[flang] Feature list plugin

Plugin that counts the number of times each tree node occurs in a given program.  Used for test coverage.

> One thing we need...is a way to determine what features a code uses. Preferably we would also be able to determine if they are implemented or not. Just the former could be done with a visitor for the parse tree. For the latter we would continue compilation and somehow ignore todo errors but collect them - @jdoerfert

Reviewed By: jdoerfert

Differential Revision: https://reviews.llvm.org/D143704

5 files changed, 933 insertions, 0 deletions

diff --git a/flang/examples/CMakeLists.txt b/flang/examples/CMakeLists.txt
index 23fea3920efb..8cc66ddbbbb0 100644
--- a/flang/examples/CMakeLists.txt
+++ b/flang/examples/CMakeLists.txt
@@ -1,3 +1,4 @@
 add_subdirectory(ExternalHelloWorld)
 add_subdirectory(PrintFlangFunctionNames)
 add_subdirectory(FlangOmpReport)
+add_subdirectory(FeatureList)
diff --git a/flang/examples/FeatureList/CMakeLists.txt b/flang/examples/FeatureList/CMakeLists.txt
new file mode 100644
index 000000000000..a5352f56cdd4
--- /dev/null
+++ b/flang/examples/FeatureList/CMakeLists.txt
@@ -0,0 +1,7 @@
+add_llvm_library(flangFeatureList
+    MODULE
+    FeatureList.cpp
+
+    DEPENDS
+    flangFrontend
+)
diff --git a/flang/examples/FeatureList/FeatureList.cpp b/flang/examples/FeatureList/FeatureList.cpp
new file mode 100644
index 000000000000..7d7e63e148bc
--- /dev/null
+++ b/flang/examples/FeatureList/FeatureList.cpp
@@ -0,0 +1,761 @@
+//===-- FeatureList.cpp ---------------------------------------------------===//
+//
+// 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
+//
+//===----------------------------------------------------------------------===//
+//
+// A plugin that counts the amount of times a particular parse tree node
+// occurs.  This plugin should cover each feature covered in dump-parse-tree.h
+//
+//===----------------------------------------------------------------------===//
+
+#include "flang/Frontend/FrontendActions.h"
+#include "flang/Frontend/FrontendPluginRegistry.h"
+#include "flang/Parser/parse-tree-visitor.h"
+#include "flang/Parser/parse-tree.h"
+#include "flang/Parser/parsing.h"
+
+#include <map>
+
+using namespace Fortran::frontend;
+using namespace Fortran::parser;
+using namespace Fortran;
+
+#define READ_FEATURE_CUST(classname, n) \
+  bool Pre(const classname &) { \
+    record(#n); \
+    return true; \
+  } \
+  void Post(const classname &) {}
+
+#define READ_FEATURE(classname) READ_FEATURE_CUST(classname, classname)
+
+struct NodeVisitor {
+private:
+  std::map<const char *, unsigned int> frequencies;
+
+  void record(const char *name) {
+    const auto [it, ins] = frequencies.insert({name, 1});
+    if (!ins) {
+      frequencies[name] = it->second + 1;
+    }
+  }
+
+public:
+  const std::map<const char *, unsigned int> &getFrequencies() const {
+    return frequencies;
+  }
+
+  READ_FEATURE_CUST(format::ControlEditDesc, ControlEditDesc)
+  READ_FEATURE_CUST(format::DerivedTypeDataEditDesc, DerivedTypeDataEditDesc)
+  READ_FEATURE_CUST(format::FormatItem, FormatItem)
+  READ_FEATURE_CUST(format::FormatSpecification, FormatSpecification)
+  READ_FEATURE_CUST(
+      format::IntrinsicTypeDataEditDesc, IntrinsicTypeDataEditDesc)
+  READ_FEATURE(Abstract)
+  READ_FEATURE(AccAtomicCapture)
+  READ_FEATURE(AccAtomicCapture::Stmt1)
+  READ_FEATURE(AccAtomicCapture::Stmt2)
+  READ_FEATURE(AccAtomicRead)
+  READ_FEATURE(AccAtomicUpdate)
+  READ_FEATURE(AccAtomicWrite)
+  READ_FEATURE(AccBeginBlockDirective)
+  READ_FEATURE(AccBeginCombinedDirective)
+  READ_FEATURE(AccBeginLoopDirective)
+  READ_FEATURE(AccBlockDirective)
+  READ_FEATURE(AccClause)
+  READ_FEATURE(AccBindClause)
+  READ_FEATURE(AccDefaultClause)
+  READ_FEATURE(AccClauseList)
+  READ_FEATURE(AccCombinedDirective)
+  READ_FEATURE(AccDataModifier)
+  READ_FEATURE(AccDataModifier::Modifier)
+  READ_FEATURE(AccDeclarativeDirective)
+  READ_FEATURE(AccEndAtomic)
+  READ_FEATURE(AccEndBlockDirective)
+  READ_FEATURE(AccEndCombinedDirective)
+  READ_FEATURE(AccGangArgument)
+  READ_FEATURE(AccObject)
+  READ_FEATURE(AccObjectList)
+  READ_FEATURE(AccObjectListWithModifier)
