Remove SPS profiler.

- Conditionals and code blocks. (MOZ_ENABLE_PROFILER_SPS)
- Stub out several profiler-only functions.

4 files changed, 3 insertions, 661 deletions

diff --git a/xpcom/build/XPCOMInit.cpp b/xpcom/build/XPCOMInit.cpp
index 7b220558fb..e8ee5828a4 100644
--- a/xpcom/build/XPCOMInit.cpp
+++ b/xpcom/build/XPCOMInit.cpp
@@ -1037,20 +1037,6 @@ ShutdownXPCOM(nsIServiceManager* aServMgr)
     NS_WARNING("Component Manager was never created ...");
   }
 
-#ifdef MOZ_ENABLE_PROFILER_SPS
-  // In optimized builds we don't do shutdown collections by default, so
-  // uncollected (garbage) objects may keep the nsXPConnect singleton alive,
-  // and its XPCJSContext along with it. However, we still destroy various
-  // bits of state in JS_ShutDown(), so we need to make sure the profiler
-  // can't access them when it shuts down. This call nulls out the
-  // JS pseudo-stack's internal reference to the main thread JSContext,
-  // duplicating the call in XPCJSContext::~XPCJSContext() in case that
-  // never fired.
-  if (PseudoStack* stack = mozilla_get_pseudo_stack()) {
-    stack->sampleContext(nullptr);
-  }
-#endif
-
   if (sInitializedJS) {
     // Shut down the JS engine.
     JS_ShutDown();
diff --git a/xpcom/threads/HangMonitor.cpp b/xpcom/threads/HangMonitor.cpp
index bd415be50e..6def6ed617 100644
--- a/xpcom/threads/HangMonitor.cpp
+++ b/xpcom/threads/HangMonitor.cpp
@@ -26,10 +26,6 @@
 #include <windows.h>
 #endif
 
-#if defined(MOZ_ENABLE_PROFILER_SPS) && defined(MOZ_PROFILING) && defined(XP_WIN)
-  #define REPORT_CHROME_HANGS
-#endif
-
 namespace mozilla {
 namespace HangMonitor {
 
@@ -41,10 +37,6 @@ volatile bool gDebugDisableHangMonitor = false;
 
 const char kHangMonitorPrefName[] = "hangmonitor.timeout";
 
-#ifdef REPORT_CHROME_HANGS
-const char kTelemetryPrefName[] = "toolkit.telemetry.enabled";
-#endif
-
 // Monitor protects gShutdown and gTimeout, but not gTimestamp which rely on
 // being atomically set by the processor; synchronization doesn't really matter
 // in this use case.
@@ -62,31 +54,11 @@ bool gShutdown;
 // we're currently not processing events.
 Atomic<PRIntervalTime> gTimestamp(PR_INTERVAL_NO_WAIT);
 
-#ifdef REPORT_CHROME_HANGS
-// Main thread ID used in reporting chrome hangs under Windows
-static HANDLE winMainThreadHandle = nullptr;
-
-// Default timeout for reporting chrome hangs to Telemetry (5 seconds)
-static const int32_t DEFAULT_CHROME_HANG_INTERVAL = 5;
-
-// Maximum number of PCs to gather from the stack
-static const int32_t MAX_CALL_STACK_PCS = 400;
-#endif
-
 // PrefChangedFunc
 void
 PrefChanged(const char*, void*)
 {
   int32_t newval = Preferences::GetInt(kHangMonitorPrefName);
-#ifdef REPORT_CHROME_HANGS
-  // Monitor chrome hangs on the profiling branch if Telemetry enabled
-  if (newval == 0) {
-    bool telemetryEnabled = Preferences::GetBool(kTelemetryPrefName);
-    if (telemetryEnabled) {
-      newval = DEFAULT_CHROME_HANG_INTERVAL;
-    }
-  }
-#endif
   MonitorAutoLock lock(*gMonitor);
   if (newval != gTimeout) {
     gTimeout = newval;
@@ -110,89 +82,6 @@ Crash()
   NS_RUNTIMEABORT("HangMonitor triggered");
 }
 
