Auto merge of rust-lang#126692 - DianQK:nixos-patchelf, r=Nilstrieb

patch `rust-lld` and `ld.lld` on NixOS

When `rustc` uses its self-contained lld, we also need to patch `rust-lld` and `ld.lld`.
The `rpath` for `rust-lld` is `$ORIGIN/../../../:$ORIGIN/../lib`, so I use `--add-rpath` instead of `--set-rpath`, which should be easier to maintain.

I also changed `src/bootstrap/src/core/download.rs`, even this doesn't fix any known issues.

For the `lld-wrapper.sh` of lld, refer to: rust-lang/rustc-dev-guide#1999.

src/bootstrap/bootstrap.py

@@ -617,6 +617,9 @@ def download_toolchain(self):
                 self.fix_bin_or_dylib("{}/bin/rustdoc".format(bin_root))
                 self.fix_bin_or_dylib("{}/libexec/rust-analyzer-proc-macro-srv".format(bin_root))
                 lib_dir = "{}/lib".format(bin_root)
+                rustlib_bin_dir = "{}/rustlib/{}/bin".format(lib_dir, self.build)
+                self.fix_bin_or_dylib("{}/rust-lld".format(rustlib_bin_dir))
+                self.fix_bin_or_dylib("{}/gcc-ld/ld.lld".format(rustlib_bin_dir))
                 for lib in os.listdir(lib_dir):
                     # .so is not necessarily the suffix, there can be version numbers afterwards.
                     if ".so" in lib:
@@ -731,12 +734,9 @@ def fix_bin_or_dylib(self, fname):
 
         patchelf = "{}/bin/patchelf".format(nix_deps_dir)
         rpath_entries = [
-            # Relative default, all binary and dynamic libraries we ship
-            # appear to have this (even when `../lib` is redundant).
-            "$ORIGIN/../lib",
             os.path.join(os.path.realpath(nix_deps_dir), "lib")
         ]
-        patchelf_args = ["--set-rpath", ":".join(rpath_entries)]
+        patchelf_args = ["--add-rpath", ":".join(rpath_entries)]
         if ".so" not in fname:
             # Finally, set the correct .interp for binaries
             with open("{}/nix-support/dynamic-linker".format(nix_deps_dir)) as dynamic_linker:

src/bootstrap/src/core/download.rs

@@ -173,15 +173,10 @@ impl Config {
         }
 
         let mut patchelf = Command::new(nix_deps_dir.join("bin/patchelf"));
-        let rpath_entries = {
-            // ORIGIN is a relative default, all binary and dynamic libraries we ship
-            // appear to have this (even when `../lib` is redundant).
-            // NOTE: there are only two paths here, delimited by a `:`
-            let mut entries = OsString::from("$ORIGIN/../lib:");
-            entries.push(t!(fs::canonicalize(nix_deps_dir)).join("lib"));
-            entries
-        };
-        patchelf.args(&[OsString::from("--set-rpath"), rpath_entries]);
+        patchelf.args(&[
+            OsString::from("--add-rpath"),
+            OsString::from(t!(fs::canonicalize(nix_deps_dir)).join("lib")),
+        ]);
         if !path_is_dylib(fname) {
             // Finally, set the correct .interp for binaries
             let dynamic_linker_path = nix_deps_dir.join("nix-support/dynamic-linker");