rustup: Patch rustup to patchelf binaries

pkgs/development/tools/rust/rustup/0001-dynamically-patchelf-binaries.patch

···
+From c21cc756b69a5f33c8a7758b746a816f40f55932 Mon Sep 17 00:00:00 2001
+From: Leon Isenberg <[e-mail]>
+Date: Sat, 28 Oct 2017 17:58:17 +0200
+Subject: [PATCH] nix customization: patchelf installed binaries
+
+---
+ src/rustup-dist/src/component/package.rs | 24 +++++++++++++++++++++++-
+ 1 file changed, 23 insertions(+), 1 deletion(-)
+
+diff --git a/src/rustup-dist/src/component/package.rs b/src/rustup-dist/src/component/package.rs
+index 8aa63db9..4d219826 100644
+--- a/src/rustup-dist/src/component/package.rs
++++ b/src/rustup-dist/src/component/package.rs
+@@ -99,7 +99,13 @@ impl Package for DirectoryPackage {
+             let src_path = root.join(&path);
+ 
+             match &*part.0 {
+-                "file" => try!(builder.copy_file(path.clone(), &src_path)),
++                "file" => {
++                    try!(builder.copy_file(path.clone(), &src_path));
++                    nix_patchelf_if_needed(
++                        &target.prefix().path().join(path.clone()),
++                        &src_path,
++                    )
++                }
+                 "dir" => try!(builder.copy_dir(path.clone(), &src_path)),
+                 _ => return Err(ErrorKind::CorruptComponent(name.to_owned()).into()),
+             }
+@@ -117,6 +123,22 @@ impl Package for DirectoryPackage {
+     }
+ }
+ 
++fn nix_patchelf_if_needed(dest_path: &Path, src_path: &Path) {
++    let is_bin = if let Some(p) = src_path.parent() {
++        p.ends_with("bin")
++    } else {
++        false
++    };
++
++    if is_bin {
++        let _ = ::std::process::Command::new("@patchelf@/bin/patchelf")
++            .arg("--set-interpreter")
++            .arg("@dynamicLinker@")
++            .arg(dest_path)
++            .output();
++    }
++}
++
+ // On Unix we need to set up the file permissions correctly so
+ // binaries are executable and directories readable. This shouldn't be
+ // necessary: the source files *should* have the right permissions,
+-- 
+2.14.1
+

pkgs/development/tools/rust/rustup/0001-use-hardcoded-dynamic-linker.patch

···
-From 36c053f37670c6003f9e8dc001741f7c49e9526a Mon Sep 17 00:00:00 2001
-From: =?UTF-8?q?J=C3=B6rg=20Thalheim?= <[e-mail]>
-Date: Sat, 15 Apr 2017 20:42:10 +0200
-Subject: [PATCH] use hardcoded dynamic-linker
-MIME-Version: 1.0
-Content-Type: text/plain; charset=UTF-8
-Content-Transfer-Encoding: 8bit
-
-Signed-off-by: Jörg Thalheim <[e-mail]>
----
- src/rustup-cli/common.rs |  3 ++-
- src/rustup/toolchain.rs  | 22 ++++++++++++++++++++--
- 2 files changed, 22 insertions(+), 3 deletions(-)
-
-diff --git a/src/rustup-cli/common.rs b/src/rustup-cli/common.rs
-index 1abf345..21096e7 100644
---- a/src/rustup-cli/common.rs
-+++ b/src/rustup-cli/common.rs
-@@ -220,7 +220,8 @@ pub fn rustc_version(toolchain: &Toolchain) -> String {
-     if toolchain.exists() {
-         let rustc_path = toolchain.binary_file("rustc");
-         if utils::is_file(&rustc_path) {
--            let mut cmd = Command::new(&rustc_path);
-+            let mut cmd = Command::new("@dynamicLinker@");
-+            cmd.arg(&rustc_path);
-             cmd.arg("--version");
-             toolchain.set_ldpath(&mut cmd);
- 
-diff --git a/src/rustup/toolchain.rs b/src/rustup/toolchain.rs
-index dc29c32..212a4ab 100644
---- a/src/rustup/toolchain.rs
-+++ b/src/rustup/toolchain.rs
-@@ -315,7 +315,7 @@ impl<'a> Toolchain<'a> {
-             }
-             Path::new(&binary)
-         };
--        let mut cmd = Command::new(&path);
-+        let mut cmd = wrap_elf_interpreter(&path);
-         self.set_env(&mut cmd);
-         Ok(cmd)
-     }
-@@ -363,7 +363,7 @@ impl<'a> Toolchain<'a> {
-         } else {
-             src_file
-         };
--        let mut cmd = Command::new(exe_path);
-+        let mut cmd = wrap_elf_interpreter(exe_path);
-         self.set_env(&mut cmd);
-         cmd.env("RUSTUP_TOOLCHAIN", &primary_toolchain.name);
-         Ok(cmd)
-@@ -648,3 +648,21 @@ impl<'a> Toolchain<'a> {
-         path
-     }
- }
-+
-+fn wrap_elf_interpreter<S: AsRef<OsStr>>(p: S) -> Command {
-+    use std::fs::File;
-+    use std::io::Read;
-+    let path = Path::new(&p);
-+    let is_elf = File::open(path).map(|mut f| {
-+        let mut buf = [0; 4];
-+        let _ = f.read(&mut buf);
-+        buf == b"\x7fELF"[..]
-+    }).unwrap_or(false);
-+    if is_elf {
-+        let mut cmd = Command::new("@dynamicLinker@");
-+        cmd.arg(&path);
-+        cmd
-+    } else {
-+        Command::new(&path)
-+    }
-+}
--- 
-2.12.2
-

pkgs/development/tools/rust/rustup/default.nix

···
-{ stdenv, lib, runCommand
+{ stdenv, lib, runCommand, patchelf
 , fetchFromGitHub, rustPlatform
 , pkgconfig, curl, Security }:
 
···
   cargoBuildFlags = [ "--features no-self-update" ];
 
   patches = lib.optionals stdenv.isLinux [
-    (runCommand "0001-use-hardcoded-dynamic-linker.patch" { CC=stdenv.cc; } ''
+    (runCommand "0001-dynamically-patchelf-binaries.patch" { CC=stdenv.cc; patchelf = patchelf; } ''
        export dynamicLinker=$(cat $CC/nix-support/dynamic-linker)
-       substituteAll ${./0001-use-hardcoded-dynamic-linker.patch} $out
+       substitute ${./0001-dynamically-patchelf-binaries.patch} $out \
+         --subst-var patchelf \
+         --subst-var dynamicLinker
     '')
   ];