[flang][acc] Add infrastructure and tests for ACCImplicitData (#166797)

This PR adds the necessary infrastructure to enable testing of the
ACCImplicitData pass for FIR/HLFIR, along with comprehensive test
coverage for implicit data clause generation in OpenACC constructs.

New Infrastructure:
- Add FIROpenACCSupport analysis providing FIR-specific implementations
of OpenACCSupport interface methods for variable name extraction, recipe
name generation, and NYI emission
- Add FIROpenACCUtils with helper functions for:
  * Variable name extraction from FIR operations (getVariableName)
  * Recipe name generation with FIR type string representation
  * Bounds checking for constant array sections
- Add ACCInitializeFIRAnalyses pass to pre-register FIR analyses
(OpenACCSupport and AliasAnalysis) for use by subsequent OpenACC passes
in the pipeline

Refactoring in flang/lib/Lower/OpenACC.cpp:
- Move bounds string generation and bounds checking to FIROpenACCUtils
- Refactor recipe name generation to use fir::acc::getRecipeName

Test Coverage:
- acc-implicit-firstprivate.fir: Tests implicit firstprivate behavior
for scalar types (i8, i16, i32, i64, f32, f64, logical, complex) in
parallel/serial constructs with recipe generation verification
- acc-implicit-data.fir: Tests implicit data clauses for scalars,
arrays, derived types, and boxes in kernels/parallel/serial with
default(none) and default(present) variations
- acc-implicit-data-fortran.F90: Fortran tests verifying implicit data
generation through bbc with both HLFIR and FIR
- acc-implicit-data-derived-type-member.F90: Tests correct ordering of
parent/child data clause operations for derived type members
- acc-implicit-copy-reduction.fir: Tests enable-implicit-reduction-copy
flag controlling whether reduction variables use copy or firstprivate

This enables proper testing of implicit data clause generation through
the flang optimizer pipeline for OpenACC directives.

Author: razvanlupusoru

flang/include/flang/Optimizer/OpenACC/Analysis/FIROpenACCSupportAnalysis.h

@@ -0,0 +1,51 @@
+//===- FIROpenACCSupportAnalysis.h - FIR OpenACCSupport Analysis ----------===//
+//
+// 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
+//
+//===----------------------------------------------------------------------===//
+//
+// This file defines the FIR-specific implementation of OpenACCSupport analysis.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef FORTRAN_OPTIMIZER_OPENACC_ANALYSIS_FIROPENACCSUPPORTANALYSIS_H
+#define FORTRAN_OPTIMIZER_OPENACC_ANALYSIS_FIROPENACCSUPPORTANALYSIS_H
+
+#include "mlir/Dialect/OpenACC/OpenACC.h"
+#include "mlir/IR/Value.h"
+#include <string>
+
+namespace fir {
+namespace acc {
+
+/// FIR-specific implementation for the OpenACCSupport analysis interface.
+///
+/// This class provides the custom implementations of the OpenACCSupport
+/// interface methods that are tailored to FIR's requirements and
+/// can handle FIR dialect operations and types.
+/// Its primary intent is to be registered with the OpenACCSupport analysis
+/// using setImplementation()
+///
+/// Usage:
+///   auto &support = getAnalysis<mlir::acc::OpenACCSupport>();
+///   support.setImplementation(fir::acc::FIROpenACCSupportAnalysis());
+///
+class FIROpenACCSupportAnalysis {
+public:
+  FIROpenACCSupportAnalysis() = default;
+
+  std::string getVariableName(mlir::Value v);
+
+  std::string getRecipeName(mlir::acc::RecipeKind kind, mlir::Type type,
+                            mlir::Value var);
+
+  mlir::InFlightDiagnostic emitNYI(mlir::Location loc,
+                                   const mlir::Twine &message);
+};
+
+} // namespace acc
+} // namespace fir
+
+#endif // FORTRAN_OPTIMIZER_OPENACC_ANALYSIS_FIROPENACCSUPPORTANALYSIS_H

