[clang] [Clang] Add -fwrapv-pointer flag (PR #122486)

[Eli Friedman via cfe-commits]

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@@ -4311,14 +4311,14 @@ LValue CodeGenFunction::EmitArraySubscriptExpr(const ArraySubscriptExpr *E,
     // GEP indexes are signed, and scaling an index isn't permitted to
     // signed-overflow, so we use the same semantics for our explicit
     // multiply.  We suppress this if overflow is not undefined behavior.
-    if (getLangOpts().isSignedOverflowDefined()) {
+    if (getLangOpts().PointerOverflowDefined) {
       Idx = Builder.CreateMul(Idx, numElements);
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efriedma-quic wrote:

This looks like a gap in the pointer-overflow sanitizer: we should trigger the sanitizer if the multiply overflows.  Same issue pops up in a few other places.  But you don't need to fix this in this patch, I guess.

https://github.com/llvm/llvm-project/pull/122486