Re: Importing calls to access Windows registry

[tmoran@bix.com (Tom Moran)]

The immediate answer to your link errors, as pointed out by
Sune Falck, is to add advapi32.lib to your link.

As a comment, I'd also suggest you can save yourself a lot of
typing and probably a lot of grief by using the package
Interfaces.C, instead of defining your own "windows_integer_type"
etc and using your own code to append nulls to Ada Strings and
using System.Address.

In Claw we (internally) use RegOpenKeyEx like
     function Reg_Open_Key_Ex(Key     :        Claw.Win32.HKey;
                              lpszSubKey:      Claw.Win32.Lpcstr;
                              dwReserved:      Claw.DWord := 0;
                              samDesired:      Key_Access_Options;
                              phkResult:       PHKey)
     return Reg_Error_Code_Type;
     pragma Import(Stdcall, Reg_Open_Key_Ex, "RegOpenKeyExA");
inside
    procedure Open (Key    : in out Key_Type;
                    Parent : in Key_Type;
                    Name   : in String;
                    Access_Capability : in Access_Capabilities :=
ALLOW_ALL_ACCESS;
                    Creation_Option : Creation_Options := Open_Only);
which uses it with
     C_Name : Interfaces.C.Char_Array
         := Interfaces.C.To_C(Name, Append_Nul=>True);
     Handle : aliased Claw.Win32.HKey;
...
     Result := Reg_Open_Key_Ex(Parent.Handle,
                                 C_Name(0)'Unchecked_Access,
                                 0,     -- reserved
                                 Access_Code(Access_Capability),
                                 Handle'Unchecked_Access);