获取QString时出现分段错误

Question

Strange problem, already looked into with several colleagues... Using Qt Creator and Qt 4.8.5

• define an object
• set a number of values with setters
• request values with a getters
• result: getting an int no problem, all other values give segmentation fault
• but with breakpoint in debugger the values are correctly shown, so they are in the object!

• same code worked before, problem "just appeared". Compiler issue?

   private: int id; QString name; public; int getId() { return this->id; } // OK void setId(int id) { this->id = id; } QString getName() { return this->name; } // SIGSEGV void setName(QString name) { this->name = name; } 

Any ideas? Same issue known?

UPDATE

Changed code to this, based on comments, still same issue

    private:
        int id;
        QString name;

    public;
       int getId() { return id; } // OK
       void setId(int setTo) { id = setTo; } 

       QString getName() { return name; } // SIGSEGV
       void setName(QString setTo) { name = setTo; }

Answer 1

I was facing similar issue. Although I could not find the root cause of this issue, I have another observation. If we define the getter functions outside the class declaration using scope resolution operator the code works.

QString MyClass::GetX(void) {
    return mX;
}

QString MyClass::GetY(void) {
    return mY;
}

class MyClass
{
public:
    MyClass(){}

    /* Functions for setting mX and mY strings. */

    QString GetX(void);

    QString GetY(void);

    isDataAvailable()
    {
        return mAvailable;
    }

private:
    bool mAvailable;
    QString mX;
    QString mY;
};

As I understand, in C++, if we define a function within class declaration, by default it is inline... so the issue could be something related with inlining of the functions.

Answer 2

thinking further about the way objects are created in memory, I thought that a QString maybe doesn't reserve fixed number of bytes, which could be the cause of this strange behavior and guess what, a dummy change solved my problem...

This feels like a really "dirty" solution, but at least I can go on with my work ;-) But any idea's on the root cause would really be appreciated! Thanks already for all the valuable comments!!!

private:
    QString name; // FIRST DEFINE QSTRING
    int id; // THEN DEFINE INT

public;
   int getId() { return id; } // OK
   void setId(int setTo) { id = setTo; } 

   QString getName() { return name; } // OK
   void setName(QString setTo) { name = setTo; }