QTest::CrashHandler: split into Unix and Windows (1/2)

This file is convoluted and hard to read due to #if all over the place.
Let's split the two very different implementations.

This is the first commit, which just copies the files around without any
changes, to help with Git history.

Change-Id: I758dad7a07d927ccb61dfffd0199fb5e1e544c98
Reviewed-by: Edward Welbourne <edward.welbourne@qt.io>
This commit is contained in:
Thiago Macieira 2025-05-14 21:44:20 -07:00
parent b6ffbebbbe
commit fddb6fceaa
3 changed files with 687 additions and 1 deletions

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@ -45,7 +45,7 @@ qt_internal_add_module(Test
qtestblacklist.cpp qtestblacklist_p.h
qtestcase.cpp qtestcase.h qtestcase_p.h
qtestcoreelement_p.h
qtestcrashhandler.cpp qtestcrashhandler_p.h
qtestcrashhandler_p.h
qtestdata.cpp qtestdata.h
qtestelement.cpp qtestelement_p.h
qtestelementattribute.cpp qtestelementattribute_p.h
@ -148,6 +148,16 @@ qt_internal_extend_target(Test CONDITION MACOS
${FWIOKit}
)
qt_internal_extend_target(Test CONDITION UNIX AND (NOT WASM OR QT_FEATURE_thread)
SOURCES
qtestcrashhandler_unix.cpp
)
qt_internal_extend_target(Test CONDITION WIN32
SOURCES
qtestcrashhandler_win.cpp
)
set(qt_tc_build_dir "$<TARGET_PROPERTY:QT_TESTCASE_BUILDDIR>")
set(qt_bool_tc_build_dir "$<BOOL:${qt_tc_build_dir}>")
set(qt_tc_build_dir_def

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@ -0,0 +1,676 @@
// Copyright (C) 2024 The Qt Company Ltd.
// Copyright (C) 2024 Intel Corporation.
// SPDX-License-Identifier: LicenseRef-Qt-Commercial OR LGPL-3.0-only OR GPL-2.0-only OR GPL-3.0-only
#include <QtTest/qtestcase.h>
#include <QtTest/private/qtestcrashhandler_p.h>
#include <QtTest/qtestassert.h>
#include <QtCore/qbytearray.h>
#include <QtCore/qcoreapplication.h>
#include <QtCore/qdebug.h>
#include <QtCore/qdir.h>
#include <QtCore/qdiriterator.h>
#include <QtCore/qfile.h>
#include <QtCore/qfileinfo.h>
#include <QtCore/qfloat16.h>
#include <QtCore/qlibraryinfo.h>
#include <QtCore/qlist.h>
#include <QtCore/qmetaobject.h>
#include <QtCore/qobject.h>
#include <QtCore/qstringlist.h>
#include <QtCore/qtemporarydir.h>
#include <QtCore/qthread.h>
#include <QtCore/qvarlengtharray.h>
#include <QtCore/private/qlocking_p.h>
#include <QtCore/private/qtools_p.h>
#include <QtCore/private/qwaitcondition_p.h>
#include <QtCore/qtestsupport_core.h>
#include <QtTest/private/qtestlog_p.h>
#include <QtTest/private/qtesttable_p.h>
#include <QtTest/qtestdata.h>
#include <QtTest/private/qtestresult_p.h>
#include <QtTest/private/qsignaldumper_p.h>
#include <QtTest/private/qbenchmark_p.h>
#if QT_CONFIG(batch_test_support)
#include <QtTest/private/qtestregistry_p.h>
#endif // QT_CONFIG(batch_test_support)
#include <QtTest/private/cycle_include_p.h>
#include <QtTest/private/qtestblacklist_p.h>
#if defined(HAVE_XCTEST)
#include <QtTest/private/qxctestlogger_p.h>
#endif
#if defined Q_OS_MACOS
#include <QtTest/private/qtestutil_macos_p.h>
#endif
#if defined(Q_OS_DARWIN)
#include <QtTest/private/qappletestlogger_p.h>
#endif
#if !defined(Q_OS_INTEGRITY) || __GHS_VERSION_NUMBER > 202014
# include <charconv>
#else
// Broken implementation, causes link failures just by #include'ing!
