[flang-commits] [openmp] [flang] [mlir] [Flang][OpenMP] Initial mapping of Fortran pointers and allocatables for target devices (PR #71766)

[via flang-commits]

================
@@ -1710,30 +1710,76 @@ bool ClauseProcessor::processLink(
 
 static mlir::omp::MapInfoOp
 createMapInfoOp(fir::FirOpBuilder &builder, mlir::Location loc,
-                mlir::Value baseAddr, std::stringstream &name,
-                mlir::SmallVector<mlir::Value> bounds, uint64_t mapType,
-                mlir::omp::VariableCaptureKind mapCaptureType,
-                mlir::Type retTy) {
-  mlir::Value varPtr, varPtrPtr;
-  mlir::TypeAttr varType;
-
+                mlir::Value baseAddr, mlir::Value varPtrPtr, std::string name,
+                mlir::SmallVector<mlir::Value> bounds,
+                mlir::SmallVector<mlir::Value> members, uint64_t mapType,
+                mlir::omp::VariableCaptureKind mapCaptureType, mlir::Type retTy,
+                bool isVal = false) {
   if (auto boxTy = baseAddr.getType().dyn_cast<fir::BaseBoxType>()) {
     baseAddr = builder.create<fir::BoxAddrOp>(loc, baseAddr);
     retTy = baseAddr.getType();
   }
 
-  varPtr = baseAddr;
-  varType = mlir::TypeAttr::get(
+  mlir::TypeAttr varType = mlir::TypeAttr::get(
       llvm::cast<mlir::omp::PointerLikeType>(retTy).getElementType());
 
   mlir::omp::MapInfoOp op = builder.create<mlir::omp::MapInfoOp>(
-      loc, retTy, varPtr, varType, varPtrPtr, bounds,
+      loc, retTy, baseAddr, varType, varPtrPtr, members, bounds,
       builder.getIntegerAttr(builder.getIntegerType(64, false), mapType),
       builder.getAttr<mlir::omp::VariableCaptureKindAttr>(mapCaptureType),
-      builder.getStringAttr(name.str()));
+      builder.getStringAttr(name));
+
   return op;
 }
 
+static mlir::omp::MapInfoOp processDescriptorTypeMappings(
+    Fortran::semantics::SemanticsContext &semanticsContext,
+    Fortran::lower::StatementContext &stmtCtx,
+    Fortran::lower::AbstractConverter &converter, mlir::Location loc,
+    mlir::Value descriptorAddr, mlir::Value descDataBaseAddr,
+    mlir::ValueRange bounds, std::string asFortran,
+    llvm::omp::OpenMPOffloadMappingFlags mapCaptureType) {
+  llvm::SmallVector<mlir::Value> descriptorBaseAddrMembers;
+  fir::FirOpBuilder &firOpBuilder = converter.getFirOpBuilder();
+
+  mlir::Value descriptor = descriptorAddr;
+
+  // The fir::BoxOffsetOp only works with !fir.ref<!fir.box<...>> types, as
+  // allowing it to access non-reference box operations can cause some
+  // problematic SSA IR. However, in the case of assumed shape's the type
+  // is not a !fir.ref, in these cases to retrieve the appropriate
+  // !fir.ref<!fir.box<...>> to access the data we need to map we must
+  // perform an alloca and then store to it and retrieve the data from the new
+  // alloca.
+  if (fir::isAssumedShape(fir::unwrapRefType(descriptorAddr.getType()))) {
+    mlir::OpBuilder::InsertPoint insPt = firOpBuilder.saveInsertionPoint();
+    firOpBuilder.setInsertionPointToStart(firOpBuilder.getAllocaBlock());
+    descriptor =
+        firOpBuilder.create<fir::AllocaOp>(loc, descriptorAddr.getType());
+    firOpBuilder.restoreInsertionPoint(insPt);
+    firOpBuilder.create<fir::StoreOp>(loc, descriptorAddr, descriptor);
----------------
agozillon wrote:

You are correct! I missed that so thank you for pointing it out, the types are indeed misaligned currently in certain cases, in the case of this PR it will indeed be a `!fir.ref<!fir.box<...` being "bound" to a `!fir.box<...` which the rest of the lowering seems fine with for the moment thankfully. 

However, I do agree they should align, but yes perhaps in another follow up PR if that sounds reasonable, I did try an early rebinding to the newly generated alloca, but in this case it doesn't seem to suffice, it'll fail the verifier. But any suggestions in how to perhaps align these in the future by anyone would be greatly appreciated, I am rather unfamiliar with the symbol binding system. 

https://github.com/llvm/llvm-project/pull/71766