ast::ItemKind::Fn: use ast::FnSig

src/librustc/hir/lowering/item.rs

@@ -306,7 +306,7 @@ impl LoweringContext<'_> {
                     self.lower_const_body(e)
                 )
             }
-            ItemKind::Fn(ref decl, header, ref generics, ref body) => {
+            ItemKind::Fn(FnSig { ref decl, header }, ref generics, ref body) => {
                 let fn_def_id = self.resolver.definitions().local_def_id(id);
                 self.with_new_scopes(|this| {
                     this.current_item = Some(ident.span);

src/librustc/hir/map/def_collector.rs

@@ -100,7 +100,7 @@ impl<'a> visit::Visitor<'a> for DefCollector<'a> {
 
         // Pick the def data. This need not be unique, but the more
         // information we encapsulate into, the better
-        let def_data = match i.kind {
+        let def_data = match &i.kind {
             ItemKind::Impl(..) => DefPathData::Impl,
             ItemKind::Mod(..) if i.ident.name == kw::Invalid => {
                 return visit::walk_item(self, i);
@@ -109,19 +109,14 @@ impl<'a> visit::Visitor<'a> for DefCollector<'a> {
             ItemKind::Enum(..) | ItemKind::Struct(..) | ItemKind::Union(..) |
             ItemKind::OpaqueTy(..) | ItemKind::ExternCrate(..) | ItemKind::ForeignMod(..) |
             ItemKind::TyAlias(..) => DefPathData::TypeNs(i.ident.name),
-            ItemKind::Fn(
+            ItemKind::Fn(sig, generics, body) if sig.header.asyncness.node.is_async() => {
-                ref decl,
-                ref header,
-                ref generics,
-                ref body,
-            ) if header.asyncness.node.is_async() => {
                 return self.visit_async_fn(
                     i.id,
                     i.ident.name,
                     i.span,
-                    header,
+                    &sig.header,
                     generics,
-                    decl,
+                    &sig.decl,
                     body,
                 )
             }

src/librustc_interface/util.rs

@@ -786,14 +786,17 @@ impl<'a> ReplaceBodyWithLoop<'a> {
             false
         }
     }
+
+    fn is_sig_const(sig: &ast::FnSig) -> bool {
+        sig.header.constness.node == ast::Constness::Const || Self::should_ignore_fn(&sig.decl)
+    }
 }
 
 impl<'a> MutVisitor for ReplaceBodyWithLoop<'a> {
     fn visit_item_kind(&mut self, i: &mut ast::ItemKind) {
         let is_const = match i {
             ast::ItemKind::Static(..) | ast::ItemKind::Const(..) => true,
-            ast::ItemKind::Fn(ref decl, ref header, _, _) =>
+            ast::ItemKind::Fn(ref sig, _, _) => Self::is_sig_const(sig),
-                header.constness.node == ast::Constness::Const || Self::should_ignore_fn(decl),
             _ => false,
         };
         self.run(is_const, |s| noop_visit_item_kind(i, s))
@@ -802,8 +805,7 @@ impl<'a> MutVisitor for ReplaceBodyWithLoop<'a> {
     fn flat_map_trait_item(&mut self, i: ast::TraitItem) -> SmallVec<[ast::TraitItem; 1]> {
         let is_const = match i.kind {
             ast::TraitItemKind::Const(..) => true,
-            ast::TraitItemKind::Method(ast::FnSig { ref decl, ref header, .. }, _) =>
+            ast::TraitItemKind::Method(ref sig, _) => Self::is_sig_const(sig),
-                header.constness.node == ast::Constness::Const || Self::should_ignore_fn(decl),
             _ => false,
         };
         self.run(is_const, |s| noop_flat_map_trait_item(i, s))
@@ -812,8 +814,7 @@ impl<'a> MutVisitor for ReplaceBodyWithLoop<'a> {
     fn flat_map_impl_item(&mut self, i: ast::ImplItem) -> SmallVec<[ast::ImplItem; 1]> {
         let is_const = match i.kind {
             ast::ImplItemKind::Const(..) => true,
-            ast::ImplItemKind::Method(ast::FnSig { ref decl, ref header, .. }, _) =>
+            ast::ImplItemKind::Method(ref sig, _) => Self::is_sig_const(sig),
-                header.constness.node == ast::Constness::Const || Self::should_ignore_fn(decl),
             _ => false,
         };
         self.run(is_const, |s| noop_flat_map_impl_item(i, s))

