1 //===-- SanitizerCoverage.cpp - coverage instrumentation for sanitizers ---===// 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 // Coverage instrumentation done on LLVM IR level, works with Sanitizers. 10 // 11 //===----------------------------------------------------------------------===// 12 13 #include "llvm/Transforms/Instrumentation/SanitizerCoverage.h" 14 #include "llvm/ADT/ArrayRef.h" 15 #include "llvm/ADT/SmallVector.h" 16 #include "llvm/Analysis/EHPersonalities.h" 17 #include "llvm/Analysis/PostDominators.h" 18 #include "llvm/IR/CFG.h" 19 #include "llvm/IR/CallSite.h" 20 #include "llvm/IR/Constant.h" 21 #include "llvm/IR/DataLayout.h" 22 #include "llvm/IR/DebugInfo.h" 23 #include "llvm/IR/Dominators.h" 24 #include "llvm/IR/Function.h" 25 #include "llvm/IR/GlobalVariable.h" 26 #include "llvm/IR/IRBuilder.h" 27 #include "llvm/IR/InlineAsm.h" 28 #include "llvm/IR/IntrinsicInst.h" 29 #include "llvm/IR/Intrinsics.h" 30 #include "llvm/IR/LLVMContext.h" 31 #include "llvm/IR/MDBuilder.h" 32 #include "llvm/IR/Mangler.h" 33 #include "llvm/IR/Module.h" 34 #include "llvm/IR/Type.h" 35 #include "llvm/InitializePasses.h" 36 #include "llvm/Support/CommandLine.h" 37 #include "llvm/Support/Debug.h" 38 #include "llvm/Support/raw_ostream.h" 39 #include "llvm/Transforms/Instrumentation.h" 40 #include "llvm/Transforms/Utils/BasicBlockUtils.h" 41 #include "llvm/Transforms/Utils/ModuleUtils.h" 42 43 using namespace llvm; 44 45 #define DEBUG_TYPE "sancov" 46 47 static const char *const SanCovTracePCIndirName = 48 "__sanitizer_cov_trace_pc_indir"; 49 static const char *const SanCovTracePCName = "__sanitizer_cov_trace_pc"; 50 static const char *const SanCovTraceCmp1 = "__sanitizer_cov_trace_cmp1"; 51 static const char *const SanCovTraceCmp2 = "__sanitizer_cov_trace_cmp2"; 52 static const char *const SanCovTraceCmp4 = "__sanitizer_cov_trace_cmp4"; 53 static const char *const SanCovTraceCmp8 = "__sanitizer_cov_trace_cmp8"; 54 static const char *const SanCovTraceConstCmp1 = 55 "__sanitizer_cov_trace_const_cmp1"; 56 static const char *const SanCovTraceConstCmp2 = 57 "__sanitizer_cov_trace_const_cmp2"; 58 static const char *const SanCovTraceConstCmp4 = 59 "__sanitizer_cov_trace_const_cmp4"; 60 static const char *const SanCovTraceConstCmp8 = 61 "__sanitizer_cov_trace_const_cmp8"; 62 static const char *const SanCovTraceDiv4 = "__sanitizer_cov_trace_div4"; 63 static const char *const SanCovTraceDiv8 = "__sanitizer_cov_trace_div8"; 64 static const char *const SanCovTraceGep = "__sanitizer_cov_trace_gep"; 65 static const char *const SanCovTraceSwitchName = "__sanitizer_cov_trace_switch"; 66 static const char *const SanCovModuleCtorTracePcGuardName = 67 "sancov.module_ctor_trace_pc_guard"; 68 static const char *const SanCovModuleCtor8bitCountersName = 69 "sancov.module_ctor_8bit_counters"; 70 static const char *const SanCovModuleCtorBoolFlagName = 71 "sancov.module_ctor_bool_flag"; 72 static const uint64_t SanCtorAndDtorPriority = 2; 73 74 static const char *const SanCovTracePCGuardName = 75 "__sanitizer_cov_trace_pc_guard"; 76 static const char *const SanCovTracePCGuardInitName = 77 "__sanitizer_cov_trace_pc_guard_init"; 78 static const char *const SanCov8bitCountersInitName = 79 "__sanitizer_cov_8bit_counters_init"; 80 static const char *const SanCovBoolFlagInitName = 81 "__sanitizer_cov_bool_flag_init"; 82 static const char *const SanCovPCsInitName = "__sanitizer_cov_pcs_init"; 83 84 static const char *const SanCovGuardsSectionName = "sancov_guards"; 85 static const char *const SanCovCountersSectionName = "sancov_cntrs"; 86 static const char *const SanCovBoolFlagSectionName = "sancov_bool_flag"; 87 static const char *const SanCovPCsSectionName = "sancov_pcs"; 88 89 static const char *const SanCovLowestStackName = "__sancov_lowest_stack"; 90 91 static cl::opt<int> ClCoverageLevel( 92 "sanitizer-coverage-level", 93 cl::desc("Sanitizer Coverage. 0: none, 1: entry block, 2: all blocks, " 94 "3: all blocks and critical edges"), 95 cl::Hidden, cl::init(0)); 96 97 static cl::opt<bool> ClTracePC("sanitizer-coverage-trace-pc", 98 cl::desc("Experimental pc tracing"), cl::Hidden, 99 cl::init(false)); 100 101 static cl::opt<bool> ClTracePCGuard("sanitizer-coverage-trace-pc-guard", 102 cl::desc("pc tracing with a guard"), 103 cl::Hidden, cl::init(false)); 104 105 // If true, we create a global variable that contains PCs of all instrumented 106 // BBs, put this global into a named section, and pass this section's bounds 107 // to __sanitizer_cov_pcs_init. 108 // This way the coverage instrumentation does not need to acquire the PCs 109 // at run-time. Works with trace-pc-guard, inline-8bit-counters, and 110 // inline-bool-flag. 111 static cl::opt<bool> ClCreatePCTable("sanitizer-coverage-pc-table", 112 cl::desc("create a static PC table"), 113 cl::Hidden, cl::init(false)); 114 115 static cl::opt<bool> 116 ClInline8bitCounters("sanitizer-coverage-inline-8bit-counters", 