DeVault: Announcing the Hare programming language

DeVault: Announcing the Hare programming language

> By invoking the idea of a "list of system routines", you're extending the language beyond C89.

Which is the only way to have PTEs in C code.

If you have such an address then you have to extend the language somehow. Or, alternatively, don't touch it.

Of course. Because it's impossible to write C89 program which changes the PTEs, such a concept just couldn't exist in it. You have to extend the language to cover that usecase.

…then such compilers would have been as popular as ISO 7185. Means: no one would have cared about these and no one would have mentioned their existence.

Yes. But some programs would still be possible. Programs which do tricks with pointers would work just fine, programs which touch PTEs wouldn't.

Citation needed. Badly. Because, I would repeat once more, in C89 (not in C99 and newer) the notion of “pointers which have the same bitpattern yet different” doesn't exist. If you add a few bits to the pointer converted to integer and then clear these same bits you would get the exact same pointer — guaranteed. The fact that these bits are lowest bits of converted integer is implementation-specific thing, you can imagine a case where these would live as top bits, e.g. So yet, that requires some implementation-specific extension. But pretty mild and limited.

Yes, provenance is an attempt to deal with the idea of C99+ that some pointers may be equal to others yet, somehow, still different — but that's not allowed in C89. If two pointers are equal then they are either both null pointers, or both point to the same object, end of story.

Sure, it makes some optimizations hard and/or impossible. So what? This just means that you cannot do such optimizations in C89 mode. Offer -fno-provenance option, enable it for -std=c89, done.