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-rw-r--r--GNUmakefile.llvm5
-rw-r--r--docs/Changelog.md3
-rw-r--r--instrumentation/SanitizerCoveragePCGUARD.so.cc1331
-rw-r--r--src/afl-cc.c15
4 files changed, 1351 insertions, 3 deletions
diff --git a/GNUmakefile.llvm b/GNUmakefile.llvm
index 1f67ea7f..3605b425 100644
--- a/GNUmakefile.llvm
+++ b/GNUmakefile.llvm
@@ -297,7 +297,7 @@ ifeq "$(TEST_MMAP)" "1"
 endif
 
 PROGS_ALWAYS = ./afl-cc ./afl-compiler-rt.o ./afl-compiler-rt-32.o ./afl-compiler-rt-64.o 
-PROGS        = $(PROGS_ALWAYS) ./afl-llvm-pass.so ./split-compares-pass.so ./split-switches-pass.so ./cmplog-routines-pass.so ./cmplog-instructions-pass.so ./afl-llvm-dict2file.so ./compare-transform-pass.so ./libLLVMInsTrim.so ./afl-ld-lto ./afl-llvm-lto-instrumentlist.so ./afl-llvm-lto-instrumentation.so ./SanitizerCoverageLTO.so
+PROGS        = $(PROGS_ALWAYS) ./afl-llvm-pass.so ./SanitizerCoveragePCGUARD.so ./split-compares-pass.so ./split-switches-pass.so ./cmplog-routines-pass.so ./cmplog-instructions-pass.so ./afl-llvm-dict2file.so ./compare-transform-pass.so ./libLLVMInsTrim.so ./afl-ld-lto ./afl-llvm-lto-instrumentlist.so ./afl-llvm-lto-instrumentation.so ./SanitizerCoverageLTO.so
 
 # If prerequisites are not given, warn, do not build anything, and exit with code 0
 ifeq "$(LLVMVER)" ""
@@ -382,6 +382,9 @@ ifeq "$(LLVM_MIN_4_0_1)" "0"
 endif
 	$(CXX) $(CLANG_CPPFL) -DLLVMInsTrim_EXPORTS -fno-rtti -fPIC -std=$(LLVM_STDCXX) -shared $< -o $@ $(CLANG_LFL) instrumentation/afl-llvm-common.o
 
+./SanitizerCoveragePCGUARD.so: instrumentation/SanitizerCoveragePCGUARD.so.cc instrumentation/afl-llvm-common.o | test_deps
+	$(CXX) $(CLANG_CPPFL) -fno-rtti -fPIC -std=$(LLVM_STDCXX) -shared $< -o $@ $(CLANG_LFL) instrumentation/afl-llvm-common.o
+
 ./afl-llvm-lto-instrumentlist.so: instrumentation/afl-llvm-lto-instrumentlist.so.cc instrumentation/afl-llvm-common.o
 ifeq "$(LLVM_LTO)" "1"
 	$(CXX) $(CLANG_CPPFL) -fno-rtti -fPIC -std=$(LLVM_STDCXX) -shared $< -o $@ $(CLANG_LFL) instrumentation/afl-llvm-common.o
diff --git a/docs/Changelog.md b/docs/Changelog.md
index f8f15fc8..798a056f 100644
--- a/docs/Changelog.md
+++ b/docs/Changelog.md
@@ -40,6 +40,9 @@ sending a mail to <afl-users+subscribe@googlegroups.com>.
     - We received an enhanced gcc_plugin module from AdaCore, thank you
       very much!!
