Cleanup QTypeInfo

Remove QTypeInfo::isStatic, as that's not used anymore in Qt 6.
Also remove sizeOf, it's unused, and we have QMetaType for that if
required.
Remove all typeinfo declaractions for trivial types, as the default
template covers them correctly nowadays.

Finally set up a better default for isPointer, and do some smaller
cleanups all over the place.

Change-Id: I6758ed37dfc701feaaf0ff105cc95e32da9f9c33
Reviewed-by: Fabian Kosmale <fabian.kosmale@qt.io>
Reviewed-by: Thiago Macieira <thiago.macieira@intel.com>

6 files changed, 21 insertions, 134 deletions

diff --git a/src/corelib/global/qtypeinfo.h b/src/corelib/global/qtypeinfo.h
index e45347ee10..30db5c4487 100644
--- a/src/corelib/global/qtypeinfo.h
+++ b/src/corelib/global/qtypeinfo.h
@@ -55,16 +55,7 @@ class QDebug;
 */
 
 template <typename T>
-static constexpr bool qIsRelocatable()
-{
-    return std::is_trivially_copyable<T>::value && std::is_trivially_destructible<T>::value;
-}
-
-template <typename T>
-static constexpr bool qIsTrivial()
-{
-    return std::is_trivial<T>::value;
-}
+static constexpr bool qIsRelocatable =  std::is_trivially_copyable_v<T> && std::is_trivially_destructible_v<T>;
 
 /*
   The catch-all template.
@@ -75,12 +66,10 @@ class QTypeInfo
 {
 public:
     enum {
-        isPointer = false,
-        isIntegral = std::is_integral<T>::value,
-        isComplex = !qIsTrivial<T>(),
-        isStatic = true,
-        isRelocatable = qIsRelocatable<T>(),
-        sizeOf = sizeof(T)
+        isPointer = std::is_pointer_v<T>,
+        isIntegral = std::is_integral_v<T>,
+        isComplex = !std::is_trivial_v<T>,
+        isRelocatable = qIsRelocatable<T>,
     };
 };
 
@@ -92,53 +81,11 @@ public:
         isPointer = false,
         isIntegral = false,
         isComplex = false,
-        isStatic = false,
         isRelocatable = false,
-        sizeOf = 0
-    };
-};
-
-template <typename T>
-class QTypeInfo<T*>
-{
-public:
-    enum {
-        isPointer = true,
-        isIntegral = false,
-        isComplex = false,
-        isStatic = false,
-        isRelocatable = true,
-        sizeOf = sizeof(T*)
     };
 };
 
 /*!
-    \class QTypeInfoQuery
-    \inmodule QtCore
-    \internal
-    \brief QTypeInfoQuery is used to query the values of a given QTypeInfo<T>
-
-    We use it because there may be some QTypeInfo<T> specializations in user
-    code that don't provide certain flags that we added after Qt 5.0. They are:
-    \list
-      \li isRelocatable: defaults to !isStatic
-    \endlist
-
-    DO NOT specialize this class elsewhere.
-*/
-// apply defaults for a generic QTypeInfo<T> that didn't provide the new values
-template <typename T, typename = void>
-struct QTypeInfoQuery : public QTypeInfo<T>
-{
-    enum { isRelocatable = !QTypeInfo<T>::isStatic };
-};
-
-// if QTypeInfo<T>::isRelocatable exists, use it
-template <typename T>
-struct QTypeInfoQuery<T, typename std::enable_if<QTypeInfo<T>::isRelocatable || true>::type> : public QTypeInfo<T>
-{};
-
-/*!
     \class QTypeInfoMerger
     \inmodule QtCore
     \internal
@@ -163,12 +110,10 @@ class QTypeInfoMerger
 {
     static_assert(sizeof...(Ts) > 0);
 public:
-    static constexpr bool isComplex = ((QTypeInfoQuery<Ts>::isComplex) || ...);
-    static constexpr bool isStatic =  ((QTypeInfoQuery<Ts>::isStatic) || ...);
-    static constexpr bool isRelocatable = ((QTypeInfoQuery<Ts>::isRelocatable) && ...);
+    static constexpr bool isComplex = ((QTypeInfo<Ts>::isComplex) || ...);
+    static constexpr bool isRelocatable = ((QTypeInfo<Ts>::isRelocatable) && ...);
     static constexpr bool isPointer = false;
     static constexpr bool isIntegral = false;
-    static constexpr std::size_t sizeOf = sizeof(T);
 };
 
