Re: null and native call question
On 2019-12-29 05:46, WFB wrote: Hi Todd, I am curious, what was the problem? I tried 0 in the first place and the script died. Though it has something to do with the 0 but obviously it has not. Hi Bill, I have a major rewrite underway for several of my modules. Hopefully I will post them her today for evaluation. On the "null and native call question", Native Call translates a zero into a C NULL for you. My run and die issue was not lpReserved being sent a NULL incorrectly. The culprit was M$ and lpType. https://docs.microsoft.com/en-us/windows/win32/api/winreg/nf-winreg-regqueryvalueexw C++ LSTATUS RegQueryValueExW( HKEYhKey, LPCWSTR lpValueName, LPDWORD lpReserved, LPDWORD lpType, LPBYTE lpData, LPDWORD lpcbData ); lpType A pointer to a variable that receives a code indicating the type of data stored in the specified value. For a list of the possible type codes, see Registry Value Types. The lpType parameter can be NULL if the type code is not required. I was sending lpType the value for REG_DWORD (0x0004) and sometimes REG_SZ (0x0001). This caused the call to die with no error message. The ONLY value of lpType that actually works is 0 (NULL). Ha! M$ STRIKES AGAIN! Good gracious I wasted and a lot of others helping me wasted a lot of time on this! AAHHH!!! -T
Re: null and native call question
Hi Todd,
I am curious, what was the problem?
I tried 0 in the first place and the script died. Though it has something
to do with the 0 but obviously it has not.
On Sun, 29 Dec 2019 at 10:31, ToddAndMargo via perl6-users <
perl6-users@perl.org> wrote:
> On 2019-12-29 00:28, ToddAndMargo via perl6-users wrote:
> >>> On Fri, Dec 27, 2019 at 6:06 AM ToddAndMargo via perl6-users
> >>> mailto:perl6-users@perl.org>> wrote:
> >>>
> >>> Hi All,
> >>>
> >>> https://docs.perl6.org/language/nativecall
> >>>
> >>>"As you may have predicted by now, a NULL pointer
> >>>is represented by the type object of the struct type."
> >>>
> >>>
> >>>
> https://docs.microsoft.com/en-us/windows/win32/api/winreg/nf-winreg-regqueryvalueexw
> >>>
> >>>
> >>>C++
> >>>LSTATUS RegQueryValueExW(
> >>> HKEYhKey,
> >>> LPCWSTR lpValueName,
> >>> LPDWORD lpReserved,
> >>> LPDWORD lpType,
> >>> LPBYTE lpData,
> >>> LPDWORD lpcbData
> >>>);
> >>>
> >>>lpReserved
> >>>This parameter is reserved and must be NULL.
> >>>
> >>> With "native", how do I satisfy the "NULL" requirement?
> >>>
> >>> constant WCHAR := uint16;
> >>>
> >>> constant DWORD := int32;
> >>>
> >>>
> >>> sub RegQueryValueExW( DWORD, WCHARS, DWORD, DWORD, DWORD is rw,
> >>> DWORD is
> >>> rw ) is native("Kernel32.dll") returns DWORD { * };
> >>>
> >>> $RtnCode = RegQueryValueExW( $Handle, $lpValueName, int32,
> >>> REG_DWORD,
> >>> $lpData, $lpcbData );
> >>>
> >>> "int32" returns:
> >>>
> >>> Cannot unbox a type object (int32) to int in method
> >>> CALL-ME at C:\rakudo\share\perl6\sources
> >>> \947BDAB9F96E0E5FCCB383124F9
> >>> 23A6BF6F8D76B (NativeCall) line 587
> >>>
> >>>
> >>> Many thanks,
> >>> -T
> >>>
> >
> > On 2019-12-27 06:10, Brad Gilbert wrote:
> >> A Null pointer is just a pointer that points to the address 0.
> >>
> >> So if you are dealing with it as an integer it will be 0.
>
> Hi Brad,
>
> Disregard my last post. I found a booboo somewhere else.
> You were correct about the zero.
>
> Thank you!
