make sure the right target is passed to #[cfg()] when it is parsed

Author: scrabsha

compiler/rustc_expand/src/expand.rs

@@ -1306,6 +1306,8 @@ trait InvocationCollectorNode: HasAttrs + HasNodeId + Sized {
     fn declared_idents(&self) -> Vec<Ident> {
         vec![]
     }
+
+    fn as_target(&self) -> Target;
 }
 
 impl InvocationCollectorNode for Box<ast::Item> {
@@ -1457,6 +1459,10 @@ impl InvocationCollectorNode for Box<ast::Item> {
             self.kind.ident().into_iter().collect()
         }
     }
+
+    fn as_target(&self) -> Target {
+        Target::from_ast_item(&*self)
+    }
 }
 
 struct TraitItemTag;
@@ -1498,6 +1504,9 @@ impl InvocationCollectorNode for AstNodeWrapper<Box<ast::AssocItem>, TraitItemTa
     fn flatten_outputs(items: impl Iterator<Item = Self::OutputTy>) -> Self::OutputTy {
         items.flatten().collect()
     }
+    fn as_target(&self) -> Target {
+        Target::from_assoc_item_kind(&self.wrapped.kind, AssocCtxt::Trait)
+    }
 }
 
 struct ImplItemTag;
@@ -1539,6 +1548,9 @@ impl InvocationCollectorNode for AstNodeWrapper<Box<ast::AssocItem>, ImplItemTag
     fn flatten_outputs(items: impl Iterator<Item = Self::OutputTy>) -> Self::OutputTy {
         items.flatten().collect()
     }
+    fn as_target(&self) -> Target {
+        Target::from_assoc_item_kind(&self.wrapped.kind, AssocCtxt::Impl { of_trait: false })
+    }
 }
 
 struct TraitImplItemTag;
@@ -1580,6 +1592,9 @@ impl InvocationCollectorNode for AstNodeWrapper<Box<ast::AssocItem>, TraitImplIt
     fn flatten_outputs(items: impl Iterator<Item = Self::OutputTy>) -> Self::OutputTy {
         items.flatten().collect()
     }
+    fn as_target(&self) -> Target {
+        Target::from_assoc_item_kind(&self.wrapped.kind, AssocCtxt::Impl { of_trait: true })
+    }
 }
 
 impl InvocationCollectorNode for Box<ast::ForeignItem> {
@@ -1602,6 +1617,17 @@ impl InvocationCollectorNode for Box<ast::ForeignItem> {
             _ => unreachable!(),
         }
     }
+    fn as_target(&self) -> Target {
+        match &self.kind {
+            ForeignItemKind::Static(_) => Target::ForeignStatic,
+            ForeignItemKind::Fn(_) => Target::ForeignFn,
+            ForeignItemKind::TyAlias(_) => Target::ForeignTy,
+            ForeignItemKind::MacCall(_) => {
+                // Turned into another kind of foreign item during macro expansion.
+                unreachable!();
+            }
+        }
+    }
 }
 
 impl InvocationCollectorNode for ast::Variant {
@@ -1615,6 +1641,9 @@ impl InvocationCollectorNode for ast::Variant {
     fn walk_flat_map(self, collector: &mut InvocationCollector<'_, '_>) -> Self::OutputTy {
         walk_flat_map_variant(collector, self)
     }
+    fn as_target(&self) -> Target {
+        Target::Variant
+    }
 }
 
 impl InvocationCollectorNode for ast::WherePredicate {
@@ -1628,6 +1657,9 @@ impl InvocationCollectorNode for ast::WherePredicate {
     fn walk_flat_map(self, collector: &mut InvocationCollector<'_, '_>) -> Self::OutputTy {
         walk_flat_map_where_predicate(collector, self)
     }
+    fn as_target(&self) -> Target {
+        Target::WherePredicate
+    }
 }
 
 impl InvocationCollectorNode for ast::FieldDef {
@@ -1641,6 +1673,9 @@ impl InvocationCollectorNode for ast::FieldDef {
     fn walk_flat_map(self, collector: &mut InvocationCollector<'_, '_>) -> Self::OutputTy {
         walk_flat_map_field_def(collector, self)
     }
+    fn as_target(&self) -> Target {
+        Target::Field
+    }
 }
 
