Update clang, llvm, lld, lldb, compiler-rt and libc++ to 4.0.0 release:

MFC r309142 (by emaste):

Add WITH_LLD_AS_LD build knob

If set it installs LLD as /usr/bin/ld.  LLD (as of version 3.9) is not
capable of linking the world and kernel, but can self-host and link many
substantial applications. GNU ld continues to be used for the world and
kernel build, regardless of how this knob is set.

It is on by default for arm64, and off for all other CPU architectures.

Sponsored by:	The FreeBSD Foundation

MFC r310840:

Reapply 310775, now it also builds correctly if lldb is disabled:

Move llvm-objdump from CLANG_EXTRAS to installed by default

We currently install three tools from binutils 2.17.50: as, ld, and
objdump. Work is underway to migrate to a permissively-licensed
tool-chain, with one goal being the retirement of binutils 2.17.50.

LLVM's llvm-objdump is intended to be compatible with GNU objdump
although it is currently missing some options and may have formatting
differences. Enable it by default for testing and further investigation.
It may later be changed to install as /usr/bin/objdump, it becomes a
fully viable replacement.

Reviewed by:	emaste
Differential Revision:	https://reviews.freebsd.org/D8879

MFC r312855 (by emaste):

Rename LLD_AS_LD to LLD_IS_LD, for consistency with CLANG_IS_CC

Reported by:	Dan McGregor <dan.mcgregor usask.ca>

MFC r313559 | glebius | 2017-02-10 18:34:48 +0100 (Fri, 10 Feb 2017) | 5 lines

Don't check struct rtentry on FreeBSD, it is an internal kernel structure.
On other systems it may be API structure for SIOCADDRT/SIOCDELRT.

Reviewed by:	emaste, dim

MFC r314152 (by jkim):

Remove an assembler flag, which is redundant since r309124.  The upstream
took care of it by introducing a macro NO_EXEC_STACK_DIRECTIVE.

http://llvm.org/viewvc/llvm-project?rev=273500&view=rev

Reviewed by:	dim

MFC r314564:

Upgrade our copies of clang, llvm, lld, lldb, compiler-rt and libc++ to
4.0.0 (branches/release_40 296509).  The release will follow soon.

Please note that from 3.5.0 onwards, clang, llvm and lldb require C++11
support to build; see UPDATING for more information.

Also note that as of 4.0.0, lld should be able to link the base system
on amd64 and aarch64.  See the WITH_LLD_IS_LLD setting in src.conf(5).
Though please be aware that this is work in progress.

Release notes for llvm, clang and lld will be available here:
<http://releases.llvm.org/4.0.0/docs/ReleaseNotes.html>
<http://releases.llvm.org/4.0.0/tools/clang/docs/ReleaseNotes.html>
<http://releases.llvm.org/4.0.0/tools/lld/docs/ReleaseNotes.html>

Thanks to Ed Maste, Jan Beich, Antoine Brodin and Eric Fiselier for
their help.

Relnotes:	yes
Exp-run:	antoine
PR:		215969, 216008

MFC r314708:

For now, revert r287232 from upstream llvm trunk (by Daniil Fukalov):

  [SCEV] limit recursion depth of CompareSCEVComplexity

  Summary:
  CompareSCEVComplexity goes too deep (50+ on a quite a big unrolled
  loop) and runs almost infinite time.

  Added cache of "equal" SCEV pairs to earlier cutoff of further
  estimation. Recursion depth limit was also introduced as a parameter.

  Reviewers: sanjoy

  Subscribers: mzolotukhin, tstellarAMD, llvm-commits

  Differential Revision: https://reviews.llvm.org/D26389

This commit is the cause of excessive compile times on skein_block.c
(and possibly other files) during kernel builds on amd64.

We never saw the problematic behavior described in this upstream commit,
so for now it is better to revert it.  An upstream bug has been filed
here: https://bugs.llvm.org/show_bug.cgi?id=32142

Reported by:	mjg

MFC r314795:

Reapply r287232 from upstream llvm trunk (by Daniil Fukalov):

  [SCEV] limit recursion depth of CompareSCEVComplexity

  Summary:
  CompareSCEVComplexity goes too deep (50+ on a quite a big unrolled
  loop) and runs almost infinite time.