+  READ_FEATURE(AccObjectListWithReduction)
+  READ_FEATURE(AccReductionOperator)
+  READ_FEATURE(AccReductionOperator::Operator)
+  READ_FEATURE(AccSizeExpr)
+  READ_FEATURE(AccSizeExprList)
+  READ_FEATURE(AccSelfClause)
+  READ_FEATURE(AccStandaloneDirective)
+  READ_FEATURE(AccDeviceTypeExpr)
+  READ_FEATURE(AccDeviceTypeExprList)
+  READ_FEATURE(AccTileExpr)
+  READ_FEATURE(AccTileExprList)
+  READ_FEATURE(AccLoopDirective)
+  READ_FEATURE(AccWaitArgument)
+  READ_FEATURE(AcImpliedDo)
+  READ_FEATURE(AcImpliedDoControl)
+  READ_FEATURE(AcValue)
+  READ_FEATURE(AccessStmt)
+  READ_FEATURE(AccessId)
+  READ_FEATURE(AccessSpec)
+  READ_FEATURE(AccessSpec::Kind)
+  READ_FEATURE(AcSpec)
+  READ_FEATURE(ActionStmt)
+  READ_FEATURE(ActualArg)
+  READ_FEATURE(ActualArg::PercentRef)
+  READ_FEATURE(ActualArg::PercentVal)
+  READ_FEATURE(ActualArgSpec)
+  READ_FEATURE(AcValue::Triplet)
+  READ_FEATURE(AllocOpt)
+  READ_FEATURE(AllocOpt::Mold)
+  READ_FEATURE(AllocOpt::Source)
+  READ_FEATURE(Allocatable)
+  READ_FEATURE(AllocatableStmt)
+  READ_FEATURE(AllocateCoarraySpec)
+  READ_FEATURE(AllocateObject)
+  READ_FEATURE(AllocateShapeSpec)
+  READ_FEATURE(AllocateStmt)
+  READ_FEATURE(Allocation)
+  READ_FEATURE(AltReturnSpec)
+  READ_FEATURE(ArithmeticIfStmt)
+  READ_FEATURE(ArrayConstructor)
+  READ_FEATURE(ArrayElement)
+  READ_FEATURE(ArraySpec)
+  READ_FEATURE(AssignStmt)
+  READ_FEATURE(AssignedGotoStmt)
+  READ_FEATURE(AssignmentStmt)
+  READ_FEATURE(AssociateConstruct)
+  READ_FEATURE(AssociateStmt)
+  READ_FEATURE(Association)
+  READ_FEATURE(AssumedImpliedSpec)
+  READ_FEATURE(AssumedRankSpec)
+  READ_FEATURE(AssumedShapeSpec)
+  READ_FEATURE(AssumedSizeSpec)
+  READ_FEATURE(Asynchronous)
+  READ_FEATURE(AsynchronousStmt)
+  READ_FEATURE(AttrSpec)
+  READ_FEATURE(BOZLiteralConstant)
+  READ_FEATURE(BackspaceStmt)
+  READ_FEATURE(BasedPointer)
+  READ_FEATURE(BasedPointerStmt)
+  READ_FEATURE(BindAttr)
+  READ_FEATURE(BindAttr::Deferred)
+  READ_FEATURE(BindAttr::Non_Overridable)
+  READ_FEATURE(BindEntity)
+  READ_FEATURE(BindEntity::Kind)
+  READ_FEATURE(BindStmt)
+  READ_FEATURE(Block)
+  READ_FEATURE(BlockConstruct)
+  READ_FEATURE(BlockData)
+  READ_FEATURE(BlockDataStmt)
+  READ_FEATURE(BlockSpecificationPart)
+  READ_FEATURE(BlockStmt)
+  READ_FEATURE(BoundsRemapping)
+  READ_FEATURE(BoundsSpec)
+  READ_FEATURE(Call)
+  READ_FEATURE(CallStmt)
+  READ_FEATURE(CaseConstruct)
+  READ_FEATURE(CaseConstruct::Case)
+  READ_FEATURE(CaseSelector)
+  READ_FEATURE(CaseStmt)
+  READ_FEATURE(CaseValueRange)
+  READ_FEATURE(CaseValueRange::Range)
+  READ_FEATURE(ChangeTeamConstruct)
+  READ_FEATURE(ChangeTeamStmt)
+  READ_FEATURE(CharLength)
+  READ_FEATURE(CharLiteralConstant)
+  READ_FEATURE(CharLiteralConstantSubstring)
+  READ_FEATURE(CharSelector)
+  READ_FEATURE(CharSelector::LengthAndKind)
+  READ_FEATURE(CloseStmt)
+  READ_FEATURE(CloseStmt::CloseSpec)
+  READ_FEATURE(CoarrayAssociation)
+  READ_FEATURE(CoarraySpec)
+  READ_FEATURE(CodimensionDecl)
+  READ_FEATURE(CodimensionStmt)
+  READ_FEATURE(CoindexedNamedObject)
+  READ_FEATURE(CommonBlockObject)
+  READ_FEATURE(CommonStmt)
+  READ_FEATURE(CommonStmt::Block)
+  READ_FEATURE(CompilerDirective)
+  READ_FEATURE(CompilerDirective::IgnoreTKR)
+  READ_FEATURE(CompilerDirective::LoopCount)
+  READ_FEATURE(CompilerDirective::NameValue)
+  READ_FEATURE(ComplexLiteralConstant)
+  READ_FEATURE(ComplexPart)
+  READ_FEATURE(ComponentArraySpec)
+  READ_FEATURE(ComponentAttrSpec)
+  READ_FEATURE(ComponentDataSource)
+  READ_FEATURE(ComponentDecl)
+  READ_FEATURE(FillDecl)
+  READ_FEATURE(ComponentOrFill)
+  READ_FEATURE(ComponentDefStmt)
+  READ_FEATURE(ComponentSpec)
+  READ_FEATURE(ComputedGotoStmt)
+  READ_FEATURE(ConcurrentControl)
+  READ_FEATURE(ConcurrentHeader)
+  READ_FEATURE(ConnectSpec)
+  READ_FEATURE(ConnectSpec::CharExpr)
+  READ_FEATURE(ConnectSpec::CharExpr::Kind)
+  READ_FEATURE(ConnectSpec::Newunit)
+  READ_FEATURE(ConnectSpec::Recl)
+  READ_FEATURE(ContainsStmt)
+  READ_FEATURE(Contiguous)
+  READ_FEATURE(ContiguousStmt)
+  READ_FEATURE(ContinueStmt)
+  READ_FEATURE(CriticalConstruct)
+  READ_FEATURE(CriticalStmt)
