libc: add test for strnlen()

[strajabot]

Summary

Tests for strnlen, checks alignments from up to 16 and buffer sizes up to 64, also checks that passing SIZE_MAX as maxlen, because it can cause a wraparound error if strnlen is incorrect.

[fuz]

This test looks reasonable.

It might make sense to split SIZE_MAX tests into a separate main test case as it tests a special case of the function.

lib/libc/tests/string/strnlen_test.c

31

You should be able to do the memset only once outside of the loop. Note that initialising with ... = { '/' } only sets the first element of the buffer to '/', the others are set to zero. So memset is indeed needed.

33

maxlen should be of type size_t. Use %zu to print a variable of type size_t.

96–97

105–106

same change here

[strajabot]

• separate strnlen_alignments into two tests

[fuz]

LGTM

[kib]

lib/libc/tests/string/strnlen_test.c

26

Extra blank line

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32

35

41

43

Indent is wrong

51

53

Same style issues below

87

Extra blank line