  Added cache of "equal" SCEV pairs to earlier cutoff of further
  estimation. Recursion depth limit was also introduced as a parameter.

  Reviewers: sanjoy

  Subscribers: mzolotukhin, tstellarAMD, llvm-commits

  Differential Revision: https://reviews.llvm.org/D26389

Pull in r296992 from upstream llvm trunk (by Sanjoy Das):

  [SCEV] Decrease the recursion threshold for CompareValueComplexity

  Fixes PR32142.

  r287232 accidentally increased the recursion threshold for
  CompareValueComplexity from 2 to 32.  This change reverses that
  change by introducing a separate flag for CompareValueComplexity's
  threshold.

The latter revision fixes the excessive compile times for skein_block.c.

MFC r314907 | mmel | 2017-03-08 12:40:27 +0100 (Wed, 08 Mar 2017) | 7 lines

Unbreak ARMv6 world.

The new compiler_rt library imported with clang 4.0.0 have several fatal
issues (non-functional __udivsi3 for example) with ARM specific instrict
functions. As temporary workaround, until upstream solve these problems,
disable all thumb[1][2] related feature.

MFC r315016:

Update clang, llvm, lld, lldb, compiler-rt and libc++ to 4.0.0 release.
We were already very close to the last release candidate, so this is a
pretty minor update.

Relnotes:	yes

MFC r316005:

Revert r314907, and pull in r298713 from upstream compiler-rt trunk (by
Weiming Zhao):

  builtins: Select correct code fragments when compiling for Thumb1/Thum2/ARM ISA.

  Summary:
  Value of __ARM_ARCH_ISA_THUMB isn't based on the actual compilation
  mode (-mthumb, -marm), it reflect's capability of given CPU.

  Due to this:
   - use  __tbumb__ and __thumb2__ insteand of __ARM_ARCH_ISA_THUMB
   - use '.thumb' directive consistently  in all affected files
   - decorate all thumb functions using
     DEFINE_COMPILERRT_THUMB_FUNCTION()

  ---------
  Note: This patch doesn't fix broken Thumb1 variant of __udivsi3 !

