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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/Core.h"
20 #include "llvm-c/Linker.h"
21 #include "gtest/gtest.h"
22 
23 using namespace llvm;
24 
25 namespace {
26 
27 class LinkModuleTest : public testing::Test {
28 protected:
SetUp()29   void SetUp() override {
30     M.reset(new Module("MyModule", Ctx));
31     FunctionType *FTy = FunctionType::get(
32         Type::getInt8PtrTy(Ctx), Type::getInt32Ty(Ctx), false /*=isVarArg*/);
33     F = Function::Create(FTy, Function::ExternalLinkage, "ba_func", M.get());
34     F->setCallingConv(CallingConv::C);
35 
36     EntryBB = BasicBlock::Create(Ctx, "entry", F);
37     SwitchCase1BB = BasicBlock::Create(Ctx, "switch.case.1", F);
38     SwitchCase2BB = BasicBlock::Create(Ctx, "switch.case.2", F);
39     ExitBB = BasicBlock::Create(Ctx, "exit", F);
40 
41     AT = ArrayType::get(Type::getInt8PtrTy(Ctx), 3);
42 
43     GV = new GlobalVariable(*M.get(), AT, false /*=isConstant*/,
44                             GlobalValue::InternalLinkage, nullptr,"switch.bas");
45 
46     // Global Initializer
47     std::vector<Constant *> Init;
48     Constant *SwitchCase1BA = BlockAddress::get(SwitchCase1BB);
49     Init.push_back(SwitchCase1BA);
50 
51     Constant *SwitchCase2BA = BlockAddress::get(SwitchCase2BB);
52     Init.push_back(SwitchCase2BA);
53 
54     ConstantInt *One = ConstantInt::get(Type::getInt32Ty(Ctx), 1);
55     Constant *OnePtr = ConstantExpr::getCast(Instruction::IntToPtr, One,
56                                              Type::getInt8PtrTy(Ctx));
57     Init.push_back(OnePtr);
58 
59     GV->setInitializer(ConstantArray::get(AT, Init));
60   }
61 
TearDown()62   void TearDown() override { M.reset(); }
63 
64   LLVMContext Ctx;
65   std::unique_ptr<Module> M;
66   Function *F;
67   ArrayType *AT;
68   GlobalVariable *GV;
69   BasicBlock *EntryBB;
70   BasicBlock *SwitchCase1BB;
71   BasicBlock *SwitchCase2BB;
72   BasicBlock *ExitBB;
73 };
74 
expectNoDiags(const DiagnosticInfo & DI,void * C)75 static void expectNoDiags(const DiagnosticInfo &DI, void *C) {
76   EXPECT_TRUE(false);
77 }
78 
TEST_F(LinkModuleTest,BlockAddress)79 TEST_F(LinkModuleTest, BlockAddress) {
80   IRBuilder<> Builder(EntryBB);
81 
82   std::vector<Value *> GEPIndices;
83   GEPIndices.push_back(ConstantInt::get(Type::getInt32Ty(Ctx), 0));
84   GEPIndices.push_back(&*F->arg_begin());
85 
86   Value *GEP = Builder.CreateGEP(AT, GV, GEPIndices, "switch.gep");
87   Value *Load = Builder.CreateLoad(GEP, "switch.load");
88 
89   Builder.CreateRet(Load);
90 
91   Builder.SetInsertPoint(SwitchCase1BB);
92   Builder.CreateBr(ExitBB);
93 
94   Builder.SetInsertPoint(SwitchCase2BB);
95   Builder.CreateBr(ExitBB);
96 
97   Builder.SetInsertPoint(ExitBB);
98   Builder.CreateRet(ConstantPointerNull::get(Type::getInt8PtrTy(Ctx)));
99 
100   Module *LinkedModule = new Module("MyModuleLinked", Ctx);
101   Ctx.setDiagnosticHandler(expectNoDiags);
102   Linker::linkModules(*LinkedModule, std::move(M));
103 
104   // Check that the global "@switch.bas" is well-formed.
