- Use nullness checks when calling weakly linked functions. - Avoid typedef for reasons described in Linux Kernel style guide. - Avoid enum in in Windows headers. Earlier in Cosmo's history all one hundred files in libc/nt/enum/ used to be enums and it resulted in gigabytes of DWARF data almost as large as everything else in the codebase combined. - Bitfields aren't our friends. They have frequent ABI breakages, inconsistent arithmetic across compilers, and different endianness between cpus. Compiler authors also haven't invested much roi into making bit fields go fast so they produce poor assembly. - Use memccpy() instead of strncpy() or snprintf() for length-bounded copying of C strings. strncpy() is a misunderstood function and snprintf() is awesome but memccpy() deserves more love. |
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.github | ||
.vscode | ||
ape | ||
build | ||
dsp | ||
examples | ||
libc | ||
net | ||
test | ||
third_party | ||
tool | ||
usr/share | ||
.clang-format | ||
.gitignore | ||
.travis.yml | ||
CONTRIBUTING.md | ||
LICENSE | ||
Makefile | ||
README.md |
Cosmopolitan
Cosmopolitan Libc 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 blog post and cosmopolitan libc website. We also have API documentation.
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:
wget https://justine.lol/cosmopolitan/cosmopolitan-amalgamation-1.0.zip
unzip cosmopolitan-amalgamation-1.0.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 \
-o hello.com.dbg hello.c -fuse-ld=bfd -Wl,-T,ape.lds \
-include cosmopolitan.h crt.o ape.o cosmopolitan.a
objcopy -S -O binary hello.com.dbg hello.com
You now have a portable program. Please note that your APE binary will assimilate itself as a conventional resident of your platform after the first run, so it can be fast and efficient for subsequent executions.
./hello.com
bash -c './hello.com' # zsh/fish workaround (we upstreamed patches)
So if you intend to copy the binary to Windows or Mac then please do that before you run it, not after.
MacOS
If you're developing on MacOS you can install the GNU compiler collection for x86_64-elf via homebrew:
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 tutorial. It's needed because the ELF object format is what makes universal binaries possible.
Source Builds
Cosmopolitan can be compiled from source on any Linux distro. GNU make needs to be installed beforehand. This is a freestanding hermetic repository that bootstraps using a vendored static gcc9 executable. No further dependencies are required.
wget https://justine.lol/cosmopolitan/cosmopolitan-1.0.tar.gz
tar xf cosmopolitan-1.0.tar.gz # see releases page
cd cosmopolitan
make -j16
o//examples/hello.com
find o -name \*.com | xargs ls -rShal | less
Support Vector
Platform | Min Version | Circa |
---|---|---|
AMD | K8 Venus | 2005 |
Intel | Core | 2006 |
New Technology | Vista | 2006 |
GNU/Systemd | 2.6.18 | 2007 |
XNU's Not UNIX! | 15.6 | 2018 |
FreeBSD | 12 | 2018 |
OpenBSD | 6.4 | 2018 |
NetBSD | 9.1 | 2020 |
GNU Make | 3.80 | 2010 |