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`

4 files changed, 13 insertions, 12 deletions

diff --git a/compiler/rustc_codegen_llvm/src/attributes.rs b/compiler/rustc_codegen_llvm/src/attributes.rs
index bd25087c08e..7f82ce307d5 100644
--- a/compiler/rustc_codegen_llvm/src/attributes.rs
+++ b/compiler/rustc_codegen_llvm/src/attributes.rs
@@ -326,7 +326,7 @@ pub fn from_fn_attrs<'ll, 'tcx>(
         .target_features
         .iter()
         .flat_map(|f| {
-            let feature = &f.as_str();
+            let feature = f.as_str();
             llvm_util::to_llvm_feature(cx.tcx.sess, feature)
                 .into_iter()
                 .map(|f| format!("+{}", f))
@@ -351,7 +351,7 @@ pub fn from_fn_attrs<'ll, 'tcx>(
 
             let name =
                 codegen_fn_attrs.link_name.unwrap_or_else(|| cx.tcx.item_name(instance.def_id()));
-            let name = CString::new(&name.as_str()[..]).unwrap();
+            let name = CString::new(name.as_str()).unwrap();
             llvm::AddFunctionAttrStringValue(
                 llfn,
                 llvm::AttributePlace::Function,
diff --git a/compiler/rustc_codegen_llvm/src/base.rs b/compiler/rustc_codegen_llvm/src/base.rs
index 483b81d23bc..7b6ce5ea89b 100644
--- a/compiler/rustc_codegen_llvm/src/base.rs
+++ b/compiler/rustc_codegen_llvm/src/base.rs
@@ -79,7 +79,7 @@ pub fn compile_codegen_unit(tcx: TyCtxt<'_>, cgu_name: Symbol) -> (ModuleCodegen
             &[cgu_name.to_string(), cgu.size_estimate().to_string()],
         );
         // Instantiate monomorphizations without filling out definitions yet...
-        let llvm_module = ModuleLlvm::new(tcx, &cgu_name.as_str());
+        let llvm_module = ModuleLlvm::new(tcx, cgu_name.as_str());
         {
             let cx = CodegenCx::new(tcx, cgu, &llvm_module);
             let mono_items = cx.codegen_unit.items_in_deterministic_order(cx.tcx);
@@ -143,7 +143,7 @@ pub fn set_link_section(llval: &Value, attrs: &CodegenFnAttrs) {
         None => return,
     };
     unsafe {
-        let buf = SmallCStr::new(&sect.as_str());
+        let buf = SmallCStr::new(sect.as_str());
         llvm::LLVMSetSection(llval, buf.as_ptr());
     }
 }
diff --git a/compiler/rustc_codegen_llvm/src/context.rs b/compiler/rustc_codegen_llvm/src/context.rs
index fe55bf8686e..9f24a95482c 100644
--- a/compiler/rustc_codegen_llvm/src/context.rs
+++ b/compiler/rustc_codegen_llvm/src/context.rs
@@ -320,7 +320,7 @@ impl<'ll, 'tcx> CodegenCx<'ll, 'tcx> {
 
         let dbg_cx = if tcx.sess.opts.debuginfo != DebugInfo::None {
             let dctx = debuginfo::CrateDebugContext::new(llmod);
-            debuginfo::metadata::compile_unit_metadata(tcx, &codegen_unit.name().as_str(), &dctx);
+            debuginfo::metadata::compile_unit_metadata(tcx, codegen_unit.name().as_str(), &dctx);
             Some(dctx)
         } else {
             None
diff --git a/compiler/rustc_codegen_llvm/src/debuginfo/metadata.rs b/compiler/rustc_codegen_llvm/src/debuginfo/metadata.rs
index 960b02bf910..5f9c4189168 100644
--- a/compiler/rustc_codegen_llvm/src/debuginfo/metadata.rs
+++ b/compiler/rustc_codegen_llvm/src/debuginfo/metadata.rs
@@ -1037,7 +1037,7 @@ pub fn compile_unit_metadata<'ll, 'tcx>(
 ) -> &'ll DIDescriptor {
     let mut name_in_debuginfo = match tcx.sess.local_crate_source_file {
         Some(ref path) => path.clone(),
-        None => PathBuf::from(&*tcx.crate_name(LOCAL_CRATE).as_str()),
+        None => PathBuf::from(tcx.crate_name(LOCAL_CRATE).as_str()),
     };
 
     // To avoid breaking split DWARF, we need to ensure that each codegen unit
@@ -1371,7 +1371,7 @@ fn closure_saved_names_of_captured_variables(tcx: TyCtxt<'_>, def_id: DefId) ->
                 _ => return None,
             };
             let prefix = if is_ref { "_ref__" } else { "" };
-            Some(prefix.to_owned() + &var.name.as_str())
+            Some(prefix.to_owned() + var.name.as_str())
         })
         .collect::<Vec<_>>()
 }
@@ -1949,7 +1949,7 @@ enum VariantInfo<'a, 'tcx> {
 impl<'tcx> VariantInfo<'_, 'tcx> {
     fn map_struct_name<R>(&self, f: impl FnOnce(&str) -> R) -> R {
         match self {
-            VariantInfo::Adt(variant) => f(&variant.ident.as_str()),
+            VariantInfo::Adt(variant) => f(variant.ident.as_str()),
             VariantInfo::Generator { variant_index, .. } => {
                 f(&GeneratorSubsts::variant_name(*variant_index))
             }
@@ -2114,8 +2114,8 @@ fn prepare_enum_metadata<'ll, 'tcx>(
                 let item_name;
                 let discriminant_name = match enum_type.kind() {
                     ty::Adt(..) => {
-                        item_name = tcx.item_name(enum_def_id).as_str();
-                        &*item_name
+                        item_name = tcx.item_name(enum_def_id);
+                        item_name.as_str()
                     }
                     ty::Generator(..) => enum_name.as_str(),
                     _ => bug!(),
@@ -2448,7 +2448,7 @@ fn compute_type_parameters<'ll, 'tcx>(cx: &CodegenCx<'ll, 'tcx>, ty: Ty<'tcx>) -
                             cx.tcx.normalize_erasing_regions(ParamEnv::reveal_all(), ty);
                         let actual_type_metadata =
                             type_metadata(cx, actual_type, rustc_span::DUMMY_SP);
-                        let name = &name.as_str();
+                        let name = name.as_str();
                         Some(unsafe {
                             Some(llvm::LLVMRustDIBuilderCreateTemplateTypeParameter(
                                 DIB(cx),
@@ -2590,7 +2590,8 @@ pub fn create_global_var_metadata<'ll>(cx: &CodegenCx<'ll, '_>, def_id: DefId, g
     let is_local_to_unit = is_node_local_to_unit(cx, def_id);
     let variable_type = Instance::mono(cx.tcx, def_id).ty(cx.tcx, ty::ParamEnv::reveal_all());
     let type_metadata = type_metadata(cx, variable_type, span);
-    let var_name = tcx.item_name(def_id).as_str();
+    let var_name = tcx.item_name(def_id);
+    let var_name = var_name.as_str();
     let linkage_name = mangled_name_of_instance(cx, Instance::mono(tcx, def_id)).name;
     // When empty, linkage_name field is omitted,
     // which is what we want for no_mangle statics