+  READ_FEATURE(CycleStmt)
+  READ_FEATURE(DataComponentDefStmt)
+  READ_FEATURE(DataIDoObject)
+  READ_FEATURE(DataImpliedDo)
+  READ_FEATURE(DataRef)
+  READ_FEATURE(DataStmt)
+  READ_FEATURE(DataStmtConstant)
+  READ_FEATURE(DataStmtObject)
+  READ_FEATURE(DataStmtRepeat)
+  READ_FEATURE(DataStmtSet)
+  READ_FEATURE(DataStmtValue)
+  READ_FEATURE(DeallocateStmt)
+  READ_FEATURE(DeclarationConstruct)
+  READ_FEATURE(DeclarationTypeSpec)
+  READ_FEATURE(DeclarationTypeSpec::Class)
+  READ_FEATURE(DeclarationTypeSpec::ClassStar)
+  READ_FEATURE(DeclarationTypeSpec::Record)
+  READ_FEATURE(DeclarationTypeSpec::Type)
+  READ_FEATURE(DeclarationTypeSpec::TypeStar)
+  READ_FEATURE(Default)
+  READ_FEATURE(DeferredCoshapeSpecList)
+  READ_FEATURE(DeferredShapeSpecList)
+  READ_FEATURE(DefinedOpName)
+  READ_FEATURE(DefinedOperator)
+  READ_FEATURE(DefinedOperator::IntrinsicOperator)
+  READ_FEATURE(DerivedTypeDef)
+  READ_FEATURE(DerivedTypeSpec)
+  READ_FEATURE(DerivedTypeStmt)
+  READ_FEATURE(Designator)
+  READ_FEATURE(DimensionStmt)
+  READ_FEATURE(DimensionStmt::Declaration)
+  READ_FEATURE(DoConstruct)
+  READ_FEATURE(DummyArg)
+  READ_FEATURE(ElseIfStmt)
+  READ_FEATURE(ElseStmt)
+  READ_FEATURE(ElsewhereStmt)
+  READ_FEATURE(EndAssociateStmt)
+  READ_FEATURE(EndBlockDataStmt)
+  READ_FEATURE(EndBlockStmt)
+  READ_FEATURE(EndChangeTeamStmt)
+  READ_FEATURE(EndCriticalStmt)
+  READ_FEATURE(EndDoStmt)
+  READ_FEATURE(EndEnumStmt)
+  READ_FEATURE(EndForallStmt)
+  READ_FEATURE(EndFunctionStmt)
+  READ_FEATURE(EndIfStmt)
+  READ_FEATURE(EndInterfaceStmt)
+  READ_FEATURE(EndLabel)
+  READ_FEATURE(EndModuleStmt)
+  READ_FEATURE(EndMpSubprogramStmt)
+  READ_FEATURE(EndProgramStmt)
+  READ_FEATURE(EndSelectStmt)
+  READ_FEATURE(EndSubmoduleStmt)
+  READ_FEATURE(EndSubroutineStmt)
+  READ_FEATURE(EndTypeStmt)
+  READ_FEATURE(EndWhereStmt)
+  READ_FEATURE(EndfileStmt)
+  READ_FEATURE(EntityDecl)
+  READ_FEATURE(EntryStmt)
+  READ_FEATURE(EnumDef)
+  READ_FEATURE(EnumDefStmt)
+  READ_FEATURE(Enumerator)
+  READ_FEATURE(EnumeratorDefStmt)
+  READ_FEATURE(EorLabel)
+  READ_FEATURE(EquivalenceObject)
+  READ_FEATURE(EquivalenceStmt)
+  READ_FEATURE(ErrLabel)
+  READ_FEATURE(ErrorRecovery)
+  READ_FEATURE(EventPostStmt)
+  READ_FEATURE(EventWaitStmt)
+  READ_FEATURE(EventWaitStmt::EventWaitSpec)
+  READ_FEATURE(ExecutableConstruct)
+  READ_FEATURE(ExecutionPart)
+  READ_FEATURE(ExecutionPartConstruct)
+  READ_FEATURE(ExitStmt)
+  READ_FEATURE(ExplicitCoshapeSpec)
+  READ_FEATURE(ExplicitShapeSpec)
+  READ_FEATURE(Expr)
+  READ_FEATURE(Expr::Parentheses)
+  READ_FEATURE(Expr::UnaryPlus)
+  READ_FEATURE(Expr::Negate)
+  READ_FEATURE(Expr::NOT)
+  READ_FEATURE(Expr::PercentLoc)
+  READ_FEATURE(Expr::DefinedUnary)
+  READ_FEATURE(Expr::Power)
+  READ_FEATURE(Expr::Multiply)
+  READ_FEATURE(Expr::Divide)
+  READ_FEATURE(Expr::Add)
+  READ_FEATURE(Expr::Subtract)
+  READ_FEATURE(Expr::Concat)
+  READ_FEATURE(Expr::LT)
+  READ_FEATURE(Expr::LE)
+  READ_FEATURE(Expr::EQ)
+  READ_FEATURE(Expr::NE)
+  READ_FEATURE(Expr::GE)
+  READ_FEATURE(Expr::GT)
+  READ_FEATURE(Expr::AND)
+  READ_FEATURE(Expr::OR)
+  READ_FEATURE(Expr::EQV)
+  READ_FEATURE(Expr::NEQV)
+  READ_FEATURE(Expr::DefinedBinary)
+  READ_FEATURE(Expr::ComplexConstructor)
+  READ_FEATURE(External)
+  READ_FEATURE(ExternalStmt)
+  READ_FEATURE(FailImageStmt)
+  READ_FEATURE(FileUnitNumber)
+  READ_FEATURE(FinalProcedureStmt)
+  READ_FEATURE(FlushStmt)
+  READ_FEATURE(ForallAssignmentStmt)
+  READ_FEATURE(ForallBodyConstruct)
+  READ_FEATURE(ForallConstruct)
+  READ_FEATURE(ForallConstructStmt)
+  READ_FEATURE(ForallStmt)
+  READ_FEATURE(FormTeamStmt)
+  READ_FEATURE(FormTeamStmt::FormTeamSpec)
+  READ_FEATURE(Format)
+  READ_FEATURE(FormatStmt)
+  READ_FEATURE(FunctionReference)
+  READ_FEATURE(FunctionStmt)
+  READ_FEATURE(FunctionSubprogram)
+  READ_FEATURE(GenericSpec)
+  READ_FEATURE(GenericSpec::Assignment)
+  READ_FEATURE(GenericSpec::ReadFormatted)
+  READ_FEATURE(GenericSpec::ReadUnformatted)
+  READ_FEATURE(GenericSpec::WriteFormatted)
+  READ_FEATURE(GenericSpec::WriteUnformatted)
+  READ_FEATURE(GenericStmt)
+  READ_FEATURE(GotoStmt)
