Test RDRAND

Signed-off-by: Joe Richey <[email protected]>

.github/workflows/tests.yml

@@ -38,8 +38,8 @@ jobs:
           toolchain: ${{ matrix.toolchain }}
       - uses: Swatinem/rust-cache@v2
       - run: cargo test
-      # Make sure enabling the std and custom features don't break anything
-      - run: cargo test --features=std,custom
+      # Ensure enabling features works, and run feature-specific tests.
+      - run: cargo test --features=std,custom,rdrand
       - run: cargo test --features=linux_disable_fallback
       - if: ${{ matrix.toolchain == 'nightly' }}
         run: cargo test --benches

src/lib.rs

@@ -224,6 +224,13 @@ mod util;
 mod custom;
 #[cfg(feature = "std")]
 mod error_impls;
+// If the rdrand feature is enabled, always bring in the rdrand module, so
+// that the RDRAND implementation can be tested.
+#[cfg(all(
+    any(target_env = "sgx", feature = "rdrand"),
+    any(target_arch = "x86_64", target_arch = "x86"),
+))]
+mod rdrand;
 
 pub use crate::error::Error;
 
@@ -330,10 +337,10 @@ cfg_if! {
     } else if #[cfg(windows)] {
         #[path = "windows.rs"] mod imp;
     } else if #[cfg(all(target_arch = "x86_64", target_env = "sgx"))] {
-        #[path = "rdrand.rs"] mod imp;
+        use rdrand as imp;
     } else if #[cfg(all(feature = "rdrand",
                         any(target_arch = "x86_64", target_arch = "x86")))] {
-        #[path = "rdrand.rs"] mod imp;
+        use rdrand as imp;
     } else if #[cfg(all(feature = "js",
                         any(target_arch = "wasm32", target_arch = "wasm64"),
                         target_os = "unknown"))] {

src/rdrand.rs

@@ -93,6 +93,7 @@ fn is_rdrand_good() -> bool {
     unsafe { self_test() }
 }
 
+#[allow(dead_code)]
 pub fn getrandom_inner(dest: &mut [MaybeUninit<u8>]) -> Result<(), Error> {
     static RDRAND_GOOD: LazyBool = LazyBool::new();
     if !RDRAND_GOOD.unsync_init(is_rdrand_good) {
@@ -121,3 +122,8 @@ unsafe fn rdrand_exact(dest: &mut [MaybeUninit<u8>]) -> Option<()> {
     }
     Some(())
 }
+
+#[cfg(test)]
+mod tests {
+    crate::tests::define_tests!(super::getrandom_inner);
+}