[Bug middle-end/10138] warn for uninitialized arrays passed as const* arguments

["bangerth at dealii dot org" <gcc-bugzilla at gcc dot gnu dot org>]

------- Comment #14 from bangerth at dealii dot org  2007-08-20 15:54 -------
(In reply to comment #12)

> This testcase has nothing to do with uninitialized variables.

No, of course. I only meant to reply to your assertion that there could be
cases where a function initializes an object that is passed as a const
pointer. That may work in C, but not in C++. I agree that my example may
have been confusing, so take this slight variant of it ('a' is here non-const
and uninitialized):
-------------------
char a[3];
int main () {
  return atoi (a);
}
-------------------
It is my understanding that C++ allows 'a' to be put into read-only memory
because the only access is read-only. What that means is that functions like
atoi that take constant arguments have no legitimate way to initialize the
objects they get, and every uninitialized object passed to them is necessarily
a source of bugs.

This is meant to only counter your point that:
> 'const' does not mean read-only in C++ at all, and much less in C. atoi(const
> char *) could always initialize buf[].
This simply isn't true. In C++, atoi can't do that.

W.


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http://gcc.gnu.org/bugzilla/show_bug.cgi?id=10138