Question

我的程序正确终止，根据Valgrind的说法，没有泄露的内存。

但是第一次运行对象方法时会出现以下消息。

Use of uninitialised value of size 8

获取有关上述事件的更多详细信息

==18787== Use of uninitialised value of size 8
==18787==    at 0x4017F3: Grid::init(int) (grid.cc:90)
==18787==    by 0x401D2A: main (main.cc:43)
==18787==  Uninitialised value was created by a stack allocation
==18787==    at 0x401BE4: main (main.cc:11)

我还看到以下消息：

Conditional jump or move depends on uninitialised value(s)
Invalid free() / delete / delete[] / realloc()
Address 0x7ff000b08 is on thread 1's stack

这是Grid :: init

的代码

void Grid::init(int n){
    if (!(&(this->theGrid))) { this->clearGrid(); } //If non-empty, destroys grid

    this->theGrid = new Cell*[n]; //Create new grid of size n x n
    this->td = new TextDisplay(n); //new Text Display 
    for (int i = 0; i < n; i++){
        this->theGrid[i] = new Cell[n];
        for(int j = 0; j < n; j++){ //Cell initializations
            (this->theGrid[i][j]).setDisplay(this->td); //set display
            (this->theGrid[i][j]).setCoords(i, j); //set co-ordinates
            (this->theGrid[i][j]).setState(0); //default state
        }
    }
}

Answer 1

我猜你的代码看起来像是：

条件跳转或移动取决于未初始化的值：

bool value /* nothing */;
if (value) {
}

免费无效：

char* buf = new char[10000];
buf = &x;
delete [] buf;

现在您发布了代码，我假设第90行是这一行：

if (!(&(this->theGrid))) { this->clearGrid(); } //If non-empty, destroys grid

问题是您没有在构造函数中初始化theGrid到nullptr，然后您最终可能delete[] - 非new[] - ed数组。此外，如果您刚刚执行了以下操作，那么代码会更清晰：

if (!theGrid) {
    clearGrid();
}

到处都不需要this->。我不明白为什么你要使用theGrid的地址。

这些valgrind / GNU调试器错误消息是什么意思？

1 个答案: