[flang-commits] [flang] [OpenMP][Flang] Emit default declare mappers implicitly for derived types (PR #140562)

[via flang-commits]

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@@ -61,6 +67,144 @@ namespace Fortran {
 namespace lower {
 namespace omp {
 
+mlir::FlatSymbolRefAttr getOrGenImplicitDefaultDeclareMapper(
+    lower::AbstractConverter &converter, mlir::Location loc,
+    fir::RecordType recordType, llvm::StringRef mapperNameStr) {
+  if (mapperNameStr.empty())
+    return {};
+
+  if (converter.getModuleOp().lookupSymbol(mapperNameStr))
+    return mlir::FlatSymbolRefAttr::get(&converter.getMLIRContext(),
+                                        mapperNameStr);
+
+  fir::FirOpBuilder &firOpBuilder = converter.getFirOpBuilder();
+  mlir::OpBuilder::InsertionGuard guard(firOpBuilder);
+
+  firOpBuilder.setInsertionPointToStart(converter.getModuleOp().getBody());
+  auto declMapperOp = mlir::omp::DeclareMapperOp::create(
+      firOpBuilder, loc, mapperNameStr, recordType);
+  auto &region = declMapperOp.getRegion();
+  firOpBuilder.createBlock(&region);
+  auto mapperArg = region.addArgument(firOpBuilder.getRefType(recordType), loc);
+
+  auto declareOp = hlfir::DeclareOp::create(firOpBuilder, loc, mapperArg,
+                                            /*uniq_name=*/"");
+
+  const auto genBoundsOps = [&](mlir::Value mapVal,
+                                llvm::SmallVectorImpl<mlir::Value> &bounds) {
+    fir::ExtendedValue extVal =
+        hlfir::translateToExtendedValue(mapVal.getLoc(), firOpBuilder,
+                                        hlfir::Entity{mapVal},
+                                        /*contiguousHint=*/true)
+            .first;
+    fir::factory::AddrAndBoundsInfo info = fir::factory::getDataOperandBaseAddr(
+        firOpBuilder, mapVal, /*isOptional=*/false, mapVal.getLoc());
+    bounds = fir::factory::genImplicitBoundsOps<mlir::omp::MapBoundsOp,
+                                                mlir::omp::MapBoundsType>(
+        firOpBuilder, info, extVal,
+        /*dataExvIsAssumedSize=*/false, mapVal.getLoc());
+  };
+
+  const auto getFieldRef = [&](mlir::Value rec, llvm::StringRef fieldName,
+                               mlir::Type fieldTy, mlir::Type recType) {
+    mlir::Value field = fir::FieldIndexOp::create(
+        firOpBuilder, loc, fir::FieldType::get(recType.getContext()), fieldName,
+        recType, fir::getTypeParams(rec));
+    return fir::CoordinateOp::create(
+        firOpBuilder, loc, firOpBuilder.getRefType(fieldTy), rec, field);
+  };
+
+  llvm::SmallVector<mlir::Value> clauseMapVars;
+  llvm::SmallVector<llvm::SmallVector<int64_t>> memberPlacementIndices;
+  llvm::SmallVector<mlir::Value> memberMapOps;
+
+  mlir::omp::ClauseMapFlags mapFlag = mlir::omp::ClauseMapFlags::to;
+  mapFlag |= mlir::omp::ClauseMapFlags::from;
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agozillon wrote:

Nit: could probably just combine the mapFlag into one line via "|"

https://github.com/llvm/llvm-project/pull/140562