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diff --git a/contrib/llvm-project/llvm/lib/Transforms/Instrumentation/SanitizerCoverage.cpp b/contrib/llvm-project/llvm/lib/Transforms/Instrumentation/SanitizerCoverage.cpp
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+//===-- SanitizerCoverage.cpp - coverage instrumentation for sanitizers ---===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+//
+// Coverage instrumentation done on LLVM IR level, works with Sanitizers.
+//
+//===----------------------------------------------------------------------===//
+
+#include "llvm/ADT/ArrayRef.h"
+#include "llvm/ADT/SmallVector.h"
+#include "llvm/Analysis/EHPersonalities.h"
+#include "llvm/Analysis/PostDominators.h"
+#include "llvm/IR/CFG.h"
+#include "llvm/IR/CallSite.h"
+#include "llvm/IR/Constant.h"
+#include "llvm/IR/DataLayout.h"
+#include "llvm/IR/DebugInfo.h"
+#include "llvm/IR/Dominators.h"
+#include "llvm/IR/Function.h"
+#include "llvm/IR/GlobalVariable.h"
+#include "llvm/IR/IRBuilder.h"
+#include "llvm/IR/InlineAsm.h"
+#include "llvm/IR/IntrinsicInst.h"
+#include "llvm/IR/Intrinsics.h"
+#include "llvm/IR/LLVMContext.h"
+#include "llvm/IR/MDBuilder.h"
+#include "llvm/IR/Mangler.h"
+#include "llvm/IR/Module.h"
+#include "llvm/IR/Type.h"
+#include "llvm/Support/CommandLine.h"
+#include "llvm/Support/Debug.h"
+#include "llvm/Support/raw_ostream.h"
+#include "llvm/Transforms/Instrumentation.h"
+#include "llvm/Transforms/Utils/BasicBlockUtils.h"
+#include "llvm/Transforms/Utils/ModuleUtils.h"
+
+using namespace llvm;
+
+#define DEBUG_TYPE "sancov"
+
+static const char *const SanCovTracePCIndirName =
+ "__sanitizer_cov_trace_pc_indir";
+static const char *const SanCovTracePCName = "__sanitizer_cov_trace_pc";
+static const char *const SanCovTraceCmp1 = "__sanitizer_cov_trace_cmp1";
+static const char *const SanCovTraceCmp2 = "__sanitizer_cov_trace_cmp2";
+static const char *const SanCovTraceCmp4 = "__sanitizer_cov_trace_cmp4";
+static const char *const SanCovTraceCmp8 = "__sanitizer_cov_trace_cmp8";
+static const char *const SanCovTraceConstCmp1 =
+ "__sanitizer_cov_trace_const_cmp1";
+static const char *const SanCovTraceConstCmp2 =
+ "__sanitizer_cov_trace_const_cmp2";
+static const char *const SanCovTraceConstCmp4 =
+ "__sanitizer_cov_trace_const_cmp4";
+static const char *const SanCovTraceConstCmp8 =
+ "__sanitizer_cov_trace_const_cmp8";
+static const char *const SanCovTraceDiv4 = "__sanitizer_cov_trace_div4";
+static const char *const SanCovTraceDiv8 = "__sanitizer_cov_trace_div8";
+static const char *const SanCovTraceGep = "__sanitizer_cov_trace_gep";
+static const char *const SanCovTraceSwitchName = "__sanitizer_cov_trace_switch";
+static const char *const SanCovModuleCtorTracePcGuardName =
+ "sancov.module_ctor_trace_pc_guard";
+static const char *const SanCovModuleCtor8bitCountersName =
+ "sancov.module_ctor_8bit_counters";
+static const uint64_t SanCtorAndDtorPriority = 2;
+
+static const char *const SanCovTracePCGuardName =
+ "__sanitizer_cov_trace_pc_guard";
+static const char *const SanCovTracePCGuardInitName =
+ "__sanitizer_cov_trace_pc_guard_init";
+static const char *const SanCov8bitCountersInitName =
+ "__sanitizer_cov_8bit_counters_init";
+static const char *const SanCovPCsInitName = "__sanitizer_cov_pcs_init";
+
+static const char *const SanCovGuardsSectionName = "sancov_guards";
+static const char *const SanCovCountersSectionName = "sancov_cntrs";
+static const char *const SanCovPCsSectionName = "sancov_pcs";
+
+static const char *const SanCovLowestStackName = "__sancov_lowest_stack";
+
+static cl::opt<int> ClCoverageLevel(
+ "sanitizer-coverage-level",
+ cl::desc("Sanitizer Coverage. 0: none, 1: entry block, 2: all blocks, "
+ "3: all blocks and critical edges"),
+ cl::Hidden, cl::init(0));
+
+static cl::opt<bool> ClTracePC("sanitizer-coverage-trace-pc",
+ cl::desc("Experimental pc tracing"), cl::Hidden,
+ cl::init(false));
+
+static cl::opt<bool> ClTracePCGuard("sanitizer-coverage-trace-pc-guard",
+ cl::desc("pc tracing with a guard"),
+ cl::Hidden, cl::init(false));
+
+// If true, we create a global variable that contains PCs of all instrumented
+// BBs, put this global into a named section, and pass this section's bounds
+// to __sanitizer_cov_pcs_init.
+// This way the coverage instrumentation does not need to acquire the PCs
+// at run-time. Works with trace-pc-guard and inline-8bit-counters.
