unittests/IR/ValueHandleTest.cpp

   1 //===- ValueHandleTest.cpp - ValueHandle tests ----------------------------===//
   2 //
   3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
   4 // See https://llvm.org/LICENSE.txt for license information.
   5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
   6 //
   7 //===----------------------------------------------------------------------===//
   8
   9 #include "llvm/IR/ValueHandle.h"
  10 #include "llvm/IR/Constants.h"
  11 #include "llvm/IR/Instructions.h"
  12 #include "llvm/IR/LLVMContext.h"
  13 #include "gtest/gtest.h"
  14 #include <memory>
  15
  16 using namespace llvm;
  17
  18 namespace {
  19
  20 class ValueHandle : public testing::Test {
  21 protected:
  22   LLVMContext Context;
  23   Constant *ConstantV;
  24   std::unique_ptr<BitCastInst> BitcastV;
  25
  26   ValueHandle()
  27       : ConstantV(ConstantInt::get(Type::getInt32Ty(Context), 0)),
  28         BitcastV(new BitCastInst(ConstantV, Type::getInt32Ty(Context))) {}
  29 };
  30
  31 class ConcreteCallbackVH final : public CallbackVH {
  32 public:
  33   ConcreteCallbackVH(Value *V) : CallbackVH(V) {}
  34 };
  35
  36 TEST_F(ValueHandle, WeakVH_BasicOperation) {
  37   WeakVH WVH(BitcastV.get());
  38   EXPECT_EQ(BitcastV.get(), WVH);
  39   WVH = ConstantV;
  40   EXPECT_EQ(ConstantV, WVH);
  41
  42   // Make sure I can call a method on the underlying Value.  It
  43   // doesn't matter which method.
  44   EXPECT_EQ(Type::getInt32Ty(Context), WVH->getType());
  45   EXPECT_EQ(Type::getInt32Ty(Context), (*WVH).getType());
  46
  47   WVH = BitcastV.get();
  48   BitcastV->replaceAllUsesWith(ConstantV);
  49   EXPECT_EQ(WVH, BitcastV.get());
  50   BitcastV.reset();
  51   EXPECT_EQ(WVH, nullptr);
  52 }
  53
  54 TEST_F(ValueHandle, WeakTrackingVH_BasicOperation) {
  55   WeakTrackingVH WVH(BitcastV.get());
  56   EXPECT_EQ(BitcastV.get(), WVH);
  57   WVH = ConstantV;
  58   EXPECT_EQ(ConstantV, WVH);
  59
  60   // Make sure I can call a method on the underlying Value.  It
  61   // doesn't matter which method.
  62   EXPECT_EQ(Type::getInt32Ty(Context), WVH->getType());
  63   EXPECT_EQ(Type::getInt32Ty(Context), (*WVH).getType());
  64 }
  65
  66 TEST_F(ValueHandle, WeakTrackingVH_Comparisons) {
  67   WeakTrackingVH BitcastWVH(BitcastV.get());
  68   WeakTrackingVH ConstantWVH(ConstantV);
  69
  70   EXPECT_TRUE(BitcastWVH == BitcastWVH);
  71   EXPECT_TRUE(BitcastV.get() == BitcastWVH);
  72   EXPECT_TRUE(BitcastWVH == BitcastV.get());
  73   EXPECT_FALSE(BitcastWVH == ConstantWVH);
  74
  75   EXPECT_TRUE(BitcastWVH != ConstantWVH);
  76   EXPECT_TRUE(BitcastV.get() != ConstantWVH);
  77   EXPECT_TRUE(BitcastWVH != ConstantV);
  78   EXPECT_FALSE(BitcastWVH != BitcastWVH);
  79
  80   // Cast to Value* so comparisons work.
