Auto merge of #36066 - jseyfried:rollup, r=Manishearth

Batch up libsyntax breaking changes

Batch of the following syntax-[breaking-change] changes:
 - #35591: Add a field `span: Span` to `ast::Generics`.
 - #35618: Remove variant `Mod` of `ast::PathListItemKind` and refactor the remaining variant `ast::PathListKind::Ident` to a struct `ast::PathListKind_`.
 - #35480: Change uses of `Constness` in the AST to `Spanned<Constness>`.
  - c.f. `MethodSig`, `ItemKind`
 - #35728: Refactor `cx.pat_enum()` into `cx.pat_tuple_struct()` and `cx.pat_path()`.
 - #35850: Generalize the elements of lists in attributes from `MetaItem` to a new type `NestedMetaItem` that can represent a `MetaItem` or a literal.
 - #35917: Remove traits `AttrMetaMethods`, `AttributeMethods`, and `AttrNestedMetaItemMethods`.
  - Besides removing imports of these traits, this won't cause fallout.
 - Add a variant `Union` to `ItemKind` to future proof for `union` (c.f. #36016).
 - Remove inherent methods `attrs` and `fold_attrs` of `Annotatable`.
  - Use methods `attrs` and `map_attrs` of `HasAttrs` instead.

r? @Manishearth

src/librustc/hir/check_attr.rs

@@ -11,7 +11,6 @@
 use session::Session;
 
 use syntax::ast;
-use syntax::attr::AttrMetaMethods;
 use syntax::visit;
 use syntax::visit::Visitor;
 
@@ -52,18 +51,22 @@ impl<'a> CheckAttrVisitor<'a> {
                 return;
             }
         };
+
         for word in words {
-            let word: &str = &word.name();
-            let message = match word {
+            let name = match word.name() {
+                Some(word) => word,
+                None => continue,
+            };
+
+            let message = match &*name {
                 "C" => {
                     if target != Target::Struct && target != Target::Enum {
-                            "attribute should be applied to struct or enum"
+                        "attribute should be applied to struct or enum"
                     } else {
                         continue
                     }
                 }
-                "packed" |
-                "simd" => {
+                "packed" | "simd" => {
                     if target != Target::Struct {
                         "attribute should be applied to struct"
                     } else {
@@ -74,13 +77,14 @@ impl<'a> CheckAttrVisitor<'a> {
                 "i32" | "u32" | "i64" | "u64" |
                 "isize" | "usize" => {
                     if target != Target::Enum {
-                            "attribute should be applied to enum"
+                        "attribute should be applied to enum"
                     } else {
                         continue
                     }
                 }
                 _ => continue,
             };
+
             span_err!(self.sess, attr.span, E0517, "{}", message);
         }
     }

src/librustc/hir/fold.rs

@@ -12,8 +12,8 @@
 //! and returns a piece of the same type.
 
 use hir::*;
-use syntax::ast::{Name, NodeId, DUMMY_NODE_ID, Attribute, Attribute_, MetaItem};
-use syntax::ast::MetaItemKind;
+use syntax::ast::{Name, NodeId, DUMMY_NODE_ID, Attribute, Attribute_};
+use syntax::ast::{NestedMetaItem, NestedMetaItemKind, MetaItem, MetaItemKind};
 use hir;
 use syntax_pos::Span;
 use syntax::codemap::{respan, Spanned};
@@ -38,6 +38,10 @@ pub trait Folder : Sized {
         noop_fold_meta_items(meta_items, self)
     }
 
