[TableGen] Change DefInit::Def to a const Record pointer (llvm#110747)

This change undoes a const_cast<> introduced in an earlier change to
help transition to const pointers. It is a part of effort to have better
const correctness in TableGen backends:


https://discourse.llvm.org/t/psa-planned-changes-to-tablegen-getallderiveddefinitions-api-potential-downstream-breakages/81089

Author: jurahul

clang/utils/TableGen/ClangOptionDocEmitter.cpp

@@ -181,7 +181,7 @@ const unsigned UnlimitedArgs = unsigned(-1);
 
 // Get the number of arguments expected for an option, or -1 if any number of
 // arguments are accepted.
-unsigned getNumArgsForKind(Record *OptionKind, const Record *Option) {
+unsigned getNumArgsForKind(const Record *OptionKind, const Record *Option) {
   return StringSwitch<unsigned>(OptionKind->getName())
     .Cases("KIND_JOINED", "KIND_JOINED_OR_SEPARATE", "KIND_SEPARATE", 1)
     .Cases("KIND_REMAINING_ARGS", "KIND_REMAINING_ARGS_JOINED",

llvm/include/llvm/TableGen/DirectiveEmitter.h

@@ -155,9 +155,11 @@ class Directive : public BaseRecord {
     return Def->getValueAsListOfDefs("leafConstructs");
   }
 
-  Record *getAssociation() const { return Def->getValueAsDef("association"); }
+  const Record *getAssociation() const {
+    return Def->getValueAsDef("association");
+  }
 
-  Record *getCategory() const { return Def->getValueAsDef("category"); }
+  const Record *getCategory() const { return Def->getValueAsDef("category"); }
 };
 
 // Wrapper class that contains Clause's information defined in DirectiveBase.td

llvm/include/llvm/TableGen/Record.h

@@ -783,7 +783,7 @@ class ListInit final : public TypedInit, public FoldingSetNode,
     return cast<ListRecTy>(getType())->getElementType();
   }
 
-  Record *getElementAsRecord(unsigned i) const;
+  const Record *getElementAsRecord(unsigned i) const;
 
   Init *convertInitializerTo(const RecTy *Ty) const override;
 
@@ -1316,9 +1316,9 @@ class VarBitInit final : public TypedInit {
 class DefInit : public TypedInit {
   friend class Record;
 
-  Record *Def;
+  const Record *Def;
 
-  explicit DefInit(Record *D);
+  explicit DefInit(const Record *D);
 
 public:
   DefInit(const DefInit &) = delete;
@@ -1330,7 +1330,7 @@ class DefInit : public TypedInit {
 
   Init *convertInitializerTo(const RecTy *Ty) const override;
 
-  Record *getDef() const { return Def; }
+  const Record *getDef() const { return Def; }
 
   const RecTy *getFieldType(StringInit *FieldName) const override;
 
@@ -1473,7 +1473,7 @@ class DagInit final : public TypedInit, public FoldingSetNode,
   void Profile(FoldingSetNodeID &ID) const;
 
   Init *getOperator() const { return Val; }
-  Record *getOperatorAsDef(ArrayRef<SMLoc> Loc) const;
+  const Record *getOperatorAsDef(ArrayRef<SMLoc> Loc) const;
 
   StringInit *getName() const { return ValName; }
 
@@ -1660,7 +1660,7 @@ class Record {
   // this record.
   SmallVector<SMLoc, 4> Locs;
   SmallVector<SMLoc, 0> ForwardDeclarationLocs;
-  SmallVector<SMRange, 0> ReferenceLocs;
+  mutable SmallVector<SMRange, 0> ReferenceLocs;
   SmallVector<Init *, 0> TemplateArgs;
   SmallVector<RecordVal, 0> Values;
   SmallVector<AssertionInfo, 0> Assertions;
@@ -1729,7 +1729,7 @@ class Record {
   }
 
   /// Add a reference to this record value.
-  void appendReferenceLoc(SMRange Loc) { ReferenceLocs.push_back(Loc); }
+  void appendReferenceLoc(SMRange Loc) const { ReferenceLocs.push_back(Loc); }
 
