VFSForGit VS llvm-project

It's not only Windows that uses Git at Microsoft, but Sharepoint and Office (which includes the on-prem version of SharePoint). In terms of repo size Windows and Office are similar. I was part of the team that migrated Sharepoint from a Perforce clone to Git and helped build the tooling to allow Office to move as well. VFS for Git [1] and Scalar [2] are really good pieces of software.

[1] - https://github.com/microsoft/VFSForGit

[2] - https://github.com/microsoft/scalar

Congratulations! That means you basically figured out how the clone procedure works and found a way to do so just in a partial way (also in an unsafe way). But it is a cool idea, nonetheless.

Also check out the Scalar [1] project and its predecessor, GVFS [2], both from Microsoft to manage their monorepo via a VFS layer.

[1]: https://github.com/microsoft/scalar

[2]: https://github.com/microsoft/VFSForGit

VFS for Git is still Open Source: https://github.com/microsoft/VFSForGit

Microsoft's blog posts have indicated a move to use something as close to off-the-shelf git as possible, though. They say they've stopped using VFS much and are instead more often relying on sparse checkouts. They've upstreamed a lot of patches into git itself, and maintain their own git fork but the fork distance is generally shrinking as those patches upstream.

https://github.com/microsoft/VFSForGit

better than it used to, with the caveat that git in particular is not and has never claimed to be good at versioning blobs.

Oh dear you're not going to like this.

It’s virtualised file system: https://github.com/microsoft/VFSForGit, only downloads what you actually use. Same thing in every large company, but different implementations.

This is where something like VFSForGit[0] helps out. Instead of cloning the entire repo, it creates a virtual file system and fetches objects on demand. MSFT uses it internally for the Windows source tree (which now exceeds 300GB).

[0]: https://github.com/microsoft/VFSForGit

There's also a performance consideration. Not excluding /bin/ or /obj/ folders means dependencies are being tracked as well, and sometimes dependencies themselves are bigger than the program's source code itself. This is commonly the case with node projects, as the node_modules folder can balloon to hundreds of megabytes. They should never be tracked in git due to the nature of how git's internal database works. For e.g. if you delete a dependency because it's no longer needed, you can never fully reclaim that disk space (at least for the master branch) as git will need to keep the binary data stored in its internal tracking database because a previous commit in the master branch has captured the data. As you make more branches, git needs to store the data required to reconstruct your repo to a different state when you switch branches. When a branch has changes measured in the kilobytes, check out is very manageable, but when the differences balloon to many MBs due to the presence of heavy binary files, then checkout between different branches/commits can get very slow. Though, this happens anyway when source code data eventually reaches a certain threshold, beyond the hundreds of megabytes, it's made unnecessarily worse by including any binary files. It's one of the reasons Microsoft created VFS for git: https://github.com/microsoft/VFSForGit.

You mean like VFSforGit? Or the successor for that called Scalar? This has been a solved problem. Microsoft moved their entire Windows codebase to git. There have been a ton of huge improvements to performance as a result of that. And the above two plugins are easily better ways to deal with what you're referring to without resulting to dead tech.

'Computer Architeture: A Quantitative Apporach" and/or more specific design types (mips, arm, etc) can be found under the Morgan Kaufmann Series in Computer Architeture and Design.

"Getting Started with LLVM Core Libraries: Get to Grips With Llvm Essentials and Use the Core Libraries to Build Advanced Tools "

"The Architecture of Open Source Applications (Volume 1) : LLVM" https://aosabook.org/en/v1/llvm.html

"Tourist Guide to LLVM source code" : https://blog.regehr.org/archives/1453

llvm home page : https://llvm.org/

llvm tutorial : https://llvm.org/docs/tutorial/

llvm reference : https://llvm.org/docs/LangRef.html

learn by examples : C source code to 'llvm' bitcode : https://stackoverflow.com/questions/9148890/how-to-make-clan...

See

https://github.com/llvm/llvm-project/issues/88344

https://fortran-lang.discourse.group/t/flang-new-how-to-forc...

You can never mistake type_declaration with an identifier, otherwise the program will not work. Aside from that constraint, you are free to name them whatever you like, there is no one standard, and each parser has it own naming conventions, unless you are planning to use something like LLVM. If you are interested, you can see examples of naming in different language parsers in the AST Explorer.

> There is one way to make the LLVM JIT compiler more usable, but I fear it’s going to take years to be implemented: being able to cache and reuse compiled queries.

Actually, it's implemented in LLVM for years :) https://github.com/llvm/llvm-project/commit/a98546ebcd2a692e...

> It's true, this was a CVE in Rust and not a CVE in C++, but only because C++ doesn't regard the issue as a problem at all. The problem definitely exists in C++, but it's not acknowledged as a problem, let alone fixed.

Can you find a link that substantiates your claim? You're throwing out some heavy accusations here that don't seem to match reality at all.

Case in point, this was fixed in both major C++ libraries:

https://github.com/gcc-mirror/gcc/commit/ebf6175464768983a2d...

https://github.com/llvm/llvm-project/commit/4f67a909902d8ab9...

So what C++ community refused to regard this as an issue and refused to fix it? Where is your supporting evidence for your claims?

For everyone else looking for the magic in this almost 7k lines monster, look at line 6610 [1].

[1] https://github.com/llvm/llvm-project/blob/8ec28af8eaff5acd0d...

Through value tracking. It's actually LLVM that does this, GCC probably does it as well, so in theory explicit bounds checks in regular C code would also be removed by the compiler.

How it works exactly I don't know, and apparently it's so complex that it requires over 9000 lines of C++ to express:

https://github.com/llvm/llvm-project/blob/main/llvm/lib/Anal...

https://github.com/llvm/llvm-project/blob/main/flang/docs/F2...