The example code is written in CBuilder,but I cannot make it in masm,please help me!
The .cpp is:
//---------------------------------------------------------------------------
#pragma hdrstop
#include "Unit1.h"
//---------------------------------------------------------------------------
#pragma package(smart_init)
#pragma resource "*.dfm"
TForm1 *Form1;
//---------------------------------------------------------------------------
__fastcall TForm1::TForm1(TComponent* Owner)
: TForm(Owner)
{
}
char* (__stdcall *GetNumber)(int, char*);
int (__stdcall *GetSize)(int, char*);
HINSTANCE DllInst = NULL;
//---------------------------------------------------------------------------
void __fastcall TForm1::Button2Click(TObject *Sender)
{
char* Code = "012345678910";
int i;
i = edt->Text.ToInt();
if (DllInst == NULL) DllInst = LoadLibrary("Get.dll");
if (DllInst)
{
GetNumber = (char* (__stdcall*)(int, char*))GetProcAddress(DllInst,"GetNumber");
GetSize = (int (__stdcall*)(int, char*))GetProcAddress(DllInst,"GetSize");
//Call GetNumber
Edit1->Text = GetNumber(i, Code);
//Call GetSize
Edit2->Text = GetSize(i, Code);
}
}
//---------------------------------------------------------------------------
void __fastcall TForm1::Button3Click(TObject *Sender)
{
Close();
}
//---------------------------------------------------------------------------
void __fastcall TForm1::FormClose(TObject *Sender, TCloseAction &Action)
{
if ( DllInst ) FreeLibrary (DllInst);
}
//---------------------------------------------------------------------------
How can I change it to MASM format, I cannot make the "GetNumber = (char* (__stdcall*)(int, char*))GetProcAddress(DllInst,"GetNumber");" and "Edit1->Text = GetNumber(i, Code);" clear.
Go through and write out what it's doing. Then do each thing in MASM.
Don't try and convert C++ code directly to assembly - it'll be far less efficient and probably harder then writing the code from scratch.
Eric,
Zooba is right, just recode it, its quicker. Here is a quick example.
GetNumber = (char* (__stdcall*)(int, char*))GetProcAddress(DllInst,"GetNumber");
GetSize = (int (__stdcall*)(int, char*))GetProcAddress(DllInst,"GetSize");
; manual code
LOCAL GetNumber :DWORD
LOCAL GetSize :DWORD
.data
pGetNumber db "GetNumber",0
pGetSize db "GetSize",0
.code
invoke GetProcAddress,DllInstance,ADDR pGetNumber
mov GetNumber, eax
invoke GetProcAddress,DllInstance,ADDR pGetSize
mov GetSize, eax
; masm32 macro code
LOCAL GetNumber :DWORD
LOCAL GetSize :DWORD
mov GetNumber, rv(GetProcAddress,DllInstance,"GetNumber")
mov GetSize, rv(GetProcAddress,DllInstance,"GetSize")
Quote from: hutch-- on March 22, 2006, 04:24:24 AM
Eric,
Zooba is right, just recode it, its quicker. Here is a quick example.
GetNumber = (char* (__stdcall*)(int, char*))GetProcAddress(DllInst,"GetNumber");
GetSize = (int (__stdcall*)(int, char*))GetProcAddress(DllInst,"GetSize");
; manual code
LOCAL GetNumber :DWORD
LOCAL GetSize :DWORD
.data
pGetNumber db "GetNumber",0
pGetSize db "GetSize",0
.code
invoke GetProcAddress,DllInstance,ADDR pGetNumber
mov GetNumber, eax
invoke GetProcAddress,DllInstance,ADDR pGetSize
mov GetSize, eax
; masm32 macro code
LOCAL GetNumber :DWORD
LOCAL GetSize :DWORD
mov GetNumber, rv(GetProcAddress,DllInstance,"GetNumber")
mov GetSize, rv(GetProcAddress,DllInstance,"GetSize")
Thanks zooba and hutch!
I suppose translate is the the first step of recode :red , I just want to learn the approach of how to load and use the dll.
There is still a problem for me! I knew the "GetNumber = (char* (__stdcall*)(int, char*))GetProcAddress(DllInst,"GetNumber");" can be recode to:
invoke GetProcAddress,DllInstance,ADDR pGetNumber
mov GetNumber, eaxBut the "Edit1->Text = GetNumber(i, Code);" made me puzzled. Can I recode it to:
invoke GetNumber,i,ADDR Code
mov Text, eax
invoke SetDlgItemText,hWnd,IDC_Edit1,addr GetNumberGetNumber is just a DWORD variable...so...
