Reduce usage of Symbol in the linker code

Interning here doesn't save us anything. It rather costs a bit of time.

compiler/rustc_codegen_ssa/src/back/archive.rs

@@ -1,13 +1,12 @@
 use rustc_data_structures::temp_dir::MaybeTempDir;
 use rustc_session::cstore::DllImport;
 use rustc_session::Session;
-use rustc_span::symbol::Symbol;
 
 use std::io;
 use std::path::{Path, PathBuf};
 
 pub(super) fn find_library(
-    name: Symbol,
+    name: &str,
     verbatim: bool,
     search_paths: &[PathBuf],
     sess: &Session,

compiler/rustc_codegen_ssa/src/back/command.rs

@@ -7,7 +7,6 @@ use std::io;
 use std::mem;
 use std::process::{self, Output};
 
-use rustc_span::symbol::Symbol;
 use rustc_target::spec::LldFlavor;
 
 #[derive(Clone)]
@@ -47,11 +46,6 @@ impl Command {
         self
     }
 
-    pub fn sym_arg(&mut self, arg: Symbol) -> &mut Command {
-        self.arg(arg.as_str());
-        self
-    }
-
     pub fn args<I>(&mut self, args: I) -> &mut Command
     where
         I: IntoIterator<Item: AsRef<OsStr>>,

compiler/rustc_codegen_ssa/src/back/link.rs

@@ -354,7 +354,7 @@ fn link_rlib<'a, B: ArchiveBuilder<'a>>(
         }
         if let Some(name) = lib.name {
             let location =
-                find_library(name, lib.verbatim.unwrap_or(false), &lib_search_paths, sess);
+                find_library(name.as_str(), lib.verbatim.unwrap_or(false), &lib_search_paths, sess);
             ab.add_archive(&location, |_| false).unwrap_or_else(|e| {
                 sess.fatal(&format!(
                     "failed to add native library {}: {}",
@@ -1117,7 +1117,7 @@ fn link_sanitizer_runtime(sess: &Session, linker: &mut dyn Linker, name: &str) {
         let path = find_sanitizer_runtime(&sess, &filename);
         let rpath = path.to_str().expect("non-utf8 component in path");
         linker.args(&["-Wl,-rpath", "-Xlinker", rpath]);
-        linker.link_dylib(Symbol::intern(&filename), false, true);
+        linker.link_dylib(&filename, false, true);
     } else {
         let filename = format!("librustc{}_rt.{}.a", channel, name);
         let path = find_sanitizer_runtime(&sess, &filename).join(&filename);
@@ -2199,6 +2199,7 @@ fn add_local_native_libraries(
         let Some(name) = lib.name else {
             continue;
         };
+        let name = name.as_str();
 
         // Skip if this library is the same as the last.
         last = if (lib.name, lib.kind, lib.verbatim) == last {
@@ -2362,6 +2363,7 @@ fn add_upstream_rust_crates<'a, B: ArchiveBuilder<'a>>(
                         let Some(name) = lib.name else {
                             continue;
                         };
+                        let name = name.as_str();
                         if !relevant_lib(sess, lib) {
                             continue;
                         }
@@ -2519,7 +2521,7 @@ fn add_upstream_rust_crates<'a, B: ArchiveBuilder<'a>>(
         }
         let filestem = cratepath.file_stem().unwrap().to_str().unwrap();
         cmd.link_rust_dylib(
-            Symbol::intern(&unlib(&sess.target, filestem)),
+            &unlib(&sess.target, filestem),
             parent.unwrap_or_else(|| Path::new("")),
         );
     }
@@ -2551,6 +2553,7 @@ fn add_upstream_native_libraries(
             let Some(name) = lib.name else {
                 continue;
             };
+            let name = name.as_str();
             if !relevant_lib(sess, &lib) {
                 continue;
             }