+static cl::opt<bool> ClCreatePCTable("sanitizer-coverage-pc-table",
+ cl::desc("create a static PC table"),
+ cl::Hidden, cl::init(false));
+
+static cl::opt<bool>
+ ClInline8bitCounters("sanitizer-coverage-inline-8bit-counters",
+ cl::desc("increments 8-bit counter for every edge"),
+ cl::Hidden, cl::init(false));
+
+static cl::opt<bool>
+ ClCMPTracing("sanitizer-coverage-trace-compares",
+ cl::desc("Tracing of CMP and similar instructions"),
+ cl::Hidden, cl::init(false));
+
+static cl::opt<bool> ClDIVTracing("sanitizer-coverage-trace-divs",
+ cl::desc("Tracing of DIV instructions"),
+ cl::Hidden, cl::init(false));
+
+static cl::opt<bool> ClGEPTracing("sanitizer-coverage-trace-geps",
+ cl::desc("Tracing of GEP instructions"),
+ cl::Hidden, cl::init(false));
+
+static cl::opt<bool>
+ ClPruneBlocks("sanitizer-coverage-prune-blocks",
+ cl::desc("Reduce the number of instrumented blocks"),
+ cl::Hidden, cl::init(true));
+
+static cl::opt<bool> ClStackDepth("sanitizer-coverage-stack-depth",
+ cl::desc("max stack depth tracing"),
+ cl::Hidden, cl::init(false));
+
+namespace {
+
+SanitizerCoverageOptions getOptions(int LegacyCoverageLevel) {
+ SanitizerCoverageOptions Res;
+ switch (LegacyCoverageLevel) {
+ case 0:
+ Res.CoverageType = SanitizerCoverageOptions::SCK_None;
+ break;
+ case 1:
+ Res.CoverageType = SanitizerCoverageOptions::SCK_Function;
+ break;
+ case 2:
+ Res.CoverageType = SanitizerCoverageOptions::SCK_BB;
+ break;
+ case 3:
+ Res.CoverageType = SanitizerCoverageOptions::SCK_Edge;
+ break;
+ case 4:
+ Res.CoverageType = SanitizerCoverageOptions::SCK_Edge;
+ Res.IndirectCalls = true;
+ break;
+ }
+ return Res;
+}
+
+SanitizerCoverageOptions OverrideFromCL(SanitizerCoverageOptions Options) {
+ // Sets CoverageType and IndirectCalls.
+ SanitizerCoverageOptions CLOpts = getOptions(ClCoverageLevel);
+ Options.CoverageType = std::max(Options.CoverageType, CLOpts.CoverageType);
+ Options.IndirectCalls |= CLOpts.IndirectCalls;
+ Options.TraceCmp |= ClCMPTracing;
+ Options.TraceDiv |= ClDIVTracing;
+ Options.TraceGep |= ClGEPTracing;
+ Options.TracePC |= ClTracePC;
+ Options.TracePCGuard |= ClTracePCGuard;
+ Options.Inline8bitCounters |= ClInline8bitCounters;
+ Options.PCTable |= ClCreatePCTable;
+ Options.NoPrune |= !ClPruneBlocks;
+ Options.StackDepth |= ClStackDepth;
+ if (!Options.TracePCGuard && !Options.TracePC &&
+ !Options.Inline8bitCounters && !Options.StackDepth)
+ Options.TracePCGuard = true; // TracePCGuard is default.
+ return Options;
+}
+
+class SanitizerCoverageModule : public ModulePass {
+public:
+ SanitizerCoverageModule(
+ const SanitizerCoverageOptions &Options = SanitizerCoverageOptions())
+ : ModulePass(ID), Options(OverrideFromCL(Options)) {
+ initializeSanitizerCoverageModulePass(*PassRegistry::getPassRegistry());
+ }
+ bool runOnModule(Module &M) override;
+ bool runOnFunction(Function &F);
+ static char ID; // Pass identification, replacement for typeid
+ StringRef getPassName() const override { return "SanitizerCoverageModule"; }
+
+ void getAnalysisUsage(AnalysisUsage &AU) const override {
+ AU.addRequired<DominatorTreeWrapperPass>();
+ AU.addRequired<PostDominatorTreeWrapperPass>();
+ }
+
+private:
+ void InjectCoverageForIndirectCalls(Function &F,
+ ArrayRef<Instruction *> IndirCalls);
+ void InjectTraceForCmp(Function &F, ArrayRef<Instruction *> CmpTraceTargets);
+ void InjectTraceForDiv(Function &F,
+ ArrayRef<BinaryOperator *> DivTraceTargets);
+ void InjectTraceForGep(Function &F,
+ ArrayRef<GetElementPtrInst *> GepTraceTargets);
+ void InjectTraceForSwitch(Function &F,
+ ArrayRef<Instruction *> SwitchTraceTargets);
+ bool InjectCoverage(Function &F, ArrayRef<BasicBlock *> AllBlocks,
+ bool IsLeafFunc = true);
+ GlobalVariable *CreateFunctionLocalArrayInSection(size_t NumElements,
+ Function &F, Type *Ty,
+ const char *Section);
+ GlobalVariable *CreatePCArray(Function &F, ArrayRef<BasicBlock *> AllBlocks);
+ void CreateFunctionLocalArrays(Function &F, ArrayRef<BasicBlock *> AllBlocks);
+ void InjectCoverageAtBlock(Function &F, BasicBlock &BB, size_t Idx,
+ bool IsLeafFunc = true);
+ Function *CreateInitCallsForSections(Module &M, const char *CtorName,
+ const char *InitFunctionName, Type *Ty,
+ const char *Section);
+ std::pair<Value *, Value *> CreateSecStartEnd(Module &M, const char *Section,
+ Type *Ty);
+
+ void SetNoSanitizeMetadata(Instruction *I) {
+ I->setMetadata(I->getModule()->getMDKindID("nosanitize"),
+ MDNode::get(*C, None));
+ }
+
+ std::string getSectionName(const std::string &Section) const;
+ std::string getSectionStart(const std::string &Section) const;
+ std::string getSectionEnd(const std::string &Section) const;
+ FunctionCallee SanCovTracePCIndir;
+ FunctionCallee SanCovTracePC, SanCovTracePCGuard;
+ FunctionCallee SanCovTraceCmpFunction[4];
+ FunctionCallee SanCovTraceConstCmpFunction[4];
+ FunctionCallee SanCovTraceDivFunction[2];
+ FunctionCallee SanCovTraceGepFunction;
+ FunctionCallee SanCovTraceSwitchFunction;
+ GlobalVariable *SanCovLowestStack;
+ InlineAsm *EmptyAsm;
+ Type *IntptrTy, *IntptrPtrTy, *Int64Ty, *Int64PtrTy, *Int32Ty, *Int32PtrTy,
+ *Int16Ty, *Int8Ty, *Int8PtrTy;
+ Module *CurModule;
+ std::string CurModuleUniqueId;
+ Triple TargetTriple;
+ LLVMContext *C;
+ const DataLayout *DL;
+
+ GlobalVariable *FunctionGuardArray; // for trace-pc-guard.
