unittests/ExecutionEngine/JIT/JITTest.cpp

   1 //===- JITTest.cpp - Unit tests for the JIT -------------------------------===//
   2 //
   3 //                     The LLVM Compiler Infrastructure
   4 //
   5 // This file is distributed under the University of Illinois Open Source
   6 // License. See LICENSE.TXT for details.
   7 //
   8 //===----------------------------------------------------------------------===//
   9
  10 #include "gtest/gtest.h"
  11 #include "llvm/ADT/OwningPtr.h"
  12 #include "llvm/ADT/SmallPtrSet.h"
  13 #include "llvm/Assembly/Parser.h"
  14 #include "llvm/BasicBlock.h"
  15 #include "llvm/Bitcode/ReaderWriter.h"
  16 #include "llvm/Constant.h"
  17 #include "llvm/Constants.h"
  18 #include "llvm/DerivedTypes.h"
  19 #include "llvm/ExecutionEngine/JIT.h"
  20 #include "llvm/ExecutionEngine/JITMemoryManager.h"
  21 #include "llvm/Function.h"
  22 #include "llvm/GlobalValue.h"
  23 #include "llvm/GlobalVariable.h"
  24 #include "llvm/LLVMContext.h"
  25 #include "llvm/Module.h"
  26 #include "llvm/Support/IRBuilder.h"
  27 #include "llvm/Support/MemoryBuffer.h"
  28 #include "llvm/Support/SourceMgr.h"
  29 #include "llvm/Support/TypeBuilder.h"
  30 #include "llvm/Target/TargetSelect.h"
  31 #include "llvm/Type.h"
  32
  33 #include <vector>
  34
  35 using namespace llvm;
  36
  37 namespace {
  38
  39 Function *makeReturnGlobal(std::string Name, GlobalVariable *G, Module *M) {
  40   std::vector<const Type*> params;
  41   const FunctionType *FTy = FunctionType::get(G->getType()->getElementType(),
  42                                               params, false);
  43   Function *F = Function::Create(FTy, GlobalValue::ExternalLinkage, Name, M);
  44   BasicBlock *Entry = BasicBlock::Create(M->getContext(), "entry", F);
  45   IRBuilder<> builder(Entry);
  46   Value *Load = builder.CreateLoad(G);
  47   const Type *GTy = G->getType()->getElementType();
  48   Value *Add = builder.CreateAdd(Load, ConstantInt::get(GTy, 1LL));
  49   builder.CreateStore(Add, G);
  50   builder.CreateRet(Add);
  51   return F;
  52 }
  53
  54 std::string DumpFunction(const Function *F) {
  55   std::string Result;
  56   raw_string_ostream(Result) << "" << *F;
  57   return Result;
  58 }
  59
  60 class RecordingJITMemoryManager : public JITMemoryManager {
  61   const OwningPtr<JITMemoryManager> Base;
  62 public:
  63   RecordingJITMemoryManager()
  64     : Base(JITMemoryManager::CreateDefaultMemManager()) {
  65     stubsAllocated = 0;
  66   }
  67
  68   virtual void setMemoryWritable() { Base->setMemoryWritable(); }
  69   virtual void setMemoryExecutable() { Base->setMemoryExecutable(); }
  70   virtual void setPoisonMemory(bool poison) { Base->setPoisonMemory(poison); }
  71   virtual void AllocateGOT() { Base->AllocateGOT(); }
  72   virtual uint8_t *getGOTBase() const { return Base->getGOTBase(); }
  73   struct StartFunctionBodyCall {
  74     StartFunctionBodyCall(uint8_t *Result, const Function *F,
  75                           uintptr_t ActualSize, uintptr_t ActualSizeResult)
  76       : Result(Result), F(F), F_dump(DumpFunction(F)),
  77         ActualSize(ActualSize), ActualSizeResult(ActualSizeResult) {}
  78     uint8_t *Result;
  79     const Function *F;
  80     std::string F_dump;
  81     uintptr_t ActualSize;
  82     uintptr_t ActualSizeResult;
  83   };
  84   std::vector<StartFunctionBodyCall> startFunctionBodyCalls;
  85   virtual uint8_t *startFunctionBody(const Function *F,
  86                                      uintptr_t &ActualSize) {
  87     uintptr_t InitialActualSize = ActualSize;
  88     uint8_t *Result = Base->startFunctionBody(F, ActualSize);
  89     startFunctionBodyCalls.push_back(
  90       StartFunctionBodyCall(Result, F, InitialActualSize, ActualSize));
  91     return Result;
  92   }
  93   int stubsAllocated;
  94   virtual uint8_t *allocateStub(const GlobalValue* F, unsigned StubSize,
  95                                 unsigned Alignment) {
  96     stubsAllocated++;
  97     return Base->allocateStub(F, StubSize, Alignment);
  98   }
  99   struct EndFunctionBodyCall {
 100     EndFunctionBodyCall(const Function *F, uint8_t *FunctionStart,
 101                         uint8_t *FunctionEnd)
 102       : F(F), F_dump(DumpFunction(F)),
 103         FunctionStart(FunctionStart), FunctionEnd(FunctionEnd) {}
