On 11/29/21 11:53 AM, Martin Sebor wrote:
On 11/29/21 6:09 AM, Richard Biener via Gcc-patches wrote:
This removes more cases that appear when bootstrap with
-Wunreachable-code-return progresses.
...
diff --git a/gcc/sel-sched-ir.h b/gcc/sel-sched-ir.h
index 8ee0529d5a8..18e03c4cb96 100644
--- a/gcc/sel-sched-ir.h
+++ b/gcc/sel-sched-ir.h
@@ -1493,8 +1493,6 @@ bb_next_bb (basic_block bb)
default:
return bb->next_bb;
}
-
- gcc_unreachable ();
}
Just skiming the changes out of curiosity, this one makes me
wonder if the warning shouldn't be taught to avoid triggering
on calls to __builtin_unreachable(). They can help make code
more readable (e.g., after a case and switch statement that
handles all values).
I see someone else raised the same question in a patch I hadn't
gotten to yet:
https://gcc.gnu.org/pipermail/gcc-patches/2021-November/585431.html
If you do end up removing the gcc_unreachable() calls, I would
suggest to replace them with a comment so as not to lose
the readability benefit.
But I still wonder if it might make sense to teach the warning
not just about __builtin_unreachable() but also about noreturn
calls like abort() that (as you explained in the thread above)
gcc_unreachable() expands to. Is there a benefit to warning
on such calls?
Martin
