llvm/unittests/CodeGen/LexicalScopesTest.cpp

   1 //===----------- llvm/unittest/CodeGen/LexicalScopesTest.cpp --------------===//
   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/CodeGen/LexicalScopes.h"
  10 #include "llvm/CodeGen/MachineBasicBlock.h"
  11 #include "llvm/CodeGen/MachineFunction.h"
  12 #include "llvm/CodeGen/MachineInstr.h"
  13 #include "llvm/CodeGen/MachineMemOperand.h"
  14 #include "llvm/CodeGen/MachineModuleInfo.h"
  15 #include "llvm/CodeGen/TargetFrameLowering.h"
  16 #include "llvm/CodeGen/TargetInstrInfo.h"
  17 #include "llvm/CodeGen/TargetLowering.h"
  18 #include "llvm/CodeGen/TargetSubtargetInfo.h"
  19 #include "llvm/IR/DIBuilder.h"
  20 #include "llvm/IR/DebugInfoMetadata.h"
  21 #include "llvm/IR/IRBuilder.h"
  22 #include "llvm/IR/ModuleSlotTracker.h"
  23 #include "llvm/MC/MCAsmInfo.h"
  24 #include "llvm/MC/MCSymbol.h"
  25 #include "llvm/MC/TargetRegistry.h"
  26 #include "llvm/Support/TargetSelect.h"
  27 #include "llvm/Target/TargetMachine.h"
  28 #include "llvm/Target/TargetOptions.h"
  29
  30 #include "gtest/gtest.h"
  31
  32 using namespace llvm;
  33
  34 namespace {
  35 // Include helper functions to ease the manipulation of MachineFunctions
  36 #include "MFCommon.inc"
  37
  38 class LexicalScopesTest : public testing::Test {
  39 public:
  40   // Boilerplate,
  41   LLVMContext Ctx;
  42   Module Mod;
  43   std::unique_ptr<MachineFunction> MF;
  44   DICompileUnit *OurCU;
  45   DIFile *OurFile;
  46   DISubprogram *OurFunc;
  47   DILexicalBlock *OurBlock, *AnotherBlock;
  48   DISubprogram *ToInlineFunc;
  49   DILexicalBlock *ToInlineBlock;
  50   // DebugLocs that we'll used to create test environments.
  51   DebugLoc OutermostLoc, InBlockLoc, NotNestedBlockLoc, InlinedLoc;
  52
  53   // Test environment blocks -- these form a diamond control flow pattern,
  54   // MBB1 being the entry block, blocks two and three being the branches, and
  55   // block four joining the branches and being an exit block.
  56   MachineBasicBlock *MBB1, *MBB2, *MBB3, *MBB4;
  57
  58   // Some meaningless instructions -- the first is fully meaningless,
  59   // while the second is supposed to impersonate DBG_VALUEs through its
  60   // opcode.
  61   MCInstrDesc BeanInst;
  62   MCInstrDesc DbgValueInst;
  63
  64   LexicalScopesTest() : Ctx(), Mod("beehives", Ctx) {
  65     memset(&BeanInst, 0, sizeof(BeanInst));
  66     BeanInst.Opcode = 1;
  67     BeanInst.Size = 1;
  68
  69     memset(&DbgValueInst, 0, sizeof(DbgValueInst));
  70     DbgValueInst.Opcode = TargetOpcode::DBG_VALUE;
  71     DbgValueInst.Size = 1;
  72
  73     // Boilerplate that creates a MachineFunction and associated blocks.