+    fn fold_meta_list_item(&mut self, list_item: NestedMetaItem) -> NestedMetaItem {
+        noop_fold_meta_list_item(list_item, self)
+    }
+
     fn fold_meta_item(&mut self, meta_item: P<MetaItem>) -> P<MetaItem> {
         noop_fold_meta_item(meta_item, self)
     }
@@ -271,16 +275,10 @@ pub fn noop_fold_view_path<T: Folder>(view_path: P<ViewPath>, fld: &mut T) -> P<
                     ViewPathList(fld.fold_path(path),
                                  path_list_idents.move_map(|path_list_ident| {
                                      Spanned {
-                                         node: match path_list_ident.node {
-                                             PathListIdent { id, name, rename } => PathListIdent {
-                                                 id: fld.new_id(id),
-                                                 name: name,
-                                                 rename: rename,
-                                             },
-                                             PathListMod { id, rename } => PathListMod {
-                                                 id: fld.new_id(id),
-                                                 rename: rename,
-                                             },
+                                         node: PathListItem_ {
+                                             id: fld.new_id(path_list_ident.node.id),
+                                             name: path_list_ident.node.name,
+                                             rename: path_list_ident.node.rename,
                                          },
                                          span: fld.new_span(path_list_ident.span),
                                      }
@@ -486,13 +484,26 @@ pub fn noop_fold_attribute<T: Folder>(at: Attribute, fld: &mut T) -> Option<Attr
     })
 }
 
+pub fn noop_fold_meta_list_item<T: Folder>(li: NestedMetaItem, fld: &mut T)
+    -> NestedMetaItem {
+    Spanned {
+        node: match li.node {
+            NestedMetaItemKind::MetaItem(mi) =>  {
+                NestedMetaItemKind::MetaItem(fld.fold_meta_item(mi))
+            },
+            NestedMetaItemKind::Literal(lit) => NestedMetaItemKind::Literal(lit)
+        },
+        span: fld.new_span(li.span)
+    }
+}
+
 pub fn noop_fold_meta_item<T: Folder>(mi: P<MetaItem>, fld: &mut T) -> P<MetaItem> {
     mi.map(|Spanned { node, span }| {
         Spanned {
             node: match node {
                 MetaItemKind::Word(id) => MetaItemKind::Word(id),
                 MetaItemKind::List(id, mis) => {
-                    MetaItemKind::List(id, mis.move_map(|e| fld.fold_meta_item(e)))
+                    MetaItemKind::List(id, mis.move_map(|e| fld.fold_meta_list_item(e)))
                 }
                 MetaItemKind::NameValue(id, s) => MetaItemKind::NameValue(id, s),
             },
@@ -577,13 +588,14 @@ pub fn noop_fold_opt_lifetime<T: Folder>(o_lt: Option<Lifetime>, fld: &mut T) ->
     o_lt.map(|lt| fld.fold_lifetime(lt))
 }
 
-pub fn noop_fold_generics<T: Folder>(Generics { ty_params, lifetimes, where_clause }: Generics,
+pub fn noop_fold_generics<T: Folder>(Generics {ty_params, lifetimes, where_clause, span}: Generics,
                                      fld: &mut T)
                                      -> Generics {
     Generics {
         ty_params: fld.fold_ty_params(ty_params),
         lifetimes: fld.fold_lifetime_defs(lifetimes),
         where_clause: fld.fold_where_clause(where_clause),
+        span: fld.new_span(span),
     }
 }
 

src/librustc/hir/intravisit.rs

@@ -444,12 +444,12 @@ pub fn walk_path<'v, V: Visitor<'v>>(visitor: &mut V, path: &'v Path) {
     }
 }
 
-pub fn walk_path_list_item<'v, V: Visitor<'v>>(visitor: &mut V,
-                                               _prefix: &'v Path,
-                                               item: &'v PathListItem) {
-    visitor.visit_id(item.node.id());
-    walk_opt_name(visitor, item.span, item.node.name());
-    walk_opt_name(visitor, item.span, item.node.rename());
+pub fn walk_path_list_item<'v, V>(visitor: &mut V, _prefix: &'v Path, item: &'v PathListItem)
+    where V: Visitor<'v>,
+{
+    visitor.visit_id(item.node.id);
+    visitor.visit_name(item.span, item.node.name);
+    walk_opt_name(visitor, item.span, item.node.rename);
 }
 