117 cl::desc("increments 8-bit counter for every edge"), 118 cl::Hidden, cl::init(false)); 119 120 static cl::opt<bool> 121 ClInlineBoolFlag("sanitizer-coverage-inline-bool-flag", 122 cl::desc("sets a boolean flag for every edge"), cl::Hidden, 123 cl::init(false)); 124 125 static cl::opt<bool> 126 ClCMPTracing("sanitizer-coverage-trace-compares", 127 cl::desc("Tracing of CMP and similar instructions"), 128 cl::Hidden, cl::init(false)); 129 130 static cl::opt<bool> ClDIVTracing("sanitizer-coverage-trace-divs", 131 cl::desc("Tracing of DIV instructions"), 132 cl::Hidden, cl::init(false)); 133 134 static cl::opt<bool> ClGEPTracing("sanitizer-coverage-trace-geps", 135 cl::desc("Tracing of GEP instructions"), 136 cl::Hidden, cl::init(false)); 137 138 static cl::opt<bool> 139 ClPruneBlocks("sanitizer-coverage-prune-blocks", 140 cl::desc("Reduce the number of instrumented blocks"), 141 cl::Hidden, cl::init(true)); 142 143 static cl::opt<bool> ClStackDepth("sanitizer-coverage-stack-depth", 144 cl::desc("max stack depth tracing"), 145 cl::Hidden, cl::init(false)); 146 147 namespace { 148 149 SanitizerCoverageOptions getOptions(int LegacyCoverageLevel) { 150 SanitizerCoverageOptions Res; 151 switch (LegacyCoverageLevel) { 152 case 0: 153 Res.CoverageType = SanitizerCoverageOptions::SCK_None; 154 break; 155 case 1: 156 Res.CoverageType = SanitizerCoverageOptions::SCK_Function; 157 break; 158 case 2: 159 Res.CoverageType = SanitizerCoverageOptions::SCK_BB; 160 break; 161 case 3: 162 Res.CoverageType = SanitizerCoverageOptions::SCK_Edge; 163 break; 164 case 4: 165 Res.CoverageType = SanitizerCoverageOptions::SCK_Edge; 166 Res.IndirectCalls = true; 167 break; 168 } 169 return Res; 170 } 171 172 SanitizerCoverageOptions OverrideFromCL(SanitizerCoverageOptions Options) { 173 // Sets CoverageType and IndirectCalls. 174 SanitizerCoverageOptions CLOpts = getOptions(ClCoverageLevel); 175 Options.CoverageType = std::max(Options.CoverageType, CLOpts.CoverageType); 176 Options.IndirectCalls |= CLOpts.IndirectCalls; 177 Options.TraceCmp |= ClCMPTracing; 178 Options.TraceDiv |= ClDIVTracing; 179 Options.TraceGep |= ClGEPTracing; 180 Options.TracePC |= ClTracePC; 181 Options.TracePCGuard |= ClTracePCGuard; 182 Options.Inline8bitCounters |= ClInline8bitCounters; 183 Options.InlineBoolFlag |= ClInlineBoolFlag; 184 Options.PCTable |= ClCreatePCTable; 185 Options.NoPrune |= !ClPruneBlocks; 186 Options.StackDepth |= ClStackDepth; 187 if (!Options.TracePCGuard && !Options.TracePC && 188 !Options.Inline8bitCounters && !Options.StackDepth && 189 !Options.InlineBoolFlag) 190 Options.TracePCGuard = true; // TracePCGuard is default. 191 return Options; 192 } 193 194 using DomTreeCallback = function_ref<const DominatorTree *(Function &F)>; 195 using PostDomTreeCallback = 196 function_ref<const PostDominatorTree *(Function &F)>; 197 198 class ModuleSanitizerCoverage { 199 public: 200 ModuleSanitizerCoverage( 201 const SanitizerCoverageOptions &Options = SanitizerCoverageOptions()) 202 : Options(OverrideFromCL(Options)) {} 203 bool instrumentModule(Module &M, DomTreeCallback DTCallback, 204 PostDomTreeCallback PDTCallback); 205 206 private: 207 void instrumentFunction(Function &F, DomTreeCallback DTCallback, 208 PostDomTreeCallback PDTCallback); 209 void InjectCoverageForIndirectCalls(Function &F, 210 ArrayRef<Instruction *> IndirCalls); 211 void InjectTraceForCmp(Function &F, ArrayRef<Instruction *> CmpTraceTargets); 212 void InjectTraceForDiv(Function &F, 213 ArrayRef<BinaryOperator *> DivTraceTargets); 214 void InjectTraceForGep(Function &F, 215 ArrayRef<GetElementPtrInst *> GepTraceTargets); 216 void InjectTraceForSwitch(Function &F, 217 ArrayRef<Instruction *> SwitchTraceTargets); 218 bool InjectCoverage(Function &F, ArrayRef<BasicBlock *> AllBlocks, 219 bool IsLeafFunc = true); 220 GlobalVariable *CreateFunctionLocalArrayInSection(size_t NumElements, 221 Function &F, Type *Ty, 222 const char *Section); 223 GlobalVariable *CreatePCArray(Function &F, ArrayRef<BasicBlock *> AllBlocks); 224 void CreateFunctionLocalArrays(Function &F, ArrayRef<BasicBlock *> AllBlocks); 225 void InjectCoverageAtBlock(Function &F, BasicBlock &BB, size_t Idx, 226 bool IsLeafFunc = true); 227 Function *CreateInitCallsForSections(Module &M, const char *CtorName, 228 const char *InitFunctionName, Type *Ty, 229 const char *Section); 230 std::pair<Value *, Value *> CreateSecStartEnd(Module &M, const char *Section, 231 Type *Ty); 232 233 void SetNoSanitizeMetadata(Instruction *I) { 234 I->setMetadata(I->getModule()->getMDKindID("nosanitize"), 235 MDNode::get(*C, None)); 236 } 237 238 std::string getSectionName(const std::string &Section) const; 239 std::string getSectionStart(const std::string &Section) const; 240 std::string getSectionEnd(const std::string &Section) const; 241 FunctionCallee SanCovTracePCIndir; 242 FunctionCallee SanCovTracePC, SanCovTracePCGuard; 243 FunctionCallee SanCovTraceCmpFunction[4]; 244 FunctionCallee SanCovTraceConstCmpFunction[4]; 245 FunctionCallee SanCovTraceDivFunction[2]; 246 FunctionCallee SanCovTraceGepFunction; 247 FunctionCallee SanCovTraceSwitchFunction; 248 GlobalVariable *SanCovLowestStack; 249 InlineAsm *EmptyAsm; 250 Type *IntptrTy, *IntptrPtrTy, *Int64Ty, *Int64PtrTy, *Int32Ty, *Int32PtrTy, 251 *Int16Ty, *Int8Ty, *Int8PtrTy, *Int1Ty, *Int1PtrTy; 252 Module *CurModule; 253 std::string CurModuleUniqueId; 254 Triple TargetTriple; 255 LLVMContext *C; 256 const DataLayout *DL; 257 258 GlobalVariable *FunctionGuardArray; // for trace-pc-guard. 