 #define Q_DECLARE_MOVABLE_CONTAINER(CONTAINER) \
@@ -182,8 +127,6 @@ public: \
         isIntegral = false, \
         isComplex = true, \
         isRelocatable = true, \
-        isStatic = false, \
-        sizeOf = sizeof(CONTAINER<T>) \
     }; \
 }
 
@@ -204,9 +147,7 @@ public: \
         isPointer = false, \
         isIntegral = false, \
         isComplex = true, \
-        isStatic = false, \
         isRelocatable = true, \
-        sizeOf = sizeof(CONTAINER<K, V>) \
     }; \
 }
 
@@ -228,10 +169,9 @@ Q_DECLARE_MOVABLE_CONTAINER(QMultiHash);
 enum { /* TYPEINFO flags */
     Q_COMPLEX_TYPE = 0,
     Q_PRIMITIVE_TYPE = 0x1,
-    Q_STATIC_TYPE = 0,
-    Q_MOVABLE_TYPE = 0x2,               // ### Qt6: merge movable and relocatable once QList no longer depends on it
+    Q_RELOCATABLE_TYPE = 0x2,
+    Q_MOVABLE_TYPE = 0x2,
     Q_DUMMY_TYPE = 0x4,
-    Q_RELOCATABLE_TYPE = 0x8
 };
 
 #define Q_DECLARE_TYPEINFO_BODY(TYPE, FLAGS) \
@@ -239,14 +179,11 @@ class QTypeInfo<TYPE > \
 { \
 public: \
     enum { \
-        isComplex = (((FLAGS) & Q_PRIMITIVE_TYPE) == 0) && !qIsTrivial<TYPE>(), \
-        isStatic = (((FLAGS) & (Q_MOVABLE_TYPE | Q_PRIMITIVE_TYPE)) == 0), \
-        isRelocatable = !isStatic || ((FLAGS) & Q_RELOCATABLE_TYPE) || qIsRelocatable<TYPE>(), \
+        isComplex = (((FLAGS) & Q_PRIMITIVE_TYPE) == 0) && !std::is_trivial_v<TYPE>, \
+        isRelocatable = !isComplex || ((FLAGS) & Q_RELOCATABLE_TYPE) || qIsRelocatable<TYPE>, \
         isPointer = false, \
         isIntegral = std::is_integral< TYPE >::value, \
-        sizeOf = sizeof(TYPE) \
     }; \
-    static inline const char *name() { return #TYPE; } \
 }
 
 #define Q_DECLARE_TYPEINFO(TYPE, FLAGS) \
@@ -283,50 +220,6 @@ inline void swap(TYPE &value1, TYPE &value2) \
 #define Q_DECLARE_SHARED_NOT_MOVABLE_UNTIL_QT6(TYPE) \
                                Q_DECLARE_SHARED_IMPL(TYPE, QT_VERSION >= QT_VERSION_CHECK(6,0,0) ? Q_MOVABLE_TYPE : Q_RELOCATABLE_TYPE)
 