src/librustc_passes/ast_validation.rs

@@ -575,12 +575,12 @@ impl<'a> Visitor<'a> for AstValidator<'a> {
                         .note("only trait implementations may be annotated with default").emit();
                 }
             }
-            ItemKind::Fn(ref decl, ref header, ref generics, _) => {
+            ItemKind::Fn(ref sig, ref generics, _) => {
-                self.visit_fn_header(header);
+                self.visit_fn_header(&sig.header);
-                self.check_fn_decl(decl);
+                self.check_fn_decl(&sig.decl);
                 // We currently do not permit const generics in `const fn`, as
                 // this is tantamount to allowing compile-time dependent typing.
-                if header.constness.node == Constness::Const {
+                if sig.header.constness.node == Constness::Const {
                     // Look for const generics and error if we find any.
                     for param in &generics.params {
                         match param.kind {

src/librustc_resolve/late.rs

@@ -731,7 +731,7 @@ impl<'a, 'b> LateResolutionVisitor<'a, '_> {
         match item.kind {
             ItemKind::TyAlias(_, ref generics) |
             ItemKind::OpaqueTy(_, ref generics) |
-            ItemKind::Fn(_, _, ref generics, _) => {
+            ItemKind::Fn(_, ref generics, _) => {
                 self.with_generic_param_rib(generics, ItemRibKind(HasGenericParams::Yes),
                                             |this| visit::walk_item(this, item));
             }

src/librustc_save_analysis/dump_visitor.rs

@@ -1334,8 +1334,8 @@ impl<'l, 'tcx> Visitor<'l> for DumpVisitor<'l, 'tcx> {
                     );
                 }
             }
-            Fn(ref decl, ref header, ref ty_params, ref body) => {
+            Fn(ref sig, ref ty_params, ref body) => {
-                self.process_fn(item, &decl, &header, ty_params, &body)
+                self.process_fn(item, &sig.decl, &sig.header, ty_params, &body)
             }
             Static(ref typ, _, ref expr) => self.process_static_or_const_item(item, typ, expr),
             Const(ref typ, ref expr) => self.process_static_or_const_item(item, &typ, &expr),

src/librustc_save_analysis/lib.rs

@@ -180,7 +180,7 @@ impl<'l, 'tcx> SaveContext<'l, 'tcx> {
 
     pub fn get_item_data(&self, item: &ast::Item) -> Option<Data> {
         match item.kind {
-            ast::ItemKind::Fn(ref decl, .., ref generics, _) => {
+            ast::ItemKind::Fn(ref sig, .., ref generics, _) => {
                 let qualname = format!("::{}",
                     self.tcx.def_path_str(self.tcx.hir().local_def_id_from_node_id(item.id)));
                 filter!(self.span_utils, item.ident.span);
@@ -190,7 +190,7 @@ impl<'l, 'tcx> SaveContext<'l, 'tcx> {
                     span: self.span_from_span(item.ident.span),
                     name: item.ident.to_string(),
                     qualname,
-                    value: make_signature(decl, generics),
+                    value: make_signature(&sig.decl, generics),
                     parent: None,
                     children: vec![],
                     decl_id: None,

src/librustc_save_analysis/sig.rs

@@ -376,7 +376,7 @@ impl Sig for ast::Item {
 
                 Ok(extend_sig(ty, text, defs, vec![]))
             }
-            ast::ItemKind::Fn(ref decl, header, ref generics, _) => {
+            ast::ItemKind::Fn(ast::FnSig { ref decl, header }, ref generics, _) => {
                 let mut text = String::new();
                 if header.constness.node == ast::Constness::Const {
                     text.push_str("const ");

src/libsyntax/ast.rs

@@ -2433,7 +2433,7 @@ pub enum ItemKind {
     /// A function declaration (`fn`).
     ///
     /// E.g., `fn foo(bar: usize) -> usize { .. }`.
-    Fn(P<FnDecl>, FnHeader, Generics, P<Block>),
+    Fn(FnSig, Generics, P<Block>),
     /// A module declaration (`mod`).
     ///
     /// E.g., `mod foo;` or `mod foo { .. }`.

src/libsyntax/mut_visit.rs

@@ -357,7 +357,7 @@ pub fn visit_bounds<T: MutVisitor>(bounds: &mut GenericBounds, vis: &mut T) {
 }
 
