mujoco

// Copyright 2026 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.

// Tests for X macros in mjspecmacro.h.

#include <cstddef>
#include <type_traits>

#include <gtest/gtest.h>
#include <mujoco/mjspec.h>
#include <mujoco/mjspecmacro.h>

namespace mujoco {
namespace {

namespace expected {
#define X(type, name, dim) type name;
#define XVEC(type, name, dim) type name[dim];

struct mjsElement {
  MJSELEMENT_FIELDS
};
struct mjsCompiler {
  MJSCOMPILER_FIELDS
};
struct mjSpec {
  MJSPEC_FIELDS
  mjsAuthored authored;
};
struct mjsOrientation {
  MJSORIENTATION_FIELDS
};
struct mjsPlugin {
  MJSPLUGIN_FIELDS
};
struct mjsBody {
  MJSBODY_FIELDS
};
struct mjsFrame {
  MJSFRAME_FIELDS
};
struct mjsJoint {
  MJSJOINT_FIELDS
};
struct mjsGeom {
  MJSGEOM_FIELDS
};
struct mjsSite {
  MJSSITE_FIELDS
};
struct mjsCamera {
  MJSCAMERA_FIELDS
};
struct mjsLight {
  MJSLIGHT_FIELDS
};
struct mjsFlex {
  MJSFLEX_FIELDS
};
struct mjsMesh {
  MJSMESH_FIELDS
};
struct mjsHField {
  MJSHFIELD_FIELDS
};
struct mjsSkin {
  MJSSKIN_FIELDS
};
struct mjsTexture {
  MJSTEXTURE_FIELDS
};
struct mjsMaterial {
  MJSMATERIAL_FIELDS
};
struct mjsPair {
  MJSPAIR_FIELDS
};
struct mjsExclude {
  MJSEXCLUDE_FIELDS
};
struct mjsEquality {
  MJSEQUALITY_FIELDS
};
struct mjsTendon {
  MJSTENDON_FIELDS
};
struct mjsWrap {
  MJSWRAP_FIELDS
};
struct mjsActuator {
  MJSACTUATOR_FIELDS
};
struct mjsSensor {
  MJSSENSOR_FIELDS
};
struct mjsNumeric {
  MJSNUMERIC_FIELDS
};
struct mjsText {
  MJSTEXT_FIELDS
};
struct mjsTuple {
  MJSTUPLE_FIELDS
};
struct mjsKey {
  MJSKEY_FIELDS
};
struct mjsDefault {
  MJSDEFAULT_FIELDS
};

#undef XVEC
#undef X
}  // namespace expected

template <typename T, size_t N>
struct ArrayOrScalar {
  using type = T[N];
};
template <typename T>
struct ArrayOrScalar<T, 1> {
  using type = T;
};
template <typename T, size_t N>
using ArrayOrScalarT = typename ArrayOrScalar<T, N>::type;

#define XIMPL(type, name, dim)                                                \
  static_assert(                                                              \
      std::is_same_v<decltype(RealStruct::name), ArrayOrScalarT<type, dim>>,  \
      "Type mismatch for " #name);                                            \
  static_assert(offsetof(RealStruct, name) == offsetof(ExpectedStruct, name), \
                "Offset mismatch for " #name);

#define X(type, name, dim)                                   \
  static_assert(dim == 1, "use XVEC for non-scalar fields"); \
  XIMPL(type, name, dim)

#define XVEC(type, name, dim)                        \
  static_assert(dim > 1, "use X for scalar fields"); \
  XIMPL(type, name, dim)

#define CHECK_STRUCT(Name, Macro)                                 \
  struct Check##Name {                                            \
    using RealStruct = Name;                                      \
    using ExpectedStruct = expected::Name;                        \
    static_assert(sizeof(RealStruct) == sizeof(ExpectedStruct),   \
                  "sizeof mismatch for " #Name);                  \
    static_assert(alignof(RealStruct) == alignof(ExpectedStruct), \
                  "alignof mismatch for " #Name);                 \
    Macro                                                         \
  };

CHECK_STRUCT(mjsElement, MJSELEMENT_FIELDS)
CHECK_STRUCT(mjsCompiler, MJSCOMPILER_FIELDS)
CHECK_STRUCT(mjSpec, MJSPEC_FIELDS)
CHECK_STRUCT(mjsOrientation, MJSORIENTATION_FIELDS)
CHECK_STRUCT(mjsPlugin, MJSPLUGIN_FIELDS)
CHECK_STRUCT(mjsBody, MJSBODY_FIELDS)
CHECK_STRUCT(mjsFrame, MJSFRAME_FIELDS)
CHECK_STRUCT(mjsJoint, MJSJOINT_FIELDS)
CHECK_STRUCT(mjsGeom, MJSGEOM_FIELDS)
CHECK_STRUCT(mjsSite, MJSSITE_FIELDS)
CHECK_STRUCT(mjsCamera, MJSCAMERA_FIELDS)
CHECK_STRUCT(mjsLight, MJSLIGHT_FIELDS)
CHECK_STRUCT(mjsFlex, MJSFLEX_FIELDS)
CHECK_STRUCT(mjsMesh, MJSMESH_FIELDS)
CHECK_STRUCT(mjsHField, MJSHFIELD_FIELDS)
CHECK_STRUCT(mjsSkin, MJSSKIN_FIELDS)
CHECK_STRUCT(mjsTexture, MJSTEXTURE_FIELDS)
CHECK_STRUCT(mjsMaterial, MJSMATERIAL_FIELDS)
CHECK_STRUCT(mjsPair, MJSPAIR_FIELDS)
CHECK_STRUCT(mjsExclude, MJSEXCLUDE_FIELDS)
CHECK_STRUCT(mjsEquality, MJSEQUALITY_FIELDS)
CHECK_STRUCT(mjsTendon, MJSTENDON_FIELDS)
CHECK_STRUCT(mjsWrap, MJSWRAP_FIELDS)
CHECK_STRUCT(mjsActuator, MJSACTUATOR_FIELDS)
CHECK_STRUCT(mjsSensor, MJSSENSOR_FIELDS)
CHECK_STRUCT(mjsNumeric, MJSNUMERIC_FIELDS)
CHECK_STRUCT(mjsText, MJSTEXT_FIELDS)
CHECK_STRUCT(mjsTuple, MJSTUPLE_FIELDS)
CHECK_STRUCT(mjsKey, MJSKEY_FIELDS)
CHECK_STRUCT(mjsDefault, MJSDEFAULT_FIELDS)

#undef CHECK_STRUCT
#undef XVEC
#undef X
#undef XIMPL

TEST(MjspecmacroTest, CompileTimeChecks) {
  // Verifies that the test compiled successfully and all static_asserts passed.
  EXPECT_TRUE(true);
}

}  // namespace
}  // namespace mujoco