Home | History | Annotate | Download | only in sanitizer_common
      1 //===-- sanitizer_common.h --------------------------------------*- C++ -*-===//
      2 //
      3 //                     The LLVM Compiler Infrastructure
      4 //
      5 // This file is distributed under the University of Illinois Open Source
      6 // License. See LICENSE.TXT for details.
      7 //
      8 //===----------------------------------------------------------------------===//
      9 //
     10 // This file is shared between run-time libraries of sanitizers.
     11 //
     12 // It declares common functions and classes that are used in both runtimes.
     13 // Implementation of some functions are provided in sanitizer_common, while
     14 // others must be defined by run-time library itself.
     15 //===----------------------------------------------------------------------===//
     16 #ifndef SANITIZER_COMMON_H
     17 #define SANITIZER_COMMON_H
     18 
     19 #include "sanitizer_flags.h"
     20 #include "sanitizer_interface_internal.h"
     21 #include "sanitizer_internal_defs.h"
     22 #include "sanitizer_libc.h"
     23 #include "sanitizer_list.h"
     24 #include "sanitizer_mutex.h"
     25 
     26 #ifdef _MSC_VER
     27 extern "C" void _ReadWriteBarrier();
     28 #pragma intrinsic(_ReadWriteBarrier)
     29 #endif
     30 
     31 namespace __sanitizer {
     32 struct StackTrace;
     33 struct AddressInfo;
     34 
     35 // Constants.
     36 const uptr kWordSize = SANITIZER_WORDSIZE / 8;
     37 const uptr kWordSizeInBits = 8 * kWordSize;
     38 
     39 #if defined(__powerpc__) || defined(__powerpc64__)
     40   const uptr kCacheLineSize = 128;
     41 #else
     42   const uptr kCacheLineSize = 64;
     43 #endif
     44 
     45 const uptr kMaxPathLength = 4096;
     46 
     47 // 16K loaded modules should be enough for everyone.
     48 static const uptr kMaxNumberOfModules = 1 << 14;
     49 
     50 const uptr kMaxThreadStackSize = 1 << 30;  // 1Gb
     51 
     52 static const uptr kErrorMessageBufferSize = 1 << 16;
     53 
     54 // Denotes fake PC values that come from JIT/JAVA/etc.
     55 // For such PC values __tsan_symbolize_external() will be called.
     56 const u64 kExternalPCBit = 1ULL << 60;
     57 
     58 extern const char *SanitizerToolName;  // Can be changed by the tool.
     59 
     60 extern atomic_uint32_t current_verbosity;
     61 INLINE void SetVerbosity(int verbosity) {
     62   atomic_store(&current_verbosity, verbosity, memory_order_relaxed);
     63 }
     64 INLINE int Verbosity() {
     65   return atomic_load(&current_verbosity, memory_order_relaxed);
     66 }
     67 
     68 uptr GetPageSize();
     69 uptr GetPageSizeCached();
     70 uptr GetMmapGranularity();
     71 uptr GetMaxVirtualAddress();
     72 // Threads
     73 uptr GetTid();
     74 uptr GetThreadSelf();
     75 void GetThreadStackTopAndBottom(bool at_initialization, uptr *stack_top,
     76                                 uptr *stack_bottom);
     77 void GetThreadStackAndTls(bool main, uptr *stk_addr, uptr *stk_size,
     78                           uptr *tls_addr, uptr *tls_size);
     79 
     80 // Memory management
     81 void *MmapOrDie(uptr size, const char *mem_type, bool raw_report = false);
     82 INLINE void *MmapOrDieQuietly(uptr size, const char *mem_type) {
     83   return MmapOrDie(size, mem_type, /*raw_report*/ true);
     84 }
     85 void UnmapOrDie(void *addr, uptr size);
     86 void *MmapFixedNoReserve(uptr fixed_addr, uptr size,
     87                          const char *name = nullptr);
     88 void *MmapNoReserveOrDie(uptr size, const char *mem_type);
     89 void *MmapFixedOrDie(uptr fixed_addr, uptr size);
     90 void *MmapNoAccess(uptr fixed_addr, uptr size, const char *name = nullptr);
     91 // Map aligned chunk of address space; size and alignment are powers of two.
