[NFC][TableGen] Change Record::getSuperClasses to use const Record* (llvm#110845)

Change `Record::getSuperClasses` to return a const pointer to the
superclass records.

This 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/ClangAttrEmitter.cpp

@@ -1529,9 +1529,8 @@ createArgument(const Record &Arg, StringRef Attr,
 
   if (!Ptr) {
     // Search in reverse order so that the most-derived type is handled first.
-    ArrayRef<std::pair<Record*, SMRange>> Bases = Search->getSuperClasses();
-    for (const auto &Base : reverse(Bases)) {
-      if ((Ptr = createArgument(Arg, Attr, Base.first)))
+    for (const auto &[Base, _] : reverse(Search->getSuperClasses())) {
+      if ((Ptr = createArgument(Arg, Attr, Base)))
         break;
     }
   }
@@ -2744,12 +2743,11 @@ static void emitAttributes(const RecordKeeper &Records, raw_ostream &OS,
     if (!R.getValueAsBit("ASTNode"))
       continue;
 
-    ArrayRef<std::pair<Record *, SMRange>> Supers = R.getSuperClasses();
+    ArrayRef<std::pair<const Record *, SMRange>> Supers = R.getSuperClasses();
     assert(!Supers.empty() && "Forgot to specify a superclass for the attr");
     std::string SuperName;
     bool Inheritable = false;
-    for (const auto &Super : reverse(Supers)) {
-      const Record *R = Super.first;
+    for (const auto &[R, _] : reverse(Supers)) {
       if (R->getName() != "TargetSpecificAttr" &&
           R->getName() != "DeclOrTypeAttr" && SuperName.empty())
         SuperName = std::string(R->getName());
@@ -3434,7 +3432,7 @@ namespace {
     }
 
   private:
-    AttrClass *findClassByRecord(Record *R) const {
+    AttrClass *findClassByRecord(const Record *R) const {
       for (auto &Class : Classes) {
         if (Class->TheRecord == R)
           return Class.get();
@@ -4739,8 +4737,8 @@ void EmitClangAttrParsedAttrImpl(const RecordKeeper &Records, raw_ostream &OS) {
       if (Arg->getValueAsBitOrUnset("Fake", UnusedUnset))
         continue;
       ArgNames.push_back(Arg->getValueAsString("Name").str());
-      for (const auto &Class : Arg->getSuperClasses()) {
-        if (Class.first->getName().starts_with("Variadic")) {
+      for (const auto &[Class, _] : Arg->getSuperClasses()) {
+        if (Class->getName().starts_with("Variadic")) {
           ArgNames.back().append("...");
           break;
         }

llvm/docs/TableGen/BackGuide.rst

@@ -624,7 +624,7 @@ iterates over the pairs in the returned array.
 
 .. code-block:: text
 
-  ArrayRef<std::pair<Record *, SMRange>>
+  ArrayRef<std::pair<const Record *, SMRange>>
       Superclasses = Prototype->getSuperClasses();
   for (const auto &SuperPair : Superclasses) {
     ...

llvm/include/llvm/TableGen/Record.h

@@ -1668,7 +1668,7 @@ class Record {
 
   // All superclasses in the inheritance forest in post-order (yes, it
   // must be a forest; diamond-shaped inheritance is not allowed).
-  SmallVector<std::pair<Record *, SMRange>, 0> SuperClasses;
+  SmallVector<std::pair<const Record *, SMRange>, 0> SuperClasses;
 
   // Tracks Record instances. Not owned by Record.
   RecordKeeper &TrackedRecords;
@@ -1758,7 +1758,7 @@ class Record {
   ArrayRef<AssertionInfo> getAssertions() const { return Assertions; }
   ArrayRef<DumpInfo> getDumps() const { return Dumps; }
 
-  ArrayRef<std::pair<Record *, SMRange>> getSuperClasses() const {
+  ArrayRef<std::pair<const Record *, SMRange>> getSuperClasses() const {
     return SuperClasses;
   }
 
@@ -1832,25 +1832,25 @@ class Record {
   void checkUnusedTemplateArgs();
 
   bool isSubClassOf(const Record *R) const {
-    for (const auto &SCPair : SuperClasses)
-      if (SCPair.first == R)
+    for (const auto &[SC, _] : SuperClasses)
+      if (SC == R)
         return true;
     return false;
   }
 
   bool isSubClassOf(StringRef Name) const {
-    for (const auto &SCPair : SuperClasses) {
-      if (const auto *SI = dyn_cast<StringInit>(SCPair.first->getNameInit())) {
+    for (const auto &[SC, _] : SuperClasses) {
+      if (const auto *SI = dyn_cast<StringInit>(SC->getNameInit())) {
         if (SI->getValue() == Name)
           return true;
-      } else if (SCPair.first->getNameInitAsString() == Name) {
+      } else if (SC->getNameInitAsString() == Name) {
         return true;
       }
     }
     return false;
   }
 
-  void addSuperClass(Record *R, SMRange Range) {
+  void addSuperClass(const Record *R, SMRange Range) {
     assert(!CorrespondingDefInit &&
            "changing type of record after it has been referenced");
     assert(!isSubClassOf(R) && "Already subclassing record!");

llvm/lib/TableGen/DetailedRecordsBackend.cpp

@@ -152,7 +152,8 @@ void DetailedRecordsEmitter::printTemplateArgs(const Record &Rec,
 // are enclosed in parentheses.
 void DetailedRecordsEmitter::printSuperclasses(const Record &Rec,
                                                raw_ostream &OS) {
-  ArrayRef<std::pair<Record *, SMRange>> Superclasses = Rec.getSuperClasses();
+  ArrayRef<std::pair<const Record *, SMRange>> Superclasses =
+      Rec.getSuperClasses();
   if (Superclasses.empty()) {
     OS << "  Superclasses: (none)\n";
     return;

llvm/lib/TableGen/Record.cpp

@@ -2357,9 +2357,8 @@ DefInit *VarDefInit::instantiate() {
   NewRec->resolveReferences(R);
 
