compiler/rustc_session/src/filesearch.rs

   1 pub use self::FileMatch::*;
   2
   3 use std::env;
   4 use std::fs;
   5 use std::path::{Path, PathBuf};
   6
   7 use crate::search_paths::{PathKind, SearchPath, SearchPathFile};
   8 use rustc_fs_util::fix_windows_verbatim_for_gcc;
   9 use tracing::debug;
  10
  11 #[derive(Copy, Clone)]
  12 pub enum FileMatch {
  13     FileMatches,
  14     FileDoesntMatch,
  15 }
  16
  17 // A module for searching for libraries
  18
  19 #[derive(Clone)]
  20 pub struct FileSearch<'a> {
  21     sysroot: &'a Path,
  22     triple: &'a str,
  23     search_paths: &'a [SearchPath],
  24     tlib_path: &'a SearchPath,
  25     kind: PathKind,
  26 }
  27
  28 impl<'a> FileSearch<'a> {
  29     pub fn search_paths(&self) -> impl Iterator<Item = &'a SearchPath> {
  30         let kind = self.kind;
  31         self.search_paths
  32             .iter()
  33             .filter(move |sp| sp.kind.matches(kind))
  34             .chain(std::iter::once(self.tlib_path))
  35     }
  36
  37     pub fn get_lib_path(&self) -> PathBuf {
  38         make_target_lib_path(self.sysroot, self.triple)
  39     }
  40
  41     pub fn get_self_contained_lib_path(&self) -> PathBuf {
  42         self.get_lib_path().join("self-contained")
  43     }
  44
  45     pub fn search<F>(&self, mut pick: F)
  46     where
  47         F: FnMut(&SearchPathFile, PathKind) -> FileMatch,
  48     {
  49         for search_path in self.search_paths() {
  50             debug!("searching {}", search_path.dir.display());
  51             fn is_rlib(spf: &SearchPathFile) -> bool {
  52                 if let Some(f) = &spf.file_name_str { f.ends_with(".rlib") } else { false }
  53             }
  54             // Reading metadata out of rlibs is faster, and if we find both
  55             // an rlib and a dylib we only read one of the files of
  56             // metadata, so in the name of speed, bring all rlib files to
  57             // the front of the search list.
  58             let files1 = search_path.files.iter().filter(|spf| is_rlib(&spf));
  59             let files2 = search_path.files.iter().filter(|spf| !is_rlib(&spf));
  60             for spf in files1.chain(files2) {
  61                 debug!("testing {}", spf.path.display());
  62                 let maybe_picked = pick(spf, search_path.kind);
  63                 match maybe_picked {
  64                     FileMatches => {
  65                         debug!("picked {}", spf.path.display());
  66                     }
  67                     FileDoesntMatch => {
  68                         debug!("rejected {}", spf.path.display());
  69                     }
  70                 }
  71             }
  72         }
  73     }
  74
  75     pub fn new(
  76         sysroot: &'a Path,
  77         triple: &'a str,
  78         search_paths: &'a [SearchPath],
  79         tlib_path: &'a SearchPath,
  80         kind: PathKind,
  81     ) -> FileSearch<'a> {
  82         debug!("using sysroot = {}, triple = {}", sysroot.display(), triple);
  83         FileSearch { sysroot, triple, search_paths, tlib_path, kind }
  84     }
  85
  86     // Returns just the directories within the search paths.
  87     pub fn search_path_dirs(&self) -> Vec<PathBuf> {
  88         self.search_paths().map(|sp| sp.dir.to_path_buf()).collect()
  89     }
  90
  91     // Returns a list of directories where target-specific tool binaries are located.
  92     pub fn get_tools_search_paths(&self, self_contained: bool) -> Vec<PathBuf> {
  93         let rustlib_path = rustc_target::target_rustlib_path(self.sysroot, &self.triple);
  94         let p = std::array::IntoIter::new([
  95             Path::new(&self.sysroot),
  96             Path::new(&rustlib_path),
  97             Path::new("bin"),
  98         ])
  99         .collect::<PathBuf>();
 100         if self_contained { vec![p.clone(), p.join("self-contained")] } else { vec![p] }
 101     }
 102 }
 103
 104 pub fn make_target_lib_path(sysroot: &Path, target_triple: &str) -> PathBuf {
 105     let rustlib_path = rustc_target::target_rustlib_path(sysroot, target_triple);
 106     std::array::IntoIter::new([sysroot, Path::new(&rustlib_path), Path::new("lib")])
 107         .collect::<PathBuf>()
 108 }
 109
 110 // This function checks if sysroot is found using env::args().next(), and if it
 111 // is not found, uses env::current_exe() to imply sysroot.
 112 pub fn get_or_default_sysroot() -> PathBuf {
 113     // Follow symlinks.  If the resolved path is relative, make it absolute.
 114     fn canonicalize(path: PathBuf) -> PathBuf {
 115         let path = fs::canonicalize(&path).unwrap_or(path);
 116         // See comments on this target function, but the gist is that
 117         // gcc chokes on verbatim paths which fs::canonicalize generates
 118         // so we try to avoid those kinds of paths.
 119         fix_windows_verbatim_for_gcc(&path)
 120     }
 121
 122     // Use env::current_exe() to get the path of the executable following
 123     // symlinks/canonicalizing components.
 124     fn from_current_exe() -> PathBuf {
 125         match env::current_exe() {
 126             Ok(exe) => {
 127                 let mut p = canonicalize(exe);
 128                 p.pop();
 129                 p.pop();
 130                 p
 131             }
 132             Err(e) => panic!("failed to get current_exe: {}", e),
 133         }
 134     }
 135
 136     // Use env::args().next() to get the path of the executable without
 137     // following symlinks/canonicalizing any component. This makes the rustc
 138     // binary able to locate Rust libraries in systems using content-addressable
 139     // storage (CAS).
 140     fn from_env_args_next() -> Option<PathBuf> {
 141         match env::args_os().next() {
 142             Some(first_arg) => {
 143                 let mut p = PathBuf::from(first_arg);
 144
 145                 // Check if sysroot is found using env::args().next() only if the rustc in argv[0]
 146                 // is a symlink (see #79253). We might want to change/remove it to conform with
 147                 // https://www.gnu.org/prep/standards/standards.html#Finding-Program-Files in the
 148                 // future.
 149                 if fs::read_link(&p).is_err() {
 150                     // Path is not a symbolic link or does not exist.
 151                     return None;
 152                 }
 153
 154                 // Pop off `bin/rustc`, obtaining the suspected sysroot.
 155                 p.pop();
 156                 p.pop();
 157                 // Look for the target rustlib directory in the suspected sysroot.
 158                 let mut rustlib_path = rustc_target::target_rustlib_path(&p, "dummy");
 159                 rustlib_path.pop(); // pop off the dummy target.
 160                 if rustlib_path.exists() { Some(p) } else { None }
 161             }
 162             None => None,
 163         }
 164     }
 165
 166     // Check if sysroot is found using env::args().next(), and if is not found,
 167     // use env::current_exe() to imply sysroot.
 168     from_env_args_next().unwrap_or_else(from_current_exe)
 169 }