[SandboxIR] Implement ConstantTokenNone (#108106)

This patch implements sandboxir::ConstantTokenNone mirroring
llvm::ConstantTokenNone.

Author: vporpo

llvm/include/llvm/SandboxIR/SandboxIR.h

@@ -124,6 +124,7 @@ class ConstantAggregateZero;
 class ConstantPointerNull;
 class PoisonValue;
 class BlockAddress;
+class ConstantTokenNone;
 class Context;
 class Function;
 class Instruction;
@@ -1141,6 +1142,37 @@ class BlockAddress final : public Constant {
   }
 };
 
+// TODO: This should inherit from ConstantData.
+class ConstantTokenNone final : public Constant {
+  ConstantTokenNone(llvm::ConstantTokenNone *C, Context &Ctx)
+      : Constant(ClassID::ConstantTokenNone, C, Ctx) {}
+  friend class Context; // For constructor.
+
+public:
+  /// Return the ConstantTokenNone.
+  static ConstantTokenNone *get(Context &Ctx);
+
+  /// For isa/dyn_cast.
+  static bool classof(const sandboxir::Value *From) {
+    return From->getSubclassID() == ClassID::ConstantTokenNone;
+  }
+
+  unsigned getUseOperandNo(const Use &Use) const final {
+    llvm_unreachable("ConstantTokenNone has no operands!");
+  }
+
+#ifndef NDEBUG
+  void verify() const override {
+    assert(isa<llvm::ConstantTokenNone>(Val) &&
+           "Expected a ConstantTokenNone!");
+  }
+  void dumpOS(raw_ostream &OS) const override {
+    dumpCommonPrefix(OS);
+    dumpCommonSuffix(OS);
+  }
+#endif
+};
+
 /// Iterator for `Instruction`s in a `BasicBlock.
 /// \Returns an sandboxir::Instruction & when derereferenced.
 class BBIterator {

llvm/include/llvm/SandboxIR/SandboxIRValues.def

@@ -35,6 +35,7 @@ DEF_CONST(ConstantPointerNull, ConstantPointerNull)
 DEF_CONST(UndefValue, UndefValue)
 DEF_CONST(PoisonValue, PoisonValue)
 DEF_CONST(BlockAddress, BlockAddress)
+DEF_CONST(ConstantTokenNone, ConstantTokenNone)
 
 #ifndef DEF_INSTR
 #define DEF_INSTR(ID, OPCODE, CLASS)

llvm/lib/SandboxIR/SandboxIR.cpp

@@ -2521,6 +2521,11 @@ BasicBlock *BlockAddress::getBasicBlock() const {
       Ctx.getValue(cast<llvm::BlockAddress>(Val)->getBasicBlock()));
 }
 
+ConstantTokenNone *ConstantTokenNone::get(Context &Ctx) {
+  auto *LLVMC = llvm::ConstantTokenNone::get(Ctx.LLVMCtx);
+  return cast<ConstantTokenNone>(Ctx.getOrCreateConstant(LLVMC));
+}
+
 FunctionType *Function::getFunctionType() const {
   return cast<FunctionType>(
       Ctx.getType(cast<llvm::Function>(Val)->getFunctionType()));
@@ -2621,6 +2626,10 @@ Value *Context::getOrCreateValueInternal(llvm::Value *LLVMV, llvm::User *U) {
       It->second = std::unique_ptr<BlockAddress>(
           new BlockAddress(cast<llvm::BlockAddress>(C), *this));
       return It->second.get();
+    case llvm::Value::ConstantTokenNoneVal:
+      It->second = std::unique_ptr<ConstantTokenNone>(
+          new ConstantTokenNone(cast<llvm::ConstantTokenNone>(C), *this));
+      return It->second.get();
     case llvm::Value::ConstantAggregateZeroVal: {
       auto *CAZ = cast<llvm::ConstantAggregateZero>(C);
       It->second = std::unique_ptr<ConstantAggregateZero>(

llvm/unittests/SandboxIR/SandboxIRTest.cpp

@@ -777,6 +777,30 @@ define void @foo(ptr %ptr) {
   EXPECT_EQ(LookupBB2Addr, nullptr);
 }
 
+TEST_F(SandboxIRTest, ConstantTokenNone) {
+  parseIR(C, R"IR(
+define void @foo(ptr %ptr) {
+ bb0:
+   %cs = catchswitch within none [label %handler] unwind to caller
+ handler:
+   ret void
+}
+)IR");
+  Function &LLVMF = *M->getFunction("foo");
+  sandboxir::Context Ctx(C);
+
+  [[maybe_unused]] auto &F = *Ctx.createFunction(&LLVMF);
+  auto *BB0 = cast<sandboxir::BasicBlock>(
+      Ctx.getValue(getBasicBlockByName(LLVMF, "bb0")));
+  auto *CS = cast<sandboxir::CatchSwitchInst>(&*BB0->begin());
+
+  // Check classof(), creation, getFunction(), getBasicBlock().
+  auto *CTN = cast<sandboxir::ConstantTokenNone>(CS->getParentPad());
+  // Check get().
+  auto *NewCTN = sandboxir::ConstantTokenNone::get(Ctx);
+  EXPECT_EQ(NewCTN, CTN);
+}
+
 TEST_F(SandboxIRTest, Use) {
   parseIR(C, R"IR(
 define i32 @foo(i32 %v0, i32 %v1) {