  Reviewers: weimingz, rengolin, compnerd

  Subscribers: aemerson, dim

  Differential Revision: https://reviews.llvm.org/D30938

Discussed with:	mmel

1 files changed, 543 insertions, 0 deletions

diff --git a/contrib/llvm/tools/lldb/source/Plugins/Process/Darwin/MachException.cpp b/contrib/llvm/tools/lldb/source/Plugins/Process/Darwin/MachException.cpp
new file mode 100644
index 0000000..8170644
--- /dev/null
+++ b/contrib/llvm/tools/lldb/source/Plugins/Process/Darwin/MachException.cpp
@@ -0,0 +1,543 @@
+//===-- MachException.cpp ---------------------------------------*- C++ -*-===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+//  Created by Greg Clayton on 6/18/07.
+//
+//===----------------------------------------------------------------------===//
+
+#include "MachException.h"
+
+// C includes
+#include <errno.h>
+#include <sys/ptrace.h>
+#include <sys/types.h>
+
+// C++ includes
+#include <mutex>
+
+// LLDB includes
+#include "lldb/Core/Error.h"
+#include "lldb/Core/Log.h"
+#include "lldb/Core/Stream.h"
+#include "lldb/Target/UnixSignals.h"
+#include "lldb/Utility/LLDBAssert.h"
+
+using namespace lldb;
+using namespace lldb_private;
+using namespace lldb_private::process_darwin;
+
+// Routine mach_exception_raise
+extern "C" kern_return_t
+catch_mach_exception_raise(mach_port_t exception_port, mach_port_t thread,
+                           mach_port_t task, exception_type_t exception,
+                           mach_exception_data_t code,
+                           mach_msg_type_number_t codeCnt);
+
+extern "C" kern_return_t catch_mach_exception_raise_state(
+    mach_port_t exception_port, exception_type_t exception,
+    const mach_exception_data_t code, mach_msg_type_number_t codeCnt,
+    int *flavor, const thread_state_t old_state,
+    mach_msg_type_number_t old_stateCnt, thread_state_t new_state,
+    mach_msg_type_number_t *new_stateCnt);
+
+// Routine mach_exception_raise_state_identity
+extern "C" kern_return_t catch_mach_exception_raise_state_identity(
+    mach_port_t exception_port, mach_port_t thread, mach_port_t task,
+    exception_type_t exception, mach_exception_data_t code,
+    mach_msg_type_number_t codeCnt, int *flavor, thread_state_t old_state,
+    mach_msg_type_number_t old_stateCnt, thread_state_t new_state,
+    mach_msg_type_number_t *new_stateCnt);
+
+extern "C" boolean_t mach_exc_server(mach_msg_header_t *InHeadP,
+                                     mach_msg_header_t *OutHeadP);
+
+// Any access to the g_message variable should be done by locking the
+// g_message_mutex first, using the g_message variable, then unlocking
+// the g_message_mutex. See MachException::Message::CatchExceptionRaise()
+// for sample code.
+
+static MachException::Data *g_message = NULL;
+
+extern "C" kern_return_t catch_mach_exception_raise_state(
+    mach_port_t exc_port, exception_type_t exc_type,
+    const mach_exception_data_t exc_data, mach_msg_type_number_t exc_data_count,
+    int *flavor, const thread_state_t old_state,
+    mach_msg_type_number_t old_stateCnt, thread_state_t new_state,
+    mach_msg_type_number_t *new_stateCnt) {
+  // TODO change to LIBLLDB_LOG_EXCEPTION
+  Log *log(GetLogIfAllCategoriesSet(LIBLLDB_LOG_PROCESS | LIBLLDB_LOG_VERBOSE));
+  if (log) {
+    log->Printf("::%s(exc_port = 0x%4.4x, exc_type = %d (%s), "
+                "exc_data = 0x%llx, exc_data_count = %d)",
+                __FUNCTION__, exc_port, exc_type, MachException::Name(exc_type),
+                (uint64_t)exc_data, exc_data_count);
+  }
+  return KERN_FAILURE;
+}
+
+extern "C" kern_return_t catch_mach_exception_raise_state_identity(
