Auto merge of #16889 - Veykril:utf8-path, r=Veykril

internal: Enforce utf8 paths

Cargo already requires this, and I highly doubt r-a works with non-utf8 paths generally either. This just makes dealing with paths a lot easier.

46 files changed, 380 insertions, 316 deletions

diff --git a/Cargo.lock b/Cargo.lock
index 3e1c56c3563..733e119b04c 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -732,6 +732,7 @@ dependencies = [
  "ide-db",
  "itertools",
  "once_cell",
+ "paths",
  "serde_json",
  "stdx",
  "syntax",
@@ -931,6 +932,7 @@ dependencies = [
  "hir-expand",
  "ide-db",
  "itertools",
+ "paths",
  "proc-macro-api",
  "project-model",
  "span",
@@ -1225,6 +1227,9 @@ checksum = "de3145af08024dea9fa9914f381a17b8fc6034dfb00f3a84013f7ff43f29ed4c"
 [[package]]
 name = "paths"
 version = "0.0.0"
+dependencies = [
+ "camino",
+]
 
 [[package]]
 name = "percent-encoding"
@@ -1598,6 +1603,7 @@ dependencies = [
  "oorandom",
  "parking_lot",
  "parser",
+ "paths",
  "proc-macro-api",
  "profile",
  "project-model",
@@ -2020,6 +2026,7 @@ checksum = "1f3ccbac311fea05f86f61904b462b55fb3df8837a366dfc601a0161d0532f20"
 name = "toolchain"
 version = "0.0.0"
 dependencies = [
+ "camino",
  "home",
 ]
 
diff --git a/Cargo.toml b/Cargo.toml
index e9407410096..d9343d2b963 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -105,6 +105,7 @@ anyhow = "1.0.75"
 arrayvec = "0.7.4"
 bitflags = "2.4.1"
 cargo_metadata = "0.18.1"
+camino = "1.1.6"
 chalk-solve = { version = "0.96.0", default-features = false }
 chalk-ir = "0.96.0"
 chalk-recursive = { version = "0.96.0", default-features = false }
diff --git a/crates/flycheck/src/lib.rs b/crates/flycheck/src/lib.rs
index f8efb520222..4ee86954acd 100644
--- a/crates/flycheck/src/lib.rs
+++ b/crates/flycheck/src/lib.rs
@@ -8,10 +8,10 @@
 
 #![warn(rust_2018_idioms, unused_lifetimes)]
 
-use std::{fmt, io, path::PathBuf, process::Command, time::Duration};
+use std::{fmt, io, process::Command, time::Duration};
 
 use crossbeam_channel::{never, select, unbounded, Receiver, Sender};
-use paths::{AbsPath, AbsPathBuf};
+use paths::{AbsPath, AbsPathBuf, Utf8PathBuf};
 use rustc_hash::FxHashMap;
 use serde::Deserialize;
 
@@ -53,7 +53,7 @@ pub enum FlycheckConfig {
         extra_args: Vec<String>,
         extra_env: FxHashMap<String, String>,
         ansi_color_output: bool,
-        target_dir: Option<PathBuf>,
+        target_dir: Option<Utf8PathBuf>,
     },
     CustomCommand {
         command: String,
@@ -363,7 +363,7 @@ impl FlycheckActor {
                 });
 
                 cmd.arg("--manifest-path");
-                cmd.arg(self.root.join("Cargo.toml").as_os_str());
+                cmd.arg(self.root.join("Cargo.toml"));
 
                 for target in target_triples {
                     cmd.args(["--target", target.as_str()]);
diff --git a/crates/ide-diagnostics/Cargo.toml b/crates/ide-diagnostics/Cargo.toml
index 8ccea99e9e1..edd05009332 100644
--- a/crates/ide-diagnostics/Cargo.toml
+++ b/crates/ide-diagnostics/Cargo.toml
@@ -26,6 +26,7 @@ text-edit.workspace = true
 cfg.workspace = true
 hir.workspace = true
 ide-db.workspace = true
+paths.workspace = true
 
 [dev-dependencies]
 expect-test = "1.4.0"
diff --git a/crates/ide-diagnostics/src/handlers/unlinked_file.rs b/crates/ide-diagnostics/src/handlers/unlinked_file.rs
index becc24ab21e..b9327f85567 100644
--- a/crates/ide-diagnostics/src/handlers/unlinked_file.rs
+++ b/crates/ide-diagnostics/src/handlers/unlinked_file.rs
@@ -8,6 +8,7 @@ use ide_db::{
     source_change::SourceChange,
     RootDatabase,
 };
+use paths::Utf8Component;
 use syntax::{
     ast::{self, edit::IndentLevel, HasModuleItem, HasName},
     AstNode, TextRange,
@@ -84,10 +85,10 @@ fn fixes(ctx: &DiagnosticsContext<'_>, file_id: FileId) -> Option<Vec<Assist>> {
 
         // try resolving the relative difference of the paths as inline modules
         let mut current = root_module;
-        for ele in rel.as_ref().components() {
+        for ele in rel.as_utf8_path().components() {
             let seg = match ele {
-                std::path::Component::Normal(seg) => seg.to_str()?,
-                std::path::Component::RootDir => continue,
+                Utf8Component::Normal(seg) => seg,
+                Utf8Component::RootDir => continue,
                 // shouldn't occur
                 _ => continue 'crates,
             };
diff --git a/crates/ide/src/doc_links.rs b/crates/ide/src/doc_links.rs
index d10bdca50d8..64b4ccc5bd8 100644
--- a/crates/ide/src/doc_links.rs
+++ b/crates/ide/src/doc_links.rs
@@ -5,8 +5,6 @@ mod tests;
 
 mod intra_doc_links;
 
-use std::ffi::OsStr;
-
 use pulldown_cmark::{BrokenLink, CowStr, Event, InlineStr, LinkType, Options, Parser, Tag};
 use pulldown_cmark_to_cmark::{cmark_resume_with_options, Options as CMarkOptions};
 use stdx::format_to;
@@ -134,8 +132,8 @@ pub(crate) fn remove_links(markdown: &str) -> String {
 pub(crate) fn external_docs(
     db: &RootDatabase,
     FilePosition { file_id, offset }: FilePosition,
-    target_dir: Option<&OsStr>,
-    sysroot: Option<&OsStr>,
+    target_dir: Option<&str>,
+    sysroot: Option<&str>,
 ) -> Option<DocumentationLinks> {
     let sema = &Semantics::new(db);
     let file = sema.parse(file_id).syntax().clone();
@@ -331,8 +329,8 @@ fn broken_link_clone_cb(link: BrokenLink<'_>) -> Option<(CowStr<'_>, CowStr<'_>)
 fn get_doc_links(
     db: &RootDatabase,
     def: Definition,
-    target_dir: Option<&OsStr>,
-    sysroot: Option<&OsStr>,
+    target_dir: Option<&str>,
+    sysroot: Option<&str>,
 ) -> DocumentationLinks {
     let join_url = |base_url: Option<Url>, path: &str| -> Option<Url> {
         base_url.and_then(|url| url.join(path).ok())
@@ -479,15 +477,13 @@ fn map_links<'e>(
 fn get_doc_base_urls(
     db: &RootDatabase,
     def: Definition,
-    target_dir: Option<&OsStr>,
-    sysroot: Option<&OsStr>,
+    target_dir: Option<&str>,
+    sysroot: Option<&str>,
 ) -> (Option<Url>, Option<Url>) {
     let local_doc = target_dir
-        .and_then(|path| path.to_str())
         .and_then(|path| Url::parse(&format!("file:///{path}/")).ok())
         .and_then(|it| it.join("doc/").ok());
     let system_doc = sysroot
-        .and_then(|it| it.to_str())
         .map(|sysroot| format!("file:///{sysroot}/share/doc/rust/html/"))
         .and_then(|it| Url::parse(&it).ok());
 
diff --git a/crates/ide/src/doc_links/tests.rs b/crates/ide/src/doc_links/tests.rs
index 60e8d29a716..ac44908a902 100644
--- a/crates/ide/src/doc_links/tests.rs
+++ b/crates/ide/src/doc_links/tests.rs
@@ -1,4 +1,4 @@
-use std::{ffi::OsStr, iter};
+use std::iter;
 
 use expect_test::{expect, Expect};
 use hir::Semantics;
@@ -18,10 +18,10 @@ use crate::{
 
 fn check_external_docs(
     ra_fixture: &str,
-    target_dir: Option<&OsStr>,
+    target_dir: Option<&str>,
     expect_web_url: Option<Expect>,
     expect_local_url: Option<Expect>,
-    sysroot: Option<&OsStr>,
+    sysroot: Option<&str>,
 ) {
     let (analysis, position) = fixture::position(ra_fixture);
     let links = analysis.external_docs(position, target_dir, sysroot).unwrap();
@@ -127,10 +127,10 @@ fn external_docs_doc_builtin_type() {
 //- /main.rs crate:foo
 let x: u3$02 = 0;
 "#,
-        Some(OsStr::new("/home/user/project")),
+        Some("/home/user/project"),
         Some(expect![[r#"https://doc.rust-lang.org/nightly/core/primitive.u32.html"#]]),
         Some(expect![[r#"file:///sysroot/share/doc/rust/html/core/primitive.u32.html"#]]),
-        Some(OsStr::new("/sysroot")),
+        Some("/sysroot"),
     );
 }
 
@@ -143,10 +143,10 @@ use foo$0::Foo;
 //- /lib.rs crate:foo
 pub struct Foo;
 "#,
-        Some(OsStr::new("/home/user/project")),
+        Some("/home/user/project"),
         Some(expect![[r#"https://docs.rs/foo/*/foo/index.html"#]]),
         Some(expect![[r#"file:///home/user/project/doc/foo/index.html"#]]),
-        Some(OsStr::new("/sysroot")),
+        Some("/sysroot"),
     );
 }
 
@@ -157,10 +157,10 @@ fn external_docs_doc_url_std_crate() {
 //- /main.rs crate:std
 use self$0;
 "#,
-        Some(OsStr::new("/home/user/project")),
+        Some("/home/user/project"),
         Some(expect!["https://doc.rust-lang.org/stable/std/index.html"]),
         Some(expect!["file:///sysroot/share/doc/rust/html/std/index.html"]),
-        Some(OsStr::new("/sysroot")),
+        Some("/sysroot"),
     );
 }
 
@@ -171,10 +171,10 @@ fn external_docs_doc_url_struct() {
 //- /main.rs crate:foo
 pub struct Fo$0o;
 "#,
-        Some(OsStr::new("/home/user/project")),
+        Some("/home/user/project"),
         Some(expect![[r#"https://docs.rs/foo/*/foo/struct.Foo.html"#]]),
         Some(expect![[r#"file:///home/user/project/doc/foo/struct.Foo.html"#]]),
-        Some(OsStr::new("/sysroot")),
+        Some("/sysroot"),
     );
 }
 
@@ -185,10 +185,10 @@ fn external_docs_doc_url_windows_backslash_path() {
 //- /main.rs crate:foo
 pub struct Fo$0o;
 "#,
-        Some(OsStr::new(r"C:\Users\user\project")),
+        Some(r"C:\Users\user\project"),
         Some(expect![[r#"https://docs.rs/foo/*/foo/struct.Foo.html"#]]),
         Some(expect![[r#"file:///C:/Users/user/project/doc/foo/struct.Foo.html"#]]),
-        Some(OsStr::new("/sysroot")),
+        Some("/sysroot"),
     );
 }
 
@@ -199,10 +199,10 @@ fn external_docs_doc_url_windows_slash_path() {
 //- /main.rs crate:foo
 pub struct Fo$0o;
 "#,
-        Some(OsStr::new(r"C:/Users/user/project")),
+        Some("C:/Users/user/project"),
         Some(expect![[r#"https://docs.rs/foo/*/foo/struct.Foo.html"#]]),
         Some(expect![[r#"file:///C:/Users/user/project/doc/foo/struct.Foo.html"#]]),
-        Some(OsStr::new("/sysroot")),
+        Some("/sysroot"),
     );
 }
 
diff --git a/crates/ide/src/lib.rs b/crates/ide/src/lib.rs
index 1c57f4f8f63..11eaa88c5c4 100644
--- a/crates/ide/src/lib.rs
+++ b/crates/ide/src/lib.rs
@@ -58,8 +58,6 @@ mod view_item_tree;
 mod view_memory_layout;
 mod view_mir;
 
