National Instruments 320685D-01 Forcing Modules that External Modules Refer to into Your Executable or DLL, Using LoadExternalModule on Files in the Project

Chapter 7 Creating and Distributing Standalone Executables and DLLs

National Instruments Corporation 7-15 LabWindows/CVI Programmer Reference Manual

Forcing Modules that External Modules Refer to into Your Executable or DLL

In the LabWindows/CVI development environment, external modules can link to modules in

the Instrument and Library menus regardless of whether you refer to them elsewhere in

your project. However, when you create a standalone executable, LabW indo ws/CVI includes

in the executable only modules that your project refers to directly. If an external module refers

to modules not included in the executable, calls to RunExternalModule or

GetExternalModuleAddr on that external module fail.

To avoid this problem, you must force any missing modules into your executable or DLL.

You can do this when you create your executable or DLL by using the Add Files To

Executable or Add Files To DLL button to display a list of project .lib, project .a,

Instrument, and Library files. Select the files you want to include in your executable or DLL.

If you select a .lib or .a file, it is linked in its entirety.

Alternatively, you can link modules into your executable or DLL by including dummy

references to them in your program. For instance, if your external module references the

functions FuncX and FuncY, include the following statement in your program:

void *dummyRefs[] = {(void *)FuncX, (void *)FuncY};

Using LoadExternalModule on Files in the Project

You can call LoadExternalModule on files listed in the project. You must pass the simple

filename to LoadExternalModule. However, when you create an executable or DLL from

your project, you might have additional work to do:

• If you link your executable or DLL in LabWindows/CVI, the following rules apply for

files listed in the project:

–For

.c or .obj files, everything works automatically.

–For

.dll or .pth files (Windows 3.1 only), refer to the Rules for Using DLL Files

under Windows 3.1 section earlier in this chapter.

–For

.lib files, by default, Create Standalone Executable File or Create Dynamic

Link Library only links in the library modules that you reference statically in the

project. Therefore, you must force into the executable the modules that contain the

functions you call using GetExternalModuleAddr.

To force these modules into the executable, include the library file in the project and

take one of the following actions:

• If you want to force the entire library file into the executable, use the Add Files

to Executable button in the Create Standalone Executable File dialog box, or

the Add Files to DLL button in the Create Dynamic Link Library dialog box.