cppcheck can't detect leaks when heap pointers are passed to functions?

Question

Why does cppcheck fail to detect a memory leak in a program like this example, where ownership of a heap pointer is passed to a function that fails to free it?

#include <stdlib.h>

void func(char *xx)
{
    // do nothing
}

int main(void)
{
    char *p = malloc(1000);
    func(p);
    return 0;
}

If I remove the call to func(p) then cppcheck does detect the leak.

Answer 1

I am using Cppcheck 1.69 and this correctly informed me there was a memory leak. I have the following code:

#include <stdlib.h>

void func(char *xx)
{
    // do nothing
}

int main(void)
{
    char *p = (char*)malloc(1000);
    func(p);
    return 0;
}

Note that I have converted malloc to a char* to compile, but I tried Cppcheck with the exact same code you posted and it still correctly told me there was a memory leak.

When I run:

cppcheck main.cpp

I'm presented the following:

C:\Program Files (x86)\Cppcheck>cppcheck main.cpp
Checking main.cpp...
[main.cpp:12]: (error) Memory leak: p

I checked the change log for 1.69 and interestingly it says:

Improvements:
- Improved buffer overrun and memory leak checking

Cppcheck also correctly informs me of a memory leak if I use new :

char* p = new char;
func(p);

And if I deallocate the memory in func there is no error:

void func(char *xx)
{
    delete p;
}

int main(void)
{
    char* p = new char;
    func(p);
    return 0;
}

If I allocate with malloc and try to deallocate with delete in func , Cppcheck also informs me of a mismatchAllocDealloc error.