compiler/rustc_codegen_ssa/src/back/linker.rs

@@ -16,7 +16,6 @@ use rustc_middle::middle::exported_symbols::{ExportedSymbol, SymbolExportInfo, S
 use rustc_middle::ty::TyCtxt;
 use rustc_session::config::{self, CrateType, DebugInfo, LinkerPluginLto, Lto, OptLevel, Strip};
 use rustc_session::Session;
-use rustc_span::symbol::Symbol;
 use rustc_target::spec::{LinkOutputKind, LinkerFlavor, LldFlavor};
 
 use cc::windows_registry;
@@ -163,13 +162,13 @@ pub fn get_linker<'a>(
 pub trait Linker {
     fn cmd(&mut self) -> &mut Command;
     fn set_output_kind(&mut self, output_kind: LinkOutputKind, out_filename: &Path);
-    fn link_dylib(&mut self, lib: Symbol, verbatim: bool, as_needed: bool);
+    fn link_dylib(&mut self, lib: &str, verbatim: bool, as_needed: bool);
-    fn link_rust_dylib(&mut self, lib: Symbol, path: &Path);
+    fn link_rust_dylib(&mut self, lib: &str, path: &Path);
-    fn link_framework(&mut self, framework: Symbol, as_needed: bool);
+    fn link_framework(&mut self, framework: &str, as_needed: bool);
-    fn link_staticlib(&mut self, lib: Symbol, verbatim: bool);
+    fn link_staticlib(&mut self, lib: &str, verbatim: bool);
     fn link_rlib(&mut self, lib: &Path);
     fn link_whole_rlib(&mut self, lib: &Path);
-    fn link_whole_staticlib(&mut self, lib: Symbol, verbatim: bool, search_path: &[PathBuf]);
+    fn link_whole_staticlib(&mut self, lib: &str, verbatim: bool, search_path: &[PathBuf]);
     fn include_path(&mut self, path: &Path);
     fn framework_path(&mut self, path: &Path);
     fn output_filename(&mut self, path: &Path);
@@ -423,8 +422,8 @@ impl<'a> Linker for GccLinker<'a> {
         }
     }
 
-    fn link_dylib(&mut self, lib: Symbol, verbatim: bool, as_needed: bool) {
+    fn link_dylib(&mut self, lib: &str, verbatim: bool, as_needed: bool) {
-        if self.sess.target.os == "illumos" && lib.as_str() == "c" {
+        if self.sess.target.os == "illumos" && lib == "c" {
             // libc will be added via late_link_args on illumos so that it will
             // appear last in the library search order.
             // FIXME: This should be replaced by a more complete and generic
@@ -454,7 +453,7 @@ impl<'a> Linker for GccLinker<'a> {
             }
         }
     }
-    fn link_staticlib(&mut self, lib: Symbol, verbatim: bool) {
+    fn link_staticlib(&mut self, lib: &str, verbatim: bool) {
         self.hint_static();
         self.cmd.arg(format!("-l{}{}", if verbatim { ":" } else { "" }, lib));
     }
@@ -484,20 +483,20 @@ impl<'a> Linker for GccLinker<'a> {
         self.linker_arg("-znorelro");
     }
 
-    fn link_rust_dylib(&mut self, lib: Symbol, _path: &Path) {
+    fn link_rust_dylib(&mut self, lib: &str, _path: &Path) {
         self.hint_dynamic();
         self.cmd.arg(format!("-l{}", lib));
     }
 
-    fn link_framework(&mut self, framework: Symbol, as_needed: bool) {
+    fn link_framework(&mut self, framework: &str, as_needed: bool) {
         self.hint_dynamic();
         if !as_needed {
             // FIXME(81490): ld64 as of macOS 11 supports the -needed_framework
             // flag but we have no way to detect that here.
-            // self.cmd.arg("-needed_framework").sym_arg(framework);
+            // self.cmd.arg("-needed_framework").arg(framework);
             self.sess.warn("`as-needed` modifier not implemented yet for ld64");
         }
-        self.cmd.arg("-framework").sym_arg(framework);
+        self.cmd.arg("-framework").arg(framework);
     }
 
