Comment by raphlinus | Hacker News Reader

Comment by raphlinus | Hacker News Reader

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Another characteristic of this topic is that people from different camps keep talking past each other, and the discussion goes in circles.

What you propose is basically identical to Regehr's "Proposal for a Friendly Dialect of C". What's different in 2021 that will make it succeed now when it failed in 2014? If anything, there's less interest now, as there are viable alternatives and increased investment in tools that work with standard C.

Small bugs are being fixed. One of the most surprising is that shift-left of a negative number was UB (a fact that would be shocking to anyone in the semi-portable camp, who would reasonably expect to to compile to SAL on x86). Fortunately, this (ETA: hopefully) will be fixed in C2x.

ETA: As of N2596, it's still not fixed in the C2x draft. There certainly have been proposals to fix it, and I thought it had been agreed upon, but if so, it hasn't found its way into the draft yet. In the mean time, good luck shifting those negative integers!

"What's different in 2021 that will make it succeed now when it failed in 2014? If anything, there's less interest now, as there are viable alternatives and increased investment in tools that work with standard C."

You may be right, but many things could conceivably change.

Viable alternatives like Rust may result in C losing ground and feeling pressure to keep up.

Some huge corporation could announce a focus on security and that they will try to minimize C usage.

More people could adopt the goal of a "friendly dialect of C", and be more determined or successful.

Compiler developers could somehow step over the line -- make a compiler that makes such wild optimizations that it results in a backlash.

Or it could just be improved very gradually, with little bits of the "friendly dialect" being adopted one by one rather than all at once.

I'm not saying by any means I'm confident in anything of the sort, but things change a lot over time. Back when I was getting started, Perl was everywhere. Today pretty much nobody does big Perl projects anymore. It had a big miss with Perl 6, and that was bad enough that it got overtaken by competition. While C is much bigger and more resilient I think it's not impossible by any means for it to feel pressure to adapt.

I definitely expect a lot of resistance to change, but the world changes nonetheless.

I didn't like Regehr's proposal because I don't want a friendly dialect of C. I mostly just want C the way it worked up until, say, GCC 4.x.

I don't know specifically how to fix the standard, although I've been thinking about it. A simple idea would be like the Linux mandate "don't break userspace." The language-lawyering has to stop, and more rules are unlikely to help.

"C the way it worked until GCC 4.x" is basically a worse version of friendly C.

You can't on the one hand say "no language lawyering" and on the other hand call certain kinds of optimizations bugs. Compiler developers need to be able to tell something will be considered a bug before users complain--you can always compile on -O0 if you don't want compiler optimizations, and many people consider performance regressions bugs in their own right, so they're going to try to eke out every bit of performance they can on higher optimization levels.

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