https://gcc.gnu.org/bugzilla/show_bug.cgi?id=80757
Bug ID: 80757
Summary: Internal compiler error when omitting upper subscript
of a character substring in a module subroutine
Product: gcc
Version: 6.3.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: fortran
Assignee: unassigned at gcc dot gnu.org
Reporter: GF_bug_report at freemail dot hu
Target Milestone: ---
Dear GNU Fortran Developers,
I found a bug in GNU Fortran. The following code (module + main program)
causes internal compiler error. Putting the problematic line from the
module subroutine into the main program (as char_array(2:4)(3:)= 'FO')
does not cause any compilation or runtime error.
Omitting the lower subscript like this: ch_array(2:4)(:2)= 'FO'
compiles and runs without error.
Omitting both subscripts like this: ch_array(2:4)(:)= 'FO'
compiles and runs without error.
The error exists with -std=f95, f2003 and f2008 switches as well.
I use GNU Fortran 6.3.0 under Debian 9.0.
I have an older GNU Fortran also, v4.4.5. which produces the same error.
Thank you for your efforts in advance,
Aron
THE SOURCE CODE THAT CAUSES THE BUG:
module modu
implicit none
contains
subroutine sub(ch_array)
character(len=*), intent(inout) :: ch_array(:)
! Putting here ----v `4' or `len(ch_array)', the code compiles.
ch_array(2:4)(3:)= 'FO'
endsubroutine sub
endmodule modu
program GF_compiler_error
use modu
implicit none
character(len=4) :: char_array(6)
integer :: j
char_array= 'abcd' ! vector operation
write(*,'(i1,a)') (j,'_'//char_array(j)//'_', j=1,SIZE(char_array))
write(*,*) ' '
call sub(char_array)
write(*,'(i1,a)') (j,'_'//char_array(j)//'_', j=1,SIZE(char_array))
endprogram GF_compiler_error
THE COMMAND LINE THAT TRIGGERS THE BUG:
gfortran -v -save-temps -std=f2008 -o out.bug ./character_array_bug.f90
THE COMPILER OUTPUT IS:
Driving: gfortran -v -save-temps -std=f2008 -o out.bug
./character_array_bug.f90 -l gfortran -l m -shared-libgcc
Using built-in specs.
COLLECT_GCC=gfortran
COLLECT_LTO_WRAPPER=/usr/lib/gcc/x86_64-linux-gnu/6/lto-wrapper
Target: x86_64-linux-gnu
Configured with: ../src/configure -v --with-pkgversion='Debian 6.3.0-16'
--with-bugurl=file:///usr/share/doc/gcc-6/README.Bugs
--enable-languages=c,ada,c++,java,go,d,fortran,objc,obj-c++ --prefix=/usr
--program-suffix=-6 --program-prefix=x86_64-linux-gnu- --enable-shared
--enable-linker-build-id --libexecdir=/usr/lib --without-included-gettext
--enable-threads=posix --libdir=/usr/lib --enable-nls --with-sysroot=/
--enable-clocale=gnu --enable-libstdcxx-debug --enable-libstdcxx-time=yes
--with-default-libstdcxx-abi=new --enable-gnu-unique-object
--disable-vtable-verify --enable-libmpx --enable-plugin --enable-default-pie
--with-system-zlib --disable-browser-plugin --enable-java-awt=gtk
--enable-gtk-cairo --with-java-home=/usr/lib/jvm/java-1.5.0-gcj-6-amd64/jre
--enable-java-home --with-jvm-root-dir=/usr/lib/jvm/java-1.5.0-gcj-6-amd64
--with-jvm-jar-dir=/usr/lib/jvm-exports/java-1.5.0-gcj-6-amd64
--with-arch-directory=amd64 --with-ecj-jar=/usr/share/java/eclipse-ecj.jar
--with-target-system-zlib --enable-objc-gc=auto --enable-multiarch
--with-arch-32=i686 --with-abi=m64 --with-multilib-list=m32,m64,mx32
--enable-multilib --with-tune=generic --enable-checking=release
--build=x86_64-linux-gnu --host=x86_64-linux-gnu --target=x86_64-linux-gnu
Thread model: posix
gcc version 6.3.0 20170425 (Debian 6.3.0-16)
COLLECT_GCC_OPTIONS='-v' '-save-temps' '-std=f2008' '-o' 'out.bug'
'-shared-libgcc' '-mtune=generic' '-march=x86-64'
/usr/lib/gcc/x86_64-linux-gnu/6/f951 ./character_array_bug.f90 -quiet
-dumpbase character_array_bug.f90 -mtune=generic -march=x86-64 -auxbase
character_array_bug -std=f2008 -version -fintrinsic-modules-path
/usr/lib/gcc/x86_64-linux-gnu/6/finclude -o character_array_bug.s
GNU Fortran (Debian 6.3.0-16) version 6.3.0 20170425 (x86_64-linux-gnu)
compiled by GNU C version 6.3.0 20170425, GMP version 6.1.2, MPFR
version 3.1.5, MPC version 1.0.3, isl version 0.15
GGC heuristics: --param ggc-min-expand=100 --param ggc-min-heapsize=131072
GNU Fortran2008 (Debian 6.3.0-16) version 6.3.0 20170425 (x86_64-linux-gnu)
compiled by GNU C version 6.3.0 20170425, GMP version 6.1.2, MPFR
version 3.1.5, MPC version 1.0.3, isl version 0.15
GGC heuristics: --param ggc-min-expand=100 --param ggc-min-heapsize=131072
./character_array_bug.f90:8:0:
ch_array(2:4)(3:)= 'FO'
internal compiler error: Segmentation fault
Please submit a full bug report,
with preprocessed source if appropriate.
See <file:///usr/share/doc/gcc-6/README.Bugs> for instructions.
