Merge pull request #1253 from dtolnay/symlinks

Fix symlink paths during copy on Windows

Author: dtolnay

gen/build/src/lib.rs

@@ -369,7 +369,7 @@ fn make_crate_dir(prj: &Project) -> PathBuf {
     let crate_dir = prj.out_dir.join("cxxbridge").join("crate");
     let ref link = crate_dir.join(&prj.include_prefix);
     let ref manifest_dir = prj.manifest_dir;
-    if out::symlink_dir(manifest_dir, link).is_err() && cfg!(not(unix)) {
+    if out::relative_symlink_dir(manifest_dir, link).is_err() && cfg!(not(unix)) {
         let cachedir_tag = "\
         Signature: 8a477f597d28d172789f06886806bc55\n\
         # This file is a cache directory tag created by cxx.\n\
@@ -386,11 +386,11 @@ fn make_include_dir(prj: &Project) -> Result<PathBuf> {
     let cxx_h = include_dir.join("rust").join("cxx.h");
     let ref shared_cxx_h = prj.shared_dir.join("rust").join("cxx.h");
     if let Some(ref original) = env::var_os("DEP_CXXBRIDGE1_HEADER") {
-        out::symlink_file(original, cxx_h)?;
-        out::symlink_file(original, shared_cxx_h)?;
+        out::absolute_symlink_file(original, cxx_h)?;
+        out::absolute_symlink_file(original, shared_cxx_h)?;
     } else {
         out::write(shared_cxx_h, gen::include::HEADER.as_bytes())?;
-        out::symlink_file(shared_cxx_h, cxx_h)?;
+        out::relative_symlink_file(shared_cxx_h, cxx_h)?;
     }
     Ok(include_dir)
 }
@@ -414,7 +414,7 @@ fn generate_bridge(prj: &Project, build: &mut Build, rust_source_file: &Path) ->
     out::write(header_path, &generated.header)?;
 
     let ref link_path = include_dir.join(rel_path);
-    let _ = out::symlink_file(header_path, link_path);
+    let _ = out::relative_symlink_file(header_path, link_path);
 
     let ref rel_path_cc = rel_path.with_appended_extension(".cc");
     let ref implementation_path = sources_dir.join(rel_path_cc);
@@ -423,8 +423,8 @@ fn generate_bridge(prj: &Project, build: &mut Build, rust_source_file: &Path) ->
 
     let shared_h = prj.shared_dir.join(&prj.include_prefix).join(rel_path_h);
     let shared_cc = prj.shared_dir.join(&prj.include_prefix).join(rel_path_cc);
-    let _ = out::symlink_file(header_path, shared_h);
-    let _ = out::symlink_file(implementation_path, shared_cc);
+    let _ = out::relative_symlink_file(header_path, shared_h);
+    let _ = out::relative_symlink_file(implementation_path, shared_cc);
     Ok(())
 }
 

gen/build/src/out.rs

@@ -29,12 +29,41 @@ pub(crate) fn write(path: impl AsRef<Path>, content: &[u8]) -> Result<()> {
     }
 }
 
-pub(crate) fn symlink_file(original: impl AsRef<Path>, link: impl AsRef<Path>) -> Result<()> {
+pub(crate) fn relative_symlink_file(
+    original: impl AsRef<Path>,
+    link: impl AsRef<Path>,
+) -> Result<()> {
     let original = original.as_ref();
     let link = link.as_ref();
 
-    let original = best_effort_relativize_symlink(original, link);
+    let relativized = best_effort_relativize_symlink(original, link);
 
