Auto merge of #63127 - kper:pr, r=nikomatsakis

Cleanup: Consistently use `Param` instead of `Arg` #62426

Fixes #62426

src/librustc/error_codes.rs

@@ -2231,15 +2231,15 @@ register_diagnostics! {
     E0495, // cannot infer an appropriate lifetime due to conflicting requirements
     E0566, // conflicting representation hints
     E0623, // lifetime mismatch where both parameters are anonymous regions
-    E0628, // generators cannot have explicit arguments
+    E0628, // generators cannot have explicit parameters
     E0631, // type mismatch in closure arguments
     E0637, // "'_" is not a valid lifetime bound
     E0657, // `impl Trait` can only capture lifetimes bound at the fn level
     E0687, // in-band lifetimes cannot be used in `fn`/`Fn` syntax
     E0688, // in-band lifetimes cannot be mixed with explicit lifetime binders
     E0697, // closures cannot be static
     E0707, // multiple elided lifetimes used in arguments of `async fn`
-    E0708, // `async` non-`move` closures with arguments are not currently supported
+    E0708, // `async` non-`move` closures with parameters are not currently supported
     E0709, // multiple different lifetimes used in arguments of `async fn`
     E0710, // an unknown tool name found in scoped lint
     E0711, // a feature has been declared with conflicting stability attributes

src/librustc/hir/intravisit.rs

@@ -210,8 +210,8 @@ pub trait Visitor<'v> : Sized {
         }
     }
 
-    fn visit_arg(&mut self, arg: &'v Arg) {
-        walk_arg(self, arg)
+    fn visit_param(&mut self, param: &'v Param) {
+        walk_param(self, param)
     }
 
     /// Visits the top-level item and (optionally) nested items / impl items. See
@@ -400,7 +400,7 @@ pub fn walk_mod<'v, V: Visitor<'v>>(visitor: &mut V, module: &'v Mod, mod_hir_id
 }
 
 pub fn walk_body<'v, V: Visitor<'v>>(visitor: &mut V, body: &'v Body) {
-    walk_list!(visitor, visit_arg, &body.arguments);
+    walk_list!(visitor, visit_param, &body.params);
     visitor.visit_expr(&body.value);
 }
 
@@ -454,10 +454,10 @@ pub fn walk_trait_ref<'v, V>(visitor: &mut V, trait_ref: &'v TraitRef)
     visitor.visit_path(&trait_ref.path, trait_ref.hir_ref_id)
 }
 
-pub fn walk_arg<'v, V: Visitor<'v>>(visitor: &mut V, arg: &'v Arg) {
-    visitor.visit_id(arg.hir_id);
-    visitor.visit_pat(&arg.pat);
-    walk_list!(visitor, visit_attribute, &arg.attrs);
+pub fn walk_param<'v, V: Visitor<'v>>(visitor: &mut V, param: &'v Param) {
+    visitor.visit_id(param.hir_id);
+    visitor.visit_pat(&param.pat);
+    walk_list!(visitor, visit_attribute, &param.attrs);
 }
 
 pub fn walk_item<'v, V: Visitor<'v>>(visitor: &mut V, item: &'v Item) {

src/librustc/hir/lowering.rs

@@ -510,12 +510,12 @@ impl<'a> LoweringContext<'a> {
                             &f.generic_params
                         );
                         // Mirrors visit::walk_fn_decl
-                        for argument in &f.decl.inputs {
+                        for parameter in &f.decl.inputs {
                             // We don't lower the ids of argument patterns
                             self.with_hir_id_owner(None, |this| {
-                                this.visit_pat(&argument.pat);
+                                this.visit_pat(&parameter.pat);
                             });
-                            self.visit_ty(&argument.ty)
+                            self.visit_ty(&parameter.ty)
                         }
                         self.visit_fn_ret_ty(&f.decl.output)
                     }
@@ -735,7 +735,7 @@ impl<'a> LoweringContext<'a> {
     ///
     /// Presuming that in-band lifetimes are enabled, then
     /// `self.anonymous_lifetime_mode` will be updated to match the
-    /// argument while `f` is running (and restored afterwards).
+    /// parameter while `f` is running (and restored afterwards).
     fn collect_in_band_defs<T, F>(
         &mut self,
         parent_id: DefId,
@@ -880,7 +880,7 @@ impl<'a> LoweringContext<'a> {
     ///
     /// Presuming that in-band lifetimes are enabled, then
     /// `self.anonymous_lifetime_mode` will be updated to match the
-    /// argument while `f` is running (and restored afterwards).
+    /// parameter while `f` is running (and restored afterwards).
     fn add_in_band_defs<F, T>(
         &mut self,
         generics: &Generics,
@@ -1080,7 +1080,7 @@ impl<'a> LoweringContext<'a> {
                     ImplTraitContext::Disallowed(_) if self.is_in_dyn_type =>
                         (true, ImplTraitContext::OpaqueTy(None)),
 