   // Add superclasses.
-  ArrayRef<std::pair<Record *, SMRange>> SCs = Class->getSuperClasses();
-  for (const auto &SCPair : SCs)
-    NewRec->addSuperClass(SCPair.first, SCPair.second);
+  for (const auto &[SC, Loc] : Class->getSuperClasses())
+    NewRec->addSuperClass(SC, Loc);
 
   NewRec->addSuperClass(
       Class, SMRange(Class->getLoc().back(), Class->getLoc().back()));
@@ -2869,7 +2868,7 @@ void Record::setName(Init *NewName) {
 // so we can step through the direct superclasses in reverse order.
 
 bool Record::hasDirectSuperClass(const Record *Superclass) const {
-  ArrayRef<std::pair<Record *, SMRange>> SCs = getSuperClasses();
+  ArrayRef<std::pair<const Record *, SMRange>> SCs = getSuperClasses();
 
   for (int I = SCs.size() - 1; I >= 0; --I) {
     const Record *SC = SCs[I].first;
@@ -2883,10 +2882,10 @@ bool Record::hasDirectSuperClass(const Record *Superclass) const {
 
 void Record::getDirectSuperClasses(
     SmallVectorImpl<const Record *> &Classes) const {
-  ArrayRef<std::pair<Record *, SMRange>> SCs = getSuperClasses();
+  ArrayRef<std::pair<const Record *, SMRange>> SCs = getSuperClasses();
 
   while (!SCs.empty()) {
-    Record *SC = SCs.back().first;
+    const Record *SC = SCs.back().first;
     SCs = SCs.drop_back(1 + SC->getSuperClasses().size());
     Classes.push_back(SC);
   }
@@ -2965,11 +2964,11 @@ raw_ostream &llvm::operator<<(raw_ostream &OS, const Record &R) {
   }
 
   OS << " {";
-  ArrayRef<std::pair<Record *, SMRange>> SC = R.getSuperClasses();
+  ArrayRef<std::pair<const Record *, SMRange>> SC = R.getSuperClasses();
   if (!SC.empty()) {
     OS << "\t//";
-    for (const auto &SuperPair : SC)
-      OS << " " << SuperPair.first->getNameInitAsString();
+    for (const auto &[SC, _] : SC)
+      OS << " " << SC->getNameInitAsString();
   }
   OS << "\n";
 

llvm/lib/TableGen/TGParser.cpp

@@ -328,12 +328,11 @@ bool TGParser::AddSubClass(Record *CurRec, SubClassReference &SubClass) {
 
   // Since everything went well, we can now set the "superclass" list for the
   // current record.
-  ArrayRef<std::pair<Record *, SMRange>> SCs = SC->getSuperClasses();
-  for (const auto &SCPair : SCs) {
-    if (CurRec->isSubClassOf(SCPair.first))
+  for (const auto &[SC, Loc] : SC->getSuperClasses()) {
+    if (CurRec->isSubClassOf(SC))
       return Error(SubClass.RefRange.Start,
-                   "Already subclass of '" + SCPair.first->getName() + "'!\n");
-    CurRec->addSuperClass(SCPair.first, SCPair.second);
+                   "Already subclass of '" + SC->getName() + "'!\n");
+    CurRec->addSuperClass(SC, Loc);
   }
 
   if (CurRec->isSubClassOf(SC))

llvm/utils/TableGen/CallingConvEmitter.cpp

@@ -110,7 +110,7 @@ void CallingConvEmitter::EmitCallingConv(const Record *CC, raw_ostream &O) {
     const Record *Action = CCActions->getElementAsRecord(i);
     SwiftAction =
         llvm::any_of(Action->getSuperClasses(),
-                     [](const std::pair<Record *, SMRange> &Class) {
+                     [](const std::pair<const Record *, SMRange> &Class) {
                        std::string Name = Class.first->getNameInitAsString();
                        return StringRef(Name).starts_with("CCIfSwift");
                      });

llvm/utils/TableGen/Common/CodeGenRegisters.cpp

@@ -697,9 +697,8 @@ struct TupleExpander : SetTheory::Expander {
                         "Register tuple redefines register '" + Name + "'.");
 
       // Copy Proto super-classes.
-      ArrayRef<std::pair<Record *, SMRange>> Supers = Proto->getSuperClasses();
-      for (const auto &SuperPair : Supers)
-        NewReg->addSuperClass(SuperPair.first, SuperPair.second);
+      for (const auto &[Super, Loc] : Proto->getSuperClasses())
+        NewReg->addSuperClass(Super, Loc);
 
       // Copy Proto fields.
       for (unsigned i = 0, e = Proto->getValues().size(); i != e; ++i) {

mlir/lib/Tools/tblgen-lsp-server/TableGenServer.cpp

@@ -112,7 +112,7 @@ getBaseValue(const Record *record, const RecordVal *value) {
   // Find a base value for the field in the super classes of the given record.
   // On success, `record` is updated to the new parent record.
   StringRef valueName = value->getName();
-  auto findValueInSupers = [&](const Record *&record) -> RecordVal * {
+  auto findValueInSupers = [&](const Record *&record) -> const RecordVal * {
     for (auto [parentRecord, loc] : record->getSuperClasses()) {
       if (auto *newBase = parentRecord->getValue(valueName)) {
         record = parentRecord;