# undef __cpp_lib_to_chars // in case <version> was included
#endif
#include <stdio.h>
#include <stdlib.h>
#if defined(Q_OS_LINUX)
#include <sys/prctl.h>
#include <sys/types.h>
#include <fcntl.h>
#endif
#ifdef Q_OS_UNIX
#include <QtCore/private/qcore_unix_p.h>
#include <errno.h>
#if __has_include(<paths.h>)
# include <paths.h>
#endif
#include <signal.h>
#include <time.h>
#include <sys/mman.h>
#include <sys/wait.h>
#include <unistd.h>
# if !defined(Q_OS_INTEGRITY)
# include <sys/resource.h>
# endif
# ifndef _PATH_DEFPATH
# define _PATH_DEFPATH "/usr/bin:/bin"
# endif
# ifndef SIGSTKSZ
# define SIGSTKSZ 0 /* we have code to set the minimum */
# endif
# ifndef SA_RESETHAND
# define SA_RESETHAND 0
# endif
#endif
#if defined(Q_OS_MACOS)
#include <IOKit/pwr_mgt/IOPMLib.h>
#include <mach/task.h>
#include <mach/mach_init.h>
#include <CoreFoundation/CFPreferences.h>
#endif
#if defined(Q_OS_WASM)
#include <emscripten.h>
#endif
QT_BEGIN_NAMESPACE
using namespace Qt::StringLiterals;
namespace QTest {
namespace CrashHandler {
#if defined(Q_OS_UNIX) && (!defined(Q_OS_WASM) || QT_CONFIG(thread))
struct iovec IoVec(struct iovec vec)
{
return vec;
}
struct iovec IoVec(const char *str)
{
struct iovec r = {};
r.iov_base = const_cast<char *>(str);
r.iov_len = strlen(str);
return r;
}
struct iovec asyncSafeToString(int n, AsyncSafeIntBuffer &&result)
{
char *ptr = result.array.data();
if (false) {
#ifdef __cpp_lib_to_chars
} else if (auto r = std::to_chars(ptr, ptr + result.array.size(), n, 10); r.ec == std::errc{}) {
ptr = r.ptr;
#endif
} else {
// handle the sign
if (n < 0) {
*ptr++ = '-';
n = -n;
}
// find the highest power of the base that is less than this number
static constexpr int StartingDivider = ([]() {
int divider = 1;
for (int i = 0; i < std::numeric_limits<int>::digits10; ++i)
divider *= 10;
return divider;
}());
int divider = StartingDivider;
while (divider && n < divider)
divider /= 10;
// now convert to string
while (divider > 1) {
int quot = n / divider;
n = n % divider;
divider /= 10;
*ptr++ = quot + '0';
}
*ptr++ = n + '0';
}
#ifndef QT_NO_DEBUG
// this isn't necessary, it just helps in the debugger
*ptr = '\0';
#endif
struct iovec r;
r.iov_base = result.array.data();
r.iov_len = ptr - result.array.data();
return r;
};
#endif // defined(Q_OS_UNIX) && (!defined(Q_OS_WASM) || QT_CONFIG(thread))
bool alreadyDebugging()
{
#if defined(Q_OS_LINUX)
int fd = open("/proc/self/status", O_RDONLY);
if (fd == -1)
return false;
char buffer[2048];
ssize_t size = read(fd, buffer, sizeof(buffer) - 1);
if (size == -1) {
close(fd);
return false;
}
buffer[size] = 0;
const char tracerPidToken[] = "\nTracerPid:";
char *tracerPid = strstr(buffer, tracerPidToken);
if (!tracerPid) {
close(fd);
return false;
}
tracerPid += sizeof(tracerPidToken);
long int pid = strtol(tracerPid, &tracerPid, 10);
close(fd);
return pid != 0;
#elif defined(Q_OS_WIN)
return IsDebuggerPresent();
#elif defined(Q_OS_MACOS)
// Check if there is an exception handler for the process:
mach_msg_type_number_t portCount = 0;
exception_mask_t masks[EXC_TYPES_COUNT];
mach_port_t ports[EXC_TYPES_COUNT];
exception_behavior_t behaviors[EXC_TYPES_COUNT];
thread_state_flavor_t flavors[EXC_TYPES_COUNT];
exception_mask_t mask = EXC_MASK_ALL & ~(EXC_MASK_RESOURCE | EXC_MASK_GUARD);
kern_return_t result = task_get_exception_ports(mach_task_self(), mask, masks, &portCount,
ports, behaviors, flavors);
if (result == KERN_SUCCESS) {
