cosmopolitan README

The project's README from github.com/jart/cosmopolitan. As one markdown file: README.md.

Cosmopolitan Honeybadger

build

Cosmopolitan

Cosmopolitan Libc makes C/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 7.3 + NetBSD + BIOS with the best possible performance and the tiniest footprint imaginable.

Background

For an introduction to this project, please read the actually portable executable blog post and cosmopolitan libc website. We also have API documentation.

Getting Started

You can start by obtaining a release of our cosmocc compiler from https://cosmo.zip/pub/cosmocc/.

mkdir -p cosmocc
cd cosmocc
wget https://cosmo.zip/pub/cosmocc/cosmocc.zip
unzip cosmocc.zip

Here's an example program we can write:

// hello.c
#include <stdio.h>

int main() {
  printf("hello world\n");
}

It can be compiled as follows:

cosmocc -o hello hello.c
./hello

The Cosmopolitan Libc runtime links some heavyweight troubleshooting features by default, which are very useful for developers and admins. Here's how you can log system calls:

./hello --strace

Here's how you can get a much more verbose log of function calls:

./hello --ftrace

You can use the Cosmopolitan's toolchain to build conventional open source projects which use autotools. This strategy normally works:

export CC=x86_64-unknown-cosmo-cc
export CXX=x86_64-unknown-cosmo-c++
./configure --prefix=/opt/cosmos/x86_64
make -j
make install

Cosmopolitan Source Builds

Cosmopolitan can be compiled from source on any of our supported platforms. The Makefile will download cosmocc automatically.

It's recommended that you install a systemwide APE Loader. This command requires sudo access to copy the ape command to a system folder and register with binfmt_misc on Linux, for even more performance.

ape/apeinstall.sh

You can now build the mono repo with any modern version of GNU Make. To bootstrap your build, you can install Cosmopolitan Make from this site:

https://cosmo.zip/pub/cosmos/bin/make

E.g.:

curl -LO https://cosmo.zip/pub/cosmos/bin/make
./make -j8
o//examples/hello

After you've built the repo once, you can also use the make from your cosmocc at .cosmocc/current/bin/make. You might even prefer to alias make to $COSMO/.cosmocc/current/bin/make.

Since the Cosmopolitan repository is very large, you might only want to build one particular thing. Here's an example of a target that can be compiled relatively quickly, which is a simple POSIX test that only depends on core LIBC packages.

rm -rf o//libc o//test
.cosmocc/current/bin/make o//test/posix/signal_test
o//test/posix/signal_test

Sometimes it's desirable to build a subset of targets, without having to list out each individual one. For example if you wanted to build and run all the unit tests in the TEST_POSIX package, you could say:

.cosmocc/current/bin/make o//test/posix

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:

.cosmocc/current/bin/make m=tiny

You can furthermore cut out the bloat of other operating systems, and have Cosmopolitan become much more similar to Musl Libc.

.cosmocc/current/bin/make m=tinylinux

For further details, see //build/config.mk.

Debugging

To print a log of system calls to stderr:

cosmocc -o hello hello.c
./hello --strace

To print a log of function calls to stderr:

cosmocc -o hello hello.c
./hello --ftrace

Both strace and ftrace use the unbreakable kprintf() facility, which is able to be sent to a file by setting an environment variable.

export KPRINTF_LOG=log
./hello --strace

GDB

Here's the recommended ~/.gdbinit config:

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 .dbg file under gdb. If you need to debug the `` file itself, then you can load the debug symbols independently as

gdb foo -ex 'add-symbol-file foo.dbg 0x401000'

Platform Notes

Shells

If you use zsh and have trouble running APE programs try sh -c ./prog or simply upgrade to zsh 5.9+ (since we patched it two years ago). The same is the case for Python subprocess, old versions of fish, etc.

Linux

Some Linux systems are configured to launch MZ executables under WINE. Other distros configure their stock installs so that APE programs will print "run-detectors: unable to find an interpreter". For example:

jart@ubuntu:~$ wget https://cosmo.zip/pub/cosmos/bin/dash
jart@ubuntu:~$ chmod +x dash
jart@ubuntu:~$ ./dash
run-detectors: unable to find an interpreter for ./dash

You can fix that by registering APE with binfmt_misc:

sudo wget -O /usr/bin/ape https://cosmo.zip/pub/cosmos/bin/ape-$(uname -m).elf
sudo chmod +x /usr/bin/ape
sudo sh -c "echo ':APE:M::MZqFpD::/usr/bin/ape:' >/proc/sys/fs/binfmt_misc/register"
sudo sh -c "echo ':APE-jart:M::jartsr::/usr/bin/ape:' >/proc/sys/fs/binfmt_misc/register"