 pub fn walk_path_segment<'v, V: Visitor<'v>>(visitor: &mut V,

src/librustc/hir/lowering.rs

@@ -218,16 +218,10 @@ impl<'a> LoweringContext<'a> {
 
     fn lower_path_list_item(&mut self, path_list_ident: &PathListItem) -> hir::PathListItem {
         Spanned {
-            node: match path_list_ident.node {
-                PathListItemKind::Ident { id, name, rename } => hir::PathListIdent {
-                    id: id,
-                    name: name.name,
-                    rename: rename.map(|x| x.name),
-                },
-                PathListItemKind::Mod { id, rename } => hir::PathListMod {
-                    id: id,
-                    rename: rename.map(|x| x.name),
-                },
+            node: hir::PathListItem_ {
+                id: path_list_ident.node.id,
+                name: path_list_ident.node.name.name,
+                rename: path_list_ident.node.rename.map(|rename| rename.name),
             },
             span: path_list_ident.span,
         }
@@ -466,6 +460,7 @@ impl<'a> LoweringContext<'a> {
             ty_params: self.lower_ty_params(&g.ty_params),
             lifetimes: self.lower_lifetime_defs(&g.lifetimes),
             where_clause: self.lower_where_clause(&g.where_clause),
+            span: g.span,
         }
     }
 
@@ -643,6 +638,7 @@ impl<'a> LoweringContext<'a> {
                 let struct_def = self.lower_variant_data(struct_def);
                 hir::ItemStruct(struct_def, self.lower_generics(generics))
             }
+            ItemKind::Union(..) => panic!("`union` is not yet implemented"),
             ItemKind::DefaultImpl(unsafety, ref trait_ref) => {
                 hir::ItemDefaultImpl(self.lower_unsafety(unsafety),
                                      self.lower_trait_ref(trait_ref))
@@ -809,8 +805,8 @@ impl<'a> LoweringContext<'a> {
         }
     }
 
-    fn lower_constness(&mut self, c: Constness) -> hir::Constness {
-        match c {
+    fn lower_constness(&mut self, c: Spanned<Constness>) -> hir::Constness {
+        match c.node {
             Constness::Const => hir::Constness::Const,
             Constness::NotConst => hir::Constness::NotConst,
         }

src/librustc/hir/map/blocks.rs

@@ -23,13 +23,13 @@
 
 pub use self::Code::*;
 
+use hir as ast;
 use hir::map::{self, Node};
-use syntax::abi;
 use hir::{Block, FnDecl};
+use hir::intravisit::FnKind;
+use syntax::abi;
 use syntax::ast::{Attribute, Name, NodeId};
-use hir as ast;
 use syntax_pos::Span;
-use hir::intravisit::FnKind;
 
 /// An FnLikeNode is a Node that is like a fn, in that it has a decl
 /// and a body (as well as a NodeId, a span, etc).

src/librustc/hir/map/collector.rs

@@ -120,7 +120,7 @@ impl<'ast> Visitor<'ast> for NodeCollector<'ast> {
                     match view_path.node {
                         ViewPathList(_, ref paths) => {
                             for path in paths {
-                                this.insert(path.node.id(), NodeItem(i));
+                                this.insert(path.node.id, NodeItem(i));
                             }
                         }
                         _ => ()

src/librustc/hir/map/def_collector.rs

@@ -133,7 +133,7 @@ impl<'ast> visit::Visitor for DefCollector<'ast> {
         let def_data = match i.node {
             ItemKind::DefaultImpl(..) | ItemKind::Impl(..) =>
                 DefPathData::Impl,
-            ItemKind::Enum(..) | ItemKind::Struct(..) | ItemKind::Trait(..) |
+            ItemKind::Enum(..) | ItemKind::Struct(..) | ItemKind::Union(..) | ItemKind::Trait(..) |
             ItemKind::ExternCrate(..) | ItemKind::ForeignMod(..) | ItemKind::Ty(..) =>
                 DefPathData::TypeNs(i.ident.name.as_str()),
             ItemKind::Mod(..) => DefPathData::Module(i.ident.name.as_str()),
@@ -164,7 +164,7 @@ impl<'ast> visit::Visitor for DefCollector<'ast> {
                         });
                     }
                 }
-                ItemKind::Struct(ref struct_def, _) => {
+                ItemKind::Struct(ref struct_def, _) | ItemKind::Union(ref struct_def, _) => {
                     // If this is a tuple-like struct, register the constructor.
                     if !struct_def.is_struct() {
                         this.create_def(struct_def.id(),

src/librustc/hir/mod.rs

@@ -20,7 +20,6 @@ pub use self::FunctionRetTy::*;
 pub use self::ForeignItem_::*;
 pub use self::Item_::*;
 pub use self::Mutability::*;
-pub use self::PathListItem_::*;
 pub use self::PrimTy::*;
 pub use self::Stmt_::*;
 pub use self::TraitItem_::*;
@@ -36,7 +35,7 @@ use hir::def::Def;
 use hir::def_id::DefId;
 use util::nodemap::{NodeMap, FnvHashSet};
 
