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 "llvm/ExecutionEngine/JIT.h"
11#include "llvm/ADT/SmallPtrSet.h"
12#include "llvm/AsmParser/Parser.h"
13#include "llvm/Bitcode/ReaderWriter.h"
14#include "llvm/ExecutionEngine/JITMemoryManager.h"
15#include "llvm/IR/BasicBlock.h"
16#include "llvm/IR/Constant.h"
17#include "llvm/IR/Constants.h"
18#include "llvm/IR/DerivedTypes.h"
19#include "llvm/IR/Function.h"
20#include "llvm/IR/GlobalValue.h"
21#include "llvm/IR/GlobalVariable.h"
22#include "llvm/IR/IRBuilder.h"
23#include "llvm/IR/LLVMContext.h"
24#include "llvm/IR/Module.h"
25#include "llvm/IR/Type.h"
26#include "llvm/IR/TypeBuilder.h"
27#include "llvm/Support/MemoryBuffer.h"
28#include "llvm/Support/SourceMgr.h"
29#include "llvm/Support/TargetSelect.h"
30#include "gtest/gtest.h"
31#include <vector>
32
33using namespace llvm;
34
35// This variable is intentionally defined differently in the statically-compiled
36// program from the IR input to the JIT to assert that the JIT doesn't use its
37// definition.  Note that this variable must be defined even on platforms where
38// JIT tests are disabled as it is referenced from the .def file.
39extern "C" int32_t JITTest_AvailableExternallyGlobal;
40int32_t JITTest_AvailableExternallyGlobal LLVM_ATTRIBUTE_USED = 42;
41
42// This function is intentionally defined differently in the statically-compiled
43// program from the IR input to the JIT to assert that the JIT doesn't use its
44// definition.  Note that this function must be defined even on platforms where
45// JIT tests are disabled as it is referenced from the .def file.
46extern "C" int32_t JITTest_AvailableExternallyFunction() LLVM_ATTRIBUTE_USED;
47extern "C" int32_t JITTest_AvailableExternallyFunction() {
48  return 42;
49}
50
51namespace {
52
53// Tests on ARM, PowerPC and SystemZ disabled as we're running the old jit
54#if !defined(__arm__) && !defined(__powerpc__) && !defined(__s390__) \
55                      && !defined(__aarch64__)
56
57Function *makeReturnGlobal(std::string Name, GlobalVariable *G, Module *M) {
58  std::vector<Type*> params;
59  FunctionType *FTy = FunctionType::get(G->getType()->getElementType(),
60                                              params, false);
61  Function *F = Function::Create(FTy, GlobalValue::ExternalLinkage, Name, M);
62  BasicBlock *Entry = BasicBlock::Create(M->getContext(), "entry", F);
63  IRBuilder<> builder(Entry);
64  Value *Load = builder.CreateLoad(G);
65  Type *GTy = G->getType()->getElementType();
66  Value *Add = builder.CreateAdd(Load, ConstantInt::get(GTy, 1LL));
67  builder.CreateStore(Add, G);
68  builder.CreateRet(Add);
69  return F;
70}
71
72std::string DumpFunction(const Function *F) {
73  std::string Result;
74  raw_string_ostream(Result) << "" << *F;
75  return Result;
76}
77
78class RecordingJITMemoryManager : public JITMemoryManager {
79  const std::unique_ptr<JITMemoryManager> Base;
80
81public:
82  RecordingJITMemoryManager()
83    : Base(JITMemoryManager::CreateDefaultMemManager()) {
84    stubsAllocated = 0;
85  }
86  virtual void *getPointerToNamedFunction(const std::string &Name,
87                                          bool AbortOnFailure = true) {
88    return Base->getPointerToNamedFunction(Name, AbortOnFailure);
89  }
90
91  virtual void setMemoryWritable() { Base->setMemoryWritable(); }
92  virtual void setMemoryExecutable() { Base->setMemoryExecutable(); }
93  virtual void setPoisonMemory(bool poison) { Base->setPoisonMemory(poison); }
94  virtual void AllocateGOT() { Base->AllocateGOT(); }
95  virtual uint8_t *getGOTBase() const { return Base->getGOTBase(); }
96  struct StartFunctionBodyCall {
97    StartFunctionBodyCall(uint8_t *Result, const Function *F,
98                          uintptr_t ActualSize, uintptr_t ActualSizeResult)
99      : Result(Result), F(F), F_dump(DumpFunction(F)),
