SanitizerCoverage feature

Hi,

I was wondering what amount of effort would patching SanitizerCoverage
take to provide separate execution traces for active and passive call
stacks for crashing input?

E.g.

main.c

1. void foo() {
2. printf("foo\n");
3. }
4.
5. int main() {
6. foo();
7. abort();
8. return 1;
9. }

Crash backtrace

#0 main.c:7 abort()

Active call stack contains only PCs covered in call sites that haven't

returned
Active trace: main.c:5, main.c:6, main.c:7

Passive call stack contains PCs covered in call sites that have returned

Passive trace: main.c:1, main.c:2, main.c:3

Regards,
Bhargava