-use std::ffi::OsStr;
-
 use cfg::CfgOptions;
 use fetch_crates::CrateInfo;
 use hir::ChangeWithProcMacros;
@@ -511,8 +509,8 @@ impl Analysis {
     pub fn external_docs(
         &self,
         position: FilePosition,
-        target_dir: Option<&OsStr>,
-        sysroot: Option<&OsStr>,
+        target_dir: Option<&str>,
+        sysroot: Option<&str>,
     ) -> Cancellable<doc_links::DocumentationLinks> {
         self.with_db(|db| {
             doc_links::external_docs(db, position, target_dir, sysroot).unwrap_or_default()
diff --git a/crates/load-cargo/Cargo.toml b/crates/load-cargo/Cargo.toml
index 05412e176b6..48e84a7b25e 100644
--- a/crates/load-cargo/Cargo.toml
+++ b/crates/load-cargo/Cargo.toml
@@ -20,6 +20,7 @@ tracing.workspace = true
 
 hir-expand.workspace = true
 ide-db.workspace = true
+paths.workspace = true
 proc-macro-api.workspace = true
 project-model.workspace = true
 span.workspace = true
diff --git a/crates/load-cargo/src/lib.rs b/crates/load-cargo/src/lib.rs
index fe680e47fef..bb88500a0f0 100644
--- a/crates/load-cargo/src/lib.rs
+++ b/crates/load-cargo/src/lib.rs
@@ -38,7 +38,7 @@ pub fn load_workspace_at(
     load_config: &LoadCargoConfig,
     progress: &dyn Fn(String),
 ) -> anyhow::Result<(RootDatabase, vfs::Vfs, Option<ProcMacroServer>)> {
-    let root = AbsPathBuf::assert(std::env::current_dir()?.join(root));
+    let root = AbsPathBuf::assert_utf8(std::env::current_dir()?.join(root));
     let root = ProjectManifest::discover_single(&root)?;
     let mut workspace = ProjectWorkspace::load(root, cargo_config, progress)?;
 
diff --git a/crates/paths/Cargo.toml b/crates/paths/Cargo.toml
index 3d8752b5a82..59a4ad9a255 100644
--- a/crates/paths/Cargo.toml
+++ b/crates/paths/Cargo.toml
@@ -12,10 +12,14 @@ rust-version.workspace = true
 doctest = false
 
 [dependencies]
+camino.workspace = true
 # Adding this dep sadly puts a lot of rust-analyzer crates after the
 # serde-derive crate. Even though we don't activate the derive feature here,
 # someone else in the crate graph certainly does!
 # serde.workspace = true
 
+[features]
+serde1 = ["camino/serde1"]
+
 [lints]
-workspace = true
\ No newline at end of file
+workspace = true
diff --git a/crates/paths/src/lib.rs b/crates/paths/src/lib.rs
index a63d251c20d..3ffe4e11e96 100644
--- a/crates/paths/src/lib.rs
+++ b/crates/paths/src/lib.rs
@@ -1,4 +1,4 @@
-//! Thin wrappers around `std::path`, distinguishing between absolute and
+//! Thin wrappers around `std::path`/`camino::path`, distinguishing between absolute and
 //! relative paths.
 
 #![warn(rust_2018_idioms, unused_lifetimes)]
@@ -7,16 +7,24 @@ use std::{
     borrow::Borrow,
     ffi::OsStr,
     fmt, ops,
-    path::{Component, Path, PathBuf},
+    path::{Path, PathBuf},
 };
 
-/// Wrapper around an absolute [`PathBuf`].
+pub use camino::*;
+
+/// Wrapper around an absolute [`Utf8PathBuf`].
 #[derive(Debug, Clone, Ord, PartialOrd, Eq, PartialEq, Hash)]
-pub struct AbsPathBuf(PathBuf);
+pub struct AbsPathBuf(Utf8PathBuf);
+
+impl From<AbsPathBuf> for Utf8PathBuf {
+    fn from(AbsPathBuf(path_buf): AbsPathBuf) -> Utf8PathBuf {
+        path_buf
+    }
+}
 
 impl From<AbsPathBuf> for PathBuf {
     fn from(AbsPathBuf(path_buf): AbsPathBuf) -> PathBuf {
-        path_buf
+        path_buf.into()
     }
 }
 
@@ -27,9 +35,21 @@ impl ops::Deref for AbsPathBuf {
     }
 }
 
+impl AsRef<Utf8Path> for AbsPathBuf {
+    fn as_ref(&self) -> &Utf8Path {
+        self.0.as_path()
+    }
+}
+
+impl AsRef<OsStr> for AbsPathBuf {
+    fn as_ref(&self) -> &OsStr {
+        self.0.as_ref()
+    }
+}
+
 impl AsRef<Path> for AbsPathBuf {
     fn as_ref(&self) -> &Path {
-        self.0.as_path()
+        self.0.as_ref()
     }
 }
 
@@ -45,20 +65,30 @@ impl Borrow<AbsPath> for AbsPathBuf {
     }
 }
 
+impl TryFrom<Utf8PathBuf> for AbsPathBuf {
+    type Error = Utf8PathBuf;
+    fn try_from(path_buf: Utf8PathBuf) -> Result<AbsPathBuf, Utf8PathBuf> {
+        if !path_buf.is_absolute() {
+            return Err(path_buf);
+        }
+        Ok(AbsPathBuf(path_buf))
+    }
+}
+
 impl TryFrom<PathBuf> for AbsPathBuf {
     type Error = PathBuf;
     fn try_from(path_buf: PathBuf) -> Result<AbsPathBuf, PathBuf> {
         if !path_buf.is_absolute() {
             return Err(path_buf);
         }
-        Ok(AbsPathBuf(path_buf))
+        Ok(AbsPathBuf(Utf8PathBuf::from_path_buf(path_buf)?))
     }
 }
 
 impl TryFrom<&str> for AbsPathBuf {
-    type Error = PathBuf;
-    fn try_from(path: &str) -> Result<AbsPathBuf, PathBuf> {
-        AbsPathBuf::try_from(PathBuf::from(path))
+    type Error = Utf8PathBuf;
+    fn try_from(path: &str) -> Result<AbsPathBuf, Utf8PathBuf> {
+        AbsPathBuf::try_from(Utf8PathBuf::from(path))
     }
 }
 
@@ -74,19 +104,31 @@ impl AbsPathBuf {
     /// # Panics
     ///
     /// Panics if `path` is not absolute.
-    pub fn assert(path: PathBuf) -> AbsPathBuf {
+    pub fn assert(path: Utf8PathBuf) -> AbsPathBuf {
         AbsPathBuf::try_from(path)
-            .unwrap_or_else(|path| panic!("expected absolute path, got {}", path.display()))
+            .unwrap_or_else(|path| panic!("expected absolute path, got {}", path))
+    }
+
+    /// Wrap the given absolute path in `AbsPathBuf`
+    ///
+    /// # Panics
+    ///
+    /// Panics if `path` is not absolute.
+    pub fn assert_utf8(path: PathBuf) -> AbsPathBuf {
+        AbsPathBuf::assert(
+            Utf8PathBuf::from_path_buf(path)
+                .unwrap_or_else(|path| panic!("expected utf8 path, got {}", path.display())),
+        )
     }
 
     /// Coerces to an `AbsPath` slice.
     ///
-    /// Equivalent of [`PathBuf::as_path`] for `AbsPathBuf`.
+    /// Equivalent of [`Utf8PathBuf::as_path`] for `AbsPathBuf`.
     pub fn as_path(&self) -> &AbsPath {
         AbsPath::assert(self.0.as_path())
     }
 
-    /// Equivalent of [`PathBuf::pop`] for `AbsPathBuf`.
+    /// Equivalent of [`Utf8PathBuf::pop`] for `AbsPathBuf`.
     ///
     /// Note that this won't remove the root component, so `self` will still be
     /// absolute.
@@ -97,18 +139,30 @@ impl AbsPathBuf {
 
 impl fmt::Display for AbsPathBuf {
     fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
-        fmt::Display::fmt(&self.0.display(), f)
+        fmt::Display::fmt(&self.0, f)
     }
 }
 
-/// Wrapper around an absolute [`Path`].
+/// Wrapper around an absolute [`Utf8Path`].
 #[derive(Debug, Ord, PartialOrd, Eq, PartialEq, Hash)]
 #[repr(transparent)]
-pub struct AbsPath(Path);
+pub struct AbsPath(Utf8Path);
+
+impl AsRef<Utf8Path> for AbsPath {
+    fn as_ref(&self) -> &Utf8Path {
+        &self.0
+    }
+}
 
 impl AsRef<Path> for AbsPath {
     fn as_ref(&self) -> &Path {
-        &self.0
+        self.0.as_ref()
+    }
+}
+
+impl AsRef<OsStr> for AbsPath {
+    fn as_ref(&self) -> &OsStr {
+        self.0.as_ref()
     }
 }
 
@@ -120,9 +174,9 @@ impl ToOwned for AbsPath {
     }
 }
 
-impl<'a> TryFrom<&'a Path> for &'a AbsPath {
-    type Error = &'a Path;
-    fn try_from(path: &'a Path) -> Result<&'a AbsPath, &'a Path> {
+impl<'a> TryFrom<&'a Utf8Path> for &'a AbsPath {
+    type Error = &'a Utf8Path;
+    fn try_from(path: &'a Utf8Path) -> Result<&'a AbsPath, &'a Utf8Path> {
         if !path.is_absolute() {
             return Err(path);
         }
@@ -136,24 +190,24 @@ impl AbsPath {
     /// # Panics
     ///
     /// Panics if `path` is not absolute.
-    pub fn assert(path: &Path) -> &AbsPath {
+    pub fn assert(path: &Utf8Path) -> &AbsPath {
         assert!(path.is_absolute());
-        unsafe { &*(path as *const Path as *const AbsPath) }
+        unsafe { &*(path as *const Utf8Path as *const AbsPath) }
     }
 
-    /// Equivalent of [`Path::parent`] for `AbsPath`.
+    /// Equivalent of [`Utf8Path::parent`] for `AbsPath`.
     pub fn parent(&self) -> Option<&AbsPath> {
         self.0.parent().map(AbsPath::assert)
     }
 
-    /// Equivalent of [`Path::join`] for `AbsPath` with an additional normalize step afterwards.
-    pub fn absolutize(&self, path: impl AsRef<Path>) -> AbsPathBuf {
+    /// Equivalent of [`Utf8Path::join`] for `AbsPath` with an additional normalize step afterwards.
+    pub fn absolutize(&self, path: impl AsRef<Utf8Path>) -> AbsPathBuf {
         self.join(path).normalize()
     }
 
-    /// Equivalent of [`Path::join`] for `AbsPath`.
-    pub fn join(&self, path: impl AsRef<Path>) -> AbsPathBuf {
-        self.as_ref().join(path).try_into().unwrap()
+    /// Equivalent of [`Utf8Path::join`] for `AbsPath`.
+    pub fn join(&self, path: impl AsRef<Utf8Path>) -> AbsPathBuf {
+        Utf8Path::join(self.as_ref(), path).try_into().unwrap()
     }
 
     /// Normalize the given path:
@@ -172,7 +226,7 @@ impl AbsPath {
         AbsPathBuf(normalize_path(&self.0))
     }
 
-    /// Equivalent of [`Path::to_path_buf`] for `AbsPath`.
+    /// Equivalent of [`Utf8Path::to_path_buf`] for `AbsPath`.
     pub fn to_path_buf(&self) -> AbsPathBuf {
         AbsPathBuf::try_from(self.0.to_path_buf()).unwrap()
     }
@@ -181,7 +235,7 @@ impl AbsPath {
         panic!("We explicitly do not provide canonicalization API, as that is almost always a wrong solution, see #14430")
     }
 
-    /// Equivalent of [`Path::strip_prefix`] for `AbsPath`.
+    /// Equivalent of [`Utf8Path::strip_prefix`] for `AbsPath`.
     ///
     /// Returns a relative path.
     pub fn strip_prefix(&self, base: &AbsPath) -> Option<&RelPath> {
@@ -195,57 +249,61 @@ impl AbsPath {
     }
 
     pub fn name_and_extension(&self) -> Option<(&str, Option<&str>)> {
-        Some((
-            self.file_stem()?.to_str()?,
-            self.extension().and_then(|extension| extension.to_str()),
-        ))
+        Some((self.file_stem()?, self.extension()))
     }
 
     // region:delegate-methods
 
-    // Note that we deliberately don't implement `Deref<Target = Path>` here.
+    // Note that we deliberately don't implement `Deref<Target = Utf8Path>` here.
     //
-    // The problem with `Path` is that it directly exposes convenience IO-ing
-    // methods. For example, `Path::exists` delegates to `fs::metadata`.
+    // The problem with `Utf8Path` is that it directly exposes convenience IO-ing
+    // methods. For example, `Utf8Path::exists` delegates to `fs::metadata`.
     //
     // For `AbsPath`, we want to make sure that this is a POD type, and that all
     // IO goes via `fs`. That way, it becomes easier to mock IO when we need it.
 
