util: make offsetof/parent-of-member actually constexpr

libraries/libstratosphere/source/cfg/cfg_override.cpp

@@ -84,6 +84,8 @@ namespace ams::cfg {
             .override_any_app = true,
         };
 
+        bool g_loaded_override_config = false;
+
         char g_hbl_sd_path[0x100] = "/atmosphere/hbl.nsp";
 
         /* Helpers. */

libraries/libvapours/include/vapours/defines.hpp

@@ -34,6 +34,7 @@
 #define ALIGNED(algn) __attribute__((aligned(algn)))
 #define NORETURN      __attribute__((noreturn))
 #define WEAK_SYMBOL   __attribute__((weak))
+#define ALWAYS_INLINE_LAMBDA __attribute__((always_inline))
 #define ALWAYS_INLINE inline __attribute__((always_inline))
 #define NOINLINE      __attribute__((noinline))
 

libraries/libvapours/include/vapours/util/util_intrusive_list.hpp

@@ -557,11 +557,11 @@ namespace ams::util {
             }
 
             static constexpr Derived &GetParent(IntrusiveListNode &node) {
-                return static_cast<Derived &>(util::GetParentReference<Member>(&node));
+                return util::GetParentReference<Member, Derived>(&node);
             }
 
             static constexpr Derived const &GetParent(IntrusiveListNode const &node) {
-                return static_cast<const Derived &>(util::GetParentReference<Member>(&node));
+                return util::GetParentReference<Member, Derived>(&node);
             }
     };
 

libraries/libvapours/include/vapours/util/util_intrusive_red_black_tree.hpp

@@ -257,11 +257,11 @@ namespace ams::util {
             }
 
             static constexpr Derived *GetParent(IntrusiveRedBlackTreeNode *node) {
-                return static_cast<Derived *>(util::GetParentPointer<Member>(node));
+                return util::GetParentPointer<Member, Derived>(node);
             }
 
             static constexpr Derived const *GetParent(IntrusiveRedBlackTreeNode const *node) {
-                return static_cast<const Derived *>(util::GetParentPointer<Member>(node));
+                return util::GetParentPointer<Member, Derived>(node);
             }
     };
 

libraries/libvapours/include/vapours/util/util_parent_of_member.hpp

@@ -21,22 +21,81 @@ namespace ams::util {
 
     namespace impl {
 
-        template<typename Parent, typename Member>
+        template<size_t Alignment>
-        union OffsetOfImpl {
+        struct OffsetOfUnionHolder {
-            Member Parent::* ptr;
+            template<typename ParentType, typename MemberType, size_t Offset>
-            intptr_t offset;
+            union UnionImpl {
+                static constexpr size_t GetOffset() { return Offset; }
+
+                struct {
+                    char padding[Offset];
+                    MemberType members[(sizeof(ParentType) / sizeof(MemberType)) + 1];
+                } data;
+                UnionImpl<ParentType, MemberType, Offset + 1> next_union;
             };
 
-        template<typename Parent, typename Member>
+            template<typename ParentType, typename MemberType>
-        constexpr inline Parent *GetParentOfMemberImpl(Member *member, Member Parent::* ptr) {
+            union UnionImpl<ParentType, MemberType, 0> {
-            return reinterpret_cast<Parent *>(reinterpret_cast<uintptr_t>(member) - OffsetOfImpl<Parent, Member>{ ptr }.offset);
+                static constexpr size_t GetOffset() { return 0; }
+
+                struct {
+                    MemberType members[(sizeof(ParentType) / sizeof(MemberType)) + 1];
+                } data;
+                UnionImpl<ParentType, MemberType, 1> next_union;
+            };
+
+            template<typename ParentType, typename MemberType>
+            union UnionImpl<ParentType, MemberType, Alignment> { /* Empty */ };
+        };
+
+        template<typename ParentType, typename MemberType>
+        struct OffsetOfCalculator {
+            using UnionHolder = typename OffsetOfUnionHolder<alignof(MemberType)>::template UnionImpl<ParentType, MemberType, 0>;
+            union Union {
+                char c;
+                UnionHolder first_union;
+                ParentType parent;
+
+                /* This coerces the active member to be c. */
+                constexpr Union() : c() { /* ... */ }
+            };
+            static constexpr Union U = {};
+
+            static constexpr const MemberType *GetNextAddress(const MemberType *start, const MemberType *target) {
+                while (start < target) {
+                    start++;
+                }
+                return start;
             }
 
