From 1619597d2dbfa7d9f6cf4703475a560d5a04e865 Mon Sep 17 00:00:00 2001
From: clubby789 <jamie@hill-daniel.co.uk>
Date: Wed, 27 Nov 2024 17:52:57 +0000
Subject: [PATCH] Replace `Symbol::intern` calls with preinterned symbols

---
 compiler/rustc_ast_passes/src/feature_gate.rs  |  5 +++--
 .../rustc_borrowck/src/universal_regions.rs    | 10 ++++------
 .../rustc_codegen_cranelift/src/driver/jit.rs  |  9 ++-------
 compiler/rustc_codegen_cranelift/src/lib.rs    |  9 ++-------
 .../src/collect/generics_of.rs                 |  2 +-
 .../rustc_hir_typeck/src/method/suggest.rs     |  2 +-
 compiler/rustc_lint/src/unused.rs              |  2 +-
 compiler/rustc_metadata/src/creader.rs         |  4 ++--
 compiler/rustc_metadata/src/rmeta/decoder.rs   |  8 +++-----
 compiler/rustc_parse/src/parser/ty.rs          |  4 ++--
 compiler/rustc_resolve/src/late/diagnostics.rs |  4 ++--
 compiler/rustc_resolve/src/lib.rs              |  2 +-
 compiler/rustc_session/src/output.rs           |  2 +-
 compiler/rustc_span/src/symbol.rs              | 18 ++++++++++++++++++
 .../src/traits/dyn_compatibility.rs            |  3 +--
 15 files changed, 44 insertions(+), 40 deletions(-)

diff --git a/compiler/rustc_ast_passes/src/feature_gate.rs b/compiler/rustc_ast_passes/src/feature_gate.rs
index 8cdc7133cc070..bfe7625e85ba2 100644
--- a/compiler/rustc_ast_passes/src/feature_gate.rs
+++ b/compiler/rustc_ast_passes/src/feature_gate.rs
@@ -4,9 +4,9 @@ use rustc_ast::{NodeId, PatKind, attr, token};
 use rustc_feature::{AttributeGate, BUILTIN_ATTRIBUTE_MAP, BuiltinAttribute, Features, GateIssue};
 use rustc_session::Session;
 use rustc_session::parse::{feature_err, feature_err_issue, feature_warn};
+use rustc_span::Span;
 use rustc_span::source_map::Spanned;
-use rustc_span::symbol::sym;
-use rustc_span::{Span, Symbol};
+use rustc_span::symbol::{Symbol, sym};
 use rustc_target::spec::abi;
 use thin_vec::ThinVec;
 
@@ -690,6 +690,7 @@ fn check_new_solver_banned_features(sess: &Session, features: &Features) {
         .find(|feat| feat.gate_name == sym::generic_const_exprs)
         .map(|feat| feat.attr_sp)
     {
+        #[cfg_attr(not(bootstrap), allow(rustc::symbol_intern_string_literal))]
         sess.dcx().emit_err(errors::IncompatibleFeatures {
             spans: vec![gce_span],
             f1: Symbol::intern("-Znext-solver=globally"),
diff --git a/compiler/rustc_borrowck/src/universal_regions.rs b/compiler/rustc_borrowck/src/universal_regions.rs
index f1c23aa26a977..baff654750154 100644
--- a/compiler/rustc_borrowck/src/universal_regions.rs
+++ b/compiler/rustc_borrowck/src/universal_regions.rs
@@ -33,8 +33,8 @@ use rustc_middle::ty::{
     TyCtxt, TypeVisitableExt,
 };
 use rustc_middle::{bug, span_bug};
+use rustc_span::ErrorGuaranteed;
 use rustc_span::symbol::{kw, sym};
-use rustc_span::{ErrorGuaranteed, Symbol};
 use tracing::{debug, instrument};
 
 use crate::BorrowckInferCtxt;
@@ -524,7 +524,7 @@ impl<'cx, 'tcx> UniversalRegionsBuilder<'cx, 'tcx> {
 
                 let reg_vid = self
                     .infcx
-                    .next_nll_region_var(FR, || RegionCtxt::Free(Symbol::intern("c-variadic")))
+                    .next_nll_region_var(FR, || RegionCtxt::Free(sym::c_dash_variadic))
                     .as_var();
 
                 let region = ty::Region::new_var(self.infcx.tcx, reg_vid);
@@ -540,10 +540,8 @@ impl<'cx, 'tcx> UniversalRegionsBuilder<'cx, 'tcx> {
             }
         }
 
