Is there any static checking tool to check buggy code like this

Question

I wrote the some buggy code like this:

#include "stdafx.h"
#include <string>
using namespace std;

int _tmain(int argc, _TCHAR* argv[])
{

    string some_file = "afdfadf";

    if(true)
    {
        string some_file = "/"+ some_file;
    }

    return 0;
}

It will throw an exception when calling std::operator+.

I guess this is because in the if statement the second some_file is an uninitialized string.

Is there any static checking tool that can help find this kind of bug?

Answer 1

GCC has a warning for that case:

$ g++ t.cc -Wshadow
t.cc: In function ‘int main(int, char**)’:
t.cc:11:16: warning: declaration of ‘some_file’ shadows a previous local [-Wshadow]
t.cc:7:12: warning: shadowed declaration is here [-Wshadow]

Answer 2

I just tried, clang can help find the bug:

[~]$ clang bug.cpp 
bug.cpp:11:29: warning: variable 'some_file' is uninitialized when used within
      its own initialization [-Wuninitialized]
    string some_file = "/"+ some_file;
           ~~~~~~~~~        ^~~~~~~~~

Answer 3

Compilers can warn you about using a variable in its own initialization.

In GCC and CLANG, you can use -Winit-self I am not sure about MSVC, but compiling with /W4 might give you a warning about those, too.

Answer 4

I was quit happy with using pclint. It will find this type of errors but it might take some time to configure it when used with an existing, larger code base.