   /// Return the references of this record value.
   ArrayRef<SMRange> getReferenceLocs() const { return ReferenceLocs; }
@@ -1931,13 +1931,13 @@ class Record {
   /// This method looks up the specified field and returns its value as a
   /// Record, throwing an exception if the field does not exist or if the value
   /// is not the right type.
-  Record *getValueAsDef(StringRef FieldName) const;
+  const Record *getValueAsDef(StringRef FieldName) const;
 
   /// This method looks up the specified field and returns its value as a
   /// Record, returning null if the field exists but is "uninitialized" (i.e.
   /// set to `?`), and throwing an exception if the field does not exist or if
   /// its value is not the right type.
-  Record *getValueAsOptionalDef(StringRef FieldName) const;
+  const Record *getValueAsOptionalDef(StringRef FieldName) const;
 
   /// This method looks up the specified field and returns its value as a bit,
   /// throwing an exception if the field does not exist or if the value is not

llvm/lib/TableGen/Record.cpp

@@ -746,7 +746,7 @@ Init *ListInit::convertInitializerTo(const RecTy *Ty) const {
   return nullptr;
 }
 
-Record *ListInit::getElementAsRecord(unsigned i) const {
+const Record *ListInit::getElementAsRecord(unsigned i) const {
   assert(i < NumValues && "List element index out of range!");
   DefInit *DI = dyn_cast<DefInit>(getElement(i));
   if (!DI)
@@ -1713,7 +1713,7 @@ Init *TernOpInit::Fold(Record *CurRec) const {
     StringInit *RHSs = dyn_cast<StringInit>(RHS);
 
     if (LHSd && MHSd && RHSd) {
-      Record *Val = RHSd->getDef();
+      const Record *Val = RHSd->getDef();
       if (LHSd->getAsString() == RHSd->getAsString())
         Val = MHSd->getDef();
       return Val->getDefInit();
@@ -2265,7 +2265,7 @@ Init *VarBitInit::resolveReferences(Resolver &R) const {
   return const_cast<VarBitInit*>(this);
 }
 
-DefInit::DefInit(Record *D)
+DefInit::DefInit(const Record *D)
     : TypedInit(IK_DefInit, D->getType()), Def(D) {}
 
 Init *DefInit::convertInitializerTo(const RecTy *Ty) const {
@@ -2445,7 +2445,7 @@ Init *FieldInit::resolveReferences(Resolver &R) const {
 
 Init *FieldInit::Fold(Record *CurRec) const {
   if (DefInit *DI = dyn_cast<DefInit>(Rec)) {
-    Record *Def = DI->getDef();
+    const Record *Def = DI->getDef();
     if (Def == CurRec)
       PrintFatalError(CurRec->getLoc(),
                       Twine("Attempting to access field '") +
@@ -2656,7 +2656,7 @@ void DagInit::Profile(FoldingSetNodeID &ID) const {
                  ArrayRef(getTrailingObjects<StringInit *>(), NumArgNames));
 }
 
-Record *DagInit::getOperatorAsDef(ArrayRef<SMLoc> Loc) const {
+const Record *DagInit::getOperatorAsDef(ArrayRef<SMLoc> Loc) const {
   if (DefInit *DefI = dyn_cast<DefInit>(Val))
     return DefI->getDef();
   PrintFatalError(Loc, "Expected record as operator");
@@ -2837,8 +2837,8 @@ const RecordRecTy *Record::getType() const {
 
 DefInit *Record::getDefInit() const {
   if (!CorrespondingDefInit) {
-    CorrespondingDefInit = new (TrackedRecords.getImpl().Allocator)
-        DefInit(const_cast<Record *>(this));
+    CorrespondingDefInit =
+        new (TrackedRecords.getImpl().Allocator) DefInit(this);
   }
   return CorrespondingDefInit;
 }
@@ -3108,7 +3108,7 @@ Record::getValueAsListOfStrings(StringRef FieldName) const {
   return Strings;
 }
 
-Record *Record::getValueAsDef(StringRef FieldName) const {
+const Record *Record::getValueAsDef(StringRef FieldName) const {
   const RecordVal *R = getValue(FieldName);
   if (!R || !R->getValue())
     PrintFatalError(getLoc(), "Record `" + getName() +
@@ -3120,7 +3120,7 @@ Record *Record::getValueAsDef(StringRef FieldName) const {
     FieldName + "' does not have a def initializer!");
 }
 
