Embedded files for CMake projects

A simple tool for embedding files through static arrays, written in C89.

Why would I use this?

1. C23's #embed is cool and may even be supported by a small number of compilers in a decade or two.
2. ld magic is not available on Windows.
3. xxd is an external tool that you have to install, semb builds and runs from CMake.

Why would I not use this?

1. You don't need to embed files.
2. CMake 3.20 is required for cmake_path command.
3. Big files are slow to embed and even slower to compile.
4. Having ~140 LOC dependency is a bit too much for you.

Usage

1. Add this repo as a CMake subdirectory (you only need semb.c and CMakeLists.txt);
2. Use CMake function semb_generate;
3. #include generated file and use embedded data.

The function

semb_generate(<target> OUT <output.h> [BINARY] FILES <file1> [<fileN>...])

What it does:

• adds current binary directory as include directory for target;
• generates output.h in current binary directory during build process:
  • any relative path may be used, e.g. ../foo/bar.h;
  • to #include the generated file simply use the same path;
• adds output.h to the source list of target.
• fileN are paths of files to be embedded:
  • if BINARY option is set, paths are resolved from current binary directory;
  • if BINARY option is not set, paths are resolved from current source directory.

A quick example

semb_generate(my-target OUT embed.h FILES
        ../img/file1.png
        doc/file2.txt
        file3.ext)

Will generate:

static const unsigned char file1_png[] = {
        0x00, 0x00, ...
};
static const unsigned char file2_txt[] = {
        0x00, 0x00, ...
};
static const unsigned char file3_ext[] = {
        0x00, 0x00, ...
};

Full example

Let's make a program that prints its own source code.

Project structure

.
├─ external
│  └─ semb
│     ├─ CMakeLists.txt
│     └─ semb.c
├─ CMakeLists.txt
└─ main.c   

CMakeLists.txt

cmake_minimum_required(VERSION 3.20)
project(example C)

add_subdirectory(external/semb)

add_executable(example main.c)
semb_generate(example OUT embed_main.h FILES main.c)

main.c

#include <stdio.h>
#include "embed_main.h"

int main() {
    for (int i = 0; i < sizeof(main_c); i++) {
        printf("%c", (char)main_c[i]);
    }
    return 0;
}