------- Comment #3 from kenneth dot hoste at elis dot ugent dot be 2007-04-20
20:51 -------
identifying source code lines corresponding to infinite loop using GDB:
(gdb) backtrace
#0 regclass (f=0x9ac29f4, nregs=71) at regclass.c:732
#1 0x08065d5c in rest_of_compilation (decl=0x9b4526c) at toplev.c:3056
#2 0x0805713b in finish_function (nested=0) at c-decl.c:6791
#3 0x08048a25 in yyparse () at c-parse.c:1684
#4 0x08066a83 in compile_file (name=Variable "name" is not available.
) at toplev.c:2227
#5 0x080681a3 in main (argc=4, argv=0xbf945ea4) at toplev.c:3921
(gdb) n
736 else if ((GET_CODE (insn) == INSN
(gdb) n
717 for (insn = f; insn; insn = NEXT_INSN (insn))
(gdb) n
729 if (GET_CODE (insn) == NOTE
(gdb) n
732 else if (GET_CODE (insn) == NOTE
(gdb) n
736 else if ((GET_CODE (insn) == INSN
(gdb) n
717 for (insn = f; insn; insn = NEXT_INSN (insn))
(gdb) backtrace
#0 regclass (f=0x9ac29f4, nregs=71) at regclass.c:717
#1 0x08065d5c in rest_of_compilation (decl=0x9b4526c) at toplev.c:3056
#2 0x0805713b in finish_function (nested=0) at c-decl.c:6791
#3 0x08048a25 in yyparse () at c-parse.c:1684
#4 0x08066a83 in compile_file (name=Variable "name" is not available.
) at toplev.c:2227
#5 0x080681a3 in main (argc=4, argv=0xbf945ea4) at toplev.c:3921
(gdb)
The program seems stuck in the for-loop at line 717. The value for insn
seems to be cycling (it's taking different values, but cycles back to a
previous value).
Any pointers on how to reduce this further are welcome... Since this is
(pretty old though) GCC code (the 176.gcc corresponds to a 2.x version of GCC I
believe), maybe someone can shed soem light on this? I'm not at all familiar
with GCCs insides...
--
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=31642