-    pub fn file_name(&self) -> Option<&OsStr> {
+    pub fn file_name(&self) -> Option<&str> {
         self.0.file_name()
     }
-    pub fn extension(&self) -> Option<&OsStr> {
+    pub fn extension(&self) -> Option<&str> {
         self.0.extension()
     }
-    pub fn file_stem(&self) -> Option<&OsStr> {
+    pub fn file_stem(&self) -> Option<&str> {
         self.0.file_stem()
     }
     pub fn as_os_str(&self) -> &OsStr {
         self.0.as_os_str()
     }
+    pub fn as_str(&self) -> &str {
+        self.0.as_str()
+    }
     #[deprecated(note = "use Display instead")]
-    pub fn display(&self) -> std::path::Display<'_> {
-        self.0.display()
+    pub fn display(&self) -> ! {
+        unimplemented!()
     }
     #[deprecated(note = "use std::fs::metadata().is_ok() instead")]
-    pub fn exists(&self) -> bool {
-        self.0.exists()
+    pub fn exists(&self) -> ! {
+        unimplemented!()
+    }
+
+    pub fn components(&self) -> Utf8Components<'_> {
+        self.0.components()
     }
     // endregion:delegate-methods
 }
 
 impl fmt::Display for AbsPath {
     fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
-        fmt::Display::fmt(&self.0.display(), f)
+        fmt::Display::fmt(&self.0, f)
     }
 }
 
-/// Wrapper around a relative [`PathBuf`].
+/// Wrapper around a relative [`Utf8PathBuf`].
 #[derive(Debug, Clone, Ord, PartialOrd, Eq, PartialEq, Hash)]
-pub struct RelPathBuf(PathBuf);
+pub struct RelPathBuf(Utf8PathBuf);
 
-impl From<RelPathBuf> for PathBuf {
-    fn from(RelPathBuf(path_buf): RelPathBuf) -> PathBuf {
+impl From<RelPathBuf> for Utf8PathBuf {
+    fn from(RelPathBuf(path_buf): RelPathBuf) -> Utf8PathBuf {
         path_buf
     }
 }
@@ -257,15 +315,21 @@ impl ops::Deref for RelPathBuf {
     }
 }
 
+impl AsRef<Utf8Path> for RelPathBuf {
+    fn as_ref(&self) -> &Utf8Path {
+        self.0.as_path()
+    }
+}
+
 impl AsRef<Path> for RelPathBuf {
     fn as_ref(&self) -> &Path {
-        self.0.as_path()
+        self.0.as_ref()
     }
 }
 
-impl TryFrom<PathBuf> for RelPathBuf {
-    type Error = PathBuf;
-    fn try_from(path_buf: PathBuf) -> Result<RelPathBuf, PathBuf> {
+impl TryFrom<Utf8PathBuf> for RelPathBuf {
+    type Error = Utf8PathBuf;
+    fn try_from(path_buf: Utf8PathBuf) -> Result<RelPathBuf, Utf8PathBuf> {
         if !path_buf.is_relative() {
             return Err(path_buf);
         }
@@ -274,65 +338,79 @@ impl TryFrom<PathBuf> for RelPathBuf {
 }
 
 impl TryFrom<&str> for RelPathBuf {
-    type Error = PathBuf;
-    fn try_from(path: &str) -> Result<RelPathBuf, PathBuf> {
-        RelPathBuf::try_from(PathBuf::from(path))
+    type Error = Utf8PathBuf;
+    fn try_from(path: &str) -> Result<RelPathBuf, Utf8PathBuf> {
+        RelPathBuf::try_from(Utf8PathBuf::from(path))
     }
 }
 
 impl RelPathBuf {
     /// Coerces to a `RelPath` slice.
     ///
-    /// Equivalent of [`PathBuf::as_path`] for `RelPathBuf`.
+    /// Equivalent of [`Utf8PathBuf::as_path`] for `RelPathBuf`.
     pub fn as_path(&self) -> &RelPath {
         RelPath::new_unchecked(self.0.as_path())
     }
 }
 
-/// Wrapper around a relative [`Path`].
+/// Wrapper around a relative [`Utf8Path`].
 #[derive(Debug, Ord, PartialOrd, Eq, PartialEq, Hash)]
 #[repr(transparent)]
-pub struct RelPath(Path);
+pub struct RelPath(Utf8Path);
+
+impl AsRef<Utf8Path> for RelPath {
+    fn as_ref(&self) -> &Utf8Path {
+        &self.0
+    }
+}
 
 impl AsRef<Path> for RelPath {
     fn as_ref(&self) -> &Path {
-        &self.0
+        self.0.as_ref()
     }
 }
 
 impl RelPath {
     /// Creates a new `RelPath` from `path`, without checking if it is relative.
-    pub fn new_unchecked(path: &Path) -> &RelPath {
-        unsafe { &*(path as *const Path as *const RelPath) }
+    pub fn new_unchecked(path: &Utf8Path) -> &RelPath {
+        unsafe { &*(path as *const Utf8Path as *const RelPath) }
     }
 
-    /// Equivalent of [`Path::to_path_buf`] for `RelPath`.
+    /// Equivalent of [`Utf8Path::to_path_buf`] for `RelPath`.
     pub fn to_path_buf(&self) -> RelPathBuf {
         RelPathBuf::try_from(self.0.to_path_buf()).unwrap()
     }
+
+    pub fn as_utf8_path(&self) -> &Utf8Path {
+        self.as_ref()
+    }
+
+    pub fn as_str(&self) -> &str {
+        self.0.as_str()
+    }
 }
 
 /// Taken from <https://github.com/rust-lang/cargo/blob/79c769c3d7b4c2cf6a93781575b7f592ef974255/src/cargo/util/paths.rs#L60-L85>
-fn normalize_path(path: &Path) -> PathBuf {
+fn normalize_path(path: &Utf8Path) -> Utf8PathBuf {
     let mut components = path.components().peekable();
-    let mut ret = if let Some(c @ Component::Prefix(..)) = components.peek().copied() {
+    let mut ret = if let Some(c @ Utf8Component::Prefix(..)) = components.peek().copied() {
         components.next();
-        PathBuf::from(c.as_os_str())
+        Utf8PathBuf::from(c.as_str())
     } else {
-        PathBuf::new()
+        Utf8PathBuf::new()
     };
 
     for component in components {
         match component {
-            Component::Prefix(..) => unreachable!(),
-            Component::RootDir => {
-                ret.push(component.as_os_str());
+            Utf8Component::Prefix(..) => unreachable!(),
+            Utf8Component::RootDir => {
+                ret.push(component.as_str());
             }
-            Component::CurDir => {}
-            Component::ParentDir => {
+            Utf8Component::CurDir => {}
+            Utf8Component::ParentDir => {
                 ret.pop();
             }
-            Component::Normal(c) => {
+            Utf8Component::Normal(c) => {
                 ret.push(c);
             }
         }
diff --git a/crates/proc-macro-api/Cargo.toml b/crates/proc-macro-api/Cargo.toml
index 978ad155609..f30f6a0f23b 100644
--- a/crates/proc-macro-api/Cargo.toml
+++ b/crates/proc-macro-api/Cargo.toml
@@ -23,7 +23,7 @@ snap = "1.1.0"
 indexmap = "2.1.0"
 
 # local deps
-paths.workspace = true
+paths = { workspace = true, features = ["serde1"] }
 tt.workspace = true
 stdx.workspace = true
 text-size.workspace = true
diff --git a/crates/proc-macro-api/src/msg.rs b/crates/proc-macro-api/src/msg.rs
index aa5aff455fd..ad0e1f187b6 100644
--- a/crates/proc-macro-api/src/msg.rs
+++ b/crates/proc-macro-api/src/msg.rs
@@ -1,11 +1,9 @@
 //! Defines messages for cross-process message passing based on `ndjson` wire protocol
 pub(crate) mod flat;
 
-use std::{
-    io::{self, BufRead, Write},
-    path::PathBuf,
-};
+use std::io::{self, BufRead, Write};
 
+use paths::Utf8PathBuf;
 use serde::{de::DeserializeOwned, Deserialize, Serialize};
 
 use crate::ProcMacroKind;
@@ -27,7 +25,7 @@ pub const CURRENT_API_VERSION: u32 = RUST_ANALYZER_SPAN_SUPPORT;
 #[derive(Debug, Serialize, Deserialize)]
 pub enum Request {
     /// Since [`NO_VERSION_CHECK_VERSION`]
-    ListMacros { dylib_path: PathBuf },
+    ListMacros { dylib_path: Utf8PathBuf },
     /// Since [`NO_VERSION_CHECK_VERSION`]
     ExpandMacro(Box<ExpandMacro>),
     /// Since [`VERSION_CHECK_VERSION`]
@@ -89,7 +87,7 @@ pub struct ExpandMacro {
     /// Possible attributes for the attribute-like macros.
     pub attributes: Option<FlatTree>,
 
-    pub lib: PathBuf,
+    pub lib: Utf8PathBuf,
 
     /// Environment variables to set during macro expansion.
     pub env: Vec<(String, String)>,
@@ -273,7 +271,7 @@ mod tests {
             macro_body: FlatTree::new(&tt, CURRENT_API_VERSION, &mut span_data_table),
             macro_name: Default::default(),
             attributes: None,
-            lib: std::env::current_dir().unwrap(),
+            lib: Utf8PathBuf::from_path_buf(std::env::current_dir().unwrap()).unwrap(),
             env: Default::default(),
             current_dir: Default::default(),
             has_global_spans: ExpnGlobals {
diff --git a/crates/proc-macro-api/src/process.rs b/crates/proc-macro-api/src/process.rs
index 72f95643c8b..35d48a15543 100644
--- a/crates/proc-macro-api/src/process.rs
+++ b/crates/proc-macro-api/src/process.rs
@@ -175,7 +175,7 @@ fn mk_child(
     env: &FxHashMap<String, String>,
     null_stderr: bool,
 ) -> io::Result<Child> {
-    let mut cmd = Command::new(path.as_os_str());
+    let mut cmd = Command::new(path);
     cmd.envs(env)
         .env("RUST_ANALYZER_INTERNALS_DO_NOT_USE", "this is unstable")
         .stdin(Stdio::piped())
@@ -183,7 +183,7 @@ fn mk_child(
         .stderr(if null_stderr { Stdio::null() } else { Stdio::inherit() });
     if cfg!(windows) {
         let mut path_var = std::ffi::OsString::new();
-        path_var.push(path.parent().unwrap().parent().unwrap().as_os_str());
+        path_var.push(path.parent().unwrap().parent().unwrap());
         path_var.push("\\bin;");
         path_var.push(std::env::var_os("PATH").unwrap_or_default());
         cmd.env("PATH", path_var);
diff --git a/crates/proc-macro-srv/src/dylib.rs b/crates/proc-macro-srv/src/dylib.rs
index 52b4cced5f5..22c34ff1678 100644
--- a/crates/proc-macro-srv/src/dylib.rs
+++ b/crates/proc-macro-srv/src/dylib.rs
@@ -1,16 +1,11 @@
 //! Handles dynamic library loading for proc macro
 
-use std::{
-    fmt,
-    fs::File,
-    io,
-    path::{Path, PathBuf},
-};
+use std::{fmt, fs::File, io};
 
 use libloading::Library;
 use memmap2::Mmap;
 use object::Object;
-use paths::AbsPath;
+use paths::{AbsPath, Utf8Path, Utf8PathBuf};
 use proc_macro::bridge;
 use proc_macro_api::{read_dylib_info, ProcMacroKind};
 
