[Bug fortran/110076] New: ICE on mutually recursive derived types.

["srm.1708 at gmail dot com" <gcc-bugzilla@gcc.gnu.org>]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=110076

            Bug ID: 110076
           Summary: ICE on mutually recursive derived types.
           Product: gcc
           Version: 12.2.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: fortran
          Assignee: unassigned at gcc dot gnu.org
          Reporter: srm.1708 at gmail dot com
  Target Milestone: ---

Minimal repro is:

$ cat main.f90
module foo
    type bar
        type(baz), allocatable :: a
    end type

    type baz
        type(bar), allocatable :: b
    end type
end module
$ gfortran -c main.f90
gfortran: internal compiler error: Segmentation fault: 11 signal terminated
program f951
Please submit a full bug report, with preprocessed source (by using
-freport-bug).
See <https://gcc.gnu.org/bugs/> for instructions.

Removing the allocatable statements or making it singly recursive (i.e.
removing the baz type and giving bar a field of type(bar)) avoids the ICE.

This is potentially a duplicate of 94599 or 104048, but neither of those is
exhibited _only_ when the types are mutually recursive so I thought I should
open this up any way.

I've tested this with two different versions of GFortran:

$ gfortran -v
Using built-in specs.
COLLECT_GCC=/nix/store/gg2pvn8xifrwbaa09msl6k9g921j1595-gfortran-12.2.0/bin/gfortran
COLLECT_LTO_WRAPPER=/nix/store/gg2pvn8xifrwbaa09msl6k9g921j1595-gfortran-12.2.0/libexec/gcc/aarch64-apple-darwin/12.2.0/lto-wrapper
Target: aarch64-apple-darwin
Configured with:
Thread model: posix
Supported LTO compression algorithms: zlib
gcc version 12.2.0 (GCC)

$ gfortran -v
Using built-in specs.
COLLECT_GCC=gfortran
COLLECT_LTO_WRAPPER=/usr/lib/gcc/x86_64-linux-gnu/10/lto-wrapper
OFFLOAD_TARGET_NAMES=nvptx-none:amdgcn-amdhsa:hsa
OFFLOAD_TARGET_DEFAULT=1
Target: x86_64-linux-gnu
Configured with: ../src/configure -v --with-pkgversion='Debian 10.2.1-6'
--with-bugurl=file:///usr/share/doc/gcc-10/README.Bugs
--enable-languages=c,ada,c++,go,brig,d,fortran,objc,obj-c++,m2 --prefix=/usr
--with-gcc-major-version-only --program-suffix=-10
--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-bootstrap --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 --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-10-Km9U7s/gcc-10-10.2.1/debian/tmp-nvptx/usr,amdgcn-amdhsa=/build/gcc-10-Km9U7s/gcc-10-10.2.1/debian/tmp-gcn/usr,hsa
--without-cuda-driver --enable-checking=release --build=x86_64-linux-gnu
--host=x86_64-linux-gnu --target=x86_64-linux-gnu
--with-build-config=bootstrap-lto-lean --enable-link-mutex
Thread model: posix
Supported LTO compression algorithms: zlib zstd
gcc version 10.2.1 20210110 (Debian 10.2.1-6)