Are LVITEM fields puColumns and piColFmt pointers or integers? - windows

After discovering the fields of LVITEM for 64 bit in this question, there is one last thing I don't know. The documentation says that:
puColumns is a UINT. It is a pointer to an array of column indices, specifying which columns are displayed for this item, and the order of those columns.
piColFmt is a int. It is a pointer to an array of the following flags (alone or in combination), specifying the format of each subitem in extended tile view.
My question is why they are integers and not pointers? And in a 64 bit architecture, should they take 8 bytes like pointers or 4 bytes like integers?
Thank you!

So the Windows SDK says:
typedef struct tagLVITEMA
{
UINT mask;
int iItem;
int iSubItem;
UINT state;
UINT stateMask;
LPSTR pszText;
int cchTextMax;
int iImage;
LPARAM lParam;
#if (_WIN32_IE >= 0x0300)
int iIndent;
#endif
#if (_WIN32_WINNT >= 0x0501)
int iGroupId;
UINT cColumns; // tile view columns
PUINT puColumns;
#endif
#if _WIN32_WINNT >= 0x0600 // Will be unused downlevel, but sizeof(LVITEMA) must be equal to sizeof(LVITEMW)
int* piColFmt;
int iGroup; // readonly. only valid for owner data.
#endif
} LVITEMA, *LPLVITEMA;

Related

KBDLLHOOKSTRUCT: Is there a reason why field vkCode is 32-bit unsigned DWORD?

From this page, KBDLLHOOKSTRUCT is defined as:
typedef struct tagKBDLLHOOKSTRUCT {
DWORD vkCode;
DWORD scanCode;
DWORD flags;
DWORD time;
ULONG_PTR dwExtraInfo;
} KBDLLHOOKSTRUCT, *LPKBDLLHOOKSTRUCT, *PKBDLLHOOKSTRUCT;
Field vkCode has type DWORD. According to this page DWORD is defined as A 32-bit unsigned integer.
However, the field docs say: The code must be a value in the range 1 to 254.
Is there an undocumented purpose for the additional 3 bytes of data in this field? Or is this either (a) byte alignment concerns or (b) future expansion of virtual key codes?

NMHDR definition conflict?

in richedit.h NMHDR is defined as follows:
typedef struct _nmhdr
{
HWND hwndFrom;
UINT idFrom;
UINT code;
} NMHDR;
in winuser.h, it is defined as :
typedef struct tagNMHDR
{
HWND hwndFrom;
UINT_PTR idFrom;
UINT code; // NM_ code
} NMHDR;
note that IdFrom went from being a UINT in richedit.h to a UINT_PTR in winuser.h
when compiling for 32bit that won't make a difference but, when compiling for 64bit, the winuser.h idFrom is going to be 4 bytes larger than the richedit.h idFrom.
I suspect that I must be missing something because a difference in size of 4 bytes between the two structures would have broken a fair amount of code out there but, I don't see how that conflict is resolved.
I would appreciate an explanation of how these two seemingly incompatible definitions can coexist. Thank you for your help.

Are Windows HANDLES unsigned 32 bit integers?

per https://en.wikibooks.org/wiki/Windows_Programming/Handles_and_Data_Types#HANDLE,
HANDLEs are defined as being unsigned 32-bit quantities in windows.h
However, in WinDef.h, we see the following:
DECLARE_HANDLE (HWND);
and in winnt.h, we see the following:
#ifdef STRICT
typedef void *HANDLE;
#if 0 && (_MSC_VER > 1000)
#define DECLARE_HANDLE(name) struct name##__; typedef struct name##__ *name
#else
#define DECLARE_HANDLE(name) struct name##__{int unused;}; typedef struct name##__ *name
#endif
#else
typedef PVOID HANDLE;
#define DECLARE_HANDLE(name) typedef HANDLE name
#endif
This tells me that window handles are simple pointers. It seems to me this means that the max size of a window handle depends on the max size of addressable memory, which is 64 bits in most new machines. What am I missing?

