FP Memleak when resource is passed to function call through a function pointer

[Aaron Danen]

Hello

When analyzing this function with ./cppcheck test.c

void f(void (*fptr)(void *)) {
  void *buf = malloc(1);
  (*fptr)(buf);
}

I get

test.c:4:1: error: Memory leak: buf [memleak]
}
^

even though the call to whatever fptr points to might free or take ownership of buf.

However, this similar function correctly reports no errors.

void f() {
  void *buf = malloc(1);
  g(buf);
}

It is because in lib/checkleakautovar.cpp the "do we call a function" code only matches functions that are called with the standard "%name% (" syntax. I have a branch which modifies this check to handle function calls through function pointers, lambdas, and through functions that return function pointers like get_function()(buf). If it is helpful, I can make a PR once there is an issue.

Best,
Aaron

[CHR]

Thanks for reporting, ticket is here: https://trac.cppcheck.net/ticket/14990

[Aaron Danen]

Thanks, pr is here: https://github.com/cppcheck-opensource/cppcheck/pull/8813