 impl InvocationCollectorNode for ast::PatField {
@@ -1654,6 +1689,9 @@ impl InvocationCollectorNode for ast::PatField {
     fn walk_flat_map(self, collector: &mut InvocationCollector<'_, '_>) -> Self::OutputTy {
         walk_flat_map_pat_field(collector, self)
     }
+    fn as_target(&self) -> Target {
+        Target::PatField
+    }
 }
 
 impl InvocationCollectorNode for ast::ExprField {
@@ -1667,6 +1705,9 @@ impl InvocationCollectorNode for ast::ExprField {
     fn walk_flat_map(self, collector: &mut InvocationCollector<'_, '_>) -> Self::OutputTy {
         walk_flat_map_expr_field(collector, self)
     }
+    fn as_target(&self) -> Target {
+        Target::ExprField
+    }
 }
 
 impl InvocationCollectorNode for ast::Param {
@@ -1680,6 +1721,9 @@ impl InvocationCollectorNode for ast::Param {
     fn walk_flat_map(self, collector: &mut InvocationCollector<'_, '_>) -> Self::OutputTy {
         walk_flat_map_param(collector, self)
     }
+    fn as_target(&self) -> Target {
+        Target::Param
+    }
 }
 
 impl InvocationCollectorNode for ast::GenericParam {
@@ -1693,6 +1737,25 @@ impl InvocationCollectorNode for ast::GenericParam {
     fn walk_flat_map(self, collector: &mut InvocationCollector<'_, '_>) -> Self::OutputTy {
         walk_flat_map_generic_param(collector, self)
     }
+    fn as_target(&self) -> Target {
+        let mut has_default = false;
+        Target::GenericParam {
+            kind: match &self.kind {
+                rustc_ast::GenericParamKind::Lifetime => {
+                    rustc_hir::target::GenericParamKind::Lifetime
+                }
+                rustc_ast::GenericParamKind::Type { default } => {
+                    has_default = default.is_some();
+                    rustc_hir::target::GenericParamKind::Type
+                }
+                rustc_ast::GenericParamKind::Const { default, .. } => {
+                    has_default = default.is_some();
+                    rustc_hir::target::GenericParamKind::Const
+                }
+            },
+            has_default,
+        }
+    }
 }
 
 impl InvocationCollectorNode for ast::Arm {
@@ -1706,6 +1769,9 @@ impl InvocationCollectorNode for ast::Arm {
     fn walk_flat_map(self, collector: &mut InvocationCollector<'_, '_>) -> Self::OutputTy {
         walk_flat_map_arm(collector, self)
     }
+    fn as_target(&self) -> Target {
+        Target::Arm
+    }
 }
 
 impl InvocationCollectorNode for ast::Stmt {
@@ -1779,6 +1845,9 @@ impl InvocationCollectorNode for ast::Stmt {
             }
         }
     }
+    fn as_target(&self) -> Target {
+        Target::Statement
+    }
 }
 
 impl InvocationCollectorNode for ast::Crate {
@@ -1805,6 +1874,9 @@ impl InvocationCollectorNode for ast::Crate {
         // Standard prelude imports are left in the crate for backward compatibility.
         self.items.truncate(collector.cx.num_standard_library_imports);
     }
+    fn as_target(&self) -> Target {
+        Target::Crate
+    }
 }
 
 impl InvocationCollectorNode for ast::Ty {
@@ -1838,6 +1910,10 @@ impl InvocationCollectorNode for ast::Ty {
             _ => unreachable!(),
         }
     }
+    fn as_target(&self) -> Target {
+        // This is only used for attribute parsing, which are not allowed on types.
+        unreachable!()
+    }
 }
 
 impl InvocationCollectorNode for ast::Pat {
@@ -1861,6 +1937,9 @@ impl InvocationCollectorNode for ast::Pat {
             _ => unreachable!(),
         }
     }
+    fn as_target(&self) -> Target {
+        todo!();
+    }
 }
 
 impl InvocationCollectorNode for ast::Expr {
@@ -1887,6 +1966,9 @@ impl InvocationCollectorNode for ast::Expr {
             _ => unreachable!(),
         }
     }
+    fn as_target(&self) -> Target {
+        Target::Expression
+    }
 }
 
 struct OptExprTag;
@@ -1916,6 +1998,9 @@ impl InvocationCollectorNode for AstNodeWrapper<Box<ast::Expr>, OptExprTag> {
     fn pre_flat_map_node_collect_attr(cfg: &StripUnconfigured<'_>, attr: &ast::Attribute) {
         cfg.maybe_emit_expr_attr_err(attr);
     }
+    fn as_target(&self) -> Target {
+        Target::Expression
+    }
 }
 
