xref: /llvm-project/llvm/unittests/Linker/LinkModulesTest.cpp (revision 9d2bfc48741a5c0c3a3eb455959a627afcc3b722) 
1 //===- llvm/unittest/Linker/LinkModulesTest.cpp - IRBuilder tests ---------===//
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/ADT/STLExtras.h"
11 #include "llvm/AsmParser/Parser.h"
12 #include "llvm/IR/BasicBlock.h"
13 #include "llvm/IR/DataLayout.h"
14 #include "llvm/IR/Function.h"
15 #include "llvm/IR/IRBuilder.h"
16 #include "llvm/IR/Module.h"
17 #include "llvm/Linker/Linker.h"
18 #include "llvm/Support/SourceMgr.h"
19 #include "llvm-c/Linker.h"
20 #include "gtest/gtest.h"
21 
22 using namespace llvm;
23 
24 namespace {
25 
26 class LinkModuleTest : public testing::Test {
27 protected:
28   void SetUp() override {
29     M.reset(new Module("MyModule", Ctx));
30     FunctionType *FTy = FunctionType::get(
31         Type::getInt8PtrTy(Ctx), Type::getInt32Ty(Ctx), false /*=isVarArg*/);
32     F = Function::Create(FTy, Function::ExternalLinkage, "ba_func", M.get());
33     F->setCallingConv(CallingConv::C);
34 
35     EntryBB = BasicBlock::Create(Ctx, "entry", F);
36     SwitchCase1BB = BasicBlock::Create(Ctx, "switch.case.1", F);
37     SwitchCase2BB = BasicBlock::Create(Ctx, "switch.case.2", F);
38     ExitBB = BasicBlock::Create(Ctx, "exit", F);
39 
40     AT = ArrayType::get(Type::getInt8PtrTy(Ctx), 3);
41 
42     GV = new GlobalVariable(*M.get(), AT, false /*=isConstant*/,
43                             GlobalValue::InternalLinkage, nullptr,"switch.bas");
44 
45     // Global Initializer
46     std::vector<Constant *> Init;
47     Constant *SwitchCase1BA = BlockAddress::get(SwitchCase1BB);
48     Init.push_back(SwitchCase1BA);
49 
50     Constant *SwitchCase2BA = BlockAddress::get(SwitchCase2BB);
51     Init.push_back(SwitchCase2BA);
52 
53     ConstantInt *One = ConstantInt::get(Type::getInt32Ty(Ctx), 1);
54     Constant *OnePtr = ConstantExpr::getCast(Instruction::IntToPtr, One,
55                                              Type::getInt8PtrTy(Ctx));
56     Init.push_back(OnePtr);
57 
58     GV->setInitializer(ConstantArray::get(AT, Init));
59   }
60 
61   void TearDown() override { M.reset(); }
62 
63   LLVMContext Ctx;
64   std::unique_ptr<Module> M;
65   Function *F;
66   ArrayType *AT;
67   GlobalVariable *GV;
68   BasicBlock *EntryBB;
69   BasicBlock *SwitchCase1BB;
70   BasicBlock *SwitchCase2BB;
71   BasicBlock *ExitBB;
72 };
73 
74 static void expectNoDiags(const DiagnosticInfo &DI, void *C) {
75   EXPECT_TRUE(false);
76 }
77 
78 TEST_F(LinkModuleTest, BlockAddress) {
79   IRBuilder<> Builder(EntryBB);
80 
81   std::vector<Value *> GEPIndices;
82   GEPIndices.push_back(ConstantInt::get(Type::getInt32Ty(Ctx), 0));
83   GEPIndices.push_back(&*F->arg_begin());
84 
85   Value *GEP = Builder.CreateGEP(AT, GV, GEPIndices, "switch.gep");
86   Value *Load = Builder.CreateLoad(GEP, "switch.load");
87 
88   Builder.CreateRet(Load);
89 
90   Builder.SetInsertPoint(SwitchCase1BB);
91   Builder.CreateBr(ExitBB);
92 
93   Builder.SetInsertPoint(SwitchCase2BB);
94   Builder.CreateBr(ExitBB);
95 
96   Builder.SetInsertPoint(ExitBB);
97   Builder.CreateRet(ConstantPointerNull::get(Type::getInt8PtrTy(Ctx)));
98 
99   Module *LinkedModule = new Module("MyModuleLinked", Ctx);
100   Ctx.setDiagnosticHandler(expectNoDiags);
101   Linker::linkModules(*LinkedModule, *M);
102 
103   // Delete the original module.
104   M.reset();
105 
106   // Check that the global "@switch.bas" is well-formed.