-#ifdef REPORT_CHROME_HANGS
-
-static void
-ChromeStackWalker(uint32_t aFrameNumber, void* aPC, void* aSP, void* aClosure)
-{
-  MOZ_ASSERT(aClosure);
-  std::vector<uintptr_t>* stack =
-    static_cast<std::vector<uintptr_t>*>(aClosure);
-  if (stack->size() == MAX_CALL_STACK_PCS) {
-    return;
-  }
-  MOZ_ASSERT(stack->size() < MAX_CALL_STACK_PCS);
-  stack->push_back(reinterpret_cast<uintptr_t>(aPC));
-}
-
-static void
-GetChromeHangReport(Telemetry::ProcessedStack& aStack,
-                    int32_t& aSystemUptime,
-                    int32_t& aFirefoxUptime)
-{
-  MOZ_ASSERT(winMainThreadHandle);
-
-  // The thread we're about to suspend might have the alloc lock
-  // so allocate ahead of time
-  std::vector<uintptr_t> rawStack;
-  rawStack.reserve(MAX_CALL_STACK_PCS);
-
-  // Workaround possible deadlock where the main thread is running a
-  // long-standing JS job, and happens to be in the JIT allocator when we
-  // suspend it. Since, on win 64, this requires holding a process lock that
-  // MozStackWalk requires, take this "workaround lock" to avoid deadlock.
-#ifdef _WIN64
-  AcquireStackWalkWorkaroundLock();
-#endif
-  DWORD ret = ::SuspendThread(winMainThreadHandle);
-  bool suspended = false;
-  if (ret != -1) {
-    // SuspendThread is asynchronous, so the thread may still be running. Use
-    // GetThreadContext to ensure it's really suspended.
-    // See https://blogs.msdn.microsoft.com/oldnewthing/20150205-00/?p=44743.
-    CONTEXT context;
-    context.ContextFlags = CONTEXT_CONTROL;
-    if (::GetThreadContext(winMainThreadHandle, &context)) {
-      suspended = true;
-    }
-  }
-
-#ifdef _WIN64
-  ReleaseStackWalkWorkaroundLock();
-#endif
-
-  if (!suspended) {
-    if (ret != -1) {
-      MOZ_ALWAYS_TRUE(::ResumeThread(winMainThreadHandle) != DWORD(-1));
-    }
-    return;
-  }
-
-  MozStackWalk(ChromeStackWalker, /* skipFrames */ 0, /* maxFrames */ 0,
-               reinterpret_cast<void*>(&rawStack),
-               reinterpret_cast<uintptr_t>(winMainThreadHandle), nullptr);
-  ret = ::ResumeThread(winMainThreadHandle);
-  if (ret == -1) {
-    return;
-  }
-  aStack = Telemetry::GetStackAndModules(rawStack);
-
-  // Record system uptime (in minutes) at the time of the hang
-  aSystemUptime = ((GetTickCount() / 1000) - (gTimeout * 2)) / 60;
-
-  // Record Firefox uptime (in minutes) at the time of the hang
-  bool error;
-  TimeStamp processCreation = TimeStamp::ProcessCreation(error);
-  if (!error) {
-    TimeDuration td = TimeStamp::Now() - processCreation;
-    aFirefoxUptime = (static_cast<int32_t>(td.ToSeconds()) - (gTimeout * 2)) / 60;
-  } else {
-    aFirefoxUptime = -1;
-  }
-}
-
-#endif
-
 void
 ThreadMain(void*)
 {
@@ -206,13 +95,6 @@ ThreadMain(void*)
   PRIntervalTime lastTimestamp = 0;
   int waitCount = 0;
 
-#ifdef REPORT_CHROME_HANGS
-  Telemetry::ProcessedStack stack;
-  int32_t systemUptime = -1;
-  int32_t firefoxUptime = -1;
-  UniquePtr<HangAnnotations> annotations;
-#endif
-
   while (true) {
     if (gShutdown) {
       return; // Exit the thread
@@ -233,14 +115,6 @@ ThreadMain(void*)
         timestamp == lastTimestamp &&
         gTimeout > 0) {
       ++waitCount;
-#ifdef REPORT_CHROME_HANGS
-      // Capture the chrome-hang stack + Firefox & system uptimes after
-      // the minimum hang duration has been reached (not when the hang ends)
-      if (waitCount == 2) {
-        GetChromeHangReport(stack, systemUptime, firefoxUptime);
-        annotations = ChromeHangAnnotatorCallout();
-      }
-#else
       // This is the crash-on-hang feature.
       // See bug 867313 for the quirk in the waitCount comparison
       if (waitCount >= 2) {
@@ -251,16 +125,7 @@ ThreadMain(void*)
           Crash();
         }
       }
-#endif
     } else {
-#ifdef REPORT_CHROME_HANGS
-      if (waitCount >= 2) {
-        uint32_t hangDuration = PR_IntervalToSeconds(now - lastTimestamp);
-        Telemetry::RecordChromeHang(hangDuration, stack, systemUptime,
-                                    firefoxUptime, Move(annotations));
-        stack.Clear();
-      }
-#endif
       lastTimestamp = timestamp;
       waitCount = 0;
     }
@@ -289,15 +154,6 @@ Startup()
   Preferences::RegisterCallback(PrefChanged, kHangMonitorPrefName, nullptr);
   PrefChanged(nullptr, nullptr);
 