+    mach_port_t exc_port, mach_port_t thread_port, mach_port_t task_port,
+    exception_type_t exc_type, mach_exception_data_t exc_data,
+    mach_msg_type_number_t exc_data_count, int *flavor,
+    thread_state_t old_state, mach_msg_type_number_t old_stateCnt,
+    thread_state_t new_state, mach_msg_type_number_t *new_stateCnt) {
+  Log *log(GetLogIfAllCategoriesSet(LIBLLDB_LOG_PROCESS | LIBLLDB_LOG_VERBOSE));
+  if (log) {
+    log->Printf("::%s(exc_port = 0x%4.4x, thd_port = 0x%4.4x, "
+                "tsk_port = 0x%4.4x, exc_type = %d (%s), exc_data[%d] = "
+                "{ 0x%llx, 0x%llx })",
+                __FUNCTION__, exc_port, thread_port, task_port, exc_type,
+                MachException::Name(exc_type), exc_data_count,
+                (uint64_t)(exc_data_count > 0 ? exc_data[0] : 0xBADDBADD),
+                (uint64_t)(exc_data_count > 1 ? exc_data[1] : 0xBADDBADD));
+  }
+  mach_port_deallocate(mach_task_self(), task_port);
+  mach_port_deallocate(mach_task_self(), thread_port);
+
+  return KERN_FAILURE;
+}
+
+extern "C" kern_return_t
+catch_mach_exception_raise(mach_port_t exc_port, mach_port_t thread_port,
+                           mach_port_t task_port, exception_type_t exc_type,
+                           mach_exception_data_t exc_data,
+                           mach_msg_type_number_t exc_data_count) {
+  Log *log(GetLogIfAllCategoriesSet(LIBLLDB_LOG_PROCESS | LIBLLDB_LOG_VERBOSE));
+  if (log) {
+    log->Printf("::%s(exc_port = 0x%4.4x, thd_port = 0x%4.4x, "
+                "tsk_port = 0x%4.4x, exc_type = %d (%s), exc_data[%d] "
+                "= { 0x%llx, 0x%llx })",
+                __FUNCTION__, exc_port, thread_port, task_port, exc_type,
+                MachException::Name(exc_type), exc_data_count,
+                (uint64_t)(exc_data_count > 0 ? exc_data[0] : 0xBADDBADD),
+                (uint64_t)(exc_data_count > 1 ? exc_data[1] : 0xBADDBADD));
+  }
+
+  if (task_port == g_message->task_port) {
+    g_message->task_port = task_port;
+    g_message->thread_port = thread_port;
+    g_message->exc_type = exc_type;
+    g_message->exc_data.resize(exc_data_count);
+    ::memcpy(&g_message->exc_data[0], exc_data,
+             g_message->exc_data.size() * sizeof(mach_exception_data_type_t));
+    return KERN_SUCCESS;
+  }
+  return KERN_FAILURE;
+}
+
+#if 0
+void
+MachException::Message::Dump(Stream &stream) const
+{
+    stream.Printf("exc_msg { bits = 0x%8.8x size = 0x%8.8x remote-port = "
+                  "0x%8.8x local-port = 0x%8.8x reserved = 0x%8.8x "
+                  "id = 0x%8.8x }\n",
+        exc_msg.hdr.msgh_bits,
+        exc_msg.hdr.msgh_size,
+        exc_msg.hdr.msgh_remote_port,
+        exc_msg.hdr.msgh_local_port,
+        exc_msg.hdr.msgh_reserved,
+        exc_msg.hdr.msgh_id);
+
+    stream.Printf("reply_msg { bits = 0x%8.8x size = 0x%8.8x remote-port "
+                  "= 0x%8.8x local-port = 0x%8.8x reserved = 0x%8.8x "
+                  "id = 0x%8.8x }",
+                  reply_msg.hdr.msgh_bits,
+                  reply_msg.hdr.msgh_size,
+                  reply_msg.hdr.msgh_remote_port,
+                  reply_msg.hdr.msgh_local_port,
+                  reply_msg.hdr.msgh_reserved,
+                  reply_msg.hdr.msgh_id);
+    stream.Flush();
+}
+#endif
+
+bool MachException::Data::GetStopInfo(struct ThreadStopInfo *stop_info,
+                                      const UnixSignals &signals,
+                                      Stream &stream) const {
+  if (!stop_info)
+    return false;
+
+  // Zero out the structure.
+  memset(stop_info, 0, sizeof(struct ThreadStopInfo));
+
+  if (exc_type == 0) {
+    stop_info->reason = eStopReasonInvalid;
