Decouple cache dir implementation from tests

Author: tuguzT

Cargo.lock

@@ -1,5 +1,6 @@
 [workspace]
 members = [
+	"crates/rustc_codegen_spirv-cache",
 	"crates/cargo-gpu",
 	"crates/xtask",
 ]
@@ -12,9 +13,17 @@ exclude = [
 
 resolver = "2"
 
+[workspace.package]
+version = "0.1.0"
+edition = "2021"
+repository = "https://github.com/Rust-GPU/cargo-gpu"
+keywords = ["gpu", "compiler", "rust-gpu"]
+license = "MIT OR Apache-2.0"
+
 [workspace.dependencies]
 spirv-builder = { git = "https://github.com/Rust-GPU/rust-gpu", rev = "3df836eb9d7b01344f52737bf9a310d1fb5a0c26", default-features = false }
 anyhow = "1.0.98"
+thiserror = "2.0.12"
 clap = { version = "4.5.41", features = ["derive"] }
 crossterm = "0.29.0"
 directories = "6.0.0"

Cargo.toml

@@ -1,22 +1,21 @@
 [package]
 name = "cargo-gpu"
-version = "0.1.0"
-edition = "2021"
 description = "Generates shader .spv files from rust-gpu shader crates"
-repository = "https://github.com/Rust-GPU/cargo-gpu"
 readme = "../../README.md"
-keywords = ["gpu", "compiler", "rust-gpu"]
-license = "MIT OR Apache-2.0"
+version.workspace = true
+edition.workspace = true
+repository.workspace = true
+keywords.workspace = true
+license.workspace = true
 default-run = "cargo-gpu"
-# See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
 
 [dependencies]
+rustc_codegen_spirv-cache = { path = "../rustc_codegen_spirv-cache", default-features = false }
 cargo_metadata.workspace = true
 anyhow.workspace = true
 spirv-builder = { workspace = true, features = ["clap", "watch"] }
 legacy_target_specs.workspace = true
 clap.workspace = true
-directories.workspace = true
 env_logger.workspace = true
 log.workspace = true
 relative-path.workspace = true
@@ -27,9 +26,10 @@ semver.workspace = true
 dunce.workspace = true
 
 [dev-dependencies]
+tempfile.workspace = true
 test-log.workspace = true
 cargo_metadata = { workspace = true, features = ["builder"] }
-cargo-util-schemas = "0.8.2"
+cargo-util-schemas.workspace = true
 
 [lints]
 workspace = true

crates/cargo-gpu/Cargo.toml

@@ -1,13 +1,18 @@
 //! Install a dedicated per-shader crate that has the `rust-gpu` compiler in it.
 
-use crate::spirv_source::{
-    get_channel_from_rustc_codegen_spirv_build_script, query_metadata, FindPackage as _,
-};
-use crate::target_specs::update_target_specs_files;
-use crate::{cache_dir, spirv_source::SpirvSource};
+use std::path::{Path, PathBuf};
+
 use anyhow::Context as _;
+use rustc_codegen_spirv_cache::cache::cache_dir;
 use spirv_builder::SpirvBuilder;
-use std::path::{Path, PathBuf};
+
+use crate::{
+    spirv_source::{
+        get_channel_from_rustc_codegen_spirv_build_script, query_metadata, FindPackage as _,
+        SpirvSource,
+    },
+    target_specs::update_target_specs_files,
+};
 
 /// Represents a functional backend installation, whether it was cached or just installed.
 #[derive(Clone, Debug, Default)]

crates/cargo-gpu/src/install.rs

@@ -50,8 +50,6 @@
 //! conduct other post-processing, like converting the `spv` files into `wgsl` files,
 //! for example.
 
-use anyhow::Context as _;
-
 use crate::dump_usage::dump_full_usage_for_readme;
 use build::Build;
 use show::Show;
@@ -166,26 +164,6 @@ pub struct Cli {
     pub command: Command,
 }
 
-/// The central cache directory of cargo gpu
-///
-/// # Errors
-/// may fail if we can't find the user home directory
-#[inline]
-pub fn cache_dir() -> anyhow::Result<std::path::PathBuf> {
-    let dir = directories::BaseDirs::new()
-        .with_context(|| "could not find the user home directory")?
-        .cache_dir()
-        .join("rust-gpu");
-
-    Ok(if cfg!(test) {
-        let thread_id = std::thread::current().id();
-        let id = format!("{thread_id:?}").replace('(', "-").replace(')', "");
-        dir.join("tests").join(id)
-    } else {
-        dir
-    })
-}
-
 /// Returns a string suitable to use as a directory.
 ///
 /// Created from the spirv-builder source dep and the rustc channel.

crates/cargo-gpu/src/lib.rs

@@ -1,11 +1,14 @@
 //! Display various information about `cargo gpu`, eg its cache directory.
 
