parse associated statics.

Centril · Centril · commit f8d226446316 · 2020-02-15T20:57:12.000+01:00
diff --git a/src/librustc_ast_lowering/item.rs b/src/librustc_ast_lowering/item.rs
@@ -760,7 +760,8 @@ impl<'hir> LoweringContext<'_, 'hir> {
         let trait_item_def_id = self.resolver.definitions().local_def_id(i.id);
 
         let (generics, kind) = match i.kind {
-            AssocItemKind::Const(ref ty, ref default) => {
+            AssocItemKind::Static(ref ty, _, ref default) // Let's pretend this is a `const`.
+            | AssocItemKind::Const(ref ty, ref default) => {
                 let ty = self.lower_ty(ty, ImplTraitContext::disallowed());
                 let body = default.as_ref().map(|x| self.lower_const_body(i.span, Some(x)));
                 (hir::Generics::empty(), hir::TraitItemKind::Const(ty, body))
@@ -802,7 +803,10 @@ impl<'hir> LoweringContext<'_, 'hir> {
 
     fn lower_trait_item_ref(&mut self, i: &AssocItem) -> hir::TraitItemRef {
         let (kind, has_default) = match &i.kind {
-            AssocItemKind::Const(_, default) => (hir::AssocItemKind::Const, default.is_some()),
+            AssocItemKind::Static(_, _, default) // Let's pretend this is a `const` for recovery.
+            | AssocItemKind::Const(_, default) => {
+                (hir::AssocItemKind::Const, default.is_some())
+            }
             AssocItemKind::TyAlias(_, _, default) => (hir::AssocItemKind::Type, default.is_some()),
             AssocItemKind::Fn(sig, _, default) => {
                 (hir::AssocItemKind::Method { has_self: sig.decl.has_self() }, default.is_some())
@@ -827,7 +831,7 @@ impl<'hir> LoweringContext<'_, 'hir> {
         let impl_item_def_id = self.resolver.definitions().local_def_id(i.id);
 
         let (generics, kind) = match i.kind {
-            AssocItemKind::Const(ref ty, ref expr) => {
+            AssocItemKind::Static(ref ty, _, ref expr) | AssocItemKind::Const(ref ty, ref expr) => {
                 let ty = self.lower_ty(ty, ImplTraitContext::disallowed());
                 (
                     hir::Generics::empty(),
@@ -895,7 +899,8 @@ impl<'hir> LoweringContext<'_, 'hir> {
             vis: self.lower_visibility(&i.vis, Some(i.id)),
             defaultness: self.lower_defaultness(i.defaultness, true /* [1] */),
             kind: match &i.kind {
-                AssocItemKind::Const(..) => hir::AssocItemKind::Const,
+                AssocItemKind::Static(..) // Let's pretend this is a `const` for recovery.
+                | AssocItemKind::Const(..) => hir::AssocItemKind::Const,
                 AssocItemKind::TyAlias(_, _, ty) => {
                     match ty.as_deref().and_then(|ty| ty.kind.opaque_top_hack()) {
                         None => hir::AssocItemKind::Type,
diff --git a/src/librustc_ast_passes/ast_validation.rs b/src/librustc_ast_passes/ast_validation.rs
@@ -1250,8 +1250,13 @@ impl<'a> Visitor<'a> for AstValidator<'a> {
             }
         }
 
-        if let AssocItemKind::Const(..) = item.kind {
-            self.check_item_named(item.ident, "const");
+        match item.kind {
+            AssocItemKind::Const(..) => self.check_item_named(item.ident, "const"),
+            AssocItemKind::Static(..) => self
+                .err_handler()
+                .struct_span_err(item.span, "associated `static` items are not allowed")
+                .emit(),
+            _ => {}
         }
 
