[clang] [llvm] [openmp] [CLANG][OpenMP] Restore loop variable values after transformation directives (PR #214717)

[Alexey Bataev via llvm-commits]

================
@@ -11220,16 +11223,27 @@ checkOpenMPLoop(OpenMPDirectiveKind DKind, Expr *CollapseLoopCountExpr,
       }
 
       // Build final: IS.CounterVar = IS.Start + IS.NumIters * IS.Step
-      ExprResult Final =
-          buildCounterUpdate(SemaRef, CurScope, UpdLoc, CounterVar,
-                             IS.CounterInit, IS.NumIterations, IS.CounterStep,
-                             IS.Subtract, IS.IsNonRectangularLB, &Captures);
-      if (!Final.isUsable()) {
-        HasErrors = true;
-        break;
+      // For class-type iterator loops (non-arithmetic, non-pointer counters)
+      // in loop transformation directives, skip finalization — arithmetic on
+      // such iterators is not expressible via buildCounterUpdate.
+      ExprResult Final;
+      bool IsClassIteratorLoop =
+          !IS.CounterVar->getType()->isArithmeticType() &&
+          !IS.CounterVar->getType()->isPointerType();
+      if (IsClassIteratorLoop && isOpenMPLoopTransformationDirective(DKind)) {
+        Final = nullptr;
----------------
alexey-bataev wrote:

```suggestion
        // FIXME: finalize class-type iterators too (random-access arithmetic
        // is available per the canonical loop form).
        Final = nullptr;
```

https://github.com/llvm/llvm-project/pull/214717