Rollup merge of #34316 - jseyfried:refactor_ast_stmt, r=eddyb

Refactor away `ast::Decl`, refactor `ast::Stmt`, and rename `ast::ExprKind::Again` to `ast::ExprKind::Continue`.

Author: jseyfried

src/librustc/hir/lowering.rs

@@ -238,19 +238,6 @@ impl<'a> LoweringContext<'a> {
         }
     }
 
-    fn lower_decl(&mut self, d: &Decl) -> P<hir::Decl> {
-        match d.node {
-            DeclKind::Local(ref l) => P(Spanned {
-                node: hir::DeclLocal(self.lower_local(l)),
-                span: d.span,
-            }),
-            DeclKind::Item(ref it) => P(Spanned {
-                node: hir::DeclItem(self.lower_item_id(it)),
-                span: d.span,
-            }),
-        }
-    }
-
     fn lower_ty_binding(&mut self, b: &TypeBinding) -> hir::TypeBinding {
         hir::TypeBinding {
             id: b.id,
@@ -1225,7 +1212,7 @@ impl<'a> LoweringContext<'a> {
                     hir::ExprPath(hir_qself, self.lower_path(path))
                 }
                 ExprKind::Break(opt_ident) => hir::ExprBreak(self.lower_opt_sp_ident(opt_ident)),
-                ExprKind::Again(opt_ident) => hir::ExprAgain(self.lower_opt_sp_ident(opt_ident)),
+                ExprKind::Continue(opt_ident) => hir::ExprAgain(self.lower_opt_sp_ident(opt_ident)),
                 ExprKind::Ret(ref e) => hir::ExprRet(e.as_ref().map(|x| self.lower_expr(x))),
                 ExprKind::InlineAsm(InlineAsm {
                         ref inputs,
@@ -1581,21 +1568,29 @@ impl<'a> LoweringContext<'a> {
 
     fn lower_stmt(&mut self, s: &Stmt) -> hir::Stmt {
         match s.node {
-            StmtKind::Decl(ref d, id) => {
-                Spanned {
-                    node: hir::StmtDecl(self.lower_decl(d), id),
+            StmtKind::Local(ref l) => Spanned {
+                node: hir::StmtDecl(P(Spanned {
+                    node: hir::DeclLocal(self.lower_local(l)),
                     span: s.span,
-                }
-            }
-            StmtKind::Expr(ref e, id) => {
+                }), s.id),
+                span: s.span,
+            },
+            StmtKind::Item(ref it) => Spanned {
+                node: hir::StmtDecl(P(Spanned {
+                    node: hir::DeclItem(self.lower_item_id(it)),
+                    span: s.span,
+                }), s.id),
+                span: s.span,
+            },
+            StmtKind::Expr(ref e) => {
                 Spanned {
-                    node: hir::StmtExpr(self.lower_expr(e), id),
+                    node: hir::StmtExpr(self.lower_expr(e), s.id),
                     span: s.span,
                 }
             }
-            StmtKind::Semi(ref e, id) => {
+            StmtKind::Semi(ref e) => {
                 Spanned {
-                    node: hir::StmtSemi(self.lower_expr(e), id),
+                    node: hir::StmtSemi(self.lower_expr(e), s.id),
                     span: s.span,
                 }
             }

src/librustc/lint/context.rs

@@ -1005,11 +1005,6 @@ impl<'a> ast_visit::Visitor for EarlyContext<'a> {
         ast_visit::walk_arm(self, a);
     }
 
-    fn visit_decl(&mut self, d: &ast::Decl) {
-        run_lints!(self, check_decl, early_passes, d);
-        ast_visit::walk_decl(self, d);
-    }
-
     fn visit_expr_post(&mut self, e: &ast::Expr) {
         run_lints!(self, check_expr_post, early_passes, e);
     }

src/librustc/lint/mod.rs

@@ -195,7 +195,6 @@ pub trait EarlyLintPass: LintPass {
     fn check_stmt(&mut self, _: &EarlyContext, _: &ast::Stmt) { }
     fn check_arm(&mut self, _: &EarlyContext, _: &ast::Arm) { }
     fn check_pat(&mut self, _: &EarlyContext, _: &ast::Pat) { }
-    fn check_decl(&mut self, _: &EarlyContext, _: &ast::Decl) { }
     fn check_expr(&mut self, _: &EarlyContext, _: &ast::Expr) { }
     fn check_expr_post(&mut self, _: &EarlyContext, _: &ast::Expr) { }
     fn check_ty(&mut self, _: &EarlyContext, _: &ast::Ty) { }