     - not overriding -Ox or -fno-unroll-loops anymore
+    - we now have our own trace-pc-guard implementation. It is the same as
+      -fsanitize-coverage=trace-pc-guard from llvm 12, but: it is a) inline
+      and b) works from llvm 10+ on :)
     - new llvm pass: dict2file via AFL_LLVM_DICT2FILE, create afl-fuzz
       -x dictionary of string comparisons found during compilation
     - LTO autodict now also collects interesting cmp comparisons,
diff --git a/instrumentation/SanitizerCoveragePCGUARD.so.cc b/instrumentation/SanitizerCoveragePCGUARD.so.cc
new file mode 100644
index 00000000..97e8d32b
--- /dev/null
+++ b/instrumentation/SanitizerCoveragePCGUARD.so.cc
@@ -0,0 +1,1331 @@
+//===-- 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/IR/Module.h"
+#include "llvm/IR/PassManager.h"
+#include "llvm/Support/SpecialCaseList.h"
+#include "llvm/Support/VirtualFileSystem.h"
+#include "llvm/Transforms/Instrumentation.h"
+#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/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/InitializePasses.h"
+#include "llvm/Support/CommandLine.h"
+#include "llvm/Support/Debug.h"
+#include "llvm/Support/SpecialCaseList.h"
+#include "llvm/Support/VirtualFileSystem.h"
+#include "llvm/Support/raw_ostream.h"
+#include "llvm/Transforms/Instrumentation.h"
+#include "llvm/Transforms/Utils/BasicBlockUtils.h"
+#include "llvm/Transforms/Utils/ModuleUtils.h"
+
+#include "config.h"
+#include "debug.h"
+#include "afl-llvm-common.h"
+
+namespace llvm {
+
+/// This is the ModuleSanitizerCoverage pass used in the new pass manager. The
+/// pass instruments functions for coverage, adds initialization calls to the
+/// module for trace PC guards and 8bit counters if they are requested, and
+/// appends globals to llvm.compiler.used.
+class ModuleSanitizerCoveragePass
+    : public PassInfoMixin<ModuleSanitizerCoveragePass> {
+
+ public:
+  explicit ModuleSanitizerCoveragePass(
+      SanitizerCoverageOptions        Options = SanitizerCoverageOptions(),
+      const std::vector<std::string> &AllowlistFiles =
+          std::vector<std::string>(),
+      const std::vector<std::string> &BlocklistFiles =
+          std::vector<std::string>())
+      : Options(Options) {
+
+    if (AllowlistFiles.size() > 0)
+      Allowlist = SpecialCaseList::createOrDie(AllowlistFiles,
+                                               *vfs::getRealFileSystem());
+    if (BlocklistFiles.size() > 0)
+      Blocklist = SpecialCaseList::createOrDie(BlocklistFiles,
+                                               *vfs::getRealFileSystem());
+
+  }
+
+  PreservedAnalyses run(Module &M, ModuleAnalysisManager &AM);
+  static bool       isRequired() {
+
+    return true;
+
+  }
+
+ private:
+  SanitizerCoverageOptions Options;
+
+  std::unique_ptr<SpecialCaseList> Allowlist;
+  std::unique_ptr<SpecialCaseList> Blocklist;
+
+};
+
+// Insert SanitizerCoverage instrumentation.
+ModulePass *createModuleSanitizerCoverageLegacyPassPass(
+    const SanitizerCoverageOptions &Options = SanitizerCoverageOptions(),
+    const std::vector<std::string> &AllowlistFiles = std::vector<std::string>(),
+    const std::vector<std::string> &BlocklistFiles =
+        std::vector<std::string>());
+
+}  // namespace llvm
+
+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 char *const SanCovModuleCtorBoolFlagName =
+    "sancov.module_ctor_bool_flag";
+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 SanCovBoolFlagInitName =
+    "__sanitizer_cov_bool_flag_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 SanCovBoolFlagSectionName = "sancov_bools";
+static const char *const SanCovPCsSectionName = "sancov_pcs";
+
+static const char *const SanCovLowestStackName = "__sancov_lowest_stack";
+
+static char *skip_nozero;
+
+/*
+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(3));
+
+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(true));
+
+// 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, inline-8bit-counters, and
+// inline-bool-flag.
+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> ClInlineBoolFlag(
+    "sanitizer-coverage-inline-bool-flag",
+    cl::desc("sets a boolean flag 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 =
+      SanitizerCoverageOptions::SCK_Edge;  // std::max(Options.CoverageType,
+                                           // CLOpts.CoverageType);
+  Options.IndirectCalls = true;    // CLOpts.IndirectCalls;
+  Options.TraceCmp = false;        //|= ClCMPTracing;
+  Options.TraceDiv = false;        //|= ClDIVTracing;
+  Options.TraceGep = false;        //|= ClGEPTracing;
+  Options.TracePC = false;         //|= ClTracePC;
+  Options.TracePCGuard = true;     // |= ClTracePCGuard;
+  Options.Inline8bitCounters = 0;  //|= ClInline8bitCounters;
+  // Options.InlineBoolFlag = 0; //|= ClInlineBoolFlag;
+  Options.PCTable = false;     //|= ClCreatePCTable;
+  Options.NoPrune = false;     //|= !ClPruneBlocks;
+  Options.StackDepth = false;  //|= ClStackDepth;
+  if (!Options.TracePCGuard && !Options.TracePC &&
+      !Options.Inline8bitCounters && !Options.StackDepth /*&&
+      !Options.InlineBoolFlag*/)
+    Options.TracePCGuard = true;  // TracePCGuard is default.