 /// This struct is a hack to workaround unstable of `stmt_expr_attributes`.
@@ -1947,6 +2032,9 @@ impl InvocationCollectorNode for AstNodeWrapper<ast::Expr, MethodReceiverTag> {
             _ => unreachable!(),
         }
     }
+    fn as_target(&self) -> Target {
+        Target::Expression
+    }
 }
 
 fn build_single_delegations<'a, Node: InvocationCollectorNode>(
@@ -2210,7 +2298,7 @@ impl<'a, 'b> InvocationCollector<'a, 'b> {
 
     fn expand_cfg_true(
         &mut self,
-        node: &mut (impl HasAttrs + HasNodeId),
+        node: &mut impl InvocationCollectorNode,
         attr: ast::Attribute,
         pos: usize,
     ) -> EvalConfigResult {
@@ -2219,8 +2307,7 @@ impl<'a, 'b> InvocationCollector<'a, 'b> {
             &attr,
             attr.span,
             self.cfg().lint_node_id,
-            // Target doesn't matter for `cfg` parsing.
-            Target::Crate,
+            node.as_target(),
             self.cfg().features,
             ShouldEmit::ErrorsAndLints { recovery: Recovery::Allowed },
             parse_cfg,

tests/ui/cfg/suggest-any-or-all.stderr

@@ -7,12 +7,12 @@ LL | #[cfg(foo, bar)]
    |      expected a single argument here
    |
    = note: for more information, visit <https://doc.rust-lang.org/reference/conditional-compilation.html#the-cfg-attribute>
-help: if the crate should be enabled when all these predicates are, wrap them in `all`
+help: if the function should be enabled when all these predicates are, wrap them in `all`
    |
 LL - #[cfg(foo, bar)]
 LL + #[cfg(all(foo, bar))]
    |
-help: alternately, if the crate should be enabled when any these predicates are, wrap them in `any`
+help: alternately, if the function should be enabled when any these predicates are, wrap them in `any`
    |
 LL - #[cfg(foo, bar)]
 LL + #[cfg(any(foo, bar))]
@@ -27,7 +27,7 @@ LL | #[cfg()]
    |      expected a single argument here
    |
    = note: for more information, visit <https://doc.rust-lang.org/reference/conditional-compilation.html#the-cfg-attribute>
-help: if the crate should be disabled, use `#[cfg(false)]`
+help: if the struct should be disabled, use `#[cfg(false)]`
    |
 LL | #[cfg(false)]
    |       +++++

tests/ui/conditional-compilation/cfg-attr-syntax-validation.stderr

@@ -29,7 +29,7 @@ LL | #[cfg()]
    |      expected a single argument here
    |
    = note: for more information, visit <https://doc.rust-lang.org/reference/conditional-compilation.html#the-cfg-attribute>
-help: if the crate should be disabled, use `#[cfg(false)]`
+help: if the struct should be disabled, use `#[cfg(false)]`
    |
 LL | #[cfg(false)]
    |       +++++
@@ -43,12 +43,12 @@ LL | #[cfg(a, b)]
    |      expected a single argument here
    |
    = note: for more information, visit <https://doc.rust-lang.org/reference/conditional-compilation.html#the-cfg-attribute>
-help: if the crate should be enabled when all these predicates are, wrap them in `all`
+help: if the struct should be enabled when all these predicates are, wrap them in `all`
    |
 LL - #[cfg(a, b)]
 LL + #[cfg(all(a, b))]
    |
-help: alternately, if the crate should be enabled when any these predicates are, wrap them in `any`
+help: alternately, if the struct should be enabled when any these predicates are, wrap them in `any`
    |
 LL - #[cfg(a, b)]
 LL + #[cfg(any(a, b))]