100        ActualSize(ActualSize), ActualSizeResult(ActualSizeResult) {}
101    uint8_t *Result;
102    const Function *F;
103    std::string F_dump;
104    uintptr_t ActualSize;
105    uintptr_t ActualSizeResult;
106  };
107  std::vector<StartFunctionBodyCall> startFunctionBodyCalls;
108  virtual uint8_t *startFunctionBody(const Function *F,
109                                     uintptr_t &ActualSize) {
110    uintptr_t InitialActualSize = ActualSize;
111    uint8_t *Result = Base->startFunctionBody(F, ActualSize);
112    startFunctionBodyCalls.push_back(
113      StartFunctionBodyCall(Result, F, InitialActualSize, ActualSize));
114    return Result;
115  }
116  int stubsAllocated;
117  uint8_t *allocateStub(const GlobalValue *F, unsigned StubSize,
118                        unsigned Alignment) override {
119    stubsAllocated++;
120    return Base->allocateStub(F, StubSize, Alignment);
121  }
122  struct EndFunctionBodyCall {
123    EndFunctionBodyCall(const Function *F, uint8_t *FunctionStart,
124                        uint8_t *FunctionEnd)
125      : F(F), F_dump(DumpFunction(F)),
126        FunctionStart(FunctionStart), FunctionEnd(FunctionEnd) {}
127    const Function *F;
128    std::string F_dump;
129    uint8_t *FunctionStart;
130    uint8_t *FunctionEnd;
131  };
132  std::vector<EndFunctionBodyCall> endFunctionBodyCalls;
133  virtual void endFunctionBody(const Function *F, uint8_t *FunctionStart,
134                               uint8_t *FunctionEnd) {
135    endFunctionBodyCalls.push_back(
136      EndFunctionBodyCall(F, FunctionStart, FunctionEnd));
137    Base->endFunctionBody(F, FunctionStart, FunctionEnd);
138  }
139  virtual uint8_t *allocateDataSection(
140    uintptr_t Size, unsigned Alignment, unsigned SectionID,
141    StringRef SectionName, bool IsReadOnly) {
142    return Base->allocateDataSection(
143      Size, Alignment, SectionID, SectionName, IsReadOnly);
144  }
145  virtual uint8_t *allocateCodeSection(
146    uintptr_t Size, unsigned Alignment, unsigned SectionID,
147    StringRef SectionName) {
148    return Base->allocateCodeSection(
149      Size, Alignment, SectionID, SectionName);
150  }
151  virtual bool finalizeMemory(std::string *ErrMsg) { return false; }
152  virtual uint8_t *allocateSpace(intptr_t Size, unsigned Alignment) {
153    return Base->allocateSpace(Size, Alignment);
154  }
155  virtual uint8_t *allocateGlobal(uintptr_t Size, unsigned Alignment) {
156    return Base->allocateGlobal(Size, Alignment);
157  }
158  struct DeallocateFunctionBodyCall {
159    DeallocateFunctionBodyCall(const void *Body) : Body(Body) {}
160    const void *Body;
161  };
162  std::vector<DeallocateFunctionBodyCall> deallocateFunctionBodyCalls;
163  virtual void deallocateFunctionBody(void *Body) {
164    deallocateFunctionBodyCalls.push_back(DeallocateFunctionBodyCall(Body));
165    Base->deallocateFunctionBody(Body);
166  }
167};
168
169bool LoadAssemblyInto(Module *M, const char *assembly) {
170  SMDiagnostic Error;
171  bool success =
172    nullptr != ParseAssemblyString(assembly, M, Error, M->getContext());
173  std::string errMsg;
174  raw_string_ostream os(errMsg);
175  Error.print("", os);
176  EXPECT_TRUE(success) << os.str();
177  return success;
178}
179
180class JITTest : public testing::Test {
181 protected:
182  virtual RecordingJITMemoryManager *createMemoryManager() {
183    return new RecordingJITMemoryManager;
184  }
185
186  virtual void SetUp() {
187    M = new Module("<main>", Context);
188    RJMM = createMemoryManager();
189    RJMM->setPoisonMemory(true);
190    std::string Error;
191    TargetOptions Options;
192    TheJIT.reset(EngineBuilder(M).setEngineKind(EngineKind::JIT)
193                 .setJITMemoryManager(RJMM)
194                 .setErrorStr(&Error)
195                 .setTargetOptions(Options).create());