  74     MF = createMachineFunction(Ctx, Mod);
  75     llvm::Function &F = const_cast<llvm::Function &>(MF->getFunction());
  76     auto BB1 = BasicBlock::Create(Ctx, "a", &F);
  77     auto BB2 = BasicBlock::Create(Ctx, "b", &F);
  78     auto BB3 = BasicBlock::Create(Ctx, "c", &F);
  79     auto BB4 = BasicBlock::Create(Ctx, "d", &F);
  80     IRBuilder<> IRB1(BB1), IRB2(BB2), IRB3(BB3), IRB4(BB4);
  81     IRB1.CreateBr(BB2);
  82     IRB2.CreateBr(BB3);
  83     IRB3.CreateBr(BB4);
  84     IRB4.CreateRetVoid();
  85     MBB1 = MF->CreateMachineBasicBlock(BB1);
  86     MF->insert(MF->end(), MBB1);
  87     MBB2 = MF->CreateMachineBasicBlock(BB2);
  88     MF->insert(MF->end(), MBB2);
  89     MBB3 = MF->CreateMachineBasicBlock(BB3);
  90     MF->insert(MF->end(), MBB3);
  91     MBB4 = MF->CreateMachineBasicBlock(BB4);
  92     MF->insert(MF->end(), MBB4);
  93     MBB1->addSuccessor(MBB2);
  94     MBB1->addSuccessor(MBB3);
  95     MBB2->addSuccessor(MBB4);
  96     MBB3->addSuccessor(MBB4);
  97
  98     // Create metadata: CU, subprogram, some blocks and an inline function
  99     // scope.
 100     DIBuilder DIB(Mod);
 101     OurFile = DIB.createFile("xyzzy.c", "/cave");
 102     OurCU =
 103         DIB.createCompileUnit(dwarf::DW_LANG_C99, OurFile, "nou", false, "", 0);
 104     auto OurSubT = DIB.createSubroutineType(DIB.getOrCreateTypeArray(None));
 105     OurFunc =
 106         DIB.createFunction(OurCU, "bees", "", OurFile, 1, OurSubT, 1,
 107                            DINode::FlagZero, DISubprogram::SPFlagDefinition);
 108     F.setSubprogram(OurFunc);
 109     OurBlock = DIB.createLexicalBlock(OurFunc, OurFile, 2, 3);
 110     AnotherBlock = DIB.createLexicalBlock(OurFunc, OurFile, 2, 6);
 111     ToInlineFunc =
 112         DIB.createFunction(OurFile, "shoes", "", OurFile, 10, OurSubT, 10,
 113                            DINode::FlagZero, DISubprogram::SPFlagDefinition);
 114
 115     // Make some nested scopes.
 116     OutermostLoc = DILocation::get(Ctx, 3, 1, OurFunc);
 117     InBlockLoc = DILocation::get(Ctx, 4, 1, OurBlock);
 118     InlinedLoc = DILocation::get(Ctx, 10, 1, ToInlineFunc, InBlockLoc.get());
 119
 120     // Make a scope that isn't nested within the others.
 121     NotNestedBlockLoc = DILocation::get(Ctx, 4, 1, AnotherBlock);
 122
 123     DIB.finalize();
 124   }
 125 };
 126
 127 // Fill blocks with dummy instructions, test some base lexical scope
 128 // functionaliy.
 129 TEST_F(LexicalScopesTest, FlatLayout) {
 130   BuildMI(*MBB1, MBB1->end(), OutermostLoc, BeanInst);
 131   BuildMI(*MBB2, MBB2->end(), OutermostLoc, BeanInst);
 132   BuildMI(*MBB3, MBB3->end(), OutermostLoc, BeanInst);
 133   BuildMI(*MBB4, MBB4->end(), OutermostLoc, BeanInst);
 134
 135   LexicalScopes LS;
 136   EXPECT_TRUE(LS.empty());
 137   LS.reset();
 138   EXPECT_EQ(LS.getCurrentFunctionScope(), nullptr);
 139
 140   LS.initialize(*MF);
 141   EXPECT_FALSE(LS.empty());
 142   LexicalScope *FuncScope = LS.getCurrentFunctionScope();
 143   EXPECT_EQ(FuncScope->getParent(), nullptr);
 144   EXPECT_EQ(FuncScope->getDesc(), OurFunc);
 145   EXPECT_EQ(FuncScope->getInlinedAt(), nullptr);
 146   EXPECT_EQ(FuncScope->getScopeNode(), OurFunc);
 147   EXPECT_FALSE(FuncScope->isAbstractScope());
 148   EXPECT_EQ(FuncScope->getChildren().size(), 0u);
 149
 150   // There should be one range, covering the whole function. Test that it
 151   // points at the correct instructions.
