V8 Cygwin patch

15 years ago · 9a6d2c35a1
7 changed files with 1832 additions and 3 deletions
--- a/deps/v8/0001-Patch-for-Cygwin.patch
+++ b/deps/v8/0001-Patch-for-Cygwin.patch
@ -0,0 +1,964 @@
 From 9bf51816bed45ef41d3e5e54bedcb0c8d01384e8 Mon Sep 17 00:00:00 2001
 From: unknown <cyg_server@.(none)>
 Date: Wed, 8 Sep 2010 14:57:59 -0700
 Subject: [PATCH] Patch for Cygwin
 ---
 SConstruct             |    3 +-
 src/SConscript         |    1 +
 src/platform-cygwin.cc |  858 ++++++++++++++++++++++++++++++++++++++++++++++++
 src/platform.h         |    5 +
 src/utils.h            |    2 +-
 tools/utils.py         |    2 +
 6 files changed, 868 insertions(+), 3 deletions(-)
 create mode 100644 src/platform-cygwin.cc
 diff --git a/SConstruct b/SConstruct
 index 2a39583..9328699 100644
 --- a/SConstruct
 +++ b/SConstruct
@@ -292,7 +292,6 @@ V8_EXTRA_FLAGS = {
   'gcc': {
     'all': {
       'WARNINGFLAGS': ['-Wall',
 -                       '-Werror',
                        '-W',
                        '-Wno-unused-parameter',
                        '-Wnon-virtual-dtor']
@@ -666,7 +665,7 @@ SIMPLE_OPTIONS = {
     'help': 'the toolchain to use (' + TOOLCHAIN_GUESS + ')'
   },
   'os': {
 -    'values': ['freebsd', 'linux', 'macos', 'win32', 'android', 'openbsd', 'solaris'],
 +    'values': ['freebsd', 'linux', 'macos', 'win32', 'android', 'openbsd', 'solaris', 'cygwin'],
     'default': OS_GUESS,
     'help': 'the os to build for (' + OS_GUESS + ')'
   },
 diff --git a/src/SConscript b/src/SConscript
 index 7fae8d4..e2b01aa 100755
 --- a/src/SConscript
 +++ b/src/SConscript
@@ -202,6 +202,7 @@ SOURCES = {
   'os:android': ['platform-linux.cc', 'platform-posix.cc'],
   'os:macos':   ['platform-macos.cc', 'platform-posix.cc'],
   'os:solaris': ['platform-solaris.cc', 'platform-posix.cc'],
 +  'os:cygwin':  ['platform-cygwin.cc', 'platform-posix.cc'],
   'os:nullos':  ['platform-nullos.cc'],
   'os:win32':   ['platform-win32.cc'],
   'mode:release': [],
 diff --git a/src/platform-cygwin.cc b/src/platform-cygwin.cc
 new file mode 100644
 index 0000000..34410e8
 --- /dev/null
 +++ b/src/platform-cygwin.cc
@@ -0,0 +1,858 @@
 +// Copyright 2006-2008 the V8 project authors. All rights reserved.
 +// Redistribution and use in source and binary forms, with or without
 +// modification, are permitted provided that the following conditions are
 +// met:
 +//
 +//     * Redistributions of source code must retain the above copyright
 +//       notice, this list of conditions and the following disclaimer.
 +//     * Redistributions in binary form must reproduce the above
 +//       copyright notice, this list of conditions and the following
 +//       disclaimer in the documentation and/or other materials provided
 +//       with the distribution.
 +//     * Neither the name of Google Inc. nor the names of its
 +//       contributors may be used to endorse or promote products derived
 +//       from this software without specific prior written permission.
 +//
 +// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 +// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 +// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
 +// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
 +// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 +// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
 +// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 +// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 +// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 +// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 +// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 +
 +// Platform specific code for Cygwin goes here. For the POSIX comaptible parts
 +// the implementation is in platform-posix.cc.
 +
 +#include <pthread.h>
 +#include <semaphore.h>
 +#include <signal.h>
 +#include <sys/time.h>
 +#include <sys/resource.h>
 +#include <sys/types.h>
 +#include <stdlib.h>
 +
 +// Ubuntu Dapper requires memory pages to be marked as
 +// executable. Otherwise, OS raises an exception when executing code
 +// in that page.
 +#include <sys/types.h>  // mmap & munmap
 +#include <sys/mman.h>   // mmap & munmap
 +#include <sys/stat.h>   // open
 +#include <fcntl.h>      // open
 +#include <unistd.h>     // sysconf
 +#ifdef __GLIBC__
 +#include <execinfo.h>   // backtrace, backtrace_symbols
 +#endif  // def __GLIBC__
 +#include <strings.h>    // index
 +#include <errno.h>
 +#include <stdarg.h>
 +
 +#undef MAP_TYPE
 +
 +#include "v8.h"
 +
 +#include "platform.h"
 +#include "top.h"
 +#include "v8threads.h"
 +
 +
 +namespace v8 {
 +namespace internal {
 +
 +// 0 is never a valid thread id on Linux since tids and pids share a
 +// name space and pid 0 is reserved (see man 2 kill).
 +static const pthread_t kNoThread = (pthread_t) 0;
 +
 +
 +double ceiling(double x) {
 +  return ceil(x);
 +}
 +
 +
 +void OS::Setup() {
 +  // Seed the random number generator.
 +  // Convert the current time to a 64-bit integer first, before converting it
 +  // to an unsigned. Going directly can cause an overflow and the seed to be
 +  // set to all ones. The seed will be identical for different instances that
 +  // call this setup code within the same millisecond.
 +  uint64_t seed = static_cast<uint64_t>(TimeCurrentMillis());
 +  srandom(static_cast<unsigned int>(seed));
 +}
 +
 +
 +uint64_t OS::CpuFeaturesImpliedByPlatform() {
 +#if (defined(__VFP_FP__) && !defined(__SOFTFP__))
 +  // Here gcc is telling us that we are on an ARM and gcc is assuming that we
 +  // have VFP3 instructions.  If gcc can assume it then so can we.
 +  return 1u << VFP3;
 +#elif CAN_USE_ARMV7_INSTRUCTIONS
 +  return 1u << ARMv7;
 +#else
 +  return 0;  // Linux runs on anything.
 +#endif
 +}
 +
 +
 +#ifdef __arm__
 +bool OS::ArmCpuHasFeature(CpuFeature feature) {
 +  const char* search_string = NULL;
 +  const char* file_name = "/proc/cpuinfo";
 +  // Simple detection of VFP at runtime for Linux.
 +  // It is based on /proc/cpuinfo, which reveals hardware configuration
 +  // to user-space applications.  According to ARM (mid 2009), no similar
 +  // facility is universally available on the ARM architectures,
 +  // so it's up to individual OSes to provide such.
 +  //
 +  // This is written as a straight shot one pass parser
 +  // and not using STL string and ifstream because,
 +  // on Linux, it's reading from a (non-mmap-able)
 +  // character special device.
 +  switch (feature) {
 +    case VFP3:
 +      search_string = "vfp";
 +      break;
 +    case ARMv7:
 +      search_string = "ARMv7";
 +      break;
 +    default:
 +      UNREACHABLE();
 +  }
 +
 +  FILE* f = NULL;
 +  const char* what = search_string;
 +
 +  if (NULL == (f = fopen(file_name, "r")))
 +    return false;
 +
 +  int k;
 +  while (EOF != (k = fgetc(f))) {
 +    if (k == *what) {
 +      ++what;
 +      while ((*what != '\0') && (*what == fgetc(f))) {
 +        ++what;
 +      }
 +      if (*what == '\0') {
 +        fclose(f);
 +        return true;
 +      } else {
 +        what = search_string;
 +      }
 +    }
 +  }
 +  fclose(f);
 +
 +  // Did not find string in the proc file.
 +  return false;
 +}
 +#endif  // def __arm__
 +
 +
 +int OS::ActivationFrameAlignment() {
 +#ifdef V8_TARGET_ARCH_ARM
 +  // On EABI ARM targets this is required for fp correctness in the
 +  // runtime system.
 +  return 8;
 +#elif V8_TARGET_ARCH_MIPS
 +  return 8;
 +#endif
 +  // With gcc 4.4 the tree vectorization optimizer can generate code
 +  // that requires 16 byte alignment such as movdqa on x86.