-#ifdef REPORT_CHROME_HANGS
-  Preferences::RegisterCallback(PrefChanged, kTelemetryPrefName, nullptr);
-  winMainThreadHandle =
-    OpenThread(THREAD_ALL_ACCESS, FALSE, GetCurrentThreadId());
-  if (!winMainThreadHandle) {
-    return;
-  }
-#endif
-
   // Don't actually start measuring hangs until we hit the main event loop.
   // This potentially misses a small class of really early startup hangs,
   // but avoids dealing with some xpcshell tests and other situations which
diff --git a/xpcom/threads/ThreadStackHelper.cpp b/xpcom/threads/ThreadStackHelper.cpp
index 1713c9194d..2c0e879866 100644
--- a/xpcom/threads/ThreadStackHelper.cpp
+++ b/xpcom/threads/ThreadStackHelper.cpp
@@ -9,9 +9,6 @@
 #include "nsJSPrincipals.h"
 #include "nsScriptSecurityManager.h"
 #include "jsfriendapi.h"
-#ifdef MOZ_THREADSTACKHELPER_NATIVE
-#include "shared-libraries.h"
-#endif
 
 #include "mozilla/Assertions.h"
 #include "mozilla/Attributes.h"
@@ -62,17 +59,6 @@
 #endif
 #endif
 
-#ifdef MOZ_THREADSTACKHELPER_NATIVE
-#if defined(MOZ_THREADSTACKHELPER_X86) || \
-    defined(MOZ_THREADSTACKHELPER_X64) || \
-    defined(MOZ_THREADSTACKHELPER_ARM)
-// On these architectures, the stack grows downwards (toward lower addresses).
-#define MOZ_THREADSTACKHELPER_STACK_GROWS_DOWN
-#else
-#error "Unsupported architecture"
-#endif
-#endif // MOZ_THREADSTACKHELPER_NATIVE
-
 namespace mozilla {
 
 void
@@ -114,14 +100,6 @@ ThreadStackHelper::Shutdown()
 
 ThreadStackHelper::ThreadStackHelper()
   : mStackToFill(nullptr)
-#ifdef MOZ_THREADSTACKHELPER_PSEUDO
-  , mPseudoStack(mozilla_get_pseudo_stack())
-#ifdef MOZ_THREADSTACKHELPER_NATIVE
-  , mContextToFill(nullptr)
-#endif
-  , mMaxStackSize(Stack::sMaxInlineStorage)
-  , mMaxBufferSize(512)
-#endif
 {
 #if defined(XP_LINUX)
   MOZ_ALWAYS_TRUE(!::sem_init(&mSem, 0, 0));
@@ -131,18 +109,11 @@ ThreadStackHelper::ThreadStackHelper()
     ::GetCurrentProcess(), ::GetCurrentThread(),
     ::GetCurrentProcess(), &mThreadID,
     THREAD_SUSPEND_RESUME
-#ifdef MOZ_THREADSTACKHELPER_NATIVE
-    | THREAD_GET_CONTEXT | THREAD_QUERY_INFORMATION
-#endif
     , FALSE, 0);
   MOZ_ASSERT(mInitialized);
 #elif defined(XP_MACOSX)
   mThreadID = mach_thread_self();
 #endif
-
-#ifdef MOZ_THREADSTACKHELPER_NATIVE
-  GetThreadStackBase();
-#endif
 }
 
 ThreadStackHelper::~ThreadStackHelper()
@@ -156,45 +127,6 @@ ThreadStackHelper::~ThreadStackHelper()
 #endif
 }
 
-#ifdef MOZ_THREADSTACKHELPER_NATIVE
-void ThreadStackHelper::GetThreadStackBase()
-{
-  mThreadStackBase = 0;
-
-#if defined(XP_LINUX)
-  void* stackAddr;
-  size_t stackSize;
-  ::pthread_t pthr = ::pthread_self();
-  ::pthread_attr_t pthr_attr;
-  NS_ENSURE_TRUE_VOID(!::pthread_getattr_np(pthr, &pthr_attr));
-  if (!::pthread_attr_getstack(&pthr_attr, &stackAddr, &stackSize)) {
-#ifdef MOZ_THREADSTACKHELPER_STACK_GROWS_DOWN
-    mThreadStackBase = intptr_t(stackAddr) + stackSize;
-#else
-    mThreadStackBase = intptr_t(stackAddr);
-#endif
-  }
-  MOZ_ALWAYS_TRUE(!::pthread_attr_destroy(&pthr_attr));
-
-#elif defined(XP_WIN)
-  ::MEMORY_BASIC_INFORMATION meminfo = {};
-  NS_ENSURE_TRUE_VOID(::VirtualQuery(&meminfo, &meminfo, sizeof(meminfo)));
-#ifdef MOZ_THREADSTACKHELPER_STACK_GROWS_DOWN
-  mThreadStackBase = intptr_t(meminfo.BaseAddress) + meminfo.RegionSize;
-#else
-  mThreadStackBase = intptr_t(meminfo.AllocationBase);
-#endif
-
-#elif defined(XP_MACOSX)
-  ::pthread_t pthr = ::pthread_self();
-  mThreadStackBase = intptr_t(::pthread_get_stackaddr_np(pthr));
-
-#else
-  #error "Unsupported platform"
-#endif // platform
-}
-#endif // MOZ_THREADSTACKHELPER_NATIVE
-
 namespace {
 template<typename T>
 class ScopedSetPtr
@@ -281,53 +213,10 @@ ThreadStackHelper::GetStack(Stack& aStack)
 #endif
 }
 
