Initial open sourcing of MuJoCo.

PiperOrigin-RevId: 450374687
Change-Id: Ie3225a46ce095fc28ae8e63c326a640261f562bb

src/engine/engine_array_safety.h

@@ -0,0 +1,31 @@
+// Copyright 2021 DeepMind Technologies Limited
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#ifndef MUJOCO_SRC_ENGINE_ENGINE_ARRAY_SAFETY_H_
+#define MUJOCO_SRC_ENGINE_ENGINE_ARRAY_SAFETY_H_
+
+#include <stdio.h>
+#include <string.h>
+
+// Evaluates to sizeof(arr) if arr is a char array, and emits a compiler error
+// otherwise. In particular, emits a compiler error if arr is a char*.
+#define mjSIZEOFARRAY(arr) _Generic(&(arr), char(*)[sizeof(arr)]: sizeof(arr))
+
+#define mjSNPRINTF(dest, ...) snprintf(dest, mjSIZEOFARRAY(dest), __VA_ARGS__)
+
+#define mjSTRNCAT(dest, src) strncat(dest, src, mjSIZEOFARRAY(dest) - strlen(dest) - 1)
+
+#define mjSTRNCPY(dest, src) mju_strncpy(dest, src, mjSIZEOFARRAY(dest))
+
+#endif  // MUJOCO_SRC_ENGINE_ENGINE_ARRAY_SAFETY_H_