Revert "Move files in wtf/ to platform/wtf/"

third_party/WebKit/Source/platform/wtf/StackUtil.cpp

-// Copyright 2017 The Chromium Authors. All rights reserved.
-// Use of this source code is governed by a BSD-style license that can be
-// found in the LICENSE file.
-
-#include "platform/wtf/StackUtil.h"
-
-#include "platform/wtf/Assertions.h"
-#include "platform/wtf/Threading.h"
-#include "platform/wtf/WTFThreadData.h"
-
-#if OS(WIN)
-#include <stddef.h>
-#include <windows.h>
-#include <winnt.h>
-#elif defined(__GLIBC__)
-extern "C" void* __libc_stack_end;  // NOLINT
-#endif
-
-namespace WTF {
-
-size_t getUnderestimatedStackSize() {
-// FIXME: ASAN bot uses a fake stack as a thread stack frame,
-// and its size is different from the value which APIs tells us.
-#if defined(ADDRESS_SANITIZER)
-  return 0;
-#endif
-
-// FIXME: On Mac OSX and Linux, this method cannot estimate stack size
-// correctly for the main thread.
-
-#if defined(__GLIBC__) || OS(ANDROID) || OS(FREEBSD)
-  // pthread_getattr_np() can fail if the thread is not invoked by
-  // pthread_create() (e.g., the main thread of webkit_unit_tests).
-  // If so, a conservative size estimate is returned.
-
-  pthread_attr_t attr;
-  int error;
-#if OS(FREEBSD)
-  pthread_attr_init(&attr);
-  error = pthread_attr_get_np(pthread_self(), &attr);
-#else
-  error = pthread_getattr_np(pthread_self(), &attr);
-#endif
-  if (!error) {
-    void* base;
-    size_t size;
-    error = pthread_attr_getstack(&attr, &base, &size);
-    RELEASE_ASSERT(!error);
-    pthread_attr_destroy(&attr);
-    return size;
-  }
-#if OS(FREEBSD)
-  pthread_attr_destroy(&attr);
-#endif
-
-  // Return a 512k stack size, (conservatively) assuming the following:
-  //  - that size is much lower than the pthreads default (x86 pthreads has a 2M
-  //    default.)
-  //  - no one is running Blink with an RLIMIT_STACK override, let alone as
-  //    low as 512k.
-  //
-  return 512 * 1024;
-#elif OS(MACOSX)
-  // pthread_get_stacksize_np() returns too low a value for the main thread on
-  // OSX 10.9,
-  // http://mail.openjdk.java.net/pipermail/hotspot-dev/2013-October/011369.html
-  //
-  // Multiple workarounds possible, adopt the one made by
-  // https://github.com/robovm/robovm/issues/274
-  // (cf.
-  // https://developer.apple.com/library/mac/documentation/Cocoa/Conceptual/Multithreading/CreatingThreads/CreatingThreads.html
-  // on why hardcoding sizes is reasonable.)
-  if (pthread_main_np()) {
-#if defined(IOS)
-    pthread_attr_t attr;
-    pthread_attr_init(&attr);
-    size_t guardSize = 0;
-    pthread_attr_getguardsize(&attr, &guardSize);
-    // Stack size for the main thread is 1MB on iOS including the guard page
-    // size.
-    return (1 * 1024 * 1024 - guardSize);
-#else
-    // Stack size for the main thread is 8MB on OSX excluding the guard page
-    // size.
-    return (8 * 1024 * 1024);
-#endif
-  }
-  return pthread_get_stacksize_np(pthread_self());
-#elif OS(WIN) && COMPILER(MSVC)
-  return WTFThreadData::threadStackSize();
-#else
-#error "Stack frame size estimation not supported on this platform."