for (mach_msg_type_number_t portIndex = 0; portIndex < portCount; ++portIndex) {
if (MACH_PORT_VALID(ports[portIndex])) {
return true;
}
}
}
return false;
#else
// TODO
return false;
#endif
}
namespace {
enum DebuggerProgram { None, Gdb, Lldb };
static bool hasSystemCrashReporter()
{
#if defined(Q_OS_MACOS)
return QTestPrivate::macCrashReporterWillShowDialog();
#else
return false;
#endif
}
} // unnamed namespaced
void maybeDisableCoreDump()
{
#ifdef RLIMIT_CORE
bool ok = false;
const int disableCoreDump = qEnvironmentVariableIntValue("QTEST_DISABLE_CORE_DUMP", &ok);
if (ok && disableCoreDump) {
struct rlimit limit;
limit.rlim_cur = 0;
limit.rlim_max = 0;
if (setrlimit(RLIMIT_CORE, &limit) != 0)
qWarning("Failed to disable core dumps: %d", errno);
}
#endif
}
static DebuggerProgram debugger = None;
void prepareStackTrace()
{
bool ok = false;
const int disableStackDump = qEnvironmentVariableIntValue("QTEST_DISABLE_STACK_DUMP", &ok);
if (ok && disableStackDump)
return;
if (hasSystemCrashReporter())
return;
#if defined(Q_OS_MACOS)
// Try to handle https://github.com/llvm/llvm-project/issues/53254,
// where LLDB will hang and fail to provide a valid stack trace.
# if defined(Q_PROCESSOR_ARM)
return;
#else
#define CSR_ALLOW_UNRESTRICTED_FS (1 << 1)
std::optional<uint32_t> sipConfiguration = qt_mac_sipConfiguration();
if (!sipConfiguration || !(*sipConfiguration & CSR_ALLOW_UNRESTRICTED_FS))
return;
# endif
#endif
#ifdef Q_OS_UNIX
// like QStandardPaths::findExecutable(), but simpler
auto hasExecutable = [](const char *execname) {
std::string candidate;
std::string path;
if (const char *p = getenv("PATH"); p && *p)
path = p;
else
path = _PATH_DEFPATH;
for (const char *p = std::strtok(&path[0], ":'"); p; p = std::strtok(nullptr, ":")) {
candidate = p;
candidate += '/';
candidate += execname;
if (QT_ACCESS(candidate.data(), X_OK) == 0)
return true;
}
return false;
};
static constexpr DebuggerProgram debuggerSearchOrder[] = {
# if defined(Q_OS_QNX) || (defined(Q_OS_LINUX) && !defined(Q_OS_ANDROID))
Gdb, Lldb
# else
Lldb, Gdb
# endif
};
for (DebuggerProgram candidate : debuggerSearchOrder) {
switch (candidate) {
case None:
Q_UNREACHABLE();
break;
case Gdb:
if (hasExecutable("gdb")) {
debugger = Gdb;
return;
}
break;
case Lldb:
if (hasExecutable("lldb")) {
debugger = Lldb;
return;
}
break;
}
}
#endif // Q_OS_UNIX
}
#if !defined(Q_OS_WASM) || QT_CONFIG(thread)
void printTestRunTime()
{
const int msecsFunctionTime = qRound(QTestLog::msecsFunctionTime());
const int msecsTotalTime = qRound(QTestLog::msecsTotalTime());
const char *const name = QTest::currentTestFunction();
writeToStderr("\n ", name ? name : "[Non-test]",
" function time: ", asyncSafeToString(msecsFunctionTime),
"ms, total time: ", asyncSafeToString(msecsTotalTime), "ms\n");
}
void generateStackTrace()
{
if (debugger == None || alreadyDebugging())
return;
# if defined(Q_OS_LINUX) && defined(PR_SET_PTRACER)
// allow ourselves to be debugged
(void) prctl(PR_SET_PTRACER, PR_SET_PTRACER_ANY);
# endif
# if defined(Q_OS_UNIX) && !defined(Q_OS_WASM) && !defined(Q_OS_INTEGRITY) && !defined(Q_OS_VXWORKS)
writeToStderr("\n=== Stack trace ===\n");
// execlp() requires null-termination, so call the default constructor
AsyncSafeIntBuffer pidbuffer;
asyncSafeToString(getpid(), std::move(pidbuffer));
// Note: POSIX.1-2001 still has fork() in the list of async-safe functions,
// but in a future edition, it might be removed. It would be safer to wake
// up a babysitter thread to launch the debugger.
