[Valgrind-users] How to write a tool to check unsafe strcpy-alike functions in another way

[hamid a. <ham...@gm...>]

Hi everyone,
Assume there is a C code that do this:

char buff1[20];
char buff2[30]="some small string";
...
strcpy(buff1, buff2);

This code is can be regarded unsafe not only because it use strcpy(), which
doesn't accept a size argument for the maximum capacity of buff1, but also
because the maximum capacity if the target string buff1 is less than the
maximum capacity of the src string buff2.

I know that if strcpy() tries to write outside buff1, then memcheck or
sgcheck can detect that, depending on whether these strings are in
stack/global memory or in the heap. But I want a warning while calling
strcpy() in this manner as well, regardless of whether overflow happens or
not.

I am wondering if there is such a tool to do so. I guess it should replace
strcpy() and similar functions with a wrapper. Does anybody know suck a
tool/extension or how to write such a wrapper that can have access to the
max-size of buff1 and buff2?

Regards,
Hamid.