
         -> ::core::option::Option<::core::cmp::Ordering> {
-        ::core::option::Option::Some(self.cmp(other))
+        ::core::option::Option::Some(::core::cmp::Ord::cmp(self, other))
     }
 }
 #[automatically_derived]
@@ -235,7 +235,7 @@ impl ::core::cmp::PartialOrd for PackedPoint {
     #[inline]
     fn partial_cmp(&self, other: &PackedPoint)
         -> ::core::option::Option<::core::cmp::Ordering> {
-        ::core::option::Option::Some(self.cmp(other))
+        ::core::option::Option::Some(::core::cmp::Ord::cmp(self, other))
     }
 }
 #[automatically_derived]
@@ -312,7 +312,7 @@ impl ::core::cmp::PartialOrd for TupleSingleField {
     #[inline]
     fn partial_cmp(&self, other: &TupleSingleField)
         -> ::core::option::Option<::core::cmp::Ordering> {
-        ::core::option::Option::Some(self.cmp(other))
+        ::core::option::Option::Some(::core::cmp::Ord::cmp(self, other))
     }
 }
 #[automatically_derived]
@@ -387,7 +387,7 @@ impl ::core::cmp::PartialOrd for SingleField {
     #[inline]
     fn partial_cmp(&self, other: &SingleField)
         -> ::core::option::Option<::core::cmp::Ordering> {
-        ::core::option::Option::Some(self.cmp(other))
+        ::core::option::Option::Some(::core::cmp::Ord::cmp(self, other))
     }
 }
 #[automatically_derived]
@@ -492,7 +492,7 @@ impl ::core::cmp::PartialOrd for Big {
     #[inline]
     fn partial_cmp(&self, other: &Big)
         -> ::core::option::Option<::core::cmp::Ordering> {
-        ::core::option::Option::Some(self.cmp(other))
+        ::core::option::Option::Some(::core::cmp::Ord::cmp(self, other))
     }
 }
 #[automatically_derived]
@@ -716,7 +716,7 @@ impl ::core::cmp::PartialOrd for Unsized {
     #[inline]
     fn partial_cmp(&self, other: &Unsized)
         -> ::core::option::Option<::core::cmp::Ordering> {
-        ::core::option::Option::Some(self.cmp(other))
+        ::core::option::Option::Some(::core::cmp::Ord::cmp(self, other))
     }
 }
 #[automatically_derived]
@@ -1016,7 +1016,7 @@ impl ::core::cmp::PartialOrd for Enum0 {
     #[inline]
     fn partial_cmp(&self, other: &Enum0)
         -> ::core::option::Option<::core::cmp::Ordering> {
-        ::core::option::Option::Some(self.cmp(other))
+        ::core::option::Option::Some(::core::cmp::Ord::cmp(self, other))
     }
 }
 #[automatically_derived]
@@ -1088,7 +1088,7 @@ impl ::core::cmp::PartialOrd for Enum1 {
     #[inline]
     fn partial_cmp(&self, other: &Enum1)
         -> ::core::option::Option<::core::cmp::Ordering> {
-        ::core::option::Option::Some(self.cmp(other))
+        ::core::option::Option::Some(::core::cmp::Ord::cmp(self, other))
     }
 }
 #[automatically_derived]
@@ -1149,7 +1149,7 @@ impl ::core::cmp::PartialOrd for Fieldless1 {
     #[inline]
     fn partial_cmp(&self, other: &Fieldless1)
         -> ::core::option::Option<::core::cmp::Ordering> {
-        ::core::option::Option::Some(self.cmp(other))
+        ::core::option::Option::Some(::core::cmp::Ord::cmp(self, other))
     }
 }
 #[automatically_derived]
@@ -1226,7 +1226,7 @@ impl ::core::cmp::PartialOrd for Fieldless {
     #[inline]
     fn partial_cmp(&self, other: &Fieldless)
         -> ::core::option::Option<::core::cmp::Ordering> {
-        ::core::option::Option::Some(self.cmp(other))
+        ::core::option::Option::Some(::core::cmp::Ord::cmp(self, other))
     }
 }
 #[automatically_derived]
@@ -1338,7 +1338,7 @@ impl ::core::cmp::PartialOrd for Mixed {
     #[inline]
     fn partial_cmp(&self, other: &Mixed)
         -> ::core::option::Option<::core::cmp::Ordering> {
-        ::core::option::Option::Some(self.cmp(other))
+        ::core::option::Option::Some(::core::cmp::Ord::cmp(self, other))
     }
 }
 #[automatically_derived]
@@ -1520,7 +1520,7 @@ impl ::core::cmp::PartialOrd for Fielded {
     #[inline]
     fn partial_cmp(&self, other: &Fielded)
         -> ::core::option::Option<::core::cmp::Ordering> {
-        ::core::option::Option::Some(self.cmp(other))