         self.with_in_trait_impl(false, |this| visit::walk_assoc_item(this, item, ctxt));
diff --git a/src/librustc_ast_pretty/pprust.rs b/src/librustc_ast_pretty/pprust.rs
@@ -1441,6 +1441,9 @@ impl<'a> State<'a> {
         self.print_outer_attributes(&item.attrs);
         self.print_defaultness(item.defaultness);
         match &item.kind {
+            ast::AssocItemKind::Static(ty, mutbl, expr) => {
+                self.print_item_const(item.ident, Some(*mutbl), ty, expr.as_deref(), &item.vis);
+            }
             ast::AssocItemKind::Const(ty, expr) => {
                 self.print_item_const(item.ident, None, ty, expr.as_deref(), &item.vis);
             }
diff --git a/src/librustc_parse/parser/item.rs b/src/librustc_parse/parser/item.rs
@@ -546,6 +546,7 @@ impl<'a> Parser<'a> {
                 1,
                 &[
                     kw::Impl,
+                    kw::Static,
                     kw::Const,
                     kw::Async,
                     kw::Fn,
@@ -670,8 +671,14 @@ impl<'a> Parser<'a> {
         } else if self.check_fn_front_matter() {
             let (ident, sig, generics, body) = self.parse_fn(at_end, &mut attrs, req_name)?;
             (ident, AssocItemKind::Fn(sig, generics, body))
+        } else if self.is_static_global() {
+            self.bump(); // `static`
+            let mutbl = self.parse_mutability();
+            let (ident, ty, expr) = self.parse_item_const_common(Some(mutbl))?;
+            (ident, AssocItemKind::Static(ty, mutbl, expr))
         } else if self.eat_keyword(kw::Const) {
-            self.parse_assoc_const()?
+            let (ident, ty, expr) = self.parse_item_const_common(None)?;
+            (ident, AssocItemKind::Const(ty, expr))
         } else if self.isnt_macro_invocation() {
             return Err(self.missing_assoc_item_kind_err("associated", self.prev_span));
         } else if self.token.is_path_start() {
@@ -688,15 +695,6 @@ impl<'a> Parser<'a> {
         Ok(AssocItem { id, span, ident, attrs, vis, defaultness, kind, tokens: None })
     }
 