 // No `noop_` prefix because there isn't a corresponding method in `MutVisitor`.
-pub fn visit_method_sig<T: MutVisitor>(FnSig { header, decl }: &mut FnSig, vis: &mut T) {
+pub fn visit_fn_sig<T: MutVisitor>(FnSig { header, decl }: &mut FnSig, vis: &mut T) {
     vis.visit_fn_header(header);
     vis.visit_fn_decl(decl);
 }
@@ -878,9 +878,8 @@ pub fn noop_visit_item_kind<T: MutVisitor>(kind: &mut ItemKind, vis: &mut T) {
             vis.visit_ty(ty);
             vis.visit_expr(expr);
         }
-        ItemKind::Fn(decl, header, generics, body) => {
+        ItemKind::Fn(sig, generics, body) => {
-            vis.visit_fn_decl(decl);
+            visit_fn_sig(sig, vis);
-            vis.visit_fn_header(header);
             vis.visit_generics(generics);
             vis.visit_block(body);
         }
@@ -938,7 +937,7 @@ pub fn noop_flat_map_trait_item<T: MutVisitor>(mut item: TraitItem, vis: &mut T)
             visit_opt(default, |default| vis.visit_expr(default));
         }
         TraitItemKind::Method(sig, body) => {
-            visit_method_sig(sig, vis);
+            visit_fn_sig(sig, vis);
             visit_opt(body, |body| vis.visit_block(body));
         }
         TraitItemKind::Type(bounds, default) => {
@@ -970,7 +969,7 @@ pub fn noop_flat_map_impl_item<T: MutVisitor>(mut item: ImplItem, visitor: &mut
             visitor.visit_expr(expr);
         }
         ImplItemKind::Method(sig, body) => {
-            visit_method_sig(sig, visitor);
+            visit_fn_sig(sig, visitor);
             visitor.visit_block(body);
         }
         ImplItemKind::TyAlias(ty) => visitor.visit_ty(ty),

src/libsyntax/parse/parser/item.rs

@@ -1800,7 +1800,7 @@ impl<'a> Parser<'a> {
             is_name_required: |_| true,
         })?;
         let (inner_attrs, body) = self.parse_inner_attrs_and_block()?;
-        let kind = ItemKind::Fn(decl, header, generics, body);
+        let kind = ItemKind::Fn(FnSig { decl, header }, generics, body);
         self.mk_item_with_info(attrs, lo, vis, (ident, kind, Some(inner_attrs)))
     }
 

src/libsyntax/print/pprust.rs

@@ -1199,11 +1199,11 @@ impl<'a> State<'a> {
                 self.s.word(";");
                 self.end(); // end the outer cbox
             }
-            ast::ItemKind::Fn(ref decl, header, ref param_names, ref body) => {
+            ast::ItemKind::Fn(ref sig, ref param_names, ref body) => {
                 self.head("");
                 self.print_fn(
-                    decl,
+                    &sig.decl,
-                    header,
+                    sig.header,
                     Some(item.ident),
                     param_names,
                     &item.vis

src/libsyntax/visit.rs

@@ -244,12 +244,11 @@ pub fn walk_item<'a, V: Visitor<'a>>(visitor: &mut V, item: &'a Item) {
             visitor.visit_ty(typ);
             visitor.visit_expr(expr);
         }
-        ItemKind::Fn(ref declaration, ref header, ref generics, ref body) => {
+        ItemKind::Fn(ref sig, ref generics, ref body) => {
             visitor.visit_generics(generics);
-            visitor.visit_fn_header(header);
+            visitor.visit_fn_header(&sig.header);
-            visitor.visit_fn(FnKind::ItemFn(item.ident, header,
+            visitor.visit_fn(FnKind::ItemFn(item.ident, &sig.header, &item.vis, body),
-                                            &item.vis, body),
+                             &sig.decl,
-                             declaration,
                              item.span,
                              item.id)
         }

src/libsyntax_ext/global_allocator.rs

@@ -1,7 +1,7 @@
 use crate::util::check_builtin_macro_attribute;
 
