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