196    ASSERT_TRUE(TheJIT.get() != nullptr) << Error;
197  }
198
199  void LoadAssembly(const char *assembly) {
200    LoadAssemblyInto(M, assembly);
201  }
202
203  LLVMContext Context;
204  Module *M;  // Owned by ExecutionEngine.
205  RecordingJITMemoryManager *RJMM;
206  std::unique_ptr<ExecutionEngine> TheJIT;
207};
208
209// Regression test for a bug.  The JIT used to allocate globals inside the same
210// memory block used for the function, and when the function code was freed,
211// the global was left in the same place.  This test allocates a function
212// that uses and global, deallocates it, and then makes sure that the global
213// stays alive after that.
214TEST(JIT, GlobalInFunction) {
215  LLVMContext context;
216  Module *M = new Module("<main>", context);
217
218  JITMemoryManager *MemMgr = JITMemoryManager::CreateDefaultMemManager();
219  // Tell the memory manager to poison freed memory so that accessing freed
220  // memory is more easily tested.
221  MemMgr->setPoisonMemory(true);
222  std::string Error;
223  std::unique_ptr<ExecutionEngine> JIT(EngineBuilder(M)
224                                           .setEngineKind(EngineKind::JIT)
225                                           .setErrorStr(&Error)
226                                           .setJITMemoryManager(MemMgr)
227                                           // The next line enables the fix:
228                                           .setAllocateGVsWithCode(false)
229                                           .create());
230  ASSERT_EQ(Error, "");
231
232  // Create a global variable.
233  Type *GTy = Type::getInt32Ty(context);
234  GlobalVariable *G = new GlobalVariable(
235      *M,
236      GTy,
237      false,  // Not constant.
238      GlobalValue::InternalLinkage,
239      Constant::getNullValue(GTy),
240      "myglobal");
241
242  // Make a function that points to a global.
243  Function *F1 = makeReturnGlobal("F1", G, M);
244
245  // Get the pointer to the native code to force it to JIT the function and
246  // allocate space for the global.
247  void (*F1Ptr)() =
248      reinterpret_cast<void(*)()>((intptr_t)JIT->getPointerToFunction(F1));
249
250  // Since F1 was codegen'd, a pointer to G should be available.
251  int32_t *GPtr = (int32_t*)JIT->getPointerToGlobalIfAvailable(G);
252  ASSERT_NE((int32_t*)nullptr, GPtr);
253  EXPECT_EQ(0, *GPtr);
254
255  // F1() should increment G.
256  F1Ptr();
257  EXPECT_EQ(1, *GPtr);
258
259  // Make a second function identical to the first, referring to the same
260  // global.
261  Function *F2 = makeReturnGlobal("F2", G, M);
262  void (*F2Ptr)() =
263      reinterpret_cast<void(*)()>((intptr_t)JIT->getPointerToFunction(F2));
264
265  // F2() should increment G.
266  F2Ptr();
267  EXPECT_EQ(2, *GPtr);
268
269  // Deallocate F1.
270  JIT->freeMachineCodeForFunction(F1);
271
272  // F2() should *still* increment G.
273  F2Ptr();
274  EXPECT_EQ(3, *GPtr);
275}
276
277int PlusOne(int arg) {
278  return arg + 1;
279}
280
281TEST_F(JITTest, FarCallToKnownFunction) {
282  // x86-64 can only make direct calls to functions within 32 bits of
283  // the current PC.  To call anything farther away, we have to load
284  // the address into a register and call through the register.  The
285  // current JIT does this by allocating a stub for any far call.
