[Bug target/108283] Problem when accessing address zero

["masmiseim at gmx dot de" <gcc-bugzilla@gcc.gnu.org>]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=108283

Markus <masmiseim at gmx dot de> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|RESOLVED                    |UNCONFIRMED
         Resolution|INVALID                     |---

--- Comment #4 from Markus <masmiseim at gmx dot de> ---
Hello Andrew, 

thanks for the feedback.
Using an mmu respectively working on application-level on an OS like Linux is
as far as I know the only exception on ARM devices where zero is not a valid
address from target point of view.
For example, compare the Technical Reference Manual of the Cortex M7
(https://developer.arm.com/documentation/ddi0489/f/programmers-model/system-address-map?lang=en)
in Chapter ‘System address map’ is defined that the complete address range from
0x0 to 0x1FFFFFFF is reserved for Code Memory.

Why not set the -fdelete-null-pointer-checks option also for ARM Targets like
it is done for AVR, MSP430? Wouldn't it be better to generate a warning
instead?

If this is not possible, why not creating a warning in addition to the
special-null-pointer handling. As a user I’m not aware of every switch and
option of the compiler. Therefore, it was not obvious that this was an
intentional behaviour of the compiler and not a bug. Especially since CLANG
worked here as I would expect it to.

Regards