You should be good now. APE will not only work, it'll launch executables 400µs faster now too. However if things still didn't work out, it's also possible to disable binfmt_misc as follows:

sudo sh -c 'echo -1 > /proc/sys/fs/binfmt_misc/cli'     # remove Ubuntu's MZ interpreter
sudo sh -c 'echo -1 > /proc/sys/fs/binfmt_misc/status'  # remove ALL binfmt_misc entries

WSL

It's normally unsafe to use APE in a WSL environment, because it tries to run MZ executables as WIN32 binaries within the WSL environment. In order to make it safe to use Cosmopolitan software on WSL, run this:

sudo sh -c "echo -1 > /proc/sys/fs/binfmt_misc/WSLInterop"

Discord Chatroom

The Cosmopolitan development team collaborates on the Redbean Discord server. You're welcome to join us! https://discord.gg/FwAVVu7eJ4

Support Vector

Platform Min Version Circa
AMD K8 2003
Intel Core 2006
Linux 2.6.18 2007
Windows 8 [1] 2012
Darwin (macOS) 23.1.0+ 2023
OpenBSD 7.3 or earlier 2023
FreeBSD 13 2020
NetBSD 9.2 2021

[1] See our vista branch 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 and Patreon. Your support is what makes this project possible. Thank you! We'd also like to give special thanks to the following groups and individuals:

For publicly sponsoring our work at the highest tier.

cosmopolitan (jart/cosmopolitan)

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21.4K ·GitHub
Cosmopolitan
What is this?Cosmopolitan Libc makes C/C++ a build-once run-anywhere language: you compile once and the same native binary runs on Linux, Mac, Windows, the BSDs and even BIOS - like Java, but with no interpreter or virtual machine.
Is it a library or a compiler toolchain?Both - it is a libc runtime plus cosmocc, a reconfigured stock GCC/Clang that outputs a POSIX-approved polyglot executable every supported OS runs natively, no VM or interpreter involved.
How do I get started building programs with it?Grab a cosmocc compiler release and compile your program with it - the README walks through a sample C program and its compile command. The output is the portable binary you ship.
What do I need installed before I can use it?For normal use, just the cosmocc toolchain. Building Cosmopolitan itself from source needs a modern GNU Make (Cosmopolitan Make is recommended), and the Makefile downloads cosmocc automatically.
Are there any gotchas when running the binaries?A few: zsh older than 5.9 fails to launch APE programs (use sh -c ./prog), some Linux distros print 'run-detectors' errors until you register APE with binfmt_misc, and WSL needs a workaround before APE is safe.
Which operating systems and how old hardware does it support?One binary covers Linux 2.6.18+, Windows 8+, macOS 23.1.0+, OpenBSD 7.3, FreeBSD 13 and NetBSD 9.2 on AMD K8 (2003) or Intel Core (2006) and newer, plus BIOS. A community vista branch adds Windows Vista/7.
What is APE?APE (Actually Portable Executable) is the polyglot file format cosmocc outputs - a single binary that Linux, macOS, Windows, the BSDs and BIOS all execute natively. Installing the systemwide APE Loader (sudo required) registers binfmt_misc on Linux and makes launches roughly 400μs faster.
What debugging tools does it ship with?Programs link strace and ftrace by default: strace logs system calls, ftrace logs function calls, both printed to stderr through the unbreakable kprintf(), which can also log to a file via an environment variable. GDB works via the recommended ~/.gdbinit and the .dbg file.
How small can the binaries get?A dedicated build mode produces binaries as small as 12kb, and you can additionally cut out support for other operating systems so the runtime behaves much more like Musl Libc.
Can it build existing open source projects?Yes - the cosmocc toolchain can build conventional projects that use autotools; the README says that strategy normally works, so you can point an existing configure-based build at cosmocc.
What are similar projects?vis, ReBarUEFI, libfyaml, tailcat, btop, TurboBench, spdlog, nnn
Which topics is it in?polyglot, zip, openbsd, freebsd, lightweight, containers, compiler, bsd, c, cpp, command-line, performance
Creator
jart
Size
318.3 MB
Stars
21.4K
Updated
CommitOct 13Release4.0.2Jan 06
Age
6y
Commits · 90 Days