-                    // We are in the argument position, but not within a dyn type:
+                    // We are in the parameter position, but not within a dyn type:
                     //
                     //     fn foo(x: impl Iterator<Item: Debug>)
                     //
@@ -1204,7 +1204,7 @@ impl<'a> LoweringContext<'a> {
                                 unsafety: this.lower_unsafety(f.unsafety),
                                 abi: f.abi,
                                 decl: this.lower_fn_decl(&f.decl, None, false, None),
-                                arg_names: this.lower_fn_args_to_names(&f.decl),
+                                param_names: this.lower_fn_params_to_names(&f.decl),
                             }))
                         },
                     )
@@ -2093,12 +2093,12 @@ impl<'a> LoweringContext<'a> {
         }
     }
 
-    fn lower_fn_args_to_names(&mut self, decl: &FnDecl) -> hir::HirVec<Ident> {
+    fn lower_fn_params_to_names(&mut self, decl: &FnDecl) -> hir::HirVec<Ident> {
         decl.inputs
             .iter()
-            .map(|arg| match arg.pat.node {
+            .map(|param| match param.pat.node {
                 PatKind::Ident(_, ident, _) => ident,
-                _ => Ident::new(kw::Invalid, arg.pat.span),
+                _ => Ident::new(kw::Invalid, param.pat.span),
             })
             .collect()
     }
@@ -2136,11 +2136,11 @@ impl<'a> LoweringContext<'a> {
         let inputs = self.with_anonymous_lifetime_mode(lt_mode, |this| {
             decl.inputs
                 .iter()
-                .map(|arg| {
+                .map(|param| {
                     if let Some((_, ibty)) = &mut in_band_ty_params {
-                        this.lower_ty_direct(&arg.ty, ImplTraitContext::Universal(ibty))
+                        this.lower_ty_direct(&param.ty, ImplTraitContext::Universal(ibty))
                     } else {
-                        this.lower_ty_direct(&arg.ty, ImplTraitContext::disallowed())
+                        this.lower_ty_direct(&param.ty, ImplTraitContext::disallowed())
                     }
                 })
                 .collect::<HirVec<_>>()
@@ -2205,7 +2205,7 @@ impl<'a> LoweringContext<'a> {
     //
     //     type OpaqueTy<generics_from_parent_fn> = impl Future<Output = T>;
     //
-    // `inputs`: lowered types of arguments to the function (used to collect lifetimes)
+    // `inputs`: lowered types of parameters to the function (used to collect lifetimes)
     // `output`: unlowered output type (`T` in `-> T`)
     // `fn_def_id`: `DefId` of the parent function (used to create child impl trait definition)
     // `opaque_ty_node_id`: `NodeId` of the opaque `impl Trait` type that should be created

src/librustc/hir/lowering/expr.rs

@@ -724,7 +724,7 @@ impl LoweringContext<'_> {
                         self.sess,
                         fn_decl_span,
                         E0628,
-                        "generators cannot have explicit arguments"
+                        "generators cannot have explicit parameters"
                     );
                     self.sess.abort_if_errors();
                 }
@@ -775,7 +775,7 @@ impl LoweringContext<'_> {
                     this.sess,
                     fn_decl_span,
                     E0708,
-                    "`async` non-`move` closures with arguments are not currently supported",
+                    "`async` non-`move` closures with parameters are not currently supported",
                 )
                 .help(
                     "consider using `let` statements to manually capture \

src/librustc/hir/lowering/item.rs

@@ -720,7 +720,7 @@ impl LoweringContext<'_> {
                             (
                                 // Disallow impl Trait in foreign items
                                 this.lower_fn_decl(fdec, None, false, None),
-                                this.lower_fn_args_to_names(fdec),
+                                this.lower_fn_params_to_names(fdec),
                             )
                         },
                     );
@@ -827,7 +827,7 @@ impl LoweringContext<'_> {
                 ),
             ),
             TraitItemKind::Method(ref sig, None) => {
-                let names = self.lower_fn_args_to_names(&sig.decl);
+                let names = self.lower_fn_params_to_names(&sig.decl);
                 let (generics, sig) = self.lower_method_sig(
                     &i.generics,
                     sig,
@@ -1028,10 +1028,10 @@ impl LoweringContext<'_> {
         }
     }
 