+ GlobalVariable *Function8bitCounterArray; // for inline-8bit-counters.
+ GlobalVariable *FunctionPCsArray; // for pc-table.
+ SmallVector<GlobalValue *, 20> GlobalsToAppendToUsed;
+ SmallVector<GlobalValue *, 20> GlobalsToAppendToCompilerUsed;
+
+ SanitizerCoverageOptions Options;
+};
+
+} // namespace
+
+std::pair<Value *, Value *>
+SanitizerCoverageModule::CreateSecStartEnd(Module &M, const char *Section,
+ Type *Ty) {
+ GlobalVariable *SecStart =
+ new GlobalVariable(M, Ty, false, GlobalVariable::ExternalLinkage, nullptr,
+ getSectionStart(Section));
+ SecStart->setVisibility(GlobalValue::HiddenVisibility);
+ GlobalVariable *SecEnd =
+ new GlobalVariable(M, Ty, false, GlobalVariable::ExternalLinkage,
+ nullptr, getSectionEnd(Section));
+ SecEnd->setVisibility(GlobalValue::HiddenVisibility);
+ IRBuilder<> IRB(M.getContext());
+ Value *SecEndPtr = IRB.CreatePointerCast(SecEnd, Ty);
+ if (!TargetTriple.isOSBinFormatCOFF())
+ return std::make_pair(IRB.CreatePointerCast(SecStart, Ty), SecEndPtr);
+
+ // Account for the fact that on windows-msvc __start_* symbols actually
+ // point to a uint64_t before the start of the array.
+ auto SecStartI8Ptr = IRB.CreatePointerCast(SecStart, Int8PtrTy);
+ auto GEP = IRB.CreateGEP(Int8Ty, SecStartI8Ptr,
+ ConstantInt::get(IntptrTy, sizeof(uint64_t)));
+ return std::make_pair(IRB.CreatePointerCast(GEP, Ty), SecEndPtr);
+}
+
+Function *SanitizerCoverageModule::CreateInitCallsForSections(
+ Module &M, const char *CtorName, const char *InitFunctionName, Type *Ty,
+ const char *Section) {
+ auto SecStartEnd = CreateSecStartEnd(M, Section, Ty);
+ auto SecStart = SecStartEnd.first;
+ auto SecEnd = SecStartEnd.second;
+ Function *CtorFunc;
+ std::tie(CtorFunc, std::ignore) = createSanitizerCtorAndInitFunctions(
+ M, CtorName, InitFunctionName, {Ty, Ty}, {SecStart, SecEnd});
+ assert(CtorFunc->getName() == CtorName);
+
+ if (TargetTriple.supportsCOMDAT()) {
+ // Use comdat to dedup CtorFunc.
+ CtorFunc->setComdat(M.getOrInsertComdat(CtorName));
+ appendToGlobalCtors(M, CtorFunc, SanCtorAndDtorPriority, CtorFunc);
+ } else {
+ appendToGlobalCtors(M, CtorFunc, SanCtorAndDtorPriority);
+ }
+
+ if (TargetTriple.isOSBinFormatCOFF()) {
+ // In COFF files, if the contructors are set as COMDAT (they are because
+ // COFF supports COMDAT) and the linker flag /OPT:REF (strip unreferenced
+ // functions and data) is used, the constructors get stripped. To prevent
+ // this, give the constructors weak ODR linkage and ensure the linker knows
+ // to include the sancov constructor. This way the linker can deduplicate
+ // the constructors but always leave one copy.
+ CtorFunc->setLinkage(GlobalValue::WeakODRLinkage);
+ appendToUsed(M, CtorFunc);
+ }
+ return CtorFunc;
+}
+
+bool SanitizerCoverageModule::runOnModule(Module &M) {
+ if (Options.CoverageType == SanitizerCoverageOptions::SCK_None)
+ return false;
+ C = &(M.getContext());
+ DL = &M.getDataLayout();
+ CurModule = &M;
+ CurModuleUniqueId = getUniqueModuleId(CurModule);
+ TargetTriple = Triple(M.getTargetTriple());
+ FunctionGuardArray = nullptr;
+ Function8bitCounterArray = nullptr;
+ FunctionPCsArray = nullptr;
+ IntptrTy = Type::getIntNTy(*C, DL->getPointerSizeInBits());
+ IntptrPtrTy = PointerType::getUnqual(IntptrTy);
+ Type *VoidTy = Type::getVoidTy(*C);
+ IRBuilder<> IRB(*C);
+ Int64PtrTy = PointerType::getUnqual(IRB.getInt64Ty());
+ Int32PtrTy = PointerType::getUnqual(IRB.getInt32Ty());
+ Int8PtrTy = PointerType::getUnqual(IRB.getInt8Ty());
+ Int64Ty = IRB.getInt64Ty();
+ Int32Ty = IRB.getInt32Ty();
+ Int16Ty = IRB.getInt16Ty();
+ Int8Ty = IRB.getInt8Ty();
+
+ SanCovTracePCIndir =
+ M.getOrInsertFunction(SanCovTracePCIndirName, VoidTy, IntptrTy);
+ // Make sure smaller parameters are zero-extended to i64 as required by the
+ // x86_64 ABI.
