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anthropics
claudes-c-compiler
Rust2026–2026
anthropics / claudes-c-compiler

claudes-c-compiler

Claude Opus 4.6 wrote a dependency-free C compiler in Rust, with backends targeting x86 (64- and 32-bit), ARM, and RISC-V, capable of compiling a booting Linux kernel.

27Distinct people
30Mentions
1Explicit recommenders
2.8KGitHub stars
REPOSITORY AT A GLANCE

What to know before exploring

What it is

Claude Opus 4.6 wrote a dependency-free C compiler in Rust, with backends targeting x86 (64- and 32-bit), ARM, and RISC-V, capable of compiling a booting Linux kernel.

GitHub

Where it is used

No documented product use was verified in the last source check.

What people are saying

Between all of the "banter" (which is from more than just the anti-AI folks) you may not have caught I was one of the first 10 comments on that very issue 3 days ago…

zamadatix used a recommendation phrase. One indexed comment matches. This is a phrase match, not a verdict.

No classified warning is attached to this page. Read the discussions before treating silence as approval.

Also in these discussions

Mentioned in the same Hacker News threads. That is not proof they are substitutes.

This week on Hacker News

Nov 8–Nov 15 UTC · Direct repository links and separately labeled related project stories. Indexed through 11/15/2026, 9:01:12 PM UTC.

No direct repository links were found in the indexed HN discussions over the past seven days. Older discussions are available below.

Mentions over time

HN mentions by month30 dated mentions

Observed mentions: 2026-02-05 19:23:04 UTC to 2026-09-19 11:28:56 UTC.

051015202026-02-01 00:00:00 UTC to 2026-03-01 00:00:00 UTC (exclusive): 21 mentions; 3 submissions, 18 commentsFeb 20262026-03-01 00:00:00 UTC to 2026-04-01 00:00:00 UTC (exclusive): 2 mentions; 0 submissions, 2 comments2026-04-01 00:00:00 UTC to 2026-05-01 00:00:00 UTC (exclusive): 0 mentions; 0 submissions, 0 comments2026-05-01 00:00:00 UTC to 2026-06-01 00:00:00 UTC (exclusive): 1 mentions; 0 submissions, 1 commentsMay 20262026-06-01 00:00:00 UTC to 2026-07-01 00:00:00 UTC (exclusive): 3 mentions; 0 submissions, 3 comments2026-07-01 00:00:00 UTC to 2026-08-01 00:00:00 UTC (exclusive): 2 mentions; 0 submissions, 2 comments2026-08-01 00:00:00 UTC to 2026-09-01 00:00:00 UTC (exclusive): 0 mentions; 0 submissions, 0 comments2026-09-01 00:00:00 UTC to 2026-10-01 00:00:00 UTC (exclusive): 1 mentions; 0 submissions, 1 commentsSep 2026

Counts come from the repository’s dated source evidence. Index cutoff: 2026-11-02 08:16:59 UTC.

View mention counts and date ranges
UTC ranges include their start and exclude their end. Select a period to filter the source evidence.
PeriodStart (UTC)End (exclusive, UTC)MentionsSubmissionsComments
Feb 20262026-02-01 00:00:00 UTC2026-03-01 00:00:00 UTC21318
Mar 20262026-03-01 00:00:00 UTC2026-04-01 00:00:00 UTC202
Apr 20262026-04-01 00:00:00 UTC2026-05-01 00:00:00 UTC000
May 20262026-05-01 00:00:00 UTC2026-06-01 00:00:00 UTC101
Jun 20262026-06-01 00:00:00 UTC2026-07-01 00:00:00 UTC303
Jul 20262026-07-01 00:00:00 UTC2026-08-01 00:00:00 UTC202
Aug 20262026-08-01 00:00:00 UTC2026-09-01 00:00:00 UTC000
Sep 20262026-09-01 00:00:00 UTC2026-10-01 00:00:00 UTC101

