内部関数呼び出し

Module2.bas

Option Explicit

Private Declare PtrSafe Function GetModuleHandle Lib "kernel32" Alias "GetModuleHandleA" (ByVal lpModuleName As String) As LongPtr
Private Declare PtrSafe Function GetProcAddress Lib "kernel32" (ByVal hModule As LongPtr, ByVal lpProcName As String) As LongPtr
Private Declare PtrSafe _
Function DispCallFunc Lib "OleAut32.dll" ( _
    ByVal pvInstance As LongPtr, _
    ByVal oVft As LongPtr, _
    ByVal cc_ As Long, _
    ByVal vtReturn As Integer, _
    ByVal cActuals As Long, _
    ByRef prgvt As Integer, _
    ByRef prgpvarg As LongPtr, _
    ByRef pvargResult As Variant _
    ) As Long
Const CC_CDECL = 1


Sub hoge()

    Dim proc As LongPtr
    proc = GetModuleHandle("vbe7.dll")
    If proc = 0 Then Exit Sub
    Debug.Print Hex$(proc)
    
    'void *__cdecl memcpy(void *Dst, const void *Src, size_t Size);
    proc = proc + &H13B3
    Debug.Print Hex$(proc)

    Dim hr As Long
    Dim ret As Variant
    Dim pObj As LongPtr
    pObj = ObjPtr(Application)
    Dim pVtbl As LongPtr

    Dim pVar(0 To 2) As LongPtr
    Dim v(0 To 2) As Variant
    
    v(0) = VarPtr(pVtbl)
    v(1) = (pObj)
    v(2) = 4&
    
    pVar(0) = VarPtr(v(0))
    pVar(1) = VarPtr(v(1))
    pVar(2) = VarPtr(v(2))
    
    Dim vt(0 To 2) As Integer
    vt(0) = vbLong
    vt(1) = vbLong
    vt(2) = vbLong
    
    hr = DispCallFunc(0, proc, CC_CDECL, vbLong, 3, vt(0), pVar(0), ret)
    Debug.Print Hex$(hr), Hex$(ret)

End Sub

Hi,

Can you explain what this code does ? Thank you.