pid_t pid = fork();
if (pid == 0) {
// child process
(void) dup2(STDERR_FILENO, STDOUT_FILENO); // redirect stdout to stderr
switch (debugger) {
case None:
Q_UNREACHABLE();
break;
case Gdb:
execlp("gdb", "gdb", "--nx", "--batch", "-ex", "thread apply all bt",
"-ex", "info proc mappings",
"--pid", pidbuffer.array.data(), nullptr);
break;
case Lldb:
execlp("lldb", "lldb", "--no-lldbinit", "--batch", "-o", "bt all",
"--attach-pid", pidbuffer.array.data(), nullptr);
break;
}
_exit(1);
} else if (pid < 0) {
writeToStderr("Failed to start debugger.\n");
} else {
int ret;
QT_EINTR_LOOP(ret, waitpid(pid, nullptr, 0));
}
writeToStderr("=== End of stack trace ===\n");
# endif // Q_OS_UNIX && !Q_OS_WASM && !Q_OS_INTEGRITY && !Q_OS_VXWORKS
}
#endif // !defined(Q_OS_WASM) || QT_CONFIG(thread)
#if defined(Q_OS_WIN)
void blockUnixSignals()
{
// Windows does have C signals, but doesn't use them for the purposes we're
// talking about here
}
#elif defined(Q_OS_UNIX) && !defined(Q_OS_WASM)
void blockUnixSignals()
{
// Block most Unix signals so the WatchDog thread won't be called when
// external signals are delivered, thus avoiding interfering with the test
sigset_t set;
sigfillset(&set);
// we allow the crashing signals, in case we have bugs
for (int signo : FatalSignalHandler::fatalSignals)
sigdelset(&set, signo);
pthread_sigmask(SIG_BLOCK, &set, nullptr);
}
#endif // Q_OS_* choice
#if defined(Q_OS_WIN)
void DebugSymbolResolver::cleanup()
{
if (m_dbgHelpLib)
FreeLibrary(m_dbgHelpLib);
m_dbgHelpLib = 0;
m_symFromAddr = nullptr;
}
DebugSymbolResolver::DebugSymbolResolver(HANDLE process)
: m_process(process), m_dbgHelpLib(0), m_symFromAddr(nullptr)
{
bool success = false;
m_dbgHelpLib = LoadLibraryW(L"dbghelp.dll");
if (m_dbgHelpLib) {
SymInitializeType symInitialize = reinterpret_cast<SymInitializeType>(
reinterpret_cast<QFunctionPointer>(GetProcAddress(m_dbgHelpLib, "SymInitialize")));
m_symFromAddr = reinterpret_cast<SymFromAddrType>(
reinterpret_cast<QFunctionPointer>(GetProcAddress(m_dbgHelpLib, "SymFromAddr")));
success = symInitialize && m_symFromAddr && symInitialize(process, NULL, TRUE);
}
if (!success)
cleanup();
}
DebugSymbolResolver::Symbol DebugSymbolResolver::resolveSymbol(DWORD64 address) const
{
// reserve additional buffer where SymFromAddr() will store the name
struct NamedSymbolInfo : public DBGHELP_SYMBOL_INFO {
enum { symbolNameLength = 255 };
char name[symbolNameLength + 1];
};
Symbol result;
if (!isValid())
return result;
NamedSymbolInfo symbolBuffer;
memset(&symbolBuffer, 0, sizeof(NamedSymbolInfo));
symbolBuffer.MaxNameLen = NamedSymbolInfo::symbolNameLength;
symbolBuffer.SizeOfStruct = sizeof(DBGHELP_SYMBOL_INFO);
if (!m_symFromAddr(m_process, address, 0, &symbolBuffer))
return result;
result.name = qstrdup(symbolBuffer.Name);
result.address = symbolBuffer.Address;
return result;