     92 void *MmapAlignedOrDie(uptr size, uptr alignment, const char *mem_type);
     93 // Disallow access to a memory range.  Use MmapNoAccess to allocate an
     94 // unaccessible memory.
     95 bool MprotectNoAccess(uptr addr, uptr size);
     96 
     97 // Used to check if we can map shadow memory to a fixed location.
     98 bool MemoryRangeIsAvailable(uptr range_start, uptr range_end);
     99 void FlushUnneededShadowMemory(uptr addr, uptr size);
    100 void IncreaseTotalMmap(uptr size);
    101 void DecreaseTotalMmap(uptr size);
    102 uptr GetRSS();
    103 void NoHugePagesInRegion(uptr addr, uptr length);
    104 void DontDumpShadowMemory(uptr addr, uptr length);
    105 // Check if the built VMA size matches the runtime one.
    106 void CheckVMASize();
    107 
    108 // InternalScopedBuffer can be used instead of large stack arrays to
    109 // keep frame size low.
    110 // FIXME: use InternalAlloc instead of MmapOrDie once
    111 // InternalAlloc is made libc-free.
    112 template<typename T>
    113 class InternalScopedBuffer {
    114  public:
    115   explicit InternalScopedBuffer(uptr cnt) {
    116     cnt_ = cnt;
    117     ptr_ = (T*)MmapOrDie(cnt * sizeof(T), "InternalScopedBuffer");
    118   }
    119   ~InternalScopedBuffer() {
    120     UnmapOrDie(ptr_, cnt_ * sizeof(T));
    121   }
    122   T &operator[](uptr i) { return ptr_[i]; }
    123   T *data() { return ptr_; }
    124   uptr size() { return cnt_ * sizeof(T); }
    125 
    126  private:
    127   T *ptr_;
    128   uptr cnt_;
    129   // Disallow evil constructors.
    130   InternalScopedBuffer(const InternalScopedBuffer&);
    131   void operator=(const InternalScopedBuffer&);
    132 };
    133 
    134 class InternalScopedString : public InternalScopedBuffer<char> {
    135  public:
    136   explicit InternalScopedString(uptr max_length)
    137       : InternalScopedBuffer<char>(max_length), length_(0) {
    138     (*this)[0] = '\0';
    139   }
    140   uptr length() { return length_; }
    141   void clear() {
    142     (*this)[0] = '\0';
    143     length_ = 0;
    144   }
    145   void append(const char *format, ...);
    146 
    147  private:
    148   uptr length_;
    149 };
    150 
    151 // Simple low-level (mmap-based) allocator for internal use. Doesn't have
    152 // constructor, so all instances of LowLevelAllocator should be
    153 // linker initialized.
    154 class LowLevelAllocator {
    155  public:
    156   // Requires an external lock.
    157   void *Allocate(uptr size);
    158  private:
    159   char *allocated_end_;
    160   char *allocated_current_;
    161 };
    162 typedef void (*LowLevelAllocateCallback)(uptr ptr, uptr size);
    163 // Allows to register tool-specific callbacks for LowLevelAllocator.
    164 // Passing NULL removes the callback.
    165 void SetLowLevelAllocateCallback(LowLevelAllocateCallback callback);
    166 
    167 // IO
    168 void RawWrite(const char *buffer);
    169 bool ColorizeReports();
    170 void RemoveANSIEscapeSequencesFromString(char *buffer);
    171 void Printf(const char *format, ...);
    172 void Report(const char *format, ...);
    173 void SetPrintfAndReportCallback(void (*callback)(const char *));
    174 #define VReport(level, ...)                                              \
    175   do {                                                                   \
    176     if ((uptr)Verbosity() >= (level)) Report(__VA_ARGS__); \
    177   } while (0)
    178 #define VPrintf(level, ...)                                              \
    179   do {                                                                   \
    180     if ((uptr)Verbosity() >= (level)) Printf(__VA_ARGS__); \
    181   } while (0)
    182 
    183 // Can be used to prevent mixing error reports from different sanitizers.