flang/include/flang/Optimizer/OpenACC/Passes.h

@@ -13,6 +13,9 @@
 #ifndef FORTRAN_OPTIMIZER_OPENACC_PASSES_H
 #define FORTRAN_OPTIMIZER_OPENACC_PASSES_H
 
+#include "flang/Optimizer/Dialect/FIRDialect.h"
+#include "flang/Optimizer/HLFIR/HLFIRDialect.h"
+#include "mlir/Dialect/OpenACC/OpenACC.h"
 #include "mlir/IR/BuiltinOps.h"
 #include "mlir/Pass/Pass.h"
 #include "mlir/Pass/PassRegistry.h"
@@ -25,6 +28,7 @@ namespace acc {
 #define GEN_PASS_REGISTRATION
 #include "flang/Optimizer/OpenACC/Passes.h.inc"
 
+std::unique_ptr<mlir::Pass> createACCInitializeFIRAnalysesPass();
 std::unique_ptr<mlir::Pass> createACCRecipeBufferizationPass();
 
 } // namespace acc

flang/include/flang/Optimizer/OpenACC/Passes.td

@@ -11,6 +11,22 @@
 
 include "mlir/Pass/PassBase.td"
 
+def ACCInitializeFIRAnalyses
+    : Pass<"acc-initialize-fir-analyses", "mlir::ModuleOp"> {
+  let summary = "Initialize FIR analyses for OpenACC passes";
+  let description = [{
+    This pass initializes analyses that can be used by subsequent OpenACC passes
+    in the pipeline. It creates and caches the OpenACCSupport analysis with a
+    FIR-specific implementation that can handle FIR types and operations.
+    It also initializes FIR's AliasAnalysis for use in OpenACC passes.
+    This pass needs to rerun if any analyses were invalidated by MLIR's framework.
+  }];
+  // In addition to pre-registering the needed analyses, this pass also
+  // pre-registers the dialects that various OpenACC passes may generate.
+  let dependentDialects = ["fir::FIROpsDialect", "hlfir::hlfirDialect",
+      "mlir::acc::OpenACCDialect"];
+}
+
 def ACCRecipeBufferization
     : Pass<"fir-acc-recipe-bufferization", "mlir::ModuleOp"> {
   let summary = "Rewrite acc.*.recipe box values to ref<box> and update uses";

flang/include/flang/Optimizer/OpenACC/Support/FIROpenACCUtils.h

@@ -0,0 +1,57 @@
+//===- FIROpenACCUtils.h - FIR OpenACC Utilities ----------------*- C++ -*-===//
+//
+// 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
+//
+//===----------------------------------------------------------------------===//
+//
+// This file declares utility functions for FIR OpenACC support.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef FORTRAN_OPTIMIZER_OPENACC_SUPPORT_FIROPENACCUTILS_H
+#define FORTRAN_OPTIMIZER_OPENACC_SUPPORT_FIROPENACCUTILS_H
+
+#include "mlir/Dialect/OpenACC/OpenACC.h"
+#include "mlir/IR/Value.h"
+#include <string>
+
+namespace fir {
+namespace acc {
+
+/// Attempts to extract the variable name from a value by walking through
+/// FIR operations and looking for variable names.
+/// \param v The value to extract the variable name from
+/// \param preferDemangledName If true, prefers demangled/bindc names over
+///        mangled/unique names. If false, prefers mangled names.
+/// Returns empty string if no name is found.
+std::string getVariableName(mlir::Value v, bool preferDemangledName = true);
+
+/// Get the recipe name for a given recipe kind, FIR type, and optional
+/// variable. Uses FIR's type string representation with appropriate prefix. For
+/// firstprivate and reduction recipes, handles bounds suffix when all bounds
+/// are constant. For reduction recipes, embeds the operator name in the recipe.
+/// \param kind The recipe kind (private, firstprivate, or reduction)
+/// \param type The FIR type (must be a FIR type)
+/// \param var Optional variable value
+/// \param bounds Optional bounds for array sections (used for suffix
+/// generation)
+/// \param reductionOp Optional reduction operator (required for reduction
+/// recipes)
+/// \return The complete recipe name with all necessary suffixes
+std::string getRecipeName(mlir::acc::RecipeKind kind, mlir::Type type,
+                          mlir::Value var = nullptr,
+                          llvm::ArrayRef<mlir::Value> bounds = {},
+                          mlir::acc::ReductionOperator reductionOp =
+                              mlir::acc::ReductionOperator::AccNone);
+
+/// Check if all bounds are expressed with constant values.
+/// \param bounds Array of DataBoundsOp values to check
+/// \return true if all bounds have constant lowerbound/upperbound or extent
+bool areAllBoundsConstant(llvm::ArrayRef<mlir::Value> bounds);
+
+} // namespace acc
+} // namespace fir
+
+#endif // FORTRAN_OPTIMIZER_OPENACC_SUPPORT_FIROPENACCUTILS_H

