Single File Library Amalgamation Tool for C and C++

This combine.py script amalgamates C and C++ sources, with the idea to create a single source file that's easy to integrate into projects.

To use, just create a source file that lists the files to combine using #include directives, along with any relevant flags, e.g.:

#define DISABLE_FEATURE

#include "my-header.h"
#include "my-file-1.c"
#include "my-file-2.c"

Then tell the script where to find the sources, this descriptor file, and where to write the output:

python3 combine.py -r sources/root/folder -o my-lib.c input.c

The included files, plus their included files recursively, will be combined into the single output file (or stdout if no output is supplied). You can specify files to exclude, using the -x option, or files you wish to keep as includes, using the -k option. The options are documented in the help:

% ./combine.py --help
usage: combine.py [-h] [-r ROOT] [-x EXCLUDE] [-k KEEP] [-p] [-o OUTPUT] input

Amalgamate Tool

positional arguments:
  input                 input file

optional arguments:
  -h, --help            show this help message and exit
  -r ROOT, --root ROOT  file root search path
  -x EXCLUDE, --exclude EXCLUDE
                        file to completely exclude from inlining
  -k KEEP, --keep KEEP  file to exclude from inlining but keep the include
                        directive
  -p, --pragma          keep any "#pragma once" directives (removed by
                        default)
  -o OUTPUT, --output OUTPUT
                        output file (otherwise stdout)

example: ./combine.py -r ../my/path -r ../other/path -o out.c in.c

See the Zstandard project for examples of using the script, along with sample code showing the generated single-file libraries used. Here, in the decompression library example, all the optimisation flags and build choices are added into zstddeclib-in.c, the resulting file #included, then a single call to ZSTD_decompress() is all it takes to use.