  81   Value *BV = BitcastV.get();
  82   Value *CV = ConstantV;
  83   EXPECT_EQ(BV < CV, BitcastWVH < ConstantWVH);
  84   EXPECT_EQ(BV <= CV, BitcastWVH <= ConstantWVH);
  85   EXPECT_EQ(BV > CV, BitcastWVH > ConstantWVH);
  86   EXPECT_EQ(BV >= CV, BitcastWVH >= ConstantWVH);
  87
  88   EXPECT_EQ(BV < CV, BitcastV.get() < ConstantWVH);
  89   EXPECT_EQ(BV <= CV, BitcastV.get() <= ConstantWVH);
  90   EXPECT_EQ(BV > CV, BitcastV.get() > ConstantWVH);
  91   EXPECT_EQ(BV >= CV, BitcastV.get() >= ConstantWVH);
  92
  93   EXPECT_EQ(BV < CV, BitcastWVH < ConstantV);
  94   EXPECT_EQ(BV <= CV, BitcastWVH <= ConstantV);
  95   EXPECT_EQ(BV > CV, BitcastWVH > ConstantV);
  96   EXPECT_EQ(BV >= CV, BitcastWVH >= ConstantV);
  97 }
  98
  99 TEST_F(ValueHandle, WeakTrackingVH_FollowsRAUW) {
 100   WeakTrackingVH WVH(BitcastV.get());
 101   WeakTrackingVH WVH_Copy(WVH);
 102   WeakTrackingVH WVH_Recreated(BitcastV.get());
 103   BitcastV->replaceAllUsesWith(ConstantV);
 104   EXPECT_EQ(ConstantV, WVH);
 105   EXPECT_EQ(ConstantV, WVH_Copy);
 106   EXPECT_EQ(ConstantV, WVH_Recreated);
 107 }
 108
 109 TEST_F(ValueHandle, WeakTrackingVH_NullOnDeletion) {
 110   WeakTrackingVH WVH(BitcastV.get());
 111   WeakTrackingVH WVH_Copy(WVH);
 112   WeakTrackingVH WVH_Recreated(BitcastV.get());
 113   BitcastV.reset();
 114   Value *null_value = nullptr;
 115   EXPECT_EQ(null_value, WVH);
 116   EXPECT_EQ(null_value, WVH_Copy);
 117   EXPECT_EQ(null_value, WVH_Recreated);
 118 }
 119
 120
 121 TEST_F(ValueHandle, AssertingVH_BasicOperation) {
 122   AssertingVH<CastInst> AVH(BitcastV.get());
 123   CastInst *implicit_to_exact_type = AVH;
 124   (void)implicit_to_exact_type;  // Avoid warning.
 125
 126   AssertingVH<Value> GenericAVH(BitcastV.get());
 127   EXPECT_EQ(BitcastV.get(), GenericAVH);
 128   GenericAVH = ConstantV;
 129   EXPECT_EQ(ConstantV, GenericAVH);
 130
 131   // Make sure I can call a method on the underlying CastInst.  It
 132   // doesn't matter which method.
 133   EXPECT_FALSE(AVH->mayWriteToMemory());
 134   EXPECT_FALSE((*AVH).mayWriteToMemory());
 135 }
 136
 137 TEST_F(ValueHandle, AssertingVH_Const) {
 138   const CastInst *ConstBitcast = BitcastV.get();
 139   AssertingVH<const CastInst> AVH(ConstBitcast);
 140   const CastInst *implicit_to_exact_type = AVH;
 141   (void)implicit_to_exact_type;  // Avoid warning.
 142 }
 143
 144 TEST_F(ValueHandle, AssertingVH_Comparisons) {
 145   AssertingVH<Value> BitcastAVH(BitcastV.get());
 146   AssertingVH<Value> ConstantAVH(ConstantV);
 147
 148   EXPECT_TRUE(BitcastAVH == BitcastAVH);
 149   EXPECT_TRUE(BitcastV.get() == BitcastAVH);
 150   EXPECT_TRUE(BitcastAVH == BitcastV.get());
 151   EXPECT_FALSE(BitcastAVH == ConstantAVH);
 152
 153   EXPECT_TRUE(BitcastAVH != ConstantAVH);
 154   EXPECT_TRUE(BitcastV.get() != ConstantAVH);
 155   EXPECT_TRUE(BitcastAVH != ConstantV);
 156   EXPECT_FALSE(BitcastAVH != BitcastAVH);
 157
 158   // Cast to Value* so comparisons work.
