memory_leaking_valgrind.md

Memory checking with Address Sanitizer

Address Sanitizer is a tool developed by Google to check your code for various memory issues such as overflowing, memory leaking, dangling pointer .. etc.

Adding Address Sanitizer

First you need to add it by adding the right flag:

set(CMAKE_CXX_FLAGS "-fsanitize=address ${CMAKE_CXX_FLAGS}")
set(CMAKE_CXX_FLAGS "-fno-omit-frame-pointer ${CMAKE_CXX_FLAGS}")

Memory Leaking Detection

void memory_leak()
{
    unsigned char  *x=new unsigned char [5];
}

Dangling Pointer (Use After Free)

void dangling_pointer()
{
    unsigned char  *x=new unsigned char [5];
    delete[] x;
    x[0]=1;
}

Heap Buffer_overflow

void heap_buffer_overflow()
{
    unsigned char  *x=new unsigned char [5];
    for(int i=0;i<10;i++)
    {
        x[i]++;
    }
}

Stack Buffer_overflow

void stack_buffer_overflow()
{
    char x[5];
    for(int i=0;i<10;i++)
    {
        x[i]++;
    }
}

Stack Overflow

void stack_overflow()
{
    int nStack[100000000];
}

Refs: 1

Memory Leaking Detection with Valgrind

First disable the Address Sanitizer:

#set(CMAKE_CXX_FLAGS "-std=c++0x ${CMAKE_CXX_FLAGS}")
#set(CMAKE_CXX_FLAGS "-fsanitize=address ${CMAKE_CXX_FLAGS}")
#set(CMAKE_CXX_FLAGS "-fno-omit-frame-pointer ${CMAKE_CXX_FLAGS}")

Then run:

valgrind --tool=memcheck --leak-check=yes --show-reachable=yes --num-callers=20 --track-fds=yes ./memory_checking

Refs: 1