https://gcc.gnu.org/bugzilla/show_bug.cgi?id=88737
Bug ID: 88737
Summary: RFE: Track ownership moves
Product: gcc
Version: unknown
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: c
Assignee: unassigned at gcc dot gnu.org
Reporter: neal at walfield dot org
Target Milestone: ---
I would like an attribute to indicate that ownership of an argument is moved to
the function. That is, any subsequent accesses to the variable should be
considered invalid, and gcc should emit a warning, if possible.
Consider the following example:
```
#include <stdlib.h>
#include <stdio.h>
int
main(int argc, char *argv[]) {
int *a = malloc(sizeof(int));
*a = 1;
printf("%d\n", *a);
free(a);
printf("%d\n", *a);
return 0;
}
```
Compiling this with -Wall (using gcc 6.3.0-18+deb9u1 from Debian) does not emit
a warning even though there is a use-after-free bug.
Although freeing a variable is the most obvious example of this pattern, this
pattern often arises when dealing with pointers.
This RFE is based on my experience using Rust's lifetimes, which prevent this
type of error in Rust.