+    return true;
+  }
+
+  // We always stop with a mach exception.
+  stop_info->reason = eStopReasonException;
+  // Save the EXC_XXXX exception type.
+  stop_info->details.exception.type = exc_type;
+
+  // Fill in a text description
+  const char *exc_name = MachException::Name(exc_type);
+  if (exc_name)
+    stream.Printf("%s", exc_name);
+  else
+    stream.Printf("%i", exc_type);
+
+  stop_info->details.exception.data_count = exc_data.size();
+
+  int soft_signal = SoftSignal();
+  if (soft_signal) {
+    const char *sig_str = signals.GetSignalAsCString(soft_signal);
+    stream.Printf(" EXC_SOFT_SIGNAL( %i ( %s ))", soft_signal,
+                  sig_str ? sig_str : "unknown signal");
+  } else {
+    // No special disassembly for exception data, just print it.
+    size_t idx;
+    stream.Printf(" data[%llu] = {",
+                  (uint64_t)stop_info->details.exception.data_count);
+
+    for (idx = 0; idx < stop_info->details.exception.data_count; ++idx) {
+      stream.Printf(
+          "0x%llx%c", (uint64_t)exc_data[idx],
+          ((idx + 1 == stop_info->details.exception.data_count) ? '}' : ','));
+    }
+  }
+
+  // Copy the exception data
+  for (size_t i = 0; i < stop_info->details.exception.data_count; i++)
+    stop_info->details.exception.data[i] = exc_data[i];
+
+  return true;
+}
+
+Error MachException::Message::Receive(mach_port_t port,
+                                      mach_msg_option_t options,
+                                      mach_msg_timeout_t timeout,
+                                      mach_port_t notify_port) {
+  Error error;
+  Log *log(GetLogIfAllCategoriesSet(LIBLLDB_LOG_PROCESS | LIBLLDB_LOG_VERBOSE));
+
+  mach_msg_timeout_t mach_msg_timeout =
+      options & MACH_RCV_TIMEOUT ? timeout : 0;
+  if (log && ((options & MACH_RCV_TIMEOUT) == 0)) {
+    // Dump this log message if we have no timeout in case it never returns
+    log->Printf("::mach_msg(msg->{bits = %#x, size = %u remote_port = %#x, "
+                "local_port = %#x, reserved = 0x%x, id = 0x%x}, "
+                "option = %#x, send_size = 0, rcv_size = %llu, "
+                "rcv_name = %#x, timeout = %u, notify = %#x)",
+                exc_msg.hdr.msgh_bits, exc_msg.hdr.msgh_size,
+                exc_msg.hdr.msgh_remote_port, exc_msg.hdr.msgh_local_port,
+                exc_msg.hdr.msgh_reserved, exc_msg.hdr.msgh_id, options,
+                (uint64_t)sizeof(exc_msg.data), port, mach_msg_timeout,
+                notify_port);
+  }
+
+  mach_msg_return_t mach_err =
+      ::mach_msg(&exc_msg.hdr,
+                 options,              // options
+                 0,                    // Send size
+                 sizeof(exc_msg.data), // Receive size
+                 port,                 // exception port to watch for
+                                       // exception on
+                 mach_msg_timeout,     // timeout in msec (obeyed only
+                                       // if MACH_RCV_TIMEOUT is ORed
+                                       // into the options parameter)
+                 notify_port);
+  error.SetError(mach_err, eErrorTypeMachKernel);
+
+  // Dump any errors we get
+  if (error.Fail() && log) {
+    log->Printf("::mach_msg(msg->{bits = %#x, size = %u remote_port = %#x, "
+                "local_port = %#x, reserved = 0x%x, id = 0x%x}, "
+                "option = %#x, send_size = %u, rcv_size = %lu, rcv_name "
+                "= %#x, timeout = %u, notify = %#x) failed: %s",
+                exc_msg.hdr.msgh_bits, exc_msg.hdr.msgh_size,
+                exc_msg.hdr.msgh_remote_port, exc_msg.hdr.msgh_local_port,