 152   auto &Ranges = FuncScope->getRanges();
 153   ASSERT_EQ(Ranges.size(), 1u);
 154   EXPECT_EQ(Ranges.front().first, &*MF->begin()->begin());
 155   auto BBIt = MF->end();
 156   BBIt = std::prev(BBIt);
 157   EXPECT_EQ(Ranges.front().second, &*BBIt->begin());
 158
 159   EXPECT_TRUE(FuncScope->dominates(FuncScope));
 160   SmallPtrSet<const MachineBasicBlock *, 4> MBBVec;
 161   LS.getMachineBasicBlocks(OutermostLoc.get(), MBBVec);
 162
 163   EXPECT_EQ(MBBVec.size(), 4u);
 164   // All the blocks should be in that set; the outermost loc should dominate
 165   // them; and no other scope should.
 166   for (auto &MBB : *MF) {
 167     EXPECT_EQ(MBBVec.count(&MBB), 1u);
 168     EXPECT_TRUE(LS.dominates(OutermostLoc.get(), &MBB));
 169     EXPECT_FALSE(LS.dominates(InBlockLoc.get(), &MBB));
 170     EXPECT_FALSE(LS.dominates(InlinedLoc.get(), &MBB));
 171   }
 172 }
 173
 174 // Examine relationship between two nested scopes inside the function, the
 175 // outer function and the lexical block within it.
 176 TEST_F(LexicalScopesTest, BlockScopes) {
 177   BuildMI(*MBB1, MBB1->end(), InBlockLoc, BeanInst);
 178   BuildMI(*MBB2, MBB2->end(), InBlockLoc, BeanInst);
 179   BuildMI(*MBB3, MBB3->end(), InBlockLoc, BeanInst);
 180   BuildMI(*MBB4, MBB4->end(), InBlockLoc, BeanInst);
 181
 182   LexicalScopes LS;
 183   LS.initialize(*MF);
 184   LexicalScope *FuncScope = LS.getCurrentFunctionScope();
 185   EXPECT_EQ(FuncScope->getDesc(), OurFunc);
 186   auto &Children = FuncScope->getChildren();
 187   ASSERT_EQ(Children.size(), 1u);
 188   auto *BlockScope = Children[0];
 189   EXPECT_EQ(LS.findLexicalScope(InBlockLoc.get()), BlockScope);
 190   EXPECT_EQ(BlockScope->getDesc(), InBlockLoc->getScope());
 191   EXPECT_FALSE(BlockScope->isAbstractScope());
 192
 193   EXPECT_TRUE(FuncScope->dominates(BlockScope));
 194   EXPECT_FALSE(BlockScope->dominates(FuncScope));
 195   EXPECT_EQ(FuncScope->getParent(), nullptr);
 196   EXPECT_EQ(BlockScope->getParent(), FuncScope);
 197
 198   SmallPtrSet<const MachineBasicBlock *, 4> MBBVec;
 199   LS.getMachineBasicBlocks(OutermostLoc.get(), MBBVec);
 200
 201   EXPECT_EQ(MBBVec.size(), 4u);
 202   for (auto &MBB : *MF) {
 203     EXPECT_EQ(MBBVec.count(&MBB), 1u);
 204     EXPECT_TRUE(LS.dominates(OutermostLoc.get(), &MBB));
 205     EXPECT_TRUE(LS.dominates(InBlockLoc.get(), &MBB));
 206     EXPECT_FALSE(LS.dominates(InlinedLoc.get(), &MBB));
 207   }
 208 }
 209
 210 // Test inlined scopes functionality and relationship with the outer scopes.
