Move platform abstraction to base library

src/platform-cygwin.cc

Index: src/platform-cygwin.cc
diff --git a/src/platform-cygwin.cc b/src/platform-cygwin.cc
deleted file mode 100644
index ac313b2a0348e16a78d672c5ba8b15cf686bba68..0000000000000000000000000000000000000000
--- a/src/platform-cygwin.cc
+++ /dev/null
@@ -1,331 +0,0 @@
-// Copyright 2012 the V8 project authors. All rights reserved.
-// Use of this source code is governed by a BSD-style license that can be
-// found in the LICENSE file.
-
-// Platform-specific code for Cygwin goes here. For the POSIX-compatible
-// parts, the implementation is in platform-posix.cc.
-
-#include <errno.h>
-#include <pthread.h>
-#include <semaphore.h>
-#include <stdarg.h>
-#include <strings.h>    // index
-#include <sys/mman.h>   // mmap & munmap
-#include <sys/time.h>
-#include <unistd.h>     // sysconf
-
-#include <cmath>
-
-#undef MAP_TYPE
-
-#include "src/base/win32-headers.h"
-#include "src/platform.h"
-#include "src/utils.h"
-
-namespace v8 {
-namespace internal {
-
-
-const char* OS::LocalTimezone(double time, TimezoneCache* cache) {
-  if (std::isnan(time)) return "";
-  time_t tv = static_cast<time_t>(std::floor(time/msPerSecond));
-  struct tm* t = localtime(&tv);
-  if (NULL == t) return "";
-  return tzname[0];  // The location of the timezone string on Cygwin.
-}
-
-
-double OS::LocalTimeOffset(TimezoneCache* cache) {
-  // 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);
-  // time - localtime includes any daylight savings offset, so subtract it.
-  return static_cast<double>((mktime(loc) - utc) * msPerSecond -
-                             (loc->tm_isdst > 0 ? 3600 * msPerSecond : 0));
-}
-
-
-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) return NULL;
-  *allocated = msize;
-  return mbase;
-}
-
-
-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_; }
-  virtual int size() { return size_; }
- private:
-  FILE* file_;
-  void* memory_;
-  int size_;
-};
-
-
-OS::MemoryMappedFile* OS::MemoryMappedFile::open(const char* name) {
-  FILE* file = fopen(name, "r+");
-  if (file == NULL) return NULL;
-
-  fseek(file, 0, SEEK_END);
-  int size = ftell(file);
-
-  void* memory =
-      mmap(0, size, PROT_READ | PROT_WRITE, MAP_SHARED, fileno(file), 0);
-  return new PosixMemoryMappedFile(file, memory, 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_);
-}
-
-
-std::vector<OS::SharedLibraryAddress> OS::GetSharedLibraryAddresses() {
-  std::vector<SharedLibraryAddresses> result;
-  // 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 result;
-
-  // 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);
-      }
-      result.push_back(SharedLibraryAddress(lib_name, start, end));
-    } else {
-      // Entry not describing executable data. Skip to end of line to set up
-      // reading the next entry.
-      do {
-        c = getc(fp);
-      } while ((c != EOF) && (c != '\n'));
-      if (c == EOF) break;
-    }
-  }
-  free(lib_name);
-  fclose(fp);
-  return result;
-}
-
-
-void OS::SignalCodeMovingGC() {
-  // Nothing to do on Cygwin.
-}
-
-
-// The VirtualMemory implementation is taken from platform-win32.cc.
-// The mmap-based virtual memory implementation as it is used on most posix
-// platforms does not work well because Cygwin does not support MAP_FIXED.
-// This causes VirtualMemory::Commit to not always commit the memory region
-// specified.
-
-static void* GetRandomAddr() {
-  Isolate* isolate = Isolate::UncheckedCurrent();
-  // Note that the current isolate isn't set up in a call path via
-  // CpuFeatures::Probe. We don't care about randomization in this case because
-  // the code page is immediately freed.
-  if (isolate != NULL) {
-    // The address range used to randomize RWX allocations in OS::Allocate
-    // Try not to map pages into the default range that windows loads DLLs
-    // Use a multiple of 64k to prevent committing unused memory.