@@ -26,7 +21,7 @@ fn is_derive_registrar_symbol(symbol: &str) -> bool {
     symbol.contains(NEW_REGISTRAR_SYMBOL)
 }
 
-fn find_registrar_symbol(file: &Path) -> io::Result<Option<String>> {
+fn find_registrar_symbol(file: &Utf8Path) -> io::Result<Option<String>> {
     let file = File::open(file)?;
     let buffer = unsafe { Mmap::map(&file)? };
 
@@ -62,12 +57,12 @@ fn find_registrar_symbol(file: &Path) -> io::Result<Option<String>> {
 ///
 /// It seems that on Windows that behaviour is default, so we do nothing in that case.
 #[cfg(windows)]
-fn load_library(file: &Path) -> Result<Library, libloading::Error> {
+fn load_library(file: &Utf8Path) -> Result<Library, libloading::Error> {
     unsafe { Library::new(file) }
 }
 
 #[cfg(unix)]
-fn load_library(file: &Path) -> Result<Library, libloading::Error> {
+fn load_library(file: &Utf8Path) -> Result<Library, libloading::Error> {
     use libloading::os::unix::Library as UnixLibrary;
     use std::os::raw::c_int;
 
@@ -116,14 +111,14 @@ struct ProcMacroLibraryLibloading {
 }
 
 impl ProcMacroLibraryLibloading {
-    fn open(file: &Path) -> Result<Self, LoadProcMacroDylibError> {
+    fn open(file: &Utf8Path) -> Result<Self, LoadProcMacroDylibError> {
         let symbol_name = find_registrar_symbol(file)?.ok_or_else(|| {
-            invalid_data_err(format!("Cannot find registrar symbol in file {}", file.display()))
+            invalid_data_err(format!("Cannot find registrar symbol in file {file}"))
         })?;
 
-        let abs_file: &AbsPath = file.try_into().map_err(|_| {
-            invalid_data_err(format!("expected an absolute path, got {}", file.display()))
-        })?;
+        let abs_file: &AbsPath = file
+            .try_into()
+            .map_err(|_| invalid_data_err(format!("expected an absolute path, got {file}")))?;
         let version_info = read_dylib_info(abs_file)?;
 
         let lib = load_library(file).map_err(invalid_data_err)?;
@@ -138,10 +133,10 @@ pub struct Expander {
 }
 
 impl Expander {
-    pub fn new(lib: &Path) -> Result<Expander, LoadProcMacroDylibError> {
+    pub fn new(lib: &Utf8Path) -> Result<Expander, LoadProcMacroDylibError> {
         // Some libraries for dynamic loading require canonicalized path even when it is
         // already absolute
-        let lib = lib.canonicalize()?;
+        let lib = lib.canonicalize_utf8()?;
 
         let lib = ensure_file_with_lock_free_access(&lib)?;
 
@@ -176,30 +171,26 @@ impl Expander {
 
 /// Copy the dylib to temp directory to prevent locking in Windows
 #[cfg(windows)]
-fn ensure_file_with_lock_free_access(path: &Path) -> io::Result<PathBuf> {
+fn ensure_file_with_lock_free_access(path: &Utf8Path) -> io::Result<Utf8PathBuf> {
     use std::collections::hash_map::RandomState;
-    use std::ffi::OsString;
     use std::hash::{BuildHasher, Hasher};
 
     if std::env::var("RA_DONT_COPY_PROC_MACRO_DLL").is_ok() {
         return Ok(path.to_path_buf());
     }
 
-    let mut to = std::env::temp_dir();
+    let mut to = Utf8PathBuf::from_path_buf(std::env::temp_dir()).unwrap();
 
     let file_name = path.file_name().ok_or_else(|| {
-        io::Error::new(
-            io::ErrorKind::InvalidInput,
-            format!("File path is invalid: {}", path.display()),
-        )
+        io::Error::new(io::ErrorKind::InvalidInput, format!("File path is invalid: {path}"))
     })?;
 
     // Generate a unique number by abusing `HashMap`'s hasher.
     // Maybe this will also "inspire" a libs team member to finally put `rand` in libstd.
     let t = RandomState::new().build_hasher().finish();
 
-    let mut unique_name = OsString::from(t.to_string());
-    unique_name.push(file_name);
+    let mut unique_name = t.to_string();
+    unique_name.push_str(file_name);
 
     to.push(unique_name);
     std::fs::copy(path, &to).unwrap();
@@ -207,6 +198,6 @@ fn ensure_file_with_lock_free_access(path: &Path) -> io::Result<PathBuf> {
 }
 
 #[cfg(unix)]
-fn ensure_file_with_lock_free_access(path: &Path) -> io::Result<PathBuf> {
-    Ok(path.to_path_buf())
+fn ensure_file_with_lock_free_access(path: &Utf8Path) -> io::Result<Utf8PathBuf> {
+    Ok(path.to_owned())
 }
diff --git a/crates/proc-macro-srv/src/lib.rs b/crates/proc-macro-srv/src/lib.rs
index 831632c64c0..d7e0a708b1f 100644
--- a/crates/proc-macro-srv/src/lib.rs
+++ b/crates/proc-macro-srv/src/lib.rs
@@ -33,12 +33,11 @@ use std::{
     collections::{hash_map::Entry, HashMap},
     env,
     ffi::OsString,
-    fs,
-    path::{Path, PathBuf},
-    thread,
+    fs, thread,
     time::SystemTime,
 };
 
+use paths::{Utf8Path, Utf8PathBuf};
 use proc_macro_api::{
     msg::{
         self, deserialize_span_data_index_map, serialize_span_data_index_map, ExpnGlobals,
@@ -81,7 +80,7 @@ impl ProcMacroSrvSpan for Span {
 
 #[derive(Default)]
 pub struct ProcMacroSrv {
-    expanders: HashMap<(PathBuf, SystemTime), dylib::Expander>,
+    expanders: HashMap<(Utf8PathBuf, SystemTime), dylib::Expander>,
     span_mode: SpanMode,
 }
 
@@ -149,23 +148,22 @@ impl ProcMacroSrv {
 
     pub fn list_macros(
         &mut self,
-        dylib_path: &Path,
+        dylib_path: &Utf8Path,
     ) -> Result<Vec<(String, ProcMacroKind)>, String> {
         let expander = self.expander(dylib_path)?;
         Ok(expander.list_macros())
     }
 
-    fn expander(&mut self, path: &Path) -> Result<&dylib::Expander, String> {
+    fn expander(&mut self, path: &Utf8Path) -> Result<&dylib::Expander, String> {
         let time = fs::metadata(path)
             .and_then(|it| it.modified())
-            .map_err(|err| format!("Failed to get file metadata for {}: {err}", path.display()))?;
+            .map_err(|err| format!("Failed to get file metadata for {path}: {err}",))?;
 
         Ok(match self.expanders.entry((path.to_path_buf(), time)) {
-            Entry::Vacant(v) => {
-                v.insert(dylib::Expander::new(path).map_err(|err| {
-                    format!("Cannot create expander for {}: {err}", path.display())
-                })?)
-            }
+            Entry::Vacant(v) => v.insert(
+                dylib::Expander::new(path)
+                    .map_err(|err| format!("Cannot create expander for {path}: {err}",))?,
+            ),
             Entry::Occupied(e) => e.into_mut(),
         })
     }
@@ -306,6 +304,6 @@ impl Drop for EnvSnapshot {
 mod tests;
 
 #[cfg(test)]
-pub fn proc_macro_test_dylib_path() -> std::path::PathBuf {
+pub fn proc_macro_test_dylib_path() -> paths::Utf8PathBuf {
     proc_macro_test::PROC_MACRO_TEST_LOCATION.into()
 }
diff --git a/crates/project-model/Cargo.toml b/crates/project-model/Cargo.toml
index 924a4a89e21..139689975d7 100644
--- a/crates/project-model/Cargo.toml
+++ b/crates/project-model/Cargo.toml
@@ -26,7 +26,7 @@ itertools.workspace = true
 # local deps
 base-db.workspace = true
 cfg.workspace = true
-paths.workspace = true
+paths = { workspace = true, features = ["serde1"] }
 stdx.workspace = true
 toolchain.workspace = true
 
diff --git a/crates/project-model/src/build_scripts.rs b/crates/project-model/src/build_scripts.rs
index 709fc037174..d40eb26063d 100644
--- a/crates/project-model/src/build_scripts.rs
+++ b/crates/project-model/src/build_scripts.rs
@@ -77,7 +77,7 @@ impl WorkspaceBuildScripts {
                 cmd.args(&config.extra_args);
 
                 cmd.arg("--manifest-path");
-                cmd.arg(workspace_root.join("Cargo.toml").as_os_str());
+                cmd.arg(workspace_root.join("Cargo.toml"));
 
                 if let Some(target_dir) = &config.target_dir {
                     cmd.arg("--target-dir").arg(target_dir);
@@ -354,16 +354,11 @@ impl WorkspaceBuildScripts {
                             }
                             // cargo_metadata crate returns default (empty) path for
                             // older cargos, which is not absolute, so work around that.
-                            let out_dir = mem::take(&mut message.out_dir).into_os_string();
-                            if !out_dir.is_empty() {
-                                let out_dir = AbsPathBuf::assert(PathBuf::from(out_dir));
+                            let out_dir = mem::take(&mut message.out_dir);
+                            if !out_dir.as_str().is_empty() {
+                                let out_dir = AbsPathBuf::assert(out_dir);
                                 // inject_cargo_env(package, package_build_data);
-                                // NOTE: cargo and rustc seem to hide non-UTF-8 strings from env! and option_env!()
-                                if let Some(out_dir) =
-                                    out_dir.as_os_str().to_str().map(|s| s.to_owned())
-                                {
-                                    data.envs.push(("OUT_DIR".to_owned(), out_dir));
-                                }
+                                data.envs.push(("OUT_DIR".to_owned(), out_dir.as_str().to_owned()));
                                 data.out_dir = Some(out_dir);
                                 data.cfgs = cfgs;
                             }
@@ -377,8 +372,8 @@ impl WorkspaceBuildScripts {
                                 if let Some(filename) =
                                     message.filenames.iter().find(|name| is_dylib(name))
                                 {
-                                    let filename = AbsPathBuf::assert(PathBuf::from(&filename));
-                                    data.proc_macro_dylib_path = Some(filename);
+                                    let filename = AbsPath::assert(filename);
+                                    data.proc_macro_dylib_path = Some(filename.to_owned());
                                 }
                             }
                         });
diff --git a/crates/project-model/src/cargo_workspace.rs b/crates/project-model/src/cargo_workspace.rs
index 53b41ea1e87..4f6bac08f69 100644
--- a/crates/project-model/src/cargo_workspace.rs
+++ b/crates/project-model/src/cargo_workspace.rs
@@ -1,14 +1,13 @@
 //! See [`CargoWorkspace`].
 
 use std::ops;
-use std::path::PathBuf;
 use std::str::from_utf8;
 
 use anyhow::Context;
 use base_db::Edition;
 use cargo_metadata::{CargoOpt, MetadataCommand};
 use la_arena::{Arena, Idx};
-use paths::{AbsPath, AbsPathBuf};
+use paths::{AbsPath, AbsPathBuf, Utf8PathBuf};
 use rustc_hash::{FxHashMap, FxHashSet};
 use serde::Deserialize;
 use serde_json::from_value;
@@ -100,7 +99,7 @@ pub struct CargoConfig {
     pub invocation_strategy: InvocationStrategy,
     pub invocation_location: InvocationLocation,
     /// Optional path to use instead of `target` when building
-    pub target_dir: Option<PathBuf>,
+    pub target_dir: Option<Utf8PathBuf>,
 }
 
 pub type Package = Idx<PackageData>;
@@ -262,7 +261,7 @@ impl CargoWorkspace {
                 }
             }
         }
-        meta.current_dir(current_dir.as_os_str());
+        meta.current_dir(current_dir);
 
         let mut other_options = vec![];
         // cargo metadata only supports a subset of flags of what cargo usually accepts, and usually
@@ -351,7 +350,7 @@ impl CargoWorkspace {
                 id: id.repr.clone(),
                 name,
                 version,
-                manifest: AbsPathBuf::assert(manifest_path.into()).try_into().unwrap(),
+                manifest: AbsPathBuf::assert(manifest_path).try_into().unwrap(),
                 targets: Vec::new(),
                 is_local,
                 is_member,
@@ -370,7 +369,7 @@ impl CargoWorkspace {
                 let tgt = targets.alloc(TargetData {
                     package: pkg,
                     name,
-                    root: AbsPathBuf::assert(src_path.into()),
+                    root: AbsPathBuf::assert(src_path),
                     kind: TargetKind::new(&kind),
                     required_features,
                 });
@@ -393,11 +392,9 @@ impl CargoWorkspace {
             packages[source].active_features.extend(node.features);
         }
 