+  READ_FEATURE(HollerithLiteralConstant)
+  READ_FEATURE(IdExpr)
+  READ_FEATURE(IdVariable)
+  READ_FEATURE(IfConstruct)
+  READ_FEATURE(IfConstruct::ElseBlock)
+  READ_FEATURE(IfConstruct::ElseIfBlock)
+  READ_FEATURE(IfStmt)
+  READ_FEATURE(IfThenStmt)
+  READ_FEATURE(TeamValue)
+  READ_FEATURE(ImageSelector)
+  READ_FEATURE(ImageSelectorSpec)
+  READ_FEATURE(ImageSelectorSpec::Stat)
+  READ_FEATURE(ImageSelectorSpec::Team_Number)
+  READ_FEATURE(ImplicitPart)
+  READ_FEATURE(ImplicitPartStmt)
+  READ_FEATURE(ImplicitSpec)
+  READ_FEATURE(ImplicitStmt)
+  READ_FEATURE(ImplicitStmt::ImplicitNoneNameSpec)
+  READ_FEATURE(ImpliedShapeSpec)
+  READ_FEATURE(ImportStmt)
+  READ_FEATURE(Initialization)
+  READ_FEATURE(InputImpliedDo)
+  READ_FEATURE(InputItem)
+  READ_FEATURE(InquireSpec)
+  READ_FEATURE(InquireSpec::CharVar)
+  READ_FEATURE(InquireSpec::CharVar::Kind)
+  READ_FEATURE(InquireSpec::IntVar)
+  READ_FEATURE(InquireSpec::IntVar::Kind)
+  READ_FEATURE(InquireSpec::LogVar)
+  READ_FEATURE(InquireSpec::LogVar::Kind)
+  READ_FEATURE(InquireStmt)
+  READ_FEATURE(InquireStmt::Iolength)
+  READ_FEATURE(IntegerTypeSpec)
+  READ_FEATURE(IntentSpec)
+  READ_FEATURE(IntentSpec::Intent)
+  READ_FEATURE(IntentStmt)
+  READ_FEATURE(InterfaceBlock)
+  READ_FEATURE(InterfaceBody)
+  READ_FEATURE(InterfaceBody::Function)
+  READ_FEATURE(InterfaceBody::Subroutine)
+  READ_FEATURE(InterfaceSpecification)
+  READ_FEATURE(InterfaceStmt)
+  READ_FEATURE(InternalSubprogram)
+  READ_FEATURE(InternalSubprogramPart)
+  READ_FEATURE(Intrinsic)
+  READ_FEATURE(IntrinsicStmt)
+  READ_FEATURE(IntrinsicTypeSpec)
+  READ_FEATURE(IntrinsicTypeSpec::Character)
+  READ_FEATURE(IntrinsicTypeSpec::Complex)
+  READ_FEATURE(IntrinsicTypeSpec::DoubleComplex)
+  READ_FEATURE(IntrinsicTypeSpec::DoublePrecision)
+  READ_FEATURE(IntrinsicTypeSpec::Logical)
+  READ_FEATURE(IntrinsicTypeSpec::Real)
+  READ_FEATURE(IoControlSpec)
+  READ_FEATURE(IoControlSpec::Asynchronous)
+  READ_FEATURE(IoControlSpec::CharExpr)
+  READ_FEATURE(IoControlSpec::CharExpr::Kind)
+  READ_FEATURE(IoControlSpec::Pos)
+  READ_FEATURE(IoControlSpec::Rec)
+  READ_FEATURE(IoControlSpec::Size)
+  READ_FEATURE(IoUnit)
+  READ_FEATURE(Keyword)
+  READ_FEATURE(KindParam)
+  READ_FEATURE(KindSelector)
+  READ_FEATURE(KindSelector::StarSize)
+  READ_FEATURE(LabelDoStmt)
+  READ_FEATURE(LanguageBindingSpec)
+  READ_FEATURE(LengthSelector)
+  READ_FEATURE(LetterSpec)
+  READ_FEATURE(LiteralConstant)
+  READ_FEATURE(IntLiteralConstant)
+  READ_FEATURE(LocalitySpec)
+  READ_FEATURE(LocalitySpec::DefaultNone)
+  READ_FEATURE(LocalitySpec::Local)
+  READ_FEATURE(LocalitySpec::LocalInit)
+  READ_FEATURE(LocalitySpec::Shared)
+  READ_FEATURE(LockStmt)
+  READ_FEATURE(LockStmt::LockStat)
+  READ_FEATURE(LogicalLiteralConstant)
+  READ_FEATURE(LoopControl)
+  READ_FEATURE(LoopControl::Concurrent)
+  READ_FEATURE(MainProgram)
+  READ_FEATURE(Map)
+  READ_FEATURE(Map::EndMapStmt)
+  READ_FEATURE(Map::MapStmt)
+  READ_FEATURE(MaskedElsewhereStmt)
+  READ_FEATURE(Module)
+  READ_FEATURE(ModuleStmt)
+  READ_FEATURE(ModuleSubprogram)
+  READ_FEATURE(ModuleSubprogramPart)
+  READ_FEATURE(MpSubprogramStmt)
+  READ_FEATURE(MsgVariable)
+  READ_FEATURE(Name)
+  READ_FEATURE(NamedConstant)
+  READ_FEATURE(NamedConstantDef)
+  READ_FEATURE(NamelistStmt)
+  READ_FEATURE(NamelistStmt::Group)
+  READ_FEATURE(NonLabelDoStmt)
+  READ_FEATURE(NoPass)
+  READ_FEATURE(NullifyStmt)
+  READ_FEATURE(NullInit)
+  READ_FEATURE(ObjectDecl)
+  READ_FEATURE(OldParameterStmt)
+  READ_FEATURE(OmpAlignedClause)
+  READ_FEATURE(OmpAtomic)
+  READ_FEATURE(OmpAtomicCapture)
+  READ_FEATURE(OmpAtomicCapture::Stmt1)
+  READ_FEATURE(OmpAtomicCapture::Stmt2)
+  READ_FEATURE(OmpAtomicRead)
+  READ_FEATURE(OmpAtomicUpdate)
+  READ_FEATURE(OmpAtomicWrite)
+  READ_FEATURE(OmpBeginBlockDirective)
+  READ_FEATURE(OmpBeginLoopDirective)
+  READ_FEATURE(OmpBeginSectionsDirective)
+  READ_FEATURE(OmpBlockDirective)
+  READ_FEATURE(OmpCancelType)
+  READ_FEATURE(OmpCancelType::Type)
+  READ_FEATURE(OmpClause)
+  READ_FEATURE(OmpClauseList)
+  READ_FEATURE(OmpCriticalDirective)
+  READ_FEATURE(OmpDeclareTargetSpecifier)