 +  return 16;
 +}
 +
 +void OS::ReleaseStore(volatile AtomicWord* ptr, AtomicWord value) {
 +  __asm__ __volatile__("" : : : "memory");
 +  // An x86 store acts as a release barrier.
 +  *ptr = value;
 +}
 +
 +const char* OS::LocalTimezone(double time) {
 +  if (isnan(time)) return "";
 +  time_t tv = static_cast<time_t>(floor(time/msPerSecond));
 +  struct tm* t = localtime(&tv);
 +  if (NULL == t) return "";
 +  return tzname[0];  // The location of the timezone string on Cywin.
 +}
 +
 +
 +double OS::LocalTimeOffset() {
 +  //
 +  // On Cygwin, struct tm does not contain a tm_gmtoff field.
 +  time_t utc = time(NULL);
 +  ASSERT(utc != -1);
 +  struct tm* loc = localtime(&utc);
 +  ASSERT(loc != NULL);
 +  return static_cast<double>((mktime(loc) - utc) * msPerSecond);
 +}
 +
 +
 +// We keep the lowest and highest addresses mapped as a quick way of
 +// determining that pointers are outside the heap (used mostly in assertions
 +// and verification).  The estimate is conservative, ie, not all addresses in
 +// 'allocated' space are actually allocated to our heap.  The range is
 +// [lowest, highest), inclusive on the low and and exclusive on the high end.
 +static void* lowest_ever_allocated = reinterpret_cast<void*>(-1);
 +static void* highest_ever_allocated = reinterpret_cast<void*>(0);
 +
 +
 +static void UpdateAllocatedSpaceLimits(void* address, int size) {
 +  lowest_ever_allocated = Min(lowest_ever_allocated, address);
 +  highest_ever_allocated =
 +      Max(highest_ever_allocated,
 +          reinterpret_cast<void*>(reinterpret_cast<char*>(address) + size));
 +}
 +
 +
 +bool OS::IsOutsideAllocatedSpace(void* address) {
 +  return address < lowest_ever_allocated || address >= highest_ever_allocated;
 +}
 +
 +
 +size_t OS::AllocateAlignment() {
 +  return sysconf(_SC_PAGESIZE);
 +}
 +
 +
 +void* OS::Allocate(const size_t requested,
 +                   size_t* allocated,
 +                   bool is_executable) {
 +  const size_t msize = RoundUp(requested, sysconf(_SC_PAGESIZE));
 +  int prot = PROT_READ | PROT_WRITE | (is_executable ? PROT_EXEC : 0);
 +  void* mbase = mmap(NULL, msize, prot, MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
 +  if (mbase == MAP_FAILED) {
 +    LOG(StringEvent("OS::Allocate", "mmap failed"));
 +    return NULL;
 +  }
 +  *allocated = msize;
 +  UpdateAllocatedSpaceLimits(mbase, msize);
 +  return mbase;
 +}
 +
 +
 +void OS::Free(void* address, const size_t size) {
 +  // TODO(1240712): munmap has a return value which is ignored here.
 +  int result = munmap(address, size);
 +  USE(result);
 +  ASSERT(result == 0);
 +}
 +
 +
 +#ifdef ENABLE_HEAP_PROTECTION
 +
 +void OS::Protect(void* address, size_t size) {
 +  // TODO(1240712): mprotect has a return value which is ignored here.
 +  mprotect(address, size, PROT_READ);
 +}
 +
 +
 +void OS::Unprotect(void* address, size_t size, bool is_executable) {
 +  // TODO(1240712): mprotect has a return value which is ignored here.
 +  int prot = PROT_READ | PROT_WRITE | (is_executable ? PROT_EXEC : 0);
 +  mprotect(address, size, prot);
 +}
 +
 +#endif
 +
 +
 +void OS::Sleep(int milliseconds) {
 +  unsigned int ms = static_cast<unsigned int>(milliseconds);
 +  usleep(1000 * ms);
 +}
 +
 +
 +void OS::Abort() {
 +  // Redirect to std abort to signal abnormal program termination.
 +  abort();
 +}
 +
 +
 +void OS::DebugBreak() {
 +// TODO(lrn): Introduce processor define for runtime system (!= V8_ARCH_x,
 +//  which is the architecture of generated code).
 +#if (defined(__arm__) || defined(__thumb__)) && \
 +    defined(CAN_USE_ARMV5_INSTRUCTIONS)
 +  asm("bkpt 0");
 +#elif defined(__mips__)
 +  asm("break");
 +#else
 +  asm("int $3");
 +#endif
 +}
 +
 +
 +class PosixMemoryMappedFile : public OS::MemoryMappedFile {
 + public:
 +  PosixMemoryMappedFile(FILE* file, void* memory, int size)
 +    : file_(file), memory_(memory), size_(size) { }
 +  virtual ~PosixMemoryMappedFile();
 +  virtual void* memory() { return memory_; }
 + private:
 +  FILE* file_;
 +  void* memory_;
 +  int size_;
 +};
 +
 +
 +OS::MemoryMappedFile* OS::MemoryMappedFile::create(const char* name, int size,
 +    void* initial) {
 +  FILE* file = fopen(name, "w+");
 +  if (file == NULL) return NULL;
 +  int result = fwrite(initial, size, 1, file);
 +  if (result < 1) {
 +    fclose(file);
 +    return NULL;
 +  }
 +  void* memory =
 +      mmap(0, size, PROT_READ | PROT_WRITE, MAP_SHARED, fileno(file), 0);
 +  return new PosixMemoryMappedFile(file, memory, size);
 +}
 +
 +
 +PosixMemoryMappedFile::~PosixMemoryMappedFile() {
 +  if (memory_) munmap(memory_, size_);
 +  fclose(file_);
 +}
 +
 +
 +void OS::LogSharedLibraryAddresses() {
 +#ifdef ENABLE_LOGGING_AND_PROFILING
 +  // This function assumes that the layout of the file is as follows:
 +  // hex_start_addr-hex_end_addr rwxp <unused data> [binary_file_name]
 +  // If we encounter an unexpected situation we abort scanning further entries.
 +  FILE* fp = fopen("/proc/self/maps", "r");
 +  if (fp == NULL) return;
 +
 +  // Allocate enough room to be able to store a full file name.
 +  const int kLibNameLen = FILENAME_MAX + 1;
 +  char* lib_name = reinterpret_cast<char*>(malloc(kLibNameLen));
 +
 +  // This loop will terminate once the scanning hits an EOF.
 +  while (true) {
 +    uintptr_t start, end;
 +    char attr_r, attr_w, attr_x, attr_p;
 +    // Parse the addresses and permission bits at the beginning of the line.
 +    if (fscanf(fp, "%" V8PRIxPTR "-%" V8PRIxPTR, &start, &end) != 2) break;
 +    if (fscanf(fp, " %c%c%c%c", &attr_r, &attr_w, &attr_x, &attr_p) != 4) break;
 +
 +    int c;
 +    if (attr_r == 'r' && attr_w != 'w' && attr_x == 'x') {
 +      // Found a read-only executable entry. Skip characters until we reach
 +      // the beginning of the filename or the end of the line.
 +      do {
 +        c = getc(fp);
 +      } while ((c != EOF) && (c != '\n') && (c != '/'));
 +      if (c == EOF) break;  // EOF: Was unexpected, just exit.
 +
 +      // Process the filename if found.
 +      if (c == '/') {
 +        ungetc(c, fp);  // Push the '/' back into the stream to be read below.
 +
 +        // Read to the end of the line. Exit if the read fails.
 +        if (fgets(lib_name, kLibNameLen, fp) == NULL) break;
 +
 +        // Drop the newline character read by fgets. We do not need to check
 +        // for a zero-length string because we know that we at least read the
 +        // '/' character.
 +        lib_name[strlen(lib_name) - 1] = '\0';
 +      } else {
 +        // No library name found, just record the raw address range.
 +        snprintf(lib_name, kLibNameLen,
 +                 "%08" V8PRIxPTR "-%08" V8PRIxPTR, start, end);
 +      }
 +      LOG(SharedLibraryEvent(lib_name, start, end));
 +    } else {
 +      // Entry not describing executable data. Skip to end of line to setup
 +      // reading the next entry.