 104     const Function *F;
 105     std::string F_dump;
 106     uint8_t *FunctionStart;
 107     uint8_t *FunctionEnd;
 108   };
 109   std::vector<EndFunctionBodyCall> endFunctionBodyCalls;
 110   virtual void endFunctionBody(const Function *F, uint8_t *FunctionStart,
 111                                uint8_t *FunctionEnd) {
 112     endFunctionBodyCalls.push_back(
 113       EndFunctionBodyCall(F, FunctionStart, FunctionEnd));
 114     Base->endFunctionBody(F, FunctionStart, FunctionEnd);
 115   }
 116   virtual uint8_t *allocateSpace(intptr_t Size, unsigned Alignment) {
 117     return Base->allocateSpace(Size, Alignment);
 118   }
 119   virtual uint8_t *allocateGlobal(uintptr_t Size, unsigned Alignment) {
 120     return Base->allocateGlobal(Size, Alignment);
 121   }
 122   struct DeallocateFunctionBodyCall {
 123     DeallocateFunctionBodyCall(const void *Body) : Body(Body) {}
 124     const void *Body;
 125   };
 126   std::vector<DeallocateFunctionBodyCall> deallocateFunctionBodyCalls;
 127   virtual void deallocateFunctionBody(void *Body) {
 128     deallocateFunctionBodyCalls.push_back(DeallocateFunctionBodyCall(Body));
 129     Base->deallocateFunctionBody(Body);
 130   }
 131   struct DeallocateExceptionTableCall {
 132     DeallocateExceptionTableCall(const void *ET) : ET(ET) {}
 133     const void *ET;
 134   };
 135   std::vector<DeallocateExceptionTableCall> deallocateExceptionTableCalls;
 136   virtual void deallocateExceptionTable(void *ET) {
 137     deallocateExceptionTableCalls.push_back(DeallocateExceptionTableCall(ET));
 138     Base->deallocateExceptionTable(ET);
 139   }
 140   struct StartExceptionTableCall {
 141     StartExceptionTableCall(uint8_t *Result, const Function *F,
 142                             uintptr_t ActualSize, uintptr_t ActualSizeResult)
 143       : Result(Result), F(F), F_dump(DumpFunction(F)),
 144         ActualSize(ActualSize), ActualSizeResult(ActualSizeResult) {}
 145     uint8_t *Result;
 146     const Function *F;
 147     std::string F_dump;
 148     uintptr_t ActualSize;
 149     uintptr_t ActualSizeResult;
 150   };
 151   std::vector<StartExceptionTableCall> startExceptionTableCalls;
 152   virtual uint8_t* startExceptionTable(const Function* F,
 153                                        uintptr_t &ActualSize) {
 154     uintptr_t InitialActualSize = ActualSize;
 155     uint8_t *Result = Base->startExceptionTable(F, ActualSize);
 156     startExceptionTableCalls.push_back(
 157       StartExceptionTableCall(Result, F, InitialActualSize, ActualSize));
 158     return Result;
 159   }
 160   struct EndExceptionTableCall {
 161     EndExceptionTableCall(const Function *F, uint8_t *TableStart,
 162                           uint8_t *TableEnd, uint8_t* FrameRegister)
 163       : F(F), F_dump(DumpFunction(F)),
 164         TableStart(TableStart), TableEnd(TableEnd),
 165         FrameRegister(FrameRegister) {}
 166     const Function *F;
 167     std::string F_dump;
 168     uint8_t *TableStart;
 169     uint8_t *TableEnd;
 170     uint8_t *FrameRegister;
 171   };
 172   std::vector<EndExceptionTableCall> endExceptionTableCalls;
 173   virtual void endExceptionTable(const Function *F, uint8_t *TableStart,
 174                                  uint8_t *TableEnd, uint8_t* FrameRegister) {
 175       endExceptionTableCalls.push_back(
 176           EndExceptionTableCall(F, TableStart, TableEnd, FrameRegister));
 177     return Base->endExceptionTable(F, TableStart, TableEnd, FrameRegister);
 178   }
 179 };
 180
 181 bool LoadAssemblyInto(Module *M, const char *assembly) {
 182   SMDiagnostic Error;
 183   bool success =
 184     NULL != ParseAssemblyString(assembly, M, Error, M->getContext());
 185   std::string errMsg;
 186   raw_string_ostream os(errMsg);
 187   Error.Print("", os);
 188   EXPECT_TRUE(success) << os.str();
 189   return success;
 190 }
 191
 192 class JITTest : public testing::Test {
 193  protected:
 194   virtual void SetUp() {
 195     M = new Module("<main>", Context);
 196     RJMM = new RecordingJITMemoryManager;
 197     RJMM->setPoisonMemory(true);
 198     std::string Error;
 199     TheJIT.reset(EngineBuilder(M).setEngineKind(EngineKind::JIT)
 200                  .setJITMemoryManager(RJMM)
 201                  .setErrorStr(&Error).create());