-#ifdef MOZ_THREADSTACKHELPER_NATIVE
-class ThreadStackHelper::ThreadContext final
-{
-public:
-  // TODO: provide per-platform definition of Context.
-  typedef struct {} Context;
-
-  // Limit copied stack to 4kB
-  static const size_t kMaxStackSize = 0x1000;
-  // Limit unwound stack to 32 frames
-  static const unsigned int kMaxStackFrames = 32;
-  // Whether this structure contains valid data
-  bool mValid;
-  // Processor context
-  Context mContext;
-  // Stack area
-  UniquePtr<uint8_t[]> mStack;
-  // Start of stack area
-  uintptr_t mStackBase;
-  // Size of stack area
-  size_t mStackSize;
-  // End of stack area
-  const void* mStackEnd;
-
-  ThreadContext()
-    : mValid(false)
-    , mStackBase(0)
-    , mStackSize(0)
-    , mStackEnd(nullptr) {}
-};
-#endif // MOZ_THREADSTACKHELPER_NATIVE
-
 void
 ThreadStackHelper::GetNativeStack(Stack& aStack)
 {
-#ifdef MOZ_THREADSTACKHELPER_NATIVE
-  ThreadContext context;
-  context.mStack = MakeUnique<uint8_t[]>(ThreadContext::kMaxStackSize);
-
-  ScopedSetPtr<ThreadContext> contextPtr(mContextToFill, &context);
-
-  // Get pseudostack first and fill the thread context.
-  GetStack(aStack);
-  NS_ENSURE_TRUE_VOID(context.mValid);
-
-  // TODO: walk the saved stack frames.
-#endif // MOZ_THREADSTACKHELPER_NATIVE
+  /*** STUB ***/
 }
 
 #ifdef XP_LINUX
@@ -353,369 +242,20 @@ ThreadStackHelper::PrepareStackBuffer(Stack& aStack)
 {
   // Return false to skip getting the stack and return an empty stack
   aStack.clear();
-#ifdef MOZ_THREADSTACKHELPER_PSEUDO
-  /* Normally, provided the profiler is enabled, it would be an error if we
-     don't have a pseudostack here (the thread probably forgot to call
-     profiler_register_thread). However, on B2G, profiling secondary threads
-     may be disabled despite profiler being enabled. This is by-design and
-     is not an error. */
-  MOZ_ASSERT(mPseudoStack);
-  if (!aStack.reserve(mMaxStackSize) ||
-      !aStack.reserve(aStack.capacity()) || // reserve up to the capacity
-      !aStack.EnsureBufferCapacity(mMaxBufferSize)) {
-    return false;
-  }
-  return true;
-#else
   return false;
-#endif
-}
-
-#ifdef MOZ_THREADSTACKHELPER_PSEUDO
-
-namespace {
-
-bool
-IsChromeJSScript(JSScript* aScript)
-{
-  // May be called from another thread or inside a signal handler.
-  // We assume querying the script is safe but we must not manipulate it.
-
-  nsIScriptSecurityManager* const secman =
-    nsScriptSecurityManager::GetScriptSecurityManager();
-  NS_ENSURE_TRUE(secman, false);
-
-  JSPrincipals* const principals = JS_GetScriptPrincipals(aScript);
-  return secman->IsSystemPrincipal(nsJSPrincipals::get(principals));
-}
-
-// Get the full path after the URI scheme, if the URI matches the scheme.
-// For example, GetFullPathForScheme("a://b/c/d/e", "a://") returns "b/c/d/e".
-template <size_t LEN>
-const char*
-GetFullPathForScheme(const char* filename, const char (&scheme)[LEN]) {
-  // Account for the null terminator included in LEN.
-  if (!strncmp(filename, scheme, LEN - 1)) {
-    return filename + LEN - 1;
-  }
-  return nullptr;
-}
-
-// Get the full path after a URI component, if the URI contains the component.
-// For example, GetPathAfterComponent("a://b/c/d/e", "/c/") returns "d/e".
-template <size_t LEN>
-const char*
-GetPathAfterComponent(const char* filename, const char (&component)[LEN]) {
-  const char* found = nullptr;
-  const char* next = strstr(filename, component);
-  while (next) {
-    // Move 'found' to end of the component, after the separator '/'.
-    // 'LEN - 1' accounts for the null terminator included in LEN,
-    found = next + LEN - 1;
-    // Resume searching before the separator '/'.
-    next = strstr(found - 1, component);
-  }
-  return found;
 }
 