107   const GlobalVariable *LinkedGV = LinkedModule->getNamedGlobal("switch.bas");
108   const Constant *Init = LinkedGV->getInitializer();
109 
110   // @switch.bas = internal global [3 x i8*]
111   //   [i8* blockaddress(@ba_func, %switch.case.1),
112   //    i8* blockaddress(@ba_func, %switch.case.2),
113   //    i8* inttoptr (i32 1 to i8*)]
114 
115   ArrayType *AT = ArrayType::get(Type::getInt8PtrTy(Ctx), 3);
116   EXPECT_EQ(AT, Init->getType());
117 
118   Value *Elem = Init->getOperand(0);
119   ASSERT_TRUE(isa<BlockAddress>(Elem));
120   EXPECT_EQ(cast<BlockAddress>(Elem)->getFunction(),
121             LinkedModule->getFunction("ba_func"));
122   EXPECT_EQ(cast<BlockAddress>(Elem)->getBasicBlock()->getParent(),
123             LinkedModule->getFunction("ba_func"));
124 
125   Elem = Init->getOperand(1);
126   ASSERT_TRUE(isa<BlockAddress>(Elem));
127   EXPECT_EQ(cast<BlockAddress>(Elem)->getFunction(),
128             LinkedModule->getFunction("ba_func"));
129   EXPECT_EQ(cast<BlockAddress>(Elem)->getBasicBlock()->getParent(),
130             LinkedModule->getFunction("ba_func"));
131 
132   delete LinkedModule;
133 }
134 
135 static Module *getExternal(LLVMContext &Ctx, StringRef FuncName) {
136   // Create a module with an empty externally-linked function
137   Module *M = new Module("ExternalModule", Ctx);
138   FunctionType *FTy = FunctionType::get(
139       Type::getVoidTy(Ctx), Type::getInt8PtrTy(Ctx), false /*=isVarArgs*/);
140 
141   Function *F =
142       Function::Create(FTy, Function::ExternalLinkage, FuncName, M);
143   F->setCallingConv(CallingConv::C);
144 
145   BasicBlock *BB = BasicBlock::Create(Ctx, "", F);
146   IRBuilder<> Builder(BB);
147   Builder.CreateRetVoid();
148   return M;
149 }
150 
151 static Module *getInternal(LLVMContext &Ctx) {
152   Module *InternalM = new Module("InternalModule", Ctx);
153   FunctionType *FTy = FunctionType::get(
154       Type::getVoidTy(Ctx), Type::getInt8PtrTy(Ctx), false /*=isVarArgs*/);
155 
156   Function *F =
157       Function::Create(FTy, Function::InternalLinkage, "bar", InternalM);
158   F->setCallingConv(CallingConv::C);
159 
160   BasicBlock *BB = BasicBlock::Create(Ctx, "", F);
161   IRBuilder<> Builder(BB);
162   Builder.CreateRetVoid();
163 
164   StructType *STy = StructType::create(Ctx, PointerType::get(FTy, 0));
165 
166   GlobalVariable *GV =
167       new GlobalVariable(*InternalM, STy, false /*=isConstant*/,
168                          GlobalValue::InternalLinkage, nullptr, "g");
169 
170   GV->setInitializer(ConstantStruct::get(STy, F));
171   return InternalM;
172 }
173 
174 TEST_F(LinkModuleTest, EmptyModule) {
175   std::unique_ptr<Module> InternalM(getInternal(Ctx));
176   std::unique_ptr<Module> EmptyM(new Module("EmptyModule1", Ctx));
177   Ctx.setDiagnosticHandler(expectNoDiags);
178   Linker::linkModules(*EmptyM, *InternalM);
179 }
180 
181 TEST_F(LinkModuleTest, EmptyModule2) {
182   std::unique_ptr<Module> InternalM(getInternal(Ctx));
183   std::unique_ptr<Module> EmptyM(new Module("EmptyModule1", Ctx));
184   Ctx.setDiagnosticHandler(expectNoDiags);
185   Linker::linkModules(*InternalM, *EmptyM);
186 }
187 
188 TEST_F(LinkModuleTest, TypeMerge) {
189   LLVMContext C;
190   SMDiagnostic Err;
191 
192   const char *M1Str = "%t = type {i32}\n"
193                       "@t1 = weak global %t zeroinitializer\n";
194   std::unique_ptr<Module> M1 = parseAssemblyString(M1Str, Err, C);
195 
196   const char *M2Str = "%t = type {i32}\n"
197                       "@t2 = weak global %t zeroinitializer\n";
198   std::unique_ptr<Module> M2 = parseAssemblyString(M2Str, Err, C);
199 
200   Ctx.setDiagnosticHandler(expectNoDiags);
201   Linker::linkModules(*M1, *M2);
202 
203   EXPECT_EQ(M1->getNamedGlobal("t1")->getType(),
204             M1->getNamedGlobal("t2")->getType());
205 }
206 
207 TEST_F(LinkModuleTest, CAPISuccess) {
208   std::unique_ptr<Module> DestM(getExternal(Ctx, "foo"));