 202     ASSERT_TRUE(TheJIT.get() != NULL) << Error;
 203   }
 204
 205   void LoadAssembly(const char *assembly) {
 206     LoadAssemblyInto(M, assembly);
 207   }
 208
 209   LLVMContext Context;
 210   Module *M;  // Owned by ExecutionEngine.
 211   RecordingJITMemoryManager *RJMM;
 212   OwningPtr<ExecutionEngine> TheJIT;
 213 };
 214
 215 // Regression test for a bug.  The JIT used to allocate globals inside the same
 216 // memory block used for the function, and when the function code was freed,
 217 // the global was left in the same place.  This test allocates a function
 218 // that uses and global, deallocates it, and then makes sure that the global
 219 // stays alive after that.
 220 TEST(JIT, GlobalInFunction) {
 221   LLVMContext context;
 222   Module *M = new Module("<main>", context);
 223
 224   JITMemoryManager *MemMgr = JITMemoryManager::CreateDefaultMemManager();
 225   // Tell the memory manager to poison freed memory so that accessing freed
 226   // memory is more easily tested.
 227   MemMgr->setPoisonMemory(true);
 228   std::string Error;
 229   OwningPtr<ExecutionEngine> JIT(EngineBuilder(M)
 230                                  .setEngineKind(EngineKind::JIT)
 231                                  .setErrorStr(&Error)
 232                                  .setJITMemoryManager(MemMgr)
 233                                  // The next line enables the fix:
 234                                  .setAllocateGVsWithCode(false)
 235                                  .create());
 236   ASSERT_EQ(Error, "");
 237
 238   // Create a global variable.
 239   const Type *GTy = Type::getInt32Ty(context);
 240   GlobalVariable *G = new GlobalVariable(
 241       *M,
 242       GTy,
 243       false,  // Not constant.
 244       GlobalValue::InternalLinkage,
 245       Constant::getNullValue(GTy),
 246       "myglobal");
 247
 248   // Make a function that points to a global.
 249   Function *F1 = makeReturnGlobal("F1", G, M);
 250
 251   // Get the pointer to the native code to force it to JIT the function and
 252   // allocate space for the global.
 253   void (*F1Ptr)() =
 254       reinterpret_cast<void(*)()>((intptr_t)JIT->getPointerToFunction(F1));
 255
 256   // Since F1 was codegen'd, a pointer to G should be available.
 257   int32_t *GPtr = (int32_t*)JIT->getPointerToGlobalIfAvailable(G);
 258   ASSERT_NE((int32_t*)NULL, GPtr);
 259   EXPECT_EQ(0, *GPtr);
 260
 261   // F1() should increment G.
 262   F1Ptr();
 263   EXPECT_EQ(1, *GPtr);
 264
 265   // Make a second function identical to the first, referring to the same
 266   // global.
 267   Function *F2 = makeReturnGlobal("F2", G, M);
 268   void (*F2Ptr)() =
 269       reinterpret_cast<void(*)()>((intptr_t)JIT->getPointerToFunction(F2));
 270
 271   // F2() should increment G.
 272   F2Ptr();
 273   EXPECT_EQ(2, *GPtr);
 274
 275   // Deallocate F1.
 276   JIT->freeMachineCodeForFunction(F1);
 277
 278   // F2() should *still* increment G.
 279   F2Ptr();
 280   EXPECT_EQ(3, *GPtr);
 281 }
 282
 283 int PlusOne(int arg) {
 284   return arg + 1;
 285 }
 286
 287 TEST_F(JITTest, FarCallToKnownFunction) {
 288   // x86-64 can only make direct calls to functions within 32 bits of
 289   // the current PC.  To call anything farther away, we have to load
 290   // the address into a register and call through the register.  The
 291   // current JIT does this by allocating a stub for any far call.
 292   // There was a bug in which the JIT tried to emit a direct call when
 293   // the target was already in the JIT's global mappings and lazy
 294   // compilation was disabled.
