删除指针会导致堆损坏

Deleting pointer causes heap corruption

本文关键字:损坏 指针 删除      更新时间:2023-10-16

谁能解释一下为什么这段代码会导致堆损坏?

string someText = "hello hello";
char **arrayOfCharPtr = new char*[5];
arrayOfCharPtr[0] = new char[someText.length()];
strcpy(arrayOfCharPtr[0], someText.c_str());
delete[] arrayOfCharPtr[0];

非常感谢!

您需要分配比字符串长度多一个字符来存储最后一个''字符。

arrayOfCharPtr[0] = new char[someText.length()+1];

在你的例子中,strcpy会在分配的块之后写最后一个'',这会破坏堆。

像valgrind这样的工具可以帮助理解。Valgrind产生错误消息
==16970== Invalid write of size 1
==16970==    at 0x4C3106F: strcpy (in /usr/lib/valgrind/vgpreload_memcheck-amd64-linux.so)
==16970==    by 0x400C47: main
==16970==  Address 0x5ab5cfb is 0 bytes after a block of size 11 alloc'd
==16970==    at 0x4C2E80F: operator new[](unsigned long) (in /usr/lib/valgrind/vgpreload_memcheck-amd64-linux.so)
==16970==    by 0x400C1C: main