+                exc_msg.hdr.msgh_reserved, exc_msg.hdr.msgh_id, options, 0,
+                sizeof(exc_msg.data), port, mach_msg_timeout, notify_port,
+                error.AsCString());
+  }
+  return error;
+}
+
+void MachException::Message::Dump(Stream &stream) const {
+  stream.Printf("  exc_msg { bits = 0x%8.8x size = 0x%8.8x remote-port = "
+                "0x%8.8x local-port = 0x%8.8x reserved = 0x%8.8x id = "
+                "0x%8.8x }\n",
+                exc_msg.hdr.msgh_bits, exc_msg.hdr.msgh_size,
+                exc_msg.hdr.msgh_remote_port, exc_msg.hdr.msgh_local_port,
+                exc_msg.hdr.msgh_reserved, exc_msg.hdr.msgh_id);
+
+  stream.Printf("  reply_msg { bits = 0x%8.8x size = 0x%8.8x remote-port = "
+                "0x%8.8x local-port = 0x%8.8x reserved = 0x%8.8x id = "
+                "0x%8.8x }",
+                reply_msg.hdr.msgh_bits, reply_msg.hdr.msgh_size,
+                reply_msg.hdr.msgh_remote_port, reply_msg.hdr.msgh_local_port,
+                reply_msg.hdr.msgh_reserved, reply_msg.hdr.msgh_id);
+}
+
+bool MachException::Message::CatchExceptionRaise(task_t task) {
+  bool success = false;
+  // locker will keep a mutex locked until it goes out of scope
+  //    PThreadMutex::Locker locker(&g_message_mutex);
+  //    DNBLogThreaded("calling  mach_exc_server");
+  state.task_port = task;
+  g_message = &state;
+  // The exc_server function is the MIG generated server handling function
+  // to handle messages from the kernel relating to the occurrence of an
+  // exception in a thread. Such messages are delivered to the exception port
+  // set via thread_set_exception_ports or task_set_exception_ports. When an
+  // exception occurs in a thread, the thread sends an exception message to
+  // its exception port, blocking in the kernel waiting for the receipt of a
+  // reply. The exc_server function performs all necessary argument handling
+  // for this kernel message and calls catch_exception_raise,
+  // catch_exception_raise_state or catch_exception_raise_state_identity,
+  // which should handle the exception. If the called routine returns
+  // KERN_SUCCESS, a reply message will be sent, allowing the thread to
+  // continue from the point of the exception; otherwise, no reply message
+  // is sent and the called routine must have dealt with the exception
+  // thread directly.
+  if (mach_exc_server(&exc_msg.hdr, &reply_msg.hdr)) {
+    success = true;
+  } else {
+    Log *log(
+        GetLogIfAllCategoriesSet(LIBLLDB_LOG_PROCESS | LIBLLDB_LOG_VERBOSE));
+    if (log)
+      log->Printf("MachException::Message::%s(): mach_exc_server "
+                  "returned zero...",
+                  __FUNCTION__);
+  }
+  g_message = NULL;
+  return success;
+}
+
+Error MachException::Message::Reply(::pid_t inferior_pid, task_t inferior_task,
+                                    int signal) {
+  // Reply to the exception...
+  Error error;
+
+  Log *log(GetLogIfAllCategoriesSet(LIBLLDB_LOG_PROCESS | LIBLLDB_LOG_VERBOSE));
+
+  // If we had a soft signal, we need to update the thread first so it can
+  // continue without signaling
+  int soft_signal = state.SoftSignal();
+  if (soft_signal) {
+    int state_pid = -1;
+    if (inferior_task == state.task_port) {
+      // This is our task, so we can update the signal to send to it
+      state_pid = inferior_pid;
+      soft_signal = signal;
+    } else {
+      auto mach_err = ::pid_for_task(state.task_port, &state_pid);
+      if (mach_err) {
+        error.SetError(mach_err, eErrorTypeMachKernel);
+        if (log)
+          log->Printf("MachException::Message::%s(): pid_for_task() "
+                      "failed: %s",