+ AttributeList SanCovTraceCmpZeroExtAL;
+ if (TargetTriple.getArch() == Triple::x86_64) {
+ SanCovTraceCmpZeroExtAL =
+ SanCovTraceCmpZeroExtAL.addParamAttribute(*C, 0, Attribute::ZExt);
+ SanCovTraceCmpZeroExtAL =
+ SanCovTraceCmpZeroExtAL.addParamAttribute(*C, 1, Attribute::ZExt);
+ }
+
+ SanCovTraceCmpFunction[0] =
+ M.getOrInsertFunction(SanCovTraceCmp1, SanCovTraceCmpZeroExtAL, VoidTy,
+ IRB.getInt8Ty(), IRB.getInt8Ty());
+ SanCovTraceCmpFunction[1] =
+ M.getOrInsertFunction(SanCovTraceCmp2, SanCovTraceCmpZeroExtAL, VoidTy,
+ IRB.getInt16Ty(), IRB.getInt16Ty());
+ SanCovTraceCmpFunction[2] =
+ M.getOrInsertFunction(SanCovTraceCmp4, SanCovTraceCmpZeroExtAL, VoidTy,
+ IRB.getInt32Ty(), IRB.getInt32Ty());
+ SanCovTraceCmpFunction[3] =
+ M.getOrInsertFunction(SanCovTraceCmp8, VoidTy, Int64Ty, Int64Ty);
+
+ SanCovTraceConstCmpFunction[0] = M.getOrInsertFunction(
+ SanCovTraceConstCmp1, SanCovTraceCmpZeroExtAL, VoidTy, Int8Ty, Int8Ty);
+ SanCovTraceConstCmpFunction[1] = M.getOrInsertFunction(
+ SanCovTraceConstCmp2, SanCovTraceCmpZeroExtAL, VoidTy, Int16Ty, Int16Ty);
+ SanCovTraceConstCmpFunction[2] = M.getOrInsertFunction(
+ SanCovTraceConstCmp4, SanCovTraceCmpZeroExtAL, VoidTy, Int32Ty, Int32Ty);
+ SanCovTraceConstCmpFunction[3] =
+ M.getOrInsertFunction(SanCovTraceConstCmp8, VoidTy, Int64Ty, Int64Ty);
+
+ {
+ AttributeList AL;
+ if (TargetTriple.getArch() == Triple::x86_64)
+ AL = AL.addParamAttribute(*C, 0, Attribute::ZExt);
+ SanCovTraceDivFunction[0] =
+ M.getOrInsertFunction(SanCovTraceDiv4, AL, VoidTy, IRB.getInt32Ty());
+ }
+ SanCovTraceDivFunction[1] =
+ M.getOrInsertFunction(SanCovTraceDiv8, VoidTy, Int64Ty);
+ SanCovTraceGepFunction =
+ M.getOrInsertFunction(SanCovTraceGep, VoidTy, IntptrTy);
+ SanCovTraceSwitchFunction =
+ M.getOrInsertFunction(SanCovTraceSwitchName, VoidTy, Int64Ty, Int64PtrTy);
+
+ Constant *SanCovLowestStackConstant =
+ M.getOrInsertGlobal(SanCovLowestStackName, IntptrTy);
+ SanCovLowestStack = dyn_cast<GlobalVariable>(SanCovLowestStackConstant);
+ if (!SanCovLowestStack) {
+ C->emitError(StringRef("'") + SanCovLowestStackName +
+ "' should not be declared by the user");
+ return true;
+ }
+ SanCovLowestStack->setThreadLocalMode(
+ GlobalValue::ThreadLocalMode::InitialExecTLSModel);
+ if (Options.StackDepth && !SanCovLowestStack->isDeclaration())
+ SanCovLowestStack->setInitializer(Constant::getAllOnesValue(IntptrTy));
+
+ // We insert an empty inline asm after cov callbacks to avoid callback merge.
+ EmptyAsm = InlineAsm::get(FunctionType::get(IRB.getVoidTy(), false),
+ StringRef(""), StringRef(""),
+ /*hasSideEffects=*/true);
+
+ SanCovTracePC = M.getOrInsertFunction(SanCovTracePCName, VoidTy);
+ SanCovTracePCGuard =
+ M.getOrInsertFunction(SanCovTracePCGuardName, VoidTy, Int32PtrTy);
+
+ for (auto &F : M)
+ runOnFunction(F);
+
+ Function *Ctor = nullptr;
+
+ if (FunctionGuardArray)
+ Ctor = CreateInitCallsForSections(M, SanCovModuleCtorTracePcGuardName,
+ SanCovTracePCGuardInitName, Int32PtrTy,
+ SanCovGuardsSectionName);
+ if (Function8bitCounterArray)
+ Ctor = CreateInitCallsForSections(M, SanCovModuleCtor8bitCountersName,
+ SanCov8bitCountersInitName, Int8PtrTy,
+ SanCovCountersSectionName);
+ if (Ctor && Options.PCTable) {
+ auto SecStartEnd = CreateSecStartEnd(M, SanCovPCsSectionName, IntptrPtrTy);
+ FunctionCallee InitFunction = declareSanitizerInitFunction(
+ M, SanCovPCsInitName, {IntptrPtrTy, IntptrPtrTy});
+ IRBuilder<> IRBCtor(Ctor->getEntryBlock().getTerminator());
+ IRBCtor.CreateCall(InitFunction, {SecStartEnd.first, SecStartEnd.second});
+ }
+ // We don't reference these arrays directly in any of our runtime functions,
+ // so we need to prevent them from being dead stripped.
+ if (TargetTriple.isOSBinFormatMachO())
+ appendToUsed(M, GlobalsToAppendToUsed);
+ appendToCompilerUsed(M, GlobalsToAppendToCompilerUsed);
+ return true;
+}
+
+// True if block has successors and it dominates all of them.