 159   Value *BV = BitcastV.get();
 160   Value *CV = ConstantV;
 161   EXPECT_EQ(BV < CV, BitcastAVH < ConstantAVH);
 162   EXPECT_EQ(BV <= CV, BitcastAVH <= ConstantAVH);
 163   EXPECT_EQ(BV > CV, BitcastAVH > ConstantAVH);
 164   EXPECT_EQ(BV >= CV, BitcastAVH >= ConstantAVH);
 165
 166   EXPECT_EQ(BV < CV, BitcastV.get() < ConstantAVH);
 167   EXPECT_EQ(BV <= CV, BitcastV.get() <= ConstantAVH);
 168   EXPECT_EQ(BV > CV, BitcastV.get() > ConstantAVH);
 169   EXPECT_EQ(BV >= CV, BitcastV.get() >= ConstantAVH);
 170
 171   EXPECT_EQ(BV < CV, BitcastAVH < ConstantV);
 172   EXPECT_EQ(BV <= CV, BitcastAVH <= ConstantV);
 173   EXPECT_EQ(BV > CV, BitcastAVH > ConstantV);
 174   EXPECT_EQ(BV >= CV, BitcastAVH >= ConstantV);
 175 }
 176
 177 TEST_F(ValueHandle, AssertingVH_DoesNotFollowRAUW) {
 178   AssertingVH<Value> AVH(BitcastV.get());
 179   BitcastV->replaceAllUsesWith(ConstantV);
 180   EXPECT_EQ(BitcastV.get(), AVH);
 181 }
 182
 183 #ifdef NDEBUG
 184
 185 TEST_F(ValueHandle, AssertingVH_ReducesToPointer) {
 186   EXPECT_EQ(sizeof(CastInst *), sizeof(AssertingVH<CastInst>));
 187 }
 188
 189 #else  // !NDEBUG
 190
 191 #ifdef GTEST_HAS_DEATH_TEST
 192
 193 TEST_F(ValueHandle, AssertingVH_Asserts) {
 194   AssertingVH<Value> AVH(BitcastV.get());
 195   EXPECT_DEATH({BitcastV.reset();},
 196                "An asserting value handle still pointed to this value!");
 197   AssertingVH<Value> Copy(AVH);
 198   AVH = nullptr;
 199   EXPECT_DEATH({BitcastV.reset();},
 200                "An asserting value handle still pointed to this value!");
 201   Copy = nullptr;
 202   BitcastV.reset();
 203 }
 204
 205 #endif  // GTEST_HAS_DEATH_TEST
 206
 207 #endif  // NDEBUG
 208
 209 TEST_F(ValueHandle, CallbackVH_BasicOperation) {
 210   ConcreteCallbackVH CVH(BitcastV.get());
 211   EXPECT_EQ(BitcastV.get(), CVH);
 212   CVH = ConstantV;
 213   EXPECT_EQ(ConstantV, CVH);
 214
 215   // Make sure I can call a method on the underlying Value.  It
 216   // doesn't matter which method.
 217   EXPECT_EQ(Type::getInt32Ty(Context), CVH->getType());
 218   EXPECT_EQ(Type::getInt32Ty(Context), (*CVH).getType());
 219 }
 220
 221 TEST_F(ValueHandle, CallbackVH_Comparisons) {
 222   ConcreteCallbackVH BitcastCVH(BitcastV.get());
 223   ConcreteCallbackVH ConstantCVH(ConstantV);
 224
 225   EXPECT_TRUE(BitcastCVH == BitcastCVH);
 226   EXPECT_TRUE(BitcastV.get() == BitcastCVH);
 227   EXPECT_TRUE(BitcastCVH == BitcastV.get());
 228   EXPECT_FALSE(BitcastCVH == ConstantCVH);
 229
 230   EXPECT_TRUE(BitcastCVH != ConstantCVH);
 231   EXPECT_TRUE(BitcastV.get() != ConstantCVH);
 232   EXPECT_TRUE(BitcastCVH != ConstantV);
 233   EXPECT_FALSE(BitcastCVH != BitcastCVH);
 234
 235   // Cast to Value* so comparisons work.