 295
 296   Function *KnownFunction = Function::Create(
 297       TypeBuilder<int(int), false>::get(Context),
 298       GlobalValue::ExternalLinkage, "known", M);
 299   TheJIT->addGlobalMapping(KnownFunction, (void*)(intptr_t)PlusOne);
 300
 301   // int test() { return known(7); }
 302   Function *TestFunction = Function::Create(
 303       TypeBuilder<int(), false>::get(Context),
 304       GlobalValue::ExternalLinkage, "test", M);
 305   BasicBlock *Entry = BasicBlock::Create(Context, "entry", TestFunction);
 306   IRBuilder<> Builder(Entry);
 307   Value *result = Builder.CreateCall(
 308       KnownFunction,
 309       ConstantInt::get(TypeBuilder<int, false>::get(Context), 7));
 310   Builder.CreateRet(result);
 311
 312   TheJIT->DisableLazyCompilation(true);
 313   int (*TestFunctionPtr)() = reinterpret_cast<int(*)()>(
 314       (intptr_t)TheJIT->getPointerToFunction(TestFunction));
 315   // This used to crash in trying to call PlusOne().
 316   EXPECT_EQ(8, TestFunctionPtr());
 317 }
 318
 319 // Test a function C which calls A and B which call each other.
 320 TEST_F(JITTest, NonLazyCompilationStillNeedsStubs) {
 321   TheJIT->DisableLazyCompilation(true);
 322
 323   const FunctionType *Func1Ty =
 324       cast<FunctionType>(TypeBuilder<void(void), false>::get(Context));
 325   std::vector<const Type*> arg_types;
 326   arg_types.push_back(Type::getInt1Ty(Context));
 327   const FunctionType *FuncTy = FunctionType::get(
 328       Type::getVoidTy(Context), arg_types, false);
 329   Function *Func1 = Function::Create(Func1Ty, Function::ExternalLinkage,
 330                                      "func1", M);
 331   Function *Func2 = Function::Create(FuncTy, Function::InternalLinkage,
 332                                      "func2", M);
 333   Function *Func3 = Function::Create(FuncTy, Function::InternalLinkage,
 334                                      "func3", M);
 335   BasicBlock *Block1 = BasicBlock::Create(Context, "block1", Func1);
 336   BasicBlock *Block2 = BasicBlock::Create(Context, "block2", Func2);
 337   BasicBlock *True2 = BasicBlock::Create(Context, "cond_true", Func2);
 338   BasicBlock *False2 = BasicBlock::Create(Context, "cond_false", Func2);
 339   BasicBlock *Block3 = BasicBlock::Create(Context, "block3", Func3);
 340   BasicBlock *True3 = BasicBlock::Create(Context, "cond_true", Func3);
 341   BasicBlock *False3 = BasicBlock::Create(Context, "cond_false", Func3);
 342
 343   // Make Func1 call Func2(0) and Func3(0).
 344   IRBuilder<> Builder(Block1);
 345   Builder.CreateCall(Func2, ConstantInt::getTrue(Context));
 346   Builder.CreateCall(Func3, ConstantInt::getTrue(Context));
 347   Builder.CreateRetVoid();
 348
 349   // void Func2(bool b) { if (b) { Func3(false); return; } return; }
 350   Builder.SetInsertPoint(Block2);
 351   Builder.CreateCondBr(Func2->arg_begin(), True2, False2);
 352   Builder.SetInsertPoint(True2);
 353   Builder.CreateCall(Func3, ConstantInt::getFalse(Context));
 354   Builder.CreateRetVoid();
 355   Builder.SetInsertPoint(False2);
 356   Builder.CreateRetVoid();
 357
 358   // void Func3(bool b) { if (b) { Func2(false); return; } return; }
 359   Builder.SetInsertPoint(Block3);
 360   Builder.CreateCondBr(Func3->arg_begin(), True3, False3);
 361   Builder.SetInsertPoint(True3);
 362   Builder.CreateCall(Func2, ConstantInt::getFalse(Context));
 363   Builder.CreateRetVoid();
 364   Builder.SetInsertPoint(False3);
 365   Builder.CreateRetVoid();
 366
 367   // Compile the function to native code
 368   void (*F1Ptr)() =
 369      reinterpret_cast<void(*)()>((intptr_t)TheJIT->getPointerToFunction(Func1));
 370
 371   F1Ptr();
 372 }
 373
 374 // Regression test for PR5162.  This used to trigger an AssertingVH inside the
 375 // JIT's Function to stub mapping.
 376 TEST_F(JITTest, NonLazyLeaksNoStubs) {
 377   TheJIT->DisableLazyCompilation(true);
 378
 379   // Create two functions with a single basic block each.
