J.P. Malhado originally reported this bug in Debian BTS as http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=518642.
debian_chroot:sid:kusumanchi:/home/518642# cat string.f90 write(6,*) 'string1' write(6,'(A)') 'string2' end debian_chroot:sid:kusumanchi:/home/518642# /usr/lib/gcc-snapshot/bin/gfortran -g -malign-double string.f90 debian_chroot:sid:kusumanchi:/home/518642# ./a.out string1 Segmentation fault (core dumped) The segmentation fault does not occur if the -malign-double option is not used. It is reproducible in gfortran 4.3.2, 4.3.5, 4.4.4, 4.5.1 and 4.6.0. debian_chroot:sid:kusumanchi:/home/518642# /usr/lib/gcc-snapshot/bin/gfortran -v Using built-in specs. COLLECT_GCC=/usr/lib/gcc-snapshot/bin/gfortran COLLECT_LTO_WRAPPER=/usr/lib/gcc-snapshot/libexec/gcc/i486-linux-gnu/4.6.0/lto-wrapper Target: i486-linux-gnu Configured with: ../src/configure -v --with-pkgversion='Debian 20100828-1' --with-bugurl=file:///usr/share/doc/gcc-snapshot/README.Bugs --enable-languages=c,ada,c++,fortran,objc,obj-c++ --prefix=/usr/lib/gcc-snapshot --enable-shared --enable-multiarch --enable-linker-build-id --with-system-zlib --disable-nls --enable-clocale=gnu --enable-libstdcxx-debug --enable-libstdcxx-time=yes --enable-plugin --enable-gold --with-plugin-ld=ld.gold --enable-objc-gc --enable-targets=all --with-arch-32=i586 --with-tune=generic --disable-werror --enable-checking=yes --build=i486-linux-gnu --host=i486-linux-gnu --target=i486-linux-gnu Thread model: posix gcc version 4.6.0 20100828 (experimental) [trunk revision 163616] (Debian 20100828-1) debian_chroot:sid:kusumanchi:/home/518642# gdb -q ./a.out Reading symbols from /home/518642/a.out...done. (gdb) r Starting program: /home/518642/a.out string1 Program received signal SIGSEGV, Segmentation fault. format_hash (dtp=0xbffffb50) at ../../../src/libgfortran/io/format.c:152 152 ../../../src/libgfortran/io/format.c: No such file or directory. in ../../../src/libgfortran/io/format.c (gdb)bt #0 format_hash (dtp=0xbffffb50) at ../../../src/libgfortran/io/format.c:152 #1 find_parsed_format (dtp=0xbffffb50) at ../../../src/libgfortran/io/format.c:189 #2 parse_format (dtp=0xbffffb50) at ../../../src/libgfortran/io/format.c:1228 #3 0x400c3610 in data_transfer_init (dtp=0xbffffb50, read_flag=0) at ../../../src/libgfortran/io/transfer.c:2227 #4 0x08048619 in MAIN__ () at string.f90:2 thanks raju -- Summary: segmentation fault occurs when printing string if - malign-double option is used Product: gcc Version: 4.6.0 Status: UNCONFIRMED Severity: normal Priority: P3 Component: fortran AssignedTo: unassigned at gcc dot gnu dot org ReportedBy: kamaraju at gmail dot com http://gcc.gnu.org/bugzilla/show_bug.cgi?id=45724