286  // There was a bug in which the JIT tried to emit a direct call when
287  // the target was already in the JIT's global mappings and lazy
288  // compilation was disabled.
289
290  Function *KnownFunction = Function::Create(
291      TypeBuilder<int(int), false>::get(Context),
292      GlobalValue::ExternalLinkage, "known", M);
293  TheJIT->addGlobalMapping(KnownFunction, (void*)(intptr_t)PlusOne);
294
295  // int test() { return known(7); }
296  Function *TestFunction = Function::Create(
297      TypeBuilder<int(), false>::get(Context),
298      GlobalValue::ExternalLinkage, "test", M);
299  BasicBlock *Entry = BasicBlock::Create(Context, "entry", TestFunction);
300  IRBuilder<> Builder(Entry);
301  Value *result = Builder.CreateCall(
302      KnownFunction,
303      ConstantInt::get(TypeBuilder<int, false>::get(Context), 7));
304  Builder.CreateRet(result);
305
306  TheJIT->DisableLazyCompilation(true);
307  int (*TestFunctionPtr)() = reinterpret_cast<int(*)()>(
308      (intptr_t)TheJIT->getPointerToFunction(TestFunction));
309  // This used to crash in trying to call PlusOne().
310  EXPECT_EQ(8, TestFunctionPtr());
311}
312
313// Test a function C which calls A and B which call each other.
314TEST_F(JITTest, NonLazyCompilationStillNeedsStubs) {
315  TheJIT->DisableLazyCompilation(true);
316
317  FunctionType *Func1Ty =
318      cast<FunctionType>(TypeBuilder<void(void), false>::get(Context));
319  std::vector<Type*> arg_types;
320  arg_types.push_back(Type::getInt1Ty(Context));
321  FunctionType *FuncTy = FunctionType::get(
322      Type::getVoidTy(Context), arg_types, false);
323  Function *Func1 = Function::Create(Func1Ty, Function::ExternalLinkage,
324                                     "func1", M);
325  Function *Func2 = Function::Create(FuncTy, Function::InternalLinkage,
326                                     "func2", M);
327  Function *Func3 = Function::Create(FuncTy, Function::InternalLinkage,
328                                     "func3", M);
329  BasicBlock *Block1 = BasicBlock::Create(Context, "block1", Func1);
330  BasicBlock *Block2 = BasicBlock::Create(Context, "block2", Func2);
331  BasicBlock *True2 = BasicBlock::Create(Context, "cond_true", Func2);
332  BasicBlock *False2 = BasicBlock::Create(Context, "cond_false", Func2);
333  BasicBlock *Block3 = BasicBlock::Create(Context, "block3", Func3);
334  BasicBlock *True3 = BasicBlock::Create(Context, "cond_true", Func3);
335  BasicBlock *False3 = BasicBlock::Create(Context, "cond_false", Func3);
336
337  // Make Func1 call Func2(0) and Func3(0).
338  IRBuilder<> Builder(Block1);
339  Builder.CreateCall(Func2, ConstantInt::getTrue(Context));
340  Builder.CreateCall(Func3, ConstantInt::getTrue(Context));
341  Builder.CreateRetVoid();
342
343  // void Func2(bool b) { if (b) { Func3(false); return; } return; }
344  Builder.SetInsertPoint(Block2);
345  Builder.CreateCondBr(Func2->arg_begin(), True2, False2);
346  Builder.SetInsertPoint(True2);
347  Builder.CreateCall(Func3, ConstantInt::getFalse(Context));
348  Builder.CreateRetVoid();
349  Builder.SetInsertPoint(False2);
350  Builder.CreateRetVoid();
351
352  // void Func3(bool b) { if (b) { Func2(false); return; } return; }
353  Builder.SetInsertPoint(Block3);
354  Builder.CreateCondBr(Func3->arg_begin(), True3, False3);
355  Builder.SetInsertPoint(True3);
356  Builder.CreateCall(Func2, ConstantInt::getFalse(Context));
357  Builder.CreateRetVoid();
358  Builder.SetInsertPoint(False3);
359  Builder.CreateRetVoid();
360
361  // Compile the function to native code
362  void (*F1Ptr)() =
363     reinterpret_cast<void(*)()>((intptr_t)TheJIT->getPointerToFunction(Func1));
364
365  F1Ptr();
366}
367
368// Regression test for PR5162.  This used to trigger an AssertingVH inside the
369// JIT's Function to stub mapping.
