unittests/Linker/LinkModulesTest.cpp

   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 = std::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 = std::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