flang/lib/Lower/OpenACC.cpp

@@ -28,6 +28,7 @@
 #include "flang/Optimizer/Builder/IntrinsicCall.h"
 #include "flang/Optimizer/Builder/Todo.h"
 #include "flang/Optimizer/Dialect/FIRType.h"
+#include "flang/Optimizer/OpenACC/Support/FIROpenACCUtils.h"
 #include "flang/Parser/parse-tree-visitor.h"
 #include "flang/Parser/parse-tree.h"
 #include "flang/Parser/tools.h"
@@ -1159,18 +1160,6 @@ bool isConstantBound(mlir::acc::DataBoundsOp &op) {
   return false;
 }
 
-/// Return true iff all the bounds are expressed with constant values.
-bool areAllBoundConstant(const llvm::SmallVector<mlir::Value> &bounds) {
-  for (auto bound : bounds) {
-    auto dataBound =
-        mlir::dyn_cast<mlir::acc::DataBoundsOp>(bound.getDefiningOp());
-    assert(dataBound && "Must be DataBoundOp operation");
-    if (!isConstantBound(dataBound))
-      return false;
-  }
-  return true;
-}
-
 static llvm::SmallVector<mlir::Value>
 genConstantBounds(fir::FirOpBuilder &builder, mlir::Location loc,
                   mlir::acc::DataBoundsOp &dataBound) {
@@ -1324,7 +1313,7 @@ mlir::acc::FirstprivateRecipeOp Fortran::lower::createOrGetFirstprivateRecipe(
   mlir::OpBuilder::InsertionGuard guard(builder);
   auto recipe = genRecipeOp<mlir::acc::FirstprivateRecipeOp>(
       builder, mod, recipeName, loc, ty);
-  bool allConstantBound = areAllBoundConstant(bounds);
+  bool allConstantBound = fir::acc::areAllBoundsConstant(bounds);
   auto [source, destination] = genRecipeCombinerOrCopyRegion(
       builder, loc, ty, recipe.getCopyRegion(), bounds, allConstantBound);
 
@@ -1358,33 +1347,6 @@ mlir::acc::FirstprivateRecipeOp Fortran::lower::createOrGetFirstprivateRecipe(
   return recipe;
 }
 