src/librustc_lint/unused.rs

@@ -365,12 +365,9 @@ impl EarlyLintPass for UnusedParens {
 
     fn check_stmt(&mut self, cx: &EarlyContext, s: &ast::Stmt) {
         let (value, msg) = match s.node {
-            ast::StmtKind::Decl(ref decl, _) => match decl.node {
-                ast::DeclKind::Local(ref local) => match local.init {
-                    Some(ref value) => (value, "assigned value"),
-                    None => return
-                },
-                _ => return
+            ast::StmtKind::Local(ref local) => match local.init {
+                Some(ref value) => (value, "assigned value"),
+                None => return
             },
             _ => return
         };

src/librustc_passes/ast_validation.rs

@@ -73,7 +73,7 @@ impl<'a> Visitor for AstValidator<'a> {
         match expr.node {
             ExprKind::While(_, _, Some(ident)) | ExprKind::Loop(_, Some(ident)) |
             ExprKind::WhileLet(_, _, _, Some(ident)) | ExprKind::ForLoop(_, _, _, Some(ident)) |
-            ExprKind::Break(Some(ident)) | ExprKind::Again(Some(ident)) => {
+            ExprKind::Break(Some(ident)) | ExprKind::Continue(Some(ident)) => {
                 self.check_label(ident.node, ident.span, expr.id);
             }
             _ => {}

src/librustc_resolve/build_reduced_graph.rs

@@ -30,10 +30,10 @@ use syntax::ast::Name;
 use syntax::attr;
 use syntax::parse::token;
 
-use syntax::ast::{Block, Crate, DeclKind};
+use syntax::ast::{Block, Crate};
 use syntax::ast::{ForeignItem, ForeignItemKind, Item, ItemKind};
 use syntax::ast::{Mutability, PathListItemKind};
-use syntax::ast::{Stmt, StmtKind, TraitItemKind};
+use syntax::ast::{StmtKind, TraitItemKind};
 use syntax::ast::{Variant, ViewPathGlob, ViewPathList, ViewPathSimple};
 use syntax::visit::{self, Visitor};
 
@@ -85,17 +85,11 @@ impl<'b> Resolver<'b> {
     }
 
     fn block_needs_anonymous_module(&mut self, block: &Block) -> bool {
-        fn is_item(statement: &Stmt) -> bool {
-            if let StmtKind::Decl(ref declaration, _) = statement.node {
-                if let DeclKind::Item(_) = declaration.node {
-                    return true;
-                }
-            }
-            false
-        }
-
         // If any statements are items, we need to create an anonymous module
-        block.stmts.iter().any(is_item)
+        block.stmts.iter().any(|statement| match statement.node {
+            StmtKind::Item(_) => true,
+            _ => false,
+        })
     }
 
     /// Constructs the reduced graph for one item.

src/librustc_resolve/lib.rs

@@ -2951,7 +2951,7 @@ impl<'a> Resolver<'a> {
                 })
             }
 
-            ExprKind::Break(Some(label)) | ExprKind::Again(Some(label)) => {
+            ExprKind::Break(Some(label)) | ExprKind::Continue(Some(label)) => {
                 match self.search_label(mtwt::resolve(label.node)) {
                     None => {
                         self.record_def(expr.id, err_path_resolution());

src/librustc_save_analysis/dump_visitor.rs

@@ -1423,8 +1423,7 @@ impl<'l, 'tcx: 'l, 'll, D: Dump +'ll> Visitor for DumpVisitor<'l, 'tcx, 'll, D>
     }
 
     fn visit_stmt(&mut self, s: &ast::Stmt) {
-        let id = s.node.id();
-        self.process_macro_use(s.span, id.unwrap());
+        self.process_macro_use(s.span, s.id);
         visit::walk_stmt(self, s)
     }
 

src/libsyntax/ast.rs

@@ -27,7 +27,6 @@ use tokenstream::{TokenTree};
 
 use std::fmt;
 use std::rc::Rc;
-use std::borrow::Cow;
 use std::hash::{Hash, Hasher};
 use serialize::{Encodable, Decodable, Encoder, Decoder};
 
