Cosmopolitan v3.5.8 | Hacker News Reader

Cosmopolitan v3.5.8

github.com

103 pointssgammon24 comments

For those who don't want to click through to the main github description: "Cosmopolitan Libc makes C a build-anywhere run-anywhere language, like Java, except it doesn't need an interpreter or virtual machine. Instead, it reconfigures stock GCC and Clang to output a POSIX-approved polyglot format that runs natively on Linux + Mac + Windows + FreeBSD + OpenBSD + NetBSD + BIOS on AMD64 and ARM64 with the best possible performance. "

If this means the end of libc version errors, then count me in.

One question, is C++ supported?

Absolutely. Just download and extract cosmocc-3.5.8.zip and use its cosmoc++ command instead of g++. By default it'll use LLVM's libcxx STL although we've been working on our own versions of classes like std::set (called ctl::set) that are better. For example, just using ctl::vector alone might help your C++ code compile noticeably faster. https://github.com/jart/cosmopolitan/tree/master/ctl

> runs natively on Linux + Mac + Windows + FreeBSD + OpenBSD + NetBSD + BIOS on AMD64 and ARM64 with the best possible performance

Is it possible that a single binary will run on both AMD64 and ARM64?

As long as the subset of compatible instructions exist, it is likely possible to program a binary version of

    If you speak english, go to page 7.
    Si hablas español, ve a la página 25.

Note that the instructions don't have to be completely equivalent - all that's required is for some set of bytes to be arranged such that the same pattern will be interpreted by AMD64 as jump to X and by ARM64 as jump to Y.

Afterwards, it's all about segmenting the instructions in blocks, one for each OS/architecture.

That should've been in the title:

"Cosmopolitan Libc makes C a build-anywhere run-anywhere language"

Let the furious downvoting begin.

Lots of focus in other comments on pedantry. This looks like a cool project.

The README for this project still says "POSIX-approved" but there is nothing in POSIX that allows mixing commands and binary data in a shell script.

It does allow appending binary data to the end of a shell script* as long as it is guarded from being parsed as shell code by an exit, exec, etc. but that's it.

* https://pubs.opengroup.org/onlinepubs/9799919799/utilities/s...

Definitely not my area of either pedantry or expertise, but if I read this correctly:

> The input file can be of any type, but the initial portion of the file intended to be parsed according to the shell grammar […] shall consist of characters and shall not contain the NUL character.

Then POSIX doesn’t proscribe against appending binary data at all, it just requires that binary data appears after whatever portion of the file is intended to be parsed according to the grammar… there’s nothing stating that intention can’t apply to a zero characters.

> The shell shall not enforce any line length limits.

That seems to unambiguously allow a zero-length initial portion.

> If the input file consists solely of zero or more blank lines and comments, sh shall exit with a zero exit status.

And so does that, while also making an enormous loophole for any input file that is not zero or more blank lines.

In other words it seems to me on a quick reading that a decent rules-lawyer could drive a planet through that part of the spec, as written.

According to Justine herself[1], POSIX specifically changed their rules to allow this type of functionality[2].

The paragraph you linked to was part of it, but also this paragraph under RATIONALE[3]:

> Earlier versions of this standard required that input files to the shell be text files except that line lengths were unlimited. However, that was overly restrictive in relation to the fact that shells can parse a script without a trailing newline, and in relation to a common practice of concatenating a shell script ending with an exit or exec $command with a binary data payload to form a single-file self-extracting archive.

So Cosmopolitan indeed seems to be POSIX-approved as far as this behavior goes.

[1]: https://justine.lol/cosmo3/

[2]: https://austingroupbugs.net/view.php?id=1250

[3]: https://pubs.opengroup.org/onlinepubs/9799919799/utilities/s...

POSIX is one of those standards that don't really define anything at all. Microsoft POSIX subsystem is one of the nicest examples of something that lets you tick the POSIX checkbox but does almost nothing. One of the recent posix annoyances I stumbled upon was the clock_gettime where every platform has slightly different idea how the different CLOCKs are supposed to be interpreted :)

Personally I don't find the APE part of cosmopolitan that interesting, but their own POSIX API <https://justine.lol/cosmopolitan/functions.html> which also covers windows is interesting for sure. Zig's std also offers something similar, but perhaps not as good coverage. Getting fork, mmap, and poll work on windows is not small feat.

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