KbdLayerDescriptor pVkToWcharTable returns NULL on Win64

I am running out of ideas here. I have a piece of code adapted from http://thetechnofreak.com/technofreak/keylogger-visual-c/ to convert keycodes to unicode chars. It works fine in all situations except when you try to run the 32-bit version from 64-bit Windows. For some reason pKbd->pVkToWcharTable keeps returning NULL. I have tried __ptr64 as well as explicitly specifying SysWOW64 and System32 for the kbd dll path. I have found several items across the internet referring to this exact or very similar problem but I cannot seem to get any of the solutions to work (See: KbdLayerDescriptor returns NULL at 64bit architecture) The following is my test code that was compiled with mingw-32 on Windows XP (gcc -std=c99 Wow64Test.c) and then executed on Windows 7 64-bit. On Windows XP I am getting a valid pointer, however on Windows 7 I am getting NULL.
***Update: So it looks like the problems I am having are due to mingw not implementing __ptr64 correctly as the sizeof operation gives 4 bytes instead of the 8 bytes given by visual studio. So the real solution would be figuring out a way to make the size of KBD_LONG_POINTER dynamic or at least 64-bits but I am not sure if thats possible. Any ideas?
#include <windows.h>
#include <stdio.h>
#define KBD_LONG_POINTER __ptr64
//#define KBD_LONG_POINTER
typedef struct {
BYTE Vk;
BYTE ModBits;
} VK_TO_BIT, *KBD_LONG_POINTER PVK_TO_BIT;
typedef struct {
PVK_TO_BIT pVkToBit;
WORD wMaxModBits;
BYTE ModNumber[];
} MODIFIERS, *KBD_LONG_POINTER PMODIFIERS;
typedef struct _VK_TO_WCHARS1 {
BYTE VirtualKey;
BYTE Attributes;
WCHAR wch[1];
} VK_TO_WCHARS1, *KBD_LONG_POINTER PVK_TO_WCHARS1;
typedef struct _VK_TO_WCHAR_TABLE {
PVK_TO_WCHARS1 pVkToWchars;
BYTE nModifications;
BYTE cbSize;
} VK_TO_WCHAR_TABLE, *KBD_LONG_POINTER PVK_TO_WCHAR_TABLE;
typedef struct {
DWORD dwBoth;
WCHAR wchComposed;
USHORT uFlags;
} DEADKEY, *KBD_LONG_POINTER PDEADKEY;
typedef struct {
BYTE vsc;
WCHAR *KBD_LONG_POINTER pwsz;
} VSC_LPWSTR, *KBD_LONG_POINTER PVSC_LPWSTR;
typedef struct _VSC_VK {
BYTE Vsc;
USHORT Vk;
} VSC_VK, *KBD_LONG_POINTER PVSC_VK;
typedef struct _LIGATURE1 {
BYTE VirtualKey;
WORD ModificationNumber;
WCHAR wch[1];
} LIGATURE1, *KBD_LONG_POINTER PLIGATURE1;
typedef struct tagKbdLayer {
PMODIFIERS pCharModifiers;
PVK_TO_WCHAR_TABLE pVkToWcharTable;
PDEADKEY pDeadKey;
PVSC_LPWSTR pKeyNames;
PVSC_LPWSTR pKeyNamesExt;
WCHAR *KBD_LONG_POINTER *KBD_LONG_POINTER pKeyNamesDead;
USHORT *KBD_LONG_POINTER pusVSCtoVK;
BYTE bMaxVSCtoVK;
PVSC_VK pVSCtoVK_E0;
PVSC_VK pVSCtoVK_E1;
DWORD fLocaleFlags;
BYTE nLgMax;
BYTE cbLgEntry;
PLIGATURE1 pLigature;
DWORD dwType;
DWORD dwSubType;
} KBDTABLES, *KBD_LONG_POINTER PKBDTABLES;
typedef PKBDTABLES(CALLBACK *KbdLayerDescriptor) (VOID);
int main() {
PKBDTABLES pKbd;
HINSTANCE kbdLibrary = NULL;
//"C:\\WINDOWS\\SysWOW64\\KBDUS.DLL"
//"C:\\WINDOWS\\System32\\KBDUS.DLL"
kbdLibrary = LoadLibrary("C:\\WINDOWS\\SysWOW64\\KBDUS.DLL");
KbdLayerDescriptor pKbdLayerDescriptor = (KbdLayerDescriptor) GetProcAddress(kbdLibrary, "KbdLayerDescriptor");
if(pKbdLayerDescriptor != NULL) {
pKbd = pKbdLayerDescriptor();
printf("Is Null? %d 0x%X\n", sizeof(pKbd->pVkToWcharTable), pKbd->pVkToWcharTable);
}
FreeLibrary(kbdLibrary);
kbdLibrary = NULL;
}
It might be late for you, but here is a solution for anyone having the same problem. This demo and incomplete explanation helps, but only works in Visual Studio:
http://www.codeproject.com/Articles/439275/Loading-keyboard-layout-KbdLayerDescriptor-in-32-6
The pointers in the structures in kbd.h all have the KBD_LONG_POINTER macro, which is defined as *__ptr64* on 64 bit operating systems. In Visual Studio, this makes the pointers take up 8 bytes instead of the usual 4 of 32 bit programs. Unfortunately in MinGW, *__ptr64* is defined to not do anything.