 211 TEST_F(LexicalScopesTest, InlinedScopes) {
 212   BuildMI(*MBB1, MBB1->end(), InlinedLoc, BeanInst);
 213   BuildMI(*MBB2, MBB2->end(), InlinedLoc, BeanInst);
 214   BuildMI(*MBB3, MBB3->end(), InlinedLoc, BeanInst);
 215   BuildMI(*MBB4, MBB4->end(), InlinedLoc, BeanInst);
 216
 217   LexicalScopes LS;
 218   LS.initialize(*MF);
 219   LexicalScope *FuncScope = LS.getCurrentFunctionScope();
 220   auto &Children = FuncScope->getChildren();
 221   ASSERT_EQ(Children.size(), 1u);
 222   auto *BlockScope = Children[0];
 223   auto &BlockChildren = BlockScope->getChildren();
 224   ASSERT_EQ(BlockChildren.size(), 1u);
 225   auto *InlinedScope = BlockChildren[0];
 226
 227   EXPECT_FALSE(InlinedScope->isAbstractScope());
 228   EXPECT_EQ(InlinedScope->getInlinedAt(), InlinedLoc.getInlinedAt());
 229   EXPECT_EQ(InlinedScope->getDesc(), InlinedLoc.getScope());
 230   EXPECT_EQ(InlinedScope->getChildren().size(), 0u);
 231
 232   EXPECT_EQ(FuncScope->getParent(), nullptr);
 233   EXPECT_EQ(BlockScope->getParent(), FuncScope);
 234   EXPECT_EQ(InlinedScope->getParent(), BlockScope);
 235
 236   const auto &AbstractScopes = LS.getAbstractScopesList();
 237   ASSERT_EQ(AbstractScopes.size(), 1u);
 238   const auto &AbstractScope = *AbstractScopes[0];
 239   EXPECT_TRUE(AbstractScope.isAbstractScope());
 240   EXPECT_EQ(AbstractScope.getDesc(), InlinedLoc.getScope());
 241   EXPECT_EQ(AbstractScope.getInlinedAt(), nullptr);
 242   EXPECT_EQ(AbstractScope.getParent(), nullptr);
 243 }
 244
 245 // Test behaviour in a function that has empty DebugLocs.
 246 TEST_F(LexicalScopesTest, FuncWithEmptyGap) {
 247   BuildMI(*MBB1, MBB1->end(), OutermostLoc, BeanInst);
 248   BuildMI(*MBB2, MBB2->end(), DebugLoc(), BeanInst);
 249   BuildMI(*MBB3, MBB3->end(), DebugLoc(), BeanInst);
 250   BuildMI(*MBB4, MBB4->end(), OutermostLoc, BeanInst);
 251
 252   LexicalScopes LS;
 253   LS.initialize(*MF);
 254   LexicalScope *FuncScope = LS.getCurrentFunctionScope();
 255
 256   // A gap in a range that contains no other location, is not actually a
 257   // gap as far as lexical scopes are concerned.
 258   auto &Ranges = FuncScope->getRanges();
 259   ASSERT_EQ(Ranges.size(), 1u);
 260   EXPECT_EQ(Ranges[0].first, &*MF->begin()->begin());
 261   auto BBIt = MF->end();
 262   BBIt = std::prev(BBIt);
 263   EXPECT_EQ(Ranges[0].second, &*BBIt->begin());
 264 }
 265
 266 // Now a function with intervening not-in-scope instructions.
 267 TEST_F(LexicalScopesTest, FuncWithRealGap) {
 268   MachineInstr *FirstI = BuildMI(*MBB1, MBB1->end(), InBlockLoc, BeanInst);
 269   BuildMI(*MBB2, MBB2->end(), OutermostLoc, BeanInst);
 270   BuildMI(*MBB3, MBB3->end(), OutermostLoc, BeanInst);
 271   MachineInstr *LastI = BuildMI(*MBB4, MBB4->end(), InBlockLoc, BeanInst);
 272
 273   LexicalScopes LS;
 274   LS.initialize(*MF);
 275   LexicalScope *BlockScope = LS.findLexicalScope(InBlockLoc.get());
 276   ASSERT_NE(BlockScope, nullptr);
 277
 278   // Within the block scope, there's a gap between the first and last
 279   // block / instruction, where it's only the outermost scope.
