What every compiler writer should know about programmers (Anton Ertl, 2015) [pdf]

Joker_vD a minute ago | parent | next [-]

In the end it all boils to a very simple argument. The C programmers want the C compilers to behave one way, the C implementers want the C compilers to behave the other way. Since the power structure is what it is — the C implementers are the ones who write the C standard and are the ones who actually get to implement the C compilers — the C compilers do, and will, behave the way the C implementers want them to.

In this situation the C programmers can either a) accept that they're programming in a language that exists as it exists, not as they'd like it to exist; b) angrily deny a); or c) switch to some other system-level language with defined semantics.

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ameliaquining 3 hours ago | parent | prev | next [-]

Previously:

https://news.ycombinator.com/item?id=11219874 (2016)

https://news.ycombinator.com/item?id=19659555 (2019)

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zephen an hour ago | parent | prev [-]

Here's a cogent argument that any decision by compiler writers that they can do whatever they wish whenever they encounter an "undefined behavior" construct is rubbish:

https://www.yodaiken.com/2021/05/19/undefined-behavior-in-c-...

And here's a cautionary tale of how a compiler writer doing whatever they wish once they encounter undefined behavior makes debugging intractable:

https://www.quora.com/What-is-the-most-subtle-bug-you-have-h...

	▲	Joker_vD 6 minutes ago \| parent [-]
		Wow, that's a very torturous reading of a specific line in a standard. And it doesn't really matter what Yodaiken thinks this line means because standard is written by C implementers for (mostly) C implementers. So if C compile writers think this line means they can use UB for optimizing purposes, then that's what it means. Yeah, I know it breaks the common illusion among the C programmers that they're "close to the bare metal", but illusions should be dispersed, not indulged. The C programmers program for the abstract C machine which is then mediated by the C compilers into machine code the way the implementers of C compilers publicly documented.