Remove extraneous Res checks in ast_lowering

camelid · camelid · commit 57276ce1b268 · 2024-10-28T14:06:32.000-04:00
diff --git a/compiler/rustc_ast_lowering/src/lib.rs b/compiler/rustc_ast_lowering/src/lib.rs
@@ -52,7 +52,7 @@ use rustc_data_structures::sorted_map::SortedMap;
 use rustc_data_structures::stable_hasher::{HashStable, StableHasher};
 use rustc_data_structures::sync::Lrc;
 use rustc_errors::{DiagArgFromDisplay, DiagCtxtHandle, StashKey};
-use rustc_hir::def::{CtorKind, DefKind, LifetimeRes, Namespace, PartialRes, PerNS, Res};
+use rustc_hir::def::{DefKind, LifetimeRes, Namespace, PartialRes, PerNS, Res};
 use rustc_hir::def_id::{CRATE_DEF_ID, LOCAL_CRATE, LocalDefId, LocalDefIdMap};
 use rustc_hir::{
     self as hir, ConstArg, GenericArg, HirId, ItemLocalMap, LangItem, MissingLifetimeKind,
@@ -2298,55 +2298,49 @@ impl<'a, 'hir> LoweringContext<'a, 'hir> {
         ty_id: NodeId,
         span: Span,
     ) -> &'hir hir::ConstArg<'hir> {
-        let ct_kind = match res {
-            // FIXME(min_generic_const_args): only allow one-segment const paths for now
-            Res::Def(
-                DefKind::ConstParam | DefKind::Const | DefKind::Ctor(_, CtorKind::Const),
-                _,
-            ) if path.is_potential_trivial_const_arg() => {
-                let qpath = self.lower_qpath(
-                    ty_id,
-                    &None,
-                    path,
-                    ParamMode::Optional,
-                    AllowReturnTypeNotation::No,
-                    ImplTraitContext::Disallowed(ImplTraitPosition::Path),
-                    None,
-                );
-                hir::ConstArgKind::Path(qpath)
-            }
-            _ => {
-                // Construct an AnonConst where the expr is the "ty"'s path.
+        // FIXME(min_generic_const_args): we only allow one-segment const paths for now
+        let ct_kind = if path.is_potential_trivial_const_arg() {
+            let qpath = self.lower_qpath(
+                ty_id,
+                &None,
+                path,
+                ParamMode::Optional,
+                AllowReturnTypeNotation::No,
+                ImplTraitContext::Disallowed(ImplTraitPosition::Path),
+                None,
+            );
+            hir::ConstArgKind::Path(qpath)
+        } else {
+            // Construct an AnonConst where the expr is the "ty"'s path.
 
-                let parent_def_id = self.current_def_id_parent;
-                let node_id = self.next_node_id();
-                let span = self.lower_span(span);
+            let parent_def_id = self.current_def_id_parent;
+            let node_id = self.next_node_id();
+            let span = self.lower_span(span);
 
-                // Add a definition for the in-band const def.
-                let def_id =
-                    self.create_def(parent_def_id, node_id, kw::Empty, DefKind::AnonConst, span);
-                let hir_id = self.lower_node_id(node_id);
+            // Add a definition for the in-band const def.
+            let def_id =
+                self.create_def(parent_def_id, node_id, kw::Empty, DefKind::AnonConst, span);
+            let hir_id = self.lower_node_id(node_id);
 
-                let path_expr = Expr {
-                    id: ty_id,
-                    kind: ExprKind::Path(None, path.clone()),
-                    span,
-                    attrs: AttrVec::new(),
-                    tokens: None,
-                };
+            let path_expr = Expr {
+                id: ty_id,
+                kind: ExprKind::Path(None, path.clone()),
+                span,
+                attrs: AttrVec::new(),
+                tokens: None,
+            };
 