259 GlobalVariable *Function8bitCounterArray; // for inline-8bit-counters. 260 GlobalVariable *FunctionBoolArray; // for inline-bool-flag. 261 GlobalVariable *FunctionPCsArray; // for pc-table. 262 SmallVector<GlobalValue *, 20> GlobalsToAppendToUsed; 263 SmallVector<GlobalValue *, 20> GlobalsToAppendToCompilerUsed; 264 265 SanitizerCoverageOptions Options; 266 }; 267 268 class ModuleSanitizerCoverageLegacyPass : public ModulePass { 269 public: 270 ModuleSanitizerCoverageLegacyPass( 271 const SanitizerCoverageOptions &Options = SanitizerCoverageOptions()) 272 : ModulePass(ID), Options(Options) { 273 initializeModuleSanitizerCoverageLegacyPassPass( 274 *PassRegistry::getPassRegistry()); 275 } 276 bool runOnModule(Module &M) override { 277 ModuleSanitizerCoverage ModuleSancov(Options); 278 auto DTCallback = [this](Function &F) -> const DominatorTree * { 279 return &this->getAnalysis<DominatorTreeWrapperPass>(F).getDomTree(); 280 }; 281 auto PDTCallback = [this](Function &F) -> const PostDominatorTree * { 282 return &this->getAnalysis<PostDominatorTreeWrapperPass>(F) 283 .getPostDomTree(); 284 }; 285 return ModuleSancov.instrumentModule(M, DTCallback, PDTCallback); 286 } 287 288 static char ID; // Pass identification, replacement for typeid 289 StringRef getPassName() const override { return "ModuleSanitizerCoverage"; } 290 291 void getAnalysisUsage(AnalysisUsage &AU) const override { 292 AU.addRequired<DominatorTreeWrapperPass>(); 293 AU.addRequired<PostDominatorTreeWrapperPass>(); 294 } 295 296 private: 297 SanitizerCoverageOptions Options; 298 }; 299 300 } // namespace 301 302 PreservedAnalyses ModuleSanitizerCoveragePass::run(Module &M, 303 ModuleAnalysisManager &MAM) { 304 ModuleSanitizerCoverage ModuleSancov(Options); 305 auto &FAM = MAM.getResult<FunctionAnalysisManagerModuleProxy>(M).getManager(); 306 auto DTCallback = [&FAM](Function &F) -> const DominatorTree * { 307 return &FAM.getResult<DominatorTreeAnalysis>(F); 308 }; 309 auto PDTCallback = [&FAM](Function &F) -> const PostDominatorTree * { 310 return &FAM.getResult<PostDominatorTreeAnalysis>(F); 311 }; 312 if (ModuleSancov.instrumentModule(M, DTCallback, PDTCallback)) 313 return PreservedAnalyses::none(); 314 return PreservedAnalyses::all(); 315 } 316 317 std::pair<Value *, Value *> 318 ModuleSanitizerCoverage::CreateSecStartEnd(Module &M, const char *Section, 319 Type *Ty) { 320 GlobalVariable *SecStart = 321 new GlobalVariable(M, Ty, false, GlobalVariable::ExternalLinkage, nullptr, 322 getSectionStart(Section)); 323 SecStart->setVisibility(GlobalValue::HiddenVisibility); 324 GlobalVariable *SecEnd = 325 new GlobalVariable(M, Ty, false, GlobalVariable::ExternalLinkage, 326 nullptr, getSectionEnd(Section)); 327 SecEnd->setVisibility(GlobalValue::HiddenVisibility); 328 IRBuilder<> IRB(M.getContext()); 329 Value *SecEndPtr = IRB.CreatePointerCast(SecEnd, Ty); 330 if (!TargetTriple.isOSBinFormatCOFF()) 331 return std::make_pair(IRB.CreatePointerCast(SecStart, Ty), SecEndPtr); 332 333 // Account for the fact that on windows-msvc __start_* symbols actually 334 // point to a uint64_t before the start of the array. 335 auto SecStartI8Ptr = IRB.CreatePointerCast(SecStart, Int8PtrTy); 336 auto GEP = IRB.CreateGEP(Int8Ty, SecStartI8Ptr, 337 ConstantInt::get(IntptrTy, sizeof(uint64_t))); 338 return std::make_pair(IRB.CreatePointerCast(GEP, Ty), SecEndPtr); 339 } 340 341 Function *ModuleSanitizerCoverage::CreateInitCallsForSections( 342 Module &M, const char *CtorName, const char *InitFunctionName, Type *Ty, 343 const char *Section) { 344 auto SecStartEnd = CreateSecStartEnd(M, Section, Ty); 345 auto SecStart = SecStartEnd.first; 346 auto SecEnd = SecStartEnd.second; 347 Function *CtorFunc; 348 std::tie(CtorFunc, std::ignore) = createSanitizerCtorAndInitFunctions( 349 M, CtorName, InitFunctionName, {Ty, Ty}, {SecStart, SecEnd}); 350 assert(CtorFunc->getName() == CtorName); 351 352 if (TargetTriple.supportsCOMDAT()) { 353 // Use comdat to dedup CtorFunc. 