-        let fr_fn_body = self
-            .infcx
-            .next_nll_region_var(FR, || RegionCtxt::Free(Symbol::intern("fn_body")))
-            .as_var();
+        let fr_fn_body =
+            self.infcx.next_nll_region_var(FR, || RegionCtxt::Free(sym::fn_body)).as_var();
 
         let num_universals = self.infcx.num_region_vars();
 
diff --git a/compiler/rustc_codegen_cranelift/src/driver/jit.rs b/compiler/rustc_codegen_cranelift/src/driver/jit.rs
index 0d62a13b4724e..ae9578eeffb61 100644
--- a/compiler/rustc_codegen_cranelift/src/driver/jit.rs
+++ b/compiler/rustc_codegen_cranelift/src/driver/jit.rs
@@ -74,7 +74,7 @@ fn create_jit_module(
     jit_builder.symbol("__clif_jit_fn", clif_jit_fn as *const u8);
     let mut jit_module = UnwindModule::new(JITModule::new(jit_builder), false);
 
-    let cx = crate::CodegenCx::new(tcx, jit_module.isa(), false, Symbol::intern("dummy_cgu_name"));
+    let cx = crate::CodegenCx::new(tcx, jit_module.isa(), false, sym::dummy_cgu_name);
 
     crate::allocator::codegen(tcx, &mut jit_module);
 
@@ -276,12 +276,7 @@ fn jit_fn(instance_ptr: *const Instance<'static>, trampoline_ptr: *const u8) ->
 
             jit_module.module.prepare_for_function_redefine(func_id).unwrap();
 
-            let mut cx = crate::CodegenCx::new(
-                tcx,
-                jit_module.isa(),
-                false,
-                Symbol::intern("dummy_cgu_name"),
-            );
+            let mut cx = crate::CodegenCx::new(tcx, jit_module.isa(), false, sym::dummy_cgu_name);
             codegen_and_compile_fn(tcx, &mut cx, &mut Context::new(), jit_module, instance);
 
             assert!(cx.global_asm.is_empty());
diff --git a/compiler/rustc_codegen_cranelift/src/lib.rs b/compiler/rustc_codegen_cranelift/src/lib.rs
index e6f6ae305816f..cac9975f04ce2 100644
--- a/compiler/rustc_codegen_cranelift/src/lib.rs
+++ b/compiler/rustc_codegen_cranelift/src/lib.rs
@@ -189,18 +189,13 @@ impl CodegenBackend for CraneliftCodegenBackend {
         // FIXME return the actually used target features. this is necessary for #[cfg(target_feature)]
         if sess.target.arch == "x86_64" && sess.target.os != "none" {
             // x86_64 mandates SSE2 support
-            vec![Symbol::intern("fxsr"), sym::sse, Symbol::intern("sse2")]
+            vec![sym::fsxr, sym::sse, sym::sse2]
         } else if sess.target.arch == "aarch64" {
             match &*sess.target.os {
                 "none" => vec![],
                 // On macOS the aes, sha2 and sha3 features are enabled by default and ring
                 // fails to compile on macOS when they are not present.
-                "macos" => vec![
-                    sym::neon,
-                    Symbol::intern("aes"),
-                    Symbol::intern("sha2"),
-                    Symbol::intern("sha3"),
-                ],
+                "macos" => vec![sym::neon, sym::aes, sym::sha2, sym::sha3],
                 // AArch64 mandates Neon support
                 _ => vec![sym::neon],
             }
diff --git a/compiler/rustc_hir_analysis/src/collect/generics_of.rs b/compiler/rustc_hir_analysis/src/collect/generics_of.rs
index c31bff28fd34b..7ea58d5e8b2c4 100644
--- a/compiler/rustc_hir_analysis/src/collect/generics_of.rs
+++ b/compiler/rustc_hir_analysis/src/collect/generics_of.rs
@@ -419,7 +419,7 @@ pub(super) fn generics_of(tcx: TyCtxt<'_>, def_id: LocalDefId) -> ty::Generics {
     if let Node::ConstBlock(_) = node {
         own_params.push(ty::GenericParamDef {
             index: next_index(),
-            name: Symbol::intern("<const_ty>"),
+            name: rustc_span::sym::lt_const_underscore_ty_rt,
             def_id: def_id.to_def_id(),
             pure_wrt_drop: false,
             kind: ty::GenericParamDefKind::Type { has_default: false, synthetic: false },
diff --git a/compiler/rustc_hir_typeck/src/method/suggest.rs b/compiler/rustc_hir_typeck/src/method/suggest.rs
index cff2aa6899390..6b1a288510ac1 100644
--- a/compiler/rustc_hir_typeck/src/method/suggest.rs
+++ b/compiler/rustc_hir_typeck/src/method/suggest.rs
@@ -664,7 +664,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
         let is_write = sugg_span.ctxt().outer_expn_data().macro_def_id.is_some_and(|def_id| {
             tcx.is_diagnostic_item(sym::write_macro, def_id)
                 || tcx.is_diagnostic_item(sym::writeln_macro, def_id)
-        }) && item_name.name == Symbol::intern("write_fmt");
+        }) && item_name.name == sym::write_fmt;
         let mut err = if is_write && let SelfSource::MethodCall(rcvr_expr) = source {
             self.suggest_missing_writer(rcvr_ty, rcvr_expr)
         } else {
diff --git a/compiler/rustc_lint/src/unused.rs b/compiler/rustc_lint/src/unused.rs
index e1a0e1ec5791d..b775cd3740911 100644
--- a/compiler/rustc_lint/src/unused.rs
+++ b/compiler/rustc_lint/src/unused.rs
@@ -1563,7 +1563,7 @@ impl UnusedImportBraces {
                     }
                     rename.unwrap_or(orig_ident).name
                 }
-                ast::UseTreeKind::Glob => Symbol::intern("*"),
+                ast::UseTreeKind::Glob => sym::asterisk,
                 ast::UseTreeKind::Nested { .. } => return,
             };
 
