Using Relative Paths with Matlab Coder

Question

I am trying to generate C code for a Matlab function. It uses mongoose web server for communication. If I place the .h/.c files in the same folder as the .m file I can compile everything fine using:

coder.cinclude('mongoose.h');
coder.updateBuildInfo('addSourceFiles','mongoose.c');
coder.cinclude('rest.h');
coder.updateBuildInfo('addSourceFiles','rest.c');

I would like to keep my .c files and .m files separate, so moving C files to a folder named native/ causes compilation to fail as expected. Thus, I tell Matlab where to find them using:

customDir = '/full/path/to/native';
coder.updateBuildInfo('addIncludePaths', customDir);
coder.updateBuildInfo('addSourcePaths', customDir);

Which works. However it works only with absolute paths and not with relative paths. This is a problem since each contributor to this projects keeps the source folder in a different location. What is the proper way to tell Matlab native file locations using relative paths to Matlab working directory?

Mefitico Mefitico · Accepted Answer · 2019-10-21T16:25:49

If you just want to generate C code (and not compile), I'd suggesting adding the relative locations to those files to the Matlab Path. You can do this with:

addpath('the_relative_path_to_native')

Or even better:

addpath(fullfile(cd(), 'the_relative_path_to_native'))

After issuing this command, Matlab searches this folder for .m function as well as included C files. This should solve your problem as described.

But later, if you want to compile the generated code, the included folders will not be copied/merged/included in the codegen directory created by Matlab, so you should handle that in a different manner, such as including the directory in your custom makefile os adding a command to copy the required files to a folder convenient for compilation.

Using Relative Paths with Matlab Coder

2 Answers