 +      do {
 +        c = getc(fp);
 +      } while ((c != EOF) && (c != '\n'));
 +      if (c == EOF) break;
 +    }
 +  }
 +  free(lib_name);
 +  fclose(fp);
 +#endif
 +}
 +
 +
 +int OS::StackWalk(Vector<OS::StackFrame> frames) {
 +  // backtrace is a glibc extension.
 +#ifdef __GLIBC__
 +  int frames_size = frames.length();
 +  ScopedVector<void*> addresses(frames_size);
 +
 +  int frames_count = backtrace(addresses.start(), frames_size);
 +
 +  char** symbols = backtrace_symbols(addresses.start(), frames_count);
 +  if (symbols == NULL) {
 +    return kStackWalkError;
 +  }
 +
 +  for (int i = 0; i < frames_count; i++) {
 +    frames[i].address = addresses[i];
 +    // Format a text representation of the frame based on the information
 +    // available.
 +    SNPrintF(MutableCStrVector(frames[i].text, kStackWalkMaxTextLen),
 +             "%s",
 +             symbols[i]);
 +    // Make sure line termination is in place.
 +    frames[i].text[kStackWalkMaxTextLen - 1] = '\0';
 +  }
 +
 +  free(symbols);
 +
 +  return frames_count;
 +#else  // ndef __GLIBC__
 +  return 0;
 +#endif  // ndef __GLIBC__
 +}
 +
 +
 +// Constants used for mmap.
 +static const int kMmapFd = -1;
 +static const int kMmapFdOffset = 0;
 +
 +
 +VirtualMemory::VirtualMemory(size_t size) {
 +  address_ = mmap(NULL, size, PROT_NONE,
 +                  MAP_PRIVATE | MAP_ANONYMOUS | MAP_NORESERVE,
 +                  kMmapFd, kMmapFdOffset);
 +  size_ = size;
 +}
 +
 +
 +VirtualMemory::~VirtualMemory() {
 +  if (IsReserved()) {
 +    if (0 == munmap(address(), size())) address_ = MAP_FAILED;
 +  }
 +}
 +
 +
 +bool VirtualMemory::IsReserved() {
 +  return address_ != MAP_FAILED;
 +}
 +
 +
 +bool VirtualMemory::Commit(void* address, size_t size, bool is_executable) {
 +  int prot = PROT_READ | PROT_WRITE | (is_executable ? PROT_EXEC : 0);
 +
 +#ifdef HAS_MAP_FIXED
 +  if (MAP_FAILED == mmap(address, size, prot,
 +                         MAP_PRIVATE | MAP_ANONYMOUS, // | MAP_FIXED, - Cygwin doesn't have MAP_FIXED
 +                         kMmapFd, kMmapFdOffset)) {
 +    return false;
 +  }
 +#else
 +  if (mprotect(address, size, prot) != 0) {
 +    return false;
 +  }
 +#endif
 +
 +  UpdateAllocatedSpaceLimits(address, size);
 +  return true;
 +}
 +
 +
 +bool VirtualMemory::Uncommit(void* address, size_t size) {
 +  return mmap(address, size, PROT_NONE,
 +              MAP_PRIVATE | MAP_ANONYMOUS | MAP_NORESERVE, // | MAP_FIXED, - Cygwin doesn't have MAP_FIXED
 +              kMmapFd, kMmapFdOffset) != MAP_FAILED;
 +}
 +
 +
 +class ThreadHandle::PlatformData : public Malloced {
 + public:
 +  explicit PlatformData(ThreadHandle::Kind kind) {
 +    Initialize(kind);
 +  }
 +
 +  void Initialize(ThreadHandle::Kind kind) {
 +    switch (kind) {
 +      case ThreadHandle::SELF: thread_ = pthread_self(); break;
 +      case ThreadHandle::INVALID: thread_ = kNoThread; break;
 +    }
 +  }
 +
 +  pthread_t thread_;  // Thread handle for pthread.
 +};
 +
 +
 +ThreadHandle::ThreadHandle(Kind kind) {
 +  data_ = new PlatformData(kind);
 +}
 +
 +
 +void ThreadHandle::Initialize(ThreadHandle::Kind kind) {
 +  data_->Initialize(kind);
 +}
 +
 +
 +ThreadHandle::~ThreadHandle() {
 +  delete data_;
 +}
 +
 +
 +bool ThreadHandle::IsSelf() const {
 +  return pthread_equal(data_->thread_, pthread_self());
 +}
 +
 +
 +bool ThreadHandle::IsValid() const {
 +  return data_->thread_ != kNoThread;
 +}
 +
 +
 +Thread::Thread() : ThreadHandle(ThreadHandle::INVALID) {
 +}
 +
 +
 +Thread::~Thread() {
 +}
 +
 +
 +static void* ThreadEntry(void* arg) {
 +  Thread* thread = reinterpret_cast<Thread*>(arg);
 +  // This is also initialized by the first argument to pthread_create() but we
 +  // don't know which thread will run first (the original thread or the new
 +  // one) so we initialize it here too.
 +  thread->thread_handle_data()->thread_ = pthread_self();
 +  ASSERT(thread->IsValid());
 +  thread->Run();
 +  return NULL;
 +}
 +
 +
 +void Thread::Start() {
 +  pthread_create(&thread_handle_data()->thread_, NULL, ThreadEntry, this);
 +  ASSERT(IsValid());
 +}
 +
 +
 +void Thread::Join() {
 +  pthread_join(thread_handle_data()->thread_, NULL);
 +}
 +
 +
 +Thread::LocalStorageKey Thread::CreateThreadLocalKey() {
 +  pthread_key_t key;
 +  int result = pthread_key_create(&key, NULL);
 +  USE(result);
 +  ASSERT(result == 0);
 +  return static_cast<LocalStorageKey>(key);
 +}
 +
 +
 +void Thread::DeleteThreadLocalKey(LocalStorageKey key) {
 +  pthread_key_t pthread_key = static_cast<pthread_key_t>(key);
 +  int result = pthread_key_delete(pthread_key);
 +  USE(result);
 +  ASSERT(result == 0);
 +}
 +
 +
 +void* Thread::GetThreadLocal(LocalStorageKey key) {
 +  pthread_key_t pthread_key = static_cast<pthread_key_t>(key);
 +  return pthread_getspecific(pthread_key);
 +}
 +
 +
 +void Thread::SetThreadLocal(LocalStorageKey key, void* value) {
 +  pthread_key_t pthread_key = static_cast<pthread_key_t>(key);
 +  pthread_setspecific(pthread_key, value);
 +}
 +
 +
 +void Thread::YieldCPU() {
 +  sched_yield();
 +}
 +
 +
 +class CygwinMutex : public Mutex {
 + public:
 +
 +  CygwinMutex() {
 +    pthread_mutexattr_t attrs;
 +    memset(&attrs, 0, sizeof(attrs));
 +
 +    int result = pthread_mutexattr_init(&attrs);
 +    ASSERT(result == 0);
 +    result = pthread_mutexattr_settype(&attrs, PTHREAD_MUTEX_RECURSIVE);
 +    ASSERT(result == 0);
 +    result = pthread_mutex_init(&mutex_, &attrs);
 +    ASSERT(result == 0);
 +  }
 +
 +  virtual ~CygwinMutex() { pthread_mutex_destroy(&mutex_); }
 +
 +  virtual int Lock() {
 +    int result = pthread_mutex_lock(&mutex_);
 +    return result;
 +  }
 +
 +  virtual int Unlock() {
 +    int result = pthread_mutex_unlock(&mutex_);
 +    return result;
 +  }
 +
 + private:
 +  pthread_mutex_t mutex_;   // Pthread mutex for POSIX platforms.
 +};
 +
 +
 +Mutex* OS::CreateMutex() {
 +  return new CygwinMutex();
 +}
 +
 +
 +class CygwinSemaphore : public Semaphore {
 + public:
 +  explicit CygwinSemaphore(int count) {  sem_init(&sem_, 0, count); }
 +  virtual ~CygwinSemaphore() { sem_destroy(&sem_); }
 +
 +  virtual void Wait();
 +  virtual bool Wait(int timeout);
 +  virtual void Signal() { sem_post(&sem_); }
 + private:
 +  sem_t sem_;
 +};
 +
 +
 +void CygwinSemaphore::Wait() {
 +  while (true) {
 +    int result = sem_wait(&sem_);
 +    if (result == 0) return;  // Successfully got semaphore.