-/*
-   QTypeInfo primitive specializations
-*/
-Q_DECLARE_TYPEINFO(bool, Q_PRIMITIVE_TYPE);
-Q_DECLARE_TYPEINFO(char, Q_PRIMITIVE_TYPE);
-Q_DECLARE_TYPEINFO(signed char, Q_PRIMITIVE_TYPE);
-Q_DECLARE_TYPEINFO(uchar, Q_PRIMITIVE_TYPE);
-Q_DECLARE_TYPEINFO(short, Q_PRIMITIVE_TYPE);
-Q_DECLARE_TYPEINFO(ushort, Q_PRIMITIVE_TYPE);
-Q_DECLARE_TYPEINFO(int, Q_PRIMITIVE_TYPE);
-Q_DECLARE_TYPEINFO(uint, Q_PRIMITIVE_TYPE);
-Q_DECLARE_TYPEINFO(long, Q_PRIMITIVE_TYPE);
-Q_DECLARE_TYPEINFO(ulong, Q_PRIMITIVE_TYPE);
-Q_DECLARE_TYPEINFO(qint64, Q_PRIMITIVE_TYPE);
-Q_DECLARE_TYPEINFO(quint64, Q_PRIMITIVE_TYPE);
-Q_DECLARE_TYPEINFO(float, Q_PRIMITIVE_TYPE);
-Q_DECLARE_TYPEINFO(double, Q_PRIMITIVE_TYPE);
-
-#if QT_VERSION >= QT_VERSION_CHECK(6,0,0)
-// ### Qt 6: remove the other branch
-// This was required so that QList<T> for these types allocates out of the array storage
-Q_DECLARE_TYPEINFO(long double, Q_PRIMITIVE_TYPE);
-#  ifdef Q_COMPILER_UNICODE_STRINGS
-Q_DECLARE_TYPEINFO(char16_t, Q_PRIMITIVE_TYPE);
-Q_DECLARE_TYPEINFO(char32_t, Q_PRIMITIVE_TYPE);
-#  endif
-#  if !defined(Q_CC_MSVC) || defined(_NATIVE_WCHAR_T_DEFINED)
-Q_DECLARE_TYPEINFO(wchar_t, Q_PRIMITIVE_TYPE);
-#  endif
-#else
-#  ifndef Q_OS_DARWIN
-Q_DECLARE_TYPEINFO(long double, Q_PRIMITIVE_TYPE);
-#  else
-Q_DECLARE_TYPEINFO(long double, Q_RELOCATABLE_TYPE);
-#  endif
-#  ifdef Q_COMPILER_UNICODE_STRINGS
-Q_DECLARE_TYPEINFO(char16_t, Q_RELOCATABLE_TYPE);
-Q_DECLARE_TYPEINFO(char32_t, Q_RELOCATABLE_TYPE);
-#  endif
-#  if !defined(Q_CC_MSVC) || defined(_NATIVE_WCHAR_T_DEFINED)
-Q_DECLARE_TYPEINFO(wchar_t, Q_RELOCATABLE_TYPE);
-#  endif
-#endif // Qt 6
-
 namespace QTypeTraits
 {
 
diff --git a/src/corelib/kernel/qmetatype.h b/src/corelib/kernel/qmetatype.h
index bf76f39a2a..cfc5f06c90 100644
--- a/src/corelib/kernel/qmetatype.h
+++ b/src/corelib/kernel/qmetatype.h
@@ -1459,7 +1459,7 @@ namespace QtPrivate {
     template<typename T>
     struct QMetaTypeTypeFlags
     {
-        enum { Flags = (QTypeInfoQuery<T>::isRelocatable ? QMetaType::MovableType : 0)
+        enum { Flags = (QTypeInfo<T>::isRelocatable ? QMetaType::MovableType : 0)
                      | (QTypeInfo<T>::isComplex ? QMetaType::NeedsConstruction : 0)
                      | (QTypeInfo<T>::isComplex ? QMetaType::NeedsDestruction : 0)
                      | (IsPointerToTypeDerivedFromQObject<T>::Value ? QMetaType::PointerToQObject : 0)
diff --git a/src/corelib/tools/qarraydataops.h b/src/corelib/tools/qarraydataops.h
index f787dacfac..f6384ca998 100644
--- a/src/corelib/tools/qarraydataops.h
+++ b/src/corelib/tools/qarraydataops.h
@@ -174,7 +174,7 @@ struct QArrayExceptionSafetyPrimitives
         T *const end;
         qsizetype displace;
 
-        static_assert(QTypeInfoQuery<T>::isRelocatable, "Type must be relocatable");
+        static_assert(QTypeInfo<T>::isRelocatable, "Type must be relocatable");
 
         Displacer(T *start, T *finish, qsizetype diff) noexcept
             : begin(start), end(finish), displace(diff)
@@ -201,7 +201,7 @@ struct QArrayExceptionSafetyPrimitives
         size_t n;
         qsizetype &size;
 
-        static_assert(QTypeInfoQuery<T>::isRelocatable, "Type must be relocatable");
+        static_assert(QTypeInfo<T>::isRelocatable, "Type must be relocatable");
 
