https://gcc.gnu.org/bugzilla/show_bug.cgi?id=97976
--- Comment #12 from Jonathan Wakely ---
(And for the linux kernel I think it's that the don't want the data flow
analysis done by that option, rather than allowing objects to live at address
zero)
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=97976
--- Comment #11 from Jonathan Wakely ---
The fact that objects cannot live at address zero is not just a GCC quirk. As I
said, it's required by the C and C++ standards. A null pointer cannot be
dereferenced, and cannot point to any object. I'm su
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=97976
--- Comment #10 from Peter Bisroev ---
Jonathan, thank you so much for your explanation. As soon as I read it, it all
started to make sense.
>You cannot increment or decrement a pointer past the end of an array (except
>the one past the end pos
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=97976
--- Comment #9 from Jonathan Wakely ---
6.3.2.3 p3 says a null pointer compares unequal to any pointer to an object, so
that means no object can ever be at address 0 in a valid C program. If you're
not using the -fno-delete-null-pointer-checks o
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=97976
--- Comment #8 from Jonathan Wakely ---
6.5.6 p8 covers it. You cannot increment or decrement a pointer past the end of
an array (except the one past the end position). C++ has similar rules. GCC
assumes there is no object at address zero, see th
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=97976
--- Comment #7 from Peter Bisroev ---
Thank you for your response Jonathan.
If you have a minute, could you please clarify a few things. I have been
talking about this behavior with a few colleagues and we are all slightly
confused by the same i
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=97976
Jonathan Wakely changed:
What|Removed |Added
Resolution|FIXED |INVALID
--- Comment #6 from Jonathan W
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=97976
Peter Bisroev changed:
What|Removed |Added
Resolution|INVALID |FIXED
--- Comment #5 from Peter Bisroev
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=97976
Richard Biener changed:
What|Removed |Added
Status|UNCONFIRMED |RESOLVED
Resolution|---