>
> -T
>
Re: null and native call question
On 2019-12-29 00:28, ToddAndMargo via perl6-users wrote:
On Fri, Dec 27, 2019 at 6:06 AM ToddAndMargo via perl6-users
mailto:perl6-users@perl.org>> wrote:
Hi All,
https://docs.perl6.org/language/nativecall
"As you may have predicted by now, a NULL pointer
is represented by the type object of the struct type."
https://docs.microsoft.com/en-us/windows/win32/api/winreg/nf-winreg-regqueryvalueexw
C++
LSTATUS RegQueryValueExW(
HKEY hKey,
LPCWSTR lpValueName,
LPDWORD lpReserved,
LPDWORD lpType,
LPBYTE lpData,
LPDWORD lpcbData
);
lpReserved
This parameter is reserved and must be NULL.
With "native", how do I satisfy the "NULL" requirement?
constant WCHAR := uint16;
constant DWORD := int32;
sub RegQueryValueExW( DWORD, WCHARS, DWORD, DWORD, DWORD is rw,
DWORD is
rw ) is native("Kernel32.dll") returns DWORD { * };
$RtnCode = RegQueryValueExW( $Handle, $lpValueName, int32,
REG_DWORD,
$lpData, $lpcbData );
"int32" returns:
Cannot unbox a type object (int32) to int in method
CALL-ME at C:\rakudo\share\perl6\sources
\947BDAB9F96E0E5FCCB383124F9
23A6BF6F8D76B (NativeCall) line 587
Many thanks,
-T
On 2019-12-27 06:10, Brad Gilbert wrote:
A Null pointer is just a pointer that points to the address 0.
So if you are dealing with it as an integer it will be 0.
Hi Brad,
Disregard my last post. I found a booboo somewhere else.
You were correct about the zero.
Thank you!
-T
Re: null and native call question
On Fri, Dec 27, 2019 at 6:06 AM ToddAndMargo via perl6-users
mailto:perl6-users@perl.org>> wrote:
Hi All,
https://docs.perl6.org/language/nativecall
"As you may have predicted by now, a NULL pointer
is represented by the type object of the struct type."
https://docs.microsoft.com/en-us/windows/win32/api/winreg/nf-winreg-regqueryvalueexw
C++
LSTATUS RegQueryValueExW(
HKEYhKey,
LPCWSTR lpValueName,
LPDWORD lpReserved,
LPDWORD lpType,
LPBYTE lpData,
LPDWORD lpcbData
);
lpReserved
This parameter is reserved and must be NULL.
With "native", how do I satisfy the "NULL" requirement?
constant WCHAR := uint16;
constant DWORD := int32;
sub RegQueryValueExW( DWORD, WCHARS, DWORD, DWORD, DWORD is rw,
DWORD is
rw ) is native("Kernel32.dll") returns DWORD { * };
$RtnCode = RegQueryValueExW( $Handle, $lpValueName, int32, REG_DWORD,
$lpData, $lpcbData );
"int32" returns:
Cannot unbox a type object (int32) to int in method
CALL-ME at C:\rakudo\share\perl6\sources
\947BDAB9F96E0E5FCCB383124F9
23A6BF6F8D76B (NativeCall) line 587
Many thanks,
-T
On 2019-12-27 06:10, Brad Gilbert wrote:
A Null pointer is just a pointer that points to the address 0.
So if you are dealing with it as an integer it will be 0.
Hi Brad,
Sending a zero to it causes the program to exit with no
error code.
The offending line is:
$RtnCode = RegQueryValueExW( $Handle, $lpValueName, 0, REG_DWORD,
$lpData, $lpcbData );
Sending it a zero:
say "RegQueryValueExW";
sub RegQueryValueExW( DWORD, WCHARS, DWORD, DWORD, DWORD is rw, DWORD is
rw ) is native("Kernel32.dll") returns DWORD { * };
say "1";
$RtnCode = RegQueryValueExW( $Handle, $lpValueName, 0, REG_DWORD,
$lpData, $lpcbData );
say "2";
say "RegQueryValueExW RtnCode $RtnCode (6 = The handle is invalid; 87
= ERROR_INVALID_PARAMETER)\nlpData pointer $lpData\nlpcbData data length
$lpcbData\n";
RegQueryValueExW
1
Note that it dies without an error code.