     // Here we explicitly ask that the entire archive is included into the
@@ -506,7 +505,7 @@ impl<'a> Linker for GccLinker<'a> {
     // don't otherwise explicitly reference them. This can occur for
     // libraries which are just providing bindings, libraries with generic
     // functions, etc.
-    fn link_whole_staticlib(&mut self, lib: Symbol, verbatim: bool, search_path: &[PathBuf]) {
+    fn link_whole_staticlib(&mut self, lib: &str, verbatim: bool, search_path: &[PathBuf]) {
         self.hint_static();
         let target = &self.sess.target;
         if !target.is_like_osx {
@@ -836,11 +835,11 @@ impl<'a> Linker for MsvcLinker<'a> {
         self.cmd.arg("/OPT:NOREF,NOICF");
     }
 
-    fn link_dylib(&mut self, lib: Symbol, verbatim: bool, _as_needed: bool) {
+    fn link_dylib(&mut self, lib: &str, verbatim: bool, _as_needed: bool) {
         self.cmd.arg(format!("{}{}", lib, if verbatim { "" } else { ".lib" }));
     }
 
-    fn link_rust_dylib(&mut self, lib: Symbol, path: &Path) {
+    fn link_rust_dylib(&mut self, lib: &str, path: &Path) {
         // When producing a dll, the MSVC linker may not actually emit a
         // `foo.lib` file if the dll doesn't actually export any symbols, so we
         // check to see if the file is there and just omit linking to it if it's
@@ -851,7 +850,7 @@ impl<'a> Linker for MsvcLinker<'a> {
         }
     }
 
-    fn link_staticlib(&mut self, lib: Symbol, verbatim: bool) {
+    fn link_staticlib(&mut self, lib: &str, verbatim: bool) {
         self.cmd.arg(format!("{}{}", lib, if verbatim { "" } else { ".lib" }));
     }
 
@@ -890,11 +889,11 @@ impl<'a> Linker for MsvcLinker<'a> {
     fn framework_path(&mut self, _path: &Path) {
         bug!("frameworks are not supported on windows")
     }
-    fn link_framework(&mut self, _framework: Symbol, _as_needed: bool) {
+    fn link_framework(&mut self, _framework: &str, _as_needed: bool) {
         bug!("frameworks are not supported on windows")
     }
 
-    fn link_whole_staticlib(&mut self, lib: Symbol, verbatim: bool, _search_path: &[PathBuf]) {
+    fn link_whole_staticlib(&mut self, lib: &str, verbatim: bool, _search_path: &[PathBuf]) {
         self.cmd.arg(format!("/WHOLEARCHIVE:{}{}", lib, if verbatim { "" } else { ".lib" }));
     }
     fn link_whole_rlib(&mut self, path: &Path) {
@@ -1047,8 +1046,8 @@ impl<'a> Linker for EmLinker<'a> {
         self.cmd.arg("-L").arg(path);
     }
 
-    fn link_staticlib(&mut self, lib: Symbol, _verbatim: bool) {
+    fn link_staticlib(&mut self, lib: &str, _verbatim: bool) {
-        self.cmd.arg("-l").sym_arg(lib);
+        self.cmd.arg("-l").arg(lib);
     }
 
     fn output_filename(&mut self, path: &Path) {
@@ -1059,12 +1058,12 @@ impl<'a> Linker for EmLinker<'a> {
         self.cmd.arg(path);
     }
 
-    fn link_dylib(&mut self, lib: Symbol, verbatim: bool, _as_needed: bool) {
+    fn link_dylib(&mut self, lib: &str, verbatim: bool, _as_needed: bool) {
         // Emscripten always links statically
         self.link_staticlib(lib, verbatim);
     }
 
