Use env::temp_dir for constime base instead of storing relative to

project.

Also joins to the crate name now, just in case there's a collision
across two crates that for some reason have an identical constime!
invocation.

Author: codebycruz

README.md

@@ -60,6 +60,4 @@ fn main() {
 
 **You should get autocomplete and error feedback when using the macro.**
 
-This works with temporary files, which currently aren't automatically cleared.
-
-If you notice your project getting a little large, periodically run `cargo clean` to remove these.
+This by creating temporary binaries running each of your constime! invocations, stored in [`std::env::temp_dir()`](https://doc.rust-lang.org/std/env/fn.temp_dir.html)`.join("constime")`

src/lib.rs

@@ -34,34 +34,32 @@ pub fn comptime(mut code: TokenStream) -> TokenStream {
 		}
 	}
 
-	if out_dir.is_none() {
-		let out = std::env::current_dir().unwrap().join("target").join("debug").join("deps");
-		if out.exists() {
-			out_dir = Some(out);
-		}
-	}
-
 	let Some(out_dir) = out_dir else {
 		return build_error!("Could not find output directory.");
 	};
 
+	#[rustfmt::skip]
 	let wrapped_code = format!(r#"
 		fn main() {{
 			println!("{{:?}}", {{ {code} }});
 		}}
 	"#);
 
-	let hash = RandomState::new().hash_one(&wrapped_code);
+	let code_hash = RandomState::new().hash_one(&wrapped_code);
+	let crate_name = std::env::var("CARGO_PKG_NAME").unwrap_or_else(|_| "unknown".to_owned());
 
-	let constime_base = out_dir.join("constime");
+	// Join by crate_name in the rare case of identical blocks across crates
+	let constime_base = std::env::temp_dir().join("constime").join(crate_name);
 	if !constime_base.exists() {
-		std::fs::create_dir(&constime_base).unwrap();
+		if let Err(why) = std::fs::create_dir(&constime_base) {
+			return build_error!("Failed to create temp directory: {why}");
+		}
 	}
 
-	let evaluator_base = constime_base
-		.join(hash.to_string());
+	let evaluator_base = constime_base.join(code_hash.to_string());
 
-	if !evaluator_base.exists() { // This hasn't been compiled yet.
+	if !evaluator_base.exists() {
+		// This hasn't been compiled yet.
 		let mut rustc = std::process::Command::new("rustc");
 		rustc
 			.stderr(std::process::Stdio::piped())