354 CtorFunc->setComdat(M.getOrInsertComdat(CtorName)); 355 appendToGlobalCtors(M, CtorFunc, SanCtorAndDtorPriority, CtorFunc); 356 } else { 357 appendToGlobalCtors(M, CtorFunc, SanCtorAndDtorPriority); 358 } 359 360 if (TargetTriple.isOSBinFormatCOFF()) { 361 // In COFF files, if the contructors are set as COMDAT (they are because 362 // COFF supports COMDAT) and the linker flag /OPT:REF (strip unreferenced 363 // functions and data) is used, the constructors get stripped. To prevent 364 // this, give the constructors weak ODR linkage and ensure the linker knows 365 // to include the sancov constructor. This way the linker can deduplicate 366 // the constructors but always leave one copy. 367 CtorFunc->setLinkage(GlobalValue::WeakODRLinkage); 368 appendToUsed(M, CtorFunc); 369 } 370 return CtorFunc; 371 } 372 373 bool ModuleSanitizerCoverage::instrumentModule( 374 Module &M, DomTreeCallback DTCallback, PostDomTreeCallback PDTCallback) { 375 if (Options.CoverageType == SanitizerCoverageOptions::SCK_None) 376 return false; 377 C = &(M.getContext()); 378 DL = &M.getDataLayout(); 379 CurModule = &M; 380 CurModuleUniqueId = getUniqueModuleId(CurModule); 381 TargetTriple = Triple(M.getTargetTriple()); 382 FunctionGuardArray = nullptr; 383 Function8bitCounterArray = nullptr; 384 FunctionBoolArray = nullptr; 385 FunctionPCsArray = nullptr; 386 IntptrTy = Type::getIntNTy(*C, DL->getPointerSizeInBits()); 387 IntptrPtrTy = PointerType::getUnqual(IntptrTy); 388 Type *VoidTy = Type::getVoidTy(*C); 389 IRBuilder<> IRB(*C); 390 Int64PtrTy = PointerType::getUnqual(IRB.getInt64Ty()); 391 Int32PtrTy = PointerType::getUnqual(IRB.getInt32Ty()); 392 Int8PtrTy = PointerType::getUnqual(IRB.getInt8Ty()); 393 Int1PtrTy = PointerType::getUnqual(IRB.getInt1Ty()); 394 Int64Ty = IRB.getInt64Ty(); 395 Int32Ty = IRB.getInt32Ty(); 396 Int16Ty = IRB.getInt16Ty(); 397 Int8Ty = IRB.getInt8Ty(); 398 Int1Ty = IRB.getInt1Ty(); 399 400 SanCovTracePCIndir = 401 M.getOrInsertFunction(SanCovTracePCIndirName, VoidTy, IntptrTy); 402 // Make sure smaller parameters are zero-extended to i64 as required by the 403 // x86_64 ABI. 404 AttributeList SanCovTraceCmpZeroExtAL; 405 if (TargetTriple.getArch() == Triple::x86_64) { 406 SanCovTraceCmpZeroExtAL = 407 SanCovTraceCmpZeroExtAL.addParamAttribute(*C, 0, Attribute::ZExt); 408 SanCovTraceCmpZeroExtAL = 409 SanCovTraceCmpZeroExtAL.addParamAttribute(*C, 1, Attribute::ZExt); 410 } 411 412 SanCovTraceCmpFunction[0] = 413 M.getOrInsertFunction(SanCovTraceCmp1, SanCovTraceCmpZeroExtAL, VoidTy, 414 IRB.getInt8Ty(), IRB.getInt8Ty()); 415 SanCovTraceCmpFunction[1] = 416 M.getOrInsertFunction(SanCovTraceCmp2, SanCovTraceCmpZeroExtAL, VoidTy, 417 IRB.getInt16Ty(), IRB.getInt16Ty()); 418 SanCovTraceCmpFunction[2] = 419 M.getOrInsertFunction(SanCovTraceCmp4, SanCovTraceCmpZeroExtAL, VoidTy, 420 IRB.getInt32Ty(), IRB.getInt32Ty()); 421 SanCovTraceCmpFunction[3] = 422 M.getOrInsertFunction(SanCovTraceCmp8, VoidTy, Int64Ty, Int64Ty); 423 424 SanCovTraceConstCmpFunction[0] = M.getOrInsertFunction( 425 SanCovTraceConstCmp1, SanCovTraceCmpZeroExtAL, VoidTy, Int8Ty, Int8Ty); 426 SanCovTraceConstCmpFunction[1] = M.getOrInsertFunction( 427 SanCovTraceConstCmp2, SanCovTraceCmpZeroExtAL, VoidTy, Int16Ty, Int16Ty); 428 SanCovTraceConstCmpFunction[2] = M.getOrInsertFunction( 429 SanCovTraceConstCmp4, SanCovTraceCmpZeroExtAL, VoidTy, Int32Ty, Int32Ty); 430 SanCovTraceConstCmpFunction[3] = 431 M.getOrInsertFunction(SanCovTraceConstCmp8, VoidTy, Int64Ty, Int64Ty); 432 433 { 434 AttributeList AL; 435 if (TargetTriple.getArch() == Triple::x86_64) 436 AL = AL.addParamAttribute(*C, 0, Attribute::ZExt); 437 SanCovTraceDivFunction[0] = 438 M.getOrInsertFunction(SanCovTraceDiv4, AL, VoidTy, IRB.getInt32Ty()); 439 } 440 SanCovTraceDivFunction[1] = 441 M.getOrInsertFunction(SanCovTraceDiv8, VoidTy, Int64Ty); 442 SanCovTraceGepFunction = 443 M.getOrInsertFunction(SanCovTraceGep, VoidTy, IntptrTy); 444 SanCovTraceSwitchFunction = 445 M.getOrInsertFunction(SanCovTraceSwitchName, VoidTy, Int64Ty, Int64PtrTy); 446 447 Constant *SanCovLowestStackConstant = 448 M.getOrInsertGlobal(SanCovLowestStackName, IntptrTy); 449 SanCovLowestStack = dyn_cast<GlobalVariable>(SanCovLowestStackConstant); 450 if (!SanCovLowestStack) { 451 C->emitError(StringRef("'") + SanCovLowestStackName + 452 "' should not be declared by the user"); 453 return true; 454 } 455 SanCovLowestStack->setThreadLocalMode( 456 GlobalValue::ThreadLocalMode::InitialExecTLSModel); 457 if (Options.StackDepth && !SanCovLowestStack->isDeclaration()) 458 SanCovLowestStack->setInitializer(Constant::getAllOnesValue(IntptrTy)); 459 460 // We insert an empty inline asm after cov callbacks to avoid callback merge. 