+static bool isFullDominator(const BasicBlock *BB, const DominatorTree *DT) {
+ if (succ_begin(BB) == succ_end(BB))
+ return false;
+
+ for (const BasicBlock *SUCC : make_range(succ_begin(BB), succ_end(BB))) {
+ if (!DT->dominates(BB, SUCC))
+ return false;
+ }
+
+ return true;
+}
+
+// True if block has predecessors and it postdominates all of them.
+static bool isFullPostDominator(const BasicBlock *BB,
+ const PostDominatorTree *PDT) {
+ if (pred_begin(BB) == pred_end(BB))
+ return false;
+
+ for (const BasicBlock *PRED : make_range(pred_begin(BB), pred_end(BB))) {
+ if (!PDT->dominates(BB, PRED))
+ return false;
+ }
+
+ return true;
+}
+
+static bool shouldInstrumentBlock(const Function &F, const BasicBlock *BB,
+ const DominatorTree *DT,
+ const PostDominatorTree *PDT,
+ const SanitizerCoverageOptions &Options) {
+ // Don't insert coverage for blocks containing nothing but unreachable: we
+ // will never call __sanitizer_cov() for them, so counting them in
+ // NumberOfInstrumentedBlocks() might complicate calculation of code coverage
+ // percentage. Also, unreachable instructions frequently have no debug
+ // locations.
+ if (isa<UnreachableInst>(BB->getFirstNonPHIOrDbgOrLifetime()))
+ return false;
+
+ // Don't insert coverage into blocks without a valid insertion point
+ // (catchswitch blocks).
+ if (BB->getFirstInsertionPt() == BB->end())
+ return false;
+
+ if (Options.NoPrune || &F.getEntryBlock() == BB)
+ return true;
+
+ if (Options.CoverageType == SanitizerCoverageOptions::SCK_Function &&
+ &F.getEntryBlock() != BB)
+ return false;
+
+ // Do not instrument full dominators, or full post-dominators with multiple
+ // predecessors.
+ return !isFullDominator(BB, DT)
+ && !(isFullPostDominator(BB, PDT) && !BB->getSinglePredecessor());
+}
+
+
+// Returns true iff From->To is a backedge.
+// A twist here is that we treat From->To as a backedge if
+// * To dominates From or
+// * To->UniqueSuccessor dominates From
+static bool IsBackEdge(BasicBlock *From, BasicBlock *To,
+ const DominatorTree *DT) {
+ if (DT->dominates(To, From))
+ return true;
+ if (auto Next = To->getUniqueSuccessor())
+ if (DT->dominates(Next, From))
+ return true;
+ return false;
+}
+
+// Prunes uninteresting Cmp instrumentation:
+// * CMP instructions that feed into loop backedge branch.
+//
+// Note that Cmp pruning is controlled by the same flag as the
+// BB pruning.
+static bool IsInterestingCmp(ICmpInst *CMP, const DominatorTree *DT,
+ const SanitizerCoverageOptions &Options) {
+ if (!Options.NoPrune)
+ if (CMP->hasOneUse())
+ if (auto BR = dyn_cast<BranchInst>(CMP->user_back()))
+ for (BasicBlock *B : BR->successors())
+ if (IsBackEdge(BR->getParent(), B, DT))
+ return false;
+ return true;
+}
+
+bool SanitizerCoverageModule::runOnFunction(Function &F) {
+ if (F.empty())
+ return false;
+ if (F.getName().find(".module_ctor") != std::string::npos)
+ return false; // Should not instrument sanitizer init functions.
+ if (F.getName().startswith("__sanitizer_"))
+ return false; // Don't instrument __sanitizer_* callbacks.
+ // Don't touch available_externally functions, their actual body is elewhere.
+ if (F.getLinkage() == GlobalValue::AvailableExternallyLinkage)
+ return false;
+ // Don't instrument MSVC CRT configuration helpers. They may run before normal
+ // initialization.
+ if (F.getName() == "__local_stdio_printf_options" ||
+ F.getName() == "__local_stdio_scanf_options")
+ return false;
+ if (isa<UnreachableInst>(F.getEntryBlock().getTerminator()))
+ return false;
+ // Don't instrument functions using SEH for now. Splitting basic blocks like
+ // we do for coverage breaks WinEHPrepare.
+ // FIXME: Remove this when SEH no longer uses landingpad pattern matching.