 236   Value *BV = BitcastV.get();
 237   Value *CV = ConstantV;
 238   EXPECT_EQ(BV < CV, BitcastCVH < ConstantCVH);
 239   EXPECT_EQ(BV <= CV, BitcastCVH <= ConstantCVH);
 240   EXPECT_EQ(BV > CV, BitcastCVH > ConstantCVH);
 241   EXPECT_EQ(BV >= CV, BitcastCVH >= ConstantCVH);
 242
 243   EXPECT_EQ(BV < CV, BitcastV.get() < ConstantCVH);
 244   EXPECT_EQ(BV <= CV, BitcastV.get() <= ConstantCVH);
 245   EXPECT_EQ(BV > CV, BitcastV.get() > ConstantCVH);
 246   EXPECT_EQ(BV >= CV, BitcastV.get() >= ConstantCVH);
 247
 248   EXPECT_EQ(BV < CV, BitcastCVH < ConstantV);
 249   EXPECT_EQ(BV <= CV, BitcastCVH <= ConstantV);
 250   EXPECT_EQ(BV > CV, BitcastCVH > ConstantV);
 251   EXPECT_EQ(BV >= CV, BitcastCVH >= ConstantV);
 252 }
 253
 254 TEST_F(ValueHandle, CallbackVH_CallbackOnDeletion) {
 255   class RecordingVH final : public CallbackVH {
 256   public:
 257     int DeletedCalls;
 258     int AURWCalls;
 259
 260     RecordingVH() : DeletedCalls(0), AURWCalls(0) {}
 261     RecordingVH(Value *V) : CallbackVH(V), DeletedCalls(0), AURWCalls(0) {}
 262
 263   private:
 264     void deleted() override {
 265       DeletedCalls++;
 266       CallbackVH::deleted();
 267     }
 268     void allUsesReplacedWith(Value *) override { AURWCalls++; }
 269   };
 270
 271   RecordingVH RVH;
 272   RVH = BitcastV.get();
 273   EXPECT_EQ(0, RVH.DeletedCalls);
 274   EXPECT_EQ(0, RVH.AURWCalls);
 275   BitcastV.reset();
 276   EXPECT_EQ(1, RVH.DeletedCalls);
 277   EXPECT_EQ(0, RVH.AURWCalls);
 278 }
 279
 280 TEST_F(ValueHandle, CallbackVH_CallbackOnRAUW) {
 281   class RecordingVH final : public CallbackVH {
 282   public:
 283     int DeletedCalls;
 284     Value *AURWArgument;
 285
 286     RecordingVH() : DeletedCalls(0), AURWArgument(nullptr) {}
 287     RecordingVH(Value *V)
 288       : CallbackVH(V), DeletedCalls(0), AURWArgument(nullptr) {}
 289
 290   private:
 291     void deleted() override {
 292       DeletedCalls++;
 293       CallbackVH::deleted();
 294     }
 295     void allUsesReplacedWith(Value *new_value) override {
 296       EXPECT_EQ(nullptr, AURWArgument);
 297       AURWArgument = new_value;
 298     }
 299   };
 300
 301   RecordingVH RVH;
 302   RVH = BitcastV.get();
 303   EXPECT_EQ(0, RVH.DeletedCalls);
 304   EXPECT_EQ(nullptr, RVH.AURWArgument);
 305   BitcastV->replaceAllUsesWith(ConstantV);
 306   EXPECT_EQ(0, RVH.DeletedCalls);
 307   EXPECT_EQ(ConstantV, RVH.AURWArgument);
 308 }
 309
 310 TEST_F(ValueHandle, CallbackVH_DeletionCanRAUW) {
 311   class RecoveringVH final : public CallbackVH {
 312   public:
 313     int DeletedCalls;
 314     Value *AURWArgument;
 315     LLVMContext *Context;
 316
 317     RecoveringVH(LLVMContext &TheContext)
 318         : DeletedCalls(0), AURWArgument(nullptr), Context(&TheContext) {}
 319
 320     RecoveringVH(LLVMContext &TheContext, Value *V)
 321         : CallbackVH(V), DeletedCalls(0), AURWArgument(nullptr),
 322           Context(&TheContext) {}
 323
 324   private:
 325     void deleted() override {
 326       getValPtr()->replaceAllUsesWith(
 327           Constant::getNullValue(Type::getInt32Ty(*Context)));