-                let ct = self.with_new_scopes(span, |this| {
-                    self.arena.alloc(hir::AnonConst {
-                        def_id,
-                        hir_id,
-                        body: this.with_def_id_parent(def_id, |this| {
-                            this.lower_const_body(path_expr.span, Some(&path_expr))
-                        }),
-                        span,
-                    })
-                });
-                hir::ConstArgKind::Anon(ct)
-            }
+            let ct = self.with_new_scopes(span, |this| {
+                self.arena.alloc(hir::AnonConst {
+                    def_id,
+                    hir_id,
+                    body: this.with_def_id_parent(def_id, |this| {
+                        this.lower_const_body(path_expr.span, Some(&path_expr))
+                    }),
+                    span,
+                })
+            });
+            hir::ConstArgKind::Anon(ct)
         };
 
         self.arena.alloc(hir::ConstArg {
@@ -2375,19 +2369,8 @@ impl<'a, 'hir> LoweringContext<'a, 'hir> {
         } else {
             &anon.value
         };
-        let maybe_res =
-            self.resolver.get_partial_res(expr.id).and_then(|partial_res| partial_res.full_res());
-        debug!("res={:?}", maybe_res);
-        // FIXME(min_generic_const_args): for now we only lower params to ConstArgKind::Path
-        if let Some(res) = maybe_res
-            && let ExprKind::Path(qself, path) = &expr.kind
-            // FIXME(min_generic_const_args): only allow one-segment const paths for now
-            && let Res::Def(
-                DefKind::ConstParam
-                | DefKind::Const
-                | DefKind::Ctor(_, CtorKind::Const),
-                _,
-            ) = res
+        if let ExprKind::Path(qself, path) = &expr.kind
+            // FIXME(min_generic_const_args): we only allow one-segment const paths for now
             && path.is_potential_trivial_const_arg()
         {
             let qpath = self.lower_qpath(
diff --git a/tests/ui/const-generics/const-param-type-depends-on-const-param.min.stderr b/tests/ui/const-generics/const-param-type-depends-on-const-param.min.stderr
@@ -14,30 +14,6 @@ LL | pub struct SelfDependent<const N: [u8; N]>;
    |
    = note: const parameters may not be used in the type of const parameters
 
-error: `[u8; N]` is forbidden as the type of a const generic parameter
-  --> $DIR/const-param-type-depends-on-const-param.rs:11:47
-   |
-LL | pub struct Dependent<const N: usize, const X: [u8; N]>([(); N]);
-   |                                               ^^^^^^^
-   |
-   = note: the only supported types are integers, `bool`, and `char`
-help: add `#![feature(adt_const_params)]` to the crate attributes to enable more complex and user defined types
-   |
-LL + #![feature(adt_const_params)]
-   |
-
-error: `[u8; N]` is forbidden as the type of a const generic parameter
-  --> $DIR/const-param-type-depends-on-const-param.rs:15:35
-   |
-LL | pub struct SelfDependent<const N: [u8; N]>;
-   |                                   ^^^^^^^
-   |
-   = note: the only supported types are integers, `bool`, and `char`
-help: add `#![feature(adt_const_params)]` to the crate attributes to enable more complex and user defined types
-   |
-LL + #![feature(adt_const_params)]
-   |
-
-error: aborting due to 4 previous errors
+error: aborting due to 2 previous errors
 
 For more information about this error, try `rustc --explain E0770`.
diff --git a/tests/ui/const-generics/fn-const-param-infer.adt_const_params.stderr b/tests/ui/const-generics/fn-const-param-infer.adt_const_params.stderr
@@ -13,18 +13,7 @@ LL |     let _ = Checked::<{ generic_arg::<u32> }>;
    = note: expected fn pointer `fn(usize) -> _`
                  found fn item `fn(u32) -> _ {generic_arg::<u32>}`
 
