xref: /llvm-project/llvm/unittests/Linker/LinkModulesTest.cpp (revision 14359ef1b6a0610ac91df5f5a91c88a0b51c187c) 
1 //===- llvm/unittest/Linker/LinkModulesTest.cpp - IRBuilder tests ---------===//
2 //
3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4 // See https://llvm.org/LICENSE.txt for license information.
5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6 //
7 //===----------------------------------------------------------------------===//
8 
9 #include "llvm-c/Core.h"
10 #include "llvm-c/Linker.h"
11 #include "llvm/ADT/STLExtras.h"
12 #include "llvm/AsmParser/Parser.h"
13 #include "llvm/IR/BasicBlock.h"
14 #include "llvm/IR/DataLayout.h"
15 #include "llvm/IR/Function.h"
16 #include "llvm/IR/IRBuilder.h"
17 #include "llvm/IR/Module.h"
18 #include "llvm/Linker/Linker.h"
19 #include "llvm/Support/SourceMgr.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(AT->getElementType(), 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.setDiagnosticHandlerCallBack(expectNoDiags);
101   Linker::linkModules(*LinkedModule, std::move(M));
102 
103   // Check that the global "@switch.bas" is well-formed.
104   const GlobalVariable *LinkedGV = LinkedModule->getNamedGlobal("switch.bas");
105   const Constant *Init = LinkedGV->getInitializer();
106 
107   // @switch.bas = internal global [3 x i8*]
108   //   [i8* blockaddress(@ba_func, %switch.case.1),
109   //    i8* blockaddress(@ba_func, %switch.case.2),
110   //    i8* inttoptr (i32 1 to i8*)]
111 
112   ArrayType *AT = ArrayType::get(Type::getInt8PtrTy(Ctx), 3);
113   EXPECT_EQ(AT, Init->getType());
114 
115   Value *Elem = Init->getOperand(0);
116   ASSERT_TRUE(isa<BlockAddress>(Elem));
117   EXPECT_EQ(cast<BlockAddress>(Elem)->getFunction(),
118             LinkedModule->getFunction("ba_func"));
119   EXPECT_EQ(cast<BlockAddress>(Elem)->getBasicBlock()->getParent(),
120             LinkedModule->getFunction("ba_func"));
121 
122   Elem = Init->getOperand(1);
123   ASSERT_TRUE(isa<BlockAddress>(Elem));
124   EXPECT_EQ(cast<BlockAddress>(Elem)->getFunction(),
125             LinkedModule->getFunction("ba_func"));
126   EXPECT_EQ(cast<BlockAddress>(Elem)->getBasicBlock()->getParent(),
127             LinkedModule->getFunction("ba_func"));
128 
129   delete LinkedModule;
130 }
131 
132 static Module *getExternal(LLVMContext &Ctx, StringRef FuncName) {
133   // Create a module with an empty externally-linked function
134   Module *M = new Module("ExternalModule", Ctx);
135   FunctionType *FTy = FunctionType::get(
136       Type::getVoidTy(Ctx), Type::getInt8PtrTy(Ctx), false /*=isVarArgs*/);
137 
138   Function *F =
139       Function::Create(FTy, Function::ExternalLinkage, FuncName, M);
140   F->setCallingConv(CallingConv::C);
141 
142   BasicBlock *BB = BasicBlock::Create(Ctx, "", F);
143   IRBuilder<> Builder(BB);
144   Builder.CreateRetVoid();
145   return M;
146 }
147 
148 static Module *getInternal(LLVMContext &Ctx) {
149   Module *InternalM = new Module("InternalModule", Ctx);
150   FunctionType *FTy = FunctionType::get(
151       Type::getVoidTy(Ctx), Type::getInt8PtrTy(Ctx), false /*=isVarArgs*/);
152 
153   Function *F =
154       Function::Create(FTy, Function::InternalLinkage, "bar", InternalM);
155   F->setCallingConv(CallingConv::C);
156 
157   BasicBlock *BB = BasicBlock::Create(Ctx, "", F);
158   IRBuilder<> Builder(BB);
159   Builder.CreateRetVoid();
160 
161   StructType *STy = StructType::create(Ctx, PointerType::get(FTy, 0));
162 
163   GlobalVariable *GV =
164       new GlobalVariable(*InternalM, STy, false /*=isConstant*/,
165                          GlobalValue::InternalLinkage, nullptr, "g");
166 
167   GV->setInitializer(ConstantStruct::get(STy, F));
168   return InternalM;
169 }
170 
171 TEST_F(LinkModuleTest, EmptyModule) {
172   std::unique_ptr<Module> InternalM(getInternal(Ctx));
173   std::unique_ptr<Module> EmptyM(new Module("EmptyModule1", Ctx));
174   Ctx.setDiagnosticHandlerCallBack(expectNoDiags);
175   Linker::linkModules(*EmptyM, std::move(InternalM));