+  READ_FEATURE(OmpDeclareTargetWithClause)
+  READ_FEATURE(OmpDeclareTargetWithList)
+  READ_FEATURE(OmpDefaultClause)
+  READ_FEATURE(OmpDefaultClause::Type)
+  READ_FEATURE(OmpDefaultmapClause)
+  READ_FEATURE(OmpDefaultmapClause::ImplicitBehavior)
+  READ_FEATURE(OmpDefaultmapClause::VariableCategory)
+  READ_FEATURE(OmpDependClause)
+  READ_FEATURE(OmpDependClause::InOut)
+  READ_FEATURE(OmpDependClause::Sink)
+  READ_FEATURE(OmpDependClause::Source)
+  READ_FEATURE(OmpDependenceType)
+  READ_FEATURE(OmpDependenceType::Type)
+  READ_FEATURE(OmpDependSinkVec)
+  READ_FEATURE(OmpDependSinkVecLength)
+  READ_FEATURE(OmpEndAtomic)
+  READ_FEATURE(OmpEndBlockDirective)
+  READ_FEATURE(OmpEndCriticalDirective)
+  READ_FEATURE(OmpEndLoopDirective)
+  READ_FEATURE(OmpEndSectionsDirective)
+  READ_FEATURE(OmpIfClause)
+  READ_FEATURE(OmpIfClause::DirectiveNameModifier)
+  READ_FEATURE(OmpLinearClause)
+  READ_FEATURE(OmpLinearClause::WithModifier)
+  READ_FEATURE(OmpLinearClause::WithoutModifier)
+  READ_FEATURE(OmpLinearModifier)
+  READ_FEATURE(OmpLinearModifier::Type)
+  READ_FEATURE(OmpLoopDirective)
+  READ_FEATURE(OmpMapClause)
+  READ_FEATURE(OmpMapType)
+  READ_FEATURE(OmpMapType::Always)
+  READ_FEATURE(OmpMapType::Type)
+  READ_FEATURE(OmpObject)
+  READ_FEATURE(OmpObjectList)
+  READ_FEATURE(OmpOrderClause)
+  READ_FEATURE(OmpOrderClause::Type)
+  READ_FEATURE(OmpOrderModifier)
+  READ_FEATURE(OmpOrderModifier::Kind)
+  READ_FEATURE(OmpProcBindClause)
+  READ_FEATURE(OmpProcBindClause::Type)
+  READ_FEATURE(OmpReductionClause)
+  READ_FEATURE(OmpInReductionClause)
+  READ_FEATURE(OmpReductionCombiner)
+  READ_FEATURE(OmpReductionCombiner::FunctionCombiner)
+  READ_FEATURE(OmpReductionInitializerClause)
+  READ_FEATURE(OmpReductionOperator)
+  READ_FEATURE(OmpAllocateClause)
+  READ_FEATURE(OmpAllocateClause::Allocator)
+  READ_FEATURE(OmpScheduleClause)
+  READ_FEATURE(OmpScheduleClause::ScheduleType)
+  READ_FEATURE(OmpDeviceClause)
+  READ_FEATURE(OmpDeviceClause::DeviceModifier)
+  READ_FEATURE(OmpDeviceTypeClause)
+  READ_FEATURE(OmpDeviceTypeClause::Type)
+  READ_FEATURE(OmpScheduleModifier)
+  READ_FEATURE(OmpScheduleModifier::Modifier1)
+  READ_FEATURE(OmpScheduleModifier::Modifier2)
+  READ_FEATURE(OmpScheduleModifierType)
+  READ_FEATURE(OmpScheduleModifierType::ModType)
+  READ_FEATURE(OmpSectionBlocks)
+  READ_FEATURE(OmpSectionsDirective)
+  READ_FEATURE(OmpSimpleStandaloneDirective)
+  READ_FEATURE(Only)
+  READ_FEATURE(OpenACCAtomicConstruct)
+  READ_FEATURE(OpenACCBlockConstruct)
+  READ_FEATURE(OpenACCCacheConstruct)
+  READ_FEATURE(OpenACCCombinedConstruct)
+  READ_FEATURE(OpenACCConstruct)
+  READ_FEATURE(OpenACCDeclarativeConstruct)
+  READ_FEATURE(OpenACCLoopConstruct)
+  READ_FEATURE(OpenACCRoutineConstruct)
+  READ_FEATURE(OpenACCStandaloneDeclarativeConstruct)
+  READ_FEATURE(OpenACCStandaloneConstruct)
+  READ_FEATURE(OpenACCWaitConstruct)
+  READ_FEATURE(OpenMPAtomicConstruct)
+  READ_FEATURE(OpenMPBlockConstruct)
+  READ_FEATURE(OpenMPCancelConstruct)
+  READ_FEATURE(OpenMPCancelConstruct::If)
+  READ_FEATURE(OpenMPCancellationPointConstruct)
+  READ_FEATURE(OpenMPConstruct)
+  READ_FEATURE(OpenMPCriticalConstruct)
+  READ_FEATURE(OpenMPDeclarativeAllocate)
+  READ_FEATURE(OpenMPDeclarativeConstruct)
+  READ_FEATURE(OpenMPDeclareReductionConstruct)
+  READ_FEATURE(OpenMPDeclareSimdConstruct)
+  READ_FEATURE(OpenMPDeclareTargetConstruct)
+  READ_FEATURE(OmpMemoryOrderClause)
+  READ_FEATURE(OmpAtomicClause)
+  READ_FEATURE(OmpAtomicClauseList)
+  READ_FEATURE(OmpAtomicDefaultMemOrderClause)
+  READ_FEATURE(OmpAtomicDefaultMemOrderClause::Type)
+  READ_FEATURE(OpenMPFlushConstruct)
+  READ_FEATURE(OpenMPLoopConstruct)
+  READ_FEATURE(OpenMPExecutableAllocate)
+  READ_FEATURE(OpenMPRequiresConstruct)
+  READ_FEATURE(OpenMPSimpleStandaloneConstruct)
+  READ_FEATURE(OpenMPStandaloneConstruct)
+  READ_FEATURE(OpenMPSectionConstruct)
+  READ_FEATURE(OpenMPSectionsConstruct)
+  READ_FEATURE(OpenMPThreadprivate)
+  READ_FEATURE(OpenStmt)
+  READ_FEATURE(Optional)
+  READ_FEATURE(OptionalStmt)
+  READ_FEATURE(OtherSpecificationStmt)
+  READ_FEATURE(OutputImpliedDo)