 380   const FunctionType *FuncTy =
 381       cast<FunctionType>(TypeBuilder<int(), false>::get(Context));
 382   Function *Func1 = Function::Create(FuncTy, Function::ExternalLinkage,
 383                                      "func1", M);
 384   Function *Func2 = Function::Create(FuncTy, Function::InternalLinkage,
 385                                      "func2", M);
 386   BasicBlock *Block1 = BasicBlock::Create(Context, "block1", Func1);
 387   BasicBlock *Block2 = BasicBlock::Create(Context, "block2", Func2);
 388
 389   // The first function calls the second and returns the result
 390   IRBuilder<> Builder(Block1);
 391   Value *Result = Builder.CreateCall(Func2);
 392   Builder.CreateRet(Result);
 393
 394   // The second function just returns a constant
 395   Builder.SetInsertPoint(Block2);
 396   Builder.CreateRet(ConstantInt::get(TypeBuilder<int, false>::get(Context),42));
 397
 398   // Compile the function to native code
 399   (void)TheJIT->getPointerToFunction(Func1);
 400
 401   // Free the JIT state for the functions
 402   TheJIT->freeMachineCodeForFunction(Func1);
 403   TheJIT->freeMachineCodeForFunction(Func2);
 404
 405   // Delete the first function (and show that is has no users)
 406   EXPECT_EQ(Func1->getNumUses(), 0u);
 407   Func1->eraseFromParent();
 408
 409   // Delete the second function (and show that it has no users - it had one,
 410   // func1 but that's gone now)
 411   EXPECT_EQ(Func2->getNumUses(), 0u);
 412   Func2->eraseFromParent();
 413 }
 414
 415 TEST_F(JITTest, ModuleDeletion) {
 416   TheJIT->DisableLazyCompilation(false);
 417   LoadAssembly("define void @main() { "
 418                "  call i32 @computeVal() "
 419                "  ret void "
 420                "} "
 421                " "
 422                "define internal i32 @computeVal()  { "
 423                "  ret i32 0 "
 424                "} ");
 425   Function *func = M->getFunction("main");
 426   TheJIT->getPointerToFunction(func);
 427   TheJIT->removeModule(M);
 428   delete M;
 429
 430   SmallPtrSet<const void*, 2> FunctionsDeallocated;
 431   for (unsigned i = 0, e = RJMM->deallocateFunctionBodyCalls.size();
 432        i != e; ++i) {
 433     FunctionsDeallocated.insert(RJMM->deallocateFunctionBodyCalls[i].Body);
 434   }
 435   for (unsigned i = 0, e = RJMM->startFunctionBodyCalls.size(); i != e; ++i) {
 436     EXPECT_TRUE(FunctionsDeallocated.count(
 437                   RJMM->startFunctionBodyCalls[i].Result))
 438       << "Function leaked: \n" << RJMM->startFunctionBodyCalls[i].F_dump;
 439   }
 440   EXPECT_EQ(RJMM->startFunctionBodyCalls.size(),
 441             RJMM->deallocateFunctionBodyCalls.size());
 442
 443   SmallPtrSet<const void*, 2> ExceptionTablesDeallocated;
 444   unsigned NumTablesDeallocated = 0;
 445   for (unsigned i = 0, e = RJMM->deallocateExceptionTableCalls.size();
 446        i != e; ++i) {
 447     ExceptionTablesDeallocated.insert(
 448         RJMM->deallocateExceptionTableCalls[i].ET);
 449     if (RJMM->deallocateExceptionTableCalls[i].ET != NULL) {
 450         // If JITEmitDebugInfo is off, we'll "deallocate" NULL, which doesn't
 451         // appear in startExceptionTableCalls.
 452         NumTablesDeallocated++;
 453     }
 454   }
 455   for (unsigned i = 0, e = RJMM->startExceptionTableCalls.size(); i != e; ++i) {
 456     EXPECT_TRUE(ExceptionTablesDeallocated.count(
 457                   RJMM->startExceptionTableCalls[i].Result))
 458       << "Function's exception table leaked: \n"
 459       << RJMM->startExceptionTableCalls[i].F_dump;
 460   }
 461   EXPECT_EQ(RJMM->startExceptionTableCalls.size(),
 462             NumTablesDeallocated);
 463 }
 464
 465 // ARM and PPC still emit stubs for calls since the target may be too far away
 466 // to call directly.  This #if can probably be removed when
 467 // http://llvm.org/PR5201 is fixed.