+ if (F.hasPersonalityFn() &&
+ isAsynchronousEHPersonality(classifyEHPersonality(F.getPersonalityFn())))
+ return false;
+ if (Options.CoverageType >= SanitizerCoverageOptions::SCK_Edge)
+ SplitAllCriticalEdges(F, CriticalEdgeSplittingOptions().setIgnoreUnreachableDests());
+ SmallVector<Instruction *, 8> IndirCalls;
+ SmallVector<BasicBlock *, 16> BlocksToInstrument;
+ SmallVector<Instruction *, 8> CmpTraceTargets;
+ SmallVector<Instruction *, 8> SwitchTraceTargets;
+ SmallVector<BinaryOperator *, 8> DivTraceTargets;
+ SmallVector<GetElementPtrInst *, 8> GepTraceTargets;
+
+ const DominatorTree *DT =
+ &getAnalysis<DominatorTreeWrapperPass>(F).getDomTree();
+ const PostDominatorTree *PDT =
+ &getAnalysis<PostDominatorTreeWrapperPass>(F).getPostDomTree();
+ bool IsLeafFunc = true;
+
+ for (auto &BB : F) {
+ if (shouldInstrumentBlock(F, &BB, DT, PDT, Options))
+ BlocksToInstrument.push_back(&BB);
+ for (auto &Inst : BB) {
+ if (Options.IndirectCalls) {
+ CallSite CS(&Inst);
+ if (CS && !CS.getCalledFunction())
+ IndirCalls.push_back(&Inst);
+ }
+ if (Options.TraceCmp) {
+ if (ICmpInst *CMP = dyn_cast<ICmpInst>(&Inst))
+ if (IsInterestingCmp(CMP, DT, Options))
+ CmpTraceTargets.push_back(&Inst);
+ if (isa<SwitchInst>(&Inst))
+ SwitchTraceTargets.push_back(&Inst);
+ }
+ if (Options.TraceDiv)
+ if (BinaryOperator *BO = dyn_cast<BinaryOperator>(&Inst))
+ if (BO->getOpcode() == Instruction::SDiv ||
+ BO->getOpcode() == Instruction::UDiv)
+ DivTraceTargets.push_back(BO);
+ if (Options.TraceGep)
+ if (GetElementPtrInst *GEP = dyn_cast<GetElementPtrInst>(&Inst))
+ GepTraceTargets.push_back(GEP);
+ if (Options.StackDepth)
+ if (isa<InvokeInst>(Inst) ||
+ (isa<CallInst>(Inst) && !isa<IntrinsicInst>(Inst)))
+ IsLeafFunc = false;
+ }
+ }
+
+ InjectCoverage(F, BlocksToInstrument, IsLeafFunc);
+ InjectCoverageForIndirectCalls(F, IndirCalls);
+ InjectTraceForCmp(F, CmpTraceTargets);
+ InjectTraceForSwitch(F, SwitchTraceTargets);
+ InjectTraceForDiv(F, DivTraceTargets);
+ InjectTraceForGep(F, GepTraceTargets);
+ return true;
+}
+
+GlobalVariable *SanitizerCoverageModule::CreateFunctionLocalArrayInSection(
+ size_t NumElements, Function &F, Type *Ty, const char *Section) {
+ ArrayType *ArrayTy = ArrayType::get(Ty, NumElements);
+ auto Array = new GlobalVariable(
+ *CurModule, ArrayTy, false, GlobalVariable::PrivateLinkage,
+ Constant::getNullValue(ArrayTy), "__sancov_gen_");
+
+ if (TargetTriple.supportsCOMDAT() && !F.isInterposable())
+ if (auto Comdat =
+ GetOrCreateFunctionComdat(F, TargetTriple, CurModuleUniqueId))
+ Array->setComdat(Comdat);
+ Array->setSection(getSectionName(Section));
+ Array->setAlignment(Ty->isPointerTy() ? DL->getPointerSize()
+ : Ty->getPrimitiveSizeInBits() / 8);
+ GlobalsToAppendToUsed.push_back(Array);
+ GlobalsToAppendToCompilerUsed.push_back(Array);
+ MDNode *MD = MDNode::get(F.getContext(), ValueAsMetadata::get(&F));
+ Array->addMetadata(LLVMContext::MD_associated, *MD);
+
+ return Array;
+}
+
+GlobalVariable *
+SanitizerCoverageModule::CreatePCArray(Function &F,
+ ArrayRef<BasicBlock *> AllBlocks) {
+ size_t N = AllBlocks.size();
+ assert(N);
+ SmallVector<Constant *, 32> PCs;
+ IRBuilder<> IRB(&*F.getEntryBlock().getFirstInsertionPt());
+ for (size_t i = 0; i < N; i++) {
+ if (&F.getEntryBlock() == AllBlocks[i]) {
+ PCs.push_back((Constant *)IRB.CreatePointerCast(&F, IntptrPtrTy));
+ PCs.push_back((Constant *)IRB.CreateIntToPtr(
+ ConstantInt::get(IntptrTy, 1), IntptrPtrTy));
+ } else {
+ PCs.push_back((Constant *)IRB.CreatePointerCast(
+ BlockAddress::get(AllBlocks[i]), IntptrPtrTy));
+ PCs.push_back((Constant *)IRB.CreateIntToPtr(
+ ConstantInt::get(IntptrTy, 0), IntptrPtrTy));
+ }
+ }
+ auto *PCArray = CreateFunctionLocalArrayInSection(N * 2, F, IntptrPtrTy,
+ SanCovPCsSectionName);
+ PCArray->setInitializer(
+ ConstantArray::get(ArrayType::get(IntptrPtrTy, N * 2), PCs));
+ PCArray->setConstant(true);
+
+ return PCArray;
+}
+
+void SanitizerCoverageModule::CreateFunctionLocalArrays(
+ Function &F, ArrayRef<BasicBlock *> AllBlocks) {
+ if (Options.TracePCGuard)
+ FunctionGuardArray = CreateFunctionLocalArrayInSection(
+ AllBlocks.size(), F, Int32Ty, SanCovGuardsSectionName);
+
+ if (Options.Inline8bitCounters)
+ Function8bitCounterArray = CreateFunctionLocalArrayInSection(
+ AllBlocks.size(), F, Int8Ty, SanCovCountersSectionName);
+
+ if (Options.PCTable)
+ FunctionPCsArray = CreatePCArray(F, AllBlocks);
+}
+
+bool SanitizerCoverageModule::InjectCoverage(Function &F,
+ ArrayRef<BasicBlock *> AllBlocks,
+ bool IsLeafFunc) {
+ if (AllBlocks.empty()) return false;
+ CreateFunctionLocalArrays(F, AllBlocks);
+ for (size_t i = 0, N = AllBlocks.size(); i < N; i++)
+ InjectCoverageAtBlock(F, *AllBlocks[i], i, IsLeafFunc);
+ return true;
+}
+
+// On every indirect call we call a run-time function
+// __sanitizer_cov_indir_call* with two parameters:
+// - callee address,
+// - global cache array that contains CacheSize pointers (zero-initialized).
+// The cache is used to speed up recording the caller-callee pairs.
+// The address of the caller is passed implicitly via caller PC.
+// CacheSize is encoded in the name of the run-time function.