461 EmptyAsm = InlineAsm::get(FunctionType::get(IRB.getVoidTy(), false), 462 StringRef(""), StringRef(""), 463 /*hasSideEffects=*/true); 464 465 SanCovTracePC = M.getOrInsertFunction(SanCovTracePCName, VoidTy); 466 SanCovTracePCGuard = 467 M.getOrInsertFunction(SanCovTracePCGuardName, VoidTy, Int32PtrTy); 468 469 for (auto &F : M) 470 instrumentFunction(F, DTCallback, PDTCallback); 471 472 Function *Ctor = nullptr; 473 474 if (FunctionGuardArray) 475 Ctor = CreateInitCallsForSections(M, SanCovModuleCtorTracePcGuardName, 476 SanCovTracePCGuardInitName, Int32PtrTy, 477 SanCovGuardsSectionName); 478 if (Function8bitCounterArray) 479 Ctor = CreateInitCallsForSections(M, SanCovModuleCtor8bitCountersName, 480 SanCov8bitCountersInitName, Int8PtrTy, 481 SanCovCountersSectionName); 482 if (FunctionBoolArray) { 483 Ctor = CreateInitCallsForSections(M, SanCovModuleCtorBoolFlagName, 484 SanCovBoolFlagInitName, Int1PtrTy, 485 SanCovBoolFlagSectionName); 486 } 487 if (Ctor && Options.PCTable) { 488 auto SecStartEnd = CreateSecStartEnd(M, SanCovPCsSectionName, IntptrPtrTy); 489 FunctionCallee InitFunction = declareSanitizerInitFunction( 490 M, SanCovPCsInitName, {IntptrPtrTy, IntptrPtrTy}); 491 IRBuilder<> IRBCtor(Ctor->getEntryBlock().getTerminator()); 492 IRBCtor.CreateCall(InitFunction, {SecStartEnd.first, SecStartEnd.second}); 493 } 494 // We don't reference these arrays directly in any of our runtime functions, 495 // so we need to prevent them from being dead stripped. 496 if (TargetTriple.isOSBinFormatMachO()) 497 appendToUsed(M, GlobalsToAppendToUsed); 498 appendToCompilerUsed(M, GlobalsToAppendToCompilerUsed); 499 return true; 500 } 501 502 // True if block has successors and it dominates all of them. 503 static bool isFullDominator(const BasicBlock *BB, const DominatorTree *DT) { 504 if (succ_begin(BB) == succ_end(BB)) 505 return false; 506 507 for (const BasicBlock *SUCC : make_range(succ_begin(BB), succ_end(BB))) { 508 if (!DT->dominates(BB, SUCC)) 509 return false; 510 } 511 512 return true; 513 } 514 515 // True if block has predecessors and it postdominates all of them. 516 static bool isFullPostDominator(const BasicBlock *BB, 517 const PostDominatorTree *PDT) { 518 if (pred_begin(BB) == pred_end(BB)) 519 return false; 520 521 for (const BasicBlock *PRED : make_range(pred_begin(BB), pred_end(BB))) { 522 if (!PDT->dominates(BB, PRED)) 523 return false; 524 } 525 526 return true; 527 } 528 529 static bool shouldInstrumentBlock(const Function &F, const BasicBlock *BB, 530 const DominatorTree *DT, 531 const PostDominatorTree *PDT, 532 const SanitizerCoverageOptions &Options) { 533 // Don't insert coverage for blocks containing nothing but unreachable: we 534 // will never call __sanitizer_cov() for them, so counting them in 535 // NumberOfInstrumentedBlocks() might complicate calculation of code coverage 536 // percentage. Also, unreachable instructions frequently have no debug 537 // locations. 538 if (isa<UnreachableInst>(BB->getFirstNonPHIOrDbgOrLifetime())) 539 return false; 540 541 // Don't insert coverage into blocks without a valid insertion point 542 // (catchswitch blocks). 543 if (BB->getFirstInsertionPt() == BB->end()) 544 return false; 545 546 if (Options.NoPrune || &F.getEntryBlock() == BB) 547 return true; 548 549 if (Options.CoverageType == SanitizerCoverageOptions::SCK_Function && 550 &F.getEntryBlock() != BB) 551 return false; 552 553 // Do not instrument full dominators, or full post-dominators with multiple 554 // predecessors. 555 return !isFullDominator(BB, DT) 556 && !(isFullPostDominator(BB, PDT) && !BB->getSinglePredecessor()); 557 } 558 559 560 // Returns true iff From->To is a backedge. 561 // A twist here is that we treat From->To as a backedge if 562 // * To dominates From or 563 // * To->UniqueSuccessor dominates From 564 static bool IsBackEdge(BasicBlock *From, BasicBlock *To, 565 const DominatorTree *DT) { 566 if (DT->dominates(To, From)) 567 return true; 568 if (auto Next = To->getUniqueSuccessor()) 569 if (DT->dominates(Next, From)) 570 return true; 571 return false; 572 } 573 574 // Prunes uninteresting Cmp instrumentation: 575 // * CMP instructions that feed into loop backedge branch. 576 // 577 // Note that Cmp pruning is controlled by the same flag as the 578 // BB pruning. 579 static bool IsInterestingCmp(ICmpInst *CMP, const DominatorTree *DT, 580 const SanitizerCoverageOptions &Options) { 581 if (!Options.NoPrune) 582 if (CMP->hasOneUse()) 583 if (auto BR = dyn_cast<BranchInst>(CMP->user_back())) 584 for (BasicBlock *B : BR->successors()) 585 if (IsBackEdge(BR->getParent(), B, DT)) 586 return false; 587 return true; 588 } 589 590 void ModuleSanitizerCoverage::instrumentFunction( 591 Function &F, DomTreeCallback DTCallback, PostDomTreeCallback PDTCallback) { 592 if (F.empty()) 593 return; 594 if (F.getName().find(".module_ctor") != std::string::npos) 595 return; // Should not instrument sanitizer init functions. 596 if (F.getName().startswith("__sanitizer_")) 597 return; // Don't instrument __sanitizer_* callbacks. 598 // Don't touch available_externally functions, their actual body is elewhere. 599 if (F.getLinkage() == GlobalValue::AvailableExternallyLinkage) 600 return; 601 // Don't instrument MSVC CRT configuration helpers. They may run before normal 602 // initialization. 603 if (F.getName() == "__local_stdio_printf_options" || 604 F.getName() == "__local_stdio_scanf_options") 605 return; 606 if (isa<UnreachableInst>(F.getEntryBlock().getTerminator())) 607 return; 608 // Don't instrument functions using SEH for now. Splitting basic blocks like 609 // we do for coverage breaks WinEHPrepare. 