[flang-commits] [flang] [flang][OpenMP] Implement flexible OpenMP clause representation (PR #81621)

[Krzysztof Parzyszek via flang-commits]

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@@ -0,0 +1,198 @@
+//===-- Clauses.h -- OpenMP clause handling -------------------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+#ifndef FORTRAN_LOWER_OPENMP_CLAUSES_H
+#define FORTRAN_LOWER_OPENMP_CLAUSES_H
+
+#include "ClauseT.h"
+
+#include "flang/Evaluate/expression.h"
+#include "flang/Parser/parse-tree.h"
+#include "flang/Semantics/expression.h"
+#include "flang/Semantics/semantics.h"
+#include "flang/Semantics/symbol.h"
+
+#include "llvm/ADT/STLExtras.h"
+
+#include <optional>
+#include <type_traits>
+#include <utility>
+
+namespace omp {
+using namespace Fortran;
+using SomeType = evaluate::SomeType;
+using SomeExpr = semantics::SomeExpr;
+using MaybeExpr = semantics::MaybeExpr;
+
+using SymIdent = semantics::Symbol *;
+using SymReference = SomeExpr;
+
+template <typename T>
+using List = tomp::ListT<T>;
+} // namespace omp
+
+namespace tomp {
+template <>
+struct ObjectT<omp::SymIdent, omp::SymReference> {
+  using IdType = omp::SymIdent;
+  using ExprType = omp::SymReference;
+
+  const IdType &id() const { return symbol; }
+  const std::optional<ExprType> &ref() const { return designator; }
+
+  IdType symbol;
+  std::optional<ExprType> designator;
+};
+} // namespace tomp
+
+namespace omp {
+
+using Object = tomp::ObjectT<SymIdent, SymReference>;
+using ObjectList = tomp::ObjectListT<SymIdent, SymReference>;
+
+Object makeObject(const parser::OmpObject &object,
+                  semantics::SemanticsContext &semaCtx);
+Object makeObject(const parser::Name &name,
+                  semantics::SemanticsContext &semaCtx);
+Object makeObject(const parser::Designator &dsg,
+                  semantics::SemanticsContext &semaCtx);
+Object makeObject(const parser::StructureComponent &comp,
+                  semantics::SemanticsContext &semaCtx);
+
+inline auto makeObjectF(semantics::SemanticsContext &semaCtx) {
+  return [&](auto &&s) { return makeObject(s, semaCtx); };
+}
+
+template <typename T>
+SomeExpr makeExpr(T &&inp, semantics::SemanticsContext &semaCtx) {
+  auto maybeExpr = evaluate::ExpressionAnalyzer(semaCtx).Analyze(inp);
+  assert(maybeExpr);
+  return std::move(*maybeExpr);
+}
+
+inline auto makeExprF(semantics::SemanticsContext &semaCtx) {
+  return [&](auto &&s) { return makeExpr(s, semaCtx); };
+}
+
+template <
+    typename ContainerTy, typename FunctionTy,
+    typename ElemTy = typename llvm::remove_cvref_t<ContainerTy>::value_type,
+    typename ResultTy = std::invoke_result_t<FunctionTy, ElemTy>>
+List<ResultTy> makeList(ContainerTy &&container, FunctionTy &&func) {
+  List<ResultTy> v;
+  llvm::transform(container, std::back_inserter(v), func);
+  return v;
+}
+
+inline ObjectList makeList(const parser::OmpObjectList &objects,
+                           semantics::SemanticsContext &semaCtx) {
+  return makeList(objects.v, makeObjectF(semaCtx));
+}
+
+template <typename F, typename T, typename U = std::invoke_result_t<F, T>>
+std::optional<U> maybeApply(F &&func, const std::optional<T> &inp) {
+  if (!inp)
+    return std::nullopt;
+  return std::move(func(*inp));
+}
+
+std::optional<Object>
+getBaseObject(const Object &object,
+              Fortran::semantics::SemanticsContext &semaCtx);
+
+namespace clause {
+#ifdef EMPTY_CLASS
+#undef EMPTY_CLASS
+#endif
+#define EMPTY_CLASS(cls)                                                       \
+  using cls = tomp::clause::cls##T<SymIdent, SymReference>
+
+#ifdef WRAPPER_CLASS
+#undef WRAPPER_CLASS
+#endif
+#define WRAPPER_CLASS(cls, content)                                            \
+  [[maybe_unused]] extern int xyzzy_semicolon_absorber
+#define GEN_FLANG_CLAUSE_PARSER_CLASSES
+#include "llvm/Frontend/OpenMP/OMP.inc"
+#undef EMPTY_CLASS
+#undef WRAPPER_CLASS
+
+using Aligned = tomp::clause::AlignedT<SymIdent, SymReference>;
+using Allocate = tomp::clause::AllocateT<SymIdent, SymReference>;
+using Allocator = tomp::clause::AllocatorT<SymIdent, SymReference>;
+using AtomicDefaultMemOrder =
----------------
kparzysz wrote:

The empty clauses are specialized automatically in the macro+include above.  I can delete `AtomicDefaultMemOrder` if you want, but then we'd lose completeness.  I can add a comment here explaning the "requires" case.  Let me know what you'd prefer.

This may all be moot, because the generic variant visitors may require specializations and "make" functions for every alternative in the variant.  I'll try to see what happens if I remove this one specialization.

https://github.com/llvm/llvm-project/pull/81621