https://gcc.gnu.org/bugzilla/show_bug.cgi?id=99043
Bug ID: 99043 Summary: Inconsistent behavior when calling rank(ptr) for assumed-rank null pointer Product: gcc Version: 10.2.0 Status: UNCONFIRMED Severity: normal Priority: P3 Component: fortran Assignee: unassigned at gcc dot gnu.org Reporter: gustav.r.jansen at gmail dot com Target Milestone: --- Created attachment 50156 --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=50156&action=edit Source code that reproduces the described behaviour Calling rank(ptr) on an assumed-rank null pointer dummy argument returns -1 when the procedure is called with an assumed-rank argument, while it returns the correct rank when the procedure is called with a non-assumed-rank argument. The attached file contains a small reproducer to illustrate the behavior. Here is the output when executed: Lvl1: Expected rank 3, got rank: 3 Lvl2: Expected rank 3, got rank: -1 Here is the output of the compiler: /home/software/gcc/10.2.0/bin/gfortran -v -save-temps -Wall -Wextra -fno-strict-aliasing -fwrapv -fno-aggressive-loop-optimizations -fsanitize=undefined -o assumed_rank.x main.f90 Driving: /home/software/gcc/10.2.0/bin/gfortran -v -save-temps -Wall -Wextra -fno-strict-aliasing -fwrapv -fno-aggressive-loop-optimizations -fsanitize=undefined -o assumed_rank.x main.f90 -l gfortran -l m -shared-libgcc Using built-in specs. COLLECT_GCC=/home/software/gcc/10.2.0/bin/gfortran COLLECT_LTO_WRAPPER=/home/software/gcc/10.2.0/libexec/gcc/x86_64-pc-linux-gnu/10.2.0/lto-wrapper Target: x86_64-pc-linux-gnu Configured with: ../gcc-10.2.0/configure --prefix=/home/software/gcc/10.2.0 --disable-multilib Thread model: posix Supported LTO compression algorithms: zlib gcc version 10.2.0 (GCC) COLLECT_GCC_OPTIONS='-v' '-save-temps' '-Wall' '-Wextra' '-fno-strict-aliasing' '-fwrapv' '-fno-aggressive-loop-optimizations' '-fsanitize=undefined' '-o' 'assumed_rank.x' '-shared-libgcc' '-mtune=generic' '-march=x86-64' /home/software/gcc/10.2.0/libexec/gcc/x86_64-pc-linux-gnu/10.2.0/f951 main.f90 -quiet -dumpbase main.f90 -mtune=generic -march=x86-64 -auxbase main -Wall -Wextra -version -fno-strict-aliasing -fwrapv -fno-aggressive-loop-optimizations -fsanitize=undefined -fintrinsic-modules-path /home/software/gcc/10.2.0/lib/gcc/x86_64-pc-linux-gnu/10.2.0/finclude -o main.s GNU Fortran (GCC) version 10.2.0 (x86_64-pc-linux-gnu) compiled by GNU C version 10.2.0, GMP version 6.1.0, MPFR version 3.1.4, MPC version 1.0.3, isl version isl-0.18-GMP GGC heuristics: --param ggc-min-expand=100 --param ggc-min-heapsize=131072 GNU Fortran2008 (GCC) version 10.2.0 (x86_64-pc-linux-gnu) compiled by GNU C version 10.2.0, GMP version 6.1.0, MPFR version 3.1.4, MPC version 1.0.3, isl version isl-0.18-GMP GGC heuristics: --param ggc-min-expand=100 --param ggc-min-heapsize=131072 COLLECT_GCC_OPTIONS='-v' '-save-temps' '-Wall' '-Wextra' '-fno-strict-aliasing' '-fwrapv' '-fno-aggressive-loop-optimizations' '-fsanitize=undefined' '-o' 