lloydtech
15th March 2011 15:48 UTC

VS 2010 NSIS Plugin command not found
Hi,

I am trying to write a new plug-in. The sample plugin source is given below.

[CPP]
#include "Windows.h"
#include "nsis/pluginapi.h" // nsis plugin
#pragma comment(lib,"nsis/pluginapi.lib")
HINSTANCE g_hInstance;

HWND g_hwndParent;

void __declspec(dllexport) InitStorage(HWND hwndParent, int string_size,char *variables, stack_t **stacktop,extra_parameters *extra)
{
g_hwndParent=hwndParent;
EXDLL_INIT();
{
}
}

BOOL WINAPI DllMain(HANDLE hInst, ULONG ul_reason_for_call, LPVOID lpReserved)
{
return TRUE;
}[/CPP]

This plugin is compiled using MS Visual Studio 2010, and put in the plugins directory of NSIS. But when the SCRIPT is compiled with

StorageNSISPlugin::InitStorage

it returns an error "Invalid command StorageNSISPlugin::InitStorage". StorageNSISPlugin is the dll name of the plug-in. All other plugins I download from the NSIS web site is working properly (I am using the prebuilt plugins).

What could be the reason? How can I resolve this?

Thanks,
Lloyd

Anders
15th March 2011 18:08 UTC

My first guess would be wrong calling convention or decorated function exports, nsis export functions are cdecl with no decoration, you could try adding __cdecl after __declspec(dllexport)

(NSIS prints every plugin export at the top of its output when compiling a script)

lloydtech
16th March 2011 04:48 UTC

I have added __cdecl like

void __declspec(dllexport) __cdecl InitStorage(HWND hwndParent, int string_size,char *variables, stack_t **stacktop,extra_parameters *extra)

Now the NSIS compiler is able to find the exported function like this...

"StorageNSISPlugin::?InitStorage@@YAXPAUHWND_@@HPADPAPAU_stack_t@@PAUextra_parameters@@@Z"


This is not as expected. The expected output is "StorageNSISPlugin::InitStorage"

So where could be the mistake?

Does Visaual Studio 2010 has anything to do with this?

Thanks
Lloyd

lloydtech
16th March 2011 05:08 UTC

Solved the problem. As it is a C++ file, the compiler generates that long function name. added the keyword extern "C" in front of the function to solve this.

extern "C" void __declspec(dllexport) InitStorage(HWND hwndParent, int string_size,char *variables, stack_t **stacktop,extra_parameters *extra)

Thanks
Lloyd