105   const GlobalVariable *LinkedGV = LinkedModule->getNamedGlobal("switch.bas");
106   const Constant *Init = LinkedGV->getInitializer();
107 
108   // @switch.bas = internal global [3 x i8*]
109   //   [i8* blockaddress(@ba_func, %switch.case.1),
110   //    i8* blockaddress(@ba_func, %switch.case.2),
111   //    i8* inttoptr (i32 1 to i8*)]
112 
113   ArrayType *AT = ArrayType::get(Type::getInt8PtrTy(Ctx), 3);
114   EXPECT_EQ(AT, Init->getType());
115 
116   Value *Elem = Init->getOperand(0);
117   ASSERT_TRUE(isa<BlockAddress>(Elem));
118   EXPECT_EQ(cast<BlockAddress>(Elem)->getFunction(),
119             LinkedModule->getFunction("ba_func"));
120   EXPECT_EQ(cast<BlockAddress>(Elem)->getBasicBlock()->getParent(),
121             LinkedModule->getFunction("ba_func"));
122 
123   Elem = Init->getOperand(1);
124   ASSERT_TRUE(isa<BlockAddress>(Elem));
125   EXPECT_EQ(cast<BlockAddress>(Elem)->getFunction(),
126             LinkedModule->getFunction("ba_func"));
127   EXPECT_EQ(cast<BlockAddress>(Elem)->getBasicBlock()->getParent(),
128             LinkedModule->getFunction("ba_func"));
129 
130   delete LinkedModule;
131 }
132 
getExternal(LLVMContext & Ctx,StringRef FuncName)133 static Module *getExternal(LLVMContext &Ctx, StringRef FuncName) {
134   // Create a module with an empty externally-linked function
135   Module *M = new Module("ExternalModule", Ctx);
136   FunctionType *FTy = FunctionType::get(
137       Type::getVoidTy(Ctx), Type::getInt8PtrTy(Ctx), false /*=isVarArgs*/);
138 
139   Function *F =
140       Function::Create(FTy, Function::ExternalLinkage, FuncName, M);
141   F->setCallingConv(CallingConv::C);
142 
143   BasicBlock *BB = BasicBlock::Create(Ctx, "", F);
144   IRBuilder<> Builder(BB);
145   Builder.CreateRetVoid();
146   return M;
147 }
148 
getInternal(LLVMContext & Ctx)149 static Module *getInternal(LLVMContext &Ctx) {
150   Module *InternalM = new Module("InternalModule", Ctx);
151   FunctionType *FTy = FunctionType::get(
152       Type::getVoidTy(Ctx), Type::getInt8PtrTy(Ctx), false /*=isVarArgs*/);
153 
154   Function *F =
155       Function::Create(FTy, Function::InternalLinkage, "bar", InternalM);
156   F->setCallingConv(CallingConv::C);
157 
158   BasicBlock *BB = BasicBlock::Create(Ctx, "", F);
159   IRBuilder<> Builder(BB);
160   Builder.CreateRetVoid();
161 
162   StructType *STy = StructType::create(Ctx, PointerType::get(FTy, 0));
163 
164   GlobalVariable *GV =
165       new GlobalVariable(*InternalM, STy, false /*=isConstant*/,
166                          GlobalValue::InternalLinkage, nullptr, "g");
167 
168   GV->setInitializer(ConstantStruct::get(STy, F));
169   return InternalM;
170 }
171 
TEST_F(LinkModuleTest,EmptyModule)172 TEST_F(LinkModuleTest, EmptyModule) {
173   std::unique_ptr<Module> InternalM(getInternal(Ctx));
174   std::unique_ptr<Module> EmptyM(new Module("EmptyModule1", Ctx));
175   Ctx.setDiagnosticHandler(expectNoDiags);
176   Linker::linkModules(*EmptyM, std::move(InternalM));
177 }
178 
TEST_F(LinkModuleTest,EmptyModule2)179 TEST_F(LinkModuleTest, EmptyModule2) {
180   std::unique_ptr<Module> InternalM(getInternal(Ctx));
181   std::unique_ptr<Module> EmptyM(new Module("EmptyModule1", Ctx));
182   Ctx.setDiagnosticHandler(expectNoDiags);
183   Linker::linkModules(*InternalM, std::move(EmptyM));
184 }
185 
TEST_F(LinkModuleTest,TypeMerge)186 TEST_F(LinkModuleTest, TypeMerge) {
187   LLVMContext C;
188   SMDiagnostic Err;
189 
190   const char *M1Str = "%t = type {i32}\n"
191                       "@t1 = weak global %t zeroinitializer\n";
192   std::unique_ptr<Module> M1 = parseAssemblyString(M1Str, Err, C);
193 
194   const char *M2Str = "%t = type {i32}\n"
195                       "@t2 = weak global %t zeroinitializer\n";