    184 extern StaticSpinMutex CommonSanitizerReportMutex;
    185 
    186 struct ReportFile {
    187   void Write(const char *buffer, uptr length);
    188   bool SupportsColors();
    189   void SetReportPath(const char *path);
    190 
    191   // Don't use fields directly. They are only declared public to allow
    192   // aggregate initialization.
    193 
    194   // Protects fields below.
    195   StaticSpinMutex *mu;
    196   // Opened file descriptor. Defaults to stderr. It may be equal to
    197   // kInvalidFd, in which case new file will be opened when necessary.
    198   fd_t fd;
    199   // Path prefix of report file, set via __sanitizer_set_report_path.
    200   char path_prefix[kMaxPathLength];
    201   // Full path to report, obtained as <path_prefix>.PID
    202   char full_path[kMaxPathLength];
    203   // PID of the process that opened fd. If a fork() occurs,
    204   // the PID of child will be different from fd_pid.
    205   uptr fd_pid;
    206 
    207  private:
    208   void ReopenIfNecessary();
    209 };
    210 extern ReportFile report_file;
    211 
    212 extern uptr stoptheworld_tracer_pid;
    213 extern uptr stoptheworld_tracer_ppid;
    214 
    215 enum FileAccessMode {
    216   RdOnly,
    217   WrOnly,
    218   RdWr
    219 };
    220 
    221 // Returns kInvalidFd on error.
    222 fd_t OpenFile(const char *filename, FileAccessMode mode,
    223               error_t *errno_p = nullptr);
    224 void CloseFile(fd_t);
    225 
    226 // Return true on success, false on error.
    227 bool ReadFromFile(fd_t fd, void *buff, uptr buff_size,
    228                   uptr *bytes_read = nullptr, error_t *error_p = nullptr);
    229 bool WriteToFile(fd_t fd, const void *buff, uptr buff_size,
    230                  uptr *bytes_written = nullptr, error_t *error_p = nullptr);
    231 
    232 bool RenameFile(const char *oldpath, const char *newpath,
    233                 error_t *error_p = nullptr);
    234 
    235 // Scoped file handle closer.
    236 struct FileCloser {
    237   explicit FileCloser(fd_t fd) : fd(fd) {}
    238   ~FileCloser() { CloseFile(fd); }
    239   fd_t fd;
    240 };
    241 
    242 bool SupportsColoredOutput(fd_t fd);
    243 
    244 // Opens the file 'file_name" and reads up to 'max_len' bytes.
    245 // The resulting buffer is mmaped and stored in '*buff'.
    246 // The size of the mmaped region is stored in '*buff_size'.
    247 // The total number of read bytes is stored in '*read_len'.
    248 // Returns true if file was successfully opened and read.
    249 bool ReadFileToBuffer(const char *file_name, char **buff, uptr *buff_size,
    250                       uptr *read_len, uptr max_len = 1 << 26,
    251                       error_t *errno_p = nullptr);
    252 // Maps given file to virtual memory, and returns pointer to it
    253 // (or NULL if mapping fails). Stores the size of mmaped region
    254 // in '*buff_size'.
    255 void *MapFileToMemory(const char *file_name, uptr *buff_size);
    256 void *MapWritableFileToMemory(void *addr, uptr size, fd_t fd, OFF_T offset);
    257 
    258 bool IsAccessibleMemoryRange(uptr beg, uptr size);
    259 
    260 // Error report formatting.
    261 const char *StripPathPrefix(const char *filepath,
    262                             const char *strip_file_prefix);
    263 // Strip the directories from the module name.