610 // FIXME: Remove this when SEH no longer uses landingpad pattern matching. 611 if (F.hasPersonalityFn() && 612 isAsynchronousEHPersonality(classifyEHPersonality(F.getPersonalityFn()))) 613 return; 614 if (Options.CoverageType >= SanitizerCoverageOptions::SCK_Edge) 615 SplitAllCriticalEdges(F, CriticalEdgeSplittingOptions().setIgnoreUnreachableDests()); 616 SmallVector<Instruction *, 8> IndirCalls; 617 SmallVector<BasicBlock *, 16> BlocksToInstrument; 618 SmallVector<Instruction *, 8> CmpTraceTargets; 619 SmallVector<Instruction *, 8> SwitchTraceTargets; 620 SmallVector<BinaryOperator *, 8> DivTraceTargets; 621 SmallVector<GetElementPtrInst *, 8> GepTraceTargets; 622 623 const DominatorTree *DT = DTCallback(F); 624 const PostDominatorTree *PDT = PDTCallback(F); 625 bool IsLeafFunc = true; 626 627 for (auto &BB : F) { 628 if (shouldInstrumentBlock(F, &BB, DT, PDT, Options)) 629 BlocksToInstrument.push_back(&BB); 630 for (auto &Inst : BB) { 631 if (Options.IndirectCalls) { 632 CallSite CS(&Inst); 633 if (CS && !CS.getCalledFunction()) 634 IndirCalls.push_back(&Inst); 635 } 636 if (Options.TraceCmp) { 637 if (ICmpInst *CMP = dyn_cast<ICmpInst>(&Inst)) 638 if (IsInterestingCmp(CMP, DT, Options)) 639 CmpTraceTargets.push_back(&Inst); 640 if (isa<SwitchInst>(&Inst)) 641 SwitchTraceTargets.push_back(&Inst); 642 } 643 if (Options.TraceDiv) 644 if (BinaryOperator *BO = dyn_cast<BinaryOperator>(&Inst)) 645 if (BO->getOpcode() == Instruction::SDiv || 646 BO->getOpcode() == Instruction::UDiv) 647 DivTraceTargets.push_back(BO); 648 if (Options.TraceGep) 649 if (GetElementPtrInst *GEP = dyn_cast<GetElementPtrInst>(&Inst)) 650 GepTraceTargets.push_back(GEP); 651 if (Options.StackDepth) 652 if (isa<InvokeInst>(Inst) || 653 (isa<CallInst>(Inst) && !isa<IntrinsicInst>(Inst))) 654 IsLeafFunc = false; 655 } 656 } 657 658 InjectCoverage(F, BlocksToInstrument, IsLeafFunc); 659 InjectCoverageForIndirectCalls(F, IndirCalls); 660 InjectTraceForCmp(F, CmpTraceTargets); 661 InjectTraceForSwitch(F, SwitchTraceTargets); 662 InjectTraceForDiv(F, DivTraceTargets); 663 InjectTraceForGep(F, GepTraceTargets); 664 } 665 666 GlobalVariable *ModuleSanitizerCoverage::CreateFunctionLocalArrayInSection( 667 size_t NumElements, Function &F, Type *Ty, const char *Section) { 668 ArrayType *ArrayTy = ArrayType::get(Ty, NumElements); 669 auto Array = new GlobalVariable( 670 *CurModule, ArrayTy, false, GlobalVariable::PrivateLinkage, 671 Constant::getNullValue(ArrayTy), "__sancov_gen_"); 672 673 if (TargetTriple.supportsCOMDAT() && !F.isInterposable()) 674 if (auto Comdat = 675 GetOrCreateFunctionComdat(F, TargetTriple, CurModuleUniqueId)) 676 Array->setComdat(Comdat); 677 Array->setSection(getSectionName(Section)); 678 Array->setAlignment(Align(DL->getTypeStoreSize(Ty).getFixedSize())); 679 GlobalsToAppendToUsed.push_back(Array); 680 GlobalsToAppendToCompilerUsed.push_back(Array); 681 MDNode *MD = MDNode::get(F.getContext(), ValueAsMetadata::get(&F)); 682 Array->addMetadata(LLVMContext::MD_associated, *MD); 683 684 return Array; 685 } 686 687 GlobalVariable * 688 ModuleSanitizerCoverage::CreatePCArray(Function &F, 689 ArrayRef<BasicBlock *> AllBlocks) { 690 size_t N = AllBlocks.size(); 691 assert(N); 692 SmallVector<Constant *, 32> PCs; 693 IRBuilder<> IRB(&*F.getEntryBlock().getFirstInsertionPt()); 694 for (size_t i = 0; i < N; i++) { 695 if (&F.getEntryBlock() == AllBlocks[i]) { 696 PCs.push_back((Constant *)IRB.CreatePointerCast(&F, IntptrPtrTy)); 697 PCs.push_back((Constant *)IRB.CreateIntToPtr( 698 ConstantInt::get(IntptrTy, 1), IntptrPtrTy)); 699 } else { 700 PCs.push_back((Constant *)IRB.CreatePointerCast( 701 BlockAddress::get(AllBlocks[i]), IntptrPtrTy)); 702 PCs.push_back((Constant *)IRB.CreateIntToPtr( 703 ConstantInt::get(IntptrTy, 0), IntptrPtrTy)); 704 } 705 } 706 auto *PCArray = CreateFunctionLocalArrayInSection(N * 2, F, IntptrPtrTy, 707 SanCovPCsSectionName); 708 PCArray->setInitializer( 709 ConstantArray::get(ArrayType::get(IntptrPtrTy, N * 2), PCs)); 710 PCArray->setConstant(true); 711 712 return PCArray; 713 } 714 715 void ModuleSanitizerCoverage::CreateFunctionLocalArrays( 716 Function &F, ArrayRef<BasicBlock *> AllBlocks) { 717 if (Options.TracePCGuard) 718 FunctionGuardArray = CreateFunctionLocalArrayInSection( 719 AllBlocks.size(), F, Int32Ty, SanCovGuardsSectionName); 720 721 if (Options.Inline8bitCounters) 722 Function8bitCounterArray = CreateFunctionLocalArrayInSection( 723 AllBlocks.size(), F, Int8Ty, SanCovCountersSectionName); 724 if (Options.InlineBoolFlag) 725 FunctionBoolArray = CreateFunctionLocalArrayInSection( 726 AllBlocks.size(), F, Int1Ty, SanCovBoolFlagSectionName); 727 728 if (Options.PCTable) 729 FunctionPCsArray = CreatePCArray(F, AllBlocks); 730 } 731 732 bool ModuleSanitizerCoverage::InjectCoverage(Function &F, 733 ArrayRef<BasicBlock *> AllBlocks, 734 bool IsLeafFunc) { 735 if (AllBlocks.empty()) return false; 736 CreateFunctionLocalArrays(F, AllBlocks); 737 for (size_t i = 0, N = AllBlocks.size(); i < N; i++) 738 InjectCoverageAtBlock(F, *AllBlocks[i], i, IsLeafFunc); 739 return true; 740 } 741 742 // On every indirect call we call a run-time function 743 // __sanitizer_cov_indir_call* with two parameters: 744 // - callee address, 745 // - global cache array that contains CacheSize pointers (zero-initialized). 