+
+  return Options;
+
+}
+
+using DomTreeCallback = function_ref<const DominatorTree *(Function &F)>;
+using PostDomTreeCallback =
+    function_ref<const PostDominatorTree *(Function &F)>;
+
+class ModuleSanitizerCoverage {
+
+ public:
+  ModuleSanitizerCoverage(
+      const SanitizerCoverageOptions &Options = SanitizerCoverageOptions(),
+      const SpecialCaseList *         Allowlist = nullptr,
+      const SpecialCaseList *         Blocklist = nullptr)
+      : Options(OverrideFromCL(Options)),
+        Allowlist(Allowlist),
+        Blocklist(Blocklist) {
+
+  }
+
+  bool instrumentModule(Module &M, DomTreeCallback DTCallback,
+                        PostDomTreeCallback PDTCallback);
+
+ private:
+  void instrumentFunction(Function &F, DomTreeCallback DTCallback,
+                          PostDomTreeCallback PDTCallback);
+  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;
+  Type *IntptrTy, *IntptrPtrTy, *Int64Ty, *Int64PtrTy, *Int32Ty, *Int32PtrTy,
+      *Int16Ty, *Int8Ty, *Int8PtrTy, *Int1Ty, *Int1PtrTy;
+  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 *FunctionBoolArray;         // for inline-bool-flag.
+  GlobalVariable *FunctionPCsArray;          // for pc-table.
+  SmallVector<GlobalValue *, 20> GlobalsToAppendToUsed;
+  SmallVector<GlobalValue *, 20> GlobalsToAppendToCompilerUsed;
+
+  SanitizerCoverageOptions Options;
+
+  const SpecialCaseList *Allowlist;
+  const SpecialCaseList *Blocklist;
+
+  uint32_t        instr = 0;
+  GlobalVariable *AFLMapPtr = NULL;
+  ConstantInt *   One = NULL;
+  ConstantInt *   Zero = NULL;
+
+};
+
+class ModuleSanitizerCoverageLegacyPass : public ModulePass {
+
+ public:
+  ModuleSanitizerCoverageLegacyPass(
+      const SanitizerCoverageOptions &Options = SanitizerCoverageOptions(),
+      const std::vector<std::string> &AllowlistFiles =
+          std::vector<std::string>(),
+      const std::vector<std::string> &BlocklistFiles =
+          std::vector<std::string>())
+      : ModulePass(ID), Options(Options) {
+
+    if (AllowlistFiles.size() > 0)
+      Allowlist = SpecialCaseList::createOrDie(AllowlistFiles,
+                                               *vfs::getRealFileSystem());
+    if (BlocklistFiles.size() > 0)
+      Blocklist = SpecialCaseList::createOrDie(BlocklistFiles,
+                                               *vfs::getRealFileSystem());
+    initializeModuleSanitizerCoverageLegacyPassPass(
+        *PassRegistry::getPassRegistry());
+
+  }
+
+  bool runOnModule(Module &M) override {
+
+    ModuleSanitizerCoverage ModuleSancov(Options, Allowlist.get(),
+                                         Blocklist.get());
+    auto DTCallback = [this](Function &F) -> const DominatorTree * {
+
+      return &this->getAnalysis<DominatorTreeWrapperPass>(F).getDomTree();
+
+    };
+
+    auto PDTCallback = [this](Function &F) -> const PostDominatorTree * {
+
+      return &this->getAnalysis<PostDominatorTreeWrapperPass>(F)
+                  .getPostDomTree();
+
+    };
+
+    return ModuleSancov.instrumentModule(M, DTCallback, PDTCallback);
+
+  }
+
+  static char ID;  // Pass identification, replacement for typeid
+  StringRef   getPassName() const override {
+
+    return "ModuleSanitizerCoverage";
+
+  }
+
+  void getAnalysisUsage(AnalysisUsage &AU) const override {
+
+    AU.addRequired<DominatorTreeWrapperPass>();
+    AU.addRequired<PostDominatorTreeWrapperPass>();
+
+  }
+
+ private:
+  SanitizerCoverageOptions Options;
+
+  std::unique_ptr<SpecialCaseList> Allowlist;
+  std::unique_ptr<SpecialCaseList> Blocklist;
+
+};
+
+}  // namespace
+
+PreservedAnalyses ModuleSanitizerCoveragePass::run(Module &               M,
+                                                   ModuleAnalysisManager &MAM) {
+
+  ModuleSanitizerCoverage ModuleSancov(Options, Allowlist.get(),
