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dlw21
USA
18 Posts |
 Posted - 01/30/2003 : 2:18:15 PM
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Hello,
I am looking for tips & tricks for debugging an externally-loaded DLL. I have a DLL (created with VC++ v6.0) loaded with OriginC (via #pragma dll(path\to\dll\file)), and my OriginC code compiles and links with no errors. However, when I run the OriginC code, it bombs out with the cryptic message "External call execution error".
I am wondering how I might obtain more specific info on what has happened. My usual (brain-dead) method involves opening a file within the DLL function and writing strings to it at various points in its execution, but for my current problem it doesn't seem to be getting to the point where it can even open the file.
So, I am looking for any advice on:
- how to get more informative messages from Origin, if possible
- how to attach the VC++ debugger to this DLL after it's been loaded into Origin
- any other tricks that have worked for people in the past
I am using OriginPro 7SR3 on WinXP.
Thanks,
Dave
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cpyang
USA
1406 Posts |
Posted - 01/30/2003 : 2:36:24 PM
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You should always be able to debug your DLL by setting Origin70.exe as the debugging application from your developer studio project.
Maybe you should check the calling convention? Have you tried with
__stdcall
or without?
CP
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eparent
118 Posts |
Posted - 01/30/2003 : 2:45:46 PM
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To debug a DLL:
- Build your DLL with debug information.
- Set a breakpoint in the DLL function you want to debug.
- In VC Project Settings, on the Debug tab, set the Executable to the Origin exe file.
- Start Debug.
Origin will run and VC will become active when Origin loads your DLL and calls the function you put a breakpoint in. You are now able to step through the code for your DLL's function.
If Origin fails to load your DLL or fails to call your function then you will not be able to debug your DLL. This could indicate a problem with the Origin C header file you made for your DLL or how the function is being exported.
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dlw21
USA
18 Posts |
Posted - 01/30/2003 : 2:46:32 PM
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CP,
Thanks for a prompt response. Since posting this note I realized that one of my LabTalk variables is not getting initialized properly. Unfortunately the OGS code looks correct (I posted a thread on the LabTalk forum just now regarding this problem -- see that post for a description) and certainly has not changed since having upgraded from SR2 (it worked in that release).
So my guess is that since an invalid value (NANUM) is being passed to the external DLL, the call is failing (which is reasonable to expect!).
Like I said, this problem appears to have actually started with an assignment statement in a LabTalk OGS file that doesn't produce the expected results:
maxE = Tab.Sys.Egap.v1;
produces NANUM even though the right-hand variable has the correct value (according to the OriginC debugger). Again, this line worked with no problem before SR3.
Perhaps this a bug?
Thanks,
Dave
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How to debug an external DLL?