c++ - Embed resources (eg, shader code; images) into executable/library with CMake

Question

I am writing an application in C++ which relies on various resources in my project. Right now, I have the relative path from the produced executable to each resource hard-coded in my sources, and that allows my program to open the files and read in the data in each resource. This works ok, but it requires that I start the executable from a specific path relative to the resources. So if I try to start my executable from anywhere else, it fails to open the files and cannot proceed.

Is there a portable way to have CMake embed my resources into the executables (or libraries) such that I can simply access them in memory at runtime instead of opening files whose paths are brittle? I have found a related question, and it looks like embedding resources can be done well enough with some ld magic. So my question is how do I do this in a portable, cross platform manner using CMake? I actually need my application run on both x86 and ARM. I am ok with supporting only Linux (Embedded), but bonus points if anyone can suggest how to do this for Windows (Embedded) as well.

EDIT: I forgot to mention a desired property of the solution. I would like to be able to use CMake to cross-compile the application when I am building for ARM rather than have to compile it natively on my ARM target.

Answer 1

As an alternative to the answer of sfstewman, here's a small cmake (2.8) function to convert all files in a specific folder to C data and write them in wished output file:

# Creates C resources file from files in given directory
function(create_resources dir output)
    # Create empty output file
    file(WRITE ${output} "")
    # Collect input files
    file(GLOB bins ${dir}/*)
    # Iterate through input files
    foreach(bin ${bins})
        # Get short filename
        string(REGEX MATCH "([^/]+)$" filename ${bin})
        # Replace filename spaces & extension separator for C compatibility
        string(REGEX REPLACE "\.| |-" "_" filename ${filename})
        # Read hex data from file
        file(READ ${bin} filedata HEX)
        # Convert hex data for C compatibility
        string(REGEX REPLACE "([0-9a-f][0-9a-f])" "0x\1," filedata ${filedata})
        # Append data to output file
        file(APPEND ${output} "const unsigned char ${filename}[] = {${filedata}};
const unsigned ${filename}_size = sizeof(${filename});
")
    endforeach()
endfunction()