cce17461de
A closure's environment type — and the `=destroy`/`=copy`/`=sink` the compiler lifts for it — is minted by the BACKEND and exists in no module's semmed NIF. Grinding a corpus of closure programs against `nim c` as the oracle turned up three ways the per-module backend gets those wrong. `tests/closure` is now green under `--ic:on`, and `tests/iter` goes from 13 failures to 9. * **The env hook is emitted by nobody.** `emitsBodyInThisModule` walks up to the outermost enclosing routine to pick the TU that emits a body. For the env `=destroy` of a generic closure iterator defined in one module and instantiated in another, that walk lands on the module of the ORIGINAL generic — a module that never sees the instance — so the routine was emitted nowhere (`undefined reference to eqdestroy__c485__…`). A backend-minted routine has no owning module NIF at all: it is written into the `.t.bif` of every module that references it, re-homed there with `@bk`. Every referencing TU emits it now and the merge stage keeps one, like any other content-addressed definition. * **The `:up` link is stored without an increment.** `env.:up = enclosingEnv` has to go through `=copy` (with the cyclic incref) or the parent's refcount is one too low, and at teardown the two envs' mutually recursive `=destroy`s each believe they hold the last reference and recurse until the stack is gone — a SIGSEGV after the program's own output has already been printed (`tests/iter/tnestedclosures`, "Test 3"). Whether it becomes a `=copy` depends on the up-field type's hooks existing at injection time. Whole-program cgen got that for free: a LATER lifting pass creates them and it runs before any routine's injection. The per-module backend injects a routine right after lifting it (`lower`), long before the module's top level is transformed at all (`cg`) — so both up-field assignment sites create the ops themselves. * **Two backend hooks collide on one C name.** A backend-minted symbol is named `_c<itemId.item>`, a PER-PROCESS counter — fine while "nifc lifts, emits and compiles them in one run", which is what `mangleProcNameExt` assumed. But `lower` mints the env hooks of nested routines and `cg` mints those of the module's top level, and both land in the same translation unit: two unrelated `=destroy`s became one C function. `mangleProcNameExt` already makes an exception for hooks whose `disamb` is content-derived (`HookDisambBit`); `toNifSymName` now mirrors it, so the content-derived value survives the round trip instead of being overwritten by the loader. `InstanceDisambBit`/`HookDisambBit` move to `astdef` — `ast2nif` names symbols by them and cannot import `modulegraphs`. Two new metamorphic tests, both of which fail on the previous compiler: `tclosure_hooks` (generic closure iterator instantiated across modules) and `tclosure_nested_iter` (closure iterator nested in a closure iterator). `icFormatVersion` 37 -> 38 for the hook naming. `koch bootic` reaches its byte-identical fixed point; `tests/closure`, `tests/destructor` (3 known `--newruntime` failures), `tests/cpp` 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.