As written in the linked explanation, the KbdLayerDescriptor function returns pointers differently on 32 bit and 64 bit Windows. The size of pointers seem to depend on the operating system and not on the running program. Actually, the pointers are still 4 bytes on a 64 bit operating system for a 32 bit program, but in VS, the __ptr64 keyword lies that they are not.
For example some structures look like this in kbd.h:
typedef struct {
BYTE Vk;
BYTE ModBits;
} VK_TO_BIT, *KBD_LONG_POINTER PVK_TO_BIT;
typedef struct {
PVK_TO_BIT pVkToBit;
WORD wMaxModBits;
BYTE ModNumber[];
} MODIFIERS, *KBD_LONG_POINTER PMODIFIERS;
This can't work neither in MinGW nor in VS for 32 bit programs on 64 bit Windows. Because the pVkToBit member in MODIFIERS is only 4 bytes without __ptr64. The solution is to forget about KBD_LONG_POINTER (you could even remove them all) and define structures similar to the above. i.e. :
struct VK_TO_BIT64
{
BYTE Vk;
BYTE ModBits;
};
struct MODIFIERS64
{
VK_TO_BIT64 *pVkToBit;
int _align1;
WORD wMaxModBits;
BYTE ModNumber[];
};
(You could use VK_TO_BIT and not define your own VK_TO_BIT64, as they are the same, but having separate definitions help understanding what's going on.)
The member pVkToBit still takes up 4 bytes, but KbdLayerDescriptor pads pointers to 8 bytes on a 64 bit OS, so we have to insert some padding (int _align1).
You have to do the same thing for the other structures in kbd.h. For example this will replace KBDTABLES:
struct WCHARARRAY64
{
WCHAR *str;
int _align1;
};
struct KBDTABLES64
{
MODIFIERS64 *pCharModifiers;
int _align1;
VK_TO_WCHAR_TABLE64 *pVkToWcharTable;
int _align2;
DEADKEY64 *pDeadKey;
int _align3;
VSC_LPWSTR64 *pKeyNames;
int _align4;
VSC_LPWSTR64 *pKeyNamesExt;
int _align5;
WCHARARRAY64 *pKeyNamesDead;
int _align6;
USHORT *pusVSCtoVK;
int _align7;
BYTE bMaxVSCtoVK;
int _align8;
VSC_VK64 *pVSCtoVK_E0;
int _align9;
VSC_VK64 *pVSCtoVK_E1;
int _align10;
DWORD fLocaleFlags;
byte nLgMax;
byte cbLgEntry;
LIGATURE64_1 *pLigature;
int _align11;
DWORD dwType;
DWORD dwSubType;
};
(Notice that the _align8 member does not come after a pointer.)
To use this all, you have to check whether you are running on 64 bit windows with this: http://msdn.microsoft.com/en-us/library/ms684139%28v=vs.85%29.aspx
If not, use the original structures from kbd.h, because the pointers behave correctly. They take up 4 bytes. In case the program is running on a 64 bit OS, use the structures you created. You can achieve it with this:
typedef __int64 (CALLBACK *LayerDescriptor64)(); // Result should be cast to KBDTABLES64.
typedef PKBDTABLES (CALLBACK *LayerDescriptor)(); // This is used on 32 bit OS.
static PKBDTABLES kbdtables = NULL;
static KBDTABLES64 *kbdtables64 = NULL;
And in some initialization function:
if (WindowsIs64Bit()) // Your function that checks the OS version.
{
LayerDescriptor64 KbdLayerDescriptor = (LayerDescriptor64)GetProcAddress(kbdLibrary, "KbdLayerDescriptor");
if (KbdLayerDescriptor != NULL)
kbdtables64 = (KBDTABLES64*)KbdLayerDescriptor();
else
kbdtables64 = NULL;
}
else
{
LayerDescriptor KbdLayerDescriptor = (LayerDescriptor)GetProcAddress(kbdLibrary, "KbdLayerDescriptor");
if (KbdLayerDescriptor != NULL)
kbdtables = KbdLayerDescriptor();
else
kbdtables = NULL;
}
This solution does not use __ptr64 at all, and works both in VS and MinGW. The things you have to watch out for are:
The structures should be aligned on 8 byte boundaries. (This is the default in current VS or MinGW, at least for C++.)
Don't define KBD_LONG_POINTER to __ptr64, or remove it from everywhere. Although you are better off not changing kbd.h.
Understand how alignment for structure members work. (I have compiled this as C++ and not C. I'm not sure whether alignment rules would be any different for C.)
Use the correct variable (either kbdtables or kbdtables64) depending on the OS.
This solution is obviously not needed when compiling a 64 bit program.