 468 #if !defined(__arm__) && !defined(__powerpc__) && !defined(__ppc__)
 469 typedef int (*FooPtr) ();
 470
 471 TEST_F(JITTest, NoStubs) {
 472   LoadAssembly("define void @bar() {"
 473                "entry: "
 474                "ret void"
 475                "}"
 476                " "
 477                "define i32 @foo() {"
 478                "entry:"
 479                "call void @bar()"
 480                "ret i32 undef"
 481                "}"
 482                " "
 483                "define i32 @main() {"
 484                "entry:"
 485                "%0 = call i32 @foo()"
 486                "call void @bar()"
 487                "ret i32 undef"
 488                "}");
 489   Function *foo = M->getFunction("foo");
 490   uintptr_t tmp = (uintptr_t)(TheJIT->getPointerToFunction(foo));
 491   FooPtr ptr = (FooPtr)(tmp);
 492
 493   (ptr)();
 494
 495   // We should now allocate no more stubs, we have the code to foo
 496   // and the existing stub for bar.
 497   int stubsBefore = RJMM->stubsAllocated;
 498   Function *func = M->getFunction("main");
 499   TheJIT->getPointerToFunction(func);
 500
 501   Function *bar = M->getFunction("bar");
 502   TheJIT->getPointerToFunction(bar);
 503
 504   ASSERT_EQ(stubsBefore, RJMM->stubsAllocated);
 505 }
 506 #endif  // !ARM && !PPC
 507
 508 TEST_F(JITTest, FunctionPointersOutliveTheirCreator) {
 509   TheJIT->DisableLazyCompilation(true);
 510   LoadAssembly("define i8()* @get_foo_addr() { "
 511                "  ret i8()* @foo "
 512                "} "
 513                " "
 514                "define i8 @foo() { "
 515                "  ret i8 42 "
 516                "} ");
 517   Function *F_get_foo_addr = M->getFunction("get_foo_addr");
 518
 519   typedef char(*fooT)();
 520   fooT (*get_foo_addr)() = reinterpret_cast<fooT(*)()>(
 521       (intptr_t)TheJIT->getPointerToFunction(F_get_foo_addr));
 522   fooT foo_addr = get_foo_addr();
 523
 524   // Now free get_foo_addr.  This should not free the machine code for foo or
 525   // any call stub returned as foo's canonical address.
 526   TheJIT->freeMachineCodeForFunction(F_get_foo_addr);
 527
 528   // Check by calling the reported address of foo.
 529   EXPECT_EQ(42, foo_addr());
 530
 531   // The reported address should also be the same as the result of a subsequent
 532   // getPointerToFunction(foo).
 533 #if 0
 534   // Fails until PR5126 is fixed:
 535   Function *F_foo = M->getFunction("foo");
 536   fooT foo = reinterpret_cast<fooT>(
 537       (intptr_t)TheJIT->getPointerToFunction(F_foo));
 538   EXPECT_EQ((intptr_t)foo, (intptr_t)foo_addr);
 539 #endif
 540 }
 541
 542 // ARM doesn't have an implementation of replaceMachineCodeForFunction(), so
 543 // recompileAndRelinkFunction doesn't work.
 544 #if !defined(__arm__)
 545 TEST_F(JITTest, FunctionIsRecompiledAndRelinked) {
 546   Function *F = Function::Create(TypeBuilder<int(void), false>::get(Context),
 547                                  GlobalValue::ExternalLinkage, "test", M);
 548   BasicBlock *Entry = BasicBlock::Create(Context, "entry", F);
 549   IRBuilder<> Builder(Entry);
 550   Value *Val = ConstantInt::get(TypeBuilder<int, false>::get(Context), 1);
 551   Builder.CreateRet(Val);
 552
 553   TheJIT->DisableLazyCompilation(true);
 554   // Compile the function once, and make sure it works.
 555   int (*OrigFPtr)() = reinterpret_cast<int(*)()>(
 556     (intptr_t)TheJIT->recompileAndRelinkFunction(F));
 557   EXPECT_EQ(1, OrigFPtr());
 558
 559   // Now change the function to return a different value.
 560   Entry->eraseFromParent();
 561   BasicBlock *NewEntry = BasicBlock::Create(Context, "new_entry", F);
 562   Builder.SetInsertPoint(NewEntry);
 563   Val = ConstantInt::get(TypeBuilder<int, false>::get(Context), 2);
 564   Builder.CreateRet(Val);
 565   // Recompile it, which should produce a new function pointer _and_ update the
 566   // old one.
 567   int (*NewFPtr)() = reinterpret_cast<int(*)()>(
 568     (intptr_t)TheJIT->recompileAndRelinkFunction(F));
 569
 570   EXPECT_EQ(2, NewFPtr())
 571     << "The new pointer should call the new version of the function";
 572   EXPECT_EQ(2, OrigFPtr())
 573     << "The old pointer's target should now jump to the new version";
 574 }
 575 #endif  // !defined(__arm__)
 576
 577 }  // anonymous namespace
 578 // This variable is intentionally defined differently in the statically-compiled
 579 // program from the IR input to the JIT to assert that the JIT doesn't use its
 580 // definition.
