OpenEuphoria

Re: using dlls

• Posted by "Elliott S. de Andrade" <quantum_analyst at hotmail.com> Nov 21, 2003
• 625 views

Well.... It's just something I know. I used Dependency Walker to find out 
the actual exported names from the DLL. Because they had a _, I knew they 
were probably cdecl (C calling convention), so you needed to add a '+' to 
the name.

>From: Rubens Monteiro Luciano <rml at rubis.trix.net>
>Subject: Re: using dlls
>
>ok, thanks Ellilott, it works.
>Where did you find this information (the "+_") ?
>Could you show me where the this document is located?
>
>
>Rubens
>
>At 03:21 16/11/2003, you wrote:
>>
>>
>>    Well, there seems to be a few problems. Firstly, you don't need 
>>win32lib.ew to define DLL functions, you should be using dll.e. For d1 and 
>>e1, you are including the parameters in the name. Also, the functions that 
>>have (void) do not take any parameters. Another thing you may not have 
>>found is that the functions have underscores prepended to them. This means 
>>that they probably use the C calling convention. This doesn't cause a 
>>problem when you define the function, but when you call it, it would 
>>probably crash. That means you will need to use eu 2.4. The only way to 
>>get around that is to re-compile the DLL. Here's some fixed code:
>>
>>include dll.ew
>>atom ad, a1,b1,c1,d1,e1
>>
>>ad = open_dll("dxsoftex.dll")
>>
>>a1 = define_c_func(ad,"+_DxsoftExchangeInit", {C_INT}, C_INT)
>>b1 = define_c_func(ad,"+_DxsoftGetSymFromRxBuffer",{}, C_INT)
>>c1 = define_c_func(ad,"+_DxsoftPutSymToTxBuffer",{C_CHAR}, C_INT)
>>d1 = define_c_func(ad,"+_DxsoftGetSymFromTxBuffer",{}, C_INT)
>>e1 = define_c_func(ad,"+_DxsoftPutSymToRxBuffer",{C_CHAR}, C_INT)
>>
>>printf(1, "%d\n%d\n%d\n%d\n%d\n%d\n", {ad, a1, b1, c1, d1, e1})
>>
>>
>>>From: Rubens Monteiro Luciano <rml at rubis.trix.net>
>>>Reply-To: EUforum at topica.com
>>>To: EUforum at topica.com
>>>Subject: using dlls
>>>Date: Sun, 16 Nov 2003 02:31:21 -0200
>>>
>>>
>>>Hi all !
>>>         I'm just starting using external dlls and need some help.
>>>
>>>The dll is dxsoftex.dll  (from <http://www.dxsoft.com/dxs-exch.zip> )and
>>>the functions are these:
>>>
>>>--int DxsoftExchangeInit(int canal_number);
>>>--int DxsoftGetSymFromRxBuffer(void);
>>>--int DxsoftPutSymToTxBuffer(char sym);
>>>--int DxsoftGetSymFromTxBuffer(void);
>>>--int DxsoftPutSymToRxBuffer(char sym);
>>>
>>>the code:
>>>
>>>include win32lib.ew
>>>atom ad
>>>integer a1,b1,c1,d1,e1,a
>>>
>>>ad = open_dll("dxsoftex.dll")
>>>puts(1,sprint(ad)&"\n")    ------ ad gives 9895936
>>>
>>>a1 = define_c_func(ad,"DxsoftExchangeInit", {C_INT}, C_INT)
>>>puts(1, sprint(a1)&"\n")
>>>b1 = define_c_func(ad,"DxsoftGetSymFromRxBuffer",{C_CHAR}, C_INT)
>>>puts(1, sprint(b1)&"\n")
>>>c1 = define_c_func(ad,"DxsoftPutSymToTxBuffer",{C_CHAR}, C_INT)
>>>puts(1, sprint(c1)&"\n")
>>>d1 = define_c_func(ad,"DxsoftGetSymFromTxBuffer(void)",{C_CHAR}, C_INT)
>>>puts(1, sprint(d1)&"\n")
>>>e1 = define_c_func(ad,"DxsoftPutSymToRxBuffer(char sym)",{C_CHAR}, 
>>>C_INT)=
>>>
>>>puts(1, sprint(e1)&"\n")
>>>
>>>
>>>I stopped here because a1..e1 gives every time only the value -1
>>>which means that these functions "could not be found".
>>>What am I doing wrong ?
>>>
>>>Thanks
>>>
>>>Rubens
>>
>