370TEST_F(JITTest, NonLazyLeaksNoStubs) {
371  TheJIT->DisableLazyCompilation(true);
372
373  // Create two functions with a single basic block each.
374  FunctionType *FuncTy =
375      cast<FunctionType>(TypeBuilder<int(), false>::get(Context));
376  Function *Func1 = Function::Create(FuncTy, Function::ExternalLinkage,
377                                     "func1", M);
378  Function *Func2 = Function::Create(FuncTy, Function::InternalLinkage,
379                                     "func2", M);
380  BasicBlock *Block1 = BasicBlock::Create(Context, "block1", Func1);
381  BasicBlock *Block2 = BasicBlock::Create(Context, "block2", Func2);
382
383  // The first function calls the second and returns the result
384  IRBuilder<> Builder(Block1);
385  Value *Result = Builder.CreateCall(Func2);
386  Builder.CreateRet(Result);
387
388  // The second function just returns a constant
389  Builder.SetInsertPoint(Block2);
390  Builder.CreateRet(ConstantInt::get(TypeBuilder<int, false>::get(Context),42));
391
392  // Compile the function to native code
393  (void)TheJIT->getPointerToFunction(Func1);
394
395  // Free the JIT state for the functions
396  TheJIT->freeMachineCodeForFunction(Func1);
397  TheJIT->freeMachineCodeForFunction(Func2);
398
399  // Delete the first function (and show that is has no users)
400  EXPECT_EQ(Func1->getNumUses(), 0u);
401  Func1->eraseFromParent();
402
403  // Delete the second function (and show that it has no users - it had one,
404  // func1 but that's gone now)
405  EXPECT_EQ(Func2->getNumUses(), 0u);
406  Func2->eraseFromParent();
407}
408
409TEST_F(JITTest, ModuleDeletion) {
410  TheJIT->DisableLazyCompilation(false);
411  LoadAssembly("define void @main() { "
412               "  call i32 @computeVal() "
413               "  ret void "
414               "} "
415               " "
416               "define internal i32 @computeVal()  { "
417               "  ret i32 0 "
418               "} ");
419  Function *func = M->getFunction("main");
420  TheJIT->getPointerToFunction(func);
421  TheJIT->removeModule(M);
422  delete M;
423
424  SmallPtrSet<const void*, 2> FunctionsDeallocated;
425  for (unsigned i = 0, e = RJMM->deallocateFunctionBodyCalls.size();
426       i != e; ++i) {
427    FunctionsDeallocated.insert(RJMM->deallocateFunctionBodyCalls[i].Body);
428  }
429  for (unsigned i = 0, e = RJMM->startFunctionBodyCalls.size(); i != e; ++i) {
430    EXPECT_TRUE(FunctionsDeallocated.count(
431                  RJMM->startFunctionBodyCalls[i].Result))
432      << "Function leaked: \n" << RJMM->startFunctionBodyCalls[i].F_dump;
433  }
434  EXPECT_EQ(RJMM->startFunctionBodyCalls.size(),
435            RJMM->deallocateFunctionBodyCalls.size());
436}
437
438// ARM, MIPS and PPC still emit stubs for calls since the target may be
439// too far away to call directly.  This #if can probably be removed when
440// http://llvm.org/PR5201 is fixed.