I'm passing a struct pointer to my kernel -- how can I make that data accessible to helper functions?

Good day, folks!
I have a structure with 100+ parameters needed by my kernel. I create a buffer object for the data, do the write, and set a pointer to that data as a kernel argument. (The kernel arg is __global, but I've tried other types for it.)
So far so good! I can see the structure's elements from my kernel function just fine!
However, I want a dozen helper functions to have access to these parameters. I have tried, but I haven't found a way to do this. If I try to copy the (__global) vh into another global pointer, or a __local pointer, or a __private pointer, it fails. If I try to copy the structure data itself into a __global, or __local, or __private copy of the structure, it fails. I've tried byte-wise copies, I've tried async_work_group_copy, I've tried casts, I tried passing the whole __global pointer in to the helper functions, I've tried other types for the kernel arg itself, I've tried everything I can think of. It seems that it might not be possible to get this data to these helper functions, but it must be possible, right?
Any answer will be welcome, even if it's "that can't be done", or "you're an idiot". I've asked this question on another forum and had nobody has said even that much, though perhaps I didn't word my question properly. But ... I can't be the only person in the world with helper functions in their kernel code, right? How the heck do you get data to them that was passed in to the kernel function?
Thanks folks....
David
Thanks....
Here is an example which demonstrates the functionality you want, hope it helps!
Structure definitions:
typedef struct agent {
uint energy;
uint action;
uint type;
uint next;
} AGENT __attribute__ ((aligned (16)));
typedef struct sim_params {
uint size_x;
uint size_y;
uint size_xy;
uint max_agents;
uint null_agent_pointer;
uint grass_restart;
uint lines_per_thread;
} SIM_PARAMS;
typedef struct cell {
uint grass;
uint agent_pointer;
} CELL;
Helper function:
/*
* Helper function
*/
void removeAgentFromCell(__global AGENT * agents,
__global CELL * matrix,
uint cellIndex,
uint agentIndex,
uint previousAgentIndex,
SIM_PARAMS sim_params)
{
...
}
Main kernel:
/*
* The kernel
*/
__kernel void step1(__global AGENT * agents,
__global CELL * matrix,
__global ulong * seeds,
const uint turn,
const SIM_PARAMS sim_params)
{
uint index;
uint agentIndex;
uint previousAgentIndex;
...
// Call helper function
removeAgentFromCell(agents, matrix, index, agentIndex, previousAgentIndex, sim_params);
...
}
Tried and tested and working in AMD APP SDK (on both CPU and GPU) and Nvidia CUDA Toolkit. So I guess it will work in OSX.

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