install-crate: move install action to new cargo-gpu-install crate

Author: Firestar99

Cargo.lock

@@ -1,6 +1,7 @@
 [workspace]
 members = [
 	"crates/cargo-gpu",
+	"crates/cargo-gpu-install",
 	"crates/xtask",
 ]
 
@@ -24,6 +25,7 @@ license = "MIT OR Apache-2.0"
 
 [workspace.dependencies]
 spirv-builder = { git = "https://github.com/Rust-GPU/rust-gpu", rev = "a30bd43db45f2bfe260051f44141e5eaffcbb4b0", default-features = false }
+cargo-gpu-install = { path = "./crates/cargo-gpu-install" }
 anyhow = "1.0.98"
 clap = { version = "4.5.41", features = ["derive"] }
 crossterm = "0.29.0"

Cargo.toml

@@ -0,0 +1,36 @@
+[package]
+name = "cargo-gpu-install"
+version.workspace = true
+edition.workspace = true
+description = "Install rust-gpu and it's required toolchain automatically"
+repository.workspace = true
+readme.workspace = true
+keywords.workspace = true
+license.workspace = true
+
+[features]
+test = ["dep:tempfile"]
+
+[dependencies]
+cargo_metadata.workspace = true
+anyhow.workspace = true
+spirv-builder = { workspace = true, features = ["clap", "watch"] }
+clap.workspace = true
+directories.workspace = true
+env_logger.workspace = true
+log.workspace = true
+relative-path.workspace = true
+serde.workspace = true
+serde_json.workspace = true
+crossterm.workspace = true
+semver.workspace = true
+dunce.workspace = true
+tempfile = { workspace = true, optional = true }
+
+[dev-dependencies]
+test-log.workspace = true
+cargo_metadata = { workspace = true, features = ["builder"] }
+cargo-util-schemas = "0.8.2"
+
+[lints]
+workspace = true

crates/cargo-gpu-install/Cargo.toml

@@ -0,0 +1,43 @@
+# cargo-gpu-install
+
+`cargo-gpu-install` is the install action of `cargo-gpu`, separated into its own crate. It's intended to be used
+by build scripts and other binaries that need automated installation of rust-gpu and it's required toolchain,
+without having to pull all the other cli dependencies of the full `cargo-gpu` (like clap).
+
+## Example
+
+This is an example build script meant to be placed in your "main" std crate, to build a secondary no-std "shader" crate.
+But you can just as well use this in your executable directly, with some minor adjustments.
+```rust,no_run
+# use std::path::PathBuf;
+# use cargo_gpu_install::install::Install;
+# use cargo_gpu_install::spirv_builder::SpirvMetadata;
+
+pub fn main() -> Result<(), Box<dyn std::error::Error>> {
+    // path to your shader crate
+    let shader_crate = PathBuf::from("./shaders");
+
+    // install the toolchain and build the `rustc_codegen_spirv` codegen backend with it
+    let backend = Install::from_shader_crate(shader_crate.clone()).run()?;
+
+    // build the shader crate
+    let mut builder = backend.to_spirv_builder(shader_crate, "spirv-unknown-vulkan1.2");
+    // set to true when you're in a build script, false when outside one
+    builder.build_script.defaults = true;
+    // enable debug information in the shaders
+    builder.spirv_metadata = SpirvMetadata::Full;
+    let spv_result = builder.build()?;
+    let path_to_spv = spv_result.module.unwrap_single();
+
+    // emit path to the artifact into env var, use it anywhere in your crate like:
+    // > include_str!(env!("MY_SHADER_PATH"))
+    println!(
+        "cargo::rustc-env=MY_SHADER_PATH={}",
+        path_to_spv.display()
+    );
+
+    // you could also generate some rust source code into the `std::env::var("OUT_DIR")` dir
+    // and use `include!(concat!(env!("OUT_DIR"), "/shader_symbols.rs"));` to include it
+    Ok(())
+}
+```

crates/cargo-gpu-install/README.md

@@ -0,0 +1,64 @@
+#![expect(clippy::pub_use, reason = "pub use for build scripts")]
+#![doc = include_str!("../README.md")]
+
+pub mod install;
+mod install_toolchain;
+pub mod spirv_source;
+pub mod test;
+
+pub use spirv_builder;
+
+/// Central function to write to the user.
+#[macro_export]
+macro_rules! user_output {
+    ($($args: tt)*) => { {
+        #[allow(
+            clippy::allow_attributes,
+            clippy::useless_attribute,
+            unused_imports,
+            reason = "`std::io::Write` is only sometimes called??"
+        )]
+        use std::io::Write as _;
+
+        #[expect(
+            clippy::non_ascii_literal,
+            reason = "CRAB GOOD. CRAB IMPORTANT."
+        )]
+        {
+            print!("🦀 ");
+        }
+        print!($($args)*);
+        std::io::stdout().flush().unwrap();
+   } }
+}
+
+/// The central cache directory of cargo gpu
+///
+/// # Errors
+/// may fail if we can't find the user home directory
+#[inline]
+#[cfg(not(test))]
+#[expect(clippy::cfg_not_test, reason = "tests use different cache_dir")]
+pub fn cache_dir() -> anyhow::Result<std::path::PathBuf> {
+    use anyhow::Context as _;
+    Ok(directories::BaseDirs::new()
+        .with_context(|| "could not find the user home directory")?
+        .cache_dir()
+        .join("rust-gpu"))
+}
+
+#[cfg(test)]
+pub use test::test_cache_dir as cache_dir;
+
+/// Returns a string suitable to use as a directory.
+///
+/// Created from the spirv-builder source dep and the rustc channel.
+fn to_dirname(text: &str) -> String {
+    text.replace(
+        [std::path::MAIN_SEPARATOR, '\\', '/', '.', ':', '@', '='],
+        "_",
+    )
+    .split(['{', '}', ' ', '\n', '"', '\''])
+    .collect::<Vec<_>>()
+    .concat()
+}

crates/cargo-gpu/src/install.rs crates/cargo-gpu-install/src/install.rscrates/cargo-gpu/src/install.rs renamed to crates/cargo-gpu-install/src/install.rs

@@ -1,5 +1,5 @@
 //! utilities for tests
-#![cfg(test)]
+#![cfg(any(feature = "test", test))]
 
 use anyhow::Context;
 use std::cell::RefCell;

crates/cargo-gpu/src/install_toolchain.rs …rgo-gpu-install/src/install_toolchain.rscrates/cargo-gpu/src/install_toolchain.rs renamed to crates/cargo-gpu-install/src/install_toolchain.rs crates/cargo-gpu/src/install_toolchain.rs renamed to crates/cargo-gpu-install/src/install_toolchain.rs

@@ -14,6 +14,7 @@ default-run = "cargo-gpu"
 cargo_metadata.workspace = true
 anyhow.workspace = true
 spirv-builder = { workspace = true, features = ["clap", "watch"] }
+cargo-gpu-install.workspace = true
 clap.workspace = true
 directories.workspace = true
 env_logger.workspace = true
@@ -26,6 +27,7 @@ semver.workspace = true
 dunce.workspace = true
 
 [dev-dependencies]
+cargo-gpu-install = { workspace = true, features = ["test"] }
 tempfile.workspace = true
 test-log.workspace = true
 cargo_metadata = { workspace = true, features = ["builder"] }