JoltC/JoltCImpl/Test.cpp

// Defines macros used for statically verifying the JoltC bindings against the
// Jolt Physics C++ types.
//
// When the JoltC.h header is normally included, these macros are defined to do
// nothing.

#include <assert.h>
#include <stddef.h>
#include <type_traits>

#include <Jolt/Jolt.h>

#include <Jolt/Core/Factory.h>
#include <Jolt/Core/JobSystemThreadPool.h>
#include <Jolt/Core/TempAllocator.h>
#include <Jolt/Physics/Body/BodyActivationListener.h>
#include <Jolt/Physics/Body/BodyCreationSettings.h>
#include <Jolt/Physics/Body/BodyManager.h>
#include <Jolt/Physics/Collision/ActiveEdgeMode.h>
#include <Jolt/Physics/Collision/CollectFacesMode.h>
#include <Jolt/Physics/Collision/CollideShape.h>
#include <Jolt/Physics/Collision/Shape/BoxShape.h>
#include <Jolt/Physics/Collision/Shape/SphereShape.h>
#include <Jolt/Physics/PhysicsSettings.h>
#include <Jolt/Physics/PhysicsSystem.h>
#include <Jolt/RegisterTypes.h>

template<typename E>
constexpr auto to_integral(E e) -> typename std::underlying_type<E>::type 
{
    return static_cast<typename std::underlying_type<E>::type>(e);
}

#define ENSURE_TESTS

// Ensures that a constant value defined in JoltC doesn't drift out of sync with
// its Jolt Physics C++ counterpart.
#define ENSURE_EQUAL(c_const, cpp_const) \
    static_assert(c_const == cpp_const, #c_const " did not match " #cpp_const); \
    static_assert(std::is_same_v<decltype(c_const), decltype(cpp_const)>, "type of " #c_const " did not match type of " #cpp_const);

// Ensures that a C constant that represents an enum value matches the integral
// value of a C++ enum.
#define ENSURE_ENUM_EQ(c_const, cpp_enum) \
    static_assert(c_const == to_integral(cpp_enum), #c_const " did not match " #cpp_enum); \
    static_assert(sizeof(c_const) == sizeof(cpp_enum), #c_const " did not have same size as " #cpp_enum);

// Ensures that a C struct we define is compatible in layout with its
// corresponding C++ type, and that the C++ type is safe to represent in C.
#define ENSURE_SIZE_ALIGN(c_type, cpp_type) \
    static_assert(sizeof(c_type) == sizeof(cpp_type), "size of " #c_type " did not match size of " #cpp_type); \
    static_assert(alignof(c_type) == alignof(cpp_type), "align of " #c_type " did not match align of " #cpp_type); \
    static_assert(!std::is_polymorphic_v<cpp_type>, #cpp_type " is polymorphic and cannot be mirrored");

// Internal macro to get the type of a struct field by name.
#define unsafe_fieldtype(st, m) decltype(((st *)(0))->m)

// Ensures that the field offset, size, and alignment of two fields from two
// different structs are identical.
//
// Comparing the offsets and alignments of each field helps provide some guarantee that
#define ENSURE_FIELD(type0, field0, type1, field1) \
    static_assert(offsetof(type0, field0) == offsetof(type1, field1), \
        #type0 "." #field0 " did not have same offset as " #type1 "." #field1); \
    ENSURE_SIZE_ALIGN(unsafe_fieldtype(type0, field0), unsafe_fieldtype(type1, field1)) \

// Just like ENSURE_FIELD, but follows the normal conventions of both JoltC and
// Jolt Physics to reduce boilerplate.
//
// JoltC's types begin with JPC_ while Jolt's types are in the JPH namespace.
// Jolt prefixes public members with 'm' but JoltC strips that name away.
#define ENSURE_NORMAL_FIELD(basetype, basefield) \
    ENSURE_FIELD(JPC_ ## basetype, basefield, JPH:: ## basetype, m ## basefield);

#include "JoltC/JoltC.h"