src/librustc_codegen_ssa/back/rpath.rs

   1 use pathdiff::diff_paths;
   2 use rustc_data_structures::fx::FxHashSet;
   3 use std::env;
   4 use std::fs;
   5 use std::path::{Path, PathBuf};
   6
   7 use rustc_hir::def_id::CrateNum;
   8 use rustc_middle::middle::cstore::LibSource;
   9
  10 pub struct RPathConfig<'a> {
  11     pub used_crates: &'a [(CrateNum, LibSource)],
  12     pub out_filename: PathBuf,
  13     pub is_like_osx: bool,
  14     pub has_rpath: bool,
  15     pub linker_is_gnu: bool,
  16     pub get_install_prefix_lib_path: &'a mut dyn FnMut() -> PathBuf,
  17 }
  18
  19 pub fn get_rpath_flags(config: &mut RPathConfig<'_>) -> Vec<String> {
  20     // No rpath on windows
  21     if !config.has_rpath {
  22         return Vec::new();
  23     }
  24
  25     debug!("preparing the RPATH!");
  26
  27     let libs = config.used_crates.clone();
  28     let libs = libs.iter().filter_map(|&(_, ref l)| l.option()).collect::<Vec<_>>();
  29     let rpaths = get_rpaths(config, &libs);
  30     let mut flags = rpaths_to_flags(&rpaths);
  31
  32     // Use DT_RUNPATH instead of DT_RPATH if available
  33     if config.linker_is_gnu {
  34         flags.push("-Wl,--enable-new-dtags".to_owned());
  35     }
  36
  37     flags
  38 }
  39
  40 fn rpaths_to_flags(rpaths: &[String]) -> Vec<String> {
  41     let mut ret = Vec::with_capacity(rpaths.len()); // the minimum needed capacity
  42
  43     for rpath in rpaths {
  44         if rpath.contains(',') {
  45             ret.push("-Wl,-rpath".into());
  46             ret.push("-Xlinker".into());
  47             ret.push(rpath.clone());
  48         } else {
  49             ret.push(format!("-Wl,-rpath,{}", &(*rpath)));
  50         }
  51     }
  52
  53     ret
  54 }
  55
  56 fn get_rpaths(config: &mut RPathConfig<'_>, libs: &[PathBuf]) -> Vec<String> {
  57     debug!("output: {:?}", config.out_filename.display());
  58     debug!("libs:");
  59     for libpath in libs {
  60         debug!("    {:?}", libpath.display());
  61     }
  62
  63     // Use relative paths to the libraries. Binaries can be moved
  64     // as long as they maintain the relative relationship to the
  65     // crates they depend on.
  66     let rel_rpaths = get_rpaths_relative_to_output(config, libs);
  67
  68     // And a final backup rpath to the global library location.
  69     let fallback_rpaths = vec![get_install_prefix_rpath(config)];
  70
  71     fn log_rpaths(desc: &str, rpaths: &[String]) {
  72         debug!("{} rpaths:", desc);
  73         for rpath in rpaths {
  74             debug!("    {}", *rpath);
  75         }
  76     }
  77
  78     log_rpaths("relative", &rel_rpaths);
  79     log_rpaths("fallback", &fallback_rpaths);
  80
  81     let mut rpaths = rel_rpaths;
  82     rpaths.extend_from_slice(&fallback_rpaths);
  83
  84     // Remove duplicates
  85     minimize_rpaths(&rpaths)
  86 }
  87
  88 fn get_rpaths_relative_to_output(config: &mut RPathConfig<'_>, libs: &[PathBuf]) -> Vec<String> {
  89     libs.iter().map(|a| get_rpath_relative_to_output(config, a)).collect()
  90 }
  91
  92 fn get_rpath_relative_to_output(config: &mut RPathConfig<'_>, lib: &Path) -> String {
  93     // Mac doesn't appear to support $ORIGIN
  94     let prefix = if config.is_like_osx { "@loader_path" } else { "$ORIGIN" };
  95
  96     let cwd = env::current_dir().unwrap();
  97     let mut lib = fs::canonicalize(&cwd.join(lib)).unwrap_or_else(|_| cwd.join(lib));
  98     lib.pop(); // strip filename
  99     let mut output = cwd.join(&config.out_filename);
 100     output.pop(); // strip filename
 101     let output = fs::canonicalize(&output).unwrap_or(output);
 102     let relative = path_relative_from(&lib, &output)
 103         .unwrap_or_else(|| panic!("couldn't create relative path from {:?} to {:?}", output, lib));
 104     // FIXME (#9639): This needs to handle non-utf8 paths
 105     format!("{}/{}", prefix, relative.to_str().expect("non-utf8 component in path"))
 106 }
 107
 108 // This routine is adapted from the *old* Path's `path_relative_from`
 109 // function, which works differently from the new `relative_from` function.
 110 // In particular, this handles the case on unix where both paths are
 111 // absolute but with only the root as the common directory.
 112 fn path_relative_from(path: &Path, base: &Path) -> Option<PathBuf> {
 113     diff_paths(path, base)
 114 }
 115
 116 fn get_install_prefix_rpath(config: &mut RPathConfig<'_>) -> String {
 117     let path = (config.get_install_prefix_lib_path)();
 118     let path = env::current_dir().unwrap().join(&path);
 119     // FIXME (#9639): This needs to handle non-utf8 paths
 120     path.to_str().expect("non-utf8 component in rpath").to_owned()
 121 }
 122
 123 fn minimize_rpaths(rpaths: &[String]) -> Vec<String> {
 124     let mut set = FxHashSet::default();
 125     let mut minimized = Vec::new();
 126     for rpath in rpaths {
 127         if set.insert(rpath) {
 128             minimized.push(rpath.clone());
 129         }
 130     }
 131     minimized
 132 }
 133
 134 #[cfg(all(unix, test))]
 135 mod tests;