 use syntax::ast::{ItemKind, Mutability, Stmt, Ty, TyKind, Unsafety};
-use syntax::ast::{self, Param, Attribute, Expr, FnHeader, Generics, Ident};
+use syntax::ast::{self, Param, Attribute, Expr, FnSig, FnHeader, Generics, Ident};
 use syntax::expand::allocator::{AllocatorKind, AllocatorMethod, AllocatorTy, ALLOCATOR_METHODS};
 use syntax::ptr::P;
 use syntax::symbol::{kw, sym, Symbol};
@@ -73,15 +73,10 @@ impl AllocFnFactory<'_, '_> {
             .collect();
         let result = self.call_allocator(method.name, args);
         let (output_ty, output_expr) = self.ret_ty(&method.output, result);
-        let kind = ItemKind::Fn(
+        let decl = self.cx.fn_decl(abi_args, ast::FunctionRetTy::Ty(output_ty));
-            self.cx.fn_decl(abi_args, ast::FunctionRetTy::Ty(output_ty)),
+        let header = FnHeader { unsafety: Unsafety::Unsafe, ..FnHeader::default() };
-            FnHeader {
+        let sig = FnSig { decl, header };
-                unsafety: Unsafety::Unsafe,
+        let kind = ItemKind::Fn(sig, Generics::default(), self.cx.block_expr(output_expr));
-                ..FnHeader::default()
-            },
-            Generics::default(),
-            self.cx.block_expr(output_expr),
-        );
         let item = self.cx.item(
             self.span,
             self.cx.ident_of(&self.kind.fn_name(method.name), self.span),

src/libsyntax_ext/test.rs

@@ -310,15 +310,15 @@ fn test_type(cx: &ExtCtxt<'_>) -> TestType {
 fn has_test_signature(cx: &ExtCtxt<'_>, i: &ast::Item) -> bool {
     let has_should_panic_attr = attr::contains_name(&i.attrs, sym::should_panic);
     let ref sd = cx.parse_sess.span_diagnostic;
-    if let ast::ItemKind::Fn(ref decl, ref header, ref generics, _) = i.kind {
+    if let ast::ItemKind::Fn(ref sig, ref generics, _) = i.kind {
-        if header.unsafety == ast::Unsafety::Unsafe {
+        if sig.header.unsafety == ast::Unsafety::Unsafe {
             sd.span_err(
                 i.span,
                 "unsafe functions cannot be used for tests"
             );
             return false
         }
-        if header.asyncness.node.is_async() {
+        if sig.header.asyncness.node.is_async() {
             sd.span_err(
                 i.span,
                 "async functions cannot be used for tests"
@@ -329,13 +329,13 @@ fn has_test_signature(cx: &ExtCtxt<'_>, i: &ast::Item) -> bool {
 
         // If the termination trait is active, the compiler will check that the output
         // type implements the `Termination` trait as `libtest` enforces that.
-        let has_output = match decl.output {
+        let has_output = match sig.decl.output {
             ast::FunctionRetTy::Default(..) => false,
             ast::FunctionRetTy::Ty(ref t) if t.kind.is_unit() => false,
             _ => true
         };
 
-        if !decl.inputs.is_empty() {
+        if !sig.decl.inputs.is_empty() {
             sd.span_err(i.span, "functions used as tests can not have any arguments");
             return false;
         }
@@ -361,10 +361,10 @@ fn has_test_signature(cx: &ExtCtxt<'_>, i: &ast::Item) -> bool {
 }
 
 fn has_bench_signature(cx: &ExtCtxt<'_>, i: &ast::Item) -> bool {
-    let has_sig = if let ast::ItemKind::Fn(ref decl, _, _, _) = i.kind {
+    let has_sig = if let ast::ItemKind::Fn(ref sig, _, _) = i.kind {
         // N.B., inadequate check, but we're running
         // well before resolve, can't get too deep.
-        decl.inputs.len() == 1
+        sig.decl.inputs.len() == 1
     } else {
         false
     };

src/libsyntax_ext/test_harness.rs

@@ -306,10 +306,9 @@ fn mk_main(cx: &mut TestCtxt<'_>) -> P<ast::Item> {
         ecx.block(sp, vec![call_test_main])
     };
 
-    let main = ast::ItemKind::Fn(ecx.fn_decl(vec![], ast::FunctionRetTy::Ty(main_ret_ty)),
+    let decl = ecx.fn_decl(vec![], ast::FunctionRetTy::Ty(main_ret_ty));
-                           ast::FnHeader::default(),
+    let sig = ast::FnSig { decl, header: ast::FnHeader::default() };
-                           ast::Generics::default(),
+    let main = ast::ItemKind::Fn(sig, ast::Generics::default(), main_body);
-                           main_body);
 
     // Honor the reexport_test_harness_main attribute
     let main_id = match cx.reexport_test_harness_main {