-        let workspace_root =
-            AbsPathBuf::assert(PathBuf::from(meta.workspace_root.into_os_string()));
+        let workspace_root = AbsPathBuf::assert(meta.workspace_root);
 
-        let target_directory =
-            AbsPathBuf::assert(PathBuf::from(meta.target_directory.into_os_string()));
+        let target_directory = AbsPathBuf::assert(meta.target_directory);
 
         CargoWorkspace { packages, targets, workspace_root, target_directory }
     }
diff --git a/crates/project-model/src/lib.rs b/crates/project-model/src/lib.rs
index 5b91f5d8058..51bb4fe303a 100644
--- a/crates/project-model/src/lib.rs
+++ b/crates/project-model/src/lib.rs
@@ -126,9 +126,8 @@ impl ProjectManifest {
             entities
                 .filter_map(Result::ok)
                 .map(|it| it.path().join("Cargo.toml"))
-                .filter(|it| it.exists())
-                .map(AbsPathBuf::assert)
-                .filter_map(|it| it.try_into().ok())
+                .map(AbsPathBuf::try_from)
+                .filter_map(|it| it.ok()?.try_into().ok())
                 .collect()
         }
     }
diff --git a/crates/project-model/src/project_json.rs b/crates/project-model/src/project_json.rs
index fba0aaa8ce9..0b6e8caf5dd 100644
--- a/crates/project-model/src/project_json.rs
+++ b/crates/project-model/src/project_json.rs
@@ -51,10 +51,9 @@
 
 use base_db::{CrateDisplayName, CrateId, CrateName, Dependency, Edition};
 use la_arena::RawIdx;
-use paths::{AbsPath, AbsPathBuf};
+use paths::{AbsPath, AbsPathBuf, Utf8PathBuf};
 use rustc_hash::FxHashMap;
 use serde::{de, Deserialize};
-use std::path::PathBuf;
 
 use crate::cfg_flag::CfgFlag;
 
@@ -113,7 +112,7 @@ impl ProjectJson {
                         .unwrap_or_else(|| root_module.starts_with(base));
                     let (include, exclude) = match crate_data.source {
                         Some(src) => {
-                            let absolutize = |dirs: Vec<PathBuf>| {
+                            let absolutize = |dirs: Vec<Utf8PathBuf>| {
                                 dirs.into_iter().map(absolutize_on_base).collect::<Vec<_>>()
                             };
                             (absolutize(src.include_dirs), absolutize(src.exclude_dirs))
@@ -176,15 +175,15 @@ impl ProjectJson {
 
 #[derive(Deserialize, Debug, Clone)]
 pub struct ProjectJsonData {
-    sysroot: Option<PathBuf>,
-    sysroot_src: Option<PathBuf>,
+    sysroot: Option<Utf8PathBuf>,
+    sysroot_src: Option<Utf8PathBuf>,
     crates: Vec<CrateData>,
 }
 
 #[derive(Deserialize, Debug, Clone)]
 struct CrateData {
     display_name: Option<String>,
-    root_module: PathBuf,
+    root_module: Utf8PathBuf,
     edition: EditionData,
     #[serde(default)]
     version: Option<semver::Version>,
@@ -194,7 +193,7 @@ struct CrateData {
     target: Option<String>,
     #[serde(default)]
     env: FxHashMap<String, String>,
-    proc_macro_dylib_path: Option<PathBuf>,
+    proc_macro_dylib_path: Option<Utf8PathBuf>,
     is_workspace_member: Option<bool>,
     source: Option<CrateSource>,
     #[serde(default)]
@@ -238,8 +237,8 @@ struct DepData {
 
 #[derive(Deserialize, Debug, Clone)]
 struct CrateSource {
-    include_dirs: Vec<PathBuf>,
-    exclude_dirs: Vec<PathBuf>,
+    include_dirs: Vec<Utf8PathBuf>,
+    exclude_dirs: Vec<Utf8PathBuf>,
 }
 
 fn deserialize_crate_name<'de, D>(de: D) -> std::result::Result<CrateName, D::Error>
diff --git a/crates/project-model/src/sysroot.rs b/crates/project-model/src/sysroot.rs
index 3127bae8b0c..1142d6243d2 100644
--- a/crates/project-model/src/sysroot.rs
+++ b/crates/project-model/src/sysroot.rs
@@ -4,13 +4,13 @@
 //! but we can't process `.rlib` and need source code instead. The source code
 //! is typically installed with `rustup component add rust-src` command.
 
-use std::{env, fs, iter, ops, path::PathBuf, process::Command, sync::Arc};
+use std::{env, fs, iter, ops, process::Command, sync::Arc};
 
 use anyhow::{format_err, Result};
 use base_db::CrateName;
 use itertools::Itertools;
 use la_arena::{Arena, Idx};
-use paths::{AbsPath, AbsPathBuf};
+use paths::{AbsPath, AbsPathBuf, Utf8PathBuf};
 use rustc_hash::FxHashMap;
 use toolchain::{probe_for_binary, Tool};
 
@@ -419,7 +419,7 @@ fn discover_sysroot_dir(
     rustc.current_dir(current_dir).args(["--print", "sysroot"]);
     tracing::debug!("Discovering sysroot by {:?}", rustc);
     let stdout = utf8_stdout(rustc)?;
-    Ok(AbsPathBuf::assert(PathBuf::from(stdout)))
+    Ok(AbsPathBuf::assert(Utf8PathBuf::from(stdout)))
 }
 
 fn discover_sysroot_src_dir(sysroot_path: &AbsPathBuf) -> Option<AbsPathBuf> {
diff --git a/crates/project-model/src/tests.rs b/crates/project-model/src/tests.rs
index b9b1b701f6d..fc0b507b332 100644
--- a/crates/project-model/src/tests.rs
+++ b/crates/project-model/src/tests.rs
@@ -1,12 +1,9 @@
-use std::{
-    ops::Deref,
-    path::{Path, PathBuf},
-};
+use std::ops::Deref;
 
 use base_db::{CrateGraph, FileId, ProcMacroPaths};
 use cfg::{CfgAtom, CfgDiff};
 use expect_test::{expect_file, ExpectFile};
-use paths::{AbsPath, AbsPathBuf};
+use paths::{AbsPath, AbsPathBuf, Utf8Path, Utf8PathBuf};
 use rustc_hash::FxHashMap;
 use serde::de::DeserializeOwned;
 use triomphe::Arc;
@@ -113,17 +110,16 @@ fn replace_root(s: &mut String, direction: bool) {
 fn replace_fake_sys_root(s: &mut String) {
     let fake_sysroot_path = get_test_path("fake-sysroot");
     let fake_sysroot_path = if cfg!(windows) {
-        let normalized_path =
-            fake_sysroot_path.to_str().expect("expected str").replace('\\', r#"\\"#);
+        let normalized_path = fake_sysroot_path.as_str().replace('\\', r#"\\"#);
         format!(r#"{}\\"#, normalized_path)
     } else {
-        format!("{}/", fake_sysroot_path.to_str().expect("expected str"))
+        format!("{}/", fake_sysroot_path.as_str())
     };
     *s = s.replace(&fake_sysroot_path, "$FAKESYSROOT$")
 }
 
-fn get_test_path(file: &str) -> PathBuf {
-    let base = PathBuf::from(env!("CARGO_MANIFEST_DIR"));
+fn get_test_path(file: &str) -> Utf8PathBuf {
+    let base = Utf8PathBuf::from(env!("CARGO_MANIFEST_DIR"));
     base.join("test_data").join(file)
 }
 
@@ -139,7 +135,7 @@ fn get_fake_sysroot() -> Sysroot {
 fn rooted_project_json(data: ProjectJsonData) -> ProjectJson {
     let mut root = "$ROOT$".to_owned();
     replace_root(&mut root, true);
-    let path = Path::new(&root);
+    let path = Utf8Path::new(&root);
     let base = AbsPath::assert(path);
     ProjectJson::new(base, data)
 }
@@ -268,7 +264,7 @@ fn smoke_test_real_sysroot_cargo() {
 
     let cargo_workspace = CargoWorkspace::new(meta);
     let sysroot = Ok(Sysroot::discover(
-        AbsPath::assert(Path::new(env!("CARGO_MANIFEST_DIR"))),
+        AbsPath::assert(Utf8Path::new(env!("CARGO_MANIFEST_DIR"))),
         &Default::default(),
         true,
     )
diff --git a/crates/project-model/src/workspace.rs b/crates/project-model/src/workspace.rs
index 8b4d6d99414..c6642efca24 100644
--- a/crates/project-model/src/workspace.rs
+++ b/crates/project-model/src/workspace.rs
@@ -1173,7 +1173,6 @@ fn detached_files_to_crate_graph(
         };
         let display_name = detached_file
             .file_stem()
-            .and_then(|os_str| os_str.to_str())
             .map(|file_stem| CrateDisplayName::from_canonical_name(file_stem.to_owned()));
         let detached_file_crate = crate_graph.add_crate_root(
             file_id,
@@ -1555,7 +1554,7 @@ fn inject_cargo_env(package: &PackageData, env: &mut Env) {
     // CARGO_BIN_NAME, CARGO_BIN_EXE_<name>
 
     let manifest_dir = package.manifest.parent();
-    env.set("CARGO_MANIFEST_DIR", manifest_dir.as_os_str().to_string_lossy().into_owned());
+    env.set("CARGO_MANIFEST_DIR", manifest_dir.as_str().to_owned());
 
     // Not always right, but works for common cases.
     env.set("CARGO", "cargo".into());
diff --git a/crates/rust-analyzer/Cargo.toml b/crates/rust-analyzer/Cargo.toml
index e6984d6f41b..6d70124188d 100644
--- a/crates/rust-analyzer/Cargo.toml
+++ b/crates/rust-analyzer/Cargo.toml
@@ -43,6 +43,7 @@ nohash-hasher.workspace = true
 always-assert = "0.2.0"
 walkdir = "2.3.2"
 semver.workspace = true
+memchr = "2.7.1"
 
 cfg.workspace = true
 flycheck.workspace = true
@@ -63,7 +64,7 @@ parser.workspace = true
 toolchain.workspace = true
 vfs-notify.workspace = true
 vfs.workspace = true
-memchr = "2.7.1"
+paths.workspace = true
 
 [target.'cfg(windows)'.dependencies]
 winapi = "0.3.9"
diff --git a/crates/rust-analyzer/src/bin/main.rs b/crates/rust-analyzer/src/bin/main.rs
index e747ec87b1c..78920f3abac 100644
--- a/crates/rust-analyzer/src/bin/main.rs
+++ b/crates/rust-analyzer/src/bin/main.rs
@@ -190,7 +190,7 @@ fn run_server() -> anyhow::Result<()> {
         Some(it) => it,
         None => {
             let cwd = env::current_dir()?;
-            AbsPathBuf::assert(cwd)
+            AbsPathBuf::assert_utf8(cwd)
         }
     };
 
diff --git a/crates/rust-analyzer/src/cli/analysis_stats.rs b/crates/rust-analyzer/src/cli/analysis_stats.rs
index 5c474908e7a..c636f7494a4 100644
--- a/crates/rust-analyzer/src/cli/analysis_stats.rs
+++ b/crates/rust-analyzer/src/cli/analysis_stats.rs
@@ -70,7 +70,7 @@ impl flags::AnalysisStats {
 
         let mut db_load_sw = self.stop_watch();
 
