Adding upstream version 115.7.0esr.upstream/115.7.0esr

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 657 insertions, 0 deletions

diff --git a/tools/fuzzing/libfuzzer/FuzzerTracePC.cpp b/tools/fuzzing/libfuzzer/FuzzerTracePC.cpp
new file mode 100644
index 0000000000..fbceda39bc
--- /dev/null
+++ b/tools/fuzzing/libfuzzer/FuzzerTracePC.cpp
@@ -0,0 +1,657 @@
+//===- FuzzerTracePC.cpp - PC tracing--------------------------------------===//
+//
+// 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
+//
+//===----------------------------------------------------------------------===//
+// Trace PCs.
+// This module implements __sanitizer_cov_trace_pc_guard[_init],
+// the callback required for -fsanitize-coverage=trace-pc-guard instrumentation.
+//
+//===----------------------------------------------------------------------===//
+
+#include "FuzzerTracePC.h"
+#include "FuzzerBuiltins.h"
+#include "FuzzerBuiltinsMsvc.h"
+#include "FuzzerCorpus.h"
+#include "FuzzerDefs.h"
+#include "FuzzerDictionary.h"
+#include "FuzzerExtFunctions.h"
+#include "FuzzerIO.h"
+#include "FuzzerPlatform.h"
+#include "FuzzerUtil.h"
+#include "FuzzerValueBitMap.h"
+#include <set>
+
+// Used by -fsanitize-coverage=stack-depth to track stack depth
+ATTRIBUTES_INTERFACE_TLS_INITIAL_EXEC uintptr_t __sancov_lowest_stack;
+
+namespace fuzzer {
+
+TracePC TPC;
+
+size_t TracePC::GetTotalPCCoverage() {
+  return ObservedPCs.size();
+}
+
+
+void TracePC::HandleInline8bitCountersInit(uint8_t *Start, uint8_t *Stop) {
+  if (Start == Stop) return;
+  if (NumModules &&
+      Modules[NumModules - 1].Start() == Start)
+    return;
+  assert(NumModules <
+         sizeof(Modules) / sizeof(Modules[0]));
+  auto &M = Modules[NumModules++];
+  uint8_t *AlignedStart = RoundUpByPage(Start);
+  uint8_t *AlignedStop  = RoundDownByPage(Stop);
+  size_t NumFullPages = AlignedStop > AlignedStart ?
+                        (AlignedStop - AlignedStart) / PageSize() : 0;
+  bool NeedFirst = Start < AlignedStart || !NumFullPages;
+  bool NeedLast  = Stop > AlignedStop && AlignedStop >= AlignedStart;
+  M.NumRegions = NumFullPages + NeedFirst + NeedLast;;
+  assert(M.NumRegions > 0);
+  M.Regions = new Module::Region[M.NumRegions];
+  assert(M.Regions);
+  size_t R = 0;
+  if (NeedFirst)
+    M.Regions[R++] = {Start, std::min(Stop, AlignedStart), true, false};
+  for (uint8_t *P = AlignedStart; P < AlignedStop; P += PageSize())
+    M.Regions[R++] = {P, P + PageSize(), true, true};
+  if (NeedLast)
+    M.Regions[R++] = {AlignedStop, Stop, true, false};
+  assert(R == M.NumRegions);
+  assert(M.Size() == (size_t)(Stop - Start));
+  assert(M.Stop() == Stop);
+  assert(M.Start() == Start);
+  NumInline8bitCounters += M.Size();
+}
+
+void TracePC::HandlePCsInit(const uintptr_t *Start, const uintptr_t *Stop) {
+  const PCTableEntry *B = reinterpret_cast<const PCTableEntry *>(Start);
+  const PCTableEntry *E = reinterpret_cast<const PCTableEntry *>(Stop);
+  if (NumPCTables && ModulePCTable[NumPCTables - 1].Start == B) return;
+  assert(NumPCTables < sizeof(ModulePCTable) / sizeof(ModulePCTable[0]));
