linker: Avoid calling linker_and_flavor twice

Author: petrochenkov

compiler/rustc_codegen_ssa/src/back/link.rs

@@ -670,7 +670,7 @@ fn link_natively(
 ) {
     info!("preparing {:?} to {:?}", crate_type, out_filename);
     let (linker_path, flavor) = linker_and_flavor(sess);
-    let self_contained_components = self_contained_components(sess, crate_type);
+    let self_contained_components = self_contained_components(sess, crate_type, &linker_path);
 
     // On AIX, we ship all libraries as .a big_af archive
     // the expected format is lib<name>.a(libname.so) for the actual
@@ -1788,16 +1788,15 @@ fn link_output_kind(sess: &Session, crate_type: CrateType) -> LinkOutputKind {
 }
 
 // Returns true if linker is located within sysroot
-fn detect_self_contained_mingw(sess: &Session) -> bool {
-    let (linker, _) = linker_and_flavor(sess);
+fn detect_self_contained_mingw(sess: &Session, linker: &Path) -> bool {
     // Assume `-C linker=rust-lld` as self-contained mode
     if linker == Path::new("rust-lld") {
         return true;
     }
     let linker_with_extension = if cfg!(windows) && linker.extension().is_none() {
         linker.with_extension("exe")
     } else {
-        linker
+        linker.to_path_buf()
     };
     for dir in env::split_paths(&env::var_os("PATH").unwrap_or_default()) {
         let full_path = dir.join(&linker_with_extension);
@@ -1812,7 +1811,11 @@ fn detect_self_contained_mingw(sess: &Session) -> bool {
 /// Various toolchain components used during linking are used from rustc distribution
 /// instead of being found somewhere on the host system.
 /// We only provide such support for a very limited number of targets.
-fn self_contained_components(sess: &Session, crate_type: CrateType) -> LinkSelfContainedComponents {
+fn self_contained_components(
+    sess: &Session,
+    crate_type: CrateType,
+    linker: &Path,
+) -> LinkSelfContainedComponents {
     // Turn the backwards compatible bool values for `self_contained` into fully inferred
     // `LinkSelfContainedComponents`.
     let self_contained =
@@ -1841,7 +1844,7 @@ fn self_contained_components(sess: &Session, crate_type: CrateType) -> LinkSelfC
                 LinkSelfContainedDefault::InferredForMingw => {
                     sess.host == sess.target
                         && sess.target.vendor != "uwp"
-                        && detect_self_contained_mingw(sess)
+                        && detect_self_contained_mingw(sess, linker)
                 }
             }
         };