 328       setValPtr(nullptr);
 329     }
 330     void allUsesReplacedWith(Value *new_value) override {
 331       ASSERT_TRUE(nullptr != getValPtr());
 332       EXPECT_EQ(1U, getValPtr()->getNumUses());
 333       EXPECT_EQ(nullptr, AURWArgument);
 334       AURWArgument = new_value;
 335     }
 336   };
 337
 338   // Normally, if a value has uses, deleting it will crash.  However, we can use
 339   // a CallbackVH to remove the uses before the check for no uses.
 340   RecoveringVH RVH(Context);
 341   RVH = RecoveringVH(Context, BitcastV.get());
 342   std::unique_ptr<BinaryOperator> BitcastUser(BinaryOperator::CreateAdd(
 343       RVH, Constant::getNullValue(Type::getInt32Ty(Context))));
 344   EXPECT_EQ(BitcastV.get(), BitcastUser->getOperand(0));
 345   BitcastV.reset();  // Would crash without the ValueHandler.
 346   EXPECT_EQ(Constant::getNullValue(Type::getInt32Ty(Context)),
 347             RVH.AURWArgument);
 348   EXPECT_EQ(Constant::getNullValue(Type::getInt32Ty(Context)),
 349             BitcastUser->getOperand(0));
 350 }
 351
 352 TEST_F(ValueHandle, DestroyingOtherVHOnSameValueDoesntBreakIteration) {
 353   // When a CallbackVH modifies other ValueHandles in its callbacks,
 354   // that shouldn't interfere with non-modified ValueHandles receiving
 355   // their appropriate callbacks.
 356   //
 357   // We create the active CallbackVH in the middle of a palindromic
 358   // arrangement of other VHs so that the bad behavior would be
 359   // triggered in whichever order callbacks run.
 360
 361   class DestroyingVH final : public CallbackVH {
 362   public:
 363     std::unique_ptr<WeakTrackingVH> ToClear[2];
 364     DestroyingVH(Value *V) {
 365       ToClear[0].reset(new WeakTrackingVH(V));
 366       setValPtr(V);
 367       ToClear[1].reset(new WeakTrackingVH(V));
 368     }
 369     void deleted() override {
 370       ToClear[0].reset();
 371       ToClear[1].reset();
 372       CallbackVH::deleted();
 373     }
 374     void allUsesReplacedWith(Value *) override {
 375       ToClear[0].reset();
 376       ToClear[1].reset();
 377     }
 378   };
 379
 380   {
 381     WeakTrackingVH ShouldBeVisited1(BitcastV.get());
 382     DestroyingVH C(BitcastV.get());
 383     WeakTrackingVH ShouldBeVisited2(BitcastV.get());
 384
 385     BitcastV->replaceAllUsesWith(ConstantV);
 386     EXPECT_EQ(ConstantV, static_cast<Value*>(ShouldBeVisited1));
 387     EXPECT_EQ(ConstantV, static_cast<Value*>(ShouldBeVisited2));
 388   }
 389
 390   {
 391     WeakTrackingVH ShouldBeVisited1(BitcastV.get());
 392     DestroyingVH C(BitcastV.get());
 393     WeakTrackingVH ShouldBeVisited2(BitcastV.get());
 394
 395     BitcastV.reset();
 396     EXPECT_EQ(nullptr, static_cast<Value*>(ShouldBeVisited1));
 397     EXPECT_EQ(nullptr, static_cast<Value*>(ShouldBeVisited2));
 398   }
 399 }
 400
 401 TEST_F(ValueHandle, AssertingVHCheckedLast) {
 402   // If a CallbackVH exists to clear out a group of AssertingVHs on
 403   // Value deletion, the CallbackVH should get a chance to do so
 404   // before the AssertingVHs assert.