+  ModulePCTable[NumPCTables++] = {B, E};
+  NumPCsInPCTables += E - B;
+}
+
+void TracePC::PrintModuleInfo() {
+  if (NumModules) {
+    Printf("INFO: Loaded %zd modules   (%zd inline 8-bit counters): ",
+           NumModules, NumInline8bitCounters);
+    for (size_t i = 0; i < NumModules; i++)
+      Printf("%zd [%p, %p), ", Modules[i].Size(), Modules[i].Start(),
+             Modules[i].Stop());
+    Printf("\n");
+  }
+  if (NumPCTables) {
+    Printf("INFO: Loaded %zd PC tables (%zd PCs): ", NumPCTables,
+           NumPCsInPCTables);
+    for (size_t i = 0; i < NumPCTables; i++) {
+      Printf("%zd [%p,%p), ", ModulePCTable[i].Stop - ModulePCTable[i].Start,
+             ModulePCTable[i].Start, ModulePCTable[i].Stop);
+    }
+    Printf("\n");
+
+    if (NumInline8bitCounters && NumInline8bitCounters != NumPCsInPCTables) {
+      Printf("ERROR: The size of coverage PC tables does not match the\n"
+             "number of instrumented PCs. This might be a compiler bug,\n"
+             "please contact the libFuzzer developers.\n"
+             "Also check https://bugs.llvm.org/show_bug.cgi?id=34636\n"
+             "for possible workarounds (tl;dr: don't use the old GNU ld)\n");
+      _Exit(1);
+    }
+  }
+  if (size_t NumExtraCounters = ExtraCountersEnd() - ExtraCountersBegin())
+    Printf("INFO: %zd Extra Counters\n", NumExtraCounters);
+}
+
+ATTRIBUTE_NO_SANITIZE_ALL
+void TracePC::HandleCallerCallee(uintptr_t Caller, uintptr_t Callee) {
+  const uintptr_t kBits = 12;
+  const uintptr_t kMask = (1 << kBits) - 1;
+  uintptr_t Idx = (Caller & kMask) | ((Callee & kMask) << kBits);
+  ValueProfileMap.AddValueModPrime(Idx);
+}
+
+/// \return the address of the previous instruction.
+/// Note: the logic is copied from `sanitizer_common/sanitizer_stacktrace.h`
+inline ALWAYS_INLINE uintptr_t GetPreviousInstructionPc(uintptr_t PC) {
+#if defined(__arm__)
+  // T32 (Thumb) branch instructions might be 16 or 32 bit long,
+  // so we return (pc-2) in that case in order to be safe.
+  // For A32 mode we return (pc-4) because all instructions are 32 bit long.
+  return (PC - 3) & (~1);
+#elif defined(__powerpc__) || defined(__powerpc64__) || defined(__aarch64__)
+  // PCs are always 4 byte aligned.
+  return PC - 4;
+#elif defined(__sparc__) || defined(__mips__)
+  return PC - 8;
+#else
+  return PC - 1;
+#endif
+}
+
+/// \return the address of the next instruction.
+/// Note: the logic is copied from `sanitizer_common/sanitizer_stacktrace.cpp`
+ALWAYS_INLINE uintptr_t TracePC::GetNextInstructionPc(uintptr_t PC) {
+#if defined(__mips__)
+  return PC + 8;
+#elif defined(__powerpc__) || defined(__sparc__) || defined(__arm__) || \
+    defined(__aarch64__)
+  return PC + 4;
+#else
+  return PC + 1;
+#endif
+}
+
+void TracePC::UpdateObservedPCs() {
+  Vector<uintptr_t> CoveredFuncs;
+  auto ObservePC = [&](const PCTableEntry *TE) {
+    if (ObservedPCs.insert(TE).second && DoPrintNewPCs) {
+      PrintPC("\tNEW_PC: %p %F %L", "\tNEW_PC: %p",
+              GetNextInstructionPc(TE->PC));
+      Printf("\n");
+    }
+  };