-    /// This parses the grammar:
-    ///
-    ///     AssocConst = "const" Ident ":" Ty "=" Expr ";"
-    fn parse_assoc_const(&mut self) -> PResult<'a, (Ident, AssocItemKind)> {
-        self.expect_keyword(kw::Const)?;
-        let (ident, ty, expr) = self.parse_item_const_common(None)?;
-        Ok((ident, AssocItemKind::Const(ty, expr)))
-    }
-
     /// Parses the following grammar:
     ///
     ///     AssocTy = Ident ["<"...">"] [":" [GenericBounds]] ["where" ...] ["=" Ty]
diff --git a/src/librustc_resolve/build_reduced_graph.rs b/src/librustc_resolve/build_reduced_graph.rs
@@ -1251,7 +1251,8 @@ impl<'a, 'b> Visitor<'b> for BuildReducedGraphVisitor<'a, 'b> {
         // Add the item to the trait info.
         let item_def_id = self.r.definitions.local_def_id(item.id);
         let (res, ns) = match item.kind {
-            AssocItemKind::Const(..) => (Res::Def(DefKind::AssocConst, item_def_id), ValueNS),
+            AssocItemKind::Static(..) // Let's pretend it's a `const` for recovery.
+            | AssocItemKind::Const(..) => (Res::Def(DefKind::AssocConst, item_def_id), ValueNS),
             AssocItemKind::Fn(ref sig, _, _) => {
                 if sig.decl.has_self() {
                     self.r.has_self.insert(item_def_id);
diff --git a/src/librustc_resolve/def_collector.rs b/src/librustc_resolve/def_collector.rs
@@ -228,7 +228,9 @@ impl<'a> visit::Visitor<'a> for DefCollector<'a> {
                     body.as_deref(),
                 );
             }
-            AssocItemKind::Fn(..) | AssocItemKind::Const(..) => DefPathData::ValueNs(i.ident.name),
+            AssocItemKind::Fn(..) | AssocItemKind::Const(..) | AssocItemKind::Static(..) => {
+                DefPathData::ValueNs(i.ident.name)
+            }
             AssocItemKind::TyAlias(..) => DefPathData::TypeNs(i.ident.name),
             AssocItemKind::Macro(..) => return self.visit_macro_invoc(i.id),
         };
diff --git a/src/librustc_resolve/late.rs b/src/librustc_resolve/late.rs
@@ -836,7 +836,8 @@ impl<'a, 'b, 'ast> LateResolutionVisitor<'a, 'b, 'ast> {
                         for item in trait_items {
                             this.with_trait_items(trait_items, |this| {
                                 match &item.kind {
-                                    AssocItemKind::Const(ty, default) => {
+                                    AssocItemKind::Static(ty, _, default)
+                                    | AssocItemKind::Const(ty, default) => {
                                         this.visit_ty(ty);
                                         // Only impose the restrictions of `ConstRibKind` for an
                                         // actual constant expression in a provided default.
@@ -1109,7 +1110,7 @@ impl<'a, 'b, 'ast> LateResolutionVisitor<'a, 'b, 'ast> {
                                 for item in impl_items {
                                     use crate::ResolutionError::*;
                                     match &item.kind {
-                                        AssocItemKind::Const(..) => {
+                                        AssocItemKind::Static(..) | AssocItemKind::Const(..) => {
                                             debug!("resolve_implementation AssocItemKind::Const",);
                                             // If this is a trait impl, ensure the const
                                             // exists in trait
diff --git a/src/librustc_save_analysis/dump_visitor.rs b/src/librustc_save_analysis/dump_visitor.rs
@@ -1004,7 +1004,8 @@ impl<'l, 'tcx> DumpVisitor<'l, 'tcx> {
         self.process_macro_use(trait_item.span);
         let vis_span = trait_item.span.shrink_to_lo();
         match trait_item.kind {
-            ast::AssocItemKind::Const(ref ty, ref expr) => {
+            ast::AssocItemKind::Static(ref ty, _, ref expr)
+            | ast::AssocItemKind::Const(ref ty, ref expr) => {
                 self.process_assoc_const(
                     trait_item.id,
                     trait_item.ident,
@@ -1074,7 +1075,8 @@ impl<'l, 'tcx> DumpVisitor<'l, 'tcx> {
     fn process_impl_item(&mut self, impl_item: &'l ast::AssocItem, impl_id: DefId) {
         self.process_macro_use(impl_item.span);
         match impl_item.kind {
-            ast::AssocItemKind::Const(ref ty, ref expr) => {
+            ast::AssocItemKind::Static(ref ty, _, ref expr)
+            | ast::AssocItemKind::Const(ref ty, ref expr) => {
                 self.process_assoc_const(
                     impl_item.id,
                     impl_item.ident,
diff --git a/src/libsyntax/ast.rs b/src/libsyntax/ast.rs
@@ -2654,6 +2654,8 @@ pub enum AssocItemKind {
     /// A constant, `const $ident: $ty $def?;` where `def ::= "=" $expr? ;`.
     /// If `def` is parsed, then the constant is provided, and otherwise required.
     Const(P<Ty>, Option<P<Expr>>),
+    /// A static item (`static FOO: u8`).
+    Static(P<Ty>, Mutability, Option<P<Expr>>),
     /// A function.
     Fn(FnSig, Generics, Option<P<Block>>),
     /// A type.
diff --git a/src/libsyntax/mut_visit.rs b/src/libsyntax/mut_visit.rs
@@ -954,7 +954,7 @@ pub fn noop_flat_map_assoc_item<T: MutVisitor>(
     visitor.visit_vis(vis);
     visit_attrs(attrs, visitor);
     match kind {
-        AssocItemKind::Const(ty, expr) => {
+        AssocItemKind::Const(ty, expr) | AssocItemKind::Static(ty, _, expr) => {
             visitor.visit_ty(ty);
             visit_opt(expr, |expr| visitor.visit_expr(expr));
         }
diff --git a/src/libsyntax/visit.rs b/src/libsyntax/visit.rs
@@ -633,7 +633,7 @@ pub fn walk_assoc_item<'a, V: Visitor<'a>>(visitor: &mut V, item: &'a AssocItem,
     visitor.visit_ident(item.ident);
     walk_list!(visitor, visit_attribute, &item.attrs);
     match item.kind {
-        AssocItemKind::Const(ref ty, ref expr) => {
+        AssocItemKind::Const(ref ty, ref expr) | AssocItemKind::Static(ref ty, _, ref expr) => {
             visitor.visit_ty(ty);
             walk_list!(visitor, visit_expr, expr);
         }
diff --git a/src/test/ui/issues/issue-58856-2.stderr b/src/test/ui/issues/issue-58856-2.stderr
@@ -7,11 +7,11 @@ LL |     fn how_are_you(&self -> Empty {
    |                   |     help: `)` may belong here
    |                   unclosed delimiter
 
-error: expected one of `async`, `const`, `crate`, `default`, `extern`, `fn`, `pub`, `type`, `unsafe`, `}`, or identifier, found `)`
+error: expected one of `async`, `const`, `crate`, `default`, `extern`, `fn`, `pub`, `static`, `type`, `unsafe`, `}`, or identifier, found `)`
   --> $DIR/issue-58856-2.rs:11:1
    |
 LL |     }
-   |      - expected one of 11 possible tokens
+   |      - expected one of 12 possible tokens
 LL | }
    | ^ unexpected token
 
diff --git a/src/test/ui/issues/issue-60075.stderr b/src/test/ui/issues/issue-60075.stderr
@@ -4,7 +4,7 @@ error: expected one of `.`, `;`, `?`, `else`, or an operator, found `}`
 LL |         });
    |          ^ expected one of `.`, `;`, `?`, `else`, or an operator
 