 280   auto &Ranges = BlockScope->getRanges();
 281   ASSERT_EQ(Ranges.size(), 2u);
 282   EXPECT_EQ(Ranges[0].first, FirstI);
 283   EXPECT_EQ(Ranges[0].second, FirstI);
 284   EXPECT_EQ(Ranges[1].first, LastI);
 285   EXPECT_EQ(Ranges[1].second, LastI);
 286
 287   // The outer function scope should cover the whole function, including
 288   // blocks the lexicalblock covers.
 289   LexicalScope *FuncScope = LS.getCurrentFunctionScope();
 290   auto &FuncRanges = FuncScope->getRanges();
 291   ASSERT_EQ(FuncRanges.size(), 1u);
 292   EXPECT_NE(FuncRanges[0].first, FuncRanges[0].second);
 293   EXPECT_EQ(FuncRanges[0].first, FirstI);
 294   EXPECT_EQ(FuncRanges[0].second, LastI);
 295 }
 296
 297 // Examine the relationship between two scopes that don't nest (are siblings).
 298 TEST_F(LexicalScopesTest, NotNested) {
 299   MachineInstr *FirstI = BuildMI(*MBB1, MBB1->end(), InBlockLoc, BeanInst);
 300   MachineInstr *SecondI =
 301       BuildMI(*MBB2, MBB2->end(), NotNestedBlockLoc, BeanInst);
 302   MachineInstr *ThirdI =
 303       BuildMI(*MBB3, MBB3->end(), NotNestedBlockLoc, BeanInst);
 304   MachineInstr *FourthI = BuildMI(*MBB4, MBB4->end(), InBlockLoc, BeanInst);
 305
 306   LexicalScopes LS;
 307   LS.initialize(*MF);
 308   LexicalScope *FuncScope = LS.getCurrentFunctionScope();
 309   LexicalScope *BlockScope = LS.findLexicalScope(InBlockLoc.get());
 310   LexicalScope *OtherBlockScope = LS.findLexicalScope(NotNestedBlockLoc.get());
 311   ASSERT_NE(FuncScope, nullptr);
 312   ASSERT_NE(BlockScope, nullptr);
 313   ASSERT_NE(OtherBlockScope, nullptr);
 314
 315   // The function should cover everything; the two blocks are distinct and
 316   // should not.
 317   auto &FuncRanges = FuncScope->getRanges();
 318   ASSERT_EQ(FuncRanges.size(), 1u);
 319   EXPECT_EQ(FuncRanges[0].first, FirstI);
 320   EXPECT_EQ(FuncRanges[0].second, FourthI);
 321
 322   // Two ranges, start and end instructions.
 323   auto &BlockRanges = BlockScope->getRanges();
 324   ASSERT_EQ(BlockRanges.size(), 2u);
 325   EXPECT_EQ(BlockRanges[0].first, FirstI);
 326   EXPECT_EQ(BlockRanges[0].second, FirstI);
 327   EXPECT_EQ(BlockRanges[1].first, FourthI);
 328   EXPECT_EQ(BlockRanges[1].second, FourthI);
 329
 330   // One inner range, covering the two inner blocks.
 331   auto &OtherBlockRanges = OtherBlockScope->getRanges();
 332   ASSERT_EQ(OtherBlockRanges.size(), 1u);
 333   EXPECT_EQ(OtherBlockRanges[0].first, SecondI);
 334   EXPECT_EQ(OtherBlockRanges[0].second, ThirdI);
 335 }
 336
 337 // Test the scope-specific and block-specific dominates methods.
