Add try_canonicalize to rustc_fs_util and use it over fs::canonicalize

Cargo.lock

@@ -4826,6 +4826,7 @@ dependencies = [
  "rustc_data_structures",
  "rustc_errors",
  "rustc_expand",
+ "rustc_fs_util",
  "rustc_hir",
  "rustc_hir_analysis",
  "rustc_hir_typeck",
@@ -4950,6 +4951,7 @@ dependencies = [
  "rustc_errors",
  "rustc_expand",
  "rustc_feature",
+ "rustc_fs_util",
  "rustc_hir",
  "rustc_hir_pretty",
  "rustc_index",
@@ -5334,6 +5336,7 @@ dependencies = [
  "rustc_abi",
  "rustc_data_structures",
  "rustc_feature",
+ "rustc_fs_util",
  "rustc_index",
  "rustc_macros",
  "rustc_serialize",

compiler/rustc_fs_util/src/lib.rs

@@ -1,10 +1,11 @@
+#![feature(absolute_path)]
 #![deny(rustc::untranslatable_diagnostic)]
 #![deny(rustc::diagnostic_outside_of_impl)]
 
 use std::ffi::CString;
 use std::fs;
 use std::io;
-use std::path::{Path, PathBuf};
+use std::path::{absolute, Path, PathBuf};
 
 // Unfortunately, on windows, it looks like msvcrt.dll is silently translating
 // verbatim paths under the hood to non-verbatim paths! This manifests itself as
@@ -91,3 +92,8 @@ pub fn path_to_c_string(p: &Path) -> CString {
 pub fn path_to_c_string(p: &Path) -> CString {
     CString::new(p.to_str().unwrap()).unwrap()
 }
+
+#[inline]
+pub fn try_canonicalize<P: AsRef<Path>>(path: P) -> io::Result<PathBuf> {
+    fs::canonicalize(&path).or_else(|_| absolute(&path))
+}

compiler/rustc_incremental/src/persist/fs.rs

@@ -108,7 +108,7 @@ use rustc_data_structures::fx::{FxHashMap, FxHashSet};
 use rustc_data_structures::svh::Svh;
 use rustc_data_structures::{base_n, flock};
 use rustc_errors::ErrorGuaranteed;
-use rustc_fs_util::{link_or_copy, LinkOrCopy};
+use rustc_fs_util::{link_or_copy, try_canonicalize, LinkOrCopy};
 use rustc_session::{Session, StableCrateId};
 use rustc_span::Symbol;
 
@@ -223,7 +223,7 @@ pub fn prepare_session_directory(
     // because, on windows, long paths can cause problems;
     // canonicalization inserts this weird prefix that makes windows
     // tolerate long paths.
-    let crate_dir = match crate_dir.canonicalize() {
+    let crate_dir = match try_canonicalize(&crate_dir) {
         Ok(v) => v,
         Err(err) => {
             return Err(sess.emit_err(errors::CanonicalizePath { path: crate_dir, err }));
@@ -867,7 +867,7 @@ fn all_except_most_recent(
 /// before passing it to std::fs::remove_dir_all(). This will convert the path
 /// into the '\\?\' format, which supports much longer paths.
 fn safe_remove_dir_all(p: &Path) -> io::Result<()> {
-    let canonicalized = match std_fs::canonicalize(p) {
+    let canonicalized = match try_canonicalize(p) {
         Ok(canonicalized) => canonicalized,
         Err(err) if err.kind() == io::ErrorKind::NotFound => return Ok(()),
         Err(err) => return Err(err),
@@ -877,7 +877,7 @@ fn safe_remove_dir_all(p: &Path) -> io::Result<()> {
 }
 
 fn safe_remove_file(p: &Path) -> io::Result<()> {
-    let canonicalized = match std_fs::canonicalize(p) {
+    let canonicalized = match try_canonicalize(p) {
         Ok(canonicalized) => canonicalized,
         Err(err) if err.kind() == io::ErrorKind::NotFound => return Ok(()),
         Err(err) => return Err(err),

