1//===- MCJITObjectCacheTest.cpp - Unit tests for MCJIT object caching -----===//
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 "MCJITTestBase.h"
11#include "llvm/ADT/SmallVector.h"
12#include "llvm/ADT/StringMap.h"
13#include "llvm/ADT/StringSet.h"
14#include "llvm/ExecutionEngine/MCJIT.h"
15#include "llvm/ExecutionEngine/ObjectCache.h"
16#include "llvm/ExecutionEngine/SectionMemoryManager.h"
17#include "gtest/gtest.h"
18
19using namespace llvm;
20
21namespace {
22
23class TestObjectCache : public ObjectCache {
24public:
25  TestObjectCache() : DuplicateInserted(false) { }
26
27  void notifyObjectCompiled(const Module *M, MemoryBufferRef Obj) override {
28    // If we've seen this module before, note that.
29    const std::string ModuleID = M->getModuleIdentifier();
30    if (ObjMap.find(ModuleID) != ObjMap.end())
31      DuplicateInserted = true;
32    // Store a copy of the buffer in our map.
33    ObjMap[ModuleID] = copyBuffer(Obj);
34  }
35
36  std::unique_ptr<MemoryBuffer> getObject(const Module *M) override {
37    const MemoryBuffer* BufferFound = getObjectInternal(M);
38    ModulesLookedUp.insert(M->getModuleIdentifier());
39    if (!BufferFound)
40      return nullptr;
41    // Our test cache wants to maintain ownership of its object buffers
42    // so we make a copy here for the execution engine.
43    return MemoryBuffer::getMemBufferCopy(BufferFound->getBuffer());
44  }
45
46  // Test-harness-specific functions
47  bool wereDuplicatesInserted() { return DuplicateInserted; }
48
49  bool wasModuleLookedUp(const Module *M) {
50    return ModulesLookedUp.find(M->getModuleIdentifier())
51                                      != ModulesLookedUp.end();
52  }
53
54  const MemoryBuffer* getObjectInternal(const Module* M) {
55    // Look for the module in our map.
56    const std::string ModuleID = M->getModuleIdentifier();
57    StringMap<const MemoryBuffer *>::iterator it = ObjMap.find(ModuleID);
58    if (it == ObjMap.end())
59      return nullptr;
60    return it->second;
61  }
62
63private:
64  MemoryBuffer *copyBuffer(MemoryBufferRef Buf) {
65    // Create a local copy of the buffer.
66    std::unique_ptr<MemoryBuffer> NewBuffer =
67        MemoryBuffer::getMemBufferCopy(Buf.getBuffer());
68    MemoryBuffer *Ret = NewBuffer.get();
69    AllocatedBuffers.push_back(std::move(NewBuffer));
70    return Ret;
71  }
72
73  StringMap<const MemoryBuffer *> ObjMap;
74  StringSet<>                     ModulesLookedUp;
75  SmallVector<std::unique_ptr<MemoryBuffer>, 2> AllocatedBuffers;
76  bool                            DuplicateInserted;
77};
78
79class MCJITObjectCacheTest : public testing::Test, public MCJITTestBase {
80protected:
81  enum {
82    OriginalRC = 6,
83    ReplacementRC = 7
84  };
85
86  void SetUp() override {
87    M.reset(createEmptyModule("<main>"));
88    Main = insertMainFunction(M.get(), OriginalRC);
89  }
90
91  void compileAndRun(int ExpectedRC = OriginalRC) {
92    // This function shouldn't be called until after SetUp.
93    ASSERT_TRUE(bool(TheJIT));
94    ASSERT_TRUE(nullptr != Main);
95
96    // We may be using a null cache, so ensure compilation is valid.
97    TheJIT->finalizeObject();
98    void *vPtr = TheJIT->getPointerToFunction(Main);
99
100    EXPECT_TRUE(nullptr != vPtr)
101      << "Unable to get pointer to main() from JIT";
102
103    int (*FuncPtr)() = (int(*)())(intptr_t)vPtr;
104    int returnCode = FuncPtr();
105    EXPECT_EQ(returnCode, ExpectedRC);
106  }
107
108  Function *Main;
109};
110
111TEST_F(MCJITObjectCacheTest, SetNullObjectCache) {
112  SKIP_UNSUPPORTED_PLATFORM;
113
114  createJIT(std::move(M));
115
116  TheJIT->setObjectCache(nullptr);
117
118  compileAndRun();
119}
120
121TEST_F(MCJITObjectCacheTest, VerifyBasicObjectCaching) {
122  SKIP_UNSUPPORTED_PLATFORM;
123
124  std::unique_ptr<TestObjectCache> Cache(new TestObjectCache);
125
126  // Save a copy of the module pointer before handing it off to MCJIT.