-use crate::cache_dir;
-use crate::spirv_source::{query_metadata, SpirvSource};
-use crate::target_specs::update_target_specs_files;
+use std::{fs, path::Path};
+
 use anyhow::bail;
-use std::fs;
-use std::path::Path;
+use rustc_codegen_spirv_cache::cache::cache_dir;
+
+use crate::{
+    spirv_source::{query_metadata, SpirvSource},
+    target_specs::update_target_specs_files,
+};
 
 /// Show the computed source of the spirv-std dependency.
 #[derive(Clone, Debug, clap::Parser)]

crates/cargo-gpu/src/show.rs

@@ -4,12 +4,18 @@
 //! version. Then with that we `git checkout` the `rust-gpu` repo that corresponds to that version.
 //! From there we can look at the source code to get the required Rust toolchain.
 
+use std::{
+    fs,
+    path::{Path, PathBuf},
+};
+
 use anyhow::Context as _;
-use cargo_metadata::camino::{Utf8Path, Utf8PathBuf};
-use cargo_metadata::semver::Version;
-use cargo_metadata::{Metadata, MetadataCommand, Package};
-use std::fs;
-use std::path::{Path, PathBuf};
+use cargo_metadata::{
+    camino::{Utf8Path, Utf8PathBuf},
+    semver::Version,
+    Metadata, MetadataCommand, Package,
+};
+use rustc_codegen_spirv_cache::cache::cache_dir;
 
 #[expect(
     clippy::doc_markdown,
@@ -121,7 +127,7 @@ impl SpirvSource {
             } => Ok(rust_gpu_repo_root.as_std_path().to_owned()),
             Self::CratesIO { .. } | Self::Git { .. } => {
                 let dir = crate::to_dirname(self.to_string().as_ref());
-                Ok(crate::cache_dir()?.join("codegen").join(dir))
+                Ok(cache_dir()?.join("codegen").join(dir))
             }
         }
     }

crates/cargo-gpu/src/spirv_source.rs

@@ -22,11 +22,13 @@
 //!   was implemented, so we can support both old and new target specs without having to worry
 //!   which version of cargo gpu you are using. It'll "just work".
 
-use crate::cache_dir;
-use crate::spirv_source::{FindPackage as _, SpirvSource};
+use std::path::{Path, PathBuf};
+
 use anyhow::Context as _;
 use cargo_metadata::Metadata;
-use std::path::{Path, PathBuf};
+use rustc_codegen_spirv_cache::cache::cache_dir;
+
+use crate::spirv_source::{FindPackage as _, SpirvSource};
 
 /// Extract legacy target specs from our executable into some directory
 pub fn write_legacy_target_specs(target_spec_dir: &Path) -> anyhow::Result<()> {

crates/cargo-gpu/src/target_specs.rs

@@ -1,8 +1,8 @@
 //! utilities for tests
+
 #![cfg(test)]
 
-use crate::cache_dir;
-use std::io::Write as _;
+use std::{cell::RefCell, io::Write as _};
 
 fn copy_dir_all(
     src: impl AsRef<std::path::Path>,
@@ -20,16 +20,23 @@ fn copy_dir_all(
     }
     Ok(())
 }
-
 pub fn shader_crate_template_path() -> std::path::PathBuf {
     let project_base = std::path::PathBuf::from(env!("CARGO_MANIFEST_DIR"));
     project_base.join("../shader-crate-template")
 }
 
+thread_local! {
+    static TEMPDIR: RefCell<Option<tempfile::TempDir>> = RefCell::new(Some(
+        tempfile::TempDir::with_prefix("shader_crate").unwrap(),
+    ));
+}
+
 pub fn shader_crate_test_path() -> std::path::PathBuf {
-    let shader_crate_path = crate::cache_dir().unwrap().join("shader_crate");
-    copy_dir_all(shader_crate_template_path(), shader_crate_path.clone()).unwrap();
-    shader_crate_path
+    TEMPDIR.with_borrow(|tempdir| {
+        let shader_crate_path = tempdir.as_ref().unwrap().path();
+        copy_dir_all(shader_crate_template_path(), shader_crate_path).unwrap();
+        shader_crate_path.to_path_buf()
+    })
 }
 
 pub fn overwrite_shader_cargo_toml(shader_crate_path: &std::path::Path) -> std::fs::File {
@@ -45,9 +52,7 @@ pub fn overwrite_shader_cargo_toml(shader_crate_path: &std::path::Path) -> std::
 }
 
 pub fn tests_teardown() {
-    let cache_dir = cache_dir().unwrap();
-    if !cache_dir.exists() {
-        return;
-    }
-    std::fs::remove_dir_all(cache_dir).unwrap();
+    TEMPDIR.with_borrow_mut(|tempdir| {
+        tempdir.take().unwrap().close().unwrap();
+    });
 }

crates/cargo-gpu/src/test.rs

@@ -0,0 +1,15 @@
+[package]
+name = "rustc_codegen_spirv-cache"
+description = "Cacher of `rust-gpu` codegen for required toolchain"
+version.workspace = true
+edition.workspace = true
+repository.workspace = true
+keywords.workspace = true
+license.workspace = true
+
+[dependencies]
+thiserror.workspace = true
+directories.workspace = true
+
+[lints]
+workspace = true