Merge pull request #35 from Rust-GPU/feature/show-commitsh

Show git commit revision command

crates/cargo-gpu/Cargo.toml

@@ -6,6 +6,7 @@ description = "Generates shader .spv files from rust-gpu shader crates"
 repository = "https://github.com/Rust-GPU/cargo-gpu"
 readme = "../../README.md"
 keywords = ["gpu", "compiler"]
+build = "build.rs"
 # See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
 
 [dependencies]

crates/cargo-gpu/build.rs

@@ -0,0 +1,12 @@
+//! cargo-gpu build script.
+
+fn main() {
+    let git_hash = std::process::Command::new("git")
+        .args(["rev-parse", "HEAD"])
+        .output()
+        .map_or_else(
+            |_| "unknown".to_owned(),
+            |output| String::from_utf8(output.stdout).unwrap_or_else(|_| "unknown".to_owned()),
+        );
+    println!("cargo:rustc-env=GIT_HASH={git_hash}");
+}

crates/cargo-gpu/src/show.rs

@@ -17,6 +17,8 @@ pub enum Info {
     CacheDirectory,
     /// The source location of spirv-std
     SpirvSource(SpirvSourceDep),
+    /// The git commitsh of this cli tool.
+    Commitsh,
 }
 
 /// `cargo gpu show`
@@ -48,6 +50,9 @@ impl Show {
                     println!("{rust_gpu_source}\n");
                 }
             }
+            Info::Commitsh => {
+                println!("{}", std::env!("GIT_HASH"));
+            }
         }
 
         Ok(())