5799220c98
The `BNode` accessors had no oracle. The self-test in `bnode.nim` checks them against each other and against the raw token stream, which a uniformly wrong vocabulary satisfies — it passed 5.2M assertions on an off-by-two model. This adds the missing oracle and lets it drive the next migration step. `cgen.grindLockstep` (opt-in, `NIM_IC_BNODE_GRIND=1` on an `--ic:on` build) walks the `.bif` cursor and the materialised `PNode` for the SAME body side by side and requires `kind`, `len`, `info`, `flags`, the literal payloads, `sym` and `typ` to agree at every node of every routine body in the dependency closure. The `PNode` is the oracle, so it compares everything rather than what someone thought to check. It found two bugs, both silent: * `BNode.typ` answered `nil` for every bare `Symbol`. `ast.typ` does not: it falls back to `n.sym.typ` when the loader set `nfLazyType`, which it does for exactly that shape. The consequence is not less information but a DIFFERENT answer — `canRaise` asks `fn.typ.kind == tyProc` about a call's callee, so nil turns "this call can raise" into "it cannot" and drops the goto-exception check after the call. * `(ht . <sym>)` — an explicitly nil node type — made `n.typ` LOAD-ORDER DEPENDENT in the loader itself. `newSymNode` marks the node lazy only if the symbol was still an unloaded stub at that moment, so the same `.bif` node answered `sym.typ` or `nil` depending on what happened to touch that symbol first. Pinned to the lazy reading, so the answer is a property of the file rather than of the traversal order. With `typ` correct, the blocker recorded in `allPathsAsgnResult` is gone. `ast.canRaise`/`canRaiseConservative` cannot become `AnyNode` procs where they live — `BNode` is defined in `bnode.nim`, which imports `ast` — so their bodies move into templates that `bnode` instantiates for its own node type. One source of truth, no cycle, no second copy. `ccgcalls.canRaiseDisp` and `cgen.allPathsAsgnResult` follow. Adds the leaf accessors (`intVal`, `floatVal`, `strVal`, `ident`, `flags`) because nothing in `ccgexprs` can migrate without them, and `rawDesc` for diagnosing a disagreement in terms of what the token stream literally says. `compiler/bodynav.nim` replaces the `BodyScope` snapshot with a scope chain the traversal maintains — `openScope`/`closeScope`/`registerDefHere`, lookup falling through to the decoder — ported from Nimony's `typenav`. The scope becomes a product of the walk, so nothing is copied ahead of time and nothing can be stale. How much of a live problem the snapshot was is measured rather than assumed: `-d:icLocalSymStats` reports `localHit=0 fieldStub=2 miss=0 sdReg=5902 extractReg=45` over the stdlib closure, i.e. definitions register constantly and not one use ever resolved through the table, because `isLocalSym` is a hardwired `false`. The hazard was latent; this keeps it latent once that stops being true. Verified: 0 disagreements over the whole `--ic:on` closure with the walk driving the nav; deliberately breaking `intVal`, `flags` and the nav key each make the grinder fire on the first bodies it reaches, so the clean run is not vacuous; the default path emits 215/215 byte-identical `.c` against the pre-change compiler and does not compile `bodynav` at all; `tests/ic` 39/39. Co-Authored-By: Claude Opus 5 <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_01XEF7FJvUkGKvG9LSGuEaNR
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.