ikos VS codeql

I beg to differ: there are a few tools which are comparable.

Frama-C (https://www.frama-c.com) is an open source framework that has, among its analyzers, one based on abstract interpretation (https://www.frama-c.com/fc-plugins/eva.html) that is very similar in spirit to Astree.

MOPSA (https://mopsa.lip6.fr) is another open-source project (albeit more recent, and in a more "academic" stage) that also provides abstract interpretation to analyze C programs for flaws.

NASA also released IKOS (https://github.com/NASA-SW-VnV/ikos), on the same vein.

Of course they lack the polish of a product which costs tens of thousands of euros per license, but they are open source, and their purpose is the same: to ensure code safety via formal methods, in particular abstract interpretation.

It is possible to get these tools to analyze some code and generate no complaints, which ensures absence of several kinds of problems, such as memory safety issues.

Then again, it's hard to know exactly how much they differ from Astree, since you need a license to compare them, and I don't even know if you are allowed to publish such comparisons.

I've been playing around with running IKOS (https://github.com/NASA-SW-VnV/ikos), it sounds very cool but doesn't seem to be super well maintained. I've managed to compile my project to llvm bit-code and run the IKSO on it, but the actual analysis seems to be buggy. There are open issues for the problems I encountered, but the make the analysis pretty useless (it thinks most functions are unreachable).

> https://www.absint.com/astree/index.htm

This looks interesting. It's based on abstract interpretation which is more or less the most powerful approach for imperative code available. (Because the way it works it's likely slow as hell though, I guess).

But it's closed source. One of this kind of products where you need to asks for the price… I think we all know what this means: It'll be laughably expensive.

I don't see any offer for OpenSource projects frankly.

> https://github.com/NASA-SW-VnV/ikos

Also abstract interpretation based. Looks less polished than the first one at first glance.

It's under some questionable license. According to OSI it's OpenSource. According to the FSF it's not. (The FSF argument sounds strong. They're right in my opinion. This NASA license does not look like OpenSource).

But an OpenSource project could use it for free I assume.

> https://github.com/static-analysis-engineering/CodeHawk-C

Much more constrained in scope than the other ones. But looks a little bit "too academic" imho: Uses its own C parser and such.

At least it's OpenSource under MIT license.

Thanks for the links either way! Good to know about some tools in case one would need them at some point.

> I have planned to try using them on OpenZFS for a while, but I am still busy reviewing and fixing reports made by conventional static analyzers.

Stupid question about usual C development practices (as I don't have much contact with that):

Aren't analyzers today part of the build pipeline form the get go? Especially as C is known to be full of booby traps.

Imho it shouldn't be even possible to push anything that has issues discovered by tools.

This should be the lowest barrier as most code analyzers are at most able to spot quite obvious problems (the commercial one above is likely an exception to this "rule"). When even the usual "stupid analyzer" sees issues than the code is very likely in a very bad shape.

Adding such tools later on in the development is like activating warnings post factum: You'll get drowned in issues.

Especially in such critical domains as file-systems I would actually expect that the developers are using "the best tools money can buy" (or at least the best OpenSource tools available).

"Still fixing bugs found by some code analyzer" doesn't sound like someone should have much trust with their data in something like ZFS, to be honest… The statement sounds actually quite scary to me.

They have very unusual license which I have never seen before: https://github.com/NASA-SW-VnV/ikos/blob/master/LICENSE.txt

Is anyone familiar with it? Is it OSI certified? (it's not on the OSI's site).

Yeah there are tools that require adding contracts as comments. But again, there are also friction-less tools that don't require any changes (for example a NASA one).

apologies if this should be a discussion/issue/whatever but:

Do you envision going up against CodeQL and/or <https://www.jetbrains.com/help/qodana/about-qodana.html> by making semantic information available to the ast nodes? OT1H, I can imagine it could be an overwhelming increase in project scope, but OTOH it could also truly lead to some stunning transformation patterns

e.g. https://github.com/github/codeql/blob/v1.27.0/java/ql/exampl... or even more "textual" semantics such as

  var foo = "hello".substring(1); // knowing "foo" is a String

While not trivial because it is not documented, you can create your a database with your own facts. Some of the extractors that create the required files are open source https://github.com/github/codeql/blob/main/ruby/extractor/sr...

Efforts: Dependabot, CodeQL, Coverity, facebook's Infer tool, etc

> But why not for instance use a build system in some "container"?