+                      __FUNCTION__, error.AsCString());
+        return error;
+      }
+    }
+
+    lldbassert(state_pid != -1);
+    if (state_pid != -1) {
+      errno = 0;
+      caddr_t thread_port_caddr = (caddr_t)(uintptr_t)state.thread_port;
+      if (::ptrace(PT_THUPDATE, state_pid, thread_port_caddr, soft_signal) != 0)
+        error.SetError(errno, eErrorTypePOSIX);
+
+      if (!error.Success()) {
+        if (log)
+          log->Printf("::ptrace(request = PT_THUPDATE, pid = "
+                      "0x%4.4x, tid = 0x%4.4x, signal = %i)",
+                      state_pid, state.thread_port, soft_signal);
+        return error;
+      }
+    }
+  }
+
+  if (log)
+    log->Printf("::mach_msg ( msg->{bits = %#x, size = %u, remote_port "
+                "= %#x, local_port = %#x, reserved = 0x%x, id = 0x%x}, "
+                "option = %#x, send_size = %u, rcv_size = %u, rcv_name "
+                "= %#x, timeout = %u, notify = %#x)",
+                reply_msg.hdr.msgh_bits, reply_msg.hdr.msgh_size,
+                reply_msg.hdr.msgh_remote_port, reply_msg.hdr.msgh_local_port,
+                reply_msg.hdr.msgh_reserved, reply_msg.hdr.msgh_id,
+                MACH_SEND_MSG | MACH_SEND_INTERRUPT, reply_msg.hdr.msgh_size, 0,
+                MACH_PORT_NULL, MACH_MSG_TIMEOUT_NONE, MACH_PORT_NULL);
+
+  auto mach_err =
+      ::mach_msg(&reply_msg.hdr, MACH_SEND_MSG | MACH_SEND_INTERRUPT,
+                 reply_msg.hdr.msgh_size, 0, MACH_PORT_NULL,
+                 MACH_MSG_TIMEOUT_NONE, MACH_PORT_NULL);
+  if (mach_err)
+    error.SetError(mach_err, eErrorTypeMachKernel);
+
+  // Log our error if we have one.
+  if (error.Fail() && log) {
+    if (error.GetError() == MACH_SEND_INTERRUPTED) {
+      log->PutCString("::mach_msg() - send interrupted");
+      // TODO: keep retrying to reply???
+    } else if (state.task_port == inferior_task) {
+      log->Printf("mach_msg(): returned an error when replying "
+                  "to a mach exception: error = %u (%s)",
+                  error.GetError(), error.AsCString());
+    } else {
+      log->Printf("::mach_msg() - failed (child of task): %u (%s)",
+                  error.GetError(), error.AsCString());
+    }
+  }
+
+  return error;
+}
+
+#define PREV_EXC_MASK_ALL                                                      \
+  (EXC_MASK_BAD_ACCESS | EXC_MASK_BAD_INSTRUCTION | EXC_MASK_ARITHMETIC |      \
+   EXC_MASK_EMULATION | EXC_MASK_SOFTWARE | EXC_MASK_BREAKPOINT |              \
+   EXC_MASK_SYSCALL | EXC_MASK_MACH_SYSCALL | EXC_MASK_RPC_ALERT |             \
+   EXC_MASK_MACHINE)
+
+// Don't listen for EXC_RESOURCE, it should really get handled by the system
+// handler.
+
+#ifndef EXC_RESOURCE
+#define EXC_RESOURCE 11
+#endif
+
+#ifndef EXC_MASK_RESOURCE
+#define EXC_MASK_RESOURCE (1 << EXC_RESOURCE)
+#endif
+
+#define LLDB_EXC_MASK (EXC_MASK_ALL & ~EXC_MASK_RESOURCE)
+
+Error MachException::PortInfo::Save(task_t task) {
+  Error error;
+  Log *log(GetLogIfAllCategoriesSet(LIBLLDB_LOG_PROCESS | LIBLLDB_LOG_VERBOSE));
+
+  if (log)
+    log->Printf("MachException::PortInfo::%s(task = 0x%4.4x)", __FUNCTION__,
+                task);
+
+  // Be careful to be able to have debugserver built on a newer OS than what
+  // it is currently running on by being able to start with all exceptions
+  // and back off to just what is supported on the current system
+  mask = LLDB_EXC_MASK;
+
+  count = (sizeof(ports) / sizeof(ports[0]));
+  auto mach_err = ::task_get_exception_ports(task, mask, masks, &count, ports,
+                                             behaviors, flavors);
+  if (mach_err)
