![Cosmopolitan Honeybadger](usr/share/img/honeybadger.png) [![build](https://github.com/jart/cosmopolitan/actions/workflows/build.yml/badge.svg)](https://github.com/jart/cosmopolitan/actions/workflows/build.yml) # Cosmopolitan [Cosmopolitan Libc](https://justine.lol/cosmopolitan/index.html) makes C a build-once run-anywhere language, like Java, except it doesn't need an interpreter or virtual machine. Instead, it reconfigures stock GCC and Clang to output a POSIX-approved polyglot format that runs natively on Linux + Mac + Windows + FreeBSD + OpenBSD + NetBSD + BIOS with the best possible performance and the tiniest footprint imaginable. ## Background For an introduction to this project, please read the [αcτµαlly pδrταblε εxεcµταblε](https://justine.lol/ape.html) blog post and [cosmopolitan libc](https://justine.lol/cosmopolitan/index.html) website. We also have [API documentation](https://justine.lol/cosmopolitan/documentation.html). ## Getting Started If you're doing your development work on Linux or BSD then you need just five files to get started. Here's what you do on Linux: ```sh wget https://justine.lol/cosmopolitan/cosmopolitan-amalgamation-2.2.zip unzip cosmopolitan-amalgamation-2.2.zip printf 'main() { printf("hello world\\n"); }\n' >hello.c gcc -g -Os -static -nostdlib -nostdinc -fno-pie -no-pie -mno-red-zone \ -fno-omit-frame-pointer -pg -mnop-mcount -mno-tls-direct-seg-refs -gdwarf-4 \ -o hello.com.dbg hello.c -fuse-ld=bfd -Wl,-T,ape.lds -Wl,--gc-sections \ -include cosmopolitan.h crt.o ape-no-modify-self.o cosmopolitan.a objcopy -S -O binary hello.com.dbg hello.com ``` You now have a portable program. ```sh ./hello.com bash -c './hello.com' # zsh/fish workaround (we patched them in 2021) ``` If `./hello.com` executed on Linux throws an error about not finding an interpreter, it should be fixed by running the following command (although note that it may not survive a system restart): ```sh sudo sh -c "echo ':APE:M::MZqFpD::/bin/sh:' >/proc/sys/fs/binfmt_misc/register" ``` If the same command produces puzzling errors on WSL or WINE when using Redbean 2.x, they may be fixed by disabling binfmt_misc: ```sh sudo sh -c 'echo -1 >/proc/sys/fs/binfmt_misc/status' ``` Since we used the `ape-no-modify-self.o` bootloader (rather than `ape.o`) your executable will not modify itself when it's run. What it'll instead do, is extract a 4kb program to `${TMPDIR:-${HOME:-.}}` that maps your program into memory without needing to copy it. It's possible to install the APE loader systemwide as follows. ```sh # System-Wide APE Install # for Linux, Darwin, and BSDs # 1. Copies APE Loader to /usr/bin/ape # 2. Registers w/ binfmt_misc too if Linux ape/apeinstall.sh # System-Wide APE Uninstall # for Linux, Darwin, and BSDs ape/apeuninstall.sh ``` It's also possible to convert APE binaries into the system-local format by using the `--assimilate` flag. Please note that if binfmt_misc is in play, you'll need to unregister it temporarily before doing this, since the assimilate feature is part of the shell script header. ```sh $ file hello.com hello.com: DOS/MBR boot sector ./hello.com --assimilate $ file hello.com hello.com: ELF 64-bit LSB executable ``` Now that you're up and running with Cosmopolitan Libc and APE, here's some of the most important troubleshooting tools APE offers that you should know, in case you encounter any issues: ```sh ./hello.com --strace # log system calls to stderr ./hello.com --ftrace # log function calls to stderr ``` Do you love tiny binaries? If so, you may not be happy with Cosmo adding heavyweight features like tracing to your binaries by default. In that case, you may want to consider using our build system: ```sh make m=tiny ``` Which will cause programs such as `hello.com` and `life.com` to shrink from 60kb in size to about 16kb. There's also a prebuilt amalgamation online hosted on our download page . ### MacOS If you're developing on MacOS you can install the GNU compiler collection for x86_64-elf via homebrew: ```sh brew install x86_64-elf-gcc ``` Then in the above scripts just replace `gcc` and `objcopy` with `x86_64-elf-gcc` and `x86_64-elf-objcopy` to compile your APE binary. ### Windows If you're developing on Windows