CODEWITHSUNDEEP
dllgetcwd
Stefanos Anastasiou
Stefanos Anastasiou

Reputation: 11

Placing function in .dll causes debug assertion failed error

Hallo fellow members,

I run into a very strange problem today and I am not exactly sure as to what is causing it. Here is a function which I use to get the current working directory : 

#ifdef _WIN32
#include <direct.h>
#define GetCurrentDir _getcwd
#else
#error "There is currently no support for non windows based systems!"
#endif

const std::string getCurrentPath()
{
   char CurrentPath{_MAX_PATH];
   GetCurrentDir(CurrentPath, _MAX_PATH);
   CurrentPath[_MAX_PATH - 1] = '/0';
   return std::string(CurrentPath);
}

This function works well as a stand alone function. However if I declare it as a static function inside a class :

static __declspec(dllexport) const std::string getCurrentPath(void);

and a .dll I get "debug assertion failed error" when I try to do 

std::cout<<CUtilities::getCurrentPath()<<std::endl;

If I instead write :

std::string dir = CUtilities::getCurrentPath();
std::cout<<"Dir is : "<<dir<<std::endl;

it works fine. I am totally confused as to what I am doing wrong. Any ideas?

Upvotes: 0

Views: 459

Answers (1)

Stefanos Anastasiou
Stefanos Anastasiou

Reputation: 11

I finally found out what the problem was. The project was compiled with /MT options , therefore the .dll had a different heap than the original file. So when the string size was bigger than it's initial size (15) then heap was allocated from the .dll's side. However the string had it's destructor called from the main program side and then the destructor was trying to deallocate memory from the .dll's heap thus resulting in "heap corruption error"

The solution was to simply compile with /MD options.

Upvotes: 1

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