[flang-commits] [flang] [flang][OpenMP] Implement loop construct iterator range (PR #170734)

[Krzysztof Parzyszek via flang-commits]

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@@ -237,6 +237,80 @@ struct OmpAllocateInfo {
 
 OmpAllocateInfo SplitOmpAllocate(const OmpAllocateDirective &x);
 
+namespace detail {
+template <bool IsConst, typename T> struct ConstIf {
+  using type = std::conditional_t<IsConst, std::add_const_t<T>, T>;
+};
+
+template <bool IsConst, typename T>
+using ConstIfT = typename ConstIf<IsConst, T>::type;
+} // namespace detail
+
+template <bool IsConst> struct LoopRange {
+  using QualBlock = detail::ConstIfT<IsConst, Block>;
+  using QualReference = decltype(std::declval<QualBlock>().front());
+  using QualPointer = std::remove_reference_t<QualReference> *;
+
+  LoopRange(QualBlock &x) { Initialize(x); }
+  LoopRange(QualReference x);
+
+  LoopRange(detail::ConstIfT<IsConst, OpenMPLoopConstruct> &x)
+      : LoopRange(std::get<Block>(x.t)) {}
+  LoopRange(detail::ConstIfT<IsConst, DoConstruct> &x)
+      : LoopRange(std::get<Block>(x.t)) {}
+
+  size_t size() const { return items.size(); }
+  bool empty() const { return items.size() == 0; }
+
+  struct iterator;
+
+  iterator begin();
+  iterator end();
+
+private:
+  void Initialize(QualBlock &body);
+
+  std::vector<QualPointer> items;
+};
+
+template <typename T> LoopRange(T &x) -> LoopRange<std::is_const_v<T>>;
+
+template <bool IsConst> struct LoopRange<IsConst>::iterator {
+  QualReference operator*() { return **at; }
+
+  bool operator==(const iterator &other) const { return at == other.at; }
+  bool operator!=(const iterator &other) const { return at != other.at; }
+
+  iterator &operator++() {
+    ++at;
+    return *this;
+  }
+  iterator &operator--() {
+    --at;
+    return *this;
+  }
+  iterator &operator++(int);
+  iterator &operator--(int);
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kparzysz wrote:

Umm, nowhere it seems.  Fixing...

https://github.com/llvm/llvm-project/pull/170734