Auto merge of #91957 - nnethercote:rm-SymbolStr, r=oli-obk

Remove `SymbolStr`

This was originally proposed in https://github.com/rust-lang/rust/pull/74554#discussion_r466203544. As well as removing the icky `SymbolStr` type, it allows the removal of a lot of `&` and `*` occurrences.

Best reviewed one commit at a time.

r? `@oli-obk`

6 files changed, 7 insertions, 7 deletions

diff --git a/compiler/rustc_builtin_macros/src/asm.rs b/compiler/rustc_builtin_macros/src/asm.rs
index 768cb99510f..41856761916 100644
--- a/compiler/rustc_builtin_macros/src/asm.rs
+++ b/compiler/rustc_builtin_macros/src/asm.rs
@@ -573,7 +573,7 @@ fn expand_preparsed_asm(ecx: &mut ExtCtxt<'_>, args: AsmArgs) -> Option<ast::Inl
             template_snippet.as_ref().map(|s| Symbol::intern(s)),
             template_sp,
         ));
-        let template_str = &template_str.as_str();
+        let template_str = template_str.as_str();
 
         if let Some(InlineAsmArch::X86 | InlineAsmArch::X86_64) = ecx.sess.asm_arch {
             let find_span = |needle: &str| -> Span {
diff --git a/compiler/rustc_builtin_macros/src/concat.rs b/compiler/rustc_builtin_macros/src/concat.rs
index e5077d93674..59361510a67 100644
--- a/compiler/rustc_builtin_macros/src/concat.rs
+++ b/compiler/rustc_builtin_macros/src/concat.rs
@@ -21,7 +21,7 @@ pub fn expand_concat(
         match e.kind {
             ast::ExprKind::Lit(ref lit) => match lit.kind {
                 ast::LitKind::Str(ref s, _) | ast::LitKind::Float(ref s, _) => {
-                    accumulator.push_str(&s.as_str());
+                    accumulator.push_str(s.as_str());
                 }
                 ast::LitKind::Char(c) => {
                     accumulator.push(c);
diff --git a/compiler/rustc_builtin_macros/src/concat_idents.rs b/compiler/rustc_builtin_macros/src/concat_idents.rs
index 53a456b69ac..239bafb266a 100644
--- a/compiler/rustc_builtin_macros/src/concat_idents.rs
+++ b/compiler/rustc_builtin_macros/src/concat_idents.rs
@@ -29,7 +29,7 @@ pub fn expand_concat_idents<'cx>(
         } else {
             if let TokenTree::Token(token) = e {
                 if let Some((ident, _)) = token.ident() {
-                    res_str.push_str(&ident.name.as_str());
+                    res_str.push_str(ident.name.as_str());
                     continue;
                 }
             }
diff --git a/compiler/rustc_builtin_macros/src/derive.rs b/compiler/rustc_builtin_macros/src/derive.rs
index 31a35b9b7b4..47d7b6c259e 100644
--- a/compiler/rustc_builtin_macros/src/derive.rs
+++ b/compiler/rustc_builtin_macros/src/derive.rs
@@ -121,7 +121,7 @@ fn report_bad_target(sess: &Session, item: &Annotatable, span: Span) -> bool {
 
 fn report_unexpected_literal(sess: &Session, lit: &ast::Lit) {
     let help_msg = match lit.token.kind {
-        token::Str if rustc_lexer::is_ident(&lit.token.symbol.as_str()) => {
+        token::Str if rustc_lexer::is_ident(lit.token.symbol.as_str()) => {
             format!("try using `#[derive({})]`", lit.token.symbol)
         }
         _ => "for example, write `#[derive(Debug)]` for `Debug`".to_string(),
diff --git a/compiler/rustc_builtin_macros/src/env.rs b/compiler/rustc_builtin_macros/src/env.rs
index 6de12acfb94..285027fc632 100644
--- a/compiler/rustc_builtin_macros/src/env.rs
+++ b/compiler/rustc_builtin_macros/src/env.rs
@@ -80,11 +80,11 @@ pub fn expand_env<'cx>(
     }
 
     let sp = cx.with_def_site_ctxt(sp);
-    let value = env::var(&*var.as_str()).ok().as_deref().map(Symbol::intern);
+    let value = env::var(var.as_str()).ok().as_deref().map(Symbol::intern);
     cx.sess.parse_sess.env_depinfo.borrow_mut().insert((var, value));
     let e = match value {
         None => {
-            cx.span_err(sp, &msg.as_str());
+            cx.span_err(sp, msg.as_str());
             return DummyResult::any(sp);
         }
         Some(value) => cx.expr_str(sp, value),
diff --git a/compiler/rustc_builtin_macros/src/format.rs b/compiler/rustc_builtin_macros/src/format.rs
index cd16172fa31..407aaacb889 100644
--- a/compiler/rustc_builtin_macros/src/format.rs
+++ b/compiler/rustc_builtin_macros/src/format.rs
@@ -955,7 +955,7 @@ pub fn expand_preparsed_format_args(
         ast::StrStyle::Raw(raw) => Some(raw as usize),
     };
 
-    let fmt_str = &fmt_str.as_str(); // for the suggestions below
+    let fmt_str = fmt_str.as_str(); // for the suggestions below
     let fmt_snippet = ecx.source_map().span_to_snippet(fmt_sp).ok();
     let mut parser = parse::Parser::new(
         fmt_str,