[Bug sanitizer/112708] "gcc -fsanitize=address" produces wrong debug info for variables in function prologue

["bruno at clisp dot org" <gcc-bugzilla@gcc.gnu.org>]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=112708

--- Comment #5 from Bruno Haible <bruno at clisp dot org> ---
(In reply to Andrew Pinski from comment #3)
> Also did you add -fvar-tracking-assignments ?

No, I haven't. I have specified CFLAGS=-ggdb, indicating that
  - I don't care about the optimization level,
  - but I want the ability to debug with gdb. And that includes not being
disturbed and alarmed by wrong values of variables. (I wouldn't mind if
single-stepping would not stop at the function entry directly, only at the
first statement of the function. Then I would not have the opportunity to do
'print context' at the wrong moment.)

Which passes and internal machinery GCC needs in order to fulfil these goals,
should be GCC internal. In other words, I specify '-ggdb' and expect GCC to do
the rest.

Additionally, Jakub Jelinek writes in
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=102523#c2 :
! sometimes -O0 -g is debuggable much better than -Og -g, sometimes the other
way around.
Which is not really a recommendation to use this option on a general basis.