compiler/rustc_interface/Cargo.toml

@@ -16,6 +16,7 @@ rustc_attr = { path = "../rustc_attr" }
 rustc_borrowck = { path = "../rustc_borrowck" }
 rustc_builtin_macros = { path = "../rustc_builtin_macros" }
 rustc_expand = { path = "../rustc_expand" }
+rustc_fs_util = { path = "../rustc_fs_util" }
 rustc_macros = { path = "../rustc_macros" }
 rustc_parse = { path = "../rustc_parse" }
 rustc_session = { path = "../rustc_session" }

compiler/rustc_interface/src/passes.rs

@@ -12,6 +12,7 @@ use rustc_data_structures::steal::Steal;
 use rustc_data_structures::sync::{Lrc, OnceCell, WorkerLocal};
 use rustc_errors::PResult;
 use rustc_expand::base::{ExtCtxt, LintStoreExpand};
+use rustc_fs_util::try_canonicalize;
 use rustc_hir::def_id::{StableCrateId, LOCAL_CRATE};
 use rustc_lint::{unerased_lint_store, BufferedEarlyLint, EarlyCheckNode, LintStore};
 use rustc_metadata::creader::CStore;
@@ -405,12 +406,12 @@ where
 }
 
 fn output_contains_path(output_paths: &[PathBuf], input_path: &Path) -> bool {
-    let input_path = input_path.canonicalize().ok();
+    let input_path = try_canonicalize(input_path).ok();
     if input_path.is_none() {
         return false;
     }
     let check = |output_path: &PathBuf| {
-        if output_path.canonicalize().ok() == input_path { Some(()) } else { None }
+        if try_canonicalize(output_path).ok() == input_path { Some(()) } else { None }
     };
     check_output(output_paths, check).is_some()
 }

compiler/rustc_metadata/Cargo.toml

@@ -18,6 +18,7 @@ rustc_attr = { path = "../rustc_attr" }
 rustc_data_structures = { path = "../rustc_data_structures" }
 rustc_errors = { path = "../rustc_errors" }
 rustc_feature = { path = "../rustc_feature" }
+rustc_fs_util = { path = "../rustc_fs_util" }
 rustc_hir = { path = "../rustc_hir" }
 rustc_hir_pretty = { path = "../rustc_hir_pretty" }
 rustc_target = { path = "../rustc_target" }

compiler/rustc_metadata/src/locator.rs

@@ -222,6 +222,7 @@ use rustc_data_structures::owning_ref::OwningRef;
 use rustc_data_structures::svh::Svh;
 use rustc_data_structures::sync::MetadataRef;
 use rustc_errors::{DiagnosticArgValue, FatalError, IntoDiagnosticArg};
+use rustc_fs_util::try_canonicalize;
 use rustc_session::config::{self, CrateType};
 use rustc_session::cstore::{CrateSource, MetadataLoader};
 use rustc_session::filesearch::FileSearch;
@@ -236,7 +237,7 @@ use snap::read::FrameDecoder;
 use std::borrow::Cow;
 use std::io::{Read, Result as IoResult, Write};
 use std::path::{Path, PathBuf};
-use std::{cmp, fmt, fs};
+use std::{cmp, fmt};
 
 #[derive(Clone)]
 pub(crate) struct CrateLocator<'a> {
@@ -441,7 +442,7 @@ impl<'a> CrateLocator<'a> {
                 info!("lib candidate: {}", spf.path.display());
 
                 let (rlibs, rmetas, dylibs) = candidates.entry(hash.to_string()).or_default();
-                let path = fs::canonicalize(&spf.path).unwrap_or_else(|_| spf.path.clone());
+                let path = try_canonicalize(&spf.path).unwrap_or_else(|_| spf.path.clone());
                 if seen_paths.contains(&path) {
                     continue;
                 };
@@ -636,7 +637,7 @@ impl<'a> CrateLocator<'a> {
             // as well.
             if let Some((prev, _)) = &ret {
                 let sysroot = self.sysroot;
-                let sysroot = sysroot.canonicalize().unwrap_or_else(|_| sysroot.to_path_buf());
+                let sysroot = try_canonicalize(sysroot).unwrap_or_else(|_| sysroot.to_path_buf());
                 if prev.starts_with(&sysroot) {
                     continue;
                 }