+void SanitizerCoverageModule::InjectCoverageForIndirectCalls(
+ Function &F, ArrayRef<Instruction *> IndirCalls) {
+ if (IndirCalls.empty())
+ return;
+ assert(Options.TracePC || Options.TracePCGuard || Options.Inline8bitCounters);
+ for (auto I : IndirCalls) {
+ IRBuilder<> IRB(I);
+ CallSite CS(I);
+ Value *Callee = CS.getCalledValue();
+ if (isa<InlineAsm>(Callee))
+ continue;
+ IRB.CreateCall(SanCovTracePCIndir, IRB.CreatePointerCast(Callee, IntptrTy));
+ }
+}
+
+// For every switch statement we insert a call:
+// __sanitizer_cov_trace_switch(CondValue,
+// {NumCases, ValueSizeInBits, Case0Value, Case1Value, Case2Value, ... })
+
+void SanitizerCoverageModule::InjectTraceForSwitch(
+ Function &, ArrayRef<Instruction *> SwitchTraceTargets) {
+ for (auto I : SwitchTraceTargets) {
+ if (SwitchInst *SI = dyn_cast<SwitchInst>(I)) {
+ IRBuilder<> IRB(I);
+ SmallVector<Constant *, 16> Initializers;
+ Value *Cond = SI->getCondition();
+ if (Cond->getType()->getScalarSizeInBits() >
+ Int64Ty->getScalarSizeInBits())
+ continue;
+ Initializers.push_back(ConstantInt::get(Int64Ty, SI->getNumCases()));
+ Initializers.push_back(
+ ConstantInt::get(Int64Ty, Cond->getType()->getScalarSizeInBits()));
+ if (Cond->getType()->getScalarSizeInBits() <
+ Int64Ty->getScalarSizeInBits())
+ Cond = IRB.CreateIntCast(Cond, Int64Ty, false);
+ for (auto It : SI->cases()) {
+ Constant *C = It.getCaseValue();
+ if (C->getType()->getScalarSizeInBits() <
+ Int64Ty->getScalarSizeInBits())
+ C = ConstantExpr::getCast(CastInst::ZExt, It.getCaseValue(), Int64Ty);
+ Initializers.push_back(C);
+ }
+ llvm::sort(Initializers.begin() + 2, Initializers.end(),
+ [](const Constant *A, const Constant *B) {
+ return cast<ConstantInt>(A)->getLimitedValue() <
+ cast<ConstantInt>(B)->getLimitedValue();
+ });
+ ArrayType *ArrayOfInt64Ty = ArrayType::get(Int64Ty, Initializers.size());
+ GlobalVariable *GV = new GlobalVariable(
+ *CurModule, ArrayOfInt64Ty, false, GlobalVariable::InternalLinkage,
+ ConstantArray::get(ArrayOfInt64Ty, Initializers),
+ "__sancov_gen_cov_switch_values");
+ IRB.CreateCall(SanCovTraceSwitchFunction,
+ {Cond, IRB.CreatePointerCast(GV, Int64PtrTy)});
+ }
+ }
+}
+
+void SanitizerCoverageModule::InjectTraceForDiv(
+ Function &, ArrayRef<BinaryOperator *> DivTraceTargets) {
+ for (auto BO : DivTraceTargets) {
+ IRBuilder<> IRB(BO);
+ Value *A1 = BO->getOperand(1);
+ if (isa<ConstantInt>(A1)) continue;
+ if (!A1->getType()->isIntegerTy())
+ continue;
+ uint64_t TypeSize = DL->getTypeStoreSizeInBits(A1->getType());
+ int CallbackIdx = TypeSize == 32 ? 0 :
+ TypeSize == 64 ? 1 : -1;
+ if (CallbackIdx < 0) continue;
+ auto Ty = Type::getIntNTy(*C, TypeSize);
+ IRB.CreateCall(SanCovTraceDivFunction[CallbackIdx],
+ {IRB.CreateIntCast(A1, Ty, true)});
+ }
+}
+
+void SanitizerCoverageModule::InjectTraceForGep(
+ Function &, ArrayRef<GetElementPtrInst *> GepTraceTargets) {
+ for (auto GEP : GepTraceTargets) {
+ IRBuilder<> IRB(GEP);
+ for (auto I = GEP->idx_begin(); I != GEP->idx_end(); ++I)
+ if (!isa<ConstantInt>(*I) && (*I)->getType()->isIntegerTy())
+ IRB.CreateCall(SanCovTraceGepFunction,
+ {IRB.CreateIntCast(*I, IntptrTy, true)});
+ }
+}
+
+void SanitizerCoverageModule::InjectTraceForCmp(
+ Function &, ArrayRef<Instruction *> CmpTraceTargets) {
+ for (auto I : CmpTraceTargets) {
+ if (ICmpInst *ICMP = dyn_cast<ICmpInst>(I)) {
+ IRBuilder<> IRB(ICMP);
+ Value *A0 = ICMP->getOperand(0);
+ Value *A1 = ICMP->getOperand(1);
+ if (!A0->getType()->isIntegerTy())
+ continue;
+ uint64_t TypeSize = DL->getTypeStoreSizeInBits(A0->getType());
+ int CallbackIdx = TypeSize == 8 ? 0 :
+ TypeSize == 16 ? 1 :
+ TypeSize == 32 ? 2 :
+ TypeSize == 64 ? 3 : -1;
+ if (CallbackIdx < 0) continue;
+ // __sanitizer_cov_trace_cmp((type_size << 32) | predicate, A0, A1);
+ auto CallbackFunc = SanCovTraceCmpFunction[CallbackIdx];
+ bool FirstIsConst = isa<ConstantInt>(A0);
+ bool SecondIsConst = isa<ConstantInt>(A1);
+ // If both are const, then we don't need such a comparison.
+ if (FirstIsConst && SecondIsConst) continue;
+ // If only one is const, then make it the first callback argument.
