1 //! A module for searching for libraries
3 use smallvec::{smallvec, SmallVec};
6 use std::path::{Path, PathBuf};
8 use crate::search_paths::{PathKind, SearchPath};
9 use rustc_fs_util::fix_windows_verbatim_for_gcc;
11 #[derive(Copy, Clone)]
18 pub struct FileSearch<'a> {
21 search_paths: &'a [SearchPath],
22 tlib_path: &'a SearchPath,
26 impl<'a> FileSearch<'a> {
27 pub fn search_paths(&self) -> impl Iterator<Item = &'a SearchPath> {
31 .filter(move |sp| sp.kind.matches(kind))
32 .chain(std::iter::once(self.tlib_path))
35 pub fn get_lib_path(&self) -> PathBuf {
36 make_target_lib_path(self.sysroot, self.triple)
39 pub fn get_self_contained_lib_path(&self) -> PathBuf {
40 self.get_lib_path().join("self-contained")
46 search_paths: &'a [SearchPath],
47 tlib_path: &'a SearchPath,
50 debug!("using sysroot = {}, triple = {}", sysroot.display(), triple);
51 FileSearch { sysroot, triple, search_paths, tlib_path, kind }
54 /// Returns just the directories within the search paths.
55 pub fn search_path_dirs(&self) -> Vec<PathBuf> {
56 self.search_paths().map(|sp| sp.dir.to_path_buf()).collect()
60 pub fn make_target_lib_path(sysroot: &Path, target_triple: &str) -> PathBuf {
61 let rustlib_path = rustc_target::target_rustlib_path(sysroot, target_triple);
62 PathBuf::from_iter([sysroot, Path::new(&rustlib_path), Path::new("lib")])
66 fn current_dll_path() -> Result<PathBuf, String> {
67 use std::ffi::{CStr, OsStr};
68 use std::os::unix::prelude::*;
71 let addr = current_dll_path as usize as *mut _;
72 let mut info = std::mem::zeroed();
73 if libc::dladdr(addr, &mut info) == 0 {
74 return Err("dladdr failed".into());
76 if info.dli_fname.is_null() {
77 return Err("dladdr returned null pointer".into());
79 let bytes = CStr::from_ptr(info.dli_fname).to_bytes();
80 let os = OsStr::from_bytes(bytes);
86 fn current_dll_path() -> Result<PathBuf, String> {
87 use std::ffi::OsString;
89 use std::os::windows::prelude::*;
92 use winapi::um::libloaderapi::{
93 GetModuleFileNameW, GetModuleHandleExW, GET_MODULE_HANDLE_EX_FLAG_FROM_ADDRESS,
97 let mut module = ptr::null_mut();
98 let r = GetModuleHandleExW(
99 GET_MODULE_HANDLE_EX_FLAG_FROM_ADDRESS,
100 current_dll_path as usize as *mut _,
104 return Err(format!("GetModuleHandleExW failed: {}", io::Error::last_os_error()));
106 let mut space = Vec::with_capacity(1024);
107 let r = GetModuleFileNameW(module, space.as_mut_ptr(), space.capacity() as u32);
109 return Err(format!("GetModuleFileNameW failed: {}", io::Error::last_os_error()));
112 if r >= space.capacity() {
113 return Err(format!("our buffer was too small? {}", io::Error::last_os_error()));
116 let os = OsString::from_wide(&space);
117 Ok(PathBuf::from(os))
121 pub fn sysroot_candidates() -> SmallVec<[PathBuf; 2]> {
122 let target = crate::config::host_triple();
123 let mut sysroot_candidates: SmallVec<[PathBuf; 2]> =
124 smallvec![get_or_default_sysroot().expect("Failed finding sysroot")];
125 let path = current_dll_path().and_then(|s| Ok(s.canonicalize().map_err(|e| e.to_string())?));
126 if let Ok(dll) = path {
127 // use `parent` twice to chop off the file name and then also the
128 // directory containing the dll which should be either `lib` or `bin`.
129 if let Some(path) = dll.parent().and_then(|p| p.parent()) {
130 // The original `path` pointed at the `rustc_driver` crate's dll.
131 // Now that dll should only be in one of two locations. The first is
132 // in the compiler's libdir, for example `$sysroot/lib/*.dll`. The
133 // other is the target's libdir, for example
134 // `$sysroot/lib/rustlib/$target/lib/*.dll`.
136 // We don't know which, so let's assume that if our `path` above
137 // ends in `$target` we *could* be in the target libdir, and always
138 // assume that we may be in the main libdir.
139 sysroot_candidates.push(path.to_owned());
141 if path.ends_with(target) {
142 sysroot_candidates.extend(
143 path.parent() // chop off `$target`
144 .and_then(|p| p.parent()) // chop off `rustlib`
145 .and_then(|p| p.parent()) // chop off `lib`
146 .map(|s| s.to_owned()),
152 return sysroot_candidates;
155 /// This function checks if sysroot is found using env::args().next(), and if it
156 /// is not found, finds sysroot from current rustc_driver dll.
157 pub fn get_or_default_sysroot() -> Result<PathBuf, String> {
158 // Follow symlinks. If the resolved path is relative, make it absolute.
159 fn canonicalize(path: PathBuf) -> PathBuf {
160 let path = fs::canonicalize(&path).unwrap_or(path);
161 // See comments on this target function, but the gist is that
162 // gcc chokes on verbatim paths which fs::canonicalize generates
163 // so we try to avoid those kinds of paths.
164 fix_windows_verbatim_for_gcc(&path)
167 fn default_from_rustc_driver_dll() -> Result<PathBuf, String> {
168 let dll = current_dll_path().and_then(|s| Ok(canonicalize(s)))?;
170 // `dll` will be in one of the following two:
171 // - compiler's libdir: $sysroot/lib/*.dll
172 // - target's libdir: $sysroot/lib/rustlib/$target/lib/*.dll
174 // use `parent` twice to chop off the file name and then also the
175 // directory containing the dll
176 let dir = dll.parent().and_then(|p| p.parent()).ok_or(format!(
177 "Could not move 2 levels upper using `parent()` on {}",
181 // if `dir` points target's dir, move up to the sysroot
182 if dir.ends_with(crate::config::host_triple()) {
183 dir.parent() // chop off `$target`
184 .and_then(|p| p.parent()) // chop off `rustlib`
185 .and_then(|p| p.parent()) // chop off `lib`
186 .map(|s| s.to_owned())
188 "Could not move 3 levels upper using `parent()` on {}",
196 // Use env::args().next() to get the path of the executable without
197 // following symlinks/canonicalizing any component. This makes the rustc
198 // binary able to locate Rust libraries in systems using content-addressable
200 fn from_env_args_next() -> Option<PathBuf> {
201 match env::args_os().next() {
203 let mut p = PathBuf::from(first_arg);
205 // Check if sysroot is found using env::args().next() only if the rustc in argv[0]
206 // is a symlink (see #79253). We might want to change/remove it to conform with
207 // https://www.gnu.org/prep/standards/standards.html#Finding-Program-Files in the
209 if fs::read_link(&p).is_err() {
210 // Path is not a symbolic link or does not exist.
214 // Pop off `bin/rustc`, obtaining the suspected sysroot.
217 // Look for the target rustlib directory in the suspected sysroot.
218 let mut rustlib_path = rustc_target::target_rustlib_path(&p, "dummy");
219 rustlib_path.pop(); // pop off the dummy target.
220 if rustlib_path.exists() { Some(p) } else { None }
226 Ok(from_env_args_next().unwrap_or(default_from_rustc_driver_dll()?))