Rollup merge of #66188 - Centril:fnsig, r=davidtwco

`MethodSig` -> `FnSig` & Use it in `ItemKind::Fn`

In both AST & HIR, rename `MethodSig` to `FnSig` and then proceed to use it in `ItemKind::Fn` so that the overall structure is more regular.

r? @davidtwco

5 files changed, 24 insertions, 26 deletions

diff --git a/src/libsyntax/ast.rs b/src/libsyntax/ast.rs
index 18151a1586c..b57d2238991 100644
--- a/src/libsyntax/ast.rs
+++ b/src/libsyntax/ast.rs
@@ -1501,10 +1501,10 @@ pub struct MutTy {
     pub mutbl: Mutability,
 }
 
-/// Represents a method's signature in a trait declaration,
-/// or in an implementation.
+/// Represents a function's signature in a trait declaration,
+/// trait implementation, or free function.
 #[derive(Clone, RustcEncodable, RustcDecodable, Debug)]
-pub struct MethodSig {
+pub struct FnSig {
     pub header: FnHeader,
     pub decl: P<FnDecl>,
 }
@@ -1528,7 +1528,7 @@ pub struct TraitItem {
 #[derive(Clone, RustcEncodable, RustcDecodable, Debug)]
 pub enum TraitItemKind {
     Const(P<Ty>, Option<P<Expr>>),
-    Method(MethodSig, Option<P<Block>>),
+    Method(FnSig, Option<P<Block>>),
     Type(GenericBounds, Option<P<Ty>>),
     Macro(Mac),
 }
@@ -1552,7 +1552,7 @@ pub struct ImplItem {
 #[derive(Clone, RustcEncodable, RustcDecodable, Debug)]
 pub enum ImplItemKind {
     Const(P<Ty>, P<Expr>),
-    Method(MethodSig, P<Block>),
+    Method(FnSig, P<Block>),
     TyAlias(P<Ty>),
     OpaqueTy(GenericBounds),
     Macro(Mac),
@@ -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 { .. }`.
diff --git a/src/libsyntax/mut_visit.rs b/src/libsyntax/mut_visit.rs
index 0c90652526d..7696ea48f93 100644
--- a/src/libsyntax/mut_visit.rs
+++ b/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>(MethodSig { header, decl }: &mut MethodSig, 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) => {
-            vis.visit_fn_decl(decl);
-            vis.visit_fn_header(header);
+        ItemKind::Fn(sig, generics, body) => {
+            visit_fn_sig(sig, vis);
             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),
diff --git a/src/libsyntax/parse/parser/item.rs b/src/libsyntax/parse/parser/item.rs
index 3c618d75d34..531ad532a54 100644
--- a/src/libsyntax/parse/parser/item.rs
+++ b/src/libsyntax/parse/parser/item.rs
@@ -8,7 +8,7 @@ use crate::ast::{ItemKind, ImplItem, ImplItemKind, TraitItem, TraitItemKind, Use
 use crate::ast::{PathSegment, IsAuto, Constness, IsAsync, Unsafety, Defaultness};
 use crate::ast::{Visibility, VisibilityKind, Mutability, FnHeader, ForeignItem, ForeignItemKind};
 use crate::ast::{Ty, TyKind, Generics, GenericBounds, TraitRef, EnumDef, VariantData, StructField};
-use crate::ast::{Mac, MacDelimiter, Block, BindingMode, FnDecl, MethodSig, SelfKind, Param};
+use crate::ast::{Mac, MacDelimiter, Block, BindingMode, FnDecl, FnSig, SelfKind, Param};
 use crate::parse::token;
 use crate::tokenstream::{TokenTree, TokenStream};
 use crate::symbol::{kw, sym};
@@ -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)))
     }
 
@@ -1897,14 +1897,14 @@ impl<'a> Parser<'a> {
     fn parse_method_sig(
         &mut self,
         is_name_required: fn(&token::Token) -> bool,
-    ) -> PResult<'a, (Ident, MethodSig, Generics)> {
+    ) -> PResult<'a, (Ident, FnSig, Generics)> {
         let header = self.parse_fn_front_matter()?;
         let (ident, decl, generics) = self.parse_fn_sig(ParamCfg {
             is_self_allowed: true,
             allow_c_variadic: false,
             is_name_required,
         })?;
-        Ok((ident, MethodSig { header, decl }, generics))
+        Ok((ident, FnSig { header, decl }, generics))
     }
 
     /// Parses all the "front matter" for a `fn` declaration, up to
diff --git a/src/libsyntax/print/pprust.rs b/src/libsyntax/print/pprust.rs
index 4ca4bdeb046..2203e8d9d06 100644
--- a/src/libsyntax/print/pprust.rs
+++ b/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,
-                    header,
+                    &sig.decl,
+                    sig.header,
                     Some(item.ident),
                     param_names,
                     &item.vis
@@ -1541,7 +1541,7 @@ impl<'a> State<'a> {
     crate fn print_method_sig(&mut self,
                             ident: ast::Ident,
                             generics: &ast::Generics,
-                            m: &ast::MethodSig,
+                            m: &ast::FnSig,
                             vis: &ast::Visibility)
                             {
         self.print_fn(&m.decl,
diff --git a/src/libsyntax/visit.rs b/src/libsyntax/visit.rs
index cfd160fd577..ea2dc357e6e 100644
--- a/src/libsyntax/visit.rs
+++ b/src/libsyntax/visit.rs
@@ -25,7 +25,7 @@ pub enum FnKind<'a> {
     ItemFn(Ident, &'a FnHeader, &'a Visibility, &'a Block),
 
     /// E.g., `fn foo(&self)`.
-    Method(Ident, &'a MethodSig, Option<&'a Visibility>, &'a Block),
+    Method(Ident, &'a FnSig, Option<&'a Visibility>, &'a Block),
 
     /// E.g., `|x, y| body`.
     Closure(&'a Expr),
@@ -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(FnKind::ItemFn(item.ident, header,
-                                            &item.vis, body),
-                             declaration,
+            visitor.visit_fn_header(&sig.header);
+            visitor.visit_fn(FnKind::ItemFn(item.ident, &sig.header, &item.vis, body),
+                             &sig.decl,
                              item.span,
                              item.id)
         }