-Record *Record::getValueAsOptionalDef(StringRef FieldName) const {
+const Record *Record::getValueAsOptionalDef(StringRef FieldName) const {
   const RecordVal *R = getValue(FieldName);
   if (!R || !R->getValue())
     PrintFatalError(getLoc(), "Record `" + getName() +
@@ -3134,7 +3134,6 @@ Record *Record::getValueAsOptionalDef(StringRef FieldName) const {
     FieldName + "' does not have either a def initializer or '?'!");
 }
 
-
 bool Record::getValueAsBit(StringRef FieldName) const {
   const RecordVal *R = getValue(FieldName);
   if (!R || !R->getValue())

llvm/lib/TableGen/TGParser.cpp

@@ -3001,7 +3001,8 @@ Init *TGParser::ParseValue(Record *CurRec, const RecTy *ItemType,
       // Add a reference to this field if we know the record class.
       if (TrackReferenceLocs) {
         if (auto *DI = dyn_cast<DefInit>(Result)) {
-          DI->getDef()->getValue(FieldName)->addReferenceLoc(FieldNameLoc);
+          const RecordVal *V = DI->getDef()->getValue(FieldName);
+          const_cast<RecordVal *>(V)->addReferenceLoc(FieldNameLoc);
         } else if (auto *TI = dyn_cast<TypedInit>(Result)) {
           if (auto *RecTy = dyn_cast<RecordRecTy>(TI->getType())) {
             for (const Record *R : RecTy->getClasses())

llvm/utils/TableGen/Common/CodeGenDAGPatterns.cpp

@@ -3698,7 +3698,7 @@ static bool hasNullFragReference(DagInit *DI) {
   DefInit *OpDef = dyn_cast<DefInit>(DI->getOperator());
   if (!OpDef)
     return false;
-  Record *Operator = OpDef->getDef();
+  const Record *Operator = OpDef->getDef();
 
   // If this is the null fragment, return true.
   if (Operator->getName() == "null_frag")

llvm/utils/TableGen/Common/CodeGenSchedule.cpp

@@ -552,7 +552,7 @@ void CodeGenSchedModels::addProcModel(const Record *ProcDef) {
 
   std::string Name = std::string(ModelKey->getName());
   if (ModelKey->isSubClassOf("SchedMachineModel")) {
-    Record *ItinsDef = ModelKey->getValueAsDef("Itineraries");
+    const Record *ItinsDef = ModelKey->getValueAsDef("Itineraries");
     ProcModels.emplace_back(ProcModels.size(), Name, ModelKey, ItinsDef);
   } else {
     // An itinerary is defined without a machine model. Infer a new model.
@@ -674,9 +674,9 @@ void CodeGenSchedModels::collectSchedRW() {
   }
   // Initialize Aliases vectors.
   for (const Record *ADef : AliasDefs) {
-    Record *AliasDef = ADef->getValueAsDef("AliasRW");
+    const Record *AliasDef = ADef->getValueAsDef("AliasRW");
     getSchedRW(AliasDef).IsAlias = true;
-    Record *MatchDef = ADef->getValueAsDef("MatchRW");
+    const Record *MatchDef = ADef->getValueAsDef("MatchRW");
     CodeGenSchedRW &RW = getSchedRW(MatchDef);
     if (RW.IsAlias)
       PrintFatalError(ADef->getLoc(), "Cannot Alias an Alias");
@@ -781,7 +781,7 @@ void CodeGenSchedModels::expandRWSeqForProc(
   for (const Record *Rec : SchedWrite.Aliases) {
     const CodeGenSchedRW &AliasRW = getSchedRW(Rec->getValueAsDef("AliasRW"));
     if (Rec->getValueInit("SchedModel")->isComplete()) {
-      Record *ModelDef = Rec->getValueAsDef("SchedModel");
+      const Record *ModelDef = Rec->getValueAsDef("SchedModel");
       if (&getProcModel(ModelDef) != &ProcModel)
         continue;
     }
@@ -854,7 +854,7 @@ void CodeGenSchedModels::collectSchedClasses() {
   // Create a SchedClass for each unique combination of itinerary class and
   // SchedRW list.
   for (const CodeGenInstruction *Inst : Target.getInstructionsByEnumValue()) {
-    Record *ItinDef = Inst->TheDef->getValueAsDef("Itinerary");
+    const Record *ItinDef = Inst->TheDef->getValueAsDef("Itinerary");
     IdxVec Writes, Reads;
     if (!Inst->TheDef->isValueUnset("SchedRW"))
       findRWs(Inst->TheDef->getValueAsListOfDefs("SchedRW"), Writes, Reads);
@@ -1050,7 +1050,7 @@ void CodeGenSchedModels::createInstRWClass(const Record *InstRWDef) {
         if (OrigNumInstrs == InstDefs.size()) {
           assert(SchedClasses[OldSCIdx].ProcIndices[0] == 0 &&
                  "expected a generic SchedClass");
-          Record *RWModelDef = InstRWDef->getValueAsDef("SchedModel");
+          const Record *RWModelDef = InstRWDef->getValueAsDef("SchedModel");
           // Make sure we didn't already have a InstRW containing this
           // instruction on this model.
           for (const Record *RWD : RWDefs) {
@@ -1279,7 +1279,7 @@ struct PredCheck {
   unsigned RWIdx;
   const Record *Predicate;
 
