[clang] [lldb] [Clang] Introduce OverflowBehaviorType for fine-grained overflow control (PR #148914)

[Justin Stitt via cfe-commits]

================
@@ -112,6 +112,25 @@ class LangOptionsBase {
     SOB_Trapping
   };
 
+  // Used by __attribute__((overflow_behavior())) to describe overflow behavior
+  // on a per-type basis.
+  enum OverflowBehaviorKind {
+    // Default C standard behavior (type dependent).
+    OB_Unset,
+
+    // __attribute__((overflow_behavior("wrap")))
+    OB_Wrap,
+
+    // __attribute__((overflow_behavior("no_wrap")))
+    OB_NoWrap,
+
+    // Signed types defined as wrapping via -fwrapv can still be instrumented
+    // by sanitizers (PR82432). This field is needed to disambiguate canonical
+    // wrapping type behaviors from -fwrapv behaviors.
+    // -fwrapv
+    OB_FWrapv
----------------
JustinStitt wrote:

But I am also using this interface for unsigned types for which `OB_Undefined` would be ill-suited.

Perhaps you're hinting that this interface should change entirely but I really don't have any better ideas. For now, I'll send a commit addressing your review and if you want further changes let me know.

https://github.com/llvm/llvm-project/pull/148914