+  READ_FEATURE(OutputItem)
+  READ_FEATURE(Parameter)
+  READ_FEATURE(ParameterStmt)
+  READ_FEATURE(ParentIdentifier)
+  READ_FEATURE(Pass)
+  READ_FEATURE(PauseStmt)
+  READ_FEATURE(Pointer)
+  READ_FEATURE(PointerAssignmentStmt)
+  READ_FEATURE(PointerAssignmentStmt::Bounds)
+  READ_FEATURE(PointerDecl)
+  READ_FEATURE(PointerObject)
+  READ_FEATURE(PointerStmt)
+  READ_FEATURE(PositionOrFlushSpec)
+  READ_FEATURE(PrefixSpec)
+  READ_FEATURE(PrefixSpec::Elemental)
+  READ_FEATURE(PrefixSpec::Impure)
+  READ_FEATURE(PrefixSpec::Module)
+  READ_FEATURE(PrefixSpec::Non_Recursive)
+  READ_FEATURE(PrefixSpec::Pure)
+  READ_FEATURE(PrefixSpec::Recursive)
+  READ_FEATURE(PrintStmt)
+  READ_FEATURE(PrivateStmt)
+  READ_FEATURE(PrivateOrSequence)
+  READ_FEATURE(ProcAttrSpec)
+  READ_FEATURE(ProcComponentAttrSpec)
+  READ_FEATURE(ProcComponentDefStmt)
+  READ_FEATURE(ProcComponentRef)
+  READ_FEATURE(ProcDecl)
+  READ_FEATURE(ProcInterface)
+  READ_FEATURE(ProcPointerInit)
+  READ_FEATURE(ProcedureDeclarationStmt)
+  READ_FEATURE(ProcedureDesignator)
+  READ_FEATURE(ProcedureStmt)
+  READ_FEATURE(ProcedureStmt::Kind)
+  READ_FEATURE(Program)
+  READ_FEATURE(ProgramStmt)
+  READ_FEATURE(ProgramUnit)
+  READ_FEATURE(Protected)
+  READ_FEATURE(ProtectedStmt)
+  READ_FEATURE(ReadStmt)
+  READ_FEATURE(RealLiteralConstant)
+  READ_FEATURE(RealLiteralConstant::Real)
+  READ_FEATURE(Rename)
+  READ_FEATURE(Rename::Names)
+  READ_FEATURE(Rename::Operators)
+  READ_FEATURE(ReturnStmt)
+  READ_FEATURE(RewindStmt)
+  READ_FEATURE(Save)
+  READ_FEATURE(SaveStmt)
+  READ_FEATURE(SavedEntity)
+  READ_FEATURE(SavedEntity::Kind)
+  READ_FEATURE(SectionSubscript)
+  READ_FEATURE(SelectCaseStmt)
+  READ_FEATURE(SelectRankCaseStmt)
+  READ_FEATURE(SelectRankCaseStmt::Rank)
+  READ_FEATURE(SelectRankConstruct)
+  READ_FEATURE(SelectRankConstruct::RankCase)
+  READ_FEATURE(SelectRankStmt)
+  READ_FEATURE(SelectTypeConstruct)
+  READ_FEATURE(SelectTypeConstruct::TypeCase)
+  READ_FEATURE(SelectTypeStmt)
+  READ_FEATURE(Selector)
+  READ_FEATURE(SeparateModuleSubprogram)
+  READ_FEATURE(SequenceStmt)
+  READ_FEATURE(Sign)
+  READ_FEATURE(SignedComplexLiteralConstant)
+  READ_FEATURE(SignedIntLiteralConstant)
+  READ_FEATURE(SignedRealLiteralConstant)
+  READ_FEATURE(SpecificationConstruct)
+  READ_FEATURE(SpecificationExpr)
+  READ_FEATURE(SpecificationPart)
+  READ_FEATURE(Star)
+  READ_FEATURE(StatOrErrmsg)
+  READ_FEATURE(StatVariable)
+  READ_FEATURE(StatusExpr)
+  READ_FEATURE(StmtFunctionStmt)
+  READ_FEATURE(StopCode)
+  READ_FEATURE(StopStmt)
+  READ_FEATURE(StopStmt::Kind)
+  READ_FEATURE(StructureComponent)
+  READ_FEATURE(StructureConstructor)
+  READ_FEATURE(StructureDef)
+  READ_FEATURE(StructureDef::EndStructureStmt)
+  READ_FEATURE(StructureField)
+  READ_FEATURE(StructureStmt)
+  READ_FEATURE(Submodule)
+  READ_FEATURE(SubmoduleStmt)
+  READ_FEATURE(SubroutineStmt)
+  READ_FEATURE(SubroutineSubprogram)
+  READ_FEATURE(SubscriptTriplet)
+  READ_FEATURE(Substring)
+  READ_FEATURE(SubstringInquiry)
+  READ_FEATURE(SubstringRange)
+  READ_FEATURE(Suffix)
+  READ_FEATURE(SyncAllStmt)
+  READ_FEATURE(SyncImagesStmt)
+  READ_FEATURE(SyncImagesStmt::ImageSet)
+  READ_FEATURE(SyncMemoryStmt)
+  READ_FEATURE(SyncTeamStmt)
+  READ_FEATURE(Target)
+  READ_FEATURE(TargetStmt)
+  READ_FEATURE(TypeAttrSpec)
+  READ_FEATURE(TypeAttrSpec::BindC)
+  READ_FEATURE(TypeAttrSpec::Extends)
+  READ_FEATURE(TypeBoundGenericStmt)
+  READ_FEATURE(TypeBoundProcBinding)
+  READ_FEATURE(TypeBoundProcDecl)
+  READ_FEATURE(TypeBoundProcedurePart)
+  READ_FEATURE(TypeBoundProcedureStmt)
+  READ_FEATURE(TypeBoundProcedureStmt::WithInterface)
+  READ_FEATURE(TypeBoundProcedureStmt::WithoutInterface)
+  READ_FEATURE(TypeDeclarationStmt)
+  READ_FEATURE(TypeGuardStmt)
+  READ_FEATURE(TypeGuardStmt::Guard)
+  READ_FEATURE(TypeParamDecl)
+  READ_FEATURE(TypeParamDefStmt)
+  READ_FEATURE(common::TypeParamAttr)
+  READ_FEATURE(TypeParamSpec)
+  READ_FEATURE(TypeParamValue)
+  READ_FEATURE(TypeParamValue::Deferred)
+  READ_FEATURE(TypeSpec)
+  READ_FEATURE(Union)
+  READ_FEATURE(Union::EndUnionStmt)
+  READ_FEATURE(Union::UnionStmt)
+  READ_FEATURE(UnlockStmt)