-} // namespace
-
-const char*
-ThreadStackHelper::AppendJSEntry(const volatile StackEntry* aEntry,
-                                 intptr_t& aAvailableBufferSize,
-                                 const char* aPrevLabel)
-{
-  // May be called from another thread or inside a signal handler.
-  // We assume querying the script is safe but we must not manupulate it.
-  // Also we must not allocate any memory from heap.
-  MOZ_ASSERT(aEntry->isJs());
-
-  const char* label;
-  JSScript* script = aEntry->script();
-  if (!script) {
-    label = "(profiling suppressed)";
-  } else if (IsChromeJSScript(aEntry->script())) {
-    const char* filename = JS_GetScriptFilename(aEntry->script());
-    const unsigned lineno = JS_PCToLineNumber(aEntry->script(), aEntry->pc());
-    MOZ_ASSERT(filename);
-
-    char buffer[128]; // Enough to fit longest js file name from the tree
-
-    // Some script names are in the form "foo -> bar -> baz".
-    // Here we find the origin of these redirected scripts.
-    const char* basename = GetPathAfterComponent(filename, " -> ");
-    if (basename) {
-      filename = basename;
-    }
-
-    basename = GetFullPathForScheme(filename, "chrome://");
-    if (!basename) {
-      basename = GetFullPathForScheme(filename, "resource://");
-    }
-    if (!basename) {
-      // If the (add-on) script is located under the {profile}/extensions
-      // directory, extract the path after the /extensions/ part.
-      basename = GetPathAfterComponent(filename, "/extensions/");
-    }
-    if (!basename) {
-      // Only keep the file base name for paths outside the above formats.
-      basename = strrchr(filename, '/');
-      basename = basename ? basename + 1 : filename;
-      // Look for Windows path separator as well.
-      filename = strrchr(basename, '\\');
-      if (filename) {
-        basename = filename + 1;
-      }
-    }
-
-    size_t len = SprintfLiteral(buffer, "%s:%u", basename, lineno);
-    if (len < sizeof(buffer)) {
-      if (mStackToFill->IsSameAsEntry(aPrevLabel, buffer)) {
-        return aPrevLabel;
-      }
-
-      // Keep track of the required buffer size
-      aAvailableBufferSize -= (len + 1);
-      if (aAvailableBufferSize >= 0) {
-        // Buffer is big enough.
-        return mStackToFill->InfallibleAppendViaBuffer(buffer, len);
-      }
-      // Buffer is not big enough; fall through to using static label below.
-    }
-    // snprintf failed or buffer is not big enough.
-    label = "(chrome script)";
-  } else {
-    label = "(content script)";
-  }
-
-  if (mStackToFill->IsSameAsEntry(aPrevLabel, label)) {
-    return aPrevLabel;
-  }
-  mStackToFill->infallibleAppend(label);
-  return label;
-}
-
-#endif // MOZ_THREADSTACKHELPER_PSEUDO
-
 void
 ThreadStackHelper::FillStackBuffer()
 {
   MOZ_ASSERT(mStackToFill->empty());
-
-#ifdef MOZ_THREADSTACKHELPER_PSEUDO
-  size_t reservedSize = mStackToFill->capacity();
-  size_t reservedBufferSize = mStackToFill->AvailableBufferSize();
-  intptr_t availableBufferSize = intptr_t(reservedBufferSize);
-
-  // Go from front to back
-  const volatile StackEntry* entry = mPseudoStack->mStack;
-  const volatile StackEntry* end = entry + mPseudoStack->stackSize();
-  // Deduplicate identical, consecutive frames
-  const char* prevLabel = nullptr;
-  for (; reservedSize-- && entry != end; entry++) {
-    /* We only accept non-copy labels, including js::RunScript,
-       because we only want static labels in the hang stack. */
-    if (entry->isCopyLabel()) {
-      continue;
-    }
-    if (entry->isJs()) {
-      prevLabel = AppendJSEntry(entry, availableBufferSize, prevLabel);
-      continue;
-    }
-#ifdef MOZ_THREADSTACKHELPER_NATIVE
-    if (mContextToFill) {
-      mContextToFill->mStackEnd = entry->stackAddress();
-    }
-#endif
-    const char* const label = entry->label();
-    if (mStackToFill->IsSameAsEntry(prevLabel, label)) {
-      // Avoid duplicate labels to save space in the stack.
-      continue;
-    }
-    mStackToFill->infallibleAppend(label);
-    prevLabel = label;
-  }
-
-  // end != entry if we exited early due to not enough reserved frames.
-  // Expand the number of reserved frames for next time.
-  mMaxStackSize = mStackToFill->capacity() + (end - entry);
-
-  // availableBufferSize < 0 if we needed a larger buffer than we reserved.
-  // Calculate a new reserve size for next time.
-  if (availableBufferSize < 0) {
-    mMaxBufferSize = reservedBufferSize - availableBufferSize;
-  }
-#endif
+  /*** STUB ***/
 }
 
