watch support, broken on windows

Author: Firestar99

Cargo.lock

@@ -1,19 +1,19 @@
 [workspace]
 members = [
-    "crates/cargo-gpu", 
-		"crates/xtask",
+	"crates/cargo-gpu",
+	"crates/xtask",
 ]
 
 exclude = [
-    # This currently needs to be excluded because it depends on a version of `rust-gpu` that
-    # uses a toolchain whose Cargo version doesn't recognise version 4 of `Cargo.lock`.
-    "crates/shader-crate-template"
+	# This currently needs to be excluded because it depends on a version of `rust-gpu` that
+	# uses a toolchain whose Cargo version doesn't recognise version 4 of `Cargo.lock`.
+	"crates/shader-crate-template"
 ]
 
 resolver = "2"
 
 [workspace.dependencies]
-spirv-builder = { git = "https://github.com/Rust-GPU/rust-gpu.git", rev = "eca83dfbfc0aae5c72f1e3f53081f5ccb72c27a4", default-features = false }
+spirv-builder = { git = "https://github.com/Rust-GPU/rust-gpu.git", rev = "0c7f509f7da93d0bd12d51230d15a07d0152c593", default-features = false }
 anyhow = "1.0.94"
 clap = { version = "4.5.37", features = ["derive"] }
 crossterm = "0.28.1"

Cargo.toml

@@ -13,7 +13,7 @@ default-run = "cargo-gpu"
 [dependencies]
 cargo_metadata.workspace = true
 anyhow.workspace = true
-spirv-builder = { workspace = true, features = ["clap"] }
+spirv-builder = { workspace = true, features = ["clap", "watch"] }
 clap.workspace = true
 directories.workspace = true
 env_logger.workspace = true

crates/cargo-gpu/Cargo.toml

@@ -7,11 +7,11 @@ use crate::linkage::Linkage;
 use crate::lockfile::LockfileMismatchHandler;
 use crate::{install::Install, target_spec_dir};
 use anyhow::Context as _;
-use spirv_builder::ModuleResult;
+use spirv_builder::{CompileResult, ModuleResult};
 use std::io::Write as _;
 
 /// `cargo build` subcommands
-#[derive(clap::Parser, Debug, serde::Deserialize, serde::Serialize)]
+#[derive(Clone, clap::Parser, Debug, serde::Deserialize, serde::Serialize)]
 pub struct Build {
     /// CLI args for install the `rust-gpu` compiler and components
     #[clap(flatten)]
@@ -69,10 +69,21 @@ impl Build {
                 "Compiling shaders at {}...\n",
                 self.install.spirv_install.shader_crate.display()
             );
+            let result = self.build_args.spirv_builder.build()?;
+            self.parse_compilation_result(result)?;
+            Ok(())
+        } else {
+            let this = self.clone();
+            self.build_args.spirv_builder.watch(move |result| {
+                this.parse_compilation_result(result)
+                    .expect("watch operation failed")
+            })?;
+            std::thread::park();
+            Ok(())
         }
+    }
 
-        let result = self.build_args.spirv_builder.build()?;
-
+    fn parse_compilation_result(&self, result: CompileResult) -> anyhow::Result<()> {
         let shaders = match &result.module {
             ModuleResult::MultiModule(modules) => {
                 anyhow::ensure!(!modules.is_empty(), "No shader modules were compiled");

crates/cargo-gpu/src/build.rs

@@ -12,7 +12,7 @@ use std::io::Write as _;
 use std::path::{Path, PathBuf};
 
 /// `cargo gpu install`
-#[derive(clap::Parser, Debug, serde::Deserialize, serde::Serialize)]
+#[derive(Clone, clap::Parser, Debug, serde::Deserialize, serde::Serialize)]
 pub struct Install {
     /// CLI arguments for installing the Rust toolchain and components
     #[clap(flatten)]