diff --git a/compiler/rustc_metadata/src/creader.rs b/compiler/rustc_metadata/src/creader.rs
index a18c6baec00f2..94310d2cad176 100644
--- a/compiler/rustc_metadata/src/creader.rs
+++ b/compiler/rustc_metadata/src/creader.rs
@@ -862,7 +862,7 @@ impl<'a, 'tcx> CrateLoader<'a, 'tcx> {
         // and see what's a global allocator, including if we ourselves are a
         // global allocator.
         let mut global_allocator =
-            self.cstore.has_global_allocator.then(|| Symbol::intern("this crate"));
+            self.cstore.has_global_allocator.then_some(sym::this_space_crate);
         for (_, data) in self.cstore.iter_crate_data() {
             if data.has_global_allocator() {
                 match global_allocator {
@@ -877,7 +877,7 @@ impl<'a, 'tcx> CrateLoader<'a, 'tcx> {
             }
         }
         let mut alloc_error_handler =
-            self.cstore.has_alloc_error_handler.then(|| Symbol::intern("this crate"));
+            self.cstore.has_alloc_error_handler.then_some(sym::this_space_crate);
         for (_, data) in self.cstore.iter_crate_data() {
             if data.has_alloc_error_handler() {
                 match alloc_error_handler {
diff --git a/compiler/rustc_metadata/src/rmeta/decoder.rs b/compiler/rustc_metadata/src/rmeta/decoder.rs
index 56beff5aa6425..93142c88b5bfb 100644
--- a/compiler/rustc_metadata/src/rmeta/decoder.rs
+++ b/compiler/rustc_metadata/src/rmeta/decoder.rs
@@ -875,11 +875,9 @@ impl MetadataBlob {
                         let def_name = if item == CRATE_DEF_INDEX {
                             rustc_span::symbol::kw::Crate
                         } else {
-                            def_key
-                                .disambiguated_data
-                                .data
-                                .get_opt_name()
-                                .unwrap_or_else(|| Symbol::intern("???"))
+                            def_key.disambiguated_data.data.get_opt_name().unwrap_or(
+                                rustc_span::sym::question_mark_question_mark_question_mark,
+                            )
                         };
                         let visibility =
                             root.tables.visibility.get(blob, item).unwrap().decode(blob).map_id(
diff --git a/compiler/rustc_parse/src/parser/ty.rs b/compiler/rustc_parse/src/parser/ty.rs
index c561ea3823d09..4ddf791f70b15 100644
--- a/compiler/rustc_parse/src/parser/ty.rs
+++ b/compiler/rustc_parse/src/parser/ty.rs
@@ -9,7 +9,7 @@ use rustc_ast::{
 };
 use rustc_errors::{Applicability, PResult};
 use rustc_span::symbol::{Ident, kw, sym};
-use rustc_span::{ErrorGuaranteed, Span, Symbol};
+use rustc_span::{ErrorGuaranteed, Span};
 use thin_vec::{ThinVec, thin_vec};
 