-/// Get a string representation of the bounds.
-std::string getBoundsString(llvm::SmallVector<mlir::Value> &bounds) {
-  std::stringstream boundStr;
-  if (!bounds.empty())
-    boundStr << "_section_";
-  llvm::interleave(
-      bounds,
-      [&](mlir::Value bound) {
-        auto boundsOp =
-            mlir::cast<mlir::acc::DataBoundsOp>(bound.getDefiningOp());
-        if (boundsOp.getLowerbound() &&
-            fir::getIntIfConstant(boundsOp.getLowerbound()) &&
-            boundsOp.getUpperbound() &&
-            fir::getIntIfConstant(boundsOp.getUpperbound())) {
-          boundStr << "lb" << *fir::getIntIfConstant(boundsOp.getLowerbound())
-                   << ".ub" << *fir::getIntIfConstant(boundsOp.getUpperbound());
-        } else if (boundsOp.getExtent() &&
-                   fir::getIntIfConstant(boundsOp.getExtent())) {
-          boundStr << "ext" << *fir::getIntIfConstant(boundsOp.getExtent());
-        } else {
-          boundStr << "?";
-        }
-      },
-      [&] { boundStr << "x"; });
-  return boundStr.str();
-}
-
 /// Rebuild the array type from the acc.bounds operation with constant
 /// lowerbound/upperbound or extent.
 mlir::Type getTypeFromBounds(llvm::SmallVector<mlir::Value> &bounds,
@@ -1458,9 +1420,8 @@ static void genPrivatizationRecipes(
     RecipeOp recipe;
     mlir::Type retTy = getTypeFromBounds(bounds, info.addr.getType());
     if constexpr (std::is_same_v<RecipeOp, mlir::acc::PrivateRecipeOp>) {
-      std::string recipeName =
-          fir::getTypeAsString(retTy, converter.getKindMap(),
-                               Fortran::lower::privatizationRecipePrefix);
+      std::string recipeName = fir::acc::getRecipeName(
+          mlir::acc::RecipeKind::private_recipe, retTy, info.addr, bounds);
       recipe = Fortran::lower::createOrGetPrivateRecipe(builder, recipeName,
                                                         operandLocation, retTy);
       auto op = createDataEntryOp<mlir::acc::PrivateOp>(
@@ -1474,10 +1435,8 @@ static void genPrivatizationRecipes(
         symbolPairs->emplace_back(op.getAccVar(),
                                   Fortran::semantics::SymbolRef(symbol));
     } else {
-      std::string suffix =
-          areAllBoundConstant(bounds) ? getBoundsString(bounds) : "";
-      std::string recipeName = fir::getTypeAsString(
-          retTy, converter.getKindMap(), "firstprivatization" + suffix);
+      std::string recipeName = fir::acc::getRecipeName(
+          mlir::acc::RecipeKind::firstprivate_recipe, retTy, info.addr, bounds);
       recipe = Fortran::lower::createOrGetFirstprivateRecipe(
           builder, recipeName, operandLocation, retTy, bounds);
       auto op = createDataEntryOp<mlir::acc::FirstprivateOp>(
@@ -1623,7 +1582,7 @@ mlir::acc::ReductionRecipeOp Fortran::lower::createOrGetReductionRecipe(
   mlir::OpBuilder::InsertionGuard guard(builder);
   auto recipe = genRecipeOp<mlir::acc::ReductionRecipeOp>(
       builder, mod, recipeName, loc, ty, op);
-  bool allConstantBound = areAllBoundConstant(bounds);
+  bool allConstantBound = fir::acc::areAllBoundsConstant(bounds);
 
   auto [dest, src] = genRecipeCombinerOrCopyRegion(
       builder, loc, ty, recipe.getCombinerRegion(), bounds, allConstantBound);
@@ -1708,15 +1667,12 @@ genReductions(const Fortran::parser::AccObjectListWithReduction &objectList,
         mlir::acc::DataClause::acc_reduction, info.addr.getType(), async,
         asyncDeviceTypes, asyncOnlyDeviceTypes, /*unwrapBoxAddr=*/true);
     mlir::Type ty = op.getAccVar().getType();
-    if (!areAllBoundConstant(bounds) ||
+    if (!fir::acc::areAllBoundsConstant(bounds) ||
         fir::isAssumedShape(info.addr.getType()) ||
         fir::isAllocatableOrPointerArray(info.addr.getType()))
       ty = info.addr.getType();
-    std::string suffix =
-        areAllBoundConstant(bounds) ? getBoundsString(bounds) : "";
-    std::string recipeName = fir::getTypeAsString(
-        ty, converter.getKindMap(),
-        ("reduction_" + stringifyReductionOperator(mlirOp)).str() + suffix);
+    std::string recipeName = fir::acc::getRecipeName(
+        mlir::acc::RecipeKind::reduction_recipe, ty, info.addr, bounds, mlirOp);
 
