1 files changed, 171 insertions, 0 deletions
diff --git a/compiler/rustc_session/src/filesearch.rs b/compiler/rustc_session/src/filesearch.rs
new file mode 100644
index 00000000000..284fca652ec
--- /dev/null
+++ b/compiler/rustc_session/src/filesearch.rs
@@ -0,0 +1,171 @@
+#![allow(non_camel_case_types)]
+
+pub use self::FileMatch::*;
+
+use std::borrow::Cow;
+use std::env;
+use std::fs;
+use std::path::{Path, PathBuf};
+
+use crate::search_paths::{PathKind, SearchPath, SearchPathFile};
+use rustc_fs_util::fix_windows_verbatim_for_gcc;
+use tracing::debug;
+
+#[derive(Copy, Clone)]
+pub enum FileMatch {
+    FileMatches,
+    FileDoesntMatch,
+}
+
+// A module for searching for libraries
+
+#[derive(Clone)]
+pub struct FileSearch<'a> {
+    sysroot: &'a Path,
+    triple: &'a str,
+    search_paths: &'a [SearchPath],
+    tlib_path: &'a SearchPath,
+    kind: PathKind,
+}
+
+impl<'a> FileSearch<'a> {
+    pub fn search_paths(&self) -> impl Iterator<Item = &'a SearchPath> {
+        let kind = self.kind;
+        self.search_paths
+            .iter()
+            .filter(move |sp| sp.kind.matches(kind))
+            .chain(std::iter::once(self.tlib_path))
+    }
+
+    pub fn get_lib_path(&self) -> PathBuf {
+        make_target_lib_path(self.sysroot, self.triple)
+    }
+
+    pub fn get_self_contained_lib_path(&self) -> PathBuf {
+        self.get_lib_path().join("self-contained")
+    }
+
+    pub fn search<F>(&self, mut pick: F)
+    where
+        F: FnMut(&SearchPathFile, PathKind) -> FileMatch,
+    {
+        for search_path in self.search_paths() {
+            debug!("searching {}", search_path.dir.display());
+            fn is_rlib(spf: &SearchPathFile) -> bool {
+                if let Some(f) = &spf.file_name_str { f.ends_with(".rlib") } else { false }
+            }
+            // Reading metadata out of rlibs is faster, and if we find both
+            // an rlib and a dylib we only read one of the files of
+            // metadata, so in the name of speed, bring all rlib files to
+            // the front of the search list.
+            let files1 = search_path.files.iter().filter(|spf| is_rlib(&spf));
+            let files2 = search_path.files.iter().filter(|spf| !is_rlib(&spf));
+            for spf in files1.chain(files2) {
+                debug!("testing {}", spf.path.display());
+                let maybe_picked = pick(spf, search_path.kind);
+                match maybe_picked {
+                    FileMatches => {
+                        debug!("picked {}", spf.path.display());
+                    }
+                    FileDoesntMatch => {
+                        debug!("rejected {}", spf.path.display());
+                    }
+                }
+            }
+        }
+    }
+
+    pub fn new(
+        sysroot: &'a Path,
+        triple: &'a str,
+        search_paths: &'a Vec<SearchPath>,
+        tlib_path: &'a SearchPath,
+        kind: PathKind,
+    ) -> FileSearch<'a> {
+        debug!("using sysroot = {}, triple = {}", sysroot.display(), triple);
+        FileSearch { sysroot, triple, search_paths, tlib_path, kind }
+    }
+
+    // Returns just the directories within the search paths.
+    pub fn search_path_dirs(&self) -> Vec<PathBuf> {
+        self.search_paths().map(|sp| sp.dir.to_path_buf()).collect()
+    }
+
+    // Returns a list of directories where target-specific tool binaries are located.
+    pub fn get_tools_search_paths(&self, self_contained: bool) -> Vec<PathBuf> {
+        let mut p = PathBuf::from(self.sysroot);
+        p.push(find_libdir(self.sysroot).as_ref());
+        p.push(RUST_LIB_DIR);
+        p.push(&self.triple);
+        p.push("bin");
+        if self_contained { vec![p.clone(), p.join("self-contained")] } else { vec![p] }
+    }
+}
+
+pub fn relative_target_lib_path(sysroot: &Path, target_triple: &str) -> PathBuf {
+    let mut p = PathBuf::from(find_libdir(sysroot).as_ref());
+    assert!(p.is_relative());
+    p.push(RUST_LIB_DIR);
+    p.push(target_triple);
+    p.push("lib");
+    p
+}
+
+pub fn make_target_lib_path(sysroot: &Path, target_triple: &str) -> PathBuf {
+    sysroot.join(&relative_target_lib_path(sysroot, target_triple))
+}
+
+pub fn get_or_default_sysroot() -> PathBuf {
+    // Follow symlinks.  If the resolved path is relative, make it absolute.
+    fn canonicalize(path: PathBuf) -> PathBuf {
+        let path = fs::canonicalize(&path).unwrap_or(path);
+        // See comments on this target function, but the gist is that
+        // gcc chokes on verbatim paths which fs::canonicalize generates
+        // so we try to avoid those kinds of paths.
+        fix_windows_verbatim_for_gcc(&path)
+    }
+
+    match env::current_exe() {
+        Ok(exe) => {
+            let mut p = canonicalize(exe);
+            p.pop();
+            p.pop();
+            p
+        }
+        Err(e) => panic!("failed to get current_exe: {}", e),
+    }
+}
+
+// The name of the directory rustc expects libraries to be located.
+fn find_libdir(sysroot: &Path) -> Cow<'static, str> {
+    // FIXME: This is a quick hack to make the rustc binary able to locate
+    // Rust libraries in Linux environments where libraries might be installed
+    // to lib64/lib32. This would be more foolproof by basing the sysroot off
+    // of the directory where `librustc_driver` is located, rather than
+    // where the rustc binary is.
+    // If --libdir is set during configuration to the value other than
+    // "lib" (i.e., non-default), this value is used (see issue #16552).
+
+    #[cfg(target_pointer_width = "64")]
+    const PRIMARY_LIB_DIR: &str = "lib64";
+
+    #[cfg(target_pointer_width = "32")]
+    const PRIMARY_LIB_DIR: &str = "lib32";
+
+    const SECONDARY_LIB_DIR: &str = "lib";
+
+    match option_env!("CFG_LIBDIR_RELATIVE") {
+        Some(libdir) if libdir != "lib" => libdir.into(),
+        _ => {
+            if sysroot.join(PRIMARY_LIB_DIR).join(RUST_LIB_DIR).exists() {
+                PRIMARY_LIB_DIR.into()
+            } else {
+                SECONDARY_LIB_DIR.into()
+            }
+        }
+    }
+}
+
+// The name of rustc's own place to organize libraries.
+// Used to be "rustc", now the default is "rustlib"
+const RUST_LIB_DIR: &str = "rustlib";