fossa-cli VS QEMU

> where we provide lockfiles that are individually valid

Providing lockfiles is a really interesting idea! That certainly solves the "we need your non-deterministic build tool to reproduce an exact build that we found" problem.

We haven't explored this route yet because a lot of our customers use tools that don't support lockfiles (e.g. Maven - Java in general has a lot of legacy stuff).

If you want to build off of our work, our dependency analysis bit is open source: https://github.com/fossas/fossa-cli

FOSSA | Software Engineers (Mid, Sr., Staff), PMs (Mid, Sr.) | USA, Canada, Remote (able to work ~US time zone hours)| Full-Time

FOSSA builds developer tools to help engineering teams manage their open source. We help enterprise customers discover legal (licensing and copyright) and security (vulnerabilities) risks in their dependencies, provide tooling for them to catch these issues in CI, and automate the tedium around policy enforcement and report generation. As companies adopt more open source, their engineering teams get bogged down by more distractions around compliance and security. We help automate away those distractions.

We build an open-source CLI tool (https://github.com/fossas/fossa-cli) that integrates with compilers and build systems to extract dependency and build information; a backend distributed system for analyzing dependency metadata; and a web application with a policy, reporting, and enforcement engine.

Tech we use includes:

The project I'm trying to build is open source (https://github.com/fossas/fossa-cli). When I got this new system set up, I ran the instructions on our HACKING.md page and immediately tried to build. This failed because I didn't have `llvm` installed, so I `brew install llvm`'d, symlinked into `$PATH`, and tried again. This failed due to: ``` install_name_tool: error: unsupported load command (cmd=0x80000034) `install_name_tool' failed in phase `Install Name Tool'. (Exit code: 1)

My most-wanted QEMU feature: https://github.com/qemu/qemu/commit/a2260983c6553

Using `gic-version=3` on macOS you can now use more than 8 cores on ARM chips.

A better solution is just to write a plain ass shell script that tests if various C snippets compile.

https://github.com/oilshell/oil/blob/master/configure

https://github.com/oilshell/oil/blob/master/build/detect-pwe...

Not an unholy mix of m4, shell, and C, all in the same file.

---

These are the same style as a the configure scripts that Fabrice Bellard wrote for tcc and QEMU.

They are plain ass shell scripts, because he actually understands the code he writes.

https://github.com/qemu/qemu/blob/master/configure

https://github.com/TinyCC/tinycc/blob/mob/configure

OCaml’s configure script is also “normal”.

You don’t have to copy and paste thousands of lines of GNU stuff that you don’t understand.

(copy of lobste.rs comment)

Related:

A fast Pascal (Delphi) WebAssembly interpreter:

https://github.com/marat1961/wasm

WASM-4:

https://github.com/aduros/wasm4

Curated list of awesome things regarding WebAssembly (wasm) ecosystem:

https://github.com/mbasso/awesome-wasm

Also, it would be nice if there was a WASM (soft) CPU for QEMU, which (if it existed!) would go here:

https://github.com/qemu/qemu/tree/master/target

> architectural registers are always updated

In tiny code, the guest registers (global TCG variables) are stored in the host's registers until you either call an helper which can access the CPU state or you return (`git grep la_global_sync`). This is the reason why QEMU is not so terribly slow.

But after a check, this also happens when you access the guest memory address space! https://github.com/qemu/qemu/blob/master/include/tcg/tcg-opc... (TCG_OPF_SIDE_EFFECTS is what matters)

But still, in the end, it's the same problem. What QEMU does, can be done in LLVM too. You could probably be more efficient in LLVM by using the exception handling mechanism (invoke and friends) to only serialize back to memory when there's an actual exception, at the cost of higher register pressure. More or less what we do here: https://rev.ng/downloads/bar-2019-paper.pdf

Um, in case you don't know, UTM (based on QEMU) is out for quite a while.

Some of these tools include Oracle VM VirtualBox (that I've used since before the acquisition of Sun Microsystems by Oracle), VMWare Workstation Player, and QEMU, but last year, I found out about Multipass.

For C/C++ projects that use meson as the build system, there is an excellent way to manage dependencies:

https://mesonbuild.com/Wrapdb-projects.html

https://mesonbuild.com/Wrap-dependency-system-manual.html

meson will download and build the libraries automatically and give you a variable which you pass as a regular dependency into the built target:

https://github.com/qemu/qemu/tree/005ad32358f12fe9313a4a0191...

https://github.com/harfbuzz/harfbuzz/tree/main/subprojects

https://github.com/harfbuzz/harfbuzz/blob/37457412b3212463c5...

Or, if you're using proper operating systems, they're managed by the usual package manager, just like everything else.

For all the users of the Linux platform, QEMU is the VM that you should go for. This software comes without any price tag and works as an emulator of various machines with utmost ease and completion; the software uses dynamic translations to emulate hardware peripherals and enhances its overall performance. If you are using QEMU as a virtualizer, then it will function exactly like the host system (provided you have the right set of hardware).

In this tutorial, we set up macOS and Windows virtual machines on UTM, a macOS application that provides a GUI wrapper for QEMU, a powerful open-source emulator and virtualizer. UTM allows you to easily manage and run virtual machines without memorizing complex commands. It also has special handling for macOS, making it simpler to install compared to other virtual machine software.