 +    CHECK(result == -1 && errno == EINTR);  // Signal caused spurious wakeup.
 +  }
 +}
 +
 +
 +#ifndef TIMEVAL_TO_TIMESPEC
 +#define TIMEVAL_TO_TIMESPEC(tv, ts) do {                            \
 +    (ts)->tv_sec = (tv)->tv_sec;                                    \
 +    (ts)->tv_nsec = (tv)->tv_usec * 1000;                           \
 +} while (false)
 +#endif
 +
 +
 +bool CygwinSemaphore::Wait(int timeout) {
 +  const long kOneSecondMicros = 1000000;  // NOLINT
 +
 +  // Split timeout into second and nanosecond parts.
 +  struct timeval delta;
 +  delta.tv_usec = timeout % kOneSecondMicros;
 +  delta.tv_sec = timeout / kOneSecondMicros;
 +
 +  struct timeval current_time;
 +  // Get the current time.
 +  if (gettimeofday(&current_time, NULL) == -1) {
 +    return false;
 +  }
 +
 +  // Calculate time for end of timeout.
 +  struct timeval end_time;
 +  timeradd(&current_time, &delta, &end_time);
 +
 +  struct timespec ts;
 +  TIMEVAL_TO_TIMESPEC(&end_time, &ts);
 +  // Wait for semaphore signalled or timeout.
 +  while (true) {
 +    int result = sem_timedwait(&sem_, &ts);
 +    if (result == 0) return true;  // Successfully got semaphore.
 +    if (result > 0) {
 +      // For glibc prior to 2.3.4 sem_timedwait returns the error instead of -1.
 +      errno = result;
 +      result = -1;
 +    }
 +    if (result == -1 && errno == ETIMEDOUT) return false;  // Timeout.
 +    CHECK(result == -1 && errno == EINTR);  // Signal caused spurious wakeup.
 +  }
 +}
 +
 +
 +Semaphore* OS::CreateSemaphore(int count) {
 +  return new CygwinSemaphore(count);
 +}
 +
 +
 +#ifdef ENABLE_LOGGING_AND_PROFILING
 +
 +static Sampler* active_sampler_ = NULL;
 +static pthread_t vm_thread_ = 0;
 +
 +
 +#if !defined(__GLIBC__) && (defined(__arm__) || defined(__thumb__))
 +// Android runs a fairly new Linux kernel, so signal info is there,
 +// but the C library doesn't have the structs defined.
 +
 +struct sigcontext {
 +  uint32_t trap_no;
 +  uint32_t error_code;
 +  uint32_t oldmask;
 +  uint32_t gregs[16];
 +  uint32_t arm_cpsr;
 +  uint32_t fault_address;
 +};
 +typedef uint32_t __sigset_t;
 +typedef struct sigcontext mcontext_t;
 +typedef struct ucontext {
 +  uint32_t uc_flags;
 +  struct ucontext* uc_link;
 +  stack_t uc_stack;
 +  mcontext_t uc_mcontext;
 +  __sigset_t uc_sigmask;
 +} ucontext_t;
 +enum ArmRegisters {R15 = 15, R13 = 13, R11 = 11};
 +
 +#endif
 +
 +
 +// A function that determines if a signal handler is called in the context
 +// of a VM thread.
 +//
 +// The problem is that SIGPROF signal can be delivered to an arbitrary thread
 +// (see http://code.google.com/p/google-perftools/issues/detail?id=106#c2)
 +// So, if the signal is being handled in the context of a non-VM thread,
 +// it means that the VM thread is running, and trying to sample its stack can
 +// cause a crash.
 +static inline bool IsVmThread() {
 +  // In the case of a single VM thread, this check is enough.
 +  if (pthread_equal(pthread_self(), vm_thread_)) return true;
 +  // If there are multiple threads that use VM, they must have a thread id
 +  // stored in TLS. To verify that the thread is really executing VM,
 +  // we check Top's data. Having that ThreadManager::RestoreThread first
 +  // restores ThreadLocalTop from TLS, and only then erases the TLS value,
 +  // reading Top::thread_id() should not be affected by races.
 +  if (ThreadManager::HasId() && !ThreadManager::IsArchived() &&
 +      ThreadManager::CurrentId() == Top::thread_id()) {
 +    return true;
 +  }
 +  return false;
 +}
 +
 +
 +static void ProfilerSignalHandler(int signal, siginfo_t* info, void* context) {
 +#ifndef V8_HOST_ARCH_MIPS
 +  USE(info);
 +  if (signal != SIGPROF) return;
 +  if (active_sampler_ == NULL) return;
 +
 +  TickSample sample_obj;
 +  TickSample* sample = CpuProfiler::TickSampleEvent();
 +  if (sample == NULL) sample = &sample_obj;
 +
 +  // We always sample the VM state.
 +  sample->state = VMState::current_state();
 +
 +#if 0
 +  // If profiling, we extract the current pc and sp.
 +  if (active_sampler_->IsProfiling()) {
 +    // Extracting the sample from the context is extremely machine dependent.
 +    ucontext_t* ucontext = reinterpret_cast<ucontext_t*>(context);
 +    mcontext_t& mcontext = ucontext->uc_mcontext;
 +#if V8_HOST_ARCH_IA32
 +    sample->pc = reinterpret_cast<Address>(mcontext.gregs[REG_EIP]);
 +    sample->sp = reinterpret_cast<Address>(mcontext.gregs[REG_ESP]);
 +    sample->fp = reinterpret_cast<Address>(mcontext.gregs[REG_EBP]);
 +#elif V8_HOST_ARCH_X64
 +    sample->pc = reinterpret_cast<Address>(mcontext.gregs[REG_RIP]);
 +    sample->sp = reinterpret_cast<Address>(mcontext.gregs[REG_RSP]);
 +    sample->fp = reinterpret_cast<Address>(mcontext.gregs[REG_RBP]);
 +#elif V8_HOST_ARCH_ARM
 +// An undefined macro evaluates to 0, so this applies to Android's Bionic also.
 +#if (__GLIBC__ < 2 || (__GLIBC__ == 2 && __GLIBC_MINOR__ <= 3))
 +    sample->pc = reinterpret_cast<Address>(mcontext.gregs[R15]);
 +    sample->sp = reinterpret_cast<Address>(mcontext.gregs[R13]);
 +    sample->fp = reinterpret_cast<Address>(mcontext.gregs[R11]);
 +#else
 +    sample->pc = reinterpret_cast<Address>(mcontext.arm_pc);
 +    sample->sp = reinterpret_cast<Address>(mcontext.arm_sp);
 +    sample->fp = reinterpret_cast<Address>(mcontext.arm_fp);
 +#endif
 +#elif V8_HOST_ARCH_MIPS
 +    // Implement this on MIPS.
 +    UNIMPLEMENTED();
 +#endif
 +    if (IsVmThread()) {
 +      active_sampler_->SampleStack(sample);
 +    }
 +  }
 +#endif
 +
 +  active_sampler_->Tick(sample);
 +#endif
 +}
 +
 +
 +class Sampler::PlatformData : public Malloced {
 + public:
 +  PlatformData() {
 +    signal_handler_installed_ = false;
 +  }
 +
 +  bool signal_handler_installed_;
 +  struct sigaction old_signal_handler_;
 +  struct itimerval old_timer_value_;
 +};
 +
 +
 +Sampler::Sampler(int interval, bool profiling)
 +    : interval_(interval), profiling_(profiling), active_(false) {
 +  data_ = new PlatformData();
 +}
 +
 +
 +Sampler::~Sampler() {
 +  delete data_;
 +}
 +
 +
 +void Sampler::Start() {
 +  // There can only be one active sampler at the time on POSIX
 +  // platforms.
 +  if (active_sampler_ != NULL) return;
 +
 +  vm_thread_ = pthread_self();
 +
 +  // Request profiling signals.
 +  struct sigaction sa;
 +  sa.sa_sigaction = ProfilerSignalHandler;
 +  sigemptyset(&sa.sa_mask);
 +  sa.sa_flags = SA_SIGINFO;
 +  if (sigaction(SIGPROF, &sa, &data_->old_signal_handler_) != 0) return;
 +  data_->signal_handler_installed_ = true;
 +
 +  // Set the itimer to generate a tick for each interval.