}
WindowsFaultHandler::WindowsFaultHandler()
{
# if !defined(Q_CC_MINGW)
_CrtSetReportMode(_CRT_ERROR, _CRTDBG_MODE_DEBUG);
# endif
SetErrorMode(SetErrorMode(0) | SEM_NOGPFAULTERRORBOX);
SetUnhandledExceptionFilter(windowsFaultHandler);
}
LONG WINAPI WindowsFaultHandler::windowsFaultHandler(struct _EXCEPTION_POINTERS *exInfo)
{
enum { maxStackFrames = 100 };
char appName[MAX_PATH];
if (!GetModuleFileNameA(NULL, appName, MAX_PATH))
appName[0] = 0;
const int msecsFunctionTime = qRound(QTestLog::msecsFunctionTime());
const int msecsTotalTime = qRound(QTestLog::msecsTotalTime());
const void *exceptionAddress = exInfo->ExceptionRecord->ExceptionAddress;
fprintf(stderr, "A crash occurred in %s.\n", appName);
if (const char *name = QTest::currentTestFunction())
fprintf(stderr, "While testing %s\n", name);
fprintf(stderr, "Function time: %dms Total time: %dms\n\n"
"Exception address: 0x%p\n"
"Exception code : 0x%lx\n",
msecsFunctionTime, msecsTotalTime, exceptionAddress,
exInfo->ExceptionRecord->ExceptionCode);
DebugSymbolResolver resolver(GetCurrentProcess());
if (resolver.isValid()) {
DebugSymbolResolver::Symbol exceptionSymbol = resolver.resolveSymbol(DWORD64(exceptionAddress));
if (exceptionSymbol.name) {
fprintf(stderr, "Nearby symbol : %s\n", exceptionSymbol.name);
delete [] exceptionSymbol.name;
}
Q_DECL_UNINITIALIZED void *stack[maxStackFrames];
fputs("\nStack:\n", stderr);
const unsigned frameCount = CaptureStackBackTrace(0, DWORD(maxStackFrames), stack, NULL);
for (unsigned f = 0; f < frameCount; ++f) {
DebugSymbolResolver::Symbol symbol = resolver.resolveSymbol(DWORD64(stack[f]));
if (symbol.name) {
fprintf(stderr, "#%3u: %s() - 0x%p\n", f + 1, symbol.name, (const void *)symbol.address);
delete [] symbol.name;
} else {
fprintf(stderr, "#%3u: Unable to obtain symbol\n", f + 1);
}
}
}
fputc('\n', stderr);
return EXCEPTION_EXECUTE_HANDLER;
}
#elif defined(Q_OS_UNIX) && !defined(Q_OS_WASM)
bool FatalSignalHandler::pauseOnCrash = false;
FatalSignalHandler::FatalSignalHandler()
{
pauseOnCrash = qEnvironmentVariableIsSet("QTEST_PAUSE_ON_CRASH");
struct sigaction act;
memset(&act, 0, sizeof(act));
act.sa_handler = SIG_DFL;
oldActions().fill(act);
// Remove the handler after it is invoked.
act.sa_flags = SA_RESETHAND | setupAlternateStack();
# ifdef SA_SIGINFO
act.sa_flags |= SA_SIGINFO;
act.sa_sigaction = FatalSignalHandler::actionHandler;
# else
act.sa_handler = FatalSignalHandler::regularHandler;
# endif
// Block all fatal signals in our signal handler so we don't try to close
// the testlog twice.
sigemptyset(&act.sa_mask);
for (int signal : fatalSignals)
sigaddset(&act.sa_mask, signal);
for (size_t i = 0; i < fatalSignals.size(); ++i)
sigaction(fatalSignals[i], &act, &oldActions()[i]);
}
FatalSignalHandler::~FatalSignalHandler()
{
// Restore the default signal handlers in place of ours.