441#if !defined(__arm__) && !defined(__mips__) && \
442    !defined(__powerpc__) && !defined(__ppc__) && !defined(__aarch64__)
443typedef int (*FooPtr) ();
444
445TEST_F(JITTest, NoStubs) {
446  LoadAssembly("define void @bar() {"
447	       "entry: "
448	       "ret void"
449	       "}"
450	       " "
451	       "define i32 @foo() {"
452	       "entry:"
453	       "call void @bar()"
454	       "ret i32 undef"
455	       "}"
456	       " "
457	       "define i32 @main() {"
458	       "entry:"
459	       "%0 = call i32 @foo()"
460	       "call void @bar()"
461	       "ret i32 undef"
462	       "}");
463  Function *foo = M->getFunction("foo");
464  uintptr_t tmp = (uintptr_t)(TheJIT->getPointerToFunction(foo));
465  FooPtr ptr = (FooPtr)(tmp);
466
467  (ptr)();
468
469  // We should now allocate no more stubs, we have the code to foo
470  // and the existing stub for bar.
471  int stubsBefore = RJMM->stubsAllocated;
472  Function *func = M->getFunction("main");
473  TheJIT->getPointerToFunction(func);
474
475  Function *bar = M->getFunction("bar");
476  TheJIT->getPointerToFunction(bar);
477
478  ASSERT_EQ(stubsBefore, RJMM->stubsAllocated);
479}
480#endif  // !ARM && !PPC
481
482TEST_F(JITTest, FunctionPointersOutliveTheirCreator) {
483  TheJIT->DisableLazyCompilation(true);
484  LoadAssembly("define i8()* @get_foo_addr() { "
485               "  ret i8()* @foo "
486               "} "
487               " "
488               "define i8 @foo() { "
489               "  ret i8 42 "
490               "} ");
491  Function *F_get_foo_addr = M->getFunction("get_foo_addr");
492
493  typedef char(*fooT)();
494  fooT (*get_foo_addr)() = reinterpret_cast<fooT(*)()>(
495      (intptr_t)TheJIT->getPointerToFunction(F_get_foo_addr));
496  fooT foo_addr = get_foo_addr();
497
498  // Now free get_foo_addr.  This should not free the machine code for foo or
499  // any call stub returned as foo's canonical address.
500  TheJIT->freeMachineCodeForFunction(F_get_foo_addr);
501
502  // Check by calling the reported address of foo.
503  EXPECT_EQ(42, foo_addr());
504
505  // The reported address should also be the same as the result of a subsequent
506  // getPointerToFunction(foo).
507#if 0
508  // Fails until PR5126 is fixed:
509  Function *F_foo = M->getFunction("foo");
510  fooT foo = reinterpret_cast<fooT>(
511      (intptr_t)TheJIT->getPointerToFunction(F_foo));
512  EXPECT_EQ((intptr_t)foo, (intptr_t)foo_addr);
513#endif
514}
515
516// ARM does not have an implementation of replaceMachineCodeForFunction(),
517// so recompileAndRelinkFunction doesn't work.
518#if !defined(__arm__) && !defined(__aarch64__)
519TEST_F(JITTest, FunctionIsRecompiledAndRelinked) {
520  Function *F = Function::Create(TypeBuilder<int(void), false>::get(Context),
521                                 GlobalValue::ExternalLinkage, "test", M);
522  BasicBlock *Entry = BasicBlock::Create(Context, "entry", F);
523  IRBuilder<> Builder(Entry);
524  Value *Val = ConstantInt::get(TypeBuilder<int, false>::get(Context), 1);
525  Builder.CreateRet(Val);
526
527  TheJIT->DisableLazyCompilation(true);
528  // Compile the function once, and make sure it works.
529  int (*OrigFPtr)() = reinterpret_cast<int(*)()>(
530    (intptr_t)TheJIT->recompileAndRelinkFunction(F));
531  EXPECT_EQ(1, OrigFPtr());
532
533  // Now change the function to return a different value.
534  Entry->eraseFromParent();
535  BasicBlock *NewEntry = BasicBlock::Create(Context, "new_entry", F);
536  Builder.SetInsertPoint(NewEntry);
537  Val = ConstantInt::get(TypeBuilder<int, false>::get(Context), 2);
538  Builder.CreateRet(Val);
539  // Recompile it, which should produce a new function pointer _and_ update the
540  // old one.