    264 const char *StripModuleName(const char *module);
    265 
    266 // OS
    267 uptr ReadBinaryName(/*out*/char *buf, uptr buf_len);
    268 uptr ReadBinaryNameCached(/*out*/char *buf, uptr buf_len);
    269 uptr ReadLongProcessName(/*out*/ char *buf, uptr buf_len);
    270 const char *GetProcessName();
    271 void UpdateProcessName();
    272 void CacheBinaryName();
    273 void DisableCoreDumperIfNecessary();
    274 void DumpProcessMap();
    275 bool FileExists(const char *filename);
    276 const char *GetEnv(const char *name);
    277 bool SetEnv(const char *name, const char *value);
    278 const char *GetPwd();
    279 char *FindPathToBinary(const char *name);
    280 bool IsPathSeparator(const char c);
    281 bool IsAbsolutePath(const char *path);
    282 
    283 u32 GetUid();
    284 void ReExec();
    285 bool StackSizeIsUnlimited();
    286 void SetStackSizeLimitInBytes(uptr limit);
    287 bool AddressSpaceIsUnlimited();
    288 void SetAddressSpaceUnlimited();
    289 void AdjustStackSize(void *attr);
    290 void PrepareForSandboxing(__sanitizer_sandbox_arguments *args);
    291 void CovPrepareForSandboxing(__sanitizer_sandbox_arguments *args);
    292 void SetSandboxingCallback(void (*f)());
    293 
    294 void CoverageUpdateMapping();
    295 void CovBeforeFork();
    296 void CovAfterFork(int child_pid);
    297 
    298 void InitializeCoverage(bool enabled, const char *coverage_dir);
    299 void ReInitializeCoverage(bool enabled, const char *coverage_dir);
    300 
    301 void InitTlsSize();
    302 uptr GetTlsSize();
    303 
    304 // Other
    305 void SleepForSeconds(int seconds);
    306 void SleepForMillis(int millis);
    307 u64 NanoTime();
    308 int Atexit(void (*function)(void));
    309 void SortArray(uptr *array, uptr size);
    310 bool TemplateMatch(const char *templ, const char *str);
    311 
    312 // Exit
    313 void NORETURN Abort();
    314 void NORETURN Die();
    315 void NORETURN
    316 CheckFailed(const char *file, int line, const char *cond, u64 v1, u64 v2);
    317 void NORETURN ReportMmapFailureAndDie(uptr size, const char *mem_type,
    318                                       const char *mmap_type, error_t err,
    319                                       bool raw_report = false);
    320 
    321 // Set the name of the current thread to 'name', return true on succees.
    322 // The name may be truncated to a system-dependent limit.
    323 bool SanitizerSetThreadName(const char *name);
    324 // Get the name of the current thread (no more than max_len bytes),
    325 // return true on succees. name should have space for at least max_len+1 bytes.
    326 bool SanitizerGetThreadName(char *name, int max_len);
    327 
    328 // Specific tools may override behavior of "Die" and "CheckFailed" functions
    329 // to do tool-specific job.
    330 typedef void (*DieCallbackType)(void);
    331 
    332 // It's possible to add several callbacks that would be run when "Die" is
    333 // called. The callbacks will be run in the opposite order. The tools are
    334 // strongly recommended to setup all callbacks during initialization, when there
    335 // is only a single thread.
    336 bool AddDieCallback(DieCallbackType callback);
    337 bool RemoveDieCallback(DieCallbackType callback);
    338 
    339 void SetUserDieCallback(DieCallbackType callback);
    340 
    341 typedef void (*CheckFailedCallbackType)(const char *, int, const char *,
    342                                        u64, u64);
    343 void SetCheckFailedCallback(CheckFailedCallbackType callback);
    344 
    345 // Callback will be called if soft_rss_limit_mb is given and the limit is
    346 // exceeded (exceeded==true) or if rss went down below the limit
    347 // (exceeded==false).
    348 // The callback should be registered once at the tool init time.
    349 void SetSoftRssLimitExceededCallback(void (*Callback)(bool exceeded));
    350 
    351 // Functions related to signal handling.