+  READ_FEATURE(UseStmt)
+  READ_FEATURE(UseStmt::ModuleNature)
+  READ_FEATURE(Value)
+  READ_FEATURE(ValueStmt)
+  READ_FEATURE(Variable)
+  READ_FEATURE(Verbatim)
+  READ_FEATURE(Volatile)
+  READ_FEATURE(VolatileStmt)
+  READ_FEATURE(WaitSpec)
+  READ_FEATURE(WaitStmt)
+  READ_FEATURE(WhereBodyConstruct)
+  READ_FEATURE(WhereConstruct)
+  READ_FEATURE(WhereConstruct::Elsewhere)
+  READ_FEATURE(WhereConstruct::MaskedElsewhere)
+  READ_FEATURE(WhereConstructStmt)
+  READ_FEATURE(WhereStmt)
+  READ_FEATURE(WriteStmt)
+
+  READ_FEATURE(llvm::omp::Directive)
+  READ_FEATURE(llvm::omp::Clause)
+  READ_FEATURE(llvm::acc::Directive)
+  READ_FEATURE(llvm::acc::DefaultValue)
+
+  template <typename A> bool Pre(const A &) { return true; }
+  template <typename A> void Post(const A &) {}
+
+  template <typename T> bool Pre(const Statement<T> &) { return true; }
+  template <typename T> void Post(const Statement<T> &) {}
+
+  template <typename T> bool Pre(const UnlabeledStatement<T> &) { return true; }
+  template <typename T> void Post(const UnlabeledStatement<T> &) {}
+
+  template <typename T> bool Pre(const common::Indirection<T> &) {
+    return true;
+  }
+  template <typename T> void Post(const common::Indirection<T> &) {}
+
+  template <typename A> bool Pre(const Scalar<A> &) { return true; }
+  template <typename A> void Post(const Scalar<A> &) {}
+
+  template <typename A> bool Pre(const Constant<A> &) { return true; }
+  template <typename A> void Post(const Constant<A> &) {}
+
+  template <typename A> bool Pre(const Integer<A> &) { return true; }
+  template <typename A> void Post(const Integer<A> &) {}
+
+  template <typename A> bool Pre(const Logical<A> &) { return true; }
+  template <typename A> void Post(const Logical<A> &) {}
+
+  template <typename A> bool Pre(const DefaultChar<A> &) { return true; }
+  template <typename A> void Post(const DefaultChar<A> &) {}
+
+  template <typename... A> bool Pre(const std::tuple<A...> &) { return true; }
+  template <typename... A> void Post(const std::tuple<A...> &) {}
+
+  template <typename... A> bool Pre(const std::variant<A...> &) { return true; }
+  template <typename... A> void Post(const std::variant<A...> &) {}
+};
+
+class FeatureListAction : public PluginParseTreeAction {
+  void executeAction() override {
+    NodeVisitor visitor;
+    Fortran::parser::Walk(getParsing().parseTree(), visitor);
+
+    for (auto const &[feature, frequency] : visitor.getFrequencies()) {
+      llvm::outs() << feature << ": " << frequency << "\n";
+    }
+  }
+
+  bool beginSourceFileAction() override { return runPrescan() && runParse(); }
+};
+
+static FrontendPluginRegistry::Add<FeatureListAction> X(
+    "feature-list", "List program features");
diff --git a/flang/test/Examples/feature-list-class.f90 b/flang/test/Examples/feature-list-class.f90
new file mode 100644
index 000000000000..a6eca2fe3fb2
--- /dev/null
+++ b/flang/test/Examples/feature-list-class.f90
@@ -0,0 +1,88 @@
+! UNSUPPORTED: system-windows
+! REQUIRES: plugins, shell, examples
+
+! RUN: %flang_fc1 -load %llvmshlibdir/flangFeatureList.so \
+! RUN:            -plugin feature-list %s 2>&1 | FileCheck %s
+
+module list_features_test
+    implicit none
+
+    type :: test_class_1
+        integer :: a
+        real :: b
+    contains
+        procedure :: sum => sum_test_class_1
+        procedure :: set => set_values_test_class_1
+    end type
+contains
+    real function sum_test_class_1(self)
+        class(test_class_1), intent(in) :: self
+        sum_test_class_1 = self%a + self%b
+    end function
+
+    subroutine set_values_test_class_1(self, a, b)
+        class(test_class_1), intent(out) :: self
+        integer, intent(in) :: a, b
+        self%a = a
+        self%b = b
+    end subroutine
+end module list_features_test
+
+! CHECK: Name: 32
+! CHECK-NEXT: DerivedTypeSpec: 2
+! CHECK-NEXT: Expr::Add: 1
+! CHECK-NEXT: IntrinsicTypeSpec: 4
+! CHECK-NEXT: IntegerTypeSpec: 2
+! CHECK-NEXT: IntrinsicTypeSpec::Real: 2
+! CHECK-NEXT: DataRef: 11
+! CHECK-NEXT: StructureComponent: 4
+! CHECK-NEXT: Designator: 7
+! CHECK-NEXT: Expr: 5
+! CHECK-NEXT: Variable: 3
+! CHECK-NEXT: AttrSpec: 3