     mlir::acc::ReductionRecipeOp recipe =
         Fortran::lower::createOrGetReductionRecipe(
@@ -1961,9 +1917,8 @@ static void privatizeIv(
   }
 
   if (privateOp == nullptr) {
-    std::string recipeName =
-        fir::getTypeAsString(ivValue.getType(), converter.getKindMap(),
-                             Fortran::lower::privatizationRecipePrefix);
+    std::string recipeName = fir::acc::getRecipeName(
+        mlir::acc::RecipeKind::private_recipe, ivValue.getType(), ivValue, {});
     auto recipe = Fortran::lower::createOrGetPrivateRecipe(
         builder, recipeName, loc, ivValue.getType());
 

flang/lib/Optimizer/OpenACC/Analysis/CMakeLists.txt

@@ -0,0 +1,22 @@
+add_flang_library(FIROpenACCAnalysis
+  FIROpenACCSupportAnalysis.cpp
+
+  DEPENDS
+  FIRAnalysis
+  FIRDialect
+  FIROpenACCSupport
+  HLFIRDialect
+
+  LINK_LIBS
+  FIRAnalysis
+  FIRDialect
+  FIROpenACCSupport
+  HLFIRDialect
+
+  MLIR_DEPS
+  MLIROpenACCDialect
+
+  MLIR_LIBS
+  MLIROpenACCDialect
+)
+

flang/lib/Optimizer/OpenACC/Analysis/FIROpenACCSupportAnalysis.cpp

@@ -0,0 +1,40 @@
+//===- FIROpenACCSupportAnalysis.cpp - FIR OpenACCSupport Analysis -------===//
+//
+// 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
+//
+//===----------------------------------------------------------------------===//
+//
+// This file implements the FIR-specific OpenACCSupport analysis.
+//
+//===----------------------------------------------------------------------===//
+
+#include "flang/Optimizer/OpenACC/Analysis/FIROpenACCSupportAnalysis.h"
+#include "flang/Optimizer/Builder/Todo.h"
+#include "flang/Optimizer/OpenACC/Support/FIROpenACCUtils.h"
+
+using namespace mlir;
+
+namespace fir {
+namespace acc {
+
+std::string FIROpenACCSupportAnalysis::getVariableName(Value v) {
+  return fir::acc::getVariableName(v, /*preferDemangledName=*/true);
+}
+
+std::string FIROpenACCSupportAnalysis::getRecipeName(mlir::acc::RecipeKind kind,
+                                                     Type type, Value var) {
+  return fir::acc::getRecipeName(kind, type, var);
+}
+
+mlir::InFlightDiagnostic
+FIROpenACCSupportAnalysis::emitNYI(Location loc, const Twine &message) {
+  TODO(loc, message);
+  // Should be unreachable, but we return an actual diagnostic
+  // to satisfy the interface.
+  return mlir::emitError(loc, "not yet implemented: " + message.str());
+}
+
+} // namespace acc
+} // namespace fir

flang/lib/Optimizer/OpenACC/CMakeLists.txt

@@ -1,2 +1,3 @@
+add_subdirectory(Analysis)
 add_subdirectory(Support)
 add_subdirectory(Transforms)

flang/lib/Optimizer/OpenACC/Support/CMakeLists.txt

@@ -4,6 +4,7 @@ add_flang_library(FIROpenACCSupport
   FIROpenACCAttributes.cpp
   FIROpenACCOpsInterfaces.cpp
   FIROpenACCTypeInterfaces.cpp
+  FIROpenACCUtils.cpp
   RegisterOpenACCExtensions.cpp
 
   DEPENDS