541  int (*NewFPtr)() = reinterpret_cast<int(*)()>(
542    (intptr_t)TheJIT->recompileAndRelinkFunction(F));
543
544  EXPECT_EQ(2, NewFPtr())
545    << "The new pointer should call the new version of the function";
546  EXPECT_EQ(2, OrigFPtr())
547    << "The old pointer's target should now jump to the new version";
548}
549#endif  // !defined(__arm__)
550
551TEST_F(JITTest, AvailableExternallyGlobalIsntEmitted) {
552  TheJIT->DisableLazyCompilation(true);
553  LoadAssembly("@JITTest_AvailableExternallyGlobal = "
554               "  available_externally global i32 7 "
555               " "
556               "define i32 @loader() { "
557               "  %result = load i32* @JITTest_AvailableExternallyGlobal "
558               "  ret i32 %result "
559               "} ");
560  Function *loaderIR = M->getFunction("loader");
561
562  int32_t (*loader)() = reinterpret_cast<int32_t(*)()>(
563    (intptr_t)TheJIT->getPointerToFunction(loaderIR));
564  EXPECT_EQ(42, loader()) << "func should return 42 from the external global,"
565                          << " not 7 from the IR version.";
566}
567
568TEST_F(JITTest, AvailableExternallyFunctionIsntCompiled) {
569  TheJIT->DisableLazyCompilation(true);
570  LoadAssembly("define available_externally i32 "
571               "    @JITTest_AvailableExternallyFunction() { "
572               "  ret i32 7 "
573               "} "
574               " "
575               "define i32 @func() { "
576               "  %result = tail call i32 "
577               "    @JITTest_AvailableExternallyFunction() "
578               "  ret i32 %result "
579               "} ");
580  Function *funcIR = M->getFunction("func");
581
582  int32_t (*func)() = reinterpret_cast<int32_t(*)()>(
583    (intptr_t)TheJIT->getPointerToFunction(funcIR));
584  EXPECT_EQ(42, func()) << "func should return 42 from the static version,"
585                        << " not 7 from the IR version.";
586}
587
588TEST_F(JITTest, EscapedLazyStubStillCallable) {
589  TheJIT->DisableLazyCompilation(false);
590  LoadAssembly("define internal i32 @stubbed() { "
591               "  ret i32 42 "
592               "} "
593               " "
594               "define i32()* @get_stub() { "
595               "  ret i32()* @stubbed "
596               "} ");
597  typedef int32_t(*StubTy)();
598
599  // Call get_stub() to get the address of @stubbed without actually JITting it.
600  Function *get_stubIR = M->getFunction("get_stub");
601  StubTy (*get_stub)() = reinterpret_cast<StubTy(*)()>(
602    (intptr_t)TheJIT->getPointerToFunction(get_stubIR));
603  StubTy stubbed = get_stub();
604  // Now get_stubIR is the only reference to stubbed's stub.
605  get_stubIR->eraseFromParent();
606  // Now there are no references inside the JIT, but we've got a pointer outside
607  // it.  The stub should be callable and return the right value.
608  EXPECT_EQ(42, stubbed());
609}
610
611// Converts the LLVM assembly to bitcode and returns it in a std::string.  An
612// empty string indicates an error.
613std::string AssembleToBitcode(LLVMContext &Context, const char *Assembly) {
614  Module TempModule("TempModule", Context);
615  if (!LoadAssemblyInto(&TempModule, Assembly)) {
616    return "";
617  }
618
619  std::string Result;
620  raw_string_ostream OS(Result);
621  WriteBitcodeToFile(&TempModule, OS);
622  OS.flush();
623  return Result;
624}
625
626// Returns a newly-created ExecutionEngine that reads the bitcode in 'Bitcode'
627// lazily.  The associated Module (owned by the ExecutionEngine) is returned in
628// M.  Both will be NULL on an error.  Bitcode must live at least as long as the
629// ExecutionEngine.
630ExecutionEngine *getJITFromBitcode(
631  LLVMContext &Context, const std::string &Bitcode, Module *&M) {
632  // c_str() is null-terminated like MemoryBuffer::getMemBuffer requires.