-    fn link_whole_staticlib(&mut self, lib: Symbol, verbatim: bool, _search_path: &[PathBuf]) {
+    fn link_whole_staticlib(&mut self, lib: &str, verbatim: bool, _search_path: &[PathBuf]) {
         // not supported?
         self.link_staticlib(lib, verbatim);
     }
@@ -1074,7 +1073,7 @@ impl<'a> Linker for EmLinker<'a> {
         self.link_rlib(lib);
     }
 
-    fn link_rust_dylib(&mut self, lib: Symbol, _path: &Path) {
+    fn link_rust_dylib(&mut self, lib: &str, _path: &Path) {
         self.link_dylib(lib, false, true);
     }
 
@@ -1098,7 +1097,7 @@ impl<'a> Linker for EmLinker<'a> {
         bug!("frameworks are not supported on Emscripten")
     }
 
-    fn link_framework(&mut self, _framework: Symbol, _as_needed: bool) {
+    fn link_framework(&mut self, _framework: &str, _as_needed: bool) {
         bug!("frameworks are not supported on Emscripten")
     }
 
@@ -1237,12 +1236,12 @@ impl<'a> Linker for WasmLd<'a> {
         }
     }
 
-    fn link_dylib(&mut self, lib: Symbol, _verbatim: bool, _as_needed: bool) {
+    fn link_dylib(&mut self, lib: &str, _verbatim: bool, _as_needed: bool) {
-        self.cmd.arg("-l").sym_arg(lib);
+        self.cmd.arg("-l").arg(lib);
     }
 
-    fn link_staticlib(&mut self, lib: Symbol, _verbatim: bool) {
+    fn link_staticlib(&mut self, lib: &str, _verbatim: bool) {
-        self.cmd.arg("-l").sym_arg(lib);
+        self.cmd.arg("-l").arg(lib);
     }
 
     fn link_rlib(&mut self, lib: &Path) {
@@ -1271,16 +1270,16 @@ impl<'a> Linker for WasmLd<'a> {
 
     fn no_relro(&mut self) {}
 
-    fn link_rust_dylib(&mut self, lib: Symbol, _path: &Path) {
+    fn link_rust_dylib(&mut self, lib: &str, _path: &Path) {
-        self.cmd.arg("-l").sym_arg(lib);
+        self.cmd.arg("-l").arg(lib);
     }
 
-    fn link_framework(&mut self, _framework: Symbol, _as_needed: bool) {
+    fn link_framework(&mut self, _framework: &str, _as_needed: bool) {
         panic!("frameworks not supported")
     }
 
-    fn link_whole_staticlib(&mut self, lib: Symbol, _verbatim: bool, _search_path: &[PathBuf]) {
+    fn link_whole_staticlib(&mut self, lib: &str, _verbatim: bool, _search_path: &[PathBuf]) {
-        self.cmd.arg("-l").sym_arg(lib);
+        self.cmd.arg("-l").arg(lib);
     }
 
     fn link_whole_rlib(&mut self, lib: &Path) {
@@ -1360,10 +1359,10 @@ pub struct L4Bender<'a> {
 }
 
 impl<'a> Linker for L4Bender<'a> {
-    fn link_dylib(&mut self, _lib: Symbol, _verbatim: bool, _as_needed: bool) {
+    fn link_dylib(&mut self, _lib: &str, _verbatim: bool, _as_needed: bool) {
         bug!("dylibs are not supported on L4Re");
     }
-    fn link_staticlib(&mut self, lib: Symbol, _verbatim: bool) {
+    fn link_staticlib(&mut self, lib: &str, _verbatim: bool) {
         self.hint_static();
         self.cmd.arg(format!("-PC{}", lib));
     }
@@ -1404,15 +1403,15 @@ impl<'a> Linker for L4Bender<'a> {
 
     fn set_output_kind(&mut self, _output_kind: LinkOutputKind, _out_filename: &Path) {}
 
