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