+                                       Blocklist.get());
+  auto &FAM = MAM.getResult<FunctionAnalysisManagerModuleProxy>(M).getManager();
+  auto  DTCallback = [&FAM](Function &F) -> const DominatorTree * {
+
+    return &FAM.getResult<DominatorTreeAnalysis>(F);
+
+  };
+
+  auto PDTCallback = [&FAM](Function &F) -> const PostDominatorTree * {
+
+    return &FAM.getResult<PostDominatorTreeAnalysis>(F);
+
+  };
+
+  if (ModuleSancov.instrumentModule(M, DTCallback, PDTCallback))
+    return PreservedAnalyses::none();
+  return PreservedAnalyses::all();
+
+}
+
+std::pair<Value *, Value *> ModuleSanitizerCoverage::CreateSecStartEnd(
+    Module &M, const char *Section, Type *Ty) {
+
+  GlobalVariable *SecStart = new GlobalVariable(
+      M, Ty->getPointerElementType(), false, GlobalVariable::ExternalLinkage,
+      nullptr, getSectionStart(Section));
+  SecStart->setVisibility(GlobalValue::HiddenVisibility);
+  GlobalVariable *SecEnd = new GlobalVariable(
+      M, Ty->getPointerElementType(), false, GlobalVariable::ExternalLinkage,
+      nullptr, getSectionEnd(Section));
+  SecEnd->setVisibility(GlobalValue::HiddenVisibility);
+  IRBuilder<> IRB(M.getContext());
+  if (!TargetTriple.isOSBinFormatCOFF())
+    return std::make_pair(SecStart, SecEnd);
+
+  // 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), SecEnd);
+
+}
+
+Function *ModuleSanitizerCoverage::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 ModuleSanitizerCoverage::instrumentModule(
+    Module &M, DomTreeCallback DTCallback, PostDomTreeCallback PDTCallback) {
+
+  setvbuf(stdout, NULL, _IONBF, 0);
+  if (getenv("AFL_DEBUG")) debug = 1;
+
+  if ((isatty(2) && !getenv("AFL_QUIET")) || debug) {
+
+    SAYF(cCYA "SanitizerCoveragePCGUARD" VERSION cRST "\n");
+
+  } else
+
+    be_quiet = 1;
+
+  skip_nozero = getenv("AFL_LLVM_SKIP_NEVERZERO");
+  // scanForDangerousFunctions(&M);
+
+  if (debug) {
+
+    fprintf(stderr,
+            "SANCOV: covtype:%u indirect:%d stack:%d noprune:%d "
+            "createtable:%d tracepcguard:%d tracepc:%d\n",
+            Options.CoverageType, Options.IndirectCalls == true ? 1 : 0,
+            Options.StackDepth == true ? 1 : 0, Options.NoPrune == true ? 1 : 0,
+            // Options.InlineBoolFlag == true ? 1 : 0,
+            Options.PCTable == true ? 1 : 0,
+            Options.TracePCGuard == true ? 1 : 0,
+            Options.TracePC == true ? 1 : 0);
+
+  }
+
+  if (Options.CoverageType == SanitizerCoverageOptions::SCK_None) return false;
+  if (Allowlist &&
+      !Allowlist->inSection("coverage", "src", M.getSourceFileName()))
+    return false;
+  if (Blocklist &&
+      Blocklist->inSection("coverage", "src", M.getSourceFileName()))
+    return false;
+  C = &(M.getContext());
+  DL = &M.getDataLayout();
+  CurModule = &M;
+  CurModuleUniqueId = getUniqueModuleId(CurModule);
+  TargetTriple = Triple(M.getTargetTriple());
+  FunctionGuardArray = nullptr;
+  Function8bitCounterArray = nullptr;
+  FunctionBoolArray = 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());
+  Int1PtrTy = PointerType::getUnqual(IRB.getInt1Ty());
+  Int64Ty = IRB.getInt64Ty();
+  Int32Ty = IRB.getInt32Ty();
+  Int16Ty = IRB.getInt16Ty();
+  Int8Ty = IRB.getInt8Ty();
+  Int1Ty = IRB.getInt1Ty();
+  LLVMContext &Ctx = M.getContext();
+
+  AFLMapPtr =
+      new GlobalVariable(M, PointerType::get(Int8Ty, 0), false,
+                         GlobalValue::ExternalLinkage, 0, "__afl_area_ptr");
+  One = ConstantInt::get(IntegerType::getInt8Ty(Ctx), 1);
+  Zero = ConstantInt::get(IntegerType::getInt8Ty(Ctx), 0);
+
+  SanCovTracePCIndir =
+      M.getOrInsertFunction(SanCovTracePCIndirName, VoidTy, IntptrTy);
+  // Make sure smaller parameters are zero-extended to i64 if required by the
+  // target ABI.