 405
 406   class ClearingVH final : public CallbackVH {
 407   public:
 408     AssertingVH<Value> *ToClear[2];
 409     ClearingVH(Value *V,
 410                AssertingVH<Value> &A0, AssertingVH<Value> &A1)
 411       : CallbackVH(V) {
 412       ToClear[0] = &A0;
 413       ToClear[1] = &A1;
 414     }
 415
 416     void deleted() override {
 417       *ToClear[0] = nullptr;
 418       *ToClear[1] = nullptr;
 419       CallbackVH::deleted();
 420     }
 421   };
 422
 423   AssertingVH<Value> A1, A2;
 424   A1 = BitcastV.get();
 425   ClearingVH C(BitcastV.get(), A1, A2);
 426   A2 = BitcastV.get();
 427   // C.deleted() should run first, clearing the two AssertingVHs,
 428   // which should prevent them from asserting.
 429   BitcastV.reset();
 430 }
 431
 432 TEST_F(ValueHandle, PoisoningVH_BasicOperation) {
 433   PoisoningVH<CastInst> VH(BitcastV.get());
 434   CastInst *implicit_to_exact_type = VH;
 435   (void)implicit_to_exact_type; // Avoid warning.
 436
 437   PoisoningVH<Value> GenericVH(BitcastV.get());
 438   EXPECT_EQ(BitcastV.get(), GenericVH);
 439   GenericVH = ConstantV;
 440   EXPECT_EQ(ConstantV, GenericVH);
 441
 442   // Make sure I can call a method on the underlying CastInst.  It
 443   // doesn't matter which method.
 444   EXPECT_FALSE(VH->mayWriteToMemory());
 445   EXPECT_FALSE((*VH).mayWriteToMemory());
 446 }
 447
 448 TEST_F(ValueHandle, PoisoningVH_Const) {
 449   const CastInst *ConstBitcast = BitcastV.get();
 450   PoisoningVH<const CastInst> VH(ConstBitcast);
 451   const CastInst *implicit_to_exact_type = VH;
 452   (void)implicit_to_exact_type; // Avoid warning.
 453 }
 454
 455 TEST_F(ValueHandle, PoisoningVH_Comparisons) {
 456   PoisoningVH<Value> BitcastVH(BitcastV.get());
 457   PoisoningVH<Value> ConstantVH(ConstantV);
 458
 459   EXPECT_TRUE(BitcastVH == BitcastVH);
 460   EXPECT_TRUE(BitcastV.get() == BitcastVH);
 461   EXPECT_TRUE(BitcastVH == BitcastV.get());
 462   EXPECT_FALSE(BitcastVH == ConstantVH);
 463
 464   EXPECT_TRUE(BitcastVH != ConstantVH);
 465   EXPECT_TRUE(BitcastV.get() != ConstantVH);
 466   EXPECT_TRUE(BitcastVH != ConstantV);
 467   EXPECT_FALSE(BitcastVH != BitcastVH);
 468
 469   // Cast to Value* so comparisons work.
