Run tests under miri on CI

.github/workflows/ci.yaml

@@ -161,6 +161,21 @@ jobs:
         run: python -m pip install flake8
       - name: run lint
         run: flake8 . --count --exclude=./.*,./Lib,./vm/Lib  --select=E9,F63,F7,F82 --show-source --statistics
+  miri:
+    name: Run tests under miri
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@master
+      - uses: actions-rs/toolchain@v1
+        with:
+            profile: minimal
+            toolchain: nightly
+            components: miri
+            override: true
+      - name: Run tests under miri
+        # miri-ignore-leaks because the type-object circular reference means that there will always be
+        # a memory leak, at least until we have proper cyclic gc
+        run: MIRIFLAGS='-Zmiri-ignore-leaks' cargo +nightly miri test -p rustpython-vm -- miri_test
 
   wasm:
     name: Check the WASM package and demo

vm/src/builtins/dict.rs

@@ -597,7 +597,7 @@ macro_rules! dict_iterator {
                 let s = if let Some(_guard) = ReprGuard::enter(vm, zelf.as_object()) {
                     let mut str_parts = vec![];
                     for (key, value) in zelf.dict.clone() {
-                        let s = vm.to_repr(&$result_fn(vm, key, value))?;
+                        let s = vm.to_repr(&($result_fn)(vm, key, value))?;
                         str_parts.push(s.borrow_value().to_owned());
                     }
                     format!("{}([{}])", $class_name, str_parts.join(", "))
@@ -694,7 +694,7 @@ macro_rules! dict_iterator {
                 match zelf.dict.entries.next_entry(&mut position) {
                     Some((key, value)) => {
                         zelf.position.store(position);
-                        Ok($result_fn(vm, key, value))
+                        Ok(($result_fn)(vm, key, value))
                     }
                     None => Err(vm.new_stop_iteration()),
                 }
@@ -743,7 +743,7 @@ macro_rules! dict_iterator {
                 match zelf.dict.len().checked_sub(count) {
                     Some(mut pos) => {
                         let (key, value) = zelf.dict.entries.next_entry(&mut pos).unwrap();
-                        Ok($result_fn(vm, key, value))
+                        Ok(($result_fn)(vm, key, value))
                     }
                     None => {
                         zelf.position.store(std::isize::MAX as usize);

vm/src/pyobjectrc.rs

@@ -517,7 +517,7 @@ pub(crate) fn init_type_hierarchy() -> (PyTypeRef, PyTypeRef) {
 mod tests {
     use super::*;
     #[test]
-    fn test_type_initialization() {
+    fn miri_test_type_initialization() {
         let _ = init_type_hierarchy();
     }
 }