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Winamp Plugin - Access Violation (plugin dll created with Pelles C)

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viulian:
Hi!

I'm new to this forum, so please excuse me if I posted in the wrong board or if what I'm reporting is not a Pelles C bug.

Here's what happened:

I decided to use Pelles C to write an output plugin for Winamp (5.X). I have downloaded WinAMP SDK 5.0.2 from here: http://www.winamp.com/development/sdk and I use the latest WinAMP (free eddition, the one with installer smaller than 2Mb).

The SDK contains a output plugin example in the folder out_raw.
I imported in in Pelles C (had to set up include/libs directory, and add a couple of libs from Pelles C to the Linker). I've successfully compiled the code, deployed the out_raw.dll (must be named with out_ in front, otherwise plugin won't be even checked) and made Winamp use it.

Whenever I try to press Play -> winamp crashes.
However, If I compile the same code with LCC -> plugin works, winamp works.

Also, I have created my empty output plugin, which defines all the methods that winamp has to call, but all those methods only write to a log file.
When pressing Play, the .dll obtained from Pelles C is only able to execute the setvolume(int) method, then Winamp crashes. In LCC this doesn't happen, and it works.

I know that DLL is generated successfully, the About button works (that is the "void about()" method from plugin DLL gets called no matter how much I press About in Winamp) but when I decide to play a file, winamp is only able to call the setvolume() method and then crashes.

I do not have any other tools to investigate what it actually happens and what's wrong...

I am willing to test the code and switch back to Pelles later on :) I like it better than LCC.
(if you guys want to test LCC with the out_raw plugin, please make sure you select "Do not include underscores in dll exports)" in Project->Configuration.

frankie:
This is not exactly a bug, but as I suspect the problem is due again to the incompatibility between PellesC I/O subsystem and M$.
Try to recompile your library with the following variations:
  1) In project options -> compiler check the "omit default libraries name"
  2) In the linker options add "msvcrt.lib" to the linker stream
This will force linking with M$ runtime.
Now recompile and test the plugin.
Please let me know if this works.

viulian:
Thanks for the answer.

I have tested as you said, but it still fails.

Here are the corresponding lines from the .ppj file:


--- Code: ---CCFLAGS =  -Tx86-coff -Ot -W1 -Gz -Ze -Zl #
ASFLAGS =  -AIA32 -Gz #
RCFLAGS =  #
LINKFLAGS =  -subsystem:windows -machine:ix86 -dll kernel32.lib user32.lib gdi32.lib comctl32.lib msvcrt.lib advapi32.lib delayimp.lib shell32.lib comdlg32.lib msvcrt.lib#
INCLUDE = C:\Program Files\PellesC\Include;C:\Program Files\PellesC\Include\Win;C:\Program Files\PellesC\Include\Win\gl;D:\PellesC\mgui\include#
LIB = C:\Program Files\PellesC\Lib;C:\Program Files\PellesC\Lib\Win#
--- End code ---

(Please ignore the mgui include, I have tried to use that lib too but failed  ;D )

Anyway, I have attached my small plugin. If you have WinAMP installed, you can use the copy.bat file in the project directory to copy the .dll to the destination directory. I rename it in the process.. (i don't think it should cause any problems though).

The path I used for project was


--- Code: ---D:\PellesC\Projects\RemoWamp\
--- End code ---
(so you should unpack the directory in the zip in D:\PellesC\Projects.

Pelle:
It has nothing to do with I/O. Appears to work fine here, provided I fix all the warnings and the calling convention.

frankie:
Yes the problem is the calling convention.
You have to select the __cdecl calling convention from the project compiler options.
Infact the routines in the "Out_Module" structure are __cdecl. This maybe is due to the fact that M$ doesn't convert all calls to __stdcall when windows program is selected.

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