Sending it a one:
say "RegQueryValueExW";
sub RegQueryValueExW( DWORD, WCHARS, DWORD, DWORD, DWORD is rw, DWORD is
rw ) is native("Kernel32.dll") returns DWORD { * };
say "1";
$RtnCode = RegQueryValueExW( $Handle, $lpValueName, 1, REG_DWORD,
$lpData, $lpcbData );
say "2";
say "RegQueryValueExW RtnCode $RtnCode (6 = The handle is invalid; 87
= ERROR_INVALID_PARAMETER)\nlpData pointer $lpData\nlpcbData data length
$lpcbData\n";
RegQueryValueExW
1
2
RegQueryValueExW RtnCode 87 (6 = The handle is invalid; 87 =
ERROR_INVALID_PARAMETER)
lpData pointer 0
lpcbData data length 0
I can't win.
:'(
Thank you for the help.
-T
--
~~
Computers are like air conditioners.
They malfunction when you open windows
~~
Re: null and native call question
A Null pointer is just a pointer that points to the address 0.
So if you are dealing with it as an integer it will be 0.
On Fri, Dec 27, 2019 at 6:06 AM ToddAndMargo via perl6-users <
perl6-users@perl.org> wrote:
> Hi All,
>
> https://docs.perl6.org/language/nativecall
>
> "As you may have predicted by now, a NULL pointer
> is represented by the type object of the struct type."
>
>
> https://docs.microsoft.com/en-us/windows/win32/api/winreg/nf-winreg-regqueryvalueexw
>
> C++
> LSTATUS RegQueryValueExW(
> HKEYhKey,
> LPCWSTR lpValueName,
> LPDWORD lpReserved,
> LPDWORD lpType,
> LPBYTE lpData,
> LPDWORD lpcbData
> );
>
> lpReserved
> This parameter is reserved and must be NULL.
>
> With "native", how do I satisfy the "NULL" requirement?
>
> constant WCHAR := uint16;
>
> constant DWORD := int32;
>
>
> sub RegQueryValueExW( DWORD, WCHARS, DWORD, DWORD, DWORD is rw, DWORD is
> rw ) is native("Kernel32.dll") returns DWORD { * };
>
> $RtnCode = RegQueryValueExW( $Handle, $lpValueName, int32, REG_DWORD,
> $lpData, $lpcbData );
>
> "int32" returns:
>
> Cannot unbox a type object (int32) to int in method
> CALL-ME at C:\rakudo\share\perl6\sources \947BDAB9F96E0E5FCCB383124F9
> 23A6BF6F8D76B (NativeCall) line 587
>
>
> Many thanks,
> -T
>
null and native call question
Hi All,
https://docs.perl6.org/language/nativecall
"As you may have predicted by now, a NULL pointer
is represented by the type object of the struct type."
https://docs.microsoft.com/en-us/windows/win32/api/winreg/nf-winreg-regqueryvalueexw
C++
LSTATUS RegQueryValueExW(
HKEYhKey,
LPCWSTR lpValueName,
LPDWORD lpReserved,
LPDWORD lpType,
LPBYTE lpData,
LPDWORD lpcbData
);
lpReserved
This parameter is reserved and must be NULL.
With "native", how do I satisfy the "NULL" requirement?
constant WCHAR := uint16;
constant DWORD := int32;
sub RegQueryValueExW( DWORD, WCHARS, DWORD, DWORD, DWORD is rw, DWORD is
rw ) is native("Kernel32.dll") returns DWORD { * };
$RtnCode = RegQueryValueExW( $Handle, $lpValueName, int32, REG_DWORD,
$lpData, $lpcbData );
"int32" returns:
Cannot unbox a type object (int32) to int in method
CALL-ME at C:\rakudo\share\perl6\sources \947BDAB9F96E0E5FCCB383124F9
23A6BF6F8D76B (NativeCall) line 587
Many thanks,
-T