209   std::unique_ptr<Module> SourceM(getExternal(Ctx, "bar"));
210   char *errout = nullptr;
211   LLVMBool result = LLVMLinkModules(wrap(DestM.get()), wrap(SourceM.get()),
212                                     LLVMLinkerDestroySource, &errout);
213   EXPECT_EQ(0, result);
214   EXPECT_EQ(nullptr, errout);
215   // "bar" is present in destination module
216   EXPECT_NE(nullptr, DestM->getFunction("bar"));
217 }
218 
219 TEST_F(LinkModuleTest, CAPIFailure) {
220   // Symbol clash between two modules
221   std::unique_ptr<Module> DestM(getExternal(Ctx, "foo"));
222   std::unique_ptr<Module> SourceM(getExternal(Ctx, "foo"));
223   char *errout = nullptr;
224   LLVMBool result = LLVMLinkModules(wrap(DestM.get()), wrap(SourceM.get()),
225                                     LLVMLinkerDestroySource, &errout);
226   EXPECT_EQ(1, result);
227   EXPECT_STREQ("Linking globals named 'foo': symbol multiply defined!", errout);
228   LLVMDisposeMessage(errout);
229 }
230 
231 TEST_F(LinkModuleTest, MoveDistinctMDs) {
232   LLVMContext C;
233   SMDiagnostic Err;
234 
235   const char *SrcStr = "define void @foo() !attach !0 {\n"
236                        "entry:\n"
237                        "  call void @llvm.md(metadata !1)\n"
238                        "  ret void, !attach !2\n"
239                        "}\n"
240                        "declare void @llvm.md(metadata)\n"
241                        "!named = !{!3, !4}\n"
242                        "!0 = distinct !{}\n"
243                        "!1 = distinct !{}\n"
244                        "!2 = distinct !{}\n"
245                        "!3 = distinct !{}\n"
246                        "!4 = !{!3}\n";
247 
248   std::unique_ptr<Module> Src = parseAssemblyString(SrcStr, Err, C);
249   assert(Src);
250   ASSERT_TRUE(Src.get());
251 
252   // Get the addresses of the Metadata before merging.
253   Function *F = &*Src->begin();
254   ASSERT_EQ("foo", F->getName());
255   BasicBlock *BB = &F->getEntryBlock();
256   auto *CI = cast<CallInst>(&BB->front());
257   auto *RI = cast<ReturnInst>(BB->getTerminator());
258   NamedMDNode *NMD = &*Src->named_metadata_begin();
259 
260   MDNode *M0 = F->getMetadata("attach");
261   MDNode *M1 =
262       cast<MDNode>(cast<MetadataAsValue>(CI->getArgOperand(0))->getMetadata());
263   MDNode *M2 = RI->getMetadata("attach");
264   MDNode *M3 = NMD->getOperand(0);
265   MDNode *M4 = NMD->getOperand(1);
266 
267   // Confirm a few things about the IR.
268   EXPECT_TRUE(M0->isDistinct());
269   EXPECT_TRUE(M1->isDistinct());
270   EXPECT_TRUE(M2->isDistinct());
271   EXPECT_TRUE(M3->isDistinct());
272   EXPECT_TRUE(M4->isUniqued());
273   EXPECT_EQ(M3, M4->getOperand(0));
274 
275   // Link into destination module.
276   auto Dst = llvm::make_unique<Module>("Linked", C);
277   ASSERT_TRUE(Dst.get());
278   Ctx.setDiagnosticHandler(expectNoDiags);
279   Linker::linkModules(*Dst, *Src);
280 
281   // Check that distinct metadata was moved, not cloned.  Even !4, the uniqued
282   // node, should effectively be moved, since its only operand hasn't changed.
283   F = &*Dst->begin();
284   BB = &F->getEntryBlock();
285   CI = cast<CallInst>(&BB->front());
286   RI = cast<ReturnInst>(BB->getTerminator());
287   NMD = &*Dst->named_metadata_begin();
288 
289   EXPECT_EQ(M0, F->getMetadata("attach"));
290   EXPECT_EQ(M1, cast<MetadataAsValue>(CI->getArgOperand(0))->getMetadata());
291   EXPECT_EQ(M2, RI->getMetadata("attach"));
292   EXPECT_EQ(M3, NMD->getOperand(0));
293   EXPECT_EQ(M4, NMD->getOperand(1));
294 
295   // Confirm a few things about the IR.  This shouldn't have changed.
296   EXPECT_TRUE(M0->isDistinct());
297   EXPECT_TRUE(M1->isDistinct());
298   EXPECT_TRUE(M2->isDistinct());
299   EXPECT_TRUE(M3->isDistinct());
300   EXPECT_TRUE(M4->isUniqued());
301   EXPECT_EQ(M3, M4->getOperand(0));
302 }
303 
304 } // end anonymous namespace
305