127  const Module * SavedModulePointer = M.get();
128
129  createJIT(std::move(M));
130
131  TheJIT->setObjectCache(Cache.get());
132
133  // Verify that our object cache does not contain the module yet.
134  const MemoryBuffer *ObjBuffer = Cache->getObjectInternal(SavedModulePointer);
135  EXPECT_EQ(nullptr, ObjBuffer);
136
137  compileAndRun();
138
139  // Verify that MCJIT tried to look-up this module in the cache.
140  EXPECT_TRUE(Cache->wasModuleLookedUp(SavedModulePointer));
141
142  // Verify that our object cache now contains the module.
143  ObjBuffer = Cache->getObjectInternal(SavedModulePointer);
144  EXPECT_TRUE(nullptr != ObjBuffer);
145
146  // Verify that the cache was only notified once.
147  EXPECT_FALSE(Cache->wereDuplicatesInserted());
148}
149
150TEST_F(MCJITObjectCacheTest, VerifyLoadFromCache) {
151  SKIP_UNSUPPORTED_PLATFORM;
152
153  std::unique_ptr<TestObjectCache> Cache(new TestObjectCache);
154
155  // Compile this module with an MCJIT engine
156  createJIT(std::move(M));
157  TheJIT->setObjectCache(Cache.get());
158  TheJIT->finalizeObject();
159
160  // Destroy the MCJIT engine we just used
161  TheJIT.reset();
162
163  // Create a new memory manager.
164  MM.reset(new SectionMemoryManager());
165
166  // Create a new module and save it. Use a different return code so we can
167  // tell if MCJIT compiled this module or used the cache.
168  M.reset(createEmptyModule("<main>"));
169  Main = insertMainFunction(M.get(), ReplacementRC);
170  const Module * SecondModulePointer = M.get();
171
172  // Create a new MCJIT instance to load this module then execute it.
173  createJIT(std::move(M));
174  TheJIT->setObjectCache(Cache.get());
175  compileAndRun();
176
177  // Verify that MCJIT tried to look-up this module in the cache.
178  EXPECT_TRUE(Cache->wasModuleLookedUp(SecondModulePointer));
179
180  // Verify that MCJIT didn't try to cache this again.
181  EXPECT_FALSE(Cache->wereDuplicatesInserted());
182}
183
184TEST_F(MCJITObjectCacheTest, VerifyNonLoadFromCache) {
185  SKIP_UNSUPPORTED_PLATFORM;
186
187  std::unique_ptr<TestObjectCache> Cache(new TestObjectCache);
188
189  // Compile this module with an MCJIT engine
190  createJIT(std::move(M));
191  TheJIT->setObjectCache(Cache.get());
192  TheJIT->finalizeObject();
193
194  // Destroy the MCJIT engine we just used
195  TheJIT.reset();
196
197  // Create a new memory manager.
198  MM.reset(new SectionMemoryManager());
199
200  // Create a new module and save it. Use a different return code so we can
201  // tell if MCJIT compiled this module or used the cache. Note that we use
202  // a new module name here so the module shouldn't be found in the cache.
203  M.reset(createEmptyModule("<not-main>"));
204  Main = insertMainFunction(M.get(), ReplacementRC);
205  const Module * SecondModulePointer = M.get();
206
207  // Create a new MCJIT instance to load this module then execute it.
208  createJIT(std::move(M));
209  TheJIT->setObjectCache(Cache.get());
210
211  // Verify that our object cache does not contain the module yet.
212  const MemoryBuffer *ObjBuffer = Cache->getObjectInternal(SecondModulePointer);
213  EXPECT_EQ(nullptr, ObjBuffer);
214
215  // Run the function and look for the replacement return code.
216  compileAndRun(ReplacementRC);
217
218  // Verify that MCJIT tried to look-up this module in the cache.
219  EXPECT_TRUE(Cache->wasModuleLookedUp(SecondModulePointer));
220
221  // Verify that our object cache now contains the module.
222  ObjBuffer = Cache->getObjectInternal(SecondModulePointer);
223  EXPECT_TRUE(nullptr != ObjBuffer);
224
225  // Verify that MCJIT didn't try to cache this again.
226  EXPECT_FALSE(Cache->wereDuplicatesInserted());
227}
228
229} // end anonymous namespace
230