 +  itimerval itimer;
 +  itimer.it_interval.tv_sec = interval_ / 1000;
 +  itimer.it_interval.tv_usec = (interval_ % 1000) * 1000;
 +  itimer.it_value.tv_sec = itimer.it_interval.tv_sec;
 +  itimer.it_value.tv_usec = itimer.it_interval.tv_usec;
 +  setitimer(ITIMER_PROF, &itimer, &data_->old_timer_value_);
 +
 +  // Set this sampler as the active sampler.
 +  active_sampler_ = this;
 +  active_ = true;
 +}
 +
 +
 +void Sampler::Stop() {
 +  // Restore old signal handler
 +  if (data_->signal_handler_installed_) {
 +    setitimer(ITIMER_PROF, &data_->old_timer_value_, NULL);
 +    sigaction(SIGPROF, &data_->old_signal_handler_, 0);
 +    data_->signal_handler_installed_ = false;
 +  }
 +
 +  // This sampler is no longer the active sampler.
 +  active_sampler_ = NULL;
 +  active_ = false;
 +}
 +
 +
 +#endif  // ENABLE_LOGGING_AND_PROFILING
 +
 +} }  // namespace v8::internal
 diff --git a/src/platform.h b/src/platform.h
 index e9e7c22..f4ce29f 100644
 --- a/src/platform.h
 +++ b/src/platform.h
@@ -362,6 +362,7 @@ class ThreadHandle {
 class Thread: public ThreadHandle {
  public:
 +#ifndef __CYGWIN__
   // Opaque data type for thread-local storage keys.
   // LOCAL_STORAGE_KEY_MIN_VALUE and LOCAL_STORAGE_KEY_MAX_VALUE are specified
   // to ensure that enumeration type has correct value range (see Issue 830 for
@@ -370,6 +371,10 @@ class Thread: public ThreadHandle {
     LOCAL_STORAGE_KEY_MIN_VALUE = kMinInt,
     LOCAL_STORAGE_KEY_MAX_VALUE = kMaxInt
   };
 +#else
 +  typedef void *LocalStorageKey;
 +#endif
 +
   // Create new thread.
   Thread();
 diff --git a/src/utils.h b/src/utils.h
 index d605891..30db7ab 100644
 --- a/src/utils.h
 +++ b/src/utils.h
@@ -947,7 +947,7 @@ inline Dest BitCast(const Source& source) {
 }
 template <class Dest, class Source>
 -inline Dest BitCast(Source* source) {
 +inline Dest BitCast(Source*& source) {
   return BitCast<Dest>(reinterpret_cast<uintptr_t>(source));
 }
 diff --git a/tools/utils.py b/tools/utils.py
 index 8083091..7733157 100644
 --- a/tools/utils.py
 +++ b/tools/utils.py
@@ -59,6 +59,8 @@ def GuessOS():
     return 'openbsd'
   elif id == 'SunOS':
     return 'solaris'
 +  elif id.find('CYGWIN') >= 0:
 +    return 'cygwin'
   else:
     return None
 -- 
 1.7.2
--- a/deps/v8/SConstruct
+++ b/deps/v8/SConstruct
@ -292,7 +292,6 @@ V8_EXTRA_FLAGS = {
  'gcc': {
    'all': {
      'WARNINGFLAGS': ['-Wall',
                       '-Werror',
                       '-W',
                       '-Wno-unused-parameter',
                       '-Wnon-virtual-dtor']
@ -666,7 +665,7 @@ SIMPLE_OPTIONS = {
    'help': 'the toolchain to use (' + TOOLCHAIN_GUESS + ')'
  },
  'os': {
-    'values': ['freebsd', 'linux', 'macos', 'win32', 'android', 'openbsd', 'solaris'],
+    'values': ['freebsd', 'linux', 'macos', 'win32', 'android', 'openbsd', 'solaris', 'cygwin'],
    'default': OS_GUESS,
    'help': 'the os to build for (' + OS_GUESS + ')'
  },
--- a/deps/v8/src/SConscript
+++ b/deps/v8/src/SConscript
@ -202,6 +202,7 @@ SOURCES = {
  'os:android': ['platform-linux.cc', 'platform-posix.cc'],
  'os:macos':   ['platform-macos.cc', 'platform-posix.cc'],
  'os:solaris': ['platform-solaris.cc', 'platform-posix.cc'],
  'os:cygwin':  ['platform-cygwin.cc', 'platform-posix.cc'],
  'os:nullos':  ['platform-nullos.cc'],
  'os:win32':   ['platform-win32.cc'],
  'mode:release': [],
--- a/deps/v8/src/platform-cygwin.cc
+++ b/deps/v8/src/platform-cygwin.cc
@ -0,0 +1,858 @@
 // Copyright 2006-2008 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
 //       with the distribution.
 //     * Neither the name of Google Inc. nor the names of its
 //       contributors may be used to endorse or promote products derived
 //       from this software without specific prior written permission.
 //
 // THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 // "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 // LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
 // A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
 // OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 // SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
 // LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 // DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 // THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 // (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 // Platform specific code for Cygwin goes here. For the POSIX comaptible parts
 // the implementation is in platform-posix.cc.
 #include <pthread.h>
 #include <semaphore.h>
 #include <signal.h>
 #include <sys/time.h>
 #include <sys/resource.h>
 #include <sys/types.h>
 #include <stdlib.h>
 // Ubuntu Dapper requires memory pages to be marked as
 // executable. Otherwise, OS raises an exception when executing code
 // in that page.
 #include <sys/types.h>  // mmap & munmap
 #include <sys/mman.h>   // mmap & munmap
 #include <sys/stat.h>   // open
 #include <fcntl.h>      // open
 #include <unistd.h>     // sysconf
 #ifdef __GLIBC__
 #include <execinfo.h>   // backtrace, backtrace_symbols
 #endif  // def __GLIBC__
 #include <strings.h>    // index
 #include <errno.h>
 #include <stdarg.h>
 #undef MAP_TYPE
 #include "v8.h"
 #include "platform.h"
 #include "top.h"
 #include "v8threads.h"
 namespace v8 {
 namespace internal {
 // 0 is never a valid thread id on Linux since tids and pids share a
 // name space and pid 0 is reserved (see man 2 kill).
 static const pthread_t kNoThread = (pthread_t) 0;
 double ceiling(double x) {
  return ceil(x);
 }
 void OS::Setup() {
  // Seed the random number generator.
  // Convert the current time to a 64-bit integer first, before converting it
  // to an unsigned. Going directly can cause an overflow and the seed to be
  // set to all ones. The seed will be identical for different instances that
  // call this setup code within the same millisecond.
  uint64_t seed = static_cast<uint64_t>(TimeCurrentMillis());
  srandom(static_cast<unsigned int>(seed));
 }
 uint64_t OS::CpuFeaturesImpliedByPlatform() {
 #if (defined(__VFP_FP__) && !defined(__SOFTFP__))
  // Here gcc is telling us that we are on an ARM and gcc is assuming that we
  // have VFP3 instructions.  If gcc can assume it then so can we.
  return 1u << VFP3;
 #elif CAN_USE_ARMV7_INSTRUCTIONS
  return 1u << ARMv7;
 #else
  return 0;  // Linux runs on anything.
 #endif
 }
 #ifdef __arm__
 bool OS::ArmCpuHasFeature(CpuFeature feature) {
  const char* search_string = NULL;
  const char* file_name = "/proc/cpuinfo";
  // Simple detection of VFP at runtime for Linux.
  // It is based on /proc/cpuinfo, which reveals hardware configuration
  // to user-space applications.  According to ARM (mid 2009), no similar
  // facility is universally available on the ARM architectures,
  // so it's up to individual OSes to provide such.
