https://gcc.gnu.org/bugzilla/show_bug.cgi?id=106018
Bug ID: 106018
Summary: Feature Request: Add function attribute fn_enter, and
fn_exit
Product: gcc
Version: 13.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: c
Assignee: unassigned at gcc dot gnu.org
Reporter: alan.rosenthal at gmail dot com
Target Milestone: ---
Add a function attributes: fn_enter and fn_exit to auto generate functions that
are called before a function starts and after a function ends.
This function:
char myfn(int param1, bool pararm2, void* param3) __attribute__ ((fn_enter,
fn_exit)) {
if (param1) {
return '0';
}
if (param2) {
return '1';
}
char ret = (char) param3;
return ret;
}
Would generated these two functions:
void __enter_myfn(int param1, bool pararm2, void* param3);
void __exit_myfn(char ret);
These functions would be called during normal enter/exit conditions, i.e.:
char myfn(int param1, bool pararm2, void* param3) __attribute__ ((fn_enter,
fn_exit)) {
__enter_myfn(param1, param2, param3);
if (param1) {
__exit_fn('0');
return '0';
}
if (param2) {
__exit_fn('1');
return '1';
}
char ret = (char) param3;
__exit_fn(ret);
return ret;
}
This would allow a developer to easily add diagnostics to a specific function
to get a better sense of how often it was called, with what arguments, and what
the return value were.
Similarly functionality exists in -finstrument-functions, but it doesn't
provide a way to capture function parameters or return values.
