a92427bf27
This function is sometimes used to assume a canonical representation of a path. However, when the `Path` referred to `root_dir` itself, this function previously resolved `sub_path` to ".", which is incorrect; per doc comments, it should set `sub_path` to "". This fix ultimately didn't solve what I was trying to solve, though I'm still PRing it, because it's still *correct*. The background to this commit is quite interesting and worth briefly discussing. I originally worked on this to try and fix a bug in the build system, where if the root package (i.e. the one you `zig build`) depends on package X which itself depends back on the root package (through a `.path` dependency), invalid dependency modules are generated. I hit this case working on ziglang/translate-c, which wants to depend on "examples" (similar to the Zig compiler's "standalone" test cases) which themselves depend back on the translate-c package. However, after this patch just turned that error into another, I realised that this case simply cannot work, because `std.Build` needs to eagerly execute build scripts at `dependency` calls to learn which artifacts, modules, etc, exist. ...at least, that's how the build system is currently designed. One can imagine a world where `dependency` sort of "queues" the call, `artifact` and `module` etc just pretend that the thing exists, and all configure functions are called non-recursively by the runner. The downside is that it becomes impossible to query state set by a dependency's configure script. For instance, if a dependency exposes an artifact, it would become impossible to get that artifact's resolved target in the configure phase. However, as well as allowing recursive package imports (which are certainly kinda nifty), it would also make lazy dependencies far more useful! Right now, lazy dependencies only really work if you use options (`std.Build.option`) to block their usage, since any call to `lazyDependency` causes the dependency to be fetched. However, if we made this change, lazy dependencies could be made far more versatile by only fetching them *if the final step plan requires them*. I'm not 100% sure if this is a good idea or not, but I might open an issue for it soon.
A general-purpose programming language and toolchain for maintaining robust, optimal, and reusable software.
Documentation
If you are looking at this README file in a source tree, please refer to the Release Notes, Language Reference, or Standard Library Documentation corresponding to the version of Zig that you are using by following the appropriate link on the download page.
Otherwise, you're looking at a release of Zig, so you can find the language
reference at doc/langref.html, and the standard library documentation by
running zig std, which will open a browser tab.
Installation
A Zig installation is composed of two things:
- The Zig executable
- The lib/ directory
At runtime, the executable searches up the file system for the lib/ directory, relative to itself:
- lib/
- lib/zig/
- ../lib/
- ../lib/zig/
- (and so on)
In other words, you can unpack a release of Zig anywhere, and then begin
using it immediately. There is no need to install it globally, although this
mechanism supports that use case too (i.e. /usr/bin/zig and /usr/lib/zig/).
Building from Source
Ensure you have the required dependencies:
- CMake >= 3.15
- System C/C++ Toolchain
- LLVM, Clang, LLD development libraries == 20.x
Then it is the standard CMake build process:
mkdir build
cd build
cmake ..
make install
For more options, tips, and troubleshooting, please see the Building Zig From Source page on the wiki.
Building from Source without LLVM
In this case, the only system dependency is a C compiler.
cc -o bootstrap bootstrap.c
./bootstrap
This produces a zig2 executable in the current working directory. This is a
"stage2" build of the compiler,
without LLVM extensions, and is
therefore lacking these features:
- Release mode optimizations
- aarch64 machine code backend
- @cImport
- zig translate-c
- Ability to compile assembly files
- Some ELF linking features
- Most COFF/PE linking features
- Some WebAssembly linking features
- Ability to create import libs from def files
- Ability to create static archives from object files
- Ability to compile C, C++, Objective-C, and Objective-C++ files
However, a compiler built this way does provide a C backend, which may be useful for creating system packages of Zig projects using the system C toolchain. In this case, LLVM is not needed!
Furthermore, a compiler built this way provides an LLVM backend that produces bitcode files, which may be compiled into object files via a system Clang package. This can be used to produce system packages of Zig applications without the Zig package dependency on LLVM.
Contributing
Zig is Free and Open Source Software. We welcome bug reports and patches from everyone. However, keep in mind that Zig governance is BDFN (Benevolent Dictator For Now) which means that Andrew Kelley has final say on the design and implementation of everything.
One of the best ways you can contribute to Zig is to start using it for an open-source personal project.
This leads to discovering bugs and helps flesh out use cases, which lead to further design iterations of Zig. Importantly, each issue found this way comes with real world motivations, making it straightforward to explain the reasoning behind proposals and feature requests.
You will be taken much more seriously on the issue tracker if you have a personal project that uses Zig.
The issue label Contributor Friendly exists to help you find issues that are limited in scope and/or knowledge of Zig internals.
Please note that issues labeled Proposal but do not also have the Accepted label are still under consideration, and efforts to implement such a proposal have a high risk of being wasted. If you are interested in a proposal which is still under consideration, please express your interest in the issue tracker, providing extra insights and considerations that others have not yet expressed. The most highly regarded argument in such a discussion is a real world use case.
For more tips, please see the Contributing page on the wiki.
Community
The Zig community is decentralized. Anyone is free to start and maintain their own space for Zig users to gather. There is no concept of "official" or "unofficial". Each gathering place has its own moderators and rules. Users are encouraged to be aware of the social structures of the spaces they inhabit, and work purposefully to facilitate spaces that align with their values.
Please see the Community wiki page for a public listing of social spaces.