[Bug fortran/96041] [11 regression] ICE in gfortran.dg/pr93423.f90 after r11-1792

[seurer at linux dot vnet.ibm.com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=96041

--- Comment #5 from Bill Seurer <seurer at linux dot vnet.ibm.com> ---
It hits that breakpoints many times and for the first many it was always 0. 
Then I just let it run until it ICEd and backed up the call stack a bit.


Program received signal SIGSEGV, Segmentation fault.
0x00000000106dcbd4 in free_st_labels (label=0x981) at
/home/seurer/gcc/git/gcc-test/gcc/fortran/symbol.c:2662
2662      free_st_labels (label->left);
(gdb) where
#0  0x00000000106dcbd4 in free_st_labels (label=0x981) at
/home/seurer/gcc/git/gcc-test/gcc/fortran/symbol.c:2662
#1  0x00000000106dcbe0 in free_st_labels (label=0x13492760) at
/home/seurer/gcc/git/gcc-test/gcc/fortran/symbol.c:2662
#2  0x00000000106dcbe0 in free_st_labels (label=0x3fffb7e50a58 <main_arena+88>)
at /home/seurer/gcc/git/gcc-test/gcc/fortran/symbol.c:2662
#3  0x00000000106dff28 in gfc_free_namespace (ns=0x13495ae0) at
/home/seurer/gcc/git/gcc-test/gcc/fortran/symbol.c:4050
#4  0x00000000106dda60 in gfc_free_symbol (sym=0x13493e40) at
/home/seurer/gcc/git/gcc-test/gcc/fortran/symbol.c:3084
#5  0x00000000106ddc14 in gfc_release_symbol (sym=0x13493e40) at
/home/seurer/gcc/git/gcc-test/gcc/fortran/symbol.c:3125
#6  0x00000000106dfa10 in free_sym_tree (sym_tree=0x13493e00) at
/home/seurer/gcc/git/gcc-test/gcc/fortran/symbol.c:3902
#7  0x00000000106dfa00 in free_sym_tree (sym_tree=0x13493ac0) at
/home/seurer/gcc/git/gcc-test/gcc/fortran/symbol.c:3900
#8  0x00000000106df9f0 in free_sym_tree (sym_tree=0x13493fa0) at
/home/seurer/gcc/git/gcc-test/gcc/fortran/symbol.c:3899
#9  0x00000000106dfe90 in gfc_free_namespace (ns=0x1348f6b0) at
/home/seurer/gcc/git/gcc-test/gcc/fortran/symbol.c:4041
#10 0x00000000106e0144 in gfc_symbol_done_2 () at
/home/seurer/gcc/git/gcc-test/gcc/fortran/symbol.c:4101
#11 0x000000001062536c in gfc_done_2 () at
/home/seurer/gcc/git/gcc-test/gcc/fortran/misc.c:358
#12 0x000000001066cec8 in clean_up_modules (gsym=0x13490330) at
/home/seurer/gcc/git/gcc-test/gcc/fortran/parse.c:6267
#13 0x000000001066d22c in translate_all_program_units
(gfc_global_ns_list=0x13477bf0) at
/home/seurer/gcc/git/gcc-test/gcc/fortran/parse.c:6330
#14 0x000000001066da84 in gfc_parse_file () at
/home/seurer/gcc/git/gcc-test/gcc/fortran/parse.c:6546
#15 0x00000000106f0488 in gfc_be_parse_file () at
/home/seurer/gcc/git/gcc-test/gcc/fortran/f95-lang.c:212
#16 0x0000000011248514 in compile_file () at
/home/seurer/gcc/git/gcc-test/gcc/toplev.c:458
#17 0x000000001124d87c in do_compile () at
/home/seurer/gcc/git/gcc-test/gcc/toplev.c:2307
#18 0x000000001124dda4 in toplev::main (this=0x3fffffffe910, argc=20,
argv=0x3fffffffed78) at /home/seurer/gcc/git/gcc-test/gcc/toplev.c:2446
#19 0x00000000124facf4 in main (argc=20, argv=0x3fffffffed78) at
/home/seurer/gcc/git/gcc-test/gcc/main.c:39

up a few times...

4050      free_st_labels (ns->st_labels);
(gdb) print ns->st_labels
$8 = (gfc_st_label *) 0x3fffb7e50a58 <main_arena+88>