f3bdc6c5f2
`nim ic` was a command of its own, which made it the C backend only and cut it
off from everything the ordinary compile commands accept. `--ic:on` is a switch
on `nim c` / `nim cpp` / `nim objc` instead, so `-r`, `-d:release`,
`--exceptions:`, and a project-wide opt-in from `nim.cfg` / `config.nims` all
work. `nim ic` still resolves to the same driver; `koch bootic`, `koch ic` and
`testament --ic` now go through the switch.
The switch was already parsed into a `conf.ic` nobody read. It is now read in
`passCmd1` as well, because `nim.nim` has to decide whether this run is an IC
DRIVER before config loading (`ensureIcConfig` produces the precompiled config
the driver itself replays); when the switch comes from a config file instead,
`main.nim` produces it late.
**C++.** `tests/cpp` passes under `--ic:on`, matching its classic result. Four
fixes, three of them the shape of every "C++ needs the whole program" problem the
per-module backend has:
* The driver DECLARES each module's translation unit to nifmake without loading a
module, so it cannot ask `cgen.getCFile` — and it hardcoded `.nim.c`, so the
merge stage went looking for `.c.nif` next to the `.cpp.nif` the children had
written. `options.icCFileExt` mirrors the formula at backend granularity.
* C++ has no designated initializers, so the RTTI record is a bare variable that
`DatInit` fills field by field. A bare `TNimTypeV2 x;` is a tentative
definition — C's linker merges those, C++'s does not — so every TU that
demanded the type defined it ("multiple definition of NTIv2__…"). It now gets
the same extern-declaration + owned-`'d'`-definition split the C flavour has.
* `memberProcsPerType` / `initializersPerType` live only in the sem process, so
the backend emitted a struct WITHOUT its in-class member declarations and the
out-of-class definitions did not match ("no declaration matches
'void Doo::memberProc()'"). They are replayed from a new `(repcppmember …)`
log entry; `replayCppMember` re-derives the type from the routine's signature
exactly as `semCppMember` does, so no type key has to survive the round trip.
* Two follow-ons for members: `loc.snippet` is a CALL PATTERN (`#->salute(@)`),
and only `genMemberProcHeader` derives it — whole-program cgen got it for free
by generating the defining module first, but the per-module backend emits that
body in another process, leaving the caller with the mangled Nim name
(`loo->salute_u0__vireouyks1()`). And that pattern is not a linker name: every
`salute` member in every class mints the same one, so the merge stage handed
them all to one artifact and dropped the rest (undefined vtable at link).
Member definitions are keyed by their NIF name there instead.
`--run` is now dropped when re-invoking for the config artifact: the producer has
no output binary and `nim.nim`'s run step asserted on the empty `outFile`.
testament's `--ic` appends the switch rather than rewriting the compile verb, so
a test that overrides `cmd:` wholesale keeps its verb, and the C++ corpus is
covered too (it never was — the old rewrite only matched `nim c `).
`icFormatVersion` 36 -> 37 for the new log entry. `koch bootic` reaches its
byte-identical fixed point through the new entry point; `koch ic` passes;
`tests/ic`, `tests/destructor` (3 known `--newruntime` failures) and the classic
categories are unchanged.
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Nim
This repository contains the Nim compiler, Nim's stdlib, tools, and documentation. For more information about Nim, including downloads and documentation for the latest release, check out Nim's website or bleeding edge docs.
Community
- The forum - the best place to ask questions and to discuss Nim.
- #nim IRC Channel (Libera Chat) - a place to discuss Nim in real-time. Also where most development decisions get made.
- Discord - an additional place to discuss Nim in real-time. Most channels there are bridged to IRC.
- Gitter - an additional place to discuss Nim in real-time. There is a bridge between Gitter and the IRC channel.
- Matrix - the main room to discuss Nim in real-time. Matrix space contains a list of rooms, most of them are bridged to IRC.
- Telegram - an additional place to discuss Nim in real-time. There is the official Telegram channel. Not bridged to IRC.
- Stack Overflow - a popular Q/A site for programming related topics that includes posts about Nim.
- GitHub Wiki - Misc user-contributed content.
Compiling
The compiler currently officially supports the following platform and architecture combinations:
| Operating System | Architectures Supported |
|---|---|
| Windows (Windows XP or greater) | x86 and x86_64 |
| Linux (most distributions) | x86, x86_64, ppc64, and armv6l |
| Mac OS X (10.4 or greater) | x86, x86_64, ppc64, and Apple Silicon (ARM64) |
More platforms are supported, however, they are not tested regularly and they may not be as stable as the above-listed platforms.