  //
  // This is written as a straight shot one pass parser
  // and not using STL string and ifstream because,
  // on Linux, it's reading from a (non-mmap-able)
  // character special device.
  switch (feature) {
    case VFP3:
      search_string = "vfp";
      break;
    case ARMv7:
      search_string = "ARMv7";
      break;
    default:
      UNREACHABLE();
  }
  FILE* f = NULL;
  const char* what = search_string;
  if (NULL == (f = fopen(file_name, "r")))
    return false;
  int k;
  while (EOF != (k = fgetc(f))) {
    if (k == *what) {
      ++what;
      while ((*what != '\0') && (*what == fgetc(f))) {
        ++what;
      }
      if (*what == '\0') {
        fclose(f);
        return true;
      } else {
        what = search_string;
      }
    }
  }
  fclose(f);
  // Did not find string in the proc file.
  return false;
 }
 #endif  // def __arm__
 int OS::ActivationFrameAlignment() {
 #ifdef V8_TARGET_ARCH_ARM
  // On EABI ARM targets this is required for fp correctness in the
  // runtime system.
  return 8;
 #elif V8_TARGET_ARCH_MIPS
  return 8;
 #endif
  // With gcc 4.4 the tree vectorization optimizer can generate code
  // that requires 16 byte alignment such as movdqa on x86.
  return 16;
 }
 void OS::ReleaseStore(volatile AtomicWord* ptr, AtomicWord value) {
  __asm__ __volatile__("" : : : "memory");
  // An x86 store acts as a release barrier.
  *ptr = value;
 }
 const char* OS::LocalTimezone(double time) {
  if (isnan(time)) return "";
  time_t tv = static_cast<time_t>(floor(time/msPerSecond));
  struct tm* t = localtime(&tv);
  if (NULL == t) return "";
  return tzname[0];  // The location of the timezone string on Cywin.
 }
 double OS::LocalTimeOffset() {
  //
  // On Cygwin, struct tm does not contain a tm_gmtoff field.
  time_t utc = time(NULL);
  ASSERT(utc != -1);
  struct tm* loc = localtime(&utc);
  ASSERT(loc != NULL);
  return static_cast<double>((mktime(loc) - utc) * msPerSecond);
 }
 // We keep the lowest and highest addresses mapped as a quick way of
 // determining that pointers are outside the heap (used mostly in assertions
 // and verification).  The estimate is conservative, ie, not all addresses in
 // 'allocated' space are actually allocated to our heap.  The range is
 // [lowest, highest), inclusive on the low and and exclusive on the high end.
 static void* lowest_ever_allocated = reinterpret_cast<void*>(-1);
 static void* highest_ever_allocated = reinterpret_cast<void*>(0);
 static void UpdateAllocatedSpaceLimits(void* address, int size) {
  lowest_ever_allocated = Min(lowest_ever_allocated, address);
  highest_ever_allocated =
      Max(highest_ever_allocated,
          reinterpret_cast<void*>(reinterpret_cast<char*>(address) + size));
 }
 bool OS::IsOutsideAllocatedSpace(void* address) {
  return address < lowest_ever_allocated || address >= highest_ever_allocated;
 }
 size_t OS::AllocateAlignment() {
  return sysconf(_SC_PAGESIZE);
 }
 void* OS::Allocate(const size_t requested,
                   size_t* allocated,
                   bool is_executable) {
  const size_t msize = RoundUp(requested, sysconf(_SC_PAGESIZE));
  int prot = PROT_READ | PROT_WRITE | (is_executable ? PROT_EXEC : 0);
  void* mbase = mmap(NULL, msize, prot, MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
  if (mbase == MAP_FAILED) {
    LOG(StringEvent("OS::Allocate", "mmap failed"));
    return NULL;
  }
  *allocated = msize;
  UpdateAllocatedSpaceLimits(mbase, msize);
  return mbase;
 }
 void OS::Free(void* address, const size_t size) {
  // TODO(1240712): munmap has a return value which is ignored here.
  int result = munmap(address, size);
  USE(result);
  ASSERT(result == 0);
 }
 #ifdef ENABLE_HEAP_PROTECTION
 void OS::Protect(void* address, size_t size) {
  // TODO(1240712): mprotect has a return value which is ignored here.
  mprotect(address, size, PROT_READ);
 }
 void OS::Unprotect(void* address, size_t size, bool is_executable) {
  // TODO(1240712): mprotect has a return value which is ignored here.
  int prot = PROT_READ | PROT_WRITE | (is_executable ? PROT_EXEC : 0);
  mprotect(address, size, prot);
 }
 #endif
 void OS::Sleep(int milliseconds) {
  unsigned int ms = static_cast<unsigned int>(milliseconds);
  usleep(1000 * ms);
 }
 void OS::Abort() {
  // Redirect to std abort to signal abnormal program termination.
  abort();
 }
 void OS::DebugBreak() {
 // TODO(lrn): Introduce processor define for runtime system (!= V8_ARCH_x,
 //  which is the architecture of generated code).
 #if (defined(__arm__) || defined(__thumb__)) && \
    defined(CAN_USE_ARMV5_INSTRUCTIONS)
  asm("bkpt 0");
 #elif defined(__mips__)
  asm("break");
 #else
  asm("int $3");
 #endif
 }
 class PosixMemoryMappedFile : public OS::MemoryMappedFile {
 public:
  PosixMemoryMappedFile(FILE* file, void* memory, int size)
    : file_(file), memory_(memory), size_(size) { }
  virtual ~PosixMemoryMappedFile();
  virtual void* memory() { return memory_; }
 private:
  FILE* file_;
  void* memory_;
  int size_;
 };
 OS::MemoryMappedFile* OS::MemoryMappedFile::create(const char* name, int size,
    void* initial) {
  FILE* file = fopen(name, "w+");
  if (file == NULL) return NULL;
  int result = fwrite(initial, size, 1, file);
  if (result < 1) {
    fclose(file);
    return NULL;
  }
  void* memory =
      mmap(0, size, PROT_READ | PROT_WRITE, MAP_SHARED, fileno(file), 0);
  return new PosixMemoryMappedFile(file, memory, size);
 }
 PosixMemoryMappedFile::~PosixMemoryMappedFile() {
  if (memory_) munmap(memory_, size_);
  fclose(file_);
 }
 void OS::LogSharedLibraryAddresses() {
 #ifdef ENABLE_LOGGING_AND_PROFILING
  // This function assumes that the layout of the file is as follows:
  // hex_start_addr-hex_end_addr rwxp <unused data> [binary_file_name]
  // If we encounter an unexpected situation we abort scanning further entries.
  FILE* fp = fopen("/proc/self/maps", "r");
  if (fp == NULL) return;
  // Allocate enough room to be able to store a full file name.
  const int kLibNameLen = FILENAME_MAX + 1;
  char* lib_name = reinterpret_cast<char*>(malloc(kLibNameLen));
  // This loop will terminate once the scanning hits an EOF.
  while (true) {
    uintptr_t start, end;
    char attr_r, attr_w, attr_x, attr_p;
    // Parse the addresses and permission bits at the beginning of the line.
    if (fscanf(fp, "%" V8PRIxPTR "-%" V8PRIxPTR, &start, &end) != 2) break;
    if (fscanf(fp, " %c%c%c%c", &attr_r, &attr_w, &attr_x, &attr_p) != 4) break;
    int c;
    if (attr_r == 'r' && attr_w != 'w' && attr_x == 'x') {
      // Found a read-only executable entry. Skip characters until we reach
      // the beginning of the filename or the end of the line.
      do {
        c = getc(fp);
      } while ((c != EOF) && (c != '\n') && (c != '/'));
      if (c == EOF) break;  // EOF: Was unexpected, just exit.
      // Process the filename if found.
      if (c == '/') {
        ungetc(c, fp);  // Push the '/' back into the stream to be read below.
        // Read to the end of the line. Exit if the read fails.
        if (fgets(lib_name, kLibNameLen, fp) == NULL) break;
        // Drop the newline character read by fgets. We do not need to check
        // for a zero-length string because we know that we at least read the
        // '/' character.
        lib_name[strlen(lib_name) - 1] = '\0';
      } else {
        // No library name found, just record the raw address range.
        snprintf(lib_name, kLibNameLen,
                 "%08" V8PRIxPTR "-%08" V8PRIxPTR, start, end);
      }
      LOG(SharedLibraryEvent(lib_name, start, end));
    } else {
      // Entry not describing executable data. Skip to end of line to setup
      // reading the next entry.
      do {
        c = getc(fp);
      } while ((c != EOF) && (c != '\n'));
      if (c == EOF) break;
    }
  }
  free(lib_name);
  fclose(fp);
 #endif
 }
 int OS::StackWalk(Vector<OS::StackFrame> frames) {
  // backtrace is a glibc extension.