176 }
177 
178 TEST_F(LinkModuleTest, EmptyModule2) {
179   std::unique_ptr<Module> InternalM(getInternal(Ctx));
180   std::unique_ptr<Module> EmptyM(new Module("EmptyModule1", Ctx));
181   Ctx.setDiagnosticHandlerCallBack(expectNoDiags);
182   Linker::linkModules(*InternalM, std::move(EmptyM));
183 }
184 
185 TEST_F(LinkModuleTest, TypeMerge) {
186   LLVMContext C;
187   SMDiagnostic Err;
188 
189   const char *M1Str = "%t = type {i32}\n"
190                       "@t1 = weak global %t zeroinitializer\n";
191   std::unique_ptr<Module> M1 = parseAssemblyString(M1Str, Err, C);
192 
193   const char *M2Str = "%t = type {i32}\n"
194                       "@t2 = weak global %t zeroinitializer\n";
195   std::unique_ptr<Module> M2 = parseAssemblyString(M2Str, Err, C);
196 
197   Ctx.setDiagnosticHandlerCallBack(expectNoDiags);
198   Linker::linkModules(*M1, std::move(M2));
199 
200   EXPECT_EQ(M1->getNamedGlobal("t1")->getType(),
201             M1->getNamedGlobal("t2")->getType());
202 }
203 
204 TEST_F(LinkModuleTest, NewCAPISuccess) {
205   std::unique_ptr<Module> DestM(getExternal(Ctx, "foo"));
206   std::unique_ptr<Module> SourceM(getExternal(Ctx, "bar"));
207   LLVMBool Result =
208       LLVMLinkModules2(wrap(DestM.get()), wrap(SourceM.release()));
209   EXPECT_EQ(0, Result);
210   // "bar" is present in destination module
211   EXPECT_NE(nullptr, DestM->getFunction("bar"));
212 }
213 
214 static void diagnosticHandler(LLVMDiagnosticInfoRef DI, void *C) {
215   auto *Err = reinterpret_cast<std::string *>(C);
216   char *CErr = LLVMGetDiagInfoDescription(DI);
217   *Err = CErr;
218   LLVMDisposeMessage(CErr);
219 }
220 
221 TEST_F(LinkModuleTest, NewCAPIFailure) {
222   // Symbol clash between two modules
223   LLVMContext Ctx;
224   std::string Err;
225   LLVMContextSetDiagnosticHandler(wrap(&Ctx), diagnosticHandler, &Err);
226 
227   std::unique_ptr<Module> DestM(getExternal(Ctx, "foo"));
228   std::unique_ptr<Module> SourceM(getExternal(Ctx, "foo"));
229   LLVMBool Result =
230       LLVMLinkModules2(wrap(DestM.get()), wrap(SourceM.release()));
231   EXPECT_EQ(1, Result);
232   EXPECT_EQ("Linking globals named 'foo': symbol multiply defined!", Err);
233 }
234 
235 TEST_F(LinkModuleTest, MoveDistinctMDs) {
236   LLVMContext C;
237   SMDiagnostic Err;
238 
239   const char *SrcStr = "define void @foo() !attach !0 {\n"
240                        "entry:\n"
241                        "  call void @llvm.md(metadata !1)\n"
242                        "  ret void, !attach !2\n"
243                        "}\n"
244                        "declare void @llvm.md(metadata)\n"
245                        "!named = !{!3, !4}\n"
246                        "!0 = distinct !{}\n"
247                        "!1 = distinct !{}\n"
248                        "!2 = distinct !{}\n"
249                        "!3 = distinct !{}\n"
250                        "!4 = !{!3}\n";
251 
252   std::unique_ptr<Module> Src = parseAssemblyString(SrcStr, Err, C);
253   assert(Src);
254   ASSERT_TRUE(Src.get());
255 
256   // Get the addresses of the Metadata before merging.
257   Function *F = &*Src->begin();
258   ASSERT_EQ("foo", F->getName());
259   BasicBlock *BB = &F->getEntryBlock();
260   auto *CI = cast<CallInst>(&BB->front());
261   auto *RI = cast<ReturnInst>(BB->getTerminator());
262   NamedMDNode *NMD = &*Src->named_metadata_begin();
263 
264   MDNode *M0 = F->getMetadata("attach");
265   MDNode *M1 =
266       cast<MDNode>(cast<MetadataAsValue>(CI->getArgOperand(0))->getMetadata());
267   MDNode *M2 = RI->getMetadata("attach");
268   MDNode *M3 = NMD->getOperand(0);
269   MDNode *M4 = NMD->getOperand(1);
270 
271   // Confirm a few things about the IR.
272   EXPECT_TRUE(M0->isDistinct());
273   EXPECT_TRUE(M1->isDistinct());
274   EXPECT_TRUE(M2->isDistinct());
275   EXPECT_TRUE(M3->isDistinct());
276   EXPECT_TRUE(M4->isUniqued());
277   EXPECT_EQ(M3, M4->getOperand(0));
278 
279   // Link into destination module.