-    // Note: This does not guarantee RWX regions will be within the
-    // range kAllocationRandomAddressMin to kAllocationRandomAddressMax
-#ifdef V8_HOST_ARCH_64_BIT
-    static const intptr_t kAllocationRandomAddressMin = 0x0000000080000000;
-    static const intptr_t kAllocationRandomAddressMax = 0x000003FFFFFF0000;
-#else
-    static const intptr_t kAllocationRandomAddressMin = 0x04000000;
-    static const intptr_t kAllocationRandomAddressMax = 0x3FFF0000;
-#endif
-    uintptr_t address =
-        (isolate->random_number_generator()->NextInt() << kPageSizeBits) |
-        kAllocationRandomAddressMin;
-    address &= kAllocationRandomAddressMax;
-    return reinterpret_cast<void *>(address);
-  }
-  return NULL;
-}
-
-
-static void* RandomizedVirtualAlloc(size_t size, int action, int protection) {
-  LPVOID base = NULL;
-
-  if (protection == PAGE_EXECUTE_READWRITE || protection == PAGE_NOACCESS) {
-    // For exectutable pages try and randomize the allocation address
-    for (size_t attempts = 0; base == NULL && attempts < 3; ++attempts) {
-      base = VirtualAlloc(GetRandomAddr(), size, action, protection);
-    }
-  }
-
-  // After three attempts give up and let the OS find an address to use.
-  if (base == NULL) base = VirtualAlloc(NULL, size, action, protection);
-
-  return base;
-}
-
-
-VirtualMemory::VirtualMemory() : address_(NULL), size_(0) { }
-
-
-VirtualMemory::VirtualMemory(size_t size)
-    : address_(ReserveRegion(size)), size_(size) { }
-
-
-VirtualMemory::VirtualMemory(size_t size, size_t alignment)
-    : address_(NULL), size_(0) {
-  ASSERT(IsAligned(alignment, static_cast<intptr_t>(OS::AllocateAlignment())));
-  size_t request_size = RoundUp(size + alignment,
-                                static_cast<intptr_t>(OS::AllocateAlignment()));
-  void* address = ReserveRegion(request_size);
-  if (address == NULL) return;
-  uint8_t* base = RoundUp(static_cast<uint8_t*>(address), alignment);
-  // Try reducing the size by freeing and then reallocating a specific area.
-  bool result = ReleaseRegion(address, request_size);
-  USE(result);
-  ASSERT(result);
-  address = VirtualAlloc(base, size, MEM_RESERVE, PAGE_NOACCESS);
-  if (address != NULL) {
-    request_size = size;
-    ASSERT(base == static_cast<uint8_t*>(address));
-  } else {
-    // Resizing failed, just go with a bigger area.
-    address = ReserveRegion(request_size);
-    if (address == NULL) return;
-  }
-  address_ = address;
-  size_ = request_size;
-}
-
-
-VirtualMemory::~VirtualMemory() {
-  if (IsReserved()) {
-    bool result = ReleaseRegion(address_, size_);
-    ASSERT(result);
-    USE(result);
-  }
-}
-
-
-bool VirtualMemory::IsReserved() {
-  return address_ != NULL;
-}
-
-
-void VirtualMemory::Reset() {
-  address_ = NULL;
-  size_ = 0;
-}
-
-
-bool VirtualMemory::Commit(void* address, size_t size, bool is_executable) {
-  return CommitRegion(address, size, is_executable);
-}
-
-
-bool VirtualMemory::Uncommit(void* address, size_t size) {
-  ASSERT(IsReserved());
-  return UncommitRegion(address, size);
-}
-
-
-void* VirtualMemory::ReserveRegion(size_t size) {
-  return RandomizedVirtualAlloc(size, MEM_RESERVE, PAGE_NOACCESS);
-}
-
-
-bool VirtualMemory::CommitRegion(void* base, size_t size, bool is_executable) {
-  int prot = is_executable ? PAGE_EXECUTE_READWRITE : PAGE_READWRITE;
-  if (NULL == VirtualAlloc(base, size, MEM_COMMIT, prot)) {
-    return false;
-  }
-  return true;
-}
-
-
-bool VirtualMemory::Guard(void* address) {
-  if (NULL == VirtualAlloc(address,
-                           OS::CommitPageSize(),
-                           MEM_COMMIT,
-                           PAGE_NOACCESS)) {
-    return false;
-  }
-  return true;
-}
-
-
-bool VirtualMemory::UncommitRegion(void* base, size_t size) {
-  return VirtualFree(base, size, MEM_DECOMMIT) != 0;
-}
-
-
-bool VirtualMemory::ReleaseRegion(void* base, size_t size) {
-  return VirtualFree(base, 0, MEM_RELEASE) != 0;
-}
-
-
-bool VirtualMemory::HasLazyCommits() {
-  // TODO(alph): implement for the platform.
-  return false;
-}
-
-} }  // namespace v8::internal