const * char in struct in class - segmentation fault

Question

I have this code and it gives me segmentation fault.

struct TRecord {
    const char * Id;
    const char * Name;
};
class CClass {
    CClass ();
    ~CClass ();
    bool Add ( const char * id, const char * name);
    TRecord ** m_record;
    int m_count;
};

CClass::CClass (void) {
    m_count = 0;
    m_record = new TRecord * [1000];
}

CClass::~CClass(void) {
    for(int i=0;i<m_count;i++){
        delete m_record[i];
    }
    delete [] m_record;
}

bool CClass::Add (const char * id, const char * name) {
    m_record[m_count] -> Id = new char[11];
    m_record[m_count] -> Name = new char[strlen(name) + 1];

    m_record[m_count] -> Id = id;
    m_record[m_count] -> Name = name;

    m_count++;
    return true;
}

If I add for example const char haha[2222]; to struct TRecord, it works. I don't understand why. Can you help me?

P.S. I can't use string.

Which method do you call on which object to produce a segmentation fault? — Oswald, Apr 09 '13 at 20:37
This line isn't valid C++: `m_record = new TRecord * [1000];` — Brian Neal, Apr 09 '13 at 20:42
@BrianNeal It's valid, It will allocate memory for thousands of `TRecord *`s to m_record. — MostafaR, Apr 09 '13 at 20:44
@MostafaR oops, you are correct. The spaces around the * threw me for some reason. — Brian Neal, Apr 09 '13 at 20:45

score 1 · Answer 1 · edited May 23 '17 at 12:21

1

One error is that you are not following the rule of three in your CRegister class. That often causes segfaults.

Another error is that you do not initialise your m_record[i] pointers. So you destructor may call delete[] on garbage values.

A third error is that you apparently dereference the same garbage values in CRegister::Add.

edited May 23 '17 at 12:21

Community

1
1

answered Apr 09 '13 at 20:37

john

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MostafaR · Accepted Answer · 2013-04-09T20:48:54.873

1

Add this line as to top of you Add function declaration, It will fix your Segmentation Fault problem.

m_record[m_count] = new TRecord;

But as you can see in answers and comments, your code has many problems. Most important problem is that you have not any good plan for your garbage objects. So your code have memory leakage.

edited Apr 09 '13 at 20:48

answered Apr 09 '13 at 20:40

MostafaR

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Ah, I forgot about this :/ Thanks! – user2171413 Apr 09 '13 at 20:42
@mostafaR what about the fact that he leaks memory every time he calls `Add`? – Dan F Apr 09 '13 at 20:44
@DanF I should fix my sentence, I think with this line the Segmentation Fault Error will be fixed, but It has problems yet. – MostafaR Apr 09 '13 at 20:45
@DanF Thanks, I tried to edit my answer and mention other problems of code in it. – MostafaR Apr 09 '13 at 20:49
How can I fix the problem with garbage objects? A destructor in struct? – user2171413 Apr 09 '13 at 21:58

const * char in struct in class - segmentation fault

2 Answers2