// If ours has been replaced, leave the replacement alone.
auto isOurs = [](const struct sigaction &old) {
# ifdef SA_SIGINFO
return (old.sa_flags & SA_SIGINFO) && old.sa_sigaction == FatalSignalHandler::actionHandler;
# else
return old.sa_handler == FatalSignalHandler::regularHandler;
# endif
};
struct sigaction action;
for (size_t i = 0; i < fatalSignals.size(); ++i) {
struct sigaction &act = oldActions()[i];
if (sigaction(fatalSignals[i], nullptr, &action))
continue; // Failed to query present handler
if (action.sa_flags == 0 && action.sa_handler == SIG_DFL)
continue; // Already the default
if (isOurs(action))
sigaction(fatalSignals[i], &act, nullptr);
}
freeAlternateStack();
}
FatalSignalHandler::OldActionsArray &FatalSignalHandler::oldActions()
{
Q_CONSTINIT static OldActionsArray oldActions {};
return oldActions;
}
auto FatalSignalHandler::alternateStackSize()
{
struct R { size_t size, pageSize; };
static constexpr size_t MinStackSize = 32 * 1024;
size_t pageSize = sysconf(_SC_PAGESIZE);
size_t size = SIGSTKSZ;
if (size < MinStackSize) {
size = MinStackSize;
} else {
// round up to a page
size = (size + pageSize - 1) & -pageSize;
}
return R{ size + pageSize, pageSize };
}
int FatalSignalHandler::setupAlternateStack()
{
// tvOS/watchOS both define SA_ONSTACK (in sys/signal.h) but mark sigaltstack() as
// unavailable (__WATCHOS_PROHIBITED __TVOS_PROHIBITED in signal.h)
# if defined(SA_ONSTACK) && !defined(Q_OS_TVOS) && !defined(Q_OS_WATCHOS)
// Let the signal handlers use an alternate stack
// This is necessary if SIGSEGV is to catch a stack overflow
auto r = alternateStackSize();
int flags = MAP_PRIVATE | MAP_ANONYMOUS;
# ifdef MAP_STACK
flags |= MAP_STACK;
# endif
alternateStackBase = mmap(nullptr, r.size, PROT_READ | PROT_WRITE, flags, -1, 0);
if (alternateStackBase == MAP_FAILED)
return 0;
// mark the bottom page inaccessible, to catch a handler stack overflow
(void) mprotect(alternateStackBase, r.pageSize, PROT_NONE);
stack_t stack;
stack.ss_flags = 0;
stack.ss_size = r.size - r.pageSize;
stack.ss_sp = static_cast<char *>(alternateStackBase) + r.pageSize;
sigaltstack(&stack, nullptr);
return SA_ONSTACK;
# else
return 0;
# endif
}
void FatalSignalHandler::freeAlternateStack()
{
# if defined(SA_ONSTACK) && !defined(Q_OS_TVOS) && !defined(Q_OS_WATCHOS)
if (alternateStackBase != MAP_FAILED) {
stack_t stack = {};
stack.ss_flags = SS_DISABLE;
sigaltstack(&stack, nullptr);
munmap(alternateStackBase, alternateStackSize().size);
}
# endif
}
void FatalSignalHandler::actionHandler(int signum, siginfo_t *info, void *)
{
writeToStderr("Received signal ", asyncSafeToString(signum),
" (SIG", signalName(signum), ")");
bool isCrashingSignal =
std::find(crashingSignals.begin(), crashingSignals.end(), signum) != crashingSignals.end();
if (isCrashingSignal && (!info || info->si_code <= 0))
isCrashingSignal = false; // wasn't sent by the kernel, so it's not really a crash
if (isCrashingSignal)
printCrashingSignalInfo(info);
else if (info && (info->si_code == SI_USER || info->si_code == SI_QUEUE))
printSentSignalInfo(info);
printTestRunTime();
if (signum != SIGINT) {
generateStackTrace();
if (pauseOnCrash) {
writeToStderr("Pausing process ", asyncSafeToString(getpid()),
" for debugging\n");
raise(SIGSTOP);
}
}
// chain back to the previous handler, if any
for (size_t i = 0; i < fatalSignals.size(); ++i) {
struct sigaction &act = oldActions()[i];
if (signum != fatalSignals[i])
continue;
// restore the handler (if SA_RESETHAND hasn't done the job for us)
if (SA_RESETHAND == 0 || act.sa_handler != SIG_DFL || act.sa_flags)
(void) sigaction(signum, &act, nullptr);
if (!isCrashingSignal)
raise(signum);
// signal is blocked, so it'll be delivered when we return
return;
}
// we shouldn't reach here!
std::abort();
}
#endif // defined(Q_OS_UNIX) && !defined(Q_OS_WASM)
} // namespace CrashHandler
} // namespace QTest
QT_END_NAMESPACE