Add ~const bounds trait bounds when using derive_const

diff --git a/compiler/rustc_builtin_macros/src/deriving/debug.rs b/compiler/rustc_builtin_macros/src/deriving/debug.rs
index 74e2597830e7ed27a1fd0fae301052628d9ffb9e..e8a353b1c8fcc61474ad64cb001971ede5a5b67a 100644 (file)
--- a/compiler/rustc_builtin_macros/src/deriving/debug.rs
+++ b/compiler/rustc_builtin_macros/src/deriving/debug.rs
@@ -153,7 +153,10 @@ fn expr_for_field(
         let path_debug = cx.path_global(span, cx.std_path(&[sym::fmt, sym::Debug]));
         let ty_dyn_debug = cx.ty(
             span,
-            ast::TyKind::TraitObject(vec![cx.trait_bound(path_debug)], ast::TraitObjectSyntax::Dyn),
+            ast::TyKind::TraitObject(
+                vec![cx.trait_bound(path_debug, false)],
+                ast::TraitObjectSyntax::Dyn,
+            ),
         );
         let ty_slice = cx.ty(
             span,

diff --git a/compiler/rustc_builtin_macros/src/deriving/generic/mod.rs b/compiler/rustc_builtin_macros/src/deriving/generic/mod.rs
index 97de40bac34661f12d86e27e12a139ae76ebdd36..a8c0aeb787078140ba2cab22b851002e2bbdf3f6 100644 (file)
--- a/compiler/rustc_builtin_macros/src/deriving/generic/mod.rs
+++ b/compiler/rustc_builtin_macros/src/deriving/generic/mod.rs
@@ -605,18 +605,26 @@ fn create_derived_impl(
                     let bounds: Vec<_> = self
                         .additional_bounds
                         .iter()
-                        .map(|p| cx.trait_bound(p.to_path(cx, self.span, type_ident, generics)))
+                        .map(|p| {
+                            cx.trait_bound(
+                                p.to_path(cx, self.span, type_ident, generics),
+                                self.is_const,
+                            )
+                        })
                         .chain(
                             // Add a bound for the current trait.
                             self.skip_path_as_bound
                                 .not()
-                                .then(|| cx.trait_bound(trait_path.clone())),
+                                .then(|| cx.trait_bound(trait_path.clone(), self.is_const)),
                         )
                         .chain({
                             // Add a `Copy` bound if required.
                             if is_packed && self.needs_copy_as_bound_if_packed {
                                 let p = deriving::path_std!(marker::Copy);
-                                Some(cx.trait_bound(p.to_path(cx, self.span, type_ident, generics)))
+                                Some(cx.trait_bound(
+                                    p.to_path(cx, self.span, type_ident, generics),
+                                    self.is_const,
+                                ))
                             } else {
                                 None
                             }
@@ -694,18 +702,24 @@ fn create_derived_impl(
                         let mut bounds: Vec<_> = self
                             .additional_bounds
                             .iter()
-                            .map(|p| cx.trait_bound(p.to_path(cx, self.span, type_ident, generics)))
+                            .map(|p| {
+                                cx.trait_bound(
+                                    p.to_path(cx, self.span, type_ident, generics),
+                                    self.is_const,
+                                )
+                            })
                             .collect();
 
                         // Require the current trait.
-                        bounds.push(cx.trait_bound(trait_path.clone()));
+                        bounds.push(cx.trait_bound(trait_path.clone(), self.is_const));
 
                         // Add a `Copy` bound if required.
                         if is_packed && self.needs_copy_as_bound_if_packed {
                             let p = deriving::path_std!(marker::Copy);
-                            bounds.push(
-                                cx.trait_bound(p.to_path(cx, self.span, type_ident, generics)),
-                            );
+                            bounds.push(cx.trait_bound(
+                                p.to_path(cx, self.span, type_ident, generics),
+                                self.is_const,
+                            ));
                         }
 
                         let predicate = ast::WhereBoundPredicate {

diff --git a/compiler/rustc_builtin_macros/src/deriving/generic/ty.rs b/compiler/rustc_builtin_macros/src/deriving/generic/ty.rs
index c6f5f5d080706be7d41c7c52d8840edf6b545b42..aabd5b1f773f70baa3691862eb4a190f8068a8fb 100644 (file)
--- a/compiler/rustc_builtin_macros/src/deriving/generic/ty.rs
+++ b/compiler/rustc_builtin_macros/src/deriving/generic/ty.rs
@@ -154,7 +154,7 @@ fn mk_ty_param(
         .iter()
         .map(|b| {
             let path = b.to_path(cx, span, self_ident, self_generics);
-            cx.trait_bound(path)
+            cx.trait_bound(path, false)
         })
         .collect();
     cx.typaram(span, Ident::new(name, span), bounds, None)

diff --git a/compiler/rustc_expand/src/build.rs b/compiler/rustc_expand/src/build.rs
index 6cd56852f9d686942633ce3b258358c310d56469..b4c12651e7a2d36e7011fac4664f36d63f695c05 100644 (file)
--- a/compiler/rustc_expand/src/build.rs
+++ b/compiler/rustc_expand/src/build.rs
@@ -131,10 +131,14 @@ pub fn poly_trait_ref(&self, span: Span, path: ast::Path) -> ast::PolyTraitRef {
         }
     }
 
-    pub fn trait_bound(&self, path: ast::Path) -> ast::GenericBound {
+    pub fn trait_bound(&self, path: ast::Path, is_const: bool) -> ast::GenericBound {
         ast::GenericBound::Trait(
             self.poly_trait_ref(path.span, path),
-            ast::TraitBoundModifier::None,
+            if is_const {
+                ast::TraitBoundModifier::MaybeConst
+            } else {
+                ast::TraitBoundModifier::None
+            },
         )
     }
 

diff --git a/tests/ui/rfc-2632-const-trait-impl/const_derives/derive-const-with-params.rs b/tests/ui/rfc-2632-const-trait-impl/const_derives/derive-const-with-params.rs
new file mode 100644 (file)
index 0000000..72edfbc
--- /dev/null
+++ b/tests/ui/rfc-2632-const-trait-impl/const_derives/derive-const-with-params.rs
@@ -0,0 +1,13 @@
+// check-pass
+
+#![feature(derive_const)]
+#![feature(const_trait_impl)]
+
+#[derive_const(PartialEq)]
+pub struct Reverse<T>(T);
+
+const fn foo(a: Reverse<i32>, b: Reverse<i32>) -> bool {
+    a == b
+}
+
+fn main() {}