    352 typedef void (*SignalHandlerType)(int, void *, void *);
    353 bool IsDeadlySignal(int signum);
    354 void InstallDeadlySignalHandlers(SignalHandlerType handler);
    355 // Alternative signal stack (POSIX-only).
    356 void SetAlternateSignalStack();
    357 void UnsetAlternateSignalStack();
    358 
    359 // We don't want a summary too long.
    360 const int kMaxSummaryLength = 1024;
    361 // Construct a one-line string:
    362 //   SUMMARY: SanitizerToolName: error_message
    363 // and pass it to __sanitizer_report_error_summary.
    364 void ReportErrorSummary(const char *error_message);
    365 // Same as above, but construct error_message as:
    366 //   error_type file:line[:column][ function]
    367 void ReportErrorSummary(const char *error_type, const AddressInfo &info);
    368 // Same as above, but obtains AddressInfo by symbolizing top stack trace frame.
    369 void ReportErrorSummary(const char *error_type, StackTrace *trace);
    370 
    371 // Math
    372 #if SANITIZER_WINDOWS && !defined(__clang__) && !defined(__GNUC__)
    373 extern "C" {
    374 unsigned char _BitScanForward(unsigned long *index, unsigned long mask);  // NOLINT
    375 unsigned char _BitScanReverse(unsigned long *index, unsigned long mask);  // NOLINT
    376 #if defined(_WIN64)
    377 unsigned char _BitScanForward64(unsigned long *index, unsigned __int64 mask);  // NOLINT
    378 unsigned char _BitScanReverse64(unsigned long *index, unsigned __int64 mask);  // NOLINT
    379 #endif
    380 }
    381 #endif
    382 
    383 INLINE uptr MostSignificantSetBitIndex(uptr x) {
    384   CHECK_NE(x, 0U);
    385   unsigned long up;  // NOLINT
    386 #if !SANITIZER_WINDOWS || defined(__clang__) || defined(__GNUC__)
    387 # ifdef _WIN64
    388   up = SANITIZER_WORDSIZE - 1 - __builtin_clzll(x);
    389 # else
    390   up = SANITIZER_WORDSIZE - 1 - __builtin_clzl(x);
    391 # endif
    392 #elif defined(_WIN64)
    393   _BitScanReverse64(&up, x);
    394 #else
    395   _BitScanReverse(&up, x);
    396 #endif
    397   return up;
    398 }
    399 
    400 INLINE uptr LeastSignificantSetBitIndex(uptr x) {
    401   CHECK_NE(x, 0U);
    402   unsigned long up;  // NOLINT
    403 #if !SANITIZER_WINDOWS || defined(__clang__) || defined(__GNUC__)
    404 # ifdef _WIN64
    405   up = __builtin_ctzll(x);
    406 # else
    407   up = __builtin_ctzl(x);
    408 # endif
    409 #elif defined(_WIN64)
    410   _BitScanForward64(&up, x);
    411 #else
    412   _BitScanForward(&up, x);
    413 #endif
    414   return up;
    415 }
    416 
    417 INLINE bool IsPowerOfTwo(uptr x) {
    418   return (x & (x - 1)) == 0;
    419 }
    420 
    421 INLINE uptr RoundUpToPowerOfTwo(uptr size) {
    422   CHECK(size);
    423   if (IsPowerOfTwo(size)) return size;
    424 
    425   uptr up = MostSignificantSetBitIndex(size);
    426   CHECK(size < (1ULL << (up + 1)));
    427   CHECK(size > (1ULL << up));
    428   return 1ULL << (up + 1);
    429 }
    430 
    431 INLINE uptr RoundUpTo(uptr size, uptr boundary) {
    432   RAW_CHECK(IsPowerOfTwo(boundary));
    433   return (size + boundary - 1) & ~(boundary - 1);
    434 }
    435 
    436 INLINE uptr RoundDownTo(uptr x, uptr boundary) {
    437   return x & ~(boundary - 1);
    438 }
    439 
    440 INLINE bool IsAligned(uptr a, uptr alignment) {
    441   return (a & (alignment - 1)) == 0;
    442 }
    443 
    444 INLINE uptr Log2(uptr x) {
    445   CHECK(IsPowerOfTwo(x));
    446   return LeastSignificantSetBitIndex(x);
    447 }
    448 
    449 // Don't use std::min, std::max or std::swap, to minimize dependency
    450 // on libstdc++.