+
+  auto Observe = [&](const PCTableEntry *TE) {
+    if (PcIsFuncEntry(TE))
+      if (++ObservedFuncs[TE->PC] == 1 && NumPrintNewFuncs)
+        CoveredFuncs.push_back(TE->PC);
+    ObservePC(TE);
+  };
+
+  if (NumPCsInPCTables) {
+    if (NumInline8bitCounters == NumPCsInPCTables) {
+      for (size_t i = 0; i < NumModules; i++) {
+        auto &M = Modules[i];
+        assert(M.Size() ==
+               (size_t)(ModulePCTable[i].Stop - ModulePCTable[i].Start));
+        for (size_t r = 0; r < M.NumRegions; r++) {
+          auto &R = M.Regions[r];
+          if (!R.Enabled) continue;
+          for (uint8_t *P = R.Start; P < R.Stop; P++)
+            if (*P)
+              Observe(&ModulePCTable[i].Start[M.Idx(P)]);
+        }
+      }
+    }
+  }
+
+  for (size_t i = 0, N = Min(CoveredFuncs.size(), NumPrintNewFuncs); i < N;
+       i++) {
+    Printf("\tNEW_FUNC[%zd/%zd]: ", i + 1, CoveredFuncs.size());
+    PrintPC("%p %F %L", "%p", GetNextInstructionPc(CoveredFuncs[i]));
+    Printf("\n");
+  }
+}
+
+uintptr_t TracePC::PCTableEntryIdx(const PCTableEntry *TE) {
+  size_t TotalTEs = 0;
+  for (size_t i = 0; i < NumPCTables; i++) {
+    auto &M = ModulePCTable[i];
+    if (TE >= M.Start && TE < M.Stop)
+      return TotalTEs + TE - M.Start;
+    TotalTEs += M.Stop - M.Start;
+  }
+  assert(0);
+  return 0;
+}
+
+const TracePC::PCTableEntry *TracePC::PCTableEntryByIdx(uintptr_t Idx) {
+  for (size_t i = 0; i < NumPCTables; i++) {
+    auto &M = ModulePCTable[i];
+    size_t Size = M.Stop - M.Start;
+    if (Idx < Size) return &M.Start[Idx];
+    Idx -= Size;
+  }
+  return nullptr;
+}
+
+static std::string GetModuleName(uintptr_t PC) {
+  char ModulePathRaw[4096] = "";  // What's PATH_MAX in portable C++?
+  void *OffsetRaw = nullptr;
+  if (!EF->__sanitizer_get_module_and_offset_for_pc(
+      reinterpret_cast<void *>(PC), ModulePathRaw,
+      sizeof(ModulePathRaw), &OffsetRaw))
+    return "";
+  return ModulePathRaw;
+}
+
+template<class CallBack>
+void TracePC::IterateCoveredFunctions(CallBack CB) {
+  for (size_t i = 0; i < NumPCTables; i++) {
+    auto &M = ModulePCTable[i];
+    assert(M.Start < M.Stop);
+    auto ModuleName = GetModuleName(M.Start->PC);
+    for (auto NextFE = M.Start; NextFE < M.Stop; ) {
+      auto FE = NextFE;
+      assert(PcIsFuncEntry(FE) && "Not a function entry point");
+      do {
+        NextFE++;
+      } while (NextFE < M.Stop && !(PcIsFuncEntry(NextFE)));
+      CB(FE, NextFE, ObservedFuncs[FE->PC]);
+    }
+  }
+}
+
+int TracePC::SetFocusFunction(const std::string &FuncName) {
+  // This function should be called once.
+  assert(!FocusFunctionCounterPtr);
+  // "auto" is not a valid function name. If this function is called with "auto"
+  // that means the auto focus functionality failed.
+  if (FuncName.empty() || FuncName == "auto")
+    return 0;
+  for (size_t M = 0; M < NumModules; M++) {
+    auto &PCTE = ModulePCTable[M];
+    size_t N = PCTE.Stop - PCTE.Start;
+    for (size_t I = 0; I < N; I++) {
+      if (!(PcIsFuncEntry(&PCTE.Start[I]))) continue;  // not a function entry.