746 // The cache is used to speed up recording the caller-callee pairs. 747 // The address of the caller is passed implicitly via caller PC. 748 // CacheSize is encoded in the name of the run-time function. 749 void ModuleSanitizerCoverage::InjectCoverageForIndirectCalls( 750 Function &F, ArrayRef<Instruction *> IndirCalls) { 751 if (IndirCalls.empty()) 752 return; 753 assert(Options.TracePC || Options.TracePCGuard || 754 Options.Inline8bitCounters || Options.InlineBoolFlag); 755 for (auto I : IndirCalls) { 756 IRBuilder<> IRB(I); 757 CallSite CS(I); 758 Value *Callee = CS.getCalledValue(); 759 if (isa<InlineAsm>(Callee)) 760 continue; 761 IRB.CreateCall(SanCovTracePCIndir, IRB.CreatePointerCast(Callee, IntptrTy)); 762 } 763 } 764 765 // For every switch statement we insert a call: 766 // __sanitizer_cov_trace_switch(CondValue, 767 // {NumCases, ValueSizeInBits, Case0Value, Case1Value, Case2Value, ... }) 768 769 void ModuleSanitizerCoverage::InjectTraceForSwitch( 770 Function &, ArrayRef<Instruction *> SwitchTraceTargets) { 771 for (auto I : SwitchTraceTargets) { 772 if (SwitchInst *SI = dyn_cast<SwitchInst>(I)) { 773 IRBuilder<> IRB(I); 774 SmallVector<Constant *, 16> Initializers; 775 Value *Cond = SI->getCondition(); 776 if (Cond->getType()->getScalarSizeInBits() > 777 Int64Ty->getScalarSizeInBits()) 778 continue; 779 Initializers.push_back(ConstantInt::get(Int64Ty, SI->getNumCases())); 780 Initializers.push_back( 781 ConstantInt::get(Int64Ty, Cond->getType()->getScalarSizeInBits())); 782 if (Cond->getType()->getScalarSizeInBits() < 783 Int64Ty->getScalarSizeInBits()) 784 Cond = IRB.CreateIntCast(Cond, Int64Ty, false); 785 for (auto It : SI->cases()) { 786 Constant *C = It.getCaseValue(); 787 if (C->getType()->getScalarSizeInBits() < 788 Int64Ty->getScalarSizeInBits()) 789 C = ConstantExpr::getCast(CastInst::ZExt, It.getCaseValue(), Int64Ty); 790 Initializers.push_back(C); 791 } 792 llvm::sort(Initializers.begin() + 2, Initializers.end(), 793 [](const Constant *A, const Constant *B) { 794 return cast<ConstantInt>(A)->getLimitedValue() < 795 cast<ConstantInt>(B)->getLimitedValue(); 796 }); 797 ArrayType *ArrayOfInt64Ty = ArrayType::get(Int64Ty, Initializers.size()); 798 GlobalVariable *GV = new GlobalVariable( 799 *CurModule, ArrayOfInt64Ty, false, GlobalVariable::InternalLinkage, 800 ConstantArray::get(ArrayOfInt64Ty, Initializers), 801 "__sancov_gen_cov_switch_values"); 802 IRB.CreateCall(SanCovTraceSwitchFunction, 803 {Cond, IRB.CreatePointerCast(GV, Int64PtrTy)}); 804 } 805 } 806 } 807 808 void ModuleSanitizerCoverage::InjectTraceForDiv( 809 Function &, ArrayRef<BinaryOperator *> DivTraceTargets) { 810 for (auto BO : DivTraceTargets) { 811 IRBuilder<> IRB(BO); 812 Value *A1 = BO->getOperand(1); 813 if (isa<ConstantInt>(A1)) continue; 814 if (!A1->getType()->isIntegerTy()) 815 continue; 816 uint64_t TypeSize = DL->getTypeStoreSizeInBits(A1->getType()); 817 int CallbackIdx = TypeSize == 32 ? 0 : 818 TypeSize == 64 ? 1 : -1; 819 if (CallbackIdx < 0) continue; 820 auto Ty = Type::getIntNTy(*C, TypeSize); 821 IRB.CreateCall(SanCovTraceDivFunction[CallbackIdx], 822 {IRB.CreateIntCast(A1, Ty, true)}); 823 } 824 } 825 826 void ModuleSanitizerCoverage::InjectTraceForGep( 827 Function &, ArrayRef<GetElementPtrInst *> GepTraceTargets) { 828 for (auto GEP : GepTraceTargets) { 829 IRBuilder<> IRB(GEP); 830 for (auto I = GEP->idx_begin(); I != GEP->idx_end(); ++I) 831 if (!isa<ConstantInt>(*I) && (*I)->getType()->isIntegerTy()) 832 IRB.CreateCall(SanCovTraceGepFunction, 833 {IRB.CreateIntCast(*I, IntptrTy, true)}); 834 } 835 } 836 837 void ModuleSanitizerCoverage::InjectTraceForCmp( 838 Function &, ArrayRef<Instruction *> CmpTraceTargets) { 839 for (auto I : CmpTraceTargets) { 840 if (ICmpInst *ICMP = dyn_cast<ICmpInst>(I)) { 841 IRBuilder<> IRB(ICMP); 842 Value *A0 = ICMP->getOperand(0); 843 Value *A1 = ICMP->getOperand(1); 844 if (!A0->getType()->isIntegerTy()) 845 continue; 846 uint64_t TypeSize = DL->getTypeStoreSizeInBits(A0->getType()); 847 int CallbackIdx = TypeSize == 8 ? 0 : 848 TypeSize == 16 ? 1 : 849 TypeSize == 32 ? 2 : 850 TypeSize == 64 ? 3 : -1; 851 if (CallbackIdx < 0) continue; 852 // __sanitizer_cov_trace_cmp((type_size << 32) | predicate, A0, A1); 853 auto CallbackFunc = SanCovTraceCmpFunction[CallbackIdx]; 854 bool FirstIsConst = isa<ConstantInt>(A0); 855 bool SecondIsConst = isa<ConstantInt>(A1); 856 // If both are const, then we don't need such a comparison. 