-    fn record_body(&mut self, arguments: HirVec<hir::Arg>, value: hir::Expr) -> hir::BodyId {
+    fn record_body(&mut self, params: HirVec<hir::Param>, value: hir::Expr) -> hir::BodyId {
         let body = hir::Body {
             generator_kind: self.generator_kind,
-            arguments,
+            params,
             value,
         };
         let id = body.id();
@@ -1041,21 +1041,21 @@ impl LoweringContext<'_> {
 
     fn lower_body(
         &mut self,
-        f: impl FnOnce(&mut LoweringContext<'_>) -> (HirVec<hir::Arg>, hir::Expr),
+        f: impl FnOnce(&mut LoweringContext<'_>) -> (HirVec<hir::Param>, hir::Expr),
     ) -> hir::BodyId {
         let prev_gen_kind = self.generator_kind.take();
-        let (arguments, result) = f(self);
-        let body_id = self.record_body(arguments, result);
+        let (parameters, result) = f(self);
+        let body_id = self.record_body(parameters, result);
         self.generator_kind = prev_gen_kind;
         body_id
     }
 
-    fn lower_arg(&mut self, arg: &Arg) -> hir::Arg {
-        hir::Arg {
-            attrs: self.lower_attrs(&arg.attrs),
-            hir_id: self.lower_node_id(arg.id),
-            pat: self.lower_pat(&arg.pat),
-            span: arg.span,
+    fn lower_param(&mut self, param: &Param) -> hir::Param {
+        hir::Param {
+            attrs: self.lower_attrs(&param.attrs),
+            hir_id: self.lower_node_id(param.id),
+            pat: self.lower_pat(&param.pat),
+            span: param.span,
         }
     }
 
@@ -1065,7 +1065,7 @@ impl LoweringContext<'_> {
         body: impl FnOnce(&mut LoweringContext<'_>) -> hir::Expr,
     ) -> hir::BodyId {
         self.lower_body(|this| (
-            decl.inputs.iter().map(|x| this.lower_arg(x)).collect(),
+            decl.inputs.iter().map(|x| this.lower_param(x)).collect(),
             body(this),
         ))
     }
@@ -1093,10 +1093,10 @@ impl LoweringContext<'_> {
         };
 
         self.lower_body(|this| {
-            let mut arguments: Vec<hir::Arg> = Vec::new();
+            let mut parameters: Vec<hir::Param> = Vec::new();
             let mut statements: Vec<hir::Stmt> = Vec::new();
 
-            // Async function arguments are lowered into the closure body so that they are
+            // Async function parameters are lowered into the closure body so that they are
             // captured and so that the drop order matches the equivalent non-async functions.
             //
             // from:
@@ -1121,13 +1121,13 @@ impl LoweringContext<'_> {
             //
             // If `<pattern>` is a simple ident, then it is lowered to a single
             // `let <pattern> = <pattern>;` statement as an optimization.
-            for (index, argument) in decl.inputs.iter().enumerate() {
-                let argument = this.lower_arg(argument);
-                let span = argument.pat.span;
+            for (index, parameter) in decl.inputs.iter().enumerate() {
+                let parameter = this.lower_param(parameter);
+                let span = parameter.pat.span;
 
                 // Check if this is a binding pattern, if so, we can optimize and avoid adding a
-                // `let <pat> = __argN;` statement. In this case, we do not rename the argument.
-                let (ident, is_simple_argument) = match argument.pat.node {
+                // `let <pat> = __argN;` statement. In this case, we do not rename the parameter.
+                let (ident, is_simple_parameter) = match parameter.pat.node {
                     hir::PatKind::Binding(hir::BindingAnnotation::Unannotated, _, ident, _) =>
                         (ident, true),
                     _ => {
@@ -1142,32 +1142,32 @@ impl LoweringContext<'_> {
                 let desugared_span =
                     this.mark_span_with_reason(DesugaringKind::Async, span, None);
 