-        let path = AbsPathBuf::assert(env::current_dir()?.join(&self.path));
+        let path = AbsPathBuf::assert_utf8(env::current_dir()?.join(&self.path));
         let manifest = ProjectManifest::discover_single(&path)?;
 
         let mut workspace = ProjectWorkspace::load(manifest, &cargo_config, no_progress)?;
diff --git a/crates/rust-analyzer/src/cli/diagnostics.rs b/crates/rust-analyzer/src/cli/diagnostics.rs
index bd2646126dc..79d6226debf 100644
--- a/crates/rust-analyzer/src/cli/diagnostics.rs
+++ b/crates/rust-analyzer/src/cli/diagnostics.rs
@@ -16,7 +16,7 @@ impl flags::Diagnostics {
         let cargo_config =
             CargoConfig { sysroot: Some(RustLibSource::Discover), ..Default::default() };
         let with_proc_macro_server = if let Some(p) = &self.proc_macro_srv {
-            let path = vfs::AbsPathBuf::assert(std::env::current_dir()?.join(p));
+            let path = vfs::AbsPathBuf::assert_utf8(std::env::current_dir()?.join(p));
             ProcMacroServerChoice::Explicit(path)
         } else {
             ProcMacroServerChoice::Sysroot
diff --git a/crates/rust-analyzer/src/cli/lsif.rs b/crates/rust-analyzer/src/cli/lsif.rs
index f3f5ec1ebde..3ff9be7102f 100644
--- a/crates/rust-analyzer/src/cli/lsif.rs
+++ b/crates/rust-analyzer/src/cli/lsif.rs
@@ -283,7 +283,7 @@ impl flags::Lsif {
             with_proc_macro_server: ProcMacroServerChoice::Sysroot,
             prefill_caches: false,
         };
-        let path = AbsPathBuf::assert(env::current_dir()?.join(self.path));
+        let path = AbsPathBuf::assert_utf8(env::current_dir()?.join(self.path));
         let manifest = ProjectManifest::discover_single(&path)?;
 
         let workspace = ProjectWorkspace::load(manifest, &cargo_config, no_progress)?;
diff --git a/crates/rust-analyzer/src/cli/scip.rs b/crates/rust-analyzer/src/cli/scip.rs
index 1061a433a58..aef2c1be224 100644
--- a/crates/rust-analyzer/src/cli/scip.rs
+++ b/crates/rust-analyzer/src/cli/scip.rs
@@ -27,7 +27,8 @@ impl flags::Scip {
             with_proc_macro_server: ProcMacroServerChoice::Sysroot,
             prefill_caches: true,
         };
-        let root = vfs::AbsPathBuf::assert(std::env::current_dir()?.join(&self.path)).normalize();
+        let root =
+            vfs::AbsPathBuf::assert_utf8(std::env::current_dir()?.join(&self.path)).normalize();
 
         let mut config = crate::config::Config::new(
             root.clone(),
@@ -63,12 +64,7 @@ impl flags::Scip {
                 special_fields: Default::default(),
             })
             .into(),
-            project_root: format!(
-                "file://{}",
-                root.as_os_str()
-                    .to_str()
-                    .ok_or(anyhow::format_err!("Unable to normalize project_root path"))?
-            ),
+            project_root: format!("file://{root}"),
             text_document_encoding: scip_types::TextEncoding::UTF8.into(),
             special_fields: Default::default(),
         };
@@ -216,7 +212,7 @@ fn get_relative_filepath(
     rootpath: &vfs::AbsPathBuf,
     file_id: ide::FileId,
 ) -> Option<String> {
-    Some(vfs.file_path(file_id).as_path()?.strip_prefix(rootpath)?.as_ref().to_str()?.to_owned())
+    Some(vfs.file_path(file_id).as_path()?.strip_prefix(rootpath)?.as_str().to_owned())
 }
 
 // SCIP Ranges have a (very large) optimization that ranges if they are on the same line
diff --git a/crates/rust-analyzer/src/config.rs b/crates/rust-analyzer/src/config.rs
index cbf15246590..e6b60f69065 100644
--- a/crates/rust-analyzer/src/config.rs
+++ b/crates/rust-analyzer/src/config.rs
@@ -7,11 +7,7 @@
 //! configure the server itself, feature flags are passed into analysis, and
 //! tweak things like automatic insertion of `()` in completions.
 
-use std::{
-    fmt, iter,
-    ops::Not,
-    path::{Path, PathBuf},
-};
+use std::{fmt, iter, ops::Not};
 
 use cfg::{CfgAtom, CfgDiff};
 use flycheck::FlycheckConfig;
@@ -27,6 +23,7 @@ use ide_db::{
 };
 use itertools::Itertools;
 use lsp_types::{ClientCapabilities, MarkupKind};
+use paths::{Utf8Path, Utf8PathBuf};
 use project_model::{
     CargoConfig, CargoFeatures, ProjectJson, ProjectJsonData, ProjectManifest, RustLibSource,
 };
@@ -327,7 +324,7 @@ config_data! {
         /// These directories will be ignored by rust-analyzer. They are
         /// relative to the workspace root, and globs are not supported. You may
         /// also need to add the folders to Code's `files.watcherExclude`.
-        files_excludeDirs: Vec<PathBuf> = "[]",
+        files_excludeDirs: Vec<Utf8PathBuf> = "[]",
         /// Controls file watching implementation.
         files_watcher: FilesWatcherDef = "\"client\"",
 
@@ -516,7 +513,7 @@ config_data! {
         /// This config takes a map of crate names with the exported proc-macro names to ignore as values.
         procMacro_ignored: FxHashMap<Box<str>, Box<[Box<str>]>>          = "{}",
         /// Internal config, path to proc-macro server executable.
-        procMacro_server: Option<PathBuf>          = "null",
+        procMacro_server: Option<Utf8PathBuf>          = "null",
 
         /// Exclude imports from find-all-references.
         references_excludeImports: bool = "false",
@@ -864,7 +861,7 @@ impl Config {
         }
         let mut errors = Vec::new();
         self.detached_files =
-            get_field::<Vec<PathBuf>>(&mut json, &mut errors, "detachedFiles", None, "[]")
+            get_field::<Vec<Utf8PathBuf>>(&mut json, &mut errors, "detachedFiles", None, "[]")
                 .into_iter()
                 .map(AbsPathBuf::assert)
                 .collect();
@@ -956,7 +953,7 @@ impl Config {
     pub fn has_linked_projects(&self) -> bool {
         !self.data.linkedProjects.is_empty()
     }
-    pub fn linked_manifests(&self) -> impl Iterator<Item = &Path> + '_ {
+    pub fn linked_manifests(&self) -> impl Iterator<Item = &Utf8Path> + '_ {
         self.data.linkedProjects.iter().filter_map(|it| match it {
             ManifestOrProjectJson::Manifest(p) => Some(&**p),
             ManifestOrProjectJson::ProjectJson(_) => None,
@@ -1410,9 +1407,11 @@ impl Config {
         }
     }
 
-    fn target_dir_from_config(&self) -> Option<PathBuf> {
+    fn target_dir_from_config(&self) -> Option<Utf8PathBuf> {
         self.data.cargo_targetDir.as_ref().and_then(|target_dir| match target_dir {
-            TargetDirectory::UseSubdirectory(true) => Some(PathBuf::from("target/rust-analyzer")),
+            TargetDirectory::UseSubdirectory(true) => {
+                Some(Utf8PathBuf::from("target/rust-analyzer"))
+            }
             TargetDirectory::UseSubdirectory(false) => None,
             TargetDirectory::Directory(dir) if dir.is_relative() => Some(dir.clone()),
             TargetDirectory::Directory(_) => None,
@@ -1951,7 +1950,7 @@ where
 #[derive(Deserialize, Debug, Clone)]
 #[serde(untagged)]
 enum ManifestOrProjectJson {
-    Manifest(PathBuf),
+    Manifest(Utf8PathBuf),
     ProjectJson(ProjectJsonData),
 }
 
@@ -2134,7 +2133,7 @@ pub enum MemoryLayoutHoverRenderKindDef {
 #[serde(untagged)]
 pub enum TargetDirectory {
     UseSubdirectory(bool),
-    Directory(PathBuf),
+    Directory(Utf8PathBuf),
 }
 
 macro_rules! _config_data {
@@ -2263,7 +2262,7 @@ fn field_props(field: &str, ty: &str, doc: &[&str], default: &str) -> serde_json
             "type": "array",
             "items": { "type": "string" },
         },
-        "Vec<PathBuf>" => set! {
+        "Vec<Utf8PathBuf>" => set! {
             "type": "array",
             "items": { "type": "string" },
         },
@@ -2291,7 +2290,7 @@ fn field_props(field: &str, ty: &str, doc: &[&str], default: &str) -> serde_json
         "Option<String>" => set! {
             "type": ["null", "string"],
         },
-        "Option<PathBuf>" => set! {
+        "Option<Utf8PathBuf>" => set! {
             "type": ["null", "string"],
         },
         "Option<bool>" => set! {
@@ -2774,7 +2773,7 @@ mod tests {
             .unwrap();
         assert_eq!(config.data.cargo_targetDir, Some(TargetDirectory::UseSubdirectory(true)));
         assert!(
-            matches!(config.flycheck(), FlycheckConfig::CargoCommand { target_dir, .. } if target_dir == Some(PathBuf::from("target/rust-analyzer")))
+            matches!(config.flycheck(), FlycheckConfig::CargoCommand { target_dir, .. } if target_dir == Some(Utf8PathBuf::from("target/rust-analyzer")))
         );
     }
 
@@ -2793,10 +2792,10 @@ mod tests {
             .unwrap();
         assert_eq!(
             config.data.cargo_targetDir,
-            Some(TargetDirectory::Directory(PathBuf::from("other_folder")))
+            Some(TargetDirectory::Directory(Utf8PathBuf::from("other_folder")))
         );
         assert!(
-            matches!(config.flycheck(), FlycheckConfig::CargoCommand { target_dir, .. } if target_dir == Some(PathBuf::from("other_folder")))
+            matches!(config.flycheck(), FlycheckConfig::CargoCommand { target_dir, .. } if target_dir == Some(Utf8PathBuf::from("other_folder")))
         );
     }
 }
diff --git a/crates/rust-analyzer/src/diagnostics/to_proto.rs b/crates/rust-analyzer/src/diagnostics/to_proto.rs
index 6e6cc53c251..7c4deac93f2 100644
--- a/crates/rust-analyzer/src/diagnostics/to_proto.rs
+++ b/crates/rust-analyzer/src/diagnostics/to_proto.rs
@@ -519,14 +519,13 @@ fn clippy_code_description(code: Option<&str>) -> Option<lsp_types::CodeDescript
 #[cfg(test)]
 #[cfg(not(windows))]
 mod tests {
-    use std::path::Path;
-
     use crate::{config::Config, global_state::GlobalState};
 
     use super::*;
 
     use expect_test::{expect_file, ExpectFile};
     use lsp_types::ClientCapabilities;
+    use paths::Utf8Path;
 
     fn check(diagnostics_json: &str, expect: ExpectFile) {
         check_with_config(DiagnosticsMapConfig::default(), diagnostics_json, expect)
@@ -534,7 +533,7 @@ mod tests {
 
     fn check_with_config(config: DiagnosticsMapConfig, diagnostics_json: &str, expect: ExpectFile) {
         let diagnostic: flycheck::Diagnostic = serde_json::from_str(diagnostics_json).unwrap();
-        let workspace_root: &AbsPath = Path::new("/test/").try_into().unwrap();
+        let workspace_root: &AbsPath = Utf8Path::new("/test/").try_into().unwrap();
         let (sender, _) = crossbeam_channel::unbounded();
         let state = GlobalState::new(
             sender,
diff --git a/crates/rust-analyzer/src/handlers/request.rs b/crates/rust-analyzer/src/handlers/request.rs
index ab7f9443281..4d4103a7ad7 100644
--- a/crates/rust-analyzer/src/handlers/request.rs
+++ b/crates/rust-analyzer/src/handlers/request.rs
@@ -4,7 +4,6 @@
 use std::{
     fs,
     io::Write as _,
-    path::PathBuf,
     process::{self, Stdio},
 };
 
@@ -27,6 +26,7 @@ use lsp_types::{
     SemanticTokensParams, SemanticTokensRangeParams, SemanticTokensRangeResult,
     SemanticTokensResult, SymbolInformation, SymbolTag, TextDocumentIdentifier, Url, WorkspaceEdit,
 };
+use paths::Utf8PathBuf;
 use project_model::{ManifestPath, ProjectWorkspace, TargetKind};
 use serde_json::json;
 use stdx::{format_to, never};
@@ -1737,8 +1737,8 @@ pub(crate) fn handle_open_docs(
         _ => (None, None),
     };
 