 338 TEST_F(LexicalScopesTest, TestDominates) {
 339   BuildMI(*MBB1, MBB1->end(), InBlockLoc, BeanInst);
 340   BuildMI(*MBB2, MBB2->end(), NotNestedBlockLoc, BeanInst);
 341   BuildMI(*MBB3, MBB3->end(), NotNestedBlockLoc, BeanInst);
 342   BuildMI(*MBB4, MBB4->end(), InBlockLoc, BeanInst);
 343
 344   LexicalScopes LS;
 345   LS.initialize(*MF);
 346   LexicalScope *FuncScope = LS.getCurrentFunctionScope();
 347   LexicalScope *BlockScope = LS.findLexicalScope(InBlockLoc.get());
 348   LexicalScope *OtherBlockScope = LS.findLexicalScope(NotNestedBlockLoc.get());
 349   ASSERT_NE(FuncScope, nullptr);
 350   ASSERT_NE(BlockScope, nullptr);
 351   ASSERT_NE(OtherBlockScope, nullptr);
 352
 353   EXPECT_TRUE(FuncScope->dominates(BlockScope));
 354   EXPECT_TRUE(FuncScope->dominates(OtherBlockScope));
 355   EXPECT_FALSE(BlockScope->dominates(FuncScope));
 356   EXPECT_FALSE(BlockScope->dominates(OtherBlockScope));
 357   EXPECT_FALSE(OtherBlockScope->dominates(FuncScope));
 358   EXPECT_FALSE(OtherBlockScope->dominates(BlockScope));
 359
 360   // Outermost scope dominates everything, as all insts are within it.
 361   EXPECT_TRUE(LS.dominates(OutermostLoc.get(), MBB1));
 362   EXPECT_TRUE(LS.dominates(OutermostLoc.get(), MBB2));
 363   EXPECT_TRUE(LS.dominates(OutermostLoc.get(), MBB3));
 364   EXPECT_TRUE(LS.dominates(OutermostLoc.get(), MBB4));
 365
 366   // One inner block dominates the outer pair of blocks,
 367   EXPECT_TRUE(LS.dominates(InBlockLoc.get(), MBB1));
 368   EXPECT_FALSE(LS.dominates(InBlockLoc.get(), MBB2));
 369   EXPECT_FALSE(LS.dominates(InBlockLoc.get(), MBB3));
 370   EXPECT_TRUE(LS.dominates(InBlockLoc.get(), MBB4));
 371
 372   // While the other dominates the inner two blocks.
 373   EXPECT_FALSE(LS.dominates(NotNestedBlockLoc.get(), MBB1));
 374   EXPECT_TRUE(LS.dominates(NotNestedBlockLoc.get(), MBB2));
 375   EXPECT_TRUE(LS.dominates(NotNestedBlockLoc.get(), MBB3));
 376   EXPECT_FALSE(LS.dominates(NotNestedBlockLoc.get(), MBB4));
 377 }
 378
 379 // Test getMachineBasicBlocks returns all dominated blocks.
 380 TEST_F(LexicalScopesTest, TestGetBlocks) {
 381   BuildMI(*MBB1, MBB1->end(), InBlockLoc, BeanInst);
 382   BuildMI(*MBB2, MBB2->end(), NotNestedBlockLoc, BeanInst);
 383   BuildMI(*MBB3, MBB3->end(), NotNestedBlockLoc, BeanInst);
 384   BuildMI(*MBB4, MBB4->end(), InBlockLoc, BeanInst);
 385
 386   LexicalScopes LS;
 387   LS.initialize(*MF);
 388   LexicalScope *FuncScope = LS.getCurrentFunctionScope();
 389   LexicalScope *BlockScope = LS.findLexicalScope(InBlockLoc.get());
 390   LexicalScope *OtherBlockScope = LS.findLexicalScope(NotNestedBlockLoc.get());
 391   ASSERT_NE(FuncScope, nullptr);
 392   ASSERT_NE(BlockScope, nullptr);
 393   ASSERT_NE(OtherBlockScope, nullptr);
 394