196   std::unique_ptr<Module> M2 = parseAssemblyString(M2Str, Err, C);
197 
198   Ctx.setDiagnosticHandler(expectNoDiags);
199   Linker::linkModules(*M1, std::move(M2));
200 
201   EXPECT_EQ(M1->getNamedGlobal("t1")->getType(),
202             M1->getNamedGlobal("t2")->getType());
203 }
204 
TEST_F(LinkModuleTest,NewCAPISuccess)205 TEST_F(LinkModuleTest, NewCAPISuccess) {
206   std::unique_ptr<Module> DestM(getExternal(Ctx, "foo"));
207   std::unique_ptr<Module> SourceM(getExternal(Ctx, "bar"));
208   LLVMBool Result =
209       LLVMLinkModules2(wrap(DestM.get()), wrap(SourceM.release()));
210   EXPECT_EQ(0, Result);
211   // "bar" is present in destination module
212   EXPECT_NE(nullptr, DestM->getFunction("bar"));
213 }
214 
diagnosticHandler(LLVMDiagnosticInfoRef DI,void * C)215 static void diagnosticHandler(LLVMDiagnosticInfoRef DI, void *C) {
216   auto *Err = reinterpret_cast<std::string *>(C);
217   char *CErr = LLVMGetDiagInfoDescription(DI);
218   *Err = CErr;
219   LLVMDisposeMessage(CErr);
220 }
221 
TEST_F(LinkModuleTest,NewCAPIFailure)222 TEST_F(LinkModuleTest, NewCAPIFailure) {
223   // Symbol clash between two modules
224   LLVMContext Ctx;
225   std::string Err;
226   LLVMContextSetDiagnosticHandler(wrap(&Ctx), diagnosticHandler, &Err);
227 
228   std::unique_ptr<Module> DestM(getExternal(Ctx, "foo"));
229   std::unique_ptr<Module> SourceM(getExternal(Ctx, "foo"));
230   LLVMBool Result =
231       LLVMLinkModules2(wrap(DestM.get()), wrap(SourceM.release()));
232   EXPECT_EQ(1, Result);
233   EXPECT_EQ("Linking globals named 'foo': symbol multiply defined!", Err);
234 }
235 
TEST_F(LinkModuleTest,MoveDistinctMDs)236 TEST_F(LinkModuleTest, MoveDistinctMDs) {
237   LLVMContext C;
238   SMDiagnostic Err;
239 
240   const char *SrcStr = "define void @foo() !attach !0 {\n"
241                        "entry:\n"
242                        "  call void @llvm.md(metadata !1)\n"
243                        "  ret void, !attach !2\n"
244                        "}\n"
245                        "declare void @llvm.md(metadata)\n"
246                        "!named = !{!3, !4}\n"
247                        "!0 = distinct !{}\n"
248                        "!1 = distinct !{}\n"
249                        "!2 = distinct !{}\n"
250                        "!3 = distinct !{}\n"
251                        "!4 = !{!3}\n";
252 
253   std::unique_ptr<Module> Src = parseAssemblyString(SrcStr, Err, C);
254   assert(Src);
255   ASSERT_TRUE(Src.get());
256 
257   // Get the addresses of the Metadata before merging.
258   Function *F = &*Src->begin();
259   ASSERT_EQ("foo", F->getName());
260   BasicBlock *BB = &F->getEntryBlock();
261   auto *CI = cast<CallInst>(&BB->front());
262   auto *RI = cast<ReturnInst>(BB->getTerminator());
263   NamedMDNode *NMD = &*Src->named_metadata_begin();
264 
265   MDNode *M0 = F->getMetadata("attach");
266   MDNode *M1 =
267       cast<MDNode>(cast<MetadataAsValue>(CI->getArgOperand(0))->getMetadata());
268   MDNode *M2 = RI->getMetadata("attach");
269   MDNode *M3 = NMD->getOperand(0);
270   MDNode *M4 = NMD->getOperand(1);
271 
272   // Confirm a few things about the IR.
273   EXPECT_TRUE(M0->isDistinct());
274   EXPECT_TRUE(M1->isDistinct());
275   EXPECT_TRUE(M2->isDistinct());
276   EXPECT_TRUE(M3->isDistinct());
277   EXPECT_TRUE(M4->isUniqued());
278   EXPECT_EQ(M3, M4->getOperand(0));
279 
280   // Link into destination module.
281   auto Dst = llvm::make_unique<Module>("Linked", C);
282   ASSERT_TRUE(Dst.get());
283   Ctx.setDiagnosticHandler(expectNoDiags);
284   Linker::linkModules(*Dst, std::move(Src));
285 
286   // Check that distinct metadata was moved, not cloned.  Even !4, the uniqued
287   // node, should effectively be moved, since its only operand hasn't changed.