 MOZ_ASAN_BLACKLIST void
 ThreadStackHelper::FillThreadContext(void* aContext)
 {
-#ifdef MOZ_THREADSTACKHELPER_NATIVE
-  if (!mContextToFill) {
-    return;
-  }
-
-#if 0 // TODO: remove dependency on Breakpad structs.
-#if defined(XP_LINUX)
-  const ucontext_t& context = *reinterpret_cast<ucontext_t*>(aContext);
-#if defined(MOZ_THREADSTACKHELPER_X86)
-  mContextToFill->mContext.context_flags = MD_CONTEXT_X86_FULL;
-  mContextToFill->mContext.edi = context.uc_mcontext.gregs[REG_EDI];
-  mContextToFill->mContext.esi = context.uc_mcontext.gregs[REG_ESI];
-  mContextToFill->mContext.ebx = context.uc_mcontext.gregs[REG_EBX];
-  mContextToFill->mContext.edx = context.uc_mcontext.gregs[REG_EDX];
-  mContextToFill->mContext.ecx = context.uc_mcontext.gregs[REG_ECX];
-  mContextToFill->mContext.eax = context.uc_mcontext.gregs[REG_EAX];
-  mContextToFill->mContext.ebp = context.uc_mcontext.gregs[REG_EBP];
-  mContextToFill->mContext.eip = context.uc_mcontext.gregs[REG_EIP];
-  mContextToFill->mContext.eflags = context.uc_mcontext.gregs[REG_EFL];
-  mContextToFill->mContext.esp = context.uc_mcontext.gregs[REG_ESP];
-#elif defined(MOZ_THREADSTACKHELPER_X64)
-  mContextToFill->mContext.context_flags = MD_CONTEXT_AMD64_FULL;
-  mContextToFill->mContext.eflags = uint32_t(context.uc_mcontext.gregs[REG_EFL]);
-  mContextToFill->mContext.rax = context.uc_mcontext.gregs[REG_RAX];
-  mContextToFill->mContext.rcx = context.uc_mcontext.gregs[REG_RCX];
-  mContextToFill->mContext.rdx = context.uc_mcontext.gregs[REG_RDX];
-  mContextToFill->mContext.rbx = context.uc_mcontext.gregs[REG_RBX];
-  mContextToFill->mContext.rsp = context.uc_mcontext.gregs[REG_RSP];
-  mContextToFill->mContext.rbp = context.uc_mcontext.gregs[REG_RBP];
-  mContextToFill->mContext.rsi = context.uc_mcontext.gregs[REG_RSI];
-  mContextToFill->mContext.rdi = context.uc_mcontext.gregs[REG_RDI];
-  memcpy(&mContextToFill->mContext.r8,
-         &context.uc_mcontext.gregs[REG_R8], 8 * sizeof(int64_t));
-  mContextToFill->mContext.rip = context.uc_mcontext.gregs[REG_RIP];
-#elif defined(MOZ_THREADSTACKHELPER_ARM)
-  mContextToFill->mContext.context_flags = MD_CONTEXT_ARM_FULL;
-  memcpy(&mContextToFill->mContext.iregs[0],
-         &context.uc_mcontext.arm_r0, 17 * sizeof(int32_t));
-#else
-  #error "Unsupported architecture"
-#endif // architecture
-
-#elif defined(XP_WIN)
-  // Breakpad context struct is based off of the Windows CONTEXT struct,
-  // so we assume they are the same; do some sanity checks to make sure.
-  static_assert(sizeof(ThreadContext::Context) == sizeof(::CONTEXT),
-                "Context struct mismatch");
-  static_assert(offsetof(ThreadContext::Context, context_flags) ==
-                offsetof(::CONTEXT, ContextFlags),
-                "Context struct mismatch");
-  mContextToFill->mContext.context_flags = CONTEXT_FULL;
-  NS_ENSURE_TRUE_VOID(::GetThreadContext(mThreadID,
-      reinterpret_cast<::CONTEXT*>(&mContextToFill->mContext)));
-
-#elif defined(XP_MACOSX)
-#if defined(MOZ_THREADSTACKHELPER_X86)
-  const thread_state_flavor_t flavor = x86_THREAD_STATE32;
-  x86_thread_state32_t state = {};
-  mach_msg_type_number_t count = x86_THREAD_STATE32_COUNT;
-#elif defined(MOZ_THREADSTACKHELPER_X64)
-  const thread_state_flavor_t flavor = x86_THREAD_STATE64;
-  x86_thread_state64_t state = {};
-  mach_msg_type_number_t count = x86_THREAD_STATE64_COUNT;
-#elif defined(MOZ_THREADSTACKHELPER_ARM)
-  const thread_state_flavor_t flavor = ARM_THREAD_STATE;
-  arm_thread_state_t state = {};
-  mach_msg_type_number_t count = ARM_THREAD_STATE_COUNT;
-#endif
-  NS_ENSURE_TRUE_VOID(KERN_SUCCESS == ::thread_get_state(
-    mThreadID, flavor, reinterpret_cast<thread_state_t>(&state), &count));
-#if __DARWIN_UNIX03
-#define GET_REGISTER(s, r) ((s).__##r)
-#else
-#define GET_REGISTER(s, r) ((s).r)
-#endif
-#if defined(MOZ_THREADSTACKHELPER_X86)