857 if (FirstIsConst && SecondIsConst) continue; 858 // If only one is const, then make it the first callback argument. 859 if (FirstIsConst || SecondIsConst) { 860 CallbackFunc = SanCovTraceConstCmpFunction[CallbackIdx]; 861 if (SecondIsConst) 862 std::swap(A0, A1); 863 } 864 865 auto Ty = Type::getIntNTy(*C, TypeSize); 866 IRB.CreateCall(CallbackFunc, {IRB.CreateIntCast(A0, Ty, true), 867 IRB.CreateIntCast(A1, Ty, true)}); 868 } 869 } 870 } 871 872 void ModuleSanitizerCoverage::InjectCoverageAtBlock(Function &F, BasicBlock &BB, 873 size_t Idx, 874 bool IsLeafFunc) { 875 BasicBlock::iterator IP = BB.getFirstInsertionPt(); 876 bool IsEntryBB = &BB == &F.getEntryBlock(); 877 DebugLoc EntryLoc; 878 if (IsEntryBB) { 879 if (auto SP = F.getSubprogram()) 880 EntryLoc = DebugLoc::get(SP->getScopeLine(), 0, SP); 881 // Keep static allocas and llvm.localescape calls in the entry block. Even 882 // if we aren't splitting the block, it's nice for allocas to be before 883 // calls. 884 IP = PrepareToSplitEntryBlock(BB, IP); 885 } else { 886 EntryLoc = IP->getDebugLoc(); 887 } 888 889 IRBuilder<> IRB(&*IP); 890 IRB.SetCurrentDebugLocation(EntryLoc); 891 if (Options.TracePC) { 892 IRB.CreateCall(SanCovTracePC); // gets the PC using GET_CALLER_PC. 893 IRB.CreateCall(EmptyAsm, {}); // Avoids callback merge. 894 } 895 if (Options.TracePCGuard) { 896 auto GuardPtr = IRB.CreateIntToPtr( 897 IRB.CreateAdd(IRB.CreatePointerCast(FunctionGuardArray, IntptrTy), 898 ConstantInt::get(IntptrTy, Idx * 4)), 899 Int32PtrTy); 900 IRB.CreateCall(SanCovTracePCGuard, GuardPtr); 901 IRB.CreateCall(EmptyAsm, {}); // Avoids callback merge. 902 } 903 if (Options.Inline8bitCounters) { 904 auto CounterPtr = IRB.CreateGEP( 905 Function8bitCounterArray->getValueType(), Function8bitCounterArray, 906 {ConstantInt::get(IntptrTy, 0), ConstantInt::get(IntptrTy, Idx)}); 907 auto Load = IRB.CreateLoad(Int8Ty, CounterPtr); 908 auto Inc = IRB.CreateAdd(Load, ConstantInt::get(Int8Ty, 1)); 909 auto Store = IRB.CreateStore(Inc, CounterPtr); 910 SetNoSanitizeMetadata(Load); 911 SetNoSanitizeMetadata(Store); 912 } 913 if (Options.InlineBoolFlag) { 914 auto FlagPtr = IRB.CreateGEP( 915 FunctionBoolArray->getValueType(), FunctionBoolArray, 916 {ConstantInt::get(IntptrTy, 0), ConstantInt::get(IntptrTy, Idx)}); 917 auto Store = IRB.CreateStore(ConstantInt::getTrue(Int1Ty), FlagPtr); 918 SetNoSanitizeMetadata(Store); 919 } 920 if (Options.StackDepth && IsEntryBB && !IsLeafFunc) { 921 // Check stack depth. If it's the deepest so far, record it. 922 Module *M = F.getParent(); 923 Function *GetFrameAddr = Intrinsic::getDeclaration( 924 M, Intrinsic::frameaddress, 925 IRB.getInt8PtrTy(M->getDataLayout().getAllocaAddrSpace())); 926 auto FrameAddrPtr = 927 IRB.CreateCall(GetFrameAddr, {Constant::getNullValue(Int32Ty)}); 928 auto FrameAddrInt = IRB.CreatePtrToInt(FrameAddrPtr, IntptrTy); 929 auto LowestStack = IRB.CreateLoad(IntptrTy, SanCovLowestStack); 930 auto IsStackLower = IRB.CreateICmpULT(FrameAddrInt, LowestStack); 931 auto ThenTerm = SplitBlockAndInsertIfThen(IsStackLower, &*IP, false); 932 IRBuilder<> ThenIRB(ThenTerm); 933 auto Store = ThenIRB.CreateStore(FrameAddrInt, SanCovLowestStack); 934 SetNoSanitizeMetadata(LowestStack); 935 SetNoSanitizeMetadata(Store); 936 } 937 } 938 939 std::string 940 ModuleSanitizerCoverage::getSectionName(const std::string &Section) const { 941 if (TargetTriple.isOSBinFormatCOFF()) { 942 if (Section == SanCovCountersSectionName) 943 return ".SCOV$CM"; 944 if (Section == SanCovBoolFlagSectionName) 945 return ".SCOV$BM"; 946 if (Section == SanCovPCsSectionName) 947 return ".SCOVP$M"; 948 return ".SCOV$GM"; // For SanCovGuardsSectionName. 949 } 950 if (TargetTriple.isOSBinFormatMachO()) 951 return "__DATA,__" + Section; 952 return "__" + Section; 953 } 954 955 std::string 956 ModuleSanitizerCoverage::getSectionStart(const std::string &Section) const { 957 if (TargetTriple.isOSBinFormatMachO()) 958 return "\1section$start$__DATA$__" + Section; 959 return "__start___" + Section; 960 } 961 962 std::string 963 ModuleSanitizerCoverage::getSectionEnd(const std::string &Section) const { 964 if (TargetTriple.isOSBinFormatMachO()) 965 return "\1section$end$__DATA$__" + Section; 966 return "__stop___" + Section; 967 } 968 969 char ModuleSanitizerCoverageLegacyPass::ID = 0; 970 INITIALIZE_PASS_BEGIN(ModuleSanitizerCoverageLegacyPass, "sancov", 971 "Pass for instrumenting coverage on functions", false, 972 false) 973 INITIALIZE_PASS_DEPENDENCY(DominatorTreeWrapperPass) 974 INITIALIZE_PASS_DEPENDENCY(PostDominatorTreeWrapperPass) 975 INITIALIZE_PASS_END(ModuleSanitizerCoverageLegacyPass, "sancov", 976 "Pass for instrumenting coverage on functions", false, 977 false) 978 ModulePass *llvm::createModuleSanitizerCoverageLegacyPassPass( 979 const SanitizerCoverageOptions &Options) { 980 return new ModuleSanitizerCoverageLegacyPass(Options); 981 } 982