[llvm-branch-commits] [flang] [Flang][OpenMP][MLIR] Initial derived type member map support (PR #82853)

[Sergio Afonso via llvm-branch-commits]

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@@ -88,6 +91,175 @@ void gatherFuncAndVarSyms(
     symbolAndClause.emplace_back(clause, *object.id());
 }
 
+int getComponentPlacementInParent(
+    const Fortran::semantics::Symbol *componentSym) {
+  const auto *derived =
+      componentSym->owner()
+          .derivedTypeSpec()
+          ->typeSymbol()
+          .detailsIf<Fortran::semantics::DerivedTypeDetails>();
+  assert(derived &&
+         "expected derived type details when processing component symbol");
+  int placement = 0;
+  for (auto t : derived->componentNames()) {
+    if (t == componentSym->name())
+      return placement;
+    placement++;
+  }
+  return -1;
+}
+
+std::optional<Object>
+getCompObjOrNull(std::optional<Object> object,
+                 Fortran::semantics::SemanticsContext &semaCtx) {
+  if (!object)
+    return std::nullopt;
+
+  auto ref = evaluate::ExtractDataRef(*object.value().ref());
+  if (!ref)
+    return std::nullopt;
+
+  if (std::get_if<evaluate::Component>(&ref->u))
+    return object;
+
+  auto baseObj = getBaseObject(object.value(), semaCtx);
+  if (!baseObj)
+    return std::nullopt;
+
+  return getCompObjOrNull(baseObj.value(), semaCtx);
+}
+
+llvm::SmallVector<int>
+generateMemberPlacementIndices(const Object &object,
+                               Fortran::semantics::SemanticsContext &semaCtx) {
+  std::list<int> indices;
+  auto compObj = getCompObjOrNull(object, semaCtx);
+  while (compObj) {
+    indices.push_front(getComponentPlacementInParent(compObj->id()));
+    compObj =
+        getCompObjOrNull(getBaseObject(compObj.value(), semaCtx), semaCtx);
+  }
+
+  return llvm::SmallVector<int>{std::begin(indices), std::end(indices)};
+}
+
+static void calculateShapeAndFillIndices(
+    llvm::SmallVectorImpl<int64_t> &shape,
+    llvm::SmallVector<OmpMapMemberIndicesData> &memberPlacementData) {
+  shape.push_back(memberPlacementData.size());
+  size_t largestIndicesSize =
+      std::max_element(memberPlacementData.begin(), memberPlacementData.end(),
+                       [](auto a, auto b) {
+                         return a.memberPlacementIndices.size() <
+                                b.memberPlacementIndices.size();
+                       })
+          ->memberPlacementIndices.size();
+  shape.push_back(largestIndicesSize);
+
+  // DenseElementsAttr expects a rectangular shape for the data, so all
+  // index lists have to be of the same length, this implaces -1 as filler
+  // values
+  for (auto &v : memberPlacementData)
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skatrak wrote:

Nit: Add braces, since the nested `if` is braced: https://llvm.org/docs/CodingStandards.html#id60.

https://github.com/llvm/llvm-project/pull/82853