+  AttributeList SanCovTraceCmpZeroExtAL;
+  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;
+    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));
+
+  SanCovTracePC = M.getOrInsertFunction(SanCovTracePCName, VoidTy);
+  SanCovTracePCGuard =
+      M.getOrInsertFunction(SanCovTracePCGuardName, VoidTy, Int32PtrTy);
+
+  for (auto &F : M)
+    instrumentFunction(F, DTCallback, PDTCallback);
+
+  Function *Ctor = nullptr;
+
+  if (FunctionGuardArray)
+    Ctor = CreateInitCallsForSections(M, SanCovModuleCtorTracePcGuardName,
+                                      SanCovTracePCGuardInitName, Int32PtrTy,
+                                      SanCovGuardsSectionName);
+  if (Function8bitCounterArray)
+    Ctor = CreateInitCallsForSections(M, SanCovModuleCtor8bitCountersName,
+                                      SanCov8bitCountersInitName, Int8PtrTy,
+                                      SanCovCountersSectionName);
+  if (FunctionBoolArray) {
+
+    Ctor = CreateInitCallsForSections(M, SanCovModuleCtorBoolFlagName,
+                                      SanCovBoolFlagInitName, Int1PtrTy,
+                                      SanCovBoolFlagSectionName);
+
+  }
+
+  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);
+
+  if (!be_quiet) {
+
+    if (!instr)
+      WARNF("No instrumentation targets found.");
+    else {
+
+      char modeline[100];
+      snprintf(modeline, sizeof(modeline), "%s%s%s%s%s",
+               getenv("AFL_HARDEN") ? "hardened" : "non-hardened",
+               getenv("AFL_USE_ASAN") ? ", ASAN" : "",
+               getenv("AFL_USE_MSAN") ? ", MSAN" : "",
+               getenv("AFL_USE_CFISAN") ? ", CFISAN" : "",
+               getenv("AFL_USE_UBSAN") ? ", UBSAN" : "");
+      OKF("Instrumented %u locations with no collisions (%s mode).", instr,
+          modeline);
+
+    }
+
+  }
+
+  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;
+
+}
+
+void ModuleSanitizerCoverage::instrumentFunction(
+    Function &F, DomTreeCallback DTCallback, PostDomTreeCallback PDTCallback) {
+
+  if (F.empty()) return;
+  if (F.getName().find(".module_ctor") != std::string::npos)
+    return;  // Should not instrument sanitizer init functions.
+  if (F.getName().startswith("__sanitizer_"))
+    return;  // Don't instrument __sanitizer_* callbacks.
+  // Don't touch available_externally functions, their actual body is elewhere.
