[clang][TableGen] Change NeonEmitter to use const RecordKeeper

[jurahul]

Change NeonEmitter to use const RecordKeeper.

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

[llvmbot]

@llvm/pr-subscribers-clang

Author: Rahul Joshi (jurahul)

Changes

Change NeonEmitter to use const RecordKeeper.

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

---

Full diff: https://github.com/llvm/llvm-project/pull/108501.diff

2 Files Affected:

• (modified) clang/utils/TableGen/NeonEmitter.cpp (+28-33)
• (modified) clang/utils/TableGen/TableGenBackends.h (+6-6)

diff --git a/clang/utils/TableGen/NeonEmitter.cpp b/clang/utils/TableGen/NeonEmitter.cpp
index 4707ce1ea3b792..9e5480be20adac 100644
--- a/clang/utils/TableGen/NeonEmitter.cpp
+++ b/clang/utils/TableGen/NeonEmitter.cpp
@@ -59,7 +59,7 @@ namespace {
 // While globals are generally bad, this one allows us to perform assertions
 // liberally and somehow still trace them back to the def they indirectly
 // came from.
-static Record *CurrentRecord = nullptr;
+static const Record *CurrentRecord = nullptr;
 static void assert_with_loc(bool Assertion, const std::string &Str) {
   if (!Assertion) {
     if (CurrentRecord)
@@ -308,7 +308,7 @@ class Variable {
 /// a particular typespec and prototype.
 class Intrinsic {
   /// The Record this intrinsic was created from.
-  Record *R;
+  const Record *R;
   /// The unmangled name.
   std::string Name;
   /// The input and output typespecs. InTS == OutTS except when
@@ -371,7 +371,7 @@ class Intrinsic {
   }
 
 public:
-  Intrinsic(Record *R, StringRef Name, StringRef Proto, TypeSpec OutTS,
+  Intrinsic(const Record *R, StringRef Name, StringRef Proto, TypeSpec OutTS,
             TypeSpec InTS, ClassKind CK, ListInit *Body, NeonEmitter &Emitter,
             StringRef ArchGuard, StringRef TargetGuard, bool IsUnavailable,
             bool BigEndianSafe)
@@ -442,7 +442,7 @@ class Intrinsic {
   }
 
   /// Get the Record that this intrinsic is based off.
-  Record *getRecord() const { return R; }
+  const Record *getRecord() const { return R; }
   /// Get the set of Intrinsics that this intrinsic calls.
   /// this is the set of immediate dependencies, NOT the
   /// transitive closure.
@@ -576,12 +576,12 @@ class Intrinsic {
 //===----------------------------------------------------------------------===//
 
 class NeonEmitter {
-  RecordKeeper &Records;
-  DenseMap<Record *, ClassKind> ClassMap;
+  const RecordKeeper &Records;
+  DenseMap<const Record *, ClassKind> ClassMap;
   std::map<std::string, std::deque<Intrinsic>> IntrinsicMap;
   unsigned UniqueNumber;
 
-  void createIntrinsic(Record *R, SmallVectorImpl<Intrinsic *> &Out);
+  void createIntrinsic(const Record *R, SmallVectorImpl<Intrinsic *> &Out);
   void genBuiltinsDef(raw_ostream &OS, SmallVectorImpl<Intrinsic *> &Defs);
   void genStreamingSVECompatibleList(raw_ostream &OS,
                                      SmallVectorImpl<Intrinsic *> &Defs);
@@ -601,15 +601,15 @@ class NeonEmitter {
   /// Called by Intrinsic - returns a globally-unique number.
   unsigned getUniqueNumber() { return UniqueNumber++; }
 
