testing/rust: properly force RPATH with a new target option

These patches add a new target option, `need_rpath`, to force RPATH
embedding in appropriate situations. We also minimize the generated
RPATH.

1 files changed, 102 insertions, 0 deletions

diff --git a/testing/rust/minimize-rpath.patch b/testing/rust/minimize-rpath.patch
new file mode 100644
index 00000000000..1fc0e1b722c
--- /dev/null
+++ b/testing/rust/minimize-rpath.patch
@@ -0,0 +1,102 @@
+From: Shiz <hi@shiz.me>
+Date: Thu, 20 Aug 2017 01:44:12 +0200
+Subject: [PATCH] Minimize generated RPATH in end products
+
+By default, RPATH generation adds both the install prefix and the generated
+relative path to the install prefix. This is unnecessary, so we add the install
+prefix to a list of absolute paths to omit in the relative path generation,
+and skip it there.
+
+--- a/src/librustc_trans/back/rpath.rs
++++ b/src/librustc_trans/back/rpath.rs
+@@ -69,14 +69,15 @@
+         debug!("    {:?}", libpath.display());
+     }
+ 
++    // The backup rpath is the global library location.
++    // We also omit this path from the relative rpaths.
++    let fallback_rpaths = vec![get_install_prefix_rpath(config)];
++
+     // Use relative paths to the libraries. Binaries can be moved
+     // as long as they maintain the relative relationship to the
+     // crates they depend on.
+-    let rel_rpaths = get_rpaths_relative_to_output(config, libs);
++    let rel_rpaths = get_rpaths_relative_to_output(config, libs, &fallback_rpaths);
+ 
+-    // And a final backup rpath to the global library location.
+-    let fallback_rpaths = vec![get_install_prefix_rpath(config)];
+-
+     fn log_rpaths(desc: &str, rpaths: &[String]) {
+         debug!("{} rpaths:", desc);
+         for rpath in rpaths {
+@@ -96,11 +97,13 @@
+ }
+ 
+ fn get_rpaths_relative_to_output(config: &mut RPathConfig,
+-                                 libs: &[PathBuf]) -> Vec<String> {
+-    libs.iter().map(|a| get_rpath_relative_to_output(config, a)).collect()
++                                 libs: &[PathBuf],
++                                 omit: &Vec<String>) -> Vec<String> {
++    libs.iter().filter_map(|a| get_rpath_relative_to_output(config, a, omit)).collect()
+ }
+ 
+-fn get_rpath_relative_to_output(config: &mut RPathConfig, lib: &Path) -> String {
++fn get_rpath_relative_to_output(config: &mut RPathConfig, lib: &Path,
++                                omit: &Vec<String>) -> Option<String> {
+     // Mac doesn't appear to support $ORIGIN
+     let prefix = if config.is_like_osx {
+         "@loader_path"
+@@ -114,11 +117,18 @@
+     let mut output = cwd.join(&config.out_filename);
+     output.pop();
+     let output = fs::canonicalize(&output).unwrap_or(output);
+-    let relative = path_relative_from(&lib, &output)
+-        .expect(&format!("couldn't create relative path from {:?} to {:?}", output, lib));
++
+     // FIXME (#9639): This needs to handle non-utf8 paths
+-    format!("{}/{}", prefix,
+-            relative.to_str().expect("non-utf8 component in path"))
++    let libpath = lib.to_str().expect("non-utf8 component in path").to_string();
++    if omit.contains(&libpath) {
++        None
++    } else {
++        let relative = path_relative_from(&lib, &output)
++            .expect(&format!("couldn't create relative path from {:?} to {:?}", output, lib));
++        // FIXME (#9639): This needs to handle non-utf8 paths
++        Some(format!("{}/{}", prefix,
++                     relative.to_str().expect("non-utf8 component in path")))
++    }
+ }
+ 
+ // This routine is adapted from the *old* Path's `path_relative_from`
+@@ -239,6 +249,7 @@
+     #[test]
+     fn test_rpath_relative() {
+         if cfg!(target_os = "macos") {
++            let omit = Vec::new();
+             let config = &mut RPathConfig {
+                 used_crates: Vec::new(),
+                 has_rpath: true,
+@@ -248,9 +259,11 @@
+                 get_install_prefix_lib_path: &mut || panic!(),
+             };
+             let res = get_rpath_relative_to_output(config,
+-                                                   Path::new("lib/libstd.so"));
++                                                   Path::new("lib/libstd.so"),
++                                                   &omit);
+             assert_eq!(res, "@loader_path/../lib");
+         } else {
++            let omit = Vec::new();
+             let config = &mut RPathConfig {
+                 used_crates: Vec::new(),
+                 out_filename: PathBuf::from("bin/rustc"),
+@@ -260,7 +273,8 @@
+                 linker_is_gnu: true,
+             };
+             let res = get_rpath_relative_to_output(config,
+-                                                   Path::new("lib/libstd.so"));
++                                                   Path::new("lib/libstd.so"),
++                                                   &omit);
+             assert_eq!(res, "$ORIGIN/../lib");
+         }
+     }