'assumed_rank.x' '-shared-libgcc' '-mtune=generic' '-march=x86-64' as -v --64 -o main.o main.s GNU assembler version 2.30 (x86_64-linux-gnu) using BFD version (GNU Binutils for Ubuntu) 2.30 Reading specs from /home/software/gcc/10.2.0/lib64/../lib64/libgfortran.spec rename spec lib to liborig COLLECT_GCC_OPTIONS='-v' '-save-temps' '-Wall' '-Wextra' '-fno-strict-aliasing' '-fwrapv' '-fno-aggressive-loop-optimizations' '-fsanitize=undefined' '-o' 'assumed_rank.x' '-shared-libgcc' '-mtune=generic' '-march=x86-64' COMPILER_PATH=/home/software/gcc/10.2.0/libexec/gcc/x86_64-pc-linux-gnu/10.2.0/:/home/software/gcc/10.2.0/libexec/gcc/x86_64-pc-linux-gnu/10.2.0/:/home/software/gcc/10.2.0/libexec/gcc/x86_64-pc-linux-gnu/:/home/software/gcc/10.2.0/lib/gcc/x86_64-pc-linux-gnu/10.2.0/:/home/software/gcc/10.2.0/lib/gcc/x86_64-pc-linux-gnu/ LIBRARY_PATH=/home/software/gcc/10.2.0/lib64/../lib64/:/home/software/gcc/10.2.0/lib/gcc/x86_64-pc-linux-gnu/10.2.0/:/home/software/gcc/10.2.0/lib/gcc/x86_64-pc-linux-gnu/10.2.0/../../../../lib64/:/lib/x86_64-linux-gnu/:/lib/../lib64/:/usr/lib/x86_64-linux-gnu/:/home/software/gcc/10.2.0/lib64/:/home/software/gcc/10.2.0/lib/gcc/x86_64-pc-linux-gnu/10.2.0/../../../:/lib/:/usr/lib/ COLLECT_GCC_OPTIONS='-v' '-save-temps' '-Wall' '-Wextra' '-fno-strict-aliasing' '-fwrapv' '-fno-aggressive-loop-optimizations' '-fsanitize=undefined' '-o' 'assumed_rank.x' '-shared-libgcc' '-mtune=generic' '-march=x86-64' /home/software/gcc/10.2.0/libexec/gcc/x86_64-pc-linux-gnu/10.2.0/collect2 -plugin /home/software/gcc/10.2.0/libexec/gcc/x86_64-pc-linux-gnu/10.2.0/liblto_plugin.so -plugin-opt=/home/software/gcc/10.2.0/libexec/gcc/x86_64-pc-linux-gnu/10.2.0/lto-wrapper -plugin-opt=-fresolution=main.res -plugin-opt=-pass-through=-lgcc_s -plugin-opt=-pass-through=-lgcc -plugin-opt=-pass-through=-lquadmath -plugin-opt=-pass-through=-lm -plugin-opt=-pass-through=-lgcc_s -plugin-opt=-pass-through=-lgcc -plugin-opt=-pass-through=-lc -plugin-opt=-pass-through=-lgcc_s -plugin-opt=-pass-through=-lgcc --eh-frame-hdr -m elf_x86_64 -dynamic-linker /lib64/ld-linux-x86-64.so.2 -o assumed_rank.x /usr/lib/x86_64-linux-gnu/crt1.o /usr/lib/x86_64-linux-gnu/crti.o /home/software/gcc/10.2.0/lib/gcc/x86_64-pc-linux-gnu/10.2.0/crtbegin.o -L/home/software/gcc/10.2.0/lib64/../lib64 -L/home/software/gcc/10.2.0/lib/gcc/x86_64-pc-linux-gnu/10.2.0 -L/home/software/gcc/10.2.0/lib/gcc/x86_64-pc-linux-gnu/10.2.0/../../../../lib64 -L/lib/x86_64-linux-gnu -L/lib/../lib64 -L/usr/lib/x86_64-linux-gnu -L/home/software/gcc/10.2.0/lib64 -L/home/software/gcc/10.2.0/lib/gcc/x86_64-pc-linux-gnu/10.2.0/../../.. main.o -lgfortran -lm -lubsan -lgcc_s -lgcc -lquadmath -lm -lgcc_s -lgcc -lc -lgcc_s -lgcc /home/software/gcc/10.2.0/lib/gcc/x86_64-pc-linux-gnu/10.2.0/crtend.o /usr/lib/x86_64-linux-gnu/crtn.o COLLECT_GCC_OPTIONS='-v' '-save-temps' '-Wall' '-Wextra' '-fno-strict-aliasing' '-fwrapv' '-fno-aggressive-loop-optimizations' '-fsanitize=undefined' '-o' 'assumed_rank.x' '-shared-libgcc' '-mtune=generic' '-march=x86-64'