-  NeonEmitter(RecordKeeper &R) : Records(R), UniqueNumber(0) {
-    Record *SI = R.getClass("SInst");
-    Record *II = R.getClass("IInst");
-    Record *WI = R.getClass("WInst");
-    Record *SOpI = R.getClass("SOpInst");
-    Record *IOpI = R.getClass("IOpInst");
-    Record *WOpI = R.getClass("WOpInst");
-    Record *LOpI = R.getClass("LOpInst");
-    Record *NoTestOpI = R.getClass("NoTestOpInst");
+  NeonEmitter(const RecordKeeper &R) : Records(R), UniqueNumber(0) {
+    const Record *SI = R.getClass("SInst");
+    const Record *II = R.getClass("IInst");
+    const Record *WI = R.getClass("WInst");
+    const Record *SOpI = R.getClass("SOpInst");
+    const Record *IOpI = R.getClass("IOpInst");
+    const Record *WOpI = R.getClass("WOpInst");
+    const Record *LOpI = R.getClass("LOpInst");
+    const Record *NoTestOpI = R.getClass("NoTestOpInst");
 
     ClassMap[SI] = ClassS;
     ClassMap[II] = ClassI;
@@ -1979,12 +1979,12 @@ Intrinsic &NeonEmitter::getIntrinsic(StringRef Name, ArrayRef<Type> Types,
   return *GoodVec.front();
 }
 
-void NeonEmitter::createIntrinsic(Record *R,
+void NeonEmitter::createIntrinsic(const Record *R,
                                   SmallVectorImpl<Intrinsic *> &Out) {
   std::string Name = std::string(R->getValueAsString("Name"));
   std::string Proto = std::string(R->getValueAsString("Prototype"));
   std::string Types = std::string(R->getValueAsString("Types"));
-  Record *OperationRec = R->getValueAsDef("Operation");
+  const Record *OperationRec = R->getValueAsDef("Operation");
   bool BigEndianSafe  = R->getValueAsBit("BigEndianSafe");
   std::string ArchGuard = std::string(R->getValueAsString("ArchGuard"));
   std::string TargetGuard = std::string(R->getValueAsString("TargetGuard"));
@@ -2240,10 +2240,8 @@ void NeonEmitter::genIntrinsicRangeCheckCode(
 /// 2. the SemaChecking code for the type overload checking.
 /// 3. the SemaChecking code for validation of intrinsic immediate arguments.
 void NeonEmitter::runHeader(raw_ostream &OS) {
-  std::vector<Record *> RV = Records.getAllDerivedDefinitions("Inst");
-
   SmallVector<Intrinsic *, 128> Defs;
-  for (auto *R : RV)
+  for (const Record *R : Records.getAllDerivedDefinitions("Inst"))
     createIntrinsic(R, Defs);
 
   // Generate shared BuiltinsXXX.def
@@ -2402,8 +2400,7 @@ void NeonEmitter::run(raw_ostream &OS) {
         "__nodebug__))\n\n";
 
   SmallVector<Intrinsic *, 128> Defs;
-  std::vector<Record *> RV = Records.getAllDerivedDefinitions("Inst");
-  for (auto *R : RV)
+  for (const Record *R : Records.getAllDerivedDefinitions("Inst"))
     createIntrinsic(R, Defs);
 
   for (auto *I : Defs)
@@ -2510,8 +2507,7 @@ void NeonEmitter::runFP16(raw_ostream &OS) {
         "__nodebug__))\n\n";
 
   SmallVector<Intrinsic *, 128> Defs;
-  std::vector<Record *> RV = Records.getAllDerivedDefinitions("Inst");
-  for (auto *R : RV)
+  for (const Record *R : Records.getAllDerivedDefinitions("Inst"))
     createIntrinsic(R, Defs);
 
   for (auto *I : Defs)
@@ -2619,8 +2615,7 @@ void NeonEmitter::runBF16(raw_ostream &OS) {
         "__nodebug__))\n\n";
 