+        ::core::option::Option::Some(::core::cmp::Ord::cmp(self, other))
     }
 }
 #[automatically_derived]
@@ -1766,3 +1766,89 @@ impl ::core::clone::Clone for FooCloneAndCopy {
         FooCloneAndCopy(::core::clone::Clone::clone(&self.0))
     }
 }
+
+struct FooPartialOrdOrd(i32);
+#[automatically_derived]
+impl ::core::cmp::PartialOrd for FooPartialOrdOrd {
+    #[inline]
+    fn partial_cmp(&self, other: &FooPartialOrdOrd)
+        -> ::core::option::Option<::core::cmp::Ordering> {
+        ::core::option::Option::Some(::core::cmp::Ord::cmp(self, other))
+    }
+}
+#[automatically_derived]
+impl ::core::cmp::Ord for FooPartialOrdOrd {
+    #[inline]
+    fn cmp(&self, other: &FooPartialOrdOrd) -> ::core::cmp::Ordering {
+        ::core::cmp::Ord::cmp(&self.0, &other.0)
+    }
+}
+
+struct FooOrdPartialOrd(i32);
+#[automatically_derived]
+impl ::core::cmp::Ord for FooOrdPartialOrd {
+    #[inline]
+    fn cmp(&self, other: &FooOrdPartialOrd) -> ::core::cmp::Ordering {
+        ::core::cmp::Ord::cmp(&self.0, &other.0)
+    }
+}
+#[automatically_derived]
+impl ::core::cmp::PartialOrd for FooOrdPartialOrd {
+    #[inline]
+    fn partial_cmp(&self, other: &FooOrdPartialOrd)
+        -> ::core::option::Option<::core::cmp::Ordering> {
+        ::core::option::Option::Some(::core::cmp::Ord::cmp(self, other))
+    }
+}
+
+struct FooOrdBeforePartialOrd(i32);
+#[automatically_derived]
+impl ::core::cmp::PartialOrd for FooOrdBeforePartialOrd {
+    #[inline]
+    fn partial_cmp(&self, other: &FooOrdBeforePartialOrd)
+        -> ::core::option::Option<::core::cmp::Ordering> {
+        ::core::option::Option::Some(::core::cmp::Ord::cmp(self, other))
+    }
+}
+#[automatically_derived]
+impl ::core::cmp::Ord for FooOrdBeforePartialOrd {
+    #[inline]
+    fn cmp(&self, other: &FooOrdBeforePartialOrd) -> ::core::cmp::Ordering {
+        ::core::cmp::Ord::cmp(&self.0, &other.0)
+    }
+}
+
+// FIXME: this case should also have a trivial `PartialOrd` impl.
+struct FooPartialOrdBeforeOrd(i32);
+#[automatically_derived]
+impl ::core::cmp::Ord for FooPartialOrdBeforeOrd {
+    #[inline]
+    fn cmp(&self, other: &FooPartialOrdBeforeOrd) -> ::core::cmp::Ordering {
+        ::core::cmp::Ord::cmp(&self.0, &other.0)
+    }
+}
+#[automatically_derived]
+impl ::core::cmp::PartialOrd for FooPartialOrdBeforeOrd {
+    #[inline]
+    fn partial_cmp(&self, other: &FooPartialOrdBeforeOrd)
+        -> ::core::option::Option<::core::cmp::Ordering> {
+        ::core::cmp::PartialOrd::partial_cmp(&self.0, &other.0)
+    }
+}
+
+struct UnitStruct;
+#[automatically_derived]
+impl ::core::cmp::PartialOrd for UnitStruct {
+    #[inline]
+    fn partial_cmp(&self, other: &UnitStruct)
+        -> ::core::option::Option<::core::cmp::Ordering> {
+        ::core::option::Option::Some(::core::cmp::Ord::cmp(self, other))
+    }
+}
+#[automatically_derived]
+impl ::core::cmp::Ord for UnitStruct {
+    #[inline]
+    fn cmp(&self, other: &UnitStruct) -> ::core::cmp::Ordering {
+        ::core::cmp::Ordering::Equal
+    }
+}

tests/ui/stats/macro-stats.stderr

@@ -10,7 +10,7 @@ macro-stats #[derive(Default)]                    2         16        8.0
 macro-stats #[derive(Eq)]                         1         11       11.0        312      312.0
 macro-stats #[derive(Debug)]                      1          8        8.0        277      277.0
 macro-stats #[derive(PartialEq)]                  1          9        9.0        267      267.0
-macro-stats #[derive(PartialOrd)]                 1          8        8.0        235      235.0
+macro-stats #[derive(PartialOrd)]                 1          8        8.0        254      254.0
 macro-stats #[derive(Copy)]                       1          2        2.0         61       61.0
 macro-stats p!                                    1          3        3.0         32       32.0
 macro-stats trait_impl_tys!                       1          2        2.0         28       28.0