 #ifdef __GLIBC__
  int frames_size = frames.length();
  ScopedVector<void*> addresses(frames_size);
  int frames_count = backtrace(addresses.start(), frames_size);
  char** symbols = backtrace_symbols(addresses.start(), frames_count);
  if (symbols == NULL) {
    return kStackWalkError;
  }
  for (int i = 0; i < frames_count; i++) {
    frames[i].address = addresses[i];
    // Format a text representation of the frame based on the information
    // available.
    SNPrintF(MutableCStrVector(frames[i].text, kStackWalkMaxTextLen),
             "%s",
             symbols[i]);
    // Make sure line termination is in place.
    frames[i].text[kStackWalkMaxTextLen - 1] = '\0';
  }
  free(symbols);
  return frames_count;
 #else  // ndef __GLIBC__
  return 0;
 #endif  // ndef __GLIBC__
 }
 // Constants used for mmap.
 static const int kMmapFd = -1;
 static const int kMmapFdOffset = 0;
 VirtualMemory::VirtualMemory(size_t size) {
  address_ = mmap(NULL, size, PROT_NONE,
                  MAP_PRIVATE | MAP_ANONYMOUS | MAP_NORESERVE,
                  kMmapFd, kMmapFdOffset);
  size_ = size;
 }
 VirtualMemory::~VirtualMemory() {
  if (IsReserved()) {
    if (0 == munmap(address(), size())) address_ = MAP_FAILED;
  }
 }
 bool VirtualMemory::IsReserved() {
  return address_ != MAP_FAILED;
 }
 bool VirtualMemory::Commit(void* address, size_t size, bool is_executable) {
  int prot = PROT_READ | PROT_WRITE | (is_executable ? PROT_EXEC : 0);
 #ifdef HAS_MAP_FIXED
  if (MAP_FAILED == mmap(address, size, prot,
                         MAP_PRIVATE | MAP_ANONYMOUS, // | MAP_FIXED, - Cygwin doesn't have MAP_FIXED
                         kMmapFd, kMmapFdOffset)) {
    return false;
  }
 #else
  if (mprotect(address, size, prot) != 0) {
    return false;
  }
 #endif
  UpdateAllocatedSpaceLimits(address, size);
  return true;
 }
 bool VirtualMemory::Uncommit(void* address, size_t size) {
  return mmap(address, size, PROT_NONE,
              MAP_PRIVATE | MAP_ANONYMOUS | MAP_NORESERVE, // | MAP_FIXED, - Cygwin doesn't have MAP_FIXED
              kMmapFd, kMmapFdOffset) != MAP_FAILED;
 }
 class ThreadHandle::PlatformData : public Malloced {
 public:
  explicit PlatformData(ThreadHandle::Kind kind) {
    Initialize(kind);
  }
  void Initialize(ThreadHandle::Kind kind) {
    switch (kind) {
      case ThreadHandle::SELF: thread_ = pthread_self(); break;
      case ThreadHandle::INVALID: thread_ = kNoThread; break;
    }
  }
  pthread_t thread_;  // Thread handle for pthread.
 };
 ThreadHandle::ThreadHandle(Kind kind) {
  data_ = new PlatformData(kind);
 }
 void ThreadHandle::Initialize(ThreadHandle::Kind kind) {
  data_->Initialize(kind);
 }
 ThreadHandle::~ThreadHandle() {
  delete data_;
 }
 bool ThreadHandle::IsSelf() const {
  return pthread_equal(data_->thread_, pthread_self());
 }
 bool ThreadHandle::IsValid() const {
  return data_->thread_ != kNoThread;
 }
 Thread::Thread() : ThreadHandle(ThreadHandle::INVALID) {
 }
 Thread::~Thread() {
 }
 static void* ThreadEntry(void* arg) {
  Thread* thread = reinterpret_cast<Thread*>(arg);
  // This is also initialized by the first argument to pthread_create() but we
  // don't know which thread will run first (the original thread or the new
  // one) so we initialize it here too.
  thread->thread_handle_data()->thread_ = pthread_self();
  ASSERT(thread->IsValid());
  thread->Run();
  return NULL;
 }
 void Thread::Start() {
  pthread_create(&thread_handle_data()->thread_, NULL, ThreadEntry, this);
  ASSERT(IsValid());
 }
 void Thread::Join() {
  pthread_join(thread_handle_data()->thread_, NULL);
 }
 Thread::LocalStorageKey Thread::CreateThreadLocalKey() {
  pthread_key_t key;
  int result = pthread_key_create(&key, NULL);
  USE(result);
  ASSERT(result == 0);
  return static_cast<LocalStorageKey>(key);
 }
 void Thread::DeleteThreadLocalKey(LocalStorageKey key) {
  pthread_key_t pthread_key = static_cast<pthread_key_t>(key);
  int result = pthread_key_delete(pthread_key);
  USE(result);
  ASSERT(result == 0);
 }
 void* Thread::GetThreadLocal(LocalStorageKey key) {
  pthread_key_t pthread_key = static_cast<pthread_key_t>(key);
  return pthread_getspecific(pthread_key);
 }
 void Thread::SetThreadLocal(LocalStorageKey key, void* value) {
  pthread_key_t pthread_key = static_cast<pthread_key_t>(key);
  pthread_setspecific(pthread_key, value);
 }
 void Thread::YieldCPU() {
  sched_yield();
 }
 class CygwinMutex : public Mutex {
 public:
  CygwinMutex() {
    pthread_mutexattr_t attrs;
    memset(&attrs, 0, sizeof(attrs));
    int result = pthread_mutexattr_init(&attrs);
    ASSERT(result == 0);
    result = pthread_mutexattr_settype(&attrs, PTHREAD_MUTEX_RECURSIVE);
    ASSERT(result == 0);
    result = pthread_mutex_init(&mutex_, &attrs);
    ASSERT(result == 0);
  }
  virtual ~CygwinMutex() { pthread_mutex_destroy(&mutex_); }
  virtual int Lock() {
    int result = pthread_mutex_lock(&mutex_);
    return result;
  }
  virtual int Unlock() {
    int result = pthread_mutex_unlock(&mutex_);
    return result;
  }
 private:
  pthread_mutex_t mutex_;   // Pthread mutex for POSIX platforms.
 };
 Mutex* OS::CreateMutex() {
  return new CygwinMutex();
 }
 class CygwinSemaphore : public Semaphore {
 public:
  explicit CygwinSemaphore(int count) {  sem_init(&sem_, 0, count); }
  virtual ~CygwinSemaphore() { sem_destroy(&sem_); }
  virtual void Wait();
  virtual bool Wait(int timeout);
  virtual void Signal() { sem_post(&sem_); }
 private:
  sem_t sem_;
 };
 void CygwinSemaphore::Wait() {
  while (true) {
    int result = sem_wait(&sem_);
    if (result == 0) return;  // Successfully got semaphore.
    CHECK(result == -1 && errno == EINTR);  // Signal caused spurious wakeup.
  }
 }
 #ifndef TIMEVAL_TO_TIMESPEC
 #define TIMEVAL_TO_TIMESPEC(tv, ts) do {                            \
    (ts)->tv_sec = (tv)->tv_sec;                                    \
    (ts)->tv_nsec = (tv)->tv_usec * 1000;                           \
 } while (false)
 #endif
 bool CygwinSemaphore::Wait(int timeout) {
  const long kOneSecondMicros = 1000000;  // NOLINT
  // Split timeout into second and nanosecond parts.
  struct timeval delta;
  delta.tv_usec = timeout % kOneSecondMicros;
  delta.tv_sec = timeout / kOneSecondMicros;
  struct timeval current_time;
  // Get the current time.
  if (gettimeofday(&current_time, NULL) == -1) {
    return false;
  }
  // Calculate time for end of timeout.
  struct timeval end_time;
  timeradd(&current_time, &delta, &end_time);
  struct timespec ts;
  TIMEVAL_TO_TIMESPEC(&end_time, &ts);
  // Wait for semaphore signalled or timeout.
  while (true) {
    int result = sem_timedwait(&sem_, &ts);
    if (result == 0) return true;  // Successfully got semaphore.
    if (result > 0) {
      // For glibc prior to 2.3.4 sem_timedwait returns the error instead of -1.
      errno = result;
      result = -1;
    }
    if (result == -1 && errno == ETIMEDOUT) return false;  // Timeout.
    CHECK(result == -1 && errno == EINTR);  // Signal caused spurious wakeup.
