llvm-project

57a593f6 - [libc++] Remove obsolete locale-specific regex tests (#159590)

[libc++] Remove obsolete locale-specific regex tests (#159590) After a recent macOS update, several of the locale-specific regex tests started failing. These tests were mainly testing two locale specific features of regular expressions: - A character class like `[=x=]` matches any character that is considered equivalent to `x` according to the collation rules of the current locale. - A character class like `[[.ch.]]` matches anything that is equivalent to `ch` (whether as two letters or as a single collation element) in the current locale. However, these tests were relying on platform-specific localization data, specifically they were only working with older macOS localization data. As can be seen from the numerous XFAILs, most mainstream platforms didn't actually pass this test. After the macOS update, macOS itself also doesn't pass these tests anymore. I looked at whether there are locales where these tests would still make sense, and I couldn't find any. I am not a localization expert, but it appears that only legacy locales like the traditional Spanish locale (which isn't commonly shipped on systems anymore) considers `[.ch.]` to be a single collation element. Therefore, it seems that the locale specific part of these tests is not relevant anymore, and this patch removes them. The patch also moves some tests for equivalence classes inside character classes to their non locale-specific tests, since that feature was not covered there. Finally, the lookup_collatename.pass.cpp test was fixed by removing an assertion that `ch` is a collation element in the CZ locale, which seems to not be the case in recent localization data (and appears to be the root cause for about half the failures in these tests).