`three = 1` in the Linux sourcecode (2014)

Post by rkangel » Tue, Mar 09, 2021, 6:58 PM UTC

chasd00 wrote: post #78

rkangel wrote: post #35

Earlier quoted context omitted.

I once spent two days debugging confusing behaviour in a serial command interface before discovering the line: #define CR_LF "\n"

man, that hurts. When you found the issue were you happy or were you just depressed? I've been there and sometimes finding the root of an issue is not a eureka moment but more just a long, deflating, sigh.

Post by jfengel » Tue, Mar 09, 2021, 7:06 PM UTC

klyrs wrote: post #83

jfengel wrote: post #81

Earlier quoted context omitted.

And then, having located that comment, try to rename the variable to something more meaningful. Even gap1, gap2, and gap3 would be more informative.

We have a difference of opinion here. I lean away from bikeshedding in favor of finding more substantive issues. I'm also an old-timer and I'd call this a 3, on a scale from 1 (easily readable code) to 10 (a suitable IOCCC entry)

Post by shortstuffsushi » Tue, Mar 09, 2021, 7:31 PM UTC

gumby wrote: post #24

derfitt wrote: post #15

Earlier quoted context omitted.

'Without digging deeper' isn't really what matters here. A better question would be 'after some very cursory further digging, are we worried?' The first thing I ask myself when I see something that looks as wrong as this does is "Is it possible for this piece of code to be completely broken, and for no one to have noticed yet?" This is really a question about two processes - the one where people look at, read, edit a…

> The first thing I ask myself when I see something that looks as wrong as this does is "Is it possible for this piece of code to be completely broken, and for no one to have noticed yet?" Good reflex. In my first job out of school (big research lab), we would occasionally find odd bugs in the code base (as would be expected...bugs happen). The head of the project would often wonder, “how could the system ever have f…

Post by cratermoon » Tue, Mar 09, 2021, 7:38 PM UTC

Skeime wrote: post #60

yiyus wrote: post #55

Earlier quoted context omitted.

I would do this: #define I 1 #define II 2 #define III 3 ... #define XIII 13 There is no zero in roman numerals, but you can use NULL for extra fun! (yes, I am a bad person)

For extra fun, put it into the code like this, including the `...` instead of the actual values. (Make it compile by commenting that line out.) Then define IV somewhere else but make sure to use III before every use IV so someone unfamiliar with these constants see the “right” definitions first.

    iv = secrets.randbits(IV)
    plaintext = "Text for encryption"
    aes = pyaes.AESModeOfOperationCTR(key, pyaes.Counter(iv))
    ciphertext = aes.encrypt(plaintext)
    print('Encrypted:', binascii.hexlify(ciphertext))

Post by cratermoon » Tue, Mar 09, 2021, 7:52 PM UTC

loa_in_ wrote: post #70

yoz-y wrote: post #41

Earlier quoted context omitted.

It's "obvious" if you take into account the corporate culture I guess. The rule of 'no magic numbers' is generally good, but then one has to remember that some numbers (like 0 and 1) are not magic.

0 and 1 can be magic if the context depends on them being arbitrarily 0 or 1. eg. // this byte is unused and always 0 #define UNUSED_CONSTANT_FIELD_VALUE 0 bytes = {HEADER, UNUSED_CONSTANT_FIELD_VALUE, [...]}