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)