+      auto Name = DescribePC("%F", GetNextInstructionPc(PCTE.Start[I].PC));
+      if (Name[0] == 'i' && Name[1] == 'n' && Name[2] == ' ')
+        Name = Name.substr(3, std::string::npos);
+      if (FuncName != Name) continue;
+      Printf("INFO: Focus function is set to '%s'\n", Name.c_str());
+      FocusFunctionCounterPtr = Modules[M].Start() + I;
+      return 0;
+    }
+  }
+
+  Printf("ERROR: Failed to set focus function. Make sure the function name is "
+         "valid (%s) and symbolization is enabled.\n", FuncName.c_str());
+  return 1;
+}
+
+bool TracePC::ObservedFocusFunction() {
+  return FocusFunctionCounterPtr && *FocusFunctionCounterPtr;
+}
+
+void TracePC::PrintCoverage() {
+  if (!EF->__sanitizer_symbolize_pc ||
+      !EF->__sanitizer_get_module_and_offset_for_pc) {
+    Printf("INFO: __sanitizer_symbolize_pc or "
+           "__sanitizer_get_module_and_offset_for_pc is not available,"
+           " not printing coverage\n");
+    return;
+  }
+  Printf("COVERAGE:\n");
+  auto CoveredFunctionCallback = [&](const PCTableEntry *First,
+                                     const PCTableEntry *Last,
+                                     uintptr_t Counter) {
+    assert(First < Last);
+    auto VisualizePC = GetNextInstructionPc(First->PC);
+    std::string FileStr = DescribePC("%s", VisualizePC);
+    if (!IsInterestingCoverageFile(FileStr))
+      return;
+    std::string FunctionStr = DescribePC("%F", VisualizePC);
+    if (FunctionStr.find("in ") == 0)
+      FunctionStr = FunctionStr.substr(3);
+    std::string LineStr = DescribePC("%l", VisualizePC);
+    size_t NumEdges = Last - First;
+    Vector<uintptr_t> UncoveredPCs;
+    for (auto TE = First; TE < Last; TE++)
+      if (!ObservedPCs.count(TE))
+        UncoveredPCs.push_back(TE->PC);
+    Printf("%sCOVERED_FUNC: hits: %zd", Counter ? "" : "UN", Counter);
+    Printf(" edges: %zd/%zd", NumEdges - UncoveredPCs.size(), NumEdges);
+    Printf(" %s %s:%s\n", FunctionStr.c_str(), FileStr.c_str(),
+           LineStr.c_str());
+    if (Counter)
+      for (auto PC : UncoveredPCs)
+        Printf("  UNCOVERED_PC: %s\n",
+               DescribePC("%s:%l", GetNextInstructionPc(PC)).c_str());
+  };
+
+  IterateCoveredFunctions(CoveredFunctionCallback);
+}
+
+// Value profile.
+// We keep track of various values that affect control flow.
+// These values are inserted into a bit-set-based hash map.
+// Every new bit in the map is treated as a new coverage.
+//
+// For memcmp/strcmp/etc the interesting value is the length of the common
+// prefix of the parameters.
+// For cmp instructions the interesting value is a XOR of the parameters.
+// The interesting value is mixed up with the PC and is then added to the map.
+
+ATTRIBUTE_NO_SANITIZE_ALL
+void TracePC::AddValueForMemcmp(void *caller_pc, const void *s1, const void *s2,
+                                size_t n, bool StopAtZero) {
+  if (!n) return;
+  size_t Len = std::min(n, Word::GetMaxSize());
+  const uint8_t *A1 = reinterpret_cast<const uint8_t *>(s1);
+  const uint8_t *A2 = reinterpret_cast<const uint8_t *>(s2);
+  uint8_t B1[Word::kMaxSize];
+  uint8_t B2[Word::kMaxSize];
+  // Copy the data into locals in this non-msan-instrumented function
+  // to avoid msan complaining further.
+  size_t Hash = 0;  // Compute some simple hash of both strings.
