undefined
Ooo. The plot thickens.
What does printf("%c", '\0') do?
Answer: output a character of value 0.
What should printf("%lc", (wint_t)L'\0') do?
Answer: output nothing.
That's because %lc is *defined* to be equivalent to %ls with a two-element wchar_t array, the first holding the wint_t parameter (cast to a wchar_t) and the second a null wide character. If I'm right, then glibc has a bug here.
Here's a nice C puzzle this evening.
What type is a L'c' wide character constant?
Answer: wchar_t.
What type does the fprintf '%lc' format take?
Answer: wint_t.
So you need to cast your wide character when printing it with the conversion specifier which accepts wide characters.
Also, shout-out to gcc for msp430 where wchar_t is 32 bits (long int) and wint_t is 16 bits (unsigned int). I'm sure there's a story there.
Picolibc 1.8.11 released today. So many changes, so many contributors. Thanks all.
Main picolibc page: https://keithp.com/picolibc/
Microsoft GitHub page: https://github.com/picolibc/picolibc/releases/tag/1.8.11
Support for using picolibc as the primary C library with GCC landed today. Thanks much to Jeffrey Law and Andrew Pinski for their help improving the changes and getting them merged. https://gcc.gnu.org/git/gitweb.cgi?p=gcc.git;a=commit;h=72274d0a421785ed38ad704af1192a7578660e7f
I managed to merge five PRs from other picolibc contributors today. I really like getting contributions from other other people; it makes me think that maybe my little project is starting to be useful in the world.
@vitaut Can also recommend the sequel -- "Elementary Functions". Riveting action sequences.
I received a bug report about picolibc's iconv implementation. So I added a test case. Which pushed the CI runtime up over *six hours* at which point github gave up and killed it.
I spent a bit of time yesterday and today re-implementing the JIS to Unicode conversion function to make it faster. Lines changed: 5125 additions & 7495 deletions. Runtime is back to normal now. And I have a deeper understanding of these encodings. https://github.com/picolibc/picolibc/pull/1141/changes/8be32431abcfb9848c6633ba23c8f65cd9d68b12