When a function returns void, it can be used as an argument to return in
function returning also void, e.g.:
void in(void) {
return;
}
void out(void) {
return (in());
}
while this is legal, it should be rewritten as:
void out(void) {
in();
return;
}
The semantic patch just find the occurrences, and they need to be fixed
by hand.
Some semantic patches are meant to be run just once, as they work on
functions with changed prototypes. We keep them for reference, but
disabled them from the CI to save time.
The dns_name_copy() function cannot fail gracefully when the last argument
(target) is NULL. Add RUNTIME_CHECK()s around such calls.
The first semantic patch adds RUNTIME_CHECK() around any call that ignores the
return value and is very safe to apply.
The second semantic patch attempts to properly add RUNTIME_CHECK() to places
where the return value from `dns_name_copy()` is recorded into `result`
variable. The result of this semantic patch needs to be reviewed by hand.
Both patches misses couple places where the code surrounding the
`dns_name_copy(..., NULL)` usage is more complicated and is better suited to be
fixed by a human being that understands the surrounding code.
The isc_mem_get() cannot fail gracefully now, it either gets memory of
assert()s. The added semantic patch cleans all the blocks checking whether
the return value of isc_mem_get() was NULL.