then you need to download an x86_64-pc-linux-gnu toolchain beforehand. See the [Compiling on Windows](https://justine.lol/cosmopolitan/windows-compiling.html) tutorial. It's needed because the ELF object format is what makes universal binaries possible. Cosmopolitan officially only builds on Linux. However, one highly experimental (and currently broken) thing you could try, is building the entire cosmo repository from source using the cross9 toolchain. ``` mkdir -p o/third_party rm -rf o/third_party/gcc wget https://justine.lol/linux-compiler-on-windows/cross9.zip unzip cross9.zip mv cross9 o/third_party/gcc build/bootstrap/make.com ``` ## Source Builds Cosmopolitan can be compiled from source on any Linux distro. First, you need to download or clone the repository. ```sh wget https://justine.lol/cosmopolitan/cosmopolitan.tar.gz tar xf cosmopolitan.tar.gz # see releases page cd cosmopolitan ``` This will build the entire repository and run all the tests: ```sh build/bootstrap/make.com o//examples/hello.com find o -name \*.com | xargs ls -rShal | less ``` If you get an error running make.com then it's probably because you have WINE installed to `binfmt_misc`. You can fix that by installing the the APE loader as an interpreter. It'll improve build performance too! ```sh ape/apeinstall.sh ``` Since the Cosmopolitan repository is very large, you might only want to build a particular thing. Cosmopolitan's build config does a good job at having minimal deterministic builds. For example, if you wanted to build only hello.com then you could do that as follows: ```sh build/bootstrap/make.com o//examples/hello.com ``` Sometimes it's desirable to build a subset of targets, without having to list out each individual one. You can do that by asking make to build a directory name. For example, if you wanted to build only the targets and subtargets of the chibicc package including its tests, you would say: ```sh build/bootstrap/make.com o//third_party/chibicc o//third_party/chibicc/chibicc.com --help ``` Cosmopolitan provides a variety of build modes. For example, if you want really tiny binaries (as small as 12kb in size) then you'd say: ```sh build/bootstrap/make.com m=tiny ``` Here's some other build modes you can try: ```sh build/bootstrap/make.com m=dbg # asan + ubsan + debug build/bootstrap/make.com m=asan # production memory safety build/bootstrap/make.com m=opt # -march=native optimizations build/bootstrap/make.com m=rel # traditional release binaries build/bootstrap/make.com m=optlinux # optimal linux-only performance build/bootstrap/make.com m=fastbuild # build 28% faster w/o debugging build/bootstrap/make.com m=tinylinux # tiniest linux-only 4kb binaries ``` For further details, see [//build/config.mk](build/config.mk). ## GDB Here's the recommended `~/.gdbinit` config: ```gdb set host-charset UTF-8 set target-charset UTF-8 set target-wide-charset UTF-8 set osabi none set complaints 0 set confirm off set history save on set history filename ~/.gdb_history define asm layout asm layout reg end define src layout src layout reg end src ``` You normally run the `.com.dbg` file under gdb. If you need to debug the `.com` file itself, then you can load the debug symbols independently as ``` gdb foo.com -ex 'add-symbol-file foo.com.dbg 0x401000' ``` ## Support Vector | Platform | Min Version | Circa | | :--- | ---: | ---: | | AMD | K8 Venus | 2005 | | Intel | Core | 2006 | | Linux | 2.6.18 | 2007 | | Windows | 8 [1] | 2012 | | Mac OS X | 15.6 | 2018 | | OpenBSD | 6.4 | 2018 | | FreeBSD | 13 | 2020 | | NetBSD | 9.2 | 2021 | [1] See our [vista branch](https://github.com/jart/cosmopolitan/tree/vista) for a community supported version of Cosmopolitan that works on Windows Vista and Windows 7. ## Special Thanks Funding for this project is crowdsourced using [GitHub Sponsors](https://github.com/sponsors/jart) and [Patreon](https://www.patreon.com/jart). Your support is what makes this project possible. Thank you! We'd also like to give special thanks to the following groups and individuals: - [Joe Drumgoole](https://github.com/jdrumgoole) - [Rob Figueiredo](https://github.com/robfig) - [Wasmer](https://wasmer.io/) For publicly sponsoring our work at the highest tier.