    451 template<class T> T Min(T a, T b) { return a < b ? a : b; }
    452 template<class T> T Max(T a, T b) { return a > b ? a : b; }
    453 template<class T> void Swap(T& a, T& b) {
    454   T tmp = a;
    455   a = b;
    456   b = tmp;
    457 }
    458 
    459 // Char handling
    460 INLINE bool IsSpace(int c) {
    461   return (c == ' ') || (c == '\n') || (c == '\t') ||
    462          (c == '\f') || (c == '\r') || (c == '\v');
    463 }
    464 INLINE bool IsDigit(int c) {
    465   return (c >= '0') && (c <= '9');
    466 }
    467 INLINE int ToLower(int c) {
    468   return (c >= 'A' && c <= 'Z') ? (c + 'a' - 'A') : c;
    469 }
    470 
    471 // A low-level vector based on mmap. May incur a significant memory overhead for
    472 // small vectors.
    473 // WARNING: The current implementation supports only POD types.
    474 template<typename T>
    475 class InternalMmapVectorNoCtor {
    476  public:
    477   void Initialize(uptr initial_capacity) {
    478     capacity_ = Max(initial_capacity, (uptr)1);
    479     size_ = 0;
    480     data_ = (T *)MmapOrDie(capacity_ * sizeof(T), "InternalMmapVectorNoCtor");
    481   }
    482   void Destroy() {
    483     UnmapOrDie(data_, capacity_ * sizeof(T));
    484   }
    485   T &operator[](uptr i) {
    486     CHECK_LT(i, size_);
    487     return data_[i];
    488   }
    489   const T &operator[](uptr i) const {
    490     CHECK_LT(i, size_);
    491     return data_[i];
    492   }
    493   void push_back(const T &element) {
    494     CHECK_LE(size_, capacity_);
    495     if (size_ == capacity_) {
    496       uptr new_capacity = RoundUpToPowerOfTwo(size_ + 1);
    497       Resize(new_capacity);
    498     }
    499     data_[size_++] = element;
    500   }
    501   T &back() {
    502     CHECK_GT(size_, 0);
    503     return data_[size_ - 1];
    504   }
    505   void pop_back() {
    506     CHECK_GT(size_, 0);
    507     size_--;
    508   }
    509   uptr size() const {
    510     return size_;
    511   }
    512   const T *data() const {
    513     return data_;
    514   }
    515   T *data() {
    516     return data_;
    517   }
    518   uptr capacity() const {
    519     return capacity_;
    520   }
    521 
    522   void clear() { size_ = 0; }
    523   bool empty() const { return size() == 0; }
    524 
    525  private:
    526   void Resize(uptr new_capacity) {
    527     CHECK_GT(new_capacity, 0);
    528     CHECK_LE(size_, new_capacity);
    529     T *new_data = (T *)MmapOrDie(new_capacity * sizeof(T),
    530                                  "InternalMmapVector");
    531     internal_memcpy(new_data, data_, size_ * sizeof(T));
    532     T *old_data = data_;
    533     data_ = new_data;
    534     UnmapOrDie(old_data, capacity_ * sizeof(T));
    535     capacity_ = new_capacity;
    536   }
    537 
    538   T *data_;
    539   uptr capacity_;
    540   uptr size_;
    541 };
    542 
    543 template<typename T>
    544 class InternalMmapVector : public InternalMmapVectorNoCtor<T> {
    545  public:
    546   explicit InternalMmapVector(uptr initial_capacity) {
    547     InternalMmapVectorNoCtor<T>::Initialize(initial_capacity);
    548   }
    549   ~InternalMmapVector() { InternalMmapVectorNoCtor<T>::Destroy(); }
    550   // Disallow evil constructors.
