根据这个问题,
下面是两个示例代码以说明这种行为。 没有堆: 以下代码:
std::array
是在堆栈上分配的。然而,当与Valgrind
一起使用时,它向我显示了一个堆分配,即使对于在堆栈上分配的元素也是如此。这是一个误报还是真实情况?下面是两个示例代码以说明这种行为。 没有堆: 以下代码:
#include <array>
int main() {
std::array<int*, 1> map;
int value = 0;
}
该代码将产生以下预期的Valgrind
输出:
==14425== HEAP SUMMARY:
==14425== in use at exit: 0 bytes in 0 blocks
==14425== total heap usage: 0 allocs, 0 frees, 0 bytes allocated
使用堆:
但是,如果我尝试运行以下代码:
#include <array>
int main() {
std::array<int*, 1> map;
int value = 0;
map.at(0) = &value;
}
< p > Valgrind
给我提供了
==14539== HEAP SUMMARY:
==14539== in use at exit: 72,704 bytes in 1 blocks
==14539== total heap usage: 1 allocs, 0 frees, 72,704 bytes allocated
==14539==
==14539== 72,704 bytes in 1 blocks are still reachable in loss record 1 of 1
==14539== at 0x4C2DB8F: malloc (in /usr/lib/valgrind/vgpreload_memcheck-amd64-linux.so)
==14539== by 0x4EC3EFF: ??? (in /usr/lib/x86_64-linux-gnu/libstdc++.so.6.0.21)
==14539== by 0x40106B9: call_init.part.0 (dl-init.c:72)
==14539== by 0x40107CA: call_init (dl-init.c:30)
==14539== by 0x40107CA: _dl_init (dl-init.c:120)
==14539== by 0x4000C69: ??? (in /lib/x86_64-linux-gnu/ld-2.23.so)
==14539==
新增编译设置:
g++ -std=c++11 -O0 valgrind.cpp -o valgrind_build -I ../fake -I ../src
valgrind --track-origins=yes --dsymutil=yes --leak-check=full --show-leak-kinds=all ./valgrind_build
valgrind --version
valgrind-3.11.0
g++ --version
g++ (Ubuntu 5.4.0-6ubuntu1~16.04.11) 5.4.0 20160609
Copyright (C) 2015 Free Software Foundation, Inc.
This is free software; see the source for copying conditions. There is NO
warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
cin
和cout
)的样子。 - NathanOliver