+ if (FirstIsConst || SecondIsConst) {
+ CallbackFunc = SanCovTraceConstCmpFunction[CallbackIdx];
+ if (SecondIsConst)
+ std::swap(A0, A1);
+ }
+
+ auto Ty = Type::getIntNTy(*C, TypeSize);
+ IRB.CreateCall(CallbackFunc, {IRB.CreateIntCast(A0, Ty, true),
+ IRB.CreateIntCast(A1, Ty, true)});
+ }
+ }
+}
+
+void SanitizerCoverageModule::InjectCoverageAtBlock(Function &F, BasicBlock &BB,
+ size_t Idx,
+ bool IsLeafFunc) {
+ BasicBlock::iterator IP = BB.getFirstInsertionPt();
+ bool IsEntryBB = &BB == &F.getEntryBlock();
+ DebugLoc EntryLoc;
+ if (IsEntryBB) {
+ if (auto SP = F.getSubprogram())
+ EntryLoc = DebugLoc::get(SP->getScopeLine(), 0, SP);
+ // Keep static allocas and llvm.localescape calls in the entry block. Even
+ // if we aren't splitting the block, it's nice for allocas to be before
+ // calls.
+ IP = PrepareToSplitEntryBlock(BB, IP);
+ } else {
+ EntryLoc = IP->getDebugLoc();
+ }
+
+ IRBuilder<> IRB(&*IP);
+ IRB.SetCurrentDebugLocation(EntryLoc);
+ if (Options.TracePC) {
+ IRB.CreateCall(SanCovTracePC); // gets the PC using GET_CALLER_PC.
+ IRB.CreateCall(EmptyAsm, {}); // Avoids callback merge.
+ }
+ if (Options.TracePCGuard) {
+ auto GuardPtr = IRB.CreateIntToPtr(
+ IRB.CreateAdd(IRB.CreatePointerCast(FunctionGuardArray, IntptrTy),
+ ConstantInt::get(IntptrTy, Idx * 4)),
+ Int32PtrTy);
+ IRB.CreateCall(SanCovTracePCGuard, GuardPtr);
+ IRB.CreateCall(EmptyAsm, {}); // Avoids callback merge.
+ }
+ if (Options.Inline8bitCounters) {
+ auto CounterPtr = IRB.CreateGEP(
+ Function8bitCounterArray->getValueType(), Function8bitCounterArray,
+ {ConstantInt::get(IntptrTy, 0), ConstantInt::get(IntptrTy, Idx)});
+ auto Load = IRB.CreateLoad(Int8Ty, CounterPtr);
+ auto Inc = IRB.CreateAdd(Load, ConstantInt::get(Int8Ty, 1));
+ auto Store = IRB.CreateStore(Inc, CounterPtr);
+ SetNoSanitizeMetadata(Load);
+ SetNoSanitizeMetadata(Store);
+ }
+ if (Options.StackDepth && IsEntryBB && !IsLeafFunc) {
+ // Check stack depth. If it's the deepest so far, record it.
+ Function *GetFrameAddr =
+ Intrinsic::getDeclaration(F.getParent(), Intrinsic::frameaddress);
+ auto FrameAddrPtr =
+ IRB.CreateCall(GetFrameAddr, {Constant::getNullValue(Int32Ty)});
+ auto FrameAddrInt = IRB.CreatePtrToInt(FrameAddrPtr, IntptrTy);
+ auto LowestStack = IRB.CreateLoad(IntptrTy, SanCovLowestStack);
+ auto IsStackLower = IRB.CreateICmpULT(FrameAddrInt, LowestStack);
+ auto ThenTerm = SplitBlockAndInsertIfThen(IsStackLower, &*IP, false);
+ IRBuilder<> ThenIRB(ThenTerm);
+ auto Store = ThenIRB.CreateStore(FrameAddrInt, SanCovLowestStack);
+ SetNoSanitizeMetadata(LowestStack);
+ SetNoSanitizeMetadata(Store);
+ }
+}
+
+std::string
+SanitizerCoverageModule::getSectionName(const std::string &Section) const {
+ if (TargetTriple.isOSBinFormatCOFF()) {
+ if (Section == SanCovCountersSectionName)
+ return ".SCOV$CM";
+ if (Section == SanCovPCsSectionName)
+ return ".SCOVP$M";
+ return ".SCOV$GM"; // For SanCovGuardsSectionName.
+ }
+ if (TargetTriple.isOSBinFormatMachO())
+ return "__DATA,__" + Section;
+ return "__" + Section;
+}
+
+std::string
+SanitizerCoverageModule::getSectionStart(const std::string &Section) const {
+ if (TargetTriple.isOSBinFormatMachO())
+ return "\1section$start$__DATA$__" + Section;
+ return "__start___" + Section;
+}
+
+std::string
+SanitizerCoverageModule::getSectionEnd(const std::string &Section) const {
+ if (TargetTriple.isOSBinFormatMachO())
+ return "\1section$end$__DATA$__" + Section;
+ return "__stop___" + Section;
+}
+
+
+char SanitizerCoverageModule::ID = 0;
+INITIALIZE_PASS_BEGIN(SanitizerCoverageModule, "sancov",
+ "SanitizerCoverage: TODO."
+ "ModulePass",
+ false, false)
+INITIALIZE_PASS_DEPENDENCY(DominatorTreeWrapperPass)
+INITIALIZE_PASS_DEPENDENCY(PostDominatorTreeWrapperPass)
+INITIALIZE_PASS_END(SanitizerCoverageModule, "sancov",
+ "SanitizerCoverage: TODO."
+ "ModulePass",
+ false, false)
+ModulePass *llvm::createSanitizerCoverageModulePass(
+ const SanitizerCoverageOptions &Options) {
+ return new SanitizerCoverageModule(Options);
+}
generated by cgit v1.2.3 (git 2.25.1) at 2025-12-08 02:55:54 +0000