    551   InternalMmapVector(const InternalMmapVector&);
    552   void operator=(const InternalMmapVector&);
    553 };
    554 
    555 // HeapSort for arrays and InternalMmapVector.
    556 template<class Container, class Compare>
    557 void InternalSort(Container *v, uptr size, Compare comp) {
    558   if (size < 2)
    559     return;
    560   // Stage 1: insert elements to the heap.
    561   for (uptr i = 1; i < size; i++) {
    562     uptr j, p;
    563     for (j = i; j > 0; j = p) {
    564       p = (j - 1) / 2;
    565       if (comp((*v)[p], (*v)[j]))
    566         Swap((*v)[j], (*v)[p]);
    567       else
    568         break;
    569     }
    570   }
    571   // Stage 2: swap largest element with the last one,
    572   // and sink the new top.
    573   for (uptr i = size - 1; i > 0; i--) {
    574     Swap((*v)[0], (*v)[i]);
    575     uptr j, max_ind;
    576     for (j = 0; j < i; j = max_ind) {
    577       uptr left = 2 * j + 1;
    578       uptr right = 2 * j + 2;
    579       max_ind = j;
    580       if (left < i && comp((*v)[max_ind], (*v)[left]))
    581         max_ind = left;
    582       if (right < i && comp((*v)[max_ind], (*v)[right]))
    583         max_ind = right;
    584       if (max_ind != j)
    585         Swap((*v)[j], (*v)[max_ind]);
    586       else
    587         break;
    588     }
    589   }
    590 }
    591 
    592 template<class Container, class Value, class Compare>
    593 uptr InternalBinarySearch(const Container &v, uptr first, uptr last,
    594                           const Value &val, Compare comp) {
    595   uptr not_found = last + 1;
    596   while (last >= first) {
    597     uptr mid = (first + last) / 2;
    598     if (comp(v[mid], val))
    599       first = mid + 1;
    600     else if (comp(val, v[mid]))
    601       last = mid - 1;
    602     else
    603       return mid;
    604   }
    605   return not_found;
    606 }
    607 
    608 // Represents a binary loaded into virtual memory (e.g. this can be an
    609 // executable or a shared object).
    610 class LoadedModule {
    611  public:
    612   LoadedModule() : full_name_(nullptr), base_address_(0) { ranges_.clear(); }
    613   void set(const char *module_name, uptr base_address);
    614   void clear();
    615   void addAddressRange(uptr beg, uptr end, bool executable);
    616   bool containsAddress(uptr address) const;
    617 
    618   const char *full_name() const { return full_name_; }
    619   uptr base_address() const { return base_address_; }
    620 
    621   struct AddressRange {
    622     AddressRange *next;
    623     uptr beg;
    624     uptr end;
    625     bool executable;
    626 
    627     AddressRange(uptr beg, uptr end, bool executable)
    628         : next(nullptr), beg(beg), end(end), executable(executable) {}
    629   };
    630 
    631   typedef IntrusiveList<AddressRange>::ConstIterator Iterator;
    632   Iterator ranges() const { return Iterator(&ranges_); }
    633 
    634  private:
    635   char *full_name_;  // Owned.
    636   uptr base_address_;
    637   IntrusiveList<AddressRange> ranges_;
    638 };
    639 
    640 // OS-dependent function that fills array with descriptions of at most
    641 // "max_modules" currently loaded modules. Returns the number of
    642 // initialized modules. If filter is nonzero, ignores modules for which
    643 // filter(full_name) is false.
    644 typedef bool (*string_predicate_t)(const char *);
    645 uptr GetListOfModules(LoadedModule *modules, uptr max_modules,
    646                       string_predicate_t filter);
    647 
    648 // Callback type for iterating over a set of memory ranges.
