更新CLion与MinGW后Qt6应用eventFilter触发SIGILL非法指令错误

在CLion中使用CMake构建Qt6应用，此前运行完全正常。更新CLion及其捆绑的完整MinGW工具链后，应用开始抛出SIGILL错误，经排查该错误触发于所有eventFilter函数中。

GDB输出信息 #

[New Thread 2036.0xe58]
[New Thread 2036.0x3be8]
[New Thread 2036.0x1f40]
[New Thread 2036.0x28e8]
[New Thread 2036.0x1f04]

Thread 1 hit Breakpoint 1, PermanentInventory::PermanentInventory (this=0xdd3da0, parent=0x0) at C:/Users/mmonfort/DEV-SPACE/prigo-economat/client/prico-economat-client/src/PermanentInventory.cpp:16
16      _ui->setupUi(this);
The target architecture is set to "auto" (currently "i386:x86-64").
warning: QLayout: Attempting to add QLayout "" to ConsumableInventory "consinventory_tab", which already has a layout
[New Thread 2036.0x3150]

Thread 1 received signal SIGILL, Illegal instruction.
0x00007ff77d114935 in ConsumableInventory::eventFilter (this=0xe63f30, watched=0xe65ab0, event=0x5ff9e0) at C:/Users/mmonfort/DEV-SPACE/prigo-economat/client/prico-economat-client/src/ConsumableInventory.cpp:50
50              search();

回溯信息 #

#0  0x00007ff77d114935 in ConsumableInventory::eventFilter (this=0xe63f30, watched=0xe65ab0, event=0x5ff9e0) at C:/Users/mmonfort/DEV-SPACE/prigo-economat/client/prico-economat-client/src/ConsumableInventory.cpp:50
#1  0x00007ff9b670f698 in QCoreApplicationPrivate::canQuitAutomatically() () from C:\Users\mmonfort\DEV-SPACE\prigo-economat\client\cmake-build-debug\prico-economat-client\Qt6Core.dll
#2  0x00007ff987b85055 in QApplicationPrivate::notify_helper(QObject*, QEvent*) () from C:\Users\mmonfort\DEV-SPACE\prigo-economat\client\cmake-build-debug\prico-economat-client\Qt6Widgets.dll
#3  0x00007ff9b6710b78 in QCoreApplication::sendEvent(QObject*, QEvent*) () from C:\Users\mmonfort\DEV-SPACE\prigo-economat\client\cmake-build-debug\prico-economat-client\Qt6Core.dll
#4  0x00007ff987bc6d8a in QWidget::ensurePolished() const () from C:\Users\mmonfort\DEV-SPACE\prigo-economat\client\cmake-build-debug\prico-economat-client\Qt6Widgets.dll
#5  0x00007ff987bc6dbb in QWidget::ensurePolished() const () from C:\Users\mmonfort\DEV-SPACE\prigo-economat\client\cmake-build-debug\prico-economat-client\Qt6Widgets.dll
#6  0x00007ff987bc6dbb in QWidget::ensurePolished() const () from C:\Users\mmonfort\DEV-SPACE\prigo-economat\client\cmake-build-debug\prico-economat-client\Qt6Widgets.dll
#7  0x00007ff987bc6dbb in QWidget::ensurePolished() const () from C:\Users\mmonfort\DEV-SPACE\prigo-economat\client\cmake-build-debug\prico-economat-client\Qt6Widgets.dll
#8  0x00007ff987bc6dbb in QWidget::ensurePolished() const () from C:\Users\mmonfort\DEV-SPACE\prigo-economat\client\cmake-build-debug\prico-economat-client\Qt6Widgets.dll
#9  0x00007ff987bc6dbb in QWidget::ensurePolished() const () from C:\Users\mmonfort\DEV-SPACE\prigo-economat\client\cmake-build-debug\prico-economat-client\Qt6Widgets.dll
#10 0x00007ff987bc9c3d in QWidgetPrivate::setVisible(bool) () from C:\Users\mmonfort\DEV-SPACE\prigo-economat\client\cmake-build-debug\prico-economat-client\Qt6Widgets.dll
#11 0x00007ff77d116a3c in main (argc=1, argv=0xd919f0) at C:/Users/mmonfort/DEV-SPACE/prigo-economat/client/prico-economat-client/src/main.cpp:14
#12 0x00007ff77d111340 in __tmainCRTStartup ()
#13 0x00007ff77d111146 in mainCRTStartup ()
#14 0x00007ffa03e07344 in KERNEL32!BaseThreadInitThunk () from C:\Windows\System32\kernel32.dll
#15 0x00007ffa05d426b1 in ntdll!RtlUserThreadStart () from C:\Windows\SYSTEM32\ntdll.dll
#16 0x0000000000000000 in ?? ()
Backtrace stopped: previous frame inner to this frame (corrupt stack?)