-    let sysroot = sysroot.map(|p| p.root().as_os_str());
-    let target_dir = cargo.map(|cargo| cargo.target_directory()).map(|p| p.as_os_str());
+    let sysroot = sysroot.map(|p| p.root().as_str());
+    let target_dir = cargo.map(|cargo| cargo.target_directory()).map(|p| p.as_str());
 
     let Ok(remote_urls) = snap.analysis.external_docs(position, target_dir, sysroot) else {
         return if snap.config.local_docs() {
@@ -2043,7 +2043,7 @@ fn run_rustfmt(
             cmd
         }
         RustfmtConfig::CustomCommand { command, args } => {
-            let cmd = PathBuf::from(&command);
+            let cmd = Utf8PathBuf::from(&command);
             let workspace = CargoTargetSpec::for_file(snap, file_id)?;
             let mut cmd = match workspace {
                 Some(spec) => {
diff --git a/crates/rust-analyzer/src/integrated_benchmarks.rs b/crates/rust-analyzer/src/integrated_benchmarks.rs
index 1c5a862c703..2731e845f35 100644
--- a/crates/rust-analyzer/src/integrated_benchmarks.rs
+++ b/crates/rust-analyzer/src/integrated_benchmarks.rs
@@ -52,7 +52,7 @@ fn integrated_highlighting_benchmark() {
 
     let file_id = {
         let file = workspace_to_load.join(file);
-        let path = VfsPath::from(AbsPathBuf::assert(file));
+        let path = VfsPath::from(AbsPathBuf::assert_utf8(file));
         vfs.file_id(&path).unwrap_or_else(|| panic!("can't find virtual file for {path}"))
     };
 
@@ -112,7 +112,7 @@ fn integrated_completion_benchmark() {
 
     let file_id = {
         let file = workspace_to_load.join(file);
-        let path = VfsPath::from(AbsPathBuf::assert(file));
+        let path = VfsPath::from(AbsPathBuf::assert_utf8(file));
         vfs.file_id(&path).unwrap_or_else(|| panic!("can't find virtual file for {path}"))
     };
 
@@ -274,7 +274,7 @@ fn integrated_diagnostics_benchmark() {
 
     let file_id = {
         let file = workspace_to_load.join(file);
-        let path = VfsPath::from(AbsPathBuf::assert(file));
+        let path = VfsPath::from(AbsPathBuf::assert_utf8(file));
         vfs.file_id(&path).unwrap_or_else(|| panic!("can't find virtual file for {path}"))
     };
 
diff --git a/crates/rust-analyzer/src/lsp/to_proto.rs b/crates/rust-analyzer/src/lsp/to_proto.rs
index 44f0b1c80f1..d8bb12528b9 100644
--- a/crates/rust-analyzer/src/lsp/to_proto.rs
+++ b/crates/rust-analyzer/src/lsp/to_proto.rs
@@ -1,7 +1,7 @@
 //! Conversion of rust-analyzer specific types to lsp_types equivalents.
 use std::{
     iter::once,
-    mem, path,
+    mem,
     sync::atomic::{AtomicU32, Ordering},
 };
 
@@ -15,6 +15,7 @@ use ide::{
 };
 use ide_db::{rust_doc::format_docs, FxHasher};
 use itertools::Itertools;
+use paths::{Utf8Component, Utf8Prefix};
 use semver::VersionReq;
 use serde_json::to_value;
 use vfs::AbsPath;
@@ -816,9 +817,9 @@ pub(crate) fn url(snap: &GlobalStateSnapshot, file_id: FileId) -> lsp_types::Url
 /// When processing non-windows path, this is essentially the same as `Url::from_file_path`.
 pub(crate) fn url_from_abs_path(path: &AbsPath) -> lsp_types::Url {
     let url = lsp_types::Url::from_file_path(path).unwrap();
-    match path.as_ref().components().next() {
-        Some(path::Component::Prefix(prefix))
-            if matches!(prefix.kind(), path::Prefix::Disk(_) | path::Prefix::VerbatimDisk(_)) =>
+    match path.components().next() {
+        Some(Utf8Component::Prefix(prefix))
+            if matches!(prefix.kind(), Utf8Prefix::Disk(_) | Utf8Prefix::VerbatimDisk(_)) =>
         {
             // Need to lowercase driver letter
         }
@@ -2730,12 +2731,12 @@ struct ProcMacro {
     #[test]
     #[cfg(target_os = "windows")]
     fn test_lowercase_drive_letter() {
-        use std::path::Path;
+        use paths::Utf8Path;
 
-        let url = url_from_abs_path(Path::new("C:\\Test").try_into().unwrap());
+        let url = url_from_abs_path(Utf8Path::new("C:\\Test").try_into().unwrap());
         assert_eq!(url.to_string(), "file:///c:/Test");
 
-        let url = url_from_abs_path(Path::new(r#"\\localhost\C$\my_dir"#).try_into().unwrap());
+        let url = url_from_abs_path(Utf8Path::new(r#"\\localhost\C$\my_dir"#).try_into().unwrap());
         assert_eq!(url.to_string(), "file://localhost/C$/my_dir");
     }
 }
diff --git a/crates/rust-analyzer/src/main_loop.rs b/crates/rust-analyzer/src/main_loop.rs
index 945d169a69c..666bf2920e4 100644
--- a/crates/rust-analyzer/src/main_loop.rs
+++ b/crates/rust-analyzer/src/main_loop.rs
@@ -714,10 +714,9 @@ impl GlobalState {
                     message += &format!(
                         ": {}",
                         match dir.strip_prefix(self.config.root_path()) {
-                            Some(relative_path) => relative_path.as_ref(),
+                            Some(relative_path) => relative_path.as_utf8_path(),
                             None => dir.as_ref(),
                         }
-                        .display()
                     );
                 }
 
diff --git a/crates/rust-analyzer/src/reload.rs b/crates/rust-analyzer/src/reload.rs
index ff7958feae7..5dc152142e4 100644
--- a/crates/rust-analyzer/src/reload.rs
+++ b/crates/rust-analyzer/src/reload.rs
@@ -185,10 +185,8 @@ impl GlobalState {
                 message.push_str(
                     "`rust-analyzer.linkedProjects` have been specified, which may be incorrect. Specified project paths:\n",
                 );
-                message.push_str(&format!(
-                    "    {}",
-                    self.config.linked_manifests().map(|it| it.display()).format("\n    ")
-                ));
+                message
+                    .push_str(&format!("    {}", self.config.linked_manifests().format("\n    ")));
                 if self.config.has_linked_project_jsons() {
                     message.push_str("\nAdditionally, one or more project jsons are specified")
                 }
@@ -753,7 +751,7 @@ pub(crate) fn should_refresh_for_change(path: &AbsPath, change_kind: ChangeKind)
     const IMPLICIT_TARGET_FILES: &[&str] = &["build.rs", "src/main.rs", "src/lib.rs"];
     const IMPLICIT_TARGET_DIRS: &[&str] = &["src/bin", "examples", "tests", "benches"];
 
-    let file_name = match path.file_name().unwrap_or_default().to_str() {
+    let file_name = match path.file_name() {
         Some(it) => it,
         None => return false,
     };
@@ -768,18 +766,18 @@ pub(crate) fn should_refresh_for_change(path: &AbsPath, change_kind: ChangeKind)
     // .cargo/config{.toml}
     if path.extension().unwrap_or_default() != "rs" {
         let is_cargo_config = matches!(file_name, "config.toml" | "config")
-            && path.parent().map(|parent| parent.as_ref().ends_with(".cargo")).unwrap_or(false);
+            && path.parent().map(|parent| parent.as_str().ends_with(".cargo")).unwrap_or(false);
         return is_cargo_config;
     }
 
-    if IMPLICIT_TARGET_FILES.iter().any(|it| path.as_ref().ends_with(it)) {
+    if IMPLICIT_TARGET_FILES.iter().any(|it| path.as_str().ends_with(it)) {
         return true;
     }
     let parent = match path.parent() {
         Some(it) => it,
         None => return false,
     };
-    if IMPLICIT_TARGET_DIRS.iter().any(|it| parent.as_ref().ends_with(it)) {
+    if IMPLICIT_TARGET_DIRS.iter().any(|it| parent.as_str().ends_with(it)) {
         return true;
     }
     if file_name == "main.rs" {
@@ -787,7 +785,7 @@ pub(crate) fn should_refresh_for_change(path: &AbsPath, change_kind: ChangeKind)
             Some(it) => it,
             None => return false,
         };
-        if IMPLICIT_TARGET_DIRS.iter().any(|it| grand_parent.as_ref().ends_with(it)) {
+        if IMPLICIT_TARGET_DIRS.iter().any(|it| grand_parent.as_str().ends_with(it)) {
             return true;
         }
     }
diff --git a/crates/rust-analyzer/tests/crate_graph.rs b/crates/rust-analyzer/tests/crate_graph.rs
index efd42fadf7e..cf38032b941 100644
--- a/crates/rust-analyzer/tests/crate_graph.rs
+++ b/crates/rust-analyzer/tests/crate_graph.rs
@@ -60,7 +60,7 @@ fn get_fake_sysroot() -> Sysroot {
     let sysroot_path = get_fake_sysroot_path();
     // there's no `libexec/` directory with a `proc-macro-srv` binary in that
     // fake sysroot, so we give them both the same path:
-    let sysroot_dir = AbsPathBuf::assert(sysroot_path);
+    let sysroot_dir = AbsPathBuf::assert_utf8(sysroot_path);
     let sysroot_src_dir = sysroot_dir.clone();
     Sysroot::load(sysroot_dir, Some(Ok(sysroot_src_dir)), false)
 }
diff --git a/crates/rust-analyzer/tests/slow-tests/main.rs b/crates/rust-analyzer/tests/slow-tests/main.rs
index 960f5b531d4..cb43619262d 100644
--- a/crates/rust-analyzer/tests/slow-tests/main.rs
+++ b/crates/rust-analyzer/tests/slow-tests/main.rs
@@ -917,7 +917,7 @@ fn resolve_proc_macro() {
     }
 
     let sysroot = project_model::Sysroot::discover_no_source(
-        &AbsPathBuf::assert(std::env::current_dir().unwrap()),
+        &AbsPathBuf::assert_utf8(std::env::current_dir().unwrap()),
         &Default::default(),
     )
     .unwrap();
@@ -1002,7 +1002,7 @@ pub fn foo(_input: TokenStream) -> TokenStream {
         },
         "procMacro": {
             "enable": true,
-            "server": proc_macro_server_path.as_path().as_ref(),
+            "server": proc_macro_server_path.as_path().as_str(),
         }
     }))
     .root("foo")
@@ -1039,7 +1039,7 @@ fn test_will_rename_files_same_level() {
 
     let tmp_dir = TestDir::new();
     let tmp_dir_path = tmp_dir.path().to_owned();
-    let tmp_dir_str = tmp_dir_path.to_str().unwrap();
+    let tmp_dir_str = tmp_dir_path.as_str();
     let base_path = PathBuf::from(format!("file://{tmp_dir_str}"));
 
     let code = r#"
@@ -1084,7 +1084,7 @@ use crate::old_folder::nested::foo as bar;
           "documentChanges": [
             {
               "textDocument": {
-                "uri": format!("file://{}", tmp_dir_path.join("src").join("lib.rs").to_str().unwrap().to_owned().replace("C:\\", "/c:/").replace('\\', "/")),
+                "uri": format!("file://{}", tmp_dir_path.join("src").join("lib.rs").as_str().to_owned().replace("C:\\", "/c:/").replace('\\', "/")),
                 "version": null
               },
               "edits": [
@@ -1141,7 +1141,7 @@ use crate::old_folder::nested::foo as bar;
           "documentChanges": [
             {
               "textDocument": {
-                "uri": format!("file://{}", tmp_dir_path.join("src").join("lib.rs").to_str().unwrap().to_owned().replace("C:\\", "/c:/").replace('\\', "/")),
+                "uri": format!("file://{}", tmp_dir_path.join("src").join("lib.rs").as_str().to_owned().replace("C:\\", "/c:/").replace('\\', "/")),
                 "version": null
               },
               "edits": [
@@ -1162,7 +1162,7 @@ use crate::old_folder::nested::foo as bar;
             },
             {
               "textDocument": {
-                "uri": format!("file://{}", tmp_dir_path.join("src").join("old_folder").join("nested.rs").to_str().unwrap().to_owned().replace("C:\\", "/c:/").replace('\\', "/")),
+                "uri": format!("file://{}", tmp_dir_path.join("src").join("old_folder").join("nested.rs").as_str().to_owned().replace("C:\\", "/c:/").replace('\\', "/")),
                 "version": null
               },
               "edits": [
diff --git a/crates/rust-analyzer/tests/slow-tests/support.rs b/crates/rust-analyzer/tests/slow-tests/support.rs
index 1d831b8b105..8bbe6ff3724 100644
--- a/crates/rust-analyzer/tests/slow-tests/support.rs
+++ b/crates/rust-analyzer/tests/slow-tests/support.rs
@@ -1,7 +1,6 @@
 use std::{
     cell::{Cell, RefCell},
     fs,
-    path::{Path, PathBuf},
     sync::Once,
     time::Duration,
 };
@@ -9,6 +8,7 @@ use std::{
 use crossbeam_channel::{after, select, Receiver};
 use lsp_server::{Connection, Message, Notification, Request};
 use lsp_types::{notification::Exit, request::Shutdown, TextDocumentIdentifier, Url};
+use paths::{Utf8Path, Utf8PathBuf};
 use rust_analyzer::{config::Config, lsp, main_loop};
 use serde::Serialize;
 use serde_json::{json, to_string_pretty, Value};
@@ -21,7 +21,7 @@ use crate::testdir::TestDir;
 pub(crate) struct Project<'a> {
     fixture: &'a str,
     tmp_dir: Option<TestDir>,
-    roots: Vec<PathBuf>,
+    roots: Vec<Utf8PathBuf>,
     config: serde_json::Value,
     root_dir_contains_symlink: bool,
 }
@@ -359,7 +359,7 @@ impl Server {
         self.client.sender.send(Message::Notification(not)).unwrap();
     }
 