+  for (size_t i = 0; i < Len; i++) {
+    B1[i] = A1[i];
+    B2[i] = A2[i];
+    size_t T = B1[i];
+    Hash ^= (T << 8) | B2[i];
+  }
+  size_t I = 0;
+  uint8_t HammingDistance = 0;
+  for (; I < Len; I++) {
+    if (B1[I] != B2[I] || (StopAtZero && B1[I] == 0)) {
+      HammingDistance = Popcountll(B1[I] ^ B2[I]);
+      break;
+    }
+  }
+  size_t PC = reinterpret_cast<size_t>(caller_pc);
+  size_t Idx = (PC & 4095) | (I << 12);
+  Idx += HammingDistance;
+  ValueProfileMap.AddValue(Idx);
+  TORCW.Insert(Idx ^ Hash, Word(B1, Len), Word(B2, Len));
+}
+
+template <class T>
+ATTRIBUTE_TARGET_POPCNT ALWAYS_INLINE
+ATTRIBUTE_NO_SANITIZE_ALL
+void TracePC::HandleCmp(uintptr_t PC, T Arg1, T Arg2) {
+  uint64_t ArgXor = Arg1 ^ Arg2;
+  if (sizeof(T) == 4)
+      TORC4.Insert(ArgXor, Arg1, Arg2);
+  else if (sizeof(T) == 8)
+      TORC8.Insert(ArgXor, Arg1, Arg2);
+  uint64_t HammingDistance = Popcountll(ArgXor);  // [0,64]
+  uint64_t AbsoluteDistance = (Arg1 == Arg2 ? 0 : Clzll(Arg1 - Arg2) + 1);
+  ValueProfileMap.AddValue(PC * 128 + HammingDistance);
+  ValueProfileMap.AddValue(PC * 128 + 64 + AbsoluteDistance);
+}
+
+static size_t InternalStrnlen(const char *S, size_t MaxLen) {
+  size_t Len = 0;
+  for (; Len < MaxLen && S[Len]; Len++) {}
+  return Len;
+}
+
+// Finds min of (strlen(S1), strlen(S2)).
+// Needed bacause one of these strings may actually be non-zero terminated.
+static size_t InternalStrnlen2(const char *S1, const char *S2) {
+  size_t Len = 0;
+  for (; S1[Len] && S2[Len]; Len++)  {}
+  return Len;
+}
+
+void TracePC::ClearInlineCounters() {
+  IterateCounterRegions([](const Module::Region &R){
+    if (R.Enabled)
+      memset(R.Start, 0, R.Stop - R.Start);
+  });
+}
+
+ATTRIBUTE_NO_SANITIZE_ALL
+void TracePC::RecordInitialStack() {
+  int stack;
+  __sancov_lowest_stack = InitialStack = reinterpret_cast<uintptr_t>(&stack);
+}
+
+uintptr_t TracePC::GetMaxStackOffset() const {
+  return InitialStack - __sancov_lowest_stack;  // Stack grows down
+}
+
+void WarnAboutDeprecatedInstrumentation(const char *flag) {
+  // Use RawPrint because Printf cannot be used on Windows before OutputFile is
+  // initialized.
+  RawPrint(flag);
+  RawPrint(
+      " is no longer supported by libFuzzer.\n"
+      "Please either migrate to a compiler that supports -fsanitize=fuzzer\n"
+      "or use an older version of libFuzzer\n");
+  exit(1);
+}
+
+} // namespace fuzzer
+
+extern "C" {
+ATTRIBUTE_INTERFACE
+ATTRIBUTE_NO_SANITIZE_ALL
+void __sanitizer_cov_trace_pc_guard(uint32_t *Guard) {
+  fuzzer::WarnAboutDeprecatedInstrumentation(
+      "-fsanitize-coverage=trace-pc-guard");
+}
+
+// Best-effort support for -fsanitize-coverage=trace-pc, which is available
+// in both Clang and GCC.
