compiler/rustc_session/src/filesearch.rs

   1 pub use self::FileMatch::*;
   2
   3 use std::borrow::Cow;
   4 use std::env;
   5 use std::fs;
   6 use std::path::{Path, PathBuf};
   7
   8 use crate::search_paths::{PathKind, SearchPath, SearchPathFile};
   9 use rustc_fs_util::fix_windows_verbatim_for_gcc;
  10 use tracing::debug;
  11
  12 #[derive(Copy, Clone)]
  13 pub enum FileMatch {
  14     FileMatches,
  15     FileDoesntMatch,
  16 }
  17
  18 // A module for searching for libraries
  19
  20 #[derive(Clone)]
  21 pub struct FileSearch<'a> {
  22     sysroot: &'a Path,
  23     triple: &'a str,
  24     search_paths: &'a [SearchPath],
  25     tlib_path: &'a SearchPath,
  26     kind: PathKind,
  27 }
  28
  29 impl<'a> FileSearch<'a> {
  30     pub fn search_paths(&self) -> impl Iterator<Item = &'a SearchPath> {
  31         let kind = self.kind;
  32         self.search_paths
  33             .iter()
  34             .filter(move |sp| sp.kind.matches(kind))
  35             .chain(std::iter::once(self.tlib_path))
  36     }
  37
  38     pub fn get_lib_path(&self) -> PathBuf {
  39         make_target_lib_path(self.sysroot, self.triple)
  40     }
  41
  42     pub fn get_self_contained_lib_path(&self) -> PathBuf {
  43         self.get_lib_path().join("self-contained")
  44     }
  45
  46     pub fn search<F>(&self, mut pick: F)
  47     where
  48         F: FnMut(&SearchPathFile, PathKind) -> FileMatch,
  49     {
  50         for search_path in self.search_paths() {
  51             debug!("searching {}", search_path.dir.display());
  52             fn is_rlib(spf: &SearchPathFile) -> bool {
  53                 if let Some(f) = &spf.file_name_str { f.ends_with(".rlib") } else { false }
  54             }
  55             // Reading metadata out of rlibs is faster, and if we find both
  56             // an rlib and a dylib we only read one of the files of
  57             // metadata, so in the name of speed, bring all rlib files to
  58             // the front of the search list.
  59             let files1 = search_path.files.iter().filter(|spf| is_rlib(&spf));
  60             let files2 = search_path.files.iter().filter(|spf| !is_rlib(&spf));
  61             for spf in files1.chain(files2) {
  62                 debug!("testing {}", spf.path.display());
  63                 let maybe_picked = pick(spf, search_path.kind);
  64                 match maybe_picked {
  65                     FileMatches => {
  66                         debug!("picked {}", spf.path.display());
  67                     }
  68                     FileDoesntMatch => {
  69                         debug!("rejected {}", spf.path.display());
  70                     }
  71                 }
  72             }
  73         }
  74     }
  75
  76     pub fn new(
  77         sysroot: &'a Path,
  78         triple: &'a str,
  79         search_paths: &'a [SearchPath],
  80         tlib_path: &'a SearchPath,
  81         kind: PathKind,
  82     ) -> FileSearch<'a> {
  83         debug!("using sysroot = {}, triple = {}", sysroot.display(), triple);
  84         FileSearch { sysroot, triple, search_paths, tlib_path, kind }
  85     }
  86
  87     // Returns just the directories within the search paths.
  88     pub fn search_path_dirs(&self) -> Vec<PathBuf> {
  89         self.search_paths().map(|sp| sp.dir.to_path_buf()).collect()
  90     }
  91
  92     // Returns a list of directories where target-specific tool binaries are located.
  93     pub fn get_tools_search_paths(&self, self_contained: bool) -> Vec<PathBuf> {
  94         let mut p = PathBuf::from(self.sysroot);
  95         p.push(find_libdir(self.sysroot).as_ref());
  96         p.push(RUST_LIB_DIR);
  97         p.push(&self.triple);
  98         p.push("bin");
  99         if self_contained { vec![p.clone(), p.join("self-contained")] } else { vec![p] }
 100     }
 101 }
 102
 103 pub fn relative_target_lib_path(sysroot: &Path, target_triple: &str) -> PathBuf {
 104     let mut p = PathBuf::from(find_libdir(sysroot).as_ref());
 105     assert!(p.is_relative());
 106     p.push(RUST_LIB_DIR);
 107     p.push(target_triple);
 108     p.push("lib");
 109     p
 110 }
 111
 112 pub fn make_target_lib_path(sysroot: &Path, target_triple: &str) -> PathBuf {
 113     sysroot.join(&relative_target_lib_path(sysroot, target_triple))
 114 }
 115
 116 // This function checks if sysroot is found using env::args().next(), and if it
 117 // is not found, uses env::current_exe() to imply sysroot.
