[Bug fortran/106918] New: Cannot use structure constructor with component allocatable character array of deferred length

[guez at lmd dot ens.fr]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=106918

            Bug ID: 106918
           Summary: Cannot use structure constructor with component
                    allocatable character array of deferred length
           Product: gcc
           Version: 12.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: fortran
          Assignee: unassigned at gcc dot gnu.org
          Reporter: guez at lmd dot ens.fr
  Target Milestone: ---

gcc version 12.0.1 20220319 (experimental) [master r12-7719-g8ca61ad148f]
(Ubuntu 12-20220319-1ubuntu1)

Configured with: ../src/configure -v --with-pkgversion='Ubuntu
12-20220319-1ubuntu1' --with-bugurl=file:///usr/share/doc/gcc-12/README.Bugs
--enable-languages=c,ada,c++,go,d,fortran,objc,obj-c++,m2 --prefix=/usr
--with-gcc-major-version-only --program-suffix=-12
--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 --enable-clocale=gnu --enable-libstdcxx-debug
--enable-libstdcxx-time=yes --with-default-libstdcxx-abi=new
--enable-gnu-unique-object --disable-vtable-verify --enable-plugin
--enable-default-pie --with-system-zlib --enable-libphobos-checking=release
--with-target-system-zlib=auto --enable-objc-gc=auto --enable-multiarch
--disable-werror --enable-cet --with-arch-32=i686 --with-abi=m64
--with-multilib-list=m32,m64,mx32 --enable-multilib --with-tune=generic
--enable-offload-targets=nvptx-none=/build/gcc-12-OcsLtf/gcc-12-12-20220319/debian/tmp-nvptx/usr,amdgcn-amdhsa=/build/gcc-12-OcsLtf/gcc-12-12-20220319/debian/tmp-gcn/usr
--enable-offload-defaulted --without-cuda-driver --enable-checking=release
--build=x86_64-linux-gnu --host=x86_64-linux-gnu --target=x86_64-linux-gnu

GNU Fortran (Ubuntu 11.2.0-19ubuntu1) 11.2.0

Here is a test program:

$ cat test_coord_def.f90
  character(len = :), allocatable:: attr_name(:)
  type coord_def
     character(len = :), allocatable:: attr_name(:)
  end type coord_def
  type(coord_def) coordinates
  attr_name = ["units"]
  print *, 'attr_name: "', attr_name, '"'
  coordinates = coord_def(attr_name)
  print *, 'coordinates%attr_name: "', coordinates%attr_name, '"'
end

The compilation command is:

$ gfortran-12 test_coord_def.f90

There is no compilation message.

The execution fails:

$ ./a.out
 attr_name: "units"
Operating system error: Cannot allocate memory
Memory allocation failure in xrealloc

Error termination. Backtrace:
#0  0x1538fa556ae0 in ???
#1  0x1538fa557659 in ???
#2  0x1538fa557834 in ???
#3  0x1538fa555fee in ???
#4  0x1538fa7ba355 in ???
#5  0x1538fa7ab1b9 in ???
#6  0x1538fa7b3c00 in ???
#7  0x1538fa7b90ae in ???
#8  0x1538fa7ba105 in ???
#9  0x1538fa7ab8a8 in ???
#10  0x555fac4a76d8 in ???
#11  0x555fac4a7751 in ???
#12  0x1538fa334d8f in __libc_start_call_main
        at ../sysdeps/nptl/libc_start_call_main.h:58
#13  0x1538fa334e3f in __libc_start_main_impl
        at ../csu/libc-start.c:392
#14  0x555fac4a7114 in ???
#15  0xffffffffffffffff in ???

I think the source code is valid. Note that if I replace the structure
constructor by an equivalent assignment to the component, the problem
disappears:

$ cat test_coord_def.f90
  character(len = :), allocatable:: attr_name(:)
  type coord_def
     character(len = :), allocatable:: attr_name(:)
  end type coord_def
  type(coord_def) coordinates
  attr_name = ["units"]
  print *, 'attr_name: "', attr_name, '"'
  coordinates%attr_name = attr_name
  !!coordinates = coord_def(attr_name)
  print *, 'coordinates%attr_name: "', coordinates%attr_name, '"'
end

$ gfortran-12 test_coord_def.f90

$ ./a.out
 attr_name: "units"
 coordinates%attr_name: "units"

Also, for additional information, there is no problem with ifort 19.1.