+ATTRIBUTE_INTERFACE
+ATTRIBUTE_NO_SANITIZE_ALL
+void __sanitizer_cov_trace_pc() {
+  fuzzer::WarnAboutDeprecatedInstrumentation("-fsanitize-coverage=trace-pc");
+}
+
+ATTRIBUTE_INTERFACE
+void __sanitizer_cov_trace_pc_guard_init(uint32_t *Start, uint32_t *Stop) {
+  fuzzer::WarnAboutDeprecatedInstrumentation(
+      "-fsanitize-coverage=trace-pc-guard");
+}
+
+ATTRIBUTE_INTERFACE
+void __sanitizer_cov_8bit_counters_init(uint8_t *Start, uint8_t *Stop) {
+  fuzzer::TPC.HandleInline8bitCountersInit(Start, Stop);
+}
+
+ATTRIBUTE_INTERFACE
+void __sanitizer_cov_pcs_init(const uintptr_t *pcs_beg,
+                              const uintptr_t *pcs_end) {
+  fuzzer::TPC.HandlePCsInit(pcs_beg, pcs_end);
+}
+
+ATTRIBUTE_INTERFACE
+ATTRIBUTE_NO_SANITIZE_ALL
+void __sanitizer_cov_trace_pc_indir(uintptr_t Callee) {
+  uintptr_t PC = reinterpret_cast<uintptr_t>(GET_CALLER_PC());
+  fuzzer::TPC.HandleCallerCallee(PC, Callee);
+}
+
+ATTRIBUTE_INTERFACE
+ATTRIBUTE_NO_SANITIZE_ALL
+ATTRIBUTE_TARGET_POPCNT
+void __sanitizer_cov_trace_cmp8(uint64_t Arg1, uint64_t Arg2) {
+  uintptr_t PC = reinterpret_cast<uintptr_t>(GET_CALLER_PC());
+  fuzzer::TPC.HandleCmp(PC, Arg1, Arg2);
+}
+
+ATTRIBUTE_INTERFACE
+ATTRIBUTE_NO_SANITIZE_ALL
+ATTRIBUTE_TARGET_POPCNT
+// Now the __sanitizer_cov_trace_const_cmp[1248] callbacks just mimic
+// the behaviour of __sanitizer_cov_trace_cmp[1248] ones. This, however,
+// should be changed later to make full use of instrumentation.
+void __sanitizer_cov_trace_const_cmp8(uint64_t Arg1, uint64_t Arg2) {
+  uintptr_t PC = reinterpret_cast<uintptr_t>(GET_CALLER_PC());
+  fuzzer::TPC.HandleCmp(PC, Arg1, Arg2);
+}
+
+ATTRIBUTE_INTERFACE
+ATTRIBUTE_NO_SANITIZE_ALL
+ATTRIBUTE_TARGET_POPCNT
+void __sanitizer_cov_trace_cmp4(uint32_t Arg1, uint32_t Arg2) {
+  uintptr_t PC = reinterpret_cast<uintptr_t>(GET_CALLER_PC());
+  fuzzer::TPC.HandleCmp(PC, Arg1, Arg2);
+}
+
+ATTRIBUTE_INTERFACE
+ATTRIBUTE_NO_SANITIZE_ALL
+ATTRIBUTE_TARGET_POPCNT
+void __sanitizer_cov_trace_const_cmp4(uint32_t Arg1, uint32_t Arg2) {
+  uintptr_t PC = reinterpret_cast<uintptr_t>(GET_CALLER_PC());
+  fuzzer::TPC.HandleCmp(PC, Arg1, Arg2);
+}
+
+ATTRIBUTE_INTERFACE
+ATTRIBUTE_NO_SANITIZE_ALL
+ATTRIBUTE_TARGET_POPCNT
+void __sanitizer_cov_trace_cmp2(uint16_t Arg1, uint16_t Arg2) {
+  uintptr_t PC = reinterpret_cast<uintptr_t>(GET_CALLER_PC());
+  fuzzer::TPC.HandleCmp(PC, Arg1, Arg2);
+}
+
+ATTRIBUTE_INTERFACE
+ATTRIBUTE_NO_SANITIZE_ALL
+ATTRIBUTE_TARGET_POPCNT
+void __sanitizer_cov_trace_const_cmp2(uint16_t Arg1, uint16_t Arg2) {
+  uintptr_t PC = reinterpret_cast<uintptr_t>(GET_CALLER_PC());
+  fuzzer::TPC.HandleCmp(PC, Arg1, Arg2);
+}
+
+ATTRIBUTE_INTERFACE
+ATTRIBUTE_NO_SANITIZE_ALL
+ATTRIBUTE_TARGET_POPCNT
+void __sanitizer_cov_trace_cmp1(uint8_t Arg1, uint8_t Arg2) {
+  uintptr_t PC = reinterpret_cast<uintptr_t>(GET_CALLER_PC());
+  fuzzer::TPC.HandleCmp(PC, Arg1, Arg2);
+}
+
+ATTRIBUTE_INTERFACE
+ATTRIBUTE_NO_SANITIZE_ALL
+ATTRIBUTE_TARGET_POPCNT
+void __sanitizer_cov_trace_const_cmp1(uint8_t Arg1, uint8_t Arg2) {
+  uintptr_t PC = reinterpret_cast<uintptr_t>(GET_CALLER_PC());
+  fuzzer::TPC.HandleCmp(PC, Arg1, Arg2);
+}
+
+ATTRIBUTE_INTERFACE
+ATTRIBUTE_NO_SANITIZE_ALL
+ATTRIBUTE_TARGET_POPCNT
+void __sanitizer_cov_trace_switch(uint64_t Val, uint64_t *Cases) {
+  uint64_t N = Cases[0];
+  uint64_t ValSizeInBits = Cases[1];
+  uint64_t *Vals = Cases + 2;
+  // Skip the most common and the most boring case: all switch values are small.