-                // Construct an argument representing `__argN: <ty>` to replace the argument of the
+                // Construct a parameter representing `__argN: <ty>` to replace the parameter of the
                 // async function.
                 //
-                // If this is the simple case, this argument will end up being the same as the
-                // original argument, but with a different pattern id.
+                // If this is the simple case, this parameter will end up being the same as the
+                // original parameter, but with a different pattern id.
                 let mut stmt_attrs = ThinVec::new();
-                stmt_attrs.extend(argument.attrs.iter().cloned());
-                let (new_argument_pat, new_argument_id) = this.pat_ident(desugared_span, ident);
-                let new_argument = hir::Arg {
-                    attrs: argument.attrs,
-                    hir_id: argument.hir_id,
-                    pat: new_argument_pat,
-                    span: argument.span,
+                stmt_attrs.extend(parameter.attrs.iter().cloned());
+                let (new_parameter_pat, new_parameter_id) = this.pat_ident(desugared_span, ident);
+                let new_parameter = hir::Param {
+                    attrs: parameter.attrs,
+                    hir_id: parameter.hir_id,
+                    pat: new_parameter_pat,
+                    span: parameter.span,
                 };
 
 
-                if is_simple_argument {
+                if is_simple_parameter {
                     // If this is the simple case, then we only insert one statement that is
                     // `let <pat> = <pat>;`. We re-use the original argument's pattern so that
                     // `HirId`s are densely assigned.
-                    let expr = this.expr_ident(desugared_span, ident, new_argument_id);
+                    let expr = this.expr_ident(desugared_span, ident, new_parameter_id);
                     let stmt = this.stmt_let_pat(
                         stmt_attrs,
                         desugared_span,
                         Some(P(expr)),
-                        argument.pat,
+                        parameter.pat,
                         hir::LocalSource::AsyncFn
                     );
                     statements.push(stmt);
@@ -1179,7 +1179,7 @@ impl LoweringContext<'_> {
                     // let <pat> = __argN;
                     // ```
                     //
-                    // The first statement moves the argument into the closure and thus ensures
+                    // The first statement moves the parameter into the closure and thus ensures
                     // that the drop order is correct.
                     //
                     // The second statement creates the bindings that the user wrote.
@@ -1189,7 +1189,7 @@ impl LoweringContext<'_> {
                     // statement.
                     let (move_pat, move_id) = this.pat_ident_binding_mode(
                         desugared_span, ident, hir::BindingAnnotation::Mutable);
-                    let move_expr = this.expr_ident(desugared_span, ident, new_argument_id);
+                    let move_expr = this.expr_ident(desugared_span, ident, new_parameter_id);
                     let move_stmt = this.stmt_let_pat(
                         ThinVec::new(),
                         desugared_span,
@@ -1199,21 +1199,21 @@ impl LoweringContext<'_> {
                     );
 
                     // Construct the `let <pat> = __argN;` statement. We re-use the original
-                    // argument's pattern so that `HirId`s are densely assigned.
+                    // parameter's pattern so that `HirId`s are densely assigned.
                     let pattern_expr = this.expr_ident(desugared_span, ident, move_id);
                     let pattern_stmt = this.stmt_let_pat(
                         stmt_attrs,
                         desugared_span,
                         Some(P(pattern_expr)),
-                        argument.pat,
+                        parameter.pat,
                         hir::LocalSource::AsyncFn
                     );
 
                     statements.push(move_stmt);
                     statements.push(pattern_stmt);
                 };
 
-                arguments.push(new_argument);
+                parameters.push(new_parameter);
             }
 
             let async_expr = this.make_async_expr(
@@ -1222,7 +1222,7 @@ impl LoweringContext<'_> {
                     let body = this.lower_block_with_stmts(body, false, statements);
                     this.expr_block(body, ThinVec::new())
                 });
-            (HirVec::from(arguments), this.expr(body.span, async_expr, ThinVec::new()))
+            (HirVec::from(parameters), this.expr(body.span, async_expr, ThinVec::new()))
         })
     }
 

src/librustc/hir/map/collector.rs

@@ -363,11 +363,11 @@ impl<'a, 'hir> Visitor<'hir> for NodeCollector<'a, 'hir> {
         self.currently_in_body = prev_in_body;
     }
 
-    fn visit_arg(&mut self, arg: &'hir Arg) {
-        let node = Node::Arg(arg);
-        self.insert(arg.pat.span, arg.hir_id, node);
-        self.with_parent(arg.hir_id, |this| {
-            intravisit::walk_arg(this, arg);
+    fn visit_param(&mut self, param: &'hir Param) {
+        let node = Node::Param(param);
+        self.insert(param.pat.span, param.hir_id, node);
+        self.with_parent(param.hir_id, |this| {
+            intravisit::walk_param(this, param);
         });
     }