         Mover(T *&start, size_t length, qsizetype &sz) noexcept
             : destination(start), source(start), n(length), size(sz)
@@ -1018,7 +1018,7 @@ struct QArrayOpsSelector
 template <class T>
 struct QArrayOpsSelector<T,
     typename std::enable_if<
-        !QTypeInfoQuery<T>::isComplex && QTypeInfoQuery<T>::isRelocatable
+        !QTypeInfo<T>::isComplex && QTypeInfo<T>::isRelocatable
     >::type>
 {
     typedef QPodArrayOps<T> Type;
@@ -1027,7 +1027,7 @@ struct QArrayOpsSelector<T,
 template <class T>
 struct QArrayOpsSelector<T,
     typename std::enable_if<
-        QTypeInfoQuery<T>::isComplex && QTypeInfoQuery<T>::isRelocatable
+        QTypeInfo<T>::isComplex && QTypeInfo<T>::isRelocatable
     >::type>
 {
     typedef QMovableArrayOps<T> Type;
diff --git a/src/corelib/tools/qcontainertools_impl.h b/src/corelib/tools/qcontainertools_impl.h
index 44cfdc444e..a7e1aa31cd 100644
--- a/src/corelib/tools/qcontainertools_impl.h
+++ b/src/corelib/tools/qcontainertools_impl.h
@@ -61,7 +61,7 @@ namespace QtPrivate
 template <typename T, typename N>
 void q_uninitialized_relocate_n(T* first, N n, T* out)
 {
-    if constexpr (QTypeInfoQuery<T>::isRelocatable) {
+    if constexpr (QTypeInfo<T>::isRelocatable) {
         if (n != N(0)) { // even if N == 0, out == nullptr or first == nullptr are UB for memmove()
             std::memmove(static_cast<void*>(out),
                          static_cast<const void*>(first),
@@ -69,7 +69,7 @@ void q_uninitialized_relocate_n(T* first, N n, T* out)
         }
     } else {
         std::uninitialized_move_n(first, n, out);
-        if constexpr (QTypeInfoQuery<T>::isComplex)
+        if constexpr (QTypeInfo<T>::isComplex)
             std::destroy_n(first, n);
     }
 }
diff --git a/src/corelib/tools/qvarlengtharray.h b/src/corelib/tools/qvarlengtharray.h
index a70fc75fcf..01571e3e9f 100644
--- a/src/corelib/tools/qvarlengtharray.h
+++ b/src/corelib/tools/qvarlengtharray.h
@@ -429,7 +429,7 @@ Q_OUTOFLINE_TEMPLATE void QVarLengthArray<T, Prealloc>::realloc(qsizetype asize,
             a = Prealloc;
         }
         s = 0;
-        if (!QTypeInfoQuery<T>::isRelocatable) {
+        if (!QTypeInfo<T>::isRelocatable) {
             QT_TRY {
                 // move all the old elements
                 while (s < copySize) {
@@ -556,7 +556,7 @@ Q_OUTOFLINE_TEMPLATE typename QVarLengthArray<T, Prealloc>::iterator QVarLengthA
     if (n != 0) {
         resize(s + n);
         const T copy(t);
-        if (!QTypeInfoQuery<T>::isRelocatable) {
+        if (!QTypeInfo<T>::isRelocatable) {
             T *b = ptr + offset;
             T *j = ptr + s;
             T *i = j - n;
diff --git a/src/gui/math3d/qgenericmatrix.h b/src/gui/math3d/qgenericmatrix.h
index 81fc9eee62..1381014a04 100644
--- a/src/gui/math3d/qgenericmatrix.h
+++ b/src/gui/math3d/qgenericmatrix.h
@@ -108,12 +108,6 @@ template <int N, int M, typename T>
 class QTypeInfo<QGenericMatrix<N, M, T> >
     : public QTypeInfoMerger<QGenericMatrix<N, M, T>, T>
 {
-#if QT_VERSION < QT_VERSION_CHECK(6,0,0)
-public:
-    enum {
-        isStatic = true,
-    }; // at least Q_RELOCATABLE_TYPE, for BC during Qt 5
-#endif
 };
 
 template <int N, int M, typename T>
@@ -350,7 +344,7 @@ QDebug operator<<(QDebug dbg, const QGenericMatrix<N, M, T> &m)
 {
     QDebugStateSaver saver(dbg);
     dbg.nospace() << "QGenericMatrix<" << N << ", " << M
-        << ", " << QTypeInfo<T>::name()
+        << ", " << QMetaType::fromType<T>().name()
         << ">(" << Qt::endl << qSetFieldWidth(10);
     for (int row = 0; row < M; ++row) {
         for (int col = 0; col < N; ++col)