-  mContextToFill->mContext.context_flags = MD_CONTEXT_X86_FULL;
-  mContextToFill->mContext.edi = GET_REGISTER(state, edi);
-  mContextToFill->mContext.esi = GET_REGISTER(state, esi);
-  mContextToFill->mContext.ebx = GET_REGISTER(state, ebx);
-  mContextToFill->mContext.edx = GET_REGISTER(state, edx);
-  mContextToFill->mContext.ecx = GET_REGISTER(state, ecx);
-  mContextToFill->mContext.eax = GET_REGISTER(state, eax);
-  mContextToFill->mContext.ebp = GET_REGISTER(state, ebp);
-  mContextToFill->mContext.eip = GET_REGISTER(state, eip);
-  mContextToFill->mContext.eflags = GET_REGISTER(state, eflags);
-  mContextToFill->mContext.esp = GET_REGISTER(state, esp);
-#elif defined(MOZ_THREADSTACKHELPER_X64)
-  mContextToFill->mContext.context_flags = MD_CONTEXT_AMD64_FULL;
-  mContextToFill->mContext.eflags = uint32_t(GET_REGISTER(state, rflags));
-  mContextToFill->mContext.rax = GET_REGISTER(state, rax);
-  mContextToFill->mContext.rcx = GET_REGISTER(state, rcx);
-  mContextToFill->mContext.rdx = GET_REGISTER(state, rdx);
-  mContextToFill->mContext.rbx = GET_REGISTER(state, rbx);
-  mContextToFill->mContext.rsp = GET_REGISTER(state, rsp);
-  mContextToFill->mContext.rbp = GET_REGISTER(state, rbp);
-  mContextToFill->mContext.rsi = GET_REGISTER(state, rsi);
-  mContextToFill->mContext.rdi = GET_REGISTER(state, rdi);
-  memcpy(&mContextToFill->mContext.r8,
-         &GET_REGISTER(state, r8), 8 * sizeof(int64_t));
-  mContextToFill->mContext.rip = GET_REGISTER(state, rip);
-#elif defined(MOZ_THREADSTACKHELPER_ARM)
-  mContextToFill->mContext.context_flags = MD_CONTEXT_ARM_FULL;
-  memcpy(mContextToFill->mContext.iregs,
-         GET_REGISTER(state, r), 17 * sizeof(int32_t));
-#else
-  #error "Unsupported architecture"
-#endif // architecture
-#undef GET_REGISTER
-
-#else
-  #error "Unsupported platform"
-#endif // platform
-
-  intptr_t sp = 0;
-#if defined(MOZ_THREADSTACKHELPER_X86)
-  sp = mContextToFill->mContext.esp;
-#elif defined(MOZ_THREADSTACKHELPER_X64)
-  sp = mContextToFill->mContext.rsp;
-#elif defined(MOZ_THREADSTACKHELPER_ARM)
-  sp = mContextToFill->mContext.iregs[13];
-#else
-  #error "Unsupported architecture"
-#endif // architecture
-  NS_ENSURE_TRUE_VOID(sp);
-  NS_ENSURE_TRUE_VOID(mThreadStackBase);
-
-  size_t stackSize = std::min(intptr_t(ThreadContext::kMaxStackSize),
-                              std::abs(sp - mThreadStackBase));
-
-  if (mContextToFill->mStackEnd) {
-    // Limit the start of stack to a certain location if specified.
-    stackSize = std::min(intptr_t(stackSize),
-      std::abs(sp - intptr_t(mContextToFill->mStackEnd)));
-  }
-
-#ifndef MOZ_THREADSTACKHELPER_STACK_GROWS_DOWN
-  // If if the stack grows upwards, and we need to recalculate our
-  // stack copy's base address. Subtract sizeof(void*) so that the
-  // location pointed to by sp is included.
-  sp -= stackSize - sizeof(void*);
-#endif
-
-#ifndef MOZ_ASAN
-  memcpy(mContextToFill->mStack.get(), reinterpret_cast<void*>(sp), stackSize);
-  // Valgrind doesn't care about the access outside the stack frame, but
-  // the presence of uninitialised values on the stack does cause it to
-  // later report a lot of false errors when Breakpad comes to unwind it.
-  // So mark the extracted data as defined.
-  MOZ_MAKE_MEM_DEFINED(mContextToFill->mStack.get(), stackSize);
-#else
-  // ASan will flag memcpy for access outside of stack frames,
-  // so roll our own memcpy here.
-  intptr_t* dst = reinterpret_cast<intptr_t*>(&mContextToFill->mStack[0]);
-  const intptr_t* src = reinterpret_cast<intptr_t*>(sp);
-  for (intptr_t len = stackSize; len > 0; len -= sizeof(*src)) {
-    *(dst++) = *(src++);
-  }
-#endif
-
-  mContextToFill->mStackBase = uintptr_t(sp);
-  mContextToFill->mStackSize = stackSize;
-  mContextToFill->mValid = true;
-#endif
-#endif // MOZ_THREADSTACKHELPER_NATIVE
+  /*** STUB ***/
 }
 
