Merge #135

135: Disable `mutable-noalias` r=stlankes a=mkroening

Fixes #128.

What do you think?

Co-authored-by: Martin Kröning <[email protected]>

Author: bors[bot]

hermit-sys/build.rs

@@ -89,18 +89,33 @@ fn build_hermit(src_dir: &Path, target_dir_opt: Option<&Path>) {
 		cmd.arg("vga");
 	}
 
+	let mut rustflags = Vec::new();
+	rustflags.push("-Zmutable-noalias=no".to_string());
+
 	#[cfg(feature = "instrument")]
 	{
-		cmd.env("RUSTFLAGS", "-Z instrument-mcount");
-		// if instrument is not set, ensure that instrument is not in environment variables!
-		cmd.env(
-			"RUSTFLAGS",
-			env::var("RUSTFLAGS")
-				.unwrap_or_else(|_| "".into())
-				.replace("-Z instrument-mcount", ""),
-		);
+		rustflags.push("-Zinstrument-mcount".to_string());
+		// Add outer `RUSTFLAGS` to command
+		if let Ok(var) = env::var("RUSTFLAGS") {
+			rustflags.push(var);
+		}
 	}
 
+	#[cfg(not(feature = "instrument"))]
+	{
+		// If the `instrument` feature feature is not enabled,
+		// filter it from outer `RUSTFLAGS` before adding them to the command.
+		if let Ok(var) = env::var("RUSTFLAGS") {
+			let flags = var
+				.split(',')
+				.filter(|&flag| !flag.contains("instrument-mcount"))
+				.map(String::from);
+			rustflags.extend(flags);
+		}
+	}
+
+	cmd.env("RUSTFLAGS", rustflags.join(","));
+
 	let output = cmd.output().expect("Unable to build kernel");
 	let stdout = std::string::String::from_utf8(output.stdout);
 	let stderr = std::string::String::from_utf8(output.stderr);