 470   Value *BV = BitcastV.get();
 471   Value *CV = ConstantV;
 472   EXPECT_EQ(BV < CV, BitcastVH < ConstantVH);
 473   EXPECT_EQ(BV <= CV, BitcastVH <= ConstantVH);
 474   EXPECT_EQ(BV > CV, BitcastVH > ConstantVH);
 475   EXPECT_EQ(BV >= CV, BitcastVH >= ConstantVH);
 476
 477   EXPECT_EQ(BV < CV, BitcastV.get() < ConstantVH);
 478   EXPECT_EQ(BV <= CV, BitcastV.get() <= ConstantVH);
 479   EXPECT_EQ(BV > CV, BitcastV.get() > ConstantVH);
 480   EXPECT_EQ(BV >= CV, BitcastV.get() >= ConstantVH);
 481
 482   EXPECT_EQ(BV < CV, BitcastVH < ConstantV);
 483   EXPECT_EQ(BV <= CV, BitcastVH <= ConstantV);
 484   EXPECT_EQ(BV > CV, BitcastVH > ConstantV);
 485   EXPECT_EQ(BV >= CV, BitcastVH >= ConstantV);
 486 }
 487
 488 TEST_F(ValueHandle, PoisoningVH_DoesNotFollowRAUW) {
 489   PoisoningVH<Value> VH(BitcastV.get());
 490   BitcastV->replaceAllUsesWith(ConstantV);
 491   EXPECT_TRUE(DenseMapInfo<PoisoningVH<Value>>::isEqual(VH, BitcastV.get()));
 492 }
 493
 494 #ifdef NDEBUG
 495
 496 TEST_F(ValueHandle, PoisoningVH_ReducesToPointer) {
 497   EXPECT_EQ(sizeof(CastInst *), sizeof(PoisoningVH<CastInst>));
 498 }
 499
 500 #else // !NDEBUG
 501
 502 TEST_F(ValueHandle, TrackingVH_Tracks) {
 503   TrackingVH<Value> VH(BitcastV.get());
 504   BitcastV->replaceAllUsesWith(ConstantV);
 505   EXPECT_EQ(VH, ConstantV);
 506 }
 507
 508 #ifdef GTEST_HAS_DEATH_TEST
 509
 510 TEST_F(ValueHandle, PoisoningVH_Asserts) {
 511   PoisoningVH<Value> VH(BitcastV.get());
 512
 513   // The poisoned handle shouldn't assert when the value is deleted.
 514   BitcastV.reset(new BitCastInst(ConstantV, Type::getInt32Ty(Context)));
 515   // But should when we access the handle.
 516   EXPECT_DEATH((void)*VH, "Accessed a poisoned value handle!");
 517
 518   // Now check that poison catches RAUW.
 519   VH = BitcastV.get();
 520   // The replace doesn't trigger anything immediately.
 521   BitcastV->replaceAllUsesWith(ConstantV);
 522   // But a use does.
 523   EXPECT_DEATH((void)*VH, "Accessed a poisoned value handle!");
 524
 525   // Don't clear anything out here as destroying the handles should be fine.
 526 }
 527
 528 TEST_F(ValueHandle, TrackingVH_Asserts) {
 529   {
 530     TrackingVH<Value> VH(BitcastV.get());
 531
 532     // The tracking handle shouldn't assert when the value is deleted.
 533     BitcastV.reset(new BitCastInst(ConstantV, Type::getInt32Ty(Context)));
 534     // But should when we access the handle.
 535     EXPECT_DEATH((void)*VH,
 536                  "TrackingVH must be non-null and valid on dereference!");
 537   }
 538
 539   {
 540     TrackingVH<Instruction> VH(BitcastV.get());
 541
 542     BitcastV->replaceAllUsesWith(ConstantV);
 543     EXPECT_DEATH((void)*VH,
 544                  "Tracked Value was replaced by one with an invalid type!");
 545   }
 546 }
 547
 548 #endif // GTEST_HAS_DEATH_TEST
 549
 550 #endif // NDEBUG
 551 }