  }
 }
 Semaphore* OS::CreateSemaphore(int count) {
  return new CygwinSemaphore(count);
 }
 #ifdef ENABLE_LOGGING_AND_PROFILING
 static Sampler* active_sampler_ = NULL;
 static pthread_t vm_thread_ = 0;
 #if !defined(__GLIBC__) && (defined(__arm__) || defined(__thumb__))
 // Android runs a fairly new Linux kernel, so signal info is there,
 // but the C library doesn't have the structs defined.
 struct sigcontext {
  uint32_t trap_no;
  uint32_t error_code;
  uint32_t oldmask;
  uint32_t gregs[16];
  uint32_t arm_cpsr;
  uint32_t fault_address;
 };
 typedef uint32_t __sigset_t;
 typedef struct sigcontext mcontext_t;
 typedef struct ucontext {
  uint32_t uc_flags;
  struct ucontext* uc_link;
  stack_t uc_stack;
  mcontext_t uc_mcontext;
  __sigset_t uc_sigmask;
 } ucontext_t;
 enum ArmRegisters {R15 = 15, R13 = 13, R11 = 11};
 #endif
 // A function that determines if a signal handler is called in the context
 // of a VM thread.
 //
 // The problem is that SIGPROF signal can be delivered to an arbitrary thread
 // (see http://code.google.com/p/google-perftools/issues/detail?id=106#c2)
 // So, if the signal is being handled in the context of a non-VM thread,
 // it means that the VM thread is running, and trying to sample its stack can
 // cause a crash.
 static inline bool IsVmThread() {
  // In the case of a single VM thread, this check is enough.
  if (pthread_equal(pthread_self(), vm_thread_)) return true;
  // If there are multiple threads that use VM, they must have a thread id
  // stored in TLS. To verify that the thread is really executing VM,
  // we check Top's data. Having that ThreadManager::RestoreThread first
  // restores ThreadLocalTop from TLS, and only then erases the TLS value,
  // reading Top::thread_id() should not be affected by races.
  if (ThreadManager::HasId() && !ThreadManager::IsArchived() &&
      ThreadManager::CurrentId() == Top::thread_id()) {
    return true;
  }
  return false;
 }
 static void ProfilerSignalHandler(int signal, siginfo_t* info, void* context) {
 #ifndef V8_HOST_ARCH_MIPS
  USE(info);
  if (signal != SIGPROF) return;
  if (active_sampler_ == NULL) return;
  TickSample sample_obj;
  TickSample* sample = CpuProfiler::TickSampleEvent();
  if (sample == NULL) sample = &sample_obj;
  // We always sample the VM state.
  sample->state = VMState::current_state();
 #if 0
  // If profiling, we extract the current pc and sp.
  if (active_sampler_->IsProfiling()) {
    // Extracting the sample from the context is extremely machine dependent.
    ucontext_t* ucontext = reinterpret_cast<ucontext_t*>(context);
    mcontext_t& mcontext = ucontext->uc_mcontext;
 #if V8_HOST_ARCH_IA32
    sample->pc = reinterpret_cast<Address>(mcontext.gregs[REG_EIP]);
    sample->sp = reinterpret_cast<Address>(mcontext.gregs[REG_ESP]);
    sample->fp = reinterpret_cast<Address>(mcontext.gregs[REG_EBP]);
 #elif V8_HOST_ARCH_X64
    sample->pc = reinterpret_cast<Address>(mcontext.gregs[REG_RIP]);
    sample->sp = reinterpret_cast<Address>(mcontext.gregs[REG_RSP]);
    sample->fp = reinterpret_cast<Address>(mcontext.gregs[REG_RBP]);
 #elif V8_HOST_ARCH_ARM
 // An undefined macro evaluates to 0, so this applies to Android's Bionic also.
 #if (__GLIBC__ < 2 || (__GLIBC__ == 2 && __GLIBC_MINOR__ <= 3))
    sample->pc = reinterpret_cast<Address>(mcontext.gregs[R15]);
    sample->sp = reinterpret_cast<Address>(mcontext.gregs[R13]);
    sample->fp = reinterpret_cast<Address>(mcontext.gregs[R11]);
 #else
    sample->pc = reinterpret_cast<Address>(mcontext.arm_pc);
    sample->sp = reinterpret_cast<Address>(mcontext.arm_sp);
    sample->fp = reinterpret_cast<Address>(mcontext.arm_fp);
 #endif
 #elif V8_HOST_ARCH_MIPS
    // Implement this on MIPS.
    UNIMPLEMENTED();
 #endif
    if (IsVmThread()) {
      active_sampler_->SampleStack(sample);
    }
  }
 #endif
  active_sampler_->Tick(sample);
 #endif
 }
 class Sampler::PlatformData : public Malloced {
 public:
  PlatformData() {
    signal_handler_installed_ = false;
  }
  bool signal_handler_installed_;
  struct sigaction old_signal_handler_;
  struct itimerval old_timer_value_;
 };
 Sampler::Sampler(int interval, bool profiling)
    : interval_(interval), profiling_(profiling), active_(false) {
  data_ = new PlatformData();
 }
 Sampler::~Sampler() {
  delete data_;
 }
 void Sampler::Start() {
  // There can only be one active sampler at the time on POSIX
  // platforms.
  if (active_sampler_ != NULL) return;
  vm_thread_ = pthread_self();
  // Request profiling signals.
  struct sigaction sa;
  sa.sa_sigaction = ProfilerSignalHandler;
  sigemptyset(&sa.sa_mask);
  sa.sa_flags = SA_SIGINFO;
  if (sigaction(SIGPROF, &sa, &data_->old_signal_handler_) != 0) return;
  data_->signal_handler_installed_ = true;
  // Set the itimer to generate a tick for each interval.
  itimerval itimer;
  itimer.it_interval.tv_sec = interval_ / 1000;
  itimer.it_interval.tv_usec = (interval_ % 1000) * 1000;
  itimer.it_value.tv_sec = itimer.it_interval.tv_sec;
  itimer.it_value.tv_usec = itimer.it_interval.tv_usec;
  setitimer(ITIMER_PROF, &itimer, &data_->old_timer_value_);
  // Set this sampler as the active sampler.
  active_sampler_ = this;
  active_ = true;
 }
 void Sampler::Stop() {
  // Restore old signal handler
  if (data_->signal_handler_installed_) {
    setitimer(ITIMER_PROF, &data_->old_timer_value_, NULL);
    sigaction(SIGPROF, &data_->old_signal_handler_, 0);
    data_->signal_handler_installed_ = false;
  }
  // This sampler is no longer the active sampler.
  active_sampler_ = NULL;
  active_ = false;
 }
 #endif  // ENABLE_LOGGING_AND_PROFILING
 } }  // namespace v8::internal
--- a/deps/v8/src/platform.h
+++ b/deps/v8/src/platform.h
@ -362,6 +362,7 @@ class ThreadHandle {
 class Thread: public ThreadHandle {
 public:
 #ifndef __CYGWIN__
  // Opaque data type for thread-local storage keys.
  // LOCAL_STORAGE_KEY_MIN_VALUE and LOCAL_STORAGE_KEY_MAX_VALUE are specified
  // to ensure that enumeration type has correct value range (see Issue 830 for
@ -370,6 +371,10 @@ class Thread: public ThreadHandle {
    LOCAL_STORAGE_KEY_MIN_VALUE = kMinInt,
    LOCAL_STORAGE_KEY_MAX_VALUE = kMaxInt
  };
 #else
  typedef void *LocalStorageKey;
 #endif
  // Create new thread.
  Thread();
--- a/deps/v8/src/utils.h
+++ b/deps/v8/src/utils.h
@ -947,7 +947,7 @@ inline Dest BitCast(const Source& source) {
 }
 template <class Dest, class Source>
-inline Dest BitCast(Source* source) {
+inline Dest BitCast(Source*& source) {
  return BitCast<Dest>(reinterpret_cast<uintptr_t>(source));
 }
--- a/deps/v8/tools/utils.py
+++ b/deps/v8/tools/utils.py
@ -59,6 +59,8 @@ def GuessOS():
    return 'openbsd'
  elif id == 'SunOS':
    return 'solaris'
  elif id.find('CYGWIN') >= 0:
    return 'cygwin'
  else:
    return None