   SmallVector<Intrinsic *, 128> Defs;
-  std::vector<Record *> RV = Records.getAllDerivedDefinitions("Inst");
-  for (auto *R : RV)
+  for (const Record *R : Records.getAllDerivedDefinitions("Inst"))
     createIntrinsic(R, Defs);
 
   for (auto *I : Defs)
@@ -2674,26 +2669,26 @@ void NeonEmitter::runBF16(raw_ostream &OS) {
   OS << "#endif\n";
 }
 
-void clang::EmitNeon(RecordKeeper &Records, raw_ostream &OS) {
+void clang::EmitNeon(const RecordKeeper &Records, raw_ostream &OS) {
   NeonEmitter(Records).run(OS);
 }
 
-void clang::EmitFP16(RecordKeeper &Records, raw_ostream &OS) {
+void clang::EmitFP16(const RecordKeeper &Records, raw_ostream &OS) {
   NeonEmitter(Records).runFP16(OS);
 }
 
-void clang::EmitBF16(RecordKeeper &Records, raw_ostream &OS) {
+void clang::EmitBF16(const RecordKeeper &Records, raw_ostream &OS) {
   NeonEmitter(Records).runBF16(OS);
 }
 
-void clang::EmitNeonSema(RecordKeeper &Records, raw_ostream &OS) {
+void clang::EmitNeonSema(const RecordKeeper &Records, raw_ostream &OS) {
   NeonEmitter(Records).runHeader(OS);
 }
 
-void clang::EmitVectorTypes(RecordKeeper &Records, raw_ostream &OS) {
+void clang::EmitVectorTypes(const RecordKeeper &Records, raw_ostream &OS) {
   NeonEmitter(Records).runVectorTypes(OS);
 }
 
-void clang::EmitNeonTest(RecordKeeper &Records, raw_ostream &OS) {
+void clang::EmitNeonTest(const RecordKeeper &Records, raw_ostream &OS) {
   llvm_unreachable("Neon test generation no longer implemented!");
 }
diff --git a/clang/utils/TableGen/TableGenBackends.h b/clang/utils/TableGen/TableGenBackends.h
index 01d16d2dc3e5f1..7db1014791cdee 100644
--- a/clang/utils/TableGen/TableGenBackends.h
+++ b/clang/utils/TableGen/TableGenBackends.h
@@ -113,12 +113,12 @@ void EmitClangSyntaxNodeList(llvm::RecordKeeper &Records,
 void EmitClangSyntaxNodeClasses(llvm::RecordKeeper &Records,
                                 llvm::raw_ostream &OS);
 
-void EmitNeon(llvm::RecordKeeper &Records, llvm::raw_ostream &OS);
-void EmitFP16(llvm::RecordKeeper &Records, llvm::raw_ostream &OS);
-void EmitBF16(llvm::RecordKeeper &Records, llvm::raw_ostream &OS);
-void EmitNeonSema(llvm::RecordKeeper &Records, llvm::raw_ostream &OS);
-void EmitVectorTypes(llvm::RecordKeeper &Records, llvm::raw_ostream &OS);
-void EmitNeonTest(llvm::RecordKeeper &Records, llvm::raw_ostream &OS);
+void EmitNeon(const llvm::RecordKeeper &Records, llvm::raw_ostream &OS);
+void EmitFP16(const llvm::RecordKeeper &Records, llvm::raw_ostream &OS);
+void EmitBF16(const llvm::RecordKeeper &Records, llvm::raw_ostream &OS);
+void EmitNeonSema(const llvm::RecordKeeper &Records, llvm::raw_ostream &OS);
+void EmitVectorTypes(const llvm::RecordKeeper &Records, llvm::raw_ostream &OS);
+void EmitNeonTest(const llvm::RecordKeeper &Records, llvm::raw_ostream &OS);
 
 void EmitImmCheckTypes(llvm::RecordKeeper &Records, llvm::raw_ostream &OS);
 void EmitSveHeader(llvm::RecordKeeper &Records, llvm::raw_ostream &OS);

[AaronBallman]

LGTM!