-    pub(crate) fn path(&self) -> &Path {
+    pub(crate) fn path(&self) -> &Utf8Path {
         self.dir.path()
     }
 }
diff --git a/crates/rust-analyzer/tests/slow-tests/testdir.rs b/crates/rust-analyzer/tests/slow-tests/testdir.rs
index b3ee7fa3d03..d113bd51278 100644
--- a/crates/rust-analyzer/tests/slow-tests/testdir.rs
+++ b/crates/rust-analyzer/tests/slow-tests/testdir.rs
@@ -1,11 +1,12 @@
 use std::{
     fs, io,
-    path::{Path, PathBuf},
     sync::atomic::{AtomicUsize, Ordering},
 };
 
+use paths::{Utf8Path, Utf8PathBuf};
+
 pub(crate) struct TestDir {
-    path: PathBuf,
+    path: Utf8PathBuf,
     keep: bool,
 }
 
@@ -51,10 +52,13 @@ impl TestDir {
                 #[cfg(target_os = "windows")]
                 std::os::windows::fs::symlink_dir(path, &symlink_path).unwrap();
 
-                return TestDir { path: symlink_path, keep: false };
+                return TestDir {
+                    path: Utf8PathBuf::from_path_buf(symlink_path).unwrap(),
+                    keep: false,
+                };
             }
 
-            return TestDir { path, keep: false };
+            return TestDir { path: Utf8PathBuf::from_path_buf(path).unwrap(), keep: false };
         }
         panic!("Failed to create a temporary directory")
     }
@@ -64,7 +68,7 @@ impl TestDir {
         self.keep = true;
         self
     }
-    pub(crate) fn path(&self) -> &Path {
+    pub(crate) fn path(&self) -> &Utf8Path {
         &self.path
     }
 }
@@ -79,7 +83,7 @@ impl Drop for TestDir {
         let actual_path = filetype.is_symlink().then(|| fs::read_link(&self.path).unwrap());
 
         if let Some(actual_path) = actual_path {
-            remove_dir_all(&actual_path).unwrap_or_else(|err| {
+            remove_dir_all(Utf8Path::from_path(&actual_path).unwrap()).unwrap_or_else(|err| {
                 panic!(
                     "failed to remove temporary link to directory {}: {err}",
                     actual_path.display()
@@ -88,18 +92,18 @@ impl Drop for TestDir {
         }
 
         remove_dir_all(&self.path).unwrap_or_else(|err| {
-            panic!("failed to remove temporary directory {}: {err}", self.path.display())
+            panic!("failed to remove temporary directory {}: {err}", self.path)
         });
     }
 }
 
 #[cfg(not(windows))]
-fn remove_dir_all(path: &Path) -> io::Result<()> {
+fn remove_dir_all(path: &Utf8Path) -> io::Result<()> {
     fs::remove_dir_all(path)
 }
 
 #[cfg(windows)]
-fn remove_dir_all(path: &Path) -> io::Result<()> {
+fn remove_dir_all(path: &Utf8Path) -> io::Result<()> {
     for _ in 0..99 {
         if fs::remove_dir_all(path).is_ok() {
             return Ok(());
diff --git a/crates/toolchain/Cargo.toml b/crates/toolchain/Cargo.toml
index f9b120772f0..c85efd432b0 100644
--- a/crates/toolchain/Cargo.toml
+++ b/crates/toolchain/Cargo.toml
@@ -13,6 +13,7 @@ doctest = false
 
 [dependencies]
 home = "0.5.4"
+camino.workspace = true
 
 [lints]
-workspace = true
\ No newline at end of file
+workspace = true
diff --git a/crates/toolchain/src/lib.rs b/crates/toolchain/src/lib.rs
index a77fed585af..b577723612d 100644
--- a/crates/toolchain/src/lib.rs
+++ b/crates/toolchain/src/lib.rs
@@ -2,10 +2,9 @@
 
 #![warn(rust_2018_idioms, unused_lifetimes)]
 
-use std::{
-    env, iter,
-    path::{Path, PathBuf},
-};
+use std::{env, iter, path::PathBuf};
+
+use camino::{Utf8Path, Utf8PathBuf};
 
 #[derive(Copy, Clone)]
 pub enum Tool {
@@ -16,7 +15,7 @@ pub enum Tool {
 }
 
 impl Tool {
-    pub fn proxy(self) -> Option<PathBuf> {
+    pub fn proxy(self) -> Option<Utf8PathBuf> {
         cargo_proxy(self.name())
     }
 
@@ -33,7 +32,7 @@ impl Tool {
     ///      example: for cargo, this tries all paths in $PATH with appended `cargo`, returning the
     ///      first that exists
     /// 4) If all else fails, we just try to use the executable name directly
-    pub fn prefer_proxy(self) -> PathBuf {
+    pub fn prefer_proxy(self) -> Utf8PathBuf {
         invoke(&[cargo_proxy, lookup_as_env_var, lookup_in_path], self.name())
     }
 
@@ -50,11 +49,11 @@ impl Tool {
     ///      example: for cargo, this tries $CARGO_HOME/bin/cargo, or ~/.cargo/bin/cargo if $CARGO_HOME is unset.
     ///      It seems that this is a reasonable place to try for cargo, rustc, and rustup
     /// 4) If all else fails, we just try to use the executable name directly
-    pub fn path(self) -> PathBuf {
+    pub fn path(self) -> Utf8PathBuf {
         invoke(&[lookup_as_env_var, lookup_in_path, cargo_proxy], self.name())
     }
 
-    pub fn path_in(self, path: &Path) -> Option<PathBuf> {
+    pub fn path_in(self, path: &Utf8Path) -> Option<Utf8PathBuf> {
         probe_for_binary(path.join(self.name()))
     }
 
@@ -68,42 +67,50 @@ impl Tool {
     }
 }
 
-fn invoke(list: &[fn(&str) -> Option<PathBuf>], executable: &str) -> PathBuf {
+fn invoke(list: &[fn(&str) -> Option<Utf8PathBuf>], executable: &str) -> Utf8PathBuf {
     list.iter().find_map(|it| it(executable)).unwrap_or_else(|| executable.into())
 }
 
 /// Looks up the binary as its SCREAMING upper case in the env variables.
-fn lookup_as_env_var(executable_name: &str) -> Option<PathBuf> {
-    env::var_os(executable_name.to_ascii_uppercase()).map(Into::into)
+fn lookup_as_env_var(executable_name: &str) -> Option<Utf8PathBuf> {
+    env::var_os(executable_name.to_ascii_uppercase())
+        .map(PathBuf::from)
+        .map(Utf8PathBuf::try_from)
+        .and_then(Result::ok)
 }
 
 /// Looks up the binary in the cargo home directory if it exists.
-fn cargo_proxy(executable_name: &str) -> Option<PathBuf> {
+fn cargo_proxy(executable_name: &str) -> Option<Utf8PathBuf> {
     let mut path = get_cargo_home()?;
     path.push("bin");
     path.push(executable_name);
     probe_for_binary(path)
 }
 
-fn get_cargo_home() -> Option<PathBuf> {
+fn get_cargo_home() -> Option<Utf8PathBuf> {
     if let Some(path) = env::var_os("CARGO_HOME") {
-        return Some(path.into());
+        return Utf8PathBuf::try_from(PathBuf::from(path)).ok();
     }
 
     if let Some(mut path) = home::home_dir() {
         path.push(".cargo");
-        return Some(path);
+        return Utf8PathBuf::try_from(path).ok();
     }
 
     None
 }
 
-fn lookup_in_path(exec: &str) -> Option<PathBuf> {
+fn lookup_in_path(exec: &str) -> Option<Utf8PathBuf> {
     let paths = env::var_os("PATH").unwrap_or_default();
-    env::split_paths(&paths).map(|path| path.join(exec)).find_map(probe_for_binary)
+    env::split_paths(&paths)
+        .map(|path| path.join(exec))
+        .map(PathBuf::from)
+        .map(Utf8PathBuf::try_from)
+        .filter_map(Result::ok)
+        .find_map(probe_for_binary)
 }
 
-pub fn probe_for_binary(path: PathBuf) -> Option<PathBuf> {
+pub fn probe_for_binary(path: Utf8PathBuf) -> Option<Utf8PathBuf> {
     let with_extension = match env::consts::EXE_EXTENSION {
         "" => None,
         it => Some(path.with_extension(it)),
diff --git a/crates/vfs-notify/src/lib.rs b/crates/vfs-notify/src/lib.rs
index 15a0ea5409a..94fd6cb78c9 100644
--- a/crates/vfs-notify/src/lib.rs
+++ b/crates/vfs-notify/src/lib.rs
@@ -13,7 +13,7 @@ use std::fs;
 
 use crossbeam_channel::{never, select, unbounded, Receiver, Sender};
 use notify::{Config, RecommendedWatcher, RecursiveMode, Watcher};
-use paths::{AbsPath, AbsPathBuf};
+use paths::{AbsPath, AbsPathBuf, Utf8Path};
 use vfs::loader;
 use walkdir::WalkDir;
 
@@ -205,7 +205,7 @@ impl NotifyActor {
                             if !entry.file_type().is_dir() {
                                 return true;
                             }
-                            let path = AbsPath::assert(entry.path());
+                            let path = AbsPath::assert(Utf8Path::from_path(entry.path()).unwrap());
                             root == path
                                 || dirs.exclude.iter().chain(&dirs.include).all(|it| it != path)
                         });
@@ -214,7 +214,7 @@ impl NotifyActor {
                         let depth = entry.depth();
                         let is_dir = entry.file_type().is_dir();
                         let is_file = entry.file_type().is_file();
-                        let abs_path = AbsPathBuf::assert(entry.into_path());
+                        let abs_path = AbsPathBuf::try_from(entry.into_path()).unwrap();
                         if depth < 2 && is_dir {
                             self.send(make_message(abs_path.clone()));
                         }
diff --git a/crates/vfs/src/vfs_path.rs b/crates/vfs/src/vfs_path.rs
index 52ada32bdfd..2d3fb9d88c8 100644
--- a/crates/vfs/src/vfs_path.rs
+++ b/crates/vfs/src/vfs_path.rs
@@ -326,7 +326,7 @@ impl VirtualPath {
     }
 
     fn strip_prefix(&self, base: &VirtualPath) -> Option<&RelPath> {
-        <_ as AsRef<std::path::Path>>::as_ref(&self.0)
+        <_ as AsRef<paths::Utf8Path>>::as_ref(&self.0)
             .strip_prefix(&base.0)
             .ok()
             .map(RelPath::new_unchecked)