 use super::{Parser, PathStyle, SeqSep, TokenType, Trailing};
@@ -1139,7 +1139,7 @@ impl<'a> Parser<'a> {
                 Some(ast::Path {
                     span: fn_token_span.to(self.prev_token.span),
                     segments: thin_vec![ast::PathSegment {
-                        ident: Ident::new(Symbol::intern("Fn"), fn_token_span),
+                        ident: Ident::new(sym::Fn, fn_token_span),
                         id: DUMMY_NODE_ID,
                         args: Some(P(ast::GenericArgs::Parenthesized(ast::ParenthesizedArgs {
                             span: args_lo.to(self.prev_token.span),
diff --git a/compiler/rustc_resolve/src/late/diagnostics.rs b/compiler/rustc_resolve/src/late/diagnostics.rs
index 663c3ac0045ab..ef929c6585efc 100644
--- a/compiler/rustc_resolve/src/late/diagnostics.rs
+++ b/compiler/rustc_resolve/src/late/diagnostics.rs
@@ -3114,9 +3114,9 @@ impl<'ast, 'ra: 'ast, 'tcx> LateResolutionVisitor<'_, 'ast, 'ra, 'tcx> {
         }
 
         let existing_name = match &in_scope_lifetimes[..] {
-            [] => Symbol::intern("'a"),
+            [] => sym::apostrophe_a,
             [(existing, _)] => existing.name,
-            _ => Symbol::intern("'lifetime"),
+            _ => sym::apostrophe_lifetime,
         };
 
         let mut spans_suggs: Vec<_> = Vec::new();
diff --git a/compiler/rustc_resolve/src/lib.rs b/compiler/rustc_resolve/src/lib.rs
index e382295b8f6d8..bd0315a15c216 100644
--- a/compiler/rustc_resolve/src/lib.rs
+++ b/compiler/rustc_resolve/src/lib.rs
@@ -2270,7 +2270,7 @@ fn module_to_string(module: Module<'_>) -> Option<String> {
                 collect_mod(names, parent);
             }
         } else {
-            names.push(Symbol::intern("<opaque>"));
+            names.push(sym::lt_opaque_gt);
             collect_mod(names, module.parent.unwrap());
         }
     }
diff --git a/compiler/rustc_session/src/output.rs b/compiler/rustc_session/src/output.rs
index 357d746c1846f..2b2ba50d3fb77 100644
--- a/compiler/rustc_session/src/output.rs
+++ b/compiler/rustc_session/src/output.rs
@@ -87,7 +87,7 @@ pub fn find_crate_name(sess: &Session, attrs: &[ast::Attribute]) -> Symbol {
         }
     }
 