-use syntax_pos::{BytePos, mk_sp, Span, ExpnId};
+use syntax_pos::{mk_sp, Span, ExpnId, DUMMY_SP};
 use syntax::codemap::{self, respan, Spanned};
 use syntax::abi::Abi;
 use syntax::ast::{Name, NodeId, DUMMY_NODE_ID, AsmDialect};
@@ -301,6 +300,7 @@ pub struct Generics {
     pub lifetimes: HirVec<LifetimeDef>,
     pub ty_params: HirVec<TyParam>,
     pub where_clause: WhereClause,
+    pub span: Span,
 }
 
 impl Generics {
@@ -312,6 +312,7 @@ impl Generics {
                 id: DUMMY_NODE_ID,
                 predicates: HirVec::new(),
             },
+            span: DUMMY_SP,
         }
     }
 
@@ -326,38 +327,6 @@ impl Generics {
     pub fn is_parameterized(&self) -> bool {
         self.is_lt_parameterized() || self.is_type_parameterized()
     }
-
-    // Does return a span which includes lifetimes and type parameters,
-    // not where clause.
-    pub fn span(&self) -> Option<Span> {
-        if !self.is_parameterized() {
-            None
-        } else {
-            let mut span: Option<Span> = None;
-            for lifetime in self.lifetimes.iter() {
-                if let Some(ref mut span) = span {
-                    let life_span = lifetime.lifetime.span;
-                    span.hi = if span.hi > life_span.hi { span.hi } else { life_span.hi };
-                    span.lo = if span.lo < life_span.lo { span.lo } else { life_span.lo };
-                } else {
-                    span = Some(lifetime.lifetime.span.clone());
-                }
-            }
-            for ty_param in self.ty_params.iter() {
-                if let Some(ref mut span) = span {
-                    span.lo = if span.lo < ty_param.span.lo { span.lo } else { ty_param.span.lo };
-                    span.hi = if span.hi > ty_param.span.hi { span.hi } else { ty_param.span.hi };
-                } else {
-                    span = Some(ty_param.span.clone());
-                }
-            }
-            if let Some(ref mut span) = span {
-                span.lo = span.lo - BytePos(1);
-                span.hi = span.hi + BytePos(1);
-            }
-            span
-        }
-    }
 }
 
 /// A `where` clause in a definition
@@ -1337,39 +1306,11 @@ pub struct Variant_ {
 pub type Variant = Spanned<Variant_>;
 
 #[derive(Clone, PartialEq, Eq, RustcEncodable, RustcDecodable, Hash, Debug, Copy)]
-pub enum PathListItem_ {
-    PathListIdent {
-        name: Name,
-        /// renamed in list, eg `use foo::{bar as baz};`
-        rename: Option<Name>,
-        id: NodeId,
-    },
-    PathListMod {
-        /// renamed in list, eg `use foo::{self as baz};`
-        rename: Option<Name>,
-        id: NodeId,
-    },
-}
-
-impl PathListItem_ {
-    pub fn id(&self) -> NodeId {
-        match *self {
-            PathListIdent { id, .. } | PathListMod { id, .. } => id,
-        }
-    }
-
-    pub fn name(&self) -> Option<Name> {
-        match *self {
-            PathListIdent { name, .. } => Some(name),
-            PathListMod { .. } => None,
-        }
-    }
-
-    pub fn rename(&self) -> Option<Name> {
-        match *self {
-            PathListIdent { rename, .. } | PathListMod { rename, .. } => rename,
-        }
-    }
+pub struct PathListItem_ {
+    pub name: Name,
+    /// renamed in list, eg `use foo::{bar as baz};`
+    pub rename: Option<Name>,
+    pub id: NodeId,
 }
 
 pub type PathListItem = Spanned<PathListItem_>;