-        template<typename Parent, typename Member>
+            static constexpr std::ptrdiff_t GetDifference(const MemberType *start, const MemberType *target) {
-        constexpr inline Parent const *GetParentOfMemberImpl(Member const *member, Member Parent::* ptr) {
+                return (target - start) * sizeof(MemberType);
-            return reinterpret_cast<Parent *>(reinterpret_cast<uintptr_t>(member) - OffsetOfImpl<Parent, Member>{ ptr }.offset);
             }
 
+            template<typename CurUnion>
+            static constexpr std::ptrdiff_t OffsetOfImpl(MemberType ParentType::*member, CurUnion &cur_union) {
+                constexpr size_t Offset = CurUnion::GetOffset();
+                const auto target = std::addressof(U.parent.*member);
+                const auto start  = std::addressof(cur_union.data.members[0]);
+                const auto next   = GetNextAddress(start, target);
+
+                if (next < target) {
+                    if constexpr (Offset + 1 < alignof(MemberType)) {
+                        return OffsetOfImpl(member, cur_union.next_union);
+                    } else {
+                        static_assert(Offset + 1 <= alignof(MemberType));
+                    }
+                }
+
+                return (next - start) * sizeof(MemberType) + Offset;
+            }
+
+
+            static constexpr std::ptrdiff_t OffsetOf(MemberType ParentType::*member) {
+                return OffsetOfImpl(member, U.first_union);
+            }
+        };
+
         template<typename T>
         struct GetMemberPointerTraits;
 
@@ -52,26 +111,140 @@ namespace ams::util {
         template<auto MemberPtr>
         using GetMemberType = typename GetMemberPointerTraits<decltype(MemberPtr)>::Member;
 
+        template<auto MemberPtr, typename RealParentType = GetParentType<MemberPtr>>
+        constexpr inline std::ptrdiff_t OffsetOf = [] {
+            using DeducedParentType = GetParentType<MemberPtr>;
+            using MemberType        = GetMemberType<MemberPtr>;
+            static_assert(std::is_base_of<DeducedParentType, RealParentType>::value || std::is_same<RealParentType, DeducedParentType>::value);
+
+            return OffsetOfCalculator<RealParentType, MemberType>::OffsetOf(MemberPtr);
+        }();
+
     }
 
-    template<auto MemberPtr>
+    template<auto MemberPtr, typename RealParentType = impl::GetParentType<MemberPtr>>
-    constexpr inline impl::GetParentType<MemberPtr> *GetParentPointer(impl::GetMemberType<MemberPtr> *member) {
+    constexpr ALWAYS_INLINE RealParentType &GetParentReference(impl::GetMemberType<MemberPtr> *member) {
-        return impl::GetParentOfMemberImpl<impl::GetParentType<MemberPtr>, impl::GetMemberType<MemberPtr>>(member, MemberPtr);
+        constexpr std::ptrdiff_t Offset = impl::OffsetOf<MemberPtr, RealParentType>;
+        uint8_t *addr = static_cast<uint8_t *>(static_cast<void *>(member));
+        addr -= Offset;
+        return *static_cast<RealParentType *>(static_cast<void *>(addr));
     }
 
-    template<auto MemberPtr>
+    template<auto MemberPtr, typename RealParentType = impl::GetParentType<MemberPtr>>
-    constexpr inline impl::GetParentType<MemberPtr> const *GetParentPointer(impl::GetMemberType<MemberPtr> const *member) {
+    constexpr ALWAYS_INLINE RealParentType const &GetParentReference(impl::GetMemberType<MemberPtr> const *member) {
-        return impl::GetParentOfMemberImpl<impl::GetParentType<MemberPtr>, impl::GetMemberType<MemberPtr>>(member, MemberPtr);
+        constexpr std::ptrdiff_t Offset = impl::OffsetOf<MemberPtr, RealParentType>;
+        const uint8_t *addr = static_cast<const uint8_t *>(static_cast<const void *>(member));
+        addr -= Offset;
+        return *static_cast<const RealParentType *>(static_cast<const void *>(addr));
     }
 
-    template<auto MemberPtr>
+    template<auto MemberPtr, typename RealParentType = impl::GetParentType<MemberPtr>>
-    constexpr inline impl::GetParentType<MemberPtr> &GetParentReference(impl::GetMemberType<MemberPtr> *member) {
+    constexpr ALWAYS_INLINE RealParentType *GetParentPointer(impl::GetMemberType<MemberPtr> *member) {
-        return *impl::GetParentOfMemberImpl<impl::GetParentType<MemberPtr>, impl::GetMemberType<MemberPtr>>(member, MemberPtr);
+        return std::addressof(GetParentReference<MemberPtr, RealParentType>(member));
     }
 