@@ -811,41 +810,35 @@ impl UnOp {
 }
 
 /// A statement
-pub type Stmt = Spanned<StmtKind>;
+#[derive(Clone, PartialEq, Eq, RustcEncodable, RustcDecodable, Hash)]
+pub struct Stmt {
+    pub id: NodeId,
+    pub node: StmtKind,
+    pub span: Span,
+}
 
 impl fmt::Debug for Stmt {
     fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
-        write!(f, "stmt({}: {})",
-               self.node.id()
-                   .map_or(Cow::Borrowed("<macro>"),|id|Cow::Owned(id.to_string())),
-               pprust::stmt_to_string(self))
+        write!(f, "stmt({}: {})", self.id.to_string(), pprust::stmt_to_string(self))
     }
 }
 
 
 #[derive(Clone, PartialEq, Eq, RustcEncodable, RustcDecodable, Hash)]
 pub enum StmtKind {
-    /// Could be an item or a local (let) binding:
-    Decl(P<Decl>, NodeId),
+    /// A local (let) binding.
+    Local(P<Local>),
 
-    /// Expr without trailing semi-colon (must have unit type):
-    Expr(P<Expr>, NodeId),
+    /// An item definition.
+    Item(P<Item>),
 
-    /// Expr with trailing semi-colon (may have any type):
-    Semi(P<Expr>, NodeId),
+    /// Expr without trailing semi-colon (must have unit type).
+    Expr(P<Expr>),
 
-    Mac(P<Mac>, MacStmtStyle, ThinAttributes),
-}
+    /// Expr with trailing semi-colon (may have any type).
+    Semi(P<Expr>),
 
-impl StmtKind {
-    pub fn id(&self) -> Option<NodeId> {
-        match *self {
-            StmtKind::Decl(_, id) => Some(id),
-            StmtKind::Expr(_, id) => Some(id),
-            StmtKind::Semi(_, id) => Some(id),
-            StmtKind::Mac(..) => None,
-        }
-    }
+    Mac(P<(Mac, MacStmtStyle, ThinAttributes)>),
 }
 
 #[derive(Clone, Copy, PartialEq, Eq, RustcEncodable, RustcDecodable, Hash, Debug)]
@@ -875,16 +868,6 @@ pub struct Local {
     pub attrs: ThinAttributes,
 }
 
-pub type Decl = Spanned<DeclKind>;
-
-#[derive(Clone, PartialEq, Eq, RustcEncodable, RustcDecodable, Hash, Debug)]
-pub enum DeclKind {
-    /// A local (let) binding:
-    Local(P<Local>),
-    /// An item binding:
-    Item(P<Item>),
-}
-
 /// An arm of a 'match'.
 ///
 /// E.g. `0...10 => { println!("match!") }` as in
@@ -1053,7 +1036,7 @@ pub enum ExprKind {
     /// A `break`, with an optional label to break
     Break(Option<SpannedIdent>),
     /// A `continue`, with an optional label
-    Again(Option<SpannedIdent>),
+    Continue(Option<SpannedIdent>),
     /// A `return`, with an optional value to be returned
     Ret(Option<P<Expr>>),
 

src/libsyntax/attr.rs

@@ -16,8 +16,7 @@ pub use self::IntType::*;
 
 use ast;
 use ast::{AttrId, Attribute, Attribute_, MetaItem, MetaItemKind};
-use ast::{Stmt, StmtKind, DeclKind};
-use ast::{Expr, Item, Local, Decl};
+use ast::{Expr, Item, Local, Stmt, StmtKind};
 use codemap::{spanned, dummy_spanned, Spanned};
 use syntax_pos::{Span, BytePos};
 use errors::Handler;
@@ -909,38 +908,28 @@ impl<T: HasAttrs + 'static> HasAttrs for P<T> {
     }
 }
 
-impl HasAttrs for DeclKind {
-    fn attrs(&self) -> &[Attribute] {
-        match *self {
-            DeclKind::Local(ref local) => local.attrs(),
-            DeclKind::Item(ref item) => item.attrs(),
-        }
-    }
-
-    fn map_attrs<F: FnOnce(Vec<Attribute>) -> Vec<Attribute>>(self, f: F) -> Self {
-        match self {
-            DeclKind::Local(local) => DeclKind::Local(local.map_attrs(f)),
-            DeclKind::Item(item) => DeclKind::Item(item.map_attrs(f)),
-        }
-    }
-}
-
 impl HasAttrs for StmtKind {
     fn attrs(&self) -> &[Attribute] {
         match *self {
-            StmtKind::Decl(ref decl, _) => decl.attrs(),
-            StmtKind::Expr(ref expr, _) | StmtKind::Semi(ref expr, _) => expr.attrs(),
-            StmtKind::Mac(_, _, ref attrs) => attrs.attrs(),
+            StmtKind::Local(ref local) => local.attrs(),
+            StmtKind::Item(ref item) => item.attrs(),
+            StmtKind::Expr(ref expr) | StmtKind::Semi(ref expr) => expr.attrs(),
+            StmtKind::Mac(ref mac) => {
+                let (_, _, ref attrs) = **mac;
+                attrs.attrs()
+            }
         }
     }
 