-error: expected one of `async`, `const`, `crate`, `default`, `extern`, `fn`, `pub`, `type`, `unsafe`, `}`, or identifier, found `;`
+error: expected one of `async`, `const`, `crate`, `default`, `extern`, `fn`, `pub`, `static`, `type`, `unsafe`, `}`, or identifier, found `;`
   --> $DIR/issue-60075.rs:6:11
    |
 LL |     fn qux() -> Option<usize> {
diff --git a/src/test/ui/parser/assoc-static-semantic-fail.rs b/src/test/ui/parser/assoc-static-semantic-fail.rs
@@ -0,0 +1,43 @@
+// Semantically, we do not allow e.g., `static X: u8 = 0;` as an associated item.
+
+#![feature(specialization)]
+
+fn main() {}
+
+struct S;
+impl S {
+    static IA: u8 = 0;
+    //~^ ERROR associated `static` items are not allowed
+    static IB: u8;
+    //~^ ERROR associated `static` items are not allowed
+    default static IC: u8 = 0;
+    //~^ ERROR associated `static` items are not allowed
+    pub(crate) default static ID: u8;
+    //~^ ERROR associated `static` items are not allowed
+}
+
+trait T {
+    static TA: u8 = 0;
+    //~^ ERROR associated `static` items are not allowed
+    static TB: u8;
+    //~^ ERROR associated `static` items are not allowed
+    default static TC: u8 = 0;
+    //~^ ERROR associated `static` items are not allowed
+    //~| ERROR `default` is only allowed on items in
+    pub(crate) default static TD: u8;
+    //~^ ERROR associated `static` items are not allowed
+    //~| ERROR `default` is only allowed on items in
+    //~| ERROR unnecessary visibility qualifier
+}
+
+impl T for S {
+    static TA: u8 = 0;
+    //~^ ERROR associated `static` items are not allowed
+    static TB: u8;
+    //~^ ERROR associated `static` items are not allowed
+    default static TC: u8 = 0;
+    //~^ ERROR associated `static` items are not allowed
+    pub default static TD: u8;
+    //~^ ERROR associated `static` items are not allowed
+    //~| ERROR unnecessary visibility qualifier
+}
diff --git a/src/test/ui/parser/assoc-static-semantic-fail.stderr b/src/test/ui/parser/assoc-static-semantic-fail.stderr
@@ -0,0 +1,99 @@
+error: associated `static` items are not allowed
+  --> $DIR/assoc-static-semantic-fail.rs:9:5
+   |
+LL |     static IA: u8 = 0;
+   |     ^^^^^^^^^^^^^^^^^^
+
+error: associated `static` items are not allowed
+  --> $DIR/assoc-static-semantic-fail.rs:11:5
+   |
+LL |     static IB: u8;
+   |     ^^^^^^^^^^^^^^
+
+error: associated `static` items are not allowed
+  --> $DIR/assoc-static-semantic-fail.rs:13:5
+   |
+LL |     default static IC: u8 = 0;
+   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+error: associated `static` items are not allowed
+  --> $DIR/assoc-static-semantic-fail.rs:15:5
+   |
+LL |     pub(crate) default static ID: u8;
+   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+error: associated `static` items are not allowed
+  --> $DIR/assoc-static-semantic-fail.rs:20:5
+   |
+LL |     static TA: u8 = 0;
+   |     ^^^^^^^^^^^^^^^^^^
+
+error: associated `static` items are not allowed
+  --> $DIR/assoc-static-semantic-fail.rs:22:5
+   |
+LL |     static TB: u8;
+   |     ^^^^^^^^^^^^^^
+
+error: `default` is only allowed on items in `impl` definitions
+  --> $DIR/assoc-static-semantic-fail.rs:24:5
+   |
+LL |     default static TC: u8 = 0;
+   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+error: associated `static` items are not allowed
+  --> $DIR/assoc-static-semantic-fail.rs:24:5
+   |
+LL |     default static TC: u8 = 0;
+   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+error: `default` is only allowed on items in `impl` definitions
+  --> $DIR/assoc-static-semantic-fail.rs:27:5
+   |
+LL |     pub(crate) default static TD: u8;
+   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+error[E0449]: unnecessary visibility qualifier
+  --> $DIR/assoc-static-semantic-fail.rs:27:5
+   |
+LL |     pub(crate) default static TD: u8;
+   |     ^^^^^^^^^^
+
+error: associated `static` items are not allowed
+  --> $DIR/assoc-static-semantic-fail.rs:27:5
+   |
+LL |     pub(crate) default static TD: u8;
+   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+error: associated `static` items are not allowed
+  --> $DIR/assoc-static-semantic-fail.rs:34:5
+   |
+LL |     static TA: u8 = 0;
+   |     ^^^^^^^^^^^^^^^^^^
+
+error: associated `static` items are not allowed
+  --> $DIR/assoc-static-semantic-fail.rs:36:5
+   |
+LL |     static TB: u8;
+   |     ^^^^^^^^^^^^^^
+
+error: associated `static` items are not allowed
+  --> $DIR/assoc-static-semantic-fail.rs:38:5
+   |
+LL |     default static TC: u8 = 0;
+   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+error[E0449]: unnecessary visibility qualifier
+  --> $DIR/assoc-static-semantic-fail.rs:40:5
+   |
+LL |     pub default static TD: u8;
+   |     ^^^ `pub` not permitted here because it's implied
+
+error: associated `static` items are not allowed
+  --> $DIR/assoc-static-semantic-fail.rs:40:5
+   |
+LL |     pub default static TD: u8;
+   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+error: aborting due to 16 previous errors
+
+For more information about this error, try `rustc --explain E0449`.
diff --git a/src/test/ui/parser/assoc-static-syntactic-pass.rs b/src/test/ui/parser/assoc-static-syntactic-pass.rs
@@ -0,0 +1,29 @@
+// Syntactically, we do allow e.g., `static X: u8 = 0;` as an associated item.
+
+// check-pass
+
+fn main() {}
+
+#[cfg(FALSE)]
+impl S {
+    static IA: u8 = 0;
+    static IB: u8;
+    default static IC: u8 = 0;
+    pub(crate) default static ID: u8;
+}
+
+#[cfg(FALSE)]
+trait T {
+    static TA: u8 = 0;
+    static TB: u8;
+    default static TC: u8 = 0;
+    pub(crate) default static TD: u8;
+}
+
+#[cfg(FALSE)]
+impl T for S {
+    static TA: u8 = 0;
+    static TB: u8;
+    default static TC: u8 = 0;
+    pub default static TD: u8;
+}
diff --git a/src/test/ui/parser/issue-32446.stderr b/src/test/ui/parser/issue-32446.stderr
diff --git a/src/test/ui/parser/issue-41155.stderr b/src/test/ui/parser/issue-41155.stderr
diff --git a/src/test/ui/parser/macro/trait-non-item-macros.stderr b/src/test/ui/parser/macro/trait-non-item-macros.stderr
diff --git a/src/test/ui/parser/removed-syntax-static-fn.rs b/src/test/ui/parser/removed-syntax-static-fn.rs
diff --git a/src/test/ui/parser/removed-syntax-static-fn.stderr b/src/test/ui/parser/removed-syntax-static-fn.stderr