I am not sure how this helps.

> I think the project could "bother" contributors with something like that, couldn't it?

Which project?

> An embedded C developer I've talked with quite often on some other forum, who imho is quite competent, said that Coverity is a poor tool that generates way too much false negatives and overlooks at the same time glaring issues.

He likely violated a license agreement with Coverity, since no one is allowed to say anything comparing Coverity to anything else.

> Said that's mostly an issue with all OpenSource tools for static C analysis.

I have been filing bug reports.

> OTOH the commercial ones are very expensive usually, with a target market of critical things like aviation of safety systems in cars and military use, places where they spend billions on projects. Nothing there for the average company, and especially not for (frankly often underfunded) OpenSource projects.

So you understand my pain.

> CodeQL? It's mostly an semantic search and replace tool, as I know? Is it that helpful? (I had a look, but the projects I'm working on don't require it. One would just use the IDE. No need for super large-scale refactorings, across projects, in our case).

I have never heard about this function. It is a static analyzer whose checks are written in the CodeQL language. However, it is very immature. When github acquired it, they banished the less reliable checks to the extended-and-security suite, leaving it only with about ~50 checks for C/C++ code. Those catch very little, although in the rare instances that they do catch things, the catches are somewhat amazing. Unfortunately, at least one of those checks provides technically correct, yet difficult to understand, explanations of the problem, so most developers would dismiss its reports as false positives despite it being correct:

https://github.com/github/codeql/issues/11744

There are probably more issues like that, but I have yet to see and report them.

> SonarCloud, hmm… This one I've used (around web development though). But am not a fan of. It bundles other "scanner" tools, with varying quality and utility. At least what they had for the languages I've actively used it was mostly about "style issues". And when it showed real errors, the IDE would do the same… (The question then is how this could be committed in the first place. But OK, some people just don't care. For them you need additional checks like SonarCloud I guess.)

It is supposed to be able to integrate into github's code scanning feature, so any newly detected issues are reported in the PR that generated them. Anyway, it is something that I am considering. I wanted to use it much sooner, but it required authorization to make changes to github on my behalf, which made me cautious about the manner in which I try it. It is basically at the bottom of my todo list right now.

> Wouldn't it be easy to add at least this to the build by using some "build container"?

I do not understand your question. To use it, we need a few things:

1. To be able to show any newly introduced defect reports in the PR that generated them shortly after it was filed.

2. To be able to scan the kernel modules since right now, it cannot due to a bad interaction between the build system and how compiler interposition is done. As of a few days ago, I have a bunch of hacks locally that enable kernel module scans, but this needs more work.

> Well, that's why I think something equivalent to `-Wall -Werror` should be switched on before writing the first line of code, in any language.

OpenZFS has had that in place for more than a decade. I do not know precisely when it was first used (although I could look if anyone is particularly interested), but my guess is 2008 when ZFSOnLinux started. Perhaps it was done at Sun before then, but both events predate me. I became involved in 2012 and it is amazing to think that I am now considered one of the early OpenZFS contributors.

Interestingly, the earliest commits in the OpenZFS repository referencing static analysis are from 2009 (with the oldest commit being from 2008 when ZFSOnLinux started). Those commits are ports of changes from OpenSolaris based on defect reports made by Coverity. There would be no more commits mentioning static analysis until 2014 when I wrote patches fixing things reported by Clang's static analyzer. Coverity was (re)introduced in 2016.

As far as the current OpenZFS repository is concerned, knowledge of static analysis died with OpenSolaris and we lost an entire form of QA until we rediscovered it during attempts to improve QA years later.

> But I guess I will stay with engraving my data into solid rock. Proven for at least hundred thousand years.

That method is no longer reliable due to acid rain. You would need to bury it in a tomb to protect it from acid rain. That has the pesky problem of the pointers being lost over time.

> At least someone needs to preserve the cat pictures and meme of our current human era for the cockroach people of the distant future. I'm not sure they will have a compatible Linux kernel and compiler available to build the ZFS drivers, or even punch card readers…

Github's code vault found a solution for that:

https://github.com/github/archive-program/blob/master/GUIDE....

I vaguely recall another effort trying to include the needed hardware in time capsules, but I could be misremembering.

Exceptions would be systems like CodeQL, but that's a bit out of scope for a game like WoW.