-    fn link_rust_dylib(&mut self, _: Symbol, _: &Path) {
+    fn link_rust_dylib(&mut self, _: &str, _: &Path) {
         panic!("Rust dylibs not supported");
     }
 
-    fn link_framework(&mut self, _framework: Symbol, _as_needed: bool) {
+    fn link_framework(&mut self, _framework: &str, _as_needed: bool) {
         bug!("frameworks not supported on L4Re");
     }
 
-    fn link_whole_staticlib(&mut self, lib: Symbol, _verbatim: bool, _search_path: &[PathBuf]) {
+    fn link_whole_staticlib(&mut self, lib: &str, _verbatim: bool, _search_path: &[PathBuf]) {
         self.hint_static();
         self.cmd.arg("--whole-archive").arg(format!("-l{}", lib));
         self.cmd.arg("--no-whole-archive");
@@ -1617,19 +1616,19 @@ impl<'a> Linker for PtxLinker<'a> {
         self.cmd.arg("-o").arg(path);
     }
 
-    fn link_dylib(&mut self, _lib: Symbol, _verbatim: bool, _as_needed: bool) {
+    fn link_dylib(&mut self, _lib: &str, _verbatim: bool, _as_needed: bool) {
         panic!("external dylibs not supported")
     }
 
-    fn link_rust_dylib(&mut self, _lib: Symbol, _path: &Path) {
+    fn link_rust_dylib(&mut self, _lib: &str, _path: &Path) {
         panic!("external dylibs not supported")
     }
 
-    fn link_staticlib(&mut self, _lib: Symbol, _verbatim: bool) {
+    fn link_staticlib(&mut self, _lib: &str, _verbatim: bool) {
         panic!("staticlibs not supported")
     }
 
-    fn link_whole_staticlib(&mut self, _lib: Symbol, _verbatim: bool, _search_path: &[PathBuf]) {
+    fn link_whole_staticlib(&mut self, _lib: &str, _verbatim: bool, _search_path: &[PathBuf]) {
         panic!("staticlibs not supported")
     }
 
@@ -1637,7 +1636,7 @@ impl<'a> Linker for PtxLinker<'a> {
         panic!("frameworks not supported")
     }
 
-    fn link_framework(&mut self, _framework: Symbol, _as_needed: bool) {
+    fn link_framework(&mut self, _framework: &str, _as_needed: bool) {
         panic!("frameworks not supported")
     }
 
@@ -1717,19 +1716,19 @@ impl<'a> Linker for BpfLinker<'a> {
         self.cmd.arg("-o").arg(path);
     }
 
-    fn link_dylib(&mut self, _lib: Symbol, _verbatim: bool, _as_needed: bool) {
+    fn link_dylib(&mut self, _lib: &str, _verbatim: bool, _as_needed: bool) {
         panic!("external dylibs not supported")
     }
 
-    fn link_rust_dylib(&mut self, _lib: Symbol, _path: &Path) {
+    fn link_rust_dylib(&mut self, _lib: &str, _path: &Path) {
         panic!("external dylibs not supported")
     }
 
-    fn link_staticlib(&mut self, _lib: Symbol, _verbatim: bool) {
+    fn link_staticlib(&mut self, _lib: &str, _verbatim: bool) {
         panic!("staticlibs not supported")
     }
 
-    fn link_whole_staticlib(&mut self, _lib: Symbol, _verbatim: bool, _search_path: &[PathBuf]) {
+    fn link_whole_staticlib(&mut self, _lib: &str, _verbatim: bool, _search_path: &[PathBuf]) {
         panic!("staticlibs not supported")
     }
 
@@ -1737,7 +1736,7 @@ impl<'a> Linker for BpfLinker<'a> {
         panic!("frameworks not supported")
     }
 
-    fn link_framework(&mut self, _framework: Symbol, _as_needed: bool) {
+    fn link_framework(&mut self, _framework: &str, _as_needed: bool) {
         panic!("frameworks not supported")
     }