+! CHECK-NEXT: IntentSpec: 3
+! CHECK-NEXT: IntentSpec::Intent: 3
+! CHECK-NEXT: DummyArg: 3
+! CHECK-NEXT: DeclarationTypeSpec: 6
+! CHECK-NEXT: DeclarationTypeSpec::Class: 2
+! CHECK-NEXT: ImplicitStmt: 1
+! CHECK-NEXT: ImplicitPart: 3
+! CHECK-NEXT: ImplicitPartStmt: 1
+! CHECK-NEXT: PrefixSpec: 1
+! CHECK-NEXT: Module: 1
+! CHECK-NEXT: AssignmentStmt: 3
+! CHECK-NEXT: ActionStmt: 3
+! CHECK-NEXT: Block: 2
+! CHECK-NEXT: TypeBoundProcBinding: 2
+! CHECK-NEXT: TypeBoundProcedureStmt: 2
+! CHECK-NEXT: TypeBoundProcDecl: 2
+! CHECK-NEXT: TypeBoundProcedureStmt::WithoutInterface: 2
+! CHECK-NEXT: ComponentOrFill: 2
+! CHECK-NEXT: ComponentDecl: 2
+! CHECK-NEXT: DataComponentDefStmt: 2
+! CHECK-NEXT: ComponentDefStmt: 2
+! CHECK-NEXT: TypeBoundProcedurePart: 1
+! CHECK-NEXT: ContainsStmt: 2
+! CHECK-NEXT: EndTypeStmt: 1
+! CHECK-NEXT: DerivedTypeDef: 1
+! CHECK-NEXT: DerivedTypeStmt: 1
+! CHECK-NEXT: EntityDecl: 4
+! CHECK-NEXT: SpecificationConstruct: 4
+! CHECK-NEXT: TypeDeclarationStmt: 3
+! CHECK-NEXT: DeclarationConstruct: 4
+! CHECK-NEXT: EndFunctionStmt: 1
+! CHECK-NEXT: FunctionStmt: 1
+! CHECK-NEXT: EndSubroutineStmt: 1
+! CHECK-NEXT: SubroutineStmt: 1
+! CHECK-NEXT: ExecutionPartConstruct: 3
+! CHECK-NEXT: ExecutableConstruct: 3
+! CHECK-NEXT: SpecificationPart: 3
+! CHECK-NEXT: FunctionSubprogram: 1
+! CHECK-NEXT: ExecutionPart: 2
+! CHECK-NEXT: SubroutineSubprogram: 1
+! CHECK-NEXT: ModuleSubprogram: 2
+! CHECK-NEXT: ProgramUnit: 1
+! CHECK-NEXT: Program: 1
+! CHECK-NEXT: ModuleSubprogramPart: 1
+! CHECK-NEXT: EndModuleStmt: 1
+! CHECK-NEXT: ModuleStmt: 1
diff --git a/flang/test/Examples/feature-list-functions.f90 b/flang/test/Examples/feature-list-functions.f90
new file mode 100644
index 000000000000..6c8604980c02
--- /dev/null
+++ b/flang/test/Examples/feature-list-functions.f90
@@ -0,0 +1,76 @@
+! UNSUPPORTED: system-windows
+! REQUIRES: plugins, shell, examples
+
+! RUN: %flang_fc1 -load %llvmshlibdir/flangFeatureList.so \
+! RUN:            -plugin feature-list %s 2>&1 | FileCheck %s
+
+program list_features_test
+    implicit none
+    call test_sub(test_func(2, 3), 4)
+contains
+    subroutine test_sub(a, b)
+        integer, intent(in) :: a, b
+        print "(I0)", a + b
+    end subroutine
+
+    integer function test_func(a, b)
+        integer, intent(in) :: a, b
+        test_func = a * b
+    end function
+end program list_features_test
+
+! CHECK: Name: 19
+! CHECK-NEXT: IntLiteralConstant: 3
+! CHECK-NEXT: LiteralConstant: 4
+! CHECK-NEXT: CharLiteralConstant: 1
+! CHECK-NEXT: FunctionReference: 1
+! CHECK-NEXT: Call: 2
+! CHECK-NEXT: Expr::Multiply: 1
+! CHECK-NEXT: Expr::Add: 1
+! CHECK-NEXT: IntrinsicTypeSpec: 3
+! CHECK-NEXT: IntegerTypeSpec: 3
+! CHECK-NEXT: Format: 1
+! CHECK-NEXT: DataRef: 5
+! CHECK-NEXT: ProcedureDesignator: 2
+! CHECK-NEXT: Designator: 5
+! CHECK-NEXT: ActualArgSpec: 4
+! CHECK-NEXT: ActualArg: 4
+! CHECK-NEXT: Expr: 11
+! CHECK-NEXT: Variable: 1
+! CHECK-NEXT: AttrSpec: 2
+! CHECK-NEXT: IntentSpec: 2
+! CHECK-NEXT: IntentSpec::Intent: 2
+! CHECK-NEXT: DummyArg: 2
+! CHECK-NEXT: DeclarationTypeSpec: 3
+! CHECK-NEXT: ImplicitStmt: 1
+! CHECK-NEXT: ImplicitPart: 3
+! CHECK-NEXT: ImplicitPartStmt: 1
+! CHECK-NEXT: PrefixSpec: 1
+! CHECK-NEXT: OutputItem: 1
+! CHECK-NEXT: AssignmentStmt: 1
+! CHECK-NEXT: ActionStmt: 3
+! CHECK-NEXT: PrintStmt: 1
+! CHECK-NEXT: CallStmt: 1
+! CHECK-NEXT: Block: 3
+! CHECK-NEXT: ContainsStmt: 1
+! CHECK-NEXT: EntityDecl: 4
+! CHECK-NEXT: SpecificationConstruct: 2
+! CHECK-NEXT: TypeDeclarationStmt: 2
+! CHECK-NEXT: DeclarationConstruct: 2
+! CHECK-NEXT: EndFunctionStmt: 1
+! CHECK-NEXT: FunctionStmt: 1
+! CHECK-NEXT: EndSubroutineStmt: 1
+! CHECK-NEXT: SubroutineStmt: 1
+! CHECK-NEXT: ExecutionPartConstruct: 3
+! CHECK-NEXT: ExecutableConstruct: 3
+! CHECK-NEXT: SpecificationPart: 3
+! CHECK-NEXT: FunctionSubprogram: 1
+! CHECK-NEXT: ExecutionPart: 3
+! CHECK-NEXT: InternalSubprogramPart: 1
+! CHECK-NEXT: InternalSubprogram: 2
+! CHECK-NEXT: SubroutineSubprogram: 1
+! CHECK-NEXT: ProgramUnit: 1
+! CHECK-NEXT: MainProgram: 1
+! CHECK-NEXT: Program: 1
+! CHECK-NEXT: EndProgramStmt: 1
+! CHECK-NEXT: ProgramStmt: 1