[flang-commits] [flang] [llvm] [Flang][OpenMP] Defer descriptor mapping for assumed dummy argument types (PR #154349)

[Kareem Ergawy via flang-commits]

================
@@ -593,6 +656,125 @@ class MapInfoFinalizationPass
     return nullptr;
   }
 
+  void addImplictDescriptorMapToTargetDataOp(mlir::omp::MapInfoOp op,
+                                             fir::FirOpBuilder &builder,
+                                             mlir::Operation *target) {
+    // Checks if the map is present as an explicit map already on the target
+    // data directive, and not just present on a use_device_addr/ptr, as if
+    // that's the case, we should not need to add an implicit map for the
+    // descriptor.
+    auto explicitMappingPresent = [](mlir::omp::MapInfoOp op,
+                                     mlir::omp::TargetDataOp tarData) {
+      // Verify top-level descriptor mapping is at least equal with same
+      // varPtr, the map type should always be To for a descriptor, which is
+      // all we really care about for this mapping as we aim to make sure the
+      // descriptor is always present on device if we're expecting to access
+      // the underlying data.
+      if (tarData.getMapVars().empty())
+        return false;
+
+      for (mlir::Value mapVar : tarData.getMapVars()) {
+        auto mapOp =
+            llvm::dyn_cast<mlir::omp::MapInfoOp>(mapVar.getDefiningOp());
----------------
ergawy wrote:

```suggestion
            llvm::cast<mlir::omp::MapInfoOp>(mapVar.getDefiningOp());
```

https://github.com/llvm/llvm-project/pull/154349