Reorganize FFI code so less parts are exported public

tango-bench/src/dylib.rs

@@ -101,6 +101,22 @@ impl State {
     }
 }
 
+/// Global state of the benchmarking library
+static mut STATE: Option<State> = None;
+
+/// `tango_init()` implementation
+///
+/// This function is not exported from the library, but is used by the `tango_init()` functions
+/// generated by the `tango_benchmark!()` macro.
+pub unsafe fn __tango_init(benchmarks: Vec<Box<dyn MeasureTarget>>) {
+    if STATE.is_none() {
+        STATE = Some(State {
+            benchmarks,
+            selected_function: 0,
+        });
+    }
+}
+
 /// Defines all the foundation types and exported symbols for the FFI communication API between two
 /// executables.
 ///
@@ -137,9 +153,6 @@ pub mod ffi {
         const TANGO_FREE: FreeFn = tango_free;
     }
 
-    /// Global state of the benchmarking library
-    pub static mut STATE: Option<State> = None;
-
     #[no_mangle]
     unsafe extern "C" fn tango_count() -> usize {
         STATE.as_ref().map(|s| s.benchmarks.len()).unwrap_or(0)

tango-bench/src/lib.rs

@@ -61,23 +61,17 @@ pub enum Error {
 #[macro_export]
 macro_rules! tango_benchmarks {
     ($($func_expr:expr),+) => {
-
         /// Type checking tango_init() function
         const TANGO_INIT: $crate::dylib::ffi::InitFn = tango_init;
 
         /// Exported function for initializing the benchmark harness
         #[no_mangle]
         unsafe extern "C" fn tango_init() {
-            use $crate::dylib::{ffi::STATE, State};
-            if STATE.is_none() {
-                let mut benchmarks = vec![];
-                $(benchmarks.extend($crate::IntoBenchmarks::into_benchmarks($func_expr));)*
-                STATE = Some(State {
-                    benchmarks,
-                    selected_function: 0,
-                });
-            }
+            let mut benchmarks = vec![];
+            $(benchmarks.extend($crate::IntoBenchmarks::into_benchmarks($func_expr));)*
+            $crate::dylib::__tango_init(benchmarks)
         }
+
     };
 }