https://gcc.gnu.org/bugzilla/show_bug.cgi?id=96122
Bug ID: 96122
Summary: Segfault when using finalizer
Product: gcc
Version: 11.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: fortran
Assignee: unassigned at gcc dot gnu.org
Reporter: abensonca at gcc dot gnu.org
Target Milestone: ---
The following code segfaults with gfortran 11.0.0:
module a
type vs
character(len=1), dimension(:), allocatable :: ch
contains
final :: vsf
end type vs
type mtd
type(vs), dimension(2) :: n
end type mtd
contains
subroutine c()
type(mtd) :: m
allocate(m%n(1)%ch(1))
m%n(1)%ch(1)="a"
allocate(m%n(2)%ch(1))
m%n(2)%ch(1)="b"
return
end subroutine c
subroutine vsf(s)
type(vs), intent(inout) :: s
if (allocated(s%ch)) deallocate(s%ch)
return
end subroutine vsf
end module a
program b
use a
call c()
end program b
$ gfortran -v
Using built-in specs.
COLLECT_GCC=gfortran
COLLECT_LTO_WRAPPER=/home/abenson/Galacticus/Tools/libexec/gcc/x86_64-pc-linux-gnu/11.0.0/lto-wrapper
Target: x86_64-pc-linux-gnu
Configured with: ../gcc-git/configure --prefix=/home/abenson/Galacticus/Tools
--enable-languages=c,c++,fortran --disable-multilib
Thread model: posix
Supported LTO compression algorithms: zlib
gcc version 11.0.0 20200705 (experimental) (GCC)
$ gfortran tmp.F90 -g
$ ./a.out
Program received signal SIGSEGV: Segmentation fault - invalid memory reference.
Backtrace for this error:
#0 0x7f47668d61ef in ???
at
/data001/abenson/Galacticus/Tools/glibc-2.12.1/signal/../sysdeps/unix/sysv/linux/x86_64/sigaction.c:0
#1 0x40118f in __a_MOD___final_a_Vs
at /home/abenson/Galacticus/Nightlies/galacticus/tmp.F90:30
#2 0x400bfa in __a_MOD___final_a_Mtd
at /home/abenson/Galacticus/Nightlies/galacticus/tmp.F90:30
#3 0x401556 in __a_MOD_c
at /home/abenson/Galacticus/Nightlies/galacticus/tmp.F90:22
#4 0x401562 in b
at /home/abenson/Galacticus/Nightlies/galacticus/tmp.F90:34
#5 0x401599 in main
at /home/abenson/Galacticus/Nightlies/galacticus/tmp.F90:33
Segmentation fault
The problem doesn't occur if the finalizer for type "vs" isn't used. It also
doesn't occur if the "n" component of type "mtd" has dimension(1) or is a
scalar.
The finalizer in this case is pointless (since it just deallocates an
allocatable, which would happen automatically if no finalizer were used), but
as far as I can see is legal code.
This appears to be a regression (worked in 10.1) but I haven't yet tracked down
exactly where the problem was introduced.