 581 extern "C" int32_t JITTest_AvailableExternallyGlobal;
 582 int32_t JITTest_AvailableExternallyGlobal = 42;
 583 namespace {
 584
 585 TEST_F(JITTest, AvailableExternallyGlobalIsntEmitted) {
 586   TheJIT->DisableLazyCompilation(true);
 587   LoadAssembly("@JITTest_AvailableExternallyGlobal = "
 588                "  available_externally global i32 7 "
 589                " "
 590                "define i32 @loader() { "
 591                "  %result = load i32* @JITTest_AvailableExternallyGlobal "
 592                "  ret i32 %result "
 593                "} ");
 594   Function *loaderIR = M->getFunction("loader");
 595
 596   int32_t (*loader)() = reinterpret_cast<int32_t(*)()>(
 597     (intptr_t)TheJIT->getPointerToFunction(loaderIR));
 598   EXPECT_EQ(42, loader()) << "func should return 42 from the external global,"
 599                           << " not 7 from the IR version.";
 600 }
 601
 602 }  // anonymous namespace
 603 // This function is intentionally defined differently in the statically-compiled
 604 // program from the IR input to the JIT to assert that the JIT doesn't use its
 605 // definition.
 606 extern "C" int32_t JITTest_AvailableExternallyFunction() {
 607   return 42;
 608 }
 609 namespace {
 610
 611 TEST_F(JITTest, AvailableExternallyFunctionIsntCompiled) {
 612   TheJIT->DisableLazyCompilation(true);
 613   LoadAssembly("define available_externally i32 "
 614                "    @JITTest_AvailableExternallyFunction() { "
 615                "  ret i32 7 "
 616                "} "
 617                " "
 618                "define i32 @func() { "
 619                "  %result = tail call i32 "
 620                "    @JITTest_AvailableExternallyFunction() "
 621                "  ret i32 %result "
 622                "} ");
 623   Function *funcIR = M->getFunction("func");
 624
 625   int32_t (*func)() = reinterpret_cast<int32_t(*)()>(
 626     (intptr_t)TheJIT->getPointerToFunction(funcIR));
 627   EXPECT_EQ(42, func()) << "func should return 42 from the static version,"
 628                         << " not 7 from the IR version.";
 629 }
 630
 631 TEST_F(JITTest, EscapedLazyStubStillCallable) {
 632   TheJIT->DisableLazyCompilation(false);
 633   LoadAssembly("define internal i32 @stubbed() { "
 634                "  ret i32 42 "
 635                "} "
 636                " "
 637                "define i32()* @get_stub() { "
 638                "  ret i32()* @stubbed "
 639                "} ");
 640   typedef int32_t(*StubTy)();
 641
 642   // Call get_stub() to get the address of @stubbed without actually JITting it.
 643   Function *get_stubIR = M->getFunction("get_stub");
 644   StubTy (*get_stub)() = reinterpret_cast<StubTy(*)()>(
 645     (intptr_t)TheJIT->getPointerToFunction(get_stubIR));
 646   StubTy stubbed = get_stub();
 647   // Now get_stubIR is the only reference to stubbed's stub.
 648   get_stubIR->eraseFromParent();
 649   // Now there are no references inside the JIT, but we've got a pointer outside
 650   // it.  The stub should be callable and return the right value.
 651   EXPECT_EQ(42, stubbed());
 652 }
 653
 654 // Converts the LLVM assembly to bitcode and returns it in a std::string.  An
 655 // empty string indicates an error.
 656 std::string AssembleToBitcode(LLVMContext &Context, const char *Assembly) {
 657   Module TempModule("TempModule", Context);
 658   if (!LoadAssemblyInto(&TempModule, Assembly)) {
 659     return "";
 660   }
 661
 662   std::string Result;
 663   raw_string_ostream OS(Result);
 664   WriteBitcodeToFile(&TempModule, OS);
 665   OS.flush();
 666   return Result;
 667 }
 668
 669 // Returns a newly-created ExecutionEngine that reads the bitcode in 'Bitcode'
 670 // lazily.  The associated Module (owned by the ExecutionEngine) is returned in
 671 // M.  Both will be NULL on an error.  Bitcode must live at least as long as the
 672 // ExecutionEngine.
 673 ExecutionEngine *getJITFromBitcode(
 674   LLVMContext &Context, const std::string &Bitcode, Module *&M) {
 675   // c_str() is null-terminated like MemoryBuffer::getMemBuffer requires.
