[clang] [compiler-rt] [UBSan] Add check that detects division by zero for fixed-point types (PR #165181)

[Vitaly Buka via cfe-commits]

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@@ -149,7 +151,7 @@ SANITIZER("shadow-call-stack", ShadowCallStack)
 // ABI or address space layout implications, and only catch undefined behavior.
 SANITIZER_GROUP("undefined", Undefined,
                 Alignment | Bool | Builtin | ArrayBounds | Enum |
-                    FloatCastOverflow |
+                    FixedPoint | FloatCastOverflow |
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vitalybuka wrote:

Usually we put into "undefined" only stuff which clearly violates the standard.
We have other checks which are not not part of "undefined".
Not sure how to deal with extension.
I propose to keep it opt-in for at least one major version and reconsider later.


https://github.com/llvm/llvm-project/pull/165181