+  // We may want to skip this at compile-time, but it will make the
+  // instrumentation less general.
+  if (Vals[N - 1]  < 256)
+    return;
+  // Also skip small inputs values, they won't give good signal.
+  if (Val < 256)
+    return;
+  uintptr_t PC = reinterpret_cast<uintptr_t>(GET_CALLER_PC());
+  size_t i;
+  uint64_t Smaller = 0;
+  uint64_t Larger = ~(uint64_t)0;
+  // Find two switch values such that Smaller < Val < Larger.
+  // Use 0 and 0xfff..f as the defaults.
+  for (i = 0; i < N; i++) {
+    if (Val < Vals[i]) {
+      Larger = Vals[i];
+      break;
+    }
+    if (Val > Vals[i]) Smaller = Vals[i];
+  }
+
+  // Apply HandleCmp to {Val,Smaller} and {Val, Larger},
+  // use i as the PC modifier for HandleCmp.
+  if (ValSizeInBits == 16) {
+    fuzzer::TPC.HandleCmp(PC + 2 * i, static_cast<uint16_t>(Val),
+                          (uint16_t)(Smaller));
+    fuzzer::TPC.HandleCmp(PC + 2 * i + 1, static_cast<uint16_t>(Val),
+                          (uint16_t)(Larger));
+  } else if (ValSizeInBits == 32) {
+    fuzzer::TPC.HandleCmp(PC + 2 * i, static_cast<uint32_t>(Val),
+                          (uint32_t)(Smaller));
+    fuzzer::TPC.HandleCmp(PC + 2 * i + 1, static_cast<uint32_t>(Val),
+                          (uint32_t)(Larger));
+  } else {
+    fuzzer::TPC.HandleCmp(PC + 2*i, Val, Smaller);
+    fuzzer::TPC.HandleCmp(PC + 2*i + 1, Val, Larger);
+  }
+}
+
+ATTRIBUTE_INTERFACE
+ATTRIBUTE_NO_SANITIZE_ALL
+ATTRIBUTE_TARGET_POPCNT
+void __sanitizer_cov_trace_div4(uint32_t Val) {
+  uintptr_t PC = reinterpret_cast<uintptr_t>(GET_CALLER_PC());
+  fuzzer::TPC.HandleCmp(PC, Val, (uint32_t)0);
+}
+
+ATTRIBUTE_INTERFACE
+ATTRIBUTE_NO_SANITIZE_ALL
+ATTRIBUTE_TARGET_POPCNT
+void __sanitizer_cov_trace_div8(uint64_t Val) {
+  uintptr_t PC = reinterpret_cast<uintptr_t>(GET_CALLER_PC());
+  fuzzer::TPC.HandleCmp(PC, Val, (uint64_t)0);
+}
+
+ATTRIBUTE_INTERFACE
+ATTRIBUTE_NO_SANITIZE_ALL
+ATTRIBUTE_TARGET_POPCNT
+void __sanitizer_cov_trace_gep(uintptr_t Idx) {
+  uintptr_t PC = reinterpret_cast<uintptr_t>(GET_CALLER_PC());
+  fuzzer::TPC.HandleCmp(PC, Idx, (uintptr_t)0);
+}
+
+ATTRIBUTE_INTERFACE ATTRIBUTE_NO_SANITIZE_MEMORY
+void __sanitizer_weak_hook_memcmp(void *caller_pc, const void *s1,
+                                  const void *s2, size_t n, int result) {
+  if (!fuzzer::RunningUserCallback) return;
+  if (result == 0) return;  // No reason to mutate.
