From 10b5c9951af4cc787905ca26f95509e059931067 Mon Sep 17 00:00:00 2001
From: David Tolnay <dtolnay@gmail.com>
Date: Thu, 11 Apr 2024 11:51:32 -0700
Subject: [PATCH] Drop support for compilers older than 1.47

---
 build.rs        | 27 ---------------------------
 src/receiver.rs | 21 +++++++++------------
 2 files changed, 9 insertions(+), 39 deletions(-)
 delete mode 100644 build.rs

diff --git a/build.rs b/build.rs
deleted file mode 100644
index 04c6250..0000000
--- a/build.rs
+++ /dev/null
@@ -1,27 +0,0 @@
-use std::env;
-use std::process::Command;
-use std::str;
-
-fn main() {
-    println!("cargo:rerun-if-changed=build.rs");
-
-    let compiler = match rustc_minor_version() {
-        Some(compiler) => compiler,
-        None => return,
-    };
-
-    if compiler < 47 {
-        println!("cargo:rustc-cfg=self_span_hack");
-    }
-}
-
-fn rustc_minor_version() -> Option<u32> {
-    let rustc = env::var_os("RUSTC")?;
-    let output = Command::new(rustc).arg("--version").output().ok()?;
-    let version = str::from_utf8(&output.stdout).ok()?;
-    let mut pieces = version.split('.');
-    if pieces.next() != Some("rustc 1") {
-        return None;
-    }
-    pieces.next()?.parse().ok()
-}
diff --git a/src/receiver.rs b/src/receiver.rs
index e032dc1..e4627f1 100644
--- a/src/receiver.rs
+++ b/src/receiver.rs
@@ -80,18 +80,15 @@ impl VisitMut for HasSelf {
 
 pub struct ReplaceSelf;
 
-impl ReplaceSelf {
-    #[cfg_attr(not(self_span_hack), allow(clippy::unused_self))]
-    fn prepend_underscore_to_self(&self, ident: &mut Ident) -> bool {
-        let modified = ident == "self";
-        if modified {
-            *ident = Ident::new("__self", ident.span());
-            #[cfg(self_span_hack)]
-            ident.set_span(self.0);
-        }
-        modified
+fn prepend_underscore_to_self(ident: &mut Ident) -> bool {
+    let modified = ident == "self";
+    if modified {
+        *ident = Ident::new("__self", ident.span());
     }
+    modified
+}
 
+impl ReplaceSelf {
     fn visit_token_stream(&mut self, tokens: &mut TokenStream) -> bool {
         let mut out = Vec::new();
         let mut modified = false;
@@ -110,7 +107,7 @@ impl ReplaceSelf {
             for tt in tokens {
                 match tt {
                     TokenTree::Ident(mut ident) => {
-                        *modified |= visitor.prepend_underscore_to_self(&mut ident);
+                        *modified |= prepend_underscore_to_self(&mut ident);
                         out.push(TokenTree::Ident(ident));
                     }
                     TokenTree::Group(group) => {
@@ -129,7 +126,7 @@ impl ReplaceSelf {
 
 impl VisitMut for ReplaceSelf {
     fn visit_ident_mut(&mut self, i: &mut Ident) {
-        self.prepend_underscore_to_self(i);
+        prepend_underscore_to_self(i);
     }
 
     fn visit_path_mut(&mut self, p: &mut Path) {