Add watch feature for cargo-gpu library

Author: tuguzT

crates/cargo-gpu-cli/Cargo.toml

@@ -14,7 +14,7 @@ name = "cargo-gpu"
 path = "src/main.rs"
 
 [dependencies]
-cargo-gpu = { path = "../cargo-gpu", features = ["clap"] }
+cargo-gpu = { path = "../cargo-gpu", features = ["watch", "clap"] }
 clap.workspace = true
 log.workspace = true
 env_logger.workspace = true

crates/cargo-gpu/Cargo.toml

@@ -11,7 +11,7 @@ license.workspace = true
 [dependencies]
 cargo_metadata.workspace = true
 anyhow.workspace = true
-spirv-builder = { workspace = true, features = ["watch"] }
+spirv-builder.workspace = true
 legacy_target_specs.workspace = true
 clap = { workspace = true, optional = true }
 directories.workspace = true
@@ -29,6 +29,7 @@ cargo_metadata = { workspace = true, features = ["builder"] }
 cargo-util-schemas.workspace = true
 
 [features]
+watch = ["spirv-builder/watch"]
 clap = ["dep:clap", "spirv-builder/clap"]
 
 [lints]

crates/cargo-gpu/src/build.rs

@@ -2,13 +2,21 @@
 #![allow(clippy::unwrap_used, reason = "this is basically a test")]
 //! `cargo gpu build`, analogous to `cargo build`
 
-use crate::install::Install;
-use crate::linkage::Linkage;
-use crate::lockfile::LockfileMismatchHandler;
+use spirv_builder::SpirvBuilder;
+use std::path::PathBuf;
+
+#[cfg(feature = "watch")]
 use anyhow::Context as _;
-use spirv_builder::{CompileResult, ModuleResult, SpirvBuilder};
+#[cfg(feature = "watch")]
+use spirv_builder::{CompileResult, ModuleResult};
+#[cfg(feature = "watch")]
 use std::io::Write as _;
-use std::path::PathBuf;
+
+use crate::install::Install;
+use crate::lockfile::LockfileMismatchHandler;
+
+#[cfg(feature = "watch")]
+use crate::linkage::Linkage;
 
 /// Args for just a build
 #[derive(Debug, Clone, serde::Deserialize, serde::Serialize)]
@@ -19,6 +27,7 @@ pub struct BuildArgs {
     pub output_dir: PathBuf,
 
     /// Watch the shader crate directory and automatically recompile on changes.
+    #[cfg(feature = "watch")]
     #[cfg_attr(feature = "clap", clap(long, short, action))]
     pub watch: bool,
 
@@ -37,6 +46,7 @@ impl Default for BuildArgs {
     fn default() -> Self {
         Self {
             output_dir: PathBuf::from("./"),
+            #[cfg(feature = "watch")]
             watch: false,
             spirv_builder: SpirvBuilder::default(),
             manifest_file: String::from("manifest.json"),
@@ -91,6 +101,7 @@ impl Build {
             std::env::current_dir()?.display()
         );
 
+        #[cfg(feature = "watch")]
         if self.build.watch {
             let this = self.clone();
             self.build
@@ -111,10 +122,12 @@ impl Build {
             let result = self.build.spirv_builder.build()?;
             self.parse_compilation_result(&result)?;
         }
+
         Ok(())
     }
 
     /// Parses compilation result from `SpirvBuilder` and writes it out to a file
+    #[cfg(feature = "watch")]
     fn parse_compilation_result(&self, result: &CompileResult) -> anyhow::Result<()> {
         let shaders = match &result.module {
             ModuleResult::MultiModule(modules) => {

crates/cargo-gpu/src/lib.rs

@@ -144,12 +144,14 @@ impl Command {
                     config::Config::clap_command_with_cargo_config(shader_crate_path, env_args)?;
                 log::debug!("building with final merged arguments: {command:#?}");
 
-                //  When watching, do one normal run to setup the `manifest.json` file.
+                // When watching, do one normal run to setup the `manifest.json` file.
+                #[cfg(feature = "watch")]
                 if command.build.watch {
                     command.build.watch = false;
                     command.run()?;
                     command.build.watch = true;
                 }
+
                 command.run()?;
             }
             Self::Show(show) => show.run()?,

crates/cargo-gpu/src/linkage.rs

@@ -1,5 +1,7 @@
 //! Mainly for the Linkage struct, which is written to a json file.
 
+#![cfg(feature = "watch")]
+
 /// Shader source and entry point that can be used to create shader linkage.
 #[derive(serde::Serialize, Clone, Debug, PartialEq, Eq, PartialOrd, Ord)]
 pub struct Linkage {