Fix msan failure in __repr__ when upgraded to NumPy 1.24.

PiperOrigin-RevId: 505661236
Change-Id: I37ea339679870d23886e3c95f51451349fa1de2c

python/mujoco/indexers.h

@@ -102,6 +102,7 @@ class MjModelGroupedViewsBase {
 
   int index() const { return index_; }
   const std::string& name() const { return name_; }
+  raw::MjModel* ptr() { return m_; }
 
  protected:
   int index_;
@@ -168,6 +169,7 @@ class MjDataGroupedViewsBase {
 
   int index() const { return index_; }
   const std::string& name() const { return name_; }
+  raw::MjData* ptr() { return d_; }
 
  protected:
   int index_;

python/mujoco/structs.cc

@@ -1551,7 +1551,7 @@ This is useful for example when the MJB is not available as a file on disk.)"));
     using GroupedViews = MjModelGroupedViews;                                  \
     py::class_<MjModelGroupedViews> groupedViews(m, "_" #MjModelGroupedViews); \
     FIELD_XMACROS                                                              \
-    groupedViews.def("__repr__", StructRepr<GroupedViews>);                    \
+    groupedViews.def("__repr__", MjModelStructRepr<GroupedViews>);             \
     groupedViews.def_property_readonly("id", [](GroupedViews& views) {         \
       return views.index();                                                    \
     });                                                                        \
@@ -1868,7 +1868,7 @@ This is useful for example when the MJB is not available as a file on disk.)"));
     using GroupedViews = MjDataGroupedViews;                                 \
     py::class_<MjDataGroupedViews> groupedViews(m, "_" #MjDataGroupedViews); \
     FIELD_XMACROS                                                            \
-    groupedViews.def("__repr__", StructRepr<GroupedViews>);                  \
+    groupedViews.def("__repr__", MjDataStructRepr<GroupedViews>);            \
     groupedViews.def_property_readonly("id", [](GroupedViews& views) {       \
       return views.index();                                                  \
     });                                                                      \

python/mujoco/structs.h

@@ -808,6 +808,25 @@ using MjvFigureWrapper = MjWrapper<raw::MjvFigure>;
 
 template <>
 struct enable_if_mj_struct<raw::MjvFigure> { using type = void; };
+
+#ifdef MEMORY_SANITIZER
+template <typename T>
+class ScopedMsanDisabler {
+ public:
+  ScopedMsanDisabler(T* mj)
+      : mj_(mj), shadow_(std::malloc(mj_->nbuffer)) {
+    __msan_copy_shadow(shadow_, mj_->buffer, mj_->nbuffer);
+    __msan_unpoison(mj_->buffer, mj_->nbuffer);
+  }
+  ~ScopedMsanDisabler() {
+    __msan_copy_shadow(mj_->buffer, shadow_, mj_->nbuffer);
+    std::free(shadow_);
+  }
+ private:
+  T* mj_;
+  void* shadow_;
+};
+#endif
 }  // namespace _impl
 
 template <typename T>
@@ -1078,6 +1097,24 @@ std::string StructRepr(pybind11::object self) {
   return result.str();
 }
 
+template <typename T>
+std::string MjModelStructRepr(pybind11::object self) {
+#ifdef MEMORY_SANITIZER
+  _impl::ScopedMsanDisabler<raw::MjModel> msan_disabler(
+      pybind11::cast<T&>(self).ptr());
+#endif
+  return StructRepr<T>(self);
+}
+
+template <typename T>
+std::string MjDataStructRepr(pybind11::object self) {
+#ifdef MEMORY_SANITIZER
+  _impl::ScopedMsanDisabler<raw::MjData> msan_disabler(
+      pybind11::cast<T&>(self).ptr());
+#endif
+  return StructRepr<T>(self);
+}
+
 template <typename C, typename... O>
 void DefineStructFunctions(pybind11::class_<C, O...> c) {
   c.def("__eq__", StructsEqual<C>);