-error[E0282]: type annotations needed
-  --> $DIR/fn-const-param-infer.rs:35:23
-   |
-LL |     let _ = Checked::<generic>;
-   |                       ^^^^^^^ cannot infer type of the type parameter `T` declared on the function `generic`
-   |
-help: consider specifying the generic argument
-   |
-LL |     let _ = Checked::<generic::<T>>;
-   |                              +++++
-
-error: aborting due to 3 previous errors
+error: aborting due to 2 previous errors
 
-Some errors have detailed explanations: E0282, E0308, E0741.
-For more information about an error, try `rustc --explain E0282`.
+Some errors have detailed explanations: E0308, E0741.
+For more information about an error, try `rustc --explain E0308`.
diff --git a/tests/ui/const-generics/fn-const-param-infer.full.stderr b/tests/ui/const-generics/fn-const-param-infer.full.stderr
@@ -13,18 +13,7 @@ LL |     let _ = Checked::<{ generic_arg::<u32> }>;
    = note: expected fn pointer `fn(usize) -> _`
                  found fn item `fn(u32) -> _ {generic_arg::<u32>}`
 
-error[E0282]: type annotations needed
-  --> $DIR/fn-const-param-infer.rs:35:23
-   |
-LL |     let _ = Checked::<generic>;
-   |                       ^^^^^^^ cannot infer type of the type parameter `T` declared on the function `generic`
-   |
-help: consider specifying the generic argument
-   |
-LL |     let _ = Checked::<generic::<T>>;
-   |                              +++++
-
-error: aborting due to 3 previous errors
+error: aborting due to 2 previous errors
 
-Some errors have detailed explanations: E0282, E0308, E0741.
-For more information about an error, try `rustc --explain E0282`.
+Some errors have detailed explanations: E0308, E0741.
+For more information about an error, try `rustc --explain E0308`.
diff --git a/tests/ui/const-generics/fn-const-param-infer.min.stderr b/tests/ui/const-generics/fn-const-param-infer.min.stderr
@@ -15,18 +15,6 @@ LL |     let _ = Checked::<{ generic_arg::<u32> }>;
    = note: expected fn pointer `fn(usize) -> _`
                  found fn item `fn(u32) -> _ {generic_arg::<u32>}`
 
-error[E0282]: type annotations needed
-  --> $DIR/fn-const-param-infer.rs:35:23
-   |
-LL |     let _ = Checked::<generic>;
-   |                       ^^^^^^^ cannot infer type of the type parameter `T` declared on the function `generic`
-   |
-help: consider specifying the generic argument
-   |
-LL |     let _ = Checked::<generic::<T>>;
-   |                              +++++
-
-error: aborting due to 3 previous errors
+error: aborting due to 2 previous errors
 
-Some errors have detailed explanations: E0282, E0308.
-For more information about an error, try `rustc --explain E0282`.
+For more information about this error, try `rustc --explain E0308`.
diff --git a/tests/ui/const-generics/generic_const_exprs/error_in_ty.stderr b/tests/ui/const-generics/generic_const_exprs/error_in_ty.stderr
@@ -6,30 +6,6 @@ LL | pub struct A<const z: [usize; x]> {}
    |                    |
    |                    similarly named const parameter `z` defined here
 
-error: `[usize; x]` is forbidden as the type of a const generic parameter
-  --> $DIR/error_in_ty.rs:6:23
-   |
-LL | pub struct A<const z: [usize; x]> {}
-   |                       ^^^^^^^^^^
-   |
-   = note: the only supported types are integers, `bool`, and `char`
-help: add `#![feature(adt_const_params)]` to the crate attributes to enable more complex and user defined types
-   |
-LL + #![feature(adt_const_params)]
-   |
-
-error[E0308]: mismatched types
-  --> $DIR/error_in_ty.rs:10:8
-   |
-LL | impl A<2> {
-   |        ^ expected `[usize; x]`, found integer
-
-error[E0308]: mismatched types
-  --> $DIR/error_in_ty.rs:16:8
-   |
-LL | impl A<2> {
-   |        ^ expected `[usize; x]`, found integer
-
 error[E0592]: duplicate definitions with name `B`
   --> $DIR/error_in_ty.rs:12:5
    |
@@ -39,7 +15,7 @@ LL |     pub const fn B() {}
 LL |     pub const fn B() {}
    |     ---------------- other definition for `B`
 