Original file line number	Diff line number	Diff line change
`@@ -1250,8 +1250,13 @@ impl<'a> Visitor<'a> for AstValidator<'a> {`
`1250`	`1250`	`}`
`1251`	`1251`	`}`
`1252`	`1252`
`1253`		`- if let AssocItemKind::Const(..) = item.kind {`
`1254`		`- self.check_item_named(item.ident, "const");`
	`1253`	`+ match item.kind {`
	`1254`	`+ AssocItemKind::Const(..) => self.check_item_named(item.ident, "const"),`
	`1255`	`+ AssocItemKind::Static(..) => self`
	`1256`	`+ .err_handler()`
	`1257`	+ .struct_span_err(item.span, "associated `static` items are not allowed")
	`1258`	`+ .emit(),`
	`1259`	`+ _ => {}`
`1255`	`1260`	`}`
`1256`	`1261`
`1257`	`1262`	`self.with_in_trait_impl(false, \|this\| visit::walk_assoc_item(this, item, ctxt));`
Original file line number	Diff line number	Diff line change
`@@ -954,7 +954,7 @@ pub fn noop_flat_map_assoc_item<T: MutVisitor>(`
`954`	`954`	`visitor.visit_vis(vis);`
`955`	`955`	`visit_attrs(attrs, visitor);`
`956`	`956`	`match kind {`
`957`		`- AssocItemKind::Const(ty, expr) => {`
	`957`	`+ AssocItemKind::Const(ty, expr) \| AssocItemKind::Static(ty, _, expr) => {`
`958`	`958`	`visitor.visit_ty(ty);`
`959`	`959`	`visit_opt(expr, \|expr\| visitor.visit_expr(expr));`
`960`	`960`	`}`