When I utilize “loadlibrary”to load dll file, it shows that，“Error using loadlibrary Failed to preprocess the input file.”

When I utilize “loadlibrary”to load dll file, it shows that，“Error using loadlibrary Failed to preprocess the input file.” ,and fails.

Does the .dll file or .h file,need to be add or delete extra codes to format?

This is my code,of which the m-file is placed with sisl.dll and sisl.h:

if ~libisloaded('sisl')

loadlibrary('sisl','sisl.h');

end

Answer 1

[sanidhyak]

Hi @Junnan Chen,

I understand that you are facing the error "Failed to preprocess the input file" while using “loadlibrary” function in MATLAB to load “sisl.dll”. This issue usually occurs due to missing dependencies, incorrect header file formatting, or compiler configuration problems.

You can try the following workarounds for the same:

1. Make sure that “sisl.h” is correctly formatted and contains function prototypes. You should simplify any complex preprocessing directives (“#define” macros) or provide a preprocessed version of the file.

2. You can modify the provided code as follows:

if ~libisloaded('sisl') 
    loadlibrary('sisl', 'sisl.h', 'mfilename', 'sisl_proto'); 
end 

This will generate an “M-file” to assist MATLAB in handling the “DLL” functions.

3. You can check MATLAB’s compiler setup by running:

mex -setup 

If no compiler is set, install a compatible one from MATLAB’s supported compilers list.

4. If “sisl.h” references other headers, manually include them using:

loadlibrary('sisl', @sisl_proto); 

5. Ensure “sisl.dll” is compiled for the same MATLAB architecture (64-bit vs. 32-bit). Check for missing dependencies using:

Windows:

depends sisl.dll

Linux:

ldd sisl.dll 

6. If the header file is problematic, try loading the DLL without it:

loadlibrary('sisl', '', 'alias', 'sisl'); 

For more details, refer to “loadlibrary” in MATLAB documentation:

• https://www.mathworks.com/help/matlab/ref/loadlibrary.html

I hope this helps!