From b261501b71c64ede374f71abae914a71dd723072 Mon Sep 17 00:00:00 2001
From: Nicholas Nethercote <n.nethercote@gmail.com>
Date: Thu, 4 Jul 2024 11:27:39 +1000
Subject: [PATCH] Remove `HasSpan` trait.

The only place it is meaningfully used is in a panic message in
`TokenStream::from_ast`. But `node.span()` doesn't need to be printed
because `node` is also printed and it must contain the span.
---
 compiler/rustc_ast/src/ast_traits.rs  | 33 ---------------------------
 compiler/rustc_ast/src/lib.rs         |  2 +-
 compiler/rustc_ast/src/tokenstream.rs |  6 ++---
 compiler/rustc_resolve/src/late.rs    |  2 +-
 4 files changed, 5 insertions(+), 38 deletions(-)

diff --git a/compiler/rustc_ast/src/ast_traits.rs b/compiler/rustc_ast/src/ast_traits.rs
index 2cf811e9122..7754ca0a0f5 100644
--- a/compiler/rustc_ast/src/ast_traits.rs
+++ b/compiler/rustc_ast/src/ast_traits.rs
@@ -10,8 +10,6 @@ use crate::{AssocItem, Expr, ForeignItem, Item, NodeId};
 use crate::{AttrItem, AttrKind, Block, Pat, Path, Ty, Visibility};
 use crate::{AttrVec, Attribute, Stmt, StmtKind};
 
-use rustc_span::Span;
-
 use std::fmt;
 use std::marker::PhantomData;
 
@@ -91,37 +89,6 @@ impl<T: AstDeref<Target: HasNodeId>> HasNodeId for T {
     }
 }
 
-/// A trait for AST nodes having a span.
-pub trait HasSpan {
-    fn span(&self) -> Span;
-}
-
-macro_rules! impl_has_span {
-    ($($T:ty),+ $(,)?) => {
-        $(
-            impl HasSpan for $T {
-                fn span(&self) -> Span {
-                    self.span
-                }
-            }
-        )+
-    };
-}
-
-impl_has_span!(AssocItem, Block, Expr, ForeignItem, Item, Pat, Path, Stmt, Ty, Visibility);
-
-impl<T: AstDeref<Target: HasSpan>> HasSpan for T {
-    fn span(&self) -> Span {
-        self.ast_deref().span()
-    }
-}
-
-impl HasSpan for AttrItem {
-    fn span(&self) -> Span {
-        self.span()
-    }
-}
-
 /// A trait for AST nodes having (or not having) collected tokens.
 pub trait HasTokens {
     fn tokens(&self) -> Option<&LazyAttrTokenStream>;
diff --git a/compiler/rustc_ast/src/lib.rs b/compiler/rustc_ast/src/lib.rs
index 7ca950e50e6..846a108091f 100644
--- a/compiler/rustc_ast/src/lib.rs
+++ b/compiler/rustc_ast/src/lib.rs
@@ -44,7 +44,7 @@ pub mod tokenstream;
 pub mod visit;
 
 pub use self::ast::*;
-pub use self::ast_traits::{AstDeref, AstNodeWrapper, HasAttrs, HasNodeId, HasSpan, HasTokens};
+pub use self::ast_traits::{AstDeref, AstNodeWrapper, HasAttrs, HasNodeId, HasTokens};
 
 use rustc_data_structures::stable_hasher::{HashStable, StableHasher};
 
diff --git a/compiler/rustc_ast/src/tokenstream.rs b/compiler/rustc_ast/src/tokenstream.rs
index 06a669e7957..a84e33e5f92 100644
--- a/compiler/rustc_ast/src/tokenstream.rs
+++ b/compiler/rustc_ast/src/tokenstream.rs
@@ -14,7 +14,7 @@
 //! ownership of the original.
 
 use crate::ast::{AttrStyle, StmtKind};
-use crate::ast_traits::{HasAttrs, HasSpan, HasTokens};
+use crate::ast_traits::{HasAttrs, HasTokens};
 use crate::token::{self, Delimiter, Nonterminal, Token, TokenKind};
 use crate::AttrVec;
 
@@ -436,9 +436,9 @@ impl TokenStream {
         TokenStream::new(vec![TokenTree::token_alone(kind, span)])
     }
 
-    pub fn from_ast(node: &(impl HasAttrs + HasSpan + HasTokens + fmt::Debug)) -> TokenStream {
+    pub fn from_ast(node: &(impl HasAttrs + HasTokens + fmt::Debug)) -> TokenStream {
         let Some(tokens) = node.tokens() else {
-            panic!("missing tokens for node at {:?}: {:?}", node.span(), node);
+            panic!("missing tokens for node: {:?}", node);
         };
         let attrs = node.attrs();
         let attr_stream = if attrs.is_empty() {
diff --git a/compiler/rustc_resolve/src/late.rs b/compiler/rustc_resolve/src/late.rs
index ad4e222f4de..1d37264f96a 100644
--- a/compiler/rustc_resolve/src/late.rs
+++ b/compiler/rustc_resolve/src/late.rs
@@ -1744,7 +1744,7 @@ impl<'a: 'ast, 'b, 'ast, 'tcx> LateResolutionVisitor<'a, 'b, 'ast, 'tcx> {
                             ) {
                                 self.r.dcx().emit_err(errors::LendingIteratorReportError {
                                     lifetime: lifetime.ident.span,
-                                    ty: ty.span(),
+                                    ty: ty.span,
                                 });
                             } else {
                                 self.r.dcx().emit_err(errors::AnonymousLivetimeNonGatReportError {