[flang] [llvm] [flang][OpenMP] Parsing support for iterator modifiers in FROM and TO (PR #114593)

[Kiran Chandramohan via llvm-commits]

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@@ -268,6 +269,57 @@ bool OmpStructureChecker::IsCloselyNestedRegion(const OmpDirectiveSet &set) {
   return false;
 }
 
+namespace {
+struct ContiguousHelper {
+  ContiguousHelper(SemanticsContext &context)
+      : sctx_(context), fctx_(context.foldingContext()) {}
+
+  template <typename Contained>
+  std::optional<bool> Visit(const common::Indirection<Contained> &x) {
+    return Visit(x.value());
+  }
+  template <typename Contained>
+  std::optional<bool> Visit(const common::Reference<Contained> &x) {
+    return Visit(x.get());
+  }
+  template <typename T> std::optional<bool> Visit(const evaluate::Expr<T> &x) {
+    return std::visit([this](auto &&s) { return Visit(s); }, x.u);
+  }
+  template <typename T>
+  std::optional<bool> Visit(const evaluate::Designator<T> &x) {
+    return common::visit(
+        [this](auto &&s) { return evaluate::IsContiguous(s, fctx_); }, x.u);
+  }
+  template <typename T> std::optional<bool> Visit(const T &) {
+    // Everything else.
+    return std::nullopt;
+  }
+
+private:
+  SemanticsContext &sctx_;
+  evaluate::FoldingContext &fctx_;
+};
+} // namespace
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kiranchandramohan wrote:

Why do we need this? I see that there is `IsContiguous` that works in check-expression.

https://github.com/llvm/llvm-project/pull/114593