If GetNumber is just a DWORD variable, why are you calling it as a procedure two lines earlier?
invoke GetNumber,i,ADDR Code ; Getnumber is a procedure, here
mov Text, eax
invoke SetDlgItemText,hWnd,IDC_Edit1,addr GetNumber ;GetNumber is a DWORD variable, here
This cannot be done.
Paul
Quote from: PBrennick on March 22, 2006, 05:28:03 PM
If GetNumber is just a DWORD variable, why are you calling it as a procedure two lines earlier?
invoke GetNumber,i,ADDR Code ; Getnumber is a procedure, here
mov Text, eax
invoke SetDlgItemText,hWnd,IDC_Edit1,addr GetNumber ;GetNumber is a DWORD variable, here
This cannot be done.
Paul
Yes, that's why I'm confused.
How can I recode the "Edit1->Text = GetNumber(i, Code);" sentence?
at a guess, its going to set edit1 (editbox?) text value to the result from the call.. most likely doing a wsprintfa or something to convert the data
Yes, But...
GetNumber = (char* (__stdcall*)(int, char*))GetProcAddress(DllInst,"GetNumber");
Edit1->Text =[b] GetNumber(i, Code);[/b]
Who can explain the bold for me, ThX.
A function names 'GetNumber' is called with parameters 'i' and 'Code', and the return value is copied to Edit1->Text.
Now, depending on what Edit1->Text is, this could be very complicated or very simple...
Quote from: zooba on March 24, 2006, 08:06:15 AM
A function names 'GetNumber' is called with parameters 'i' and 'Code', and the return value is copied to Edit1->Text.
Now, depending on what Edit1->Text is, this could be very complicated or very simple...
I do it but it the sentence "invoke GetNumber,i,addr Code" tells error: error A2190: INVOKE requires prototype for procedure
The code I write is:
.data?
hDllInstance dd ?
i dd ?
GetNumber dd ?
GetSize dd ?
.data
szDll db 'Get.dll',0
.const
Code db '000000000000',0
pGetNumber db 'GetNumber',0
pGetSize db 'GetSize',0
invoke GetDlgItemInt,hWnd,IDC_NUM,NULL,FALSE
mov i,eax
invoke LoadLibrary,addr szDll
.if eax
mov hDllInstance,eax
invoke GetProcAddress,hDllInstance,addr pGetNumber
mov GetNumber,eax
invoke GetProcAddress,hDllInstance,addr pGetSize
mov GetSize,eax
invoke GetNumber,i,addr Code
invoke SetDlgItemText,hWnd,IDC_Edit1,addr GetNumber
invoke GetSize,i,addr Code
invoke SetDlgItemInt,hWnd,IDC_Edit2,GetSize,FALSEWhere did I make mistake? ThX.
Quote from: Eric4ever on March 24, 2006, 10:17:11 AM
I do it but it the sentence "invoke GetNumber,i,addr Code" tells error: error A2190: INVOKE requires prototype for procedure
Hi Eric. A procedure is simply a type-defined function. It is used like this:
ProcedureName PROC <USES ESI EDI etc> <var1:DWORD, var2:DWORD, etc...>
<assembler commands...>
RET
ProcedureName ENDP
A procedure prototype defines the procedure. It is used as:
ProcedureName PROTO <:DWORD, :DWORD, etc...>
So to make a functional procedure, you have to do something like this:
; my App v1.0
myFunction PROTO :DWORD, :DWORD
.data
szText DB "Hi there!",0
szTitle DB "My Message",0
.code
start:
invoke myFunction,addr szText,addr szTitle
invoke ExitProcess,0
myFunction PROC text:DWORD,title:DWORD
invoke MessageBox,0,text,title,MB_OK
ret
myFunction ENDP
end start
Thank you Mark.
I tried many times but there always has an error,I use "push Code" the error happens:
push Code ; error A2070: invalid instruction operands
The Code defined in the .const
Code db '000000000000',0 ; It's a character string which has 12 bytes
And I tried "push offset Code", it link well but run error!
Here is my code:
.data?
DllInstance dd ?
i dd ?
GetNumber dd ?
GetSize dd ?