-    Symbol::intern("rust_out")
+    sym::rust_out
 }
 
 pub fn validate_crate_name(sess: &Session, s: Symbol, sp: Option<Span>) {
diff --git a/compiler/rustc_span/src/symbol.rs b/compiler/rustc_span/src/symbol.rs
index bbbfb51b07835..5ce9bee14db0a 100644
--- a/compiler/rustc_span/src/symbol.rs
+++ b/compiler/rustc_span/src/symbol.rs
@@ -297,6 +297,7 @@ symbols! {
         Return,
         Right,
         Rust,
+        RustaceansAreAwesome,
         RustcDecodable,
         RustcEncodable,
         RwLock,
@@ -377,6 +378,7 @@ symbols! {
         adt_const_params,
         advanced_slice_patterns,
         adx_target_feature,
+        aes,
         aggregate_raw_ptr,
         alias,
         align,
@@ -401,6 +403,8 @@ symbols! {
         anon_adt,
         anonymous_lifetime_in_impl_trait,
         any,
+        apostrophe_a: "'a",
+        apostrophe_lifetime: "'lifetime",
         append_const_msg,
         arbitrary_enum_discriminant,
         arbitrary_self_types,
@@ -439,6 +443,7 @@ symbols! {
         associated_types,
         assume,
         assume_init,
+        asterisk: "*",
         async_await,
         async_call,
         async_call_mut,
@@ -519,6 +524,7 @@ symbols! {
         btreeset_iter,
         builtin_syntax,
         c,
+        c_dash_variadic,
         c_str,
         c_str_literals,
         c_unwind,
@@ -778,6 +784,7 @@ symbols! {
         drop_types_in_const,
         dropck_eyepatch,
         dropck_parametricity,
+        dummy_cgu_name,
         dylib,
         dyn_compatible_for_dispatch,
         dyn_metadata,
@@ -921,6 +928,7 @@ symbols! {
         fmuladdf32,
         fmuladdf64,
         fn_align,
+        fn_body,
         fn_delegation,
         fn_must_use,
         fn_mut,
@@ -961,6 +969,7 @@ symbols! {
         fs_create_dir,
         fsub_algebraic,
         fsub_fast,
+        fsxr,
         full,
         fundamental,
         fused_iterator,
@@ -1176,6 +1185,8 @@ symbols! {
         loongarch_target_feature,
         loop_break_value,
         lt,
+        lt_const_underscore_ty_rt: "<const_ty>",
+        lt_opaque_gt: "<opaque>",
         macro_at_most_once_rep,
         macro_attributes_in_derive_output,
         macro_escape,
@@ -1558,6 +1569,7 @@ symbols! {
         qreg_low8,
         quad_precision_float,
         question_mark,
+        question_mark_question_mark_question_mark: "???",
         quote,
         range_inclusive_new,
         raw_dylib,
@@ -1652,6 +1664,7 @@ symbols! {
         rust_eh_catch_typeinfo,
         rust_eh_personality,
         rust_logo,
+        rust_out,
         rustc,
         rustc_abi,
         rustc_allocator,
@@ -1774,6 +1787,8 @@ symbols! {
         self_in_typedefs,
         self_struct_ctor,
         semitransparent,
+        sha2,
+        sha3,
         sha512_sm_x86,
         shadow_call_stack,
         shallow,
@@ -1887,6 +1902,7 @@ symbols! {
         sreg,
         sreg_low16,
         sse,
+        sse2,
         sse4a_target_feature,
         stable,
         staged_api,
@@ -1966,6 +1982,7 @@ symbols! {
         test_removed_feature,
         test_runner,
         test_unstable_lint,
+        this_space_crate: "this crate",
         thread,
         thread_local,
         thread_local_macro,
@@ -2173,6 +2190,7 @@ symbols! {
         wrapping_sub,
         wreg,
         write_bytes,
+        write_fmt,
         write_macro,
         write_str,
         write_via_move,
diff --git a/compiler/rustc_trait_selection/src/traits/dyn_compatibility.rs b/compiler/rustc_trait_selection/src/traits/dyn_compatibility.rs
index e0a9ddf1876e6..993bc2e9b9407 100644
--- a/compiler/rustc_trait_selection/src/traits/dyn_compatibility.rs
+++ b/compiler/rustc_trait_selection/src/traits/dyn_compatibility.rs
@@ -18,7 +18,6 @@ use rustc_middle::ty::{
     TypeVisitableExt, TypeVisitor, TypingMode, Upcast,
 };
 use rustc_span::Span;
-use rustc_span::symbol::Symbol;
 use smallvec::SmallVec;
 use tracing::{debug, instrument};
 
@@ -679,7 +678,7 @@ fn receiver_is_dispatchable<'tcx>(
     // FIXME(mikeyhew) this is a total hack. Once dyn_compatible_for_dispatch is stabilized, we can
     // replace this with `dyn Trait`
     let unsized_self_ty: Ty<'tcx> =
-        Ty::new_param(tcx, u32::MAX, Symbol::intern("RustaceansAreAwesome"));
+        Ty::new_param(tcx, u32::MAX, rustc_span::sym::RustaceansAreAwesome);
 
     // `Receiver[Self => U]`
     let unsized_receiver_ty =