 676   MemoryBuffer *BitcodeBuffer =
 677     MemoryBuffer::getMemBuffer(Bitcode, "Bitcode for test");
 678   std::string errMsg;
 679   M = getLazyBitcodeModule(BitcodeBuffer, Context, &errMsg);
 680   if (M == NULL) {
 681     ADD_FAILURE() << errMsg;
 682     delete BitcodeBuffer;
 683     return NULL;
 684   }
 685   ExecutionEngine *TheJIT = EngineBuilder(M)
 686     .setEngineKind(EngineKind::JIT)
 687     .setErrorStr(&errMsg)
 688     .create();
 689   if (TheJIT == NULL) {
 690     ADD_FAILURE() << errMsg;
 691     delete M;
 692     M = NULL;
 693     return NULL;
 694   }
 695   return TheJIT;
 696 }
 697
 698 TEST(LazyLoadedJITTest, MaterializableAvailableExternallyFunctionIsntCompiled) {
 699   LLVMContext Context;
 700   const std::string Bitcode =
 701     AssembleToBitcode(Context,
 702                       "define available_externally i32 "
 703                       "    @JITTest_AvailableExternallyFunction() { "
 704                       "  ret i32 7 "
 705                       "} "
 706                       " "
 707                       "define i32 @func() { "
 708                       "  %result = tail call i32 "
 709                       "    @JITTest_AvailableExternallyFunction() "
 710                       "  ret i32 %result "
 711                       "} ");
 712   ASSERT_FALSE(Bitcode.empty()) << "Assembling failed";
 713   Module *M;
 714   OwningPtr<ExecutionEngine> TheJIT(getJITFromBitcode(Context, Bitcode, M));
 715   ASSERT_TRUE(TheJIT.get()) << "Failed to create JIT.";
 716   TheJIT->DisableLazyCompilation(true);
 717
 718   Function *funcIR = M->getFunction("func");
 719   Function *availableFunctionIR =
 720     M->getFunction("JITTest_AvailableExternallyFunction");
 721
 722   // Double-check that the available_externally function is still unmaterialized
 723   // when getPointerToFunction needs to find out if it's available_externally.
 724   EXPECT_TRUE(availableFunctionIR->isMaterializable());
 725
 726   int32_t (*func)() = reinterpret_cast<int32_t(*)()>(
 727     (intptr_t)TheJIT->getPointerToFunction(funcIR));
 728   EXPECT_EQ(42, func()) << "func should return 42 from the static version,"
 729                         << " not 7 from the IR version.";
 730 }
 731
 732 TEST(LazyLoadedJITTest, EagerCompiledRecursionThroughGhost) {
 733   LLVMContext Context;
 734   const std::string Bitcode =
 735     AssembleToBitcode(Context,
 736                       "define i32 @recur1(i32 %a) { "
 737                       "  %zero = icmp eq i32 %a, 0 "
 738                       "  br i1 %zero, label %done, label %notdone "
 739                       "done: "
 740                       "  ret i32 3 "
 741                       "notdone: "
 742                       "  %am1 = sub i32 %a, 1 "
 743                       "  %result = call i32 @recur2(i32 %am1) "
 744                       "  ret i32 %result "
 745                       "} "
 746                       " "
 747                       "define i32 @recur2(i32 %b) { "
 748                       "  %result = call i32 @recur1(i32 %b) "
 749                       "  ret i32 %result "
 750                       "} ");
 751   ASSERT_FALSE(Bitcode.empty()) << "Assembling failed";
 752   Module *M;
 753   OwningPtr<ExecutionEngine> TheJIT(getJITFromBitcode(Context, Bitcode, M));
 754   ASSERT_TRUE(TheJIT.get()) << "Failed to create JIT.";
 755   TheJIT->DisableLazyCompilation(true);
 756
 757   Function *recur1IR = M->getFunction("recur1");
 758   Function *recur2IR = M->getFunction("recur2");
 759   EXPECT_TRUE(recur1IR->isMaterializable());
 760   EXPECT_TRUE(recur2IR->isMaterializable());
 761
 762   int32_t (*recur1)(int32_t) = reinterpret_cast<int32_t(*)(int32_t)>(
 763     (intptr_t)TheJIT->getPointerToFunction(recur1IR));
 764   EXPECT_EQ(3, recur1(4));
 765 }
 766
 767 // This code is copied from JITEventListenerTest, but it only runs once for all
 768 // the tests in this directory.  Everything seems fine, but that's strange
 769 // behavior.
 770 class JITEnvironment : public testing::Environment {
 771   virtual void SetUp() {
 772     // Required to create a JIT.
 773     InitializeNativeTarget();
 774   }
 775 };
 776 testing::Environment* const jit_env =
 777   testing::AddGlobalTestEnvironment(new JITEnvironment);
 778
 779 }