     fn map_attrs<F: FnOnce(Vec<Attribute>) -> Vec<Attribute>>(self, f: F) -> Self {
         match self {
-            StmtKind::Decl(decl, id) => StmtKind::Decl(decl.map_attrs(f), id),
-            StmtKind::Expr(expr, id) => StmtKind::Expr(expr.map_attrs(f), id),
-            StmtKind::Semi(expr, id) => StmtKind::Semi(expr.map_attrs(f), id),
-            StmtKind::Mac(mac, style, attrs) =>
-                StmtKind::Mac(mac, style, attrs.map_attrs(f)),
+            StmtKind::Local(local) => StmtKind::Local(local.map_attrs(f)),
+            StmtKind::Item(item) => StmtKind::Item(item.map_attrs(f)),
+            StmtKind::Expr(expr) => StmtKind::Expr(expr.map_attrs(f)),
+            StmtKind::Semi(expr) => StmtKind::Semi(expr.map_attrs(f)),
+            StmtKind::Mac(mac) => StmtKind::Mac(mac.map(|(mac, style, attrs)| {
+                (mac, style, attrs.map_attrs(f))
+            })),
         }
     }
 }
@@ -967,4 +956,4 @@ derive_has_attrs_from_field! {
     Item, Expr, Local, ast::ForeignItem, ast::StructField, ast::ImplItem, ast::TraitItem, ast::Arm
 }
 
-derive_has_attrs_from_field! { Decl: .node, Stmt: .node, ast::Variant: .node.attrs }
+derive_has_attrs_from_field! { Stmt: .node, ast::Variant: .node.attrs }

src/libsyntax/config.rs

@@ -213,17 +213,10 @@ impl<'a> fold::Folder for StripUnconfigured<'a> {
     }
 
     fn fold_stmt(&mut self, stmt: ast::Stmt) -> SmallVector<ast::Stmt> {
-        let is_item = match stmt.node {
-            ast::StmtKind::Decl(ref decl, _) => match decl.node {
-                ast::DeclKind::Item(_) => true,
-                _ => false,
-            },
-            _ => false,
-        };
-
         // avoid calling `visit_stmt_or_expr_attrs` on items
-        if !is_item {
-            self.visit_stmt_or_expr_attrs(stmt.attrs());
+        match stmt.node {
+            ast::StmtKind::Item(_) => {}
+            _ => self.visit_stmt_or_expr_attrs(stmt.attrs()),
         }
 
         self.configure(stmt).map(|stmt| fold::noop_fold_stmt(stmt, self))

src/libsyntax/ext/base.rs

@@ -221,10 +221,11 @@ impl<F> IdentMacroExpander for F
 // Use a macro because forwarding to a simple function has type system issues
 macro_rules! make_stmts_default {
     ($me:expr) => {
-        $me.make_expr().map(|e| {
-            SmallVector::one(codemap::respan(
-                e.span, ast::StmtKind::Expr(e, ast::DUMMY_NODE_ID)))
-        })
+        $me.make_expr().map(|e| SmallVector::one(ast::Stmt {
+            id: ast::DUMMY_NODE_ID,
+            span: e.span,
+            node: ast::StmtKind::Expr(e),
+        }))
     }
 }
 
@@ -436,10 +437,11 @@ impl MacResult for DummyResult {
     }
 
     fn make_stmts(self: Box<DummyResult>) -> Option<SmallVector<ast::Stmt>> {
-        Some(SmallVector::one(
-            codemap::respan(self.span,
-                            ast::StmtKind::Expr(DummyResult::raw_expr(self.span),
-                                                ast::DUMMY_NODE_ID))))
+        Some(SmallVector::one(ast::Stmt {
+            id: ast::DUMMY_NODE_ID,
+            node: ast::StmtKind::Expr(DummyResult::raw_expr(self.span)),
+            span: self.span,
+        }))
     }
 }