Merge pull request #67 from NULLx76/miri

Add Miri test to CI and Fix undefined behaviour in a test
NULLx76 · Oct 16, 2022 · 7dc4baa · 7dc4baa
2 parents 50b935b + f0554ba
commit 7dc4baa
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Showing 2 changed files with 40 additions and 19 deletions.
diff --git a/.github/workflows/rust.yml b/.github/workflows/rust.yml
@@ -55,7 +55,7 @@ jobs:
     steps:
     - uses: actions/checkout@v2
 
-    - name: Install nightly toolchain
+    - name: Install beta toolchain
       uses: actions-rs/toolchain@v1
       with:
         profile: minimal
@@ -84,7 +84,7 @@ jobs:
     steps:
     - uses: actions/checkout@v2
 
-    - name: Install stable toolchain
+    - name: Install nightly toolchain
       uses: actions-rs/toolchain@v1
       with:
         toolchain: nightly
@@ -96,6 +96,19 @@ jobs:
         command: test
         args: --all-features
 
+  test-miri:
+    name: Test Miri
+    runs-on: ubuntu-latest
+    steps:
+    - uses: actions/checkout@v3
+    - name: Install Miri
+      run: |
+        rustup toolchain install nightly --component miri
+        rustup override set nightly
+        cargo miri setup
+    - name: Test with Miri
+      run: cargo miri test
+
   build-no-std:
     name: Build no-std
     runs-on: ubuntu-latest
@@ -113,4 +126,4 @@ jobs:
       uses: actions-rs/cargo@v1
       with:
         command: build
-        args: --target thumbv7em-none-eabihf --all-features
+        args: --target thumbv7em-none-eabihf --all-features
diff --git a/src/lib.rs b/src/lib.rs
@@ -852,6 +852,8 @@ mod tests {
     }
 
     #[test]
+    #[cfg_attr(miri, ignore)]
+    // this test takes far too long with Miri enabled
     fn run_test_push_dequeue_push_full_get_rep() {
         fn test_push_dequeue_push_full_get_rep(mut rb: impl RingBufferExt<i32>) {
             for _ in 0..100_000 {
@@ -973,24 +975,30 @@ mod tests {
         }
 
         macro_rules! test_dropped {
-            ($constructor: block) => {
+            ($constructor: block) => {{
+                let dt = Box::into_raw(Box::new(RefCell::new(DropTest { flag: false })));
                 {
-                    let dt = Box::leak(Box::new(RefCell::new(DropTest { flag: false })));
-                    {
-                        let d = Dropee { parent: Some(dt.borrow_mut()) };
-                        let mut rb = { $constructor };
-                        rb.push(d);
-                        rb.push(Dropee { parent: None });
-                    }
-                    assert!(dt.borrow_mut().flag);
-                    unsafe {
-                        // SAFETY: we know Dropee, which needed the static lifetime, has been dropped (by the assert)
-                        // we could probably skip this, but this makes sure we don't leak any memory
-                        let ptr: *mut RefCell<DropTest> = std::mem::transmute::<&RefCell<DropTest>, _>(dt);
-                        drop(Box::from_raw(ptr));
-                    }
+                    let d = Dropee {
+                        // Safety:
+                        // We know the pointer is initialized as it was created just above.
+                        // Also no other mutable borrow can exist at this time
+                        parent: Some(unsafe { dt.as_ref() }.unwrap().borrow_mut()),
+                    };
+                    let mut rb = { $constructor };
+                    rb.push(d);
+                    rb.push(Dropee { parent: None });
                 }
-            };
+                {
+                    // Safety:
+                    // We know the pointer exists and is no longer borrowed as the block above limited it
+                    assert!(unsafe { dt.as_ref() }.unwrap().borrow().flag);
+                }
+                // Safety:
+                // No other references exist to box so we can safely drop it
+                unsafe {
+                    drop(Box::from_raw(dt));
+                }
+            }};
         }
 
         #[test]