-  PredCheck(bool r, unsigned w, Record *p)
+  PredCheck(bool r, unsigned w, const Record *p)
       : IsRead(r), RWIdx(w), Predicate(p) {}
 };
 
@@ -1318,7 +1318,7 @@ class PredTransitions {
 #endif
 
 private:
-  bool mutuallyExclusive(Record *PredDef, ArrayRef<Record *> Preds,
+  bool mutuallyExclusive(const Record *PredDef, ArrayRef<const Record *> Preds,
                          ArrayRef<PredCheck> Term);
   void getIntersectingVariants(const CodeGenSchedRW &SchedRW, unsigned TransIdx,
                                std::vector<TransVariant> &IntersectingVariants);
@@ -1336,8 +1336,8 @@ class PredTransitions {
 // predicates are not exclusive because the predicates for a given SchedWrite
 // are always checked in the order they are defined in the .td file. Later
 // conditions implicitly negate any prior condition.
-bool PredTransitions::mutuallyExclusive(Record *PredDef,
-                                        ArrayRef<Record *> Preds,
+bool PredTransitions::mutuallyExclusive(const Record *PredDef,
+                                        ArrayRef<const Record *> Preds,
                                         ArrayRef<PredCheck> Term) {
   for (const PredCheck &PC : Term) {
     if (PC.Predicate == PredDef)
@@ -1382,9 +1382,9 @@ bool PredTransitions::mutuallyExclusive(Record *PredDef,
   return false;
 }
 