+    error.SetError(mach_err, eErrorTypeMachKernel);
+
+  if (log) {
+    if (error.Success()) {
+      log->Printf("::task_get_exception_ports(task = 0x%4.4x, mask = "
+                  "0x%x, maskCnt => %u, ports, behaviors, flavors)",
+                  task, mask, count);
+    } else {
+      log->Printf("::task_get_exception_ports(task = 0x%4.4x, mask = 0x%x, "
+                  "maskCnt => %u, ports, behaviors, flavors) error: %u (%s)",
+                  task, mask, count, error.GetError(), error.AsCString());
+    }
+  }
+
+  if ((error.GetError() == KERN_INVALID_ARGUMENT) &&
+      (mask != PREV_EXC_MASK_ALL)) {
+    mask = PREV_EXC_MASK_ALL;
+    count = (sizeof(ports) / sizeof(ports[0]));
+    mach_err = ::task_get_exception_ports(task, mask, masks, &count, ports,
+                                          behaviors, flavors);
+    error.SetError(mach_err, eErrorTypeMachKernel);
+    if (log) {
+      if (error.Success()) {
+        log->Printf("::task_get_exception_ports(task = 0x%4.4x, "
+                    "mask = 0x%x, maskCnt => %u, ports, behaviors, "
+                    "flavors)",
+                    task, mask, count);
+      } else {
+        log->Printf("::task_get_exception_ports(task = 0x%4.4x, mask = "
+                    "0x%x, maskCnt => %u, ports, behaviors, flavors) "
+                    "error: %u (%s)",
+                    task, mask, count, error.GetError(), error.AsCString());
+      }
+    }
+  }
+  if (error.Fail()) {
+    mask = 0;
+    count = 0;
+  }
+  return error;
+}
+
+Error MachException::PortInfo::Restore(task_t task) {
+  Error error;
+
+  Log *log(GetLogIfAllCategoriesSet(LIBLLDB_LOG_PROCESS | LIBLLDB_LOG_VERBOSE));
+
+  if (log)
+    log->Printf("MachException::PortInfo::Restore(task = 0x%4.4x)", task);
+
+  uint32_t i = 0;
+  if (count > 0) {
+    for (i = 0; i < count; i++) {
+      auto mach_err = ::task_set_exception_ports(task, masks[i], ports[i],
+                                                 behaviors[i], flavors[i]);
+      if (mach_err)
+        error.SetError(mach_err, eErrorTypeMachKernel);
+      if (log) {
+        if (error.Success()) {
+          log->Printf("::task_set_exception_ports(task = 0x%4.4x, "
+                      "exception_mask = 0x%8.8x, new_port = 0x%4.4x, "
+                      "behavior = 0x%8.8x, new_flavor = 0x%8.8x)",
+                      task, masks[i], ports[i], behaviors[i], flavors[i]);
+        } else {
+          log->Printf("::task_set_exception_ports(task = 0x%4.4x, "
+                      "exception_mask = 0x%8.8x, new_port = 0x%4.4x, "
+                      "behavior = 0x%8.8x, new_flavor = 0x%8.8x): "
+                      "error %u (%s)",
+                      task, masks[i], ports[i], behaviors[i], flavors[i],
+                      error.GetError(), error.AsCString());
+        }
+      }
+
+      // Bail if we encounter any errors
+      if (error.Fail())
+        break;
+    }
+  }
+
+  count = 0;
+  return error;
+}
+
+const char *MachException::Name(exception_type_t exc_type) {
+  switch (exc_type) {
+  case EXC_BAD_ACCESS:
+    return "EXC_BAD_ACCESS";
+  case EXC_BAD_INSTRUCTION:
+    return "EXC_BAD_INSTRUCTION";
+  case EXC_ARITHMETIC:
+    return "EXC_ARITHMETIC";
+  case EXC_EMULATION:
+    return "EXC_EMULATION";
+  case EXC_SOFTWARE:
+    return "EXC_SOFTWARE";
+  case EXC_BREAKPOINT:
+    return "EXC_BREAKPOINT";
+  case EXC_SYSCALL:
+    return "EXC_SYSCALL";
+  case EXC_MACH_SYSCALL:
+    return "EXC_MACH_SYSCALL";
+  case EXC_RPC_ALERT:
+    return "EXC_RPC_ALERT";
+#ifdef EXC_CRASH
+  case EXC_CRASH:
+    return "EXC_CRASH";
+#endif
+  default:
+    break;
+  }
+  return NULL;
+}