-  return 0;
-#endif
-}
-
-void* getStackStart() {
-#if defined(__GLIBC__) || OS(ANDROID) || OS(FREEBSD)
-  pthread_attr_t attr;
-  int error;
-#if OS(FREEBSD)
-  pthread_attr_init(&attr);
-  error = pthread_attr_get_np(pthread_self(), &attr);
-#else
-  error = pthread_getattr_np(pthread_self(), &attr);
-#endif
-  if (!error) {
-    void* base;
-    size_t size;
-    error = pthread_attr_getstack(&attr, &base, &size);
-    RELEASE_ASSERT(!error);
-    pthread_attr_destroy(&attr);
-    return reinterpret_cast<uint8_t*>(base) + size;
-  }
-#if OS(FREEBSD)
-  pthread_attr_destroy(&attr);
-#endif
-#if defined(__GLIBC__)
-  // pthread_getattr_np can fail for the main thread. In this case
-  // just like NaCl we rely on the __libc_stack_end to give us
-  // the start of the stack.
-  // See https://code.google.com/p/nativeclient/issues/detail?id=3431.
-  return __libc_stack_end;
-#else
-  NOTREACHED();
-  return nullptr;
-#endif
-#elif OS(MACOSX)
-  return pthread_get_stackaddr_np(pthread_self());
-#elif OS(WIN) && COMPILER(MSVC)
-// On Windows stack limits for the current thread are available in
-// the thread information block (TIB). Its fields can be accessed through
-// FS segment register on x86 and GS segment register on x86_64.
-#ifdef _WIN64
-  return reinterpret_cast<void*>(__readgsqword(offsetof(NT_TIB64, StackBase)));
-#else
-  return reinterpret_cast<void*>(__readfsdword(offsetof(NT_TIB, StackBase)));
-#endif
-#else
-#error Unsupported getStackStart on this platform.
-#endif
-}
-
-namespace internal {
-
-uintptr_t s_mainThreadStackStart = 0;
-uintptr_t s_mainThreadUnderestimatedStackSize = 0;
-
-void initializeMainThreadStackEstimate() {
-  // getStackStart is exclusive, not inclusive (i.e. it points past the last
-  // page of the stack in linear order). So, to ensure an inclusive comparison,
-  // subtract here and below.
-  s_mainThreadStackStart =
-      reinterpret_cast<uintptr_t>(getStackStart()) - sizeof(void*);
-
-  size_t underestimatedStackSize = getUnderestimatedStackSize();
-  if (underestimatedStackSize > sizeof(void*)) {
-    underestimatedStackSize = underestimatedStackSize - sizeof(void*);
-  }
-  s_mainThreadUnderestimatedStackSize = underestimatedStackSize;
-}
-
-#if OS(WIN) && COMPILER(MSVC)
-size_t threadStackSize() {
-  // Notice that we cannot use the TIB's StackLimit for the stack end, as i
-  // tracks the end of the committed range. We're after the end of the reserved
-  // stack area (most of which will be uncommitted, most times.)
-  MEMORY_BASIC_INFORMATION stackInfo;
-  memset(&stackInfo, 0, sizeof(MEMORY_BASIC_INFORMATION));
-  size_t resultSize =
-      VirtualQuery(&stackInfo, &stackInfo, sizeof(MEMORY_BASIC_INFORMATION));
-  DCHECK_GE(resultSize, sizeof(MEMORY_BASIC_INFORMATION));
-  uint8_t* stackEnd = reinterpret_cast<uint8_t*>(stackInfo.AllocationBase);
-
-  uint8_t* stackStart = reinterpret_cast<uint8_t*>(WTF::getStackStart());
-  RELEASE_ASSERT(stackStart && stackStart > stackEnd);
-  size_t s_threadStackSize = static_cast<size_t>(stackStart - stackEnd);
-  // When the third last page of the reserved stack is accessed as a
-  // guard page, the second last page will be committed (along with removing
-  // the guard bit on the third last) _and_ a stack overflow exception
-  // is raised.
-  //
-  // We have zero interest in running into stack overflow exceptions while
-  // marking objects, so simply consider the last three pages + one above
-  // as off-limits and adjust the reported stack size accordingly.
-  //
-  // http://blogs.msdn.com/b/satyem/archive/2012/08/13/thread-s-stack-memory-management.aspx
-  // explains the details.
-  RELEASE_ASSERT(s_threadStackSize > 4 * 0x1000);
-  s_threadStackSize -= 4 * 0x1000;
-  return s_threadStackSize;
-}
-#endif
-
-}  // namespace internal
-
-}  // namespace WTF