.data
szDll db "Get.dll",0
szVerbOpen db "open",0
.const
szError db 'Get.dll Missing!',0
Code db '000000000000',0
pGetNumber db 'GetNumber',0
pGetSize db 'GetSize',0
invoke GetDlgItemInt,hWnd,IDC_NUM,NULL,FALSE ; IDC_NUM is a EDITTEXT
mov i,eax
invoke LoadLibrary,addr szDll
.if eax
mov DllInstance,eax
invoke GetProcAddress,DllInstance,addr pGetNumber
mov GetNumber,eax
invoke GetProcAddress,DllInstance,addr pGetSize
mov GetSize,eax
.else
invoke MessageBox,hWnd,addr szError,NULL,MB_OK or MB_ICONWARNING
.endif
push offset Code
push i
call dword ptr [GetNumber]
invoke SetDlgItemText,hWnd,IDC_Edit,addr GetNumber ; IDC_Edit is a EDITTEXT(display the result)
...
THX.
Quote from: Eric4ever on March 28, 2006, 01:38:28 AM
I tried many times but there always has an error,I use "push Code" the error happens:
push Code ; error A2070: invalid instruction operands
The Code defined in the .const
Code db '000000000000',0 ; It's a character string which has 12 bytes
And I tried "push offset Code", it link well but run error!
Hi Eric. Here "Code" is a label for your 12 bytes. PUSH can only accept WORDs and DWORDs as Register and Memory arguments, so pushing BYTEs is not allowed. "Push offset Code" works because the
offset of Code is a DWORD, which can be pushed. To make this a little more confusing, you CAN push any immediate value (including a byte) but all immediates are pushed as DWORDs. Here are most of the legal ways the push command can be used:
.data
three DD 3 ; DWORD
two DW 2 ; WORD
one DB 1 ; BYTE
.code
push EAX ; eax is a DWORD, ESP-4
push AX ; ax is a WORD, ESP-2!
push AL ; this is not allowed!
push three ; dwords are ok, ESP-4
push two ; so are words, ESP-2
push one ; BYTEs cannot be pushed this way!
push 12345678h ; this is a DWORD, "12345678h" is pushed, ESP-4
push 1234h ; this is a WORD, "00001234h" is pushed, ESP-4
push 12h ; this IS acceptable, "00000012h" is pushed, ESP-4
push OFFSET three ; ok, the DWORD address of "three" is pushed, ESP-4
push OFFSET two ; ditto, ESP-4
push OFFSET one ; ditto, ESP-4
push [EAX+ECX] ; this adds EAX+ECX as DWORD offset, ESP-4
Pushing immediate values of any size is allowed simply because the value is zero-extended and stored as a DWORD. If you "push 13" then "0000000Dh" gets written to the current ESP.
ESP is the 32-bit stack pointer. It points to the current stack offset. If you push a DWORD to the stack, it is stored at ESP and then ESP decrements by 4, so the next value can be entered. Pushing WORD values decrements ESP by 2, so two WORD pushes are required to make one DWORD entry.
You can access values from the stack by the ESP value. Take this for instance:
push 11111111h
push 12345678h
mov EAX,DWORD PTR [ESP+0] ; eax == "12345678h"
mov EAX,DWORD PTR [ESP+4] ; eax == "11111111h"
mov EAX,22222222h
movzx EAX,WORD PTR [ESP+0] ; eax == "00005678h"
movzx EAX,WORD PTR [ESP+2] ; eax == "00001234h"
mov EAX,22222222h
mov AX,WORD PTR [ESP+0] ; eax == "22225678h"
mov AX,WORD PTR [ESP+2] ; eax == "22221234h"
mov EAX,DWORD PTR [ESP+0] ; eax == "12345678h"
mov EAX,DWORD PTR [ESP+1] ; eax == "11123456h"
mov EAX,DWORD PTR [ESP+2] ; eax == "11111234h"
mov EAX,DWORD PTR [ESP+3] ; eax == "11111112h"
Hope that helps. :bg
Quote from: Mark Jones on March 28, 2006, 07:00:31 PM
Hi Eric. Here "Code" is a label for your 12 bytes. PUSH can only accept WORDs and DWORDs as Register and Memory arguments, so pushing BYTEs is not allowed. "Push offset Code" works because the offset of Code is a DWORD, which can be pushed. To make this a little more confusing, you CAN push any immediate value. Here are most of the legal ways the push command can be used:
----snip----
Hope that helps. :bg
Hi Mark,
Thanks for your kindly help and explanation :U
I got it :green
Regards,
Eric