What Hacker News says

21 sources
Didn't see people mention this in the initial discussion, but despite not having access to internet, the agents actually had access to the source code of GNU binutils (has assembler, linker and readelf), and many C compilers (SDCC, PCC, chibicc, cproc, etc) in their working directory [1]. These are supposed to test compilation, but there's no way to prove that Claude didn't get crucial info from these projects. I also found the compiler to have uncanny resemblance with chibicc. With 30-ish edge cases[2] yielding the same behavior, it's hard to believe there's no influence of chibicc in its algorithms. [1] https://github.com/anthropics/claudes-c-compiler/blob/6f1b99... [2] https://github.com/anthropics/claudes-c-compiler/issues/232
In OK, so Anthropic's AI built a C compiler. That don't impress me much
> This was the equivalent of a "weekend project", and it's amazing I mean, $20k in tokens, plus the supervision by the author to keep things running, plus the number of people that got involved according to the article... doesn't look like "a weekend project". > Building a C compiler which can correctly compile (maybe not link) the modern linux kernel is damn hard. Is it correctly compiling it? Several people have pointed out that the compiler will not emit errors for clearly invalid code. What code is it actually generating? > Building a C compiler which can correctly compile sqlite and pass the test suite at any speed is damn hard. It's even harder to have a C compiler that can correctly compile SQLite and pass the test suite but then the SQLite binary itself fails to execute certain queries (see https://github.com/anthropics/claudes-c
Read the rest
-compiler/issues/74). > which, in comparison with a correct modern C compiler, is far less performance critical, complex, broad, etc. That code might be less complex for us, but more complex for an LLM if it has to deal with lots of domain-specific context and without a test suite that has been developed for 40 years. Also, if the end result of the LLM has the same problem that Anthropic concedes here, which is that the project is so fragile that bug fixes or improvements are really hard/almost impossible, that still matters. > it really seems that the complaints here aren't about the LLMs themselves, or the agents, but about what people/organizations do with them, which is then a complaint about people, but not the technology It's a discussion about what the LLMs can actually do and how people represent those achievements. We're point out that LLMs, without human supervision, generate bad code, code that's hard to change, with modifications specifically made to address failing tests without challenging the underlying assumptions, code that's inconsistent and hard to understand even for the LLMs. But some people are taking whatever the LLM outputs at face value, and then claiming some capabilities of the models that are not really there. They're still not viable for using without human supervision, and because the AI labs are focusing on synthetic benchmarks, they're creating models that are better at pushing through crappy code to achieve a goal.
In Claude’s C Compiler vs. GCC
Something that bothers me here is that Anthropic claimed in their blog post that the Linux kernel could boot on x86 - is this not actually true then? They just made that part up? It seemed pretty unambiguous to me from the blog post that they were saying the kernel could boot on all three arch's, but clearly that's not true unless they did some serious hand-waving with kernel config options. Looking closer in the repo they only show a claimed Linux boot for RISC-V, so... [0]: https://www.anthropic.com/engineering/building-c-compiler - "build a bootable Linux 6.9 on x86, ARM, and RISC-V." [1]: https://github.com/anthropics/claudes-c-compiler/blob/main/B... - only shows a test of RISC-V
In Claude’s C Compiler vs. GCC
zamadatix·Feb 9, 2026Recommendation phrase
Between all of the "banter" (which is from more than just the anti-AI folks) you may not have caught I was one of the first 10 comments on that very issue 3 days ago https://github.com/anthropics/claudes-c-compiler/issues/1#is.... Not to imply there are no issues or it's a good compiler, the README.md says as much, but I found in practice you can get to CCC compiling a version of the Linux kernel in the amount of time it takes to go through that thread about hello world. Of course - you do you, not everyone is the same. If that kind of discussion piques your interest or feels easier to consume then there is plenty more to be found there. At least that guy's bot spamming 75% of the issues board has closed them all now (though the comments are still there in responses other issues) so it's a little cleaner. N.b. for anyone seeing "root@main
Read the rest
" in the above link - that's just an ephemeral rootless container instance on a dev VM host from a template named "main" I spun up to mess with CCC. I.e. "don't let the prompt imply I recommend using actual root on your actual main box to do much of anything, let alone run random projects from GitHub" :).
In CCC (Claude's C Compiler) on Compiler Explorer
The comments at [1] are a bit _too_ trollish for me, but they _do_ showcase that this compiler is far too lenient on what it accepts to the point where I'd hesitate to call it ... a C compiler (This [2] comment in particular is pretty damning). Still, an impressive achievement nonetheless, but there's a lot of nuance under the surface. [1] https://github.com/anthropics/claudes-c-compiler/issues/1 [2] https://github.com/anthropics/claudes-c-compiler/issues/1#is...
In We tasked Opus 4.6 using agent teams to build a C Compiler

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