Valgrind 报告不匹配的 free() / delete / delete []

Question

我正在编写一个可在多个系统上运行的库（其中一些没有 malloc 或标准库）。在我的标准库（不同的库）中，我重写了 new 和 delete 运算符以对函数进行通用调用（此示例没有这些函数）。每个系统都会将这些通用调用覆盖到它们各自的内存分配设备。

问题出在我尝试执行此操作时。下面是一些精简的示例代码来重现该问题：

#include <cstdlib>

void* operator new(unsigned long size) {
        return std::malloc(size); // would normally call an intermediate function which would be overridden by the system
}

void operator delete(void* object) {
        std::free(object); // would normally call an intermediate function which would be overridden by the system
}
void operator delete(void* object, unsigned long size) {
        std::free(object); // would normally call an intermediate function which would be overridden by the system
}

class MyClass {

};

int main() {
    MyClass* myClass = new MyClass();
    delete myClass;
}

当我使用纯 gcc-6（无参数）和运行以及 valgrind（无参数）构建它时，出现此错误：

==11219== Mismatched free() / delete / delete []
==11219==    at 0x4C2DD6B: free (in /usr/lib/valgrind/vgpreload_memcheck-amd64-linux.so)
==11219==    by 0x108730: operator delete(void*, unsigned long) (in /home/chris13524/tmp/test.o)
==11219==    by 0x10875A: main (in /home/chris13524/tmp/test.o)
==11219==  Address 0x5200040 is 0 bytes inside a block of size 1 alloc'd
==11219==    at 0x4C2D1AF: operator new(unsigned long) (in /usr/lib/valgrind/vgpreload_memcheck-amd64-linux.so)
==11219==    by 0x108745: main (in /home/chris13524/tmp/test.o)

看来 delete 运算符工作正常，但 Valgrind 正在覆盖我覆盖的 new 运算符。知道如何解决这个问题吗？

删除中间函数不是一个选项，因为我还有其他代码。

它在我的真实程序中如何工作的示例（同样，我的示例中未显示）：

new => create => <intermediate code> => createImpl => malloc
create => <intermediate code> => createImpl => malloc

我正在使用 gcc v6.2.0、valgrind v3.12.0 和 Ubuntu 16.10。

Answer 1

感谢 Paul Floyd，此错误已在提交 6ef6f738a. See bug report here 中修复。

但是，此修复程序尚未发布（截至 2018 年 6 月），可能需要更长时间才能出现在发行版中。如果您现在需要此修复，我建议从 source.

开始构建

Valgrind 报告不匹配的 free() / delete / delete []

Valgrind reporting Mismatched free() / delete / delete []

c++

gcc

valgrind

new-operator

gcc6