Compiling the Nim compiler is quite straightforward if you follow these steps:
First, the C source of an older version of the Nim compiler is needed to
bootstrap the latest version because the Nim compiler itself is written in the
Nim programming language. Those C sources are available within the
nim-lang/csources_v3 repository.
Next, to build from source you will need:
- A C compiler such as
gcc6.x/later or an alternative such asclang,Visual C++orIntel C++. It is recommended to usegcc6.x or later. - Either
gitorwgetto download the needed source repositories. - The
build-essentialpackage when usinggccon Ubuntu (and likely other distros as well). - On Windows MinGW 4.3.0 (GCC 8.10) is the minimum recommended compiler.
- Nim hosts a known working MinGW distribution:
Windows Note: Cygwin and similar POSIX runtime environments are not supported.
Then, if you are on a *nix system or Windows, the following steps should compile
Nim from source using gcc, git, and the koch build tool.
Note: The following commands are for the development version of the compiler. For most users, installing the latest stable version is enough. Check out the installation instructions on the website to do so: https://nim-lang.org/install.html.
For package maintainers: see packaging guidelines.
First, get Nim from GitHub:
git clone https://github.com/nim-lang/Nim.git
cd Nim
Next, run the appropriate build shell script for your platform:
build_all.sh(Linux, Mac)build_all.bat(Windows)
Finally, once you have finished the build steps (on Windows, Mac, or Linux) you
should add the bin directory to your PATH.
See also bootstrapping the compiler.
See also reproducible builds.
Koch
koch is the build tool used to build various parts of Nim and to generate
documentation and the website, among other things. The koch tool can also
be used to run the Nim test suite.
Assuming that you added Nim's bin directory to your PATH, you may execute
the tests using ./koch tests. The tests take a while to run, but you
can run a subset of tests by specifying a category (for example
./koch tests cat async).
For more information on the koch build tool please see the documentation
within the doc/koch.md file.
Nimble
nimble is Nim's package manager. To learn more about it, see the
nim-lang/nimble repository.
Contributors
This project exists thanks to all the people who contribute.
Contributing
See detailed contributing guidelines. We welcome all contributions to Nim regardless of how small or large they are. Everything from spelling fixes to new modules to be included in the standard library are welcomed and appreciated. Before you start contributing, you should familiarize yourself with the following repository structure:
bin/,build/- these directories are empty, but are used when Nim is built.compiler/- the compiler source code. Also includes plugins withincompiler/plugins.nimsuggest- the nimsuggest tool that previously lived in thenim-lang/nimsuggestrepository.config/- the configuration for the compiler and documentation generator.doc/- the documentation files in reStructuredText format.lib/- the standard library, including:pure/- modules in the standard library written in pure Nim.impure/- modules in the standard library written in pure Nim with dependencies written in other languages.wrappers/- modules that wrap dependencies written in other languages.
tests/- contains categorized tests for the compiler and standard library.tools/- the tools includingniminst(mostly invoked viakoch).koch.nim- the tool used to bootstrap Nim, generate C sources, build the website, and generate the documentation.
If you are not familiar with making a pull request using GitHub and/or git, please read this guide.
Ideally, you should make sure that all tests pass before submitting a pull request.
However, if you are short on time, you can just run the tests specific to your
changes by only running the corresponding categories of tests. CI verifies
that all tests pass before allowing the pull request to be accepted, so only
running specific tests should be harmless.
Integration tests should go in tests/untestable.
If you're looking for ways to contribute, please look at our issue tracker.
There are always plenty of issues labeled Easy; these should
be a good starting point for an initial contribution to Nim.
You can also help with the development of Nim by making donations. Donations can be made using:
If you have any questions feel free to submit a question on the Nim forum, or via IRC on the #nim channel.
Backers
Thank you to all our backers! [Become a backer]
Sponsors
Support this project by becoming a sponsor. Your logo will show up here with a link to your website. [Become a sponsor]
You can also see a list of all our sponsors/backers from various payment services on the sponsors page of our website.
License
The compiler and the standard library are licensed under the MIT license, except for some modules which explicitly state otherwise. As a result, you may use any compatible license (essentially any license) for your own programs developed with Nim. You are explicitly permitted to develop commercial applications using Nim.
Please read the copying.txt file for more details.
Copyright © 2006-2026 Andreas Rumpf, all rights reserved.