[Bug fortran/79863] Assignment of unallocated array to unallocated array variable leads to access of unallocated memory

[dominiq at lps dot ens.fr]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=79863

Dominique d'Humieres <dominiq at lps dot ens.fr> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |WAITING
   Last reconfirmed|                            |2017-03-22
     Ever confirmed|0                           |1

--- Comment #1 from Dominique d'Humieres <dominiq at lps dot ens.fr> ---
Confirmed from 4.3.1 up to trunk (7.0). Compiling the test with
-fsanitize=address gives at run time

ASAN:DEADLYSIGNAL
=================================================================
==66411==ERROR: AddressSanitizer: SEGV on unknown address 0x000000000000 (pc
0x00010f411c16 bp 0x7fff507ee360 sp 0x7fff507ee220 T0)
==66411==The signal is caused by a READ memory access.
==66411==Hint: address points to the zero page.
    #0 0x10f411c15 in MAIN__
(/Users/dominiq/Documents/Fortran/g95bench/win/f90/bug/a.out+0x100000c15)
    #1 0x10f411d8e in main
(/Users/dominiq/Documents/Fortran/g95bench/win/f90/bug/a.out+0x100000d8e)
    #2 0x7fffe1349254 in start (/usr/lib/system/libdyld.dylib+0x5254)

Note that I didn't find any explicit rule saying the code is invalid, I suspect
it is based on the forbidden use of unallocated variable.