https://gcc.gnu.org/bugzilla/show_bug.cgi?id=105273
--- Comment #2 from Ævar Arnfjörð Bjarmason <avarab at gmail dot com> --- ...To finish the report (Bugzilla's eager submitting threw me for a loop) the issue is that while the analyzer is right in the *general* case about a "switch" with a missing "default" being something that *could* be fed any arbitrary value, in this case all of the possible values can be determined at a compile-time. Which is all this bug report is suggesting as an initial report, that it would be nice to have that narrow case handled. END OF NARROW REPORT More generally though (and perhaps I should submit another report for this) it's a really useful feature of GCC (and clang) that with C they put a bit of trust in the programmer with -Wswitch (which is enabled under -Wall). Because even though there are cases where the programmer is wrong and exhaustively enumerating the enum labels isn't sufficient, in the general case being able to avoid "default" cases in favor of exhaustively listing the labels avoids a *lot* of subtle bugs in larger codebases. That's because the values being thrown around to "switch" on are validated already by [insert magic here], but whenever *new* values are added it's really important to not miss 1/N switch statements that new labels need to be added to. In the testcase for this bug the compiler has enough visibility to determine this to be true without the "[insert magic here]", but in cases where that's not true it seems to me that those users -fanalyzer would be encouraged to add "default" cases just to appease the compiler, and thus get worse warnings from -Wswitch. I may be missing something obvious, but it would be nice to have some way out of that where you can have your cake & eat it too. I.e. only have -fanalyze complain about this class of issue where -Wswitch would complain, and have the current behavior in GCC 12.0 hidden behind some opt-in sub-flag of -Wanalyzer-use-of-uninitialized-value. Anyway, just my 0.02. Thanks a lot for -fanalyze, I've been trying it out on the git codebase and it's uncovered a lot of genuine issues already. I'm just filing some bugs for the long tail where the analyzer seemed to be wrong/lacking. Thanks!