+  if (F.getLinkage() == GlobalValue::AvailableExternallyLinkage) return;
+  // 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;
+  if (isa<UnreachableInst>(F.getEntryBlock().getTerminator())) return;
+  // 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;
+  if (Allowlist && !Allowlist->inSection("coverage", "fun", F.getName()))
+    return;
+  if (Blocklist && Blocklist->inSection("coverage", "fun", F.getName())) return;
+  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 = DTCallback(F);
+  const PostDominatorTree *PDT = PDTCallback(F);
+  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) {
+
+        CallBase *CB = dyn_cast<CallBase>(&Inst);
+        if (CB && !CB->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);
+
+}
+
+GlobalVariable *ModuleSanitizerCoverage::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(Align(DL->getTypeStoreSize(Ty).getFixedSize()));
+  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 *ModuleSanitizerCoverage::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 ModuleSanitizerCoverage::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.InlineBoolFlag)
+      FunctionBoolArray = CreateFunctionLocalArrayInSection(
+          AllBlocks.size(), F, Int1Ty, SanCovBoolFlagSectionName);
+  */
+  if (Options.PCTable) FunctionPCsArray = CreatePCArray(F, AllBlocks);
+
+}
+
+bool ModuleSanitizerCoverage::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 ModuleSanitizerCoverage::InjectCoverageForIndirectCalls(
+    Function &F, ArrayRef<Instruction *> IndirCalls) {
+
+  if (IndirCalls.empty()) return;
+  assert(Options.TracePC || Options.TracePCGuard ||
+         Options.Inline8bitCounters /*|| Options.InlineBoolFlag*/);
+  for (auto I : IndirCalls) {
+
+    IRBuilder<> IRB(I);
+    CallBase &  CB = cast<CallBase>(*I);
+    Value *     Callee = CB.getCalledOperand();
+    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 ModuleSanitizerCoverage::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 ModuleSanitizerCoverage::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 ModuleSanitizerCoverage::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 ModuleSanitizerCoverage::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 ModuleSanitizerCoverage::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);
+    //        ->setCannotMerge();  // gets the PC using GET_CALLER_PC.
+
+  }
+
+  if (Options.TracePCGuard) {
+
+    /* Get CurLoc */
+
+    Value *GuardPtr = IRB.CreateIntToPtr(
+        IRB.CreateAdd(IRB.CreatePointerCast(FunctionGuardArray, IntptrTy),
+                      ConstantInt::get(IntptrTy, Idx * 4)),
+        Int32PtrTy);
+
+    LoadInst *CurLoc = IRB.CreateLoad(GuardPtr);
+
+    /* Load SHM pointer */
+
+    LoadInst *MapPtr = IRB.CreateLoad(AFLMapPtr);
+
+    /* Load counter for CurLoc */
+
+    Value *   MapPtrIdx = IRB.CreateGEP(MapPtr, CurLoc);
+    LoadInst *Counter = IRB.CreateLoad(MapPtrIdx);
+
+    /* Update bitmap */
+
+    Value *Incr = IRB.CreateAdd(Counter, One);
+
+    if (skip_nozero == NULL) {
+
+      auto cf = IRB.CreateICmpEQ(Incr, Zero);
+      auto carry = IRB.CreateZExt(cf, Int8Ty);
+      Incr = IRB.CreateAdd(Incr, carry);
+
+    }
+
+    IRB.CreateStore(Incr, MapPtrIdx);
+
+    // done :)
+
+    //    IRB.CreateCall(SanCovTracePCGuard, Offset)->setCannotMerge();
+    //    IRB.CreateCall(SanCovTracePCGuard, GuardPtr)->setCannotMerge();
+    ++instr;
+
+  }
+
+  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.InlineBoolFlag) {
+
+      auto FlagPtr = IRB.CreateGEP(
+          FunctionBoolArray->getValueType(), FunctionBoolArray,
+          {ConstantInt::get(IntptrTy, 0), ConstantInt::get(IntptrTy, Idx)});
+      auto Load = IRB.CreateLoad(Int1Ty, FlagPtr);
+      auto ThenTerm =
+          SplitBlockAndInsertIfThen(IRB.CreateIsNull(Load), &*IP, false);
+      IRBuilder<> ThenIRB(ThenTerm);
+      auto Store = ThenIRB.CreateStore(ConstantInt::getTrue(Int1Ty), FlagPtr);
+      SetNoSanitizeMetadata(Load);
+      SetNoSanitizeMetadata(Store);
+
+    }
+
+  */
+
+  if (Options.StackDepth && IsEntryBB && !IsLeafFunc) {
+
+    // Check stack depth.  If it's the deepest so far, record it.