 118 pub fn get_or_default_sysroot() -> PathBuf {
 119     // Follow symlinks.  If the resolved path is relative, make it absolute.
 120     fn canonicalize(path: PathBuf) -> PathBuf {
 121         let path = fs::canonicalize(&path).unwrap_or(path);
 122         // See comments on this target function, but the gist is that
 123         // gcc chokes on verbatim paths which fs::canonicalize generates
 124         // so we try to avoid those kinds of paths.
 125         fix_windows_verbatim_for_gcc(&path)
 126     }
 127
 128     // Use env::current_exe() to get the path of the executable following
 129     // symlinks/canonicalizing components.
 130     fn from_current_exe() -> PathBuf {
 131         match env::current_exe() {
 132             Ok(exe) => {
 133                 let mut p = canonicalize(exe);
 134                 p.pop();
 135                 p.pop();
 136                 p
 137             }
 138             Err(e) => panic!("failed to get current_exe: {}", e),
 139         }
 140     }
 141
 142     // Use env::args().next() to get the path of the executable without
 143     // following symlinks/canonicalizing any component. This makes the rustc
 144     // binary able to locate Rust libraries in systems using content-addressable
 145     // storage (CAS).
 146     fn from_env_args_next() -> Option<PathBuf> {
 147         match env::args_os().next() {
 148             Some(first_arg) => {
 149                 let mut p = PathBuf::from(first_arg);
 150
 151                 // Check if sysroot is found using env::args().next() only if the rustc in argv[0]
 152                 // is a symlink (see #79253). We might want to change/remove it to conform with
 153                 // https://www.gnu.org/prep/standards/standards.html#Finding-Program-Files in the
 154                 // future.
 155                 if fs::read_link(&p).is_err() {
 156                     // Path is not a symbolic link or does not exist.
 157                     return None;
 158                 }
 159
 160                 p.pop();
 161                 p.pop();
 162                 let mut libdir = PathBuf::from(&p);
 163                 libdir.push(find_libdir(&p).as_ref());
 164                 if libdir.exists() { Some(p) } else { None }
 165             }
 166             None => None,
 167         }
 168     }
 169
 170     // Check if sysroot is found using env::args().next(), and if is not found,
 171     // use env::current_exe() to imply sysroot.
 172     from_env_args_next().unwrap_or(from_current_exe())
 173 }
 174
 175 // The name of the directory rustc expects libraries to be located.
 176 fn find_libdir(sysroot: &Path) -> Cow<'static, str> {
 177     // FIXME: This is a quick hack to make the rustc binary able to locate
 178     // Rust libraries in Linux environments where libraries might be installed
 179     // to lib64/lib32. This would be more foolproof by basing the sysroot off
 180     // of the directory where `librustc_driver` is located, rather than
 181     // where the rustc binary is.
 182     // If --libdir is set during configuration to the value other than
 183     // "lib" (i.e., non-default), this value is used (see issue #16552).
 184
 185     #[cfg(target_pointer_width = "64")]
 186     const PRIMARY_LIB_DIR: &str = "lib64";
 187
 188     #[cfg(target_pointer_width = "32")]
 189     const PRIMARY_LIB_DIR: &str = "lib32";
 190
 191     const SECONDARY_LIB_DIR: &str = "lib";
 192
 193     match option_env!("CFG_LIBDIR_RELATIVE") {
 194         None | Some("lib") => {
 195             if sysroot.join(PRIMARY_LIB_DIR).join(RUST_LIB_DIR).exists() {
 196                 PRIMARY_LIB_DIR.into()
 197             } else {
 198                 SECONDARY_LIB_DIR.into()
 199             }
 200         }
 201         Some(libdir) => libdir.into(),
 202     }
 203 }
 204
 205 // The name of rustc's own place to organize libraries.
 206 // Used to be "rustc", now the default is "rustlib"
 207 const RUST_LIB_DIR: &str = "rustlib";