-error: aborting due to 5 previous errors
+error: aborting due to 2 previous errors
 
-Some errors have detailed explanations: E0308, E0425, E0592.
-For more information about an error, try `rustc --explain E0308`.
+Some errors have detailed explanations: E0425, E0592.
+For more information about an error, try `rustc --explain E0425`.
diff --git a/tests/ui/const-generics/issues/issue-62878.min.stderr b/tests/ui/const-generics/issues/issue-62878.min.stderr
@@ -6,18 +6,6 @@ LL | fn foo<const N: usize, const A: [u8; N]>() {}
    |
    = note: const parameters may not be used in the type of const parameters
 
-error: `[u8; N]` is forbidden as the type of a const generic parameter
-  --> $DIR/issue-62878.rs:5:33
-   |
-LL | fn foo<const N: usize, const A: [u8; N]>() {}
-   |                                 ^^^^^^^
-   |
-   = note: the only supported types are integers, `bool`, and `char`
-help: add `#![feature(adt_const_params)]` to the crate attributes to enable more complex and user defined types
-   |
-LL + #![feature(adt_const_params)]
-   |
-
 error[E0747]: type provided when a constant was expected
   --> $DIR/issue-62878.rs:10:11
    |
@@ -30,7 +18,7 @@ help: add `#![feature(generic_arg_infer)]` to the crate attributes to enable
 LL + #![feature(generic_arg_infer)]
    |
 
-error: aborting due to 3 previous errors
+error: aborting due to 2 previous errors
 
 Some errors have detailed explanations: E0747, E0770.
 For more information about an error, try `rustc --explain E0747`.
diff --git a/tests/ui/const-generics/issues/issue-71169.min.stderr b/tests/ui/const-generics/issues/issue-71169.min.stderr
@@ -6,18 +6,6 @@ LL | fn foo<const LEN: usize, const DATA: [u8; LEN]>() {}
    |
    = note: const parameters may not be used in the type of const parameters
 
-error: `[u8; LEN]` is forbidden as the type of a const generic parameter
-  --> $DIR/issue-71169.rs:5:38
-   |
-LL | fn foo<const LEN: usize, const DATA: [u8; LEN]>() {}
-   |                                      ^^^^^^^^^
-   |
-   = note: the only supported types are integers, `bool`, and `char`
-help: add `#![feature(adt_const_params)]` to the crate attributes to enable more complex and user defined types
-   |
-LL + #![feature(adt_const_params)]
-   |
-
-error: aborting due to 2 previous errors
+error: aborting due to 1 previous error
 
 For more information about this error, try `rustc --explain E0770`.
diff --git a/tests/ui/const-generics/not_wf_param_in_rpitit.stderr b/tests/ui/const-generics/not_wf_param_in_rpitit.stderr
@@ -18,29 +18,6 @@ LL | trait Trait<const N: dyn Trait = bar> {
    | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
    = note: see https://rustc-dev-guide.rust-lang.org/overview.html#queries and https://rustc-dev-guide.rust-lang.org/query.html for more information
 
