On Fri, Aug 02, 2024 at 05:48:13PM +0200, Thomas Weißschuh wrote:
With all these libc functionality added, it isn't nolibc looks like :)
Well :-)
The main motivation is to provide kselftests compatibility. Maybe Willy disagrees.
No no I'm perfectly fine with adding the functions that developers use or need to write their test or init tools. I don't have any strong opinion on scanf(). Just like strtok(), I stopped using it 25 years ago when I noticed that it never survives code evolutions, lacks a lot of flexibility and is often strongly tied to your types (more than printf where you can cast). But I perfectly understand that others are used to it and would appreciate to have it, for example if it helps with command line arguments.
+static int test_scanf(void) +{
- unsigned long long ull;
- unsigned long ul;
- unsigned int u;
- long long ll;
- long l;
- void *p;
- int i;
- if (sscanf("", "foo") != EOF)
return 1;- if (sscanf("foo", "foo") != 0)
return 2;- if (sscanf("123", "%d", &i) != 1)
return 3;- if (i != 123)
return 4;- if (sscanf("a123b456c0x90", "a%db%uc%p", &i, &u, &p) != 3)
return 5;- if (i != 123)
return 6;- if (u != 456)
return 7;- if (p != (void *)0x90)
return 8;- if (sscanf("a b1", "a b%d", &i) != 1)
return 9;- if (i != 1)
return 10;- if (sscanf("a%1", "a%%%d", &i) != 1)
return 11;- if (i != 1)
return 12;- if (sscanf("1|2|3|4|5|6",
"%d|%ld|%lld|%u|%lu|%llu",&i, &l, &ll, &u, &ul, &ull) != 6)return 13;- if (i != 1 || l != 2 || ll != 3 ||
u != 4 || ul != 5 || ull != 6)return 14;- return 0;
Can we simplify this code? It is hard to read code with too many conditions. Maybe defining an array test conditions instead of a series ifs.
I tried that and didn't find a way. Any pointers are welcome.
I think it would be difficult by nature of varargs.
However, since you grouped some expressions, maybe a one-liner comment between each scanf() to explain the intent of the test would make it easier to follow. E.g: /* test multiple naked numbers */ ... /* test numbers delimited with a character */ ... /* test multiple integer types at once */
etc. This allows the reviewer to more easly re-focus on the test they were reading.
Willy