280   auto Dst = llvm::make_unique<Module>("Linked", C);
281   ASSERT_TRUE(Dst.get());
282   Ctx.setDiagnosticHandlerCallBack(expectNoDiags);
283   Linker::linkModules(*Dst, std::move(Src));
284 
285   // Check that distinct metadata was moved, not cloned.  Even !4, the uniqued
286   // node, should effectively be moved, since its only operand hasn't changed.
287   F = &*Dst->begin();
288   BB = &F->getEntryBlock();
289   CI = cast<CallInst>(&BB->front());
290   RI = cast<ReturnInst>(BB->getTerminator());
291   NMD = &*Dst->named_metadata_begin();
292 
293   EXPECT_EQ(M0, F->getMetadata("attach"));
294   EXPECT_EQ(M1, cast<MetadataAsValue>(CI->getArgOperand(0))->getMetadata());
295   EXPECT_EQ(M2, RI->getMetadata("attach"));
296   EXPECT_EQ(M3, NMD->getOperand(0));
297   EXPECT_EQ(M4, NMD->getOperand(1));
298 
299   // Confirm a few things about the IR.  This shouldn't have changed.
300   EXPECT_TRUE(M0->isDistinct());
301   EXPECT_TRUE(M1->isDistinct());
302   EXPECT_TRUE(M2->isDistinct());
303   EXPECT_TRUE(M3->isDistinct());
304   EXPECT_TRUE(M4->isUniqued());
305   EXPECT_EQ(M3, M4->getOperand(0));
306 }
307 
308 TEST_F(LinkModuleTest, RemangleIntrinsics) {
309   LLVMContext C;
310   SMDiagnostic Err;
311 
312   // We load two modules inside the same context C. In both modules there is a
313   // "struct.rtx_def" type. In the module loaded the second (Bar) this type will
314   // be renamed to "struct.rtx_def.0". Check that the intrinsics which have this
315   // type in the signature are properly remangled.
316   const char *FooStr =
317     "%struct.rtx_def = type { i16 }\n"
318     "define void @foo(%struct.rtx_def* %a, i8 %b, i32 %c) {\n"
319     "  call void  @llvm.memset.p0s_struct.rtx_defs.i32(%struct.rtx_def* %a, i8 %b, i32 %c, i32 4, i1 true)\n"
320     "  ret void\n"
321     "}\n"
322     "declare void @llvm.memset.p0s_struct.rtx_defs.i32(%struct.rtx_def*, i8, i32, i32, i1)\n";
323 
324   const char *BarStr =
325     "%struct.rtx_def = type { i16 }\n"
326     "define void @bar(%struct.rtx_def* %a, i8 %b, i32 %c) {\n"
327     "  call void  @llvm.memset.p0s_struct.rtx_defs.i32(%struct.rtx_def* %a, i8 %b, i32 %c, i32 4, i1 true)\n"
328     "  ret void\n"
329     "}\n"
330     "declare void @llvm.memset.p0s_struct.rtx_defs.i32(%struct.rtx_def*, i8, i32, i32, i1)\n";
331 
332   std::unique_ptr<Module> Foo = parseAssemblyString(FooStr, Err, C);
333   assert(Foo);
334   ASSERT_TRUE(Foo.get());
335   // Foo is loaded first, so the type and the intrinsic have theis original
336   // names.
337   ASSERT_TRUE(Foo->getFunction("llvm.memset.p0s_struct.rtx_defs.i32"));
338   ASSERT_FALSE(Foo->getFunction("llvm.memset.p0s_struct.rtx_defs.0.i32"));
339 
340   std::unique_ptr<Module> Bar = parseAssemblyString(BarStr, Err, C);
341   assert(Bar);
342   ASSERT_TRUE(Bar.get());
343   // Bar is loaded after Foo, so the type is renamed to struct.rtx_def.0. Check
344   // that the intrinsic is also renamed.
345   ASSERT_FALSE(Bar->getFunction("llvm.memset.p0s_struct.rtx_defs.i32"));
346   ASSERT_TRUE(Bar->getFunction("llvm.memset.p0s_struct.rtx_def.0s.i32"));
347 
348   // Link two modules together.
349   auto Dst = llvm::make_unique<Module>("Linked", C);
350   ASSERT_TRUE(Dst.get());
351   Ctx.setDiagnosticHandlerCallBack(expectNoDiags);
352   bool Failed = Linker::linkModules(*Foo, std::move(Bar));
353   ASSERT_FALSE(Failed);
354 
355   // "struct.rtx_def" from Foo and "struct.rtx_def.0" from Bar are isomorphic
356   // types, so they must be uniquified by linker. Check that they use the same
357   // intrinsic definition.
358   Function *F = Foo->getFunction("llvm.memset.p0s_struct.rtx_defs.i32");
359   ASSERT_EQ(F->getNumUses(), (unsigned)2);
360 }
361 
362 } // end anonymous namespace
363