-error[E0038]: the trait `Trait` cannot be made into an object
-  --> $DIR/not_wf_param_in_rpitit.rs:3:22
-   |
-LL | trait Trait<const N: dyn Trait = bar> {
-   |                      ^^^^^^^^^ `Trait` cannot be made into an object
-   |
-note: for a trait to be "dyn-compatible" it needs to allow building a vtable to allow the call to be resolvable dynamically; for more information visit <https://doc.rust-lang.org/reference/items/traits.html#object-safety>
-  --> $DIR/not_wf_param_in_rpitit.rs:9:14
-   |
-LL | trait Trait<const N: dyn Trait = bar> {
-   |       ----- this trait cannot be made into an object...
-...
-LL |     async fn a() {}
-   |              ^ ...because associated function `a` has no `self` parameter
-help: consider turning `a` into a method by giving it a `&self` argument
-   |
-LL |     async fn a(&self) {}
-   |                +++++
-help: alternatively, consider constraining `a` so it does not apply to trait objects
-   |
-LL |     async fn a() where Self: Sized {}
-   |                  +++++++++++++++++
-
 error[E0038]: the trait `Trait` cannot be made into an object
   --> $DIR/not_wf_param_in_rpitit.rs:3:13
    |
@@ -88,7 +65,7 @@ help: alternatively, consider constraining `a` so it does not apply to trait obj
 LL |     async fn a() where Self: Sized {}
    |                  +++++++++++++++++
 
-error: aborting due to 5 previous errors
+error: aborting due to 4 previous errors
 
 Some errors have detailed explanations: E0038, E0391, E0425.
 For more information about an error, try `rustc --explain E0038`.
diff --git a/tests/ui/generics/generic-function-item-where-type.stderr b/tests/ui/generics/generic-function-item-where-type.stderr
@@ -3,6 +3,9 @@ error[E0747]: constant provided when a type was expected
    |
 LL |     foo::<main>()
    |           ^^^^
+   |
+   = help: `main` is a function item, not a type
+   = help: function item types cannot be named directly
 
 error: aborting due to 1 previous error
 
diff --git a/tests/ui/privacy/privacy-ns1.stderr b/tests/ui/privacy/privacy-ns1.stderr
@@ -57,6 +57,9 @@ error[E0747]: constant provided when a type was expected
    |
 LL |     let _x: Box<Bar>;
    |                 ^^^
+   |
+   = help: `Bar` is a function item, not a type
+   = help: function item types cannot be named directly
 
 error: aborting due to 4 previous errors
 
diff --git a/tests/ui/privacy/privacy-ns2.stderr b/tests/ui/privacy/privacy-ns2.stderr
@@ -83,12 +83,18 @@ error[E0747]: constant provided when a type was expected
    |
 LL |     let _x : Box<Bar>;
    |                  ^^^
+   |
+   = help: `Bar` is a function item, not a type
+   = help: function item types cannot be named directly
 
 error[E0747]: constant provided when a type was expected
   --> $DIR/privacy-ns2.rs:48:17
    |
 LL |     let _x: Box<Bar>;
    |                 ^^^
+   |
+   = help: `Bar` is a function item, not a type
+   = help: function item types cannot be named directly
 
 error: aborting due to 8 previous errors
 
diff --git a/tests/ui/wf/ice-hir-wf-check-anon-const-issue-122199.stderr b/tests/ui/wf/ice-hir-wf-check-anon-const-issue-122199.stderr

Original file line number	Diff line number	Diff line change
`@@ -3,6 +3,9 @@ error[E0747]: constant provided when a type was expected`
`3`	`3`	`\|`
`4`	`4`	`LL \| foo::<main>()`
`5`	`5`	`\| ^^^^`
	`6`	`+ \|`
	`7`	+ = help: `main` is a function item, not a type
	`8`	`+ = help: function item types cannot be named directly`
`6`	`9`
`7`	`10`	`error: aborting due to 1 previous error`
`8`	`11`
Original file line number	Diff line number	Diff line change
`@@ -57,6 +57,9 @@ error[E0747]: constant provided when a type was expected`
`57`	`57`	`\|`
`58`	`58`	`LL \| let _x: Box<Bar>;`
`59`	`59`	`\| ^^^`
	`60`	`+ \|`
	`61`	+ = help: `Bar` is a function item, not a type
	`62`	`+ = help: function item types cannot be named directly`
`60`	`63`
`61`	`64`	`error: aborting due to 4 previous errors`
`62`	`65`