[Bug tree-optimization/94527] New: RFE: Add an __attribute__ that marks a function as freeing an object

["dhowells at redhat dot com" <gcc-bugzilla@gcc.gnu.org>]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=94527

            Bug ID: 94527
           Summary: RFE: Add an __attribute__ that marks a function as
                    freeing an object
           Product: gcc
           Version: unknown
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: tree-optimization
          Assignee: unassigned at gcc dot gnu.org
          Reporter: dhowells at redhat dot com
  Target Milestone: ---

Would it be possible to add a function attribute to indicate that the function
is going to destroy the object a the parameter points to (ie. a free()-like
function)?  Perhaps something like:

    void free(const volatile void *ptr) __attribute__((free(1)));

where the free(N) attribute indicates the parameter number[*].

[*] Note that it's possible that a free()-like function might also take
additional parameters to provide context and that context won't be destroyed.

The compiler could then warn upon future access through the pointer.