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C can be memory-safe (2023)

blog.erratasec.com C can be memory-safe

The idea of memory-safe languages  is in the news lately. C/C++ is famous for being the world's system language (that runs most things) but ...

C can be memory-safe
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  • Forking is a foolish idea. The core principle of computer-science is that we need to live with legacy, not abandon it.

    what a crazy thing to say. The core principle of computer-science is to continue moving forward with tech, and to leave behind the stuff that doesn't work. You don't see people still using fortran by choice, you see them living with it because they're completely unable to move off of it. If you're able to abandon bad tech then the proper decision is to do so. OP keeps linking Joel, but Joel doesn't say to not rewrite stuff, he says to not rewrite stuff for large scale commercial applications that currently work. C clearly isn't working for a lot of memory safe applications. The logic doesn't apply there. It also clearly doesn't apply when you can write stuff in a memory safe language alongside existing C code without rewriting any C code at all.

    And there's no need. Modern C compilers already have the ability to be memory-safe, we just need to make minor -- and compatible -- changes to turn it on. Instead of a hard-fork that abandons legacy system, this would be a soft-fork that enables memory-safety for new systems.

    this has nothing to do with the compiler, this has to do with writing 'better' code, which has proved impossible over and over again. The problem is the programmers and that's never going to change. Using a language that doesn't need this knowledge is the better choice 100% of the time.

    C devs have been claiming 'the language can do this, we just need to implement it' for decades now. At this point it's literally easier to slowly port to a better language than it is to try and 'fix' C/C++.

    • this has to do with writing ‘better’ code, which has proved impossible over and over again

      I can't speak for C, as I don't follow it that much, but for C++, this is just not fair. It has been proven repeatedly that it can be done better, and much better. Each iteration has made so many things simpler, more productive, and also safer. Now, there are two problems with what I just said:

      • That it has been done safer, that doesn't mean that everyone makes good use of it.
      • That it has been done safer, doesn't mean that everything is fixable, and that it's on the same level of other, newer languages.

      If that last part is what you mean, fine. But the way that you phrased (and that I quoted) is just not right.

      At this point it’s literally easier to slowly port to a better language than it is to try and ‘fix’ C/C++.

      Surely not for everything. Of course I see great value if I can stop depending on OpenSSL, and move to a better library written in a better language. Seriously looking forward for the day when I see dynamic libraries written in Rust in my package manager. But I'd like to see what's the plan for moving a large stack of C and C++ code, like a Linux distribution, to some "better language". I work everyday on such a stack (e.g. KDE Neon in my case, but applicable to any other typical distro with KDE or GNOME), and deploy to customers on such a stack (on Linux embedded like Yocto). Will the D-Bus daemon be written in Rust? Perhaps. Systemd? Maybe. NetworkManager, Udisks, etc.? Who knows. All the plethora of C and C++ applications that we use everyday? Doubtful.

      • I can’t speak for C, as I don’t follow it that much, but for C++, this is just not fair. It has been proven repeatedly that it can be done better, and much better. Each iteration has made so many things simpler, more productive, and also safer. Now, there are two problems with what I just said:

        That comment was not talking about programming languages, it was talking about human's inability to write perfect code. Humans are unable to solve problems correctly 100% of the time. So if the language doesn't do it for them then it will not happen. See Java for a great example of this. Java has Null Pointer Exceptions absolutely everywhere. So a bunch of different groups created annotations that would give you warnings, and even fail to compile if something was mismatched or a null check was missed. But if you miss a single @NotNull annotation anywhere in the code, then suddenly you can get null errors again. It's not enforced by the type system and as a result humans can forget. Kotlin came along and 'solved it' at the type level, where types are nullable or non-nullable. But, hilariously enough, you can still get NPEs in Kotlin because it's commonly used to interop with Java.

        My point is that C/C++ can't solve this at a fundamental level, the same way Kotlin and Java cannot solve this. Programmers are the problem, so you have to have a system that was built from the ground up to solve the problem. That's what we are getting in modern day languages. You can't just tack the system on after the fact, unless it completely removes any need for the programmer to do literally anything, because the programmer is the problem.

        Surely not for everything. Of course I see great value if I can stop depending on OpenSSL, and move to a better library written in a better language. Seriously looking forward for the day when I see dynamic libraries written in Rust in my package manager. But I’d like to see what’s the plan for moving a large stack of C and C++ code, like a Linux distribution, to some “better language”. I work everyday on such a stack (e.g. KDE Neon in my case, but applicable to any other typical distro with KDE or GNOME), and deploy to customers on such a stack (on Linux embedded like Yocto). Will the D-Bus daemon be written in Rust? Perhaps. Systemd? Maybe. NetworkManager, Udisks, etc.? Who knows. All the plethora of C and C++ applications that we use everyday? Doubtful.

        I'm not talking about whole scale rewrites. I'm talking about what Linux is already doing with writing new code in Rust, or small portions of performance critical code in a memory safe language. I'm not talking about like what Fish Shell did and rewrote the whole codebase in one go, because that's not realistic. But slowly converting an entire codebase over? That's incredibly realistic. I've done so with several 250k+ line Java codebases, converting them to Kotlin. When languages are built to be easy to move to (Rust, Kotlin, etc), then migrating to them slowly over time where it matters is easily attainable.

    • The core principle of computer-science is to continue moving forward with tech, and to leave behind the stuff that doesn’t work.

      I'm not sure you realize you're proving OP's point.

      Rewriting projects from scratch by definition represent big step backwards because you're wasting resources to deliver barely working projects that have a fraction of the features that the legacy production code already delivered and reached a stable state.

      And you are yet to present a single upside, if there is even one.

      At this point it’s literally easier to slowly port to a better language than it is to try and ‘fix’ C/C++.

      You are just showing the world you failed to read the article.

      Also, it's telling that you opt to frame the problem as "a project is written in C instead of <insert pet language> instead of actually secure and harden existing projects.

      • And you are yet to present a single upside, if there is even one.

        This is a flippant statement, honestly, as it disregards the premise of the discussion. It's memory safety. That's the upside. The author even linked to memory safety bugs in OpenSSL. They might still exist elsewhere. (I realize there is a narrow class of memory bugs that C compilers understand, but it's just that, a narrow class). We have scant way of knowing whether or not they exist without significant testing effort that is not likely to happen. And it would be fighting a losing battle anyway, because someone is writing new C code to maintain these legacy systems.

      • Rewriting projects from scratch by definition represent big step backwards because you’re wasting resources to deliver barely working projects that have a fraction of the features that the legacy production code already delivered and reached a stable state.

        Joel's point was about commercial products not programming languages. I'm not the one misunderstanding here. When people talk about using Rust, it's not talking about rewriting every single thing ever written in C/C++. It's about leaving C/C++ behind and moving on to something that doesn't have the issues of the past. This is not about large scale commercial rewrites. It's about C's inability to deal with these problems.

        You are just showing the world you failed to read the article.

        sure thing bud.

        Also, it’s telling that you opt to frame the problem as "a project is written in C instead of <insert pet language> instead of actually secure and harden existing projects.

        I didn't say that and you know it. Also it's quite telling (ooh, I can say the same things you can) that you think "better language" means "pet language". Actually laughable.

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