633  MemoryBuffer *BitcodeBuffer =
634    MemoryBuffer::getMemBuffer(Bitcode, "Bitcode for test");
635  ErrorOr<Module*> ModuleOrErr = getLazyBitcodeModule(BitcodeBuffer, Context);
636  if (std::error_code EC = ModuleOrErr.getError()) {
637    ADD_FAILURE() << EC.message();
638    delete BitcodeBuffer;
639    return nullptr;
640  }
641  M = ModuleOrErr.get();
642  std::string errMsg;
643  ExecutionEngine *TheJIT = EngineBuilder(M)
644    .setEngineKind(EngineKind::JIT)
645    .setErrorStr(&errMsg)
646    .create();
647  if (TheJIT == nullptr) {
648    ADD_FAILURE() << errMsg;
649    delete M;
650    M = nullptr;
651    return nullptr;
652  }
653  return TheJIT;
654}
655
656TEST(LazyLoadedJITTest, MaterializableAvailableExternallyFunctionIsntCompiled) {
657  LLVMContext Context;
658  const std::string Bitcode =
659    AssembleToBitcode(Context,
660                      "define available_externally i32 "
661                      "    @JITTest_AvailableExternallyFunction() { "
662                      "  ret i32 7 "
663                      "} "
664                      " "
665                      "define i32 @func() { "
666                      "  %result = tail call i32 "
667                      "    @JITTest_AvailableExternallyFunction() "
668                      "  ret i32 %result "
669                      "} ");
670  ASSERT_FALSE(Bitcode.empty()) << "Assembling failed";
671  Module *M;
672  std::unique_ptr<ExecutionEngine> TheJIT(
673      getJITFromBitcode(Context, Bitcode, M));
674  ASSERT_TRUE(TheJIT.get()) << "Failed to create JIT.";
675  TheJIT->DisableLazyCompilation(true);
676
677  Function *funcIR = M->getFunction("func");
678  Function *availableFunctionIR =
679    M->getFunction("JITTest_AvailableExternallyFunction");
680
681  // Double-check that the available_externally function is still unmaterialized
682  // when getPointerToFunction needs to find out if it's available_externally.
683  EXPECT_TRUE(availableFunctionIR->isMaterializable());
684
685  int32_t (*func)() = reinterpret_cast<int32_t(*)()>(
686    (intptr_t)TheJIT->getPointerToFunction(funcIR));
687  EXPECT_EQ(42, func()) << "func should return 42 from the static version,"
688                        << " not 7 from the IR version.";
689}
690
691TEST(LazyLoadedJITTest, EagerCompiledRecursionThroughGhost) {
692  LLVMContext Context;
693  const std::string Bitcode =
694    AssembleToBitcode(Context,
695                      "define i32 @recur1(i32 %a) { "
696                      "  %zero = icmp eq i32 %a, 0 "
697                      "  br i1 %zero, label %done, label %notdone "
698                      "done: "
699                      "  ret i32 3 "
700                      "notdone: "
701                      "  %am1 = sub i32 %a, 1 "
702                      "  %result = call i32 @recur2(i32 %am1) "
703                      "  ret i32 %result "
704                      "} "
705                      " "
706                      "define i32 @recur2(i32 %b) { "
707                      "  %result = call i32 @recur1(i32 %b) "
708                      "  ret i32 %result "
709                      "} ");
710  ASSERT_FALSE(Bitcode.empty()) << "Assembling failed";
711  Module *M;
712  std::unique_ptr<ExecutionEngine> TheJIT(
713      getJITFromBitcode(Context, Bitcode, M));
714  ASSERT_TRUE(TheJIT.get()) << "Failed to create JIT.";
715  TheJIT->DisableLazyCompilation(true);
716
717  Function *recur1IR = M->getFunction("recur1");
718  Function *recur2IR = M->getFunction("recur2");
719  EXPECT_TRUE(recur1IR->isMaterializable());
720  EXPECT_TRUE(recur2IR->isMaterializable());
721
722  int32_t (*recur1)(int32_t) = reinterpret_cast<int32_t(*)(int32_t)>(
723    (intptr_t)TheJIT->getPointerToFunction(recur1IR));
724  EXPECT_EQ(3, recur1(4));
725}
726#endif // !defined(__arm__) && !defined(__powerpc__) && !defined(__s390__)
727
728}
729