 } // namespace mozilla
diff --git a/xpcom/threads/ThreadStackHelper.h b/xpcom/threads/ThreadStackHelper.h
index 9c40ad5e2f..f06e704b42 100644
--- a/xpcom/threads/ThreadStackHelper.h
+++ b/xpcom/threads/ThreadStackHelper.h
@@ -23,27 +23,6 @@
 #include <mach/mach.h>
 #endif
 
-// Support pseudostack on these platforms.
-#if defined(XP_LINUX) || defined(XP_WIN) || defined(XP_MACOSX)
-#  ifdef MOZ_ENABLE_PROFILER_SPS
-#    define MOZ_THREADSTACKHELPER_PSEUDO
-#  endif
-#endif
-
-#ifdef MOZ_THREADSTACKHELPER_PSEUDO
-#  define MOZ_THREADSTACKHELPER_NATIVE
-#  if defined(__i386__) || defined(_M_IX86)
-#    define MOZ_THREADSTACKHELPER_X86
-#  elif defined(__x86_64__) || defined(_M_X64)
-#    define MOZ_THREADSTACKHELPER_X64
-#  elif defined(__arm__) || defined(_M_ARM)
-#    define MOZ_THREADSTACKHELPER_ARM
-#  else
-     // Unsupported architecture
-#    undef MOZ_THREADSTACKHELPER_NATIVE
-#  endif
-#endif
-
 namespace mozilla {
 
 /**
@@ -63,29 +42,10 @@ public:
 
 private:
   Stack* mStackToFill;
-#ifdef MOZ_THREADSTACKHELPER_PSEUDO
-  const PseudoStack* const mPseudoStack;
-#ifdef MOZ_THREADSTACKHELPER_NATIVE
-  class ThreadContext;
-  // Set to non-null if GetStack should get the thread context.
-  ThreadContext* mContextToFill;
-  intptr_t mThreadStackBase;
-#endif
-  size_t mMaxStackSize;
-  size_t mMaxBufferSize;
-#endif
 
   bool PrepareStackBuffer(Stack& aStack);
   void FillStackBuffer();
   void FillThreadContext(void* aContext = nullptr);
-#ifdef MOZ_THREADSTACKHELPER_PSEUDO
-  const char* AppendJSEntry(const volatile StackEntry* aEntry,
-                            intptr_t& aAvailableBufferSize,
-                            const char* aPrevLabel);
-#endif
-#ifdef MOZ_THREADSTACKHELPER_NATIVE
-  void GetThreadStackBase();
-#endif
 
 public:
   /**