+  if (n <= 1) return;  // Not interesting.
+  fuzzer::TPC.AddValueForMemcmp(caller_pc, s1, s2, n, /*StopAtZero*/false);
+}
+
+ATTRIBUTE_INTERFACE ATTRIBUTE_NO_SANITIZE_MEMORY
+void __sanitizer_weak_hook_strncmp(void *caller_pc, const char *s1,
+                                   const char *s2, size_t n, int result) {
+  if (!fuzzer::RunningUserCallback) return;
+  if (result == 0) return;  // No reason to mutate.
+  size_t Len1 = fuzzer::InternalStrnlen(s1, n);
+  size_t Len2 = fuzzer::InternalStrnlen(s2, n);
+  n = std::min(n, Len1);
+  n = std::min(n, Len2);
+  if (n <= 1) return;  // Not interesting.
+  fuzzer::TPC.AddValueForMemcmp(caller_pc, s1, s2, n, /*StopAtZero*/true);
+}
+
+ATTRIBUTE_INTERFACE ATTRIBUTE_NO_SANITIZE_MEMORY
+void __sanitizer_weak_hook_strcmp(void *caller_pc, const char *s1,
+                                   const char *s2, int result) {
+  if (!fuzzer::RunningUserCallback) return;
+  if (result == 0) return;  // No reason to mutate.
+  size_t N = fuzzer::InternalStrnlen2(s1, s2);
+  if (N <= 1) return;  // Not interesting.
+  fuzzer::TPC.AddValueForMemcmp(caller_pc, s1, s2, N, /*StopAtZero*/true);
+}
+
+ATTRIBUTE_INTERFACE ATTRIBUTE_NO_SANITIZE_MEMORY
+void __sanitizer_weak_hook_strncasecmp(void *called_pc, const char *s1,
+                                       const char *s2, size_t n, int result) {
+  if (!fuzzer::RunningUserCallback) return;
+  return __sanitizer_weak_hook_strncmp(called_pc, s1, s2, n, result);
+}
+
+ATTRIBUTE_INTERFACE ATTRIBUTE_NO_SANITIZE_MEMORY
+void __sanitizer_weak_hook_strcasecmp(void *called_pc, const char *s1,
+                                      const char *s2, int result) {
+  if (!fuzzer::RunningUserCallback) return;
+  return __sanitizer_weak_hook_strcmp(called_pc, s1, s2, result);
+}
+
+ATTRIBUTE_INTERFACE ATTRIBUTE_NO_SANITIZE_MEMORY
+void __sanitizer_weak_hook_strstr(void *called_pc, const char *s1,
+                                  const char *s2, char *result) {
+  if (!fuzzer::RunningUserCallback) return;
+  fuzzer::TPC.MMT.Add(reinterpret_cast<const uint8_t *>(s2), strlen(s2));
+}
+
+ATTRIBUTE_INTERFACE ATTRIBUTE_NO_SANITIZE_MEMORY
+void __sanitizer_weak_hook_strcasestr(void *called_pc, const char *s1,
+                                      const char *s2, char *result) {
+  if (!fuzzer::RunningUserCallback) return;
+  fuzzer::TPC.MMT.Add(reinterpret_cast<const uint8_t *>(s2), strlen(s2));
+}
+
+ATTRIBUTE_INTERFACE ATTRIBUTE_NO_SANITIZE_MEMORY
+void __sanitizer_weak_hook_memmem(void *called_pc, const void *s1, size_t len1,
+                                  const void *s2, size_t len2, void *result) {
+  if (!fuzzer::RunningUserCallback) return;
+  fuzzer::TPC.MMT.Add(reinterpret_cast<const uint8_t *>(s2), len2);
+}
+}  // extern "C"