    649 typedef void (*RangeIteratorCallback)(uptr begin, uptr end, void *arg);
    650 
    651 enum AndroidApiLevel {
    652   ANDROID_NOT_ANDROID = 0,
    653   ANDROID_KITKAT = 19,
    654   ANDROID_LOLLIPOP_MR1 = 22,
    655   ANDROID_POST_LOLLIPOP = 23
    656 };
    657 
    658 void WriteToSyslog(const char *buffer);
    659 
    660 #if SANITIZER_MAC
    661 void LogFullErrorReport(const char *buffer);
    662 #else
    663 INLINE void LogFullErrorReport(const char *buffer) {}
    664 #endif
    665 
    666 #if SANITIZER_LINUX || SANITIZER_MAC
    667 void WriteOneLineToSyslog(const char *s);
    668 #else
    669 INLINE void WriteOneLineToSyslog(const char *s) {}
    670 #endif
    671 
    672 #if SANITIZER_LINUX
    673 // Initialize Android logging. Any writes before this are silently lost.
    674 void AndroidLogInit();
    675 bool ShouldLogAfterPrintf();
    676 #else
    677 INLINE void AndroidLogInit() {}
    678 INLINE bool ShouldLogAfterPrintf() { return false; }
    679 #endif
    680 
    681 #if SANITIZER_ANDROID
    682 void SanitizerInitializeUnwinder();
    683 AndroidApiLevel AndroidGetApiLevel();
    684 #else
    685 INLINE void AndroidLogWrite(const char *buffer_unused) {}
    686 INLINE void SanitizerInitializeUnwinder() {}
    687 INLINE AndroidApiLevel AndroidGetApiLevel() { return ANDROID_NOT_ANDROID; }
    688 #endif
    689 
    690 INLINE uptr GetPthreadDestructorIterations() {
    691 #if SANITIZER_ANDROID
    692   return (AndroidGetApiLevel() == ANDROID_LOLLIPOP_MR1) ? 8 : 4;
    693 #elif SANITIZER_POSIX
    694   return 4;
    695 #else
    696 // Unused on Windows.
    697   return 0;
    698 #endif
    699 }
    700 
    701 void *internal_start_thread(void(*func)(void*), void *arg);
    702 void internal_join_thread(void *th);
    703 void MaybeStartBackgroudThread();
    704 
    705 // Make the compiler think that something is going on there.
    706 // Use this inside a loop that looks like memset/memcpy/etc to prevent the
    707 // compiler from recognising it and turning it into an actual call to
    708 // memset/memcpy/etc.
    709 static inline void SanitizerBreakOptimization(void *arg) {
    710 #if _MSC_VER && !defined(__clang__)
    711   _ReadWriteBarrier();
    712 #else
    713   __asm__ __volatile__("" : : "r" (arg) : "memory");
    714 #endif
    715 }
    716 
    717 struct SignalContext {
    718   void *context;
    719   uptr addr;
    720   uptr pc;
    721   uptr sp;
    722   uptr bp;
    723 
    724   SignalContext(void *context, uptr addr, uptr pc, uptr sp, uptr bp) :
    725       context(context), addr(addr), pc(pc), sp(sp), bp(bp) {
    726   }
    727 
    728   // Creates signal context in a platform-specific manner.
    729   static SignalContext Create(void *siginfo, void *context);
    730 };
    731 
    732 void GetPcSpBp(void *context, uptr *pc, uptr *sp, uptr *bp);
    733 
    734 void DisableReexec();
    735 void MaybeReexec();
    736 
    737 }  // namespace __sanitizer
    738 
    739 inline void *operator new(__sanitizer::operator_new_size_type size,
    740                           __sanitizer::LowLevelAllocator &alloc) {
    741   return alloc.Allocate(size);
    742 }
    743 
    744 struct StackDepotStats {
    745   uptr n_uniq_ids;
    746   uptr allocated;
    747 };
    748 
    749 #endif  // SANITIZER_COMMON_H
    750