compiler/rustc_session/src/filesearch.rs

@@ -1,5 +1,6 @@
 //! A module for searching for libraries
 
+use rustc_fs_util::try_canonicalize;
 use smallvec::{smallvec, SmallVec};
 use std::env;
 use std::fs;
@@ -122,7 +123,7 @@ pub fn sysroot_candidates() -> SmallVec<[PathBuf; 2]> {
     let target = crate::config::host_triple();
     let mut sysroot_candidates: SmallVec<[PathBuf; 2]> =
         smallvec![get_or_default_sysroot().expect("Failed finding sysroot")];
-    let path = current_dll_path().and_then(|s| s.canonicalize().map_err(|e| e.to_string()));
+    let path = current_dll_path().and_then(|s| try_canonicalize(s).map_err(|e| e.to_string()));
     if let Ok(dll) = path {
         // use `parent` twice to chop off the file name and then also the
         // directory containing the dll which should be either `lib` or `bin`.
@@ -157,7 +158,7 @@ pub fn sysroot_candidates() -> SmallVec<[PathBuf; 2]> {
 pub fn get_or_default_sysroot() -> Result<PathBuf, String> {
     // Follow symlinks. If the resolved path is relative, make it absolute.
     fn canonicalize(path: PathBuf) -> PathBuf {
-        let path = fs::canonicalize(&path).unwrap_or(path);
+        let path = try_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.

compiler/rustc_session/src/utils.rs

@@ -1,5 +1,6 @@
 use crate::session::Session;
 use rustc_data_structures::profiling::VerboseTimingGuard;
+use rustc_fs_util::try_canonicalize;
 use std::path::{Path, PathBuf};
 
 impl Session {
@@ -91,7 +92,7 @@ pub struct CanonicalizedPath {
 
 impl CanonicalizedPath {
     pub fn new(path: &Path) -> Self {
-        Self { original: path.to_owned(), canonicalized: std::fs::canonicalize(path).ok() }
+        Self { original: path.to_owned(), canonicalized: try_canonicalize(path).ok() }
     }
 
     pub fn canonicalized(&self) -> &PathBuf {

compiler/rustc_target/Cargo.toml

@@ -7,6 +7,7 @@ edition = "2021"
 bitflags = "1.2.1"
 tracing = "0.1"
 serde_json = "1.0.59"
+rustc_fs_util = { path = "../rustc_fs_util" }
 rustc_abi = { path = "../rustc_abi" }
 rustc_data_structures = { path = "../rustc_data_structures" }
 rustc_feature = { path = "../rustc_feature" }

compiler/rustc_target/src/spec/mod.rs

@@ -40,6 +40,7 @@ use crate::json::{Json, ToJson};
 use crate::spec::abi::{lookup as lookup_abi, Abi};
 use crate::spec::crt_objects::{CrtObjects, LinkSelfContainedDefault};
 use rustc_data_structures::stable_hasher::{HashStable, StableHasher};
+use rustc_fs_util::try_canonicalize;
 use rustc_serialize::{Decodable, Decoder, Encodable, Encoder};
 use rustc_span::symbol::{sym, Symbol};
 use serde_json::Value;
@@ -2949,7 +2950,7 @@ impl TargetTriple {
 
     /// Creates a target triple from the passed target path.
     pub fn from_path(path: &Path) -> Result<Self, io::Error> {
-        let canonicalized_path = path.canonicalize()?;
+        let canonicalized_path = try_canonicalize(path)?;
         let contents = std::fs::read_to_string(&canonicalized_path).map_err(|err| {
             io::Error::new(
                 io::ErrorKind::InvalidInput,