 395   SmallPtrSet<const MachineBasicBlock *, 4> OutermostBlocks, InBlockBlocks,
 396       NotNestedBlockBlocks;
 397   LS.getMachineBasicBlocks(OutermostLoc.get(), OutermostBlocks);
 398   LS.getMachineBasicBlocks(InBlockLoc.get(), InBlockBlocks);
 399   LS.getMachineBasicBlocks(NotNestedBlockLoc.get(), NotNestedBlockBlocks);
 400
 401   EXPECT_EQ(OutermostBlocks.count(MBB1), 1u);
 402   EXPECT_EQ(OutermostBlocks.count(MBB2), 1u);
 403   EXPECT_EQ(OutermostBlocks.count(MBB3), 1u);
 404   EXPECT_EQ(OutermostBlocks.count(MBB4), 1u);
 405
 406   EXPECT_EQ(InBlockBlocks.count(MBB1), 1u);
 407   EXPECT_EQ(InBlockBlocks.count(MBB2), 0u);
 408   EXPECT_EQ(InBlockBlocks.count(MBB3), 0u);
 409   EXPECT_EQ(InBlockBlocks.count(MBB4), 1u);
 410
 411   EXPECT_EQ(NotNestedBlockBlocks.count(MBB1), 0u);
 412   EXPECT_EQ(NotNestedBlockBlocks.count(MBB2), 1u);
 413   EXPECT_EQ(NotNestedBlockBlocks.count(MBB3), 1u);
 414   EXPECT_EQ(NotNestedBlockBlocks.count(MBB4), 0u);
 415 }
 416
 417 TEST_F(LexicalScopesTest, TestMetaInst) {
 418   // Instruction Layout looks like this, where 'F' means funcscope, and
 419   // 'B' blockscope:
 420   // bb1:
 421   //   F: bean
 422   //   B: bean
 423   // bb2:
 424   //   F: bean
 425   //   B: DBG_VALUE
 426   // bb3:
 427   //   F: bean
 428   //   B: DBG_VALUE
 429   // bb4:
 430   //   F: bean
 431   //   B: bean
 432   // The block / 'B' should only dominate bb1 and bb4. DBG_VALUE is a meta
 433   // instruction, and shouldn't contribute to scopes.
 434   BuildMI(*MBB1, MBB1->end(), OutermostLoc, BeanInst);
 435   BuildMI(*MBB1, MBB1->end(), InBlockLoc, BeanInst);
 436   BuildMI(*MBB2, MBB2->end(), OutermostLoc, BeanInst);
 437   BuildMI(*MBB2, MBB2->end(), InBlockLoc, DbgValueInst);
 438   BuildMI(*MBB3, MBB3->end(), OutermostLoc, BeanInst);
 439   BuildMI(*MBB3, MBB3->end(), InBlockLoc, DbgValueInst);
 440   BuildMI(*MBB4, MBB4->end(), OutermostLoc, BeanInst);
 441   BuildMI(*MBB4, MBB4->end(), InBlockLoc, BeanInst);
 442
 443   LexicalScopes LS;
 444   LS.initialize(*MF);
 445   LexicalScope *FuncScope = LS.getCurrentFunctionScope();
 446   LexicalScope *BlockScope = LS.findLexicalScope(InBlockLoc.get());
 447   ASSERT_NE(FuncScope, nullptr);
 448   ASSERT_NE(BlockScope, nullptr);
 449
 450   EXPECT_TRUE(LS.dominates(OutermostLoc.get(), MBB1));
 451   EXPECT_TRUE(LS.dominates(OutermostLoc.get(), MBB2));
 452   EXPECT_TRUE(LS.dominates(OutermostLoc.get(), MBB3));
 453   EXPECT_TRUE(LS.dominates(OutermostLoc.get(), MBB4));
 454   EXPECT_TRUE(LS.dominates(InBlockLoc.get(), MBB1));
 455   EXPECT_FALSE(LS.dominates(InBlockLoc.get(), MBB2));
 456   EXPECT_FALSE(LS.dominates(InBlockLoc.get(), MBB3));
 457   EXPECT_TRUE(LS.dominates(InBlockLoc.get(), MBB4));
 458 }
 459
 460 } // anonymous namespace