# Redox C Library (relibc)
relibc is a portable C standard library written in Rust and is under heavy development, this library contain the following items:
- C, Linux, BSD functions and extensions
- POSIX compatibility layer
- Interfaces for system components
The motivation for this project is twofold: Reduce issues that the Redox developers were having with [newlib](https://sourceware.org/newlib/), and create a more stable and safe alternative to C standard libraries written in C. It is mainly designed to be used under Redox, as an alternative to newlib, but it also supports Linux via the [sc](https://crates.io/crates/sc) crate.
Currently Redox and Linux are supported.
## `redox-rt`
`redox-rt` is a runtime library that provides much of the code that enables POSIX on Redox, like `fork`, `exec`, signal handling, etc.
Relibc uses it as backend in `src/platform/redox`, and it's intended to eventually be usable independently, without relibc.
## Repository Layout
- `include` - Header files (mostly macros and variadic functions `cbindgen` can't generate)
- `src` - Source files
- `src/c` - C code
- `src/crt0` - Runtime code
- `src/crti` - Runtime code
- `src/crtn` - Runtime code
- `src/header` - Header files implementation
- `src/header/*` - Each folder has a `cbindgen.toml` file, it generates a C-to-Rust interface and header files
- `src/ld_so` - Dynamic loader code
- `src/platform` - Platform-specific and common code
- `src/platform/redox` - Redox-specific code
- `src/platform/linux` - Linux-specific code
- `src/pthread` - pthread implementation
- `src/sync` - Synchronization primitives
- `tests` - C tests (each MR needs to give success in all of them)
## Download the sources
To download the relibc sources run the following command:
```sh
git clone --recursive https://gitlab.redox-os.org/redox-os/relibc
```
## Build Instructions
To build relibc out of the Redox build system, do the following steps:
### Dependencies
- Install `cbindgen`
```sh
cargo install cbindgen
```
#### Install the `expect` tool
- Debian, Ubuntu and PopOS:
```sh
sudo apt install expect
```
- Fedora:
```sh
sudo dnf install expect
```
- Arch Linux:
```sh
sudo pacman -S expect
```
### Build Relibc
To build the relibc library objects, run the following command:
```sh
make all
```
- Clean old library objects and tests
```sh
make clean
```
## Build relibc inside the Redox build system
Inside of your Redox build system, run:
```sh
make prefix
```
If you need to rebuild `relibc` for testing a Cookbook recipe, run:
```sh
touch relibc
make prefix r.recipe-name
```
Touching (changing the "last modified time" of) the `relibc` folder is needed to trigger recompilation for `make prefix`. Replace `recipe-name` with your desired recipe name.
Note: Do not edit `relibc` inside `prefix` folder! Do your work on `relibc` folder directly inside your Redox build system instead.
## Tests
This section explain how to build and run the tests.
### Build
To build the tests run `make all` on the `tests` folder, it will store the executables at `tests/bins_static`
If you did changes to your tests, run `make clean all` to rebuild the executables.
### Redox OS Testing
To test on Redox do the following steps:
- Add the `relibc-tests` recipe on your filesystem configuration at `config/your-cpu/your-config.toml` (generally `desktop.toml`)
- Run the following commands to rebuild relibc with your changes, update the `relibc-tests` recipe and update your QEMU image:
```sh
touch relibc
```
```sh
make prefix cr.relibc-tests image
```
- Run the tests
```sh
/usr/share/relibc-tests/bins_static/test-name
```
### Linux Testing
Run `make test` on the relibc directory.
If you want to run one test, run the following command:
```sh
tests/bins_static/test-name
```
## Issues
#### I'm building for my own platform which I run, and am getting `x86_64-linux-gnu-ar: command not found` (or similar)
The Makefile expects GNU compiler tools prefixed with the platform specifier, as would be present when you installed a cross compiler. Since you are building for your own platform, some Linux distributions (like Manjaro) don't install/symlink the prefixed executables.
An easy fix would be to replace the corresponding lines in the Makefile, e.g.
```diff
ifeq ($(TARGET),x86_64-unknown-linux-gnu)
export CC=x86_64-linux-gnu-gcc
- export LD=x86_64-linux-gnu-ld
- export AR=x86_64-linux-gnu-ar
+ export LD=ld
+ export AR=ar
export OBJCOPY=x86_64-linux-gnu-objcopy
endif
```
## Contributing
Before starting to contribute, read [this](CONTRIBUTING.md) document.
## Supported OSes
- Redox OS
- Linux
## Supported architectures
- i586 (Intel/AMD)
- x86_64 (Intel/AMD)
- aarch64 (ARM64)
- riscv64gc (RISC-V)
## Funding - _Unix-style Signals and Process Management_
This project is funded through [NGI Zero Core](https://nlnet.nl/core), a fund established by [NLnet](https://nlnet.nl) with financial support from the European Commission's [Next Generation Internet](https://ngi.eu) program. Learn more at the [NLnet project page](https://nlnet.nl/project/RedoxOS-Signals).
[
](https://nlnet.nl)
[
](https://nlnet.nl/core)