[Cleanup] Fix circular dependency on Windows.

Crashpad currently has a circular dependency: client->snapshot->client.

The dependency from snapshot -> client only exists to pull in a single
constant for Windows (CrashpadClient::kTriggeredExceptionCode), so this
change breaks the dependency by splitting the constant out into a new
file util/win/exception_codes.h.

Change-Id: I6b74b367df716e097758e63a44c53cb92ea5e04d
Reviewed-on: https://chromium-review.googlesource.com/c/crashpad/crashpad/+/3450763
Reviewed-by: Mark Mentovai <mark@chromium.org>
Commit-Queue: Justin Cohen <justincohen@chromium.org>

client/crashpad_client.h

@@ -702,17 +702,6 @@ class CrashpadClient {
   static bool DumpAndCrashTargetProcess(HANDLE process,
                                         HANDLE blame_thread,
                                         DWORD exception_code);
-
-  enum : uint32_t {
-    //! \brief The exception code (roughly "Client called") used when
-    //!     DumpAndCrashTargetProcess() triggers an exception in a target
-    //!     process.
-    //!
-    //! \note This value does not have any bits of the top nibble set, to avoid
-    //!     confusion with real exception codes which tend to have those bits
-    //!     set.
-    kTriggeredExceptionCode = 0xcca11ed,
-  };
 #endif
 
 #if BUILDFLAG(IS_APPLE) || DOXYGEN

client/crashpad_client_win.cc

@@ -36,6 +36,7 @@
 #include "util/win/command_line.h"
 #include "util/win/context_wrappers.h"
 #include "util/win/critical_section_with_debug_info.h"
+#include "util/win/exception_codes.h"
 #include "util/win/get_function.h"
 #include "util/win/handle.h"
 #include "util/win/initial_client_data.h"
@@ -926,7 +927,7 @@ bool CrashpadClient::DumpAndCrashTargetProcess(HANDLE process,
 
     // ecx = kTriggeredExceptionCode for dwExceptionCode.
     data_to_write.push_back(0xb9);
-    AddUint32(&data_to_write, kTriggeredExceptionCode);
+    AddUint32(&data_to_write, ExceptionCodes::kTriggeredExceptionCode);
 
     // jmp to RaiseException() via rax.
     data_to_write.push_back(0x48);  // mov rax, imm.

handler/win/crash_other_program.cc

@@ -24,6 +24,7 @@
 #include "test/test_paths.h"
 #include "test/win/child_launcher.h"
 #include "util/file/file_io.h"
+#include "util/win/exception_codes.h"
 #include "util/win/scoped_handle.h"
 #include "util/win/xp_compat.h"
 
@@ -108,7 +109,7 @@ int CrashOtherProgram(int argc, wchar_t* argv[]) {
 
   DWORD expect_exit_code;
   if (argc == 3 && wcscmp(argv[2], L"noexception") == 0) {
-    expect_exit_code = CrashpadClient::kTriggeredExceptionCode;
+    expect_exit_code = ExceptionCodes::kTriggeredExceptionCode;
     if (!CrashpadClient::DumpAndCrashTargetProcess(
             child.process_handle(), 0, 0))
       return EXIT_FAILURE;

snapshot/BUILD.gn

@@ -254,7 +254,6 @@ crashpad_static_library("snapshot") {
   ]
 
   if (crashpad_is_win) {
-    deps += [ "../client" ]
     cflags = [ "/wd4201" ]  # nonstandard extension used : nameless struct/union
     libs = [ "powrprof.lib" ]
   }
@@ -442,10 +441,6 @@ source_set("snapshot_test") {
     "../util",
   ]
 
-  if (crashpad_is_win) {
-    deps += [ "../client" ]
-  }
-
   if (crashpad_is_ios) {
     deps += [
       ":snapshot_test_ios_data",

snapshot/win/exception_snapshot_win.cc

@@ -15,13 +15,13 @@
 #include "snapshot/win/exception_snapshot_win.h"
 
 #include "base/logging.h"
-#include "client/crashpad_client.h"
 #include "snapshot/capture_memory.h"
 #include "snapshot/memory_snapshot.h"
 #include "snapshot/memory_snapshot_generic.h"
 #include "snapshot/win/capture_memory_delegate_win.h"
 #include "snapshot/win/cpu_context_win.h"
 #include "snapshot/win/process_reader_win.h"
+#include "util/win/exception_codes.h"
 #include "util/win/nt_internals.h"
 
 namespace crashpad {
@@ -215,7 +215,7 @@ bool ExceptionSnapshotWin::InitializeFromExceptionPointers(
   }
 
   const bool triggered_by_client =
-      first_record.ExceptionCode == CrashpadClient::kTriggeredExceptionCode &&
+      first_record.ExceptionCode == ExceptionCodes::kTriggeredExceptionCode &&
       first_record.NumberParameters == 2;
   if (triggered_by_client)
     process_reader->DecrementThreadSuspendCounts(exception_thread_id);

snapshot/win/exception_snapshot_win_test.cc

@@ -18,7 +18,6 @@
 
 #include "base/files/file_path.h"
 #include "base/strings/utf_string_conversions.h"
-#include "client/crashpad_client.h"
 #include "gtest/gtest.h"
 #include "snapshot/win/process_snapshot_win.h"
 #include "test/errors.h"

util/BUILD.gn

@@ -468,6 +468,7 @@ crashpad_static_library("util") {
       "win/critical_section_with_debug_info.h",
       "win/exception_handler_server.cc",
       "win/exception_handler_server.h",
+      "win/exception_codes.h",
       "win/get_function.cc",
       "win/get_function.h",
       "win/get_module_information.cc",

util/win/exception_codes.h

@@ -0,0 +1,37 @@
+// Copyright 2022 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.
+
+#ifndef CRASHPAD_UTIL_WIN_EXCEPTION_CODES_H_
+#define CRASHPAD_UTIL_WIN_EXCEPTION_CODES_H_
+
+#include <stdint.h>
+
+namespace crashpad {
+
+//! \brief Crashpad-specific exception codes that are used as arguments to
+//!     `RaiseException()` in unusual circumstances.
+enum ExceptionCodes : uint32_t {
+  //! \brief The exception code (roughly "Client called") used when
+  //!     DumpAndCrashTargetProcess() triggers an exception in a target
+  //!     process.
+  //!
+  //! \note This value does not have any bits of the top nibble set, to avoid
+  //!     confusion with real exception codes which tend to have those bits
+  //!     set.
+  kTriggeredExceptionCode = 0xcca11ed,
+};
+
+}  // namespace crashpad
+
+#endif  // CRASHPAD_UTIL_WIN_EXCEPTION_CODES_H_