-static std::vector<Record *> getAllPredicates(ArrayRef<TransVariant> Variants,
-                                              unsigned ProcId) {
-  std::vector<Record *> Preds;
+static std::vector<const Record *>
+getAllPredicates(ArrayRef<TransVariant> Variants, unsigned ProcId) {
+  std::vector<const Record *> Preds;
   for (auto &Variant : Variants) {
     if (!Variant.VarOrSeqDef->isSubClassOf("SchedVar"))
       continue;
@@ -1406,7 +1406,7 @@ void PredTransitions::getIntersectingVariants(
   if (SchedRW.HasVariants) {
     unsigned VarProcIdx = 0;
     if (SchedRW.TheDef->getValueInit("SchedModel")->isComplete()) {
-      Record *ModelDef = SchedRW.TheDef->getValueAsDef("SchedModel");
+      const Record *ModelDef = SchedRW.TheDef->getValueAsDef("SchedModel");
       VarProcIdx = SchedModels.getProcModel(ModelDef).Index;
     }
     if (VarProcIdx == 0 || VarProcIdx == TransVec[TransIdx].ProcIndex) {
@@ -1425,7 +1425,7 @@ void PredTransitions::getIntersectingVariants(
     // that processor.
     unsigned AliasProcIdx = 0;
     if ((*AI)->getValueInit("SchedModel")->isComplete()) {
-      Record *ModelDef = (*AI)->getValueAsDef("SchedModel");
+      const Record *ModelDef = (*AI)->getValueAsDef("SchedModel");
       AliasProcIdx = SchedModels.getProcModel(ModelDef).Index;
     }
     if (AliasProcIdx && AliasProcIdx != TransVec[TransIdx].ProcIndex)
@@ -1451,13 +1451,13 @@ void PredTransitions::getIntersectingVariants(
     if (AliasProcIdx == 0)
       GenericRW = true;
   }
-  std::vector<Record *> AllPreds =
+  std::vector<const Record *> AllPreds =
       getAllPredicates(Variants, TransVec[TransIdx].ProcIndex);
   for (TransVariant &Variant : Variants) {
     // Don't expand variants if the processor models don't intersect.
     // A zero processor index means any processor.
     if (Variant.VarOrSeqDef->isSubClassOf("SchedVar")) {
-      Record *PredDef = Variant.VarOrSeqDef->getValueAsDef("Predicate");
+      const Record *PredDef = Variant.VarOrSeqDef->getValueAsDef("Predicate");
       if (mutuallyExclusive(PredDef, AllPreds, TransVec[TransIdx].PredTerm))
         continue;
     }
@@ -1489,7 +1489,7 @@ void PredTransitions::pushVariant(const TransVariant &VInfo, bool IsRead) {
   // then the whole transition is specific to this processor.
   IdxVec SelectedRWs;
   if (VInfo.VarOrSeqDef->isSubClassOf("SchedVar")) {
-    Record *PredDef = VInfo.VarOrSeqDef->getValueAsDef("Predicate");
+    const Record *PredDef = VInfo.VarOrSeqDef->getValueAsDef("Predicate");
     Trans.PredTerm.emplace_back(IsRead, VInfo.RWIdx, PredDef);
     ConstRecVec SelectedDefs =
         VInfo.VarOrSeqDef->getValueAsListOfDefs("Selected");
@@ -1861,7 +1861,7 @@ void CodeGenSchedModels::collectProcResources() {
     // This class may have a default ReadWrite list which can be overriden by
     // InstRW definitions.
     for (const Record *RW : SC.InstRWs) {
-      Record *RWModelDef = RW->getValueAsDef("SchedModel");
+      const Record *RWModelDef = RW->getValueAsDef("SchedModel");
       unsigned PIdx = getProcModel(RWModelDef).Index;
       IdxVec Writes, Reads;
       findRWs(RW->getValueAsListOfDefs("OperandReadWrites"), Writes, Reads);

llvm/utils/TableGen/Common/GlobalISel/CombinerUtils.h

@@ -32,7 +32,7 @@ inline bool isSpecificDef(const Init &N, StringRef Def) {
 /// subclass of the given class and coerce it to a def if it is. This is
 /// primarily useful for testing for subclasses of GIDefKind and similar in
 /// DagInit's since DagInit's support any type inside them.
-inline Record *getDefOfSubClass(const Init &N, StringRef Cls) {
+inline const Record *getDefOfSubClass(const Init &N, StringRef Cls) {
   if (const DefInit *OpI = dyn_cast<DefInit>(&N))
     if (OpI->getDef()->isSubClassOf(Cls))
       return OpI->getDef();

llvm/utils/TableGen/Common/GlobalISel/GlobalISelMatchTable.h

@@ -1998,7 +1998,7 @@ class CopyOrAddZeroRegRenderer : public OperandRenderer {
 
 public:
   CopyOrAddZeroRegRenderer(unsigned NewInsnID, StringRef SymbolicName,
-                           Record *ZeroRegisterDef)
+                           const Record *ZeroRegisterDef)
       : OperandRenderer(OR_CopyOrAddZeroReg), NewInsnID(NewInsnID),
         SymbolicName(SymbolicName), ZeroRegisterDef(ZeroRegisterDef) {
     assert(!SymbolicName.empty() && "Cannot copy from an unspecified source");

mlir/include/mlir/TableGen/Attribute.h

@@ -204,7 +204,7 @@ class EnumAttr : public Attribute {
   std::vector<EnumAttrCase> getAllCases() const;
 
   bool genSpecializedAttr() const;
-  llvm::Record *getBaseAttrClass() const;
+  const llvm::Record *getBaseAttrClass() const;
   StringRef getSpecializedAttrClassName() const;
   bool printBitEnumPrimaryGroups() const;
 };

mlir/lib/TableGen/Attribute.cpp

@@ -229,7 +229,7 @@ bool EnumAttr::genSpecializedAttr() const {
   return def->getValueAsBit("genSpecializedAttr");
 }
 
-llvm::Record *EnumAttr::getBaseAttrClass() const {
+const llvm::Record *EnumAttr::getBaseAttrClass() const {
   return def->getValueAsDef("baseAttrClass");
 }