feat: added opt level to build.rs

build.rs

@@ -117,6 +117,12 @@ fn main() {
         &env::var("PROFILE").unwrap_or(String::from("UNKNOWN")),
     );
 
+    write_str_constant(
+        &mut file,
+        "OPT_LEVEL",
+        &env::var("OPT_LEVEL").unwrap_or(String::from("UNKNOWN")),
+    );
+
     write_str_constant(
         &mut file,
         "MAKEFLAGS",

src/gen/mock.rs

@@ -9,6 +9,7 @@ pub const COMPILER_VERSION: &str = "x.x.x";
 pub const HOST: &str = "-";
 pub const TARGET: &str = "-";
 pub const PROFILE: &str = "-";
+pub const OPT_LEVEL: &str = "-";
 pub const MAKEFLAGS: &str = "-";
 pub const FEATURES: [&str; 1] = ["cpu"];
 pub const PLATFORM_CPU_BITS: &str = "64";