[fpc-devel] LoadLibrary fails if called from a DLL

Yury Sidorov jura at cp-lab.com
Sun Jul 8 18:28:32 CEST 2007


How old is snapshot you are using?

Yury Sidorov.

----- Original Message ----- 
From: Mark - WBIsoft.COM 
To: fpc-devel at lists.freepascal.org 
Sent: Saturday, July 07, 2007 11:51 AM
Subject: [fpc-devel] LoadLibrary fails if called from a DLL


I'm having a strange issue with the LoadLibrary call in the 64bit beta version of the free pascal compiler (fpc 2.1.5 with lazarus 0.9.23 beta) - standard install from the sourceforge download and installed in the default c:\lazarus directory.

I have written a function in FPC that I have used in Delphi for many many years with out problem.  Ok, here's a simple piece of code

function myfunction(a, var b : dword) : boolean;
var  dllh : cardinal;
      fun : function (a : dword; var b : dword) : boolean; stdcall;
   result := false;

   dllh := loadlibrary('c:\windows\system32\somelib.dll');
   if dllh <> 0 then
      fun := nil;
      fun := getprocaddress(dllh,'someproc');
      if fun <> nil then result := fun(a,b);
      result := false;

Now here's my problem - very simply if I compile this into a standard console application it works fine, however, if I compile it into the DLL I am planing to run it in it fails - the loadlibrary call ALWAYS returns 0x7C370000 which appears to be a memory address rather than a handle - the result is that the getprocaddress returns an invalid address and fails.

So, why is the loadlibrary call failing (or returning this memory address) when in a DLL but NOT when it's in a console app.

Any help would be great, as I cannot seem to find an implementation of GETLASTERROR to pass to SYSERRORMESSAGE to display any error from the OS if there is one !

Thanks folks


Kind regards

Mark Cook

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