+    Module *  M = F.getParent();
+    Function *GetFrameAddr = Intrinsic::getDeclaration(
+        M, Intrinsic::frameaddress,
+        IRB.getInt8PtrTy(M->getDataLayout().getAllocaAddrSpace()));
+    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 ModuleSanitizerCoverage::getSectionName(
+    const std::string &Section) const {
+
+  if (TargetTriple.isOSBinFormatCOFF()) {
+
+    if (Section == SanCovCountersSectionName) return ".SCOV$CM";
+    if (Section == SanCovBoolFlagSectionName) return ".SCOV$BM";
+    if (Section == SanCovPCsSectionName) return ".SCOVP$M";
+    return ".SCOV$GM";  // For SanCovGuardsSectionName.
+
+  }
+
+  if (TargetTriple.isOSBinFormatMachO()) return "__DATA,__" + Section;
+  return "__" + Section;
+
+}
+
+std::string ModuleSanitizerCoverage::getSectionStart(
+    const std::string &Section) const {
+
+  if (TargetTriple.isOSBinFormatMachO())
+    return "\1section$start$__DATA$__" + Section;
+  return "__start___" + Section;
+
+}
+
+std::string ModuleSanitizerCoverage::getSectionEnd(
+    const std::string &Section) const {
+
+  if (TargetTriple.isOSBinFormatMachO())
+    return "\1section$end$__DATA$__" + Section;
+  return "__stop___" + Section;
+
+}
+
+char ModuleSanitizerCoverageLegacyPass::ID = 0;
+INITIALIZE_PASS_BEGIN(ModuleSanitizerCoverageLegacyPass, "sancov",
+                      "Pass for instrumenting coverage on functions", false,
+                      false)
+INITIALIZE_PASS_DEPENDENCY(DominatorTreeWrapperPass)
+INITIALIZE_PASS_DEPENDENCY(PostDominatorTreeWrapperPass)
+INITIALIZE_PASS_END(ModuleSanitizerCoverageLegacyPass, "sancov",
+                    "Pass for instrumenting coverage on functions", false,
+                    false)
+ModulePass *llvm::createModuleSanitizerCoverageLegacyPassPass(
+    const SanitizerCoverageOptions &Options,
+    const std::vector<std::string> &AllowlistFiles,
+    const std::vector<std::string> &BlocklistFiles) {
+
+  return new ModuleSanitizerCoverageLegacyPass(Options, AllowlistFiles,
+                                               BlocklistFiles);
+
+}
+
+static void registerPCGUARDPass(const PassManagerBuilder &,
+                                legacy::PassManagerBase &PM) {
+
+  auto p = new ModuleSanitizerCoverageLegacyPass();
+  PM.add(p);
+
+}
+
+static RegisterStandardPasses RegisterCompTransPass(
+    PassManagerBuilder::EP_OptimizerLast, registerPCGUARDPass);
+
+static RegisterStandardPasses RegisterCompTransPass0(
+    PassManagerBuilder::EP_EnabledOnOptLevel0, registerPCGUARDPass);
+
diff --git a/src/afl-cc.c b/src/afl-cc.c
index c516dc4c..1a7a837f 100644
--- a/src/afl-cc.c
+++ b/src/afl-cc.c
@@ -501,11 +501,22 @@ static void edit_params(u32 argc, char **argv, char **envp) {
 
       if (instrument_mode == INSTRUMENT_PCGUARD) {
 
-#if LLVM_MAJOR >= 4
+#if LLVM_MAJOR >= 10
+        cc_params[cc_par_cnt++] = "-Xclang";
+        cc_params[cc_par_cnt++] = "-load";
+        cc_params[cc_par_cnt++] = "-Xclang";
         cc_params[cc_par_cnt++] =
-            "-fsanitize-coverage=trace-pc-guard";  // edge coverage by default
+            alloc_printf("%s/SanitizerCoveragePCGUARD.so", obj_path);
 #else
+  #if LLVM_MAJOR >= 4
+        if (!be_quiet)
+          SAYF(
+              "Using unoptimized trace-pc-guard, upgrade to llvm 10+ for "
+              "enhanced version.\n");
+        cc_params[cc_par_cnt++] = "-fsanitize-coverage=trace-pc-guard";
+  #else
         FATAL("pcguard instrumentation requires llvm 4.0.1+");
+  #endif
 #endif
 
       } else {