-    template<auto MemberPtr>
+    template<auto MemberPtr, typename RealParentType = impl::GetParentType<MemberPtr>>
-    constexpr inline impl::GetParentType<MemberPtr> const &GetParentReference(impl::GetMemberType<MemberPtr> const *member) {
+    constexpr ALWAYS_INLINE RealParentType const *GetParentPointer(impl::GetMemberType<MemberPtr> const *member) {
-        return *impl::GetParentOfMemberImpl<impl::GetParentType<MemberPtr>, impl::GetMemberType<MemberPtr>>(member, MemberPtr);
+        return std::addressof(GetParentReference<MemberPtr, RealParentType>(member));
+    }
+
+    namespace test {
+
+        struct Struct1 {
+            uint32_t a;
+        };
+
+        struct Struct2 {
+            uint32_t b;
+        };
+
+        struct Struct3 : public Struct1, Struct2 {
+            uint32_t c;
+        };
+
+        static_assert(impl::OffsetOf<&Struct1::a> == 0);
+        static_assert(impl::OffsetOf<&Struct2::b> == 0);
+        static_assert(impl::OffsetOf<&Struct3::a> == 0);
+        static_assert(impl::OffsetOf<&Struct3::b> == 0);
+
+
+        static_assert(impl::OffsetOf<&Struct3::a, Struct3> == 0 || impl::OffsetOf<&Struct3::b, Struct3> == 0);
+        static_assert(impl::OffsetOf<&Struct3::a, Struct3> == sizeof(Struct2) || impl::OffsetOf<&Struct3::b, Struct3> == sizeof(Struct1));
+        static_assert(impl::OffsetOf<&Struct3::c> == sizeof(Struct1) + sizeof(Struct2));
+
+        constexpr Struct3 TestStruct3 = {};
+
+        static_assert(std::addressof(TestStruct3) == GetParentPointer<&Struct3::a, Struct3>(std::addressof(TestStruct3.a)));
+        static_assert(std::addressof(TestStruct3) == GetParentPointer<&Struct3::b, Struct3>(std::addressof(TestStruct3.b)));
+        static_assert(std::addressof(TestStruct3) == GetParentPointer<&Struct3::c, Struct3>(std::addressof(TestStruct3.c)));
+
+        struct CharArray {
+            char c0;
+            char c1;
+            char c2;
+            char c3;
+            char c4;
+            char c5;
+            char c6;
+            char c7;
+        };
+
+        static_assert(impl::OffsetOf<&CharArray::c0> == 0);
+        static_assert(impl::OffsetOf<&CharArray::c1> == 1);
+        static_assert(impl::OffsetOf<&CharArray::c2> == 2);
+        static_assert(impl::OffsetOf<&CharArray::c3> == 3);
+        static_assert(impl::OffsetOf<&CharArray::c4> == 4);
+        static_assert(impl::OffsetOf<&CharArray::c5> == 5);
+        static_assert(impl::OffsetOf<&CharArray::c6> == 6);
+        static_assert(impl::OffsetOf<&CharArray::c7> == 7);
+
+        constexpr CharArray TestCharArray = {};
+
+        static_assert(std::addressof(TestCharArray) == GetParentPointer<&CharArray::c0>(std::addressof(TestCharArray.c0)));
+        static_assert(std::addressof(TestCharArray) == GetParentPointer<&CharArray::c1>(std::addressof(TestCharArray.c1)));
+        static_assert(std::addressof(TestCharArray) == GetParentPointer<&CharArray::c2>(std::addressof(TestCharArray.c2)));
+        static_assert(std::addressof(TestCharArray) == GetParentPointer<&CharArray::c3>(std::addressof(TestCharArray.c3)));
+        static_assert(std::addressof(TestCharArray) == GetParentPointer<&CharArray::c4>(std::addressof(TestCharArray.c4)));
+        static_assert(std::addressof(TestCharArray) == GetParentPointer<&CharArray::c5>(std::addressof(TestCharArray.c5)));
+        static_assert(std::addressof(TestCharArray) == GetParentPointer<&CharArray::c6>(std::addressof(TestCharArray.c6)));
+        static_assert(std::addressof(TestCharArray) == GetParentPointer<&CharArray::c7>(std::addressof(TestCharArray.c7)));
+
     }
 