触发错误的代码 #

bool PermanentInventory::eventFilter(QObject *watched, QEvent *event) {
    if(event->type() == QEvent::KeyPress && watched == _ui->perminventory_searchedit){
        if(((QKeyEvent*)event)->key() == Qt::Key_Enter ||((QKeyEvent*)event)->key() == Qt::Key_Return){
            search();
        }
    }
}

反汇编代码（末尾含ud2指令） #

PermanentInventory::eventFilter(QObject*, QEvent*):
    push   %rbp                     
    mov    %rsp,%rbp                
    sub    $0x20,%rsp               
    mov    %rcx,0x10(%rbp)          
    mov    %rdx,0x18(%rbp)          
    mov    %r8,0x20(%rbp)           
    mov    0x20(%rbp),%rax          
    mov    %rax,%rcx                
    call   0x7ff6ccd16ed0 <QEvent::type() const>
    cmp    $0x6,%eax                
    jne    0x7ff6cccc7ad4 <PermanentInventory::eventFilter(QObject*, QEvent*)+62>
    mov    0x10(%rbp),%rax          
    mov    0x28(%rax),%rax          
    mov    0x10(%rax),%rax          
    cmp    %rax,0x18(%rbp)          
    jne    0x7ff6cccc7ad4 <PermanentInventory::eventFilter(QObject*, QEvent*)+62>
    mov    $0x1,%eax                
    jmp    0x7ff6cccc7ad9 <PermanentInventory::eventFilter(QObject*, QEvent*)+67>
    mov    $0x0,%eax                
    test   %al,%al                  
    je     0x7ff6cccc7b1f <PermanentInventory::eventFilter(QObject*, QEvent*)+137>
    mov    0x20(%rbp),%rax          
    mov    %rax,%rcx                
    call   0x7ff6ccd18540 <QKeyEvent::key() const>
    cmp    $0x1000005,%eax          
    je     0x7ff6cccc7b03 <PermanentInventory::eventFilter(QObject*, QEvent*)+109>
    mov    0x20(%rbp),%rax          
    mov    %rax,%rcx                
    call   0x7ff6ccd18540 <QKeyEvent::key() const>
    cmp    $0x1000004,%eax          
    jne    0x7ff6cccc7b0a <PermanentInventory::eventFilter(QObject*, QEvent*)+116>
    mov    $0x1,%eax                
    jmp    0x7ff6cccc7b0f <PermanentInventory::eventFilter(QObject*, QEvent*)+121>
    mov    $0x0,%eax                
    test   %al,%al                  
    je     0x7ff6cccc7b1f <PermanentInventory::eventFilter(QObject*, QEvent*)+137>
    mov    0x10(%rbp),%rax          
    mov    %rax,%rcx                
    call   0x7ff6cccc83dc <PermanentInventory::search()>
    ud2                          

问题原因与解决方法 #

原因 #

反汇编末尾的ud2是编译器插入的非法指令，用于标记未定义行为。问题出在eventFilter函数：该函数声明返回bool类型，但代码中没有任何return语句。更新后的MinGW工具链（GCC版本升级）启用了更严格的编译检查，针对这种未返回值的函数插入了ud2指令，导致运行时触发SIGILL错误。

解决方法 #

修改eventFilter函数，添加符合Qt要求的返回值：

• 如果需要拦截事件，返回true；
• 如果需要让事件继续传递，返回false。

示例修改后的代码：

bool PermanentInventory::eventFilter(QObject *watched, QEvent *event) {
    if(event->type() == QEvent::KeyPress && watched == _ui->perminventory_searchedit){
        if(((QKeyEvent*)event)->key() == Qt::Key_Enter ||((QKeyEvent*)event)->key() == Qt::Key_Return){
            search();
            // 根据需求选择返回true或false
            return false;
        }
    }
    // 默认返回false，允许事件继续传递
    return false;
}

内容的提问来源于stack exchange，提问作者Mathieu Monfort