+    symlink_file(&relativized, original, link)
+}
+
+pub(crate) fn absolute_symlink_file(
+    original: impl AsRef<Path>,
+    link: impl AsRef<Path>,
+) -> Result<()> {
+    let original = original.as_ref();
+    let link = link.as_ref();
+
+    symlink_file(original, original, link)
+}
+
+pub(crate) fn relative_symlink_dir(
+    original: impl AsRef<Path>,
+    link: impl AsRef<Path>,
+) -> Result<()> {
+    let original = original.as_ref();
+    let link = link.as_ref();
+
+    let relativized = best_effort_relativize_symlink(original, link);
+
+    symlink_dir(&relativized, link)
+}
+
+fn symlink_file(path_for_symlink: &Path, path_for_copy: &Path, link: &Path) -> Result<()> {
     let mut create_dir_error = None;
     if fs::exists(link) {
         best_effort_remove(link);
@@ -43,7 +72,7 @@ pub(crate) fn symlink_file(original: impl AsRef<Path>, link: impl AsRef<Path>) -
         create_dir_error = fs::create_dir_all(parent).err();
     }
 
-    match paths::symlink_or_copy(original, link) {
+    match paths::symlink_or_copy(path_for_symlink, path_for_copy, link) {
         // As long as symlink_or_copy succeeded, ignore any create_dir_all error.
         Ok(()) => Ok(()),
         Err(err) => {
@@ -65,12 +94,7 @@ pub(crate) fn symlink_file(original: impl AsRef<Path>, link: impl AsRef<Path>) -
     }
 }
 
-pub(crate) fn symlink_dir(original: impl AsRef<Path>, link: impl AsRef<Path>) -> Result<()> {
-    let original = original.as_ref();
-    let link = link.as_ref();
-
-    let original = best_effort_relativize_symlink(original, link);
-
+fn symlink_dir(path_for_symlink: &Path, link: &Path) -> Result<()> {
     let mut create_dir_error = None;
     if fs::exists(link) {
         best_effort_remove(link);
@@ -79,7 +103,7 @@ pub(crate) fn symlink_dir(original: impl AsRef<Path>, link: impl AsRef<Path>) ->
         create_dir_error = fs::create_dir_all(parent).err();
     }
 
-    match fs::symlink_dir(original, link) {
+    match fs::symlink_dir(path_for_symlink, link) {
         // As long as symlink_dir succeeded, ignore any create_dir_all error.
         Ok(()) => Ok(()),
         // If create_dir_all and symlink_dir both failed, prefer the first error.

gen/build/src/paths.rs

@@ -40,28 +40,37 @@ impl PathExt for Path {
 }
 
 #[cfg(unix)]
-pub(crate) use self::fs::symlink_file as symlink_or_copy;
+pub(crate) fn symlink_or_copy(
+    path_for_symlink: impl AsRef<Path>,
+    _path_for_copy: impl AsRef<Path>,
+    link: impl AsRef<Path>,
+) -> fs::Result<()> {
+    fs::symlink_file(path_for_symlink, link)
+}
 
 #[cfg(windows)]
 pub(crate) fn symlink_or_copy(
-    original: impl AsRef<Path>,
+    path_for_symlink: impl AsRef<Path>,
+    path_for_copy: impl AsRef<Path>,
     link: impl AsRef<Path>,
 ) -> fs::Result<()> {
     // Pre-Windows 10, symlinks require admin privileges. Since Windows 10, they
     // require Developer Mode. If it fails, fall back to copying the file.
-    let original = original.as_ref();
+    let path_for_symlink = path_for_symlink.as_ref();
     let link = link.as_ref();
-    if fs::symlink_file(original, link).is_err() {
-        fs::copy(original, link)?;
+    if fs::symlink_file(path_for_symlink, link).is_err() {
+        let path_for_copy = path_for_copy.as_ref();
+        fs::copy(path_for_copy, link)?;
     }
     Ok(())
 }
 
 #[cfg(not(any(unix, windows)))]
 pub(crate) fn symlink_or_copy(
-    original: impl AsRef<Path>,
+    _path_for_symlink: impl AsRef<Path>,
+    path_for_copy: impl AsRef<Path>,
     copy: impl AsRef<Path>,
 ) -> fs::Result<()> {
-    fs::copy(original, copy)?;
+    fs::copy(path_for_copy, copy)?;
     Ok(())
 }