[Solved] Valgrind getting strange error

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First of all and most importantly: This is not good C++ code, not even decent. For example, some of your #includes are wrong, like <stdio.h> should be <cstdio> instead. The worst thing here are those #defines that make your code utterly unreadable. You really should read a good book on C++!

For better readability I produced the pre-processor output of your code (minus the includes of course). It looks like this:

template<class A> std::string str(A a) { std::stringstream ss; ss<<a; return ss.str(); }
template<class A, class ... B> std::string str(A a, B...b) { std::stringstream ss; ss<<a<<str(b...); return ss.str(); }
template<class A, class X>
void add(std::map<std::string,int> &m, X x, A a) { if(strncmp(a,x,(new std::string(a))->length())==0)m[a] += atoi(strchr(x,':')+1);}
template<class A, class X, class ... B>
void add(std::map<std::string,int> &m, X x, A a, B...b) { if(strncmp(a,x,(new std::string(a))->length())==0)m[a] += atoi(strchr(x,':')+1); add(m, x, b...); }

const char* name() { return str("/proc/",getpid(),"/smaps").c_str(); }

int main(int __attribute__((unused)) argc, char __attribute__((unused)) *args[])
{
    char b[256];
    std::map<std::string,int> m;

    FILE *fp = fopen(name(), "r");
        while(fgets(b, 256, fp))
            add(m,b,"Rss","Shared","Private","Swap","Pss","Referenced");

        for(auto it : m) { auto a = it.first; auto b = it.second;
            int value = b;
            fprintf(stderr, "%s: %d\n", a.c_str(), b);
        }
    fclose(fp);

    return 1;
}

The line causing the error is 

FILE *fp = fopen(name(), "r");

This is invalid because you pass a pointer to the internal buffer of the local std::string object in name() to fopen. This object ceases to exist at the end of name(), and thus the pointer does not point to valid memory anymore.

Note that you also have a memory leak in your add methods: You new up std::string objects that never get deleted.

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solved Valgrind getting strange error