288   F = &*Dst->begin();
289   BB = &F->getEntryBlock();
290   CI = cast<CallInst>(&BB->front());
291   RI = cast<ReturnInst>(BB->getTerminator());
292   NMD = &*Dst->named_metadata_begin();
293 
294   EXPECT_EQ(M0, F->getMetadata("attach"));
295   EXPECT_EQ(M1, cast<MetadataAsValue>(CI->getArgOperand(0))->getMetadata());
296   EXPECT_EQ(M2, RI->getMetadata("attach"));
297   EXPECT_EQ(M3, NMD->getOperand(0));
298   EXPECT_EQ(M4, NMD->getOperand(1));
299 
300   // Confirm a few things about the IR.  This shouldn't have changed.
301   EXPECT_TRUE(M0->isDistinct());
302   EXPECT_TRUE(M1->isDistinct());
303   EXPECT_TRUE(M2->isDistinct());
304   EXPECT_TRUE(M3->isDistinct());
305   EXPECT_TRUE(M4->isUniqued());
306   EXPECT_EQ(M3, M4->getOperand(0));
307 }
308 
TEST_F(LinkModuleTest,RemangleIntrinsics)309 TEST_F(LinkModuleTest, RemangleIntrinsics) {
310   LLVMContext C;
311   SMDiagnostic Err;
312 
313   // We load two modules inside the same context C. In both modules there is a
314   // "struct.rtx_def" type. In the module loaded the second (Bar) this type will
315   // be renamed to "struct.rtx_def.0". Check that the intrinsics which have this
316   // type in the signature are properly remangled.
317   const char *FooStr =
318     "%struct.rtx_def = type { i16 }\n"
319     "define void @foo(%struct.rtx_def* %a, i8 %b, i32 %c) {\n"
320     "  call void  @llvm.memset.p0struct.rtx_def.i32(%struct.rtx_def* %a, i8 %b, i32 %c, i32 4, i1 true)\n"
321     "  ret void\n"
322     "}\n"
323     "declare void @llvm.memset.p0struct.rtx_def.i32(%struct.rtx_def*, i8, i32, i32, i1)\n";
324 
325   const char *BarStr =
326     "%struct.rtx_def = type { i16 }\n"
327     "define void @bar(%struct.rtx_def* %a, i8 %b, i32 %c) {\n"
328     "  call void  @llvm.memset.p0struct.rtx_def.i32(%struct.rtx_def* %a, i8 %b, i32 %c, i32 4, i1 true)\n"
329     "  ret void\n"
330     "}\n"
331     "declare void @llvm.memset.p0struct.rtx_def.i32(%struct.rtx_def*, i8, i32, i32, i1)\n";
332 
333   std::unique_ptr<Module> Foo = parseAssemblyString(FooStr, Err, C);
334   assert(Foo);
335   ASSERT_TRUE(Foo.get());
336   // Foo is loaded first, so the type and the intrinsic have theis original
337   // names.
338   ASSERT_TRUE(Foo->getFunction("llvm.memset.p0struct.rtx_def.i32"));
339   ASSERT_FALSE(Foo->getFunction("llvm.memset.p0struct.rtx_def.0.i32"));
340 
341   std::unique_ptr<Module> Bar = parseAssemblyString(BarStr, Err, C);
342   assert(Bar);
343   ASSERT_TRUE(Bar.get());
344   // Bar is loaded after Foo, so the type is renamed to struct.rtx_def.0. Check
345   // that the intrinsic is also renamed.
346   ASSERT_FALSE(Bar->getFunction("llvm.memset.p0struct.rtx_def.i32"));
347   ASSERT_TRUE(Bar->getFunction("llvm.memset.p0struct.rtx_def.0.i32"));
348 
349   // Link two modules together.
350   auto Dst = llvm::make_unique<Module>("Linked", C);
351   ASSERT_TRUE(Dst.get());
352   Ctx.setDiagnosticHandler(expectNoDiags);
353   bool Failed = Linker::linkModules(*Foo, std::move(Bar));
354   ASSERT_FALSE(Failed);
355 
356   // "struct.rtx_def" from Foo and "struct.rtx_def.0" from Bar are isomorphic
357   // types, so they must be uniquified by linker. Check that they use the same
358   // intrinsic definition.
359   Function *F = Foo->getFunction("llvm.memset.p0struct.rtx_def.i32");
360   ASSERT_EQ(F->getNumUses(), (unsigned)2);
361 }
362 
363 } // end anonymous namespace
364