win: Implement exception snapshot

snapshot/win/exception_snapshot_win.cc

Index: snapshot/win/exception_snapshot_win.cc
diff --git a/snapshot/win/exception_snapshot_win.cc b/snapshot/win/exception_snapshot_win.cc
new file mode 100644
index 0000000000000000000000000000000000000000..40ac560bd5f1f17d22aac1e0eaa5a1245d0f9abf
--- /dev/null
+++ b/snapshot/win/exception_snapshot_win.cc
@@ -0,0 +1,150 @@
+// Copyright 2015 The Crashpad Authors. All rights reserved.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#include "snapshot/win/exception_snapshot_win.h"
+
+#include "snapshot/win/cpu_context_win.h"
+#include "snapshot/win/process_reader_win.h"
+#include "util/win/nt_internals.h"
+#include "util/win/process_structs.h"
+
+namespace crashpad {
+namespace internal {
+
+namespace {
+

[cpu_(ooo_6.6-7.5), 2015/05/15 01:24:13]

I must mention this somewhere but unrelated to this CL is that calling Nt
functions does not set the last error so GetLastError() contains basically
garbage. So some people add a SetLastError(NtStatusToDosError(nt_status)) after
each Nt call, others are careful to not assume... I am fine with either.

[scottmg, 2015/08/18 05:08:40]

Noted. I tried to use PLOG/LOG correctly, it's possible I missed some though.

+// ::GetThreadId is not available on XP, so get the thread id via
+// NtQueryInformationThread.
+template <class Traits>
+uint64_t GetThreadId(HANDLE handle) {
+  process_types::THREAD_BASIC_INFORMATION<Traits> basic_information;
+  if (!NT_SUCCESS(crashpad::NtQueryInformationThread(
+          handle,
+          static_cast<THREADINFOCLASS>(ThreadBasicInformation),
+          &basic_information,
+          sizeof(basic_information),
+          nullptr))) {
+    LOG(ERROR) << "could not retrieve ThreadBasicInformation";
+    return 0;
+  }
+  return basic_information.ClientId.UniqueThread;

[cpu_(ooo_6.6-7.5), 2015/05/15 01:24:12]

is it really the same as ::GetThreadId() ?  I mean I think its fine as a unique
identifier but reading the docs its not clear is the same.

[scottmg, 2015/08/18 05:08:40]

It is by testing (and ProcessHacker-ing, and it's how reactos implements
GetThreadId), but I can't find anywhere it's documented, unfortunately.

+}
+
+uint64_t GetThreadId(ProcessReaderWin* process_reader, HANDLE handle) {
+  if (process_reader->Is64Bit())
+    return GetThreadId<process_types::internal::Traits64>(handle);
+  else
+    return GetThreadId<process_types::internal::Traits32>(handle);
+}
+
+}  // namespace
+
+ExceptionSnapshotWin::ExceptionSnapshotWin()
+    : ExceptionSnapshot(),
+      context_union_(),
+      context_(),
+      codes_(),
+      thread_id_(0),
+      exception_address_(0),
+      exception_flags_(0),
+      exception_(0),
+      initialized_() {
+}
+
+ExceptionSnapshotWin::~ExceptionSnapshotWin() {
+}
+
+bool ExceptionSnapshotWin::Initialize(ProcessReaderWin* process_reader,
+                                      HANDLE thread_handle,
+                                      EXCEPTION_POINTERS* exception_pointers) {
+  INITIALIZATION_STATE_SET_INITIALIZING(initialized_);
+  DCHECK(exception_pointers);
+  if (!exception_pointers->ExceptionRecord) {
+    LOG(WARNING) << "null ExceptionRecord";
+    return false;
+  }
+  const EXCEPTION_RECORD& first_record = *exception_pointers->ExceptionRecord;
+  exception_ = first_record.ExceptionCode;
+  exception_flags_ = first_record.ExceptionFlags;
+  exception_address_ =
+      reinterpret_cast<uint64_t>(first_record.ExceptionAddress);
+  for (DWORD i = 0; i < first_record.NumberParameters; ++i)
+    codes_.push_back(first_record.ExceptionInformation[i]);
+
+  thread_id_ = GetThreadId(process_reader, thread_handle);
+
+  bool found_thread = false;
+  for (const auto& loop_thread : process_reader->Threads()) {
+    if (thread_id_ == loop_thread.id) {
+      found_thread = true;
+      break;
+    }
+  }
+
+  if (!found_thread) {
+    LOG(ERROR) << "thread_handle not found in process";
+    return false;
+  }
+
+#if defined(ARCH_CPU_X86_FAMILY)
+  if (process_reader->Is64Bit()) {
+    context_.architecture = kCPUArchitectureX86_64;
+    context_.x86_64 = &context_union_.x86_64;
+    InitializeX64Context(*exception_pointers->ContextRecord, context_.x86_64);
+  } else {
+    context_.architecture = kCPUArchitectureX86;
+    context_.x86 = &context_union_.x86;
+    InitializeX86Context(*exception_pointers->ContextRecord, context_.x86);
+  }
+#endif
+
+  if (first_record.ExceptionRecord)
+    LOG(WARNING) << "dropping chained ExceptionRecord";
+
+  INITIALIZATION_STATE_SET_VALID(initialized_);
+  return true;
+}
+
+const CPUContext* ExceptionSnapshotWin::Context() const {
+  INITIALIZATION_STATE_DCHECK_VALID(initialized_);
+  return &context_;
+}
+
+uint64_t ExceptionSnapshotWin::ThreadID() const {
+  INITIALIZATION_STATE_DCHECK_VALID(initialized_);
+  return thread_id_;
+}
+
+uint32_t ExceptionSnapshotWin::Exception() const {
+  INITIALIZATION_STATE_DCHECK_VALID(initialized_);
+  return exception_;
+}
+
+uint32_t ExceptionSnapshotWin::ExceptionInfo() const {
+  INITIALIZATION_STATE_DCHECK_VALID(initialized_);
+  return exception_flags_;
+}
+
+uint64_t ExceptionSnapshotWin::ExceptionAddress() const {
+  INITIALIZATION_STATE_DCHECK_VALID(initialized_);
+  return exception_address_;
+}
+
+const std::vector<uint64_t>& ExceptionSnapshotWin::Codes() const {
+  INITIALIZATION_STATE_DCHECK_VALID(initialized_);
+  return codes_;
+}
+
+}  // namespace internal
+}  // namespace crashpad