 }
+
+/* Defines, for use by other code. */
+
+#define OFFSETOF(parent, member) (::ams::util::OffsetOf<&parent::member, parent>)
+
+#define AMS_GET_PARENT_TYPE_IMPL(parent, argt) typename std::conditional<std::is_pointer<argt>::value,                                                          \
+                                                                    typename std::conditional<std::is_const<typename std::remove_pointer<argt>::type>::value,   \
+                                                                                              const parent,                                                     \
+                                                                                              parent                                                            \
+                                                                                             >::type,                                                           \
+                                                                    typename std::conditional<std::is_const<typename std::remove_reference<argt>::type>::value, \
+                                                                                              const parent,                                                     \
+                                                                                              parent                                                            \
+                                                                                             >::type                                                            \
+                                                                    >::type
+
+#define GET_PARENT_PTR(parent, member, _arg) ([]<typename GetParentPtrArgType>(GetParentPtrArgType &arg) ALWAYS_INLINE_LAMBDA -> AMS_GET_PARENT_TYPE_IMPL(parent, GetParentPtrArgType) * {     \
+    using ParentPtrType = typename std::conditional<std::is_const<GetParentPtrArgType>::value, const parent, parent>::type *;                                                                  \
+    if constexpr (std::is_pointer<GetParentPtrArgType>::value) {                                                                                                                               \
+        static_assert(std::is_same<typename std::remove_cv<decltype(parent::member)>::type, typename std::remove_cv<typename std::remove_pointer<GetParentPtrArgType>::type>::type>::value);   \
+        return ::ams::util::GetParentPointer<&parent::member, parent>(arg);                                                                                                                    \
+    } else {                                                                                                                                                                                   \
+        static_assert(std::is_same<typename std::remove_cv<decltype(parent::member)>::type, typename std::remove_cv<typename std::remove_reference<GetParentPtrArgType>::type>::type>::value); \
+        return ::ams::util::GetParentPointer<&parent::member, parent>(std::addressof(arg));                                                                                                    \
+    }                                                                                                                                                                                          \
+}(_arg))
+
+#define GET_PARENT_REF(parent, member, _arg) ([]<typename GetParentPtrArgType>(GetParentPtrArgType &arg) ALWAYS_INLINE_LAMBDA -> AMS_GET_PARENT_TYPE_IMPL(parent, GetParentPtrArgType) & {     \
+    if constexpr (std::is_pointer<GetParentPtrArgType>::value) {                                                                                                                               \
+        static_assert(std::is_same<typename std::remove_cv<decltype(parent::member)>::type, typename std::remove_cv<typename std::remove_pointer<GetParentPtrArgType>::type>::type>::value);   \
+        return ::ams::util::GetParentReference<&parent::member, parent>(arg);                                                                                                                  \
+    } else {                                                                                                                                                                                   \
+        static_assert(std::is_same<typename std::remove_cv<decltype(parent::member)>::type, typename std::remove_cv<typename std::remove_reference<GetParentPtrArgType>::type>::type>::value); \
+        return ::ams::util::GetParentReference<&parent::member, parent>(std::addressof(arg));                                                                                                  \
+    }                                                                                                                                                                                          \
+}(_arg))

libraries/libvapours/include/vapours/util/util_scope_guard.hpp

@@ -29,24 +29,24 @@ namespace ams::util {
                 F f;
                 bool active;
             public:
-                constexpr ScopeGuard(F f) : f(std::move(f)), active(true) { }
+                constexpr ALWAYS_INLINE ScopeGuard(F f) : f(std::move(f)), active(true) { }
-                ~ScopeGuard() { if (active) { f(); } }
+                ALWAYS_INLINE ~ScopeGuard() { if (active) { f(); } }
-                void Cancel() { active = false; }
+                ALWAYS_INLINE void Cancel() { active = false; }
 
-                ScopeGuard(ScopeGuard&& rhs) : f(std::move(rhs.f)), active(rhs.active) {
+                ALWAYS_INLINE ScopeGuard(ScopeGuard&& rhs) : f(std::move(rhs.f)), active(rhs.active) {
                     rhs.Cancel();
                 }
         };
 
         template<class F>
-        constexpr ScopeGuard<F> MakeScopeGuard(F f) {
+        constexpr ALWAYS_INLINE ScopeGuard<F> MakeScopeGuard(F f) {
             return ScopeGuard<F>(std::move(f));
         }
 
         enum class ScopeGuardOnExit {};
 
         template <typename F>
-        constexpr ScopeGuard<F> operator+(ScopeGuardOnExit, F&& f) {
+        constexpr ALWAYS_INLINE ScopeGuard<F> operator+(ScopeGuardOnExit, F&& f) {
             return ScopeGuard<F>(std::forward<F>(f));
         }